Light emitting device, head-up display, vehicle lamp, and projector

Abstract

The present invention provides a light emitting device capable of preventing heat damage caused by external light without reducing the light emitting function. The light emitting device (20) comprises: a light source (24); an optical component (27) which amplifies the light emitted from the light source (24) by transmitting or reflecting the light and irradiates the light to the outside; and an optical isolator (70) which can transmit the light but prevent external light from the outside from entering the light source (24).

Description

Technical Field

[0001] The present disclosure relates to a light emitting device, a head-up display, a vehicle lamp, and a projector. Background Art

[0002] It is expected that there will be a mixture of vehicles traveling in an automatic driving mode and vehicles traveling in a manual driving mode on the road.

[0003] In the future autonomous driving society, visual communication between vehicles and people becomes increasingly important. For example, it is expected that visual communication between a vehicle and its passengers becomes increasingly important. In this regard, a head-up display (HUD) can be used to achieve visual communication between the vehicle and its passengers. The head-up display projects images and images onto the windshield or synthesizer, and the images are overlapped with the real space through the windshield or synthesizer so that the passengers can visually confirm them, thereby achieving the so-called AR (Augmented Reality).

[0004] As an example of a head-up display, in patent document 1, a display device is disclosed, which has an optical system for displaying a three-dimensional virtual image using a transparent display medium. The display device projects light into the driver's field of vision on a windshield or a synthesizer. Part of the projected light passes through the windshield or the synthesizer, and the other part is reflected by the windshield or the synthesizer. The reflected light goes to the driver's eyes. The driver perceives the reflected light entering the eyes as a virtual image: the virtual image is based on an actual object that is visible across the windshield and the synthesizer, and appears to be an image of an object that exists on the opposite side (outside the motor vehicle) across the windshield and the synthesizer.

[0005] In addition, if external light such as sunlight enters the interior of the head-up display, the external light is concentrated by the display and causes a local temperature rise, which may cause disorder in the image display and thermal damage to the display. In order to prevent the above-mentioned problems, there are known structures for improving the heat dissipation of the display and for providing a plate reflecting infrared rays between the display and the reflecting part (see Patent Document 2). However, in Patent Document 2, it is necessary to additionally provide a component for suppressing the temperature rise of the display, which will lead to high costs.

[0006] The display device has a reflecting part that reflects the image of light formed on the screen toward a windshield or a combiner. When a concave mirror is used as the reflecting part, a high-definition concave mirror is required, which leads to high cost of the display device.

[0007] Furthermore, in the conventional head-up display, there is room for improvement in the structure for expanding the display range of the virtual image (image).

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Publication No. 2018-45103

[0011] Patent Document 2: Japanese Patent Application Publication No. 2005-313733 Summary of the invention

[0012] Problems to be solved by the invention

[0013] One of the objects of the present disclosure is to provide a light emitting device, a head-up display, a vehicle lamp, and a projector that can prevent the occurrence of heat damage caused by external light without reducing the light emitting function.

[0014] One of the objects of the present disclosure is to provide a head-up display capable of realizing a reflection portion at low cost without significantly reducing the quality of a virtual image.

[0015] One of the objects of the present disclosure is to provide a head-up display capable of realizing a reflecting portion at low cost.

[0016] One of the objects of the present disclosure is to provide a head-up display capable of expanding the display range of an image at low cost.

[0017] Means used to solve problems

[0018] A light emitting device according to one aspect of the present disclosure includes:

[0019] light source;

[0020] an optical member that transmits or reflects the light emitted from the light source to expand the light and irradiate the light to the outside;

[0021] The optical isolator can transmit the light but prevent the external light from the outside from entering the light source.

[0022] According to the above configuration, it is possible to provide a light emitting device that can prevent the occurrence of thermal damage due to external light entering the light source without reducing the light emitting function.

[0023] One aspect of the present disclosure relates to a head-up display,

[0024] The head-up display is provided in a vehicle and comprises the light emitting device described above,

[0025] The light emitting device is configured to display a predetermined image toward a passenger of the vehicle,

[0026] The optical member transmits or reflects the light emitted from the light source so that the light is irradiated toward a windshield or a combiner.

[0027] The optical isolator is disposed at a position where the light passes between the light source and the optical member or between the optical member and the windshield or the combiner.

[0028] According to the above configuration, it is possible to provide a head-up display capable of preventing thermal damage caused by external light entering the light source without reducing the light emitting function.

[0029] One aspect of the present disclosure relates to a vehicle lamp,

[0030] The vehicle lamp is installed in a vehicle and comprises the light emitting device described above.

[0031] The light emitting device is configured to emit light toward the surroundings of the vehicle.

[0032] The optical isolator is disposed at a position where the light passes between the light source and the optical member or between the optical member and an outer lens of the vehicle lamp.

[0033] According to the above configuration, it is possible to provide a vehicle lamp that can prevent thermal damage caused by external light entering the light source without reducing the light emitting function.

[0034] One aspect of the present disclosure relates to a projector,

[0035] A projector having the light emitting device described above,

[0036] The light emitting device is configured to display a predetermined image on an object outside the projector.

[0037] The optical isolator is disposed at a position where the light passes between the light source and the optical member or between the optical member and the object.

[0038] According to the above configuration, it is possible to provide a projector that can prevent the occurrence of thermal damage due to external light entering the light source without reducing the light emitting function.

[0039] One aspect of the present disclosure relates to a head-up display,

[0040] The head-up display is provided in a vehicle and is configured to display a predetermined image toward a passenger of the vehicle.

[0041] The head-up display comprises:

[0042] an image generating unit configured to emit a first light for generating a first image among the predetermined images and a second light for generating a second image among the predetermined images; and

[0043] a reflecting unit configured to reflect the first light and the second light emitted from the image generating unit so as to irradiate the first light and the second light toward a windshield or a combiner,

[0044] The reflecting portion has a reflecting surface including a first reflecting region for reflecting the first light and a second reflecting region for reflecting the second light.

[0045] The first reflective region has a first surface roughness, and the second reflective region has a second surface roughness that is rougher than the first surface roughness.

[0046] According to the above configuration, the second reflection area has a rougher surface than the first reflection area. Therefore, the second reflection area can be formed at a low cost compared with the first reflection area. On the other hand, the first reflection area has a smoother surface than the second reflection area. Therefore, the first image can be recognized as a high-quality virtual image. Therefore, the reflection portion can be realized at a low cost without significantly reducing the quality of the virtual image.

[0047] One aspect of the present disclosure relates to a head-up display,

[0048] The head-up display is provided in a vehicle and is configured to display a predetermined image toward a passenger of the vehicle.

[0049] The head-up display comprises:

[0050] an image generating unit configured to emit a first light for generating a first image among the predetermined images and a second light for generating a second image among the predetermined images; and

[0051] a reflecting unit configured to reflect the first light and the second light emitted from the image generating unit so as to irradiate the first light and the second light toward a windshield or a combiner,

[0052] The reflecting unit includes a concave mirror that reflects the first light and a plane mirror that reflects the second light.

[0053] According to the above configuration, since the reflecting portion is constituted by the concave mirror and the plane mirror, the reflecting portion can be realized at low cost.

[0054] One aspect of the present disclosure relates to a head-up display,

[0055] A head-up display is provided in a vehicle and is configured to display a predetermined image to a passenger of the vehicle.

[0056] The head-up display comprises:

[0057] an image generating unit that emits light for generating the predetermined image; and

[0058] a reflecting unit that reflects the light emitted by the image generating unit so as to irradiate the light toward a windshield or a synthesizer,

[0059] On the light emitting surface of the image generating unit, an area capable of forming a rectangular maximum display range for displaying a first image as a part of the predetermined image is set as a first area, and an area other than the first area is set as a second area,

[0060] Outside the maximum display range in which the first image can be displayed by the light emitted from the first area, a second image different from the first image is displayed by the light emitted from the second area.

[0061] According to the above configuration, since the second image can be displayed outside the maximum display range of the rectangle in which the first image is displayed, the image display range can be expanded compared to the conventional technology.

[0062] Effects of the Invention

[0063] According to the present disclosure, it is possible to provide a light emitting device, a head-up display, a vehicle lamp, and a projector that can prevent the occurrence of heat damage caused by external light without reducing the light emitting function.

[0064] According to the present disclosure, it is possible to provide a head-up display capable of realizing a reflection portion at low cost without significantly reducing the quality of a virtual image.

[0065] According to the present disclosure, it is possible to provide a head-up display capable of realizing a reflecting portion at low cost.

[0066] According to the present disclosure, it is possible to provide a head-up display capable of expanding the display range of an image at low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 This is a block diagram of a vehicle system including a head-up display (HUD) as a light irradiation device according to the present embodiment.

[0068] Figure 2 : is a schematic diagram of the HUD involved in the first embodiment.

[0069] Figure 3 yes Figure 2 A cross-sectional view of an optical isolator included in a HUD.

[0070] Figure 4 It is used to illustrate Figure 3 Schematic diagram of the magnetic field of an optical isolator.

[0071] Figure 5 It is used to illustrate Figure 3 Schematic diagram of the functionality of an optical isolator.

[0072] Figure 6 It is used to illustrate Figure 3 Schematic diagram of the functionality of an optical isolator.

[0073] Figure 7 This is a diagram showing a state where external light enters a HUD that does not include an optical isolator.

[0074] Figure 8 It means that external light enters Figure 2 A diagram of the status of the HUD.

[0075] Fig. 9 It is a schematic diagram of a HUD according to a first modification.

[0076] Fig.10 It is a schematic diagram of a HUD according to a second modification.

[0077] Fig.11 It is a longitudinal sectional view of a vehicle lamp as a light irradiation device according to a second embodiment.

[0078] Fig.12 It is a schematic diagram of a HUD according to the third embodiment.

[0079] Fig.13A Yes Fig.12 Schematic diagram of the example of a concave mirror.

[0080] Fig. 13B Observed from the direction of the arrow along line IIIB-IIIB Fig.13A Cross-sectional view as seen through a concave mirror.

[0081] Fig. 13C Yes means Fig. 13B A partial enlarged view of area IIIC.

[0082] Fig.14 This is a schematic diagram illustrating an area illuminated by light emitted from the HUD on the windshield.

[0083] Fig.15A This is a schematic diagram illustrating a concave mirror according to a modification example.

[0084] Fig. 15B Observed from the direction of the arrow along the VB-VB line Fig.15A Cross-sectional view as seen through a concave mirror.

[0085] Fig.16A This is a schematic diagram illustrating a concave mirror according to the fourth embodiment.

[0086] Fig. 16B Observed from the direction of the arrow along the VIB-VIB line Fig.16A Cross-sectional view as seen through a concave mirror.

[0087] Fig.17 This is a schematic diagram illustrating an area illuminated by light emitted from the HUD on the windshield.

[0088] Fig.18 It is a schematic diagram of a HUD according to the fifth embodiment.

[0089] Fig.19 This is a schematic diagram illustrating an example of a reflection portion viewed from an image generation portion.

[0090] Fig. 20 This is a schematic diagram illustrating an area illuminated by light emitted from the HUD on the windshield.

[0091] Fig.21 It is a schematic diagram of a HUD according to the sixth embodiment.

[0092] Fig. 22 It is a schematic diagram of a HUD according to the seventh embodiment.

[0093] Fig.23 This is a schematic diagram illustrating an example of a reflection portion viewed from an image generation portion.

[0094] Fig.24 This is a schematic diagram illustrating an area illuminated by light emitted from the HUD on the windshield.

[0095] Fig.25 It is a schematic diagram of a HUD according to the eighth embodiment.

[0096] Fig.26 It is a schematic diagram showing the structure of a HUD according to a ninth embodiment.

[0097] Fig.27A FIG. 1 is a diagram showing an example of an emission surface image generated by an image generating unit of the HUD according to the comparative example.

[0098] Fig.27B Yes Fig.27A The image of the exit surface shown is displayed as a virtual image.

[0099] Fig.28 FIG. 1 is a diagram showing an example of an emission surface image generated by an image generating unit of the HUD according to the ninth embodiment.

[0100] Fig.29 Yes Fig.28 The image of the exit surface shown is displayed as a virtual image.

[0101] Fig.30 : is a schematic diagram showing a HUD according to a modification example. DETAILED DESCRIPTION

[0102] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. The dimensions of the components shown in the drawings are for convenience of description and may be different from the actual dimensions of the components.

[0103] In the description of the present embodiment, for the convenience of description, "left-right direction", "up-down direction" and "front-back direction" are sometimes appropriately mentioned. These directions are for Figure 2 The relative directions set by the HUD (Head-Up Display) 20 shown in FIG. Here, the "left-right direction" is a direction including the "left" and the "right". The "up-down direction" is a direction including the "up" and the "down". The "front-back direction" is a direction including the "front" and the "back". The left-right direction is Figure 2 Although not shown, it is a direction perpendicular to the up-down direction and the front-back direction.

[0104] First, refer to Figure 1 , a vehicle system 2 including the HUD 20 according to the present embodiment will be described below. Figure 1 2 is a block diagram of a vehicle system 2. A vehicle 1 equipped with the vehicle system 2 is a vehicle (automobile) that can travel in an automatic driving mode.

[0105] like Figure 1 As shown, the vehicle system 2 includes a vehicle control unit 3, a sensor 5, a camera 6, a radar 7, an HMI (Human Machine Interface) 8, a GPS (Global Positioning System) 9, a wireless communication unit 10, and a storage device 11. In addition, the vehicle system 2 includes a steering actuator 12, a steering device 13, a brake actuator 14, a brake device 15, an acceleration actuator 16, and an acceleration device 17. Furthermore, the vehicle system 2 includes a HUD 20.

