JPS59176711A - Lens moving device - Google Patents

Abstract

PURPOSE:To position a lens with high precision by supporting a guide member which guides the lens by a member united with a base plate. CONSTITUTION:The 1st lens moving frame 27 which moves in optical-axis directions, the 2nd lens moving frame 28 which moves in the optical-axis directions, guide poles 46 and 47 which guide those 1st and 2nd lens moving frames 27 and 28, and the base plate 22 having a united support base 44 which position and hold the guide poles 46 and 47 are provided. Further, the 1st cam groove 25 for moving the 1st lens moving frame 27 in the optical-axis directions, the 2nd cam groove 26 which moves the 2nd lens moving frame 28 in the optical-axis directions, and a driving gear 33 which rotates in a plane parallel to the optical axis are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL APPLICATION The present invention relates to a lens moving device applied to video cameras and the like.

Conventional structure and its problems As a conventional zooming mechanism for a lens barrel, a cam barrel attached to a fixed barrel is generally used to move the lens. This will be explained based on FIG. 1st
The figure shows the main parts of a conventional zoom lens barrel, in which (1) is a fixed barrel, (2) is a focusing lens n Ll, L2 . Hold L8 t Lua t-force 7. ') holder, (3) Hallen's presser foot, and (4) are spacers. Attach the focus ring (2) to the helicoid screw (1a) provided on the fixed barrel (1).
) are engaged, and by rotating the focus ring (2) around the optical axis, the focusing lens groups Ll, L2 . L8 is moved in the optical axis direction. , variable magnification lens group L4. L5゜L6
is inserted into the first lens moving frame (8) and the lens presser (9) is inserted into the first lens moving frame (8).
) is fixed to the first lens moving frame (8) by screwing the threaded portion (9a) of the first lens moving frame (8) into the threaded portion (8a) of the first lens moving frame (8). The correction lens L7 is inserted into the second lens movement frame αQ, and the second lens movement frame is moved by inserting the holding ring 0]) into the sloped part (10a) provided on the inner periphery of the second lens movement frame 01. Fixed to 00.

(6a) to (6c) are guide poles, one end of which is fitted into a hole (1b) formed in the fixed tube (1), and the other end inserted into a hole (17a) formed in the pole support plate θ. It is supported by inset. The guide pole (6a) is the first
The guide pole (6b) is inserted into the hole (8c) provided in the second lens movement frame (8), and the guide pole (6b) is inserted into the second lens movement frame (10).
is inserted into the hole (tOC) provided in the guide pole (
6c) is engaged with the notch (8b) of the first lens moving frame (8) and the notch (10b) of the second lens moving frame θQ. By the way, the pole support plate 07) has a protruding protrusion (not shown) formed on the outer circumference, and this engages with a notch (not shown) formed in the fixed tube (1) to provide a guide. The holes (17a) supporting the poles (6a) to (6c) are aligned in phase.

tS is a holding ring that supports the pole support plate αη between the fixed positions (1). (5) is a first lens moving frame (8) and a second lens moving frame (10) for moving the first lens moving frame (10) in the optical axis direction.
It is a cam cylinder provided with a cam groove α→ and a second cam groove 0.

The first cam groove 04 has variable magnification lens group L4. L5. In order to regulate the position of L6 in the optical axis direction, the first lens moving frame (
8) is engaged with the first cam follower (6) implanted in the cam follower (6). Similarly, in the second cam groove OQ, a second lens moving frame 0 is provided in order to regulate the position of the correction lens L7 in the optical axis direction.
The second cam follower 〇 frame installed in Q is engaged. 0 barrel is a zoom ring with an operation knob (a),
A zoom ring 0 is rotatably fitted around the optical axis. Further, a long groove OI in the optical axis direction is formed on the inner peripheral surface of this zoom ring (to), and a pin 00 implanted in the cam cylinder (5) is engaged with this long groove (II). When the zoom ring 0 barrel is rotated around the optical axis, the bin 0 engaged with the long groove 0* is driven, and the cam cylinder (5) is rotated around the optical axis.Then, the first cam groove α4 The first cam follower (2) engaged with the second cam groove θG and the cam follower 〇G engaged with the second cam groove θG move along the respective cam grooves (140 o'clock) in the optical axis direction. Lens moving frame (8)
Zooming is performed by moving the second lens moving frame 01 in the optical axis direction. In this way, the first and second lens moving frames (8) are connected to the guide pole (6).
+ to the above conventional example supported by a) to (6c)
5, the influence of the positional accuracy of the guide pole on the lens performance is extremely large. Therefore, high precision machining is essential for positioning the guide pole. Furthermore, due to the groove structure in which the guide pole is fixed within the cylinder, one end of the guide pole must be fixed with a separate member, resulting in problems such as difficulty in achieving accuracy. Ta.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and an object thereof is to provide a lens moving device that is simple in structure and assembly and capable of moving a lens with high precision.

