JPS59127029A - Lens switching device of camera - Google Patents

Abstract

PURPOSE:To switch securely a focal length with high precision by one-touch switching operation by projecting a lens barrel when a changeover ring is switched, and extending an auxiliary focusing guide to between a focusing guide and a focusing member, and extending a conversion lens into an optical path. CONSTITUTION:A cam pin 6 implanted in the outer circumferential surface of the lens barrel 3 is fitted in a grooved cam 5 in the outer circumferential surface of the changeover ring 2 to project the lens barrel 3 at a telephoto position T and retract it at a wide-angle position W. The conversion lens 11 is rotated clockwise during wide-angle switching by a cam pin 15 coupling with a cam 16 formed on the internal surface of the rear surface of the changeover ring 2 to save to the outside of an optical path, and constitutes a telephoto lens together with a main lens during telephoto switching. A camera body 1 incorporates a switching member 22 which is coupled when a cam pin 22a abuts on a cam 21 formed in the internal surface of the rear part of the changeover ring 2 and is energized counterclockwise by a spring 24, and the auxiliary focusing guide 25 is extended to between the focusing guide 10 and a lens driving lever 17 during switching to the telephoto position T.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to improvements in camera lens switching devices.

[Prior art]

Regarding a camera that has a main lens and a conversion lens built into the camera and can select, for example, wide-angle shooting and telephoto shooting by switching, the applicant has filed a patent application No. 57-13953.
In No. 3, by switching the switching ring, at the wide-angle position, the focus guide is linked to the focus member to move the focus, and at the telephoto position, the auxiliary focus guide is placed between the focus guide and the focus member. A new focusing device has been introduced that allows the conversion lens to face the rear of the main lens, making it easy to extend lenses in different positions, allowing the interlocking structure with the focus mechanism to be aligned in a straight line, and making the camera more compact. Proposed.

[Purpose of the invention]

The present invention relates to an improvement of such a device, and its basic object is to provide a lens switching device that can quickly and accurately switch the focal length by one-touch switching rotation of the switching ring. be.

[Structure of the invention]

For this reason, the present invention includes a lens barrel and a switching ring that fits the lens barrel in a retractable manner, and a main lens is disposed at the front of the lens barrel, and the main lens has a focus slider on the lens barrel. It is supported by a focus guide that is movably supported and can be linked to a focus member on the camera body side, and a conversion lens is disposed at the rear of the lens barrel, and the conversion lens can be moved in and out of the optical path by the lens barrel. The switching ring includes a first cam that moves the lens barrel between an extended position and a retracted position in conjunction with the switching rotation, and a first cam that moves the camera body in conjunction with the switching rotation of the switching ring. A second cam that allows the auxiliary focus guide supported by the side switching member to face between the focus guide and the focus member, and a third cam that allows the conversion lens to face the optical path. It is.

〔Example〕

Embodiments of the invention will now be described in detail with reference to the accompanying drawings.

As shown in FIGS. 1 to 3, on the front of the camera body 1,
A cylindrical switching ring 2 that can be manually switched and rotated between a telephoto position T and a wide-angle position W is supported, and a cylindrical lens barrel 3 is fitted into the switching ring 2. 4 is stopped from rotating on the camera body 1 side, and a cam pin 6 implanted on the outer circumferential surface of the lens barrel 3 is fitted into a groove cam (first cam) 5 formed on the outer circumferential surface of the switching ring 2 to switch. Due to the switching rotation of the ring 2, the lens barrel 3 is caused to protrude straightly at the telephoto position T, and is caused to retract straightly when it is at the wide-angle position W.

A main lens 7 is disposed at the front of the lens barrel 3 and supported by a lens holder 8, and the lens holder 8 is supported by a bracket 9 protruding from the inner surface of the lens barrel 3 so as to be slidable for focusing in the axial direction. The focus guide 10 is fixed to the front end of the focus guide 10, and faces the axial center position of the lens barrel 3, that is, the optical path, with its rotation being restricted by a rotation restriction means (not shown).

A conversion lens 11 is supported and arranged in a lens holder 12 at the rear of the lens barrel 3, and the lens holder 12 is rotatably pivoted to a bracket 13 protruding from the inner surface of the lens barrel 3 with a pin 14. A cam pin 15 interlocked with a cam (third cam) 16 formed on the rear inner surface of the switching ring 2 rotates to the right to avoid the optical path when switching to wide-angle, and rotates to the left to move out of the optical path when switching to telephoto. It faces the optical path behind the lens 7, and together with the main lens 7 constitutes a telephoto lens.

