WO2025115904A1 - Inner mirror - Google Patents

Abstract

An inner mirror 100 according to the present invention comprises a liquid crystal optical element 102, a liquid crystal display device 103, and an imaging unit 104. The imaging unit 104 is disposed on the back surface side of the liquid crystal optical element 102, and is capable of capturing, between a visible light image and an infrared image, at least a visible light image by receiving light entering via the liquid crystal optical element 102. The liquid crystal optical element 102 has: a camera region 1021 that corresponds to the imaging unit 104 in a viewed direction X of the inner mirror 100; and a main region 1022 other than the camera region 1021. The camera region and the main region are each configured such that switching of the same is independently controllable between a reflector state and a transparent state. The liquid crystal display device 103 is disposed on the back surface side of the main region of the liquid crystal optical element 102, and has an outer shape that corresponds to the main region of the liquid crystal optical element 102 in the viewed direction X.

Description

Inner mirror

The present invention relates to an interior mirror for a vehicle.

Anti-glare mirrors are known as inner mirrors for vehicles that have a function (anti-glare function) to prevent the driver from being dazzled by the reflection of light from the headlights of following vehicles when driving at night. One example of an anti-glare mirror is the EC (Electrochromic) anti-glare mirror.

　EC anti-glare mirrors generally have an EC element on the front side of the mirror's reflective surface, and achieve the aforementioned anti-glare function by transitioning the operating state of the EC element (changing the amount of coloring) to control the reflectance. More specifically, as an anti-glare function, EC anti-glare mirrors increase the amount of coloring of the EC element to lower the reflectance when the rear light is bright and intense, depending on the amount of light from behind the vehicle (rear light), such as at night when it is dark around the vehicle, and decrease the amount of coloring of the EC element to increase the reflectance when the rear light is dark and intense, depending on the amount of light from behind the vehicle (rear light).

In addition, vehicle inner mirrors may be equipped with cameras used in DMS (Driver Monitoring System) and OMS (Occupant Monitoring System).

For example, Patent Document 1 discloses an inner mirror (rear-view mirror assembly) equipped with an IR (Infrared) light source that transmits radiation through an EC element (electro-optical element) and an IR camera (image sensor) that captures image data of an object via the EC element.

In Patent Document 1, the inner mirror monitors the ambient light communicated from the ambient light sensor and the glare light from the following vehicle communicated from the glare sensor. The inner mirror then controls the operating state (operating conditions) of the EC element in response to the ambient light and the glare light, controls the intensity of the radiation output from the IR light source through the EC element in cooperation with the operating state of the EC element, and identifies the vehicle occupants based on image data captured by the IR camera.

Patent No. 6811314

In the inner mirror of Patent Document 1, the EC element has low transmittance in the infrared region, and the transmittance in the infrared region varies with the control of the operating state of the EC element. Therefore, when taking pictures with the built-in IR camera, it is necessary to control (adjust) the output intensity (light amount, etc.) of the IR light source and the gain of the IR camera according to the operating state of the EC element. This results in problems such as the need for complex control and increased power consumption.

Furthermore, when considering incorporating an IR camera into an inner mirror that has a built-in LCD display for displaying images of the rear of the vehicle (inner mirror with image display function; electronic inner mirror), it is conceivable to position the IR camera in a position that avoids the LCD display on the rear side of the mirror element. However, in this case, there are problems such as the size of the inner mirror housing becoming larger.

In addition, when considering incorporating a color camera into the inner mirror, it is possible to adopt a configuration in which part of the mirror element is missing (part of the mirror reflective surface is removed) in order to ensure transmittance in the visible light range when taking pictures with the built-in color camera. However, in this case, the built-in color camera would be constantly visible to the driver and passengers, which would cause problems such as poor design.

Furthermore, when considering incorporating a color camera into an EC anti-glare mirror, even if a configuration is adopted in which part of the mirror reflective surface is eliminated, it is difficult to partially eliminate the EC cells of the EC element. This causes problems such as fluctuations in transmittance in the visible light range depending on the operating state of the EC element.

The present invention aims to provide an inner mirror that is suitable for taking good photos using a built-in camera.

According to the present invention, the inner mirror according to the first embodiment is characterized by comprising a liquid crystal optical element that can be switched between a reflecting mirror state and a transmitting state, and an imaging unit that is disposed on the rear side of the liquid crystal optical element and receives light incident through the liquid crystal optical element to capture at least one of a visible light image and an infrared image.

The inner mirror according to the second embodiment is characterized in that, in the first embodiment, the imaging unit is a camera capable of capturing at least a visible light image out of a visible light image and an infrared image, the liquid crystal optical element has a camera area corresponding to the imaging unit in the viewing direction of the inner mirror and a main area excluding the camera area, and the camera area and the main area are configured so that switching between a reflecting mirror state and a transparent state can be independently controlled.

The inner mirror according to the third embodiment is characterized in that in the second embodiment, the inner mirror further includes a liquid crystal display device that is disposed on the rear side of the main region of the liquid crystal optical element and has an outer shape that corresponds to the main region of the liquid crystal optical element in the viewing direction.

The inner mirror according to the fourth embodiment is characterized in that in the third embodiment, the imaging unit is a visible light/infrared camera capable of capturing visible light images and infrared images, the inner mirror further includes a light-emitting unit that is disposed on the rear side of the main region of the liquid crystal optical element and emits infrared light, and the liquid crystal display device has an outer shape that corresponds to an area of the main region of the liquid crystal optical element excluding the portion corresponding to the light-emitting unit in the viewing direction.

The inner mirror according to the fifth embodiment is characterized in that in the fourth embodiment, the inner mirror further includes a black mask member that is disposed between the main region and the light-emitting portion of the liquid crystal optical element, overlaps the light-emitting portion in the viewing direction, and has an outer shape that does not overlap the camera region of the liquid crystal optical element and the liquid crystal display device.

The inner mirror according to the sixth embodiment is the same as the fifth embodiment, except that the black mask member is made of a visible light blocking, infrared light transmitting material.

The seventh embodiment of the inner mirror is the third embodiment, and is characterized in that the imaging unit is a visible light/infrared camera capable of capturing visible light images and infrared images, the liquid crystal display device has a backlight, and at least a portion of the light source of the backlight is a light source capable of emitting infrared light.

The inner mirror according to the eighth embodiment is characterized in that in the second embodiment, the inner mirror further comprises a liquid crystal display device arranged on the rear side of the liquid crystal optical element, the liquid crystal display device has a second camera area corresponding to the camera area of the liquid crystal optical element in the viewing direction and a second main area excluding the second camera area, the visible light transmittance of the second camera area is higher than the visible light transmittance of the second main area, and the imaging unit receives light incident through the camera area of the liquid crystal optical element and the second camera area of the liquid crystal display device.

The inner mirror according to the ninth embodiment is the eighth embodiment, and is characterized in that the liquid crystal display device is configured such that there is no front polarizing plate, color filter, rear polarizing plate, or backlight in the second camera area.

The inner mirror according to the tenth embodiment is the eighth embodiment, and is characterized in that the liquid crystal display device is configured so that only the glass substrate is present in the second camera area.

The inner mirror according to the eleventh embodiment is characterized in that in the eighth embodiment, the liquid crystal display device is configured so that the second camera area is hollow.

The inner mirror according to the twelfth embodiment is the eighth embodiment, characterized in that the imaging unit is a visible light/infrared camera capable of capturing visible light images and infrared images.

The inner mirror according to the thirteenth embodiment is characterized in that in the second embodiment, the imaging unit is a visible light/infrared camera capable of capturing visible light images and infrared images, and the inner mirror further comprises a light-emitting unit that is disposed on the rear side of the main region of the liquid crystal optical element and emits infrared light, and a black mask member that is disposed between the main region of the liquid crystal optical element and the light-emitting unit and has an outer shape that overlaps with the light-emitting unit in the viewing direction and does not overlap with the camera region of the liquid crystal optical element.

The inner mirror according to the fourteenth embodiment is the thirteenth embodiment, characterized in that the black mask member has a first region corresponding to the light-emitting portion in the viewing direction and a second region excluding the first region, and the infrared transmittance of the first region is higher than the infrared transmittance of the second region.

The inner mirror according to the fifteenth embodiment is the fourteenth embodiment, characterized in that the first region of the black mask member is made of a visible light blocking, infrared light transmitting material.

The inner mirror according to the sixteenth embodiment is characterized in that in the first embodiment, the imaging unit is an infrared camera capable of capturing infrared images, and the inner mirror further includes a liquid crystal display device that is disposed on the rear side of the liquid crystal optical element and has an outer shape that corresponds to an area of the liquid crystal optical element excluding an area that corresponds to the imaging unit in the viewing direction of the inner mirror.

The inner mirror according to the seventeenth embodiment is the sixteenth embodiment, characterized in that the inner mirror is further provided with a light-emitting section that is arranged on the rear side of the liquid crystal optical element and emits infrared light, and the liquid crystal display device has an outer shape that corresponds to an area of the liquid crystal optical element in the viewing direction excluding the areas that correspond to the imaging section and the light-emitting section.

The inner mirror according to the eighteenth embodiment is the seventeenth embodiment, further comprising a black mask member disposed between the liquid crystal optical element and the light-emitting unit, and having an outer shape that overlaps at least the light-emitting unit in the viewing direction and does not overlap the liquid crystal display device.

The inner mirror according to the 19th embodiment is the 18th embodiment, characterized in that the black mask member is made of a visible light blocking, infrared light transmitting material.

