Liquid crystal panel, imaging system module and imaging apparatus

Abstract

To improve the practicality more in range finding technique based upon a captured image.SOLUTION: A liquid crystal panel is used which forms apertures controlling incident light. The liquid crystal panel includes a first liquid crystal cell and a second liquid crystal cell which are a guest-host type requiring no polarizer. The first liquid crystal cell and second liquid crystal cell are arranged having cell surfaces in contact or closely. The guest-host liquid crystal of the first liquid crystal cell may be configured to have, as alignment directions, a first direction, orthogonal to the optical axis direction of the liquid crystal panel, and the optical axis direction. The guest-host liquid crystal of the second liquid crystal may be configured to have, as alignment directions, a second direction, orthogonal to both the optical axis direction, and the first direction and the optical axis direction. The liquid crystal panel has alignment direction in respective regions of the guest-host liquid crystal controlled with an electric field to form the same aperture patterns on the first and second liquid crystal cells. An aperture for imaging for range finding which has a contrast and an aperture for general imaging which has high light transmittance are formed.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a liquid crystal panel, an imaging module, and an imaging device. [Background technology]

[0002] Distance measurement techniques are known that measure the distance from an imaging system to a subject by capturing an image of the subject and analyzing the captured image. Examples of imaging techniques used in such distance measurement techniques include coded imaging and stereo imaging.

[0003] The distance measurement technology using coded imaging is called DFD (Depth From Defocus). DFD is a technology that estimates the distance from the imaging device to the subject, i.e., the depth or perspective of the subject, based on the degree of blurring of edges in the image obtained by coded imaging.

[0004] DFD is described, for example, in Non-Patent Document 1. In DFD, coded imaging is performed in which a mask called a coded aperture is placed in the light entrance area of ​​an optical system to capture an image of a subject. Next, the captured image obtained by coded imaging is subjected to a decoding process based on a point spread function (PSF) specific to the imaging system including the mask, and the distance to the subject is estimated. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] "Coded Aperture Pairs for Depth from Defocus and Defocus Deblurring" C. Zhou, S. Lin and SK Nayar, International Journal of Computer Vision, Vol. 93, No. 1, pp. 53, May. 2011. Summary of the Invention [Problem to be solved by the invention]

[0006] Distance measurement techniques based on captured images have much room for improvement in terms of practicality. Under these circumstances, there is a demand for further improvements in the practicality of distance measurement techniques based on captured images. [Means for solving the problem]

[0007] Among the inventions disclosed in this application, the representative inventions will be outlined below.

[0008] A representative embodiment of the present invention includes a first liquid crystal cell and a second liquid crystal cell, the first liquid crystal cell and the second liquid crystal cell being disposed such that one cell surface of each cell is in contact with or faces each other and adjacent to each other, and the optical axes of each cell are parallel to or overlap each other, the first liquid crystal cell has a first guest-host liquid crystal in an incident light control region of the first liquid crystal cell, the alignment direction of which can be a first direction orthogonal to the optical axis direction of the first liquid crystal cell and the optical axis direction, and the alignment of the first guest-host liquid crystal in each region is controlled by an electric field in each region of the incident light control region of the first liquid crystal cell. and a second opening pattern that functions as an opening for imaging for non-distance measurement, wherein the second liquid crystal cell has, in an incident light control region of the second liquid crystal cell, a second guest-host liquid crystal that can take as its alignment direction a second direction that is perpendicular to the optical axis direction of the second liquid crystal cell and the first direction, and the optical axis direction, and the alignment direction of the second guest-host liquid crystal in each region is controlled by the electric field of each region in the incident light control region of the second liquid crystal cell, thereby forming the first opening pattern and the second opening pattern.

[0009] Another representative embodiment of the present invention includes an optical system, a liquid crystal panel, and an imaging element, the imaging element receiving light that has passed through the optical system and the liquid crystal panel, the liquid crystal panel including a first liquid crystal cell and a second liquid crystal cell, the first liquid crystal cell and the second liquid crystal cell being disposed such that one cell surface of each cell is in contact with or faces each other and that the optical axes of each cell are parallel to or overlap each other, the first liquid crystal cell having, in an incident light control region of the first liquid crystal cell, a first guest-host liquid crystal that can take, as its alignment direction, a first direction that is perpendicular to the optical axis direction of the first liquid crystal cell and the optical axis direction, The imaging system module is configured such that, under control of the electric field in each region, the orientation direction of the first guest-host liquid crystal in the respective regions changes to form a first aperture pattern that functions as an aperture for distance measurement imaging and a second aperture pattern that functions as an aperture for non-distance measurement imaging, and the second liquid crystal cell has, in an incident light control region of the second liquid crystal cell, a second guest-host liquid crystal whose orientation direction can be a second direction that is perpendicular to the optical axis direction of the second liquid crystal cell and the first direction, and the optical axis direction, and under control of the electric field in each region in the incident light control region of the second liquid crystal cell, the orientation direction of the second guest-host liquid crystal in the respective regions changes to form the first aperture pattern and the second aperture pattern.

