HK1154081B - Spectacles-type image display device - Google Patents

Description

Glasses type image display device

Technical Field

The present invention relates to a glasses-type image display device.

Background

Conventionally, as a glasses-type image display device, for example, a device including an image output unit held on a temple (temple) side of glasses and an eyepiece optical unit held adjacent to a lens of the glasses is suggested. Such a glasses-type image display device is configured such that image light of an electronic image to be displayed, which is output from an image output unit, is incident on an eyeball of a viewer through an eyepiece optical unit, whereby the viewer can see the image. In such a glasses-type image display device, generally, an electronic image and a background image transmitted through a glasses lens are superimposed and displayed on an eyeball (this is called "see-through display").

Known as examples of such techniques are: devices having a concave mirror blocking the front view and a plurality of projection mirrors (see, for example, JP5303056(a)) and devices provided with holographic optical elements on spectacle lenses (see, for example, JP2006209144 (a)). In addition, as the eyeglass type image display device related to these technologies, for example, a device configured to hold an image output unit through an eyeglass frame or the like to allow image light to enter from outside of an eyeglass lens (see, for example, JP2001522064(T)) and a device configured to configure an optical path to allow image light to enter the eyeglass lens (see, for example, JP2000511306(T)) are known.

Disclosure of Invention

However, according to the technique described in JP5303056(a), a complicated projection optical system is used in order to correct aberrations caused by using a large concave mirror. In addition, there are problems such as blocking caused by the size of the concave mirror and the need to increase the see-through function. In addition, according to the technique described in JP2006209144(a), since the wavelength selectivity of the hologram optical element is strong, a high-cost method (for example, using a light source such as a laser beam or using only a part of the wavelength with a high-performance filter) is required. In addition, with the hologram optical element, it is difficult to increase the adjustment function according to the diopter (curvature) of each viewer.

In light of the above, it is an object of the present invention to provide a glasses-type image display device which enables a viewer to see an external view and an electronic image simultaneously without blocking his/her external view, and which can be small, lightweight, and low-cost (a small number of components).

In order to solve the above problems, a glasses type image display device according to the present invention has: an image output unit disposed on the eyeglass frame and including a display element for displaying an image and a projection lens for enlarging and projecting the image; and a reflection unit that is disposed adjacent to at least one eyeglass lens and is configured to reflect image light output from the image output unit toward an eyeball of an observer when the observer wears the eyeglasses so that the observer can see a virtual image of the image, wherein the reflection unit is a reflection member having no refractive power, and an effective light flux output from the image output unit and reaching the eyeball of the observer is configured to: such that for an optical axis cross-section (including the cross-section of the optical axis) along at least one direction, the width of the effective light flux perpendicular to the optical axis is minimal at said reflecting unit. That is, in the optical system of the glasses-type image display device of the present configuration, the reflecting member substantially functions as an aperture stop for an optical axial section along at least one direction. In other words, the exit pupil position for an optical axial cross-section along at least one direction may be the reflective member.

Preferably, the smallest width of a cross-section perpendicular to the optical axis is less than 4mm, which 4mm is the average pupil diameter of a human being.

In addition, it is preferable that, for the reflection surface of the reflection member, a width in a direction parallel to the incident surface is smaller than a width in a direction perpendicular to the incident surface. In other words, the reflecting member functions as an aperture stop in an optical axis section parallel to the incident surface. In addition, the image output unit is provided on the eyeglass frame (i.e., light enters from the side), whereby the reflecting member is longitudinally long in shape.

Further, preferably, the display element is rectangular in shape, and is disposed such that a longitudinal direction of the rectangular shape corresponds to a minimum width direction of the reflection surface of the reflection member. In other words, even if the reflecting member is longitudinally long, the display element is laterally long.

