WO2021085024A1 - Projection lens and projection device - Google Patents

Abstract

A projection lens equipped with a reflection part which reflects light incident from an electro-optical element, an emission optical system which emits the light reflected by the reflection part, a first cylinder part which has the reflection part, a second cylinder part which has the emission optical system, and a rotation mechanism which rotates both the first and second cylinder parts, wherein the rotation mechanism rotates the first cylinder part at a smaller angle than the second cylinder part.

Description

Projection lens and projection device

The technology of the present disclosure relates to a projection lens and a projection device.

The projection optical device described in JP-A-2019-002969 includes a first optical system that forms an intermediate image, a second optical system that enlarges the intermediate image, and a first optical system arranged on an optical path in the first optical system. The first mirror, the second mirror arranged between the first optical system and the second optical system, the first holding member for holding the first optical system and the first mirror, the second optical system and the second mirror. A second holding member for holding the

In Japanese Patent Application Laid-Open No. 2019-002969, the first optical system houses a first lens group arranged on the incident side of the first mirror and a first lens group, and is held by a first holding member. It includes a cylinder, a second lens group arranged on the exit side of the first mirror, and a second lens cylinder that houses the second lens group and is at least partially arranged in the first holding member. .. Further, the second optical system includes a third lens group arranged along the optical axis of the second optical system, a third lens barrel that houses the third lens group and is held by the second holding member. It has. A first holding member and a second holding member are connected to the second optical system.

The projector described in Japanese Patent No. 6378448 has a first optical axis bending member arranged between the first optical system and an imaging surface formed by the first optical system and the first optical system to bend the optical axis, and a first optical axis bending member. A second optical system that projects an image formed by the optical system onto a projection surface, a second optical axis bending member that is arranged on the second optical system and bends the optical axis, and a first optical system and a first optical axis bending. The first holding member that integrally holds the members, the second holding member that integrally holds the second optical system and the second optical axis bending member, and the first one that intersects the optical axis on the exit side of the first optical system. The first joint surface formed on the holding member, the second joint surface formed on the second holding member intersecting the optical axis on the incident side of the second optical system, and the first joint surface and the second joint surface. In the combined state, at least one of the first holding member and the second holding member is configured to be rotatable in the in-plane direction of the first joint surface and the second joint surface with respect to the other, and is rotatable around the optical axis. It is provided with a projection lens including a joint portion that forms a U-shaped optical path by aligning the optical axes of the emitting side and the incident side of the second optical system.

One embodiment according to the technique of the present disclosure provides a projection lens and a projection device capable of tilting the emission optical system even when the reflection portion that bends the optical axis is provided.

A first aspect according to the technique of the present disclosure is a reflecting portion that reflects light incident from an electro-optical element, an exit optical system that emits light reflected by the reflecting portion, and a first tubular portion having a reflecting portion. A second cylinder portion having an emission optical system and a rotation mechanism for rotating both the first cylinder portion and the second cylinder portion are provided, and the rotation mechanism rotates the first cylinder portion at a smaller angle than the second cylinder portion. It is a rotating projection lens.

The second aspect according to the technique of the present disclosure is the projection lens according to the first aspect in which the rotation mechanism rotates the first cylinder portion in conjunction with the second cylinder portion.

The third aspect according to the technique of the present disclosure is the first aspect or the second aspect in which the rotation mechanism rotates the first cylinder portion at an angle of 1/2 with respect to the angle at which the second cylinder portion is rotated. This is the projection lens.

The fourth aspect according to the technique of the present disclosure is from the first aspect to the third aspect in which the rotation mechanism has a first gear provided in the second cylinder portion and a second gear provided in the first cylinder portion. A projection lens according to any one of the above embodiments.

The fifth aspect according to the technique of the present disclosure is the projection lens according to the fourth aspect in which the rotation axes of the first cylinder portion and the second cylinder portion are common.

In the sixth aspect according to the technique of the present disclosure, the reflective portion has a first reflective portion and a second reflective portion provided on the enlarged side of the first reflective portion, and the first tubular portion is It is a projection lens according to any one of the first to fifth aspects having two reflecting portions.

In the seventh aspect according to the technique of the present disclosure, twice the distance from the second reflecting portion to the emitting lens is the distance from the entrance of the projection lens to the first reflecting portion and from the first reflecting portion to the second reflecting portion. The projection lens according to the sixth aspect, which is shorter than the sum of the distances.

An eighth aspect according to the technique of the present disclosure is a projection according to any one of the first to seventh aspects, wherein the portion where the second tubular portion and the other member are connected is covered with a light-shielding member. It is a lens.

The ninth aspect according to the technique of the present disclosure is the projection lens according to the eighth aspect in which the light-shielding member has flexibility.

A tenth aspect according to the technique of the present disclosure includes a first cylinder portion and a second cylinder portion in addition to another cylinder portion, and the first cylinder portion and the second cylinder portion are formed of a metal material. At least a part of the other tubular portion is a projection lens according to any one of the first to ninth aspects, which is formed of a resin material.

The eleventh aspect according to the technique of the present disclosure further includes an adjustment mechanism for adjusting the optical axis by relatively moving the optical system on the enlargement side of the reflection unit and the optical system on the reduction side of the reflection unit. It is a projection lens according to any one of the first aspect to the tenth aspect.

A twelfth aspect according to the technique of the present disclosure is a cover portion that covers the second cylinder portion, the cover portion having a fixed posture regardless of the rotation of the second cylinder portion, and the second cylinder portion and the cover portion. The projection lens according to any one of the first to eleventh aspects, which is a member that covers the gap and further includes a flexible member.

The thirteenth aspect according to the technique of the present disclosure is a projection device provided with a projection lens according to any one of the first to twelfth aspects.

It is a figure which shows an example of how the image is projected on the windshield from the projection lens incorporated in the dashboard of an automobile. It is a figure which shows an example of the projection apparatus which consists of a projection lens and an image formation unit. It is a figure which shows an example of the projection apparatus which consists of a projection lens and an image formation unit. It is a side sectional view of an example of a projection lens. It is a partial side sectional view of an example of a projection lens. It is a partial side sectional view of an example of a projection lens. It is a conceptual diagram for demonstrating the rotation example of a projection lens. It is a conceptual diagram for demonstrating the rotation example of a projection lens. It is a partial front view of an example of a rotation mechanism. It is an exploded perspective view of an example of a rotation mechanism. It is a side view which shows an example of the state of rotation by a rotation mechanism. It is a partial front view of an example of a rotation mechanism. It is an exploded perspective view of an example of a rotation mechanism. It is a perspective view of an example of a rotation mechanism. It is a perspective view which shows an example of the state of rotation by a rotation mechanism. It is a conceptual diagram which shows an example of the state of adjustment by a position adjustment mechanism. It is a top view of an example of a position adjustment mechanism. It is a conceptual diagram which shows an example of the state of adjustment by a position adjustment mechanism. It is a figure which shows an example of how the gap is covered by a flexible member. It is a figure which shows an example of how the gap is covered by a flexible member. It is a figure which shows an example of how the gap is covered by a flexible member.

Hereinafter, an example of the embodiment of the technique of the present disclosure will be described with reference to the drawings. The terms such as "first", "second", and "third" used in the present specification are added to avoid confusion of the components, and are present in the projection lens or the projection device. It does not limit the number of components to be used.

In the description of the present specification, "parallel" means parallelism in the sense of including an error generally allowed in the technical field to which the technology of the present disclosure belongs, in addition to perfect parallelism. As used herein, the term "identical" refers to the exact same, as well as the same in the sense that it includes errors that are generally tolerated in the technical field to which the technology of the present disclosure belongs.

[First Embodiment]
As an example, as shown in FIGS. 1 and 2, the projection lens 10 is incorporated in the projection device 11. The projection device 11 according to the technique of the present disclosure is for transportation equipment as an example, and is provided on the dashboard 13 of the automobile 12 which is an example of the transportation equipment. A part of the projection lens 10 in the projection device 11 is exposed from the upper part of the dashboard 13. The projection device 11 projects the image P onto the windshield 14 of the automobile 12 as an example through the projection lens 10.

As an example, the projection device 11 projects the image P on the windshield 14 while the automobile 12 is stopped. Further, when the automatic driving of the automobile 12 becomes possible in the future, the projection device 11 may project the image P on the windshield 14 during the automatic driving. The automatic driving is a driving in which the accelerator, the brake, the direction indicator, the steering wheel 15, and the like, which are necessary for driving the automobile, are autonomously performed by the control device (not shown) provided in the automobile 12. Point.

