Display device

Abstract

This display device comprises: a light source that emits light; a light guide part that reflects the light from the light source; a display panel that emits image light on the basis of the light reflected by the light guide part; and a first circuit board. The first circuit board is disposed such that a part or the entirety thereof enters a space on the side opposite from a reflective surface of the light guide part.

Description

Display device

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

[0002] A display device or a virtual image display device is known that projects image 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.

[0003] Japanese Patent Application Laid-Open No. 3-169752

[0004] The display device is disposed, for example, on or inside the dashboard of the vehicle. When the display device is used, the driver can obtain information necessary for driving without moving the line of sight to the instrument panel incorporated in the dashboard, that is, the so-called instrument panel. On the other hand, sufficient consideration has not been given to the arrangement, brightness, influence from external light, and display of information of the display device.

[0005] An object of the present invention is to provide a more suitable display device or display technology.

[0006] According to a first aspect of the present invention, the following display device is provided. The display device includes a light source that emits light, a light guide unit that reflects light from the light source, a display panel that emits image light based on the light reflected by the light guide unit, and a first circuit board. The first circuit board is disposed so as to partially or entirely enter the space on the opposite side of the reflection surface of the light guide unit.

[0007] According to a second aspect of the present invention, the following display device is provided. The display device includes a light source that emits light, a light guide unit that reflects light from the light source, a display panel that emits image light based on the light reflected by the light guide unit, a first circuit board that performs control for displaying an image, a transmission unit that connects the first circuit board and the display panel and transmits a video signal, and a wireless communication unit or a GPS sensor that is disposed so as not to overlap the transmission unit in the vertical direction.

[0008] 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.

[0009] This figure shows an example of an in-vehicle system including a display device. This figure shows an example of a device used to acquire vehicle information. This is a block diagram showing an example of a display device. This figure shows an example of a configuration in which a display device is mounted on a vehicle. This figure shows an example of a configuration in which a display device is mounted on a vehicle. This figure shows an example of a light source structure for a display device. This figure shows an example of the arrangement of circuit boards and the like in a display device. This figure is for explaining the ease of assembly of a display device. This figure shows an example of the arrangement of circuit boards and the like in a structure in which light from a light-emitting indicator is emitted from the top side of a display device. This figure shows an example of a structure in which light from a light-emitting indicator is emitted from the front side (driver side) of a display device. This figure shows an example of a structure in which light from a light-emitting indicator is emitted from the side side of a display device. This figure shows an example of the arrangement of circuit boards and the like in a display device. This figure shows the arrangement of the operation input section in a display device. This figure shows the arrangement of the operation input section in a display device.

[0010] 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.

[0011] In explanations, when describing program-based processing, the focus may sometimes be on the program, functions, or processing units. However, the main 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 a CPU / MPU or GPU. Processing is not limited to software program processing; it can also be implemented using dedicated circuits. Applicable dedicated circuits include FPGAs, ASICs, CPLDs, etc.

[0012] 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.

[0013] Figure 1 shows an example configuration of an in-vehicle system including a display device 1 or a virtual image display device. 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".

[0014] The display device 1 acquires vehicle information 4 from cameras and various sensors installed in various parts of the vehicle 2. The display device 1 may also be called a virtual image display device. The various sensors, for example, detect various events that occur in the vehicle 2 and periodically detect the values ​​of various parameters related to driving conditions. It can also acquire road information from a navigation device 6 (car navigation system), external devices 400, terminal devices 410 (e.g., mobile terminals), and GPS (Global Positioning System) information. The GPS may be installed in the vehicle 2, or it may be installed in the external devices 400 or terminal devices 410.

[0015] Vehicle information 4 includes, for example, vehicle 2's speed information, gear information, steering angle information, lamp illumination information, ambient light information, distance information, infrared information, engine ON / OFF information, camera image information, accelerometer / gyro information, GPS (Global Positioning System) information, navigation information, vehicle-to-vehicle communication information, and vehicle-to-infrastructure communication information. Camera image information includes in-vehicle camera image information and exterior camera image information. GPS information includes latitude and longitude as well as current time information. Vehicle information 4 also includes input information from the driver.

