JPH06308408A - Video display device - Google Patents

Abstract

PURPOSE:To provide a video display device which is constituted so that a video is displayed on respective both left and right eyes by using only one deflector in the horizontal direction and by which a wide viewing angle, high resolution and high luminance can be obtained through it is comparatively small in size and the constitution thereof is inexpensive. CONSTITUTION:After a modulated light beam from a light source part with an He-Ne laser 1, an AOM 3, an ND filter 5 or the like and which forms the light beams for both left and right eyes is scanned in the vertical direction by a galvanometer scanner 7, split to two for both left and right eyes by a beam splitter 8, respectively made incident on the different deflecting surfaces of a polygon mirror 11 and scanned in a horizontal direction at a same time, it is guided to eyeballs 16a and 16b through optical systems 12a and 12b. At this time, the respective devices are constituted so as to satisfy such pupil conjugate relation that the first deflecting surface and the second deflecting surface respectively become entrance pupils of both left and right eyes and the left and right eyeballs 16a and 16b of a user respectively become exit pupils. Then, the video is directly displayed on the retinae of the eyeballs of the user.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device for displaying an image directly on the retina of a user's eyeball using a light beam.

[0002]

2. Description of the Related Art As a conventional image display device for displaying an image on the retina of a user's eyeball using a light beam, there is, for example, one disclosed in Japanese Patent Laid-Open No. 4-100088. In this conventional example, laser light emitted from a light source is modulated according to image information, and two-dimensional scanning is performed by a scanning optical system to display an image on the retina of the eyeball of the user. Compared with a projection type image display device that projects on a screen, this conventional example obtains a good image without causing so-called speckle noise, in which laser light is scattered and scattered, with a small amount of light and power consumption. It has the following characteristics.

[0003]

However, the above-mentioned conventional image display device requires two components for each of the left and right eyes in order to be configured as a device for the left and right eyes. The size of the device becomes large, resulting in cost increase. Further, a detector is provided in the deflector or the like in order to synchronize the images of the left and right eyes, and it is necessary to control the horizontal modulation of the left and right eyes by the synchronization signal from the detector, which complicates the apparatus.

The present invention has been made in view of the above problems, and provides a video display device which can obtain a wide angle of view, high resolution and high brightness while having a relatively small size and an inexpensive structure. The purpose is to

[0005]

To this end, the image display device of the present invention forms a light beam for the left and right eyes in the image display device for displaying the image directly on the retina of the eyeball of the user. And a light source unit for vertically and horizontally
At least two deflectors that scan in one direction, and an optical system that guides the light beam scanned in two directions, vertical and horizontal, to each of the left and right eyes of the user. The second deflecting surface serves as an entrance pupil, and the left and right eyeballs of the user satisfy the pupil conjugate relationship such that they serve as exit pupils.

[0006]

In the present invention, the light beams for the left and right eyes emitted from the light source section are deflected by the first deflector in the direction perpendicular to the left and right pupils of the user, and then the second deflected light beam. It is deflected horizontally by the instrument with respect to the user's pupil.
At this time, since the deflecting surfaces of the first and second deflectors serve as entrance pupils and the pupils of the left and right eyes of the user respectively serve as exit pupils, the retinas of the left and right eyes are located. The image is displayed on.

At this time, since the image recognized by the user by the image display device of the present invention is formed directly on the retinas of the left and right eyeballs by the light beam, the utilization efficiency of the light beam is increased and the light amount is very small. A high-luminance image can be obtained. Further, since high-resolution optical systems are used for the left and right eyes, respectively, wide-angle and high-resolution image display can be performed. In addition, since the deflector, which is an expensive and power-consuming component, is shared by the left and right eyes, the number of components is reduced. Moreover, since the horizontal scanning of the left and right eyes is performed by one deflector, the images can be easily formed on the left and right eyes without performing control for synchronizing the images of the left and right eyes in the horizontal direction. be able to. Further, since all the deflecting surfaces and the pupil positions of the left and right eyes of the user have a pupil conjugate relationship, the reflecting area of the deflecting surface of the deflector becomes very small, and the deflector itself becomes smaller and lighter. . Therefore, it is possible to provide a video display device that is compact, inexpensive, and labor-saving.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a first embodiment of an image display device of the present invention, and FIGS. 2A and 2B are development views of an optical system of the first embodiment. It should be noted that FIG. 2A shows a direction horizontal to the paper surface, and FIG. 2B shows a direction vertical to the paper surface.

