JPH10319343A - Head-mounted display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized, high resolution and easily colored headmounted display. SOLUTION: When an image signal is supplied from an image supply device to an LCD 3, the LCD 3 emits display light 3a according to the image signal based on a backlight. This display light 3a is transmitted by an FOP(fiber optics plate) 4 to be image formed on an emission end surface 4b as an intermediate image. The intermediate image on the emission end surface 4b becomes divergent light, and is made diffracted light 3b of nearly parallel luminous flux by a hologram combiner 6 having a lens action to be made incident on an eye E of a loader. Outside world light 8a of a scene 8 transmits through the hologram combiner 6 to be made incident on the eye E of the loader as transmission light 8b. Thus, the loader can observe a planar virtual image 9 based on the display light 3a from the LCD 3 in infinite distant overlapped the scene 8 of the outside world.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head mounted display such as a goggle type or a helmet type.
In particular, it relates to a small and high resolution head mounted display.

[0002]

2. Description of the Related Art For example, a head mounted display (HMD) is known as a small-sized image display device which can be mounted on a head to view an image. This HMD
Is arranged in front of an image display unit composed of a display element typified by a liquid crystal display (LCD) and the like, and an image transmission unit composed of a lens and a mirror having aberration correction and magnification functions,
The image display unit and the image transmission unit are fixed to the head by a mounting mechanism such as a belt. When the moving image is displayed on the display element of the image display unit, the displayed moving image is displayed on a large virtual screen in a place that is easy to see by the aberration correction and enlargement functions of the lens and the mirror of the image transmission unit, and Is visually recognized.

[0003] This type of HMD has a high altitude for aircraft use,
From those that display flight information such as speed, those that display movies, video games, and artificial reality for personal theater have been developed and commercialized. Recently, research on a display for a wearable computer has begun.

[0004] Such HMDs include a see-through type in which the outside world can be seen and a closed type in which the outside world cannot be seen. In the case of displaying the virtual reality, the closed type is preferable in some cases, but the see-through type is generally suitable for portable use. The see-through type HMD includes a beam combiner having a see-through function, in addition to the image display unit and the image transmission unit. This beam combiner has a sharp wavelength selectivity for a specific wavelength and can reflect or diffract only that wavelength. Therefore, 100% of the image display light of the specific wavelength and 100% of the image display light excluding that wavelength are displayed. You can see external light superimposed.

FIG. 4 shows a conventional see-through type HMD shown in, for example, US Pat. No. 5,035,474. The HMD 100 has an image display surface 1
01, a CRT for displaying an image, a prism system 103 and a relay lens 104 for forming display light 101a emitted from the image display surface 101 on an intermediate image formation surface 102.
And display light 101 diverged from the intermediate imaging plane 102
and a hologram combiner 105 that makes a a substantially parallel light beam and enters the eye E of the observer. This intermediate imaging plane 102
Is formed of a distorted surface so that an observer can observe the virtual image 107 of a plane. Also, prism system 1
03 and the optical axis of the relay lens 104 and the external scene 10
6 and the angle θ with the horizontal external light 106a emitted from
₁ is set to 58 ° and the hologram combiner 105
Is the angle between the normal axis LX and the optical axis of the relay lens 104, that is, the incident angle θ ₂ of the display light 101a from the relay lens 104 to the hologram combiner 105 is 27.
The angle between the normal axis LX of the hologram combiner 105 and the diffracted light 101b of the display light 101a from the relay lens 104 and the transmitted light 106b of the external light 106a, that is, the reflection angle θ ₃ is set to 30.24 ° Is set to The hologram combiner 105 is installed on a visor (not shown) at an angle of inclination of 59.7 ° as an inclination angle θ ₄ .

In the above HMD 100, the display light 101a of the image displayed on the image display surface 101 converges on the intermediate image forming surface 102 by passing through the prism system 103 and the relay lens 104 to form an intermediate image. . The intermediate image on the intermediate image forming surface 102 becomes divergent light, is converted into a diffracted light 101b of a substantially parallel light beam by the hologram combiner 105 having a lens function, and is incident on the eye E of the observer. External light 106 of the scene 107 passes through the hologram combiner 105 and enters the observer's eye E as transmitted light 106b. Therefore, the observer can observe the virtual image 107 of the plane based on the image display light 101a from the image display surface 101 of the CRT at infinity by superimposing the virtual image 107 on the external scene 106. At this time, the diffracted light 10 of the display light 101a
1b and the amount of transmitted light 106b of the external light 106a does not decrease.

