JPH08184780A - Picture display device - Google Patents

Abstract

PURPOSE: To provide the picture display device of a head mounted type picture display device or the like where a clear observation is realized at a wide field angle and also which prevents a user from being tired owing to its small-size and light weight. CONSTITUTION: This device is constituted of a picture display element 6 and an ocular optical system 7 leading a displayed picture to the eye-ball 1 of an observer, and the ocular optical system 7 has a first face 3 on the side of the eye-ball 1 and a succeeding second face 4, and a space between the first face 3 and the second face 4 is filled with a medium having >=1 refractive index, and also two faces are disposed eccentricly in the same direction as a visual line 2, and the second face 4 is constituted of a reflective or semitransmissive face, and the second face 4 is constituted of a curved face having a recessed face opposite the side of the eye-ball of the observer, and also the first face 3 and the second face 4 have different curvatures, and a light beam emitted from the picture display element 6 is refracted by the first face 3 and is reflected by the second face 4 and is refracted again by the first face 3 and a primary picture obtained by the ocular optical system 7 of the picture display element 6 is made incident on the eye-ball 1 of the observer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device,
In particular, it 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 Conventionally, a known head-mounted image display device is disclosed in Japanese Patent Laid-Open No. 3-101709.
This image display device, as shown in the optical path diagram in FIG.
The display image of the three-dimensional image display element is transmitted as an aerial image by the relay optical system consisting of a positive lens, and the aerial image is enlarged and projected into the observer's eyeball by the eyepiece optical system consisting of a concave reflecting mirror. .

Another conventional type is US Pat. No. 4,669,810. As shown in FIG. 20, this device forms an intermediate image of a CRT image through a relay optical system and projects the image on a viewer's eye by a combiner having a reflective holographic element and a hologram surface.

Another conventional type of image display device is disclosed in JP-A-62-214782. As shown in FIGS. 21 (a) and 21 (b), this apparatus is an apparatus in which an image display element is magnified by an eyepiece lens and can be directly observed.

Another conventional type of image display device is disclosed in US Pat. No. 4,026,641.
As shown in FIG. 22, this device transmits an image of an image display element to a curved object surface by a transmission element and projects the object surface in the air by a toric reflection surface.

[0006]

However, as shown in FIG.
9. In an image display device of a type that relays an image of an image display device as shown in FIG. 20, several lenses must be used as a relay optical system other than the eyepiece optical system regardless of the eyepiece optical system. Is long, the optical system becomes large,
The weight becomes heavy. Further, in the layout as shown in FIG. 21, the amount of device protrusion from the observer's face becomes large. In addition, the image display device and the illumination optical system will be attached to the protruding part, and the device will become larger and larger.
The weight becomes heavy.

The head-mounted image display device is a device to be mounted on the human body, especially on the head. Therefore, if the amount of the device protruding from the face is large, the head-supported image display device is supported by the head and the center of gravity of the device is supported. Distance becomes longer, the balance at the time of wearing is poor, and fatigue increases. Furthermore, when the device is mounted and moved, rotated, or the like, the device may collide with an object. That is, it is important that the head-mounted image display device is small and lightweight. A major factor that determines the size and weight of this device is the configuration of the optical system.

However, when only an ordinary magnifying glass is used as the eyepiece optical system, the generated aberration is very large and there is no means for correcting it. Even if spherical aberration is corrected to some extent by making the concave surface of the magnifying glass aspherical, coma, field curvature, etc. remain, so increasing the observation angle of view does not make it a practical device. . Alternatively, when only a concave mirror is used as the eyepiece optical system, not only a normal optical element (lens or mirror) but also a transmission element (which has a curved surface according to the generated field curvature as shown in FIG. Fiber plate) must be used to compensate.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to enable clear observation in a wide angle of view, and also to be fatigued because it is very small and lightweight. An object is to provide an image display device such as a difficult head-mounted image display device.

[0010]

An image display device of the present invention that achieves the above object comprises an image display element for displaying an image,
In an image display device comprising an eyepiece optical system for projecting an image formed by the image display element and guiding the image to an observer's eyeball, the eyepiece optical system has at least two surfaces, and the observation of the at least two surfaces is performed. First side of the eyeball side
Surface, and the surface following this surface is the second surface, and the space between the first surface and the second surface is filled with a medium having a refractive index of 1 or more, and at the same time, the at least two surfaces are the centers of the projected images observed by the observer. Both are eccentrically arranged in the same direction with respect to the visual axis that is the direction, and further, the second surface is constituted by a reflective or semi-transmissive surface, and the second surface has a concave surface facing the observer's eyeball side. The first surface and the second surface have different curvatures, and light rays emitted from the image display element are refracted by the first surface and reflected by the second surface, It is characterized in that it is further refracted on the surface and is made to enter the primary image of the image display element by the eyepiece optical system into the observer's eyeball.

Another image display device according to the present invention comprises an image display device for displaying an image and an eyepiece optical system for projecting the image formed by the image display device and guiding it to the observer's eyeball. In the above, the eyepiece optical system has at least two surfaces, and of the at least two surfaces, the surface on the eyeball side of the observer is the first surface, and the surface following this is the second surface, and the first surface and the second surface. The space between the two is filled with a medium having a refractive index of 1 or more, and at the same time, the at least two surfaces are eccentrically arranged in the same direction with respect to the visual axis which is the central direction of the projection image observed by the observer. Further, the second surface is
It is composed of a reflective or semi-transmissive surface, the second surface is composed of a curved surface with a concave surface facing the viewer's eyeball side, and the first surface and the second surface have different curvatures. The emitted light is refracted by the first surface, reflected by the second surface, further refracted by the first surface, and the primary image by the eyepiece optical system of the image display element is incident on the observer's eyeball. It is characterized in that an optical element having a positive refractive power is arranged between the eyepiece optical system and the observer's eyeball.

