Head-up display device and display control method

Abstract

To provide a head-up display device and a display control method allowing a driver to perceive display contents in each display area even while a vehicle is traveling at a high speed.SOLUTION: Display setting data for showing formation positions of a first area and a second area corresponding to a vehicle speed are stored in a storage of an HUD device. In the display setting data, positions of the first area and the second area are set closer to the center of a visual field in front of a driver as a vehicle speed is faster. A control portion of the HUD device acquires a current vehicle speed on the basis of a signal from a vehicle speed sensor, and adjusts positions of the first area and the second area on the basis of a current vehicle speed and display setting data.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a technology for displaying an image in a position that overlaps with a driver's view ahead. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is a head-up display device (hereinafter referred to as HUD) that displays an image in front of a passenger (hereinafter referred to as a driver) seated in the driver's seat by irradiating image light onto the windshield or the like of a vehicle.

[0003] Patent Document 1 discloses a HUD that displays different types of information in two display areas. In Patent Document 1, the two display areas are realized using two displays, a first display and a second display. Light emitted by the first display is irradiated onto a first illumination area set on the windshield. Image light emitted by the second display is irradiated onto a second illumination area set on the windshield. The second illumination area is set so as not to overlap with the first illumination area. The illumination area can correspond to the display area. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-105993 Summary of the Invention [Problem to be solved by the invention]

[0005] In the configuration of Patent Document 1, the first and second illumination areas are fixed on the windshield, and therefore the display areas of the images formed by the displays as seen by the driver are also fixed.

[0006] However, as the vehicle speed increases, the driver's effective field of view tends to narrow. During high-speed driving, the first and second display areas may be out of the driver's effective field of view, which may cause the driver to be unable to see the information displayed in each display area.

[0007] The present disclosure has been made based on the above points, and one of its objectives is to provide a head-up display device and a display control method that allow the driver to easily perceive the display content in each display area even when the vehicle is traveling at high speed. [Means for solving the problem]

[0008] The head-up display device disclosed herein is a head-up display device that displays different types of information in a first display area and a second display area located in front of the driver's seat, and includes a display setting memory unit (53) that stores display setting data that indicates the positions of the first display area and the second display area according to the moving speed, and a display control unit (50) that controls the positions of the first display area and the second display area, where the display setting data is configured so that the higher the moving speed, the closer the first display area and the second display area are to the center of the driver's forward field of view, and the display control unit is configured to acquire the moving speed based on a signal from a speed sensor and change both the first display area and the second display area based on the display setting data and the current moving speed.

[0009] According to the above configuration, the display control unit moves both the first display area and the second display area to the center of the forward field of view in accordance with the current vehicle speed based on the vehicle speed and the display setting data, so that the information presented in each display area tends to fit within the driver's effective field of view, making it easier for the driver to perceive the display content in each display area even when the vehicle is traveling at high speed.

[0010] In addition, the display control method disclosed herein is a display control method implemented in a head-up display device that displays different types of information in a first display area and a second display area located in front of the driver's seat, and includes the steps of: reading out display setting data from a display setting memory unit (53) that stores display setting data indicating the positions of the first display area and the second display area according to the moving speed; acquiring the moving speed based on a signal from a speed sensor; and moving the positions of both the first display area and the second display area closer to the center of the driver's forward field of view than when the moving speed is less than the predetermined value, based on the display setting data and the current moving speed.

[0011] According to the display control method, when the vehicle speed reaches or exceeds a predetermined value, the set positions of the first display area and the second display area are moved closer to the center of the forward field of view, so that the driver can easily perceive the display contents of each display area even when the vehicle is traveling at high speed.

[0012] Note that the symbols in parentheses in the claims indicate a correspondence with the specific means described in the embodiments described below as one aspect, and do not limit the technical scope of the present disclosure. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram for explaining an overall view of a HUD device. [Figure 2] FIG. 2 is a diagram for explaining a first area and a second area. [Figure 3] FIG. 1 is a block diagram of a HUD device. [Figure 4] FIG. 10 is a diagram showing an example of a setting value of the mirror angle according to the vehicle speed. [Figure 5] FIG. 10 is a diagram showing the display positions of the first area and the second area according to the vehicle speed. [Figure 6] FIG. 4 is a diagram for explaining the operation of a control unit. [Figure 7]FIG. 10 is a diagram showing another example of the setting value of the mirror angle according to the vehicle speed. [Figure 8] 8 is a diagram showing a display area for each vehicle speed range based on the display position setting shown in FIG. 7. FIG. [Figure 9] 10A and 10B are diagrams for explaining variations in display position setting according to vehicle speed. [Figure 10] FIG. 10 is a diagram showing another example of display position setting according to vehicle speed. [Figure 11] 10A and 10B are diagrams for explaining variations in display position setting according to vehicle speed. [Figure 12] FIG. 10 is a diagram illustrating a modified example of the HUD device. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present disclosure will be described below with reference to the drawings. FIG. 1 is a diagram showing an example of a schematic configuration of a head-up display device 1 according to the present disclosure. Hereinafter, the head-up display will be abbreviated as HUD (Head-Up Display). The HUD device 1 is mounted on and used in a vehicle such as a four-wheeled automobile. The host vehicle in the present disclosure refers to the vehicle in which the HUD device 1 is used.

[0015] The up-down direction and width direction of the HUD device 1 are set to correspond to the posture when the HUD device 1 is attached to a vehicle. Unless otherwise specified below (that is, basically), the directions indicated as front, rear, up, down, left, and right are expressed with respect to the vehicle. Specifically, the front-to-rear direction corresponds to the longitudinal direction of the vehicle. The left-to-right direction corresponds to the width direction of the host vehicle. The up-to-down direction corresponds to the height direction of the host vehicle. In this disclosure, the plane perpendicular to the height direction of the host vehicle is also referred to as the vehicle horizontal plane. When the vehicle is on a horizontal road surface, the vehicle horizontal plane may coincide with the actual horizontal plane.

[0016] <Overall configuration overview> The HUD device 1 projects image light onto a predetermined projection area on a windshield 2 provided in a vehicle, thereby displaying a virtual image on a forward extension of a line connecting the driver's eyes and the projection area. Note that the driver in this disclosure refers to a passenger sitting in the driver's seat.

