Image display device and image display method

Abstract

This disclosure provides an image display device that improves image reproducibility and / or enhances image visibility through simple configuration. The image display device according to this technology includes: a light source system comprising at least one laser light source and emitting laser light modulated according to image information; a branching optical path selection system including an optical path branching unit that divides the optical path of the laser light from the light source system into multiple branching optical paths; and an optical path combining system that combines the multiple branching optical paths. The branching optical path selection system further includes a first optical processing system that selects at least one branching optical path from the multiple branching optical paths as the branching optical path through which the laser light travels from the optical path branching unit, and performs optical processing on the laser light traveling through some of the branching optical paths.

Description

Technical Field

[0001] The technology disclosed herein (hereinafter also referred to as "the technology") relates to image display devices and image display methods. Background Technology

[0002] Traditionally, an image display device is known that directs light from a light source to allow visual recognition of an image (see, for example, Patent Documents 1 to 3).

[0003] Reference List

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-32631

[0006] Patent Document 2: Japanese Patent Application Publication No. 2015-162526

[0007] Patent Document 3: Japanese Patent Application Publication No. 2008-309827 Summary of the Invention

[0008] The problem to be solved

[0009] However, traditional image display devices have room for improvement in terms of image reproducibility and / or image visibility through simple configuration.

[0010] Therefore, the main objective of this technology is to provide an image display device that can improve image reproducibility and / or improve image visibility through simple configuration.

[0011] Solution to the problem

[0012] This technology provides an image display device, including: A light source system, the light source system including at least one laser light source, the light source system being configured to emit laser light modulated according to image information; A branched optical path selection system, the branched optical path selection system including an optical path branching section configured to branch the optical path of a laser emitted from the light source system into multiple branched optical paths; and An optical path combining system, configured to combine the multiple branch optical paths, wherein... The branch optical path selection system selects at least one branch optical path from the plurality of branch optical paths as the branch optical path through which the laser travels from the branch portion of the optical path. The image display device further includes a first optical processing system configured to perform optical processing on a laser traveling along a first branch optical path of the plurality of branch optical paths.

[0013] The branch optical path selection system can perform selection based on the image information.

[0014] The excitation intensity of the laser source in the light source system can exceed the laser threshold, and the first optical processing system may include an optical attenuation section configured to attenuate the laser traveling along the first branch optical path.

[0015] When the brightness of the image information is within a first brightness range less than or equal to a predetermined value, the branch optical path selection system can select the first branch optical path as the branch optical path for the laser to travel from the branch portion of the optical path. And when the brightness of the image information is within a second brightness range greater than the predetermined value, the branch optical path selection system can select the second branch optical path from the plurality of branch optical paths as the branch optical path for the laser to travel from the branch portion of the optical path.

[0016] The first optical processing system may include a detour section configured to detour the laser traveling along the first branch optical path.

[0017] When the laser is modulated frame by frame according to the first pixel region of the image information, the branch optical path selection system can select the first branch optical path as the branch optical path for the laser to travel from the branch portion of the optical path. And when the laser is modulated frame by frame according to the second pixel region of the image information, the branch optical path selection system can select the second branch optical path from the multiple branch optical paths as the branch optical path for the laser to travel from the branch portion of the optical path.

[0018] The branch optical path selection system can alternately perform operations at least frame by frame, selecting the first branch optical path as the branch optical path for the laser to travel from the branch portion of the optical path and selecting the second branch optical path from the plurality of branch optical paths as the branch optical path for the laser to travel from the branch portion of the optical path.

[0019] The image display device may further include: a second branch optical path selection system, the second branch optical path selection system including a second optical path branching portion, the second optical path branching portion being configured to branch an optical path obtained by combining the multiple branch optical paths in the optical path combining system into multiple other branch optical paths; and a second optical path combining system, the second optical path combining system being configured to combine the multiple other branch optical paths, wherein the second branch optical path selection system can select at least one branch optical path from the multiple other branch optical paths based on the image information as another branch optical path for the laser to travel from the second optical path branching portion, and the image display device may further include a second optical processing system, the second optical processing system being configured to perform optical processing on the laser traveling along a third branch optical path among the multiple other branch optical paths.

[0020] The excitation intensity of the laser source in the light source system can exceed the laser threshold, and the second optical processing system may include an optical attenuation section configured to attenuate the laser traveling along the third branch optical path.

[0021] When the brightness of the image information is within a first brightness range less than or equal to a predetermined value, the other branch optical path selection system can select the third branch optical path as another branch optical path for the laser to travel from the branch portion of the other optical path. And when the brightness of the image information is within a second brightness range greater than the predetermined value, the other branch optical path selection system can select the fourth branch optical path from the plurality of other branch optical paths as another branch optical path for the laser to travel from the branch portion of the other optical path.

[0022] The second optical processing system may include a detour section configured to detour the laser traveling along the third branch optical path.

[0023] When the laser is modulated frame by frame according to the first pixel region of the image information, the other branch optical path selection system can select the third branch optical path as another branch optical path for the laser to travel from the branch portion of the other optical path. And when the laser is modulated frame by frame according to the second pixel region of the image information, the other branch optical path selection system can select the fourth branch optical path from the plurality of other branch optical paths as another branch optical path for the laser to travel from the branch portion of the other optical path.

[0024] The branch optical path selection system can alternately perform operations at least frame by frame, selecting the first branch optical path as the branch optical path for the laser to travel from the branch portion of the optical path and selecting the second branch optical path from the plurality of branch optical paths as the branch optical path for the laser to travel from the branch portion of the optical path.

[0025] The branching optical path selection system may include a polarization controllable element capable of changing the polarization state of the laser emitted from the light source system, and at least the optical path branching portion and the optical path combining system may include a polarization beam splitter.

[0026] The other branch optical path selection system may include a polarization controllable element capable of changing the polarization state of the laser emitted from the optical path combining system, and the other optical path branch portion and at least the other optical path branch portion in the optical path combining system may include a polarization beam splitter.

[0027] The at least one laser source may include multiple laser sources with different emission wavelengths, and the branch optical path selection system, the optical path combining system and the first optical processing system may be provided for each laser source.

[0028] The optical path branch portion may include an element in which multiple pixels are arranged in a two-dimensional manner.

[0029] The other optical path branch may include an element in which multiple pixels are arranged in a two-dimensional manner.

[0030] This technology provides an image display method, including: Emit laser light modulated according to image information; Based on the image information, at least one branch optical path is selected from multiple branch optical paths obtained by branching the optical path as the branch optical path for the laser to travel; When a first branch optical path is selected from the plurality of branch optical paths as the branch optical path along which the laser travels, a first optical processing is performed on the laser traveling along the first branch optical path; and The multiple branch optical paths are synthesized.

[0031] The image display method may further include: selecting at least one branch optical path from a plurality of other branch optical paths obtained by branching a synthesized optical path obtained by synthesizing the plurality of branch optical paths as another branch optical path along which the laser travels; when a third branch optical path is selected from the plurality of other branch optical paths as another branch optical path along which the laser travels, performing a second optical processing on the laser traveling along the third branch optical path; and synthesizing the plurality of other branch optical paths. Attached Figure Description

[0032] Figure 1 This is a graph showing the current-light output characteristics of a typical laser source.

[0033] Figure 2 This is a diagram illustrating the configuration of an image display device according to Example 1 of an embodiment of the present technology.

[0034] Figure 3 This is a block diagram illustrating the function of an image display device according to an embodiment of the present technology, Example 1.

[0035] Figure 4 It is a graph showing the current-light intensity characteristics of light passing through the light attenuation section and light not passing through the light attenuation section.

[0036] Figure 5 This is a flowchart describing how the image display device of Example 1, an embodiment of the present technology, operates.

[0037] Figure 6 This is a diagram illustrating the configuration of an image display device according to Example 2 of an embodiment of the present technology.

[0038] Figure 7 This is a block diagram illustrating the function of an image display device according to an embodiment of the present technology, Example 2.

[0039] Figure 8 This is a flowchart describing how the image display device of Example 2, an embodiment of the present technology, operates.

[0040] Figure 9 This is a diagram used to describe the operation of an image display device according to Example 2 of an embodiment of the present technology.

[0041] Figure 10 This is a diagram illustrating the configuration of an image display device according to Example 3 of an embodiment of the present technology.

[0042] Figure 11 This is a block diagram illustrating the function of an image display device according to Example 3 of an embodiment of the present technology.

[0043] Figure 12 This is a flowchart describing how the image display device of Example 3, an embodiment of the present technology, operates.

[0044] Figure 13 This is a diagram illustrating the configuration of an image display device according to Example 4 of an embodiment of the present technology.

[0045] Figure 14 This is a block diagram illustrating the function of an image display device according to Example 4 of an embodiment of the present technology.

[0046] Figure 15 This is a diagram illustrating the configuration of an image display device according to Example 5 of an embodiment of the present technology.

[0047] Figure 16 This is a block diagram illustrating the function of an image display device according to Example 5 of an embodiment of the present technology.

[0048] Figure 17 This is a diagram illustrating the configuration of an image display device of a variant of Example 5 according to an embodiment of the present technology.

[0049] Figure 18 This is a diagram illustrating the configuration of an image display device according to Example 6 of an embodiment of the present technology.

[0050] Figure 19 This is a block diagram illustrating the function of an image display device according to Example 6 of an embodiment of the present technology.

[0051] Figure 20 This is a diagram illustrating the configuration of an image display device of a variant of Example 6 according to an embodiment of the present technology.

[0052] Figure 21 This is a diagram illustrating the configuration of an image display device according to Example 7 of an embodiment of the present technology.

[0053] Figure 22 This is a block diagram illustrating the function of an image display device according to an embodiment of the present technology, Example 7.

[0054] Figure 23 This is a diagram illustrating the configuration of an image display device of a variant of Example 7 according to an embodiment of the present technology.

[0055] Figure 24 This is a diagram illustrating the configuration of an image display device of a variant of Example 1 according to an embodiment of the present technology.

[0056] Figure 25 This is a diagram illustrating the configuration of an image display device of a variant of Example 2 according to an embodiment of the present technology.

[0057] Figure 26 This is a diagram illustrating the configuration of an image display device of a variant of Example 4 according to an embodiment of the present technology. Detailed Implementation

[0058] Preferred embodiments of the present technology will be described in detail below with reference to the accompanying drawings. Note that components with substantially the same functional configuration are designated by the same reference numerals in this specification and the drawings to avoid repetition in the description. The embodiments described below illustrate representative embodiments of the present technology and should not be used to narrowly interpret the scope of the present technology based on these embodiments. In this specification, even when multiple effects are described as exhibited by the image display device and image display method according to the present technology, the image display device and image display method according to the present technology need only exhibit at least one effect. The effects described in this specification are merely examples and not limiting, and other effects can be achieved.

[0059] Furthermore, the descriptions will be given in the following order.

[0060] 0. Introduction

[0061] 1. An image display device according to Example 1 of the embodiments of the present technology.

