JPH0553037A - Objective lens - Google Patents

Abstract

PURPOSE:To obtain the objective lens on which dust and a foreign matter do not remain behind, in an applied device using a high output laser by providing an opening doe eliminating a closed space on the side face of a cylinder of the objective lens. CONSTITUTION:In a lens barrel 1, lenses 4, 5 contained in lens holders 2, 3 are installed. Also, on the side face of the lens barrel 1 between these lenses 4, 5 a hole 7 is provided in advance. In such a way, even if dust which intrudes at the time of assembling the objective lens, and a minute foreign matter generated by contact of parts of the lenses 4, 5 themselves remain behind in a space between the lenses 4, 5, they are taken out easily to the outside from the hole 7 by cleaning this objective lens by a liquid or gas after the assembly. In such a way, even if dust and a minute foreign matter which remain behind between the lenses 4, 5 at the time of assembling the objective lens exist, they can be eliminated easily by washing the assembly, therefore, seizure and damage do not occur as the objective lens of a high output laser applied device. Also, since there is no closed space, a cooling characteristic of the objective lens is improved by making the hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens used in a laser processing apparatus or a laser irradiation apparatus, and particularly in a laser application apparatus using a high output laser.

[0002]

2. Description of the Related Art As an example of a conventional objective lens, FIG. 2 shows the one shown in 839p, "Optical Handbook", Asakura Shoten, 5th edition, October 30, 1969, edited by Hiroshi Kubota et al.

In FIG. 2, lenses 4 and 5 housed in lens hosts 2 and 3 are mounted in a lens barrel 1.

[0004]

When an objective lens having such a structure is used in a laser processing apparatus that uses a high-power laser or a laser application apparatus such as a laser irradiation apparatus, dust and assembled parts are generated when the objective lens is assembled. Even if the minute scraps of erroneously enter the closed space 6, they cannot be removed. Therefore, when applied to high-power laser application equipment,
The laser light hits the dust and minute debris trapped in the closed space, causing the lens to burn or damage.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide an objective lens which does not confine foreign matter in the lens which may cause damage to the lens by laser light.

[0006]

In order to achieve the above object, a hole is formed in the side surface of the lens barrel so that foreign matter can be removed at any time.

[0007]

[Function] By making a hole in the side surface of the lens barrel,
It is possible to remove dust that enters during lens assembly and minute foreign substances generated by contact between the components of the objective lens by cleaning after assembly. To remove dust and foreign matter inside the conventional objective lens by re-disassembly and assembly,
After removing it, there is a possibility that new foreign matter may be trapped inside during reassembly, which is no solution.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, lenses 4 and 5 housed in lens holders 2 and 3 are mounted in a lens barrel 1. Then, a hole 7 is provided on the side of the lens barrel between the lenses. By doing this, even if dust that enters when assembling the objective lens or fine foreign matter generated due to contact of parts of the lens itself remains in the space between the lenses, by cleaning the objective lens with liquid or gas after assembly. , You can now easily take it out from the hole.

[0010]

Since the present invention is constructed as described above, it has the following effects.

First, even if there is dust or minute foreign matter remaining in the space between the lenses when the objective lens is assembled, it can be easily removed by washing after assembly, and the objective of the high power laser application device can be removed. It is now possible to provide an objective lens that does not cause seizure or damage as a lens.

Further, as another effect, since the closed space is eliminated, the cooling characteristic of the objective lens is improved by making the hole.

[Brief description of drawings]

FIG. 1 is a sectional structural view of an embodiment of the present invention.

FIG. 2 is a diagram showing a cross-sectional structure of a conventional objective lens.

[Explanation of symbols]

1a ... lens barrel, 2 ... lens holder, 3 ... lens holder, 4 ... lens, 5 ... lens, 7 ... hole.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Katsuro Mizukoshi, Katsuro Mizukoshi, 292 Yoshida-cho, Totsuka-ku, Yokohama City, Hitachi, Ltd. Inside the technical laboratory

Claims (1)

[Claims] 1. An objective lens, characterized in that an opening for eliminating a closed space is provided on a side surface of a cylinder of the objective lens.