Display device

Abstract

The purpose of the present invention is to provide a more suitable display device. The present invention contributes to "9. Industry, innovation and infrastructure" of the Sustainable Development Goals.　This display device comprises: a display panel which is capable of outputting image light; a light source device which includes a light source and which outputs, to the display panel, light emitted from the light source; a heat dissipation unit which is connected to the light source; and a housing in which the light source device and the heat dissipation unit are disposed and on the upper side of which the display panel is installed. In the housing, an exhaust port is formed on the airflow downstream side where heat exchange is performed with the heat dissipation unit, and an intake port is formed on the airflow upstream side. An opening region of the exhaust port is smaller than that of the intake port.

Description

Display device 【0001】 The present invention relates to a display device, a virtual image display device, display technology, 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, 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, information display, etc. 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 an aspect of the present invention, the following display device is provided. The display device includes a display panel capable of emitting image light, a light source device including a light source that emits light emitted by the light source to the display panel, a first heat radiation part connected to the light source, and a housing in which the light source device and the first heat radiation part are disposed inside and the display panel is installed on the upper side. In the housing, an exhaust port is formed on the downstream side of the air flow that exchanges heat with the first heat radiation part, an intake port is formed on the upstream side of the air flow, and the opening area of the exhaust port is smaller than the opening area of the intake port. 【0007】 According to the present invention, a more suitable display device or display technology can be provided. In addition, problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments. 【0008】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 light source structure for a display device. This figure shows an example of the configuration of a display device according to the first embodiment. This figure shows an example of the configuration of a display device according to a modification of the first embodiment. This figure shows an example of the configuration of a display device according to the second embodiment. This figure shows an example of the configuration of a display device according to the third embodiment. This figure shows an example of the configuration of a display device 1 according to the fourth embodiment. This is a side view showing an example of the configuration of a display device 1 according to the fifth embodiment. This is a top view showing an example of the configuration of a display device 1 according to the fifth embodiment. This figure shows the characteristics of a latent heat storage material. This figure shows an example of the temperature change of the display panel. This is a top view showing a first configuration example of a display device according to the sixth embodiment. This is a cross-sectional view showing a first configuration example of a display device according to the sixth embodiment. This is a top view showing a second configuration example of a display device according to the sixth embodiment. This is a cross-sectional view showing a second configuration example of a display device according to the sixth embodiment. This is an enlarged view of the fine wiring in the sixth embodiment. 【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 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. 【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 1. With respect to the vehicle (or vehicle) 2 and the driver, the horizontal direction X is the left-right direction, the lateral direction of the vehicle 2, or the width direction of the vehicle 2; the vertical direction Z is the up-down direction of the vehicle, or the vertical direction; and the horizontal direction Y, perpendicular to the lateral direction of the vehicle 2, is the front-rear direction of the vehicle 2 or the direction of travel of the vehicle. 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 vehicle) 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 various parts of the vehicle 2. 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 and other information from the navigation device 6 (car navigation system), external devices 400, terminal devices (e.g., mobile terminals) 410, 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. 【0014】 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. 【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 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. 【0016】 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. 【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 the vehicle 2 may also have the function of controlling the display device 1. 【0018】 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. 【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 reach 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 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. 【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 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. 【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 switches 911 are used to generate driver operation information for steering wheel switches, etc. 【0027】 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 information from external sources. 【0028】 Figure 3 is a block diagram of the display device 1. It is mainly used to control 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 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. 【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 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. 【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 of the vehicle 2, using a mechanism such as CAN or Automotive Ethernet (registered trademark). 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 4G or 5G mobile communication interface, or the like. 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. 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 the 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. As a result, the video display unit 200 creates and displays an image to be projected onto the display area 5 based on the video data. 【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】In addition, the display device 1 may protect the display panel 11 based on external light information from the illuminance sensor 905 or the like. That is, in order to prevent sunlight from hitting the display panel 11 and burning the display panel 11, the display device 1 may perform an operation of protecting 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 of burning of the display panel 11, 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. 