WO2015056435A1

WO2015056435A1 - Imaging apparatus

Info

Publication number: WO2015056435A1
Application number: PCT/JP2014/005184
Authority: WO
Inventors: 鈴木　学; 万博池田
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2013-10-16
Filing date: 2014-10-10
Publication date: 2015-04-23

Abstract

　In a standby state in which a stepping motor (215) is turned off, a curtain unit (212) is positioned in an open position at which an aperture (211c) is opened. When an acceleration sensor (158) detects an acceleration equal to or greater than a prescribed value in the standby state, a camera controller (153) turns the stepping motor (215) on and holds the curtain unit (212) at the open position.

Description

Imaging device

The present disclosure relates to an imaging apparatus including a mechanical shutter.

Patent Document 1 discloses an imaging apparatus that realizes exposure by using both a mechanical shutter and an electronic shutter.

JP 2007-282128 A

This disclosure provides an imaging apparatus that can reduce malfunction of the curtain mechanism while suppressing an increase in the temperature of the actuator.

An imaging apparatus according to the present disclosure includes a cover having an opening, a curtain mechanism that is held by the cover and moves between a closed position that shields the opening and an open position that opens the opening, and the curtain mechanism. An actuator for driving, a control unit for controlling the actuator, and a sensor for detecting the acceleration of the own device, and the curtain mechanism is in the closed position or opened in the standby state in which the actuator is off. The control unit turns on the actuator when the sensor detects acceleration equal to or greater than a predetermined value in the standby state, and the control unit moves the curtain mechanism to the closed position corresponding to the standby state. Or hold in the open position.

The imaging device according to the present disclosure can reduce malfunction of the curtain mechanism while suppressing an increase in the temperature of the actuator.

It is an external view of a digital camera. It is a rear view of a digital camera. It is a block diagram which shows the structure of a digital camera. It is a front view of a mechanical shutter in a closed state. FIG. 5 is a cross-sectional view of the mechanical shutter taken along line AA in FIG. 4. It is a front view of the mechanical shutter of an open state. It is a schematic diagram of a long hole. It is a figure for demonstrating the example of control of a camera controller. It is a flowchart of standby control of a camera controller. It is a flowchart of exposure control of a camera controller. It is explanatory drawing of the excitation operation | movement of an actuator. It is explanatory drawing of the excitation control of an actuator. It is a flowchart for demonstrating control of the camera controller in other embodiment. It is a flowchart for demonstrating the example of control of the camera controller in another other embodiment.

Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

The inventor (s) provides the accompanying drawings and the following description in order for those skilled in the art to fully understand the present disclosure, and is intended to limit the subject matter described in the claims. Not what you want.

<1. Configuration>
<1-1. Outline of configuration>
An outline of the configuration of the digital camera 100 according to the exemplary embodiment will be described.

FIG. 1 is an external view of the digital camera 100. As shown in FIG. 1, the digital camera 100 includes an interchangeable lens 101 and a camera body 102 to which the interchangeable lens 101 can be attached. The camera body 102 includes a release button 160. When the camera body 102 receives a half-press operation by the user of the release button 160, the camera body 102 transmits a control signal to the interchangeable lens 101 so as to perform an autofocus operation. Further, when the camera body 102 receives an operation by the user of the release button 160, the camera body 102 performs a photographing operation of a subject image formed via the interchangeable lens 101. The digital camera 100 is an example of an imaging device.

FIG. 2 is a rear view of the digital camera 100 (camera body 102). The camera body 102 includes a liquid crystal monitor 163, a touch panel 162, a camera side operation unit 170 including a center button 204 and a cross button 205 on the back surface. The camera body 102 receives operations by the user of the touch panel 162 and the camera side operation unit 170, and performs various controls according to the operation contents.

FIG. 3 is a block diagram showing the configuration of the digital camera 100 (interchangeable lens 101 and camera body 102). The interchangeable lens 101 includes an optical system including a lens controller 120, a lens mount 130, a focus lens 110, and a zoom lens 112, a focus lens driving unit 111, a focus ring 114, a zoom lens driving unit 113, a zoom ring 115, an aperture 116, and an aperture drive. Unit 117, DRAM 121, flash memory 122, and the like. The camera body 102 includes a camera controller 153, a body mount 140, a CMOS image sensor 150, a timing generator 151, an analog front end 152, a liquid crystal monitor 163, a touch panel 162, a release button 160, a camera side operation unit 170, a power supply 154, a DRAM 155, and a flash. A memory 156, a mechanical shutter 157, an acceleration sensor 158, a card slot 165, a memory card 164, and the like are provided.

<1-2. Configuration of each part of interchangeable lens>
The configuration of each part of the interchangeable lens 101 will be described.

The lens system includes a focus lens 110 and a zoom lens 112, and collects light from the subject.

The zoom lens 112 is driven by a zoom lens driving unit 113. The zoom lens driving unit 113 drives the zoom lens 112 according to the operation of the zoom ring 115.

The focus lens 110 is driven by a focus lens driving unit 111. The focus lens driving unit 111 drives the focus lens 110 in response to an operation of the focus ring 114 or a control signal from the camera controller 153.

The diaphragm 116 adjusts the amount of light that passes through the lens system and enters the CMOS image sensor 150. The diaphragm 116 is driven by the diaphragm driver 117. The aperture driving unit 117 drives the aperture 116 in accordance with a control signal from the camera controller 153.

The lens controller 120 controls the entire interchangeable lens 101. The lens controller 120 may be realized by a processor such as a microcomputer or a hard-wired circuit. When the interchangeable lens 101 is attached to the camera body 102, the lens controller 120 reads out lens data stored in the flash memory 122 and transmits it to the camera controller 153.

