JPS62220939A - Lens driving and shutter opening and closing mechanism for camera - Google Patents

Abstract

PURPOSE:To drive a lens and open and close a shutter by one pulse motor and to simplify the constitution of a mechanism by providing a driving member, a distance setting member, a stop claw, and a shutter opening and closing member. CONSTITUTION:The driving member 13, distance setting part 14, stop claw 16, and shutter opening and closing member 21 are provided, and the driving member 13 is driven by the pulse motor 11 in a direction of forward rotation from its reference position and then returned to its original position and further driven in the opposite direction from the reference position and then returned to the reference position; when the driving member 13 rotates forward from the reference position, a lens is driven to perform focusing and when the driving member 13 revreses from the reference position and returns to the reference position, the shutter is opened and closed. Consequently, the one pulse motor can drive the lens and open and close the shutter and a magnet for stopping the lens at its focusing position need not be provided, so the mechanism and circuit constitution are simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a camera lens drive and shutter opening/closing mechanism in which a single pulse motor drives a lens and opens/closes a shutter.

(Prior art) Conventional cameras incorporate a lens drive mechanism for moving the lens to the in-focus position and a shutter opening/closing mechanism that closes the shutter after a predetermined period of time according to the photometric value as separate mechanisms. These could be operated individually. In place of such conventional cameras, attempts have been made to drive the lens and open and close the shutter using a common motor.

However, the common motor-based lens drive and shutter opening/closing mechanisms that have been considered so far use a magnet to stop the lens at the in-focus position, even though the lens is driven by a motor. A magnet and its driving circuit were required.

(Objective) An object of the present invention is to drive a camera lens by making it possible to drive the lens and open/close the shutter with a single pulse motor, thereby eliminating the need for a magnet and its drive circuit, thereby simplifying the configuration. and to provide a shutter opening/closing mechanism.

(Structure) In the present invention, the pulse motor is driven from a reference position in the forward direction by an amount corresponding to the measured distance value and then returned, and then driven from the reference position in the reverse direction and then returned to the reference position. When the driving member is rotated in the normal direction from the reference position, it is rotated against the biasing force according to the amount of normal rotation, and the distance that moves the lens in the optical axis direction by an amount corresponding to the measured distance value. The setting member and the distance setting member are biased in a direction to engage with the distance setting member so as to prevent rotation by force, and the driving member is driven only when the driving member is returned from the reverse position to the reference position. a stop pawl that is pushed around by the member against the biasing force to release the engagement with the distance setting member;
The shutter opening/closing member is actuated to open the shutter when the drive member is driven from the reference position in the reverse direction, and is actuated to close the shutter when the drive member is returned from the reverse position to the reference position. It is characterized by

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a camera lens drive and shutter opening/closing mechanism according to the present invention will be described with reference to the drawings.

In FIG. 1, the rotational driving force of the pulse motor 11 is transmitted through a reduction gear train 12 to a partial gear 13 of a vane opening/closing ring 13.
1, and the ring 13 is rotationally driven in the forward rotation direction and the reverse rotation direction.

A bent portion 132 is formed at the outer peripheral edge of the blade opening/closing ring 13, and the tip surface of this bent portion 132 is an inclined surface 133. A cam 134 and a protrusion 135 are also formed on the outer peripheral edge of the blade opening/closing ring 13. A part of the position switch 25 extends into the passage of the protrusion 135, and when the blade opening/closing ring 13 is at the reference position as shown in the figure, the position switch 25 is pushed by the protrusion 135 and turned on. There is. A protrusion 143 of the distance cam 14 is located close to the side of the tip of the bent portion 132 . The distance cam 14 is formed into a substantially cylindrical shape, and on its outer periphery, a ratchet portion 144 is formed following the projection 143, and another projection 142 is formed. Protrusion 14
A spring 15 is applied to 2 to urge the distance cam 14 to rotate counterclockwise in the figure, and a stopper 27 restricts the rotation of the distance cam 14 due to the urging force.

Here, in the diagram of the blade opening/closing ring 13, if clockwise rotation is the normal rotation direction and counterclockwise rotation is the reverse direction, when the ring 13 rotates from the reference position in the normal direction, the tip of the bent portion 132 The protrusion 14 of the distance cam 14 on the path of the
3 to rotate the distance cam 14 clockwise against the biasing force of the spring 15. distance cam 1
Three cam surfaces 141 of the same shape are formed on the top surface of the cylindrical distance cam 14. The lower half of the lens frame 18 is loosely fitted into the cylindrical distance cam 14. Three pins 182 are in contact with the three cam surfaces 141, respectively.

The lens frame 18 holds the lens 17 integrally. Further, a pair of fork-shaped portions 181 are formed on the outer circumference of the lens frame 18 , and guide pins 20 are fitted into these fork-shaped portions 181 , so that the lens frame 18 is guided by the pins 20 and the light from the lens 17 is guided. It is movable in the axial direction, but cannot rotate around the optical axis.

There is a ring-shaped presser spring 19 above the lens frame 18, and three elastic arms 191 formed on the inner circumferential side of the spring 19 push the lens frame 18, thereby pushing the pin 182 of the lens frame 18 into the distance cam. It is pressed against the cam surface 141 of 14.

A stop pawl 16 is disposed on the side of the projection 143 and ratchet portion 144 of the distance cam 14 so as to be rotatable in a horizontal plane by a shaft 28. The stop pawl 16 is formed in the shape of a bell crank, and one end of the arm is a pawl part 161 facing the ratchet part 144, and the other end of the arm is a pawl part 161 as shown in FIG. As shown, a diagonally upward bent portion 162 is formed at a position facing the tip inclined surface 133 of the bent portion 132 of the blade opening/closing ring 13.

The stop pawl 16 is urged to rotate clockwise by a spring 29, and normally the pawl portion 161 is attached to the ratchet portion 1 of the distance cam 14.
44.

There is a shutter board 26 below the blade opening/closing ring 13, and the shutter board 26 has a pair of shutter blades 22.
is rotatably provided by a shaft 31 in a plane parallel to the surface of the substrate 26, and the sector lever 21 is rotatably provided by a shaft 30 in a plane parallel to the substrate 26. The sector lever 21 is urged to rotate clockwise by a spring 24, and when a pin 211 fixed to the arm end of the sector lever 21 comes into contact with the outer peripheral surface of the blade opening/closing ring 13, the above urging force is applied. The rotation of the sector lever 21 is restricted. The pin 211 of the lever 21 is connected to a pair of shutter blades 22
．． Long holes 2 are formed to intersect with each other.
It passes through 21.221. The pin 211 is pushed by the cam 134 of the blade opening/closing ring 13 and rotated counterclockwise against the urging force when the blade opening/closing ring 13 is reversed by a certain amount from the reference position. . This counterclockwise rotation of the sector lever 21 causes the pin 211 to rotate the pair of shutter blades 22 and 22 in opposite directions to open the optical path.
3 rotates toward the reference position, the sector lever 21 rotates clockwise, causing the shutter blades 22, 22 to return to rotation, thereby closing the optical path. A trigger switch 23 is located on the side of the pin 211 of the sector lever 21.
The trigger switch 23 is pressed by the pin 211 and turned on in the normal state when the shutter is closed, but when the shutter is opened, the trigger switch 23 is turned on by the pin 211.
The trigger switch 2 escapes from the trigger switch 23.
3 is turned off. The sector lever 21 serves as a shutter opening/closing member.

The blade opening/closing ring 13 serves as a driving member that drives the lens 17 in the optical axis direction and opens and closes the shutter, and is driven by the pulse motor 11 in the normal rotation direction from the reference position shown in the figure by an amount corresponding to the distance measurement value. Then, after being driven in the reverse direction by a certain amount from the reference position, it is returned to the reference position. position switch 2
5 is for detecting the reference position.

The distance cam 14 constitutes a distance setting member, and when the blade opening/closing ring 13 is rotated forward from the reference position, it is rotated against the biasing force according to the amount of forward rotation, and due to this rotation,
The lens 17 is moved in the optical axis direction by an amount corresponding to the measured distance value. The sector lever 21 serves as a shutter opening/closing member.

Next, the operation of the above embodiment will be explained.

Now, when a shutter button (not shown) is pressed and a start switch is turned on, an automatic focus detection device (not shown) measures a distance, and the number of steps to drive the pulse motor 11 is stored in accordance with the measured distance value. The pulse motor 11 is driven in accordance with this number of steps, and the blade opening/closing ring 13 is rotated from the reference position in the normal rotation direction by an amount corresponding to the measured distance value, that is, clockwise in FIG. 1. ring 1
3, the bent portion 132 pushes the protrusion 143 of the distance cam 14, causing the distance cam 14 to rotate clockwise against the biasing force. The amount of rotation of the distance cam 14 is determined by the amount of rotation of the ring 13. The cam surface 14 that the pin 182 of the lens frame 18 comes into contact with is determined by the amount of rotation of the distance cam 14.
1 is determined, and the lens 17 is moved in the optical axis direction by an amount corresponding to the measured distance value to achieve focusing.

When the blade opening/closing ring 13 is rotated in the forward direction by an amount corresponding to the measured distance value, the pulse motor 11 is subsequently reversed and the blade opening/closing ring 13 is returned to the reference position. At this time, the tip of the bent portion 132 of the ring 13 comes into contact with one arm end of the stop claw 16, but the bent portion 132
has an inclined surface 133 at the tip thereof, and this inclined surface 133 forms the diagonally upward bending portion 162 of the stop claw 16.
Since it passes under the stop pawl 16 and passes through the position of the stop pawl 16 while elastically bending the stop pawl 16, the stop pawl 16 is not rotated. Further, the rotation of the distance cam 14 in the biasing direction by the spring 15 is caused by the stop pawl 1
This is prevented by the claw portion 161 of No. 6 engaging with the ratchet portion 144, and the lens 17 is held at the in-focus position.

The pulse motor 11 continues to drive the blade opening/closing ring 13 to rotate it by a certain amount in the reverse direction from the reference position. The reversal of the ring 13 causes its cam 134 to push the bin 211, causing the sector lever 21 to rotate counterclockwise. This rotation of the lever 21 causes the shutter blades 22, 22 to rotate and begin to open the shutter.

At the same time as the shutter begins to open, the trigger switch 23 is turned off and the seconds are counted. When the seconds determined by the photometric circuit (not shown) are reached, the pulse motor 11 is reversed again and the blade opening/closing ring 13 is moved toward the reference position. It is rotated forward towards the target. The forward rotation of the ring 13 causes the sector lever 21 to rotate in the urging direction, and the shutter blade 2
2. Rotate 22 back and close the shutter.

Even after the shutter is closed, the blade opening/closing ring 13 is rotated in the forward rotation direction and reaches the reference position. In the process of the ring 13 reaching the reference position, the tip of the bent portion 132 pushes the end of one arm of the stop pawl 16, causing the pawl 16 to rotate counterclockwise against the biasing force. The locking of the ratchet portion 144 by the claw portion 161 is released. As a result, the distance cam 14 rotates back in the urging force direction, and its cam surface 141 pushes up the lens frame 18 to reset the lens 17. When the blade opening/closing ring 13 returns to the reference position in this way, its protrusion 135 turns on the position switch 25, and then the step motor 11 is rotated by several pulses and then stopped, completing one sequence of operations.

Figures 3 and 4 show the above operations in a simplified manner. Figure 3 shows the relationship between lens operation and shutter operation with respect to the rotational direction of the step motor, and Figure 4 shows the operation of the entire camera. The outline is shown below.

As shown in Figure 3, when the step motor is driven in the forward direction from the reference position, the lens is driven in the optical axis direction by the number of steps corresponding to the distance measurement value, and the motor is returned to the reference position. The shutter is then opened by driving a certain amount in the reverse direction, the shutter is closed by driving the motor in the forward direction, and the motor is further rotated in the forward direction to reach the reference position. Lens position will be reset. The number of lens driving steps may be set arbitrarily.

As shown in Figure 4, the overall operation of the camera is as follows: When the release is released, distance measurement is first performed by the automatic focus detection device, then the lens is operated in the optical axis direction according to the distance measurement value, and then First, the shutter is opened and closed in seconds according to the photometric value, then the lens position is reset, and finally the film is wound to complete one sequence. The lens operation and shutter opening/closing portions in this one sequence are the operational portions that are relevant to the present invention.

The lens drive and shutter opening/closing mechanisms described above are controlled by an appropriate sequence control circuit.

FIG. 5 schematically shows an example of the control circuit. In FIG. 5, the sequence control CPU 32 includes a trigger switch 2.
3 and position switch 25 are connected, and a start switch 35 operates in conjunction with the release button.
is connected. Further, the CPU 32 controls the pulse motor 11 in the forward and reverse directions via the pulse motor driver 46 based on distance measurement information and exposure information from the automatic focus unit 33 and the automatic exposure unit 34. . Incidentally, since the sequence control circuit has no direct relation to the present invention, a detailed explanation thereof will be omitted.

Next, another embodiment of the camera lens drive and shutter opening/closing mechanism according to the present invention will be described with reference to FIGS. 6 and 7. Since most of the components of this embodiment are substantially the same as those of the embodiment shown in FIG. 1, the explanation will focus on the different components.

In FIGS. 6 and 7, a pinion 41 that is integral with the output shaft of the pulse motor 11 is meshed with a drive gear 42. As shown in FIGS. The drive gear 42 constitutes a drive member and replaces the blade opening/closing ring 13 in the above-described embodiment.

The drive gear 42 has a cam protrusion 424 and a push pin 4 on the top side.
21 and a push plate 422, and a bottle 425 on the lower surface side. The drive gear 42 is driven by the pulse motor 11 from the reference position shown in the figure in the forward direction (counterclockwise in the figure) by an amount corresponding to the measured distance value, and then returned, and then from the reference position in the reverse direction (in the figure clockwise) and then returned to the reference position. When the drive gear 42 is at the reference position, the cam protrusion 424 pushes the position switch 25 to turn it on. The tip end surface of the push plate 422 of the drive gear 42 is an inclined surface 423, and the one arm end 432 of the stop ring 43 is located immediately to the side thereof, and the drive gear 42 is driven in the reverse direction from the reference position. When the push plate 422 is pressed, the inclined surface 423 of the push plate 422 slips under the arm end 432 of the stop ring 43. Push pin 4 of drive gear 42
There is a protrusion 143 of the distance cam 14 near the side of 21,
When the driving gear 42 is driven in the forward rotation direction from the reference position, the projection 143 pushes the projection 143 to rotate the distance cam 14 clockwise in the figure.

The stop ring 43 is rotatable in a horizontal plane about a shaft 44, and is biased to rotate counterclockwise by a spring 45. Normally, the stop ring 43 rotates due to the biasing force, and its claw portion 431 engages the distance cam 14. It is adapted to engage with the ratchet portion 144.

The pin 425 of the drive gear 42 is located on the side of one arm of the sector lever 21 as a shutter opening/closing member.
When the sector lever 21 is driven in the reverse direction from the reference position, the pin 425 rotates the sector lever 21 counterclockwise against the biasing force, and the pin 211 of the lever 21 rotates the shutter blade 2
2.22 is rotated to open the shutter.

The rest of the structure is the same as that of the embodiment shown in FIG. 1, so the explanation will be omitted.

Now, when the start switch linked to the release button is turned on, distance measurement is performed, and pulse motor 1 is activated according to the distance measurement value.
1, the drive gear 42 is driven in the forward rotation direction (counterclockwise in the figure) from the reference position.

The forward rotation of the drive gear 42 causes the push pin 421 to move into the protrusion 1.
43 to rotate the distance cam 14 clockwise, and by moving the cam surface 141, a lens (not shown) is moved in the optical axis direction to perform focusing. This in-focus position is maintained by engagement of the claw portion 431 of the stop ring 43 with the ratchet portion 144.

After the drive gear 42 is returned to the reference position, it is subsequently driven in the reverse direction (clockwise in the figure), and the pin 425 rotates the sector lever 21 counterclockwise against the biasing force to open the shutter. When the driving gear 42 is rotated in the reverse direction, the tip of the pushing plate 422 hits the one arm end 432 of the stop ring 43, but the tip inclined surface 423 of the pushing plate 422 hits the one arm end of the stop ring 43. After getting under the part 432, it passes the position of the arm end part 432. At the same time as the shutter starts to open, the trigger switch 23 is turned off, and when a time period corresponding to the photometric value has elapsed from that point, the drive gear 42 is rotated forward and the shutter is closed.

When the drive gear 42 is further rotated forward and reaches the reference position, the tip of the push plate 422 of the drive gear 42 pushes the one arm end 432 of the stop ring 43, causing the stop ring 43 to resist the biasing force and rotate clockwise. The ratchet portion 144 is unlocked by the claw portion 431, the distance cam 14 is rotated back in the biasing direction, and the lens (not shown) is reset to its original position, completing one sequence.

According to the embodiments shown in FIGS. 6 and 7, the lens drive and shutter opening/closing operations can be performed directly by the final stage of the deceleration mechanism without intervening the shutter opening/closing ring in the embodiment shown in FIG. This has the advantage of simplifying the configuration.

(Effects) According to the present invention, the driving member is driven by the pulse motor in the normal direction from the reference position and then returned to the original position, and is also driven in the reverse direction from the reference position and then returned to the reference position. When the member rotates forward from the reference position, the lens is driven to perform focusing, and when the drive member rotates reversely from the reference position and returns to the reference position, the shutter is opened and closed.The lens is driven by a single pulse motor. Furthermore, since there is no need to provide a magnet or the like to stop the lens at the in-focus position, the lens driving and shutter opening/closing mechanisms of cameras with simple mechanisms and circuit configurations are possible. can be provided.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the camera lens and shutter drive mechanism according to the present invention, and FIG. 2 is a side view showing the stop pawl and blade opening/closing ring in the same embodiment.
FIG. 3 is a diagram showing the outline of the operation of the above embodiment, FIG. 4 is a flowchart showing the overall operation order of the camera having the mechanism according to the above embodiment, and FIG. 5 is a control circuit applicable to the present invention. FIG. 6 is a plan view showing another embodiment of the camera lens drive and shutter opening/closing mechanism according to the present invention, and FIG. 7 is an exploded perspective view of the same embodiment. 1 Toe pulse motor, 13--Blade opening/closing ring as a driving member, 14--Distance cam as a distance setting member, 16.43--Stop claw, 17--Lens, 21--Shutter opening/closing Sector lever as member, 42-drive gear as drive member. If) C5 mouth 4 shaku

Claims (1)

[Scope of Claims] A drive in which a pulse motor is driven from a reference position in the forward direction by an amount corresponding to the distance measurement value and then returned, and then driven from the reference position in the reverse direction and then returned to the reference position. When the member and the driving member are rotated in the normal direction from the reference position, the lens is rotated against the urging force according to the amount of normal rotation, and the lens is moved in the optical axis direction by an amount corresponding to the measured distance value. a member, the distance setting member being biased in a direction to engage the distance setting member so as to prevent the distance setting member from rotating due to the force, and the driving member being urged to engage the distance setting member only when the driving member is returned from the reversed position to the reference position. a stop pawl that is pushed around against the biasing force to release the engagement with the distance setting member; and when the drive member is driven in the reverse direction from the reference position, the shutter is operated in the direction to open the shutter, and the drive member is moved to the reverse position. A lens drive and shutter opening/closing mechanism for a camera, comprising a shutter opening/closing member that is operated in a direction to close the shutter when the shutter is returned to a reference position.