JP5861449B2 - Obstacle alarm device - Google Patents

Description

  The present invention relates to an obstacle alarm device that clearly indicates to an occupant the presence of an obstacle approaching a vehicle.

  There are blind spots around the vehicle that cannot be seen from the position of the driver, and the driver needs to pay close attention to the periphery of the vehicle when driving the vehicle. In particular, when the vehicle is moved backward and parked, there are many users who are not good at parking itself, and there is not a lot of mental fatigue. Thus, conventionally, techniques for monitoring obstacles around the vehicle have been used (for example, Patent Documents 1 and 2).

  The vehicle obstacle alarm device described in Patent Document 1 includes a lateral movement obstacle detection means, a lateral movement direction detection means, and a lateral movement information provision means. The laterally moving obstacle detection means detects an obstacle that moves in the direction crossing the traveling direction in front of the vehicle. The lateral movement direction detection means detects the lateral movement direction of the obstacle detected by the lateral movement obstacle detection means. The lateral movement information providing means provides the driver with information regarding the lateral movement direction of the obstacle detected by the lateral movement direction detecting means. At this time, the lateral movement information providing means displays an arrow indicating the lateral movement direction detected by the lateral movement direction detecting means on the display unit.

  The vehicle surrounding monitoring apparatus described in Patent Document 2 includes an imaging unit, an obstacle detection unit, and a display unit. The imaging means images the surroundings of the vehicle including a part of the host vehicle. The obstacle detection means detects an obstacle located around the vehicle and calculates a distance between the detected obstacle and the host vehicle. The display unit displays the captured image captured by the imaging unit and the obstacle display image indicating the distance calculated by the obstacle detection unit on one screen.

Japanese Patent Application Laid-Open No. 11-115660 JP 2009-217740 A

  Obstacles around the vehicle are detected by detecting obstacles around the vehicle as in the techniques described in Patent Literature 1 and Patent Literature 2 and displaying information (arrows, etc.) clearly indicating the obstacles on the screen. Can be notified. However, the screen size of the display (display means) mounted on the vehicle is not large. For this reason, if an arrow or the like is displayed on the image showing the situation around the vehicle displayed on the display, the situation around the vehicle may become difficult to see or an obstacle may not be grasped.

  In view of the above problems, an object of the present invention is to provide an obstacle alarm device that can clearly indicate to the driver the presence of an obstacle approaching the vehicle without making it difficult to see the situation around the vehicle. is there.

In order to achieve the above object, the characteristic configuration of the obstacle alarm device according to the present invention is as follows:
A captured image acquisition unit that acquires a captured image of a scene behind the vehicle;
An attention-captured image generation unit that generates an attention-captured image based on the captured image;
A vehicle image image generation unit that generates a translucent vehicle image when the vehicle is viewed from behind,
An object presence determination unit that determines whether or not an object exists in an outer region outside the target captured image;
A moving direction determination unit that determines the moving direction of the object in the outer region;
An explicit image output unit that performs display to display the vehicle image at the center of the target captured image when the movement direction determination unit determines that the object in the outer region moves to the center of the target captured image When,
It is in the point equipped with.

  With such a characteristic configuration, even if an object is not shown in the monitor screen of the vehicle, the situation around the vehicle is displayed when an object approaching the vehicle enters the shooting range. The presence of an object approaching the vehicle can be clearly indicated to the occupant. For this reason, even when the screen size of the monitor is small, an object approaching the vehicle is not missed. Therefore, it is possible to clearly indicate to the occupant the presence of an object approaching the vehicle without missing an object around the vehicle.

  In addition, it is preferable that the explicit image output unit perform a display in which the vehicle image is moved from the center to the outer region side where the object exists in accordance with the movement of the object.

  With such a configuration, it is possible to clearly indicate that the object is approaching from the outside region to the vehicle side and the direction in which the object is approaching.

  Further, it is preferable that the explicit image output unit enlarges the vehicle image and displays it at the center when the object approaches the target captured image from both right and left sides.

  With such a configuration, it can be clearly shown that the object is approaching from both the left and right directions of the vehicle. Accordingly, it is possible to appropriately alert the passenger.

  In addition, the explicit image output unit includes a plurality of indicators that clearly indicate the movement of the object from the outer region side where the object is present to the center side of the target captured image toward the center side of the target captured image. Are sequentially displayed at different positions, and the index displayed later and the index displayed immediately before are preferably displayed so that the index displayed later is larger than the index displayed immediately before.

