Image display device

Abstract

To reduce chromaticity shift and reduction in the brightness of a peripheral area in an image display device that is thin and has a wide angle of view.SOLUTION: An image display device 101 has a display optical system for the right eye 104 that guides image light from a display element for the right eye 106 to the right eye of an observer, and a display optical system for the left eye 105 that guides image light from a display element for the left eye 107 to the left eye of the observer. The display element for the right eye and the display element for the left eye each have an element that is at least one of a color filter and a micro lens provided in correspondence with every pixel. An intersection of an optical axis of the display optical system for the right eye and a display surface of the display element for the right eye, and an intersection of an optical axis of the display optical system for the left eye and a display surface of the display element for the left eye, are each shifted relative to the center of the display surface. In each of the display element for the right eye and the display element for the left eye, the amount of shift of the element corresponding to the pixel toward a periphery relative to the center of the pixel, is smaller in an intersection area including the intersection than in a peripheral area closer to the periphery than the intersection area.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an image display device such as a head mounted display (HMD) that guides light from a display element to a viewer's eyes to enable magnified observation of an image. [Background technology]

[0002] Some of the image display devices as described above enable wide-angle image observation by displaying images with different angles of view to the left and right eyes of an observer. In the image display device disclosed in Patent Document 1, an optical system in which the outer angle of view is wider than the inner angle of view is inverted between the left and right, thereby displaying images with different angles of view to the left and right eyes. In the image display device disclosed in Patent Document 2, the display centers of the display elements for the left and right eyes are shifted left and right, respectively, and the images displayed on each display element are also shifted left and right as viewed from the observer, thereby displaying images with different angles of view to the left and right eyes.

[0003] When the focal length of the optical system is shortened to widen the angle of view and reduce the thickness of these image display devices, the angle of emission of light from the peripheral area of ​​the display element becomes large, and the image is prone to have a decrease in brightness and chromaticity deviation, which makes it impossible for a viewer to view a bright image with correct colors when viewing the peripheral area. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-242794 A [Patent Document 2] Japanese Patent Application Publication No. 6-38246 Summary of the Invention [Problem to be solved by the invention]

[0005] However, Patent Documents 1 and 2 make no mention of a method for reducing chromaticity deviation in the peripheral region of a display element.

[0006] The present invention provides an image display device that has a wide angle of view and is thin, yet is capable of reducing the decrease in luminance of light from the peripheral area of ​​a display element and chromaticity deviation. [Means for solving the problem]

[0007] An image display device according to one aspect of the present invention includes a right-eye display element and a left-eye display element each having a plurality of pixels on a display surface, and a right-eye display optical system for directing image light emitted from the right-eye display element to the right eye of an observer, and a left-eye display optical system for directing image light emitted from the left-eye display element to the left eye of the observer. Each of the right-eye and left-eye display elements has at least one of a color filter and a microlens provided corresponding to each pixel in the plurality of pixels. An intersection between an optical axis of the right-eye display optical system and a display surface of the right-eye display element, and an intersection between an optical axis of the left-eye display optical system and a display surface of the left-eye display element are each shifted with respect to the center of the display surface. In each of the right-eye and left-eye display elements, the amount of shift of the center of the element corresponding to the pixel toward the periphery is greater in a peripheral region on the peripheral side of the intersection region than in an intersection region including the intersection. Effect of the Invention

[0008] According to the present invention, in a wide-angle, thin image display device, it is possible to reduce the decrease in luminance and chromaticity deviation of light from the peripheral area of ​​a display element. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a configuration of an image display device according to a first embodiment. [Diagram 2] FIG. 2 is a diagram for explaining a display optical system in the first embodiment. [Diagram 3] FIG. 1 is an external view of an image display device according to a first embodiment. [Figure 4] FIG. 4 is a graph showing the viewing angle characteristics of the display element in the first embodiment. [Diagram 5] FIG. 2 is a diagram for explaining a color filter in the first embodiment. [Figure 6] 4 is a diagram showing the viewing angle characteristics at the horizontal end of the display element in Example 1. FIG. [Figure 7] 4 is a diagram showing the relationship between the display angle of view and the emission angle from a display element in the first embodiment. [Figure 8] FIG. 2 is a diagram for explaining a color filter in the first embodiment. [Figure 9] FIG. 11 is a diagram showing the configuration of an image display device according to a second embodiment. [Figure 10] FIG. 11 is a diagram showing a detailed configuration of a display optical system in the second embodiment. [Figure 11] FIG. 11 is a diagram showing a display optical system according to a second embodiment. [Figure 12] FIG. 11 is a diagram for explaining a color filter according to the second embodiment. [Figure 13] 13 is a graph showing the viewing angle characteristics at the horizontal end of a display element in Example 2. FIG. [Figure 14] FIG. 11 is a diagram showing a ghost light path of a display optical system in the second embodiment. [Figure 15] FIG. 11 is a diagram showing the position of a gate in a display optical system according to the second embodiment. [Figure 16] 4A to 4C are diagrams showing an example in which the pixel pitch of a display element and the pitch of a color filter are different in the first embodiment. [Figure 17] 4A and 4B are diagrams showing an example in which the pitch of color filters is different between a binocular region and a monocular region in the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. EXAMPLES

[0011] FIG. 1 shows the configuration of an HMD 101 as an image display device of the first embodiment. Reference numeral 102 denotes the right eye of an observer, and 103 denotes the left eye of the observer. A right-eye lens 104 constitutes a right-eye display optical system, and a left-eye lens 105 constitutes a left-eye display optical system. Reference numeral 106 denotes a right-eye display element, and 107 denotes a left-eye display element. Each display element is composed of an organic EL display, a liquid crystal display element, a digital micromirror device, or the like. Reference numeral 108 denotes the optical axis of the right-eye display optical system, and 109 denotes the optical axis of the left-eye display optical system. The directions in which the optical axes 108 and 109 extend are called the optical axis directions of the right-eye display optical system and the left-eye display optical system, respectively. Reference numeral 110 denotes the center of the display surface of the right-eye display element 106, and 111 denotes the center of the display surface of the left-eye display element 107.

[0012] The right-eye display optical system guides image light from the right-eye display element 106 to the right eye 102 of the observer so that the observer can observe an enlarged virtual image of the original image displayed on the right-eye display element 106 as a display image. The left-eye display optical system guides image light from the left-eye display element 107 to the left eye 103 of the observer so that the observer can observe an enlarged virtual image of the original image displayed on the left-eye display element 107 as a display image.