[0106] The vehicle control unit 3 is configured to control the driving of the vehicle 1. The vehicle control unit 3 is composed of, for example, at least one electronic control unit (ECU). The electronic control unit includes a computer system (for example, SoC (System on a Chip)) having one or more processors and memories, and an electronic circuit composed of active elements such as transistors and passive elements such as resistors. The processor includes, for example, at least one of a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a GPU (Graphics Processing Unit), and a TPU (Tensor Processing Unit). The CPU can be composed of multiple CPUs. The GPU can be composed of multiple GPU cores. The memory includes ROM (Read Only Memory) and RAM (Random Access Memory). In the ROM, a vehicle control program can be stored. For example, the vehicle control program can include an artificial intelligence (AI) program for autonomous driving. The AI ​​program is a program (learning completion model) constructed by supervised or unsupervised machine learning (especially deep learning) using a multi-layer neural network. In RAM, vehicle control programs, vehicle control data and / or surrounding environment information representing the surrounding environment of vehicle 1 can be temporarily stored. The processor can be configured to load programs specified by various vehicle control programs stored in ROM onto RAM, and perform various processes by cooperating with RAM. In addition, the computer system can be composed of non-Neumann computers such as ASIC (Application Specific Integrated Circuit) and FPGA (Field-Programmable Gate Array). Furthermore, the computer system can also be composed of a combination of Neumann computers and non-Neumann computers.

[0107] The sensor 5 includes at least one of an acceleration sensor, a speed sensor, and a gyro sensor. The sensor 5 is configured to detect the driving state of the vehicle 1 and output the driving state information to the vehicle control unit 3. The sensor 5 may also include a seat sensor for detecting whether the driver is sitting in the driver's seat, a face orientation sensor for detecting the direction of the driver's face, an external weather sensor for detecting the external weather state, and a human sensor for detecting whether there is a person in the vehicle.

[0108] The camera 6 is a camera including an imaging element such as a CCD (Charge-Coupled Device) or a CMOS (Complementary MOS), etc. The camera 6 includes one or more external cameras 6A and an internal camera 6B.

[0109] The external camera 6A is configured to send the image data representing the surrounding environment of the vehicle 1 to the vehicle control unit 3 after acquiring the image data. The vehicle control unit 3 acquires the surrounding environment information based on the image data sent. Here, the surrounding environment information may also include information related to objects (pedestrians, other vehicles, signs, etc.) existing outside the vehicle 1. For example, the surrounding environment information may also include information related to the attributes of the objects existing outside the vehicle 1, and information related to the distance and position of the objects from the vehicle 1. The external camera 6A may be configured as a single-lens camera or a stereo camera.

[0110] The interior camera 6B is configured to be disposed inside the vehicle 1 and to acquire image data representing the passenger. The interior camera 6B is configured to capture image data representing the passenger from a viewpoint E (via a Figure 2 The interior camera 6B is provided, for example, near a rearview mirror in the vehicle cabin or inside a dashboard.

[0111] The radar 7 includes at least one of a millimeter wave radar, a microwave radar, and a laser radar (e.g., a LiDAR unit). For example, the LiDAR unit is configured to detect the surrounding environment of the vehicle 1. In particular, the LiDAR unit is configured to, upon acquiring 3D mapping data (point cloud data) representing the surrounding environment of the vehicle 1, send the 3D mapping data to the vehicle control unit 3. The vehicle control unit 3 determines the surrounding environment information based on the sent 3D mapping data.

[0112] The HMI 8 is composed of an input unit that receives input operations from the driver and an output unit that outputs driving information to the driver. The input unit includes a steering wheel, an accelerator pedal, a brake pedal, a driving mode switch that switches the driving mode of the vehicle 1, etc. The output unit is a display (excluding the HUD) that displays various driving information.

[0113] The GPS 9 is configured to acquire current position information of the vehicle 1 and output the acquired current position information to the vehicle control unit 3 .

[0114] The wireless communication unit 10 is configured to receive information related to other vehicles (e.g., driving information, etc.) existing around the vehicle 1 from other vehicles, and to send information related to the vehicle 1 (e.g., driving information, etc.) to other vehicles (vehicle-to-vehicle communication). In addition, the wireless communication unit 10 is configured to receive infrastructure information from infrastructure equipment such as signal lights and sign lights, and to send driving information of the vehicle 1 to the infrastructure equipment (road-to-vehicle communication). In addition, the wireless communication unit 10 is configured to receive information related to pedestrians from portable electronic devices (smartphones, tablets, wearable devices, etc.) carried by pedestrians, and to send the driving information of the vehicle 1 to the portable electronic device (pedestrian-to-vehicle communication). The vehicle 1 can communicate directly with other vehicles, infrastructure equipment or portable electronic devices in an ad-hoc mode, or can communicate via an access point. Furthermore, the vehicle 1 can communicate with other vehicles, infrastructure equipment or portable electronic devices via a communication network not shown in the figure. The communication network includes at least one of the Internet, a local area network (LAN), a wide area network (WAN) and a radio access network (RAN). The wireless communication standard is, for example, Wi-Fi (registered trademark), Bluetooth (registered trademark), ZigBee (registered trademark), LPWA, DSRC (registered trademark), or Li-Fi. In addition, the vehicle 1 can communicate with other vehicles, infrastructure equipment, or portable electronic devices using the fifth generation mobile communication system (5G).

[0115] The storage device 11 is an external storage device such as a hard disk drive (HDD) or an SSD (Solid State Drive). In the storage device 11, two-dimensional or three-dimensional map information and / or a vehicle control program may be stored. For example, three-dimensional map information may be composed of 3D mapping data (point cloud data). The storage device 11 is configured to output the map information and the vehicle control program to the vehicle control unit 3 in response to a request from the vehicle control unit 3. The map information and the vehicle control program may be updated via the wireless communication unit 10 and the communication network.

[0116] When the vehicle 1 is traveling in the automatic driving mode, the vehicle control unit 3 automatically generates at least one of a steering control signal, an acceleration control signal, and a braking control signal based on driving state information, surrounding environment information, current position information, map information, etc. The steering actuator 12 is configured to receive a steering control signal from the vehicle control unit 3, and control a steering device 13 based on the received steering control signal. The brake actuator 14 is configured to receive a brake control signal from the vehicle control unit 3, and control a brake device 15 based on the received brake control signal. The acceleration actuator 16 is configured to receive an acceleration control signal from the vehicle control unit 3, and control an acceleration device 17 based on the received acceleration control signal. In this way, the vehicle control unit 3 automatically controls the driving of the vehicle 1 based on the driving state information, surrounding environment information, current position information, map information, etc. That is, in the automatic driving mode, the driving of the vehicle 1 is automatically controlled by the vehicle system 2.

[0117] On the other hand, when the vehicle 1 is traveling in the manual driving mode, the vehicle control unit 3 generates a steering control signal, an acceleration control signal, and a braking control signal according to the driver's manual operation of the accelerator pedal, the brake pedal, and the steering wheel. Thus, in the manual driving mode, since the steering control signal, the acceleration control signal, and the braking control signal are generated by the driver's manual operation, the driving of the vehicle 1 is controlled by the driver.

[0118] As described above, the driving mode consists of an automatic driving mode and a manual driving mode. The automatic driving mode consists of, for example, a fully automatic driving mode, a highly driven driving assistance mode, and a driving assistance mode. In the fully automatic driving mode, the vehicle system 2 automatically performs all driving controls of steering control, braking control, and acceleration control, and the driver is not in a state where he can drive the vehicle 1. In the highly driven driving assistance mode, the vehicle system 2 automatically performs all driving controls of steering control, braking control, and acceleration control, and the driver does not drive the vehicle 1 although he is in a state where he can drive the vehicle 1. In the driving assistance mode, the vehicle system 2 automatically performs driving controls of a part of the steering control, braking control, and acceleration control, and the driver drives the vehicle 1 with the driving assistance of the vehicle system 2. On the other hand, in the manual driving mode, the vehicle system 2 does not automatically perform driving control, and the driver drives the vehicle 1 without the driving assistance of the vehicle system 2.

[0119] The HUD 20 is configured to display predetermined information (hereinafter referred to as HUD information) as an image toward the passenger of the vehicle 1 in a manner that the HUD information overlaps with the real space outside the vehicle 1 (particularly, the surrounding environment in front of the vehicle 1). The HUD information displayed by the HUD 20 is, for example, vehicle driving information related to the driving of the vehicle 1 and / or surrounding environment information related to the surrounding environment of the vehicle 1 (particularly, information related to objects existing outside the vehicle 1). The HUD 20 is an AR display that functions as a visual interface between the vehicle 1 and the passenger.

[0120] In the HUD 20, at least a part of the HUD 20 is located inside the vehicle 1. Specifically, the HUD 20 is provided at a predetermined position in the cabin of the vehicle 1. For example, the HUD 20 may be arranged in the instrument panel of the vehicle 1.

[0121] The HUD 20 includes an image generation unit (PGU: Picture Generation Unit) 24 and a control unit 25 .

[0122] The image generating unit 24 is configured to emit light for generating a predetermined image to be displayed to a passenger of the vehicle 1 .

[0123] The control unit 25 is configured to control the operation of each part of the HUD 20. The control unit 25 is connected to the vehicle control unit 3, and controls the operation of each part of the HUD 20 such as the image generation unit 24 based on the vehicle driving information, surrounding environment information, etc. sent from the vehicle control unit 3. It should be noted that in the present embodiment, the vehicle control unit 3 and the control unit 25 are configured to be independent (separately), but the vehicle control unit 3 and the control unit 25 may also be configured as one. For example, the vehicle control unit 3 and the control unit 25 may be configured by a single electronic control unit.

[0124] (First embodiment)

[0125] Figure 2 1 is a schematic diagram of the HUD 20 according to the first embodiment as viewed from the side of the vehicle 1. Figure 2 As shown, the HUD 20 includes a HUD main body 21 (an example of a light emitting device). The HUD main body 21 includes a housing 22 and an emission window 23. The emission window 23 is composed of a transparent plate that allows light to pass through. The HUD main body 21 includes an image generation unit (PGU: Picture Generation Unit) 24, a plane mirror 26 (an example of a reflection unit), a concave mirror 27 (an example of a reflection unit), an optical isolator 70, and a control substrate 29 inside the housing 22.

[0126] The image generating unit 24 is configured to emit light for generating a predetermined image to be displayed to the passengers of the vehicle 1. The image generating unit 24 includes a light source, an optical component, and a display device, and detailed illustration is omitted. The light source is, for example, a laser light source or an LED light source. The laser light source is, for example, an RGB laser light source configured to emit red laser, green laser, and blue laser, respectively. The optical component appropriately includes a prism, a lens, a diffuser, a magnifying glass, etc. The optical component transmits the light emitted from the light source and emits it toward the display device. The display device is a liquid crystal display, a DMD (Digital Mirror Device), etc. The drawing method of the image generating unit 24 can be a raster scanning method, a DLP (Digital Light Processing) method, or an LCOS (Liquid Crystal On Silicon) method. In the case of using the DLP method or the LCOS method, the light source can be an LED light source. It should be noted that in the case of using the liquid crystal display method, the light source can be a white LED light source.

[0127] The plane mirror 26 is arranged at a position where the light emitted from the image generating unit 24 can be reflected in the direction toward the concave mirror 27. It should be noted that, as an optical element replacing the plane mirror 26, for example, a lens can be used. When a lens is used, it is preferable to adjust the positional relationship between the image generating unit 24, the lens, and the concave mirror 27 so that the light emitted from the image generating unit 24 passes through the lens and goes to the concave mirror 27.

[0128] The concave mirror 27 is arranged on the optical path of the light emitted from the image generating unit 24 and reflected by the plane mirror 26. The concave mirror 27 is configured to reflect the light emitted from the image generating unit 24 toward the windshield 18 (for example, the front window of the vehicle 1). The concave mirror 27 has a reflecting surface that is curved into a concave shape in order to form a predetermined image, so that the image of the light emitted from the image generating unit 24 and formed is reflected at a predetermined magnification. That is, the concave mirror 27 enlarges the light emitted from the image generating unit 24 by reflecting the light and irradiates it to the outside of the HUD 20. The concave mirror 27 has a driving mechanism (not shown). The driving mechanism can rotate the direction of the concave mirror 27 based on a control signal sent from the control substrate 29.

[0129] The control substrate 29 constituting the control unit 25 is configured to control the operation of the image generating unit 24. The control substrate 29 is equipped with a processor such as a CPU (Central Processing Unit) and a memory, and the processor executes a computer program read from the memory to control the operation of the image generating unit 24. For example, the control substrate 29 generates a control signal for controlling the operation of the image generating unit 24 based on vehicle driving information, surrounding environment information, etc. sent from the vehicle control unit 3, and sends the generated control signal to the image generating unit 24. In addition, the control substrate 29 can control in a manner that changes the orientation of the concave mirror 27.

[0130] The optical isolator 70 is an optical filter disposed between the concave mirror 27 and the exit window 23. The optical isolator 70 is provided at a position where light emitted from the image generating unit 24, reflected by the plane mirror 26 and the concave mirror 27, and heading to the windshield 18 passes. In addition, the optical isolator 70 is provided at a position where external light that enters from the outside of the vehicle 1 to the inside and is reflected by the concave mirror 27 and the plane mirror 26 and heading to the image generating unit 24 passes.

[0131] Figure 3 is a cross-sectional view of the optical isolator 70 .

[0132] The optical isolator 70 is a member that can transmit light emitted from the image generating unit 24 but blocks external light from outside the vehicle 1 to prevent the external light from entering the image generating unit 24. Figure 2 as well as Figure 3 As shown, the optical isolator 70 includes two polarizers (a first polarizer 71 and a second polarizer 72) and a Faraday element 73. The Faraday element 73 is disposed between the first polarizer 71 and the second polarizer 72 on the optical path of light emitted from the image generating unit 24.

