JP2682653B2 - Camera lens shutter mechanism - Google Patents

Description

The present invention relates to a mechanism of a lens shutter used for a camera such as a single-lens reflex camera (hereinafter abbreviated as single-lens reflex camera).

[Prior Art] As is well known, a lens shutter which is normally in a fully open state and which is normally closed at the time of photographing and then opened and closed is known as one used for a single-lens reflex camera or the like. In this type of shutter, since the driving force of the shutter is charged from the camera body side, for example, the shutter charging is performed in conjunction with the film winding operation or the operation of the diaphragm lever. However, such an operation requires an extremely complicated procedure.

Therefore, the applicant of the present application has previously disclosed that, in Japanese Patent Publication No. 58-34818, the shutter blades of the lens shutter are opened and closed by a shutter opening ring and a shutter closing ring. We proposed a lens shutter for a single-lens reflex camera that can be automatically operated in conjunction with the shutter release on the side.

[Problems to be Solved by the Invention] However, even in the lens shutter proposed by the present applicant, since the shutter is charged by the diaphragm lever inside the camera body, the mechanism has to be complicated accordingly. It was

Therefore, an object of the present invention is to eliminate the above-mentioned inconvenience, provide a drive source for the lens shutter on the lens side, make charge from the camera body side unnecessary, and simplify the mechanism.
An object is to provide a lens shutter mechanism that is in a fully opened state in the initial state.

[Means and Actions for Solving Problems] A lens shutter mechanism of a camera according to the present invention has shutter blades for opening and closing a photographing lens opening, and the shutter blades are set to a predetermined open state in an initial state before starting photographing. Yes,
In a lens shutter mechanism of a camera, which is opened and closed for shooting exposure after being fully closed according to a shooting operation, is pivotally supported by a blade drive member that opens and closes the shutter blade by swinging and a stationary member. A support arm that swingably supports the blade drive member and that rotates to a first position that allows the shutter blade to open and a second position that closes the shutter blade; and the blade. The opening amount of the shutter blade is controlled by swinging the driving member.
AE means, an electric drive source for driving the AE means, and a holding means for mechanically holding the support arm in the first position, and in the initial state before the start of photographing, The supporting means is mechanically held at the first position by the holding means, and the blade driving member is swung to a position where the shutter blade is brought into a predetermined open state by the AE means. Is capable of passing through the taking lens.

[Examples] Prior to the description of the examples of the present invention, the basic operation of the single-lens reflex camera to which the present invention is applied during shooting will be described with reference to FIG. In FIG. 2, the photographer captures the subject light that passes through the taking lens 60, is reflected by the movable reflecting mirror 65, passes through the pentaprism 66 and the finder lens 64, and enters the eye 67 of the photographer. Make decisions and focus. Therefore, at this stage, the lens shutter 61 of the taking lens 60 is opened, the subject light is guided to the finder optical system, and the subject light is blocked by the light blocking member 63 so that the film 62 is not exposed.

At the time of photographing, first, the lens shutter 61 is closed to cut the subject light, the movable reflecting mirror 65 is raised, and the light shielding member 63 is removed from the front of the film 62 to switch from the finder optical system to the photographing optical system. . Next, the opening / closing of the lens shutter 61, that is, the exposure time and the aperture value are controlled so that the film 62 is irradiated with the required amount of subject light.

The lens shutter mechanism of the camera according to the present invention will be described below with reference to the exploded perspective view of the first embodiment shown in FIG. In FIG. 1, a motor 11 which is an electric drive source is rotatable in forward, reverse and both directions by a control signal from a control circuit (not shown), and a drive gear 12 provided on its output shaft is rotated by gears 13 and 14. It is adapted to be transmitted to the gear 15 via. The gear 13 is fixed with a reflection plate 28 formed with a white (reflection surface) and black (non-reflection surface) pattern, and by a photo reflector 27 arranged facing the reflection plate 28,
A pulse corresponding to the rotation of the motor 11 is detected.

The transmission system is divided into two systems after the gear 15, and one transmission system includes gears 16 and 17 and a cutout 17a formed in the gear 17.
An automatic focus transmission system (hereinafter, referred to as an AF transmission system) comprising a one-way clutch 18 fitted to the clutch 18 and a ratchet 19 and an AF cam member 20 coaxially integrated with the clutch 18. This one-way clutch 18 of the AF transmission system is a notch of the gear 17 when the gear 17 rotates counterclockwise (the rotation direction is the upper side in FIG. 1, that is, the direction viewed from the subject side, the same applies hereinafter). Department
The gear 17 engages with and transmits the rotation, but when the gear 17 rotates in the clockwise direction, it slips at the notch 17a and does not transmit the rotation.

The other transmission system is an automatic exposure system including a one-way clutch 21 fitted in a cutout 15a formed in the gear 15, a gear 22 coaxially integrated with the clutch 21, gears 23 and 24, and an AE cam gear 25. Transmission system (hereinafter referred to as AE transmission system). The lower surface of the AE cam gear 25 is an AE means around the exposure opening.
The AE cam 26 is integrally formed, and further, on the outer side of the AE cam 26, a restricting cam 49 which is a holding means is integrally formed at a position equidistant from the optical axis O over substantially a half circumference. This one-way clutch 21 of the AE transmission system engages with the cutout portion 15a of the gear 15 when the gear 15 rotates in the clockwise direction and transmits the rotation, but cuts out when the gear 15 rotates in the counterclockwise direction. It slips within 15a and does not transmit rotation.

A locking claw 29 is engaged with the ratchet 19 of the AF transmission system by being given a biasing force by a spring. Projections 20a and 20b are formed on the side of the AF cam member 20, and the projection 20a
The switch 30 is turned on at an initial position facing the switch 30, and the protrusion 20b is locked by a brake spring 31 biased in a direction opposite to the rotation direction of the AF cam member 20, and the AF The cam member 20 is stopped at the initial position.

On the lower surface of the AF cam member 20, a three-dimensional cam surface 20c is formed. This three-dimensional AF cam surface 20c is a shutter case integrated with a lens holding barrel 32 holding a taking lens (not shown).
33 faces the planting pin 33a. This lens holding tube 3
The shutter case 33 integrated with 2 has guide grooves 33c and 33d,
The guide members 40c and 40d to which the base plate 40 is attached are engaged and movable in the direction along the optical axis O (hereinafter, referred to as the optical axis direction), and are constantly moved by the spring 34 to the subject side in the upper part of the drawing. Since it is biased, when the AF cam member 20 rotates, the AF
The pin 33a slides on the cam surface 20c, and the shutter case 33 moves in the optical axis direction according to the shape of the AF cam surface 20c.

