Display device and vehicle

Abstract

To provide a technique that can improve visibility of contents that are projected in front of a driver, which can contribute to sustainable development goal: 3 health and welfare for everyone.SOLUTION: A display device, which is loaded on a vehicle, comprises a light source, a display panel and a light-transmission / light-shielding switching part, where light from the light source is made incident to the display panel. Video light projected by the display panel is made incident to the light-transmission / light-shielding switching part. The light-transmission / light-shielding switching part can switch between a light-shielding state and a semi-light transmission state, in a portion or the whole in a region to which the video light is made incident thereof.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a display device and a vehicle.

Background Art

[0002] A virtual image display device or a head-up display (HUD) device is known that projects video light onto the windshield of an automobile or the like to form a virtual image, and displays traffic information such as route information and traffic jam information, and automobile information such as remaining fuel amount and coolant temperature.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is a problem of providing a technology capable of improving the visibility of content projected in front of the driver.

Means for Solving the Problems

[0005] According to the present invention, as an example, the following display device is provided. This display device is mounted on a vehicle, and includes a light source, a display panel onto which light from the light source is incident, and a transmissive light-shielding switching unit onto which video light projected by the display panel is incident. The transmissive light-shielding switching unit can switch between a light-shielding state and a semi-transmissive state in part or all of the region where the video light is incident.

Effects of the Invention

[0006] According to the present invention, the visibility of the content can be improved, and a more suitable display device can be realized. In addition, problems, configurations, and effects other than those described above will be clarified by the description of the embodiments for carrying out the following invention.

Brief Description of the Drawings

[0007]

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Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments are examples for explaining the present invention, and for the sake of clarity of the explanation, appropriate omissions and simplifications have been made. The present invention can also be implemented in various other forms. Unless otherwise particularly limited, each component may be singular or plural. In the drawings, the positions, sizes, shapes, ranges, etc. of the components shown may not represent the actual positions, sizes, shapes, ranges, etc. in order to facilitate the understanding of the invention. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, ranges, etc. disclosed in the drawings. When there are a plurality of components having the same or similar functions, they may be described with the same reference numeral and different subscripts. Also, when it is not necessary to distinguish these multiple components, the subscripts may be omitted in the description.

[0009] For the purpose of explanation, when explaining the processing by a program, the program, function, processing unit, etc. may be the main subject of the explanation. However, the main hardware for these is a processor, or a controller, device, computer, system, etc. composed of such a processor. The computer executes processing according to the program read onto the memory while appropriately using resources such as a memory and a communication interface by the processor. Thereby, a predetermined function, processing unit, etc. are realized. The processor is composed of, for example, semiconductor devices such as a CPU / MPU or a GPU. The processing is not limited to software program processing and can also be implemented by a dedicated circuit. FPGA, ASIC, CPLD, etc. are applicable to the dedicated circuit.

[0010] First, with reference to FIG. 1, an example of a vehicle equipped with a display device will be described. FIG. 1 is a schematic diagram showing a configuration example of a vehicle equipped with a display device or a virtual image display device. For the vehicle and the driver, in the horizontal direction x, it is the left-right direction, the lateral direction of the vehicle, or the width direction of the vehicle. In the vertical direction y, it is the up-down direction of the vehicle, the longitudinal direction. The horizontal direction z orthogonal to the lateral direction of the vehicle is the front-rear direction of the vehicle or the traveling direction of the vehicle. The display device may also be referred to as a virtual image display device. The following description will use the name of the display device.

[0011] The display device 1 acquires vehicle information 4 from cameras and various sensors installed in each part of the vehicle 2. The various sensors detect, for example, various events occurring in the vehicle 2, periodically detect values of various parameters related to the driving situation, or acquire information such as roads from the navigation device. The vehicle information 4 includes, for example, speed information, gear information, steering wheel steering angle information, lamp lighting information, external light information, distance information, infrared information, engine ON / OFF information, camera video information, acceleration gyro information, GPS (Global Positioning System) information, navigation information, vehicle-to-vehicle communication information, and road-to-vehicle communication information. The camera video information includes in-vehicle camera video information and out-vehicle camera video information. The GPS information includes, in addition to latitude and longitude, current time information, etc. Further, the vehicle information 4 includes input information from the driver.

[0012] Based on such vehicle information 4, the display device 1 projects / emits video light to the display area 5 of the windshield 3. Thereby, the display device 1 enables the driver of the vehicle 2 to visually recognize the display video. In the present embodiment, projecting video light to the display area 5 of the windshield 3 is described, but the projection unit that projects the video light may be a projection member such as a combiner.

[0013] The display device 1 is connected to the controller 100 of the vehicle 2 via an information transmission path, and the display device 1 and the controller 100 can communicate with each other. The controller 100 of the vehicle 2 is an ECU (Electronic Control Unit). The display device 1 and the controller 100 of the vehicle 2 communicate with each other via the information transmission path, for example, by CAN (Controller Area Network). Note that the display device 1 and the controller 100 of the vehicle 2 may communicate with each other via the information transmission path by in-vehicle Ethernet or the like.

[0014] Also, other connection forms may be adopted. For example, when transmitting all information including video information through one information transmission path, the connection between the controller 100 (the source of video information, etc.) on both sides of the vehicle 2 and the display device 1 (in other words, the connection form of the information transmission path) may be FPD-LinkIII, GMSL (Gigabit Multimedia Serial Link), etc.

[0015] The controller 100 controls the vehicle 2 based on data input and output, and with the configuration connected to the display device 1, an in-vehicle system is configured. The in-vehicle system is a system in which the controller 100 can control the vehicle 2 using the vehicle information 4.

[0016] Next, with reference to FIG. 2, an example of the configuration related to image display will be described. The display device 1 is provided, for example, on or inside the dashboard 70. The display device 1 projects video light toward the display area 5 of the windshield 3 described above. A transmissive light-shielding switching unit is provided in the display area 5 of the windshield 3. This transmissive light-shielding switching unit is a configuration used for controlling light transmission and light shielding, and is shown by hatching in the figure. Specific configuration examples of the transmissive light-shielding switching unit will be described in detail later. When the transmissive light-shielding switching unit shields light, the driver 9 of the vehicle can visually recognize a display video that does not overlap with the scenery. Also, when the transmissive light-shielding switching unit semi-transmits light, the driver 9 of the vehicle 2 can visually recognize a virtual image 8 corresponding to the display video superimposed on the scenery. Note that the transmissive light-shielding switching unit may be provided in the display device 1 or in the vehicle 2.

[0017] Next, with reference to FIGS. 3A and 3B, an example of the display when the transmissive light-shielding switching unit blocks light will be described. In this example, when the entire surface of the transmissive light-shielding switching unit 924a is in the light-blocking state, the background luminance of the video becomes low, and visibility can be obtained even when the video luminance is low. Therefore, for example, when the background of the video is black, dark blue, blue, etc., power saving during video display is achieved because the video luminance is low. Alternatively, since the video luminance is low, the energy generated during video display (in this example, thermal energy and light energy) is reduced. As a result, deterioration of the product is suppressed, and the product life can be extended. In addition, since external light (sunlight) is blocked by the transmissive light-shielding switching unit 924a, the external light does not enter the display panel of the display device. As a result, the temperature rise of the display panel is suppressed, and deterioration of the display panel is suppressed.

[0018] As shown in FIGS. 3A and 3B, as an example, the transmissive light-shielding switching unit 924a is provided over the entire lower part of the windshield 3 so as not to obstruct the driver's view. That is, the transmissive light-shielding switching unit 924a is provided across the lower part of the windshield 3 from left to right. However, it is sufficient that the transmissive light-shielding switching unit is provided in the portion used for video display. That is, the transmissive light-shielding switching unit may be provided in the display area 5 or according to the customer's needs.

