JPH05323229A - Visual display device - Google Patents

Abstract

PURPOSE:To obtain a portable visual display device attached to a head or a face especially enabling clear observation with a wide viewing angle. CONSTITUTION:In the visual display device comprizing a two dimensional display element 1 displaying an observation image, an eyepiece optical system 2 composed of a reflection surface or a semi-transparent reflection surface, projecting the enlarged two dimensional display element 1 or the projection image of the element in air and bending the optical axis, and a supporting means supporting the eyepiece optical system 2 at the position just before the user's eye, the curvature of the eyepiece optical system 2 on the plane (Y-Z plane) where the axis of the visual display device is bent is made large on the A' side far from the bending position of the axis B' viewed from the two dimensional display element 1 and the focal surface on which the two-dimensional display element 1 is arranged is made a plane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable visual display device, and more particularly 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 Conventionally, as a face-mounted visual display device,
It is known that a plan view is shown in FIG. 18 (US Pat. No. 4,026,641). This is because the image of the image display device 46 such as a CRT is displayed on the object plane 12 by the image transfer device 25.
To the toric reflecting surface 10
It is designed to be projected in the air by.

[0003]

In such a face-mounted visual display device, the two-dimensional image display element is arranged as follows.
In order to avoid mechanical interference with the observer's head, the eyepiece optical system, that is, the angle at which the lens is bent (angled) by the optical system placed in front of the eye is increased, or at a position away from the eyepiece optical system. The eyepiece optical system was placed away from the observer's eyeball.

Therefore, in the conventional example in which a concave reflecting mirror is used as an eyepiece optical system, the aerial image cannot be viewed as a distant plane by an observer unless the object plane is located near the front focal point of the concave mirror. In a toric surface (anamorphic surface) reflecting mirror, its focal plane becomes a toric surface having a curvature, and when a flat two-dimensional image display element or an image of a two-dimensional image display element is placed on the focal plane, the object For the observer who is observing the aerial image reflected by the eyepiece optical system because the periphery of the surface is displaced from the focal plane in the optical axis direction, the aerial image projected on the curved surface is observed, and the periphery of the visual field is clear. Can not be observed.

The present invention has been made to solve the above problems, and an object thereof is to provide a portable head-type or face-mounted visual display device capable of clearly observing a particularly wide angle of view. Is to provide.

[0006]

A visual display device of the present invention which achieves the above-mentioned object, comprises a two-dimensional display element for displaying an observation image, an enlarged projection of the two-dimensional display element or its projected image in the air, and a light display. A visual display device comprising an eyepiece optical system composed of a reflecting surface or a semi-transmissive reflecting surface for bending an axis, and a supporting means for supporting the eyepiece optical system so as to be positioned immediately in front of the eyeball of the user, The curvature of the eyepiece optical system in the plane in which the optical axis of the display device bends is set to be higher on the side farther from the position where the optical axis bends when viewed from the two-dimensional display element. It is a thing.

In this case, the bending angle of the optical axis formed by the incident optical axis and the outgoing optical axis to the eyepiece optical system is preferably 20 ° or more, and the focal length of the eyepiece optical system is 50 to 200 mm.
It is desirable to be in the range of.

[0008]

The function and operation of adopting the above configuration will be described below. For the face-mounted visual display device, in order to secure a large angle of view, the concave mirror arranged immediately in front of the observer's eye needs to have a large angle of view. However, the spherical concave mirror having a wide angle of view has a focal plane of a spherical surface having a small radius of curvature, and a flat aerial image is observed for a flat two-dimensional image display element or a projected image of the two-dimensional image display element. I can't.

Therefore, in the present invention, the curvature of the reflecting surface in the direction in which the optical axis of the eyepiece optical system is bent is relatively high (the radius of curvature is small), and the curvature of the reflecting surface in the direction opposite to the bending direction is compared. The above problem is solved by making the front focal plane of the eyepiece optical system flat by making it relatively low (the radius of curvature is large), and correcting the aberration satisfactorily. This makes it possible to directly form a two-dimensional image display element or a projected image of the two-dimensional image display element as a plane on the front focal plane of the eyepiece optical system, and obtain a clear observation image with a wide angle of view. Like

This action will be described below with reference to FIG. 1 in which a toric surface of the prior art is used as an eyepiece optical system. FIG. 1 is a sectional view of an optical system corresponding to the right eye for an observer. In this figure, 1 is a two-dimensional display element or an aerial image projection position of the two-dimensional display element, 2 is a toric surface reflecting mirror which is an eyepiece optical system, and 3 is an observer eyeball rotation center or iris center position. .. Reference numeral 5 denotes a light flux corresponding to the left visual field for the observer, 6 denotes a light flux of an observation image observed on the front, and 7 denotes a light flux of an observation image observed on the right.
The toric surface also has the same shape as the spherical surface when viewed in the meridian plane, as shown in FIG.