In this case, a lens having a positive refractive power can be used as the optical element having a positive refractive power.

[0013]

The operation of the image display device of the present invention will be described below. In the following description, for the convenience of designing the optical system, the reverse ray tracing for tracing the ray from the observer's pupil position toward the image display element is performed. In the present invention, the eyepiece optical system has two surfaces, the first surface and the second surface.
By giving different curvatures to the surfaces, it becomes possible to correct the spherical aberration and the coma aberration generated on the decentered and tilted second surface, which has a wide exit pupil diameter and a wide observation angle of view.
It succeeded in providing a clear observation image to the observer.

Generally, in a concave mirror, when the pupil position is far from the center of curvature as viewed from the reflecting surface of the concave mirror, strong inner coma aberration occurs. In order to correct this strong internal coma aberration, in the present invention, the space between the first surface and the second surface, which is a concave mirror, is filled with a medium having a refractive index of 1 or more, and at the same time, the first surface and the second surface.
By making the curvatures of the surfaces different, it is possible to lower the height of the light rays incident on the second surface by utilizing the refraction effect of the light rays on the first surface. By this action, the occurrence of strong inner coma aberration generated by the concave mirror has been successfully made relatively small.

Further, in the present invention, the observation image of the image display element is not formed as an intermediate image by the relay optical system to form a real image in the air, but the image display element is directly magnified and projected on the eyeball of the observer. As a result, the observer can observe the magnified image of the image display element as a virtual image, and thus the optical system can be configured with a small number of optical elements.
In addition, the optical element for magnifying and projecting is only a concave mirror (magnifying mirror) that is placed in a shape that follows the curve of the face immediately in front of the observer's face, so the amount of projection from the face can be extremely small, and it is compact. It is possible to realize a lightweight image display device.

It is important that the first surface of this eyepiece optical system is a surface having a negative refractive power with a concave surface facing the viewer's eyeball side. By giving the first surface a negative refractive power,
On the surface, negative spherical aberration occurs. This has the effect of canceling out the positive spherical aberration generated by the concave mirror and correcting the generation of spherical aberration.

In this case, the coma aberration is relatively large, but the coherence of the entire aberration is improved, and a good result is obtained. However, the curvature of the first surface is the second
If the curvature is approximately equal to the curvature of the surface, the correction effect will be reduced for both coma aberration and spherical aberration.

Also, the radius of curvature R _y1 of the first surface of the eyepiece optical system
It is important that the radius of curvature R _y2 of the second surface satisfy the following conditional expression. R _y1 / R _y2 <2 (1) The formula (1) is important for correcting coma aberration generated on the second surface that is inclined, particularly high-order coma aberration or coma flare. It is a condition. Especially, when the inclination angle of the second surface becomes large, it is important to satisfy this condition.

As in the present invention, in an image display apparatus using an eyepiece optical system in which a concave mirror tilted in front of the observer's eyeball is arranged, the light rays incident on the concave mirror are oblique and therefore not symmetrical with respect to the central axis of the concave mirror. Complex coma occurs. This complicated coma increases as the tilt angle of the concave mirror increases. In order to realize a compact image display device having a wide angle of view, it is difficult to secure an observation image with a wide angle of view because the image display element and the observation optical path interfere unless the tilt angle is increased. Therefore, the tilt angle of the concave mirror becomes larger as the image display device becomes wider and has a smaller size, and it becomes important to correct the occurrence of high-order coma aberration. Therefore, it is important to satisfy the coma aberration correction condition expressed by the conditional expression (1).

Further, the radius of curvature R of the first surface of the eyepiece optical system
It is important that _y1 and the radius of curvature R _y2 of the second surface satisfy the following conditional expression. R _y1 / R _y2 <1 (2) Equation (2) is also important for correcting coma aberration generated on the second surface that is inclined, particularly high-order coma aberration or coma flare. It is a condition. This is important when ensuring an observation angle of view of approximately 30 ° or more. When the upper limit of 1 of the equation (2) is exceeded, the correction of high-order coma aberration generated on the second surface cannot be completely corrected on the first surface, and it becomes difficult to observe a clear observation image up to the periphery.

Furthermore, it is important that the radius of curvature R _y1 of the first surface and the radius of curvature R _y2 of the second surface of the eyepiece optical system satisfy the following conditional expressions. R _y1 / R _y2 <0.8 (3) The formula (3) is also used to correct coma aberration generated on the second surface that is inclined, especially high-order coma aberration or coma flare. This is an important condition, and is important when ensuring an observation angle of view of approximately 35 ° or more. When the upper limit of 0.8 in the formula (3) is exceeded, it becomes difficult to correct high-order coma aberration particularly on the second surface in a wide angle of view, and it becomes difficult to observe a clear observation image up to the periphery. .