On the other hand, a lens drive lever 17 is provided inside the camera body 1 to extend the lens holder 8 by coming into contact with the main focus guide 10 which is urged inward by a spring. - Locking lever 1 before release
At the same time, when the shutter is released, the cam 19 is rotated to the ranging information position by the lens preset mechanism, and then swung by the spring 20 when the locking lever 18 is released. The lens is advanced by pushing the focus guide 10 until the rising edge 17a is stopped against the cam 19.

Inside the camera body 1, a switching member 22 whose cam pin 22a abuts and interlocks with a cam (second cam) 21 formed on the rear inner surface of the switching ring 2 is pivoted by a pin 23 and biased to rotate counterclockwise by a spring 24. An auxiliary focus guide 25 is slidably fitted and supported in the upper part of the switching member 22, and when the switching ring 2 is at the wide-angle position W, it is rotated to the right by the cam 21 and moved to the telephoto position T. When switching, when the lens holder 8 and focus guide 10 protrude together with the lens barrel 3, the cam 21
, the auxiliary focus guide 25 is placed between the focus guide 10 and the lens drive lever 17, and in the same way as above, the lens drive lever <-17 pushes the focus guide 10 via the auxiliary focus guide 25. Extend the lens.

With the above configuration, the switching ring 2 is set to the wide-angle position W.
, the lens barrel 3 is recessed by the grooved cam 5, and the cam 16
Due to this, the lens holder 12 is in the □ retracted position outside the optical path,
Since the switching member 22 is in the retracted position by the cam 21 and the focus guide 10 directly contacts the lens drive lever 17, the lens drive lever 1 by the lens preset mechanism is
The focus guide 10 is pushed in accordance with the swing angle of 7.
Focusing is performed.

Next, when the switching ring 2 is switched to the telephoto position T, the lens holder 8 and the focus guide 10 are projected together with the lens barrel 3 by the grooved cam 5, and the switching member 22 is swung by the cam 21 to guide the auxiliary focus. 25 faces between the focus guide 10 and the lens drive lever 17, and at the same time the cam 16 moves the lens holder 12
The focal length of the main lens 7 is switched within the optical path behind the main lens 7, and a telephoto lens is formed, for example.

Then, since the auxiliary focus guide 25 comes into contact with the lens drive lever 17, the focus guide 10 is pushed by the auxiliary focus guide 25 in accordance with the swing angle of the lens drive lever 17 by the lens preset mechanism, and a focusing force r is applied. .

〔Effect of the invention〕

As is clear from the above description, in the present invention, when the switching ring is switched from the retracted position to the protruding position, the first cam of the switching ring protrudes the lens barrel to the protruding position, and the second cam causes the focus guide and the focus The auxiliary focus guide is placed between the main lens and the third cam, and the conversion lens is placed in the optical path behind the main lens, so the focal length can be changed with a one-touch operation of the switching ring. In addition, since the lens barrel, auxiliary focus guide, and conversion lens are linked to the cam of the switching ring, switching operations can be performed reliably and with high precision.

[Brief explanation of drawings]

1 is a perspective view of the lens switching device during wide-angle photography, FIG. 2 is a front view of FIG. 1, and FIG. 3 is a side sectional view of FIG. 2. 1... Camera body, 2... Switching ring, 3... Lens barrel, 5... Groove cam (first cam), 7... Main lens,
DESCRIPTION OF SYMBOLS 10... Focus guide, 11... Conversion lens, 16... Cam (3rd cam), 17... Lens drive lever, 21... Cam (2nd cam), 22...
...Switching member, 25...Auxiliary focus guide, ■-
...Telephoto position, W...Wide-angle position.

Claims (1)

[Claims] (1) A lens barrel and a switching ring that engages the lens barrel in a retractable manner; a main lens is disposed at the front of the lens barrel; the main lens is supported by the lens barrel so that the focus can be slid; A conversion lens is disposed at the bottom of the lens barrel, and the cough conversion lens is pivotably mounted on the lens barrel so as to be retractable from the optical path. In addition, the switching ring includes a first cam that moves the lens barrel between the protruding position and the retracted position in conjunction with the switching rotation, and a switching member on the camera body side in conjunction with the protrusion switching rotation of the switching ring. A lens switching device for a camera, characterized in that a second cam that allows an auxiliary focus guide supported by a lens to face between the focus guide and a focus member, and a third cam that allows a conversion lens to face an optical path are formed. Device.