Vehicle display device

Abstract

To provide a vehicle display device capable of performing more appropriate driving support.SOLUTION: A vehicle display device 1 comprises a display 10 that emits an image V visually recognized as a virtual image Vi by an occupant of a vehicle 100 as display light DL toward a display face 120 provided in front of the vehicle 100, that is installed in the vehicle 100; and a control part 20 for controlling the display 10. The control part 20 displays a guide G as the image V in a state where the vehicle 100 travels on a linear lane Q; can execute a processing of displaying the guide G in a superposing manner along a zone line R defining the lane Q; and changes an inclination of the guide G to the zone line R, based on a target deceleration speed f3 set according to a situation of the vehicle 100.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a display device for a vehicle. [Background technology]

[0002] For example, Patent Document 1 discloses a display control device for a vehicle equipped with a head-up display device that can superimpose illusionary images of objects that do not actually exist on the scenery visible to the driver of the vehicle through the vehicle's windshield. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-197707 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the vehicle display control device described in the above-mentioned Patent Document 1 may cause the driver to feel oppressed by superimposing an optical illusion image on the scenery, and there is a demand for more suitable driving assistance using a different display method.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide a vehicle display device that can provide more suitable driving assistance. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the vehicle display device of the present invention comprises a display device mounted on a vehicle and emitting an image as display light toward a display surface provided at the front of the vehicle, which is visible to the vehicle occupants as a virtual image, and a control unit that controls the display device, wherein the control unit is capable of executing a process to display a guide as the image when the vehicle is traveling on a straight lane and to superimpose the guide along the dividing lines that divide the lane, and is characterized in that it changes the inclination of the guide relative to the dividing lines based on a target deceleration set according to the situation of the vehicle. [Effects of the Invention]

[0007] The vehicle display device according to the present invention has an effect of being able to provide more suitable driving assistance. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a vehicle display device according to an embodiment. [Figure 2] FIG. 2 is a block diagram showing a schematic configuration of a control unit of the vehicle display device according to the embodiment. [Figure 3] FIG. 3 is a diagram for explaining each point set by the control unit of the vehicle display device according to the embodiment. [Figure 4] FIG. 4 is a diagram for explaining a process of outputting a guide displayed on a display surface of the vehicle display device according to the embodiment as an image. [Figure 5] FIG. 5 is a diagram for explaining a method for displaying a guide as an image on a display surface of the vehicle display device according to the embodiment. [Figure 6] FIG. 6 is a diagram for explaining a method for displaying a guide as an image on a display surface of the vehicle display device according to the embodiment. [Figure 7] FIG. 7 is a diagram for explaining a method for setting the amount of inclination of the guide shown in FIGS. [Figure 8] FIG. 8 is a diagram for explaining a method for setting the amount of inclination of the guide shown in FIGS. [Figure 9] FIG. 9 is a diagram for explaining a method for setting the amount of inclination of the guide shown in FIGS. [Figure 10] FIG. 10 is a flowchart illustrating an example of control by the control unit of the vehicle display device according to the embodiment. [Figure 11] FIG. 11 is a diagram for explaining a method of displaying a guide as an image on a display surface of a vehicle display device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to these embodiments. Furthermore, the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially the same.

[0010] [Embodiment] The vehicle display device 1 shown in FIG. 1 is a head-up display device that is applied to a vehicle 100 such as an automobile, and is mounted in an instrument panel provided on the dashboard of the vehicle 100.

[0011] The vehicular display device 1 of this embodiment includes a display device 10, a control unit 20, a sensor 30, and a forward monitoring unit 40. The vehicular display device 1 reflects display light DL emitted by the display device 10 toward an eyepoint (visual position) EP, which is provided at the front of the vehicle 100, allowing the image V reflected on the display surface 120 to be viewed as a virtual image Vi superimposed on the scenery visible from the eyepoint EP. The vehicular display device 1 also displays, as the virtual image Vi, a guide G visible along a lane marking R (see FIGS. 5 and 6) that defines a lane Q (see FIGS. 5 and 6) in which the vehicle 100 is traveling. The inclination of the guide G relative to the lane marking R can be changed depending on the situation of the vehicle 100 to prompt the vehicle 100 to decelerate. Therefore, the vehicular display device 1 can provide more suitable driving assistance.