【0045】 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, a configuration is adopted in which a nonvolatile memory 1011, a volatile memory 1012, a storage unit 1013, and a video processing unit 1016 are provided, respectively, but the above processing may be made to function by one memory. 【0046】 Next, the video display unit 200 will be specifically described. The video display unit (video display unit) 200 projects video light of a video formed on the display panel 11 using light emitted from the light source 20 (in other words, light source light) based on video data. The video display unit 200 may 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 panel LCD (Liquid Crystal Display) having a video display element. 【0047】 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, and generates predetermined light source light 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 have a configuration in which a plurality of light sources are arranged. A light source unit (backlight unit) hereinafter described may be configured using the light source 20 or the like. 【0048】The display panel 11 generates and emits video light obtained by modulating video based on the light from the light source. That is, the display panel 11 forms and displays video on the display screen based on video data, and generates and emits video light corresponding to the video based on the light from the light source 20. In this embodiment, the video data 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 (or projection light). 【0049】 Further, the display panel 11 may be a screen plate having a diffusing function, not limited to a liquid crystal panel. As means for projecting video onto a screen plate having a diffusing function, means for projecting an image of a DMD (Digital Micromirror Device) or a liquid crystal panel in combination with a projection lens, or means using a Micro Electro Mechanical Systems (MEMS) may be used. 【0050】 FIGS. 4 and 5 are diagrams showing a configuration example in which the display device 1 is mounted on the vehicle 2. FIG. 4 shows an example in which the display device 1 is mounted on a passenger car. The passenger car is a sports car, sedan, SUV (Sport Utility Vehicle), minivan, etc. in which the angle of the windshield or front glass 3 is 20° to 45° with respect to the Y-axis (the front-rear direction or traveling direction of the vehicle 2). FIG. 5 shows an example in which the display device 1 is mounted on some passenger cars and commercial vehicles. In other words, the windshield or front glass 3 in FIG. 5 is in a raised state. Specifically, the front glass 3 has an angle of 45° to 90° with respect to the Y-axis (the front-rear direction or traveling direction of the vehicle 2), and is a light super-high wagon, truck, or bus. As shown in FIGS. 4 and 5, the display device 1 is disposed on the dashboard 7 of the vehicle 2. The display device 1 may be mounted so as to be embedded in the dashboard 7. The dashboard 7 also includes an instrument panel including a meter cluster, for example, 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】 (First Embodiment) A first embodiment of a display device, which is one embodiment of the present invention, will be described. As mentioned above, the display device according to the first embodiment is a device that is placed on the dashboard of a vehicle and emits image light onto the windshield to form a virtual image. The display device according to the first embodiment can release the heat generated inside the housing to the outside while suppressing the intrusion of dust and the like into the housing 30. Furthermore, the display device according to the first embodiment can suppress light leakage from the optical system inside the housing. 【0058】 Figure 7 shows an example of the configuration of the display device 1 according to the first embodiment. As shown in Figure 7, the display device 1 according to the first embodiment includes a housing 30. The housing 30 has, for example, a roughly rectangular parallelepiped shape. The housing 30 has a bottom plate portion 31, a side wall portion 32, and an upper plate portion 33. The side wall portion 32 is connected to the bottom plate portion 31, and the upper plate portion 33 is connected to the side wall portion 32. The housing 30 houses a light source 20 and a first heat dissipation unit 48. In this embodiment, in the direction of travel of the vehicle (front-rear direction) and the vertical direction (up and down direction), the light source 20 and the first heat dissipation unit 48 connected to the light source 20 are arranged on the windshield side and upper part inside the housing 30. That is, the light source 20 and the first heat dissipation unit 48 are arranged with respect to the display panel 11, which will be described later, on the side closer to the direction of emission of the image light 60 from the normal N of the light emission surface of the display panel 11. Furthermore, the display panel 11 may be installed on the upper side of the housing 30 in the vertical direction of the vehicle. 【0059】The light-emitting surface of the light source 20 is oriented approximately downward or downward (approximately downward or downward in the Z direction) in the vertical direction of the vehicle, that is, toward the bottom plate portion 31. Below the light source 20, a reflective mirror 21 is positioned, which is curved inward so that its lower side is convex. A light-reflecting portion 23a of the light guide portion 23 is positioned toward the driver side relative to the reflective mirror 21. An opening for the emission of image light 60 is formed in the upper part of the housing 30 in the vertical direction, i.e., the top plate portion 33. That is, a display panel 11 is installed on the top plate portion 33 of the housing 30 so as to correspond to the opening, for example, by fitting together. The light emitted from the light source 20 is reflected by the reflective mirror 21, further reflected by the light-reflecting portion 23a, and passes through the display panel 11. The image light 60, which is the light that has passed through the display panel 11, can be emitted upward and tilted toward the windshield side. The image light 60 emitted from the display panel 11 is projected onto the windshield 3, which acts as a projection member, and the image light 60 reflected by the windshield 3 is made visible to the viewer as a virtual image. In this embodiment, the projection member has been described using a windshield 3, but the projection member is not limited to a windshield 3. The projection member may be a combiner, or a windshield or combiner with a film attached to its surface. The light source 20, the reflective mirror 21, and the light reflecting part 23a constitute the light source device. 