1. Flicker – мерегтіння;

2. Resonant – резонансний;

3. Beam – пучок;

4. Interlaced – переплетений;

5. Frame – рамка;

6. Persistence – постійність;

7. Coil – катушка.

2. Read and translate the following text.

In Europe, the USA and Japan, the race is on produce a new generation of television sets. These new sets will be larger than today’s models, possibly with 100-centimetre flat screens. Picture quality will be excellent, crisp and without flicker, as good as we are used to seeing in the cinema. Sounds quality too will be superb, thanks to digital multitrack transmissions. Such sets may be offering programmes in a choice of languages as they will be equipped with eight sound tracks.

Television works on a similar principle to radio concept that two signals have to be transmitted one for the sound and one for the vision. In the receiver these signals, which are close to each other in frequency, have to be amplified and separated.

The separator contains two resonant circuits, one tuned to the frequency of the sound carrier-wave. The sound signal is then dealt with in the same way a sound receiver. The picture is formed by making a beam of electrons move across the screen of a cathode ray tube, variation in the intensity of the beam causing areas of transmission- these are the number of lines that can be seen making up the picture. With interlaced scanning the whole screen is covered by the half number of lines in 1/50^th of a second-this is called a frame. The remaining lines fill the spaces between the first frame during a subsequent period of 1/50^th of a second, thus the whole process takes 1/25^th of a second. During this time the spot of light has covered the whole screen twice, but owing to the persistence of the fluorescent coating of the tube, the whole screen is illuminated. To obtain a proper picture, the movement of the electron beam in the receiver must be exactly synchronized with the electron beam in the television camera. This is achieved by transmitting synchronizing pulses with the vision signal.

The cathode ray tube (CRT) consists of an evacuated glass tube containing an electron gun (a heated cathode surrounded by a metal cylinder) producing a beam of electrons that fall on a fluorescent screen. Magnetic detection coils deflect the beam from side to side producing the lines, and another set of deflection coils give the up and down movement required by the frames.

The television camera consists of an optical lens used in a photographic camera, the image from which is projected into a camera tube. This consists of a photosensitive mosaic scanned by an electron beam. All are housed in an evacuated glass tube. The output signals of the camera tube are usually pre-amplified within the body of the camera.

Colour TV works on the same principle, the camera having three separated tubes, each sensitive to one of three colours red, green or blue. In the receiver the cathode ray tube has three electron guns; each one is controlled by the appropriate tube in the camera. The screen of the CRT is coated with a mosaic of different colour spots that fluoresce when electrons from a particular gun strike them; all the colours are made up from blends of the three colours.

3. Translate the following word-combinations and memorize them.

A new generation of TV sets, flat screen, picture quality, sounds quality, sound track, a beam of electrons, cathode ray tube, electron gun, photosensitive mosaic, camera tube, body of the camera.

4. Matching.

1. Match English words or phrases with their Ukrainian equivalents.

Sound signal Vision signal Circuit Interlaced Spot of light Optical lens Blend

Світлова пляма Змішування Відео сигнал Оптична лінза Звуковий сигнал Ланцюг Переплетений

2. Match words with their antonyms.

Radio Sound Separate Synchronize Output signal

Input signal Differ Television Vision Unite

5. Link each set of statements, using words or phrases of your own to make an explanation of how a tel-n picture is composed.

1. A television picture is built up gradually. This is done by a moving spot.

2. The spot strikes the television screen. The phosphor coating on the screen emits light. The light varies in brightness according to the intensity of the original image.

3. The spot reaches the right side of the screen. The spot is blanked. The spot is moved rapidly back to the left side in a movement called flyback.

4. The present European system sweeps the screen of lines. There are 625 closely-spaced lines. Using 625 lines ensure a good quality picture.

5. The movement across the screen is controlled by the line scan signal. The movement down is controlled by the field scan signal.

6. The scan rate must be greater than 40HZ. A lower scan rate would cause the screen flicker.

7. Sync pulses are added to the video signal. The sync pulses ensure that the TV camera and TV receiver start a new line and frame at the same time.

8. The built-up of the screen happens so quickly. The eye sees only a complete

picture.