Indication device

Abstract

To provide a more suitable display device or display technology. According to the present invention, it contributes to Sustainable Development Goal 3, "Good Health and Well-being for All." [Solution] A display device to be placed on the dashboard of a vehicle, comprising a light source device provided in a housing, and a display panel provided in the housing that generates image light based on the light emitted from the light source device, and also comprising a light shielding plate provided on the housing in the vertical direction that blocks at least a portion of the external light that enters the eye box of the vehicle driver.

Description

Technical Field

[0006] , , ,

[0005] , ,

[0001] The present invention relates to a display device, a virtual image display device, and a vehicle equipped with the display device.

Background Art

[0002] There is known a display device or a virtual image display device that projects video light onto a windshield or a front glass of a vehicle such as an automobile to display a virtual image, and displays driving information such as vehicle speed and engine speed, traffic information from navigation, and vehicle information such as remaining fuel and coolant temperature.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The display device is disposed, for example, on or inside the dashboard of a vehicle. When using the display device, a driver can obtain information necessary for driving without moving his / her line of sight to an instrument panel incorporated in the dashboard, that is, a so-called instrument panel. On the other hand, sufficient consideration has not been given to the arrangement, brightness, influence from external light, information display, etc. of the display device. [[ID=​​​​​​​​According to an aspect of the present invention, the following display device is provided. The display device is placed on the dashboard of a vehicle and comprises a light source device provided in a housing, and a display panel provided in the housing that generates image light based on the light emitted from the light source device, and also comprises a light shield plate provided on the housing in the vertical direction that blocks at least a portion of the ambient light that enters the eye box of the vehicle driver. [Effects of the Invention]

[0007] According to the present invention, a more suitable display device or display technology can be provided. Other problems, configurations, and effects not mentioned above will be clarified by the following description of the embodiments. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows an example of an in-vehicle system including a display device. [Figure 2] This figure shows an example of a device used to acquire vehicle information. [Figure 3] This is a block diagram showing an example of a display device. [Figure 4] This figure shows an example of a configuration in which a display device is installed in a vehicle. [Figure 5] This figure shows an example of a configuration in which a display device is installed in a vehicle. [Figure 6] This figure shows an example of a light source structure for a display device. [Figure 7] This figure shows an example of a configuration in which the display device according to Embodiment 1 is mounted on a vehicle. [Figure 8] This is a perspective view showing an example of a light-shielding plate according to Example 1. [Figure 9] This figure shows an example of a configuration in which the display device according to Example 2 is mounted on a vehicle. [Figure 10A] This figure shows an example of a configuration in which the display device according to Embodiment 3 is mounted on a vehicle. [Figure 10B] This figure shows an example of a configuration in which the display device according to Embodiment 3 is mounted on a vehicle. [Figure 11A]This figure shows an example of a configuration in which the display device according to Embodiment 3 is mounted on a vehicle. [Figure 11B] This figure shows an example of a configuration in which the display device according to Embodiment 3 is mounted on a vehicle. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings. The embodiments are illustrative examples for explaining the present invention, and have been omitted and simplified as appropriate for clarity of explanation. The present invention can also be implemented in various other forms. Unless otherwise specified, each component may be singular or plural. The position, size, shape, and range of each component shown in the drawings may not represent the actual position, size, shape, and range in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, and range disclosed in the drawings. When there are multiple components that have the same or similar function, they may be described using the same reference numeral with different subscripts. Also, when it is not necessary to distinguish between these multiple components, the subscripts may be omitted in the description.

[0010] In explanations, when describing program-based processing, the focus may sometimes be on the program, functions, or processing units. However, the core hardware component is the processor, or a controller, device, computer, or system composed of such a processor. The computer, using its processor, executes processing according to the program read into memory, utilizing resources such as memory and communication interfaces as appropriate. This realizes the specified functions and processing units. The processor is composed of semiconductor devices such as CPUs / MPUs and GPUs. Processing is not limited to software program processing; it can also be implemented using dedicated circuits. FPGAs, ASICs, CPLDs, etc., can be used as dedicated circuits.

[0011] The program may be pre-installed as data on the target computer, or it may be distributed as data to the target computer from the program source. The program source may be a program distribution server on a communication network, or a non-transient computer-readable storage medium, such as a memory card or disk. The program may consist of multiple modules. The computer system may consist of multiple devices. The computer system may consist of a client-server system, a cloud computing system, an IoT system, etc. Various types of data and information are composed of structures such as tables and lists, but are not limited to these. Representations such as identification information, identifiers, IDs, names, and numbers are interchangeable.

[0012] Figure 1 shows an example configuration of an in-vehicle system including a display device or virtual image display device 1. With respect to the vehicle or ride 2 and the driver, the horizontal direction X is the left-right direction, the lateral direction of the vehicle or ride 2, or the width direction of the vehicle or ride 2; the vertical direction Z is the up-down direction, or vertical direction of the vehicle; and the horizontal direction Y, which is perpendicular to the lateral direction of the vehicle or ride 2, is the front-rear direction of the vehicle or ride 2, or the direction of travel of the vehicle. In the example in Figure 1, the direction in which the vehicle travels is set to be the negative direction in the Y-axis direction. The display device 1 may also be called a virtual image display device. The following explanation will use the name "display device". The vehicle or ride 2 is typically an automobile or a truck, but is not limited to these, and may also be a railway vehicle or an aircraft. The following explanation will use the name "vehicle".