As shown in FIG. 2, the projection lens 10 is roughly classified into an emission side portion 10A and an incident side portion 10B as an example. In this example, the projection lens 10 is provided on the dashboard 13 in a posture in which the emitting side portion 10A is located at the upper portion and the incident side portion 10B is located at the lower portion. The upper side of the projection lens 10, which is the emission side portion 10A, is exposed from the dashboard 13. Further, the lower side of the projection lens 10 which is the incident side portion 10B is housed in the dashboard 13. The emission side portion 10A of the projection lens 10 is covered with a cover 16. The cover 16 is made of the same material as the dashboard 13, for example. The cover 16 rotates with the rotation of the second optical system L3, which will be described later. The cover 16 is an example of a “cover portion” according to the technique of the present disclosure. An emission lens LE is arranged at the emission end of the optical path of the emission side portion 10A of the projection lens 10. The exit lens LE emits the image P toward the windshield 14.

In the incident side portion 10B of the projection lens 10, the image forming unit 20 is connected to the incident side end portion where light is incident. The image forming unit 20 and the projection lens 10 constitute a projection device 11. In the following, the side of the image forming unit 20 which is the incident side where the light is incident may be referred to as the “reduction side”, and the side of the exit lens LE which is the emission side where the light is emitted may be referred to as the “enlargement side”.

As an example, as shown in FIG. 2, since the projection lens 10 projects the image P from the dashboard 13 to the windshield 14, the projection distance is about several tens of cm. Further, the projection lens 10 projects the image P over a wide range in the length direction and the width direction of the windshield 14. Therefore, the projection lens 10 is required to have an optical performance of ultra-short focus and ultra-wide angle as compared with a projection lens used in a general projection device for indoor use.

Also, the center of the image P projected by the projection lens 10 and the optical axis of the exit lens LE do not match. More specifically, the projection lens 10 projects the image P by a so-called launch method in which the center of the projected image P is located above the optical axis of the exit lens LE by the lens shift function. Further, the projection lens 10 can perform so-called zero-offset projection in which the image P is projected on the windshield 14 so that the lower side of the image P is located at a point on the extension line of the optical axis of the exit lens LE.

The image forming unit 20 forms an image to be projected onto the windshield 14 through the projection lens 10. The image forming unit 20 includes an image forming panel 21, a light source 22, a light guide member (not shown), and the like. The light source 22 irradiates the image forming panel 21 with light. The light guide member guides the light from the light source 22 to the image forming panel 21.

As an example, the image forming unit 20 is a reflection type using a DMD (Digital Micromirror Device: registered trademark) as the image forming panel 21. The DMD has a plurality of micromirrors capable of changing the reflection direction of the light emitted from the light source 22, and is an image display element in which each micromirror is arranged in two dimensions on a pixel-by-pixel basis. The DMD performs light modulation according to the image by switching the on / off of the reflected light of the light from the light source 22 by changing the direction of each micromirror according to the image. The DMD is an example of an "electro-optical element" according to the technique of the present disclosure.

An example of the light source 22 is a white light source that emits white light. The white light source is realized by combining a laser light source and a phosphor as an example. Specifically, the laser light source emits blue light as excitation light for the phosphor. The phosphor excited by the blue light emitted from the laser light source emits yellow light. The white light source emits white light by combining blue light emitted from a laser light source and yellow light emitted from a phosphor. The image forming unit 20 is further provided with a rotating color filter that selectively converts the white light emitted by the light source 22 into blue light, green light, and red light in a time-divided manner. By selectively irradiating the image forming panel 21 with the blue, green, and red color lights, the image light carrying the image information of the blue, green, and red colors can be obtained. The image light of each color thus obtained is selectively incident on the projection lens 10 and is projected toward the windshield 14. The image lights of each color are integrated on the windshield 14. As a result, the chromatic or achromatic image P is displayed on the windshield 14.

A light beam representing an image formed by the image forming unit 20 is incident on the projection lens 10 from the image forming unit 20. The projection lens 10 magnifies and forms an image light based on the incident luminous flux. As a result, the projection lens 10 projects the image P, which is an enlarged image of the image formed by the image forming unit 20, onto the windshield 14.

By the way, the angle of the windshield 14 provided on the automobile 12 with respect to the dashboard 13 may change depending on the vehicle type and model. As an example, as shown in FIG. 3, it is assumed that the angle formed by the windshield 14 with respect to the dashboard 13 changes by the angle α1 as compared with the example of FIG. If the posture of the projection lens 10 does not change and only the angle of the windshield 14 changes, the projected image P will be distorted. Therefore, in order to accurately project the image P onto the windshield 14, it is necessary to change the attitude of the projection lens 10 with respect to the windshield 14 according to the change in the angle of the windshield 14. Specifically, as shown in FIG. 3 as an example, the projection lens needs to be rotated so that the optical axis A3 faces upward by an angle α1 as compared with before rotation. Here, rotating the third optical system L3 of the projection lens 10 in the vertical direction in FIGS. 2 and 3 is referred to as tilt. The projection lens 10 has a tilt function of the optical axis A3 so that the angle of the optical axis A3 with respect to the windshield 14 can be adjusted.

As an example, as shown in FIG. 4, the projection lens 10 includes a bending optical system. The bending optical system has a first optical axis A1, a second optical axis A2, and a third optical axis A3. The first optical axis A1 is an optical axis through which light from the image forming unit 20 passes. The second optical axis A2 is an optical axis bent by 90 ° with respect to the first optical axis A1. The third optical axis A3 is, for example, an optical axis bent by 90 ° with respect to the second optical axis A2. Therefore, the first optical axis A1 and the third optical axis A3 are parallel. Note that 90 ° here is a value including an error allowed in the design.

In the following description, the direction parallel to the first optical axis A1 and the third optical axis A3 is the Y direction, the direction parallel to the second optical axis A2 is the Z direction, and the Y direction and the direction orthogonal to the Z direction are the X directions. Express.

The projection lens 10 has a first lens barrel portion 30, a second lens barrel portion 31, and a third lens barrel portion 32. The first lens barrel portion 30 is located on the most incident side, and the third lens barrel portion 32 is located on the most exit side. The second lens barrel portion 31 is located between the first lens barrel portion 30 and the third lens barrel portion 32. Each lens barrel portion 30 to 32 holds a lens. The lens held in the first lens barrel portion 30 is arranged on the first optical axis A1. Further, the lens held in the second lens barrel portion 31 is arranged on the second optical axis A2. Further, the lens held in the third lens barrel portion 32 is arranged on the third optical axis A3.

The central axis of the first lens barrel portion 30 substantially coincides with the first optical axis A1. Further, the central axis of the second lens barrel portion 31 substantially coincides with the second optical axis A2. Further, the central axis of the third lens barrel portion 32 substantially coincides with the third optical axis A3. In FIG. 4, for simplification of the description, a plurality of lenses may be omitted and expressed as one lens.

The first lens barrel portion 30 holds the first optical system L1. As an example, the first optical system L1 is composed of a lens L11, a lens L12, a lens L13, a lens L14, a correction lens LC, and a lens L15, and is arranged along the first optical axis A1. The first optical system L1 forms an intermediate image MI of the optical image of the image forming panel 21. Further, a fixed aperture 33 is provided between the lens L13 and the lens L14. The fixed aperture 33 narrows the light flux incident from the image forming unit 20. At least a part of the first lens barrel portion 30 is formed of a resin material as an example.

The lens L11, the lens L12, and the lens L13 are held by the holding frame 34. The lens L11 and the lens L12 form a zoom lens group as an example. The lens L14 is held by the holding frame 35. The correction lens LC is held in the correction lens holding frame 36. The lens L15 is held by the holding frame 37.

The holding frame 37 is in non-contact with the correction lens LC and holds the correction lens holding frame 36.

The correction lens holding frame 36 is made of resin as an example. On the other hand, the other holding frame 34, the holding frame 35, and the holding frame 37 are formed of a metal such as aluminum as an example.

The correction lens LC is a lens mainly responsible for correcting aberrations such as curvature of field aberration. The correction lens LC is an aspherical lens that is advantageous for aberration correction, and is made of resin as an example.

