JP7585312B2 - Image generating device and head-up display - Google Patents

Description

The present disclosure relates to an image generating device and a head-up display equipped with the image generating device.

In the future autonomous driving society, it is expected that visual communication between vehicles and humans will become increasingly important. For example, it is expected that visual communication between a vehicle and its occupants will become increasingly important. In this regard, visual communication between a vehicle and its occupants can be realized using a head-up display (HUD). A head-up display can realize so-called AR (Augmented Reality) by projecting an image or video onto a windshield or combiner, and allowing the occupant to view the image by superimposing it on real space through the windshield or combiner.

Patent document 1 discloses an illumination device used for transmitting illumination of a liquid crystal display device as a head-up display. The illumination device includes a plurality of light sources and a polarization conversion element. The polarization conversion element includes a light-transmitting member that transmits light, a polarization separation film that transmits p-polarized light and reflects s-polarized light of the light incident on the light-transmitting member, and a reflecting portion that reflects the p-polarized light that has transmitted through the polarization separation film.

Patent document 2 discloses a head-up display in which a predetermined virtual image is displayed within an area in which the virtual image can be displayed by transmitting or blocking light using a liquid crystal display device.

Japanese Patent Application Publication No. 2018-4673 Japanese Patent Application Publication No. 2019-207263

However, there is room for improvement in preventing glare in lighting devices such as those described in Patent Document 1.

In addition, light leaking from the liquid crystal display device may cause areas within the virtual image display area other than the virtual image to appear faintly illuminated. In particular, when the external light around the vehicle is weak, the brightness of the virtual image display area becomes higher than the brightness of the surroundings, and the outline of the virtual image display area becomes conspicuous, which may cause discomfort to vehicle occupants and distract them.

One of the objectives of the present disclosure is to provide an image generating device capable of preventing the occurrence of glare, and a head-up display equipped with such an image generating device.

One of the objectives of the present disclosure is to provide an image generating device capable of making the contours of an area in which a virtual image can be displayed less noticeable, and a head-up display equipped with such an image generating device.

An image generating apparatus according to one aspect of the present disclosure includes:
An image generating device that generates an image for a head-up display,
At least one light source;
a substrate on which the at least one light source is mounted;
a lens that transmits light emitted from the at least one light source;
a display device that forms light for generating the image using light transmitted through the lens;
the lens has an entrance portion having an entrance surface into which the light from the at least one light source is incident and a flange portion provided continuously with the entrance surface, an exit surface from which the light is emitted, and a standing wall surface that connects the entrance portion and the exit surface and has a shape that expands outward from the center of the lens as it moves from the exit surface to the entrance portion,
A light blocking portion is provided around at least a portion of the periphery of the display device to block the light that is internally reflected by the standing wall surface.

According to the image generating device having the above configuration, the light emitted from the light source and internally reflected by the vertical wall surface is blocked by the light blocking portion and does not enter the display device. This makes it possible to suppress glare caused by the light reflected by the vertical wall surface becoming stray light.

A head-up display according to one aspect of the present disclosure includes:
The image generating device;
At least one reflecting unit that reflects the light emitted by the image generating device so that the light is irradiated onto a windshield or a combiner;
It is equipped with:

A head-up display having the above configuration can prevent the occurrence of glare.

An image generating apparatus according to one aspect of the present disclosure includes:
An image generating device that generates an image for a head-up display,
A light source;
a lens that transmits light emitted from the light source;
a liquid crystal device that forms light for generating the image using light transmitted through the lens;
The lens has an incident surface through which light from the light source enters and an exit surface through which light that has passed through the lens exits, and a light diffusion treatment is applied to at least a portion of the outer periphery of at least one of the incident surface and the exit surface.

According to the image generating device described above, the light that reaches the outer periphery of the area in which an image can be formed on the liquid crystal device can be reduced by the light diffusion treatment applied to the lens. As a result, even if areas other than the virtual image are faintly illuminated within the area in which a virtual image can be displayed by the head-up display, the brightness of the outer periphery of the area in which a virtual image can be displayed is low, so the outline of the area in which a virtual image can be displayed can be made less noticeable. Note that the "outer periphery" of the area in which a virtual image can be displayed or an image can be formed does not mean the part outside the area, but a part of the area near the boundary of the area.

A head-up display according to one aspect of the present disclosure includes:
The image generating device;
and at least one reflecting portion that reflects the light emitted by the image generating device so that the light is irradiated onto a windshield or a combiner.

According to the above-mentioned head-up display, even if areas other than the virtual image are faintly illuminated within the virtual image displayable area that can be displayed by the head-up display, the brightness of the outer periphery of the virtual image displayable area is low, so that the outline of the virtual image displayable area can be made inconspicuous.

The present disclosure provides an image generating device capable of preventing the occurrence of glare, and a head-up display equipped with the image generating device.

The present disclosure provides an image generating device capable of making the contours of an area in which a virtual image can be displayed less noticeable, and a head-up display equipped with the image generating device.

1 is a block diagram of a vehicle system equipped with a head-up display (HUD) according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing the configuration of a HUD. 1 is a perspective view showing a configuration of an image generating device according to a first embodiment. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 4 is a perspective view showing a lens holder of the image generating device of FIG. 3 . 6 is a cross-sectional view taken along line VI-VI in FIG. FIG. 11 is a cross-sectional view of the image generating device in a state where a light blocking portion is not provided. FIG. 11 is a cross-sectional view showing a configuration of an image generating device according to a second embodiment. FIG. 9 is a perspective view showing a lens of the image generating device shown in FIG. 8 . FIG. 11 is a cross-sectional view showing a configuration of an image generating device according to a third embodiment. FIG. 11 is a perspective view showing a lens of the image generating device shown in FIG. 10 . FIG. 13 is a cross-sectional view showing a configuration of an image generating device according to a fourth embodiment. FIG. 13 is a perspective view showing a lens holder of the image generating device shown in FIG. 12 . FIG. 13 is a schematic diagram showing another configuration of the HUD. FIG. 13 is a schematic cross-sectional view taken in the left-right direction, illustrating the configuration of an image generating device according to a fifth embodiment. FIG. 2 is a schematic cross-sectional view in the front-rear direction showing the configuration of the image generating device. FIG. 2 is a diagram showing an example of a visual field area of a vehicle occupant; FIG. 2 is a plan view of a lens of the image generating device as viewed from the liquid crystal device side. FIG. 2 is a diagram illustrating the traveling direction of light emitted from a light source. FIG. 2 is a diagram illustrating the traveling direction of light emitted from a light source. FIG. 13 is a schematic cross-sectional view taken in the left-right direction, illustrating the configuration of an image generating device according to a sixth embodiment. FIG. 2 is a schematic cross-sectional view in the front-rear direction showing the configuration of the image generating device. FIG. 2 is a rear view of the lens of the image generating device as viewed from the light source side. FIG. 13 is a schematic cross-sectional view taken in the left-right direction, illustrating the configuration of an image generating device according to a seventh embodiment. FIG. 13 is a schematic cross-sectional view taken in the left-right direction, illustrating the configuration of an image generating device according to an eighth embodiment.

Hereinafter, an embodiment of the present disclosure (hereinafter, referred to as the present embodiment) will be described with reference to the drawings. For the sake of convenience, the dimensions of each component shown in the drawings may differ from the actual dimensions of each component.

In addition, in the description of this embodiment, for convenience of explanation, the "left-right direction," "up-down direction," and "front-rear direction" may be referred to as appropriate. These directions are relative directions set for the HUD (Head-Up Display) 20 shown in FIG. 2. Here, the "left-right direction" is a direction that includes the "left direction" and the "right direction." The "up-down direction" is a direction that includes the "upward direction" and the "downward direction." The "front-rear direction" is a direction that includes the "forward direction" and the "rearward direction." Although the left-right direction is not shown in FIG. 2, it is a direction that is perpendicular to the up-down direction and the front-rear direction.

A vehicle system 2 including a HUD 20 according to this embodiment will be described below with reference to FIG. 1. FIG. 1 is a block diagram of the vehicle system 2. A vehicle 1 equipped with the vehicle system 2 is a vehicle (automobile) capable of running in an autonomous driving mode.

