Image display device

Abstract

An image display device is provided with which a high-resolution image of a wide field of view can be generated while achieving a reduction in the size of the device. The invention provides an image display device comprising: a display panel that generates image light; an optical system that transmits the image light having a predetermined polarization direction and directs the image light to a pupil of an observer; a reflection plate that reflects, toward the optical system, image light from the display panel that corresponds to a first region in a field of view of the observer; and a polarization control unit that switches the polarization direction of the image light, the polarization control unit switching alternately between the image light polarization direction corresponding to the first region and an image light polarization direction corresponding to a second region that is different from the first region in the field of view of the observer.

Description

Technical Field

[0001] The technology disclosed herein (also referred to below as "the technology") relates to an image display device. Background Technology

[0002] Traditionally, in the technology fields related to extended reality (XR) such as virtual reality (VR) and augmented reality (AR), techniques have been used to generate images by projecting light onto the pupil.

[0003] For example, Patent Document 1 discloses a technology related to an "optical unit of a head-mounted display device," which is characterized by comprising: a light-emitting part that converges light emitted from a light source; a display part that uses the light converged by the light-emitting part as illumination light to generate video light; a projection lens that projects video light from the display part; an optical axis conversion element that shifts the optical axis of the video light projected from the projection lens; and a light guide plate that receives video light having an optical axis shifted by the optical axis conversion element as input and guides the video light to the wearer's pupil.

[0004] In Patent Document 1, MEMS mirrors and liquid crystal panels with refractive indices varying for each unit were used as optical axis conversion elements.

[0005] Reference List

[0006] Patent documents

[0007] Patent Document 1: JP-2022-160182-A Summary of the Invention

[0008] Technical issues

[0009] However, when the optical axis is shifted using the technology disclosed in Patent Document 1, the image becomes unviewable in some cases due to the shift of the optical axis, rotation of the eyeball, etc.

[0010] Furthermore, using MEMS mirrors as optical axis conversion elements may increase the device size. When using liquid crystal panels with varying refractive indices for each cell as optical axis conversion elements, the limited number of pixels makes it difficult to generate high-resolution images in some cases.

[0011] For example, in virtual reality (VR) and similar applications where the size of the display panel decreases, the optical power increases because the light rays used to visualize the image need to be bent. Therefore, pancake optical systems with reflective surfaces are used, but limitations exist.

[0012] To improve the pixel density (PPD) near the center, an optical system is suitable for converging image light from many pixels on the display panel onto the observer's central vision. However, if image light from many pixels is converged onto the central vision, it becomes less likely that the image light will enter the observer's peripheral vision. In cases where image light enters the observer's peripheral vision, there is a possibility of reduced resolution.

[0013] Therefore, the main objective of this technology is to provide an image display device that can generate high-resolution images with a wide field of view while aiming to reduce device size.

[0014] Solution to the problem

[0015] This technology provides an image display device, including:

[0016] Display panel, the display panel generates image light;

[0017] An optical system that transmits image light having a predetermined polarization direction and guides the image light having a predetermined polarization direction to the observer's pupil;

[0018] A reflector that reflects image light from the display panel that corresponds to a first region in the observer's field of view toward the optical system; and

[0019] A polarization control unit switches the polarization direction of the image light, wherein...

[0020] The polarization control unit alternately switches between the polarization direction of the image light corresponding to the first region and the polarization direction of the image light corresponding to the second region, which is different from the first region in the observer's field of vision.

[0021] The image display device may further include a polarization conversion unit that converts the polarization direction of image light from the display panel.

[0022] The polarization conversion unit can be arranged outside the display panel and in the vertical direction of the display panel, and

[0023] The polarization conversion unit and the reflector can be stacked sequentially from the side where the image light is incident.

[0024] When the width of the display panel is s, the width of the reflector is l, the length of the gap between the reflector and the display panel is q, and the angle formed between the reflector and the line segment connecting the center of the display panel and the end of the reflector on one side of the optical system is α, the mathematical expression (1) can be satisfied.

[0025] s / 2=(l+q)·tan(α)……(1)

[0026] The optical system may include: a polarized light transmission section that selectively transmits linearly polarized light; and a lens. The display panel, the polarization control section, and the polarization conversion section may be stacked in the order in which image light passes.

[0027] The optical system may have a diffractive lens based on geometric phase.

[0028] The reflector can be arranged between the pupil and the optical system, and between the optical system and the polarization control unit.

[0029] The optical system may include: a polarized light transmission section that selectively transmits linearly polarized light; and a lens; and

[0030] The polarization conversion unit, which converts the polarization direction of image light from the display panel, can be arranged between the optical system and the polarization control unit.

[0031] The optical system may have a diffractive lens based on geometric phase.

[0032] The reflector can be arranged at an angle relative to the vertical direction of the display panel.

[0033] When the width of the display panel is s, the width of the reflector is l, the length of the gap between the reflector and the display panel is q, and the tilt angle of the reflector is β, the mathematical expression (2) can be satisfied.

[0034] l·sinβ+s / 2=(l·cosβ+q)·tan(2β)……(2)

[0035] The optical system can transmit a portion of the image light and reflect a portion of the image light toward the reflector.

[0036] The optical system can be integrally formed as including: a polarization conversion unit that converts the polarization direction of image light from the display panel; and a polarized light transmission unit that selectively transmits linearly polarized light.

[0037] The optical system can transmit a portion of the image light and reflect a portion of the image light toward the reflector, and

[0038] The reflector can reflect a portion of the image light toward the optical system and a portion of the image light toward the pupil.

[0039] Optical elements that change the direction of image light can be arranged between the display panel and the reflector.

[0040] The image display device may further include an image control unit, which synchronizes the timing of the display panel switching image light with the timing of the polarization control unit switching polarization direction.

[0041] The image control unit can invert the image corresponding to the first region.

[0042] The image control unit can turn off the display panel at a timed interval when the image corresponding to the first region and the image corresponding to the second region are switched.

[0043] The first area can be the surrounding view, and

[0044] The second area can be the central field of vision.