[0017] The windshield 2 is a transparent member provided in front of the driver's seat. The windshield 2 is realized, for example, using laminated glass formed from two pieces of glass and an intermediate film provided between them. The windshield 2 corresponds to the projection member. The projection member may be a member that functions as a half mirror, such as a combiner. The projection member onto which the image light is irradiated may be provided separately from the windshield 2. In this disclosure, image light refers to light that forms a virtual image as an image perceived by the driver. Hereinafter, the image perceived by the driver will also be referred to as a HUD image. The driver can view the HUD image superimposed on the view in front of the vehicle.

[0018] The HUD device 1 is housed in an instrument panel 3 that extends downward and rearward from the lower end of the windshield 2 into the vehicle interior. An opening 3a is provided on the upper surface of the instrument panel 3 to allow the image light emitted by the HUD device 1 to pass through. A light-transmitting dustproof cover is provided over the opening 3a.

[0019] As will be described later, the HUD device 1 of this embodiment is configured so that the display area of ​​the HUD image can be changed up and down by rotating the concave mirror 30. The display area here corresponds to the position of the HUD image as seen by the driver. Each display area provides a different image depression angle θd. The image depression angle θd is a parameter that corresponds to the display position of the HUD image as seen by the driver in the height direction. The image depression angle θd corresponds to the amount of line-of-sight movement from the front of the vehicle to the HUD image. The image depression angle θd can be defined as a vector directed from the eye box Eb toward the center of the HUD image. The image depression angle can also be called the virtual image depression angle.

[0020] The image depression angle θd corresponds to the angle formed by a line connecting the shield projection position P, which is the projection position of the image light on the windshield 2, and the eye box Eb with respect to the horizontal plane of the vehicle. The eye box Eb is a viewpoint area in which the HUD image can be viewed, and is determined by the optical characteristics of the HUD device 1. In this disclosure, the term "display area" can be read as "display position."

[0021] Here, as an example, the HUD device 1 is configured to be able to selectively switch between a first area D1 and a second area D2 as the display area of ​​the HUD image. The second area D2 is a display area located relatively higher than the first area D1. The second area D2 corresponds to a display area having a smaller image depression angle θd than the first area D1. The first area D1 corresponds to the first display area, and the second area D2 corresponds to the second display area.

[0022] In the figure, P1 represents the shield projection position P corresponding to the first area D1, and P2 represents the shield projection position P corresponding to the second area D2. θd1 represents the image depression angle θd corresponding to the first area D1, and θd2 represents the image depression angle θd corresponding to the second area D2. Also, Cn in the figure indicates the center of the forward field of view, which is the central direction of the driver's field of view looking ahead of the vehicle. The center of the forward field of view is parallel to the front-to-rear direction and corresponds to the direction facing forward from the headrest / eye box Eb of the driver's seat.

[0023] Each display area is set to, for example, a rectangular shape. In one aspect, the second area D2 can be understood as a display area realized by rotating the concave mirror 30 that forms the first area D1. Figure 2 is a diagram showing an example of the positional relationship between the first area D1 and the second area D2.

[0024] In this embodiment, each display area is set so that the top of the first area D1 and the bottom of the second area D2 are adjacent. The vertical angle of view of each display area is set to 2 degrees, and the horizontal angle of view is set to 6 degrees. By setting the display so that the top of the first area D1 and the bottom of the second area D2 are approximately aligned, it becomes possible to virtually expand the vertical display area. Specifically, it becomes possible to set the vertical angle of view to 4 degrees.

[0025] The type of information, in other words, the content, displayed as a HUD image in each display area can be designed as appropriate. For example, the first area D1 is a display area for displaying a vehicle status image. The vehicle status image is an image showing information about predetermined items related to the status of the vehicle (hereinafter, "vehicle information"). The vehicle status image includes one or more types of information, such as vehicle speed, engine RPM, engine coolant temperature, shift position, and battery voltage. The vehicle status image may also include icons showing the system operating status, such as advanced driving assistance functions and autonomous driving functions.

[0026] The second area D2 is an area for displaying an event image corresponding to a detected event when the occurrence of a predetermined event is detected. Examples of events for which an image is displayed in the second area include approaching a route guidance point, detecting an object that may come into contact with the vehicle, and detecting driver fatigue, distraction, or poor physical condition. In the present disclosure, messages / icons indicating such events are also referred to as event information.

[0027] The event image may include, for example, one or more of a route guidance image, a warning image, a rest suggestion image, and a regulation notification image. A route guidance image is an image that shows the direction of travel at an intersection, the recommended lane to drive in, the remaining distance to a point where you need to turn right or left, etc. A route guidance image may also be called a turn-by-turn image. A route guidance image may be displayed when the remaining distance to the guidance point falls below a predetermined value.

[0028] An attention-warning image is an image that notifies the driver of the presence of another moving object that requires caution. An attention-warning other moving object is an object that poses a risk of collision with the vehicle. Moving objects include pedestrians, other vehicles, and animals. An attention-warning image can be an image with text such as "Watch your right side" or "Watch your left side." An attention-warning image can be displayed when there is another moving object for which the calculated collision risk is greater than or equal to a predetermined value. A rest suggestion image is an image that encourages a break and can be displayed when the driving duration exceeds a predetermined value. A restriction notification image is an image that notifies / warns that the speed limit has changed, the number of lanes will be reduced, etc. Various images can be images that combine text, icons, pictograms, etc.

[0029] The second area D2 is not an area where images are constantly displayed, but is enabled when a specific event occurs. In other words, the second area D2 is used as a temporary display area. Therefore, the second area D2 can also be called a temporary display area. On the other hand, the first area D1 can also be called a basic display area because it is an area where images related to the vehicle status are continuously displayed except when an event is detected (i.e., basically). Note that when the second area D2 is enabled, from the driver's perspective, an image related to a specific event appears to be popped up above the first area D1. For this reason, in the present disclosure, an event for using the second area D2 can also be called a pop-up event or a notification event.

[0030] The control unit 50, which will be described later, controls whether to use the first area D1 or the second area D2 as the image display area. When no pop-up event occurs, the vehicle status image remains displayed in the first area D1. Note that while the second area D2 is being used, images cannot be displayed in the first area D1. Therefore, information on items that must be displayed for driving operations or legal reasons, such as vehicle speed, may be displayed in parallel with the event information in the second area D2.

