JPS63287808A - Lens assembly - Google Patents

Abstract

PURPOSE:To improve an assembling property and to decrease the fluctuations in optical performance by providing plural pieces of lenses, split lens barrels which have grooves for holding the lenses on the inside surfaces and are bisected at the plane parallel with an optical axis, black adhesive members provided between the holding grooves and the lenses, and a means for coupling the split lens barrels to each other. CONSTITUTION:The lens 11 is pushed and fixed into the groove part constituted of a lens defining part 16 of the split lens barrel 10, the lens holding part 14 having the black adhesive layers 24 and an elastic piece 15. The lens 11 is pushed in the optical axis direction by deformation of the elastic piece 15, by which the lens spacing is maintained at this time. An antireflection effect in the rim part of the lens is obtd. by tight contact of the black adhesive layer 24 and the outside circumference of the lens 11. The other lenses 12, 13 are similarly pushed into the respective groove parts. Finally, the other split lens barrel 10 is put on the split lens barrel 10 into which all the lenses are inserted and a self-adhesive tape 26 is wound around the barrels, by which the split lens barrels 10 are brought into tight contact with each other and are fixed. The assembling property is thereby improved and the fluctuations in the optical performance are decreased with a smaller number of constituting parts.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a lens assembly for use in optical equipment such as a video camera.

2. Description of the Related Art In recent years, with the spread of video cameras, there has been a demand for lens assemblies that are easy to assemble and have little change in optical performance in order to be smaller and lighter and to shorten assembly time.

Hereinafter, an example of the conventional lens assembly mentioned above will be described with reference to the drawings.

FIGS. 4 and 5 show a sectional view and a perspective view of a conventional lens assembly. In FIG. 4, lenses 2.3 and 4.5 are inserted into the lens barrel 1 via a lens spacer 6.7.8, and are fastened by a ring 9. When assembling such a lens assembly, the fifth
As shown in the figure, insert lens 2 into lens barrel 1, place lens spacer 6 on top of lens 2, sequentially insert lens 3 and lens spacer 7, lens 4 and lens spacer 8, and then insert the last lens 5. After that, the ring 9 is tightened and fixed to the lens barrel 1. (For example, JP-A-60-43617
In addition, the outer periphery of the lens is painted black to prevent reflection (not shown).

Problems to be Solved by the Invention However, in the above configuration, since the lens and lens spacer are positioned by overlapping each other, tolerances in the width dimension of the lens spacer are accumulated, resulting in large variations in optical performance and poor performance of the lens. There was a problem in that workability was poor because the outer periphery was coated with anti-reflection black paint.

Means for Solving the Problems In order to solve the above problems, the lens assembly of the present invention includes a plurality of lenses, a holding groove for holding the lenses, and the holding groove on the inner surface. A lens barrel comprising a split lens barrel divided into two along a plane parallel to the optical axis, a black adhesive member provided between the holding groove and the lens, and a coupling means for coupling the split lens barrels together. It is.

Function When assembling a lens with the above-described configuration, the present invention includes the following steps:
The lenses can be inserted independently into the opening of one of the two divided lens holding frames in a direction perpendicular to the lens optical axis, making assembly easier, and the black adhesive on the outer periphery of the lens allows for reflection. Since it has a preventive effect, it is possible to eliminate the need for black coating on the outer periphery of the lens.

EXAMPLES Hereinafter, lens assemblies according to examples of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a lens assembly according to an embodiment of the present invention, and FIG. 2 is a plan view of a divided lens barrel.

In FIGS. 1 and 2, two identically shaped split lens barrels 1
0 is molded from glass-filled polycarbonate resin or the like, and lenses 11, 12, and 13 are inserted into the divided lens barrel 10. The outer peripheral part of the lens 11 is held by a lens holding part 14 on the inner peripheral surface of the divided lens barrel 10, and the lens 1 is held by an elastic piece 15 provided on the inner surface of the divided lens barrel 10.
1 against the lens regulating portion 16, positioning in the optical axis direction is performed. The lens regulating portion 16 is provided on the inner surface of the divided lens barrel 10 and is configured to be thicker than the elastic piece 15 (so as not to be deformed by the pressing force of the elastic piece 15).

Similarly, the lens 12 includes a lens holding portion 17 of the split lens barrel 10,
The lens 13 is fixed by the elastic piece 18 and the lens regulating part 19, and the lens 13 is fixed by the lens holding part 20. It is fixed by an elastic piece 21 and a lens regulating part 22.

FIG. 3 is a cross section cut along the X-X plane shown in FIG. 2, and there is a black adhesive layer 23 between the lens holding part 17 of the split lens barrel 10 and the outer peripheral part of the lens 12. . Similarly, the lens holder 14 includes a black adhesive layer 24 and a lens holder 20.
each has a black adhesive layer 25.

When assembling the lens assembly configured as described above, first, the lens regulating portion 16 of one of the split lens barrels 10, the lens holding portion 14 having the black adhesive layer 24, and the groove portion formed by the elastic piece 15 are assembled. Push the lens 11 in and fix it.

At this time, the elastic piece 15 deforms to press the lens 11 in the optical axis direction, maintaining the distance between the lenses, and by bringing the black adhesive layer 24 and the outer periphery of the lens 11 into close contact, the edge of the lens Provides anti-reflection effect. Similarly, the other lenses 12.13 are also pushed into their respective grooves.

Finally, the other divided lens barrel 1o is placed over the divided lens barrel 10 into which all the lenses have been inserted, and the lenses are attached to the respective grooves, and the two divided lens barrels 10 and lenses 11.12.1
3 and wrapping the adhesive tape 26 around the divided lens barrels 10, the divided lens barrels 10 are brought into close contact with each other.
Lens 11° 12.1 with black adhesive layer 23, 24.25
3 is fixed and the assembly is completed.

As described above, according to this embodiment, a holding groove for holding a lens, a divided lens barrel having the holding groove on the inner surface and divided into two along a plane parallel to the optical axis, and Equipped with a black adhesive member provided between the lens and a connecting means for connecting the split lens barrels, there is no need for anti-reflection black coating on the outer periphery of the lens, which facilitates assembly and improves optical performance. It is possible to obtain a lens assembly with less variation in .

Effects of the Invention As described above, according to the present invention, a lens spacer is not required, the number of component parts is small, and assembly is easy, and since tolerances in lens spacing do not accumulate, variations in optical performance can be reduced. This has the advantage of eliminating the need for anti-reflection coating on the outer periphery of the lens.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a lens assembly according to an embodiment of the present invention, FIG. 2 is a plan view of a divided lens barrel, and FIG. 3 is taken along line X-X in FIG.
4 is a sectional view of a conventional lens assembly, and FIG. 5 is an assembled perspective view thereof. 10...Divided lens barrel, 11, 12.13...
・・Lens, 14, 17.20 ・・・Lens holding part, 15° 18.21 ・・・・Elastic piece, 16.19
．． 22... Lens regulation section, 23, 24.25.
...Black adhesive layer, 26...Adhesive tape.

Claims (1)

[Claims] A plurality of lenses, a holding groove for holding the lenses, a divided lens barrel having the holding groove on the inner surface and divided into two along a plane parallel to the optical axis, and between the holding groove and the lens. A lens assembly comprising: a black adhesive member provided in the lens assembly; and a coupling means for coupling the divided lens barrels together.