[0016] 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 are able to 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 using, for example, a CAN (Controller Area Network) or LIN (Local Interconnect Network) interface. Alternatively, the display device 1 and the controller 100 of the vehicle 2 may communicate via the information transmission path using an in-vehicle Ethernet or the like. Other connection configurations may also be adopted. For example, when transmitting all information, including video information, through a single information transmission path, the connection between the controller 100 on the vehicle 2 side (source of video information, etc.) and the display device 1 (in other words, the connection configuration of the information transmission path) may be FPD-Link III, GMSL (Gigabit Multimedia Serial Link), etc.

[0017] The in-vehicle system is configured such that the controller 100 controls the vehicle 2 based on data input and output and is connected to the display device 1. The in-vehicle system can communicate with the outside of the vehicle 2 via a communication device or network. Examples of communication with the outside of the vehicle 2 include direct communication and indirect communication. Direct communication is used internationally as ITS (Intelligent Transport System) communication, while indirect communication is performed, for example, via a server to an external device 400 or terminal device 410. The in-vehicle system can send and receive data or information to, for example, a server 700 connected to the network 500 via a relay station 600 on the network 500. The in-vehicle system may also communicate with infrastructure such as external devices and terminals installed on the road on which the vehicle 2 travels.

[0018] 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 the vehicle 2 may also have the function of controlling the display device 1.

[0019] The vehicle speed sensor 901 detects the speed of the 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.

[0020] 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.

[0021] 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 reach temperatures similar to those inside the dashboard.

[0022] 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.

[0023] The vehicle-to-infrastructure wireless transceiver 915 generates vehicle-to-infrastructure communication information through vehicle-to-infrastructure communication between the 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 the vehicle 2 and other surrounding vehicles. The wired wireless communication unit 917 for mobile terminal-to-vehicle communication is a device that acquires information via wired or wireless communication from devices connected to an LTE (Long Term Evolution) network (e.g., Wi-Fi devices). 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.

[0024] 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.

[0025] On the other hand, the external camera 920 captures images of the surroundings, such as the front and rear of the 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 may also include, for example, a drive recorder that records the situation while driving.

[0026] 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.

[0027] 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 switches 911 are used to generate driver operation information for steering wheel switches, etc.

[0028] Furthermore, the video generation unit 910 generates video information based on vehicle information 4 acquired by the controller 100 of the vehicle 2. It can also generate video information based on external information.

[0029] Figure 3 is a block diagram of the display device 1. The display device 1 mainly controls the display of projected images (virtual images) on the display device 1.

[0030] 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.

[0031] The control unit 1010 is specifically a microcontroller unit (MCU), a CPU (Central Processing Unit), etc. 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, but may also be implemented using an ECU (Electronic Control Unit) or other semiconductor devices. The configuration shown in Figure 3 may, for example, be a control unit mounted inside the housing of the display device 1, or a control unit mounted outside the housing. Also, the display device 1 can be controlled by a controller in the vehicle 2 or an external device without implementing the control unit 1010 in the display device 1.

[0032] 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.

[0033] The volatile memory 1012 operates by unpacking 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.

[0034] 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.

[0035] 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 of the vehicle 2, using a mechanism such as CAN or an 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.

[0036] 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 the 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.

[0037] 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 the volatile memory 1012.

[0038] 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.

[0039] 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.

[0040] The external power input unit 1018 inputs power from the outside and supplies the necessary power to each part of the display device 1 shown in FIG. 3.

[0041] The speaker 1019 emits sound based on the audio data stored in the volatile memory 1012, the non-volatile memory 1011, or the storage unit 1013.

[0042] The light-emitting indicator 1020 emits light by means of a light-emitting element or the like, and can notify the user of the state of the display device 1 by the light-emitting timing or the light-emitting color of the light-emitting element.

[0043] The display driver 1021 drives each display element (pixel) included in the display panel 11 based on the video data. As a result, the video display unit or the video display unit 200 creates and displays a video for projection onto the display area 5 based on the video data. The display driver 1021 can be constituted by, for example, a circuit mounted on a substrate.

[0044] The light source driving unit 1022 drives the light source 20 to generate light source light. Based on the driving from the light source driving unit 1022, the light source 20 generates light source light and supplies it to the display panel 11. The light source 20 is adjusted or controlled using the light source driving unit 1022, which is a driver used for driving the light source, based on the vehicle information 4 received via the communication unit 1014, or information from a terminal device or the like.

[0045] Also, 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 display panel 11 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 that the display panel 11 may be burned out, the brightness of the light source 20 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.

