Imaging device

Abstract

To prevent detection light for detecting the position of a filter from being incident on an image pickup device during the imaging operation while suppressing increase in the size of a device.SOLUTION: An imaging device 10 comprises: a filter unit which includes a first filter 181 and a second filter 182; a movement unit 190 which moves the filter unit; a detection unit 200 which detects the position of the filter unit; a storage unit which stores the filter unit, the movement unit 190 and the detection unit 200; an image pickup device 13 which receives light that has passed through the filter unit to convert the light into an image signal; and a filter control unit 34 which controls the start and stop of emission of detection light from a detection light source 201 of the detection unit 200. The movement unit 190 arranges one of the first filter 181 and the second filter 182 between the image pickup device 13 and an opening 15. The filter control unit 34 causes the detection light source 201 to start emission of the detection light at prescribed timing and causes the detection light source 201 to stop emission of the detection light when the movement of the filter unit terminates.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an imaging device. [Background technology]

[0002] Surveillance cameras are installed in various locations, such as nursing homes, hospitals, factories, and stores, for crime prevention and disaster prevention purposes. Depending on the environment in which a surveillance camera, which is an imaging device, is installed, the area around the surveillance camera may be darker at night than during the day, making surveillance difficult. For this reason, some surveillance cameras are known that turn on auxiliary lighting devices to illuminate the monitored object with infrared light when the surroundings are dark, and cut off infrared light and capture images using visible light when the surroundings are bright.

[0003] Patent Document 1 describes a surveillance camera that selectively places an infrared cut filter or a glass member on the optical path of a lens barrel based on the measured illuminance.

[0004] Patent Document 2 describes a filter device that switches between an ND filter and a visible light cut filter. In this filter device, the filters are switched by rotating a disk-shaped turret on which the ND filter and the visible light cut filter are arranged on the same circumference. Patent Document 2 also describes that a photointerrupter can be used as a means for detecting the rotational position of the turret. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2019-97046 [Patent Document 2] JP 2012-198410 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, providing a photointerrupter outside the unit where the filter is provided increases the size of the device, and providing a photointerrupter inside the unit where the filter is provided causes the detection light from the photointerrupter to enter the image sensor, adversely affecting the generated image. [Means for solving the problem]

[0007] An imaging device according to one aspect of the present invention includes an illumination light source that emits illumination light to illuminate a subject, a filter unit having a first region that does not allow the illumination light to pass and a second region that allows the illumination light to pass, a moving unit that moves the filter unit, a detection unit having a detection light source that emits detection light to detect the position of the filter unit and a light receiving unit that receives the detection light, a housing unit that houses the filter unit, the moving unit, and the detection unit, an imaging unit that receives light that has passed through an opening and passed through the filter unit housed in the housing unit and converts it into an image signal, and a control unit that controls start and stop of emission of the detection light from the detection light source. The moving unit moves the filter unit to position either the first region or the second region between the imaging unit and the opening. The control unit causes the detection light source to start emitting the detection light at a predetermined timing, and causes the detection light source to stop emitting the detection light when the detection unit detects that the movement of the filter unit has ended. [Effects of the Invention]

[0008] According to the present invention, it is possible to control the start and stop of the emission of detection light for detecting the position of the filter section, thereby suppressing deterioration in the image quality of the generated image caused by the detection light being captured by the imaging section while the photographing device is photographing. [Brief explanation of the drawings]

[0009] [Figure 1] 1A and 1B are perspective views showing the appearance of an imaging device according to an embodiment. [Figure 2] 1A is a plan view of the interior of the imaging device, and FIG. 1B is a cross-sectional view of the imaging device. [Figure 3] 10A, 10B, and 10C are perspective views showing the appearance of the switching unit. [Figure 4] FIG. 2 is a block diagram showing a control system of the imaging apparatus. [Figure 5] 10A, 10B, and 10C are diagrams illustrating the operation of a switching unit when switching the imaging mode between a normal imaging mode and a night vision mode. [Figure 6] 10 is a flowchart illustrating the operation of the imaging device. [Figure 7] 10 is a flowchart illustrating the operation of the imaging device. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an imaging device according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0011] The imaging device is suitable for use as a surveillance camera or a monitoring camera in hospitals, nursing homes, factories, stores, etc., but is not particularly limited thereto. The imaging device is switchable between a capture-enabled state and a capture-disabled state. More specifically, the imaging device is switchable between a closed state in which light is not allowed to enter the imaging optical system and an open state in which light is allowed to enter the imaging optical system. When the imaging device is switched to the capture-disabled state (closed state), the person being photographed can recognize that the imaging device has been switched to the capture-disabled state. The imaging device is also switchable between a normal imaging mode and a night vision mode depending on the brightness of the surrounding external environment. In the normal imaging mode, imaging is performed using light incident on the imaging optical system when the external environment is bright. In the night vision mode, illumination light is emitted when the external environment is dark, and an image of a subject illuminated by the illumination light is captured.

