JPH07175009A - Visual display device - Google Patents

Abstract

PURPOSE:To enable an observer to observe a bright image flat up to the periphery by using an eyepiece optical system having first and second translucent reflection surfaces having the centers of curvature in approximately the same positions. CONSTITUTION:The eyepiece optical system has the first and second translucent reflection surfaces 2, 3 having the respective centers of curvature in approximately the same positions. The first and second translucent reflection surfaces 2, 3 are so constituted that the luminous flux transmitted through the first translucent reflection surface 2 is reflected by the second translucent reflection surface 3 and the reflected luminous flux reflected by the second translucent reflection surface 3 transmits the second translucent reflection surface 3. This eyepiece optical system has at least the two translucent reflection surfaces 2, 3 which are arranged with the centers of the curvature near the pupil position 1 of the observer's eyeballs and of which the concave faces are directed to the pupil side. The translucent reflection surfaces 2, 3 are respectively so arranged as to make at least one time of transmission of rays and at least one time of reflection of the rays.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual display device,
In particular, it relates to a head- or face-mounted visual display device that can be held on the head or face of an observer.

[0002]

2. Description of the Related Art For a head-mounted visual display device, it is important to reduce the size and weight of the entire device so as not to impair its wearability. The factor that determines the size of the entire apparatus is the layout of the optical system. FIG. 22 shows an optical system of a conventional head-mounted visual display device (Japanese Patent Laid-Open No. 3-10170).
No. 9). This visual display device transmits a display image of a two-dimensional image display element as an aerial image by a relay optical system including a positive lens, and magnifies the aerial image by an eyepiece optical system including a concave reflecting mirror to observer's eyeball. It is what is projected inside. Further, conventionally, in order to reduce the size of the entire apparatus, a direct-view type in which a two-dimensional image display element is magnified by a convex lens and directly observed is also known. In these layouts, the amount of device protrusion from the observer's face becomes large. Furthermore, in order to have a wide observation angle of view, a large positive lens diameter and a large 2
It is necessary to use a three-dimensional image display device, and the device becomes larger and heavier at the same time.

In order to enable observation for a long time without feeling fatigue and to easily attach / detach, it is desirable to arrange a short and light eyepiece optical system in front of the eyes of the observer. By doing so, the two-dimensional image display element, the illumination optical system, and the like can be arranged with a small amount of protrusion to the front of the observer's head, and the amount of protrusion of the device can be reduced and the weight can be reduced.

Next, it is necessary to secure a large angle of view in order to enhance the sense of reality during image observation. In particular, the stereoscopic effect of the presented image is determined by the presentation angle of view (Journal of the Television Society of Japan, Vol.45, No.12, pp.1589-1596).
(1991)). The next important issue is how to realize an optical system that provides a wide angle of view and high resolution. In order to give the observer a three-dimensional effect and a feeling of force, 40 in the horizontal direction.
It is known that it is necessary to secure a presentation angle of view of ° (± 20 °) or more, and at the same time, the effect is saturated near 120 ° (± 60 °). That is, it is desirable that the observation angle of view is as close to 120 ° as possible at 40 ° or more.

By the way, as shown in FIG. 23, US Reissued Patent No. 27356 is an eyepiece optical system for projecting an object plane 62 to a distance by a semitransparent concave mirror 6 and a semitransparent plane mirror 16. The arrangement is such that the optical path from the image display element 62 to the observer's eyeball position 66 can be repeatedly reflected and shortened, and the amount of projection of the visual display device forward of the observer's head can be shortened. is there.

However, the concave mirror 6 is, by its nature,
When a flat two-dimensional image display element is placed at the focal position of the concave mirror 6 in order to generate a strong concave image field curvature along the surface of the concave mirror 6, the observation image plane is curved and extends to the periphery of the visual field. It is not possible to obtain a clear observation image.
Therefore, it is necessary to bend the object plane 62 to correct this field curvature.

