JP2016061799A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a release time lag in silent photography.SOLUTION: When a first mirror driving mode is set, a motor drives a charge member in a first driving direction. When a second mirror driving mode is set, the motor drives the charge member in a second driving direction opposite to the first driving direction. When the second mirror driving mode is set, the motor is driven in the second driving direction, so as to drive the charge member up to a position just before a mirror driving member starts to move to a mirror-up position, when a first signal is outputted and the motor is driven in the second driving direction, so as to drive the charge member from the position just before, when a second signal is outputted.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an imaging apparatus having a mirror movable with respect to an optical path.

  In a single-lens reflex camera, the mirror is advanced and retracted with respect to the optical path from the imaging optical system (imaging optical path).

  In order to shorten the finder disappearance time due to the mirror up operation accompanying imaging, and to increase the continuous shooting frame speed, it is necessary to drive the mirror at high speed. However, when the mirror is driven at a high speed, the mirror collides with a positioning member provided at the mirror up position and the mirror down position with a large force, and a large collision sound is generated.

  In a single-lens reflex camera, various proposals have been made to reduce the sound generated when the mirror is driven.

  Patent Document 1 discloses that the driving speed of a mirror is switched by switching the driving direction of a motor between a first direction (forward rotation direction) and a second direction (reverse rotation direction). In the technique disclosed in Patent Document 1, silent shooting with relatively low mirror operation sound is possible by driving the motor in the second direction (reverse direction).

JP 2008-175920 A

  However, in the technique disclosed in Patent Document 1, when performing silent shooting, the mirror actually moves after the cam top or cam bottom runs idle before the mirror moves. This idle running distance is a distance corresponding to an overrun after the motor is braked when the motor is driven in the first direction (forward rotation direction).

  That is, when the motor is driven in the second direction (reverse direction), the release time lag is the sum of the idle running time and the mirror driving time. Since the idle time is not directly related to the operation of the mirror, the release time lag becomes longer by the idle time.

  In view of the above problems, an object of the present invention is to reduce a release time lag during silent shooting.

  In order to achieve the above object, an imaging apparatus of the present invention includes a mirror, a mirror driving member that drives the mirror between a mirror up position and a mirror down position, and a biasing member that biases the mirror driving member. And a charge member for driving the mirror drive member against the urging force of the urging member to charge the urging member, a motor for driving the charge member, and outputting the first signal by half-pressing And a release button for outputting the second signal when fully pressed, and a setting means capable of setting the first mirror driving mode or the second mirror driving mode, wherein the first mirror driving mode is When set, the motor drives the charge member in the first drive direction, and when the second mirror drive mode is set, the motor drives the charge member to the first drive direction. When driving in the second driving direction opposite to the moving direction and the second mirror driving mode is set, when the first signal is output, the mirror driving member is moved to the mirror up position. When the motor is driven in the second drive direction so that the charge member is driven to a position immediately before starting the movement to the position, and the second signal is output, the charge is started from the immediately previous position. The motor is driven in the second driving direction so as to drive a member.

  According to the present invention, the release time lag at the time of silent shooting can be shortened.

1 is a central cross-sectional view of a digital single lens reflex camera main body and an interchangeable lens as an imaging apparatus according to an embodiment of the present invention. 1 is a perspective view of a digital single-lens reflex camera main body and an interchangeable lens as an imaging apparatus according to an embodiment of the present invention. It is a disassembled perspective view of a shutter unit. It is the top view and perspective view which show the principal part of a shutter unit. It is a side view which shows the principal part of a shutter unit. It is a partial enlarged view of a shutter unit. It is the figure which showed the cam diagram of a cam gear, the control voltage of a motor, and the operation | movement of the mechanism in each phase. FIG. 6 is a plan view showing a moment of releasing tension in a normal mode of the shutter unit. It is a top view showing the state in which the blade | wing return was completed in the normal mode of a shutter unit, and the bound lock operation | movement is effective. FIG. 6 is a plan view showing a state in which the cam gear 4 is at the end of the bound lock phase after the mirror up operation is completed in the normal mode of the shutter unit. It is a top view showing the standby state before driving in the normal mode of the shutter unit. It is a top view which shows the state which the driving | running | working operation was completed in the normal mode of a shutter unit. It is a top view showing the completion state of the mirror charge operation in the normal mode of the shutter unit. It is a top view showing the completion state of the bound lock setting operation | movement in the normal mode of a shutter unit. FIG. 10 is a plan view showing a state where the tightening setting operation is completed in the normal mode of the shutter unit. It is a top view showing the moment of tension release in silent mode of a shutter unit. It is a top view showing the state in which the blade | wing return was completed and the bound lock operation | movement is effective in the silent mode of a shutter unit. It is a top view showing the start state of the bound lock release operation | movement in silent mode of a shutter unit. It is a top view showing the completion state of the bound lock release operation | movement in silent mode of a shutter unit. It is a top view showing the start state of the mirror up operation | movement in the silent mode of a shutter unit. It is a top view showing the state which the mirror up operation | movement in silent mode of a shutter unit was completed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a central cross-sectional view of a digital single lens reflex camera body (hereinafter referred to as a camera) 1 and an interchangeable lens 5 as an imaging apparatus according to an embodiment of the present invention, and FIG. 2 is a perspective view of the camera 1 and the interchangeable lens 5. It is.