[0013] The focal length F1 of the right eye display optical system and the left eye display optical system is 15 mm, and the size of the right eye display element 106 and the left eye display element 107 is 0.8 inches. The eye relief E1, which is the distance between the HMD 101 and the observer's eyes (102, 103), is 15 mm. The HMD 101 is a head-mounted image display device, and it is desirable that the eye relief is 15 mm or more so that an observer who wears glasses can wear it. However, if the eye relief is too long, the outer shape of each display optical system becomes large and the HMD 101 also becomes large, so it is desirable that the eye relief is 25 mm or less. The exit pupil of each display optical system is set at a position of 25 mm, which is the eye relief of 15 mm plus the rotation radius of the eyeball of 10 mm, and the exit pupil diameter is set to 6 mm. With such a setting, even when the eyeball rotates to observe up, down, left, or right, light in that direction enters the eyeball.

[0014] The center 110 of the right eye display element 106 is shifted to the right with respect to a vertical cross section (a cross section perpendicular to the plane of the paper in FIG. 1) including the optical axis 108 of the right eye display optical system. The horizontal display angle of view in the left-right direction of the right eye display optical system is 40° to the right and 20° to the left. The center 111 of the left eye display element 107 is shifted to the left with respect to a vertical cross section including the optical axis 109 of the left eye display optical system. The horizontal display angle of view in the left-right direction of the left eye display optical system is 20° to the right and 40° to the left. In other words, the right eye display optical system and the left eye display optical system have different display angles of view to the left and right with respect to the optical axis.

[0015] Therefore, when the observer observes with both eyes (102, 103), the display angle of view from 40° to 20° on the right side is observed only by the right eye 102, and the display angle of view from 20° to 20° on the right side is observed with both eyes. Also, the display angle of view from 20° to 40° on the left side is observed only by the left eye 103. That is, the overall horizontal angle of view is 80°. In this way, in this embodiment, images with different display angles are displayed to the right eye 102 and the left eye 103, and parts of these display angles are superimposed and displayed to both eyes. As a result, when the display elements 106 and 107 for the right and left eyes are the same size, it is possible to observe images with a wider angle of view than when images with the same display angle are displayed to the right eye 102 and the left eye 103. The vertical display angle of view of each display optical system is 40°. In the following description, a display angle of view observed by each of the right and left eyes alone is referred to as a monocular region, and a display angle of view observed by both eyes is referred to as a binocular region.

[0016] When displaying images with different display angles for the right and left eyes as described above and widening the angle of view by displaying a portion of the display angles (binocular area) to both eyes, it is desirable that the display angle of view displayed to both eyes is 40° or more. If the display angle of view displayed to both eyes is smaller than 40°, the range that the viewer can observe stereoscopically becomes narrow, and it becomes impossible to observe a natural image, which is not preferable.

[0017] In the case of the display optical system (lenses 104 and 105) of this embodiment, which has a long eye relief, a short focal length, and a thin shape, the emission angle of the image light from the peripheral area (peripheral angle of view) of the display element becomes large. If the emission angle from the display element is large, the viewing angle characteristics deteriorate (the brightness decreases and the chromaticity shift in the peripheral area becomes large).

[0018] In the display optical system of this embodiment, as shown in Fig. 1, when the observer is looking straight ahead, the exit angle of the chief ray from the display elements 106 and 107 at the maximum horizontal peripheral angle of view of 40° is 35°, and the exit angle of the chief ray at a field angle of 20° is 10°. The chief ray is a light ray that passes through the center of the exit pupil of the display optical system. As shown in Fig. 2, when the observer is looking at the horizontal end of the display element 106, the exit angle of the chief ray from the display element 106 at the maximum horizontal peripheral angle of view of 40° is 55°, and the exit angle of the chief ray at a field angle of 20° is 30°.

[0019] The luminance (brightness) and chromaticity shift (ΔE) of a normal display element under these conditions are as shown in Figure 4(a) and (b), respectively. As the output angle from the display element increases, the luminance decreases and the chromaticity shift increases.

[0020] Therefore, in this embodiment, the pitch of the pixels of the display element and the pitch of the color filters (the pitch between the dispersing elements) as dispersing elements provided for each pixel are changed with the intersection of the display surface of the display element and the optical axis of the display optical system as the center. As a result, the position of the center of the color filter relative to the center of the pixel is shifted in the peripheral region of the display element. That is, in the peripheral region of the display element, the color filter is shifted relative to the pixel in the direction of the emission angle of the image light. This can improve the viewing angle characteristics. At that time, in the peripheral region, the image light is emitted outward with respect to the optical axis of the display optical system, so the pitch of the color filter is made larger than the pitch of the pixels. That is, the angle (shift amount) by which the center of the color filter is shifted outward as the peripheral side with respect to the center of the pixel is made larger in the peripheral region on the peripheral side of the intersection region than in the intersection region where the intersection of the display surface of the display element and the optical axis of the display optical system is located.

[0021] 5(a) to (c) show the positional relationship between the red, green and sub-pixels and the red, green and blue color filters provided on the display surface of the right-eye display element 106. Each color filter may be rectangular, square or hexagonal when viewed from the optical axis direction of the right-eye display optical system.

[0022] FIG. 5(a) shows the above positional relationship at the intersection between the display surface of the right-eye display element 106 and the optical axis 108 of the right-eye display optical system. At the intersection (including the intersection area), the centers of the red, green, and blue color filters 118, 119, and 120 coincide with the centers of the red, green, and sub-pixels 115, 116, and 117, respectively, as in a normal display element. FIG. 5(b) shows the above positional relationship at the left end of the display surface of the right-eye display element 106 as seen by the observer. At the left end, the centers of the red, green, and blue color filters 124, 125, and 126 are shifted outward (to the left eye side) by 15° with respect to the centers of the red, green, and sub-pixels 121, 122, and 123, respectively. FIG. 5(c) shows the above positional relationship at the right end of the display surface of the right-eye display element 106 as seen by the observer. At the right end, the centers of the red, green and blue color filters 130, 131 and 132 are shifted outward (opposite the left eye side) by 35° relative to the centers of the red, green and sub-pixels 127, 128 and 129, respectively.

[0023] Fig. 16(a) shows the arrangement of pixels (red, green, and blue sub-pixels are collectively shown as one pixel) on a display element when viewed from the optical axis direction of the display optical system. Fig. 16(b) shows the arrangement of color filters when viewed from the optical axis direction. Reference numeral 133 denotes the intersection point between the display surface of the display element and the optical axis of the display optical system. As shown in Fig. 16(b), the size of the color filters remains the same, but the pitch of the color filters, i.e., the shift amount relative to the pixels, is increased from the intersection point 133 to the peripheral region (and further from the portion of the peripheral region on the intersection side to the portion on the peripheral side).

