JP7150538B2 - IMAGING DEVICE, IMAGING DEVICE CONTROL METHOD AND PROGRAM - Google Patents

Description

The present invention relates to an imaging device that detects a light shielding state, a control method for the imaging device, and a program.

2. Description of the Related Art Barriers are used in interchangeable-lens cameras to prevent dust from entering the camera body. As a related technology, a lens interchangeable camera is proposed in Japanese Patent Application Laid-Open No. 2002-200012. The lens-interchangeable camera disclosed in Patent Document 1 is configured to cover the insertion opening of the lens barrel unit with a barrier built into the camera body.

JP-A-8-171130

By providing a light-shielding curtain on a camera (imaging device), it is possible to prevent foreign matter such as dust from entering the camera body, and to protect the image sensor in the camera from sunlight. . The operation of the light shielding curtain is controlled so as to be in an open state in which incident light is not blocked during photographing. Here, for example, in the case of an image pickup apparatus such as a network camera that takes pictures for a long time, the light shielding curtain is closed (a state in which incident light is blocked) due to factors such as disturbances, even though the picture is being taken. Sometimes. In this respect, the detection mechanism for detecting the light shielding state periodically detects the phase of the light shielding curtain, so that the light shielding curtain can be prevented from being closed while the imaging device is shooting. However, in this case, since the detection mechanism periodically detects the light blocking state, it is necessary to periodically supply power to the detection mechanism, which increases power consumption.

SUMMARY OF THE INVENTION An object of the present invention is to provide an imaging device, a control method for the imaging device, and a program capable of reducing the power consumed to detect the light blocking state.

In order to achieve the above object, an image pickup apparatus of the present invention includes detection means for detecting light shielding means for blocking light incident on an image sensor, and luminance information of light incident on the image sensor periodically. and a control means for controlling a cycle of detecting the light shielding means based on the luminance information acquired in the above.

According to the present invention, it is possible to reduce the power consumed for detecting the light blocking state.

1 is a diagram showing a configuration example of a network camera; FIG. It is a figure which shows the structural example of a light-shielding part. It is a front view of an optical filter unit. 4 is a perspective view showing the positional relationship among the lens unit, the optical filter unit, the light shielding section, and the imaging element; FIG. 4 is a flow chart showing the flow of processing according to the first embodiment; 9 is a flow chart showing the flow of processing according to the second embodiment;

Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. However, the configurations described in each embodiment below are merely examples, and the scope of the present invention is not limited by the configurations described in each embodiment.

<First embodiment>
A first embodiment will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a network camera 100. As shown in FIG. In each embodiment, the imaging device is described as being the network camera 100, but the imaging device applied in each embodiment is not limited to the network camera. The network camera 100 is used, for example, for long-term continuous shooting. The continuous shooting time of network camera 100 may be any time. The network camera 100 has an imaging section 110 , a network control section 120 and a power control section 150 . A lens unit 111 is a unit that is detachable from the network camera 100 . A network device 130 and an external power supply 140 are connected to the network camera 100 . A lens unit 111 is a unit including a lens group such as a zoom lens, a focus lens, an anti-vibration lens, and aperture blades. The lens unit 111 is equipped with a CPU, and the CPU of the lens unit 111 controls each block of the lens group according to instructions from the imaging unit 110 . Specifically, the CPU of the lens unit 111 performs zoom lens control, focus lens control, anti-vibration lens control, and aperture blade control.

The imaging unit 110 transfers the captured image data to the network control unit 120 , and the network control unit 120 transmits the image data transferred from the imaging unit 110 to the network device 130 . The imaging section 110 has an imaging device 112 , a signal processing circuit 113 , an imaging control circuit 114 , a memory transfer circuit 115 , a first system control section 118 and an optical filter unit 117 .