Let R _y2 be the radius of curvature of the second surface of the eyepiece optical system in the plane including the observer's visual axis and including the center of the image display element, and it is orthogonal to this plane and is the first in the plane including the observer's visual axis. the radius of curvature of the two surfaces when the R _x2, it is important that R _y2 and R _x2 are different. This condition is a condition for correcting aberration that occurs because the second surface is tilted with respect to the visual axis. In general,
When the spherical surface is tilted, the light rays incident on the surface have different curvatures with respect to the light rays in the plane of incidence and the plane orthogonal to the plane of incidence. Therefore, in the eyepiece optical system which is arranged eccentrically with respect to the visual axis as in the present invention, astigmatism also occurs in the observation image on the visual axis which is the center of the observation image for the above reason. In order to correct this astigmatism on the axis, it is important to make the radius of curvature different between the entrance surface of the second reflecting surface and the surface orthogonal to the entrance surface.

The radii of curvature R _y2 and R _x2 of the second surface of the eyepiece optical system
It is important that the relation of is satisfied with the following conditions. R _y2 / R _x2 ≦ 1 (4) When the upper limit of 1 to the conditional expression (4) is exceeded, the radius of curvature for the rays in the plane of incidence and in the plane orthogonal to the plane of incidence is the same as described above. It becomes difficult to correct the astigmatism that occurs due to the difference.

The radius of curvature R _y2 of the second surface of the eyepiece optical system
It is important for the relationship between R _x2 and R _x2 to satisfy the following conditions. R _y2 / R _x2 <0.8 (5) When the upper limit of 0.8 in the conditional expression (5) is exceeded, it becomes insufficient to correct the above-mentioned astigmatism, and The observation image becomes unclear, and it becomes impossible to observe a wide observation angle of view. Further, the inclination angle of the second surface becomes small, and it becomes impossible to realize a small-sized image display device.

By disposing an optical element having a positive refracting power between the eyepiece optical system and the observer's eyeball, the diameter of the light beam on the second surface of the eyepiece optical system becomes small, so that high-order coma aberration occurs. It is possible to observe the image clearly around the image display screen. Further, since the chief ray in the periphery of the image is refracted by the optical element having a positive refractive power, the height of the ray incident on the eyepiece optical system can be lowered, and the observation image can be further improved as compared with the case of only the eyepiece optical system. It is possible to set a large angle.

Further, by using a lens as an optical element having a positive refracting power, it is possible to provide an image display device which has good manufacturability, is inexpensive, has a wide angle of view, and is clear to the periphery of the screen.

Further, by disposing the optical element having the positive refracting power so as to be decentered with respect to the visual axis, it is possible to obtain a good result for the correction of the high-order coma aberration generated on the decentered second surface.

Further, by constructing the optical element having the positive refracting power by the cemented lens, it is possible to correct the chromatic aberration of magnification which occurs in the lens having the positive refracting power, and it becomes clearer and has a wider angle of view. This is effective when securing a large observation image.

Further, by constructing the second surface of the eyepiece optical system with an anamorphic aspherical surface, not only astigmatism on the visual axis but also astigmatism and coma of the peripheral image can be corrected. .

Further, it is desirable that the second surface of the eyepiece optical system is not on the visual axis but is tilted with respect to the visual axis and at the same time is decentered. By decentering the apex of the second surface, it is possible to correct the coma aberration that occurs asymmetrically between the image on the image display element side and the image on the opposite side with respect to the visual axis, and to adjust the surface on which the image display element is arranged. It is possible to dispose the optical axis substantially perpendicular to the optical axis after the reflection on the second surface. This is effective when using a liquid crystal display element having poor viewing angle characteristics.

In the present invention, by providing the image display element and the eyepiece optical system with respect to the head of the observer, the observer can observe a stable observation image.

Further, by providing a means for positioning 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, the observer can freely observe the posture and observe. It is possible to observe the image in the direction.

Furthermore, by providing the supporting means for supporting at least two sets of image display devices at a constant interval, the observer can easily observe with both the left and right eyes. In addition, it is possible to enjoy a stereoscopic image by displaying images with parallax on the left and right image display surfaces and observing them with both eyes.

[0034]

Embodiments 1 to 8 of an image display device of the present invention will be described below with reference to the drawings. The constituent parameters of each embodiment will be described later, but in the following description, the surface number is shown as the surface number of the backward tracking from the observer's pupil position 1 toward the image display element 6. As shown in FIG. 1 to FIG. 8, the coordinates are taken with the Z axis being the visual axis direction from the center of the observer's pupil position 1 and the positive direction being the direction from the front surface to the back surface in the direction perpendicular to the paper surface. It is assumed that the X axis is taken, the Y axis that is perpendicular to the X axis and the Z axis and constitutes the right-hand system is taken in the plane of the paper, and the optical axis is bent in the YZ plane of the paper.

Then, in the constituent parameters described later, with respect to the surface on which the eccentricity amounts Y and Z and the tilt angle θ are described, the Y of the apex of the surface with respect to the reference surface (1st surface, 4th surface). It means the amount of eccentricity in the axial direction, the Z-axis direction, and the angle of inclination of the central axis of the surface from the Z-axis, and in this case, θ means counterclockwise. It should be noted that a surface on which the eccentricity amounts Y and Z and the tilt angle θ are not described means that it is coaxial with the surface before it.
However, regarding Example 7, for 3 to 7 planes, the coordinates obtained by rotating the original coordinates by the inclination angle θ (−15 °) given by the 2 planes with the vertex of the 2 planes as the origin. Y
Axis and Z-axis become new Y-axis and Z-axis, and the new Y-axis direction, the amount of eccentricity of the surface apex in the Z-axis direction, and the inclination angle θ of the central axis from the new Z-axis The eccentricity amounts Y and Z and the tilt angle θ are given.