[0019] Next, with reference to FIGS. 4A and 4B, an example of the display when the transmissive light-shielding switching unit transmits light semi-transmissively will be described. In this example, when the entire surface of the transmissive light-shielding switching unit 924a is in the semi-transmissive state, the driver of the vehicle can visually recognize the front through the transmissive light-shielding switching unit 924a, so the driving safety is enhanced. Note that the transmissive light-shielding switching unit 924a can be provided in the same manner as described in FIGS. 3A and 3B above.

[0020] Next, with reference to FIGS. 5A and 5B, an example of the display when the transmissive light-shielding switching unit shields only the light related to the display area will be described. In this example, among the entire surface of the transmissive light-shielding switching unit 924a, only the entire area related to the display area 5 is in the light-shielded state, and the other parts are in the semi-transmissive state. Therefore, it is possible to suppress the incidence of external light (sunlight) on the display panel, and it is possible to suppress the temperature rise and light deterioration of the display panel. Also, the forward visibility is obtained by the semi-transmissive part, and the driving safety is enhanced.

[0021] Note that the transmissive light-shielding switching unit 924a can adjust the area in the light-shielded state within the display area 5 according to the content of the video to be displayed. For example, in addition to the display part of the content, the transmissive light-shielding switching unit 924a can also make the part that becomes the background of the video (for example, the contour part of the content) in the light-shielded state, so that good visibility can be obtained even when the video brightness is low. On the other hand, the transmissive light-shielding switching unit 924a may make only the part that overlaps the content displayed within the display area 5 in the light-shielded state, and the other parts in the semi-transmissive state.

[0022] Next, with reference to FIGS. 6A and 6B, an example of the shape of the transmissive light-shielding switching unit will be described. As an example, the transmissive light-shielding switching unit 924b can be provided at the lower part of the windshield 3 so that the length in the left-right direction becomes shorter as it goes from the lower part to the upper part of the windshield 3. And as shown in the figure, the transmissive light-shielding switching unit 924b makes the part that overlaps the content and the substantially trapezoidal or trapezoidal part (in this example, the entire display area 5) whose length in the left-right direction becomes shorter as it goes from the lower part to the upper part of the surrounding part in the light-shielded state, and the display device 1 projects the video light for displaying the content having a sense of depth, so that a display that makes it easy for the driver of the vehicle to feel the sense of depth is realized.

[0023] More specifically, the transmissive light-shielding switching unit 924b has a shape that is longer in the left-right direction or width direction of the vehicle than the region where the image light is incident, and has a substantially trapezoidal shape or trapezoidal shape whose length in the left-right direction becomes shorter as it goes from the lower part to the upper part of the vehicle. When this is the case, by making the size of the content drawn on the display panel, the font size, or the left-right dimension of the vehicle within the same content smaller as it goes from the lower part to the upper part of the vehicle, the driver can more easily feel a sense of perspective in the display image. Note that the display that makes it easier to feel a sense of perspective is not limited to the case where the transmissive light-shielding switching unit 924b is provided in the display area 5. For example, it may be the case where black ceramics printing or the like is provided in the display area 5 as a light-shielding part. When the light-shielding part provided in the display area 5 has a shape that is longer in the left-right direction of the vehicle than the region where the image light is incident, and has a substantially trapezoidal shape or trapezoidal shape whose length in the left-right direction becomes shorter as it goes from the lower part to the upper part of the vehicle, by making the size of the content drawn on the display panel, the font size, or the left-right dimension of the vehicle within the same content smaller as it goes from the lower part to the upper part of the vehicle, the driver can more easily feel a sense of perspective in the display image.

[0024] In the figure, the transmissive light-shielding switching unit 924b has a substantially trapezoidal shape or trapezoidal shape whose length in the left-right direction becomes shorter as it goes from the lower part to the upper part of the vehicle. However, only the same substantially trapezoidal part as the above description (that is, the entire display area 5) becomes the light-shielded state, and the other parts become the semi-transmissive state, and by projecting the image light for displaying the content having a sense of perspective, the same effect can be obtained. Therefore, the shape of the transmissive light-shielding switching unit may be changed as appropriate. The transmissive light-shielding switching unit may be provided, for example, at the lower part of the windshield 3 and may have a shape that is longer in the left-right direction of the vehicle than the display area 5 where the display panel 11 projects the image light. Then, this transmissive light-shielding switching unit may be in the light-shielded state over the entire display area 5 and in the semi-transmissive state in the other parts.

[0025] Next, with reference to FIGS. 7 to 10, a configuration example of the transmissive light-shielding switching unit will be described in more detail. The transmissive light-shielding switching unit (924a, 924b) includes liquid crystal and a dye or pigment, and is configured to orient the dye or pigment in a predetermined direction by the liquid crystal.

[0026] Here, the transmissive light-shielding switching unit (924a, 924b) is preferably normally black. Normally black is in a light-shielded state when no voltage is applied. In this case, when the vehicle is not in use, the incidence of external light SL, for example, sunlight, on the display panel can be suppressed, and product deterioration can be suppressed. Specifically, when the engine of the vehicle is OFF (when the ignition switch is OFF), or when an electrically driven vehicle is not in use (when the power switch for enabling the electric vehicle to run is OFF), etc., the incidence of external light SL can be suppressed.

[0027] The transmissive light-shielding switching unit (924a, 924b) is in a sheet shape and may be provided, for example, on the surface of the driver's seat side (inside of the windshield 3) of the windshield 3. Further, the transmissive light-shielding switching unit (924a, 924b) may be included in the interlayer film of the windshield 3. Also, a half mirror, a reflective polarizing film, etc. may be provided on the incident surface (the surface on which light is incident) of the transmissive light-shielding switching unit (924a, 924b). The half mirror, the reflective polarizing film, etc. may be provided on the incident surface on which the video light IL is incident, or may be provided on the incident surface on which the external light SL is incident. The video light IL incident on the transmissive light-shielding switching unit (924a, 924b) including a half mirror, a reflective film, etc. is efficiently reflected by the half mirror, the reflective film, etc., so that power saving during video display is realized. As a result, deterioration of the product due to energy (in this example, thermal energy and light energy) generated during video display is suppressed, and the product life can be extended. On the other hand, the external light SL incident on the transmissive light-shielding switching unit (924a, 924b) is blocked by a half mirror, a reflective polarizing film, etc., so that external light does not enter the display panel of the display device. As a result, the temperature rise of the display panel is suppressed, and deterioration of the display panel is suppressed.

[0028] Referring to FIGS. 7A and 7B, an example of the light-shielding state of the transmissive light-shielding switching unit will be described. In this example, the display device projects image light IL toward the transmissive light-shielding switching unit (924a, 924b), and the image light IL is reflected by the transmissive light-shielding switching unit (924a, 924b) and travels toward the driver. The driver can visually recognize a virtual image corresponding to the display image (i.e., video display without superimposing scenery) on the transmissive light-shielding switching unit (924a, 924b) in the light-shielding state. Further, the external light SL incident on the transmissive light-shielding switching unit (924a, 924b) is absorbed (or reflected) at least by the transmissive light-shielding switching unit (924a, 924b) in the light-shielding state and does not enter the vehicle interior side from the transmissive light-shielding switching unit (924a, 924b). Here, as shown in FIG. 7B, in the area where the transmissive light-shielding switching unit (924a, 924b) is in the light-shielding state, the dyes or pigments contained in the transmissive light-shielding switching unit (924a, 924b) are randomly oriented in the xy plane or the xyz space. In other words, in the portion in the light-shielding state, the dyes or pigments are not oriented in a specific direction. In the same figure, the dyes or pigments are denoted by reference numeral D.

