WO2016175214A1 - Lighting device and optical member - Google Patents

Abstract

[Problem] To provide a lighting device and an optical member, which are capable of collecting light emitted from a light source, and irradiating light that is parallel to an optical axis or light having an illuminance inversely proportional to the second power of the distance, even in the cases where there are restrictions in design. [Solution] An LED lighting device 100 is provided with: an LED element 1; and an optical member 130 that has a first beam shaping lens section 131, which outputs narrow-angle light by shaping a center luminous flux lc outputted from the LED element 1, and a second beam shaping lens section 132, which outputs narrow-angle light by shaping a peripheral luminous flux lo. The second beam shaping lens section 132 of the optical member 130 has a reflecting surface 132c and an output surface 132d,the reflecting surface 132c is designed under the restrictions where the maximum outer diameter D4 of the optical member 130 is smaller than a predetermined diameter, and the length L0 in the optical axis direction is longer than a predetermined length, and the output surface 132d is designed so as to refract the peripheral luminous flux lo such that the peripheral luminous flux is parallel to the optical axis 110a or inclined to the side opposite to the optical axis 110a, said peripheral luminous flux having been inclined to the optical axis 110a side by being reflected by the reflecting surface 132c.

Description

Illumination device and optical member

The present invention relates to an illumination device and an optical member that collect and irradiate light from a light source.

A light source that collects and irradiates light from a light source, has little color unevenness of the irradiated light, and suppresses a decrease in illuminance directly under the light source (see Patent Document 1).

This illuminating device has a light source, a first lens that collects light emitted from the light source, and a second lens that uses the collected light as parallel light. The first lens has a first reflecting surface whose parabolic shape is a cross-sectional shape that condenses incident light on the condensing surface. The second lens has a second reflecting surface whose parabolic shape is a cross-sectional shape that reflects the light incident from the connecting surface with the condensing surface and emits it as parallel light. With this configuration, the first reflecting surface collects light on the light collecting surface and mixes the colors, thereby reducing color unevenness, and using the light collecting surface as a pseudo light source, the light from the light collecting surface is used as the second reflecting surface. By using parallel light, a decrease in illuminance directly under the light source is suppressed.

JP 2013-45530 A

However, the conventional illuminating device makes the light from the condensing surface parallel light by making the cross-sectional shape of the second reflecting surface a parabolic shape. For example, the optical axis is a normal line for miniaturization. When the angle of the second reflecting surface with respect to the surface is increased, the light reflected by the second reflecting surface is inclined from the direction parallel to the optical axis toward the optical axis side, and the outgoing light is further refracted by the outgoing surface. There is a problem of tilting toward the optical axis.

Therefore, the object of the present invention is to collect light from a light source even when the design is limited, and to irradiate light parallel to the optical axis or light with an illuminance inversely proportional to the square of the distance. An apparatus and an optical member are provided.

[1] a semiconductor light emitting device;
A first shaping unit that shapes the central light beam emitted from the semiconductor light emitting element to emit narrow-angle light in the direction of the optical axis, and a peripheral light beam emitted from the semiconductor light emitting element to the periphery of the central light beam. And an optical member having a second shaping portion that emits narrow-angle light in the direction of the optical axis,
The second shaping unit of the optical member includes a reflective surface that reflects the peripheral light flux and an output surface that emits the peripheral light flux reflected by the reflective surface, and the output surface is the reflective surface. An illuminating device that refracts a peripheral luminous flux that has been reflected and tilted toward the optical axis so as to tilt parallel to or opposite to the optical axis.
[2] The optical member is designed in such a manner that a maximum outer diameter is smaller than a predetermined diameter, a length in a direction along the optical axis is larger than a predetermined length, and a minimum outer diameter is larger than a predetermined diameter. The lighting device according to [1].
[3] The first shaping portion of the optical member has a convex lens shape,
The second shaping portion of the optical member has an annular flat surface or curved surface shape having a predetermined angle with respect to a surface orthogonal to the optical axis, and is provided around the first shaping portion. -The illuminating device in any one of [3].
[4] A first shaping unit that shapes the central light beam emitted from the semiconductor light emitting element to emit narrow-angle light in the direction of the optical axis, and a peripheral light beam emitted from the semiconductor light emitting element to the periphery of the central light beam. A second shaping unit that shapes and emits narrow-angle light in the direction of the optical axis,
The second shaping unit of the optical member includes a reflective surface that reflects the peripheral light flux and an output surface that emits the peripheral light flux reflected by the reflective surface, and the output surface is the reflective surface. An optical member that refracts a peripheral luminous flux that has been reflected and tilted toward the optical axis so as to tilt parallel to or opposite to the optical axis.

