JPH02213811A - Position adjusting device for lens group - Google Patents

Abstract

PURPOSE:To facilitate the fine adjustment of a moving lens by implanting a guide pin in an adjusting plate provided on a lens support plate slidably in an axial direction, and adjusting the position of the adjusting plate with an eccentric pin. CONSTITUTION:The tracking of a 1st lens group 16 and a 2nd lens group 20 is adjusted on the wide-angle side. Then the tracking of a 3rd lens group 27 is adjusted on the telephoto side. When the 3rd lens group 27 is moved for fine adjustment at such a time, the eccentric pin 40 is rotated slightly by a driver, etc., from outside the lens barrel and then only the lens frame 28 is moved forth and back since the adjusting plate 31 is restricted by a cam groove 14C through the pin 32. A fixing screw 34 is clamped after the adjustment to fix the adjusting plate 31 to the lens support frame 28. Thus, the lens support frame of the moving lens group is easily moved for the fine adjustment from outside the lens barrel, so the tracking of the moving lens group is easily adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lens group position adjusting device, and more particularly to a lens group position adjusting device suitable for a zoom lens of a compact camera.

[Conventional technology]

Recently, bifocal compact cameras and compact cameras with a 2x zoom lens have been proposed.

The lens barrel of such a camera is configured such that a movable barrel is movable back and forth within a fixed barrel, and the first lens group is fixed to the movable barrel, and the second lens group is moved back and forth according to the position of the movable barrel using a cam etc. It is now possible to move and zoom. In such a bifocal camera or a compact camera with a 2x zoom lens, there are two lens groups, a lens group and a second lens group, and their tracking adjustment is relatively easy.

[Problem to be solved by the invention]

However, a compact camera with a high-power zoom lens requires two movable lens groups in addition to the first lens group fixed to the movable barrel, making the structure complex and making tracking adjustment difficult. That is, in a compact camera with a high zoom ratio, the first lens group is fixed to the front of the movable barrel, and the second and third lens groups are arranged to be movable in the axial direction within the movable barrel. When the movable barrel including the lens group moves back and forth due to the rotation of , the second and third lens groups are also moved back and forth by the cam barrel in accordance with the zoom ratio. Therefore,
In such a compact camera with a high-magnification zoom lens, tracking adjustment is first performed with the first lens group and second lens group on the wide-angle side, and then tracking adjustment is completed with the first lens group and second lens group. After that, in the telephoto state, the third lens group is adjusted for tracking relative to the first and second lens groups to position the lens. Therefore, such a mechanism requires a mechanism that can easily finely move the lens support frame from the outside of the lens barrel.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a lens group position adjustment device that can easily finely adjust the moving lens with a simple mechanism in tracking adjustment of the moving lens group. It is said that

[Means to solve problems]

The present invention provides guide grooves 10A and IOB in the axial direction.

A fixed cylinder (10) with 10C formed thereon and a cam groove 1 on the outer periphery.
A cam cylinder (14) formed with 4A, 14B, and 14C is rotatably supported by a fixed cylinder (10), and a cam cylinder (14) is supported by a guide bar (30) in a movable cylinder (12) so as to be axially movable and extends outward. The guide pin (32) planted in the direction of the fixed tube (10
) guide groove 10C and cam 11114 of cam cylinder (14)
In the zoom lens barrel, the guide pin (32) includes a lens support frame (28) that is fitted into the lens support frame (28) and is moved in the axial direction by rotating the cam barrel (14).
The adjustment plate (31) is installed on the lens support frame (28) so as to be slidable in the axial direction, and the adjustment plate (31) has an eccentric pin (
40) is characterized in that the position can be adjusted.

[Effect]

In the present invention, the adjustment plate (3) is attached to the lens support frame (28).
1) is provided so as to be freely movable in the axial direction, and a guide pin (32) is protruded from the adjustment plate (31), and is fitted into the cam groove (14C) of the cam cylinder (14), and the adjustment plate (31) Since it can be moved slightly by the eccentric pin (40), it can be easily adjusted.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a lens group position adjusting device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a zoom lens barrel to which a lens group position adjustment device according to the present invention is applied, in which a movable barrel 12 is supported on a fixed barrel 10 so as to be slidable in the axial direction, and a fixed barrel 10 is supported to be slidable in the axial direction. A cam cylinder 14 is rotatably supported on the outer periphery of the cam cylinder 14 . The fixed barrel 10 is fixed to the front part of a camera body (not shown) by a flange 11.11 provided at the right end in FIG.

Figures 2 and 3 show the cross-sectional structure of the zoom lens barrel shown in Figure 1. Figure 2 shows the inside of the zoom lens barrel in the wide position, and Figure 3 shows the inside of the zoom lens barrel in the tele position. It shows the cross-sectional structure. At the front of the movable tube 12 is a group of lune 1.
6 is fixed via a lens support frame 18. Guide pins 20, 20, 20 (
The guide pin 20 passes through the straight groove 10A formed in the axial direction of the fixed cylinder 10, and also extends through the first straight groove 10A of the cam cylinder 14.
It is fitted into the cam groove 14A. Therefore, when the cam barrel 14 is rotated, the movable barrel 12 moves between the straight groove 10A and the cam barrel 1.
It is regulated by the cam groove 14A of No. 4 so that it can move in the front-back direction.

