JPS62184420A - Zoom lens barrel - Google Patents

Abstract

PURPOSE:To decrease the number of components, to shorten a manufacture time, and to reduce the cost by uniting a click mechanism and a switch mechanism for macro detection. CONSTITUTION:When a zoom ring 1 is rotated from the changeover position of a zoom photographic range to the changeover position of a macrophotographic range, the tip part 23 of a leaf spring 21 abuts on the step part 33 of the inner peripheral surface of the zoom lens 1. When the zoom photographic range is switched to the macrophotographic range, the leaf spring 21 is deformed elastically by the inner peripheral surface of the zoom ring, so the rotary load on the zoom ring increases and a clock mechanism is realized. Further, the leaf spring 21 deforms elastically to bring a contact 34 provided to the leaf spring 21 into contact with the other leaf spring 35, so a switch for macro detection is realized. Thus, the click mechanism and switch for macro detection are united, so the number of components is decreased and the manufacture time is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a zoom lens barrel capable of macro photography;
It is useful for video cameras and the like.

2. Description of the Related Art In recent years, zoom lenses for video cameras that are designed to enable macro photography have been widely used.

Normally, in such a zoom lens, one of the variable power lens group and the correction lens group, which are movable lens groups, is set, for example, the variable power lens group is set to the wide-angle side or the telephoto side, and then the correction lens group is set. By moving in the direction of the optical axis, it is possible to photograph a subject at a close distance. For this purpose, it is necessary to provide a cam groove for moving and adjusting the zoom lens in the macro photography range so as to extend to the cam groove in the zoom photography range. In a lens barrel configuration having such a cam groove, a click mechanism is provided to prevent the movable lens group from unnecessarily moving to the macro photography range during manual zooming or electric zooming in normal photography.

A conventional zoom lens barrel will be described below with reference to the drawings. FIG. 5 is a sectional view of a conventional zoom lens barrel, and FIG. 6 is a sectional view taken along the line Y-Y' in FIG. By moving these lens groups in the optical axis direction at appropriate intervals, the magnification of the subject image can be changed. In FIG. 5, the variable magnification lens group L1 and the correction lens group L2 are respectively mounted on lens frames 6 and 7 supported by a plurality of guide rods 5 suspended between a fixed lens barrel 2 and a fixed member 3. It is kept fixed. The cam tube 4 has cam grooves 11 and 12 that engage with each of the pin 9 implanted on the lens frame 6 and the pin 10 implanted on the lens frame 7, and the cam tube 4 rotates. The variable magnification lens group L1, which is a movable lens group,
The lens frames 6 and 7, which each hold the correction lens group L2, are moved in the optical axis direction.

The cam cylinder 4 is provided with a pin 8, which passes through a slit 13 provided in the circumferential direction of the fixed mirror 2 and engages with a notch 14 in the optical axis direction of the zoom ring 1. There is. The fixing member 3 restricts the movement of the zoom ring 1 in the optical axis direction, and also restricts the movement of the cam barrel 4 in the optical axis direction.

Further, in FIG. 6, a plate spring 16 is fixed perpendicularly to the optical axis direction on the outer circumferential surface of the fixed lens barrel 2 with screws 16, and its tip 17 is bent into a substantially U-shape. When the zoom ring 1 is rotated to the switching position from the zoom shooting range to the macro shooting range, a stepped portion 18 is provided on the inner peripheral surface of the zoom ring 1 where the tip 17 of the plate spring 15 is located, and the zoom shooting range 19 is When the zoom ring 1 is rotated within the camera, the radius of the inner circumferential surface of the zoom ring 1 on which the tip 17 is located is increased so that the tip 17 of the plate spring 15 does not come into contact with the zoom ring 1. When the zoom ring 1 is rotated within 2o, the inner peripheral surface of the zoom ring 1 comes into contact with the tip 17 of the plate spring 15, and the tip 17 is rotated so that the plate spring 15 is elastically deformed. This is done by reducing the radius of the inner peripheral surface of the zoom ring 1.

With this configuration, when trying to rotate the zoom ring 1 from the zoom shooting range 19 to the macro shooting range 20, the zoom ring 1 is rotated between the zoom shooting range 19 and the macro shooting range 2.
At the switching position between the zoom ring 1 and the zoom ring 1, the tip 17 of the plate spring 16 comes into contact with the step 18 on the inner peripheral surface of the zoom ring 1, thereby increasing the rotational load. Such a lick mechanism allows the operator to recognize the switching position between the zoom shooting range and the macro shooting range during manual zooming, or allows the clutch mechanism provided in the zoom drive system (not shown) to slip during electric zooming. This prevents unnecessary switching to the macro shooting range.

In addition, a switch base 2 attached to the outer peripheral surface of the fixed lens barrel 2
A lever 29 is attached to the zoom ring 8 toward the zoom ring 1. When the zoom ring 1 is rotated to the macro photography range, the lever 29 is elastically deformed so that the contact 3° provided on the lever 29 comes into contact with another contact 31 attached to the switch board. A convex portion 32 is provided on the outer peripheral surface. This switch mechanism detects the macro photography state and stops the autofocus function.

