JPS61215511A - Plastic lens holding device - Google Patents

Abstract

PURPOSE:To facilitate the assembly of a lens system and to facilitate the alignment of the lens system by forming a projection or recess on each end surface of a rod type leg or interval ring and holding adjacent lenses and a lens frame by engagement between a projection and a recess. CONSTITUTION:A plastic lens 7 inserted firstly when inserted into the lens frame 3 is made to about on an abutting surface 5, and projections 10 of interval rods 2 formed on the plastic lens 7 engage recesses 13 formed in the abutting surface 5. Then, other plastic lenses are inserted into an engagement part 12 similarly, but projections and recesses 11 of adjacent plastic lenses correspond to each other, so they engage each other to insert the plastic lenses one after another. Lastly, lens fixation surfaces 15 formed on spacing rods 2 of a plastic lens 8 overlap the part of an internal thread 6 in a thrust direction and the inserted lens system is held and fixed in the lens frame 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lens system using a plastic lens, and more particularly to a holding device for a lens system comprising a plurality of plastic lenses.

Conventional lens holding devices are disclosed in Utility Model Application Publication No. 53-40254,
Utility Model Application No. 54-151253 and Utility Model Application No. 55-5770
As disclosed in No. 9, a lens to be held is dropped into a lens barrel or a lens frame, and is fixed to the lens barrel using a screw type or bayonet press ring or caulking. However, with conventional lens holding devices, when holding a lens system consisting of multiple lenses, the distance between the lenses, which affects lens performance, is determined by the lens frame. must be maintained by. Therefore, it has been extremely difficult to hold and assemble a lens system consisting of a plurality of lenses, for example, to the extent that it is necessary to consider a fairly complicated automatic assembly machine in order to fully automatically assemble one lens system. In addition, plastic lenses are highly susceptible to thermal effects, and conventional lens holding devices have the disadvantage that expansion and contraction caused by heat can deform the plastic lenses, as each lens is fixed by a lens frame. .

Accordingly, an object of the present invention is to provide a plastic lens holding device that can extremely easily hold and assemble a lens system during automatic assembly work while maintaining lens performance.

Another object of the present invention is to provide a plastic lens holding device which has unique protrusions and depressions for mutually engaging adjacent plastic lenses to be mounted on a lens frame, thereby preventing assembly with incorrect parts during assembly work.

1 to 5 show a first embodiment of the invention.

Lens spacing rod 2 in the thrust direction of the plastic lens 1
As shown in FIG. 1, a protrusion 10 and a recess 11 are formed on the end surface of the lens spacing rod 2. In FIG. 2, the maximum diameter A of the plastic lens 1 is defined by the outermost part of the lens spacing rod 2, and the length defined by the centers of the protrusion 10 and the depression 11 is defined as the pitch circle B.

As shown in the third factor, the lens frame 3 that holds the lens system is formed with a fitting part 12 having an inner diameter large enough to insert the maximum diameter A of the spacing ring 2. One end of the portion 12 has an abutting surface 5 against which the spacing rod 2 is abutted while maintaining the effective diameter of the lens, and the abutting surface 5 has a contact surface 5 on which the lens spacing rod of the first inserted plastic lens is abutted. A depression or protrusion 13 corresponding to the protrusion or depression (
In this figure, a depression 13) is formed. Also, the fitting part 12
At the other end, an internal thread 6 having a larger diameter than the fitting part 12 is cut.

FIG. 5 shows the assembled state of the holding device. When the plastic lens 7 that is inserted first is inserted into the lens frame 3, it abuts against the abutting surface 5.
Since the spacing rod 2 of the plastic lens 7 has a depression 13 formed on the abutment surface 5 and a protrusion 10 corresponding to the size, number, and pitch circle B, the depression 13 on the abutment surface 5 The protrusion 10 of the plastic lens 7 is fitted into the hole. Subsequently, other plastic lenses are similarly inserted into the fitting part 12, but since the protrusions 10 and depressions 11 of adjacent plastic lenses correspond to each other, the plastic lenses can be inserted one after another by fitting them together. I can do it. Finally, insert the plastic lens 8.
The lens fixing surface 15 formed on the spacing ring 2 of the plastic lens 8 overlaps the inner diameter screw 6 in the thrust direction, and by pressing the lens fixing surface 15 in the thrust direction with the retaining ring 9, the inserted lens system is fixed. can be held and fixed to the mirror frame 3.

In this description, when the protrusion 10 and the depression 11 correspond, it means that the size, number, position, and pitch circle B are the same, and the protrusion 10 and the depression 11 can fit together.

Therefore, if the projections 10 and depressions 11 of adjacent plastic lenses in the lens system can fit together,
The size of each of the protrusion 1o and the depression 11 for a single lens,
The number, position, and pitch circle B may be different.

Furthermore, a plurality of lens spacing rods 2 on which the projections 10 or depressions 11 are formed may be formed in the thrust direction of the plastic lens 1.

Moreover, instead of forming the protrusion 10 or the depression 11 on the lens spacing rod 2, as shown in FIGS. The protrusion 10 or the depression 11 may be formed in the 22.