However, in general, it is relatively easy to form a display surface with a curved surface having a curvature when a display element of a CRT is used, but the weight of the CRT itself is LC.
It becomes heavier than a liquid crystal display element such as D. Also,
It is necessary to use a large two-dimensional image display device having a high screen density in order to provide an image with a wide angle of view and good resolution to the periphery. Although it is desirable to use it, it is very difficult to bend the display surface of a flat panel image display device such as an LCD due to its structure.

Therefore, even with such an eyepiece optical system, it is possible to clearly observe the periphery of the visual field, present an observation image to the observer at a wide observation angle, and realize a small and lightweight visual display device. It was difficult.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art, and its object is to provide a wide angle of view of 30 ° (± 15 °) or more. It is an object of the present invention to provide a compact and lightweight visual display device having a high resolution and a large exit pupil diameter, which allows a flat and clear observation image to the periphery to be observed using a planar two-dimensional image display element.

[0010]

The visual display device of the present invention has been made in order to solve such a problem, and is an image display means for displaying an image and an image formed by the image display means. In the visual display device, which comprises an eyepiece optical system that projects the light beam and guides it to the observer's eyeball, the eyepiece optical system has a first half having a center of curvature substantially on the optical axis and having a concave surface in the direction of the center of curvature. A transflective surface, and a second semi-transmissive reflective surface having a center of curvature substantially at the same position as the center of curvature
And a semi-transmissive reflecting surface.

In this case, the eyepiece optical system has first and second semi-transmissive reflection surfaces having respective centers of curvature at substantially the same position, and the light flux transmitted through the first semi-transmissive reflection surface is The reflected light flux reflected by the second semi-transmissive reflective surface and reflected by the second semi-transmissive reflective surface passes through the second semi-transmissive reflective surface after being reflected by the first semi-transmissive reflective surface. Thus, it is desirable to configure the first and second semi-transmissive reflective surfaces.

The eyepiece optical system has a center of curvature near the pupil position of the observer's eye and has at least two semi-transmissive reflective surfaces with concave surfaces facing the pupil side, and each of these semi-transmissive reflective surfaces. Are preferably arranged to transmit the light rays at least once and to reflect the light rays at least once.

Further, it is desirable that the refractive power of the eyepiece optical system with respect to a light ray that passes through each semi-transmissive reflecting surface of the eyepiece optical system without being reflected once is substantially zero.

Further, in order to block a light beam which is transmitted without being reflected by the two semi-transmissive reflecting surfaces even once, it is desirable that a blocking means composed of a polarization optical element is arranged.

Further, it is desirable to have a positioning means for positioning the image display element and the eyepiece optical system with respect to the observer's head.

Further, it is desirable to have a supporting means for supporting the image display element and the eyepiece optical system with respect to the observer's head so that they can be mounted on the observer's head.

Furthermore, it is also desirable to have a supporting means for supporting at least two sets of such visual display devices at regular intervals.

When the radii of curvature of the first and second semi-transmissive reflecting surfaces are R ₁ and R ₂ , 0.5 <| R ₁ / R ₂ | <1.8 (2) It is preferable to satisfy the conditions.

The radius of curvature of the first semi-transmissive reflective surface is R ₁ , the distance from the pupil to the first semi-transmissive reflective surface near this pupil is D ₁ , the first semi-transmissive reflective surface and the second semi-transmissive reflective surface. It is preferable that the condition of 0.4 <| (D ₁ + D ₂ ) / R ₂ | <1.7 (3) is satisfied, where D ₂ is the interplanar distance between and.

Further, the radius of curvature of the first semi-transmissive reflective surface closer to the pupil is R ₁ , the radius of curvature of the second semi-transmissive reflective surface further away from the pupil is R ₂ , and the first semi-transmissive reflective surface and the second semi-transmissive reflective surface. When the surface distance from the semi-transmissive reflective surface is D ₂ , it is preferable to satisfy the following condition: 1 <(| R ₁ | + D ₂ ) / | R ₂ | <1.8 (4) .

When the radius of curvature of the first semi-transmissive reflective surface closer to the pupil is R ₁ and the distance from the pupil to the first semi-transmissive reflective surface closer to the pupil is D ₁ , | D ₁ / R It is preferable that the condition ₁ | <1.5 (5) is satisfied.