[0024] In the case where the center of the display surface of the display element is shifted with respect to the optical axis of the display optical system as in this embodiment, the point where the chief ray is emitted in the normal direction from the display element is not the center of the display surface but the intersection point between the display surface and the optical axis of the display optical system. Therefore, by aligning the center of the pixel with the center of the color filter at the intersection point, the viewing angle characteristics can be improved.

[0025] 6(a), the viewing angle characteristic indicating the luminance at the left end of the right-eye display element 106 is the brightest (highest luminance) in the -15° direction. Similarly, the viewing angle characteristic indicating the chromaticity shift is the highest (smallest chromaticity shift) in the -15° direction.

[0026] The emission angle of the chief ray from the left end of the right eye display element 106 to the right eye display optical system is -10° when the observer is looking straight ahead, and -30° when looking at the left end. Note that the sign of the emission angle is set to 0°, with the normal direction of the right eye display element 106 being positive when viewed from the observer, and negative to the left.

[0027] At the left end of the display image when the observer is looking straight ahead, if the color filter is not shifted relative to the pixel, the brightness decreases by 3%, and ΔE is 1, as shown at -10° in Figs. 4(a) and 4(b), respectively. In contrast, if the color filter is shifted relative to the pixel, the brightness is improved to only decrease by 1%, as shown at -10° in Fig. 6(a), and ΔE remains unchanged, although not shown. Furthermore, at the left end of the display image when the observer is looking at the left end, if the color filter is not shifted relative to the pixel, the brightness is reduced by 25%, and ΔE is 8, as shown at -30° in Figs. 4(a) and 4(b). In contrast, if the color filter is shifted relative to the pixel, the brightness is improved to only decrease by 7%, as shown at -30° in Fig. 6(a), and ΔE is improved to 2, although not shown.

[0028] 6(b), the brightness characteristic at the right end of the right-eye display element 106 is the brightest at 35°. Similarly, the chromaticity shift characteristic at 35° is also the highest at 35°.

[0029] The angle of emergence of the chief ray from the right end of the right-eye display element 106 to the right-eye display optical system is 35° when the observer is looking straight ahead, and 55° when looking to the right end.

[0030] At the right edge of the displayed image when the observer is looking straight ahead, if the color filter is not shifted relative to the image, the brightness decreases by 33%, and ΔE is 11, as shown at 35° in Figs. 4(a) and (b), respectively. In contrast, if the color filter is shifted relative to the image, the brightness does not decrease, as shown at 35° in Fig. 6(b), and ΔE does not increase, although not shown. Furthermore, at the right edge of the displayed image when the observer is looking at the right edge, if the color filter is not shifted relative to the pixel, the brightness decreases by 67%, and ΔE is 22, as shown at 55° in Figs. 4(a) and (b). In contrast, if the color filter is shifted relative to the pixel, the brightness decreases by only 12%, as shown at 55° in Fig. 6(b), and ΔE improves to 4, although not shown.

[0031] So far, the shift of the color filter at the left and right ends in the horizontal direction of the display element has been described, but the same applies to the top and bottom ends in the vertical direction. In the display optical system of this embodiment, when the observer is looking straight ahead, the exit angle of the chief ray from the display element at the maximum vertical peripheral angle of view of 20° is 10°. Also, when the observer is looking at the end in the vertical direction, the exit angle of the chief ray from the display element at the maximum vertical peripheral angle of view of 20° is 30°.

[0032] At the upper end of the right eye display element 106 as viewed from the observer, the center of the red color filter is shifted 15° upward from the center of the red sub-pixel. At the lower end of the right eye display element 106, the center of the red color filter is shifted 15° downward from the center of the red sub-pixel. The same applies to the green and blue color filters.

[0033] By shifting the color filters relative to the pixels as described above, the brightness and chromaticity deviation at the upper and lower ends of the right-eye display element 106 is improved.

[0034] Fig. 7 shows the relationship between the display angle of view when the observer looks straight ahead in the right-eye display optical system and the emission angle of the chief ray from the right-eye display element 106 in this embodiment. As can be seen from Fig. 7, the emission angle of the chief ray from the right-eye display element 106 increases as the display angle of view increases. For this reason, it is necessary to increase the angle at which the color filter is shifted with respect to the pixels from the intersection of the display surface of the right-eye display element 106 and the optical axis of the right-eye display optical system to the peripheral area.

[0035] In this case, the shift amount of the color filter with respect to the pixel increases from the intersection of the display surface and the optical axis to the peripheral region, so the size of the color filter may be increased according to the shift amount. FIG. 8(a) shows the arrangement of pixels on the display element when viewed from the optical axis direction, as in FIG. 16(a). FIG. 8(b) shows the arrangement and size of the color filter when viewed from the optical axis direction. As in FIG. 16(b), 133 is the intersection of the display surface of the display element and the optical axis of the display optical system. As shown in FIG. 8(b), both the pitch and size of the color filter increase from the intersection 133 to the peripheral region. When the size of the color filter increases, the angle of the image light emitted from the sub-pixel and transmitted through the color filter increases, further improving the viewing angle characteristics.

[0036] It is desirable that the angle φ by which the color filter is shifted outward at a pixel A other than the intersection of the display surface of the display element and the optical axis of the display optical system (the tilt angle in a specific direction relative to the normal direction of the display surface) satisfies the condition of the following equation 1.

[0037] 0<φ≦θ1 (Equation 1) Here, θ1 is the emission angle from the display surface of the chief ray in the direction of the display angle of view corresponding to pixel A when the viewer is looking in that direction, and the direction toward the outside of the display surface is considered positive. In other words, when pixel A is located at the edge of the display surface, θ1 is the emission angle from the display surface of the chief ray that travels from the edge to the center of the exit pupil when the viewer's eyeball is facing the edge of the display surface.

[0038] In this embodiment, θ1 is 55° when the display angle of view is 40°, and θ1 is 30° when the display angle of view is 20°. The angle φ by which the color filter is shifted outward in each pixel satisfies the condition of formula 1.

