Image display device

Abstract

To provide an image display device that is excellent in visibility.SOLUTION: An image display device has an image display element that creates an image, a light guide optical system that guides the flux of light emitted from the image display element to the pupil of an observer, and a shaping unit that shapes the cross-sectional shape of the flux of light incident on the light guide optical system.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to an image display device having a light guide plate that guides image light to a viewer's pupil. [Background technology]

[0002] Conventionally, an image display device having a light guide plate that guides image light to the observer's pupil is known. FIG. 22 is a conceptual diagram of a light beam propagating in a light guide plate 3. A light beam collimated from an image display element enters a first deflection unit 1, is deflected, and then propagates in a light guide plate 3 to satisfy the total reflection condition. A part of the light beam that enters a second deflection unit 2 is deflected toward the observer's pupil SP, and another part is reflected, is totally reflected in the light guide plate 3, and then enters the second deflection unit 2. By repeating this process, a plurality of light beams are emitted from the second deflection unit 2, and the area where the observer can observe the light beam (hereinafter, the eye box) is expanded. Patent Document 1 discloses a configuration in which a mask that controls the diameter of the emitted light beam is placed between the light guide plate and the second deflection unit to provide a high-quality image to the observer, and a highly uniform light beam distribution is ensured in the eye box. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2022 / 0066216 Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration of Patent Document 1, when the eyebox is enlarged, the diameter of the light beam is varied depending on the emission position and the angle of view, so that each light beam in the eyebox has a discrete distribution. The diameter of the observer's pupil changes depending on the brightness of the outside world and the brightness of the displayed image. When the distribution of each light beam in the eyebox is discrete, some light beams do not reach the retina depending on the pupil diameter, resulting in an area that cannot be visually recognized as an image.

[0005] An object of the present invention is to provide an image display device with excellent visibility. [Means for solving the problem]

[0006] An image display device according to one aspect of the present invention is characterized by having an image display element that generates an image, a light-guiding optical system that guides a light beam emitted from the image display element to an observer's pupil, and a shaping section that shapes the cross-sectional shape of the light beam entering the light-guiding optical system. Effect of the Invention

[0007] According to the present invention, it is possible to provide an image display device with excellent visibility. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of an image display device according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a configuration diagram of an image display device according to a first embodiment. [Diagram 3] FIG. 2 is a configuration diagram of an image generating unit according to the first embodiment. [Figure 4] FIG. 2 is a configuration diagram of an image display element according to the first embodiment. [Diagram 5] FIG. 1 is a diagram showing a light flux distribution in an eye box. [Figure 6] 1 is a diagram showing the relationship between the light flux distribution in the eye box and the observer's pupil. [Figure 7] 4 is a diagram showing the relationship between a light beam from an image generating unit and an incident deflection unit according to the first embodiment. FIG. [Figure 8] 4 is a diagram showing the relationship between the light flux distribution in the eye box and the observer's pupil in the first embodiment. FIG. [Figure 9] 4 is a diagram showing the relationship between a light beam from an image generating unit and an incident deflection unit according to the first embodiment. FIG. [Figure 10] FIG. 11 is a diagram illustrating an example of an image generating unit according to the second embodiment. [Figure 11] FIG. 11 is a diagram illustrating another example of the image generating unit according to the second embodiment. [Figure 12] FIG. 11 is a diagram illustrating another example of the image generating unit according to the second embodiment. [Figure 13] 13 is a diagram showing the relationship between a light beam from an image generating unit and an incident deflection unit according to the second embodiment. FIG. [Figure 14] 13 is a diagram showing the relationship between a light beam from an image generating unit and an incident deflection unit according to the second embodiment. FIG. [Figure 15] FIG. 11 is a configuration diagram of an image generating unit according to a third embodiment. [Figure 16] FIG. 13 is a diagram showing the structure of a MEMS according to a third embodiment. [Figure 17] FIG. 11 is a configuration diagram of a light source according to a third embodiment. [Figure 18] 13 is a diagram showing an image of the distribution of light flux emitted from a light-emitting part of Example 3. FIG. [Figure 19] FIG. 11 is a configuration diagram of a light source according to a third embodiment. [Figure 20] FIG. 11 is a configuration diagram of a light source according to a third embodiment. [Figure 21] FIG. 11 is a configuration diagram of a light source according to a third embodiment. [Figure 22] 1 is a conceptual diagram of a light flux propagating within a light guide plate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to refer to the same components, and duplicated descriptions will be omitted.