[0022]

The reason and operation of adopting such a structure in the present invention will be described below. The present invention has been made to solve the above-mentioned problems, and as an eyepiece optical system that projects an image displayed on an image display unit and guides it to an observer's eyeball, a center of curvature is approximately on the optical axis. An eyepiece having a first semi-transmissive reflective surface having a concave surface in the direction of the center of curvature and a second semi-transmissive reflective surface having a center of curvature substantially at the same position as the center of curvature of the first semi-transmissive reflective surface. It is characterized by using an optical system.

In the following, for convenience of explanation, the eyepiece optical system of the present invention will be described as an image-forming optical system by the reverse tracing of light rays from the exit pupil position of the eyepiece optical system toward the object plane. The optical system of (1) is a system in which light rays travel in the opposite direction with the image plane as the object point. The optical system of the present invention in which the centers of curvature are arranged at substantially the same position is generally called a concentric optical system. FIG. 1 is a diagram for explaining the basic configuration of a concentric optical system according to the present invention and the reason why aberration is small. In FIG. 1, the pupil position is 1, the first semi-transmissive reflection surface is 2, The two semi-transmissive reflective surfaces are 3, and the image surface is 4. FIG. 1 is an optical path diagram when the center of curvature of the first surface 2 and the center of curvature of the second surface 3 completely coincide with the pupil position 1. It can be seen from this optical path diagram that the on-axis rays and off-axis rays rotate about the pupil position 1 because the centers of curvature of the pupil plane 1 and the first plane 2 and the center of curvature of the second plane 3 coincide. It is symmetrical. This means that astigmatism and coma which are off-axis aberrations do not occur. In addition, since all surfaces having refractive power are reflecting surfaces, chromatic aberration does not occur in principle. When the F number is 2 or less, the occurrence of spherical aberration can be almost ignored. However, the image plane formed by the second surface 3 becomes a spherical surface centered on the pupil position 1 and only field curvature occurs.

Further, the concentric optical system of the present invention is similar to that of the US Reissued Patent No. 27356 shown in FIG.
Since the light rays are repeatedly reflected between the two semi-transmissive reflective surfaces 2 and 3, it is possible to shorten the mechanical length from the position of the entrance pupil 1 to the image plane 4 by using a lens system composed of one convex lens or the like. Therefore, by using this as an eyepiece optical system, it is possible to configure a small visual display device with a small amount of device protrusion from the observer's face.

The present invention succeeds in favorably correcting the field curvature of the concentric optical system in which aberration is extremely small as described above. The field curvature correcting means according to the present invention will be described below.

In US Pat. No. 27,356 of FIG. 23, in order to correct the field curvature generated by the concave mirror 6, the image surface (object surface in the present invention) 62 is curved and the curvature of field is corrected. Is going. However, in general, a curved two-dimensional image display element is easy to configure with a CRT, but it is very difficult to form a curved display surface on a liquid crystal display element such as an LCD.

Therefore, in the present invention, as shown in FIG. 1, the convex mirror 2 is used to correct the aberration of the field curvature generated by the concave mirror 3.

That is, Petzval sum PS, which is generally well-known as the amount of field curvature, is expressed by the following equation. PS = Σ (1 / n · f) (1) where n is the refractive index and f is the focal length of the surface. In the case of US Reissue Patent No. 27356, since the convex mirror 2 of the present invention is replaced with the plane mirror 16, the concave mirror 6 is used.
Since the focal length of the plane mirror 16 is ∞, the Petzval sum generated when the light beam is reflected at is not corrected at all. Therefore, in the present invention, the plane mirror 16 is used as the convex mirror 2, and the Petzval sum generated in the concave mirror 3 can be corrected by the convex mirror 2.

The two-dimensional image display device such as LCD is
When viewed obliquely, the contrast is lowered and the visual characteristics are poor. Therefore, it is desirable to use a light beam projected vertically to the two-dimensional image display element as a light beam projected on the observer's eyeball. That is, the pupil plane 1 should not be located around the concave mirror 3 or the convex mirror 2 or on the image 4 side of the concave mirror 3 so that the off-axis chief ray exiting the eyepiece optical system becomes parallel to the optical axis. That is, it is an important means to arrange the pupil plane 1 in the direction in which the concave mirror 3 has the center of curvature.

