Imaging method and device for day and night dual-purpose lens without ir-cut switcher

Abstract

The invention relates to an imaging method and device for a day and night dual-purpose lens without an IR-Cut switcher. A filter film is coated on an optical light-transmitting element in front of the lens, in the middle of the lens, or behind the lens, or in front of the lens 1. An optical light-transmitting element with a filter film is added in the middle of the lens or behind the lens; the filter film is antireflective to light with a wavelength of 400nm-640nm and 840-970nm, and has an average transmittance greater than 98%, and the light with a wavelength of 670-800nm The light is cut off and the average transmittance is less than 0.4%; and a color correction unit with the function of separating and removing the infrared component signal in the image signal is added in the image signal processor connected to the image sensor. The method and device can completely solve the problem of the reddish image taken by the camera during the day without using the IR-Cut switcher, and truly realize the dual use of day and night, which can greatly reduce the size of the lens, reduce the manufacturing cost, and ensure the reliability of the lens to use.

Description

technical field [0001] The invention relates to the fields of security, home security, and home intelligence, in particular to a camera method and device for a day and night dual-purpose lens without an IR-Cut switcher. Background technique [0002] As we all know, traditional security cameras must be equipped with IR-CUT as standard to switch between day and night. During the day, use the infrared filter inside the IR-CUT to filter out the infrared component to achieve the true color of the image. When the light is poor, turn on the infrared light, remove the infrared filter inside the IR-CUT, and let the infrared component enter to improve the low-noise effect of the image. [0003] However, because the IR-CUT is usually driven by a magnetic valve or a motor, it not only increases the cost of the camera, but also its stability and reliability will gradually deteriorate with the increase of the number of uses, and it often occurs that it cannot be switched during night and...

AI Technical Summary

Problems solved by technology

But only using this filter, when there is sufficient sunlight outdoors, the intensity of infrared light is high, and the 840-860nm light that is allowed to pass through the filter is still causing the infrared sensing unit (IR component) in the imaging chip to generate If the signal is very strong, then in the daytime, when outdoors, the strong signal of the IR component will still have a very large impact on the image signal processing of the image captured by the camera, causing the image to be seriously reddish

In addition, the filter film used in this patent not only has a large number of layers and complex processing technology, but also uses commonly used high-refractive index dielectric material TiO2 (n=2.35@550nm) and low-refractive index dielectric material SiO2 (n=1.45@550nm) Prepare day and night dual-purpose bandpass filters. TiO2 materials are prone to oxygen loss during the evaporation deposition process, forming other low-valent oxide films, resulting in increased absorption, and long-term exposure of TiO2 films to ultraviolet radiation will cause short-wavelength waves less than 450nm Absorption increases, which will inevitably affect the long-term performance of the filter

[0007] To sum up, except for the IR-CUT technology, none of the above two existing technical solutions can solve the problem of reddish image captured by the camera.

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