JPS63149616A - Moving structure for lens of camera - Google Patents

Abstract

PURPOSE:To obtain a lens moving structure appropriate as a micro-zoom lens mechanism for a compact camera by arranging guide members for guiding the movement of a moveble lens on a circular arc-like space part formed between a movable lens with an approximately elliptic shape and a cam barrel. CONSTITUTION:A rear group lens holder 5 is stored in the cam barrel 3 with a circular section, and when the cam barrel 3 is rotated, lens holders 14a, 14b, i.e. rear group lenses 13a, 13b have the approximately elliptic shape whose upper and lower parts are lacked, the guide members 15a, 15b are arranged on the upper space part between the cam barrel 3 and the holders 14a, 14b and the guide member 16 is arranged on the lower space part. Thus, the guide members 15a, 15b, 16 can be arranged without inceasing the diameter of the cam barrel 3, i.e. the diameter of a mirror barrel and the compact lens moving structure can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a camera lens moving structure, and can be applied to an ultra-compact zoom lens mechanism of a compact camera.

[Description of Prior Art 1] When a compact camera is equipped with a zoom lens mechanism, unlike a single-lens reflex camera in which the lens barrel is detachable from the camera body,
In a compact camera, the camera body and lens barrel are integrated, and the lens barrel goes inside the camera body, so if the diameter of the lens barrel increases, the camera body will become larger. For compact cameras to which the zoom mechanism of a camera cannot be directly applied, it is desirable not to increase the diameter of the lens barrel even when a zoom lens mechanism is provided.

C Purpose of the invention] The present invention has been made based on the above viewpoint.

The purpose is to provide a camera lens moving structure suitable for application to a zoom mechanism of a compact camera.

[Means for Achieving the Object] The present invention includes a movable lens, a cam cylinder having a circular cross section that accommodates the movable lens and moves the movable lens in the optical axis direction by rotation about the optical axis, and a guide member for guiding the movement of the movable lens, the movable lens having a substantially oval shape, and the guide member being disposed in an arcuate space formed between the movable lens and the cam cylinder. The above objective is achieved by the lens moving structure of the camera. That is, by forming the movable lens into a substantially oval shape, the guide member can be arranged without increasing the diameter of the cam cylinder and therefore the diameter of the lens barrel.

[Embodiment of the Invention] Fig. 1 is an assembled perspective view showing an embodiment of the present invention, showing an ultra-compact zoom lens mechanism of a compact camera.

In the figure, 1 is a fixed barrel, 2 is a movable barrel, 3 is a cam barrel, and 4 is a fixed barrel.
5 is a front group lens unit, and 5 is a rear group lens unit.

The movable tube 2 has a front storage chamber 6 that stores the front group lens unit 4, a rear storage chamber 7 that stores the cam tube 3, and guide bars 8a and 8b each having one end fixed to the movable tube 2. We are prepared. The front group lens unit 4 includes a front group lens 9a,
9b, and a holding member 10 that holds the front group lenses 9a and 9b.
and has.

The holding member 10 is attached to a protrusion 11a formed in the front storage chamber 6,
By engaging with itb, it is fixedly held in the front storage chamber 6 of the movable cylinder 2. A shutter member 12 is disposed between the front group lenses 9a and 9b.

The rear group lens unit 5 is housed in a cam cylinder 3 having a circular cross section. The rear group lens unit 5 includes a movable rear group lens 1.
3a, 13b, and a lens holder 14a that holds the rear group lenses 13a, 13b.

14b, guide members 15a, 15b that guide the movement of the rear group lenses 13a, 13b, and rear group lenses 13a, 1.
3b and a guide member 16 for preventing rotation of these lenses. In a compact camera, this is the rear group lens 13a.

13b has a larger diameter than the front group lenses 9a and 9b,
In particular, the diameter of the rear rear group lens 13b becomes large. Therefore,
When the rear group lens 13b is formed of a normal circular lens, the rear group lenses 13a, 13b and the guide members 15a, 15
It became necessary to increase the diameter of the cam cylinder 3 that accommodates b and 16,
In the present invention, taking into account that the screen size is 24 x 36 mm, the rear lens group 13a
, 13b have a substantially oval shape with the circular upper and lower parts missing to correspond to the screen size, and similarly the lens holder 1
4a and 14b are also approximately oval in shape. This provides an arcuate space at the upper and lower portions between the cam cylinder 3 and the lens holders 14a, 14b. Guide member 15
a.