On the other hand, the lenses constituting the first optical system L1 other than the correction lens LC are all made of glass in this embodiment. Since the dashboard 13 on which the projection lens 10 is arranged receives direct sunlight through the windshield 14, the projection lens 10 may be exposed to a high temperature environment of about 120 ° C. Since the projection lens 10 is used in a high temperature environment as described above, it is preferable to form the lens with glass rather than resin in consideration of heat resistance.

The second lens barrel portion 31 holds the second optical system L2. As an example, the second optical system L2 is composed of a lens L20 and is arranged along the second optical axis A2. The lens L20 is made of glass. In the present embodiment, the second optical system L2 functions as a relay lens. Specifically, the second optical system L2 relays the luminous flux representing the intermediate image MI to the third lens barrel unit 32 with the intermediate image MI imaged by the first optical system L1 as a subject.

Further, the first mirror 38 is arranged on the incident side of the second optical system L2, and the second mirror 39 is arranged on the exit side of the second optical system L2. Each of the first mirror 38 and the second mirror 39 is one of the optical elements constituting the bending optical system, and bends the optical axis. The first mirror 38 reflects the light of the first optical axis A1 to obtain the light of the second optical axis A2. The second mirror 39 reflects the light of the second optical axis A2 to obtain the light of the third optical axis A3.

A first mirror accommodating portion 46 accommodating the first mirror 38 is provided between the first lens barrel portion 30 and the second lens barrel portion 31. Further, a second mirror accommodating portion 47 accommodating the second mirror 39 is provided between the second lens barrel portion 31 and the third lens barrel portion 32.

In the first mirror accommodating portion 46, the first mirror 38 is held in a posture in which the reflecting surface forms an angle of 45 ° with respect to each of the first optical axis A1 and the second optical axis A2. Similarly, in the second mirror accommodating portion 47, the second mirror 39 is held in a posture in which the reflecting surface forms an angle of 45 ° with respect to each of the second optical axis A2 and the third optical axis A3 as an example. The first mirror 38 and the second mirror 39 are specular reflection type mirrors in which a transparent member such as glass is coated with a reflective film. The first mirror 38 and the second mirror 39 may be mirrors using a prism that totally reflects light. The first mirror 38 and / or the second mirror 39 is an example of a "reflecting unit" according to the technique of the present disclosure. Further, the first mirror 38 is an example of the "first reflecting portion" according to the technique of the present disclosure. The second mirror 39 is an example of the “second reflecting portion” according to the technique of the present disclosure.

The second lens barrel portion 31 is formed of a metal such as aluminum as an example, like the holding frame 34, the holding frame 35, and the holding frame 37 of the first lens barrel portion 30.

The third lens barrel portion 32 holds the third optical system L3. The third optical system L3 is an exit optical system that emits the light reflected by the second mirror 39 to the outside of the projection lens 10. The third lens barrel portion 32 is composed of a lens L31, a lens L32, a lens L33, a lens L34, and an exit lens LE, and is arranged along the third optical axis A3. The third optical system L3 is an example of the "exit optical system" according to the technique of the present disclosure.

The lens L31 and the lens L32 are held by the holding frame 40. The lens L31 and the lens L32 form a focus lens group as an example. The lens L33 and the lens L34 are held by the holding frame 41. The exit lens LE is held by the exit lens holding frame 42.

The holding frame 41 is in non-contact with the emitting lens LE and holds the emitting lens holding frame 42.

The exit lens holding frame 42 is made of resin as an example, like the correction lens holding frame 36. On the other hand, the other holding frame 40 and the holding frame 41 are formed of a metal such as aluminum as an example.

The exit lens LE has a shape in which a part of the outer edge portion below the third optical axis A3 is cut in a straight line. That is, the exit lens LE is a lens having a D-shaped contour in a plan view. The exit lens LE is an aspherical lens like the correction lens LC. The exit lens LE is made of, for example, a resin. Further, the lens L33 and the lens L34 located on the incident side of the exit lens LE are spherical lenses having a spherical lens surface. The lens L33 and the lens L34 are made of glass.

As described above, the projection lens 10 is required to have an ultra-short focus and an ultra-wide-angle optical performance. Therefore, the lens L33 and the lens L34 have a negative refractive power in order to magnify the projected image P, and diverge the luminous flux.

The half angle of view of the projection lens 10 is 63 ° or more, more preferably 65 ° or more. In order to secure such a wide half-angle of view, the lens L33 and the lens L34 have a high refractive power. In order to secure a high refractive power, the lens L33 and the lens L34 are glass lenses as an example, and a lens having a relatively small diameter is used in order to suppress an increase in weight.

On the other hand, the exit lens LE mainly has a function of correcting aberrations in the third optical system L3. The exit lens LE is an aspherical lens that is more advantageous for aberration correction than a spherical lens. From the viewpoint of correcting aberrations and obtaining a wide half-angle of view as described above, the exit lens LE has a recess near the third optical axis A3 on the reduction side surface and near the lens end of the reduction side surface. A lens having a convex portion is preferable.

Further, as shown in FIG. 4, as an example, the sum of the distance LA1 from the entrance of the projection lens 10 to the first mirror 38 and the distance LA2 from the first mirror 38 to the second mirror 39 is projected from the second mirror 39. The distance to the exit of the lens 10 is set to be longer than twice the distance LA3. In other words, the distance LA3 from the second reflecting portion showing the second mirror 39 as an example to the emitting lens showing the emitting lens LE as an example is twice the distance LA3, and the first mirror 38 is shown as an example from the entrance of the projection lens 10. It is set to be shorter than the sum of the distance LA1 to the first reflecting portion and the distance LA2 from the first reflecting portion to the second reflecting portion. Specifically, the following relational expression (1) holds for the distances LA1 to LA3. The entrance of the projection lens 10 is, in this example, the surface of the lens L11 on the incident side. Further, the outlet of the projection lens 10 is, in this example, the surface on the exit side of the exit lens LE.
2 x LA3 <LA1 + LA2 ... (1)

As an example, as shown in FIG. 5A, the third lens barrel portion 32 including the second mirror accommodating portion 47 is rotatable with respect to the second lens barrel portion 31 with the rotation axis RO as the rotation center. Further, the upper portion of the second lens barrel portion 31 is connected to the second mirror accommodating portion 47. Therefore, as shown in FIG. 5B as an example, the third lens barrel portion 32 rotates about the rotation axis RO. The rotation axis RO coincides with the intersection of the optical axes A2 and A3 in the second mirror 39. The third lens barrel portion 32 is an example of the “second cylinder portion” according to the technique of the present disclosure.

A mirror holding portion 50 is arranged in the second mirror accommodating portion 47 of the third lens barrel portion 32. As an example, in FIG. 5A, the mirror holding portion 50 covers the upper side, the back surface (the side opposite to the exit side in the Y-axis direction), and the sides (both sides in the width direction along the X direction) of the second mirror 39. That is, the mirror holding portion 50 is a frame-shaped member in which the light incident side (second optical axis A2 side) and the light emitting side (third optical axis A3 side) with respect to the second mirror 39 are opened. .. The second mirror 39 is fixed to the mirror holding portion 50 by, for example, adhering the outer edge to the inner peripheral surface of the mirror holding portion 50. Since the second mirror 39 is held by the mirror holding portion 50, the second mirror 39 rotates together with the mirror holding portion 50. The mirror holding portion 50 rotates about the rotation axis RO in the same manner as the second mirror accommodating portion 47 of the third lens barrel portion 32. The mirror holding portion 50 rotates with the rotation of the third lens barrel portion 32. However, as will be described later, the rotation angle of the third lens barrel portion 32 and the rotation angle of the mirror holding portion 50 do not match, and the rotation angle of the third lens barrel portion 32 is larger than the rotation angle of the mirror holding portion 50. .. Specifically, the rotation angle of the third lens barrel portion 32 is twice the rotation angle of the mirror holding portion 50. Conversely, the rotation angle of the mirror holding portion 50 is 1/2 of the rotation angle of the third lens barrel portion 32. As an example, the mirror holding portion 50 is made of a metal material such as aluminum. The mirror holding portion 50 is an example of the “first cylinder portion” according to the technique of the present disclosure.

