WO2020066963A1

WO2020066963A1 - Display device

Info

Publication number: WO2020066963A1
Application number: PCT/JP2019/037169
Authority: WO
Inventors: 誠秦
Original assignee: 日本精機株式会社
Priority date: 2018-09-27
Filing date: 2019-09-24
Publication date: 2020-04-02
Also published as: JPWO2020066963A1; JP7338632B2

Abstract

The objective of the present invention is to display effectively a notification image assumed to have a high priority among a plurality of notification images. This display device displays a superimposed image that is visually recognized by a driver of a vehicle as a virtual image. The display device is provided with a display control means for performing display control, in two dimensions, of notification images providing notification of an object ahead of the vehicle, and a storage means for storing reference control information for determining, in accordance with an acquired distance, a display ratio which decreases as the distance to the object ahead increases. When the display control means is performing control to vary the display ratios of a first image V1 and a second image V2, serving as notification images, on the basis of the reference control information, if the display ratio of the first image V1 rises to or above a first threshold T1, the display control means executes an enlargement process to display the second image V2 with a ratio larger than a display ratio R determined on the basis of the reference control information. The enlargement process may also be executed on the condition that the display ratio of the second image V2 is less than a second threshold T2.

Description

Display device

The present disclosure relates to a display device.

As a conventional display device, Patent Literature 1 discloses an image display device that displays an image visually recognized by a viewer (mainly, a driver of the vehicle) as a virtual image overlapping a scene in front of the vehicle. The display device disclosed in Patent Literature 1 controls the relative height and the like of a notification image for notifying the front target according to the distance from the vehicle to the front target.

JP-A-2005-221633

If the technique disclosed in Patent Document 1 is used to simultaneously display a plurality of notification images as described above, similar display control is performed on each notification image according to the distance from the vehicle. However, there is room for improvement in effectively displaying one of the plurality of notification images that is assumed to have higher priority for the viewer.

The present disclosure has been made in view of the above circumstances, and has as its object to provide a display device that can effectively display an image that is assumed to have a high priority among a plurality of notification images.

In order to achieve the above object, the display device of the present disclosure includes:
A display device that displays a superimposed image visually recognized by a viewer as a virtual image overlapping a scene in front of the vehicle,
Acquisition means for acquiring a distance from the vehicle to a front object in front of the vehicle,
A display control unit that two-dimensionally controls display of a notification image that notifies a forward target in the display region of the superimposed image,
A storage unit for storing reference control information for determining a display ratio of the notification image with respect to a predetermined reference size, the display ratio being smaller as the distance is longer, in accordance with the distance acquired by the acquisition unit. And
The display control means,
As the notification image, it is possible to display a plurality of images including a first image and a second image for notifying a forward target whose distance is longer than the first image,
When the display ratio of the first image is equal to or greater than a first threshold while the display ratio of each of the first image and the second image is being changed and controlled based on the reference control information, An enlargement process for displaying the two images at a ratio larger than the display ratio determined based on the reference control information is executed.

According to the display device of the present disclosure, it is possible to effectively display, of a plurality of notification images, an image that is assumed to have a high priority.

(A) is a figure which shows the example of a mounting aspect to the vehicle of the head-up display (HUD) apparatus which concerns on one Embodiment of this invention, (b) is for demonstrating the notification image displayed in two dimensions. FIG. It is a block diagram of a display system for vehicles. It is a flowchart which shows a notification image special control process. (A) is a diagram of a function indicated by reference control information, and (b) and (c) are diagrams illustrating a specific example of a notification image. (A)-(c) is a figure for demonstrating the notification image special control processing. (A)-(c) is a figure which shows the example of transition of the notification image at the time of performing notification image special control processing. (A)-(c) is a figure for demonstrating the modification of an expansion process. (A)-(c) is a figure which shows the modification of the function which reference | standard control information shows.

A display device according to an embodiment of the present invention will be described with reference to the drawings.

The display device according to the present embodiment is the HUD (Head-Up Display) device 10 included in the vehicle display system 100 shown in FIG. As shown in FIG. 1, the HUD device 10 is provided inside the dashboard 2 of the vehicle 1 and integrates not only information on the vehicle 1 (hereinafter, referred to as vehicle information) but also information other than the vehicle information. Notify the driver 4. The vehicle information includes not only information on the vehicle 1 itself but also information on the outside of the vehicle 1 related to the operation of the vehicle 1.

The vehicle display system 100 is a system configured in the vehicle 1, and includes a HUD device 10, a peripheral information acquisition unit 40, a forward information acquisition unit 50, a line-of-sight detection unit 60, and an ECU (Electronic Control Unit) 70. And a car navigation (car navigation) device 80.

The HUD device 10 emits the display light L toward the windshield 3 as shown in FIG. The display light L reflected by the windshield 3 travels to the driver 4 side. By placing the viewpoint in the eye box E, the driver 4 can visually recognize the image represented by the display light L displayed in front of the windshield 3 as a virtual image V. Thereby, the driver 4 can observe the virtual image V in a manner superimposed on the front scenery.

