WO2010029747A1

WO2010029747A1 - Imaging device and camera body

Info

Publication number: WO2010029747A1
Application number: PCT/JP2009/004492
Authority: WO
Inventors: 櫻井幹夫; 青木泰造
Original assignee: パナソニック株式会社
Priority date: 2008-09-11
Filing date: 2009-09-10
Publication date: 2010-03-18
Also published as: JP2012015567A

Abstract

The imaging device is equipped with an imaging element (201) for photographing a subject and generating image data, an optical element (221) that is provided between an optical system for forming the photographed subject image and the imaging element, a vibration means (222) for vibrating the optical element, and a drive means (223) for driving the vibration means. The drive means drives the vibration means for the duration of a first drive time when the power of the imaging device is turned from OFF to ON and drives the vibration means for the duration of a second drive time when a vibration command is received from outside of the imaging device. The first drive time is shorter than the second drive time.

Description

Imaging device and camera body

The present invention relates to an imaging apparatus or a camera body to which an interchangeable lens can be attached, and more particularly to an imaging apparatus or a camera body having a dust removing function of an imaging element.

Conventionally, in an imaging apparatus, there has been a problem that foreign matter such as dust attached to an optical element such as an optical filter disposed in front of the imaging element is reflected in the captured image data.

Such dust is one that has entered the camera body from the outside when the lens is replaced, or that is generated by the operation of the shutter or mirror inside the camera body. It is considered that dust generated with the operation of the shutter and mirror inside the camera body is caused by fine wear powder such as resin and metal due to the operation of these members.

In order to avoid such a problem, various techniques for removing dust adhering to the optical element by vibrating the optical element provided in front of the imaging element have been proposed.

For example, Patent Document 1 discloses a technique in which at least one of vibration amplitude, vibration time, and vibration direction of an optical element is set based on the state of the imaging device, and the optical element is vibrated based on this setting. .

Japanese Patent Laid-Open No. 2008-42400

The imaging apparatus disclosed in Patent Document 1 is configured to perform a dust removal operation when the power is turned on. However, the time from when the power is turned on until the camera body can shoot is not considered. There is a case where the user wants to take a picture immediately after the power supply of the image pickup apparatus is turned from OFF to ON. However, in the image pickup apparatus of Patent Document 1, it takes time to remove dust when the power supply of the image pickup apparatus is turned on. After turning on the device, it takes time until imaging is possible. For this reason, there exists a possibility that a user may miss a photo opportunity.

The present invention has been made to solve the above-described problems, and the object of the present invention is to efficiently remove foreign matter adhering to the optical element while taking into account the time until the imaging apparatus can shoot. An imaging device is provided.

In a first aspect of the present invention, an imaging apparatus including an interchangeable lens and a camera body is provided. The imaging apparatus includes an imaging element that captures a subject image and generates image data, an optical element that is disposed between an optical system that forms the subject image and the imaging element, and an excitation that vibrates the optical element. Means and driving means for driving the vibration means. The drive means drives the vibration means during the first drive time when the power supply of the image pickup apparatus is turned from OFF to ON, and the second drive means receives the vibration instruction from the outside of the image pickup apparatus. The excitation means is driven during the drive time. The first driving time is shorter than the second driving time.

With this configuration, the vibration time of the optical element in the dust removal operation that is performed when the power of the imaging apparatus is turned on can be made shorter than the vibration time in the dust removal operation that is performed when an instruction from the outside is received. Accordingly, it is possible to efficiently remove the foreign matter adhering to the optical element while considering the startup time of the imaging device. That is, when the power is turned on, the removal operation can be performed in consideration of missing a photo opportunity, and when an instruction is received from the outside, the removal operation is performed in consideration of dust removal. Can do.

In a second aspect of the present invention, an imaging apparatus including an interchangeable lens and a camera body is provided. The imaging apparatus includes an imaging element that captures a subject image and generates image data, an optical element that is disposed between an optical system that forms the subject image and the imaging element, and an excitation that vibrates the optical element. Means and driving means for driving the vibration means. When the control mode of the image pickup apparatus is an image pickup mode for picking up an image, the drive means drives the vibration means for the first drive time and reproduces the image picked up by the control mode of the image pickup apparatus. In this case, the vibrating means is driven for the second driving time. The first driving time is longer than the second driving time.

This configuration makes it possible to vary the vibration time of the optical element in the dust removal operation according to the control mode. In other words, in the playback mode where the influence of dust adhesion is low, the vibration time of the dust removal operation is shortened, and in the imaging mode where the influence of dust adhesion is high, the vibration time is lengthened to reduce the power consumption as a whole. When removal is necessary, dust can be removed more reliably.

In a third aspect of the present invention, a camera body to which an interchangeable lens can be attached is provided. The camera body includes an imaging element that captures a subject image and generates image data, an optical element that is disposed between the optical system that forms the subject image and the imaging element, and a vibration unit that vibrates the optical element. When,
Drive means for driving the excitation means. The drive means drives the vibration means during the first drive time when the power supply of the apparatus is turned from OFF to ON, and the second drive means receives the vibration instruction from the outside of the imaging apparatus. The excitation means is driven during the drive time. The first driving time is shorter than the second driving time.

The imaging apparatus of the present invention makes the vibration time of the optical element in the dust removal operation executed when the power is turned on shorter than the vibration time in the dust removal operation executed when an instruction from the outside is received. Thereby, the foreign matter adhering to the optical element can be efficiently removed while taking into consideration the time until the imaging apparatus can take a picture. That is, the dust removal operation time when the power of the image pickup apparatus is turned on can be shortened, so that the image pickup apparatus can quickly take a picture and the user can be prevented from losing a photo opportunity.

