Image display device

Abstract

An image display device according to the present technology includes: a light emitting unit that emits light; the phase modulator is used for carrying out spatial light phase modulation on incident light from the light emitting unit; and a control unit that causes the phase modulator to perform spatial light phase modulation for generating a first reconstructed image in the first reconstructed image region and a second reconstructed image in the second reconstructed image region, respectively, as reconstructed images generated by spatial light phase modulation of the incident light, the second reconstructed image area and the first reconstructed image area are located at different positions in the image plane direction; a projection lens that projects a first reconstructed image; and a light shielding unit performing light shielding on the second reconstructed image such that the second reconstructed image is not projected by the projection lens.

Description

Technical Field

[0001] The present technology relates to an image display device, and particularly to an image display technology in which a reproduced image having a desired light amount distribution is generated by applying spatial light phase modulation to incident light from a light emitting unit, and the reproduced image is projected by a projection lens. Background Art

[0002] For example, as disclosed in Patent Document 1 below, there is known a technique for generating an image (reproduced image) having a desired light amount distribution on a predetermined reproduction surface by spatial light phase modulation.

[0003] As a phase modulator that performs spatial light phase modulation, for example, a liquid crystal panel or the like is used. When the driving state of a pixel (for example, the alignment state of liquid crystal molecules) changes for a pixel constituting the phase modulator, the phase modulation amount (phase delay amount) of the incident light in the pixel changes. At this time, as the driving state of the pixel changes, the diffraction angle of the light incident on the pixel changes. Therefore, in the phase modulator, the emission angle of the emitted light (that is, the bending amount of the light) can be set for each pixel by setting the phase modulation amount for each pixel. By setting this bending light amount for each pixel, the light can be made dense in a specific area on the reproduction surface and sparse in another area, and a desired light amount distribution can be formed on the reproduction surface. That is, a reproduced image with a desired light amount distribution can be generated.

[0004] Here, examples of spatial light modulation for image reproduction include spatial light amplitude modulation, in which an amplitude modulator such as a digital micromirror device (DMD) configured to change the transmittance and reflectance of incident light for each pixel is used to generate a reproduced image with a desired light amount distribution.

[0005] In the case of performing image reproduction by spatial light phase modulation as described above relative to image reproduction by such spatial light amplitude modulation, it is not necessary to absorb or reflect a portion of the incident light when generating a reproduced image by a desired light quantity distribution, thereby having the advantage of improving the utilization efficiency of the incident light.

[0006] Note that, regarding the related conventional technology, the following Patent Document 2 may be mentioned in addition to the above-mentioned Patent Document 1. Patent Document 2 describes a technology for generating an image on a predetermined reproduction surface by spatially light modulating light from a light source using a holographic recording medium.

[0007] Reference List

[0008] Patent Literature

[0009] Patent Document 1: Publication No. 2020-503538

[0010] Patent Document 2: Publication No. 2012-58481 Summary of the invention

[0011] Problems to be solved by the present invention

[0012] As described above, image reproduction by spatial light phase modulation has the advantage of high light utilization efficiency, but as a contradiction, there is a disadvantage that the total light amount of the reproduced image cannot be adjusted only by the phase modulator. Therefore, in the case of an image display device that assumes that the reproduced image generated by the phase modulator is displayed as a projected image, the total light amount of the target image (image to be displayed) cannot be appropriately reproduced relative to the projected image, which leads to a decrease in the reproducibility of the target image.

[0013] Furthermore, in the case of performing image reproduction by spatial light phase modulation, in the case where the amount of bending of light exceeding the diffraction limit of the phase modulator is required, image reproduction cannot be properly performed. Specifically, in the case where even a part of the phase modulator has an area where light cannot be bent at the target position on the reproduction surface, light from the area is superimposed on the reproduced image as a noise component. That is, a component of aliasing noise (aliasing) not included in the target image is superimposed on the reproduced image, which causes the image quality of the displayed image to deteriorate. This can be considered that the reproducibility of the target image is deteriorated because a component not included in the target image is superimposed on the displayed image.

[0014] The present technology has been proposed in view of the above circumstances, and an object thereof is to improve the reproducibility of a display image with respect to a target image in an image display device that projects a reproduced image generated by spatial light phase modulation to display an image.

[0015] Solution to the problem

[0016] According to the present technology, an image display device includes: a light-emitting unit that emits light; a phase modulator that performs spatial light phase modulation on incident light from the light-emitting unit; a control unit that causes the phase modulator to perform spatial light phase modulation as a reproduced image generated for the incident light by spatial light phase modulation, the spatial light phase modulation being used to generate a first reproduced image in a first reproduced image area and a second reproduced image in a second reproduced image area that is different in position from the first reproduced image area in an image plane direction; a projection lens that projects the first reproduced image; and a shading unit that shields the second reproduced image so that the second reproduced image is not projected by the projection lens.

[0017] Therefore, when the first reproduced image is displayed as a projected image, unnecessary light can be discarded to the second reproduced image side. For example, when the actual total light amount of the first reproduced image exceeds the target total light amount, the total light amount of the image can be appropriately reproduced by discarding the light exceeding the target total light amount to the second reproduced image side, or aliasing can be prevented from occurring in the first reproduced image by discarding the light that requires a bending amount exceeding the diffraction limit to the second reproduced image side. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a diagram showing a configuration example of an image display device as a first embodiment.

[0019] Figure 2 This is a diagram for explaining the reproducibility of the total light amount of the phase modulator.

[0020] Figure 3 This is a diagram illustrating the diffraction limit of a phase modulator.

[0021] Figure 4 This is an explanatory diagram of an overview of a phase modulation method as an embodiment.

[0022] Figure 5 is a diagram for explaining an internal configuration example of a control unit included in the image display device as the first embodiment.

[0023] Figure 6 Detailed description of the invention is a flowchart showing an example of a process for implementing a phase modulation method as an embodiment.

[0024] Figure 7 Detailed description is a flowchart showing an example of a process of specifying a non-reproducible area in the embodiment.

[0025] Figure 8 Yes Description Figure 7 Prerequisite diagram.

[0026] Fig. 9 : is a diagram showing an example of area division in the process of specifying a non-reproducible area as an embodiment.

[0027] Fig.10 FIG. 1 is a diagram showing an example of area movement in the process of specifying a non-reproducible area as an embodiment.

[0028] Fig.11 This is an explanatory diagram of a method of specifying a non-reproducible area based on an allowable beam movement distance.

[0029] Fig.12 This is an explanatory diagram of a configuration in which a partial area in the first reproduced image and the second reproduced image does not satisfy the maximum diffraction angle restriction of the phase modulator.

[0030] Fig.13 This is an explanatory diagram of a case where the target total light amount of the first reproduced image cannot be reproduced.

[0031] Fig.14 is a diagram for explaining an internal configuration example of a control unit included in the image display device as the second embodiment.

[0032] Fig.15 is a flowchart showing an example of processing executed by a light amount control unit included in the image display device as the second embodiment.

[0033] Fig.16 is a diagram showing a configuration example of an image display device as a modification example of the second embodiment.

[0034] Fig.17 1 is an explanatory diagram of a configuration in which the entire area of ​​the first reproduced image satisfies the maximum diffraction angle restriction of the phase modulator, while a partial area of ​​the second reproduced image does not satisfy the maximum diffraction angle restriction of the phase modulator.

[0035] Fig.18 is adopting Fig.17 An explanatory diagram of a case where the target total light amount of the first reproduced image cannot be reproduced in the case of the configuration.

[0036] Fig.19 is an explanatory diagram of a configuration in which a partial area of ​​a first reproduced image does not satisfy the maximum diffraction angle restriction of a phase modulator and the entire area of ​​a second reproduced image satisfies the maximum diffraction angle restriction of the phase modulator.

[0037] Fig. 20 Is using Fig.19 This is an explanatory diagram of a case where the target total light amount of the first reproduced image cannot be reproduced in the case of the structure of FIG.

[0038] Fig.21 It is an explanatory diagram of a configuration in which the entire area satisfies the maximum diffraction angle restriction of the phase modulator in both the first reproduced image and the second reproduced image.

[0039] Fig. 22 is adopting Fig.21 An explanatory diagram of a case where the target total light amount of the first reproduced image cannot be reproduced in the case of the configuration.

[0040] Fig.23 1 is a diagram showing an image of a process for making a frame that cannot reproduce a target total light amount less noticeable by pre-fetching frames.

[0041] Fig.24 This is an explanatory diagram of a configuration in which the entire area of ​​the reproduced image satisfies the upper limit diffraction angle limit and is smaller than the maximum diffraction angle of the phase modulator.

[0042] Fig.25 is a diagram showing a configuration example of an image display device as a third embodiment.

[0043] Fig.26 It is an explanatory diagram showing another example of the irradiation direction of the zero-order light in the third embodiment.

[0044] Fig. 27 is a diagram showing a configuration example of an image display device as a fourth embodiment.

[0045] Fig.28 It is an explanatory diagram of an example of region division of the phase modulator in the fourth embodiment.

[0046] Fig.29 It is a diagram for explaining an internal configuration example of a control unit included in an image display device as a fourth embodiment.

[0047] Fig.30 : is a diagram showing an example of setting of the second reproduced image area for each wavelength band.

[0048] Fig.31 This is an explanatory diagram of an embodiment in which a plurality of second reproduced image areas are provided at different positions in the image plane direction.

[0049] Fig.32 This is an explanatory diagram in the case where only one second reproduced image area is provided.

[0050] Fig.33 It is an explanatory diagram of a modified example of the light shielding unit. DETAILED DESCRIPTION

[0051] Hereinafter, embodiments according to the present technology will be described in the following order with reference to the drawings.

[0052] <1. First Embodiment>

[0053] (1-1. Overview of equipment configuration)

[0054] (1-2. Overview of Phase Modulation Method as Embodiment)

[0055] (1-3. Specific solutions to Problems I and II)

[0056] (1-4. Processing procedures)

[0057] <2. Second Embodiment>

[0058] <3. Third Embodiment>

[0059] <4. Fourth Embodiment>

[0060] <5. Modifications>

[0061] <6. Overview of Implementation Methods>

[0062] <7. This technology>

[0063] <1. First Embodiment>

[0064] (1-1. Overview of equipment configuration)

[0065] Figure 1 : is a diagram showing a configuration example of an image display device 1 as an embodiment of the image display device according to the present technology.

[0066] As shown in the figure, the image display device 1 includes: a light-emitting unit 2 that emits light; a collimating lens 3 that collects the light emitted from the light-emitting unit 2 and emits parallel light; a phase modulator 4 that performs spatial light phase modulation on the incident light from the collimating lens 3 (i.e., the incident light from the light-emitting unit 2 via the collimating lens 3); a projection lens 5 that projects a reproduced image generated by the spatial light phase modulation of the phase modulator 4 onto a predetermined projection surface such as a surface of a screen Sc; a control unit 6 that performs light emission control of the light-emitting unit 2 and drive control of the phase modulator 4, and a shading unit 7.

[0067] In the image display device 1, the light emitting unit 2 includes one or more light emitting elements and emits light. As the light emitting element in the light emitting unit 2, for example, it is conceivable to use a semiconductor laser, a light emitting diode (LED), or the like.

[0068] In addition, in the image display device 1, for example, a reflective liquid crystal panel is used as the phase modulator 4. The phase modulator 4 performs spatial light phase modulation on the incident light from the light emitting unit 2 to reproduce a desired image (light quantity distribution) on a predetermined reproduction surface Sp, and projects the reproduced image on the projection surface through the projection lens 5 to display the image on the projection surface. Specifically, the control unit 6 calculates a phase modulation pattern for generating a reproduced image Im of the input image based on the input image, that is, an image obtained by reproducing the light quantity distribution of the input image. Here, the phase modulation pattern refers to the phase modulation amount of each pixel of the phase modulator 4. When the phase modulator 4 is driven according to the phase modulation pattern, a reproduced image Im of the input image is obtained on the reproduction surface Sp, and the reproduced image Im is projected on the projection surface through the projection lens 5, thereby displaying the reproduced image of the input image on the projection surface.

