Imaging device and control method thereof

Abstract

To notify a user of an input of an incorrect synchronization signal.SOLUTION: An image capturing apparatus comprises: imaging means; output means which outputs a video acquired by the imaging means to an external device; synchronous control means which executes one of first synchronous control for outputting a video from the output means based on a first synchronization signal generated in the image capturing apparatus, and second synchronous control for outputting a video from the output means based on a second synchronization signal input from the outside; acquisition means which acquires frequency of the first synchronization signal and frequency of the second synchronization signal; determination means which determines whether the frequency of the first synchronization signal and the frequency of the second synchronization signal satisfy a predetermined relationship; and display control means which controls, when the determination means determines that the predetermined relationship is not satisfied, a display device to display a warning message indicating that the second synchronization signal is an incorrect synchronization signal.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a technique for controlling video output in an imaging device. [Background technology]

[0002] A Genlock function is known as a function that enables switching and outputting video from cameras without causing image distortion when switching between multiple camera images using a switcher, etc. Patent Document 1 discloses a technology that outputs a black image when the drive frequency of the imaging device does not match the frequency of an externally input synchronization signal after the Genlock function is enabled. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-142785 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-described conventional technology has a problem in that simply displaying a black image when a synchronization signal with a frequency incompatible with the drive frequency of the imaging device is input does not allow the user to know the reason for the black image being displayed. In other words, the user cannot recognize that a synchronization signal with an incompatible frequency has been input. Furthermore, there is a problem in that the operation of the imaging device becomes unstable if a synchronization signal with an incompatible frequency is input while the Genlock function is enabled.

[0005] The present invention has been made in view of the above problems, and aims to provide a technique for notifying a user of the input of an invalid synchronization signal. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, an imaging device according to the present invention has the following arrangement: An imaging means; an output means for outputting the image acquired by the imaging means to an external device; a synchronization control means for performing either a first synchronization control for outputting an image from the output means based on a first synchronization signal generated inside the imaging device, or a second synchronization control for outputting an image from the output means based on a second synchronization signal input from outside; receiving means for receiving an instruction to enable the second synchronization control; an acquisition means for acquiring the frequency of the first synchronization signal and the frequency of the second synchronization signal; a determining means for determining whether or not the frequency of the first synchronization signal and the frequency of the second synchronization signal satisfy a predetermined relationship; a display control means for controlling a display device to display a warning message indicating that the second synchronization signal is an invalid synchronization signal; Equipped with after the receiving means receives the enabling instruction, if the determining means determines that the predetermined relationship is satisfied, the synchronization control means enables the second synchronization control; after the synchronization control means has enabled the second synchronization control, if the determination means determines that the predetermined relationship is not satisfied, the synchronization control means stops enabling the second synchronization control, and the display control means displays the warning display on the display device; After the synchronization control means stops enabling the second synchronization control, if the determination means determines that the predetermined relationship is satisfied, the synchronization control means enables the second synchronization control again. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a technique for notifying a user of input of an invalid synchronization signal. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an overall configuration of an imaging system. [Figure 2A] FIG. 2 is a diagram illustrating the functional configuration of each device in the imaging system. [Figure 2B] FIG. 2 is a diagram illustrating a hardware configuration of a camera. [Figure 3] 5 is a flowchart showing the operation of the camera in the first embodiment. [Figure 4] FIG. 10 is a diagram showing an example of a display when an invalid synchronization signal is input. [Figure 5]10 is a flowchart showing the operation of a camera in a modified example. [Figure 6] 10 is a flowchart showing the operation of a camera in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0010] (First embodiment) As a first embodiment of an information processing device according to the present invention, a camera in an imaging system (an information processing device having an imaging unit) will be described below as an example.

[0011] <System configuration and device configuration> 1 is a diagram showing the overall configuration of an imaging system. The imaging system 10 is made up of two cameras 100 (camera 100-1 and camera 100-2), a controller 120, a display 130, and a synchronization signal output device 140. Here, it is assumed that the video output from the two cameras is switched by the controller 120 and displayed on the display 130.