[0045] This technology can provide an image display device capable of generating high-resolution images with a wide field of view while aiming to reduce device size. Note that the advantageous effects described herein are not necessarily a single advantageous effect, but can be any advantageous effect described in this disclosure. Attached Figure Description

[0046] Figure 1 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0047] Figure 2 This is an explanatory diagram illustrating an operational example of an image display device 100 according to an embodiment of the present technology.

[0048] Figure 3 This is a schematic diagram illustrating an example of an image displayed by an image display device 100 according to an embodiment of the present technology.

[0049] Figure 4 This is a schematic diagram illustrating an example configuration of the polarization control unit 5 according to an embodiment of the present technology.

[0050] Figure 5 This is a flowchart illustrating an operational example of an image display device 100 according to an embodiment of the present technology.

[0051] Figure 6 This is a diagram illustrating an operational example of an image display device 100 according to an embodiment of the present technology.

[0052] Figure 7 This is a schematic diagram illustrating an operational example of an image display device 100 according to an embodiment of the present technology.

[0053] Figure 8 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0054] Figure 9 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0055] Figure 10 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0056] Figure 11 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0057] Figure 12 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0058] Figure 13 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0059] Figure 14 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0060] Figure 15 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0061] Figure 16 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0062] Figure 17 This is a schematic diagram illustrating an example configuration of an optical element 8 according to an embodiment of the present technology. Detailed Implementation

[0063] In the following description, suitable embodiments for implementing the present technology are illustrated with reference to the accompanying drawings. Note that the embodiments described below are shown as examples of representative embodiments of the present technology and do not limit the scope of the present technology. Furthermore, the present technology allows any combination of the implementation examples and their modifications described below.

[0064] In the following description of embodiments, in some cases, terms such as "generally parallel" or "generally orthogonal" accompanied by "generally" are used to describe the configuration. For example, the term "generally parallel" means not only perfectly parallel, but also substantially parallel, that is, it means a deviation from a perfectly parallel state, for example, by about a few percent. This also applies to other terms accompanied by "generally". Additionally, each figure is schematic and not necessarily shown with strict accuracy. To make the technical features easier to understand, the scale of the figures has been exaggerated. Therefore, it should be noted that the scale of the figures is not necessarily the same as the scale of the actual device.

[0065] Unless otherwise specified, in the accompanying drawings, "upper" refers to the upward direction or upper side, "lower" refers to the downward direction or lower side, "left" refers to the left direction or left side, and "right" refers to the right direction or right side. Furthermore, in the accompanying drawings, identical or equivalent elements or parts are given the same reference numerals, and redundant descriptions are omitted.

[0066] The instructions are provided in the following order.

[0067] 1. First embodiment of this technology (Example 1 of an image display device)

[0068] (1) Overall configuration

[0069] (2) Operation example

[0070] (3) Polarization control unit

[0071] 2. A second embodiment of this technology (Example 2 of an image display device)

[0072] 3. A third embodiment of this technology (Example 3 of an image display device)

[0073] 4. Fourth embodiment of the present technology (Example 4 of an image display device)

[0074] 5. Fifth embodiment of the present technology (Example 5 of an image display device)

[0075] 6. The sixth embodiment of this technology (Example 6 of an image display device)

[0076] 7. The seventh embodiment of this technology (Example 7 of an image display device)

[0077] 8. The eighth embodiment of this technology (Example 8 of an image display device)

[0078] 9. The ninth embodiment of this technology (Example 9 of an image display device)

[0079] 10. The tenth embodiment of this technology (Example 10 of an image display device)

[0080] [1. First embodiment of the present technology (Example 1 of an image display device)]

[0081] [(1) Overall Configuration]

[0082] This technology provides an image display device, comprising: a display panel that generates image light; an optical system that transmits image light having a predetermined polarization direction and guides the image light having the predetermined polarization direction to the pupil of an observer; a reflector that reflects image light from the image light from the display panel corresponding to a first region in the observer's field of vision toward the optical system; and a polarization control unit that switches the polarization direction transmitted by the optical system, wherein the polarization control unit alternately switches between the polarization direction of the image light corresponding to the first region and the polarization direction of the image light corresponding to a second region, the second region being different from the first region in the observer's field of vision.

[0083] refer to Figure 1 To illustrate a configuration example of an image display device according to an embodiment of the present technology. Figure 1 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0084] like Figure 1 As shown, the image display device 100 includes a display panel 1, an optical system 2, a polarization conversion unit 3, a reflector 4, and a polarization control unit 5.

[0085] Display panel 1 generates image light. Specifically, the display panel alternately generates image light corresponding to a first region in the observer's field of vision and image light corresponding to a second region in the observer's field of vision that is different from the first region. For example, the first region may be peripheral vision. For example, the second region may be central vision.

[0086] An observer's field of vision consists of a central field of vision and a peripheral field of vision. The central field of vision is the area located at the center of the field of vision. This area is particularly suitable for acquiring detailed visual information, focusing on target objects, and assisting in high-precision visual recognition. On the other hand, the peripheral field of vision refers to the area of ​​vision that deviates from the central field of vision and is usually located on the outer part of the field of vision. Compared with the central field of vision, this area has a lower capacity to provide detailed visual information and is mainly used for perceiving motion and wide scenes.

[0087] The polarization control unit 5 switches the polarization direction of the image light synchronously with the display panel 1. Specifically, the polarization control unit 5 alternately switches the polarization direction of the image light corresponding to a first region in the observer's field of view and the polarization direction of the image light corresponding to a second region in the observer's field of view that is different from the first region.

[0088] In this configuration example, the polarization conversion unit 3 is arranged outside the display panel 1 and in the vertical direction of the display panel 1. Thus, the polarization conversion unit 3 and the reflector 4 are stacked sequentially from the side where the image light is incident. This schematic diagram is a view from the observer's upward direction. Therefore, the polarization conversion unit 3 and the reflector 4 are arranged in the left-right direction as seen from the observer.