<1-3. Configuration of camera body parts>
Next, the configuration of each part of the camera body 102 will be described.

The camera controller 153 controls the entire digital camera 100 such as the CMOS image sensor 150 in accordance with an instruction from the release button 160 or the camera side operation unit 170. The camera controller 153 transmits a vertical synchronization signal to the timing generator 151. In parallel with this, the camera controller 153 generates an exposure synchronization signal based on the vertical synchronization signal. The camera controller 153 periodically and repeatedly transmits the generated exposure synchronization signal to the lens controller 120 via the body mount 140 and the lens mount 130. The camera controller 153 is connected to the DRAM 155 and the flash memory 156, and can write and read information as necessary. The camera controller 153 may be configured with a hard-wired electronic circuit or a processor such as a microcomputer using a program. The camera controller 153 is an example of a control unit.

The DRAM 155 is used as a work memory for various controls by the camera controller 153. The flash memory 156 stores programs, parameters, and the like used for various controls by the camera controller 153.

The CMOS image sensor 150 captures a subject image incident through the interchangeable lens 101 and generates image information. The generated image information is converted from analog format data to digital format data by the AFE 152. The image information digitized by the AFE 152 is subjected to various image processing by the camera controller 153. Examples of the various types of image processing include gamma correction processing, white balance correction processing, scratch correction processing, YC conversion processing, electronic zoom processing, and JPEG compression processing, but are not limited thereto. Further, instead of the CMOS image sensor 150, for example, another imaging element such as an NMOS image sensor or a CCD image sensor may be used.

The CMOS image sensor 150 operates at a timing controlled by the timing generator 151. The operation of the CMOS image sensor 150 controlled by the timing generator 151 includes a still image capturing operation, a through image capturing operation, a data transfer operation, an electronic shutter operation, and an electronic front curtain operation. The through image is mainly a moving image and is displayed on the liquid crystal monitor 163 in order to determine a composition for capturing a still image.

The mechanical shutter 157 switches between blocking and passing light entering the CMOS image sensor 150 through the lens system. That is, the mechanical shutter 157 adjusts the amount of light hitting the CMOS image sensor 150 in terms of time. The mechanical shutter 157 is controlled by the camera controller 153. The mechanical shutter 157 is an example of a shutter mechanism. The detailed configuration of the mechanical shutter 157 will be described later.

The acceleration sensor 158 is a sensor that detects the acceleration of the camera body 102. The acceleration sensor 158 outputs the detected acceleration to the camera controller 153. The acceleration sensor 158 may be a triaxial acceleration sensor. The acceleration sensor 158 is an example of a sensor.

The body mount 140 is a connecting member that mechanically and electrically connects the interchangeable lens 101 and the camera body 102 together with the lens mount 130 included in the interchangeable lens 101. When the interchangeable lens 101 and the camera body 102 are mechanically and electrically connected, the lens controller 120 and the camera controller 153 are in a communicable state. The body mount 140 transmits the exposure synchronization signal and other control signals received from the camera controller 153 to the lens controller 120 via the lens mount 130. The body mount 140 transmits a signal received from the lens controller 120 via the lens mount 130 to the camera controller 153.

Release button 160 accepts user operations. The release button 160 is operated in two stages, half-press and full-press. When the user presses release button 160 halfway, camera controller 153 performs an autofocus operation. When the user fully presses the release button 160, the camera controller 153 performs shooting according to the full press operation, and stores the generated image information in the memory card 164.

The camera side operation unit 170 is a general term for operation members including the above-described center button 204 and cross button 205. The camera-side operation unit 170 includes a switch for switching between MF (Manual Focus) / AF (Autofocus). When the camera side operation unit 170 receives an operation by the user, the camera controller 153 executes various controls according to the operation instruction content.

<1-4. Configuration of Mechanical Shutter 157>
FIG. 4 is a front view of the mechanical shutter 157 in the closed state. FIG. 5 is a cross-sectional view of the mechanical shutter 157 taken along line AA in FIG. FIG. 6 is a front view of the mechanical shutter 157 in the open state.

¡Mechanical shutter 157 alternatively performs aperture opening and closing operations with a single curtain unit. For example, when the mechanical shutter 157 performs a shutter operation, it selectively functions as either the front curtain or the rear curtain. That is, the mechanical shutter 157 opens and closes the aperture 211c without forming a slit like a focal plane shutter having both a front curtain and a rear curtain. The mechanical shutter 157 includes a cover 211, a curtain unit 212, a drive arm 213, a driven arm 214, a stepping motor 215, a close detection switch 216, an open detection switch 217, and a snap action mechanism 218. . The curtain unit 212 includes a first blade 212a and a second blade 212b. The curtain unit 212 is an example of a curtain mechanism.

The cover 211 has a front cover 211a and a rear cover 211b, and has a plate-like shape as a whole. The cover 211 houses the first blade 212a, the second blade 212b, the drive arm 213, the driven arm 214, the close detection switch 216, and the open detection switch 217. The cover 211 is formed with a rectangular aperture 211c. Specifically, an aperture 211c is formed in both the front cover 211a and the rear cover 211b. The aperture 211 c has a size that does not block light that passes through the interchangeable lens 101 and enters the CMOS image sensor 150. The aperture 211c is formed in an approximately 2/3 region on the upper side in the vertical direction of the cover 211. That is, the aperture 211c is not provided in a substantially １／ area below the cover 211. The aperture 211c is an example of an opening.

Stepping motor 215 drives drive arm 213 to rotate. The stepping motor 215 is attached to the rear cover 211b at a position below the aperture 211c and shifted laterally from the aperture 211c. The stepping motor 215 is an example of an actuator.