[0012] Figures 1(A) and (B) are external views of an imaging device 10. Figure 1(A) is an external view of the imaging device 10 in an open state, and Figure 1(B) is an external view of the imaging device 10 in a closed state. Figure 2(A) is a plan view of the interior of the imaging device 10, and Figure 2(B) is a cross-sectional view of the imaging device 10 taken along line aa in Figure 2(A).

[0013] 1 and 2, imaging device 10 has a housing 12 that is substantially rectangular parallelepiped in shape. Housing 12 has a front portion 12a, a back portion 12b, and side portions 12c, 12d, 12e, and 12f that are connected to each side of front portion 12a. In the following description, the direction of front portion 12a of housing 12 will also be referred to as the upper side, the direction of back portion 12b as the lower side, the direction of side portion 12c as the near side, the direction of side portion 12d as the left side, and the direction of side portion 12f as the right side.

[0014] The front portion 12a of the housing 12 is provided with a card slot 24 into which a memory card 48 (see FIG. 4) is inserted, an opening 15, illumination light sources 161 and 162, and an illuminance meter 17. The side portion 12d is provided with a power port 26 to which a power cable is connected.

[0015] The illumination light sources 161 and 162 are, for example, LEDs, and emit light having a wavelength in the infrared range (infrared rays, infrared light). When capturing an image in a night vision mode, which will be described later, the imaging device 10 emits infrared light from the illumination light sources 161 and 162 as illumination light for illuminating the subject.

[0016] The illuminance meter 17 is, for example, a photoresistor or a photodiode, and receives light from the environment (external environment) surrounding the image capture device 10 and outputs a signal (brightness signal). That is, the illuminance meter 17 functions as an illuminance unit that detects the brightness outside the image capture device 10.

[0017] 2(A) and 2(B), the housing 12 of the imaging device 10 contains a lens cover 11, an imaging element 13 which is an image sensor such as a CMOS or CCD, a lens (imaging optical system) 14 which focuses light from a subject (subject light) onto the imaging surface of the imaging element 13, a switching unit 18, and a control unit 31. As shown in FIG. 2(B), the lens cover 11, the imaging element 13, the lens 14, and the switching unit 18 are arranged parallel to the front surface 12a.

[0018] An opening 15 provided in the front portion 12a of the housing 12 is formed on the optical axis of the lens 14. Subject light that passes through the opening 15 is incident on the image sensor 13 via the lens (imaging optical system) 14. The image sensor 13 is an imaging unit that receives light that has passed through a filter unit 180 provided in a holder 210 of the switching unit 18, the details of which will be described later, of the light that enters through the opening 15 provided in the housing 12, and performs photoelectric conversion to output an image signal. An image processing unit 35 (see FIG. 4), which will be described later, performs various processes on the image signal output from the image sensor 13 to generate image data.

[0019] The lens cover 11 for opening and closing the opening 15 is disposed between the lens 14 and the opening 15 along the optical axis of the lens 14. The lens cover 11 is provided so as to be movable between an open position where the opening 15 is opened and a closed position where the opening 15 is closed. The lens cover 11 moves on a plane perpendicular to the optical axis of the lens 14 (i.e., a plane parallel to the front surface 12a). When the lens cover 11 moves to the open position, the lens cover 11 moves away from the optical axis of the lens 14, and the opening 15 formed on the optical axis of the lens 14 is opened (open state) as shown in FIG. 1(A). This allows the lens 14 to be exposed from the opening 15 of the housing 12, allowing subject light to enter the image sensor 13 through the lens 14.

[0020] When the lens cover 11 is moved to the closed position, the opening 15 of the housing 12 is closed by the lens cover 11 (closed state) as shown in FIG. 1(B). This allows the lens 14 to be covered by the lens cover 11, thereby protecting the lens 14 inside the housing 12. When the lens cover 11 is located at the closed position shown in FIG. 1(B), it also functions as a light blocking section that limits the incidence of subject light on the imaging element 13. The lens cover 11 is also called a lens barrier, shutter, etc.

[0021] The switching unit 18 switches between a state in which illumination light from the illumination light sources 161 and 162 is not allowed to enter the imaging element 13 and a state in which illumination light is allowed to enter the imaging element 13, depending on the brightness (luminance) of the external environment around the imaging device 10. Details of the switching unit 18 will be described later.

[0022] The substrate 31a is a base member that holds the imaging element 13, the control unit 31, and the switching unit 18. The substrate 31a is provided inside the housing 12 on the rear surface 12b side.

[0023] The control unit 31 is composed of a CPU, memory, etc. The control unit 31 is a processor that controls each part of the imaging device 10 by reading and executing a control program pre-recorded in a recording medium 38 (see FIG. 4), such as a flash memory. The control unit 31 also performs a determination process to determine whether the external environment around the imaging device 10 is bright or dark, based on the luminance signal output from the illuminance meter 17. If the result of the determination process indicates that the external environment is bright, the imaging mode of the imaging device 10 is set to normal imaging mode, and if the external environment is dark, the imaging mode is set to night vision mode. Details of the process executed by the control unit 31 will be described later.