  With such a configuration, the direction of the object approaching the vehicle can be clearly indicated by the vehicle occupant. For this reason, even when the screen size of the monitor is small, an object approaching the vehicle is not missed.

  In addition, it is preferable that the explicit image output unit stops the display of the index and the own vehicle image when the object enters the noticeable captured image.

  With such a configuration, it can be clearly shown that the object has moved away from the vehicle. Therefore, it is possible to make the occupant recognize that the back of the vehicle is not watched more than necessary.

It is the block diagram which showed typically the structure of the obstacle alarm device. It is the figure which showed an example of the process of an obstacle alarm device. It is the figure which showed an example of the synthesized image. It is the figure which showed typically the process of the obstacle alarm device. It is the figure which showed the synthesized image which concerns on other embodiment.

  Hereinafter, embodiments of the present invention will be described in detail. The obstacle alarm device 100 according to the present invention has a function of clearly indicating that an object is approaching the driver of the vehicle when there is an object approaching the vehicle. Hereinafter, it demonstrates using drawing.

  FIG. 1 is a block diagram schematically showing the configuration of the obstacle alarm device 100. As shown in FIG. 1, the obstacle alarm device 100 includes a captured image acquisition unit 11, a focused captured image generation unit 12, an outer region generation unit 13, an object presence determination unit 14, a movement direction determination unit 15, and an explicit image output unit. 16, an explicit image storage unit 17, a composite image generation unit 18, and a vehicle image image generation unit 19. Each functional unit includes the above-described functional units for performing various processes for clearly indicating the approach of the object 7 to the driver of the vehicle 1 by using a CPU as a core member.

  The captured image acquisition unit 11 acquires a captured image G obtained by capturing a scene behind the vehicle 1. Here, the vehicle 1 is provided with a camera 5. The camera 5 according to the present embodiment includes a digital camera that incorporates an image sensor such as a charge coupled device (CCD) or a CMOS image sensor (CIS) and outputs captured information as moving image information. As shown in FIG. 2A, such a camera 5 is located behind the vehicle 1 in the vicinity of the license plate provided at the outer rear part of the vehicle 1 or in the vicinity of the emblem provided at the outer rear part of the vehicle 1. It is arrange | positioned with a slight depression angle toward. The camera 5 includes a wide-angle lens (not shown). Thereby, the scene around the vehicle 1 can be photographed over the rear of the vehicle 1 over approximately 180 degrees. Such an imaging range is shown as “wide viewing angle” in FIG. The camera 5 has a performance of outputting a moving image as a captured image G in real time. Such a captured image G is transmitted to the captured image acquisition unit 11.

  An example of such a captured image G is shown in FIG. The full width of FIG. 2 (b) corresponds to the wide viewing angle of FIG. 2 (a). Here, in the photographed image G, the object 7 on the left side as viewed from the rear of the vehicle 1 as shown in FIG. 2A is on the right side in the photographed image G as shown in FIG. Thus, mirror image processing is performed. This is because when the scene behind the vehicle 1 is displayed on the monitor 50, it is easy for the driver of the vehicle 1 to intuitively understand whether the object 7 included in the captured image G is on the left side or the right side of the vehicle 1. It is to do.

  Returning to FIG. 1, the noticeable photographed image generation unit 12 generates a noticeable photographed image based on the photographed image G. In the present embodiment, the shooting range of the shot image G is a wide viewing angle. For this reason, the noticeable photographed image generation unit 12 generates a narrow-field region N that is a central portion of the photographed image G as the noticeable photographed image. The captured image G is transmitted from the captured image acquisition unit 11 described above. In the present embodiment, the noticeable photographed image corresponds to the central portion in the horizontal direction of the photographed image G shown in FIG. Such a narrow visual field region N is preferably a region, for example, about 120 to 130 degrees behind the vehicle 1 like the “narrow visual field angle” in FIG. In addition, since the narrow-field region N is close to the advanceable range when the vehicle 1 moves backward, it is referred to as a “focused captured image” because it is a region that should be particularly noted in the captured image G. Such a noticeable photographed image corresponds to a display image displayed on the monitor 50 described later (see FIG. 2C). In the present embodiment, the “focused captured image” is described as an image of a “narrow field of view”.