The HUD device 10 displays the virtual image V two-dimensionally on a virtual plane set in front of the vehicle 1 as shown in FIG. The virtual plane is set at a position separated by a predetermined distance P (for example, about 5 to 10 m) in front of the vehicle 1 from a viewpoint position 4a when the driver 4 places the viewpoint in the eye box E. The virtual surface corresponds to a display surface of an image on the display unit 20. The virtual surface and the eye box E are set based on the size of the display surface and various mirrors in the HUD device 10 and an optical system including the windshield 3.

The HUD device 10 includes the display unit 20 and the control device 30 illustrated in FIG. 2, and a reflection unit (not illustrated).

The display unit 20 displays a superimposed image visually recognized by the driver 4 as the virtual image V under the control of the control device 30. The display unit 20 has, for example, a TFT (Thin Film Transistor) type LCD (Liquid Crystal Display) and a backlight that illuminates the LCD from behind. The backlight is composed of, for example, an LED (Light Emitting Diode). The display unit 20 generates the display light L by the LCD illuminated by the backlight displaying an image under the control of the control device 30. The generated display light L is emitted toward the windshield 3 after being reflected by the reflector. The reflector is composed of, for example, two mirrors, a folding mirror and a concave mirror. The turning mirror turns the display light L emitted from the display unit 20 back to the concave mirror. The concave mirror reflects the display light L from the folding mirror toward the windshield 3 while expanding the display light L. Thereby, the virtual image V visually recognized by the driver 4 is an enlarged image of the image displayed on the display unit 20. Note that the number of mirrors constituting the reflecting section can be arbitrarily changed according to the design.

In the following, displaying the image visually recognized by the driver 4 as the virtual image V on the display unit 20 is also referred to as “displaying a superimposed image”. Controlling the display of the display unit 20 by the control device 30 is also referred to as “performing display control of a superimposed image”. The display unit 20 is not limited to one using an LCD as long as it can display a superimposed image, and may be an OLED (Organic Light Emitting Diodes), a DMD (Digital Micro Mirror Device), an LCOS (Liquid Crystal On Silicon), or the like. A display device may be used.

The control device 30 includes a microcomputer that controls the entire operation of the HUD device 10, and includes a control unit 31, a read only memory (ROM) 32, and a random access memory (RAM) 33. The control device 30 includes a drive circuit and an input / output circuit for communicating with various systems in the vehicle 1 as a configuration (not shown).

The ROM 32 stores an operation program and various image data in advance. The RAM 33 temporarily stores various calculation results and the like. The control unit 31 includes a CPU (Central Processing Unit) 31a that executes an operation program stored in the ROM 32, and a GDC (Graphics Display Controller) 31b that executes image processing in cooperation with the CPU 31a. The GDC 31b includes, for example, a GPU (Graphics Processing Unit), an FPGA (Field-Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit). In particular, the ROM 32 stores an operation program for performing a notification image special control process described later and data of reference control information BD. The configurations of the control device 30 and the control unit 31 are arbitrary as long as the functions described below are satisfied.

The control unit 31 controls the driving of the display unit 20. For example, the control unit 31 drives and controls the backlight of the display unit 20 with the CPU 31a, and drives and controls the LCD of the display unit 20 with the GDC 31b that operates in cooperation with the CPU 31a.

The CPU 31a of the control unit 31 controls the superimposed image based on various image data stored in the ROM 32 in cooperation with the GDC 31b. The GDC 31b determines the control content of the display operation of the display unit 20 based on the display control command from the CPU 31a. The GDC 31b reads, from the ROM 32, image part data necessary to compose one screen to be displayed on the display unit 20, and transfers the image part data to the RAM 33. The GDC 31b uses the RAM 33 to create picture data for one screen based on image part data and various image data received from the outside of the HUD device 10 by communication. When the GDC 31b completes the picture data for one screen in the RAM 33, the GDC 31b transfers the picture data to the display unit 20 in synchronization with the image update timing. Thus, a superimposed image visually recognized by the driver 4 as the virtual image V is displayed on the display unit 20. In addition, a layer is assigned in advance to each image constituting the image visually recognized as the virtual image V, and the control unit 31 can perform individual display control of each image.

(5) The control unit 31 controls the display position and size of the content image in the display area of the virtual image V. In particular, in this embodiment, the control unit 31 controls the size of a notification image, which will be described later, included in the content image according to the distance from the vehicle 1 to the front target to which the notification image notifies. The function and control of the notification image will be described later in detail. Note that the dotted frame indicated by the virtual image V in FIG. 1B and FIGS. 6A to 6C indicates the display area of the virtual image V, and the content image is visually recognized as the virtual image V in the display area. Image to be displayed. This is equivalent to displaying the content image in the display area of the superimposed image on the display unit 20 that displays the superimposed image visually recognized by the driver 4 as the virtual image V.

The control unit 31 communicates with each of the peripheral information acquisition unit 40, the forward information acquisition unit 50, the line-of-sight detection unit 60, the ECU 70, and the car navigation device 80. As the communication, for example, communication systems such as CAN (Controller Area Network), Ethernet, MOST (Media Oriented Systems Transport), and LVDS (Low Voltage Differential Signaling) can be applied.