[0010] Another representative embodiment of the present invention includes an optical system, a liquid crystal panel, an imaging element, and a control unit, wherein the imaging element receives light that has passed through the optical system and the liquid crystal panel, the liquid crystal panel including a first liquid crystal cell and a second liquid crystal cell, the first liquid crystal cell and the second liquid crystal cell being disposed such that one cell surface of each cell is in contact with or faces each other and that their optical axes are parallel to or overlap each other, the first liquid crystal cell has a first guest-host liquid crystal in an incident light control region of the first liquid crystal cell, the alignment direction of the first guest-host liquid crystal in each region being capable of taking a first direction orthogonal to the optical axis direction of the first liquid crystal cell and the optical axis direction, and the alignment direction of the first guest-host liquid crystal in each region is changed under the control of an electric field in each region in the incident light control region of the first liquid crystal cell, and a first aperture pattern functioning as an aperture for distance measurement imaging and a second aperture pattern functioning as an aperture for non-distance measurement imaging. and a second aperture pattern that functions as an aperture for imaging, wherein the second liquid crystal cell has a second guest-host liquid crystal that can take as its alignment direction a second direction perpendicular to the optical axis direction of the second liquid crystal cell and the first direction, and the optical axis direction in an incident light control region of the second liquid crystal cell, and the alignment direction of the second guest-host liquid crystal in each region is changed under control of an electric field in each region of the incident light control region of the second liquid crystal cell to form the first aperture pattern and the second aperture pattern, and the control unit controls the liquid crystal panel and the image sensor so that the first aperture pattern is formed in the first liquid crystal cell and the second liquid crystal cell and the imaging for distance measurement is performed, and controls the liquid crystal panel and the image sensor so that the second aperture pattern is formed in the first liquid crystal cell and the second liquid crystal cell and the imaging for non-distance measurement is performed. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing an example of installation of an imaging system according to a first embodiment. [Figure 2] FIG. 1 illustrates an example of the configuration of an imaging system. [Figure 3] FIG. 2 is a diagram illustrating an example of a configuration using functional blocks of an arithmetic control processing unit. [Figure 4] FIG. 2 is a diagram illustrating an example of the hardware configuration of an arithmetic control processing unit. [Figure 5] FIG. 2 is a side cross-sectional view of a liquid crystal panel. [Figure 6] FIG. 2 is a front view of the liquid crystal panel. [Figure 7] 1 is a side cross-sectional view of a first liquid crystal cell and a second liquid crystal cell. [Figure 8] FIG. 2 is a front view of a first liquid crystal cell and a second liquid crystal cell. [Figure 9] 3A and 3B are diagrams showing examples of the alignment directions of guest-host liquid crystals in a first liquid crystal cell and a second liquid crystal cell. [Figure 10] 3A and 3B are diagrams showing examples of the alignment directions of guest-host liquid crystals in a first liquid crystal cell and a second liquid crystal cell. [Figure 11] FIG. 10 is a diagram showing modes of a guest-host liquid crystal display. [Figure 12] FIG. 1 is a diagram for explaining the properties of a normally closed guest-host liquid crystal. [Figure 13] FIG. 10 is a diagram for explaining the properties of a normally open guest-host liquid crystal. [Figure 14] 10A and 10B are diagrams showing examples of contrast between a single cell and two overlapping cells of a guest-host liquid crystal. [Figure 15] 3A and 3B are diagrams showing examples of electrode structures in a first liquid crystal cell and a second liquid crystal cell. [Figure 16] FIG. 10 is a diagram illustrating a first modification of the first embodiment. [Figure 17] FIG. 2 is a diagram showing a first example of the structure of segment electrodes in a first liquid crystal cell and a second liquid crystal cell. [Figure 18] FIG. 10 is a diagram showing a second example of the structure of segment electrodes in the first liquid crystal cell and the second liquid crystal cell. [Figure 19] 10 is a diagram showing a third example of the structure of segment electrodes in the first liquid crystal cell and the second liquid crystal cell. FIG. [Figure 20] FIG. 10 is a diagram showing a fourth structural example of segment electrodes in the first liquid crystal cell and the second liquid crystal cell. [Figure 21] FIG. 10 is a diagram showing a fifth example of the structure of segment electrodes in the first liquid crystal cell and the second liquid crystal cell. [Figure 22] FIG. 10 is a diagram showing a sixth example of the structure of segment electrodes in the first liquid crystal cell and the second liquid crystal cell. [Figure 23] FIG. 10 is a diagram showing a seventh structural example of segment electrodes in the first liquid crystal cell and the second liquid crystal cell. [Figure 24] FIG. 10 is a diagram showing an eighth structural example of segment electrodes in the first liquid crystal cell and the second liquid crystal cell. DETAILED DESCRIPTION OF THE INVENTION

[0012] <Background of the study by the inventors> Before describing the embodiments of the present invention, the background to the investigations conducted by the present inventors will be described.

[0013] The present inventors have been studying an imaging device for subject distance measurement, in which a liquid crystal panel is placed in front of an optical system such as a lens, a geometric pattern is displayed on the liquid crystal panel, and the pattern functions as an aperture used for distance measurement imaging. As described above, distance measurement imaging is, for example, coded imaging or stereo imaging. On the other hand, when distance measurement imaging is not performed in such an imaging device, it is desirable that non-distance measurement imaging, i.e., general imaging, be possible. In general imaging, a circular aperture pattern centered on the optical axis of the liquid crystal panel is formed on the liquid crystal panel.

[0014] However, typical liquid crystal panels have polarizing plates. Polarizing plates have high light absorption, which reduces the light transmittance of the liquid crystal panel. This reduces the amount of light received by the imaging element, making it difficult to obtain bright, clear images. Liquid crystal panels that use guest-host liquid crystals are also known. Guest-host liquid crystal panels do not require polarizing plates, resulting in high light transmittance, but low light absorption in the light-blocking regions of the liquid crystal. Therefore, guest-host liquid crystal panels result in low contrast of the displayed geometric pattern, i.e., the aperture pattern, making them unsuitable for distance measurement imaging.

[0015] Due to the above circumstances, there is a demand for a liquid crystal panel that ensures contrast when forming an aperture pattern that functions as an aperture for distance measurement imaging, while having high light transmittance when forming an aperture pattern that functions as an aperture for non-distance measurement imaging, i.e., general imaging. In other words, there is a demand for a liquid crystal panel that can form an aperture pattern for distance measurement imaging with high contrast and an aperture pattern for non-distance measurement imaging with high light transmittance.

[0016] The present inventors have devised the present invention after extensive research in light of the above circumstances. The following describes an embodiment of the present invention. Note that the embodiment described below is merely an example for carrying out the present invention, and does not limit the technical scope of the present invention. In the following embodiments, components having the same functions are denoted by the same reference numerals, and repeated description thereof will be omitted unless particularly necessary.

[0017] (Embodiment 1) FIG. 1 is a diagram showing an example of installation of an imaging system 50 according to the first embodiment. As shown in FIG. 1, the imaging system 50 is installed in an automobile 100 serving as a vehicle. The imaging system 50 is configured to capture an image of a subject 90 in front of the automobile 100. As shown in FIG. 1, in this specification, the x direction is a direction parallel to the ground 60, the y direction is a vertical direction, and the z direction is a direction perpendicular to the x direction and the y direction. The z direction is the traveling direction of the forward side of the automobile 100. Note that the imaging system 50 may be configured to capture images of subjects in other directions, such as behind or to the side, in addition to the front.

[0018] <Configuration example of imaging system according to embodiment 1> Fig. 2 is a diagram showing an example of the configuration of an imaging system 50. As shown in Fig. 2, the imaging system 50 includes an imaging device 20 and an external device 30. The imaging device 20 and the external device 30 are electrically connected and are capable of communicating with each other. The external device 30 is, for example, a driving assistance device for a vehicle. The driving assistance device has, for example, a collision mitigation braking function, an all-speed adaptive cruise control function, a lane departure prevention function, a sudden acceleration prevention function, and the like.

[0019] The imaging device 20 has an imaging system module 5 and an arithmetic control processing unit 10. The imaging system module 5 has a liquid crystal panel 1, an optical system 2, and an imaging element 3. The imaging element 3 and the arithmetic control processing unit 10 are electrically connected, and the liquid crystal panel 1 and the arithmetic control processing unit 10 are electrically connected.

[0020] The optical system 2 focuses light incident from the subject 90 onto the light receiving surface 3a of the image sensor 3 to form an image. The optical system 2 includes, for example, a lens 2a. The lens 2a may be a single lens or a compound lens, and may be a fixed focal length lens or a zoom lens.

[0021] The light receiving surface 3a of the image sensor 3 is composed of a plurality of photoelectric conversion elements arranged two-dimensionally. The image sensor 3 converts light L received by the light receiving surface 3a after passing through the liquid crystal panel 1 and the optical system 2 into an electrical signal according to its intensity, and outputs image data based on the electrical signal to the arithmetic control processing unit 10. The image sensor 3 may also output the photoelectrically converted electrical signal to the arithmetic control processing unit 10, which may then obtain image data based on the electrical signal. The image sensor 3 is also called an image sensor. The image sensor 3 is, for example, a CMOS image sensor.

[0022] The liquid crystal panel 1 is disposed between the optical system 2 and the subject 90. However, the liquid crystal panel 1 may also be disposed between the optical system 2 and the image sensor 3. The liquid crystal panel 1 does not have a backlight. Under the control of the arithmetic control processing unit 10, the liquid crystal panel 1 controls the incident area of ​​light that enters the optical system 2 from the subject 90 and reaches the image sensor 3.