  The outer area generation unit 13 generates an outer area O outside the target captured image. That is, an outer region O outside the narrow field region N in the captured image G is generated. As described above, the narrow-field region N is generated by the noticeable captured image generation unit 12 at the central portion in the horizontal direction of the captured image G. The outer region generation unit 13 generates an outer region O as shown in FIG. 2B outside the narrow visual field region N in the lateral direction. The outer region O generated by the outer region generation unit 13 is transmitted to an object presence determination unit 14 described later.

  The object presence determination unit 14 determines whether or not the object 7 exists in the outer region O. The outer region O is transmitted from the outer region generator 13. Whether or not the object 7 exists can be determined using a known image recognition process such as pattern matching. Of course, it is possible to determine whether or not the object 7 exists in the outer region O by processing other than pattern matching. The determination result of the object presence determination unit 14 is transmitted to a movement direction determination unit 15 described later.

  The movement direction determination unit 15 determines the movement direction of the object 7 in the outer region O. Such determination of the moving direction is performed when the object presence determination unit 14 determines that the object 7 exists in the outer region O. In particular, in this embodiment, the moving direction determination unit 15 determines whether or not the object 7 in the outer region O moves toward the narrow visual field region N. The movement toward the narrow visual field N indicates that the vehicle 1 moves from the outer side in the width direction of the vehicle 1 to the direction just behind the vehicle 1 behind the vehicle 1. Such a determination can be performed by comparing the position of the object 7 in the current captured image G with the position of the object 7 in the captured image G a predetermined time ago, for example, or by using an optical flow. It is possible to use this method. Such a determination result of the moving direction is transmitted to the explicit image output unit 16 described later.

  The own vehicle image image generation unit 19 generates a translucent own vehicle image image CI when the vehicle 1 is viewed from behind. The own vehicle image CI is an image when the vehicle 1 is viewed from directly behind. The host vehicle image CI is displayed in a superimposed manner on a noticed photographed image showing a scene behind the vehicle 1 as will be described later. Therefore, the host vehicle image image CI is generated with a predetermined transparency so that the scene behind the vehicle 1 at a position overlapping the host vehicle image image CI is not easily seen. The translucency is not limited to 50% transparency, but is such a transparency that at least a scene behind the vehicle 1 at a position overlapping the own vehicle image CI can be seen. The own vehicle image image CI generated by the own vehicle image image generation unit 19 is stored as an explicit image in the explicit image storage unit 17 and read by the explicit image output unit 16 described later.

  The explicit image output unit 16 displays the vehicle image image CI at the center of the noticeable photographed image when the movement direction judgment part 15 determines that the object 7 in the outer region O moves to the center of the noticeable photographed image. I do. As described above, the moving direction of the object 7 in the outer region O is determined by the moving direction determination unit 15. Therefore, the movement direction determination unit 15 can also determine whether or not the object 7 moves to the center side of the target captured image. On the other hand, the vehicle image image CI is transmitted from the vehicle image image generation unit 19. When it is determined that the object 7 in the outer region O moves to the center side of the target captured image, the explicit image output unit 16 displays the host vehicle image image CI at the center of the target captured image. Here, since the own vehicle image image CI is translucent, the portion of the noticeable photographed image that overlaps with the own vehicle image image CI, that is, the scene behind the vehicle 1 is not invisible. Therefore, even if the occupant of the vehicle 1 displays the vehicle image image CI superimposed on the noticeable photographed image, the scene behind the vehicle 1 is not lost.

  In addition, when the moving direction determination unit 15 determines that the object 7 in the outer region O moves to the center side of the target captured image, the explicit image output unit 16 includes the outer region O in which the object 7 exists in the target captured image. A plurality of indices S that clearly indicate the movement of the object 7 toward the center side of the target photographed image are sequentially displayed at different positions from the side toward the center side. Here, “from the outer region O side where the object 7 exists in the target captured image toward the center side” means that when the object 7 in the right outer region O exists, “from the right side to the center side”. When the object 7 in the left outer region O exists, it indicates “from the left side toward the center side”.