1, 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. The vehicle system 2 also includes a steering actuator 12, a steering device 13, a brake actuator 14, a brake device 15, an accelerator actuator 16, and an accelerator device 17. The vehicle system 2 also includes a HUD 20.

The vehicle control unit 3 is configured to control the running of the vehicle 1. The vehicle control unit 3 is configured, for example, by at least one electronic control unit (ECU: Electronic Control Unit). The electronic control unit includes a computer system (e.g., SoC (System on a Chip) etc.) having one or more processors and memories, and an electronic circuit configured 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 may be configured by multiple CPU cores. The GPU may be configured by multiple GPU cores. The memory includes a ROM (Read Only Memory) and a RAM (Random Access Memory). A vehicle control program may be stored in the ROM. For example, the vehicle control program may include an artificial intelligence (AI) program for autonomous driving. The AI program is a program (trained model) constructed by supervised or unsupervised machine learning (particularly, deep learning) using a multi-layer neural network. The RAM may temporarily store the vehicle control program, vehicle control data, and/or surrounding environment information indicating the surrounding environment of the vehicle 1. The processor may be configured to expand a program designated from various vehicle control programs stored in the ROM onto the RAM and execute various processes in cooperation with the RAM. The computer system may also be configured with a non-von Neumann type computer such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). Furthermore, the computer system may be configured with a combination of a von Neumann type computer and a non-von Neumann type computer.

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 driving state information to the vehicle control unit 3. The sensor 5 may further include a seating sensor that detects whether the driver is sitting in the driver's seat, a face direction sensor that detects the direction of the driver's face, an external weather sensor that detects the external weather conditions, and a human presence sensor that detects whether a person is inside the vehicle.

The camera 6 is a camera including an imaging element such as a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS), etc. The camera 6 includes one or more external cameras 6A and an internal camera 6B.
The external camera 6A is configured to obtain image data showing the surrounding environment of the vehicle 1 and transmit the image data to the vehicle control unit 3. The vehicle control unit 3 obtains surrounding environment information based on the transmitted image data. Here, the surrounding environment information may include information on objects (pedestrians, other vehicles, signs, etc.) present outside the vehicle 1. For example, the surrounding environment information may include information on attributes of objects present outside the vehicle 1 and information on the distance and position of the objects relative to the vehicle 1. The external camera 6A may be configured as a monocular camera or as a stereo camera.

The internal camera 6B is disposed inside the vehicle 1 and configured to acquire image data showing the occupant. The internal camera 6B functions, for example, as an eye tracking camera that tracks the occupant's viewpoint E (described later in FIG. 2). The internal camera 6B is provided, for example, near the rearview mirror or inside the instrument panel.

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 acquire 3D mapping data (point cloud data) indicating the surrounding environment of the vehicle 1, and then transmit the 3D mapping data to the vehicle control unit 3. The vehicle control unit 3 identifies surrounding environment information based on the transmitted 3D mapping data.

The HMI 8 is composed of an input unit that accepts input operations from the driver, and an output unit that outputs driving information, etc. to the driver. The input unit includes a steering wheel, an accelerator pedal, a brake pedal, a driving mode changeover 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.

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

The wireless communication unit 10 is configured to receive information (e.g., driving information, etc.) about other vehicles around the vehicle 1 from the other vehicles and transmit information (e.g., driving information, etc.) about the vehicle 1 to the other vehicles (vehicle-to-vehicle communication). The wireless communication unit 10 is also configured to receive infrastructure information from infrastructure equipment such as traffic lights and marker lights and transmit driving information of the vehicle 1 to the infrastructure equipment (road-to-vehicle communication). The wireless communication unit 10 is also configured to receive information about pedestrians from portable electronic devices (smartphones, tablets, wearable devices, etc.) carried by pedestrians and transmit vehicle driving information of the vehicle 1 to the portable electronic device (pedestrian-to-vehicle communication). The vehicle 1 may directly communicate with other vehicles, infrastructure equipment, or portable electronic devices in an ad-hoc mode, or may communicate via an access point. Furthermore, the vehicle 1 may communicate with other vehicles, infrastructure equipment, or portable electronic devices via a communication network not shown. 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. The vehicle 1 may also communicate with other vehicles, infrastructure facilities, or portable electronic devices using a fifth generation mobile communication system (5G).

The storage device 11 is an external storage device such as a hard disk drive (HDD) or a solid state drive (SSD). Two-dimensional or three-dimensional map information and/or a vehicle control program may be stored in the storage device 11. For example, the 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 device 3 in response to a request from the vehicle control device 3. The map information and the vehicle control program may be updated via the wireless communication unit 10 and a communication network.

When the vehicle 1 runs in the autonomous driving mode, the vehicle control unit 3 automatically generates at least one of a steering control signal, an accelerator control signal, and a brake control signal based on the driving state information, the surrounding environment information, the current position information, the map information, etc. The steering actuator 12 is configured to receive a steering control signal from the vehicle control unit 3 and control the 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 the brake device 15 based on the received brake control signal. The accelerator actuator 16 is configured to receive an accelerator control signal from the vehicle control unit 3 and control the accelerator device 17 based on the received accelerator control signal. In this way, the vehicle control unit 3 automatically controls the running of the vehicle 1 based on the driving state information, the surrounding environment information, the current position information, the map information, etc. In other words, in the autonomous driving mode, the running of the vehicle 1 is automatically controlled by the vehicle system 2.

On the other hand, when the vehicle 1 runs in the manual driving mode, the vehicle control unit 3 generates a steering control signal, an accelerator control signal, and a brake control signal in accordance with the driver's manual operation of the accelerator pedal, the brake pedal, and the steering wheel. In this way, in the manual driving mode, the steering control signal, the accelerator control signal, and the brake control signal are generated by the driver's manual operation, so that the running of the vehicle 1 is controlled by the driver.

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, an advanced driving assistance mode, and a driving assistance mode. In the fully automatic driving mode, the vehicle system 2 automatically performs all driving control, including steering control, braking control, and accelerator control, and the driver is not in a state where he can drive the vehicle 1. In the advanced driving assistance mode, the vehicle system 2 automatically performs all driving control, including steering control, braking control, and accelerator control, and the driver is in a state where he can drive the vehicle 1 but does not drive the vehicle 1. In the driving assistance mode, the vehicle system 2 automatically performs some driving control, including steering control, braking control, and accelerator control, and the driver drives the vehicle 1 under 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.

The HUD 20 is configured to display predetermined information (hereinafter referred to as HUD information) as an image toward the occupant of the vehicle 1 so that the HUD information is superimposed on 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 present outside the vehicle 1). The HUD 20 is an AR display that functions as a visual interface between the vehicle 1 and the occupant.

The HUD 20 includes a picture generation unit (PGU) 24 and a control unit 25 .
The image generating device 24 is configured to emit light for generating a predetermined image to be displayed toward an occupant of the vehicle 1. The image generating device 24 can emit light for generating a changing image that changes depending on the situation of the vehicle 1, for example.

The control unit 25 controls the operation of each part of the HUD 20. The control unit 25 is connected to the vehicle control unit 3, and generates a control signal for controlling the operation of the image generation device 24 based on, for example, vehicle driving information and surrounding environment information transmitted from the vehicle control unit 3, and transmits the generated control signal to the image generation device 24. The control unit 25 is equipped with a processor such as a CPU and a memory, and the processor executes a computer program read from the memory to control the operation of the image generation device 24, etc. In this embodiment, the vehicle control unit 3 and the control unit 25 are provided as separate configurations, but the vehicle control unit 3 and the control unit 25 may be configured as an integrated unit. For example, the vehicle control unit 3 and the control unit 25 may be configured as a single electronic control unit.

Figure 2 is a schematic diagram of the HUD 20 viewed from the side of the vehicle 1. At least a portion of the HUD 20 is located inside the vehicle 1. Specifically, the HUD 20 is installed in a predetermined location inside the vehicle 1. For example, the HUD 20 may be disposed in the dashboard of the vehicle 1.

2, the HUD 20 includes a HUD main body 21. The HUD main body 21 has a main body housing 22 and an exit window 23. The exit window 23 is made of a transparent plate that transmits visible light. The HUD main body 21 has an image generating device 24, a concave mirror 26 (an example of a reflecting section), and a plane mirror 28 inside the main body housing 22. Note that in FIG. 2, the control unit 25 of the HUD 20 is housed within the image generating device 24, but as shown in FIG. 14, the control unit 25 may be disposed outside the image generating device 24.

