JPH01158420A - Lens shutter mechanism for single-lens reflex camera - Google Patents

Abstract

PURPOSE:To simplify a mechanism by providing a driving source for a lens shutter on a lens side and eliminating charge from the side of a camera main body. CONSTITUTION:A vane driving lever 39 connecting shutter vanes 35a and 35b is supported so as to rock freely by means of a supporting arm 41 turnably journaled by a fixed member. When the supporting arm 41 is turned by the driving source, the vane driving lever 39 rocks in the direction in which the shutter vanes 35a and 35b are closed. A magnet 44 regulates the turn of the supporting arm 41, and in an initial state before photographing starts, the supporting arm 41 is held in the attracting or overcharging position of the magnet 44. Thus, mechanical interlocking with the side of the camera main body is not needed to simplify the constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lens shutter mechanism used in a -eye reflex camera (hereinafter abbreviated as -eye reflex camera).

[Prior Art] As is well known, the driving force for the lens shutter of an eye-reflex camera is charged from the camera body. I was trying to charge it. However, such operations require extremely complicated procedures.

Therefore, the present applicant previously disclosed in Japanese Patent Publication No. 58-34818 that the shutter blade of the lens shutter is opened and closed using a shutter opening ring and a shutter closing ring.
We have proposed a lens shutter for single-lens reflex cameras in which the opening and closing operations of the lens shutter can be performed automatically in conjunction with the shirt release on the camera body side.

[Problems to be Solved by the Invention] However, even in the lens shutter proposed by the applicant, since the shutter is charged by an aperture lever inside the camera body, the mechanism must be complicated accordingly. Ta.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a lens shutter mechanism for an eye reflex camera, which eliminates the above-mentioned problems, provides a drive source for the lens shutter on the lens side, eliminates the need for charging from the camera body side, and simplifies the mechanism. is to provide.

[Means and effects for solving the problem] In the lens shutter mechanism of the present invention, the blade drive lever to which the shutter blade is connected is swingably supported by a support arm rotatably supported by a stationary member. When the support arm is rotated by the drive source, the blade drive lever swings in the direction in which the shutter blade closes. The rotation of the support arm is regulated by a magnet, and in an initial state before the start of imaging, the support arm is held at a magnet attraction position or an overcharge position.

[Example] Prior to a detailed explanation of the present invention, the basic operation of a single-lens reflex camera to which the present invention is applied during photographing will be explained using FIG. In FIG. 2, the photographer composes a photograph by capturing the subject light that passes through the photographic lens 60, is reflected by the movable reflection mirror 65, and then passes through the pentaprism 66 and finder lens 64 and enters the photographer's eye 67. Decide or focus. Therefore, at this stage, the lens shutter 61 of the photographic lens 60 is open to guide the subject light to the finder optical system, and the film 62 is kept shielded from the subject light by the light shielding member 63 so as not to be exposed to light.

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

Hereinafter, a lens shutter mechanism for a single-lens reflex camera according to the present invention will be explained based on an exploded perspective view of a first embodiment shown in FIG. In FIG. 1, a motor 11 is rotatable in both forward and reverse directions by a control signal from a control circuit (not shown), and the rotation of a drive gear 12 provided on its output shaft is transmitted to a gear 15 via gears 13 and 14. It is meant to be transmitted.

A reflector plate 28 having a pattern of white (reflective surface) and black (non-reflective surface) is fixed to the gear 13.
Pulses corresponding to the rotation of the motor 11 are detected by a photoreflector 27 placed opposite to the motor 11 .

After gear 15, the transmission system is divided into two systems, and one transmission system includes gears 16 and 17, a one-way clutch 18 fitted in a notch 17a formed in gear 17, and one-way clutch 18 that is fitted in a notch 17a formed in gear 17. This is an automatic focus transmission system (hereinafter referred to as AF transmission system) consisting of a ratchet 19 and an AF cam member 20 that are coaxially integrated with each other.

In the one-way clutch 18 of this AF transmission system, the gear 17 is rotated counterclockwise (the rotation direction is on the upper side of FIG. 1).

In other words, when the gear 17 rotates in the direction seen from the subject side (the same applies hereinafter), it engages with the notch 17a of the gear 17 and transmits rotation, but when the gear 17 rotates clockwise, it slips within the notch 17a. rotation is not transmitted.

The other transmission system includes a one-way clutch 21 that fits into a notch 15a formed in the gear 15, and a one-way clutch 21 that fits into a notch 15a formed in the gear 15.
This is an automatic exposure transmission system (hereinafter referred to as the AE transmission system) consisting of a gear 22, gears 23 and 24, and an AE cam gear 25, which are integrally coaxial with each other. An AE cam 26 is integrally formed on the lower surface of the AE cam gear 25 around the exposure opening, and further,
A regulating cam 49 is integrally formed on the outside of the AE cam 26 at a position equidistant from the optical axis O and extending approximately half the circumference.

The one-way clutch 21 of this AE transmission system engages with the notch 15a of the gear 15 to transmit rotation when the gear 15 rotates clockwise, but when the gear 15 rotates counterclockwise, the notch 15a and does not transmit rotation.

A locking pawl 29 is engaged with the ratchet 19 of the AF transmission system under the biasing force of a spring. A protrusion 20a is provided on the side of the AF cam member 20.

20b is formed, and the protrusion 20a turns on the AF switch 30 at the initial position facing the AF switch 30, and the protrusion 20b biases the AF cam member 20 in the opposite direction to the rotational direction. The AF cam member 20 is stopped at the initial position by being locked by the brake spring 31 that is provided.