[0024] <Regarding the switching unit 18> Figure 3 is a perspective view of the switching unit 18. Figure 3(A) is a perspective view of the switching unit 18 as seen from the front part 12a side, Figure 3(B) is a perspective view of the switching unit 18 as seen from the back part 12b side, and Figure 3(C) is a perspective view of the switching unit 18 as seen from the back part 12b side with a holder, which will be described later, removed.

[0025] The switching unit 18 has a filter unit 180, a moving unit 190, and a detection unit 200, which are housed inside a holder 210, which is a housing unit. The holder 210 is disposed on the substrate 31a so as to be located above the imaging element 13. As shown in FIG. 3(A), a lens 14 is provided on the upper part (front part 12a side) of the holder 210.

[0026] The filter unit 180 has a first filter 181, a second filter 182, and a holding unit 183. The first filter 181 is an infrared cut filter, and functions as a first region that does not allow infrared light to pass through and enter the image sensor 13. The second filter 182 is a dummy lens or the like, and functions as a second region that allows infrared light to pass through and enter the image sensor 13.

[0027] The holding portion 183 is a holding frame that holds the first filter 181 and the second filter 182 in a plane parallel to the front portion 12a. As shown in FIG. 2(B), the holding portion 183 is disposed between the image sensor 13 and the lens 14 and parallel to the imaging surface of the image sensor 13. The holding portion 183 is formed of, for example, a metal material. Therefore, the holding portion 183 can obtain sufficient strength to hold the first filter 181 and the second filter 182 without increasing the thickness of the lens 14 in the optical axis direction.

[0028] The holding unit 183 holds the first filter 181 on the side of the side surface 12f (right side) and the second filter 182 on the side of the side surface 12d (left side) along the direction in which guide rails 195, 196 of the moving unit 190 (described later) extend (the direction of the arrow AR in FIG. 2A). When the holding unit 183 moves along the arrow AR in FIG. 2A, either the first filter 181 or the second filter 182 is positioned on the optical axis of the lens 14 (i.e., between the image sensor 13 and the opening 15). In the following description, the position of the holding unit 183 when the first filter 181 is positioned on the optical axis of the lens 14 will be referred to as the first position, and the position of the holding unit 183 when the second filter 182 is positioned on the optical axis of the lens 14 will be referred to as the second position. Note that FIGS. 2A, 3B, and 3C show the holding unit 183 positioned at the second position.

[0029] Holding unit 183 is provided with connecting units 184 and 185 and a light-shielding unit 186. Connecting unit 184 is provided on the side surface 12c side of holding unit 183. One part of connecting unit 184 is movably connected to guide rail 195, and another part of connecting unit 184 has a screw formed therein that meshes with a lead screw 194 of moving unit 190, which will be described later. Connecting unit 185 is provided on the side surface 12e side of holding unit 183. Connecting unit 185 is movably connected to guide rail 196. Connecting units 184 and 185 to guide rails 195 and 196, respectively, connects holding unit 183 to moving unit 190 so as to be movably in the direction of arrow AR in FIG. 2(A).

[0030] The light-shielding portion 186 is provided at the end of the connecting portion 185 on the side of the side surface portion 12e, and is a plate-like member having a light-shielding surface parallel to the imaging surface of the imaging element 13. The light-shielding portion 186 moves in the direction in which the guide rail 196 extends together with the holding portion 183, which is moved by the moving portion 190 described later. When the holding portion 183 is moving, the light-shielding portion 186 blocks detection light emitted from the detecting portion 200 described later.

[0031] The moving unit 190 has a driving unit 191, a first gear 192, a second gear 193, a lead screw 194, and guide rails 195 and 196. The driving unit 191 is, for example, a stepping motor, and is controlled by a control unit 31, which will be described later. A driving signal (pulse signal) from the control unit 31, which will be described later, is input to a driver of the driving unit 191, thereby controlling the rotation angle, rotation speed, etc. of the driving unit 191. The rotation angle of the driving unit 191 is proportional to the number of pulses, and the rotation speed of the driving unit 191 is proportional to the pulse frequency.

[0032] 2(A) 。 Guide rails 195, 196 are provided parallel to each other along the direction of arrow AR in Fig. 2 (A). First gear 192 is connected to a rotation shaft that is the center of rotation of drive unit 191, and rotates in response to the rotation of drive unit 191. Second gear 193 is meshed with first gear 192, and when first gear 192 is rotated by drive unit 191, second gear 193 rotates in response to the rotation of first gear 192.