The peripheral information acquisition unit 40 acquires information on the periphery (external) of the vehicle 1 and performs communication between the vehicle 1 and a wireless network (V2N: Vehicle To Cellular Network) and communication between the vehicle 1 and another vehicle (V2V). : Vehicle To Vehicle), communication between the vehicle 1 and a pedestrian (V2P: Vehicle To Pedestrian), and communication between the vehicle 1 and a roadside infrastructure (V2I: Vehicle To roadside Infrastructure). That is, the peripheral information acquisition unit 40 enables communication by V2X (Vehicle @ To \ Everything) between the vehicle 1 and the outside of the vehicle 1.

For example, (i) the peripheral information acquisition unit 40 includes a communication module that can directly access a WAN (Wide Area Network), an external device (such as a mobile router) that can access the WAN, and an access point of a public wireless LAN (Local Area Network). It has a communication module for communication and performs Internet communication. The peripheral information acquisition unit 40 includes a GPS controller that calculates the position of the vehicle 1 based on a GPS (Global Positioning System) signal received from an artificial satellite or the like. With these configurations, communication by V2N is enabled. (Ii) The peripheral information acquisition unit 40 includes a wireless communication module that conforms to a predetermined wireless communication standard, and performs communication using V2V or V2P. (Iii) The peripheral information acquisition unit 40 has a communication device that wirelessly communicates with the roadside infrastructure, and is installed as an infrastructure from a base station of a driving safety support system (DSSS: Driving Safety Support Systems), for example. Object information and traffic information around the vehicle 1 are acquired via the roadside apparatus. Thereby, communication by V2I becomes possible.

In this embodiment, the peripheral information acquisition unit 40 acquires object information indicating the position, size, attributes, and the like of various objects such as vehicles, traffic lights, and pedestrians outside the vehicle 1 by V2I, and controls the control unit 31. To supply. Note that the object information is not limited to V2I, and may be obtained by any communication among V2X. Further, the peripheral information acquisition unit 40 acquires traffic information including the position and shape of the peripheral road of the vehicle 1 by V2I, and supplies the traffic information to the control unit 31. Further, the control unit 31 calculates the position of the vehicle 1 based on information from the GPS controller of the surrounding information acquisition unit 40. These various types of information include information indicating the content of the forward target, which will be described later, and information for the control unit 31 to specify the distance from the vehicle 1 to the forward target.

The forward information acquisition unit 50 is a ranging camera such as a stereo camera that captures an image of the scenery ahead of the vehicle 1 or a LIDAR (Laser Imaging Detection And Ranging) that measures the distance from the vehicle 1 to an object located in front of the vehicle 1. It comprises a sensor, a sonar for detecting an object located in front of the vehicle 1, an ultrasonic sensor, a millimeter wave radar, and the like.

In this embodiment, the forward information acquisition unit 50 transmits the forward image data indicating the front landscape image captured by the stereo camera, the data indicating the distance to the object measured by the distance measurement sensor, and other detection data. Send to These various types of information include information indicating the content of the forward target, which will be described later, and information for the control unit 31 to specify the distance from the vehicle 1 to the forward target.

The line-of-sight detection unit 60 includes, for example, an imaging unit (for example, a stereo camera) that images the face of the driver 4 and generates image data, and an image processing unit that performs image processing of the image data. Is detected. For example, the line-of-sight detection unit 60 detects the line-of-sight direction of the driver 4 by a known image analysis method such as a pattern matching method, and transmits detection data indicating a detection result to the CPU 31a.

The CPU 31a refers to table data in which the line of sight direction and the position of the viewing target are stored in advance in the ROM 32 and specifies the target that the driver 4 is currently viewing. The gaze direction may be detected based on, for example, one of the eyes of the driver 4, or may be detected as the center of gravity of the eyes. As long as the CPU 31a can identify the target visually recognized by the driver 4, the detection data is arbitrary. In addition, the line-of-sight detection unit 60 may detect the direction of the face of the driver 4 by a known image analysis method and use the data as detection data. In this case, the CPU 31a refers to the table data in which the face direction and the position of the visual recognition target are stored in advance in the ROM 32, and specifies the target that the driver 4 is currently viewing. . Instead of using the table data, the position of the visual recognition target may be obtained from the line of sight by a mathematical formula. The data indicating the mathematical expression may be stored in the ROM 32 in advance.

The gaze detection unit 60 may be an imaging unit, an electro-oculogram sensor, or a motion sensor mounted on a wearable device worn by the driver 4 on the head. The direction of the line of sight and the direction of the face can be detected in the same manner as described above, based on the image data obtained by the imaging means. Further, the electro-oculography sensor detects the gaze direction of the driver 4 based on the measured electro-oculography. The motion sensor includes, for example, one or a combination of an acceleration sensor, a gyro sensor, and a geomagnetic sensor, and detects the direction of the face of the driver 4.

The CPU 31a may be configured to detect the gaze direction and the face direction of the driver 4 based on signals from the imaging unit and various sensors. As long as the CPU 31a can specify the target visually recognized by the driver 4, the detection method and detection configuration of the driver's 4 gaze direction and face direction are arbitrary.

