Lane display device

Abstract

The lane display device comprises a curve information acquisition unit for acquiring surrounding curve information of the vehicle, a display control unit for displaying a curve lane image according to the shape of the surrounding curve lane of the vehicle on a display, and a vehicle speed acquisition unit for acquiring the vehicle speed of the vehicle. The display control unit reduces the degree of curvature of the curve lane image displayed on the display when the vehicle speed is slow compared to when the vehicle speed is fast.

Description

Technology Field

[0001] The present disclosure relates to a lane marking device. Background Technology

[0002] There is a device mounted on a vehicle that displays the surrounding conditions of the vehicle. Such a device is described, for example, in Patent Document 1. The device described in Patent Document 1 displays the vehicle's front lane and structures on a display based on map information. In addition, similar configurations are described in Patent Documents 2 and 3. Prior art literature

[0003] Japanese Patent Publication No. 2013-170875, Japanese Patent Publication No. 2023-164171, Japanese Patent Publication No. Hei 10-143794 The problem to be solved

[0004] For example, in a device that displays the surrounding conditions of a vehicle, if the lane ahead is curved, an image of the curved lane corresponding to the degree of curvature is displayed on the display. However, even if the lane shape corresponding to the actual degree of curvature is displayed, depending on the vehicle's speed, the driver may feel a sense of discrepancy between the actual lane curve shape (degree of curvature) and the lane curve shape displayed on the screen when looking at the display.

[0005] For this reason, the present disclosure provides a lane display device capable of displaying a curve lane image while suppressing the driver from feeling uncomfortable. means of solving the problem

[0006] A lane display device according to one embodiment of the present disclosure is [1] “a lane display device comprising a curve information acquisition unit that acquires curve information including the shape of the curve lane around a vehicle, a display control unit that displays a curve lane image according to the shape of the curve lane around the vehicle based on the acquired curve information, and a vehicle speed acquisition unit that acquires the vehicle speed of the vehicle, wherein the display control unit reduces the degree of curvature of the curve lane image displayed on the display when the vehicle speed is slow compared to when the vehicle speed is fast.”

[0007] For example, drivers of their own vehicles tend to drive while looking at road conditions closer to their vehicle when the vehicle speed is slow compared to when the vehicle speed is fast. Additionally, even when viewing the same curve lane, drivers tend to perceive the curvature as greater when looking far away and smaller when looking close. In other words, because a driver's viewing position varies depending on the vehicle speed, the perceived curvature of the curve differs depending on the speed, even when viewing the same curve lane. Therefore, the lane display device adjusts the curvature of the curve according to the vehicle speed and displays the curve lane image on the display. Specifically, the lane display device reduces the curvature of the curve lane image displayed on the display when the vehicle speed is slow compared to when the vehicle speed is fast. As a result, the lane display device can provide a display based on the vehicle speed and the driver's perception of the curvature. In this way, the lane display device can display a curve lane image while suppressing the driver from feeling uncomfortable.

[0008] The lane display device described above may be [2] "the display control unit, which makes the curvature of the curve of the curve lane image displayed on the display proportional to the vehicle speed, and makes the curvature of the curve of the curve lane image smaller as the vehicle speed decreases."

[0009] In this way, the lane display device makes the curvature of the curve lane image displayed on the display proportional to the vehicle speed. By doing so, the lane display device can display the curve lane image to better match the driver's perception, even when the driver's perception of the degree of curvature of the curve differs depending on the vehicle speed.

[0010] The lane display device described above may be [3] “the display control unit generates a first reference curve image based on the curvature of the curve lane around the vehicle based on the acquired curve information, extracts an image of a predetermined first angle range according to the curve from the generated first reference curve image, enlarges the extracted first reference curve image to a predetermined display size, generates a curve lane image based on the curvature of the enlarged first reference curve image, displays the generated curve lane image on the display, and the display control unit reduces the first angle range when the vehicle speed is slow compared to when the vehicle speed is fast, the lane display device described in [1] or [2].”

[0011] In this case, the lane display device can obtain the curvature of the curve of the curve lane image to be displayed by extracting a part of the first reference curve image and enlarging the extracted first reference curve image. At that time, the display control unit reduces the first angle range for extracting the image when the vehicle speed is slow compared to when the vehicle speed is fast. By reducing the first angle range, the length of the curve of the extracted first reference curve image becomes shorter. By enlarging the first reference curve image extracted in this way to a predetermined display size, a first reference curve image with a smaller curvature as the first angle range becomes smaller can be obtained. And, by using the curvature of the first reference curve image obtained in this way, a curve lane image with a smaller degree of curvature as the first angle range becomes smaller (as the vehicle speed becomes slower) can be obtained. That is, the lane display device can reduce the degree of curvature of the curve lane image displayed on the display when the vehicle speed is slow compared to when the vehicle speed is fast by adjusting the first angle range based on the vehicle speed as described above. In this way, by using a method of enlarging the image of the first angle range extracted according to the vehicle speed, the lane display device can generate a curve lane image that suppresses the driver from feeling a sense of unease.

[0012] The lane display device described above may be [4] a lane display device described in [1] or [2], wherein the display control unit acquires a first reference radius of curvature based on the curvature of the curve lane around the vehicle based on the acquired curve information, adjusts the first reference radius of curvature so that the first reference radius of curvature becomes longer when the vehicle speed is slow compared to when the vehicle speed is fast, generates the curve lane image based on the adjusted first reference radius of curvature, and displays the generated curve lane image on the display.

[0013] In this case, the lane display device acquires a first reference radius of curvature based on the curvature of the curve lane around the vehicle, and by adjusting this first reference radius of curvature according to the vehicle speed, it can obtain the radius of curvature of the curve lane image to be displayed. At that time, the display control unit lengthens the first reference radius of curvature when the vehicle speed is slow compared to when the vehicle speed is fast. The longer the first reference radius of curvature becomes (the slower the vehicle speed), the smaller the curvature of the curve lane image can be obtained. That is, by adjusting the first reference radius of curvature based on the vehicle speed as described above, the lane display device can reduce the curvature of the curve lane image displayed on the display when the vehicle speed is slow compared to when the vehicle speed is fast. In this way, by using a method of adjusting the radius of curvature according to the vehicle speed, the lane display device can generate a curve lane image that suppresses the driver from feeling a sense of unease.

[0014] The lane display device described above may be [5] a lane display device described in any one of [1] to [4], which further comprises a gaze height acquisition unit for acquiring the gaze height of the driver of the vehicle, and the display control unit, when the driver's gaze height is low, reduces the curvature of the curved lane image displayed compared to when the gaze height is high.