[0012] The eye point EP with respect to the vehicle display device 1 is the position of the viewpoint of the driver 200, who is an occupant of the vehicle 100, and is assumed in advance as a spatial region. Furthermore, the display surface 120 on which the display light emitted by the display device 10 is reflected is described as being configured by the windshield WS provided at the front of the vehicle 100, but the form of the display surface 120 is not particularly limited, and may be, for example, a transparent or semi-transparent panel (e.g., a combiner) provided closer to the driver 200 than the windshield WS. Furthermore, the dividing line R (see FIGS. 5 and 6) is a boundary line (e.g., a white line) that defines the lane Q (see FIGS. 5 and 6), and is configured by a solid line or a dashed line drawn along the lane Q. For example, the dividing line R may be an outer roadway line, a lane boundary line, or the like. Furthermore, in the vehicle display device 1, the connection method between each component for sending and receiving power supply, control signals, various information, etc. may be, unless otherwise specified, a wired connection via wiring materials such as electric wires or optical fibers (including, for example, optical communication via optical fibers), a wireless connection such as wireless communication or contactless power supply.

[0013] The width direction of the vehicular display device 1 typically corresponds to the vehicle width direction Y of the vehicle 100 to which the vehicular display device 1 is applied. The depth direction of the vehicular display device 1 typically corresponds to the front-rear direction X of the vehicle 100 to which the vehicular display device 1 is applied (in other words, the traveling direction of the vehicle 100). The front side of the vehicular display device 1 is the side facing the driver's seat of the vehicle 100, and typically corresponds to the side viewed by the driver 200 sitting in the driver's seat. On the other hand, the back side of the vehicular display device 1 is the opposite side to the front side in the depth direction, and typically corresponds to the side housed inside the instrument panel.

[0014] In the following description, the side of the vehicle 100 moving forward in the longitudinal direction X of the vehicle 100 may be referred to as the "front" and the side of the vehicle 100 moving backward may be referred to as the "rear." In the width direction Y of the vehicle 100, the left side facing forward in the longitudinal direction X may be referred to as the "left side," and the right side facing forward in the longitudinal direction X may be referred to as the "right side." In the height direction Z of the vehicle 100, the upper side in the vertical direction may be referred to as the "upper side," and the lower side in the vertical direction may be referred to as the "lower side." Unless otherwise specified, each direction used in the following description refers to the direction when each part is assembled together. Below, each component of the vehicular display device 1 will be described in detail with reference to FIGS. 1 to 10.

[0015] The display 10 is located between the windshield WS and the eye point EP in the longitudinal direction X, and projects a virtual image Vi onto the windshield WS to enable the driver 200 to recognize the situation of the vehicle 100. As shown in FIG. 1 , the display 10 includes a housing 11, an image display device 12, and a mirror 13.

[0016] The housing 11 is made of a light-blocking material and houses the image display device 12 and the mirror 13. The top wall of the housing 11 has an opening 11a, which is closed by a transparent cover 11b that can transmit the display light DL emitted by the image display device 12.

[0017] The image display device 12 is a part that emits display light DL toward the mirror 13. The image display device 12 includes a display such as a TFT-LCD (Thin Film Transistor-Liquid Crystal Display) and a backlight that irradiates the display with light, and can display an image V on a display screen 12a of the display.

[0018] The mirror 13 is a part that reflects the display light DL emitted from the image display device 12 toward the windshield WS. The reflective surface 120a of the windshield WS that constitutes the display surface 120 is positioned opposite the driver 200 in the front-rear direction X and is inclined so as to approach the driver 200 as it moves upward in the height direction Z.

[0019] The control unit 20 is configured as a microcomputer and is a part that can control the display device 10. The control unit 20 can acquire the status of the vehicle 100 from devices mounted on the vehicle 100, a server, etc. The control unit 20 can also execute a process of generating an image V based on the acquired information and displaying the image V on the display screen 12a of the display, thereby superimposing a virtual image Vi on the scenery visible from the eye point EP. The detailed configuration of the control unit 20 will be described later.

[0020] The sensor 30 is capable of detecting the state of the vehicle 100. The sensor 30 here refers to a vehicle speed sensor that is capable of detecting at least the speed at which the vehicle 100 is traveling (hereinafter referred to as the actual speed f1). The sensor 30 can acquire information about the vehicle 100, such as the actual speed f1, by, for example, detecting the rotation speed of the output shaft or acquiring the current position of the vehicle 100 using a satellite positioning system.