  The interchangeable lens 5 is detachably fixed to the camera 1 by a mount portion 11 on the camera 1 side and a mount portion 51 on the interchangeable lens 5 side. When the interchangeable lens 5 is attached to the camera 1, the contact portion 12 of the camera 1 and the contact portion 52 of the interchangeable lens 5 are electrically connected. Thereby, the camera 1 detects that the interchangeable lens 5 is attached. Further, power supply from the camera 1 to the interchangeable lens 5 and communication for controlling the interchangeable lens 5 are performed via the contact portions 12 and 52.

  The light beam that has passed through the focus lens 53 of the interchangeable lens 5 enters the main mirror 13 of the camera 1. The main mirror 13 is held by a main mirror holding frame 131 and is pivotally supported by a rotary shaft 131a so as to be rotatable between a mirror up position (first position) and a mirror down position (second position). Yes.

  The main mirror 13 is a half mirror, and the light beam transmitted through the main mirror 13 is reflected downward by the sub mirror 14 and guided to the focus detection unit 15.

  The sub mirror 14 is held by the sub mirror holding frame 141. The sub mirror holding frame 141 is pivotally supported with respect to the main mirror holding frame 131 by a hinge shaft (not shown).

  The focus detection unit 15 detects the defocus amount of the focus lens 53 and calculates the drive amount of the focus lens 53 that brings the focus lens 53 into a focused state. The interchangeable lens 5 receives the calculated driving amount via the contact parts 12 and 52. The interchangeable lens 5 controls the motor (not shown) based on the received drive amount, and performs focus adjustment by driving the focus lens 53.

  The light beam reflected by the main mirror 13 is guided to the optical viewfinder 16. The optical viewfinder 16 includes a focus plate 17, a pentaprism 18, and an eyepiece lens 19. The light beam guided to the optical finder 16 by the main mirror 13 forms a subject image on the focus plate 17. The user can observe the subject image on the focusing screen 17 via the pentaprism 18 and the eyepiece lens 19.

  A shutter unit 20 is disposed behind the sub mirror 14. Behind the shutter unit 20, an optical low-pass filter 21, an image sensor holder 22, an image sensor 23, a cover member 24, and a rubber member 25 are disposed. At the time of shooting, the light beam that has passed through the optical low-pass filter 21 enters the image sensor 23. The image sensor holder 22 is fixed to the housing of the camera 1 with screws (not shown). The image sensor 23 is held by an image sensor holder 22. The cover member 24 protects the image sensor 23. The rubber member 25 holds the optical low-pass filter 21 and seals between the optical low-pass filter 21 and the image sensor 23.

  The display monitor 26 is a monitor composed of an LCD (liquid crystal display) or the like, and displays a captured image and various setting states of the camera 1.

  The release button 31 is a release button that is a two-stage switch. The state where the release button 31 is pushed down to the first level is called a half-pressed state, and the signal SW1 (first signal) is generated in this half-pressed state. When the signal SW1 is generated, photometry and focus detection are performed. When the release button 31 is further pressed from the half-pressed state, the release button 31 is fully pressed down to the second level. The signal SW2 (second signal) is generated in the fully pressed state. When the signal SW2 is generated, the shutter unit 20 is driven and photographing is performed. The mode dial (setting means) 32 is a dial that can be rotated. In the camera 1 of the present embodiment, the mirror drive mode is switched to “normal mode”, “silent mode A”, or “silent mode B” depending on the rotational position of the mode dial 32.

  FIG. 3 is an exploded perspective view of the shutter unit 20 and the main mirror 13.

  The shutter base plate 201 is fixed to a mirror box (not shown) in the camera 1, and each component constituting the drive mechanism of the trailing blade group (blade member) 212 is attached. The shutter base plate 201 has an opening (exposure opening) 201e through which a subject light flux passes. The opening 201e is closed when the trailing blade group 212 is deployed, and the opening 201e is opened when the trailing blade group 212 is superimposed. The trailing blade group 212 is normally closed.

  The mirror drive lever (mirror drive member) 202 is supported so as to be rotatable about the shaft portion 203 a of the MG main plate 203. A contact portion 202 a formed on the mirror drive lever 202 contacts a shaft portion 131 b that is a driven portion of the main mirror holding frame 131. The main mirror holding frame 131 is biased by a spring (not shown) so as to follow the movement of the mirror drive lever 202.

  The cam gear (charge member) 204 is supported so as to be rotatable about a shaft 201 b formed on the shutter base plate 201.

  The rear curtain drive lever (drive member) 205 is supported so as to be rotatable about a shaft 201 a formed on the shutter base plate 201. The rear curtain drive lever 205 is formed with a cylindrical portion 205a, and a blade lever (blade moving member) 206 is rotatably supported by the cylindrical portion 205a. The blade lever 206 rotates between a closed position where the trailing blade group 212 closes the opening 201e and an open position where the trailing blade group 212 opens the opening 201e.