In addition, for the effective light flux that is output from the image output unit and that reaches the eyeball of the viewer, it is preferable that a pupil position in the lateral direction, which is an exit pupil position for an optical axis cross section parallel to the incident surface of the reflection member, is located in the vicinity of the reflection member, a pupil position in the longitudinal direction, which is an exit pupil position for an optical axis cross section perpendicular to the incident surface of the reflection member, is located closer to the pupil of the eyeball of the viewer than the pupil position in the lateral direction. In other words, the reflecting member functions as an aperture stop for an optical axis section parallel to the incident surface, but it does not function as an aperture stop for an optical axis section perpendicular to the incident surface.

Further, preferably, the reflective member is embedded in the eyeglass lens.

In addition, it is preferable that an optical axis of the projection lens passes through the reflection member, and the projection lens or the image output unit including the projection lens is rotatably held around the reflection unit.

In addition, it is preferable that an optical axis of the projection lens passes through the reflection member, and the reflection unit is rotatably held by a rotation shaft located in a reflection surface of the reflection member.

In addition, for the image output unit, it is preferable to provide a deflection prism between the display element and the projection lens.

In addition, it is preferable that the display element is disposed to face a forward direction of the viewer, and light emitted from the display element is incident on the deflection prism, deflected by 50 ° to 70 °, and emitted toward the reflection unit.

In addition, it is preferable that the projection lens and the deflection prism are integrally molded.

Further, it is preferable that the projection lens and the deflection prism are held by a temple (endpiece) of the eyeglasses, the display element is held by a temple of the eyeglasses, and the display element is movable and adjustable in a direction perpendicular to a display surface.

Further, it is preferable that the distance between the projection lens and the deflection prism is adjustably maintained.

Further, it is preferable that the projection lens and the deflection prism are held by a temple of the eyeglasses, the display element is held by a temple of the eyeglasses, and the display element is movable and adjustable in a direction parallel to a display surface.

In addition, preferably, the display element is an organic EL.

Further, it is preferable that the display element is disposed at a position where a projection section with respect to the forward direction of the viewer does not cover the pupil of the viewer.

According to the present invention, it is possible to provide an eyeglass-type image display device which enables a viewer to see both an outside and an electronic image without obstructing an outside view and can realize features of small volume, light weight, and low cost.

Drawings

Fig. 1 is a partial block diagram schematically showing main components of a glasses-type image display device according to a first embodiment of the present invention;

FIG. 2 is a schematic diagram showing an example of a reflection unit for carrying out the present invention;

fig. 3 is a front view of the right eye side of a viewer when the viewer wears the glasses-type image display device in fig. 1;

fig. 4 is a front view showing a width in a short side direction of a rectangular reflection unit according to a first embodiment of the present invention;

FIG. 5 is a basic block diagram illustrating an optical element selected according to a first embodiment of the present invention;

fig. 6 is a ray diagram of an optical axis section along the transverse direction and an optical axis section along the longitudinal direction in the optical system according to the first embodiment of the present invention;

fig. 7 is a schematic view showing a configuration and a use state of a glasses-type image display device according to a second embodiment of the present invention;

FIG. 8 is a basic block diagram illustrating an optical element selected according to a second embodiment of the present invention;

fig. 9 is a schematic diagram illustrating an example of interpupillary adjustment according to a second embodiment of the present invention;

fig. 10 is a schematic diagram illustrating an example of interpupillary adjustment according to a second embodiment of the present invention;

fig. 11 is a schematic view schematically showing a glasses-type image display device according to a third embodiment of the present invention; and

fig. 12 is a schematic view schematically showing a glasses-type image display device according to a fourth embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(first embodiment)

Fig. 1 is a partial block diagram schematically showing main components of a glasses-type image display device according to a first embodiment of the present invention. In the schematic diagram, eyeballs 2 of the right eye of the viewer when he/she wears the glasses-type image display device 1 are also shown. As shown in this schematic diagram, the eyeglass type image display device 1 of the present embodiment has an image output unit 4 provided on a frame unit 3 of eyeglasses and a reflection unit 5 that reflects image light output from the image output unit 4 toward eyeballs 2 of a viewer.

