JPH11352903A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spectacles display device capable of facilitating lightening and miniaturization and of brightly displaying a large view field of an image. SOLUTION: This image display device has objectives 4 and light scanners 5 comprising movable mirrors made of silicon in parts of spectacles bows 9, and also has cubic beam splitters 1, eyepieces 2 and light deflecting prisms 3 in spectacles front face parts. Accordingly, deflection of a light beam is scanned by the light scanners 5 so that it enters pupils 7 of eyeballs 6 and a focused image is displayed on retinas 8. By adjusting the interval between the two cubic beam splitters 1, the light beam can be guided into each eye so that the image display device is easy to view. Also, by making the focal length of the objectives 4 larger than that of the eyepieces 2, the large image can be displayed.

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, and more particularly to an image display device which can be worn like spectacles and is suitable for miniaturization and weight reduction.

[0002]

2. Description of the Related Art A conventional image display apparatus generally performs horizontal scanning and vertical scanning of a laser beam modulated by a video signal, and forms an image on the retina of an eye by a projection optical system to display an image. I do. Various image display devices having such a configuration have been proposed. This method is characterized in that light emitted from a light source efficiently enters the eyes, thereby realizing an image display device with low power consumption.

For example, Japanese Patent Application Laid-Open No.
The "direct-view image display device" described in JP-A-0088
There has been proposed a direct-view image display apparatus in which a laser beam is scanned in a lateral direction by an acousto-optic deflector, a scanning in a vertical direction is performed by a galvanometric mirror, and an imaging system is formed by two lenses. However, in the first conventional example, since an acousto-optic deflector is used, the configuration of the entire apparatus becomes large.
Not suitable for miniaturization and weight reduction.

As a solution to the problem of the first conventional example,
An image display device incorporated in glasses as shown in FIG. 9 has been proposed. Japanese Patent Laid-Open No. 6-1384 as Conventional Example 2
Japanese Patent Publication No. 99-1992 proposes a method of directly viewing a light emitted from a scanner provided on a vine of a spectacle shown in FIG. 9 by reflecting the light with a lens of the spectacle. I have. The image display device shown in FIG. 9 includes a reflecting mirror 101, a laser beam 102,
03, a fiber relay 104, and a laser light source 105
And a frame 106.

The image display device shown in the above-mentioned prior art example 2 can be incorporated in eyeglasses, but has a disadvantage that a relatively large scanning or deflection angle is required. Also, since multiple reflection by total reflection of light in the waveguide is used,
The need to increase the thickness of the waveguide arises because it is necessary that the light that is ultimately diffracted by the diffractive element and enters the eye and the light that is reflected in the waveguide before that do not overlap.

For example, in order to display an image at a viewing angle of 30 degrees, the diameter of the diffractive optical element 202 is about 1 cm at a position 2 cm away from the eyes. If the final angle of incidence is 60 degrees, the waveguide needs to be about 3 mm thick. For this reason, there is a problem in that the lens portion of the eyeglasses becomes heavy and a burden is imposed on the user.

This drawback is a problem caused by the movement distance between the light source and the retina, as pointed out in Japanese Patent Application Laid-Open No. Hei 6-121257 filed by the same applicant.

FIG. 10 shows a "planar imaging device, a direct retinal scanning display device and a direct retinal scanning display forming method" described in JP-A-6-121256 as a third conventional example in which this disadvantage is improved. Such a spectacle type image display device in which a waveguide and a diffraction element in which light is internally reflected multiple times in a lens portion of spectacles is provided. The image display device shown in FIG. 10 includes an optical waveguide 201, a diffractive optical element 202, an optical wedge 203, and a deflection system 20.
4, a laser / modulator 205, and an electronic circuit 206. Note that reference numeral 207 is an eye, and reference numeral 2
08 indicates the rotation axis of the eye.

[0009] Proceeding of SPIE (No. 2464, pp. 2-13, 1995)
1), an optical system shown in FIG. 11 of Conventional Example 4 has been proposed as a virtual image type image display device. The virtual image display apparatus shown in FIG. 11 includes a mirror 301, a beam splitter 302, and a scanner 303. Note that reference numeral 304 is an eye. This optical system is similar to that used in a conventional liquid crystal display device.

[0010]

However, FIG.
In the virtual image type image display device of the conventional example 4 shown in FIG. 1, since the curved mirror and the beam splitter are used, the size of the device becomes large. Also, since the light beam passes through the beam splitter twice and reaches the eyes, the beam splitter There is a problem that light is reduced and the light is not used efficiently.

Further, since the virtual image type image display device of the conventional example 4 is considered to be displayed for one eye, a display method for both eyes which makes it easier to see and enables a stereoscopic display is not considered. Therefore, there is a problem that there is no means for adjusting the optical path length because the distance between the left and right eyes, which is a problem when displaying images on both eyes, differs from person to person.