[0031] Note that both the first area D1 and the second area D2 have a fixed display position in the depth direction. For example, the first area D1 and the second area D2 are formed at positions that can be felt in front of the vehicle, about 3 m to 5 m from the driver. The position of the display area hereinafter refers to the angle formed by the direction from the instrument box Eb to the display area with respect to the center of the forward visual field, that is, the image depression angle.

[0032] In the present disclosure, the image depression angle is described assuming that the center of the forward visual field is 0°, with values below the center of the forward visual field being negative and values above being positive. The HUD device 1 of the present embodiment is configured to form a display area below the center of the forward visual field. Therefore, the image depression angles of the first area D1 and the second area D2 are negative. Raising the positions of the first area D1 and the second area D2 corresponds to bringing their respective image depression angles closer to 0°. As another aspect, the image depression angle may be expressed with positive values on the lower side. In any case, when it is assumed that the HUD image is formed below the center of the forward visual field, raising the display area corresponds to bringing the absolute value of the image depression angle closer to 0°.

[0033] <Configuration of HUD device 1> As shown in FIG. 1, the HUD device 1 includes a housing 10, a display 20, and a concave mirror 30. Although not shown in FIG. 1, as shown in FIG. 3, the HUD device 1 further includes a concave mirror motor 40 and a control unit 50. Furthermore, the HUD device 1 is connected to an image signal source 5 and a vehicle speed sensor 6.

[0034] The image signal source 5 is a device that outputs an image signal that is the source of a HUD image (e.g., a route guidance image). The image signal here may be still image data or a video signal. The image signal source 5 is, for example, a navigation device or an electronic control unit (ECU) that provides a driving assistance function or an automatic driving function. In this embodiment, the image signal source 5 is arranged outside the HUD device 1. The image signal source 5 is connected to the control unit 50 via an in-vehicle network or a dedicated line for video signals. In another aspect, the image signal source 5 may be built into the HUD device 1. In other words, the HUD device 1 may have a function for generating an image signal.

[0035] The vehicle speed sensor 6 is a sensor that outputs a signal indicating the moving speed of the vehicle (i.e., vehicle speed). The vehicle speed sensor 6 corresponds to a speed sensor. The HUD device 1 and the vehicle speed sensor 6 are connected via, for example, an in-vehicle network. Various other sensor signals may also be input to the HUD device 1, such as a shift position sensor, a brake sensor, and a driver status monitor (hereinafter referred to as DSM: Driver Status Monitor). The DSM is a sensor that analyzes an image of the driver's face to sequentially detect the driver's state, such as the direction of the driver's face and the level of drowsiness.

[0036] The housing 10 is configured to house components such as the display 20, concave mirror 30, concave mirror motor 40, and control unit 50. The housing 10 may be made of a resin or metal having a predetermined strength. The housing 10 is fixed to the vehicle, and its position and orientation relative to the windshield 2 are constant. The housing 10 also has a constant shape.

[0037] The display 20 is a device that emits HUD image light based on a control signal input from a control unit 50, which will be described later. The display 20 is sometimes called a picture generation unit (PGU) or a projector. In the present embodiment, as an example, the display 20 is a so-called liquid crystal type PGU that renders image light by transmitting backlight light through a liquid crystal panel (LCD: Liquid Crystal Display). That is, the display 20 has a liquid crystal panel 21 and a backlight 22. The backlight 22 is, for example, a module in which a large number of LEDs (Light Emitting Diodes) serving as point light sources are arranged in a matrix (row and column pattern). Note that the light-emitting elements serving as point light sources may be light-emitting transistors or the like. The backlight 22 corresponds to a light source unit. Furthermore, the LEDs or the like correspond to light-emitting elements.

[0038] The display 20 is mounted in the housing 10 with the display surface of the liquid crystal panel 21 facing the magnifying optical system. The display 20 displays each frame image of the video data on the display surface of the liquid crystal panel 21, and transmits light from the display surface using a backlight 22 to emit the image light toward the magnifying optical system. The magnifying optical system is a collection of optical components that guide the image light output from the display 20 to the windshield 2. The magnifying optical system includes a concave mirror 30. The magnifying optical system may consist of only the concave mirror 30, or may include a plane mirror, a lens, or the like in addition to the concave mirror 30.

[0039] The display 20 may be a PGU of a so-called laser scanning type that displays an image by scanning a laser beam in two dimensions using a MEMS (Micro Electro Mechanical Systems) scanner or the like. When the display 20 is of the laser scanning type, the display 20 may include a laser module that emits laser beam, a MEMS scanner that scans the laser beam emitted from the laser module in two dimensions, and a screen that diffuses the light scanned by the MEMS scanner. The display 20 may also be a PGU that uses DLP (Digital Light Processing, registered trademark). When the display 20 is of the DLP type, the display 20 includes a digital mirror device (hereinafter, referred to as DMD) provided with a large number of micromirrors and a projection light source that projects light toward the DMD.

[0040] The concave mirror 30 is configured to reflect the image light output from the display 20 toward the windshield 2 through an opening 3a provided in the instrument panel 3. In addition to guiding the image light to the windshield 2, the concave mirror 30 also serves to enlarge and display the HUD image formed by the image light. The concave mirror 30 is disposed inside the housing 10 at a position where it can project the image light incident from the display 20 onto the windshield 2.

[0041] The concave mirror 30 is configured so that its inclination angle with respect to the horizontal plane of the vehicle, in other words, its tilt angle, can be changed by the rotational drive of the concave mirror motor 40. A concave mirror rotation range, which is the range of angles within which the concave mirror 30 can be tilted from an appropriately designed basic position, is defined for the concave mirror 30. The basic position of the concave mirror 30 corresponds to the position of the concave mirror 30 when the rotation angle caused by the concave mirror motor 40 is set to 0 degrees. The concave mirror limit rotation angle, which is the angle serving as the boundary value defining the concave mirror rotation range, is set to, for example, 5 degrees, 10 degrees, or 15 degrees.

