Colour Television
Найдите ответы на вопросы в тексте 1 1. What basic components does colour transmission contain? 2. Whai images does a monochrome receiver receive? 3. What images does a colou: receiver receive? 4. How many components does an optical system concentrate? 5. What are they? 6. What component changes the electron bean density?
Text I Colour television is the transmission and reception of images in full colour. The colour television system can produce programs both in colour on colour receivers and in black-and-white on monochrome receivers. Also, colour receivers receive monochrome pictures when they are being transmitted. Colour transmission contains two basic components — brightness information and colour information. Red, green, and blue are the colours that are chosen for colour television. Colour cameras. In a colour camera an optical system separates the red, green, and blue image components of a picture and concentrates these three components in separate but identical colour camera tubes. Thus, the output of one tube reacts to the red light image; another — to the green, and another — to the blue light image. Colour kinescope. In a monochrome kinescope a single electron gun produces an electron beam. The brightness is controlled by an electron grid, which changes the electron beam density. In a colour kinescope three electron guns produce three electron beams which are synchronized. The intensities of beam are controlled by the voltage corresponding to the green, red, and blue components respectively of the colour picture.
Найдите ответы на вопросы в тексте 2 1. Why can colour television signals be transmitted over the same distance as monochrome television signals? 2. Why does a colour television receiver require more servicing than a monochrome receiver? 3. Is it possible to convert a black-and-white receiver to receive colour broadcasts?
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