[0046] Each part of FIG. 3 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 nonvolatile memory 1011, a volatile memory 1012, a storage unit 1013, and a video processing unit 1016, respectively, but the above processing may be made to function by one memory.

[0047] Next, the video display unit 200 will be specifically described. The video display unit (video display unit) 200 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) based on the video data. The video display unit may also be referred to as a projection type video display device or a projector. The video display unit 200 includes a light source 20 and a display panel 11 such as a liquid crystal display (LCD) having a video display element.

[0048] The light source 20 functions as a backlight source of the display panel 11. 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. As the semiconductor light source element, an LED (Light Emitting Diode) element is typically used. The light source 20 may have a configuration in which a plurality of light sources are arranged. The backlight unit is configured using the light source 20 and the like.

[0049] The display panel 11 generates and emits video light obtained by modulating a video based on the light source light. That is, the display panel 11 forms and displays a video on the display screen based on the video data, and generates and emits video light corresponding to the video based on the light from the light source 20. The video data in the present embodiment will be described as the video data input from the video processing unit 1016. The display panel 11 forms a video for projection onto the display area 5 by modulating 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).

[0050] 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 may be used, or a means of using a micro-electromechanical system may be used.

[0051] Figures 4 and 5 show examples of configurations in which the display device 1 is mounted on a vehicle 2. Figure 4 shows an example of mounting the display device 1 on 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 raised. 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] Next, an example of the structure of a display device will be described with reference to Figure 7. As shown in Figure 7, a light source 20, a reflective mirror 21, and a light guide unit 23 are arranged inside the housing 15 of the display device 1. The light source 20 is positioned facing the reflective mirror 21 so as to emit light from the light source to the reflective mirror 21. The reflective mirror 21 is positioned to reflect the light from the light source 20 and cause the reflected light to enter the light guide unit 23. The light guide unit 23 is positioned to emit the light from the light source entering from the reflective mirror 21 toward the display panel 11.

[0059] Here, as shown in the figure, as an example, the light source 20 may be positioned to emit light downwards in the vertical or longitudinal direction of the vehicle 2. The reflective mirror 21 may be positioned in the direction of light emission from the light source 20. The light guide unit 23 may be positioned in the direction of light emission from the light reflected by the reflective mirror 21 (for example, in the front-to-back direction of the display device 1). In this embodiment, the light guide unit 23 may be positioned to emit light upwards in the vertical direction of the vehicle 2. The display panel 11 may be positioned above the light guide unit 23.

[0060] The display panel 11 is located in the housing 15. A light-transmitting cover that allows the video light emitted from the display panel 11 to pass through may be provided at the opening of the housing 15. Alternatively, the display panel 11 may be positioned flush with the opening of the housing 15. In this case, the opening of the housing 15 is the surface from which the video light is emitted.

[0061] The housing 15 has a heat sink 31 positioned near the light source 20. In the vertical direction of the vehicle 2 or housing 15, the heat sink 31 is positioned above the light source 20 or on the side opposite to the direction of light emission from the light source 20. The housing 15 also has an opening O1 for circulating air to cool the heat sink 31. Inside the housing 15, a light-shielding plate 32 is provided to prevent light from the light source 20 inside the housing 15 from leaking through the opening O1. In other words, the inside of the housing 15 is divided into a bright region where there is an optical path for the light emitted from the light source 20 and a dark region where there is no optical path, and the boundary between the two regions is formed by the heat sink 31 and the light-shielding plate 32. In this embodiment, the light-shielding plate 32 is positioned between the display panel 11 and the heat sink 31.

[0062] Furthermore, the shape of the housing 15 may be altered by bulging it out, taking into account the size of the heatsink 31. For example, as shown in the figure, the upper part of the housing 15 may be bulged out, taking into account the vertical size of the heatsink 31.

[0063] The housing 15 contains a main board or first board 35 and a sub-board or second board 37. These boards are circuit boards, and each part shown in Figure 3 is a board on which circuits are mounted. Therefore, in this embodiment, the main board 35 may be called the first circuit board, and the sub-board 37 may be called the second circuit board. The main board 35 is positioned inside the housing 15 such that a part of it enters the space opposite the reflective surface of the light guide 23. The main board 35 is positioned at the bottom of the housing 15 in the vertical direction. By positioning the main board 35 in this way, the space inside the housing 15 is effectively utilized, the front-to-back length of the housing 15 of the display device 1 is shortened, and the display device 1 can be made smaller. As the display device 1 is made smaller, the range in which the display device 1 can be installed is widened. Therefore, it becomes easier to place the display device 1 in a position that is easily visible to the user, improving user visibility.