[0042] The concave mirror motor 40 is configured to provide power for rotating the concave mirror 30 around a predetermined rotation axis. A stepping motor, for example, can be used as the concave mirror motor 40. The concave mirror motor 40 may also be a servo motor. The output shaft of the concave mirror motor 40 is connected, directly or indirectly via a gear, to a member that provides the rotation axis of the concave mirror 30. As a result, the rotational force output by the concave mirror motor 40 is transmitted to the support member of the concave mirror 30, causing the concave mirror 30 to rotate.

[0043] The concave mirror motor 40 is driven by a control signal output from the control unit 50. That is, the concave mirror motor 40 rotates in the forward or reverse direction by an angle corresponding to the control signal input from the control unit 50. The concave mirror motor 40 also transmits rotation angle data to the control unit 50 indicating the current rotation angle of the concave mirror 30 relative to its basic position. The rotation angle can be detected using a variety of devices, such as a non-contact rotary sensor or a rotary potentiometer. The installation position of the concave mirror motor 40 may be designed as appropriate, and in this example, it is assumed to be located to the side of the concave mirror 30. Of course, the concave mirror motor 40 may also be located on the rear side of the concave mirror 30.

[0044] The projection light projected by the display 20 is reflected by the concave mirror 30 and directed toward the windshield 2. Changing the tilt angle of the concave mirror 30 changes the angle of incidence and projection position of the image light from the display 20 to the concave mirror 30. Changing the tilt angle of the concave mirror 30 also changes the irradiation position of the image light on the windshield 2. The tilt angle of the concave mirror 30 functions as a parameter for adjusting the display position of the HUD image. Hereinafter, the tilt angle of the concave mirror 30 will also be referred to as the mirror angle.

[0045] The control unit 50 is configured to control the operation of the display unit 20 and the concave mirror motor 40. The control unit 50 is electrically connected to both the display unit 20 and the concave mirror motor 40. The control unit 50 also receives as input an image signal output from an image signal source 5 provided outside the HUD device 1 and a vehicle speed signal output from a vehicle speed sensor 6. The control unit 50 corresponds to a display control unit.

[0046] The control unit 50 is configured as a computer. That is, the control unit 50 includes a processor 51 that executes various arithmetic processes, a volatile memory 52, a storage 53 that is a nonvolatile memory, an input / output circuit, and bus lines that connect these components. The processor 51 is, for example, an arithmetic core such as a CPU (Central Processing Unit). The memory 52 is, for example, a RAM (Random Access Memory). The storage 53 is, for example, a NAND-type flash memory. The processor 51 executes various processes by accessing the memory 52. ​​The input / output circuit is a circuit that allows the HUD device 1 to communicate with other devices. The input / output circuit is realized using analog circuit elements, ICs, etc.

[0047] The storage 53 stores a display control program, which is a program for causing a normal computer to function as the control unit 50. Execution of the display control program by the processor 51 corresponds to execution of a display control method corresponding to the display control program. As will be described later, the storage 53 also stores display setting data that defines the formation positions of the first area D1 and the second area D2 according to the vehicle speed. The display setting data may be part of the display control program. The storage 53 corresponds to a display setting storage unit.

[0048] The control unit 50 provides various functions by the processor 51 executing a HUD control program. The control unit 50 dynamically changes the display area of ​​the HUD image seen from the eyebox Eb by rotating the display 20 and the concave mirror 30. The various functions of the control unit 50 will be described below.

[0049] <Controller functions> As shown in FIG. 3, the control unit 50 includes, as functional units, an image signal acquisition unit F1, a display processing unit F2, a display position adjustment unit F3, and a motor control unit F4.

[0050] Each functional unit is realized, for example, by the processor 51 executing a HUD control program. Of course, some or all of the above-described functional units may be realized as hardware using an integrated circuit (IC) or a field-programmable gate array (FPGA). Alternatively, some or all of the functional blocks included in the control unit 50 may be realized by a CPU executing software and a hardware component working together.

[0051] The image signal acquisition unit F1 converts the image signal input from the image signal source 5 into a data format recognizable by the display processing unit F2 and outputs the converted data to the display processing unit F2. The display processing unit F2 controls the operation of the display device 20 and causes the display device 20 to output light corresponding to the display image, i.e., image light. For example, the display processing unit F2 causes the display device 20 to project image light that is the basis of a route guidance image. When multiple types of video data (in other words, information) are input, the display processing unit F2 can play a role in arbitrating / selecting the video data to be output to the display device 20. Which of the multiple types of video data is to be displayed may be determined based on a preset priority order.

[0052] The display position adjustment unit F3 switches the display area based on a signal input from the image signal source 5. That is, the display position adjustment unit F3 switches the display area from the first area D1 to the second area D2, or from the second area D2 to the first area D1.

[0053] For example, the display position adjustment unit F3 applies the first area D1 when a display request for a specific type of image for the second area D2 is not input from the image signal source 5. Examples of images for the second area D2 include route guidance images, caution images, and images suggesting rest. The type of image for the second area D2 may be registered in advance. Furthermore, when a display request for an image for the second area D2 is input from the image signal source 5, the display position adjustment unit F3 sets the display area to the second area D2. When input of the image for the second area D2 is finished while the second area D2 is being applied, the display area is returned from the second area D2 to the first area D1.

[0054] That is, the display position adjustment unit F3 determines whether to activate the first area D1 or the second area D2 depending on the display content. Note that the position of the display area is determined by the tilt angle (i.e., mirror angle) of the concave mirror 30, so switching the display area is equivalent to switching the mirror angle. The display position adjustment unit F3 determines a mirror target angle, which is a target value for the tilt angle of the concave mirror 30, depending on the selected display area / display content, and outputs it to the motor control unit F4. The target angle refers to the target value of the tilt angle.

[0055] The above describes the case where the display position adjustment unit F3 switches the display area depending on the type of image (display content) requested to be displayed, but the display position adjustment unit F3 may also switch the display area based on an instruction from the image signal source 5. If the image signal source 5 is configured to be able to output an area designation signal that is a signal that designates the display area, the display position adjustment unit F3 may select the display area based on the area designation signal.