A three-dimensional cam surface 20c is formed on the lower surface of the AF cam member 20. This three-dimensional AF cam surface 20c is connected to the photographing lens (
It faces an implant pin 33a on a shutter case 33 that is integrated with a lens holding cylinder 32 that holds a lens (not shown). The shutter case 33 integrated with the lens holding cylinder 32 has guide members 40c and 40d attached to the base plate 40 engaged with its guide groove 33C133d in a direction along the optical axis 0 (hereinafter referred to as the optical axis direction). ), and is always biased by the spring 34 toward the subject at the top in the figure, so when the AF cam member 20 rotates, the AF cam surface 2
The pin 33a is in sliding contact with 0c, and the shutter case 33 is in AF mode.
It moves in the optical axis direction according to the shape of the cam surface 20c.

The shutter case 33 has two blades 35a forming a vario-type shutter 35 on its lower surface side.

35b is attached and supported by support pins 37 and 38 implanted in the shutter case 33. A drive pin 39a is fixed to one end of the blade drive lever 39 from above in the long hole 33b bored in the shutter case 33.
passes through the drive pin 39a, and the drive pin 39a fits into the long drive hole of the blades 35a and 35b. The drive pin 39a fitted into this long drive hole further extends in the optical axis direction and is locked to a regulating surface 51a of a regulating arm 51 disposed inside the zoom ring 50. The base end of the regulation arm 51 is connected to the shutter case 3
It is rotatably supported by a boss provided at a position 3 (not shown). This regulating arm 51 is biased in one direction by a spring 52, and its tip 51b is in contact with a cam surface 50a on the inner circumference of the zoom ring 50. Therefore, when the zoom ring 50 is rotated relative to the shutter case 33, which is stationary in the rotational direction, the tip 51b of the regulating arm 51 moves toward the cam surface 50.
a, the position of the regulating surface 51a of the regulating arm 51 is displaced according to the shape of the cam surface 50a, thereby regulating the open side position on the passage in which the driving pin 39a moves.

A magnet interlocking arm 41 is attached to a boss (not shown) of the main plate 40.
is rotatably attached, and the blade drive lever 39 is rotatably disposed around a pin 41a fixed to the tip of the arm 41. Blade drive lever 3
9 is constantly urged counterclockwise by a spring 42.

Then, a pin 39 is attached to the other end of this blade drive lever 39.
b 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,
This causes the position of the drive pin 39a to be displaced.

The magnet interlocking arm 41 is biased counterclockwise by a spring 43. In addition, magnetic interlocking arm 4
An armature 45 that can be attracted to a magnet 44 is attached to the tip of the armature 41 with a screw 47 via a coil spring 46. It is designed to be attracted in the opposite direction. and,
A pin 41b is attached to the upper surface of the magnet interlocking arm 41 in the figure.
is fixedly installed, and the pin 41b comes into contact with the regulating cam 49 when the AE cam gear 25 is rotating, which faces the regulating cam 49. In this state, the magnet interlocking arm 41 is The armature 45 is in an overcharge position where the coil spring 46 is compressed and the armature 45 is brought into pressure contact with the magnet 44, and rotation is restricted while the biasing force of the spring 43 is maintained. Therefore, when the magnet interlocking arm 41 is subsequently attracted to the magnet 44 via the armature 45, as will be described later,
The adsorption state is maintained.

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

Next, regarding the operation of the embodiment shown in FIG.
The time chart shown in the figure and the AE cam 26 shown in Fig. 4.
This will be explained with reference to the shape of the regulating cam 49.

First, the motor 11 is first controlled by a control signal from the control circuit.
is driven forward. Then, since the drive gear 12 rotates clockwise, its driving force is transmitted to the gear 15 via the gears 13 and 14, and the gear 15 rotates counterclockwise. It is further transmitted to gear 17 via gear 16, and gear 17 rotates counterclockwise. When the gears 15 and 17 rotate counterclockwise, the driving force of the motor 11 is not transmitted to the AE transmission system from the one-way clutch 21 to the AE cam gear 25, but is transmitted only to the AP transmission system, and is transmitted to the one-way clutch. Ratchet 19 and AF cam member 20 integrated with 18
rotates counterclockwise.

When the AF cam member 20 rotates through a certain angle, the protrusion 20
a separates from the AF switch 30 and turns off the switch 30. Then, the photoreflector 27 starts counting the amount of rotation of the gear 13. Furthermore, when the AF cam member 20 rotates, the shutter case 33 integrated into the lens holding cylinder 32 is retracted by the AF cam surface 20c at the lower end thereof. While the AF cam member 20 is rotating, the ratchet 19 is rotated by being advanced one step at a time by the locking pawl 29. When the photoreflector 27 counts the number of pulses corresponding to the retraction amount of the shutter case 33 appropriate for the AP information obtained from another AF detection device (not shown), the control circuit applies a short brake to the motor 11, and then , the motor 11 is reversed.

When the motor 11 is driven in reverse, the drive gear 12 rotates counterclockwise, so the gears 15.17 rotate clockwise. Therefore, in this case, the driving force of the motor 11 is transmitted to the AE transmission system from the - direction 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. Since the ratchet 19 integrated with the clutch 18 may be restricted from rotating in this direction by the locking pawl 29, the AF cam member 20 does not rotate and rotates in the shutter case 33 integrated with the lens holding cylinder 32. Maintain renormalization position.

When the driving force of the motor 11 is transmitted to the AE transmission system, the AE cam gear 25 rotates counterclockwise, and the AE cam gear 25 rotates counterclockwise.
The AE cam 26 and the regulation cam 49, which are integrated with the cam 5, also rotate in the same direction. As will be described later, since the magnet interlocking arm 41 is held in a charged state (overcharge position), the tip 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 in

Thereafter, the blade drive lever 39 rotates according to the shape of the cam surface of the rotating AE cam 26. AE cam 2
6 and the regulating cam 49 when viewed from above, that is, from the subject side, as is clear from FIG. 4, in the initial state, the pin 39b of the blade drive lever 39
The pin 41b of the magnet interlocking arm 41 faces the intermediate initial position 49a of the regulating cam 49. Thereafter, when the AE cam 26 and the regulation cam 49 rotate counterclockwise, the pin 39b moves away from the optical axis 0 from a state in which it contacts the circumferential cam surface 26b close to the tip axis O. Since the blade drive lever 39 comes into contact with the inclined cam surface 26c, the blade drive lever 39 begins to rotate clockwise. Therefore, the drive bin 39a moves through the elongated hole 33b of the shutter case 33 in a direction approaching the optical axis 0, thereby closing the blades 35a and 35b. Then, the light shielding member 63 and the movable reflection mirror shown in FIG. 2 are opened by a mechanism not shown, and the finder optical system is switched to the photographing optical system.

