JPS59192212A - Lens moving device - Google Patents

Abstract

PURPOSE:To simplify the assembling work by moving a lens moving frame, which is provided with a part to be driven which is brought into contact with and is engeged with a driving member, in the direction of the optical axis through the driving member which is rotated in a plane parallel with the optical axis. CONSTITUTION:Focusing, variable power, correcting, and fixed lens groups A, B, C, and D, a diaphragm 34, a master lens groups, and a filter 35 are attached to provide a lens substrate 22 for prescribed operations of focus operation and zoom operation. A focusing lens holding frame 38 is fitted to the inside cylinder side of a holding ring 39 formed in the lens substrate 22 as one body and is held freely turnably by a connecting member 41. End faces of the focusing lens holding frame 38 and the holding ring 39 which are slid on each other are provided with cams (which are not shown in Fig.) respectively, and the focusing lens holding frame 38 is turned to extend the focusing lens holding frame 38 in the direction of the optical axis.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field) The invention relates to a lens moving device for a video camera or the like.

(Conventional structure and its problems) The lens barrel is equipped with a mechanism to move the lens in the optical axis direction for focus operation, zoom operation, focus adjustment, etc., but the structure of the conventional lens barrel is ” 2. Japanese sentences are generally difficult to automate.

A typical conventional zooming mechanism for moving a lens using a cam barrel attached to a fixed barrel will be described below with reference to FIG.

FIG. 1 shows a cross section of the main parts of a conventional example of a zoom lens barrel, in which 1 is a fixed barrel, 2 is a focusing lens group Ll,
L2. This is a focus ring that holds L3. A helicoid screw 2a provided on the focus ring 2 is screwed into a recoid screw 1a provided on the fixed barrel 1, and when the focus ring 2 rotates around the optical axis, the focusing lens groups Ll, L2 and L3 are rotated. Move in the direction of the optical axis. Variable power lens group L4. L5°L6u, L4 It is fixed and attached to the first lens moving frame 8 by screwing the threaded portion 9a of the lens holder 9 into the threaded portion 8a of the first lens moving frame 8.

The correction lens group L7 is fixed and attached to the second lens movement frame 10 by fitting the L7 lens retaining ring 11 into a sloped portion 10a provided on the inner peripheral side of the second lens movement frame 10. 6a, (5b, 6c are guide balls which are supported by inserting one end of the PL into a hole 1b formed in the fixed tube 1 and the other end into a hole 17a formed in the pole support plate 17K. The guide ball 6a is the first
The guide pole 6b is inserted into the hole 10c provided in the second lens movement frame 1o, and the guide pole 6c is inserted into the hole 8cK provided in the first lens movement frame 8. Notch portion 8b and second lens moving frame 1
The pole support plate 17, which is engaged with the notch 10b of the fixed cylinder 1, has a convex portion (not shown) that protrudes on the outer circumference, and this is engaged with the notch 10b formed in the fixed tube 1. guide pole 6a+ by engaging with the guide pole 6a+ (not shown).
The holes 17a supporting 6b+6c are aligned in phase. The ball support plate 17 is fixed by a presser ring 16.

5 is a t-th lens moving frame 8 and a second lens moving frame 10
This is a cam cylinder provided with a first cam groove 14 and a second cam groove 15 for moving in the optical axis direction.

The first cam groove 14 includes a variable magnification lens fil L4. L
5. A first cam follower 12 implanted in the first lens moving frame 8 is engaged to regulate the position of L6 in the optical axis direction. Similarly, a cam follower 13 is engaged with the second cam groove 15K to regulate the position of the correction lens group L7 in the original axis direction. 18 is a zoom ring;
A zoom gear 21 is rotatably fitted into the main shaft opening. Furthermore, a cam cylinder 5 is provided in the long groove 19 formed in the inner peripheral bone.
A bottle 20 implanted in is engaged. Zoom ring 1
8 is rotated toward the optical axis opening, the pin 20 engaged with the long groove 19 is driven, and the cam cylinder 5 is rotated toward the original axis opening υ. And the first cam follower 1 engaged with the first cam groove 14
2 and the second cam follower 13 engaged with the second cam groove 15 move along the respective cam grooves 14 and 15 K in the optical axis direction. In this way, zooming is performed by moving the first lens moving frame 8 and the second lens moving frame 10 in the optical axis direction.

However, in the configuration in which the lens is moved using a cam barrel attached to a fixed barrel as described above, assembly is complicated due to its structure, and the assembly process cannot be easily automated. When the movable frame is inside the cylinder, assembly defects such as poor lens spacing, etc.
It was also difficult to directly confirm component accuracy defects.

(Objective of the Invention) The present invention introduces a planar cam mechanism that has a simple configuration and can move the lens with high precision, making assembly work as simple as a cylinder, and moreover, directly confirming poor component accuracy and assembly defects. (Structure of the Invention) In order to achieve the above object, the lens moving device of the present invention provides a lens moving device that can greatly automate the assembly process. a lens moving frame that is movable, a driving source, a driving member that is driven by the driving source and rotates in a plane parallel to the t-axis, and that is in a contact engagement relationship with the driving member and that moves the lens. It is provided on the frame and consists of a driven part 7c. This configuration simplifies the assembly work and makes it easy to check for poor component accuracy and assembly defects, making it possible to automate assembly processes that have been difficult to automate in the past.

