JPH07111496B2 - Actuating switch device in automatic focus adjustment mechanism of zoom lens - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an operation switch device in an automatic focus adjusting mechanism for a zoom ring, and more specifically, for operating the automatic focus adjusting mechanism by moving the zoom ring in the optical axis direction. The present invention relates to this type of switch device.

[Prior Art] A conventional operation switch device in an automatic focus adjustment mechanism of a zoom lens is provided with a switch member (for example, push button type) on a side portion or an upper portion of a lens barrel, and the adjustment mechanism is manually operated. The type that actuates was common.

There is also a model in which the operation switch device of the automatic focus adjustment mechanism is built into the camera body. In this model,
1 when the shutter button is operated in 2 steps and lightly pressed
The adjusting mechanism is operated in the second stage, and the shutter is operated in the second subsequent stage.

[Problems to be Solved by the Invention] In the former operation switch device, when operating the zoom ring at the same time, an operation is performed on a switch member provided at a position different from the zoom ring. Since it was necessary to move the fingers, the operability was not good. In particular, a person unfamiliar with the camera being used cannot completely remember the position of the switch member, and thus has to take his / her eyes off the viewfinder one by one to operate the switch member.

Further, in the latter operation switch device, there is a problem that the automatic focus adjusting mechanism does not work reliably when the shutter button is pushed too fast. This is because, in the case of this structure, first, the operation of the automatic focus adjustment mechanism in the first step of the shutter button must be performed to completely focus on the subject, and then the shutter must be operated in the second step of the shutter button. This is because, if the shutter button is pressed too fast, the shutter will operate even if focusing is incomplete.

The present invention has been made in consideration of the above problems of the prior art, and an object of the present invention is to provide an operation switch device in an automatic focus adjusting mechanism of a zoom lens, which is suitable for simultaneous operation with a zoom ring and has few erroneous operations. And

[Means for Solving the Problems] In order to achieve the above object, according to the present invention, in an automatic focus adjusting mechanism for a zoom lens that performs zooming by rotating the zoom ring, the zoom ring is manually operated in the optical axis direction. It was possible to move to. Also, a switch member that opens and closes by moving the zoom ring in the optical axis direction is linked to the zoom ring, and the opening and closing of the switch member activates and deactivates the automatic focusing mechanism.

[Operation] In the operation switch device according to the present invention having the above configuration, after the zoom ring is rotated for zooming,
If the zoom ring is moved in the direction of the optical axis with the hand holding the zoom ring, the switch member can be opened and closed to operate or cancel the automatic focus adjustment mechanism.

[Embodiment] FIG. 1 is a cross-sectional view showing a zoom lens having an automatic focus adjustment mechanism operable by an embodiment of an operation switch device according to the present invention. In the figure, the part on the camera body side is irrelevant to the main part of the present invention and is therefore omitted.

Four lens groups (shown as a single lens for convenience of illustration) are arranged in the lens barrel 10 of the zoom lens so that the optical axes are aligned, and these are arranged from the object side to the objective lens group.
The order is L1, variator lens group L2, compensator lens group L3, and relay lens group L4.

A variator lens group L2 and a compensator lens group L3 are usually used for zooming, and zooming is performed by relative approach and separation of both lens groups L2 and L3 in the optical axis direction. The variator lens group L2 is connected to the cam barrel 16 by the supporting and moving piece 12, and the compensator lens group L3 is connected to the cam barrel 16 by the supporting and moving piece 14. Both pieces
12, 14 are movably arranged in a cam groove (not shown) of a predetermined shape formed in the cam barrel 16, and when the cam barrel 16 is rotated via a zoom ring 18 described later, both pieces 12 , 14 move along the cam groove, and both lens groups L2, L3 relatively approach,
It is designed to separate from each other.

A zoom ring 18 is arranged on the outermost periphery of the lens barrel 10 and is connected to the cam barrel 16 by a connecting pin 20. Connecting pin 20
The upper end portion of the zoom ring 18 is engaged with the long groove 22 formed in the zoom ring 18, and therefore the zoom ring 18 is movable in the optical axis direction with respect to the rest of the lens barrel 10 by manual operation within the range allowed by the long groove 22. Has become. Further, in the moving range of the zoom ring 18, the connection between the zoom ring 18 and the cam barrel 16 by the connecting pin 20 is maintained, so that the zoom ring 18 and the cam barrel 16 always operate integrally in the rotational direction.

A pocket collar 26 is disposed adjacent to the zoom ring 18 on the camera body side, and this forms an annular space 28 into which the reduced diameter portion 24 of the zoom ring 18 on the camera body side can be nested. The switch ring 30 is stored in the annular space 28,
The ring 30 is a zoom ring formed by a coil spring 32 provided on one side between the ring 30 and the wall on the camera body side.
Energized towards 18. Due to this biasing force, the switch ring 30 is constantly in contact with the zoom ring 18, and the zoom ring 18 is pushed to the end portion on the subject side which is in contact with a part (not shown) of the support member 11 of the objective lens group L1. It becomes a state (state shown in the figure).

On the other side of the switch ring 30, a switch member 36 is arranged between the upright portion 34 of the ring 30 and the wall portion on the camera body side, which controls the activation and deactivation of the automatic focusing mechanism. Be wired to. In the above-described state where the switch ring 30 is under the urging force of the coil spring 32, the switch member 36 is in an open state (off state) without the protrusion 38 thereof being pressed by the upright portion 34 of the ring 30. . Further, when the switch ring 30 is pushed through the zoom ring 18 against the urging force of the coil spring 32, the ring is pressed.
The protrusion 38 is pushed by the upright portion 34 of the switch 30, and the switch member 36 is brought into a closed state (on state).

In the above zoom lens, zooming is generally performed by rotating the zoom ring 18 in the state shown in which the zoom ring 18 is at the end on the object side. After zooming, if the zoom ring 18 is pulled by the hand holding the zoom ring 18 in the direction of the optical axis to the right in the figure, the switch ring 30 is pushed in the collar 26 and the switch member 36 is closed. , The automatic focus adjustment mechanism is activated. When the pulling force of the zoom ring 18 is released, the zoom ring 18 and the switch ring 30 are returned to the positions shown by the biasing force of the coil spring 32, the switch member 36 is opened, and the automatic focus adjustment mechanism is released. . During these periods, the user does not have to release the zoom ring 18.

EFFECTS OF THE INVENTION According to the operation switch device of the present invention, when the operation operation of the automatic focus adjustment mechanism is performed in parallel with the zooming, the operation can be performed without releasing the hand from the zoom ring. Is good, and even if you are unfamiliar with the camera you are using, you do not have to take your eyes off the viewfinder. Further, unlike the above-described operation switch device integrated with the shutter button, since it is a single operation switch device that is operated by movement of the zoom ring in the optical axis direction, malfunctions are reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a zoom lens equipped with an automatic focus adjustment mechanism operable by an embodiment of an operation switch device according to the present invention. 10 …… Lens tube, 16 …… Cam tube, 18 …… Zoom ring, 30…
… Switch ring, 36 …… Switch member, L1 …… Objective lens group, L2 …… Variator lens group, L3 …… Compensator lens group, L4 …… Relay lens group

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical indication G03B 13/36

Claims (1)

[Claims] 1. An automatic focus adjusting mechanism for a zoom lens that performs zooming by rotating a zoom ring, wherein the zoom ring is movable in the optical axis direction by a manual operation, and is opened and closed by moving the zoom ring in the optical axis direction. Link the switch member to the zoom ring,
An operation switch device characterized in that the automatic focus adjustment mechanism is operated and released by opening and closing the switch member.