The surface spacing is the distance along the Z axis from one surface with respect to two surfaces, and the position becomes the reference point, and the point of the eccentricity Y from the reference point becomes the top of the two surfaces. . For the coaxial system portion (optical element 8 having a positive power), this is the axial distance from that surface to the next surface. The surface spacing is
The direction of backtracking is shown as positive along the optical axis.

Further, in each surface, the aspherical shape of non-rotationally symmetric shape has coordinates R _y and R _x on the coordinates defining the surface, respectively, where R _y and R _x are the paraxial radius of curvature in the YZ plane (paper surface) and X−, respectively. Paraxial radii of curvature in the Z plane, K _x and K _y are the X-Z plane and Y-, respectively.
The conical coefficients in the Z plane, AR and BR, are rotationally symmetric 4th and 6th aspherical coefficients with respect to the Z axis, and AP and BP are rotationally asymmetrical 4th and 6th non-spherical coefficients with respect to the Z axis, respectively. Assuming the spherical coefficient, the aspherical expression 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 + BR [(1-BP) X ² + (1 + BP) Y ² ] ³ Further, The rotationally symmetric aspherical shape on each surface is given by the following equation, where R is the paraxial radius of curvature.

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 are conic coefficients, and A and B are fourth-order and sixth-order aspherical coefficients, respectively. The refractive index of the medium between the surfaces is expressed by the d-line refractive index. The unit of length is mm.

The following embodiments are all image display devices for the right eye, and all the optical elements for the left eye are X-.
It can be realized by symmetrically arranging in the Z plane. Further, it goes without saying that in an actual device, the direction in which the optical axis is bent by the eyepiece optical system may be above, below, or lateral to the observer.

1 to 8 are sectional views of the monocular image display devices of Examples 1 to 8, respectively. In each sectional view, 1 is the observer's pupil position, 2 is the observer's visual axis, 3 is the first surface of the eyepiece optical system, 4 is a concave mirror forming the second surface of the eyepiece optical system, and 5 is the eyepiece optical system. 3rd surface (common to 1st surface 3), 6
Is an image display element, 7 is an eyepiece optical system including a first surface 3, a second surface (reflection surface) 4 and a third surface 5, and 8 is an optical system having a positive power.

The actual ray path in each embodiment is that the ray bundle emitted from the image display element 6 is sequentially refracted by the third surface 5 of the eyepiece optical system 7, reflected by the second surface (concave mirror) 4, and first surface. In the case of Examples 1, 2, and 8, the light is refracted at 3, and the iris position of the observer's pupil or the center of rotation of the eyeball is directly projected as the exit pupil 1 into the observer's eyeball. In this case, the iris position of the observer's pupil or the center of rotation of the eyeball is projected as the exit pupil 1 into the observer's eyeball through the optical system 8 having a positive power.

Example 1 In this example, the horizontal angle of view is 30 °, the vertical angle of view is 22.7 °, and the pupil diameter is 4 mm, and the first surface 3 and the second surface 4 of the eyepiece optical system 7 are
The third surface 5 is an anamorphic aspherical surface.

Example 2 In this example, the horizontal angle of view is 30 °, the vertical angle of view is 22.7 °, and the pupil diameter is 4 mm. The first surface 3 and the third surface 5 of the eyepiece optical system 7 are toric surfaces. , The second surface 4 is an anamorphic aspherical surface.

Example 3 In this example, the horizontal angle of view is 30 °, the vertical angle of view is 22.7 °, and the pupil diameter is 4 mm, and the first surface 3 and the second surface 4 of the eyepiece optical system 7 are
The third surface 5 is an anamorphic aspherical surface. Also, pupil 1
Between the eyepiece optical system 7 and the eyepiece optical system 7, a single lens 8 having a positive power and formed of a spherical surface without decentering is provided.

Example 4 In this example, the horizontal field angle was 35 °, the vertical field angle was 26.6 °, and the pupil diameter was 4 mm, and the first surface 3 and the second surface 4 of the eyepiece optical system 7 were
The third surface 5 is an anamorphic aspherical surface. Also, pupil 1
Between the eyepiece optical system 7 and the eyepiece optical system 7, a single lens 8 having a positive power and formed of a spherical surface is provided eccentrically with respect to the visual axis 2.

Example 5 In this example, the horizontal angle of view is 40 °, the vertical angle of view is 30.6 °, and the pupil diameter is 4 mm, and the first surface 3 and the second surface 4 of the eyepiece optical system 7 are
The third surface 5 is an anamorphic aspherical surface. Also, pupil 1
Between the eyepiece optical system 7 and the ocular optical system 7, a single lens 8 having a positive power, one surface of which is an aspherical surface and the other of which is a spherical surface, is arranged eccentrically with respect to the visual axis 2.

Example 6 In this example, the horizontal angle of view is 40 °, the vertical angle of view is 30.6 °, and the pupil diameter is 4 mm, and the first surface 3 and the second surface 4 of the eyepiece optical system 7 are
The third surface 5 is an anamorphic aspherical surface. Also, pupil 1
Between the eyepiece optical system 7 and the ocular optical system 7, each surface is a spherical surface, and a single lens 8 having a positive power, which is decentered, is provided.