The inner mirror according to the twentieth embodiment is the same as the inner mirror according to the sixteenth embodiment, characterized in that the liquid crystal display device has a backlight, and at least a portion of the light source of the backlight is a light source capable of emitting infrared rays.

The inner mirror according to the twenty-first embodiment is characterized in that in the first embodiment, the imaging unit is an infrared camera capable of capturing infrared images, and the inner mirror further includes a light-emitting unit that is disposed on the rear side of the liquid crystal optical element and emits infrared light, and a black mask member that is disposed between the liquid crystal optical element and the light-emitting unit.

The inner mirror according to the twenty-second embodiment is the twenty-first embodiment, characterized in that the black mask member has at least a third region corresponding to the light-emitting portion in the viewing direction of the inner mirror, and a fourth region excluding the third region, and the infrared transmittance of the third region is higher than the infrared transmittance of the fourth region.

The inner mirror according to the twenty-third embodiment is the twenty-second embodiment, characterized in that the third region of the black mask member is made of a visible light blocking, infrared light transmitting material.

The present invention provides an inner mirror that is ideal for taking good photos with a built-in camera.

1 is a diagram showing a configuration of an inner mirror according to a first embodiment. FIG. FIG. 2 is a diagram showing a functional configuration of an inner mirror according to the first embodiment. 1 is a cross-sectional view showing a schematic structure of a liquid crystal display according to a first embodiment. 11A and 11B are diagrams illustrating a configuration of an inner mirror according to a second embodiment. FIG. 11 is a diagram showing a functional configuration of an inner mirror according to a second embodiment. FIG. 11 is a cross-sectional view showing a schematic structure of a liquid crystal display according to a second embodiment. FIG. 11 is a cross-sectional view showing a schematic structure of a modified example of the liquid crystal display of the second embodiment. FIG. 11 is a cross-sectional view showing a schematic structure of a modified example of the liquid crystal display of the second embodiment. 13A and 13B are diagrams illustrating a configuration of an inner mirror according to a third embodiment. FIG. 11 is a diagram showing a functional configuration of an inner mirror according to a third embodiment. FIG. 13 is a diagram showing a configuration of an inner mirror according to a fourth embodiment. FIG. 13 is a diagram showing a functional configuration of an inner mirror according to a fourth embodiment. 13A and 13B are diagrams illustrating a configuration of an inner mirror according to a fifth embodiment. FIG. 13 is a diagram showing a functional configuration of an inner mirror according to a fifth embodiment.

Below, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiment. In each drawing, the same members or elements are given the same reference symbols, and duplicate descriptions are omitted or simplified.

First Embodiment
FIG. 1 is a diagram showing the configuration of an inner mirror 100 according to a first embodiment ((a) is a front view, and (b) is a vertical cross-sectional view).
The inner mirror 100 according to the first embodiment is configured as a liquid crystal anti-glare mirror with an image display function, and is installed at the upper end of the front window of a vehicle (not shown) such as a passenger car, in the center of the vehicle width direction.

The inner mirror 100 has two operating modes: a mirror mode (image display function off) and an image display mode (image display function on). In addition, the mirror mode has two operating states: a non-anti-glare state (anti-glare function off) and an anti-glare state (anti-glare function on).

The inner mirror 100 includes a housing 101, a liquid crystal optical element 102, a liquid crystal display 103, an RGB (Red, Green, Blue)-IR (Infrared) camera 104, an IR light source 105, a black mask member 106, a rear light sensor 107, an ambient light sensor 108, etc.

The housing 101 is, for example, a plastic molded part that forms the outer shape of the inner mirror 100, and has a shape that opens toward the front of the inner mirror 100 (the rear of the vehicle). Inside the housing 101, a liquid crystal optical element 102, a liquid crystal display 103, an RGB-IR camera 104, an IR light source 105, a black mask member 106, etc. are housed. Inside the housing 101, the liquid crystal optical element 102 is arranged near the opening, and on the rear side of the liquid crystal optical element 102, the liquid crystal display 103, the RGB-IR camera 104, the IR light source 105, the black mask member 106, etc. are arranged.

The liquid crystal optical element 102 is an element that can be electrically switched between a reflecting mirror state and a transmitting state, and functions as a mirror element (mirror reflecting surface). The liquid crystal optical element 102 has a configuration in which a liquid crystal cell is sandwiched between two polarizing plates, and can be switched between a state in which the visible light reflectance is high and the visible light transmittance is low (reflecting mirror state) and a state in which the visible light reflectance is low and the visible light transmittance is high (transmitting state) by controlling the driving voltage of the liquid crystal cell. The liquid crystal optical element 102 also has two independent regions, and the two regions are configured so that the switching between the reflecting mirror state and the transmitting state can be controlled individually. Here, the visible light reflectance and visible light transmittance are the reflectance and transmittance of light in the visible light region (wavelength range around 380 to 780 nm). In addition to the reflecting mirror state and transmitting state, the operating states of the liquid crystal optical element 102 may include a state in which the visible light reflectance is higher than the transmitting state and lower than the reflecting mirror state (low reflectance reflecting mirror state).

Such a liquid crystal optical element 102 has a well-known configuration and is also called a "shutter liquid crystal" or "mirror optical element," and detailed explanation of the configuration and operation will be omitted (see, for example, JP 2009-008881 A, WO 2018/061676 A, JP 2018-205363 A, JP 2020-008753 A, and JP 2021-110814 A).

It was confirmed that the following infrared transmittance and visible light transmittance were obtained for the evaluation sample of the liquid crystal optical element 102. Here, the infrared transmittance is the transmittance of light in the infrared region (wavelength range around 940 nm).

As a result of measurements on the evaluation sample, the infrared transmittance of the liquid crystal optical element 102 was approximately 77.4% when the liquid crystal optical element 102 was in the reflecting mirror state, and approximately 76.9% when the liquid crystal optical element 102 was in the transmitting state. In other words, the infrared transmittance of the liquid crystal optical element 102 remains high with almost no change between the reflecting mirror state and the transmitting state. Therefore, whether the liquid crystal optical element 102 is in the reflecting mirror state or the transmitting state, good infrared photography (capturing of infrared images) is possible with an IR camera or the like via the liquid crystal optical element 102.

The visible light transmittance of the liquid crystal optical element 102 was approximately 7.9% when the liquid crystal optical element 102 was in a reflecting mirror state, and approximately 39.4% when the liquid crystal optical element 102 was in a transmissive state. If the visible light transmittance of the liquid crystal optical element 102 in the transmissive state is approximately 39.4%, it is fully possible to capture visible light (capture a visible light image) using a color camera or the like via the liquid crystal optical element 102 in the transmissive state.

The liquid crystal optical element 102 has two regions that can be independently controlled to switch between a reflecting mirror state and a transmitting state: a camera region 1021 that corresponds to the RGB-IR camera 104 in the viewing direction X of the inner mirror 100, and a main region 1022 excluding the camera region 1021. In other words, the liquid crystal optical element 102 is equivalent to an integrated liquid crystal optical element that forms the camera region 1021 and the main region 1022, respectively. Here, the viewing direction X of the inner mirror 100 is a direction perpendicular to the front surface (viewed surface) of the inner mirror 100.

The size, ratio, shape, arrangement, etc. of the camera region 1021 and main region 1022 in the liquid crystal optical element 102 are arbitrary. However, since wiring must be drawn from the outer edge of the liquid crystal optical element 102 to the boundary between the camera region 1021 and the main region 1022, arranging the camera region 1021 in a corner (e.g., the upper left corner) of the liquid crystal optical element 102 makes wiring processing for the boundary of the camera region 1021 easier.

The camera region 1021 of the liquid crystal optical element 102 switches between a transmissive state and a reflective mirror state in synchronization with the main region 1022 of the liquid crystal optical element 102 in mirror mode, and is in the reflective mirror state in image display mode. The camera region 1021 of the liquid crystal optical element 102 may be in the transmissive state in image display mode. The camera region 1021 of the liquid crystal optical element 102 is also in the transmissive state when visible light photography is performed by the RGB-IR camera 104. The main region 1022 of the liquid crystal optical element 102 switches between a transmissive state and a reflective mirror state in synchronization with the camera region 1021 of the liquid crystal optical element 102 in mirror mode, and is in the transmissive state in image display mode.

The liquid crystal display 103 is disposed on the rear side of the main region 1022 of the liquid crystal optical element 102. The liquid crystal display 103 has an outer shape corresponding to the area of the main region 1022 of the liquid crystal optical element 102 excluding the part corresponding to the IR light source 105 in the viewing direction X of the inner mirror 100. The liquid crystal display 103 is turned off in the mirror mode and turned on in the image display mode. The liquid crystal display 103 is capable of displaying images of the rear of the vehicle captured by the rear camera 116, etc. The rear camera 116 is disposed, for example, at a central position in the width direction of the vehicle at the exterior rear of the vehicle, with its optical axis facing horizontally to the rear of the vehicle.

The RGB-IR camera 104 is disposed on the rear side of the liquid crystal optical element 102 (camera area 1021). The RGB-IR camera 104 is a camera capable of capturing visible light images and infrared images, and receives light incident through the liquid crystal optical element 102 (camera area 1021).

For example, the RGB-IR camera 104 has a pixel group for capturing visible light images and a pixel group for capturing infrared images, and a downstream image processing circuit or the like can obtain an RGB image signal using the signal from the pixel group for capturing visible light images, and an IR image signal can be obtained using the signal from the pixel group for capturing infrared images. Note that the RGB-IR camera 104 may also be configured using a color camera (RGB camera) and an IR camera that are provided separately.