The image generating device 24 is installed in the main housing 22 so as to emit light upward. The plane mirror 28 is disposed on the optical path of the light emitted from the image generating device 24. Specifically, the plane mirror 28 is disposed above the image generating device 24 and configured to reflect the light emitted from the image generating device 24 toward the concave mirror 26.

The concave mirror 26 is disposed on the optical path of the light emitted from the image generating device 24 and reflected by the plane mirror 28. Specifically, the concave mirror 26 is disposed in front of the image generating device 24 and the plane mirror 28 in the main housing 22. The concave mirror 26 is configured to reflect the light emitted from the image generating device 24 toward the windshield 18 (e.g., the front window of the vehicle 1). The concave mirror 26 has a reflective surface that is concavely curved to form a predetermined image, and reflects the image of the light emitted from the image generating device 24 and focused at a predetermined magnification. The concave mirror 26 may have, for example, a drive mechanism 27, and may be configured to change the position and orientation of the concave mirror 26 based on a control signal transmitted from the control unit 25.

The light emitted from the image generating device 24 is reflected by the plane mirror 28 and the concave mirror 26 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 onto the windshield 18. A portion of the light irradiated from the exit window 23 to the windshield 18 is reflected toward the occupant's viewpoint E. As a result, the occupant 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 image displayed by the HUD 20 is superimposed on the real space in front of the vehicle 1 through the windshield 18, and as a result, the occupant can visually recognize the virtual image object I formed by the predetermined image as floating above the road located outside the vehicle.

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

When forming a 2D image (planar image) as the virtual image object I, a predetermined image is projected so as to become a virtual image at a single distance determined arbitrarily. When forming a 3D image (stereoscopic image) as the virtual image object I, a plurality of predetermined images, which may be the same or different from one another, are projected so as to become virtual images at different distances. In addition, the distance of the virtual image object I (the distance from the occupant's viewpoint E to the virtual image) can be appropriately adjusted by adjusting the distance from the image generating device 24 to the occupant's viewpoint E (for example, by adjusting the distance between the image generating device 24 and the concave mirror 26).

First Embodiment
An image generating device 24A according to the first embodiment will be described with reference to FIGS.
Fig. 3 is a perspective view of the image generating device 24A, and Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3.

3 and 4, the image generating device 24A includes a light source board 110 on which a light source 111 (first light source 111A, second light source 111B) is mounted, a lens 120 arranged above the light source 111, and a display device 130 arranged above the lens 120. The image generating device 24A further includes a lens holder 140 arranged above the light source board 110, a heat sink 150 arranged below the light source board 110, and a PGU housing 160 that houses each part of the image generating device 24A. The light source board 110, the lens 120, the lens holder 140, and the heat sink 150 are screwed to the PGU housing 160 by, for example, screws 161. The display device 130 is attached to the upper surface of the PGU housing 160.

The light source 111 (first light source 111A, second light source 111B) 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 light, green laser light, and blue laser light, respectively. The first light source 111A and the second light source 111B are arranged on the light source substrate 110 at a certain distance in the left-right direction. The light source substrate 110 is, for example, a printed circuit board made of an insulator with electrical circuit wiring printed on the surface or inside of the board.

The lens 120 is, for example, an aspheric convex lens in which both the entrance surface 122, where the light from the light source 111 is incident, and the exit surface 123, where the incident light is exited, are formed in a convex shape. The lens 120 is configured to transmit or reflect the light emitted from the light source 111 and emit it toward the display device 130.

The lens 120 in the first embodiment has a first region 121A that transmits the first light emitted from the first light source 111A and a second region 121B that transmits the second light emitted from the second light source 111B. The first light source 111A and the second light source 111B are arranged in parallel in the left-right direction. The first region 121A is an aspheric convex lens corresponding to the first light source 111A. The second region 121B is an aspheric convex lens corresponding to the second light source 111B. The entrance surface 122A of the first region 121A and the entrance surface 122B of the second region 121B are convex entrance surfaces that bulge slightly downward. The exit surface 123A of the first region 121A and the exit surface 123B of the second region 121B are convex exit surfaces that bulge upward. A part of the right side of the first region 121A arranged on the left side and a part of the left side of the second region 121B arranged on the right side are combined. The lens 120 is attached to the lens holder 140 so that the center of the light emitting surface of the first light source 111A is the focal position of the first region 121A and the center of the light emitting surface of the second light source 111B is the focal position of the second region 121B.

The display device 130 is a liquid crystal display, a DMD (Digital Mirror Device), or the like. The display device 130 forms light for generating a predetermined image by the light of the light source 111 transmitted through the lens 120. The display device 130 is attached to the upper surface of the PGU housing 160 with the light emission surface for emitting light for generating an image facing upward of the image generating device 24A. The display device 130 is attached to the PGU housing 160, for example, from the upper side of the PGU housing 160. The drawing method of the image generating device 24A may be a raster scan method, a DLP method, or an LCOS method. When the DLP method or the LCOS method is adopted, the light source 111 of the image generating device 24A may be an LED light source. Note that when the liquid crystal display method is adopted, the light source 111 of the image generating device 24A may be a white LED light source.

The lens holder 140 holds the lens 120 in the PGU housing 160 so that the light emitted from the light source 111 is correctly incident on the incident surface 122 of the lens 120. The detailed configuration of the lens holder 140 will be described later with reference to FIG. 5.

The heat sink 150 is made of a material with high thermal conductivity, such as aluminum or copper. The heat sink 150 is provided in contact with the rear surface of the light source substrate 110 in order to dissipate heat generated from the light source substrate 110.

5 is a perspective view of the lens holder 140 as viewed from the lens 120 side. As shown in FIG. 5, the lens holder 140 has a pair of mounting portions 141 in which mounting holes 142 for screws 161 are formed, and a frame portion 143 provided between the pair of mounting portions 141. The frame portion 143 is provided with a light shielding portion 144 capable of blocking light emitted from the light source 111. The light shielding portion 144 is provided in the center of the lens holder 140 in the left-right direction so as to connect the front frame portion 143A and the rear frame portion 143B along the front-rear direction of the lens holder 140. The light shielding portion 144 is formed integrally with the lens holder 140.

The light shielding portion 144 has a rectangular shape in a cross-sectional view (see FIG. 4). The light shielding portion 144 is provided so as to be disposed between the first light source 111A and the second light source 111B in the space 170 formed between the first light source 111A and the second light source 111B and the lens 120. The light shielding portion 144 can prevent the first light emitted from the first light source 111A from passing through the second region 121B of the lens 120, and can prevent the second light emitted from the second light source 111B from passing through the first region 121A of the lens 120. It is preferable that the surface of the light shielding portion 144 is painted black, for example, so that the light irradiated from each light source 111A and 111B can be absorbed without being reflected.

Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 3. Fig. 6 shows a cross-sectional view along the front-rear and up-down directions of a first region 121A in lens 120. Note that the cross-sectional view of second region 121B of lens 120 has a similar configuration to the cross-sectional view of first region 121A shown in Fig. 6, and therefore detailed description and illustration will be omitted.
6, the first region 121A of the lens 120 includes an incident portion 127A including an incident surface 122A and a flange portion 126A that is provided so as to be continuous with the incident surface 122A on the outer periphery of the incident surface 122A. An outer surface 126A1 of the flange portion 126A is in contact with an inner surface 145 of the lens holder 140.

The first region 121A further includes a vertical wall surface 124A that connects the incident portion 127A and the exit surface 123A. In the example of the lens 120 of the first embodiment, the vertical wall surface 124A is formed on the upper and lower outer peripheries of the lens 120. The vertical wall surface 124A is formed so as to have a shape that spreads outward from the center of the lens 120 as it moves from the exit surface 123A to the incident portion 127A. In other words, the vertical wall surface 124A is formed at an incline with respect to the direction VD (direction along the center line of the lens) perpendicular to the surface of the light source substrate 110 on which the first light source 111A is mounted. The inclination angle θ of the vertical wall surface 124A is set to be 5 degrees or more, preferably 15 degrees or more. If the inclination angle θ is less than 5 degrees, it becomes difficult to remove the lens 120 from the mold when the lens 120 is molded.