[0007]

However, the conventional HMD
According to 100, since a complicated lens system including the prism system 103 and the relay lens 104 is used to obtain the plane virtual image 107, there is a disadvantage that the display becomes large. To increase the resolution, it is necessary to increase the CRT. However, when the CRT is increased, the prism system 103 and the relay lens 1 are increased.
The complicated lens system consisting of the 04 is also large, and there is a drawback that the improvement in resolution is limited due to space restrictions.
Further, since the hologram combiner 105 is for a single color, there is a disadvantage that it is difficult to handle colors.

Accordingly, an object of the present invention is to provide a small, high-resolution head mounted display. Another object of the present invention is to provide a head mounted display which can be easily colored.

[0009]

In order to achieve the above object, the present invention provides an image display means for emitting image display light, and reduces the image display light from the image display means and emits the light from an emission end face. An optical fiber bundle, and an eye-front optical unit that diffracts or reflects the image display light from the emission end face of the optical fiber bundle and guides the image display light to the eye of the wearer, and allows the wearer to visually recognize a virtual image based on the image display light. The present invention provides a head mounted display characterized by the above.

[0010]

FIG. 1 shows a head mounted display (hereinafter referred to as "HM") according to a first embodiment of the present invention.
D ". (A) is a side view, and FIG.
(b) is a diagram showing the optical system. This HMD 1 is a helmet type HM having a helmet 2 mounted on the head.
D, inside the front part 2a of the helmet 2, a liquid crystal display (LCD) 3 with a backlight as image display means for emitting the display light 3a, and the display light 3a from the LCD 3 is reduced and emitted. A fiber optics plate (FOP) 4 is disposed. These L
The CD3 and the FOP4 are moved by the holder 5 to the front part 2a.
Is held in. A hologram combiner 6 is disposed on the visual axis Ea as an anterior optics means for diffracting the display light 3a from the FOP 4 and guiding the diffracted light 3a to the eye E of the wearer as the diffracted light 3b. This hologram combiner 6
It is attached to the front part 2a by the attachment member 7.

The LCD 3 is, for example, 1200 × 2400
Equipped with 2.88 million pixels of 2.8 inches 40mm x 56
mm. In addition, as the image display means, a reflective LCD, an EL display, a plasma display, or a display using a micro movable mirror manufactured by a micromachine technology can be used. Is preferred in terms of miniaturization.

The FOP 4 is configured to reduce the display light 3a from the LCD 3 to a predetermined reduction ratio, for example, 1/3, and emit the reduced light. That is, the FOP 4 is configured by bundling 7.92 million optical fibers 40 having a shape with a taper ratio of 3: 1 with a thickness of 6 μm on the incident side and 2 μm on the emission side. Further, this FOP4 has an incident end face 4a.
Is in close contact with the LCD 3, and the size of the incident end face 4a is
40 mm × 56 mm, which is the same as the above, and the size of the emission end face 4 b is about 13.2 mm × 18.8 mm. The emission end face 4b is a surface that is distorted so that the wearer can observe a virtual image 9 formed in front of the hologram combiner 6 in a plane, for example, a substantially convex spherical surface.

The hologram combiner 6 includes a transparent or translucent substrate 60 made of glass such as Pyrex glass or soda glass, or plastic, and a main surface of the substrate 60 (for example, a surface on which the display light 3a from the LCD 3 is incident). And a hologram film 61 formed on an opposite surface 60a. The hologram film 61 is formed by applying a hologram photosensitive material to the main surface 60a of the substrate 60 and using a method described later. This hologram photosensitive material includes, for example, photopolymer, photoresist, photochromic, photodichromic, silver salt emulsion, dichromated gelatin, dichromated gelatin, plastic, ferroelectric, magneto-optical material, electro-optical material, amorphous A high quality semiconductor, a photorefractive material or the like is used. Note that a protective film for protecting the hologram film 61 may be provided on the surface. This protective film is made of amorphous polyolefin, polycarbonate (PC), polymethyl methacrylate (PMM
A), perfluoroalkoxy polyethylene (PFA)
Are used. Further, in the present embodiment, hologram combiner 6 has a concave shape toward eye E of the wearer, but may have a flat shape.

The hologram film 61 forms a small asymmetric optical system. That is, the hologram film 61 includes a first optical axis 61a coinciding with the visual axis Ea and a first optical axis 61a.
In contrast, for example, the second optical axis 61b having an angle θ ₁ of 58 °
have. The angle between the normal axis LX of the hologram combiner 6 and the optical axes of the LCD 3 and the FOP 4, that is, the incident angle θ ₂ of the display light 3a from the FOP 4 to the hologram combiner 6 is set to, for example, 27.76 °. The angle formed between the normal axis LX of the hologram combiner 6 and the diffracted light 3b of the display light 3a from the FOP 4 and the transmitted light 8b of the external light 8a, that is, the reflection angle θ ₃ is, for example, 3
It is set to 0.24 °. The hologram combiner 6 is attached to the helmet 2 at an inclination angle θ ₄ of 59.7 °.

FIG. 2 shows a hologram film forming apparatus for forming the hologram film 61. This hologram film manufacturing apparatus 1
Reference numeral 0 includes a He-Ne laser 11, first, second and third mirrors 12A, 12B and 12C, a half mirror 13, first and second magnifying lenses 14A and 14B, and a collimator lens 15.

First, a hologram photosensitive material, for example, a photopolymer 6a is spin-coated on the main surface 60a of the substrate 60. At this time, the photopolymer 6a having a uniform film thickness is formed by controlling the rotation speed and the like.
Next, the substrate 60 having the photopolymer 6a formed thereon is
It is arranged at a predetermined position shown in FIG. Hologram film production equipment 1
When the laser beam 11a is emitted from the He-Ne laser 11 of the first mirror, the laser beam 11a
After being bent at 2A, the beam is split by the half mirror 13 into two beams 13a and 13b. After the beam 13a transmitted through the half mirror 13 is bent by the second mirror 12B and converted into a divergent wave by the first magnifying lens 14A,
The light is converted into a plane wave by the collimator lens 15. The other beam 13b reflected by the half mirror 13 is
After being bent by the third mirror 12C, it is converted into a divergent wave by the second magnifying lens 14B. Its divergent wave, angle theta ₁ between the optical axis and the Z-axis of the divergent wave is incident from the back side of the photopolymer 6a at the same angle as the angle theta ₁ shown in FIG. 1 (b). Beam 1 incident from the front side of photopolymer 6a
3a and the beam 13b incident from the back side of the photopolymer 6a form interference fringes on the photopolymer 6a.
The hologram is recorded on the interference fringes formed on the photopolymer 6a through a development process, and the hologram film 61 is completed. Although the method of manufacturing the hologram film 61 using a plane wave and a divergent wave has been described, the hologram film 61 can also be manufactured using a convergent wave and a divergent wave.

Next, the operation of the HMD 1 according to the first embodiment will be described. When an image signal is supplied from an image supply device (not shown) to the LCD 3, the LCD 3 emits display light 3a corresponding to the image signal based on the backlight.
The display light 3a is transmitted by the FOP 4, and forms an intermediate image on the emission end face 4b. The intermediate image on the exit end face 4b becomes divergent light, is converted into a diffracted light 3b of a substantially parallel light flux by the hologram combiner 6 having a lens function, and is incident on the eye E of the wearer. External light 8a of the scene 8 passes through the hologram combiner 6 and is incident on the eye E of the wearer as transmitted light 8b. Therefore, the wearer can observe the virtual image 9 of the plane based on the display light 3a from the LCD 3 at infinity, superimposed on the scene 8 of the outside world.

Next, H according to the first embodiment described above is used.
The effect of MD1 will be described. (A) Since the exit end face 4b of the FOP 4 is an intermediate image forming surface, it is not necessary to form an intermediate image forming surface using a lens system.
Further, since the hologram combiner 6 can be built in, the HMD 1 can be downsized. (B) Since the display light 3a from the LCD 3 is reduced by the FOP 4, the LCD 3 having a large number of pixels can be used, so that a high-resolution virtual image 9 can be displayed. (C) Since the emission end face 4b of the FOP 4 has a shape for correcting the aberration of the virtual image 9, the plane virtual image 9 can be visually recognized. (D) When this HMD1 is applied to an aircraft HMD,
The external world and flight information can be viewed at the same time, and when applied to an HMD for automobiles, the external world and traffic information can be viewed at the same time, providing excellent readability during flight or running. Can be.