[0064] Here, the main board 35 implements a configuration for controlling the video display of the display panel 11. The main board 35 and the display panel 11 are connected using an FPC (Flexible Printed Circuits) or a transmission unit 36, and a video signal is transmitted to the display panel 11 via the FPC or transmission unit 36. In this embodiment, the main board 35 and the display panel 11 are arranged parallel or substantially parallel in the vertical direction of the housing 15 or vehicle 2. Alternatively, the FPC or transmission unit 36 ​​may be arranged to connect the main board 35 and the display panel 11 while running along the side surface 15a of the housing 15, away from the light guide unit 23. In other words, the FPC or transmission unit 36 ​​may be folded back and arranged between the main board 35 and the sub-board 37 while running along the side surface 15a of the housing 15. The FPC or transmission unit 36 ​​may have a structure that has a length that connects the main board 35 and the display panel 11 while running along the side surface 15a of the housing 15.

[0065] In the vertical direction of the housing 15 or vehicle 2, a sub-board 37 may be arranged inside the housing 15, above the main board 35 and FPC 36. The sub-board 37 may be arranged above the main board 35. The size of the main board 35 is larger than the size of the sub-board 37. For example, the circuitry of the wireless communication unit 1015 may be mounted on the sub-board 37. To obtain stable communication, it is desirable that the wireless communication unit 1015 be arranged in a position with few obstructions that block radio waves, i.e., between the sub-board 37 and the housing 15. Furthermore, by arranging the sub-board 37 between the wireless communication unit 1015 and the FPC or transmission unit 36, noise generated from the FPC or transmission unit 36 ​​is shielded by the sub-board 37, allowing the wireless communication unit 1015 to communicate stably. Here, an opening may be formed in the housing 15 above the wireless communication unit 1015. A radio wave-transmitting cover may also be provided in this opening. A specific example of arrangement on the sub-board 37 will be described in detail later. Note that the sub-board 37 may be omitted, and the configuration that would normally be mounted on the sub-board 37 may be mounted on the main board 35. However, as shown in Figure 7, by stacking the main board 35 and the sub-board 37 in a two-tiered structure, it is possible to shorten the length of the device in the front-to-back direction even with the same board area. This makes it possible to miniaturize the display device 1. Note that the reference numeral 1030 in Figure 7 indicates an example where a GPS sensor 1030 is mounted. The GPS sensor 1030 will be described later.

[0066] Next, the ease of assembly during the manufacturing of the display device will be described with reference to Figure 8. As shown in the figure, the housing 15 can be configured to include an upper housing section 15e and a lower housing section 15f. For example, the assembler places the light source 20, reflective mirror 21, light guide section 23, heat sink 31, and main board 35 in the lower housing section 15f. The assembler also places the display panel 11 and sub-board 37 in the upper housing section 15e. The assembler also connects the FPC 36 and places the light shielding plate 32. The assembler then assembles the upper housing section 15e and the lower housing section 15f to complete the display device 1. The upper housing section 15e and the lower housing section 15f may be connected by a hinge, and the housing 15 may have a structure that allows it to be opened and closed. Furthermore, the ease of assembly is improved by setting the length of the FPC 36 to a length that connects the main board 35 and the display panel 11 while running along the side surface 15a of the housing 15.

[0067] Next, an example of the configuration on the sub-board 37 will be described with reference to Figure 9. As shown in the figure, it is preferable that the circuit of the wireless communication unit 1015 be arranged on the sub-board 37 so as not to overlap with the FPC 36 in the vertical direction. Furthermore, it is preferable that the circuit of the wireless communication unit 1015 be arranged on the sub-board 37 so as not to overlap with the display driver 1021 on the main board 35 and the video signal line L connecting the display driver 1021 and the FPC 36 in the vertical direction. By ensuring that the configuration for transmitting video signals does not overlap with the configuration in the vertical direction in this way, interference with the communication of the wireless communication unit 1015 due to noise generated from the FPC 36 and the video signal line L is suppressed. On the other hand, if the circuit of the wireless communication unit 1015 is arranged on the main board 35, interference with the communication of the wireless communication unit 1015 due to noise generated from the video signal line L can also be suppressed by attaching a radio wave absorbing member to block the space between the video signal line L on the main board 35 and the wireless communication unit 1015. The video signal line L may also be referred to as a connection part.

