Video transmission delay time measurement system and video transmission delay time measurement method

Abstract

To allow the delay time of video transmission to be measured while an actual video is taken.SOLUTION: A video transmission delay time measurement system includes a transmitting unit and a receiving unit. The transmitting unit includes a transmitting-side reference signal transmitting section that transmits a transmitting-side reference signal, a blinking marker that blinks a marker light based on the transmitting-side reference signal, a photographing device that takes video including a subject to be photographed and the blinking marker, and a data transmitting section that transmits data of the video. The receiving unit includes a data receiving section that receives the data of the video, a display device that displays the video, a first blinking detection section that detects the blinking of the marker light in the video, a receiving-side reference signal transmitting section that transmits a receiving-side reference signal, and a delay time information output section that outputs information about a video transmission delay time based on a blinking signal indicating the blinking state of the marker light and the receiving-side reference signal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a video transmission delay time measuring system and a video transmission delay time measuring method. [Background technology]

[0002] When a captured video is displayed on a display device installed in a remote location away from the shooting location, a time delay occurs between the time the video is captured and the time it is displayed. This time delay occurs because of the time required for encoding the captured video data, transmitting the encoded video data, transmitting the video data over a network, receiving the video data on the display device, decoding the received video data, and displaying the video based on the decoded video data.

[0003] In response to this, Patent Document 1 discloses a video transmission time measurement system that includes a blinking marker placed at the imaging location, an imaging location time timer placed at the imaging location, a light-receiving sensor that detects the blinking of the blinking marker projected and displayed by a video projection device placed at the projection location, a projection location time timer that is synchronized with the imaging location time timer, and a measurement camera that is also placed at the projection location and captures the image projected and displayed by the video projection device and the projection location time timer side by side. In this video transmission time measurement system, the imaging location time timer and the blinking marker are captured together by the imaging video camera, and the captured image is projected and displayed by the video projection device. Furthermore, the measurement camera simultaneously captures the projected and displayed image of the imaging location time timer and the projected location time timer, the time display of which is fixed according to the output from the light-receiving sensor, and the video transmission time is determined by reading the times of both timers from the captured image. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-171334 Summary of the Invention [Problem to be solved by the invention]

[0005] There are known technologies for remotely controlling objects, such as ships, vehicles, and various types of equipment, from a remote location. When performing such remote control, an operator may capture an image of the area in front of the object in the direction of movement, allowing the operator to visually view the captured image while remotely controlling the object. In such cases, a time delay between capturing and displaying the image can cause problems, and therefore it is desirable to measure the delay time in video transmission more accurately.

[0006] However, the delay time between capturing and displaying a video can vary depending on various circumstances. For example, some codec technologies for encoding video data compress and transmit the difference between a video and the immediately preceding video. When using such codec technologies, if there is little movement in the captured video, the difference between the video and the previous video will be small, whereas if there is a lot of movement in the video, the difference between the video and the immediately preceding video will be large. The larger the difference between the videos, the longer the time required for encoding, transmitting, and other processes of the video data. Furthermore, the time required for the transmission processing of video data also varies depending on, for example, the communication conditions of various networks that transmit the video data.

[0007] For this reason, it is desirable to measure the delay time of video transmission more accurately while actually capturing video, transmitting the video data to a remote location, and displaying the video data at the remote location. In contrast, the configuration disclosed in Patent Document 1 is not designed to measure the delay time of video transmission, which can fluctuate from moment to moment, while actually capturing video.

[0008] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a video transmission delay time measurement system and a video transmission delay time measurement method that can measure the delay time from when a video is captured until when it is displayed while actually capturing the video. [Means for solving the problem]

[0009] In order to solve the above problem, a video transmission delay time measuring system according to the present disclosure includes a transmission unit arranged at a shooting location and a reception unit installed at a remote location away from the shooting location, the transmission unit including a transmission-side GPS signal reception unit that receives a GPS (Global Positioning System) signal at the shooting location, a transmission-side reference signal transmission unit that transmits a transmission-side reference signal synchronized with the GPS signal received by the transmission-side GPS signal reception unit, a blinking marker that periodically blinks a marker light based on the transmission-side reference signal, a shooting device that shoots video including a subject and the blinking marker at the shooting location, and a data transmission unit that transmits data of the video shot by the shooting device, and the receiving unit includes a data reception unit that receives the video data and a display device that displays video based on the received video data. The display device includes a first blinking detection unit that detects blinking of the marker light in the image displayed on the display device, a receiving-side GPS signal receiving unit that receives a GPS signal at the remote location, a receiving-side reference signal transmitting unit that transmits a receiving-side reference signal synchronized with the GPS signal received by the receiving-side GPS signal receiving unit, and a delay time information output unit that outputs information regarding the image transmission delay time from when the image is captured by the imaging device to when the image is displayed on the display device, based on the blinking signal indicating the blinking state of the marker light detected by the first blinking detection unit and the receiving-side reference signal.

[0010] a step of receiving a GPS signal at the remote location; a step of transmitting a receiving-side reference signal synchronized with the GPS signal received at the remote location; a step of periodically flashing a marker light based on the transmitting-side reference signal; a step of capturing a video including a subject to be captured and the flashing marker at the capturing location; a step of transmitting data of the captured video; a step of receiving the video data at a remote location away from the capturing location; a step of displaying a video based on the received video data; a step of detecting flashing of the marker light in the displayed video; a step of receiving a GPS signal at the remote location; [Effects of the Invention]

[0011] According to the video transmission delay time measuring system and video transmission delay time measuring method of the present disclosure, it is possible to measure the video transmission delay time while actually capturing video. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating a configuration of a video transmission delay time measuring system according to a first embodiment of the present disclosure. [Figure 2] 3 is a diagram showing an example of a signal used in the video transmission delay time measurement system. FIG. [Figure 3] 1 is a flowchart showing the procedure of a video transmission delay time measuring method according to a first embodiment of the present disclosure. [Figure 4] FIG. 10 is a diagram illustrating a configuration of a video transmission delay time measuring system according to a second embodiment of the present disclosure. [Figure 5] 3 is a diagram showing an example of a signal used in the video transmission delay time measurement system. FIG. [Figure 6]10 is a diagram showing an example of a signal with an adjusted period used in the video transmission delay time measurement system. FIG. [Figure 7] FIG. 10 is a diagram illustrating a configuration of a video transmission delay time measuring system according to a third embodiment of the present disclosure. [Figure 8] FIG. 10 is a diagram illustrating a configuration of a video transmission delay time measuring system according to a fourth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments for implementing a video transmission delay time measuring system and a video transmission delay time measuring method according to the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to these embodiments. First Embodiment (Configuration of video transmission delay time measurement system) As shown in FIG. 1, the video transmission delay time measuring system 1A includes a transmitting unit 2 placed at a shooting location, and a receiving unit 5 installed at a remote location away from the shooting location.

[0014] The transmission unit 2 is disposed at a photographing location where it is possible to photograph the photographing target T. The transmission unit 2 is provided, for example, at an operation target that is remotely controlled by a remote control device (not shown). Examples of the operation target include various moving bodies such as ships, vehicles, etc. In the case of these moving bodies, the transmission unit 2 is mounted on the moving body, and the imaging device 3 of the transmission unit 2 captures an image of the area ahead in the traveling direction of the moving body as the imaging target T. Examples of the operation target include various devices and apparatuses. In this case, the imaging device 3 of the transmission unit 2 captures an image of, for example, a part of the device or apparatus that is to be remotely operated as the imaging target T. The transmission unit 2 may be attached to the device or apparatus, or may be provided on the floor, wall, ceiling, etc. around the device or apparatus.