Generally, when forming an image at infinity with a spherical concave reflecting mirror, an object point must be placed at a focus position which is a half of the radius of curvature of the concave surface. But,
The off-axis light beam obliquely incident on the central axis of the concave mirror causes field curvature, so that the object plane 1 becomes a curved surface. Therefore, unless the two-dimensional image display element is a curved surface, the observer cannot obtain an infinity observation image. But,
The display element having such a curved surface has poor manufacturability.

Therefore, in the present invention, a relatively high curvature (curvature in the Y-axis positive direction in the drawing) of the optical axis when viewed from the two-dimensional display element 1 of the reflecting surface 2 in FIG. 1 is used. By making the radius small), the object plane 1 is corrected to a flat surface, and an observation image having a high resolution for a wide angle of view is successfully provided.

That is, since the radius of curvature of the eyepiece optical system 2 at the part where the light beam 5 is reflected is relatively smaller than that at the other parts, the point A on the object plane 1 is along the optical axis.
, The object surface 1 is flattened. The optical axis referred to here is a so-called on-axis ray that passes through the center of rotation of the observer's eyeball or the center 3 of the iris and passes through the display center of the two-dimensional display element 1.

More preferably, positions A ', B', C'on the eyepiece optical system 2 where the light beams 5, 6, 7 which are respectively on the left side, the center, and the right side of the visual field for the observer are reflected by the eyepiece optical system 2. Then, as shown by the solid line in FIG. 2, it is possible to increase the change amount of the curvature from the position B ′ where the optical axis is reflected to the position A ′ by using a plane two-dimensional display element. This is important for obtaining a flat observation image.

Further, the bending angle θ of the optical axis is preferably 20 ° or more, and when it is 20 ° or less, the observer's eyeball position 3 and the two-dimensional image display element 1 are close to each other, and the two-dimensional image display is performed. It becomes impossible to dispose the element 1.

Further, the focal length of the eyepiece optical system 2 is 50
It is desirable to set the distance to ~ 200 mm, and if the lower limit is exceeded, the distance between the observer's eyeball position 3 and the eyepiece optical system 2 becomes too short, and the observer feels a sense of pressure when wearing this visual display device. It becomes impossible to secure a wide angle of view. On the other hand, when the upper limit is exceeded, the distance between the observer's eyeball position 3 and the eyepiece optical system 2 becomes large, and the projection amount of the eyepiece optical system 2 from this visual display device becomes large, so that the present visual display device is mounted. The wearing feeling becomes worse.

[0017]

EXAMPLES Examples 1 to 5 of the visual display device of the present invention will be described below.
Will be described. Example 1 FIG. 3 shows a cross section in the Y-axis direction of the optical system of this example. With respect to the coordinate axes, with the center of the observer eyeball iris position 3 as the origin, as shown in the figure, the optical axis direction passing through the center of the observer eyeball iris position 3 is the Z axis, the left-right direction of the eye is the Y axis, and the vertical direction is the vertical direction. The X axis is used. The + direction of each coordinate axis is as shown in the figure (the positive direction of the X axis is behind the paper surface). In the figure, 1 is a two-dimensional display element,
2 is anamorphic-aspherical surface (toric-
An aspherical surface) reflecting mirror 3 is an eyeball iris position or an eyeball turning point of an observer. In addition, the central axis of the reflecting mirror 2 is set to 2a.
And The eccentric amount of the vertex of the reflecting mirror 2 with respect to the optical axis passing through the origin is Y ₁ , the eccentric amount of the center of the two-dimensional display element 1 with respect to the optical axis passing through the origin is Y ₂ , and the central axis 2a of the reflecting mirror 2 is with respect to the Z axis. The angle is α ₁ (counterclockwise is positive), and the angle formed by the surface in contact with the center of the two-dimensional display element 1 with respect to the Y axis is α ₂ (counterclockwise is positive).