By the way, the pin 41b of the interlocking arm 41 is still on the regulating cam 49 and maintains a charged state, but at this point, the magnet 44 is excited by electricity, and the interlocking arm 41 is attracted to the magnet 44 via the armature 45. Then, as the AE cam gear 25 rotates, the pin 4
1b is removed from the terminal 49c of the regulating cam 49. pin 41
b comes off from the regulation cam 49 and the magnet interlocking arm 41
Since the charged state is maintained even after the overcharging is canceled, the fulcrum position of the blade drive lever 39 remains fixed at a position far from the optical axis O.

The AE cam gear 25 further rotates counterclockwise, and the pin 39b of the blade drive lever 39 passes through the cam surface 26do at the farthest position from the optical axis O, and then comes into contact with the cam surface 26d, which has a shape that gradually approaches the optical axis 0. When the blades are in contact with each other, the blade drive lever 39 begins to rotate counterclockwise. Therefore, the drive pin 39a moves in a direction away from the optical axis 0, and as a result, the blades 35a and 35b of the shutter 35 begin to open, and exposure begins.

The AE switch 48 is initially in an on state, but is turned off by the protrusion 25a just before the start of exposure. Then, using this as a trigger, the control circuit starts AE integration. When the integration is finished and the control circuit outputs an exposure end signal, the magnet 44 releases the adsorption and holding of the interlocking arm 41, so the interlocking arm 41 rotates counterclockwise due to the biasing force of the spring 43. Blade drive lever 39
, and the drive pin 39a is moved toward the optical axis O all at once. This causes the blade 35a.

35b closes. In the case of long exposure, the rotation of the AE cam gear 25 is temporarily stopped with the pin 39b of the blade drive lever 39 located on the cam surface 26e closest to the optical axis O, and the appropriate exposure time elapses. Later again AE cam gear 25
rotates.

By the way, when changing the focal length, adjust the zoom ring 5 in advance.
Rotate 0 and set the position according to the focal length.

When the zoom ring 50 rotates, the tip 51 of the regulating arm 51
b 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 driving pin 39a changes.
The position on the open side of the passageway is restricted. Therefore, when the blades 35a, 35b are opened by the drive pin 39a, the drive pin 39a stops when it is regulated by the regulation surface 51a, and the maximum aperture aperture diameter at this time is determined by the regulation surface 51a according to the focal length. Determined by location.

The blade 35a is exposed for an appropriate time.

After 35b closes, the AE cam gear 25 further rotates and the magnet interlocking arm 41 is charged. That is, after the exposure is completed, the AE cam gear 25 further rotates, and the optical axis O is continuous with the cam surface 26e of the AE cam 26.
The pin 39b of the blade drive lever 39 is pushed in the direction away from the optical axis 0 by the inclined cam surface 26f moving away more steeply, and when the pin 39b reaches the cam surface 26g furthest away from the optical axis O, the driving pin 39a is a blade 35a.

35b is closed and in contact with the shutter case 33, a force that resists 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 is attached to the coil. Since the spring 46 is not compressed, it is pressed against the magnet 44 via the armature 45 and reaches the overcharge position.

After the interlocking arm 41 is charged, the AE cam gear 25 further rotates, and the pin 39b is attached to the cam surface 26 of the AE cam 26.
When the cam surface 26h steeply approaches the optical axis O from g, the pin 41b of the interlocking arm 41 reaches one end 49d of the regulating cam 49 and is locked to the same end 49d. Therefore, the charged state thereafter is maintained by the pin 41b coming into contact with the regulating cam 49 and moving while being regulated by the cam.

The AE cam gear 25 rotates roughly, and the blade drive lever 3
When the pin 39b of 9 reaches the cam surface 26h of the AE cam 26, the blade drive lever 39 begins to sharply rotate counterclockwise, and the drive pin 39a moves away from the optical axis O.
This opens the blades 35a and 35b of the shutter 35. Then, when the pin 39b reaches the cam surface 26b, the blade 35a.

35b is fully opened. This shutter blade 35a.

35b opens, the movable reflection 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 is switched from off to on, and the motor 11 is stopped by that signal, and the AE cam 26 is turned on.
The pin 39b of the blade drive lever 39 is reset to the initial position 26a, and the pin 41b of the interlocking arm 41 is reset to the initial position 49a of the regulating cam 49. Thereafter, the motor 11 rotates normally again and rotation is transmitted to the AF cam member 20, and the shutter case 33 is retracted in the direction toward the reset position by the AF cam surface 20c. and,
Immediately before the reset position, the AF switch 30 is switched from off to on, and a short brake is applied to the motor 11 in response to this signal. At this time, after the AF switch 30 is switched, the protrusion 20b of the AF cam member 20 comes into contact with the brake spring 31, and a brake is applied to the AF cam member 20, so that the AF cam member 20 stops at the initial position.

In this embodiment, the charged state of the shutter 35 is maintained directly by the regulating cam 49 on the AE cam gear 25, but it is of course possible to maintain the charged state using a separate member. be.

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

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

In FIG. 5, a main body 72 is equipped with a motor 71 as a drive source for autofocus and shutter drive.
A focusing frame 73 is fixed to the rear side of the camera with screws 74. This focusing frame 73 has a
A cashing mechanism 75 is provided. The focusing mechanism 75 includes a cylindrical AF cam member 76 that is rotatably attached to the focusing frame 73 around the optical axis O of the photographic optical system. A displacing cam surface 76a is formed.

The focusing mechanism 75 also includes a focusing drive gear train 77 that meshes with a gear portion formed on the outer circumference of the AF cam member 76, and a timing switch 78 that contacts the outer circumferential surface of the AF cam member 76. This timing switch 78 is a switch that detects the initial position of the cam member 76 at the start of focusing, and controls the amount of rotation of the cam member 76 in accordance with a signal from a photo ink club 86 (see FIG. 6). It is. Furthermore, the focusing frame 73 is provided with a shutter drive gear train 79 and a planetary clutch 80 located between both gear trains 77 and 79. A drive gear 81 serving as a 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 made up of two planetary gears 82 and 83 that are simultaneously engaged with the drive gear 81, and these gears are planetary and held by a bar 84. . Since the planetary 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 planetary lever 84 also rotate in the same direction, and one planetary gear 82 is connected to the focusing drive gear train 77.
mesh with. As a result, the AF cam member 76 rotates and focusing is performed. In addition, the output shaft 71a is
When rotated in the opposite direction, the other planetary gear 83 meshes with the shutter drive gear train 79 and drives the shutter drive gear train 79. At the tip of the output shaft 71a of the motor 71, there is a
A rotating member 85 in which slits are formed at one interval is fixed, and a photo interrupter 86 is arranged to sandwich the peripheral edge of this rotating member 85. This photointerrupter 86 counts pulses from the slit of the rotating member 85 when the motor 71 rotates, converts it into an electric signal, sends it to a control circuit (not shown), and controls 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 0 and a guide post 89°90 implanted in the main body 72. ing. A flange 91a of the front holding part 87a and a flange 91b of the rear holding part 87b of the lens holding frame 87 are provided parallel to each other and facing each other in a direction perpendicular to the optical axis 0. As shown in FIGS. 7(A) and 7(B), a vario-type shutter 92 formed from two blades 92a, 92b is disposed between the two flanges 91a, 91b. Rear holding part 87
A pin 93 is installed 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 urged backward by an elastic member (not shown), the rear holding part 87b is located inside the AF cam member 76 through the open lower part 2a of the main body 72, and the cam surface 76
The cam pin 93 is in contact with a.

As shown in FIGS. 7(A) and 7(B), the shutter 92 disposed between the two flanges 91a and 9lb has pins 94a and 94b implanted in the flange 91b.
A pair of blades 92a and 92b are rotatably supported. Further, each of the blades 92a and 92b has a long hole 96.
A and 96b are formed, and a drive pin 95, which will be described later, is fitted into the mutually overlapping portion of these elongated holes 96a and 96b. This drive bin 95 is directed toward the center of the opening 97 of the flanges 91a, 91b, that is, the optical axis 0 of the photographing optical system.
When the blades 92a and 92b close (see FIG. 7(A)), the openings 97 of the flanges 91a and 91b close.
, that is, the optical axis of the photographing optical system is 0.
When moving away from the blades 92a and 92b, the blades 92a and 92b open (see FIG. 7(B)).

A shutter frame 98 is arranged on the front side of the lens holding frame 87, and a shutter drive mechanism 99 is provided on the shutter frame 98. Further, a cover 100 covering the shutter drive mechanism 99 is attached to the front side of the shutter frame 98 with screws 101.

The shutter drive mechanism 99 has an AE cam gear 102,
The cam gear 102 is connected to the shutter drive gear train 79 via idler gears 103 and 104 and a connecting gear 105. As shown in Fig. 8, AE cam gear 1
A pin 102a is installed eccentrically from the rotation center of the cam gear 102 on the upper surface of the AE cam gear 102, and a cam surface 102b is formed on the lower surface of the AE cam gear 102. This cam 1
1j102b has a concave portion 102 over a certain angular range.
C is formed. A variable lead terminal of an AE switch 106 attached to the shirt shirt frame 98 is brought into contact with this cam surface 102b. Further, the shutter drive mechanism 99 has a magnet interlocking arm 107 and a blade drive lever 108. An intermediate portion of the magnet interlocking arm 107 is rotatably supported by a support shaft 109 implanted in the shirt shirt frame 98. At one end of the magnet interlocking arm 107, there is a spring 110a that tightens when the arm 107 is moved to the overcharge position.
An armature 110 is attached through the shaft, and the armature 110 faces an on-type magnet 111 fixed to the shirt shirt frame 98. At the other end of this magnet interlocking arm 107, an intermediate portion of a blade drive lever 108 is rotatably supported by a support shaft 112. The magnet interlocking arm 107 has a habit of rotating clockwise around the support shaft 109 due to the biasing force of the torsion spring 113a.
The blade drive lever 108 has a habit of rotating clockwise around the support shaft 112 due to the biasing force of the torsion spring 113b. Near one end of the blade drive lever 108 is the AE
Cam surface 1 that can come into contact with pin 102 a of cam gear 102
08a is formed.

Further, a drive pin 95 is installed at the other end of the blade drive lever 108 on the surface facing the shutter frame 98. The blade 92 of the shutter 92 is inserted through the through hole 115 formed in the flange 91a of the frame 87.
It penetrates through the elongated holes 96a and 96b of a and 92b.

Further, a regulating lever 116 for adjusting the amount of movement of the drive pin 95 is rotatably attached to the shirt shirt 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 opening regulating member 118 for regulating the opening diameter when the shutter is opened. Further, the other end 11 of the regulation lever 116
6b is the drive pin 9 as the regulation lever 116 rotates.
It is possible to enter the moving passage No. 5.

Next, regarding the operation of the second embodiment, FIGS.
This will be explained using the operation diagram shown in (E) and the time chart shown in FIG. In addition, in FIGS. 9(A) to 9(E), in order to make it easier to understand the movements of the magnet interlocking arm 107 and the blade drive lever 108,
3a and 113b are represented by ordinary springs.