Example 7 In this example, the horizontal angle of view was 40 °, the vertical angle of view was 30.6 °, and the pupil diameter was 4 mm, and the first surface 3 and the second surface 4 of the eyepiece optical system 7 were
The third surface 5 is an anamorphic aspherical surface. Also, pupil 1
Between the eyepiece optical system 7 and the eyepiece optical system 7, an optical system 8 having a positive power and composed of a cemented lens of a concave lens and a convex lens each having a spherical surface is provided eccentrically with respect to the visual axis.

Example 8 In this example, the horizontal angle of view is 30 °, the vertical angle of view is 22.7 °, and the pupil diameter is 4 mm, and the first surface 3 and the third surface 5 of the eyepiece optical system 7 are flat surfaces. The two surfaces are spherical surfaces.

Next, the constituent parameters of Examples 1 to 8 will be shown. Example 1 Surface number Curvature radius Spacing Refractive index Abbe number (eccentricity) (tilt angle) 1 ∞ (pupil) 50.000 2 R _y -115.364 1.5633 64.15 R _x -127.909 (from one surface) K _y -7.421305 Y 0 θ 30.00 ° K _x 0 AR 8.46165 × 10 ^-8 BR -7.76339 × 10 ^-18 AP -1.87052 BP 2.58902 × 10 ² 3 R _y -70.852 1.5633 64.15 R _x -70.635 (from one surface) K _y -1.36906 × 10 ^-1 Y -16.545 θ 7.00 ° K _x -5.4533 × 10 ^-2 Z 58.547 AR 3.62791 × 10 ^-12 BR 3.72459 × 10 ^-11 AP -7.25017 × 10 BP -1.07422 4 R _y -115.364 (from one surface) R _x -127.909 Y 0 θ 30.00 ° K _y -7.421305 Z 50.000 K _x 0 AR 8.46165 × 10 ^-8 BR -7.76339 × 10 ^-18 AP -1.87052 BP 2.58902 × 10 ² 5 (image display element) (from one surface) Y -16.162 θ 16.10 ° Z 28.408 (1) R _y1 / R _y2 = 1.63 (4) R _y2 / R _x2 = 1.00.

Example 2 Surface number Curvature radius Spacing Refractive index Abbe number (Eccentricity) (Inclination angle) 1 ∞ (pupil) 32.000 2 R _y -36.183 1.5633 64.15 R _x 111.868 (from one surface) Y 0 θ 30.00 ° 3 R _y -49.444 1.5633 64.15 R _x -97.994 (from one surface) K _y 0 Y -32.692 θ -11.259 ° K _x 0 Z 39.000 AR 2.36416 × 10 ^-7 BR -5.3209 × 10 ^-10 AP -5.56393 × 10 ^-1 BP -1.186116 4 R _y -36.183 (From 1 surface) R _x 111.868 Y 0 θ 30.00 ° Z 32.000 5 (Image display element) (From 1 surface) Y -23.089 θ 37.54 ° Z 17.216 (1) R _y1 / R _y2 = 0.73 (4) _Ry2 / _Rx2 = 0.50.

Example 3 Surface number Curvature radius Spacing Refractive index Abbe number (eccentricity) (tilt angle) 1 ∞ (pupil) 20.000 2 89.043 2.000 1.4870 70.40 3 -35.868 4 R _y -30.763 1.5633 64.15 R _x -58.178 (1 K _y 8.5269 × 10 ^-2 Y 0 θ 30.00 ° K _x -8.323018 Z 42.660 AR -8.98778 × 10 ^-8 BR 9.49781 × 10 ^-10 AP 4.09749 BP -2.00615 5 _Ry -54.312 1.5633 64.15 R _x -72.939 (From surface 1) K _y 0 Y -21.154 θ 3.17 ° K _x 0 Z 49.660 AR 4.30715 × 10 ^-7 BR 5.97047 × 10 ^-15 AP -1.87208 BP -4.75833 × 10 6 R _y -30.763 (From surface 1) R _x -58.178 Y 0 θ 30.00 ° K _y 8.5269 × 10 ^-2 Z 42.660 K _x -8.323018 AR -8.98778 × 10 ^-8 BR 9.49781 × 10 ^-10 AP 4.09749 BP -2.00615 7 (Image display element) Y -13.709 θ 36.717 ° (1) R _y1 / R _y2 = 0.57 (4) R _y2 / R _x2 = 0.74.

Example 4 Surface number Curvature radius Spacing Refractive index Abbe number (Eccentricity) (Inclination angle) 1 ∞ (pupil) 20.686 2 60.659 3.910 1.4870 70.40 (from one surface) Y -1.095 θ -15.45 ° 3 -53.427 4 R _y -27.822 1.5633 64.15 R _x -147.601 (from one surface) K _y -9.2496 × 10 ^-1 Y 0 θ 30.00 ° K _x 0 Z 36.000 AR -8.97807 × 10 ^-8 BR 3.07711 × 10 ^-11 AP 1.58667 × 10 BP -4.11804 5 R _y -54.141 1.5633 64.15 R _x -78.603 (from one surface) K _y 0 Y -16.961 θ 5.49 ° K _x 0 Z 42.955 AR -1.11 106 × 10 ^-7 BR 5.80094 × 10 ^-15 AP 1.95015 BP- 2.90911 × 10 6 R _y -27.822 (from one surface) R _x -147.601 Y 0 θ 30.00 ° K _y 9.2496 × 10 ^-1 Z 36.000 K _x 0 AR -8.97807 × 10 ^-8 BR 3.07711 × 10 ^-11 AP 1.58667 × 10 BP -4.11804 7 (image display device) (from one surface) Y-15.418 θ 30.699 ° Z 24.646 (1) R _y1 / R _y2 = 0.51 (4) R _y2 / R _x2 = 0.69.