[0069] Here, for the calculation of the phase modulation pattern that generates an image with a desired light amount distribution at a desired position as a reproduced image Im, various known methods can be used, for example, a calculation method of a computer-generated hologram (CGH). Specifically, examples of the calculation method of CGH include a calculation method using the Gerchberg-Saxton algorithm disclosed in the above-mentioned patent document 1, a Wirtinger holographic algorithm, a stochastic gradient descent (SGD) algorithm, a calculation method using a learning model through deep learning, and the like. Here, the calculation method of CGH is not limited to a method using the diffraction principle, and a method using the refraction of light, such as a free form method, can also be used.

[0070] (1-2. Overview of Phase Modulation Method as Embodiment)

[0071] Here, as described above, image reproduction by spatial phase modulation has the advantage of high light utilization efficiency, but as a contradiction, there is the following disadvantage: the total light amount of the reproduced image cannot be adjusted by the phase modulator 4 alone. That is, the phase modulator 4 alone cannot reproduce the total light amount of the input image.

[0072] Figure 2 This is a diagram to illustrate this point.

[0073] For example, suppose there are two images with white areas of different sizes, as shown in the image with one white area on a black background. The image with the larger white area ( Figure 2 A) is defined as the first image, the image with a smaller white area ( Figure 2 B) is defined as the second image. At this time, each pixel in the white area has the same brightness value of the maximum value (for example, 255) (that is, the brightness of the white area is the same).

[0074] In the first and second images, because the brightness of the white area is the same, the total light amount of the first and second images is "first image > second image". In this way, the total light amount of the light amount distribution to be reproduced as the reproduced image (that is, the target total light amount of the reproduced image) can be changed according to the content of the input image.

[0075] Meanwhile, in the case where the phase modulator 4 performs spatial light phase modulation to generate a reproduced image, it can be considered that the total light amount is maintained between the incident light and the reproduced image (without considering light attenuation caused by the reflectivity, transmittance, diffraction efficiency, etc. of the phase modulator 4). Therefore, it cannot be guaranteed that the total light amount of the reproduced image generated by the spatial light phase modulation matches the above-mentioned target total light amount, and therefore it cannot be guaranteed that the phase modulator 4 alone can reproduce the total light amount of the input image.

[0076] If the total light amount of the reproduced image fails to match the target total light amount, the total light amount of the target image (image to be displayed) cannot be appropriately reproduced relative to the projection image (display image), resulting in reduced reproducibility of the target image.

[0077] Furthermore, when performing image reproduction by spatial light phase modulation, if the amount of light bending exceeding the diffraction limit of the phase modulator 4 is required, image reproduction cannot be performed appropriately.

[0078] First, refer to Figure 3 The diffraction limit of the phase modulator 4 is described.

[0079] As shown in the figure, when the pixel pitch of the phase modulator 4 is p, the wavelength of light incident on the phase modulator 4 is λ, and the diffraction limit is θ, the diffraction limit θ is represented by “2p·sinθ=λ”.

[0080] In the case where a reproduced image Im having the same size as the phase modulation area of ​​the phase modulator 4 is generated on a reproduction surface Sp separated from the phase modulator 4 by a focal length f along the optical axis direction, the maximum bending angle of the light required is the case where the light is bent in a diagonal direction such as from the upper left pixel of the phase modulator 4 to the lower right position of the reproduced image Im.

[0081] Here, in the case of p = 4.25 μm and λ = 450 nm, the diffraction limit θ is 3.5 degrees. Then, assuming the case of p = 4.25 μm and λ = 450 nm, and assuming that the number of horizontal effective pixels of the phase modulator = 1920 and the number of vertical effective pixels = 1080, the horizontal width of the reproduced image Im = 8.16 mm and the vertical width = 4.59 mm, and the diagonal length of the reproduced image Im is 9.36 mm.

[0082] At this time, if the focal length f = 75mm, the maximum bending angle of the light in the spatial light phase modulation is 7.1 degrees. In the case of p = 4.25μm and λ = 450nm, this exceeds the diffraction limit θ = 3.5 degrees. In this case, the light cannot be completely bent in at least a partial area of ​​the phase modulator 4, and the light from the partial area is superimposed on the reproduced image Im as a noise component. That is, a component of aliasing noise (aliasing) not included in the target image is superimposed on the reproduced image Im, which causes the image quality of the displayed image to deteriorate. This can be said to reduce the reproducibility of the target image because components not included in the target image are superimposed on the displayed image.

[0083] At this time, if the focal length f is increased, that is, the reproduction surface Sp is set farther, the maximum bending angle of the light can be reduced, and thus the occurrence of aliasing can be prevented. However, when the focal length f is increased, the image quality of the reproduced image Im deteriorates, and the size of the optical system increases, which may lead to an increase in the size of the device.

[0084] Therefore, in this embodiment, in order to solve the above two problems, that is, the problem that the total light amount of the target image cannot be properly reproduced (hereinafter referred to as "problem I") and the problem that aliasing occurs and the image quality deteriorates when the maximum bending angle of the light of the spatial light phase modulated exceeds the diffraction limit θ of the phase modulator 4 (hereinafter referred to as "problem II"), as shown in FIG. Figure 4 As shown, the following method is adopted: spatial light phase modulation is performed by the phase modulator 4, the second reproduced image Im2 is generated at a position in the image plane direction different from that of the first reproduced image Im1, and its light is discarded to the second reproduced image Im2 side.

[0085] Here, the image plane direction refers to a direction parallel to the reproduction plane of the first reproduced image Im1.

[0086] Specifically, in the present embodiment, as a reproduced image Im generated by spatial light phase modulation relative to incident light, the phase modulator 4 performs spatial light phase modulation for generating a first reproduced image Im1 in a first reproduced image area on the reproduction surface Sp and generating a second reproduced image Im2 in a second reproduced image area having a position different from that of the first reproduced image area in the image plane direction.

[0087] In this embodiment, the region for generating the second reproduced image Im2 is configured. Figure 1 The light shielding unit 7 shown. The light shielding unit 7 shields the second reproduced image Im2 so that the second reproduced image Im2 is not projected through the projection lens 5. Specifically, the light shielding unit 7 of this example is configured as a light absorbing portion that absorbs light constituting the second reproduced image Im2 and shields the second reproduced image Im2 so that the second reproduced image Im2 is not projected by the projection lens 5. In this case, the light shielding unit 7 is configured as, for example, a member to which a low-reflection coating such as black is applied to prevent reflection, a member composed of a low-reflection material, a member having a low-reflection structure, or the like.

[0088] In addition, the shading surface such as the light absorption surface in the shading unit 7 is not necessarily consistent with the image plane of the second reproduced image Im2. As long as the second reproduced image Im2 can be blocked by the projection lens 5 so that the second reproduced image Im2 is not projected (that is, it does not necessarily have to be consistent with the focused image plane), it can also be located in front of or behind the image plane of the second reproduced image Im2.

[0089] Since the light shielding unit 7 shields the second reproduced image Im2 , at least a part of the light incident on the phase modulator 4 can be discarded toward the second reproduced image Im2 side.

[0090] As described above, by causing the phase modulator 4 to perform spatial light phase modulation for generating the first reproduced image Im1 in the first reproduced image area on the reproduction surface Sp and generating the second reproduced image Im2 in the second reproduced image area having a position different from that of the first reproduced image area in the image plane direction, and further providing the light shielding unit 7, in the case where the first reproduced image Im1 is displayed as a projected image, the light shielding unit 7 shields the second reproduced image Im2, and projection is not performed by the projection lens 5, it is possible to discard unnecessary light on the side of the second reproduced image Im2. For example, in the case where the actual total light amount of the first reproduced image Im1 exceeds the target total light amount, the total light amount of the image can be appropriately reproduced by discarding the light exceeding the target total light amount to the side of the second reproduced image Im2, or by discarding the light requiring a bending amount exceeding the diffraction limit to the side of the second reproduced image Im2, it is possible to prevent aliasing from occurring in the first reproduced image Im1.

[0091] Therefore, in an image display device that projects a reproduced image Im generated by spatial light phase modulation to display an image, the reproducibility of the displayed image with respect to the target image can be improved.

[0092] (1-3. Specific solutions to Problems I and II)

[0093] Figure 5 It is used to illustrate Figure 1 FIG. 6 is a diagram showing an example of the internal configuration of the control unit 6 shown in FIG. Figure 1 2 and 4. An internal configuration example of the light emitting unit 2, the phase modulator 4 and the control unit 6 is shown in FIG.

[0094] As shown in the figure, the control unit 6 includes a light emitting driving unit 11 , a phase pattern calculating unit 12 , a driving signal generating unit 13 and a modulator driving unit 14 .

[0095] The light emission driving unit 11 drives the light emitting element in the light emitting unit 2 to emit light. Specifically, the light emission driving unit 11 drives the light emitting element to emit light so that the light emission amount of the light emitting unit 2 becomes a constant light emission amount.

[0096] The phase pattern calculation unit 12 calculates the phase modulation pattern of the phase modulator 4 for reproducing the light amount distribution of the input image as the first reproduced image Im1 based on the input image. In addition, in particular, in the case of the present embodiment, the phase pattern calculation unit 12 also calculates the above-mentioned phase modulation pattern for generating the second reproduced image Im2, which will be described again.

[0097] As described above, the Gerchberg-Saxton algorithm, the Wirtinger hologram algorithm, or the like can be used to calculate a phase modulation pattern for generating a reproduced image Im having a desired light amount distribution at a desired position.

[0098] The drive signal generating unit 13 receives the phase modulation pattern calculated by the phase pattern calculating unit 12, and generates a drive signal for the phase modulator 4. That is, it is a drive signal for each pixel of the phase modulator 4 for realizing the phase modulation pattern.

[0099] The modulator driving unit 14 has a driving circuit that drives each pixel of the phase modulator 4 , and drives each pixel of the phase modulator 4 according to the driving signal input from the driving signal generating unit 13 .

[0100] As a result, in the phase modulator 4, spatial light phase modulation according to the phase modulation amount for each pixel represented by the phase modulation pattern is performed.

[0101] First, a method for solving Problem I will be described.

[0102] Problem I basically adopts the following method: a target total light amount of the first reproduced image Im1 is calculated based on the input image, and light corresponding to the light amount determined based on the target total light amount is irradiated to the second reproduced image area (that is, the light is discarded as the second reproduced image Im2). Specifically, without performing spatial light phase modulation on the phase modulator 4, the total light amount of the light amount distribution formed in the first reproduced image area is obtained as the actual total light amount, and the phase modulator 4 is caused to perform spatial light phase modulation for irradiating the second reproduced image area with light corresponding to the difference light amount calculated as the difference between the target total light amount and the actual total light amount.

[0103] As a result, in a case where the actual total light amount of the first reproduced image exceeds the target total light amount, light exceeding the target total light amount can be discarded to the second reproduced image side.

[0104] For problem II, first, the target light quantity distribution of the first reproduced image Im1 is calculated from the input image, and the area on the phase modulator 4 where light cannot be completely bent into the first reproduced image area when the target light quantity distribution is reproduced in the first reproduced image area is designated as a non-modulated area. Then, the phase modulator is made to perform spatial light phase modulation to illuminate the second reproduced image area to the non-modulated area using incident light.

[0105] This prevents the first reproduced image Im1 from generating aliasing.

[0106] (1-4. Processing procedures)

[0107] The phase pattern calculation unit 12 performs Figure 6 The processing shown in the flowchart is performed to implement the above-mentioned method for solving Problem I and Problem II.

[0108] exist Figure 6 In step S101, the phase pattern calculation unit 12 calculates the target total light amount (a) of the first reproduced image Im1 based on the input image, and calculates the total light amount of the light amount distribution formed in the first reproduced image area without performing spatial light phase modulation as the actual total light amount (b).

[0109] Furthermore, as in this example, when the light emission amount of the light emitting unit 2 is assumed to be constant, a predetermined value may be obtained without obtaining the actual total light amount b through calculation.