The first blade 212a and the second blade 212b open and close the aperture 211c of the cover 211. The first blade 212a and the second blade 212b are substantially rectangular plate-shaped members. The first blade 212a and the second blade 212b are large enough to shield the aperture 211c in a state where they are aligned vertically with no gap between them. In a state where the first blade 212a and the second blade 212b are overlapped with each other, the aperture 211c is opened, and the first blade 212a and the second blade 212b are accommodated in an approximately 1/3 region below the cover 211.

One end of the drive arm 213 is attached to the rotating shaft of the stepping motor 215. That is, the drive arm 213 is rotationally driven by the stepping motor 215. A first blade 212 a is rotatably connected to the other end of the drive arm 213. The second blade 212b is rotatably connected to the intermediate portion of the drive arm 213.

One end of the driven arm 214 is rotatably connected to a portion of the rear cover 211b that is on the side of the aperture 211c and above the stepping motor 215. A first blade 212 a is rotatably connected to the other end of the driven arm 214. The second blade 212b is rotatably connected to the intermediate portion of the driven arm 214. The driven arm 214 is connected to the first blade 212a and the second blade 212b at a position above the drive arm 213.

Thus, the first blade 212a, the second blade 212b, the drive arm 213, and the driven arm 214 constitute a link mechanism. When the drive arm 213 is rotationally driven by the stepping motor 215, the first blade 212a, the second blade 212b, and the driven arm 214 move in conjunction with the rotation of the drive arm 213. The first blade 212a and the second blade 212b move between a closed position that shields the aperture 211c and an open position that opens the aperture 211c. In the closed position, the first blades 212a and the second blades 212b are lined up and down without any gap and completely shield the aperture 211c. In the open position, the first blade 212a and the second blade 212b overlap each other and are accommodated in the cover 211 to open the aperture 211c. Since the open position is located below the aperture 211c, the first blade 212a and the second blade 212b shield the aperture 211c from below to above. Regarding the rotational directions of the drive arm 213 and the driven arm 214, the direction in which the first blade 212a and the second blade 212b go to the open position is referred to as the open direction, and the direction in which the first blade 212a and the second blade 212b go to the closed position. Is referred to as the closing direction. The state where the first blade 212a and the second blade 212b are located at the open position is referred to as an open state, and the state where the first blade 212a and the second blade 212b are located at the closed position is referred to as a closed state.

The close detection switch 216 detects that the first blade 212a and the second blade 212b are in the closed position (closed state). Specifically, the driven arm 214 is provided with a protrusion 214c. And the close detection switch 216 is provided in the position which can detect the protrusion part 214c when the 1st blade | wing 212a and the 2nd blade | wing 212b are located in a closed position.

The open detection switch 217 detects that the first blade 212a and the second blade 212b are in the open position (open state). Specifically, the drive arm 213 is provided with a protrusion 213a. An open detection switch 217 is provided at a position where the protrusion 213a can be detected when the first blade 212a and the second blade 212b are in the open position.

For example, the close detection switch 216 and the open detection switch 217 are optical sensors (a photo interrupter or a photo reflector), and detect a closed state or an open state by blocking or reflecting light.

Thus, by driving the first blade 212a and the second blade 212b by the link mechanism and the stepping motor 215, the mechanical shutter 157 can be reduced in size and simplified. The stepping motor 215 may be replaced with an electromagnetic actuator such as a meter, a plunger or a DC motor, or an ultrasonic actuator.

The snap action mechanism 218 biases the driven arm 214 to maintain the first blade 212a and the second blade 212b in the open position when the first blade 212a and the second blade 212b are in the open position, When the first blade 212a and the second blade 212b are in the closed position, the driven arm 214 is urged so as to maintain the first blade 212a and the second blade 212b in the closed position. The snap action mechanism 218 includes a first engagement portion 211d provided on the rear cover 211b, a second engagement portion 214b provided on the driven arm 214, a first engagement portion 211d, and a second engagement portion 214b. And an urging spring 218a coupled to the. The rear cover 211b is formed with an arc-shaped long hole 211e through which the second engagement portion 214b passes when the driven arm 214 rotates.

The urging spring 218a is a torsion coil spring having a coiled part and two arms extending from the coiled part. One arm of the biasing spring 218a is held by the first engaging portion 211d, and the other arm of the biasing spring 218a is held by the second engaging portion 214b. In this state, the urging spring 218a is in a state where the coil-shaped portion is wound up, and generates an elastic force in a direction to separate the first engaging portion 211d and the second engaging portion 214b from each other. Yes. The biasing spring 218a is an example of a biasing portion.

The first engaging portion 211d is provided in the vicinity of the long hole 211e and on the opposite side of the long hole 211e from the rotation center of the driven arm 214.

In the snap action mechanism 218 configured as described above, when the first blade 212a and the second blade 212b move between the open position and the closed position, the second engagement portion 214b has an arc shape in the elongated hole 211e. Moving. FIG. 7 is a schematic diagram of the long hole 211e.

The total length of the long hole 211e corresponds to the moving range between the open position and the closed position of the first blade 212a and the second blade 212b. When the first blade 212a and the second blade 212b are positioned at the open position, the second engagement portion 214b is positioned at one end portion of the elongated hole 211e (hereinafter referred to as “open end portion”). When the second blade 212b is located at the closed position, the second engagement portion 214b is located at the other end portion (hereinafter referred to as “closed end portion”) of the long hole 211e. When the second engagement portion 214b is positioned in the first region S1 including the open end portion of the long hole 211e, the biasing spring 218a biases the second engagement portion 214b toward the open end portion. When the second engagement portion 214b is located in the second region S2 including the closed end portion of the long hole 211e, the biasing spring 218a biases the second engagement portion 214b toward the closed end portion. When the second engagement portion 214b is located in the third region S3 between the first region S1 and the second region S2 in the long hole 211e, the biasing spring 218a causes the second engagement portion 214b to open and No bias is applied to any of the closed ends.