[0062] 2. An image display device according to Example 2 of the embodiments of the present technology.

[0063] 3. An image display device according to Example 3 of the embodiments of the present technology.

[0064] 4. An image display device according to Example 4 of the embodiments of the present technology.

[0065] 5. An image display device according to Example 5 of the embodiments of the present technology.

[0066] 5.5. A variant of Example 5 of the embodiments of the present technology, showing an image display device.

[0067] 6. An image display device according to Example 6 of an embodiment of the present technology.

[0068] 6.5. A variant of Example 6 of the embodiments of the present technology, showing an image display device.

[0069] 7. An image display device according to Example 7 of an embodiment of the present technology.

[0070] 7.5. A variant of Example 7 of an embodiment of the present technology, an image display device

[0071] 8. Variations of this technology

[0072] <0. Introduction>

[0073] Traditionally, laser beam scanning image display devices achieve brightness levels by utilizing the current-to-light output (IL) characteristics of a laser light source. However, as... Figure 1 As shown in the magnified partial view, the problem with the IL characteristics of the laser source is that linearity disappears, especially at or below the threshold current Ith, and the light output becomes unstable depending on laser conditions such as temperature. Furthermore, this instability also leads to color variations in low-brightness regions due to the fact that the characteristics change with wavelength.

[0074] Traditionally, methods have been proposed to simply implement dynamic attenuation besides grayscale representation. Methods for dynamically changing light intensity include those using polarization or diffraction; however, these methods suffer from the problem that light attenuation varies with wavelength. That is, there is the issue of light attenuation varying with ambient temperature, and the dynamic range of attenuation varies with wavelength. Therefore, there has traditionally been room for improvement in image reproducibility.

[0075] In addition, traditionally, the expectation has been to improve image visibility with simple configuration.

[0076] Therefore, as a result of focused research, the inventors have developed an image display device according to the present technology that is capable of improving image reproducibility and / or improving image visibility with a simple configuration.

[0077] Specifically, for example, in an image display device according to the present invention, by setting the excitation of the laser source to a relatively high level (e.g., above the laser threshold) and switching the laser's optical path for attenuation according to image information, a large optical attenuation of, for example, 20 dB to 40 dB can be obtained, thereby improving reproducibility in low-brightness regions. Furthermore, in an image display device according to the present invention, by switching the laser's optical path between optical paths of different optical path lengths according to image information, image resolution can be partially or temporarily increased to improve visibility.

[0078] <1. Image display device of Example 1 according to an embodiment of the present technology>

[0079] (Configuration of image display devices)

[0080] An example image display device according to an embodiment of the present technology will be described with reference to the accompanying drawings. Figure 2 This is a diagram illustrating the configuration of the image display device 10 according to Example 1 of an embodiment. Figure 3 This is a block diagram illustrating the function of the image display device 10 according to Example 1 of an embodiment. Figure 4 This is a graph showing the current-light intensity characteristics of light passing through the light attenuation section 501 and light not passing through the light attenuation section 501.

[0081] The image display device 10 is designed to provide users with, for example, augmented reality (AR), virtual reality (VR), etc.

[0082] The image display device 10 is used, for example, as a head-mounted display (HMD), which is used by being worn on a user's head. An HMD is also referred to, for example, as eyeglasses. As an example, the image display device 10 is mounted on a support structure (e.g., an eyeglass frame). In the following description, we will assume that the eyeglass frame, as an example of the support structure, is worn on a user's head.

[0083] As an example, such as Figure 2 As shown, the image display device 10 includes a light source system 100, a branch optical path selection system 200, an optical path combining system 600, and an optical attenuation section 501 (first optical processing system). The image display device 10 also includes, for example, a deflector 701, an eyepiece 801, and a control device 1100.

[0084] As an example, such as Figure 3As shown, the light source system 100 includes at least one laser light source 101, which emits laser light modulated according to image information. The light source system 100 also includes a light source driving unit 102 (laser driver) for driving the laser light source 101.

[0085] Examples of laser source 101 include semiconductor lasers, such as laser diodes (LDs) (edge-emitting lasers: EELs) and vertical-cavity surface-emitting lasers (VCSELs) (surface-emitting lasers: SELs), as well as solid-state lasers, such as solid-state lasers excited by semiconductor lasers. That is, laser source 101 can be electrically excited or optically excited.

[0086] The light source driving unit 102 includes, for example, transistors and capacitors. The light source driving unit 102 is controlled by the control device 1100. The image information mentioned above is input from the external device 2000 to the control device 1100.

[0087] As an example, such as Figure 2 As shown, the branch optical path selection system 200 includes a first polarization beam splitter 202, which serves as an optical path branching part that branches the optical path of the laser emitted from the light source system 100 into multiple (e.g., two) branch optical paths (e.g., the first branch optical path BOP1 and the second branch optical path BOP2).

[0088] The branch optical path selection system 200 selects at least one branch optical path from multiple (e.g., two) branch optical paths (first branch optical path BOP1 and second branch optical path BOP2) based on image information as the branch optical path along which the laser travels from the first polarization beam splitter 202.

[0089] As an example, such as Figure 2 and Figure 3 As shown, the branch optical path selection system 200 includes a polarization controllable element 201 capable of changing the polarization state of laser light emitted from the light source system 100. The polarization controllable element 201 is, for example, an electro-optic element (EO element). An EO element is an element capable of rotating the polarization plane of a laser by changing its polarization direction through the application of a voltage. The polarization controllable element 201 is arranged in the optical path of the laser light between the light source system 100 and the first polarization beam splitter 202, and converts the laser light emitted from the light source system 100 (e.g., linearly polarized light) into first or second linearly polarized light with polarization directions orthogonal to each other. The polarization controllable element 201 is controlled by a control device 1100. Note that a liquid crystal retarder can be used instead of an EO element as the polarization controllable element 201. The liquid crystal retarder operates in a similar manner to the EO element. Furthermore, the polarization controllable element 201 can mechanically rotate a polarizer or phase plate (e.g., a half-wave plate).

[0090] As an example, the first polarization beam splitter 202 reflects first linearly polarized light converted from laser light emitted from the light source system 100 by the polarization controllable element 201 to the first branch optical path BOP1. As an example, the first polarization beam splitter 202 transmits second linearly polarized light converted from laser light emitted from the light source system 100 by the polarization controllable element 201 to the second branch optical path BOP2.

[0091] The optical path combining system 600 combines a first branch optical path BOP1 and a second branch optical path BOP2. The optical path combining system 600 includes a half-wave plate 601 as a first delayer, a half-wave plate 602 as a second delayer, and a second polarization beam splitter 603 as the optical path combining part. Each half-wave plate converts incident linearly polarized light into linearly polarized light with a polarization direction orthogonal to the polarization direction of the incident linearly polarized light. The second polarization beam splitter 603 is essentially the same as the first polarization beam splitter 202.

[0092] Note that the optical path combining system 600 may include a half-mirror as a beam splitter instead of a second polarization beam splitter 603. This configuration eliminates the need for a first and a second retarder. Furthermore, the second polarization beam splitter 603 can reflect light traveling along the first branch optical path BOP1 and transmit light traveling along the second branch optical path BOP2 to combine the light.

[0093] As an example, a reflector 301, an optical attenuation section 501, and a half-wave plate 601 are arranged sequentially on the first branch optical path BOP1, starting from the first polarization beam splitter 202. The order of the reflector 301, the optical attenuation section 501, and the half-wave plate 601 arranged on the first branch optical path BOP1 can be changed as needed.

[0094] As an example, the optical attenuation section 501 applies optical attenuation processing as an optical treatment to the laser traveling along the first branch optical path BOP1. The optical attenuation section 501 includes a neutral density (ND) filter, a diffraction grating, etc. Broadly speaking, the diffraction grating includes not only diffractive optical elements (DOEs) but also holographic optical elements (HOEs). The optical attenuation section 501 can provide, for example, high optical attenuation of 20 dB to 40 dB. The optical attenuation section 501 can provide variable optical attenuation.

[0095] The first linearly polarized light reflected from the first polarization beam splitter 202 to the first branch optical path BOP1 is reflected by the mirror 301 toward the optical attenuation section 501. The first linearly polarized light incident on the optical attenuation section 501 is attenuated by the optical attenuation section 501 and then enters the half-wave plate 601. The first linearly polarized light incident on the half-wave plate 601 is converted into second linearly polarized light by the half-wave plate 601 and then enters the second polarization beam splitter 603.

[0096] As an example, a reflector 401 and a half-wave plate 602 are arranged sequentially from one side of the first polarizing beam splitter 202 on the second branch optical path BOP2. The order of the reflector 401 and the half-wave plate 602 arranged on the second branch optical path BOP2 can be reversed.

[0097] The second linearly polarized light transmitted through the first polarization beam splitter 202 to the second branch optical path BOP2 is reflected by the reflector 401 toward the half-wave plate 602. The second linearly polarized light incident on the half-wave plate 602 is converted into first linearly polarized light by the half-wave plate 602, and then enters the second polarization beam splitter 603.

[0098] A second linearly polarized light incident on the second polarization beamsplitter 603 via the first branch optical path BOP1 is transmitted through the second polarization beamsplitter 603. A first linearly polarized light incident on the second polarization beamsplitter 603 via the second branch optical path BOP2 is reflected by the second polarization beamsplitter 603. The second linearly polarized light transmitted through the second polarization beamsplitter 603 and the first linearly polarized light reflected by the second polarization beamsplitter 603 enter the deflector 701 via a common optical path (the combined optical path of the first branch optical path BOP1 and the second branch optical path BOP2). The deflector 701 deflects each incident linearly polarized light and performs a two-dimensional scan of the retina of the eyeball EB via the eyepiece 801. This allows the user to visually identify the image corresponding to the image information. The deflector 701 includes, for example, a combination of dual-axis movable mirrors or a single-axis movable mirror, such as a MEMS mirror or a galvanometer mirror. The deflector 701 is controlled by a control device 1100.

[0099] As an example, such as Figure 3 As shown, the control device 1100 includes a display control unit 1001, an image information input unit 1002, a modulation signal generation unit 1003, a deflector control unit 1004, a brightness determination unit 1005, and a branch optical path selection unit 1006. The control device 1100 is implemented in hardware, which includes, for example, a central processing unit (CPU) and a field-programmable gate array (FPGA) chipset.

[0100] The image information input unit 1002 receives image information (image data) transmitted from an external device 2000 (e.g., a smartphone, personal computer, camera, etc.). The communication connection between the image information input unit 1002 and the external device 2000 can be established via a wired or wireless connection.

[0101] The display control unit 1001 starts to generate a synchronization control signal based on the input of image information in the image information input unit 1002, and sends the synchronization control signal to the modulation signal generation unit 1003 and the deflector control unit 1004.