[0021] The forward monitoring unit 40 can identify the location of a predetermined vehicle speed limit target point D ahead of the vehicle 100. The forward monitoring unit 40 here includes an on-board camera and communication equipment. The forward monitoring unit 40 can acquire road information and traffic information, for example, by capturing an image of the area ahead of the vehicle 100 using the on-board camera or receiving information provided from infrastructure such as a roadside unit using the communication equipment. The forward monitoring unit 40 also includes a processing unit, and the processing unit can identify, for example, the location of an obstacle ahead of the vehicle 100 or the location of a sharp curve ahead of the vehicle 100 as the location of the vehicle speed limit target point D based on the captured image and the acquired information. Note that the forward monitoring unit 40 may monitor the area ahead of the vehicle 100 based on GPS information and map information of the vehicle 100, and identify the location of the predetermined vehicle speed limit target point D ahead of the vehicle 100.

[0022] Next, the function of the control unit 20 will be described in detail with reference to FIGS.

[0023] 2, the control unit 20 conceptually includes an acquisition unit 21, a storage unit 22, a determination unit 23, a generation unit 24, and an output unit 25. First, an overview of each unit of the control unit 20 will be described with reference to FIGS. 2 and 3, and then the details of the processing executed by each unit will be described with reference to FIG. 4.

[0024] The acquisition unit 21 is a part that acquires information about the surroundings of the vehicle 100 and acquires road information and traffic information about the road on which the vehicle 100 is traveling. The acquisition unit 21 can acquire information about the vehicle speed limit target point D by, for example, acquiring information from devices such as the sensor 30 and the forward monitoring unit 40, or acquiring information from a server that manages VICS (registered trademark) (Vehicle Information and Communication System) or traffic information.

[0025] The storage unit 22 is a storage device such as a memory, and is a part that stores conditions and data necessary for various processes in the control unit 20, various programs to be executed by the control unit 20, etc. Therefore, a program for displaying the image V on the display screen 12a of the display is stored in advance in the storage unit 22. Note that the storage unit 22 may be capable of temporarily storing, for example, various pieces of information acquired by the acquisition unit 21, values ​​calculated by the determination unit 23, the image V generated based on the values, etc., and this information may be read out by the determination unit 23, the generation unit 24, the output unit 25, etc. as necessary.

[0026] The determination unit 23 is a part that determines the situation of the vehicle 100 from the information acquired by the acquisition unit 21 and calculates the amount of adjustment for the image data stored in the storage unit 32. As shown in Fig. 2, the determination unit 23 includes a speed calculation unit 23a, a distance calculation unit 23b, a setting unit 23c, a position determination unit 23d, and a calculation unit 23e.

[0027] The speed calculation unit 23a is a part that calculates an appropriate speed f2 to the vehicle speed limit target point D. The speed calculation unit 23a can calculate an appropriate speed f2 for the vehicle 100 to pass through the vehicle speed limit target point D at an appropriate speed or to stop at the vehicle speed limit target point D at an appropriate speed, based on the information about the vehicle speed limit target point D acquired by the acquisition unit 21. Note that the appropriate speed f2 may be set to a predetermined value depending on the type of the vehicle speed limit target point D.

[0028] The distance calculation unit 23b is a part that calculates the distance to the vehicle speed limit target point D. The distance calculation unit 23b can calculate the distance from the vehicle 100 to the vehicle speed limit target point D based on the information about the position of the vehicle 100 acquired by the acquisition unit 21 and the information about the position of the vehicle speed limit target point D.

[0029] The setting unit 23c is a part that sets a target deceleration f3 of the vehicle 100. The setting unit 23c can calculate the target deceleration f3 from the excess speed of the actual speed f1 of the vehicle 100 relative to the appropriate speed f2.

[0030] The position determination unit 23d is a part that determines a point at which to change the image V displayed on the windshield WS. The position determination unit 23d can set a plurality of points between the vehicle 100 and the vehicle speed limit target point D, based on the distance to the vehicle speed limit target point D calculated by the distance calculation unit 23b and the target deceleration f3 of the vehicle 100 set by the setting unit 23c.