Thus, the urging spring 218a switches the direction of the urging force between the first region S1 and the second region S2 with the third region S3 as a boundary. For example, considering that the first blade 212a and the second blade 212b move from the open position to the closed position, the second engagement portion 214b starts to move from the open end portion of the long hole 211e toward the closed end portion. At this time, the distance from the 2nd engaging part 214b to the 1st engaging part 211d becomes short gradually. Eventually, the second engagement portion 214b comes closest to the first engagement portion 211d in the third region S3 of the long hole 211e. Thereafter, as the second engaging portion 214b moves toward the closed end of the long hole 211e, the distance from the first engaging portion 211d gradually increases. Here, the urging spring 218a has a coiled portion wound up, and generates an elastic force in a direction in which the first engaging portion 211d and the second engaging portion 214b are separated from each other. That is, the urging spring 218a generates the largest elastic force when the first engagement portion 211d and the second engagement portion 214b are closest to each other. However, when the second engaging portion 214d is positioned in the third region S3 of the long hole 211e, the component of the elastic force in the circumferential direction of the long hole 211e is small, so the second engaging portion 214b is the open end portion. And the first blade 212a and the second blade 212b do not move to either the open position or the closed position. On the other hand, when the second engaging portion 214d is positioned in the first region S1 of the long hole 211e, the component of the elastic force in the circumferential direction of the long hole 211e increases, and the circumferential direction of the long hole 211e increases. Since the component is directed toward the open end, the second engagement portion 214b is urged toward the open end. That is, the first blade 212a and the second blade 212b are urged toward the open position. On the other hand, when the second engagement portion 214d is positioned in the second region S2 of the long hole 211e, the component in the circumferential direction of the long hole 211e is increased and the component in the circumferential direction is included in the elastic force. Since it faces toward the closed end, the second engagement portion 214b is urged toward the closed end. That is, the first blade 212a and the second blade 212b are urged toward the closed position. Thus, when the second engagement portion 214b is positioned in the first region S1 of the long hole 211e with reference to the time when the second engagement portion 214b is positioned in the third region S3 of the long hole 211e, the biasing spring 218a is The driven arm 214 is urged so that the second engagement portion 214b is moved toward the open end, that is, the first blade 212a and the second blade 212b are located at the open position. On the other hand, when the second engagement portion 214b is positioned in the second region S2 of the long hole 211e, the biasing spring 218a moves the second engagement portion 214b toward the closed end, that is, the first blade 212a and the second The driven arm 214 is urged so that the two blades 212b are located at the closed position.

That is, when the stepping motor 215 rotates the drive arm 213 to move the first blade 212a and the second blade 212b to the open position and the second engagement portion 214b moves to the first region S1 of the long hole 211e, The driven arm 214 is biased by the biasing spring 218a in the direction in which the first blade 212a and the second blade 212b move to the open position. On the other hand, when the stepping motor 215 rotates the drive arm 213 to move the first blade 212a and the second blade 212b to the closed position, and the second engagement portion 214b moves to the second region S2 of the long hole 211e, The driven arm 214 is biased by the biasing spring 218a in the direction in which the first blade 212a and the second blade 212b move to the closed position.

Even when the stepping motor 215 is off (during non-energization), since the driven arm 214 is urged by the urging spring 218a, the first blade 212a and the second blade 212b are in the open position or the closed position. Held in position. For example, when the digital camera 100 is in a standby state, the stepping motor 215 is off. When the digital camera 100 shifts to the standby state, the stepping motor 215 is turned off after the first blade 212a and the second blade 212b are moved to the open position. Even in such a case, the first blade 212a and the second blade 212b are held in the open position by the biasing force of the biasing spring 218a.

In the snap action mechanism 218, the urging force for the open position is weaker than the urging force for the closed position. Specifically, the urging force of the urging spring 218a is generally in the direction of a straight line connecting the first engaging portion 211d and the second engaging portion 214b. And the component of the circumferential direction of the long hole 211e of the urging | biasing force of the urging | biasing spring 218a urges | biases the 2nd engaging part 214b to an open end part or a closed end part. Therefore, the circumferential component of the long hole 211e differs depending on the posture of the biasing spring 218a. In this example, the component in the circumferential direction of the long hole 211e when the second engagement portion 214b is located at the closed end portion is the component of the long hole 211e when the second engagement portion 214b is located at the open end portion. The posture of the biasing spring 218a is set so as to be stronger than the component in the circumferential direction. Therefore, the urging force with respect to the open position of the snap action mechanism 218 is weaker than the urging force with respect to the closed position.

Also, when the first blade 212a and the second blade 212b are in the open position, the tip of the drive arm 213 contacts the lower edge 211f of the cover 211. That is, the lower end edge portion 211f of the cover 211 functions as a stopper. As shown in FIG. 5, the lower end edge portion of the rear cover 211b is bent so that the tip end portion of the drive arm 213 comes into contact therewith. When the stepping motor 215 positions the first blade 212a and the second blade 212b in the open position, the stepping motor 215 rotates the drive arm 213 to a position where the tip end portion of the drive arm 213 contacts the lower end edge portion 211f of the cover 211. In the standby state, the front end of the drive arm 213 is in contact with the lower end edge 211f of the cover 211 by the biasing force of the biasing spring 218a.

