JPH0580243A - Optical equipment - Google Patents

Abstract

PURPOSE:To provide an optical equipment which can have specific optical characteristics and can greatly be improved in assembly efficiency by preventing a 1st and a 2nd moving lens barrels moved in the optical-axis direction by zooming operation from having play in a thrust direction. CONSTITUTION:Overlap parts where the 1st lens barrel 1 and 2nd lens barrel 4 overlap with each other are provided on the entire area of the zooming operation and an elastic member 11 is arranged between the overlapping parts. Further, the elastic member 11 generates the pressing force by specific elasticity between the 1st barrel 1 and 2nd lens barrel 4 and a flocking process which provides specific light shielding property is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device such as a zoom lens.

[0002]

2. Description of the Related Art Conventionally, in a two-group zoom lens barrel, an elastic member (spring spring) is inserted in the thrust direction of the front group and the rear group as described in JP-A-1-144006, and the front group and the rear group. It had a lens barrel structure in which it was in a taut state to remove thrust play.

[0003]

However, in the above-mentioned conventional example, it is not easy to set the number of springs in an optical system having a large lens diameter, the followability between the front group and the rear group is poor, and the inner surface reflection of the springs is caused. Problems arise.

Further, an optical system having a large amount of movement of the front group and a large lens diameter is not good in appearance. In addition, assembling workability is not good when the spring member is used as the elastic member.

As described above, the structure in which the thrust play, which causes the tilting of the optical systems of the front group and the rear group, is corrected by the spring spring has problems such as occurrence of internal reflection and deterioration of assembly efficiency.

The present invention is intended to solve the above problems, and it is possible to effectively prevent play in the thrust direction between the lens barrels in the entire zoom range and obtain a predetermined optical performance. Moreover, it is an object of the present invention to provide an optical device capable of significantly improving the assembly efficiency.

[0007]

SUMMARY OF THE INVENTION The present invention is an optical device having first and second movable lens barrels that are moved in the optical axis direction by a zoom operation, and the first lens is provided in the entire zoom operation. It is characterized in that an overlapping portion where the lens barrel and the second lens barrel overlap each other is provided, and an elastic member is disposed between the overlapping portions. Further, the elastic member is characterized in that a pressing force is generated by a predetermined elastic force between the first lens barrel and the second lens barrel, and a flocking process having a predetermined light blocking property is applied. It is what

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 are views for explaining a lens barrel which is an optical apparatus according to an embodiment of the present invention. FIG. 1 is a side sectional view of the lens barrel, and FIG. 2 is AA of FIG. FIG. 3 is a cross-sectional view, and FIG. 3 is a detailed view of a mounting portion of the elastic member of FIG.

In these figures, a is a front lens group, and b
Indicates a rear lens group, and 1 indicates a fixed lens barrel. The fixed barrel 1 is formed with a plurality of (three) linear guide grooves 1a, 1a, 1a for guiding the front lens group a and the rear lens group b in the optical axis direction during zoom movement. A front group moving ring 2 is provided on the inner peripheral side of the fixed lens barrel 1 so as to be movable in the optical axis direction, and the front group moving ring 2 has a plurality of rollers 3 inserted into the respective straight guide grooves 1a. 3, 3 are rotatably arranged. Further, the rear lens barrel 4 having the rear lens group b mounted on the inner circumference of the fixed lens barrel 1 can be inserted into the front lens group moving ring 2 with a part thereof overlapped, and is movable in the optical axis direction. The rear group lens barrel 4 is rotatably provided with a plurality of rollers 5, 5, 5 which are inserted into the above-described rectilinear guide grooves 1a. A cam ring 6 is provided on the outer circumference of the fixed barrel 1 so as to be rotatable in the radial direction of the optical axis concentric circle.
For guiding the rollers 3, 3, 3 of the front lens group moving ring 2 and the rollers 5, 5, 5 of the rear lens barrel 4 for zooming the front lens group a and the rear lens group b in the optical axis direction. A plurality of cam grooves are formed. Further, a helicoid screw portion 2a is formed on the front end side of the inner circumference of the front group moving ring 2 described above, and the front group lens barrel 7 having the front group lens a is attached to the helicoid screw portion 2a by helicoid coupling (screw coupling). ) Is rotatably provided. A focus ring 8 arranged so as to cover a part of the outer circumference of the cam ring 6 is integrally fixed to the front lens barrel 7, and a focus ring 8 is provided between the focus ring 8 and the front lens barrel 7. The ring 9 is attached. Further, a zoom ring 10 provided so as to cover the outer circumference of the focus ring 8 is integrally fixed to the cam ring 6, and is arranged so as to rotate together with the cam ring 6.