The ECU 70 controls each unit of the vehicle 1, and transmits, for example, vehicle speed information indicating the current vehicle speed of the vehicle 1 to the CPU 31a. Note that the CPU 31a may acquire vehicle speed information from a vehicle speed sensor. In addition, the ECU 70 transmits to the CPU 31a measurement amounts such as the engine speed, warning information of the vehicle 1 itself (such as low fuel and abnormal engine oil pressure), and other vehicle information. Based on the information acquired from the ECU 70, the CPU 31a can also display an image indicating the vehicle speed, the engine speed, various warnings, and the like on the display unit 20 via the GDC 31b. That is, in the display area of the virtual image V, an image indicating vehicle information other than a notification image described later can also be displayed.

The car navigation device 80 includes a GPS controller that calculates the position of the vehicle 1 based on a GPS signal received from an artificial satellite or the like. The car navigation device 80 has a storage unit for storing map data, reads out map data near the current position from the storage unit based on position information from the GPS controller, and displays a guide route to a destination set by the user. decide. Then, the car navigation device 80 outputs information on the current position of the vehicle 1 and the determined guidance route to the control unit 31. In addition, the car navigation device 80 outputs information indicating the name and type of the facility in front of the vehicle 1 and the distance between the facility and the vehicle 1 to the control unit 31 by referring to the map data. The map data includes road shape information (lane, road width, number of lanes, intersections, curves, branch roads, etc.), regulation information on road signs such as speed limits, and information on each lane when there are multiple lanes. Various information is associated with the position data. The car navigation device 80 outputs these various types of information to the control unit 31. These various types of information include information indicating the content of the forward target, which will be described later, and information for the control unit 31 to specify the distance from the vehicle 1 to the forward target. Note that the car navigation device 80 is not limited to the one mounted on the vehicle 1, and performs wired or wireless communication with the control unit 31 and has a car navigation function such as a mobile terminal (smartphone, tablet PC (Personal Computer), etc.). ).

(Function and control of notification image)
Here, the function and control of the notification image will be described. The notification image displayed in the display area of the virtual image V is an image for notifying the front target in front of the vehicle 1. The forward object includes not only an actual object (hereinafter, referred to as an actual object) but also information in a scene in front of the vehicle 1. The notification image can be roughly classified into a display in an “emphasis mode” for emphasizing a real object and a display in a “visualization mode” for visualizing information that is not visually recognized in the scenery ahead.

The notification image of the emphasis mode is displayed at a position corresponding to a real object such as a preceding vehicle, a pedestrian, a road sign, or a building existing in front of the vehicle 1. The notification image of the emphasis mode is displayed, for example, superimposed on the real object or in the vicinity of the real object, and notifies the existence of the real object by emphasizing it. That is, the “position corresponding to the real object” as the display position of the notification image in the emphasized mode is not limited to a position that is superimposed on the real object and visually recognized, and may be a position near the real object. The emphasis mode is arbitrary as long as it does not hinder the visual recognition of the real object.

The notification image of the visualization mode is, for example, an image imitating a road sign for notifying various information at the place where the road sign is not installed, or the driver 4 preset in the car navigation device 80 or the like, The image includes a POI (Point of Interest) such as a destination and a facility. Here, the road sign includes all kinds of information such as a guide sign, a warning sign, a regulation sign, and an instruction sign. That is, the notification image that can be displayed in this embodiment includes an image imitating a road sign. Here, an example of a notification image in a visualization mode imitating a road sign is shown in FIGS. 4B and 4C. The notification image shown in FIG. 4B is an image imitating a guide sign. The notification image shown in FIG. 4C is an image simulating a regulation sign indicating a speed limit.

The control unit 31 notifies the notification so that the display size of the notification image decreases as the distance X from the vehicle 1 to the forward target increases (in other words, the display size of the notification image increases as the distance X decreases). Performs image display control. Thereby, a pseudo perspective can be given to the notification image.

The control unit 31 acquires the distance X to the forward target based on information transmitted from at least one of the peripheral information acquisition unit 40, the forward information acquisition unit 50, and the car navigation device 80 (hereinafter, referred to as a specific configuration). . Note that the control unit 31 may obtain information indicating the distance X from the specific configuration, or may obtain coordinate information of a forward target from the specific configuration, and calculate the distance X based on the coordinate information. In particular, the distance X to the forward target, which is the notification target of the notification image in the visualization mode, is determined by the representative position of the forward target specified based on information from the peripheral information acquisition unit 40 or the car navigation device 80 (for example, the start of the restricted section). (A position or a position predetermined as a position suitable for road guidance) can be obtained or calculated.

The control unit 31 determines the display ratio Y based on the obtainable distance X and the reference control information BD as described above, and displays the notification image at the determined display ratio Y. The reference control information BD is data of a function F (formula) indicating the relationship between the distance X and the display ratio Y. The function F is, for example, an inverse proportion that can be represented by Y = α / X, as shown in FIG. The constant α is determined by, for example, a predetermined distance P from the virtual plane to the eye box E and a reference size described later.

Magnification Y is a display ratio of the notification image for the reference size, the size to be displayed on the virtual surface and S, if a reference size as S _0, is represented by S / S _0. Reference size is stored in advance in the ROM32 as the size of the broadcast image in the predetermined distance X _0. Incidentally, how to set the predetermined distance X ₀ is arbitrary.

