JP2011199400A - Vehicle periphery display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle periphery display device which can understandably tell existence of an obstacle object by visual recognition of an image.SOLUTION: A vehicle backward display device 100 which displays an image 1 of a backward area 93 of a vehicle 90 on a liquid crystal display 80, is provided with: a camera 60 and a decoder 70 which photograph the backward area 93 and generate a backward image 3; a plurality of sonars 20r, 20c, 20l arranged on the lateral sides of the vehicle 90 respectively, which detect the obstacle object 97 in the backward area 93 of the vehicle 90 on a detection plane DP; an arithmetic unit 10 which calculates a position BP of a projection point that the obstacle object 97 is projected on the detection plane DP based on the detection result, and a distance BD from the detection plane DP to the obstacle object 97; and a drawing device 40 which draws the image 1 by overlapping an alarm image 5 on the backward image 3, specifies a display position in a horizontal direction of the backward image 3 in the image 1 corresponding to the position BP, and reduces a distance of upward and downward directions of the alarm image 5 according to reduction of the distance BD.

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 plurality of distance sensors, and an alarm image indicating an obstacle in the external image is superimposed on an external image captured by the camera based on detection by the distance sensor. And display.

  It is presumed that the plurality of distance sensors provided in the device of Patent Document 1 are arranged at predetermined intervals in the lateral direction of the vehicle behind the vehicle. In addition, in this apparatus, the image displayed on the display is divided in advance in the horizontal direction according to the number of distance sensors. One area in this image is set so as to correspond to the detection area of one distance sensor in the vehicle external field area.

  In the above configuration, when there is an obstacle in the detection area of any distance sensor, the distance sensor detects the obstacle. The apparatus superimposes and displays an alarm image on an area on the image corresponding to the detection area of the distance sensor that detected the obstacle. The vertical length of the alarm image in the image displayed on the display is based on the detection of the distance sensor, and is reduced as the distance to the obstacle decreases. By displaying the alarm image as described above, the apparatus can show the position of the obstacle in the horizontal direction and the distance to the obstacle in the front-rear direction to a person who has viewed the image on the display.

JP 2008-539111 A

  In general, the detection areas of the distance sensors arranged in the lateral direction of the vehicle have an overlapping portion between adjacent distance sensors. Therefore, in the apparatus disclosed in Patent Document 1, two distance sensors may detect one obstacle. Therefore, even if there is only one obstacle (refer to the obstacle 10 in Patent Document 1 FIG. 2a), a plurality of alarm images (see the broken lines displayed in each of the region 1 and the region 2 in Patent Document 1 FIG. 2a) ) Will be displayed. As described above, since two warning images are displayed for one obstacle, the image displayed on the display may not be able to easily convey the presence of the obstacle.

  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 that is mounted on a vehicle and displays an image of the outside world area of the vehicle on a display device, the outside world area is imaged to generate an outside world image. Based on the detection results of the imaging means, a plurality of detection means arranged in the lateral direction of the vehicle on a predetermined detection plane, each detecting an obstacle in the outside world region, and the detection results by the plurality of detection means The calculation means for calculating the position in the lateral direction of the projection point projected on the plane and the distance from the detection plane to the obstacle in the front-rear direction, and an alarm image indicating the obstacle in the outside image are superimposed on the outside image. By this means, a means for drawing an image displayed by the display device, the horizontal display position of the alarm image in the image is defined corresponding to the position of the projection point, and the vertical length of the alarm image is defined. Characterized in that it and a drawing means for reducing with decreasing distance to the obstacle.

  In the present invention, the calculation means is based on the position of the projection point obtained by projecting the obstacle in the external area of the vehicle on the detection plane and the detection plane based on the detection results by the detection means arranged in the lateral direction of the vehicle. Calculate the distance to the obstacle. Therefore, even when two adjacent detectors of the plurality of detection means detect the obstacle, the calculation means can calculate the position of one projection point and the distance to the obstacle.

  In general, the lateral direction of the vehicle on the detection plane on which the detection means are arranged corresponds to the lateral direction of the image displayed on the display. Therefore, by defining the display position of the alarm image in the horizontal direction in the image of the display in correspondence with the position of the projection point on the detection plane in the horizontal direction of the obstacle, the alarm image is displayed in the outside image. It is drawn at a position corresponding to one obstacle, and the position of the obstacle can be shown. In general, the longitudinal direction of the vehicle corresponds to the vertical direction of the image displayed on the display. Therefore, as the distance from the detection plane to the obstacle in the front-rear direction decreases, the alarm image is reduced to one obstacle in the external image by reducing the vertical length of the alarm image in the display image. Can be shown.

