Iris control system

Abstract

To provide an iris control system capable of properly executing iris control of a lens of a camera used for trigger imaging.SOLUTION: The iris control system according to an embodiment of the present invention comprises: an FA camera 32 for performing trigger imaging in accordance with a trigger signal given from the outside; a moving image signal acquisition unit which acquires a moving image signal being a video signal at predetermined moving image frame intervals; and an iris control device 38 which generates an iris control signal based on the moving image signal acquired by the moving image signal acquisition unit and applies the iris control signal to a lens 33 of the FA camera.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an iris control system for controlling the iris of a lens of a camera that performs trigger imaging in accordance with a trigger signal. [Background technology]

[0002] Conventionally, inspection systems have been developed that use images captured by a camera mounted on the train while the train is traveling to inspect facilities along the tracks of the train (for example, Patent Document 1). Such inspection systems generally use trigger imaging cameras that perform trigger imaging in response to a trigger signal. In the following, the term "FA (Factory Automation) camera" is used to represent the trigger imaging camera, but it may also be called an "industrial camera" or a "machine vision camera."

[0003] Fig. 1 shows an overview of an inspection system using an FA camera. In the inspection system of Fig. 1, a wheel rotation signal generated from a wheel rotation signal generator 15 while a train 10 is running is input to a trigger signal generator 16, which generates a trigger signal based on the wheel rotation signal, and the FA camera 12 performs trigger imaging according to the trigger signal, and the obtained video signal is stored in a recording device 17. The imaging range 14 of the FA camera 12 is set so as to image, for example, another track 11 adjacent to the track on which the train 10 runs. Note that the FA camera 12 does not have a function for outputting an iris control signal, and therefore cannot control the iris of the lens 13 of the FA camera 12.

[0004] A typical FA camera has a function to capture images at intervals of an externally supplied trigger signal, so it is suitable for the need to capture images at fixed or arbitrary intervals. However, since iris control is not possible with an FA camera, it is difficult to capture images at an appropriate image level according to changes in sunlight when performing trigger imaging in an outdoor environment. As a result, for example, while good quality images (appropriate image level) can be obtained during the day, there is a concern that images of dark quality (low image level) may be obtained after the evening.

[0005] On the other hand, surveillance cameras used for surveillance purposes have the function of capturing video at a specified frame interval, and also have an iris control output to control the lens aperture according to changes in sunlight and lighting illuminance. Therefore, we will consider the case where an inspection system is built using a surveillance camera instead of an FA camera.

[0006] Fig. 2 shows an overview of an inspection system using a surveillance camera. In the inspection system of Fig. 2, a surveillance camera 18 captures video while a train 10 is running, and the video signal is stored in a recording device 17. The surveillance camera 18 has an imaging range 14 set so as to capture an image of another track 11 adjacent to the track on which the train 10 runs, for example. The surveillance camera 18 also generates an iris control signal 19 based on the video signal obtained by capturing the video, and provides the signal to an auto iris lens 20 of the surveillance camera 18, thereby enabling iris control in response to changes in sunlight and lighting illuminance.

[0007] For example, a surveillance camera generates an iris control signal (DC voltage signal) according to the luminance level of a video signal of a continuous predetermined frame period (e.g., 30 fps), supplies it to a lens, and adjusts the iris (aperture) of the lens according to the iris control signal. That is, a feedback loop is formed so that the video level is constant by controlling the iris to be narrowed when the video level is high and the iris to be open when the video level is low. With this type of iris control, it is possible to obtain video with an appropriate video level when capturing video in an outdoor environment.

[0008] However, surveillance cameras do not have the function of capturing images at intervals of externally supplied trigger signals, and are therefore not suitable for capturing images at fixed or arbitrary intervals. For this reason, when capturing images of a given section of a track, it is difficult to obtain a track image with good divisions, resulting in partially overlapping track images or discontinuous track images. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Special Publication No. 7-35969 Summary of the Invention [Problem to be solved by the invention]

[0010] As mentioned above, FA cameras were commercialized on the assumption that they would be used indoors in a well-lit environment, so they did not have a mechanism for controlling the lens iris. Also, in the case of a trigger imaging function that receives an external trigger signal and captures an image at that timing, which is one of the features of FA cameras, the video signal is not continuous like a video, so it could not be used as is to generate an iris control signal.