The imaging device 112 converts light (light from an object to be imaged) imaged through the lens unit 111 into electric charge and generates an imaging signal. The signal processing circuit 113 receives the imaging signal generated by the imaging element 112 and digitizes the imaging signal to generate image data. The imaging control circuit 114 controls the imaging device 112 in the same period as the image data output period. When the image data accumulation time is longer than the image data output cycle, the imaging control circuit 114 performs signal processing so that the frame memory of the signal processing circuit 113 holds the image data during the period when the imaging signal cannot be output from the imaging device 112 . Controls circuit 113 . The memory transfer circuit 115 transfers the image data digitized by the signal processing circuit 113 to the memory 122 in the network control section 120 . The first system control unit 118 controls the entire imaging unit 110 . The first system control unit 118 corresponds to control means. The first system control unit 118 includes, for example, a CPU, RAM and ROM. The functions of the first system control unit 118 may be implemented by having the program stored in the ROM developed in the RAM and the CPU executing the program developed in the RAM. Some or all of the functions of the first system control unit 118 may be provided by, for example, the network device 130 instead of the network camera 100 .

As shown in FIG. 2, the light shielding unit 116 includes two light shielding curtains 501, a galvanometer 505 (motor drive unit), a phase detection circuit 504 for the light shielding curtains, and the like. The driving force of the galvanometer 505 controls the opening and closing of the light shielding curtain 501 , thereby controlling the incidence of light on the imaging element 112 . FIG. 3 is a front view of the optical filter unit 117. FIG. The optical filter unit 117 includes an infrared cut filter 601 , a transmission glass 600 and a driving motor 603 . Light entering through the lens unit 111 passes through either the infrared cut filter 601 or the transmission glass 600 and is received by the imaging element 112 . In other words, either the infrared cut filter 601 or the transmission glass 600 is inserted on the optical path of light incident through the lens unit 111 . The light that has passed through the infrared cut filter 601 becomes light from which the infrared light component has been cut, and is converted into an electrical signal by the imaging device 112 . The light that has passed through the transmission glass 600 is converted into an electric signal by the imaging element 112 without cutting the infrared light component.

Network control unit 120 has second system control unit 121 , memory 122 and network I/F 123 . The second system control section 121 controls the network control section 120 . The second system control unit 121 transmits the image data transferred from the memory transfer circuit 115 to the memory 122 to the external network device 130 through the network I/F 123 . Network device 130 receives image data from network camera 100 . The network device 130 may be a host terminal (predetermined information processing device) or the like. Network appliance 130 can also power network camera 100 through a network cable. The second system control unit 121 includes, for example, a CPU, RAM and ROM. The functions of the second system control unit 121 may be realized by having the program stored in the ROM developed in the RAM and the CPU executing the program developed in the RAM. The second system control unit 121 may have the functions of the first system control unit 118 , and the first system control unit 118 may have the functions of the second system control unit 121 . In the following description, it is assumed that the first system control unit 118 performs the control of the embodiment.

The power control unit 150 is a circuit including a DC-DC converter, a switch circuit for switching blocks to be energized, and the like. The power control unit 150 performs power control for the imaging unit 110 and the network control unit 120 . The power supply control unit 150 receives power supply from the external power supply 140 via a power cable, and controls power supply to the imaging unit 110 and the network control unit 120 . The power control unit 150 may receive power from the network device 130 via a network cable. The external power supply 140 is a commercial power supply, a DC power supply, or the like. As described above, the network camera 100 can also be powered via a network cable. The power source in this case is PoE (Power over Ethernet), PoE+, or the like.

FIG. 2 is a front view showing an example of the light shielding section 116 (light shielding unit). In the example of FIG. 2, the light blocking section 116 has two light blocking curtains 501, an arm 502, a stopper member 503, a phase detection circuit 504, a galvanometer 505, an arm 506 and a drive spring 508. The light shielding unit 116 controls incident light to the imaging device 112 by opening and closing two light shielding curtains 501 . The light shielding curtain 501 corresponds to light shielding means. The number of light shielding curtains 501 may be one, or three or more. The stopper member 503 is a member for restricting the vertical movement of the light shielding curtain 501 within a certain range. A phase detection circuit 504 is a circuit for detecting the phase of the light shielding curtain 501, and is, for example, a photointerrupter circuit. The phase detection circuit 504 corresponds to detection means. The phase detection circuit 504 outputs a Hi signal when the light shielding curtain 501 is in the open phase, and outputs a Low signal when the light shielding curtain 501 is in the closed phase.