[0089] The polarization conversion unit 3 converts the polarization direction of the image light from the display panel 1. For example, the polarization conversion unit 3 can be a wave plate or the like. The wave plate includes multiple refractive materials and is capable of rotating the polarization direction of linearly polarized light and converting linearly polarized light into circularly polarized light. A wave plate whose rotational transmittance is unlikely to fluctuate with the incident angle is suitable.

[0090] As wave plates, for example, half-wave plates (HWPs) and quarter-wave plates (QWPs) can be used. An HWP is a wave plate that rotates the polarization direction of linearly polarized light by 180 degrees. Linearly polarized light that has passed through an HWP is polarized in a direction perpendicular to the incident polarization direction. A QWP is a wave plate that converts linearly polarized light into circularly polarized light.

[0091] Note that there are no particular restrictions on the shape of the waveplate, and it can be, for example, plate-shaped or film-shaped.

[0092] Image light from the polarization control unit 5 passes through the polarization conversion unit 3, is then reflected by the reflector 4, and passes through the polarization conversion unit 3 again. For example, when the image light from the polarization control unit 5 is S-polarized light, which is linearly polarized, it is converted into right-hand circularly polarized light by passing through the polarization conversion unit 3. Then, the image light converted into right-hand circularly polarized light is converted into left-hand circularly polarized light by being reflected by the reflector 4. Then, the image light converted into left-hand circularly polarized light is converted into P-polarized light, which is linearly polarized, by passing through the polarization conversion unit 3 again. In this way, S-polarized light emitted from the polarization control unit 5 is converted into P-polarized light. That is, when the image light emitted directly from the polarization control unit 5 to the pupil (especially the central field of vision) is S-polarized light, the image light guided to the pupil (especially the peripheral field of vision) via the polarization conversion unit 3 and the reflector 4 is P-polarized light.

[0093] Reflector 4 reflects the image light from the display panel 1 that corresponds to a first region (e.g., peripheral field of vision) in the observer's field of vision toward the optical system 2. This image light is displayed as an image (virtual image) in the first region (e.g., peripheral field of vision) in the observer's field of vision. On the other hand, the image light from the display panel 1 that is not reflected by reflector 4 is displayed as an image (virtual image) in a second region (e.g., central field of vision) in the observer's field of vision. Note that reflector 4 can also reflect the image light corresponding to the second region toward the optical system 2.

[0094] Optical system 2 transmits image light with a predetermined polarization direction and guides the image light to the observer's pupil. In this configuration example, optical system 2 includes: a polarized light transmission section 21 that selectively transmits linearly polarized light; and a lens 22. For example, polarization conversion section 3 is a polarizer and selectively transmits either S-polarized light or P-polarized light, which is linearly polarized light. Lens 22 guides the image light to the observer's pupil.

[0095] When the width of the display panel 1 is s, the width of the reflector 4 is l, the length of the gap between the reflector 4 and the display panel 1 is q, and the angle formed between the reflector 4 and the line segment connecting the center of the display panel 1 and the end of the reflector 4 on one side of the optical system 2 is α, the following mathematical expression (1) is appropriately satisfied.

[0096] s / 2=(l+q)·tan(α)……(1)

[0097] By satisfying this mathematical expression, the peak brightness distribution near the center of display panel 1 is improved. As a result, image light from near the center of display panel 1 is more likely to reach the pupil.

[0098] [(2) Operation Example]

[0099] refer to Figure 2 To illustrate an operational example of the image display device 100. Figure 2 This is an explanatory diagram illustrating an operational example of an image display device 100 according to an embodiment of the present technology.

[0100] Figure 2 Figure A illustrates how to polarize the image light corresponding to a second region (e.g., the central field of view). For example... Figure 2 As shown in Figure A, for example, display panel 1 generates image light corresponding to a second region (e.g., the central field of view). Polarization control unit 5 converts the image light with a polarization direction into P-polarized light. The image light obtained by the conversion by polarization control unit 5 is guided to the second region in the observer's field of view via optical system 2 without passing through polarization conversion unit 3. Optical system 2 transmits P-polarized light. Since the image light is thus guided to the second region, the observer can observe the image corresponding to the second region. That is, the image corresponding to the second region is displayed in the second region in the observer's field of view.

[0101] At this time, when the image light is reflected by reflector 4 and passes through polarization conversion unit 3, it is converted from P-polarized light to S-polarized light. Since optical system 2 does not transmit S-polarized light, the image light is not guided to the first region. Therefore, the image corresponding to the second region is not displayed in the observer's first region.

[0102] Figure 2 B illustrates how to polarize the image light corresponding to a first region (e.g., peripheral view). For example... Figure 2 As shown in Figure B, the display panel 1 generates image light corresponding to a first region (e.g., peripheral field of view). The polarization control unit 5 converts the image light with a polarization direction into S-polarized light. When the image light is reflected by the reflector 4 and passes through the polarization conversion unit 3, the image light is converted from S-polarized light to P-polarized light. Since the optical system 2 transmits P-polarized light, the image light is guided to the first region. The observer can observe the image corresponding to the first region. That is, the image corresponding to the first region is displayed in the first region of the observer's field of view.

[0103] On the other hand, since optical system 2 does not transmit S-polarized light, image light reaching optical system 2 without being reflected by reflector 4, etc., is not transmitted through optical system 2. That is, the image light is not guided to the second region. As a result, the image corresponding to the first region is not displayed in the second region of the observer's field of view.

[0104] Alternate switching Figure 2 The state shown in A and Figure 2 The state shown in B.

[0105] refer to Figure 3 Further explanation of the operation example of the image display device 100. Figure 3 This is a schematic diagram illustrating an example of an image displayed by an image display device 100 according to an embodiment of the present technology. In the following description, for simplicity, an example is described where the first region is the peripheral field of view and the second region is the central field of view.

[0106] Figure 3 A shows the image to be displayed in the observer's central field of vision. Figure 3 Figure B shows the image to be displayed in the observer's peripheral field of vision. Display panel 1 (see...) Figure 1 Alternate generation Figure 3 The image light and image shown in A Figure 3 The image light shown in B.

