KR20170006017A

KR20170006017A - calcogenide lens composition compatible with glass mold processing and method of manufacturing lens using the same

Info

Publication number: KR20170006017A
Application number: KR1020150096329A
Authority: KR
Inventors: 최주현; 김혜정; 김정호; 차두환
Original assignee: 한국광기술원
Priority date: 2015-07-07
Filing date: 2015-07-07
Publication date: 2017-01-17

Abstract

The present invention relates to a chalcogenide lens composition compatible with mold processing which is composed of 22.6-27.5 wt% of Ge, 12.5-17.5 wt% of Sb, and 60 wt% of Se. According to such chalcogenide lens composition compatible with the mold processing and a method of manufacturing a les using the composition, advantages in manufacturing a high-quality lens with high accuracy because of great mold release and transcription can be provided.

Description

[0001] The present invention relates to a chalcogenide-based lens composition suitable for a mold-forming process, and to a lens manufacturing method using the same,

The present invention relates to a chalcogenide-based lens composition suitable for a molding process and a lens manufacturing method using the same.

Lenses are used as a key element in optical instruments such as microscopes, telescopes, and digital cameras.

Various manufacturing methods such as a polishing method, a compression molding method, and an injection method are applied to a general lens manufacturing method.

In the case of compression molding, the object to be molded is put into a mold (hereinafter referred to as a mold) so that the object to be molded can be processed corresponding to the shape of the cavity formed by the upper mold and the lower mold through the combination of the upper mold and the lower mold .

Such a lens manufacturing method is variously exemplified by the disclosure of Japanese Patent Application Laid-Open No. 10-2007-0096938.

On the other hand, in the case of a lens, since the refractive index of light is changed by the shape, the processing precision of the lens is very important.

However, in the case of a method of manufacturing a lens by inserting a glass-based base material manufactured in a preform form between upper and lower molds, the base material is fused to the mold and is not easily separated from the mold, so that it is difficult to obtain desired surface precision. In this case, There is a disadvantage that the surface must be machined.

It is an object of the present invention to provide a chalcogenide-based lens composition having excellent mold releasability and moldability, and a lens manufacturing method using the same, in order to solve the above-mentioned problems.

In order to achieve the above object, a chalcogenide-based lens composition suitable for a mold molding process according to the present invention is a composition for producing a lens through a molding process, comprising 22.5 to 27.5% by weight of Ge, 12.5 to 17.5% Se 60% by weight.

According to another aspect of the present invention, there is provided a method of manufacturing a lens using a chalcogenide-based lens composition. Ge 22.5 to 27.5% by weight, Sb 12.5 to 17.5% by weight, Se 60% by weight; I. Inserting the preform into the chamber between the upper and lower molds and then preheating the chamber interior to the softening temperature of the preform; All. Pressing between the upper and lower molds at a pressure of 0.4 to 0.6 KN to form a mold; la. And cooling the inside of the chamber to 190 to 210 ° C.

Preferably, step (b) Preheating the interior of the chamber to 325 to 335 DEG C for 120 to 300 seconds; I-2. And secondarily preheating the interior of the chamber at 326 to 345 DEG C for 60 to 180 seconds.

Also, the multi-step is performed for 60 to 200 seconds, and the La step is performed for 120 to 240 seconds.

The present invention provides a chalcogenide-based lens composition suitable for a mold molding process according to the present invention and a method for manufacturing a lens using the same, which provides advantages of high quality and high precision in mold release and transferability.

1 is a sectional view showing a mold molding apparatus for explaining a process of manufacturing a lens using a chalcogenide-based lens composition according to the present invention,
FIG. 2 is a cross-sectional view showing a state in which the upper mold of FIG. 1 is lowered,
3 is a process diagram showing a lens manufacturing process according to the present invention.

Hereinafter, a chalcogenide-based lens composition suitable for a molding process according to a preferred embodiment of the present invention and a method of manufacturing a lens using the same will be described in detail with reference to the accompanying drawings.

First, the chalcogenide-based lens composition according to the present invention for producing a lens through a molding process is composed of 22.5 to 27.5% by weight of Ge, 12.5 to 17.5% by weight of Sb and 60% by weight of Se.

Such a lens composition has a transmittance of 60% or more for light having a wavelength of 8 to 12 micrometers, a glass transition temperature of 270 to 300 캜, a Vickers hardness of 170 kgf / mm ² And has good moldability and transferability when molded through a mold.

The present lens composition can be used for producing an infrared optical lens.

Hereinafter, a process of manufacturing a lens using such a lens composition will be described with reference to FIGS. 1 to 3. FIG.

First, a preform 50 composed of 22.5 to 27.5% by weight of Ge, 12.5 to 17.5% by weight of Sb and 60% by weight of Se is prepared (step 110).