Two blades 35a and 35b forming a vario-type shutter 35 are attached to the lower surface side of the shutter case 33, and are supported by support pins 37 and 38 which are planted in the shutter case 33. In the long hole 33b formed in the shutter case 33, a blade driving lever 39, which is a blade driving member, is provided from above.
The drive pin 39a fixed at one end of the
9a is fitted in the driving long holes of the blades 35a, 35b. The drive pin 39a fitted in the drive long hole further extends in the optical axis direction and is locked to the restricting surface 51a of the restricting arm 51 arranged inside the zoom ring 50. The base end of the regulating arm 51 is rotatably supported by a boss provided at a position (not shown) of the shutter case 33. The regulating arm 51 is urged in one direction by a spring 52, and its tip 51b is in contact with the cam surface 50a on the inner periphery of the zoom ring 50. Therefore, when the zoom ring 50 is rotated with respect to the shutter case 33 that is immovable in the rotation direction, the tip 51b of the regulation arm 51 slides on the cam surface 50a, so that the position of the regulation surface 51a of the regulation arm 51 is the cam surface. The drive pin 39a is displaced in accordance with the shape of 50a and regulates the opening side position on the path in which the drive pin 39a moves.

A magnet interlocking arm 41, which is a support arm, is rotatably attached to a boss (not shown) of the main plate 40, and the blade drive lever 39 is rotatably provided around a pin 41a fixedly provided at the tip of the arm 41. It is arranged. The blade drive lever 39 is constantly urged counterclockwise by a spring 42. The pin 39b is attached to the other end of the blade drive lever 39.
Is fixed and the pin 39b is in contact with the cam surface of the AE cam 26, so when the AE cam gear 25 rotates, the position of the pin 39b is displaced according to the shape of the cam surface of the AE cam 26. The blade drive lever 39 rotates, which causes the drive pin 39
The position of a is displaced.

The magnet interlocking arm 41 is urged counterclockwise by a spring 43. An armature 45 that can be attracted to the magnet 44 is attached to the tip of the magnet interlocking arm 41 by a screw 47 via a coil spring 46.
The interlocking arm 41 is attracted by a magnet 44 via an armature 45 in a direction opposite to the urging direction of the spring 43. A pin 41b is fixedly provided on the upper surface of the magnet interlocking arm 41 in the figure, and
1b (holding means) is an AE cam gear that faces the restriction cam 49.
In the rotating state of 25, it comes into contact with the restriction cam 49 (holding means), so in this state, the magnet interlocking arm 41 compresses the coil spring 46 to press the armature 45 against the magnet 44. The rotation is restricted while the biasing force of the spring 43 is maintained at the overcharge position. Therefore, when the magnet interlocking arm 41 is subsequently attracted to the magnet 44 via the armature 45, the attracted state is maintained, as will be described later.

An AE switch 48 is attached to the main plate 40, and the switch 48 is turned on or off depending on the presence or absence of a protrusion 25a formed on the peripheral portion of the upper surface of the AE cam gear 25.

Next, the operation of the embodiment shown in FIG. 1 will be described with reference to the time chart shown in FIG. 3 and the shapes of the AE cam 26 and the restriction cam 49 shown in FIG.

First, the motor 11 is controlled by a control signal from the control circuit.
Is driven forward. Then, since the drive gear 12 rotates clockwise, the driving force is transmitted to the gear 15 via the gears 13 and 14, and the gear 15 rotates counterclockwise. Further, the power is transmitted to the gear 17 via the gear 16, and the gear 17 rotates counterclockwise. When the gears 15 and 17 rotate counterclockwise,
The driving force of the motor 11 is changed from the one-way clutch 21 to the AE cam gear.
The ratchet 19 and AF, which are not transmitted to the AE transmission system up to
The cam member 20 rotates counterclockwise.

When the AF cam member 260 rotates a certain angle, the protrusion 20a
Separated from the AF switch 30, the switch 30 is turned off. Then, the photo reflector 27 starts counting the rotation amount of the gear 13. When the AF cam member 20 rotates, the lens holding cylinder 32 is moved by the AF cam surface 20c at the lower end thereof.
The shutter case 33 which is integral with the camera is retracted. While the AF cam member 30 is rotating, the ratchet 19 is fed step by step by the locking claw 29 to rotate. And another not shown
When the photoreflector 27 counts the number of pulses corresponding to the revolving amount of the shutter case 33 appropriate for the AF information obtained from the AF detection device, the control circuit applies a short brake to the motor 11 and then reverses the motor 11 .

When the motor 11 is driven in the reverse direction, the drive gear 12 rotates counterclockwise, so that the gears 15 and 17 rotate clockwise.
Therefore, in this case, the driving force of the motor 11 is transmitted to the AE transmission system from the one-way clutch 21 to the AE cam gear 25, but the driving force is not transmitted to the one-way clutch 18 of the AF transmission system, and , A ratchet integrated with this clutch 18
Since the rotation of this member 19 in this direction may be restricted by the locking claw 29, the AF cam member 20 does not rotate and maintains the retracted position of the shutter case 33 integrated with the lens holding cylinder 32.

When the driving force of the motor 11 is transmitted to the AE transmission system, the AE
The cam gear 25 rotates counterclockwise, and the AE cam 26 and the regulation cam 49 also rotate in the same direction integrally with the cam gear 25. As will be described later, since the magnet interlocking arm 41 is held in the charged state (overcharge position), the tip end of the magnet interlocking arm 41, that is, the center of rotation of the blade drive lever 39 is located far from the optical axis O. Is held.

Thereafter, the blade drive lever 39 is moved to the rotating AE cam 26.
Rotate according to the shape of the cam surface. As can be seen from FIG. 4, the shapes of the cam surfaces of the AE cam 26 and the restriction cam 49 viewed from the upper side, that is, from the subject side, are clearly shown in FIG. The intermediate position 26a on the cam surface 26b in the circumferential direction close to O is opposed, and the pin 41b of the magnet interlocking arm 41 is opposed to the intermediate initial position 49a of the regulation cam 49. After that, when the AE cam 26 and the restriction cam 49 rotate counterclockwise, the pin 39b moves to the optical axis O.
From the state of contacting the circumferential cam surface 26b close to
Since the blade drive lever 39 comes into contact with the inclined cam surface 26c that is steeply moving away from the optical axis O, the blade drive lever 39 starts to rotate clockwise. Therefore, the drive pin 39a moves in the direction of approaching the optical axis OH through the long hole 33b of the shutter case 33, whereby the blades 35a and 35b are closed. The light shielding member 63 and the movable reflecting mirror shown in FIG. 2 are opened by a mechanism (not shown) to switch from the finder optical system to the photographing optical system.