  The tension lever (locking member) 207 is supported so as to be rotatable about a shaft 201 c formed on the shutter base plate 201. A cam follower 207 a provided on the tension lever 207 abuts on a tension cam 204 c provided on the cam gear 204. When the cam gear 204 rotates, the cam follower 207a traces the tension cam 204c, and the tension lever 207 swings.

  The bound lock lever (regulating member) 208 is supported so as to be rotatable about a shaft 201 d formed on the shutter base plate 201. When the tightening lever 207 presses the roller 208a provided on the bound lock lever 208, the bound lock lever 208 rotates. The bound lock lever 208 moves between a restriction position that restricts the movement of the blade lever 206 and a release position that releases the movement restriction of the blade lever 206.

  The armature 209 is provided on the rear curtain drive lever 205, and the electromagnet 210 is provided on the MG base plate 203. As shown in FIG. 6A, the electromagnet 210 includes a yoke 210a and a coil 210b provided on the outer periphery of the yoke 210a. When a voltage is applied to the coil 210b, a magnetic force is generated in the yoke 210a, and the armature 209 can be attracted by this magnetic force.

  The motor 211 is attached to the shutter base plate 201. The driving force of the motor 211 is transmitted to the cam gear 204 via the gear train 213 disposed on the back side of the shutter base plate 201, and the cam gear 204 rotates. By this rotation, the mirror drive lever 202, the rear curtain drive lever 205, the blade lever 206, the tension lever 207, and the bound lock lever 208 are rotated, and the main mirror 13 is rotated and the rear curtain blade group 212 is reciprocated. The action can be performed. The motor 211 is provided with terminals 211a and 211b. The driving direction of the motor 211 can be switched by setting the voltage applied to the terminals 211a and 211b so that the direction of the current flowing through the motor 211 is switched.

  Next, the configuration of the shutter unit 20 will be described in detail with reference to FIGS.

  4A and 4B are diagrams in which only main members of the shutter unit 20 are extracted. FIG. 4A is a plan view seen from the subject side (the main mirror side in FIG. 2), and FIG. 3B is a view seen from the subject side. FIG. 4C is a perspective view seen from the photographer side.

  5A and 5B are diagrams in which only the main members of the shutter unit 20 are extracted. FIG. 5A is a side view seen from the direction A in FIG. 4, and FIG. 5B is a side view seen from the direction B in FIG. It is.

  FIG. 6 is a partially enlarged view of the shutter unit 20. FIG. 6A is a plan view showing only the substantially right half of the shutter unit 20 as viewed from the subject side. Only the main shape of the mirror drive lever 202 is described. FIG. 6B is a view in which the mirror drive lever 202 is omitted from FIG. 6A and only the cam gear 204 is cut along a section CC in FIG. 5A. It should be noted that unnecessary parts are omitted for easy understanding of the drawings.

  4 to 6 all show the state of the shutter unit 20 when the camera 1 is stopped.

  A mirror drive spring (biasing member) Sp1 is attached to the mirror drive lever 202. In FIG. 6, the mirror drive spring Sp1 biases the mirror drive lever 202 in the clockwise direction (the direction in which the main mirror 13 is raised). The cam follower 202b is in contact with a first mirror cam surface 204a1 provided on the mirror cam 204a. The mirror cam 204a performs a charging operation of the mirror drive spring Sp1 of the mirror drive lever 202 via the cam follower 202b.

  The rear curtain drive lever 205 is attached with a rear curtain drive spring (second urging member) Sp2. In FIG. 6, the rear curtain drive spring Sp2 biases the rear curtain drive lever 205 in the clockwise direction (the direction in which the rear curtain blade group 212 is deployed). A roller 205 b provided on the rear curtain drive lever 205 is in contact with a rear curtain cam (drive cam) 204 b provided on the cam gear 204. In FIG. 6, the trailing curtain drive lever 205 is in an overcharge state. The rear curtain cam 204b performs a charging operation of the rear curtain drive spring Sp2 attached to the rear curtain drive lever 205 via the roller 205b. The urging force of the rear curtain drive spring Sp2 is stronger than the urging force of a blade lever urging spring Sp5 of the sub arm 212b described later.

  The rear curtain drive lever 205 is provided with an armature support portion 205c, and the armature support portion 205c is formed with a through hole (not shown). An armature shaft 209a which is integrally attached to the armature 209 and has a flange portion larger than the inner diameter of the through hole portion is engaged with the through hole portion. The armature shaft 209a extends in a direction substantially orthogonal to the suction surface of the armature 209. An armature separation spring (not shown) is disposed between the armature 209 and the armature support portion 205c. The matcher separation spring biases the armature 209 and the armature support portion 205c in a direction to separate them from each other.