[0033] The lead screw 194 is connected to a rotation axis that is the center of rotation of the second gear 193, and extends parallel to the guide rail 195 in the direction of the arrow AR in FIG. 2A. When the second gear 193 rotates in response to the rotation of the first gear 192, the lead screw 194 rotates in response to the rotation of the second gear 193. A thread is formed on the lead screw 194, and meshes with a thread formed on a part of the above-mentioned connecting portion 184. When the lead screw 194 rotates, the connecting portion 184 connected via the thread moves relative to the lead screw 194. At this time, the connecting portion 184 is guided by the connected guide rail 195 and moves in the direction of the arrow AR in FIG. 2A. As the connecting portion 184 moves, the holding portion 183 and the connecting portion 185 connected to the guide rail 196 move in the direction of the arrow AR in FIG. 2A.

[0034] The movement direction of connecting portion 184, i.e., the movement direction of holding portion 183, can be changed by switching the rotation direction of drive portion 191. For example, when drive portion 191 is rotated forward, lead screw 194 rotates clockwise and holding portion 183 moves from the first position to the second position. When drive portion 191 is rotated reversely, lead screw 194 rotates counterclockwise and holding portion 183 moves from the second position to the first position. In other words, by switching the rotation direction of drive portion 191, one of first filter 181 and second filter 182 can be positioned on the optical axis of lens 14.

[0035] The detection unit 200 is a photointerrupter having a detection light source 201 and a light receiving unit 202 provided at a position facing the detection light source 201. The detection light source 201 is, for example, an LED, and emits light having a wavelength in the infrared range (infrared light, infrared light) as detection light toward the light receiving unit 202. The light receiving unit 202 is, for example, a phototransistor, and upon receiving the detection light emitted from the detection light source 201, generates an electrical signal of a value (current value) according to the amount of light received, and outputs the electrical signal to the control unit 31 as a detection signal.

[0036] When the light-shielding portion 186 provided in the holding portion 183 described above does not pass between the detection light source 201 and the light-receiving portion 202, the detection light is not blocked by the light-shielding portion 186. Therefore, the light-receiving portion 202 receives the detection light from the detection light source 201 and outputs a large current value as a detection signal. On the other hand, when the light-shielding portion 186 provided in the holding portion 183 described above is passing between the detection light source 201 and the light-receiving portion 202, the detection light is blocked by the light-shielding portion 186 and is not received by the light-receiving portion 202. Therefore, the light-receiving portion 202 outputs a small current value as a detection signal. This allows the control unit 31 to detect the position of the holding portion 183 according to the magnitude of the current value obtained as the detection signal.

[0037] <Regarding the control system of the imaging device 10> 4 is a block diagram showing a control system of the imaging device 10. As shown in FIG. 4, the control unit 31 of the imaging device 10 has an imaging control section 33, a filter control section 34, and a recording medium 38.

[0038] The imaging control unit 33 performs imaging processing by controlling the driving of the imaging element 13 to generate an image signal and causing the image processing unit 35 to generate image data from the image signal. When imaging in night vision mode, the imaging control unit 33 supplies power to the illumination light sources 161 and 162 to emit infrared light as illumination light.

[0039] The filter control unit 34 controls the start and end of emission of detection light from the detection light source 201 of the detection unit 200. The filter control unit 34 also controls the start and end of a movement operation that moves the filter unit 180. As a movement operation, the filter control unit 34 controls the movement of the holder 183 by driving the drive unit 191 based on the set shooting mode, thereby placing either the first filter 181 or the second filter 182 on the optical axis of the lens 14. In this case, when shooting in the normal shooting mode, the filter control unit 34 places the first filter 181, which is an infrared cut filter, on the optical axis of the lens 14, and when shooting in the night vision mode, the filter control unit 34 places the second filter 182, which is a dummy lens, on the optical axis of the lens 14. That is, when shooting in the normal shooting mode, the filter control unit 34 positions the holder 183 at a first position, and when shooting in the night vision mode, the filter control unit 34 positions the holder 183 at a second position.

[0040] An actuator 44 is connected to the lens cover 11, which opens and closes the opening 15, via a link mechanism 43. A drive circuit 45 is connected to the actuator 44. The drive circuit 45 is connected to the control unit 31, and drives the actuator 44 in response to a control signal (drive signal) from the control unit 31.

[0041] <Regarding the processing of the control unit 31> The imaging device 10 starts capturing images when a capturing execution condition is satisfied, such as when a wireless tag such as an IC tag approaches within a predetermined range, when a recording signal transmitted from a mobile terminal such as a smartphone is received, when infrared rays transmitted from a remote control are received, or when predetermined audio content is detected by a microphone (not shown).

[0042] When the shooting execution conditions are met, the imaging device 10 moves the lens cover 11 from the closed position to the open position and shoots the subject. That is, the control unit 31 causes the drive circuit 45 to drive the actuator 44, which moves the lens cover 11 to the open position via the link mechanism 43. Furthermore, when the shooting execution conditions are no longer met, the control unit 31 causes the drive circuit 45 to drive the actuator 44, which moves the lens cover 11 to the closed position via the link mechanism 43.

[0043] When the lens cover 11 is moved to the open position, the image sensor 13 receives subject light that has passed through the opening 15 and is incident thereon, and outputs an image signal to the image processing unit 35. The image processing unit 35 is an image processor (ISP). The image processing unit 35 performs known image processing, including, for example, AD conversion processing, signal amplification processing, white balance processing, etc., on the image signal output from the image sensor 13 to generate image data.