By the way, the pin 41b of the interlocking arm 41 is still on the regulation cam 4
It is on 9 and holds the charged state, but here,
The magnet 44 is excited by energization, and the armature 45
When the interlocking arm 41 is attracted to the magnet 44 via the
As the cam gear 25 rotates, the pin 41b disengages from the terminal 49c of the restriction cam 49. Since the charged state is maintained even if the pin 41b is disengaged from the restriction cam 49 and the overcharge of the magnet interlocking arm 41 is released, the fulcrum position of the blade drive lever 39 remains fixed at a position far from the optical axis O. .

That is, the magnet interlocking arm 41 is still in the first position where the shutter blade can be opened.

The AE cam gear 25 further rotates counterclockwise, and the pin 39b of the blade drive lever 39 passes through the cam surface 26d ₀ at the position farthest from the optical axis O and gradually approaches the optical axis O.
When it comes into contact with d, the blade drive lever 39 starts rotating counterclockwise. Therefore, the drive pin 39a moves in the direction away from the optical axis O, whereby the blades 35a and 35b of the shutter 35 start to open and exposure is started.

The AE switch 48 is initially on,
It is turned off by the projection 25a immediately before the start of exposure. Then, using this as a trigger, AE integration is started in the control circuit. When the integration is completed and the exposure end signal is output from the control circuit, the magnet 44 releases the attraction and holding of the interlocking arm 41, so that the interlocking arm 41 is rotated counterclockwise by the biasing force of the spring 43, The center of rotation of the blade drive lever 39 is displaced to a second position where the shutter blade is closed, and the drive pin 39a is moved toward the optical axis O all at once. This causes the blades 35a, 35b to close. In the case of long-time exposure, the rotation of the AE cam gear 25 is temporarily stopped while the pin 39b of the blade drive lever 39 is located on the cam surface 26e closest to the optical axis O, and an appropriate exposure time elapses. AE cam gear again later
25 rotates.

By the way, when changing the focal length,
Rotate 50 to set it to a position corresponding to the focal length.
When the zoom ring 50 rotates, the distal end 51b of the regulating arm 51 slides on the cam surface 50a, and the position of the regulating surface 51a of the regulating arm 51 existing on the path of the drive pin 39a changes. In accordance with the change, the opening position of the drive pin 39a on the passage is regulated. Therefore, when the blades 35a, 35b are opened by the drive pin 39a, the drive pin 39a stops when regulated by the regulation surface 51a, and the maximum aperture opening diameter at this time is the regulation surface 51a of the regulation surface 51a according to the focal length. Determined by position.

After the exposure for an appropriate time is performed and the blades 35a and 35b are closed, the AE cam gear 25 further rotates and the magnet interlocking arm 41 is charged. That is, after the end of exposure,
The AE cam gear 25 rotates further, and the above-mentioned cam surface 26 of the AE cam 26
Inclining cam surface 26f, which is continuous with e and steeply moves away from the optical axis O
When the pin 39b of the blade drive lever 39 is pushed in the direction away from the optical axis O by the pin 39b to reach the cam surface 26g farthest from the optical axis O, the drive pin 39a moves the blade 35a,
Since 35b is closed and it is attached to the shutter case 33,
A force against the biasing force of the spring 43 acts on the tip of the magnet interlocking arm 41, which is the center of rotation of the blade drive lever 39, and the interlocking arm 41 compresses the coil spring 46 and causes the magnet 44 to move to the magnet 44 via the armature 45. It is pressed and reaches the overcharge position.

After charging the interlocking arm 41, the AE cam gear 25 further rotates to move from the cam surface 26g of the AE cam 26 to the inclined cam surface 26h that steeply approaches the optical axis O. It reaches one end 49d of the regulation cam 49,
It is locked at the same end 49d. Therefore, the charged state thereafter is maintained by the pin 41b contacting the regulation cam 49 and moving while being regulated by the cam.

When the AE cam gear 25 further rotates and the pin 39b of the blade drive lever 39 reaches the cam surface 26h of the AE cam 26, the blade drive lever 39 starts to rapidly rotate counterclockwise, and the drive pin 39a emits light. It moves in a direction away from the axis O, whereby the blades 35a, 35b of the shutter 35 open. Then, the pin 39b becomes the cam surface 26.
When reaching the top, the blades 35a and 35b are fully opened. Prior to the operation of opening the shutter blades 35a, 35b, the movable reflecting mirror 65 and the light shielding member 63 are set to the initial state shown in FIG. 2, and the optical system is switched from the photographing optical system to the finder optical system.

After this, the AE switch 48 switches from off to on,
The signal stops the motor 11, and the pin 39b of the blade drive lever 39 is reset to the initial position 26a of the AE cam 26, and the pin 41b of the interlocking arm 41 is reset to the initial position 49a of the restriction cam 49. After that, the motor 11 rotates forward again and the AF cam member
The rotation is transmitted to 20, and the AF cam surface 20c retracts the shutter case 33 in the direction toward the reset position. Then, the AF switch 30 immediately before the reset position is switched from OFF to ON, and the short brake is applied to the motor 11 by the signal. At this time, after the AF switch 30 is switched, the protrusion 20b of the AF cam member 20 and the brake spring 31
And the brakes act on the AF cam member 20, and the AF cam member 20 stops at the initial position.

In the present embodiment, the charge state of the shutter 35 is held directly by the restriction cam 49 on the AE cam gear 25, but it is needless to say that it may be held by another member. is there.

 Next, a second embodiment of the present invention will be described.

FIG. 5 shows an exploded perspective view of the second embodiment of the lens shutter mechanism.