[0107] Figure 3 C and Figure 3 The diagram illustrates how an observer uses the image display device 100 to view an image. Figure 3 In C, the image corresponding to the central field of view is displayed, but the image corresponding to the peripheral field of view is not displayed.

[0108] On the other hand, Figure 3 In D, via reflector 4 (see Figure 1 The image corresponding to the peripheral field of view is displayed, but the image corresponding to the central field of view is not displayed. Since the image corresponding to the peripheral field of view is reflected by reflector 4, it is... Figure 3 The image shown in B is a left-right inverted image. The image control unit, mentioned later, inverts the image corresponding to the peripheral field of view.

[0109] By alternating displays Figure 3 The image shown in C and Figure 3 The image shown in D allows the observer to observe... Figure 3 The image shown in E. In this way, the image display device 100 can generate high-resolution images with a wide field of view while reducing the size. This beneficial effect is similarly achieved in other embodiments mentioned later. Therefore, in the description of other embodiments, repeated descriptions are omitted in some cases.

[0110] Furthermore, according to this embodiment, since the main rays of image light from the display panel are converged to the observer's central field of view, the PPD (pixels per degree) near the center can be increased.

[0111] Note that although reflector 4 is arranged in the left-right direction of the observer in this configuration example, reflector 4 could, for example, be arranged in the up-down direction of the observer. In this case, display panel 1 appropriately generates image light that is inverted in the up-down direction.

[0112] Additionally, the second region can be the peripheral field of vision, and the first region can be the central field of vision. Furthermore, each of the second and first regions can be a field of vision other than the central and peripheral fields of vision. Examples of fields of vision include dark field, blind spot, afterimage field, etc.

[0113] Additionally, an image corresponding to the first region can be displayed in the observer's second region. Conversely, an image corresponding to the second region can be displayed in the observer's first region. A portion of each of the second and first regions can overlap. For example, a portion of the second region can be included in the first region, and vice versa.

[0114] [(3) Polarization control unit]

[0115] refer to Figure 4 Here is an example of the configuration of the polarization control unit 5. Figure 4 This is a schematic diagram illustrating an example configuration of the polarization control unit 5 according to an embodiment of the present technology.

[0116] like Figure 4 As shown, the polarization control unit 5 has a transparent electrode 52 disposed on both surfaces of the liquid crystal 51. For example, the transparent electrode 52 comprises a conductive material such as ITO, ZnO, or PEDOT. A polarizer 53 is disposed on the surface of the transparent electrode 52 facing the display panel (not shown).

[0117] An image control unit 6 is connected to each transparent electrode 52. A power supply 7 is connected to the image control unit 6. By applying a voltage to the liquid crystal 51 via each transparent electrode 52 through the image control unit 6, the polarization direction of the liquid crystal 51 can be changed.

[0118] Note that, although not shown in the accompanying figures, spatial light modulators (SLMs) can be further used to control the polarization direction of the image light.

[0119] Furthermore, although the polarization control unit 5 is configured to use a liquid crystal as an example, this configuration is not the only example. For example, an electrical engineering crystal can be used as the polarization control unit 5. An electrical engineering crystal is a polarization element that utilizes the property that its resistance changes depending on the polarization state of light. An electrical engineering crystal can cause current to flow or generate voltage according to the polarization state of the incident light. Electrical engineering crystals have advantages such as high polarization transmittance and availability over a wide wavelength range.

[0120] The image control unit 6 synchronizes the timing of the image switching light on the display panel with the timing of the polarization direction switching by the polarization control unit. (Reference) Figure 5 To illustrate this point. Figure 5 This is a flowchart illustrating an operational example of an image display device 100 according to an embodiment of the present technology.

[0121] like Figure 5 As shown, firstly, at step S1, a control signal is input to each of the polarization control unit 5 and the image control unit 6.

[0122] Next, in step S2, a video signal is input to the image control unit 6. This video signal alternately includes image frames corresponding to the first region and image frames corresponding to the second region. The frame rate is not particularly limited at this time, but is appropriately higher. For example, the frame rate is appropriately equal to or higher than 120 fps, more appropriately equal to or higher than 240 fps, and even more appropriately equal to or higher than 480 fps.

[0123] Next, in step S3, the image control unit 6 reverses the image frame corresponding to the first region.

[0124] Next, in step S4, the display panel 1 generates image light based on the video signal. At this time, the image control unit 6 synchronizes the timing of the display panel switching the image light with the timing of the polarization control unit switching the polarization direction.

[0125] Further reference Figure 6 To illustrate this point. Figure 6 This is a diagram illustrating an operational example of an image display device 100 according to an embodiment of the present technology.

[0126] Figure 6 Figure A is a diagram illustrating an operational example of the polarization control unit 5. The horizontal axis represents time, and the vertical axis represents the voltage applied to the polarization control unit 5. Figure 6 As shown in A, the time period during which voltage is applied to the polarization control unit 5 and the time period during which voltage is not applied to the polarization control unit 5 are repeated alternately.

[0127] Figure 6B is a diagram representing the polarization direction of the image light emitted by the polarization control unit 5. When a voltage is applied, for example, the polarization control unit 5 emits P-polarized light. When no voltage is applied, for example, the polarization control unit 5 emits S-polarized light.

[0128] Figure 6 C is a diagram representing the type of image light generated by the display panel 1. When the polarization control unit 5 emits P-polarized light, for example, the display panel 1 generates image light corresponding to the central field of view. When the polarization control unit 5 emits S-polarized light, for example, the display panel 1 emits image light corresponding to the peripheral field of view.

[0129] In this manner, the display panel 1 alternately generates image light corresponding to a first region (e.g., peripheral field of view) and image light corresponding to a second region (e.g., central field of view). At this time, crosstalk may occur when switching between different types of image light. Therefore, the image control unit 6 appropriately shuts down the display panel 1 at the timing when the image corresponding to the first region and the image corresponding to the second region are switched.