[0029] Referring to FIGS. 8A and 8B, an example of the semi-transmissive state of the transmissive light-shielding switching unit will be described. As shown in the same figure, in this example, in the area where the transmissive light-shielding switching unit (924a, 924b) is in the semi-transmissive state, the dyes or pigments in the transmissive light-shielding switching unit (924a, 924b) are oriented in the x-axis direction corresponding to the vehicle width direction. In the same figure, the dyes or pigments are denoted by reference numeral D. Then, the polarized component of the image light IL (the P-polarized component in this example) is incident on the transmissive light-shielding switching unit (924a, 924b), and a part of the image light IL is Fresnel reflected at the incident surface and travels toward the driver. Further, the polarized component of the external light SL (the P-polarized component in this example) passes through the transmissive light-shielding switching unit (924a, 924b). As a result, the display device projects the P-polarized image light IL, and the driver can visually recognize a virtual image corresponding to the display image superimposed on the scenery.

[0030] Since the transmissive light-shielding switching units (924a, 924b) are provided in a partial region of the windshield 3, it is conceivable that external light SL enters the vehicle interior from the windshield 3 without passing through the transmissive light-shielding switching units (924a, 924b). Here, even when the driver wears, for example, polarized sunglasses (in this example, sunglasses that block S polarization) as a countermeasure against the external light SL that directly enters the vehicle interior, the polarization component of the video light IL (in this example, the component of P polarization) and the polarization component of the external light SL (in this example, the component of P polarization) pass through the polarized sunglasses, so the driver can visually recognize the virtual image corresponding to the display image superimposed on the scenery.

[0031] As shown in the same figure, even when the display device projects the video light IL of S polarization onto the transmissive light-shielding switching units (924a, 924b) in which the dye or pigment is oriented in the x-axis direction, the video light IL is Fresnel reflected at the incident surface of the transmissive light-shielding switching units (924a, 924b), and the driver can visually recognize the virtual image corresponding to the display image.

[0032] Also, when the video light IL is of S polarization, the component that is not Fresnel reflected at the incident surface of the transmissive light-shielding switching units (924a, 924b), that is, the video light SL that enters the interior of the transmissive light-shielding switching units (924a, 924b) is absorbed by the dye or pigment oriented in the x-axis direction. Thereby, the double image generated by the Fresnel reflection of the video light IL at the back surface (the vehicle exterior side surface) of the windshield 3 is suppressed.

[0033] Note that the transmissive light-shielding switching units (924a, 924b) in which the dye or pigment D is oriented in the x-axis direction have been described with reference to the same figure. However, in the transmissive light-shielding switching units (924a, 924b), the dye or pigment D may be oriented in the y-axis direction. Similarly in this case, the video light IL is Fresnel reflected at the incident surface of the transmissive light-shielding switching units (924a, 924b) regardless of the polarization direction of the video light, and the driver can visually recognize the virtual image corresponding to the display image.

[0034] Also, when the image light IL is P-polarized, similar to the above description, the image light IL that enters the inside of the transmission light-shielding switching unit (924a, 924b) is absorbed by the dye or pigment D, thereby suppressing the generation of double images.

[0035] With reference to FIGS. 9A and 9B, an example of the semi-transmissive state of the transmission light-shielding switching unit will be described. In this example, the alignment direction of the transmission light-shielding switching unit (924a, 924b) is different from the above. That is, in the area where the transmission light-shielding switching unit (924a, 924b) is in a semi-transmissive state, the dye or pigment in the transmission light-shielding switching unit (924a, 924b) is aligned along the xy plane so as to form an angle of approximately 45° with respect to the x-axis direction (corresponding to the vehicle width direction) and the y-axis direction (corresponding to the vertical direction of the vehicle). In the figure, the dye or pigment is denoted by the reference numeral D. In this example, the image light IL having a polarization direction parallel to the alignment direction of the dye or pigment D is projected, and the image light IL is incident on the transmission light-shielding switching unit (924a, 924b). A part of the image light IL is Fresnel reflected at the incident surface and travels toward the driver. Then, the driver can visually recognize a virtual image corresponding to the display image superimposed on the scenery. Also, for the external light SL, the polarization component orthogonal to the alignment direction of the dye or pigment D passes through the transmission light-shielding switching unit (924a, 924b).

[0036] Since the reflected light IL and the external light SL that passes through the transmissive light-shielding switching units (924a, 924b) have polarization components inclined at approximately 45° with respect to the x-axis, even when the driver wears polarized sunglasses as a countermeasure against the external light directly entering the vehicle interior, the driver can visually recognize the virtual image corresponding to the scenery and the display image. Here, when wearing polarized sunglasses, the brightness of the external light SL (including the external light SL that passes through the transmissive light-shielding switching units (924a, 924b)) passing through the windshield 3 and the brightness of the reflected light IL are each reduced to about half, so there is no sense of discomfort when wearing sunglasses. In other words, since the darkness felt by the driver when wearing polarized sunglasses is the same for the scenery seen through the windshield 3 (including the scenery seen through the transmissive light-shielding switching units (924a, 924b)) and the virtual image 8, the contrast within the driver's field of view remains constant before and after wearing polarized sunglasses, and there is no sense of discomfort when wearing polarized sunglasses.

[0037] Also, the component that is not Fresnel-reflected at the incident surface of the transmissive light-shielding switching units (924a, 924b), that is, the reflected light SL that enters the interior of the transmissive light-shielding switching units (924a, 924b), is absorbed by the aligned dye or pigment. Thereby, the double image generated by the Fresnel reflection of the reflected light IL on the back surface (the vehicle exterior side surface) of the windshield 3 is suppressed.

[0038] With reference to FIGS. 10A and 10B, an example of the semi-transmissive state of the transmissive light-shielding switching unit will be described. In this example, the alignment direction of the transmissive light-shielding switching units (924a, 924b) is different from the above. That is, in the area where the transmissive light-shielding switching units (924a, 924b) are in the semi-transmissive state, the dye or pigment in the transmissive light-shielding switching units (924a, 924b) is aligned along the z-axis direction, which is the direction orthogonal to the xy plane and corresponds to the longitudinal direction of the vehicle. In the figure, the dye or pigment is indicated by the reference numeral D. In this example, the transmittance increases as the occupancy rate of the dye or pigment D in the xy plane decreases, thereby making it easier to see the scenery seen through the transmissive light-shielding switching units (924a, 924b). The external light SL passes through the transmissive light-shielding switching units (924a, 924b) while reducing the light amount while remaining randomly polarized.

[0039] The image light IL is projected onto the transmission / light-shielding switching units (924a, 924b), and a part of the image light IL is Fresnel-reflected on the incident surface of the transmission / light-shielding switching units (924a, 924b) and heads towards the driver. Then, the driver can visually recognize a virtual image corresponding to the display image superimposed on the scenery. The polarization direction of the image light IL is arbitrary and may be random polarization, but by projecting the S-polarized image light IL, a high reflectance can be obtained at the interface of the transmission / light-shielding switching units (924a, 924b), and the image can be brightened. However, since a part of the image light IL passes through the transmission / light-shielding switching units (924a, 924b) and is reflected on the back surface (outside of the vehicle) of the windshield 3, a double image is formed. Therefore, for example, it is desirable to take measures against double images with a wedge glass.

[0040] Similar to the above description, even when the driver wears polarized sunglasses as a countermeasure against external light directly entering the vehicle interior, the driver can visually recognize the virtual image corresponding to the display image, except when the image light IL is S-polarized. Here, when the image light IL is random polarization, circular polarization, or linearly polarized light that is approximately 45° with respect to the x-axis and y-axis, the brightness of the external light SL passing through the windshield 3 (including the external light SL passing through the transmission / light-shielding switching units (924a, 924b)) and the brightness of the image light IL are each reduced to about half by wearing polarized sunglasses. Therefore, there is no sense of discomfort when wearing sunglasses. In other words, since the darkness felt by the driver when wearing polarized sunglasses is the same for the scenery seen through the windshield 3 (including the scenery seen through the transmission / light-shielding switching units (924a, 924b)) and the virtual image 8, the contrast within the driver's field of view remains constant before and after wearing polarized sunglasses, and there is no sense of discomfort when wearing polarized sunglasses. By arranging the transmission / light-shielding switching unit or the light-shielding unit, the double image generated by the Fresnel reflection of the image light on the back surface (the outer surface of the vehicle) of the windshield can be suppressed, the visibility of the content can be improved, and a more suitable display device can be realized.