The perspective view of the digital camera in

Embodiment

1, 2 of this invention 1 is a block diagram showing a configuration example of a digital camera according to

Embodiments

1 and 2 of the present invention. The figure for demonstrating the relationship between the operation timing of the dust removal function in Embodiment 1 of this invention, and the drive time of an optical filter. The figure for demonstrating the drive method of a piezoelectric element Diagram for explaining the driving method of the piezoelectric element (switching of driving time) Diagram for explaining driving method of piezoelectric element (change in resolution of driving frequency) The figure for demonstrating the drive method of a piezoelectric element Diagram for explaining the driving method of the piezoelectric element (switching of driving time) Diagram for explaining driving method of piezoelectric element (change in resolution of driving frequency) Diagram for explaining how to drive a piezoelectric element (change of amplitude) Flowchart for explaining an operation example of the camera body in the first embodiment of the present invention The figure for demonstrating the relationship between the operation timing of the dust removal function in Embodiment 2 of this invention, and the drive time of an optical filter. Flowchart for explaining an operation example of the camera body in the second embodiment of the present invention.

DESCRIPTION OF SYMBOLS 1 Digital camera 2 Camera body 3 Interchangeable lens 201 CMOS sensor 202 Mechanical shutter 203 Signal processor 204 Buffer memory 205 Liquid crystal monitor 206 Electronic view funder 207 Battery 208 Body mount 209 Flash memory 211 CPU
212 Shutter switch 221 Optical filter 222 Piezoelectric element 223 Drive circuit 224 Dust reduction switch 225 Power button 301 Lens mount 311 Lens controller 314 Flash memory

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following embodiments, a digital camera will be described as an example of an imaging apparatus.

(Embodiment 1)
1. Configuration 1-1 Overview of Overall Configuration FIG. 1 is a perspective view of a digital camera 1 according to the present embodiment. FIG. 2 is a configuration diagram of the digital camera 1 according to the present embodiment.

As shown in FIG. 1, the digital camera 1 of the present embodiment includes a camera body 2 and an interchangeable lens 3 that can be attached to and detached from the camera body 2.

As shown in FIG. 2, the camera body 2 includes a CMOS sensor 201, a mechanical shutter 202, a signal processor 203 (DSP), a buffer memory 204, a liquid crystal monitor 205, an electronic viewfinder 206 (EVF), a battery 207, a body mount 208, A flash memory 209, a card slot 210, a CPU 211, a shutter switch 212, a strobe 213, a microphone 214, a speaker 215, and a mode switching dial 230 are provided. The camera body 2 includes an optical filter 221, a piezoelectric element 222, and a drive circuit 223.

The interchangeable lens 3 includes an objective lens 302, a lens mount 301, a lens system including a zoom lens 303 and a focus lens 304, a zoom lens driving unit 305 that drives the zoom lens 303, a focus driving unit 306 that drives the focus lens 304, and an aperture. 307, an aperture driving unit 308 that drives the aperture 307, a zoom ring 309, a focus ring 310, a lens controller 311, a buffer memory 312 and a flash memory 314.

1-2 Configuration of Camera Body The camera body 2 is configured to capture a subject image condensed by the lens system of the interchangeable lens 3 and record the captured image data on a storage medium (memory card or the like). Yes.

The CMOS sensor 201 includes a light receiving element, an AGC (gain control amplifier), and an AD converter. The light receiving element converts the optical signal collected by the lens system into an electrical signal, and generates image data. The AGC amplifies the electric signal output from the light receiving element. The AD converter converts an analog electric signal output from the AGC into a digital signal. Note that the CMOS sensor 201 performs various operations such as exposure, transfer, and electronic shutter in accordance with control signals received from the CPU 211. These various operations can be realized by a timing generator or the like.

The optical filter 221 is a member provided between the optical system of the interchangeable lens 3 and the CMOS sensor 201. The optical filter 221 is, for example, an LPF or a quartz birefringent plate separated from the LPF. The optical filter 221 is also a member that prevents dust from adhering to the light receiving surface of the CMOS sensor. A piezoelectric element 222 is bonded to the optical filter 221. A drive circuit 223 is connected to the piezoelectric element 222. The optical filter 221 is configured to be vibrated by the piezoelectric element 222. The piezoelectric element 222 expands and contracts when a voltage having a certain period is applied from the drive circuit 223. When the piezoelectric element 222 expands and contracts, the optical filter 221 vibrates with the expansion and contraction. Since the technique for vibrating such an optical filter is a known technique, a description thereof is omitted here.

The drive circuit 223 can vibrate the optical filter 221 with the vibration time and amplitude set by the control of the CPU 211.

The mechanical shutter 202 is an optical member that switches between blocking and passage of an optical signal incident through the lens system with respect to the CMOS sensor 201. The mechanical shutter 202 is driven by a mechanical shutter driving unit. The mechanical shutter drive unit includes mechanical parts such as a motor and a spring, and drives the mechanical shutter 202 based on the control of the CPU 211. In short, the mechanical shutter 202 adjusts the amount of light hitting the CMOS sensor 201 in time by opening and closing. The mechanical shutter 202 is provided in the same space as the optical filter 221. That is, the dust adhering to the mechanical shutter 202 is shaken off from the mechanical shutter 202 when the mechanical shutter 202 operates. At this time, a part of the dust shaken off from the mechanical shutter 202 can float in the space in the camera body provided with the mechanical shutter 202 and the optical filter 221 and adhere to the optical filter 221.

The signal processor 203 (DSP) performs predetermined image processing on the image data converted into a digital signal by the AD converter. Examples of the predetermined image processing include gamma conversion, YC conversion, electronic zoom processing, compression processing, and expansion processing, but are not limited thereto.

The buffer memory 204 functions as a work memory when the signal processor 203 performs processing and when the CPU 211 performs control processing. The buffer memory 204 can be realized by, for example, a DRAM.

The liquid crystal monitor 205 is arranged on the back surface of the camera body 2 and can display image data generated by the CMOS sensor 201 or image data obtained by performing predetermined processing on the image data. Here, when the image signal input to the liquid crystal monitor 205 is output from the signal processor 203 to the liquid crystal monitor 205, it is converted from a digital signal to an analog signal by the DA converter.