The present invention has been made in view of the above points, and can easily display a bright image having a sufficiently large field of view, and is light in weight without greatly increasing the weight of a lens portion. The width of the optical deflector built into the vine is also 1
The present invention proposes an image display device that can be worn like spectacles within a cm, furthermore, it is possible to cope with the difference in the distance between the left and right eyes of a person, and to provide an easy-to-view display and a stereoscopic display for each person. The purpose is to provide.

[0013]

According to a first aspect of the present invention, a light beam emitted from a light source modulated by a video signal is deflected and scanned by a movable mirror, and is projected by a projection optical system. In a virtual image type image display device that displays an image formed on the retina of an eye, a light source provided on a part of a vine of a spectacle, an objective lens forming a part of a movable mirror and a projection optical system, and an An eyepiece that forms another part of the projection optical system provided on the front part,
It is characterized by having optical means for bending the optical path of the projection optical system.

According to a second aspect of the present invention, in the first aspect, the optical means is constituted by a first prism and a second prism or a mirror, and the first prism or the mirror is a lens of spectacles. And a second prism or a mirror is installed in front of the pupil in the front portion of the spectacles.

The third aspect of the present invention provides the first or second aspect.
In the invention described in the above, the image display device includes a position adjusting unit that enables the right and left sides of the second prism or the mirror to be adjusted at positions corresponding to the positions of the respective eyes. When adjusting the position,
The optical distance between the movable mirror and the objective lens is equal to or near the focal length of the objective lens, the optical distance between the eyepiece and the pupil is equal to or near the focal length of the eyepiece, and the objective lens and the eyepiece Are maintained so that the optical distance between them is equal to or close to the sum of the respective focal lengths.

According to a fourth aspect of the present invention, in the third aspect, the focal length of the objective lens is larger than the focal length of the eyepiece.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the mirror is configured to be movable, and a single silicon mirror or one silicon mirror that rotates and vibrates in two axial directions. It is characterized by being constituted by two silicon mirrors which rotate and vibrate in the axial direction.

According to a sixth aspect of the present invention, in the first aspect of the present invention, the light source has one end formed on a silicon substrate having a common oscillation wavelength and the other end having a different oscillation wavelength. It is characterized by being formed of a plurality of optical waveguides coupled to a semiconductor laser.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an image display device according to the present invention will be described in detail with reference to the accompanying drawings. 1 to 8 show an embodiment of the image display device of the present invention.

FIG. 1 is a schematic configuration diagram showing a basic configuration of an image display device according to an embodiment of the present invention. The image display device shown in FIG. 1 includes a cube beam splitter 1 composed of two prisms, two eyepieces 2,
An optical scanner 5 composed of two prisms 3, two objective lenses 4, two light sources and a movable mirror,
It is composed of a pair of eyeglass vines 9. In FIG. 1, the human eyeball 6, pupil 7, and retina 8 are shown in relation to the image display device. FIG. 2 is a detailed view of the path of the light beam in FIG. 1, and mainly shows the path of the beam in the horizontal direction. The focusing of the light beam in the vertical direction is similar to that in the horizontal direction.

An example of the operation of the image display device of the present embodiment constituted by the above components will be described. The light beam emitted from the optical scanner 5 is scanned at high speed in the horizontal and vertical directions. This light beam is condensed by the objective lens 4, reflected by the prism 3, travels along the front surface of the spectacles, and is transmitted as a light beam to the pupil 7 of the eyeball 6 by the eyepiece 2 and the cube beam splitter 1. Incident and focuses on the retina 8.

Therefore, an image is displayed on the retinas 8 of the left and right eyes by modulating the intensity of the light beam with the video signal and performing scanning synchronized with the video signal by the optical scanner 5. Further, by making the focal length of the objective lens 4 longer than the focal length of the eyepiece 2, the deflection angle of the light beam incident on the pupil 7 can be made larger than the scanning angle of the optical scanner 5, and the light beam An image can be displayed with a large field of view even when the scanning angle is small.

As a first embodiment of the present invention, in the image display device shown in FIG.
By setting the focal length of the eyepiece to 2 cm, the scanning angle of the light beam viewed from the eyes is tripled. This corresponds to that when the scanning angle of the light beam emitted by the optical scanner 5 is 10 degrees, a large image having a viewing angle of 30 degrees can be displayed. Further, the optical system is composed of only the objective lens 4 and the prism 3, and by using plastic, a compact and lightweight spectacle-type image display device can be obtained.

