Extron Electronics Matrix 200 - Manual (Page 79)

Extron • Matrix 200 • User’s Manual
Appendix A • Part Numbers, Glossary and Troubleshooting
H or H/V – Horizontal (H) sync, or Horizontal and Vertical sync combined (H/V). On
connector panels, H identifies the connector for Horizontal Sync and H/V means
it is also used for combined, or “composite” Horizontal and Vertical Sync.
Hertz (Hz) – A measure of frequency in cycles per second.
High Impedance – (Hi Z or High Z) – In video, when the signal is not terminated locally and is going
to another destination where it will be terminated. In video, Hi Z is typically 10k
ohms or greater.
Horizontal Rate – (Horizontal Frequency) The number of complete horizontal lines, including trace
and retrace, scanned per second. Typically shown as a measure of kHz.
Horizontal Resolution – Smallest increment of a video picture in the horizontal plane is a scan line. The
number of scan lines is dependent upon the video bandwidth and is measured in
frequency. The number of lines it takes to scan an image onto the screen.
HSB – In color graphics, Hue-Saturation-Brightness. (Hue = the color, Saturation = the
amount of color, and Brightness = the amount of white).
Hue (Tint Control) – Red, yellow, blue, etc. are hues of color or types of color. Hue is the parameter
of color that allows us to distinguish between colors. The Hue, or Tint control
adjusts the amount of color displayed. Also see HSB.
Hz (Hertz) – Frequency in cycles per second.
Impedance (Z) – The opposition to (or load on) a signal. Circuits that generate audio or video
signals, are designed to work with a certain “load”, or impedance. Typical video
impedances: 75 ohm or High Z. Also see High Impedance and Low Impedance.
Interlaced – A picture is made up of two fields. Interlacing is the process whereby the lines of
one scanned field fall evenly between the lines of the preceding field.
K – An abbreviation for 1,000. A kilobyte is 1,000 bytes. In computer memory sizes,
the numbers are rounded down. e.g. 1k byte = 1024 bytes.
Kilohertz (kHz) – Thousands of Hertz, or a thousand cycles per second. For example, CGA’s
horizontal scan rate is 15.75 kHz or 15,750 hertz (Hz).
LCD – Liquid Crystal Display – A panel that utilizes two transparent sheets of polarizing
material with a liquid containing rod-shaped crystals between. When a current is
applied to specific pixel-like areas, those crystals align to create dark images.
LCD panels do not emit light but are often backlit or side-lit for better viewing.
LCD Projector – Utilizing the LCD technique, these projectors separate the red, green and blue
information to three different LCD panels. Since LCD panels do not produce
color, the appropriate colored light is then passed through each panel and
combined to exit through the projector lens and onto a viewing screen.
LED – Light-Emitting Diode – A low-power, long life, light source, usually red, green or
yellow in color. Some LEDs can produce two different colors.
Level Control – The Level Control on some interface products is similar to the Contrast Control
on a data monitor. It can increase or decrease the signal level, resulting in
greater or less contrast in the picture.
Low Impedance – The condition where the load has a less opposition to a signal. Low load
impedances can drag the signal down and may cause a fault condition.
Luminance – This is the signal that represents brightness in a video picture. Luminance is any
value between black and white. In mathematical equations, luminance is
abbreviated as “Y”. (See Chrominance.)
A-7