JPS62147414A - Lens mobile device - Google Patents

Abstract

PURPOSE:To obtain an inexpensive lens moving device by providing ring-shaped holding members which hold both ends of a driving member and a support means which supports the holding members or driving member rotatably around an optical axis. CONSTITUTION:The ring-shaped holding members 31 and 32 are molded out of resin at both ends of a cam cylinder 30 integrally by outsert molding. Those ring-shaped holding members 31 and 32 increase the rigidity of the cam cylinder 30 and also absorb variation in the curvature of the cam cylinder 30 during bending to suppress the slide resistance when mounted on a fixed barrel 1 to slide around the optical axis to a constant value. The cam cylinder is mounted rotatably around the optical axis while the the holding members 31 and 32 are mounted on the inner peripheral side of the fixed barrel. Therefore, when a zoom ring 18 is rotated, the cam cylinder 30 also rotates to move the 1st ring holding frame 8 and the 2nd lens holding frame 10 in the optical axis direction while their positions are controlled along the 1st cam groove 30a and the 2nd cam grove 30b, thereby performing zooming operation.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a lens moving device that is effective for use in video cameras and the like.

2. Description of the Related Art Conventional zooming mechanisms for lens barrels generally use a cam barrel attached to a fixed barrel to move the lens.

An example of the conventional lens moving device mentioned above will be described below with reference to the drawings.

FIG. 3 is a partial sectional view of the main parts of a conventional zoom lens barrel. Helicoid screw 1 provided in fixed barrel 1
．． The helicoid screw 21 provided on the focusing ring 2 is screwed together and rotated around the optical axis, thereby tightening the focusing lens L.
L, L2. Extend L3 in the optical axis direction. Focusing lens Ll
, L2. L3 is pressed and fixed by a lens holder 3 and a spacer 4. Variable power lens group L4. L5. L6 is inserted into the first lens holding frame 8 and is attached to the threaded portion 9 of the holding ring 9 of the variable magnification lens L4. the threaded portion 8. of the first lens holding frame 8.
It is fixed to the first lens holding frame 8 by being screwed into the first lens holding frame 8. The correction lens L7 is inserted into the second lens holding frame 10 and fixed by the pressing force of the presser spring 11. The first lens holding frame 8 is supported movably in the optical axis direction by having a guide pole 6 inserted into an elongated portion 8b and engaging a guide ball 6c in a cutout portion 8c. Similarly, the second lens holding frame 10 also has a guide pole 6 in the elongated hole portion 101.
, is inserted, and the notch 10. The guide ball 6c is engaged with the guide ball 6c to be supported movably in the optical axis direction. The cam frame 5 has a first cam groove 14 for driving the first lens holding frame 8 and the second lens holding frame 10 in the optical axis direction.
A second cam groove 15 is provided. The first cam groove 14 and the second cam groove 15 each include a variable magnification lens group L4. L
5. In order to regulate the positions of the lens L6 and the correction lens L7 on the optical axis, bins 12 and 13 implanted in the first lens holding frame 8 and the second lens holding frame 10, respectively, are engaged and the cams are engaged. A bottle 16 is installed in the tube 5, and the elongated hole 1
7 and protrudes to the outside of the fixed cylinder 1. legitimate child 20
In the zoom ring 18, a zoom gear 21 is fitted to be rotatable around the optical axis, and a pin 16 is engaged with a long groove 19 formed on the inner circumferential side. That is, when the zoom ring 18 is rotated, the pin 16 engaged with the long groove 19 is driven, and the cam barrel 5 is rotated, so that changes in the first lens holding frame 8 and the second lens holding frame 10 are caused. Double lens group L4. L5. Zooming is performed by regulating the positions of lens L6 and correction lens L7 by first cam groove 14 and second cam groove 15. As mentioned above, the cam barrel is one of the important parts that regulates the position of each movable lens, which requires high positional accuracy, so up until now, high-precision machining has been performed using lathes, milling, and other machining methods. .

However, the above-mentioned machined cam cylinder has a disadvantage in that the machining cost associated with high-precision machining is high. Further, in a cam cylinder formed by a cam groove obtained by penetrating the inside of the cylinder, it is impossible to eliminate deformation and distortion of the cylinder due to cam groove machining. Furthermore, even if attempts were made to make the cam cylinder thinner in order to reduce weight, there was a certain limit due to the deformation and distortion of the cylinder caused by the above-mentioned processing.

Problems to be Solved by the Invention In view of the above-mentioned problems, the present invention replaces the cam cylinder, which has conventionally been processed using expensive methods such as lathe processing and milling, with a thin plate member having cam grooves formed thereon. By comprising a holding member for holding the lens, an inexpensive lens moving device is provided.