[0013] The display device 1 acquires vehicle information 4 from cameras and various sensors installed in each part of the vehicle 2. The display device 1 may also be referred to as a virtual image display device. The various sensors detect, for example, various events occurring in the vehicle 2 and periodically detect the values of various parameters related to the driving situation. In addition, it can acquire information on roads and the like, as well as GPS (Global Positioning System) information, from the navigation device 6 (car navigation), the external device 400, and the terminal device (e.g., mobile terminal) 410. The GPS may be installed in the vehicle 2, or may be installed in the external device 400 or the terminal device 410.

[0014] 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-of-vehicle camera video information. The GPS information includes current time information in addition to latitude and longitude. In addition, the vehicle information 4 includes input information from the driver.

[0015] 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 via the information transmission path, for example, by means of a CAN (Controller Area Network) or LIN (Local Interconnect Network) interface. Note that the display device 1 and the controller 100 of the vehicle 2 may communicate via in-vehicle Ethernet or the like via the information transmission path. Also, other connection forms may be adopted. For example, when all information including video information is transmitted via one information transmission path, the connection between the controller 100 on the vehicle 2 side (the source of video information, etc.) 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), or the like.

[0016] The controller 100 controls the vehicle 2 based on input and output of data, and an in-vehicle system is configured with a configuration connected to the display device 1. The in-vehicle system can communicate with the outside of the vehicle 2 via a communication device or a network or the like. As an example of communication with the outside of the vehicle 2, a direct communication method or an indirect communication method is used. In the direct communication method, it is used as ITS (Intelligent Transport System) communication internationally, and in the indirect communication method, for example, communication is performed indirectly via an external device 400 or a terminal device 410 via a server. The in-vehicle system can transmit and receive data or information with, for example, a server 700 connected on the network 500 via a relay base 600 on the network 500. Also, the in-vehicle system may communicate with an infrastructure such as an external device or a terminal installed on the road on which the vehicle 2 travels.

[0017] Figure 2 shows an example of a device used to acquire vehicle information. As shown in Figure 2, vehicle information 4 is acquired using devices such as a camera and various sensors connected to the controller 100 or control device 100. Note that the various devices in Figure 2 can be deleted, other types of devices added, or replaced with other types of devices as appropriate. Also, as an example, the controller 100 of vehicle 2 may also have the function of controlling the display device 1.

[0018] The vehicle speed sensor 901 detects the speed of vehicle 2 and is used to generate speed information as a result of the detection. The shift position sensor 902 detects the current gear and is used to generate gear information as a result of the detection. The steering angle sensor 903 detects the current steering angle and is used to generate steering angle information as a result of the detection. The headlight sensor 904 detects whether the headlights are ON or OFF and is used to generate lamp illumination information as a result of the detection.

[0019] The illuminance sensor 905 and the chromaticity sensor 906 detect ambient light from the vehicle 2 and are used to generate ambient light information as detection results. The distance measuring sensor 907 detects the distance between the vehicle 2 and an external object, or the distance between external objects, and is used to generate distance information as detection results. The infrared sensor 908 detects the presence and distance of objects in the vicinity of the vehicle 2 and is used to generate infrared information as detection results. The engine start sensor 909 detects the ON / OFF status of the engine and is used to generate ON / OFF information as detection results. 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.

[0020] The temperature sensor 914 detects the temperature inside and outside the vehicle and is used to generate temperature information as the detection result. For example, if the display device 1 is located inside the dashboard of the vehicle 2, the temperature sensor 914 may be used to detect the temperature inside the dashboard. If a temperature that may affect the operation of the display device 1 is detected, the display device 1 may stop operating. The temperature sensor 914 may also be located in other places that may experience temperatures similar to those inside the dashboard.

[0021] Furthermore, if the display device 1 is installed on the dashboard or elsewhere, the temperature sensor 914 may be used to detect the temperature in the vicinity where the display device 1 is installed. If a temperature is detected that may affect the operation of the display device 1 due to direct sunlight or the like, the display device 1 may stop operating. Here, the temperature sensor 914 may be placed on the dashboard as an example. The temperature sensor 914 may also be placed outside the vehicle, assuming that the temperature near the display device 1 and the temperature outside the vehicle are similar.

[0022] The vehicle-to-infrastructure wireless transceiver 915 generates vehicle-to-infrastructure communication information through vehicle-to-infrastructure communication between vehicle 2 and roads, signs, signals, etc. The vehicle-to-vehicle wireless transceiver 916 generates vehicle-to-vehicle communication information through vehicle-to-vehicle communication between vehicle 2 and other surrounding vehicles. The wired wireless communication unit 917 for mobile terminal-to-vehicle communication is a device that acquires information from devices connected to the LTE (Long Term Evolution) network (e.g., WiFi devices) via wired or wireless communication. The controller 100 or control device can acquire information transmitted and received on the LTE network via the wired wireless communication unit 917 for mobile terminal-to-vehicle communication.

[0023] The in-vehicle camera 919 and the exterior camera 920 capture images of the interior and exterior of the vehicle and are used to generate in-vehicle and exterior camera image information. Specifically, the in-vehicle camera 919 is, for example, a camera for a Driver Monitoring System (DMS) that captures the driver's posture, eye position, and movement. In this case, by analyzing the captured images, the driver's fatigue level and gaze position can be determined.

[0024] On the other hand, the external camera 920 captures the surrounding environment, such as the front and rear of vehicle 2. In this case, by analyzing the captured images, it becomes possible to determine the presence or absence of obstacles such as other vehicles or people in the vicinity, buildings and terrain, road surface conditions such as rain, snow, ice, and unevenness, and road signs. The external camera 920 also includes, for example, a dashcam that records the driving situation in video.

[0025] The GPS receiver 921 generates GPS information obtained by receiving GPS signals from GPS satellites. For example, the GPS receiver 921 can obtain the current time, latitude, and longitude. 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 a navigation system.

