Color filtering disc with subwavelength grating structure and manufacturing method thereof

Abstract

The invention discloses a color filtering disc with subwavelength grating structure and a manufacturing method thereof. The filtering disc comprises a transparent base and tricolor pixel array positioned on the base and is characterized in that the tricolor pixel array is formed by a grating array which is formed by a medium layer and a metal layer; the metal layer is positioned outside the medium layer; the period of each grating corresponds to the color of the filtering light; the gratings with three types of periods are respectively used for filtering to red, green and blue in incident light. The manufacturing method comprises the following steps of: coating the medium layer and the metal layer on the transparent base in sequence and using the medium layer and the metal layer to form a concave-convex grating structure. The invention can obtain transmitted spectrum to three colors of red, green and blue by only needing to change the period of the gratings, thus reducing the difficulty for processing the color filtering disc; and the obtained filtering disc has proper transmitted spectrum, good color purity and high transmission for polarized light.

Description

technical field [0001] The invention relates to an optical element, in particular to a color filter with a sub-wavelength grating structure and a manufacturing method thereof, which can be applied to the field of backlight display. Background technique [0002] The reason why liquid crystal displays can present color images mainly depends on color filters. As a key component of liquid crystal display devices, color filters directly affect the contrast, brightness, viewing angle and even picture quality of the display. The performance requirements of liquid crystal display devices for color filters are as follows: (1) High color purity, that is to say, the transmission spectrum of the three primary colors of R, G, and B should be moderate, and the transmission wavelength range should not be too narrow, otherwise the light transmittance is too low ; The transmission wavelength range should not be too wide, otherwise the spectrum of the three primary colors will overlap, makin...

AI Technical Summary

Problems solved by technology

For example, the pigment dispersion method firstly disperses the pigment into the photosensitive resin, and repeats three times through photoresist coating, pre-baking, exposure, development, post-baking, etching, etc., and finally makes a color filter. The existing problems are: For the three colors of R, G, and B, there are differences in the thickness of the photoresist, and the surface of the formed three-color pixel is uneven, resulting in low color saturation of the image; the requirements for equipment are high, resulting in increased production costs; high performance requirements

However, how to sputter three metal layers with different heights on a 100-200nm structure and how to precisely control the height of the dielectric grating during the imprinting process have brought great difficulties to the actual processing of the filter

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