[0041] Next, with reference to FIG. 11, an example of the configuration of the vehicle will be described. Note that the vehicle can be provided with a transmissive light-shielding switching unit. In the configuration example of FIG. 11, the vehicle is provided with a transmissive light-shielding switching unit (924a or 924b), and the controller or control device of the vehicle controls the transmissive light-shielding switching unit (924a, 924b).

[0042] As shown in FIG. 11, the vehicle includes a controller 100 or a control device. The controller 100 or the control device (which may be referred to as the controller 100) acquires vehicle information using devices such as connected cameras and various sensors. Note that regarding the various devices in FIG. 11, deletion, addition of other types of devices, or replacement with other types of devices can be performed as appropriate. Also, as an example, the controller 100 of vehicle 2 may have a function related to the control of the display device 1.

[0043] The vehicle speed sensor 901 detects the speed of vehicle 2 and is used to generate speed information as the detection result. The shift position sensor 902 detects the current gear and is used to generate gear information as the detection result. The steering wheel steering angle sensor 903 detects the current steering wheel steering angle and is used to generate steering wheel steering angle information as the detection result. The headlight sensor 904 detects the ON / OFF of the headlights and is used to generate lamp lighting information as the detection result.

[0044] The illuminance sensor 905 and the chromaticity sensor 906 detect the external light of vehicle 2 and are used to generate external light information as the detection result. The distance measuring sensor 907 detects the distance between vehicle 2 and an external object or the distance between external objects and is used to generate distance information as the detection result. The infrared sensor 908 detects the presence or absence and distance of an object in the vicinity of vehicle 2 and is used to generate infrared information as the detection result. The engine start sensor 909 detects the ON / OFF of the engine and is used to generate ON / OFF information as the detection result.

[0045] The acceleration sensor 912 and the gyro sensor 913 detect the acceleration and angular velocity of the vehicle 2 and are used to generate acceleration-gyro information representing the attitude and behavior of the vehicle 2.

[0046] The temperature sensor 914 detects the temperature inside and outside the vehicle and is used to generate temperature information as the detection result.

[0047] The vehicle-road communication wireless transceiver 915 generates vehicle-road communication information through vehicle-road communication between the vehicle 2 and roads, signs, signals, etc. The vehicle-vehicle communication wireless transceiver 916 generates vehicle-vehicle communication information through vehicle-vehicle communication between the vehicle 2 and other surrounding vehicles. The wired / wireless communication unit 917 for vehicle-to-mobile communication is a device that acquires information by wired or wireless communication from a device (e.g., a WiFi device) connected to the LTE (Long Term Evolution) network. The controller 100 or the control device can acquire the information transmitted and received on the LTE network via the wired / wireless communication unit 917 for vehicle-to-mobile communication.

[0048] The in-vehicle camera 919 and the out-vehicle camera 920 capture images inside and outside the vehicle and are used to generate in-vehicle camera video information and out-vehicle camera video information. Specifically, the in-vehicle camera 919 is, for example, a camera for DMS (Driver Monitoring System) that captures the driver's posture, eye position, movement, etc. In this case, by analyzing the captured video, the driver's fatigue status, line-of-sight position, etc. can be grasped.

[0049] On the other hand, the out-vehicle camera 920 captures the surrounding situation in front of and behind the vehicle 2, for example. In this case, by analyzing the captured video, it becomes possible to grasp the presence or absence of obstacles such as other vehicles and people existing in the vicinity, road surface conditions such as buildings, terrain, rain, snow accumulation, freezing, unevenness, etc., and road signs. Also, the out-vehicle camera 920 includes, for example, a drive recorder that records the situation during driving in video.

[0050] The GPS receiver 921 generates GPS information obtained by receiving GPS signals from GPS satellites. For example, the current time, latitude, and longitude can be acquired by the GPS receiver 921. The VICS (Vehicle Information and Communication System, registered trademark) receiver 922 generates VICS information obtained by receiving VICS signals. The GPS receiver 921 and the VICS receiver 922 may be provided as part of the navigation system.

[0051] The voice input device 918 receives the driver's voice, and the voice input device 918 is used to generate voice information. The driver can input the operation content through the voice input device 918 by uttering a voice. The vehicle operation switch 911 is used to generate the driver's operation information for the steering switch and the like.

[0052] In addition, the video generation unit 910 generates video information based on the vehicle information 4 acquired by the controller 100 of the vehicle 2.

[0053] The raindrop sensor 923 detects raindrops adhering to the windshield 3 of the vehicle 2, and the controller 100 acquires information on the raindrops as the detection result. The transmission / light-shielding switching unit (924a, 924b) is a configuration used for controlling the transmission and light shielding of light as described above. As an example, the controller 100 can control the operation of the transmission / light-shielding switching unit (924a, 924b) based on the control process described later.

[0054] Next, a configuration example of the display device will be described with reference to FIGS. 12 and 13. Note that the display device 1 can include a transmission / light-shielding switching unit. In the configuration examples of FIGS. 12 and 13, the display device includes the transmission / light-shielding switching unit (924a or 924b), and the processor of the display device (in these examples, the MCU 1010) controls the transmission / light-shielding switching unit (924a, 924b).

[0055] In FIG. 12, the display device 1 includes, for example, a microcontroller (MCU) 1010 mounted on a wiring board or the like, a non-volatile memory 1011, a volatile memory 1012, a video processing unit 1013, a communication processing unit 1014, a display driver 1021, a light source driver 1022, and the like. In the example of FIG. 12, the communication processing unit 1014 transmits and receives main vehicle information 4, and may also function as a control unit of the display device 1. The video processing unit 1013 receives video information or video data generated by the controller 100 of the vehicle 2 in the video generation unit 910. Also, the video processing unit 1013 does not generate video, but processes the video received from the vehicle 2. The processing by the video processing unit 1013 includes processing such as distortion correction and conversion (for example, decoding) of the video.

[0056] In FIG. 13, similar to the case of FIG. 12, it includes a microcontroller (MCU) 1010 mounted on a wiring board, a non-volatile memory 1011, a volatile memory 1012, a communication processing unit 1014, a video processing unit 1015, a display driver 1021, a light source driver 1022, and the like. However, in the example of FIG. 13, the video processing unit 1015 has the function of the video generation unit 910, and instead of receiving video information, generates video information using the information to be acquired (for example, vehicle information 4). Also, the video processing unit 1015 can perform processing such as distortion correction and conversion on the generated video information.

[0057] As is widely known, the MCU 1010 includes a processor such as a CPU (Central Processing Unit), in addition to a memory, and has various peripheral functions. Therefore, each block except this MCU 1010 may be appropriately mounted within the MCU 1010. Also, the display device 1 is not limited to being mounted using the MCU 1010, and may be mounted using an ECU, or may be mounted using other semiconductor devices. The control structure as shown in FIGS. 12 and 13 may be, for example, a control unit mounted inside the housing of the display device 1, or a control unit mounted outside the housing.

[0058] In the example of FIG. 12, the MCU 1010 receives video information via the communication processing unit 1014, for example, via FPD-Link III or GMSL. The MCU 1010 may perform processes such as distortion correction and conversion on the received video information as the function of the video processing unit 1013. The video processing unit 1013 is mainly realized by the CPU of the MCU 1010 reading and executing a program stored in the non-volatile memory 1011 or the volatile memory 1012.

