JPH09105851A - Zoom binoculars - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a zoom binoculars whose visual field does not become narrow at low power. SOLUTION: The zoom binoculars has the composite focal length made constant by fixing the mutual interval between the oculars, object internal barrels 1 having longitudinal grooves 1a where objective lens systems are stored are fixed behind erect prisms P1 and P2 in the right and left main bodies, and objective external barrels 2 having cam grooves 2a and 2b cut are arranged outside the objective internal barrels 1 and connected by a cord 10; and the objective external barrels 2 are rotated with a zooming lever 11 to rotate the right and left objective external barrels 2 and 2' at the same time and objectives 4 and 5 in 2nd and 3rd groups in the objective lens groups stored in the objective internal barrels 1 are moved individually through the longitudinal grooves 1a of the objective internal barrels 1 along the cam grooves 2a and 2b of the objective external barrels 2 and 2' to vary the power by the 2nd groups. An image spot is corrected by the 3rd groups to zoom the binoculars. Thus, a visual field of low power is widened to make it easy to observe sports or a body which moves fast.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to zoom binoculars used for single objective or dual objective binoculars.

[0002]

2. Description of the Related Art In conventional zoom binoculars, an objective lens having a positive refracting power composed of a plurality of lenses, an erecting prism system, and a first refracting power having a negative refracting power from the erecting prism side.
A variable power eyepiece mainly composed of a lens group, a second lens group having a positive refractive power, and a third lens group having a positive refractive power is a mainstream. The lens is used to correct the magnification and the image point (diopter) by moving the first lens group and the second lens group.

[0003]

This variable power eyepiece has been widely used in the past for realizing zoom binoculars with a relatively simple structure. However, in order to obtain a large magnification ratio, the third lens group is used. The distance of the second lens group must be set large, but since the second lens group is placed within the focal length of the third lens group, scratches and dust of the second lens group appear to be enlarged, so that distance is naturally limited. Moreover, it is difficult to use a large zoom ratio due to the shape and size of the eyepiece that comes from the portability of the binoculars, and the diameter of the second lens group cannot be made large, so the apparent field of view at low magnification is low. It has a defect that (the actual magnification of the binoculars multiplied by the actual field of view) becomes narrow at 35 ° to 40 °.

[0004]

The object of the present invention is to eliminate the drawback that the field of view is narrowed at low magnification and to propose zoom binoculars for obtaining a large zoom ratio. It is as follows.

[0005] 1. The mutual distance between the eyepieces is fixed to keep the combined focal length of the eyepiece constant, and the objective inner cylinder with the vertical groove that accommodates the objective lens system is fixed to the rear part of the erecting prism in the left and right main bodies, and the objective inner cylinder is fixed. By disposing two objective outer cylinders with two cam grooves cut out, connecting the left and right objective outer cylinders with a string, and rotating the objective outer cylinders with a zooming lever, the left and right objective outer cylinders rotate at the same time. In addition, the pins protruding from the objective lenses of the second group and the third group among the objective lens groups housed in the objective inner tube through the vertical groove of the objective inner tube with respect to the cam groove of the objective outer tube Zoom binoculars configured to perform zooming by changing the focus in the second lens group and correcting the focus error in the third lens group by engaging them respectively.

[0006] 2. 2. The zoom binoculars as described in 1 above, wherein the left and right objective outer cylinders are connected by belts and are rotated simultaneously. 3. 2. The zoom binoculars as described in 1 above, wherein the left and right objective outer cylinders are connected by gears and are rotated simultaneously. 4. From the first lens group having positive refracting power in order from the object side, the second lens group having negative refracting power, the third lens group having negative refracting power, and the fourth lens group having positive refracting power, a total of four lens groups Consisting of an objective lens, an erecting prism system, and an eyepiece lens having a positive refractive power, the second lens group mainly moves during zooming, and the associated image point movement is corrected by the third lens group, and the first lens group is an object. In order from the side, a negative meniscus lens having a convex surface on the object side and a convex lens cemented with this lens or arranged with some distance therebetween are provided.
The group is composed of a biconcave lens and a positive meniscus lens having a strong surface on the object side, which is arranged at some point from the biconcave lens, the third group is composed of a negative meniscus lens, and the fourth group is composed of a biconvex lens. 4. The zoom binoculars according to 1 or 2 or 3 above, characterized in that the zoom binoculars are composed of this and a concave lens arranged at a slight space.