  A drive pin 206 a provided on the blade lever 206 passes through a groove 201 f formed on the shutter base plate 201 and engages with a hole 212 a 1 formed on the main arm 212 a of the trailing blade group 212. The rear curtain blade group 212 includes a main arm 212a, a sub arm 212b, a first blade 212c, a second blade 212d, a third blade 212e, and a blade crimping dowel 212f, and forms a parallel link mechanism. Further, a blade lever biasing spring (fifth biasing member) Sp5 is attached to the sub arm 212b. The blade lever biasing spring Sp5 biases the force in the direction in which the trailing blade group 212 is superimposed. Since the drive pin 206a is engaged with the hole 212a1, the blade lever 206 and the main arm 212a operate integrally. The rotation range of the blade lever 206 is limited by the groove 201f. Further, the protrusion 206c provided on the blade lever 206 abuts on the protrusion 205d provided on the trailing blade driving lever 205, so that the blade lever 206 is moved when the trailing blade group 212 is deployed. And rotate together.

  A tension lever biasing spring (third biasing member) Sp3 is attached to the tension lever 207. In FIG. 6, the tension lever biasing spring Sp3 biases the tension lever 207 in the counterclockwise direction. 4 to 6, the cam follower 207a is not in contact with the tightening cam (locking cam) 204c, and the locking portion 207b of the tightening lever 207 is placed on the wall (projection) 206d of the blade lever 206. It is in a state of being hit. The locking portion 207 b locks the locked portion 206 b provided on the blade lever 206. Therefore, the trailing blade group 212 is maintained in the unfolded state without moving in the superimposing direction.

  At this time, a wall portion 206d is provided between the attracting surface of the electromagnet 210 and the armature 209, and the locking portion 207b and the locked portion 206b. By repeatedly engaging and releasing the locking between the locking part 207b and the locked part 206b, it is considered that the locking part 207b and the locked part 206b are worn and wear powder is generated. However, since the wall 206d is formed at the position described above, the generated wear powder is less likely to adhere to the attracting surfaces of the electromagnet 210 and the armature 209. Further, since the attracting surfaces of the electromagnet 210 and the armature 209 are not opposed to the retaining surfaces of the locking portion 207b and the locked portion 206b, the generated abrasion powder adheres to the attracting surface of the electromagnet 210 and the armature 209. It is difficult to do.

  Further, as shown in FIG. 5, the wall portion 206 d also has a role as a light shielding wall of the photo interrupter 215. The position of the blade lever 206 can be detected by allowing the wall 206d to block or pass the output light from the photo interrupter 215.

  A torsion coil spring (fourth urging member) Sp4 is attached to the bound lock lever 208. In FIG. 6, the torsion coil spring Sp4 biases the bound lock lever 208 in the counterclockwise direction. In FIG. 6, the bound lock lever 208 is in contact with the arc portion 206 e of the blade lever 206. When the tension lever 207 swings, the protrusion 207c of the tension lever 207 contacts the roller 208a, and the bound lock lever 208 swings.

  Next, the operation of the shutter unit 20 when actually photographing will be described with reference to FIGS.

  In the following explanation, the normal mode is the mirror drive mode that prioritizes the speed of the continuous shooting frame and the release time lag, and the mode that aims to silence the mirror operation sound instead of the slow speed of the continuous shooting frame and the release time lag. Is called “silent mode”. Among the silent modes, there are a “silent mode A” in which power saving is prioritized and a “silent mode B” in which the mirror operation sound is equivalent to the silent mode A and priority is given to shortening the release time lag. Here, the mirror operation sound refers to a collision sound that is generated when the main mirror holding frame 131 collides with the mirror box when the main mirror holding frame 131 moves back and forth with respect to the photographing optical path.

  Further, rotating the cam gear 204 clockwise as viewed from the subject side is defined as normal rotation and rotating counterclockwise is defined as reverse rotation. Similarly, the driving direction of the motor 211 when the cam gear 204 rotates in the forward direction is the forward rotation direction (first driving direction), and the driving direction of the motor 211 when the cam gear 204 rotates in the reverse direction is the reverse rotation direction (second driving direction). It is defined as The reverse direction is opposite to the normal direction.

  FIG. 7 is a diagram showing a list of the cam diagram of the cam gear 204, the control voltage of the motor 211, and the mechanical operation at each phase. Further, the control in each of the normal mode and the silent modes A and B is shown in a list, and drawing numbers (FIGS. 6 and 8 to 21) corresponding to the respective points are also described. In FIG. 7, the cam gear 204 is 360 degrees by moving in the order of angles A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, and A. It shows that it rotates. In FIG. 7, BL indicates a bound lock.

  8 to 21 are diagrams showing each operation state of the shutter unit 20. 8 to 21, as in FIG. 6, each figure (a) is a plan view showing only the substantially right half of the shutter unit 20 as viewed from the subject side. Only the main shape of the mirror drive lever 202 is described. Each figure (b) is the figure which abbreviate | omitted the mirror drive lever 202 from (a) of each figure, and has shown the state which cut | disconnected only the cam gear 204 in the cross section CC of Fig.4 (a). It should be noted that unnecessary parts are omitted for easy understanding of the drawings.

[Normal mode (first mirror drive mode)]
When the camera 1 is in the stop state, which is the first state, the cam gear 204 is in the camera stop state (first phase) shown between the angle A and the angle B in FIG. FIG. 6 shows the state of the angle A. When shooting in the normal mode, when the release button 31 is pressed halfway by the photographer while the camera is stopped, the signal SW1 is generated. When the signal SW1 is detected, photometry and focus detection are performed.