[0012] A synchronization signal output from synchronization signal output device 140 is input to camera 100-1 and camera 100-2. The video output from camera 100-1 and camera 100-2 is synchronized in accordance with the input synchronization signal. Therefore, even when controller 120 switches the video output from camera 100-2 to camera 100-1, no interruption in the video occurs. Note that although a case where video outputs from two cameras are switched is described here, the same applies when video outputs from three or more cameras are switched.

[0013] 2A is a diagram showing the functional configuration of each device in the imaging system. As shown in FIG. 1, the imaging system includes a camera 100, a controller 120, a display 130, and a synchronization signal output device 140.

[0014] Camera 100, also known as a remote camera or network camera, captures images of a subject in a monitored area based on remote instructions. Camera 100 includes an imaging unit 101, an image processing unit 102, a system control unit 103, and a storage unit 104. Camera 100 also includes a pan driving unit 105, a tilt driving unit 106, a speed control unit 107, a mode control unit 108, a synchronization signal input unit 109, a Genlock control unit 110, a stabilization determination unit 111, and a communication unit 112.

[0015] The imaging unit 101 is composed of an optical system such as a lens and an imaging element such as a CMOS image sensor. The imaging unit 101 generates an analog image signal based on a subject image formed on the imaging element by the optical system. The analog image signal is converted into a digital image signal and output to the image processing unit 102.

[0016] The image processing unit 102 performs predetermined image processing and compression encoding processing on the digital image signal output from the imaging unit 101 to generate image data (or video data including multiple frame images), and outputs the image data to the system control unit 103. The predetermined image processing includes development processes such as debayer (demosaic) processing, white balance processing, and gradation conversion processing.

[0017] The system control unit 103 controls the overall operation of the camera 100. More specifically, the system control unit 103 outputs image data captured by the imaging unit 101 and acquired via the image processing unit 102 to the controller 120 via the communication unit 112. The system control unit 103 also receives control commands from the controller 120 via the communication unit 112, analyzes the received commands, and performs processing according to the commands. For example, when a control command for adjusting image quality is received for the image processing unit 102, the system control unit 103 analyzes the control command and performs image quality adjustment. When a control command for performing pan / tilt operation for the pan driving unit 105 and / or tilt driving unit 106 is received, the system control unit 103 analyzes the control command and controls the driving of the pan driving unit 105 and / or tilt driving unit 106. When a control command for enabling / disabling Genlock is received, the system control unit 103 instructs the Genlock control unit 110 to enable or disable Genlock.

[0018] The storage unit 104 stores control data within the camera 100 and captured image data (video data). When the camera 100 operates in playback mode, the image data stored in the storage unit 104 is output as video to the display unit 131. The storage unit 104 can also store image quality adjustment parameters, network setting values, or information about the imaging direction of the camera 100. The imaging direction information may be stored as, for example, the pan angle and tilt angle in the pan driver 105 and the tilt driver 106. The system control unit 103 can refer to the storage unit 104 and acquire previously set values ​​even when the camera 100 is restarted.

[0019] The pan driver 105, tilt driver 106, and speed controller 107 are direction control mechanisms for controlling the imaging direction of the camera 100. The pan driver 105 is composed of a mechanical drive system that performs panning in accordance with a control command from the system controller 103 and a motor that serves as its drive source. The system controller 103 controls the drive of the motor, causing the pan driver mechanism to drive in the pan direction. The tilt driver 106 is composed of a mechanical drive system that performs tilting in accordance with a control command from the system controller 103 and a motor that serves as its drive source. The system controller 103 controls the drive of the motor, causing the tilt driver mechanism to drive in the tilt direction. The speed controller 107 calculates the next drive speed to be instructed in accordance with the control command from the system controller 103, and instructs the pan driver 105 and the tilt driver 106 to drive at the calculated speeds, respectively. For example, the next drive speed to be instructed is calculated based on the current speed, target speed, acceleration value, or information from an acceleration / deceleration table.

