JPH04136805A - Optical equipment with lens shifter - Google Patents

Abstract

PURPOSE:To effectively prevent a ghost and a flare from generation owing to reflected light from guide bars by easily constituting two guide bars and fitting parts fitted axially to the guide bars in proper shape. CONSTITUTION:The guide bars 3 and 4 are fitted in the groove parts 1c and 2c of the fitting parts 1b and 2b of lens holding frames 1a and 1b from inside and outside. A lubricant such as grease is applied to the groove parts 1c and 2c of the fitting parts 1b and 2b and the lens holding frames are smoothly moved. The lens holding frame 1a and 2a have the fitting parts 1b and 2b slid on the guide bars 3 and 4 to move, and consequently while moving lens groups 1 and 2 are held at right angles to the optical axis and prevented from vibrating, the lens groups are moved in the direction of the optical axis so that the optical axes are aligned with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an optical device having a lens moving device, and in particular to moving a plurality of lens holding frames along the optical axis with high precision using two guide bars. The present invention relates to an optical device having a lens moving device suitable for a lens barrel such as a zoom lens.

(Prior Art) Conventionally, there has been a lens moving device configured to move a lens holding frame held in a lens barrel along the optical axis of an imaging system using a guide bar for zooming and focusing. Various proposals have been made.

For example, in a zoom lens, two lens groups, a variator lens group for zooming and a convencator lens group for correcting the image plane that changes due to zooming, are moved on the optical axis while maintaining a predetermined relationship. There is. At this time, many lens moving devices use a total of three guide bars.

FIGS. 3(A) and 3(B) are schematic diagrams showing the main parts of a lens moving device for moving a lens holding frame using a guide bar in a conventional zoom lens, respectively, showing the inside of a cross section perpendicular to the optical axis of the photographic lens. be.

In FIG. 3A, a lens holding frame 37a holding a variator lens group 37 is moved nine degrees using a guide bar 33 whose axis is passed through a hole 37b provided in a part of the lens holding frame 37a. In the same figure (B), the lens holding frame 38a holding the convencator lens group 38 is moved by 11qh] using a guide bar 34 whose shaft is passed through a hole 38b provided in a part of the lens holding frame 38a.

In the same figure (A), the guide bar 34 is not acting at all,
Similarly, in the same figure (B), the guide bar 33 is not acting at all. In the conventional lens moving device, by fitting the guide bar into the hole of the lens holding frame, a degree of freedom in the optical axis direction is provided while maintaining a posture perpendicular to the optical axis.

In addition, a U provided in a part of the lens holding frame 37a (38a)
A guide bar 36 is passed through the groove (guide groove) to prevent the lens holding frame from wobbling and to prevent the movement trajectory of the lens holding frame from deviating from the optical axis.

Lens holding frames 37a and 38 are attached using conventional guide bars.
In the method of moving the lens holding frame 37a,
Hole 37 provided to allow the shaft of Chi 1 to bar to pass through 38a
The lengths of b and 38b are made as long as possible in the optical axis direction in order to reduce the inclination of the lens holding frame with respect to the optical axis.

Further, the movable lens holding frames are moved along independently provided guide bars to move the optical axis. In addition, the U-groove provided in the lens holding frame is configured such that a common side hole 36 passes therethrough in order to align the centers of the optical axes of the respective lens holding frames.

FIG. 4 is a schematic view of the main part when a convex portion 42 is provided on a part of the lens holding frame 41 instead of the U groove provided in the lens holding frame shown in FIG.

In the figure, a guide groove 44 is provided in a fixed lens barrel 43 that is part of the lens barrel, and a convex portion 42 of a lens holding frame 41 is fitted into the guide groove. Then, the lens holding frame 4 is moved along the optical axis along the kite groove 44.

(Problem to be Solved by the Invention) The lens moving device shown in FIGS. 3 and 4 has a plurality of The guide bar for moving the lens holding frame in the optical axis direction and the guide bar for regulating the center of the optical axis of the lens holding frame are parallel to the optical axis and approximately symmetrical in the vertical direction with respect to the camera. It is placed in a certain position.