Example 5 Surface number Curvature radius Spacing Refractive index Abbe number (Eccentricity) (Inclination angle) 1 ∞ (pupil) 19.865 2 153.020 4.000 1.4870 70.40 (from one surface) K -287.670 Y -0.344 θ -21.36 ° A ^{3.48592 × 10 -7 B -7.86793 × 10} -9 3 -37.717 4 R y -29.433 1.5633 64.15 R x ∞ ( from one _{side) K y -2.697475 Y 0 θ 30.00} ° K x 0 Z 35.000 AR -1.38537 × 10 - ^{8 BR 3.68465 × 10 -11 AP 2.35979} × 10 BP -4.34114 5 R y -47.976 1.5633 64.15 ( from one _{side) R x -81.052 K y 0 Y} -18.821 θ 1.58 ° K x 0 Z 41.952 AR -7.30519 × 10 - ⁷ BR 1.73135 × 10 ^-15 AP -9.32438 × 10 ^-1 BP -6.43587 × 10 6 R _y -29.433 (from one surface) R _x ∞ Y 0 θ 30.00 ° K _y -2.697475 Z 35.000 K _x 0 AR -1.38537 × 10 ^-8 BR 3.68465 × 10 ^-11 AP 2.35979 × 10 BP -4.34114 7 (Image display element) (From one surface) Y -14.061 θ 29.869 ° Z 24.680 (1) R _y1 / R _y2 = 0.61 (4) R _y2 / R _x2 0.59.

Example 6 Surface number Curvature radius Spacing Refractive index Abbe number (Eccentricity) (Inclination angle) 1 ∞ (Pupil) 22.125 2 211.333 1.4870 70.40 (From 1 surface) Y 5.732 θ -21.28 ° 3 -38.907 (1 surface) Y) 3.955 θ -10.87 ° Z 25.041 4 R _y -28.926 1.4870 70.40 R _x ∞ (from one surface) K _y -1.655529 Y 0 θ 30.00 ° K _x 0 Z 35.000 AR -1.56055 × 10 ^-8 BR 1.68174 × 10 ^-10 AP 1.74304 × 10 BP -2.08703 5 R _y -46.424 1.5633 64.15 R _x -71.978 (From one surface) K _y 0 Y -18.891 θ 0.10 ° K _x 0 Z 41.772 AR -2.25009 × 10 ^-8 BR 1.09724 × 10 ^-15 AP -4.13001 BP -6.40157 × 10 6 R _y -28.926 (from one surface) R _x ∞ Y 0 θ 30.00 ° K _y -1.655529 Z 35.000 K _x 0 AR -1.56055 × 10 ^-8 BR 1.68174 × 10 ^-10 AP 1.74304 × 10 BP -2.08703 7 (image display element) (from one surface) Y -13.686 θ 28.515 ° Z 24.461 (1) R _y1 / R _y2 = 0.62 (4) R _y2 / R _x2 = 0.64.

Example 7 Surface number Curvature radius Spacing Refractive index Abbe number (Eccentricity) (Inclination angle) 1 ∞ (Pupil) 22.000 2 79.298 6.000 1.6200 60.30 (From 1 surface) Y -3.096 θ -15.00 ° 3 -39.864 1.000 _{1.7550 27.60 4 -57.753 5 R y -28.332} 1.5633 64.15 R x ∞ ( from four ^{_{faces) K y -2.14084 × 10 -1 Y}} 0 θ 30.00 ° K x 0 Z 18.000 AR 2.67938 × 10 -6 BR -2.14615 × 10 - ⁹ AP 4.32917 × 10 ^-1 BP 5.86993 × 10 ^-1 6 R _y -39.619 0 1.5633 64.15 R _x -67.799 (from 4 sides) K _y 0 Y -9.093 θ 15.98 ° K _x 0 Z 24.500 AR 2.14587 × 10 ^-6 BR -3.20475 x 10 ^-10 AP -1.39 488 x 10 ^-1 BP -9.57286 x 10 ^-1 7 R _y -28.332 -13.113 (from 4 surfaces) R _x ∞ Y 0 θ 30.00 ° K _y -2.14084 x 10 ^-1 Z _{18.000 K x 0 AR 2.67938 × 10} -6 BR -2.14615 × 10 -9 AP 4.32917 × 10 -1 BP 5.86993 × 10 -1 8 ( image display device) (1 side than) Y -16.158 θ 37.542 ° Z 34.338 (1 _{) R y1 / R y2 = 0.72} (4 R _y2 / R _x2 = 0.58.

Example 8 Surface number Curvature radius Spacing Refractive index Abbe number (Eccentricity) (Inclination angle) 1 ∞ (Pupil) 37.534 2 ∞ 1.5633 64.15 (From one surface) Y 0 θ 31.31 ° 3 -71.813 1.5633 64.15 (1 Y -14.754 θ 8.97 ° Z 46.891 4 ∞ (From 1 surface) Y 0 θ 31.31 ° Z 37.534 5 (Image display element) (From 1 surface) Y -11.946 θ 18.429 ° Z 21.500 (1) R _y1 / R _y2 = ∞ (4) R _y2 / R _x2 = 1.