[0059] In the example of FIG. 13, the MCU 1010 receives vehicle information 4 via the communication processing unit 1014, for example, via CAN or in-vehicle Ethernet. The MCU 1010 can generate video data for the video display unit 200 based on the vehicle information 4 and the like as the function of the video processing unit 1015. The video processing unit 1015 is mainly realized by the CPU of the MCU 1010 reading and executing a program stored in the non-volatile memory 1011 or the volatile memory 1012.

[0060] That is, the video processing units (1013, 1015) process video data that determines the display content of the display video projected onto the display area 5 in FIG. 1 and the like based on the information to be acquired. The display driver 1021 drives each display element (pixel) included in the display panel 11 based on the video data. Thereby, the image forming unit 10 or the image forming unit 10 creates and displays a video for projection onto the display area 5 based on the video data.

[0061] In the distortion correction, specifically, as shown in FIG. 1, the distortion of the video caused by the curvature of the windshield 3 when the video from the display device 1 is projected onto the display area 5 is corrected. Then, the display driver 1021 drives each display element (pixel) included in the display panel 11 based on the corrected video data. Thereby, the image forming unit 10 or the image forming unit 10 creates and displays a video for projection onto the display area 5 based on the corrected video data.

[0062] In addition, the light source driving unit 1022 can perform light source adjustment, and the light source driving unit 1022 adjusts the luminance of the light source 20 in the image forming unit PGU1 or the image forming unit PGU1. Based on the vehicle information 4 received via the communication processing unit 1014, the light source 20 is controlled using the light source driving unit 1022, which is a driver used for driving the light source.

[0063] In addition, the display device 1 may protect the display panel 11 based on external light information from the illuminance sensor 905 or the like. That is, in order to prevent the display panel 11 from being burned by sunlight hitting the display panel 11, the display device 1 may perform an operation to protect the panel from sunlight according to the value of the illuminance sensor 905. More specifically, when the intensity of the external light or sunlight acquired by the illuminance sensor 905 is strong and there is a risk of the display panel 11 being burned out, the luminance of the light source 20 in the image forming unit PGU1 is reduced, and the amount of light from the light source 20 incident on the display panel 11 is suppressed, thereby suppressing the temperature rise of the display panel 11.

[0064] The non-volatile memory 1011 mainly stores in advance programs executed by the CPU in the MCU1010, setting parameters used in the processing of each part in the MCU1010, specified audio data, video data, and the like.

[0065] The volatile memory 1012 mainly stores the acquired information and various data used in the processing process of each part in the MCU1010 as appropriate. The communication processing unit 1014 is a device equipped with a communication interface and communicates with the outside of the display device 1 based on a communication protocol according to CAN, LIN, or the like. The communication processing unit 1014 may be integrated with the vehicle information acquisition unit.

[0066] Each part of the control device in FIGS. 12 and 13 may be implemented by a dedicated circuit such as an FPGA (Field Programmable Gate Array) as appropriate. In the present embodiment, the configuration has a non-volatile memory 1011 and a volatile memory 1012, but the above processing may be made to function by a single memory. FIG. 12 shows that the video processing unit of the display device creates a video based on the information acquired from the vehicle, and FIG. 13 shows that the video is acquired from the vehicle.

[0067] Next, the image forming unit will be specifically described. The image forming unit PGU1 displays a video based on video data and projects the video light of the displayed video. The image forming unit PGU1 includes a light source 20 and a display panel 11 such as a liquid crystal panel LCD (Liquid Crystal Display) having a video display element.

[0068] The image forming unit PGU1 projects the video light of the video formed on the display panel 11 using the light emitted from the light source 20 (in other words, the light source light). The light source 20 typically includes an LED (Light Emitting Diode).

[0069] The display panel 11 creates a video based on the video data and displays it on the display screen of the display panel 11. The video data of the present embodiment will be described as the video data input from the video processing units (1013, 1015). The display panel 11 forms a video for projection onto the display area 5 by modulating the transmittance of the light from the light source 20 for each pixel according to the video data, and projects it as video light (in other words, projection light).

[0070] Further, the display panel 11 may be a screen plate having a diffusion function, not limited to a liquid crystal panel. As means for projecting an image for forming a real image onto the screen plate having a diffusion function, means for projecting an image of a DMD (Digital Micromirror Device) or a liquid crystal panel in combination with a projection lens, or means using a Micro Electro Mechanical Systems may be used.

[0071] The light source 20 is configured using, for example, a semiconductor light source element, generates predetermined light source light, and supplies it to the display panel 11. The light source 20 functions as a backlight source for the display panel 11. Typically, an LED (Light Emitting Diode) element is used as the semiconductor light source element. The light source 20 may have a configuration in which a plurality of light sources are arranged.

[0072] The backlight unit is configured using the light source 20 or the like. Specific configuration examples of the backlight unit will be described later.

[0073] The image light emitted from the display panel 11, in other words, the projection light, travels toward the display area 5 of the windshield 3. Therefore, the user of the display device 1 can visually recognize the image light as a virtual image, for example. As a result, the driver can visually recognize, for example, the image light projected onto the display area 5 as a virtual image in front of the transparent windshield 3, superimposed on the scenery outside the vehicle (for example, roads, buildings, people, etc.). The projected image includes, for example, various things such as road signs, the current speed of the own vehicle, and various information added to objects in the scenery. As a result, for example, an augmented reality (AR) function or the like that adds and displays various information to objects in the scenery is realized.

[0074] Next, with reference to FIGS. 14-15, a control example of the transmissive light-shielding switching unit will be described. Note that the processor controls the transmissive light-shielding switching units (924a, 924b). The processor may be the vehicle controller 100, or the MCU or control unit of the display device. Further, the processor that controls the transmissive light-shielding switching unit may be further provided in the display device or the vehicle.

[0075] As shown in FIG. 14, when the control of the transmissive light-shielding switching units (924a, 924b) starts, the processor makes a determination regarding determination item A (S01). Then, according to the determination result, the processor controls in the first mode or the second mode (S02, S03), and ends the process.

[0076] In the first mode, part or all of the display area is in a light-shielded state. When part of the display area is in a light-shielded state, the non-light-shielded part is in a semi-light-shielded state (i.e., semi-transmissive state), so as to achieve both ensuring the driving visibility and the visibility of the display. Also, in the first mode, it is possible to aggregate and display information in a partially light-shielded portion within the display area. For example, when the light-shielded area is adjusted from the entire display area to a part of the display area according to the surrounding situation and vehicle information during driving, such as the driving speed, navigation information, when driving on an ordinary road, when driving on an expressway, etc., the information to be displayed is aggregated to the light-shielded part. Note that when the information to be displayed is aggregated to the light-shielded part, the size of the display content may be reduced, or information with a lower priority may be deleted, and only more important display content may be displayed. In the first mode, for example, the transmissive light-shielding switching units (924a, 924b) may control the light-shielded area according to the shape, contour, and color of the display content, so as to make part of the display area in a light-shielded state. Also, for example, the transmissive light-shielding switching units (924a, 924b) may make only the incident position of the video light and its periphery in a light-shielded state.

[0077] The selection of whether to partially or entirely cover the light-shielding portion of the display area may be automatically controlled. In this case, the processor may select whether to partially or entirely cover the display area, for example, according to the content to be projected. For example, when projecting content related to a video, or when projecting content such as navigation information, the entire display area may be covered. When projecting content of a still image such as sign information, a part of the display area (for example, only the periphery of the content) may be covered. On the other hand, the user may set the light-shielding portion of the display area by themselves.

[0078] In the second mode, the entire area within the display area becomes a semi-light-shielded state (that is, a semi-transmissive state). At this time, the driver can visually recognize the content superimposed on the scenery outside the vehicle.

[0079] With reference to FIG. 15, the example of determination item A related to S01 described above will be specifically explained. In the determination example of this figure, when the determination condition 1 is met, the first mode is selected (S02), and when the determination condition 2 is met, the second mode is selected (S03).