The RGB-IR camera 104 is used to capture infrared images of the driver and passengers in the vehicle cabin for the purpose of image recognition (detection of drowsiness, detection of gaze direction, facial recognition, determination of the presence or absence of passengers, etc.) for driver/passenger monitoring by the DMS/OMS installed in the vehicle.

When the DMS/OMS requests infrared photography for driver/passenger monitoring, the RGB-IR camera 104 turns on to obtain an IR image signal, and receives light incident from inside the vehicle cabin through the liquid crystal optical element 102 (camera area 1021) to capture an infrared image.

The RGB-IR camera 104 can also be used to capture visible light images of the driver and passengers inside the vehicle, for example for video conferencing or snapshots inside the vehicle.

When the driver or passenger operates a switch mounted on the inner mirror 100 to request visible light photography for a video conference or snapshot, the RGB-IR camera 104 turns on to obtain an RGB image signal, and captures a visible light image by receiving light incident from within the vehicle cabin through the liquid crystal optical element 102 (camera area 1021).

The IR light source 105 is disposed on the rear side of the main region 1021 (black mask member 106) of the liquid crystal optical element 102, and is capable of emitting infrared rays. The IR light source 105 is turned on when infrared photography is performed by the RGB-IR camera 104, and emits infrared rays toward the interior of the vehicle cabin via the black mask member 106 and the main region 1022 of the liquid crystal optical element 102.

The black mask member 106 is disposed between the main region 2021 of the liquid crystal optical element 102 and the IR light source 105. The black mask member 106 has an outer shape that overlaps with the IR light source 105 in the viewing direction X of the inner mirror 100 and does not overlap with the camera region 1022 of the liquid crystal optical element 102 and the liquid crystal display 310.

For example, the black mask member 106 is made of a visible light blocking/infrared transmitting material that blocks (absorbs) visible light and transmits infrared light. The visible light blocking/infrared transmitting material that constitutes the black mask member 106 is, for example, a "NIR (infrared) filter" made by Nitto Plastics Corporation/CLAREX.

The rear light sensor 107 detects the brightness (amount of light) of light (rear light) from the rear of the vehicle. The rear light sensor 107 is disposed at the lower end of the housing 101 of the inner mirror 100, etc., facing the front of the inner mirror 100 (the rear of the vehicle).

The ambient light sensor 108 detects the brightness (amount of light) of the light (ambient light) from around the vehicle. The ambient light sensor 108 is disposed on the housing 101 of the inner mirror 100 facing the rear of the inner mirror 100 (the front of the vehicle).

The detection results of the rear light sensor 107 and the ambient light sensor 108 are used to control the switching of the liquid crystal optical element 102 between a reflecting mirror state and a transmitting state.

FIG. 2 is a diagram showing the functional configuration of the inner mirror 100 according to the first embodiment.
The inner mirror 100 includes an automatic anti-glare control unit 111, a monitoring system control unit 112, a camera linkage control unit 113, a display control unit 114, and the like.

For example, the automatic anti-glare control unit 111, the monitoring system control unit 112, the camera linkage control unit 113 and the display control unit 114 are realized by a CPU (Central Processing Unit) on a control board mounted on the inner mirror 100, or by an ECU (Electronic Control Unit) mounted on the vehicle and providing overall control of each part of the entire vehicle, or by a combination of these.

The liquid crystal optical element 102, the rear light sensor 107, and the ambient light sensor 108 are connected to the automatic anti-glare control unit 111. In the image display mode, the automatic anti-glare control unit 111 sets the main region 1022 of the liquid crystal optical element 102 to a transparent state. Note that the automatic anti-glare control unit 111 may set both the camera region 1021 and the main region 1022 of the liquid crystal optical element 102 to a transparent state in the image display mode.

In mirror mode, the automatic anti-glare control unit 111 determines whether or not to transition from a non-anti-glare state to an anti-glare state/from an anti-glare state to a non-anti-glare state based on the amount of rear light and the amount of ambient light detected by the rear light sensor 107 and the ambient light sensor 108. Then, the automatic anti-glare control unit 111 switches the camera area 1021 and main area 1022 of the liquid crystal optical element 102 between a transmissive state and a reflective mirror state depending on the determination result.

For example, in mirror mode, when the amount of rear light and the amount of ambient light satisfy the specified non-anti-glare conditions, the automatic anti-glare control unit 111 determines that it is not necessary to transition from the non-anti-glare state to the anti-glare state, and maintains the camera area 1021 and main area 1022 of the liquid crystal optical element 102 in the reflecting mirror state. Then, when the amount of rear light and the amount of ambient light transition to a state that satisfies the specified anti-glare conditions, the automatic anti-glare control unit 111 determines that it is necessary to transition from the non-anti-glare state to the anti-glare state, and switches the camera area 1021 and main area 1022 of the liquid crystal optical element 102 from the reflecting mirror state to the transparent state.

On the other hand, when the amount of rear light and the amount of ambient light satisfy the specified anti-glare conditions, the automatic anti-glare control unit 111 determines that there is no need to transition from the anti-glare state to the non-anti-glare state, and maintains the camera area 1021 and main area 1022 of the liquid crystal optical element 102 in a transparent state. Then, when the amount of rear light and the amount of ambient light transition to a state that satisfies the specified non-anti-glare conditions, the automatic anti-glare control unit 111 determines that there is a need to transition from the anti-glare state to the non-anti-glare state, and switches the camera area 1021 and main area 1022 of the liquid crystal optical element 102 from the transparent state to the reflecting mirror state.

The RGB-IR camera 104 and the IR light source 105 are connected to the surveillance system control unit 112. The liquid crystal optical element 102, the automatic anti-glare control unit 111, and the surveillance system control unit 112 are connected to the camera linkage control unit 113.

The monitoring system control unit 112 controls the RGB-IR camera 104 and the IR light source 105 for driver/passenger monitoring in response to instructions from the DMS/OMS. When the DMS/OMS requests infrared photography (photography for driver/passenger monitoring) using the RGB-IR camera 104, the monitoring system control unit 112 turns on the RGB-IR camera 104 to obtain an IR image signal and turns on the IR light source 105. At this time, for example, the IR light source 105 is driven intermittently in conjunction with a synchronization signal from the RGB-IR camera 104.

In addition, when the driver or passenger operates a switch to request visible light photography (photography for video conferencing or snapshots) using the RGB-IR camera 104 via the DMS/OMS, the monitoring system control unit 112 instructs the camera linkage control unit 113 to transition the camera area 1021 of the liquid crystal optical element 102 to a transparent state.

The camera linkage control unit 113 puts the camera area 1021 of the liquid crystal optical element 102 into a transparent state based on instructions from the monitoring system control unit 112. The monitoring system control unit 112 then turns on the RGB-IR camera 104 to acquire an RGB image signal.

The display control unit 114 is connected to the LCD display 103, the automatic anti-glare control unit 111, and the rear camera 116. The display control unit 114 turns off the LCD display 103 in the mirror mode.

When in image display mode, the display control unit 114 turns on the liquid crystal display 103 in response to the automatic anti-glare control unit 111 putting the main region 1022 of the liquid crystal optical element 102 into a transparent state, and causes the liquid crystal display 103 to display an image of the rear of the vehicle captured by the rear camera 116, etc.

FIG. 3 is a cross-sectional view showing a schematic structure of the liquid crystal display 103 of the first embodiment.
The liquid crystal display 103 is formed by overlapping a plurality of functional layers. The liquid crystal display 103 has a polarizing plate 103a, a glass substrate 103b, an RGB color filter 103c, an ITO (Indium Tin Oxide) transparent electrode film 103d, an alignment film 103e, a liquid crystal layer 103f, an alignment film 103g, a TFT (Thin Film Transistor) circuit and a transparent electrode film 103h, a glass substrate 103i, a polarizing plate 103j, and a backlight 103k. In the liquid crystal display 103, the functional layers 103a to 103k are sequentially arranged from the front side to the back side of the inner mirror 100 (from the rear to the front of the vehicle).

This type of LCD display 103 has a well-known configuration, and detailed explanation of its configuration and operation will be omitted.

Here, the backlight 103k of the liquid crystal display 103 is configured using a light source that emits (radiates) visible light, for example. However, some or all of the light sources of the backlight 103k of the liquid crystal display 103 may be changed from those that emit visible light to those that emit infrared light.

This allows the backlight 103k of the liquid crystal display 103 to also serve as the IR light source 105, eliminating the need for an IR light source 105. By eliminating the need for the IR light source 105, it is possible to improve the freedom of component placement inside the housing 101 and reduce costs by reducing the number of components.

Also, if the IR light source 105 is not provided, the liquid crystal display 103 may have an outer shape that corresponds to the main region 1022 of the liquid crystal optical element 102 in the viewing direction X of the inner mirror 100.

In this case, the outer shape of the liquid crystal display 103 is enlarged by the area that corresponds to the IR light source 105 in the viewing direction X of the inner mirror 100. This makes it possible to enlarge the display surface of the liquid crystal display 103, and as a result, it becomes possible to enlarge the image display area on the viewing surface of the inner mirror 100.

Here, we will explain the operation of the inner mirror 100 in mirror mode (non-anti-glare state/anti-glare state) and in image display mode.