[0015] For example, when a driver's line of sight is low, they tend to drive while looking at road conditions closer to their vehicle compared to when their line of sight is high. Additionally, even when viewing the same curve, drivers tend to perceive the curvature as greater when looking far away and smaller when looking close. In other words, because a driver's viewing position varies depending on their line of sight, the perceived curvature of the curve differs depending on the line of sight, even when viewing the same curve. Therefore, the lane display device adjusts the curvature of the curve according to the line of sight and displays the curve image on the display. Specifically, the lane display device reduces the curvature of the curve image displayed on the display when the driver's line of sight is low compared to when the line of sight is high. By doing so, the lane display device can provide a display based on the driver's line of sight and the driver's perception of the curvature. Therefore, the lane display device can display a curve lane image while suppressing the driver from feeling uncomfortable.

[0016] The lane display device described above may be [6] "the display control unit, which makes the curvature of the curve lane image displayed on the display proportional to the driver's line of sight height, and makes the curvature of the curve lane image smaller as the line of sight height is lower."

[0017] In this way, the lane display device makes the curvature of the curve of the curve lane image displayed on the display proportional to the driver's line of sight height. By doing so, the lane display device can display the curve lane image in a way that is more consistent with the driver's perceived curvature, even when the driver's perception of the degree of curvature of the curve differs depending on the line of sight height.

[0018] The lane display device described above may be [7] “the display control unit generates a second reference curve image based on the curvature of the curve lane around the vehicle based on the acquired curve information, extracts an image of a predetermined second angle range according to the curve from the generated second reference curve image, enlarges the extracted second reference curve image to a predetermined display size, generates the curve lane image based on the curvature of the enlarged second reference curve image, displays the generated curve lane image on the display, and the display control unit reduces the second angle range when the driver’s line of sight is low compared to when the line of sight is high, the lane display device described in [5] or [6].”

[0019] In this case, the lane display device can obtain the curve curvature of the curve lane image to be displayed by extracting a portion of the second reference curve image and enlarging the extracted second reference curve image. At that time, the display control unit reduces the second angle range for extracting the image when the driver's line of sight is low compared to when the line of sight is high. By reducing the second angle range, the curve length of the extracted second reference curve image becomes shorter. By enlarging the second reference curve image extracted in this way to a predetermined display size, a second reference curve image with a smaller curve curvature as the second angle range becomes smaller can be obtained. Furthermore, by using the curvature of the second reference curve image obtained in this way, a curve lane image with a smaller degree of curvature as the second angle range becomes smaller (as the vehicle speed becomes slower) can be obtained. That is, the lane display device can reduce the degree of curvature of the curve lane image displayed on the display when the line of sight is low compared to when the line of sight is high by adjusting the second angle range based on the driver's line of sight height as described above. In this way, the lane display device can generate a curve lane image capable of suppressing the driver's sense of unease by using a method of enlarging the image of the second angle range portion extracted based on the line of sight height.

[0020] The lane display device described above may be [8] “the display control unit acquires a second reference radius of curvature based on the curvature of the curve lane around the vehicle based on the acquired curve information, adjusts the second reference radius of curvature so that the second reference radius of curvature becomes longer when the line of sight is low compared to when the line of sight is high, generates the curve lane image based on the adjusted second reference radius of curvature, and displays the generated curve lane image on the display, the lane display device described in [5] or [6].”

[0021] In this case, the lane display device acquires a second reference radius of curvature based on the curvature of the curve lane around the vehicle, and by adjusting this second reference radius of curvature according to the driver's line of sight height of the vehicle, it can obtain the radius of curvature of the curve of the curve lane image to be displayed. At that time, the display control unit lengthens the second reference radius of curvature when the driver's line of sight height is low compared to when the line of sight height is high. As the second reference radius of curvature becomes longer (as the line of sight height becomes lower), a curve lane image with a smaller degree of curvature can be obtained. That is, by adjusting the second reference radius of curvature based on the driver's line of sight height as described above, the lane display device can reduce the degree of curvature of the curve lane image displayed on the display when the line of sight height is low compared to when the line of sight height is high. In this way, by using a method of adjusting the radius of curvature according to the driver's line of sight height, the lane display device can generate a curve lane image that suppresses the driver from feeling a sense of unease. Effects of the invention

[0022] According to one embodiment of the present disclosure, a curve lane image can be displayed while suppressing the driver from feeling a sense of unease. Brief explanation of the drawing

[0023] FIG. 1 is a block diagram illustrating an example of a lane marking device according to an embodiment. Figure 2 is a drawing illustrating an example of a curve lane image displayed on a display. FIG. 3(a) is a side view illustrating the difference in the driver's visibility area of ​​road conditions due to vehicle speed. FIG. 3(b) is a top view illustrating the difference in the driver's visibility area of ​​road conditions due to vehicle speed. FIG. 4(a) is a diagram illustrating the generation of a first reference curve image based on the curvature of the curve lane in front of the vehicle. FIG. 4(b) is a diagram illustrating the generation of a first enlarged reference curve image by enlarging a first extracted reference curve image extracted from the first reference curve image. Figure 5 is a diagram illustrating the generation of a curve lane image according to vehicle speed by adjusting the radius of curvature of the curve lane image. FIG. 6(a) is a side view illustrating the difference in the driver's visibility area of ​​road conditions depending on the driver's line of sight. FIG. 6(b) is a top view illustrating the difference in the driver's visibility area of ​​road conditions depending on the driver's line of sight. FIG. 7(a) is a diagram illustrating the generation of a second reference curve image based on the curvature of the curve lane in front of the vehicle. FIG. 7(b) is a diagram illustrating the generation of a second enlarged reference curve image by enlarging a second extracted reference curve image extracted from the second reference curve image. FIG. 8 is a side view illustrating the relationship between the reference line of sight height of a reference vehicle and the driver's line of sight height of an own vehicle. Figure 9 is a diagram illustrating the generation of a curve lane image according to the driver's line of sight height by adjusting the radius of curvature of the curve lane image. Specific details for implementing the invention

[0024] details

[0025] Hereinafter, exemplary embodiments will be described with reference to the drawings. In addition, in each drawing, identical or equivalent elements are denoted by the same reference numerals, and redundant descriptions are omitted.

[0026] As illustrated in FIG. 1, a lane display device (100) is mounted on a vehicle (X). The lane display device (100) displays a lane image around the vehicle (X) on a display (50). In this embodiment, the lane display device (100) displays a lane image corresponding to a lane in front of the vehicle (X) on the display (50) as a periphery of the vehicle (X). However, the lane display device (100) may display a lane image corresponding to a lane existing in a direction other than in front of the vehicle (X) on the display (50) as a periphery of the vehicle (X).

