JPH075470Y2 - Program shutter adjustment mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an adjusting means for a sector drive unit in a motor-driven program shutter.

[Prior Art] Generally, a shutter proposed by the present applicant in Japanese Patent Application No. 58-164546, which determines the opening amount of a sector by the rotation amount of a motor, accurately determines the phase relationship between the motor and the sector. Need to match. However, as a means for transmitting the rotation of the motor to the sector, a gear mechanism is generally used, and in order to smoothly transmit the rotation, a backlash is provided in the meshing portion and a clearance is provided in the rotation supporting portion. In addition, each component always has a part manufacturing error, and also has an error in the step angle due to the coupling force of the stator of the motor and the magnetic poles of the rotor and the positional accuracy. Therefore backlash,
Clearance, component error, step angle error, etc. become a phase error between the motor and the sector, and it is difficult to obtain an accurate sector opening amount due to this phase error. Especially when the subject of the camera is bright, the sector opening amount is small. If that is very problematic.

As a motor-driven shutter with the above-mentioned drawbacks improved, as proposed by the present applicant in Japanese Patent Application No. 59-26807, an adjusting unit for changing the phase relationship between the motor and the sector driving member is used as a sector. It was arranged on the driving member, and the phase relation was changed by rotating the adjusting pin. FIG. 4 is an example of a shutter using a conventional adjusting unit, and shows a state before the operation of the camera. In FIG. 4, the rotation of the output shaft 1 of the motor rotates the driving member 10 via the gear train of the pinion 2, the idler 11, and the sector gear 10a, and the cam portion 10b provided at a part of the peripheral edge is
The sector opening / closing member 6 is actuated by engaging the eccentric pin 8 provided on the sector opening / closing member 6 so as to be rotatable with a predetermined torque and having a slit groove for adjusting the head,
Sectors 5a and 5b exposed.

In such a structure, the motor and the sector opening / closing member 6 are rotated by rotating the eccentric pin 8 with an adjusting tool such as a driver.
It is possible to change the phase relationship with. However, since the eccentric pin 8 operates integrally with the sector drive member 6, the eccentric pin 8 cannot be rotated by the adjusting tool during the shutter operation, and the adjusting tool must be attached / detached every shutter operation. There was a drawback.

[Purpose] The present invention aims to improve the above-mentioned drawbacks and provide an adjusting mechanism capable of adjusting the phase relationship between the motor and the sector opening / closing member even while the shutter is operating.

[Means for Solving the Problems] According to the present invention, a plurality of sectors forming a lens aperture, a motor that can be controlled to rotate forward and backward, a driving member driven by the motor, and the driving member. In a program shutter for controlling the opening / closing operation of the sector, which has a sector opening / closing member connected to drive the sector,
The object is achieved by providing the eccentricity adjusting means on the rotation support portion of the sector opening / closing member.

[Embodiment] The details of the present invention will be described below based on the illustrated embodiment.

1 and 2 show an embodiment of the present invention. A step motor M used in the present invention relates to a rotor composed of a permanent magnet which is rotatably supported and is magnetized in multiple poles in a radial direction, and the rotor. The step motor is a known step motor including at least two stators and a coil for exciting the stator. Reference numeral 1 is an output shaft of the step motor M, and a pinion 2 for transmitting rotation of the motor M is provided at a tip end portion thereof.
Is stuck. Reference numerals 3 and 4 are an upper base plate and a base plate, which are substantially circular and have an opening 0 for a lens opening formed in the center thereof, and a sector chamber is formed between them by overlapping them. Stores two sectors 5a and 5b. A ring-shaped drive member 10 is rotatably attached to the upper surface of the upper base plate 3 with the lens opening edge 3a as a guide, and a cam portion 10b provided on a part of the peripheral edge of the ring-shaped drive member 10 on the sector opening / closing member 6. The sector opening / closing member 6 is configured to swing by acting on the driving member pin 6a. On the other hand, the sector opening / closing member 6 is provided with a sector pin 6b at its tip, and the two sectors 5a, 5b axially supported by the pins 9a, 9b protruding from the upper base plate 3 are opened / closed by the common sector pin 6b. Driven. An eccentric pin 7 which is a rotation shaft of the sector opening / closing member 6 is fixed to the upper base plate 3 so as to be rotatable with a predetermined torque, and is press-fitted into the main plate.
7a and the supporting portions 7b of the sector opening / closing member 6, and a slit groove 7c for adjusting the upper ends of the 7b. Further, the sector opening / closing member 6 has an eccentricity between the support portion 7b and the press-fitting portion 7a, and the slit groove 7c is rotated by an adjusting tool such as a screwdriver.
Moves with the eccentricity. Therefore, the phase relationship between the drive member pin 6a and the drive member 10, that is, the phase relationship between the step motor and the sector opening / closing member 6, can be changed, and the overlapping amount and the opening diameter of the sector can be changed.

