Optical filter

Abstract

The invention discloses an optical filter, which comprises a substrate and optical films on the two sides of the substrate, wherein the substrate is a blue plastic substrate; a blue glass substrate is substituted by the blue plastic substrate; and thus, the production cost, the product weight and the product size can be reduced and the yield of products can be improved. In a preferred technical scheme, in order to improve the adhesion between the substrate and the optical films on the two sides of the substrate, an HfO2 transition layer is arranged between the substrate and the optical films. In order to improve the deformation of the blue plastic substrate, the optical films are an infrared ray isolating filter film on one side of the substrate and an infrared-ultraviolet ray isolating filter film on the other side of the substrate. The optical filter has the advantages of low cost, light weight, small size and capability of being widely used for card type cameras, mobile phone cameras, monitoring systems and the like with small image chip areas, particularly intelligent mobile phones increasingly used at present.

Description

technical field [0001] The invention relates to the field of filters for digital photography, in particular to a low-stress plastic optical filter mainly used in image acquisition systems such as card-type digital cameras, mobile phone cameras and monitoring cameras. Background technique [0002] The image sensor CCD (Charge-coupled Device, charge-coupled device) and the image sensor CMOS (Complementary Metal-Oxide Semiconductor, metal oxide semiconductor element) used in digital imaging technology are photodetectors of a kind of discrete pixels. According to the Nyquist theorem, the highest spatial frequency that an image sensor can distinguish is equal to half of its spatial sampling frequency, which is called the Nyquist limit frequency. When the image sensor CCD and image sensor CMOS are used to capture the target image, when the sampling image exceeds the Nyquist limit frequency of the system, the high-frequency harmonics in the image sensor will cause a moiré effect wi...

AI Technical Summary

Problems solved by technology

After changing the substrate from a blue glass substrate to a blue plastic substrate, the thinner blue plastic substrate can have a sufficiently steep transmission-cutoff transition region, but there are two new problems on the whole: the blue plastic substrate does not It is easy to deform after being thin and the adhesion between the blue plastic substrate and the optical film needs to be further improved. If these two new problems are properly solved, the optical filter can not only reduce the price, reduce the volume and weight, but also because of the use of Optical filters made of blue plastic have thinner thicknesses and reduced aberrations resulting in better image quality than optical filters made of blue glass

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