[0039] When the angle at which the color filter is shifted outward is 0° or less, that is, when the viewing angle characteristic in the normal direction or the direction toward the inside of the display surface is good, the difference between the exit angle from the peripheral region of the display surface and the direction with good viewing angle characteristic is large. In this case, the brightness reduction and chromaticity shift in the peripheral region of the displayed image become large, which is not preferable because a natural image cannot be observed. In addition, when the angle at which the color filter is shifted outward is larger than θ1, the difference between the exit angle from the peripheral region of the display surface when the observer is looking straight ahead and the direction with good viewing angle characteristic is large. In this case, the brightness reduction and chromaticity shift in the peripheral region of the displayed image when the observer is looking straight ahead become large, which is not preferable because a natural image cannot be observed.

[0040] It is more desirable to satisfy the condition of the following formula 2.

[0041] θ2≦φ≦θ1 (Formula 2) Here, θ2 is the emission angle from the display element of the chief ray in the direction of the display angle of view corresponding to pixel A when the observer is looking straight ahead in the direction of the optical axis of the display optical system, and the direction toward the outside of the display surface is positive. In the case where pixel A is located at the edge of the display surface, θ2 is the emission angle from the display surface of the chief ray toward the center of the exit pupil from the edge of the display surface when the observer's eyeball is facing in the direction of the optical axis of the display optical system.

[0042] In this embodiment, θ2 is 35° when the display angle of view is 40°, and θ2 is 10° when the display angle of view is 20°. The angle φ by which the color filter is shifted outward in each pixel satisfies the condition of formula 2.

[0043] When the maximum display angle of view is 40° as in this embodiment, the viewer can recognize the image of the peripheral area while looking straight ahead, so it is preferable to determine the angle at which the color filter is shifted outward assuming that the viewer is looking straight ahead.

[0044] As can be seen from FIG. 7, the increase in the output angle from the display element differs between the binocular region with a display angle of view of 0° to 20° and the monocular region with a display angle of view of 20° to 40°, and the increase rate of the output angle in the monocular region is greater than that in the binocular region. Therefore, the pitch of the color filter in the monocular region relative to the binocular region may be changed in accordance with the difference in the increase rate of the output angle. In this case, as shown in FIG. 17, the viewing angle characteristics can be improved according to the output angle of each of the monocular region and the binocular region by making the pitch of the color filter in the monocular region larger than the pitch of the color filter in the binocular region (i.e., the shift amount for the pixel).

[0045] Fig. 13 shows the appearance of the HMD 101. Since the HMD 101 is a head-mounted image display device, it is desirable that it be lightweight. For this reason, it is desirable that the lenses 104 and 105 that constitute the display optical system are made of resin, which has a lower specific gravity than glass. Furthermore, it is desirable that the resin lenses 104 and 105 each have aspheric surfaces on both sides to enhance the aberration correction effect.

[0046] In this embodiment, the right-eye and left-eye display optical systems are each constructed with a single lens (104, 105), but each display optical system may be constructed using multiple lenses to obtain higher optical performance. EXAMPLES

[0047] FIG. 9 shows the configuration of an HMD 201 of the second embodiment. Reference numeral 202 denotes the right eye of an observer, and 203 denotes the left eye of the observer. A cemented lens formed by cementing lenses 204 and 205 constitutes a right-eye display optical system. A cemented lens formed by cementing lenses 206 and 207 constitutes a left-eye display optical system. Reference numeral 208 denotes a right-eye display element, and 209 denotes a left-eye display element. Each display element is an organic EL display. Reference numeral 210 denotes the optical axis of the right-eye display optical system, and 211 denotes the optical axis of the left-eye display optical system. Reference numeral 212 denotes the center of the display surface of the right-eye display element 208, and 213 denotes the center of the display surface of the left-eye display element 209.

[0048] The right-eye display optical system guides image light from the right-eye display element 208 to the right eye 202 of the observer so that the observer can observe an enlarged virtual image of the original image displayed on the right-eye display element 208 as a display image. The left-eye display optical system guides image light from the left-eye display element 209 to the left eye 203 of the observer so that the observer can observe an enlarged virtual image of the original image displayed on the left-eye display element 209 as a display image.

[0049] The focal length F2 of the right eye display optical system and the left eye display optical system is 13 mm, and the size of the right eye display element 208 and the left eye display element 209 is 1 inch. The eye relief E2 of the HMD 201 is 20 mm.

[0050] The exit pupil of each display optical system is set at 30 mm, which is the sum of the eyeball rotation radius of 10 mm and the eye relief of 20 mm, and the exit pupil diameter is set to 6 mm. With this setting, even when the eyeball rotates to observe up, down, left, or right, the image light in that direction enters the eyeball.

[0051] The center 212 of the right eye display element 208 is shifted to the right with respect to a vertical cross section including an optical axis 210 of the right eye display optical system. The horizontal display angle of view of the right eye display optical system is 50° to the right and 30° to the left. The center 213 of the left eye display element 209 is shifted to the left with respect to a vertical cross section including an optical axis 211 of the left eye display optical system. The horizontal display angle of view of the left eye display optical system is 30° to the right and 50° to the left. In other words, the right eye display optical system and the left eye display optical system have different display angles of view to the left and right with respect to the optical axis.

[0052] Therefore, when the observer observes with both eyes (202, 203), the display angle of view (monocular region) from 50° to the right to 30° to the right is observed only by the right eye 102, and the display angle of view (binocular region) from 30° to the right to 30° to the left is observed with both eyes. Also, the display angle of view (monocular region) from 30° to 50° to the left is observed only by the left eye 203. That is, the entire horizontal display angle of view is 100°. Thus, in this embodiment, images with different display angles of view are displayed to the right eye 202 and the left eye 203, and parts of the display angles are superimposed and displayed to both eyes. As a result, when the display elements 208 and 209 for the right and left eyes are the same in size, it is possible to observe images with a wider angle of view than when images with the same display angle of view are displayed to the right eye 202 and the left eye 203. The vertical display angle of view of each display optical system is 60°.

[0053] As in the first embodiment, when images with different display angles are displayed for the right and left eyes and a part of the display angles (binocular regions) is displayed for both eyes to widen the angle of view, the display angle of view displayed for both eyes is preferably 40° or more, and more preferably 50° or more. If the display angle of view displayed for both eyes is 50° or more, the range that can be observed stereoscopically is wide, and a more natural image can be observed.

[0054] The display optical system of this embodiment is configured to fold the optical path by using polarized light. The configuration will be described with reference to FIG. 10, taking the display optical system for the right eye as an example. As shown in FIG. 10, a polarizing plate 250 and a first phase plate 251 are arranged between the display element 208 for the right eye and the lens 205 in this order from the display element side to the observation side (eyeball side). In addition, a half mirror 252 as a semi-transmissive reflective surface is formed by deposition on the joint surface of the lens 204 with the lens 205. Furthermore, a second phase plate 253 and a PBS 254 as a polarization separation element are arranged between the lens 204 and the right eye 202 in this order from the display element side. The second phase plate 253 and the PBS 254 are formed in a planar shape. The first phase plate 251 and the second phase plate 253 are λ / 4 plates.

