JP5310616B2 - Vehicle periphery display device - Google Patents

Description

  The present invention relates to a vehicle periphery display device that is mounted on a vehicle and displays an image of an external area of the vehicle on a display.

  Conventionally, an alarm image indicating an obstacle in the external area captured in the external image is superimposed on an external image of the vehicle external area captured by a camera, and displayed on a display directed to the driver The device is known. As one type of such a display device, there is a device disclosed in Patent Document 1. The apparatus disclosed in Patent Document 1 includes a distance sensor that detects an obstacle in the external field and measures the distance from the vehicle to the obstacle. Here, in general, the display position of the obstacle image in the external area captured in the external image moves downward on the image of the display device as the vehicle approaches the obstacle. Therefore, in the apparatus described in Patent Document 1, the alarm image is defined based on the distance to the obstacle measured by the distance sensor in the vertical length of the image displayed on the display (Patent Document). 1 (see broken lines displayed in each of region 1 and region 2 in FIG. 2a). Therefore, when the distance to the obstacle measured by the distance sensor is reduced, the length of the alarm image in the vertical direction is reduced, so that the distance to the obstacle can be intuitively shown.

JP 2008-539111 A

  In the apparatus described in Patent Document 1, as described above, when the distance from the vehicle to the obstacle is reduced, the length of the alarm image is reduced in the vertical direction, and thus the size of the alarm image is reduced on the display image. Therefore, the alarm image is difficult to be visually recognized on the display device. According to the above, even if the alarm image can intuitively indicate the distance to the obstacle, it is difficult to visually recognize the obstacle image, so that the information on the obstacle is easily communicated to the driver or the like. There were cases where it was impossible.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a vehicle periphery display device that can easily convey the presence of an obstacle by visual recognition of an image.

  In order to achieve the above object, according to the first aspect of the present invention, in a vehicle peripheral display device mounted on a vehicle and displaying an image of the external area of the vehicle on a display, the external area is photographed. An imaging unit that generates an external image including an obstacle image representing an obstacle in the region, a detection unit that detects an obstacle in the external region and calculates the distance from the vehicle to the obstacle, and the detection unit is in the external region A drawing means for drawing an image to be displayed on the display device by superimposing an alarm image warning the presence of an obstacle corresponding to the obstacle image included in the external image when the obstacle is detected on the external image The alarm image is drawn in a frame shape by detecting an obstacle, and the vertical image length in the display image is fixed in advance, and is drawn in the frame image portion. Calculated obstacle Characterized in that it comprises a and a distance display image portion to be reduced in length in the vertical direction as the distance is reduced in.

  According to the present invention, in the alarm image, the frame-shaped frame image portion drawn by detecting the obstacle has a fixed vertical length in the display image. Therefore, even if the distance from the vehicle to the obstacle calculated by the detection means is reduced, the length in the vertical direction does not change. As described above, the alarm image including the frame image portion can maintain a state where it can be easily viewed.

  On the other hand, the distance display image portion drawn in the frame image portion of the alarm image is reduced in length in the vertical direction as the distance to the obstacle calculated by the detecting means is reduced. Can be shown intuitively. As described above, the alarm image including the distance display image portion can easily indicate the distance to the obstacle.

  According to these, the alarm image including the frame image portion and the distance display image portion can easily show the distance to the obstacle while maintaining a state where it is easily visible. Therefore, the vehicle periphery display device can convey information on the obstacle in an easy-to-understand manner by visually recognizing the image on the display.

  In the invention according to claim 2, the alarm image includes a dividing line image portion that divides the distance display image portion into a plurality of sections in the vertical direction, and the distance display image portion divided by the dividing line image portion is drawn by the drawing unit. By determining whether or not drawing is performed for each section, when the distance to the obstacle is reduced, drawing is stopped in order from the section located on the upper side in the vertical direction.

  According to the present invention, whether or not the distance display image portion divided by the dividing line image portion is drawn on the image of the display is determined for each section by the drawing means. And if the distance from a vehicle to an obstruction reduces, a distance display image part will be stopped in order from the division located in an upper side among several divisions. Thereby, the distance display image part can emphasize and show the change of the distance from a vehicle to an obstacle by reducing in steps on the image displayed on a display. Therefore, the vehicle periphery display device can indicate the distance to the obstacle more easily.

  The invention according to claim 3 is characterized in that the frame image portion has a fan shape whose length in the horizontal direction increases toward the upper side of the external image displayed on the display device in the vertical direction.

  Generally, as the obstacle moves away from the vehicle, the display position of the obstacle image corresponding to the obstacle in the outside image is a specific point (so-called vanishing point) located at the center in the lateral direction of the outside image according to the perspective method. Proximity to. In addition, as the obstacle image moves away from the vehicle, the display position moves upward and the display size becomes smaller.