On the other hand, when the first blade 212a and the second blade 212b are in the open position, the tip of the driven arm 214 contacts the upper edge 211g of the cover 211. That is, the upper end edge 211g of the cover 211 functions as a stopper. As shown in FIG. 5, the upper edge of the rear cover 211b is bent so that the tip of the driven arm 214 comes into contact. When the stepping motor 215 positions the first blade 212a and the second blade 212b in the closed position, the drive arm 213 is rotated to a position where the tip of the driven arm 214 contacts the upper edge 211g of the cover 211.

<1-5. Actuator Configuration and Control of Mechanical Shutter 157>
In the mechanical shutter 157, as shown in FIG. 11, an actuator (for example, a stepping motor 215) is arranged in the center, and is arranged around a rotor (magnet) that is magnetized with two poles, and has an A phase and a B phase. And a stator on which a coil is wound.

Here, when the first blade 212 a and the second blade 212 b are in the open state, the mechanical shutter 157 has the drive arm 213 that has the lower edge of the cover 211 by the driving force of the stepping motor 215 and the biasing force of the biasing spring 218 a described above. It is pressed against the portion 211f (open side stopper). At this time, as shown in FIG. 11, the stepping motor 215 rotates in the same direction as the biasing direction of the biasing spring 218a by exciting the A-phase coil to the S pole and the B-phase coil to the S pole. Generate power. Thus, by controlling the excitation, the drive arm 213 can be more reliably pressed against the stopper, so that the operation when closing the mechanical shutter 157 can be performed with higher accuracy.

Further, when the first blade 212a and the second blade 212b are in the closed state, the mechanical shutter 157 has the driving arm 213 that has the upper edge of the cover 211 by the driving force of the stepping motor 215 and the biasing force of the biasing spring 218a. It is pressed against 211 g (closed side stopper). At this time, as shown in FIG. 11, the stepping motor 215 rotates in the same direction as the biasing direction of the biasing spring 218a by exciting the A-phase coil to the N pole and the B-phase coil to the S pole. Generate power. In this way, by performing excitation control, the driven arm 214 can be more reliably pressed against the stopper, so that the closed state of the first blade 212a and the second blade 212b can be reliably maintained.

For example, as shown in <TYPE 1> in FIG. 12, the mechanical shutter 157 can be operated by inputting an excitation control signal. Specifically, the stepping motor 215 presses the drive arm 213 against the stopper by exciting the A-phase coil to the S pole and the B-phase coil to the S pole, so that the first blade 212a and the second blade 212b is held open. Next, the stepping motor 215 excites the A-phase coil from the S-pole state in the order of S-pole and N-pole, and the B-phase coil from the S-pole state in the order of N-pole and N-pole. Thus, the first blade 212a and the second blade 212b are scanned in the closing direction. Finally, the stepping motor 215 presses the driven arm 214 against the stopper by exciting the A-phase coil to the N pole and the B-phase coil to the S pole, and thereby the first blade 212a and the second blade 212b. Is kept closed.

The mechanical shutter 157 can also be operated by inputting an excitation control signal as shown in <TYPE 2> in FIG. Specifically, the stepping motor 215 presses the drive arm 213 against the stopper by exciting the A-phase coil to the S pole and the B-phase coil to the S pole, so that the first blade 212a and the second blade 212b is held open. Next, the stepping motor 215 excites the A-phase coil from the S-pole state to the N-pole, and the B-phase coil from the S-pole state to the N-pole, whereby the first blade 212a and the first The two blades 212b are scanned in the closing direction. Finally, the stepping motor 215 presses the driven arm 214 against the stopper by exciting the A-phase coil to the N pole and the B-phase coil to the S pole, and thereby the first blade 212a and the second blade 212b. Is kept closed.

<2. Operation>
<2-1. Control by Camera Controller 153>
The camera controller 153 controls each unit as shown in FIG.

The camera controller 153 performs standby control when the power of the camera body 102 is turned on by the user. The camera controller 153 displays the image data obtained by the CMOS image sensor 150 on the liquid crystal monitor 163 as a through image in standby control. The camera controller 153 performs standby control. Details of the standby control will be described later.

The camera controller 153 performs exposure control when the release button 160 is fully pressed (turned on) by the user. The camera controller 153 realizes an electronic front curtain by controlling the CMOS image sensor 150 and the mechanical shutter 157 in exposure control. The camera controller 153 reads out image data (still image) while the aperture 211c is shielded by the first blade 212a and the second blade 212b of the mechanical shutter 157. When reading of the image data is completed, the camera controller 153 moves the first blade 212a and the second blade 212b to the open position. Details of the exposure control will be described later.

When the photographing is completed, the camera controller 153 returns to standby control.

Thereafter, when the power of the camera body 102 is turned off by the user, the camera controller 153 stops the power supply to each part of the camera body 102.

<2-2. Exposure control>
First, exposure control by the camera controller 153 will be described. The camera controller 153 controls the CMOS image sensor 150 and executes an electronic shutter as a front curtain. Thereafter, the camera controller 153 controls the mechanical shutter 157 to function as a rear curtain. Thereby, the imaging operation is executed.

Here, the camera controller 153 performs the following adjustment in order to make the locus of the electronic shutter as the front curtain more approximate to the locus of the mechanical shutter 157 as the rear curtain.

(1) Adjust the speed of the scanning pattern of the electronic shutter, which is the front curtain, for each line. For example, the scanning speed to the next line is gradually increased from the start line to the end line. This is because the speed of the mechanical shutter 157 gradually increases at the beginning and end of closing.