[0026] The voice input device 918 receives the driver's voice and is used to generate voice information. The driver can input operation details via the voice input device 918 by speaking. The vehicle operation switch 911 is used to generate driver operation information for steering wheel switches, etc.

[0027] Furthermore, the video generation unit 910 generates video information based on the vehicle information 4 acquired by the controller 100 of the vehicle 2. It can also generate video information based on external information.

[0028] Figure 3 is a block diagram of the display device 1. It primarily controls the display of projected images (virtual images) on the display device 1.

[0029] In Figure 3, the display device 1 includes, for example, a control unit 1010, a non-volatile memory 1011, a volatile memory 1012, a storage unit 1013, a display driver 1021, and a light source drive unit 1022, all of which are mounted on a wiring board or the like. The display device 1 also includes a communication unit 1014, a wireless communication unit 1015, a video processing unit 1016, an operation input unit 1017, an external power input unit 1018, a speaker 1019, and a light-emitting indicator 1020.

[0030] The control unit 1010 is specifically a microcontroller (MCU) or a CPU (Central Processing Unit). Each block other than the control unit 1010 may be mounted within the control unit 1010 as appropriate. Furthermore, the display device 1 is not limited to implementation using the control unit 1010; it may also be implemented using an ECU (Electronic Control Unit) or other semiconductor devices. The configuration shown in Figure 3 may, for example, involve a control unit mounted inside the housing of the display device 1, or a control unit mounted outside the housing. Additionally, the display device 1 can be controlled by a controller in the vehicle 2 or an external device without implementing the control unit 1010 within the display device 1.

[0031] The non-volatile memory 1011 primarily stores programs executed within the control unit 1010, setting parameters used in the processing of each part within the control unit 1010, and predefined audio and video data. The non-volatile memory 1011 may also store information other than programs, such as video, audio, and video.

[0032] The volatile memory 1012 operates by expanding the program stored in the non-volatile memory 1011. The volatile memory 1012 primarily processes acquired information and various data used in the processing of each part within the control unit 1010 as appropriate.

[0033] The storage unit 1013 stores video data, video data, or audio data for output to the speaker 1019, etc. The video data, video data, or audio data to be stored in the storage unit 1013 may be stored in the storage unit 1013 in advance. Alternatively, the video data, video data, or audio data to be stored in the storage unit 1013 may be received from an external device via the communication unit 1014.

[0034] In Figure 3, the communication unit 1014 transmits and receives information such as vehicle information 4 to and from the controller 100 of the vehicle 2 or various devices such as sensors in the vehicle 2, using a mechanism such as CAN or in-vehicle Ethernet. The communication unit 1014 may also receive video information using a mechanism such as FPD-Link III or GMSL. The hardware of the communication interface that receives vehicle information 4 and the hardware of the communication interface that receives video information in the communication unit 1014 may be separate or integrated. The communication unit 1014 may also function as the control unit of the display device 1.

[0035] The wireless communication unit 1015 may be configured with a Wi-Fi communication interface, a Bluetooth® communication interface, a mobile communication interface such as 4G or 5G, etc. As shown in Figure 1, the wireless communication unit 1015 may communicate with external devices via a network 500 connected through a router or relay station 600. An example of an external device is a server 700 connected via network 500. Alternatively, the wireless communication unit 1015 may communicate directly with a terminal device 410, etc. An example of a terminal device 410 is a smartphone, tablet, wireless earphones, headphones, or beacon.

[0036] The video processing unit 1016 may perform distortion correction, conversion, and other processing on the received video information. The video processing unit 1016 may generate video data for the video display unit 200 using acquired vehicle information, external information, etc. Specifically, the distortion correction here corrects 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, as shown in Figure 1. The video processing unit 1016 may also be implemented by the control unit 1010 reading and executing a program stored in the non-volatile memory 1011 or volatile memory 1012.

[0037] In other words, the video processing unit 1016 processes video data related to the display video projected onto the display area 5, such as in Figure 1, based on information acquired from an external source or from the vehicle 2. On the other hand, the video processing unit 1016 is not necessarily required, but in such a case, the control unit 1010 can process video information from the vehicle 2 or an external terminal via the communication unit 1014. Alternatively, the controller 100 of the vehicle 2 may process the video information.

[0038] The operation input unit 1017 is, for example, an operation button, a receiver for a remote controller, or an infrared light receiver, and is used to input user operations. The operation input unit 1017 may be used, for example, for the driver to operate the display device 1.

[0039] The external power input unit 1018 receives power from an external source and supplies the necessary power to each part of the display device 1 shown in Figure 3.

[0040] The speaker 1019 emits sound based on audio data stored in the volatile memory 1012, the non-volatile memory 1011, or the storage unit 1013.

[0041] The light-emitting indicator 1020 emits light using a light-emitting element or the like, and can notify the user of the status of the display device 1 by the timing of the light emission of the light-emitting element or the color of the emitted light.

[0042] The display driver 1021 drives each display element (pixel) included in the display panel 11 based on the video data. This allows the video display unit or video display unit 200 to create and display an image for projection onto the display area 5 based on the video data. The display driver 1021 can be configured, for example, by a circuit mounted on a circuit board.

[0043] The light source drive unit 1022 drives the light source 20 to generate light. Based on the drive from the light source drive unit 1022, the light source 20 generates light and supplies it to the display panel 11. Based on vehicle information 4 received via the communication unit 1014, or information from a terminal device, the light source 20 is adjusted or controlled using the light source drive unit 1022, which is the driver used to drive the light source 20.