[0044] Furthermore, a determination process is performed by the control unit 31. In this case, the control unit 31 calculates a luminance value based on the luminance signal output from the illuminance meter 17, and determines that the external environment is bright if this value is equal to or greater than a predetermined threshold, and determines that the external environment is dark if the value is less than the threshold. The predetermined threshold is set based on the results of tests and simulations, and is recorded in advance on the recording medium 38.

[0045] <Normal shooting mode> If the luminance value detected by the illuminance meter 17 is equal to or greater than the threshold value and the surrounding external environment is determined to be bright, the imaging device 10 sets the imaging mode to the normal imaging mode and performs imaging. In the normal imaging mode, the filter control unit 34 controls the moving unit 190 to position the first filter 181 on the optical axis of the lens 14. That is, in a state where no infrared light is incident, the imaging element 13 performs photoelectric conversion and outputs an image signal. The image processing unit 35 uses this image signal to generate image data.

[0046] <About night vision mode> If the luminance value detected by the illuminance meter 17 is less than the threshold value and the surrounding external environment is determined to be dark, the imaging device 10 is set to the night vision mode and captures an image. In the night vision mode, when the external environment is dark and the amount of light is insufficient, the imaging device 10 irradiates infrared light as illumination light and captures an image of a subject illuminated by this infrared light. The filter control unit 34 controls the moving unit 190 to move the first filter 181 away from the optical axis of the lens 14 and position the second filter 182 on the optical axis of the lens 14. This allows infrared light to enter the imaging element 13. Thereafter, the imaging control unit 33 causes the illumination light sources 161 and 162 to emit infrared light as illumination light, as described above.

[0047] Since the second filter 182 is located on the optical axis of the lens 14, the image sensor 13 receives the light reflected by the subject out of the illumination light emitted from the illumination light sources 161 and 162, and outputs an image signal. The image processing unit 35 generates image data using the image signal.

[0048] <Switching between normal shooting mode and night vision mode> The operation of the switching unit 18 when switching between the normal shooting mode and the night vision mode will be described with reference to Figure 5. Figures 5(A) to 5(C) are perspective views seen from the rear surface 12b side with the holder 210 removed, similar to Figure 3(C). Figure 5(A) shows the case where the holding unit 183 is located at the second position in the night vision mode. Figure 5(B) shows the case where the holding unit 183 is located midway between the first and second positions. Figure 5(C) shows the case where the holding unit 183 is located at the first position in the normal shooting mode.

[0049] The imaging mode is switched at a predetermined timing when the luminance of the external environment detected by the illuminometer 17 changes from below the threshold to above the threshold (when the external environment becomes brighter), or when the luminance of the external environment changes from above the threshold to below the threshold (when the external environment becomes darker). At this predetermined timing, the filter control unit 34 controls the switching unit 18 to switch between the first filter 181 and the second filter 182, and causes the detection light source 201 of the detection unit 200 to emit detection light.

[0050] When the control unit 31 determines to switch the imaging mode between the normal imaging mode and the night vision mode, the filter control unit 34 energizes the detection unit 200, turns on the detection light source 201 to emit detection light, and energizes the drive unit 191 of the movement unit 190 of the switching unit 18, outputting a drive signal to move the holding unit 183. In other words, the filter control unit 34 synchronizes the start of emission of detection light from the detection light source 201 with the start of the movement operation by the movement unit 190.

[0051] 5(A), when the holding unit 183 is in the second position, the detection unit 200 is located to the left (toward the side surface 12d) of the left end of the light-shielding unit 186. Therefore, the light-shielding unit 186 does not block the detection light from the detection light source 201, and the detection light is received by the light-receiving unit 202. Therefore, the current value, which is the detection signal from the light-receiving unit 202, becomes the first value. In order to switch the imaging mode from the night vision mode to the normal imaging mode from this state, the filter control unit 34 drives the drive unit 191, for example, counterclockwise at a predetermined number of rotations.

[0052] 5(B), when the holder 183 starts to move as a result of being driven by the driver 191, the light-shielding portion 186 passes between the detection light source 201 and the light-receiving portion 202 of the detector 200, blocking the detection light from entering the light-receiving portion 202. Therefore, while the holder 183 is moving, the current value, which is the detection signal from the light-receiving portion 202, becomes a second value that is smaller than the first value when the holder 183 is located at the second position.

[0053] 5(C), when the light-shielding portion 186 moves to the first position, the detection portion 200 is positioned to the right (toward the side surface portion 12f) of the right end portion of the light-shielding portion 186. Therefore, the light-shielding portion 186 does not block the detection light from the detection light source 201, and the detection light is received by the light-receiving portion 202. Therefore, the current value, which is the detection signal from the light-receiving portion 202, becomes a first value.