[0010] 1 is a diagram showing an example of an image display device according to an embodiment of the present invention. The image display device guides a light beam emitted from an image generating unit (not shown) to an observer (user) 1000 via a light guide plate (light guide optical system) 10, thereby allowing the observer 1000 to view a display image 1100. The image generating units may be disposed for each eye, or may be disposed for one eye. When an image generating unit is disposed for each eye, it is also possible to provide parallax to the display image, allowing the observer 1000 to view the display image 1100 in stereoscopic view.

[0011] The first information acquiring means 910 is, for example, an imaging device such as a camera, and acquires at least one of position information and viewpoint information of the observer 1000. The position information of the observer 1000 is information relating to the position of at least a part of the observer 1000, for example, information relating to the position of the observer's 1000's pupils. The viewpoint information of the observer 1000 is information relating to the viewpoint or line of sight of the observer 1000, for example, information relating to the movement of the observer's pupils. The second information acquiring means 920 is, for example, an imaging device such as a camera, and acquires outside world information (peripheral information).

[0012] The first information acquiring means 910 is capable of acquiring the amount of deviation of the pupil position of the observer 1000 relative to the image generating unit by acquiring position information of the observer 1000. The control means 80 is, for example, a processor such as a CPU (Central Processing Unit), and is capable of correcting the deviation of the relative position based on the information acquired by the first information acquiring means 910.

[0013] The second information acquiring means 920 can acquire the brightness of the outside world by acquiring outside world information. The control means 80 can display the display image 1100 with an appropriate brightness to the observer 1000 based on the information acquired by the second information acquiring means 920. Note that the brightness of the display image 1100 can be arbitrarily determined according to an operation by the observer 1000, regardless of the information acquired by the second information acquiring means 920. EXAMPLES

[0014] FIG. 2 is a configuration diagram of the image display device of this embodiment. The light beam 20 emitted from the image generating unit 100 is deflected by the entrance deflection unit (entrance unit) 10i of the light guide plate 10 and propagates inside the light guide plate 10 by total reflection. The light beam 20a incident on the light beam splitting deflection unit 10e is deflected while being split in the x-axis direction and is guided to the exit deflection unit (exit unit) 10o. The light beam 20b incident on the exit deflection unit 10o is deflected while being split in the y-axis direction and is emitted as the light beam 20c toward the observer's pupil SP (pupil). In this embodiment, the direction deflected by the entrance deflection unit 10i and the direction deflected by the light beam splitting deflection unit 10e are orthogonal to each other, but as long as the light beam incident on the light guide plate 10 is emitted toward the pupil SP, these directions do not need to be orthogonal to each other. In addition, the entrance deflection unit 10i, the light beam splitting deflection unit 10e, and the exit deflection unit 10o are diffraction gratings in this embodiment, but they may be any other units capable of deflecting the light beam 20, such as a hologram or a split mirror.