The electronic viewfinder 206 is arranged in the camera body 2 and can display image data generated by the CMOS sensor 201 or image data obtained by performing predetermined processing on the image data. Similarly, when an image signal input to the electronic viewfinder 206 is output from the signal processor 203 to the electronic viewfinder 206, the digital signal is converted from an analog signal by a DA converter.

The liquid crystal monitor 205 and the electronic viewfinder 206 are switched by the display switching means 217 so that an image is displayed only on one of them. In other words, the image is not displayed on the electronic viewfinder 206 while the image is displayed on the liquid crystal monitor 205, and the image is not displayed on the liquid crystal monitor 205 while the image is displayed on the electronic viewfinder 206. It is configured. The display switching unit 217 can be realized by a physical member such as a changeover switch, for example. For example, when the signal processor 203 and the liquid crystal monitor 205 are electrically connected via a changeover switch, the electrical connection between the signal processor 203 and the liquid crystal monitor 205 is cut off by switching the changeover switch. The processing processor 203 and the electronic viewfinder 206 are electrically connected. The display is not limited to the above example, and the display may be switched between the liquid crystal monitor 205 and the electronic viewfinder 206 based on a control signal from the CPU 211 or the like.

As described above, the display on the liquid crystal monitor and the display on the electric viewfinder are switched. However, this is only an example, and display on the liquid crystal monitor and display on the electronic viewfinder may be performed simultaneously. Here, when displaying simultaneously, the image displayed on the liquid crystal monitor and the image displayed on the electronic view funder may be the same image or different images.

The battery 207 supplies power for driving the digital camera 1. The battery 207 may be, for example, a dry battery or a rechargeable battery. Further, instead of the battery 207, electric power supplied from outside via a cord may be supplied to the digital camera 1 as a power source.

The body mount 208 is a member that enables the interchangeable lens 3 to be mounted together with the lens mount 301 of the interchangeable lens 3. The body mount 208 can be electrically connected to the interchangeable lens 3 via a connection terminal or the like, and can be mechanically connected to the interchangeable lens 3 via a mechanical member such as a locking member. The body mount 208 can output a signal from the lens controller 311 included in the interchangeable lens 3 to the CPU 211 and can output a signal from the CPU 211 to the lens controller 311 of the interchangeable lens 3. That is, the CPU 211 can transmit and receive control signals, information on the lens system, and the like with the lens controller 311 on the interchangeable lens 3 side via the body mount 208 and the lens mount 301. The body mount 208 also supplies power for driving the interchangeable lens 3 from the battery 207 to the lens controller 311.

The flash memory 209 is a storage medium used as a built-in memory. The flash memory 209 can store image data or image data obtained by performing predetermined processing on the image data. Also, digitized audio signals can be stored. In addition, it is possible to store programs and set values for controlling the CPU 211 in addition to image data and audio signals.

The card slot 210 is a slot for installing the memory card 218. The memory card 218 is a storage medium capable of storing image data or image data obtained by performing predetermined processing on the image data. Also, digitized audio signals can be stored.

CPU 211 controls the entire camera body 2. The CPU 211 may be realized by a microcomputer or a hard wired circuit. That is, the CPU 211 executes various controls.

The shutter switch 212 is a button provided on the upper surface of the camera body 2, and detects a half-press and a full-press operation by the user. The shutter switch 212 outputs a half-press signal to the CPU 211 when receiving a half-press operation by the user. On the other hand, when the shutter switch 212 receives a full-press operation from the user, the shutter switch 212 outputs a full-press signal to the CPU 211. Based on these signals, the CPU 211 performs various controls. In the present embodiment, the full press signal is a shooting start signal.

The strobe 213 irradiates the subject with light based on a control signal from the CPU 211.

The microphone 214 converts sound into an electrical signal. The electrical signal output from the microphone 214 is converted into a digital signal by an AD converter. The digital signal converted by the AD converter is stored in the flash memory 209 or the memory card 218 under the control of the CPU 211.

The speaker 215 converts an electrical signal into sound. Here, the electrical signal input to the speaker 215 is a signal converted from a digital signal to an electrical signal by a DA converter. As the output to the DA converter, a digital signal read from the flash memory 209 or the memory card 218 is output under the control of the CPU 211.

The mode switching dial 230 is an operation member attached outside the camera body 2. The mode switching dial 230 is configured in a substantially circular shape, and one control mode can be selected from a plurality of control modes when the user rotates. That is, the mode switching dial 230 can detect the rotational position of the mode switching dial 230 corresponding to the control mode so that one of a plurality of control modes can be selected. The plurality of control modes include “still image shooting mode”, “moving image shooting mode”, “playback mode”, and the like. For example, when an image indicating “still image shooting mode” described on the upper surface of the mode switching dial is moved to a predetermined position (selected position), the mode switching dial 230 is changed to “still image shooting mode”. A mode switching signal indicating this is output to the CPU 211. Thereby, switching of the control mode can be detected.

The dust reduction switch 224 is an operation member provided outside the camera body 2. The dust reduction switch 224 transmits an operation signal to the CPU 211 when operated by the user. The CPU 211 performs control for vibrating the optical filter 221 based on the operation signal. As a result, the user can operate the dust reduction switch 224 to vibrate the optical filter 221 and remove dust adhering to the optical filter 221 (dust removal function). Note that the dust reduction switch 224 is configured with a dedicated button, but it may be shared with other switches. In addition, the user may be allowed to select an operation for executing the dust removal operation from the display image displayed on the liquid crystal monitor.

The power button 225 switches the power supply of the camera body 2 between OFF and ON. When the power button 225 is operated by the user, power is supplied from the battery 207 to each member of the camera body 2.

Note that the power-off state of the present embodiment is not limited to turning off the power supply from the battery 207 to all the components of the camera body 2. In other words, power may be supplied to some components and the components may be operating. For example, a timer that measures time can be considered for some of the components. That is, the power OFF state is a state in which power is not supplied to the main function of the camera body 2, that is, a part for realizing the photographing function.