[0054] On the other hand, when switching the imaging mode from the normal imaging mode to the night vision mode, the filter control unit 34 drives the drive unit 191, for example, at a predetermined number of rotations clockwise. In this case, the holding unit 183 moves from the first position shown in Fig. 5(C) through the state shown in Fig. 5(B) to the second position shown in Fig. 5(A). In this case, the detection signal from the light receiving unit 202 changes the current value from the first value to the second value and then back to the first value, just as when switching from the night vision mode to the normal imaging mode.

[0055] When the filter control unit 34 detects that the current value of the detection signal has changed from the second value to the first value again, the filter control unit 34 determines that the movement of the holding unit 183 has been completed. When the movement of the holding unit 183 has been completed, the filter control unit 34 stops supplying electricity to the detection unit 200, turns off the detection light source 201, and ends the emission of the detection light. Then, the filter control unit 34 stops supplying electricity to the drive unit 191, stops outputting the drive signal, and ends the movement of the filter unit 180 by the movement unit 190. In other words, the filter control unit 34 synchronizes the end of the emission of the detection light from the detection light source 201 with the end of the movement operation by the movement unit 190.

[0056] Switching between normal and night vision modes with reference to the flowcharts shown in FIGS. 6 and 7 edge 6 and 7 show the processes executed by the control unit 31. Each process shown in the flowchart is executed by the control unit 31 reading out a program recorded on the recording medium 38 and executing the program. The flowcharts shown in FIGS. 6 and 7 show the processes executed when switching from the night vision mode to the normal shooting mode.

[0057] The flowcharts shown in FIGS. 6 and 7 start when the control unit 31 determines that the luminance of the external environment detected by the illuminance meter 17 has changed from below the threshold to above the threshold.

[0058] 6, the filter control unit 34 starts energizing the detection unit 200 to cause the detection light source 201 to emit detection light, and energizes the drive unit 191 to start a movement operation. Then, the process proceeds to step S2. In step S2, the control unit 31 reads a detection signal from the light receiving unit 202 of the detection unit 200. Then, the process proceeds to step S3.

[0059] In step S3, the filter control unit 34 determines whether or not the detection unit 200 is shielded by the light-shielding unit 186, based on the detection signal read in step 2. If the current value that is the detection signal is a first value, the filter control unit 34 determines that the detection unit 200 is not shielded by the light-shielding unit 186 (positive determination), and the process proceeds to step S4. If the current value that is the detection signal is a second value, the filter control unit 34 determines that the detection unit 200 is shielded by the light-shielding unit 186 (negative determination), and the process proceeds to step S8, which will be described later.

[0060] In step S4, the filter control unit 34 drives the drive unit 191 counterclockwise by one step. Thereafter, the process proceeds to step S5. In step S5, the filter control unit 34 determines whether the detection unit 200 is blocked by the light-blocking unit 186 based on the detection signal from the light-receiving unit 202. If the current value that is the detection signal is a second value, the filter control unit 34 determines that the detection unit 200 is blocked by the light-blocking unit 186 (positive determination), and the process proceeds to step S12, which will be described later. If the current value that is the detection signal is a first value, the filter control unit 34 determines that the detection unit 200 is not blocked by the light-blocking unit 186 (negative determination), and the process proceeds to step S6.

[0061] In step S6, the filter control unit 34 determines whether the value of the counter that counts the number of rotations of the drive unit 191 is 300. If the counter value is 300, the filter control unit 34 makes a positive determination, and the process proceeds to step S7. In step S7, the filter control unit 34 stops power supply to the detection unit 200, thereby stopping the emission of detection light from the detection light source 201, and also stops power supply to the drive unit 191, thereby ending the movement operation. Then, the control unit 31 considers this to be an error and ends all processes.

[0062] By performing the processes of steps S4 to S6, it can be determined whether first filter 181 and second filter 182 are moving appropriately in accordance with the movement of the filters by drive unit 191. If detection unit 200 is not blocked even when drive unit 191 is driven before the counter reaches 300, it is considered that first filter 181 and second filter 182 are not operating appropriately. Therefore, when a negative determination is made in step S6 and the process of step S7 is executed, control unit 31 treats this as an error and terminates all processes.

[0063] If the counter value is not 300 in step S6, the filter control unit 34 makes a negative determination, and the process returns to step S4. At this time, the filter control unit 34 adds 1 to the counter value. By repeating the processes of steps S4 to S6 described above, it is confirmed whether the holding unit 183 is correctly positioned at the second position, and the holding unit 183 is moved from the second position. of It can be moved.

[0064] In step S8, to which the process proceeds after a negative determination in step S3, the filter control unit 34 drives the drive unit 191 one step clockwise. Thereafter, the process proceeds to step S9. In step S9, the filter control unit 34 determines whether or not the detection unit 200 is shielded by the light-shielding unit 186, based on the detection signal. If the current value that is the detection signal is a first value, the filter control unit 34 determines that the detection unit 200 is not shielded by the light-shielding unit 186 (positive determination), and the process proceeds to step S12, which will be described later. If the current value that is the detection signal is a second value, the filter control unit 34 determines that the detection unit 200 is shielded by the light-shielding unit 186 (negative determination), and the process proceeds to step S10.

