Color filter is a key material in modern display technology, especially in the field of liquid crystal display (LCD). It filters white light into three basic pigment dot matrices of red, green and blue through a specific process, thereby realizing color display. This article will explore in depth the principle, production process and wide application of color filter in various fields.
Principle of color filter
The core principle of color filter is to achieve color screening based on the different absorption and transmission of light of different wavelengths by the material. When white light passes through the color filter, only light of a specific wavelength can pass through, while other wavelengths of light are absorbed or reflected. This color screening process makes the object present the corresponding color. Specifically, the color filter is composed of a color filter film composed of three basic colors of red, green and blue, which is regularly distributed on a glass substrate. Using the principle of filtering, these three colors are mixed to produce a variety of colors according to the different control voltages of the driver IC.
Production process of color filter
The production process of color filter mainly includes pigment dispersion method, dyeing method, printing method and electrodeposition method. Among them, the pigment dispersion method has become the mainstream method for preparing color filters internationally due to its high precision and good light and heat resistance. In the production process, the black matrix (BM) is first produced to determine the pattern of pixels and sub-pixels. The function of the black matrix is to separate the three color layers of red, green, and blue to increase contrast and avoid the generation of stray light. Then, red, green, and blue color filter films are coated on the glass substrate through processes such as the pigment dispersion method. Finally, a protective layer is made and a layer of indium tin oxide (ITO) is sputtered as a transparent conductive film layer to improve light transmittance and reduce surface resistance.
Application of color filters
1.Display technology: In LCD display screens, color filters are key materials. They achieve various color display effects by guiding red, green and blue light waves to the corresponding pixels on the screen. With the continuous development of LCD technology, color filters are also developing towards high brightness, high contrast, high color saturation and high resolution.
Color filters are also used in other flat panel display products such as OLED to provide colorful pictures for display devices.
2.Automotive industry: In the automotive industry, color filters are widely used in headlights, taillights and roof sunroofs. They not only add a beautiful and fashionable appearance to the vehicle, but also adjust the spectrum of the headlights, enhance the brightness, clarity and contrast of the headlight harness, and improve the safety of night driving.
3.Biomedicine: In the field of biomedicine, color filters are a safe, environmentally friendly and efficient optical component. It can play a variety of roles such as polarization, reflection and light transmission, providing good support for medical diagnosis, treatment and research. For example, in fluorescence imaging and fluorescence spectroscopy analysis, color filters can help doctors accurately diagnose tumors and other diseases.
4.Photography and film: In the field of photography, color filters can be used to enhance the expressiveness of specific colors. For example, when shooting yellow flowers, using yellow filters can make the image of yellow flowers more prominent.
5.In filmmaking, color filters are used to adjust the color and color temperature of the film to make the image more natural and vivid.
Other fields: Color filters are also used in eyewear design, such as reducing glare and adjusting eyewear coloring. They are widely used in sunglasses and sunglasses worn during outdoor sports.
6.In the fields of fluorescence detection, counterfeit banknote detection, food additive detection, etc., color filters can display the fluorescence reaction of substances, thereby realizing the detection and identification of substances.
As the core material of modern display technology, the principles and applications of color filters reflect the latest progress in optics and materials science. With the continuous development of technology, color filters will play an important role in more fields, bringing more convenience and innovation to human life and work.