The lens support frame 22 of the second lens group 20 is attached to a movable frame 23, and this movable frame 23 is supported by a guide bar 24 so as to be freely movable in the axial direction. Guide pin 2 is attached to the moving frame 23.
6 is planted, and this guide pin 26 fits into the straight groove 10B of the fixed cylinder 10 and also fits into the cam groove 1 of the cam cylinder 14.
It is inserted into 4B. Therefore, when the cam barrel 14 rotates, the second lens group 20 moves into the straight groove 10B of the fixed barrel 10.
, is regulated by the cam groove 14B of the cam cylinder 14 and moves back and forth. A lens support frame 22 of the second lens group 20 is attached to this moving frame 23 . The lens support frame 22 of the second lens group 20 is movably supported with respect to the movable frame 23 via a guide bar 24A, so that the focal length can be adjusted. The lens support frame 22 is moved back and forth by a cam 24B.

The third lens group 27 is connected to the movable barrel 1 via a lens support frame 28.
It is supported so as to be freely movable in the axial direction via two guide bars 30 arranged in the axial direction. In the third lens group 27, as shown in detail in FIG. It is fitted into the cam groove 14C of the 10C1 cam groove 14. Therefore, when the cam cylinder 14 rotates, the third lens group 27 moves straight into the straight groove 1.
It is regulated by 0C and the cam groove 14C of the cam cylinder 14 to move back and forth. A drive ring 37 is fixed to the outside of the cam cylinder 14, and a gear portion 37A is formed on this drive ring 37, so that rotational force from a drive motor (not shown) is transmitted.

In FIG. 5, a mechanism for moving the adjusting plate 31 is shown. A long hole 31A is formed in the adjustment plate 31.
A fixing screw 34 is provided in A for fixing the adjustment plate 31 to the lens support frame 28. Further, the adjustment plate 31 is disposed in the guide groove 36, 36 of the lens support frame 28, so that the adjustment plate 31 can freely slide in the axial direction.
It is installed on 8. Furthermore, the adjusting plate 31 has a hole 38.
is formed, and an eccentric pin 40 is inserted into the hole 38. That is, the eccentric pin 40 includes a cylindrical body 42 and a pin 44 located eccentrically from the center of the cylindrical body 42. The eccentric portion 44 is inserted into the hole 38 and fitted into the elongated hole 46 of the lens support frame 28 . When the eccentric pin 40 is rotated in such a state, the lens adjustment plate 31 moves a36.
36 to move back and forth in the axial direction.

The operation of the lens group position adjusting device according to the present invention configured as described above is as follows.

First, tracking adjustment between the first lens group 16 and the second lens group 20 is performed on the large side. Next, Luns Group 16
, tracking adjustment of the third lens group 27 with respect to the second lens group 20 is performed on the telephoto side. In the fine adjustment at this time, if you want to finely move the third lens group 27, slightly rotate the eccentric pin 40 from the outside of the lens barrel with a screwdriver, etc., and the adjustment plate 31 is regulated by the cam groove 14C via the pin 32. Therefore, only the lens frame 28 is moved back and forth. After adjustment, the fixing screw 34 is tightened, and the adjusting plate 31 is fixed to the lens support frame 28.

〔Effect of the invention〕

As described above, according to the lens group position adjustment device according to the present invention, the lens support frame of the movable lens group can be easily finely moved from the outside of the lens barrel, so that tracking adjustment of the movable lens group can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a lens barrel to which a lens group position adjustment device according to the present invention is applied, FIG. 2 is a sectional view of a zoom lens barrel in a wide position to which the present invention is applied, and FIG. A cross-sectional view of the lens @ barrel according to the present invention at the tele position,
FIG. 4 is a perspective view showing the structure of the lens support frame of the third lens group, and FIG. 5 is a perspective view showing the adjustment mechanism of the lens support frame of the third lens group. 10... fixed tube, 12... movable tube, 14.
...Cam tube, 16..Luns group, 20..2nd
Lens group, 27... Third lens group, 28... Lens support frame, 31... Adjustment plate, 32... Guide pin, 40... Eccentric pin.

Claims (1)

[Scope of Claims] A fixed cylinder in which a guide groove is formed in the axial direction, a cam cylinder in which a cam groove is formed on the outer periphery and is rotatably supported by the fixed cylinder, and a guide bar that moves in the axial direction within the fixed cylinder. a lens support frame in which a guide pin freely supported and planted outward is fitted into a guide groove of a fixed cylinder and a cam groove of a cam cylinder, and is moved in the axial direction when the cam cylinder is rotated; The zoom lens barrel is characterized in that the guide pin is mounted on an adjusting plate provided on the lens support frame so as to be slidable in the axial direction, and the position of the adjusting plate is adjustable by an eccentric pin. Lens group position adjustment device.