Scanners and Printers

Today, i'm writing facts and figures about computer peripherals, precisely about printers and scanners. It's really fascinating to know about the technology we use day to day.

1. A Page Description Language(PDL) is a language that enables applications to control HP Desk Jets, Laser Jets, and other HP printers.

2. Printer Control Language (PCL) is a language that enables applications to control HP Desk Jets, Laser Jets and other Hp printers.

3. The name Epson for the popular brand of printers was coined when the subsequent models of their first printer 'Electronic Printer 101' were called 'SOns of Electronic Printer'.

4. HP's first Inkjet printer was launched in 1984.

5. A Dichroic Mirror is an interference filter that reflects a specific part of the spectrum, transmiting the rest. It is used in scanners.

6. Airport scanners in the UK will soon be able to capture naked images of travellers, even underneath several layers of clothing.

7. When desktop scanners were first introduced, many manufactures used fluorosecent bulbs as light sources.

8. Before desktop scanners, colour pre-press companies used drum scanners, which were expensive and difficult to operate.

9. The inventor of the scanner is Robert S. Ledley, who patented the whole-body CT(computerised tomographic) diagnostic X-ray scanner. He was a professor of physiology and biophysics and of radiology, and he was the first to do medical imaging and three-dimensional reconstructions.

10. TWAIN is an image capture API ( Application-program Interface) for Microsoft Windows and Apple Macintosh operating Systems. The standard was first released in 1992, and is ratified at version 1.9 as of January 2000. TWAIN is typically used as an Interface between image processing software and a scanner or digital camera

11. A CD-RW disk can, in general, be re-written about a thousand times. In contrast, a hard disk can be written over virtually an unlimited number of times.

12. A flatbed scanner is designed for scanning prints and other flat artworks. Most have a glassbed or 'platen', on which the original is placed, on the top of a box containing a light source and photo sensitive receiver, usually a CCD (charge coupied device) array or a CIS( Compact Image Sensor), a single row of Photocells. Older scanners were often monochrome only, but now all are ' three colour' RGB devices using separate photocells to measure red,green and blue light.

13. George J. Laurer is considered the inventor of the UPC or Uniform Product Code, invented in 1973. The UPC symbol set for barcode recognition is sitll used in USA.

14. The firsr UPC scanner was installed at a Masrsh's Supermarket in Troy,Ohio, in June 1974.

15. The first patent for the bar code-US Patent #2612994- was issued to inventors Joseph Woodland and Bernard Silver on October 7, 1952.

16. Jacob Rabinow was the inventor fo the 'Reading Machine', an automated scanning and sorting appliance which scanned printed material and compared each character to set of standards in a matrix, using for the first time, the 'Best Match Principle' to determine the original message.

17. The simplest 3D scanners often use physical contact using highed arms. The depth is then calculated by measuring the orientation of the ranged object at the instant of contact.

18. Possibly the first known example of biometrics in practice was a form of finger printing being used in China in the 14th century as reported by explorer Joao de Barros of Portugal.

19. In the 1890s an anthropologist and police desk clerk in Paris named Alphonse Bertillion sought to fix the problem of identifying convicted criminals and turned biometrics into a distinct field of study. He developed a method of multiple body measurements, which got named after him-Bertillionage.

20. The modern fingerprinting technique, which was developed by Richard Eward Henry of Scotland Yard, essentially reverts to the same methods used by the Chinese for centuries.

21. When the CD was being invented, it was decided that a CD should be long enough to hold Beethoven's Ninth Symphony at any tempo-precisely 72 minutes.

22. EyeDentify, a Belgian company founded in 1976, developed The EyeDentification 7.5 personal identification unit, the first retina scan device made for commercial use, in 1984.