1-3 Configuration of Interchangeable Lens The interchangeable lens 3 includes a lens system that collects light from the subject. The lens system includes a zoom lens 303, a focus lens 304, and an objective lens 302. The zoom lens 303 is driven by the zoom drive unit 305 or the zoom ring 309 and adjusts the zoom magnification. The focus lens 304 is driven by the focus driving unit 306 or the focus ring 310 to adjust the focus.

It should be noted that the optical system of the interchangeable lens 3 may further include an OIS lens for preventing image blur due to the blur of the digital camera 1. The OIS lens can bend the optical axis of the optical system by moving in a plane perpendicular to the optical axis of the optical system. Specifically, by moving the OIS lens in a direction that cancels out the shake of the digital camera 1 detected by the gyro sensor, it is possible to prevent image blur due to the shake of the digital camera 1.

The focus drive unit 306 is configured to drive the focus lens 304 according to the control of the lens controller 311. The focus driving unit 306 can be realized by a stepping motor and a driver, for example. The focus driving unit 306 receives power from the lens controller 311 and drives the focus lens 304.

The diaphragm 307 is for adjusting the amount of light passing through the lens system. For example, the light can be adjusted by increasing or decreasing the opening formed by five blades or the like.

The aperture drive unit 308 changes the size of the aperture of the aperture 307. In the first embodiment, the size of the opening of the diaphragm 307 is changed based on the control of the lens controller 311. Here, the size of the opening can be designated by the AV value. The diaphragm driving unit 308 drives the diaphragm 307 based on the control from the lens controller 311. However, the diaphragm driving unit 308 is not limited to this and may be driven by a mechanical method.

The diaphragm driving unit 308 includes an encoder that detects the size (position) of the aperture of the diaphragm and outputs it as an AV (Aperture Value) value. The aperture driving unit 308 outputs the AV value to the lens controller 311. AV values output from the aperture driving unit 308 are, for example, AV “1” to “6”.

The zoom ring 309 is provided outside the interchangeable lens 3 and drives the zoom lens 303 in accordance with an operation from the user. The zoom ring 309 mechanically drives the zoom lens 303 when rotated by the user.

The focus ring 310 is provided on the exterior of the interchangeable lens 3 and drives the focus lens 304 in accordance with an operation from the user. When the focus ring 310 is rotated by the user, the sliding resistance detects the operation, and a signal related to the operation is input to the lens controller 311. The lens controller 311 controls the focus driving unit 306 in accordance with the input operation related signal. As a result, the focus driving unit 306 drives the focus lens 304.

The lens controller 311 performs various controls for controlling the operation of the entire interchangeable lens 3. The lens controller 311 may be realized by a microcomputer or a hard wired circuit.

The lens controller 311 receives the request signal from the CPU 211, reads the identification ID from the flash memory 314 in response to the received request signal, and transmits the read identification ID to the CPU 211.

The buffer memory 312 functions as a work memory when the lens controller 311 performs control processing. The buffer memory 312 can be realized by, for example, a DRAM.

The flash memory 314 is configured to be electrically connected to the lens controller 311. The flash memory 314 can store a control program, parameters, and the like (for example, an identification ID of an interchangeable lens).

2. 2. Operation 2.1 Switching of Dust Removal Operation Time The digital camera 1 having the above configuration can execute a dust removal operation of driving the piezoelectric element to vibrate the optical filter 221 and removing dust attached on the optical filter 221. It is. In the present embodiment, the dust removal operation is executed at the timing shown in FIG. That is, it is executed at the following timing.
1) When the camera body 2 is turned on 2) When lens replacement (mounting) is detected while the camera body 2 is turned on 3) When the camera body 2 is turned on, the user gives an instruction to execute dust reduction When (when dust reduction switch 224 is operated)
4) When the camera body 2 is turned off

When executing the dust removal operation when the camera body 2 is turned on, the optical filter 221 is vibrated with a driving time of 200 msec. When the optical filter 221 is driven when lens replacement is detected, the optical filter 221 is vibrated at 400 msec. Further, when the optical filter 221 is driven in accordance with the user's dust reduction operation, the optical filter 221 is vibrated at 800 msec. When the dust removal operation is executed when the power of the camera body 2 is turned off, the optical filter 221 is vibrated with a drive time of 600 msec.

As described above, the camera body 2 makes the vibration time in the dust removal operation executed when the power is turned on shorter than the vibration time in the dust removal operation executed under other conditions. As a result, the dust removal operation can be quickly completed when the power is turned on while the dust attached to the optical filter 221 is removed by the dust removal operation that is performed when the power is turned on. Therefore, when the power is turned on, the digital camera can be quickly brought into an imageable state, and the opportunity for the user to lose the shutter chance is reduced.

On the other hand, when the user actively vibrates the optical filter 221 as in the case of performing a dust removal operation during the user's dust reduction operation, the camera body 2 sets the vibration time of the optical filter 221 at another timing. It is longer than if executed. Accordingly, when the user wants to positively remove the dust on the optical filter 221, the dust can be efficiently removed. That is, since the vibration time of the optical filter 221 (per operation) is short, dust cannot be removed, and the troublesomeness that the user has to execute the dust removal operation many times can be reduced.

Here, in this embodiment, in one dust removal operation, the optical filter 221 is vibrated while switching the driving frequency of the piezoelectric element 222 a plurality of times. 4A to 4C and 5A to 5C are diagrams illustrating switching of the driving frequency of the piezoelectric element 222 in the dust removing operation. 4A to 4C, the horizontal axis indicates the driving frequency, and the vertical axis indicates the amplitude of the optical element. 5A to 5C correspond to FIGS. 4A to 4C, respectively, and more clearly show the relationship between the drive time and the drive frequency. For example, in the example of FIG. 4A, the frequency is switched from f1 → f2 → f3 every predetermined time (100 msec).

