JP2794923B2 - Optical equipment having a lens moving device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an optical apparatus having a lens moving device, and more particularly, to moving a plurality of lens holding frames on an optical axis with high accuracy using two guide bars. For example, the present invention relates to an optical apparatus having a lens moving device suitable for a lens barrel such as a zoom lens.

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

For example, in a zoom lens or the like, two lens groups, a variator lens group for zooming and a compensator lens group for correcting an image plane that fluctuates due to zooming, are moved on the optical axis while maintaining a predetermined relationship. . At this time, many lens moving devices use three guide bars as a whole.

FIGS. 3A and 3B are schematic views of a main part showing a cross section orthogonal to an optical axis of a photographing lens in a lens moving device for moving a lens holding frame using a guide bar in a conventional zoom lens. is there.

In FIG. 7A, a lens holding frame 37a for holding the variator lens group 37 is moved on the optical axis by using a guide bar 33 which is inserted through a hole 37b provided in a part thereof. Fig. (B)
Now, the lens holding frame that holds the compensator lens group 38
The guide bar 34 has a hole 38b provided in a part of the hole 38b.
Is moved on the optical axis by using

In the same figure (A), the guide bar 34 does not act at all,
Similarly, the guide bar 33 does not work at all in FIG. In the conventional lens moving device, by fitting the hole of the lens holding frame and the guide bar in this way, the degree of freedom in the optical axis direction is maintained while maintaining a posture perpendicular to the optical axis.

Further, the guide bar 36 is passed through a U-shaped groove (guide groove) provided in a part of the lens holding frame 37a (38a) to prevent the lens holding frame from oscillating, and the movement locus of the lens holding frame moves on the optical axis. Try not to deviate.

In the conventional method of moving the lens holding frames 37a and 38a by using the guide bar, the length of the holes 37b and 38b provided for allowing the guide bars to pass through the lens holding frames 37a and 38a is adjusted by the length of the lens holding frame. In order to reduce the inclination with respect to the optical axis, it is made as long as possible in the optical axis direction.

The moving lens holding frames are moved along the optical axis by sliding along independently provided guide bars. In addition, the U-shaped groove provided in the lens holding frame is configured so that a common guide bar 36 passes through the U-groove so as to match the optical axis center of the optical axis of each lens holding frame.

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

In the figure, a guide groove 44 is provided in a part of the fixed lens barrel 43 of the lens barrel, and the projection 42 of the lens holding frame 41 is fitted into the guide groove. Then, the lens holding frame 41 is
Along the optical axis.

FIG. 5 is a schematic view of a main part of a lens barrel proposed in Japanese Patent Application Laid-Open No. 63-95409. In the same figure, two guide poles 52, 54 and one guide member 50a are provided in the fixed lens barrel in parallel with the optical axis, and two lens holding frames 53, 55 are mounted on the two guide poles 52, 54. Mounted movably parallel to the axis.

A guide cylinder 58 provided on the lens holding frame 53 is fitted to the guide pole 52, and a guide cylinder provided on the lens holding frame 55.
59 is fitted to the guide pole 54.

Thereby, the lens holding frames 53 and 55 are moved in the optical axis direction.

(Problems to be Solved by the Invention) In the lens moving device shown in FIGS. 3 and 4, two guides for each lens holding frame are used to move the two lens holding frames 37a and 38a on the optical axis. Three guide bars, one guide bar 36 common to the bars 33 and 34, were used.

For this reason, the whole apparatus tends to be complicated. Also, in the lens barrel shown in FIG.
3 guide poles 5 overall to move 3,55
2,54,50a was used. For this reason, the whole apparatus tends to be complicated.

The lens barrel shown in FIG. 5 has two lens holding frames.
When 53 and 55 move on the optical axis and come close to each other, when the guide cylinder 58 and the guide cylinder 59 are partially viewed from a direction perpendicular to the optical axis,
Overlap.

However, the guide cylinder 58 provided on the lens holding frame 53 comes into contact with the lens holding frame 55 if it is brought too close, so that the lens holding frame 53 and the lens holding frame 55 cannot be brought too close.

For this reason, there is a problem that the method cannot be applied to an optical system that requires the two lens holding frames 53 and 55 to approach each other.

According to the present invention, by appropriately configuring the two guide bars and the fitting portion provided on the lens holding frame and axially communicating with the guide bar, compared with the case where the fitting portions are provided on separate guide bars, It is an object of the present invention to provide an optical apparatus having a lens moving device having a simple configuration capable of bringing a plurality of lens holding frames closer to each other.

(Means for Solving the Problems) When moving a plurality of lens holding frames on the optical axis using a guide bar, the optical apparatus having the lens moving device of the present invention moves the two guide bars to the optical axis. The fitting portions provided in a part of each of the plurality of lens holding frames are arranged in parallel, and the fitting portions are fitted to the two guide bars, and the plurality of fitting portions are attached to each other on the same guide bar. It is characterized by being staggered so that it can overlap.

In addition, in the present invention, the two guide bars are fixed to a fixed barrel that forms a part of the lens barrel, and a spring unit is provided at a fitting portion of the lens holding frame. The guide bar is urged in one direction by a spring means.

(Embodiment) FIG. 1 shows an optical apparatus having a lens moving device according to a first embodiment of the present invention (in this embodiment, a lens barrel is shown).
FIG.

In the figure, reference numerals 3 and 4 denote guide bars, each having a circular cross-section, and fixedly arranged on a fixed barrel (not shown) of the lens barrel so as to be parallel to the optical axis S. . 1a, 2
a is a lens holding frame. The two guide bars 3, 4 are arranged so as to be located side by side on one side of the lens holding frames 1a, 2a.