When the third lens barrel portion 32 rotates, a gap naturally occurs between the second mirror accommodating portion 47 and the second lens barrel portion 31 of the third lens barrel portion 32. Therefore, a light-shielding member 48 that covers the gap is provided between the second mirror accommodating portion 47 and the second lens barrel portion 31. The light-shielding member 48 prevents light from leaking from the projection lens 10 and external light from entering the projection lens 10. The size of the gap between the second mirror accommodating portion 47 and the second lens barrel portion 31 changes according to the rotation angle of the second mirror accommodating portion 47. Therefore, the light-shielding member 48 is made of a flexible material. As the light-shielding member 48, as an example, an elastic material such as elastic rubber is used to form a bellows shape. Of course, the light-shielding member 48 may have flexibility, and cloth, leather, or the like may be used instead of rubber. Further, the shape of the light-shielding member 48 is not limited to the bellows shape, and may be any shape that can cover the gap whose size changes.

The fixing member 51 extends from the upper end of the second lens barrel portion 31 into the second mirror accommodating portion 47. That is, the fixing member 51 is, for example, a pair of plate-shaped members whose one end is fixed to the upper end of the second lens barrel portion 31. The pair of fixing members 51 are arranged on both sides of the mirror holding portion 50 in the X direction. As a result, the mirror holding portion 50 is arranged between the pair of fixing members 51. The mirror holding portion 50 is rotatably attached to the fixing member 51.

Further, the third lens barrel portion 32 is also rotatably attached to the fixing member 51. As a result, the third lens barrel portion 32 can be rotated in the vertical direction in FIGS. 5A and 5B with respect to the second lens barrel portion 31. That is, the projection lens 10 has a tilt function of the third optical system L3, which is an emission optical system. Thereby, in the projection lens 10, the angle formed by the optical axis A3 of the third optical system L3 and the optical axis A2 of the second optical system L2 can be changed. As a result, even if the angle of the windshield 14 with respect to the dashboard 13 is changed as an example, it can be dealt with by adjusting the angle of the third optical system L3 by the tilt function. As a result, the projection lens 10 can be applied to the projection surface of various types of transportation equipment.

The rotation mechanism 49 is a mechanism for realizing the tilt function of the third optical system L3, and rotates both the third lens barrel portion 32 and the mirror holding portion 50 with respect to the second lens barrel portion 31. This is an example of the mechanism. As will be described in detail later, the rotation mechanism 49 rotates the third lens barrel portion 32 and is larger than the rotation angle of the third lens barrel portion 32 in the second mirror accommodating portion 47 of the third lens barrel portion 32. , The mirror holding portion 50 is rotated at a small angle. Specifically, when the third optical axis A3 is rotated with respect to the second optical axis A2 by rotating the third lens barrel portion 32, the second mirror is rotated with respect to the rotation angle of the third optical axis A3. The rotation angle of 39 is set to 1/2. That is, the rotation angle of the mirror holding portion 50 is 1/2 of the rotation angle of the third lens barrel portion 32.

The reason why the rotation angle of the mirror holding portion 50 is 1/2 of the rotation angle of the third lens barrel portion 32 is that the projection lens 10 bends the second optical axis A2 to the third optical axis A3 by the second mirror 39. This is a geometrical optics reason due to having a bending optical system. That is, as shown in FIG. 6A, assuming that the state in which the third optical axis A3 is bent by 90 ° with respect to the second optical axis A2 is the initial state, in the initial state, the second mirror 39 reflects as described above. The surface is arranged in a state of being tilted by 45 ° with respect to each of the second optical axis A2 and the third optical axis A3. In the initial state, the incident angle β1 of the incident light incident on the reflecting surface of the second mirror 39 through the second optical axis A2 is 45 °, and the incident light is reflected by the reflecting surface of the second mirror 39. It emits light along the third optical axis A3. According to the law of reflection, the reflection angle is β1 as well as the incident angle β1, that is, 45 °. The incident angle β1 and the reflection angle β1 are angles with respect to the normal line H0 of the reflection surface of the second mirror 39, respectively.

Next, when the third optical axis A3 of the third optical system L3 is tilted upward around the rotation axis RO from the initial state shown in FIG. 6A to the state shown in FIG. 6B (for example, it rotates clockwise in FIG. 6B). If you let me think about it). As shown in FIG. 6B, the rotation angle of the third optical axis A3 from the initial state is α1, and the rotation angle of the reflection surface of the second mirror 39 is α2. As shown in FIG. 6B, if the normal line of the reflection surface of the second mirror 39 is H1 when the rotation angle of the second mirror 39 is α2, the reflection surface rotates α2, so naturally the normal line H1 also , Rotates clockwise by α2 with respect to the normal line H0 of the reflecting surface of the second mirror 39 in the initial state. Since the second optical axis A2 does not rotate, the incident angle β2 of the light passing through the second optical axis A2 with respect to the reflecting surface of the second mirror 39 increases by α2 in addition to the incident angle β1 in the initial state. That is, β2 = β1 + α2 ... Equation (A1).

According to the law of reflection, the reflection angle is β2 as well as the incident angle β2. In this way, when the reflection surface of the second mirror 39 rotates α2, the incident angle β2 of the incident light passing through the second optical axis A2 and the reflection surface of the second mirror 39 are reflected along the third optical axis A3. Each of the reflection angles β2 of the emitted reflected light increases by α2 with respect to β1.

The angle formed by the second optical axis A2 and the third optical axis A3 in the initial state shown in FIG. 6A is twice β1 and is 2 × β1. On the other hand, the angle formed by the second optical axis A2 and the third optical axis A3 in the state of FIG. 6B showing the case where the second mirror 39 is rotated by α2 is twice β2 and is 2 × β2. Then, the angle formed by the second optical axis A2 and the third optical axis A3 in the initial state shown in FIG. 6A is 2 × β1, and the angle formed by the second optical axis A2 and the third optical axis A3 in the state shown in FIG. 6B. The following equation (A2) for obtaining the difference α1 from is obtained.
α1 = (2 × β2) − (2 × β1) ・ ・ ・ Equation (A2)

Substituting equation (A1) into equation (A2)
α1 = 2 × (β1 + α2)-(2 × β1) = 2 × α2 ... Equation (A3)
When converted to the equation of α2, α2 = (α1) / 2.

In the rotation mechanism 49, the mirror holding portion 50 and the third lens barrel are arranged so that the relationship between the rotation angle α2 of the mirror holding portion 50 and the rotation angle α1 of the third lens barrel portion 32 satisfies the relationship of the above formula (A3). Both parts 32 are rotated.

7 and 8 show an example of a specific configuration of the rotation mechanism 49. The rotation mechanism 49 of this example includes a pair of fixing members 51 and a gear mechanism composed of a plurality of gears. The gear mechanism is arranged between the second mirror accommodating portion 47 located at the rear end of the third lens barrel portion 32 and the mirror holding portion 50.

First, as shown in FIG. 7, as an example, the side wall 47A of the second mirror accommodating portion 47, the fixing member 51, and the side wall 50A of the mirror holding portion 50 are arranged in this order from the outside in the X direction, which is the axial direction of the rotation axis RO. Will be done. In FIG. 7, only the left side is shown when viewed from the incident side of the third lens barrel portion 32, but the same applies to the right side. Then, as shown in FIGS. 7 and 8 as an example, the rotation mechanism 49 has a first gear 61 and a second gear 62. Further, the rotation mechanism 49 has a first idler gear 63 and a second idler gear 64. The first gear 61, the first idler gear 63, and the second idler gear 64 are all external tooth gears having teeth on the outer periphery. As an example, in FIG. 8, the first idler gear 63 and the second idler gear 64 shown by the alternate long and short dash line indicate the virtual positions of the first idler gear 63 and the second idler gear 64 in the assembled state of the rotating mechanism 49.

The first gear 61 is provided on the inner surface of the side wall 47A of the second mirror accommodating portion 47 facing the fixing member 51. The first gear 61 rotates integrally with the third lens barrel portion 32 including the second mirror accommodating portion 47. The first gear 61 rotates the second gear 62 via the first idler gear 63 and the second idler gear 64. Since the second mirror accommodating portion 47 is a part of the third lens barrel portion 32 which is an example of the second cylinder portion, the first gear 61 is the "second cylinder portion provided in the second cylinder portion" according to the technique of the present disclosure. This is an example of "1 gear".

The first gear 61 has a rotating shaft RO, and can rotate around the rotating shaft RO as a central axis. The rotating shaft RO is inserted through the fixing member 51 and the mirror holding portion 50. The rotating shaft RO allows the first gear 61 and the second gear 62 to rotate coaxially. The third lens barrel portion 32 and the mirror holding portion 50 have a common rotation axis RO, and rotate coaxially with respect to the fixing member 51.