[0020] The mode control unit 108 controls switching of the operation mode of the camera 100. Note that in FIG. 2, the mode control unit 108 is depicted as a functional unit separate from the system control unit 103, but it may be configured as part of the system control unit 103. Here, it is assumed that there are three operation modes of the camera 100 (normal imaging mode, standby mode, and playback mode). The normal imaging mode (first operation mode) is a mode in which video captured by the imaging unit 101 is output. The standby mode (second operation mode) is a mode in which video output is stopped and the camera is on standby. The playback mode (third operation mode) is a mode in which video stored in the storage unit 104 is output.

[0021] The mode control unit 108 determines which operating mode a switching instruction (transition instruction) to switch to (to) from the controller 120 has been input via the communication unit 112 and the system control unit 103, and sets the camera 100 to operate in the determined operating mode. The mode control unit 108 may indicate the operating mode using a predetermined setting value, for example. For example, "0" may indicate standby mode, "1" may indicate normal imaging mode, and "2" may indicate playback mode. In this case, the system control unit 103 determines the operating mode by referring to the setting value indicated by the mode control unit 108. The mode control unit 108 also controls switching of the drive frequency at which the camera 100 operates. For example, the mode control unit 108 controls switching between drive frequencies of 59.94 Hz and 29.97 Hz. The mode control unit 108 may indicate the operating mode of the current drive frequency using a predetermined setting value, for example. For example, "10" may indicate 59.94 Hz and "11" may indicate 29.97 Hz.

[0022] When it is determined that the system control unit 103 should operate in the normal imaging mode, it controls the imaging unit 101, image processing unit 102, system control unit 103, and communication unit 112 to output the captured video (image data) to the controller 120. The system control unit 103 also controls pan and tilt drive by the pan drive unit 105, tilt drive unit 106, and speed control unit 107. Furthermore, the image data generated by the image processing unit 102 is stored in the storage unit 104 via the system control unit 103.

[0023] On the other hand, when it is determined that the system control unit 103 should operate in standby mode, it controls the system to stop outputting captured video (image data) to the controller 120. The system control unit 103 also stops pan / tilt drive control by the pan drive unit 105, tilt drive unit 106, and speed control unit 107. The system control unit 103 may be configured to stop pan / tilt drive control after driving to a predetermined pan / tilt position.

[0024] Furthermore, when it is determined that the system control unit 103 should operate in the playback mode, the system control unit 103 controls the respective units, the storage unit 104, and the communication unit 112, so as to output the image data stored in the storage unit 104 to the controller 120. Note that when multiple pieces of video data are stored in the storage unit 104, the video data specified by the user is output via the controller 120.

[0025] The system control unit 103 also compares the frequency of the synchronization signal (second synchronization signal) input to the synchronization signal input unit 109 with the frequency of the synchronization signal (first synchronization signal) generated by the Genlock control unit 110 to determine whether an invalid synchronization signal has been input. That is, the first synchronization signal is a synchronization signal generated inside the camera. For example, the system control unit 103 determines whether the drive frequency of the image capture unit 101, which operates according to the synchronization signal specified by the mode control unit 108 and generated by the Genlock control unit 110, matches the frequency of the synchronization signal input from the synchronization signal input unit 109. The frequency of the synchronization signal generated by the Genlock control unit 110 may be information about the frame rate of the image capture unit 101 in normal imaging mode, or information about the frame rate at which video stored in the storage unit 104 is output in playback mode. If they match, the system control unit 103 determines that a valid synchronization signal has been input. On the other hand, if they do not match, the system control unit 103 determines that an invalid synchronization signal has been input. Furthermore, if it is determined that an invalid synchronization signal has been input, the image data stored in the storage unit 104 is output to the controller 120 via the processing units of the system control unit 103 and the communication unit 112, as image data indicating that an invalid synchronization signal has been input. At this time, the image data prompting the input of a synchronization signal of a normal frequency is also output to the controller 120.

[0026] The synchronization signal input unit 109 inputs the synchronization signal output from the synchronization signal output device 140 to the camera 100. The Genlock control unit 110 synchronizes the first synchronization signal generated by the Genlock control unit 110 with the second synchronization signal input from the synchronization signal input unit 109, thereby performing synchronization control of the system control unit 103 and the entire camera 100. As a result, in the normal imaging mode, video can be output to the controller 120 in synchronization with the second synchronization signal.