[0068] In this example, the main substrate 35 is positioned such that a portion of it extends into the space opposite the reflective surface of the light guide 23. However, it is sufficient for at least a portion of the main substrate 35 to extend into the space; for example, the entire main substrate 35 may extend into the space.

[0069] Next, with reference to Figures 10A and 10B, another example of the structure of the display device will be described. As shown in Figure 10A, the lower surface of the housing 15 may include a bottom surface 15b and an inclined surface 15c. That is, the housing 15 may have a structure in which the inclined surface 15c extends from the bottom surface 15b to the side surface 15a. For example, an inclined surface 15c may be formed on the lower surface of the housing 15 on the opposite side of the reflective surface of the light guide unit 23. The main circuit board 35 may be positioned such that at least a part of the main circuit board 35 fits into the space on the opposite side of the reflective surface of the light guide unit 23. As shown in Figure 10B, by forming an inclined surface 15c on the housing 15 and positioning the display device 1 so that this inclined surface 15c is aligned with the surface of the installation location (for example, the surface of the dashboard 7), it becomes possible to design the display panel 11 considering the angle with respect to the installation surface. In other words, when the display device 1 or display panel 11 is positioned at an angle relative to the dashboard 7, the display device 1 can be positioned without interfering with the dashboard 7 by having an inclined surface 15c of the housing 15. This allows the display device 1 to be positioned lower in the vertical or longitudinal direction of the vehicle 2, thereby ensuring a wider field of view for the driver.

[0070] Furthermore, as shown in Figure 11A, a sub-board 37 may be arranged inside the housing 15. Here, for example, the sub-board 37 may be arranged so as not to overlap with the main board 35 in the vertical direction. Also, the wireless communication unit 1015 may be arranged so as not to overlap with the FPC 36, the display driver 1021, and the video signal line L in the vertical direction. In this example of the display device structure, the FPC 36 may be arranged to connect the main board 35 and the display panel 11 while running along the side surface 15a of the housing 15. The FPC 36 may have a length that connects the main board 35 and the display panel 11 while running along the side surface 15a of the housing 15.

[0071] Next, we will explain an example of the arrangement of the light-emitting indicator with reference to Figures 12-14.

[0072] As shown in Figure 12, the light-emitting indicator 1020 may be positioned to emit light to the outside from the upper side of the housing 15 (the side on which the display panel 11 is placed). Here, the light-emitting indicator 1020 may be mounted on the sub-board 37. An opening O2 through which light passes is formed above the light-emitting indicator 1020. A light-transmitting cover or diffuser plate may be provided in this opening O2. In this arrangement example, the light emitted from the light-emitting indicator 1020 is reflected by the windshield 3 and directed towards the driver, allowing the driver to see the light-emitting indicator 1020 as a virtual image. Therefore, the driver can simultaneously see the virtual image 10 displayed by the display device 1 and the virtual image of the light-emitting indicator 1020. This reduces the driver's eye movement required to check the light-emitting indicator 1020, enabling safer driving.

[0073] As shown in Figure 13, the light-emitting indicator 1020 may be positioned to emit light to the outside from the front side (driver side) of the housing 15. Here, the light-emitting indicator 1020 may be mounted on the main board 35. An opening through which light passes is formed on the front side of the housing 15, and a light guide 39 may be positioned to guide light from the light-emitting indicator 1020 toward the opening. A light-transmitting cover may be provided over this opening. In this arrangement example, reflection of the light-emitting indicator 1020 on the windshield 3 can be suppressed, improving the driver's forward visibility.

[0074] As shown in Figure 14, the light-emitting indicator 1020 may be positioned to emit light to the outside from the side of the housing 15 (in this example, the left and right sides). Here, the light-emitting indicator 1020 may be mounted on the main board 35. Furthermore, openings through which light passes are formed on the left and right sides of the housing 15, and a light guide 39 may be positioned to guide light from the light-emitting indicator 1020 toward these openings. A light-transmitting cover may be provided over these openings. In this arrangement example, the worker mainly installing the display device 1 on the vehicle 2 checks the light-emitting indicator 1020 to confirm the connection status of the display device 1, etc. In this case, it is desirable to position the light-emitting indicator 1020 in a location that is not visible to the driver, i.e., on the side of the housing 15, so that the driver's attention is not distracted by the light-emitting indicator 1020.