[0031] Here, an example of each point determined by the position determination unit 23d will be described with reference to FIG. 3. For example, as shown in FIG. 3, the position determination unit 23d sets the vehicle speed limit target point D as point d, and sets three points, point a, point b, and point c, between the vehicle 100 and point d. Point a is a point where the driver 200 is prompted to decelerate the vehicle 100, and driving assistance for the driver 200 is started by displaying an image V including a guide G superimposed along the lane marking R on the windshield WS. Point b is a point where the image V is changed from a speed exceeding the actual speed f1 of the vehicle 100 relative to the appropriate speed f2, and the driver 200 is prompted to decelerate the vehicle 100. Point c is located immediately before point d, and is a point where driving assistance for the driver 200 is ended. At this time, points a, b, and c are set as the next points. First, point c is set at a point separated by a predetermined distance (first distance) from point d. The first distance here is a value that is determined in advance depending on, for example, the type of vehicle speed limit target point D, and a different value may be set depending on the type of vehicle speed limit target point D. Point b is set to a point that is a predetermined distance (second distance) away from point c. The second distance here is a value calculated depending on the target speed of vehicle 100 (the speed at which vehicle 100 will reach if it decelerates as expected), the distance to vehicle speed limit target point D, and the like. Point a is set to a point that is a predetermined distance (third distance) away from point b. The third distance here is a value calculated depending on the reaction time of driver 200 (the time from when driver 200 visually recognizes image V to when he or she starts to decelerate vehicle 100). Note that the method by which position determination unit 23d sets points a, b, and c, the intervals between each point (the lengths of the first distance, second distance, and third distance), and the like are not particularly limited and can be changed depending on the situation of vehicle 100, the situation of the road on which vehicle 100 is traveling, and the like. Furthermore, the number of intermediate points that the position determining unit 23d sets between the vehicle 100 and the vehicle speed limit target point D is not particularly limited.

[0032] 2, the explanation will be continued. The calculation unit 23e is a part that calculates the amount of inclination θ of the guide G displayed as the image V. The calculation unit 23e can calculate the amount of inclination θ of the guide G with respect to the lane marking R in accordance with the target deceleration f3 of the vehicle 100.

[0033] The generation unit 24 is a part that generates the image V to be displayed on the display screen 12a of the display. The generation unit 24 adjusts the image stored in the storage unit 22, that is, adjusts the display angle of the guide G, thereby generating the image V that suits the situation of the vehicle 100.

[0034] The output unit 35 is a part that outputs the image V to the display screen 12a of the display. The output unit 35 outputs the image V generated by the generation unit 33 to the display screen 12a of the display, thereby projecting a virtual image Vi onto the windshield WS.

[0035] Next, with reference to FIG. 4, the processes P1 to P8 until the vehicular display device 1 outputs the image V will be described in detail.

[0036] First, the acquisition unit 21 acquires the actual speed f1 of the vehicle 100 detected via the sensor 30 (process P1). The forward monitoring unit 40 acquires information about the situation ahead of the vehicle 100, such as an image of the area ahead of the vehicle 100, road information, and traffic information, and confirms the situation ahead of the vehicle 100 (process P2). The forward monitoring unit 40 then identifies the speed limit target point D based on the acquired information (process P3). The distance calculation unit 23b then calculates the distance from the current position of the vehicle 100 to the speed limit target point D based on the information about the current position of the vehicle 100 acquired by the acquisition unit 21 and the information about the position of the speed limit target point D identified by the forward monitoring unit 40 (process P4). Meanwhile, the speed calculation unit 23a calculates the appropriate speed f2 to reach the speed limit target point D based on the information about the current position of the vehicle 100 acquired by the acquisition unit 21 and the information about the position of the speed limit target point D identified by the forward monitoring unit 40 (process P5). Then, the setting unit 23c, the position determination unit 23d, and the calculation unit 23e perform various processes required for displaying the guide G based on the actual speed f1 of the vehicle 100 acquired by the acquisition unit 21, the distance to the speed limit target point D calculated by the distance calculation unit 23b, the appropriate speed f2 calculated by the speed calculation unit 23a, etc. (Process P6). That is, the setting unit 23c calculates the target deceleration f3 from the excess speed of the actual speed f1 over the appropriate speed f2 of the vehicle 100 based on the actual speed f1 of the vehicle 100 acquired by the acquisition unit 21 and the appropriate speed f2 calculated by the speed calculation unit 23a. The position determination unit 23d sets points a, b, and c between the vehicle 100 and the speed limit target point D based on the distance to the speed limit target point D calculated by the distance calculation unit 23b and the target deceleration f3 of the vehicle 100 set by the setting unit 23c. The calculation unit 23e calculates the amount of inclination θ of the guide G with respect to the lane marking R, based on the target deceleration f3 calculated from the excess speed of the actual speed f1 relative to the appropriate speed f2. The generation unit 24 then adjusts the image stored in the storage unit 22, i.e., adjusts the display angle of the guide G, based on the value calculated by the calculation unit 23e, to generate an image V that suits the situation of the vehicle 100 (process P7). The output unit 35 then outputs the image V generated by the generation unit 33 according to the situation of the vehicle 100 to the display screen 12a of the display (process P8).