  Therefore, even if an obstacle image corresponding to a distant obstacle displayed above the external image is enlarged by extending the horizontal length of the frame image portion toward the upper side of the display image, the frame The image portion can be emphasized by compensating for the small size of the obstacle image. Therefore, the vehicle periphery display device is far away from the vehicle, and even if it is an obstacle that is difficult to perceive in the image of the display device, the presence of the obstacle is easily communicated to the viewer.

  The invention according to claim 4 is characterized in that the alarm image is inclined toward the center of the image in the horizontal direction as it goes upward of the external image displayed on the display device in the vertical direction.

  When the distance from the vehicle to the obstacle decreases in the external image by the perspective method as described above, the display position of the obstacle in the display image moves obliquely downward in the vertical direction and outward in the horizontal direction. . By tilting the alarm image toward the center of the image in the horizontal direction of the image displayed on the display as in the present invention, the distance in which the vertical length decreases as the distance to the obstacle decreases. The display image part moves the position of the upper end diagonally outward in the horizontal direction.

  As described above, in the image displayed on the display, the change in the shape of the distance display image portion corresponds to the change in the display position of the obstacle image caused by the change in the distance from the vehicle to the obstacle. Therefore, the image displayed on the display device can more intuitively convey the distance to the obstacle.

  In the invention according to claim 5, a part of the vehicle is captured in the external image, and the drawing unit displays the alarm image extending from the outer edge of the vehicle image included in the external image toward the obstacle image. It is characterized by being superimposed on.

  According to the present invention, a part of the vehicle photographed by the imaging means is displayed on the image on the display. Then, if the warning image drawn by the drawing means has a shape extending from the outer edge of the vehicle image toward the obstacle image, the warning image is the vehicle image and the obstacle image on the display image. Connect with. Therefore, the image displayed on the display can convey the distance from the vehicle to the obstacle more easily.

  In the invention according to claim 6, the detection means is arranged in a lateral direction of the vehicle on a predetermined detection plane, and each of the detection units detects an obstacle in the external area, and the detection result by the plurality of detection units. And a computing unit that computes a position in the horizontal direction of the projection point at which the obstacle is projected onto the detection plane, along with the distance to the obstacle, and the drawing means includes the horizontal direction of the alarm image in the image. The display position is defined corresponding to the position of the projection point.

  According to the present invention, the detection means projects the obstacle on the detection plane based on the detection results of the plurality of detection units by arranging the plurality of detection units in the horizontal direction on the predetermined detection plane. It is possible to cause the calculation unit to calculate the position of the projection point in the horizontal direction. Then, according to the fact that the horizontal display position of the warning image drawn by the drawing means is defined corresponding to the position of the projection point, the warning image corresponds to the obstacle image drawn in the external image. It is accurately drawn at the position, and the presence of the obstacle can be reliably shown. As described above, since the display position of the alarm image and the display position of the obstacle image can accurately correspond in the horizontal direction, the image displayed on the display device can convey the presence of the obstacle more easily. it can.

  According to a seventh aspect of the present invention, the imaging means captures an external area behind the vehicle, and the detecting means detects an obstacle in the external area behind the vehicle.

  According to this invention, the vehicle periphery display device displays an image in which an alarm image indicating an obstacle in the external field area behind the vehicle is superimposed on an external image obtained by capturing the external field area behind the vehicle on the display. Obstacles behind the vehicle are not easily seen by the driver. Therefore, the vehicle periphery display apparatus like the invention of Claim 7 can support a driver | operator's driving operation reliably by exhibiting the effect of the said apparatus which can convey an obstruction easily. Therefore, the invention according to claim 7 is particularly suitable as a vehicle periphery display device that can effectively support the driving operation of the driver.

1 is a configuration diagram schematically showing a configuration of a vehicle rear display device according to an embodiment of the present invention. It is a figure for demonstrating the image displayed by the vehicle rear display apparatus by one Embodiment of this invention, Comprising: (a) Image of the state from which a vehicle and the obstacle are fully separated, (b) (a) It is a figure which shows an image when a vehicle and an obstruction approach from the state of. It is a figure for explaining in detail how a vehicle back display device by one embodiment of the present invention computes a detailed position of an obstacle. It is a flowchart which shows the control flow by one Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a configuration diagram schematically showing the configuration of a vehicle rear display device 100 according to an embodiment of the present invention. FIG. 2 is a diagram showing an image 1 displayed on the liquid crystal display 80 by the vehicle rear display device 100. The vehicle rear display device 100 is an embodiment of a vehicle periphery display device, and allows the driver who operates the vehicle 90 (see FIG. 3) to visually recognize the image 1 displayed on the liquid crystal display 80, thereby the driver. Assist driving operation.

  First, the image 1 displayed on the liquid crystal display 80 is demonstrated based on FIG. 2 and FIG.