[0007]

When the zooming lever is operated, the left or right objective outer cylinder rotates. This rotation is transmitted to the left or right objective lens barrel via a string or belt, so that the left and right objective lens barrels rotate at the same time. When the objective outer cylinder rotates, the objective lenses of the second and third groups housed in the objective inner cylinder move back and forth by the action of the pin protruding from this lens, the vertical groove of the objective inner cylinder, and the cam groove of the objective outer cylinder. Then, zooming and image point correction are performed.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail with reference to FIGS. In the zoom binoculars shown in FIGS. 1 and 2, the left and right objective lens barrels for accommodating the left and right objective lens groups are provided with an inner objective tube 1 having a vertical groove 1a and a cam groove 2 provided outside thereof.
and an objective outer cylinder 2 having a and b, and a focal lens 3, a variator lens (objective second group lens) 4, a compensator lens (objective third group lens) 5, in the left and right objective inner tubes 1. An eyepiece 7, 8 in which an afocal lens and an objective lens of basic binoculars are arranged in this order, and the erecting prisms P1, P2 or roof prisms are fixed to the rear of the lens 6 so that the mutual focal distance is fixed and the combined focal length is constant. ,
9 are arranged to hold the variator lens 4 and the compensator lens 5 in the left and right objective inner cylinders 1 and 1'into the lens frames 4'and 5 ', respectively, and pin screw holes 4a' of the lens frames 4 and 5 '. Pin 4a and pin 5a fixed to 5a ',
The vertical grooves 1a of the left and right objective inner cylinders 1, 1'and the left and right objective outer cylinders 2,
2'cam grooves 2a, 2b make it slidable,
The left and right objective outer cylinders 2 and 2'are connected by a string 10 or a belt, and are concentric with the left objective outer cylinder 2 or the right objective outer cylinder 2'and rotate with the left objective outer cylinder 2 or the right objective outer cylinder 2 '. By moving the zooming lever 11 that is freely attached, the gear 13 that is attached to the lower inner cover 14 and that meshes with the zooming lever 11 and the gear 12 that is integral with the gear 13 rotate, and the gear 12 meshes with the left objective outer cylinder 1. Alternatively, the gear integrated with the right objective outer cylinder 1 ′ rotates, and the string (or belt) 10,
The outer objective cylinder on the opposite side rotates through the pulley 10 'and the variator lens 4 and the compensator lens 5 of the left and right objective inner cylinders 1 and 1 slide simultaneously to perform zooming.

FIG. 2 is an exploded perspective view of the lens frame 4'of the variator lens 4, the lens frame 5'of the compensator lens 5, the objective inner cylinder 1 and the objective outer cylinder 2. The variator lens 4 and the compensator lens 5 are shown in FIG. Pins 4a, 5a (see FIG. 1) fixed to the lens frames 4 ', 5'of the respective lenses engage with the cam grooves 2a, 2b via the vertical grooves 1a, respectively, and the variator lens 4 changes its focus (magnification), The compensator lens 5 corrects the image point.

[0010]

As described above, according to the present invention, the zooming is performed by moving the objective second lens group for zooming and the objective third lens group for image point correction at the same time. Play. a. The apparent field of view at low magnification is 35 ° to 40 ° of the conventional
65 ° by using a wide-field eyepiece compared to
The angle becomes up to 70 °, which makes it possible to widen the field of view 1.6 to 2 times that of the conventional one. As a result, it is convenient for watching sports with fast movement or observing objects, birds, etc. moving at high speed. b. By changing the focal length and the mutual distance between the objective first lens group and the objective second lens group, the zoom ratio can be dramatically increased as compared with the eyepiece variable power zoom binoculars. c. By incorporating the zooming mechanism into the left and right objective cylinders, the zoom binoculars can be downsized.