[0102] After receiving the synchronization control signal, the modulation signal generation unit 1003 generates a modulation signal (pulse signal) for modulating the drive of the laser light source 101 based on the image information received from the image information input unit 1002, and applies the modulation signal to the light source drive unit 102. The light source drive unit 102 generates a drive current (pulse current) to be applied to the laser light source 101 in response to the applied modulation signal. The light source drive unit 102 is configured to adjust so that the excitation intensity of the laser light source 101 exceeds the laser threshold, that is, the magnitude of the drive current exceeds the threshold current Ith (see Figure 4 ).

[0103] After receiving the synchronization control signal, the deflector control unit 1004 generates a drive signal (pulse signal) for driving the deflector 701, and applies the drive signal to the deflector 701. The deflector 701 performs laser beam scanning (e.g., raster scanning) in response to the applied drive signal. Note that the deflector control unit 1004 may be separated from the control device 1100.

[0104] The brightness determination unit 1005 determines whether the brightness of the image information is within a first brightness range (low brightness range) less than or equal to a predetermined value or within a second brightness range (high brightness range) greater than the predetermined value, and sends the determination result to the branch optical path selection unit 1006. The predetermined value is the value corresponding to Figure 4 shown in. The first brightness range is the brightness range corresponding to the light intensity range from P1 to P2 (P1 < P2) in Figure 4 . The second brightness range is the brightness range corresponding to the light intensity range from P2 to P3 (P2 << P3) in Figure 4 . P1 represents the light intensity of the laser emitted at the threshold current Ith and passing through the light attenuation part 501. P2 represents the light intensity of the laser emitted at the threshold current Ith and not passing through the light attenuation part 501.

[0105] The branch optical path selection unit 1006 is part of the branch optical path selection system 200. When the brightness of the image information is within a first brightness range (low brightness range), it selects a first branch optical path BOP1 as the branch optical path for the laser to travel from the first polarization beam splitter 202. When the brightness of the image information is within a second brightness range (high brightness range), it selects a second branch optical path BOP2 as the branch optical path for the laser to travel from the first polarization beam splitter 202. When selecting the first branch optical path BOP1, the branch optical path selection unit 1006 applies a first voltage signal (e.g., a high-level signal) to the polarization controllable element 201 to convert the laser emitted from the light source system 100 into first linearly polarized light. When selecting the second branch optical path BOP2, the branch optical path selection unit 1006 applies a second voltage signal (e.g., a low-level signal) to the polarization controllable element 201 to convert the laser emitted from the light source system 100 into second linearly polarized light. Note that, as an example, the second brightness range is wider than the first brightness range. In other words, as an example, the light intensity range from P2 to P3 is wider than the light intensity range from P1 to P2.

[0106] like Figure 4 As shown, when the first branch optical path BOP1 is selected, the current-intensity characteristic of the laser passing through the optical attenuation section 501 is stable, wherein as the current (horizontal axis) decreases from I... th Increase to I max The light intensity increases linearly from P1 to P2 with a gentle slope. Therefore, the brightness of image information within the first brightness range (low brightness range) can be accurately reproduced. Furthermore, in the current-light intensity characteristics, as an example, the light intensity range from P1 to P2 corresponds to the change in I... th To I max The current range is greater than the conventional current range corresponding to the light intensity range from P1 to P2 (and) Figure 4 The horizontal distance (the distance on the horizontal axis corresponding to the vertical distance between P1 and P2 indicated by the double-dotted line) is wide; therefore, the number of gray levels in the low brightness range can be increased.

[0107] Figure 4 The single-dotted line in the figure indicates the assumption that the current is less than or equal to the threshold current I. th The current-light intensity characteristics of the laser emitted by the light and passing through the light attenuation section 501 are shown, but it can be seen that the current-light intensity characteristics are unstable. Figure 4 The double-dotted line in the figure indicates the assumption that the current is less than or equal to the threshold current I. th The current-light intensity characteristics of the laser emitted without passing through the light attenuation section 501 are observed, but it can be seen that the current-light intensity characteristics are unstable. Furthermore, as mentioned above, when the current is less than or equal to the threshold current I... thAt this time, the laser source does not emit laser light and only produces low-intensity light as the applied current increases. Since this light is not laser light, a stable light intensity and wavelength cannot be obtained. When the current applied to the laser source exceeds the threshold current I... th At this point, the laser begins to emit light, and the intensity of the light increases proportionally to the applied current. Traditionally, for safety reasons, the light intensity is kept at a certain level during high grayscale displays; therefore, non-laser lasers with unstable intensity are used during the low brightness range for displaying image information.

[0108] On the other hand, in the image display device 10, the light used to display image information in the low brightness range (first brightness range) is attenuated by the light attenuation portion 501; therefore, light with a stable intensity generated by laser emission (laser) can be used to display the low brightness range.

[0109] like Figure 4 As shown, when the second branch optical path BOP2 is selected, the IL characteristic of the laser source is stable, wherein as the current decreases from I... th Increase to I max The light intensity increases linearly from P2 to P3 with a steep slope. Therefore, the brightness of image information within the second brightness range (high brightness range) can be accurately reproduced. The light intensity of the second branch optical path BOP2 can be greater than that of P2.

[0110] (Operation of image display devices)

[0111] In the following text, reference will be made to Figure 5 Describe the operation of the image display device 10. Figure 5 The flowchart is based on the processing algorithm executed by the control device 1100. The operation of the image display device 10 represents the image display method using the image display device 10.

[0112] In the first step S1, the image information input unit 1002 sequentially receives the input of image information (image data) sent from the external device 2000, sends an input timing signal to the display control unit 1001 for each input, and sequentially sends the input image information to the modulation signal generation unit 1003 and the brightness determination unit 1005.

[0113] In the next step S2, the brightness determination unit 1005 determines whether the brightness of the image information is within a first brightness range (low brightness range), that is, whether the brightness of the image information is within the first brightness range or within a second brightness range (high brightness range). When the determination is affirmative, the process proceeds to step S3, and when the determination is negative, the process proceeds to step S4.

[0114] In step S3, the branch optical path selection unit 1006 selects the first branch optical path BOP1 as the branch optical path along which the laser travels from the first polarization beam splitter 202. Specifically, the branch optical path selection unit 1006 applies a first voltage signal to the polarization controllable element 201 to convert the laser emitted from the light source system 100 into first linearly polarized light. After executing step S3, the process proceeds to step S5.

[0115] In step S4, the branch optical path selection unit 1006 selects the second branch optical path BOP2 as the branch optical path along which the laser travels from the first polarization beam splitter 202. Specifically, the branch optical path selection unit 1006 applies a second voltage signal to the polarization controllable element 201 to convert the laser emitted from the light source system 100 into second linearly polarized light. After executing step S4, the process proceeds to step S5.

[0116] In step S5, the display control unit 1001 drives the laser source 101 and the deflector 701 according to the image information. Specifically, the display control unit 1001 sends a synchronization control signal to the modulation signal generation unit 1003 and the deflector control unit 1004. After receiving the synchronization control signal, the modulation signal generation unit 1003 generates a modulation signal corresponding to the image information and applies the modulation signal to the light source driving unit 102. At this time, light modulated according to the image information is emitted from the laser source 101. After receiving the synchronization control signal, the deflector control unit 1004 generates a drive signal for driving the deflector 701 and applies the drive signal to the deflector 701. At this time, the deflector 701 performs laser beam scanning.

[0117] In the final step S6, the display control unit 1001 determines whether to end the process. For example, the determination is affirmative when the power to the image display device 10 is off, and negative when the power is on. When the determination in step S6 is affirmative, the process ends; when the determination is negative, the process returns to step S1.

[0118] (The effect of image display devices and image display methods)

[0119] The effects of the image display device 10 and the image display method using the image display device 10 will be described below.

[0120] The image display device 10 includes: a light source system 100 including at least one laser light source 101, the light source system 100 being configured to emit laser light modulated according to image information; a branching optical path selection system 200 including a first polarization beam splitter 202, the first polarization beam splitter 202 being configured to branch the optical path of the laser light emitted from the light source system 100 into a first branch optical path BOP1 and a second branch optical path BOP2; and an optical path combining system 600 configured to combine the first branch optical path BOP1 and the second branch optical path BOP2, wherein the branch optical path selection system 200 selects at least one branch optical path (e.g., a branch optical path) from the first branch optical path BOP1 and the second branch optical path BOP2 based on image information as the branch optical path along which the laser light travels from the first polarization beam splitter 202. The image display device 10 also includes a first optical processing system configured to apply optical processing to the laser light traveling along the first branch optical path BOP1 in the first branch optical path BOP1 and the second branch optical path BOP2.

[0121] In the image display device 10, the first optical processing can be selectively applied to the laser or not applied, depending on the image information; therefore, optical processing can be reliably applied only to the light modulated by the image information that needs to be optically processed.

[0122] As a result, by using the image display device 10, an image display device that can improve image reproducibility can be provided.

[0123] In the light source system 100, the excitation intensity of the laser light source 101 exceeds the laser threshold, and the first optical processing system includes a light attenuation section 501 configured to attenuate the laser light traveling along the first branch optical path BOP1. Therefore, both the high-brightness and low-brightness ranges of the image can be generated while maintaining stable light output from the laser light source 101. That is, the reproducibility of the low-brightness range of the image can be improved.

[0124] When the brightness of the image information is within a first brightness range less than or equal to a predetermined value, the branch optical path selection system 200 selects the first branch optical path BOP1 as the branch optical path along which the laser travels from the first polarization beam splitter 202. And when the brightness of the image information is within a second brightness range greater than a predetermined value, the branch optical path selection system 200 selects the second branch optical path BOP2 as the branch optical path along which the laser travels from the first polarization beam splitter 202. Therefore, optical attenuation processing can be reliably applied only to the light modulated by the image information requiring optical attenuation processing.

[0125] The second brightness range is wider than the first brightness range. This eliminates the need to apply optical processing to the high brightness range of light, which corresponds to more than half of the image information in the dynamic range.

[0126] The image display method using the image display device 10 includes: emitting a laser beam modulated according to image information; selecting at least one (e.g., one) branch optical path from a plurality of branch optical paths obtained through branch optical paths as the branch optical path along which the laser beam travels, based on the image information; when a first branch optical path BOP1 is selected from the plurality of branch optical paths as the branch optical path along which the laser beam travels, applying a first optical processing to the laser beam traveling along the first branch optical path BOP1; and synthesizing the first branch optical path BOP1 and the second branch optical path BOP2.

[0127] Using image display methods, optical processing can be selectively applied to the laser or not, based on image information; therefore, optical processing can be reliably applied only to light modulated by image information that requires optical processing.

[0128] As a result, image reproducibility can be improved by using image display methods.

[0129] <2. Image display device according to Example 2 of this technical embodiment>

[0130] (Configuration of image display devices)

[0131] An image display device according to an embodiment of the present technology will be described with reference to the accompanying drawings. Figure 6 This is a diagram illustrating the configuration of the image display device 20 according to Example 2 of an embodiment. Figure 7 This is a block diagram illustrating the function of the image display device 20 according to Example 2 of an embodiment.

