LCD color filter

LCD color filter

The white light emitted by the backlight of the liquid crystal display, and to obtain a color display, must rely on the key display material-color filters. A color filter is an optical filter that expresses colors. It can accurately select the small range of light waves to be passed, and reflect other undesired wavelengths. Color filters are usually installed in front of the light source so that the human eye can receive saturated light of a certain color. The structure of the color filter includes a glass substrate, a black matrix, a color layer, a protective film, and an ITO conductive film, and the structure of different types of Color Filters is also slightly different.

Color filter display principle

The R, G, and B primary colors of the Color Filter are arranged in a certain pattern and correspond to the TFT sub-pixels on the TFT substrate one-to-one. The white light emitted by the backlight becomes the corresponding R, G, and B color light after passing through the filter film. By adjusting the voltage value applied to each sub-pixel through the TFT array subject, the transmission intensity of each color light is changed, and the RGB color lights of different intensities are mixed together to realize color display. Depending on the purpose of the display and the video electrode, the arrangement of the RGB three pigments will also be different, mainly including mosaic, straight, triangular, four-pixel, etc.

Color filter production process and manufacturing method

The process of Color Filter is to make an anti-reflective light-shielding layer-Black matrix on a transparent glass substrate, and then make color filter films with the three primary colors of red, green and blue in order, and then filter the light A smooth protective layer (Over Coat) is coated on the layer, and finally a transparent ITO conductive film is sputtered.

The main core technologies in the manufacturing process of Color Filter include AlNd coating technology, a variety of optical film technologies, material film forming technology, cleaning technology, etc.

AINd coating technology-----AINd film is an important film layer for the production of reflective color filters. Its quality directly affects the performance of the color filter, mainly the appearance, surface quality and adhesion performance of the film.

Film thickness control technology-----In color filters, the thickness of each layer directly affects the chromaticity of the product, and in the production of color filters, each layer of film is made separately, and each layer The film reduction rate of the film is different, so the initial thickness control of each layer of film is very important.

Segment control technology-Color filters are mainly composed of red, green and blue film lines, and the deviation of the film thickness between them will cause the color deviation after color mixing.

Line width control technology-the line width of color filter products is directly affected by multiple processes, which is not easy to control and stable.