The second gear 62 is provided on the outer surface of the side wall 50A of the mirror holding portion 50 facing the fixing member 51. As the second gear 62 rotates, the mirror holding portion 50 also rotates. The second gear 62 is an internal tooth gear having teeth formed on the inner circumference of the ring-shaped member, and meshes with the second idler gear 64 on the inner peripheral side. The rotational force from the first gear 61 is transmitted to the second gear 62 via the first idler gear 63 and the second idler gear 64. Since the mirror holding portion 50 is an example of the first cylinder portion, the second gear 62 is an example of the “second gear provided in the first cylinder portion” according to the technique of the present disclosure.

The first idler gear 63 meshes with the first gear 61 and transmits the rotational force from the first gear 61 to the second idler gear 64. The first idler gear 63 includes a passive gear 63A, a shaft portion 63B, and a drive gear 63C. The passive gear 63A and the drive gear 63C are connected by being provided at both ends of the shaft portion 63B. The passive gear 63A and the drive gear 63C are fixed to the shaft portion 63B. The passive gear 63A, the drive gear 63C, and the shaft portion 63B rotate integrally with the fixing member 51. The shaft portion 63B penetrates the fixing member 51. In the passive gear 63A and the drive gear 63C, the passive gear 63A is arranged on the side wall 47A side and the drive gear 63C is arranged on the side wall 50A side with the fixing member 51 interposed therebetween. As described above, the first idler gear 63 is rotatably attached to the fixing member 51 via the shaft portion 63B.

The second idler gear 64 meshes with the first idler gear 63 and also meshes with the second gear 62 to transmit the rotational force input from the first gear 61 to the second gear 62 via the first idler gear 63. The second idler gear 64 is rotatably attached to the fixing member 51. The second idler gear 64 meshes with the drive gear 63C of the first idler gear 63. Further, the second idler gear 64 meshes with the second gear 62 on the inner peripheral side of the second gear 62. In the rotation mechanism 49, the rotation direction of the first gear 61 and the first gear 61 are configured by interposing two idler gears, the first idler gear 63 and the second idler gear 64, between the first gear 61 and the second gear 62. The rotation directions of the two gears 62 match.

As an example, as shown in FIG. 9, the third lens barrel portion 32 is rotated in order to adjust the rotation angle of the projection lens 10 from the state before rotation. At this time, the rotational force of the first gear 61 is first transmitted to the first idler gear 63. The rotational force transmitted to the first idler gear 63 is transmitted to the second idler gear 64, and further transmitted to the second gear 62.

Here, the gear ratio (ratio of the number of teeth) of the second gear 62 and the first gear 61 and the ratio of the radii are set so as to satisfy the following relational expressions (2) and (3). ..
First, when the pitches of the teeth of the first gear 61 and the teeth of the second gear 62 are the same, and T1 is the number of teeth of the first gear 61 and T2 is the number of teeth of the second gear 62, the second gear 62 and The gear ratio with the first gear 61 is set so as to satisfy the following relational expression (2).
T1: T2 = 1: 2 ... (2)
Further, assuming that r1 is the radius of the first gear 61 and r2 is the radius of the second gear 62, the ratio of the radius r1 and the radius r2 of the second gear 62 and the first gear 61 satisfies the following relational expression (3). Is set.
r1: r2 = 1: 2 ... (3)
By satisfying the relational expression (2) and the relational expression (3), the rotation angle of the mirror holding portion 50 becomes 1/2 of the rotation angle of the third lens barrel portion 32. When the pitches of the teeth of the first gear 61 and the second gear 62 are the same, the relational expression (2) and the relational expression (3) have a relationship in which if one is satisfied, the other is also satisfied. That is, if the number of teeth is set so as to satisfy the relational expression (2), the ratio of the radii satisfying the relational expression (3) is inevitably obtained.

After the rotation angle of the mirror holding portion 50 is adjusted by the rotation mechanism 49 according to the vehicle type of the automobile 12, the rotation mechanism 49 is fixed so as not to rotate. As an example, the first gear 61 and the second gear 62 are fixed to the fixing member 51 by a fastening member (not shown) such as a fixing bolt so that the mirror holding portion 50 cannot rotate. Further, the mirror holding portion 50 and the third lens barrel portion 32 may be fixed to the fixing member 51 by using an adhesive or the like so as not to rotate.

Next, the operation of the above configuration will be described. As an example, as shown in FIG. 3, the angle of the third optical system L3 of the projection lens 10 is adjusted according to the angle of the windshield 14 of the automobile 12 with respect to the dashboard 13. This adjustment work is performed, for example, by manually rotating the third lens barrel portion 32.

For example, from the initial state shown in FIG. 6A, the third lens barrel portion 32 is rotated around the rotation axis RO to a target angle according to the angle of the windshield 14. For example, as shown in FIG. 6B, the third lens barrel portion 32 is rotated clockwise about the rotation axis RO by a rotation angle α1. As a result, as shown in FIG. 9, the first gear 61 rotates with the rotation of the third lens barrel portion 32. When the first gear 61 rotates, the rotational force of the first gear 61 is transmitted to the second gear 62 via the first idler gear 63 and the second idler gear 64. Since two idler gears, a first idler gear 63 and a second idler gear 64, are provided between the first gear 61 and the second gear 62, the second gear 62 rotates in the same direction as the first gear 61.

Further, the gear ratio and the radius ratio of the first gear 61 and the second gear 62 are 1: 2, which satisfies the above relational expressions (2) and (3). Therefore, the second gear 62 rotates by the rotation angle α2, which is half of α1, with respect to the rotation angle α1 of the first gear 61. When the second gear 62 rotates, the mirror holding portion 50 provided with the second gear 62 also rotates by the rotation angle α2. As a result, the mirror holding portion 50 rotates at a rotation angle α2, which is 1/2 of α1, in conjunction with the rotation of the rotation angle α1 of the third lens barrel portion 32. As a result, when a bending optical system having a second mirror 39 for bending the second optical axis A2 to the third optical axis A3 is provided as in the projection lens 10, the third optical axis A2 is third with respect to the second optical axis A2. Even when the optical axis A3 is tilted, the geometrical optics relationship between the second optical axis A2 and the third optical axis A3 is properly maintained before and after tilting.

As an example, as shown in FIG. 6B, the projection lens 10 according to the technique of the present disclosure includes a second mirror 39 (an example of a reflecting portion) and a third optical system L3 (an example of a reflecting portion) that emits light reflected by the second mirror 39. (Example of emission optical system), mirror holding portion 50 (example of first cylinder portion), third lens barrel portion 32 (example of second cylinder portion), mirror holding portion 50, and third lens barrel portion 32. It is equipped with a rotation mechanism 49 (an example of a rotation mechanism) that rotates both. Then, the rotation mechanism 49 rotates the mirror holding portion 50 at a smaller angle than the third lens barrel portion 32. Therefore, even when the second mirror 39 (an example of the reflecting portion) that bends the optical axis is provided, the third optical system L3 (an example of the emitting optical system) can be tilted.

Further, as shown in FIG. 7 as an example, the rotation mechanism 49 rotates the mirror holding portion 50 (an example of the first cylinder portion) in conjunction with the third lens barrel portion 32 (an example of the second cylinder portion). That is, the rotation mechanism 49 transmits the rotational force of the third lens barrel portion 32 to the mirror holding portion 50, and the mirror holding portion 50 is rotated. As a result, the labor of the adjustment work is reduced as compared with the case where the third lens barrel portion 32 and the mirror holding portion 50 are rotated separately. Further, only one rotation mechanism 49 is required, and the space saving and simplification of the projection lens 10 can be realized.

Further, the rotation mechanism 49 rotates the mirror holding portion 50 at an angle α2 of 1/2 with respect to the rotation angle α1 of the third lens barrel portion 32 to be rotated. As a result, the geometrical optics relationship between the second optical axis A2 and the third optical axis A3 bent by the second mirror 39 is properly maintained before and after tilting.