The galvanometer 505 rotates by receiving a voltage input, and as the galvanometer 505 rotates, the arm 506 joined to the galvanometer 505 also rotates. The arm 506 is joined to each of the two light shielding curtains 501 . When the arm 506 rotates counterclockwise, the two light shielding curtains 501 move vertically. The first system control unit 118 controls the magnitude of the voltage input to the galvanometer 505 by changing the duty ratio, for example. If the input voltage to galvanometer 505 is greater than a predetermined voltage, galvanometer 505 rotates counterclockwise. If the input voltage to galvanometer 505 is below a predetermined voltage, galvanometer 505 rotates clockwise. The direction of rotation of galvanometer 505 is not limited to the direction described above. By applying a predetermined voltage to the galvanometer 505, the first system control unit 118 can also hold the two light shielding curtains 501 at predetermined positions.

FIG. 2A shows an example in which the light shielding curtain 501 is closed. In this case, the imaging device 112 receives light from the lens unit 111 . FIG. 2B shows an example in which the light shielding curtain 501 is open. In this case, the image sensor 112 does not receive light from the lens unit 111 . The drive spring 508 is joined by the light shielding curtain 501 and the arm 502, and the drive spring 508 is charged in the open state. From this state, when the input voltage to the galvanometer 505 is turned off, the light shielding curtain 501 moves in the closing direction. In other words, the input voltage to the galvanometer 505 is turned off when the power source is disconnected, and the action of the charged drive spring 508 closes the light shielding curtain 501 .

As described above, the optical filter unit 117 in FIG. 3 has two windows, the infrared cut filter 601 and the transmission glass 600 . When the driving motor 603 is rotated by the driving force, the optical filter unit 117 moves left and right. A filter detection circuit 602 is a circuit that detects the position of the optical filter unit 117, and is, for example, a photointerrupter circuit. The filter detection circuit 602 functions as an encoder and detects the position of the optical filter unit 117 by measuring the pulse count. The optical filter unit 117 has either an infrared cut filter 601 or a transmissive glass 600 placed on the optical path of light incident from the lens unit 111, thereby filtering out infrared wavelength components of light received by the imaging element 112. controlling. FIG. 4 is a perspective view showing the positional relationship among the lens unit 111, the optical filter unit 117, the light blocking section 116, and the imaging element 112. FIG. The light that has passed through the lens unit 111 passes through the optical filter unit 117 and is controlled by the light blocking section 116 as to whether or not it enters the image sensor 112 .

Next, the flow of processing according to the first embodiment will be described with reference to the flowchart of FIG. In the first embodiment, after the network camera 100 is activated, the light shielding unit 116 opens the light shielding curtain 501, and the first system control unit 118 detects the phase of the light shielding curtain 501 according to the brightness of the shooting scene. cycle. The phase of the light shielding curtain 501 indicates whether the light shielding curtain 501 is open or closed. For example, when an activation instruction is input to the network camera 100, the power control unit 150 is activated and the power of the network camera 100 is turned on (S101). At this time, for example, the power control unit 150 communicates with an IC (integrated circuit) that performs DCDC control, and outputs a predetermined voltage to the imaging unit 110 and the network control unit 120 . The power control unit 150 requests the network control unit 120 to start booting. Thereby, the network control unit 120 performs initialization processing of the second system control unit 121, the memory 122, the communication I/F 123, and the like.

The first system control unit 118 determines whether the lens unit 111 is attached, and when it is determined that the lens unit 111 is attached, opens the light shielding curtain 501 and controls the light shielding unit 116 so as to be in the open state. (S102). Specifically, the first system control unit 118 performs control to input to the galvanometer 505 a predetermined first voltage required for opening the light shielding curtain 501 . The first system control unit 118 starts supplying power to the phase detection circuit 504 for detecting the phase of the light shielding curtain 501, and turns on the power (S103). The first system control unit 118 determines whether or not the light shielding curtain 501 is open by detecting the phase of the light shielding curtain 501 (S104). Specifically, the first system control unit 118 acquires the voltage value output from the phase detection circuit 504 and determines whether the voltage value is equal to or greater than a predetermined value. For example, when the acquired voltage value is equal to or greater than a predetermined value, the first system control unit 118 determines that the light shielding curtain 501 is in the open state as the detection result. On the other hand, when the acquired voltage value is smaller than the predetermined value, the first system control unit 118 determines that the light shielding curtain 501 is in the closed state as the detection result.