[0080] For example, in S01, the processor determines whether the user has selected the first mode or the second mode (Determination Example 1). That is, when the processor acquires an instruction to shade part or all of the display area, it performs control based on the first mode, and when it acquires an instruction to make all of the display area in a semi-transmissive state, it performs control based on the second mode. For example, when the driver wants to drive while checking the surrounding situation, the driver can, for example, make it in a semi-transmissive state (i.e., the second mode) to make it easier to acquire the surrounding situation. Or, the driver can make only part of the display area in a shaded state (i.e., the first mode) and aggregate information there to make it easier to acquire the surrounding situation. At this time, the information may be displayed small, and visibility can be easily obtained by making it a black background. Also, when the driver wants to drive while looking at navigation information or speed information, the driver, for example, shades the display area. Here, the driver, for example, shades the entire display area.

[0081] For example, in S01, the processor determines whether the remaining battery level of the vehicle is greater than or less than a threshold value (Determination Example 2). That is, the processor determines whether the remaining battery level of the vehicle is less than the threshold value or not less than the threshold value. When the remaining battery level is low, power saving can be achieved by reducing the video brightness in the shaded state.

[0082] For example, in S01, the processor determines whether the brightness outside the vehicle is greater than or less than a predetermined threshold value (Determination Example 3). That is, the processor determines whether the brightness outside the vehicle is greater than the threshold value or not greater than the threshold value. Note that the processor can use, for example, the information acquired using the illuminance sensor 905. When it is bright outside the vehicle, the visibility of the video can be ensured by making it in a shaded state. Also, by making it in a shaded state, the temperature rise due to sunlight incidence can be suppressed, and the product life can be extended. When it is dark outside the vehicle (such as at night), the forward visibility of the driver can be ensured by making it in a semi-transmissive state.

[0083] For example, in S01, the processor determines whether the running speed of the vehicle is greater than or less than a threshold value (Determination Example 4). That is, the processor determines whether the running speed of the vehicle is greater than the threshold value or not greater than the threshold value. Note that the processor can use the information obtained using, for example, the vehicle speed sensor 901. During low-speed driving, since the visibility of the surrounding environment is important, the processor sets the entire display area to a semi-transparent state. For example, when driving at low speed in an urban area or the like, from the perspective of prioritizing ensuring the driving visibility, the processor sets the entire display area to a semi-transparent state. On the other hand, during driving (for example, when driving on an ordinary road or a highway), the processor sets part or all of the display area to a light-shielding state.

[0084] For example, in S01, the processor determines whether the windshield wiper of the vehicle is operating (Determination Example 5). During rainy days, light (for example, external light, headlight light of an oncoming vehicle) is scattered by raindrops, and the visibility of the image deteriorates. Therefore, the light-shielding state is set to improve the image visibility.

[0085] For example, in S01, the processor determines whether raindrops have been detected (Determination Example 6). Note that the processor can use the information obtained using, for example, the raindrop sensor 923. Similar to the case of Determination Example 5, light is scattered by raindrops, and the visibility of the image deteriorates. Therefore, the light-shielding state is set to improve the image visibility.

[0086] For example, in S01, the processor determines whether the ignition switch of the vehicle or the power supply of the vehicle is OFF (Determination Example 7). When the vehicle is not in use (for example, when the ignition of the vehicle is OFF or when the power switch for enabling an electric vehicle to run is OFF), the light-shielding state is set to suppress deterioration of the display device due to external light (sunlight).

[0087] The processor determines, for example, in S01 whether an object (such as a pedestrian or an obstacle) is within a specified range around the vehicle (Determination Example 8). Note that the processor can use information obtained using, for example, a distance measuring sensor 907 (such as a sonar sensor or a millimeter wave radar). Also, for example, an infrared sensor 908 may be used. When an object is detected around the vehicle, the processor makes it in a semi-transmissive state to ensure the field of view. On the other hand, when no object is detected around the vehicle, the processor makes it in a light-shielding state.

[0088] Next, with reference to FIGS. 16-20, a specific structural example of the display device (specifically, the image forming unit 10) will be described.

[0089] FIG. 16A is a diagram showing a configuration example of the image forming unit. The display device includes an image forming unit 10, and the image forming unit 10 includes a display panel 11 having a video display element and a light source device 12 that emits light to the display panel 11. The display device projects the video light of the video formed on the display panel 11 onto a projection member using the light emitted from the light source device 12 (in other words, the light source light). The display device may be referred to as a projection type display device. The display panel 11 forms a video for projection onto the projection member based on video data and emits it as video light (in other words, projection light). Also, the display panel 11 may be a liquid crystal panel LCD (Liquid Crystal Display) or the like. In the present embodiment, the projection member or the projection unit that projects the video light is the display area 5 of the windshield 3, but it is not limited to the display area 5 of the windshield 3.

[0090] On the other hand, the display panel 11 may be a screen plate having a diffusion function, not limited to a liquid crystal panel. As means for projecting a video for forming a real image onto the screen plate having a diffusion function, means such as a DMD (Digital Micromirror Device) or means for projecting an image of a liquid crystal panel in combination with a projection lens, or means using a Micro Electro Mechanical Systems may be used.

[0091] The light source device 12 includes a light source 20, a reflection mirror 21 (optical component), and a reflective optical element 23a. Further, the light source device 12 may include a polarization conversion element 22 and a diffusion plate 25. The light source 20 typically includes an LED (Light Emitting Diode) and may be referred to as a backlight unit. The light source 20 is composed of one or more LED light sources, and the plurality of LED light sources may be arranged in a row, or may be arranged in two or more rows, and may be arranged according to the design.

[0092] The reflection mirror 21 is configured to reflect the light from the light source 20 and adjust it to substantially parallel light or parallel light. The reflecting surface of the reflection mirror 21 is a parabolic surface and may have a shape asymmetric with respect to the optical axis of the emitted light of the light source 20. Further, the reflection mirror 21 may be arranged eccentrically with respect to the light source 20. The reflection mirror 21 may also be referred to as a reflecting portion or a reflector. In the present embodiment, the reflection mirror 21 is used for explanation, but the optical component may be a collimating lens.

[0093] The polarization conversion element 22 is composed of a polarizing beam splitter (PBS) and a retardation film (1 / 2λ). It separates the incident light into S-polarized light and P-polarized light, and converts either the separated S-polarized light or P-polarized light by the retardation film (1 / 2λ) to emit the random polarized light incident on the polarization conversion element 22 as linearly polarized light. In the present embodiment, by aligning the polarization of the light emitted from the light source 20 with the polarization conversion element 22, high efficiency of image projection is achieved.

[0094] The reflective optical element 23a may also be referred to as a light guide portion or a light guide body. The reflective optical element 23a is configured to adjust the incident angle of light rays onto the display panel 11, and as an example, it may be a prism sheet. The reflective optical element 23a in the present embodiment has a light reflection portion 24 having a prism shape (a serrated shape), and the light rays incident on the light reflection portion 24 are adjusted to have a predetermined light distribution and are reflected toward the display panel 11 side. The distribution of the light incident on the display panel 11 can be adjusted by the shape of the reflection surface of the light reflection portion 24, the inclination of the reflection surface, the surface roughness, and the like. Further, the reflective optical element 23a is, for example, a resin member having a prism shape, and a reflection film or the like is coated on the prism-shaped portion serving as the reflection surface. Therefore, in the structure of FIG. 16A, the optical axis of the light source 20 and the optical axis of the light incident on the display panel 11 are parallel or substantially parallel.