The image output unit 4 has therein a display element (not shown in fig. 1) for displaying a two-dimensional image and a projection lens (not shown in fig. 1) for enlarging and projecting the two-dimensional image, and the image output unit 4 outputs image light through the projection lens. As the display element, a general-purpose display element such as a liquid crystal display element or an organic EL element can be used. It is well known that these general purpose display elements are low cost devices. In particular, when an organic EL element is used as a display element, a backlight is not required, and thus a small-sized and lightweight device requiring low power can be realized.

The reflection unit 5 is a reflection member having no refractive power disposed adjacent to the eyeglass lens, and is disposed to reflect the image light output from the image output unit 4 toward the eyeball 2 of the viewer so that the viewer can see a virtual image of the two-dimensional image when wearing the eyeglasses. As shown in fig. 2, (a) a front surface mirror, (b) a rear surface mirror, (c) a mirror embedded in an eyeglass lens, and (d) a total reflection prism, etc. may be used as the reflection unit 5. As the front surface mirror and the rear surface mirror, mirrors whose front surface and rear surface are treated with typical mirror coatings (e.g., metal deposition or dielectric multilayer films), respectively, can be used. When a reflecting mirror embedded in an eyeglass lens is used, the inclination angle can be reduced by refraction between the eyeglass lens and air. When a total reflection prism is used, refraction can be achieved without a mirror coating.

The spectacle frame 3 is fixed to the spectacle lens 6 (or the frame of the spectacle lens 6) and comprises studs 7 at both ends of the front face of the spectacle and temples 9 foldably connected by the studs 7 and hinges 8. The image output unit 4 according to the present embodiment is held by the temple 9 through the hinge 8, and is folded together with the temple 9 when the eyeglass frame 3 is folded.

In the above-described structure, the image light output from the image output unit 4, reflected by the reflection unit 5, and reaching the eyeballs 2 of the viewer passes through the space surrounded by the eyeglass lenses 6, the eyeglass frame 3 (and the face of the viewer). This configuration can reduce obstacles blocking the view of the viewer as much as possible, and does not cause any component to be disturbed (for example, by the image output unit 4) when the eyeglass frame 3 is folded.

Fig. 3 is a front view of the right eye side when the viewer wears the glasses-type image display device in fig. 1. As shown in fig. 3, in the glasses-type image display device according to the present embodiment, the reflection unit 5 is disposed at a position such that the reflection unit 5 does not cover the pupil 10 of the viewer with respect to the projection cross section with respect to the front direction of the viewer. In the present embodiment, the reflection unit 5 is provided at this position, and therefore the field of vision of the viewer can be sufficiently secured in a normal situation (when the viewer pays more attention to information around him/her than information from the glasses type image display apparatus), and the viewer can safely move around even when the viewer wears the glasses type image display apparatus according to the present embodiment.

In addition, as shown in fig. 3, in the glasses-type image display device according to the present embodiment, the reflection unit 5 is in the shape of a vertically long rectangle. On the other hand, the image output unit 4 and the display elements provided therein are in the shape of a laterally long rectangle. In other words, the apparatus is configured such that the longitudinal direction of the display element corresponds to the minimum width direction of the reflection unit, whereby image light can be guided to a narrow space between the glasses and the face even if the image is displayed long in the lateral direction. In addition, in the glasses-type image display device according to the present embodiment, since the reflection unit 5 is in the shape of a longitudinally long rectangle, there is a large tolerance in longitudinal slippage in a state where the device is mounted. In addition, if the tolerance of the vertical slipping caused by the vertically long reflecting unit is used as the image display area, the configuration according to the present embodiment can be used for a vertically long display screen (i.e., a vertically long display element).