[0132] In the image display device 20, such as Figure 6 As shown, instead of the optical attenuation section 501, an optical fiber 901 (detour section) is provided on the first branch optical path BOP1 as a first optical processing system. The optical fiber 901 causes the laser traveling along the first branch optical path BOP1 to detour.

[0133] In the image display device 20, as an example, a reflector 301 is arranged upstream of optical fiber 901 on the first branch optical path BOP1, a reflector 401 is arranged downstream of optical fiber 901, and a second polarization beam splitter 603 is arranged downstream of the first polarization beam splitter 202 on the second branch optical path BOP2. As an example, optical fiber 901 has a multi-ring structure and is arranged between reflector 301 and reflector 401, such that its input end faces reflector 301 and its output end faces reflector 401.

[0134] In the image display device 20, the first linearly polarized light converted from the laser emitted from the light source system 100 by the polarization controllable element 201 is reflected by the first polarization beam splitter 202 toward the reflector 301, and then reflected by the reflector 301 toward the input end of the optical fiber 901. The first linearly polarized light traveling along the optical fiber 901 is reflected by the reflector 401 toward the second polarization beam splitter 603. The first linearly polarized light incident on the second polarization beam splitter 603 is reflected by the second polarization beam splitter 603 toward the deflector 701 via the combined optical path of the first branch optical path BOP1 and the second branch optical path BOP2.

[0135] In the image display device 20, the second linearly polarized light converted from the laser emitted from the light source system 100 by the polarization controllable element 201 is transmitted through the first polarization beam splitter, through the second branch optical path BOP2, transmitted through the second polarization beam splitter 603, and enters the deflector 701 via the combined optical path of the first branch optical path BOP1 and the second branch optical path BOP2.

[0136] In the image display device 20, such as Figure 7 As shown, the control device 1200 does not include a brightness determination unit 1005, and the branch optical path selection unit 1006 selects one of the first branch optical path BOP1 and the second branch optical path BOP2 as the branch optical path along which the laser travels from the first polarization beam splitter 202 based on the drive signal output from the deflector control unit 1004 (a signal that can specify the pixel area to be scanned (displayed) in the image information on a frame-by-frame basis), and applies a voltage signal corresponding to the selection to the polarization controllable element 201.

[0137] After receiving a drive signal from the deflector control unit 1004, when the laser is modulated frame by frame according to the first pixel region (e.g., the center pixel region) of the image information (when the first pixel region is to be scanned (displayed)), the branch optical path selection unit 1006 selects the first branch optical path BOP1 as the branch optical path along which the laser travels from the first polarization beam splitter 202, and when the laser is modulated frame by frame according to the second pixel region (e.g., the peripheral pixel region) of the image information (when the second pixel region is to be scanned (displayed)), the branch optical path selection unit 1006 selects the second branch optical path BOP2 as the branch optical path along which the laser travels from the first polarization beam splitter 202.

[0138] The optical path length of the first branch path BOP1 through which the laser passes is sufficiently increased by optical fiber 901; therefore, the laser reaches the eyeball EB with a sufficient time difference relative to the laser passing through the second branch path BOP2. Due to this time difference, the resolution of the image displayed by the laser passing through the first branch path BOP1 is pseudo-enhanced, which can lead to an improvement in image quality (improved visibility).

[0139] As a time difference, it is preferable to generate a time difference corresponding to half a pixel. For example, when the frame rate is 60Hz and the resolution is 1980×1080, the laser source 101 emits light at approximately 128MHz, and the time difference corresponding to half a pixel is 1 / 256×10. -6 (see Figure 9 This corresponds to a frequency of 256MHz. The appearance of a time difference corresponding to a half-pixel means that a new emission occurs between the emission of laser source 101 emitting light at a emission frequency of 128MHz. From 300×10 6 The speed of light calculated at m / s is 1 / 256×10 -6 The time difference corresponds to an optical path difference of approximately 1.2m. Fiber 901 is used to generate this optical path difference.

[0140] (Operation of image display devices)

[0141] In the following text, reference will be made to Figure 8 Describe the operation of the image display device 20. Figure 8 The flowchart is based on the processing algorithm executed by the control device 1200. The operation of the image display device 20 represents the image display method using the image display device 20.

[0142] In the first step S11, the image information input unit 1002 sequentially receives the input of image information (image data) sent from the external device 2000, sends an input timing signal to the display control unit 1001 for each input, and sequentially sends the input image information to the modulation signal generation unit 1003.

[0143] In the next step S12, the branch optical path selection unit 1006 determines whether to display the first pixel region of image information frame by frame, i.e., whether to display the first pixel region or the second pixel region of image information frame by frame, based on the drive signal output from the deflector control unit 1004. When the determination is affirmative, the process proceeds to step S13, and when the determination is negative, the process proceeds to step S14.

[0144] In step S13, the branch optical path selection unit 1006 selects the first branch optical path BOP1 as the branch optical path along which the laser travels from the first polarization beam splitter 202. Specifically, the branch optical path selection unit 1006 applies a first voltage signal to the polarization controllable element 201 to convert the laser emitted from the light source system 100 into first linearly polarized light. After executing step S13, the process proceeds to step S15.

[0145] In step S14, the branch optical path selection unit 1006 selects the second branch optical path BOP2 as the branch optical path along which the laser travels from the first polarization beam splitter 202. Specifically, the branch optical path selection unit 1006 applies a second voltage signal to the polarization controllable element 201 to convert the laser emitted from the light source system 100 into second linearly polarized light. After executing step S14, the process proceeds to step S15.

[0146] In step S15, the display control unit 1001 drives the laser source 101 and the deflector 701 according to the image information. Specifically, the display control unit 1001 sends a synchronization control signal to the modulation signal generation unit 1003 and the deflector control unit 1004. After receiving the synchronization control signal, the modulation signal generation unit 1003 generates a modulation signal corresponding to the image information and applies the modulation signal to the light source driving unit 102. At this time, light modulated according to the image information is emitted from the laser source 101. After receiving the synchronization control signal, the deflector control unit 1004 generates a drive signal for driving the deflector 701 and applies the drive signal to the deflector 701. At this time, laser beam scanning is performed through the deflector 701.

[0147] In step S16, the display control unit 1001 determines whether to end the process. For example, the determination is affirmative when the power to the image display device 20 is off, and negative when the power is on. When the determination in step S16 is affirmative, the process ends; when the determination is negative, the process returns to step S11.

[0148] (The effect of the image display device)

[0149] The effects of the image display device 20 will be described below.

[0150] In the image display device 20, the first optical processing system includes an optical fiber 901 configured to circumvent a laser traveling along a first branch optical path BOP1. When the laser is modulated frame-by-frame according to a first pixel region (e.g., a central pixel region) of image information, the branch optical path selection system 200 selects the first branch optical path BOP1 as the branch optical path along which the laser travels from the first polarization beam splitter 202, and when the laser is modulated frame-by-frame according to a second pixel region (e.g., a peripheral pixel region) of image information, it selects the second branch optical path BOP2 as the branch optical path along which the laser travels from the first polarization beam splitter 202.

[0151] In this case, with a simple configuration, the resolution of the image corresponding to the first pixel region of image information frame by frame can be made to be substantially higher than the resolution of the image corresponding to the second pixel region, thereby improving the visibility of the image corresponding to the first pixel region.

[0152] Note that the branch path selection system 200 can alternately select the first branch path BOP1 as the branch path for the laser to travel from the first polarization beam splitter 202 and the second branch path BOP2 as the branch path for the laser to travel from the first polarization beam splitter 202 every N frames (N≥1; N is a natural number). As a result, the laser path switches every N frames; therefore, the resolution can be increased in an interleaved manner. In this case, the response frequency of the branch path selection unit 1006 is equal to N times the frame rate.

[0153] Furthermore, when the laser emitted from the light source system 100 is converted into 45° linearly polarized light or circularly polarized light by the polarization controllable element 201 and guided into the first polarization beam splitter 202, both the first branch optical path BOP1 and the second branch optical path BOP2 can be simultaneously selected as the optical path for laser travel, thereby enabling the resolution to be doubled in any frame.

[0154] <3. Image display device according to Example 3 of this technical embodiment>

[0155] (Configuration of image display devices)

[0156] An image display device according to an embodiment of the present technology will be described with reference to the accompanying drawings. Figure 10 This is a diagram illustrating the configuration of the image display device 30 according to Example 3 of an embodiment. Figure 11 This is a block diagram illustrating the function of the image display device 30 according to Example 3 of an embodiment.

[0157] like Figure 10 As shown, the image display device 30 has a configuration based on a combination of a portion of the image display device 10 according to Example 1 and a portion of the image display device 20 according to Example 2.

[0158] In the image display device 30, a portion of the image display device 20 is arranged upstream, and a portion of the image display device 10 is arranged downstream. In the image display device 30, the identifier "-2" is appended to the reference numerals representing components identical to those in the image display device 10, and the identifier "-1" is appended to the reference numerals representing components identical to those in the image display device 20.

[0159] The image display device 30 includes a light source system 100, a first polarization controllable element 201-1, a first polarization beam splitter 202-1, a reflector 301-1, an optical fiber 901, a reflector 401-1, and a second polarization beam splitter 603-1, all of which are disposed upstream.

[0160] In the image display device 30, the branch optical path selection system 200-1 selects at least one of the first branch optical path BOP1 or the second branch optical path BOP2 as the branch optical path along which the laser travels from the first polarization beam splitter 202-1.

[0161] The image display device 30 includes a second polarization controllable element 201-2, a first polarization beam splitter 202-2, a mirror 301-2, an optical attenuation section 501, a half-wave plate 601, a mirror 401-2, a half-wave plate 602, a second polarization beam splitter 603-2 (optical path combining section), a deflector 701, and an eyepiece 801, all disposed downstream of the second polarization beam splitter 603-1.

[0162] In the image display device 30, the branch optical path selection system 200-2 selects either the third branch optical path BOP3 or the fourth branch optical path BOP4 as the branch optical path along which the laser travels from the first polarization beam splitter 202-2. A mirror 301-2, an optical attenuator 501, and a half-wave plate 601 are arranged sequentially on the third branch optical path BOP3 from the first polarization beam splitter 202-2 toward the second polarization beam splitter 603-2. A mirror 401-2 and a half-wave plate 602 are arranged sequentially on the fourth branch optical path BOP4 from the first polarization beam splitter 202-2 toward the second polarization beam splitter 603-2.

[0163] In the image display device 30, the control device 1300 controls the light source system 100, the first and second polarization controllable elements 201-1 and 201-2, and the deflector 701.

[0164] like Figure 11 As shown, the control device 1300 includes a first branch optical path selection unit 1006-1 for controlling the first polarization controllable element 201-1 and a second branch optical path selection unit 1006-2 for controlling the second polarization controllable element 201-2.

