II. Read and translate the text. Put all types of questions to the underlined sentences.

Text B

1. Liquid crystal displays

Liquid crystals were first discovered in the late 19th century by the Austrian botanist, Friedrich Reinitzer, and the term "liquid crystal" itself was coined shortly afterwards by German physicist, Otto Lehmann.

Liquid crystals are almost transparent substances, exhibiting the properties of both solid and liquid matter. Light passing through liquid crystals follows the alignment of the molecules that make them up - a property of solid matter. In the 1960s it was discovered that charging liquid crystals with electricity changed their molecular alignment, and consequently the way light passed through them; a property of liquids.

Since its advent in 1971 as a display medium, liquid crystal displays have moved into a variety of fields, including miniature televisions, digital still and video cameras and monitors and today many believe that the LCD is the most likely technology to replace the CRT monitor. The technology involved has been developed considerably since its inception, to the point where today's products no longer resemble the clumsy, monochrome devices of old. It has a head start over other flat screen technologies and an apparently unassailable position in notebook and handheld PCs where it is available in two forms:

low-cost, dual-scan twisted nematic (DSTN)

high image quality thin film transistor (TFT).

III. Read and translate the following sentences. Define the tense and voice of the Predicates.

1. LCD is a transmissive technology. 2. The display works by letting varying amounts of a fixed-intensity white backlight through an active filter. 3. The red, green and blue elements of a pixel are achieved through simple filtering of the white light. 4. Most liquid crystals are organic compounds consisting of long rod-like molecules which, in their natural state, arrange themselves with their long axes roughly parallel. 5. It is possible to precisely control the alignment of these molecules by flowing the liquid crystal along a finely grooved surface. 6. The alignment of the molecules follows the grooves, so if the grooves are exactly parallel, then the alignment of the molecules also becomes exactly parallel.

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

1. The first principle of an LCD consists of sandwiching liquid crystals between two finely grooved surfaces. 2. The grooves on one surface are perpendicular (at 90 degrees) to the grooves on the other. 3. The second principle of an LCD relies on the properties of polarising filters and light itself. 4. Natural light waves are orientated at random angles. 5. A polarising filter is simply a set of incredibly fine parallel lines. 6. A typical twisted nematic (TN) liquid crystal display consists of two polarising filters with their lines arranged perpendicular (at 90 degrees) to each other. 7. But in-between these polarisers are the twisted liquid crystals. 8. Therefore light is polarised by the first filter, twisted through 90 degrees by the liquid crystals, finally allowing it to completely pass through the second polarising filter. 9. When an electrical voltage is applied across the liquid crystal, the molecules realign vertically, allowing the light to pass through untwisted but to be blocked by the second polariser. 10. No voltage equals light passing through, while applied voltage equals no light emerging at the other end.