Means for Solving the Problems In order to solve the above problems, the lens moving device of the present invention includes a first lens holding frame and a second lens holding frame that are movable in the optical axis direction, and a first lens holding frame and a second lens holding frame that can be moved in the optical axis direction. a flexible driving member formed with a first cam for driving the lens holding frame and a second cam for driving the second lens holding frame; a ring-shaped holding member that holds both ends of the driving member so as to be able to rotate;
A support means for rotatably supporting the holding member or the driving member about the optical axis.

According to the above-described configuration, the cam barrel for moving the lens and positioning it at a predetermined position is made up of a thin-walled member in which the cam 7 grooves are formed and a holding member that holds the cam barrel. Processing costs can be significantly reduced, resulting in an inexpensive and lightweight lens moving device.

EXAMPLE Hereinafter, a lens moving device according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a cam cylinder according to an embodiment of the present invention, and FIG. 2 is a partially sectional perspective view showing the cam cylinder attached to a ring-shaped holding member. In FIG. 1, the cam cylinder 30 is a stainless steel plate, and a cam groove of 30 m is formed in a flat plate by pressing.

30k, a notch 30c was formed, and then rolled up by roll forming. As shown in FIG. 2, ring-shaped holding members 31 and 32 made of a resin material are integrally formed at both ends of the cam cylinder 30 by outsert molding. These ring-shaped holding members 31 and 32 increase the rigidity of the cam cylinder 30, absorb variations in curvature during bending of the cam cylinder 30, and
It has the function of keeping the sliding resistance constant when it is attached to the optical axis and slides around the optical axis. This holding member 31.32
is supported on the inner peripheral side of the fixed barrel 1 shown in FIG. 3, so that the cam cylinder 30 is rotatably mounted around the optical axis. Cam groove 30 formed in the cam cylinder 30. ,3
The pin 12 of the first lens holding frame 8 and the pin 13 of the second lens holding frame 10 are respectively engaged with 0b. A pin (not shown) is implanted in the zoom ring 18 having the eldest child 20, which passes through an elongated hole 17 provided in the fixed barrel 1 and engages with a notch 30c of the cam cylinder 30. That is, when the zoom ring 18 is rotated, a pin (not shown)
Since the cam cylinder 30 is rotated, the positions of the first lens holding frame 8 and the second lens holding frame 10 are aligned with the first cam groove 3.
0. Zooming is performed by moving in the optical axis direction while being regulated along the second cam groove 30k.

As described above, according to this embodiment, the cam cylinder, which was conventionally made by machining, is constructed from a flexible thin-walled member in which a cam groove is formed and a holding member that holds this, thereby reducing the processing cost of the cam cylinder. can be significantly reduced.

In this embodiment, zooming was performed by driving the cam cylinder, but it is also possible to perform zooming by driving the holding member.

Further, in this embodiment, the holding members are integrated at both ends of the cam cylinder by outsert molding, but they may be integrated by a method such as adhesion or welding.

Furthermore, although the cam cylinder has been described with a shape in which the end portions in the bending direction are not connected, a cam cylinder may be used in which the end portions are bent with adhesive or connected by welding to increase rigidity.

Moreover, although the material of the cam cylinder is described as a stainless steel plate, other steel plates having the required performance may be used.

Further, the cam groove formed in the cam cylinder is not limited to being formed by press working, but may be formed by etching, for example.

Effects of the Invention As described above, the present invention includes a first lens holding frame and a second lens holding frame that are movable in the optical axis direction, and a first cam for driving the first lens holding frame. a flexible driving member formed with a second cam for driving the second lens holding frame; and holding both ends of the driving member so as to rotate the first driving member around the optical axis. By providing a ring-shaped holding member and supporting means that rotatably supports the holding member or the driving member around the optical axis, it is possible to provide an inexpensive and lightweight lens moving device.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a perspective view showing a cam cylinder in an embodiment of the present invention, Fig. 2 is a partially sectional perspective view showing the cam cylinder attached to a holding member, and Fig. 3 1 is a partial cross-sectional view showing the main parts of a conventional lens moving device. 1...Fixed trunk, 6. ．． 6. ．． 6c...
Guide pole, 8...First lens holding frame, 1
0...Second lens holding frame, 301...
・First cam groove, 30t, ... second cam groove,
31.32... Holding member. Name of agent: Patent attorney Toshio Nakao (1 person) Figure 1

Claims (1)

[Claims] A first lens holding frame and a second lens holding frame movable in the optical axis direction, a first cam for driving the first lens holding frame, and a first cam for driving the second lens holding frame. a flexible driving member formed with a second cam; a ring-shaped holding member that holds both ends of the driving member so as to rotate the driving member around the optical axis; and the holding member , or supporting means for rotatably supporting the driving member around an optical axis.