In addition, the sector driving member 6 is driven by a spring 12 by a driving member pin.
6a is always urged so as to follow the driving member 10, and 16 is a pressing plate that covers the upper surfaces of the driving member 10 and the idler 11.

The operation of the above configuration will be described below.

FIG. 1 shows a state before the operation of the camera. Two sectors 5a and 5b engaged with the sector pin 6b close the lens opening 0, and the step motor M is not energized. In this state, the release means, the photometric means, etc. of the camera (not shown) are activated, a signal is output from the drive circuit to the step motor M according to the brightness information of the subject, etc., and the output shaft 1 of the step motor M rotates in the clockwise direction. To do. This rotation is transmitted to the sector gear 10a via the pinion 2 and the idler 11, and the drive member 10 is normally rotated clockwise. Drive member
As the 10 rotates in the forward direction, the cam portion 10b becomes the driving member pin 6a.
The sector opening / closing member 6 is pushed up, and the sector 5 starts the opening motion to start the exposure.

After a predetermined exposure is obtained, the drive circuit causes the step motor to rotate in the reverse direction, the drive member 10 rotates counterclockwise in the counterclockwise direction, and the sector opening / closing member 6 that follows the cam portion 10b rotates clockwise to move the sector. 5, the opening 0 is closed and the exposure is completed. After the exposure, the step motor M continues to rotate in the reverse direction,
The state returns to the state shown and the rotation of the step motor ends.

In such shutter operation, the phase relationship between the drive member 10 and the sector opening / closing member 6 is changed by rotating the eccentric pin 7 by an adjusting tool such as a screwdriver in the assembly process, and the operation of the sector is shown in FIG. ) And (b) move. Therefore, the two sectors 5a before operation,
Since the overlapping amount of 5b and the opening diameter during opening operation change, not only the exposure adjustment but also the backlash of the meshing part described above,
It is possible to adjust the phase shift due to the clearance of the rotation support portion, component manufacturing error, and the like.

[Effect] As described above, according to the present invention, the eccentric pin 7 does not operate integrally with the sector opening / closing member 6, and the shutter is operated with the eccentric pin 7 associated with an adjusting tool such as a driver. Since the shutter can be operated, adjustment can be performed while continuously operating the shutter, the adjustment time can be reduced, and it is advantageous in automating the adjustment process. Further, since the sector opening / closing member 6 does not need to have an eccentric pin connected thereto, the drive member pin 6a and the sector pin 6b can be integrally formed by plastic molding.
The number of parts can be reduced, which contributes to a reduction in manufacturing cost.

Incidentally, although the present embodiment is based on the step motor,
If forward and reverse rotation can be controlled, a similar effect can be obtained with a DC motor, an ultrasonic motor, or the like.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a main sectional view of FIG. 1, FIG. 3 is an operation diagram of a sector, and FIG. 4 is an embodiment of a conventional example. M: Step motor, 6: Sector opening / closing member, 7, 8
...... Eccentric pin, 10 ...... Drive member.

Claims (1)

[Scope of utility model registration request] 1. A plurality of sectors forming a lens aperture, a motor capable of controlling forward and reverse rotations, a drive member driven by the motor, and a sector opening / closing member connected to the drive member to drive the sector. In the program shutter for controlling the opening / closing operation of the sector, eccentricity adjusting means for changing the phase relationship between the motor and the sector opening / closing member is provided in the rotation support portion of the sector opening / closing member. Program shutter adjustment mechanism.