Specifically, the CPU 211 controls the drive circuit 223 to vibrate the optical filter 221 while switching the frequency every predetermined time (vibration time). Therefore, the CPU 211 controls the output time, drive frequency, switching time, and the like of PWM (Pulse Width Modulation) with respect to the drive circuit 223. For example, for convenience of explanation, an example in which the driving time is 300 msec will be described. In order to vibrate the optical filter 221 for 300 msec, the drive circuit 223 applies the voltages of the respective drive frequencies (f1, f2, f3,...) For a predetermined drive time as shown in FIGS. 4A and 5A, for example. Applied every (100 msec). That is, the drive circuit 223 first applies a voltage of the drive frequency f1 to the piezoelectric element 222 for 100 msec. Next, the drive circuit 223 applies a voltage having a drive frequency f2 to the piezoelectric element 222 for 100 msec. Next, the drive circuit 223 applies a voltage having a drive frequency f3 to the piezoelectric element 222 for 100 msec. Thus, the drive circuit 223 drives the piezoelectric element 222 at a predetermined frequency every predetermined time, and vibrates the optical filter 221. Due to the vibration of the optical filter 221, dust attached to the optical filter 221 is removed.

When changing the drive time of the piezoelectric element 222 (the operation time of the dust removal operation), for example, the drive time can be adjusted by the following two methods. The first method is a method for adjusting the driving time for each driving frequency, and the second method is a method for adjusting the resolution of the driving frequency.

First, a method for adjusting the drive time for each drive frequency, which is the first method, will be described. Below, the example which sets drive time to 600 msec is demonstrated. In this case, as shown in FIGS. 4B and 5B, the drive circuit 223 sets the voltage application time of one drive frequency (f1, f2, f3) to 200 msec. As a result, the driving time is 600 msec in total, and the optical filter 221 can be vibrated by driving the piezoelectric element 222 for 600 msec.

Next, a method for adjusting the resolution of the driving frequency, which is the second method, will be described. In this case, as shown in FIGS. 4C and 5C, the drive circuit 223 switches the voltage application time of the plurality of drive frequencies (f11 to f16) every 100 msec. As a result, the driving time becomes 600 msec in total, and the optical filter 221 can be vibrated by driving the piezoelectric element 222 for 600 msec.

As described above, the drive time of the piezoelectric element 222 (the operation time of the dust removal operation) can be adjusted by adjusting the drive time for each frequency and the resolution of the drive frequency. It is possible to lengthen or shorten the driving time by changing the frequency band (primary resonance, secondary resonance, tertiary resonance, etc.) for driving the piezoelectric element. In addition, the drive time can be extended by performing the same drive a plurality of times.

Also, in the dust removal operation, it is conceivable to vibrate the optical filter 221 while switching the amplitude of vibration instead of switching the frequency (see FIG. 6). That is, the CPU 211 may control the drive circuit 223 so as to vibrate the optical filter 221 while switching the vibration amplitude every predetermined time. In the piezoelectric element 222, the amplitude of vibration changes according to the applied voltage. Therefore, in order to change the vibration amplitude of the optical filter 221, the magnitude of the voltage applied to the piezoelectric element 222 may be changed. Therefore, the CPU 211 controls the drive circuit 223 to change the output voltage to the piezoelectric element 222. Specifically, when the vibration amplitude of the optical filter 221 is desired to be increased, the voltage applied to the piezoelectric element 222 is increased, and when the vibration amplitude of the optical filter 221 is desired to be decreased, the voltage applied to the piezoelectric element 222 is decreased.

2.2 Dust Removal Operation The dust removal operation of the digital camera 1 will be described in detail using the flowchart of FIG. First, it is assumed that the power source of the camera body 2 is in an OFF state.

The CPU 211 controls the optical filter 221 to vibrate with a vibration time of 200 msec when the power source of the camera body 2 is turned on from OFF (S1) (S2). That is, the CPU 211 controls the drive circuit 223 so as to drive the piezoelectric element 222 with a drive time of 200 msec. For example, when switching three types of drive frequencies in the examples of FIGS. 4A and 5A, control is performed so that each drive frequency is switched every (200/3) msec.

The CPU 211 determines whether or not the interchangeable lens has been replaced (mounted) (S3). Details of the detection operation for exchanging the interchangeable lens will be described later. When the replacement of the interchangeable lens is detected, that is, when the same or different interchangeable lens is mounted after the interchangeable lens is once removed, the CPU 211 removes the optical filter 221 with a driving time of 400 msec to remove dust. Control to vibrate (S4). This is because it is considered that dust may enter from the opening of the camera body 2 and adhere to the optical filter 221 during lens replacement. That is, if the lens is replaced, the possibility of dust attachment increases, so the drive time of the dust removal operation is lengthened. On the other hand, if the lens is not replaced, the possibility of dust attachment decreases, so the dust removal Reduce the drive time of the operation. As a result, wasteful power consumption can be suppressed, so that foreign matter adhering to the optical element can be efficiently removed while considering power consumption.

On the other hand, when the replacement of the interchangeable lens is not detected, the CPU 211 determines whether or not the dust reduction switch 224 is operated (S5). When the dust reduction switch 224 is operated, the CPU 211 controls the optical filter 221 to vibrate in a drive time of 800 msec (S6). On the other hand, when the dust reduction switch 224 is not operated, the CPU 211 shifts the operation to step S7.

In step S7, the CPU 211 determines whether or not the power source of the camera body 2 has been turned off from on (S7). When the power source of the camera body 2 is switched from ON to OFF, the CPU 211 controls the optical filter 221 to vibrate in a drive time of 600 msec (S8). On the other hand, when the power of the camera body 2 remains on, the CPU 211 returns to step S3 and repeats the above operation.

As described above, the digital camera 1 vibrates the optical filter 221 at the operation timing and the drive time (vibration time) as shown in FIG. In particular, in FIG. 3, the drive time (200 msec) of the optical filter 221 in the dust removal operation executed when the power is turned on is shorter than the drive time (800 msec) of the optical filter 221 in the dust removal operation executed during the dust reduction operation. It is set. As a result, when the digital camera 1 is powered on, the digital camera 1 can be quickly brought into an imageable state, the loss of a photo opportunity can be prevented, and the user performs an operation for intentionally removing dust. Can more reliably remove dust.