[0075] In Figure 3, the display device 1 may include, for example, a GPS sensor 1030 (not shown in Figure 3) connected to the control unit 1010. In this case, the arrangement of the GPS sensor in the display device 1 can be done in the same way as the arrangement of the wireless communication unit 1015 described above. For example, in Figure 7, the GPS sensor 1030 may be mounted on a sub-board 37. In order to receive stable satellite signals, it is desirable that the GPS sensor 1030 be placed in a position with few obstructions that block radio waves, that is, between the sub-board 37 and the housing 15. Furthermore, by placing the sub-board 37 between the GPS sensor 1030 and the FPC or transmission unit 36, noise generated from the FPC or transmission unit 36 ​​is shielded by the sub-board 37, and the GPS sensor 1030 can stably receive satellite signals. Here, an opening may be formed in the housing 15 at a position above the GPS sensor 1030. A radio wave-transmitting cover may also be provided in this opening. Furthermore, in the example of the configuration on the sub-board 37 shown in Figure 9, it is preferable that the GPS sensor 1030 is arranged on the sub-board 37 so as not to overlap with the FPC 36 in the vertical direction. It is also preferable that the GPS sensor 1030 is arranged on the sub-board 37 so as not to overlap with the display driver 1021 on the main board 35 and the video signal line L connecting the display driver 1021 and the FPC 36 in the vertical direction. By ensuring that the configuration does not overlap with the video signal transmission configuration in the vertical direction in this way, interference with the reception of satellite signals by the GPS sensor 1030 due to noise generated from the FPC 36 and the video signal line L is suppressed. On the other hand, if the circuit of the GPS sensor 1030 is arranged on the main board 35, it is also possible to suppress interference with the reception of satellite signals by the GPS sensor 1030 due to noise generated from the video signal line L by attaching a radio wave absorbing member so as to block the space between the video signal line L on the main board 35 and the GPS sensor 1030. Furthermore, when both the wireless communication unit 1015 and the GPS sensor 1030 are placed on the sub-board 37, it is desirable to place them at separate locations on the sub-board 37, as shown in Figure 9. This is to suppress mutual interference between the reception of satellite signals from the GPS sensor 1030 and the communication from the wireless communication unit 1015.Specifically, in the example shown in Figure 9, the GPS sensor 1030 and the wireless communication unit 1015 are positioned at opposite ends in the X direction on the sub-board 37 in order to keep them separate. Similarly, in the example shown in Figure 11A, the GPS sensor 1030 and the wireless communication unit 1015 are positioned at opposite ends in the Y direction on the sub-board 37 in order to keep them separate. Thus, it is desirable that the GPS sensor 1030 and the wireless communication unit 1015 be positioned on the sub-board 37 at opposite ends in a predetermined direction. When the GPS sensor 1030 is placed, it may be placed at the position shown in Figures 8, 11B, 12, and 13. When the circuit board is constructed using only the main board 35 without the sub-board 37, it is desirable that the GPS sensor 1030 and the wireless communication unit 1015 be positioned on the main board 35 at opposite ends in a predetermined direction.

[0076] The display panel 11 only needs to be able to properly emit video light towards the windshield 3, and the orientation of the display device 1 when installed can be determined as appropriate.

[0077] Figure 15 shows an example of a configuration in which a display device is mounted on a vehicle. Note that Figure 15 is a modified version of Figure 7, so in Figure 15, the differences from Figure 7 will be explained, and redundant explanations will be omitted.

[0078] Next, with reference to Figures 5 and 15, another example of the structure of the display device will be described. As shown in Figure 5, when the display device 1 is installed in a light super-height wagon, truck, or bus where the windshield or windshield 3 is raised, the display device 1 makes it difficult for the driver to see below, or in other words, the area immediately surrounding the vehicle, thus compromising driving safety. In contrast, as shown in Figure 15, in the display device 1 of this embodiment, the main board 35 and the sub-board 37 are positioned at an angle to the display panel 11, creating a structure that does not easily obstruct the driver's line of sight.

