TWI454782B - Lens group - Google Patents

Description

Lens group

The present invention relates to optical devices and, more particularly, to a lens assembly.

In recent years, with the advancement of optical technology, optical devices such as projectors, cameras, microscopes, etc. have become increasingly popular, and the lens groups used in the above optical devices have become the focus of many manufacturers' main production.

Many manufacturers, in manufacturing, usually design lenses of the same type of optical device under the same optical design, each having a different maximum magnification, thereby distinguishing the type or grade of the optical device.

In order to enable each lens to have different maximum magnifications, the manufacturer usually opens several cam barrels with different lengths of cam grooves according to the maximum magnification required for each lens, so that the lens can be under the same optical design. Each has a different maximum magnification.

However, the above-mentioned mold opening method of manufacturing a plurality of cam barrels having different lengths of cam grooves not only requires a large cost, but when a lens of a certain maximum magnification needs to be eliminated or replaced, all the cams corresponding to the maximum magnification must be corresponding. Discarding the cartridge will incur a waste of cost. Therefore, the conventional lens group design is still not perfect, and there is room for improvement.

In view of this, the main object of the present invention is to provide a lens group that can be required to change the maximum magnification of the lens group.

In order to achieve the above object, the lens assembly provided by the present invention comprises a fixed cylinder, a cam cylinder, at least one lens frame and a limiting member; wherein the cylinder wall of the fixing cylinder has at least one light parallel to the lens group a straight groove extending in the axial direction and at least one limiting hole; the cam cylinder is sleeved on the fixed cylinder and rotatable relative to the fixed cylinder; the cylinder wall of the cam cylinder has at least one cam groove in the cam cylinder When the fixed cylinder rotates within a predetermined angle, it can communicate with the straight groove, and a limiting groove communicates with the limiting hole; the lens frame is disposed in the fixing cylinder, and the lens frame has at least one convex axis Simultaneously located in the straight groove and the cam groove, when the cam barrel rotates, the protruding shaft moves along the cam groove and the straight groove simultaneously; the limiting member passes through the limiting groove and is combined with the limiting hole. And when the cam barrel is rotated to an angle, the restricting member will abut one of the groove walls at both ends of the limiting groove, and the cam barrel is limited to the angle.

Thereby, the angle of rotation of the cam barrel is restricted by the limiting member, thereby limiting the maximum magnification of the lens, thereby achieving the purpose of changing the maximum magnification of the lens group.

In order that the present invention may be more clearly described, the preferred embodiments are illustrated in the accompanying drawings.

Referring to FIG. 1 and FIG. 2, the lens assembly of the preferred embodiment of the present invention includes a fixed cylinder 10, a cam cylinder 20, four lens frames 31-34, and a restraining member 40. among them:

The cylinder wall of the fixed cylinder 10 has three straight grooves 12 and a limiting hole 14 which are equidistantly distributed on the wall of the fixed cylinder 10, and each of the straight grooves 12 has a certain length and along It extends parallel to the direction of the optical axis of the lens group. The limiting hole 14 is a screw hole.

The cam barrel 20 is sleeved on the fixed cylinder 10 so as to be rotatable relative to the fixed cylinder 10. The cylinder wall of the cam barrel 20 has three first cam grooves 21, three second cam grooves 22, three third cam grooves 23 and three fourth cam grooves 24, and the cam barrel 20 and the fixed cylinder 10 are in a state. When the rotation is within a predetermined angle, each of the first cam groove 21, each of the second cam grooves 22, each of the third cam grooves 23, and each of the fourth cam grooves 24 may be corresponding to the straight groove 12 corresponding to the fixed cylinder 10. Connected. In addition, the cylinder wall of the cam barrel 20 further has a limiting groove 25 located at a side end of the cam barrel 20 and communicating with the limiting hole 14 of the fixing cylinder 10.

The four lens frames 31-34 are respectively a first lens frame 31, a second lens frame 31, a third lens frame 33 and a fourth lens frame 34, and a lens is respectively disposed in the lens frames 31-34. Group 51~54. The lens frames 31 to 34 are sequentially disposed in the fixed cylinder 10, and three convex shafts 31a to 34a are respectively disposed on the outer periphery of each of the lens frames 31 to 34. Each of the protruding shafts 31a of the first lens frame 31 passes through the corresponding first cam groove 21 and is located in each of the straight grooves 12; each of the convex shafts 32a of the second lens frame 32 passes through the corresponding The second cam groove 22 is located in each of the straight grooves 12; and each of the protruding shafts 33a of the third lens frame 33 passes through the corresponding third cam groove 23 and is located in each of the straight grooves 12; Each of the male shafts 34a of the four lens holders 34 passes through the corresponding fourth cam grooves 24 and is located in each of the straight grooves 12.