[Brief description of the drawings]

FIG. 1 is a plan view in which a part of zoom binoculars according to the present invention is sectioned.

FIG. 2 is an exploded perspective view of a second objective lens frame, a third objective lens frame, an objective inner barrel, and an objective outer barrel.

[Explanation of symbols]

 1 Objective Inner Cylinder 2 Objective Outer Cylinder 3 Objective Lens 4 Variator Lens 5 Compensator Lens 7 ・ 8 ・ 9 Eyepiece 10 String 11 Zooming Lever

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[Procedure amendment]

[Submission date] December 15, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005] 1. The mutual distance between the eyepieces is fixed to keep the combined focal length of the eyepiece constant, and the objective inner cylinder with the vertical groove that accommodates the objective lens system is fixed to the rear part of the erecting prism in the left and right main bodies, and the objective inner cylinder is fixed. An outer objective cylinder having two cam grooves cut is arranged on the outer side, the left and right objective outer cylinders are connected by a string so that the left and right objective outer cylinders rotate at the same time, and with respect to the cam grooves of the objective outer cylinder. Of the objective lens group housed in the objective inner tube through the vertical groove of the objective inner tube, the pins projected from the objective lenses of the second group and the third group are engaged with each other, so that the focus of the second group is increased. Zoom binoculars configured to perform zooming by making changes and correcting focus errors in the third lens group.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007]

[Operation] The left or right objective outer cylinder is rotated by a zooming lever or the like . This rotation is transmitted to the left or right objective lens barrel via a string or belt, so that the left and right objective lens barrels rotate at the same time. When the objective outer cylinder rotates, the objective lenses of the second and third groups housed in the objective inner cylinder move back and forth by the action of the pin protruding from this lens, the vertical groove of the objective inner cylinder, and the cam groove of the objective outer cylinder. Then, zooming and image point correction are performed.

Claims (4)

[Claims] 1. An objective inner cylinder having a vertical groove for accommodating an objective lens system is fixed at the rear of the erecting prism in the left and right main bodies by fixing the mutual distance between the eyepieces to keep the eyepiece combined focal length constant. By disposing two objective grooved outer cylinders outside the objective inner tube, connecting the left and right objective outer tubes with a string, and rotating the objective outer tube with a zooming lever, the left and right objective outer tubes Of the objective lenses of the second and third groups among the objective lens groups housed in the objective inner cylinder through the longitudinal grooves of the objective inner cylinder with respect to the cam grooves of the objective outer cylinder. By engaging the protruding pins respectively,
Zoom binoculars configured to perform zooming by changing the focus in the second group and correcting the focus error in the third group. 2. The zoom binoculars according to claim 1, wherein the left and right objective outer cylinders are connected by belts and are rotated simultaneously. 3. The zoom binoculars according to claim 1, wherein the left and right objective outer cylinders are connected by gears and are rotated simultaneously. 4. A first lens element having positive refractive power in order from the object side.
Group, second group with negative refractive power, third group with negative refractive power
Group, an objective lens composed of a total of four lens groups of a fourth lens group having a positive refracting power, an erecting prism system, and an eyepiece lens having a positive refracting power, and the second group mainly moves during zooming, The associated movement of the image point is corrected by the third lens unit, and the first lens unit is composed of, in order from the object side, a negative meniscus lens element convex to the object side and a convex lens element that is cemented with this lens element or is provided with some distance between them. Then, the second group is composed of a biconcave lens and a positive meniscus lens having a strong surface on the object side, which is arranged with some distance from this, the third group is composed of a negative meniscus lens, and the fourth group is 4. The zoom binoculars according to claim 1, 2 or 3, wherein the zoom binoculars are composed of a biconvex lens and a concave lens which is cemented with the biconvex lens or arranged with a slight space.