[Operation in mirror mode (non-anti-glare state/anti-glare state)]
The liquid crystal display 103 is turned off by the display control unit 114. Also, the automatic anti-glare control unit 111 determines whether or not a transition from a non-anti-glare state to an anti-glare state/a transition from the anti-glare state to the non-anti-glare state is required.

When the automatic anti-glare control unit 111 determines that it is not necessary to transition from the non-anti-glare state to the anti-glare state, the automatic anti-glare control unit 111 sets the camera area 1021 and main area 1022 of the liquid crystal optical element 102 to a reflective mirror state (visible light reflectance: high). As a result, the operating mode of the inner mirror 100 becomes mirror mode and non-anti-glare state, and a reflected image in the non-anti-glare state appears on the visible surface of the inner mirror 100. Also, when the automatic anti-glare control unit 111 determines that it is necessary to transition from the non-anti-glare state to the anti-glare state, the automatic anti-glare control unit 111 sets the camera area 1021 and main area 1022 of the liquid crystal optical element 102 to a transparent state (visible light reflectance: low). As a result, the operating mode of the inner mirror 100 becomes mirror mode and anti-glare state, and a reflected image in the anti-glare state appears on the visible surface of the inner mirror 100.

On the other hand, if the automatic anti-glare control unit 111 determines that it is not necessary to transition from the anti-glare state to the non-anti-glare state, the automatic anti-glare control unit 111 sets the camera area 1021 and main area 1022 of the liquid crystal optical element 102 to a transparent state (visible light reflectance: low). As a result, the operating mode of the inner mirror 100 becomes mirror mode and anti-glare state, and a reflected image in the anti-glare state appears on the visible surface of the inner mirror 100. Also, if the automatic anti-glare control unit 111 determines that it is necessary to transition from the anti-glare state to the non-anti-glare state, the automatic anti-glare control unit 111 sets the camera area 1021 and main area 1022 of the liquid crystal optical element 102 to a reflective mirror state (visible light reflectance: high). As a result, the operating mode of the inner mirror 100 becomes mirror mode and non-anti-glare state, and a reflected image in the non-anti-glare state appears on the visible surface of the inner mirror 100.

[Image display mode operation]
The display control unit 114 turns on the liquid crystal display 103, and an image of the rear of the vehicle captured by the rear camera 116 is displayed on the liquid crystal display 103. The automatic anti-glare control unit 111 also turns the main region 1022 of the liquid crystal optical element 102 into a transparent state (visible light transmittance: high). As a result, an image of the rear of the vehicle captured by the rear camera 116 and displayed on the liquid crystal display 103 appears on the visible surface of the inner mirror 100.

Next, we will explain the operation of the built-in camera of the inner mirror 100 when capturing infrared images and visible light images. Note that the operation of the built-in camera when capturing infrared images and visible light images is common to both mirror mode (non-anti-glare state/anti-glare state) and image display mode.

[Infrared photography using the built-in camera]
When the DMS/OMS requests infrared photography by the RGB-IR camera 104, the monitoring system control unit 112 turns on the IR light source 105 to emit infrared light, and turns on the RGB-IR camera 104 to obtain an IR image signal and capture an infrared image. At this time, for example, the IR light source 105 is intermittently driven in conjunction with a synchronization signal of the RGB-IR camera 104. In this way, infrared photography is performed by the RGB-IR camera 104 for driver/passenger monitoring.

[Operation when capturing visible light images with the built-in camera]
When a driver or passenger operates a switch to request visible light photography by the RGB-IR camera 104, the camera linkage control unit 113 sets the camera area 1021 of the liquid crystal optical element 102 to a transparent state (visible light transmittance: high). Then, the monitoring system control unit 112 sets the RGB-IR camera 104 to an on state to obtain an RGB image signal and capture a visible light image. This allows visible light photography by the RGB-IR camera 104 to be performed for video conferencing or snapshots.

In the inner mirror 100 according to the first embodiment described above, the infrared transmittance of the liquid crystal optical element 102 (camera area 1021) is maintained high regardless of the operating state (reflecting mirror state/transmitting state) of the liquid crystal optical element 102. Therefore, when taking infrared images using the RGB-IR camera 104, there is no need to control the gain of the RGB-IR camera 104 or the light amount of the IR light source 105 according to the operating state of the liquid crystal optical element 102. This eliminates the need for complex control, simplifies control, and reduces power consumption.

The liquid crystal optical element 102 is also configured so that the camera area 1021 and main area 1022 can be independently controlled to switch between a reflecting mirror state and a transmitting state. This allows the camera area 1021 of the liquid crystal optical element 102 to be switched to a transmitting state while maintaining the operating state (reflecting mirror state/transmitting state) of the main area 1022 of the liquid crystal optical element 102 when capturing visible light images using the RGB-IR camera 104. Therefore, in the intermirror 100, visible light capture can be performed using the built-in camera without affecting the operation of the mirror mode/image display mode.

The liquid crystal display 103 arranged on the rear side of the main region 1022 of the liquid crystal optical element 102 has an outer shape corresponding to the area of the main region 1022 of the liquid crystal optical element 102 excluding the part corresponding to the IR light source 105. This makes it easy to secure a space for arranging the IR light source 105 on the rear side of the main region 1022 of the liquid crystal optical element 102.

The black mask member 106 has an outer shape that overlaps with the IR light source 105 but does not overlap with the camera area 1021 of the liquid crystal optical element 102 or the liquid crystal display 103, and is made of a visible light blocking, infrared light transmitting material. This makes it easy to realize a structure that prevents the light emitted by the IR light source 105 from being noticed by the driver or passengers.

Furthermore, by making some or all of the light sources of the backlight 103k of the liquid crystal display 103 emit infrared rays, the backlight 103k of the liquid crystal display 103 can also serve as the IR light source 105, making the IR light source 105 unnecessary. As a result, this contributes to improving the freedom of component placement inside the housing 101 and reducing costs by reducing the number of components.

In this case, by making the liquid crystal display 103 have an outer shape that corresponds to the main region 1022 of the liquid crystal optical element 102, the outer shape of the liquid crystal display 103 can be enlarged by the area that corresponds to the IR light source 105. This allows the display surface of the liquid crystal display 103 to be enlarged, and as a result, the image display area on the visible surface of the inner mirror 100 can be enlarged.

In this way, the inner mirror 100 according to the first embodiment is ideal for achieving good image capture using the built-in camera.

Second Embodiment
4A and 4B are diagrams showing the configuration of an inner mirror 200 according to the second embodiment ((a) is a front view, and (b) is a vertical cross-sectional view).
The inner mirror 200 according to the second embodiment is configured as a liquid crystal anti-glare mirror with an image display function, and is installed at the upper end of the front window of a vehicle (not shown) such as a passenger car, in the center of the vehicle width direction.

The inner mirror 200 has two operating modes: a mirror mode (image display function off) and an image display mode (image display function on). In addition, the mirror mode has two operating states: a non-anti-glare state (anti-glare function off) and an anti-glare state (anti-glare function on).

The inner mirror 200 has a housing 101, a liquid crystal optical element 202, a liquid crystal display 203, an RGB-IR camera 104, an IR light source 105, a rear light sensor 107, an ambient light sensor 108, etc.

The liquid crystal optical element 202 corresponds to the liquid crystal optical element 102 of the first embodiment (Fig. 1) in which the size, ratio, shape, arrangement, etc. of the camera region 1021 and the main region 1022 are changed to form the camera region 2021 and the main region 2022.

The liquid crystal display 203 is disposed on the rear side of the liquid crystal optical element 202. The liquid crystal display 203 has two areas. That is, the liquid crystal display 203 has a camera area 2031 that corresponds to the RGB-IR camera 104 in the viewing direction X of the inner mirror 200, and a main area 2032 excluding the camera area 2031.

The two regions of the liquid crystal display 203 correspond to the two regions of the liquid crystal optical element 202. That is, the camera region 2031 of the liquid crystal display 203 corresponds to the camera region 2021 of the liquid crystal optical element 202, and the main region 2032 of the liquid crystal display 203 corresponds to the main region 2022 of the liquid crystal optical element 202.

The size, ratio, shape, arrangement, etc. of the camera area 2021 and the main area 2022 in the liquid crystal optical element 202 are arbitrary. However, the camera area 2031 of the liquid crystal display 203 always corresponds to the camera area 2021 of the liquid crystal optical element 202, and the main area 2032 of the liquid crystal display 203 always corresponds to the main area 2022 of the liquid crystal optical element 202.

The LCD display 203 is turned off in mirror mode and turned on in image display mode. The LCD display 203 can display images of the rear of the vehicle captured by the rear camera 116, etc.

The RGB-IR camera 104 is disposed on the rear side of the liquid crystal display 203. The RGB-IR camera 104 receives light incident from inside the vehicle cabin through the camera area 2021 of the liquid crystal optical element 202 and the camera area 2031 of the liquid crystal display 203, and captures visible light images and infrared images.

The IR light source 105 is disposed on the rear side of the liquid crystal display 203. The IR light source 105 emits infrared rays toward the interior of the vehicle cabin via the main area 2032 of the liquid crystal display 203 and the main area 2022 of the liquid crystal optical element 202.

FIG. 5 is a diagram showing the functional configuration of an inner mirror 200 according to the second embodiment.
The inner mirror 200 includes an automatic anti-glare control unit 111, a monitoring system control unit 112, a camera linkage control unit 113, a display control unit 114, and the like.