[0044] Furthermore, the display device 1 may protect the display panel 11 based on ambient light information from the illuminance sensor 905. That is, in order to prevent the display panel 11 from being burned out by sunlight, the display device 1 may perform an operation to protect the display panel 11 from sunlight according to the value of the illuminance sensor 905. More specifically, if the intensity of ambient 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 brightness of the light source 20 is reduced, and the amount of light from the light source 20 that enters the display panel 11 is suppressed, thereby suppressing the temperature rise of the display panel 11.

[0045] Each component in Figure 3 may be implemented using a dedicated circuit such as an FPGA (Field Programmable Gate Array) as appropriate. In this embodiment, the system has a configuration that includes a non-volatile memory 1011, a volatile memory 1012, a storage unit 1013, and a video processing unit 1016, but the above processing may be performed using a single memory.

[0046] Next, the video display unit 200 will be described in detail. The video display unit (video display unit) 200 projects video light onto the display panel 11 using light emitted from the light source 20 (in other words, light from the light source) based on video data. The video display unit 200 may also be called a projection-type video display device or a projector. The video display unit 200 comprises a light source 20 and a display panel 11 such as a liquid crystal display (LCD) having video display elements.

[0047] The light source 20 functions as a backlight source for the display panel 11. The light source 20 is configured, for example, using a semiconductor light source element, and generates a predetermined light source and supplies it to the display panel 11. Typically, an LED (Light Emitting Diode) element is used as the semiconductor light source element. The light source 20 may also be configured by arranging multiple light sources. The backlight section is configured using the light source 20, etc.

[0048] The display panel 11 generates and emits modulated video light based on the light source. In other words, the display panel 11 forms and displays an image on the display screen based on video data, and generates and emits video light corresponding to the image based on the light from the light source 20. The video data in this embodiment will be described as video data input from the video processing unit 1016. The display panel 11 forms an image to be projected onto the display area 5 by modulating the light from the light source 20 pixel by pixel according to the video data, and projects it as video light (in other words, projected light).

[0049] Furthermore, the display panel 11 is not limited to a liquid crystal panel; it may also be a screen plate with a diffusion function. As a means of projecting an image onto the screen plate with a diffusion function, a means of projecting an image from a DMD (Digital Micromirror Device) or a liquid crystal panel in combination with a projection lens, or a means of using a micro electro-mechanical system may be used.

[0050] Figures 4 and 5 show examples of configurations in which the display device 1 is projected onto a vehicle 2. Figure 4 shows an example of projecting the display device 1 onto a passenger car. Passenger cars include sports cars, sedans, SUVs (Sport Utility Vehicles), and minivans, where the angle of the windshield 3 is 20° to 45° with respect to the Y-axis (the longitudinal direction or direction of travel of the vehicle 2). Figure 5 shows an example of projecting the display device 1 onto some passenger cars and commercial vehicles, in other words, the windshield or windshield 3 in Figure 5 is in an upright position. Specifically, these include light super-height wagons, trucks, and buses, where the angle of the windshield 3 is 45° to 90° with respect to the Y-axis (the longitudinal direction or direction of travel of the vehicle 2). As shown in Figures 4 and 5, the display device 1 is located on the dashboard 7 of the vehicle 2. The display device 1 may also be implemented so as to be embedded within the dashboard 7. The dashboard 7 also includes an instrument panel, for example, a meter cluster in front of the steering wheel.

[0051] As shown in Figures 4 and 5, the image light 13 in Figure 4 is emitted toward the driver, and the image light 13 in Figure 5 is emitted toward the windshield 3. The image light 13 emitted from the display device 1 is reflected when it is irradiated onto the windshield or windshield 3. The reflected image light 13 is incident on the driver's viewpoint 14. From the driver's viewpoint 14, a virtual image 10 corresponding to the image light 13 is formed and visible at a position visible through the display area 5 (Figure 1) of the display device 1 corresponding to the irradiation area of ​​the image light 13. In this embodiment, the projection of image light onto the display area 5 of the windshield 3 is described, but the projection unit that projects the image light may be a projection member other than the windshield 3.

[0052] Figure 6 shows the video display unit 200 of the display device 1. The light source unit 12 may also be called the backlight unit. The light source unit 12 includes a light source 20, a reflective mirror 21, a polarization conversion element 22, and a light guide unit 23, and may also include a diffuser plate 24. The reflective mirror 21 is used to reflect light from the light source 20 and adjust it to parallel light. The reflective surface of the reflective mirror 21 is a parabolic surface and may be asymmetrical with respect to the optical axis of the light emitted from the light source 20. The reflective mirror 21 may also be positioned eccentrically with respect to the light source 20. The reflective mirror 21 may also be called a reflector.

[0053] The polarization conversion element 22 is composed of a polarizing beam splitter (PBS) and a phase difference film (1 / 2λ). It separates incident light into S-polarized and P-polarized light, and then uses the phase difference film (1 / 2λ) to polarize either the separated S-polarized or P-polarized light, so that the randomly polarized light incident on the polarization conversion element 22 is emitted as linearly polarized light.

[0054] The light guide section 23 may also be called an optical transmission section. The light guide section 23 is configured to adjust the angle of incidence of light rays to the display panel 11, and in this example, it is configured using an optical reflecting section 23a having a prism shape (a jagged shape). The light guide section 23 may also be a prism sheet as an example. In this example, the light rays incident on the optical reflecting section 23a of the light guide section 23 are adjusted to a predetermined light distribution and reflected toward the display panel 11. The distribution of light incident on the display panel 11 can be adjusted by the shape of the reflective surface of the optical reflecting section 23a, the inclination of the reflective surface, the surface roughness, etc. In this structure, the optical axis of the light source 20 and the optical axis of the light incident on the display panel 11 are parallel or approximately parallel.