[0037] [How to display the guide] Next, a method for displaying the guide G will be described in detail with reference to FIGS.

[0038] The guides G are displayed as images V on the windshield WS when the vehicle 100 is traveling on a straight lane Q, and are displayed on the inside of a pair of dividing lines R arranged along the vehicle width direction Y. As shown in FIG. 5, the pair of guides G are straight lines that extend toward a vanishing point S set in the image V. Therefore, when the pair of guides G are displayed on the windshield WS, the driver 200 has the illusion that the guides G extend along the pair of dividing lines R that appear to converge forward from the eye point EP, and recognizes the guides G as a virtual image Vi located on the lane Q on which the vehicle 100 is traveling.

[0039] Furthermore, the inclination of the guide G with respect to the lane Q is changed based on the target deceleration f3 set in accordance with the situation of the vehicle 100. More specifically, as shown in FIGS. 5 and 6, the inclination θ of the guide G with respect to the lane Q increases as the position of the vanishing point S moves downward on the windshield WS. Furthermore, as shown in FIGS. 7 to 9, when the target deceleration f3 is changed while the vehicle 100 is traveling from point b to point c, the inclination of the guide G with respect to the lane Q is changed in accordance with the magnitude of the changed target deceleration f3.

[0040] For example, when speed limit target point D is identified via the forward monitoring unit 40 or the server, and the position and situation of point d are identified, a guide G is displayed on the windshield WS when the vehicle 100 passes point a, and driving assistance is initiated for the driver 200. At this time, the inclination θ of the guide G with respect to the lane marking R is calculated to be zero. Therefore, the guide G is displayed as if it is extending parallel to the lane marking R.

[0041] Furthermore, when the vehicle 100 passes point b, the inclination θ of the guide G relative to the lane marking R is changed from zero to a predetermined value. Therefore, the guide G is displayed as if it is inclined inward from the lane marking R (toward the center of the lane Q), and the driver 200 recognizes the inclination of the guide G and recognizes that the vehicle 100 needs to decelerate. At this time, the inclination θ of the guide G relative to the lane marking R is calculated to a value that matches the magnitude of the calculated target deceleration f3. Therefore, the guide G is displayed as if it is inclined inward from the lane marking R as the target deceleration f3 increases.

[0042] Furthermore, until the vehicle 100 passes point c, the actual speed f1 of the vehicle 100 is successively measured, and the amount of inclination θ of the guide G relative to the lane marking R is successively changed according to the target deceleration f3 of the vehicle 100. Therefore, the driver 200 can visually recognize the change in the amount of inclination θ of the guide G relative to the lane marking R and grasp the change in the situation of the vehicle 100, thereby decelerating the actual speed f1 of the vehicle 100 to the appropriate speed f2.

[0043] [How to set the guide tilt amount] Next, a method for setting the tilt amount θ of the guide G will be described in detail with reference to Figs. 7 to 9. Fig. 7 is a diagram showing a method for setting the tilt amount θ of the guide G when the actual speed f1 of the vehicle 100 is decreasing in line with the target speed of the vehicle 100. Fig. 8 is a diagram showing a method for setting the tilt amount θ of the guide G when the actual speed f1 of the vehicle 100 does not decrease in line with the target speed of the vehicle 100, but decreases below the target speed of the vehicle 100. Fig. 9 is a diagram showing a method for setting the tilt amount θ of the guide G when the actual speed f1 of the vehicle 100 does not decrease in line with the target speed of the vehicle 100, but decreases above the target speed of the vehicle 100.