[0027] The Genlock control unit 110 also controls switching between enabling and disabling Genlock. Enabling Genlock means that, while a second synchronization signal is being input from the synchronization signal input unit 109, synchronization with the first synchronization signal generated by the Genlock control unit 110 begins in response to a Genlock enable instruction from the controller 120. Disabling Genlock means that synchronization between the second synchronization signal and the first synchronization signal generated by the Genlock control unit 110 is stopped in response to a Genlock disable instruction from the controller 120. When Genlock is disabled, the camera 100 controls its operation solely using the first synchronization signal generated by the Genlock control unit 110. Note that Genlock technology is well known, and therefore a detailed description thereof will be omitted. The Genlock control unit 110 also acquires the frequency of the second synchronization signal input from the synchronization signal input unit 109 (e.g., the frequency of the V synchronization signal).

[0028] The stabilization determination unit 111 determines whether the second synchronization signal and the first synchronization signal are stably synchronized when Genlock is enabled. Hereinafter, stably synchronizing the two synchronization signals is referred to as "Genlock being stable." For example, the stabilization determination unit 111 obtains the difference between the H / V synchronization signal (first synchronization signal) generated by the Genlock control unit 110 and the H / V synchronization signal (second synchronization signal) input from the synchronization signal input unit 109. If the difference remains within ± a predetermined number of clocks for a predetermined period of time or more, it determines that Genlock is stable. If not, it determines that Genlock is unstable.

[0029] Furthermore, when the Genlock control unit 110 enables Genlock and starts synchronization, it takes several seconds for the first synchronization signal to stably synchronize with the second synchronization signal input from the synchronization signal input unit 109. As a result, synchronization becomes unstable for a predetermined time (e.g., 7 seconds) after Genlock starts. Therefore, as an alternative determination method, whether synchronization is stable may be determined based on whether a predetermined time (e.g., 7 seconds) has elapsed since the Genlock control unit 110 enabled Genlock and started synchronization. Note that while Genlock is stabilizing, video distortion may occur, and video processing may be stopped for synchronization processing.

[0030] The communication unit 112 performs processing for network communication via a LAN. For example, the communication unit 112 transmits video data output from the system control unit 103 to the controller 120. The communication unit 112 also receives control commands from the controller 120 and passes them to the system control unit 103.

[0031] The controller 120 operates as a switcher (a switching device or a display control device) that switches the video to be displayed on the display 130. The controller 120 includes an input unit 121, a system control unit 122, and a communication unit 123.

[0032] The input unit 121 is configured with buttons, a joystick, etc., and accepts various operations from the user. These operations include, for example, an operation to switch the camera 100 that outputs video, an operation to switch the operation mode of the camera 100, an operation to enable / disable Genlock, etc. The system control unit 122 transmits control commands to the camera 100 via the communication unit 123 in response to the operation accepted from the user.

[0033] The communication unit 123 processes network communications via a LAN. For example, it receives video data output from the camera 100 and transfers it to the display 130. It also receives control commands from the system control unit 122 and transmits them to the camera 100.

[0034] Display 130 includes display unit 131. More specifically, display 130 receives video data output from camera 100 via controller 120 and displays the data on display unit 131. Display unit 131 is a display device such as a liquid crystal display.

[0035] The synchronization signal output device 140 includes a synchronization signal output unit 141. The synchronization signal output unit 141 outputs a synchronization signal (corresponding to the second synchronization signal described above) that serves as a reference signal for synchronously operating a plurality of cameras 100. In the first embodiment, it is assumed that a synchronization signal from the synchronization signal output device 140 is input to the synchronization signal input units 109 of each of the two cameras 100.

[0036] 2B is a diagram showing the hardware configuration of the camera. The CPU 201 is a device that performs overall control of the camera 100 and performs calculations, processing, and management of data. For example, by executing various programs, the CPU 201 can function as a system control unit 103, a speed control unit 107, a mode control unit 108, a Genlock control unit 110, etc. The CPU 201 may also function as an image processing unit 102 that compresses and encodes digital image signals output from the camera unit 206 to generate image data. These functional units may also be realized by dedicated processors (such as ASICs).