[0055] The slow axis of the first phase plate 251 is inclined at 45° and the slow axis of the second phase plate 253 is inclined at −45° with respect to the polarization direction of the linearly polarized light passing through the polarizing plate 250. The polarization direction of the linearly polarized light passing through the polarizing plate 250 and the polarization direction of the linearly polarized light passing through the PBS 254 are perpendicular to each other.

[0056] In this configuration, unpolarized light emitted from the right-eye display element 208 passes through the polarizing plate 250 and becomes linearly polarized light, and this linearly polarized light passes through the first phase plate 251 and is converted to circularly polarized light. The circularly polarized light passes through the half mirror 252 and then through the second phase plate 253 to be converted to linearly polarized light. Since the polarization direction of this linearly polarized light is orthogonal to the polarization direction passing through the PBS 254, it is reflected by the PBS 254, passes through the second phase plate 253 and is converted to circularly polarized light.

[0057] This circularly polarized light is then reflected by the half mirror 252, and passes through the second phase plate 253 to be converted into linearly polarized light. Since the polarization direction of this linearly polarized light matches the polarization direction of light passing through the PBS 254, it passes through the PBS 254 and is guided to the right eye 202. In order to reduce ghost light generated by external light entering the display optical system and to increase the contrast of the displayed image, a polarizing plate may be disposed between the PBS 254 and the right eye 202. The above configuration and optical path are the same for the left-eye display optical system.

[0058] By folding the optical path using polarized light as in this embodiment, the display optical system can be made thinner and the focal length can be shortened, making it possible to observe images with a wide angle of view.

[0059] Since the HMD 201 is a head-mounted image display device, it is desirable that it be lightweight. For this reason, it is desirable that the lenses constituting the display optical system are made of resin, which has a smaller specific gravity than glass. In this embodiment, the lenses 204, 205, 206, and 207 are made of resin and aspherical lenses to enhance the aberration correction effect.

[0060] In the display optical system of this embodiment, as in the first embodiment, the emission angle of the image light from the peripheral region of the display element is large, so that degradation of the viewing angle characteristics (degradation of luminance and increase of chromaticity deviation) occurs.

[0061] In the display optical system of this embodiment, when the observer is looking straight ahead, as shown in Fig. 9, the exit angle of the chief ray from the display element at the maximum horizontal peripheral angle of view of 50° is 40°, and the exit angle of the chief ray at a field angle of 30° is 20°. Also, when the observer is looking at the horizontal end, as shown in Fig. 11, the exit angle of the chief ray from the display element at the maximum horizontal peripheral angle of view of 50° is 60°, and the exit angle of the chief ray at a field angle of 30° is 45°.

[0062] In this case, the viewing angle characteristics of luminance (brightness) and chromaticity shift (ΔE) of a normal display element are as shown in Figure 4. As the emission angle from the display element increases, the luminance decreases and the chromaticity shift increases.

[0063] Therefore, in this embodiment, the pitch of the pixels of the display element and the pitch of the color filters provided for each pixel are changed around the intersection of the display surface of the display element and the optical axis of the display optical system, thereby shifting the positions of the color filters relative to the pixels in the peripheral region of the display element. This makes it possible to improve the viewing angle characteristics. In this case, in the peripheral region, the image light is emitted outward with respect to the optical axis of the display optical system, so the pitch of the color filters is made larger than the pitch of the pixels.

[0064] 12(a) to (c) show the positional relationship between the red, green and sub-pixels and the red, green and blue color filters provided on the display surface of the right-eye display element 208. Each color filter may be rectangular, square or hexagonal when viewed from the optical axis direction of the right-eye display optical system.

[0065] FIG. 12(a) shows the above positional relationship at the intersection between the display surface of the right-eye display element 206 and the optical axis 210 of the right-eye display optical system. At the intersection (including the intersection area), the centers of the red, green, and blue color filters 218, 219, and 220 coincide with the centers of the red, green, and sub-pixels 215, 216, and 217, respectively, as in a normal display element. FIG. 12(b) shows the above positional relationship at the left end of the display surface of the right-eye display element 208 as seen by the observer. At the left end, the centers of the red, green, and blue color filters 224, 225, and 226 are shifted outward (to the left eye side) by 27° with respect to the centers of the red, green, and sub-pixels 221, 222, and 223, respectively. FIG. 12(c) shows the above positional relationship at the right end of the display surface of the right-eye display element 208 as seen by the observer. At the right end, the centers of the red, green and blue color filters 230, 231 and 232 are shifted outward (opposite the left eye side) by 55° relative to the centers of the red, green and sub-pixels 227, 228 and 229, respectively.

[0066] In this embodiment as well, the arrangement of color filters relative to the arrangement of pixels on the display element when viewed from the optical axis direction shown in FIG. 16(a) is as shown in FIG. 16(b).

[0067] In this case, the viewing angle characteristic of brightness at the left end of the right-eye display element 208 is as shown in Fig. 13(a), with the brightest characteristic being obtained in the -27° direction. Similarly, the viewing angle characteristic of chromaticity shift is also highest in the -27° direction.

[0068] The emission angle of the chief ray from the left end of the right-eye display element 208 to the right-eye display optical system is -20° when the observer is looking straight ahead, and -45° when the observer is looking to the left end. When the observer is looking straight ahead, if the color filter is not shifted relative to the pixel at the left end of the display image, the brightness decreases by 12%, and ΔE is 4, as shown at -20° in Figs. 4(a) and (b), respectively. In contrast, when the color filter is shifted relative to the pixel, the brightness is improved to only decrease by 1%, as shown at -20° in Fig. 13(a), and ΔE is also improved to 1 or less, although not shown. Furthermore, when the observer is looking to the left end, if the color filter is not shifted relative to the pixel at the left end of the display image, the brightness is reduced by 50%, and ΔE is 16, as shown at -45° in Figs. 4(a) and (b). In contrast, when the color filter is shifted with respect to the pixel, the brightness is improved to only decrease by 10%, as shown at -45° in FIG. 13(a), and ΔE is also improved to 3, although not shown.