In FIG. 5, a focusing frame 73 is fixed by screws 74 on the back side of a main body 72 to which a motor 71 as a drive source for autofocus and shutter driving is attached. The focusing frame 73 is provided with a focusing mechanism 75. The focusing mechanism 75 includes a cylindrical AF cam member 76 rotatably attached to the focusing frame 73 around the optical axis O of the photographing optical system,
A cam surface 76a that is displaced in the optical axis direction is formed on the inner circumference of the cam member 76. Further, the focusing mechanism 75 includes a focusing drive gear train 77 that meshes with a gear portion formed on the outer periphery of the AF cam member 76, and a timing switch 78 that contacts the outer peripheral surface of the AF cam member 76. The timing switch 78 is a switch that detects the initial position of the cam member 76 at the start of focusing and controls the rotation amount of the cam member 76 in response to a signal from the photo interrupter 86 (see FIG. 6). . Further, the focusing frame 73 includes a shutter drive gear train 79 and both gear trains.
A planetary clutch 80 located between 77 and 79 is provided. The drive gear 81, which is the sun gear of the planetary clutch 80, is fixed to the output shaft 71a of the motor 71.

As shown in detail in FIG. 6, the planetary clutch 80 is configured such that two planetary gears 82 and 83 are held by a planetary lever 84 while the two gears 82 and 83 are simultaneously meshed with the drive gear 81. Since the planet lever 84 is rotatably attached to the output shaft 71a of the motor 71 with a predetermined frictional force, when the output shaft 71a of the motor 71 rotates forward in the direction of arrow A, the planet lever 84 is rotated. Also rotates in the same direction, and one planetary gear 82
Meshes with the focusing drive gear train 77. This
The AF cam member 76 rotates to perform focusing. When the output shaft 71a rotates in the direction opposite to the arrow A, the other planet gear 83 meshes with the shutter drive gear train 79 to drive the gear train 79. At the tip of the output shaft 71a of the motor 71,
A rotary member 85 having slits formed at equal intervals on the peripheral edge is fixed, and a photo interrupter 86 is arranged so as to sandwich the peripheral edge of the rotary member 85. The photo interrupter 86 counts the slits of the rotating member 85 during rotation of the motor 71, converts the pulse into an electric signal, and sends the electric signal to a control circuit (not shown) to control the rotation of the motor 71.

A lens holding frame 87 is arranged on the front side of the main body 72. The lens holding frame 87 is configured to be movable in the optical axis direction with respect to the main body 72 by a focusing guide shaft 88 provided parallel to the optical axis O and a guide post 89 implanted in the main body 72. Front holding part 87 of lens holding frame 87
The flange 91a of a and the flange 91b of the rear holding portion 87b are provided in parallel to each other in a direction perpendicular to the optical axis O. Between the two flanges 91a and 91b, as shown in FIG.
As shown in (B), a vario-type shutter 92 formed of two blades 92a and 92b is provided. Rear holding part 87
A pin 93 is planted on the outer periphery of b at a position facing the cam surface 76a of the AF cam member 76. Since this lens holding frame 87 is biased rearward by an elastic member (not shown), the rear holding portion 87b is located inside the AF cam member 76 through the opening 72a of the main body 72, and the cam pin 93 is provided on the cam surface 76a. Abutting.

A shutter 92 arranged between the two flanges 91a and 91b
Is a flange 91b as shown in FIGS. 7 (A) and 7 (B).
A pair of blades 92a, 92b are rotatably supported by pins 94a, 94b planted in the. Further, elongated holes 96a and 96b are formed in the blades 92a and 92b, respectively, and drive pins 95 to be described later are fitted to the overlapping portions of these elongated holes 96a and 96b. When the drive pin 95 moves toward the center of the opening 97 of the flanges 91a and 91b, that is, toward the optical axis O of the photographing optical system, the blades 92a and 92b close (see FIG. 7A), and the flanges The blades 92a and 92b open when moving away from the center of the opening 97 of the 91a and 91b, that is, in the direction away from the optical axis O of the photographing optical system (see FIG. 7B).

A shutter frame 98 is arranged on the front side of the lens holding frame 98, and a shutter drive mechanism 99 is provided on the shutter frame 98. A cover 100 that covers the shutter drive mechanism 99 is attached to the front surface side of the shutter frame 98 with screws 101.

The shutter drive mechanism 99 has an AE cam gear 102, which is connected to the shutter drive gear train 79 via idler gears 103, 104 and a connecting gear 105. As shown in FIG. 8, on the upper surface of the AE cam gear 102, the pin 102a (AE means) is eccentric from the rotation center of the cam gear 102.
And the cam surface 102b is formed on the lower surface of the AE cam gear 102. A concave portion 102c is formed on the cam surface 102b over a certain angle range. And this cam surface 10
The variable lead terminal of the AE switch 106 attached to the shutter frame 98 is in contact with 2b. Further, the shutter drive mechanism 99 has a magnet interlocking arm 107 (support arm) and a blade drive lever 108. An intermediate portion of the magnet interlocking arm 107 is rotatably supported by a support shaft 109 embedded in the shutter frame 98. An armature 110 (holding means) is attached to one end of the magnet interlocking arm 107 via a spring 110a that contracts when the arm 107 is moved to the overcharge position, and the armature 110 is fixed to the shutter frame 98. It faces the on-type magnet 111 (holding means). At the other end of the magnet interlocking arm 107, an intermediate portion of the blade drive lever 108 is rotatably supported by a support shaft 112. The magnet interlocking arm 107 has the habit of rotating clockwise around the support shaft 109 by the urging force of the torsion spring 113a.
108 has the habit of rotating clockwise around the support shaft 112 by the urging force of the torsion spring 113b. Blade drive lever 108
A cam surface 108a (AE means) capable of contacting the pin 102a of the AE cam gear 102 is formed near one end of the. A drive pin 95 is planted on the other end of the blade drive lever 108 on the surface facing the shutter frame 98. The drive pin 95 penetrates an elongated hole 114 formed in the shutter frame 98 and further holds the lens. Through the through holes 115 formed in the flange 91a of the frame 87, the blades 92a and 92b of the shutter 92 penetrate through the long holes 96a and 96b.

Further, a regulating lever 116 for adjusting the movement amount of the drive pin 95 is rotatably attached to the shunter frame 98. The regulating lever 116 is biased counterclockwise by a spring 117, and one end 116a of the regulating lever 116 is pressed against an aperture regulating member 118 for regulating the opening diameter when the shutter is opened.
Further, the other end 116b of the restriction lever 116 can enter the moving passage of the drive pin 95 as the restriction lever 116 rotates.

Next, regarding the operation of the second embodiment, FIG. 9 (A)
The operation will be described with reference to the operation charts shown in (E) and the time chart shown in FIG. In FIGS. 9A to 9E, the magnet interlocking arm 107 and the blade drive lever 108 are shown.
Of the torsion springs 113a and 113b to facilitate understanding of the movement of the
Is represented by an ordinary spring.