FIGS. 3A and 3B show an HMD according to a second embodiment of the present invention. FIG. 3A is a side view thereof, and FIG. 3B is a view showing an optical system thereof. The HMD 1 is a goggle type HMD provided with a goggle 21 attached to the head H by a headband 20.
1a, a backlit LCD 3 as image display means for emitting display light orthogonal to the visual axis Ea;
FOP4 for reducing and emitting display light 3a from LCD3
And are arranged. These LCD3 and FOP4
Is held on the upper portion 21a by the holder 5. Further, on the visual axis Ea, a concave half mirror 62 serving as an anterior optical means having an enlarging function, which is disposed with the concave surface facing the wearer's eye E, and an angle of 45 degrees with respect to the visual axis Ea of the wearer And a half mirror 63 as an anterior optics means for reflecting the display light 3a from the FOP 4 to the concave half mirror 62 and further guiding the display light reflected by the concave half mirror 62 to the eye E of the wearer. ing. The concave half mirror 62 has an opening 21 b in front of the goggles 21.
The half mirror 63 is provided inside the front part 21b.

The LCD 3 is smaller in size than the first embodiment, for example, 6 to accommodate in the goggles 21.
Equipped with 720,000 pixels of 00 × 1200, 1.4 inch 2
It has a size of 0 mm x 28 mm.

The FOP 4 has a shape with a thickness of 6 μm on the incident side and a thickness of 2 μm on the exit side and a taper ratio of 3: 1.
9.98 million optical fibers 40 are bundled, the incident end face 4a is in close contact with the LCD 3, the size of the incident end face 4a is the same as that of the LCD 3, 20 mm × 28 mm, and the exit end face 4b
Has a size of about 6.6 mm × 9.4 mm. In the FOP 4, similarly to the first embodiment, the emission end face 4 b is a surface that is distorted so that the wearer can observe the flat virtual image 9.

Next, the operation of the HMD 1 according to the second embodiment will be described. When an image signal is supplied from an image supply device (not shown) to the LCD 3, the LCD 3 emits display light 3a corresponding to the image signal based on the backlight.
The display light 3a is transmitted by the FOP 4, and forms an intermediate image on the emission end face 4b. The intermediate image on the exit end face 4b is divergent and is incident on the half mirror 63, and the reflected light 3c is reflected by the half mirror 63 and is incident on the concave half mirror 62 having an enlarging function, and a part thereof is reflected. Then, it is converged light 3d, passes through the half mirror 63, and enters the eye E of the wearer as transmitted light 3e. External light 8 of scene 8
a is a concave half mirror 62a and a half mirror 63
And enters the eye E of the wearer as transmitted light 8b.
Therefore, the observer can view the display light 3a from the LCD 3 at infinity.
The virtual image 9 of the plane enlarged based on the image can be superimposed on the external scene 8 and observed.

Next, H according to the third embodiment of the present invention will be described.
The MD will be described. This third embodiment is shown in FIG.
Is a colorized version of the HMD 1 according to the first embodiment shown in FIG. 1, and the other configuration is the same as that of the first embodiment. In the third embodiment, red (R), green (G),
A color L that emits display light composed of blue (B) three primary colors
A hologram combiner 6 corresponding to the three primary colors of R, G and B is used by using a CD. To manufacture the hologram combiner 6 corresponding to the three primary colors of R, G, and B, a helium-neon laser (632.8 nm) for R is used in the hologram film manufacturing apparatus 10 shown in FIG. ), A hologram is recorded using a YAG-SHG laser (532 nm) for G, and an argon laser (488) is used for B.
The hologram is recorded using nm). According to the third embodiment, it is possible to display a color virtual image while being small.