[0095] FIG. 16B shows an enlarged view of the light reflection portion 24 of the reflective optical element 23a. In the light reflection portion 24, a large number of reflection surfaces and connection surfaces are alternately formed in a serrated shape. The light incident on the reflective optical element 23a is reflected on each reflection surface and travels upward. Further, through the diffusion plate 25, it is adjusted to have predetermined light distribution characteristics and is incident on the display panel 11. Further, the elevation angles α1a, α2a, α3a, α4a... of the reflection surfaces are arbitrarily set so as to obtain predetermined light distribution characteristics. On the other hand, the relative angles β1a, β2a, β3a, β4a... between the reflection surface and the connection surface are set at a constant angle regardless of the location, and more preferably, at an angle of 90 degrees or more (βna ≧ 90°). When the reflective optical element 23a is manufactured by injection molding, by setting the relative angle βna to 90 degrees or more, the mold processing of the reflection surface and the connection surface becomes easy.

[0096] By appropriately setting the lengths and ratios of the connection surfaces Lc1a, Lc2a, Lc3a ··· and the reflection surfaces Lr1a, Lr2a, Lr3a ···, it becomes possible to realize a light source unit in which the irradiation range of the light reflected by the reflection optical element 23a can be changed to a required size (surface size) for devices such as the display panel 11. Also, by appropriately adjusting the ratio Lr / Lc, it is possible to strengthen or weaken the reflected light partially. For example, the ratio Lr / Lc is adjusted according to the intensity distribution of the light incident on the light reflection unit 24. More specifically, at locations where the intensity of the incident light is strong in the light reflection unit 24, the ratio Lr / Lc is made small, that is, the reflection surface elevation angle αna is set at a fine pitch, so that the reflection direction of the light can be precisely controlled, and the luminance distribution of the light incident on the display panel 11 can be adjusted uniformly.

[0097] FIG. 17 shows a modified example of the display device shown in FIG. 16A. According to the reflection optical element 23b of FIG. 17, as shown in FIG. 16B, the ratio Lrb / Lcb of the length Lrb of the inclined surface projected onto a plane orthogonal to the emission direction of the plurality of reflection surfaces of the light reflection unit 232 and the length Lcb of the inclined surface projected onto a plane orthogonal to the emission direction of the connection surface connecting the reflection surfaces is made variable depending on the location. Therefore, by appropriately setting the lengths and ratios of the connection surfaces Lcb1, Lcb2, Lcb3 ··· and the reflection surfaces Lrb1, Lrb2, Lrb3 ···, the length of the light emission unit 233 in the optical axis direction can be freely changed. Thus, it becomes possible to realize a light source unit in which the size (surface size) of the light emission unit 233 can be changed to a required size (surface size) for devices such as the display panel 11 with respect to the light incident unit 231.

[0098] Similarly, by appropriately adjusting the ratio Lr / Lc as described above, it is also possible to intensify or weaken the reflected light partially. For example, the ratio Lr / Lc is adjusted according to the intensity distribution of the light incident on the light reflection part 232. More specifically, at a location where the intensity of the incident light is strong in the light reflection part 232, the ratio Lr / Lc is decreased, that is, the reflection surface elevation angle αnb is set at a fine pitch, so that the reflection direction of the light can be precisely controlled, and the luminance distribution of the light incident on the display panel 11 can be adjusted uniformly.

[0099] As shown in FIG. 18, as an example, the image forming unit 10 may have an edge type backlight structure. A plurality of light sources 20 are arranged side by side in the depth direction of the paper so as to face the side surface of the light guide 23. The light guide 23 (reflection optical element) is arranged on the back side of the display panel 11, and a plurality of reflection dots 27 that emit light toward the display panel 11 are provided on the light guide 23. The reflection dots 27 diffusely reflect the guided light, whereby illuminance uniformity is obtained. The reflection dots 27 are formed on the light guide 23 by printing white ink, forming an uneven shape, forming a groove pattern, or the like. In addition, in order to obtain illuminance uniformity at positions close to and far from the light source 20, the reflection dots 27 may be formed so that the density of the reflection dots 27 increases as the distance from the light source 20 increases. Further, a reflection sheet 28 is provided so as to face the display panel 11, and the light guide 23 is arranged between the display panel 11 and the reflection sheet 28. In this case, the light that is not diffusely reflected by the reflection dots 27 and is emitted from the light guide 23 in the direction opposite to the display panel 11 is reflected by the reflection sheet 28 and enters the display panel 11 through the light guide 23. Also, in this example, a diffusion plate 25 is provided between the display panel 11 and the light guide 23, but the diffusion plate 25 may be omitted. Further, the diffusion plate 25 may be arranged at the subsequent stage of the display panel 11. Also, in this example, a reflection sheet 28 for making light incident on the light guide 23 is provided, but the reflection sheet 28 may be omitted.

[0100] As shown in FIG. 19, the image forming unit 10 may, for example, have a direct - type backlight structure. A plurality of light sources 20 are arranged below the display panel 11. The plurality of light sources 20 can be configured, for example, as an LED array related to micro - LEDs or mini - LEDs. In this example, the plurality of light sources 20 are provided on a substrate, and a reflective sheet 28 is provided on the surface of the substrate facing the display panel 11. A diffusion plate 25 is arranged between the display panel 11 and the reflective sheet 28. Further, a plurality of reflective dots 27 are formed on the diffusion plate 25 so as to face the light sources 20. By configuring in this way, the light directly above the light sources 20, which is likely to form high - brightness spots, is reflected by the reflective dots 27 and then by the reflective sheet 28 on the substrate. Thereby, it becomes possible to uniformly adjust the luminance distribution of the light incident on the display panel 11. The reflective dots 27 are formed on the diffusion plate 25 by printing white ink, forming an uneven shape, forming a groove pattern, etc. Note that the reflective sheet 28, the diffusion plate 25, and the reflective dots 27 may be omitted. Also, a plurality of diffusion plates 25 without the reflective dots 27 may be used.

[0101] As shown in FIG. 20, the image forming unit 10 may, for example, have a fly - eye integrator type structure. Between the display panel 11 and the light source 20, a lens array 31, a fly - eye lens 32, and a focus lens 33 are arranged in the order of the light traveling direction. The lens array 31 makes the light (LED light) irradiated by the plurality of light sources 20 (LEDs) into substantially parallel light. The fly - eye lens 32 enhances the uniformity of the irradiation surface by forming an image of the light - emitting element. Note that a configuration in which two fly - eye lenses are combined may be used. That is, a configuration may be used in which the light flux is divided by the first fly - eye lens and each light flux is guided to the irradiation area by the second eccentric fly - eye lens. The focus lens 33 is configured to condense the light from the light source 20 onto the irradiation surface.

[0102] From the above description, as an example, a display device including a light source 20, a display panel 11, and a transmissive / light-shielding switching unit (924a, 924b) is provided. That is, this display device is a device mounted on the vehicle 2. Light from the light source 20 is incident on the display panel 11. Image light projected by the display panel 11 is incident on the transmissive / light-shielding switching unit (924a, 924b). The transmissive / light-shielding switching unit (924a, 924b) is disposed in front of the driver, and can switch between a light-shielding state and a semi-transmissive state in part or all of the region (the region corresponding to the display region 5) where the image light is incident. Further, for example, this display device may include a processor (for example, the vehicle controller 100 or the MCU of the display device) that controls the switching between the light-shielding state and the semi-transmissive state of the transmissive / light-shielding switching unit (924a, 924b). Then, using this processor, for example, the processes described with reference to FIGS. 14-15 may be performed.

[0103] As described above, the embodiments have been described. However, the present invention is not limited to the above-described embodiments, and includes various modifications and equivalent configurations within the scope of the appended claims. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and the present invention is not necessarily limited to those having all the configurations described. Further, for example, for a part of the configuration of the embodiment, addition, deletion, or replacement with other configurations may be made.