[0110] In step S102 following step S101, the phase pattern calculation unit 12 calculates the amount of light removed from the first reproduced image region (discarded light amount c) by "ba". Then, in the subsequent step S103, the phase pattern calculation unit 12 calculates a phase modulation pattern (A) for irradiating the second reproduced image region with light corresponding to the discarded light amount c. As a result, a phase modulation pattern for solving problem I is obtained.

[0111] In step S104 after step S103, the phase pattern calculation unit 12 performs the above-mentioned process of specifying the non-reproducible area. That is, when reproducing the light quantity distribution (target light quantity distribution) of the input image in the first reproduced image area, the light on the phase modulator 4 is specified to be unable to be completely bent to the area in the first reproduced image area.

[0112] Figure 7 is a flowchart showing an embodiment of a process of specifying a non-reproducible area.

[0113] Here, in Figure 7 In the description, assume that the following contents are used for the description.

[0114] That is, Figure 8 As shown in A of FIG. 1 , the second reproduced image region is a region covering the periphery of the first reproduced image region. In addition, in the case where the phase modulator 4 does not perform spatial light phase modulation on the incident light, it is assumed that the first reproduced image region is obtained as shown in FIG. Figure 8 The uniform light quantity distribution shown in B (the portion indicated by gray in the figure) is obtained. Figure 8 As shown in FIG. 3C , the target light amount distribution of the first reproduced image Im1 generated in the first reproduced image area is a light amount distribution having a white area only in the lower right portion of the first reproduced image area.

[0115] exist Figure 7 In step S151, the phase pattern calculation unit 12 divides the first reproduced image area into a plurality of areas. Fig. 9 Here, an embodiment of the region division at this time is shown. Here, an embodiment in which the first reproduced image region is divided into six rectangles is shown, but the number and shape of the region divisions are not limited thereto. In addition, the areas of the divided regions may be different.

[0116] As the number of divisions increases, the resolution of the light amount distribution that can be realized can be increased and the light utilization efficiency can be increased, but there is a trade-off relationship in that the amount of calculation of the light beam movement amount increases.

[0117] exist Figure 7 In step S152 following step S151, the phase pattern calculation unit 12 moves each divided region so that the target light amount distribution is reproduced.

[0118] In this embodiment, assuming Figure 8 The target light quantity distribution shown in C is obtained by executing the processing of step S152. Fig.10 Each region is moved as shown in . Here, for the region movement in step S152, optimization calculation such as optimal transfer is used.

[0119] In step S153 following step S152, the phase pattern calculation unit 12 calculates the movement distance of each region. Fig.10 , the movement distance calculated for each region is represented by a single arrow.

[0120] In step S154 following step S153 , the phase pattern calculation unit 12 determines whether there is a region where the movement distance exceeds the allowable light beam movement distance.

[0121] The allowable beam movement distance represents an allowable value determined according to the diffraction limit θ of the phase modulator 4 and the distance d from the phase modulator 4 to the first reproduced image area with respect to the movement amount of the divided area, and is calculated by d·tan θ.

[0122] exist Fig.11 The allowed beam movement distance is indicated by a double-headed arrow and is Fig.10 Each movement distance of each area calculated in is compared with the allowed beam movement distance. Fig.11 The embodiment shows a case where the movement distance of each area where the initial position is the upper left and lower left exceeds the allowed beam movement distance.

[0123] In step S154 , if there is an area whose movement distance exceeds the allowable beam movement distance, the phase pattern calculation unit 12 performs processing of designating the corresponding area as an unreproducible area in step S155 and ends the processing of step S104 (unreproducible area designation processing).

[0124] Meanwhile, in the case where it is determined in step S154 that there is no region where the movement distance exceeds the allowable light beam movement distance, the phase pattern calculation unit 12 ends the process of step S104 .

[0125] Note that the method of specifying the non-reproducible region described here is merely an embodiment and is not limited to this method. For example, a phase modulation pattern for achieving a target light amount distribution of the first reproduced image Im1 may be calculated and the non-reproducible region may be specified based on the phase modulation pattern.

[0126] exist Figure 6 In the process, the phase pattern calculation unit 12 advances the process to step S105 in response to the execution of the process of step S104, and calculates a phase modulation pattern (B) for irradiating the second reproduced image area to the non-reproducible area with incident light.

[0127] Then, in step S106 following step S105, the phase pattern calculation unit 12 calculates a phase modulation pattern (C) for reproducing the target light amount distribution in the first reproduced image area for the pixels other than the non-reproducible area, performs a process of combining and outputting the phase modulation patterns A, B, and C in step S107 thereafter, and terminates. Figure 6 A series of processing shown.

[0128] As a result, the phase modulator 4 is driven according to the phase modulation pattern to solve Problems I and II and obtain the first reproduced image Im1 that reproduces the light amount distribution of the input image. That is, for the first reproduced image Im1, the total light amount of the input image can be appropriately reproduced while preventing the occurrence of aliasing, and the reproducibility of the display image relative to the target image can be improved.

[0129] Here, in order to solve the problem I, it is also conceivable to adopt the following method: adjust the total light intensity of the first reproduced image Im1 by controlling the light emission of the light emitting unit 2, or adjust the total light intensity of the first reproduced image Im1 by setting an amplitude modulator that performs spatial light amplitude modulation on the first reproduced image Im1.

[0130] However, when adjusting using the light emission amount of the light emitting unit 2 , a control circuit for controlling the light emission amount of the light emitting unit 2 needs to be added, and also when adjusting using an amplitude modulator, an amplitude modulator needs to be added.

[0131] By adopting the method of discarding light through spatial light phase modulation of the phase modulator 4 as described above in the method of this embodiment, the need to add a control circuit and an amplitude modulator in solving problem I can be eliminated, and the size and cost of the optical system can be reduced.

[0132] Furthermore, regarding Problem II, in the case where a partial area in the first reproduced image Im1 does not satisfy the maximum diffraction angle restriction of the phase modulator 4 , aliasing may occur.

[0133] Here, the fact that the entire area of ​​the reproduced image satisfies the maximum diffraction angle limit of the phase modulator means that, under the condition that the diffraction limit is applied to the light emission angle of each pixel from the phase modulator and the angle (maximum diffraction angle) is set to the upper limit angle, the light from each pixel can be irradiated to any position in the reproduced image.

[0134] Therefore, it can be considered that, in the case where the entire area in the first reproduced image Im1 satisfies the maximum diffraction angle limit of the phase modulator 4, the process for preventing the occurrence of aliasing is not performed. Specifically, Figure 6 The processing of steps S104 to S106 described in .

[0135] Furthermore, when performing processing for preventing the generation of aliasing, if a local area of ​​the second reproduced image Im2 does not satisfy the maximum diffraction angle limit of the phase modulator 4, it may not be possible to completely discard the aliased light of the first reproduced image Im1 toward the second reproduced image Im2. In this way, it is possible to superimpose the light that cannot be discarded toward the second reproduced image as aliasing on the first reproduced image Im1, and thus it is conceivable to take measures.

[0136] Therefore, as described above, when all the light that will become aliasing of the first reproduced image Im1 cannot be discarded to the second reproduced image Im2 side, it is considered to irradiate the second reproduced image Im2 side in a manner that disperses the light that cannot be discarded in a wide range to the first reproduced image area side.

[0137] <2. Second Embodiment>

[0138] Next, a second embodiment is described. In the second embodiment, a reduction in the reproducibility of the total light amount of the first reproduced image Im1 caused by partial regions in the first reproduced image Im1 and the second reproduced image Im2 that do not satisfy the maximum diffraction angle restriction of the phase modulator 4 is addressed.

[0139] In the following description, the same reference numerals are given to the same parts as those already described, and the description thereof will be omitted.

[0140] Fig.12 This is an explanatory diagram of a case where partial regions in both the first reproduced image Im1 and the second reproduced image Im2 do not satisfy the maximum diffraction angle restriction of the phase modulator 4 .

[0141] exist Fig.12, the shaded range represents the range from the upper end position of the phase modulation region of the phase modulator 4 to the maximum diffraction angle, and the dotted line range represents the range from the lower end position of the phase modulation region of the phase modulator 4 to the maximum diffraction angle.

[0142] Here, for the sake of explanation, only the maximum diffraction angle range in the up and down directions is shown. However, as mentioned above, the required light bending angle in the diagonal direction is the largest. In fact, the maximum diffraction angle range should be considered in each of the up, down, left and right directions.

[0143] In the embodiment in the drawings, the entire first reproduced image area falls within the maximum diffraction angle range from the upper end position of the phase modulation area. This means that when only considering the vertical direction, the light can be completely bent from the upper end position of the phase modulation area to the entire area of ​​the first reproduced image area.

[0144] At the same time, with respect to the maximum diffraction angle range from the lower end position of the phase modulation area, in the first reproduced image area, only a partial area overlaps with the maximum diffraction angle range from the lower end position, and the remaining area deviates from the maximum diffraction angle range from the lower end position. In the first reproduced image area, the area deviated in this way is an area where an image cannot be generated from the lower end position of the phase modulation area.

[0145] In addition, in the accompanying drawings, the entire second reproduced image area falls within the maximum diffraction angle range from the lower end position of the phase modulation area, which means that when considering only in the vertical direction, the light can be completely bent from the lower end position of the phase modulation area to the entire area of ​​the second reproduced image area.

[0146] At the same time, in the second reproduced image area, only a partial area overlaps with the maximum diffraction angle range of the upper end position of the phase modulation area, and the remaining area deviates from the maximum diffraction angle range of the upper end position. Therefore, in the second reproduced image area, the area deviated in this way becomes an area where light cannot be discarded from the upper end position of the phase modulation area.

[0147] Here, the fact that a partial area of ​​the first reproduced image Im1 does not satisfy the maximum diffraction angle restriction means that there is light that cannot be completely bent even if an attempt is made to bend the light into the first reproduced image area. Therefore, in the case where a portion of the first reproduced image Im1 does not satisfy the maximum diffraction angle restriction, even if an attempt is made to reproduce a full-bright image such as a full-white image using the first reproduced image Im1, there may be a case where the image cannot be reproduced.

[0148] On the other hand, the fact that the local area of ​​the second reproduced image Im2 does not satisfy the maximum diffraction angle limit means that even if an attempt is made to discard light to the second reproduced image area, there is light that cannot be completely discarded. In this case, the light that cannot be completely discarded to the second reproduced image area can be emitted to the first reproduced image area side.

[0149] Therefore, for example, even if an attempt is made to reproduce an overall dark image such as an all-black image using the first reproduced image Im1, there may be a case where the image cannot be reproduced.

[0150] Will refer to Fig.13 Describe the specific situation.

[0151] First, in the specification, the maximum total light amount L1 of the first reproduced image, the maximum total light amount L2 of the second reproduced image, the incident light amount Aq on the phase modulator, the target total light amount Bq of the first reproduced image, the total modulated light amount Cq of the first reproduced image and the total modulated light amount Dq of the second reproduced image are used.

[0152] Here, the target total light amount Bq is synonymous with the above-mentioned target total light amount a.

[0153] The maximum total light amount L1 refers to the maximum total light amount of the first reproduced image Im1 when the first reproduced image Im1 is generated by the phase modulator 4 performing spatial light phase modulation. When a pixel in the phase modulator 4 in which light cannot be completely bent to the first reproduced image area is defined as a first inoperable pixel, the maximum total light amount L1 can be obtained by subtracting the incident light amount to the first inoperable pixel from the incident light amount Aq.

[0154] The maximum total light amount L2 refers to the maximum total light amount of the second reproduced image Im2 when the second reproduced image Im2 is generated by the phase modulator 4 performing spatial light phase modulation. When the pixel in the phase modulator 4 in which the light cannot be completely bent to the second reproduced image area is defined as a second non-executable pixel, the maximum total light amount L2 can be obtained by subtracting the incident light amount to the second non-executable pixel from the incident light amount Aq.

[0155] In addition, the modulated total light amounts Cq and Dq represent the total light amounts of at least the first reproduced image Im1 and the second reproduced image Im2 generated by performing the spatial light phase modulation for solving the above-described problem I.