The constituent parameters of this optical system are shown below, and the surface number is shown as the surface number for the backward tracking from the iris position 3 toward the two-dimensional display element 1. As for the aspherical shape, the coordinate system is set as shown, and the paraxial radius of curvature of the reflecting mirror 2 is
When the vertical direction (XZ plane) is _Rx and the horizontal direction (YZ plane) is _Ry , it is represented by the following formula. ^{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 ] Here, K _x is the conical coefficient in the X direction, and K _y is the conical coefficient in the Y direction.

Surface Number Curvature Radius Surface Spacing (Distance from One Surface in Z Direction) Amount of Eccentricity / Declination 1 Iris Position (3) 2 R _x -120.212 (2) 49.639 Y ₁ -45.937 R _y -78.406 α ₁ -0.276 ° (aspherical surface) 3 ∞ (two-dimensional display element) (1) 15.000 Y ₂ -30.000 α ₂ 7.532 ° aspherical surface coefficient K _y = 1.376883 K _x = 0.555651 Note that θ in FIG. 3 is the bending angle of the optical axis, which is 50 ° in the case of the present embodiment.

Transverse aberration diagrams for this example are shown in FIGS. In FIG. 4, (a) is a horizontal right 15 for the observer.
Lateral aberration when performing reverse tracking from the observer's eyeball position 3 to the two-dimensional display element 1 in the horizontal direction and the vertical direction when observing the ° direction, and the unit is 1 mm. (B) shows the same lateral aberration in the left-right direction and the up-down direction when observing the front in the horizontal direction, and (c) shows the same lateral aberration in the left-right direction and the up-down direction when observing the left 15 ° direction in the horizontal direction. Lateral aberration.
Further, FIG. 5A shows the case where the observer performs the reverse tracking from the observer eyeball position 3 to the two-dimensional display element 1 in the left-right direction and the up-down direction when observing the upper right direction of 15 °. (B) is the same lateral aberration in the left-right direction and the vertical direction when observing the upper part in the upper 10 ° direction, and (c) is observing the upper left 15 ° direction in the upper 10 ° direction. It is the same lateral aberration in the left-right direction and the up-down direction.

Example 2 FIG. 6 shows a cross section in the Y-axis direction of the optical system of Example 2. This embodiment is basically the same as the first embodiment. Explaining only different parts, 2 is a spheroid. Hereinafter, the same parameters as in Example 1 are used to indicate the constituent parameters of this optical system. The aspherical shape is expressed by the following equation, where R is the paraxial radius of curvature of the reflecting mirror 2 with the coordinate system as shown in the figure. Z = (h ² / R) / [1+ {1- (1 + K) (h ² / R ² )} ^1/2 ] (h ² = X ² + Y ² ) where K is the conic coefficient ..

Surface number Radius of curvature Surface spacing (distance in Z direction from one surface) Decentering amount / angle 1 Iris position (3) 2 R −62.870 (2) 18.070 Y ₁ 27.406 (aspherical surface) α ₁ 54.261 ° 3 ∞ (two-dimensional display element) (1) 15.000 Y ₂ -30.000 α ₂ 8.561 ° Aspherical coefficient K = −0.756116 Note that the optical axis of FIG. The bending angle θ is 50 °. Transverse aberration diagrams of this example similar to FIGS. 4 and 5 are shown in FIGS.

Example 3 FIG. 9 shows a cross section in the Y-axis direction of the optical system of Example 3. This embodiment is basically the same as the first embodiment. Explaining only the different part, 2 is an anamorphic-aspherical surface reflecting mirror. Hereinafter, the same parameters as in Example 1 are used to indicate the constituent parameters of this optical system.

Surface number Radius of curvature Surface spacing (distance in the Z direction from one surface) Decentering amount / declination 1 Iris position (3) 2 R _x −76.950 (2) 37.289 Y ₁ −74.460 R _y -58.037 α ₁ -30.479 ° (aspherical surface) 3 ∞ (two-dimensional display element) (1) 15.000 Y ₂ -30.000 α ₂ 29.909 ° aspherical surface coefficient K _y = -0. 098541 K _x = −0.687091 The bending angle θ of the optical axis in FIG. 9 is 50 °. Transverse aberration diagrams of this example similar to FIGS. 4 and 5 are shown in FIGS.