As described above, the lens barrel of many cameras has a plurality of guide bars arranged symmetrically with respect to the lens optical axis in the vertical direction of the camera. For this reason, (a) In general photography, the light source (sun, illumination lamp, etc.) is often located laterally from the L side of the photographic lens, and for this reason, the light that enters the photographic lens is It is reflected from the guide bar or kite f+ (U groove) placed below, reaches the imaging plane, and becomes Gose 1~ and flare.

(b) Methods of applying light shielding members or flocking on those surfaces to prevent reflections from guide bars or kite grooves, etc. cannot completely eliminate reflections, and also increase the number of work steps and complicate the structure. It's starting to change.

There were problems such as.

The present invention eliminates the use of the U-groove or convex portion provided in the conventional lens holding frame by appropriately configuring two guide bars and a fitting portion provided on the lens holding frame that allows the shaft to pass through the guide bar. Another object of the present invention is to provide an optical device having a lens moving device with a simple structure, which prevents the occurrence of ghosts and flares, and allows multiple lens holding frames to be easily moved along the optical axis with good alignment. do.

(Means for Solving the Problems) When an optical device having a lens moving device of the present invention moves a plurality of lens holding frames on the optical axis using a guide bar, it is possible to move the lens holding frames in one direction with respect to the lens holding frames. Two guide bars are arranged parallel to the optical axis on the side, and fitting portions provided on a part of the plurality of lens holding frames are fitted into the two guide bars, and at least a portion of the fitting portion is fitted into the two guide bars. are arranged in a staggered manner so that they can overlap each other in the optical axis direction.

In addition, in the present invention, the two guide bars are fixed to a fixed barrel constituting a part of the lens barrel, and the fitting portion of the lens holding frame is provided with a spring means,
The guide bar is biased in the direction by the spring means.

(Embodiment) FIG. 1 is a perspective view of a main part of an optical device (representing a lens barrel in this embodiment) having a lens moving device according to a first embodiment of the present invention.

In the figure, reference numerals 3 and 4 denote guide bars, each of which has a circular cross-sectional shape, and is fixedly arranged in a fixed tube (not shown) of the lens barrel so as to be parallel to the optical axis S. . la
, 2a are lens holding frames. two guide bars 3
．． 4 are arranged so as to be located side by side in one direction of the lens holding frames 1a and 2a.

Reference numeral 1 denotes a first movable lens group, which is held by a lens holding frame 1a. Reference numeral 1b denotes a fitting portion, which is integrally formed in a part of the lens holding frame 1a. The fitting part 1b is provided with two fittings in a part of the lens holding frame 1a corresponding to the two guide bars 3 and 4.
There are one. The fitting part 1b consists of a circle whose cross-sectional shape is smaller than a semicircle (the angle looking into the center is smaller than 180 degrees. The same applies hereinafter), and the fitting part 1b has a semicylindrical shape as a whole, and
They are arranged parallel to the optical axis S direction. A groove 1c whose cross-sectional shape is a circle smaller than a semicircle is provided on the inside of the fitting part 1b so as to be parallel to the optical axis S, into which a part of the guide bar 3.4 is fitted from the outside.

2 is a second movable lens group, which is held by a lens holding frame 2a. 2b is a fitting portion, which is integrally formed in a part of the lens holding frame 2a. A fitting part 2b is provided on a part of the lens holding frame 2a corresponding to two guide bars 3.4.
There are one. The fitting part 2b has a cross-sectional shape or the fitting part 1b
Similarly, it is made up of circles smaller than a semicircle, and has a semicylindrical shape as a whole. Further, the two fitting portions 2b are integrally connected by a connecting plate 2d, and are arranged parallel to the optical axis S. A groove 2C whose cross-sectional shape is a circle smaller than a semicircle is provided on the inside of the fitting part 2b so as to be parallel to the optical axis S, into which a part of the guide bar 3.4 is fitted from the inside.