2.2.1 Lens Exchange Detection Operation An interchangeable lens exchange detection operation will be described.

The CPU 211 can determine whether or not the interchangeable lens 3 is mounted by determining whether or not the electrical contact between the body mount 208 and the lens mount 301 is connected. That is, the CPU 211 can communicate with the lens controller 311 when the electrical contacts of the body mount 208 and the lens mount 301 are connected. Therefore, if the CPU 211 can detect that communication with the lens controller 311 is possible, the CPU 211 determines that the interchangeable lens 3 is attached. Conversely, if the electrical contact between the body mount 208 and the lens mount 301 is not connected and it is not possible to detect that communication with the lens controller 311 is possible, the CPU 211 determines that the interchangeable lens 3 is not attached. . In the above example, the attachment / non-attachment of the interchangeable lens 3 is determined by determining whether the electrical contact between the body mount 208 and the lens mount 301 is connected / not connected. However, a mechanical switch is provided on the camera body 2. The mounting / non-mounting of the interchangeable lens 3 may be detected by a change in the state of the mechanical switch.

Furthermore, the CPU 211 can determine whether or not the interchangeable lens has been replaced. The detection operation for exchanging the interchangeable lens will be specifically described. In the following description, first, it is assumed that the interchangeable lens 3 is not attached to the camera body 2 and the power supply of the camera body 2 is in the ON state. Further, it is assumed that the identification ID of the interchangeable lens is stored in the flash memory 314 of the interchangeable lens 3.

For example, when an interchangeable lens having an identification ID “001” (hereinafter referred to as “first interchangeable lens”) is newly attached to the camera body 2, the CPU 211 makes a request for requesting the identification ID of the first interchangeable lens. The signal is transmitted to the lens controller 311. In response to the request signal, the lens controller 311 transmits the identification ID “001” read from the flash memory 314 to the CPU 211.

When the CPU 211 acquires the identification ID “001” from the lens controller 311, the CPU 211 stores it in the flash memory 209. Thereafter, when the power button 225 of the camera body 2 is operated by the user, the camera body 2 changes the power state from ON to OFF.

In the state where the power source of the camera body 2 is OFF, the interchangeable lens is referred to as an interchangeable lens having the identification ID “002” (hereinafter referred to as “second interchangeable lens”) from the first interchangeable lens (identification ID “001”). ).

Thereafter, when the power button 225 is operated by the user, the camera body 2 changes the power state from OFF to ON. When the camera body 2 is turned on, the camera body 2 transmits a request signal for requesting an identification ID to the second interchangeable lens (lens controller 311). In response to the request signal, the lens controller 311 transmits the identification ID “002” read from the flash memory 314 to the CPU 211. When acquiring the identification ID “002”, the CPU 211 reads the identification ID “001” stored in the flash memory 209 and compares it with the acquired identification ID “002”. When the acquired identification ID is different from the read identification ID, the CPU 211 determines that the interchangeable lens has been changed to another interchangeable lens when the power is off. On the other hand, when the acquired identification ID and the read identification ID are the same, the CPU 211 determines that the interchangeable lens has not been changed when the power is off. If the interchangeable lens has been changed to another interchangeable lens when the power is off, the CPU 211 stores the acquired identification ID in the flash memory 209. As described above, the camera body 2 can detect the presence or absence of lens replacement in the power OFF state by referring to the identification ID stored in the flash memory 209. In the above example, the CPU 211 determines that the interchangeable lens has been changed to another interchangeable lens (second interchangeable lens) in the power OFF state.

As described above, the CPU 211 can determine whether or not the interchangeable lens has been replaced by obtaining the interchangeable lens identification number from the lens controller 311 and comparing it with the previously stored interchangeable lens identification number. In particular, it is possible to detect whether or not the interchangeable lens 3 has been replaced during a period in which the digital camera 1 is in the power-off state by performing the replacement detection operation of the interchangeable lens immediately after the digital camera 1 is powered on. Can do.

3. Summary The digital camera 1 includes a CMOS sensor 201 that captures a subject image and generates image data, an optical filter 221 disposed between the optical system that forms the subject image and the CMOS sensor 201, and an optical filter 221. When the power of the piezoelectric element 222 and the drive circuit 223 that vibrates the optical filter 221 and the digital camera 1 are changed from OFF to ON in order to remove foreign matters attached on the surface, the dust reduction switch 224 is operated. And a CPU 211 that drives the piezoelectric element 222 and the drive circuit 223 using a shorter drive time than the case of the above.

As described above, in the digital camera, the vibration time of the optical filter when the power is turned on is made shorter than the vibration time when the dust reduction switch 224 is operated. As a result, it is possible to perform a dust removal operation in consideration of the start-up time, and it is possible to reduce that the user misses a photo opportunity.

4). Term Correspondence Relationship The digital camera 1 is an example of an imaging device. Note that the imaging apparatus may be only the camera body 2. The CMOS sensor 201 is an example of an image sensor. The optical filter 221 is an example of an optical element. The piezoelectric element 222 and the drive circuit 223 are an example of a vibration unit. The CPU 211 and the drive circuit 223 are examples of drive means. The CPU 211 is an example of a detection unit. The instruction from the outside is, for example, an instruction by the user. The instruction by the user may be, for example, a dedicated button provided on the digital camera 1 and an instruction using this dedicated button, or an image showing the removal operation on the liquid crystal monitor and using this image. However, it is not limited to these.

(Embodiment 2)
Embodiment 2 will be described. Since the configuration of the digital camera of the present embodiment has the same configuration as that of Embodiment 1, detailed description of the configuration is omitted.

1. Configuration The digital camera of the present embodiment is different from the first embodiment in the setting of the driving time in the vibration operation of the optical filter 221 when the power is turned on. FIG. 8 shows the setting of the vibration time of the optical filter 221 of the second embodiment.