At least a part of the periphery of the display device 130 is provided with a light shielding portion 165 that blocks light emitted from the first light source 111A and reflected internally by the vertical wall surface 124A. In the first embodiment, a part of the PGU housing 160 that holds the display device 130 functions as the light shielding portion 165. The PGU housing 160 is formed of, for example, a black resin so as to be able to block light emitted from the first light source 111A. For example, as shown in the optical path 112, the light emitted from the first light source 111A is reflected by the vertical wall surface 124A after entering the lens 120 from the entrance surface 122A of the lens 120. The light reflected by the vertical wall surface 124A is emitted from the exit surface 123A and then irradiated toward the light shielding portion 165 of the PGU housing 160 without entering the display device 130.

FIG. 7 is a diagram showing the optical paths of light emitted from a first light source 111A and a second light source 111B in an image generating device 24Z in which a light blocking portion 144 is not provided on a lens holder 140. As shown in FIG.
The light emitted from the first light source 111A and the second light source 111B is incident on the incidence surfaces 122A and 122B of the lens 120. The shape of the lens 120 is a shape in which two aspheric convex lenses are connected in parallel, similar to the image generating device 24A described above, so that most of the light emitted from the first light source 111A is incident on the first region 121A of the lens 120 as shown in, for example, a first optical path 112A, and becomes light parallel to the optical axis 115A and enters the display device 130. Similarly, most of the light emitted from the second light source 111B is incident on the second region 121B as shown in, for example, a second optical path 112B, and becomes light parallel to the optical axis 115B and enters the display device 130.

However, since the image generating device 24Z does not have a light shielding portion 144, a portion of the light emitted from the first light source 111A enters the second region 121B from the incident surface 122B, as shown in, for example, the third optical path 112C. The light that enters the incident surface 122B from the first light source 111A travels in a direction different from the direction of the optical axis 115A and enters the display device 130, as shown in the third optical path 112C. Similarly, although not shown, the light emitted from the second light source 111B that enters the incident surface 122A of the first region 121A travels in a direction different from the direction of the optical axis 115B and enters the display device 130. In this way, light that is incident from the first light source 111A to the incident surface 122B of the second region 121B, or from the second light source 111B to the incident surface 122A of the first region 121A, enters the display device 130 as light that is not parallel to the optical axes 115A, 115B, and may cause glare for the driver of the vehicle 1.

In contrast, the image generating device 24A according to the first embodiment includes a first light source 111A, a second light source 111B arranged at a certain distance from the first light source 111A, a lens 120 that transmits light emitted from the first light source 111A and the second light source 111B, a display device 130 that forms light for generating an image using the light transmitted through the lens 120, and a lens holder 140 that holds the lens 120. The lens 120 is composed of a first region 121A that transmits light emitted from the first light source 111A (an example of first light), and a second region 121B that is connected in parallel to the first region 121A and transmits light emitted from the second light source 111B (an example of second light). The lens holder 140 is provided with a light shielding portion 144 that is disposed between the first light source 111A and the second light source 111B in the space 170 between the first light source 111A and the second light source 111B and prevents the light emitted from the first light source 111A from passing through the second region 121B and prevents the light emitted from the second light source 111B from passing through the first region 121A. With this configuration, it is possible to suppress glare that may occur when the light from the first light source 111A enters the lens 120 from the incident surface 122B and passes through the second region 121B, or when the light from the second light source 111B enters the lens 120 from the incident surface 122A and passes through the first region 121A. In addition, since the light shielding portion 144 is provided in the lens holder 140, the number of parts can be reduced compared to when the light shielding portion 144 is provided separately from the lens holder 140. This allows the image generating device 24A to be manufactured at low cost.

In addition, according to the image generating device 24A, the first region 121A and the second region 121B of the lens 120 are aspheric lenses in which the entrance surfaces 122A, 122B and the exit surfaces 123A, 123B are all formed as convex surfaces. Therefore, the light emitted from the first light source 111A and the light emitted from the second light source 111B can be aberration-corrected by the lens 120 and made incident on the display device 130 as parallel light. This can improve the generation accuracy of the virtual image object I.

In the image generating device 24A, the lens 120 has an entrance section 127A having an entrance surface 122A on which light from the light source 111A is incident and a flange portion 126A provided continuously with the entrance surface 122A, an exit surface 123A from which the light is emitted, and a standing wall surface 124A which is a portion connecting the entrance section 127A and the exit surface 123A and has a shape that spreads outward from the center of the lens 120 as it moves from the exit surface 123A toward the entrance section 127A. At least a part of the periphery of the display device 130 is provided with a light shielding portion 165 that shields light internally reflected by the standing wall surface 124A. For example, if the standing wall surface 124A is not provided on the lens 120 in FIG. 6, the light emitted from the light source 111A and internally reflected by the lens 120 may become stray light and enter the display device 130. In contrast, in the case where the lens 120 is provided with the vertical wall surface 124A inclined outward from the emission surface 123A toward the incidence portion 127A as in the present embodiment, the light emitted from the light source 111A and internally reflected by the vertical wall surface 124A is irradiated to the light-shielding portion 165 and is blocked by the light-shielding portion 165. Therefore, the light internally reflected by the vertical wall surface 124A does not enter the display device 130. This makes it possible to suppress glare caused by the light reflected by the vertical wall surface 124A becoming stray light and entering the display device 130.

The vertical wall surface 124A rises only from a portion of the outer periphery of the entrance portion 127A. That is, the vertical wall surface 124A is provided on the outer periphery of the lens 120 in the front-to-rear direction, but is not provided on the outer periphery of the lens 120 in the left-to-right direction, as shown in FIG. 4. This makes it possible to suppress the occurrence of glare while maintaining the size of the effective surface of the lens 120.

In addition, by setting the inclination angle θ of the vertical wall surface 124A to 5 degrees or more, it is possible to suppress the occurrence of glare while ensuring the draft angle of the mold for lens molding. Furthermore, by setting the inclination angle θ of the vertical wall surface 124A to 15 degrees or more, it is possible to further reliably suppress the occurrence of glare.

In addition, according to the image generating device 24A, at least a portion of the PGU housing 160 is configured to function as the light shielding portion 165. This allows the light shielding portion 165 to be provided with a simple configuration and also suppresses the occurrence of glare.

Second Embodiment
Next, an image generating device 24B according to a second embodiment will be described with reference to Fig. 8 and Fig. 9. Members with the same reference numerals as those in the image generating device 24A according to the first embodiment have the same configuration as the image generating device 24A, and therefore their description will be omitted. Fig. 8 is a cross-sectional view of the image generating device 24B. Fig. 9 is a perspective view of a lens 220 provided in the image generating device 24B, as viewed from the light sources 111A and 111B side.

8 and 9, the entrance surface 222 of the lens 220 of the image generating device 24B is provided with a light shielding portion 225 capable of blocking light emitted from the light sources 111A and 111B. The lens 220 is provided on both the left and right sides with mounting portions 226 having mounting holes 227 for the screws 161.

The light shielding portion 225 is formed by applying a textured surface to the incident surface 222. The textured surface of the light shielding portion 225 is provided in a strip shape in the center of the lens 220 in the left-right direction, that is, in a predetermined area between the incident surface 222A of the first region 221A and the incident surface 222B of the second region 221B. The light shielding portion 225 is provided so as to span a part of the incident surface 222A and a part of the incident surface 222B. The light shielding portion 225 faces the upper surface of the light shielding portion 144 provided in the lens holder 140. The light shielding portion 225 is provided so as to be slightly wider in both left and right directions than the left-right width of the light shielding portion 144, for example. The light shielding portion 225 can prevent the light emitted from the first light source 111A from passing through the second region 121B, and can also prevent the light emitted from the second light source 111B from passing through the first region 121A.

In this way, the image generating device 24B according to the second embodiment further includes a light shielding portion 225 of the lens 220 in addition to the light shielding portion 144 of the lens holder 140. With this configuration, light that cannot be completely blocked by the light shielding portion 144, such as light such as the fourth optical path 112D shown in FIG. 8, can be blocked by the light shielding portion 225 of the lens 220. This makes it possible to more reliably prevent light from the first light source 111A from entering the second region 121B from the incident surface 122B, or light from the second light source 111B from entering the first region 121A from the incident surface 122A, and the occurrence of glare can be further suppressed.

