JPH06102446A - Lens barrel - Google Patents

Abstract

PURPOSE:To obtain a lens barrel constituted of small number of parts and having the high degree of freedom. CONSTITUTION:This lens barrel is provided with a guiding barrel 1 having a cam 1a; a moving barrel 2 having a double-level forward and backward sliding draw cam 2a molded by deviating the diameter positions before and behind the cam 1a; the lens barrel 3 moved by the cam 1a of the guiding barrel 1 and the cam 2a of the moving barrel 2; and a roller 4 integrally having a contact part 4c or a fitting part with respect to the cam 1a of the guiding barrel 1, a contact part coming in contact with a cam surface being the reference of the cam 2a of the moving barrel 2, and an elastic part pressing the contact part to the cam surface, and also having a positioning pin for regulating a rotational angle position and attached to the lens barrel 3 through a roller shaft 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel used in cameras, video cameras and the like.

[0002]

2. Description of the Related Art It is generally known that when a cam is molded on a molded component forming a lens barrel, the cam is provided with a taper so as not to cause an undercut when the die is removed in the radial direction. In this case, the roller is also tapered, and the tapered portion of the roller is urged by the urging spring against the tapered portion of the cam. When the other moving group is to be moved by the difference between the cams of the two mold parts in one lens system, a moving group configuration as shown in FIG. 6 can be considered.

In FIG. 6, 51 is a guide cylinder having a taper cam 51a for moving a lens barrel 53 holding a lens 59 in the optical axis direction, and 52 is another lens group 60.
Can be driven by a cam cylinder, a moving cylinder roller, and the like (not shown), and the lens barrel 53 can be driven.
A moving barrel having a differential taper cam 52a for moving the lens, 58 a roller shaft attached to the lens barrel 53, 54,
Reference numeral 55 denotes a roller shaft 58 which is attached to the lens barrel 53, and has tapered taper rollers in contact with the taper cam 51a and the differential taper cam 52a, and 56 and 57 are urging springs for urging the taper rollers 54 and 55. is there.

When the moving barrel 52 is driven straight by a cam barrel, a moving barrel roller, etc. (not shown), the lens barrel 53 moves while rotating along the intersection of the two tapered cams 51a, 52a.

Next, the differential taper cam 52a of the movable barrel 52
FIG. 7 shows the configuration of the moving group in the case of having a stepped front and rear slide removal cam in which the front and rear of the cam are molded by different molding dies. In FIG. 7 in which the same parts as those in FIG. 6 are denoted by the same reference numerals and duplicate description is omitted, 61 holds the lens group 60 and can be driven straight by a cam cylinder, a moving cylinder roller or the like (not shown). Also, the differential cam 61a for moving the lens barrel 53 is a moving barrel in which the front and rear of the cam are stepped front and rear slide removal cams formed by another forming mold by shifting the radial position, and 64 is the lens mirror. A roller shaft 62 attached to the cylinder 53, a roller 62 attached to the lens barrel 53 by a roller shaft 64, and in contact with the differential cam 61a of the moving cylinder 61 and the taper cam 51a of the guide cylinder 51, 63 is a taper portion of the roller 62. The taper cam 51a of the guide cylinder 51
An urging spring 65 urges the roller 62 against the differential cam 61a.

Because of the nature of the molding method, the cam width of the stepped front / rear slide removal cam that the moving barrel 61 has is not stable, so the biasing spring 63 is provided with the lens barrel through the roller 62 and the roller shaft 64. 53 is urged to the reference surface of the cam.

When the moving barrel 61 is driven straight by an unillustrated cam barrel, moving barrel roller, etc., the lens barrel 53 moves while rotating along the intersection of the taper cam 51a and the differential cam 61a.

[0008]

However, in the conventional example shown in FIG. 6 in which the movable cylinder is composed of the tapered cams,
The outer cam width of the taper cam becomes wider, and the restrictions on the overall cam arrangement and the like increase. There is also a problem that the number of parts such as independent rollers and bias springs increases and assembly becomes difficult.

Further, in the conventional example shown in FIG. 7 of the moving barrel structure in which the cam of the moving barrel is formed by a stepped front and rear slide removal cam, and a spring is provided for urging the roller against the differential cam, the spring is used for the spring. There is a problem that the number of parts is increased and design restrictions are caused because the spring is arranged.

An object of the present invention is to obtain a lens barrel that solves the above problems.

[0011]

According to the present invention, a guide cylinder having a cam, a movable cylinder having a stepped front and rear slide removal cam formed by shifting the front and rear of the cam in radial positions, and a cam of the guide cylinder are provided. And a lens barrel that is moved by the cam of the movable barrel, a contact portion or a fitting portion of the guide barrel with respect to the cam, a contact portion that contacts a cam surface that serves as a reference of the stepped front / back slide removal cam of the movable barrel, and this contact A roller integrally attached to the cam surface for elastically urging the cam surface toward the cam surface, and a positioning pin for restricting a rotational angle position, and attached to the lens barrel via a roller shaft. And the rotation angle position is regulated by the positioning pin, the rotation angle position is regulated by the roller shaft, and the roller mounted on the lens barrel by the roller shaft is the cam of the guide tube. On the other hand, the contact portion or the fitting portion of the roller comes into contact, and the contact portion is urged by the elastic portion against the reference cam surface of the stepped front / rear slide removal cam of the moving cylinder, and the stepped front / rear slide extraction of the moving tube is pushed. The elastic portion of the roller absorbs the unstable portion of the cam width of the cam.