[0027] The lane image displayed by the lane display device (100) includes a lane image corresponding to the driving lane in which the vehicle (X) is driving. Additionally, the lane image displayed by the lane display device (100) may include a lane image corresponding to an adjacent lane adjacent to the driving lane of the vehicle (X) in addition to the driving lane of the vehicle (X). The lane image displayed by the ECU (10) includes a straight-shaped lane image according to the straight-shaped lane image and a curved lane image that curves according to the shape of the curved lane. Below, a case in which the lane display device (100) displays a curved lane image corresponding to the shape of the curved lane in front of the vehicle (X) on the display (50) is described.

[0028] The lane display device (100) is equipped with an Electronic Control Unit (ECU) (10) that manages the device comprehensively. The ECU (10) is an electronic control unit having a Central Processing Unit (CPU) and a memory unit. The memory unit is composed of, for example, a Read Only Memory (ROM), Random Access Memory (RAM), and an Electrically Erasable Programmable Read-Only Memory (EEPROM). The ECU (10) realizes various functions by, for example, executing a program stored in the memory unit with the CPU. The ECU (10) may be composed of a plurality of electronic control units.

[0029] An external sensor (20), a vehicle speed sensor (30), a driver monitor camera (40), and a display (50) are connected to the ECU (10).

[0030] The external sensor (20) is a vehicle-mounted sensor that detects the external environment of the vehicle (X). The external sensor (20) includes at least a camera or a radar sensor. The camera is an imaging device that captures the external environment of the vehicle (X). The camera is, for example, provided on the other side of the front glass of the vehicle (X) to capture the front of the vehicle. The camera transmits imaging information regarding the external environment of the vehicle (X) to the ECU (10). The camera may be a monocular camera or a stereo camera. Multiple cameras may be provided, and in addition to the front of the vehicle (X), the left side and right side, etc., may be captured.

[0031] A radar sensor is a detection device that detects objects around a vehicle (X) using radio waves (e.g., millimeter waves) or light. A radar sensor includes a LIDAR [Light Detection and Ranging]. The LIDAR detects targets by transmitting light around the vehicle (X) and receiving light reflected from objects. The radar sensor transmits information regarding the external environment of the detected vehicle (X) to the ECU (10).

[0032] The vehicle speed sensor (30) is a detector that detects the vehicle speed of the vehicle (X). The vehicle speed sensor (30) is provided, for example, on the wheel of the vehicle (X) or on a drive shaft that rotates integrally with the wheel, and detects the rotational speed of the wheel. The vehicle speed sensor (30) transmits the vehicle speed information of the vehicle (X) to the ECU (10).

[0033] The driver monitor camera (40) is an imaging device that captures a driver sitting in the driver's seat of the vehicle (X). The driver monitor camera (40) is provided in the vehicle interior of the vehicle (X). The driver monitor camera (40) is installed to capture the face of the driver sitting in the driver's seat. The driver monitor camera (40) transmits the captured image information (face image) to the ECU (10).

[0034] The display (50) is a display device that presents information to the driver of the vehicle (X) visually. The display (50) is provided in the vehicle interior of the vehicle (X). The display (50) may be a center display, a Multi Information Display (MID), or a Head-Up Display (HUD). The type of the display (50) is not limited as long as it can present information visually. The display (50) displays various information according to the control signal of the ECU (10).

[0035] The ECU (10) is functionally equipped with a curve information acquisition unit (11), a vehicle speed acquisition unit (12), a line of sight height acquisition unit (13), and a display control unit (14).

[0036] The curve information acquisition unit (11) acquires curve information including the shape of the curve lane for a curve lane around the vehicle (X) (in the present embodiment, in front of the vehicle (X)). The curve information includes the degree of curvature of the curve as the shape of the curve lane. The degree of curvature of the curve can be expressed by the curve curvature of the curve lane or the radius of curvature.

[0037] The curve information acquisition unit (11) can acquire curve information of a curve lane ahead of the vehicle (X) based on the detection result of the external sensor (20). For example, if a camera is provided as the external sensor (20), the curve information acquisition unit (11) can acquire curve information of the curve lane by using a well-known image processing technique on the captured image of the camera to recognize a white line, etc. Similarly, if a LiDAR is provided as the external sensor (20), the curve information acquisition unit (11) can acquire curve information of the curve lane from the detection result of the LiDAR based on the difference in light reflectivity between the white line and the road surface, etc.

[0038] Additionally, the curve information acquisition unit (11) may acquire curve information of a curve lane ahead of the vehicle (X) based on map information including the driving position of the vehicle (X) and information regarding the shape of the lane. The method of acquiring curve information acquired by the curve information acquisition unit (11) is not limited.

[0039] The vehicle speed acquisition unit (12) acquires the vehicle speed of the vehicle (X). The vehicle speed acquisition unit (12) can acquire the vehicle speed based, for example, on the detection result of the vehicle speed sensor (30). The method of acquiring the vehicle speed acquired by the vehicle speed acquisition unit (12) is not limited.

[0040] The eye level acquisition unit (13) acquires the eye level of the driver of the vehicle (X). This eye level is the height from the road surface where the vehicle (X) is traveling to the driver's eyes. The eye level varies depending on the type of vehicle (X), the size (garage height) of the vehicle (X), etc. For this reason, the eye level when a driver of a standard height is riding in the vehicle is predetermined for each vehicle. For example, as the size of the vehicle increases or the garage height increases, a higher eye level is predetermined for each vehicle. The eye level acquisition unit (13) can acquire the predetermined eye level for the vehicle (X).

[0041] In addition, the eye level varies depending on the height of the driver actually riding in the vehicle (X), in addition to the type of vehicle (X). For this reason, the eye level acquisition unit (13) may detect the eye level position of the driver actually riding in the vehicle (X) and acquire the eye level based on the detected eye position. In this case, the eye level acquisition unit (13) detects the position of the eyes using known image processing techniques, for example, on a face image of the driver captured by the driver monitor camera (40). Then, the eye level acquisition unit (13) may acquire the eye level based on the detected eye position. At that time, the eye level acquisition unit (13) may acquire the eye level position based on the detected eye position and the size information of the vehicle (X) (for example, garage height, height of the driver's seat surface, etc.). In this case, the eye level acquisition unit (13) can acquire the eye level of the driver actually riding in the vehicle (X) with higher precision.

[0042] The display control unit (14) displays a lane image corresponding to the lane ahead of the vehicle (X) on the display (50). If the lane ahead of the vehicle (X) is a curved lane, the display control unit (14) displays a curved lane image corresponding to the shape of the curved lane ahead on the display (50) based on the curve information acquired by the curve information acquisition unit (11). For example, the depth of the lane image displayed on the display (50) is fixed. In this case, the display control unit (14) displays the lane shape up to a predetermined distance ahead from the vehicle (X).