The reference size is predetermined in accordance with the type of the notification image. FIG. 4B shows a notification image of a reference size having a horizontal length of A and a vertical length of B as a rectangular notification image. FIG. 4C shows a circular notification image having a reference size with a horizontal length of C and a vertical length of D. Note that if the notification image is a perfect circle, C = D, and if the notification image is an ellipse, C ≠ D. The length referred to here can be defined, for example, in pixels.

For example, when the display ratio Y determined by the control unit 31 is “2”, the notification image shown in FIG. 4B has a horizontal length of 2A, a vertical length of 2B, and a standard size. It will be displayed enlarged. When the display ratio Y determined by the control unit 31 is “１／”, the notification image shown in FIG. 4C has a size of 1 / 2C in width and 1 / 2D in height, The image is displayed after being reduced from the reference size. As described above, enlargement or reduction of the notification image is performed while maintaining the aspect ratio of the notification image of the reference size. Note that the shape of the notification image is not limited to a rectangle or a circle, but may be another shape such as a triangle or a polygon, and the concept of enlargement or reduction is the same for other shapes. The configuration of the notification image is arbitrary as long as information on the forward target can be notified, and may be, for example, a character, a symbol, a graphic, an icon, or a combination thereof.

As shown in FIG. 1B, the virtual image V is displayed two-dimensionally on the virtual plane, so that the notification image displayed in the display area of the virtual image V is also displayed two-dimensionally. For example, the virtual surface is set facing the driver 4, and the notification image is also displayed facing the driver 4. By setting the display surface of the display unit 20 (the display surface of the LCD or the screen when DMD or LCOS is used) at an angle, the virtual surface is set to be inclined forward with respect to the vertical direction of the vehicle 1. May be. Even in such a case, the notification image can be viewed directly facing the driver 4 in consideration of the projection from the virtual plane set obliquely to the facing plane. Therefore, even when the virtual plane of the virtual image V is set obliquely, the concept of enlarging or reducing the notification image visually recognized by the driver 4 is the same as described above.

As described above, the control unit 31 controls the display of the notification image. When there are a plurality of forward targets, the control unit 31 can display a plurality of notification images within the same period (simultaneously).
When the display ratio of the notification image determined based on the reference control information BD becomes equal to or more than the predetermined value TM, the notification image may be deleted. By doing so, when the vehicle 1 approaches a predetermined forward target, it is possible to avoid that the notification image for notifying the forward target is displayed too large and the driver 4 is troublesome. The predetermined value TM will be described later.

Here, of the plurality of notification images, an image that notifies a forward target whose distance X from the vehicle 1 is the closest is referred to as a first image V1, and an image that notifies a forward object whose distance X is farther than the first image V1 is a first image V1. A second image V2, and a third image V3 that notifies a forward target whose distance X is farther than the second image V2.
As shown in FIG. 1B and FIG. 6A, the plurality of notification images are subjected to the control based on the reference control information BD (hereinafter, referred to as normal control) in the order from the largest display size to the smallest display size. One image V1, the second image V2, and the third image V3 are obtained. As the vehicle 1 travels forward, the distance X to the forward target gradually decreases, and the display size of the first image V1, the second image V2, and the third image V3 gradually increases. This will be described with reference to a function F shown in FIG. 5A. That is, a point on the curve indicated by the function F indicating each of the first image V1, the second image V2, and the third image V3 moves to the left. Corresponding to
However, with only the control by the normal control, the second image V2 displayed following the first image V1 may be too small to be visually recognized depending on the distance X. In order to solve this, the control unit 31 executes a notification image special control process shown in FIG.

When the control unit 31 specifies a plurality of forward targets during the normal control based on the reference control information BD, the control unit 31 performs display control of a plurality of notification images for notifying the forward targets. Then, the control unit 31 repeatedly executes the notification image special control process at a predetermined control cycle during a period in which a plurality of notification images are displayed. That is, the notification image special control process is executed at least during a period in which both the first image V1 and the second image V2 are displayed.

(Broadcast image special control processing)
First, the control unit 31 determines whether the display ratio of the first image V1 is equal to or more than the first threshold T1 (Step S1). The first threshold value T1 is predetermined as a display ratio corresponding to the distance X when the forward target is sufficiently close to the vehicle 1 and the forward target is expected to pass soon, and is stored in the ROM 32. .

If the display ratio of the first image V1 is equal to or greater than the first threshold value T1 (Step S1; Yes), the control unit 31 executes the process of Step S2. On the other hand, when the display ratio of the first image V1 is less than the first threshold value T1 (Step S1; No), the control unit 31 causes the driver 4 to display the first image V1 based on the line-of-sight information acquired from the line-of-sight detection unit 60. It is determined whether or not is visually recognized (step S3).

When the driver 4 does not visually recognize the first image V1 (Step S3; No), the control unit 31 terminates the notification image special control process, while the driver 4 visually recognizes the first image V1. In this case (Step S3; Yes), the processing of Step S2 is executed. By doing so, even if the display ratio of the first image V1 is less than the first threshold value T1, it is assumed that the driver 4 has recognized the first image V1 and the importance of the first image V1 has already been reduced. In this case, an enlarging process for ensuring the visibility of the second image V2 can be executed as described later.