[0133] The first polarizing plate 71 (an example of a first polarizer) and the second polarizing plate 72 (an example of a second polarizer) transmit only light polarized in a specific direction, and are, for example, composed of linear polarizers that converge the vibration direction of the transmitted light in a certain direction. As the first polarizing plate 71 and the second polarizing plate 72, for example, polarizing glass, a polarizing beam splitter (PBS), a prism-type polarizer using birefringent crystals, a wire grid-type polarizer, etc. can be used. The first polarizing plate 71 is configured to transmit only light having a specific vibration direction component. In addition, the second polarizing plate 72 is configured to transmit only light having a vibration direction component different from the specific vibration direction component transmitted by the first polarizing plate 71. The first polarizing plate 71 and the second polarizing plate 72 can be configured as an absorption-type polarizing plate that removes polarization components in unnecessary directions from the optical path by absorption, or can be configured as a reflection-type polarizing plate that reflects polarization components in unnecessary directions toward the incident direction. However, as in the present embodiment, when the optical isolator 70 is disposed at the position of the exit window 23 of the HUD main body 21, it is preferable to use an absorption type polarizing plate that does not cause the reflected light from the optical isolator 70 to become glare. It should be noted that the first polarizing plate 71 and the second polarizing plate 72 may include a filter for blocking at least one of ultraviolet rays and infrared rays.

[0134] The Faraday element 73 includes a frame 74, a Faraday rotator 75, and a magnet 76. The frame 74 is formed in a cylindrical shape, and contains the Faraday rotator 75 and the magnet 76 therein. The frame 74 is made of a magnetic material such as Fe. The frame 74 is not only used to protect the Faraday rotator 75 and the magnet 76, but also functions as a yoke (yoke iron) for inducing the magnetic flux of the magnet 76.

[0135] The Faraday rotator 75 includes a base layer 75A, a Faraday layer 75B provided on the base layer 75A, and a protective layer 75C provided on the Faraday layer 75B. The base layer 75A is made of a transparent body that is not easily deformed, such as glass or a crystal material.

[0136] The Faraday layer 75B is a layer made of a material that exerts a Faraday effect that rotates the polarization direction of light when a magnetic field is applied. The material constituting the Faraday layer 75B is not particularly limited, and for example, bismuth-substituted rare earth iron garnet (RBi)3Fe5O 12 ), yttrium iron garnet (Y3Fe5O 12 ), terbium gallium garnet (Tb3Ga5O 12 ), Faraday rotation glass, etc. It should be noted that as the Faraday layer 75B, a material having a nanoparticle structure composed of a fluoride substrate and nanometer-sized magnetic metal particles can be used. As a material having a nanoparticle structure, for example, Fe 26 Al 28 F46 , Fe 13 Co 10 Al 22 F 55 , Fe 25 Y 23 F 52 , Fe 21 Co 14 Y 24 F 41 , Bi-YIG, etc.

[0137] The protective layer 75C is provided to cover the Faraday layer 75B in order to prevent degradation of the Faraday layer 75B. The protective layer 75C is made of SiO 2 , for example.

[0138] The magnet 76 is used to apply a magnetic field to the Faraday rotator 75. The magnet 76 is arranged around the Faraday rotator 75. The magnet 76 can use, for example, a single cylindrical magnet. In the case of a cylindrical magnet, the Faraday rotator 75 is arranged at a position corresponding to its center hole. As the magnet 76, for example, a permanent magnet can be used. It should be noted that as the magnet 76, a pair of magnets formed by configuring a Faraday rotator therebetween can be used in combination. When using a pair of magnets, the directions of the magnetic field applied to the Faraday rotator 75 need to be in the same direction as each other.

[0139] Figure 4 It is a schematic diagram for explaining the magnetic field (magnetic force field) applied to the Faraday element 73 of the optical isolator 70 .

[0140] like Figure 4 As shown, for example, the magnet 76 is configured such that one end portion on the side in contact with the frame 74 is an S pole, and the other end portion (the end portion on the side close to the Faraday rotator 75) is an N pole. In addition, the frame 74 composed of a magnetic body is formed in a shape in which both ends (end faces 74A, 74B) are inwardly entered in a cross-sectional view, that is, a U-shaped shape is formed to face each other. Therefore, the magnetic lines of force F emitted from the N pole side of the magnet 76 go to the end face 74A on the second polarizing plate 72 side of the frame 74, pass through the frame 74 from the end face 74A, come out from the end face 74B on the first polarizing plate 71 side, and return to the N pole. As a result, the magnetic lines of force F formed by the magnet 76 and the frame 74 pass through the Faraday rotator 75 along the direction D from the first polarizing plate 71 to the second polarizing plate 72.

[0141] In this way, at least a portion of the Faraday rotator 75 is covered by the frame 74 made of a magnetic body. The frame 74 is configured to form a so-called yoke structure. As a result, the Faraday rotator 75 can be arranged in a magnetic field in a desired direction as shown by the magnetic field lines F. In addition, since the magnetic field can be suppressed from leaking out of the frame 74, it is possible to prevent adverse effects on components other than the Faraday element 73.

[0142] Next, refer to Figure 2 , Figures 5 to 8 The function of the optical isolator 70 will be described. Figure 5 as well as Figure 6 This is a schematic diagram for explaining the function of the optical isolator 70 . Figure 7 This is a diagram showing a state where external light enters a HUD that does not include an optical isolator. Figure 8 1 is a diagram showing a state in which external light enters the HUD 20 according to the present embodiment.

[0143] It should be noted that in Figure 5 as well as Figure 6 For ease of explanation, the size of the Faraday rotator 75 (especially, the length along the direction in which light travels) is shown exaggerated.

[0144] First, if Figure 2 As shown in FIG. 1 , the light emitted from the image generating unit 24 is reflected by the plane mirror 26 and the concave mirror 27 and enters the first polarizing plate 71 of the optical isolator 70. Figure 5 As shown, the first polarizing plate 71 transmits only light having a specific vibration direction component among the light L1a emitted from the image generating unit 24, and emits it toward the Faraday element 73. Specifically, when the unpolarized light emitted from the image generating unit 24 passes through the first polarizing plate 71, the first polarizing plate 71 absorbs, for example, the horizontal direction component of the electric field. As a result, the light L1b that passes through the first polarizing plate 71 forms linear polarization having only a vertical direction component.

[0145] Next, the light (linearly polarized light having only a vertical component) L1b emitted from the first polarizing plate 71 is incident on the Faraday element 73 (the Faraday rotator 75). Figure 4 As described above, the magnetic force lines F passing through the Faraday rotator 75 are along the direction D from the first polarizing plate 71 to the second polarizing plate 72. That is, the traveling direction of the light L1b incident on the Faraday rotator is consistent with the direction of the magnetic field (magnetic field) applied to the Faraday rotator 75. Therefore, due to the Faraday effect of the Faraday layer 75B, the linearly polarized light having only the vertical direction component, that is, the light L1b, for example, becomes the light L1c rotated 45° clockwise and is emitted from the Faraday rotator 75.

[0146] Next, the light L1c whose polarization plane is rotated 45° clockwise by the Faraday rotator 75 enters the second polarizing plate 72. The second polarizing plate 72 is set so that its polarization direction forms an orientation that allows the light L1c rotated 45° clockwise to pass through. That is, the light that can pass through the second polarizing plate 72 is the light that is rotated 45° clockwise relative to the light having only the vertical direction component that passes through the first polarizing plate 71. Therefore, the light L1c that is rotated 45° clockwise by the Faraday rotator 75 directly passes through the second polarizing plate 72 and is irradiated to the windshield 18.

[0147] return Figure 2 , part of the light that passes through the Faraday element 73 (the first polarizing plate 71, the Faraday element 73, and the second polarizing plate 72) and irradiates the windshield 18 is reflected toward the passenger's viewpoint E. As a result, the passenger recognizes the light emitted from the HUD main body 21 as a virtual image (an example of a predetermined image) formed at a predetermined distance in front of the windshield 18. In this way, as a result of the image displayed by the HUD 20 being overlapped with the real space in front of the vehicle 1 through the windshield 18, the passenger can visually recognize that the virtual image target I formed by the virtual image (image) is suspended on the road outside the vehicle.

[0148] Here, the viewpoint E of the passenger may be either the viewpoint of the left eye or the viewpoint of the right eye of the passenger. Alternatively, the viewpoint E may be defined as the midpoint of a line segment connecting the viewpoint of the left eye and the viewpoint of the right eye. The position of the viewpoint E of the passenger is determined, for example, based on image data acquired by the internal camera 6B. The position of the viewpoint E of the passenger may be updated at a predetermined period or may be determined once when the vehicle 1 is started.

[0149] When a 2D image (plane image) is formed as the virtual image target I, the projection is performed in such a manner that a predetermined image forms a virtual image of a single distance determined arbitrarily. When a 3D image (stereoscopic image) is formed as the virtual image target I, the projection is performed in such a manner that a plurality of predetermined images that are the same or different from each other form virtual images of different distances. In addition, the distance of the virtual image target I (the distance from the passenger's viewpoint E to the virtual image) can be appropriately adjusted by adjusting the optical distance (optical path length) from the image generating unit 24 to the passenger's viewpoint E (for example, adjusting the distance between the image generating unit 24 and the concave mirror 27).

[0150] On the other hand, Figure 6As shown, when light L2a traveling in the opposite direction to the light emitted from the image generating unit 24 (hereinafter referred to as return light) enters the second polarizing plate 72 of the optical isolator 70, light L2b having only a specific direction component in the return light L2a is emitted through the second polarizing plate 72. As described above, the light L2b that can pass through the second polarizing plate 72 is light that is rotated 45° clockwise as viewed from the first polarizing plate 71 and the Faraday element 73 side with respect to the light having only a vertical direction component that passes through the first polarizing plate 71 (that is, light that is rotated 45° counterclockwise as viewed from the traveling direction of the return light L2a).

[0151] Next, the return light L2b emitted from the second polarizing plate 72 and incident on the Faraday rotator 75 is rotated in the direction opposite to the rotation direction of the light L1b emitted from the image generating unit 24. That is, the return light L2b incident on the Faraday rotator 75 is rotated 45° counterclockwise with respect to the traveling direction of the return light L2b. Therefore, the return light L2c emitted from the Faraday rotator 75 is light having only a horizontal component after being rotated 90° with respect to the light L1b having only a vertical component emitted from the image generating unit 24 and transmitted through the first polarizing plate 71.

[0152] Next, the return light L2c having only the horizontal direction component emitted from the Faraday rotator 75 is incident on the first polarizing plate 71. However, the return light L2c is absorbed by the first polarizing plate 71 and does not pass through the first polarizing plate 71. This is because, as described above, the return light L2c incident on the first polarizing plate 71 forms a direction different from the polarization direction of the light that can pass through the first polarizing plate 71, that is, forms linear polarization having only the horizontal direction component after being rotated 90° with respect to the light L1b having only the vertical direction component emitted from the image generating unit 24 and passing through the first polarizing plate 71.

[0153] However, if Figure 7 As shown, if it is not set Figure 2 In the case of the HUD 20A having the optical isolator 70 as shown in FIG. 1 , when external light such as sunlight entering from the outside of the vehicle enters the housing 22 from the exit window 23, the external light is sometimes reflected and focused by the concave mirror 27 and the plane mirror 26 and irradiated to the image generating unit 24. When the external light after the above-mentioned focus is irradiated to the image generating unit 24 (the light emitting surface), the image generating unit 24 may be degraded due to thermal damage caused by excessive temperature rise in the light emitting surface due to far infrared rays included in the external light.

[0154] In contrast, the HUD 20 according to the present embodiment includes: an image generating unit 24 (an example of a light source); a concave mirror 27 (an example of an optical component) that amplifies the light emitted from the image generating unit 24 by transmitting or reflecting the light and irradiates the light to the outside; and an optical isolator 70 that transmits the light emitted from the image generating unit 24 but prevents external light from outside the vehicle from entering the image generating unit 24. In addition, in the HUD 20, the optical isolator 70 is arranged at a position between the concave mirror 27 and the windshield 18 where the light emitted from the image generating unit 24 passes. Thus, as shown in FIG. Figure 8 As shown in FIG. 1 , the optical isolator 70 can prevent external light from entering the image generating unit 24. Therefore, the occurrence of thermal damage can be prevented. Figure 5 The optical isolator 70 can transmit the light emitted from the image generating unit 24, and thus does not reduce the image generating function (light emitting function).

[0155] The optical isolator 70 in this embodiment includes: a first polarizing plate 71 that polarizes the light L1a emitted from the image generating unit 24 in, for example, a vertical direction (an example of a first direction); a Faraday element 73 that emits the light L1b polarized by the first polarizing plate 71 from the vertical direction as light L1c rotated 45° clockwise from the traveling direction of the light L1b (an example of a second direction) by the Faraday effect generated by the application of a magnetic field; and a second polarizing plate 72 that transmits the light L1c rotated by the Faraday element 73. The Faraday element 73 is configured to transmit the return light L2b polarized by the second polarizing plate 72, which is return light (for example, external light) in a direction opposite to the traveling direction of the light L1a emitted from the image generating unit 24, and then emit it in a horizontal direction (an example of a third direction). The return light L2c having only the horizontal component reaches the image generating unit 24 without being blocked by the first polarizing plate 71. In this way, the external light incident on the image generating unit 24 can be cut off with a simple configuration, thereby preventing thermal damage.

[0156] The Faraday element 73 (Faraday rotator 75 ) includes a base layer 75A, a Faraday layer 75B provided on the base layer 75A, and a protective layer 75C provided on the Faraday layer 75B. Thus, the Faraday rotator 75 can be prevented from being deteriorated.

[0157] It should be noted that, as described above, at least one of the first polarizer 71 and the second polarizer 72 may include a filter for blocking at least one of ultraviolet rays and infrared rays. This can expand the band required by the Faraday element 73, that is, reduce the wavelength dependence of the Faraday element 73.

[0158] (First Modification)

[0159] Fig. 9 It is a schematic diagram showing the structure of a HUD 20B according to a first modification example of the first embodiment.