If the determination in S104 is YES, the first system control unit 118 stops power supply to the phase detection circuit 504 for detecting the phase of the light shielding curtain 501 (S105). The first system control unit 118 starts a holding energization process for keeping the light shielding curtain 501 open (S106). Specifically, first system control unit 118 switches the voltage input to galvanometer 505 to a second voltage that is lower than the first voltage. Switching between the first voltage and the second voltage may be realized by changing the duty ratio. The first system control unit 118 acquires the photometric value of the light incident on the image sensor 112 (S107). The imaging element 112 converts incident light into an electrical signal and converts the electrical signal into an electrical signal. Image data is generated based on the converted electrical signal. The converted electrical signal represents luminance information. In the embodiment, the first system control unit 118 acquires luminance information based on the electrical signal converted by the imaging element 112 as a photometric value. Therefore, the first system control unit 118 acquires the brightness information of the image data as a photometric value.

The first system control unit 118 determines whether the photometric value (luminance) is smaller than the first threshold (predetermined luminance) (S108). The first system control unit 118 makes the determination in S108 using the latest photometric value obtained in step S107. If the photometric value is smaller than the first threshold, the first system control unit 118 determines that the ambient light is dark. If the photometric value (luminance) is equal to or higher than the first threshold (or equal to or higher than the predetermined luminance), the first system control unit 118 determines that the ambient light is bright. Ambient light corresponds to a scene when the network camera 100 takes pictures. If it is determined NO in S108, that is, if it is determined that the ambient light is dark, the first system control unit 118 sets the period (detection period) for detecting the phase of the light shielding curtain 501 to the second period (S109). ). Hereinafter, the second period is described as "1000 ms", but the second period may be any value.

The first system control unit 118 measures the time t for detecting the phase of the light shielding curtain 501 . Time t is the time that has elapsed since the phase of the light shielding curtain 501 was detected last time. The first system control unit 118 determines whether or not the time t has reached "1000 ms" (S110). Depending on the determination result of S110, it is determined whether to execute photometry processing for obtaining a photometric value without detecting the phase of the light shielding curtain 501 or to execute phase detection processing for detecting the phase of the light shielding curtain 501. . If the determination in S110 is NO, the flow moves to S107 in order to execute photometry processing. If the determination in S110 is YES, the flow moves to S104 in order to execute the phase detection process.

If the determination in S108 is YES, the photometric value is smaller than the first threshold. In this case, the first system control unit 118 determines that the ambient light is dark, and sets the period (detection period) for detecting the phase of the light shielding curtain 501 to the first period (S111). In this embodiment, the second period is longer than the first period. Hereinafter, the first period is described as "200 ms", but the first period may be any value. The first system control unit 118 determines whether or not the time t has reached "200 ms" (S112). Whether to execute the photometry process or the phase detection process is determined according to the determination result of S112. If the determination in S112 is NO, the flow moves to S107 in order to execute photometry processing. If the determination in S112 is YES, the flow moves to S104 in order to execute the phase detection process.

If the determination in step S104 is NO, the first system control unit 118 determines that the light shielding curtain 501 is closed even though the light shielding curtain 501 was opened in S102. . In other words, the phase detection circuit 504 obtains a detection result indicating that the phase state of the light shielding curtain 501 is not normal but abnormal. Therefore, the first system control unit 118 determines that the light shielding curtain 501 has an operation error. In this case, the network control unit 120 notifies a warning to the network device 130 (for example, client PC, etc.) (S113). Specifically, the first system control unit 118 detects the phase of the light shielding curtain 501 a predetermined number of times at predetermined intervals. 130 (client PC) is notified of an error warning.

As described above, in the first embodiment, the first system control unit 118 sets the period of executing the phase detection process to the first period or the second period based on the photometric values obtained periodically. You control what you do. As described above, while the network camera 100 is shooting for a long period of time, there is a possibility that the light shielding curtain 501 will be closed due to disturbance or the like. However, when the photometric value is equal to or greater than the first threshold (that is, when the ambient light is bright), the first system control unit 118 does not use the phase detection circuit 504, and the light shielding curtain is adjusted based on the photometric value (luminance). 501 is closed or not. Therefore, even if power is not supplied to the phase detection circuit 504, it is detected early that the light shielding curtain 501 is closed due to the influence of disturbance or the like. Therefore, the power supplied to the phase detection circuit 504 can be reduced.