【0060】 The first heat dissipation section 48 includes a fin section 48f on the windshield 3 side. The fin section 48f is shaped like a fin so that one or more grooves are formed along the vertical direction, i.e., the Z direction. The bottom plate section 31 has an opening 42 that functions as an air intake, located below the light source 20 and the first heat dissipation section 48. The top plate section 33 has an opening 41 that functions as an exhaust port, located above the light source 20 and the first heat dissipation section 48. Above the exhaust port opening 41, a louver 38 is provided to prevent dust and dirt from falling by their own weight and entering the inside of the housing 30 through the exhaust port. 【0061】When the light source 20 is driven and emits light, heat is released from the light source 20. The heat released from the light source 20 is transferred to the first heat dissipation section 48, where heat exchange takes place between the fin section 48f of the first heat dissipation section 48 and the air in contact with the fin section 48f. The air that has absorbed the heat creates an upward airflow AF. That is, the air enters the interior of the housing 30 through the opening 42, which is the intake port, passes through the grooves of the fin section 48f of the first heat dissipation section 48, exchanges heat with the first heat dissipation section 48 to cool it, and the air that has absorbed the heat is discharged to the outside of the housing 30 through the opening 41, which is the exhaust port. In other words, it can be said that in the housing 30, an exhaust port is formed on the downstream side of the airflow that exchanges heat with the first heat dissipation section 48, and an intake port is formed on the upstream side of the airflow. 【0062】 Furthermore, in order to expel the heat generated from the light source 20 to the outside of the housing 30, it is conceivable to attach a fan to the housing 30 and rotate the fan to forcibly generate airflow and efficiently cool the first heat dissipation unit 48. However, in this case, the airflow will be faster, increasing the amount of dust and dirt entering through the air intake, and increasing the risk of the optical system being contaminated by that dust and dirt. Even if filters are attached to the air intake and exhaust ports, fine dust and dirt will pass through the filters and enter the inside of the housing 30. Also, rotating the fan generates operating noise and wind noise. For this reason, in a display device 1 installed in a vehicle where a certain degree of quietness is maintained, it is more suitable not to attach a fan to the housing 30 and to expel the heat inside the housing 30 using the rising airflow. 【0063】Here, the direction in which the air flows through the grooves of the fin portion 48f of the first heat dissipation portion 48, that is, the direction of the airflow, is defined as the airflow direction F. The area of ​​the opening region of the opening 41, which is the exhaust port, is defined as the exhaust port area S1. Specifically, the area of ​​the region obtained by projecting the opening region of the opening 41, which is the exhaust port, onto a plane perpendicular to the airflow direction F1 at the exhaust port (i.e., in this case, the vertical direction, the Z direction) is defined as the exhaust port projected area S1p. Furthermore, the area of ​​the opening region of the opening 42, which is the intake port, is defined as the intake port area S2. Specifically, the area of ​​the region obtained by projecting the opening region of the opening 42, which is the intake port, onto a plane perpendicular to the airflow direction F2 at the intake port (i.e., in this case, the vertical direction, the Z direction) is defined as the intake port projected area S2p. At this time, the opening region of the exhaust port is set to be smaller than the opening region of the intake port. Specifically, the intake port projected area S2p is designed to be larger than the exhaust port projected area S1p. As a result, based on fluid dynamics, the airflow velocity near the intake port is slower than the airflow velocity near the exhaust port. Consequently, the amount of dust and dirt entering the interior of the housing 30 from the outside through the intake port can be reduced. 【0064】 Furthermore, a partition (dividing member) 50 is installed between the bottom plate portion 31 of the housing 30 and the reflective mirror 21 to block the space between them. The partition 50 is positioned, for example, closer to the air intake, as shown in Figure 7. The partition 50 prevents dust and dirt entering the housing 30 from entering the space where the optical system, such as the reflective mirror 21 or the light-reflecting portion 23a, is located. This reduces the adverse effects that dust and other debris have on the optical system, such as the reflective mirror 21 and the light-reflecting portion 23a. 【0065】 Preferably, the partition 50 is made of a material that does not transmit light. By making the partition 50 non-transmitting, it is possible to suppress the leakage light LL that leaks from the gap between the reflective mirror 21 and the light reflecting part 23a from being reflected inside the housing 30 and emitted to the outside. As a result, the viewer who views the virtual image displayed by the display device 1 can view the virtual image in a suitable environment free from leakage light LL. 【0066】Furthermore, it is preferable that the partition portion 50 is fixed to the bottom plate portion 31 and does not come into contact with the reflective mirror 21. The reflective mirror 21 is molded with high precision so that light incident on its reflective surface from the light source 20 is reflected toward the light reflecting portion 23a of the light guide portion 23. If the partition portion 50 comes into contact with the reflective mirror 21, the shape of the reflective mirror 21 will be distorted, and the light will not be reflected toward the light reflecting portion 23a of the light guide portion 23, which may cause distortion in the image light 60. For this reason, it is appropriate that the partition portion 50 does not come into contact with the reflective mirror 21 so as not to cause distortion in the shape of the reflective mirror 21. 【0067】 <Modification of the First Embodiment> Now, a modification of the first embodiment will be described. In the modification of the first embodiment, the arrangement of the partition section is changed. 