Next, lateral aberration charts of Example 1, Example 3, and Example 7 among the above Examples are shown in FIGS. 9 to 11 and FIG. 1, respectively.
2 to 14 and FIGS. 15 to 17. In these lateral aberration diagrams, the numbers in parentheses represent (horizontal angle of view, vertical angle of view), and the lateral aberration at that angle of view.

Although the image display device of the present invention has been described based on some 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 used as a head-mounted image display device (HM
For example, as shown in the sectional view of FIG. 18A and the perspective view of FIG.
3 is fixedly supported in accordance with the eye radiation distance, a headband 10 is attached to this, and the headband 10 is used by being worn on the head of an observer. In the case of this use example, the second surface of the eyepiece optical system is a semi-transmissive mirror (half mirror), and the liquid crystal shutter 11 is provided in front of this half mirror to selectively select an external image or to display an image on the image display device. It is possible to superimpose it on the image so that it can be observed.

The image display device of the present invention described above is
For example, it can be configured as follows. [1] In an image display device comprising an image display element for displaying an image and an eyepiece optical system for projecting an image formed by the image display element and guiding it to an observer's eyeball, the eyepiece optical system has at least two surfaces. Of the at least two surfaces, the surface on the eyeball side of the observer is the first surface, the surface following the first surface is the second surface, and the space between the first surface and the second surface is filled with a medium having a refractive index of 1 or more. At the same time, said at least two faces are
The two are eccentrically arranged in the same direction with respect to the visual axis which is the central direction of the projection image observed by the observer, and the second surface is a reflective or semi-transmissive surface, and the second surface is The first surface and the second surface have different curvatures, and the light beam emitted from the image display element is refracted at the first surface, An image display device, characterized in that it is reflected by two surfaces, further refracted by the first surface, and enters a primary image of the image display element by the eyepiece optical system into an observer's eyeball.

[2] The image display device according to the above [1], wherein the light beam emitted from the image display element is directly projected onto the eyeball of an observer.

[3] The image display device according to the above [1] or [2], wherein the first surface of the eyepiece optical system is configured as a transmission surface having a concave surface facing the viewer's eye. .

[4] The radius of curvature of the first surface and the second surface of the surface including the viewer's visual axis and including the center of the image display element is R
_{When y1} and R _y2 are satisfied, the condition R _y1 / R _y2 <2 (1) is satisfied, [1],
The image display device according to [2] or [3].

[5] The condition that the radius of curvature R _y1 of the first surface of the eyepiece optical system and the radius of curvature R _y2 of the second surface of the eyepiece optical system are R _y1 / R _y2 <1 (2) [1], which is characterized by satisfying
The image display device according to [2] or [3].

[6] The radius of curvature R _y1 of the first surface of the eyepiece optical system and the radius of curvature R _y2 of the second surface of the eyepiece optical system are R _y1 / R _y2 <0.8 (3) The above [1] characterized by satisfying the condition,
The image display device according to [2] or [3].

[7] The radius of curvature of the second surface of the eyepiece optical system in a plane including the observer's visual axis and including the center of the image display element is R _y2, and is orthogonal to this plane. The radius of curvature of the second surface of the eyepiece optical system in the plane including the visual axis is R _x2
The image display device according to the above [1], [2] or [3], wherein R _x2 and R _y2 are different.

[8] Let R _y2 be the radius of curvature of the second surface of the eyepiece optical system in a plane including the observer's visual axis and including the center of the image display element, and set the radius of curvature in the plane orthogonal to this plane. When the radius of curvature of the second surface of the eyepiece optical system is R _x2 , the radius of curvature R _x2 and R _y2 of the second surface of the eyepiece optical system is R _y2 / R _x2 ≦ 1 (4) The image display device according to the above [1], [2] or [3].

[0068]

[9] The radius of curvature R _x2 and R _y2 of the second surface of the eyepiece optical system is R _y2 / R _x2 <0.8 (5), [1], [2] or The image display device as described in [3].

[10] In an image display device comprising an image display element for displaying an image and an eyepiece optical system for projecting an image formed by the image display element and guiding it to the observer's eyeball, the eyepiece optical system is at least Of the at least two surfaces, the surface on the eyeball side of the observer is the first surface, and the surface following the second surface is the second surface, and the surface between the first surface and the second surface has a refractive index of 1 or more. At the same time as filling with the medium, the at least two surfaces are both eccentrically arranged in the same direction with respect to the visual axis which is the central direction of the projection image observed by the observer, and further, the second surface is It is composed of a reflective or semi-transmissive surface, the second surface is composed of a curved surface with a concave surface facing the viewer's eyeball side, and the first surface and the second surface have different curvatures. The emitted light beam is refracted at the first surface, and is reflected by the second surface. And is further refracted at the first surface, and is configured to enter the primary image of the image display element by the eyepiece optical system into the observer's eyeball, and further, the eyepiece optical system and the observer eyeball. An image display device, characterized in that an optical element having a positive refracting power is provided between them.

[11] The image display device according to the above [10], wherein the optical element having a positive refractive power is a lens having a positive refractive power.

[12] The image display device according to the above [10], wherein the optical element having a positive refractive power is decentered with respect to the observer's visual axis.