According to the present invention, it is possible to collect light from a light source and irradiate light having an illuminance inversely proportional to the square of the distance or the light parallel to the optical axis even when the design is limited.

FIG. 1 is a longitudinal sectional view showing a schematic configuration example of a lighting device according to an embodiment of the present invention. FIG. 2 is a schematic view showing an optical path of light emitted from the LED light source. FIG. 3A is a diagram for explaining an example of a design method of a reflection surface and an emission surface of the second shaping lens unit. FIG. 3B is a diagram for explaining an example of a design method of the reflecting surface and the emitting surface of the second shaping lens unit. FIG. 4 is a schematic diagram illustrating an example of a light beam emitted from the optical member. FIG. 5 is a diagram illustrating an example of a light beam emitted when the emission surface of the second shaping lens unit is parallel to the reference surface. FIG. 6 is a diagram illustrating an example of the peripheral light beam emitted when the emission surface of the second shaping lens unit is parallel to the reference surface. FIG. 7 is a diagram illustrating an example of a light beam emitted when the emission surface of the second shaping lens unit is parallel to the reference surface.

Hereinafter, embodiments and examples of the present invention will be described with reference to the drawings. In addition, in each figure, about the component which has the substantially same function, the same code | symbol is attached | subjected and the duplicate description is abbreviate | omitted.

[Embodiment]
FIG. 1 is a longitudinal sectional view showing a schematic configuration example of a lighting device according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing an optical path of light emitted from the LED light source 110.

(Configuration of lighting device)
The illuminating device 100 includes an LED light source 110 using an LED element whose energization direction is a vertical direction, and an optical member 130 that shapes light emitted from the LED light source 110 and emits narrow-angle light. The LED element is an example of a semiconductor light emitting element, and an element such as a laser diode may be used. The optical member 130 is an example of an optical system.

(Configuration of LED light source)
The LED light source 110 includes the LED element 1 and, as an example, a heat dissipation structure including a copper block 111 and a radiator 117. The heat dissipation structure may be a resin substrate or an aluminum substrate. The LED light source 110 may further include a phosphor that emits light of the second color by being excited by the first color of light emitted from the LED element. The phosphor may be a powdery substance attached to the surface of the LED element 1 via a resin, or a phosphor containing a phosphor may be formed on the surface of the LED element 1. For example, an LED element that emits light of a blue color is used as the LED element 1, and a YAG phosphor that converts blue light into yellow light, a BOS phosphor, or the like as a phosphor. By using the LED light source 110, the blue light emitted from the LED element and the yellow light emitted from the phosphor are mixed and emitted to emit white light. Further, the color of light emitted from the LED light source 110 is not limited to a blue color, and the mixed color is not limited to white.

For example, the LED element 1 is formed so as to partially disperse and cover an n-type semiconductor substrate and the surface of the n-type semiconductor substrate, and a difference in refractive index from the n-type semiconductor substrate is 0.15 or less. A dielectric layer, an n-type semiconductor layer formed on the n-type semiconductor substrate via the dielectric layer, and in contact with the dielectric layer and a portion of the surface of the n-type semiconductor substrate that is not covered with the dielectric layer; a light-emitting layer formed on the n-type semiconductor layer, a p-type semiconductor layer formed on the light-emitting layer, an n-type electrode formed on the opposite side of the surface on which the dielectric layer of the n-type semiconductor substrate is formed, And a p-type electrode formed on the p-type semiconductor layer.