  Subsequently, when the release button 31 is fully pressed, the signal SW2 is generated. When the signal SW2 is detected, the armature 209 and the yoke 210a are attracted by energizing the coil 210b, and the cam gear 204 is rotated forward by applying a voltage in the normal rotation direction to the motor 211. As the cam gear 204 rotates forward, the angle of the cam gear 204 advances in the order of angles B, C, D, E, and F.

  FIG. 8 shows the state of the angle C, and shows the moment when the cam gear 204 rotates forward from the state of FIG. 6 and the locking of the blade lever 206 and the tightening lever 207 is released. In FIG. 8B, the tensioning cam 204c presses the cam follower 207a, whereby the tensioning lever 207 rotates clockwise, and the locking part 207b is disengaged from the locked part 206b. This state is called a “tightening release state”.

  FIG. 9 shows a state of the angle D, and shows a state where the blade lever 206 is rotated counterclockwise from the state of FIG. In FIG. 8, when the locking lever 207 and the blade lever 206 are unlocked, the blade lever 206 rotates counterclockwise. At this time, the rear-curtain blade group 212 changes from a state where it covers the opening 201e of the shutter base plate 201 to an open state. This operation of the blade lever 206 is referred to as “blade return operation”.

  In FIGS. 6 and 8, the bound lock lever 208 is stopped in contact with the arc portion 206 e of the blade lever 206. In FIG. 9, when the blade lever 206 is rotated counterclockwise, the bound lock lever 208 is also rotated counterclockwise, and the stopper portion 208b of the bound lock lever 208 is in contact with the projection 201g of the shutter base plate 201. At rest.

  The blade lever 206 that has performed the blade return operation causes a so-called bounce in which the protruding portion 206c does not collide with the protrusion 205d of the trailing curtain drive lever 205. However, since the lock portion 208c of the bound lock lever 208 enters the clockwise movement trajectory of the blade lever 206, the locked portion 206f of the blade lever 206 contacts the lock portion 208c, and the bound amount is limited. . Since the bound amount is limited, the bound time is also suppressed. A series of operations is called “bound lock operation”.

  The position where the stopper portion 208b of the bound lock lever 208 abuts against the protrusion 201g of the shutter base plate 201 is a restriction position that restricts the movement of the blade lever 206 from the open position to the closed position. After the blade lever 206 moves from the closed position to the open position, the bound lock lever 208 enters the movement locus of the blade lever 206, thereby restricting the movement of the blade lever 206 from the open position to the closed position.

  In FIG. 9, the cam follower 207a is in contact with the second cam surface 204c2 formed on the tightening cam 204c. That is, the tension lever 207 is in a state of rotating further clockwise than the state of FIG.

  Further, in FIG. 9, the roller 205b is separated from the cam surface 204b1 of the rear curtain cam 204b of the rear curtain cam 204b, and the overcharge state is released.

  FIG. 10 shows a state at an angle E, and shows a state in which the cam follower 202b of the mirror driving lever 202 is detached from the first mirror cam surface 204a1 of the mirror cam 204a and rotated clockwise. At this time, the contact portion 202a of the mirror drive lever 202 is in contact with the shaft portion 131b of the main mirror holding frame 131 (not shown in FIG. 10). The main mirror holding frame 131 is in contact with the mirror box and is retracted from the photographing optical axis. A series of operations is called “mirror up operation”.

  In FIG. 10, the cam follower 207a is in contact with the end of the second cam surface 204c2. That is, the tension lever 207 does not move between FIG. 9 (angle D) and FIG. 10 (angle E).

  FIG. 11 shows a state at an angle F, and shows a standby state before traveling (second state) in which the tension lever 207 and the bound lock lever 208 are rotated clockwise from the state of FIG. In the process of moving from the state of FIG. 10 to the state of FIG. 11, the tightening lever 207 is rotated clockwise by the cam follower 207a changing from the state of tracing the second cam surface 204c2 to the state of tracing the first cam surface 204c1. Rotate. The first cam surface 204c1 is formed such that the cam diameter from the rotation center to the outer peripheral surface is longer than that of the second cam surface 204c2. Further, the bound lock lever 208 rotates clockwise when the roller 208a is pressed by the protrusion 207c. At this time, the lock portion 208c of the bound lock lever 208 is retracted from the movement locus of the blade lever 206. A series of operations is called a “bound lock release operation”. The position where the lock portion 208c of the bound lock lever 208 is retracted from the movement locus of the blade lever 206 is the release position. Before the trailing curtain drive lever 205 drives the blade lever 206, the tension lever 207 moves the bound lock lever 208 from the restriction position to the release position.

  In the state of FIG. 11, a photographic exposure operation is started by performing reset scanning of the pixels of the image sensor 23 (hereinafter referred to as electronic front curtain travel). After the electronic front curtain travel starts, after the time interval corresponding to the set shutter time elapses, the current to the coil 210b is cut off, so that the armature 209 and the yoke 210a are separated. When the armature 209 and the yoke 210a are separated from each other, the trailing blade driving lever 205 and the blade lever 206 are integrally rotated clockwise by the urging force of the trailing blade driving spring Sp2. Accordingly, the rear curtain blade group 212 covers the opening 201e of the shutter base plate 201 as shown in FIG. The operation in which the trailing curtain drive lever 205 and the blade lever 206 travel together is referred to as “traveling operation”.