[0015] The transmitting unit 2 includes a photographing device 3, a blinking marker 4, and a transmitting controller 20. The photographing device 3 photographs an image including the photographing target T and the blinking marker 4 at the photographing location.

[0016] The blinking marker 4 is arranged within the range 3a that can be photographed by the photographing device 3. An example of the blinking marker 4 is an LED (Light Emitting Diode). The blinking marker 4 is fixed to the photographing device 3, for example, via a fixing member 31. As a result, if vibration or the like occurs in the photographing target T, the blinking marker 4 and the photographing device 3 vibrate together, thereby preventing the blinking marker 4 from displacing relative to the photographing device 3 within the range 3a that can be photographed by the photographing device 3. The blinking marker 4 periodically blinks a marker light 4m at a predetermined blinking cycle under the control of the transmitting controller 20. The photographing device 3 photographs the blinking state of the marker light 4m of the blinking marker 4.

[0017] The transmitting controller 20 can be configured using a computer such as a microcomputer or a CPU (Central Processing Unit), and hardware such as computer peripheral circuits and devices. In this embodiment, the transmitting controller 20 is configured by a control board on which a microcomputer is mounted. The transmitting controller 20 has a functional configuration that is a combination of hardware and software such as a program executed by the computer, and includes an imaging control unit 21, a marker control unit 22, a transmitting GPS signal receiving unit 23, a transmitting reference signal transmitting unit 24, and a data transmitting unit 25.

[0018] The photographing control unit 21 controls the operation of the photographing device 3. Specifically, the photographing control unit 21 outputs a command to the photographing device 3 to perform photographing. The photographing control unit 21 executes encoding processing of the data of the video photographed by the photographing device 3. Note that the encoding processing of the video data may be performed using a function provided in the photographing device 3. The marker control unit 22 controls the blinking operation of the blinking marker 4 .

[0019] The transmitting GPS signal receiving unit 23 receives, for example, a GPS signal at the shooting location. The GPS signal includes highly accurate time information. 2, the transmitting-side reference signal transmitter 24 transmits a transmitting-side reference signal Sg1 synchronized with the GPS signal received by the transmitting-side GPS signal receiver 23. An example of the transmitting-side reference signal Sg1 synchronized with the GPS signal is a 1PPS (Pulse Per Second) signal, which is a pulse signal whose signal state switches at predetermined time intervals. The transmitting-side reference signal Sg1 (1PPS signal) is a pulse signal that periodically repeats ON and OFF within one second.

[0020] The marker control unit 22 causes the marker light 4m of the blinking marker 4 to blink periodically, for example, every second, based on the transmitting-side reference signal Sg1 (1PPS signal) transmitted by the transmitting-side reference signal transmission unit 24. The blinking marker 4 periodically alternates between an on state and an off state every second.

[0021] The data transmission unit 25 transmits data of the video captured by the camera device 3. The data transmission unit 25 executes processing for transmitting the video data encoded by the camera control unit 21. Note that the data transmission unit 25, which is responsible for the processing for transmitting the data of the video captured by the camera device 3, may use a function provided in the camera device 3.

[0022] The receiving unit 5 is installed at a remote location away from the shooting location. The remote location is at least a distance from the shooting location that makes it impossible or difficult to directly see the shooting location. There is no limitation on the distance from the shooting location to the remote location. In an embodiment of the present disclosure, the receiving unit 5 is installed at a location (remote location) where data communication is possible between the receiving unit 5 and the transmitting unit 2 via various networks 100. The receiving unit 5 includes a receiving controller 50, a display device 6, and a first blinking detection unit .

[0023] The receiving controller 50 can be configured using a computer such as a microcomputer or a CPU (Central Processing Unit), and hardware such as computer peripheral circuits and devices. In this embodiment, the receiving controller 50 is configured by a control board on which a microcomputer is mounted. The receiving controller 50 has a functional configuration formed by a combination of hardware and software such as a program executed by the computer, and includes a data receiving unit 51, a display control unit 52, a receiving GPS signal receiving unit 53, a receiving reference signal transmitting unit 54, and a delay time information output unit 55.

[0024] The data receiving unit 51 receives the video data transmitted from the data transmitting unit 25 via the network 100 . The display control unit 52 controls the display of video on the display device 6. The display control unit 52 performs processes such as decoding the video data received by the data receiving unit 51 and displaying the video based on the decoded video data. Note that the data receiving unit 51, which is responsible for receiving the video data transmitted from the data transmitting unit 25, and the display control unit 52, which is responsible for decoding the received video data and displaying the video, may use functions provided in the display device 6.

[0025] The receiving-side GPS signal receiving unit 53 receives the GPS signal at the remote location. The receiving-side reference signal transmitter 54 transmits a receiving-side reference signal Sg2 (1PPS signal) synchronized with the GPS signal received by the receiving-side GPS signal receiver 53.

[0026] The display device 6 displays an image based on the data received by the data receiving unit 51 under the control of the display control unit 52. The image displayed on the display device 6 includes an image of the subject T and the blinking marker 4 captured by the photographing device 3. In other words, a part of the image displayed on the display device 6 displays the blinking of the marker light 4m of the blinking marker 4.

[0027] The first blinking detection unit 7 detects the blinking of the marker light 4m in the image displayed on the display device 6. An example of the first blinking detection unit 7 is a photodiode. The position of the blinking marker 4 is fixed relative to the image capturing device 3. Therefore, the position of the marker light 4m of the blinking marker 4 is constant in the image displayed on the display device 6. The first blinking detection unit 7 is fixed to match the position of the marker light 4m of the blinking marker 4 in the image displayed on the display device 6.

[0028] The first blinking detection unit 7 detects the blinking state (on or off) of the marker light 4m. The first blinking detection unit 7 outputs a blinking signal Sgm indicating the blinking state of the marker light 4m to the delay time information output unit 55.

[0029] The blinking signal Sgm is a waveform signal that indicates switching of the signal state in response to the lighting and extinguishing of the blinking marker 4. This blinking signal Sgm includes a delay time with respect to the timing at which the blinking marker 4 of the transmitting unit 2 blinks the marker light based on the transmitting side reference signal Sg1 (1PPS signal). The delay time of the blinking signal Sgm with respect to the timing at which the blinking marker 4 blinks the marker light matches the video transmission delay time from when the video captured by the imaging device 3 is displayed on the display device 6.

[0030] The delay time information output unit 55 outputs information about the video transmission delay time Td from when the video is captured by the image capturing device 3 to when it is displayed on the display device 6, based on the blinking signal Sgm indicating the blinking state of the marker light 4m detected by the first blink detection unit 7 and the receiving-side reference signal Sg2. An example of the delay time information output unit 55 is an oscilloscope that outputs (displays) the receiving-side reference signal Sg2 and the blinking signal Sgm as visible waveform information. In this case, the delay time information output unit 55 displays the waveform of the receiving-side reference signal Sg2 and the waveform of the blinking signal Sgm in parallel as information about the video transmission delay time Td. The delay time information output unit 55 outputs information about the video transmission delay time Td based on the timing at which the signal state of the receiving-side reference signal Sg2 changes and the timing at which the signal state of the blinking signal Sgm changes. The person in charge of the receiving unit 5 can ascertain the video transmission delay time Td from the time difference between the receiving side reference signal Sg2 and the blinking signal Sgm, which is displayed on the delay time information output section 55.