Thus, according to the first embodiment, the projection 10 or the depression 11 is provided on the lens spacing rod 2 or the spacing ring 22 that determines the lens spacing.
By forming this, it becomes easier to hold and assemble the lens system, and it also becomes easier to center the lens system. In particular, plastic lenses have a certain directionality in shape and performance, and by setting the positions of protrusions or depressions in advance according to the directionality, it is possible to bring out the advanced performance of a lens system made of plastic lenses. Furthermore, by changing the position and number of the protrusions or depressions on the lens spacing rod or spacing ring depending on the individual plastic lenses, it is possible to define the order of the lens system and eliminate defects during assembly.

FIGS. 8(a) and 8(b) show a second embodiment of the present invention. In the second embodiment, the lens fixing surface 1 of the first embodiment is
An elastic member or an elastic ring 16 having elasticity is interposed between the retaining ring 5 and the retaining ring 9. elastic ring 16
is ring-shaped, its inner diameter maintains the effective diameter of the lens, and its cross section may be of any shape such as an O-ring.

Thus, according to the second embodiment, when holding the lens system in the thrust direction, by interposing the elastic member in the lens holding part, the elastic member absorbs the expansion and contraction of the lens system in the thrust direction due to temperature changes, and the lens Deformation can be prevented.

Figures 9.10 and 11 show embodiments 3.4 and 5. Embodiments 3.4 and 5 have three mechanisms for pressing the lens fixing surface 15 of the last inserted plastic lens 8 in the thrust direction and for fixing the lens system by abutting it against the abutment surface 5 of the lens frame 3. This is an example.

The third embodiment shown in FIG. 9 is a mechanism for fixing a lens system by integrally forming an elastically deformable claw 17 on a retaining ring 9;
The fourth embodiment shown in FIG. 10 is a mechanism for fixing the retaining ring 9 to the lens frame 3 with a single adhesive and fixing the lens system with an elastic ring 16 interposed. In this example, the retaining ring 9 is fixed using a baratin method using a tapered recess formed in the lens frame 3 and a tapered protrusion 20 formed in the retaining ring 9, and the elastic ring 16 is interposed between the retaining ring 9 and the retaining ring 9. This is a mechanism that fixes the system.

Although the three mechanisms for fixing the lens system are illustrated above, any mechanism can be used as long as it fixes and holds the lens system by pressing it against the abutment surface 5 formed on the lens frame 3 in the thrust direction. I do not care.

As explained above, the present invention provides rod-shaped legs that determine the lens spacing integrally at the periphery of a plastic lens,
By holding the lens system made up of a plurality of plastic lenses inserted into the lens frame in one place, there is an effect that the lens system can be assembled extremely easily while maintaining a predetermined performance of the lens system.

Further, according to the present invention, a protrusion or a depression is formed on each end face of the rod-shaped leg or the spacing ring, and the adjacent lenses and the lens frame are held by the engagement between the protrusion and the depression, making assembly of the lens system easier. This has the effect of making it easier to center the lens system.

Furthermore, the present invention has the effect that by changing the position and number of the protrusions or depressions depending on the single plastic lens, the order of the lens system can be defined and defects during assembly can be eliminated. be.

[Brief explanation of drawings]

1 is an upper and lower sectional view of a lens section of a first embodiment of the present invention, FIG. 2 is a plan view taken along the line Uu in FIG. 1, and FIG. FIG. 4 is a plan view taken along line E in FIG. 3; FIG. 5 is an upper half sectional view showing the assembled state of the first embodiment of the present invention. , FIG. 6 is a sectional view showing a modified example of the lens portion, FIG. 7 is a plan view taken along the O-line in FIG. 6, and FIG. FIG. 8(b) is an upper half sectional view showing the second embodiment of the present invention in the assembled state as shown in FIG. 5, with an elastic ring interposed therebetween; FIG. 9 is a partial sectional view showing a third embodiment of the present invention;
FIG. 10 is a partial sectional view showing a fourth embodiment of the invention, and FIG. 11 is a partial sectional view showing a fifth embodiment of the invention. 1...Plastic lens, 2...Lens spacing rod (bar-like foot), 3...Mirror frame, 5...Abutting surface, 6...Screw, 7
...Plastic lens inserted first, 8...Plastic lens inserted last, 9...Retaining ring, 10.
・Protrusion, 11 ・Indentation, 12 ・Fitting part, 16 ・
...Elastic member. Figure 1 Figure 2 Figure 5

Claims (1)

[Claims] 1. A rod-shaped leg or a spacing ring surrounding the periphery of the plastic lens is integrally formed in the circumferential direction, and a lens adjacent to an end of the rod-shaped leg or spacing ring. A plastic lens holding device 2 characterized in that a protrusion or depression is formed to engage with the rod-shaped leg or the spacing ring, and the protrusion or depression provided at the end of the rod-shaped leg or spacing ring is formed so as to engage only with an adjacent lens. A plastic lens holding device according to claim 1, characterized in that: