JP3346640B2 - Video display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video display device,
In particular, the present invention relates to a head or face-mounted image 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 video display device, it is important to reduce the size of the entire device and to reduce its weight so as not to impair the mountability. The factor that determines the size of the entire apparatus is the layout of the optical system. FIG. 20 shows an optical system of one conventional head-mounted image display device (Japanese Patent Laid-Open No. 3-10170).
No. 9). This image display device transmits a display image of a two-dimensional image display element as an aerial image by a relay optical system composed of a positive lens, enlarges the aerial image by an eyepiece optical system composed of a concave reflecting mirror, and enlarges the aerial image. It is projected in. 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 known. In these layouts, the projection amount of the device from the observer's face becomes large. Furthermore, in order to obtain a wide viewing angle of view, a large positive lens diameter and a large 2
It is necessary to use a two-dimensional image display device, and the device becomes larger and heavier at the same time.

[0003] In order to enable long-term observation without feeling tired or to be able to easily attach and detach, it is desirable to have a configuration in which a short and light eyepiece optical system is arranged immediately before the eyeball of the observer. In this case, the two-dimensional image display element, the illumination optical system, and the like can be arranged with a small amount of projection to the front of the observer's head, and the projection amount 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 increase the sense of reality when observing an image. In particular, the stereoscopic effect of the presented image is determined by the angle of view (Television Institute of Japan, Vol. 45, No. 12, pp. 1589-1596).
(1991)). The next important issue is how to realize an optical system that can obtain a wide angle of view and high resolution. In order to give the observer a three-dimensional feeling and a powerful feeling, 40
It is known that it is necessary to ensure a presentation angle of view of more than ° (± 20 °), and at the same time, the effect is saturated around 120 ° (± 60 °). That is, it is desirable to set the observation angle of view to 40 ° or more and as close to 120 ° as possible. However, in the case where the eyepiece optical system is a flat reflecting mirror, an extremely large two-dimensional image display element is required if light beams having an angle of view of 40 ° or more are incident on the observer's eyeball. Eventually, the entire device becomes large and heavy.

Further, due to the nature of the concave mirror, in order to generate a strong concave field curvature along the surface of the concave mirror, if a planar two-dimensional image display element is arranged at the focal position of the concave mirror, the observation image plane is not obtained. Is curved, and a clear observation image cannot be obtained up to the periphery of the visual field.

[0006]

As described above, conventionally, there is provided a small and lightweight video display device which can clearly observe the periphery of a visual field, can present an observation image to an observer with a wide observation angle of view, and can provide the same. Was very difficult. The present invention has been made in view of such problems of the prior art, and provides a video display device that is small, lightweight, has high resolution and a large exit pupil diameter while providing a wide viewing angle of view. It is assumed that.

Hereinafter, this point will be further described.
The aberration generated in the ocular optical system by the decentered concave reflecting mirror is large, and the field curvature, astigmatism,
Two types of aberration occur, such as coma aberration and pupil aberration which is not directly related to the imaging performance.

The above-mentioned aberration which directly affects the image forming performance can be corrected to some extent by using an eccentric surface or an aspherical surface in the relay optical system, but the pupil aberration which is not directly related to the image forming performance. The correction cannot be performed using an eccentric or aspherical surface in the relay optical system. This means that the entrance pupil of the eyepiece optical system and the exit pupil of the relay optical system, which are in an imaging relationship with the observer's pupil position, are shifted, and it is necessary to make the exit pupil diameter of the relay optical system very large. is there. If the pupil diameter of the relay optical system is not made large, problems such as vignetting around the viewing angle of view and insufficient resolution may occur. To deal with this problem, the pupil diameter of the relay optical system must be increased.However, increasing the pupil diameter of the relay optical system imposes a heavy burden on the relay optical system, and the relay optical system becomes larger. It gets complicated.

Hereinafter, the occurrence of the pupil aberration will be described with reference to FIG. 17 in which the relay optical system is omitted. FIG. 17 is a diagram illustrating pupil aberration generated by a concave eyepiece that is a conventional surface reflecting mirror. In this figure, the observer pupil position is 1, the concave reflecting mirror is 2, the visual axis in front of the observer is 3, and
The projection position (pupil position) of the observer's pupil by the concave mirror 2 is set to 4. In this drawing, the coordinate system is set such that the inside of the paper is in the YZ plane, and the perpendicular from the front surface to the back surface in the direction perpendicular to the paper surface is the X axis. This figure shows that the pupil diameter of the observer is 12 mm.
Ray tracing was performed assuming φ.

Further, FIG. 18A shows that only the on-axis light rays having the observer's pupil as the object point are traced. In FIG. 18A, similarly, the observer pupil position is 1, the eyepiece concave mirror is 2,
Assume that the visual axis in front of the observer is 3, and the projection position of the observer's pupil by the eyepiece concave mirror 2 is 4. In this figure, the observation angle of view of each of the principal rays 11 to 15 indicates the principal ray having the angle of view shown in the screen shown in FIG.

FIG. 19A is a diagram in which the light beam shown in FIG. 18A is projected onto an XZ section. In FIG. 19A, similarly, the observer pupil position is 1, the eyepiece concave mirror is 2, and the visual axis in front of the observer is 3. Rays 21-23, 3
The arrangement with respect to the viewing angle of view in the screen of FIGS.
This is shown in FIG.

FIG. 19A shows that the light ray 21 in the figure has an aberration particularly in the Z-axis direction. Accordingly, in FIG. 17, in order to display the leftward image of the right eye without vignetting, a relay lens having a large effective aperture and sufficiently corrected for aberrations is required, and the burden on the relay lens is increased. Is larger.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to observe an angle of view of 40 ° (± 20 °) or more, and to provide a flat and clear image to the periphery. An object of the present invention is to provide a small-sized image display device capable of observing an image and securing a wide exit pupil diameter.

[0014]

According to the present invention, there is provided a video display device having a flat screen for displaying a video, and a relay optical device for relaying the video to form a relay image. A video display device comprising a system and an eyepiece optical system that reflects a light beam emitted from the relay optical system and forms an exit pupil with the light beam, wherein the eyepiece optical system has a curved first surface and a second surface. And a light beam emitted from the relay optical system is reflected by the second surface after passing through the first surface, and the reflected light beam is transmitted through the first surface again. When the light axis connecting the image center and the exit pupil center is the optical axis, the second surface is eccentrically arranged with respect to the optical axis, and the curved shape is Rotationally asymmetrical aspherical shape for aberration correction It is characterized in that it has been configured.

[0015]

[0016]

[0017]

The operation of the present invention will be described below. In the following, for convenience in designing the optical system, a description will be given along the reverse tracing optical path for tracing light rays from the observer's pupil position toward the two-dimensional image display element.

In the eyepiece concave reflecting optical system, as shown in FIG. 19A, the distance from the pupil position 1 to the principal ray of each image height that spreads out and hits the reflecting surface 2 greatly differs. That is, for the light rays 21 and 31 in FIG. 19A, the light rays impinge on the concave reflecting mirror 2 at an early stage before the light rays largely spread, and the intersection with the Z axis is close to the pupil position 1. . On the other hand, since other rays have a relatively long distance until they hit the reflecting surface 2, the intersection with the Z axis is located at the pupil position 1
From far away. This is because the reflecting surface is greatly inclined in the YZ plane.

Therefore, the present invention solves the above problem by using a back mirror. FIG. 1 is a diagram showing pupil aberration in the X-axis direction by the concave eyepiece of the present invention. In FIG. 1, the observer pupil position is 1, the second surface of the eyepiece optical system is 2, the visual axis in front of the observer is 3, the projection position (pupil position) of the observer's pupil by the concave mirror 2 is 4, the eyepiece. The first surface of the optical system is denoted by 5 and the back mirror is denoted by 6. In the drawing, the coordinate system is set such that the inside of the paper is in the YZ plane, the perpendicular from the paper surface in the direction perpendicular to the paper surface to the back surface is the X axis, and in the case of this drawing, the observer's eyeball position is cut horizontally. FIG. 4 is a cross-sectional view of the horizontal section taken from above the observer's head.

In this figure, the observation angle of view of each chief ray is
FIG. 19 shows principal rays 11 to 15 having the angles of view shown in FIG. FIG. 2 shows the light beam of FIG. 1 projected on the XZ section.
It is. 2, the observer's pupil position is 1, the second surface of the eyepiece optical system is 2, the visual axis at the front of the observer is 3, the first surface of the eyepiece optical system is 5, and the rear mirror is 6. The arrangement of the light rays with respect to the observation angle of view is as shown in FIG. In FIG. 2, it can be seen that the light rays 21 and 31 are changed from the eyeball side to the concave mirror 2 side, particularly as compared with FIG. 19A.

As described above, by arranging the transmitting surface as the first surface 5 on the ocular concave mirror and setting an appropriate radius of curvature on the transmitting surface 5, the pupil aberration generated by the ocular concave mirror on the second surface 2 is improved. Can be corrected. The relationship between the surface shapes of the first surface 5 and the second surface 2 is such that, for example, as shown in FIG. 1, the distance between the first surface 5 and the second surface 2 increases in the Y direction. The above-mentioned pupil aberration can be favorably corrected.

Further, in order to correct the inclination of the image plane generated by the eyepiece concave mirror 2, the two-dimensional image display element corresponding to the image plane is tilted with respect to the axis of the relay optical system as shown in the embodiment described later. It is important to arrange them. This requires that the object plane, the relay optical system, and the image plane (two-dimensional image display element) be disposed at an angle, similarly to a tilt mechanism generally used for a camera lens or the like. As for the tilting method, there is a method in which the relay optical system is tilted or shifted with respect to an optical axis extending in a direction perpendicular to the screen of the two-dimensional image display element, similarly to the generally known tilt.

With the above configuration, a clear image with a wide angle of view and good aberration correction can be observed up to the periphery of an image using a small and lightweight relay optical system having a small pupil diameter. An image display device can be provided.

More preferably, the reflecting surface of the eyepiece concave mirror 2 is made aspherical so that the relay optical system 7
(FIG. 3), it is possible to correct the pupil aberration incident on the relay optical system 7, and further, the burden of the aberration correction of the relay optical system 7 is reduced.
The size of the relay optical system 7 can be reduced.

It is desirable that the reflecting surface of the ocular concave mirror 2 be an anamorphic surface. In this case, the paraxial radius of curvature R _{y in the} Y-axis direction is more than the paraxial radius of curvature R _{x in the} X-axis direction.
Is preferably set to be larger (| R
_x | <| R _y |). The reason is that it is possible to suppress the occurrence of complicated astigmatism generated due to the oblique incidence of the light beam on the ocular concave mirror 2, and to observe a clear observation image up to the periphery of the observation field angle.

Further, if the pupil position (exit pupil) 1 of the observer is arranged at a position farther from the eyepiece concave mirror 2 than the front focal position of the eyepiece concave mirror 2, the virtual object point at infinity formed by the eyepiece concave mirror 2 is obtained. It is possible to reduce the image plane,
Desirable for downsizing. The focal length of the eyepiece concave mirror 2 is F _R , the eyepiece concave mirror 2 and the observer iris position (exit pupil) 1
When the distance to D is D, it is preferable that the following conditional expression (1) is satisfied: D> 0.5 × F _R (1)

If the lower limit of the conditional expression (1) is exceeded, the light reflected by the eyepiece concave mirror 2 will be extremely widened, and the relay optical system 7 will become large, and the whole apparatus will become large.

If the distance between the eyepiece concave mirror 2 and the iris position 1 of the observer's eyeball or the rotation point of the eyeball is too short because the eyepiece concave mirror 2 is arranged immediately before the observer's eyeball, it may hit the eyelashes of the observer. Gives a sense of fear. For this reason, it is desirable that the distance D between the ocular concave reflective optical system 2 and the observer iris position 1 or the eye rotation point is set to be 30 mm or more, and D> 30 (mm) (2) It is preferable to satisfy (2).

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments 1 to 4 of the image display apparatus of the present invention will be described below.
Will be described with reference to the drawings, however, the coordinate system is set in such a manner that the inside of the paper is defined as a YZ plane, and a perpendicular line from the surface of the paper perpendicular to the paper to the back is defined as the X axis. 3 to 6
In each of the first to fourth embodiments, the right-eye video display device Y-
3 shows a Z section. For the left eye, it can be realized by symmetrically disposing all the constituent optical elements.

Embodiment 1 will be described with reference to FIG. In the figure,
1 is the observer's pupil position, 2 is a concave mirror that becomes the second surface of the eyepiece optical system, 3 is the observer's visual axis, 5 is the first surface of the eyepiece optical system, and 6 is the back surface composed of the first surface 5 and the second surface. Mirror, 7 is a relay optical system, 8
Is a two-dimensional image display element.

The present embodiment shows an embodiment in which the visual axis 3 is bent above the observer's head so that the two-dimensional image display element 8 is arranged near the observer's head. It is apparent that the visual axis 3 can be bent in the left-right direction of the head without being particular about this embodiment.

In this embodiment, the horizontal angle of view is 50 °, the vertical angle of view is 38.5 °, and the pupil diameter is 10 mmφ. In this embodiment, three groups of lenses are arranged in the relay optical system 7. Further, these three groups of lenses are arranged eccentrically.

FIGS. 4, 5 and 6 show Examples 2 to 4, respectively.
2 shows a YZ section of the image display device for the right eye of FIG. For the left eye, it can be realized by symmetrically disposing all the constituent optical elements. Since these embodiments are almost the same as the first embodiment, the description is omitted.

In the second embodiment, the horizontal angle of view is 50 ° and the vertical angle of view is 3
The pupil diameter is 8.5 mm and the pupil diameter is 10 mm. In this embodiment, the relay optical system 7 also includes three groups of lenses, each of which is arranged eccentrically.

In the third embodiment, the horizontal angle of view is 50 ° and the vertical angle of view is 3
8.5 °, the pupil diameter is 10 mmφ, and the relay optical system 7 is composed of three groups of lenses. However, the first and second groups are arranged coaxially, and the third group is polarized. I have a heart.

In the fourth embodiment, the horizontal angle of view is 50 ° and the vertical angle of view is 3
The pupil diameter is 8.5 mm and the pupil diameter is 10 mm. In this embodiment, the relay optical system 7 is constituted by two groups that are mutually decentered.

Although the constituent parameters of these embodiments 1 to 4 will be described later, the surface numbers are indicated by the reverse tracking surface numbers from the observer pupil position 1 to the two-dimensional image display element 8.

In the configuration parameters, the eccentricity and the inclination angle are given by the eccentricity and the inclination angle in the Y-axis direction for the first surface 5 and the second surface 2, and the eccentricity is such that the vertex is located at the center of the exit pupil 1. It is the distance decentered in the Y-axis direction from the passing visual axis 3 (Z-axis direction), and the tilt angle is the tilt angle of the central axis passing through the vertex from the Z-axis direction. Regarding the relay optical system 7, the amount of eccentricity in the Y-axis direction and the Z-axis direction from the visual axis 3 (Z-axis direction) passing through the center of the exit pupil 1 at the top of the first surface, and the center passing through the top of the surface The inclination angle of the axis from the Z-axis direction is given. In the subsequent coordinate system, first, the center axis of the first surface of the relay optical system 7 becomes the Z axis whose direction from the two-dimensional image display element 8 toward the back mirror 6 is positive, and is orthogonal to the Z axis on the paper surface. The Y-axis of the two-dimensional image display element 8 is converted into a positive Y-axis from the right to the left and an X-axis positive from the top to the bottom of the page. Thereafter, the eccentricity and the inclination angle of each subsequent surface are similarly given to the coordinate system of the preceding surface, and the coordinate system is similarly converted in order. The two-dimensional image display element 8 includes a relay optical system 7.
Is given by the amount of eccentricity of the center in the positive direction of the Y-axis in the coordinate system after the transformation on the last plane of, and the angle of inclination of the normal to the plane from the Z-axis.

In each surface, non-rotationally symmetric aspherical shapes are as follows: R _y and R _x are paraxial radius of curvature in the YZ plane (paper plane) and paraxial radius of curvature in the XZ plane, respectively. , K _x , _Ky
Are the conic coefficients in the X and Y directions, respectively, AR and BR are the rotationally symmetric fourth and sixth order aspheric coefficients, AP and BP, respectively.
Are asymmetric fourth-order and sixth-order aspherical coefficients, respectively.
The aspheric formula is as shown below.

Z = [(X ² / R _x ) + (Y ² / R _y )] / [1+
｛1- (1 + K _x ) (X ² / R _x ² )-(1 + K _y ) (Y ² / R _y ² )｝
^{1/2] + AR [(1-} AP) X 2 + (1 + AP) Y 2] 2 + B
The R [(1-BP) X 2 + (1 + BP) Y 2] 3, on each side, the aspherical shape of rotational symmetry, the paraxial curvature radius When R, is given by the following equation.

Z = (h ² / R) / [1+ ｛1- (1 + K) (h ² /
R ² )｝ ^1/2 ] + Ah ⁴ + Bh ⁶ (h ² = X ² + Y ² ) where K is a conical coefficient, and A and B are fourth-order and sixth-order aspherical coefficients, respectively.

The distance between the exit pupil 1, the first surface 5, and the second surface 2 is the distance in the Z-axis direction, the distance from the first surface of the relay optical system 7 to its image plane (two-dimensional image display). The distance to the element 8) is indicated by the distance along the central axis which is sequentially converted. The relay optical system 7, the radius of curvature of the surface r ₁ ~
In r _i, the surface interval d ₁ to d _i, the refractive index of the d line n ₁ ~
n _i denotes the Abbe number from ν _{1 to} ν _i . The first surface 5
The refractive index of the d-line of the medium between the first and second surfaces 2 is represented by n, and the Abbe number is represented by ν.

[0043] Example 1 Face Number of curvature radius interval refractive index Abbe number (eccentricity) (inclination angle) 1 (1) ∞ _{(pupil) 55.478 2 (5) R y} -79.448 2.183 n = 1.5163 ν = 64.1 R x - _{54.185 Y: 0 38.178 ° K y} 2.920316 K x 1.033415 AR 0 BR 0 AP 0 BP 0 3 (2) R y -75.750 ( reflecting surface) -2.183 n = 1.5163 ν = 64.1 R x -53.139 Y: 0 35.000 ° K _y 0.952212 K _x 0.236231 AR 0 BR 0 AP 0 BP 04 (5) R _y -79.448 0.000 Y: 0 38.178 ° R _x -53.185 Ky _y 2.920316 K _x 1.033415 AR 0 BR 0 AP 0 BP 05 (r ₁ ) -32.532 (d ₁ ) -3.876 n ₁ = 1.5163 ν ₁ = 64.1 Y: -48.645 45.962 ° Z: 40.120 K 0.000 A 0.150932 × 10 ^-4 B -0.111906 × 10 ^-6 6 (r ₂ ) ∞ (d ₂ ) _{-7.172 7 (r 3) -62.160 (} d 3) -10.169 n 2 = 1.5163 ν 2 = 64.1 Y: -1.752 6.723 ° K 0.000 A 0.173361 × 10 -3 B 0.183862 × 10 -5 8 (r 4) 11.390 ( d ₄ ) -4.587 K 0.000 A -0.771652 × 10 ^-4 B 0.397531 × 10 ^-6 9 (r ₅ ) -14.945 (d ₅ ) -1.000 n ₃ = 1.80518 ν ₃ = 25.4 Y: -4.249 17.790 ° 10 (r ₆ ) -9.997 (d ₆ ) -9.570 n ₄ = 1.62299 ν ₄ = 58.2 11 (r ₇ ) 22.177 (d ₇ ) -6.081 12 (8) ∞ (display element) Y: 1.292 25.274 °.

[0044] Example 2 Face Number of curvature radius interval refractive index Abbe number (eccentricity) (inclination angle) 1 (1) ∞ _{(pupil) 55.478 2 (5) R y} -66.710 1.615 n = 1.5163 ν = 64.1 R x - _{46.471 Y: 0 38.405 ° K y} 1.552160 K x 0.328920 AR 0 BR 0 AP 0 BP 0 3 (2) R y -71.230 ( reflecting surface) -1.615 n = 1.5163 ν = 64.1 R x -50.647 Y: 0 35.000 ° K _y 0.653431 K _x -0.028880 AR 0 BR 0 AP 0 BP 04 (5) R _y -66.710 0.000 Y: 0 38.405 ° R _x -46.471 Ky _y 1.552160 K _x 0.328920 AR 0 BR 0 AP 0 BP 05 (r ₁ ) -26.436 (d ₁ ) -3.565 n ₁ = 1.5163 ν ₁ = 64.1 Y: -48.076 50.540 ° Z: 35.767 6 (r ₂ ) 1882.524 (d ₂ ) -10.618 7 (r ₃ ) -36.075 (d ₃ )- 8.804 n ₂ = 1.5163 ν ₂ = 64.1 Y: -3.865 2.575 ° K 0.000 A 0.177586 × 10 ^-3 B 0.199270 × 10 ^-5 8 (r ₄ ) 12.098 (d ₄ ) -2.485 K 0.000 A -0.843954 × 10 ^-4 B 0.773669 × 10 ^-6 9 ( _{5) -22.343 (d 5) -1.000} n 3 = 1.80518 ν 3 = 25.4 Y: -3.029 20.685 ° 10 (r 6) -12.777 (d 6) -9.106 n 4 = 1.62299 ν 4 = 58.2 11 (r 7) 17.230 (d ₇ ) -6.860 12 (8) ∞ (display element) Y: 2.734 19.857 °.