[0043] For example, when the display control unit (14) displays a curve lane image on the display (50), as shown in FIG. 2, it displays a vehicle icon (XA) corresponding to the vehicle (X) and a curve lane image (CA) corresponding to the curve lane in front of the vehicle (X). The curve lane image (CA) may be composed of two dividing lines (CAa) that separate the curve lane and other areas, as shown in FIG. 2, for example. Alternatively, the curve lane image (CA) may be displayed by color-separating the curve lane and other areas.

[0044] In addition, in FIG. 2, a curve lane image (CA) corresponding to a curve lane ahead of the vehicle (X) is displayed. If the lane ahead of the vehicle (X) is in a straight line shape, the display control unit (14) displays a straight line lane image on the display (50). In addition, the display control unit (14) may display other vehicle icons, such as vehicles surrounding the vehicle (X), on the display (50) in addition to the lane image such as the curve lane image (CA).

[0045] Here, generally, when a person drives a vehicle, they drive while observing the road conditions a certain amount of time ahead. That is, when the vehicle speed is slow, the driver tends to drive while observing the road conditions closer to the vehicle compared to when the vehicle speed is fast. For example, as shown at the top of FIG. 3 (a), when the vehicle speed of the vehicle (X) is v1, the driver of the vehicle (X) drives while observing the road conditions t seconds ahead of the driver (road conditions up to t seconds ahead). In this case, the driver is observing the conditions at a distance L1 [m] (t [s] × vehicle speed v1 [m / s]) ahead. For example, as shown at the bottom of FIG. 3 (b), when the vehicle speed of the vehicle (X) is v2, which is faster than v1, the driver of the vehicle (X) drives while observing the road conditions t seconds ahead of the driver (road conditions up to t seconds ahead). In this case, the driver is looking at the situation at a distance L2 [m] (t [s] × vehicle speed v2 [m / s]) ahead. That is, the driver of the vehicle (X) is looking at a point closer to the vehicle (X) when the vehicle speed is v1, compared to when the vehicle speed is v2, which is faster than v1.

[0046] Furthermore, even when looking at the same curve lane, drivers tend to perceive the curvature as greater when looking at a distant point and smaller when looking at a close point. In other words, because the driver's viewing position differs depending on the vehicle speed, the perception of the curvature varies depending on the vehicle speed, even when looking at the same curve lane. For example, the vehicle (X) shown in FIG. 3(a) is traveling on the curve lane (C) as shown in FIG. 3(b). When the vehicle speed of the vehicle (X) is v1, the driver is looking at the situation at a close distance L1 ahead of the vehicle (X), so the curvature of the curve lane (C) feels small. On the other hand, when the vehicle speed of the vehicle (X) is v2, the driver is looking at the situation at a distant distance L2 ahead of the vehicle (X), so the curvature of the curve lane (C) feels larger than when the vehicle speed is v1.

[0047] Accordingly, when the display control unit (14) displays a curve lane image based on curve information acquired by the curve information acquisition unit (11), it displays the curve lane image by taking into account the difference in the degree of curvature of the curve lane felt by the driver according to the vehicle speed of the vehicle (X). Here, the display control unit (14) reduces the degree of curvature of the curve lane image displayed on the display (50) when the vehicle speed of the vehicle (X) acquired by the vehicle speed acquisition unit (12) is slow compared to when the vehicle speed is fast. In addition, the display control unit (14) makes the curve curvature of the curve lane image displayed on the display (50) proportional to the vehicle speed, so that the curve curvature of the curve lane image becomes smaller as the vehicle speed decreases.

[0048] For example, the display control unit (14) generates a reference curve lane image based on curve information acquired by the curve information acquisition unit (11). Then, the display control unit (14) may adjust the degree of curvature of the generated curve lane image according to the vehicle speed of the vehicle (X). Here, the display control unit (14) adjusts the reference curve lane image so that the degree of curvature becomes smaller when the vehicle speed of the vehicle (X) is slow compared to when the vehicle speed is fast.

[0049] Here, an example of a method for generating a curve lane image based on vehicle speed, performed by the display control unit (14), is described. First, a first method for generating a curve lane image based on vehicle speed is described. As shown in FIG. 4 (a), the display control unit (14) generates a first reference curve image (CR1) based on the curvature of the curve lane in front of the vehicle (X), based on curve information acquired by the curve information acquisition unit (11). The display control unit (14) increases the curvature of the first reference curve image (CR1) as the curvature of the curve lane included in the curve information increases. For example, the display control unit (14) generates the first reference curve image (CR1) only to the extent of the display depth of the curve lane image displayed on the display (50).

[0050] Additionally, for example, the display control unit (14) generates a curve lane image to be displayed on the display (50) as a first reference curve image (CR1) based on the curvature of the curve lane included in the curve information when the vehicle (X) is traveling at a reference speed V [m / s]. Here, let the radius of curvature of the first reference curve image (CR1) be r [m]. However, the method of generating the first reference curve image (CR1) is not limited as long as it is generated based on the curvature of the curve lane included in the curve information.

[0051] Next, as illustrated in FIG. 4(b), the display control unit (14) extracts an image of a predetermined first angle range according to the curve of the first reference curve image (CR1) from the generated first reference curve image (CR1). Let the image from which a predetermined first angle range is extracted from the first reference curve image (CR1) be called the first extracted reference curve image (CR1a). When the vehicle speed of the self vehicle (X) acquired by the vehicle speed acquisition unit (12) is slow, the display control unit (14) makes the first angle range smaller compared to when the vehicle speed is fast.

[0052] For example, the display control unit (14) may determine the first angle range based on the angle range θ of the first reference curve image (CR1) and the vehicle speed of the self-vehicle (X) when the first reference curve image (CR1) is created to be the display depth on the display (50), as shown in FIG. 4 (a). Here, for example, as shown in FIG. 4 (b), the vehicle speed of the self-vehicle (X) is set to α1×V [m / s]. Also, α1 is set to be less than 1. That is, as an example, the case where the vehicle speed of the self-vehicle (X) is slower than the reference speed V [m / s] used when the first reference curve image (CR1) shown in FIG. 4 (a) was created is described. The angle range according to the curve when the first reference curve image (CR1) is created to be the display depth of the display (50) is set to angle θ. In this case, as an example, the display control unit (14) may set the first angle range for extracting the first extraction reference curve image (CR1a) from the first reference curve image (CR1) to α1×θ. That is, as the vehicle speed of the vehicle (X) decreases, the first angle range becomes smaller, and the length of the first extraction reference curve image (CR1a) being extracted also becomes shorter.