The guide bar 3.4 is the fitting part 1 of the lens holding frames 1a and lb.
It fits into the grooves 1c and 2c of b and 2b from the inside or outside. A lubricant such as grease is applied to the grooves lc and 2c of the fitting portions 1b and 2b to smoothly move the lens holding frame.

The lens holding frames 1a, 2a move as the fitting parts 1b, 2b slide on the guide bar 3.4, and as a result, the first.
While maintaining the second movable lens groups 1 and 2 perpendicular to the optical axis, the optical axis of each lens group is moved in the same direction while preventing shake and aligning the centers of the optical axes of each lens group.

Note that the fitting parts 1b and 2b are the first. Second moving lens group 1.2
is regulated by a cam groove formed in a cam cylinder (not shown) and can move in the optical axis direction. In other words, the shapes are such that they do not interfere with each other.

FIGS. 2(A) and 2(B) are schematic views of main parts in a cross section perpendicular to the optical axis of a second embodiment of the present invention. The same figure (A
) shows a cross section of the lens holding frame 1a of the first moving lens group 1, and (B) shows a cross section of the lens holding frame 2b of the second moving lens group 2.

In this embodiment, compared to the first embodiment shown in FIG.
The difference is that a spring means 5 is provided in a part of 2b, and other configurations are the same as in the first embodiment.

In this embodiment, guide bars 3 and 4 are provided at the fitting portions 1b and 2b, respectively.
By providing the spring means 5 for pressing the guide bar 3.4, looseness in the fitting between the fitting portions 1b, 2b and the guide bar 3.4 due to variations in processing accuracy is effectively eliminated.

In addition, in the embodiment described below, two guide bars are used to move two lens holding frames, but it is possible to move three or more lens holding frames through two guide bars to move the optical axis. It may be configured to be moved.

Furthermore, in the above-described embodiment, the indicator piece of the fitting part 1b formed upright from the lens holding frame 1a may be made elastic to bias the fitting part 1b toward the guide bar 3.4. .

Further, in each of the above-described embodiments, the fitting portion 1b.

It is also possible to form a structure in which a taper is applied to the overlapping ends of the parts 2b to prevent collisions between the ends when they overlap.

(Effects of the Invention) According to the present invention, the shapes of the two guide bars disposed in one direction with respect to the optical axis and the fitting portion provided on the lens holding frame through which the shafts pass through the guide bars are appropriately adjusted as described above. With this configuration, it is possible to achieve an optical device having a lens moving device that effectively prevents the occurrence of glare and flare based on the reflected light from the guide bar of the light flux incident from the photographing lens with a simple configuration. .

[Brief explanation of drawings]

FIG. 1 is a perspective view of the main parts of the first embodiment of the present invention, and FIG. 2 (A
), (B) are sectional views of the main parts perpendicular to the optical axis of the second embodiment of the present invention, and FIGS. 3 (8), (11), and 4 are the optical axis of the conventional lens moving device FIG. In the figure, 1 is a first moving lens group, 2 is a second moving lens group,
3 and 4 are guide bars, 5 is a spring means, la and 2a are lens holding frames, lb and 2b are fitting parts, lc and 2c are groove parts, 2d is a connecting plate, and S is a light 111. Patent applicant: Canon Co., Ltd.

Claims (3)

[Claims] (1) When moving multiple lens holding frames on the optical axis using a guide bar, two
The guide bars of the book are arranged parallel to the optical axis, and the fitting parts provided on a part of the plurality of lens holding frames fit into the two guide bars, and at least a part of the fitting parts is connected to the optical axis. 1. An optical device having a lens moving device, characterized in that the lens moving devices are arranged in a staggered manner so that they can overlap each other in the direction. (2) Claim 1, wherein the two guide bars are fixed to a fixed barrel that constitutes a part of the lens barrel.
An optical instrument having the lens moving device as described. (3) The lens moving device according to claim 2, wherein a spring means is provided at the fitting portion of the lens holding frame, and the spring means biases the guide bar in one direction. Optical equipment with.