[0160] exist Fig. 9 In the HUD 20B shown, the optical isolator 170 is arranged between the image generating unit 24 and the plane mirror 26, which is different from the HUD 20 of the first embodiment in which the optical isolator 7 is arranged between the concave mirror 27 and the windshield 18. In this way, by arranging the optical isolator 170 between the image generating unit 24 and the plane mirror 26, it is possible to block the external light entering the image generating unit 24 without damaging the emission function of the light emitted from the image generating unit 24. It should be noted that in the case of this modified example, it is preferred that the first polarizer 171 and the second polarizer 172 of the optical isolator 170 are not configured as absorption-type polarizers, but as reflection-type polarizers. By adopting a reflection-type polarizer, the heat rise in the HUD main body 21 can be suppressed. It should be noted that compared with the optical isolator 70 of the first embodiment, the optical isolator 170 is arranged at a position close to the image generating unit 24 (that is, close to the center of the HUD main body 21). Therefore, when a reflective polarizer is used for the first polarizing plate 171 and the second polarizing plate 172 , the possibility of generating glare is also low.

[0161] (Second Modification)

[0162] Fig.10 It is a schematic diagram showing the structure of a HUD 20C according to a second modification example of the first embodiment.

[0163] like Fig.10 As shown in FIG. 1 , the HUD 20C involved in the modification example is composed of a HUD main body 21 and a synthesizer 19. The synthesizer 19 is a structure separate from the windshield 18 and is provided on the inner side of the windshield 18. The synthesizer 19 is, for example, a transparent plastic plate, and irradiates light reflected by the plane mirror 26 and the concave mirror 27 and transmitted through the optical isolator 70 instead of the windshield 18. As a result, as in the case of irradiating light to the windshield 18, a part of the light irradiated from the HUD main body 21 to the synthesizer 19 is reflected toward the viewpoint E of the passenger. As a result, the passenger can recognize the emitted light (predetermined image) from the HUD main body 21 as a virtual image target I formed at a predetermined distance in front of the synthesizer 19 (and the windshield 18). In the case of the HUD 20C having such a synthesizer 19, the same effect as the HUD 20 of the first embodiment can be achieved.

[0164] (Second Embodiment)

[0165] Fig.11It is a schematic diagram for explaining a vehicle lamp 300 according to the second embodiment.

[0166] like Fig.11 As shown, a vehicle lamp 300 (an example of a light emitting device) includes a lamp housing 301 and a transmissive cover 302 (an example of an outer lens) installed to cover the opening of the lamp housing 301. An extension portion 304 and a light source unit 310 are provided in a lamp chamber 303 formed by the lamp housing 301 and the transmissive cover 302. In addition, an electronic unit 305 is installed on the outer bottom surface of the lamp housing 301 as a lighting control unit that controls the lighting state of the light source (LED 312) mounted on the light source unit 310.

[0167] The light source unit 310 is a so-called projection type lamp unit, and includes a unit base 311 and an LED 312 as a light source provided on the unit base 311. The light source unit 310 also includes a reflector 313 provided to cover the LED 312, an optical isolator 314 provided in front of the LED 312, and a projection lens 315 provided in front of the optical isolator 314.

[0168] Although not shown in the figure, the optical isolator 314 has the same structure as the optical isolator 70 of the first embodiment. That is, the optical isolator 314 has a first polarizing plate, a second polarizing plate, and a Faraday element. The Faraday element is arranged between the first polarizing plate and the second polarizing plate on the optical path of the light emitted from the LED 312.

[0169] According to the vehicle lamp 300 configured in this way, the optical isolator 314 is arranged at a position where the light emitted from the LED 312 passes between the LED 312 and the projection lens 315. Thus, since the external light does not enter the LED 312, the occurrence of heat damage can be prevented. In addition, the light emitted from the LED 312 can be transmitted through the optical isolator 314 and emitted to the front of the vehicle lamp 300 via the projection lens 315 and the transmission cover 302. Therefore, the light emitting function of the LED 312 will not be damaged.

[0170] (Third Embodiment)

[0171] Fig.12 1 is a schematic diagram of the HUD 120 according to the third embodiment as viewed from the side of the vehicle 1. It should be noted that in the description of the third embodiment, for the convenience of description, the description of the components having the same reference numerals as those already described in the description of the first embodiment will be omitted. Fig.12In the example shown, the HUD 120 includes a HUD main body 21. The HUD main body 21 includes a housing 22 and an exit window 23. The HUD main body 21 includes an image generating unit 24, a control unit 25, and a concave mirror 30 (an example of a reflecting unit) inside the housing 22.

[0172] The image generation unit 24 is configured to emit light for generating a predetermined image for displaying HUD information. The predetermined image includes a first image for displaying the first HUD information and a second image for displaying the second HUD information. That is, the image generation unit 24 is configured to emit a first light for generating the first image and a second light for generating the second image.

[0173] The concave mirror 30 is arranged on the optical path of the light emitted from the display device of the image generating unit 24. The concave mirror 30 reflects the light emitted from the image generating unit 24 toward the windshield 18 (for example, the front window of the vehicle 1). The concave mirror 30 has a reflecting surface 31 curved in a concave shape to form a virtual image, and reflects the image of the light emitted from the image generating unit 24 and formed at a predetermined magnification.

[0174] The reflecting surface 31 includes a first reflecting area 31A and a second reflecting area 31B. The first reflecting area 31A reflects the first light emitted from the image generating unit 24 for generating the first image. The second reflecting area 31B reflects the second light emitted from the image generating unit 24 for generating the second image. The image generating unit 24 includes a first image area for emitting the first light irradiated to the first reflecting area 31A and a second image area for emitting the second light irradiated to the second reflecting area 31B. It should be noted that the control unit 25 controls the image generating action of the first image area and the second image area in the image generating unit 24 to irradiate the first light to the first reflecting area 31A and irradiate the second light to the second reflecting area 31B.

[0175] The light reflected by the concave mirror 30 and emitted from the exit window 23 of the HUD main body 21 is irradiated toward the windshield 18. A portion of the light irradiated from the HUD main body 21 toward the windshield 18 is reflected toward the viewpoint E of the passenger. As a result, the passenger recognizes the light emitted from the HUD main body 21 as a virtual image (an example of a predetermined image) formed at a predetermined distance in front of the windshield 18. In this way, as a result of the predetermined image displayed by the HUD 20 being overlapped with the real space in front of the vehicle 1 through the windshield 18, the passenger can visually recognize that the virtual image target I formed by the predetermined image is suspended on the road outside the vehicle.

[0176] The second reflection region 31B of the reflection surface 31 of the concave mirror 30 has a second surface roughness that is rougher than the first surface roughness of the first reflection region 31A. Thus, in the virtual image target I, the virtual image of the first image formed by the light reflected by the first reflection region 31A is recognized as a virtual image having a higher image quality than the virtual image of the second image formed by the light reflected by the second reflection region 31B.

[0177] Next, use Figures 13A to 13C The specific structure of the concave mirror 30 according to the third embodiment will be described. Fig.13A This is a schematic diagram of the concave mirror 30 according to the third embodiment as viewed from the image generation unit 24. Fig.13A In FIG. 1 , the dotted line indicates the boundary between the first reflection area 31A and the second reflection area 31B. Fig. 13B Observed from the direction of the arrow along line IIIB-IIIB Fig.13A A cross-sectional view of the concave mirror 30 as seen in FIG. Fig. 13C Yes means Fig. 13B A partial enlarged view of region IIIC in FIG. Fig. 13C In FIG. 1 , two-dot chain lines indicate boundaries between regions 41a and 42a of the rear surface 40a of the base member 40 and regions 51a and 52a of the rear surface 50a of the reflection film 50 corresponding to the first reflection region 31A and the second reflection region 31B.

[0178] like Fig.13A In the example shown, the concave mirror 30 is formed so that the first reflection region 31A and the second reflection region 31B are arranged side by side in the vertical direction of the vehicle.

[0179] For example, Fig. 13B In the illustrated example, the concave mirror 30 includes a base member 40 and a reflective film 50 formed on the base member 40 .

[0180] The base member 40 is formed of, for example, a thermoplastic resin such as polycarbonate, glass, or the like. The base member 40 is formed such that the rear surface (the surface on which the reflection film 50 is formed) 40a thereof has different surface roughnesses between the regions corresponding to the first reflection region 31A and the second reflection region 31B. Specifically, Fig. 13C As shown in the example, the rear surface 40a of the base member 40 has a region 41a corresponding to the first reflection region 31A and a region 42a corresponding to the second reflection region 31B. Moreover, the rear surface 40a is formed so that the surface roughness of the region 41a is smoother than the surface roughness of the region 42a. For example, the base member 40 can be formed by injection molding a thermoplastic resin using a mold formed in such a manner that the roughness of the surface of the region 41a forming the rear surface 40a is smoother than the roughness of the surface of the region 42a forming the rear surface 40a.

[0181] The reflective film 50 is formed of a metal such as aluminum. The reflective film 50 is formed so that its rear surface 50a has different surface roughness between the regions corresponding to the first reflective region 31A and the second reflective region 31B. Fig. 13C As shown in the example, the rear surface 50a of the reflective film 50 has a region 51a forming the first reflective region 31A, and a region 52a forming the second reflective region 31B. Moreover, the rear surface 50a is formed so that the surface roughness of the region 51a is smoother than the surface roughness of the region 52a. Here, the rear surface 50a of the reflective film 50 forms the reflective surface 31 that reflects the light emitted from the image generating unit 24. Therefore, the surface roughness of the region 52a, that is, the surface roughness of the second reflective region 31B, is rougher than the surface roughness of the region 51a, that is, the surface roughness of the first reflective region 31A. For example, the reflective film 50 can be formed by vapor-depositing a metal such as aluminum on the base member 40. The thickness of the reflective film 50 formed by the vapor-deposited film is thin, and it will be affected by the surface roughness of the rear surface 40a of the base member 40, so it is possible to form a rear surface 50a having different surface roughness between the region 51a and the region 52a.

[0182] Fig.14 1 is a schematic diagram illustrating an area 60 illuminated by light emitted from the HUD 120 in the windshield 18. Fig.14 In FIG. 1 , a dashed line C indicates a center line extending in the horizontal direction through the vertical center of the windshield 18 .

[0183] like Fig.14 In the example shown in FIG. 1 , when the light emitted from the HUD 120 is irradiated to the area 60 of the windshield 18 located below the center line C, as shown in FIG. Fig.13A In the example shown, for example, the first reflection region 31A of the concave mirror 30 is formed to be located below the second reflection region 31B. Fig.14 In the illustrated example, the first light reflected by the first reflection region 31A is irradiated to the region 60A of the windshield 18. In addition, the second light reflected by the second reflection region 31B is irradiated to the region 60B of the windshield 18 located below the region 60A.

[0184] As described above, the HUD 120 involved in the third embodiment includes an image generating unit 24 that emits a first light for generating a first image in a predetermined image and a second light for generating a second image in a predetermined image. In addition, the HUD 120 includes a concave mirror 30 as a reflecting mirror that reflects the first light and the second light, so that the first light and the second light emitted by the image generating unit 24 are irradiated to the windshield 18. The concave mirror 30 has a reflecting surface 31 including a first reflecting area 31A that reflects the first light and a second reflecting area 31B that reflects the second light. The first reflecting area 31A has a first surface roughness, and the second reflecting area 31B has a second surface roughness that is rougher than the first surface roughness. According to the above-mentioned structure, the second reflecting area 31B has a rougher surface roughness than the first reflecting area 31A, so it can be formed at a lower cost than the first reflecting area 31A. On the other hand, the first reflecting area 31A has a smoother surface roughness than the second reflecting area 31B, so the first image is recognized as a high-quality virtual image. Therefore, a concave mirror can be realized at low cost without significantly reducing the quality of the virtual image.

[0185] In addition, the concave mirror 30 has a base member 40 and a reflective film 50 formed on the base member 40. The rear surface 50a of the reflective film 50 forms the reflective surface 31. The surface roughness of the base member 40 (region 42a of the rear surface 40a) corresponding to the second reflection area 31B is rougher than the surface roughness of the base member 40 (region 41a of the rear surface 40a) corresponding to the first reflection area 31A. The reflective film 50 (rear surface 50a) is affected by the surface roughness of the base member 40, and the surface roughness changes according to the reflection area. According to this configuration, by changing the surface roughness of the base member 40 according to the reflection area, it is possible to easily form a reflective film 50 having a surface roughness that is different according to the reflection area.

[0186] In addition, if Fig.14In the example shown, the first light reflected by the first reflection area 31A is irradiated to an area 60A above the area 60B of the windshield 18 irradiated by the second light reflected by the second reflection area 31B. That is, the first reflection area 31A and the second reflection area 31B are arranged side by side on the windshield 18 along the vertical direction of the vehicle so that the first light used to generate the first image is irradiated to a position closer to the vertical center of the windshield 18 than the second light used to generate the second image. According to this configuration, the driver can recognize the virtual image of the first image at a position closer to the vertical center of the windshield 18 than the virtual image of the second image. The driver is more likely to direct his sight toward the area close to the center in the vertical direction of the windshield 18 while the vehicle is driving. Therefore, the driver can recognize the virtual image of the first image with high image quality while the sight is basically still while the vehicle is driving. As a result, the driver can accurately grasp the information represented by the first image. In addition, the driver can recognize the virtual image of the second image only by moving the sight from the virtual image of the first image in the up and down direction.

[0187] For example, the first image represents important information related to the driving of the vehicle, and the second image represents incidental information. The important information related to the driving of the vehicle refers to, for example, vehicle driving information and information on objects existing outside the vehicle. The incidental information refers to information such as attention-calling. In this case, the driver can accurately grasp the important information through a high-quality virtual image. In addition, the driver can confirm the incidental information only by moving the line of sight in the up and down directions as needed. The incidental information is expressed, for example, by using images of large-sized marks and symbols that are not easily affected by the image quality, so that the driver can confirm both the important information and the incidental information without a sense of disharmony. Therefore, compared with the case where the concave mirror is set as a whole to have a smooth surface roughness, a low-cost concave mirror with almost unchanged information transmission function can be provided.

