Optical element, optical thin film forming device, and optical thin film forming method

Abstract

When forming an optical thin film (14) on the curved surface (3a) of the film-forming material (3), between the disposition part (4) and the target (5) as part of the space in the processing chamber (2) The specific space (8) is surrounded by the shielding part (9) in advance. In this state, an optical thin film having substantially the same optical film thickness is formed on the curved surface when film formation is performed by the following sputtering process in which an active gas and an inert gas are supplied in a vacuum state. A voltage is applied to the target (5) in the gas treatment chamber (2).

Description

technical field [0001] The present invention relates to an optical element in which an optical film is formed on a curved surface of a film-forming material such as a curved substrate or an optical lens, an optical thin film forming apparatus for forming the optical thin film thereof, and an optical thin film forming method. Background technique [0002] As a type of optical film, for example, an antireflection film is well known. In order to prevent the reduction of the loss of transmitted light and the occurrence of ghost flare, etc., on the surface of an imaging lens attached to a digital camera, etc., a projection lens attached to a liquid crystal projector, etc., or a cover glass of an optical device, etc. layer of anti-reflective coating. The antireflection film needs to be formed so that the desired antireflection characteristics can be obtained without causing a film thickness distribution of the optical film thickness. When forming an anti-reflection film on the l...

AI Technical Summary

Problems solved by technology

For example, when forming a film on the concave surface of a concave meniscus lens used as a camera lens, it is difficult to form a film on the peripheral part, and the physical film thickness tends to be thinner than that on the central part.

Therefore, it is easy to cause a difference in reflectance exceeding the allowable range due to the distribution of the optical film thickness between the center of the lens surface and its periphery.

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