[0165] (Operation of image display devices)

[0166] In the following text, reference will be made to Figure 12 Describe the operation of the image display device 30. Figure 12 The flowchart is based on a processing algorithm executed by the control device 1300. The operation of the image display device 30 also constitutes an image display method using the image display device 30.

[0167] In the first step S21, the image information input unit 1002 sequentially receives the image information (image data) sent from the external device 2000, sends an input timing signal to the display control unit 1001 for each input, and sequentially sends the input image information to the modulation signal generation unit 1003 and the brightness determination unit 1005.

[0168] In the next step S22, the first branch optical path selection unit 1006-1 determines whether to display the first pixel area of ​​image information in frames, i.e., whether to display the first pixel area or the second pixel area of ​​image information in frames, based on the drive signal output from the deflector control unit 1004. When the determination is affirmative, the process proceeds to step S23, and when the determination is negative, the process proceeds to step S24.

[0169] In step S23, the first branch optical path selection unit 1006-1 selects the first branch optical path BOP1 as the branch optical path along which the laser (e.g., linearly polarized light) travels from the first polarization beam splitter 202-1. Specifically, the first branch optical path selection unit 1006-1 applies a first voltage signal to the first polarization controllable element 201-1 to convert the laser emitted from the light source system 100 into first linearly polarized light. After executing step S23, the process proceeds to step S25.

[0170] In step S24, the first branch optical path selection unit 1006-1 selects the second branch optical path BOP2 as the branch optical path along which the laser travels from the first polarization beam splitter 202-1. Specifically, the first branch optical path selection unit 1006-1 applies a second voltage signal to the first polarization controllable element 201-1 to convert the laser emitted from the light source system 100 into second linearly polarized light. After executing step S24, the process proceeds to step S25.

[0171] In step S25, the brightness determination unit 1005 determines whether the brightness of the image information is within a first brightness range (low brightness range), that is, whether the brightness of the image information is within the first brightness range or a second brightness range (high brightness range). When the determination is affirmative, the process proceeds to step S26, and when the determination is negative, the process proceeds to step S27.

[0172] In step S26, the second branch optical path selection unit 1006-2 selects the third branch optical path BOP3 as the branch optical path along which the laser travels from the first polarization beam splitter 202-2. Specifically, the second branch optical path selection unit 1006-2 applies a first voltage signal to the second polarization controllable element 201-2 to convert the second linearly polarized light emitted from the second polarization beam splitter 603-1 into first linearly polarized light (to allow the first linearly polarized light to pass through as is). After executing step S26, the process proceeds to step S28.

[0173] In step S27, the second branch optical path selection unit 1006-2 selects the fourth branch optical path BOP4 as the branch optical path along which the laser travels from the first polarization beam splitter 202-2. Specifically, the second branch optical path selection unit 1006-2 applies a second voltage signal to the second polarization controllable element 201-2 to convert the first linearly polarized light emitted from the second polarization beam splitter 603-1 into second linearly polarized light (to allow the second linearly polarized light to pass through as is). After executing step S27, the process proceeds to step S28.

[0174] In step S28, the display control unit 1001 drives the laser source 101 and the deflector 701 according to the image information. Specifically, the display control unit 1001 sends a synchronization control signal to the modulation signal generation unit 1003 and the deflector control unit 1004. After receiving the synchronization control signal, the modulation signal generation unit 1003 generates a modulation signal corresponding to the image information and applies the modulation signal to the light source driving unit 102. At this time, light modulated according to the image information is emitted from the laser source 101. After receiving the synchronization control signal, the deflector control unit 1004 generates a drive signal for driving the deflector 701 and applies the drive signal to the deflector 701. At this time, laser beam scanning is performed through the deflector 701.

[0175] In the final step S29, the display control unit 1001 determines whether to end the process. For example, the determination is affirmative when the power to the image display device 30 is off, and negative when the power is on. When the determination in step S29 is affirmative, the process ends; when the determination is negative, the process returns to step S21.

[0176] (The effect of the image display device)

[0177] The effects of the image display device 30 will be described below.

[0178] Image display device 30 includes: a light source system 100, which includes at least one laser light source 101, the light source system 100 being configured to emit laser light modulated according to image information; a branching optical path selection system 200-1, which includes a first polarization beam splitter 202-1, the first polarization beam splitter 202-1 being configured to branch the optical path of the laser light emitted from the light source system 100 into first and second branch optical paths BOP1 and BOP2; and an optical path combining system 600-1, which includes a second polarization beam splitter 603-1, the second polarization beam splitter... Beam splitter 603-1 is configured to combine first and second branch optical paths BOP1 and BOP2, wherein branch optical path selection system 200-1 selects at least one of the first branch optical path BOP1 or the second branch optical path BOP2 as the branch optical path along which the laser travels from the first polarization beam splitter 202. The image display device 30 also includes an optical fiber 901 as a first optical processing system, which is configured to perform optical processing on the laser traveling along the first branch optical path BOP1 of the first and second branch optical paths BOP1 and BOP2.

[0179] The image display device 30 further includes: a branch optical path selection system 200-2, which includes a first polarization beam splitter 202-2, configured to branch the optical path obtained by combining the first and second branch optical paths BOP1 and BOP2 in the optical path combining system 600-1 into third and fourth branch optical paths BOP3 and BOP4; and an optical path combining system 600-2, which includes a second polarization beam splitter 603-2, configured to combine the third and fourth branch optical paths BOP3 and BOP4, wherein the branch optical path selection system 200-2 selects one of the third and fourth branch optical paths BOP3 and BOP4 as another branch optical path for the laser to travel along the first polarization beam splitter 202-2 based on image information. The image display device 30 also includes an optical attenuation unit 501 as a second optical processing system, configured to perform optical processing on the laser traveling along the third branch optical path BOP3 of the third and fourth branch optical paths BOP3 and BOP4.

[0180] By using the image display device 30, both the effect of the image display device 10 according to Example 1 and the effect of the image display device 20 according to Example 2 can be obtained.

[0181] It should be noted that in the image display device 30, a portion of the image display device 10 can be arranged upstream, and a portion of the image display device 20 can be arranged downstream.

[0182] In the image display device 30, the light source system 100 includes a single laser light source 101; however, the light source system 100 may include, for example, a laser light source configured to emit red laser, a laser light source configured to emit green laser, and a laser light source configured to emit blue laser, and may emit colored light obtained by synthesizing lasers emitted from these laser light sources.

[0183] <4. Image display device according to Example 4 of this technical embodiment>

[0184] (Configuration of image display devices)

[0185] An image display device according to an embodiment of the present technology, as described with reference to the accompanying drawings, will be used to illustrate this device. Figure 13 This is a diagram illustrating the configuration of an image display device 40 according to Example 4 of an embodiment. Figure 14 This is a block diagram illustrating the function of the image display device 40 according to Example 4 of an embodiment.

[0186] Incidentally, laser sources emitting red, green, and blue lasers typically have different threshold currents. Therefore, when the colored light obtained by synthesizing red, green, and blue lasers is attenuated, the laser of each color attenuates uniformly, resulting in increased color variation in the low brightness range depending on temperature conditions or grayscale levels. As described in detail below, the image display device 40 has a configuration capable of solving this problem and can obtain images with high resolution and high dynamic range.

[0187] like Figure 13 and Figure 14 As shown, the image display device 40 includes a portion of the image display device 10 according to Example 1, which is disposed upstream for each of the RGB colors, and a portion of the image display device 20 according to Example 2, which is disposed downstream.

[0188] The image display device 40 includes multiple (e.g., three) laser sources 101R, 101G, and 101B with different emission wavelengths, and for each laser source, a branching optical path selection system, an optical path combining system, and a first optical processing system (optical attenuation section 501) are provided. Laser source 101R emits a wavelength in the red band. Laser source 101G emits a wavelength in the green band. Laser source 101B emits a wavelength in the blue band. The optical attenuation section 501, individually provided for each laser source, can have different optical attenuations.

[0189] The light source system 100R, which includes laser light source 101R, the light source system 100G, which includes laser light source 101G, and the light source system 100B, which includes laser light source 101B, share a light source driving unit 102.

[0190] The modulation signal generation unit 1003 generates modulation signals for modulating the laser light source 101R, the laser light source 101G, and the laser light source 101B based on color image information output from the external device 2000 and received by the image information input unit 1002, and applies each modulation signal to the light source driving unit 102. The light source driving unit 102 generates a driving current to be applied to the corresponding laser light source based on each modulation signal.

[0191] In the image display device 40, the control device 1400 includes: a brightness determination unit 1005R, a branch optical path selection unit 1006R, and a polarization controllable element 201R corresponding to the laser light source 101R; a brightness determination unit 1005G, a branch optical path selection unit 1006G, and a polarization controllable element 201G corresponding to the laser light source 101G; and a brightness determination unit 1005B, a branch optical path selection unit 1006B, and a polarization controllable element 201B corresponding to the laser light source 101B.

[0192] The image display device 40 also includes a reflector 951, a reflector 952, a dichroic mirror 953, and a dichroic mirror 954. The dichroic mirror 953 reflects green light and transmits blue light to synthesize the light paths of green and blue light. The dichroic mirror 954 reflects red light and transmits green and blue light to synthesize the light paths of red, green, and blue light.

[0193] The laser (red light) emitted from the second polarization beam splitter 603 corresponding to the light source system 100R is reflected by the reflector 951 toward the dichroic mirror 954, and is also reflected by the dichroic mirror 954 toward the polarization controllable element 201.

[0194] The laser (green light) emitted from the second polarization beam splitter 603 corresponding to the light source system 100G is reflected by the reflector 952 toward the dichroic mirror 953, reflected by the dichroic mirror 953 toward the dichroic mirror 954, and transmitted through the dichroic mirror 954 toward the polarization controllable element 201.

[0195] The laser (blue light) emitted from the second polarization beam splitter 603 corresponding to the light source system 100B passes through the dichroic mirror 953 and is transmitted toward the dichroic mirror 954, and then passes through the dichroic mirror 954 and is transmitted toward the polarization controllable element 201.

[0196] Light of each color incident on polarization controllable element 201 passes through at least one branch optical path selected by branch optical path selection system 200 and enters deflector 701 via second polarization beam splitter 603. For each color of light incident on deflector 701, laser beam scanning is performed on the eyeball EB via eyepiece 801.

[0197] <5. Image display device according to Example 5 of this technical embodiment>

[0198] The image display device 50 of Example 5 according to an embodiment of the present technology will be described with reference to the accompanying drawings. Figure 15 This is a diagram illustrating the configuration of an image display device 50 according to Example 5 of an embodiment. Figure 16 This is a block diagram illustrating the functionality of the image display device 50 according to Example 5 of an embodiment.

[0199] like Figure 15 and Figure 16 As shown, the image display device 50 includes a digital mirroring device 203 (DMD) as an optical path branch.