Structure of the Invention In order to achieve the above object, the lens moving device of the present invention has the following features:
A first lens moving frame that moves in the optical axis direction, a second lens moving frame that moves in the optical axis direction, a guide member that guides the first and second lens moving frames, and positioning the guide member. A substrate integrally formed with a support base,
A plane parallel to the optical axis and having a first cam part that moves the first lens moving frame in the optical axis direction and a second cam part that moves the second lens moving frame in the optical axis direction. It is equipped with a drive member that rotates within the drive member.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on the drawings. 2 to 5 show a first embodiment of the present invention. In FIG. 2, (a) indicates a focusing lens IA, a variable magnification lens group B, a correction lens C, a fixed lens moving frame, and a master lens group (not shown).

This is a lens substrate for performing a focusing operation, a zooming operation, and attaching the filter (2) to a fixed position, respectively. (The focusing lens group holding frame is fitted into the cylindrical side of the holding ring (G) that is integrally formed on the lens substrate (A).The end face of the focusing lens 7tl holding frame (B) The focusing lens group holding frame (B) is held by the holding ring (G) by pressing the end cam (not shown) formed in the connecting member (C) by the pressing spring part (aSa). The focusing lens group holding frame is rotated to be moved out in the direction of the optical axis.

2) is a guide pole, and both ends are elastically supported by a support stand (+4) integrally formed with the lens substrate.
It is formed integrally with the holder and is elastically supported by a support stand (not shown). The first lens moving frame (b) has its hole (27
a) by inserting the guide pole (JΦ) into the lens substrate and engaging the rotation prevention notch (not shown) in the guide pole 07, so that the lens substrate is movably supported on the slope of the lens substrate in the optical axis direction. There is. Similarly, in the lens moving frame (A) of @2, the guide pole θ is inserted into its hole (28a), and the rotation prevention notch (28b) is engaged with the guide pole (G). The first lens moving frame 1 is supported movably in the optical axis direction on the first cam groove 1) and the second cam groove for moving the first lens moving frame 1 in the optical axis direction.
It is a cam plate having a second cam groove (c) for moving the lens moving frame @ in the optical axis direction, and a shaft (not shown) embedded in the lens substrate (in the lens substrate) is parallel to the optical axis. The device is rotatable within a plane. 4 is a zoom motor, and the motor is attached to the plate (→, and the output of this zoom motor (A) is transferred from the motor gear Gυ fixed to the motor shaft (29a) to the idler gear), the crown gear (Fig. (not shown) to the drive gear (to), and further to the gear (c) formed on the outer periphery of the cam plate (c). As a result, the cam plate (e) is rotated, and the first lens moving frame (a) and the second lens moving frame (2) are moved in the optical axis direction. ) is a fixed lens frame. The operation of the lens moving device of this embodiment configured as above will be explained below. Fig. 8 shows the relationship between the cam plate, the first lens moving frame, and the second lens moving frame in wide zooming operation, and Fig. 4 shows the relationship between the cam plate, the first lens moving frame, and the second lens moving frame in telephoto zooming operation. 2 shows the relationship between the two lens movement frames. In FIG. 8, the first lens moving frame (A) has a guide ball θ supported by the lens substrate (A) inserted into its hole (27a), and a guide ball θ supported by the lens substrate (A). It is supported movably in the optical axis direction by engaging the rotation prevention notch with the lens. Similarly, the second lens moving frame (G) is also moved in the optical axis direction by inserting a guide pole θ into its hole (28a) and engaging the rotation prevention notch (28b) with the guide pole. Possibly supported.

In the first cam groove formed in the cam plate (2), there is a first cam follower 0 installed in the first lens movement frame.
]) is engaged. A second cam follower 0 stop installed in the second lens moving frame (to) is engaged with the cam groove (c) of the text box 2. In Fig. 8, when the output of the zoom motor is transmitted from the drive gear (to) to the cam plate,
The cam plate (■) rotates in the direction of the arrow about the rotation center (7). Then, it moves along the first cam follower=6υ and the second cam follower (ψ is in the first cam groove (c) and second cam groove, respectively) to the tele position shown in FIG. 4.

FIG. 5 shows a guide pole support (Q) formed integrally with the lens substrate (in FIG. 5, the guide pole) has a small diameter portion (46a) provided at both ends of the guide pole. (44aX44b) from above in the direction of an arrow θQ perpendicular to the longitudinal direction of the guide pole θQ, and is supported by the suppressing portions (44a) and (44b).

FIG. 6 shows another embodiment of the invention. In Fig. 6, the small diameter portions (46a) provided at both ends near the guide pole 0 are in contact with the positioning surfaces (44c) (44d) of the support base, and the plate springs are fixed to the support base with screws. It is fixed by the pressing force of 4.

Although FIGS. 5 and 6 show the part that supports the guide pole (2), the other guide ball (O) is also supported in the same way.

in the lens movement frame of text box 1) and the second lens movement frame (c)
It is obvious that in order to minimize the wobbling around the optical axis of the lens, it is necessary to provide a large distance between the hole for inserting the guide pole and the notch for preventing rotation.
For this purpose, it is also inevitable that it is most effective to support the two guide balls for insertion at positions 180 degrees apart from each other about the optical axis.

As described above, in the conventional machine f1 that moves the lens using a cam barrel attached to a fixed barrel, it is not possible to support the guide pole that guides the lens moving frame moving in the optical axis direction with an integral member. Although this was difficult, according to this embodiment, by introducing a planar cam mechanism to move the lens, it becomes possible to support the guide pole with an integral member.

Therefore, it becomes easy to accurately position the guide pole, and a lens moving device with high performance and ease of assembly can be provided.

Effects of the Invention As described above, according to the present invention, the guide member, which was supported by a separate member in the conventional configuration in which the lens is moved using a cam cylinder attached to a fixed cylinder, can be supported by a member integrated with the substrate. . Therefore, highly accurate positioning of the guide member can be easily achieved, and a lens moving device with high performance and ease of assembly can be provided.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway side view showing the main parts of the conventional example, Figures 2~
Fig. 5 shows the first embodiment of the present invention, Fig. 2 is a perspective view of the lens moving device, and Fig. 8 shows the cam plate and the first embodiment in wide mode.
FIG. 4 is a plan view showing the relationship between the cam plate and the first and second lens movement frames in telephoto mode, and FIG. FIG. 6 is a block diagram of a guide pole support section in another embodiment of the present invention. (Foundation)...Lens substrate, A...Focusing lens group, B...
...variable lens group, C...correction lens, D...fixed lens, tilting...cam plate, (c)...gear, ni)...
First cam groove, (7)...Second cam groove, Hole...First lens moving frame, (27a)...Hole, (27a)...Second lens moving frame, ( 28a)...hole, (28b)
...Notch, 6 parts...Zoom motor, (29a)...
・Motor shaft, Go...Motor gear, (2)...
Idler gear, (to)...Drive gear, [Yes]...Aperture, (To)...Filter, (To)...Retaining ring, (
B)...Focusing lens group holding frame, (7)...Connection member, (aSa)...Press spring part, @0g...Cam follower, ■...Support stand, (44a) ( 44b)...Pushing part, (44c) (44d)...Positioning surface, ■@
η... Guide pole, θ... Leaf spring agent Yoshihiro Morimoto Figure 3 Figure 4

Claims (1)

[Claims] 1. A first lens moving frame that moves in the optical axis direction, a second lens moving frame that moves in the optical axis direction, and the first and second lens moving frames that move in the optical axis direction.
a substrate integrally formed with a guide member for guiding the lens moving frame; a support base for positioning and supporting the guide member; a first cam portion for moving the first lens moving frame in the optical axis direction; A lens moving device comprising: a second cam portion that moves a second lens moving frame in the optical axis direction; and a drive member that rotates in a plane parallel to the optical axis. 2. The lens moving device according to claim 1, wherein the support base supports the guide member from a direction perpendicular to the longitudinal direction of the guide member. 8. The lens moving device according to claim 1, wherein the guide member includes two guide members, and the plane formed by the two guide members includes the optical axis.