(Configuration of optical member)
The optical member 130 includes a first shaping lens unit 131 that shapes the light beam emitted from the LED light source 110 into, for example, parallel light or narrow-angle light, and an incident surface 132b on which the light beam emitted from the LED light source 110 is incident. A second shaping lens unit 132 that has a columnar shape and shapes the light beam incident on the incident surface 132b into parallel light or narrow-angle light. The 1st and 2nd shaping lens parts 131 and 132 are formed from transparent resins, such as an acrylic resin, for example. Here, the first shaping lens unit 131 is an example of a first shaping unit, and the second shaping lens unit 132 is an example of a second shaping unit. In FIG. 1, P indicates the position of the point light source.

The optical member 130 has a rotationally symmetric shape around the optical axis 110a, and has a maximum outer diameter D4, a minimum outer diameter D3, and a length L0 in the direction along the optical axis 110a.

The first shaping lens portion 131 is composed of a convex lens having a diameter D1 and a thickness L1, and has a flat incident surface 131a and a spherical exit surface 131b. Here, the light beam irradiated through the first shaping lens unit is referred to as a central light beam lc. As long as the central light beam lc is parallel light or narrow-angle light, a convex lens may be provided on the incident surface to make the exit surface flat, or convex lenses may be provided on the entrance surface and the exit surface.

The second shaping lens part 132 is formed in parallel with the optical axis 110a of the LED light source 110 with respect to the reference surface 132a arranged perpendicular to the optical axis 110a of the LED light source 110, and from the LED light source 110. A cylindrical incident surface 132b on which the emitted light (including light in the horizontal direction) enters, a reflective surface 132c that reflects the light incident on the incident surface 132b, and an output from which the light reflected by the reflective surface 132c is emitted. A surface 132d. Here, a light beam that is irradiated through the second shaping lens unit 132 is referred to as a peripheral light beam lo.

The reflection surface 132c of the second shaping lens portion 132 is a surface that approximates a surface obtained by rotating an aspherical shape such as a paraboloid or a Bezier curve with the optical axis 110a as the center. A method for designing the reflecting surface 132c will be described later. A reflecting mirror such as a metal plate may be used instead of the reflecting surface 132c of the second shaping lens portion 132.

The exit surface 132d of the second shaping lens unit 132 has a shape obtained by rotating a straight line or a curve having a predetermined angle with respect to a surface orthogonal to the optical axis 110a with the optical axis 110a as the center. That is, it is an annular plane or curved surface having a predetermined angle with respect to a plane orthogonal to the optical axis 110a. A method for designing the emission surface 132d will be described later.

Note that the first and second shaping lens portions 131 and 132 may be formed by cutting out a transparent resin or may be formed of glass.

(Restriction of optical member design)
As a premise, the illumination device 100 is limited in design, and at least the maximum outer diameter D4 of the optical member 130 is smaller than a predetermined inner diameter, and the diameter D2 of the cylindrical space constituting the incident surface 132b is set in the LED element 1. It is larger than a predetermined inner diameter so as not to interfere, the minimum outer diameter D3 is increased in accordance with the limitation of the diameter D2 of the cylindrical space, and the length L3 in the direction along the optical axis 110a of the cylindrical space constituting the incident surface 132b is set as the LED. It is assumed that the length needs to be larger than a predetermined length so as not to interfere with the element 1.

First, since the maximum outer diameter D4 and the diameter D2 and the minimum outer diameter D3 of the cylindrical space constituting the incident surface 132b are limited as described above, the angle θ with respect to the horizontal of the reflecting surface 132c increases, and the reflecting surface 132c reflects the light. The light beam tilted toward the optical axis 110a in the optical member 130.

In order to solve the above problem, the angle θ with respect to the horizontal direction of the reflecting surface 132c can be reduced by reducing the length L0 of the optical member 130 in the direction along the optical axis 110a, but first, there is a restriction due to the length L3. There are limits to this. Second, if the length L0 is reduced, the area of the reflecting surface 132c is reduced, and the ratio of reflecting the light emitted from the LED element 1 is reduced, resulting in a problem that the light collection efficiency is reduced. Therefore, L0 has a limit in order to maintain a certain efficiency.

