JPS6326812Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement of a camera having an electromagnetic drive device.

In the case of a camera with a conventional electromagnetic drive device, if the electromagnetic drive device is a shutter drive, the permanent magnet holding frame and the lens frame of the photographic lens are constructed as separate parts, regardless of whether the electromagnetic drive device is a shutter drive or a taking lens drive. was. The reason for this was that it was thought that it would be more advantageous to unitize each function in terms of workability and yield of each mechanism, but in reality, in electromagnetic drive devices, the number of moving parts such as moving coil members is extremely small. The present situation is such that there is no need to configure each mechanism with separate parts for each function, especially since there is no need for adjustment work during assembly. On the contrary, as cameras themselves have become smaller and more sophisticated in recent years, dividing the mechanism by function has the disadvantage of worsening mounting accuracy and making it impossible to make effective use of the narrow internal space. . For example, when designing an electromagnetic drive shutter device based on the optical axis of the photographic lens, if the lens frame of the photographic lens and the electromagnetic drive shutter device are separated by function, eccentricity and positioning due to mounting may occur. In addition, the lens frame cannot be used as it is as a bearing for the movable coil member of the electromagnetic shutter device, resulting in problems such as the need for extra space.

This invention attempts to solve the various problems mentioned above, and has a simple structure in which the holding frame of the fixed permanent magnet used in the electromagnetic drive device and the lens frame of the photographic lens are integrally molded from non-magnetic material. It is an object of the present invention to provide a camera having a high-precision electromagnetic drive device that effectively utilizes the space inside the camera and eliminates eccentricity between the optical axis of a photographing lens and the mounting position of a fixed permanent magnet.

Next, this invention will be explained based on an embodiment shown in the accompanying drawings.

1 is a molded product in which a central cylindrical portion 2 and a flange portion 3 are integrally molded from a non-magnetic material such as synthetic resin as shown in the second figure. The flange portion 3 constitutes a permanent magnet holding frame in which fixed permanent magnets 6 are embedded at a plurality of equidistant positions along the circumference. The front groups 4 and 5 of the photographing lens are fixed by a front frame 7 screwed onto the front outer periphery of the central cylindrical portion 2 serving as the lens frame. Reference numeral 8 denotes a first yoke fitted to the front outer periphery of the central cylindrical portion 2, and the first yoke 8 is attracted and fixed to the front surface of the flange portion 3 by the attraction force of the fixed permanent magnet 6. . 9 is the central cylindrical portion 2
A second yoke fitted to the rear outer periphery of the second yoke 9
is locked to an annular projection 3a provided on the outer circumference of the rear surface of the flange portion 3 by the attraction force of the fixed permanent magnet 6,
A constant gap G is maintained between the fixed permanent magnet 6 and the fixed permanent magnet 6. 10 is a fixed permanent magnet 6 and a second yoke 9
This is a movable coil member interposed in the gap G between the molded product 1 and the movable coil member, and is rotatably provided around the outer periphery of the central cylindrical portion 2 of the molded product 1. When a coil (not shown) is energized, the movable coil member 10 rotates to the right or left depending on the direction of the current. Reference numeral 11 denotes an aperture shutter blade, and the aperture shutter blade 11 has a shaft 13 between the second yoke 9 and a holding plate 12 fixed thereto with a screw (not shown) or the like at a constant interval. The movable coil member 10 is pivotally supported through the movable coil member 10, and is engaged with a pin 14 implanted in the movable coil member 10, so that the movable coil member 10 opens and closes in conjunction with the rotation of the movable coil member 10.

As described above, in this invention, since the holding frame of the fixed permanent magnet 6 and the lens frame of the photographing lens are integrally molded with non-magnetic material, when applied to the electromagnetic drive shutter device as described above, the light of the photographing lens Since the axis and the center of the shutter match with high precision without any adjustment, it is expected to improve workability during assembly, and the outer periphery of the lens frame can be used as is as a bearing for the moving coil member, reducing the number of parts. In addition, it can be installed without any problem even in cases where the internal space is narrow, such as in a miniaturized camera, and it has various excellent effects, such as greatly reducing the total cost of manufacturing the camera.

[Brief explanation of drawings]

The figures show an embodiment of this invention, with FIG. 1 being a side sectional view of the main part, and FIG. 2 being a partially cutaway perspective view of an integrally molded product. 1... Molded product, 2... Central cylindrical part (lens frame), 3
...Flange part (permanent magnet holding frame), 6...Fixed permanent magnet.

Claims (1)

[Scope of utility model registration request] A molded product that is integrally molded from a non-magnetic material and has a flange portion having a plurality of holes in the circumferential direction for installing permanent magnets, and a lens frame portion for holding a lens that protrudes from the flange portion. established,
A permanent magnet is disposed in a hole in the flange portion of the molded product, and a first yoke and a second yoke are coupled in front and behind the flange portion when viewed in the optical axis direction by the magnetic force of the permanent magnet, and A gap corresponding to the annular projection provided on the outer periphery of the flange portion is provided between the second yoke and the flange portion, a moving coil member is provided within the gap, and a driven member is provided on the outside of the second yoke. A camera with an electromagnetic drive device.