[0023] The liquid crystal panel 1 has an incident light control area. Here, the incident light control area has a perfect circular shape when viewed in the z direction and is composed of multiple regions. Each of these multiple regions is an area in which the alignment direction of the liquid crystal can be changed independently. The liquid crystal panel 1 sets each region in a light-absorbing state or a light-transmitting state by changing the alignment direction of the liquid crystal in each region of the incident light control area, thereby forming multiple types of geometric patterns. The light-absorbing state is also called a light-blocking state or a colored state, and the light-transmitting state is also called a light-transmitting state or a transparent state. By forming these geometric patterns, the liquid crystal panel 1 controls the incident area of ​​light L from the subject 90.

[0024] The liquid crystal panel 1 forms a first aperture pattern M1 and a second aperture pattern M2 as geometric patterns. The first aperture pattern M1 functions as an aperture used for imaging for distance measurement. The second aperture pattern M2 functions as an aperture (aperture for general imaging) used for imaging not for distance measurement (general imaging).

[0025] Here, coded imaging is assumed as imaging for distance measurement, and a coded aperture is assumed as the aperture for imaging for distance measurement in this case. The first aperture pattern M1 is usually a pattern representing an aperture having a shape different from a perfect circle centered on the optical axis of the liquid crystal panel 1. The first aperture pattern M1 includes, for example, aperture patterns M11 and M12 as shown in FIG. 2. The second aperture pattern M2 is, for example, a pattern representing an aperture having a perfect circle centered on the optical axis of the liquid crystal panel 1. The optical axis of the liquid crystal panel 1 is an axis that passes through the center or center of gravity of the incident light control area and is perpendicular to the panel surface.

[0026] The arithmetic control processing unit 10 controls the liquid crystal panel 1 and the image sensor 3 to perform coded imaging or general imaging. The arithmetic control processing unit 10 acquires image data P2 of the subject by general imaging. The arithmetic control processing unit 10 also calculates an estimated value of the depth from the imaging device 20 at each position of the subject 90 based on information obtained by decoding the image data P11 and P12 acquired by coded imaging. The arithmetic control processing unit 10 generates and outputs a depth map DM, for example, by associating each pixel of the image represented by the image data P2 with the estimated depth value corresponding to that pixel.

[0027] <Configuration example of the arithmetic and control processing unit> 3 is a diagram showing an example of the configuration of the arithmetic control processing unit using functional blocks. As shown in Fig. 3, the arithmetic control processing unit 10 has a control unit 1001, a storage unit 1002, and an arithmetic processing unit 1003. The arithmetic processing unit 1003 includes an image data processing unit 1005 and a depth map generation unit 1006.

[0028] The control unit 1001 transmits a control signal C1 to the liquid crystal panel 1 and also transmits a control signal C3 to the image sensor 3 to perform coded imaging and general imaging of the subject 90. The control unit 1001 causes the storage unit 1002 to read, from the image sensor 3, image data P11 obtained by coded imaging using the aperture pattern M11 as the coded aperture and image data P12 obtained by coded imaging using the aperture pattern M12 as the coded aperture. The control unit 1001 also causes the storage unit 1002 to read, from the image sensor 3, image data P2 obtained by general imaging using the second aperture pattern M2 as the aperture for general imaging. Note that here, the image data P11 and image data P12 obtained adjacently in terms of time are referred to as one frame of captured image data F.

[0029] The control unit 1001 sends a control signal C1 to the liquid crystal panel 1 and a control signal C3 to the image sensor 3 so that one frame's worth of captured image data F and image data P2 can be repeatedly read multiple times. For example, the control unit 1001 controls the liquid crystal panel 1 and the image sensor 3 so that a series of operations are performed: forming an aperture pattern M11 on the liquid crystal panel 1, exposing the light receiving surface 3a of the image sensor 3 to light L from the subject 90, reading the image data P11, forming an aperture pattern M12 on the liquid crystal panel 1, exposing the light receiving surface 3a of the image sensor 3 to light L from the subject 90, and reading the image data P12. The control unit 1001 also controls the liquid crystal panel 1 and the image sensor 3 so that a second aperture pattern M2 is formed on the liquid crystal panel 1, exposing the light receiving surface 3a of the image sensor 3 to light L from the subject 90, and reading the image data P2. The control unit 1001 repeatedly executes these controls.

[0030] Each time one frame of captured image data F is read into the storage unit 1002, i.e., each time one frame of encoded imaging is performed, the image data processing unit 1005 performs image data processing including decoding using the point spread function of the imaging system, based on the captured image data F. In the first embodiment, the image data processing unit 1005 obtains an estimate of the depth, i.e., the depth dr, at each position of the object 90 corresponding to each pixel of the object image J1 represented by the image data P2 through decoding processing of the captured image data F. The depth at each position refers to the distance from the imaging system to each position of the object 90.

[0031] The depth map generation unit 1006 generates a depth map DM of the subject 90 based on the subject image J1 and the depth dr at each position of the subject 90. The depth map DM is a map of the depth at each position of the subject 90. The calculation processing unit 1003 sends the generated depth map DM to the external device 30.

[0032] Fig. 4 is a diagram showing an example of the hardware configuration of the arithmetic control processing unit. As shown in Fig. 4, the arithmetic control processing unit 10 has a processor 1101, a memory 1102, a storage 1103, an interface 1104, and a communication bus 1105. The processor 1101, the memory 1102, the storage 1103, and the interface 1104 are connected to the communication bus 1105. The processor 1101 is, for example, a central processing unit (CPU), a microprocessor (MPU), or a microcontroller (MCU). The memory 1102 is, for example, a semiconductor memory such as RAM, ROM, or EEPROM. The storage 1103 is, for example, a storage device such as a hard disk drive (HDD) or a solid state drive (SSD). The interface 1104 is a connection part with an external device and performs input and output of data to and from the external device.

[0033] A program PG is stored in the memory 1102 or the storage 1103. The processor 1101 reads out this program PG, loads it into the memory 1102, and executes it, thereby functioning as various functional blocks in cooperation with other devices. In the first embodiment, the processor 1101 functions as each functional block from the control unit 1001 to the depth map generation unit 1006. Note that the storage 1103 may be omitted, and the program PG may be stored in the memory 1102. Also, some or all of the components from the processor 1101 to the interface 1104 may be an integrated circuit formed integrally, i.e., chip-shaped.

[0034] <Example of LCD panel configuration> Fig. 5 is a side cross-sectional view of the liquid crystal panel, and Fig. 6 is a front view of the liquid crystal panel. As shown in Fig. 5, the liquid crystal panel 1 includes a first liquid crystal cell 11 and a second liquid crystal cell 12.

[0035] The first liquid crystal cell 11 and the second liquid crystal cell 12 are arranged so that one cell surface 11K, 12K of each cell is in contact with or close to each other and faces each other. The first liquid crystal cell 11 and the second liquid crystal cell 12 are also arranged so that their optical axes, i.e., the optical axis Z1 of the first liquid crystal cell 11 and the optical axis Z2 of the second liquid crystal cell 12, are parallel to or overlap each other. The optical axis Z1 and the optical axis Z2 typically pass through the center or center of gravity of the incident light control region of the liquid crystal cell and are perpendicular to the cell surface. The optical axis LZ of the liquid crystal panel 1 is parallel to or overlaps the optical axis Z1 and the optical axis Z2. In the first embodiment, the optical axis Z1 and the optical axis Z2 overlap. The optical axis LZ of the liquid crystal panel 1 also overlaps the optical axis Z1 and the optical axis Z2 and is parallel to the z direction.