[0188] (Variation Example)

[0189] It should be noted that in the third embodiment, the surface roughness of the base member 40 is changed according to the reflection area, so that the concave mirror 30 whose reflection surface 31 has different surface roughness according to the reflection area is formed, but the present invention is not limited to this. Fig.15A This is a schematic diagram illustrating a concave mirror 130 according to a modified example of the third embodiment. Fig. 15B It is a cross-sectional view of the concave mirror 130 observed from the direction of the arrow along the VB-VB line.

[0190] The concave mirror 130 of the modified example has a reflecting surface 131 facing the image generating unit 24. Fig.15AIn the illustrated example, the reflective surface 131 is formed to include a first reflective region 131A having a first surface roughness and a second reflective region 131B having a second surface roughness coarser than the first surface roughness.

[0191] In addition, if Fig. 15B In the example shown, the concave mirror 130 includes a base member 140 and a reflective film 150 formed on the base member 140. The base member 140 includes a first base member 141 and a second base member 142. The reflective film 150 includes a first reflective film 151 formed on the first base member 141 and a second reflective film 152 formed on the second base member 142. The first reflective film 151 and the second reflective film 152 are formed of, for example, a metal such as aluminum. For example, the first reflective film 151 is formed by vapor-depositing a metal such as aluminum on the first base member 141. The second reflective film 152 is formed by vapor-depositing a metal such as aluminum on the second base member 142. Here, the rear surface of the reflective film 150 forms a reflective surface 131 that reflects light emitted from the image generating unit 24. Therefore, the rear surface 151a of the first reflective film 151 forms a first reflective region 131A. The rear surface 152a of the second reflective film 152 forms a second reflective region 131B.

[0192] The first base member 141 and the second base member 142 are formed of different materials so that the second reflection region 131B has a second surface roughness that is rougher than the first surface roughness of the first reflection region 131A. For example, the first base member 141 is formed of glass, and the second base member 142 is formed of a thermoplastic resin such as polycarbonate. Glass can process its surface with higher precision than thermoplastic resin. Therefore, the surface roughness of the rear surface 142a of the second base member 142 formed of thermoplastic resin is formed to be rougher than the surface roughness of the rear surface 141a of the first base member 141 formed of high-precision glass. The reflective film 150 is affected by the surfaces of the rear surfaces 141a and 142a of the base member 140, and the surface roughness of its rear surfaces 151a and 152a will change. Therefore, the surface roughness of the rear surface 152a, that is, the surface roughness of the second reflection region 131B is rougher than the surface roughness of the rear surface 151a, that is, the surface roughness of the first reflection region 131A.

[0193] Thus, the concave mirror 130 of the modified example has a first base member 141 and a second base member 142 formed of different materials. The reflective film 150 is affected by the surface of the base member 140, and the surface roughness changes according to the reflection area. According to this configuration, by changing the material of the base member 140 according to the reflection area, it is possible to easily form a reflective film 150 having different surface roughness according to the reflection area.

[0194] It should be noted that the surface roughness of the concave mirror 130 may be further adjusted so that the first base member 141 and the second base member 142 each have a desired surface roughness, as in the concave mirror 30 of the third embodiment.

[0195] (Fourth Embodiment)

[0196] Next, use Fig.16A as well as Fig. 16B The specific structure of the concave mirror 230 according to the fourth embodiment will be described. Fig.16A This is a schematic diagram of the concave mirror 230 according to the fourth embodiment as viewed from the image generating unit 24 . Fig. 16B Observed from the direction of the arrow along the VIB-VIB line Fig.16A A cross-sectional view of the concave mirror 230. Fig.16A In FIG. 2 , dotted lines indicate boundaries among the first reflective region 231A, the second reflective region 231B, and the third reflective region 231C.

[0197] The image generation unit 24 of the fourth embodiment is configured to emit light for generating a predetermined image including a first image, a second image, and a third image for displaying HUD information. That is, the image generation unit 24 is configured to emit a first light for generating a first image, a second light for generating a second image, and a third light for generating a third image.

[0198] The concave mirror 230 has a reflecting surface 231 facing the image generating unit 24. Fig.16A In the example shown, the reflecting surface 231 is configured to include a first reflecting area 231A, a second reflecting area 231B, and a third reflecting area 231C arranged side by side in the horizontal direction of the vehicle. The first reflecting area 231A is configured to reflect the first light emitted from the image generating unit 24. The second reflecting area 231B is configured to reflect the second light emitted from the image generating unit 24. The third reflecting area 231C is configured to reflect the third light emitted from the image generating unit 24. It should be noted that the control unit 25 controls the operation of the image generating unit 24 to irradiate the first light, the second light, and the third light to the first reflecting area 231A, the second reflecting area 231B, and the third reflecting area 231C.

[0199] The first reflection region 231A, the second reflection region 231B, and the third reflection region 231C are formed to have different surface roughnesses. Specifically, the second reflection region 231B has a second surface roughness that is rougher than the first surface roughness of the first reflection region 231A. In addition, the third reflection region 231C has a third surface roughness that is rougher than the first surface roughness of the first reflection region 231A. That is, the virtual image of the first image formed by the light reflected by the first reflection region 231A is recognized as a virtual image having a higher image quality than the virtual image of the second image formed by the light reflected by the second reflection region 231B. In addition, the virtual image of the first image formed by the light reflected by the first reflection region 231A is recognized as a virtual image having a higher image quality than the virtual image of the third image formed by the light reflected by the third reflection region 231C.

[0200] like Fig. 16B In the example shown, the concave mirror 230 includes a base member 240 and a reflective film 250 formed on the base member 240. The base member 240 is formed of, for example, a thermoplastic resin such as polycarbonate, glass, etc. The reflective film 250 is formed of, for example, a metal such as aluminum. As in the third embodiment and its modified example, by making the surface roughness and / or material of the base member 240 different, the surface roughness of the first reflective region 231A, the second reflective region 231B, and the third reflective region 231C are made different.

[0201] Fig.17 1 is a schematic diagram illustrating an area 160 illuminated by light emitted from the HUD 120 in the windshield 18. Fig.17 As shown in the example, when the light emitted from the HUD 120 hits the area 160 in the windshield 18, Fig.16A In the example shown, the concave mirror 230 is formed so that the second reflection area 231B is located on the left side of the first reflection area 231A in the horizontal direction of the vehicle, and the third reflection area 231C is located on the right side of the first reflection area 231A. Thus, the first light for generating the first image reflected in the first reflection area 231A is irradiated to the area 160A. The second light for generating the second image reflected in the second reflection area 231B is irradiated to the area 160B located on the left side of the area 160A in the horizontal direction of the windshield 18. The third light for generating the third image reflected in the third reflection area 231C is irradiated to the area 160C located on the right side of the area 160A in the horizontal direction of the windshield 18.

[0202] In this way, the reflecting surface 231 of the concave mirror 230 involved in the fourth embodiment also has a third reflecting area 231C for reflecting the third light used to generate the third image in the predetermined image. The third reflecting area 231C has a third surface roughness that is rougher than the first surface roughness of the first reflecting area 231A. The first reflecting area 231A, the second reflecting area 231B and the third reflecting area 231C are arranged side by side along the horizontal direction of the vehicle in a state where the first reflecting area 131A is sandwiched between the second reflecting area 231B and the third reflecting area 231C. According to this configuration, the driver can recognize the virtual image of each image only by moving the line of sight left and right during the driving of the vehicle. For example, the first image may represent important information related to the driving of the vehicle, and the second image and the third image may represent the accompanying information. In this case, the driver can accurately grasp the important information through the high-quality virtual image. In addition, the driver who has grasped the important information related to the driving of the vehicle can confirm the accompanying information only by moving the line of sight left and right as needed. Therefore, compared with the case where the entire concave mirror is configured to have a smooth surface roughness, a low-cost concave mirror with almost no change in the information transmission function can be provided.

[0203] It should be noted that the concave mirror 230 can be formed by only two first reflection areas 231A and a second reflection area 231B arranged side by side in the horizontal direction. For example, the first reflection area 231A and the second reflection area 231B are arranged to recognize the virtual image of the first image at a position in the horizontal direction of the windshield 18 where the driver observes it with high frequency. According to the above-mentioned structure, the driver can recognize the virtual image of the first image with high image quality without almost moving the line of sight during the driving of the vehicle. As a result, the driver can accurately grasp the information represented by the first image. In addition, the driver can recognize the virtual image of the second image only by moving the line of sight from the virtual image of the first image in the left-right direction.

[0204] (Fifth Embodiment)

[0205] Fig.18 It is a schematic diagram of the HUD 220 viewed from the side of the vehicle 1. It should be noted that in the description of the fifth embodiment, for the convenience of description, the description of the components having the same reference numerals as those already described in the description of the first embodiment will be omitted. Fig.18 In the example shown, the HUD 220 includes a HUD main body 21. The HUD main body 21 includes a housing 22 and an exit window 23. The HUD main body 21 includes an image generating unit 24, a control unit 25, and a reflecting unit 126 inside the housing 22.

[0206] The image generation unit 24 is configured to emit light for generating a predetermined image to be displayed toward a passenger of the vehicle 1. The predetermined image includes a first image for displaying first HUD information and a second image for displaying second HUD information. The image generation unit 24 is configured to emit a first light for generating the first image and a second light for generating the second image.

[0207] The reflection unit 126 is disposed on an optical path of light emitted from the display device of the image generation unit 24. The reflection unit 126 reflects the light emitted from the image generation unit 24 toward the windshield 18 (for example, the front window of the vehicle 1).

[0208] The light reflected by the reflection portion 126 and emitted from the exit window 23 of the HUD main body 21 is irradiated to the windshield 18. A portion of the light irradiated from the HUD main body 21 to the windshield 18 is reflected toward the viewpoint E of the passenger. As a result, the passenger recognizes the light emitted from the HUD main body 21 as a virtual image (an example of a predetermined image) formed at a predetermined distance in front of the windshield 18. In this way, as a result of the image displayed by the HUD 20 being overlapped with the real space in front of the vehicle 1 through the windshield 18, the passenger can visually recognize that the virtual image targets Ia and Ib formed by the virtual image (image) are suspended on the road outside the vehicle.

[0209] The reflection unit 126 includes a concave mirror 126A and a plane mirror 126B. The concave mirror 126A has a concavely curved reflection surface to form a virtual image, and reflects the image of the light emitted from the image generating unit 24 at a predetermined magnification. The plane mirror 126B has a flat reflection surface to form a virtual image, and reflects the image of the light emitted from the image generating unit 24 at the same magnification. Fig.19 In the example shown, the concave mirror 126A and the plane mirror 126B are arranged side by side in the vertical direction of the vehicle 1 in such a manner that the concave mirror 126A is located at a lower side than the plane mirror 126B. The image generating unit 24 includes a first image area for emitting the first light irradiated to the concave mirror 126A and a second image area for emitting the second light irradiated to the plane mirror 126B. The control unit 25 controls the image generating operation of the first image area and the second image area in the image generating unit 24 so that the first light is irradiated to the concave mirror 126A and the second light is irradiated to the plane mirror 126B.

[0210] For example, light (an example of the first light) emitted from point Pa1 on the light exit surface 24A of the image generating unit 24 enters the optical path La1, is reflected at point Pa2 on the concave mirror 126A, enters the optical path La2, and is emitted from the exit window 23 of the HUD main body 21 to the outside of the HUD 220. The light entering the optical path La2 passes through point Pa3 incident on the windshield 18, and forms a part of a virtual image target Ia (an example of the first image) formed by a predetermined image. The virtual image target Ia is formed at a position separated from the windshield 18 by a relatively long predetermined distance (for example, about 7 to 10 meters) in the forward direction.

[0211] On the other hand, the light (an example of the second light) emitted from the point Pb1 on the light exit surface 24A of the image generating unit 24 enters the optical path Lb1, is reflected at the point Pb2 on the plane mirror 126B, enters the optical path Lb2, and is emitted to the outside of the HUD 220 from the exit window 23 of the HUD main body 21. The light entering the optical path Lb2 passes through the point Pb3 incident on the windshield 18, and forms a part of the virtual image target Ib (an example of the second image) formed by a predetermined image. The virtual image target Ib is formed, for example, at a position separated from the windshield 18 forward by a distance shorter than the virtual image target Ia (for example, about 3 to 5 meters).

[0212] Fig. 20 2 is a schematic diagram illustrating an area 260 illuminated by light emitted from the HUD 220 in the windshield 18. Fig. 20 In FIG. 1 , a dashed line C indicates a center line extending in the horizontal direction through the vertical center of the windshield 18 .

[0213] like Fig. 20 In the example shown, the light emitted from the HUD 220 is irradiated to the area 260 located below the center line C in the windshield 18. The first light reflected by the concave mirror 126A is irradiated to the area 260A of the windshield 18. The second light reflected by the plane mirror 126B is irradiated to the area 260B of the windshield 18. That is, the first light reflected by the concave mirror 126A is irradiated to a position closer to the vertical center of the windshield 18 than the second light reflected by the plane mirror 126B on the windshield 18. As a result, the virtual image target 1a is formed at a position closer to the vertical center of the windshield 18 than the virtual image target 1b.

[0214] It should be noted that, when forming a 2D image (plane image) as the virtual image target Ia, Ib, the projection is performed in such a manner that the predetermined image forms a virtual image of a single distance determined arbitrarily. When forming a 3D image (stereoscopic image) as the virtual image target Ia, Ib, the projection is performed in such a manner that a plurality of predetermined images that are the same or different from each other form virtual images of different distances. In addition, the distance of the virtual image target Ia, Ib (the distance from the passenger's viewpoint E to the virtual image) can be appropriately adjusted by adjusting the optical distance (optical path length) from the image generating unit 24 to the passenger's viewpoint E (for example, adjusting the distance between the image generating unit 24 and the reflecting unit 126).