In FIGS. 1 and 2A and 2B,
A light beam emitted from a He-Ne laser 1 as a light source is condensed by a convex lens 2 and introduced into an AOM (acousto-optic element) 3 which is a light modulation element, where a video information signal (not shown) ) Is modulated (light modulation). By this light modulation, the electric signal is the intensity of the light wave,
Converted to changes in frequency, phase, plane of deflection, etc. The modulated light beam is made into a parallel light flux again by the convex lens 4, the light intensity is attenuated by the ND filter 5 which is a neutral density (achromatic color) filter that does not show spectral selective absorption, and then the light beam is condensed by the condenser lens 6. The light is focused on the reflecting surface of the galvanometer scanner 7, which is a vertical deflector. In the galvanometer scanner 7, the deflection is performed in synchronization with the video signal and the count value of the rotation number of the polygon mirror 11.

The light beam deflected by the galvanometer scanner 7 is introduced into the beam splitter 8. In the beam splitter 8, a part of the light beam is transmitted and a part of the light beam is reflected in a direction orthogonal to the transmitted light, and then the plane mirror 9
Is made parallel to the transmitted light. Note that FIG.
In (a) and (b), the configuration after the beam splitter 8 is shown based on the right eye system, and the left eye system is partially omitted.

Each of the transmitted and reflected light beams is imaged by the condenser lens 10 (10a, 10b) on the corresponding reflecting surface of the polygon mirror 11 which is a rotary polygon mirror. At that time, the reflection surfaces of the galvanometer scanner 7 and the polygon mirror 11 are pupil conjugate. Polygon mirror 1
Since 1 rotates at a constant speed (counterclockwise), the incident light beam can be scanned horizontally with respect to the left and right eyes of the user. The polygon mirror 11 and the galvanometer scanner 7 described above are driven by a drive mechanism (not shown). The light beam deflected by the polygon mirror 11 is scanned in the horizontal direction, and then the polygon mirror 1 is scanned.
The optical system 12 (12a, 12a disposed after the reflecting surface 1)
By b), an image is formed on the retinas of the left and right eyeballs to form an image.

Next, the optical system 12 will be described in detail with reference to FIG. Each optical element forming this optical system is arranged at such a power that it becomes an exit pupil of the optical system 12 including the correction optical system at the pupil positions of the left and right eyes of the user. The light beam scanned by the polygon mirror 11 has a concave lens 13
Concave mirror 14 (14a, 14b) through (13a, 13b)
It is incident on b). The concave mirrors 14a and 14b have a size capable of covering the reflection area of the light beam scanned in the horizontal direction and the vertical direction, and the incident light beam is corrected by the correction optics arranged after the concave mirrors 14a and 14b. System 15
The aberration is removed at (15a, 15b), and an image is formed on the retina of the left and right eyeballs 16 (16a, 16b) of the user.

In the first embodiment, the condenser lens 10 (10a, 10b) is located at any position between the galvanometer scanner 7 and the polygon mirror 11 as long as the pupil conjugate relationship is established. It may be placed at. Further, the concave lens 13, which is one of the optical components of the optical system 12, is not limited to the position shown in the figure, and the optical system 12
It may be arranged at any position as long as it is inside.

FIG. 3 is a diagram showing the configuration of the second embodiment of the image display apparatus of the present invention, and FIGS. 4A and 4B are development views of the optical system of the second embodiment. Note that FIG. 4A shows the horizontal direction on the paper surface, and FIG. 4B shows the vertical direction on the paper surface.

In FIGS. 3 and 4 (a) and (b),
A light beam emitted from a He-Ne laser 21 as a light source is condensed by a convex lens 22 and introduced into an AOM (acousto-optic element) 23 which is a light modulation element, where it is modulated according to a video signal (not shown). . The modulated light beam becomes a parallel light beam again by the convex lens 24, and N
The light intensity is attenuated by the D filter 25 and then reflected by the plane mirror 26, and the reflected light beam is introduced into the beam splitter 27. Beam splitter 2
In FIG. 7, a part of the light beam is transmitted, a part is reflected in a direction orthogonal to the transmitted light, and then is made parallel to the transmitted light by the plane mirror 28. 4A and 4B, the configuration after the beam splitter 27 is shown based on the right eye system, and the left eye system is partially omitted.