  According to the above, one alarm image indicating the position of the obstacle in the lateral direction and the distance to the obstacle in the front-rear direction is superimposed on one obstacle on the image displayed by the display. The Therefore, the vehicle periphery display device can convey the presence of an obstacle in an easy-to-understand manner by visually recognizing the image on the display.

  In the invention according to claim 2, the calculation means stores in advance the interval value between adjacent detection means among the plurality of detection means, and when the adjacent detection means both detect an obstacle, these two The position of the projection point and the distance to the obstacle are calculated based on the distance value corresponding to the distance from the detection means to the obstacle and the interval value between the adjacent detection means.

  As in the present invention, by storing the interval value between the adjacent detection means in advance, the calculation means can determine the interval value between the adjacent detection means and each of these two detection means to the obstacle. Based on the distance value corresponding to the distance, the position of the projection point and the distance to the obstacle can be calculated. Thus, by knowing the length between each of the pair of adjacent detection means and the obstacle, the calculation means uses the trigonometric function to calculate the position of the projection point of the obstacle in the parallel direction of the detection means. The distance to the obstacle in the front-rear direction can be accurately calculated.

  As described above, the display position of the alarm image in the horizontal direction of the image on the display is defined based on the position of the projection point of the obstacle. Therefore, by improving the accuracy of the position of the projection point of the obstacle, the display position of the alarm image can accurately correspond to the position of the obstacle captured in the external image. In addition, by improving the accuracy of the distance to the obstacle in the front-rear direction, the height of the alarm image on the display image can accurately correspond to the position of the obstacle captured in the external image. .

  As described above, since the display position of the alarm image and the display position of the obstacle can accurately correspond to each other, the image displayed on the display can convey the presence of the obstacle more easily.

  In the invention according to claim 3, 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 captured in the external image toward the obstacle image. It is characterized by being superimposed on an external image.

  According to this invention, a part of the vehicle imaged by the imaging means is displayed on the image on the display. And if the warning image drawn by the drawing means is shaped to extend from the outer edge of the captured vehicle image toward the obstacle image, the warning image is displayed on the image of the display. Connect things. Therefore, the image displayed on the display can convey the distance from the vehicle to the obstacle more easily.

  According to a fourth aspect of the present invention, the alarm image is a strip having a width in the horizontal direction of the image displayed on the display.

  According to the present invention, even when the detecting means detects an obstacle having a narrow width in the horizontal direction, in the image displayed on the display, the alarm image indicating the obstacle has a width in the horizontal direction of the image on the display. Have Therefore, even if the obstacle displayed on the image on the display device is difficult to see with a narrow width in the horizontal direction, a belt-like alarm image having a width in the horizontal direction is displayed on the image on the display device. Therefore, the presence of an obstacle that is difficult to visually recognize is easily communicated.

  The invention according to claim 5 is characterized in that the alarm image is inclined closer to the center of the image in the horizontal direction as it goes to the upper side of the image displayed on the display device in the vertical direction.

  As in the present invention, according to the perspective method, in the external image captured by the imaging means, the further away from the vehicle in the front-rear direction, the closer to a specific point (so-called vanishing point) located at the center in the lateral direction of the external image. . Therefore, when the distance from the vehicle to the obstacle decreases, the display position of the obstacle in the image of the display device moves downward in the vertical direction and outward in the horizontal direction.

  On the other hand, by tilting the alarm image toward the center of the image displayed in the horizontal direction on the display, the alarm image whose height in the vertical direction decreases as the distance to the obstacle decreases, The position of the upper end in the vertical direction is moved outward in the horizontal direction.

  As described above, in the image displayed on the display device, the change in the shape of the alarm image corresponds to the change in the display position of the obstacle 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.

  According to a sixth aspect of the present invention, the image pickup means picks up an image of an external area behind the vehicle, and the detection means detects an obstacle in the external area behind the vehicle.