  Further, the explicit image output unit 16 increases the number of indices S according to the distance to the noticeable captured image. As a result, it is possible to clearly indicate to the occupant that the object 7 existing in the outer region O is approaching the center side of the target captured image. Such an index S is preferably configured in the shape of an arrow having a convex portion projecting toward the center of the target photographed image (narrow field of view region N), for example. This makes it possible to intuitively recognize the moving direction of the object 7. Furthermore, the index S can be configured to have a predetermined transparency in order to prevent the scene behind the vehicle 1 from being unrecognizable. Such an index S is preferably stored in the explicit image storage unit 17 as an explicit image as shown in FIG.

  Here, the plurality of indices S is configured such that the index S displayed later and the index S displayed immediately before are larger than the index S displayed immediately before. That is, when a plurality of indices S are displayed, the last superimposed index S has the largest size, and the first superimposed index S has the smallest size. Each index S may have a size similar to each other and may be set in size, or may be set in size by changing either the vertical or horizontal length of the index S. . By displaying in this way, it becomes possible for the passenger of the vehicle 1 to intuitively recognize that the object 7 is approaching as the size of the index S increases.

  In addition, the explicit image output unit 16 according to the present embodiment performs display in which the own vehicle image image CI is moved from the center of the target captured image toward the outer region O where the object 7 exists in accordance with the movement of the object 7. As described above, the number of indices S increases as the object 7 approaches the center side of the target captured image. In accordance with this, the own vehicle image CI is moved to the outer region O where the object 7 exists. That is, when the object 7 approaching the center side of the noticeable photographed image exists in the right outer area O, the host vehicle image image CI is moved to the right outer area O side, and the object approaching the center side of the noticeable photographed image. When 7 exists in the left outer region O, the vehicle image CI is moved to the left outer region O side. This movement may be performed in synchronization with the timing at which the index S is added. Thereby, it is possible to clearly indicate that the object 7 is gradually approaching the vehicle 1.

  The explicit image output unit 16 causes such display. Here, in the present embodiment, as shown in FIG. 2C, the vehicle image image CI and the index S are combined with a noticed captured image that is a narrow visual field N and displayed on the monitor 50. Therefore, the composite image generation unit 18 generates a composite image in which the vehicle image image CI and the index S are combined with the target captured image. As a result, an image as shown in FIG. 2C is generated. By displaying the vehicle image image CI and the index S in this way, it is possible to visually clearly indicate that the object 7 is approaching the vehicle 1 with respect to the passenger of the vehicle 1.

  The explicit image output unit 16 stops the display of the index S and the own vehicle image image CI when the object 7 enters the target captured image. Thereby, since the object 7 entered into the noticeable photographed image, it is possible to prompt the occupant of the vehicle 1 to watch further.

  An example of a series of images in which the vehicle image image CI and the index S are superimposed and displayed is shown in FIGS. 3 and 4. As shown in FIG. 3A, when it is detected that the object 7 in the outer region O has moved to the center side of the narrow field region N, the own vehicle image image CI is displayed at the center of the target photographed image. In addition to being displayed in a superimposed manner, an index S (hereinafter referred to as “S1”) is superimposed and displayed on the outer region O side where the object 7 is present in the target photographed image. When the object 7 further moves to the center side of the noticeable photographed image, the vehicle image image CI is moved to the outer region O side where the object 7 exists, and the index S larger than the index S1 previously displayed. (Hereinafter referred to as “S2”) is additionally displayed (FIG. 3B).

  Further, when the object 7 moves to the center side of the target photographed image, the vehicle image image CI is moved to the outer region O where the object 7 exists and is larger than the previously displayed indices S1 and S2. An index S (hereinafter referred to as “S3”) is additionally displayed (FIG. 3C). When the object 7 enters the noticeable photographed image (FIG. 3D), the display of the own vehicle image CI and the index S is appropriately stopped (FIG. 3E).

  Here, lines (broken lines) such as contour lines are also attached in the display screens of FIGS. This is an equidistant line indicating a position equidistant from the vehicle 1. By displaying such equidistant lines in the display screen, it is possible to easily recognize the distance from the vehicle 1 to the object 7 when the object 7 enters the noticed captured image.

  Next, a series of processes in which the obstacle alarm device 100 displays the composite image in which the vehicle image image CI and the index S are superimposed and displayed on the target captured image will be described with reference to the schematic diagram of FIG. First, the captured image acquisition unit 11 acquires a captured image G captured by the camera 5 of the vehicle 1 (step # 1).