【0068】 Figure 8 shows an example of the configuration of the display device 1 according to a modification of the first embodiment. As shown in Figure 8, in the modification of the first embodiment, the partition portion 50 is positioned closer to the driver side, i.e., the negative side in the Y direction. The partition portion 50 is positioned, for example, near the tip of the reflective mirror 21 on the driver side, i.e., the negative side in the Y direction. In this case, the gap area between the bottom plate portion 31 of the housing 30 and the reflective mirror 21 that is not filled by the partition portion 50 can be made smaller. As a result, the emission of leaked light LL that leaks from the gap between the reflective mirror 21 and the light reflecting portion 23a to the outside can be further suppressed. 【0069】 (Second Embodiment) Next, a second embodiment of the present invention will be described. In the second embodiment, the differences from the first embodiment will be explained, and the same configurations as in these embodiments will not be repeated. 【0070】Figure 9 shows an example of the configuration of the display device 1 according to the second embodiment. The display device 1 according to the second embodiment is assumed to be installed at an angle such that the windshield side of the housing 30 is located lower than the driver side of the housing 30. Such a display device 1 is used by being placed on the upper surface of a forward-tilted dashboard 7, for example, when the windshield side is facing forward. A forward-tilted dashboard 7 is commonly found in relatively large commercial vehicles such as trucks and buses. On the other hand, the same applies when the dashboard is not tilted forward, but the display device 1 is positioned at an angle. 【0071】 In the second embodiment, there are two openings that function as air intakes. To prevent the air intake projected area S2p from decreasing even when the housing 30 or the display device 1 is tilted forward, an opening 43 that functions as an air intake is also provided in the side wall portion 32w of the housing 30 on the windshield side, near the bottom plate portion 31. Here, the area of ​​the opening region of the opening 43 provided in the side wall portion 32w is defined as S3, and specifically, the area of ​​the region obtained by projecting the opening region of the opening 43 provided in the side wall portion 32w onto a plane perpendicular to the airflow direction F3 (i.e., the vertical Z direction) in the opening 43 is defined as the air intake projected area S3p. In the second embodiment as well, the opening region of the air intake is designed to be larger than the opening region of the exhaust port. In this case, the air intake opening region should be considered to include the concept of an overall air intake opening region that includes the opening regions of multiple air intakes. Specifically, the overall intake port projection area S2p + S2p is designed to be larger than the exhaust port projection area S1p. The other configurations are the same as in the first embodiment. As a result, even if the housing 30 or the display device 1 is tilted forward, the intake port projection area S3p can be sufficiently secured by providing an opening 43 in the side wall 32w that functions as an intake port. Consequently, the flow velocity of the airflow AF is slower near the intake port than near the exhaust port, which reduces the amount of dust and dirt that enters the housing 30 from the outside through the intake port. 【0072】(Third Embodiment) Next, the third embodiment will be described. In the third embodiment, the differences from the first or second embodiment will be explained, and the same configurations as in those embodiments will not be repeated. 【0073】 Figure 10 shows an example of the configuration of the display device 1 according to the third embodiment. As shown in Figure 10, in the display device 1 according to the third embodiment, the light source 20 and the first heat dissipation unit 48 are arranged closer to the driver side inside the housing 30. Furthermore, the display device 1 according to the third embodiment is assumed to be installed at an angle such that the windshield side of the housing 30 is located lower than the driver side of the housing 30. In this case, the air intake and exhaust ports are also provided closer to the driver side. That is, similar to the first embodiment, an opening 42 that functions as an air intake is formed in the portion of the bottom plate 31 located below the light source 20 and the first heat dissipation unit 48. The first heat dissipation unit 48 includes a fin portion 48f formed on the driver side. Furthermore, an opening 41 that functions as an exhaust port is formed in the portion of the top plate 33 located above the light source 20 and the first heat dissipation unit 48. 【0074】In the third embodiment, there are two openings that function as exhaust ports. In addition to the opening 41 formed above the housing 30, an opening 44 that functions as an exhaust port is also formed in the driver-side side wall portion 32d of the housing 30, in the portion close to the first heat dissipation portion 48. Furthermore, a louver 39 is provided above the opening 44 to prevent dust and dirt from falling by their own weight and entering the interior of the housing 30. Here, the area of ​​the opening region of the opening 44 that functions as an exhaust port is defined as S4, and specifically, the area of ​​the region obtained by projecting the opening region of the opening 44 onto a plane perpendicular to the airflow direction F4 in the opening 44 (i.e., the vertical direction, the Z direction) is defined as the exhaust port projected area S4p. In the third embodiment as well, the opening region of the intake port is designed to be larger than the opening region of the exhaust port. In this case, the opening region of the exhaust port should be considered to include the concept of the overall exhaust port opening region, which includes the opening regions of multiple exhaust ports. Alternatively, the intake port projected area S2p is designed to be larger than the overall exhaust port projected area S1p + S4p. As a result, as mentioned above, the airflow velocity AF is slower near the intake port than near the exhaust port, which reduces the amount of dust and dirt entering the housing 30 from outside through the intake port. 【0075】 (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described. In the fourth embodiment, the differences from the first embodiment will be explained, and the same configurations as in these embodiments will not be repeated. 