[0130] refer to Figure 7 To illustrate this point. Figure 7 This is a schematic diagram illustrating an operational example of an image display device 100 according to an embodiment of the present technology.

[0131] Figure 7 Figure A is a diagram illustrating an operational example of the polarization control unit 5. For example, the polarization control unit 5 alternately switches between P-polarized light and S-polarized light.

[0132] Figure 7 Figure B is a diagram showing an example of the operation of the display panel 1. The display panel 1 operates synchronously with the polarization control unit 5. The display panel 1 alternately generates a first image light (image light corresponding to the first region) L1 emitted as P-polarized light and a second image light (image light corresponding to the second region) emitted as S-polarized light.

[0133] At this time, as Figure 7 As shown in Figure A, the polarization direction does not switch instantaneously. As the intensity of the P-polarized light gradually decreases, the intensity of the S-polarized light gradually increases. Therefore, during the time that the display panel 1 is still generating the first image light L1, the intensity of the S-polarized light from the polarization control unit 5 increases in some cases. This can potentially lead to crosstalk.

[0134] Therefore, as Figure 7 As shown in Figure C, the image control unit 6 appropriately shuts down the display panel 1 at the timing of the switching between the first image light L1 and the second image light L2. In this example, the timing of the polarization control unit 5 emitting P-polarized light (see Figure C) is also considered. Figure 7 The timing of A) and the first image light L1 emitted from display panel 1 (see A) Figure 7Delay occurs between B) This generates a delay for display panel 1 driven with a 20% duty cycle. Display panel 1 is in an inactive state (non-light-emitting state) for 80% of the time.

[0135] Unless a specific technical contradiction arises, the description of the image display device according to the first embodiment of the present technology can be applied to other embodiments according to the present technology.

[0136] [2. Second embodiment of the present technology (Example 2 of an image display device)]

[0137] refer to Figure 8 To illustrate another embodiment of the image display device according to the present technology. Figure 8 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0138] like Figure 8 As shown, the display panel 1, polarization control unit 5, and polarization conversion unit 3 are stacked in the order in which image light passes. In the first embodiment, the image display device 100 includes two polarization conversion units 3. On the other hand, in the second embodiment, the image display device 100 includes one polarization conversion unit 3.

[0139] Furthermore, in the second embodiment, the optical system 2 has a diffractive lens based on geometric phase. For example, the diffractive lens may be a PBP (Pancharatnam-Berry phase) lens, etc. By using a diffractive lens based on geometric phase, the thickness of the image display device 100 can be reduced.

[0140] For example, display panel 1 generates image light corresponding to a second region (e.g., the central field of view). Polarization control unit 5 converts the image light with a polarization direction into P-polarized light. Polarization conversion unit 3 converts the P-polarized light into right-hand circularly polarized light. Optical system 2 converges the right-hand circularly polarized light. Thus, the observer can observe the image corresponding to the second region. That is, the image corresponding to the central field of view is displayed in the observer's central field of view.

[0141] At this point, when the image light is reflected by reflector 4, the right-handed circularly polarized light is converted into left-handed circularly polarized light. Because optical system 2 causes the left-handed circularly polarized light to diverge, the image corresponding to the central field of view is not displayed in the observer's peripheral field of view.

[0142] Next, the display panel 1 generates image light corresponding to the first region (e.g., peripheral field of view). The polarization control unit 5 converts the image light with a polarization direction into S-polarized light. The polarization conversion unit 3 converts the S-polarized light into left-handed circularly polarized light. When the image light is reflected by the reflector 4, the left-handed circularly polarized light is converted into right-handed circularly polarized light. The optical system 2 converges the right-handed circularly polarized light. Thus, the observer can observe the image corresponding to the first region. That is, the image corresponding to the peripheral field of view is displayed in the observer's peripheral field of view.

[0143] On the other hand, since optical system 2 diverges left-handed circularly polarized light, the image light reaching optical system 2 without being reflected by reflector 4 or the like is diverged by optical system 2. That is, the image corresponding to the peripheral field of view is not displayed in the observer's central field of view.

[0144] Unless a specific technical contradiction arises, the description of the image display device according to the second embodiment of the present technology can be applied to other embodiments according to the present technology.

[0145] [3. Third embodiment of the present technology (Example 3 of an image display device)]

[0146] refer to Figure 9 To illustrate another embodiment of the image display device according to the present technology. Figure 9 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0147] like Figure 9 As shown, reflector 4 is arranged between the pupil and optical system 2, and between optical system 2 and polarization control unit 5. Polarization conversion unit 3 is arranged between optical system 2 and polarization control unit 5. Optical system 2 includes: polarized light transmission unit 21, which selectively transmits linearly polarized light; and lens 22.

[0148] Each of the reflectors 4 arranged between the pupil and the optical system 2 and the corresponding one of the reflectors 4 arranged between the optical system 2 and the polarization control unit 5 can be integrally formed or can be separate. In this embodiment, the reflectors 4 are integrally formed.

[0149] According to this embodiment, the image light is reflected twice. For example, the image light emitted from the polarization control unit 5 is reflected by the reflector 4 arranged between the optical system 2 and the polarization control unit 5, passes through the optical system 2, is reflected by the reflector 4 arranged between the pupil and the optical system 2, and is guided to the pupil.

[0150] According to this embodiment, since the image light is reflected twice, inversion processing for the image corresponding to the surrounding vision becomes unnecessary. This reduces the delay caused by inversion processing.

[0151] Furthermore, since the reflector 4 is arranged between the pupil and the optical system 2, the image display device 100 can allow the observer to view an image with a wider field of view.

[0152] Note that since the polarization direction of the image light emitted by the polarization control unit 5 and the polarization direction transmitted by the polarized light transmission unit 21 are similar to those in the first embodiment, their description is omitted.

[0153] Unless a specific technical contradiction arises, the description of the image display device according to the third embodiment of the present technology can be applied to other embodiments according to the present technology.