When the motor 71 is rotated forward and the planetary gear 82 of the planetary clutch 80 engages with the focusing drive gear train 77, the AF cam member 76 is rotated via the focusing drive gear train 77.
rotates, and the pin 93 of the rear holding portion 87b pressed against the cam surface 76a of the cam member 76 moves following the displacement of the cam surface 76a. As a result, the lens holding frame 87
Focusing is performed by moving along the optical axis direction. 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 as the rotation of the cam member 76 starts, and in synchronization with this, the photo ink clubter 86 counts drive pulses. Then, when the count reaches a predetermined value, that is, when the amount of rotation of the AF cam member 76 reaches a predetermined value, the motor 71 stops and focusing ends.

Subsequently, the motor 71 starts rotating in reverse, and the shutter drive mechanism 99 starts driving. That is, as the motor 71 reverses, the planetary gear 83 of the planetary clutch 80 engages with and drives the shutter drive gear train 79. This driving force is transmitted to the idler gears 104 and 103 via the connection gear 105, and as a result, the AE cam gear 102 rotates in the direction of arrow B. In the initial state, FIGS. 8 and 9 (A)
In the state shown in , the armature 110 of the magnet interlocking arm 107 is attracted to the magnet 111 in the OFF state, and the blades 92a and 92b of the shutter 92 are in the seventh position.
It is open as shown in Figure (B). Furthermore, Figure 9 (
As shown in B), at the beginning of rotation of the AE cam gear 102, the blade drive lever 108 is pressed against the cam surface 108a by the pin 102a on the AE cam gear 102, and is moved counterclockwise against the biasing force of the torsion spring 113b. Rotate.

In this state, the drive pin 9 of the blade drive lever 108
Reference numeral 5 denotes a shutter blade 92a located at the lower end of the elongated hole 114 (see FIG. 8) near the optical axis 0.

92b closes. Note that the drive pin 95 reaches the lower end of the elongated hole 114 near the optical axis 0 and is connected to the support shaft 1 of the blade drive lever 10g.
12 is blocked, then the magnet interlocking arm 107 is given a slight counterclockwise rotational force about the support shaft 109, and the armature 110 is strongly pressed against the magnet 111, resulting in an overcharge. Pass position.

Then, as shown in FIG. 9(C), the AE cam gear 10
2 rotates further, the pin 102a moves away from the blade drive lever 108, so the blade drive lever 108 moves the pin 102a by the biasing force of the torsion spring 113b.
Rotate clockwise while following. As a result, the drive pin 95 of the blade drive lever 108 moves the long hole 114 toward the optical axis 0.
The blade 92a of the shutter 92 moves upward and away from the blade 92a of the shutter 92.

92b gradually opens. Here, the AE switch 106
The variable lead terminal is connected to the cam surface 102 of the AE cam gear 102.
Since it falls into the recess 102c of b, the AE switch 106 is turned on, and then the shutter blade 9 is turned on.
2a and 92b begin to open, the AE switch 10
The variable lead terminal No. 6 contacts the cam surface 102b again and
E switch 106 is turned off. Then, when the AE switch 106 is turned off, a shutter control circuit (not shown) is activated and an appropriate shutter opening time is determined. When the proper opening time is reached, that is, when 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 together with the blade drive lever 108 around the support shaft 109 as shown in FIG. 9(D) due to the biasing force of the torsion spring 113a. Therefore, the drive pin 95 of the blade drive lever 108 descends to the lower end position near the optical axis 0 of the elongated hole 114, and in conjunction with this, the blades 92a, 92b of the shutter 92
is closed.

After this, when the AE cam gear 102 is further rotated in the direction of arrow B by the drive of the motor 71, the blade drive lever 108 is pressed by the pin 102a that is in contact with the cam surface 108a, and the magnet The interlocking arm 107 resists the biasing force of the torsion spring 113a and rotates against the support shaft 1.
Rotate counterclockwise around 09. 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 drive lever 108 rotates clockwise, and the blades 92a and 92b of the shutter 92 are opened. Then, the drive of the motor 71 is stopped, and the state returns to the initial state shown in FIG. 9(A).

The regulating lever 116 is pressed by the opening regulating member 118 to regulate the amount of rotation in the counterclockwise direction. The other end 116b of the regulating lever 116 protrudes into the movement path of the drive pin 95 according to the amount of movement of this rotation, so the amount of movement of the driving pin 95 is regulated by the regulating lever 116, and the shutter blades 92a, 9
2b's maximum diameter is regulated.

Also in this embodiment, as described above, a lens shutter that performs the above series of operations and another light shielding member 63 such as a mirror shutter or a focal brain shutter are used.
(See FIG. 2) in combination and controlled at the timing shown in FIG. 10, it is possible to realize a shutter for an eye reflex camera.

In this embodiment, since a gear with 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
There is no need for mechanical locking using the regulating cam 49 (see FIG. 1) as in the first embodiment, the number of parts is reduced, and the structure is simple and inexpensive.

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 as follows.
The signal is transmitted to a differential gear mechanism 203 for AE/AF switching.

That is, a sun gear 204 of a 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) is rotatably disposed.

The sun gear 204 includes three planets that are rotatably supported by three support shafts 205a arranged and planted at equal angles on the front surface of the carrier 205 at positions protruding from the front surface of the carrier 205. Gear 206 is in mesh. These three planetary gears 206 mesh with internal teeth 207a of an internal gear 207. External teeth 207b are formed on the outer periphery of the internal gear 207.

Here, the operation of the differential gear mechanism 203 will be explained. Rotation of the sun gear 204 is transmitted to the planetary gear 206. When the rotation of the carrier 205 is restrained, the support shaft 205a is also immovable;
The planetary gears 206 each rotate around a, thereby causing the internal gear 207 to rotate. On the other hand, internal gear 207
When the rotation of
It revolves around the sun gear 204 along the inner teeth 207a of No. 7. Therefore, the support shaft 205a also has the planetary gear 206.
As a result, the carrier 205 rotates.

External teeth 207 of the internal gear 207 of the differential gear mechanism 203
b is meshed with the AF gear 208.