[0012]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a main part. In FIG. 1, 1
Is a guide tube having a taper cam 1a by radial die-cutting, which holds the moving tube 2 in a straight-line fit state and defines a moving position of a lens barrel 3 which holds one group forming a lens system, Reference numeral 2 is a movable barrel having a differential cam 2a for holding another lens group that constitutes the lens system and for holding and moving the lens barrel 3. This difference cam 2
Reference character a is a front and rear slide removal cam that is formed by a forming die in which the front and rear of the cam have different moving directions, and the cam width of this type of cam is relatively unstable.

The roller 4 is attached to the lens barrel 3 by a roller shaft 6 while being biased by a biasing spring 5 via a taper cam 1a of the guide barrel 1 and a differential cam 2a of the moving barrel 2. At the time of this attachment, as will be described later, the rotation stop pin 4a provided on the roller 4 is received by the rotation stop hole 3a provided on the lens barrel 3, and the rotation position of the roller 4 is fixed.

2 to 4 are detailed views of the roller 4, FIG. 2 is a plan view, FIG. 3 is a front view, and FIG. 4 is a longitudinal sectional view. In addition to the above rotation stopping pin 4a, a taper is provided. It has a taper portion 4d for coming into contact with the cam, a contact portion 4c for coming into contact with the reference surface of the differential cam due to front and rear slide removal, and an elastic portion 4b formed by cutting out a part in the rotational direction.

FIG. 5 is a vertical cross-sectional view showing a state in which the guide barrel 1, the moving barrel 2 and the lens barrel 3 shown in FIG. 1 are attached. In this attached state, the rotation is restricted by the position of the rotation stop pin 4a. As shown in FIG. 6, the elastic portion 4 of the roller 4 is formed on the sub surface 2b of the differential cam 2a formed by the front and rear slide removal cams of the cylinder 2.
b is always in contact, and the contact portion 4c contacts the reference surface 2c of the differential cam 2a.
Is being pressed and urged. Also, the taper cam 1 of the guide cylinder 1
The tapered portion (fitting portion) 4d of the roller 4 is in contact with a while being biased by the biasing spring 5.

Therefore, the smaller the displacement of the differential value of the differential cam 2a in contact is, the smaller the angular width of the elastic portion 4b of the roller 4 can be made. It should be noted that the cam barrel, rollers, etc. for moving the movable barrel 2 in a straight line are not directly related to the present invention, and therefore illustration and description thereof are omitted.

Since the first embodiment has the above-mentioned structure, when the cam barrel or the like (not shown) is actuated to move the movable barrel 2 in the optical axis direction, the differential cam 2a of the movable barrel 2 and the guide barrel 1 are moved. The lens barrel 3 moves while rotating along the intersection of the taper cams 1a.

In the first embodiment, the rotation stop pin 4a is provided on the roller 4 to regulate the rotation angle position of the roller 4, but the pin is provided on the lens barrel 3 side.
You may provide a pin fitting hole in. Example 2. FIG. 7 is a vertical sectional view showing the second embodiment. In the second embodiment, a cam 1a that is not a tapered cam is formed in the guide cylinder 1, and a fitting portion 4d that fits the cam 1a is formed in the roller 4. Other configurations and operations are the same as those in the first embodiment. Is. Therefore, as in the first embodiment, the biasing spring that biases the tapered portion 4d of the roller 4 on the tapered cam 1a of the guide barrel 1 is unnecessary, and in the second embodiment, the cam is cut like the metal lens barrel. It is effective for food.

[0019]

As described above, according to the present invention,
Since the elastic part and the positioning pin that regulates the rotational angle position are provided integrally with the roller, it is possible to realize a lens barrel with a cam structure that is similar to that of molded parts due to design restrictions with a high degree of freedom with a small number of parts. There is an effect.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a lens barrel according to a first embodiment of the present invention.

FIG. 2 is a plan view of a roller used in the first embodiment.

FIG. 3 is a front view of the roller.

FIG. 4 is a vertical sectional view of the roller.

FIG. 5 is a vertical cross-sectional view of the assembled lens barrel in the first embodiment of the present invention.

FIG. 6 is a rotation angle relationship diagram between a roller and a cam.

FIG. 7 is a vertical cross-sectional view of a lens barrel according to a second embodiment of the present invention.

FIG. 8 is a vertical cross-sectional view showing a conventional lens barrel.

FIG. 9 is a vertical cross-sectional view showing another conventional lens barrel.

[Explanation of symbols]

 1 guide cylinder 2 moving cylinder 3 lens barrel 4 roller 4a positioning pin 4b elastic part 4c contact part 4d taper part

Claims (1)

[Claims] 1. A guide cylinder having a cam, a movable cylinder having a stepped front and rear slide removal cam formed by shifting the radial positions of the front and rear of the cam, and a cam of the guide cylinder and a cam of the movable cylinder. A lens barrel and a contact portion or a fitting portion for the cam of the guide barrel, a contact portion for contacting a cam surface serving as a reference of the stepped front and rear slide removal cam of the movable barrel, and a cam for urging the contact portion to the cam surface. A lens having an elastic portion for urging the surface integrally, a positioning pin for regulating a rotational angle position, and a roller attached to the lens barrel via a roller shaft. Lens barrel.