[0154] [4. Fourth embodiment of the present technology (Example 4 of an image display device)]

[0155] refer to Figure 10 To illustrate another embodiment of the image display device according to the present technology. Figure 10 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0156] like Figure 10 As shown, reflector 4 is arranged between the pupil and optical system 2, and between optical system 2 and polarization control unit 5. Display panel 1, polarization control unit 5, and polarization conversion unit 3 are stacked in the order in which image light passes. Optical system 2 has a diffraction lens based on geometric phase.

[0157] Each of the reflectors 4 arranged between the pupil and the optical system 2 and the corresponding one of the reflectors 4 arranged between the optical system 2 and the polarization control unit 5 can be integrally formed or can be separated. In this embodiment, the reflectors 4 are separated.

[0158] According to this embodiment, the image light is reflected twice. Since its beneficial effects are similar to those in the third embodiment, its description is omitted.

[0159] Note that since the polarization direction of the image light emitted by the polarization control unit 5 and the polarization direction converged or diverged by the optical system 2 are similar to those in the second embodiment, their description is omitted.

[0160] Unless a specific technical contradiction arises, the description of the image display device according to the fourth embodiment of the present technology can be applied to other embodiments according to the present technology.

[0161] [5. Fifth embodiment of the present technology (Example 5 of an image display device)]

[0162] refer to Figure 11 To illustrate another embodiment of the image display device according to the present technology. Figure 11 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0163] like Figure 11 As shown, the reflector 4 is arranged at an angle relative to the vertical direction of the display panel 1. The optical system 2 includes: a polarized light transmission section 21 that selectively transmits linearly polarized light; and a lens 22.

[0164] To allow observers to view images with a wide field of view, the diameter of the lens 22 in the optical system 2 tends to increase. On the other hand, in recent years, there has been a tendency to use display panels 1 that have a large number of pixels while reducing size. In view of this trend, by arranging the reflector 4 at an angle relative to the vertical direction of the display panel 1, the space inside the image display device 100 can be used effectively, and the size of the device can be reduced.

[0165] When the width of the display panel 1 is s, the width of the reflector 4 is l, the length of the gap between the reflector 4 and the display panel 1 is q, and the tilt angle of the reflector 4 is β, the following mathematical expression (2) is appropriately satisfied.

[0166] l·sinβ+s / 2=(l·cosβ+q)·tan(2β)……(2)

[0167] By satisfying this mathematical expression, the peak brightness distribution near the center of display panel 1 is improved. As a result, image light from near the center of display panel 1 is more likely to reach the pupil.

[0168] Note that since the polarization direction of the image light emitted by the polarization control unit 5 and the polarization direction transmitted by the polarized light transmission unit 21 are similar to those in the first embodiment, their description is omitted.

[0169] Unless a specific technical contradiction arises, the description of the image display device according to the fifth embodiment of the present technology can be applied to other embodiments according to the present technology.

[0170] [6. Sixth embodiment of the present technology (Example 6 of an image display device)]

[0171] refer to Figure 12 To illustrate another embodiment of the image display device according to the present technology. Figure 12 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0172] like Figure 12 As shown, the display panel 1, polarization control unit 5, and polarization conversion unit 3 are stacked in the order in which image light passes. The optical system 2 has a diffraction lens based on geometric phase.

[0173] The reflector 4 is arranged at an angle relative to the vertical direction of the display panel 1. Since this beneficial effect is similar to that of the fifth embodiment, its description is omitted.

[0174] Note that since the polarization direction of the image light emitted by the polarization control unit 5 and the polarization direction converged or diverged by the optical system 2 are similar to those in the second embodiment, their description is omitted.

[0175] Unless a specific technical contradiction arises, the description of the image display device according to the sixth embodiment of the present technology can be applied to other embodiments according to the present technology.

[0176] [7. Seventh embodiment of the present technology (Example 7 of an image display device)]

[0177] refer to Figure 13 To illustrate another embodiment of the image display device according to the present technology. Figure 13 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0178] like Figure 13 As shown, the display panel 1 and the polarization control unit 5 are stacked in the order in which the image light passes through.

[0179] The optical system 2 includes a lens 22, a polarized light transmission section 21, and a reflection prevention section 23. The polarized light transmission section 21 and the reflection prevention section 23 are stacked. The reflection prevention section 23 is arranged on the side where the image light is incident.

[0180] The optical system 2 transmits a portion of the image light and reflects a portion of the image light toward the reflector 4. The polarization conversion unit 3 is arranged on the surface of the reflector 4 where the image light is incident.

[0181] Note that since the polarization direction of the image light emitted by the polarization control unit 5 and the polarization direction transmitted by the polarized light transmission unit 21 are similar to those in the first embodiment, their description is omitted.

[0182] According to this embodiment, the main ray is more likely to be guided to the pupil compared to the mode using a light guide plate.

[0183] Unless a specific technical contradiction arises, the description of the image display device according to the seventh embodiment of the present technology can be applied to other embodiments according to the present technology.

[0184] [8. Eighth embodiment of the present technology (Example 8 of an image display device)]

[0185] refer to Figure 14 To illustrate another embodiment of the image display device according to the present technology. Figure 14 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0186] like Figure 14 As shown, the display panel 1 and the polarization control unit 5 are stacked in the order in which the image light passes through.

[0187] The optical system 2 is integrally formed to include a polarization conversion unit 3 and a polarized light transmission unit 21. For example, the optical system 2 can be configured as a prism 24.

[0188] In prism 24, the incident and exit surfaces for image light are formed as free-form surfaces. The surface on which the polarization conversion unit 3 is arranged is a plane.

[0189] Note that since the polarization direction of the image light emitted by the polarization control unit 5 and the polarization direction transmitted by the polarized light transmission unit 21 are similar to those in the first embodiment, their description is omitted.

[0190] According to this embodiment, since the number of manufacturing steps is reduced, it is possible to improve manufacturing efficiency and reduce manufacturing costs.

[0191] Unless a specific technical contradiction arises, the description of the image display device according to the eighth embodiment of the present technology can be applied to other embodiments according to the present technology.