Problems to be Solved by the Invention However, in the above configuration, since the click mechanism and the macro detection switch mechanism are provided separately, there are problems in that the number of parts increases and the manufacturing time increases. was.

In view of the above-mentioned problems, the present invention provides a zoom lens barrel that can reduce the number of parts and shorten manufacturing time.

Means for Solving the Problems In order to solve the above problems, the zoom lens barrel of the present invention includes a fixed lens barrel and a conductive elastic body attached to the fixed lens barrel so as to be elastically deformable. a lens group movable in the optical axis direction relative to the fixed lens barrel; and a lens group rotatably fitted to the fixed lens barrel, and the lens group is moved by rotation. A zoom ring that is capable of zoom photography and macro photography and is provided with a convex portion to elastically deform the arm during macro photography, and the fixation so that a part of the arm is crimped when the arm is elastically deformed. It is constructed with a conductive member attached to the lens barrel.

Function: With the above-described configuration, the present invention can integrate the click mechanism and the macro detection switch mechanism, thereby making it possible to reduce the number of parts and manufacturing time.

Example Below, regarding a zoom lens barrel according to an example of the present invention,
This will be explained with reference to the drawings. FIG. 1 is a cross-sectional view of a zoom lens barrel according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line X-X in FIG. 1, and FIG. 3 is a fixed lens barrel according to an embodiment of the present invention. Main part plan view, Figure 4 (a), (b)
, (C) is an enlarged view of the main part in each operating state in FIG. 2. In the figure, the same parts as in FIGS. 5 and 6 are denoted by the same reference numerals, and redundant explanation will be omitted here.

In FIG. 2, a plate spring 21 made of a conductive elastic material is fixed perpendicularly to the optical axis direction on the outer peripheral surface of the fixed lens barrel 2 with screws 22, and its tip 23 can be bent into a substantially U-shape. be.

When the zoom ring 1 is rotated from the zoom shooting range to the macro shooting range switching position, a stepped portion 33 is provided on the inner peripheral surface of the zoom ring where the tip 23 of the plate spring 21 is located [FIG. 4(b)] ], the radius of the inner circumferential surface of the zoom ring 1 on which the tip 23 of the plate spring 21 is located is increased so that the tip 23 of the plate spring 21 does not come into contact with the zoom ring 1 when the zoom ring 1 is rotated within the zoom shooting range 19. [Figure 4 (,
)], when the zoom ring 1 is rotated within the macro shooting range 20, the inner circumferential surface of the zoom ring 1 comes into contact with the tip 23 of the plate spring 21, causing the plate spring 21 to elastically deform. Second, the radius of the inner peripheral surface of the zoom ring where the tip portion 23 is located is made smaller. Then, when the plate spring 21 is elastically deformed within the macro photographing range 2o, another plate made of a conductive elastic body is attached to the fixed lens barrel 2 so that the contact point 34 provided on the plate spring 21 comes into contact with the plate spring 21. A shaped spring 36 is attached with a screw 36 [see FIG. 4(c)]. One end of the plate springs 21 and 36 passes through a notch in the flange 37 of the fixed lens barrel 2 and exits to the zoom lens barrel, and each end is connected to a macro detection circuit (not shown) by a lead wire or the like. [See Figure 3].

Therefore, when the zoom ring 1 is rotated from the zoom shooting range to the macro shooting range switching position, the plate spring 2
1 comes into contact with the step 33 on the inner peripheral surface of the zoom ring 1 [see FIG. 4(b)], and in order to switch from the zoom shooting range to the macro shooting range, the inner periphery of the zoom ring 1 must Since the plate spring 21 is elastically deformed by the surface, the rotational load on the zoom ring becomes large and it functions as a click mechanism. Further, as the plate spring 21 is elastically deformed, the contact point 34 provided on the plate spring 21 is
By coming into contact with the other plate spring 36, it functions as a macro detection switch.

With the above configuration, the shift mechanism and the macro detection switch can be integrated, so it is possible to reduce the number of parts and shorten the manufacturing time.

Effects of the Invention As described above, according to the present invention, it is possible to reduce the number of parts and shorten manufacturing time, and it is possible to obtain excellent effects such as greatly contributing to cost reduction.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a zoom lens barrel according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line X-Xt in FIG. Figure 4(a)
, (B), and (C) are enlarged views of the main parts of Fig. 2, Fig. 6 is a sectional view of a conventional zoom lens barrel, and Fig. 6 is taken along y-y of Fig. 6.
It is a y-line sectional view. 1...Zoom ring, 2...Fixed lens barrel, 4...Cam barrel, 21...Plate spring,
23...Tip part, 33...Step part, 34
...Contact, 36...Plate spring. Name of agent: Patent attorney Toshio Nakao 1 person 2-
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Claims (1)

[Claims] a fixed lens barrel; an arm including a conductive elastic body attached to the fixed lens barrel so as to be elastically deformable; a lens group movable in the optical axis direction with respect to the fixed lens barrel; The arm is rotatably fitted to the lens barrel, and when rotated, the lens group can be moved to enable zoom photography and macro photography, and a convex portion is provided to elastically deform the arm during macro photography. 1. A zoom lens barrel comprising: a zoom ring; and a conductive member attached to the fixed barrel so that a part of the arm is pressed against the arm when the arm is elastically deformed.