[0037] The RAM 202 is a volatile memory and is used as a temporary storage area such as the main memory or work area of ​​the CPU 201. The ROM 203 is a non-volatile memory in which various programs executed by the CPU 201, various parameters, etc. are stored in predetermined areas. For example, the CPU 201 controls each unit of the camera 100 by using the RAM 202 as a work memory and executing various programs stored in the ROM 203. Note that the programs for operating the CPU 201 do not necessarily have to be stored in the ROM 203, and may also be stored in the storage device 204.

[0038] The storage device 204 is configured with, for example, an SD card, a HDD, or a flash memory, and can function as the storage unit 104. The storage device 204 stores application programs, an OS, a control program, image data, and other data. The storage device 204 can read and write data under the control of the CPU 201. The storage device 204 may be used in place of the RAM 202 or the ROM 203.

[0039] The communication device 205 is a communication interface for communicating with the controller 120 under the control of the CPU 201 and can function as the communication unit 112. The communication device 205 can include a wireless communication module for wireless connection communication. In this case, it can include well-known circuitry including an antenna system, an RF transceiver, one or more amplifiers, a tuner, one or more oscillators, a digital signal processor, a CODEC chipset, a subscriber identity module card, memory, etc. The communication device 205 can also include a wired communication module for wired connection communication. The wired communication module enables wired connection communication with other devices via one or more physical ports. The physical ports can use Ethernet, USB, IEEE 1394, etc. The communication device 205 can also include various software components for processing data and can be configured as a substitute for the above-mentioned units.

[0040] The camera unit 206 can function as the imaging unit 101, pan driving unit 105, and tilt driving unit 106, and captures an image of a monitored area, which is real space, to generate a subject image. The camera unit 206 converts an analog image signal obtained using an imaging element into a digital image signal by A / D conversion and outputs the digital image signal to the CPU 201. In addition to still images, the camera unit 206 can, for example, capture a predetermined number of image frames (e.g., 30 frames) per second to capture 30 fps moving images (live video) of the monitored area. The operation unit 207 is composed of, for example, buttons, a cross key, a touch panel, etc., and accepts operation inputs from the user.

[0041] 2B illustrates the hardware configuration of camera 100, but the hardware configuration of controller 120 may also be similar to that illustrated in FIG. 2B. In this case, camera unit 206 is excluded from the configuration. Operation unit 207 functions as input unit 121 and may further include a keyboard and a mouse.

[0042] <Device Operation> FIG. 3 is a flowchart showing the operation of the camera 100 in the first embodiment. The processing corresponding to the flowchart in FIG. 3 is realized by the CPU 201 executing a predetermined program. Here, it is assumed that the camera 100, controller 120, display 130, and synchronization signal output device 140 have already been started, and that the controller 120 is ready to accept user input operations. This flowchart may be configured to start in response to a user instruction, or may be configured to start automatically by the camera 100. Furthermore, it is assumed that before executing the processing of this flowchart, the system control unit 103 controls each block of the camera 100 and starts operation in normal imaging mode.

[0043] In S301, the Genlock control unit 110 determines whether or not an instruction to enable Genlock has been received from the controller 120. If it is determined that an instruction to enable Genlock has been received, the process proceeds to S302. If it is not determined that an instruction to enable Genlock has been received, the process continues with S301.

[0044] In S302, the synchronization signal input unit 109 determines whether or not a synchronization signal (second synchronization signal) has been input from the synchronization signal output device 140. If it is determined that a synchronization signal has been input, the process proceeds to S303. On the other hand, if it is determined that a synchronization signal has not been input, the process of S302 continues.

[0045] In S303, the Genlock control unit 110 starts enabling Genlock. In S304, the system control unit 103 acquires the drive frequency at which the camera 100 operates. In S305, the Genlock control unit 110 acquires the frequency of the synchronization signal input from the synchronization signal input unit 109.