Further, the rotation mechanism 49 has a first gear 61 provided in the second mirror accommodating portion 47 of the third lens barrel portion 32 and a second gear 62 provided in the mirror holding portion 50. The rotation mechanism 49 is compared with the case where the gear mechanism is not used because the rotation of the third lens barrel portion 32 and the rotation of the mirror holding portion 50 are interlocked by the gear mechanism including the first gear 61 and the second gear 62. The structure can be simplified. Further, according to the gear mechanism, the rotation angle of the third lens barrel portion 32 and the rotation angle of the mirror holding portion 50 can be set by setting the gear ratio and the radius ratio described above. Therefore, the rotation angle can be adjusted relatively easily as compared with the case where the gear mechanism is not used.

Further, in the projection lens 10, the rotation axis RO of the mirror holding portion 50 and the third lens barrel portion 32 is common. Therefore, the structure can be simplified as compared with the case where the rotation axes of the mirror holding portion 50 and the third lens barrel portion 32 are separately provided.

As an example, as shown in FIG. 4, the projection lens 10 has a first mirror 38 and a second mirror 39, and the second mirror 39 is arranged on the magnifying side of the first mirror 38. Further, the mirror holding portion 50 holds the second mirror 39. Assuming that the first mirror 38 is rotated, it is necessary to rotate a portion on the enlargement side of the first mirror 38, and the rotation mechanism 49 becomes large. On the other hand, in the projection lens 10 of this example, the second mirror 39 is rotated by rotating the mirror holding portion 50 with the rotation of the third lens barrel portion 32. As a result, when rotating the first mirror 38, it is necessary to rotate the parts after the first mirror 38, and the rotating parts of the projection lens 10 are large and heavy, but the rotating parts of the projection lens 10 are Since it is small and lightweight, the rotation operation is stable and the rotation mechanism 49 can be simplified.

Further, as the arrangement of the lens group of the third optical system L3 and the configuration for holding them increase in size, it is necessary to increase the size or increase the strength of the configuration for rotating the projection lens 10. Therefore, in the projection lens 10 of this example, as shown by the above relational expression (1), the distance LA3 from the second mirror 39 to the outlet of the projection lens 10 is twice as large as the distance LA3 from the entrance of the projection lens 10 to the first mirror. It is shorter than the sum of the distance LA1 to 38 and the distance LA2 from the first mirror 38 to the second mirror 39. In other words, twice the distance from the second mirror 39 (an example of the second reflecting part) to the exit lens LE is the distance from the entrance of the projection lens 10 to the first mirror 38 (an example of the first reflecting part). And the distance from the first mirror 38 to the second mirror 39 are set to be shorter than the total.

Therefore, the third optical system L3, which is the emission optical system, is relatively smaller and lighter than the first optical system L1 and the like. Therefore, twice the distance LA3 from the second mirror 39 to the exit of the projection lens 10 is the distance LA1 from the entrance of the projection lens 10 to the first mirror 38 and the distance LA2 from the first mirror 38 to the second mirror 39. In the projection lens 10 of this example, the rotational operation of the third lens barrel portion 32 having the third optical system L3 is stable as compared with the case where it is longer than the sum of.

Further, as shown in FIG. 5B as an example, when the rotation angle of the third lens barrel portion 32 is adjusted, a gap is generated in the portion where the third lens barrel portion 32 and the second lens barrel portion 31 are connected. There is. In the projection lens 10 of this example, the portion where the third lens barrel portion 32 and the second lens barrel portion 31 are connected is covered with the light-shielding member 48. Therefore, it is possible to prevent outside light from entering the projection lens 10 through the gap and light from leaking out of the projection lens 10 through the gap.

Further, the light-shielding member 48 has flexibility. As a result, the displacement of each member due to rotation can be absorbed as compared with the rigid light-shielding member, and the rotation operation is not hindered.

Also, depending on the installation environment of the projection lens 10, the installation environment of the projection lens 10 may become hot. As an example, when the projection lens 10 is attached to the dashboard 13 of the automobile 12, the area around the projection lens 10 becomes a high temperature environment under the scorching sun in summer. Therefore, the mirror holding portion 50 and the third lens barrel portion 32 are made of a metal material. On the other hand, the correction lens holding frame 36 of the first lens barrel portion 30 is made of a resin material. As described above, the mirror holding portion 50 or the like, which is required to have dimensional accuracy in order to arrange the second mirror 39 at an accurate position, is made of a metal material having a smaller coefficient of thermal expansion than the resin material or the like. On the other hand, at least a part of the cylinder portion other than the third lens barrel portion 32 such as the first lens barrel portion 30 is made of a resin material. As a result, weight reduction can be realized.

In the above first embodiment, an example in which the gear mechanism as the rotation mechanism 49 has the first gear 61 and the second gear 62 is shown, but the technique of the present disclosure is not limited to this. The number and arrangement of gears in the gear mechanism as the rotation mechanism 49, the number of teeth of each gear, and the like are appropriately set depending on the required rotational force, the accuracy in angle adjustment, and the like.

[Second Embodiment]
In the first embodiment, the example in which the rotation mechanism 49 is configured by the gear mechanism has been described, but the rotation mechanism is not limited to the gear mechanism, and is configured by the link mechanism like the rotation mechanism 91 of the second embodiment. May be done. In the second embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Hereinafter, a part different from the first embodiment will be described.

As shown in FIG. 10 as an example, the link mechanism as the rotation mechanism 91 according to the second embodiment transmits the rotational force applied to the third lens barrel portion 32 to the mirror holding portion 50. In the rotation mechanism 91 of the second embodiment, the fixing member 51, the side wall 47A of the second mirror accommodating portion 47, the link member 71, and the side wall 50A of the mirror holding portion 50 are arranged in this order from the outside in the X direction along the rotation axis RO. Has been done.

The fixing member 51 is provided with a rotating shaft RO on the inner surface facing the link member 71. The third lens barrel portion 32 and the mirror holding portion 50 are rotatably attached to the fixing member 51 via the rotation shaft RO. When the third lens barrel portion 32 (side wall 47A in FIG. 10) rotates about the rotation axis RO, the rotational force is transmitted to the mirror holding portion 50 via the link member 71. In the rotation mechanism 91, the length, angle, etc. of the pins or elongated holes provided in each member are set so that the rotation angle of the mirror holding portion 50 is smaller than the rotation angle of the third lens barrel portion 32. ..

More specifically, as shown in FIG. 11 as an example, the fixing member 51 is provided with a first elongated hole 72 in addition to the rotating shaft RO. The rotation axis RO is inserted through the side wall 47A of the third lens barrel portion 32 and the mirror holding portion 50. As a result, the side wall 47A and the mirror holding portion 50 of the third lens barrel portion 32 can rotate on a common rotation axis with respect to the fixing member 51. The first elongated hole 72 is a through hole having a longitudinal direction in the Y direction shown in FIG. 11 as an example. A second pin 75, which will be described later, is inserted into the first elongated hole 72.

The side wall 47A of the third lens barrel portion 32 is provided with a first pin 73 projecting toward the link member 71 at a position facing the link member 71. The first pin 73 is inserted into a second elongated hole 74 provided in the link member 71, which will be described later.

The link member 71 is a long plate-shaped member, and is arranged between the side wall 47A of the third lens barrel portion 32 and the side wall 50A of the mirror holding portion 50. The link member 71 has a second pin 75 protruding toward the fixing member 51 on the upper end side in the longitudinal direction (as an example, the Z direction shown in FIG. 11). The second pin 75 is inserted into the second elongated hole 74 described above. By engaging the second pin 75 with the second elongated hole 74, the link member 71 linearly moves along the Y direction in which the second elongated hole 74 extends.

Further, the link member 71 has a third pin 76 protruding toward the side wall 50A of the mirror holding portion 50 in the middle portion in the longitudinal direction (as an example, the Z direction shown in FIG. 11). The third pin 76 is inserted into a third elongated hole 77 provided in the mirror holding portion 50, which will be described later.

Further, the link member 71 has a second elongated hole 74 extending from the center in the longitudinal direction (as an example, the Z direction shown in FIG. 11) toward the lower end side. The second elongated hole 74 is a through hole extending along the longitudinal direction of the link member 71. The first pin 73 described above is inserted into the second elongated hole 74.

A third elongated hole 77 is formed in the side wall 50A of the mirror holding portion 50. The third elongated hole 77 is a through hole provided in a portion of the mirror holding portion 50 facing the link member 71. The third elongated hole 77 extends in a direction in which the longitudinal direction is inclined with respect to the Y direction and the Z direction. The tilt angle of the third elongated hole 77 is set so that the rotation angle of the mirror holding portion 50 is smaller than the rotation angle of the third lens barrel portion 32.