[0056] Furthermore, the display position adjustment unit F3 of the present disclosure adjusts the positions of both the first area D1 and the second area D2 in the vertical direction according to the vehicle speed. Changing the position settings of the first area D1 and the second area D2 according to the vehicle speed will be described separately below. The display position adjustment unit F3 determines a mirror target angle according to the combination of vehicle speed and display content based on the display setting data described below, and outputs the result to the motor control unit F4.

[0057] The motor control unit F4 identifies the current tilt angle (posture) of the concave mirror 30 based on the rotation angle data provided from each of the concave mirror motors 40. The motor control unit F4 controls the concave mirror motors 40 so that the tilt angle of the concave mirror 30 matches the mirror target angle. For example, the motor control unit F4 determines the drive amount of the concave mirror motor 40 based on the difference between the current concave mirror angle, which is the current tilt angle of the concave mirror 30, and the mirror target angle. A control signal corresponding to the determined drive amount is generated and output to the concave mirror motor 40. The concave mirror motor 40 is driven to rotate based on the control signal input from the motor control unit F4, changing the tilt angle of the concave mirror 30. Accordingly, the incident position and incident angle of the image light on the concave mirror 30, and therefore the shield irradiation position and irradiation angle, are changed.

[0058] <Adjusting the display position according to vehicle speed> The display position adjustment unit F3 determines a mirror angle according to the current vehicle speed and display content based on display setting data registered in advance in the storage 53, and outputs the determined mirror angle as a mirror target angle to the motor control unit F4. The display setting data is data that defines the positions / depression angles of the first area D1 and the second area D2 according to the vehicle speed. Since the position of the display area is determined by the tilt angle (i.e., the mirror angle) of the concave mirror 30, the display setting data can essentially be data that indicates the tilt angle of the concave mirror 30 for realizing the first area D1 and the second area D2 according to the vehicle speed. The display setting data is set so that the first area D1 and the second area D2 move closer to the center of the forward field of view as the vehicle speed increases.

[0059] FIG. 4 is a conceptual diagram illustrating an example of display setting data. The mirror angle for each display area according to vehicle speed is set so as to achieve a desired image depression angle. The angle value in parentheses in FIG. 5 indicates the image depression angle achieved by the mirror angle set to the left of it. The mirror angle for each display area according to vehicle speed is designed by testing or numerical analysis, taking into consideration the configuration of the magnification optical system, the specifications of the display device 20, etc. The position of the display area can be expressed by the mirror angle value or the image depression angle. In this embodiment, a low speed mode set, a medium speed mode set, and a high speed mode set are prepared as position settings for each display area according to the vehicle speed. The low speed mode set indicates the mirror angle for each display area that is applied when the vehicle is in a low speed state. The low speed state refers to a state where the vehicle speed is less than 40 km / h. The medium speed mode set indicates the mirror angle for each display area that is applied when the vehicle is in a medium speed state. The medium speed state refers to a state where the vehicle speed is equal to or greater than 40 km / h and less than 80 km / h. The high speed mode set indicates the mirror angle for each display area that is applied when the vehicle is in a high speed state. The high speed state refers to a state where the vehicle speed is equal to or greater than 80 km / h. The speed value dividing the low speed state and the medium speed state is not limited to 40 km / h, but may be 30 km / h or 50 km / h. The speed value dividing the medium speed state and the high speed state is not limited to 80 km / h, but may be 100 km / h or 120 km / h.

[0060] The medium-speed mode set is set so that each display area is closer to the center of the forward field of view than the low-speed mode set. Specifically, the mirror angle for the first area in the low-speed mode set is set to a value such as 10° that results in an image depression angle of −6°, while the mirror angle for the first area in the medium-speed mode set is set to a value such as 5° that results in an image depression angle of −4°. In addition, the high-speed mode set is set so that each display area is closer to the center of the forward field of view than the medium-speed mode set. Specifically, the mirror angle for the first area in the high-speed mode set is set to a value that results in an image depression angle of -2°. The position of the second area D2 is also set so that it moves from below toward the center of the forward field of view as the vehicle speed increases, specifically, it moves upward. The display setting data can be saved in any format, such as a table, program code, or map.

[0061] Figure 5 is a diagram conceptually showing the positions of the first area D1 and the second area D2 according to vehicle speed classification. Figure 5 (A) shows the positions of the first and second areas at low speed, (B) shows the positions of the first and second areas at medium speed, and (C) shows the positions of the first and second areas at high speed. As shown in Figure 5, the higher the vehicle speed, the higher each display area moves.

[0062] However, in this embodiment, the control unit 50 is configured not to raise the display area any further once the vehicle speed reaches a predetermined value so that the HUD image does not overlap the center of the forward field of view. In other words, the display setting data registers the closest position, which is the upper limit position of the display area. The control unit 50 does not move the display area closer to the center of the forward field of view than the closest position, regardless of how much the vehicle speed increases. The closest position is set to an image depression angle of -2°, for example. The setting positions of the display area for each vehicle speed are all set to the closest position or below the closest position. The display position adjustment unit F3 outputs a mirror target angle, which is a target value for the tilt angle of the concave mirror 30, identified using the display setting data to the motor control unit F4.

[0063] The mirror angle shown in this disclosure is an example, and can be changed depending on the optical characteristics, etc., as described above. The mirror angle for each display area according to the vehicle speed can also vary depending on the position of the eye box Eb. Display setting data for each eye box Eb is stored in the storage 53. The control unit 50 uses the display setting data according to the driver's eye box Eb to control the position of the display area / mirror angle according to the vehicle speed and display content.

[0064] <About the flow for changing the display position set> 6 shows an example of the operation of the control unit 50 when the display area is changed. The flow shown in FIG. 6 may be executed sequentially, for example, every 200 milliseconds. The flow shown in the figure may also be executed when triggered by a change in the input signal from the image signal source 5.

[0065] Step S10 shown in Figure 6 is a step of reading out display setting data stored in storage 53. The read display setting data is cached in memory 52 or the like and is referenced as needed in subsequent processing. Step S10 may be performed at a predetermined timing, such as when the running power supply is turned on. Step S10 does not need to be performed every time; once it is performed once after the running power supply is turned on, it may be omitted thereafter.