[0200] The digital mirroring device 203 is an element comprising a plurality of micromirrors (pixels) arranged two-dimensionally (e.g., in a matrix pattern, interlaced pattern, etc.) on a substrate and rotatable relative to the substrate (capable of changing their orientation). The digital mirroring device 203 is arranged to allow laser light emitted from the light source system 100 to be incident obliquely onto the digital mirroring device 203 relative to the normal direction (hereinafter also simply referred to as the "normal direction") of the substrate surface. When in an on state, the digital mirroring device 203 sets each micromirror to an on orientation obtained by rotating the micromirror from a reference orientation (OFF orientation) parallel to the substrate surface, so that the micromirror reflects the obliquely incident laser light along the normal direction. The reflected laser light travels along the first branch optical path BOP1, is attenuated by the light attenuation section 501, reflected by the reflector 301, and enters the semi-reflective mirror 604, which serves as the optical path combining section. When in the off state, the digital mirroring device 203 holds each micromirror in the reference orientation (OFF orientation) so that the micromirrors reflect the obliquely incident laser in a direction tilted to the normal direction. The reflected laser travels along the second branch optical path BOP2 and enters the semi-reflective mirror 604.

[0201] The laser light passing through the semi-reflecting mirror 604 via the first branch optical path BOP1 and the laser light reflected by the semi-reflecting mirror 604 via the second branch optical path BOP2 travel along the common optical path (composite optical path), are deflected by the deflector 701, and enter the eyeball EB via the eyepiece 801.

[0202] Digital mirroring device 203 is controlled by control device 1100 (see...) Figure 16Specifically, when the first branch optical path BOP1 is selected based on the determination result of the brightness determination unit 1005, the branch optical path selection unit 1006 sets the mirror drive signal used to drive the micromirrors of the digital mirroring device 203 corresponding to each pixel of the image information to a high level to set the micromirrors to the on orientation. When the second branch optical path BOP2 is selected, the branch optical path selection unit 1006 sets the mirror drive signal used to drive the micromirrors of the digital mirroring device 203 corresponding to each pixel of the image information to a low level to set the micromirrors to the off orientation.

[0203] It should be noted that the optical system described herein is arranged such that laser light traveling along the first branch optical path BOP1 is transmitted through the half-mirror 604 and laser light traveling along the second branch optical path BOP2 is reflected by the half-mirror 604; alternatively, the optical system may be arranged such that laser light traveling along the first branch optical path BOP1 is reflected by the half-mirror 604 and laser light traveling along the second branch optical path BOP2 is transmitted through the half-mirror 604. Furthermore, a configuration in which the optical attenuation portion 501 is arranged on the second branch optical path BOP2 may be adopted.

[0204] <5.5. A variant of Example 5 of the embodiments of the present technology, an image display device>

[0205] A variation of an image display device according to an embodiment of the present technology, as described with reference to the accompanying drawings, is an example 5. Figure 17 This is a diagram illustrating the configuration of an image display device 55, a variant of Example 5 according to an embodiment.

[0206] In the image display device 55, such as Figure 17 As shown, the optical path combining system 600 includes a polarization beam splitter 605 as the optical path combining part and a half-wave plate 602 arranged on the second branch optical path BOP2.

[0207] In the image display device 55, the light source system 100 emits first linearly polarized light (laser) with a predetermined polarization direction. The first linearly polarized light traveling from the digital mirror device 203 to the first branch optical path BOP1 is attenuated by the light attenuation section 501, reflected by the mirror 301, transmitted through the polarization beam splitter 605, and enters the deflector 701. The first linearly polarized light traveling from the digital mirror device 203 to the second branch optical path BOP2 is converted into second linearly polarized light by the half-wave plate 602, with its polarization direction orthogonal to that of the first linearly polarized light. The second linearly polarized light is reflected by the polarization beam splitter 605 and enters the deflector 701.

[0208] The laser transmitted through the first branch optical path BOP1 and passed through the polarization beam splitter 605 and the laser reflected by the polarization beam splitter 605 through the second branch optical path BOP2 travel along the common optical path (combined optical path), are deflected by the deflector 701, and enter the eyeball EB through the eyepiece 801.

[0209] Although the configuration of the image display device 55 is slightly complex because the optical path combining system 600 includes a polarization beam splitter 605 and a half-wave plate 602, the image display device 55 can minimize light intensity loss.

[0210] <6. Image display device of Example 6 according to the embodiments of the present technology>

[0211] Example 6 of an image display device according to an embodiment of the present technology will be described with reference to the accompanying drawings. Figure 18 This is a diagram illustrating the configuration of an image display device 60 according to Example 6 of an embodiment. Figure 19 This is a block diagram illustrating the function of the image display device 60 according to Example 6 of an embodiment.

[0212] like Figure 18 and Figure 19 As shown, the image display device 60 includes a reflective liquid crystal grating 4000 (liquid crystal grating) as a branch portion of the optical path. The reflective liquid crystal grating 4000 is an element having a plurality of liquid crystals (pixels) arranged in a two-dimensional manner. When in the on state, the reflective liquid crystal grating 4000 diffracts and reflects incident light (laser), and when in the off state, the reflective liquid crystal grating 4000 transmits the incident light (laser) as is. The laser light diffracted and reflected by the reflective liquid crystal grating 4000 travels along the first branch optical path BOP1 and enters the dispersion-compensating reflective grating 4500 (diffraction element). The dispersion-compensating reflective grating 4500 includes a reflective grating having the same grating spacing as the reflective liquid crystal grating 4000. When laser light is diffracted and reflected by the reflective liquid crystal grating 4000, the dispersion-compensating reflective grating 4500 compensates for the angular deviation caused by wavelength dispersion and diffracts and reflects the incident light at the same diffraction angle as the laser light diffracted and reflected by the reflective liquid crystal grating 4000. The laser light diffracted and reflected by the dispersion-compensating reflective grating 4500 is attenuated by the light attenuation portion 501 and enters the half-mirror 604. The laser light transmitted through the reflective liquid crystal grating 4000 is reflected by the reflective mirror 401 and enters the half-mirror 604.

[0213] The laser passing through the first branch optical path BOP1 and the half-mirror 604 and the laser passing through the second branch optical path BOP2 and reflected by the half-mirror 604 travel along the common optical path (composite optical path), are deflected by the deflector 701, and enter the eyeball EB through the eyepiece 801.

[0214] The reflective liquid crystal grating 4000 is controlled by the control device 1100 (see...). Figure 19 Specifically, when the first branch optical path BOP1 is selected based on the determination result of the brightness determination unit 1005, the branch optical path selection unit 1006 sets the liquid crystal driving signal used to drive the liquid crystal of the reflective liquid crystal grating 4000 corresponding to each pixel of the image information to a high level, so as to set the liquid crystal to an on state (diffraction reflection state). When the second branch optical path BOP2 is selected, the branch optical path selection unit 1006 sets the liquid crystal driving signal used to drive the liquid crystal of the reflective liquid crystal grating 4000 corresponding to each pixel of the image data to a low level, so as to set the liquid crystal to an off state (transmission state).

[0215] It should be noted that the optical system described herein is arranged such that laser light traveling along the first branch optical path BOP1 is transmitted through the half-mirror 604 and laser light traveling along the second branch optical path BOP2 is reflected by the half-mirror 604; alternatively, the optical system may be arranged such that laser light traveling along the first branch optical path BOP1 is reflected by the half-mirror 604 and laser light traveling along the second branch optical path BOP2 is transmitted through the half-mirror 604. Furthermore, a configuration in which the optical attenuation portion 501 is arranged on the second branch optical path BOP2 may be adopted.

[0216] <6.5. A variant of Example 6 of the embodiments of the present technology, an image display device>

[0217] A variation of an image display device according to an embodiment of the present technology, as described with reference to the accompanying drawings, is an example 6. Figure 20 This is a diagram illustrating the configuration of an image display device 65, a variant of Example 6 according to an embodiment.

[0218] In the image display device 65, such as Figure 20 As shown, the optical path combining system 600 includes a polarization beam splitter 605 as the optical path combining part and a half-wave plate 602 arranged on the second branch optical path BOP2.

[0219] In the image display device 65, the light source system 100 emits first linearly polarized light (laser) with a predetermined polarization direction. The first linearly polarized light, diffracted and reflected by the reflective liquid crystal grating 4000 to the first branch optical path BOP1, is diffracted and reflected by the dispersion-compensating reflective grating 4500, attenuated by the light attenuation section 501, transmitted through the polarization beam splitter 605, and enters the deflector 701. The first linearly polarized light transmitted through the reflective liquid crystal grating 4000 to the second branch optical path BOP2 is reflected by the mirror 401 and converted into second linearly polarized light by the half-wave plate 602, whose polarization direction is orthogonal to that of the first linearly polarized light. The second linearly polarized light is reflected by the polarization beam splitter 605 and enters the deflector 701.

[0220] The laser beam transmitted through the first branch optical path BOP1 and the polarization beam splitter 605 and the laser beam reflected by the polarization beam splitter 605 through the second branch optical path BOP2 travel along the common optical path (combined optical path), are deflected by the deflector 701, and enter the eyeball EB through the eyepiece 801.

[0221] Although the configuration of the image display device 65 is slightly complex because the optical path combining system 600 includes a polarization beam splitter 605 and a half-wave plate 602, the image display device 65 can minimize light intensity loss.

[0222] <7. Image display device of Example 7 according to the embodiments of the present technology>

[0223] Example 7 of an image display device according to an embodiment of the present technology will be described with reference to the accompanying drawings. Figure 21 This is a diagram illustrating the configuration of an image display device 70 according to Example 7 of an embodiment. Figure 22 This is a block diagram illustrating the function of the image display device 70 according to Example 7 of an embodiment.

[0224] like Figure 21 and Figure 22 As shown, the image display device 70 includes a transmissive liquid crystal grating 5000 (liquid crystal grating) as a branch portion of the optical path. The transmissive liquid crystal grating 5000 is an element having a plurality of liquid crystals (pixels) arranged in a two-dimensional manner. When in the on state, the transmissive liquid crystal grating 5000 diffracts and transmits incident light (laser), and when in the off state, the transmissive liquid crystal grating 5000 transmits the incident light (laser) as is. The laser light diffracted and transmitted by the transmissive liquid crystal grating 5000 travels along the first branch optical path BOP1 and enters the dispersion-compensating transmissive grating 5500 (diffraction element). The dispersion-compensating transmissive grating 5500 includes a transmissive grating having the same grating spacing as the transmissive liquid crystal grating 5000. When laser light is diffracted and transmitted by the transmissive liquid crystal grating 5000, the dispersion-compensating transmissive grating 5500 compensates for the angular deviation caused by wavelength dispersion and diffracts and transmits the incident light at the same diffraction angle as the laser light diffracted and transmitted by the transmissive liquid crystal grating 5000. The laser light diffracted and transmitted by the dispersion-compensating transmissive grating 5500 is attenuated by the light attenuation portion 501 and enters the half-mirror 604. The laser light transmitted through the transmissive liquid crystal grating 5000 is reflected by the reflecting mirror 401 and enters the half-mirror 604.