The control operations of the automatic anti-glare control unit 111, the camera linkage control unit 113, and the display control unit 114 in the second embodiment are the same as those in the first embodiment, except that the liquid crystal optical element 102 (camera area 1021, main area 1022) and the liquid crystal display 103 are replaced with a liquid crystal optical element 202 (camera area 2021, main area 2022) and a liquid crystal display 203. The control operation of the surveillance system control unit 112 in the second embodiment is the same as that in the first embodiment.

FIG. 6 is a cross-sectional view showing a schematic structure of a liquid crystal display 203 according to the second embodiment.
The liquid crystal display 203 corresponds to the liquid crystal display 103 of the first embodiment (FIG. 3) from which the polarizing plate 103a, the RGB color filter 103c, the polarizing plate 103j, and the backlight 103k have been partially removed.

The liquid crystal display 203 is configured so that the visible light transmittance of the camera area 2031 is higher than the visible light transmittance of the main area 2032. Specifically, the liquid crystal display 203 has the polarizing plate 103a, the RGB color filter 103c, the polarizing plate 103j, and the backlight 103k removed in the camera area 2031.

In other words, the liquid crystal display 203 is configured so that the polarizing plate 103a, the RGB color filter 103c, the polarizing plate 103j, and the backlight 103k are not present in the camera area 2031.

In addition, the liquid crystal display 203 may have only one of the polarizing plates 103a and 103j removed in the camera area 2031, rather than both polarizing plates 103a and 103j. Also, the RGB-IR camera 104 may be positioned so as to enter the gap formed by removing the backlight 103k, etc., in the camera area 2031 of the liquid crystal display 203.

It was confirmed that the following infrared transmittance and visible light transmittance were obtained for the evaluation sample of the liquid crystal optical element 202 and the liquid crystal display 203. Note that the infrared transmittance and visible light transmittance of the liquid crystal optical element 202 are the same as those of the liquid crystal optical element 102 of the first embodiment.

As a result of measurements on the evaluation sample, the visible light transmittance of the main area 2032 of the LCD 203 was nearly 0%. On the other hand, the visible light transmittance of the camera area 2031 of the LCD 203 (where the polarizing plate 103a, RGB color filter 103c, polarizing plate 103j and backlight 103k have been removed and do not exist) was approximately 56.7%.

In addition, the infrared transmittance of the configuration in which the camera area 2021 of the liquid crystal optical element 202 and the camera area 2031 of the liquid crystal display 203 were combined was approximately 40.8% when the camera area 2021 of the liquid crystal optical element 202 was in a reflecting mirror state, and approximately 40.7% when the camera area 2021 of the liquid crystal optical element 202 was in a transmitting state.

In other words, the infrared transmittance of this configuration remains almost unchanged between the reflecting mirror state and the transmitting state of the camera area 2021 of the liquid crystal optical element 202. Therefore, whether the camera area 2021 of the liquid crystal optical element 202 is in the reflecting mirror state or the transmitting state, infrared photography is fully possible with an IR camera or the like via the camera area 2021 of the liquid crystal optical element 202 and the camera area 2031 of the liquid crystal display 203.

The visible light transmittance of the configuration in which the camera area 2021 of the liquid crystal optical element 202 and the camera area 2031 of the liquid crystal display 203 were combined was approximately 4.5% when the camera area 2021 of the liquid crystal optical element 202 was in a reflecting mirror state, and approximately 22.3% when the camera area 2021 of the liquid crystal optical element 202 was in a transmitting state.

If the visible light transmittance of this configuration is approximately 22.3% when the camera area 2021 of the liquid crystal optical element 202 is in a transmissive state, visible light photography is possible with a color camera or the like via the camera area 2021 of the liquid crystal optical element 202 in a transmissive state and the camera area 2031 of the liquid crystal display 203.

7 and 8 are cross-sectional views showing a schematic structure of a modified example of the liquid crystal display 203 of the second embodiment.
7, the camera region 2031 of the liquid crystal display 203 may be composed of only the glass substrate 103b and the glass substrate 103i, and the remaining functional layers may be absent (voids). That is, the liquid crystal display 203 may be configured such that only the glass substrate 103b and the glass substrate 103i are present in the camera region 2031.

For such a modified liquid crystal display 203, the visible light transmittance of the camera area 2031 of the liquid crystal display 203 obtained as a measurement result for an evaluation sample was approximately 81%. Therefore, good visible light photography can be achieved with a color camera or the like via the camera area 2021 of the liquid crystal optical element 202 in a transmissive state and the camera area 2031 of the liquid crystal display 203.

Also, as shown in FIG. 8, the camera region 2031 of the liquid crystal display 203 may be such that all of the components of the functional layers 103a to 103k are absent (void). In other words, the liquid crystal display 203 may be configured so that the camera region 2031 is completely hollow.

For such modified liquid crystal display 203, the visible light transmittance of the camera area 2031 of the liquid crystal display 203 obtained as a measurement result of the evaluation sample was nearly 100%. Therefore, better visible light photography can be achieved with a color camera or the like via the camera area 2021 of the liquid crystal optical element 202 in a transmissive state and the camera area 2031 of the liquid crystal display 203.

Here, the operation of the inner mirror 200 in the mirror mode and the image display mode corresponds to the operation of the inner mirror 100 in the first embodiment in the mirror mode and the image display mode, with the liquid crystal optical element 102 (camera area 1021, main area 1022) and the liquid crystal display 103 replaced with a liquid crystal optical element 202 (camera area 2021, main area 2022) and a liquid crystal display 203.

Furthermore, the operation of the built-in camera of the inner mirror 200 when capturing infrared images and when capturing visible light images corresponds to the operation of the built-in camera of the inner mirror 100 according to the first embodiment when capturing infrared images and when capturing visible light images, with the camera area 1021 of the liquid crystal optical element 102 being replaced with the camera area 2021 of the liquid crystal optical element 202.

The inner mirror 200 according to the second embodiment as described above also provides the same effects as the inner mirror 100 according to the first embodiment. That is, the infrared transmittance of the liquid crystal optical element 202 (camera area 2021) is maintained high regardless of the operating state (reflecting mirror state/transmitting state) of the liquid crystal optical element 202. Therefore, when taking infrared images using the RGB-IR camera 104, there is no need to control the gain of the RGB-IR camera 104 or the light amount of the IR light source 105 according to the operating state of the liquid crystal optical element 202. This eliminates the need for complex control, simplifies control, and reduces power consumption.

The liquid crystal optical element 202 is also configured so that the camera area 2021 and main area 2022 can be independently controlled to switch between a reflecting mirror state and a transmitting state. This allows the camera area 2021 of the liquid crystal optical element 202 to be switched to a transmitting state while maintaining the operating state (reflecting mirror state/transmitting state) of the main area 2022 of the liquid crystal optical element 202 when capturing visible light images using the RGB-IR camera 104. Therefore, in the intermirror 200, visible light capturing can be performed using the built-in camera without affecting the operation of the mirror mode/image display mode.

The liquid crystal display 203 also has a camera area 2031 and a main area 2032, and is configured so that the visible light transmittance of the camera area 2031 is higher than the visible light transmittance of the main area 2032. This enables good visible light imaging with the RGB-IR camera 104 via the camera area 2021 of the liquid crystal optical element 202 in a transmissive state and the camera area 2031 of the liquid crystal display 203.

The liquid crystal display 203 is configured so that the polarizing plate 103a, the RGB color filter 103c, the polarizing plate 103j, and the backlight 103k are not present in the camera region 2031. Alternatively, the liquid crystal display 203 is configured so that only the glass substrate 103b and the glass substrate 103i are present in the camera region 2031. Alternatively, the liquid crystal display 203 is configured so that the camera region 2031 is hollow. This makes it easy to realize a structure in the liquid crystal display 203 where the visible light transmittance of the camera region 2031 is higher than the visible light transmittance of the main region 2032.

In this way, the inner mirror 200 according to the second embodiment is ideal for achieving good image capture using the built-in camera.

Third Embodiment
9A and 9B are diagrams showing the configuration of an inner mirror 300 according to a third embodiment ((a) is a front view, and (b) is a vertical cross-sectional view).
The inner mirror 300 according to the third embodiment is configured as a liquid crystal anti-glare mirror, and is installed at the upper end of the center of the front window in the vehicle width direction of a vehicle (not shown), such as a passenger car.

The inner mirror 300 has two operating states: a non-anti-glare state (anti-glare function off) and an anti-glare state (anti-glare function on).

The inner mirror 300 includes a housing 101, a liquid crystal optical element 102, an RGB-IR camera 104, an IR light source 105, a black mask member 306, a rear light sensor 107, an ambient light sensor 108, etc.

The inner mirror 300 corresponds to the inner mirror 100 according to the first embodiment (Fig. 1) except that the liquid crystal display 103 is not provided and a black mask member 306 is provided instead of the black mask member 106.

The black mask member 306 is disposed between the main region 1022 of the liquid crystal optical element 102 and the IR light source 105. The black mask member 306 has an outer shape that overlaps with the IR light source 105 in the viewing direction X of the inner mirror 300 and does not overlap with the camera region 1021 of the liquid crystal optical element 102.

The black mask member 306 also has a first region 3061 that corresponds to the IR light source 105 in the viewing direction X of the inner mirror 300, and a second region 3062 excluding the first region 3061. The black mask member 306 is configured so that the infrared transmittance of the first region 3061 is higher than the infrared transmittance of the second region 3062.