  According to this invention, the vehicle periphery display device displays an image obtained by superimposing an alarm image indicating an obstacle in the external area behind the vehicle on an external image obtained by imaging the external 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 6 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 6 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. 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 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 obtained by imaging a rear region 93 of the vehicle 90. In the rear image 3, the captured obstacle 97 is drawn as the obstacle image 7. The image 1 is drawn by superimposing a warning image 5 for emphasizing the obstacle image 7 on the rear image 3. By emphasizing the obstacle image 7 with the warning image 5, the image 1 can warn the driver of the presence of the obstacle 97 in the rear area 93 of the vehicle 90.

  In addition, in the rear image 3, a rear bumper 99 that is a part of the vehicle 90 is captured 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. Specifically, the position of the lower end of the alarm image 5 is fixed to the outer edge of the bumper image 9. On the other hand, the position of the upper end of the alarm image 5 moves along the longitudinal direction of the vehicle 90 corresponding to the distance from the rear bumper 99 to the obstacle 97. Thereby, when the distance from the vehicle 90 to the obstacle 97 is reduced, the height of the warning image 5 is reduced. The alarm image 5 has a strip shape having a width in the horizontal direction of the image 1. Furthermore, the warning 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, the configuration of the vehicle rear display device 100 for displaying the image 1 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 imaging means for imaging the rear area 93 of the vehicle 90, and has an angle of view Hα of, for example, about 160 degrees or more so that the rear area 93 can be imaged 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 image 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 detection means that detect the distance between the vehicle 90 and a three-dimensional object that becomes an obstacle 97 around the vehicle. 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 device 10, and the operation is controlled by the arithmetic device 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 device 10 includes, for example, a processor that performs various arithmetic processes, a ROM that stores information about programs and vehicles 90 used for the arithmetic processes, 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.

  The drawing device 40 obtains information that the position of the shift lever is in the reverse position from the arithmetic device 10 and does not obtain the position information of the obstacle 97, and the rear image continuously output from the decoder 70 3 is 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 the data of the alarm image 5 stored in advance in the memory 50. The drawing device 40 defines the shape and display position 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).

  Even when the obstacle 97 exists in a region where the detectable ranges of the sonar 20c and the sonar 20r overlap, similarly, the distance from the reference position to the position BP of the projection point and the distance from the detection plane DP to the obstacle 97 are the same. The distance BD can be calculated.

  The projection point position BP and the distance BD to the obstacle 97 described above are calculated by the calculation device 10 and acquired as detailed position information of the obstacle 97 by the drawing device 40.

  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 S <b> 60, based on the calculation result acquired from the calculation device 10, the position where the warning image 5 is superimposed on the rear image 3 and the height of the warning image 5 are defined by the drawing device 40. Specifically, in this embodiment, the image 1 is divided into a plurality in advance in the horizontal direction. The position of the obstacle image 7 in which the position of the obstacle image 7 is located in the horizontal direction of the image 1 is defined by the position BP of the projection point. Based on the position BP of the projection point, the alarm image 5 in the area corresponding to the position in the horizontal direction of the obstacle image 7 is displayed. Further, the length of the alarm image 5 in the vertical direction is defined corresponding to the distance BD.

  In step S70, the drawing device 40 superimposes the alarm image 5 on the rear image 3 based on the area where the alarm image 5 is displayed in the horizontal direction and the length in the vertical direction defined in step S60. Image 1 is drawn. The image data of the drawn image 1 is acquired by the liquid crystal display 80 and displayed on the liquid crystal display 80. In step S80, whether or not the position of the shift lever is in the reverse position is determined again by the arithmetic unit 10, and if it is in the reverse position, the control flow repeats steps S40 to S80. 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 arithmetic unit 10 detects the obstacle 97 in the rear region 93 of the vehicle 90 based on the detection results by the plural sonars 20r, 20c, 20l arranged in the lateral direction of the vehicle 90. Calculate detailed position. Therefore, even when two adjacent sonars 20r, 20c, and 20l detect the obstacle 97 with respect to one obstacle 97 in the rear region 93, the arithmetic unit 10 determines the position BP of one projection point. And the distance BD to the obstacle can be calculated.

  The lateral direction of the vehicle 90 on the detection plane DP on which the sonars 20r, 20c, and 20l are arranged corresponds to the lateral direction of the image 1 displayed on the liquid crystal display 80. Therefore, by defining the horizontal display position of the alarm image 5 in the image 1 in correspondence with the position BP of the projection point, the alarm image 5 is a position corresponding to the obstacle image 7 in which the obstacle 97 is drawn. Drawn on. As described above, the alarm image 5 can indicate the position of one obstacle 97 in the rear region 93.