Fig. 4 is a schematic diagram showing a width along a short side direction of the rectangular reflection unit according to the present embodiment. As described above, in the present embodiment, the image light output from the image output unit 4 is reflected by the reflection unit 5 and guided to the eye pupil 10 of the eyeball 2. Therefore, the reflection unit 5 is disposed obliquely with respect to the line of sight of the eyeball 2 (or the optical axis of the image light output from the image output unit 4). In other words, the size of the reflection unit 5 is different from its actual size with respect to the field of view of the viewer. In the present embodiment, the apparatus is configured such that the width of a cross section (a projection cross section along the line of sight direction) of the reflection unit 5 perpendicular to the optical axis is 4mm or less. The value of 4mm is based on the average diameter of the human pupil, and when the width of the cross section perpendicular to the optical axis of the reflection unit 5 is less than 4mm, a phenomenon called pupillary division perspective is achieved by which background light that is not obstructed by the reflection unit 5 passes through the eye pupil 10 and forms an image on the retina (amphilstrode), whereby the image light output from the image output unit 4 is superimposed on the background light.

Fig. 5 is a basic block diagram showing an optical element selected according to the present embodiment for explaining the optical system according to the present embodiment in more detail. In the optical system according to the present embodiment, as shown in fig. 5, illumination light emitted from a light source 11 is converted into substantially parallel light by an illumination lens 12 and is delivered to a display element 13 (for example, a liquid crystal display element). Thereafter, the display element 13 outputs image light containing image information, which is converted into converging light by the projection lens 14 and guided to the reflection unit 5. The reflection unit 5 reflects the image light incident from the projection lens 14 toward the eye pupil 10 of the eyeball 2.

As shown in fig. 5, the aperture of the reflection unit 5 is smallest in an optical axis cross section along the paper surface direction of the optical system according to the present embodiment. In other words, for an optical axis section parallel to the incident surface of the reflection unit 5, the reflection unit 5 functions as a substantial aperture stop in the optical system according to the present embodiment, or it can be said that there is an exit pupil position in the reflection unit 5. In this way, in the optical system according to the present embodiment, since the reflection unit 5 is the exit pupil position, the shape of the reflection unit 5 can be determined without considering the image shape (i.e., the shape of the display element). Therefore, in the present embodiment, as described above, even if the display element 13 is in the shape of a horizontally long rectangle, the reflection unit 5 may be in the shape of a vertically long rectangle.

For example, when a liquid crystal display element is used as the display element 13, it is preferable that the reflection unit 5 is disposed in the vicinity of the back focus position of the projection lens 14. For the liquid crystal display element, better image quality can be obtained by adopting an object-side telecentric optical system. That is, it is preferable to configure the device such that the back focus position is the exit pupil position. Therefore, by providing the reflection unit 5 as an optical element having a minimum aperture at the back focus position, a preferable configuration is obtained in the case of using a liquid crystal display element as the display element 13. In addition, with this configuration, since the image of the light source 11 is located near the reflection unit 5, light diffused from the image of the light source 11 is reflected by the reflection unit 5 in a condensed state, whereby improved luminance efficiency can be obtained.

It should be noted that when an organic EL display element is used as the display element 13, it is not necessary to employ a telecentric optical system. Therefore, it may be configured such that the reflection unit 5 is not disposed at the back focus position.

Fig. 6 is a schematic diagram showing a difference between (a) an optical axis section in the lateral direction (i.e., an optical axis section parallel to the incident surface of the reflection unit) and (b) an optical axis section in the longitudinal direction (i.e., an optical axis section perpendicular to the incident surface of the reflection unit) of the optical system according to the present embodiment. It should be noted that, in fig. 6, for the description with respect to the paper surface, the light reflected by the reflection unit 5 is represented as a straight line.