[0156] Here, if Fig.12 As shown, it is assumed that local areas of both the first reproduced image Im1 and the second reproduced image Im2 do not satisfy the maximum diffraction angle limitation of the phase modulator 4, so the maximum total light amounts L1 and L2 both have values ​​smaller than the incident light amount Aq.

[0157] exist Fig.13middle, <1> The case is a case where the target total light amount Bq of the first reproduced image is smaller than the maximum total light amount L1 of the first reproduced image, and the discarded light amount for reproducing the target total light amount Bq is equal to or smaller than the maximum total light amount L2 of the second reproduced image.

[0158] In this case, since light corresponding to an unnecessary light amount among the incident light amount Aq can be completely discarded toward the second reproduced image Im2 side, the target total light amount Bq of the first reproduced image Im1 can be reproduced.

[0159] <2> The case is a case where the target total light amount Bq of the first reproduced image is equal to the maximum total light amount L1 of the first reproduced image, and the discarded light amount for reproducing the target total light amount Bq is equal to or less than the maximum total light amount L2 of the second reproduced image.

[0160] In this case, since light corresponding to an unnecessary light amount among the incident light amount Aq can be completely discarded toward the second reproduced image Im2 side, the target total light amount Bq of the first reproduced image Im1 can be reproduced.

[0161] <3> is a case where the target total light amount Bq of the first reproduced image is greater than the maximum total light amount L1 of the first reproduced image. Since the total light amount exceeding the maximum total light amount L1 cannot be achieved for the first reproduced image Im1, in this case, as shown in the figure, the total modulated light amount Cq of the first reproduced image becomes smaller than the target total light amount Bq, and the brightness of the first reproduced image Im1 becomes darker than the target brightness.

[0162] <4> The case is that the target total light quantity Bq is too small to completely discard the light on the second reproduced image Im2 side. Specifically, (Aq-Bq)>L2, and the excess light used to make the target total light quantity Bq cannot be completely discarded to the second reproduced image Im2 side.

[0163] In this case, the sum of the modulated light amounts Cq of the first reproduced image becomes larger than the target total light amount Bq, and the brightness of the first reproduced image Im1 becomes brighter than the target.

[0164] Therefore, in the second embodiment, as in <3> In the measurement of the case where the modulated light quantity Cq becomes smaller (darker) than the target total light quantity Bq, the following method is adopted: determine whether the maximum total light quantity L1 is smaller than the target total light quantity Bq, and when the maximum total light quantity L1 is smaller than the target total light quantity Bq, control is performed to increase the light emission of the light-emitting unit 2.

[0165] In addition, as <4> In the case where the total modulated light quantity Cq becomes greater than (brighter) the target total light quantity Bq, a method is adopted to determine whether control is performed to reduce the light emission of the light-emitting unit 2 when "(Aq-Bq)>L2".

[0166] Will refer to Fig.14 and Fig.15 A configuration and a processing procedure for realizing the technique of the second embodiment described above are described.

[0167] Fig.14 1 is a diagram for explaining an internal configuration example of a control unit 6A included in an image display device 1A as the second embodiment.

[0168] It should be noted that the image display device 1A as the second embodiment is similar to the image display device 1 of the first embodiment except that a control unit 6A is provided instead of the control unit 6 , and thus redundant description is avoided.

[0169] Control unit 6A and Figure 5 The control unit 6 shown is different in that a light amount control unit 15 is added and a light emission drive unit 11A is provided instead of the light emission drive unit 11 .

[0170] The light emission drive unit 11A is different from the light emission drive unit 11 in that it has a function of adjusting the light emission amount of the light emission unit 2 .

[0171] The light amount control unit 15 performs the following processing based on the input image and the incident light amount information to realize the control method as in the above-described second embodiment. Here, the incident light amount information in the figure is information indicating the incident light amount Aq.

[0172] Fig.15 2 is a flowchart showing an example of processing executed by the light amount control unit 15 .

[0173] First, in step S201, the light amount control unit 15 performs processing to acquire the maximum total light amounts L1 and L2 and the incident light amount Aq. Here, the maximum total light amounts L1 and L2 can be acquired by calculation each time.

[0174] In step S202 following step S201 , the light amount control unit 15 calculates a target total light amount Bq of the first reproduced image based on the input image.

[0175] In step S203 after step S202, the light quantity control unit 15 determines whether the target total light quantity Bq is greater than the maximum total light quantity L1. If the target total light quantity Bq> the maximum total light quantity L1, the light quantity control unit 15 proceeds to step S206 to control the light emitting drive unit 11A to increase the light emitting quantity of the light emitting unit 2, and ends. Fig.15 A series of processing shown.

[0176] As a result, for the above <3> In this case, the total modulated light quantity Cq can be matched with the target total light quantity Bq.

[0177] On the other hand, if it is determined in step S203 that target total light amount Bq>maximum total light amount L1 is not satisfied, the light amount control unit 15 proceeds to step S204 to calculate Aq-Bq, and determines in step S205 whether (Aq-Bq)>L2 is satisfied.

[0178] If (Aq-Bq)>L2, the light amount control unit 15 proceeds to step S207, performs processing of controlling the light emission drive unit 11A to reduce the light emission amount of the light emitting unit 2 as light amount reduction control, and terminates. Fig.15 A series of processing shown.

[0179] As a result, for the above <4> In this case, the total modulated light quantity Cq can be matched with the target total light quantity Bq.

[0180] In the event that it is determined in step S205 that (Aq-Bq)>L2 is not satisfied, the light amount control unit 15 terminates Fig.15 A series of processing shown.

[0181] In addition, in the above description, as <3> and <4> In the case of a problem, an example of adjusting the total light amount of the first reproduced image Im1 by adjusting the light amount of the light-emitting unit 2 is described, but instead, an amplitude modulator that performs spatial light amplitude modulation on the first reproduced image Im1 and uses the amplitude modulator to adjust the total light amount of the first reproduced image Im1 can also be provided.

[0182] Fig.16 1 is a diagram showing a configuration example of an image display device 1B as a modification of the second embodiment using such an amplitude modulator.

[0183] The difference from the image display device 1 of the first embodiment is that an amplitude modulator 20 is added and a control unit 6B is provided instead of the control unit 6 .

[0184] The amplitude modulator 20 includes, for example, a transmissive liquid crystal panel, and is disposed at a position where the spatial light amplitude modulation can be performed on the first reproduced image Im1. Note that, although a transmissive liquid crystal panel is used as the amplitude modulator 20 in this example, other devices such as a reflective liquid crystal panel and a digital micromirror device (DMD) may be adopted as the amplitude modulator 20.

[0185] The control unit 6B is different from the control unit 6 in that a light amount control unit 15B and a modulator driving unit 21 are added.

[0186] The modulator driving unit 21 drives the amplitude modulator 20 based on the control of the light amount control unit 15B. As a result, the total light amount of the first reproduced image Im1 can be adjusted by the amplitude modulator 20.

[0187] The light quantity control unit 15B performs the same operation as the light quantity control unit 15A. Fig.15 However, as the light amount increase control of step S206 and the light amount decrease control of step S207, the light amount control unit 15B controls the modulator drive unit 21 so that the amplitude modulator 20 increases the total light amount of the first reproduced image Im1, and controls the modulator drive unit 21 so that the amplitude modulator 20 decreases the total light amount of the first reproduced image Im1. At this time, as the control of increasing or decreasing the total light amount of the first reproduced image Im1 by the amplitude modulator 20, for example, the control of increasing or decreasing the transmittance of the effective pixel range in the amplitude modulator 20 as a whole is considered.

[0188] Here, in the above description, it has been assumed that some areas do not meet the following Fig.12 The description is given of the maximum diffraction angle limit of the phase modulator 4 in both the first reproduced image Im1 and the second reproduced image Im2 shown. However, as an embodiment of the image display device, as shown in FIG. Fig.17 As shown, a configuration may be adopted in which the entire area of ​​the first reproduced image Im1 satisfies the maximum diffraction angle limit of the phase modulator 4, but a partial area of ​​the second reproduced image Im2 does not satisfy the maximum diffraction angle limit of the phase modulator 4, or as Fig.19 As shown, a partial area of ​​the first reproduced image Im1 does not satisfy the maximum diffraction angle limit of the phase modulator 4 , and the entire area of ​​the second reproduced image Im2 satisfies the maximum diffraction angle limit of the phase modulator 4 .

[0189] Here, if Fig.17 As shown, in the case of adopting a configuration in which the entire area of ​​the first reproduced image Im1 satisfies the maximum diffraction angle limit of the phase modulator 4 and a partial area of ​​the second reproduced image Im2 does not satisfy the maximum diffraction angle limit of the phase modulator 4, the maximum total light amount L1 can be set to be equal to the incident light amount Aq. <3> As in the case of the first reproduced image Im1, the problem of the total modulated light quantity Cq < the target total light quantity Bq caused by the partial area of ​​the first reproduced image Im1 not satisfying the maximum diffraction angle limit of the phase modulator 4 can be prevented (see Fig.18 ).

[0190] Therefore, in this case, you can not execute Fig.15 Among the processes shown are the process of acquiring the maximum total light amount L1 in step S201 and the processes of steps S203 and S206 .

[0191] In addition, Fig.17 In the case of , since the entire area of ​​the first reproduced image Im1 satisfies the maximum diffraction angle restriction of the phase modulator 4, the first reproduced image Im1 is prevented from generating aliasing. Therefore, in this case, it is possible to prevent the execution of the process for preventing the occurrence of aliasing ( Figure 6 4. The processing in steps S104 to S106 in FIG. 4.

[0192] In addition, if Fig.19 As shown, in the case of adopting a configuration in which a part of the area of ​​the first reproduced image Im1 does not satisfy the maximum diffraction angle limit of the phase modulator 4 and the entire area of ​​the second reproduced image Im2 satisfies the maximum diffraction angle limit of the phase modulator 4, the maximum total light amount L2 can be set to be equal to the incident light amount Aq, and therefore, the above-mentioned <4> In the case where it is difficult to discard the light (Aq-Bq) to the second reproduced image Im2 side (see Fig. 20 ).

[0193] Therefore, in this case, Fig.15 The process of acquiring the maximum total light amount L2 in step S201 and the processes of steps S204 , S205 , and S207 may not be performed in the illustrated process.

[0194] In addition, if Fig.21 As shown, the image display device of this embodiment can adopt a configuration in which the entire area of ​​both the first reproduced image Im1 and the second reproduced image Im2 satisfies the maximum diffraction angle restriction of the phase modulator 4 .

[0195] In this case, since the above <3> and <4> The problem (see Fig. 22 ), so it can prevent execution Fig.15 A series of processes shown in .

[0196] In this case, the process for preventing the occurrence of aliasing may not be performed.

[0197] Here, as mentioned above <3> and <4> As a countermeasure to the problem, an example has been described in which the amount of light emitted by the light emitting unit 2 is adjusted by the amplitude modulator 20 and the total light amount of the first reproduced image Im1 is adjusted. However, for example, in the case where the input image is a moving image, a plurality of frames before the input display are input to determine whether there is a frame that does not satisfy the target total light amount Bq, and in the case where there is a frame that does not satisfy the target total light amount Bq, the total light amount of the first reproduced image Im1 is adjusted by spatial light phase modulation for at least a plurality of frames on the past side, and thus, the inconsistency in the brightness of the frame that does not satisfy the target total light amount Bq can be made inconspicuous.

[0198] Specifically, in this case, as mentioned above <3> As measures to the problem, the control unit 6 and the like control the control unit of the phase modulator 4 to input a plurality of frames of images (i.e., perform pre-take), and in the case where there are frames in which the maximum total light quantity L1 of the first reproduced image of the phase modulator 4 is less than the target total light quantity Bq, for the frames that pass through the frames, the light quantity irradiating the second reproduced image area is corrected in an increasing direction by discarding light control.

[0199] Here, the dimming unit is discarded to control the phase modulator 4 to perform spatial light phase modulation for irradiating the second reproduced image area with light corresponding to the light amount determined based on the target total light amount Bq. Specifically, this example is to control the phase modulator 4 to perform spatial light phase modulation for irradiating the second reproduced image area with light corresponding to Aq-Bq.