As shown in FIG. 8, in the second embodiment, when the power is turned from OFF to ON, the CPU 211 of the camera body 2 indicates that the interchangeable lens 3 attached while the digital camera 1 is turned off is not the other. It is determined whether or not the lens has been replaced with an interchangeable lens. When the interchangeable lens 3 has been replaced, the optical filter 221 is vibrated with a vibration time of 400 msec. On the other hand, when the interchangeable lens has not been replaced, the optical filter 221 is vibrated at 200 msec, which is shorter than the vibration time when the interchangeable lens has been changed. This is because it is considered that dust is likely to enter the camera body from the opening of the camera body and adhere to the optical filter 221 by exchanging the lens. Here, instead of changing the vibration time according to whether or not the interchangeable lens is changed, the amplitude of vibration may be changed. Specifically, the vibration amplitude when the lens is changed is set to be larger than when the lens is not changed. The vibration amplitude can be changed by changing the magnitude of the applied voltage applied to the piezoelectric element 222.

As described above, the camera body makes the vibration time when the lens is not changed during the power OFF period shorter than the vibration time when the lens is changed. If the lens is not replaced during the power OFF period, it is considered that the dust accompanying the replacement of the interchangeable lens does not enter the camera body and the dust attached to the optical filter 221 is small. Therefore, even if the vibration time is shortened, sufficient dust removal is expected. Thus, when it is not necessary to remove dust, the vibration time can be shortened, and accordingly, power consumption can be reduced.

2. Operation The operation of the digital camera 1 configured as described above will be described with reference to the flowchart of FIG. Description of operations similar to those of the first embodiment is omitted.

When the power source of the camera body 2 is changed from OFF to ON (S1), the CPU 211 determines whether or not the interchangeable lens has been changed to another interchangeable lens when the power source is OFF (S21). When the interchangeable lens is changed to another interchangeable lens in the power OFF state, the CPU 211 controls the optical filter 221 to vibrate with a drive time of 400 msec (S22). On the other hand, when the interchangeable lens is not changed to another interchangeable lens in the power OFF state, the CPU 211 controls the optical filter 221 to vibrate with a vibration time of 200 msec (S23).

Since subsequent steps S3 to S8 are the same as steps S3 to S8 in the flowchart of FIG. 7 of the first embodiment, description thereof is omitted here.

3. Summary The second embodiment is a camera body 2 to which the interchangeable lens 3 can be attached and detached, and is disposed between the CMOS sensor 201 that captures a subject image and generates image data, and the interchangeable lens 3 and the CMOS sensor 201. In order to remove the optical filter 221 and the foreign matter adhering to the surface of the optical filter 221, the piezoelectric element 222 and the drive circuit 223 that vibrate the optical filter 221 and the power source of the main body are turned from OFF to ON. The CPU 211 that detects whether or not the interchangeable lens 3 has been attached / detached in the power-off state, and when the power source of the main body is turned from OFF to ON, the piezoelectric element 222 and the drive circuit are driven in the drive time based on the detection result of the CPU 211 CPU 211 for driving 223.

In this way, the camera body can adjust the drive time between when the lens is not changed and when the lens is changed when the power is OFF. Along with this, it is possible to efficiently remove foreign substances adhering to the optical filter while taking into account power consumption.

(Other embodiments)
Embodiments 1 and 2 have been exemplified as embodiments of the present invention. However, the embodiment of the present invention is not limited to the above embodiment. Other embodiments will be collectively described below.

In the first and second embodiments, a CMOS sensor is used as the image sensor. However, the image sensor is not limited to this, and for example, the image sensor may be a CCD image sensor. That is, the image sensor may have any configuration as long as it can capture a subject image and generate image data (digital signal or electric signal). In addition, when it comprises with a CMOS sensor, power consumption can be reduced more.

The value of the vibration time shown in FIGS. 3 and 8 of the first and second embodiments is an example.

In

Embodiments

1 and 2, the optical filter was vibrated by applying a voltage to the piezoelectric element. However, the present invention is not limited to this, and the optical filter can be vibrated by another actuator.

In the first and second embodiments, the configuration in which the piezoelectric element 222 is bonded to the optical filter 221 has been described, but the configuration is not limited thereto. For example, the transparent optical member may be vibrated by bonding a piezoelectric element to a transparent optical member different from the optical filter (LPF). In this case, an optical filter (LPF) is provided on the front surface of the image sensor, and a transparent optical member is provided on the front surface of the optical filter. This transparent optical member is a dedicated member provided to remove dust, and both surfaces may be provided with an antireflection coating or the like. When the optical filter is vibrated as in the first embodiment, the optical filter also serves to remove dust, so that the number of parts of the camera body can be reduced.

The shape of the optical filter may be a circle or a polygon such as a quadrangle.

The shape of the piezoelectric element may be an annular type or a strip type. Further, the number of piezoelectric elements is not limited to one, and a plurality of piezoelectric elements may be provided.

In the first embodiment, an example has been described in which the power of the apparatus is switched from OFF to ON in a state where the image sensor can generate image data. However, the present invention is not limited to this, and any case may be used as long as the imaging element changes from a state in which the imaging element cannot generate image data to a state in which the imaging element can generate image data. Therefore, for example, the case where the mode of the imaging apparatus is changed to “shooting mode” from the state where the mode is set to “playback mode” can be considered. That is, it is only necessary to change to a state in which the device can shoot.

In the second embodiment, in the power-off state of the digital camera 1, it is detected whether or not the interchangeable lens 3 has been changed to another interchangeable lens, and the drive time (vibration time) of the piezoelectric element 222 is determined according to the detection result. It was adjusted. However, the present invention is not limited to this configuration, and it may be detected whether or not the interchangeable lens is attached or detached in the power-off state, and the driving time of the piezoelectric element 222 may be adjusted according to the detection result. The attachment / detachment of the interchangeable lens means that the interchangeable lens is removed and attached. Whether or not the interchangeable lens has been attached or detached may be determined by detecting that the interchangeable lens has been removed from the camera body or by detecting that the interchangeable lens has been attached to the camera body. Also good.

