JPH0356604B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a lens moving device, and particularly to a lens moving device used for extending a lens for focusing.

(Prior Art) At present, costs have been reduced, especially in cameras using single-focus lenses, metal parts have been replaced with resin molded products, engravings have changed to engravings, and even alumite printing has undergone major changes.

Currently, the areas where cost reduction has not progressed are focusing means and exposure means.

Of these, most of the focusing means of photographic lenses are based on helicoid screws. This helicoid screw is configured as a double helicoid because linear movement of the lens group is required due to the aperture control mechanism.

For this reason, four large parts are essential: an operating ring, a fixed cylinder, a female helicoid, and a male helicoid, and helicoid screws must be formed in four locations. Even if an attempt is made to make this into a resin, it is difficult to manufacture a mold, the mold becomes expensive, and there are also problems in the environmental resistance technology for resin parts.

Additionally, cam grooves are widely used as lens moving devices for zoom lenses for zooming, but it is also extremely difficult to make them into resin.

As another lens moving means, a rack and pinion requires a long focusing operation time, cannot be made compact in structure, and is expensive.

The end cam can be easily made of resin, but it requires a biasing means to keep the follower in constant contact with the cam surface, and if the amount of movement is large, the change in force required for operation becomes large, making it unusable.

A moving device using a sliding cylinder has a simple structure and short focusing operation time, but it is inevitably inaccurate due to minute movements.

(Purpose of the Invention) The present invention proposes a new structure for a lens moving device based on resin, and aims to obtain a low-cost lens moving device that does not have the drawbacks of conventional moving devices. It is.

(Structure of the Invention) As shown in the drawings, the lens moving device of the present invention includes a fixed barrel 1 fixed to a camera or the like, an operating ring 2,
It consists of a sliding tube 4 that also serves as a lens holding frame. A shaft 3c rotatably passes through the fixed cylinder 1, and a gear 3 that meshes with the rack portion 2a of the operating ring 2 is provided on one side of the shaft 3c.
However, on the other side, a rotary plate 3a having pins 3b inserted into circumferential grooves 4a of the lens holding frame 4 is fixed. Reference numeral 5 denotes a linear guide plate provided so that the lens holding plate 4 does not rotate but moves back and forth, and is guided in a straight line by a linear groove 1a provided in the fixed barrel 1.

By rotating the operating ring 2, the rack portion 2a of the operating ring rotates the gear 3, and the rotary plate 3a, which is integrally fixed thereto, is rotated. The pin 3b set on the rotary plate 3a is inserted into the circumferential groove 4 of the lens holding frame 4.
a, the rotation of the rotating plate 3a results in sliding of the lens holding frame 4 back and forth.

Among the above configurations, the rotation angle of the gear can be freely selected, and the gear 3 may be a semicircular plate accordingly.If the rotation angle is 180° and the amount of close distance movement is obtained, the rotation of the operating ring in the same direction From ∞ to close range further ∞
This enables endless focusing operations.

Furthermore, when the rotation angle of the gear is small, a pin may be directly implanted in the gear and engaged with the lens holding frame through a groove in the fixed barrel.

(Effects of the Invention) The present invention has the above configuration, and (1) a simple and compact lens moving device can be obtained.

(2) The shape of the component parts can be easily molded with resin, making it possible to achieve low costs.

(3) Inevitably, the amount of lens movement and the amount of operation of the operating ring are not constant, so it is possible to make a fine distance adjustment on the long distance side and coarse distance adjustment on the short distance side, or vice versa, depending on the lens characteristics.

(4) A click is provided at the ∞ position so that the user can focus by rotating the operating groove in either direction.

(5) Endless focusing becomes possible as described above.

(6) If the distance scale ring of the operation ring is attached separately and only the rotary plate is prepared individually, large parts can be shared for photographic lenses with focal lengths within a certain range.
Furthermore, cost reduction becomes possible.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main parts of the lens moving device of the present invention, and FIG. 2 is a perspective view of the same. 1: Fixed barrel, 2: Operating ring, 3: Gear, 3a: Rotating plate, 3b: Pin, 4: Lens holding frame, 4a:
Groove, 5: Straight guide plate.

Claims (1)

[Claims] 1 Consisting of a fixed barrel, an operating ring rotatably held by the fixed barrel, and a lens holding frame slidably held by the fixed barrel, the lens holding frame is pivotally supported by the fixed barrel and is easily attached to the operating ring. A lens moving device comprising a gear that meshes with the gear and a member that rotates integrally with the gear, and a lens holding frame is moved by the rotating member.