In step S2, the control unit 31 determines whether the erasing condition of the first image V1 is satisfied. For example, when the display ratio of the first image V1 is equal to or more than the predetermined value TM, the control unit 31 determines that the erasing condition is satisfied (Step S2; Yes), and sets the first image V1 within the display range of the virtual image V. (Step S4). The predetermined value TM is, for example, predetermined as a value larger than the first threshold value T1, and is stored in the ROM 32. After execution of step S4 or when the erasing condition of the first image V1 is not satisfied (step S2; No), the control unit 31 executes the process of step S5.

In step S5, the control unit 31 determines whether the display ratio of the second image V2 is less than the second threshold value T2. The second threshold value T2 is a value smaller than the first threshold value T1, and a distance in a case where it is assumed that the front object is far from the vehicle 1 and the second image V2 indicating the front object becomes difficult for the driver 4 to visually recognize. The display ratio corresponding to X is predetermined and stored in the ROM 32.

When the display ratio of the second image V2 is equal to or greater than the second threshold T2 (Step S5; No), the control unit 31 ends the notification image special control process. In this case, the second image V2 is displayed according to the normal control based on the reference control information BD, that is, the function F.
On the other hand, when the display ratio of the second image V2 is less than the second threshold value T2 (Step S5; Yes), the control unit 31 executes an enlargement process on the second image V2 (Step S6).

制御 In the enlargement process in step S6, the control unit 31 displays the second image V2 at a ratio larger than the display ratio R (see FIGS. 5B and 5C) determined based on the reference control information BD. In the enlarging process, for example, as shown in FIG. 5C, the control unit 31 sets a proportional constant to a function F (Y = α / X) based on the reference control information BD such that the display ratio Y increases by a predetermined amount γ. The display control of the second image V2 is performed using the special function Fs (Y = (α + γ) / X) that has been increased.

6 (a) and 6 (b) show an example of image transition when the enlargement process is executed. When the enlargement process is performed, the second image V2 displayed by the normal control as shown in FIG. 6A is enlarged as shown in FIG. 6B. By executing the enlargement process on the second image V2 in this manner, the notification target of the first image V1 will soon pass, and the second image V2 that is assumed to have a higher importance of notification than the first image V1 will be displayed. It can be displayed easily.

In addition, when executing the enlargement process, the control unit 31 may display the second image V2 above the driver 4 as compared to before the execution. In this case, the driver 4 can be provided with a view necessary for driving. The control of moving the second image V2 upward and displaying the image together with the enlargement processing as described above is particularly useful when the second image V2 is a notification image in a visualization mode imitating a road sign. This is because the normal road sign is displayed above the front road surface, so that the driver 4 can visually recognize the second image V2 as if he / she were looking at an actual road sign.

In addition, when displaying the third image V3 that notifies the forward target whose distance X is farther than the second image V2, the control unit 31 performs the enlargement process on the second image V2. However, the display of the third image V3 is continued under the control based on the reference control information BD. As a result, the second image V2 becomes relatively more prominent than the third image V3, and the second image V2 having a higher importance of notification than the third image V3 can be effectively displayed in the latest. . If there are four or more notification images at the time of performing the notification image special control process, the notification image displayed smaller than the third image V3 (that is, the distance X is longer than the notification target of the third image V3). The display based on the control based on the reference control information BD is also continued for the image notifying the forward target.

In step S1 or S2, the control unit 31 determines whether or not a part of the first image V1 is out of the display area of the virtual image V, as shown in FIG. If so, and if it is determined Yes in step S5, the enlargement process may be executed. Even in this case, the notification target of the first image V1 will soon pass, and the second image V2, which is assumed to have a higher importance of notification than the first image V1, can be displayed in an easily recognizable manner.

Next, the control unit 31 determines whether or not a predetermined period (for example, several seconds) has elapsed from the start of the execution of the enlargement process (step S7). When the predetermined period has elapsed (Step S7; Yes), the control unit 31 executes a return process of returning the display control of the second image V2 to the control based on the reference control information BD (Step S8), and outputs the notification image. The special control processing ends.

FIGS. 6B to 6C show an example of image transition when the return process is executed. When the return process is executed, the second image V2, which has been enlarged and displayed as shown in FIG. 6B, is displayed by control based on the reference control information BD as shown in FIG. 6C.

FIG. 6C shows an example in which the display ratio changes in the Y direction when the enlargement process or the return process is executed. However, in order to suppress a sudden change in the size of the second image V2, the display ratio is gradually reduced. May be changed. As described above, when the display ratio is gradually changed, the point (X, Y) indicating the second image V2 moves from the function F to the special function Fs in a diagonally upper left direction in the Y direction when the enlargement processing is performed. At the time of execution of the return process, the special function Fs moves to the function F obliquely downward and leftward in the Y direction.