The motor 71 is rotated forward, and the planetary gear 82 of the planetary clutch 80 is rotated.
Is engaged with the focusing drive gear train 77, the AF cam member 76 rotates via the focusing drive gear train 77, and the pin 93 of the rear holding portion 87b pressed against the cam face 76a of the cam member 76 has the cam face. Moves following the displacement of 76a.
As a result, the lens holding frame 87 moves along the optical axis direction for focusing. At this time, the timing switch 78 for detecting the initial position of the AF cam member 76 is turned off at the same time when the rotation of the cam member 76 is started, and in synchronization with this, the photo interrupter 76 counts drive pulses. And
When the count reaches a specified value, that is, the AF cam member
When the rotation amount of 76 reaches a predetermined value, the motor 71 stops and the focusing ends.

Subsequently, the motor 71 starts reverse rotation, and the shutter drive mechanism
The driving of 99 is started. That is, the reverse rotation of the motor 71 causes the planetary gear 83 of the planetary clutch 80 to move to the shutter drive gear train.
It engages with 79 and drives this. This driving force is the connecting gear 10
Is transmitted to the idler gears 104, 103 via 5, and as a result,
The AE cam gear 102 rotates in the direction of arrow B. In the initial state, in the state shown in FIG. 8 and FIG. 9 (A), the armature 110 of the magnet interlocking arm 107 is mechanically held by being attracted to the magnet 111 in the energized / off state and the shutter 92 of the shutter 92. The blades 92a and 92b are open as shown in FIG. 7 (B). Further, as shown in FIG. 9 (B), at the beginning of rotation of the AE cam gear 102, the blade drive lever 108 moves the cam surface 108a by the pin 102a on the AE cam gear 102.
Is pressed to rotate counterclockwise against the biasing force of the torsion spring 113b. In this state, the drive pin 95 of the blade drive lever 108 is located at the lower end of the elongated hole 114 (see FIG. 8) near the optical axis O, and the shutter blades 92a and 92b are closed. When the drive pin 95 reaches the lower end of the elongated hole 114 close to the optical axis O and the rotation of the blade drive lever 108 about the support shaft 112 is blocked, the magnet interlocking arm 107 then sets the support shaft 109. A slight counterclockwise force is applied as the center, and the armature 110 passes the overcharge position where it is strongly pressed against the magnet 111.

Then, as shown in FIG. 9 (C), the AE cam gear 102
When is further rotated, the pin 102a moves in a direction away from the blade drive lever 108, so that the blade drive lever 108 rotates clockwise while following the pin 102a by the biasing force of the torsion spring 113b. As a result, the drive pin 95 of the blade drive lever 108 moves upward so as to move away from the optical axis O through the elongated hole 114, and the blades 92a and 92b of the shutter 92 gradually open.
Here, the variable lead terminal of the AE switch 106 is the AE cam gear 1
Since it falls into the recess 102c of the cam surface 102b of 02,
The AE switch 106 is turned on, and then the shutter blades 92a and 92b start to open, and at the same time, the variable lead terminal of the AE switch 106 comes into contact with the cam surface 102b again and the AE switch 106
Turns off. Then, when the AE switch 106 is switched off, a shutter control circuit (not shown) operates,
The proper shutter opening time is determined. When the proper opening time is reached, that is, when the proper exposure is reached, the driving of the motor 71 is stopped, the magnet 111 is turned on, and the attraction of the armature 110 is released. As a result, the magnet interlocking arm 107 rotates clockwise around the support shaft 109 together with the blade drive lever 108 by the biasing force of the torsion spring 113a, as shown in FIG. 9D. Therefore, the drive pin 95 of the blade drive lever 108 has the optical axis O of the long hole 114.
The shutter 92 moves down to the lower end position near the
Blades 92a, 92b are closed.

After this, the AE cam gear is further driven by driving the motor 71.
When the blade 102 rotates in the direction of arrow B, the blade drive lever 108 causes the pin 1 contacting the cam surface 108a as shown in FIG. 9 (E).
Pressed by 02a, the magnet interlocking arm 107 rotates counterclockwise around the support shaft 109 against the biasing force of the torsion spring 113a. As a result, the magnet interlocking arm 107 once reaches the overcharge position, and the armature 110 is reliably attracted to the magnet 111. When the charging of the magnet interlocking arm 107 is completed and the AE cam gear 102 further rotates, the blade driving lever 108 rotates clockwise, and the blades 92a and 92b of the shutter 92 are opened. Then, the driving of the motor 71 is stopped, and the state returns to the initial state of FIG. 9 (A).

The restriction lever 116 is pressed by the opening restriction member 118 to restrict the amount of rotation in the counterclockwise direction. Since the other end 116b of the restriction lever 116 projects into the movement path of the drive pin 95 according to this rotation amount, the movement amount of the drive pin 95 is restricted by the restriction lever 116, and the maximum opening diameter of the shutter blades 92a, 92b becomes smaller. Regulated.

Also in this embodiment, as described above, the lens shutter that performs the series of operations described above and another light blocking member 63 such as a mirror shutter or a focal plane shutter are used.
(See FIG. 2) is used in combination to control at the timing shown in FIG. 10, a shutter for a single-lens reflex camera can be realized.

In this embodiment, since a gear having a small diameter is used as the AE cam gear 102, the driving force may be small and the space can be reduced. Furthermore, the blade drive lever 108
Unlike the first embodiment, there is no need to mechanically lock the restriction cam 49 (see FIG. 1) or the like, the number of parts is reduced, and the structure is inexpensive and simple.

 Next, a third embodiment of the present invention will be described.

In the lens shutter mechanism of the embodiment shown in FIG. 11, the rotational driving force of the motor 201, which is the driving source for performing the focus adjustment (AF) operation and the exposure control (AE) operation, is the AE / AF switching It is adapted to be transmitted to the differential gear mechanism 203. That is, the sun gear 204 of the differential gear mechanism 203 is coupled to the output shaft 201a of the motor 201, and a large-diameter carrier gear (hereinafter referred to as a carrier) 205 rotates around the boss portion of the sun gear 204. It is arranged freely. In the sun gear 204, three planets rotatably supported by three support shafts 205a, in which the front surface of the carrier 205 is arranged at an equal angle to the crocodile at a position where the front surface of the carrier 25 protrudes, Gear 206 meshes. The three planetary gears 206 mesh with the internal teeth 207a of the internal gear 207. External teeth 2b are formed on the outer circumference of the internal gear 207.
Are formed.