Since a click spring 210 is in pressure contact with the AF gear 208 at a position that does not interfere with the engagement with the internal gear 207, a click load is applied to the rotation of the AF gear 208. The AF cam surface 20 is located at the front end of the AF gear 208.
8a is formed, and the photographing lens 2 is formed on the same cam surface 208a.
An integral protrusion 212a is in contact with the lens frame 212 holding the lens 11. The lens frame 212 is supported movably in the direction along the optical axis O by fitting the protrusion 212b into the guide groove 213a of the rotation stopper 213. Since the portion 212a is pressed against the AF cam surface 208a, the lens frame 212 is extended or retracted in the optical axis direction when the AF gear 208 rotates. An appropriate number of reflective patterns (not shown) are formed on the back surface of the AF gear 208, and the AF gear 20 is located at a position facing the reflective patterns.
A rotation detector 216 consisting of two sets of photoreflectors for detecting the direction and amount of rotation of the rotor 8 is disposed.

On the other hand, the carrier 205 of the differential gear mechanism 203 is engaged with the AE gear 218. A pin 218a formed on the back surface of the AE gear 218 has reached a position where it can engage with a cam surface 219a formed on one arm of the blade drive lever 219. The blade drive lever 219 has its fulcrum supported by a support pin 221 on a magnet interlocking arm 220, and is given the ability to rotate clockwise in FIG. 11 by a spring 222 hung on the thin arm. The thin arm of this blade drive lever 219 has two blades 2 forming a vario-type shutter 224.
A drive pin 223 for opening and closing 24a and 224b is fixedly planted. A regulating member 225 for regulating the opening diameter when the shutter is opened is provided on the path of the drive pin 223 in the direction of opening the blades 224a, 224b.
For example, it is provided so as to be displaced in conjunction with a zoom ring (not shown). Further, an AE switch 226 is disposed near the narrow arm of the blade drive lever 219, and is turned on and off by rotation of the lever 219.

A locking gear 227 meshes with a small diameter gear 218b that is integrated with the AE gear 218. The gear ratio between the small diameter gear 218b and the locking gear 227 is 1:2. In other words, A
While the E gear 218 rotates once, the locking gear 227 rotates 1/
It rotates twice.

On the back side of this locking gear 227, there are
) A cam portion 228 is formed as shown in FIG.

This cam portion 228 engages a pin 220a fixed to the magnet interlocking arm 220 to restrict its movement, and includes a guide portion 228a along the circumferential surface of the locking gear 227 and a portion thereof toward the inside. The locking portion 228b is formed to protrude, and the vicinity of the counterclockwise side of the locking portion 228b when viewed from the back of the locking gear 227 (that is, in FIGS. 12(A) to 12(F)) From the position, this locking gear 2
27, and a locking portion 228C formed around the center of rotation of 27. The locking gear 227 further includes an initial position detection cam (not shown), and the initial position is detected by turning off a switch 233 provided near the locking gear 227 by this detection cam. The magnet interlocking arm 220 is a support cylinder 2 that fits into a support shaft (not shown).
A spring 229 provides a clockwise rotational habit about 20b in FIG. An armature 232 is attached to a position of the magnet interlocking arm 220 facing the magnet 230 via a spring 231 that contracts when the magnet interlocking arm 220 is moved to the overcharge position.

Next, the operation of the third embodiment configured as described above will be explained using FIGS. 12(A) to 12(P) and FIG. 13.

First, by pressing down the shirt release button,
When the second stage release switch is turned on, the motor 201 rotates in the forward direction and the magnet 230 is energized to be in an excited state. The rotational driving force of the motor 201 is provided by the sun gear 204.
However, since a load is applied to the AF gear 208 by the click spring 210, the internal gear 207 does not rotate and the carrier 20
The rotation is transmitted to the gear 5, and the AE gear 218 rotates.

Now, in the initial state, the AE gear 218 and the locking gear 227 are in the rotational positional relationship shown in FIG. It is locked by a locking portion 228C of the stop gear 227. Further, the blade drive lever 219 is biased by the spring 222 and comes into contact with the opening diameter regulating member 225, and the blades 224a and 224b are in an open state.

From this initial state, the carrier 205 rotates in the direction of the arrow, as shown in FIG. 12(A), and the AE gear 218 rotates in the direction of the arrow a, as shown in FIG. 12(B). Pin 220 on magnetic drive arm 220 as shown in FIG.
a falls between the locking portion 228b and the locking portion 228C, and due to the elastic return force that resists the tightening force of the spring 231, the magnet interlocking arm 220 returns to the charged amount by the overcharged amount. Then, in the state shown in FIG. 12(B), the pin 220a of the magnet interlocking arm 220 is held 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, rotation of the carrier 205 is prevented in both directions.

When the rotation of the carrier 205 is blocked, the AF gear 208
rotates by the rotation of the internal gear 207, overcoming the pressing force of the click spring 210.

At this time, the motor 201 rotates in either the forward or reverse direction depending on the focus state, and the rotation of the AF gear 208 causes the lens frame to rotate.
Movement for focusing 12 is performed in either direction, extending or retracting.

The moving direction and position of the lens frame 212 are detected by reading a reflection pattern formed on the back surface of the AF gear 208 with two sets of photoreflectors of the rotation detector 216.

When focus adjustment is performed when the output of the rotation detector 216 matches the output of a distance measuring section (not shown), the magnet 230 becomes de-energized and the magnet interlocking arm 220 moves to the first position due to the rotational behavior of the spring 229. Figure 9 (F)
It rotates in the direction opposite to the direction of arrow e shown in . Then,
As shown in FIG. 12(C), the pin 220a falls to the base of the locking part 228C near the center of the locking gear 227, and the locked state held between it and the locking part 228b is released. . At this time, the pin 221 drives the blade /<
-219 also goes down, so the contact between the pin 218a of the AE gear 218 and the cam surface 219a of the blade drive lever 219 is also released. When the locking state is released, the heavily loaded AF gear 208 stops rotating again, and the AE
Gear 218 can now rotate.