  Here, the voltage applied to the motor 211 in the section from the angle A to the angle F will be described. First, in the camera stop state, a voltage (first voltage) V1 is applied so as to cause the motor 211 to rotate forward. The driving force of the motor 211 is transmitted to the cam gear 204 via the gear train 213, and the cam gear 204 rotates forward. When the cam gear 204 is in the state of the angle D, the voltage applied to the motor 211 is switched to the voltage (second voltage) V2. When the cam gear 204 is in the state of the angle E, the voltage applied to the motor 211 is switched to the voltage (third voltage) V3. When the cam gear 204 is in an angle F state, the terminals 211a and 211b of the motor 211 are short-circuited. That is, by applying a so-called short brake to the motor 211, the cam gear 204 stops during the viewfinder imaging phase (second phase).

There is the following relationship between the absolute values of the voltages V1 to V3.
Voltage V1> Voltage V2 and voltage V3> Voltage V2

  The reason why the voltage V2 is lower than the voltage V1 is to perform the bound lock operation with certainty. The section in which the voltage V2 is applied (angle D to angle E, third phase) is a state in which the bound lock lever 208 enters the travel locus of the blade lever 206 as shown in FIGS. is there. However, there is a time lag until the blade lever 206 bounces after the blade lever 206 starts the blade return operation at the angle C until the locked portion 206f contacts the lock portion 208c. Therefore, if the voltage V2 remains high, the bound lock lever 208 may retract when the blade lever 206 bounces. That is, the bound lock releasing operation is performed before the bound lock operation is completed, and as a result, the bound time is extended.

  In order to perform the bounce lock operation with certainty, the normal shooting bounce lock phase indicated by the angles D to E may be set long, but if set too long, the cam gear 204 has a finite number of 360 degrees per cam rotation. Each phase cannot be efficiently assigned to the angle. In other words, by lowering the voltage V2, it is possible to efficiently use an angle of 360 degrees, and a larger angle can be assigned to work that requires a more angle such as charging. .

  After the bounce lock operation is performed in the normal shooting bounce lock phase, the bounce lock release operation is performed as soon as possible by driving the motor 211 with the voltage V3 higher than the voltage V2. By doing so, the release time lag can be shortened and the frame speed can be increased.

  After the traveling operation, the forward voltage is applied to the motor 211 again, and the cam gear 204 starts to rotate forward.

  When the cam follower 202b is pushed by the second mirror cam surface 204a2 from the angle G to the angle H, the mirror driving lever 202 rotates counterclockwise. FIG. 13 shows a state at an angle H, and shows a state in which the cam follower 202b is in contact with the first mirror cam surface 204a1. In FIG. 13, the mirror drive spring Sp1 has been charged. Further, the main mirror holding frame 131 is in a mirror-down state in which the main mirror holding frame 131 is lowered in conjunction with the mirror driving lever 202 and enters the photographing optical axis. A series of operations is called a “mirror charge operation”.

  From the angle I to the angle J, the tightening lever 207 rotates counterclockwise when the cam follower 207a changes from the state of tracing the first cam surface 204c1 to the state of tracing the second cam surface 204c3. FIG. 14 shows the state of the angle J. As the tightening lever 207 rotates counterclockwise, the bound lock lever 208 rotates counterclockwise and abuts against the arc portion 206e of the blade lever 206. At this time, the roller 208a is in a state separated from the protrusion 207c. A series of operations is called a “bound lock set operation”.

  From the angle K to the angle M, the cam follower 207a falls off from the second cam surface 204c3, and the tightening lever 207 rotates counterclockwise. FIG. 15 shows a state at an angle M, and shows a state in which the tension lever 207 is in contact with the wall portion 206 d of the blade lever 206. This operation of the tension lever 207 is referred to as “a tension setting operation”.

  From the angle M to the angle A, the rear curtain cam 204b of the cam gear 204 pushes the roller 205b to charge the rear curtain drive spring Sp2 and return to the initial state shown in FIG. This operation is called “rear curtain charge operation”. At this time, since the locking portion 207b locks the locked portion 206b, the blade return operation of the blade lever 206 is suppressed. Further, the rear curtain blade group 212 is configured to cover the opening 201e of the shutter base plate 201.

  Here, the voltage applied to the motor 211 in the section from the angle F to the angle A will be described. At the start of driving, the voltage V4 is applied so that the motor 211 rotates forward. The driving force of the motor 211 is transmitted to the cam gear 204 via the gear train 213, and the cam gear 204 rotates forward. When the cam gear 204 is in an angle P state, the voltage applied to the motor 211 is switched to the voltage V5. When the cam gear 204 is in the state of the angle A, the cam gear 204 is stopped during the phase of the camera stop state by applying a short brake to the motor 211.