In the image generating device 24B of the second embodiment, the light shielding portion is provided with the light shielding portion 144 of the lens holder 140 and the light shielding portion 225 of the lens 220, but this is not limited to this. For example, the light shielding portion 144 of the lens holder 140 may not be provided, and only the light shielding portion 225 of the lens 220 may be provided.

Third Embodiment
Next, an image generating device 24C according to a third embodiment will be described with reference to Figs. 10 and 11. Members with the same reference numerals as those in the image generating device 24A according to the first embodiment have the same configuration as the image generating device 24A, and therefore their description will be omitted. Fig. 10 is a cross-sectional view of the image generating device 24C. Fig. 11 is a perspective view of the lens 320 as viewed from the light sources 111A and 111B side.
In the image generating device 24C, the shape of the lens 320 disposed on the upper side of the light source substrate 110 is different from that of the lens 120 of the image generating device 24A according to the first embodiment. In addition, the lens holder 340 provided in the image generating device 24C is different from the lens holder 140 of the image generating device 24A according to the first embodiment in that it does not have a light blocking portion.

10 and 11, the entrance surface 322 of the lens 320 is provided with a light-shielding portion 325 capable of refracting light emitted from the light sources 111A and 111B and entering the lens 320. On both the left and right sides of the lens 320, mounting portions 326 having mounting holes 327 for the screws 161 are provided.

The light-shielding portion 325 is provided in the center of the lens 320 in the left-right direction. The light-shielding portion 325 is provided in a third region 321C formed between the first region 321A and the second region 321B. The light-shielding portion 325 is provided as a protrusion that protrudes downward from the third region 321C toward the first light source 111A and the second light source 111B side, below the incident surface 322A of the first region 321A and the incident surface 322B of the second region 321B. The light-shielding portion 325 is formed integrally with the lens 320 as part of the lens 320.

The light shielding portion 325 has, for example, a rectangular shape in the cross-sectional view of FIG. 10. The light shielding portion 325 extends along the front-rear direction of the lens 320. The light shielding portion 325 is disposed between the first light source 111A and the second light source 111B in the space 170 formed between the first light source 111A and the second light source 111B and the lens 120. The light shielding portion 325 transmits light emitted from the first light source 111A and transmits light emitted from the second light source 111B.

In this way, the image generating device 24C according to the third embodiment includes a light shielding portion 325 as a protrusion that protrudes from the third region 321C formed between the first region 321A and the second region 321B toward the first light source 111A and the second light source 111B on the incident surface 322 of the lens 320. According to this configuration, since the light shielding portion 325 is provided as a protrusion protruding from the lens 320, the light emitted from the first light source 111A and traveling toward the second region 321B can be refracted by the light shielding portion 325 so as not to enter the display device 130, for example, as in the fifth optical path 112E shown in FIG. 10. Although not shown, in a similar manner, the light emitted from the second light source 111B and traveling toward the first region 321A can be refracted by the light shielding portion 325 so as not to enter the display device 130. This makes it possible to suppress glare that may occur when light from first light source 111A passes through second region 321B, or when light from second light source 111B passes through first region 321A. In addition, since light shielding portion 325 is provided integrally with lens 320, the number of parts can be reduced compared to when light shielding portion 325 is provided separately from lens 320. This allows image generating device 24C to be manufactured at low cost.

(Fourth embodiment)
Next, an image generating device 24D according to a fourth embodiment will be described with reference to Figs. 12 and 13. Members with the same reference numerals as those in the image generating device 24A according to the first embodiment have the same configuration as the image generating device 24A, and therefore their description will be omitted. Fig. 12 is a cross-sectional view of the image generating device 24D. Fig. 13 is a perspective view of a lens holder 440 provided in the image generating device 24D, as viewed from the lens 120 side.
In the image generating device 24D, the configuration of a lens holder 440 disposed on the upper side of a light source substrate 110 is different from that of the lens holder 140 of the image generating device 24A according to the first embodiment.

13, the lens holder 440 has a pair of mounting portions 441 in which mounting holes 442 for the screws 161 are formed, and a frame portion 443 provided between the pair of mounting portions 441. The frame portion 443 is provided with a reflecting portion 444 (an example of a light blocking portion). The reflecting portion 444 is provided in the center portion in the left-right direction of the lens holder 440 so as to connect between the front frame portion 443A and the rear frame portion 443B along the front-rear direction of the lens holder 440. The reflecting portion 444 is formed integrally with the lens holder 440.

12, the reflecting portion 444 has a flared shape in which the width in the left-right direction increases toward the bottom in a cross-sectional view. That is, the width of the lower surface 444D of the reflecting portion 444 is greater than the width of the upper surface 444C of the reflecting portion 444. The left and right side surfaces of the reflecting portion 444 form a first reflecting surface 444A and a second reflecting surface 444B that can reflect the light emitted from the first light source 111A and the second light source 111B. The first reflecting surface 444A and the second reflecting surface 444B are formed as a concavely curved reflecting surface. For example, a metal such as aluminum is vapor-deposited on the first reflecting surface 444A and the second reflecting surface 444B. The reflecting portion 444 is disposed between the first light source 111A and the second light source 111B in the space 170 formed between the first light source 111A and the second light source 111B and the lens 120. The first reflecting surface 444A reflects, toward the first region 121A, the light emitted from the first light source 111A and traveling toward the second region 121B. The second reflecting surface 444B reflects, toward the second region 121B, the light emitted from the second light source 111B and traveling toward the first region 121A.

Thus, according to the image generating device 24D of the fourth embodiment, the lens holder 440 includes a reflecting portion 444 having a first reflecting surface 444A and a second reflecting surface 444B that are concavely curved. The first reflecting surface 444A is disposed in a position in the space 170 formed between the first light source 111A and the second light source 111B and the lens 120 to reflect light from the first light source 111A toward the second region 121B toward the first region 121A. The second reflecting surface 444B is disposed in a position in the space 170 to reflect light from the second light source 111B toward the first region 121A toward the second region 121B. For this reason, for example, as in the sixth optical path 112F shown in FIG. 12, the light emitted from the first light source 111A and traveling toward the second region 121B can be reflected by the first reflecting surface 444A and made to enter the display device 130 as light approximately parallel to the optical axis 115A. Similarly, the light emitted from the second light source 111B and traveling toward the first region 121A can be reflected by the second reflecting surface 444B as shown in the seventh optical path 112G, for example, and can be made to enter the display device 130 as light approximately parallel to the optical axis 115B. This makes it possible to suppress the occurrence of glare without reducing the effective utilization rate of the light emitted from the first light source 111A and the second light source 111B.

Fifth Embodiment
An image generating device 24E according to the fifth embodiment will be described with reference to Fig. 15 to Fig. 20. Fig. 15 is a schematic cross-sectional view in the left-right direction showing the configuration of the image generating device 24E. Fig. 16 is a schematic cross-sectional view in the front-rear direction showing the configuration of the image generating device 24E. Members with the same reference numerals as those in the image generating device 24A according to the first embodiment have the same configuration as the image generating device 24A, and therefore will not be described.

15 and 16, the image generating device 24E includes a light source 111, a lens 420, and a liquid crystal device 230. The lens 420 is disposed above the light source 111. The liquid crystal device 230 is disposed above the lens 420.

The light source 111 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 light, green laser light, and blue laser light, respectively. The light source 111 is mounted on a light source substrate 110. In this example, the light source 111 includes a first light source 111A and a second light source 111B. The first light source 111A and the second light source 111B are arranged on the light source substrate 110 at a certain distance apart in the left-right direction. The light source substrate 110 is, for example, a printed circuit board on which electrical circuit wiring is printed on or inside a base substrate made of an insulator.

The lens 420 is, for example, an aspheric convex lens in which both the entrance surface 422, through which the light from the light source 111 is incident, and the exit surface 423, through which the incident light is emitted, are formed in a convex shape. The lens 420 is configured to transmit the light emitted from the light source 111 and emit it toward the liquid crystal device 230.