[0079] Specifically, the housing 15 has a first housing portion 15P1 and a second housing portion 15P2, with the first housing portion 15P1 inclined relative to the second housing portion 15P2, or in other words, the second housing portion 15P2 inclined relative to the first housing portion 15P1. The main board (first circuit board) 35 and the sub-board (second circuit board) 37 are arranged in the first housing portion 15P1, while the heat sink 31, light source 20, display panel 11, etc. are arranged in the second housing portion 15P2. In this embodiment, the first housing portion 15P1 is arranged on the dashboard 7, and the second housing portion 15P2 is arranged inclined relative to the dashboard 7. When arranged in this manner, in the vertical direction of the vehicle 2, the main board 35 and the sub-board 37 are housed in the first housing portion 15P1 parallel or substantially parallel and are located on the driver's side. Furthermore, since the display panel 11 is positioned closer to the main board 35 than the light source 20, the length of the FPC connecting the main board 35 and the display panel 11 is short, resulting in a compact design and good ease of assembly.

[0080] The structure shown in Figure 15 ensures the driver's field of view. Furthermore, the operation input section 1070, such as buttons, located on the sub-board 37 is positioned in a location easily visible to the driver, resulting in a structure with excellent operability. The illuminance sensor 905 is positioned on a surface parallel to the display panel 11, that is, on the surface facing the windshield 3, making it suitable for acquiring ambient light information. Based on the ambient light information in front of the driver acquired by the illuminance sensor 905, the control unit 1010 (Figure 3) controls the output of the light source 20, thereby displaying the image at an appropriate brightness according to the ambient light information, improving the driver's visibility. In addition, if the intensity of ambient light (mainly sunlight) incident on the display panel 11 is strong and there is a risk of damage to the display panel 11, the output of the light source 20 can be temporarily suppressed to prevent damage to the display panel 11.

[0081] In Figure 15, the first housing section 15P1, which houses the main board 35 and sub-board 37, is located on the driver's side, and the second housing section 15P2, which houses the light source 20 and other components, is located on the windshield 3 side. However, this arrangement may be reversed. When the first housing section 15P1 is located on the windshield 3 side and the second housing section 15P2 is located on the driver's side, the light source 20 is located on the driver's side, and the display panel 11 is located on the first housing section 15P1 side.

[0082] Next, another arrangement example of the operation input unit 1070, such as buttons, will be described. In Figure 16A, the operation input unit 1070 is positioned below the housing 15 of the display device 1 in the vertical direction of the vehicle 2. Since the operation input unit 1070, such as buttons, needs to move in response to input, a space is required between the operation input unit 1070 and the housing 15. As a result, dust may enter through this gap, potentially causing malfunctions in the display device 1. In the arrangement example in Figure 16A, since the operation input unit 1070 is positioned lower down, dust is less likely to enter through the gap, improving the reliability of the display device 1. Furthermore, by concealing the operation input unit 1070 from the driver, a display device 1 with a high aesthetic design can be realized.

[0083] In Figure 16B, the operation input unit 1070 is located on the side of the housing 15. This arrangement allows for a balance between operability and aesthetic design. The driver can see the operation input unit 1070 to some extent, while concealing it to the extent that it does not detract from the aesthetic design. The operation input unit 1070 may also be provided on the sub-board 37. Furthermore, the arrangement examples of the operation input unit 1070 shown in Figures 16A and 16B are not limited to the structure of the display device 1 shown in Figure 15, but may be any of the aforementioned structural examples of the display device 1.

[0084] Although embodiments have been described above, the present invention is not limited to the embodiments described above, and includes various modifications and equivalent configurations within the spirit of the attached claims. For example, the embodiments described above are described in detail for the purpose of explaining the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to having all the configurations described. Also, for example, some of the configurations of the embodiments may be added, deleted, or replaced with other configurations.

[0085] The technology described in this embodiment provides an information display device (head-up display device) that can display a good virtual image and reduce the driver's eye movement, thereby contributing to safe driving and preventing traffic accidents. This contributes to the United Nations' Sustainable Development Goal (SDG), specifically "Goal 3: Ensure good health and well-being for all."