If the predetermined period has not elapsed from the start of the execution of the enlargement process (Step S7; No), the control unit 31 uses the line-of-sight information acquired from the line-of-sight detection unit 60 to display the second image V2 displayed by the driver 4 in an enlarged display. It is determined whether or not is visually recognized (step S9).

When the driver 4 is not visually recognizing the second image V2 (Step S9; No), the control unit 31 terminates the notification image special control process, while the driver 4 is visually recognizing the second image V2. In this case (Step S9; Yes), the return process of Step S8 is executed. By doing so, when it is assumed that the driver 4 has recognized the second image V2 during the enlarged display, the display control of the second image V2 can be returned to the control based on the reference control information BD, For the driver 4, it is possible to suppress the second image V <b> 2 whose importance has already been reduced from continuing to be enlarged. This is the end of the description of the notification image special control processing.

In addition, the present invention is not limited by the above embodiments and drawings. Modifications (including deletion of components) can be made as appropriate without changing the gist of the present invention. An example of the modification will be described below.

In the enlargement processing described above, an example in which the second image V2 is controlled based on the special function Fs has been described, but the present invention is not limited to this. For example, as shown in FIG. 7A, when the enlargement process is performed, the display of the second image V2 may be controlled at a constant display ratio Y independent of the distance X.
However, when the display control of the second image V2 is performed at a constant display ratio Y during the execution of the enlargement process, the point (X, Y) representing the second image V2 is ideally restored as shown in FIG. Is rarely located on the function F at the start of the operation. Therefore, as shown in FIG. 7B, from the start point of the return process, the return function passes through the point representing the second image V2 at the start point, and the proportionality constant of the function F is reduced by a predetermined value. The display control of the second image V2 may be performed using Fb. The control using the return function Fb can be said to be an example of control of the display ratio of the second image V2 based on the reference control information BD. Further, as shown in FIG. 7C, the display ratio, which is a constant value until the enlargement process is executed and the return process starts, may be changed based on the function F from the start time. Good. Also in these modified examples, the display ratio may be gradually changed at the time of executing the enlargement processing or the return processing as described above.

As shown in FIG. 7A, when the second image V2 is controlled to be displayed at a constant display ratio Y independent of the distance X at the time of executing the enlargement process, the constant display ratio Y intersects with the function F. The return process may be started at the point of time. That is, the predetermined period from when the enlargement process is performed on the second image V2 to when the return process is started may not be a predetermined period.

In the above, an example has been described in which the special function Fs is obtained by increasing the proportional constant of the function F, and the return function Fb is obtained by decreasing the proportional constant of the function F. However, the present invention is not limited to this. For example, the special function Fs may be a function obtained by translating the function F (Y = α / X) in the Y direction by + δs (δs is a constant) (Y = α / X + δs). The return function Fb may be a function obtained by translating the function F (Y = α / X) in the Y direction by −δb (δb is a constant) (Y = α / X−δb).

Further, in the above, an example in which the function F is inversely proportional has been described. However, the function F is approximated by a linear function (Y = αX + β) having a constant slope as shown in FIG. ) May be indicated.

In the above description, the function F may be an algebraic function or an elementary function including a polynomial function, and may represent a curve. Further, the function F may be configured by a plurality of linear functions having different slopes. For example, as shown in FIG. 8B, the function F may represent a curve in which the larger the distance X, the larger the display ratio Y than the direct proportional relationship. Further, as shown in FIG. 8B, the function F is represented by a plurality of straight lines, and the plurality of straight lines have a gentler gradient when the distance is equal to or longer than a predetermined distance X than when the distance is shorter than the distance X. May be included. The examples of the function F shown in FIGS. 8B and 8C are useful when it is difficult to visually recognize a distant landscape during rain or dense fog, or when the sunshine is so strong that a notification image is difficult to see.

In the above description, an example is shown in which the reference control information BD is data representing a mathematical expression of the function F. However, the reference control information BD is a table configured to determine the display ratio Y corresponding to the acquired distance X. It may be data. That is, the reference control information BD can determine the display ratio Y that decreases as the distance X increases (in other words, the display ratio Y increases as the distance X decreases) in accordance with the acquired distance X. , Or may be table data, and the configuration is arbitrary.

In the above, when the display ratio of the first image V1 is equal to or more than the predetermined value TM, the control unit 31 determines that the erasing condition is satisfied (step S2 of the notification image special control process illustrated in FIG. 3). ) Is not limited to this. For example, when the target visually recognized by the driver 4 is the first image V1, the control unit 31 determines that the erasing condition is satisfied (step S2 of the notification image special control process illustrated in FIG. 3; Yes). May be.

In addition, as long as the second image V2 can be displayed effectively, it goes without saying that in the notification image special control processing described above, some processing can be omitted, and predetermined processing can be changed or added. . For example, in the notification image special control process, at least one of step S3, steps S2 and S4, and step S9 may be omitted. Further, the process of step S5 may be omitted in the notification image special control process.

The projection target of the display light L is not limited to the windshield 3, but may be a combiner including a plate-shaped half mirror, a hologram element, and the like. The display device that executes the above-described notification image special control process is not limited to the HUD device 10. The display device may be configured as a head mounted display (HMD: Head Mounted Display) mounted on the head of the driver 4 of the vehicle 1. Then, in the image displayed by the HMD as a virtual image, the display control of the notification image may be executed by the same method as described above. That is, the display device is not limited to the display device mounted on the vehicle 1 and may be any display device used in the vehicle 1.