[0053] Next, the display control unit (14) expands the first extracted reference curve image (CR1a) extracted from the first reference curve image (CR1) to a predetermined display size. Here, the display control unit (14) expands the depth (size in the vertical direction) of the first extracted reference curve image (CR1a) until it reaches the size of the display depth of the display (50). Additionally, when expanding the first extracted reference curve image (CR1a), the display control unit (14) expands it while maintaining the aspect ratio of the image. Let the image obtained by expanding the first extracted reference curve image (CR1a) to a predetermined display size be called the first enlarged reference curve image (CR1b). That is, as the enlargement ratio of the first extracted reference curve image (CR1a) increases, the radius of curvature of the first enlarged reference curve image (CR1b) increases. In other words, as the vehicle speed of the self-vehicle (X) decreases, the first angle range extracted as the first extraction reference curve image (CR1a) becomes smaller, and the radius of curvature of the first enlarged reference curve image (CR1b) obtained by enlarging the extracted first extraction reference curve image (CR1a) becomes larger.

[0054] Next, the display control unit (14) generates a curve lane image according to the vehicle speed of the self-vehicle (X) based on the curve curvature (or radius of curvature) of the first enlarged reference curve image (CR1b) which is an enlarged version of the first extracted reference curve image (CR1a). The display control unit (14) displays the generated curve lane image on the display (50).

[0055] Next, a second method for generating a curve lane image based on vehicle speed is described. As shown in FIG. 5, the display control unit (14) acquires a first reference radius of curvature r [m] based on the curvature of the curve lane ahead of the vehicle (X) based on the curve information acquired by the curve information acquisition unit (11). The display control unit (14) makes the first reference radius of curvature r smaller as the curvature of the curve lane included in the curve information increases. Additionally, for example, the display control unit (14) may acquire the radius of curvature of the curve lane image (CR2) displayed on the display (50) as the first reference radius of curvature r when the vehicle (X) is traveling at a reference speed V [m / s] based on the curvature of the curve lane included in the curve information. That is, the curve lane image (CR2) is an image obtained based on curve information obtained by the curve information acquisition unit (11), and is an image obtained based on the curvature of the curve lane in front of the vehicle (X). As long as it is generated based on the curvature of the curve lane included in the curve information, the method of obtaining the first reference curvature radius r is not limited.

[0056] The display control unit (14) adjusts the first reference radius of curvature r such that when the vehicle speed of the self-vehicle (X) acquired by the vehicle speed acquisition unit (12) is slow, the first reference radius of curvature r becomes longer compared to when the vehicle speed is fast. For example, as shown in FIG. 5, the vehicle speed of the self-vehicle (X) is set to α1×V[m / s]. Also, α1 is set to be less than 1. That is, as an example, the case where the vehicle speed of the self-vehicle (X) is slower than the reference speed V[m / s] used when acquiring the first reference radius of curvature r is described here. In this case, as an example, the display control unit (14) may use r / α1[m] as the first reference radius of curvature r after adjustment. That is, as the vehicle speed of the self-vehicle (X) slows down, α1 becomes smaller, and the first reference radius of curvature r / α1[m] after adjustment becomes longer. As the first reference radius of curvature r / α1[m] after adjustment increases, the curvature of the curve lane image (CR2a) shown in FIG. 5 decreases.

[0057] The display control unit (14) generates a curve lane image using a first reference radius of curvature adjusted based on the vehicle speed of the vehicle (X). The display control unit (14) displays the generated curve lane image on the display (50).

[0058] The first and second methods for generating a curve lane image based on vehicle speed described above are examples of specific generation methods. The display control unit (14) is configured to generate a curve lane image with a smaller degree of curvature when the vehicle speed of the self-vehicle (X) is slow compared to when the vehicle speed is fast.

[0059] In addition, the above description explains the case of generating a curve lane image displayed on the display (50), taking into account that the driver’s perception of the degree of curvature of the curve varies depending on the vehicle speed (X). Furthermore, the driver’s perception of the degree of curvature of the curve also varies depending on the driver’s line of sight of the vehicle (X).

[0060] For example, when the driver of a vehicle (X) has a low line of sight, the driver tends to drive while looking at road conditions close to the vehicle (X) compared to when the line of sight is high. That is, as the line of sight increases, the driver tends to drive while looking at distant objects. For example, as shown at the top of FIG. 6 (a), when the vehicle speed of the vehicle (X) is v1, the driver of the vehicle (X) drives while looking at road conditions t seconds ahead of the driver (road conditions up to t seconds ahead). In this case, the driver is looking at conditions at a distance L1 [m] (t [s] × vehicle speed v1 [m / s]) ahead. For example, at the bottom of FIG. 6 (a), a vehicle (Xa) with a larger body than the vehicle (X) at the top of FIG. 6 (a) is shown. That is, the height of the driver's line of sight of the vehicle (Xa) at the bottom of Fig. 6 (a) is higher than the height of the driver's line of sight of the vehicle (X) at the top of Fig. 6 (a). In this case, the driver of the vehicle (Xa) at the bottom of Fig. 6 (b) drives while looking at the situation ahead of the driver of the vehicle (X) at the top of Fig. 6 (a).

[0061] For example, let us assume that the eye level of the driver riding in the vehicle (Xa) at the bottom of FIG. 6 (a) is α2 times higher than the eye level of the driver riding in the vehicle (X) at the top of FIG. 6 (a). Also, α2 is greater than 1. The vehicle speed of the vehicle (Xa) at the bottom of FIG. 6 (a) and the vehicle speed of the vehicle (X) at the top of FIG. 6 (a) are set to the same vehicle speed v1. In this case, for example, the driver riding in the vehicle (Xa) at the bottom of FIG. 6 (a) is looking at the situation a distance L3 [m] (t [s] × vehicle speed v1 [m / s] × α2) ahead. That is, the driver riding in the vehicle (X) at the top of FIG. 6 (a) is looking at a point closer to the vehicle (X) than the driver riding in the vehicle (Xa) at the bottom of FIG. 6 (a).

[0062] In addition, as described above, even when looking at the same curve lane, drivers tend to perceive the degree of curvature as greater when looking at a distant point and as smaller when looking at a close point. In other words, since the viewing position differs depending on the height of the driver's gaze, the perception of the degree of curvature of the curve differs depending on the height of the gaze, even when looking at the same curve lane. For example, the vehicle (X, Xa) shown in FIG. 6 (a) is driving on the curve lane (C) as shown in FIG. 6 (b). The driver of the vehicle (X) is looking at the situation at a distance L1 ahead from the vehicle (X), so the degree of curvature of the curve lane (C) feels small. On the other hand, the driver of the vehicle (Xa) has a higher height of gaze than the vehicle (X) and is looking at the situation at a distance L3 ahead from the vehicle (X). Because of this, the driver of the vehicle (Xa) feels the curvature of the curve lane (C) more strongly than the driver of the vehicle (X).