For example, the first region 3061 of the black mask member 306 is made of a visible light blocking/infrared transmitting material (such as "NIR (infrared) filter" product by Nitto Plastics Corporation/CLAREX). The second region 3062 of the black mask member 306 is made of a visible light blocking material that blocks (absorbs) visible light (which does not transmit infrared rays as compared to the visible light blocking/infrared transmitting material).
The black mask member 306 may be entirely made of a visible light blocking, infrared transmitting material, so that the infrared transmittance is uniform.

FIG. 10 is a diagram showing the functional configuration of an inner mirror 300 according to the third embodiment.
The inner mirror 300 has an automatic anti-glare control unit 111, a monitoring system control unit 112, a camera linkage control unit 113, etc. The control operations of the automatic anti-glare control unit 111, the monitoring system control unit 112, and the camera linkage control unit 113 in the third embodiment are the same as the control operations in the first embodiment.

Here, we will explain the operation of the inner mirror 300 in the non-anti-glare state/anti-glare state. Note that the operation when capturing infrared images and visible light images using the built-in camera of the inner mirror 300 is the same as the operation when capturing infrared images and visible light images using the built-in camera of the inner mirror 100 according to the first embodiment.

[Operation in non-anti-glare state/anti-glare state]
In the automatic anti-glare control unit 111, it is determined whether or not a transition from a non-anti-glare state to an anti-glare state/a transition from an anti-glare state to a non-anti-glare state is required.

When the automatic anti-glare control unit 111 determines that it is not necessary to transition from the non-anti-glare state to the anti-glare state, the automatic anti-glare control unit 111 sets the camera area 1021 and main area 1022 of the liquid crystal optical element 102 to a reflective mirror state (visible light reflectance: high). As a result, the operating state of the inner mirror 300 becomes a non-anti-glare state, and a reflected image of the non-anti-glare state appears on the visible surface of the inner mirror 300. Also, when the automatic anti-glare control unit 111 determines that it is necessary to transition from the non-anti-glare state to the anti-glare state, the automatic anti-glare control unit 111 sets the camera area 1021 and main area 1022 of the liquid crystal optical element 102 to a transparent state (visible light reflectance: low). As a result, the operating state of the inner mirror 300 becomes an anti-glare state, and a reflected image of the anti-glare state appears on the visible surface of the inner mirror 300.

On the other hand, if the automatic anti-glare control unit 111 determines that it is not necessary to transition from the anti-glare state to the non-anti-glare state, the automatic anti-glare control unit 111 sets the camera area 1021 and main area 1022 of the liquid crystal optical element 102 to a transparent state (visible light reflectance: low). As a result, the operating state of the inner mirror 300 becomes the anti-glare state, and a reflected image of the anti-glare state appears on the visible surface of the inner mirror 300. Also, if the automatic anti-glare control unit 111 determines that it is necessary to transition from the anti-glare state to the non-anti-glare state, the automatic anti-glare control unit 111 sets the camera area 1021 and main area 1022 of the liquid crystal optical element 102 to a reflecting mirror state (visible light reflectance: high). As a result, the operating state of the inner mirror 300 becomes the non-anti-glare state, and a reflected image of the non-anti-glare state appears on the visible surface of the inner mirror 300.

The inner mirror 300 (liquid crystal anti-glare mirror (without image display function)) according to the third embodiment as described above also provides the same effects as the inner mirror 100 (liquid crystal anti-glare mirror with image display function) according to the first embodiment. That is, the infrared transmittance of the liquid crystal optical element 102 (camera area 1021) is maintained high regardless of the operating state (reflecting mirror state/transmitting state) of the liquid crystal optical element 102. For this reason, when taking infrared images using the RGB-IR camera 104, there is no need to control the gain of the RGB-IR camera 104 or the light amount of the IR light source 105 according to the operating state of the liquid crystal optical element 102. This eliminates the need for complex control, simplifies control, and reduces power consumption.

The liquid crystal optical element 102 is also configured so that the camera area 1021 and main area 1022 can be independently controlled to switch between a reflecting mirror state and a transmitting state. This allows the camera area 1021 of the liquid crystal optical element 102 to be switched to a transmitting state while maintaining the operating state (reflecting mirror state/transmitting state) of the main area 1022 of the liquid crystal optical element 102 when capturing visible light images using the RGB-IR camera 104. Therefore, in the intermirror 300, visible light capturing can be performed using the built-in camera without affecting the operation of the mirror mode/image display mode.

The black mask member 306 has an outer shape that overlaps with the IR light source 105 but does not overlap with the camera region 1021 of the liquid crystal optical element 102. The black mask member 306 has a first region 3061 and a second region 3062, and is configured so that the infrared transmittance of the first region 3061 is higher than the infrared transmittance of the second region 3062. The first region 3061 of the black mask member 306 is made of a visible light blocking/infrared transmitting material. This makes it easy to realize a structure that prevents the light emitted by the IR light source 105 from being noticed by the driver or passengers.

In this way, the inner mirror 300 according to the third embodiment is well suited to achieving good image capture using the built-in camera.

<Fourth embodiment>
11A and 11B are diagrams showing the configuration of an inner mirror 400 according to a fourth embodiment ((a) is a front view, and (b) is a vertical cross-sectional view).
The inner mirror 400 according to the fourth embodiment is configured as a liquid crystal anti-glare mirror with an image display function, and is installed at the upper end of the center of the front window in the vehicle width direction of a vehicle (not shown), such as a passenger car.

The inner mirror 400 has two operating modes: a mirror mode (image display function off) and an image display mode (image display function on). In addition, the mirror mode has two operating states: a non-anti-glare state (anti-glare function off) and an anti-glare state (anti-glare function on).

The inner mirror 400 includes a housing 101, a liquid crystal optical element 402, a liquid crystal display 403, an IR camera 404, an IR light source 105, a black mask member 406, a rear light sensor 107, an ambient light sensor 108, etc.

The inner mirror 400 corresponds to the inner mirror 100 according to the first embodiment (Fig. 1) in which the liquid crystal optical element 102, liquid crystal display 103, RGB-IR camera 104 and black mask member 106 are replaced with a liquid crystal optical element 402, a liquid crystal display 403, an IR camera 404 and a black mask member 406.

The liquid crystal optical element 402 corresponds to the liquid crystal optical element 102 of the first embodiment (FIG. 1) in which the camera region 1021 is not provided and the entire region is the main region 1022.

The liquid crystal display 403 corresponds to the liquid crystal display 103 of the first embodiment (FIG. 1) with a modified outer shape. The liquid crystal display 403 is disposed on the rear side of the liquid crystal optical element 402. The liquid crystal display 403 has an outer shape that corresponds to the area of the liquid crystal optical element 402 in the viewing direction X of the inner mirror 400 excluding the areas corresponding to the IR camera 404 and the IR light source 105.

The IR camera 404 is disposed on the rear side of the liquid crystal optical element 402. The IR camera 404 is a camera capable of capturing infrared images, and receives light incident through the liquid crystal optical element 402. For example, the IR camera 404 has a group of pixels for capturing infrared images, and an IR image signal can be obtained by a downstream image processing circuit or the like using the signal of the group of pixels for capturing infrared images.

The IR camera 404 is used to capture infrared images of the driver and passengers inside the vehicle cabin for the purpose of image recognition for driver/passenger monitoring by the DMS/OMS installed in the vehicle, for example.

When the DMS/OMS requests infrared photography for driver/passenger monitoring, the IR camera 404 turns on to obtain an IR image signal, and receives light incident from inside the vehicle through the liquid crystal optical element 402 to capture an infrared image.

The black mask member 406 is disposed between the liquid crystal optical element 402 and the IR light source 105. The black mask member 406 has an outer shape that overlaps at least the IR light source 105 in the viewing direction X of the inner mirror 400 and does not overlap the liquid crystal display 403.

For example, the black mask member 406 has an outer shape that overlaps with the IR camera 404 and the IR light source 105 in the viewing direction X of the inner mirror 400, but does not overlap with the liquid crystal display 403. The black mask member 406 is made of a visible light blocking/infrared transmitting material (such as the "NIR (infrared) filter" product by Nitto Plastics Corporation/CLAREX).

In the fourth embodiment, as in the first embodiment, at least a portion of the light source of the backlight 103k (FIG. 3) of the liquid crystal display 403 may be a light source capable of emitting infrared light. This allows the backlight 103k of the liquid crystal display 403 to also function as the IR light source 105, eliminating the need to provide the IR light source 105.

Also, if the IR light source 105 is not provided, the liquid crystal display 403 may have an outer shape corresponding to the area of the liquid crystal optical element 402 excluding the area corresponding to the IR camera 404 in the viewing direction X of the inner mirror 400. In this case, the outer shape of the liquid crystal display 403 is larger by the area corresponding to the IR light source 105 in the viewing direction X of the inner mirror 400.

FIG. 12 is a diagram showing the functional configuration of an inner mirror 400 according to the fourth embodiment.
The inner mirror 400 has an automatic anti-glare control unit 111, a monitoring system control unit 112, a camera linkage control unit 113, a display control unit 114, and the like.

The control operations of the automatic anti-glare control unit 111 and the display control unit 114 in the fourth embodiment are the same as those in the first embodiment, except that the camera area 1021 and the main area 1022 of the liquid crystal optical element 102 are replaced with the liquid crystal optical element 402.

The IR camera 404 and the IR light source 105 are connected to the monitoring system control unit 112. The liquid crystal optical element 402, the automatic anti-glare control unit 111, and the monitoring system control unit 112 are connected to the camera linkage control unit 113.