【0076】Figure 11 shows an example of the configuration of the display device 1 according to the fourth embodiment. The display device 1 according to the fourth embodiment differs from the first embodiment in the shape of the first heat dissipation section 48 and the arrangement of the exhaust port. Specifically, the fin mounting surface 48r, which is the mounting surface at the base of the fin section 48f in the first heat dissipation section 48, is formed to be parallel to a surface that is rotated by an angle θ toward the windshield side with respect to the X direction of the XZ plane and inclined. The angle θ is, for example, an angle within the range of 30 to 60 degrees. In other words, the heat dissipation section 48 has a structure that changes the direction of the airflow from an upward direction in the vertical direction to a direction toward the side wall section 32w. The opening 45, which functions as an exhaust port, is formed in the part of the side wall section 32w on the windshield side of the housing 30 that is close to the first heat dissipation section 48. The opening 42, which serves as an air intake, is formed in the part of the bottom plate section 31 of the housing 30 that is located below the first heat dissipation section 48, similar to the first embodiment. 【0077】 In this case, the airflow direction F2 at the intake port, that is, the airflow direction F2 of the air drawn from outside the housing 30 through the intake port (opening 42) into the housing 30, is in the Z direction. The area of ​​the opening region of the intake port is S2, and the area obtained by projecting this opening region onto a plane perpendicular to the airflow direction F2 is the intake port projected area S2p (= S2). The airflow direction F5 at the exhaust port, that is, the airflow direction F5 of the air discharged from inside the housing 30 through the exhaust port (opening 45) to the outside of the housing 30, is in a direction parallel to the fin mounting surface 48r in the YZ plane. Here, the area of ​​the opening region of the exhaust port is defined as S5, and the area obtained by projecting this opening region onto a plane perpendicular to the airflow direction F5 is defined as the exhaust port projected area S5p. At this time, the intake port projected area S2p (S2) is designed to be larger than the exhaust port projected area S5p. The other configurations are the same as in the first embodiment. As a result, the airflow velocity near the intake port is slower than the airflow velocity near the exhaust port, which reduces the amount of dust and dirt that enters the interior of the housing 30 through the intake port. 【0078】(Fifth Embodiment) Next, an example of the configuration of the display device 1 according to the fifth embodiment will be described. In the fifth embodiment, the differences from the first embodiment will be explained, and the same configurations as in these embodiments will not be repeated. 【0079】 The display device 1 according to the fifth embodiment temporarily stores heat when the display panel 11 is heated by sunlight pouring in from outside the vehicle 2 through the windshield 3, etc., to prevent malfunction of the device due to a rapid rise in temperature of the display panel 11, etc. 【0080】 Figure 12 is a side view showing an example configuration of the display device 1 according to the fifth embodiment. Figure 13 is a top view showing an example configuration of the display device 1 according to the fifth embodiment. Compared to the first embodiment, the display device 1 according to the fifth embodiment further includes a heat storage unit (heat storage member) 73, a heat conduction unit (heat conduction member) 72 connected to a display panel 11 that absorbs heat rays contained in sunlight SL and transmits heat to the heat storage unit 73, and a second heat dissipation unit 74 connected to the heat storage unit 73. Inside the housing 30, the heat storage unit 73 and the second heat dissipation unit 74 are arranged on the side opposite to the side where the light source 20 and the first heat dissipation unit 48 are located. That is, in this embodiment, the heat storage unit 73 and the second heat dissipation unit 74 are arranged on the driver side inside the housing 30. The second heat dissipation unit 74 includes a fin portion 74f on the driver side. In the driver-side side wall portion 32d of the housing 30, an opening 47 is formed in the portion adjacent to the fin portion 74f of the second heat dissipation portion 74, which functions as an air intake for the airflow that exchanges heat with the second heat dissipation portion 74. In addition, in the upper plate portion 33 of the housing 30, an opening 46 is formed in the portion adjacent to the fin portion 74f of the second heat dissipation portion 74, which functions as an exhaust port for the airflow that exchanges heat with the second heat dissipation portion 74. 【0081】A glass material (transparent member) 71 is placed above the display panel 11 (light-emitting surface). A heat-conducting section 72, which has thermal conductivity, is placed, for example, between the display panel 11 and the glass material 71. The glass material may be other transparent members, such as acrylic resin. If the heat-conducting section 72 is made of a light-transmitting material, it may be placed so as to cover the entire display area of ​​the display panel 11. A material that has both thermal conductivity and light transmittance is, for example, transparent ceramics. If the heat-conducting section 72 is made of a material that does not transmit light, it may be placed so as to cover the periphery of the display panel 11. Alternatively, it may be placed so as to surround the periphery of the display area (light-emitting area) of the display panel 11. A material that has both thermal conductivity and light transmittance is, for example, copper, aluminum, silicon, etc. 【0082】 The heat storage section 73 is composed of a heat storage material. The heat storage material is also called a low-temperature holding agent. Examples of heat storage materials include sensible heat storage materials, chemical heat storage materials, and latent heat storage materials. Latent heat storage materials include solid-liquid transition types that utilize a solid-liquid phase transition and solid-solid transition types that utilize a solid-solid phase transition. In this embodiment, a latent heat storage material is preferred as the heat storage material constituting the heat storage section 73. Latent heat storage materials have the characteristics of being easy to process, durable, easy to control the temperature, and having a relatively high heat storage density. Furthermore, among latent heat storage materials, the solid-solid transition type is more preferred than the solid-liquid transition type. This is because solid-solid transition type latent heat storage materials are difficult to handle because they need to be configured so that the liquid does not leak out when the heat storage material transitions to a liquid state. Examples of solid-solid transition type latent heat storage materials include vanadium-based materials. 