[0104] By using a transmissive light-shielding switching unit containing a photochromic dye, switching between a light-shielded state and a semi-transmissive state may be performed. In this case, depending on the amount of ultraviolet or visible light, the dye is colored or decolorized, so that the transmittance naturally changes. When it is bright outside the vehicle, the transmissive light-shielding switching unit becomes light-shielded, and when it is dark outside the vehicle (at night, inside a tunnel, etc.), it becomes semi-transmissive. That is, the transmittance of this transmissive light-shielding switching unit naturally changes according to the brightness outside the vehicle. Therefore, switching between the light-shielded state and the semi-transmissive state is possible without being controlled by a processor. By arranging the transmissive light-shielding switching unit or the light-shielding unit, a double image caused by Fresnel reflection of the video light on the back surface (the outer surface of the vehicle) of the windshield can be suppressed, the visibility of the content can be improved, and a more suitable display device can be realized.

[0105] In the determination shown in FIGS. 14 and 15, as an example, the processor may determine whether the vehicle 2 is in an automatic driving state (or in a cruise control state). During automatic driving or cruise control, by making the entire display area light-shielded, vehicle information (such as driving status) can be prioritized over the driving view, and the information can be displayed largely. Also, it is possible to display moving image content or the like on a large screen. Here, from the viewpoint of displaying information largely, as an example, the transmissive light-shielding switching unit may be provided over the entire lower part of the windshield as shown in FIG. 3A or the like. That is, the transmissive light-shielding switching unit may be provided across the lower part of the windshield 3 from left to right.

[0106] The alignment control of the dye or pigment can be performed based on an appropriate method. For example, a configuration for applying an electric field in a predetermined direction may be provided. And this configuration may be controlled by a processor (for example, the vehicle controller 100 or the MCU of the display device).

[0107] In the technology according to the embodiment of the present invention, by arranging a transmission and light shielding switching unit that switches between a light shielding state and a semi-transmissive state in part or all of the region where video light is incident, the visibility of the content can be improved, a more suitable display device can be realized, and by providing a display device that contributes to the support of safe driving, it becomes possible to prevent traffic accidents. Thereby, it contributes to "3 Good health and well-being for all" of the Sustainable Development Goals (SDGs) proposed by the United Nations.

Explanation of symbols

[0108] 1 Display device 10 Image forming unit 11 Display panel 12 Light source device 20 Light source 21 Reflective mirror (optical component) 22 Polarization conversion element 23 Light guide 23a Reflective optical element 23b Reflective optical element 24 Light reflection part 25 Diffusion plate 27 Reflective dot 28 Reflective sheet 31 Lens array 32 Fly-eye lens 33 Focus lens 923a Transmission and light shielding switching unit 923b Transmission and light shielding switching unit

Claims

1. A display device mounted on a vehicle, comprising: a light source; a display panel onto which light from the light source is incident; a transmissive light-shielding switching unit onto which image light projected by the display panel is incident; and the transmissive light-shielding switching unit is capable of switching between a light-shielding state and a semi-transmissive state in part or all of the region where the image light is incident. The display device is characterized by the above.

2. The display device according to claim 1, wherein the transmissive light-shielding switching unit contains a dye or pigment, and in the portion that becomes the light-shielding state, the dye or pigment is not oriented in a specific direction. The display device is characterized by the above.

3. The display device according to claim 1, wherein the transmissive light-shielding switching unit contains a dye or pigment, and in the portion that becomes the semi-transmissive state, the dye or pigment is oriented in a predetermined direction. The display device is characterized by the above.

4. The display device according to claim 3, wherein the transmissive light-shielding switching unit contains a dye or pigment, and in the portion that becomes the semi-transmissive state, the dye or pigment is oriented so as to form an angle of approximately 45° with respect to the width direction and the vertical direction of the vehicle within the plane formed by the width direction and the vertical direction of the vehicle. The display device is characterized by the above.

5. The display device according to claim 3, wherein the transmissive light-shielding switching unit contains a dye or pigment, and in the portion that becomes the semi-transmissive state, the dye or pigment is oriented in the longitudinal direction of the vehicle, or the width direction of the vehicle, or the vertical direction of the vehicle. The display device is characterized by the above.

6. The display device according to claim 1, wherein the transmissive light-shielding switching unit has a shape in which the region in the light-shielding state is longer in the left-right direction of the vehicle than the region where the image light is incident, and has a substantially trapezoidal shape in which the length in the left-right direction becomes shorter as it goes from the lower part to the upper part of the vehicle, and the size of the content drawn by the display panel, the font size, or the left-right dimension of the vehicle within the same content becomes smaller as it goes from the lower part to the upper part of the vehicle. The display device is characterized by the above.

7. The display device according to claim 1, further comprising a processor in the display device or the vehicle that controls the switching between the light-shielding state and the semi-transmissive state of the transmissive light-shielding switching unit, and the processor shields part or all of the region in the light-shielding state when the remaining battery level of the vehicle is less than a threshold value. The display device is characterized by the above.

8. ​ The display device according to claim 1, wherein the display device or the vehicle further comprises a processor for controlling switching between the light-shielding state and the semi-transmissive state of the transmissive light-shielding switching unit, the processor makes part or all of the region in the light-shielding state when the brightness outside the vehicle is greater than a threshold value, and makes all of the region in the semi-transmissive state when the brightness outside the vehicle is not greater than the threshold value, characterized in that it is a display device.

9. The display device according to claim 1, wherein the display device or the vehicle further comprises a processor for controlling switching between the light-shielding state and the semi-transmissive state of the transmissive light-shielding switching unit, the processor makes part or all of the region in the light-shielding state when the traveling speed of the vehicle is greater than a threshold value, and makes all of the region in the semi-transmissive state when the traveling speed of the vehicle is not greater than the threshold value, characterized in that it is a display device.

10. The display device according to claim 1, wherein the display device or the vehicle further comprises a processor for controlling switching between the light-shielding state and the semi-transmissive state of the transmissive light-shielding switching unit, the processor makes part or all of the region in the light-shielding state when the wiper of the vehicle is operating or raindrops are detected, characterized in that it is a display device.

11. The display device according to claim 1, wherein the display device or the vehicle further comprises a processor for controlling switching between the light-shielding state and the semi-transmissive state of the transmissive light-shielding switching unit, the processor makes part or all of the region in the light-shielding state when the ignition switch or power supply of the vehicle is OFF, characterized in that it is a display device.

12. The display device according to claim 1, wherein the display device or the vehicle further comprises a processor for controlling switching between the light-shielding state and the semi-transmissive state of the transmissive light-shielding switching unit, the processor makes all of the region in the semi-transmissive state when there is an object within a specified range around the vehicle, characterized in that it is a display device.

13. The display device according to claim 1, wherein the display device or the vehicle further comprises a processor for controlling switching between the light-shielding state and the semi-transmissive state of the transmissive light-shielding switching unit, the processor makes all of the region in the light-shielding state when the vehicle is in autonomous driving or cruise control, characterized in that it is a display device.

14. A display device mounted on a vehicle, comprising a light source, and A display panel onto which light from the light source is incident; A transmissive light-shielding switching unit onto which image light projected by the display panel is incident; comprising: The transmissive light-shielding switching unit: is disposed in front of the driver, contains a photochromic dye, and can switch between a light-shielding state and a semi-transmissive state according to the amount of ultraviolet light or visible light; A display device characterized by the above.

15. A display device mounted on a vehicle, comprising: a light source; a display panel onto which light from the light source is incident; a light-shielding unit onto which image light projected by the display panel is incident; comprising: The light-shielding unit has a shape that is longer in the left-right direction of the vehicle than the region where the image light is incident, and is in a substantially trapezoidal shape whose length in the left-right direction decreases as it goes from the lower part to the upper part of the vehicle, wherein the size of the content drawn by the display panel, the font size, or the dimension of the vehicle in the left-right direction within the same content decreases as it goes from the lower part to the upper part of the vehicle; A display device characterized by the above.

16. A vehicle equipped with the display device according to any one of Claim 1, Claim 14, or Claim 15.

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