[0015] FIG. 3 is a configuration diagram of the image generating unit 100 of this embodiment. FIG. 4 is a configuration diagram of the image display element 11 of this embodiment. The image display element 11 is a self-luminous device having pixels 11a in two-dimensional directions, horizontal and vertical (x-axis and y-axis), as shown in FIG. 3. The image display element 11 is, for example, an organic EL (organic electro-luminescence) device or a micro LED (micro light emitting diode) device. The divergent light beam emitted from the image display element 11 is incident on the incident deflection unit 10i as parallel light by an afocal optical system (light-collecting optical system) 12. In this embodiment, the lens optical system shown in FIG. 3(a) is used as the afocal optical system 12, but a prism optical system (including a free curved surface) 13 shown in FIG. 3(b) that deflects the optical path by transmission or reflection may be used. Also, the prism optical system 13 in FIG. 3(b) is composed of two prisms 13a and 13b, but may be composed of one prism or three or more prisms. The control means 80 controls the image display element 11. For example, the control means 80 can display an image to be displayed on the image display element 11, control the lighting of the pixel 11a, and adjust the amount of light. The control means 80 may be provided outside the image generating unit 100. For example, the control means 80 may be disposed outside the frame 900 in FIG. 1, or may be disposed inside the frame 900. When the control means 80 is disposed outside the frame 900, the connection with the frame 900 may be wired or wireless.

[0016] The above-mentioned configuration expands the eyebox 30, which is the area in which the observer can observe the light beam. However, as shown in Fig. 5, each light beam has a finite size (light beam diameter) φ, and the divided and expanded light beams have a discrete distribution. Here, the interval D between each light beam is determined by the propagation distance during total reflection inside the light guide plate 10, and is expressed by the following formula (1) where d is the thickness of the light guide plate 10 and θc is the critical angle of the light guide plate 10.

[0017] D = 2*d*tanθc (1) The critical angle θc is determined by the refractive index nd of the light guide plate 10, and formula (1) is expressed by the following formula (2).

[0018] D = 2*d*tan(asin(1 / nd)) (2) Here, we will explain the influence when the light flux in the eye box 30 has a discrete distribution. As shown in Fig. 6(a), the eye box 30 is enlarged so that the image can be viewed even when the observer's pupil SP moves in two-dimensional directions, horizontally and vertically (x-axis and y-axis). However, when the light flux distribution in the enlarged eye box 30 is discrete as shown in Fig. 6(b), the light flux 20c does not reach the retina Re as shown in Fig. 6(c), and an area that cannot be viewed as an image is generated.

[0019] Therefore, the image display device of this embodiment has a shaping unit disposed between the image display element 11 and the light guide plate 10, which shapes the cross-sectional shape of the light beam incident on the light guide plate 10 so as to fill the spaced light beam distribution. In this embodiment, the entrance deflection unit 10i functions as the shaping unit. By using the shaping unit to shape the cross-sectional shape of the light beam incident on the light guide plate 10 so as to fill the spaced light beam distribution, it is possible to improve visibility.

[0020] Here, shaping means changing the ratio of a specific axis in the cross-sectional shape of a light beam to a diameter in a direction perpendicular to the specific axis, or blocking at least a part of the cross-sectional shape of the light beam.

[0021] In order to fill the eye box 30 with the light beam 20c, it is preferable that the shape of the incident deflection unit 10i is a rectangle, and the incident deflection unit 10i shapes the cross-sectional shape of the light beam incident on the light guide plate 10 into a rectangle. In the description of each embodiment, the rectangle includes not only a strict rectangle but also a substantially rectangular (approximately rectangular) shape. It is more preferable that the shape of the incident deflection unit 10i is a rectangle, and the incident deflection unit 10i shapes the cross-sectional shape of the light beam incident on the light guide plate 10 into a rectangle. In the description of each embodiment, the rectangle includes not only a strict rectangle but also a substantially rectangular (approximately rectangular) shape. It is more preferable that the shape of the incident deflection unit 10i is a square, and the incident deflection unit 10i shapes the cross-sectional shape of the light beam incident on the light guide plate 10 into a square.

[0022] Moreover, it is preferable that the shape of the incident deflection unit 10i is a shape that circumscribes the cross-sectional shape of the light beam emitted from the image display element 11. In this embodiment, the cross-sectional shape of the light beam emitted from the image display element 11 is circular. In the description of each embodiment, the circle shape includes not only a strictly circular shape but also a substantially circular shape (approximately circular shape).

[0023] In this embodiment, the shape of the entrance deflection section 10i is a rectangle circumscribing the cross-sectional shape of the light beam emerging from the image display element 11, and it is preferable that the image display device satisfies the following conditional expression (3).