The transmitted and reflected light beams are respectively imaged by the condenser lenses 29 (29a, 29b) on the corresponding reflecting surfaces of the polygon mirror 30 which is a rotary polygon mirror. Since the polygon mirror 30 rotates at a constant speed (counterclockwise), the incident light beam can be scanned horizontally with respect to the left and right eyes of the user.

The light beam scanned in the horizontal direction by the polygon mirror 30 includes an optical system 34 (34a, 34b) including a correction optical system arranged after the reflecting surface of the polygon mirror 30.
Of the polygon mirror 30 and the galvanometer scanner 3 by the condenser lens 31 (31a, 31b).
2 (32a, 32b) reflecting surfaces have a pupil conjugate relationship,
It is incident on the galvanometer scanner 32. In the galvanometer scanners 32a and 32b, the deflection is performed in synchronization with the video signal and the count value of the number of rotations of the polygon mirror 30 which is the deflector in the horizontal direction. The light beams scanned on the galvanometer scanners 32a and 32b are
An image is formed on the retinas of the left and right eyeballs and becomes an image.

Next, the optical system 34 including the correction optical system will be described in detail with reference to FIG. Each optical element that constitutes this optical system is arranged at such a power that it becomes the exit pupil of the optical system 34 including the correction optical system 35 (35a, 35b) at the pupil positions of the left and right eyes of the user. Polygon mirror 3
The light beam scanned at 0 has a condenser lens 31 (31a, 31a,
31b) by the galvanometer scanner 32 (32
a, 32b) and the galvanometer scanner 32
Is vertically deflected by the concave mirror 33 (33a, 33b)
Is incident on. The concave mirrors 33a and 33b have a size capable of covering the reflection area of the light beam scanned in the horizontal and vertical directions, and the incident light beam has a concave mirror 3a.
The correction optical system 35 (35
a, 35b) the aberration is removed and the left and right eyeballs 36 of the user are removed.
An image is formed on the retina of (36a, 36b).

In the second embodiment, the condenser lens 29 (29a, 29b) is located at a position where a pupil conjugate relationship is established, from the plane mirror 26 to the polygon mirror 30.
It may be arranged at any position up to. Further, the galvanometer scanner 32, which is one of the optical components of the optical system 34 including the correction optical system, is located at a position where a pupil conjugate relationship is established between the deflection surfaces between the beam splitter 27 and the polygon mirror 30. It may be arranged at any position.

Further, in the first and second embodiments described above,
Lasers 1 and 21 that are light sources and AOM that is a modulator
3 and 23 are used one by one because the left and right eye systems are shared, but by using two each, the left eye system and the right eye system are made independent, and the light beams from the respective light sources are individually modulated. Alternatively, different images may be displayed on the left and right eyes of the user. In that case, higher resolution or stereoscopic viewing is possible. Furthermore, in the above-mentioned optical system, the height of the image is y,
If the horizontal scanning angle is θ _X , the focal length is f _x , the vertical scanning angle is θ _y , and the focal length is f _y , then a light beam is obtained if the relationship of y = f _x × θ _X is established in the horizontal direction. Is to perform uniform velocity scanning on the image plane, and if the relation of y = _fy × arc sin θ _y is established in the vertical direction, the light beam will perform similar uniform velocity scanning. It is desirable for the system to have a configuration conforming to these relationships.

FIG. 5 is a diagram showing the configuration of a third embodiment of the image display device of the present invention. In FIG. 5, H as a light source
The light beam emitted from the e-Ne laser 41 is condensed by the convex lens 42, is introduced into an AOM (acousto-optic element) 43 which is a light modulation element, and is modulated there according to a video signal (not shown). The modulated light beam becomes a parallel light beam again by the convex lens 44, and the ND filter 45
The light intensity is attenuated by the galvanometer scanner 46 and then vertically deflected by the galvanometer scanner 46. The light beam deflected only in the vertical direction is condensed by the condenser lens 47 on the deflection surface of the galvanometer scanner 48, and is deflected in the vertical direction by the galvanometer scanner 48.