[0031] Here, the video transmission delay time Td can be, for example, the time difference between when the receiving-side reference signal Sg2 turns ON and when the blinking signal Sgm switches from an OFF state to an ON state. The video transmission delay time Td is not limited to this, and can also be, for example, the time difference between when the receiving-side reference signal Sg2 turns OFF and when the blinking signal Sgm switches from an ON state to an OFF state.

[0032] The delay time information output unit 55 may use a function of the oscilloscope to calculate the video transmission delay time Td based on the timing at which the signal state of the receiving side reference signal Sg2 changes and the timing at which the signal state of the blinking signal Sgm changes. The oscilloscope as the delay time information output unit 55 outputs (displays) the calculated value of the video transmission delay time Td. In addition, the delay time information output unit 55 may calculate the difference between the timing at which the signal state of the receiving side reference signal Sg2 changes and the timing at which the signal state of the blinking signal Sgm changes as the video transmission delay time Td based on the waveform of the receiving side reference signal Sg2 and the waveform of the blinking signal Sgm.

[0033] (Video transmission delay time measurement procedure) As shown in FIG. 3, the video transmission delay time measuring method according to an embodiment of the present disclosure includes step S11 of receiving a GPS signal at a shooting location, step S12 of transmitting a transmitting-side reference signal Sg1, step S13 of blinking a marker light, step S14 of shooting a video, step S15 of transmitting video data, step S21 of receiving the video data, step S22 of displaying the video, step S23 of detecting the blinking of the marker light, step S24 of receiving a GPS signal at a remote location, step S25 of transmitting a receiving-side reference signal Sg2, and step S26 of outputting information related to the video transmission delay time Td.

[0034] In step S11 of receiving a GPS signal at a photography location, the transmission-side GPS signal receiving section 23 of the transmission unit 2 receives a GPS signal at the photography location.

[0035] In step S12 of transmitting a transmitting-side reference signal Sg1, the transmitting-side reference signal Sg1 (see FIG. 2) synchronized with the GPS signal Sg0 received by the transmitting-side GPS signal receiving unit 23 is transmitted.

[0036] In step S13 of flashing the marker light, the marker control unit 22 flashes the marker light periodically, for example, every second, using the flashing marker 4 based on the transmitting side reference signal Sg1 (1PPS signal) transmitted by the transmitting side reference signal transmission unit 24.

[0037] In step S14 of capturing an image, under the control of the photography control unit 21, the photography device 3 captures an image including the photography target T and the blinking of the marker light 4m of the blinking marker 4 at the photography location.

[0038] In step S15 of transmitting the video data, the photography control unit 21 executes encoding processing for the video data captured by the photographing device 3. Furthermore, the data transmission unit 25 executes processing for transmitting the video data encoded by the photography control unit 21. As a result, the data of the video captured by the photographing device 3 is transmitted to the receiving unit 5 via the network 100.

[0039] In step S21 of receiving video data, the data receiving unit 51 receives the video data transmitted from the data transmitting unit 25 via the network 100.

[0040] In step S22 of displaying the video, the display control unit 52 performs processing such as decoding the video data received by the data receiving unit 51 and displaying the video based on the decoded video data. As a result, the display device 6 displays the video based on the data received by the data receiving unit 51 under the control of the display control unit 52. The video displayed on the display device 6 includes the image of the subject T and the marker light 4m of the flashing marker 4 captured by the imaging device 3.

[0041] In step S23 of detecting blinking of the marker light, the first blinking detection unit 7 detects blinking of the marker light 4m in the image displayed on the display device 6. The first blinking detection unit 7 detects the blinking state (on or off) of the marker light 4m. The first blinking detection unit 7 outputs a blinking signal Sgm indicating the blinking state of the marker light 4m to the delay time information output unit 55.

[0042] In step S24 of receiving a GPS signal at a remote location, the receiving-side GPS signal receiving section 53 receives a GPS signal at the remote location where the receiving unit 5 is located.

[0043] In step S25 of transmitting a receiving-side reference signal Sg2, receiving-side reference signal transmitter 54 transmits receiving-side reference signal Sg2 (see FIG. 2 ) synchronized with the GPS signal received by receiving-side GPS signal receiver 53. Receiving-side reference signal transmitter 54 outputs the transmitted receiving-side reference signal Sg2 to delay time information output unit 55.

[0044] In step S26 of outputting information about the video transmission delay time Td, the delay time information output unit 55 outputs information about the video transmission delay time Td based on the blinking signal Sgm and the receiving-side reference signal Sg2. If the delay time information output unit 55 is an oscilloscope, the video transmission delay time Td can be determined based on waveform information of the receiving-side reference signal Sg2 and the blinking signal Sgm that are held alongside the oscilloscope. Alternatively, the delay time information output unit 55 may calculate the video transmission delay time Td based on the timing at which the signal state of the receiving-side reference signal Sg2 changes and the timing at which the signal state of the blinking signal Sgm changes.

[0045] (Action and effect) According to the video transmission delay time measuring system 1A configured as described above, the camera device 3 of the transmission unit 2 arranged at the shooting location captures video of the subject, and the video data is transmitted to the receiving unit 5 by the data transmission section 25. The receiving unit 5 displays the video based on the received video data on the display device 6. The transmitting unit 2 transmits a transmitting-side reference signal Sg1 synchronized with the GPS signal received by the transmitting-side GPS signal receiving unit 23. Meanwhile, the receiving unit 5 transmits a receiving-side reference signal Sg2 synchronized with the GPS signal received by the receiving-side GPS vibration receiving unit. As a result, the transmitting-side reference signal Sg1 and the receiving-side reference signal Sg2 synchronized in time are transmitted between the shooting location and a remote location separated from the shooting location. In the transmitting unit 2, the marker light 4m of the blinking marker 4 blinks periodically based on the transmitting-side reference signal Sg1. The photographing device 3 photographs an image including the blinking marker 4 along with the subject. The display device 6 of the receiving unit 5 displays an image of the subject and the blinking marker light 4m of the blinking marker 4. The first blink detection unit 7 detects the blinking of the marker light 4m in the image displayed on the display device 6. Therefore, the delay time information output unit 55 outputs information regarding the image transmission delay time Td from when the image is photographed by the photographing device 3 to when the image is displayed on the display device 6, based on the blink signal Sgm indicating the blinking state of the marker light 4m detected by the first blink detection unit 7 and the receiving-side reference signal Sg2. Here, the receiving-side reference signal Sg2 is synchronized with the transmitting-side reference signal Sg1, and the blinking of the marker light 4m is performed based on the transmitting-side reference signal Sg1. In other words, the time difference between the blinking signal Sgm indicating the blinking state of the marker light 4m detected by the first blink detection unit 7 and the receiving-side reference signal Sg2 is the time difference between the blinking of the marker light 4m at the shooting location and the blinking of the marker in the image displayed at a distant location, i.e., the video transmission delay time Td. Here, the delay time information output unit 55 may output (display) the time difference between the blinking signal Sgm indicating the blinking state of the marker light 4m detected by the first blink detection unit 7 and the receiving side reference signal Sg2 as information regarding the video transmission delay time Td using visible waveform information, etc. In addition, the delay time information output unit 55 may calculate the time difference between the blinking signal Sgm indicating the blinking state of the marker light 4m detected by the first blink detection unit 7 and the receiving side reference signal Sg2 as information regarding the video transmission delay time Td, and output the calculated numerical value as the video transmission delay time Td. In this way, the video transmission delay time Td can be obtained based on the blinking of the marker light 4m of the blinking marker 4 displayed together with the subject in the video captured by the camera 3. Therefore, the video transmission delay time can be measured while actually capturing the video.