The monitoring system control unit 112 controls the IR camera 404 and the IR light source 105 for driver/passenger monitoring in response to instructions from the DMS/OMS. When the DMS/OMS requests infrared photography by the IR camera 404 (photography for driver/passenger monitoring), the monitoring system control unit 112 turns on the IR camera 404 to obtain an IR image signal and turns on the IR light source 105. At this time, for example, the IR light source 105 is driven intermittently in conjunction with a synchronization signal from the IR camera 404.

It is also possible for the monitoring system control unit 112 to instruct the camera linkage control unit 113 to transition the liquid crystal optical element 402 to a transmissive state (or a reflecting mirror state), and for the camera linkage control unit 113 to transition the liquid crystal optical element 402 to a transmissive state (or a reflecting mirror state) based on the instruction of the monitoring system control unit 112.

Here, we will explain the operation of the inner mirror 400 in mirror mode (non-anti-glare state/anti-glare state) and in image display mode.

[Operation in mirror mode (non-anti-glare state/anti-glare state)]
The liquid crystal display 403 is turned off by the display control unit 114. The automatic anti-glare control unit 111 determines whether or not a transition from a non-anti-glare state to an anti-glare state/a transition from the anti-glare state to the non-anti-glare state is required.

When the automatic anti-glare control unit 111 determines that it is not necessary to transition from a non-anti-glare state to an anti-glare state, the automatic anti-glare control unit 111 sets the liquid crystal optical element 402 to a reflective mirror state (visible light reflectance: high). This changes the operating mode of the inner mirror 400 to mirror mode and non-anti-glare state, and a reflected image in the non-anti-glare state appears on the visible surface of the inner mirror 400. Also, when the automatic anti-glare control unit 111 determines that it is necessary to transition from a non-anti-glare state to an anti-glare state, the automatic anti-glare control unit 111 sets the liquid crystal optical element 402 to a transmissive state (visible light reflectance: low). This changes the operating mode of the inner mirror 400 to mirror mode and anti-glare state, and a reflected image in the anti-glare state appears on the visible surface of the inner mirror 400.

On the other hand, if the automatic anti-glare control unit 111 determines that it is not necessary to transition from the anti-glare state to the non-anti-glare state, the automatic anti-glare control unit 111 sets the liquid crystal optical element 402 to a transmitting state (visible light reflectance: low). As a result, the operating mode of the inner mirror 400 becomes mirror mode and anti-glare state, and a reflected image in the anti-glare state appears on the visible surface of the inner mirror 400. Also, if the automatic anti-glare control unit 111 determines that it is necessary to transition from the anti-glare state to the non-anti-glare state, the automatic anti-glare control unit 111 sets the liquid crystal optical element 402 to a reflecting mirror state (visible light reflectance: high). As a result, the operating mode of the inner mirror 400 becomes mirror mode and non-anti-glare state, and a reflected image in the non-anti-glare state appears on the visible surface of the inner mirror 400.

[Image display mode operation]
The display control unit 114 turns on the liquid crystal display 403, and an image of the rear of the vehicle captured by the rear camera 116 is displayed on the liquid crystal display 403. The automatic anti-glare control unit 111 also turns the liquid crystal optical element 402 to a transmissive state (visible light transmittance: high). As a result, an image of the rear of the vehicle captured by the rear camera 116 and displayed on the liquid crystal display 403 appears on the visible surface of the inner mirror 400.

Next, we will explain the operation of the built-in camera of the inner mirror 400 when capturing infrared images. Note that the operation of the built-in camera when capturing infrared images is common to both mirror mode (non-anti-glare state/anti-glare state) and image display mode.

[Infrared photography using the built-in camera]
When the DMS/OMS requests infrared photography by the IR camera 404, the monitoring system control unit 112 turns on the IR light source 105 to emit infrared rays, and turns on the IR camera 404 to obtain an IR image signal and capture an infrared image. At this time, for example, the IR light source 105 is intermittently driven in conjunction with a synchronization signal of the IR camera 404. In this way, infrared photography is performed by the IR camera 404 for driver/passenger monitoring.

The inner mirror 400 according to the fourth embodiment as described above also provides the same effects as the inner mirror 100 according to the first embodiment. That is, the infrared transmittance of the liquid crystal optical element 402 is maintained high regardless of the operating state (reflecting mirror state/transmitting state) of the liquid crystal optical element 402. Therefore, when taking infrared images using the IR camera 404, there is no need to control the gain of the IR camera 404 or the light amount of the IR light source 105 according to the operating state of the liquid crystal optical element 402. This eliminates the need for complex control, simplifies control, and reduces power consumption.

In addition, the liquid crystal display 403 arranged on the rear side of the liquid crystal optical element 402 has an outer shape corresponding to the area of the liquid crystal optical element 402 excluding the areas corresponding to the IR camera 404 and the IR light source 105. This makes it easy to secure space for arranging the IR camera 404 and the IR light source 105 on the rear side of the liquid crystal optical element 402.

The black mask member 406 has an outer shape that overlaps at least the IR light source 105 but does not overlap the liquid crystal display 403, and is made of a visible light blocking, infrared light transmitting material. This makes it easy to realize a structure that prevents the light emitted by the IR light source 105 from being noticed by the driver or passengers.

Furthermore, by making some or all of the light sources of the backlight 103k of the liquid crystal display 403 emit infrared rays, the backlight 103k of the liquid crystal display 403 can also serve as the IR light source 105, making the IR light source 105 unnecessary. As a result, this contributes to improving the freedom of component placement inside the housing 101 and reducing costs by reducing the number of components.

In this case, by making the liquid crystal display 403 have an outer shape that corresponds to the area of the liquid crystal optical element 402 excluding the area that corresponds to the IR camera 404, the outer shape of the liquid crystal display 403 can be enlarged by the area that corresponds to the IR light source 105. This makes it possible to enlarge the display surface of the liquid crystal display 403, and as a result, to enlarge the image display area on the visible surface of the inner mirror 400.

In this way, the inner mirror 400 according to the fourth embodiment is well suited to achieving good image capture using the built-in camera.

Fifth Embodiment
13A and 13B are diagrams showing the configuration of an inner mirror 500 according to a fifth embodiment ((a) is a front view, and (b) is a vertical cross-sectional view).
The inner mirror 500 according to the fifth embodiment is configured as a liquid crystal anti-glare mirror, and is installed, for example, at the upper end of the center of the front window in the vehicle width direction of a vehicle (not shown) such as a passenger car.

The inner mirror 500 has two operating states: a non-anti-glare state (anti-glare function off) and an anti-glare state (anti-glare function on).

The inner mirror 500 includes a housing 101, a liquid crystal optical element 402, an IR camera 404, an IR light source 105, a black mask member 506, a rear light sensor 107, an ambient light sensor 108, etc.

The inner mirror 500 corresponds to the inner mirror 400 according to the fourth embodiment (FIG. 11) in which the liquid crystal display 103 is not provided and the black mask member 406 is replaced with a black mask member 506.

The black mask member 506 is disposed between the liquid crystal optical element 402 and the IR camera 404 and IR light source 105. The black mask member 506 has a third region 5061 that corresponds to the IR camera 404 and the IR light source 105 in the viewing direction X of the inner mirror 500, and a fourth region 5062 excluding the third region 5061.

Note that the third region 5061 of the black mask member 506 does not need to correspond to both the IR camera 404 and the IR light source 105, but only needs to correspond to at least the IR light source 105.

The black mask member 506 is configured so that the infrared transmittance of the third region 5061 is higher than the infrared transmittance of the fourth region 5062. For example, the third region 5061 of the black mask member 506 is made of a visible light blocking/infrared transmitting material (such as "NIR (infrared) filter" product by Nitto Plastics Corporation/CLAREX), and the fourth region 5062 of the black mask member 506 is made of a visible light blocking material.
The black mask member 506 may be entirely made of a visible light blocking, infrared transmitting material, so that the infrared transmittance is uniform.

FIG. 14 is a diagram showing the functional configuration of an inner mirror 500 according to the fifth embodiment.
The inner mirror 500 has an automatic anti-glare control unit 111, a monitoring system control unit 112, a camera linkage control unit 113, etc. The control operations of the automatic anti-glare control unit 111, the monitoring system control unit 112, and the camera linkage control unit 113 in the fifth embodiment are the same as the control operations in the fourth embodiment.

Here, we will explain the operation of the inner mirror 500 in the non-anti-glare state/anti-glare state. Note that the operation when capturing infrared images using the built-in camera of the inner mirror 500 is the same as the operation when capturing infrared images using the built-in camera of the inner mirror 400 according to the fourth embodiment.

[Operation in non-anti-glare state/anti-glare state]
In the automatic anti-glare control unit 111, it is determined whether or not a transition from a non-anti-glare state to an anti-glare state/a transition from an anti-glare state to a non-anti-glare state is required.

When the automatic anti-glare control unit 111 determines that it is not necessary to transition from a non-anti-glare state to an anti-glare state, the automatic anti-glare control unit 111 sets the liquid crystal optical element 402 to a reflective mirror state (visible light reflectance: high). This places the operating state of the inner mirror 500 in a non-anti-glare state, and a reflected image in the non-anti-glare state appears on the visible surface of the inner mirror 500. Also, when the automatic anti-glare control unit 111 determines that it is necessary to transition from a non-anti-glare state to an anti-glare state, the automatic anti-glare control unit 111 sets the liquid crystal optical element 402 to a transparent state (visible light reflectance: low). This places the operating state of the inner mirror 500 in an anti-glare state, and a reflected image in the anti-glare state appears on the visible surface of the inner mirror 500.