(2) Adjust the scanning pattern of the electronic shutter, which is the front curtain, according to the temperature of the device itself. This is because when the temperature of the actuator (stepping motor 215) is high, the torque of the actuator decreases and the speed of the mechanical shutter 157 decreases as a whole. Specifically, when the temperature of the coil of the stepping motor 215 increases, the resistance increases and the current value decreases. For this reason, the torque decreases as the current value decreases. Further, when the temperature of the magnet of the stepping motor increases, the magnetic force decreases. As a result, the torque is reduced due to the drop of the magnetic force.

Specific processing will be described with reference to the flowchart shown in FIG.

When the release is turned on (the release button 160 is fully pressed), the camera controller 153 scans the electronic shutter in consideration of the temperature of the device itself (any of the digital camera 100, the mechanical shutter 157, and the stepping motor 215). The pattern is adjusted and the electronic shutter is controlled for the CMOS image sensor 150 (T1).

Then, the camera controller 153 turns on the excitation of the stepping motor 215 and presses the drive arm 213 against the stopper (the lower end edge 211f of the cover 211) (T2). This is to make the drive control of the mechanical shutter 157 more accurate.

Thereafter, the camera controller 153 waits for the shutter speed time after the electronic shutter is started (T3), and moves the first blade 212a and the second blade 212b of the mechanical shutter 157 in the closing direction (T4).

Then, the camera controller 153 turns on the excitation of the stepping motor 215 and presses the driven arm 214 against the stopper (the upper edge 211g of the cover 211) (T5). This is to make the shielding of the mechanical shutter 157 more reliable.

Thereafter, the camera controller 153 reads out still image data from the CMOS image sensor 150 (T6).

When the reading is completed, the camera controller 153 moves the first blade 212a and the second blade 212b in the opening direction (T7).

<2-3. Standby control>
Next, standby control will be described with reference to FIG. As described in the exposure control, when the temperature of the stepping motor 215 rises, it is necessary to adjust the scanning pattern of the electronic shutter. Therefore, in standby control, control is performed to turn off the excitation of the stepping motor 215 as much as possible. On the other hand, when the excitation of the stepping motor 215 is turned off, the mechanical shutter 157 moves from the position where the first blade 212a and the second blade 212b should be positioned in the standby state when an impact is applied to the camera body 102. There is a fear.

Furthermore, in the mechanical shutter 157, the first blade 212a and the second blade 212b are biased to either the open position or the closed position by the snap action mechanism 218. Therefore, as long as the impact is small, the biasing force of the biasing spring 218a holds the first blade 212a and the second blade 212b in the open position and the closed position that should be positioned in the standby state. However, while the snap action mechanism 218 can hold the first blade 212a and the second blade 212b, as described above, the direction of the urging force is switched with the reference position as a boundary. Therefore, the impact is great, the first blade 212a and the second blade 212b move against the biasing force of the biasing spring 218a, and the first blade 212a and the second blade 212b move in the direction of the biasing force of the biasing spring 218a. When the first blade 212a and the second blade 212b have moved to the position where the first and second blades are switched, the biasing force of the biasing spring 218a is opposite to the position corresponding to the standby state among the open position and the closed position. It will be moved to the position.

In particular, the urging force of the urging spring 218a toward the open position is weaker than the urging force toward the closed position. Therefore, when the shock is applied from the open position to the closed position rather than from the closed position to the open position. The first blade 212a and the second blade 212b are easy to move. In this example, since the positions of the first blade 212a and the second blade 212b in the standby state are set to the open position, compared to the case where the first blade 212a and the second blade 212b are positioned to the closed position, When an impact is applied, the first blade 212a and the second blade 212b are easily moved to opposite positions.

Therefore, the camera controller 153 performs standby control as follows.

The camera controller 153 turns off the excitation for the stepping motor 215 when it enters standby control (S1). Thereby, power consumption is reduced and the temperature rise of the stepping motor 215 is suppressed. This is the normal standby state.

Thereafter, the camera controller 153 determines whether or not the output of the acceleration sensor 158 is equal to or greater than a predetermined value (S2). When the output of the acceleration sensor 158 is not equal to or greater than the predetermined value, the camera controller 153 continues turning off the excitation for the stepping motor 215. That is, the camera controller 153 monitors whether or not the acceleration acting on the camera body 102 is equal to or higher than the predetermined acceleration, and continues the inoperative state of the stepping mode 215 as long as the acceleration is less than the predetermined acceleration.

On the other hand, when the output of the acceleration sensor 158 exceeds a predetermined value, the camera controller 153 turns on the excitation for the stepping motor 215 (S3). Specifically, the camera controller 153 holds the first blade 212a and the second blade 212b in the open position, i.e., presses the driving arm 213 against the stopper (the lower end edge 211f of the cover 211). Supply current.

Then, the camera controller 153 waits for a predetermined time with the excitation for the stepping motor 215 turned on (S4). When the predetermined time has elapsed, the camera controller 153 returns to step S1, turns off the excitation for the stepping motor 215, and returns to the normal standby state.

<3. Effect>
As described above, the digital camera 100 includes the cover 211 having the aperture 211c, the curtain unit 212 that is held by the cover 211 and moves between the closed position that shields the aperture 211c and the open position that opens the aperture 211c, and the curtain. In a standby state in which a stepping motor 215 that drives the unit 212, a camera controller 153 that controls the stepping motor 215, and an acceleration sensor 158 that detects the acceleration of the camera body 102 are provided and the stepping motor 215 is off. The curtain unit 212 is located at the closed position or the open position, and the camera controller 153 turns on the stepping motor 215 when the acceleration sensor 158 detects an acceleration of a predetermined value or more in the standby state, and the curtain unit 212 is turned on. On standby Held in the closed position or the open position to respond.

This makes it possible to reduce the malfunction of the mechanical shutter 157, that is, the curtain unit 212, while suppressing the temperature rise of the stepping motor 215.