[0055] The light guide 23 is, for example, a resin member having a prism shape, and the prism-shaped portion that becomes the reflective surface is coated with an Al reflective film or the like. The light reflective portion 23a of the light guide 23 may be configured to have multiple inclinations on one surface in order to achieve more precise adjustment of reflected light. Furthermore, the reflective surface may be composed of multiple or multifaceted surfaces, or it may be composed of curved surfaces. When a large number of reflective surfaces and connecting surfaces are alternately formed in a sawtooth pattern on the light reflective portion 23a, the light incident on the light guide 23 is reflected on each reflective surface and directed toward the display panel 11, and further adjusted to a predetermined light distribution characteristic via the diffuser plate 24 before incident on the display panel 11. The diffuser plate 24 uniformly disperses the incident light from the light guide 23. The diffuser plate 24 has the effect of improving the brightness uniformity within the virtual image plane.

[0056] Furthermore, the video display unit 200 may have a configuration other than that shown in Figure 6, and may, for example, include a light source, an illumination optical system, a PBS or polarization separation element, and a reflective liquid crystal panel or LCOS.

[0057] Furthermore, the video display unit 200 is located inside the housing 210, as shown in Figure 7. More specifically, the video display unit 200 is housed in the housing 210 such that the display panel 11 is located on the upper surface 210a of the housing 210. In other words, the video light emitting side of the display panel 11 is positioned flush with the opening of the housing 210. Although not shown in the figure, a light-transmitting cover member that allows the video light emitted from the display panel 11 to pass through may be provided at this opening in the housing 210. The cover member may be made of transparent glass or resin. Also, since the video light emitting surface of the cover member may be touched by the user, a hard coat layer may be provided on the surface to allow for wiping away fingerprints and dirt. In addition, the cover member may have IR cut and UV cut functions by vapor deposition or film in order to reduce the energy of sunlight. The video display unit 200 is housed within the housing 210, and the surface of the display panel 11 provided by the video display unit 200 may be exposed to the outside on the upper surface 210a of the housing 210. When a display device 1 with such a configuration is placed on the dashboard 7, the surface of the cover member or the display panel 11 will be exposed to external light such as sunlight or streetlights. As a result, external light (reflected light) reflected from the surface of the cover member or the display panel 11 may enter the eye box (field of view) where the viewpoint 14 of the vehicle occupants, such as the driver, is located, potentially reducing the visibility of the virtual image 10.

[0058] Therefore, it is preferable that the display device 1 includes a light-shielding plate 300 that blocks at least a portion of the ambient light 800, 810 that enters the eye box (viewpoint range) 140 of the occupant (hereinafter referred to as the driver) of the vehicle 2, as shown in Figure 7 as an example. This makes it possible to suppress ambient light (reflected light) reflected by the cover member or the surface of the display panel 11 from entering the driver's eye box 140, even when the display device 1 is positioned exposed to the outside of the dashboard 7. Thus, the driver can clearly see the virtual image 10 even when relatively strong ambient light 800, 810 enters the vehicle through the windshield 3. The eye box (viewpoint range) 140 refers to the range of the viewpoint 14 in which the driver can see the virtual image 10 with a predetermined quality. In other words, if the driver's viewpoint 14 is within the eye box 140, the driver can see the virtual image 10 with a predetermined quality. Examples 1 to 3, which are examples of the installation of the light-shielding plate 300, will be described in more detail below.

[0059] <Example 1> Example 1 is an example in which the display device 1 is installed in a commercial vehicle such as a truck or bus. Figure 7 is a diagram showing an example of how the display device according to Example 1 is installed in a vehicle, and Figure 8 is a perspective view showing an example of a light-shielding plate according to Example 1.

[0060] As explained in Figure 5, in commercial vehicles such as trucks and buses, and in some passenger cars, the angle of the windshield 3 with respect to the Y-axis (the longitudinal direction or direction of travel of the vehicle 2) is sometimes around 45° to 90°. In vehicles 2 where the windshield 3 is in a so-called upright position, the top surface of the dashboard 7 is often inclined to face the windshield 3. As shown in Figure 7, the display device 1 is mounted on the dashboard 7 of a commercial vehicle, and the surface of the display panel 11 is inclined to face the windshield 3. Also, because the windshield 3 is in an upright position, the image light (light beam) 13 from the display panel 11 is emitted towards the windshield 3 rather than in the vertical direction (Z-axis direction). Furthermore, the image light 13 emitted from the display panel 11 is reflected by the windshield 3 and incident into the eye box 140 where the driver's viewpoint 14 is located (see Figures 7 and 5). As a result, the driver can see a virtual image 10 outside the windshield 3.

[0061] The light-shielding plate 300, which blocks external light (reflected light), is provided on the housing 210 of the display device 1 so as not to block the image light 13 emitted from the display panel 11. In Embodiment 1, the light-shielding plate 300 is provided on the upper surface 210a of the housing 210 of the display device 1 in the vertical direction of the vehicle 2. Alternatively, the light-shielding plate 300 is positioned between the opening of the display panel 11 or housing 210 and the driver in the front-rear direction of the vehicle 2. This allows the driver to see the virtual image 10 more clearly.

[0062] The light-shielding plate 300 is positioned to block ambient light (solid arrow in Figure 7) 800 that enters the eye box 140 along the optical path of the image light 13 emitted from the display panel 11. In other words, the light-shielding plate 300 is positioned to primarily block ambient light 800 that is reflected by the cover member or the display panel 11 and further reflected by the windshield 3 before entering the eye box 140. More specifically, the light-shielding plate 300 is positioned to block ambient light 800 that enters the lower end portion of the eye box 140 in the Z-axis direction. As a result, ambient light 800 entering the entire eye box 140 is blocked by the light-shielding plate 300.