  Further, the front-rear direction of the vehicle 90 corresponds to the up-down direction of the image 1 displayed on the liquid crystal display 80. Therefore, by reducing the vertical length of the alarm image 5 in the image 1 of the liquid crystal display 80 according to the decrease in the distance from the detection plane DP to the obstacle 97 in the front-rear direction, the alarm image 5 is displayed as the rear image 3. The distance BD to one obstacle 97 captured inside can be shown.

  According to the above, in the image 1 displayed by the liquid crystal display 80, the position of the obstacle 97 in the lateral direction and the distance to the obstacle 97 in the front-rear direction with respect to one obstacle 97 in the rear region 93. One alarm image 5 indicating is superimposed. Therefore, the vehicle rear display device 100 can inform the driver of the presence of 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, the arithmetic unit 10 includes the distance values SDr, SDl between the adjacent sonars 20r, 20c, 20l, and the distance values BDc, Based on BD1, the detailed position of the obstacle 97 can be calculated. Thus, by knowing the length between each of the pair of adjacent sonars 20c and 20l and the obstacle 97, the arithmetic unit 10 uses the trigonometric function to calculate the position BP of the obstacle projection point and the obstacle. The distance BD to the object can be accurately calculated.

  As described above, the display position of the alarm image 5 in the horizontal direction of the image 1 is defined based on the position BP of the projection point of the obstacle 97. Therefore, by improving the accuracy of the position BP of the projection point of the obstacle 97, the display position of the alarm image 5 can accurately correspond to the position of the obstacle image 7 in the rear image 3. In addition, since the accuracy of the distance BD to the obstacle 97 in the front-rear direction is improved, the length of the alarm image 5 in the vertical direction can accurately correspond to the position of the obstacle image 7 in the rear image 3. .

  As described above, since the display position of the alarm image 5 and the display position of the obstacle image 7 can accurately correspond to each other, the image 1 displayed on the liquid crystal display 80 conveys the presence of the obstacle 97 in an easy-to-understand manner. be able to.

  In the present embodiment, even when the sonars 20r, 20c, and 20l detect the obstacles 97 that are narrow in the lateral direction of the vehicle 90, the alarm image 5 is displayed in the lateral direction in the image 1 displayed on the liquid crystal display 80. , One area wide. Therefore, even if the obstacle image 7 displayed on the image 1 of the liquid crystal display 80 is narrow and difficult to visually recognize, the belt-like alarm image 5 having a predetermined width in the horizontal direction is displayed. Therefore, the presence of a narrow obstacle 97 that is difficult to visually recognize is easily communicated to the driver.

  Furthermore, in the present embodiment, the alarm image 5 connects the bumper image 9 and the obstacle image 7 on the image 1 by making the alarm image 5 extend from the bumper image 9 toward the obstacle image 7. (In FIG. 3, the image of the alarm image 5 displayed in the image 1 is indicated by a two-dot chain line). 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 this embodiment, according to the perspective method, the rear image 3 is closer to a specific point (so-called vanishing point) located at the center in the lateral direction of the rear image 3 as the distance from the vehicle in the front-rear direction is increased. (In the image 1 in FIG. 2, the vanishing point is located further above the upper end of the image 1.) Therefore, when the distance BD from the vehicle 90 to the obstacle 97 decreases, in the image 1 of the liquid crystal display 80. The display position of the obstacle image 7 moves downward in the vertical direction and outward in the horizontal direction.

  Therefore, by inclining the alarm image 5 toward the center of the image 1 in the horizontal direction of the image 1, the alarm image 5 whose length in the vertical direction decreases as the distance BD to the obstacle 97 decreases, The position of the upper end in the vertical direction is moved outward in the horizontal direction. As described above, the change in the shape of the alarm image 5 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 in the image 1. Therefore, the image 1 displayed on the liquid crystal display 80 can convey the distance BD to the obstacle 97 more intuitively.

  In this embodiment, the vehicle rear display device 100 displays the image 1 in which the alarm image 5 indicating the obstacle 97 in the rear region 93 is superimposed on the rear image 3 obtained by imaging the rear region 93 behind the vehicle. This is displayed on the 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 “outside image” described in the claims, the calculation device 10 is the “calculation means” described in the claims, and the sonars 20r, 20c, 20l are described in the claims. In the “detection means”, the drawing device 40 is in the “drawing means” described in the claims, the camera 60 and the decoder 70 are in the “imaging means” in the claims, and the rear area 93 is the “external area” in the claims. Further, the vehicle rear display device 100 corresponds to the “vehicle peripheral display device” recited 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 an image captured by one camera 60, but an image captured by a plurality of cameras may be used. Further, the configuration as the imaging means described in the claims is not limited to the camera 60, and various imaging means can be used.