【0083】Figure 14 shows the properties of a latent heat storage material. In the graph of Figure 14, the horizontal axis represents heat quantity and the vertical axis represents temperature. As shown in the graph of Figure 14, when the latent heat storage material is in the low-temperature phase, the temperature rises as the amount of heat supplied increases. After the temperature of the latent heat storage material reaches the phase transition temperature, if the amount of heat supplied increases, it maintains the phase transition state for a while and holds the phase transition temperature. Then, when the amount of heat supplied to the latent heat storage material increases further, it enters the high-temperature phase state and the temperature rises again. 【0084】 Figure 15 shows an example of the temperature trend of the display panel. In the graph of Figure 15, the horizontal axis represents time, and the vertical axis represents the display panel temperature. The display panel temperature is a typical temperature of the display panel 11, for example, the average temperature. The solid line shows the display panel temperature when the heat storage unit 73 is present, and the dashed line shows the display panel temperature when the heat storage unit 73 is absent. The failure threshold temperature, which is an estimate of the temperature at which the risk of the display device 1 failing due to heat becomes very high, is, for example, 95 degrees Celsius. 【0085】 The light source 20 is driven, and the light emitted from the light source 20 is used to project the image light formed on the display panel 11 onto the projection member. After a certain / predetermined time has elapsed, the display panel temperature reaches the saturation temperature and is maintained at that temperature. In this state, suppose sunlight SL is incident on the display panel 11. If there is a heat storage unit 73, the display panel 11 is heated while sunlight SL is incident, but the heat storage due to the phase transition (1) of the heat storage material constituting the heat storage unit 73 prevents a rapid rise in the display panel temperature, and the display panel temperature does not reach the failure indicator temperature, which in this case is 95 degrees. After that, when sunlight SL stops incident, the heat dissipation due to the phase transition (2) of the heat storage material causes the display panel temperature to gradually decrease and asymptotically approach the saturation temperature. If the time of sunlight incidence is within a certain period of time, the display panel temperature can withstand the failure indicator temperature of 95 degrees. 【0086】On the other hand, if there is no heat storage unit 73, the display panel 11 is heated while sunlight SL is incident, allowing the display panel temperature to rise sharply, and the display panel temperature will exceed the failure indicator temperature. After that, when sunlight SL stops incident, the display panel temperature gradually decreases and asymptotically approaches the saturation temperature. Even if the time of sunlight incidence is within a certain period, if there is no heat storage unit 73, the display panel temperature will temporarily exceed the failure indicator temperature of 95 degrees, thus increasing the risk of failure. 【0087】 (Sixth Embodiment) Next, an example of the configuration of the display device according to the sixth embodiment will be described. In the sixth embodiment, the differences from the fifth embodiment will be explained, and the same configurations as in these embodiments will not be repeated. 【0088】 The display device 1 according to the sixth embodiment is based on the display device according to the fifth embodiment, with improvements made to further enhance the thermal conductivity of the display panel. The configuration examples of the display device 1 according to the sixth embodiment can be divided into a first configuration example in which the thermal conduction part does not have light transmittance and a second configuration example in which the thermal conduction part has light transmittance. Here, first the configuration example of the display device according to the sixth embodiment will be described, and then the second configuration example of the display device according to the sixth embodiment will be described. 【0089】 <First Configuration Example of the Sixth Embodiment> Figure 16 is a top view showing a first configuration example of the display device 1 according to the sixth embodiment. Figure 17 is a cross-sectional view showing a first configuration example of the display device 1 according to the sixth embodiment. Figure 17 shows cross-sectional views of cross-section A and cross-section B shown in Figure 16. Cross-section A is a cross-section of the display area of ​​the display panel 11, and cross-section B is a cross-section of the area surrounding the display area. The positions of cross-sections A and B are the same in the second configuration example. 【0090】In the second configuration example of the sixth embodiment, the heat conduction section 72 does not have light transmittance and is difficult to transmit image light from the display panel 11 to, so it is installed around the display area 11r of the display panel 11. In addition, in order to assist in the conduction of heat generated by sunlight SL incident on the display panel 11 to the heat conduction section 72, one or more fine wirings (wirings) 75 are installed so as to cross the display area 11r of the display panel 11, as shown in Figure 16. Both ends of the fine wiring 75 are physically connected to the heat conduction section 72. The fine wiring 75 is made of wire material mainly composed of a material with relatively high thermal conductivity, such as copper, aluminum, or iron. The line width of the fine wiring 75 is assumed to be, for example, about 10 μm to 100 μm. The configuration and line width of the fine wiring 75 are the same in the second configuration example. 【0091】 The fine wiring 75 is positioned between the display panel 11 and the glass material 71 in the display area 11r of the display panel 11, as shown in Figure 17, and is fixed by the adhesive 76 bonding the display panel 11 and the glass material 71 together. Furthermore, around the periphery of the display area 11r of the display panel 11, the fine wiring 75 is positioned between the heat conduction part 72 located on the upper plate portion of the housing 30 and the glass material 71, and is fixed by the adhesive 76 bonding the heat conduction part 72 and the glass material 71 together. 【0092】 The heat generated by the sunlight SL entering the display panel 11 is transferred to the heat conduction section 72 via the fine wiring 75 and stored in the heat storage section 73. The heat stored in the heat storage section 73 is then released through the second heat dissipation section 74. 【0093】 <Second Configuration Example of the Sixth Embodiment> Figure 18 is a top view showing a second configuration example of the display device 1 according to the sixth embodiment. Figure 19 is a cross-sectional view showing a second configuration example of the display device 1 according to the sixth embodiment. Figure 19 shows cross-sectional views of cross-section A and cross-section B shown in Figure 18. 