Example 4 FIG. 12 shows a cross section in the Y-axis direction of the optical system of Example 4. This embodiment is basically the same as the first embodiment. Hereinafter, the same parameters as in Example 1 are used to indicate the constituent parameters of this optical system.

Surface Number Curvature Radius Surface Spacing (Distance from One Surface in Z Direction) Amount of Eccentricity / Declination 1 Iris Position (3) 2 R _x −56.206 (2) 42.723 Y ₁ −6.508 R _y -45.263 α ₁ 17.822 ° (aspherical surface) 3 ∞ (two-dimensional display element) (1) 24.000 Y ₂ -19.274 α ₂ 8.121 ° aspherical surface coefficient K _y = 0.861207 K _x = 0.599629 Note that the bending angle θ of the optical axis in FIG. 12 is 50 °. Transverse aberration diagrams similar to FIGS. 4 and 5 of this embodiment are shown in FIGS.
Shown in.

Example 5 FIG. 15 shows a cross section in the Y-axis direction of the optical system of Example 5. This embodiment is basically the same as the first embodiment. Hereinafter, the same parameters as in Example 1 are used to indicate the constituent parameters of this optical system.

Surface number Radius of curvature Surface spacing (distance from one surface in Z direction) Decentering amount / angle 1 Iris position (3) 2 R _x −67.670 (2) 43.744 Y ₁ −17.561 R _y -56.313 α ₁ 4.298 ° (aspherical surface) 3 ∞ (two-dimensional display element) (1) 17.500 Y ₂ -18.880 α ₂ 1.078 ° aspherical surface coefficient K _y = 0.812721 K _x = 0.656341 The bending angle θ of the optical axis in FIG. 15 is 40 °. Transverse aberration diagrams similar to FIGS. 4 and 5 of this embodiment are shown in FIGS.
Shown in.

In each of the above embodiments, the eyepiece optical system 2 can be a semitransparent mirror other than the concave mirror. It is a well known fact that a semi-transparent mirror can be combined with an external image. In addition, it is a well-known fact that the expression of the aspherical shape in each of the embodiments is performed for the sake of convenience, and can be modified by the difference in the description formula.

Although the visual display device of the present invention has been described with reference to some embodiments, the present invention is not limited to these embodiments and various modifications can be made.

[0031]

As is apparent from the above description, according to the visual display device of the present invention, a portable head or face capable of obtaining a high resolution for a wide angle of view by using a flat two-dimensional image display device. A wearable visual display device can be provided.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the operation of a visual display device of the present invention.

FIG. 2 is a diagram for explaining a relationship between a reflection position and a curvature of a reflecting mirror according to the present invention.

FIG. 3 is a sectional view of the optical system of Example 1.

FIG. 4 is a lateral aberration diagram of Example 1 in the horizontal direction.

FIG. 5 is a lateral aberration diagram for Example 1 in the upper 10 ° direction.

FIG. 6 is a sectional view of an optical system according to a second embodiment.

FIG. 7 is a lateral aberration diagram of Example 2 in the horizontal direction.

FIG. 8 is a lateral aberration diagram for the upper 10 ° direction of Example 2;

FIG. 9 is a sectional view of an optical system according to a third embodiment.

10 is a lateral aberration diagram for Example 3 in the horizontal direction. FIG.

FIG. 11 is a lateral aberration diagram for the upper 10 ° direction of Example 3;

FIG. 12 is a sectional view of an optical system of Example 4.

FIG. 13 is a lateral aberration diagram in the horizontal direction of Example 4.

FIG. 14 is a lateral aberration diagram for Example 4 in the upward 10 ° direction.

FIG. 15 is a sectional view of an optical system according to Example 5.

16 is a horizontal aberration diagram for Example 5 in the horizontal direction. FIG.

FIG. 17 is a lateral aberration diagram for Example 5 in the upward 10 ° direction.