(Explanation of Examples) Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 2 shows the structure of a lens barrel in one embodiment of the present invention. In FIG. 2, 22 includes a focusing lens group A1, a variable power lens group B1, a correction lens group C1, a fixed lens moving frame 934, a master lens group (not shown),
A lens substrate is used to remove the filter 35 and perform predetermined operations such as focus operation, zoom operation, etc. 38
is a focusing lens holding frame, which fits into the inner cylinder side of a holding ring 39 integrally formed on the lens substrate 22 and connects the connecting member 4.
It is rotatably held by 1. A cam (
(not shown) is formed, and by rotating the focusing lens holding frame 38, the focusing lens holding frame 38 is extended in the optical axis direction. The guide poles 36 and 37 are positioned and supported by the lens substrate 22. The first lens moving frame 27 is supported movably in the optical axis direction by inserting a guide pole 36 into the hole 27a and engaging a rotation prevention notch (not shown) in the guide ball 37. ing. Similarly, the second lens moving frame 28 also has a hole 2.
The guide ball 37 is inserted through 8a, and the guide ball 36
By engaging the notch 28b for preventing K rotation, it is supported movably in the direction of the original axis.

2:3, grooves 2 formed radially with respect to the rotation center for moving the first lens moving frame 27 in the optical axis direction
5 and a cam plate formed with a cam groove 26 for moving the second lens moving frame 28 in the optical axis direction, and is embedded in the lens substrate 22 and is rotatable about an axis (40 in FIG. 3). is installed on. Reference numeral 29 denotes a zoom motor, and the motor is attached to a plate 30.The output of the zoom motor 29 is driven from a motor gear 31 press-fitted into the motor shaft 29a, through an idle gear 32, and a crown gear (not shown). The signal is transmitted to the gear 33 and then to the cam plate 23 which has teeth 24 formed on its end surface. As a result, the cam plate 23 is rotated, and the first lens moving frame 27 and the second lens moving frame 28 are moved in the optical axis direction.

The operation of the lens moving device of this embodiment configured as described above will be explained in more detail below. FIG. 3 shows the cam plate 23 and the first cam plate at a wide angle during zooming operation.
FIG. 4 is a plan view showing the positional relationship between the lens moving frame 27 and the second lens moving frame 28, and shows the positions of the cam plate, the first lens moving frame, and the second lens moving frame during telephoto zooming operation. FIG. 3 is a plan view showing the relationship. In FIG. 3, the first lens moving frame 27 is moved in the optical axis direction by inserting a guide ball 36 into the hole 27a and engaging the guide pole 37 with a notch (not shown) for preventing rotation. movably supported. Similarly, the second lens moving frame 28
A guide ball 37 is inserted through the hole 28a, and is supported movably in the optical axis direction by a rotation-preventing notched portion (not shown) f: engaged with the guide pole 36.

A pin 42 implanted in the first lens moving frame 27 is engaged with a groove 25 formed radially with respect to the central rotation axis 40 of the cam plate 23 . Further, a cam follower 43 embedded in the second lens moving frame 28 is engaged with the cam groove 26 . In Fig. 3, the output of the zoom motor is the drive gear 3.
3 to the teeth 24 formed on the end surface of the cam plate 23, the cam plate 23 rotates about the shaft 40 in the direction of the arrow 44. Since the bin 42 engaged with the groove 25 and the cam follower 43 engaged with the cam groove 26 move in the optical axis direction, the first lens moving frame 27 and the second lens moving frame 28 move in the optical axis direction. The lens moves, thereby performing zooming, and moves to the telephoto position shown in FIG.

In the above embodiment, in order to move the lens moving frame in the optical axis direction, a groove and a cam groove are formed in the drive member, and a bottle and a cam follower are installed in the lens moving frame. Alternatively, a cam follower may be installed and a groove or cam groove may be formed in the lens movement frame.

(Effects of the Invention) As is clear from the above description, according to the present invention, a driven portion is provided which contacts and engages with a driving member that rotates in a plane parallel to the optical axis. Since the lens moving frame is moved in the optical axis direction, each component can be stacked and assembled, which simplifies assembly. It has the excellent effect of being able to directly measure the gap between groove lenses, making it easy to check for poor precision of parts and poor assembly.As a result, the assembly process can be made wider.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main parts of a conventional lens moving device, FIG. 2 is a perspective view of an embodiment of the present invention, and FIG. 3 is a wide-angle view of a cam plate, a first lens moving frame, and FIG. 4 is a plan view showing the positional relationship between the cam plate, the first lens moving frame, and the second lens moving frame in telephoto mode. 22... Lens board, 23...
Cam plate, 25... Groove, 26...
...Cam groove, 27...First lens moving frame, 28...Second lens moving frame, 29
...Zoom motor, 33...
, drive gear, 36.37... ・Guide pole, 42
...Hin, 43... Cam follower, A...
・Focusing lens group, B old... Variable magnification lens group, C
...-correction lens group. Figure 3 Figure 4 33 No. - No.

Claims (1)

[Claims] A lens moving frame movable in the light 1111+ direction, a driving source, a driving part driven by the driving source and rotating in a plane parallel to the optical axis, and in contact and engagement with the driving member. A lens moving device comprising: a driven section provided on the lens moving frame.