[0036] As shown in Fig. 5, the incident light control region R has a cylindrical shape with its central axis coincident with the optical axis LZ of the liquid crystal panel 1. Furthermore, as shown in Fig. 6, the incident light control region R has a perfect circular shape when viewed along the z direction. As shown in Figs. 5 and 6, the first liquid crystal cell 11 and the second liquid crystal cell 12 each have a substantially rectangular shape and have substantially the same configuration.

[0037] Fig. 7 is a side cross-sectional view of the first liquid crystal cell 11 and the second liquid crystal cell 12. Fig. 8 is a front view of the first liquid crystal cell 11 and the second liquid crystal cell 12.

[0038] 7, the first liquid crystal cell 11 includes an array substrate 111, a counter substrate 112, an electrode driving circuit 113, an array substrate-side electrode 114, an array substrate-side alignment film 115, a counter substrate-side electrode 116, a light-shielding member 117, a counter substrate-side alignment film 118, a spacer 119, a sealant 11S, a first guest-host liquid crystal 11A, and a flexible substrate 11F.

[0039] The array substrate 111 and the counter substrate 112 are arranged so that one of the substrate surfaces faces each other.

[0040] The electrode driving circuit 113 is disposed on the substrate surface of the array substrate 111. The array substrate-side electrodes 114 are disposed in a region of the electrode driving circuit 113 that corresponds to the incident light control region R or in a region that includes this region. The array substrate-side alignment film 115 is disposed so as to cover the array substrate-side electrodes 114 and the electrode driving circuit 113.

[0041] The counter substrate side electrode 116 is disposed on the counter substrate 112. The light shielding member 117 is disposed so as to cover the outside of the region of the counter substrate 112 and the counter substrate side electrode 116 that corresponds to the incident light control region R. The counter substrate side alignment film 118 is disposed so as to cover the counter substrate side electrode 116 and the light shielding member 117.

[0042] A plurality of spacers 119 are provided between the array substrate side alignment film 115 and the counter substrate side alignment film 118, and a first guest-host liquid crystal 11A is disposed between them. A sealant 11S is disposed between the array substrate side alignment film 115 and the counter substrate side alignment film 118 so as to seal the first guest-host liquid crystal 11A.

[0043] A flexible substrate 11F is disposed on the array substrate 111. The flexible substrate 11F is electrically connected to the array substrate side electrodes 114 and the counter substrate side electrodes 116 via wiring. The flexible substrate 11F is electrically connected to the control unit 1001 via wiring. Note that the wiring is not shown in FIGS. 7 and 8.

[0044] The array substrate 111 and the counter substrate 112 are optically transparent and are, for example, glass substrates. The array substrate-side electrode 114 and the counter substrate-side electrode 116 are optically transparent and are so-called transparent electrodes. The first guest-host liquid crystal 11A is composed of dye molecules 11G and liquid crystal molecules 11H. The dye molecules 11G correspond to the guest and are also called dichroic dyes. The liquid crystal molecules 11H correspond to the host and are simply called liquid crystals. The dye molecules 11G have a short axis direction and a long axis direction, and their light absorption varies depending on the axis direction, i.e., the orientation direction. In other words, the dye molecules 11G are anisotropic. The dye molecules 11G are oriented in accordance with the movement of the liquid crystal molecules 11H, creating a light-absorbing state and a light-transmitting state.

[0045] Similar to the first liquid crystal cell 11, the second liquid crystal cell 12 includes an array substrate 121, a counter substrate 122, an electrode driving circuit 123, an array substrate-side electrode 124, an array substrate-side alignment film 125, a counter substrate-side electrode 126, a light-shielding member 127, a counter substrate-side alignment film 128, a spacer 129, a sealant 12S, a second guest-host liquid crystal 12A, and a flexible substrate 12F. The second guest-host liquid crystal 12A is composed of dye molecules 12G and liquid crystal molecules 12H. The arrangement and configuration of these elements of the second liquid crystal cell 12 are similar to those of the first liquid crystal cell 11, and therefore will not be described here.

[0046] 9 and 10 are diagrams showing examples of the alignment directions of the guest-host liquid crystal in the first and second liquid crystal cells. Fig. 9 is a side cross-sectional view of the first and second liquid crystal cells 11 and 12. Fig. 10 is a front view of the first and second liquid crystal cells 11 and 12.

[0047] 9 and 10, the first guest-host liquid crystal 11A in the first liquid crystal cell 11 is configured to have two alignment directions: a first alignment direction H1 (first direction) perpendicular to the optical axis direction parallel to the optical axis Z1 of the first liquid crystal cell 11, and the optical axis direction. The second guest-host liquid crystal 12A in the second liquid crystal cell 12 is configured to have two alignment directions: a second alignment direction H2 (second direction) perpendicular to the optical axis direction parallel to the optical axis Z2 of the second liquid crystal cell 12, and the optical axis direction. The first alignment direction H1 and the second alignment direction H2 are perpendicular to each other.

[0048] In the first embodiment, the first alignment direction H1 is the x-direction, and the second alignment direction H2 is the y-direction. The optical axis direction parallel to the optical axis Z1 and the optical axis direction parallel to the optical axis Z2 are parallel to the optical axis LZ of the liquid crystal panel 1, which is the z-direction.

[0049] <Guest Host LCD Mode> FIG. 11 is a diagram showing modes of a guest-host liquid crystal. As shown in FIG. 11, guest-host liquid crystal modes include a normally closed mode and a normally open mode. In the normally closed mode, the driving mode is an ECB (Electrically Controlled Birefringence) mode, which is absorptive (colored) when the voltage (electric field) is off and transparent when the voltage is on, the liquid crystal is a positive liquid crystal, the alignment direction is horizontal to the liquid crystal cell surface, and the response time is several tens of milliseconds. On the other hand, in the normally open mode, the driving mode is a VA (Vertical Aligned) mode, which is transparent when the voltage is off and absorptive (colored) when the voltage is on, the liquid crystal is a negative liquid crystal, the alignment direction is perpendicular to the liquid crystal cell surface, and the response time is several tens of milliseconds.

[0050] Figure 12 illustrates the properties of a normally-closed guest-host liquid crystal. This normally-closed guest-host liquid crystal is driven in ECB mode. As shown in Figure 12, the normally-closed guest-host liquid crystal contains positive liquid crystal 41H as the host and dye molecules 41G as the guest. Here, the direction perpendicular to the liquid crystal cell surface is designated as direction Z3. A horizontal alignment film is used to align the liquid crystal parallel to the liquid crystal cell surface. When the guest-host liquid crystal is viewed from viewpoint 40E along direction Z3, when the voltage is off, the side NC1 of the dye molecules 41G along the long axis is visible, and the guest-host liquid crystal appears colored. On the other hand, when the voltage is on, i.e., when an electric field EV is generated along direction Z3, the side NC2 of the dye molecules 41G along the short axis is visible, and the guest-host liquid crystal appears transparent.

[0051] FIG. 13 is a diagram illustrating the properties of a normally open guest-host liquid crystal. A normally open guest-host liquid crystal is driven in VA mode. As shown in FIG. 13, a normally open guest-host liquid crystal contains negative liquid crystal 42H as a host and dye molecules 42G as a guest. Here, the direction perpendicular to the liquid crystal cell surface is defined as direction Z3. A vertical alignment film that aligns the liquid crystal in a direction perpendicular to the liquid crystal cell surface is used as the alignment film.

[0052] When the guest-host liquid crystal is viewed from viewpoint 40E along direction Z3, when the voltage is off, side NO1 of dye molecule 42G in the minor axis direction is visible, and the guest-host liquid crystal appears transparent. On the other hand, when the voltage is on, that is, when an electric field EV is generated along direction Z3, side NO2 of dye molecule 42G in the major axis direction is visible, and the guest-host liquid crystal appears colored. Dye molecules 42G are typically colored black, but they can also be colored in colors other than black.

[0053] In the first embodiment, the guest-host liquid crystals in the first and second liquid crystal cells 11 and 12 are in the same mode. Furthermore, the mode is a normally open (VA) mode. Specifically, the first guest-host liquid crystal 11A is oriented in a first alignment direction H1 in a space where an electric field is applied, and is oriented in the z direction in a space where an electric field is not applied in the z direction. The second guest-host liquid crystal 12A is oriented in a second alignment direction H2 in a space where an electric field is applied, and is oriented in the z direction in a space where an electric field is not applied in the z direction.

[0054] In the first embodiment, as described above, the first liquid crystal cell 11 and the second liquid crystal cell 12 constituting the liquid crystal panel 1 have the same configuration, but the orientation directions of the guest-host liquid crystal in the electric field generation space are orthogonal to each other. That is, the liquid crystal panel 1 according to the first embodiment is configured by stacking two guest-host liquid crystal cells, each with a liquid crystal alignment treatment angle of 90° apart, so that the polarization axes are orthogonal to each other. In this configuration, the flexible substrate 11F of the first liquid crystal cell 11 and the flexible substrate 12F of the second liquid crystal cell 12 are located on the same side. As a result, it is easier to organize the wiring connecting the flexible substrates 11F and 12F to the arithmetic control processing unit 10, facilitating the design of the imaging device 20.

[0055] With a normally open liquid crystal shutter (liquid crystal panel), no voltage is applied when capturing an image that does not contain distance information, and the liquid crystal shutter is only driven when capturing an image that does contain distance information, thereby reducing power consumption.

[0056] <Comparison of contrast between a single cell and two stacked cells of guest-host liquid crystal> Figure 14 shows examples of contrast when a guest-host liquid crystal is used in a single cell and when two cells are stacked. A single cell is when there is one liquid crystal cell with a predetermined gap thickness between the array substrate and the counter substrate. A double cell is when two liquid crystal cells with the predetermined gap thickness are stacked so that their polarization axes are perpendicular to each other.

[0057] The contrast can be obtained, for example, as follows: First, a predetermined geometric pattern is formed in the incident light control region by controlling the electric field generated in the liquid crystal cell space and controlling the alignment direction of each region of the guest-host liquid crystal. Next, the maximum light transmittance Tmax and the minimum light transmittance Tmin of the formed pattern are measured, and the value obtained by dividing Tmax by Tmin is the contrast.

[0058] In one experimental example, the contrast ratio for a single cell was 2.0, while the contrast ratio for two stacked cells was 30.1, as shown in Figure 14. In this way, stacking two guest-host liquid crystal cells so that their polarization axes are perpendicular can significantly improve the contrast of the pattern formed on the liquid crystal panel.

[0059] <Liquid crystal cell electrode structure> FIG. 15 is a diagram showing an example of the electrode structure in the first liquid crystal cell and the second liquid crystal cell. The first and second liquid crystal cells 11 and 12 according to the first embodiment have a so-called vertical electric field structure that generates an electric field in the z direction. Here, the geometric pattern formation method, i.e., the display method, in the first and second liquid crystal cells 11 and 12 is assumed to be a matrix method. The matrix method uses, for example, an electrode structure 453 in which a plurality of signal electrodes 453S and a plurality of scanning electrodes 453C are arranged so as to intersect with each other, as shown in the left diagram of FIG. 15. The plurality of signal electrodes 453S are an electrode group in which a plurality of electrodes extending elongated in the y direction are arranged in the x direction. The plurality of scanning electrodes 453C are an electrode group in which a plurality of electrodes extending elongated in the x direction are arranged in the y direction.

[0060] The area where the signal electrode 453S and the scanning electrode 453C intersect forms a pixel area. When the voltage applied to the signal electrode 453S and the scanning electrode 453C is controlled to generate an electric field in the target pixel area, the liquid crystal in the electric field is oriented and becomes light-absorbing or light-transmitting.

[0061] To realize the matrix display method, for example, a simple matrix structure 45A as shown in the upper right diagram of FIG. 15 or an active matrix structure 45B as shown in the lower right diagram of FIG. 15 is used. In the simple matrix structure 45A, two glass substrates 451 and 452 are arranged opposite each other, and strip electrodes 453H are provided on one side and strip electrodes 453V are provided on the other side. The strip electrodes 453H and 453V are arranged to intersect, and liquid crystal is sandwiched between the strip electrodes 453H and 453V. Pixels are formed in the intersections between the strip electrodes 453H and 453V.

[0062] In the active matrix structure 45B, two glass substrates 451, 452 are arranged opposite each other, and scanning lines 454H and data lines 454V are provided on one side, and plate electrodes 455 are provided on the other side. The scanning lines 454H and the data lines 454V are arranged so as to intersect. Active elements such as transistors are provided at the intersections of the scanning lines 454H and the data lines 454V, and the active elements are connected to transparent electrodes 456 corresponding to the pixels. When an ON signal is input to the scanning line 454H and the data line 454V, a potential is generated in the corresponding transparent electrode 456, and an electric field is generated between the plate electrode 455 and the transparent electrode 456.

[0063] <Operation of the control unit on the liquid crystal cell> When the first and second liquid crystal cells 11 and 12 have a simple matrix electrode structure, the control unit 1001 controls the voltage applied to each electrode to control the electric field in each pixel region, thereby forming any geometric pattern in the first and second liquid crystal cells 11 and 12. When the first and second liquid crystal cells 11 and 12 have an active matrix electrode structure, the control unit 1001 controls the signals input to each scan line and each data line to control the electric field in each pixel region, thereby forming any geometric pattern in the first and second liquid crystal cells 11 and 12. Through such control by the control unit 1001, any aperture pattern can be formed in the liquid crystal panel 1.

[0064] As described above, according to the first embodiment, the liquid crystal panel 1 has a structure in which two liquid crystal cells are stacked together, each labeled so that the orientation directions of the guest-host liquid crystal are perpendicular to each other, i.e., at an angle of 90° from each other. A liquid crystal cell using a guest-host liquid crystal does not require a polarizing plate. Furthermore, the guest-host liquid crystal contains dye molecules, and when the guest-host liquid crystal is aligned in the labeled orientation direction, it functions similarly to a polarizing plate. Therefore, when the guest-host liquid crystals of the two liquid crystal cells are in a colored state, the light transmittance is significantly reduced, whereas when the guest-host liquid crystals of the two liquid crystal cells are in a transparent state, the light transmittance is improved.