[0215] As described above, the HUD 220 involved in the fifth embodiment includes an image generating unit 24 that emits a first light for generating a first image in a predetermined image and a second light for generating a second image in a predetermined image. In addition, the HUD 220 includes a reflecting unit 126 that reflects the first light and the second light so that the first light and the second light emitted by the image generating unit 24 are irradiated toward the windshield 18. The reflecting unit 126 includes a concave mirror 126A that reflects the first light and a plane mirror 126B that reflects the second light. The concave mirror 126A needs to form a curved high-precision reflecting surface, so a high level of manufacturing technology is required, resulting in a high manufacturing cost, but since the plane mirror 126B can be manufactured relatively cheaply, it is formed at a low cost. Therefore, according to the above configuration, since the reflecting unit 126 is composed of the concave mirror 126A and the plane mirror 126B, the reflecting unit can be realized at a low cost.

[0216] In addition, the concave mirror 126A and the plane mirror 126B are arranged side by side in the vertical direction of the vehicle so that the first light is irradiated to a position on the windshield 18 that is closer to the vertical center of the windshield 18 than the second light. According to this configuration, the driver can recognize the virtual image of the first image at a position that is closer to the vertical center of the windshield 18 than the virtual image of the second image. The driver is more likely to direct his sight toward the area close to the center in the vertical direction of the windshield 18 while the vehicle is running. In addition, the virtual image of the first image formed by the first light reflected by the concave mirror 126A is at a longer distance from the position (viewpoint) of the driver's eyes than the virtual image of the second image formed by the second light reflected by the plane mirror 126B. Therefore, the driver can recognize the virtual image of the first image while the vehicle is running without almost moving his sight and almost moving the focus of his eyes. As a result, the driver can grasp the information represented by the first image in a moment. In addition, the driver can recognize the virtual image of the second image only by moving his sight from the virtual image of the first image in the up and down direction.

[0217] For example, the first image represents important information related to the driving of the vehicle, and the second image represents incidental information. The important information related to the driving of the vehicle refers to, for example, the driving information of the vehicle and information on objects existing outside the vehicle. The incidental information refers to, for example, information such as attention-calling. In this case, the driver can grasp the important information in a moment without almost moving his sight and without almost moving the focus of his eyes while the vehicle is driving. In addition, the driver can confirm the incidental information by simply moving his sight in the up and down directions as needed.

[0218] It should be noted that in Fig. 20 , the case where the light emitted from the HUD 220 is irradiated to the area 260 located below the center line C in the windshield 18 is shown, but the present invention is not limited thereto. The light emitted from the HUD 220 may be irradiated to the area located above the center line C in the windshield 18. In this case, the concave mirror 126A and the plane mirror 126B may be arranged side by side in the vertical direction of the vehicle 1 so that the concave mirror 126A is located above the plane mirror 126B. Thus, the first light reflected by the concave mirror 126A is irradiated to a position closer to the vertical center of the windshield 18 than the second light reflected by the plane mirror 126B on the windshield 18. As a result, the virtual image target Ia is formed at a position closer to the vertical center of the windshield 18 than the virtual image target Ib.

[0219] (Sixth Embodiment)

[0220] Fig.21 This is a schematic diagram of the HUD 220A viewed from the side of the vehicle 1 .

[0221] like Fig.21 As illustrated, the HUD 220A of the sixth embodiment is different from the HUD 220 of the fifth embodiment in that a lens 28 is disposed between the image generating unit 24 and the plane mirror 126B.

[0222] The lens 28 is configured to change the focal length of the light emitted from the light emitting surface 24A of the image generating unit 24. The lens 28 is provided at a position where the light emitted from the light emitting surface 24A of the image generating unit 24 and heading for the plane mirror 126B passes. The lens 28 includes, for example, a driving unit, and is configured to be able to change the distance between the lens 28 and the image generating unit 24 by a control signal generated by the control unit 25. Due to the movement of the lens 28, the focal length (apparent optical path length) of the light emitted from the image generating unit 24 changes, and the distance between the predetermined image displayed by the windshield 18 and the HUD 220A changes.

[0223] For example, light emitted from point Pa1 on the light emitting surface 24A of the image generating unit 24 enters the optical path La1, is reflected at point Pa2 on the concave mirror 126A, enters the optical path La2, and is emitted to the outside of the HUD 220A from the emission window 23 of the HUD main body 21. The light entering the optical path La2 passes through point Pa3 incident on the windshield 18, and forms a part of the virtual image target Ia formed by the predetermined image.

[0224] On the other hand, the light emitted from the point Pb1 on the light exit surface 24A of the image generating unit 24 enters the optical path 1Lb1 after passing through the lens 28. The focal length of the light emitted from the point Pb1 changes due to passing through the lens 28. That is, the apparent optical path length of the light emitted from the point Pb1 becomes longer due to passing through the lens 28. The light entering the optical path 1Lb1 is reflected at the point 1Pb2 on the plane mirror 126B and enters the optical path 1Lb2, and is emitted to the outside of the HUD 220A from the exit window 23 of the HUD main body 21. The light entering the optical path 1Lb2 passes through the point 1Pb3 incident on the windshield 18, thereby forming a part of the virtual image target 1Ib formed by the predetermined image. The virtual image target 1Ib is formed, for example, at a position separated from the windshield 18 forward by a distance longer than the virtual image target Ib of the fifth embodiment (for example, about 6 to 9 meters). The distance of the virtual image target object Ib (the distance from the windshield 18 to the virtual image) can be appropriately adjusted by adjusting the position of the lens 28.

[0225] As described above, the HUD 220A involved in the sixth embodiment includes a lens 28 disposed on the optical path between the image generating unit 24 and the plane mirror 126B of the reflecting unit 126. The lens 28 is configured to extend the optical path length from the image generating unit 24 to the plane mirror 126B. The virtual image of the first image formed by the first light reflected by the concave mirror 126A is at a longer distance from the position of the driver's eyes than the virtual image of the second image formed by the second light reflected by the plane mirror 126B. Therefore, the difference in the distance of the virtual image from the position of the driver's eyes sometimes gives the driver a sense of disharmony. According to the above-mentioned configuration, by extending the optical path length between the image generating unit 24 and the plane mirror 126B by the lens 28, the distance from the position of the driver's eyes to the virtual image of the second image can be extended. Thus, the driver's sense of disharmony caused by the difference in the distance of the virtual image can be reduced.

[0226] (Seventh Embodiment)

[0227] Fig. 22 This is a schematic diagram of the HUD 220B viewed from the side of the vehicle 1 .

[0228] like Fig. 22As illustrated, the HUD 220B of the seventh embodiment is different from the HUD 220 of the fifth embodiment in which the reflecting portion 126 includes the concave mirror 126A and the flat mirror 126B in that the reflecting portion 226 includes a concave mirror 226A and two flat mirrors 226B and 226C.

[0229] It should be noted that the position of the plane mirror 226C in the front-rear direction of the vehicle 1 is the same as that of the plane mirror 226B. Fig. 22 The optical path, virtual image target, etc. associated with the plane mirror 226C are formed to be the same as those associated with the plane mirror 226B when viewed from the side of the vehicle 1, so they are omitted from the illustration and only the reference numerals are shown in brackets.

[0230] The reflection unit 226 includes a concave mirror 226A, a plane mirror 226B, and a plane mirror 226C. The concave mirror 226A has a concavely curved reflection surface to form a virtual image, and reflects the image of the light emitted from the image generating unit 224 at a predetermined magnification. The plane mirrors 226B and 226C have planar reflection surfaces to form a virtual image, and reflect the image of the light emitted from the image generating unit 224 at the same magnification. Fig.23 In the illustrated example, the concave mirror 226A and the plane mirrors 226B and 226C are arranged side by side in the horizontal direction of the vehicle 1 with the concave mirror 226A sandwiched between the plane mirror 226B and the plane mirror 226C.

[0231] The image generating unit 224 includes a first image area for emitting the first light irradiating the concave mirror 226A, a second image area for emitting the second light irradiating the plane mirror 226B, and a third image area for emitting the third light irradiating the plane mirror 226C. The control unit 225 controls the image generating operations of the first image area, the second image area, and the third image area in the image generating unit 224 so that the first light is irradiated to the concave mirror 226A, the second light is irradiated to the plane mirror 226B, and the third light is irradiated to the plane mirror 226C.

[0232] For example, light (an example of the first light) emitted from point 2Pa1 on the light exit surface 24A of the image generating unit 224 enters the optical path 2La1, is reflected at point 2Pa2 on the concave mirror 226A, enters the optical path 2La2, and is emitted to the outside of the HUD 220B from the exit window 23 of the HUD main body 21. The light entering the optical path 2La2 passes through point 2Pa3 incident on the windshield 18, and forms a part of a virtual image target 2Ia (an example of the first image) formed by a predetermined image. The virtual image target 2Ia is formed at a position separated from the windshield 18 by a relatively long predetermined distance (for example, about 7 to 10 meters) in the forward direction.

[0233] On the other hand, the light (an example of the second light) emitted from the point 2Pb1 on the light exit surface 24A of the image generating unit 224 enters the optical path 2Lb1, is reflected at the point 2Pb2 on the plane mirror 226B, enters the optical path 2Lb2, and is emitted to the outside of the HUD 220B from the exit window 23 of the HUD main body 21. The light entering the optical path 2Lb2 passes through the point 2Pb3 incident on the windshield 18, and forms a part of the virtual image target 2Ib (an example of the second image) formed by the predetermined image. The virtual image target 2Ib is formed at a position separated from the windshield 18 forward by a distance shorter than the virtual image target 2Ia (for example, about 3 to 5 meters).

[0234] The light (an example of the third light) emitted from the point 2Pc1 on the light exit surface 24A of the image generating unit 224 enters the optical path 2Lc1, is reflected at the point 2Pc2 on the plane mirror 226C, enters the optical path 2Lc2, and is emitted to the outside of the HUD 220B from the exit window 23 of the HUD main body 21. The light entering the optical path 2Lc2 passes through the point 2Pc3 incident on the windshield 18, and forms a part of the virtual image target 2Ic (an example of the third image) formed by the predetermined image. The virtual image target 2Ic is formed, for example, at a position separated from the windshield 18 forward by a distance substantially equal to that of the virtual image target 2Ib.

[0235] Fig.24 This is a schematic diagram illustrating an area 360 illuminated by the light emitted from the HUD 220B in the windshield 18 .

[0236] like Fig.24 In the example shown, the first light for generating the first image reflected by the concave mirror 226A is irradiated to the region 360A. The second light for generating the second image reflected by the plane mirror 226B is irradiated to the region 360B located on the left side of the region 360A in the horizontal direction of the windshield 18. The third light for generating the third image reflected by the plane mirror 226C is irradiated to the region 360C located on the right side of the region 360A in the horizontal direction of the windshield 18. As a result, the virtual image target 21a is formed in a state sandwiched between the virtual image target 21b and the virtual image target 21c in the horizontal direction of the vehicle 1.

[0237] As described above, in the HUD 220B involved in the seventh embodiment, the concave mirror 226A, the plane mirror 226B, and the plane mirror 226C are arranged side by side in the horizontal direction of the vehicle 1 with the concave mirror 226A sandwiched between the plane mirror 226B and the plane mirror 226C. As a result, the driver can recognize the virtual image of the first image without almost moving the focus of the eyes while the vehicle is running. As a result, the driver can grasp the information represented by the first image in a moment. In addition, the driver can grasp the virtual image of the second image and the virtual image of the third image only by moving the line of sight left and right while the vehicle is running.

[0238] (Eighth Embodiment)

[0239] Fig.25 This is a schematic diagram of the HUD 220C as viewed from the side of the vehicle 1 .

[0240] like Fig.25 As illustrated, the HUD 220C of the eighth embodiment is different from the HUD 220B of the seventh embodiment in that a lens 80 is disposed between an image generating unit 224 and plane mirrors 226B and 226C.

[0241] The lens 80 is configured to change the focal length of the light emitted from the light emitting surface 24A of the image generating unit 224. The lens 80 is disposed at a position where the light emitted from the light emitting surface 24A of the image generating unit 224 and heading for the plane mirrors 226B and 226C passes. The lens 80 includes a first lens 81 and a second lens 82. The first lens 81 is disposed between the image generating unit 224 and the plane mirror 226B. The second lens 82 is disposed between the image generating unit 224 and the plane mirror 226C. It should be noted that the position of the second lens 82 in the front-rear direction of the vehicle 1 is the same as that of the first lens 81, and therefore Fig.25 It is not displayed due to the overlap with the first lens 81.

[0242] The lens 80 may include, for example, a driving unit, and may be configured to be able to change the distance between the lens 80 and the image generating unit 224 by a control signal generated by the control unit 225. By moving the lens 80, the focal length (apparent optical path length) of the light emitted from the image generating unit 224 changes, and the distance between the windshield 18 and the predetermined image displayed by the HUD 220C changes.

[0243] For example, light emitted from point 3Pa1 on the light exit surface 24A of the image generating unit 224 enters the optical path 3La1, is reflected at point 3Pa2 on the concave mirror 226A, enters the optical path 3La2, and is emitted to the outside of the HUD 220C from the exit window 23 of the HUD main body 21. The light entering the optical path 3La2 passes through point 3Pa3 incident on the windshield 18, and forms a part of a virtual image target 3Ia formed by a predetermined image. The virtual image target 3Ia is formed at a position separated from the windshield 18 by a relatively long predetermined distance (for example, about 7 to 10 meters) in the forward direction.

[0244] On the other hand, the light emitted from the point 3Pb1 on the light exit surface 24A of the image generating unit 224 enters the optical path 3Lb1 after passing through the first lens 81. The focal length of the light emitted from the point 3Pb1 changes due to passing through the first lens 81. That is, the apparent optical path length of the light emitted from the point 3Pb1 becomes longer due to passing through the first lens 81. The light entering the optical path 3Lb1 is reflected at the point 3Pb2 on the plane mirror 226B and enters the optical path 3Lb2, and is emitted to the outside of the HUD 220C from the exit window 23 of the HUD main body 21. The light entering the optical path 3Lb2 passes through the point 3Pb3 entering the windshield 18, and forms a part of the virtual image target 3Ib formed by the predetermined image. The virtual image target 3Ib is formed, for example, at a position separated from the windshield 18 forward by a distance longer than the virtual image target 2Ib of the seventh embodiment (for example, about 6 to 9 meters). The distance of the virtual image target 31b (the distance from the windshield 18 to the virtual image) can be appropriately adjusted by adjusting the position of the first lens 81.