[0065] In step S10, the filter control unit 34 determines whether the value of the counter that counts the number of rotations of the drive unit 191 is 100. If the counter value is 100, the filter control unit 34 makes a positive determination, and the process proceeds to step S11. In step S11, the filter control unit 34 stops power supply to the detection unit 200, thereby stopping the emission of detection light from the detection light source 201, and also stops power supply to the drive unit 191, thereby ending the movement operation. Then, the control unit 31 considers this to be an error and ends all processes.

[0066] If the counter value is not 100 in step S10, a negative determination is made by the filter control unit 34, and the process returns to step S8. At this time, the filter control unit 34 adds 1 to the counter value. By repeating steps S8 to S10, the holder 183 that has shifted from the position can be positioned at the second position.

[0067] In step S12, the filter control unit 34 resets the counter value of the drive unit 191. Thereafter, the process proceeds to step S13 in FIG. 7. In step S13 in FIG. 7, the filter control unit 34 rotates the drive unit 191 counterclockwise by one step. Thereafter, the process proceeds to step S14. In step S14, the filter control unit 34 determines whether the counter value is 124. If the counter value is not 124, the filter control unit 34 makes a negative determination, and the process returns to step S13. At this time, the filter control unit 34 adds 1 to the counter value. If the counter value is 124 in step S14, the filter control unit 34 makes an affirmative determination, and the process proceeds to step S15.

[0068] In step S15, the filter control unit 34 determines, based on the detection signal, whether or not the detection unit 200 is shielded by the light-shielding unit 186. If the current value that is the detection signal is a first value, the filter control unit 34 determines that the detection unit 200 is not shielded by the light-shielding unit 186 (positive determination), and the process proceeds to step S16. In step S16, the filter control unit 34 stops power supply to the detection unit 200 to stop emission of the detection light from the detection light source 201, stops power supply to the drive unit 191 to end the movement operation, and ends all processes.

[0069] If the current value that is the detection signal is the second value in step S15, the filter control unit 34 determines that the detection unit 200 is blocked by the light blocking unit 186 (negative determination), and the process proceeds to step S17. In step S17, the filter control unit 34 further rotates the drive unit 191 counterclockwise by one step, and the process returns to step S15.

[0070] The above-described flowchart shows the process for switching from the night vision mode to the normal shooting mode. When switching from the normal shooting mode to the night vision mode, if it is determined that the brightness of the external environment has darkened from above the threshold to below the threshold, the process shown in Figures 6 and 7 is started, and the drive unit 191 is rotated clockwise in steps S4, S13, and S17, and then rotated counterclockwise in step S8.

[0071] According to the above-described embodiment, the following effects can be obtained.

[0072] (1) The switching unit 18 of the imaging device 10 has a filter unit 180, a moving unit 190, and a detection unit 200 inside a holder 210, which is a storage unit. The filter unit 180 has a first filter 181, which is a first region, and a second filter 182, which is a second region. The moving unit 190 moves the filter unit 180 to position either the first filter 181 or the second filter 182 between the imaging element 13 and the opening 15. The detection unit 200 has a detection light source 201 that emits detection light for detecting the position of the filter unit 180, and a light receiving unit 202 that receives the detection light. The filter control unit 34 of the control unit 31 of the imaging device 10 causes the detection light source 201 to start emitting the detection light at a predetermined timing, and when the detection unit 200 detects that the movement of the filter unit 180 has ended, causes the detection light source 201 to stop emitting the detection light. This allows the detection unit 200 to be housed inside the holder 210, which prevents the image capture device 10 from becoming larger, unlike when the detection unit 200 is disposed outside the holder 210. Furthermore, since it is possible to control the emission and stopping of detection light from the detection light source 201, it is possible to prevent a deterioration in the image quality of image data generated by the image processing unit 35, which would be caused by the detection light emitted from the detection light source 201 housed in the holder 210 being incident on the image capture element 13 during image capture operation.

[0073] (2) When the brightness detected by the illuminance meter 17 changes to a brightness that exceeds the threshold value, or when the brightness detected by the illuminance meter 17 changes to a brightness that falls below the threshold value, the filter control unit 34 causes the detection light source 201 to emit detection light, and the movement unit 190 moves the filter unit 180. As a result, the detection light is emitted from the detection light source 201 at the timing when the shooting mode switches between the normal shooting mode and the night vision mode, so that the detection light does not enter the image sensor 13 during shooting, and degradation in the quality of the generated image data can be prevented.

[0074] (3) The filter control unit 34 synchronizes the emission of detection light by the detection light source 201 with the start of the movement operation of the filter unit 180 by the movement unit 190, and synchronizes the stop of emission of detection light by the detection light source 201 with the end of the movement operation by the movement unit 190. This causes the period during which the detection light source 201 emits detection light to coincide with the period during which the filter unit 180 moves, and the detection light source 201 does not emit detection light while image capture is being performed by the image sensor 13. Therefore, detection light does not enter the image sensor 13 during image capture, and degradation in the quality of the generated image data can be prevented.