There is the following relationship between the absolute values of the voltages V4 and V5.
Voltage V4> Voltage V5

  By performing such voltage control, the overrun of the cam gear 204 when the motor 211 is stopped becomes smaller than when the same voltage is applied to the motor 211. That is, the phase range in the camera stop state can be set small, and the idling time when the mirror is raised is shortened, leading to an increase in frame speed.

  The operations from the angle G to the angle A are collectively referred to as “charging operation”.

[Silent mode A (third mirror drive mode)]
Next, an operation when the camera 1 is set to the silent mode A will be described.
When the release button 31 is half-pressed by the photographer in the camera stop state, a signal SW1 is generated. When the signal SW1 is detected, photometry and focus detection are performed. Subsequently, when the release button 31 is fully pressed, the signal SW2 is generated. When the signal SW2 is detected, the armature 209 and the yoke 210a are attracted by energizing the coil 210b, and the cam gear 204 is reversed by applying a reverse voltage to the motor 211. As the cam gear 204 reverses, the angle of the cam gear 204 advances in the order of angles P, O, N, M, L, K, J, I, H, and G.

  FIG. 16 shows the state of the angle L, and shows the moment when the cam gear 204 reverses from the state of FIG. 6 and the locking of the blade lever 206 by the tightening lever 207 is released. In FIG. 16B, the cam follower 207a traces the tightening cam 204c, so that the tightening lever 207 rotates clockwise and the locking portion 207b is disengaged from the locked portion 206b. Further, the roller 205b is separated from the cam surface 204b1 of the trailing curtain cam 204b, and the overcharge state is released.

  FIG. 17 shows a state at an angle K, and shows a state in which the blade return operation and the bound lock operation are performed.

  FIG. 18 shows the state of the angle J. In FIG. 18, the cam follower 207a is in a state of tracing the end of the second cam surface 204c3. That is, the tension lever 207 does not move between FIG. 17 (angle K) and FIG. 18 (angle J).

  FIG. 19 shows a state at an angle I, where the cam follower 7a of the tension lever 7 is in contact with the end of the cam top 4c1.

  Bound lock release operation is performed between the angle J and the angle I, and the cam gear 204 is in the state of the angle H.

  FIG. 20 shows a state at an angle H, and shows a state in which the cam follower 202b is in contact with the end of the first mirror cam surface 204a1.

  FIG. 21 shows the state of the angle G. When the cam follower 202b moves along the second mirror cam surface 204a2 from the angle H to the angle G, the mirror driving lever 202 rotates clockwise and the mirror up operation is performed.

  In the mirror up operation in the normal mode, the cam follower 202b is executed by dropping from the first mirror cam surface 204a1. On the other hand, in the silent mode A, the cam follower 202b slides on the second mirror cam surface 204a2 from the first mirror cam surface 204a1 to perform the mirror up operation. Therefore, by controlling the rotational speed of the cam gear 204 to be slow, the rotational speed of the mirror drive lever 202 during the mirror up operation can be controlled to be slow, and as a result, the mirror operation sound can be reduced.

  Further, in the state of FIG. 21, the electronic front curtain traveling and the traveling operation are performed.

  Here, the voltage applied to the motor 211 in the section from the angle A to the angle G will be described. First, the voltage V11 is applied so as to reverse the motor 211. The driving force of the motor 211 is transmitted to the cam gear 204 via the gear train 213, and the cam gear 204 rotates in the reverse direction. When the cam gear 204 is in an angle K state, the voltage applied to the motor 211 is switched to the voltage V12. When the cam gear 204 is in the angle J state, the voltage applied to the motor 211 is switched to the voltage V13. When the cam gear 204 is in the state of the angle G, the cam gear 204 is stopped during the finder photographing phase by applying a short brake to the motor 211.

There is the following relationship between the absolute values of the voltages V11 to V13.
Voltage V11> Voltage V12 and Voltage V11> Voltage V13

  The reason why the voltage V12 is set lower than the voltage V11 is that the bound lock operation is reliably performed during the section (intermediate phase) between the angle K and the angle J, as in the normal mode. The reason why the voltage V13 is lowered is to control the rotational speed of the cam gear 204 to be low in order to reduce the mirror operation sound.

  In other words, the release time lag and the frame speed can be made as fast as possible by controlling the voltage V11 irrelevant to the bounce lock operation and the mirror operation sound with a high voltage.

  When the running operation is completed, a voltage in the forward direction is applied to the motor 211, the cam gear 204 starts to rotate forward, and the angles G, H, I, J, K, L, M, N, O, P, A Proceed in order.

  Since the operation from the angle G to the angle A performs the same operation as the charge operation in the normal mode, detailed description is omitted. Also in FIG. 7, the operation from the angle G to the angle A in the silent mode A is not shown.

[Silent mode B (second mirror drive mode)]
Next, an operation when the camera 1 is set to the silent mode B will be described.

  When the photographer presses the release button 31 halfway while the camera is stopped, a signal SW1 is generated. When the signal SW1 is detected, photometry and focus detection are performed, and when the coil 210b is energized, the armature 209 and the yoke 210a are attracted, and the reverse voltage V11 is applied to the motor 211 so that the cam gear 4 is Reverse. As the cam gear 4 reverses, the angle of the cam gear 4 advances in order of angles P, O, N, M, L, and K.