[0046] In S306, the system control unit 103 determines whether an invalid synchronization signal has been input from the synchronization signal input unit 109. For example, it determines whether the drive frequency at which the camera 100 operates matches the frequency of the synchronization signal input from the synchronization signal input unit 109. If they match, it is determined that a valid synchronization signal has been input, and if they do not match, it is determined that an invalid synchronization signal has been input.

[0047] For example, if the drive frequency at which camera 100 operates is 59.94 Hz and the frequency of the synchronization signal input from synchronization signal input unit 109 is 50.00 Hz, it is determined that an invalid synchronization signal has been input because the frequencies do not match. Furthermore, if the drive frequency at which camera 100 operates and the frequency of the synchronization signal input from synchronization signal input unit 109 satisfy a predetermined relationship (e.g., one is an integer multiple of the other), it is determined that a valid synchronization signal has been input. On the other hand, if the predetermined relationship is not satisfied, it is also possible to determine that an invalid synchronization signal has been input. For example, if the drive frequency at which camera 100 operates is 59.94 Hz and the frequency of the synchronization signal input from synchronization signal input unit 109 is 29.97 Hz, it is determined that a valid synchronization signal has been input because of the multiple relationship. If it is determined that an invalid synchronization signal has been input, the process proceeds to S307. If it is determined that an invalid synchronization signal has not been input, the process proceeds to S309.

[0048] In S307, the system control unit 103 outputs the "image data indicating that an invalid synchronization signal has been input" stored in the storage unit 104 to the controller 120 via the communication unit 112. At the same time, the system control unit 103 outputs the "image data indicating the frequency of a valid synchronization signal" to the controller 120. Then, the controller 120 displays warning information on the display unit 131 of the display 130 based on the image data.

[0049] 4 shows an example of a display that appears when an invalid synchronization signal is input. Here, a warning message is displayed indicating that an invalid synchronization signal has been input, along with a frequency display indicating the frequency of the correct synchronization signal (which should be input) (e.g., 59.94 Hz). The frequency of the correct synchronization signal is a frequency that can be used as a secondary synchronization signal.

[0050] In S308, the Genlock control unit 110 stops Genlock activation. S309 is the same process as S304, so its description will be omitted. S310 is the same process as S305, so its description will be omitted. S311 is the same process as S306, so its description will be omitted. If it is determined in S311 that an invalid synchronization signal has been input, the process proceeds to S307. If it is determined that an invalid synchronization signal has not been input, the process proceeds to S312.

[0051] In S312, the Genlock control unit 110 determines whether or not Genlock activation has been completed. If Genlock activation has been completed, the process of this flowchart ends. If Genlock activation has not been completed, the process proceeds to S309.

[0052] As described above, according to the first embodiment, when an invalid synchronization signal is input to a camera, which is an image capture device, the user can be notified that an invalid synchronization signal has been input. Furthermore, the user can recognize information about a valid synchronization signal for Genlock. Furthermore, by stopping Genlock when an invalid synchronization signal is input, it is possible to prevent the operation of the camera 100 from becoming unstable.

[0053] Furthermore, even if an invalid synchronization signal is input during Genlock activation, the user is notified that an invalid synchronization signal has been input, allowing the user to recognize this. Furthermore, by stopping (canceling) Genlock activation (i.e., transitioning to synchronization control based on the first synchronization signal), it is possible to prevent the operation of camera 100 from becoming unstable.

[0054] (Variation) As a modified example, a mode in which the order of processing in the first embodiment is changed will be described. Note that the system configuration and device configuration are the same as those in the first embodiment (FIGS. 1 and 2A), and therefore description thereof will be omitted.

[0055] <Device Operation> Fig. 5 is a flowchart showing the operation of the camera 100 in the second embodiment. The processing corresponding to the flowchart in Fig. 5 is realized by the CPU 201 executing a predetermined program. Note that the processing from S301 to S312 is the same as the processing from S301 to S312 in the first embodiment (Fig. 3), and therefore a description thereof will be omitted.

