JP2604814Y2 - Time adjustment mechanism for camera shutter - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time adjustment mechanism for a camera shutter.

[0002]

2. Description of the Related Art Since a camera shutter controls exposure in a very short time, it is difficult to obtain the timing of opening and closing the shutter blades as designed due to the influence of component accuracy and the like. Are adjusted by various methods in the manufacturing stage. The conventional time adjustment method for the electronic shutter includes a method of adjusting the degree of engagement between mechanical parts in an engagement relationship, a method of adjusting the timing of an electromagnet suction release signal by an electronic circuit, and a method of releasing the electromagnet suction. A device that adjusts the amount of spring force of an operating member that operates (Japanese Utility Model Publication No. Hei 3-2899) and a device that adjusts the position of an electromagnet are known. The present invention belongs to the method of adjusting the position of the electromagnet among these adjustment methods, and such a method is known from Japanese Patent Publication No. 4-3532.

[0003]

However, the structure described in Japanese Patent Publication No. 4-3532 has a drawback that the structure of the electromagnet assembly is extremely complicated and the cost is high. However, there is a drawback that even if it can be accurately adjusted at the time of manufacture, the ink is likely to be out of order during a long use due to a shock at the time of a shutter operation or the like.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to provide a correct attraction relationship between an actuating member attracted and held by an electromagnet against a spring and the electromagnet. It is an object of the present invention to provide a camera shutter time adjustment mechanism having a simple structure, which can surely adjust the position of an electromagnet at the time of manufacture without damaging it.

[0005]

In order to achieve the above object, the time adjusting mechanism of the present invention is arranged such that the operating member attracted and held by the electromagnet is operated by a signal from an exposure time control electronic circuit. When the holding force is released, in a camera shutter in which the shutter blade is driven by rotating away from the electromagnet by a spring, the electromagnet can be adjusted concentrically with the rotation axis of the operating member and rotationally adjusted. It is fixed to the provided base member.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a focal plane shutter will be described with reference to FIG. Reference numeral 1 denotes a shutter substrate, which has an exposure opening 1a, arc-shaped holes 1b, 1c, and has shafts 1d, 1e implanted therein. Reference numeral 2 denotes a leading blade operating lever, which is rotatably mounted on the shaft 1d and has an arc-shaped hole 1b.
And a pin 2a for operating a leading blade (not shown), as is well known, and a shaft 2b and pins 2c and 2d. Reference numeral 3 denotes a spring for giving the leading blade operating lever 2 a left-turning property. Reference numeral 4 denotes a first base member, which fixes the first electromagnet 5 and is rotatably attached to the shaft 1d.
The first electromagnet 5 includes an iron core 5a and a coil 5b. Reference numeral 6 denotes a spring for imparting left turning property to the first base member 4. Reference numeral 7 denotes an eccentric cam, which is rotatably attached to the shutter substrate 1 to adjust the angular position of the first base member 4 together with the spring 6. Reference numeral 8 denotes an iron piece member that is attracted to the iron core 5a, is rotatably mounted on the shaft 2b of the leading blade operating lever 2, and its rotation is restricted by pins 2c and 2d. Reference numeral 9 denotes a rear blade operating lever, which has a shaft 9b, pins 9c and 9d in addition to a pin 9a for operating a rear blade (not shown) on the rear surface of the shutter substrate 1 through the arc-shaped hole 1c. It is rotatably mounted on the shaft 1e, and is provided with a left turning property by a spring 10. Reference numeral 11 denotes a second base member, which fixes the second electromagnet 12 and is rotatably attached to the shaft 1e. The second electromagnet 12 includes an iron core 12a and a coil 12b. Reference numeral 14 denotes an eccentric cam, which is rotatably attached to the shutter substrate 1 in order to adjust the angular position of the second base member 11 in cooperation with the spring 13. An iron piece 15 is attracted to the iron core 12a, is rotatably mounted on the shaft 9b, and its rotation is restricted by pins 9c and 9d.

Next, the operation of the focal plane shutter having the above configuration will be described. In the state shown in FIG. 1, the release button of the camera is pressed during photographing, the power switch is turned on, the coils 5b and 12b are energized, and the iron cores 5a and 12
"a" shows a state in which the iron piece members 8, 15 are attracted. Next, when the current supply to the coil 5b is cut off by the exposure time control circuit, the leading blade operating lever 2 is rapidly turned left by the spring 3. Therefore, the front blade is driven by the pin 2a, moves upward from the state where the exposure opening 1a is covered, and opens the exposure opening 1a. When a predetermined time has elapsed after the energization of the coil 5b has been interrupted and the energization of the coil 12b has been interrupted by the exposure time control circuit, the rear blade operating lever 9 is rapidly turned left by the spring 10. Accordingly, the rear wing is driven by the pin 9a and moves upward from the lower portion of the exposure opening 1a, covers the exposure opening 1a, and the photographing ends. When charging the shutter, a charging member (not shown) turns the leading blade operating lever 2 and the trailing blade operating lever 9 clockwise to the position shown in FIG.
This state is maintained until power is supplied to 2b.

In such a shutter, when adjusting the time at the time of manufacture, the eccentric cams 7 and 14 are rotated to move the first base member 4 and the second base member 11 to the left or right with the shafts 1d and 1e, respectively. Adjust the angle by rotating the crab. As a result, the start interval between the leading blade operating lever 2 and the trailing blade operating lever 9 changes. Since the first base member 4 and the second base member 11 are arranged on the same axis as the front blade operating lever 2 and the rear blade operating lever 9, respectively, the iron piece members 8, 15 and the iron core 5 are provided.
a, 12a is always kept constant and does not change by the adjustment operation.

In the above embodiment, the base members 4, 1
The angle adjustment 1 is performed using the eccentric cams 7 and 14 and the springs 6 and 13. However, the base members 4 and 11 are provided with long holes, and the eccentric cams and the triangular cams are fitted into the long holes. Alternatively, the base members 4 and 11 may be screwed concentrically with the shafts 1d and 1e, and the screws may be temporarily loosened. Further, the adjusting mechanism of the present invention may be such that only one of the first electromagnet 5 and the second electromagnet 12 can be adjusted in the above embodiment, and it is needless to say that the adjusting mechanism can be applied to a lens shutter. In the embodiment, the operation levers 2 and 9 have been described as driving the shutter blades directly. However, the operation levers 2 and 9 may be used to release the locking member of the driving member.

[0010]

As described above, according to the present invention, the operating member attracted and held by the electromagnet against the spring and the base member to which the electromagnet is fixed are arranged concentrically, and the base member is mounted. Since the time adjustment of the shutter is performed by adjusting the angle, there is an effect that the structure is simple and the state of adsorption of the operating member by the electromagnet can always be adjusted in a fixed relation.

[Brief description of the drawings]

FIG. 1 is a front view of a focal plane shutter embodying the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shutter board 1a Exposure opening 1b, 1c Arc-shaped hole 1d, 1e, 2b, 9b Shaft 2 Front blade operating lever 2a, 2c, 2d, 9a, 9c, 9d Pin 3, 6, 10, 13 Spring 4 First base member 5 First electromagnet 5a, 12a Iron core 5b, 12b Coil 7, 14 Eccentric cam 8, 15 Iron piece member 9 Rear blade operating lever 11 Second base member 12 Second electromagnet

Claims (3)

(57) [Scope of request for utility model registration] When an operating member attracted and held by an electromagnet is released from its holding force by a signal from an electronic circuit for controlling an exposure time, the shutter is rotated away from the electromagnet by a spring to drive a shutter blade. 2. The time adjustment mechanism according to claim 1, wherein the electromagnet is fixed to a base member provided concentrically with a rotation axis of the operating member and capable of adjusting the rotation. And a locking member for locking the driving member, wherein the operating member releases the locking of the locking member by the rotation of the spring. 2. The time adjustment mechanism of a camera shutter according to claim 1, wherein 3. The time adjustment mechanism of a camera shutter according to claim 1, further comprising an adjustment unit that adjusts and positions a rotation angle position of the base member.