In fig. 6A and 6B, a principal ray on the optical axis, a marginal ray on the optical axis, a principal ray outside the optical axis, and a marginal ray outside the optical axis are indicated by a two-dot chain line, a solid line, a one-dot chain line, and a broken line, respectively. As shown in fig. 6A, in the optical system according to the present embodiment, the lateral light flux is defined by the reflection unit 5 (in other words, the reflection unit 5 functions as an aperture stop). Thus, marginal rays outside the optical axis intersect the optical axis. On the other hand, as shown in fig. 6B, since the reflection unit 5 has a sufficiently large aperture for the longitudinal direction, the reflection unit 5 does not function as a substantial aperture stop, but the eye pupil 10 functions as an aperture stop.

It should be noted that although the eyeglass type image display device 1 shown in the present embodiment is configured to display an electronic image to the right eye, it may be configured to display an electronic image to the left eye.

(second embodiment)

Fig. 7 is a block diagram schematically illustrating a glasses-type image display device according to a second embodiment of the present invention. In the schematic diagram, eyeballs 2 of his/her right eye when the viewer wears the glasses-type image display device 1 are also shown. As shown in the schematic diagram, the glasses-type image display device 1 according to the present embodiment is provided with an image output unit 4 located on a temple 9 of glasses and a reflection unit 5 that reflects image light output from the image output unit 4 toward an eyeball 2 of a viewer.

The image output unit 4 has a display element 13 therein for displaying a two-dimensional image and outputs image light. As in the case of the first embodiment, a general-purpose display element such as a liquid crystal display element and an organic EL element can be used as the display element 13. Thereafter, the image light output from the display element 13 (i.e., the image output unit 4) is incident on the deflection prism 15, deflected by 50 ° to 70 °, and exits toward the reflection unit. In the embodiment shown in fig. 7, the deflection prism 15 and the projection lens 14 are integrally molded, and the image light emitted from the deflection prism 15 and the projection lens 14 toward the reflection unit 5 is a converging light line.

Prisms having an apex angle of 30 °, 60 °, and 90 ° (referred to as 30 ° prisms) may be used as examples of the deflection prism 15. When a 30 ° prism is used, deflection of 60 ° can be obtained by causing image light to enter perpendicularly to a surface opposite to a 90 ° vertex angle, reflecting the image light by the surface opposite to a 60 ° vertex angle, totally reflecting the image light by the surface opposite to the 90 ° vertex angle, and emitting the image light from the surface opposite to the 30 ° vertex angle.

The reflection unit 5 is a reflection member having no refractive power, and is disposed such that when the viewer wears glasses, the reflection unit 5 reflects the image light output from the image output unit 4 toward the eyeball 2 of the viewer so that the viewer can see a virtual image of the two-dimensional image. As in the case of the first embodiment, (a) a front surface mirror, (b) a rear surface mirror, (c) a mirror embedded in a spectacle lens, and (d) a total reflection prism, etc. may be used as the reflection unit 5 (see fig. 2). It should be noted that, as in the case of the first embodiment, the reflection unit 5 is disposed at a position such that the reflection unit 5 does not cover the pupils 10 of the eyes of the viewer with respect to the projection section in the front direction of the viewer (see fig. 3). In addition, in the present embodiment, the reflection unit 5 is provided at this position, which makes it possible for the viewer to sufficiently secure his/her field of view, whereby the viewer can safely move around even when he/she wears the glasses-type image display device according to the present embodiment. Specifically, in the present embodiment, the deflecting prism 15 allows light to be incident on the reflecting unit 5 at a sharper angle than in the first embodiment, whereby the reflecting unit 5 can be disposed at a position where the field of view is less obstructed.

In the present embodiment shown in fig. 7, the projection lens 14 and the deflection prism 15 are held by the post 7 of the eyeglasses. In addition, the image output unit 4 is held by the temple 9 of the eyeglasses, and is movable and adjustable in a direction perpendicular to the display surface of the display element 13. With this configuration, the diopter can be adjusted by changing the distance between the display element 13 and the deflection prism 15. In addition, if the display element 13 is movable and adjustable parallel to the display surface, interpupillary adjustment may be performed. In addition, if the projection lens 14 and the deflection prism 15 are not integrally molded and the distance between the projection lens 14 and the deflection prism 15 is adjustably maintained, the diopter can be adjusted by adjusting the distance.