Based on the above restrictions, the following design of the optical member 130 will be described.

(Optical member design)
3A and 3B are diagrams for explaining an example of a design method of the reflecting surface 132c and the emitting surface 132d of the second shaping lens unit 132. FIG.

(1) Design of the reflective surface 132c Although the light source of the LED element 1 is not strictly a point light source, it demonstrates below that the point light source P exists in the center of the thickness of the LED element 1, for example. A light ray loi incident on the incident surface 132b from the point light source P of the LED element 1 (loi is an arbitrary light ray of the peripheral light flux lo) is refracted in different directions depending on the emission angle, and each light ray loi is directed to the reflecting surface 132c. And incident. The reflection surface 132c is formed so that all the incident rays loi have an incident angle greater than the critical angle so as to be totally reflected. The second shaping lens part 132 is formed, for example, by forming a mold and injecting an acrylic resin melt into the mold.

However, due to the above design limitations, as shown in FIG. 3A, the light ray loi reflected at the angle α with respect to the normal line 132cn of the reflecting surface 132c in the optical member 130 from the direction parallel to the optical axis 110a (110a ′). It will be inclined to the optical axis 110a side (the center side of the optical member 130). In order to correct the inclination, the following emission surface 132d is designed. The auxiliary line 110a 'in FIG. 3A is a line parallel to the optical axis 110a.

The light beam loi reflected by the reflecting surface 132c is set in a direction parallel to the optical axis 110a or inclined in the direction opposite to the optical axis 110a (outside the optical member 130) in the optical member 130 from the direction parallel to the optical axis 110a. If the reflective surface 132c can be designed so that

(2) Design of Emitting Surface 132d As shown in FIG. 3B, the light ray loi reflected by the reflecting surface 132c is closer to the optical axis 110a side (center side of the optical member 130) in the optical member 130 than the direction parallel to the optical axis 110a. Therefore, when refracted at an incident angle β1 and a refraction angle β2 with respect to the normal line 132dn of the exit surface 132d, the refracted ray loi is in a direction parallel to the optical axis 110a or parallel to the optical axis 110a. A light exit surface 132d is formed by creating a surface that is inclined in the direction opposite to the optical axis 110a from the direction (outside of the optical member 130).

(3) Emission Light FIG. 4 is a schematic diagram illustrating an example of a light beam emitted from the optical member 130.

By designing the reflecting surface 132c and the emitting surface 132d as described above, the peripheral light flux lo of the outgoing light is inclined at least parallel to or opposite to the optical axis 110a. When the light source position is P ′, the illuminance of the light irradiated according to the distances d1, d2, and d3 from P ′ is inversely proportional to the square of the distance. This is because the areas S1, S2, and S3 irradiated with light at the distances d1, d2, and d3 are proportional to the squares of the distances d1, d2, and d3.

On the other hand, a case where the output surface 132d is not designed as described above and the reference surface is parallel to the output surface will be described below as a comparative example.

[Comparative example]
FIG. 5 is a diagram illustrating an example of a light beam emitted when the emission surface of the second shaping lens unit is parallel to the reference surface. FIG. 6 is a diagram illustrating an example of the peripheral light flux lo emitted when the emission surface of the second shaping lens unit is parallel to the reference surface.

As shown in FIG. 5, the optical member 130 ′ has a common configuration except for the optical member 130 and the exit surface, and thus the central light beam lc is the same as that of the embodiment.

On the other hand, as shown in FIG. 6, since the exit surface 132d ′ is not inclined like the exit surface 132d, the normal direction of the exit surface 132d ′ is parallel to the optical axis 110a (110a ′), and the peripheral light flux When an arbitrary light loj of lo is refracted on the exit surface 132d ′ at an incident angle γ1 and a refraction angle γ2, the refracted light loj is inclined toward the optical axis 110a (the center side of the optical member 130 ′).