The operation of the differential gear mechanism 203 will now be described. The rotation of the sun gear 204 is transmitted to the planet gear 206. When the rotation of the carrier 205 is restricted, the support shaft 205a is also immobile, and the planet gears 206 rotate about the support shaft 205a, respectively, and the internal gear 207 rotates accordingly. On the other hand, when the rotation of the internal gear 207 is restricted, the planetary gears 206 rotate around the support shaft 205a and rotate along the internal teeth 207a of the internal gear 207, respectively.
Revolve around. Therefore, the support shaft 205a also moves as the planetary gear 206 moves, and as a result, the carrier 205 rotates.

External teeth 207b of the internal gear 207 of the differential gear mechanism 203 mesh with the AF gear 208. This AF gear 208 has internal gear 20
Since the click spring 210 is in pressure contact with the position where the engagement with the gear 7 cannot be prevented, a load due to the click is applied to the rotation of the AF gear 208. At the front end of the AF gear 208, the AF cam surface 208
a is formed, and the same cam surface 208a is in contact with the projection 212a that is integral with the lens frame 212 holding the taking lens 211. Mirror frame 2
12 is a state in which the convex portion 212b is fitted in the guide groove 213a of the rotation stopper 213 and is supported movably in the direction along the optical axis o,
Since the projection 212a is pressed against the AF cam surface 208a by the spring 215 inserted in the support shaft 214, the lens frame 212
Is extended or retracted in the optical axis direction when the AF gear 208 rotates. An appropriate number of reflection patterns (not shown) are formed on the back surface of the AF gear 208,
A rotation detector 216 composed of two sets of photo reflectors for detecting the rotation direction and the rotation amount of the AF gear 208 is arranged at a position facing the reflection pattern.

On the other hand, the carrier 205 of the differential gear mechanism 203 meshes with the AE gear 218. Pin 219 formed on the back of AE gear 218
The a (AE means) reaches a position where it can be engaged with the cam surface 218a (AE means) formed on one arm of the blade drive lever 219 (blade drive member). The blade drive lever 219 has its fulcrum supported by a support pin 221 on a magnet interlocking arm 220 (support arm), and is given a turning tendency in the clockwise direction in FIG. 11 by a spring 222 hung on the other arm. A drive pin 223 for opening and closing two blades 224a and 224b forming a vario-type shutter 224 is fixedly planted on the other arm of the blade drive lever 219. Then, on the path of the drive pin 223 in the direction of opening the blades 224a, 224b, a restricting member 225 for restricting the opening diameter when the shutter is opened is displaced, for example, in conjunction with a zoom ring (not shown). It is provided.
In addition, an AE switch 226 that is turned on and off by the rotation of the blade 219 is arranged near the other arm of the blade drive lever 219.

The small-diameter gear 218b integrated with the AE gear 218 has a locking gear 227.
Are engaged. The gear ratio between the small diameter gear 218b and the locking gear 227 is 1: 2. That is, while the AE gear 218 makes one revolution, the locking gear 227 makes one half revolution.

The rear surface of the locking gear 227 is shown in FIGS.
A cam portion 228 having a shape as shown in is formed. The cam portion 228 (holding means) engages a pin 220a (holding means) fixedly attached to the magnet interlocking arm 220 to restrict the movement thereof, and the guide portion 228 along the peripheral surface of the locking gear 227.
a, a locking portion 228b formed in a part of the locking portion 228b so as to project inward, and the locking portion 228b as viewed from the rear surface of the locking gear 227 (that is, FIG. 12A to FIG. In ()), a counterclockwise direction is formed from a position in the vicinity of the center to a rotation center of the locking gear 227 and a locking portion 228c (holding means). The locking gear 227 further includes an initial position detection cam (not shown), and the switch 233 provided in the vicinity of the locking gear 227 is turned off by the detection cam to detect the initial position. Magnet interlocking arm 22
0 is given a turning tendency in the clockwise direction in FIG. 11 by a spring 229 about a support cylinder 220b fitted to a support shaft (not shown). An armature 232 is attached to a position of the magnet interlocking arm 220 facing the magnet 230 via a spring 231 that is compressed when the magnet interlocking arm 220 is moved to the overcharge position.

Next, the operation of the third embodiment having such a configuration will be described with reference to FIGS. 12 (A) to (F) and FIG.

First, by pressing down the shutter release button,
When the first-stage release switch is turned on, the motor 201 is rotated in the normal direction and the magnet 230 is energized to be in an excited state. The rotational driving force of the motor 201 is transmitted to the differential gear mechanism 203 via the sun gear 204, but since the AF gear 208 is loaded by the click spring 210, the internal gear 207 does not rotate, Rotation is transmitted to carrier 205 and AE gear
218 rotates.

Now, in the initial state, the AE gear 218 and the locking gear 227 are in the rotational position relationship shown in FIG. 12 (A), the magnet interlocking arm 220 is in the overcharge position, and the pin 220a of this arm 220 is engaged. It is locked by the locking portion 228c of the stop gear 227. Further, the blade drive lever 219 is biased by the spring 222 and abuts on the opening diameter restricting member 225, and the blades 224a and 224b are in the open state.

From this initial state, the carrier 205 rotates in the direction of the arrow, and as shown in FIG. 12 (A), the AE gear 218 rotates in the direction of the arrow a, as shown in FIG. 12 (B). As shown in FIG.
The magnet interlocking arm 220 is returned between b and the locking portion 228c by the amount of overcharge due to the repulsive restoring force against the contraction force of the spring 231. Then, in the state shown in FIG. 12 (B), the magnet interlocking arm 22
The pin 220a of 0 is sandwiched between the locking portion 228b and the locking portion 228c of the locking gear 227, and the rotation of the locking gear 227, that is, the rotation of the carrier 205 is blocked in both directions.

When the rotation of the carrier 205 is blocked, the AF gear 208 overcomes the pressing force of the click spring 210 and rotates by the rotation of the internal gear 207. At this time, the motor 201 rotates in either forward or reverse directions depending on the focus state, and the movement of the lens frame 212 for focusing by the rotation of the AF gear 208 is performed in either the extending or retracting direction. . The moving direction and position of the lens frame 212 are detected by reading the reflection pattern formed on the back surface of the AF gear 208 with two sets of photo reflectors of the rotation detector 216.

