Printers

Part 2.

Another category of printers is non-impact printers. They operate on the same dot-forming principle as the dot-matrix printer; however, instead of using an impact mechanism, they use nozzles, heat, electricity, magnetism, or optical methods to transfer an image onto paper.

Inkjet printers form characters or graphics with a print head containing tiny nozzles or jets that spray drops of ink onto the paper. The effect is similar to dot-matrix printing.

While printing colour images, an inkjet printer uses a separate nozzle and ink cartridge for each of the three subtractive primary colours—cyan (dark blue), magenta, and yellow—plus a fourth for black, up to six different hues can be printed. The colour inkjet printer is an improvement over the problems of ribbons with multiple colour bands that are required for colour dot-matrix print­ers. Very expensive inkjet printers pro­duce high-quality colour, which is well suited for low-volume publishing, proof copies and overhead transparencies.

Other advantages of inkjet printers include quiet operation and high reliability, thanks mainly to fewer moving parts. A possible disadvan­tage is the problem of nozzleclogging.

A variation of the inkjet printer is called a bubble-jet printer. With bubble-jet technology, the printing element is a computer chip with miniature openings, each with its own heating element. By heating the ink and forcing it through the opening, a small bubble is created. The bubble makes a more precise mark on the paper with less scattering of ink droplets than a conventional inkjet printer. The result is a sharper image.

Laser printers create images with a laser beam scanning across an electri­cally charged drum. As in a copier, toner or ink with an opposite charge sticks to the drum and is then transferred to pa­per by pressure and heat to create the finished image.

Laser printers offer near-typeset-quality text, medium-resolution graphics ca­pabilities, and higher speed than con­ventional impact or non-impact printers. All can mix type styles and sizes as well as graphic images on the same page.

Laser printers are quite different from conventional printers. They contain their own built-in microprocessor and RAM and ROM memories in order to produce high print speed and resolu­tion.

A close cousin of the laser printer uses an array of light-emitting diodes (LEDs) instead of the beam of light emitted by a laser. LED printersfeature a simpler de­sign than laser printers, which translates into higher reliability and lower costs.

Page-descrip­tion languages. A difference among laser printers is whether characters are produced by us­ing selected patterns of dots, called bitmaps,or by using mathematical de­scriptions, called outlines. Printers that feature the latter use a page-descrip­tion language—a language that is used to describe output to a printer or display device.

The language includes commands for describing individual character shapes, drawing lines and polygons, and scaling(i.e., making an object appear larger or smaller). When you print on a printer that is equipped with a page description-language, the language takes care of the behind-the-scenes technical details. It constructs a program describing the pages and sends it to the printer. When the printer receives the program, it ex­ecutes the commands and produces the output. The result is more precise con­trol over the way each page is printed and improved quality of the output.

1.4 Give English equivalents:

Ряд контактних штирів, змінювати розмір і стиль літер, швидкісне друкування, принципи формування символів, крихітні сопла, картридж з тонером, основні кольори, різні відтінки, висока надійність, традиційний струменевий принтер, протилежний заряд, переносити на папір, пристрій друку сторінками, роздільна здатність від 300 до 600 точок на дюйм, нагрівальний елемент.

1.5 Fill in the blanks with the words from the text.

1. Dot-matrix printers use ____________ to print the dots required to shape a character.

2. Laser printers scan the image with ____________ and transfer it to paper with a special ink powder.

3. _______________ are used for engineering drawings and other technical illustrations.

4. Ink-jet printers form characters with ____________ containing tiny nozzles that spray drops of ink onto paper.

5. The most common type of ______________ is the dot-matrix printer.

6. Ink-jet printers are quieter than ______________ printers.

1.6 Put the verb into the correct form.

1. An ink-jet printer ______________ by projecting small ink droplets onto paper. (operate)

2. Images or characters ______________ by a selected pattern of dots. (produce)

3. Curves _______________ by linking a series of very short lines together. (draw)

4. Images _______________ by driving various combinations of pins against a ribbon and onto paper. (form)

3.6 a) Compare impact and non-impact printers. Talk about their: speed, memory, resolution,

service, price, noise. You can use the adjectives from the box.

fast slow high / low quality noisy quiet cheap expensive reliable sharp  

b)Now write a short text about the pros and cons of a printer or printers you use. Write about these aspects: type, speed, cost, noise, output quality.

c) Give information on the following types of printers: a thermal printer, a ball printer, a duplex printer, an electrostatic printer, a label printer, a local printer, a multifunction printer, a network printer.

1.8 Read the passage and choose the best answer to each question.

The quality of the graphics output on a computer printer is measured in dpi. Simply by changing the density of dots that make up each part of an image, the printer can produce graphics that looks almost photographic. To understand how this works, consider how a black-and-white photograph shows the shades which, in real life, are colours. Each colour is a different shade of grey. For graphics to be produced on the computer printer, a piece of software called a printer driver decides upon a dot of pattern which will represent each colour shade. These different patterns or textures create an individual effect which your eye translates into grey shade. The closer you look at the image, the less lifelike it looks.

1. 9 According to the passage, a computer printer can

(A) measure dots per inch

(B) change photographs

(C) look photographic

(B) produce pictures

2. Graphics are like black-and white photographs in that

(A) they are produced by computers

(B) a dot pattern is decided by printer driver

(C) each colour is seen as a different shade of grey

(D) they each create an individual effect

3.According to the passage, the graphics image

(A) is an exact reproduction of the photograph

(B) has the same quality as a photograph

(C) loses its natural look when viewed close-up

(E) changes the density of dots

2.0 Answer the questions.

2. What categories are printers classified into?

3. What type of copies (soft or hard) do printers produce?

4. What type of printers is the most popular today?

5. What are advantages of dot-matrix printers?

6. How does a dot-matrix printer operate?

7. What type of printers has fewer moving parts?

8. How does a laser printer create images?

9. What is a plotter used for?

10. How do laser printers differ from conventional printers?

2.1 Read and translate the following words and word-combinations.

Display technologies, liquid-filled display surface, ambient light, backlight, continuous surfaces, the intersection of a row and column, a grid of columns and rows, meet the needs, an electron beam, eyestrain and fatigue, flicker-free images, lack of clarity, increase, decrease, the inside phosphor-coated surface, overlap, a very narrow range of viewing angles.

2.2 Learn key words and word-combinations.

aliasing(n) – ступінчастість

cathode ray tube (CRT) – електронно-променева трубка

heat dissipation - тепловіддача

display adapter – адаптер дисплея

display screen – екран дисплея

dot pitch - розмір точки

grid(n) – сітка

high-end – потужний, професійний

liquid-crystal display (LCD) – дисплей на рідких кристалах

refresh rate – частота оновлення

resolution(n) – роздільна здатність

substrate (n) – підложка, основа

VGA (video graphic array) – відеографічний адаптер

video coprocessor – відео співпроцесор

2.3 Read and translate the text.

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