[0200] In addition, as mentioned above <4> Countermeasures to the problem include, for example, controlling the control unit 6 controls the phase modulator 4 to input a plurality of frames of an image, and in the case where there are frames satisfying "(Aq-Bq)>L2", for frames exceeding this frame, performing processing to correct the amount of light irradiating the second reproduced image area in a decreasing direction by discarding light control.

[0201] Fig.23 An image of a specific process is shown in .

[0202] exist Fig.23 , in the upper part, the relationship between the target total light amount Bq and the total modulated light amount Cq for 9 frames from frame 1 (frame to be currently processed) which is the current frame to frame 9 which is the future side of 8 frames is shown.

[0203] The embodiment of this figure illustrates a case where Bq>L1 is determined in prefetch frame 5, and (Aq-Bq)>L2 is determined in frame 9.

[0204] In response to the determination that Bq>L1 is satisfied for frame 5, a process of correcting the amount of light illuminating the second reproduced image area by discarded light control in the increasing direction is performed for a plurality of frames in period P1 before frame 5. Specifically, the amount of light illuminating the second reproduced image area is corrected to be greater than (Aq-Bq).

[0205] As a result, when a partial area of ​​the first reproduced image Im1 does not meet the maximum diffraction angle limitation and the maximum total light amount L1 of the first reproduced image is less than the incident light amount Aq, in the case where there is a frame (called a dark frame) in which the total modulated light amount of the first reproduced image becomes darker than the target total light amount in the pre-taken frame, the past frame is controlled to be darker than the frame, and the darkness of the dark frame becomes less obvious.

[0206] Furthermore, in response to the determination that (Aq-Bq)>L2 is satisfied for frame 9, correction processing of the amount of light irradiating the second reproduced image area in a decreasing direction by discarding light control is performed for a plurality of frames in a period P2 after frame 9. Specifically, the amount of light irradiating the second reproduced image area is corrected to be less than (Aq-Bq).

[0207] As a result, in the case where there is a frame (called a bright frame) in which the total modulated light amount Cq of the first reproduced image is brighter than the target total light amount Bq in the pre-taken frame because a partial area of ​​the second reproduced image Im2 does not satisfy the maximum diffraction angle limitation, the past frame is controlled to be brighter than this frame, and the brightness of the bright frame becomes less obvious.

[0208] In addition, in the above description, an example is given of a case where the correction of the discarded light amount of the second reproduced image area is performed only on the frames on the past side for dark frames and bright frames. However, the correction of the discarded light amount of the second reproduced image area can be performed not only on the frames on the past side but also on the frames on the future side.

[0209] Furthermore, at this time, by smoothly changing the correction amount of the discarded light amount to the second reproduced image area in the time direction, it is made difficult for the user to notice the change in the total light amount of the first reproduced image Im1.

[0210] Here, in the above description, the maximum diffraction angle limit that satisfies the diffraction limit θ has been mentioned as the diffraction angle limit of the first reproduced image Im1 and the second reproduced image Im2, but the diffraction angle limit of the reproduced image Im can be configured to satisfy the upper limit diffraction angle limit of an angle θS that is smaller than the maximum diffraction angle (diffraction limit θ) of the phase modulator 4.

[0211] Fig.24 The state in which the entire region satisfies the upper limit diffraction angle limit angle θS in both the first reproduced image Im1 and the second reproduced image Im2 is shown.

[0212] Here, the diffraction efficiency of the diffraction grating tends to decrease as the diffraction angle increases.

[0213] Therefore, as described above, the diffraction efficiency of the light used to generate the first reproduced image Im1 or the second reproduced image Im2 can be improved by configuring to satisfy the upper limit diffraction angle limitation at an angle θS smaller than the diffraction limit θ of the phase modulator 4. In particular, by improving the diffraction efficiency of the light used to generate the first reproduced image Im1, the reproducibility of the displayed image relative to the target image can be improved.

[0214] <3. Third Embodiment>

[0215] In the third embodiment, the zero-order light of the phase modulator 4 is processed.

[0216] Here, in the phase modulator 4, zero-order light is generated which cannot perform spatial light phase modulation and regularly reflects incident light, such as reflection from the protective glass surface of the phase modulator 4 or reflection from the black matrix between pixels. When this zero-order light is superimposed on the first reproduced image Im1, this causes image quality degradation such as a decrease in contrast.

[0217] Therefore, in the third embodiment, as in Fig.25 In the image display device 1C shown in , the light flux of the first reproduced image Im1 is emitted in a direction different from the light flux of the zero-order light of the phase modulator 4 .

[0218] In this case, the phase pattern calculation unit 12 in the control unit 6 calculates a phase modulation pattern so that the light flux of the first reproduced image Im1 is emitted to a direction different from the light flux of the zero-order light.

[0219] exist Fig.25 In the embodiment of the invention, the second reproduced image area is illuminated with zero-order light, but if Fig.26 As shown in , a position different from the second reproduced image area in the image plane direction may be irradiated with zero-order light.

[0220] As described above, by emitting the light beam of the first reproduced image Im1 in a direction different from the light beam of the 0th-order light of the phase modulator 4 , it is possible to prevent the 0th-order light of the phase modulator 4 from overlapping the first reproduced image Im1 .

[0221] Therefore, the contrast of the first reproduced image Im1 can be improved. In addition, the reproducibility of the brightness of the input image can be improved.

[0222] <4. Fourth Embodiment>

[0223] The fourth embodiment is an example corresponding to color image display.

[0224] Fig. 27 1 is a diagram showing a configuration example of an image display device 1D as a fourth embodiment.

[0225] As shown in the figure, in the image display device 1D, a light emitting unit 2D emitting a plurality of lights having different wavelength bands is provided instead of the light emitting unit 2. In the present embodiment, a first reproduced image Im1 of each of red (R) light, green (G) light, and blue (B) light is generated by a phase modulator 4, and a composite image thereof is projected by a projection lens 5 to realize color image display. Therefore, the light emitting unit 2D is provided with a light emitting element 2r emitting R light, a light emitting element 2g emitting G light, and a light emitting element 2b emitting B light as light emitting elements.

[0226] In this example, the first reproduced images Im1 of the R light, the G light, and the B light are each generated by a single phase modulator 4. Fig.28 As shown, the phase modulator 4 is divided into regions. Specifically, the phase modulation region (effective pixel region) in the phase modulator 4 is divided into three regions: region Ar1 responsible for generating the reproduced image Im of the B light, region Ar2 responsible for generating the reproduced image Im of the G light, and region Ar3 responsible for generating the reproduced image Im of the R light.

[0227] exist Fig. 27 In this case, the optical system is configured so that each of the R light emitted from the light emitting element 2r, the G light emitted from the light emitting element 2g, and the B light emitted from the light emitting element 2b is incident on the corresponding area Ar of the phase modulator 4.

[0228] As shown in the figure, R light emitted from light emitting element 2r is incident on the front surface of first dichroic mirror 32 through collimator lens 31r, and G light emitted from light emitting element 2g is incident on the rear surface of first dichroic mirror 32 through collimator lens 31g.

[0229] The first dichroic mirror 32 has the property of transmitting R light and reflecting G light. That is, the R light incident from the light emitting element 2r through the collimating lens 31r passes through the first dichroic mirror 32, and the G light incident from the light emitting element 2g through the collimating lens 31g is reflected by the rear surface of the first dichroic mirror 32. As shown in the figure, the R light transmitted through the first dichroic mirror 32 and the G light reflected by the rear surface of the first dichroic mirror 32 are incident on the front surface side of the second dichroic mirror 33.

[0230] The B light emitted from the light emitting element 2b is incident on the rear surface of the second dichroic mirror 33 via the collimating lens 31b. The second dichroic mirror 33 has a characteristic of reflecting the R light and the G light and transmitting the B light. Therefore, the R light and the G light incident from the first dichroic mirror 32 are reflected by the surface of the second dichroic mirror 33, and the B light incident from the light emitting element 2b via the collimating lens 31b is transmitted through the second dichroic mirror 33.

[0231] In the image display device 1D, R light, G light, and B light are emitted from the surface of the second dichroic mirror 33 so that the corresponding light beams are parallel to each other. Fig.28 , the R light, the G light, and the B light emitted from the surface of the second dichroic mirror 33 are incident on the corresponding areas Ar of the phase modulator 4.

[0232] Here, when forming the first reproduced image Im1 as a color image on the reproduction surface Sp using the R light, the G light, and the B light, spatial light phase modulation based on the input image of the corresponding color is performed in the regions Ar1, Ar2, and Ar3. At this time, spatial light phase modulation is performed in each region Ar so that the first reproduced image Im1 of each color is generated in the same first reproduced image region on the reproduction surface Sp. As a result, the first reproduced image Im1 as a color image is obtained on the reproduction surface Sp.

[0233] In the image display device 1D, the R light, the G light, and the B light subjected to the spatial light phase modulation in the respective corresponding regions Ar of the phase modulator 4 are reflected by the reflective mirror 34 and guided to the reproduction surface Sp. At this time, as described above, on the reproduction surface Sp, the images of the respective colors generated by the spatial light phase modulation of each region Ar in the phase modulator 4 are superimposed on the same first reproduction image region, thereby forming a first reproduction image Im1 as a color image.

[0234] The first reproduced image Im1 which is a color image formed on the reproduction surface Sp in this manner is projected onto a predetermined projection surface such as the surface of the screen Sc through the projection lens 5 , and display of a color image is achieved.

[0235] In the image display device 1D, a control unit 6D is provided instead of the control unit 6 .

[0236] Fig.29 is a diagram for explaining an example of the internal configuration of the control unit 6D, and shows Fig. 27 2r, 2g and 2b, the phase modulator 4 and the internal configuration example of the control unit 6D shown in FIG.

[0237] As shown in the figure, the control unit 6D is provided with light emission drive units 11 r , 11 g , and 11 b , phase pattern calculation units 12 r , 12 g , and 12 b , a drive signal generation unit 13D, and a modulator drive unit 14 .

[0238] The light emission driving units 11r, 11g, and 11b drive the light emitting elements of corresponding colors among the light emitting elements 2r, 2g, and 2b to emit light.

[0239] The phase pattern calculation unit 12r inputs the R image among the RGB images input to the control unit 6D, and calculates the phase modulation pattern of the area Ar3 for generating the reproduced image Im of the R light based on the R image. In addition, the phase pattern calculation unit 12g inputs the G image among the RGB images input to the control unit 6D, and calculates the phase modulation pattern of the area Ar2 for generating the reproduced image Im of the G light based on the G image. The phase pattern calculation unit 12b inputs the B image among the RGB images input to the control unit 6D, and calculates the phase modulation pattern of the area Ar1 for generating the reproduced image Im of the B light based on the B image.

[0240] Here, the phase pattern calculation units 12r, 12g, and 12b calculate the target total light quantity Bq of the first reproduced image Im1 based on the input images of each color (each band), and control the phase modulator 4 to perform spatial light phase modulation, which is used to irradiate the second reproduced image area with light corresponding to the light quantity determined according to the target total light quantity Bq of each color.

[0241] Specifically, the phase pattern calculation unit 12r calculates the target total light amount (a) of the R light of the first reproduced image Im1 based on the input R image, calculates the discarded light amount (c) of the R light by "ba" using the actual total light amount (b) of the R light, and calculates the phase modulation pattern (referred to as "Pr1") of the area Ar3 for irradiating the second reproduced image area with light corresponding to the discarded light amount c of the R light. In addition, the phase pattern calculation unit 12r calculates the target light amount distribution of the first reproduced image Im1 of the R light based on the input R image, calculates the phase modulation pattern (referred to as "Pr2") of the area Ar3 for reproducing the target light amount distribution in the first reproduced image area, and outputs the phase modulation pattern obtained by combining the phase modulation patterns Pr1 and Pr2 as the phase modulation pattern of the area Ar3 to the drive signal generation unit 13D.