[0225] The laser passing through the first branch optical path BOP1 and through the half-mirror 604, and the laser reflected by the half-mirror 604 through the second branch optical path BOP2, travel along the common optical path (composite optical path), are deflected by the deflector 701, and enter the eyeball EB through the eyepiece 801.

[0226] The transmissive liquid crystal grating 5000 is controlled by the control device 1100 (see...). Figure 22 Specifically, when the first branch optical path BOP1 is selected based on the determination result of the brightness determination unit 1005, the branch optical path selection unit 1006 sets the liquid crystal driving signal used to drive the liquid crystal of the transmissive liquid crystal grating 5000 corresponding to each pixel of the image information to a high level, so as to set the liquid crystal to the on state (diffraction transmission state). When the second branch optical path BOP2 is selected, the branch optical path selection unit 1006 sets the liquid crystal driving signal used to drive the liquid crystal of the transmissive liquid crystal grating 5000 corresponding to each pixel of the image information to a low level, so as to set the liquid crystal to the off state (transmission state).

[0227] Note that the optical system described herein is arranged such that laser light traveling along the first branch optical path BOP1 passes through the half-mirror 604, and laser light traveling along the second branch optical path BOP2 is reflected by the half-mirror 604; alternatively, the optical system may be arranged such that laser light traveling along the first branch optical path BOP1 is reflected by the half-mirror 604, and laser light traveling along the second branch optical path BOP2 passes through the half-mirror 604. Furthermore, a configuration in which an optical attenuation section 501 is arranged on the second branch optical path BOP2 may be employed.

[0228] <7.5. A variant of Example 7 of an embodiment of the present technology, an image display device>

[0229] A variation of an image display device according to an embodiment of the present technology, as described with reference to the accompanying drawings, is an example 7. Figure 23 This is a diagram illustrating the configuration of an image display device 75 according to a variant of Example 7.

[0230] In the image display device 75, such as Figure 23 As shown, the optical path combining system 600 includes a polarization beam splitter 605 as the optical path combining part and a half-wave plate 602 arranged on the second branch optical path BOP2.

[0231] In the image display device 75, the light source system 100 emits first linearly polarized light (laser) with a predetermined polarization direction. The first linearly polarized light, diffracted by the transmissive liquid crystal grating 5000 and passing through to the first branch optical path BOP1, is diffracted by the dispersion-compensated transmissive grating 5500 and passed through, attenuated by the light attenuation section 501, passes through the polarization beam splitter 605, and enters the deflector 701. The first linearly polarized light passing through the transmissive liquid crystal grating 5000 and reaching the second branch optical path BOP2 is converted into second linearly polarized light by the half-wave plate 602, with its polarization direction orthogonal to that of the first linearly polarized light. The second linearly polarized light is reflected by the mirror 401, reflected by the polarization beam splitter 605, and enters the deflector 701.

[0232] The laser light passing through the polarization beam splitter 605 via the first branch optical path BOP1 and the laser light reflected by the polarization beam splitter 605 via the second branch optical path BOP2 travel along the common optical path (combined optical path), are deflected by the deflector 701, and enter the eyeball EB via the eyepiece 801.

[0233] Although the configuration of the image display device 75 is slightly complex because the optical path combining system 600 includes a polarization beam splitter 605 and a half-wave plate 602, the image display device 75 can minimize light intensity loss.

[0234] <8. Variations of this technology>

[0235] The configuration of the image display device in each example of the above-described technology can be appropriately modified.

[0236] For example, as in accordance with Figure 24 As in the modified image display device 15 of Example 1 shown, the optical system can be arranged such that the optical path length of the first branch optical path BOP1 is longer than the optical path length of the second branch optical path BOP2, and an optical attenuation portion 501 can be arranged on the first branch optical path BOP1. Note that in Figure 15 In the layout of the optical system shown, an optical attenuation section 501 can be arranged on the second branch optical path BOP2.

[0237] Incidentally, in recent years, a technique called foveated rendering has emerged, in which only a portion of the retina corresponding to the fovea—the area where the optic nerve is concentrated (i.e., the portion on the screen the user is looking at)—is rendered at an increased resolution. By displaying the image at an increased resolution only within a visual field of approximately ±10 degrees centered on the fovea, a high-resolution image can be displayed only in the area of ​​interest. In this foveated rendering, the image can be displayed at an increased resolution by switching optical paths or using two optical paths only for the area where increased resolution is needed.

[0238] For example, as in accordance with Figure 25 As in the variant image display device of Example 2 shown, the branch optical path selection unit 1006 can select a branch optical path based on the drive signal of the deflector 701 and the detection result of the gaze detection device 3000 (eye-tracking device). Specifically, for example, the first pixel region of the image information can be set frame by frame as a region of interest including the user's gaze direction, and the second pixel region of the image information can be set as a peripheral region surrounding the region of interest. This allows for a significant increase in the resolution of the user's region of interest, thereby improving image visibility.

[0239] A gaze detection device 3000 can be installed on an eyeglass frame that serves as the aforementioned support structure. The gaze detection device 3000 detects the gaze (i.e., the direction of the user's eyeball EB) and outputs the detection result to a branch optical path selection unit 1006. The gaze detection device 3000 includes, for example, a light receiving / emitting unit and a signal processing unit that processes the output signal of the light receiving / emitting unit. The light receiving / emitting unit includes a light-emitting element that illuminates the eyeball EB with invisible light (e.g., infrared light) and a light-receiving element that receives light emitted from the light-emitting element and reflected by the eyeball EB. For example, a photodiode, a segmented photodiode with multiple light-receiving areas, an image sensor, an event-driven sensor (eye sensor), etc., can be used as the light-receiving element. The signal processing unit processes the output signal of the light-receiving element and calculates the direction of the gaze. Note that, in addition to or instead of a gaze detection device, a gaze guidance device can also be installed. The gaze guidance device can visually guide the gaze by displaying arrows, characters, etc., indicating the destination of the gaze guidance in a displayed image, or it can audibly guide the gaze using sound, etc.

[0240] For example, such as Figure 26 As shown in the variant image display device 45 according to Example 4, the configuration of the optical system from the polarization controllable element 201 to the second polarization beam splitter 603, which is omitted from the image display device 40 according to Example 4, can be adopted.

[0241] As a branch of the optical path, movable mirrors (devices that mechanically rotate mirrors), acousto-optic elements (AO elements), etc. can be used.

[0242] The bypass portion is not limited to optical fiber and can have any structure that extends the optical path length of the laser, such as a high refractive index medium.

[0243] Without causing inconsistencies, at least some configurations of the above embodiments and variations can be combined with each other.

[0244] In addition, this technology can also have the following configurations.

[0245] (1) An image display device, comprising: A light source system, the light source system including at least one laser light source, the light source system being configured to emit laser light modulated according to image information; A branched optical path selection system, the branched optical path selection system including an optical path branching section configured to branch the optical path of a laser emitted from the light source system into multiple branched optical paths; and An optical path combining system, configured to combine the multiple branch optical paths, wherein... The branch optical path selection system selects at least one branch optical path from the plurality of branch optical paths as the branch optical path along which the laser travels from the branch portion of the optical path. The image display device further includes a first optical processing system configured to perform optical processing on a laser traveling along a first branch optical path among the plurality of branch optical paths.

[0246] (2) The image display device according to (1), wherein the branch optical path selection system performs selection based on the image information.

[0247] (3) The image display device according to (1) or (2), wherein the excitation intensity of the laser source in the light source system exceeds a threshold, and the first optical processing system includes a light attenuation section configured to attenuate the laser traveling along the first branch optical path.

[0248] (4) The image display device according to any one of (1) to (3), wherein

[0249] When the brightness of the image information is within a first brightness range less than or equal to a predetermined value, the branch optical path selection system selects the first branch optical path as the branch optical path along which the laser travels from the branch portion of the optical path, and

[0250] When the brightness of the image information is within a second brightness range greater than the predetermined value, the branch optical path selection system selects a second branch optical path from the plurality of branch optical paths as the branch optical path along which the laser travels from the branch portion of the optical path.

[0251] (5) The image display device according to any one of (1) to (4), wherein the first optical processing system includes a bypass portion configured to bypass a laser traveling along the first branch optical path.

[0252] (6) The image display device according to (5), wherein

[0253] When the laser is modulated frame by frame according to the first pixel region of the image information, the branch optical path selection system selects the first branch optical path as the branch optical path along which the laser travels from the branch portion of the optical path, and

[0254] When the laser is modulated in units of one frame according to the second pixel region of the image information, the branch optical path selection system selects the second branch optical path from the multiple branch optical paths as the branch optical path along which the laser travels from the branch portion of the optical path.

[0255] (7) The image display device according to (5) or (6), wherein the branch optical path selection system alternately performs, at least on a frame-by-frame basis, selecting the first branch optical path as the branch optical path along which the laser travels from the branch portion of the optical path and selecting the second branch optical path from the plurality of branch optical paths as the branch optical path along which the laser travels from the branch portion of the optical path.

[0256] (8) The image display device according to any one of (1) to (7), further comprising: Another branch optical path selection system, the other branch optical path selection system including another optical path branching portion, the other optical path branching portion being configured to branch an optical path obtained by combining the plurality of branch optical paths in the optical path combining system into a plurality of other branch optical paths; and Another optical path combining system, configured to combine the plurality of other branch optical paths, wherein The other branch optical path selection system selects at least one branch optical path from the plurality of other branch optical paths based on the image information as another branch optical path along which the laser travels from the branch portion of the other optical path. The image display device further includes a second optical processing system configured to perform optical processing on a laser traveling along a third branch optical path among the plurality of other branch optical paths.

[0257] (9) The image display device according to (8), wherein

[0258] The excitation intensity of the laser source in the light source system exceeds a threshold, and

[0259] The second optical processing system includes an optical attenuation section configured to attenuate the laser light traveling along the third branch optical path.

[0260] (10) The image display device according to (8) or (9), wherein

[0261] When the brightness of the image information is within a first brightness range less than or equal to a predetermined value, the other branch optical path selection system selects the third branch optical path as the other branch optical path along which the laser travels from the branch portion of the other optical path, and

[0262] When the brightness of the image information is within a second brightness range greater than the predetermined value, the other branch optical path selection system selects a fourth branch optical path from the plurality of other branch optical paths as another branch optical path along which the laser travels from the branch portion of the other optical path.

[0263] (11) The image display device according to any one of (8) to (10), wherein the second optical processing system includes a bypass portion configured to bypass a laser traveling along the third branch optical path.

[0264] (12) The image display device according to (11), wherein

[0265] When the laser is modulated frame by frame according to the first pixel region of the image information, the other branch optical path selection system selects the third branch optical path as the other branch optical path along which the laser travels from the branch portion of the other optical path, and

[0266] When the laser is modulated in units of one frame according to the second pixel region of the image information, the other branch optical path selection system selects a fourth branch optical path from the plurality of other branch optical paths as another branch optical path along which the laser travels from the branch portion of the other optical path.