[0065] Therefore, according to embodiment 1, in an imaging liquid crystal panel that controls the light incidence area, it is possible to improve the light transmittance of the aperture for non-ranging imaging, i.e., general imaging, while ensuring the contrast of the aperture for ranging imaging.

[0066] In the first embodiment, the first liquid crystal cell 11 and the second liquid crystal cell 12 have the same structure except for the labeled alignment direction of the guest-host liquid crystal, and are disposed on top of each other without changing the orientation of the liquid crystal cell bodies. Therefore, the electric field control of each pixel region arranged in a matrix in the incident light control region can be performed in the same way for the first liquid crystal cell 11 and the second liquid crystal cell 12. This facilitates control of the first liquid crystal cell 11 and the second liquid crystal cell 12 when forming an aperture pattern. In addition, in this case, the flexible substrates 11F and 12F are located on the same side, which makes it easier to organize the wiring connected to the flexible substrates 11F and 12F.

[0067] <Variation 1> FIG. 16 is a diagram illustrating Modification 1 of Embodiment 1. In Modification 1, the first liquid crystal cell 11 and the second liquid crystal cell 12 have similar structures, including the labeled alignment direction of the guest-host liquid crystal. As shown in FIG. 16, the first liquid crystal cell 11 is a liquid crystal cell according to a first specification in which the first alignment direction H1 of the guest-host liquid crystal is labeled in a specific direction (here, vertical) relative to the liquid crystal cell body. The second liquid crystal cell 12 is a liquid crystal cell according to a first specification in which the second alignment direction H2 of the guest-host liquid crystal is labeled in the above-mentioned specific direction relative to the liquid crystal cell body, rotated 90° around the optical axis direction of the first liquid crystal cell 11 relative to the first liquid crystal cell 11. Here, the first liquid crystal cell 11 and the second liquid crystal cell 12 are arranged so that the optical axis Z1 of the first liquid crystal cell 11 and the optical axis Z2 of the second liquid crystal cell 12 overlap, i.e., so that the incident light control region R1 and the incident light control region R2 overlap.

[0068] According to Modification 1, two liquid crystal cells having the same specifications are rotated by 90 degrees and stacked together to form the liquid crystal panel 1. This reduces the manufacturing cost of the liquid crystal cells.

[0069] <Variation 2> In the first embodiment, stereo imaging may be performed instead of coded imaging for distance measurement. In this modification, the first aperture pattern M1 formed on the liquid crystal panel 1, i.e., aperture patterns M11 and M12, function as two types of apertures used in stereo imaging. The two types of apertures used in stereo imaging have apertures with different opening positions relative to the image sensor 3. The image data processing unit 1005 performs image processing on the captured image data F using triangulation to obtain a blur-free object image J1 representing the object 90 and depths dr at each position of the object 90 corresponding to each pixel of the object image J1.

[0070] In this variant example 2, similar to the effect of embodiment 1, in an imaging liquid crystal panel that controls the light incidence area, the contrast of the aperture for ranging imaging can be ensured while the light transmittance of the aperture for non-ranging imaging, i.e., general imaging, can be improved.

[0071] <Variation 3> In the first embodiment, the incident light control region containing the guest-host liquid crystal is composed of a plurality of pixel regions arranged in a matrix, but the incident light control region may be composed of a plurality of segment regions. That is, in the first embodiment, the pattern formation method is a matrix method and the electrode structure of the liquid crystal cell is a matrix structure, but the pattern formation method may be a segment method and the electrode structure of the liquid crystal cell may be a segment structure. In a segment structure, generally, one of the electrodes on the array substrate side and the electrode on the counter substrate side is composed of a flat electrode, and the other is composed of a plurality of segment electrodes.

[0072] The plurality of segment electrodes in the first liquid crystal cell and the plurality of segment electrodes in the second liquid crystal cell are configured so that, when the two liquid crystal cells are stacked, the segment electrodes that correspond to each other in the z direction have the same shape and size.

[0073] 17 is a diagram showing a first structural example of segment electrodes in a first liquid crystal cell and a second liquid crystal cell. As shown in FIG. 17, the segment electrode structure PCA according to the first structural example has a structure in which multiple segment electrodes TA1, TA2, TA3, and TA4 are arranged inside an annular light-shielding member BM1. By making only the regions (of the guest-host liquid crystal) corresponding to the segment electrodes TA1 and TA2 light-absorbing, or by making only the regions corresponding to the segment electrodes TA1 and TA3 light-absorbing, an aperture pattern for coded imaging, i.e., a coded aperture, can be formed. On the other hand, by making the regions corresponding to the segment electrodes TA1 to TA4 light-transmitting, an aperture pattern for general imaging, i.e., an aperture stop, can be formed.

[0074] Fig. 18 is a diagram showing a second structural example of segment electrodes in a first liquid crystal cell and a second liquid crystal cell. As shown in Fig. 18, the segment electrode structure PCA according to the second structural example has segment electrodes TA1 to TA6. For example, the segment electrode TA1 has a circular ring shape, the segment electrode TA2 has a ring shape surrounded by the segment electrode TA1, and the segment electrode TA3 has a circular shape surrounded by the segment electrode TA2. The segment electrodes TA4 to TA6 each have a ring shape.

[0075] Segment electrode TA1, segment electrode TA2, and segment electrodes TA4 to TA6 each include a plurality of segmented electrodes divided into a plurality of parts in the circumferential direction. Segment electrode TA1 includes a plurality of segmented electrodes VI1, segment electrode TA2 includes a plurality of segmented electrodes VI2, segment electrode TA4 includes a plurality of segmented electrodes VI4, segment electrode TA5 includes a plurality of segmented electrodes VI5, and segment electrode TA6 includes a plurality of segmented electrodes VI6.

[0076] In structural example 2, the segmented electrodes TA1, TA2, and TA4 to TA6 are each divided into four equal parts. In this example, the segmented electrodes TA1, TA2, and TA4 to TA6 are each divided into four equal parts. The boundaries of the segmented electrodes VI1, VI2, VI4, VI5, and VI6 are aligned in the radial direction of the circle formed by the inner edge of the light-shielding member BM1. The multiple segmented electrodes VI1 to VI6 (excluding VI3) are electrically independent from each other.

[0077] The segment electrode TA3 can be used as a pinhole region. No light-shielding layer is provided between adjacent segment electrodes TAn (n=1, 2, . . . , 6) in the radial direction. The segment electrodes TA1 to TA6 are positioned in a concentric multiple circle shape. This allows the liquid crystal panel 1 to open and close the aperture.

[0078] Here, we focus on the segment electrodes TA1 and TA2. The liquid crystal panel 1 can set the entire segment electrode TA2 to a light-transmitting or light-absorbing state during the period when the entire segment electrode TA1 is set to a light-absorbing state. Furthermore, the liquid crystal panel 1 can set the entire segment electrode TA2 to a light-transmitting state during the period when the entire segment electrode TA1 is set to a light-transmitting state.

[0079] Furthermore, by setting at least one of the segment electrodes TA1 and TA2 of the liquid crystal panel 1 to a light-transmitting state, the image sensor 3 can acquire information about visible light that has passed through the liquid crystal panel 1 and is directed from the subject 90. This allows the image sensor 3 to capture an image of the subject 90. The control unit 1001 can acquire not only distance information about the subject 90 (information about the distance from the imaging device 20 to the subject 90) but also image information about the subject 90 from the image sensor 3.