Example 3 Surface Number Curvature Radius Interval Refractive Index Abbe Number (Eccentricity) (Tilt Angle) 1 (1) ∞ (pupil) 55.478 2 (5) _Ry -40.468 1.744 n = 1.5163 ν = 64.1 R _x − 31.469 Y: 0 40.451 ° K _y -1.328390 K _x -1.588026 AR 0 BR 0 AP 0 BP 03 (2) R _y -51.506 (reflection surface) -1.744 n = 1.5163 ν = 64.1 R _x -39.370 Y: 0 35.000 _{° K y -1.118580 K x -1.176330 AR} 0 BR 0 AP 0 BP 0 4 (5) R y -40.468 0.000 Y: 0 40.451 ° R x -31.468 K y -1.328390 K x -1.588026 AR 0 BR 0 AP 0 BP 05 (r ₁ ) -21.374 (d ₁ ) -3.125 n ₁ = 1.5163 ν ₁ = 64.1 Y: -43.979 43.423 ° Z: 35.940 6 (r ₂ ) 800.331 (d ₂ ) -1.453 7 (r ₃ ) -63.646 _{(d 3) -13.803 n 2 =} 1.5163 ν 2 = 64.1 Y: -3.865 2.575 ° K 0.000 A 0.924995 × 10 -4 B 0.211168 × 10 -6 8 (r 4) 17.122 (d 4) -0.100 K 0.000 A - 0.267880 × 10 ^-4 B -0.520031 × 10 ^-7 9 ( r ₅ ) -12.680 (d ₅ ) -7.393 n ₃ = 1.62299 ν ₃ = 58.2 Y: -5.586 4.670 ° 10 (r ₆ ) 11.422 (d ₆ ) -1.000 n ₄ = 1.80518 ν ₄ = 25.4 11 (r ₇ ) 27.614 (d ₇ ) -8.341 12 (8) ∞ (display element) Y: -1.549 37.828 °.

Example 4 Surface Number Curvature Radius Interval Refractive Index Abbe Number (Eccentricity) (Tilt Angle) 1 (1) ∞ (pupil) 55.478 2 (5) _Ry -56.427 2.027 n = 1.5163 ν = 64.1 R _x- 40.352 Y: 0 38.802 ° K _y -1.854057 K _x -1.725595 AR 0 BR 0 AP 0 BP 03 (2) R _y -62.797 (reflective surface) -2.027 n = 1.5163 ν = 64.1 R _x -45.362 Y: 0 35.000 _{° K y -1.122810 K x -1.101846 AR} 0 BR 0 AP 0 BP 0 4 (5) R y -56.427 0.000 Y: 0 38.802 ° R x -40.352 K y -1.854057 K x -1.725595 AR 0 BR 0 AP 0 BP 0 5 (r ₁ ) -25.011 (d ₁ ) -18.001 n ₁ = 1.5163 ν ₁ = 64.1 Y: -50.956 60.986 ° Z: 32.884 K 0 A 0.568562 × 10 ^-4 B 0.268245 × 10 ^-6 6 (r ₂ ) 17.125 (d ₂ ) -4.211 K 0 A -0.294893 × 10 ^-4 B 0.793536 × 10 ^-7 7 (r ₃ ) -13.769 (d ₃ ) -13.759 n ₂ = 1.62299 ν ₂ = 58.2 Y: -4.080 -11.028 ° 8 (r ₄ ) 12.447 (d ₄ ) -1.000 n ₃ = 1.80518 ν ₃ = 25.4 9 (r ₅ ) 41.400 (d ₅ ) -6.489 10 (8) ∞ (display element) Y: -2.228 40.443 °.

FIGS. 7 and 8, FIGS. 9 and 10, FIGS. 11 and 12, and FIGS.
3 to 14. In these figures, (1) is the visual axis direction of the screen (0 ° vertically, 0 ° horizontally), (2) is 0 ° vertically, 19.3 ° horizontally, and (3) is the screen. Vertical direction 25 °, horizontal direction −19.3 °, (4) vertical direction 25 °, horizontal direction 0 °, (5) vertical direction 25 °,
19.3 ° in the left-right direction, (6) is 0 ° in the up-down direction, 19.3 ° in the left-right direction, and (7) is 0 ° in the up-down direction, -13.
5 °, (8): vertical direction 17.5 °, horizontal direction -13.
5 °, (9) is vertical 17.5 °, horizontal 0 °,
(10) is vertical 17.5 °, horizontal 13.5 °,
(11) shows values in the horizontal direction (Y direction) and the vertical direction (X direction) at 0 ° in the vertical direction and 13.5 ° in the horizontal direction.