[0056] However, in this modification, the process of starting Genlock activation (S303) is performed after it is confirmed that an invalid synchronization signal has not been input (No in S306). In other words, Genlock activation starts after a valid synchronization signal has been input.

[0057] This prevents the Genlock from being enabled due to the input of an invalid synchronization signal, and prevents the system of the camera 100 from becoming unstable. Furthermore, when an invalid synchronization signal is input, the user can be notified that an invalid synchronization signal has been input. Furthermore, at that time, the user can recognize information about the valid synchronization signal.

[0058] Furthermore, even if an invalid synchronization signal is input during Genlock activation, the user is notified that an invalid synchronization signal has been input, allowing the user to recognize this. Furthermore, by stopping (canceling) Genlock activation, it is possible to prevent the operation of the camera 100 from becoming unstable.

[0059] (Second embodiment) In the third embodiment, the operation of another embodiment will be described. Note that the system configuration and device configuration are the same as those of the first embodiment (FIGS. 1 and 2A), and therefore the description thereof will be omitted.

[0060] <Device Operation> Fig. 6 is a flowchart showing the operation of the camera 100 in the second embodiment. The processing corresponding to the flowchart in Fig. 6 is executed after S312 (Genlock activation is completed) in the flowcharts of the first embodiment (Fig. 3) and the modified example (Fig. 5). The processing in Fig. 6 is realized by the CPU 201 executing a predetermined program. Note that the processing in S307 to S312 shown in Fig. 6 is similar to the processing in S307 to S312 in the first embodiment (Fig. 3), and therefore a description thereof will be omitted.

[0061] In S601, the system control unit 103 determines whether the camera 100 is in standby mode. If it is determined that the camera 100 is in standby mode, the process proceeds to S307. On the other hand, if it is determined that the camera 100 is not in standby mode (i.e., in normal imaging mode or playback mode), the process proceeds to S308.

[0062] That is, if an invalid synchronization signal is input after Genlock activation is complete, a decision is made as to whether or not to notify the user that an invalid synchronization signal has been input, depending on the operating mode at that time. Here, if the camera is in standby mode, a message is displayed on the display indicating that an invalid synchronization signal has been input. Furthermore, by stopping Genlock activation when an invalid synchronization signal is input, it is possible to prevent the camera 100 system from becoming unstable.

[0063] On the other hand, if an invalid synchronization signal is input after Genlock activation is complete, the display will not display a message indicating that an invalid synchronization signal has been input unless the camera is in standby mode. That is, in normal imaging mode or playback mode, priority is given to displaying the image on the display so as not to interfere with the user's viewing of the image. However, even in normal imaging mode or playback mode, if an invalid synchronization signal is input, Genlock activation will be stopped. This prevents the operation of the camera 100 from becoming unstable.

[0064] As described above, according to the second embodiment, when an invalid synchronization signal is input to a camera, which is an imaging device, a message indicating that an invalid synchronization signal has been input is displayed on the display only if the camera is in standby mode. This prevents the user from being prevented from viewing the video, and allows for operation that takes user convenience into consideration.

[0065] (Other Examples) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0066] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0067] 10 imaging system; 100 camera; 120 controller; 130 display; 140 synchronization signal output device

Claims

1. An imaging device, An imaging means; an output means for outputting the image acquired by the imaging means to an external device; a synchronization control means for performing either a first synchronization control for outputting an image from the output means based on a first synchronization signal generated inside the imaging device, or a second synchronization control for outputting an image from the output means based on a second synchronization signal input from outside; a receiving means for receiving an instruction to enable the second synchronization control; an acquisition means for acquiring the frequency of the first synchronization signal and the frequency of the second synchronization signal; a determining means for determining whether or not the frequency of the first synchronization signal and the frequency of the second synchronization signal satisfy a predetermined relationship; a display control means for controlling a display device to display a warning message indicating that the second synchronization signal is an invalid synchronization signal; Equipped with after the receiving means receives the enabling instruction, if the determining means determines that the predetermined relationship is satisfied, the synchronization control means enables the second synchronization control; after the synchronization control means has enabled the second synchronization control, if the determination means determines that the predetermined relationship is not satisfied, the synchronization control means stops enabling the second synchronization control, and the display control means displays the warning display on the display device; After the synchronization control means stops enabling the second synchronization control, if the determination means determines that the predetermined relationship is satisfied, the synchronization control means re-enables the second synchronization control. An imaging device characterized by:

2. An imaging device, An imaging means; an output means for outputting the image acquired by the imaging means to an external device; a switching means for switching an operation mode of the imaging device between a first mode in which the image captured by the imaging means is output from the output means and a second mode in which the image captured by the imaging means is not output from the output means; a synchronization control means for performing either a first synchronization control for outputting an image from the output means based on a first synchronization signal generated inside the imaging device, or a second synchronization control for outputting an image from the output means based on a second synchronization signal input from outside; an acquisition means for acquiring the frequency of the first synchronization signal and the frequency of the second synchronization signal; a determining means for determining whether or not the frequency of the first synchronization signal and the frequency of the second synchronization signal satisfy a predetermined relationship; a display control means for controlling a display device to display a warning message indicating that the second synchronization signal is an invalid synchronization signal when the determination means determines that the predetermined relationship is not satisfied; and Equipped with The display control means controls to suppress display of the warning message when the determination means determines that the predetermined relationship is not satisfied while the imaging device is operating in the first mode. An imaging device characterized by:

3. When the determining means determines that the predetermined relationship is not satisfied, the display control means controls the display device to display, together with the warning display, a frequency display relating to a frequency that can be used as the second synchronization signal.

3. The imaging device according to claim 1, wherein the imaging device is a lens.

4. The frequency that can be used as the second synchronization signal is a frequency that satisfies the predetermined relationship with the frequency of the first synchronization signal.

4. The imaging device according to claim 3.

5. The predetermined relationship is a relationship in which one of the frequency of the first synchronization signal and the frequency of the second synchronization signal is an integer multiple of the other.

5. The imaging device according to claim 1, wherein the imaging device comprises: a first lens;

6. A control method for an imaging device, comprising: The imaging device is An imaging means; an output means for outputting the image acquired by the imaging means to an external device; a synchronization control means for performing either a first synchronization control for outputting an image from the output means based on a first synchronization signal generated inside the imaging device, or a second synchronization control for outputting an image from the output means based on a second synchronization signal input from outside; Equipped with The control method includes: after receiving an instruction to enable the second synchronization control, if the frequency of the first synchronization signal and the frequency of the second synchronization signal satisfy a predetermined relationship, enabling the second synchronization control; a step of controlling a display device to stop enabling the second synchronization control and display a warning message indicating that the second synchronization signal is an invalid synchronization signal when the frequency of the first synchronization signal and the frequency of the second synchronization signal do not satisfy the predetermined relationship after enabling the second synchronization control; After stopping the enablement of the second synchronization control, if the frequency of the first synchronization signal and the frequency of the second synchronization signal satisfy the predetermined relationship, re-enabling the second synchronization control; A control method comprising:

7. A control method for an imaging device, comprising: The imaging device is An imaging means; an output means for outputting the image acquired by the imaging means to an external device; a synchronization control means for performing either a first synchronization control for outputting an image from the output means based on a first synchronization signal generated inside the imaging device, or a second synchronization control for outputting an image from the output means based on a second synchronization signal input from outside; Equipped with The control method includes: an acquisition step of acquiring a frequency of the first synchronization signal and a frequency of the second synchronization signal; a determining step of determining whether or not the frequency of the first synchronization signal and the frequency of the second synchronization signal satisfy a predetermined relationship; a first display control step of controlling a display device to display a warning message indicating that the second synchronization signal is an invalid synchronization signal when the determination step determines that the predetermined relationship is not satisfied while the imaging device is operating in a second mode in which the image captured by the imaging means is not output from the output means; and a second display control step of controlling the image capturing device to suppress display of the warning message when it is determined in the determination step that the predetermined relationship is not satisfied while the image capturing device is operating in a first mode in which the image captured by the image capturing means is output from the output means; and A control method comprising:

8. A program for causing a computer to execute the control method according to claim 6 or 7.

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