15b is arranged in the upper space, and the guide member 16 is arranged in the lower space. Therefore, there is no need to increase the diameter of the cam cylinder 3, and the rear group lenses 13a and 13b are
Lens holders 14a, respectively.

Guide members 15a, 15b via 14b.

16 so as to be slidable. guide member 15a,
15b, 16c7) One end is connected to the holding plate 17, and the other end thereof is engaged with, for example, a recess (not shown) in the rear storage chamber 7 of the movable cylinder 2. The lens holders 14a and 14b are the cams vItl 8 a of the cam cylinder 3.

The cam cylinder 3 has pins 19a and 19b that engage with the cam cylinder 18b.
With this rotation, the lens holders 14a, 14b, that is, the rear group lenses 13a, 13b move along the guide members 15a, 15b, 16.

The cam barrel 3 is easily rotatably accommodated in the rear housing chamber 7 of the movable barrel 2 with the rear group lens unit 5 housed therein, and is held by a presser plate 17 coupled to the open surface of the rear housing chamber 7. The cam cylinder 3 has a pin 22 that engages with a cam groove 21 formed in a cam member 20 fixed to the lower surface of the fixed cylinder 1, and when the movable cylinder 2 is associated with the fixed cylinder l, the pin 22 is moving cylinder 2
It is configured to engage with the cam groove 21 through an open portion on the lower surface (not shown), and to be rotated by movement in the optical axis direction due to this engagement.

Front lens unit 4. The movable barrel 2 in which the cam barrel 3 and the rear group lens unit 5 are housed is guided into a guide hole (not shown) in the fixed barrel l.

8b, and the through end of the guide bar is connected to the stopper 23a,
By fixing it to the movable cylinder 2 at 23b, it is held movable forward and backward relative to the fixed cylinder l by sliding between the guide bars 8a, 8b and the guide hole of the fixed cylinder 1.

2(A) and 2(B) are explanatory diagrams of movement of the front group lens and rear group lens in the configuration shown in FIG. Figure (B) shows a state in which the movable cylinder is moved forward. The operation of the configuration shown in FIG. 1 will be explained below using FIGS. 2(A) and 2(B).

The movable barrel 2 is advanced to move the front group lenses 9a and 9b by L1. The rear group lens 13a is required for the amount of movement Ll of the front group lenses 9a and 9b.

The amount of movement of 13b is L2, L! is larger than

The rear group lenses 13a and 13b move forward by L1 due to the advancement of the movable barrel 2, and at the same time, the movement amount L is increased by the rotation of the cam barrel 3.
It moves forward by the difference ΔL between l and L2. That is, as the movable barrel 2 moves forward, the cam barrel 3 moves into the cam groove 21 of the fixed barrel l.
The rear group lenses 13a and 13b are rotated by engagement with the pin 22 of the cam cylinder 3, and this rotation causes the rear group lenses 13a and 13b to engage with the pins 19a and 19b.
The engagement between the cam grooves 18a and 18b further increases ΔL.
will only move forward. As a result, the rear group lens 13a
, 13b are given a desired movement amount L2.

In the embodiment described above, the rear group lens 13a.

Both lenses 13b are approximately oval in shape; however, in a compact camera, the rear group lens 13b in particular has a larger diameter, so only this rear group lens 13b may be made in an oval shape. A shaped lens can be easily formed from a plastic lens.

[Effects of the Invention] As explained above, according to the present invention, the movable lens moved by the cam barrel has a substantially oval shape, so that the arcuate space formed between the movable lens and the cam barrel is Since the configuration is such that a guide member is disposed to guide the movement of the movable lens, the guide member can be disposed without increasing the diameter of the cam barrel and therefore the diameter of the lens barrel. It is possible to provide a lens moving structure for a camera suitable for this purpose.

[Brief explanation of the drawing]

Fig. 1 is an assembled perspective view showing one embodiment of the present invention, and Fig. 2 (
A) and FIG. 2(B) are explanatory diagrams of movement of the front group lens and rear group lens in the configuration of FIG. 1. 3...Cam tube 13a, 13b...Rear group lens 1
4a, 14b...-Lens holder 15a. 15b, 16... guide member

Claims (1)

[Claims] A movable lens, a cam cylinder having a circular cross section that houses the movable lens and moves the movable lens in the optical axis direction by rotation about the optical axis, and a guide member that guides the movement of the movable lens, A lens moving structure for a camera, wherein the movable lens has a substantially oval shape, and the guide member is disposed in an arc-shaped space formed between the movable lens and the cam barrel.