JP2806640B2 - camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved double light shielding mechanism for a camera shutter such as a focal plane shutter.

[0002]

2. Description of the Related Art Heretofore, in a focal plane shutter, there has been a so-called double light-shielding shutter in which an aperture is shielded by both a front blade group and a rear blade group in order to increase light-shielding properties.

[0003] One type of double light-blocking shutter is a type in which the front blade group is moved to a position covering the aperture immediately after the end of the exposure when the rear blade group remains covered with the aperture. The structure was such that heavy light shielding was released.

However, recent cameras generally have a built-in motor drive device and perform a winding operation immediately after photographing is completed. Therefore, with this type of double light blocking shutter, double light blocking is performed immediately after photographing is completed. Because it was released, the meaning of shading diminished.

[0005] Another type of double light blocking shutter is:
It is suitable for a camera with a built-in motor and drive device, and after the end of shooting, the charging operation is performed while the rear blade group is held at a position covering the aperture. When the charging of the front blade group is completed, that is, the front blade group also covers the aperture. This is a method in which charging is completed in this state and the camera waits for a release operation.
Next, when the release operation is performed, the holding of the rear blade group held at the position covering the aperture is released, and after the rear blade group completes retreating from the aperture, the front blade group and the rear blade group travel at a predetermined timing in order. To complete the exposure.

[0006]

However, the conventional double light-shielding mechanism always performs the double light-shielding operation every time photographing is performed, so that the operation and the time required for the operation to stabilize after the operation are required. The frame speed will decrease.

SUMMARY OF THE INVENTION It is an object of the present invention to solve such a conventional problem and to release the double light blocking operation of the shutter during continuous photographing to increase the frame speed.

[0008]

A configuration for realizing the object of the present invention is arranged in a photographing optical path and provided in a finder.
A first mirror for guiding a light beam;
Guides the light flux to the photometric or focus detection device and
A second mirror that retreats outside the photographing optical path during exposure,
It has a front blade group and a rear blade group, and has a double shielding by the rear blade group.
A shutter capable of holding a light state and the second mirror
The rear wing group is linked to the retracting operation outside the shooting optical path.
And a double light blocking release mechanism for releasing the double light blocking state.
A camera comprising:

[0009]

1 to 16 show an embodiment of the present invention.

First, the overall structure of the camera according to this embodiment will be briefly described.

In the single-lens reflex camera of this embodiment, as shown in FIGS. 14 and 15, a main mirror (semi-transmissive mirror) 300 for guiding subject light to a finder optical system 304 is fixed, and the light is transmitted through the semi-transmissive mirror 300. The sub-mirror 305 that guides the subject light to the photometric and distance measuring device is a movable mirror, and retracts during photographing as shown in FIG.

These mirrors are housed in a mirror box formed integrally with a front plate (which constitutes a joint surface with a photographing lens). A shutter 200 of a heavy light shielding type is attached.

A shutter 200 shown in FIGS. 7 and 8 shows a state viewed from the front of the camera.
A shutter driving unit is disposed on the left side of the mirror box.

On the other hand, in this embodiment, a motor for driving the mirror and a motor for driving the shutter are shared, and the motor is disposed on the right side of the mirror box when the camera is viewed from the front. FIG. 1 shows the arrangement.

Further, in addition to the mirror driving motor, a film feeding mechanism driving motor and a shutter charging mechanism driving motor (not shown) are provided.

Power transmission from the motor arranged on the right side of the mirror box to the drive unit arranged on the left side of the mirror box of the shutter 200 is as shown in FIGS.
The information is transmitted via a mechanism provided on the bottom surface of the mirror box.

The shutter 200 is provided with a front blade group 202.
7 and 14 in which the upper half portion and the rear blade group 201 are overlapped in the upper half portion. The movable mirror is arranged, and as a result, the lower half portion is also double-shielded.

In FIG. 1, 10 is a front plate having a lens mounting mount and a mirror box, 20 is a motor for driving a mirror, and 30 is a reduction gear system having a gear train for reducing and transmitting the power from the motor 20 to a transmission shaft 40. , 50 is a worm gear fixed to the transmission shaft 40, 60 is a motor 2
0 is a cam gear having a worm wheel that is rotated counterclockwise through the worm gear 50 by one-way rotation, and a drive cam 61 that drives the mirror drive lever 70 is fixed inside the gear. A mirror driving lever 70 is rotatably held on a side wall of the front plate 10 by a shaft 71, and has a driving cam 6 of a cam gear 60 at an upper end.
Roller part 7 which comes into contact with the first cam 1 and is moved by the drive cam 61
The other end has a drive arm 73 for driving the sub mirror by contacting a drive pin 321 fixed to a sub mirror arm 320 (not shown in FIG. 1). The mirror drive lever 70 has an IF drive shaft 74 for driving the IF drive lever 80 for driving the shutter 200.
have. The mirror drive lever 70 rotated by the drive cam 61 rotates clockwise about the shaft 71 by the counterclockwise rotation of the cam gear 60. Reference numeral 80 denotes an IF drive lever, which is rotatably held by a shaft 81 on a cover plate (not shown) that covers the transmission shaft 40, the cam gear 60, and the mirror drive lever 70 on the side wall of the front plate 10. The IF drive shaft 7 of the mirror drive lever 70
A cam portion 82 that slides in contact with 4 is formed. That is, the IF drive lever 80 is connected to the mirror drive lever 70 (IF
The cam portion 82 receives the clockwise rotation of the drive shaft) and rotates counterclockwise. In addition, the lower end of the IF drive lever 80 has a vertical bent portion 83 that is bent to the back side of the paper surface,
The vertical bending portion 83 drives the IF pin 91 rightward for driving the shutter 200 by rotating the IF drive lever 80 counterclockwise.

3 and 4, reference numeral 90 denotes an IF lever provided on the bottom side of the mirror box. The IF lever 90 is rotatably held by a shaft 92 on a camera body (not shown).
An IF pin 91 that engages with the upright bent portion 83 is fixed to an arm portion 90 a of the drive lever 80 that extends toward the upright bent portion 83. In the IF lever 90, the IF pin 91 is driven by the IF drive lever 80, the arm 90b on the opposite side rotates clockwise, and moves the vertical bending portion 102 of the shutter release lever 100 described later to the left.

5 and 6, reference numeral 100 denotes a shutter release lever provided along the side surface of the mirror box opposite to the motor 20. The shutter release lever is rotatably supported by the shaft portion 101 on the side wall of the front plate 10. ing. Shutter release lever 10
0 has a vertical bent portion 102 which is engaged with the arm portion 90b of the IF lever 90 at the lower end portion, and has a connecting lever 1 which will be described later on the right end.
Bifurcated cam part 1 that fits and slides with ten connecting dowels 110a
03 has a spring hook 104 at the left end, and a tension spring 140 is hooked between the spring 03 and the spring hook 115 of the connecting lever 110. Since the tension spring 140 constantly applies a force in a direction in which the shutter release lever 100 and the connection lever 110 are pulled toward each other, the shutter release lever 100
Is always urged in the clockwise direction, and the connecting lever 110 is urged in the counterclockwise direction. Reference numeral 110 denotes a connection lever that rotates about a shaft 111, and a shutter release lever 100.
To drive the light-shield release lever 120 and the body release release lever 130 connected to both ends, respectively. The connection lever 110 is connected to the shutter release lever 10.
Arm 112 having a connecting dowel 110a that fits and moves with the cam portion 103 of No. 0, and an arm 1 that has a connecting dowel 110b that fits with the long hole cam portion 122 of the light blocking release lever 120
13 and an arm 114 having a connecting dowel 110c that fits with the long hole cam 132 of the body release release lever 130. When the shutter release lever 100 rotates counterclockwise, the cam portion 103 moves to the connecting lever 110.
The cam surface is formed so as to rotate clockwise. Reference numeral 120 denotes a light-blocking release lever for driving a double light-blocking mechanism of a shutter 200 described later.
It is rotatably supported by 21. The lower end of the light-blocking release lever 120 has a connecting dowel 110b of the connecting lever 110.
And a release portion 123 that engages with the light-blocking lever 220 of the shutter 200 at the upper end. Further, the light-blocking release lever 120 is urged by the tension spring 140 to rotate in the counterclockwise direction by the tension spring 140, and thus the connecting lever 110 constantly applies a rotational force in the clockwise direction. 130 is a body release release lever, which is a shutter 20 described later.
The body release lever 210 provided on the front plate 10 is driven, and is rotatably supported by the shaft 131 on the front plate 10. Body release release lever 130
The upper end of the connecting lever 110 is
And a drive unit 133 for driving the body release lever 210 at the left end.

FIGS. 7 and 8 are views of the shutter 200 as viewed from the front of the camera. In the set state before release, the front blade group 202 and the rear blade group 201 perform double shading. In the figure, the rear blade group 201 is driven so that about half or more of the aperture 203 overlaps with the front blade group 202,
The shutter 200 is double-shielded. Reference numeral 210 denotes a body release lever 1 described above.
30 rotates clockwise. Reference numeral 220 denotes a light-blocking lever, which is driven counterclockwise by the light-blocking release lever 120 to drive the rear blade group 201,
Perform heavy shading. FIGS. 9, 10 and 11 show a part of the drive system of the shutter 200 and show the role of the body release lever 210. FIG. In the figure, a body release lever 210 is rotatably held by a shaft portion 210b, and a tension spring 21 is rotated in a counterclockwise direction.
0a. The body release lever 210 has an arm 210c that is rotated clockwise by the body release release lever 130, and a tightening portion 210d that is a rotation stopper of the holding lever 211. A holding lever 211 is rotatably held by a shaft portion 211b and is urged by a tension spring 211a to rotate in a counterclockwise direction. Further, the holding lever 211 includes a stopper portion 211c abutting on a tension portion 210d of the body release release lever 210,
A holding member 21 for pressing and holding the armatures 213 and 215 of the electromagnets 214 and 216 to the electromagnets 214 and 216
2 The holding member 212 is swingably attached to a rotating end 211d of the holding lever 211 via a shaft 212a. Reference numeral 213 denotes a front blade armature for starting the driving of the front blade group 202. The front blade armature is rotatably supported by a shaft portion 213b. Turn power is applied. Reference numeral 215 denotes a rear blade armature for starting driving of the rear blade group 201.
15b, the attracting portion 215c is attracted to the electromagnet 216, and a counterclockwise rotating force is applied by the separating spring 215a.

FIGS. 12 and 13 show a double light shielding mechanism provided on the shutter 200. FIG. Reference numeral 220 denotes a light-blocking lever, which is rotatably supported by the shaft portion 221 and is urged to rotate clockwise by a return spring 220a. The light blocking lever 220 is moved by engaging with the release portion 123 of the light blocking release lever 120. It has an interface part 223 and a drive part 222 that engages with and drives the operating shaft 232 of the rear blade operating lever 230. A rear blade operating lever 230 is rotatably supported by a shaft 231 and is urged by a return spring 230a to rotate counterclockwise. Also, the rear blade operating lever 23
0 is connected to the rear blade group 201 by the operating shaft 232,
The counterclockwise rotation releases the double light blocking by the rear blade group 201.

FIGS. 14 and 15 are sectional views of the inside of the mirror box of the front plate 10 and the shutter 200. FIG. Reference numeral 300 denotes a semi-transmissive mirror configured to guide a part of the light incident by the photographing lens to the finder optical system 304 and transmit the remaining light to the film surface, and a thin film 303 formed on the main mirror frame 302. Is subjected to semi-transmissive mirror processing. The semi-transmissive mirror 300 includes a fixed dowel 3 fixed to the front plate 10.
01a, 301b, and are fixed to the dowels 301a, 301a by a pressing spring 313 mounted on the pressing frame 310 from above.
It is fixed by pressing against 301b. A holding frame 310 for fixing the transflective mirror 300 is fixed to the front plate 10 by a hinge portion 311 at an upper end and a fixing screw 312 at a lower end.

