cathode" bulbs. 8. These (to differ) from standard fluorescent bulbs in that they have no filament. 9. They therefore (to operate) at much lower temperatures and, as a consequence, are more reliable. 10. Standard fluorescent bulbs (to be now found) primarily on low-cost units and older models.

IV. Put the words into the right order.

Xenon, has, bulbs, as, an, emerged, alternative, source, light

Xenon, full-spectrum, produces, light, a, very, stable, source Consume, cold, cathode, tubes, at, xenon, a, light, than, higher, sources, power,

rate

CCD, lenses, scanners, other, use, optical, prisms, and, components

A, use, high-quality, optics, high-quality, scanner, glass CCD, (charge-coupled device), the, type, is, sensor, used, in of, desktop scanners

V. Read and translate the text:

Text C

Colour scanners

Colour scanners have three light sources, one for each of red, green and blue primary. Some scanning heads contain a single fluorescent tube with three filtered CCDs, while others have three coloured tubes and a single CCD. The former produce the entire colour image in a single pass, the target being illuminated by the three rapidly changing lights, while the latter have to go back- and-forth three times.

Single-pass scanners have problems with the stability of light levels when they're being turned on and off rapidly. Older three-pass scanners used to suffer from registration problems along with being slow. More modern three-pass units are much improved and able to match some single-passers for speed. However, by the late 1990s most colour scanners were single-pass devices.

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These scanners use one of two methods for reading light values: beam splitter or coated CCDs. When a beam splitter is used, light passes through a prism and separates into the three primary scanning colours, which are each read by a different CCD. This is generally considered the best way to process reflected light, but to bring down costs many manufacturers use three CCDs, each of which is coated with a film so that it reads only one of the primary scanning colours from an unsplit beam. While technically not as accurate, this second method usually produces results that are difficult to distinguish from those of a scanner with a beam splitter.

VI. Fill in the blanks with a suitable word or word-combination: converts, is known, record, is, black and white, is measured, can, the more.

When a scanner … something into digital form, it looks at the image pixel by pixel and records what it sees. That part of the process … simple enough, but different scanners … different amounts of information about each pixel. How much information a given scanner records … … by its bit-depth.

The simplest kind of scanner only records black and white, and … sometimes … as a 1-bit scanner because each bit … only express two values, on and off. In order to see the many tones in between … … … , a scanner needs to be at least 4-bit (for up to 16 tones) or 8-bit (for up to 256 tones). The higher the scanner's bit-depth, … accurately it can describe what it sees when it looks at a given pixel. This, in turn, makes for a higher quality scan.

VII. Ask questions to which the following sentences would be the answers.

1. Most modern colour scanners are at least 24-bit. 2. They collect 8 bits of information about each of the primary scanning colours: red, blue, and green. 3. A 24-bit unit can theoretically capture over 16 million different colours, though in practice the number is usually quite smaller. 4. This is near-photographic

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quality, and is therefore commonly referred to as "true colour" scanning. 5. An increasing number of manufacturers are offering 30-bit and 36-bit scanners capable, so they claim, of producing better quality colour images. 6. Whilst the fact is that very few graphics software packages are capable of handling images with more than 24 bits, the additional bits are still worth having. 7. When a software program opens a 30-bit or 36-bit image, it can use the extra data to correct for noise in the scanning process and other problems that hurt the quality of the scan. 8. With more inherent information present in 30and 36-bit scanned images, users can more precisely alter image detail and RGB luminance values via the scanner's driver software.

VIII. Translate the text into English.

Key words: abbot, to plot (on), needle, photoelectric, to fix, rota(to)ry, selenium, drum, transistor, planchette, stepping motor, photodetector, commutator,

Text D

Сканер (зчитувач)

Історія

В1857 році флорентійський абат Джованні Казеллі (Giovanni Caselli) винайшов прилад для передачі зображення на відстань, названий згодом пантелеграф. Передана картинка наносилася на барабан струмопровідним чорнилом і зчитувалася за допомогою голки.

В1902 році, німецьким фізиком Артуром Корном (Arthur Korn) була запатентована технологія фотоелектричного сканування, що одержала згодом назву телефакс. Передане зображення закріплювалося на прозорому обертовому барабані, промінь світла від лампи, що переміщається уздовж осі барабана, проходив крізь оригінал і через розташовані на осі барабана призму й об'єктив попадав на селеновий

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фотоприймач. Ця технологія дотепер застосовується в барабанних сканерах.

Надалі, з розвитком напівпровідників, удосконалився фотоприймач, був винайдений планшетний спосіб сканування, але сам принцип оцифровки зображення залишається майже незмінним.

Принцип дії

Розглянемо принцип дії планшетних сканерів, як найпоширеніших моделей. Сканований об'єкт кладеться на скло планшета сканованою поверхнею вниз. Під склом розташовується рухома лампа, рух якої регулюється кроковим електродвигуном.

Світло, відбите від об'єкту, через систему дзеркал попадає на лінійку фотоприймачів ПЗЗ-лінійку або лінійку фотодіодів. Значення вихідних напруг лінійки фотоприймачів через комутатор подають на АЦП. Цифрові коди АЦ-перетворення передаються в комп'ютер. За кожен крок двигуна сканується смужка об'єкта, які потім поєднуються програмним забезпеченням у загальне зображення.

Unit 16

I. Read and translate the newspaper article. For question 1-5, choose the right answer A, B, C or D. explain the words in bold.

Text A

Citizens 2050

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Can you imagine what our lives will be like in the year 2050? Perhaps you will be flying off for a holiday on the moon, or maybe you will be taking your dog for a work in virtual reality. We recently carried out a survey of 1,000 people from different countries to find out what they think life will be like in the future. The results clearly demonstrate both our hopes and fears.

The survey suggests that friendship – one of the most important human relationships – will have changed dramatically. People will make friends through the Internet. What is more, a large number of people will even come across their future husbands and wives in this way! Computer will have become absolutely essential by 2050. Even now, some people describe them as their best friend! Others, however, say that we will become much more isolated from each other because we will have little real human contact.

Education will have changed a lot too. As more and more children will be using computers in schools, certain abilities, such as mental arithmetic, won’t be necessary since there will be computer programs for most calculations. Even writing by hand will have become a thing of the past.

According to the survey, home life will be better. Most people believe that by 2050 robots will be doing the housework and we will be eating ready-made food.

Space exploration will become increasingly popular. Fifty per cent of the people we talk to believe that man will regularly visit Mars. They also believe that travel on our own planet will probably change. Almost everyone thinks that there will be no cars in the city centres. Some even think that environmentally-friendly electric or solar-powered cars will have replaced the cars we use nowadays.

Pollution is something that seems to worry many people. Some fear that it will continue to get worse, and that our planet will become impossible to live on.

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Others even foresee that one day we’ll have to pay for clean air just like we do now for clean water.

On the other hand, people seem to be quite optimistic about the benefits of genetic engineering, as they think scientists will use it to cure diseases like cancer and AIDs. If scientists manage to find a cure for these, we’ll have a much healthier society.

Some people worry about the future, while others are full of hope and enthusiasm. No matter how dark or bright it may seem, it is up to us to look after our planet and try to make it a better place to live.

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