Fig. 8 is a basic block diagram showing optical elements selected in the present embodiment for describing the optical system according to the present embodiment in more detail. As shown in fig. 8, in the optical system according to the present embodiment, image light containing image information is output from the display element 13, deflected by the deflection prism 15, converted into converging light by the projection lens 14, and guided to the reflection unit 5. The reflection unit 5 reflects the incident image light from the projection lens 14 toward the eye pupil 10 of the viewer. In this case, the direction of the incident surface of the reflection unit 5 is the same as the direction of the paper surface, which is substantially horizontal as viewed from the viewer. As can be seen, also in the present embodiment, as in the case of the first embodiment, the light flux diameter of the optical axis section in the paper surface direction is smallest at the reflection unit 5. In other words, also in the present embodiment, the reflection unit 5 substantially functions as an aperture stop for an optical axis cross section in the direction along the incident surface. Therefore, also in the present embodiment, since the reflection unit 5 is the pupil position, the reflection unit 5 may be in the shape of a vertically long rectangle even if the display element 13 is in the shape of a horizontally long rectangle.

As can be seen in the basic block diagram shown in fig. 8, in the present embodiment, the distance between the display element 13 and the projection lens 14 is changed by changing the distance between the display element 13 and the deflection prism 15, whereby diopter adjustment can be performed. In addition, if the display element 13 is movable and adjustable in parallel to the display surface, the projection position of the display element 13 with respect to the pupil 10 of the eye is displaced in parallel, whereby a configuration capable of performing interpupillary adjustment can be obtained. In addition, the distance between the display element 13 and the projection lens 14 can be changed by adjusting the distance between the projection lens 14 and the deflection prism 15, whereby diopter adjustment can be performed.

Fig. 9 shows another example of interpupillary adjustment according to the present embodiment. Fig. 9A shows only the optical elements, while fig. 9B shows the interpupillary adjustment mechanism.

In fig. 9A, as in the case of the optical element shown in fig. 8, image light containing image information is output from the display element 13, deflected by the deflection prism 15, converted into converging light by the projection lens 14, and guided to the reflection unit 5. Thereafter, the reflection unit 5 reflects the incident image light from the projection lens 14 toward the eye pupil 10 of the viewer. At this time, the image output unit (in fig. 9A, including the display element 13, the deflection prism 15, and the projection lens 14) rotates around the reflection unit 5. Therefore, since the visible position on the pupil 10 of the eye of the viewer is shifted, interpupillary adjustment can be achieved.

According to the example of the interpupillary adjustment mechanism in fig. 9B, the image output unit 4 has the arc-shaped guide 21 centered on the reflection unit 5, and the image output unit 4 is held by the eyeglass frame 3 through this guide 21, whereby the image output unit 4 is held rotatably about the reflection unit, thereby realizing a glasses-type image display device capable of performing interpupillary adjustment.

Fig. 10 is a schematic diagram showing another example of interpupillary adjustment according to the present embodiment. Fig. 10A shows only the optical elements, while fig. 10B shows the interpupillary adjustment mechanism.

As in the case of the optical element shown in fig. 8, in fig. 10A, image light containing image information is output from the display element 13, deflected by the deflection prism 15, converted into converging light by the projection lens 14, and guided to the reflection unit 5. Thereafter, the reflection unit 5 reflects the incident image light from the projection lens 14 toward the eye pupil 10 of the viewer. At this time, the reflecting unit 5 rotates about an axis located in a reflecting plane of the reflecting unit. Accordingly, the visible position on the pupil 10 of the eye of the viewer is shifted, whereby interpupillary adjustment can be achieved.