FIG. 7 is a diagram illustrating an example of a light beam emitted when the emission surface of the second shaping lens unit is parallel to the reference surface. When the exit surface 132d ′ is provided as described above, the peripheral light beam lo of the emitted light is inclined at least toward the optical axis 110a, and the distances d1, d2, and the apparent distance from the light source position P ′ defined in FIG. The illuminance of the light irradiated according to d3 does not become inversely proportional to the square of the distance. This is because the area irradiated with light at the distance between the distances d1 and d2 is minimized, and then monotonically increases, and the areas irradiated with light at the distances d1, d2, and d3 are S1 ′, S2 ′, and S3 ′. Is not proportional to the square of the distances d1, d2, and d3.

(Effect of embodiment)
According to the above embodiment, the following effects can be obtained.
(1) Since the light reflected by the reflecting surface 132c inclined toward the optical axis 110a is designed to be inclined parallel to the optical axis 110a or opposite to the optical axis 110a on the output surface 132d due to the limitation of the lens design. Even when the design is limited, the light from the light source can be collected and irradiated with light parallel to the optical axis or light with an illuminance inversely proportional to the square of the distance.
(2) Since the same performance can be obtained with an outer diameter smaller than that of a conventional optical member, it contributes to space saving and material cost reduction.
(3) Since it is possible to irradiate light having an illuminance inversely proportional to the square of the distance, the present invention can be applied to spotlight illumination having a wide range of application distances from the LED illumination device 100 to the irradiation surface.

In addition, this invention is not limited to the said embodiment and said Example, A various deformation | transformation is possible within the range which does not change the summary of invention.

The present invention can be applied to illumination devices such as spotlight illumination and optical members used therefor.

DESCRIPTION OF SYMBOLS 1 ... LED element, 100 ... Illuminating device, 110 ... LED light source, 110a ... Optical axis, 111 ... Copper block, 117 ... Radiator, 130 ... Optical member, 131 ... 1st shaping lens part, 131a ... Incident surface , 131b... Exit surface, 132... Second shaping lens section, 132a... Reference surface, 132b... Entrance surface, 132c .. reflective surface, 132d. ... light rays

Claims (4)

A semiconductor light emitting device;
A first shaping unit that shapes the central light beam emitted from the semiconductor light emitting element to emit narrow-angle light in the direction of the optical axis, and a peripheral light beam emitted from the semiconductor light emitting element to the periphery of the central light beam. And an optical member having a second shaping portion that emits narrow-angle light in the direction of the optical axis,
The second shaping unit of the optical member includes a reflective surface that reflects the peripheral light flux and an output surface that emits the peripheral light flux reflected by the reflective surface, and the output surface is the reflective surface. An illuminating device that refracts a peripheral luminous flux that has been reflected and tilted toward the optical axis so as to tilt parallel to or opposite to the optical axis. The optical member is designed in such a manner that a maximum outer diameter is smaller than a predetermined diameter, a length in a direction along the optical axis is larger than a predetermined length, and a minimum outer diameter is larger than a predetermined diameter. Item 2. The lighting device according to Item 1. The first shaping portion of the optical member has a convex lens shape,
The second shaping portion of the optical member has a shape obtained by rotating a straight line or a curve having a predetermined angle with respect to a plane orthogonal to the optical axis around the optical axis, The illuminating device according to claim 1 or 2 provided in the periphery. A first shaping unit that shapes the central light beam emitted from the semiconductor light emitting element to emit narrow-angle light in the direction of the optical axis, and a peripheral light beam emitted from the semiconductor light emitting element to the periphery of the central light beam A second shaping unit that emits narrow-angle light in the direction of the optical axis,
The second shaping unit of the optical member includes a reflective surface that reflects the peripheral light flux and an output surface that emits the peripheral light flux reflected by the reflective surface, and the output surface is the reflective surface. An optical member that refracts a peripheral luminous flux that has been reflected and tilted toward the optical axis so as to tilt parallel to or opposite to the optical axis.

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