[0063] Accordingly, when the display control unit (14) displays a curve lane image based on curve information acquired by the curve information acquisition unit (11), it displays the curve lane image by taking into account the difference in the degree of curvature of the curve lane perceived by the driver according to the line of sight height. Here, the display control unit (14) reduces the degree of curvature of the curve lane image displayed on the display (50) when the driver's line of sight height acquired by the line of sight height acquisition unit (13) is low compared to when the line of sight height is high. In addition, the display control unit (14) makes the curve curvature of the curve lane image displayed on the display (50) proportional to the line of sight height, so that the lower the line of sight height, the smaller the curve curvature of the curve lane image.

[0064] For example, the display control unit (14) generates a reference curve lane image based on curve information acquired by the curve information acquisition unit (11). Then, the display control unit (14) may adjust the degree of curvature of the generated curve lane image according to the driver's line of sight height. Here, the display control unit (14) adjusts the reference curve lane image so that the degree of curvature becomes smaller when the driver's line of sight height is low compared to when the line of sight height is high.

[0065] Here, an example of a method for generating a curve lane image based on the driver's line of sight, performed by the display control unit (14), is described. First, a first method for generating a curve lane image based on the driver's line of sight is described. As shown in FIG. 7 (a), the display control unit (14) generates a second reference curve image (CR3) based on the curvature of the curve lane in front of the vehicle (X), based on curve information acquired by the curve information acquisition unit (11). The display control unit (14) increases the curvature of the second reference curve image (CR3) as the curvature of the curve lane included in the curve information increases. For example, the display control unit (14) generates the second reference curve image (CR3) only to the depth of the curve lane image displayed on the display (50).

[0066] Additionally, as shown at the top of FIG. 8, for example, the eye level of a driver riding in a reference vehicle (Xb) is denoted as the reference eye level H [m]. The height of the driver riding in the reference vehicle (Xb) is predetermined, such as being the height of a standard person. The display control unit (14) may generate a curve lane image to be displayed on the display (50) when the reference vehicle (Xb) is driving on the curve lane, based on the curvature of the curve lane included in the curve information, as the second reference curve image (CR3). Here, the display control unit (14) generates a curve lane image when the reference vehicle (Xb) is driving on the curve lane included in the curve information at a predetermined reference speed V [m / s] as the second reference curve image (CR3). Here, let the radius of curvature of the second reference curve image (CR3) be r1 [m]. However, if it is generated based on the curvature of the curve lane included in the curve information, the method of generating the second reference curve image (CR3) is not limited.

[0067] Next, as illustrated in FIG. 7(b), the display control unit (14) extracts an image of a predetermined second angle range according to the curve of the second reference curve image (CR3) from the generated second reference curve image (CR3). Let the image from which a predetermined second angle range is extracted from the second reference curve image (CR3) be called the second extracted reference curve image (CR3a). When the line of sight of the driver of the vehicle (X) acquired by the line of sight height acquisition unit (13) is low, the display control unit (14) makes the second angle range smaller compared to when the line of sight height is high.

[0068] For example, the display control unit (14) may determine a second angle range based on the angle range θ of the second reference curve image (CR3) when the second reference curve image (CR3) is created to be the depth of display on the display (50) as shown in FIG. 7 (a), and the line of sight height of the driver of the vehicle (X). Here, for example, as shown in FIG. 8, the line of sight height of the driver of the vehicle (X) is set to α3×H [m]. Also, α3 is set to be less than 1. That is, here, as an example, the case where the line of sight height of the driver of the vehicle (X) is lower than the reference line of sight height H of the driver of the reference vehicle (Xb) is described. Let the angle range according to the curve when the second reference curve image (CR3) is created to be the depth of display on the display (50) as shown in FIG. 7 (a) be the angle θ. In this case, as an example, the display control unit (14) may set the second angle range for extracting the second extraction reference curve image (CR3a) from the second reference curve image (CR3) to α3×θ. That is, as the height of the driver's line of sight of the vehicle (X) decreases, the second angle range becomes smaller, and the length of the second extraction reference curve image (CR3a) being extracted also becomes shorter.

[0069] Next, the display control unit (14) expands the second extracted reference curve image (CR3a), extracted from the second reference curve image (CR3), to a predetermined display size. Here, the display control unit (14) expands the depth (size in the vertical direction) of the second extracted reference curve image (CR3a) until it reaches the size of the display depth of the display (50). Additionally, when expanding the second extracted reference curve image (CR3a), the display control unit (14) expands it while maintaining the aspect ratio of the image. Let the image obtained by expanding the second extracted reference curve image (CR3a) to a predetermined display size be called the second enlarged reference curve image (CR3b). That is, as the enlargement ratio of the second extracted reference curve image (CR3a) increases, the radius of curvature of the second enlarged reference curve image (CR3b) increases. In other words, as the driver's line of sight of the vehicle (X) decreases, the second angle range extracted as the second extraction reference curve image (CR3a) becomes smaller, and the radius of curvature of the second enlarged reference curve image (CR3b) obtained by enlarging the extracted second extraction reference curve image (CR3a) becomes larger.

[0070] Next, the display control unit (14) generates a curve lane image according to the vehicle speed of the self-vehicle (X) based on the curve curvature (or radius of curvature) of the second enlarged reference curve image (CR3b) which is an enlarged version of the second extracted reference curve image (CR3a). The display control unit (14) displays the generated curve lane image on the display (50).

[0071] Next, a second method for generating a curve lane image based on the driver's line of sight is described. As shown in FIG. 9, the display control unit (14) acquires a second reference radius of curvature r1 [m] based on the curvature of the curve lane in front of the vehicle (X) based on the curve information acquired by the curve information acquisition unit (11). The display control unit (14) makes the second reference radius of curvature r1 smaller as the curvature of the curve lane included in the curve information increases. Additionally, for example, the display control unit (14) generates a curve lane image (CR4) that is displayed on the display (50) when the reference vehicle (Xb) is driving on this curve lane, based on the curvature of the curve lane included in the curve information. Here, the display control unit (14) generates a curve lane image (CR4) when the reference vehicle (Xb) is traveling at a predetermined reference speed V [m / s] on the curve lane included in the curve information. Then, the display control unit (14) may acquire the radius of curvature of the generated curve lane image (CR4) as a second reference radius of curvature r1. That is, the curve lane image (CR4) is an image obtained based on the curve information acquired by the curve information acquisition unit (11), and is an image obtained based on the curvature of the curve lane in front of the vehicle (X). As long as it is generated based on the curvature of the curve lane included in the curve information, the method of acquiring the second reference radius of curvature r1 is not limited.

