JPH041533Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field of the Invention) The present invention relates to a lens barrel in which a plurality of movable frames are slidably guided on the inner peripheral surface of a fixed barrel.

(Background of the invention) As a conventional lens barrel, for example,
There is one disclosed in the -83724 publication. In such a lens barrel, as shown in FIG. 4 and FIG. A plurality of sliding legs 21 are disposed in the circumferential direction and fit into the inner peripheral surface 1a of the lens holding part 20 and extend in the optical axis direction. A notch 22 is provided through which the sliding leg (omitted) is inserted. The structure prevents the moving frame 2 from collapsing and prevents the moving frame 2 from interfering with other moving frames.

However, in such a conventional lens barrel, a completely cut-out notch 22 is provided between each sliding leg 21, so that light rays A, B, etc. shown in FIG. It enters the inner circumferential surface 1a of the fixed cylinder 1 through the portion 22, is reflected by the inner circumferential surface 1a, and reaches the film surface through each notch 22, thereby causing flare, ghost, etc. However, there was a problem that the optical performance was adversely affected.

(Purpose of the invention) The present invention was developed by focusing on the problems of the conventional technology, and is designed to block the reflected light rays from the inner circumferential surface of the fixed cylinder into which the sliding leg of the moving frame is fitted. It is an object of the present invention to provide a lens barrel that prevents occurrence of flare, ghost, etc.

(Summary of the invention) The gist of the invention for achieving the above object is as follows: A fixed lens barrel; A first lens holding part that holds a lens; A first lens holding part that holds a lens; , a plurality of first sliding legs extending in the optical axis direction and fitting into the inner circumferential surface of the fixed lens barrel, and a first movement slidably guided by the inner circumferential surface of the fixed lens barrel. a frame; a second lens holding part for holding a lens; and a plurality of lenses arranged at a certain interval in the circumferential direction of the lens holding part, extending in the optical axis direction and fitting into the inner circumferential surface of the fixed lens barrel. a second movable frame having a second sliding leg portion and slidably guided by the inner peripheral surface of the fixed lens barrel, the distance between the first movable frame and the second movable frame being The lens mirror has the first and second movable frames disposed within the fixed lens barrel such that the second sliding legs are inserted between the first sliding legs when the lens barrel is narrowed. In the tube, a space is left between each sliding leg of either one of the first and second moving frames for the first and second sliding legs to pass through, and each sliding The present invention resides in a lens barrel characterized in that a light shielding portion is provided on the inner circumferential side of the leg portion to connect the respective sliding leg portions.

In the lens barrel, the light rays reflected from the inner circumferential surface of the fixed barrel into which the sliding legs of the movable frame are fitted are blocked by the light shielding part, thereby preventing the occurrence of flare, ghost, etc. Moreover, there remains a space between each sliding leg for the sliding leg of another moving frame to pass through, so that each moving frame does not interfere with the other moving frame.

(Example) Hereinafter, each example of the present invention will be described based on the drawings. Note that the same parts as in the conventional example are given the same reference numerals.

1 and 2 show a first embodiment of the present invention, in which FIG. 1 is a longitudinal sectional view of a zoom lens barrel, and FIG. 2 is a sectional view showing essential parts.

As shown in FIG. 1, movable frames 2 and 3 are held on the inner peripheral surface 1a of the fixed barrel 1 of the zoom lens barrel 10 so as to be slidable in the optical axis direction.

The movable frame 2 holds a second lens group L2 at the front and a fourth lens group L4 at the rear.

A holding frame 4 holding the first lens group L1 is screwed onto the front end of the moving frame 3.

A holding frame 5 holding the third lens group L3 is fixed to the fixed barrel 1.

The inner circumference of the zooming ring 6 fits into the outer circumference of the fixed barrel 1. Pin 6 embedded in zooming ring 6
The zooming ring 6 can only rotate due to the engagement of the ring a with the circumferential groove 1b formed in the fixed cylinder 1.

The pin 2a implanted in the movable frame 2 is inserted into the straight groove 1c of the fixed cylinder 1 and the cam groove 6 of the zooming ring 6.
b.

The pin 3a implanted in the movable frame 3 is inserted into the straight groove 1d of the fixed cylinder 1 and the cam groove 6 of the zooming ring 6.
It is engaged with c.

As shown in FIGS. 1 and 2, the movable frame 2 includes a lens holding portion 20 that fits into the inner circumferential surface 1a of the fixed barrel 1 and extends in the optical axis direction from a lens holding portion 20 that holds the second lens group L2. A plurality of sliding legs 21 are arranged in the circumferential direction. The inner peripheral side of each sliding leg 21 is a light shielding part 2
3, and between each sliding leg 21 there is a notch 2 through which the sliding leg 31 of the moving frame 3 is inserted.
2 is provided.