[0069] 13(b), the viewing angle characteristic of brightness at the right end of the right-eye display element 208 as seen by the observer is the brightest at a direction of 55°. Similarly, the viewing angle characteristic of chromaticity shift is also the highest at a direction of 55°.

[0070] The angle of emergence of the chief ray from the right end of the right-eye display element 106 to the right-eye display optical system is 40° when the observer is looking straight ahead, and 60° when looking to the right end.

[0071] At the right end of the displayed image when the observer is looking straight ahead, if the color filter is not shifted relative to the image, the brightness decreases by 41%, as shown at 40° in Figs. 4(a) and (b), and ΔE is 13. In contrast, if the color filter is shifted relative to the image, the brightness decreases by only 7%, as shown at 40° in Fig. 13(b), and ΔE also improves to 2, although not shown. Furthermore, at the right end of the displayed image when the observer is looking at the right end, if the color filter is not shifted relative to the pixel, the brightness decreases by 75%, as shown at 60° in Figs. 4(a) and (b), and ΔE is 25. In contrast, if the color filter is shifted relative to the pixel, the brightness decreases by only 1%, as shown at 60° in Fig. 13(b), and ΔE also improves to 1 or less, although not shown.

[0072] So far, the shift of the color filter at the left and right ends in the horizontal direction of the display element has been described, but the same applies to the top and bottom ends in the vertical direction. In the display optical system of this embodiment, when the observer is looking straight ahead, the exit angle of the chief ray from the display element at the maximum vertical peripheral angle of view of 30° is 20°. Also, when the observer is looking at the end in the vertical direction, the exit angle of the chief ray from the display element at the maximum vertical peripheral angle of view of 30° is 45°.

[0073] At the upper end of the right-eye display element 208 as viewed from the observer, the center of the red color filter is shifted 27° upward from the center of the red sub-pixel. At the lower end of the right-eye display element 208, the center of the red color filter is shifted 27° downward from the center of the red sub-pixel. The same applies to the green and blue color filters.

[0074] By shifting the color filters relative to the pixels as described above, the brightness and chromaticity deviation at the upper and lower ends of the right-eye display element 106 is improved.

[0075] In the display optical system of this embodiment, due to the birefringence of the lenses 204 and 205 and the polarization characteristics of the polarizing plate 250, the phase plates 251 and 253, and the PBS 254, not only the normal light shown in FIG. 9 but also ghost light as unnecessary light that is not reflected by the PBS 254 and is guided to the observer's eye as shown in FIG. 14 may occur. This ghost light occurs when the circularly polarized light that has passed through the first phase plate 251 becomes elliptically polarized due to the birefringence in the lenses 205 and 204, the polarization direction of the linearly polarized light that has passed through the second phase plate 253 is tilted, and the light with the polarized direction that passes through the PBS 254 is guided to the right eye 202. Even if there is no birefringence of the lenses, ghost light also occurs when the polarization characteristics of the polarizing plate 250, the phase plates 251 and 253, and the PBS 254 are not good. The same applies to the display optical system for the left eye.

[0076] As can be seen from Fig. 14, the emission angle of the chief ray of ghost light from the horizontal end of the right-eye display element 208 when the observer is looking straight ahead is 15°, which is inclined on the opposite side to the normal to the right-eye display element 208 compared to the emission angle of the chief ray of normal light in Fig. 9. Therefore, when the viewing angle characteristics of brightness and chromaticity shift are improved by shifting the color filter with respect to the pixel in accordance with the emission angle of the chief ray of normal light as in this embodiment, the brightness of ghost light from the peripheral area of ​​the right-eye display element 208 can be reduced.

[0077] Since the birefringence of a lens generally increases from the center to the peripheral region, the intensity of ghost light due to the birefringence of the lens also increases from the center to the peripheral region. Therefore, in order to reduce the ghost light passing through the peripheral region of the lens, it is effective to reduce the brightness of the light from the peripheral region of the right eye display element 208. Specifically, when the color filter is not shifted, the brightness of the ghost light from the horizontal end of the right eye display element 208 is 93%, whereas when the color filter is shifted, the brightness of the ghost light can be significantly reduced to 12%. The same is true for the vertical direction.

[0078] In this embodiment, the angle φ at which the color filters are shifted outward at the horizontal end portions of the display element at a display angle of 50° is 55°, and the viewing angle characteristics in this direction are better than in the normal direction. At a display angle of 50°, θ1 in Equation 1 and Equation 2 is 60°, and θ2 in Equation 2 is 40°, and the angle φ at which the color filters are shifted outward satisfies the conditions of Equation 1 and Equation 2.

[0079] In addition, the angle φ at which the color filters are shifted outward at the horizontal and vertical ends at a display angle of 30° is 27°, and the viewing angle characteristics in this direction are better than in the normal direction. At a display angle of 30°, θ1 is 45° and θ2 is 20°, and the angle φ at which the color filters are shifted outward satisfies the conditions of formulas 1 and 2.

[0080] When the display angle of view is 50° as in this embodiment, the display angle of view is wide and it is difficult for the viewer to recognize the image of the peripheral area when looking straight ahead. For this reason, it is better to determine the angle at which the color filter is shifted outward by assuming the emission angle of the chief ray from the display element in a certain direction when looking in that direction, rather than when looking straight ahead.

[0081] Furthermore, it is preferable that the angle φmax by which the color filters are shifted outward at the horizontal ends of the display element satisfies the condition of the following formula 3.

[0082] |φmax-θ3|≧15° (Formula 3) Here, θ3 is the emission angle of the chief ray of ghost light (unwanted light) from the horizontal end of the display element when the observer is looking straight ahead, with the direction toward the outside of the display element being positive and the direction toward the center being negative. In this embodiment, φmax is 55° and θ3 is -15°, satisfying the condition of formula 3. If |φmax-θ3| is less than 15°, the emission angle of the ghost light from the display element and the direction with good viewing angle characteristics become close to each other, which is not preferable as it increases the intensity of the ghost light.

[0083] In this embodiment, the color filter has a function of controlling the emission angle of the image light emitted from the display element, and reduces ghost light while improving the viewing angle characteristics of luminance and chromaticity shift in the peripheral area.