Further, in order to perform good aberration correction, it is preferable that the following conditional expressions be satisfied. The following conditional expressions correspond to each aberration, and the angle of view and F
Each conditional expression is independent and has no correlation depending on actual use such as number. It is also necessary to satisfy all the conditional expressions depending on the usage conditions.

First, the relationship between the first surface 2 and the second surface 3 will be described. As described above, the correction of the Petzval sum is particularly important for achieving good aberration correction, and the present invention satisfies the following conditions for the correction of the Petzval sum. This is very important. 0.5 <| R ₁ / R ₂ | <1.8 (2) where R ₁ is the radius of curvature of the first surface 2 and R ₂ is the radius of curvature of the second surface 3.

This conditional expression (2) defines the power distribution of the positive second surface 3 and the negative first surface 2, and when the lower limit of 0.5 is exceeded, the first surface 2 and the second surface The correction balance of the Petzval sum, which is corrected by the surface 3, is lost, and a large negative Petzval sum occurs. Further, when the upper limit of 1.8 is exceeded, the Petzval sum is positively large, and it becomes impossible to correct it in other aspects.

Further, in recent years, when it is necessary to cope with high-definition video represented by high-definition TV and the like, better Petzval sum correction is necessary, and it is more important to satisfy the following conditions. Is. 0.7 <| R ₁ / R ₂ | <1.7 (6) Next, the semi-transmissive reflective surface of the second surface 3 will be described. The distance from the pupil plane 1 to the first plane 2 is D ₁ , the first plane 2 and the second plane 3 are
It is desirable to satisfy the condition of 0.4 <| (D ₁ + D ₂ ) / R ₂ | <1.7 (3), where D ₂ is the interplanar spacing.

If the lower limit of 0.4 to condition (3) is not reached, the angle of inclination of the chief ray of emergent light passing through the second surface 3 becomes large,
Astigmatism and coma are greatly negatively generated. Further, when the upper limit of 1.7 is exceeded, negative astigmatism and coma aberration are reduced. This cancels out positive astigmatism and coma that occur when the light passes through the first surface 2, so that positive astigmatism and coma are increased in the entire lens system.

It is also important that the second surface 3 is concentric in the present invention. The radius of curvature of the first surface 2 is R
₁ , the radius of curvature of the second surface 3 is R ₂ , and the surface distance between the first surface 2 and the second surface 3 is D ₂ , 1 <| (| R ₁ | + D ₂ ) / R ₂ | <1.8 (4) It is important to satisfy the following condition.

The above condition (4) is a condition that allows the entire system to correct the occurrence of coma and astigmatism occurring on the second surface 3. When the lower limit of 1 is exceeded, a perfect concentric optical system is obtained. , It becomes impossible to correct Petzval sum, and a large field curvature occurs. If the upper limit of 1.8 is exceeded,
The incident angle of the principal ray incident on the second surface 3 becomes large, and the positive coma becomes large. In either case, it becomes impossible to form a clear image even in the periphery.

Preferably, when the distance from the pupil surface 1 to the first surface 2 is D ₁ and the radius of curvature of the first surface 2 is R ₁ , | D ₁ / R ₁ | <1.5・ It is desirable to satisfy the condition (5).

When the upper limit of 1.5 to condition (5) is exceeded, the incident height of the chief ray incident on the first surface 2 becomes large,
The occurrence of positive coma and astigmatism becomes large,
It becomes impossible to form a clear image to the periphery.

Next, the surface spacing will be described. When the surface distance between the pupil plane 1 and the first surface 2 is D ₁ and the focal length of the entire system is F, it is important to satisfy the following condition: D ₁ /F<1.6 (7) is there.

The conditional expression (7) is a condition for reducing the coma aberration generated on the first surface 2. Upper limit of 1.6
When it exceeds, the occurrence of coma aberration on the first surface 2 becomes large and it becomes impossible to correct it on other surfaces. Also,
When the optical system of the present invention is used as an eyepiece optical system, it is important to satisfy the condition 0.5 <D ₁ / F (8).