[0066] Step S11 is a step for acquiring the current vehicle speed based on the output signal of the vehicle speed sensor 6. Step S12 is a step for determining whether the traveling state of the vehicle corresponds to a low speed state, a medium speed state, or a high speed state based on the vehicle speed acquired in step S11. The determination result of step S12 is temporarily stored in memory 52 together with the determination time.

[0067] Step S13 is a step in which the previously determined driving state of the vehicle is compared with the current determination result to determine whether the driving state has changed. If the previous determination result regarding the driving state and the current determination result are the same (S13 NO), the current setting is maintained (S14). On the other hand, if the previous determination result regarding the driving state and the current determination result are different (S13 YES), the display position adjustment unit F3 changes the display position setting and inputs data indicating the changed display position to the motor control unit F4 (S15). For example, if the driving state changes from a low speed state to a medium speed state, the display position setting is changed from the low speed mode set to the medium speed mode set. Accordingly, the position (depression angle) of the first area D1 as seen by the driver moves upward by about 2 degrees. Similarly, the position of the second area D2 also rises by about 2 degrees.

[0068] In a more preferred control mode, when the display position setting is changed, the display position adjustment unit F3 stores the time of change in the memory 52 (S16). Furthermore, the display position adjustment unit F3 performs processing to prevent the display position setting from being changed for a predetermined lock period from the time of change (S17). The lock period may be, for example, 5 or 10 seconds. If the display position setting is frequently changed in a short period of time, the first area D1 will continue to move, which may be annoying to the driver. To address this issue, by providing the lock period, it is possible to prevent the first area D1 from continuing to move in accordance with the vehicle speed. This ultimately reduces the risk of annoying the driver.

[0069] In addition to the display position adjustment according to the vehicle speed, the display position adjustment unit F3 also performs display area switching control according to the content of the displayed image. The display area switching control is a control for selecting whether to enable the first area D1 or the second area D2, and can be determined by an input signal from the image signal source 5.

[0070] <Effects> The driver's peripheral and effective fields of vision tend to narrow as the vehicle speed increases. For example, while the peripheral field of vision is approximately 100° at 40 km / h, it is said to narrow to nearly 30° at 130 km / h. Like peripheral vision, the effective field of vision also tends to narrow in proportion to vehicle speed. Therefore, in a configuration in which the display position of the HUD image is constant, depending on the vehicle speed, the HUD image may be outside the driver's effective field of vision, making it difficult for the driver to recognize the contents of the HUD image.

[0071] To address this issue, the control unit 50 adjusts the positions of the first area D1 and the second area D2 according to the vehicle speed based on the display setting data stored in the storage 53. The display setting data is set so that the higher the vehicle speed, the closer the first display position and the second display position are to the center of the forward field of view. Therefore, the control unit 50 operates to move the first display position and the second display position closer to the center of the forward field of view as the vehicle speed increases. As a result, the first area D1 and the second area D2 tend to fit within the driver's effective field of view even at high speeds. This in turn makes it easier for the driver to perceive the display content at each display position, even when the vehicle is traveling at high speeds.

[0072] Furthermore, the control unit 50 limits the information displayed in the first area D1 to vehicle information, and displays other information (i.e., event information) in the second area D2, which is closer to the center of the forward field of view than the first area D1. This configuration allows the driver to be notified of event information in an emphasized manner. Furthermore, this configuration also reduces the risk of annoyance to the driver. Specifically, the second area D2 is close to the driver's central field of view, which has the advantage of making it easily perceptible to the driver. However, continuously displaying an image in the second area D2 can be an annoyance to the driver. The second area D2 in this configuration is not an area where information is constantly displayed, which reduces the risk of annoyance to the driver. Furthermore, a configuration in which event information is temporarily displayed in an area where images are not normally displayed allows the driver to recognize the event information more effectively than a configuration in which event information is displayed in an area where information is constantly displayed.

[0073] Furthermore, the above configuration can also provide the following effects.

[0074] The control unit 50 moves each display area closer to the center of the forward field of view as the vehicle speed increases, and moves each display area farther from the center of the forward field of view as the vehicle speed decreases. This configuration, which moves each display area farther from the center of the forward field of view as the vehicle speed decreases, reduces the risk that the HUD image will obstruct the driver's field of view and cause annoyance to the driver.

[0075] The control unit 50 does not move the second area D2 above a predetermined closest position. The closest position here refers to a position where the HUD image is closest to the center of the forward field of view, where the absolute value of the image depression angle is a predetermined value (e.g., 1° or 2°). This configuration prevents the information displayed in the second area D2 from overlapping with the center of the forward field of view. In other words, it reduces the risk of the HUD image obstructing the driver's field of view.

[0076] When the vehicle speed is equal to or greater than a predetermined value, the control unit 50 fixes the second area D2 at the closest position. This prevents the information displayed in the second area D2 from overlapping with the center of the field of view. In addition, when the vehicle speed is equal to or greater than a predetermined value, the first area D1 also continues to be set a predetermined distance below the second area D2. This allows the vehicle information and event information to be viewed at different positions, even when driving at high speeds.

[0077] The control unit 50 changes the positions of the first area D1 and the second area D2 in stages according to the vehicle speed. By changing the display positions in stages, it is possible to reduce fluctuations in the display caused by fluctuations in the vehicle speed.

[0078] The HUD device 1 realizes the first area D1 and the second area D2 by controlling the attitude of the concave mirror 30. With this configuration, there is no need to increase the size of the display 20 in order to expand the display range of the HUD image. In other words, the display range can be expanded without increasing the size of the display 20.

[0079] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications described below are also included within the technical scope of the present disclosure. Furthermore, various modifications other than those described below can be implemented without departing from the gist of the present disclosure. For example, the various supplements and modifications described below can be implemented in appropriate combinations as long as no technical contradictions arise. Note that components having the same functions as the components described above are given the same reference numerals, and their description may be omitted. Furthermore, when only a portion of the configuration is mentioned, the above description can be applied to the other portions.

[0080] <Variation (1)> The control unit 50 may be configured not to form the second area D2 when the vehicle speed is equal to or greater than a predetermined value. For example, the control unit 50 may be configured to use only the first area D1 when the vehicle is traveling at high speeds, as shown in Fig. 7. This configuration corresponds to a configuration in which a mode is entered in which an image is not displayed in the second area D2 when the vehicle speed is equal to or greater than a predetermined value.