[0044] The vertical axis of the line graphs shown in the upper part of each figure indicates the speed of vehicle 100, with the left vertical axis indicating the actual speed f1 of vehicle 100 and the right vertical axis indicating the appropriate speed f2 of vehicle 100. The horizontal axis of the line graphs indicates the distance to speed limit target point D, and indicates the positions of points a, b, c, and d. The schematic diagrams shown in the lower part of each figure indicate the tilt θ of guide G calculated by calculation unit 23e, with a pair of lines drawn in a frame representing guide G. When the pair of lines are parallel to the vertical sides of the frame, this indicates that the tilt θ of guide G relative to lane marking R is zero, and the magnitude of the tilt of the lines relative to the vertical sides of the frame indicates the magnitude of the tilt θ of guide G relative to lane marking R.

[0045] For example, as shown in Fig. 7, when the actual speed f1 of the vehicle 100 is decreasing in line with the target speed of the vehicle 100, the deceleration rate relative to the distance to the speed limit target point D changes at a constant rate. Therefore, the target deceleration f3 of the vehicle 100 is constant, and the tilt θ of the guide G relative to the lane marking R does not change from the value calculated when the vehicle 100 passes point b. Therefore, the guide G is displayed tilted while maintaining a predetermined angle relative to the lane Q.

[0046] On the other hand, as shown in Figure 8, if the actual speed f1 of the vehicle 100 does not decrease in line with the target speed of the vehicle 100 but decreases below the target speed of the vehicle 100, that is, if the actual speed f1 of the vehicle 100 exceeds the target speed of the vehicle 100, the deceleration amount needs to be increased in order to decelerate the actual speed f1 of the vehicle 100 to an appropriate speed f2 before the vehicle 100 reaches the speed limit target point D. Therefore, the target deceleration f3 of the vehicle 100 needs to be increased, and the inclination amount θ of the guide G with respect to the lane Q needs to be increased from the value calculated when the vehicle 100 passes point b. Therefore, the guide G is displayed tilted at a larger angle with respect to the lane marking R.

[0047] 9, if the actual speed f1 of the vehicle 100 does not decrease in line with the target speed of the vehicle 100, but decreases faster than the target speed of the vehicle 100, that is, if the actual speed f1 of the vehicle 100 is lower than the target speed of the vehicle 100, it is entirely possible to decelerate the actual speed f1 of the vehicle 100 to an appropriate speed f2 before the vehicle 100 reaches the speed limit target point D. Therefore, the target deceleration f3 of the vehicle 100 needs to be reduced, and the inclination θ of the guide G with respect to the lane marking R needs to be made smaller than the value calculated when the vehicle 100 passes point b. Therefore, the guide G is displayed tilted at a smaller angle with respect to the lane marking R.

[0048] [Control unit operation] Next, the operation of the control unit 20 will be described in detail with reference to FIG.

[0049] First, the control unit 20 identifies a vehicle speed limit target point D via the forward monitoring unit 40 or the server (step S11).

[0050] Then, the control unit 20 calculates a target passing speed at the vehicle speed limit point D (step S12). For example, if the vehicle speed limit point D is a sharp curve, the control unit 20 calculates an appropriate speed f2 for the vehicle 100 to pass through the vehicle speed limit point D at an appropriate speed. Also, if the vehicle speed limit point D is an obstacle on the road, the control unit 20 calculates an appropriate speed f2 for the vehicle 100 to stop at the vehicle speed limit point D at an appropriate speed.

[0051] Then, the control unit 20 calculates the target deceleration f3 of the vehicle 100 (step S13). The control unit 20 calculates the target deceleration f3 from the excess speed of the actual speed f1 of the vehicle 100 over the appropriate speed f2, and sets points a, b, and c located between the vehicle 100 and the vehicle speed limit target point D based on the distance to the vehicle speed limit target point D and the target deceleration f3.

[0052] Then, the control unit 20 determines whether the vehicle 100 has passed point a (step S14). Point a is a point where driving assistance for the driver 200 starts by displaying a guide G on the windshield WS. If the control unit 20 determines that the vehicle 100 has not passed point a (step S14: No), it repeats step S14 until the vehicle 100 passes point a.