In the case of the eyepiece optical system, the above conditional expression (8) is the eyepoint of the eyepiece lens, and when the lower limit of 0.5 is exceeded, the observer's pupil position and the exit pupil position of the eyepiece optical system 1
However, it becomes impossible to observe the entire visual field.

When the surface distance between the first surface 2 and the second surface 3 is D ₂ , it is important to satisfy the condition of 0.2 <D ₂ /F<0.7 (9). . This condition is the first
It is necessary to balance the Petzval sum generation on the surface 2 and the Petzval sum generation on the second surface 3. When the upper limit of 0.7 or the lower limit of 0.2 is exceeded, the balance of the above-mentioned aberrations generated on the first surface 2 and the second surface 3 is lost, and a large amount of Petzval sum aberrations that are almost corrected are generated. Resulting in.

In order to cut the flare light which is transmitted through the first surface 2 and the second surface 3 without being reflected once and reaches the image plane 4, a polarizing optical element using polarized light is arranged. It becomes important to do. For example, by arranging a first polarizing plate and a quarter-wave plate on the pupil 1 side of the first surface 2 to make incident light circularly polarized, and between the semi-transmissive reflective surfaces of the first surface 2 and the second surface 3, Another quarter-wave plate is arranged, and the second polarizing plate in which the first polarizing plate and the polarization plane of para-Nicol are arranged after the semi-transmissive reflecting surface of the second surface 3 is arranged. When such a polarizing optical element is arranged,
The regular light rays reflected once by the first surface 2 and the second surface 3 respectively pass through the quarter-wave plate between the first surface 2 and the second surface 3 three times, and thus the regular light rays. Will pass through the quarter-wave plate a total of four times. Therefore, the plane of polarization of the light that has passed through the first polarizing plate does not rotate and passes through the second polarizing plate arranged in the paranicols. However, the light rays that have passed through the semi-transmissive reflective surface of the first surface 2 pass through the quarter-wave plate only twice in total, and the polarization surface is rotated 90 ° and cut by the second polarizing plate. It

As described above, it is possible to cut flare light by using the polarization optical element. Also,
It is possible to arrange polarization optical elements other than those described above,
Only one example is given here.

In the visual display device according to the present invention, a pair of the concentric optical system and the two-dimensional image display element is prepared on the left and right sides, and they are supported apart from each other by an eye-radiation distance to support both eyes. It can be configured as a stationary type or a portable type such as a head mounted visual display device that can be observed at. FIG. 2 is a perspective view (a) and an enlarged view (b) of an eyepiece S of an example in which such a visual display device is installed in a game machine M as a stationary type. Protrusions 7, 7 for positioning the head H from both sides with respect to the eyepiece S when abutting against the portion S and looking into the visual display device are provided on both sides of the eyepiece S as positioning means. FIG. 3 is a perspective view of an example in which such a visual display device is configured as a goggle-type head-mounted visual display device G. In order to support the visual display device G on the observer's head, The headband 8 is used. As described above, the visual display device of the present invention is further provided with the means for determining the relative position with respect to the eyeball of the observer, so that it becomes easier to observe.
This is because there is a limit even if the exit pupil position of the optical system on the device side is wide, and it cannot be observed from any direction like a TV screen.

[0046]

The first to ninth embodiments of the optical system of the visual display device of the present invention will be described below with reference to the drawings. First Embodiment A first embodiment will be described with reference to FIG. In the figure, 1 is the stop position, 2 is the first semi-transmissive reflective surface, 3 is the second semi-transmissive reflective surface, and 4 is the image plane. It should be noted that, in reality, LC on the image plane 4
A two-dimensional image display element such as D is arranged, and the light rays travel in the opposite direction (the same applies to the following examples). This example
Two meniscus lenses L1 and L2 are used, the convex surface of the meniscus lens L1 is the first semi-transmissive reflective surface 2, and the convex surface of the meniscus lens L2 is the second semi-transmissive reflective surface 3. Numerical examples are as shown below. However, nd
Is the refractive index of the lens at the d-line, and νd is the Abbe number (the same applies hereinafter). In this embodiment, the angle of view is 45 ° and the focal length is F.
= 10 mm, F number is 3.5.