[0086] 1 Display device (virtual image display device) 11 Display panel 20 Light source 23 Light guide unit 35 Main board (first circuit board) 36 FPC (transmission unit) 37 Sub board (second circuit board) 1015 Wireless communication unit 1020 Light-emitting indicator (indicator light source) 1021 Display driver 1030 GPS sensor L Video signal line (connection unit)

Claims

1. A display device comprising: a light source that emits light; a light guide that reflects light from the light source; a display panel that emits image light based on the light reflected by the light guide; and a first circuit board, wherein the first circuit board is arranged such that part or all of it is contained within the space opposite the reflective surface of the light guide.

2. A display device according to claim 1, comprising a housing that houses the light source, the light guide unit, and the first circuit board, wherein the space is formed between the light guide unit and the housing.

3. A display device according to claim 1, comprising: a transmission unit that connects the first circuit board and the display panel and transmits video signals; and a second circuit board that is positioned above the first circuit board and includes a wireless communication unit used for wireless communication, wherein the wireless communication unit is positioned so as not to overlap with the transmission unit in the vertical direction of the housing.

4. A display device according to claim 3, wherein the first circuit board includes a display driver and a connection unit for connecting the display driver and the transmission unit, and the wireless communication unit is arranged so as not to overlap with the display driver and the connection unit in the vertical direction.

5. A display device according to claim 1, comprising: a transmission unit that connects the first circuit board and the display panel and transmits video signals; and a second circuit board that is positioned above the first circuit board and includes a GPS sensor, wherein the GPS sensor is positioned so as not to overlap with the transmission unit in the vertical direction.

6. A display device according to claim 5, wherein the first circuit board includes a display driver and a connection part for connecting the display driver and the transmission unit, and the GPS sensor is arranged so as not to overlap with the display driver and the connection part in the vertical direction.

7. A display device according to claim 2, wherein the housing includes an inclined surface that slopes from the bottom to the side.

8. A display device according to claim 2, comprising an indicator light source housed in a housing that indicates the state of the display device, wherein the housing has an opening through which light emitted by the indicator light source passes.

9. A display device according to claim 1, comprising a transmission unit that connects the first circuit board and the display panel and transmits a video signal, wherein the transmission unit has a length that connects the first circuit board and the display panel while running along the side surface of the housing.

10. A display device comprising: a light source that emits light; a light guide that reflects light from the light source; a display panel that emits image light based on the light reflected by the light guide; a first circuit board that performs control for displaying an image; a transmission unit that connects the first circuit board and the display panel and transmits an image signal; and a wireless communication unit or GPS sensor that is arranged so as not to overlap with the transmission unit in the vertical direction.

11. A display device according to claim 10, comprising the light source, the light guide unit, the first circuit board, and a housing that houses the wireless communication unit or the GPS sensor inside.

12. A display device according to claim 10, wherein the first circuit board includes a display driver and a connection part for connecting the display driver and the transmission unit, and the wireless communication unit or the GPS sensor is arranged so as not to overlap with the display driver and the connection part in the vertical direction.

13. A display device according to claim 10, wherein both the wireless communication unit and the GPS sensor are arranged on the first circuit board, and the wireless communication unit and the GPS sensor are arranged on the first circuit board at positions opposite to each other in a predetermined direction.

14. A display device according to claim 11, comprising an indicator light source housed in a housing that indicates the state of the display device, wherein the housing has an opening through which light emitted by the indicator light source passes.

15. A display device according to claim 10, wherein the transmission unit has a length that connects the first circuit board and the display panel along the side surface of the housing.

16. A display device according to claim 1, comprising a housing, wherein the housing comprises a first housing portion for housing the first circuit board, and a second housing portion for housing the light source and the light guide portion.

17. A display device according to claim 16, wherein the second housing portion is arranged at an inclination with respect to the first housing portion.

18. A display device according to claim 17, comprising: a transmission unit that connects the first circuit board and the display panel and transmits video signals; and a second circuit board that is positioned above the first circuit board and includes a wireless communication unit used for wireless communication, wherein the wireless communication unit is positioned so as not to overlap with the transmission unit in the vertical direction of the first housing.

19. A display device according to claim 17, comprising: a transmission unit that connects the first circuit board and the display panel and transmits video signals; and a second circuit board that is positioned above the first circuit board and includes a GPS sensor, wherein the GPS sensor is positioned so as not to overlap with the transmission unit in the vertical direction.

Images