FIG. 18 is a plan view of a conventional face-mounted visual display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Two-dimensional display element (aerial image of two-dimensional display element) 2 ... Eyepiece optical system (reflecting mirror) 3 ... Observer center of eyeball rotation (center of iris) 5 ... Luminous flux corresponding to left visual field 6 ... Front visual field Luminous flux 7 ... luminous flux 2a corresponding to the right field of view 2a ... central axis of the reflecting mirror

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[Procedure amendment]

[Submission date] July 29, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

In this case, the bending angle of the optical axis formed by the incident optical axis and the outgoing optical axis to the eyepiece optical system is preferably 20 ° or more, and the optical axis is seen from the two-dimensional display element of the eyepiece optical system. It is desirable that the radius of curvature in the bending direction be in the range of 50 to 200 mm.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

Further, the two-dimensional display element 1 of the eyepiece optical system 2
The radius of curvature in the direction in which the optical axis bends is 50 to 20
It is desirable to set it to 0 mm, and if it exceeds the lower limit, the distance between the observer's eyeball position 3 and the eyepiece optical system 2 becomes too short, and when the observer wears this visual display device, the observer feels a feeling of pressure and is wide. The angle of view cannot be secured. on the other hand,
If the upper limit is exceeded, the observer's eyeball position 3 and the eyepiece optical system 2
And the projection amount of the eyepiece optical system 2 from this visual display device increases, and the wearing feeling when the present visual display device is worn deteriorates.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0019

[Correction method] Change

[Correction content]

Surface number Radius of curvature Surface spacing (distance in the Z direction from one surface) Decentering amount / angle 1 Iris position (3) 2 R _x −78.406 (2) 49.639 Y ₁ −45.937 R _y −120.212 α ₁ −0.276 ° (aspherical surface) 3 ∞ (two-dimensional display element) (1) 15.000 Y ₂ −30.000 α ₂ 7.532 ° aspherical surface coefficient K _y = 1.376883 K _x = 0.555651 Note that θ in FIG. 3 is the bending angle of the optical axis, which is 50 ° in the case of the present embodiment.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction content]

Surface Number Curvature Radius Surface Spacing (Distance from One Surface in Z Direction) Eccentricity / Declination 1 Iris Position (3) 2 R _x −58.037 (2) 37.289 Y ₁ −74.460 R _y -76.950 α ₁ -30.479 ° (aspherical surface) 3 ∞ (two-dimensional display element) (1) 15.000 Y ₂ -30.000 α ₂ 29.909 ° aspherical surface coefficient K _y = -0. 098541 K _x = −0.687091 The bending angle θ of the optical axis in FIG. 9 is 50 °. Transverse aberration diagrams of this example similar to FIGS. 4 and 5 are shown in FIGS.

[Procedure Amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

Surface number Radius of curvature Surface spacing (distance from one surface in Z direction) Decentering amount / angle 1 Iris position (3) 2 R _x −45.263 (2) 42.723 Y ₁ −6.508 R _y -56.206 α ₁ 17.822 ° (aspherical surface) 3 ∞ (two-dimensional display element) (1) 24.000 Y ₂ -19.274 α ₂ 8.121 ° aspherical surface coefficient K _y = 0.861207 K _x = 0.599629 Note that the bending angle θ of the optical axis in FIG. 12 is 50 °. Transverse aberration diagrams similar to FIGS. 4 and 5 of this embodiment are shown in FIGS.
Shown in.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

Surface number Radius of curvature Surface spacing (distance from one surface in Z direction) Decentering amount / angle 1 Iris position (3) 2 R _x −56.313 (2) 43.744 Y ₁ −17.561 R _y -67.670 α ₁ 4.298 ° (aspherical surface) 3 ∞ (two-dimensional display element) (1) 17.500 Y ₂ -18.880 α ₂ 1.078 ° aspherical surface coefficient K _y = 0.812721 K _x = 0.656341 The bending angle θ of the optical axis in FIG. 15 is 40 °. Transverse aberration diagrams similar to FIGS. 4 and 5 of this embodiment are shown in FIGS.
Shown in.

Claims (3)

[Claims] 1. An eyepiece optic comprising a two-dimensional display element for displaying an observation image and a reflecting surface or a semi-transmissive reflecting surface for magnifying and projecting the two-dimensional display element or its projected image in the air and bending the optical axis. In a visual display device comprising a system and supporting means for supporting the eyepiece optical system so as to be positioned immediately in front of a user's eyeball, a curvature of the eyepiece optical system in a plane in which an optical axis of the visual display device is bent. Is configured to be higher on the side farther from the position where the optical axis is bent when viewed from the two-dimensional display element. 2. The visual display device according to claim 1, wherein a bending angle of an optical axis formed by an incident optical axis and an outgoing optical axis to the eyepiece optical system is 20 ° or more. 3. The focal length of the eyepiece optical system is 50 to 20.
The visual display device according to claim 3, wherein the visual display device is in a range of 0 mm.