[0242] And, the phase pattern calculation unit 12g calculates the target total light amount (a) of the G light of the first reproduced image Im1 based on the input G image, calculates the discarded light amount (c) of the G light by "ba" using the actual total light amount (b) of the G light, and calculates the phase modulation pattern (referred to as "Pg1") of the area Ar2 for irradiating the second reproduced image area with light corresponding to the discarded light amount c of the G light. In addition, the phase pattern calculation unit 12g calculates the target light amount distribution of the first reproduced image Im1 of the G light based on the input G image, calculates the phase modulation pattern (referred to as "Pg2") of the area Ar2 for reproducing the target light amount distribution in the first reproduced image area, and outputs the phase modulation pattern obtained by combining the phase modulation patterns Pg1 and Pg2 as the phase modulation pattern of the area Ar2 to the drive signal generation unit 13D.

[0243] The phase pattern calculation unit 12b calculates the target total light amount (a) of the B light of the first reproduced image Im1 based on the input B image, calculates the discarded light amount (c) of the B light by "ba" using the actual total light amount (b) of the B light, and calculates a phase modulation pattern (referred to as "Pb1") of the area Ar1 for irradiating the second reproduced image area with light corresponding to the discarded light amount c of the B light. In addition, the phase pattern calculation unit 12b calculates the target light amount distribution of the first reproduced image Im1 of the B light based on the input B image, calculates the phase modulation pattern (referred to as "Pb2") of the area Ar1 for reproducing the target light amount distribution in the first reproduced image area, and outputs the phase modulation pattern obtained by combining the phase modulation patterns Pb1 and Pb2 as the phase modulation pattern of the area Ar1 to the drive signal generation unit 13D.

[0244] The drive signal generating unit 13D generates a drive signal for the entire effective pixel area of ​​the phase modulator 4 based on the phase modulation patterns of the areas Ar1, Ar2, and Ar3 input from the phase pattern calculating units 12r, 12g, and 12b, and outputs the drive signal to the modulator driving unit 14. The modulator driving unit 14 drives each pixel of the phase modulator 4 based on the drive signal input from the drive signal generating unit 13D.

[0245] With the above configuration, for example, when displaying a color image using multiple types of light with different wavelength bands (such as R, G and B), the amount of light to be discarded can be changed toward the second reproduced image side according to the size of the target total light amount for each wavelength band.

[0246] Therefore, with respect to the display image of the color image, the total light amount of the target image can be appropriately reproduced, and the reproducibility of the display image with respect to the target image can be improved.

[0247] Furthermore, the reproducibility of the white balance of the displayed image can be improved.

[0248] Note that although Fig. 27 A configuration including only one light shielding unit 7 is shown, but in the image display device ID, for example, a plurality of light shielding units 7 may be individually provided for each wavelength band.

[0249] In the fourth embodiment, it is also conceivable that the phase pattern calculation units 12r, 12g, and 12b calculate phase modulation patterns to solve the above-mentioned problem II for the lights of the corresponding wavelength bands.

[0250] Here, for a plurality of types of light having different wavelength bands such as R, G, and B, the second reproduced image area may be set at an arbitrary position.

[0251] However, the shorter the wavelength, the more difficult it is to bend light in the phase modulator 4. Therefore, when the second reproduced image area of ​​the light of the shorter wavelength is positioned, it is desirable to set the second reproduced image area of ​​the light of each wavelength band so that the position in the image plane direction is closer to the irradiation area of ​​the zero-order light of the phase modulator 4.

[0252] Fig.30 A setting example of the second reproduced image area for each of the R, G, and B bands is shown.

[0253] Here, since it is assumed in this embodiment that Fig.28 The area Ar shown in the figure is set, so in the first reproduced image area in the figure, the irradiation area of ​​the zero-order light of R light is the far right, the irradiation area of ​​the zero-order light of G light is the center, and the irradiation area of ​​the zero-order light of B light is the far left.

[0254] exist Fig.30 In the embodiment of the present invention, the distance from the zero-order light irradiation area to the second reproduced image area in the image plane direction is the shortest for the B light having the shortest wavelength.

[0255] In addition, Fig.30 In the embodiment, for G light, the second reproduced image area is set at two positions above and below the first reproduced image area, and the second reproduced image area for R light is set in a C shape.

[0256] As described above, when the second reproduced image area of ​​the short-wavelength light is positioned, the position in the image plane direction is set to be closer to the irradiation area of ​​the zero-order light of the phase modulator 4, so that in the optical axis direction of the short-wavelength light, the light can be completely discarded to the second reproduced image area without greatly separating the second reproduced image area from the phase modulator 4.

[0257] Therefore, the size of the device can be reduced by reducing the size of the optical system.

[0258] It should be noted that in the above-described fourth embodiment, three types of light, namely, R light, G light, and B light, have been exemplified as an example of “a plurality of types of light having different wavelength bands” incident on the phase modulator 4 for image reproduction. However, “a plurality of types of light having different wavelength bands” is not limited to R light, G light, and B light, and may be light of intermediate colors such as cyan and magenta.

[0259] Furthermore, the number of "a plurality of types of light having different wavelength bands" is not limited to three, and only needs to be at least two or more. That is, the number of divisions of the region Ar in the phase modulator 4 is not limited to three, as long as it is two or more.

[0260] In addition, in the above description, the division of the region Ar in the phase modulator 4 is assumed to be equally divided, but may be unequally divided.

[0261] Furthermore, in order to realize color image display, it is also possible to adopt a configuration in which the phase modulator 4 is provided individually for each of a plurality of types of light having different wavelength bands.

[0262] In this case, it is conceivable that each phase modulator 4 adopts a configuration in which a reproduced image is generated for incident light of a corresponding wavelength band, and the reproduced images are combined and projected by the projection lens 5 .

[0263] <5. Modifications>

[0264] Although various embodiments according to the present technology have been described above, the present technology is not limited to the specific embodiments described above, and various modified configurations may be employed.

[0265] For example, Fig.31 As shown, it is conceivable to set multiple second reproduced image areas at different positions in the image plane direction. In this case, the control unit that controls the phase modulator 4 causes the phase modulator 4 to perform spatial light phase modulation for generating the second reproduced image Im2 in each second reproduced image area.

[0266] Specifically, in Fig.31 In the embodiment of , the second reproduced image area is set at two positions on the upper side and the lower side of the first reproduced image area, and the phase modulation area of ​​the phase modulator 4 is divided into an upper area ArU and a lower area ArD. Then, the upper area ArU is responsible for irradiating the discarded light to the upper second reproduced image area, and the lower area ArD is responsible for irradiating the discarded light to the lower second reproduced image area.

[0267] Here, if Fig.32 As shown, when only one second reproduced image area is set, in order to completely discard the light to the second reproduced image area from the balance of the diffraction limit θ of the phase modulator 4, it is necessary to ensure a specific distance in the optical axis direction from the phase modulator 4 to the second reproduced image area.

[0268] At the same time, if Fig.31 As shown, Fig.32 Compared with the case shown in which light is discarded to a second reproduced image area, the distance from the phase modulator 4 to the second reproduced image area in the optical axis direction can be shortened.

[0269] Therefore, the size of the device can be reduced by reducing the size of the optical system.

[0270] In addition, by discarding light in each of the plurality of second reproduced image regions, light can be discarded while avoiding regions where it is desired to suppress temperature rise. In addition, it is possible to prevent stray light from being generated when light of the second reproduced image strikes a region where a black coating is not applied.

[0271] Furthermore, with regard to the light shielding unit 7, in the case where a temperature rise due to light absorption becomes a problem, such as Fig.33 As shown, the heat sink 35 may be provided on the back side (ie, the side opposite to the light incident surface) of the light shielding unit 7. In addition, the heat sink 35 may be integrated with the light shielding unit 7.

[0272] Furthermore, it is desirable that the light shielding unit 7 is composed of a material having a low thermal expansion coefficient, or is disposed at a position away from a component holding an optical component and positional accuracy or the like is required, thereby reducing the influence on the component.

[0273] Furthermore, for the second reproduced image Im2, the in-plane light amount distribution can be determined from the thermal resistance distribution of the light shielding unit 7. For example, it is conceivable that the light amount distribution makes the light amount larger in a portion with lower thermal resistance than in a portion with higher thermal resistance.

[0274] As a result, deformation of the optical system due to equalization of thermal expansion can be suppressed. In addition, energy saving of cooling devices such as fans can be achieved by improving waste heat efficiency, miniaturizing the housing, and suppressing component degradation.

[0275] In addition, in the above description, the reflective liquid crystal panel is used as the phase modulator 4 , but a device other than the reflective liquid crystal panel may be used as the phase modulator 4 .

[0276] For example, a transmissive liquid crystal panel may be used. In addition, the present invention is not limited to liquid crystal panels, and devices other than liquid crystal panels may be used, such as devices using microelectromechanical systems (MEMS) (e.g., devices configured to adjust the height of the mirror for each pixel).

[0277] <6. Overview of Implementation Methods>

[0278] As described above, the image display device (1, 1A, 1B, 1C and 1D) as an embodiment includes: a light-emitting unit (2 and 2D) that emits light; a phase modulator (4) that performs spatial light phase modulation on incident light from the light-emitting unit; a control unit (6, 6A, 6B and 6D) that causes the phase modulator to perform spatial light phase modulation, as a reproduced image generated by performing spatial light phase modulation on the incident light, the spatial light phase modulation is used to generate a first reproduced image in a first reproduced image area and a second reproduced image in a second reproduced image area that is different from the first reproduced image area in the image plane direction; a projection lens (5) that projects the first reproduced image; and a shading unit (7), the shading unit (7) shields the second reproduced image so that the second reproduced image is not projected by the projection lens.

[0279] Therefore, when the first reproduced image is displayed as a projected image, unnecessary light can be discarded to the second reproduced image side. For example, when the actual total light amount of the first reproduced image exceeds the target total light amount, the total light amount of the image can be appropriately reproduced by discarding the light exceeding the target total light amount to the second reproduced image side, or aliasing can be prevented from occurring in the first reproduced image by discarding the light that requires a bending amount exceeding the diffraction limit to the second reproduced image side.

[0280] Therefore, in an image display device that projects a reproduced image generated by spatial light phase modulation to display an image, the reproducibility of the displayed image can be improved with respect to the target image.

[0281] Furthermore, in the image display device as an embodiment, the control unit calculates a target total light amount of the first reproduced image based on the input image, and causes the phase modulator to perform spatial light phase modulation for illuminating the second reproduced image area with light corresponding to a light amount determined based on the target total light amount.

[0282] This makes it possible to change the amount of light to be discarded toward the second reproduced image side in accordance with the size of the target total light amount.

[0283] Therefore, with respect to the display image, the total light amount of the target image can be appropriately reproduced, and in that respect, the reproducibility of the display image with respect to the target image can be improved.

[0284] In addition, since the adjustment of the total light amount can be achieved through a separate phase modulator, there is no need to control the light emission of the light source of the incident light in order to adjust the total light amount, or there is no need to separately set up an amplitude modulator that performs spatial light amplitude modulation on the first reproduced image to control the total light amount of the first reproduced image.

[0285] As a result, there is no need to provide a configuration for controlling the light emission amounts of the light source and the amplitude modulator, the number of device components can be reduced, and the cost and size of the device can be reduced.

[0286] In addition, in the image display device as an embodiment, without performing spatial light phase modulation of the phase modulator on the incident light, the control unit obtains the total light amount of the light amount distribution formed in the first reproduced image area as the actual total light amount, and causes the phase modulator to perform spatial light phase modulation for irradiating the second reproduced image area with light corresponding to the difference light amount calculated as the difference between the target total light amount and the actual total light amount.

[0287] As a result, in a case where the actual total light amount of the first reproduced image exceeds the target total light amount, light exceeding the target total light amount can be discarded to the second reproduced image side.

[0288] Therefore, with respect to the display image, the total light amount of the target image can be appropriately reproduced, and in that respect, the reproducibility of the display image with respect to the target image can be improved.

[0289] Furthermore, in the image display device as an embodiment, the entire area of ​​the first reproduced image satisfies the maximum diffraction angle restriction of the phase modulator (see Fig.17 , Fig.21 as well as Fig.24 ).