[0024] L / φ≦1 (3) 7(a), φ is the diameter of the circular light beam 20 that is emitted from the image generating unit 100 and enters the entrance deflection unit 10i, and L is the diagonal length of the entrance deflection unit 10i.

[0025] By satisfying conditional expression (3), the light beam 20 enters the entrance deflection unit 10i so as to encompass it. Only the light beam 20 that enters the entrance deflection unit 10i is deflected, and the rectangular light beam 20, which is substantially the same shape as the entrance deflection unit 10i, propagates through the light guide plate 10 by total reflection. As a result, as shown in Fig. 8, the light beam 20c exiting the exit deflection unit 10o also has a rectangular shape similar to that of the entrance deflection unit 10i, making it possible to fill in the discrete light beam distribution and reduce the light beam that does not pass through the observer's pupil SP.

[0026] The pupil SP of the observer changes depending on the brightness of the outside world, the brightness of the displayed image, the distance of the object being gazed at, etc. In order to avoid the generation of areas that cannot be viewed as an image even in a contracted pupil state, it is preferable to make the intervals between the light beams in the eye box 30 closer together. For this reason, it is desirable to appropriately set the aforementioned interval D. In order to shorten the interval D, it is desirable for the refractive index nd of the light guide plate 10 to be high, and for the thickness d of the light guide plate 10 to be thin.

[0027] 6, a portion of the light beam 21 that is not incident on the entrance deflection portion 10i is not deflected and passes through the light guide plate 10. The light beam 21 becomes unnecessary light because it is not propagated through the light guide plate 10. In order to reduce the unnecessary light and minimize losses, and to more efficiently propagate the light beam to the observer's pupil SP, it is preferable that the image display device of each embodiment satisfies the following conditional expression (4).

[0028] 0.8≦L / φ≦1.0 (4) As shown in FIG. 9, when the shape of the light beam 20 emitted from the image generating unit 100 and incident on the incident deflection unit 10i is not circular but elliptical, the light beam diameter in the short direction of the cross section of the light beam (x-axis direction in the figure) is defined as φ. EXAMPLES

[0029] The image display device of this embodiment has an image generating unit 200 having a different configuration from the image generating unit 100 of embodiment 1. In this embodiment, only the configurations different from embodiment 1 will be described, and the common configurations will be denoted by the same reference numerals as in embodiment 1 and will not be described.

[0030] FIG. 10 is a diagram showing an example of the image generating unit 200 of this embodiment. The image generating unit 200 shapes the light beam having a circular cross section emitted from the image display element 31 before it enters the entrance deflection unit 10i. The light beam emitted from the image display element 31 enters the afocal optical system 32, is shaped inside the afocal optical system 32, and then enters the entrance deflection unit 10i. The afocal optical system 32 is an optical system consisting of at least two lenses. In this embodiment, an aperture arranged inside the afocal optical system 32 functions as a shaping unit that shapes the cross-sectional shape of the light beam entering the light guide plate 10 so as to fill in the spaced light beam distribution. In this embodiment, the shape of the aperture is rectangular. The aperture arranged inside the afocal optical system 32 may be restricted by the outer shape of the lens.

[0031] When the cross-sectional shape of the light beam is shaped by the aperture, the light beam that does not pass through the aperture becomes unnecessary light. Therefore, it is preferable that the afocal optical system 32 shapes the cross-sectional shape of the light beam by combining an anamorphic lens or an aspherical lens. Also, the cross-sectional shape of the light beam may be shaped by using a diffusion plate made of a holographic element or a lens. In that case, as shown in FIG. 11, a shaping element 34 may be disposed outside the afocal optical system 32. Note that, when an element having polarization selectivity such as a holographic element is used as the shaping element 34, it is preferable that a polarizer 35 is disposed between the image display element 31 and the shaping element 34. Furthermore, as shown in FIG. 12, the shaping element 34 may have a light collecting function, and the afocal optical system 32 made of a lens may be eliminated.