Therefore, referring to FIG. 3 and FIG. 4, when the cam barrel 20 and the fixed cylinder rotate within the predetermined angle, the convex shafts 31a-34a of the lens frames 31-34 will follow the corresponding cam grooves 21~ 24 moves and moves the straight grooves 12 to change the positions of the lens groups 51 to 54 to achieve the purpose of changing the magnification.

In addition, in the embodiment, the limiting member 40 is a screw corresponding to the limiting hole 14. When the user wants to adjust the maximum magnification of the lens group, the limiting member 40 passes through the limiting slot 25 and is screwed. The limiting hole 40 is disposed in the limiting hole 14 . Therefore, when the cam barrel 20 is rotated to an angle, the limiting member 40 will abut against the groove wall at both ends of the limiting slot 25, and The cam barrel 20 is constrained to the angle, and the angle is smaller than a predetermined angle at which the cam barrel 20 can rotate, which causes the convex shafts 31a-34a of the lens frames 31-34 to stop at opposite ends of the corresponding cam groove 12. Between, and thus achieve the purpose of reducing the maximum magnification of the lens group. For example, the stroke of the cam grooves 12 of the lens group can be designed such that the maximum magnification of the lens group reaches 1.8, and then the position of the limiting hole 14 is transmitted through the position of the limiting hole 14 so that the limiting member 40 is connected. The groove wall of the limiting slot 25 limits the angle of rotation of the cam barrel 20, so that the maximum magnification of the lens group is reduced to other magnifications in the stroke of the cam grooves 12 (such as 1.7, 1.6 or 1.5). .

It should be noted that, in addition to the combination of the screw and the screw hole, the limiting member and the limiting hole of the present invention may also use a pin and a through hole, or other feasible manner to limit the angle of rotation of the cam barrel. In addition, the limiting holes on the fixing cylinder of the present invention can also be increased to two, three or more according to requirements to correspond to different magnifications. The above description is only for the preferred embodiment of the present invention, and the equivalent structure and method variations of the present invention and the scope of the patent application are intended to be included in the scope of the present invention.

10. . . Fixed cylinder

12. . . Straight slot

14. . . Limit hole

20. . . Cam barrel

twenty one. . . First cam groove

twenty two. . . Second cam groove

twenty three. . . Third cam groove

twenty four. . . Fourth cam groove

25. . . Limit slot

31~34. . . Lens holder

31a~34a. . . Convex axis

40. . . Restriction

51~54. . . Lens group

Figure 1 is an exploded view of the lens assembly of the present invention.

2 to 4 are perspective views of the lens group of the present invention.

Figure 5 discloses the use of a limiter to adjust the maximum magnification of the lens group.

10. . . Fixed cylinder

12. . . Straight slot

14. . . Limit hole

20. . . Cam barrel

twenty one. . . First cam groove

twenty two. . . Second cam groove

twenty three. . . Third cam groove

twenty four. . . Fourth cam groove

25. . . Limit slot

31~34. . . Lens holder

31a~34a. . . Convex axis

40. . . Restriction

51~54. . . Lens group

Claims (5)

A lens assembly includes: a fixed cylinder having at least one straight groove extending in a direction parallel to an optical axis of the lens group and at least one limiting hole; a cam barrel sleeved on the fixed cylinder And rotating relative to the fixed cylinder; the cylinder wall of the cam cylinder has at least one cam groove communicating with the straight groove when the cam cylinder rotates within a predetermined angle with the fixed cylinder, and a limiting slot and The limit hole is connected; at least one lens frame is disposed in the fixed cylinder, and the lens frame has at least one convex axis located in the straight groove and the cam groove simultaneously, and when the cam barrel rotates, the convex axis is simultaneously The cam groove and the straight groove move; and a limiting member is coupled to the limiting hole through the limiting groove, and when the cam barrel is rotated to an angle, the limiting member and the limiting groove are One of the end groove walls abuts, and the cam barrel is limited to the angle. The lens unit of claim 1, wherein the limiting hole is a screw hole, and the limiting member is a screw that cooperates with the screw hole. The lens group of claim 1, wherein the limiting slot is located at a side of the cam barrel. The lens assembly of claim 1, wherein the limiting member is in contact with one of the slot walls at both ends of the limiting slot to limit the cam cylinder to the angle, the protruding shaft is located in the cam slot Between the ends. The lens unit of claim 1, wherein the limiting member abuts one of the slot walls at both ends of the limiting slot to cause the cam barrel to stop at an angle less than the predetermined angle.