[0046] Furthermore, since the transmitting side reference signal Sg1 and the receiving side reference signal Sg2 are pulse signals, and the blinking signal Sgm is a waveform signal that indicates the switching of the signal state in response to the lighting and extinguishing of the blinking marker 4, the video transmission delay time Td can be easily determined by comparing the receiving side reference signal Sg2 and the blinking signal Sgm.

[0047] Furthermore, when the delay time information output unit 55 is an oscilloscope, the image transmission delay time Td can be visually and easily grasped by displaying the receiving side reference signal Sg2 and the blinking signal Sgm side by side.

[0048] In addition, the delay time information output unit 55 can easily grasp the video transmission delay time Td based on the timing at which the signal state of the receiving side reference signal Sg2 changes and the timing at which the signal state of the blinking signal Sgm changes.

[0049] Furthermore, the delay time information output unit 55 can easily and accurately grasp the video transmission delay time Td by calculating the video transmission delay time Td based on the timing at which the signal state of the receiving side reference signal Sg2 changes and the timing at which the signal state of the blinking signal Sgm changes.

[0050] Furthermore, by fixing the blinking marker 4 and the photographing device 3 with the fixing member 31, the blinking marker 4 is prevented from moving relative to the photographing device 3 due to vibrations or the like in the image photographed by the photographing device 3. Therefore, the position of the blinking marker 4 is prevented from shifting in the image displayed on the display device 6, and the first blinking detection unit 7 can effectively detect the blinking of the marker light 4m.

[0051] (Modification of the first embodiment) In the first embodiment, the measurement of the video transmission delay time by the video transmission delay time measurement method as shown in FIG. 3 may be performed continuously while the image is being captured by the image capturing device 3, or may be performed intermittently at appropriate time intervals.

[0052] Second Embodiment Next, a second embodiment of the video transmission delay time measuring system and video transmission delay time measuring method according to the present disclosure will be described. In the second embodiment described below, components common to the first embodiment will be denoted by the same reference numerals in the drawings, and their description will be omitted. In addition to the components shown in the first embodiment, the second embodiment differs from the first embodiment in that it includes a configuration for adjusting the blinking cycle of the marker light 4m in the blinking marker 4 in accordance with the video transmission delay time.

[0053] FIG. 4 is a diagram showing the configuration of the video transmission delay time measuring system according to the second embodiment. As shown in Figure 4, in addition to the configuration of the video transmission delay time measurement system 1A, the video transmission delay time measurement system 1B further includes a receiving side blinking marker 8, a second blinking detection unit 72, a delay time abnormality determination unit 56A, and a blinking period adjustment unit 26A.

[0054] The receiving-side blinking marker 8 is provided in the receiving unit 5. The receiving-side blinking marker 8 periodically blinks a marker light based on the receiving-side reference signal Sg2. The receiving-side blinking marker 8 repeatedly blinks different types of marker lights 8m alternately in a predetermined order based on the receiving-side reference signal Sg2. In an embodiment of the present disclosure, the receiving-side blinking marker 8 repeatedly blinks marker lights 8m of different colors (e.g., red marker light 8mR, blue marker light 8mB, and green marker light 8mG) in this order.

[0055] In an embodiment of the present disclosure, the blinking marker 4 of the transmitting unit 2 repeatedly blinks different types of marker lights 4m alternately in a predetermined sequence based on the transmitting-side reference signal Sg1. In an embodiment of the present disclosure, the blinking marker 4 repeatedly blinks different colored marker lights 4m (e.g., red marker light 4mR, blue marker light 4mB, and green marker light 4mG) in this sequence. In other words, the receiving-side blinking marker 8 and the blinking marker 4 repeatedly blink the same types of marker lights 8m, 4m in the same sequence.

[0056] The second blinking detection unit 72 is provided in the receiving unit 5. The second blinking detection unit 72 is, for example, a photodiode, and detects the blinking of the marker light 8m in the receiving-side blinking marker 8. As shown in Fig. 5, the blinking signal Sgr of the marker light 8m of the receiving-side blinking marker 8 detected by the second blinking detection unit 72 is synchronized with the receiving-side reference signal Sg2.

[0057] The delay time abnormality determination unit 56A is provided in the receiving unit 5. The delay time abnormality determination unit 56A determines whether or not there is an abnormality in the video transmission delay time Td acquired by the delay time information output unit 55. Specifically, the delay time abnormality determination unit 56A determines whether or not the video transmission delay time Td is equal to or longer than one period of the receiving-side reference signal Sg2 (one second in the above example). To do this, the video transmission delay time Td is acquired using the procedure shown in Fig. 3. The delay time abnormality determination unit 56A compares the blinking signal Sgm used when acquiring the video transmission delay time Td with the blinking signal Sgr of the receiving-side blinking marker 8 synchronized with the blinking signal Sgm. If the type (color) of the blinking signal Sgm used when acquiring the video transmission delay time Td is the same as the type of the blinking signal Sgr of the receiving-side blinking marker 8, the video transmission delay time Td is less than one period of the receiving-side reference signal Sg2. On the other hand, as shown in Fig. 5, if the type (color) of the blinking signal Sgm used to acquire the video transmission delay time Td is different from the type of the blinking signal Sgr of the receiving-side blinking marker 8, it can be determined that the video transmission delay time Td is equal to or longer than one period of the receiving-side reference signal Sg2. In this case, the blinking period adjustment unit 26A adjusts the blinking period of the marker light 4m of the blinking marker 4. For example, as shown in Fig. 6, the blinking period adjustment unit 26A adjusts the period of the transmitting-side reference signal Sg1 to be twice as long.

[0058] Thereafter, the video transmission delay time Td is acquired again in the procedure shown in Fig. 3. The delay time abnormality determination unit 56A determines whether the blinking signal Sgm used when acquiring the video transmission delay time Td and the blinking signal Sgr of the receiving side blinking marker 8 synchronized with the blinking signal Sgm are of the same type. Using this procedure, the blinking period adjustment unit 26A adjusts the period of the transmitting side reference signal Sg1 to twice the length until the blinking signal Sgm used to acquire the video transmission delay time Td and the blinking signal Sgr of the receiving side blinking marker 8 synchronized with the blinking signal Sgm are of the same type.

[0059] According to the video transmission delay time measuring system 1B described above, in addition to the same effects as those of the first embodiment described above, when the video transmission delay time Td is longer than the blinking cycle of the marker light of the blinking marker 4, the blinking cycle adjustment unit 26A can make the blinking cycle of the marker light longer than the video transmission delay time Td. This makes it possible to more easily grasp the video transmission delay time Td.

[0060] Furthermore, according to the above embodiment, the second blinking detection unit 72 detects the periodic blinking of the marker light of the receiving-side blinking marker 8 based on the receiving-side reference signal Sg2. The blinking cycle adjustment unit 26A adjusts the blinking cycle of the marker light of the blinking marker 4 based on the marker light of the blinking marker 4 detected by the first blinking detection unit 7 and the marker light of the receiving-side blinking marker 8 detected by the second blinking detection unit 72. For example, if the type of marker light of the blinking marker 4 detected by the first blinking detection unit 7 differs from the type of marker light of the receiving-side blinking marker 8 detected by the second blinking detection unit 72, it can be determined that the video transmission delay time Td is longer than the blinking cycle of the marker light of the blinking marker 4. In this case, the blinking cycle adjustment unit 26A adjusts the blinking cycle of the marker light of the blinking marker 4, thereby accurately determining the video transmission delay time Td.

[0061] In the second embodiment, the marker light 4m of the flashing marker 4 and the marker light 8m of the receiving side flashing marker 8 are made to flash multiple types of marker light 4m, 8m by making them different colors, but the marker light 4m of the flashing marker 4 and the marker light 8m of the receiving side flashing marker 8 may also be made to flash multiple types of marker light by, for example, making them different flashing patterns.

[0062] In the second embodiment, the blinking cycle adjustment unit 26A adjusts the blinking cycle of the marker light of the blinking marker 4 based on the type of marker light of the blinking marker 4 detected by the first blink detection unit 7 and the type of marker light of the receiving-side blinking marker 8 detected by the second blink detection unit 72, but this is not limiting. For example, a person in charge may visually check the type (color) of the marker light of the blinking marker 4 displayed on the display device 6 and the type (color) of the marker light of the receiving-side blinking marker 8 and make a judgment.

[0063] In the second embodiment, if the type (color) of the blinking signal Sgm used to acquire the video transmission delay time Td differs from the type of the blinking signal Sgr of the receiving-side blinking marker 8, the video transmission delay time Td is determined to be equal to or longer than one period of the receiving-side reference signal Sg2, but this is not limiting. For example, a person in charge may visually check the blinking signals Sgm and Sgr and make a determination based on the difference in color.

[0064] Third Embodiment Next, a third embodiment of the video transmission delay time measuring system and video transmission delay time measuring method according to the present disclosure will be described. In the third embodiment described below, components common to the first embodiment will be denoted by the same reference numerals in the drawings, and their description will be omitted. In the third embodiment, the blinking period of the marker light 4m in the blinking marker 4 is adjusted using a different configuration from that shown in the second embodiment.

[0065] FIG. 7 is a diagram showing the configuration of the video transmission delay time measuring system according to the third embodiment. As shown in FIG. 7, the video transmission delay time measurement system 1C further includes a transmission side time information display device 200, a time difference acquisition unit 300, and a blinking cycle adjustment unit 26B in addition to the configuration of the video transmission delay time measurement system 1A.

[0066] The transmitter's time information display device 200 is provided in the transmitting unit 2. The transmitter's time information display device 200 displays photographing location time information Tp at the photographing location. The transmitter's time information display device 200 is, for example, a smartphone, tablet terminal, or personal computer, and can acquire time information distributed from an external time information output unit, for example, time information distributed from an NTP (Network Time Protocol) server, as a synchronization signal with a larger synchronization error than a GPS signal. The transmitter's time information display device 200 displays the acquired time information as photographing location time information Tp at the photographing location on a monitor screen or the like provided in the transmitter's time information display device 200. The transmitter's time information display device 200 is positioned within the field of view of the photographing device 3. The photographing device 3 then photographs an image including the photographing subject T, the marker light 4m of the blinking marker 4, and the photographing location time information Tp displayed on the transmitting side time information display device 200. As a result, the display device 6 displays the photographing location time information Tp in addition to the images of the photographing subject T and the marker light 4m.

[0067] The time difference acquisition unit 300 is provided in the receiving unit 5. The time difference acquisition unit 300 is, for example, a smartphone, a tablet terminal, a personal computer, etc., and can acquire time information distributed from an external time information output unit, for example, time information distributed from an NTP server. This allows the time difference acquisition unit 300 to acquire, at the remote location, remote location time information that is substantially synchronized with the shooting location time information Tp.

[0068] The time difference acquisition unit 300 also includes a camera 301 capable of capturing the shooting location time information Tp displayed on the display device 6. The time difference acquisition unit 300 reads the time displayed as the shooting location time information Tp captured by the camera 301 using appropriate character recognition processing. The time difference acquisition unit 300 acquires the difference between the read shooting location time information Tp and the distant location time information acquired at the distant location.

[0069] The difference between the shooting location time information Tp and the distant location time information acquired at the distant location includes the video transmission delay time until the shooting location time information Tp captured by the shooting device 3 is displayed on the display device 6. The time difference acquisition unit 300 determines whether the difference acquired in this manner is equal to or greater than one cycle of the receiving side reference signal Sg2 (one second in the above example). If the acquired difference is equal to or greater than one cycle of the receiving side reference signal Sg2, the time difference acquisition unit 300 notifies the blinking cycle adjustment unit 26B of the transmission unit 2 of the difference between the shooting location time information Tp and the distant location time information acquired at the distant location via the network 100 or the like using the communication function of the time difference acquisition unit 300.

[0070] Based on notification from the time difference acquisition unit 300, the blinking cycle adjustment unit 26B adjusts the blinking cycle of the marker light 4m of the blinking marker 4 according to the difference between the shooting location time information Tp and the separated location time information acquired at the separated location.

[0071] According to the video transmission delay time measuring system 1C described above, in addition to the same effects as those of the first and second embodiments described above, when the photographing device 3 photographs a video including the photographing location time information Tp displayed on the transmitting side time information display device 200, the time difference acquisition unit 300 acquires the difference between the photographing location time information Tp displayed on the transmitting side time information display device 200 and the distant location time information acquired at the distant location. If the difference between the acquired photographing location time information Tp and the distant location time information is large, the blinking cycle adjustment unit 26B adjusts the blinking cycle of the marker light, making it possible to accurately determine the video transmission delay time Td.

[0072] <Fourth embodiment> Next, a fourth embodiment of the video transmission delay time measurement system and video transmission delay time measurement method according to the present disclosure will be described. In the fourth embodiment described below, components common to the first and fourth embodiments will be denoted by the same reference numerals in the drawings, and their description will be omitted. The fourth embodiment differs from the first to third embodiments in that it has a fault diagnosis function for the video transmission delay time measurement system.

[0073] 8 shows a video transmission delay time measuring system 1D according to a fourth embodiment of the video transmission delay time measuring system and video transmission delay time measuring method, which can be configured in combination with the video transmission delay time measuring systems 1A to 1C shown in the first to third embodiments. In the configuration shown in Fig. 8, the video transmission delay time measuring system 1D includes a fault diagnosis unit 58 in addition to the configuration of the video transmission delay time measuring system 1A shown in the first embodiment.

[0074] In the video transmission delay time measuring system 1D, a plurality of blinking markers 4 are provided. The photographing direction of the photographing device 3 can be changed by a drive device (not shown). The photographing device 3 and the blinking marker 4 can be moved relative to each other so as to return to a fixed position in accordance with the blinking cycle of the blinking marker 4. The blinking markers 4 blink synchronously based on the transmitting side reference signal Sg1 (see FIG. 2). The photographing device 3 changes its photographing direction so as to sequentially photograph the blinking markers 4 at the timing when the blinking markers 4 are lit. As a result, the photographing device 3 sequentially photographs different blinking markers 4 for each blinking cycle of the blinking markers 4.

[0075] As described in the first embodiment above, the receiving controller 50 can obtain the video transmission delay time Td using the blinking signal Sgm that indicates the blinking state of the blinking marker 4 contained in the video captured by the camera device 3.