  Next, the noticeable captured image generation unit 12 generates the central portion (narrow field of view N) of the acquired photographed image G as the noticeable photographed image (step # 2). On the other hand, the outer area generation unit 13 generates both lateral portions of the acquired captured image G as the outer area O (step # 3). Whether or not the object 7 is present in the outer region O generated in this way is determined by the object presence determination unit 14 (step # 4).

  If it is determined that the object 7 exists in the outer region O, the moving direction determination unit 15 determines the moving direction of the object 7 (step # 5). When the moving direction of the object 7 is from the outer region O toward the narrow visual field N corresponding to the target photographed image, an explicit image is output by the explicit image output unit 16 (step # 6). This explicit image is output with reference to the explicit image stored in the explicit image storage unit 17.

  The composite image generation unit 18 generates a composite image by superimposing the explicit image output in Step # 6 on the noticeable captured image generated in Step # 2 (Step # 7). The generated composite image is displayed on the monitor 50 (step # 8). Thus, the object 7 exists around the vehicle 1 for the occupant of the vehicle 1 by displaying the vehicle image image CI and the index S superimposed on the noticeable image according to the object 7 approaching the vehicle 1. And the direction of the object 7 approaching the vehicle 1 can be specified. Therefore, it is possible to grasp the situation around the vehicle 1 and to clearly indicate that an obstacle is approaching.

  As described above, according to the obstacle alarm device 100 according to the present invention, the object 7 approaching the vehicle 1 has entered the imaging range even if the object 7 is not shown in the screen of the monitor 50 provided in the vehicle 1. At the time, the presence and direction of the object 7 approaching the vehicle 1 can be clearly shown to the occupant while displaying the situation around the vehicle 1. For this reason, even when the screen size of the monitor 50 is small, the object 7 approaching the vehicle 1 is not missed. Therefore, the presence of the object 7 approaching the vehicle 1 can be clearly shown to the occupant without missing the object 7 around the vehicle 1.

[Other Embodiments]
In the above-described embodiment, the explicit image output unit 16 has been described as performing display in which the own vehicle image image CI is moved from the center toward the outer region O where the object 7 exists in accordance with the addition of the index S. However, the scope of application of the present invention is not limited to this. Even when the index S is added, it is naturally possible to configure the vehicle image image CI not to move to the outer region O side. Even in such a case, it is naturally possible to clearly indicate to the occupant the presence of the object 7 approaching the vehicle 1 in accordance with the display of the index S and the increase in the index S.

  In the embodiment described above, an example in which the object 7 approaching the vehicle 1 is approaching from one side in the left-right direction has been described. The obstacle alarm device 100 according to the present invention can also be applied when the object 7 is approaching from both the left and right sides. In such a case, the explicit image output unit 16 is preferably configured to enlarge the vehicle image image CI and display it at the center when the object 7 approaches the target captured image from both the left and right sides.

  An example of such a configuration is shown in FIG. For example, as shown in FIG. 5A, when it is detected that the object 7 in the right outer region O has moved to the center side of the narrow field region N, the vehicle The image image CI is displayed in a superimposed manner, and an index S (hereinafter referred to as “S1”) is superimposed and displayed on the outer region O side where the object 7 is present in the target photographed image (FIG. 5A). ).

  As shown in FIG. 5B, when the object 7 further moves to the center side of the target photographed image, the own vehicle image image CI is moved to the outer region O where the object 7 exists, and is displayed first. A larger index S (hereinafter referred to as “S2”) than the previously performed index S1 is additionally displayed (FIG. 5B).

  In such a state, when the object 7 in the right outer region O moves to the center side of the target captured image, the object 7 that moves to the center side of the target captured image is also detected in the left outer region O. The vehicle image CI is enlarged and displayed at the center of the noticeable photographed image. Also, an index S indicating the approach of the object 7 in the left outer region O and an index S (S4) indicating the approach of the object 7 in the right outer region O are displayed (FIG. 5C). By displaying in such a form, even when the object 7 approaches from both the left and right sides of the vehicle 1, it is possible to clearly indicate the approach of the object 7 to the passenger of the vehicle 1.

  In the embodiment described above, the equidistant line indicating the equidistant position from the vehicle 1 is displayed on the display screen. However, the scope of application of the present invention is not limited to this. Of course, it is possible to adopt a configuration in which no equidistant lines are displayed in the display screen.