The display device described above (for example, the HUD device 10) displays a superimposed image visually recognized by the driver 4 (an example of a viewer) as a virtual image V overlapping a scene in front of the vehicle 1.
The HUD device 10 includes an acquisition unit (for example, the control unit 31) for acquiring a distance X from the vehicle 1 to a front target in front of the vehicle 1, and a notification image for notifying the front target in the display region of the superimposed image. A display control unit (for example, the control unit 31 or the display unit 20) that performs display control in two dimensions and obtains a display ratio Y of the notification image with respect to a predetermined reference size, which becomes smaller as the distance X becomes longer. Storage means (for example, ROM 32) for storing reference control information BD for determining according to the distance X acquired by the means.
The display control means can display a plurality of images including the first image V1 and the second image V2 for notifying a forward target whose distance X is longer than the first image V1. Further, the display control means controls the display ratio Y of the first image V1 to be equal to the first threshold value T1 when the display ratio Y of each of the first image V1 and the second image V2 is controlled to be changed based on the reference control information BD. In the case described above, it is determined whether or not the display ratio Y of the second image V2 is smaller than the second threshold T2 which is smaller than the first threshold T1. Then, when the display ratio Y of the second image V2 is equal to or greater than the second threshold value T2, the display control unit controls the display ratio Y of the second image V2 based on the reference control information BD. When the display ratio Y is less than the second threshold T2, the enlargement process of displaying the second image V2 at a ratio larger than the display ratio R (see FIG. 5C) determined based on the reference control information BD. Execute
By executing the enlargement process on the second image V2 in this manner, as described above, the notification target of the first image V1 is likely to pass soon, and the importance of the notification becomes higher than that of the first image V1. The second image V2 can be displayed so as to be easily recognized. That is, according to the display device described above, it is possible to effectively display an image that is assumed to have a high priority among a plurality of notification images.

In the above description, well-known technical items are not described in order to facilitate understanding of the present disclosure.

REFERENCE SIGNS LIST 100 vehicle display system 10 HUD device 20 display unit 30 control device 31 control unit (31a CPU, 31b GDC)
32 ROM, 33 RAM
40: peripheral information acquisition unit 50: forward information acquisition unit 60: gaze detection unit 70: ECU
80: Car navigation device BD: Reference control information F: Function, Fs: Special function, Fb: Return function T1: First threshold, T2: Second threshold, TM: Predetermined value V: Virtual image V1: First image, V2 ... 2nd image, V3 ... 3rd image 1 ... vehicle, 2 ... dashboard, 3 ... windshield, 4 ... driver E ... eye box, L ... display light

Claims

A display device that displays a superimposed image visually recognized by a viewer as a virtual image overlapping a scene in front of the vehicle,
Acquisition means for acquiring a distance from the vehicle to a front object in front of the vehicle,
A display control unit that two-dimensionally controls display of a notification image that notifies a forward target in the display region of the superimposed image,
A storage unit for storing reference control information for determining a display ratio of the notification image with respect to a predetermined reference size, the display ratio being smaller as the distance is longer, in accordance with the distance acquired by the acquisition unit. And
The display control means,
As the notification image, it is possible to display a plurality of images including a first image and a second image for notifying a forward target whose distance is longer than the first image,
When the display ratio of the first image is equal to or greater than a first threshold while the display ratio of each of the first image and the second image is being changed and controlled based on the reference control information, Executing an enlargement process of displaying the two images at a ratio larger than the display ratio determined based on the reference control information;
Display device.
The display control means is capable of erasing the first image when a display ratio of the first image that has been changed and controlled based on the reference control information becomes equal to or greater than a predetermined value larger than the first threshold. Yes,
When the display ratio of the first image is equal to or greater than the first threshold, or when the first image is deleted, the enlargement process is performed.
The display device according to claim 1.
The enlargement process is performed on condition that a display ratio of the second image is less than a second threshold smaller than the first threshold.
When the display ratio of the second image is equal to or more than the second threshold and the enlargement process is not performed, the display control unit controls the display ratio of the second image based on the reference control information.
The display device according to claim 1.
The plurality of images include a third image that reports a forward target whose distance is longer than the second image,
The display control unit controls the display ratio of the third image based on the reference control information even when the enlargement process is performed.
The display device according to claim 1.
The display control means, when performing the enlargement processing, displays the second image above the viewer before the execution, as viewed from the viewer.
The display device according to claim 1.
The display control means returns the second image to a display ratio determined based on the reference control information after a predetermined period has elapsed after executing the enlargement processing.
The display device according to claim 1.
The display control unit, based on line-of-sight information indicating the line-of-sight direction of the viewer acquired from the line-of-sight detection unit, specifies that the viewer has visually recognized the second image on which the enlargement process has been performed, Returning the two images to the display ratio determined based on the reference control information;
The display device according to claim 1.
The notification image displayable by the display control means includes an image imitating a road sign,
The display device according to claim 1.