A sub mirror arm 320 is rotatably supported by an arm hinge shaft 322 fixed to the front plate 10. At the tip of the sub-mirror arm 320, a sub-mirror 305 for guiding a part of the light beam transmitted through the semi-transmissive mirror 300 to a photometric / ranging device (not shown) disposed below the front plate 10 is fixed. Sub mirror receiving plate 330
Has a sub-mirror hinge 323 for rotatably supporting the. A drive pin 321 for driving the sub-mirror arm clockwise by the mirror drive lever 70 is fixed to the center of the sub-mirror arm 320. An arm spring 324 biases the sub-mirror arm 320 in the counterclockwise direction to maintain the up state. One end is connected to the sub-mirror arm 320 and the other end is connected to the front plate 10.
This is a torsion spring fixed to the side of the mirror box. The sub-mirror receiving pin 330 fixed to the sub-mirror 305 is pressed against the sub-mirror driving pin 331 fixed to the sub-mirror receiving plate 330 by an up-biasing spring 340 fixed to the front plate 10, thereby causing the sub-mirror hinge. It is urged clockwise around 323. The sub-mirror receiving plate 330 is held in contact with a stopper dowel 360 having an eccentric shaft fixed to the mirror box side wall of the front plate 10. In the above configuration, when the release operation is started, the motor 20 is energized, and the driving force of the motor 20 is transmitted to the cam gear 60 via the reduction system 30, the transmission shaft 40, and the worm gear 50, and the cam gear 60 is rotated counterclockwise. Start rotating in the direction (Figs. 1 and 2).
The rotation of the cam gear 60 causes the mirror drive lever 70 to rotate clockwise, and the drive pin 32 of the sub-mirror arm 320 to rotate.
1 is depressed, and the sub-mirror arm 320 and the sub-mirror receiving plate 330 start to go down. On the other hand, the IF drive shaft 74 of the mirror drive lever 70 starts rotating the IF drive lever 80 counterclockwise. As shown in FIG. 2, when the roller portion 72 of the mirror drive lever 70 comes to the cam top of the drive cam 61, the cam top position is detected by a phase detection unit (not shown), and the motor 20 is turned off. The drive cam stops, and as shown in FIG. 15, the sub-mirror arm 320 and the sub-mirror receiving plate 330 are retracted below the mirror box to complete the down operation. At this time, the sub-mirror receiving plate 330 urges the sub-mirror driving pin 331 in the counterclockwise direction by the down-biasing spring 350, which is a leaf spring fixed to the front plate 10, and maintains the down state.

The mirror driving lever 70 is driven simultaneously with the IF
To rotate the drive lever 80 in the counterclockwise direction, the IF lever 90 is rotated in the clockwise direction as shown in FIG.

In FIG. 6, the shutter release lever 100
Is rotated counterclockwise against the force of the tension spring 140 by the movement of the IF lever 90, so that the connection lever 110 connected to the shutter release lever 100 is also operated by the cam portion 103 of the tension spring. It rotates clockwise against the force of 140. That is, the tension spring 1
At 40, the spring force is charged by the shutter release lever 100 and the connection lever 110 by the down drive of the sub mirror.

When the connection lever 110 is driven, the light-blocking release lever 120 connected to the connection lever 110 is actuated.
Then, the body release release levers 130 are each rotated counterclockwise. As shown in FIGS. 7 and 10, the body release release lever 130 rotated counterclockwise rotates the body release lever 210 of the shutter 200 clockwise against the spring force of the tension spring 210a.
At this time, the contact between the stopper portion 211c of the holding lever 211 and the tensioning portion 210d is released, and the holding lever 211 rotates counterclockwise by the spring force of the tension spring 211a, and the leading blade armature 213 and the trailing blade armature 215 Release the lock of.

The electromagnets 214 and 215 are of a type that generates a magnetic force when energized. In the operation sequence of the camera, energization is performed before the body release lever 210 operates. The armatures 213 and 215 continue to be attracted and held by the electromagnets 214 and 215 even when the armatures 210 and 210 are released and the holding of the armatures 213 and 215 by the holding lever 211 is canceled. ) (FIG. 11).

Next, the release of double light blocking of the shutter 200 will be described. As shown in FIG.
Is urged clockwise by the return spring 220a, but is prevented from turning clockwise by the light-blocking release lever 120. Further, the rear blade operating lever 230 is also opposed to the return spring 230a while the light shielding lever 2 is in the double light shielding position.
The shutter 200 performs double light shielding as shown in FIG. In this state, by driving the sub-mirror described above, the light-blocking release lever 120 retracts downward as shown in FIG. Shade lever 2
20 is rotated clockwise by the return spring 220a to release the holding of the rear blade operating lever 230. The rear blade operating lever 230 released from holding in the double light blocking state is driven together with the rear blade group 201 in the counterclockwise rotation direction by the return spring 230a, set before the rear blade travels, and the double light blocking is released.

As described above, the sub-mirror is retracted below the mirror box by driving the motor 20 as shown in FIG.
0 and the light-shielding lever 220 are driven to release the double light-shielding and to prepare for traveling of the shutter front and rear blade groups.
Exposure is performed by the operation of 4,216.

When the shutter 200 is actuated and the exposure is completed, the motor 20 rotates again to rotate the cam gear 60 in the same direction as when the sub-mirror is down, so that the mirror drive lever 70 is displaced from the top of the cam 61 and the sub-mirror arm 320 It rotates counterclockwise with the up operation and returns to the initial position. Similarly, the IF drive lever 80 and the IF lever 90 also move in the opposite direction to the last time and return to the initial position. The movement of the IF lever 90 causes the shutter release lever 100 and the connection lever 110 to rotate in a direction in which they are attracted to each other by the tension spring force,
0 and the body release release lever 130 are also driven, and the body release lever 210 and the light blocking lever 210 of the shutter 200 also return to their initial positions. Shutter 2
00 is set to a state before the shutter operation by a charging mechanism (not shown). At this time, a charging mechanism (not shown) rotates the holding lever 211 in the clockwise direction against the tension spring 211a to attract and hold the armatures 213 and 215 to the electromagnets 214 and 216. Further, the rear blade operating lever 230 is returned by the return spring 230a, but stops in the double light shielding state because the light shielding lever 220 is set during driving. The driving of a film feeding mechanism (not shown) is started almost simultaneously with the driving of the shutter charging mechanism, and the film is wound up. As described above, by driving as described above, the double light blocking is released by the sub-mirror down and the shutter is ready for running, and the double light blocking is performed again by the sub-mirror up, and the shutter charge and film winding are completed.
The camera is set to the shooting ready state. When the camera shooting mode is set to the continuous shooting mode, after the shutter 200 is operated and the exposure is completed, the power supply to the motor 20 is not performed, and only the shutter charging mechanism and the film feeding mechanism (not shown) are driven. The charging mechanism includes a holding lever 211
By driving the armatures 213 and 215 to the electromagnets 214 and 216,
4 and 216, the armatures 213 and 215 are sucked and held, and the photographing preparation is completed. At this time, since the body release lever 210 is held at the release position, the holding lever 211 is not locked at the position where the armatures 213 and 215 are held even after the shutter charge is completed, and moves to the release position. And rotate. Thereafter, when the film winding is completed, the release sequence is started again, and the shooting is sequentially performed.

In this embodiment, the shutter 20
0, the double shading is performed as shown in FIG.
Of the sub mirror arm 320 with respect to the aperture 401
And the sub-mirror receiving plate 330 covers the lower part of the aperture 401 about two-thirds, so that the double light shielding by the rear blade group 201 and the front blade group 202 of the shutter 200 is configured to cover the upper half of the aperture 401. doing.

[0033]

According to the present invention as described above,
Double light blocking is released in conjunction with the retraction operation of the second mirror
To maintain the second mirror in the retracted state.
The state of release of double light shielding is also maintained by
Useless for shooting that does not require double shading, such as continuous shooting
Effect that can eliminate unnecessary operations and improve durability etc.
There is. Furthermore, in the case of continuous shooting, the rear wing
Since there is no need for a secretary waiting for the root group to stabilize,
There is a great effect that the shooting frame speed can be increased.
You.

[Brief description of the drawings]

FIG. 1 is a side view of a sub mirror driving mechanism.

FIG. 2 is a side view of a sub mirror driving mechanism.

FIG. 3 is a plan view showing an IF lever.

FIG. 4 is a plan view showing an IF lever.

FIG. 5 is a side view of a shutter release mechanism.

FIG. 6 is a side view of a shutter release mechanism.

FIG. 7 is a front view of a shutter.

FIG. 8 is a front view of a shutter.

FIG. 9 is a plan view of a body release lever.

FIG. 10 is a plan view of a body release lever.

FIG. 11 is a plan view of a body release lever.

FIG. 12 is a plan view of a light blocking lever.

FIG. 13 is a plan view of a light blocking lever.

FIG. 14 is a sectional view showing an operation state of a sub mirror.

FIG. 15 is a sectional view showing an operation state of a sub mirror.

FIG. 16 is a partial perspective view of the back side of the camera.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Front plate 20 ... Motor 60 ... Cam gear 70 ... Mirror drive lever 80 ... IF drive lever 90 ... IF lever 100 ... Shutter release lever 110 ... Connection lever 120 ... Light blocking release lever 130 ... Body release release lever 200 ... Shutter 210 ... Body Release lever 220: Light blocking lever 400: Camera body

Claims (1)

(57) [Claims] 1. An image pickup optical path, which is disposed in a finder optical path.
A first mirror for guiding a light beam; and a photometric or focus detection device disposed in the photographing optical path.
Guides the light beam to the source and retracts outside the optical path during exposure.
A second mirror, a front blade group and a rear blade group, and a double shield by the rear blade group.
A shutter capable of holding a light state and the second mirror
The rear wing group is linked to the retracting operation outside the shooting optical path.
And a double light blocking release mechanism for releasing the double light blocking state.
A camera characterized by having .