In the above description, the concave mirror 2 serving as the second surface of the eyepiece optical system is considered to be constituted by a total reflection mirror. However, this is used as a half mirror which transmits a predetermined amount of light. You may comprise. As a form of the half mirror, for example, as shown in FIGS. 15A to 15C, a partially transmitting partially reflecting surface 41 provided on the surface of the optical member 9 of the back mirror 6, a semi-transmitting film 42, Semi-permeable membrane 43
Any of the following may be used. That is, the half mirror 2 is a surface that transmits about 50% of the light amount and reflects about 50%, and the ratio is used in a range of 1: 9 to 9: 1. As means therefor, there are a method of dividing an incident light beam as an area, a method of dividing the intensity thereof, and a method of performing both of them. In the case of the partially transmitting partial reflecting surface 41 in FIG. 15A, an example in which the light amount is divided by the area, a reflective coating of aluminum or the like is provided on the surface of the optical member 9 (its refractive index n is n> 1). Performs discretely such as meshes of about several μm to 0.1 mm, and overall (macro-like) according to the ratio of the area of the reflecting part and the part of the part that transmits without reflecting.
The optimal reflectance and transmittance are set. FIG.
5 (b) semipermeable membrane (semitransparent)
The film 42 is the optical member 9 (its refractive index n is n
> 1) the surface is coated with a metal ultra-thin film such as an ultra-thin aluminum film or an ultra-thin chromium film, or a semi-transmissive film made of a dielectric multilayer film such as SiO ₂ or MgF ₂ to divide the light amount . Further, in FIG. 15C, the light amount is divided by separating the polarization component of the incident light. That is, the polarizing semi-transmissive film 43 is coated on the surface of the optical member 9 (its refractive index n is n> 1),
This is to selectively transmit or reflect P-polarized light and S-polarized light to split incident light.

Although the image display apparatus of the present invention has been described based on several embodiments, the present invention is not limited to these embodiments, and various modifications can be made. Then, the image display device of the present invention is mounted on a head-mounted image display device (HMD).
For example, as shown in FIG. 16A, a horizontal sectional view, and FIG. 16B, a perspective view, a headband 51 is attached and attached to the observer's head for use as the 50. . In the case of FIG. 16A, the second surface 2 of the back mirror 6 is constituted by any half mirror of FIG.
A shutter 52 is provided in front of the line of sight 3 of the user, and the shutter 52 is opened to selectively or externally display an external image.
To be superimposed on the video.

The invention set forth in the above claims can be further configured as follows. (4) The first surface and the second surface both have concave surfaces facing the relay optical system and the exit pupil.
Or 3 image display devices.

(5) The image display device according to (4), wherein the first surface is provided on a concave side of the second surface, and the second surface is a reflecting surface for reflecting a light beam.

(6) The image according to (4), wherein the first surface is provided on the concave surface side of the second surface, and the second surface comprises a semi-transmissive reflection surface for partially transmitting and reflecting the light beam. Display device.

(7) The video display device according to claim 1, wherein the distance between the first surface and the second surface increases in an arbitrary direction.

(8) The image display device according to (7), wherein the arbitrary direction is from the relay optical system side to the exit pupil side.

(9) At least a part of the relay optical system is eccentrically arranged with respect to an optical axis from the image display element extending in a direction perpendicular to the screen.
2 or 3 image display devices.

(10) The image display device according to (9), wherein the eccentricity is a tilt arrangement.

(11) The image display device according to (9), wherein the eccentricity is a shift arrangement.

(12) The image display device according to any one of (1) to (3) or (1) to (11), wherein the second surface is an aspherical surface.

(13) The image display device according to any one of (1) to (3) or (1) to (12), wherein the second surface is an anamorphic surface.

(14) The image display device according to (13), wherein the anamorphic surface satisfies the following conditions.

| R _x | <| R _y | where R _x is the paraxial radius of curvature in the X-axis direction, and R _y is the paraxial radius of curvature in the Y-axis direction.

(15) The video display device according to any one of (1) to (3) or (1) to (14), which satisfies the following conditions.

D> 0.5 × F _R where D is the distance between the second surface and the exit pupil, F
_R is the focal length of the second surface.

(16) The video display device according to any one of (1) to (3) or (1) to (15), wherein the following conditions are satisfied.

D> 30 (mm) where D is the distance between the second surface and the exit pupil.

[0066]

As is apparent from the above description, according to the video display device of the present invention, it is possible to provide a head mounted video display device that can clearly observe a peripheral angle of view with a wide presentation angle of view. it can.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating pupil aberration in the X-axis direction by an eyepiece concave mirror according to the present invention.

FIG. 2 is a diagram in which the light beam of FIG. 1 is projected on an XZ section.

FIG. 3 is a right-eye image display device according to a first embodiment of the present invention;
It is -Z sectional drawing.

FIG. 4 is a YZ sectional view of a right-eye image display device according to a second embodiment.

FIG. 5 is a YZ sectional view of a right-eye image display device according to a third embodiment.

FIG. 6 is a YZ sectional view of a right-eye image display device according to a fourth embodiment.

FIG. 7 is an aberration diagram illustrating a part of the lateral aberration in the first embodiment.

FIG. 8 is an aberration diagram showing a remaining lateral aberration in the first embodiment.