Similarly, the movable frame 3 is provided with a plurality of sliding legs 31 in the circumferential direction that fit into the inner circumferential surface 1a of the fixed cylinder 1 and pass through the notch 22. 3
1 is provided with a cutout 32 through which each sliding leg 21 of the moving frame 2 is inserted.

In the zoom lens barrel 10 having the above configuration,
When the zooming ring 6 is rotated, the moving frame 2 slides to the left in the figure, and the moving frame 3 slides to the right in the figure, thereby performing a zooming operation. At this time, each sliding leg 21 of the moving frame 2 is inserted into the notch 32 of the moving frame 3.
Each sliding leg 31 of the moving frame 3 is connected to the notch 2 of the moving frame 2.
Since the movable frames 2 and 3 are inserted through the movable frames 2 and 3 respectively, there is no interference between the movable frames 2 and 3 during the zooming operation.

Furthermore, the light rays C, D, etc. that enter the inner circumferential surface 1a of the fixed cylinder 1 through the notch 22 of the movable frame 2 and are reflected by the inner circumferential surface 1a are blocked by the light shielding section 23, These light rays C, D, etc. are prevented from reaching the film.

Next, a second embodiment of the present invention will be described based on FIG.

This second embodiment is fixed in the case of the first embodiment by providing a cylindrical light shielding part 24 protruding from the movable frame 2 on the opposite side of the light shielding part 23 with respect to the lens holding part 20. A part of the light beam incident on the inner circumferential surface 1a of the cylinder 1 can be blocked, and the occurrence of flare, ghost, etc. can be more reliably prevented than in the first embodiment. Here, as shown in FIG. 3, the light ray E that penetrates deeper than the light rays C and D is reflected by the inner circumferential surface 1a and then blocked by the wall surface of the mount portion 1e, and does not reach the film. do not.

It goes without saying that the present invention is applicable not only to zoom lens barrels but also to other lens barrels.

(Effect of the invention) According to the lens barrel according to the invention, since the light shielding part is provided which connects the inner peripheral side of each sliding leg of the movable frame, the sliding leg of the movable frame fits into the fixed It is possible to block the reflected light rays from the inner peripheral surface of the cylinder, and it is possible to prevent flare, ghost, etc. from occurring.

Furthermore, by providing the movable frame with a cylindrical light shielding part protruding from the side opposite to the light shielding part with respect to the lens holding part, occurrence of flare, ghost, etc. can be more reliably prevented.

[Brief explanation of the drawing]

Figures 1 and 2 show a first embodiment of the present invention, where Figure 1 is a longitudinal sectional view, Figure 2 is a sectional view showing the main parts, and Figure 3 is a second embodiment of the invention. FIG. 4 and FIG. 5 show a conventional example, where FIG. 4 is a longitudinal sectional view and FIG. 5 is a sectional view of main parts. 1...Fixed barrel, 1a...Inner peripheral surface, 2...Moving frame, 10...Zoom lens barrel (lens barrel),
20...Lens holding part, 21...Sliding leg part, 22
... Notch portion, 23 ... Light shielding portion, 24 ... Cylindrical light shielding portion.

Claims (1)

[Claims for Utility Model Registration] (1) A fixed lens barrel; A first lens holding part that holds a lens; a first moving frame having a plurality of first sliding legs that fit into the inner circumferential surface of the fixed lens barrel and slidably guided by the inner circumferential surface of the fixed lens barrel; holding a lens; a second lens holding part; a plurality of second sliding legs disposed at certain intervals in the circumferential direction of the lens holding part, extending in the optical axis direction and fitting into the inner circumferential surface of the fixed lens barrel; and a second movable frame slidably guided by the inner circumferential surface of the fixed lens barrel, and when the distance between the first movable frame and the second movable frame narrows, In the lens barrel, the first and second movable frames are arranged in the fixed lens barrel such that each of the second sliding legs is inserted between each of the first sliding legs, the first, A space is left between each sliding leg of either one of the second moving frames for the first and second sliding legs to pass through, and a space is left on the inner peripheral side of each sliding leg of the second moving frame. A lens barrel characterized in that a light shielding portion is provided to connect the respective sliding leg portions. (2) The lens according to claim 1, wherein the one movable frame is provided with a cylindrical light shielding part protruding from the lens holding part on the opposite side of the light shielding part. lens barrel.