  When the driver moves the vehicle 90 backward, the image 1 is displayed on the liquid crystal display 80 when an obstacle 97 exists in the rear region 93 of the vehicle 90. This image 1 is mainly composed of a rear image 3 formed by imaging a rear region 93 of the vehicle 90. The rear image 3 includes an obstacle image 7 in which the obstacle 97 present in the rear region 93 is captured and represents the obstacle 97. By superimposing the alarm image 5 that warns the presence of the obstacle 97 corresponding to the obstacle image 7 by emphasizing the obstacle image 7 on the rear image 3, the image 1 is drawn. By warning the presence of the obstacle 97 by the warning image 5, the image 1 can make the driver perceive the obstacle 97 existing in the rear area 93 of the vehicle 90.

  Next, the configuration of the vehicle rear display device 100 will be described with reference to FIGS. 1 and 3. The vehicle rear display device 100 includes a camera 60, a decoder 70, a plurality of sonars 20r, 20c, 20l, an arithmetic device 10, a memory 50, a drawing device 40, and the liquid crystal display 80 described above.

  The camera 60 is a part of an imaging unit that captures the rear region 93 of the vehicle 90, and has a field angle Hα of, for example, about 160 degrees or more so that the rear region 93 can be captured over a wide range. Yes. The camera 60 is installed above the rear bumper 99 of the vehicle 90 so that the rear of the vehicle 90 faces. The direction of the shooting direction of the camera 60 is along the front-rear direction of the vehicle 90. The photographing direction has an elevation angle and is directed to the ground side of the rear region 93. The camera 60 outputs the captured video of the rear area 93 in the NTSC system, which is one of analog video transmission standards.

  The decoder 70 is an integrated circuit that can convert an analog video signal into digital information. Specifically, the video signal of the rear area 93 input from the camera 60 is converted into image data of the digital rear image 3. Thus, the image data of the rear image 3 generated by the decoder 70 is continuously output to the drawing device 40.

  The sonars 20r, 20c, and 20l are a part of detection means that detects and calculates the distance from the vehicle 90 to a three-dimensional object or the like that becomes an obstacle 97 around the vehicle 90. Each of the sonars 20r, 20c, and 20l is an ultrasonic sensor, for example, and is arranged on the rear bumper 99 of the vehicle 90 at a predetermined interval in the lateral direction of the vehicle 90. The sonars 20r, 20c, and 20l are embedded in the rear bumper 99 so that the portions that transmit and receive ultrasonic waves are exposed to the rear bumper 99. These sonars 20r, 20c, and 20l are connected to the arithmetic unit 10 and their operation is controlled by the arithmetic unit 10. Each sonar 20r, 20c, 20l scans the rear area 93 of the vehicle 90 based on a command from the arithmetic unit 10. When the obstacle 97 exists within the detection range of each sonar 20r, 20c, 20l, a detection result corresponding to the distance from each sonar 20r, 20c, 20l to the obstacle 97 is output to the arithmetic unit 10. .

  The arithmetic unit 10 constitutes a detecting means for calculating the distance from the vehicle 90 to the obstacle 97 together with the sonars 20r, 20c, 20l and the like. The arithmetic device 10 includes, for example, a processor that performs various arithmetic processes, a ROM that stores programs used for the arithmetic processes, information on the vehicle 90, and the like, and a RAM that functions as a calculation work area. In addition, the arithmetic device 10 has a communication interface for acquiring information from an in-vehicle local area network (in-vehicle LAN) mounted on the vehicle 90. When the driver switches the position of the shift lever of the transmission to the reverse position, information on the shift position is output on the in-vehicle LAN from an engine control device or a transmission control device (not shown) connected to the in-vehicle LAN. Is done. The arithmetic unit 10 can acquire information that the position of the shift lever has been switched to the reverse position from the in-vehicle LAN. When the arithmetic device 10 acquires this information, it operates each of the sonars 20r, 20c, 20l to start the detection of the obstacle 97, and also outputs information indicating that the shift lever is in the reverse position to the drawing device 40. To do. When the obstacle 97 exists in the rear region 93 and the obstacle 97 is detected by these sonars 20r, 20c, 20l, the arithmetic unit 10 determines the obstacle 97 based on the detection results of the sonars 20r, 20c, 20l. The detailed position information is calculated. The detailed position information of the obstacle 97 is output to the drawing device 40.

  As the memory 50, a flash memory which is a kind of nonvolatile semiconductor memory is used. In the memory 50, image data of the alarm image 5 required for drawing the alarm image 5 (see FIG. 2) on the image 1 is stored in advance. The memory 50 causes the drawing device 40 to acquire the image data of the alarm image 5 in response to a request from the drawing device 40.

  The drawing device 40 includes a processor that performs image processing, a ROM that stores a program used for image processing, and a RAM that functions as a work area for calculation, and draws the image 1 displayed on the liquid crystal display 80. To do. Image 1 data of the image 1 drawn by the drawing device 40 is continuously output to the liquid crystal display 80.