The present invention is not limited to the above-described embodiment, but can take various forms. For example, in the configuration shown in FIG.
The half mirror 63 may be arranged at an angle of 45 degrees with respect to a. In the above embodiment, the see-through type has been described, but a closed type may be used. In this case, a light-shielding sheet may be attached to the outer surface of the substrate (the surface opposite to the surface on which the display light from the LCD is incident) so that external light does not enter the eyes of the wearer. Other members may cover the entire substrate. Further, in the first embodiment, the hologram film is formed on the outer surface of the substrate, but may be formed on the inner surface of the substrate.

[0025]

As described above, according to the present invention, by using an optical fiber bundle, a desired intermediate imaging plane can be obtained without using a lens system, so that downsizing can be achieved. Further, since the image display light from the image display means is reduced by the optical fiber bundle, the image display means having a large number of pixels can be used, so that a high-resolution virtual image can be displayed. As a result, colorization becomes easy.

[Brief description of the drawings]

1A and 1B show an HMD according to a first embodiment of the present invention, wherein FIG. 1A is a side view thereof, and FIG. 1B is a diagram showing an optical system thereof.

FIG. 2 is a schematic configuration diagram of a hologram film manufacturing apparatus according to the first embodiment.

3A and 3B show an HMD according to a second embodiment of the present invention, wherein FIG. 3A is a side view and FIG. 3B is a view showing an optical system thereof.

FIG. 4 is a configuration diagram of a conventional HMD.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Head mounted display (HMD) 2 Helmet 2 2a Front part 3 Liquid crystal display (LCD) 3a Display light 3b Diffracted light 3c Reflected light 3d Focused light 3e Transmitted light 4 Fiber optics plate (FOP) 4a Incident end face 4b Exit end face 5 Holder Reference Signs List 6 hologram combiner 7 mounting member 8 sight 8a external light 8b transmitted light 9 virtual image 10 hologram film forming apparatus 11 He-Ne laser 12A, 12B, 12C mirror 13 half mirror 14A, 14B magnifying lens 15 collimator lens 20 headband 21 goggle 21a upper part 21b Opening 21b Front 40 Optical fiber 60 Substrate 60a Main surface 61 Hologram film 61a First optical axis 61b Second optical axis 62 Concave half mirror 63 Half mirror E Eye H Head

Claims (12)

[Claims] An image display means for emitting image display light; an optical fiber bundle for reducing the image display light from the image display means and emitting the light from an emission end face; and the image of the optical fiber bundle from the emission end face. A head mounted display, comprising: an anterior optics means for diffracting or reflecting the display light to guide the wearer's eyes to the wearer to visually recognize a virtual image based on the image display light. 2. The head mounted display according to claim 1, wherein said anterior optics means guides external light to said wearer's eye. 3. The apparatus according to claim 1, wherein said anterior optics means includes a substrate made of transparent or translucent glass, plastic, or the like, and a hologram film formed on a main surface of said substrate.
A head mounted display as described. 4. The anterior optics means is a mirror disposed at an angle of 45 degrees with respect to the visual axis of the wearer, and reflecting the image display light from the optical fiber bundle to guide the light to the wearer's eyes. The head-mounted display according to claim 1 having a certain configuration. 5. The anterior optics means includes a concave mirror arranged with a concave surface facing the wearer's eye, and a 45-degree angle with respect to the wearer's visual axis. The head mounted display according to claim 4, further comprising a mirror configured to reflect the image display light to the concave mirror and guide the image display light reflected by the concave mirror to the wearer's eyes. 6. The head mounted display according to claim 1, wherein said optical fiber bundle has a configuration in which said exit end face has a predetermined shape for correcting aberration of said virtual image. 7. The head mounted display according to claim 1, wherein said optical fiber bundle has a structure in which an incident end face is in close contact with a display screen of said image display means. 8. The head mounted display according to claim 1, wherein said optical fiber bundle has a configuration in which the number of optical fibers constituting said optical fiber bundle is larger than the number of pixels of said image display means. 9. The head mounted display according to claim 1, wherein said image display means emits the color image display light. 10. The head according to claim 3, wherein said image display means emits the color image display light, and said hologram film has a hologram recorded thereon corresponding to said color image display light. Mounted display. 11. The head mounted display according to claim 1, wherein said image display means comprises a liquid crystal display, an EL display, a plasma display, or a display using a micro movable mirror manufactured by micro machine technology. 12. The head mounted display according to claim 1, wherein said image display means, said optical fiber bundle, and said anterior optics means are mounted on goggles or a helmet.