[0072] The display control unit (14) adjusts the second reference radius of curvature r1 so that when the driver of the vehicle (X) has a low line of sight height according to the line of sight height acquisition unit (13), the second reference radius of curvature r1 becomes longer than when the line of sight height is high. For example, as shown at the bottom of FIG. 8, the line of sight height of the driver of the vehicle (X) is set to α3×H[m]. Also, α3 is set to be less than 1. That is, as an example, the case where the line of sight height of the driver of the vehicle (X) is lower than the reference line of sight height H[m] of the driver of the reference vehicle (Xb) used when acquiring the second reference radius of curvature r1 is described. In this case, as an example, the display control unit (14) may use r1 / α3[m] as the second reference radius of curvature r1 after adjustment. That is, as the driver's line of sight of the vehicle (X) decreases, α3 becomes smaller, and the second reference radius of curvature r1 / α3 [m] after adjustment becomes longer. As the second reference radius of curvature r1 / α3 [m] after adjustment becomes longer, the curvature of the curve lane image (CR4a) shown in FIG. 9 becomes smaller.

[0073] The display control unit (14) generates a curve lane image using a second reference radius of curvature adjusted based on the driver's line of sight of the vehicle (X). The display control unit (14) displays the generated curve lane image on the display (50).

[0074] The first and second methods for generating a curve lane image based on the eye level of the driver of the vehicle (X), as described above, are examples of specific generation methods. The display control unit (14) is configured to generate a curve lane image with a smaller degree of curvature when the eye level of the driver of the vehicle (X) is low compared to when the eye level is high.

[0075] Additionally, as described above, the display control unit (14) can adjust the degree of curvature of the curve lane image displayed on the display (50) based on the vehicle speed of the vehicle (X) and based on the eye level of the driver of the vehicle (X). For example, the display control unit (14) reduces the degree of curvature of the curve lane image displayed as the vehicle speed of the vehicle (X) decreases, and reduces the degree of curvature of the curve lane image displayed as the eye level of the driver of the vehicle (X) decreases as the eye level of the driver of the vehicle (X) decreases. In this way, the display control unit (14) adjusts the degree of curvature of the curve lane image displayed by combining the vehicle speed of the vehicle (X) and the eye level of the driver of the vehicle (X).

[0076] As described above, since the driver of the vehicle (X) has a different viewing position depending on the vehicle speed, even when looking at the same curved lane, the perceived degree of curvature of the curve varies depending on the vehicle speed. Therefore, the lane display device (100) adjusts the degree of curvature of the curve according to the vehicle speed and displays the curved lane image on the display (50). Specifically, when the vehicle speed is slow, the lane display device (100) reduces the degree of curvature of the curved lane image displayed on the display (50) compared to when the vehicle speed is fast. By doing so, the lane display device (100) can display the curved lane image according to the driver's perceived degree of curvature based on the vehicle speed. In this way, the lane display device (100) can display the curved lane image while suppressing the driver from feeling a sense of unease.

[0077] The lane display device (100) makes the curvature of the curve of the curve lane image displayed on the display (50) proportional to the vehicle speed of the vehicle (X). By doing so, the lane display device (100) can display the curve lane image to better match the driver's perception of the degree of curvature of the curve, even when the driver's perception of the curvature of the curve differs depending on the vehicle speed.

[0078] The lane display device (100) can generate a curve lane image by using a first method for generating a curve lane image based on vehicle speed. Specifically, as shown in FIG. 4 (a) and FIG. 4 (b), the lane display device (100) can obtain the curve curvature of the curve lane image to be displayed by extracting a first extraction reference curve image (CR1a) of a first angle range from a first reference curve image (CR1) and enlarging the extracted first extraction reference curve image (CR1a). At that time, when the vehicle speed of the self vehicle (X) is slow, the lane display device (100) reduces the first angle range for extracting the image compared to when the vehicle speed is fast. By reducing the first angle range, the length of the curve of the first extraction reference curve image (CR1a) extracted from the first reference curve image (CR1) becomes shorter. By expanding the first extracted reference curve image (CR1a) extracted in this manner to a predetermined display size, a first enlarged reference curve image (CR1b) (an image obtained by enlarging a part of the first reference curve image (CR1)) with a smaller curve curvature as the first angle range becomes smaller can be obtained. Furthermore, by using the curvature of the first enlarged reference curve image (CR1b) obtained in this manner, a curve lane image with a smaller degree of curvature as the first angle range becomes smaller (as the vehicle speed becomes slower) can be obtained. That is, the lane display device (100) can reduce the degree of curvature of the curve lane image displayed on the display (50) when the vehicle speed is slow compared to when the vehicle speed is fast by adjusting the first angle range based on the vehicle speed as described above. In this way, the lane display device (100) can generate a curve lane image that suppresses the driver's sense of unease by using a method of enlarging the image of the first angle range extracted according to the vehicle speed.

[0079] The lane display device (100) can generate a curve lane image by using a second method for generating a curve lane image based on vehicle speed. Specifically, the lane display device (100) can acquire the radius of curvature of the curve lane image (CR2) displayed on the display (50) as a first reference radius of curvature r, based on the curvature of the curve lane ahead of the vehicle (X) as shown in FIG. 5, when the vehicle (X) is traveling at a reference speed V [m / s]. The lane display device (100) can obtain the radius of curvature of the curve lane image to be displayed by adjusting this first reference radius of curvature according to the vehicle speed. At that time, the lane display device (100) makes the first reference radius of curvature longer when the vehicle speed of the vehicle (X) is slow compared to when the vehicle speed is fast. As the first radius increases (the slower the vehicle speed), a curved lane image with a smaller degree of curvature can be obtained. That is, the lane display device (100) can reduce the degree of curvature of the curved lane image displayed on the display (50) when the vehicle speed is slow compared to when the vehicle speed is fast by adjusting the first radius of curvature based on the vehicle speed as described above. In this way, the lane display device (100) can generate a curved lane image that suppresses the driver's sense of unease by using a method of adjusting the radius of curvature according to the vehicle speed.

[0080] In addition, even when a driver is looking at the same curved lane, the perceived degree of curvature of the curve differs depending on the height of their gaze. For this reason, the lane display device (100) adjusts the degree of curvature of the curve according to the height of the gaze and displays the curved lane image on the display (50). Specifically, when the driver of the vehicle (X) has a low gaze height, the lane display device (100) reduces the degree of curvature of the curved lane image displayed on the display (50) compared to when the gaze height is high. By doing so, the lane display device (100) can display the curved lane image according to the driver's perception of the degree of curvature based on the driver's gaze height. Therefore, the lane display device (100) can display the curved lane image while suppressing the driver from feeling a sense of unease.