FIG. 3 is a diagram showing a configuration example of the optical scanner 5 in the image display device according to the embodiment of the present invention shown in FIG. The image display device shown in FIG. 3 includes a semiconductor laser 14 that emits visible light whose intensity is modulated by a video signal,
A collimator lens 10 for converting the light of the semiconductor laser 14 into a light beam parallel or nearly parallel thereto, and a movable mirror 11 that rotates and vibrates around an axis for scanning the light beam in horizontal and vertical directions. Reference numerals 12 and 13 indicate torsion beams made of silicon that support the movable mirror. Although the other ends of the torsion beams 12 and 13 are not shown, the movable mirror 11 and the torsion beams 12 and 13 are not shown.
And a silicon frame integrally formed.

The diameter of the light beam is selected from about 1 mm to about 5 mm. Then, as shown in FIG. 1, the size of the optical scanner 5 including the movable mirror 11 becomes about 1 cm or less, and can be mounted on the temple 9 of the glasses. Movable mirror 1
By integrating the element 1 and the torsion beams 12 and 13 supporting the same with silicon, the specific gravity of silicon is as small as about 2.33 and the number of defects is small, so that a light and strong mirror can be obtained.

For example, as a silicon movable mirror for scanning in the horizontal direction, a silicon mirror having a surface of 2 mm square and a thickness of 50 microns is supported by a silicon torsion beam of the same thickness, so that the resonance frequency can be adjusted in the horizontal scanning. The frequency can be set to, for example, 16 kHz. The silicon mirror for scanning in the vertical direction has the same structure, and scans the light beam reflected by the mirror for horizontal scanning.
By supporting a silicon mirror having a size of 500 μm and a thickness of 500 μm with a silicon torsion beam having a thickness of 50 μm, the resonance frequency can be set to the vertical scanning frequency, for example, 60H.
can be set to z.

FIG. 4 is a second embodiment showing a configuration example of the optical scanner 5 in the image display apparatus according to the embodiment of the present invention shown in FIG. The optical scanner 5 shown in FIG. 4 is formed integrally with a semiconductor laser 14 that emits visible light whose intensity is modulated by a video signal, a collimator lens 10, a movable mirror 11, torsion beams 12 and 13, a movable mirror 11, and a torsion beam 12. And an intermediate support portion 15 made of silicon. In this case, only one movable mirror 11 is required to rotate and vibrate in two axial directions. Since the movable mirror 11 has a size of about 1 cm or less as in the embodiment shown in FIG. it can.

FIG. 5 shows an embodiment of a light source, which comprises a silicon substrate 18, a semiconductor laser 16, and an optical waveguide 17. The optical waveguide 17 is manufactured by growing and etching glass having different refractive indexes on a silicon substrate 18 and has a function similar to that of a communication optical fiber. For example, the laser beam can be propagated in a single mode by setting the cross-sectional size of the central portion made of high refractive index glass to 10 μm square and the thickness of the peripheral portion made of low refractive index glass to 15 μm. The collimator lens can generate a light beam with high parallelism. In addition, one end of the optical waveguide 17 has a central portion where light propagates, which is united.

For this reason, three semiconductor lasers 16 each emitting light corresponding to the three primary colors of light for performing color display are mounted on the silicon substrate 18 to emit light from the respective semiconductor lasers 16. Light is collected in one optical waveguide 17. By being integrated on the silicon substrate 18, a small and lightweight color light source of 1 cm 3 or less can be realized, and together with a movable mirror for optical scanning,
An optical scanner 5 that can be mounted on the temple 9 of glasses can be realized.

In the present invention, since the cube-type beam splitter 1 partially transmits light, it can display an outside scene and a display image in a superimposed manner, but may use a half mirror. If it is not necessary to see the outside, it can be replaced with a normal prism or mirror.

FIG. 6 shows a second embodiment of the image display apparatus according to the present invention.
In this embodiment, an adjustment device capable of displaying an image in accordance with the distance between the left and right eyes is shown. The image display apparatus according to the second embodiment includes a cube beam splitter 1, an eyepiece 2, a prism 3, an objective lens 4, an optical scanner 5, an eyeglass temple 9, an adjustment dial 19, and a moving table. 20, an adjustment dial 21, and a moving table 22.

The cube-type beam splitter 1 and the eyepiece are mounted on a moving table 20 and the distance from the center can be changed by rotating an adjustment dial 19. Also,
The objective lens 4 and the optical scanner 5 are mounted on a moving table 22, and the adjustment dial 21 is rotated so that the light beam is focused on the retina 8.

7 and 8 are detailed views of the moving mechanism as viewed from the side. FIG. 7 shows a front part of the glasses, and FIG. 8 shows a vine 9 of the glasses. In these figures, the moving mechanism of the present embodiment is a light source in which a cube beam splitter 1, an eyepiece 2, a prism 3, an objective lens 4, a movable mirror 11, a semiconductor laser and a collimating lens are integrated. 23, adjustment dials 19 and 21, and moving tables 20 and 22.