  When the drawing device 40 acquires information that the position of the shift lever is in the reverse position and does not acquire the position information of the obstacle 97 from the arithmetic device 10, the rear image 3 continuously output from the decoder 70. Are drawn as an image 1 displayed on the liquid crystal display 80. When the position information of the obstacle 97 is acquired from the arithmetic device 10 from this state, the drawing device 40 acquires image data required for drawing the alarm image 5 stored in advance in the memory 50. The drawing device 40 defines the display position and shape of the alarm image 5 based on the acquired position information of the obstacle 97. In the present embodiment, the image 1 is drawn by superimposing the warning image 5 on the rear image 3 based on the definition. The image data of the image 1 drawn by the drawing device 40 is output to the liquid crystal display 80.

  The liquid crystal display 80 is a display device that is disposed in front of the steering wheel or in the center of the instrument panel, and is an interface that provides information to the driver by displaying an image 1. The liquid crystal display 80 acquires the image data of the image 1 drawn by the drawing device 40 and displays it so that the driver can visually recognize it. Since the image data of the image 1 is continuously output from the drawing apparatus 40 to the liquid crystal display 80, the liquid crystal display 80 displays the image 1 continuously. Thereby, the liquid crystal display 80 can display the situation of the back area 93 as a moving image to the driver.

  Next, the detailed position of the obstacle 97 calculated by the arithmetic device 10 based on the detection results of the sonars 20r, 20c, and 20l will be described in more detail with reference to FIGS.

  First, a plane that is orthogonal to the front-rear direction of the vehicle 90 and in which the sonars 20r, 20c, and 20l are arranged is predetermined as a detection plane DP. Further, the arithmetic unit 10 previously stores in the ROM the interval value SDr corresponding to the interval between the sonar 20r and the sonar 20c and the interval value SD1 corresponding to the interval between the sonar 20c and the sonar 20l in the lateral direction on the detection plane DP. I remember it.

  In the rear region 93, when the obstacle 97 exists in a region where the detectable ranges of the sonar 20c and the sonar 20l overlap, the adjacent sonar 20c and sonar 20l both detect the obstacle 97. Both the sonar 20c and the sonar 20l are output to the arithmetic unit 10 as a detection result. The computing device 10 calculates a distance value BDc corresponding to the distance from the sonar 20c to the obstacle 97 based on the detection result from the sonar 20c. In addition, the computing device 10 calculates a distance value BDl corresponding to the distance from the sonar 20l to the obstacle 97 based on the detection result from the sonar 20l.

  Further, the arithmetic unit 10 calculates the detailed position of the obstacle 97 based on these two distance values BDc, BDl and the interval value SDl. The detailed position of the obstacle 97 includes the position in the lateral direction of the projection point obtained by projecting the obstacle 97 from the rear of the vehicle along the longitudinal direction of the vehicle 90 onto the detection plane DP, and the obstacle 97 in the longitudinal direction from the detection plane DP. Distance BD is included.

  As a specific method for calculating the position BP of the projection point and the distance BD to the obstacle, in the present embodiment, calculation is performed using a trigonometric function based on the distance values BDc, BDl and the interval value SDl. Assuming that the position of the sonar 20c is the reference position in the horizontal direction in which the sonars 20r, 20c, and 20l are arranged, the distance BP1 from the reference position to the projection point position BP is BP1 = {(SD1) ^ 2 + (BDc) ^ 2- (BDl) ^ 2} / {2 × (SDl)}. The distance BD from the detection plane DP to the obstacle 97 can be calculated by the distance BD = {(BDc) ^ 2- (BP1) ^ 2} ^ (1/2).

  As described above, the position BP of the projection point on the detection plane DP and the distance BD from the detection plane DP defined on the outer edge of the vehicle 90 to the obstacle 97 are calculated by the calculation device 10, and the detailed position of the obstacle 97 is calculated. The information is acquired by the drawing apparatus 40 as information.

  With the configuration described so far, the characteristic part of the image 1 displayed on the liquid crystal display 80 will be described in more detail.

  The alarm image 5 includes a frame image portion 5a, a dividing line image portion 5b, and a distance display image portion 6.

  The frame image portion 5a is drawn in a frame shape on the image 1, and the vertical length of the image 1 is fixed in advance. In addition, the frame image portion 5a has a fan shape in which the length in the horizontal direction increases toward the upper side of the rear image 3 displayed on the liquid crystal display 80 in the vertical direction.

  The dividing line image part 5b is a line extending along the horizontal direction of the image 1, and a plurality of lines are drawn in the frame image part 5a with an interval in the vertical direction. The dividing line image unit 5b divides the distance display image unit 6 into a plurality of sections 6a to 6f in the vertical direction.

  The distance display image part 6 is drawn in the frame image part 5a, and the length in the vertical direction is reduced as the distance from the vehicle 90 to the obstacle 97 is reduced. In the present embodiment, the distance display image unit 6 is divided into a plurality of portions in the vertical direction by the dividing line image unit 5b, and it is determined whether or not the image is drawn on the image 1 for each of the sections 6a to 6f. Specifically, in the image 1, a priority order in which drawing is stopped from the uppermost section 6a is determined. As a result, when the distance BD to the obstacle 97 is reduced, the distance display image unit 6 stops drawing in order from the section 6a located on the upper side in the vertical direction, and reduces in the vertical direction.