[0063] Preferably, the light-shielding plate 300 is positioned to block the ambient light 800 before it enters the display panel 11. In the example shown in Figure 7, the housing 210 of the display device 1 is arranged such that the surface of the display panel 11 is inclined toward the windshield 3. In such an arrangement of the display device 1, in order to block the ambient light 800 before it enters the display panel 11, it is preferable that the light-shielding plate 300 be positioned on the driver side (rear side of the vehicle) of the display panel 11. That is, it is preferable that the light-shielding plate 300 be positioned between the display panel 11 and the user (e.g., the driver).

[0064] The orientation of the light shield 300 relative to the housing 210 is not particularly limited, but it is preferably oriented in line with the direction of emission of the image light 13 from the display panel 11. The light shield 300 is preferably provided from the upper surface 210a of the housing 210, along the direction of emission of the image light 13 emitted from the display panel 11. As described above, the image light (luminous flux) 13 from the display panel 11 is emitted at an angle toward the windshield 3 rather than in the vertical direction (Z-axis direction). Therefore, it is preferable that the light shield 300 is also provided in a state inclined toward the windshield 3 rather than in the vertical direction (Z-axis direction). In the example of Figure 7, the light shield 300 is fixed to the housing 210 in a state inclined toward the windshield 3 rather than in a direction perpendicular to the upper surface 210a of the housing 210. Furthermore, when positioned inclined with respect to the upper surface 210a of the housing 210, it is preferable that the light shield 300 be positioned close to the user (driver) side of the display panel 11 so as to cover the display panel 11. In other words, it is preferable that the light-shielding plate 300 is positioned so as to overlap a portion of the display panel 11 when viewed in the Z-axis direction. Furthermore, it is preferable that the angle of the light-shielding plate 300 (in this example, the angle with respect to the upper surface 210a of the housing 210) matches the emission angle of the image light emitted from the display panel 11. When the emission angle of the image light emitted from the display panel 11 and the angle of the light-shielding plate 300 are matched, the length of the light-shielding plate 300 can be made as short as possible.

[0065] Furthermore, the light-shielding plate 300 only needs to be able to block external light 800, and the fixing structure to the housing 210 is not particularly limited. As an example, as shown in Figure 8, the light-shielding plate 300 is provided with a pair of support walls 301 at both ends (both ends in the width direction of the vehicle 2), and is fixed to the upper surface 210a of the housing 210 in an inclined state by these support walls 301. The light-shielding plate 300 and the housing 210 are fixed together, for example, by adhesive, but may also be fixed by screws or the like. Also, the fixing position of the light-shielding plate 300 to the housing 210 does not necessarily have to be the upper surface 210a. For example, the support walls 301 of the light-shielding plate 300 may be fixed to the side of the housing 210 by screws or the like.

[0066] Furthermore, the material of the light shield 300 is not particularly limited, but for example, polyvinyl chloride, polycarbonate, etc. are preferably used. It is preferable that the surface of the light shield 300, in particular the surface on which the ambient light 800 is incident, is provided with an anti-reflective coating to suppress the reflection of ambient light 800. Moreover, it is preferable that the anti-reflective coating is provided not only on the surface of the light shield 300 but also on the outer surface of the housing 210. This further improves the visibility of the virtual image 10 to the driver.

[0067] The shape and size of the light-shielding plate 300 are not particularly limited, as long as it can block the ambient light 800. In this example, the surface shape of the light-shielding plate 300 is flat, but it may also be curved or wavy. However, it is preferable that the light-shielding plate 300 be made as large as possible without blocking the image light 13. For example, it is preferable that the height h1 of the light-shielding plate 300 (see Figure 8) be as high as possible without blocking the image light 13. This allows the light-shielding plate 300 to block the ambient light 800 more reliably. The light-shielding plate 300 may also be extendable. For example, the length of the light-shielding plate 300 may be adjustable within a range where the image light is not blocked in the direction of the image light emitted from the display panel 11. By adjusting the length of the light-shielding plate 300 according to the direction in which the ambient light 800 is incident, the ambient light 800 can be blocked more reliably.

[0068] Furthermore, in arrangement example 1, the light-shielding plate 300 is positioned to block external light (dotted arrow in Figure 7) 810 that is reflected off the surface of the cover member or display panel 11 and directly incident into the eye box 140. More specifically, the light-shielding plate 300 is positioned to block external light 800 incident on the upper end portion of the eye box 140 in the Z-axis direction. As a result, the light-shielding plate 300 can block external light 810 incident on the entire eye box 140.

[0069] Furthermore, the light-shielding plate 300 can also be said to function as a shielding plate that suppresses the driver's visibility of the surface of the display panel 11. When the display device 1 is placed on the dashboard 7, the driver may be able to directly see the image displayed on the display panel 11 along with the virtual image 10. In this case, there is a risk that the driver's visibility of the virtual image 10 will be reduced. However, in the configuration of arrangement example 1, the visibility of the display panel 11 is suppressed by the light-shielding plate 300. Therefore, the driver can see the virtual image 10 more clearly.

[0070] <Example 2> Example 2 is an example in which the display device 1 is installed in a passenger car. Figure 9 is a diagram showing an example of how the display device according to Example 2 is installed in a vehicle.