[0081] Fig. 8 is a diagram for explaining the transition of the display position according to the vehicle speed based on the display setting data shown in Fig. 7. Fig. 7(A) shows the display position in a low speed state, (B) shows the display position in a medium speed state, and (C) shows the display position in a high speed state. As shown in Fig. 8(C), the control unit 50 of this modified example does not apply the second area D2 in a high speed state.

[0082] In this modified example, the control unit 50 may stop displaying the event information itself when the vehicle is traveling at high speed. This configuration reduces the amount of information presented to the driver when the driving load is relatively high, such as when the vehicle is traveling at high speed. As a result, the driver can more easily concentrate on driving.

[0083] As another example, the control unit 50 may display the event information in the first area D1 only when the vehicle is traveling at high speed. This configuration allows the driver to check the event information even when the vehicle is traveling at high speed. This modification also prevents the HUD image from overlapping with the center of the forward field of view.

[0084] <Variation (2)> The lock period mentioned in the above embodiment may be omitted. The control unit 50 may change the display position setting in real time depending on the driving condition. Furthermore, the control unit 50 may set a lock period when raising the display position, but may not set a lock period when lowering the display position, and may lower the display position in real time to follow the vehicle speed. For example, if the driving condition transitions to a high speed state immediately after switching from the low speed mode set to the medium speed mode set, the medium speed mode set may be maintained at least for the lock period. On the other hand, if the driving condition returns to a low speed state immediately after switching from the low speed mode set to the medium speed mode set, the mode may be switched back to the low speed mode set even during the lock period.

[0085] A decrease in vehicle speed from a medium speed state to a low speed state may correspond to a situation in which the distance to the preceding vehicle has decreased. If the medium speed mode set is continued to be applied in such a situation, the HUD image may overlap with the preceding vehicle, which may result in a decrease in visibility of the HUD image. This modification has been made in response to the above problem. By gradually raising the display position while lowering the display position to follow the actual vehicle speed, it is possible to ensure visibility of the HUD image while reducing the risk of annoyance to the driver.

[0086] <Variation (3)> The above describes a mode in which the positions of the first area D1 and the second area D2 are gradually moved closer to the center of the forward field of view depending on the vehicle speed, as conceptually shown in (A) of FIG. 9 . However, this is not limiting. The control unit 50 may also change the set positions of the first and second areas substantially continuously depending on the vehicle speed, as shown in (B) of FIG. 9 . Note that, while the above describes a mode in which the closest position is set to -2°, the closest position may also be set to -1°, -3°, or the like. The depression angle setting value of the display area depending on the vehicle speed is also one example and can be changed as appropriate. For example, the depression angle of the first area D1 in the low-speed mode set may be set to -10° or -8°.

[0087] <Variation (4)> As shown in FIG. 10, the amount of increase in the display position according to the vehicle speed may be different between the first area D1 and the second area D2. For example, the amount of increase for each vehicle speed category in the first area D1 may be set to 1°, while the amount of increase for each vehicle speed category in the second area D2 may be set to 2°. The amount of increase in the first area D1 according to the vehicle speed may be set smaller than the amount of increase in the second area D2. Basically, if the display position of the first area D1, where an image is continuously displayed, changes significantly, this may cause discomfort to the driver. The above configuration ensures visibility of the first area D1 while reducing the risk of discomfort to the driver.

[0088] The control unit 50 may control the display position of the second area D2 so that it approaches the center of the forward field of view as the vehicle speed increases, while the display position of the first area D1 may be kept constant regardless of the vehicle speed. In other words, the control unit 50 may be configured to raise the display position of only the second area D2 according to the vehicle speed.

[0089] <Variation (5)> Although the above describes a mode in which the display area is moved only in the vertical direction, the method of changing the display area is not limited to this. The control unit 50 may be configured to change the display position in the depth direction depending on the vehicle speed, as shown in FIG. 11. Note that D1a in FIG. 11 indicates the position of the first area D1 in a low-speed state, and D2a indicates the position of the second area D2 in a low-speed state. D1b in FIG. 11 indicates the position of the first area D1 in a medium-speed state, and D2b indicates the position of the second area D2 in a medium-speed state. D1c in FIG. 11 indicates the position of the first area D1 in a high-speed state, and D2c indicates the position of the second area D2 in a high-speed state.

[0090] The control unit 50 may also move the display area in a lateral or diagonal direction according to the vehicle speed. The control unit 50 may be configured to move the first area D1 and the second area D2 closer to the center of the forward field of view as the vehicle speed increases.

[0091] <Variation (6)> Although the driving state of the vehicle has been described as being divided into three states: low speed state, medium speed state, and high speed state, the driving state according to the vehicle speed may be divided into four or more states, or may be divided into only two states. A stopped state may also be prepared as a vehicle state used for setting the display position. A display position set for a stopped state may be registered in the storage 53. The stopped state refers to a state in which the vehicle speed is 0, or a state in which the parking brake is on and the shift position is set to the parking position.

[0092] <Variation (7)> The control unit 50 may determine the positions of the first area D1 and the second area D2 based on a moving average value of the vehicle speed within a certain period of time, rather than following the observed value of the current vehicle speed. This configuration reduces the risk of the display position frequently moving dynamically and thus causing annoyance to the driver. The observation period used to calculate the moving average value may be different during acceleration and deceleration. For example, in an acceleration scenario, the control unit 50 determines the positions of the first area D1 and the second area D2 based on the average value of the vehicle speed over the most recent eight seconds. On the other hand, in a deceleration scenario, the control unit 50 determines the positions of the first area D1 and the second area D2 based on the average value of the vehicle speed over the most recent four seconds. In a deceleration scenario, adjusting the display position based on the average value of the vehicle speed over a relatively short period reduces the chance of the HUD image overlapping the preceding vehicle.

[0093] <Variation (8)> Although the above describes an embodiment in which the display area is switched and the display position set is changed by rotating the concave mirror 30, the method for achieving these controls is not limited to this. The control unit 50 may switch from the first area D1 to the second area D2 and change the display position set according to the vehicle speed by changing the tilt angle of the display 20 itself, rather than the concave mirror 30. In this case, the HUD device 1 may include a display motor as a display actuator that provides power for rotating the display 20. The display motor is, for example, a stepping motor or a servo motor. The display motor rotates by an angle corresponding to a control signal input from the control unit 50.