On the other hand, when the photometric value is smaller than the first threshold (that is, when the ambient light is dark), the first system control unit 118 sets the cycle of acquiring the photometric value to the first cycle. The first cycle is a cycle set when the ambient light is dark, and is a cycle shorter than the second cycle. That is, when the ambient light is dark, the phase detection circuit 504 performs the phase detection of the light shielding curtain 501 with high frequency. When the ambient light is dark, compared to when the ambient light is bright, it is difficult to recognize from the photometric value that the light shielding curtain 501 has been closed due to the influence of a disturbance or the like. Therefore, when the ambient light is dark, the first system control unit 118 performs the phase detection process in the first period shorter than the second period, so that the light shielding curtain 501 is closed due to the influence of disturbance or the like. can be detected early.

Therefore, the first system control unit 118 can detect early that the light shielding curtain 501 has been closed due to disturbance or the like by controlling the cycle of executing the phase detection process according to the photometric value. , the power used in the phase detection circuit 504 can be reduced. That is, when the scene captured by the network camera 100 is bright, the phase detection cycle of the light shielding curtain 501 is lengthened, so that the power consumption of the phase detection circuit 504 can be reduced. Furthermore, since the energization time of the phase detection circuit 504 can be shortened, the deterioration due to the energization of the phase detection circuit 504 can be reduced. Also, even when the scene photographed by the network camera 100 is dark, the error detection performance of the light shielding curtain 501 equivalent to that of the conventional one can be ensured.

In the above example, the case where "1000 ms" is set as the second period has been described, but the second period may be "infinite". In this case, if the determination in S108 is NO, the periodical detection process is not executed, so it is possible to prevent the phase detection circuit 504 from being energized while the scene captured by the network camera 100 is bright. . Even in this case, it is possible to detect early that the light shielding curtain 501 has been closed due to the influence of disturbance or the like. Since the phase detection circuit 504 is not energized, the effect of reducing the power consumption of the phase detection circuit 504 can be enhanced.

<Second embodiment>
Next, a second embodiment will be described. The configuration of the network camera 100 of the second embodiment is the same as the configuration of the network camera 100 of the first embodiment, so the description thereof will be omitted. In the second embodiment, the first system control unit 118 detects whether or not the infrared cut filter 601 is inserted in the optical path of the light incident from the lens unit 111 so that the phase detection circuit 504 detects the light shielding curtain 501 . switch the period for detecting the phase of Further, the first system control unit 118 switches the period for the phase detection circuit 504 to detect the phase of the light shielding curtain 501 depending on whether infrared light is applied to the imaging target of the network camera 100 . Furthermore, in the second embodiment, the first system control unit 118 controls the timing of the phase detection processing of the light shielding curtain 501 by the phase detection circuit 504 according to the amount of change in the brightness of the ambient light.

The flow of processing according to the second embodiment will be described below with reference to the flowchart of FIG. In the flowchart of FIG. 6, S201 to S207 are the same as S101 to S107 of the flowchart of FIG. 5, and S216 is the same as S113 of the flowchart of FIG. The first system control unit 118 acquires the difference (amount of change in photometric value) between the previous photometric value and the latest photometric value. The amount of change in photometric value indicates the amount of change in luminance. In the second embodiment, the first system control unit 118 calculates “ΔEv=Eva−Evb” from the latest photometric value Evb acquired in step S207 and the photometric value Eva acquired in the previous period. This ΔEv represents the amount of decrease in the photometric value (luminance).

The Ev value increases as the brightness increases, and decreases as the brightness decreases. The first system control unit 118 determines whether ΔEv is equal to or greater than a predetermined value (second threshold) (S208). The first system control unit 118 determines that it has suddenly become dark when ΔEv is a positive value larger than a predetermined value, and determines that it has suddenly become brighter when ΔEv is a negative value larger than a predetermined value. do. If ΔEv is equal to or greater than the second threshold (predetermined amount) (YES in S208), that is, if it is determined that the ambient light has suddenly become dark, there is a possibility that the light shielding curtain 501 has closed due to some disturbance. In this case, the first system control unit 118 immediately causes the phase detection circuit 504 to detect the phase of the light shielding curtain 501 . Therefore, the flow moves to S204. Conversely, if ΔEv is smaller than the predetermined value (NO in S208), the flow moves to S209. When ΔEv is smaller than a predetermined value and has a positive value, it can be estimated that the ambient light has become darker, but not abruptly. Also, when ΔEv is a negative value, it can be estimated that there is a change in the bright direction. Accordingly, in the case of NO in S208, the first system control unit 118 determines that there is no error operation due to the light shielding curtain 510, and the flow proceeds to the next S209 without immediately proceeding to S204.

The first system control unit 118 obtains from the optical filter unit 117 whether or not the infrared cut filter 601 is positioned on the optical path of the light incident from the lens unit 111 . As described above, the optical filter unit 117 inserts the transmission glass 600 or the infrared cut filter 601 into the optical path of the light incident from the lens unit 111 . The first system control unit 118 determines whether the optical filter unit 117 has inserted the infrared cut filter 601 into the optical path of the light incident from the lens unit 111 (S209). When an image is captured without passing through the infrared cut filter 601 , light containing an infrared light component enters the image sensor 112 . Therefore, the network camera 100 can reduce the minimum illuminance that can be used to capture dark scenes, which is effective for capturing dark scenes. When the infrared cut filter 601 is inserted in the optical path of the light incident from the lens unit 111 (YES in S209), it is estimated that the ambient light is bright. If the infrared cut filter 601 is not inserted in the optical path of the light incident from the lens unit 111 (NO in S209), the ambient light is estimated to be dark.

If the determination in S209 is NO, the ambient light is estimated to be dark, so the first system control unit 118 sets the detection cycle to the first cycle as in S111 (S214). If the determination in S209 is YES, the first system control unit 118 determines whether the imaging target of the network camera 100 is irradiated with infrared light (S210). For example, at night or the like, an infrared lighting device (not shown) directly or indirectly connected to the network camera 100 irradiates an imaging target of the network camera 100 with infrared light. When an object to be imaged (object) is irradiated with infrared light by the infrared light illumination device, light of infrared light components is incident on the image sensor 112 through the lens unit 111 due to the object reflecting the infrared light. When light enters the image sensor without passing through the infrared cut filter 601, the luminance signal of the infrared light component is added to the luminance signal of the visible light component, resulting in a larger value, resulting in a brighter scene.

Here, the process of S210 is performed when it is determined as YES in S209. Therefore, the infrared cut filter 601 is in a state of being inserted in the optical path of the light incident from the lens unit 111, and luminance change due to infrared illumination is small. However, in the second embodiment, if YES is determined in S210, the first system control unit 118 determines that the image is intended to be shot in a dark scene. In this case, the first system control unit 118 sets the detection cycle to the first cycle at the timing of detecting that the infrared illumination is turned on (S214). When determined as NO in S210, the first system control unit 118 determines whether the photometric value is smaller than the first threshold (S211). When determined as NO in S211, the first system control unit 118 sets the period (detection period) for detecting the phase of the light shielding curtain 501 to the second period (S212). Then, the first system control unit 118 determines whether or not the time t has reached "1000 ms" (S213). If the determination in S215 is NO, the flow moves to S207 in order to execute photometry processing. If the determination in S215 is YES, the flow moves to S204 in order to execute phase detection processing.

If the determination in S211 is YES, the first system control unit 118 sets the cycle (detection cycle) for detecting the phase of the light shielding curtain 501 to the first cycle (S214). Then, the first system control unit 118 determines whether or not the time t has reached "200 ms" (S215). If the determination in S213 is NO, the flow shifts to S207 in order to execute photometry processing. If the determination in S213 is YES, the flow moves to S204 in order to execute phase detection processing.