【0094】In the second configuration example of the sixth embodiment, the heat conduction section 72 is light-transmitting and can transmit video light from the display panel 11, and is therefore installed to cover the display area 11r of the display panel 11. In addition, to assist heat conduction in the heat conduction section 72, one or more fine wirings 75 are installed to cross the display area 11r of the display panel 11, as shown in Figure 16. 【0095】 The fine wiring 75 is positioned between the display panel 11 and the heat conduction part 72 located on the bottom surface of the glass material 71 in the display area 11r of the display panel 11, as shown in Figure 19, and is fixed by the heat conduction part 72 and the display panel 11 being bonded together by the adhesive 76. Furthermore, the fine wiring 75 is fixed around the display area 11r of the display panel 11 by being sandwiched between the upper plate portion (not shown) of the housing 30 and the heat conduction part 72 located on the bottom surface of the glass material 71. The fine wiring 75 may also be fixed by the adhesive 76 in the area surrounding the display area 11r. 【0096】 Figure 20 is an enlarged view of the fine wiring in the sixth embodiment. As shown in Figure 20, in the display panel 11, multiple pixels 11p are arranged in a two-dimensional matrix. Generally, one pixel 11p is composed of three regions: the R region (red region) Rr, the G region (green region) Rg, and the B region (blue region) Rb. In addition, in each pixel 11p, the R region Rr, the G region Rg, and the B region Rb are often arranged sequentially in this order along one direction. Here, we assume that the R region Rr, the G region Rg, and the B region Rb are arranged sequentially along the X direction. In this case, regions of the same color will be arranged in the Y direction, which is perpendicular to the X direction. If the fine wiring 75 is installed to extend in a direction parallel to the Y direction, the fine wiring 75 will cross regions of the same color. That is, the fine wiring 75 will pass over regions of a specific color and block a portion of the transmitted light of that color. This can lead to a decrease in the light intensity of a specific color, potentially causing color unevenness in the image displayed on the display panel 11. 【0097】Therefore, it is preferable to arrange the fine wiring 75 so that it extends in a direction different from the direction perpendicular to the direction in which the R region Rr, G region Rg, and B region Rb are aligned. By arranging the fine wiring 75 in this way, it is possible to prevent a decrease in the light intensity of a particular color and suppress color unevenness of the image displayed on the display panel 11. For example, the fine wiring 75 may be arranged so that it extends in a direction parallel to the direction in which the R region Rr, G region Rg, and B region Rb are aligned, as shown in Figure 20. 【0098】 As described above, each embodiment of the present invention provides the aforementioned effects, thereby offering more suitable display technologies, such as display devices, display systems, and display methods. 【0099】 (Regarding modifications, etc.) The present invention is not limited to the above embodiments, and various modifications are possible. For example, the above embodiments are described in detail to make the present invention easy to understand, and the present invention is not necessarily limited to embodiments having all the described configurations. Furthermore, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment. Furthermore, it is possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to delete a part of the configuration of each embodiment, or to add or replace other configurations. 【0100】 More specifically, for example, the vehicle on which the display device 1 is installed is not limited to automobiles, but may also be other vehicles such as trams, monorails, railway trains, ships, or aircraft. 【0101】 Furthermore, the vehicle is not limited to those driven by a driver; it may also be a type that operates autonomously. 【0102】Furthermore, the display device 1 is not limited to a virtual image display device, but may be a type of display device that displays information on a liquid crystal panel or an organic EL panel, allowing the viewer to directly see it. Also, the display device 1 is not limited to a type in which a part of its main body is installed on the dashboard of a vehicle or on the interior of a vehicle, but may be a type that is built into the interior of a vehicle. The display device 1 may display information in a manner that can be seen by passengers of a vehicle. 【0103】 Furthermore, the number of openings that function as exhaust ports and the number of openings that function as intake ports may each be multiple. The shape of the openings that function as exhaust ports or intake ports may be a polygon including a rectangle, a circle including an ellipse, or any other shape. The position of the openings that function as exhaust ports is not limited to the above examples, and they may be provided at any position as long as the exhaust port is located downstream of the airflow and the intake port is located upstream of the airflow. 【0104】 Furthermore, the display methods in the display devices according to each of the above embodiments, and the display methods using said display devices, are embodiments of one embodiment of the present invention. Also, the vehicle on which said display device is installed is also an embodiment of the present invention. 【0105】 Furthermore, the technology described in the above embodiment makes it possible to prevent traffic accidents by providing a display device that can display a good virtual image, reduce the driver's eye movement, and contribute to supporting safe driving. This contributes to "Goal 3: Good Health and Well-being" of the United Nations' Sustainable Development Goals (SDGs). 【0106】1 Display device (virtual image display device) 2 Vehicle 3 Windshield 4 Vehicle information 5 Display area 10 Virtual image 11 Display panel 12 Light source unit 20 Light source 21 Reflective mirror 22 Polarization conversion element 23 Light guide unit 23a Light reflecting unit 24 Diffuser plate 30 Housing 31 Bottom plate unit 32 Side wall unit 33 Top plate unit 38 Louver 41 Opening (exhaust port) 42 Opening (intake port) 48 First heat dissipation unit 48f Fin unit 50 Partition unit (dividing member) 60 Image light 71 Glass material 72 Heat conduction unit 73 Heat storage unit 74 Second heat dissipation unit 75 Fine wiring 76 Adhesive 100 Controller 400 External equipment 410 Terminal device 500 Network 600 Relay station 700 Server AF Airflow F1 Airflow direction at exhaust port F2 Airflow direction at intake port LL Leakage light S1p Projected area of ​​exhaust port S2p Projected area of ​​intake port