An operation example of the rotation mechanism 91 will be described with reference to FIGS. 12 and 13. As an example, the state shown in FIG. 12 is an initial state in which the third optical axis A3 and the second optical axis A2 shown in FIG. 5A are orthogonal to each other. On the other hand, the state shown in FIG. 13 as an example shows a state in which the third optical axis A3 is tilted upward by the rotation angle α1 from the initial state as shown in FIG. 5B as an example.

As an example, as shown in FIG. 12, in order to adjust the rotation angle of the projection lens 10 from the initial state before rotation, the third lens barrel portion 32 (as an example, the side wall 47A in FIG. 12) is rotated about the rotation axis RO. As an example, consider the case where the state shown in FIG. 13 is obtained.

As an example, when the third lens barrel portion 32 (as an example, the side wall 47A in FIG. 12) rotates from the initial state shown in FIG. 12, as shown in FIG. 13 as an example, the first pin 73 is centered on the rotation axis RO. In FIG. 12, it rotates clockwise. This rotation includes components that move the first pin 73 in the Z and Y directions. That is, the first pin 73 moves in the second elongated hole 74 of the link member 71 in the Z direction, and transmits the force of the component in the Y direction to the link member 71 via the second elongated hole 74. The link member 71 that receives the force in the Y direction from the first pin 73 is guided by the first elongated hole 72 and moves in the Y direction.

As the link member 71 moves in the Y direction, the third pin 76 moves linearly along the third elongated hole 77 (as an example, along the Y direction in FIG. 13). At this time, the third pin 76 transmits a force in the Y direction to the mirror holding portion 50 through the third elongated hole 77. When the mirror holding portion 50 receives a force in the Y direction from the third pin 76, the mirror holding portion 50 rotates about the rotation axis RO. The rotation angle of the mirror holding portion 50 at this time is set to be smaller than the rotation angle of the third lens barrel portion 32 by setting the inclination angle of the third elongated hole 77. More specifically, it is preferable that the rotation angle of the mirror holding portion 50 is set to be 1/2 of the rotation angle of the third lens barrel portion 32.

In this way, even if the rotation mechanism 91 configured by the link mechanism is used, the rotation of the third lens barrel portion 32 and the rotation of the mirror holding portion 50 can be linked.

In the second embodiment, the link mechanism as the rotation mechanism 91 shows a form example in which the link member 71 is provided, but the technique of the present disclosure is not limited to this. The number of link members in the link mechanism as the rotation mechanism 91, the shape of the elongated holes, the number or arrangement of pins, and the like are appropriately set depending on the required rotational force, the accuracy in angle adjustment, and the like.

[Third Embodiment]
In the third embodiment, the projection lens 10 has a third optical system L3 which is an optical system on the enlargement side of the second mirror 39 and a second optical system L2 which is an optical system on the reduction side of the second mirror 39. The case where the adjustment mechanism 80 for adjusting the second optical axis A2 and the third optical axis A3 is further provided will be described. In the third embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Hereinafter, a part different from the first embodiment will be described.

In the projection lens 10 according to this embodiment, as described above, various mechanisms are provided on the third optical system L3 side of the projection lens 10 in order to adjust the rotation angle. Therefore, when adjusting the positions of the second optical axis A2 and the third optical axis A3 in the projection lens 10, if the peripheral structure of the second mirror 39 is displaced to adjust the optical axis, the projection lens 10 is further adjusted. The structure on the L3 side of the third optical system becomes complicated. In addition, adverse effects such as a change in the adjusted rotation angle may occur. Therefore, in the projection lens 10 of the third embodiment, the adjustment mechanism 80 is provided so that the optical axis can be adjusted without displacing the peripheral structure of the second mirror 39.

As an example, as shown in FIG. 14, the adjustment mechanism 80 is provided in the second lens barrel portion 31. Specifically, the adjusting mechanism 80 is provided on the second lens barrel portion 31 on the enlarged side of the first mirror 38. The second lens barrel portion 31 is separated at a position where the adjusting mechanism 80 is provided, and is separated. The adjusting mechanism 80 adjusts the optical axis by relatively moving the third optical system L3 and the second optical system L2 at the separated portion of the second lens barrel portion 31. Here, the third optical system L3 is an example of the "optical system on the enlarged side of the reflecting portion" according to the technique of the present disclosure. Further, the second optical system L2 is an example of the "optical system on the reduction side of the reflecting portion" according to the technique of the present disclosure. Further, the adjusting mechanism 80 is an example of the "adjusting mechanism" according to the technique of the present disclosure.

More specifically, the adjusting mechanism 80 is provided on the first flange 81 provided on the third optical system L3 side of the second lens barrel portion 31 and on the second optical system L2 side of the second lens barrel portion 31. A second flange 82 is provided. The first flange 81 and the second flange 82 are flat plate-shaped portions extending outward from the outer periphery of the second lens barrel portion 31 along the XY plane shown in FIG. The first flange 81 and the second flange 82 face each other and are in surface contact with each other.

The first flange 81 and the second flange 82 are fastened by a fastening member. As an example, as shown in FIG. 15, the first flange 81 and the second flange 82 are provided with a plurality of adjusting holes 83. Further, the bolt 84 inserted through the adjusting hole 83 is screwed with the nut 85 to fasten the first flange 81 and the second flange 82. The inner diameter of the adjusting hole 83 is set to be larger than the outer diameter of the shaft portion of the bolt 84. As a result, it is possible to fasten the first flange 81 and the second flange 82 with the bolt 84 and the nut 85 while the second flange 82 is relatively displaced.

As an example, as shown in FIG. 16, when adjusting the optical axis, the adjustment mechanism 80 makes the third optical system L3 movable with respect to the second optical system L2. After the optical axis adjustment is completed, the first flange 81 and the second flange 82 of the adjustment mechanism 80 are fastened. As a result, the projection lens 10 functions as one.

In the present embodiment, the adjustment mechanism 80 allows the third optical system L3 and the second mirror 39 to move relative to the second optical system L2. As a result, the optical axis of the second mirror 39 and the second optical system L2 can be adjusted without adding a moving mechanism in addition to the rotating mechanism 49 to the peripheral structure of the second mirror 39. Further, as compared with the case where the peripheral structure of the second mirror 39 is displaced, the influence of the optical axis adjustment on the adjusted rotation angle in the third optical system L3 can be reduced.

Further, the adjustment mechanism 80 is provided in the second lens barrel portion 31 on the enlarged side of the first mirror 38. For this reason, the optical axis can be adjusted on the enlarged side of the intermediate image imaging position, and the optical axis adjustment accuracy is higher than that of adjusting the optical axis on the reduced side of the intermediate image imaging position. Is improved.

[Fourth Embodiment]
In the first embodiment, as an example, as shown in FIG. 3, the cover 16 is rotated with the rotation of the third optical system L3 in the tilt direction. However, as in the fourth embodiment, the cover 16 is rotated. Does not have to rotate in the tilt direction with respect to the dashboard 13. Further, as in the fourth embodiment, the projection lens 10 may have a flexible member 17 that covers the gap between the cover 16 and the third lens barrel portion 32. In the fourth embodiment, the same components as those in the first to third embodiments are designated by the same reference numerals, and the description thereof will be omitted. Hereinafter, a part different from the first embodiment will be described.

As an example, as shown in FIG. 17, the projection device 11 has a cover 16 that covers the third lens barrel portion 32. The cover 16 according to this embodiment is fixed to the dashboard 13. Further, a flexible member 17 is provided between the cover 16 and the third lens barrel portion 32 in the projection device 11 according to this embodiment. The flexible member 17 is provided in a region on the reduction side of the exit lens LE and on the expansion side of the mirror accommodating portion 47. As shown in FIG. 18 as an example, in the front view of the projection device 11 (Y direction view shown in FIG. 18 as an example), the flexible member 17 is the inner peripheral surface of the cover 16 and the outer circumference of the third lens barrel portion 32. It closes the gap between the faces.