[0053] When the control unit 20 determines that the vehicle 100 has passed the point a (step S14: Yes), it displays the guide G on the windshield WS (step S15). At this time, the inclination θ of the guide G with respect to the lane marking R is calculated to be zero, and the guide G is displayed as extending parallel to the lane marking R.

[0054] Then, the control unit 20 determines whether the vehicle 100 has passed point b (step S16). Point b is a point where the amount of inclination θ of the guide G with respect to the lane marking R is changed, thereby prompting the driver 200 to slow down the vehicle 100. If the control unit 20 determines that the vehicle 100 has not passed point b (step S16: No), it repeats step S16 until the vehicle 100 passes point b.

[0055] Then, when the control unit 20 determines that the vehicle 100 has passed point b (step S16: Yes), it recalculates the inclination θ of the guide G relative to the lane marking R and sets the inclination θ of the guide G according to the deceleration of the vehicle 100 (step S17).

[0056] Then, the control unit 20 determines whether the vehicle 100 has passed point c (step S18). Point c is a point located immediately before point d. If the control unit 20 determines that the vehicle 100 has not passed point c (step S18: No), it checks the deceleration of the vehicle 100 and determines whether the actual speed f1 of the vehicle 100 is decreasing in line with the target speed of the vehicle 100 (step S19). If the control unit 20 determines that the actual speed f1 of the vehicle 100 is not decreasing in line with the target speed of the vehicle 100 (step S19: No), it recalculates the target deceleration f3 of the vehicle 100 (step S20). Then, the control unit 20 repeats steps S17 to S19 until the actual speed f1 of the vehicle 100 decreases in line with the target speed of the vehicle 100. If the control unit 20 determines that the actual speed f1 of the vehicle 100 is decreasing in line with the target speed of the vehicle 100 (step S19: Yes), it repeats steps S18 and S19 until the vehicle 100 passes the point c.

[0057] Then, when the control unit 20 determines that the vehicle 100 has passed the point c (step S16: Yes), it erases the guide G, thereby ending the display of the guide G on the windshield WS (step S21).

[0058] The vehicle display device 1 described above is mounted on the vehicle 100 and includes a display device 10 that emits an image V as display light DL toward a windshield WS, which serves as a display surface provided at the front of the vehicle 100, so that the occupants of the vehicle 100 can view it as a virtual image Vi, and a control unit 20 that controls the display device 10. The control unit 20 is capable of executing a process to display a guide G as image V and superimpose the guide G along the dividing line R that divides the lane Q when the vehicle 100 is traveling in a straight lane Q, and also changes the inclination of the guide G relative to the dividing line R based on a target deceleration f3 set according to the situation of the vehicle 100.

[0059] According to this configuration, the vehicular display device 1 allows the driver 200 to visually recognize the guide G, thereby enabling the driver 200 to understand the situation of the vehicle 100, and can decelerate the actual speed f1 of the vehicle 100 to the appropriate speed f2 before the vehicle 100 reaches the vehicle speed limit target point D. Therefore, more suitable driving assistance can be provided to the driver 200.

[0060] Furthermore, the vehicle display device 1 described above includes a sensor 30 capable of detecting the actual speed f1 of the vehicle 100 and a forward monitoring unit 40 that identifies a vehicle speed limit point D located ahead of the vehicle 100, and the control unit 20 sets a target deceleration f3 based on the excess speed of the actual speed f1 detected by the sensor 30 over the appropriate speed f2 for the vehicle 100 up to the vehicle speed limit point D identified by the forward monitoring unit 40. With this configuration, the target deceleration f3 is set according to the situation of the vehicle 100 while it is traveling, and the inclination of the guide G with respect to the lane marking R is changed and displayed each time, allowing the driver 200 to continuously grasp the degree of deceleration of the vehicle 100. Therefore, more suitable driving assistance can be provided to the driver 200.

[0061] Furthermore, the control unit 20 of the vehicle display device 1 described above increases the amount of inclination θ of the guide G relative to the lane marking R as the target deceleration f3 increases. With this configuration, the vehicle display device 1 allows the driver 200 to visually recognize the amount of inclination θ of the guide G relative to the lane marking R, thereby enabling the driver 200 to understand the degree of deceleration of the vehicle 100, and enables the actual speed f1 of the vehicle 100 to be reduced to the appropriate speed f2 before the vehicle 100 reaches the vehicle speed limit target point D. Therefore, more suitable driving assistance can be provided to the driver 200.