[0011] The present invention has been made in consideration of the above-described conventional circumstances, and has an object to provide an iris control system capable of appropriately performing iris control of the lens of a camera used for trigger imaging. [Means for solving the problem]

[0012] In order to achieve the above object, an iris control system according to one aspect of the present invention is configured as follows: That is, the iris control system according to the present invention is characterized by including a trigger imaging camera that performs trigger imaging in response to an externally applied trigger signal, a moving image signal acquisition unit that acquires a moving image signal that is a video signal at a predetermined moving image frame interval, and an iris control device that generates an iris control signal based on the moving image signal acquired by the moving image signal acquisition unit and applies the iris control signal to a lens of the trigger imaging camera.

[0013] As an example, the iris control system may be configured to realize the video signal acquisition unit by using a memory that temporarily stores the video signal output from the trigger imaging camera and converting the video signal from the trigger imaging camera into a video signal at the video frame interval, and the iris control device may be configured to generate the iris control signal based on the video signal converted by the video signal acquisition unit from the video signal from the trigger imaging camera and apply the iris control signal to the lens of the trigger imaging camera.

[0014] As another example of the iris control system, the trigger imaging camera can be switchable between a trigger imaging mode in which trigger imaging is performed in accordance with the trigger signal and a video imaging mode in which video imaging is performed at the video frame interval, the video signal acquisition unit is realized by operating the trigger imaging camera in the video imaging mode, and the iris control device can be configured to apply the iris control signal, which is generated based on the video signal immediately before the trigger imaging camera is switched from the video imaging mode to the trigger imaging mode, to a lens of the trigger imaging camera in the trigger imaging mode.

[0015] As yet another example, the iris control system may further include a video imaging camera that captures video at the video frame interval, the video imaging camera realizing the video signal acquisition unit, and the iris control device may be configured to apply the iris control signal generated based on the video signal obtained by the video imaging camera to the lens of the trigger imaging camera.

[0016] Here, the first camera and the second camera may be mounted on the same moving object. Also, the video imaging camera may be arranged on the moving object further forward than the trigger imaging camera, the trigger imaging camera performs trigger imaging while the moving object is traveling through a predetermined imaging target section, and the iris control device may be configured to continue applying the iris control signal generated just before the video imaging camera leaves the imaging target section to the trigger imaging camera until the trigger imaging camera leaves the imaging target section. Effect of the Invention

[0017] According to the present invention, it is possible to provide an iris control system capable of appropriately controlling the iris of the lens of a camera used for trigger imaging. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram showing an overview of an inspection system using an FA camera. [Diagram 2] FIG. 1 is a diagram showing an overview of an inspection system using a surveillance camera. [Diagram 3] 1 is a diagram showing an overview of an inspection system including an iris control system according to a first embodiment of the present invention. [Figure 4] FIG. 13 is a diagram showing an example of the configuration of an iris control signal device according to [Method A]. [Diagram 5] FIG. 13 is a diagram showing an example of a timing chart relating to [Method A]. [Figure 6] FIG. 13 is a diagram showing an example of the configuration of an iris control signal device according to [Method B]. [Figure 7] FIG. 13 is a diagram showing an example of a timing chart relating to [Method B]. [Figure 8] FIG. 11 is a diagram showing an example of a timing chart of an iris control system according to a second embodiment of the present invention. [Figure 9] FIG. 11 is a diagram showing an example of a timing chart of an iris control system according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] 3, an iris control system according to an embodiment of the present invention includes an FA camera 32 that performs trigger imaging in response to an externally applied trigger signal, a moving image signal acquisition unit that acquires a moving image signal that is a video signal at a predetermined moving image frame interval, and an iris control device 38 that generates an iris control signal based on the moving image signal acquired by the moving image signal acquisition unit and applies the iris control signal to lens 33 of the FA camera. The iris control system according to this proposal will be specifically described below with reference to the drawings.