[0084] In this embodiment, the angle at which the color filter is shifted outward at the end of the horizontal direction of the display angle of view 50° is set to 55°, with a priority given to the state in which the observer is observing the left and right and to reducing ghost light. However, depending on the use case of the HMD, it may be desired to improve the viewing angle characteristics of the peripheral area when the observer is looking straight ahead even if the display angle of view is large. In this case, the angle at which the color filter is shifted outward at the end of the horizontal direction of the display angle of view 50° may be set to the exit angle of 40° of the chief ray from the display element at the maximum horizontal peripheral angle of view 50° when the observer is looking straight ahead. Furthermore, the shift angle may be set to 50°, which is the average of the exit angle of 40° of the chief ray from the display element at the maximum horizontal peripheral angle of view 50° when the observer is looking straight ahead and the exit angle of 60° of the chief ray from the display element at the maximum horizontal peripheral angle of view 50° when the observer is looking at the end of the horizontal direction.

[0085] As described above, in this embodiment, the color filter has a function of controlling the emission angle, but the emission angle may be controlled by using a microlens as an optical element provided for each pixel. In this case, as in the case of the color filter, the angle (shift amount) by which the center of the microlens is shifted outward from the center of the pixel is made larger in the peripheral region than in the intersection region on the display surface of the display element.

[0086] In this embodiment, the surface on which the half mirror 252 is vapor-deposited is a convex lens surface facing the right-eye display element 208. By vapor-depositing the half mirror 252 on this convex surface, the display optical system can be made thinner and have a wider angle of view. Furthermore, by making the convex surface on which the half mirror 252 is vapor-deposited aspheric, the aberration correction effect can be improved.

[0087] In this embodiment, the observation side surface of the lens 204 on which the second phase plate 253 and the PBS 254 are formed is flat. This is to achieve both a long eye relief and a slim display optical system. For this reason, the lens 204 is a plano-convex lens.

[0088] In this embodiment, the phase difference between the first and second phase plates 251 and 253 is λ / 4, but the phase difference may be shifted from λ / 4 to cancel the birefringence of the lenses 204 and 205. In this case, it is desirable that the sum of the phase differences between the lens 204 and the second phase plate 253 is 3λ / 20 or more and 7λ / 20 or less. It is also desirable that the sum of the phase differences between the lens 205 and the first phase plate 251 is 3λ / 20 or more and 7λ / 20 or less. If it is outside this range, the intensity of ghost light increases, making it impossible to observe a natural image, which is not desirable.

[0089] Furthermore, in the case of resin lenses injection molded using a mold, such as the lenses 204 to 207 in this embodiment, birefringence is large near the molding gate marks. If the birefringence is large, ghost light is generated and the amount of light is reduced. For this reason, as shown in FIG. 15, it is desirable to arrange the molding gate marks 233 of the lenses 205 and 207 on the nose side of the observer. In this embodiment, the display angle of view is wider on the ear side than on the nose side of the observer, and the effective light area of ​​the lens is also wider on the ear side than on the nose side. Therefore, by arranging the molding gate marks on the nose side where the effective light area is narrow, ghost light and light reduction due to large birefringence can be reduced. It is also desirable to arrange the molding gate marks of the lenses 204 and 206 on the nose side of the observer.

[0090] In this embodiment, the display element is an organic EL display that emits unpolarized light, but it may also be a liquid crystal display element that emits linearly polarized light. In this case, the polarizing plate 250 on the display element side is not necessary, and the display optical system can be made thinner.

[0091] The above embodiment includes the following configurations.

[0092] (Configuration 1) a right-eye display element and a left-eye display element each having a plurality of pixels on a display surface; a right-eye display optical system that guides the image light emitted from the right-eye display element to the right eye of an observer, and a left-eye display optical system that guides the image light emitted from the left-eye display element to the left eye of the observer, each of the right-eye and left-eye display elements includes at least one of a color filter and a microlens provided corresponding to each pixel in the plurality of pixels; an intersection point between an optical axis of the right-eye display optical system and a display surface of the right-eye display element and an intersection point between an optical axis of the left-eye display optical system and a display surface of the left-eye display element are shifted with respect to the center of the display surface, An image display device characterized in that, in each of the right eye and left eye display elements, the shift amount of the center of the element corresponding to the pixel toward the periphery is larger within a peripheral region on the peripheral side of the intersection region than within the intersection region including the intersection. (Configuration 2) 2. The image display device according to configuration 1, wherein in each of the right-eye and left-eye display elements, the pitch between adjacent elements in the peripheral region is larger than that in the intersection region. (Configuration 3) 3. The image display device according to configuration 1 or 2, wherein in each of the right-eye and left-eye display elements, the center of the pixel coincides with the center of the element within the intersection region. (Configuration 4) 4. The image display device according to any one of configurations 1 to 3, wherein the shift amount increases from a portion on the intersection side to a portion on the periphery side in the peripheral region. (Configuration 5) 5. The image display device according to configuration 4, wherein the size of the elements increases from the portion on the intersection side to the portion on the periphery side in the peripheral region. (Configuration 6) a display angle of view formed by each of the right-eye and left-eye display optical systems includes a binocular region for displaying an image observed by both eyes of an observer, and a monocular region for displaying an image observed by each of the right eye and the left eye, 6. The image display device according to any one of configurations 1 to 5, wherein the shift amount in the monocular region is larger than the shift amount in the binocular region. (Configuration 7) 7. The image display device according to configuration 6, wherein a display angle of view in the left-right direction of the monocular area is 40° or more. (Configuration 8) When at least one of the luminance and the chromaticity shift according to the emission angle of the image light from the display surface is defined as a viewing angle characteristic, and the viewing angle characteristic is said to be high when the luminance is high and the chromaticity shift is small, 8. The image display device according to any one of configurations 1 to 7, wherein the luminance in the normal direction of the display surface at the center of the display surface is high, and the viewing angle characteristic in the normal direction at the intersection is high. (Configuration 9) When at least one of the luminance and the chromaticity shift according to the emission angle of the image light from the display surface is defined as a viewing angle characteristic, and the viewing angle characteristic is said to be high when the luminance is high and the chromaticity shift is small, At the intersection, the viewing angle characteristic in a normal direction to the display surface is higher than the viewing angle characteristic in a specific direction inclined toward the periphery with respect to the normal direction, 9. The image display device according to any one of configurations 1 to 8, wherein at an end portion of the display surface, the viewing angle characteristic in the normal direction is lower than the viewing angle characteristic in the specific direction. (Configuration 10) Let φ be the inclination angle of the specific direction with respect to the normal direction, and θ1 be the exit angle from the display surface of a chief ray of the image light that travels from the end portion toward the center of an exit pupil where the eyeball of the observer is positioned when the eyeball is facing the end portion. 0<φ≦θ1 10. The image display device according to configuration 9, which satisfies the following conditions: (Configuration 11) When the direction in which the optical axis of each of the right-eye and left-eye display optical systems extends is referred to as the optical axis direction, When the exit angle of the chief ray of the image light from the display surface toward the center of the exit pupil from the end portion when the eyeball is facing the optical axis direction is θ2, θ2≦φ≦θ1 11. The image display device according to claim 10, which satisfies the following conditions: (Configuration 12) the right-eye and left-eye display optical systems each include, in order from a display element side to an observation side, a first phase plate, a semi-transmissive reflective surface, a lens, a second phase plate, and a polarization separation element that reflects first linearly polarized light and transmits second linearly polarized light having a polarization direction perpendicular to the polarization direction of the first linearly polarized light, and guide the image light from the display element side to the observation side via transmission through the semi-transmissive reflective surface, reflection through the polarization separation element, reflection through the semi-transmissive reflective surface, and transmission through the polarization separation element; The inclination angle in the specific direction at the end of the display surface is φmax, and the exit angle from the display surface of a chief ray of unwanted light that passes from the display element side through the semi-transmissive reflective surface and the polarization separation element to the observation side and travels from the end toward the center of the exit pupil when the eyeball is facing the optical axis direction is θ3. |φmax-θ3|≧15° 12. The image display device according to claim 10 or 11, which satisfies the following conditions: (Configuration 13) the lens is manufactured by injection molding using a resin and has a molding gate mark; 13. The image display device according to configuration 12, wherein in each of the right-eye and left-eye display optical systems, the lenses are arranged so that the molding gate trace is located on the nose side of the observer.