[0192] [9. Ninth embodiment of the present technology (Example 9 of an image display device)]

[0193] refer to Figure 15 To illustrate another embodiment of the image display device according to the present technology. Figure 15 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0194] like Figure 15 As shown, the display panel 1 and the polarization control unit 5 are stacked in the order in which the image light passes through.

[0195] The optical system 2 has a polarized light transmission section 21 and a lens 22. The polarized light transmission section 21 transmits a portion of the image light and reflects a portion of the image light toward the reflector 4.

[0196] For example, reflector 4 can be an axisymmetric curved surface mirror, etc. Reflector 4 reflects image light from polarization conversion unit 3. Reflector 4 reflects a portion of the image light towards optical system 2 and a portion of the image light towards the pupil. That is, according to this embodiment, the image light is reflected twice. Since its beneficial effects are similar to those in the third embodiment, its description is omitted.

[0197] Note that since the polarization direction of the image light emitted by the polarization control unit 5 and the polarization direction transmitted by the polarized light transmission unit 21 are similar to those in the first embodiment, their description is omitted.

[0198] Unless a specific technical contradiction arises, the description of the image display device according to the ninth embodiment of the present technology can be applied to other embodiments according to the present technology.

[0199] [10. Tenth embodiment of the present technology (Example 10 of an image display device)]

[0200] refer to Figure 16 To illustrate another embodiment of the image display device according to the present technology. Figure 16 This is a schematic diagram illustrating a configuration example of an image display device 100 according to an embodiment of the present technology.

[0201] like Figure 16 As shown, an optical element 8 that changes the direction of image light is arranged between the display panel 1 and the reflector 4. For example, the optical element 8 can be a prism, a diffractive optical element, etc. For example, the prism can be a V-block prism, etc. For example, the diffractive optical element can be a light deflector, such as a Pb phase deflector, a hologram, a grating, etc. A Pb phase deflector is a light deflector using liquid crystal, and its thickness can be reduced compared to a prism.

[0202] Additionally, a plate-shaped optical element 81 that transmits image light is arranged in the optical element 8. For example, the plate-shaped optical element 81 may include glass or the like.

[0203] According to this embodiment, the boundary between the image corresponding to the central field of view and the image corresponding to the peripheral field of view can be made less obvious. (Reference) Figure 17 To illustrate this point. Figure 17 This is a schematic diagram illustrating an example configuration of an optical element 8 according to an embodiment of the present technology.

[0204] like Figure 17 As shown, a V-shaped block prism is illustrated as an example of optical element 8. Image light is incident on optical element 8 from each of the display panel 1 and reflector 4. Optical element 8 combines the individual incident image lights and outputs them as a single beam. By employing this configuration, the boundary between the image corresponding to the central field of view and the image corresponding to the peripheral field of view can be made less pronounced.

[0205] Note, for example, that the focus position can be adjusted to make the boundaries less noticeable. The focus position can be defocused from display panel 1 to give the beam spot a certain width.

[0206] Unless a specific technical contradiction arises, the description of the image display device according to the tenth embodiment of the present technology can be applied to other embodiments according to the present technology.

[0207] Note that embodiments of this technology are not limited to the embodiments described above, and various changes can be made without departing from the spirit of this technology. The specific values, shapes, materials (including composition), etc., described in the various embodiments are examples, and these are not the only examples.

[0208] Alternatively, this technology can be configured as follows.

[0209] [1] An image display device, comprising:

[0210] Display panel, the display panel generates image light;

[0211] An optical system that transmits image light having a predetermined polarization direction and guides the image light having a predetermined polarization direction to the observer's pupil;

[0212] A reflector that reflects image light from the display panel that corresponds to a first region in the observer's field of view toward the optical system; and

[0213] A polarization control unit switches the polarization direction of the image light, wherein...

[0214] The polarization control unit alternately switches between the polarization direction of the image light corresponding to the first region and the polarization direction of the image light corresponding to the second region, which is different from the first region in the observer's field of vision.

[0215] [2] The image display device according to [1] further includes:

[0216] A polarization conversion unit that converts the polarization direction of image light from the display panel.

[0217] [3] According to the image display device described in [2], wherein,

[0218] The polarization conversion unit is arranged outside the display panel and in the vertical direction of the display panel, and

[0219] The polarization conversion unit and the reflector are stacked sequentially from the side where the image light is incident.

[0220] [4] The image display device according to any one of [1] to [3], wherein,

[0221] When the width of the display panel is s, the width of the reflector is l, the length of the gap between the reflector and the display panel is q, and the angle formed between the reflector and the line segment connecting the center of the display panel and the end of the reflector on one side of the optical system is α, the mathematical expression (1) is satisfied:

[0222] s / 2=(l+q)·tan(α)……(1).

[0223] [5] The image display apparatus according to any one of [1] to [4], wherein,

[0224] The optical system includes: a polarized light transmission section that selectively transmits linearly polarized light; and a lens.

[0225] [6] The image display device according to any one of [2] to [5], wherein,

[0226] The display panel, the polarization control unit, and the polarization conversion unit are stacked in the order in which image light passes through.

[0227] [7] The image display apparatus according to any one of [1] to [6], wherein,

[0228] The optical system has a diffractive lens based on geometric phase.

[0229] [8] The image display apparatus according to any one of [1] to [7], wherein,

[0230] The reflector is arranged between the pupil and the optical system, and between the optical system and the polarization control unit.

[0231] [9] The image display device according to [8], wherein,

[0232] The optical system includes: a polarized light transmission section that selectively transmits linearly polarized light; and a lens; and

[0233] The polarization conversion unit, which converts the polarization direction of image light from the display panel, is arranged between the optical system and the polarization control unit.

[0234]

[10] The image display apparatus according to any one of [8] or [9], wherein,

[0235] The optical system has a diffractive lens based on geometric phase.

[0236]

[11] The image display apparatus according to any one of [1] to

[10] , wherein,

[0237] The reflector is arranged at an angle relative to the vertical direction of the display panel.