Surface number Radius of curvature Surface spacing nd νd 1 Pupil position 1 9.158 2 -5.5382 1.624 1.5163 64.1 3 -7.7395 0.071 4 -7.8437 2.777 1.5163 64.1 5 -9.1995 (Reflecting surface 3) -2.777 1.5163 64.1 6 -7.8437 -0.071 7 -7.7395 (Reflecting surface 2) 0.071 8 -7.8437 2.777 1.5163 64.1 9 -9.1995 5.141 10 Image plane 4 FIG. A lateral aberration diagram is shown in (b).

Second Embodiment A second embodiment will be described with reference to FIG. In the figure, 1 is a pupil position, 2 is a first semi-transmissive reflective surface, 3 is a second semi-transmissive reflective surface, and 4 is an image plane. In this embodiment, one meniscus lens L is used, its concave surface is the first semi-transmissive reflective surface 2, and its convex surface is the second semi-transmissive reflective surface 3. Numerical examples are as shown below. The angle of view of this embodiment is 60.
In °, the focal length is F = 10 mm and the F number is 1.5.

Surface number Radius of curvature Surface spacing nd νd 1 Pupil position 1 10.130 2 -13.6165 5.239 1.5163 64.1 3 -14.6357 (Reflecting surface 3) -5.239 1.5163 64.1 4 -13.6165 (Reflecting surface 2) 5.239 1.5163 64.1 5 -14.6357 1.216 6 Image plane 4 FIG. 14 shows an aberration diagram similar to that of FIG. 13 of the present embodiment.

In the present embodiment, the focal length for a light ray that is transmitted without being reflected by the semi-transmissive reflecting surfaces 2 and 3 is 500 m.
m, and if the focal length is F and the refractive power is φ, then φ = 1 / F 2, and in this case φ = 0.002. In this case, by removing the image display element 4 from the front surface of the eyepiece optical system, it is possible to observe an image of the outside world through the eyepiece optical system. That is, it is possible to observe peripheral images other than the observed image without removing the device main body one by one.

More preferably, it is important to satisfy the conditional expression that the refracting power φ for a light beam that passes through the eyepiece optical system without being reflected once is −0.04 <φ <0.01. If the lower limit of -0.04 of the above conditional expression is exceeded, the distant view external image is 25 cm.
If it is seen as close as possible and if it is seen closer than this, the accommodation power of the observer's eyes is insufficient. Further, if the upper limit of 0.01 is exceeded, an external image of 1 m can be observed at infinity, and if the upper limit is exceeded, it becomes impossible to clearly observe the external world beyond the accommodation power of the observer's eyes.

Third Embodiment A third embodiment will be described with reference to FIG. In the figure, 1 is a pupil position, 2 is a first semi-transmissive reflective surface, 3 is a second semi-transmissive reflective surface, and 4 is an image plane. In this embodiment, one meniscus lens L is used, the concave surface thereof is the first semi-transmissive reflective surface 2 and the convex surface thereof is the second semi-transmissive reflective surface 3, and further, an aspherical surface for image distortion correction. The lens LA is arranged on the image plane 4 side. Numerical examples are as shown below. In this embodiment, the angle of view is 60 ° and the focal length is F = 10 mm, F
The number is 2.0.

Surface number Radius of curvature Surface spacing nd νd 1 Pupil position 1 11.423 2 -14.4225 4.817 1.5163 64.1 3 -14.9832 (Reflecting surface 3) -4.817 1.5163 64.1 4 -14.4225 (Reflecting surface 2) 4.817 1.5163 64.1 5 -14.9832 0.046 6 12.5539 (aspherical surface) 0.914 1.5163 64.1 K = 0 A = -0.352385 × 10 ^-3 B = -0.213608 × 10 ^-5 C = 0 7 110.7802 1.857 8 Image plane 4 In the above, the aspherical surface has a conic constant of K and a non-spherical surface. When the spherical coefficients are A, B, and C, it is a rotationally symmetric surface represented by the following formula. However, in the following formula, R is a paraxial radius of curvature, and has a Z axis in the traveling direction of light on the optical axis and a Y axis in the direction orthogonal to the optical axis. Shows a similar aberration diagram and ^{Z = (Y 2 / R)} / [1+ {1- (1 + K) (Y / R) 2} 1/2] + AY 4 + BY 6 + CY 8 13 of the present embodiment in FIG. 15 .

