Infrared filter relevant contents.
1 Products used in the field of security monitoring and infrared gas analyzers.
Infrared filters are products used in the field of security monitoring and infrared gas analyzers.
This product is mainly used in the field of security monitoring, infrared gas analyzers, night vision products, infrared detectors, infrared receivers, infrared sensing, and infrared communication products. Specific products include surveillance cameras, remote controls, infrared curtain wall products, infrared sensing toilets, faucets, hand sanitizer devices, infrared thermometers, infrared printers, interactive electronic whiteboards, infrared touch screens, fingerprint recognition machines, facial recognition systems, etc.
CLASSIFICATION
From a material perspective, there are optical glass coatings, colored glass, and plastic infrared filters. This refers to near-infrared filters. If it involves mid to far infrared radiation and materials such as Si, ZnSe,Sapphire，CaF2, Quartz glass, etc.
From the perspective of optical characteristics, there are two types of filters: long pass IR filters and bandpass IR bandpass filters.
Among them, the long wave pass type,
(1) Made of colored glass, usually black, such as IPG-800. It absorbs visible light and allows infrared light to pass through. If you look at the sun through this infrared filter, you can still see a red sun. Suitable for infrared imaging.
(2) Infrared filters such as IPGC-720, also known as optical cold mirrors, are made by vacuum coating on optical white glass. They reflect visible light and allow infrared light to pass through. The appearance looks silver, like a mirror. If it is a mid to far infrared filter, it needs to be in Si, Sapphire， Coating on quartz glass.
2. Filter IR/Blue Glass BG
Infrared Ray Cut off Filter (IR Filter), also known as an infrared cut-off filter, is located between the lens and the sensor photosensitive element and is mainly used for filtering.
Because the visible light wavelength perceived by the human eye is 380-770nm, while the light wavelength range recognized by CMOS sensors is 350-1000nm, the sensor has a wider wavelength range and can receive infrared light, resulting in an overall transformation of the generated image that is different from what the human eye sees. After filtering, the image is closer to the human eye.
Blue Glass BG is an absorption filter. Unlike ordinary IR filters that are reflective, BG has better imaging effects, but the corresponding cost is also higher.
The ordinary surface IR filter is reflective, with low reflectivity in the visible light range and almost no effect. In the infrared range, the emissivity is high, resulting in halo phenomenon. And blue glass BG is an absorbing glass, without significant reflection.
On the other hand, ordinary IR will have a significant offset with the incident angle, while blue glass BG has a smaller offset and will not have problems such as uneven color, black angle, and red spots.
In the mobile phone market, Apple has been using blue glass BG filters since the iPhone 4, and many phones also use multi-layer coated blue glass filters to achieve better image quality.
The infrared band includes a wide range of wavelengths, from 780nm to 14um, which are further divided into near-infrared,
mid infrared, and far-infrared. There are three bands: near-infrared (code IR-A, wavelength 780-1500nm, NIR),
mid infrared (IR-B, 1500-6000nm, MIR), and far-infrared (IR-C, 6000-14000nm, FIR).