Therefore, if the second-stage release switch is on at this time, the motor 20 will continue to operate for exposure control.
1, the AE gear 218 begins to rotate in the direction of arrow a. From the state shown in Fig. 12 (C) above, the AE gear 218
When the blade has rotated approximately half a turn, the pin 218a comes into contact with the cam surface 219a again, and after this, the pin 218a again rotates the blade drive lever 219 in the direction of arrow C and pushes it up. Then, as shown in FIG. 12(D), the magnet interlocking arm 220 is charged again to the overcharge position, and the armature 232 is attracted to the magnet 230 which is again excited.

Note that the movement of the pin 220a at this time causes the locking portion 228 to
b and 228c are located far away from the pin 220a, so the movement of the pin 220a is not hindered.

Further, the AE gear 218 rotates in the direction of arrow a, and the pin 21
8a moves, and the same pin 218a is connected to the blade drive lever 219.
When the upward pressing force on the cam surface 219a is lost,
At this point, pin 220a.

The position 221 moves down by the amount of overcharge. Thereafter, when the AE gear 218 further rotates, the blade drive lever 219, which is in contact with the pin 218a at the cam surface 219a, follows the movement of the pin 218a in the direction of arrow d (see FIG. (see (C)).

This rotation of the blade drive lever 19 causes the shutter 224 to
The blades 224a, 224b rotate in the opening direction, but prior to the actual opening of the blades 224a, 224b, A゛E
The switch 226 changes from on to off and exposure control is started. Then, as shown in Figure 12 (E), AE
As the gear 218 further rotates, the shutter 2
The 24 blades 224a and 224b gradually open widely to perform exposure. The blades 224a and 224b are in an open state at a position where the drive pin 223 comes into contact with the regulating member 225. The apertures of the blades 224a and 224b when they are open can be varied by shifting the position of the regulating member 225. 1. When a proper exposure signal is output from the AE control circuit (not shown), the magnet 230 is de-energized again, 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. end.

After the exposure is completed, the motor 201 rotates forward to shift the AE gear 2.
18 rotates in the direction of arrow a, and the pin 218a again faces the cam surface 219a of the blade drive lever 219, and this blade drive lever 219 has the drive pin 22 on the surface (not shown).
30 Rotate in the direction of arrow C while making contact with the base. Due to this movement of the blade drive lever 219, the magnet interlocking arm 220 is rotated in the direction of arrow e against the biasing force of the spring 229 and is charged via the support pin 221.
It returns to the initial state shown in Figure (A) and stops.

In this embodiment as well, by using it in combination with another light shielding member 63 and controlling it at the timing shown in FIG. 13, it is possible to realize the shutter of a single-lens reflex camera.

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

Next, a fourth embodiment of the present invention will be described with reference to FIG. 14 and subsequent drawings.

In this embodiment, as is clear from FIG.
The structure is substantially the same as that of the third embodiment shown in FIG. Therefore, in FIG. 14, members that are the same as those shown in FIG. is “2” in the 100th place of the 3-digit numerical code shown in Figure 11.
is added instead of “3°.

The blade drive lever 319 is given a rotational habit in the counterclockwise direction in FIG. 14 by a spring 322 applied between its lower arm and a stationary member. That is, in this embodiment, the shutter blades 224a, 224b are urged in the closing direction by the drive pin 223 due to the rotational behavior of the blade drive lever 319. The AE gear 3 is attached to a cam surface 319a formed on one arm of the blade drive lever 319.
A pin 318b formed on the back surface of 18 can be engaged with the pin 318b.

Furthermore, a cam portion 328 having a shape as shown in FIGS. 15(A) to 15(F) is formed on the back surface of the locking gear 327 that meshes with the AE gear 318. This cam portion 328 is also connected to the magnet interlocking arm 22 in the same manner as in the third embodiment.
The guide portion 3 along the circumferential surface of the locking gear 327 locks the pin 220a, which has a value of 0, to restrict its movement.
28a, a locking portion 328b formed on a part thereof to protrude inward, and a position near the locking portion 328b on the counterclockwise side when viewed from the rear side of the locking gear 327. A locking portion 328C formed around the center of rotation of the locking gear 327, and a portion that is integral with the locking portion 328C and between the paths.
The locking part 3 is formed at a position shifted by approximately 906 in the cam shape.
It consists of 28d.

The rest of the structure is the same as that of the third embodiment. Also, regarding the AF transmission system of Chiaria 205 and later,
In this FIG. 14, illustration is omitted.

Next, the operation of this fourth embodiment is shown in FIGS. 15(A) to (F).
This will be explained with reference to FIG.

In the initial state shown in FIG. 15(A), the magnet interlocking arm 220 is in the overcharge position, and the pin 220a of this arm 220 is connected to the locking portion 32 of the locking gear 327.
8C, the blade drive lever 319 is pushed by the pin 3111a on the AE gear 318 against the biasing force of the spring 322, and the blades 224g, 22 of the shutter 224 are locked.
4b is in an open state.

Now, when the carrier 205 rotates in the direction of the arrow in FIG. 14, the AE gear 318 moves as shown in FIG.
15(B), the pin 220a of the magnet interlocking arm 220 is rotated in the direction shown in FIG.
8b and the locking portion 328C, and due to the elastic return force that resists the tightening force of the spring 231, the magnet interlocking arm 220 returns to an amount equal to the overcharged amount.