[0032] 13, in the image display device of this embodiment, the light beam 33 is incident on the inside of the incident deflection portion 10i, so that it is possible to suppress intrusion of unnecessary light into the light guide plate 10. When the light beam 33 is incident on the inside of the incident deflection portion 10i, the incident deflection portion 10i may be configured in a circular shape as shown in FIG. EXAMPLES

[0033] The image display device of this embodiment has an image generating unit 300 having a different configuration from the image generating unit 100 of embodiment 1. In this embodiment, only the configurations different from embodiment 1 will be described, and the same reference numerals as in embodiment 1 will be used for the common configurations, and the description thereof will be omitted.

[0034] FIG. 15 is a configuration diagram of the image generating unit 300 of this embodiment. The image generating unit 300 has an image display element that is a non-self-luminous element. In this embodiment, a MEMS 41 is used as the image display element. A light beam emitted from the light source 40 is incident on the MEMS 41. As shown in FIG. 16, the MEMS 41 is assumed to be a two-dimensional type of raster scan in which the circular reflecting surface 42 is deflected around the x-axis and y-axis with the center of the reflecting surface 42 as the axis. When the light beam emitted from the light source 40 is incident on the reflecting surface 42, the reflecting surface 42 is tilted by an angle ω, and the emitted light beam is tilted by an angle θ (=2ω) to be emitted as a light beam 43 (43+, 43-) and enters the entrance deflection unit 10i.

[0035] FIG. 17 is a configuration diagram of the light source 40. FIG. 18 is a diagram showing an image of the distribution of the light beam emitted from the light-emitting unit 44. The light emitted from the light-emitting unit 44 is linearly polarized light, and has different divergence angles in the x-axis direction and the y-axis direction. Therefore, the light beam cross section (FFP) in the xy cross section perpendicular to the z-axis is elliptical. When the elliptical light beam cross section is collimated by a collimator lens 45 having the same focal length, a collimated light beam 46 having an elliptical distribution with the x-axis direction as the minor axis is emitted from the light source 40, as shown in FIG. 18(c).

[0036] In this embodiment, a shaping section that shapes the cross-sectional shape of the light beam incident on the MEMS 41 so as to fill in the spaced light beam distribution is disposed inside the light source 40. Specifically, as shown in Fig. 19, an aperture 47 having a rectangular opening is disposed on the light exit side of the collimator lens 45. This allows the shape of the light beam 48 emitted from the light source 40 to be rectangular.

[0037] Incidentally, even when the cross-sectional shape of the light beam is shaped within the light source 40, in order to fill the eye box 30 with the light beam, the shaped shape of the light beam is preferably a quadrangle, more preferably a rectangle, and even more preferably a square.

[0038] However, if the cross-sectional shape of the light beam is changed from an elliptical light beam distribution to a square shape by an aperture, the amount of unnecessary light that cannot be used increases. Therefore, as shown in FIG. 20, it is preferable to shape the cross-sectional shape of the light beam by a collimator lens system 50 including a plurality of collimator lenses. In FIG. 20, the collimator lens system 50 includes a cylindrical lens 53 having a positive power only in the x-axis direction and a cylindrical lens 52 having a positive power only in the y-axis direction. The cross-sectional shape of the light beam 55 can be shaped into a circle by collimating the light beam having different divergence angles in the x-axis direction and the y-axis direction from the light emitting unit 44 by the cylindrical lenses 52 and 53 having different focal lengths. In this way, by shaping the cross-sectional shape of the light beam before it enters the aperture 54, the loss at the aperture 54 can be reduced.

[0039] When the diameter of the emitted light beam is increased, a collimator optical system 60 including a negative cylindrical lens 62 that expands the direction of a small divergence angle may be disposed as shown in Fig. 21. It is also preferable to shape the emitted light beam into a rectangle by using an aspheric lens, a free-form lens, a CGH device, or the like in the collimator optical system 60. Note that if a desired light beam shape is obtained when the light beam is emitted from the collimator optical system 60, the aperture 47 does not need to be disposed.