The inner peripheral surface (rear end inner peripheral surface) of the front group moving ring 2 on the rear lens barrel 4 side is, for example, an elastic member which is subjected to flocking treatment so as to obtain a light-shielding property and a predetermined frictional force. 11 (Temp, trade name, manufactured by Koyo Kogyo Co., Ltd.) is provided, and the elastic member 11 presses the front group moving ring 2 and the rear group lens barrel 4 with a predetermined elastic force in the entire zoom movement. It is in a charged state.

In the lens barrel constructed as described above, when the zoom ring 10 is rotated, the front group moving ring 2 and the rear group barrel 4 are connected to the cam ring 6 and the fixed barrel 1.
Each of the cam grooves and the linear guide groove are zoomed in the optical axis direction, and the focus ring 8 is rotated to cause the front lens barrel 7 to move in accordance with the screw pitch of the helicoid screw portion 2a of the front group moving ring 2. The focus is moved in the direction. By the way, in the wide state and the tele state shown in FIG.
The front group lens barrel 7 may tilt toward the front group lens a side around the rollers 3, 3, 3 of the front group moving ring 2 that are helicoidally coupled, and the rear group lens barrel 4 may roll. 5, 5,
The front lens group a side (or the opposite direction) centered on the 5th part
However, since the front lens barrel 7 and the rear lens barrel 4 are elastically slidably connected by the elastic member 11 described above, the front lens group a and the rear lens group b are the same. It becomes a tilt of the direction, and consideration of optical allowance can be facilitated.

Therefore, in this embodiment, it is possible to greatly reduce the amount of overlap of each part for compensating the tilt of each lens group in the lens barrel, and thereby to reduce the size and weight of the entire lens barrel. It can be effectively planned.

In the above-described embodiment, if the positions of the rollers 5, 5 and 5 of the rear lens barrel 4 are properly selected, that is, the front lens barrel 7 is tilted in the direction in which the tilt is canceled. In this case, the amount of occurrence of falling can be significantly reduced in cooperation with the elastic effect of the elastic member 11.

In the above embodiment, the lens barrel is a lens barrel for a projector, a lens barrel for photographing, or
It can be applied to interchangeable lenses and lenses with built-in optical equipment.

[0016]

As described above, the optical device of the present invention is
By overlapping the front lens barrel component and the rear lens barrel component in any zoom range and by interposing an elastic member,
The front group and the rear group are tilted in the same direction, and the optical performance can be guaranteed. Further, with the above structure, it is possible to prevent light leakage from the rear lens barrel. Further, the above structure also improves the efficiency of assembly work.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a lens barrel according to an embodiment of the present invention,

2 is a sectional view taken along the line AA ′ of FIG.

FIG. 3 is a detailed view of the elastic member portion of FIG.

[Explanation of symbols]

 a front group lens b rear group lens 1 fixed lens barrel 2 front group moving ring 4 rear group lens barrel 11 elastic member

Claims (2)

[Claims] 1. An optical device having first and second moving lens barrels which are moved in the optical axis direction by a zoom operation, wherein the first lens barrel and the second lens are provided in the entire zoom operation. An optical device characterized in that an overlapping portion overlapping the lens barrel is provided, and an elastic member is arranged between the overlapping portions. 2. The elastic member is subjected to flocking treatment having a predetermined light blocking property while a pressing force is generated by a predetermined elastic force between the first lens barrel and the second lens barrel. The optical device according to claim 1, wherein: