JPS60216321A - Lens moving device - Google Patents

Abstract

PURPOSE:To improve assembly by using a plane cam mechanism which has a projection wall formed in three dimensions for lens movement. CONSTITUTION:This device has the 2nd lens holding frame 34 and the 3rd lens holding frame 35 which move in an optical-axis direction, pins 51 and 52 as the 1st engaging member provided on the 2nd lens holding frame 34, and pins 53 and 54 as the 2nd engaging member provided on the 3rd lens holding frame 35. Further, this is equipped with the 1st projection wall 39 which engages with the 2nd engaging member and is arranged at right angles to the optical-axis direction on a plane parallel to the optical axis and movable nearly at right angles to the optical-axis direction and the 2nd projection wall 40 which engages the 2nd engaging member and is arranged at right angles to the optical-axis direction on a plane parallel to the optical-axis and nearly at right angles to the optical-axis direction.

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.

Conventional Structure and Its Problems As a conventional zooming mechanism for a lens Im barrel, a cam barrel attached to a fixed barrel is generally used to move the lens. This will be explained with reference to FIG.

FIG. 1 is a partial sectional view of the main parts of a conventional zoom lens barrel, in which 1 is a fixed barrel, 2 is a focus ring,
A helicoid screw 2a provided on the focus ring 2 is screwed into a helicoid screw 1a provided on the fixed barrel 1,
By rotating within the optical axis, the focusing lens L1. L2
゜Extend L3 in the optical axis direction. 2nd lens 14°15,
L6 is inserted into the first lens holding frame 8, and the threaded part 9a of the presser foot 9 of the second lens L4 is screwed into the threaded part 8a of the first lens holding frame 8. 8
Fixed. The third lens L7 is inserted into the second lens holding frame 10, and is fixed by being pressed by the presser ring 11 of the third lens L7. The first and second lens holding frames 8.10 are fixed cylinders 1
The guide ball 6.7 is inserted into the guide ball 6.7 whose base end is supported by the guide ball 6.7. 5 is a first lens holding frame 8 and a second lens holding frame 1
It is a cam cylinder in which a first cam groove 14 and a second cam groove 15 for moving the 0 in the optical axis direction are provided inward in a direction intersecting the optical axis direction, and the tip of the guide ball 6.7 is fixed 11ii1.
The ball support plate 17 that supports the
The fJ is regulated at a ratio of 1 to 1.In the first cam groove 14 and the second cam groove 15, second lenses L 4 , L 5 , I-6 and the third lens L are provided.
In order to regulate the position of the lens 7 on the optical axis, cam lenses 12 and 13 of the first lens holding frame 8 and the second lens holding frame 10 are engaged. In addition, eleven pins 16 are provided on the J-shaped cylinder 5, and the pins 16 have a length in the circumferential direction perpendicular to the optical axis direction perforated in the fixed cylinder 1. ;It passes through 1s18 and protrudes outward from the fixed cylinder 1. Reference numeral 19 denotes a zoom ring into which a zoom gear 20 is fitted so as to be rotatable around the optical axis, and a pin 1G is engaged with a long groove 21 in the optical axis direction formed on the inner circumferential side.

33- That is, when the zoom ring 19 is rotated by the operating knob 22, the pin 16 engaged with the long groove 21 is driven and the cam cylinder 5 is rotated, so that the first lens holding frame 8 and the second lens holding frame 8 are rotated. A second lens L 4 is attached to the lens holding frame 10 .

L5. The positions of +6 and the third lens 1-7 are regulated by the first cam groove 14 and the second cam groove 15, and zooming is performed.

However, in the above configuration, the assembly is performed by supporting the first and second lens holding frames 8 and 9 on the fixed barrel 1 via the guide balls 6 and 7, and then inserting the cam cylinder 5 and supporting the balls. The cam cylinder 5 is held by a plate 17. Then, the first and second lens holding frames 8 and 9 are moved to predetermined positions, and the cam followers 12 and 13 are attached to the first and second lens holding frames 12 and 13 through through holes (not shown) that are appropriately installed in the fixed barrel 1. This requires a procedure of attaching it to the lens holding frames 8 and 9 of No. 2, which poses a problem in that assembly requires skill.

Purpose of the Invention The present invention introduces a planar cam mechanism having a three-dimensionally formed convex wall to move the lens, and -4- provides a small and inexpensive lens movement that dramatically improves ease of assembly. ll
J device C! The purpose is to provide the following.

Structure of the Invention In order to achieve the first object, the lens moving device of the present invention includes a first lens holding frame d3 J, which is movable in the optical axis direction.
and the second lens holding frame, and the first lens holding frame”-
a first engaging member provided on the second lens holding frame; and a plane that engages with the first engaging member and is parallel to the optical axis. a first convex wall disposed in a direction intersecting the optical axis direction and movable in a direction perpendicular to the optical axis direction, and engaged with the second engaging member, and and a second convex wall arranged in a direction intersecting the optical axis direction on a plane parallel to the optical axis and movable in a direction substantially perpendicular to the optical axis direction. This makes it possible to obtain a compact and inexpensive lens moving device that dramatically improves ease of assembly.

Description of examples An embodiment of the present invention will be described below with reference to the drawings. I will explain.

FIG. 2 is a perspective view of a main part of a lens moving device according to an embodiment of the present invention, and FIG. 3 is a plan view of the main part.

The lens substrate 31 includes the third lens group Δ, the second lens group B1, and the third lens group Δ.
These are members for attaching the fixed lens D of the lens group C1, the diaphragm 32 of the master lens group E1, and the filter 30, respectively. Further, the lens substrate 31 has a guide member 31a.
, 31b, 31c and a protrusion 31d are formed.

The second lens holding frame 10 holds the lens group A, the second lens holding frame 34 holds the second lens group B, and the third lens holding frame 35 holds the third lens group C. The second lens holding frame 34 is inserted into the guide ball 36 supported by the lens substrate 31 through the hole 34a, and the guide ball 37 supported by the lens substrate 31 has a rotation prevention notch.
(not shown) by engaging the lens substrate 3
1 so as to be movable in the optical axis direction 50.

Similarly, the third lens holding frame 35 is also inserted into the guide ball 37 through the hole 35a, and is engaged with the guide ball 36 through the rotation prevention notch 35b. 38 is a cam plate, and a first convex wall 39 and a second convex wall 40 are formed.First convex wall: )
The second lens holding frame 34 is provided on both walls of 9.
1 and 52 are in contact with each other, and bins 53 and 54 provided in the third lens holding frame 35 are in contact with both walls of the second convex wall 40, respectively. 3
Guide members 31a, 31b, 31c provided in 1
It is supported movably in the direction of arrow 49 by.

Here, the convex wall will be briefly explained. Figure 4 shows a convex wall with 39 bins! It is a top view which shows i1.52. If the angle between the normal line of the contact point P between the bottle and the wall and the optical axis 50 is the pressure angle 0, and the bottle is vertical (Y is (j), then y is d/2COSθ. The thickness χ of the convex wall in the optical axis direction is expressed by the following formula: -C 1°χ - △ - 2y - △ - d / cos θ where △ is the center distance between the bins 51 and 52.

A recess 43 is formed on the lower surface of the plate 23, as indicated by a broken line in FIG. Furthermore, as shown in FIG. 5, which is a sectional view taken along line A-Δ in FIG. The protrusion 31d and the stop member 44 are fixed to the four parts 4 of the cam plate 38 after assembly.
It will be located within 3.

The zoom motor 46 is supported by the lens substrate 31,
A motor pinion 47 press-fitted into the motor shaft 71 (not shown) meshes with a rack 48 formed on the cam plate 38.

The operation of the lens moving device of this embodiment configured as described above will be explained below. FIGS. 6 and 7 are plan views of essential parts for explaining the operation.

In FIG. 6, a second lens holding frame 34 and a third lens holding frame 35 are supported on the lens substrate 31 so as to be movable in the optical axis direction 50 by guide balls (not shown). The procedure for viewing 8i is as follows. First, the bins 51 and 52 provided on the second lens holding frame 34 and the bins 53 and 54 provided on the third lens holding frame 35 are attached to the cam plate 3.
8 to a position where it engages with the first convex wall 39 and the second convex wall 40, respectively. Next, the cam plate 38 is inserted in the direction of arrow -8- 49 while aligning with the guide members 31a, 31b, and 31c. At this time, the protrusion 31d formed on the lens substrate 31 and the stop member 44 fit into the four parts 43 of the cam plate 38. The first convex wall 39 then engages with the bins 51, 52 of the second lens holding frame 34, and the second
The convex wall 40 of the third lens holding frame 35
engage with. Further, the flexible stop member 44 is connected to the recess 43
When the cam plate 38 is inserted to the position shown in FIG. 7 where the wall 43a disappears, the stop member 44 returns to the position where it is not pressed. In this state, the cam plate 38 is connected to the tip 44a of the stop member 44 and the wall 43b formed in the recess 43 of the cam plate 38, as shown in FIG.
Ml 4 formed on the protrusion 31d of the lens substrate 31 and the four parts 43 of the cam plate 38, not shown in FIG.
3c is movably supported up to the abutting position. Next, the zoom motor 46 supporting the motor binion 47 is attached to the lens substrate 31, and the motor binion 47 and the rack 48 formed on the cam plate 46 are engaged with each other. As a result, the rotational output of the zoom motor 46 is transmitted to the cam plate 38, the cam plate 3B moves in the direction of the arrow 49, and the second lens holding frame 34 and the third lens holding frame 35 move in the optical axis direction 50. Drive 1h
will be done.

As described above, according to this embodiment, by forming the convex wall on the plane -1-, it is possible to realize a lens moving device that is easy to assemble. In addition, the convex wall can be easily molded with high precision, and it is lighter and more compact than the conventional cam tube attached to a fixed barrel that moves the lens. , it is possible to realize a cheap + i lens movement am. In the above embodiments, the stop member is provided on the lens substrate, but the stop member may be provided on the cam plate.

Effects of the Invention As is clear from the following explanation, according to the present invention, assembly which conventionally required skill can be carried out very easily, and the members forming the convex wall can be assembled with high precision. Because it can be molded in a variety of ways, it has high productivity and is lighter in weight compared to the conventional cam tube attached to a fixed barrel that moves the lens. The effect of realizing a lens moving device is obtained.

-10-

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side sectional view showing a conventional zoom lens barrel, FIG. 2 is a perspective view of a main part of a zoom lens barrel according to an embodiment of the present invention, and FIG. 3 is a plan view of the main part. , Fig. 4 is an enlarged plan view of the same part, Fig. 5 is a sectional view taken along line A-△ of Fig. 3, and Fig. 6
7 are plan views of essential parts for explaining the operation. 31... Lens substrate, 33, 34. 35... 1st ~
Third lens holding frame, 36.37... guide pole,
38... Cam plate, 39. 40... First and second convex walls, 43... Recessed portion, 44... Stopping member, 46...
Zoom lens, 47...Motor pinion, 51-54
...Bin (engaging member) Agent Yoshihiro Morimoto 11-

Claims (1)

[Scope of Claims] 1. A first lens holding frame and a second lens holding frame movable in the optical axis direction, a first engaging member provided on the first lens holding frame, and the A second engaging member provided on a second lens holding frame engages with the first engaging member and is disposed on a plane parallel to the optical axis in a direction intersecting the optical axis direction. a first convex wall movable in a direction substantially perpendicular to the optical axis direction; and a first convex wall that engages with the second engagement member and moves in a direction intersecting the optical axis direction on a plane parallel to the optical axis. A lens moving device comprising a second convex wall that is disposed and movable in a direction substantially perpendicular to the optical axis direction. 2. The lens moving device according to claim 1, wherein the first convex wall and the second convex wall are formed on the same member. -1-