The light beam scanned two-dimensionally in this manner has its principal ray made substantially parallel to the optical axis by the lens 54 of the optical system 51 arranged after the deflection surface of the galvanometer scanner 48, and the beam splitter It is incident on 49. In the beam splitter 49, a part of the incident light beam is reflected and a part is transmitted. The reflected light beam is imaged on the retina of the user's right eye 52a by the correction optical system 53a, and the transmitted light beam is collimated by the plane mirror 50 to the reflected light and then corrected by the correction optical system 53b. An image is formed on the retina of the left eyeball 52b.

In the above description, the galvanometer scanner 46 for vertically scanning the light beam and the galvanometer scanner 48 for concentrating the vertically scanned light beam by the condenser lens 47 have their respective deflection surfaces in a pupil conjugate relationship. In the galvanometer scanner 46, the deflection is performed in synchronization with the video signal and the count value of the number of rotations of the galvanometer scanner 48 which is a deflector in the horizontal direction. The light beam scanned on the galvanometer scanner 482 is imaged on the retinas of the left and right eyeballs by the optical system 51 including the correction optical system 53 (53a, 53b) to form an image.

Next, the optical system 51 including the correction optical system will be described in detail with reference to FIG. Each optical element forming this optical system is arranged at such a power that it becomes an exit pupil of the optical system 51 including the correction optical system 53 (53a, 53b) at the pupil positions of the left and right eyes of the user. The light beam scanned by the galvanometer scanner 46 is condensed by the condenser lens 47 on the galvanometer scanner 48, and is horizontally deflected by the galvanometer scanner 48. The beam splitter 49 has a size capable of covering the reflection area of the light beam scanned in the horizontal direction and the vertical direction, and the incident light beam has a correction optical system 53 a arranged after the beam splitter 49. , 53b, the aberration is removed, and images are formed on the retinas of the left and right eyeballs 52 (52a, 52b) of the user.

In the third embodiment, the galvanometer scanner 46, which is the first deflector, performs vertical deflection, and the galvanometer scanner 4 that is the second deflector.
Although horizontal deflection is performed in No. 8, the order of this deflection may be reversed. The galvanometer scanner 48, which is a horizontal deflector, may be replaced with a polygon mirror. Further, in the first to third embodiments, it is possible to achieve higher resolution by disposing at least one anamorphic optical element in each scanning optical system.

FIG. 6 is a view showing the arrangement of the light source section of the fourth embodiment of the image display device of the present invention. In FIG. 6, a white laser 61 including R (red), G (green), and B (blue) light elements is used as a light source, and a light beam emitted from the white laser 61 is emitted by a dichroic prism 62a. Only the laser light of the R element is reflected, and the laser light of the other G and B elements is transmitted. With respect to the transmitted laser light, only the laser light of the element G is reflected by the dichroic prism 62b, and the laser light of the element B is transmitted. The transmitted laser light of the R, G, and B elements is condensed by the convex lenses 63a, 63b, and 63c, respectively, and the AOM (acousto-optical element) 64 that is a light modulation element is collected.
a, 64b, 64c, where it is modulated in accordance with a video signal (not shown).

The modulated R, G, B laser beams are respectively
The convex lenses 65a, 65b, 65c form a parallel light beam. Among them, the R laser light is reflected by the plane mirror 66 and is combined with the G laser light by the dichroic prism 67a. The laser light that combines these R and G is
As a result of being reflected by the plane mirror 66b and being combined with the B laser light by the dichroic prism 67b,
The three elements R, G, and B are each modulated to be a combined laser beam, which is returned to the original optical axis and reflected, and the ND filter 68 attenuates the light intensity.

The light source section (white lasers 61 to ND having the above structure
The filter 68) can be applied to the first to third embodiments described above. That is, in the case of the first embodiment shown in FIGS.
b to the part from the plane mirror 26 to the optical systems 34a and 34b in the case of the second embodiment of FIGS. 3 and 4, and to the galvanometer scanner 46 in the case of the third embodiment of FIG. By applying it to the part up to the optical system 51, it is possible to form a color image on the retinas of the left and right eyeballs of the user even though the configuration uses only one white laser as a light source.