Here, the preform 50 was prepared by injecting a composition composed of 22.5 to 27.5% by weight of Ge, 12.5 to 17.5% by weight of Sb and 60% by weight of Se into a quartz tube and sealing the resultant at a melting temperature of 900 to 110 DEG C for 12 hours The quartz tube may be shaken while being shaken and then quenched in water to form an ingot shape, followed by processing in the form of a desired preform 50 by polishing.

Here, the shape of the preform 50 may be suitably applied appropriately roughly to the lens to be formed.

Next, the prepared preform 50 is formed by using the upper and lower molds 40 and 30.

First, as shown in FIG. 1, a preform 50 is inserted between a lower mold 30 and an upper mold 40 in a chamber 10 (step 120), and the interior of the chamber 10 is filled with a preform 50 ). &Lt; / RTI >

Reference numeral 35 denotes a guide pipe for supporting the upper mold 40 and the lower mold 30 from the outside and guiding the sliding of the upper mold 40.

Further, the chamber 10 is provided with an inlet 12 through which gas can be supplied to the internal accommodation space and an outlet 14 through which the gas in the internal accommodation space is discharged.

The lower mold 30 and the upper mold 40 may be made of a known material such as one made of cemented carbide such as tungsten carbide (WC).

A cavity formed between the upper mold 40 and the lower mold 30 corresponds to a lens to be formed.

The preheating process is preheated to a softening temperature which is set higher than the glass transition temperature so that the preform 50 can be deformed by the subsequent pressing process.

The softening temperature applied to the preform 50 is preferably 325 to 345 DEG C, which is higher than the glass transition temperature.

Preferably, the preheating process first preheats the chamber interior to 325 to 335 占 폚 for 120 to 300 seconds (step 130), and secondarily preheats the chamber interior to 326 to 345 占 폚 for 60 to 180 seconds (step 140) desirable.

In the preheating process, the upper mold 40 is kept spaced apart from the lower mold 30 so that the pressing force is not applied to the preform 50.

Next, the presser 60 is moved downward to press the upper and lower molds 40 and 30 to apply a pressing force of 0.4 to 0.6 KN (step 150), and the molding process is performed as shown in FIG. 2 .

It is preferable that the pressing process is performed at 325 to 335 ° C for 60 to 200 seconds so that cracking and fusion do not occur while securing mold releasability and transferability during molding.

Thereafter, the inside of the chamber 10 is cooled to 190 to 210 ° C (step 160), cooled and held for about 120 to 240 seconds, and demolded (step 170).

From the preheating to the cooling process, the forming process is performed in a nitrogen atmosphere while supplying nitrogen through the inlet 14 of the chamber.

In order to confirm the releasability of the lens manufactured through such a manufacturing process, specimens having different composition ratios were applied as shown in Table 1 below to manufacture a lens.

Psalm name Ge (W%) Sb (W%) Se (W%) MCN S1 30 10 60 2.7 S2 27.5 12.5 60 2.675 S3 25 15 60 2.65 S4 22.5 17.5 60 2.625

The mean MCN (coordination number) is the mean number of coordinates.

As a result of measuring the durability of the prepared specimens, the specimens S2, S3, and S4 corresponding to the composition ratios according to the present invention had sufficient releasability and a roughness average of 15 nm or less. On the other hand, it was confirmed that the specimen S1 had a problem of fusion to the mold after the lens composition.

According to the chalcogenide-based lens composition suitable for the mold molding process described above and the lens manufacturing method using the same, it is possible to manufacture a high-quality lens having high moldability and transferability and high precision during molding.

10: chamber 30: lower mold
40: upper mold 50: preform

Claims

A composition for producing a lens through a mold forming process, comprising: 22 to 27.5% by weight of Ge, 12.5 to 17.5% by weight of Sb, and 60% by weight of Se.

end. Ge 22.5 to 27.5% by weight, Sb 12.5 to 17.5% by weight, Se 60% by weight;
I. Inserting the preform into the chamber between the upper and lower molds and then preheating the chamber interior to the softening temperature of the preform;
All. Pressing between the upper and lower molds at a pressure of 0.4 to 0.6 KN to form a mold;
la. And cooling the inside of the chamber to 190 to 210 ° C.

3. The method of claim 2,
I -1. Preheating the interior of the chamber to 325 to 335 DEG C for 120 to 300 seconds;
I-2. And secondarily preheating the interior of the chamber to 326 to 345 DEG C for 60 to 180 seconds.

4. The method of claim 3, wherein the multi-step is performed for 60 to 200 seconds,
Wherein the step a) is performed for 120 to 240 seconds.

5. The method according to claim 4, wherein nitrogen is supplied into the chamber while performing nitrogen gas atmosphere.