FIG. 9 is an aberration diagram showing part of the lateral aberration in the second embodiment.

FIG. 10 is an aberration diagram showing a remaining lateral aberration in the second embodiment.

FIG. 11 is an aberration diagram showing part of the lateral aberration in the third embodiment.

FIG. 12 is an aberration diagram showing a remaining lateral aberration in the third embodiment.

FIG. 13 is an aberration diagram showing part of the lateral aberration in the fourth embodiment.

FIG. 14 is an aberration diagram showing a residual lateral aberration in the fourth embodiment.

FIG. 15 is a diagram for explaining a form of a half mirror used in the present invention.

FIG. 16 is a horizontal sectional view and a perspective view of a head mounted image display device according to the present invention.

FIG. 17 is a diagram illustrating pupil aberration generated by a conventional eyepiece concave mirror.

18 is a diagram illustrating pupil aberration in the X-axis direction in FIG.

19 is a diagram in which the light beam of FIG. 18 is projected on an XZ cross section.

FIG. 20 is a diagram showing an optical system of one conventional head-mounted image display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pupil position 2 ... 2nd surface (reflection surface) of eyepiece optical system 3 ... Visual axis which hits the front of an observer 4 ... Projection position of observer's pupil 5 ... 1st surface (refractive surface) of eyepiece optical system 6 ... Back mirror 7 ... Relay optical system 8 ... Two-dimensional image display element 9 ... Optical member 11-15, 21-23, 31-33 ... Light ray 41 ... Partially transmissive partial reflection surface 42 ... Semi-transmissive film 43 ... Polarizing semi-transmissive film 50 head-mounted image display device (HMD) 51 headband 52 shutter

Claims (13)

(57) [Claims] An image display element having a planar screen for displaying an image, a relay optical system for relaying the image to form a relay image, and reflecting a light beam emitted from the relay optical system; An image display device comprising an eyepiece optical system that forms an exit pupil with a light beam, wherein the eyepiece optical system has a curved first surface and a second surface, and a light beam emitted from the relay optical system is: After being transmitted through the first surface, the light is reflected by the second surface, and the reflected light flux is transmitted through the first surface again, and connects the image center and the exit pupil center. When the light beam is the optical axis, the second surface is eccentrically arranged with respect to the optical axis, and the curved shape is a rotationally asymmetric aspherical shape for aberration correction. An image display device characterized by the following. 2. The eyepiece optical system, wherein the first surface and the second surface have a refractive index (n) greater than 1 (n> 1).
2. The image display device according to claim 1, wherein the image display device is configured with an optical member interposed therebetween, and wherein the second surface is configured by a back reflection mirror. 3. A face mounting unit including the image display element, the relay optical system, and the eyepiece optical system, and a support member for holding the face mounting unit on an observer's head. The video display device according to claim 1 or 2, wherein: 4. The relay optical system according to claim 1, wherein the first surface has a concave shape, the second surface has a concave shape, and both the first surface and the second surface have a concave side. 3. The device according to claim 1, further comprising:
Or the video display device according to 3. 5. The video display device according to claim 4, wherein the first surface is provided on a concave side of the second surface. 6. The transflective surface according to claim 4, wherein said second surface is a semi-transmissive reflecting surface for partially transmitting and reflecting the remaining light beam.
The image display device according to the above. 7. The method according to claim 1, wherein the first surface and the second surface are arranged such that a distance between the first surface and the second surface increases in an arbitrary direction. The image display device according to claim 4, wherein 8. The first surface and the second surface are arranged such that the arbitrary direction is a direction from the relay optical system side to the exit pupil side. 8. The image display device according to 7. 9. At least a part of the relay optical system includes:
4. The video display device according to claim 1, wherein the video display device is eccentrically arranged with respect to an optical axis from the video display element extending in a direction perpendicular to the screen. 10. The image display device according to claim 4, wherein said rotationally asymmetric aspherical surface of said second surface is constituted by an anamorphic surface. 11. The image display device according to claim 10, wherein the anamorphic surface satisfies the following condition. | R _x | <| R _y | where R _x is a paraxial radius of curvature in the X-axis direction, and R _y is a paraxial radius of curvature in the Y-axis direction. 12. The image display device according to claim 4, wherein the eyepiece optical system is configured to satisfy the following condition. D> 0.5 × F _R where D is the distance between the second surface and the exit pupil, F
_R is the focal length of the second surface. 13. The image display device according to claim 4, wherein the eyepiece optical system is configured to satisfy the following condition. D> 30 (mm) where D is the distance between the second surface and the exit pupil.