On the other hand, if the automatic anti-glare control unit 111 determines that it is not necessary to transition from the anti-glare state to the non-anti-glare state, the automatic anti-glare control unit 111 sets the liquid crystal optical element 402 to a transmitting state (visible light reflectance: low). This places the operating state of the inner mirror 500 in the anti-glare state, and a reflected image in the anti-glare state appears on the visible surface of the inner mirror 500. Also, if the automatic anti-glare control unit 111 determines that it is necessary to transition from the anti-glare state to the non-anti-glare state, the automatic anti-glare control unit 111 sets the liquid crystal optical element 402 to a reflective mirror state (visible light reflectance: high). This places the operating state of the inner mirror 500 in the non-anti-glare state, and a reflected image in the non-anti-glare state appears on the visible surface of the inner mirror 500.

The inner mirror 500 (liquid crystal anti-glare mirror (without image display function)) according to the fifth embodiment as described above also provides the same effect as the inner mirror 400 (liquid crystal anti-glare mirror with image display function) according to the fourth embodiment. That is, the infrared transmittance of the liquid crystal optical element 402 is maintained high regardless of the operating state (reflecting mirror state/transmitting state) of the liquid crystal optical element 402. Therefore, when taking infrared images using the IR camera 404, there is no need to control the gain of the IR camera 404 or the light amount of the IR light source 105 according to the operating state of the liquid crystal optical element 402. This eliminates the need for complex control, simplifies control, and reduces power consumption.

The black mask member 506, which is disposed between the liquid crystal optical element 402 and the IR light source 105, has a third region 5061 and a fourth region 5062, and is configured so that the infrared transmittance of the third region 5061 is higher than the infrared transmittance of the fourth region 5062. The third region 5061 of the black mask member 506 is made of a visible light blocking/infrared transmitting material. This makes it easy to realize a structure that prevents the light emitted by the IR light source 105 from being noticed by the driver or passengers.

In this way, the inner mirror 500 according to the fifth embodiment is well suited to achieving good image capture using the built-in camera.

The above describes embodiments of the present invention, but the present invention is not limited to these embodiments, and various modifications and variations are possible within the scope of the gist of the invention.

This application claims priority to Japanese Patent Application No. 2023-200818, filed on November 28, 2023, and incorporates all of the contents of that Japanese application by reference.

100 ... inner mirror, 101 ... housing, 102 ... liquid crystal optical element, 1021 ... camera area, 1022 ... main area, 103 ... liquid crystal display (liquid crystal display device), 103a ... polarizing plate (front side polarizing plate), 103b ... glass substrate, 103c ... RGB color filter (color filter), 103d ... ITO transparent electrode film, 103e ... alignment film, 103f ... liquid crystal layer, 103g ... alignment film, 103h ... TFT circuit and transparent electrode film, 103i ... glass substrate, 103j ... polarizing plate (rear side polarizing plate), 103k ... backlight, 104 ... RGB-IR camera (visible light / infrared camera; imaging unit), 105 ... IR light source (light emitting unit), 106 ... black mask member, 107 ... rear light sensor, 108 ... ambient light sensor, 111 ... automatic anti-glare control unit, 112 ... monitoring system camera control unit, 113...camera linkage control unit, 114...display control unit, 116...rear camera, 200...inner mirror, 202...liquid crystal optical element, 2021...camera area, 2022...main area, 203...liquid crystal display (liquid crystal display device), 2031...camera area (second camera area), 2032...main area (second main area), 300...inner mirror, 306...black mask member, 3061...first area, 3062...second area, 400...inner mirror, 402...liquid crystal optical element, 403...liquid crystal display (liquid crystal display device), 404...IR camera (infrared camera; imaging unit), 406...black mask member, 500...inner mirror, 506...black mask member, 5061...third area, 5062...fourth area, X...viewing direction of inner mirror

Claims (23)

A liquid crystal optical element that can be switched between a reflecting mirror state and a transmitting state;
an imaging section disposed on a rear side of the liquid crystal optical element and configured to receive light incident through the liquid crystal optical element and capture at least one of a visible light image and an infrared image;
An inner mirror comprising: the imaging unit is a camera capable of capturing at least a visible light image out of a visible light image and an infrared image,
The liquid crystal optical element has a camera area corresponding to the imaging unit in the viewing direction of the inner mirror and a main area excluding the camera area, and the camera area and the main area are configured to be able to independently control switching between a reflecting mirror state and a transmitting state.
2. The inner mirror according to claim 1 . The inner mirror further includes a liquid crystal display device that is disposed on a rear side of the main region of the liquid crystal optical element and has an outer shape corresponding to the main region of the liquid crystal optical element in the viewing direction.
3. The inner mirror according to claim 2. the imaging unit is a visible light/infrared camera capable of capturing a visible light image and an infrared image,
The inner mirror further includes a light emitting portion that is disposed on a rear side of the main region of the liquid crystal optical element and emits infrared rays,
the liquid crystal display device has an outer shape corresponding to a region of the liquid crystal optical element excluding a portion corresponding to the light emitting portion from the main region in the viewing direction;
4. The inner mirror according to claim 3. The inner mirror further includes a black mask member disposed between the main region of the liquid crystal optical element and the light emitting portion, the black mask member having an outer shape that overlaps with the light emitting portion in the viewing direction and does not overlap with the camera region of the liquid crystal optical element and the liquid crystal display device.
5. The inner mirror according to claim 4. The black mask member is made of a visible light blocking/infrared transmitting material.
6. The inner mirror according to claim 5. the imaging unit is a visible light/infrared camera capable of capturing a visible light image and an infrared image,
The liquid crystal display device has a backlight, and at least a part of the light source of the backlight is a light source capable of emitting infrared light.
4. The inner mirror according to claim 3. The inner mirror further includes a liquid crystal display device disposed on a rear side of the liquid crystal optical element,
the liquid crystal display device has a second camera region corresponding to the camera region of the liquid crystal optical element in the viewing direction, and a second main region excluding the second camera region, the second camera region having a higher visible light transmittance than the second main region,
the imaging unit receives light incident through the camera region of the liquid crystal optical element and the second camera region of the liquid crystal display device;
3. The inner mirror according to claim 2. The liquid crystal display device is configured so that a front polarizing plate, a color filter, a rear polarizing plate, and a backlight are not present in the second camera area.
9. The inner mirror according to claim 8. The liquid crystal display device is configured such that only a glass substrate is present in the second camera area.
9. The inner mirror according to claim 8. The liquid crystal display device is configured so that the second camera area is hollow.
9. The inner mirror according to claim 8. The imaging unit is a visible light/infrared camera capable of capturing a visible light image and an infrared image.
9. The inner mirror according to claim 8. the imaging unit is a visible light/infrared camera capable of capturing a visible light image and an infrared image,
The inner mirror is
a light emitting section that is disposed on a rear side of the main region of the liquid crystal optical element and emits infrared rays;
a black mask member disposed between the main region and the light-emitting portion of the liquid crystal optical element, the black mask member having an outer shape that overlaps the light-emitting portion in the viewing direction and does not overlap the camera region of the liquid crystal optical element,
3. The inner mirror according to claim 2. the black mask member has a first region corresponding to the light emitting portion in the viewing direction and a second region excluding the first region, and an infrared transmittance of the first region is higher than an infrared transmittance of the second region;
The inner mirror according to claim 13 . The first region of the black mask member is made of a visible light blocking/infrared transmitting material.
The inner mirror according to claim 14 . the imaging unit is an infrared camera capable of capturing an infrared image,
The inner mirror further includes a liquid crystal display device that is disposed on a rear side of the liquid crystal optical element and has an outer shape corresponding to a region of the liquid crystal optical element excluding a region corresponding to the imaging unit in a viewing direction of the inner mirror.
2. The inner mirror according to claim 1 . The inner mirror further includes a light emitting unit that is disposed on a rear side of the liquid crystal optical element and emits infrared light,
the liquid crystal display device has an outer shape corresponding to a region of the liquid crystal optical element excluding a region corresponding to the imaging unit and the light emitting unit in the viewing direction;
The inner mirror according to claim 16 . The inner mirror further includes a black mask member disposed between the liquid crystal optical element and the light-emitting unit, the black mask member having an outer shape that overlaps at least the light-emitting unit in the viewing direction and does not overlap the liquid crystal display device.
The inner mirror according to claim 17 . The black mask member is made of a visible light blocking/infrared transmitting material.
20. The inner mirror according to claim 18. The liquid crystal display device has a backlight, and at least a part of the light source of the backlight is a light source capable of emitting infrared light.
The inner mirror according to claim 16 . the imaging unit is an infrared camera capable of capturing an infrared image,
The inner mirror is
a light emitting unit that is disposed on a rear side of the liquid crystal optical element and emits infrared rays;
and a black mask member disposed between the liquid crystal optical element and the light emitting unit.
2. The inner mirror according to claim 1 . the black mask member has a third region corresponding to at least the light emitting portion in a viewing direction of the inner mirror, and a fourth region excluding the third region, and an infrared transmittance of the third region is higher than that of the fourth region;
22. The inner mirror according to claim 21. The third region of the black mask member is made of a visible light blocking/infrared transmitting material.
23. The inner mirror according to claim 22.

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