[0290] The fact that the entire area of ​​the first reproduced image satisfies the maximum diffraction angle condition means that, in the case of performing spatial light phase modulation in order to reproduce the light amount distribution of the target image, all light can be completely bent in the first reproduced image area, so that aliasing can be prevented from occurring in the first reproduced image. Therefore, there is no need to perform processing for discarding light to the second reproduced image side in order to prevent aliasing.

[0291] Furthermore, in the image display device as an embodiment, the entire area of ​​the second reproduced image satisfies the maximum diffraction angle restriction of the phase modulator (see Fig.19 , Fig.21 as well as Fig.24 ).

[0292] The fact that the entire area of ​​the second reproduced image satisfies the maximum diffraction angle condition means that there is no limit to the amount of light to be discarded to the second reproduced image side.

[0293] Therefore, a completely black image can be reproduced by the first reproduced image (when measures are taken against superposition of zero-order light).

[0294] Furthermore, in the image display device as an embodiment, the entire area of ​​the first reproduced image and the second reproduced image satisfies the maximum diffraction angle restriction of the phase modulator (see Fig.21 and Fig.24 ).

[0295] As a result, aliasing can be prevented from occurring in the first reproduced image, and a completely black image can be reproduced by the first reproduced image.

[0296] Furthermore, in the image display device as an embodiment, the entire area of ​​the first reproduced image satisfies the upper limit diffraction angle limit which is smaller than the angle of the maximum diffraction angle of the phase modulator (see Fig.24 ).

[0297] Therefore, the diffraction efficiency of the light used to generate the first reproduced image can be improved, and the reproducibility of the displayed image with respect to the target image can be improved.

[0298] In addition, in the image display device as an embodiment, the control unit calculates the target light quantity distribution of the first reproduced image based on the input image, and when reproducing the target light quantity distribution in the first reproduced image area, designates an area on the phase modulator that cannot completely bend light into the first reproduced image area as a non-modulated area, and causes the phase modulator to perform spatial light phase modulation for irradiating the second reproduced image area to the non-modulated area using incident light.

[0299] This prevents aliasing from occurring in the first reproduced image.

[0300] Therefore, the reproducibility of the displayed image can be improved with respect to the target image.

[0301] Furthermore, in the image display device (1C) as an embodiment, the light flux of the first reproduced image is emitted in a direction different from the light flux of the zero-order light of the phase modulator (see Fig.25 and Fig.26 ).

[0302] This prevents the zero-order light of the phase modulator from being superimposed on the first reproduced image.

[0303] Therefore, the contrast of the first reproduced image can be improved. In addition, the reproducibility of the brightness of the input image can be improved.

[0304] In addition, in the image display device (1A and 1B) as an embodiment, a partial area of ​​the first reproduced image does not meet the maximum diffraction angle limit of the phase modulator, the control unit (6A, 6B) calculates the target total light amount of the first reproduced image based on the input image, and when the maximum total light amount of the first reproduced image of the phase modulator is less than the target total light amount, the amplitude modulator (20) that performs spatial light amplitude modulation on the first reproduced image performs control to increase the light emission of the light-emitting unit or increase the total light amount of the first reproduced image.

[0305] As a result, in response to a situation predicted that the total modulated light amount of the first reproduced image becomes darker than the target total light amount due to the fact that a partial area of ​​the first reproduced image does not satisfy the maximum diffraction angle limitation and the maximum total light amount of the first reproduced image becomes smaller than the incident light amount, the total light amount of the first reproduced image can be increased by controlling the light emitting unit or the amplitude modulator.

[0306] Therefore, even in the case where a partial area of ​​the first reproduced image does not satisfy the maximum diffraction angle limitation and the maximum total light amount of the first reproduced image is less than the incident light amount, the total light amount of the target image can be appropriately reproduced for the display image, and the reproducibility of the display image relative to the target image can be improved.

[0307] In addition, in an image display device as an embodiment, a control unit (1A and 1B) calculates a target total light amount of a first reproduced image based on an input image, and controls a phase modulator to perform spatial light phase modulation, wherein the spatial light phase modulation is used to illuminate a second reproduced image area with light corresponding to a light amount determined based on the target total light amount, and a partial area of ​​the second reproduced image does not satisfy a maximum diffraction angle limit of the phase modulator, and when Aq represents the incident light amount of the phase modulator, Bq represents the target total light amount, and L2 represents the maximum total light amount of the second reproduced image of the phase modulator, when "(Aq-Bq)>L2" is satisfied, the control unit controls the amplitude modulator that performs spatial light amplitude modulation on the first reproduced image to reduce the light amount of the light-emitting unit or controls to reduce the total light amount of the first reproduced image.

[0308] As a result, since the maximum diffraction angle limit is not satisfied in some areas of the second reproduced image and the light used to achieve the target total light amount cannot be completely discarded, when it is predicted that the total modulated light amount of the first reproduced image becomes brighter than the target total light amount, the total light amount of the first reproduced image can be reduced by controlling the light-emitting unit or the amplitude modulator.

[0309] Therefore, even in a case where light used to achieve the target total light amount cannot be completely discarded because a partial area of ​​the second reproduced image does not satisfy the maximum diffraction angle limit, the total light amount of the target image can be appropriately reproduced for the display image, and the reproducibility of the display image relative to the target image can be improved.

[0310] Furthermore, in the image display device as an embodiment, the control unit calculates a target total light amount of a first reproduced image based on an input image, and performs discarded light control for causing a phase modulator to perform spatial light phase modulation for irradiating a second reproduced image region with light corresponding to a light amount determined based on the target total light amount, a partial region of the first reproduced image does not satisfy a maximum diffraction angle limit of the phase modulator, and the control unit is configured to, in the case of a plurality of frames of the input image, and there is a frame in which the maximum total light amount of the first reproduced image of the phase modulator is less than the target total light amount, correct the amount of light irradiating the second reproduced image region by the discarded light control in an increasing direction for frames exceeding the frame (see Fig.23 ).

[0311] As a result, in a case where a partial area of ​​the first reproduced image does not satisfy the maximum diffraction angle limitation and the maximum total light amount of the first reproduced image is less than the incident light amount, in a case where there is a frame (dark frame) in which the total modulated light amount of the first reproduced image becomes darker than the target total light amount in the pre-taken frame, the past frame is controlled to be darker than the frame, and the darkness of the dark frame becomes less obvious.

[0312] Therefore, the reproducibility of the displayed image can be improved with respect to the target image.

[0313] In addition, in an image display device as an embodiment, a control unit calculates a target total light amount of a first reproduced image based on an input image, and performs discarded light control to cause a phase modulator to perform spatial light phase modulation, the spatial light phase modulation being used to illuminate a second reproduced image area with light corresponding to an amount of light determined based on the target total light amount, a partial area of ​​the second reproduced image not satisfying a maximum diffraction angle limit of the phase modulator, and the control unit is configured such that in the case of multiple frames of the input image, and when Aq represents the amount of incident light to the phase modulator, Bq represents the target total light amount, and L2 represents the maximum total light amount of the second reproduced image of the phase modulator, there is a frame satisfying "(Aq-Bq)>L2", and for the frame passing through the frame, the amount of light irradiating the second reproduced image area is corrected in a reducing direction by discarded light control.

[0314] As a result, in the case where there is a frame (bright frame) in which the total modulated light amount of the first reproduced image becomes brighter than the target total light amount in the pre-taken frame due to a partial area of ​​the second reproduced image not satisfying the maximum diffraction angle limitation, the past frame is controlled to be brighter than the frame, and the brightness of the bright frame can be made less obvious.

[0315] Therefore, the reproducibility of the displayed image can be improved with respect to the target image.

[0316] In addition, the image display device (1D) according to the embodiment is configured to generate a first reproduced image of each wavelength band in the same first reproduced image area by performing spatial light phase modulation on multiple types of light with different wavelength bands, and the control unit (6D) controls to calculate the target total light amount of the first reproduced image based on the input image of each band, and performs spatial light phase modulation, which is used to illuminate the second reproduced image area with light corresponding to the light amount determined based on the target total light amount of each band.

[0317] As a result, for example, in the case of displaying a color image using multiple types of light having different wavelength bands such as R, G and B, the amount of light to be discarded can be changed toward the second reproduced image side according to the size of the target total light amount for each wavelength band.

[0318] Therefore, with respect to the display image of the color image, the total light amount of the target image can be appropriately reproduced, and the reproducibility of the display image with respect to the target image can be improved.

[0319] Furthermore, the reproducibility of the white balance of the displayed image can be improved.

[0320] Furthermore, in the image display device as an embodiment, the second reproduced image region is determined for each wavelength band, and the second reproduced image region having light of a shorter wavelength has a position closer to the irradiation region of the zero-order light of the phase modulator in the image plane direction (see Fig.30 ).

[0321] The diffraction angle in the phase modulator depends on the wavelength of the incident light, and light with a shorter wavelength is more difficult to bend. According to the above structure, for short-wavelength light, the second reproduced image area will not be greatly separated from the phase modulator in the optical axis direction, and the light can be completely discarded to the second reproduced image area.

[0322] Therefore, the size of the device can be reduced by reducing the size of the optical system.

[0323] Furthermore, in the image display device as an embodiment, a plurality of second reproduced image areas are defined at different positions in the image plane direction, and the control unit causes the phase modulator to perform spatial light phase modulation for generating a second reproduced image in each second reproduced image area (see Fig.31 ).

[0324] As described above, by generating a second reproduced image in each of a plurality of second reproduced image areas in the direction of the image plane, i.e., by discarding light in each of a plurality of second reproduced image areas, the distance from the phase modulator to the second reproduced image area in the direction of the optical axis can be shortened compared to a case where light in one second reproduced image area is discarded.

[0325] Therefore, the size of the device can be reduced by reducing the size of the optical system.

[0326] In addition, by discarding light in each of the plurality of second reproduced image regions, light can be discarded while avoiding regions where it is desired to suppress temperature rise. In addition, it is possible to prevent stray light from being generated when light of the second reproduced image strikes a region where a black coating is not applied.

[0327] It should be noted that the effects described in this specification are merely embodiments and are not limited, and other effects may be provided.

[0328] <7. This technology>

[0329] The present technology can also adopt the following configurations. (1)

[0331] An image display device, comprising:

[0332] a light emitting unit, emitting light;

[0333] a phase modulator that performs spatial optical phase modulation on incident light from the light emitting unit;

[0334] a control unit that causes the phase modulator to perform spatial light phase modulation as a reproduced image generated by the spatial light phase modulation with respect to the incident light, the spatial light phase modulation being used to generate a first reproduced image in a first reproduced image region and a second reproduced image in a second reproduced image region at a position different from the first reproduced image region in the image plane direction;

[0335] a projection lens that projects a first reproduced image; and

[0336] The light shielding unit shields the second reconstructed image so that the projection lens does not project the second reconstructed image. (2)

[0338] According to the image display device of (1),

[0339] Wherein, the control unit is configured as:

[0340] A target total light amount of the first reproduced image is calculated based on the input image, and the phase modulator is caused to perform spatial light phase modulation for illuminating the second reproduced image area with light corresponding to a light amount determined based on the target total light amount. (3)

[0342] According to the image display device of (2),

[0343] Wherein, the control unit is configured as:

[0344] Without performing spatial light phase modulation on the incident light through the phase modulator, the total light amount of the light amount distribution formed in the first reproduced image area is obtained as the actual total light amount, and the phase modulator is caused to perform spatial light phase modulation, which is used to illuminate the second reproduced image area with light corresponding to the difference light amount calculated as the difference between the target total light amount and the actual total light amount. (4)

[0346] The image display device according to any one of (1) to (3),

[0347] The entire area of ​​the first reconstructed image satisfies the maximum diffraction angle limit of the phase modulator. (5)

[0349] The image display device according to any one of (1) to (3),

[0350] The entire area of ​​the second reconstructed image satisfies the maximum diffraction angle limit of the phase modulator. (6)

[0352] The image display device according to any one of (1) to (3),

[0353] The entire area of ​​the first reconstructed image and the second reconstructed image meets the maximum diffraction angle limit of the phase modulator. (7)