[0075] Although various embodiments and modifications have been described above, the present invention is not limited to these. Other embodiments that are conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention.

[0076] The filter control unit 34 may synchronously energize the detection unit 200 and the drive unit 191, but may not synchronously terminate energization of the detection unit 200 and the drive unit 191. That is, the filter control unit 34 may energize the detection unit 200 and the drive unit 191 at different times, or may terminate energization of the detection unit 200 and the drive unit 191 at different times. When energization of the detection unit 200 and the drive unit 191 is synchronized, for example, the detection unit 200 and the drive unit 191 are connected to the same port of the control unit 31. This allows the control unit 31 to simultaneously control the detection unit 200 and the drive unit 191 by outputting a signal from one port.

[0077] In addition to the operation of the embodiment in which the filter control unit 34 energizes the detection unit 200 and causes the detection light source 201 to emit detection light when the shooting mode is switched in response to a change in the brightness of the external environment, the detection light source 201 may also emit detection light at predetermined time intervals. That is, even when shooting is being performed in normal shooting mode or night vision mode, the filter control unit 34 uses the detection unit 200 to detect the position of the holding unit 183 of the filter unit 180 at predetermined time intervals. This makes it possible to detect, for example, a state in which the position of the holding unit 183 is displaced from the first position or the second position due to vibration or the like being applied to the imaging device 10. When the above-described positional displacement of the holding unit 183 is detected, the filter control unit 34 may drive the drive unit 191 to move the holding unit 183 to the first position or the second position. [Explanation of symbols]

[0078] 10...imaging device, 13...imaging element, 14...lens (imaging optical system), 15...opening, 17...illuminance meter, 18...switching unit, 31...control unit, 34...filter control unit, 35...image processing unit, 161, 162...illumination light source, 180...filter unit, 181...first filter, 182...second filter, 183...holding unit, 186...light-shielding unit, 190...moving unit, 191...driving unit, 200...detecting unit, 201...detection light source, 202...light-receiving unit, 210...holder

Claims

1. an illumination light source that emits illumination light to illuminate an object; a filter section having a first region that does not allow the illumination light to pass through and a second region that allows the illumination light to pass through; a moving unit that moves the filter unit; a detection unit having a detection light source that emits detection light for detecting the position of the filter unit and a light receiving unit that receives the detection light; a housing section that houses the filter section, the moving section, and the detecting section; an imaging unit having an imaging optical system that condenses light from the subject and an imaging element that receives light that has passed through the imaging optical system and converts it into an image signal; a housing having an opening and accommodating the accommodating section and the imaging section therein; a control unit that controls start and stop of emission of the detection light from the detection light source, the opening and the housing are provided on an optical axis of the imaging optical system, the housing is located between the imaging optical system and the image sensor, and the image sensor receives light that has passed through the opening and the imaging optical system and the filter unit housed in the housing and converts the light into the image signal; the moving unit has a driving unit that rotates to move the filter unit in a direction intersecting the optical axis and disposes either the first region or the second region between the imaging unit and the opening, the control unit causes the detection light source to start emitting the detection light at a predetermined timing, and when the movement of the filter unit is completed, causes the detection light source to stop emitting the detection light; The control unit rotates the drive unit by a predetermined amount before moving the filter unit to position either the first region or the second region between the imaging unit and the opening, and determines whether the filter unit is operating properly or corrects any positional misalignment of the filter unit based on the amount of detection light received by the light receiving unit.

2. 2. The imaging device according to claim 1, It has an illuminance unit that detects the brightness of the external environment, the control unit further controls the start and end of a moving operation of the moving unit to move the filter unit, an imaging device in which the control unit causes the detection light source to emit the detection light and causes the moving unit to start the moving operation when the brightness detected by the illuminance unit changes to a brightness above a threshold value or a brightness below the threshold value, which is determined as the specified timing.

3. 3. The imaging device according to claim 2, The control unit synchronizes the start of emission of the detection light by the detection light source with the start of the moving operation by the moving unit, and synchronizes the stop of emission of the detection light by the detection light source with the end of the moving operation by the moving unit.

4. 4. The imaging device according to claim 3, The imaging device, wherein the detection light source and the moving unit are connected to the same port of the control unit.

5. In the imaging device according to claim 1, an imaging device, wherein when the amount of light of the detection light is a first value, the control unit rotates the drive unit in a first direction, and determines that the filter unit is operating if the amount of light of the detection light is a second value smaller than the first value before the drive unit rotates by the predetermined amount, and determines that the filter unit is not operating if the amount of light of the detection light is the first value.

6. In the imaging device according to claim 5, When the amount of detected light is the second value, the control unit rotates the drive unit in a second direction opposite to the first direction, thereby correcting positional deviation of the filter unit.

Images