When focus is adjusted by matching the output of the rotation detector 216 with the output of a distance measuring unit (not shown), the magnet 230 is then de-excited and the magnet interlocking arm 220
Due to the tendency of the spring 229 to rotate, it rotates in the direction opposite to the arrow e direction shown in FIG. Then, as shown in FIG. 12 (C), the pin 220a falls to the base of the locking portion 228c near the center of the locking gear 227, and the locked state sandwiched between the pin 220a and the locking portion 228b is released. It Then pin 22
Since the blade drive lever 219 also descends at the portion 1, the contact between the pin 218a of the AE gear 218 and the cam surface 219a of the blade drive lever 219 is released. When the locked state is released, the AF gear 208, which has a heavy load, stops rotating again, and the AE
The gear 218 will be able to rotate.

Therefore, if the second-stage release switch is turned on at this time, the motor 20
The positive rotation of 1 causes the AE gear 218 to start rotating in the direction of arrow a. When the AE gear 218 is rotated about half a turn from the state of FIG. 12 (C), the pin 218a again contacts the cam surface 219a, and then the pin 218a again causes the blade drive lever 219 to move in the direction of arrow c. Rotate and push it up. Then, as shown in FIG. 12 (D), a magnet interlocking arm
The 220 is again charged to the overcharge position, and the armature 232 is again attracted to the excited magnet 230. By the movement of the pin 220a at this time, the locking portions 228b, 2
Since 28c is located away from the pin 220a, the movement of the pin 220a is not hindered.

Further, the AE gear 218 rotates in the direction of arrow a to move the pin 218a, and the pin 218a moves to the cam surface 219a of the blade drive lever 219.
If you lose the upward pressure on the pin,
The positions of 220a and 221 are lowered by the amount of overcharge. After this,
When the AE gear 218 further rotates, the cam surface 219a is attached to the pin 218a.
The blade drive lever 219 abutting on the track 218 follows the movement of the pin 218a due to the rotation habit of the spring 222, and moves in the direction of the arrow d (first
12 (see FIG. 12C). The rotation of the blade drive lever 19 causes the blades 224a and 224b of the shutter 224 to rotate in the opening direction, but prior to the actual opening of the blades 224a and 224b, the AE
The switch 226 is changed from on to off, and exposure control is started. Then, as shown in FIG. 12 (E), the AE gear 218 is further rotated, whereby the blades 224a of the shutter 224,
224b gradually opens wide to expose. Feather
224a and 224b are opened at the position where the drive pin 223 contacts the regulation member 225. The opening diameter of the blades 224a and 224b can be changed by changing the position of the regulating member 225. Then, when an appropriate exposure signal is output from the AE control circuit (not shown), the magnet 230 is de-excited again, the magnet interlocking arm 220 is rotated by the urging force of the spring 229, and the blades 224a and 224b are closed to expose. finish. After the end of the exposure, the AE gear 218 rotates in the direction of arrow a by the normal rotation of the motor 201, the pin 218a again faces the cam surface 219a of the blade drive lever 219, and the blade drive lever 219 moves to a not-shown contact surface. The drive pin 223 is rotated in the direction of arrow c while abutting the base of the drive pin 223. This movement of the blade drive lever 219 causes the magnet interlocking arm 220 to pass through the support pin 221.
Is charged by rotating in the direction of arrow e against the biasing force of the spring 229, returning to the initial state of FIG. 12 (A) and stopping.

Also in this embodiment, the shutter of the single-lens reflex camera can be realized by using it in combination with another light shielding member 63 and controlling it at the timing shown in FIG.

In the third embodiment, since the AE gear 218 pivotally supported is used, the driving force is small and the space is small.

Next, a fourth embodiment of the present invention will be described with reference to the drawings starting from FIG.

This embodiment is shown in FIG.
The configuration is substantially similar to that of the third embodiment shown in the figure. Therefore, in FIG. 14, the same members as those shown in FIG. 11 are designated by the same reference numerals, and detailed description thereof will be omitted.
The members similar to and corresponding to the members shown in FIG. 11 have the three-digit numerical code “2” at 100 shown in FIG. 11 replaced by “3”.

The blade drive lever 319 (blade drive member) is given a turning tendency in the counterclockwise direction in FIG. 14 by a spring 322 that is hooked between one arm and the immovable member. That is, in this embodiment, the shutter blades 224a and 224b are the blade drive lever 3
Due to the turning habit of 19, the drive pin 223 urges it in the closing direction. A pin 318a formed on the back surface of the AE gear 318 can be engaged with a gum surface 319a formed on one arm of the blade drive lever 319.

In addition, on the back surface of the locking gear 327 that meshes with the AE gear 318,
A cam portion 328 having a shape as shown in FIGS. 15A to 15F is formed. This cam portion 328 (holding means) is also the third
As in the case of the embodiment, the pin 220a (holding means) fixedly fixed to the magnet interlocking arm 220 (support arm) is locked to restrict its movement, and the guide along the peripheral surface of the locking gear 327 is used. A portion 328a, a locking portion 328b formed in a part of the locking portion 328b so as to project inward, and a portion of the locking portion 328b that is located in the vicinity of the counterclockwise side when viewed from the rear side of the locking gear 327, A locking portion 328c formed around the rotation center of the locking gear 327, and a locking portion integrally formed with the locking portion 328c (holding means) and having substantially the same cam shape and shifted by approximately 90 °.
It consists of 328d.

The other structure is similar to that of the third embodiment. Further, the AF transmission system after the carrier 205 is not shown in FIG.

Next, the operation of the fourth embodiment will be described with reference to FIGS. 15 (A) to (F).
It will be described with reference to FIG.

In the initial state shown in FIG. 15 (A), the magnet interlocking arm 220 is at the overcharge position, and the arm 2
The pin 220a of 20 is locked by the locking portion 328c of the locking gear 327, the blade drive lever 319 is pushed against the biasing force of the spring 322 by the pin 318a on the AE gear 318, and the blade 22 of the shutter 224 is pressed.
4a and 224b are open.