Reference numeral 1 denotes a first moving lens group, which is held by a lens holding frame 1a. Reference numeral 1b denotes a fitting portion, which is formed integrally with a part of the lens holding frame 1a. Fitting part 1b is lens holding frame 1a
Are provided corresponding to the two guide bars 3 and 4 in a part of. The fitting portion 1b is formed of a circle having a cross-sectional shape smaller than a semi-circle (an angle with respect to the center is smaller than 180 degrees, the same applies hereinafter), has a semi-cylindrical shape as a whole, and is arranged parallel to the optical axis S direction. ing. Guide bar inside fitting part 1b
A groove 1c formed by a circle having a cross-sectional shape smaller than a semicircle for fitting a part of 3, 4 from outside is provided in parallel with the optical axis S.

Reference numeral 2 denotes a second moving lens group, which is held by a lens holding frame 2a. Reference numeral 2b denotes a fitting portion, which is formed integrally with a part of the lens holding frame 2a. The fitting part 2b is the lens holding frame 2a
Are provided corresponding to the two guide bars 3 and 4 in a part of. The fitting section 2b has a cross section formed of a circle smaller than a semicircle like the fitting section 1b, and has a semi-cylindrical shape as a whole. The two fitting portions 2b are integrally connected by a connecting plate 2d, and are arranged in parallel with the optical axis S. Inside the fitting portion 2b, a groove portion 2c having a cross section formed of a circle smaller than a semicircle and being parallel to the optical axis S is provided for fitting a part of the guide bars 3 and 4 from the inside.

The guide bars 3, 4 are fitted into the grooves 1c, 2c of the fitting portions 1b, 2b of the lens holding frames 1a, 2a from inside or outside. Mating part 1b,
A lubricant such as grease is applied to the grooves 1c and 2c of the groove 2b to smoothly move the lens holding frame. The lens holding frames 1a, 2a move by the fitting portions 1b, 2b sliding on the guide bars 3, 4, thereby maintaining the first and second moving lens groups 1, 2 perpendicular to the optical axis. While moving, the movement in the optical axis direction is performed with the optical axis center of each lens group being aligned while preventing shake.

The fitting portions 1b and 2b are arranged in the optical axis direction so that the first and second movable lens groups 1 and 2 can be moved in the optical axis direction by being restricted by a cam groove or the like formed in a cam cylinder (not shown). It is configured to have a shape that can partially overlap each other (a circle smaller than a semicircle in this embodiment), that is, a shape that does not interfere with each other.

FIGS. 2A and 2B are schematic views of a main part in a cross section orthogonal to the optical axis of a second embodiment of the present invention. Figure (A)
FIG. 2B shows a cross section of the lens holding frame 1a of the first moving lens group 1, and FIG. 2B shows a cross section of the lens holding frame 2a of the second moving lens group 2.

In this embodiment, compared with the first embodiment shown in FIG.
The difference is that a spring means 5 is provided in a part of b.
Other configurations are the same as those of the first embodiment.

In this embodiment, the fitting parts 1b, 2b are provided with spring means 5 for pressing the guide bars 3, 4, respectively, so that the play of the fitting between the fitting parts 1b, 2b and the guide bars 3, 4 due to the variation in processing accuracy is reduced. Effective removal.

In the above embodiment, the case where two lens holding frames are moved using two guide bars has been described. However, three or more lens holding frames are moved through the two guide bars to be moved on the optical axis. It may be configured as follows.

Further, in the above-described embodiment, the pointing piece of the fitting portion 1b formed by being raised from the lens holding frame 1a has elasticity so as to have elasticity.
1b may be biased toward the guide bars 3 and 4.

Further, in each of the above-described embodiments, the overlapping ends of the fitting portions 1b and 2b may be tapered so as to prevent collision of the ends at the time of overlapping.

(Effects of the Invention) According to the present invention, the fitting portions provided separately on the two guide bars and the lens holding frame through the guide bars are appropriately configured as described above. More lens holding frames than when provided on the guide bar
An optical instrument having lens moving devices that can be brought closer together can be achieved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a first embodiment of the present invention, and FIGS. 2A and 2B are cross-sectional views of main parts of a plane perpendicular to the optical axis of a second embodiment of the present invention. 4A and 4B are cross-sectional views of a main part of a plane perpendicular to the optical axis of a conventional lens moving device. In the figure, 1 is a first moving lens group, 2 is a second moving lens group,
Reference numerals 3 and 4 denote guide bars, 5 denotes a spring means, 1a and 2a denote lens holding frames, 1b and 2b denote fitting portions, 1c and 2c denote grooves, 2d denotes a connecting plate, and S denotes an optical axis.

Claims (3)

(57) [Claims] When moving a plurality of lens holding frames on an optical axis using a guide bar, two guide bars are arranged in parallel with the optical axis, and a part of each of the plurality of lens holding frames is provided. A lens moving device, wherein the provided fitting portions are fitted into the two guide bars, and the plurality of fitting portions are arranged on the same guide bar so as to be shifted from each other so as to be able to overlap each other. An optical device having: 2. An optical apparatus having a lens moving device according to claim 1, wherein said two guide bars are fixed to a fixed barrel forming a part of a lens barrel. 3. A lens according to claim 2, wherein a spring means is provided at a fitting portion of said lens holding frame, and said guide bar is urged in one direction by said spring means. Optical equipment having a moving device.