Fourth Embodiment A fourth embodiment will be described with reference to FIG. This embodiment is similar to the second embodiment. Numerical examples are as shown below. In this embodiment, the angle of view is 45 ° and the focal length is F = 10.
mm, F number is 3.0.

Surface number Radius of curvature Surface spacing nd νd 1 Pupil position 1 13.127 2 -11.2445 5.633 1.5163 64.1 3 -14.0354 (Reflecting surface 3) -5.633 1.5163 64.1 4 -11.2445 (Reflecting surface 2) 5.633 1.5163 64.1 5 -14.0354 0.348 6 Image plane 4 FIG. 16 shows an aberration diagram similar to that of FIG. 13 of the present embodiment.

Fifth Embodiment A fifth embodiment will be described with reference to FIG. This embodiment is similar to the second embodiment. Numerical examples are as shown below. In this embodiment, the angle of view is 45 ° and the focal length is F = 10.
mm, F number is 3.0.

Surface number Radius of curvature Surface spacing nd νd 1 Pupil position 1 5.805 2 -24.3790 4.437 1.5163 64.1 3 -17.4632 (Reflecting surface 3) -4.437 1.5163 64.1 4 -24.3790 (Reflecting surface 2) 4.437 1.5163 64.1 5 -17.4632 3.193 6 Image plane 4 FIG. 17 shows an aberration diagram similar to that of FIG. 13 of the present embodiment.

Sixth Embodiment A sixth embodiment will be described with reference to FIG. This embodiment is similar to the second embodiment. Numerical examples are as shown below. In this embodiment, the angle of view is 45 ° and the focal length is F = 10.
mm, F number is 3.0.

Surface number Radius of curvature Surface spacing nd νd 1 Pupil position 1 7.259 2 -27.0911 4.287 1.5163 64.1 3 -18.0607 (Reflecting surface 3) -4.287 1.5163 64.1 4 -27.0911 (Reflecting surface 2) 4.287 1.5163 64.1 5 -18.0607 3.534 6 Image plane 4 FIG. 18 shows an aberration diagram similar to that of FIG. 13 of the present embodiment.

Seventh Embodiment A seventh embodiment will be described with reference to FIG. This embodiment is similar to the second embodiment. Numerical examples are as shown below. In this embodiment, the angle of view is 45 ° and the focal length is F = 1.
0 mm, F number is 3.0.

Surface number Curvature radius Surface spacing nd νd 1 Pupil position 1 9.152 2 -10.2521 5.711 1.5163 64.1 3 -13.6695 (Reflecting surface 3) -5.711 1.5163 64.1 4 -10.2521 (Reflecting surface 2) 5.711 1.5163 64.1 5 -13.6695 0.100 6 Image plane 4 FIG. 19 shows an aberration diagram similar to that of FIG. 13 of the present embodiment.

Eighth Embodiment An eighth embodiment will be described with reference to FIG. This embodiment is almost the same as the first embodiment. Numerical examples are as shown below. In this embodiment, the angle of view is 70 ° and the focal length is F.
= 10 mm, F number is 2.5.

Surface number Radius of curvature Surface spacing nd νd 1 Pupil position 1 8.255 2 ∞ 2.813 1.5163 64.1 3 -22.1680 0.355 4 -19.6995 5.058 1.5163 64.1 5 -18.7996 (Reflecting surface 3) -5.058 1.5163 64.1 6 -19.6995 -0.355 7- 22.1680 (Reflecting surface 2) 0.355 8 -19.6995 5.058 1.5163 64.1 9 -18.7996 0.520 10 Image plane 4 FIG. 20 shows an aberration diagram similar to FIG. 13 of the present embodiment.