In this example, the lens 420 has a first region 421A that transmits the first light emitted from the first light source 111A and a second region 421B that transmits the second light emitted from the second light source 111B. The first region 421A is an aspheric convex lens corresponding to the first light source 111A. The second region 421B is an aspheric convex lens corresponding to the second light source 111B. The entrance surface 422A of the first region 421A and the entrance surface 422B of the second region 421B are convex entrance surfaces that bulge slightly downward. The exit surface 423A of the first region 421A and the exit surface 423B of the second region 421B are convex exit surfaces that bulge upward. A right part of the first region 421A arranged on the left side and a left part of the second region 421B arranged on the right side are combined. The lens 420 is attached to a lens holder (not shown), for example, so that the center of the light-emitting surface of the first light source 111A is the focal position of the first region 421A and the center of the light-emitting surface of the second light source 111B is the focal position of the second region 421B.

The liquid crystal device 230 forms light for generating a predetermined image from light emitted from the light source 111 and transmitted through the lens 420. The liquid crystal device 230 is attached to the upper surface of the PGU housing (not shown) with the light emission surface for emitting the light for generating an image facing upward of the image generating device 24E, for example.

The liquid crystal device 230 has, for example, a liquid crystal panel 231 and a drive circuit (not shown). Each of the pixels constituting the liquid crystal panel 231 is controlled by the drive circuit to either transmit or block light that has passed through the lens 420. By controlling the transmission and blocking of light for each pixel, light for generating a predetermined image is formed.

Figure 17 is a diagram showing an example of the visual field V of an occupant when the virtual image object I1 is displayed by the HUD 20 so as to be superimposed on the real space outside the vehicle 1. Note that the visual field V shown in Figure 17 includes a part of the vehicle 1 (such as the bonnet).

A virtual image object I1 indicating vehicle speed information is displayed in the visual field V of the occupant. The liquid crystal device 230 forms light for generating an image indicating vehicle speed information by controlling the transmission and blocking of light for each pixel constituting the liquid crystal panel 231 so that the virtual image object I1 is displayed at a predetermined position within the virtual image displayable area R. Note that the rectangular frame indicated by the dashed line indicates the position of the virtual image displayable area R for convenience, and no frame actually exists. The virtual image displayable area R corresponds to the image formable area A shown in FIG. 15 and FIG. 16 in the liquid crystal device 230. In this example, the image formable area A in the liquid crystal device 230 is an area in which the pixels constituting the liquid crystal panel 231 are formed, and the virtual image displayable area R corresponds to the shape of the liquid crystal panel 231.

15 and 16, the lens 420 in the fifth embodiment has a wave processing 424 on the outer periphery P1 of the exit surface 423. The wave processing 424 can be formed at the same time as the lens 420 is molded using a mold in which the portion corresponding to the outer periphery P1 of the exit surface 423 is formed in a wave shape. The wave processing 424 is an example of a light diffusion process. In this example, as shown in FIG. 18, the wave processing 424 is applied over the entire circumference of the outer periphery P1 of the exit surface 423. That is, the wave processing 424 is applied over the outer periphery P1A of the exit surface 423A of the first region 421A and the outer periphery P1B of the exit surface 423B of the second region 421B. The light emitted from the outer periphery P1 of the exit surface 423 of the lens 420 is diffused by the wave processing 424 and reaches the outer periphery P10 of the image forming area A of the liquid crystal device 230 and its surroundings.

Figure 19 is a diagram showing the optical paths of light emitted from the first light source 111A and the second light source 111B in an image generating device 24Z in which no wave processing is applied to the outer periphery of the exit surface 123 of the lens 120.

19, light emitted from the first light source 111A is incident on the entrance surface 122A of the lens 120. Since the lens 120 is an aspheric convex lens like the image generating device 24E described above, most of the light emitted from the first light source 111A is incident on the first region 121A of the lens 120, becomes parallel to the optical axis 115A, and enters the liquid crystal device 230. For example, as shown in the first optical path 112A, light emitted from the outer periphery of the exit surface 123A becomes parallel to the optical axis 115A and reaches the outer periphery of the image forming area of the liquid crystal device 230.

Similarly, most of the light emitted from the second light source 111B enters the second region 121B, becomes parallel to the optical axis 115B, and enters the liquid crystal device 230. For example, as shown in the second optical path 112B, light emitted from the outer periphery of the exit surface 123B becomes parallel to the optical axis 115B and reaches the outer periphery of the image-formable region of the liquid crystal device 230.

The liquid crystal device 230 forms light for generating a predetermined image by controlling the transmission and blocking of light transmitted through the lens 120 for each pixel constituting the liquid crystal panel 231. However, for example, if light leaks from a pixel that should be blocked in the liquid crystal panel 231 of the liquid crystal device 230, there is a risk that the area other than the virtual image object I1 in the virtual image displayable area R shown in FIG. 17 will be perceived as faintly glowing. In the image generating device 24Z, the outer periphery of the image formable area of the liquid crystal device 230 is also irradiated with light in the same way as other parts, so the outline of the virtual image displayable area R may be noticeable.

20 is a diagram showing the optical paths of light emitted from the first light source 111A and the second light source 111B in the image generating device 24E. According to the image generating device 24E, the outer peripheral portion P1 of the exit surface 423 is subjected to wave processing 424, so that, as shown in FIG. 20, the light emitted from the outer peripheral portion P1 of the exit surface 423 is diffused by the wave processing 424 and enters the liquid crystal device 230. This makes it possible to reduce the light that reaches the outer peripheral portion P10 of the image formable area A in the liquid crystal device 230. Therefore, even if the area other than the virtual image object I1 in the virtual image displayable area R shown in FIG. 17 is faintly illuminated, the brightness of the outer peripheral portion of the virtual image displayable area R is low, so that the outline of the virtual image displayable area R can be made inconspicuous.

In addition, in the image generating device 24E, a wave processing 424 is applied to the lens 420 as a light diffusion processing. Therefore, light can be diffused with a simple configuration.

In the above embodiment, the lens 420 is subjected to a wave processing 424 as a light diffusion processing. However, the lens 420 can be subjected to a texture processing as a light diffusion processing. The texture processing can be formed by processing the lens 420 after the lens 420 is molded by a mold. In this case, too, it is possible to reduce the light that reaches the outer periphery P10 of the image formable area A of the liquid crystal device 230. Also, in the textured portion of the lens 420, some light is blocked and does not exit. Therefore, compared to the wave processing, it is possible to further reduce the light that reaches the outer periphery P10 of the image formable area A.

In the above embodiment, the wave processing 424 is applied to the entire circumference of the outer periphery P1 of the exit surface 423. However, the wave processing may be applied to a part of the outer periphery P1 of the exit surface 423. For example, when the area other than the virtual image object I1 in the virtual image displayable area R shown in FIG. 17 is faintly lit, the upper part of the rectangular outer periphery of the virtual image displayable area R is particularly likely to be recognized by the occupant. The wave processing may be applied to a part of the outer periphery P1 of the exit surface 423 that emits light that reaches a part of the outer periphery P10 of the image formable area A of the liquid crystal device 230 corresponding to the upper part of the outer periphery of the virtual image displayable area R. In this case, since the brightness of the upper part of the virtual image displayable area R is low, the outline of the virtual image displayable area R can be made less noticeable.

Sixth Embodiment
Next, an image generating device 24F according to a sixth embodiment will be described with reference to Figs. 21 to 23. Fig. 21 is a schematic cross-sectional view of the image generating device 24F in the left-right direction. Fig. 22 is a schematic cross-sectional view of the image generating device 24F in the front-rear direction. Fig. 23 is a view of the lens 520 as seen from the light source 111 side. In Figs. 21 and 22, the image formable area A and the outer periphery P10 of the liquid crystal device 230 are omitted. In the sixth embodiment, the same reference numbers are given to the same members as those constituting the image generating device 24E of the fifth embodiment, and their description will be omitted for convenience.

21 and 22, the image generating device 24F includes a light source 111, a lens 520, and a liquid crystal device 230. The lens 520 is disposed above the light source 111. The liquid crystal device 230 is disposed above the lens 520. The light source 111 is mounted on the light source substrate 110. The light source 111 includes a first light source 111A and a second light source 111B.

The lens 520 is, for example, an aspheric convex lens in which both the entrance surface 522, where the light from the light source 111 is incident, and the exit surface 523, where the incident light is exited, are formed in a convex shape. The lens 520 is configured to transmit or reflect the light emitted from the light source 111 and emit it toward the liquid crystal device 230.