Now, when the carrier 205 rotates in the direction of the arrow in FIG. 14,
As shown in FIG. 15 (A), the AE gear 318 rotates in the direction indicated by the arrow a, and as shown in FIG. 15 (B), the pin 220a of the magnet interlocking arm 220 has locking portions 328b and locking portions 328b. The magnet interlocking arm 220 is returned to the charged amount by the amount of overcharge due to the repulsive restoring force against the elastic force of the spring 231. Then, in the state shown in FIG. 15B, the pin 220a (holding means) of the magnet interlocking arm 220 is sandwiched between the locking portion 328b and the locking portion 328c of the locking gear 327, and the locking gear 327 is held. Rotation of the carrier 205
Rotation is blocked in both directions. When the rotation of the carrier 205 is blocked, the AF drive system shown in the third embodiment operates.
Then, when the focus is adjusted, the magnet 230 is in a non-excited state, and the magnet interlocking arm 220 is rotated by the spring 229, so that the direction of the arrow e (see FIG. 15 (F)).
It rotates in the opposite direction. Then, as shown in FIG. 15 (C), the pin 220a has a locking portion 328 near the center of the locking gear 327.
It falls to the base of c, and the locked state sandwiched with the locking portion 328b is released. At this time, the blade drive lever 319 also lowers at the pin 221 portion, so that the blades 224a and 224b are closed. When the locked state is released, the AF drive system with a heavy load stops rotating, and the AF gear 318 can rotate.

Then, if the second-stage release switch is turned on, the AE gear 318 starts to rotate in the direction of arrow a by the normal rotation of the motor 201 for the exposure control. When the AE gear 318 further rotates from the state of FIG. 15 (C), the blade drive lever 319 follows the pin 318a of the AE gear 318 and is indicated by the arrow c.
When the AE gear 318 is rotated about 1/4 turn in the direction, the pin 220a of the magnet interlocking arm 220 is locked by the locking portion 3
It is pushed up by the cam surface of 28d, the magnet interlocking arm 220 is charged to the overcharge position again, and the armature 232 is attracted to the magnet 230 again excited, as shown in FIG. 15 (D). After that, when the engagement between the pin 220a and the cam surface of the locking portion 328d is released, the position of the pin 220a is lowered by the amount of overcharge at this point.

Further, when the AE gear 318 rotates in the direction of arrow a, the pin 3
18a moves, contacts the cam surface 319a of the blade drive lever 319, and rotates the blade drive lever 319 in the arrow d direction (see FIG. 15C) against the biasing force of the spring 322. Although the blades 224a and 224b are rotated in the opening direction by the rotation of the blade drive lever 319, the AE switch 226 is turned from ON to OFF prior to the actual opening of the blades 224a and 224b, and the exposure control is started. Then, as shown in FIG. 15 (E), the AE gear
As the 318 rotates further, the blade drive lever 319
Is rotated in the direction of arrow d, the blade 2 of the shutter 224
24a and 224b gradually open wide to expose. Then, when an appropriate exposure signal is output from the AE control circuit (not shown), the magnet 230 is again de-energized, the magnet interlocking arm 220 is rotated by the biasing force of the spring 229, and the blades 224a and 224b are closed and exposed. To finish. After the exposure is completed, the AE gear 318 is again rotated by the arrow a due to the normal rotation of the motor 201.
When rotated in the direction, the locking gear 327 rotates and the locking portion 328c
After the pin 220a of the magnet interlocking arm 220 is pushed up by the cam surface of the above to rotate the magnet interlocking arm 220 in the direction of the arrow e to charge it to the overcharge position, the AE switch 233 is turned off to stop the motor 201, and FIG. (A)
Return to the initial state shown in.

In this embodiment, since the opening operation of the blades 224a, 224b of the shutter 224 is performed by the driving force of the motor 201,
Stable shutter operation.

[Effects of the Invention] As described above, according to the present invention, there is no need for mechanical interlocking with the camera body side, and with a simple structure,
It is possible to provide the lens shutter mechanism which is in the fully open state in the initial state.

[Brief description of the drawings]

1 is an exploded perspective view of a lens shutter mechanism showing a first embodiment of the present invention, FIG. 2 is a view showing an optical system of a single lens reflex camera to which the present invention is applied, and FIG. 1 is a time chart for explaining the operation of the embodiment shown in FIG. 1, FIG. 4 is a plan view of the AE cam and regulating cam in FIG. 1, and FIG. 5 is a lens showing a second embodiment of the present invention. 6 is an exploded perspective view of the shutter mechanism, FIG. 6 is an enlarged perspective view showing the configuration of the peripheral portion of the planetary clutch in FIG. 5, and FIGS. 7 (A) and 7 (B) are the same as in FIG. FIG. 8 is a front view showing a shutter provided between the flanges of the lens holding frame in a closed state and an opened state, respectively. FIG. 8 is a front view showing the shutter drive mechanism in FIG. A) to (E) are operations showing the relationship between the AE gear and the blade drive lever in FIG. 10, FIG. 10 is a time chart for explaining the operation of the embodiment shown in FIG. 5, FIG. 11 is an exploded perspective view of the lens shutter mechanism showing the third embodiment of the present invention, and FIG. 11A to 11F are operation diagrams showing the relationship between the AE gear and the blade drive lever in FIG. 11, and FIG. 13 is a time chart for explaining the operation of the embodiment shown in FIG. FIG. 14 is an exploded perspective view of a lens shutter mechanism showing a fourth embodiment of the present invention, and FIGS. 15 (A) to (F) are relationships between the AE gear and the blade drive lever in FIG. FIG. 16 is a time chart for explaining the operation of the embodiment shown in FIG. 14 described above. 11,71,201 …… Motor 25 …… AE cam Gear (cam member) 26 …… AE cam 35,92,224 …… Shutter 35a, 35b, 92a, 92b, 224a, 224b …… Shutter blade 39,108,219,319 …… Blade drive lever 39a, 95,223 ...... Drive pin 41,107,220 …… Magnet interlocking arm (support arm) 44,111,230 …… Magnet 49 …… Regulation cam (holding means) 61 …… Lens shutter

Claims (1)

(57) [Claims] 1. A shutter blade for opening and closing a photographing lens opening, wherein the shutter blade is in a predetermined open state in an initial state before the start of photographing, and after being fully closed according to a photographing operation,
In a lens shutter mechanism of a camera that performs an opening / closing operation for photographing exposure, a blade drive member that opens and closes a shutter blade by swinging, and a stationary member that is pivotally supported by the stationary member and that swings the blade drive member. A first position for movably supporting the shutter blade and a second position for closing the shutter blade;
To a position, an AE means for swinging the blade driving member to control the opening amount of the shutter blade, an electric drive source for driving the AE means, and the supporting arm Holding means for mechanically holding in the first position, and, in the initial state before the start of imaging, mechanically holds the support arm in the first position by the holding means, Further, the lens shutter mechanism of the camera, characterized in that the blade driving member is swung to a position where the shutter blade is brought into a predetermined open state by the AE means so that subject light can pass through the photographing lens. .