[0076] The fault diagnosis unit 58 is provided in the receiving controller 50. The fault diagnosis unit 58 diagnoses whether or not a fault has occurred in the transmission unit 2 based on the video captured by the image capture device 3. The fault diagnosis unit 58 compares the videos captured sequentially at the blinking timing of the multiple blinking markers 4. If there is no change in the captured background video in the videos captured sequentially at the blinking timing of the multiple blinking markers 4, the fault diagnosis unit 58 can diagnose that the transmission unit 2 has malfunctioned for some reason and has stopped operating. If the fault diagnosis unit 58 diagnoses that a fault has occurred, it can invalidate the video transmission delay time Td acquired at that time. Furthermore, if the fault diagnosis unit 58 diagnoses that a fault has occurred, it may notify the outside of the occurrence of the fault.

[0077] According to the video transmission delay time measuring system 1D as described above, in addition to the same operational effects as those of the first to third embodiments, by relatively moving the camera device 3 and the blinking marker 4 so that they return to their home positions in accordance with the blinking cycle of the blinking marker 4, if at least one of the camera device 3 and the blinking marker 4 is not operating normally, the camera device 3 will not be able to properly capture the blinking of the blinking marker 4. Therefore, it is possible to easily determine whether the camera device 3 and the blinking marker 4 are operating normally.

[0078] In the fourth embodiment, a plurality of blinking markers 4 are provided and the shooting direction of the camera device 3 is changed, but the present invention is not limited to this. The blinking markers 4 may be moved relative to the camera device 3 without changing the shooting direction of the camera device 3.

[0079] Furthermore, although the fault diagnosis unit 58 performs fault diagnosis based on the video captured by the image capturing device 3, the present invention is not limited to this. For example, if a malfunction occurs in the photographing device 3 or the blinking marker 4 on the transmitting unit 2 side, the blinking period of the marker light 4m in the image captured by the photographing device 3 will become longer than usual (including cases where it stops blinking). Therefore, it is determined whether the video transmission delay time Td acquired by the delay time information output unit 55 exceeds a preset threshold, and if the video transmission delay time Td is equal to or greater than the threshold, it can be determined that a failure has occurred on the transmitting unit 2 side.

[0080] In addition, in the blinking signal Sgm, the lighting duration or extinguishing duration of the marker light 4m is It is determined whether or not a preset threshold is exceeded, and if the duration of lighting or lighting out is equal to or greater than the threshold, it can be determined that a failure has occurred on the transmitting unit 2 side.

[0081] The diagnosis by the fault diagnosis section 58 shown in the fourth embodiment may be performed at the discretion of the person in charge of the receiving unit 5.

[0082] In addition, in each of the above embodiments, the photography control unit 21 controls the operation of the photography device 3, but this is not limited to this. For example, an existing camera or the like may be used as the photography device 3, and the photography device 3 may be operated by a person in charge, with the photography operation being controlled by the photography device 3 itself. Furthermore, the encoding process of the data of the video captured by the image capturing device 3 may be performed by a separate encoder or the like, instead of by the image capturing control unit 21.

[0083] <Additional Notes> The video transmission delay time measuring systems 1A to 1D and the video transmission delay time measuring methods described in the respective embodiments can be understood, for example, as follows.

[0084] (1) A video transmission delay time measuring system 1A to 1D according to a first aspect includes a transmitting unit 2 arranged at a shooting location and a receiving unit 5 installed at a remote location away from the shooting location, the transmitting unit 2 includes a transmitting-side GPS signal receiving unit 23 that receives a GPS signal at the shooting location, a transmitting-side reference signal transmitting unit 24 that transmits a transmitting-side reference signal Sg1 synchronized with the GPS signal received by the transmitting-side GPS signal receiving unit 23, a blinking marker 4 that periodically blinks a marker light based on the transmitting-side reference signal Sg1, a photographing device 3 that photographs a video including a subject and the blinking marker 4 at the shooting location, and a data transmitting unit 25 that transmits data of the video photographed by the photographing device 3, and the receiving unit 5 includes a transmitting-side GPS signal receiving unit 23 that receives a GPS signal at the shooting location, a transmitting-side reference signal transmitting unit 24 that transmits a transmitting-side reference signal Sg1 synchronized with the GPS signal received by the transmitting-side GPS signal receiving unit 23, a blinking marker 4 that periodically blinks a marker light based on the transmitting-side reference signal Sg1, a photographing device 3 that photographs a video including a subject and the blinking marker 4 at the shooting location, and a data transmitting unit 25 that transmits data of the video photographed by the photographing device 3. a display device 6 that displays an image based on the received image data; a first blinking detection unit 7 that detects blinking of the marker light in the image displayed on the display device 6; a receiving-side GPS signal receiving unit 53 that receives a GPS signal at the distant location; a receiving-side reference signal transmitting unit 54 that transmits a receiving-side reference signal Sg2 synchronized with the GPS signal received by the receiving-side GPS signal receiving unit 53; and a delay time information output unit 55 that outputs information regarding a video transmission delay time Td from when the image is captured by the imaging device 3 to when it is displayed on the display device 6, based on the blinking signal Sgm that indicates the blinking state of the marker light detected by the first blinking detection unit 7 and the receiving-side reference signal Sg2.

[0085] In the video transmission delay time measurement systems 1A to 1D, a video of a subject is captured by a camera 3 of a transmission unit 2 arranged at a shooting location, and the video data is transmitted to a receiving unit 5 by a data transmission unit 25. The receiving unit 5 displays a video based on the received video data on a display device 6. The transmitting unit 2 transmits a transmitting-side reference signal Sg1 synchronized with the GPS signal received by the transmitting-side GPS signal receiving unit 23. Meanwhile, the receiving unit 5 transmits a receiving-side reference signal Sg2 synchronized with the GPS signal received by the receiving-side GPS vibration receiving unit. As a result, the transmitting-side reference signal Sg1 and the receiving-side reference signal Sg2 synchronized in time are transmitted between the shooting location and a remote location separated from the shooting location. In the transmitting unit 2, the marker light of the blinking marker 4 blinks periodically based on the transmitting-side reference signal Sg1. The photographing device 3 photographs an image including the blinking marker 4 along with the subject. The display device 6 of the receiving unit 5 displays an image of the subject and the blinking marker light of the blinking marker 4. The first blinking detection unit 7 detects the blinking of the marker light in the image displayed on the display device 6. Therefore, the delay time information output unit 55 outputs information regarding the image transmission delay time Td from when the image is photographed by the photographing device 3 to when the image is displayed on the display device 6, based on the blinking signal Sgm indicating the blinking state of the marker light detected by the first blinking detection unit 7 and the receiving-side reference signal Sg2. Here, the receiving-side reference signal Sg2 is synchronized with the transmitting-side reference signal Sg1, and the blinking of the marker light is performed based on the transmitting-side reference signal Sg1. In other words, the time difference between the blinking signal Sgm indicating the blinking state of the marker light detected by the first blink detection unit 7 and the receiving-side reference signal Sg2 is the time difference between the blinking of the marker light at the shooting location and the blinking of the marker in the video displayed at a distant location, i.e., the video transmission delay time Td. Here, the delay time information output unit 55 may output (display) the time difference between the blinking signal Sgm indicating the blinking state of the marker light detected by the first blink detection unit 7 and the receiving side reference signal Sg2 as information regarding the video transmission delay time Td using visible waveform information or the like. In addition, the delay time information output unit 55 may calculate the time difference between the blinking signal Sgm indicating the blinking state of the marker light detected by the first blink detection unit 7 and the receiving side reference signal Sg2 as information regarding the video transmission delay time Td, and output the calculated numerical value as the video transmission delay time Td. In this way, the video transmission delay time Td can be obtained based on the blinking of the marker light of the blinking marker 4 displayed together with the subject in the video captured by the camera 3. Therefore, the video transmission delay time can be measured while actually capturing the video.

