Low light level color image television system including electronic contrast enhancement system
First Claim
1. A low light level television system having a first channel which detects the nocturnal light reflected by objects in the visible spectrum and in the near infrared (400 nm to approximately 1000 nm) and a second channel which detects another part of the spectrum, each channel including a low light level picture pick-up or detector tube and an input lens adapted to the range of the detected wavelength, the sensitivity range of the first channel being determined by the sensitivity of the photocathode of the detector tube, the signals of the two channels being combined to produce an image on a television monitor, characterized in that the second channel also detects the light reflected from the objects in a wavelength range formed by the visible part (400 nm to approximately 700 nm) of the spectrum of the first channel, this sensitivity range of the second channel included in the sensitivity range of the first channel rendering it possible to improve the contrast and the noise of the image, the two tubes being positioned side-by-side so as to have the two images coincide and being provided with two electronic control and synchronous output circuits, the monitor being a colour television monitor, the first and second channels each acting on one of the colour input channels of the monitor to recover their information components via different combined colours in accordance with a single coloured image.
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Accused Products
Abstract
Low light level television system to detect the nocturnal light reflected from objects, comprising a main channel and acting on an extended range of wavelengths, provided with a low light level pick-up or detector tube, and a color channel, acting on a limited range of wavelengths, intended to bring forth the color for the formation of color images on a television monitor. The color channel includes an optical filter, which optical filter eliminates the infrared part of the reflected nocturnal light spectrum, a further low light level pick-up or detector tube, an electronic filter acting on the signal supplied by this further pick-up tube, the two tubes being placed side-by-side and being synchronized. The main and the color channels each act on a color channel of the monitor. The electronic filter provides a temporal integration over several fields. A processing circuit can combine the signals coming from the main and the color channels to act on a third color channel of the monitor.
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Citations
9 Claims
- 1. A low light level television system having a first channel which detects the nocturnal light reflected by objects in the visible spectrum and in the near infrared (400 nm to approximately 1000 nm) and a second channel which detects another part of the spectrum, each channel including a low light level picture pick-up or detector tube and an input lens adapted to the range of the detected wavelength, the sensitivity range of the first channel being determined by the sensitivity of the photocathode of the detector tube, the signals of the two channels being combined to produce an image on a television monitor, characterized in that the second channel also detects the light reflected from the objects in a wavelength range formed by the visible part (400 nm to approximately 700 nm) of the spectrum of the first channel, this sensitivity range of the second channel included in the sensitivity range of the first channel rendering it possible to improve the contrast and the noise of the image, the two tubes being positioned side-by-side so as to have the two images coincide and being provided with two electronic control and synchronous output circuits, the monitor being a colour television monitor, the first and second channels each acting on one of the colour input channels of the monitor to recover their information components via different combined colours in accordance with a single coloured image.
Specification