[0040] The cross-sectional shape of the light beam emitted from the light source 40 is preferably a shape that circumscribes the reflecting surface 42 of the MEMS 41. Note that the shape of the reflecting surface 42 of the MEMS 41 is circular, as described above.

[0041] In this embodiment, the cross-sectional shape of the light beam emitted from the light source 40 is a rectangle inscribed in the reflecting surface 42, and it is preferable that the image display device satisfies the following conditional expression (5).

[0042] Ld / φm≦1.0 (5) Here, φm is the diameter of the reflecting surface 42 of the MEMS 41. Ld is the diagonal length of the light beam emitted from the light source 40 and incident on the reflecting surface 42.

[0043] If the upper limit is exceeded, reflection and deflection will not occur at the reflecting surface 42, and the light utilization efficiency will decrease.

[0044] It is more preferable that the image display device satisfy the following conditional formula (6), which defines the lower limit of conditional formula (5).

[0045] 0.8≦φm / Ld≦1.0 (6) If the value falls below the lower limit, the light incident on the input deflection unit 10i is totally reflected by the opposing surface, enters the input deflection unit 10i again, and is emitted from the input deflection unit 10i as unwanted light. As a result, the intervals between the light beams in the eye box 30 increase, and the light beam weighting rate in the eye box 30 decreases.

[0046] The disclosure of this embodiment includes the following configurations and methods. (Configuration 1) an image display element for generating an image; a light guiding optical system that guides a light beam emitted from the image display element to a pupil of an observer; and a shaping section for shaping a cross-sectional shape of a light beam incident on the light-guiding optical system. (Configuration 2) 2. The image display device according to configuration 1, wherein the shaping section shapes a cross-sectional shape of a light beam incident on the light-guiding optical system into a quadrangle. (Configuration 3) 2. The image display device according to configuration 1, wherein the shaping section shapes a cross-sectional shape of a light beam incident on the light-guiding optical system into a rectangular shape. (Configuration 4) 4. The image display device according to any one of configurations 1 to 3, wherein a cross-sectional shape of a light beam emitted from the image display element is circular. (Configuration 5) The image display device according to any one of configurations 1 to 4, characterized in that the light guiding optical system includes an entrance section into which the light beam emitted from the image display element is incident, and an exit section that emits the light beam emitted from the image display element to the pupil of the observer. (Configuration 6) 6. The image display device according to configuration 5, wherein the shaping section is the incident section. (Configuration 7) 7. The image display device according to configuration 6, wherein the shape of the entrance portion is a shape that circumscribes a cross-sectional shape of a light beam emitted from the image display element. (Configuration 8) The shape of the incident portion is rectangular, When the diameter of the light beam incident on the incident portion is φ and the diagonal length of the incident portion is L, L / φ≦1 8. The image display device according to configuration 7, wherein the following condition is satisfied: (Configuration 9) 6. The image display device according to any one of configurations 1 to 5, further comprising a light-collecting optical system for collimating a light beam emitted from the image display element. (Configuration 10) 10. The image display device according to configuration 9, wherein the shaping unit is disposed inside the light collecting optical system. (Configuration 11) 11. The image display device according to configuration 10, wherein the shaping unit is a diaphragm. (Configuration 12) A light source; an image display element that deflects a light beam emitted from the light source; a light guiding optical system that guides a light beam emitted from the image display element to a pupil of an observer; and a shaping section for shaping a cross-sectional shape of a light beam incident on the image display element. (Configuration 13) 13. The image display device according to configuration 12, wherein the shaping section shapes the cross-sectional shape of the light beam incident on the image display element into a quadrangle. (Configuration 14) 13. The image display device according to configuration 12, wherein the shaping section shapes the cross-sectional shape of the light beam incident on the light-guiding optical system into a rectangle. (Configuration 15) 15. The image display device according to any one of configurations 12 to 14, wherein a cross-sectional shape of the light beam emitted from the light source is circular. (Configuration 16) 16. The image display device according to any one of configurations 12 to 15, wherein a cross-sectional shape of a light beam emitted from the light source is an ellipse. (Configuration 17) 17. The image display device according to any one of configurations 12 to 16, wherein the shaping unit is disposed inside the light source. (Configuration 18) The light source includes a light emitting unit and an optical system. 18. The image display device according to configuration 17, wherein the shaping unit is a diaphragm included in the optical system. (Configuration 19) 19. The image display device according to any one of configurations 12 to 18, wherein a cross-sectional shape of a light beam incident on the image display element is a shape inscribed in the image display element. (Configuration 20) The cross-sectional shape of the light beam emitted from the light source is rectangular, When the diameter of the image display element is φm and the diagonal of the light beam incident on the image display element is Ld, Ld / φm≦1 20. The image display device according to configuration 19, wherein the following condition is satisfied:

[0047] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0048] 10 Light guide plate (light guide optical system) 10i Deflection incidence section (shaping section) 11 Image display element 1000 Observers

Claims

1. an image display element for generating an image; a light guiding optical system that guides a light beam emitted from the image display element to a pupil of an observer; and a shaping section for shaping a cross-sectional shape of a light beam incident on the light-guiding optical system.

2. 2 . The image display device according to claim 1 , wherein the shaping section shapes the cross-sectional shape of the light beam incident on the light guide optical system into a quadrangle.

3. 2. The image display device according to claim 1, wherein the shaping section shapes the cross section of the light beam incident on the light guide optical system into a rectangular shape.

4. 4. The image display device according to claim 1, wherein a cross-sectional shape of the light beam emitted from the image display element is circular.

5. 4. The image display device according to claim 1, wherein the light-guiding optical system comprises an entrance section into which the light beam emitted from the image display element is incident, and an exit section that emits the light beam emitted from the image display element to the pupil of the observer.

6. The image display device according to claim 5 , wherein the shaping section is the incident section.

7. 7. The image display device according to claim 6, wherein the shape of the entrance portion is a shape that circumscribes a cross-sectional shape of a light beam emitted from the image display element.

8. The shape of the incident portion is rectangular, When the diameter of the light beam incident on the incident portion is φ and the length of the diagonal of the incident portion is L, L / φ≦1 8. The image display device according to claim 7, wherein the following condition is satisfied:

9. 4. The image display device according to claim 1, further comprising a light-collecting optical system for collimating a light beam emitted from the image display element.

10. The image display device according to claim 9 , wherein the shaping unit is disposed inside the light collecting optical system.

11. 11. The image display device according to claim 10, wherein the shaping unit is a diaphragm.

12. A light source; an image display element that deflects a light beam emitted from the light source; a light guiding optical system that guides a light beam emitted from the image display element to a pupil of an observer; and a shaping section for shaping a cross-sectional shape of a light beam incident on the image display element.

13. 13. The image display device according to claim 12, wherein the shaping section shapes the cross section of the light beam incident on the image display element into a quadrangle.

14. 13. The image display device according to claim 12, wherein the shaping section shapes the cross section of the light beam incident on the light guide optical system into a rectangular shape.

15. 15. The image display device according to claim 12, wherein a cross-sectional shape of the light beam emitted from the light source is circular.

16. 15. The image display device according to claim 12, wherein a cross-sectional shape of the light beam emitted from the light source is elliptical.

17. 15. The image display device according to claim 12, wherein the shaping section is disposed inside the light source.

18. The light source includes a light emitting unit and an optical system.

18. The image display device according to claim 17, wherein the shaping unit is a diaphragm included in the optical system.

19. 15. The image display device according to claim 12, wherein a cross-sectional shape of a light beam incident on said image display element is a shape circumscribing said image display element.

20. The cross-sectional shape of the light beam emitted from the light source is rectangular, When the diameter of the image display element is φm and the diagonal of the light beam incident on the image display element is Ld, Ld / φm≦1 20. The image display device according to claim 19, wherein the following condition is satisfied:

Images