[0086] (2) The video transmission delay time measuring systems 1A to 1D according to the second aspect are the video transmission delay time measuring systems 1A to 1D of (1), in which the transmitting side reference signal Sg1 and the receiving side reference signal Sg2 are pulse signals whose signal state changes at predetermined time intervals, and the blinking signal Sgm is a waveform signal that indicates the change in signal state in response to the lighting and extinguishing of the blinking marker 4.

[0087] As a result, since the transmitting side reference signal Sg1 and the receiving side reference signal Sg2 are pulse signals and the blinking signal Sgm is a waveform signal that indicates the change in signal state according to the lighting and extinguishing of the blinking marker 4, the video transmission delay time Td can be easily determined by comparing the receiving side reference signal Sg2 and the blinking signal Sgm.

[0088] (3) The video transmission delay time measuring systems 1A to 1D according to the third aspect are the video transmission delay time measuring systems 1A to 1D of (2), in which the delay time information output unit 55 is an oscilloscope that displays the receiving side reference signal Sg2 and the blinking signal Sgm side by side.

[0089] By displaying the receiving-side reference signal Sg2 and the blinking signal Sgm side by side on an oscilloscope, the video transmission delay time Td can be easily grasped visually.

[0090] (4) The video transmission delay time measuring systems 1A to 1D according to the fourth aspect are the video transmission delay time measuring systems 1A to 1D of (2) or (3), and the delay time information output unit 55 outputs information about the video transmission delay time Td based on the timing at which the signal state of the receiving side reference signal Sg2 changes and the timing at which the signal state of the blinking signal Sgm changes.

[0091] This allows the delay time information output unit 55 to easily grasp the video transmission delay time Td based on the timing at which the signal state of the receiving side reference signal Sg2 changes and the timing at which the signal state of the blinking signal Sgm changes.

[0092] (5) The video transmission delay time measurement systems 1A to 1D according to the fifth aspect are the video transmission delay time measurement systems 1A to 1D of (4), in which the delay time information output unit 55 calculates the video transmission delay time Td based on the timing at which the signal state of the receiving side reference signal Sg2 changes and the timing at which the signal state of the blinking signal Sgm changes, and outputs the value of the calculated video transmission delay time Td.

[0093] As a result, the delay time information output unit 55 can easily and accurately grasp the video transmission delay time Td by calculating the video transmission delay time Td based on the timing when the signal state of the receiving side reference signal Sg2 changes and the timing when the signal state of the blinking signal Sgm changes.

[0094] (6) The video transmission delay time measurement system 1A to 1D relating to the sixth aspect is any one of the video transmission delay time measurement systems 1A to 1D of (1) to (5), and further includes a fixing member 31 for fixing the flashing marker 4 and the photographing device 3.

[0095] As a result, in an image captured by the photographing device 3, for example, when the photographing device 3 and the blinking marker 4 are attached to a moving body such as a ship or vehicle, or various machines, the blinking marker 4 is prevented from moving relative to the photographing device 3 due to vibrations, etc. Therefore, in an image displayed on the display device 6, the position of the blinking marker 4 is prevented from shifting, and the first blink detection unit 7 can effectively detect the blinking of the marker light.

[0096] (7) The video transmission delay time measuring system 1B, 1C according to the seventh aspect is any one of the video transmission delay time measuring systems 1B, 1C according to (1) to (6), wherein the transmitting unit 2 further includes a blinking period adjusting unit 26A, 26B capable of adjusting the blinking period of the marker light in the blinking marker 4.

[0097] This allows the blinking period of the marker light to be made longer than the video transmission delay time Td, for example, when the video transmission delay time Td is longer than the blinking period of the marker light of the blinking marker 4. This makes it easier to grasp the video transmission delay time Td.

[0098] (8) The video transmission delay time measuring system 1B according to the eighth aspect is the video transmission delay time measuring system 1B of (7), wherein the receiving unit 5 further includes a receiving-side blinking marker 8 that periodically blinks a marker light 8m based on the receiving-side reference signal Sg2, and a second blinking detection unit 72 that detects the blinking of the marker light 8m in the receiving-side blinking marker 8, wherein the blinking marker 4 and the receiving-side blinking marker 8 are each capable of blinking multiple types of the marker lights 4m, 8m in the same order, and the blinking cycle adjustment unit 26A adjusts the blinking cycle of the marker light in the blinking marker 4 based on the type of marker light of the blinking marker 4 detected by the first blinking detection unit 7 and the type of marker light in the receiving-side blinking marker 8 detected by the second blinking detection unit 72.

[0099] As a result, the second blinking detection unit 72 detects the periodic blinking of the marker light of the receiving-side blinking marker 8 based on the receiving-side reference signal Sg2. The blinking cycle adjustment unit 26A adjusts the blinking cycle of the marker light of the blinking marker 4 based on the marker light of the blinking marker 4 detected by the first blinking detection unit 7 and the marker light of the receiving-side blinking marker 8 detected by the second blinking detection unit 72. For example, if the type of marker light of the blinking marker 4 detected by the first blinking detection unit 7 differs from the type of marker light of the receiving-side blinking marker 8 detected by the second blinking detection unit 72, it can be determined that the video transmission delay time Td is longer than the blinking cycle of the marker light of the blinking marker 4. Therefore, by adjusting the blinking cycle of the marker light of the blinking marker 4 by the blinking cycle adjustment unit 26A, the video transmission delay time Td can be accurately determined.

[0100] (9) The video transmission delay time measuring system 1C according to the ninth aspect is the video transmission delay time measuring system 1C of (7), wherein the transmitting unit 2 further includes a transmitting side time information display device 200 that displays the shooting location time information Tp at the shooting location, the shooting device 3 captures the video including the shooting location time information Tp displayed on the transmitting side time information display device 200, the receiving unit 5 includes a time difference acquisition unit 300 that acquires the difference between the shooting location time information Tp displayed on the display device 6 and the remote location time information synchronized with the shooting location time information Tp acquired at the remote location, and the blinking period adjustment unit 26B adjusts the blinking period of the marker light in the blinking marker 4 based on the acquired difference.

[0101] As a result, when the photographing device 3 photographs an image including the photographing location time information Tp, which is displayed on the transmitting side time information display device 200, the time difference acquisition unit 300 can acquire the difference between the photographing location time information Tp displayed on the transmitting side time information display device 200 and the distant location time information acquired at the distant location. If the difference between the acquired photographing location time information Tp and the distant location time information is large, the blinking cycle adjustment unit 26B can adjust the blinking cycle of the marker light to accurately determine the image transmission delay time Td.

[0102] (10) The video transmission delay time measuring system 1D according to the tenth aspect is any one of the video transmission delay time measuring systems 1D of (1) to (9), in which the image capturing device 3 and the flashing marker 4 are capable of relative movement so as to return to their fixed positions in accordance with the flashing period of the flashing marker 4.

