These new display types can have a significant impact on lighting requirements and workspace requirements. While these alternate table was provided. types of displays will be seen in the near future in 10 specialized applications, the CRT display will continue to be the most commonly encountered type in office settings through the 80s. The CRT type display will be the device referred to in this manual unless otherwise stated. The display on a VDT is generated by a beam which scans across the screen continuously in much the same manner as we read across a page. Each time this electron beam crosses the display area it regenerates the image on the display.
Electronic signals tell the beam when to light up certain areas of the screen.
The most common way of generating the characters on the display is to light up certain dots in a matrix to form the pattern of the different characters. Many home computers utilize a 5 x 7 matrix, while more expensive displays used with some business and personal computers are capable of generating 7 x 9, or 9 x 11 matrixes. Both the matrix size and the font style can have an impact on the quality and legibility of the display. These can in turn have an effect upon eyestrain. They may also appear to be out of focus.