The digital camera 100 further includes a biasing spring 218a that biases the curtain unit 212 toward the closed position and the open position. The curtain unit 212 receives the biasing force of the biasing spring 218a in the standby state. In the state, it is located at the closed position or the open position corresponding to the standby state.

That is, in the standby state, the curtain unit 212 is basically held in either the closed position or the open position by the biasing spring 218a.

Further, the urging spring 218a urges the curtain unit 212 to the open position in the predetermined first area S1 including the open position in the movement range between the closed position and the open position of the curtain unit 212, while moving. In the predetermined second region S2 in the range including the closed position, the curtain unit is biased to the closed position.

That is, the biasing spring 218a is configured to switch the biasing direction within the movement range between the closed position and the open position of the curtain unit 212. Thus, the urging in the closing direction and the urging in the opening direction of the curtain unit 212 can be realized by one urging spring 218a. Further, in the urging spring 218a in which the urging direction is switched in this way, the curtain unit 212 should be originally positioned when the urging direction of the urging spring 218a is switched by the impact force. It easily moves to a position opposite to the position. Therefore, the above-described standby control is particularly effective.

Specifically, the biasing spring 218a switches the direction in which the curtain unit 212 is biased with respect to the third region S3 between the first region S1 and the second region S2 in the movement range.

In the digital camera 100, when the curtain unit 212 is open, the driving arm 213 is pressed against the stopper by the biasing force of the biasing spring 218a, and the driving arm 213 is further pressed against the stopper by the excitation of the stepping motor 215. .

Thereby, the drive arm 213 can be reliably pressed by the stopper. Therefore, since the positioning of the curtain unit 212 in the open state can be performed accurately, the operation for moving the curtain unit 212 to the closed position can be performed with higher accuracy.

Further, in the digital camera 100, the driven arm 214 is pressed against the stopper by the biasing force of the biasing spring 218a in the closed state of the curtain unit 212, and the driven arm 214 is further pressed against the stopper by excitation of the stepping motor 215. .

Thereby, the shielding state of the aperture 211c by the curtain unit 212 can be more reliably maintained.

(Additional notes on other features)
A cover having an opening and having a closing stopper and an opening stopper which are mechanical ends;
A curtain mechanism that is held by the cover so as to move between a position that contacts the closing stopper and shields the opening, and a position that contacts the opening stopper and does not shield (open) the opening; ,
An actuator for driving the curtain mechanism;
A control unit for controlling the actuator,
The curtain mechanism is based on a predetermined boundary between the shielding position and the non-shielding position,
When present on the shielding position side, it is urged by the first urging force to the shielding position,
When present on the non-shielding position side, the second biasing force is applied to the shielding position,
The actuator is
In a state where the curtain mechanism is in contact with the closing stopper by the first urging force, power is generated to further press the curtain mechanism against the closing stopper,
An imaging apparatus that generates power for further pressing the curtain mechanism against the opening stopper in a state where the curtain mechanism is in contact with the opening stopper by a second urging force.

<< Other Embodiments >>
As described above, the first embodiment has been described as an example of the technique disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed.

Therefore, other embodiments will be exemplified below.

The configuration of the digital camera 100 is merely an example, and is not limited to the above configuration. For example, the digital camera 100 includes the camera body 102 and the interchangeable lens 101 that can be attached to the camera body 102, but the camera body 102 and the lens 101 may not be removable.

In the above description, an example using the acceleration sensor 158 has been described. However, an impact sensor may be used instead of the acceleration sensor 158. In this case, the camera controller 153 may turn on the excitation of the stepping motor 215 when detecting an impact (impact force) of a predetermined value or more in the standby control. The acceleration sensor 158 may be a sensor that can detect the movement of the camera body 102 per unit time.

In addition, in the said embodiment, although the acceleration sensor 158 does not limit the direction of detected acceleration, you may limit the direction of acceleration. For example, the acceleration sensor 158 is configured to detect a direction corresponding to the moving direction of the curtain unit 212, that is, a vertical direction acceleration, and the camera controller 153 performs the standby control based on the vertical direction acceleration. It may be. Further, the acceleration sensor 158 may detect an acceleration of three orthogonal axes. In that case, the camera controller 153 may perform standby control based on the acceleration in the direction close to the moving direction of the curtain unit 212 among the accelerations in the three directions, or the acceleration in the moving direction of the curtain unit 212 from the acceleration in the three directions. The standby control may be performed based on the calculated acceleration.

The mechanical shutter 157 is not provided with a lock mechanism for the curtain unit 212. However, the mechanical shutter 157 may employ a mechanical lock mechanism (hereinafter referred to as a mechanical lock) that restricts the movement of the curtain unit 212 in the open position and / or the closed position. In this case, as shown in the flowchart of FIG. 13, the camera controller 153 controls the mechanical shutter 157. When the power of the camera body 102 is turned off by the user, the camera controller 153 turns on (locks) the mechanical lock of the curtain unit 212 (S11), and then turns off the power of the camera body 102 (S12). Thereafter, when the power of the camera body 102 is turned on by the user, the camera controller 153 turns off the power of the camera body 102 (S13) and then turns off (unlocks) the mechanical lock of the curtain unit 212 ( S14). In this way, it is possible to prevent the curtain unit 212 of the mechanical shutter 157 from moving erroneously while the camera body 102 is powered off (for example, from the open state to the closed state).