  In the above-described embodiment, the explicit image output unit 16 has been described as stopping the display of the index S and the vehicle image CI when the object 7 enters the noticeable captured image. However, the scope of application of the present invention is not limited to this. For example, the display of the index S and the vehicle image CI can be stopped when the object 7 reaches the center of the noticeable photographed image, and the index S when the object 7 leaves the noticeable photographed image. It is also possible to adopt a configuration in which the display of the own vehicle image image CI is stopped.

  In the above-described embodiment, the explicit image output unit 16 specifies a plurality of movements of the object O from the outer region O where the object 7 exists in the target captured image toward the center toward the center of the target captured image. Are sequentially displayed at different positions, and the index S to be displayed later and the index S displayed immediately before are displayed larger than the index S displayed immediately before. explained. However, the scope of application of the present invention is not limited to this. The explicit image output unit 16 can naturally be configured not to display the index S, that is, to display only the own vehicle image CI.

  The present invention relates to an obstacle alarm device that clearly indicates to an occupant the presence of an obstacle approaching a vehicle.

DESCRIPTION OF SYMBOLS 1: Vehicle 7: Object 11: Photographed image acquisition part 12: Attention photographed image generation part 14: Object presence determination part 15: Movement direction determination part 16: Explicit image output part 19: Own vehicle image image generation part 100: Obstacle warning Device CI: Vehicle image G: Photographed image O: Outside area S (S1-S3): Index

Claims (6)

A captured image acquisition unit that acquires a captured image of a scene behind the vehicle;
An attention-captured image generation unit that generates an attention-captured image based on the captured image;
A vehicle image image generation unit that generates a translucent vehicle image when the vehicle is viewed from behind,
An object presence determination unit that determines whether or not an object exists in an outer region outside the target captured image;
A moving direction determination unit that determines the moving direction of the object in the outer region;
An explicit image output unit that performs display to display the vehicle image at the center of the target captured image when the movement direction determination unit determines that the object in the outer region moves to the center of the target captured image When,
Equipped with a,
The explicit image output unit is an obstacle alarm device that performs a display for moving the vehicle image from the center to the outer region side where the object exists in accordance with the movement of the object . A captured image acquisition unit that acquires a captured image of a scene behind the vehicle;
An attention-captured image generation unit that generates an attention-captured image based on the captured image;
A vehicle image image generation unit that generates a translucent vehicle image when the vehicle is viewed from behind,
An object presence determination unit that determines whether or not an object exists in an outer region outside the target captured image;
A moving direction determination unit that determines the moving direction of the object in the outer region;
An explicit image output unit that performs display to display the vehicle image at the center of the target captured image when the movement direction determination unit determines that the object in the outer region moves to the center of the target captured image When,
With
The explicit image output unit, enlarged and harm thereof alarm device impaired displayed on the center of the vehicle images if the object approaches from the right and left sides with respect to the target captured images. A captured image acquisition unit that acquires a captured image of a scene behind the vehicle;
An attention-captured image generation unit that generates an attention-captured image based on the captured image;
A vehicle image image generation unit that generates a translucent vehicle image when the vehicle is viewed from behind,
An object presence determination unit that determines whether or not an object exists in an outer region outside the target captured image;
A moving direction determination unit that determines the moving direction of the object in the outer region;
An explicit image output unit that performs display to display the vehicle image at the center of the target captured image when the movement direction determination unit determines that the object in the outer region moves to the center of the target captured image When,
With
The explicit image output unit sequentially displays a plurality of indices that clearly indicate the movement of the object from the outer region side where the object is present to the center side of the target image. with displays in different positions, greatly displayed causes the display also performs obstacles alarm system than indicators displayed previously towards the indicators to be displayed later in detail and indicators displayed on the index before and to be displayed after. 2. The obstacle alarm device according to claim 1 , wherein the explicit image output unit enlarges and displays the vehicle image image at the center when the object approaches the target captured image from both right and left sides. The explicit image output unit sequentially displays a plurality of indices that clearly indicate the movement of the object from the outer region side where the object is present to the center side of the target image. 3. The obstacle according to claim 1, wherein the obstacle is displayed at a different position, and the indicator displayed later and the indicator displayed immediately before are also displayed so that the indicator displayed later is larger than the indicator displayed immediately before. Alarm device. The obstacle alarm device according to any one of claims 1 to 5 , wherein the explicit image output unit stops the display when the object enters the target captured image.

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