Further, as described above, the cover 16 is fixed to the dashboard 13. That is, as shown in FIG. 19 as an example, the posture of the cover 16 is fixed regardless of the rotation of the third lens barrel portion 32. Therefore, when the third lens barrel portion 32 is tilted upward (as an example, when it is rotated clockwise in FIG. 19), the distance between the third lens barrel portion 32 and the cover 16 changes. Specifically, as shown in FIG. 19, as an example, the distance on the upper side of the third lens barrel portion 32 becomes smaller, and the distance on the lower side of the third lens barrel portion 32 becomes larger. At this time, the flexible member 17 partially expands and contracts to correspond to a change in the distance between the third lens barrel portion 32 and the cover 16. Specifically, in the flexible member 17, the portion covering the gap on the upper side of the third lens barrel portion 32 bends or contracts, and the portion covering the lower side of the third lens barrel portion 32 extends. That is, even before and after the rotation of the third lens barrel portion 32, the gap between the third lens barrel portion 32 and the cover 16 is covered by the flexible member 17.

By covering the gap between the third lens barrel portion 32 and the cover 16 in this way, foreign matter such as water or dust enters the gap between the cover 16 and the third lens barrel portion 32 in the flexible member 17. To prevent that. The flexible member 17 is made of a material having flexibility that can prevent foreign matter from entering and can cope with a change in the gap between the third lens barrel portion 32 and the cover 16 due to rotation. As an example, the flexible member 17 is formed from a material such as rubber, cloth, or leather. The flexible member 17 is an example of a "flexible member" according to the technique of the present disclosure.

In the present embodiment, the flexible member 17 covers the gap between the third lens barrel portion 32 and the cover 16, so that foreign matter such as water or dust enters the projection device 11. Is suppressed. Further, since the flexible member 17 has flexibility, it is possible to cope with a change in the gap between the third lens barrel portion 32 and the cover 16 by the rotation of the third lens barrel portion 32. That is, as compared with the case where the gap between the third lens barrel portion 32 and the cover 16 is covered with a member formed of a highly rigid material such as a metal plate, in the present embodiment, the third lens barrel portion 32 is rotated. It is possible to cover the gap between the third lens barrel portion 32 and the cover 16 while suppressing the influence.

In the above embodiment, an example of the form of the projection lens 10 having the first optical system L1, the second optical system L2, and the third optical system L3 is shown, but the technique of the present disclosure is not limited to this. As an example, the projection lens 10 may be a bending optical system having a second optical system L2 and a third optical system L3. In this case, the image forming unit 20 is provided at the incident side end of the second optical system L2.

In the above embodiment, an example in which the mirror accommodating portion 47 and the mirror holding portion 50 are rotated by one rotating mechanism 49 is shown, but the technique of the present disclosure is not limited to this. As an example, it may be configured to have a rotation mechanism for rotating the mirror accommodating portion 47 and a rotation mechanism for rotating the mirror holding portion 50, respectively.

The holding frame 37 and the holding frame 41 are not limited to the illustrated metal. However, metals are generally excellent in heat resistance. In addition, metal has relatively high rigidity and is hard to bend. This property of being hard to bend is a particularly necessary property because the projection lens 10 for the transportation device of this example is subject to vibration during traveling of the transportation device. Therefore, metal is suitable as a material for the holding frame 37 and the holding frame 41.

In the above embodiment, the correction lens LC and the exit lens LE, which are aspherical lenses, are exemplified as the lenses made of resin, but the present invention is not limited to this. It may be a spherical lens made of resin. Further, the lens made of resin may be the lens arranged on the most incident side.

In the above embodiment, the automobile 12 is exemplified as the transportation device, but the present invention is not limited to this. The transportation equipment may be a construction vehicle, a railroad, a ship, an airplane, or the like. Further, in the above embodiment, the projection lens 10 for transportation equipment has been exemplified, but the present invention is not limited to this. As an example, it may be a projection lens intended for outdoor use.

In the above embodiment, an example in which the image P is projected onto the windshield 14 by the projection device 11 is shown, but the technique of the present disclosure is not limited to this. As an example, the image P may be projected on the rear glass, the door glass, or the like instead of the windshield 14. Further, the image P does not have to be projected on the windshield 14, but may be projected on a projection curtain provided in the passenger compartment of the automobile 12.

As the image forming panel 21, a transmissive image forming panel using a liquid crystal display element (LCD; Liquid Crystal Display) may be used instead of the DMD. Further, instead of the DMD, a panel using a self-luminous element such as an LED (Light Emitting Diode) or an organic EL (Electro Luminescence) may be used. Further, a total reflection type mirror may be used instead of the specular reflection type first mirror 38 and the second mirror 39 of the above embodiment.

In the above embodiment, an example in which a laser light source is used as the light source 22 has been described, but the present invention is not limited to this, and a mercury lamp, an LED, or the like may be used as the light source 22. Further, in the above embodiment, the blue laser light source and the yellow phosphor are used, but the present invention is not limited to this, and a green phosphor and a red phosphor may be used instead of the yellow phosphor. Further, a green laser light source and a red laser light source may be used instead of the yellow phosphor.

The technique of the present disclosure can be appropriately combined with the various embodiments described above and various modifications. Further, not limited to the above embodiment, it goes without saying that various configurations can be adopted as long as they do not deviate from the gist.

The description and illustration shown above are detailed explanations of the parts related to the technology of the present disclosure, and are merely an example of the technology of the present disclosure. As an example, the above description of the configuration, function, action, and effect is an example of the configuration, function, action, and effect of a portion according to the art of the present disclosure. Therefore, unnecessary parts may be deleted, new elements may be added, or replacements may be made to the described contents and illustrated contents shown above within a range that does not deviate from the gist of the technique of the present disclosure. Needless to say. In addition, in order to avoid complications and facilitate understanding of the parts related to the technology of the present disclosure, the description contents and the illustrated contents shown above require special explanation in order to enable the implementation of the technology of the present disclosure. The explanation about common technical knowledge is omitted.

In the present specification, "A and / or B" is synonymous with "at least one of A and B". That is, "A and / or B" means that it may be only A, only B, or a combination of A and B. Further, in the present specification, when three or more matters are connected and expressed by "and / or", the same concept as "A and / or B" is applied.

All documents, patent applications and technical standards described herein are to the same extent as if the individual documents, patent applications and technical standards were specifically and individually stated to be incorporated by reference. Incorporated by reference in the book.

Claims (13)

A reflector that reflects the light incident from the electro-optical element,
An exit optical system that emits light reflected by the reflecting unit,
The first tubular portion having the reflective portion and
The second cylinder portion having the emission optical system and
A rotation mechanism for rotating both the first cylinder portion and the second cylinder portion is provided.
The rotation mechanism is a projection lens that rotates the first cylinder portion at a smaller angle than the second cylinder portion. The projection lens according to claim 1, wherein the rotation mechanism rotates the first cylinder portion in conjunction with the second cylinder portion. The projection lens according to claim 1 or 2, wherein the rotation mechanism rotates the first cylinder portion at an angle of 1/2 with respect to the angle at which the second cylinder portion is rotated. The projection according to any one of claims 1 to 3, wherein the rotation mechanism has a first gear provided in the second cylinder portion and a second gear provided in the first cylinder portion. lens. The projection lens according to claim 4, wherein the rotation axes of the first cylinder portion and the second cylinder portion are common. The reflecting portion has a first reflecting portion and a second reflecting portion provided on the enlarged side of the first reflecting portion.
The projection lens according to any one of claims 1 to 5, wherein the first cylinder portion has the second reflecting portion. Twice the distance from the second reflecting portion to the emitting lens is shorter than the sum of the distance from the entrance of the projection lens to the first reflecting portion and the distance from the first reflecting portion to the second reflecting portion. The projection lens according to claim 6. The projection lens according to any one of claims 1 to 7, wherein the portion where the second cylinder portion and the other member are connected is covered with a light-shielding member. The projection lens according to claim 8, wherein the light-shielding member has flexibility. In addition to the first cylinder portion and the second cylinder portion, another cylinder portion is provided.
The first cylinder portion and the second cylinder portion are formed of a metal material, and the first cylinder portion and the second cylinder portion are formed of a metal material.
The projection lens according to any one of claims 1 to 9, wherein at least a part of the other tubular portion is made of a resin material. Any of claims 1 to 10, further comprising an adjustment mechanism for adjusting the optical axis by relatively moving the optical system on the enlargement side of the reflection unit and the optical system on the reduction side of the reflection unit. The projection lens according to one item. A cover portion that covers the second cylinder portion and whose posture is fixed regardless of the rotation of the second cylinder portion.
The projection lens according to any one of claims 1 to 11, further comprising a flexible member which is a member that covers the gap between the second cylinder portion and the cover portion. A projection device provided with the projection lens according to any one of claims 1 to 12.

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