  When the angle K is reached, the voltage is switched to V12. When the angle I is reached, a short brake is applied to the motor 211 and the cam gear 4 stops between the angle I and the angle H. When the silent mode B is set, when the signal SW1 is output, the motor 211 is turned on so that the cam gear 204 is driven to a position just before the front mirror drive lever 202 starts moving to the mirror up position. 2 is driven in the driving direction. As long as the release button 31 is half-pressed, that is, as long as the signal SW1 is generated, the coil 210b is kept energized in this state. This state is referred to as “SW1 holding state”.

  When the signal SW2 is generated by fully pressing the release button 31 in the SW1 holding state, the reverse voltage V13 is applied to the motor 211, and the cam gear 4 advances by angles H and G. When the cam gear 4 reaches the angle G, a short brake is applied to the motor 211, and the cam gear 204 stops during the imaging phase.

  Since the operation of the shutter unit 20 at the angles A, L, K, J, I, H, and G is the same as that in the silent mode A, detailed description thereof is omitted.

  Then, as in the silent mode A, the electronic front curtain traveling and the traveling operation are performed in the state shown in FIG.

  When the traveling operation is completed, as in the silent mode A, a voltage in the forward direction is applied to the motor 211, the cam gear 4 rotates in the forward direction, and proceeds in the angles G, H, I.

  Since the operation from the angle G to the angle A performs the same operation as the charge operation in the normal mode, detailed description is omitted. Also in FIG. 5, the operation from the angle G to the angle A in the silent mode B is omitted.

  On the other hand, when the photographer releases the half-press without fully pressing the release button 31 from the SW1 holding state, the forward voltage V21 is applied to the motor 211 while energizing the coil 210b is maintained. Proceed with angles I, J, K, L, M, N, O, P. When the angle P is reached, the voltage applied to the motor is switched to the voltage V22. When the angle A is reached, a short brake is applied to the motor 211, and the cam gear 204 stops during the camera stop phase and cuts off the energization to the coil 210b. This operation is referred to as “return operation”. If the signal SW1 is not output without outputting the signal SW2 from the SW1 holding state, the motor 211 is driven in the first driving direction so as to drive the cam gear 204 until the state before the signal SW1 is output. .

  Here, the voltages V21 and V22 in the return operation and the voltages V4 and V5 in the charge operation will be described.

  During the charging operation, a mirror charge and a trailing curtain charge are applied. On the other hand, no mirror charge is performed during the return operation. In addition, since the energization of the coil 210b is maintained, the trailing curtain charge is not applied. Therefore, in order to make the overrun of the cam gear 4 in the charge operation and the overrun of the cam gear 204 in the return operation uniform, the voltages V21 and V22 in the return operation are different from the voltages V4 and V5 in the charge operation.

  By doing so, it becomes possible to align the release time lag in normal shooting immediately after performing the return operation and the release time lag in normal shooting immediately after performing the charging operation. You can keep it intact.

  Further, as can be seen from the description of the silent mode A and the silent mode B, the coil 210b is not energized even if the release button 31 is held half-pressed in the silent mode A. However, the release time lag is long.

  On the other hand, in the silent mode B, if the release button 31 is half-pressed, the coil 210b is kept energized, so that power is consumed compared to the silent mode A, but the release time lag is shorter than the silent mode A. is there.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

1 Camera 20 Shutter unit 31 Release button 32 Mode dial (setting means)
202 Mirror drive lever (mirror drive member)
202b Cam follower 204 Cam gear (charge member)
204a Mirror cam 211 Motor

Claims (3)

Mirror,
A mirror driving member for driving the mirror between a mirror up position and a mirror down position;
A biasing member that biases the mirror driving member;
A charge member for driving the mirror driving member against the urging force of the urging member to charge the urging member;
A motor for driving the charge member;
A release button that outputs a first signal when pressed halfway and a second signal when pressed fully;
Setting means capable of setting the first mirror driving mode or the second mirror driving mode,
When the first mirror driving mode is set, the motor drives the charging member in the first driving direction,
When the second mirror driving mode is set, the motor drives the charge member in a second driving direction opposite to the first driving direction,
When the second mirror driving mode is set, when the first signal is output, the charge member is driven to a position immediately before the mirror driving member starts moving to the mirror up position. The motor is driven in the second drive direction, and when the second signal is output, the motor is driven in the second drive so that the charge member is driven from the immediately preceding position. An imaging device that is driven in a direction.   In the case where the second mirror driving mode is set, the first signal is output without the second signal being output after the charge member is driven to the previous position. 2. The imaging apparatus according to claim 1, wherein the motor is driven in the first driving direction so that the charge member is driven to a state before the first signal is output when the first signal is output. 3. . The setting means can set a third mirror driving mode in addition to the first mirror driving mode and the second mirror driving mode,
When the third mirror driving mode is set, even if the first signal is output, the motor is not driven in the second driving direction so as to drive the charge member, 3. The imaging apparatus according to claim 1, wherein when the second signal is output, the motor is driven in the second driving direction so as to drive the charge member. 4.