Since the white laser used as the light source in the fourth embodiment is a gas laser and a plurality of AOMs which are modulators are also used, it is possible that the device becomes large. In that case, the part from the light source 61 to the ND filter 68 and the part subsequent thereto is made a device that can be separated, and the light source part shown in FIG. Installed in a position away from the ND filter 68 (the condenser lens 6 to the optical systems 12a and 12b in FIG. 1, the plane mirror 26 to the optical systems 34a and 34b in FIG. 3 and the galvanometer scanner 4 in FIG. 5).
It is also possible to mount only 6 to the optical system 51) on the head or the like.

Although a gas laser is used as a light source in each of the above embodiments, a semiconductor laser or LED may be used instead. In this case, since the light source can be directly modulated, the device can be simplified and downsized. Further, although a concave mirror is used as one of the optical components in the scanning optical system, a plane mirror can be used by appropriately changing the power arrangement of the lens. In addition, an AOD (acousto-optic deflector) can be used as a deflector for vertical deflection in each of the above embodiments. Further, in each of the above embodiments, all the beam splitters can be replaced with half mirrors, and all the dichroic prisms can be replaced with dichroic mirrors.

[0031]

As described above, since the image recognized by the user by the image display device of the present invention is directly formed on the retinas of the left and right eyeballs by the light beam, the utilization efficiency of the light beam is increased, High brightness images can be obtained with a very small amount of light. Further, since high-resolution optical systems are used for the left and right eyes, respectively, wide-angle and high-resolution image display can be performed. In addition, since the deflector, which is an expensive and power-consuming component, is shared by the left and right eyes, the number of components is reduced. Moreover, since the horizontal scanning of the left and right eyes is performed by one deflector, the images can be easily formed on the left and right eyes without performing control for synchronizing the images of the left and right eyes in the horizontal direction. be able to.
Further, since all the deflecting surfaces and the pupil positions of the left and right eyes of the user have a pupil conjugate relationship, the reflecting area of the deflecting surface of the deflector becomes very small, and the deflector itself becomes smaller and lighter. . Therefore, it is possible to provide a video display device that is compact, inexpensive, and labor-saving.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of an image display device of the present invention.

2A and 2B are development views of an optical system according to a first embodiment.

FIG. 3 is a diagram showing a configuration of a second embodiment of an image display device of the present invention.

4A and 4B are development views of an optical system according to a second embodiment.

FIG. 5 is a diagram showing a configuration of a third embodiment of an image display device of the present invention.

FIG. 6 is a diagram showing a configuration of a light source unit of a fourth embodiment of the image display device of the present invention.

[Explanation of symbols]

 1 He-Ne laser (light source) 3 AOM (acousto-optic element) 5 ND filter 7 Galvanometer scanner 8 Beam splitter 11 Polygon mirror 12a, 12b Optical system 14a, 14b Concave mirror 15a, 15b Correction optical system 16a, 16b User's eyeball

Claims (5)

[Claims] 1. A video display device for displaying a video image directly on the retina of a user's eyeball, comprising a light source unit for forming light beams for the left and right eyes, and scanning the light beams in two directions, vertical and horizontal. At least two deflectors, and an optical system that guides a light beam scanned in two directions, vertical and horizontal, to each of the left and right eyes of the user, the first deflecting surface and the second deflecting surface of the deflector. An image display device, characterized in that each of the deflecting surfaces serves as an entrance pupil, and the left and right eyes of a user satisfy a pupil conjugate relationship such that each becomes an exit pupil. 2. One of the deflectors is a rotary polygon mirror, and deflection means for deflecting the light beams for the left and right eyes by different deflecting surfaces of the rotary polygon mirror to simultaneously scan the retinas of the left and right eyes. The video display device according to claim 1, wherein the video display device is configured. 3. The image display according to claim 1, wherein the light source unit includes a laser light source that emits a light beam, and a modulation unit that modulates the light beam according to image information. apparatus. 4. The image display device according to claim 1, further comprising beam splitting means for splitting the light beam emitted from the laser light source into two light beams for the left and right eyes. 5. The light source section includes R, G, B as a light source.
And a dichroic prism that splits the laser light emitted from the white laser into R, G, and B laser light before entering the deflector, and R,
5. A modulation means for modulating G, B laser light according to image information, and a coupling means for recombining the modulated R, G, B laser light, according to claim 1. The video display device according to any one of claims.