[0080] 19 is a diagram showing a third structural example of the segment electrodes in the first liquid crystal cell and the second liquid crystal cell. As shown in FIG. 19, the segment electrode structure PCA according to the third structural example has an annular segment electrode T2 disposed inside an annular light-shielding member BM1, and a circular segment electrode T1 disposed inside the segment electrode T2. By placing the region corresponding to the segment electrode T2 in a light-absorbing state and the region corresponding to the segment electrode T1 in a light-transmitting state, an aperture with a small light-transmitting region can be formed. By placing the regions corresponding to the segment electrodes T2 and T1 in a light-transmitting state, an aperture with a large light-transmitting region can be formed.

[0081] FIG. 20 is a diagram showing a fourth structural example of the segment electrodes in the first liquid crystal cell and the second liquid crystal cell. As shown in FIG. 20, the segment electrode structure PCA according to the fourth structural example has a wide annular segment electrode T2 disposed inside an annular light-shielding member BM1, and a pinhole-shaped segment electrode T1 disposed inside the segment electrode T2. By placing the region corresponding to the segment electrode T2 in a light-absorbing state and the region corresponding to the segment electrode T1 in a light-transmitting state, a pinhole-shaped aperture with a very small light-transmitting region can be formed. By placing the regions corresponding to the segment electrodes T2 and T1 in a light-transmitting state, an aperture with a large light-transmitting region can be formed.

[0082] Fig. 21 is a diagram showing a fifth structural example of segment electrodes in the first liquid crystal cell and the second liquid crystal cell. As shown in Fig. 21, the segment electrode structure PCA according to the fifth structural example has a structure in which a circular segment electrode T2 is arranged inside an annular light-shielding member BM1, covering the entire area inside the annular light-shielding member BM1. The shutter can be opened by placing the area corresponding to the segment electrode T2 in a light-transmitting state, and can be closed by placing the area corresponding to the segment electrode T2 in a light-absorbing state.

[0083] FIG. 22 is a diagram showing a sixth structural example of segment electrodes in the first and second liquid crystal cells. As shown in FIG. 22, the sixth structural example of segment electrodes PCA has a structure in which segment electrodes T1 and T2 are arranged inside an annular light-shielding member BM1. The segment electrode T2 is a circular electrode whose center is shifted from the center CN of the incident light control area. The segment electrode T1 corresponds to the entire inner area of ​​the light-shielding member BM1 excluding the area of ​​the segment electrode T2. By making the area corresponding to the segment electrode T2 a light-absorbing state, a coded aperture can be formed. Furthermore, by making the areas corresponding to the segment electrodes T1 and T2 a light-transmitting state, an aperture for general imaging can be formed.

[0084] Fig. 23 is a diagram showing Structural Example 7 of the segment electrodes in the first liquid crystal cell and the second liquid crystal cell. As shown in Fig. 23, the segment electrode structure PCA according to Structural Example 7 is similar to Structural Example 6, and the center of the segment electrode T2 is located at a different position from that in Structural Example 6. In the case of Structural Example 7, as in Structural Example 6, a coded aperture and an aperture stop for general imaging can be formed.

[0085] FIG. 24 is a diagram showing an eighth structural example of segment electrodes in a first liquid crystal cell and a second liquid crystal cell. As shown in FIG. 24, in the segment electrode structure PCA according to the eighth structural example, segment electrodes T1, T2, and T3 are arranged inside an annular light-shielding member BM1. The segment electrodes T1 and T2 have the shape of circles (perfect circles) of the same size. The diameter of each of the segment electrodes T1 and T2 is half the inner diameter of the light-shielding member BM1. The segment electrodes T1 and T2 are arranged side by side in the x direction and are in contact with each other. The segment electrode T3 has a shape corresponding to the entire inner area of ​​the light-shielding member BM1 excluding the areas of the segment electrodes T1 and T2.

[0086] Of the segment electrodes T1 to T3, by making only the region corresponding to segment electrode T1 light-transmitting or by making only the region corresponding to segment electrode T2 light-transmitting, a coded aperture or an aperture for stereo imaging can be formed. Also, by making the regions corresponding to segment electrodes T1 to T3 light-transmitting, an aperture for general imaging can be formed.

[0087] In this way, it is possible to form apertures corresponding to desired coded imaging, desired stereo imaging, or desired general imaging by configuring the segment electrodes of the first liquid crystal cell 11 and the second liquid crystal cell 12 to have a desired structure. Furthermore, by adopting a segment electrode structure, the area to be controlled can be reduced compared to a matrix electrode structure, making it easier to control the voltage applied to the electrodes.

[0088] (Other embodiments) The imaging system according to the first embodiment has been described above, but an imaging method that follows the processing flow in the imaging system 50 is also an embodiment of the present invention.

[0089] Furthermore, a program for causing a processor to function as control unit 1001 in the first embodiment, and a tangible storage medium for non-temporarily storing the program are also embodiments of the present invention.

[0090] Although various embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and various modifications are possible. Furthermore, the numerical values ​​and the like contained in the text and figures are merely examples, and the effects of the present invention will not be impaired even if different values ​​are used.

[0091] For example, in the above embodiment, the imaging system 50 is installed in an automobile, but the imaging system 50 may be installed in a vehicle or mobile device other than an automobile. For example, the imaging system 50 may be installed in a vehicle or device that moves on land, in the air, on the sea, or underwater. More specifically, the imaging system 50 may be installed in, for example, a railway or monorail train, a motorcycle, a bicycle, a ship, a submarine, an airplane, a drone, various unmanned survey vehicles, unmanned transport vehicles, etc. Even in such an installation example, the imaging system 50 can achieve the same effects as in the above embodiment and can be used, for example, in driving assistance technology. Furthermore, the imaging system 50 may be used independently without being mounted on a vehicle or mobile device. [Explanation of symbols]

[0092] 1...liquid crystal panel, 2...optical system, 2a...lens, 3...imaging element, 3a...light receiving surface, 5...imaging system module, 10...arithmetic control processing unit, 11...first liquid crystal cell, 11S, 12S...sealing material, 11A...first guest-host liquid crystal, 12A...second guest-host liquid crystal, 11H, 12H...liquid crystal molecules, 11G, 12G, 41G, 42G...dye molecules, 11F, 12F...flexible substrate, 12...second liquid crystal cell, 20...imaging device, 30...external device, 40E...viewpoint, 41H...positive liquid crystal, 42H...negative liquid crystal, 45A...simple matrix structure, 45B ...active matrix structure, 50...imaging system, 60...ground, 90...object, 100...automobile, 111,121...array substrate, 112,122...counter substrate, 113,123...electrode driving circuit, 114,124...array substrate side electrode, 115,125...array substrate side alignment film, 116,126...counter substrate side electrode, 117,127...light shielding member, 118,128...counter substrate side alignment film, 119,129...spacer, 451,452...glass substrate, 453...electrode structure, 453C...scanning electrode, 453H,453V...strip electrode, 453 S...signal electrode, 454H...scanning line, 454V...data line, 455...plate electrode, 456...transparent electrode, 1001...control unit, 1002...storage unit, 1003...arithmetic processing unit, 1005...image data processing unit, 1006...depth map generation unit, 1101...processor, 1102...memory, 1103...storage, 1104...interface, 1105...communication bus, BM1...light shielding member, C1, C3...control signal, DM...depth map, dr...depth, EV...electric field, F...captured image data, H1...first alignment direction, H2...second alignment direction, J1 ...Subject image, L...light, M1...first aperture pattern, M11, M12...aperture pattern, M2...second aperture pattern, NC1, NO2...side surface of dye molecule in the long axis direction, NC2, NO1...side surface of dye molecule in the short axis direction, P11, P12, P2...image data, PCA...structure of segment electrode, PG...program, R, R1, R2...incident light control area, T1, T2, T3, TA1, TA2, TA3, TA4, TA5, TA6...segment electrode, VI1, VI2, VI4, VI5, VI6...segment electrode, Z1, Z2, LZ...optical axis