Further, a high-luminance light emitting diode can be used as a light source instead of a semiconductor laser. By reducing the light emitting area, the device can be driven with a small current and a low power consumption image display device can be obtained.

According to the above embodiment, the objective lens 4 provided on the temple 9 of the spectacles and the eyepiece 2 provided on the front surface of the spectacles are used in the projection optical system.
For this reason, even if the deflection angle of the optical scanner 5 is small, the focal length of the eyepiece 2 is made smaller than the focal length of the objective lens 4 close to the optical scanner 5 to form an image with a large visual field on the retina 8. it can. In addition, since the weight of the objective lens 4, the prism 3, or the movable mirror 11 is small, an image display device incorporated in eyeglasses whose weight is reduced as a whole can be obtained. Further, since the optical system can be adjusted with respect to the distance between the left and right eyes, an image display device that is easy to see and that can perform three-dimensional display can be obtained.

The above embodiment is an example of a preferred embodiment of the present invention. However, it is not limited to this.
Various modifications can be made without departing from the spirit of the present invention.

[0037]

As is apparent from the above description, according to the image display apparatus of the present invention, the light source, the movable mirror, and the objective lens forming a part of the projection optical system are provided on a part of the temple of the glasses. An eyepiece as another part of the projection optical system and an optical unit for bending the optical path of the projection optical system are provided on the front part of the glasses. Therefore, the projection optical system and the optical scanner can be mounted on the front frame portion and the vine portion of the spectacles, and an image display device that is small, lightweight, and can display a large screen can be realized. Further, the image can be displayed in accordance with the interval between the left and right eyes required for viewing with both eyes, so that it is easy to see and three-dimensional display is possible.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram of an optical system of a spectacle type display.

FIG. 3 is a configuration diagram of an embodiment of an optical scanner for a spectacle type display.

FIG. 4 is a configuration diagram of an embodiment of an optical scanner for a spectacle type display.

FIG. 5 is a configuration diagram of a light source for color display.

FIG. 6 is a configuration diagram of an embodiment of a glasses-type display.

FIG. 7 is a detailed view of one embodiment of a glasses-type display.

FIG. 8 is a detailed view of one embodiment of a glasses-type display.

FIG. 9 is a configuration diagram of a virtual image display device of Conventional Example 2.

FIG. 10 is a configuration diagram of a virtual image display device of Conventional Example 3.

FIG. 11 is a configuration diagram of a virtual image display device of Conventional Example 4.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cube-type beam splitter 2 Eyepiece 3 Prism 4 Objective lens 5 Optical scanner 6 Eyeball 7 Pupil 8 Retina 9 Glasses vine 10 Collimating lens 11 Movable mirror 12, 13 Twisted beam 14, 16 Semiconductor laser 15 Intermediate support 17 Optical waveguide 18 Silicon substrate 19, 21 Adjustment dial 20, 22 Moving table

Claims (6)

[Claims] 1. A virtual image display device in which a light beam emitted from a light source modulated by a video signal is deflected and scanned by a movable mirror, formed on a retina of an eye by a projection optical system, and displays an image. A light source provided on a part of a temple of glasses, an objective lens forming a part of the movable mirror and the projection optical system, and another part of the projection optical system provided on a front part of the glasses. An image display device comprising: an eyepiece; and optical means for bending an optical path of the projection optical system. 2. The optical device according to claim 1, wherein the optical unit includes a first prism and a second prism.
Wherein the first prism or the mirror is disposed in the lens of the spectacles near a point where the lens and the temple are connected, and the second prism or the mirror is provided. The image display device according to claim 1, wherein the image display device is configured to be installed in front of a pupil in a front portion of the glasses. 3. The image display device further comprises: position adjusting means for adjusting left and right of the second prism or the mirror at positions corresponding to the positions of the respective eyes. When adjusting the position of the prism or the mirror, the optical distance between the movable mirror and the objective lens is equal to or close to the focal length of the objective lens, and the optical distance between the eyepiece and the pupil is The focal length of the eyepiece is equal to or close to the focal length of the eyepiece, and the optical distance between the objective lens and the eyepiece is maintained so as to be equal to or close to the sum of the respective focal lengths. The image display device according to claim 1. 4. The image display device according to claim 3, wherein a focal length of the objective lens is longer than a focal length of the eyepiece. 5. The mirror according to claim 1, wherein the mirror is movable.
One silicon mirror or one that rotates and vibrates in the axial direction
The image display device according to any one of claims 1 to 4, wherein the image display device is configured by two silicon mirrors that rotate and vibrate in the axial direction. 6. The light source according to claim 1, wherein one end formed on a silicon substrate is common, and the other end is formed of a plurality of optical waveguides coupled to semiconductor lasers having different oscillation wavelengths. The image display device according to claim 1.