  In the above-described embodiment, as the detection means for detecting the obstacle 97, a sonar using ultrasonic waves has been described as an example. However, as long as the distance from the obstacle 97 can be detected, the detection means is not limited to the sonar described above. Also, 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 that can be image-processed may be mounted on 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, the detailed position of the obstacle 97, specifically, the position BP of the projection point and the distance BD to the obstacle 97 may not be calculated using a trigonometric function. For example, the distance BD to the obstacle 97 may be calculated by averaging the distance values from each sonar to the obstacle 97. As long as detection results are output from a plurality of sonars and the detection results are integrated and output as position information of one obstacle 97, a specific method of calculation processing by the calculation device 10 is not limited.

  In the above embodiment, the virtual detection plane DP is defined on the plane on which the sonars 20r, 20c, and 20l are arranged, and the sonar 20c that is located in the center in the horizontal direction is set as the reference position in the horizontal direction on the detection plane DP. . However, the detection plane DP and the reference position BP on the detection plane DP are not limited to those described above, and may be changed as appropriate.

  In the above embodiment, the image 1 is divided into a plurality of parts in the horizontal direction, and the alarm image 5 of one area corresponding to the position BP of the projection point is displayed. 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, an example in which a belt-like image inclined toward the center of the screen in the horizontal direction is used as the alarm image 5 is described. However, the shape of the alarm image is not limited. For example, an alarm image having an arrow shape extending from the bumper image 9 to the obstacle image 7 may be used. Alternatively, it may be a fan-shaped alarm image whose width increases as it extends from the bumper image 9 to the obstacle image 7. Further, the alarm image may not be inclined toward the center of the screen. Furthermore, the bumper image may be omitted.

  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 SDr, 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 Angle, 1 image, 3 Rear image (outside image), 5 Alarm image, 7 Obstacle image, 9 Bumper image, 10 Arithmetic unit (calculating unit), 20r, 20c, 20l Sonar (detecting unit), 40 Drawing device (drawing) Means), 50 memory, 60 camera (imaging means), 70 decoder (imaging means), 80 liquid crystal display (display), 90 vehicle, 93 rear area (outside area), 97 obstacle, 99 rear bumper, 100 rear of vehicle Display device (vehicle periphery display device)

Claims (6)

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 imaging the external area and generating an external image;
A plurality of detection means arranged in a lateral direction of the vehicle on a predetermined detection plane, each detecting an obstacle in the outside world region;
An operation for calculating a position in the lateral direction of a projection point obtained by projecting the obstacle on the detection plane and a distance from the detection plane to the obstacle in the front-rear direction based on detection results by the plurality of detection means. Means,
A means for rendering the image displayed by the display device by superimposing an alarm image indicating the obstacle in the external image on the external image, the image being displayed in the lateral direction of the alarm image in the image The vehicle periphery display, comprising: a drawing unit that defines a display position corresponding to the position of the projection point and reduces the vertical length of the alarm image according to a decrease in the distance to the obstacle. apparatus.   The calculation means stores in advance an interval value between adjacent detection means of the plurality of detection means, and when both of the adjacent detection means detect the obstacle, the two detection means The position of the projection point and the distance to the obstacle are calculated based on the distance value corresponding to the distance to the distance and the interval value between the adjacent detection means. Vehicle periphery display device. A part of the vehicle is captured in the external image,
The said drawing means superimposes the said warning image extended toward the image of the said obstacle from the outer edge of the said image of the said vehicle imaged to the said external image on the said external image, It is characterized by the above-mentioned. The vehicle periphery display apparatus of description.   4. The vehicle periphery display device according to claim 1, wherein the alarm image has a band shape having a width in the horizontal direction of the image displayed on the display. 5.   5. The alarm image according to claim 1, wherein the alarm image is inclined toward the center of the image in the horizontal direction toward the upper side of the image displayed on the display device in the vertical direction. The vehicle periphery display device according to one item. The imaging means images an external area behind the vehicle,
The vehicle periphery display device according to any one of claims 1 to 5, wherein the detection unit detects an obstacle in an external area behind the vehicle.

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