Claims

1. a first liquid crystal cell and a second liquid crystal cell; the first liquid crystal cell and the second liquid crystal cell are arranged so that one cell surface of each cell is in contact with or faces each other and is close to each other, and the optical axes of each cell are parallel to or overlap each other; The first liquid crystal cell In the incident light control region of the first liquid crystal cell, a first guest-host liquid crystal having an alignment direction that can be a first direction perpendicular to the optical axis direction of the first liquid crystal cell and the optical axis direction; an orientation direction of the first guest-host liquid crystal in each region is changed under control of an electric field in each region in the incident light control region of the first liquid crystal cell, thereby forming a first opening pattern that functions as an aperture for imaging for distance measurement and a second opening pattern that functions as an aperture for imaging for non-distance measurement; The second liquid crystal cell comprises: In the incident light control region of the second liquid crystal cell, a second guest-host liquid crystal having an alignment direction that can be a second direction perpendicular to the optical axis direction of the second liquid crystal cell and the first direction, and the optical axis direction; an alignment direction of the second guest-host liquid crystal in each region of the incident light control region of the second liquid crystal cell is changed under control of an electric field in each region, thereby forming the first opening pattern and the second opening pattern; LCD panel.

2. 2. The liquid crystal panel according to claim 1, the mode of the first guest-host liquid crystal is normally closed or normally open; The mode of the second guest-host liquid crystal is normally closed or normally open. LCD panel.

3. 3. The liquid crystal panel according to claim 2, The mode of the first guest-host liquid crystal and the mode of the second guest-host liquid crystal are the same. LCD panel.

4. 2. The liquid crystal panel according to claim 1, a pattern formation method in the incident light control region of the first liquid crystal cell and the second liquid crystal cell is a matrix method; LCD panel.

5. 2. The liquid crystal panel according to claim 1, a pattern formation method in the incident light control region of the first liquid crystal cell and the second liquid crystal cell is a segment method; LCD panel.

6. 2. The liquid crystal panel according to claim 1, the first liquid crystal cell is a liquid crystal cell according to a first specification in which the alignment direction of the guest-host liquid crystal is labeled in a specific direction with respect to the liquid crystal cell; the second liquid crystal cell is a liquid crystal cell according to the first specification rotated by 90° with respect to the first liquid crystal cell about an axis in the direction of the optical axis of the first liquid crystal cell; LCD panel.

7. 2. The liquid crystal panel according to claim 1, the first aperture pattern is an aperture pattern that functions as an aperture for coded imaging, the second opening pattern is an opening pattern that functions as an opening having a circular shape with its center on the optical axis of the liquid crystal panel; LCD panel.

8. 2. The liquid crystal panel according to claim 1, the first aperture pattern is an aperture pattern that functions as an aperture for stereo imaging, the second opening pattern is an opening pattern that functions as an opening having a circular shape with its center on the optical axis of the liquid crystal panel; LCD panel.

9. The camera includes an optical system, a liquid crystal panel, and an image sensor. the imaging element receives light that has passed through the optical system and the liquid crystal panel; the liquid crystal panel includes a first liquid crystal cell and a second liquid crystal cell; the first liquid crystal cell and the second liquid crystal cell are arranged so that one cell surface of each cell is in contact with or faces each other and is close to each other, and the optical axes of each cell are parallel to or overlap each other; The first liquid crystal cell In the incident light control region of the first liquid crystal cell, a first guest-host liquid crystal having an alignment direction that can be a first direction perpendicular to the optical axis direction of the first liquid crystal cell and the optical axis direction; an orientation direction of the first guest-host liquid crystal in each region is changed under control of an electric field in each region in the incident light control region of the first liquid crystal cell, thereby forming a first opening pattern that functions as an aperture for imaging for distance measurement and a second opening pattern that functions as an aperture for imaging for non-distance measurement; The second liquid crystal cell comprises: In the incident light control region of the second liquid crystal cell, a second guest-host liquid crystal having an alignment direction that can be a second direction perpendicular to the optical axis direction of the second liquid crystal cell and the first direction, and the optical axis direction; an alignment direction of the second guest-host liquid crystal in each region of the incident light control region of the second liquid crystal cell is changed under control of an electric field in each region, thereby forming the first opening pattern and the second opening pattern; Imaging module.

10. The apparatus includes an optical system, a liquid crystal panel, an imaging element, and a control unit, the imaging element receives light that has passed through the optical system and the liquid crystal panel; the liquid crystal panel includes a first liquid crystal cell and a second liquid crystal cell; the first liquid crystal cell and the second liquid crystal cell are arranged so that one cell surface of each cell is in contact with or faces each other and is close to each other, and the optical axes of each cell are parallel to or overlap each other; The first liquid crystal cell In the incident light control region of the first liquid crystal cell, a first guest-host liquid crystal having an alignment direction that can be a first direction perpendicular to the optical axis direction of the first liquid crystal cell and the optical axis direction; an orientation direction of the first guest-host liquid crystal in each region is changed under control of an electric field in each region in the incident light control region of the first liquid crystal cell, thereby forming a first opening pattern that functions as an aperture for imaging for distance measurement and a second opening pattern that functions as an aperture for imaging for non-distance measurement; The second liquid crystal cell comprises: In the incident light control region of the second liquid crystal cell, a second guest-host liquid crystal having an alignment direction that can be a second direction perpendicular to the optical axis direction of the second liquid crystal cell and the first direction, and the optical axis direction; an alignment direction of the second guest-host liquid crystal in each region of the incident light control region of the second liquid crystal cell is changed under control of an electric field in each region, thereby forming the first opening pattern and the second opening pattern; The control unit controlling the liquid crystal panel and the image sensor so that the first opening pattern is formed in the first liquid crystal cell and the second liquid crystal cell, and the distance measurement imaging is performed; controlling the liquid crystal panel and the image sensor so that the second opening pattern is formed in the first liquid crystal cell and the second liquid crystal cell, and the non-distance imaging is performed; Imaging device.

11. The imaging device according to claim 10, The ranging imaging is coded imaging or stereo imaging. Imaging device.

12. 12. The imaging device according to claim 11, A calculation processing unit is provided, the arithmetic processing unit calculates a depth estimation value of a subject included in the captured image based on the captured image obtained by the coded imaging or the stereo imaging. Imaging device.

13. 13. The imaging device according to claim 12, the calculation processing unit generates a depth map based on the calculated subject depth estimation value. Imaging device.

Images