[0355] The image display device according to any one of (1) to (3),

[0356] Here, the entire area of ​​the first reproduced image satisfies the upper diffraction angle limit which is smaller than the maximum diffraction angle of the phase modulator. (8)

[0358] The image display device according to any one of (1), (2), (3) and (5),

[0359] Wherein, the control unit is configured as:

[0360] A target light quantity distribution of a first reproduced image is calculated based on an input image; when the target light quantity distribution is reproduced in the first reproduced image area, an area in the phase modulator that cannot completely bend light into the first reproduced image area is designated as a non-modulated area; and the phase modulator is caused to perform spatial light phase modulation, and the spatial light phase modulation is used to use incident light to illuminate the second reproduced image area to the non-modulated area. (9)

[0362] The image display device according to any one of (1) to (8),

[0363] Here, the light flux of the first reproduced image is emitted in a direction different from the light flux of the zero-order light of the phase modulator. (10)

[0365] The image display device according to any one of (1), (2), (3), (5) and (8),

[0366] wherein a partial area of ​​the first reconstructed image does not satisfy the maximum diffraction angle limit of the phase modulator, and

[0367] The control unit is configured as:

[0368] A target total light amount of a first reproduced image is calculated based on an input image, and when the maximum total light amount of the first reproduced image of the phase modulator is less than the target total light amount, control is performed by the amplitude modulator that performs spatial light amplitude modulation on the first reproduced image to increase the light amount of the light-emitting unit or control is performed to increase the total light amount of the first reproduced image. (11)

[0370] The image display device according to any one of (1), (2), (3), (4) and (7),

[0371] Wherein, the control unit is configured as:

[0372] calculating a target total light amount of a first reproduced image based on an input image, and performing control so that a phase modulator performs spatial light phase modulation for irradiating a second reproduced image area with light corresponding to a light amount determined based on the target total light amount,

[0373] A partial area of ​​the second reconstructed image does not meet the maximum diffraction angle limit of the phase modulator, and

[0374] The control unit is configured as

[0375] When Aq represents the amount of incident light to the phase modulator, Bq represents the target total light amount, and L2 represents the maximum total light amount of the second reproduced image by the phase modulator, and "(Aq-Bq)>L2" is satisfied, control of reducing the light amount of the light-emitting unit or control of reducing the total light amount of the first reproduced image is performed through the amplitude modulator. (12)

[0377] The image display device according to any one of (1), (2), (3), (5) and (8),

[0378] Wherein, the control unit is configured as:

[0379] calculating a target total light amount of a first reproduced image based on an input image, and performing discarded light control that causes a phase modulator to perform spatial light phase modulation for irradiating a second reproduced image region with light corresponding to a light amount determined based on the target total light amount,

[0380] A partial area of ​​the first reconstructed image does not meet the maximum diffraction angle limit of the phase modulator, and

[0381] The control unit is configured to,

[0382] In the case where multiple frames of the input image exist and there is a frame in which the maximum total light amount of the first reproduced image passing through the phase modulator is less than the target total light amount, for the frames passing through the frame, the amount of light illuminating the second reproduced image area is corrected in an increasing direction by discarding light control. (13)

[0384] The image display device according to any one of (1), (2), (3), (4) and (7),

[0385] Wherein, the control unit is configured as:

[0386] calculating a target total light amount of a first reproduced image based on an input image, and performing discarded light control that causes a phase modulator to perform spatial light phase modulation for irradiating a second reproduced image region with light corresponding to a light amount determined based on the target total light amount,

[0387] A partial area of ​​the second reconstructed image does not meet the maximum diffraction angle limit of the phase modulator, and

[0388] The control unit is configured to,

[0389] In multiple frames of the input image, and when Aq represents the amount of incident light to the phase modulator, Bq represents the target total light amount, and L2 represents the maximum total light amount of the second reproduced image performed by the phase modulator, there are frames that satisfy "(Aq-Bq)>L2", for frames exceeding this frame, the amount of light irradiating the second reproduced image area is corrected in a decreasing direction by discarding light control. (14)

[0391] The image display device according to any one of (1) to (13),

[0392] wherein the image display device is configured to generate a first reproduced image for each wavelength band in the same first reproduced image region by performing spatial optical phase modulation on a plurality of types of light having different wavelength bands, and

[0393] The control unit is configured as:

[0394] A target total light amount of a first reproduced image is calculated based on an input image for each wavelength band, and control is performed to perform spatial light phase modulation for irradiating a second reproduced image area with light corresponding to a light amount determined based on the target total light amount for each wavelength band. (15)

[0396] According to the image display device of (14),

[0397] wherein a second reproduced image region is determined for each wavelength band, and

[0398] When the second reproduced image region has shorter wavelength light, the position in the image plane direction is set closer to the irradiation region of the zero-order light of the phase modulator. (16)

[0400] The image display device according to any one of (1) to (15),

[0401] wherein the plurality of second reproduced image regions are defined at different positions in the image plane direction, and

[0402] The control unit is configured as:

[0403] The phase modulator is caused to perform spatial light phase modulation for generating a second reproduced image in each second reproduced image region.

[0404] Reference Symbols List

[0405] 1. 1A, 1B, 1C, 1D image display device

[0406] 2 light emitting units

[0407] 3 Collimating lens

[0408] 4-phase modulator

[0409] 5Projection lens

[0410] 6.6A, 6B, 6D control unit

[0411] 7 Shading units

[0412] Im reproducing the image

[0413] Sc screen

[0414] Sp reproduction surface

[0415] Im1 first reproduced image

[0416] Im2 second reproduced image

[0417] 11, 11A, 11r, 11g, 11b light driving unit

[0418] 12, 12r, 12g, 12b phase pattern calculation unit

[0419] 13. 13D drive signal generation unit

[0420] 14 Modulator drive unit

[0421] 15, 15B light control unit

[0422] 20Amplitude modulator

[0423] 21 Modulator Driver Unit

[0424] 2r, 2g, 2b light emitting elements

[0425] 31r, 31g, 31b collimating lenses

[0426] 32First dichroic mirror

[0427] 33 Second dichroic mirror

[0428] 34 Reflector

[0429] Ar, Ar1, Ar2, Ar3 region

[0430] ArU upper region

[0431] ArD lower area

[0432] 35 Radiator

Claims

1. An image display device, comprising: a light emitting unit, emitting light; a phase modulator that performs spatial optical phase modulation on incident light from the light emitting unit; a control unit that causes the phase modulator to perform spatial light phase modulation for generating a first reproduced image in a first reproduced image region and a second reproduced image in a second reproduced image region whose position in an image plane direction is different from that of the first reproduced image region as reproduced images generated by the spatial light phase modulation with respect to the incident light; a projection lens for projecting the first reconstructed image; as well as The light shielding unit shields the second reproduced image so that the second reproduced image is not projected by the projection lens.

2. The image display device according to claim 1, in, The control unit is configured to calculate a target total light amount of the first reproduced image based on an input image, and cause the phase modulator to perform spatial light phase modulation for illuminating the second reproduced image area with light corresponding to a light amount determined based on the target total light amount.

3. The image display device according to claim 2, in, The control unit is configured to obtain a total light amount of the light amount distribution formed in the first reproduced image area as an actual total light amount when the phase modulator does not perform the spatial light phase modulation on the incident light, and to cause the phase modulator to perform spatial light phase modulation to illuminate the second reproduced image area with light corresponding to a difference light amount calculated as the difference between the target total light amount and the actual total light amount.

4. The image display device according to claim 1, in, The entire area of ​​the first reconstructed image satisfies the maximum diffraction angle limit of the phase modulator.

5. The image display device according to claim 1, in, The entire area of ​​the second reproduced image satisfies the maximum diffraction angle limit of the phase modulator.

6. The image display device according to claim 1, in, The entire area of ​​the first reconstructed image and the second reconstructed image satisfies the maximum diffraction angle limitation of the phase modulator.

7. The image display device according to claim 1, in, The entire area of ​​the first reproduced image satisfies the restriction of an upper limit diffraction angle that is smaller than the maximum diffraction angle of the phase modulator.

8. The image display device according to claim 1, in, The control unit is configured to calculate a target light quantity distribution of the first reproduced image based on an input image; and when reproducing the target light quantity distribution in the first reproduced image area, designate an area in the phase modulator that cannot completely bend light to the first reproduced image area as a non-modulatable area; and causing the phase modulator to perform spatial light phase modulation for illuminating the second reproduced image area with the light incident on the non-modulatable area.

9. The image display device according to claim 1, in, The light flux of the first reproduced image is emitted in a direction different from the light flux of the zero-order light of the phase modulator.

10. The image display device according to claim 1, in, A partial area of ​​the first reproduced image does not satisfy the maximum diffraction angle limit of the phase modulator, and The control unit is configured to calculate a target total light amount of the first reproduced image based on an input image, and, when a maximum total light amount of the first reproduced image passing through the phase modulator is less than the target total light amount, perform control to increase the light amount of the light emitting unit or perform control to increase the total light amount of the first reproduced image through an amplitude modulator that performs spatial light amplitude modulation on the first reproduced image.

11. The image display device according to claim 1, in, the control unit being configured to calculate a target total light amount of the first reproduced image based on an input image, and to perform control so that the phase modulator performs spatial light phase modulation for irradiating the second reproduced image area with light corresponding to a light amount determined based on the target total light amount, A partial area of ​​the second reproduced image does not satisfy the maximum diffraction angle limit of the phase modulator, and The control unit is configured to control the amount of light emitted by the light-emitting unit or to control the total amount of light emitted by the first reproduced image by using an amplitude modulator that performs spatial light amplitude modulation on the first reproduced image, when "(Aq-Bq)>L2" is satisfied when Aq represents the amount of light incident on the phase modulator, Bq represents the target total amount of light, and L2 represents the maximum total amount of light of the second reproduced image that passes through the phase modulator.

12. The image display device according to claim 1, in, the control unit being configured to calculate a target total light amount of the first reproduced image based on an input image, and to perform discarded light control that causes the phase modulator to perform spatial light phase modulation for irradiating the second reproduced image area with light corresponding to a light amount determined based on the target total light amount, A partial area of ​​the first reproduced image does not satisfy the maximum diffraction angle limit of the phase modulator, and The control unit is configured to, when there are multiple frames of the input image and there is a frame in which the maximum total light amount of the first reproduced image passing through the phase modulator is less than the target total light amount, correct the light amount irradiating the second reproduced image area by discarding light control in an increasing direction for the frames passing through the frame.

13. The image display device according to claim 1, in, the control unit being configured to calculate a target total light amount of the first reproduced image based on an input image, and to perform discarded light control that causes the phase modulator to perform spatial light phase modulation for irradiating the second reproduced image area with light corresponding to a light amount determined based on the target total light amount, A partial area of ​​the second reproduced image does not satisfy the maximum diffraction angle limit of the phase modulator, and The control unit is configured to, in a case where there are multiple frames of the input image and there is a frame satisfying "(Aq-Bq)>L2" when Aq represents the amount of light incident on the phase modulator, Bq represents the target total light amount, and L2 represents the maximum total light amount of the second reproduced image passing through the phase modulator, correct the amount of light irradiating the second reproduced image area by discarding light control in a decreasing direction for the frames passing through the frame.

14. The image display device according to claim 1, in, The image display device is configured to generate a first reproduced image for each wavelength band in a same first reproduced image area by performing spatial optical phase modulation on a plurality of types of light having different wavelength bands, and The control unit is configured to calculate a target total light amount of the first reproduced image based on an input image for each wavelength band, and to perform control to perform spatial light phase modulation for irradiating the second reproduced image area with light corresponding to a light amount determined based on the target total light amount for each wavelength band.

15. The image display device according to claim 14, in, determining the second reproduced image region for each wavelength band, and When the second reproduced image region has shorter wavelength light, the position in the image plane direction is set closer to the irradiation region of the zero-order light of the phase modulator.

16. The image display device according to claim 1, in, A plurality of the second reproduced image areas are defined at different positions in the image plane direction, and The control unit is configured to cause the phase modulator to perform spatial light phase modulation for generating the second reproduced image in each second reproduced image region.

Images