In this example, the lens 520 has a first region 521A that transmits the first light emitted from the first light source 111A and a second region 521B that transmits the second light emitted from the second light source 111B. The first region 521A is an aspheric convex lens corresponding to the first light source 111A. The second region 521B is an aspheric convex lens corresponding to the second light source 111B. The entrance surface 522A of the first region 521A and the entrance surface 522B of the second region 521B are convex entrance surfaces that bulge slightly backward. The exit surface 523A of the first region 521A and the exit surface 523B of the second region 521B are convex exit surfaces that bulge forward. A right part of the first region 521A arranged on the left side and a left part of the second region 521B arranged on the right side are combined. The lens 520 is attached to a lens holder (not shown) so that the center of the light-emitting surface of the first light source 111A is the focal position of the first region 521A and the center of the light-emitting surface of the second light source 111B is the focal position of the second region 521B.

21 and 22, the lens 520 in the sixth embodiment has a wave processing 524 applied over the outer periphery P2 of the incident surface 522. The wave processing 524 is an example of a light diffusion processing. In this example, as shown in FIG. 23, the wave processing 524 is applied over the entire circumference of the outer periphery P2 of the incident surface 522. That is, the wave processing 524 is applied over the outer periphery P2A of the incident surface 522A of the first region 521A and the outer periphery P2B of the incident surface 522B of the second region 521B.

If no wave processing is applied to the outer periphery P2 of the incident surface 522 of the lens 520, the light emitted from the light source 111 and irradiated onto the outer periphery P2 of the incident surface 522 enters the lens 520, passes through the lens 520, and exits from the outer periphery P3 of the exit surface 523.

In contrast, in the image generating device 24F, the outer periphery P2 of the incident surface 522 is subjected to a wave processing 524. The light emitted from the light source 111 and irradiated to the outer periphery P2 of the incident surface 522 is diffused by the wave processing 524 and enters the lens 520, so that the light emitted from the outer periphery P3 of the exit surface 523 can be reduced. This can reduce the light that reaches the outer periphery P10 of the image formable area A in the liquid crystal device 230. Therefore, even if the area other than the virtual image object I1 in the virtual image displayable area R shown in FIG. 17 is faintly illuminated, the brightness of the outer periphery of the virtual image displayable area R is low, so that the outline of the virtual image displayable area R can be made inconspicuous.

In the above embodiment, the lens 520 is subjected to wave processing 524 as a light diffusion processing. However, the lens 520 can be subjected to embossing processing as a light diffusion processing. In this case as well, it is possible to reduce the light that reaches the outer periphery P10 of the image formable area A of the liquid crystal device 230. Also, in the embossed portion of the lens 520, some light is blocked and does not exit. Therefore, compared to wave processing, it is possible to further reduce the light that reaches the outer periphery P10 of the image formable area A.

In the above embodiment, the wave processing 524 is applied around the entire outer periphery P2 of the incident surface 522. However, the wave processing may be applied to a portion of the outer periphery P2 of the incident surface 522. For example, the wave processing may be applied to a portion of the outer periphery P2 of the incident surface 522 so as to reduce the light reaching a portion of the outer periphery of the image formable area A of the liquid crystal device 230 corresponding to the upper portion of the outer periphery of the virtual image displayable area R shown in FIG. 17. In this case, since the brightness of the upper portion of the virtual image displayable area R is low, the outline of the virtual image displayable area R can be made less noticeable.

Seventh Embodiment
Next, an image generating device 24G according to a seventh embodiment will be described with reference to Fig. 24. Fig. 24 is a schematic cross-sectional view of the image generating device 24G in the left-right direction. In Fig. 24, the image formable area A and the outer periphery P10 of the liquid crystal device 230 are omitted. In the seventh embodiment, the same reference numerals are given to the same members as those constituting the image generating device 24E of the fifth embodiment, and the description thereof will be omitted for convenience.

24, the image generating device 24G includes a light source 111, a lens 620, and a liquid crystal device 230. The lens 620 is disposed above the light source 111. The liquid crystal device 230 is disposed above the lens 620. The light source 111 is mounted on the light source substrate 110. The light source 111 includes a first light source 111A and a second light source 111B.

The lens 620 is, for example, an aspheric convex lens in which both the entrance surface 622, where the light from the light source 111 is incident, and the exit surface 623, where the incident light is emitted, are formed in a convex shape. The lens 620 is configured to transmit or reflect the light emitted from the light source 111 and emit it toward the liquid crystal device 230.

In this example, the lens 620 has a first region 621A that transmits the first light emitted from the first light source 111A and a second region 621B that transmits the second light emitted from the second light source 111B. The first region 621A is an aspheric convex lens corresponding to the first light source 111A. The second region 621B is an aspheric convex lens corresponding to the second light source 111B. The entrance surface 622A of the first region 621A and the entrance surface 622B of the second region 621B are convex entrance surfaces that bulge slightly backward. The exit surface 623A of the first region 221A and the exit surface 623B of the second region 621B are convex exit surfaces that bulge forward. A right part of the first region 621A arranged on the left side and a left part of the second region 621B arranged on the right side are combined. The lens 620 is attached to a lens holder (not shown) so that the center of the light emitting surface of the first light source 111A is the focal position of the first region 621A and the center of the light emitting surface of the second light source 111B is the focal position of the second region 621B.

In the seventh embodiment, the lens 620 has a textured finish 624 applied over the outer periphery P4 of the incident surface 622 and the outer periphery P5 of the exit surface 623. The textured finish 624 is an example of a light diffusion finish. In this example, the textured finish 624 is applied over the outer periphery P4A of the incident surface 622A of the first region 621A and the outer periphery P4B of the incident surface 622B of the second region 621B. The textured finish 624 is applied over the outer periphery P5A of the exit surface 623A of the first region 621A and the outer periphery P5B of the exit surface 623B of the second region 621B.

According to the image generating device 24G, the outer periphery P4 of the incident surface 622 is textured 624, so that the light emitted from the light source 111 and irradiated to the outer periphery P4 of the incident surface 622 is diffused by the textured 624 and enters the lens 620. In addition, a part of the light irradiated to the outer periphery P4 of the incident surface 622 is blocked by the textured 624. This makes it possible to reduce the light emitted from the outer periphery P5 of the exit surface 623. In addition, the outer periphery P5 of the exit surface 623 is textured 624, so that the light emitted from the outer periphery P5 of the exit surface 623 is diffused by the textured 624 and enters the liquid crystal device 230. In addition, a part of the light emitted from the outer periphery P5 of the exit surface 623 is blocked by the textured 624. This makes it possible to reduce the light that reaches the outer periphery P10 of the image formable area A in the liquid crystal device 230. Therefore, even if areas other than the virtual image object I1 within the virtual image displayable area R shown in Figure 17 are faintly illuminated, the brightness of the outer periphery of the virtual image displayable area R is low, so the contour of the virtual image displayable area R can be made inconspicuous.

In the above embodiment, the embossing 624 is applied to the entire circumference of the outer periphery P4 of the incident surface 622 and the outer periphery P5 of the exit surface 623. However, the embossing may be applied to a part of the outer periphery P4 of the incident surface 622. Also, the embossing may be applied to a part of the outer periphery P5 of the exit surface 623. For example, the lens 620 may be formed so that the embossed area of the outer periphery P5 of the exit surface 623 is larger than the embossed area of the outer periphery P4 of the incident surface 622. In this case, the light diffusion at the outer periphery P4 of the incident surface 622 is minimized to guide the light from the lens 620 to the liquid crystal device 230, while the light reaching the outer periphery P10 of the image formable area A of the liquid crystal device 230 can be reduced.

In addition, in the above embodiment, the lens 620 is embossed as a light diffusion treatment. However, the lens 620 may be waved as a light diffusion treatment.

Eighth embodiment
Next, an image generating device 24H according to an eighth embodiment will be described with reference to Fig. 25. Fig. 25 is a schematic cross-sectional view of the image generating device 24H in the left-right direction. In Fig. 25, the image formable area A and the outer periphery P10 of the liquid crystal device 230 are omitted. In the eighth embodiment, the same reference numerals are given to the same members as those constituting the image generating device 24E of the fifth embodiment, and the description thereof will be omitted for convenience.