In the second embodiment, when the power of the digital camera 1 is turned from OFF to ON, the driving time of the piezoelectric element 222 is adjusted according to whether or not the lens is exchanged. However, the present invention is not limited to this configuration, and the voltage applied to the piezoelectric element 222 may be adjusted according to the presence or absence of lens replacement. In this case, the CPU 211 may control the drive circuit 223 to drive the piezoelectric element 222 by increasing the applied voltage when lens replacement is detected, and decreasing the applied voltage when lens replacement is not detected. . In this way, when the lens is not exchanged, dust on the optical filter can be removed without unnecessary vibration, so that the power consumption of the camera body can be reduced. When adjusting the applied voltage, the driving time may not be changed or may be changed.

Further, the driving time of the dust removal operation may be changed according to the control mode (still image shooting mode, moving image shooting mode, playback mode, etc.) of the digital camera 1. For example, the driving time for the dust removal operation in the still image or moving image shooting mode may be longer than the driving time in the playback mode. This is because an image is not taken in the playback mode, and it is not necessary to remove dust that affects the image quality, so that a high dust removal function is not required.

In the first and second embodiments, the description has been given of the digital camera having no internal mirror. However, the first and second embodiments are also applied to the digital camera having the internal mirror (single-lens reflex type). It is possible to apply the idea disclosed in.

The first and second embodiments also disclose the concept of the imaging device of the following mode.
1) an image sensor that captures a subject image and generates image data;
An optical element disposed between the interchangeable lens and the imaging element;
Vibration means for vibrating the optical element;
Detecting means for detecting whether or not the interchangeable lens has been attached / detached when the power supply of the apparatus itself is turned from OFF to ON;
Voltage control means for driving the excitation means with the magnitude of the applied voltage based on the detection result of the detection means when the power supply of the device is turned on from OFF;
An imaging apparatus comprising:

2) an image sensor that captures a subject image and generates image data;
An optical element disposed between the optical system that forms the subject image and the imaging element;
Vibration means for vibrating the optical element in order to remove foreign matter adhering to the surface of the optical element;
A driving unit that drives the excitation unit using a driving time shorter than other timings when the image pickup device is set in a state capable of generating image data;
An imaging apparatus comprising:

3) an image sensor that captures a subject image and generates image data;
An optical element disposed between the optical system that forms the subject image and the imaging element;
Vibration means for vibrating the optical element in order to remove foreign matter adhering to the surface of the optical element;
When the optical element is controlled to be vibrated by a user's operation, driving means for driving the vibrating means using a driving time longer than other timings;
An imaging apparatus comprising:

4) an image sensor that captures a subject image and generates image data;
An optical element disposed between the optical system that forms the subject image and the imaging element;
Vibration means for vibrating the optical element in order to remove foreign matter adhering to the surface of the optical element;
When the apparatus is set in a state in which the image sensor can generate image data, while driving the excitation means using the first drive time,
A drive means for driving the vibration means using a second drive time when controlled to vibrate the optical element by a user's operation;
With
The first driving time is shorter than the second driving time,
Imaging device.

The present invention can be applied to an imaging apparatus such as a digital camera having a dust removing function, and a camera main body constituting such an imaging apparatus to which an interchangeable lens can be attached.

Although the present invention has been described with respect to particular embodiments, many other variations, modifications, and other uses will be apparent to those skilled in the art. Accordingly, the invention is not limited to the specific disclosure herein, but can be limited only by the scope of the appended claims.

Claims

An imaging apparatus including an interchangeable lens and a camera body,
An image sensor that captures a subject image and generates image data;
An optical element disposed between the optical system that forms the subject image and the imaging element;
Vibration means for vibrating the optical element;
Driving means for driving the excitation means,
The drive means drives the excitation means for a first drive time when the power supply of the apparatus is turned from OFF to ON, and receives an instruction for excitation from the outside of the imaging apparatus. Driving the excitation means during a second drive time;
The first driving time is shorter than the second driving time;
Imaging device.
When the power supply of the imaging device is turned from OFF to ON, the image pickup apparatus further includes detection means for detecting whether or not the interchangeable lens has been attached / detached when the power supply is OFF, and the first drive time is determined by the detection means. The imaging device according to claim 1, wherein the imaging device is determined according to a detection result.
When the power of the imaging device is turned from OFF to ON, the image pickup apparatus further includes detection means for detecting whether or not the interchangeable lens has been attached or detached when the power is turned off.
The drive means drives the excitation means for a drive time according to the detection result of the detection means when the power of the imaging device is turned on from OFF.
The imaging device according to claim 1.
A detection means for detecting whether or not the interchangeable lens has been replaced with another interchangeable lens in a state where the power of the imaging apparatus is OFF;
The drive means drives the excitation means for a drive time according to the detection result of the detection means when the power of the imaging device is turned on from OFF.
The imaging device according to claim 1.
It further comprises an operation means for receiving an instruction from the user,
The imaging apparatus according to claim 1, wherein the external vibration instruction is an instruction received via the operation unit.
An imaging apparatus including an interchangeable lens and a camera body,
An image sensor that captures a subject image and generates image data;
An optical element disposed between the optical system that forms the subject image and the imaging element;
Vibration means for vibrating the optical element;
Driving means for driving the excitation means,
The drive means drives the vibration means for a first drive time and reproduces an image taken in the control mode of the own apparatus when the control mode of the own apparatus is an imaging mode for taking an image. Driving the excitation means during the second drive time when in the playback mode;
The first driving time is longer than the second driving time;
Imaging device.
A camera body to which an interchangeable lens can be attached,
An image sensor that captures a subject image and generates image data;
An optical element disposed between the optical system that forms the subject image and the imaging element;
Vibration means for vibrating the optical element;
Driving means for driving the excitation means,
The drive means drives the excitation means during a first drive time when the power supply of the apparatus is turned from OFF to ON, and receives an instruction for excitation from the outside of the imaging apparatus. Driving the excitation means during a second drive time;
The first driving time is shorter than the second driving time;
The camera body.