Claims

1. A display device comprising: a display panel capable of emitting image light; a light source device including a light source and emitting light emitted from the light source to the display panel; a first heat dissipation unit connected to the light source; and a housing in which the light source device and the first heat dissipation unit are disposed inside, and the display panel is installed on the upper side, wherein in the housing, an exhaust port is formed downstream of the airflow that exchanges heat with the first heat dissipation unit, and an intake port is formed upstream of the airflow, and the opening area of ​​the exhaust port is smaller than the opening area of ​​the intake port.

2. A display device according to claim 1, wherein the exhaust port projected area, which is the area of ​​the region obtained by projecting the opening region of the exhaust port onto a plane perpendicular to the direction of the airflow at the exhaust port, is smaller than the intake port projected area, which is the area of ​​the region obtained by projecting the opening region of the intake port onto a plane perpendicular to the direction of the airflow at the intake port.

3. A display device according to claim 1, wherein the first heat dissipation unit is positioned with respect to the display panel on a side closer to the direction of emission of the image light from the normal to the light emission surface of the display panel.

4. A display device according to claim 1, wherein the housing has a bottom plate portion, a side wall portion, and an upper plate portion, and the display device comprises a reflective mirror that reflects light emitted by the light source, and a partition member disposed between the reflective mirror and the bottom plate portion of the housing.

5. A display device according to claim 1, wherein the housing has a bottom plate portion, a side wall portion, and an upper plate portion, the exhaust port includes an opening formed in the upper plate portion of the housing adjacent to the first heat dissipation portion and an opening formed in the side wall portion of the housing adjacent to the first heat dissipation portion, and the intake port includes an opening formed in the bottom plate portion of the housing below the first heat dissipation portion.

6. A display device according to claim 1, wherein the housing has a bottom plate portion, a side wall portion, and an upper plate portion, the exhaust port includes an opening formed in the upper plate portion of the housing adjacent to the first heat dissipation portion, and the intake port includes an opening formed in the bottom plate portion of the housing below the first heat dissipation portion.

7. A display device according to claim 1, wherein the housing has a bottom plate portion, a side wall portion, and an upper plate portion, the first heat dissipation portion has a structure that changes the direction of the airflow from a vertically upward direction to a direction toward the side wall portion, the exhaust port includes an opening formed in the side wall portion of the housing adjacent to the first heat dissipation portion, and the intake port includes an opening formed in the bottom plate portion of the housing below the first heat dissipation portion.

8. A display device according to claim 1, comprising: a heat conductive member connected to the display panel; a heat storage member connected to the heat conductive member; and a second heat dissipation unit connected to the heat storage member.

9. A display device according to claim 8, wherein the heat storage member is made of a latent heat storage material.

10. A display device according to claim 9, wherein the latent heat storage material is a solid-solid transition type.

11. A display device according to claim 8, wherein the heat conductive member is not light-transmitting and is arranged in a region surrounding the display area of ​​the display panel.

12. A display device according to claim 8, wherein the heat conductive member is light-transmitting and is arranged to cover the display area of ​​the display panel.

13. A display device according to claim 11, comprising one or more wires connected to the heat conductive member, arranged to cross the display area of ​​the display panel, and having thermal conductivity.

14. A display device according to claim 12, comprising one or more wires connected to the heat conductive member, arranged to cross the display area of ​​the display panel, and having thermal conductivity.

15. A display device according to claim 13, wherein the wiring is arranged to extend along a direction different from the direction in which the R, G, and B regions constituting the pixels in the display panel are sequentially arranged.

16. A display device according to claim 15, wherein the wiring is arranged to extend along a direction parallel to the direction in which the regions R, G, and B are aligned.

17. A display device according to claim 1, wherein the image light is reflected by a projection member, thereby causing the image generated by the display panel to be perceived by the viewer as a virtual image.

Images