Definition and classification of infrared cut-off filters

The infrared cut-off filters can effectively block the infrared light that interferes with the imaging quality and maintain high transmittance of visible light, making the resulting image more in line with the best feeling of the human eye

Infrared cut-off filter, also known as infrared filter or endothermic filter (IRCF), is a filter used to filter the infrared band. The infrared cut-off filter uses precision optical coating technology to alternately coat high and low refractive index optical films on optical substrates such as white glass, blue glass, or resin sheets. Due to the light entering λ After the mirror, visible and infrared light are refracted and imaged on different target surfaces, and infrared light forms a virtual image on the visible light imaging target surface, affecting the color and quality of the image. The infrared cutoff filter is an essential component for high-performance cameras, which can eliminate the impact of infrared light on imaging by effectively cutting off the near-infrared light region.

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The downstream end products of infrared cut-off filters currently do not have high requirements for image imaging quality and do not need to consider spatial filtering. Instead, they focus on light wave filtering (i.e. infrared light suppression). Infrared light suppression is one of the essential functions of image sensors. This is because CCD/CMOS has a different sensitivity to light compared to the human eye, where the human eye can only see visible light of 380-780mm, while CCD/CMOS can sense infrared and ultraviolet light, especially sensitive to infrared light. Therefore, It is necessary to use infrared cutoff filters to suppress infrared light and maintain high transmittance of visible light, making the CCD/CMOS sensing of light close to the human eye, so that the captured image also conforms to the eye’s sensing. Therefore, by adding infrared cutoff filters to the CCD/CMOS imaging system, this part of infrared light that interferes with imaging quality can be effectively blocked, making the resulting image more in line with the best feeling of the human eye.

The application fields of infrared cut-off filters include lens systems such as mobile phone cameras, computer cameras, and car mounted cameras. They can also be applied in fields such as QR code cameras, digital cameras, and monitoring systems that involve CDD/CMOS imaging systems, ultimately achieving the use of RCF to eliminate the impact of infrared light on CCD/CMOS imaging. In addition, terminal products can also improve imaging quality by filtering out infrared light, making its imaging more in line with the visual experience of the human eye.

Infrared cutoff filters are irreplaceable for downstream end products. In the future, the product structure of infrared cutoff filters will be further segmented with the improvement of downstream product performance. The requirements of the generation of CCD/CMOS systems for infrared cutoff filters are higher surface quality, more standardized specifications, and lower manufacturing costs.

In the downstream of the infrared stop filter industry, consumer electronics are the main application fields (such as digital cameras, digital video cameras, video surveillance cameras, etc.). With the continued rapid development of smart phones, car camera, security monitoring, smart home and other industries, the market demand for high-definition camera is strong, which greatly drives the market demand of IRCF


Hanzhong Brisun Optics Co., Ltd. Is the high precision optical element manufacturer provides customized production of Various optical lenses, including spherical lens, cylindrical lens, optical window, mirror, prism, filter, metal base mirror and other high-precision optical elements. The base materials include various optical glass, fused quartz, calcium fluoride (CaF2), zinc selenide (ZnSe), germanium (GE), silicon (SI), sapphire, metal and other materials. And provide antireflective film, high reflection film, spectroscopic film, metal film and other optical coatings.

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