[0071] As explained in Figure 4, in passenger cars, the angle of the windshield 3 is sometimes around 20° to 45° with respect to the Y-axis (the front-to-back direction or direction of travel of the vehicle 2). In a vehicle 2 in which the windshield 3 is in a so-called horizontal position, the top surface of the dashboard 7 may be tilted to face the opposite side of the windshield 3, i.e., towards the driver (the rear of the vehicle 2), or it may be tilted to face the windshield 3. The display device 1 of Embodiment 2 shown in Figure 9 is mounted on the dashboard 7, and the surface of the display panel 11 is tilted to face the opposite side of the windshield 3. Also, because the windshield 3 is in a horizontal position, the image light (light beam) 13 from the display panel 11 is emitted towards the driver rather than in the vertical direction (Z-axis direction). Furthermore, the image light 13 emitted from the display panel 11 is reflected by the windshield 3 and incident into the eye box 140 where the driver's viewpoint 14 is located (see Figures 9 and 4). This allows the driver to see the virtual image 10 outside the windshield 3.

[0072] Furthermore, the light-shielding plate 300A according to Embodiment 2 is provided on the upper surface 210a of the housing 210 of the display device 1 so as not to obstruct the video light 13 emitted from the display panel 11. In other words, in the front-rear direction of the vehicle, the light-shielding plate 300A is positioned between the windshield 3 and the opening of the display panel 11 or the housing 210. Note that the light-shielding plate 300A itself is the same as the light-shielding plate 300 according to Embodiment 1. The arrangement of the light-shielding plate 300A according to Embodiment 2 will be described below, but explanations that overlap with those in Embodiment 1 will be omitted.

[0073] The light-shielding plate 300A is positioned, as in Embodiment 1, to block ambient light 800 that enters the eye box 140 along the optical path of the image light 13 emitted from the display panel 11. In other words, the light-shielding plate 300 is positioned to primarily block ambient light 800 that is reflected by the cover member or the display panel 11 and further reflected by the windshield 3 before entering the eye box 140. More specifically, the light-shielding plate 300A is positioned to block ambient light 800 that enters the lower end portion of the eye box 140 in the Z-axis direction. As a result, ambient light 800 entering the entire eye box 140 is blocked by the light-shielding plate 300A.

[0074] Furthermore, the light-shielding plate 300A is positioned to block the ambient light 800 before it enters the display panel 11. In the example shown in Figure 9, the housing 210 of the display device 1 is arranged such that the surface of the display panel 11 is tilted away from the windshield 3. In this arrangement of the display device 1, the light-shielding plate 300A is positioned closer to the windshield 3 (towards the front of the vehicle) than the display panel 11 in order to block the ambient light 800 before it enters the display panel 11. That is, the light-shielding plate 300A is positioned between the display panel 11 and the windshield 3. Also, the length of the light-shielding plate 300A can be made as short as possible when the emission angle of the image light emitted from the display panel 11 is matched with the angle of the light-shielding plate 300.

[0075] Furthermore, the light shield 300A is positioned in a orientation aligned with the direction of emission of the image light 13 from the display panel 11. In other words, the light shield 300A is installed on the upper surface 210a of the housing 210 so as to be inclined toward the driver than in the vertical direction (Z-axis direction). As described above, the image light (luminous flux) 13 from the display panel 11 is emitted at an angle toward the driver than in the vertical direction (Z-axis direction). Therefore, the light shield 300A is also installed in a state inclined toward the driver than in the vertical direction (Z-axis direction). In the example of Figure 9, the light shield 300A is fixed to the housing 210 in a state inclined toward the driver than in the direction perpendicular to the direction of the upper surface 210a of the housing 210. Furthermore, the light shield 300A is positioned close to the windshield 3 side of the opening of the display panel 11 or housing 210 so as to cover the upper part of the display panel 11.

[0076] In addition, in arrangement example 2, the light-shielding plate 300A is positioned to block not only the ambient light 800 but also the ambient light (dotted arrow in Figure 9) 810 that is reflected by the surface of the cover member or display panel 11 and directly enters the eye box 140.

[0077] <Example 3> Figure 10 shows an example of a configuration in which the display device according to Example 3 is mounted on a vehicle. Note that since Example 3 is a modification of Example 2, the differences from Example 2 will be explained in Example 3, and redundant explanations will be omitted.

[0078] The light-shielding plate 300A in the display device 1 according to Embodiment 2 was positioned on the windshield 3 side of the display panel 11. In contrast, the light-shielding plate 300B in the display device 1 according to Embodiment 3 is positioned on both the windshield 3 side and the driver side of the display panel 11. Specifically, the light-shielding plate 300B according to Embodiment 3 includes a first light-shielding plate 310 and a second light-shielding plate 320. The first light-shielding plate 310 is positioned on the windshield 3 side of the display panel 11, and the second light-shielding plate 320 is positioned on the driver side of the display panel 11. Specifically, in the longitudinal direction of the vehicle, the first light-shielding plate 310 is positioned between the opening of the display panel 11 or housing 210 and the windshield 3, and the second light-shielding plate 320 is positioned between the opening of the display panel 11 or housing 210 and the driver. The first light-shielding plate 310 has a configuration equivalent to the light-shielding plate 300A described in Embodiment 2, so its description is omitted here. Furthermore, the distance between the position where the first light-shielding plate 310 is placed in the housing 210 and the display panel 11 or the opening of the housing 210, and the distance between the position where the second light-shielding plate 320 is placed in the housing 210 and the display panel 11 or the opening of the housing 210, are not particularly limited and may be the same or different.