25, the image generating device 24H includes a light source 111, a lens 720, and a liquid crystal device 230. The lens 720 is disposed above the light source 111. The liquid crystal device 230 is disposed above the lens 720. The light source 111 is mounted on the light source substrate 110. The light source 111 includes a first light source 111A and a second light source 111B.

The lens 720 is, for example, an aspheric convex lens in which both the entrance surface 722, where the light from the light source 111 is incident, and the exit surface 723, where the incident light is exited, are formed in a convex shape. The lens 720 is configured to transmit or reflect the light emitted from the light source 111 and emit it toward the liquid crystal device 230.

In this example, the lens 720 has a first region 721A that transmits the first light emitted from the first light source 111A and a second region 721B that transmits the second light emitted from the second light source 111B. The first region 721A is an aspheric convex lens corresponding to the first light source 111A. The second region 721B is an aspheric convex lens corresponding to the second light source 111B. The entrance surface 722A of the first region 721A and the entrance surface 722B of the second region 721B are convex entrance surfaces that bulge slightly backward. The exit surface 723A of the first region 721A and the exit surface 723B of the second region 721B are convex exit surfaces that bulge forward. A right portion of the first region 721A located on the left side and a left portion of the second region 721B located on the right side are combined. The lens 720 is attached to a lens holder (not shown) so that the center of the light-emitting surface of the first light source 111A is the focal position of the first region 721A and the center of the light-emitting surface of the second light source 111B is the focal position of the second region 721B.

The lens 720 in the seventh embodiment is processed so that the radius of curvature becomes larger the further outward at the outer periphery P6 around the entire circumference of the outer periphery P6 of the exit surface 723. This processing is an example of light diffusion processing. In this example, the lens 720 is processed so that the radius of curvature becomes larger the further outward at the outer periphery P6A of the exit surface 723A of the first region 721A and the outer periphery P6B of the exit surface 723B of the second region 721B.

According to the image generating device 24H, the outer periphery P6 of the exit surface 723 is processed so that the radius of curvature increases toward the outside, so that the light emitted from the outer periphery P6 of the exit surface 723 is diffused and enters the liquid crystal device 230. This can further reduce the light that reaches the outer periphery P10 of the image formable area A of the liquid crystal device 230. Therefore, even if the area other than the virtual image object I1 in the virtual image displayable area R shown in FIG. 17 is faintly illuminated, the brightness of the outer periphery of the virtual image displayable area R is low, so the outline of the virtual image displayable area R can be made inconspicuous.

In the above embodiment, the outer periphery P6 of the exit surface 723 is processed so that the radius of curvature increases as it goes outward over the entire circumference. However, the outer periphery P6 of the exit surface 723 may be processed so that the radius of curvature increases as it goes outward in a portion of the area. For example, the outer periphery P6 of the exit surface 723 that emits light that reaches the image formable area A of the liquid crystal device 230 corresponding to the upper portion of the outer periphery of the virtual image displayable area R shown in FIG. 17 may be processed so that the radius of curvature increases as it goes outward in a portion of the area. In this case, since the brightness of the upper portion of the virtual image displayable area R is low, the outline of the virtual image displayable area R can be made less noticeable.

In the fifth to eighth embodiments, the image generating devices 24E, 24F, 24G, and 24H are provided with a first light source 111A and a second light source 111B as the light source 111. The lenses 420, 520, 620, and 720 have a first region 421A, 521A, 621A, and 721A and a second region 421B, 521B, 621B, and 721B. However, the image generating devices 24E, 24F, 24G, and 24H may have one light source, and the lenses 420, 520, 620, and 720 may have one region that transmits light emitted from the light source. Alternatively, the image generating devices 24E, 24F, 24G, and 24H may have three or more light sources, and the lenses 420, 520, 620, and 720 may have three or more regions that transmit light emitted from the corresponding light sources.

In the fifth to eighth embodiments, the lenses 420, 520, 620, and 720 are aspheric convex lenses. However, the lenses 420, 520, 620, and 720 may also include lenses of other shapes.

In the fifth to eighth embodiments, the image generating devices 24E, 24F, 24G, and 24H may include, for example, a heat sink provided on the rear surface of the light source substrate 110. The heat sink can dissipate heat generated from the light source substrate 110. The image generating devices 24E, 24F, 24G, and 24H may also include a diffusion sheet or the like between the lenses 420, 520, 620, and 720 and the liquid crystal device 230.

In the fifth to eighth embodiments, the lenses 420, 620, and 720 have been subjected to light diffusion processing on the outer peripheral portions P1, P5, and P6 of the exit surface 423, 623, and 723. The lenses 520 and 620 have been subjected to light diffusion processing on the outer peripheral portions P2 and P4 of the entrance surface 522 and 622. However, if the lenses 420, 620, and 720 can reduce the light reaching the outer peripheral portion P10 of the image-formable area A of the liquid crystal device 230, the light diffusion processing can be applied to the portions other than the outer peripheral portions P1, P5, and P6 of the exit surface 423, 623, and 723. If the lenses 520 and 620 can reduce the light reaching the outer peripheral portion P10 of the image-formable area A of the liquid crystal device 230, the light diffusion processing can be applied to the portions other than the outer peripheral portions P2 and P4 of the entrance surface 522 and 622.

Although the embodiment of the present disclosure has been described above, it goes without saying that the technical scope of the present invention should not be interpreted as being limited by the description of this embodiment. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications of the embodiment are possible 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 equivalents.

In the first to eighth embodiments described above, the light emitted from the image generating device 24 is configured to be reflected by the concave mirror 26 and irradiated onto the windshield 18, but this is not limited to the above. For example, the light reflected by the concave mirror 26 may be irradiated onto a combiner (not shown) provided on the inside of the windshield 18. The combiner is formed, for example, of a transparent plastic disk. A portion of the light irradiated onto the combiner from the image generating device 24 of the HUD main body 21 is reflected towards the occupant's viewpoint E, in the same way as when light is irradiated onto the windshield 18.

Although the vehicle driving modes have been described as including a fully automated driving mode, an advanced driving assistance mode, a driving assistance mode, and a manual driving mode, the vehicle driving modes should not be limited to these four modes. The vehicle driving modes may include at least one of these four modes. For example, the vehicle driving modes may be capable of executing only one of them.

Furthermore, the classification and display format of the vehicle's driving modes may be changed as appropriate in accordance with the laws, regulations, and rules related to autonomous driving in each country. Similarly, the definitions of "fully autonomous driving mode," "advanced driving assistance mode," and "driving assistance mode" described in the description of this embodiment are merely examples, and these definitions may be changed as appropriate in accordance with the laws, regulations, and rules related to autonomous driving in each country.

This application is based on Japanese Patent Application No. 2020-078252 filed on April 27, 2020 and Japanese Patent Application No. 2020-088277 filed on May 20, 2020, the contents of which are incorporated herein by reference.

Claims (7)

An image generating device that generates an image for a head-up display,
At least one light source;
a substrate on which the at least one light source is mounted;
a lens that transmits light emitted from the at least one light source;
a display device that forms light for generating the image using light transmitted through the lens;
the lens has an entrance portion having an entrance surface into which the light from the at least one light source is incident and a flange portion provided contiguous with the entrance surface, an exit surface from which the light exits, and a standing wall surface which is a portion connecting the entrance portion and the exit surface and rises linearly from at least a part of the outer periphery of the entrance portion toward the exit surface and has a shape which spreads outward from the center of the lens as it moves from the exit surface toward the entrance portion,
a light shielding portion that blocks the light that is internally reflected by the upright wall surface is provided around at least a portion of the periphery of the display device ;
An image generating apparatus, wherein the lens and the display device are arranged along an optical axis of the light source . The image generating device according to claim 1, wherein the inclination angle of the vertical wall surface with respect to the center line of the lens is 5 degrees or more. The image generating device of claim 2, wherein the inclination angle is 15 degrees or more. a housing for holding the display device;
The image generating device according to claim 1 , wherein the housing includes the light blocking portion. The image generating device according to any one of claims 1 to 4, wherein the standing wall surface rises from only a portion of the outer periphery of the entrance portion. The image generating device according to any one of claims 1 to 5, wherein both the entrance surface and the exit surface are convex. An image generating device according to any one of claims 1 to 6 ;
A head-up display comprising: at least one reflecting portion that reflects the light emitted by the image generating device so that the light is irradiated onto a windshield or a combiner.

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