  In addition, it is desirable that the distance display image unit 6 has a different hue, brightness, and saturation for each of the sections 6a to 6f. As an example, in this embodiment, when the distance BD from the vehicle 90 to the obstacle 97 is close, the section 6f that is continuously displayed until the end is drawn in red with high saturation. On the other hand, the section 6a displayed when the distance BD from the vehicle 90 to the obstacle 97 is the longest is drawn in white that is an achromatic color. And as for the divisions 6b-6d located between these divisions 6a to 6f, the saturation drawn is set so that it goes to the division 6d in order from the division 6b. The hue, brightness, and saturation of the sections 6a to 6f may be set as appropriate, and may be changed according to the driver's preference.

  Furthermore, it is desirable that the distance display image unit 6 is combined with the rear image 3 as a translucent image unit. Thereby, even when the distance display image unit 6 is superimposed on the obstacle image 7 included in the rear image 3, it is possible to suppress the occurrence of the situation where the obstacle image 7 is not visually recognized by the distance display image unit 6.

  In addition, in the rear image 3, a rear bumper 99 that is a part of the vehicle 90 is photographed and rendered as a bumper image 9. The warning image 5 extends from the outer edge of the bumper image 9 captured in the rear image 3 toward the obstacle image 7. The position of the lower end of the alarm image 5 is fixed to the outer edge of the bumper image 9. Further, the alarm image 5 is inclined closer to the center of the image 1 in the horizontal direction as it goes to the upper side of the image 1 in the vertical direction.

  Next, operation | movement of the vehicle rear display apparatus 100 at the time of parking the vehicle 90 from back is demonstrated, referring FIGS. 1-3 using the flowchart shown in FIG. This control flow starts when the accessory (ACC) power of the vehicle 90 is turned on to supply power to the arithmetic device 10, the drawing device 40, and the like. Further, this control flow ends when the ACC power supply of the vehicle 90 is turned off.

  In step S <b> 10, the ACC power supply of the vehicle 90 is turned on, so that an image (normal image) relating to the navigation system or the audio device is displayed on the liquid crystal display 80. In the next step S20, the arithmetic unit 10 determines whether or not the position of the shift lever is in the reverse position. When the shift lever is in the reverse position, the information is transmitted to the drawing device 40. In step S30, the drawing device 40 switches the display on the liquid crystal display 80 from the normal display such as the navigation described above to the display of the rear image 3 generated by the camera 60 and the decoder 70.

  In step S40, the arithmetic unit 10 operates each of the sonars 20r, 20c, and 20l, and acquires the detection results obtained by these. If there is an obstacle 97 in the rear region 93 of the vehicle 90, in step S50, the position BP of the projection point on the detection plane DP of the obstacle 97 and the distance BD in the front-rear direction from the detection plane DP to the obstacle 97 Is calculated by the arithmetic unit 10. This calculation result is output to the drawing device 40.

  In step S60, the drawing apparatus 40 sets the horizontal display position of the alarm image 5 in the image 1 displayed on the liquid crystal display 80 to the position BP of the projection point on the detection plane DP among the calculation results obtained from the calculation apparatus 10. Correspond and prescribe. Specifically, in the present embodiment, the image 1 is divided into a plurality of areas at predetermined intervals in the horizontal direction. The drawing device 40 defines, in the horizontal direction of the image 1, which of the plurality of areas into which the position where the alarm image 5 should be superimposed is divided corresponds to the projection point position BP.

  In step S <b> 70, the drawing device 40 indicates which of the plurality of sections 6 a to 6 f of the distance display image unit 6 should be drawn, and the distance from the detection plane DP to the obstacle 97 among the calculation results obtained from the calculation device 10. Judgment is made in correspondence with BD. For example, when the distance BD between the vehicle 90 and the obstacle 97 is large (see FIG. 2A), the drawing device 40 determines that all the sections 6a to 6f are drawn. On the other hand, when the vehicle 90 and the obstacle 97 come close to each other (see FIG. 2B), the drawing device 40 corresponds to the distance BD, does not draw the upper sections 6a to 6c, and is positioned below. It is determined that the sections 6d to 6f to be drawn are drawn.

  In step S80, the drawing device 40 sets the frame image portion 5a and the frame image unit 5a to correspond to the display position of the obstacle image 7 based on the definition of the area in which the alarm image 5 in the horizontal direction is displayed in step S60. The dividing line image portion 5b is drawn. The image data that is the basis of the frame image portion 5 a and the dividing line image portion 5 b is stored in the memory 50 in advance and is referred to by the drawing device 40. Furthermore, the drawing apparatus 40 draws a section corresponding to the distance BD to the obstacle 97 based on the determination whether or not each of the sections 6a to 6c is made in step S70. The image data that is the basis of the images of the sections 6a to 6f is also stored in the memory 50 in advance and is referred to by the drawing device 40. Then, the alarm image 5 including the frame image portion 5a, the dividing line image portion 5b, and the distance display image portion 6 is superimposed on the rear image 3, whereby the image 1 is drawn. The drawn image 1 is displayed on the liquid crystal display 80 when the image data is acquired by the liquid crystal display 80.