Ninth Embodiment A ninth embodiment will be described with reference to FIG. In the figure, 1 is a pupil position, 2 is a first semi-transmissive reflective surface, 3 is a second semi-transmissive reflective surface, and 4 is an image plane. In this embodiment, a first semi-transmissive reflective surface 2 and a second semi-transmissive reflective surface 3 are provided in a plane parallel plate PP having a single refractive index. Numerical examples are as shown below. In this embodiment, the angle of view is 70 ° and the focal length is F.
= 10 mm, F number is 2.5.

Surface number Radius of curvature Surface spacing nd νd 1 Pupil position 1 8.255 2 ∞ 5.426 1.5163 64.1 3 -12.7792 2.822 1.5163 64.1 4 -12.9610 (Reflecting surface 3) -2.822 1.5163 64.1 5 -12.7792 (Reflecting surface 2) 3.322 1.5163 64.1 6 ∞ 3.455 7 Image plane 4 FIG. 21 shows an aberration diagram similar to that of FIG. 13 of the present embodiment.

The above conditional expression (2) (=
(6)), (3), (4), (5), (7) (=
The values of (8)) and (9) are shown in the following table.

[0067]

As is apparent from the above description, according to the visual display device of the present invention, it is possible to use a flat two-dimensional image display device, and it is possible to clearly observe a wide field angle up to a peripheral field angle. It is possible to provide a head-mounted visual display device.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the basic configuration of a concentric optical system that is an eyepiece optical system according to the present invention and the reason why aberrations are small.

FIG. 2 is a perspective view (a) of an example in which the visual display device of the present invention is installed in a game machine as a stationary type, and an enlarged view (b) of an eyepiece part thereof.

FIG. 3 is a perspective view of an example in which the visual display device of the present invention is configured as a goggle type head-mounted visual display device.

FIG. 4 is a sectional view of an optical system of the visual display device according to the first example of the present invention.

FIG. 5 is a sectional view of a second embodiment.

FIG. 6 is a sectional view of a third embodiment.

FIG. 7 is a sectional view of a fourth embodiment.

FIG. 8 is a sectional view of a fifth embodiment.

FIG. 9 is a sectional view of a sixth embodiment.

FIG. 10 is a sectional view of a seventh embodiment.

FIG. 11 is a sectional view of an eighth embodiment.

FIG. 12 is a sectional view of a ninth embodiment.

FIG. 13 is a longitudinal aberration diagram (a) and a lateral aberration diagram (b) showing spherical aberration, astigmatism, and distortion of the first example.

FIG. 14 is an aberration diagram similar to FIG. 13 of the second example.

FIG. 15 is an aberration diagram similar to FIG. 13 of the third example.

FIG. 16 is an aberration diagram similar to FIG. 13 of the fourth example.

FIG. 17 is an aberration diagram similar to FIG. 13 of the fifth example.

FIG. 18 is an aberration diagram similar to FIG. 13 of the sixth example.

FIG. 19 is an aberration diagram similar to FIG. 13 of the seventh example.

FIG. 20 is an aberration diagram similar to FIG. 13 of the eighth example.

FIG. 21 is an aberration diagram similar to FIG. 13 of the ninth example.

FIG. 22 is a sectional view showing an optical system of one conventional head-mounted visual display device.

FIG. 23 is a cross-sectional view of one conventional reflective eyepiece optical system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pupil position 2 ... 1st semi-transmissive reflective surface 3 ... 2nd semi-transmissive reflective surface 4 ... Image surface (two-dimensional image display element) 7 ... Positioning means (projection) 8 ... Support means (headband) M ... Game machine H ... Observer head S ... Eyepiece L, L1, L2 ... Meniscus lens LA ... Aspherical lens PP ... Parallel plane plate

Claims (1)

[Claims] 1. A visual display device comprising image display means for displaying an image, and an eyepiece optical system for projecting the image formed by said image display means and guiding it to an observer's eyeball.
The eyepiece optical system has a first semi-transmissive reflective surface having a center of curvature substantially on the optical axis and having a concave surface in the direction of the center of curvature, and a position substantially the same as the center of curvature of the first semi-transmissive reflective surface. A visual display device comprising: an eyepiece optical system having a second semi-transmissive reflecting surface having a center of curvature.