[0020] Fig. 3 shows an overview of an inspection system including an iris control system according to a first embodiment of the present invention. In the inspection system of Fig. 3, a wheel rotation signal generated from a wheel rotation signal generator 35 while a train 30 is running is input to a trigger signal generator 36, which generates a trigger signal based on the wheel rotation signal, and the FA camera 32 performs trigger imaging in accordance with the trigger signal, and the obtained video signal is stored in a recording device 37. The imaging range 34 of the FA camera 32 is set so as to image, for example, another track 31 adjacent to the track on which the train 30 runs.

[0021] The wheel rotation signal generated by the wheel rotation signal generator 35 is a pulse signal including distance information based on the wheel circumference. For example, when the wheel rotation signal generator 35 generates a pulse signal of 300 pulses / revolution, one pulse corresponds to a moving distance of 1 / 300 of the wheel circumference. In other words, a pulse signal is output for each moving distance of 1 / 300 of the wheel circumference. By generating a trigger signal each time this pulse signal is counted up to a predetermined count value, a system can be constructed in which a track image is captured each time the train 30 travels a moving distance equivalent to the wheel circumference / 300×predetermined count value. In addition, by setting the predetermined count value so that the imaging field of the FA camera 32 at this time matches the moving distance, a track image with good divisions (i.e., a track image without overlaps or jumps) can be obtained.

[0022] The video signal output from the FA camera 32 is supplied not only to the recording device 37 but also to an iris control device 38. The iris control device 38 generates an iris control signal 39 based on the video signal from the FA camera 32 and supplies it to the auto iris lens 33 of the FA camera 32, thereby performing trigger imaging under iris control according to changes in sunlight and lighting illuminance. In the following, an example will be described in which the iris control device 38 is provided separately from the FA camera 32, but the FA camera 32 may also be configured to have the iris control device 38 built in. In this example, iris control suitable for feedback loop operation is achieved by two methods, [Method A] and [Method B]. Each method will be specifically described below.

[0023] Regarding [Method A] In [Method A], a memory that temporarily stores the video signal output from the FA camera is used to convert the video signal from the FA camera into a video signal that is a video signal at video frame intervals, and an iris control signal is generated based on the converted video signal and applied to the lens of the FA camera. Details of [Method A] will be described below with reference to Figures 4 and 5.

[0024] FIG. 4 shows a configuration example of an iris control device 38(A) according to [Method A]. The iris control device 38(A) in FIG. 4 has a video level holding unit 41 and an iris control signal generating unit 42. The video level holding unit 41 is configured using a memory capable of temporarily storing a video signal output from the FA camera 32. The video level holding unit 41 holds a video signal input at each trigger signal interval until the next video signal is input, and repeatedly outputs the video signal at each video frame interval shorter than the trigger signal interval. This alternatively realizes a video signal acquiring unit that acquires a video signal that is a video signal at a video frame interval. The iris control signal generating unit 42 generates an iris control signal based on the video signal output from the video level holding unit 41 (video signal acquiring unit). The iris control device 38(A) controls the iris by providing the iris control signal generated as described above to the lens of the FA camera 32.

[0025] FIG. 5 shows an example of a timing chart relating to [Method A]. As shown in FIG. 5, in an inspection system that captures an image of a target track from a train to obtain a track image, an imaging trigger signal based on a distance signal obtained from a wheel rotation signal generator or another distance measuring device is provided to the FA camera 32. The FA camera 32 performs trigger imaging in accordance with the trigger signal to obtain a video signal of a track image obtained by capturing an image of the track at a fixed distance (at each trigger signal interval). When the frame interval (i.e., the trigger signal interval) of the captured video signal output from the FA camera 32 is greater than the frame interval of a moving image (e.g., 30 fps), the iris control device 38 (A) converts the captured video signal into an iris control video signal corresponding to the moving image by repeatedly outputting the captured video signal at each moving image frame interval using the video level holding unit 41. Based on this iris control video signal, an iris control signal generating unit 42 generates an iris control signal and provides it to the lens of the FA camera 32.