[13] The image display device according to the above [10], wherein the optical element having a positive refractive power is a cemented lens.

[14] The image display device according to the above [1], [2] or [3], wherein the second surface of the eyepiece optical system is an anamorphic aspherical surface.

[15] The above-mentioned [1], [2] or [3], wherein the second surface of the eyepiece optical system is tilted and decentered at the same time with respect to the visual axis.
The image display device described.

[16] The image display device according to the above [1] or [10], further comprising positioning means for positioning the image display element and the eyepiece optical system with respect to the observer's head.

[17] The above-mentioned [1] or [1], which has a supporting means for supporting the image display element and the eyepiece optical system with respect to the observer's head and can be mounted on the observer's head. 10] The image display device as described above.

[18] The image display device according to the above [1] or [10], further comprising support means for supporting at least two sets of the image display device at a constant interval.

[0078]

As is apparent from the above description, according to the image display device of the present invention, it is possible to provide a very small and lightweight image display device with a wide observation angle of view.

[Brief description of drawings]

FIG. 1 is an optical path diagram of an image display device according to a first embodiment of the present invention.

FIG. 2 is an optical path diagram of an image display device according to a second embodiment of the present invention.

FIG. 3 is an optical path diagram of an image display device according to a third embodiment of the present invention.

FIG. 4 is an optical path diagram of an image display device of Example 4 of the present invention.

FIG. 5 is an optical path diagram of an image display device according to a fifth embodiment of the present invention.

FIG. 6 is an optical path diagram of an image display device of Example 6 of the present invention.

FIG. 7 is an optical path diagram of an image display device according to a seventh embodiment of the present invention.

FIG. 8 is an optical path diagram of an image display device of Example 8 of the present invention.

FIG. 9 is a part of a lateral aberration diagram of Example 1 of the present invention.

FIG. 10 is another portion of the lateral aberration diagram of Example 1 of the present invention.

FIG. 11 is the remaining portion of the lateral aberration diagram for Example 1 of the present invention.

FIG. 12 is a part of a lateral aberration diagram of Example 3 of the present invention.

FIG. 13 is another part of the transverse aberration diagram for Example 3 of the present invention.

FIG. 14 is the remaining portion of the lateral aberration diagram for Example 3 of the present invention.

FIG. 15 is a part of a lateral aberration diagram of Example 7 of the present invention.

FIG. 16 is another portion of the lateral aberration diagram of Example 7 of the present invention.

FIG. 17 is the remaining portion of the lateral aberration diagram for Example 7 of the present invention.

FIG. 18 is a sectional view and a perspective view of the head-mounted image display device according to the present invention.

FIG. 19 is a diagram showing an optical system of one conventional image display device.

FIG. 20 is a diagram showing an optical system of another conventional image display device.

FIG. 21 is a diagram showing an optical system of still another conventional image display device.

FIG. 22 is a diagram showing an optical system of another conventional image display device.

[Explanation of symbols]

 1 ... Observer pupil position 2 ... Observer visual axis 3 ... First surface of eyepiece optical system 4 ... Concave mirror forming second surface of eyepiece optical system 5 ... Third surface of eyepiece optical system 6 ... Image display element 7 ... Eyepiece optical system 8 ... Optical system having positive power 10 ... Headband 11 ... Liquid crystal shutter 13 ... Head mounted image display device (HMD)

Claims (3)

[Claims] 1. An image display device comprising an image display element for displaying an image and an eyepiece optical system for projecting an image formed by the image display element and guiding it to an observer's eyeball, wherein the eyepiece optical system is at least 2 Of the at least two surfaces, the surface on the eyeball side of the observer is the first surface, and the surface following the first surface is the second surface, and the refractive index between the first surface and the second surface is 1
At the same time as being filled with the above medium, the at least two surfaces are arranged so as to be eccentric in the same direction with respect to the visual axis which is the central direction of the projection image observed by the observer. Is a reflective or semi-transmissive surface, and the second surface is a curved surface with a concave surface facing the eyeball of the observer,
Further, the first surface and the second surface have different curvatures, and the light ray emitted from the image display element is refracted by the first surface, reflected by the second surface, and further refracted by the first surface. An image display device, characterized in that a primary image of the image display device by the eyepiece optical system is incident on an observer's eyeball. 2. An image display device comprising an image display element for displaying an image and an eyepiece optical system for projecting the image formed by the image display element and guiding it to an observer's eyeball, wherein the eyepiece optical system is at least 2 Of the at least two surfaces, the surface on the eyeball side of the observer is the first surface, and the surface following the first surface is the second surface, and the refractive index between the first surface and the second surface is 1
At the same time as being filled with the above medium, the at least two surfaces are arranged so as to be eccentric in the same direction with respect to the visual axis which is the central direction of the projection image observed by the observer. Is a reflective or semi-transmissive surface, and the second surface is a curved surface with a concave surface facing the eyeball of the observer,
Further, the first surface and the second surface have different curvatures, and the light ray emitted from the image display element is refracted by the first surface, reflected by the second surface, and further refracted by the first surface. , An optical element having a positive refractive power is arranged between the eyepiece optical system and the observer's eyeball so that a primary image of the image display element by the eyepiece optical system is incident on the observer's eyeball. An image display device characterized by being provided. 3. The optical element having a positive refractive power is a lens having a positive refractive power.
The image display device described.