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Basic Introduction of Infrared Thermal Imaging Lens

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Basic Introduction of Infrared Thermal Imaging Lens

Issue Time:2021-07-02

Infrared thermal imaging lenses can operate normally under extreme circumstances and harsh environments, and provide high-precision temperature detection. Both in terms of its own manufacturing process and working performance, it is better than ordinary lenses. The following is the basic introduction of infrared thermal imaging lenses.

An infrared thermal imaging lens is also a kind of optical lens. The infrared light emitted by the lens group converges to the image sensor (chip), and the photoelectric signal is converted by the chip. The final formation is composed of the thermal infrared difference between the object itself and the background. Thermal infrared image. In order to reduce the influence of the background noise signal, the smaller the F-number, the better. In extreme cold, extreme heat, or large temperature differences, changes in the curvature, thickness, refractive index, and lens barrel of the infrared lens will cause the lens to defocus. To ensure clear imaging, the lens needs to be refocused, which requires electric or manual operation. Focusing on, in order to eliminate the adverse effects of temperature changes, an athermal design is required. Different optical materials are usually used for optical compensation (temperature difference), or adopt a design with the opposite trend of mechanical materials and optical materials for optomechanical compensation.

The most used infrared lens is germanium crystal with a refractive index of 4.0, which is suitable for the 2-25μm band. This kind of crystal has a high refractive index and is only transparent to infrared light, but opaque to visible light and ultraviolet light, so animals and plants can be clearly observed without any visible light. Although the storage content in nature is not low, it is very difficult to extract high-concentration germanium. Because germanium often exists in other minerals in the form of isomorphism, it is difficult to form independent germanium deposits with independent mining values. It can only be comprehensively recovered and utilized in the process of beneficiation and smelting when the main metal deposit is mined. Therefore, price of infrared thermal imaging lenses is also more expensive than ordinary lenses.

Infrared thermal imaging lenses can generally be divided into two categories: medium-wave infrared thermal imaging lenses (MWIR lenses) and long-wave infrared thermal imaging lenses (LWIR lenses) according to the wavelength application window.

(1) The MWIR lens is suitable for scenes with high object temperatures. Its working wavelength mainly falls in the mid-wave infrared of 3.0-5.0μm. It has a strong ability to penetrate smoke and dust, high resolution, and excellent image quality. Usually used with medium wave refrigerated detectors, the diaphragm is placed behind the lens, so the lens and camera are bulky, but the detection distance is very long, such as a lens with a focal length of 150mm and 300mm, which can see a distance of 10 km-30 km. At the same time, it has the characteristics of good concealment and can work day and night, and is widely used in military and high-temperature measurement fields.

(2) The LWIR lens is suitable for scenes where the object temperature is low, and its working wavelength mainly falls on the long-wave infrared of 8.0-14μm, which can provide high-precision temperature measurement. It is usually used with long-wave uncooled detectors. Its lens design is commercial-oriented, lightweight and compact, and easy to maintain. It is widely used in electric power, chemical, fire, medical and other fields.

The infrared thermal imaging lens produced by Quanhom has achieved good results in many fields and can detect extremely small temperature differences in a variety of extreme climates. If you want to know more about infrared thermal imaging lenses after reading the above content, you can get a more comprehensive solution by contacting us.

As a professional manufacturer of Opto-electromechanical components, we are committed to providing customers with high-quality thermal infrared lenses (including LWIR, MWIR, SWIR). We continue to develop new technologies and can control the quality of our products in an all-round way. Our experienced management team can also provide thoughtful one-stop service according to customer needs. If you want to buy our infrared thermal imaging lens, please contact us immediately!