[0081] The lane display device (100) makes the curvature of the curve of the curve lane image displayed on the display (50) proportional to the eye level of the driver of the vehicle (X). By doing so, the lane display device (100) can display the curve lane image in a way that further matches the driver's perception of the degree of curvature of the curve, even when the driver's perception of the curvature of the curve differs depending on the eye level.

[0082] The lane display device (100) can generate a curve lane image by using a first method for generating a curve lane image based on the line of sight height. Specifically, as shown in FIG. 7 (a) and FIG. 7 (b), the lane display device (100) can obtain the curve curvature of the curve lane image to be displayed by extracting a second extraction reference curve image (CR3a) (a part of the second reference curve image) from a second reference curve image (CR3) and enlarging the extracted second extraction reference curve image (CR3a). At that time, when the driver's line of sight height is low, the lane display device (100) reduces the second angle range for extracting the second extraction reference curve image (CR3a) compared to when the line of sight height is high. By reducing the second angle range, the length of the curve of the extracted second extraction reference curve image (CR3a) becomes shorter. By expanding the second extracted reference curve image (CR3a) extracted in this manner to a predetermined display size, a second enlarged reference curve image (CR3b) (an image obtained by enlarging a part of the second reference curve image (CR3)) with a smaller curve curvature as the second angle range becomes smaller can be obtained. Furthermore, by using the curvature of the second enlarged reference curve image (CR3b) obtained in this manner, a curve lane image with a smaller degree of curvature as the second angle range becomes smaller (as the vehicle speed becomes slower) can be obtained. That is, the lane display device (100) can reduce the degree of curvature of the curve lane image displayed on the display (50) when the gaze height is low compared to when the gaze height is high by adjusting the second angle range based on the driver's gaze height as described above. In this way, the lane display device (100) can generate a curve lane image that suppresses the driver's sense of unease by using a method of enlarging the image of the second angle range extracted based on the gaze height.

[0083] The lane display device (100) can generate a curve lane image by using a second method of generating a curve lane image based on the driver's line of sight height. Specifically, the lane display device (100) generates a curve lane image (CR4) that is displayed on the display (50) when the reference vehicle (Xb) is driving on the curve lane, based on the curvature of the curve lane in front of the vehicle (X) as shown in FIG. 9. The lane display device (100) can obtain the radius of curvature of the generated curve lane image (CR4) as a second reference radius of curvature r1. The lane display device (100) can obtain the radius of curvature of the curve lane image to be displayed by adjusting this second reference radius of curvature according to the driver's line of sight height of the vehicle (X). At that time, the lane display device (100) lengthens the second reference radius of curvature when the driver of the vehicle (X) has a lower line of sight compared to when the line of sight is higher. As the second reference radius of curvature lengthens (as the line of sight becomes lower), a curved lane image with a smaller degree of curvature can be obtained. That is, the lane display device (100) can reduce the degree of curvature of the curved lane image displayed on the display (50) when the line of sight is lower compared to when the line of sight is higher by adjusting the second reference radius of curvature based on the driver's line of sight as described above. In this way, the lane display device (100) can generate a curved lane image that suppresses the driver's discomfort by using a method of adjusting the radius of curvature according to the driver's line of sight.

[0084] Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. For example, the display control unit (14) adjusted the degree of curvature of the curve lane image displayed on the display (50) based on the vehicle speed of the vehicle (X) and the eye level of the driver of the vehicle (X). Not limited thereto, the display control unit (14) may be configured to adjust the degree of curvature of the curve lane image based on either the vehicle speed of the vehicle (X) or the eye level of the driver of the vehicle (X).

Claims

Claim 1 A lane display device comprising: a curve information acquisition unit for acquiring curve information including the shape of a curve lane around a vehicle; a display control unit for displaying a curve lane image according to the shape of the curve lane around the vehicle based on the acquired curve information; and a vehicle speed acquisition unit for acquiring the vehicle speed of the vehicle, wherein the display control unit reduces the degree of curvature of the curve lane image displayed on the display when the vehicle speed is slow compared to when the vehicle speed is fast. Claim 2 A lane display device according to claim 1, wherein the display control unit makes the curvature of the curve of the curve lane image displayed on the display proportional to the vehicle speed, and makes the curvature of the curve of the curve lane image smaller as the vehicle speed decreases. Claim 3 A lane display device according to claim 1 or 2, wherein the display control unit generates a first reference curve image based on the curvature of the curve lane around the vehicle based on the acquired curve information, extracts an image of a predetermined first angle range according to the curve from the generated first reference curve image, enlarges the extracted first reference curve image to a predetermined display size, generates the curve lane image based on the curve curvature of the enlarged first reference curve image, displays the generated curve lane image on the display, and the display control unit reduces the first angle range when the vehicle speed is slow compared to when the vehicle speed is fast. Claim 4 A lane display device according to claim 1 or 2, wherein the display control unit acquires a first reference radius of curvature based on the curvature of the curve lane around the vehicle based on the acquired curve information, adjusts the first reference radius of curvature so that the first reference radius of curvature becomes longer when the vehicle speed is slow compared to when the vehicle speed is fast, generates the curve lane image based on the adjusted first reference radius of curvature, and displays the generated curve lane image on the display. Claim 5 A lane display device according to any one of claims 1 to 4, further comprising a gaze height acquisition unit for acquiring the gaze height of the driver of the vehicle, and the display control unit, wherein when the acquired gaze height of the driver is low, the degree of curvature of the displayed curve lane image is reduced compared to when the gaze height is high. Claim 6 In claim 5, the display control unit makes the curvature of the curve lane image displayed on the display proportional to the driver's line of sight height, and the lower the line of sight height, the smaller the curvature of the curve lane image. Claim 7 A lane display device according to claim 5 or 6, wherein the display control unit generates a second reference curve image based on the curvature of the curve lane around the vehicle based on the acquired curve information, extracts an image of a predetermined second angle range according to the curve from the generated second reference curve image, enlarges the extracted second reference curve image to a predetermined display size, generates the curve lane image based on the curve curvature of the enlarged second reference curve image, displays the generated curve lane image on the display, and the display control unit reduces the second angle range when the driver's line of sight is low compared to when the line of sight is high. Claim 8 A lane display device according to claim 5 or 6, wherein the display control unit acquires a second reference radius of curvature based on the curvature of the curve lane around the vehicle based on the acquired curve information, adjusts the second reference radius of curvature so that the second reference radius of curvature becomes longer when the driver's line of sight is low compared to when the line of sight is high, generates the curve lane image based on the adjusted second reference radius of curvature, and displays the generated curve lane image on the display.

Images