
| Glossary |
Lumen | A unit of measure of the flow, or rate of emission, |
| of light measured with a Light Meter. An |
| ordinary wax candle generates 13 lumens while a |
| |
Luminance | Abbreviated as "Y." The portion of the YPbPr |
| and |
| white information, which affects brightness. |
Noise | An undesirable electrical interference of a signal. |
Overscanning | Displaying less than the complete area of an |
| image to a viewer (i.e., scanning beyond the |
| visible area). All TV sets are overscanned at least |
| slightly, so that viewers do not see blanking. |
Raster | The area illuminated by the scan lines on a CRT. |
Resolution | The degree of sharpness of a displayed or printed |
| character or image. The amount of detail in a |
| picture. On a display screen, resolution is |
| expressed as the number of horizontal dots |
| (columns) by the number of vertical lines (rows). |
| For example, a 680 x 400 resolution means 680 |
| dots across each of 400 lines. |
Retrace | The |
| of a picture tube as it travels from the end of any |
| horizontal line to the beginning of either the next |
| horizontal line or field. The beam is turned "off" |
| during retrace. |
RGB (Red, Green, Blue) | Refers to the method of recording and generating |
| colors in a video system. On a television or color |
| monitor, colors are displayed as varying |
| intensities of red, green and blue dots. When red, |
| green and blue are all turned on high, white is |
| produced. When all dots are turned off, the base |
| color of the screen appears. |
| A high band video recording process for VHS that |
| increases picture quality and resolution capability. |
| |
| terminal that allows separate output of luminance |
| (Y) and chrominance (C) picture information to |
| monitors equipped with |
Model 250 Service Manual |