  In step S90, it is determined again by the arithmetic unit 10 whether or not the position of the shift lever is in the reverse position. If it is in the reverse position, the control flow repeats from step S40 to step S90. On the other hand, when the position of the shift lever is switched from the reverse position, the control flow returns to step S10.

  In the present embodiment described so far, the frame-shaped frame image portion 5a drawn by detecting the obstacle 97 in the alarm image 5 has a fixed vertical length in the image 1 in advance. Therefore, even if the distance BD from the vehicle 90 to the obstacle 97 calculated by the sonars 20r, 20c, 20l and the calculation device 10 is reduced, the length in the vertical direction does not change. As described above, the alarm image 5 including the frame image portion 5a can be maintained in a state where it can be easily viewed.

  On the other hand, the distance display image portion 6 drawn in the frame image portion 5a in the alarm image 5 is reduced in length in the vertical direction as the distance BD to the obstacle is reduced. BD can be shown intuitively. As described above, the alarm image 5 including the distance display image unit 6 can easily show the distance to the obstacle 97.

  According to these, the alarm image 5 including the frame image portion 5a and the distance display image portion 6 can easily show the distance BD to the obstacle 97 while maintaining a state where it is easily visible. Therefore, the vehicle rear display device 100 can convey the information on the obstacle 97 in an easy-to-understand manner by making the image 1 on the liquid crystal display 80 visible.

  In addition, in the present embodiment, when the distance BD from the vehicle 90 to the obstacle 97 is reduced, the distance display image unit 6 is stopped from drawing the plurality of sections 6a to 6f in order from the section 6a located on the upper side. Scale down step by step. As described above, the distance display image unit 6 is reduced in stages, so that the change in the distance BD to the obstacle 97 can be emphasized. Therefore, the vehicle rear display device 100 can more easily show the distance BD to the obstacle 97.

  In general, as the obstacle 97 moves away from the vehicle 90, the display position of the obstacle image 7 corresponding to the obstacle 97 in the rear image 3 is positioned at the center in the horizontal direction of the rear image 3 according to a perspective method. It is close to a specific point (so-called vanishing point, which is located further above the upper end of the image 1 in FIG. 2). In addition, as the obstacle 97 moves away from the vehicle 90, the display position of the obstacle image 7 moves upward and the display size becomes smaller.

  Therefore, in the present embodiment, the horizontal length of the frame image portion 5a is increased toward the upper side of the image 1 of the liquid crystal display 80, thereby corresponding to the distant obstacle 97 displayed above the rear image 3. Even in the case of the obstacle image 7, the frame image portion 5 a can emphasize the obstacle 97 by compensating for the small size of the obstacle image 7. Therefore, the vehicle rear display device 100 is distant from the vehicle 90 by a distance BD, and even if the obstacle 97 is difficult to perceive in the image 1 of the liquid crystal display 80, the presence of the obstacle 97 is easily communicated to the viewer.

  Further, in the present embodiment, when the distance BD from the vehicle to the obstacle 97 is reduced in the rear image 3 by the perspective method as described above, the display position of the obstacle 97 in the image 1 is lower in the vertical direction and laterally. Move diagonally toward the outside. As in the present invention, by tilting the alarm image 5 toward the center of the image 1 in the horizontal direction of the image 1, the distance display image whose length in the vertical direction decreases as the distance to the obstacle 97 decreases. The part 6 moves the position of the upper end outward in the lateral direction.

  As described above, in the image 1 displayed on the liquid crystal display 80, the change in the shape of the distance display image unit 6 corresponds to the change in the display position of the obstacle image 7 caused by the change in the distance BD from the vehicle 90 to the obstacle 97. . Therefore, the image 1 displayed on the liquid crystal display 80 can convey the distance BD to the obstacle 97 more intuitively.

  In addition, in the present embodiment, the rear bumper 99 which is a part of the vehicle 90 is photographed by the camera 60, so that the bumper image 9 corresponding to the rear bumper 99 is included in the rear image 1. Then, when the warning image 5 drawn by the drawing device 40 has a shape extending from the outer edge of the bumper image 9 toward the obstacle image 7, the warning image 5 is the same as the bumper image 9 on the image 1. The obstacle image 7 is connected. This makes it easier for the driver to intuitively grasp the relationship between the vehicle 90 and the obstacle 97 (the image of the alarm image 5 displayed in the image 1 is indicated by a two-dot chain line in FIG. 3). Therefore, the image 1 displayed on the liquid crystal display 80 can convey the distance from the rear bumper 99 of the vehicle 90 to the obstacle 97 more easily.