[0238]

[12] According to the image display device described in

[11] , wherein,

[0239] When the width of the display panel is s, the width of the reflector is l, the length of the gap between the reflector and the display panel is q, and the tilt angle of the reflector is β, the mathematical expression (2) is satisfied:

[0240] l·sinβ+s / 2=(l·cosβ+q)·tan(2β)……(2).

[0241]

[13] The image display apparatus according to any one of [1] to

[12] , wherein,

[0242] The optical system transmits a portion of the image light and reflects a portion of the image light toward the reflector.

[0243]

[14] The image display apparatus according to any one of [1] to

[13] , wherein,

[0244] The optical system is integrally formed as follows: a polarization conversion unit that converts the polarization direction of image light from the display panel; and a polarized light transmission unit that selectively transmits linearly polarized light.

[0245]

[15] The image display apparatus according to any one of [1] to

[14] , wherein,

[0246] The optical system transmits a portion of the image light and reflects a portion of the image light toward the reflector.

[0247] The reflector reflects a portion of the image light toward the optical system and a portion of the image light toward the pupil.

[0248]

[16] The image display apparatus according to any one of [1] to

[15] , wherein,

[0249] Optical elements that change the direction of image light are arranged between the display panel and the reflector.

[0250]

[17] The image display device according to any one of [1] to

[16] further includes:

[0251] The image control unit synchronizes the timing of the display panel switching image light with the timing of the polarization control unit switching polarization direction.

[0252]

[18] The image display device according to

[17] , wherein,

[0253] The image control unit inverts the image corresponding to the first region.

[0254]

[19] The image display device according to

[17] or

[18] , wherein,

[0255] The image control unit shuts down the display panel at a timed interval when the image corresponding to the first region and the image corresponding to the second region are switched.

[0256]

[20] The image display apparatus according to any one of [1] to

[19] , wherein,

[0257] The first area is the surrounding view, and

[0258] The second area is the central field of vision.

[0259] Reference tag list

[0260] 100 Image display devices

[0261] 1 Display Panel

[0262] 2 Optical System

[0263] 21. Polarized light transmission section

[0264] 22 Lenses

[0265] 23 Anti-reflection section

[0266] 3 Polarization conversion section

[0267] 4. Reflectors

[0268] 5. Polarization Control Unit

[0269] 51 LCD

[0270] 52 Transparent Electrode

[0271] 53 Polarizer

[0272] 6. Image Control Unit

[0273] 7 Power Supply

[0274] 8 Optical Components

Claims

1. An image display device, comprising: Display panel, the display panel generates image light; An optical system that transmits image light having a predetermined polarization direction and guides the image light having a predetermined polarization direction to the observer's pupil; A reflector that reflects image light from the display panel that corresponds to a first region in the observer's field of vision toward the optical system; as well as A polarization control unit switches the polarization direction of the image light, wherein... The polarization control unit alternately switches between the polarization direction of the image light corresponding to the first region and the polarization direction of the image light corresponding to the second region, which is different from the first region in the observer's field of vision.

2. The image display device according to claim 1, further comprising: A polarization conversion unit that converts the polarization direction of image light from the display panel.

3. The image display device according to claim 2, wherein, The polarization conversion unit is arranged outside the display panel and in the vertical direction of the display panel, and The polarization conversion unit and the reflector are stacked sequentially from the side where the image light is incident.

4. The image display device according to claim 1, wherein, When the width of the display panel is s, the width of the reflector is l, the length of the gap between the reflector and the display panel is q, and the angle formed between the reflector and the line segment connecting the center of the display panel and the end of the reflector on one side of the optical system is α, the mathematical expression (1) is satisfied: s / 2=(l+q)·tan(α)……(1).

5. The image display device according to claim 1, wherein, The optical system includes: a polarized light transmission section that selectively transmits linearly polarized light; and a lens.

6. The image display device according to claim 2, wherein, The display panel, the polarization control unit, and the polarization conversion unit are stacked in the order in which image light passes through.

7. The image display device according to claim 1, wherein, The optical system has a diffractive lens based on geometric phase.

8. The image display device according to claim 1, wherein, The reflector is arranged between the pupil and the optical system, and between the optical system and the polarization control unit.

9. The image display device according to claim 8, wherein, The optical system includes: a polarized light transmission section, which selectively transmits linearly polarized light; And lenses, and The polarization conversion unit, which converts the polarization direction of image light from the display panel, is arranged between the optical system and the polarization control unit.

10. The image display device according to claim 8, wherein, The optical system has a diffractive lens based on geometric phase.

11. The image display device according to claim 1, wherein, The reflector is arranged at an angle relative to the vertical direction of the display panel.

12. The image display device according to claim 11, wherein, When the width of the display panel is s, the width of the reflector is l, the length of the gap between the reflector and the display panel is q, and the tilt angle of the reflector is β, the mathematical expression (2) is satisfied: l·sinβ+s / 2=(l·cosβ+q)·tan(2β)……(2).

13. The image display device according to claim 1, wherein, The optical system transmits a portion of the image light and reflects a portion of the image light toward the reflector.

14. The image display device according to claim 1, wherein, The optical system is integrally formed as follows: a polarization conversion unit that converts the polarization direction of image light from the display panel; and a polarized light transmission unit that selectively transmits linearly polarized light.

15. The image display device according to claim 1, wherein, The optical system transmits a portion of the image light and reflects a portion of the image light toward the reflector. The reflector reflects a portion of the image light toward the optical system and a portion of the image light toward the pupil.

16. The image display device according to claim 1, wherein, Optical elements that change the direction of image light are arranged between the display panel and the reflector.

17. The image display device according to claim 1, further comprising: The image control unit synchronizes the timing of the display panel switching image light with the timing of the polarization control unit switching polarization direction.

18. The image display device according to claim 17, wherein, The image control unit inverts the image corresponding to the first region.

19. The image display device according to claim 17, wherein, The image control unit shuts down the display panel at a timed interval when the image corresponding to the first region and the image corresponding to the second region are switched.

20. The image display device according to claim 1, wherein, The first area is the surrounding view, and The second area is the central field of vision.

Images