[0103] As a result, when the photographing device 3 and the blinking marker 4 are moved relatively to return to their home positions in accordance with the blinking cycle of the blinking marker 4, if the photographing device 3 and the blinking marker 4 are operating normally, the photographing device 3 positioned in each home position can photograph the blinking of the blinking marker 4. If at least one of the photographing device 3 and the blinking marker 4 is not operating normally, the photographing device 3 will not be able to properly photograph the blinking of the blinking marker 4. Therefore, it is easy to determine whether the photographing device 3 and the blinking marker 4 are operating normally.

[0104] (11) A video transmission delay time measuring method according to an eleventh aspect includes a step S11 of receiving a GPS signal at a shooting location, a step S12 of transmitting a transmitting side reference signal Sg1 synchronized with the received GPS signal, a step S13 of periodically blinking a marker light based on the transmitting side reference signal Sg1, a step S14 of capturing a video including a subject and the blinking marker 4 at the shooting location, a step S15 of transmitting data of the captured video, a step S21 of receiving data of the video at a remote location away from the shooting location, and a step S22 of transmitting data of the received video. the step S22 of displaying an image based on the detected GPS signal; the step S23 of detecting blinking of the marker light in the displayed image; the step S24 of receiving a GPS signal at the remote location; the step S25 of transmitting a receiving-side reference signal Sg2 synchronized with the GPS signal received at the remote location; and the step S26 of outputting information about an image transmission delay time Td from when the image is captured by the image capturing device 3 to when the image is displayed on the display device 6, based on the detected blinking signal Sgm indicating the blinking state of the marker light and the receiving-side reference signal Sg2.

[0105] This video transmission delay time measuring method can measure the video transmission delay time while actually shooting the video. [Explanation of symbols]

[0106] 1A~1D...Video transmission delay time measurement system 2...Transmitting unit 3...Photographing equipment 3a...Range 4...Blinking marker 4m, 4mB, 4mG, 4mR...marker light 5...Receiving unit 6...Display device 7...First flashing detection unit 8...Receiver blinking marker 8m, 8mB, 8mG, 8mR...marker light 20...Transmitting controller 21...Shooting control unit 22...Marker control unit 23...Transmitting GPS signal receiver 24...Transmitter reference signal generator 25...Data transmission unit 26A, 26B...Flash cycle adjustment section 31...Fixing member 50...Receiving controller 51...Data receiving unit 52...Display control unit 53...Receiver GPS signal receiver 54... Receiver reference signal generator 55...Delay time information output section 56A: Delay time abnormality judgment section 58...Fault diagnosis section 72...Second flashing detection unit 100…Network 200...Transmitter time information display device 300…Time difference acquisition unit 301...Camera Sg1: Transmitter reference signal Sg2: Receiver reference signal Sgm...flashing signal Sgr...flashing signal T...Photography subject Td: Video transmission delay time Tp...Shooting location and time information

Claims

1. A transmitting unit is disposed at a photographing location, and a receiving unit is disposed at a remote location away from the photographing location, The transmitting unit a transmitting-side GPS signal receiving unit that receives a GPS (Global Positioning System) signal at the photography location; a transmitter-side reference signal transmitter that transmits a transmitter-side reference signal synchronized with the GPS signal received by the transmitter-side GPS signal receiver; a blinking marker that periodically blinks a marker light based on the transmitting side reference signal; a photographing device that photographs an image including a photographing target and the blinking marker at the photographing location; a data transmission unit that transmits data of the video captured by the imaging device, The receiving unit: a data receiving unit that receives the video data; a display device that displays an image based on the received image data; a first blinking detection unit that detects blinking of the marker light in the image displayed on the display device; a receiving-side GPS signal receiving unit that receives a GPS signal at the remote location; a receiving-side reference signal transmitting unit that transmits a receiving-side reference signal synchronized with the GPS signal received by the receiving-side GPS signal receiving unit; a delay time information output unit that outputs information about a video transmission delay time from when the video is captured by the imaging device to when the video is displayed on the display device, based on a blinking signal that indicates a blinking state of the marker light detected by the first blink detection unit and the receiving-side reference signal. Video transmission delay time measurement system.

2. the transmitting-side reference signal and the receiving-side reference signal are pulse signals whose signal states change at predetermined time intervals, the blinking signal is a waveform signal that indicates switching of a signal state in response to lighting and extinguishing of the blinking marker; 2. The video transmission delay time measuring system according to claim 1.

3. The delay time information output unit An oscilloscope that displays the receiving-side reference signal and the blinking signal side by side.

3. The video transmission delay time measuring system according to claim 2.

4. The delay time information output unit and outputting information about the video transmission delay time based on the timing at which the signal state of the receiving-side reference signal changes and the timing at which the signal state of the blinking signal changes.

4. The video transmission delay time measuring system according to claim 2 or 3.

5. The delay time information output unit The video transmission delay time is calculated based on the timing at which the signal state of the receiving-side reference signal changes and the timing at which the signal state of the blinking signal changes, and the calculated value of the video transmission delay time is output.

5. The video transmission delay time measuring system according to claim 4.

6. The camera further includes a fixing member for fixing the flashing marker and the camera.

3. The video transmission delay time measuring system according to claim 1 or 2.

7. The transmitting unit The flashing marker further includes a flashing cycle adjustment unit that adjusts the flashing cycle of the marker light.

3. The video transmission delay time measuring system according to claim 1 or 2.

8. The receiving unit: a receiving-side blinking marker that periodically blinks a marker light based on the receiving-side reference signal; a second blinking detection unit that detects blinking of the marker light of the receiving side blinking marker, the blinking marker and the receiving-side blinking marker are each capable of blinking a plurality of types of the marker light in the same sequence, The blinking cycle adjustment unit adjusts the blinking cycle of the marker light of the blinking marker based on the type of the marker light of the blinking marker detected by the first blink detection unit and the type of the marker light of the receiving side blinking marker detected by the second blink detection unit.

8. The video transmission delay time measuring system according to claim 7.

9. the transmitting unit further includes a transmitting-side time information display device that displays the photographing location time information at the photographing location based on external time information distributed from an external time information output unit; the photographing device photographs the image including the photographing location and time information displayed on the transmitting side time information display device, The receiving unit: the photographing location and time information displayed on the display device; a time difference acquisition unit that acquires a difference between remote location time information based on external time information distributed from an external time information output unit and remote location time information acquired at the remote location, The blinking cycle adjustment unit adjusts the blinking cycle of the marker light of the blinking marker based on the acquired difference.

8. The video transmission delay time measuring system according to claim 7.

10. The photographing device and the blinking marker are movable relative to each other so as to return to their home positions in accordance with the blinking cycle of the blinking marker.

3. The video transmission delay time measuring system according to claim 1 or 2.

11. receiving a GPS signal at a photography location; transmitting a transmitter reference signal synchronized with the received GPS signal; a step of periodically blinking a marker light by a blinking marker based on the transmitting side reference signal; A step in which an image capturing device captures an image including a subject and the blinking marker at the image capturing location; transmitting data of the video captured by the imaging device; receiving the image data at a remote location away from the shooting location; a step of displaying an image based on the received image data by a display device; detecting blinking of the marker light in the displayed image; receiving a GPS signal at the remote location; transmitting a receiver reference signal synchronized with the GPS signal received at the remote location; and outputting information relating to a video transmission delay time from when the video is captured by the imaging device to when the video is displayed on the display device, based on a blinking signal indicating a blinking state of the detected marker light and the receiving-side reference signal. Video transmission delay time measurement method.

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