[0267] (13) The image display device according to (11) or (12), wherein the other branch optical path selection system alternately performs, at least on a frame-by-frame, selecting the third branch optical path as another branch optical path along which the laser travels from the branch portion of the other optical path and selecting the fourth branch optical path from the plurality of other branch optical paths as another branch optical path along which the laser travels from the branch portion of the other optical path.

[0268] (14) The image display device according to any one of (1) to (13), wherein

[0269] The branch optical path selection system includes a polarization-controllable element capable of changing the polarization state of the laser emitted from the light source system, and

[0270] The optical path branch and at least the optical path branch in the optical path combining system include a polarization beam splitter.

[0271] (15) The image display device according to any one of (8) to (14), wherein

[0272] The other branch optical path selection system includes a polarization-controllable element capable of changing the polarization state of the laser emitted from the optical path combining system, and

[0273] The other optical path branch and at least the other optical path branch in the other optical path combining system include a polarization beam splitter.

[0274] (16) The image display device according to any one of (1) to (15), wherein

[0275] The at least one laser source includes multiple laser sources with different emission wavelengths, and

[0276] For each of the laser light sources, the branch optical path selection system, the optical path combining system, and the first optical processing system are configured.

[0277] (17) The image display device according to any one of (1) to (16), wherein the optical path branch portion includes an element in which a plurality of pixels are arranged in two dimensions.

[0278] (18) The image display device according to any one of (8) to (17), wherein the other optical path branch portion includes an element in which a plurality of pixels are arranged in two dimensions.

[0279] (19) An image display method, comprising: Emit laser light modulated according to image information; Based on the image information, at least one branch optical path is selected from multiple branch optical paths obtained by branching the optical path as the branch optical path along which the laser travels; When a first branch optical path is selected from the plurality of branch optical paths as the branch optical path along which the laser travels, a first optical processing is performed on the laser traveling along the first branch optical path; and The multiple branch optical paths are synthesized.

[0280] (20) The image display method according to (19) further includes: Choose at least one branch optical path from among the other branch optical paths obtained by branching the synthesized optical path obtained by synthesizing multiple branch optical paths as another branch optical path along which the laser travels; When a third branch optical path is selected from multiple other branch optical paths as another branch optical path along which the laser travels, a second optical processing is performed on the laser traveling along the third branch optical path; and Multiple other branch optical paths are synthesized.

[0281] (21) The image display method according to (19) or (20), wherein the first optical processing includes light attenuation processing or light deflection processing.

[0282] (22) The image display method according to (20) or (21), wherein the second optical processing includes light attenuation processing or light detour processing.

[0283] (23) The image display device according to any one of (4)-(22), wherein the second brightness range is wider than the first brightness range.

[0284] (24) The image display device according to any one of (17)-(23), wherein the element comprises a liquid crystal grating.

[0285] (25) The image display device according to any one of (17)-(24), wherein the element includes a digital mirroring device.

[0286] (26) The image display device according to any one of (17)-(25), wherein the branch optical path selection system includes diffraction elements arranged upstream and / or downstream of the element.

[0287] (27) The image display device according to any one of (14)-(26), wherein the polarization controllable element comprises an electro-optic element.

[0288] (28) The image display device according to any one of (14)-(27), wherein the polarization controllable element includes a delay unit.

[0289] Liquid crystal display (LCD) element.

[0290] (29) The image display device according to any one of (1)-(28), wherein the optical path combining system further includes a first delayer arranged on a first branch optical path of a plurality of branch optical paths and a second delayer arranged on a second branch optical path of a plurality of branch optical paths.

[0291] (30) The image display device according to any one of (1)-(29), wherein the light attenuation portion includes a neutral density (ND) filter.

[0292] (31) The image display device according to any one of (1)-(30), wherein the light attenuation portion comprises a diffraction grating.

[0293] List of reference numerals

[0294] 10, 20, 30, 40 image display devices

[0295] 100 Light Source System

[0296] 101, 101R, 101G, 101B laser sources

[0297] 200-branch optical path selection system

[0298] 201 Polarization Controllable Component

[0299] 201-1 First Polarization Controllable Element

[0300] 201-2 Second polarization controllable element

[0301] 202, 202-1, 202-2 First polarization beam splitter (optical path branch section, polarization beam splitter)

[0302] 203 Digital Mirroring Equipment (Components)

[0303] 501 Optical Attenuation Section

[0304] 600, 600-1, 600-2 optical path combining systems

[0305] 603, 603-1, 603-2 Second Polarization Beam Splitter (Polarization Beam Splitter)

[0306] 901 fiber optic cable (rerouting section)

[0307] 4000 reflective liquid crystal grating (element)

[0308] 5000 Transmissive Liquid Crystal Grating (Element)

[0309] BOP1 First Branch Optical Path (Branch Optical Path)

[0310] BOP2 Second Branch Optical Path (Branch Optical Path)

[0311] BOP3 third branch optical path (another branch optical path)

[0312] BOP4 fourth branch optical path (another branch optical path)

Claims

1. An image display device, comprising: A light source system, including at least one laser light source, the light source system being configured to emit laser light modulated according to image information; A branched optical path selection system includes an optical path branching section configured to branch the optical path of a laser emitted from a light source system into multiple branched optical paths; and The optical path combining system is configured to combine multiple branch optical paths, among which The branch optical path selection system selects at least one branch optical path from multiple branch optical paths as the branch optical path for the laser to travel from the branch portion of the optical path. The image display device further includes a first optical processing system configured to perform optical processing on a laser traveling along a first branch optical path of multiple branch optical paths.

2. The image display device according to claim 1, wherein the branch optical path selection system performs selection based on image information.

3. The image display device according to claim 1, wherein... The excitation intensity of the laser source in the light source system exceeds the laser threshold, and The first optical processing system includes an optical attenuation section configured to attenuate laser light traveling along a first branch optical path.

4. The image display device according to claim 3, wherein When the brightness of the image information is within a first brightness range less than or equal to a predetermined value, the branch optical path selection system selects the first branch optical path as the branch optical path from which the laser travels from the branch portion of the optical path, and When the brightness of the image information is within a second brightness range greater than a predetermined value, the branch optical path selection system selects the second branch optical path from multiple branch optical paths as the branch optical path for the laser to travel from the branch part of the optical path.

5. The image display device of claim 1, wherein the first optical processing system includes a bypass portion configured to bypass a laser traveling along a first branch optical path.

6. The image display device according to claim 5, wherein When the laser is modulated frame by frame according to the first pixel region of the image information, the branch optical path selection system selects the first branch optical path as the branch optical path from which the laser travels from the branch part of the optical path, and When the laser is modulated in units of one frame according to the second pixel region of the image information, the branch optical path selection system selects the second branch optical path from multiple branch optical paths as the branch optical path for the laser to travel from the branch part of the optical path.

7. The image display device according to claim 5, wherein the branch optical path selection system alternately performs the following operations at least on a frame-by-frame basis: selecting a first branch optical path as the branch optical path from which the laser travels from the branch portion of the optical path, and selecting a second branch optical path from multiple branch optical paths as the branch optical path from which the laser travels from the branch portion of the optical path.

8. The image display device according to claim 1, further comprising: Another branch optical path selection system includes another optical path branching section, which is configured to branch the optical path obtained by combining multiple branch optical paths in the optical path combining system into multiple other branch optical paths; as well as Another optical path combining system is configured to combine multiple other branch optical paths, among which Another branch optical path selection system selects at least one branch optical path from multiple other branch optical paths based on image information as another branch optical path for the laser to travel from the branch portion of another optical path. The image display device further includes a second optical processing system configured to perform optical processing on a laser traveling along a third branch optical path that is part of a plurality of other branch optical paths.

9. The image display device according to claim 8, wherein The excitation intensity of the laser source in the light source system exceeds the laser threshold, and The second optical processing system includes an optical attenuation section configured to attenuate the laser light traveling along the third branch optical path.

10. The image display device according to claim 9, wherein When the brightness of the image information is within a first brightness range less than or equal to a predetermined value, the other branch optical path selection system selects the third branch optical path as the other branch optical path for the laser to travel from the branch portion of the other optical path, and When the brightness of the image information is within a second brightness range greater than a predetermined value, the other branch optical path selection system selects a fourth branch optical path from multiple other branch optical paths as another branch optical path for the laser to travel from the branch of another optical path.

11. The image display device of claim 8, wherein the second optical processing system includes a bypass portion configured to bypass a laser traveling along a third branch optical path.

12. The image display device according to claim 11, wherein When the laser is modulated frame by frame according to the first pixel region of the image information, the other branch optical path selection system selects the third branch optical path as the other branch optical path for the laser to travel from the branch portion of the other optical path, and When the laser is modulated in units of one frame according to the second pixel region of the image information, the other branch optical path selection system selects the fourth branch optical path from multiple other branch optical paths as another branch optical path for the laser to travel from the branch part of the other optical path.

13. The image display device according to claim 11, wherein the other branch optical path selection system alternately performs, at least on a frame-by-frame basis, selecting a third branch optical path as another branch optical path for the laser to travel from the branch portion of another optical path and selecting a fourth branch optical path from a plurality of other branch optical paths as another branch optical path for the laser to travel from the branch portion of another optical path.

14. The image display device according to claim 1, wherein, The branch optical path selection system includes a polarization-controllable element capable of changing the polarization state of the laser emitted from the light source system, and At least one optical path branch in the optical path combining system includes a polarization beam splitter.

15. The image display device according to claim 8, wherein, Another branch of the optical path selection system includes a polarization-controllable element capable of changing the polarization state of the laser emitted from the optical path combining system, and The other optical path branch and at least one other optical path branch in the other optical path combining system include a polarization beam splitter.

16. The image display device according to claim 1, wherein, At least one laser source comprises multiple laser sources with different emission wavelengths, and For each laser source, a branch optical path selection system, an optical path combining system, and a first optical processing system are set up.

17. The image display device according to claim 1, wherein, The optical path branch section includes elements in which multiple pixels are arranged in two dimensions.

18. The image display device according to claim 8, wherein, Another optical path branch includes elements in which multiple pixels are arranged in two dimensions.

19. An image display method, comprising: Emit laser light modulated according to image information; Based on image information, at least one branch optical path is selected from multiple branch optical paths obtained by branching the optical path as the branch optical path along which the laser travels; When a first branch optical path is selected from multiple branch optical paths as the branch optical path along which the laser travels, a first optical processing is performed on the laser traveling along the first branch optical path; and Multiple branch optical paths are synthesized.

20. The image display method according to claim 19, further comprising: Choose at least one branch optical path from among the other branch optical paths obtained by branching the synthesized optical path obtained by synthesizing multiple branch optical paths as another branch optical path along which the laser travels; When a third branch optical path is selected from multiple other branch optical paths as another branch optical path along which the laser travels, a second optical processing is performed on the laser traveling along the third branch optical path; and Multiple other branch optical paths are synthesized.

Images