According to the example of the interpupillary adjustment mechanism shown in fig. 10B, a groove having a concave surface 16 is formed in the eyeglass lens, and a through-hole 17 penetrating the eyeglass lens is provided on a part of the groove. For the reflection unit 5, the convex surface 19 is provided as a rear surface of the reflection surface 18, and a stem (knob)20 penetrating the through-hole 17 is formed. The concave surface 16 and the convex surface 19 are slidably fitted to each other, and the reflecting surface 18 is deflected by a shank 20 penetrating the through-hole 17. With this configuration, the centers of the curved surfaces of the concave surface 16 and the convex surface 19 will become the centers of rotation of the reflecting surface 18, thereby achieving rotation about an axis located in the reflecting surface. That is, a glasses-type image display device capable of performing interpupillary adjustment can be realized.

It should be noted that although examples of the interpupillary adjustment with reference to fig. 9 and 10 are shown using the second embodiment, these examples may also be appropriately performed by the first embodiment.

(third embodiment)

Fig. 11 is a basic block diagram schematically illustrating a glasses-type image display device according to a third embodiment of the present invention. In the present embodiment, in order to be used for both eyes, the use of the glasses-type image display device according to the second embodiment shown with reference to fig. 7 is expanded. In other words, the glasses-type image display device 1 according to the present embodiment is provided with: an image output unit 4 provided on a temple 9 of the glasses; a deflection prism 15 for deflecting the image light output from the image output unit 4; a projection lens 14 for enlarging and projecting the two-dimensional image displayed by the display element 13 in the image output unit 4; and a reflection unit 5 for reflecting the image light from the projection lens 14 toward the eyeball 2 of the viewer. These cells are arranged for the right eye and for the left eye. Here, each function of the present embodiment is similar to that of the glasses-type image display device according to the second embodiment, and thus similar description is omitted by assigning each same symbol in the drawings. In other words, the glasses-type image display device according to the present embodiment has the functions and effects possessed by the glasses-type image display device according to the second embodiment.

As shown in fig. 11, in the present embodiment, the incident angle of the image light is the same for the right eye and the left eye. In other words, a viewer wearing the glasses-type image display device according to the present embodiment sees one image in front of him/her. At this time, a three-dimensional image can be displayed by displaying inconsistent images to the right and left eyes. In addition, by reducing the width of the reflection unit 5 in the short side direction to less than 4mm (average pupil diameter of human beings), a see-through display can be realized, whereby a three-dimensional image can be superimposed on the background of the viewer, and thus a very realistic stereoscopic display can be realized. In addition, the angle of incidence of the image light may be angled inward for the amount of convergence of the eyeball.

(fourth embodiment)

Fig. 12 is a block diagram schematically illustrating a glasses-type image display device according to a fourth embodiment of the present invention. In the present embodiment, the use of the glasses-type image display device shown with reference to fig. 7 is expanded to be used for both eyes. In other words, the glasses-type image display device 1 according to the present embodiment is provided with: an image output unit 4 provided on a temple 9 of the glasses; a deflection prism 15 for deflecting the image light output from the image output unit 4; a projection lens 14 for enlarging and projecting the two-dimensional image displayed by the display element 13 in the image output unit 4; and a reflection unit 5 for reflecting the image light from the projection lens 14 toward the eyeball 2 of the viewer. These cells are provided for the right and left eyes. Here, the respective functions of the present embodiment are similar to those of the glasses-type image display device according to the second embodiment, and thus similar descriptions are omitted by assigning the same symbols to the drawings, respectively. In other words, the glasses-type image display device according to the present embodiment has the functions and effects possessed by the glasses-type image display device according to the second embodiment.

As shown in fig. 12, in the present embodiment, with respect to the right and left eyes of the viewer, the incident angle of the image light is directed outward when viewed from the viewer side. That is, a viewer wearing the glasses-type image display device according to the present embodiment sees any one of the images. At this time, by displaying different images between the right eye and the left eye, the viewer can selectively view a desired display. In other words, by putting the images for the right eye and for the left eye together, information of both images can be displayed. Therefore, the present embodiment is suitable for a case when the glasses-type image display device according to the present invention is used as an information providing device.