As another example employing the lock mechanism, as shown in the flowchart of FIG. 14, the camera controller 153 may hold the state in which the mechanical lock is turned on until the release is turned on. Specifically, the camera controller 153 turns off the mechanical lock (S22) when the release is turned on while the mechanical lock is on (S21). Then, the camera controller 153 performs an imaging operation using the curtain unit 212 of the mechanical shutter 157. Thereafter, the camera controller 153 moves the curtain unit 212 of the mechanical shutter 157 to the open position (S23), and turns on the mechanical lock when the curtain unit 212 moves to the closed position (S24). In this way, it is possible to prevent the curtain unit 212 of the mechanical shutter 157 from moving erroneously (for example, from the open state to the closed state) while the camera body 102 is powered off and during the release standby. be able to.

In the above description, the position of the curtain unit 212 in the standby state is set to the open position, but the position of the curtain unit 212 in the standby state may be set to the closed position.

Further, the lower end edge 211f and the upper end edge 211g of the cover 211 form a stopper, but the configuration of the stopper is not limited to this. When the curtain unit 212 is in an open state or a closed state, the curtain unit 212 is physically brought into contact with any one of the first blade 212a, the second blade 212b, the drive arm 213, and the driven arm 214 to restrict the movement of the curtain unit 212. If there is, a stopper having an arbitrary configuration can be adopted.

Further, the camera controller 153 operates the stepping motor 215 so as to press the drive arm 213 against the stopper when an acceleration equal to or higher than a predetermined acceleration is detected in the standby control, but the stepping motor 215 in the standby control. This control is not limited to this. For example, in the standby control, the camera controller 153 supplies current to the stepping motor 215 so that the first blade 212a and the second blade 212b are positioned at the open position when acceleration equal to or higher than a predetermined acceleration is detected. May be. That is, in the above description, in order to press the drive arm 213 against the stopper, the stepping motor 215 supplies a current that causes the first blade 212a and the second blade 212b to move further in the opening direction than the open position. Yes. However, since the stepping motor 215 can hold the first blade 212a and the second blade 212b in the open position without cooperation with the stopper, the camera controller 153 opens the first blade 212a and the second blade 212b. A current sufficient to be positioned may be supplied to the stepping motor 215. However, it does not exclude that the drive arm 213 contacts the stopper when the first blade 212a and the second blade 212b are held in the open position.

The snap action mechanism 218 uses one biasing spring 218a to realize the biasing in the opening direction and the biasing in the closing direction of the first blade 212a and the second blade 212b, but is limited to this configuration. It is not a thing. For example, the snap action mechanism 218 includes two springs: a spring that biases the first blade 212a and the second blade 212b in the opening direction and a spring that biases the first blade 212a and the second blade 212b in the closing direction. You may have.

The actuator is not limited to the stepping motor 215. The actuator may be another motor such as a DC motor. However, since the stepping motor 215 can hold the drive arm 213 in a desired position, the stepping motor 215 is preferable when the curtain unit 212 is held as a single actuator (that is, not in cooperation with the stopper).

As described above, the embodiments have been described as examples of the technology in the present disclosure. For this purpose, the accompanying drawings and detailed description are provided.

Accordingly, among the components described in the accompanying drawings and the detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to illustrate the above technique. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

In addition, since the above-described embodiments are for illustrating the technique in the present disclosure, various modifications, replacements, additions, omissions, and the like can be made within the scope of the claims and the equivalents thereof.

The present disclosure can be applied to an imaging apparatus including a mechanical shutter such as a digital camera, a movie, or a mirrorless.

DESCRIPTION OF SYMBOLS 100 Digital camera 101 Interchangeable lens 102 Camera body 110 Focus lens 111 Focus lens drive part 112 Zoom lens 113 Zoom lens drive part 114 Focus ring 115 Zoom ring 116 Diaphragm 117 Diaphragm drive part 120 Lens controller 121 DRAM
122 Flash memory 130 Lens mount 140 Body mount 150 CMOS image sensor 151 Timing generator 152 Analog front end 153 Camera controller 154 Power supply 155 DRAM
156 Flash memory 157 Mechanical shutter 158 Acceleration sensor 160 Release button 162 Touch panel 163 LCD monitor 164 Memory card 165 Card slot 170 Camera side operation unit 204 Center button 205 Cross button

Claims

A cover having an opening;
A curtain mechanism that is held by the cover and moves between a closed position that shields the opening and an open position that opens the opening;
An actuator for driving the curtain mechanism;
A control unit for controlling the actuator;
A sensor that detects the acceleration of the device itself,
The curtain mechanism is located at the closed position or the open position in a standby state in which the actuator is off,
The controller turns on the actuator to hold the curtain mechanism in the closed position or the open position corresponding to the standby state when the sensor detects an acceleration of a predetermined value or more in the standby state. Imaging device.
The imaging device according to claim 1,
An urging portion that urges the curtain mechanism toward each of the closed position and the open position;
In the standby state, the curtain mechanism is located at the closed position or the open position corresponding to the standby state in a state of receiving the biasing force of the biasing unit.
The imaging device according to claim 2,
The urging unit urges the curtain mechanism to the open position in a predetermined first region including the open position in a movement range between the closed position and the open position of the curtain mechanism. An imaging apparatus that urges the curtain mechanism to the closed position in a predetermined second area including the closed position in the movement range.
The imaging device according to claim 3.
The urging unit is an imaging apparatus in which a direction in which the curtain mechanism is urged is switched with a third region between the first region and the second region as a boundary in the movement range.
A cover having an opening;
A curtain mechanism that is held by the cover and moves between a closed position that shields the opening and an open position that opens the opening;
An actuator for driving the curtain mechanism;
A lock mechanism for restricting movement of the curtain mechanism;
A controller for controlling the actuator and the lock mechanism,
The control unit operates the lock mechanism to restrict the movement of the curtain mechanism when shifting to a standby state in which the actuator is turned off.