  In addition, in the present embodiment, by arranging a plurality of sonars 20r, 20c, and 20l in a lateral direction on a predetermined detection plane DP, based on detection results by the plurality of sonars 20r, 20c, and 20l, It is possible to cause the calculation device 10 to calculate the position BP in the horizontal direction of the projection point at which the obstacle 97 is projected onto the detection plane DP. Then, according to the fact that the horizontal display position of the warning image 5 drawn by the drawing device 40 is defined corresponding to the projection point position BP, the warning image 5 is drawn in the rear image 3. It is accurately drawn at a position corresponding to the obstacle image 7. Therefore, the alarm image 5 can reliably indicate the presence of the obstacle 97. As described above, since the display position of the alarm image 5 and the display position of the obstacle image 7 can accurately correspond in the horizontal direction, the image 1 displayed on the liquid crystal display 80 further indicates the presence of the obstacle 97. Can be communicated in an easy-to-understand manner.

  In the present embodiment, the vehicle rear display device 100 superimposes an alarm image 5 that warns the presence of the obstacle 97 in the rear region 93 on the rear image 3 obtained by imaging the rear region 93 behind the vehicle. Is displayed on the liquid crystal display 80. The obstacle 97 behind the vehicle 90 is difficult to be visually recognized by the driver. Therefore, the vehicle rear display device 100 as in the present embodiment can reliably support the driving operation of the driver by exhibiting the effect of the device that can easily convey the obstacle 97. Therefore, the vehicle rear display device 100 is particularly suitable as a vehicle periphery display device that can effectively support the driving operation of the driver.

  In the present embodiment, the rear image 3 is the “external world image” described in the claims, the calculation device 10 is the “calculation unit” described in the claims, and the sonars 20r, 20c, 20l are described in the claims. In the “detection unit”, the arithmetic device 10 and the sonars 20r, 20c, and 20l are in “detection means” in the claims, the drawing device 40 is in “drawing means” in the claims, and the camera 60 and the decoder 70 are in claims. The rear area 93 corresponds to the “outside area” described in the claims, and the vehicle rear display device 100 corresponds to the “vehicle peripheral display device” described in the claims.

(Other embodiments)
In the above-described embodiment, the preferred embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. It is possible.

  In the above embodiment, the vehicle rear display device is described as an example of the vehicle periphery display device, but the present invention is not limited to this embodiment. For example, when the vehicle moves forward from the front of the vehicle toward a space such as a parking space, the vehicle periphery display device may display a vehicle front area as the vehicle periphery. In this embodiment, a predetermined alarm image is displayed on the liquid crystal display 80 together with an image of the front area of the vehicle.

  In the above embodiment, the image displayed on the liquid crystal display 80 is mainly the rear image 3 captured by one camera 60 and the decoder 70, but is mainly an external image captured by a plurality of cameras. It may be. Further, the configuration used as the imaging means described in the claims is not limited to the camera 60, and various configurations can be used.

  In the above embodiment, the distance display image unit 6 is divided into a plurality of sections 6a to 6f by the dividing line image unit 5b, and is gradually reduced as the distance BD is reduced. However, the distance display image part 6 may be divided into a plurality of parts without depending on the dividing line image part 5b. Further, the distance display image unit 6 may continuously expand and contract in the vertical direction according to the distance BD, for example. In addition, the distance display image unit 6 may not be translucent so that the obstacle image 7 can be easily visually recognized.

  In the above embodiment, the frame image portion 5a is defined in a fan shape, but the shape is not limited, and for example, the frame image portion 5a is defined in a rectangular shape or a trapezoidal shape having a lower bottom shorter than the upper base. Also good. In addition, the dividing line image portion 5 b is linear along the horizontal direction of the image 1, but may be drawn with a broken line or the like, or may be curved along the outer edge of the bumper image 9.

  In the above-described embodiment, an example in which the alarm image 5 having a shape inclined toward the center of the screen in the horizontal direction has been described. However, the alarm image may not be inclined toward the center of the image 1. Further, the bumper image 9 may be omitted.

  In the above-described embodiment, as a detection unit that detects the obstacle 97, a sonar using ultrasonic waves has been described as an example. However, the detection unit is not limited to the above-described sonar as long as the distance from the obstacle 97 can be detected. Further, the number and arrangement of sonars are not limited to the above-described embodiment. For example, the number of sonars may be two, or four or more. In addition, the intervals between adjacent sonars need not be equal.

  In the above-described embodiment, the arithmetic processing and drawing processing related to the control flow are separately performed by the arithmetic device 10 and the drawing device 40. However, the configuration capable of performing the processing according to the present invention is not limited to the configuration of the above embodiment. The functions of “calculation means” and “drawing means” described in the claims may be incorporated as a functional block in an arithmetic device mounted on the vehicle 90. Alternatively, the functions of the “calculation means” and the “drawing means” may be incorporated as a functional block in one arithmetic device. Furthermore, the function of converting the analog signal of the camera 60 into a digital signal capable of image processing may be mounted as a functional block in another arithmetic unit instead of the dedicated decoder 70.