The present patent application claims priority from japanese patent application No.2009-200771, filed on 8/31/2009, the contents of which are incorporated herein by reference.

Claims (16)

1. An eyeglass-type image display device, comprising:

an image output unit disposed on a frame of glasses and including a display element for displaying an image and a projection lens for enlarging and projecting the image; and

a reflection unit disposed adjacent to at least one eyeglass lens and configured to reflect image light output from the image output unit toward an eyeball of a viewer when the viewer wears the eyeglasses so that the viewer can see a virtual image of the image,

wherein the reflection unit is a reflection member having no refractive power, and

an effective light flux output from the image output unit and reaching the eyeball of the viewer is set to: such that the width of the luminous flux perpendicular to the optical axis is smallest at the reflecting unit for an optical axis cross section along at least one direction.

2. The glasses-type image display device according to claim 1, wherein a minimum width of a cross section perpendicular to the optical axis is less than 4mm, the 4mm being an average pupil diameter of a human being.

3. The glasses-type image display device according to claim 1, wherein, with respect to the reflection surface of the reflection member, a width in a direction parallel to an incident surface is smaller than a width in a direction perpendicular to the incident surface.

4. The glasses-type image display device according to claim 3, wherein the display element is in a rectangular shape, and the display element is disposed such that a longitudinal direction of the rectangular shape corresponds to a minimum width direction of the reflection surface of the reflection member.

5. The eyeglass type image display device according to claim 1, wherein for an effective luminous flux that is output from the image output unit and that reaches the eyeball of the viewer, a pupil position in a lateral direction is located near the reflection member, and a pupil position in a longitudinal direction is closer to the pupil of the eyeball of the viewer than the pupil position in the lateral direction, wherein the pupil position in the lateral direction is an exit pupil position for an optical axis section parallel to an incident surface of the reflection member, and the pupil position in the longitudinal direction is an exit pupil position for an optical axis section perpendicular to the incident surface of the reflection member.

6. The glasses-type image display device according to claim 1, wherein the reflection member is embedded in the glasses lens.

7. The glasses-type image display device according to claim 1, wherein an optical axis of the projection lens passes through the reflection member, and the projection lens or the image output unit including the projection lens is rotatably held around the reflection unit.

8. The glasses-type image display device according to claim 1, wherein an optical axis of the projection lens passes through the reflection member, and the reflection unit is rotatably held by an axis that is located in a reflection surface of the reflection unit and is perpendicular to an incident surface.

9. The glasses-type image display device according to claim 1, wherein, for the image output unit, a deflection prism is provided between the display element and the projection lens.

10. The glasses-type image display device according to claim 9, wherein the display element is disposed to face a forward direction of the viewer, and light rays output from the display element are incident on the deflection prism, deflected by 50 ° to 70 °, and exit toward the reflection unit.

11. The glasses-type image display device according to claim 9, wherein the projection lens and the deflection prism are integrally molded.

12. The glasses-type image display device according to claim 9, wherein the projection lens and the deflection prism are held by a temple of the glasses, the display element is held by a temple of the glasses, and the display element is movable and adjustable in a direction perpendicular to a display surface.

13. The glasses-type image display device according to claim 9, wherein a distance between the projection lens and the deflection prism is adjustably maintained.

14. The glasses-type image display device according to claim 9, wherein the projection lens and the deflection prism are held by a temple of the glasses, the display element is held by a temple of the glasses, and the display element is movable and adjustable in a direction parallel to a display surface.

15. The glasses-type image display device according to claim 1, wherein the display element is an organic EL.

16. The eyeglass type image display device according to claim 1, wherein, with the reflection unit, a projection cross section with respect to a front direction of the viewer is provided at a position such that the projection cross section does not cover a pupil of the viewer.