[0094] The control unit 50 may also realize the switching from the first area D1 to the second area D2 and the change of the display position set by rotating both the concave mirror 30 and the display 20. Furthermore, the control unit 50 may selectively use the rotation of the concave mirror 30 and the rotation of the display 20 depending on the purpose. For example, the control unit 50 may realize the switching from the first area D1 to the second area D2 by rotating the concave mirror 30, while changing the display position set in accordance with the vehicle speed by rotating the display 20.

[0095] 12, the HUD device 1 may have a plane mirror 60 provided between the display 20 and the concave mirror 30. When the HUD device 1 includes the plane mirror 60, the control unit 50 may realize at least one of switching from the first area D1 to the second area D2 and changing the display position set by rotating the plane mirror 60.

[0096] <Variation (9)> The above describes an embodiment in which the first area D1 and the second area D2 are realized by dynamically changing the tilt angle of the concave mirror 30 or the display 20 using one display 20, but this is not limiting. The HUD device 1 may be configured to realize the first area D1 and the second area D2 using two displays 20. In other words, the HUD device 1 may include a display 20 for the first area D1 and a display 20 for the second area D2. The control unit 50 may dynamically control the attitude of the plane mirror 60 or the display 20 for each display area using a motor, thereby changing the display position in accordance with the vehicle speed.

[0097] <Variation (10)> The present disclosure is applicable to a variety of vehicles that travel on roads. In addition, the present disclosure is not limited to vehicles, and may also be applied to airplanes and electric vertical take-off and landing (eVTOL) aircraft.

[0098] <Additional remarks> The various flowcharts shown in this disclosure are merely examples, and the number of steps constituting the flowcharts and the execution order of the processes can be changed as appropriate. Furthermore, the apparatus, system, and method described in this disclosure may be implemented by a special-purpose computer comprising a processor programmed to execute one or more functions embodied in a computer program. The apparatus and method described in this disclosure may be implemented using dedicated hardware logic circuits. The apparatus and method described in this disclosure may be implemented by one or more special-purpose computers configured by combining a processor that executes a computer program with one or more hardware logic circuits. A CPU, MPU, GPU, or the like can be used as the processor (computing core). Some or all of the functions of this disclosure may be implemented using a system-on-chip (SoC), an integrated circuit (IC), or an FPGA. The computer program of this disclosure may be stored as instructions executed by a computer on a computer-readable non-transitory tangible storage medium. Examples of the program storage medium include a hard-disk drive (HDD), a solid-state drive (SSD), and flash memory. [Explanation of symbols]

[0099] 6 Vehicle speed sensor (speed sensor), 20 Display, 30 Concave mirror (mirror), 40 Concave mirror motor, 50 Control unit (display control unit), 51 Processor, 52 Memory, 53 Storage (display setting storage), D1 First area (first display area), D2 Second area (second display area), S10 to S17 Steps

Claims

1. A head-up display device that displays different types of information in a first display area and a second display area located in front of a driver's seat, a display setting storage unit (53) in which display setting data is stored, the display setting data being data indicating the positions of the first display area and the second display area according to the moving speed; a display control unit (50) that controls the positions of the first display area and the second display area, the display setting data is configured so that the first display area and the second display area are positioned closer to the center of the driver's forward field of view as the moving speed increases, The display control unit acquiring the moving speed based on a signal from a speed sensor; and changing both the first display area and the second display area based on the display setting data and the current moving speed.

2. The display control unit, based on the display setting data, The first display area and the second display area are moved closer to the center of the forward field of view as the moving speed increases, and The head-up display device according to claim 1 , wherein the head-up display device is configured to move away from the center of the forward field of view as the moving speed decreases.

3. the display setting data includes data defining a display position where a depression angle with respect to the center of the forward field of view is a predetermined value greater than 0 as the closest position, The display control unit The second display area is disposed between the first display area and the center of the forward field of view, The head-up display device according to claim 1 , wherein the second display area is moved closer to the center of the forward field of view with an increase in the moving speed, with the closest position being the limit.

4. The display control unit When the moving speed is equal to or greater than a predetermined value, the second display area continues to be set to the closest position, The head-up display device according to claim 3 , wherein the first display area is set lower than the second display area by a predetermined amount.

5. The display control unit The head-up display device according to claim 3 , wherein the information is not displayed in the second display area when the moving speed is equal to or greater than a predetermined value.

6. the information displayed in the first display area is host vehicle information including the travel speed, The head-up display device according to claim 1 , wherein the information displayed in the second display area is information other than the host vehicle information.

7. The display control unit When a specific event is detected, an image corresponding to the detected event is displayed in the second display area; The head-up display device according to claim 6 , wherein if the event is not detected, no image is displayed in the second display area.

8. The head-up display device according to claim 1 , wherein the display control unit changes the positions of the first display area and the second display area in stages according to the moving speed.

9. 6. The head-up display device according to claim 1, wherein the display control unit is configured to arrange the first display area and the second display area below a center of the forward field of view.

10. a display (20) that emits image light showing the information; a mirror (30) that reflects the image light emitted by the display device toward a projection member disposed in front of the driver's seat, 6. The head-up display device according to claim 1, wherein the display control unit controls the attitude of the mirror to switch between a state in which information is displayed in the first display area and a state in which information is displayed in the second display area.

11. Further provided is a display (20) that emits image light of the information, 6. The head-up display device according to claim 1, wherein the display control unit controls the attitude of the display to switch between a state in which information is displayed in the first display area and a state in which information is displayed in the second display area.

12. A display control method implemented in a head-up display device that displays different types of information in a first display area and a second display area located in front of a driver's seat, a step (S10) of reading out display setting data from a display setting storage unit (53) in which display setting data indicating positions of the first display area and the second display area according to a moving speed is stored; A step (S11) of acquiring the moving speed based on a signal from a speed sensor; and (S15) moving the positions of both the first display area and the second display area closer to the center of the driver's forward field of view than when the moving speed is less than the predetermined value, based on the display setting data and the current moving speed, when the moving speed is equal to or greater than a predetermined value.

Images