[0245] The light emitted from the point 3Pc1 on the light exit surface 24A of the image generating unit 224 enters the optical path 3Lc1 after passing through the second lens 82. The focal length of the light emitted from the point 3Pc1 changes due to passing through the second lens 82. That is, the apparent optical path length of the light emitted from the point 3Pc1 becomes longer due to passing through the second lens 82. The light entering the optical path 3Lc1 is reflected at the point 3Pc2 on the plane mirror 226C and enters the optical path 3Lc2, and is emitted to the outside of the HUD 220C from the exit window 23 of the HUD main body 21. The light entering the optical path 3Lc2 passes through the point 3Pc incident on the windshield 18, and forms a part of the virtual image target 3Ic formed by the predetermined image. The virtual image target 3Ic is formed, for example, at a position separated from the windshield 18 by a distance (for example, about 6 to 9 meters) in the front direction than the virtual image target 2Ic of the seventh embodiment. The distance of the virtual image target 31c (the distance from the windshield 18 to the virtual image) can be appropriately adjusted by adjusting the position of the second lens 82.

[0246] As described above, the HUD 220C involved in the eighth embodiment includes a first lens 81 disposed on the optical path between the image generating unit 224 and the plane mirror 226B of the reflecting unit 226. In addition, the HUD 220C includes a second lens 82 disposed on the optical path between the image generating unit 224 and the plane mirror 226C of the reflecting unit 226. The first lens 81 is configured to extend the optical path length from the image generating unit 224 to the plane mirror 226B. The second lens 82 is configured to extend the optical path length from the image generating unit 224 to the plane mirror 226C. The virtual image of the first image formed by the first light reflected by the concave mirror 226A is at a longer distance from the position of the driver's eyes than the virtual image of the second image formed by the second light reflected by the plane mirror 226B. The virtual image of the first image formed by the first light reflected by the concave mirror 226A is at a longer distance from the position of the driver's eyes than the virtual image of the third image formed by the third light reflected by the plane mirror 226C. Therefore, sometimes the driver is brought a sense of disharmony due to the difference in the distance of the virtual image at the position of the driver's eyes. According to the above-mentioned configuration, by extending the optical path length between the image generating unit 224 and the plane mirror 226B by the first lens 81, the distance from the position of the driver's eyes to the virtual image of the second image can be extended. In addition, by extending the optical path length between the image generating unit 224 and the plane mirror 226C by the second lens 82, the distance from the position of the driver's eyes to the virtual image of the 3rd image can be extended. Thus, the driver's sense of disharmony caused by the difference in the distance of the virtual image can be reduced.

[0247] (Ninth Embodiment)

[0248] Fig.26 It is a schematic diagram of the HUD 320 viewed from the side of the vehicle 1. It should be noted that in the description of the ninth embodiment, for the convenience of description, the description of the components having the same reference numerals as those already described in the description of the first embodiment will be omitted. Fig.26 As shown, the HUD 320 includes a HUD main body 21. The HUD main body 21 includes a housing 22 and an exit window 23. The HUD main body 21 includes an image generating unit 24, a control unit 25, and a concave mirror 27 (an example of a reflecting unit) inside the housing 22.

[0249] The image generating unit 24 emits light for generating an image from a light emitting surface (display device surface) 124 toward the outside. The light emitting surface 124 of the image generating unit 24 is provided with a first light emitting surface (an example of the first area) 124A and a second light emitting surface (an example of the second area) 124B as an emitting surface other than the first light emitting surface 124A. The first light emitting surface 124A is an emitting surface that emits light for generating a first image that is a part of a predetermined image. The second light emitting surface 124B is an emitting surface that emits light for generating a second image that is a part of a predetermined image and is different from the first image. For the first light emitting surface 124A and the second light emitting surface 124B, Fig.28 This will be described later.

[0250] The concave mirror 27 is arranged on the optical path of the light emitted from the image generating unit 24. The concave mirror 27 is configured to reflect the light emitted from the image generating unit 24 toward the windshield 18 (for example, the front window of the vehicle 1). The concave mirror 27 has a reflective surface curved in a concave shape in order to form a predetermined image, and reflects the image of the light emitted from the image generating unit 24 at a predetermined magnification. The concave mirror 27 may have a driving mechanism (not shown), which is configured to be able to rotate the direction of the concave mirror 27 based on a control signal sent from the control unit 25.

[0251] The light emitted from the light exit surface 124 of the image generating unit 24 is reflected by the concave mirror 27 and emitted from the exit window 23 of the HUD main body 21. The light emitted from the exit window 23 of the HUD main body 21 is irradiated to the windshield 18. A portion of the light irradiated from the exit window 23 to the windshield 18 is reflected toward the viewpoint E of the passenger. As a result, the passenger recognizes the light emitted from the HUD main body 21 as a virtual image (predetermined image) formed at a predetermined distance in front of the windshield 18. In this way, the result of the image displayed by the HUD 20 overlapping with the real space in front of the vehicle 1 through the windshield 18 is that the passenger can visually confirm that the virtual image target I formed by the predetermined image is suspended on the road outside the vehicle.

[0252] However, since the light emitted from the light emitting surface 124 of the image generating unit 24 is reflected by the concave mirror 27, distortion accompanying the reflection by the concave mirror 27 is generated in the virtual image target I recognized by the passenger as a predetermined image. Therefore, in order to enable the passenger to accurately recognize the information of the virtual image target I, it is preferable to perform a correction process on the distortion of the generated virtual image target I, for example.

[0253] Next, refer to Fig.27A , Fig.27B , Fig.28 as well as Fig.29 Distortion generated in a virtual image object and processing for correcting the distortion (correction by image warping) will be described.

[0254] Fig.27A An example of an image generated by light emitted from the image generating unit of the HUD according to the comparative example is shown, that is, an image generated by the previous light reflected by the concave mirror (hereinafter also referred to as an emission surface image) 431 on the light emission surface 424 of the image generating unit. In addition, Fig.27B express Fig.27A The emission surface image 431 shown is reflected by the concave mirror and recognized by the passenger as a predetermined virtual image object X. It should be noted that in the image of this example, information indicating the travel speed (50 km / h) of the vehicle is displayed.

[0255] like Fig.27A As shown, in the case where the light exit surface image 431 in the light exit surface 424 of the image generating unit involved in the comparative example is a normal image, for example, an image to which a predetermined correction process is not applied for the distortion caused by reflection by a concave mirror, as shown in FIG. Fig.27B As shown, the virtual image object X generated by the light reflected by the concave mirror is displayed as an image of a distorted shape. In this example, the virtual image object X is displayed as an image of a shape in which the upper side is elongated and the lower side is shortened.

[0256] In contrast, in the image generating unit 24 of the HUD 320 according to the ninth embodiment, in order to correct the distortion of the image caused by reflection by the concave mirror 27 , an inverse correction process (also referred to as correction process by warping) is applied to the emission surface image in advance.

[0257] Fig.28 An example of emission surface images 331 and 332 generated by light emitted from the image generating unit 24 of the HUD 320 is shown. Fig.29 yes Fig.28 The exit surface images 331 and 332 shown are reflected by the concave mirror 27 and displayed as a virtual image target in front of the vehicle.

[0258] like Fig.28 As shown, the light exit surface 124 of the image generating unit 24 is formed into a rectangle, and is provided with a first light exit surface 124A and a second light exit surface 124B. Moreover, an exit surface image 331 is generated by the light emitted from the first light exit surface 124A, and an exit surface image 332 is generated by the light emitted from the second light exit surface 124B. In the exit surface image 331 of this example, a speed image reporting that the current driving speed is 50 km / h and an attention-raising image (angle bracket pattern) for prompting the attention of passengers are displayed. In addition, in the exit surface image 332, an attention-raising image (angle bracket pattern) for prompting the attention of passengers is displayed.

[0259] The first light exit surface 124A in the rectangular light exit surface 124 is formed as an exit surface in the shape of an annular sector, for example. Fig.29 The maximum display range 351 of the rectangle of the virtual image target object 1a shown in the figure. That is, the first light exit surface 124A is preferably formed to occupy the maximum extended area of ​​the annular sector in the light exit surface 124. The second light exit surface 124B in the rectangular light exit surface 124 is formed to be the exit surface of the area outside the first light exit surface 124A. That is, the second light exit surface 124B will provide Fig.29 The rectangular display range 352 of the virtual image target object 1b shown is formed in an area outside the maximum display range 351 for displaying the virtual image target object 1a. The second light exit surface 124B of this example is formed in an area closer to the inner arc 342 than the outer arc 341 in the annular sector-shaped first light exit surface 124A. Specifically, the second light exit surface 124B is formed on the left and right sides of the lower area with a smaller left and right width in the first light exit surface 124A. In this way, the first light exit surface 124A is formed larger than the second light exit surface 124B in the light exit surface 124.

[0260] In order to correct the distortion caused by the reflection by the concave mirror 27, the output surface image 331 of the first light output surface 124A and the output surface image 332 of the second light output surface 124B are subjected to inverse correction (warping) which is distorted in the opposite direction in advance according to the amount of distortion caused by the reflection by the concave mirror 27. In this example, the output surface images 331 and 332 are subjected to correction for stretching the upper side of the image, and to shrinking the lower side.

[0261] The amount of distortion generated in the virtual image object I due to the reflection by the concave mirror 27 is, for example, Fig.27B It can be seen that the virtual image target X becomes smaller as it approaches the center of the virtual image target I, and becomes larger as it moves away from the center. Therefore, the correction amount of the warping applied to the exit surface images 331 and 332 as the original image of the virtual image target I varies depending on the position of the exit surface images 331 and 332, corresponding to the magnitude of the distortion amount based on the part of the virtual image target I. For example, the correction amount of the exit surface image at the position corresponding to the center of the virtual image target I is relatively small, and the correction amount of the exit surface image at the position corresponding to the part separated from the center is relatively large.

[0262] In this example, the exit surface image 332 of the second light exit surface 124B is displayed in a region close to the inner arc 342 in the first light exit surface 124A which is formed in a larger annular sector at the central portion of the light exit surface 124. The exit surface image 332 is an image displayed in a region separated from the central portion of the light exit surface 124. The exit surface image 331 of the first light exit surface 124A is an image of a position corresponding to the central portion of the virtual image target object I. In addition, the exit surface image 332 of the second light exit surface 124B is an image of a position corresponding to a portion separated from the central portion of the virtual image target object I. Therefore, the image generating unit 24 generates the exit surface images 331 and 332 on the light exit surface 124 in such a manner that the correction coefficient for correcting the distortion caused by the light of the exit surface image 332 constituting the original image of the virtual image target object Ib being reflected by the concave mirror 27 is greater than the correction coefficient for correcting the distortion caused by the light of the exit surface image 331 constituting the original image of the virtual image target object Ia being reflected by the concave mirror 27. That is, when the distortion caused by the virtual image target object I is corrected, the correction amount of the exit surface image 332 displayed on the second light exit surface 124B is greater than the correction amount of the exit surface image 331 (the average correction amount of the entire exit surface image 331).

[0263] As described above, the exit surface images 331 and 332 are subjected to inverse correction processing in advance to be distorted in the opposite direction according to the amount of distortion caused by reflection on the concave mirror 27. Therefore, when the light generating the exit surface images 331 and 332 is reflected by the concave mirror 27, as shown in FIG. Fig.29 As shown, the virtual image object I (Ia, Ib) visually recognized as undistorted. The virtual image object Ia is an image generated by the exit surface image 331 of the first light exit surface 124A. The virtual image object Ib is an image generated by the exit surface image 332 of the second light exit surface 124B.

[0264] The virtual image object 1a and the virtual image object 1b are configured so that the position where the virtual image object 1a is recognized and the position where the virtual image object 1b is recognized are substantially the same in front of the vehicle 1. That is, the distance from the windshield 18 to the virtual image object 1a and the distance from the windshield 18 to the virtual image object 1b are configured to be substantially the same distance.

[0265] The virtual image target 1b is displayed side by side with the virtual image target 1a around the virtual image target 1a. In this example, the virtual image target 1b is displayed on the left and right of the virtual image target 1a when viewed from the passengers of the vehicle 1. The information displayed by the virtual image target 1a and the information displayed by the virtual image target 1b are configured to form mutually related information. As an example, as the virtual image target 1a, speed information (50km / h) reporting the driving speed and attention-calling information (angle bracket pattern) urging attention to the driving speed are displayed. In addition, as the virtual image target 1b, attention-calling information (angle bracket pattern) urging attention to the content of the report of the virtual image target 1a is displayed. Moreover, the angle bracket pattern of the virtual image target 1b is displayed side by side in a manner that becomes an angle bracket pattern continuous to the left or right side of the angle bracket pattern of the virtual image target 1a. The display range of the image visually recognized as the virtual image target I becomes the image range obtained by adding the virtual image target Ia (first image) formed by the light emitted from the first light exit surface 124A and the virtual image target Ib (second image) formed by the light emitted from the second light exit surface 124B.

[0266] As described above, the HUD 320 according to the present embodiment includes the image generating unit 24 that emits light for generating the virtual image target I (predetermined image), and the concave mirror 27 (an example of a reflecting unit) that reflects the light emitted by the image generating unit 24 so as to irradiate the windshield 18. In addition, in the light emitting surface 124 of the image generating unit 24, the area that can form the rectangular maximum display range 351 for displaying the virtual image target Ia (an example of a first image) as a part of the virtual image target I is set as the first light emitting surface 124A (an example of a first area), and the area other than the first light emitting surface 124A is set as the second light emitting surface 124B (an example of a second area), and it is configured that the virtual image target Ib (an example of a second image) different from the virtual image target Ia is displayed by the light emitted from the first light emitting surface 124A. According to this configuration, in the light emitting surface 124 of the image generating unit 24, by providing the second light emitting surface 124B in addition to the first light emitting surface 124A, it is possible to set a display range 352 for displaying the virtual image target object 1b in an area outside the rectangular maximum display range 351 for displaying the virtual image target object 1a. Therefore, compared with the case where the image generating unit only has a single light emitting surface (see Fig.27A ) compared to existing HUDs, it can expand the display range of virtual images.