[0093] The embodiments described above are merely representative examples, and various modifications and alterations are possible for each embodiment when implementing the present invention. [Explanation of symbols]

[0094] 101,201 HMD 102,202 Observer's right eye 103,203 Observer's left eye 104,204,205 Lens (display optical system for right eye) 105, 206, 207 Lens (left eye display optical system) 106,208 Display element for right eye 107,209 Display element for left eye

Claims

1. A right-eye display element and a left-eye display element, each having multiple pixels on their respective display surfaces, The system includes a right-eye display optical system that guides image light emitted from the right-eye display element to the observer's right eye, and a left-eye display optical system that guides image light emitted from the left-eye display element to the observer's left eye. Each of the right-eye and left-eye display elements has an element which is at least one of a color filter and a microlens, which are provided corresponding to each pixel in the plurality of pixels. The intersection point of the optical axis of the right-eye display optical system and the display surface of the right-eye display element, and the intersection point of the optical axis of the left-eye display optical system and the display surface of the left-eye display element, are each shifted relative to the center of the display surface. An image display device characterized in that, in each of the right-eye and left-eye display elements, the amount of shift of the center of the element corresponding to the pixel toward the periphery is greater in the peripheral region beyond the intersection region than in the intersection region including the intersection.

2. The image display device according to claim 1, characterized in that, in each of the right-eye and left-eye display elements, the pitch between adjacent elements in the peripheral region is larger than that in the intersection region.

3. The image display device according to claim 1, characterized in that in each of the right-eye and left-eye display elements, the center of the pixel and the center of the element coincide within the intersection region.

4. The image display device according to claim 1, characterized in that the shift amount increases from the portion on the intersection side to the peripheral side in the peripheral region.

5. The image display device according to claim 4, characterized in that the size of the element increases from the intersection side portion to the peripheral side portion in the peripheral region.

6. The display field of view formed by each of the right-eye and left-eye display optical systems includes a binocular region that displays the image observed by both of the observer's eyes, and a monocular region that displays the image observed by the right eye and the left eye, respectively. The image display device according to claim 1, characterized in that the amount of shift in the monocular region is greater than the amount of shift in the binocular region.

7. The image display device according to claim 6, characterized in that the display field of view in the left-right direction of the monocular area is 40° or more.

8. When at least one of the brightness and chromaticity shifts corresponding to the emission angle of the image light from the display surface is defined as the viewing angle characteristic, and a high brightness and small chromaticity shift are considered to be the high viewing angle characteristic, The image display device according to claim 1, characterized in that the viewing angle characteristic in the normal direction at the intersection is higher than the viewing angle characteristic in the normal direction at the center of the display surface.

9. When at least one of the brightness and chromaticity shifts corresponding to the emission angle of the image light from the display surface is defined as the viewing angle characteristic, and a high brightness and small chromaticity shift are considered to be the high viewing angle characteristic, At the aforementioned intersection, the viewing angle characteristic in the direction normal to the display surface is higher than the viewing angle characteristic in a specific direction tilted toward the periphery with respect to the normal direction. The image display device according to claim 1, characterized in that at the edge of the display surface, the viewing angle characteristics in the normal direction are lower than the viewing angle characteristics in the specific direction.

10. When the inclination angle of the specific direction with respect to the normal direction is φ, and the emission angle from the display surface of the principal ray of the image light, which is directed from the end of the image light toward the center of the exit pupil where the eyeball is positioned, when the observer's eyeball is facing the end of the image light, 0 < φ ≤ θ1 The image display device according to claim 9, characterized in that it satisfies the following conditions.

11. When the direction in which the optical axes of the respective right-eye and left-eye display optical systems extend is called the optical axis direction, When the exit angle from the display surface of the principal ray of the image light, with the eyeball facing in the direction of the optical axis, is θ2, θ2 ≤ ≤ θ1 The image display device according to claim 10, characterized in that it satisfies the following conditions.

12. The right-eye and left-eye display optical systems each include, arranged in order from the display element side to the observation side, a first phase plate, a semi-transparent reflective surface, a lens, a second phase plate, and a polarization separation element that reflects a first linearly polarized light and transmits a second linearly polarized light in a polarization direction perpendicular to the polarization direction of the first linearly polarized light, and guides the image light from the display element side to the observation side via transmission through the semi-transparent reflective surface, reflection through the polarization separation element, reflection through the semi-transparent reflective surface and transmission through the polarization separation element. When the inclination angle in the specific direction at the end of the display surface is φmax, and the exit angle from the display surface of the principal ray that travels from the end to the center of the exit pupil, when the eyeball is facing in the direction of the optical axis, among the unwanted light that travels from the display element side through the semi-transparent reflective surface and through the polarization separation element to the observation side, is θ3, |φmax−θ3|≧15° The image display device according to claim 10, characterized in that it satisfies the following conditions.

13. The aforementioned lens is manufactured by injection molding of resin and has a molding gate mark. The image display device according to claim 12, characterized in that, in each of the right-eye and left-eye display optical systems, the lens is positioned such that the molding gate mark is located on the nasal side of the observer.

Images