As described above, in the second embodiment, the power consumption of the network camera 100 can be reduced as in the first embodiment. That is, it is possible to reduce the power consumption of the network camera 100 in a bright scene, and to perform error detection of the light shielding curtain 501 in a dark scene in the same manner as in the conventional art. Moreover, since the energization time of the phase detection circuit 504 is shortened, the service life can be lengthened. Furthermore, the responsiveness of error detection can be improved by performing the phase detection processing based on luminance changes in a bright scene. In the second embodiment, when the brightness suddenly changes from the "bright state" to the "dark state", the phase detection of the light shielding curtain 501 can be executed immediately, so the responsiveness of error detection can be improved. Furthermore, by setting the detection period to be as short as in the dark place shooting state, depending on the operation state of the infrared illumination and the insertion/removal state of the infrared cut filter 601, the phase detection performance of the light shielding curtain in the dark place can be ensured.

<Others>
Although the light shielding unit 116 in each of the above-described embodiments has been described as a mechanism that closes the light shielding curtain 501 when the power supply is cut off, it may be a mechanism that opens the light shielding curtain 501 when the power supply is cut off. For example, in a case where the light shielding curtain 501 is closed by a user's operation while the network camera 100 is operating, the light shielding curtain 501 may be configured to open when the power supply is cut off.

In addition, the first system control unit 118 acquires distance measurement information, and when the amount of change indicated by the acquired distance measurement information abruptly changes from telephoto to close-up (exceeds a predetermined threshold value), the first system control unit 118 immediately 501 may be controlled to confirm the phase. Conversely, the first system control unit 118 does not need to perform control to confirm the phase of the light shielding curtain 501 when the amount of change indicated by the acquired distance measurement information changes abruptly from close-up to telephoto. Also, when the network camera 100 detects an impact higher than a predetermined impact level, or detects a mechanical sound with a volume higher than a predetermined volume, the first system control unit 118 immediately adjusts the phase of the light shielding curtain 501. You may control to confirm.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. The present invention supplies a program that implements one or more functions of each of the above-described embodiments to a system or device via a network or a storage medium, and one or more processors of the computer of the system or device executes the program. It can also be realized by reading and executing processing. The invention can also be implemented by a circuit (eg, an ASIC) that implements one or more functions.

100 network camera 110 imaging unit 112 imaging device 116 light shielding unit 117 optical filter unit 118 first system control unit 120 network control unit 504 phase detection circuit

Claims (9)

a detection means for detecting a light shielding means for shielding light incident on the imaging device;
a control means for periodically acquiring luminance information of light incident on the imaging element and controlling a cycle of detecting the light shielding means based on the periodically acquired luminance information;
An imaging device comprising: When the luminance indicated by the luminance information is smaller than a predetermined luminance, the control means causes the detection means to detect the light shielding means in a first cycle, and when the luminance is equal to or higher than the predetermined luminance, the light shielding means. is detected by the detection means in a second period longer than the first period,
2. The imaging apparatus according to claim 1, wherein: The detection means is a photointerrupter,
power is supplied to the photointerrupter in the first cycle or the second cycle according to the luminance;
3. The imaging apparatus according to claim 2, wherein: The control means performs the detection in response to detection that the decrease amount of the brightness is larger than a predetermined amount when the light shielding means is detected in the first period or the second period. causing a means to detect the light blocking means;
4. The imaging apparatus according to claim 2, wherein: When an infrared cut filter is inserted in the optical path of the incident light to the imaging element, the control means controls the period of detecting the light blocking means to the second period, and the infrared cut filter is inserted. If not, controlling the cycle of detecting the light blocking means to the first cycle;
5. The imaging apparatus according to any one of claims 2 to 4, characterized in that: When the object to be imaged by the imaging device is irradiated with infrared light, the control means controls the cycle of detecting the light shielding means to be the first period, and the infrared light is irradiated onto the object to be imaged. if not, controlling the cycle of detecting the light blocking means to the second cycle;
6. The imaging apparatus according to any one of claims 2 to 5, characterized by: After the light shielding means is controlled to be in an open state, the control means controls the cycle of detecting the light shielding means or notifies a warning according to the detection result of the light shielding means by the detection means. Control,
7. The imaging apparatus according to any one of claims 1 to 6, characterized by: a step of detecting light shielding means for shielding light incident on the imaging element;
a step of periodically obtaining luminance information of light incident on the imaging device, and controlling a period of detecting the light shielding means based on the luminance information obtained periodically;
A control method for an imaging device, comprising: A program for causing a computer to execute the control method of the imaging apparatus according to claim 8 .

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