[0267] In addition, in the HUD 320 involved in the present embodiment, the light exit surface 124 is formed in a rectangular shape, the first light exit surface 124A is formed in an annular sector region in the rectangular light exit surface 124, and the second light exit surface 124B is formed in an area of ​​the light exit surface 124 that is closer to the inner arc than the outer arc of the first light exit surface 124A in the annular sector. According to this configuration, the portion other than the first light exit surface 124A in the annular sector of the rectangular light exit surface 124, specifically, the left and right side portions of the lower area with a smaller left and right width in the first light exit surface 124A in the annular sector, can be efficiently used as the area for forming the second light exit surface 124B. Therefore, it is possible to suppress the large-scale of the high-cost light exit surface 124 and expand the display range of the virtual image (image).

[0268] In the HUD 320 according to the present embodiment, the correction coefficient for correcting the distortion of the virtual image object 1b caused by the reflection of the light constituting the original image (exit surface image 332) of the virtual image object 1b generated by the image generating unit 24 by the concave mirror 27 is larger than the correction coefficient for correcting the distortion of the virtual image object 1a caused by the reflection of the light constituting the original image (exit surface image 331) of the virtual image object 1a generated by the image generating unit 24 by the concave mirror 27. Since the second light exit surface 124B is formed on the outer edge side of the light exit surface 124 of the image generating unit 24 relative to the first light exit surface 124A, it is highly likely that the distortion of the virtual image object 1b caused by the reflection of the virtual image object 1a by the concave mirror 27 becomes larger. Therefore, by making the correction coefficient of the virtual image target Ib displayed on the second light exit surface 124B larger than the correction coefficient of the virtual image target Ia displayed on the first light exit surface 124A, the distortion of the virtual image target Ib having a larger distortion amount can be appropriately corrected.

[0269] In addition, according to the HUD 320, virtual image objects 1b are displayed on the left and right of the virtual image object 1a, and the virtual image objects 1a and 1b can be associated with the content of the information displayed by each image. For example, attention-calling information (angle bracket pattern) displayed as the virtual image object 1a and attention-calling information (angle bracket pattern) displayed as the virtual image object 1b can be displayed in sequence. In this way, various information can be provided to passengers through the cooperation of the virtual image object 1a and the virtual image object 1b.

[0270] It should be noted that in Fig.28 A third light exit surface (not shown) is provided at the upper corners of the left and right parts of the light exit surface 124. The correction coefficient of the third light exit surface is preferably greater than the correction coefficient of the first light exit surface 124A, similarly to the second light exit surface 124B. Fig.29 In this way, by effectively using the area other than the first light exit surface 124A and the second light exit surface 124B of the light exit surface 124 as the third light exit surface, the display range of the virtual image (image) can be further expanded.

[0271] (Variation Example)

[0272] Fig.30 This is a schematic diagram showing the structure of a HUD 320A according to a modification.

[0273] like Fig.30 As shown, the HUD 320A involved in the modified example is composed of a HUD main body 21 and a synthesizer 19. The synthesizer 19 is a structure separate from the windshield 18 and is arranged on the inner side of the windshield 18. The synthesizer 19 is, for example, a transparent plastic plate, which replaces the windshield 18 and is irradiated with light emitted from the light exit surface 124 and reflected by the concave mirror 27. As a result, as in the case of irradiating light to the windshield 18, a part of the light irradiated from the HUD main body 21 to the synthesizer 19 is reflected toward the viewpoint E of the passenger. As a result, the passenger can recognize the emitted light (predetermined image) from the HUD main body 21 as a virtual image target I formed at a predetermined distance in front of the synthesizer 19 (and the windshield 18).

[0274] In the case of the HUD 320A including the synthesizer 19 as described above, the same effects as those of the HUD 20 described above can be exhibited.

[0275] The embodiments of the present disclosure are described above, but the technical scope of the present invention is certainly not interpreted restrictively by the description of the embodiments. The present embodiment is only an example, and those skilled in the art can understand that various embodiments can be changed within the scope of the invention described in the claims. The technical scope of the present invention should be determined based on the scope of the invention described in the claims and its equivalent scope.

[0276] The optical isolator 70 described in the first embodiment can be provided with a light emitting device of a projector configured to display a predetermined image on an object such as an outdoor wall. That is, in the projector, for example, the optical isolator can be arranged at a position where light from the light source passes between the light source and the optical member (lens, etc.) or between the optical member and the image display object. Thus, a projector can be provided that can prevent the occurrence of heat damage caused by external light entering the light source without reducing the light emitting function.

[0277] In the third and fourth embodiments, the case where the first image and the second image (or the first image, the second image, and the third image) are displayed simultaneously is described, but the present invention is not limited thereto. For example, only one image may be displayed depending on the HUD information to be displayed.

[0278] In the third embodiment, the base member 40 of the concave mirror 30 is formed by a single (monolithic) member, but is not limited thereto. For example, the base member may be formed by integrating a plurality of base members corresponding to a plurality of reflection regions with or without gaps. The reflective film 50 may be formed together with respect to a plurality of base members, or may be formed separately for the base members.

[0279] In the modified example of the third embodiment, the concave mirror 130 is formed as a whole by connecting the first base member 141 and the second base member 142 to each other, but the present invention is not limited thereto. For example, the first base member 141 and the second base member 142 may be formed as a whole adjacent to each other with a gap therebetween. In the case where the concave mirror is formed by integrating a plurality of base members with a gap therebetween, the operation of the image generating unit 24 may be controlled so that light is irradiated to the portion corresponding to the gap.

[0280] In the third and fourth embodiments, the reflecting part is a concave mirror 30, 130, 230, but is not limited thereto. For example, the reflecting part may be a plane mirror having a reflecting surface with a plurality of reflecting areas having different surface roughnesses. Thus, the reflecting part can be realized at a low cost without significantly reducing the quality of the virtual image.

[0281] In the third embodiment and the fourth embodiment described above, the concave mirror 30, 130, 230 is composed of a base member 40, 140, 240 and a reflective film 50, 150, 250, but is not limited thereto. For example, a top coating for corrosion prevention may be formed on the reflective film. The top coating is formed of, for example, a transparent resin, and the light emitted from the image generating unit 24 passes through the top coating and is reflected by the reflective film. That is, since the rear surface of the reflective film forms the reflective surface of the concave mirror, the surface roughness of the rear surface of the top coating may also be uniform. The surface roughness of the rear surface of the top coating (the surface irradiated by the light emitted from the image generating unit 24) may be changed by forming the top coating as a thin film so as to be affected by the surface of the reflective film.

[0282] In the third and fourth embodiments, the surface roughness or material of the base members 40, 140, 240 of the concave mirrors 30, 130, 230 is made different, and as a result, the reflection surfaces 31, 131, 231 having different surface roughness are formed, but the present invention is not limited thereto. For example, the reflection surfaces having different surface roughness may be formed by making the base members 40, 140, 240 have the same surface roughness or be formed of the same material, and making the surface roughness or material of the reflection films 50, 150, 250 different.

[0283] In the third and fourth embodiments, the concave mirror 30, 130, 230 is divided into two or three reflection areas along the longitudinal or transverse direction, but the present invention is not limited thereto. The shape of the divided reflection areas can be determined according to the position or area of ​​the windshield 18 that the driver observes most frequently.

[0284] In the third and fourth embodiments, the concave mirror 30 , 130 , 230 reflects the light emitted from the image generating unit 24 toward the windshield 18 , but the present invention is not limited thereto. The concave mirror 30 , 130 , 230 may reflect the light toward a combiner provided inside the windshield 18 .

[0285] In the third and fourth embodiments described above, light including predetermined images forming the first image, the second image, and the third image is emitted via one display device of the image generating unit 24, but the present invention is not limited thereto. The image generating unit 24 may include a first display device that emits light forming the first image, a second display device that emits light forming the second image, and a third display device that emits light forming the third image. In this case, the light source and the optical component are provided to correspond to each display device.

[0286] In the fourth embodiment described above, the case where the light emitted by the HUD 120 is irradiated to the area below the center line C in the windshield 18 is shown, but the present invention is not limited thereto. In the case where the light emitted by the HUD 120 is irradiated to the area above the center line C in the windshield 18, the concave mirror 30 may be formed such that the first reflection area 31A is arranged below the second reflection area 31B. In this case, the first light reflected by the first reflection area 31A is irradiated to the area above the area irradiated by the second light reflected by the second reflection area 31B on the windshield 18.

[0287] In the fifth to eighth embodiments described above, the image generating unit 24 is configured to generate the second image so that its size is larger than that of the first image. In addition, the image generating unit 224 is configured to generate the second image and the third image so that their sizes are larger than that of the first image. The concave mirrors 126A and 226A reflect the first light in a manner that enlarges the first image, and in contrast, the plane mirrors 126B and 226B reflect the second light in a manner that keeps the size of the second image unchanged. In addition, the plane mirrors 126C and 226C also reflect the third light in a manner that keeps the size of the third image unchanged. Therefore, the size of the virtual image of the first image is larger than the size of the virtual image of the second image. In addition, the size of the virtual image of the first image is larger than the size of the virtual image of the third image. The difference in the size of the virtual image sometimes gives the driver a sense of disharmony. According to the above-mentioned configuration, the size of the virtual image of the second image (and the third image) can be enlarged, reducing the driver's sense of disharmony caused by the difference in the size of the virtual image.

[0288] In addition, in the above-mentioned fifth to eighth embodiments, a display device via the image generating unit 24, 224 emits light to form a predetermined image including a first image, a second image, and a third image, but is not limited thereto. The image generating unit 24 may include a first generating unit that generates a first image, and a second generating unit that generates a second image. The image generating unit 224 may include a first generating unit that generates a first image, a second generating unit that generates a second image, and a third generating unit that generates a third image. The light source and the optical component are provided to correspond to each generating unit. In this case, the first image may be a color image, and the second image (and the third image) may be a black and white image. According to this configuration, since the second image is a black and white image, the second generating unit (and the third generating unit) can be realized at a low cost, and as a result, the image generating unit can be realized at a low cost.

[0289] It should be noted that, in the fifth to eighth embodiments described above, the case of simultaneously displaying the first image and the second image (or the first image, the second image, and the third image) is described, but is not limited thereto. For example, only one image may be displayed depending on the HUD information to be displayed.

[0290] In addition, the arrangement direction and number of the concave mirror and the plane mirror constituting the reflection unit are not limited to the vertical or horizontal direction and two or three as in the above-mentioned embodiment.

[0291] In the fifth to eighth embodiments, the reflection units 126 and 226 reflect the light emitted from the image generation units 24 and 224 toward the windshield 18 , but the present invention is not limited thereto. The reflection units 126 and 226 may reflect the light toward a combiner provided inside the windshield 18 .

[0292] In the sixth and eighth embodiments, one or two lenses 28 and 80 are used as the optical element disposed between the image generating unit 24 and 224 and the plane mirrors 126B, 226B and 226C, but the present invention is not limited thereto. As the optical element, a reflector may be used instead of a lens or in addition to a lens. For example, a plurality of plane mirrors may be disposed between the image generating unit 24 and 224 and the plane mirrors 126B, 226B and 226C.

[0293] In the first to ninth embodiments, the driving modes of the vehicle are described as including a fully automatic driving mode, a highly-assisted driving mode, a driving assistance mode, and a manual driving mode, but the driving modes of the vehicle are not limited to the above four modes. The driving mode of the vehicle may include at least one of the four modes. For example, the driving mode of the vehicle may be capable of executing only any one of the four modes.

[0294] Furthermore, the distinction and display of the vehicle's driving modes can be appropriately changed according to the laws or regulations related to autonomous driving in each country. Similarly, the definitions of "full autonomous driving mode", "high driving assistance mode" and "driving assistance mode" described in the descriptions of the first to ninth embodiments are only examples, and these definitions can be appropriately changed according to the laws or regulations related to autonomous driving in each country.

[0295] This application is based on Japanese Patent Application No. 2019-179484 filed on September 30, 2019, Japanese Patent Application No. 2019-197510 filed on October 30, 2019, Japanese Patent Application No. 2019-197511 filed on October 30, 2019, and Japanese Patent Application No. 2019-211328 filed on November 22, 2019, the contents of which are incorporated herein by reference.

Claims

1. A vehicle lamp, which is installed in a vehicle and has a light emitting device, wherein: The light emitting device comprises: light source; an optical member that transmits or reflects the light emitted from the light source to expand the light and irradiate the light to the outside; and an optical isolator that allows the light to pass through but prevents external light from the outside from entering the light source, The optical component includes a concave mirror, The light emitting device is configured to emit light toward the surroundings of the vehicle. The optical isolator is disposed at a position between the optical member and the outer lens of the vehicle lamp through which the light passes.

2. The vehicle lamp according to claim 1, wherein: The optical isolator has: a first polarizer, which polarizes the light in a first direction; A Faraday element, which, under the Faraday effect generated by the application of a magnetic field, causes the light polarized by the first polarizer to pass through while rotating at a predetermined rotation angle from the first direction and to be emitted in a second direction; as well as a second polarizer that transmits the light along the second direction, The Faraday element transmits the external light polarized in the second direction by the second polarizer while rotating it at the predetermined rotation angle, and then emits the external light in a third direction different from the first direction and the second direction.

3. The vehicle lamp according to claim 2, wherein: The Faraday element includes a base layer, a Faraday layer disposed on the base layer, and a protective layer disposed on the Faraday layer.

4. The vehicle lamp according to claim 2 or 3, wherein: At least a portion of the Faraday element is covered by a frame body made of a magnetic body.

5. The vehicle lamp according to claim 2 or 3, wherein: At least one of the first polarizer and the second polarizer includes a filter for shielding at least one of ultraviolet rays and infrared rays.

Images