  In the above embodiment, the detailed relative position of the obstacle 97 with respect to the vehicle 90 is calculated using a trigonometric function based on the distance between adjacent sonars and the distance from each sonar to the obstacle. However, if the distance BD from the vehicle 90 to the obstacle 97 can be calculated, the configuration and the calculation method are not limited to those described in the above embodiment. Further, as a reference point on the vehicle 90 side for calculating the distance BD from the vehicle 90 to the obstacle 97, a virtual detection plane DP is defined on the plane on which the sonars 20r, 20c, and 20l are arranged, and the detection plane A projection point obtained by projecting an obstacle 97 on the DP was used. However, the reference point on the vehicle 90 side for calculating the distance BD to the obstacle 97 is not limited to the projection point on the detection plane DP described above, and may be changed as appropriate.

  In the above embodiment, the image 1 is divided into a plurality of areas in the horizontal direction, one area corresponding to the position BP of the projection point is defined, and the alarm image 5 is displayed in the area. However, the display position in the horizontal direction of the alarm image 5 may be defined in direct correspondence with the position BP of the projection point.

  In the above embodiment, the liquid crystal display 80 is described as an example of the “display” that displays the image 1, but the “display” is not limited to the liquid crystal display 80. For example, it may be a “display” using a Cathode Ray Tube (CRT) display or a Plasma Display Panel (PDP). Further, as the “display”, for example, a so-called Head-up Display (HUD) device that displays a virtual image of the image 1 on the windshield of the vehicle may be used.

BDc, BDl distance to obstacle, distance between SDc, SDl sonar, distance to BD obstacle, position of BP projection point, distance from BPl reference position to position of projection point, DP detection plane, Hα image Corner, 1 image, 3 Rear image (outside image), 5 Alarm image, 5a Frame image section, 5b Dividing line image section, 6 Distance display image section, 6a-6f section, 7 Obstacle image, 9 Bumper image, 10 Arithmetic Device (detection means), 20r, 20c, 20l sonar (detection means), 40 drawing device (drawing means), 50 memory, 60 camera (imaging means), 70 decoder (imaging means), 80 liquid crystal display (display), 90 vehicle, 93 rear region (outside region), 97 obstacle, 99 rear bumper, 100 vehicle rear display device (vehicle peripheral display device)

Claims (7)

In a vehicle periphery display device that is mounted on a vehicle and displays an image of an external area of the vehicle on a display device,
Imaging means for capturing the external area, and generating an external image including an obstacle image representing an obstacle in the external area;
Detecting means for detecting the obstacle in the external area and calculating a distance from the vehicle to the obstacle;
When the detection means detects the obstacle in the external area, by superimposing an alarm image warning the presence of the obstacle corresponding to the obstacle image included in the external image on the external image, Drawing means for drawing the image displayed on the display,
The warning image is
A frame image portion drawn in a frame shape by detection of the obstacle, and a vertical length in the image of the display device fixed in advance;
And a distance display image part that is drawn in the frame image part and is reduced in length in the vertical direction as the distance to the obstacle calculated by the detecting means is reduced. apparatus. The warning image includes a dividing line image portion that divides the distance display image portion into a plurality of sections in the vertical direction,
When the distance to the obstacle is reduced by determining whether or not the distance display image portion divided by the dividing line image portion is drawn for each of the sections by the drawing unit, The vehicle periphery display device according to claim 1, wherein the drawing is stopped in order from the section located on the upper side.   The said frame image part is a fan shape which the length of the said horizontal direction expands, so that it goes to the upper side of the said external field image displayed on the said display device in the said up-down direction. The vehicle periphery display apparatus of description.   The alarm image is inclined toward the center of the image in the lateral direction toward the upper side of the external image displayed on the display in the vertical direction. The vehicle periphery display apparatus as described in any one of Claims. A part of the vehicle is captured in the external image,
The said drawing means superimposes the said warning image extended toward the said obstacle image from the outer edge of the image of the said vehicle contained in the said external image on the said external image, The any one of Claims 1-4 characterized by the above-mentioned. The vehicle periphery display device according to one item. The detection means includes
A plurality of detection units arranged in a lateral direction of the vehicle on a predetermined detection plane, each detecting an obstacle in the outside world region;
A calculation unit that calculates a position in the lateral direction of a projection point obtained by projecting the obstacle on the detection plane together with a distance to the obstacle based on detection results by the plurality of detection units;
6. The vehicle periphery display according to claim 1, wherein the drawing unit defines a display position in a horizontal direction of the warning image in the image corresponding to the position of the projection point. apparatus. The imaging means captures an external area behind the vehicle,
The vehicle periphery display device according to any one of claims 1 to 6, wherein the detection unit detects the obstacle in an external area behind the vehicle.

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