[0062] Furthermore, the guide G displayed by the vehicle display device 1 described above is displayed inside each of the lane markings R and extends toward the vanishing point S, and the larger the target deceleration f3, the lower the vanishing point S moves on the windshield WS serving as the display surface. According to this configuration, the guide G is arranged along the vehicle width direction of the vehicle 100 and is arranged symmetrically with respect to the road on which the vehicle 100 is traveling. Also, by moving the vanishing point S of the guide G downward on the display surface, the inclination amount θ of the guide G with respect to the lane markings R can be made to appear larger, allowing the driver 200 to grasp the degree of deceleration of the vehicle 100. Therefore, more suitable driving assistance can be provided to the driver 200.

[0063] [Variations] Next, a modified example of the embodiment will be described. Although the guide G has been described as being a straight line, the present invention is not limited to this.

[0064] The vehicle display device 1A according to the modified example can display a pair of guides GA on the windshield WS when the vehicle 100 is traveling on a straight lane Q. As shown in FIG. 11 , the guide GA is composed of a plurality of bright dots, and a virtual line GL connecting the bright dots extends toward a vanishing point SA set in the image. Therefore, when the guide GA is displayed on the windshield WS, the driver 200 has the illusion that the bright dots extend along a pair of lane markings R that appear to converge forward from the eye point EP, and recognizes the guide GA as a virtual image located on the lane Q on which the vehicle 100 is traveling. Note that, like the guide G described in the embodiment, the inclination of the virtual line GL with respect to the lane markings R is changed based on a target deceleration f3 set according to the situation of the vehicle 100. Therefore, the vehicle display device 1A allows the driver 200 to visually recognize the guide GA, thereby enabling the driver 200 to understand the situation of the vehicle 100 and decelerate the actual speed f1 of the vehicle 100 to an appropriate speed f2 before the vehicle 100 reaches the speed limit target point D. Therefore, more suitable driving assistance can be provided to the driver 200.

[0065] The above-described vehicle display devices 1 and 1A according to the embodiments of the present invention are not limited to the above-described embodiments, and various modifications are possible within the scope of the claims.

[0066] For example, the method for setting the target deceleration of the vehicle is not particularly limited.

[0067] Furthermore, the amount of inclination of the guide relative to the magnitude of the target deceleration of the vehicle is not particularly limited.

[0068] The guide may be superimposed on only one lane.

[0069] The vehicle display device according to this embodiment may be configured by appropriately combining the components of the above-described embodiment and modified examples. [Explanation of symbols]

[0070] 1, 1A Vehicle display device 10 Display 20 Control Unit 30 sensors 40 Forward monitoring section 100 vehicles 120 Display surface DL display light Actual speed of F1 vehicle f2 Appropriate vehicle speed f3 Vehicle target deceleration G, GA Guide S, SA guide vanishing point Q Lane R lot line V Images Vi Virtual Image WS Windshield X Anteroposterior direction Y Vehicle width direction Z height direction θ Guide tilt amount

Claims

1. a display device mounted on a vehicle and configured to emit, as display light, an image that is visually recognized as a virtual image by an occupant of the vehicle toward a display surface provided at a front portion of the vehicle; a control unit that controls the display, The control unit is capable of executing a process of displaying a guide as the image and superimposing the guide along a dividing line that divides the lane when the vehicle is traveling on a straight lane, and changing an inclination of the guide with respect to the dividing line based on a target deceleration that is set according to the situation of the vehicle. Vehicle display device.

2. a sensor capable of detecting an actual speed of the vehicle; a forward monitoring unit that identifies a vehicle speed limit target point located in front of the vehicle, the control unit sets the target deceleration based on an excess speed of the actual speed detected by the sensor relative to an appropriate speed of the vehicle up to the vehicle speed limit target point identified by the forward monitoring unit. The vehicle display device according to claim 1 .

3. The control unit increases the inclination amount of the guide with respect to the lane marking as the target deceleration increases. The vehicle display device according to claim 1 or 2.

4. The guides are displayed inside the division lines and extend toward the vanishing point, the position of the vanishing point moves downward on the display surface as the target deceleration increases. The vehicle display device according to claim 3 .

Images