[0079] The second light-shielding plate 320, like the first light-shielding plate 310, is positioned in a direction aligned with the direction of emission of the image light 13 from the display panel 11. In other words, the second light-shielding plate 320 is provided so as to be inclined toward the driver from the upper surface 210a of the housing 210, rather than in the vertical direction (Z-axis direction). The second light-shielding plate 320 is mainly provided to block external light (dotted arrow in Figure 10A) 810 that is reflected by the cover member or the surface of the display panel 11 and directly incident into the eye box 140. The height of this second light-shielding plate 320 is preferably equal to or greater than the height of the first light-shielding plate 310. Although the external light 810 is mainly blocked by the first light-shielding plate 310, the presence of the second light-shielding plate 320 ensures that the external light 810 is blocked more reliably. Furthermore, the second light-shielding plate 320 can also be said to function as a shielding plate that suppresses the driver's visibility of the surface of the display panel 11. Therefore, by providing the second light-shielding plate 320 together with the first light-shielding plate 310 on the housing 210, the visibility of the virtual image 10 can be further improved. Also, if the angle of emission of the image light emitted from the display panel 11 is matched with the angle of the light-shielding plate 300, the length of the second light-shielding plate 320 can be minimized.

[0080] Furthermore, the display device 1 according to Embodiment 3, which includes a light-shielding plate 300 containing a first light-shielding plate 310 and a second light-shielding plate 320, can be mounted not only in passenger cars but also in commercial vehicles such as trucks and buses. As shown in Figure 10B as an example, the display device 1 according to Embodiment 3 can be mounted on the dashboard 7 of a vehicle 2 with the windshield 3 raised by rotating it 180° horizontally so that the second light-shielding plate 320 is positioned on the windshield 3 side of the display panel 11. In other words, the display device 1 according to Embodiment 3 can be used not only in passenger cars but also in commercial vehicles such as trucks and buses. This makes it possible to reduce the manufacturing cost of the display device 1.

[0081] Furthermore, as shown in Figures 11A and 11B, the greater the angle of the display panel 11 with respect to the horizontal direction (X direction, the front-to-back direction of the vehicle 2), the greater the height of the second light-shielding plate 320 may be relative to the first light-shielding plate 310. For example, as shown in Figure 11A, when the display panel 11 is positioned close to the vertical direction (Z direction, the up-and-down direction of the vehicle 2), that is, when the angle of the display panel 11 with respect to the horizontal direction is relatively large, the height of the second light-shielding plate 320 may be greater than the height of the first light-shielding plate 310. On the other hand, as shown in Figure 11B, when the display panel 11 is positioned close to the horizontal direction (X direction, the front-to-back direction of the vehicle 2), that is, when the display panel 11 is positioned along the horizontal direction, the height of the second light-shielding plate 320 may be lower than the height of the first light-shielding plate 310. In either case, the visibility of the virtual image 10 to the driver can be improved by blocking the ambient light 800 with the first light-shielding plate 310 and the second light-shielding plate 320.

[0082] Although the technology of this disclosure has been specifically described above based on embodiments, the technology of this disclosure is not limited to the embodiments described above and can be modified in various ways without departing from the gist of the invention. The embodiments described above can be modified by adding, deleting, or replacing components, except for essential components. Unless otherwise specified, each component may be singular or plural. Combinations of embodiments are also possible.

[0083] For example, in the above-described embodiment, a configuration in which the light-shielding plate is fixed on the housing of the display device was illustrated, but the light-shielding plate may be pivotably mounted on the housing. That is, the light-shielding plate may be mounted in such a way that its inclination angle with respect to the surface of the housing can be changed. Furthermore, the light-shielding plate may be configured to include, for example, a plurality of movable plates that can slide along the surface, and to be able to change its height from the housing.

[0084] The technology described in this embodiment provides an information display device that can display a good virtual image, reducing the driver's eye movement and contributing to safe driving, thereby preventing traffic accidents. This contributes to the United Nations' Sustainable Development Goal (SDG) 3, "Good Health and Well-being." [Explanation of Symbols]

[0085] 1. Display device (virtual image display device) 11 Display Panel 20 light source 200 Video display unit 210 cabinets 300,300A,300B Light shielding plate 310 First light-shielding plate 320 Second light-shielding plate

Claims

1. A display device that is placed on the dashboard of a vehicle, A light source device installed inside the enclosure, The housing is provided with a display panel that generates image light based on light emitted from the light source device, In the vertical direction, the housing is provided with a light-shielding plate that blocks at least a portion of the ambient light entering the driver's eye box of the vehicle. Display device.

2. In the display device according to claim 1, The light-shielding plate is primarily arranged to block external light entering the eye box along the optical path of the image light. Display device.

3. In the display device according to claim 1, The light-shielding plate is arranged to block external light from entering the display panel. Display device.

4. In the display device according to claim 1, The light-shielding plate is arranged along the direction of emission of the image light. Display device.

5. In the display device according to claim 1, If the surface of the display panel is positioned to be inclined toward the windshield side of the vehicle, the light shield is positioned at least between the display panel and the driver. Display device.

6. In the display device according to claim 1, If the surface of the display panel is positioned to be inclined toward the driver, the light shield is positioned at least between the display panel and the vehicle's windshield. Display device.

7. In the display device according to claim 1, The light-shielding plate includes a first light-shielding plate positioned between the display panel and the vehicle's windshield, and a second light-shielding plate positioned between the display panel and the driver. Display device.

8. In the display device according to claim 7, The second light-shielding plate also functions as a shielding plate that prevents the driver from viewing the surface of the display panel. Display device.

9. In the display device according to claim 7, When the display panel is positioned close to the vertical direction of the vehicle, the second light-shielding plate will be higher than the first light-shielding plate. Display device.

10. In the display device according to claim 1, When the emission angle of the image light emitted from the display panel matches the angle of the light-shielding plate, the length of the light-shielding plate is minimized. Display device.

Images