[0026] As described above, in [Method A], a video signal acquisition unit is realized by converting the video signal from the FA camera 32 into a video signal with a predetermined video frame interval, using a memory (video level holding unit 41) that temporarily stores the video signal at the trigger signal interval output from the FA camera 32. The iris control device 38(A) generates an iris control signal based on the video signal converted from the video signal from the FA camera 32, and applies this iris control signal to the lens of the FA camera 32. This makes it possible to adaptively control the iris of the lens of the FA camera 32 that performs trigger imaging in response to changes in sunlight and lighting illuminance.

[0027] Here, the above explanation is for the case where the frame interval of the trigger image is larger than the frame interval of the moving image (e.g., 30 fps), but the frame interval of the trigger image may be smaller than the frame interval of the moving image. In this case, instead of repeatedly outputting the video signal of the trigger image and converting it into the moving image signal for iris control, the video signal of the trigger image may be converted into the moving image signal for iris control by thinning it out.

[0028] Regarding [Method B] [Method B] uses an FA camera that can switch between a trigger imaging mode in which trigger imaging is performed according to a trigger signal and a video imaging mode in which video imaging is performed at video frame intervals, and an iris control signal generated based on a video signal immediately before switching from the video imaging mode to the trigger imaging mode is applied to the lens of the FA camera in the trigger imaging mode. In the following description, it is assumed that the FA camera is controlled by an imaging mode switching signal output from a control device (not shown) so as to perform trigger imaging in a predetermined imaging target section and video imaging in other sections. Details of [Method B] will be described below with reference to Figs. 6 and 7.

[0029] Fig. 6 shows an example of the configuration of an iris control device 38(B) relating to [Method B]. The iris control device 38(B) in Fig. 4 has an iris control signal generation unit 51 and an iris control signal holding unit 52. The iris control signal generation unit 51 generates an iris control signal based on a video signal output from an FA camera 32' capable of switching between imaging modes. The iris control signal holding unit 52 is a memory capable of temporarily storing the iris control signal generated by the iris control signal generation unit 51. While the FA camera 32' is in a video imaging mode, the iris control device 38(B) outputs the iris control signal generated by the iris control signal generation unit 51 and applies it to the lens of the FA camera 32' to control the iris. In addition, when the FA camera 32' switches to the trigger imaging mode, the iris control device 38(B) stores the iris control signal immediately before that in the iris control signal holding unit 52, and during the trigger imaging mode (until returning to the video imaging mode), outputs the iris control signal stored in the iris control signal holding unit 52 and applies it to the lens of the FA camera 32' to control the iris.

[0030] FIG. 7 shows an example of a timing chart relating to [Method B]. As shown in FIG. 7, in an inspection system that captures an image of a target track from a train to obtain a track image, an imaging mode switching signal and an imaging trigger signal based on a distance signal obtained from a wheel rotation signal generator or another distance measuring device are provided to an FA camera 32'. The imaging mode switching signal is also distributed and supplied to an iris control device 38(B). Note that the generation of the imaging mode switching signal is not limited to a method of automatically generating the signal based on a distance signal, and may be, for example, a method of generating the signal based on a signal from another sensor device that detects that the train has reached the target imaging section, or a method of generating the signal in response to manual operation by an operator or the like.

[0031] Before the train arrives at the imaging target section, the FA camera 32' is in a video imaging mode. In this case, the iris control device 38(B) generates an iris control signal based on the acquired video signal of the moving image (e.g., 30 fps) output from the FA camera 32', and supplies it to the lens of the FA camera 32' to dynamically control the iris. Thereafter, when the train arrives at the imaging target section and the FA camera 32' switches to the trigger imaging mode, the iris control device 38(B) stores the iris control signal immediately before that. Then, while the train is running in the imaging target section (during the trigger imaging mode), the iris control device 38(B) supplies the stored iris control signal to the lens of the FA camera 32' to control the iris. In other words, during the trigger imaging mode, the iris is fixed to the immediately previous iris. After that, when the train passes the imaging target section, the FA camera 32' returns to the video imaging mode. Accordingly, the iris control device 38(B) generates an iris control signal based on the captured video signal of the moving image output from the FA camera 32', and applies it to the lens of the FA camera 32' to resume dynamic iris.

[0032] As shown in FIG. 7, the acquired video signal when the imaging mode of the FA camera 32' is switched and imaging is performed includes a mixture of moving images (video signals for video imaging) and trigger images (video signals for trigger imaging). If the frame interval of the trigger images is greater than the frame interval of the video images (e.g., 30 fps), the images are not suitable for iris control. Therefore, during the imaging of the trigger images in the trigger imaging mode, an iris control signal immediately before the start of trigger imaging is stored in memory so that the iris is fixed to the final iris at the time of the immediately preceding video imaging. This allows the iris of the lens of the FA camera 32' to be controlled based on the video signals of the moving images, as in the case of a surveillance camera, and the iris of the lens of the FA camera 32' to be fixed to the state immediately before during the period in which trigger imaging is performed in the imaging target section. Therefore, it is possible to adaptively control the iris of the lens of the FA camera 32' when performing trigger imaging in response to changes in sunlight and lighting illuminance.

[0033] As described above, in [Method B], an FA camera 32' is used that can switch between a trigger imaging mode in which trigger imaging is performed according to a trigger signal and a video imaging mode in which video imaging is performed at a predetermined video frame interval. That is, a video signal acquisition unit is realized by operating the FA camera 32' in the video imaging mode. The iris control device 38(B) applies an iris control signal generated based on a video signal immediately before the FA camera 32' switches from the video imaging mode to the trigger imaging mode to the lens of the FA camera 32' in the trigger imaging mode. This makes it possible to adaptively control the iris of the lens of the FA camera 32' that performs trigger imaging in response to changes in sunlight and lighting illuminance.

[0034] 8 shows an example of a timing chart of an iris control system according to a second embodiment of the present invention. In the above-mentioned first embodiment, one camera is used to capture the image of the target imaging section, but in the second embodiment, two cameras are used to capture the image of the target imaging section. In this example, a surveillance camera 61 that captures video at a predetermined video frame interval and an FA camera 62 that captures triggered images in response to a trigger signal are used. In the following, an example will be described in which the surveillance camera 61 has an internal iris control device 38, but the iris control device 38 may be provided separately from the surveillance camera 61 and the FA camera 62.

[0035] The surveillance camera 61 and the FA camera 62 are arranged close to each other on the same train. In other words, the surveillance camera 61 and the FA camera 62 are arranged so as to capture images with substantially the same angle of view. The surveillance camera 61 generates a video signal, which is a video signal of a moving image (e.g., 30 fps), and generates an iris control signal based on the video signal and supplies it to its own lens, thereby adaptively controlling the iris of the lens of the surveillance camera 61 in response to changes in sunlight and lighting illuminance. In addition, the iris control signal generated by the surveillance camera 61 is also distributed and supplied to the lens of the FA camera 62. As a result, in conjunction with the iris control of the lens of the surveillance camera 61, the iris control of the lens of the FA camera 62 is similarly performed.

[0036] As described above, in the second embodiment, a surveillance camera 61 that captures video at a predetermined video frame interval and an FA camera 62 that captures triggered video in response to a trigger signal are used. That is, a video signal acquisition unit is realized by the surveillance camera 61. The iris control device 38 applies an iris control signal generated based on the video signal obtained by the surveillance camera 61 to the lens of the FA camera 62. This makes it possible to adaptively control the iris of the lens of the FA camera 62 that captures triggered video in response to changes in sunlight and lighting illuminance.

[0037] FIG. 9 shows an example of a timing chart of an iris control system according to a third embodiment of the present invention. In the third embodiment, an iris control method suitable for a case where an imaging target section includes a section where the iris control signal changes significantly, such as a tunnel, is described. In the above-mentioned second embodiment, two cameras are arranged close to each other on the same train, but in the third embodiment, two cameras are arranged at positions apart on the same train. In this example, a monitoring camera 71 that captures video at a predetermined video frame interval and an FA camera 72 that captures triggered video in response to a trigger signal are used. In the following, a configuration in which the monitoring camera 71 has an iris control device 38 built in will be described as an example, but a configuration in which the iris control device 38 is provided separately from the monitoring camera 71 and the FA camera 72 may also be used.

[0038] When the imaging target section includes a section where the iris control signal changes significantly, such as a tunnel, the surveillance camera 71 is placed at a position ahead of the train (a position preceding the FA camera 72 in the direction of travel) as shown in FIG. 9. This allows the surveillance camera 71 to enter the tunnel first, and the FA camera 72 to enter the tunnel later. The surveillance camera 71 generates an iris control signal that narrows the iris in bright outdoor areas, but when entering a dark tunnel, it generates an iris control signal that opens the iris and supplies it to its own lens to control the iris. The iris control signal generated by the surveillance camera 71 is also distributed and supplied to the lens of the FA camera 72. This allows the iris control of the lens of the FA camera 72 to be similarly performed in conjunction with the iris control of the lens of the surveillance camera 71.

[0039] The lens of the FA camera 72 receives an iris control signal from the surveillance camera 71 to open the iris before the FA camera 72 enters the tunnel. Therefore, the lens of the FA camera 72 is subjected to iris control suitable for capturing images of the dark parts of the tunnel when the FA camera 72 enters the tunnel, so clear images can be captured with an appropriate iris from the tunnel entrance. However, a problem here is iris control at the tunnel exit. Because the surveillance camera 71 exits the tunnel before the FA camera 72, the FA camera 72, which receives the iris control signal from the surveillance camera 71 and performs iris control, receives an iris control signal to narrow the iris before the FA camera 72 exits the tunnel. For this reason, if left as is, there is a problem that the iris of the lens will be narrowed before the FA camera 72 exits the tunnel.

[0040] In order to avoid such a problem, the iris control signal generated immediately before the monitoring camera 71 exits the tunnel may be continuously applied to the FA camera 72 until the FA camera 72 exits the tunnel. More specifically, when the conditions that the monitoring camera 71 is outside the tunnel and the FA camera 72 is inside the tunnel are satisfied, a process may be performed to fix the iris control signal of the FA camera 72 to the iris control signal immediately before the monitoring camera 71 exits the tunnel. Whether or not the monitoring camera 71 or the FA camera 72 is in the imaging target section may be determined by receiving position information from a mileage management system used for normal train operation, for example, or may be determined based on signals from vehicle detection devices installed before and after the imaging target section.

[0041] As described above, in the third embodiment, the monitoring camera 71 that captures video at a predetermined video frame interval and the FA camera 72 that captures triggered video in response to a trigger signal are used. That is, the monitoring camera 71 realizes a video signal acquisition unit. The monitoring camera 71 is placed on the front side of the train relative to the FA camera 72. The iris control device 38 applies an iris control signal generated based on the video signal obtained by the monitoring camera 71 to the lens of the FA camera 72. The iris control device 38 further applies an iris control signal generated immediately before the monitoring camera 71 leaves a target imaging section (for example, a tunnel) to the FA camera 72 until the FA camera 72 leaves the target imaging section. This makes it possible to adaptively control the iris of the lens of the FA camera 72 that captures triggered video in response to changes in sunlight and lighting illuminance.

[0042] In the examples of Figures 5 and 7 to 9, the track images are arranged in a continuous line for ease of understanding, but these are merely examples. Also, instead of using the video signal of the track image itself to generate the iris control signal, it is possible to generate the iris control signal by other methods, such as by converting the video signal into a luminance information signal and using the converted signal to generate the iris control signal.

[0043] In addition, the above explanation relates to the case where the present invention is applied to a system that captures and inspects ground tracks from a moving train, but this is merely an example. For example, an FA camera that performs trigger imaging is also useful in other systems, such as a system in which a camera is installed on the ground to capture and inspect the exterior of a running vehicle, and the present invention can be applied to those systems as well.

[0044] The present invention can also be applied to the smart maintenance field, and the maintenance and inspection field of long-distance structures and long objects. For example, by applying the present invention to the smart maintenance field in which aging changes are image-managed for the maintenance and inspection of outdoor buildings, bridges, roads, railroad tracks, train cars, and the like, an image system can be constructed that images objects at regular intervals and manages the images with high efficiency. In recent years, the need for CBM (Condition Based Maintenance) rather than TBM (Time Based Maintenance) has increased for the deterioration of public buildings. In particular, an image capturing system for capturing the condition of objects required for CBM is an essential means for inspecting the presence or absence of deterioration, and the present invention makes it possible to realize highly efficient imaging.

[0045] Although the embodiments of the present invention have been described above, these embodiments are merely illustrative and do not limit the technical scope of the present invention. The present invention can take various other embodiments, and various modifications such as omissions and substitutions can be made without departing from the gist of the present invention. These embodiments and modifications are included in the scope and gist of the invention described in this specification, etc., and are included in the scope of the invention described in the claims and their equivalents.

[0046] Furthermore, the present invention can be provided not only as devices such as those described above or as a system composed of these devices, but also as methods executed by these devices, programs for causing a processor to realize the functions of these devices, and storage media for storing such programs in a computer-readable format. [Industrial Applicability]

[0047] The present invention can be used in an iris control system that controls the iris of a lens of a camera that performs trigger imaging in accordance with a trigger signal. [Explanation of symbols]

[0048] 10: train, 11: track, 12: FA camera, 13: lens, 14: imaging range, 15: wheel rotation signal generator, 16: trigger signal generator, 17: recording device, 18: surveillance camera, 19: iris control signal, 20: lens, 30: train, 31: track, 32: FA camera, 33: lens, 34: imaging range, 35: wheel rotation signal generator, 36: trigger signal generator, 37: recording device, 38: iris control device, 39: iris control signal, 41: video level holding unit, 42: iris control signal generating unit, 51: iris control signal generating unit, 52: iris control signal holding unit, 61: surveillance camera, 62: FA camera, 71: surveillance camera, 72: FA camera

Claims

1. a trigger imaging camera that performs trigger imaging in response to an externally applied trigger signal; a moving image signal acquisition unit that acquires a moving image signal that is a video signal at a predetermined moving image frame interval; an iris control device that generates an iris control signal based on the moving image signal obtained by the moving image signal acquisition unit and applies the iris control signal to a lens of the trigger imaging camera.

2. 2. The iris control system of claim 1, a memory for temporarily storing a video signal output from the trigger imaging camera is used to convert the video signal from the trigger imaging camera into a video signal having the video frame interval, thereby implementing the video signal acquisition unit; The iris control device generates the iris control signal based on a video signal converted by the video signal acquisition unit from the video signal from the trigger imaging camera, and applies the iris control signal to a lens of the trigger imaging camera, characterized in that the iris control device generates the iris control signal based on a video signal converted by the video signal acquisition unit from the video signal from the trigger imaging camera, and applies the iris control signal to a lens of the trigger imaging camera.

3. 2. The iris control system of claim 1, the trigger imaging camera is switchable between a trigger imaging mode in which trigger imaging is performed in response to the trigger signal and a video imaging mode in which video imaging is performed at the video frame intervals; The video signal acquisition unit is realized by operating the trigger imaging camera in a video imaging mode; The iris control system is characterized in that the iris control device applies the iris control signal, which is generated based on a video signal immediately before the trigger imaging camera is switched from a video imaging mode to a trigger imaging mode, to a lens of the trigger imaging camera in the trigger imaging mode.

4. 2. The iris control system of claim 1, The video capture camera further includes a video capture device that captures video at the video frame intervals, The video signal acquisition unit is realized by the video imaging camera; An iris control system, characterized in that the iris control device applies the iris control signal, generated based on a video signal obtained by the video imaging camera, to a lens of the trigger imaging camera.

5. 5. The iris control system according to claim 4, 13. An iris control system, wherein the trigger imaging camera and the video imaging camera are mounted on the same moving object.

6. 6. The iris control system according to claim 5, the video imaging camera is disposed forward of the moving object relative to the trigger imaging camera, The trigger imaging camera performs trigger imaging while the moving object is traveling through a predetermined imaging target section, The iris control system is characterized in that the iris control device continues to apply the iris control signal generated immediately before the video imaging camera leaves the imaging target section to the trigger imaging camera until the trigger imaging camera leaves the imaging target section.

Images