Then, in the state shown in FIG. 15(B), the pin 220a of the magnet interlocking arm 220 is held between the locking portion 328b and the locking portion 328C of the locking gear 327, and the rotation of the locking gear 327, i.e. , rotation of the carrier 205 is prevented in both directions. When the rotation of the carrier 205 is prevented, the AF drive system shown in the third embodiment is activated. When the focus is adjusted, the magnet 230 becomes de-energized, and the magnet interlocking arm 220 moves in the opposite direction to the direction of arrow e (see FIG. 15(P)) due to the rotational behavior of the spring 229. Rotate. Then, Figure 15 (C)
As shown in FIG.
The locked state held between the two parts and b is released. At this time, the blade drive lever 319 is also lowered at the pin 221, so the blades 224a and 224b are in a closed state. When the locked state is released, the heavily loaded AF drive system stops rotating, and the AE gear 318 becomes able to rotate.

If the second-stage release switch is on, the AE gear 318 begins to rotate in the direction of arrow a due to the normal rotation of the motor 201 for subsequent exposure control. When the AE gear 318 further rotates from the state shown in FIG. 15(C) above, the blade drive lever 319
18a and rotates in the direction of arrow C, and when the AE gear 318 reaches approximately 1/4 rotation, the pin 220a of the magnet interlocking arm 220 is pushed up by the cam surface of the locking portion 328d, and the 15th As shown in figure (D),
The magnet interlocking arm 220 is again charged to the overcharge position, and the armature 232 is again attracted to the energized magnet 230. After this, pin 220a
When the cam surface of the locking portion 328d disengages, the position of the pin 220a is lowered by the amount of overcharge at this point.

Furthermore, when the AE gear 318 rotates in the direction of the arrow a, the pin 318a moves and the cam surface 3 of the blade drive lever 319
19a, and rotates the blade drive lever 319 in the direction of arrow d (see FIG. 15(C)) against the biasing force of the spring 322. This rotation of the blade drive lever 319 causes the blade 224a to rotate.

224b rotates in the opening direction, but the blade 224a.

Prior to the actual opening of 224b, the AE switch 226 is turned from on to off, and exposure control is started. and,
As shown in FIG. 15(E), as the AE gear 318 further rotates, the blade drive lever 319 moves toward the arrow d.
As the blade 224 of the shutter 224 rotates in the
a and 224b are gradually opened wide and exposure is performed. Then, when a proper exposure signal is output from the AE control circuit (not shown), the magnet 230 becomes de-energized again, the magnet interlocking arm 220 rotates by the biasing force of the spring 229, and the blades 224a and 224b close. End exposure. After the exposure is completed, when the AE gear 318 rotates again in the direction of arrow a due to the forward rotation of the motor 201,
The locking gear 327 rotates, and the cam surface of the locking portion 328c pushes up the pin 220a of the magnet interlocking arm 220, rotating the magnet interlocking arm 220 in the direction of arrow e and charging it to the overcharge position, and then the AE switch is turned on. 233 to stop the motor 201 and return to the initial state shown in FIG. 15(A).

In this example, the blade 224a of the shutter 224.

Since the opening operation of the shutter 224b is performed by the driving force of the motor 201, stable shutter operation can be achieved.

[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 a lens shutter mechanism for an eye reflex camera can be provided with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a lens shutter mechanism for a single-lens reflex camera showing a first embodiment of the present invention, FIG. 2 is a diagram 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 regulation cam in FIG. 1, and FIG. 5 is a second embodiment of the present invention. FIG. 6 is an exploded perspective view of a lens shutter mechanism for a single-lens reflex camera showing an example.
An enlarged perspective view showing the configuration of the peripheral portion of the planetary clutch in the figure, and FIGS. 7(A) and (B) respectively show the shutter provided between the flanges of the lens holding frame in FIG. 5 above. 8 is a front view showing the shutter drive mechanism in FIG. 5 above, and FIGS. 9(A) to (F) are AE in FIG. 5 above. FIG. 10 is a time chart for explaining the operation of the embodiment shown in FIG. 5. FIG. 11 is a diagram showing the third embodiment of the present invention. Exploded perspective view of lens shutter mechanism for single-lens reflex camera, Figure 12 (A) ~
(P) is an operation diagram showing the relationship between the AE gear and the blade drive lever in FIG. 11, FIG. 13 is a time chart for explaining the operation of the embodiment shown in FIG. 11, and 14. The figures are exploded perspective views of a lens shutter mechanism for a single-lens reflex camera showing a fourth embodiment of the present invention, and FIGS.
(F) is an operation diagram showing the relationship between the AE gear and the blade drive lever in FIG. 14, and FIG. 16 is a time chart for explaining the operation of the embodiment shown in FIG. 14. 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 3
9.108,219,319...Blade drive lever 39a, 95.223...Drive pin 41.10
7,220......Magnet interlocking arm (support arm) 44.111.230...Magnet 49...Regulation cam

Claims (2)

[Claims] (1) A shutter blade that exposes the film surface by opening and closing; a blade drive lever that is connected at one end to the shutter blade; and a blade drive lever that is rotatably supported by an immovable member and that swings the blade drive lever. A support arm that is movably supported and swings the blade drive lever in a direction in which the shutter blade closes when rotated by a drive source, and a magnet that restricts the rotation of the support arm. A lens shutter mechanism for a single-lens reflex camera, characterized in that the support arm is held at the magnet attraction position or the overcharge position in an initial state before the start of photography. (2) A shutter blade that exposes the film surface by opening and closing, a blade drive lever with one end connected to the shutter blade, and a blade drive lever that engages with the other end of the blade and rotates to engage the blade drive lever. a cam member having a cam for changing the radial position of a portion of the blade; a drive source for rotating the cam; a support arm that supports and pivots the blade drive lever in a direction in which the shutter blade closes; a magnet that restricts the rotation of the support arm; a regulating cam that is provided without changing its position in the direction and that regulates the rotation of the support arm, and while the cam member makes one rotation in one direction, the film surface is The opening operation of the shutter blade while the rotation of the support arm is restricted by the magnet for exposure to the film, the closing operation of the shutter blade by releasing the restriction of the magnet, and the above operation in preparation for exposure of the film surface. A lens shutter mechanism for a single-lens reflex camera, characterized in that the shutter blade opens and closes while rotation of the support arm is restricted by a restriction cam.