light pen

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light pen

Computing
a. a rodlike device which, when applied to the screen of a cathode-ray tube, can detect the time of passage of the illuminated spot across that point thus enabling a computer to determine the position on the screen being pointed at
b. a penlike device, used to read bar codes, that emits light and determines the intensity of that light as reflected from a small area of an adjacent surface

light pen

[′līt ‚pen]
(electronics)
A tiny photocell or photomultiplier, mounted with or without fiber or plastic light pipe in a pen-shaped housing; it is held against a cathode-ray screen to make measurements from the screen or to change the nature of the display.

light pen

(hardware)
An early pointing device which the user pointed at a raster-scanned display screen. A photocell in the pen detected the flying spot of the raster scan. The position of the spot at that instant, obtained from the scanning electronics, was made available to software as (x, y) co-ordinates.

light pen

A light-sensitive stylus wired to a video terminal used to draw pictures or select menu options. The user brings the pen to the desired point on screen and presses the pen button to make contact. Contrary to what it looks like, the pen does not shine light onto the screen; rather, the screen beams into the pen. Screen pixels are constantly being refreshed. When the user presses the button, the pen senses light, and the pixel being illuminated at that instant identifies the screen location.


Light Pen
Light pens provide a very precise pointing capability directly on the screen.








First Light Pen
This handmade prototype of a "light gun" in 1952 was part of the Whirlwind Project at MIT. Subsequent devices were used to hone in on suspicious blips on the CRT in the U.S. air defense system (see Whirlwind and SAGE). (Image courtesy of The MITRE Corporation Archives.)
References in periodicals archive ?
That is, after the start button is clicked on with a light pen, the target that replaces the word start may not be visible until the light pen moves away from that location.
The Age x Device interaction, displayed in Figure 2A, shows that using a light pen lessens age differences in performance as compared with a mouse even for this group of experienced mouse users.
To what extent are the age-related differences in performance with the light pen and mouse mediated by individual differences in basic abilities?
Each imaging system has a laser light pen, a lens, a filter, and a line array detector chip.
Visible light pens typically yield low read rates from poor quality symbols.
CCD scanners are less expensive than hand-held lasers but more costly than light pens.
The familiar light pen is a hand-held, contact reader.
DTI's light pens are available with unibody metal (stainless steel or anodized aluminum) cases with shielded cable (straight or coiled, optional armor cable is available), single, double or triple nosetip or barrel switches, zero-travel nosetips, and both internal ISA bus interfaces and external serial interfaces.
designs, manufactures and markets light pens for a variety of diverse applications including healthcare, dental management, automotive diagnostic and design, process control, point-of-sale, wafer fabrication in clean rooms, and gaming parlors and casinos for bingo and lottery ticket selection.
the world's leading supplier of light pen technology, today announced their agreement to deliver new products to market that incorporate handwriting recognition software and light pen hardware.
FTG's light pens are designed as a complement to mice and tablets, giving users a more intuitive way to draw, edit, point and select.
PenDirect for Macintosh offers the same direct, on-screen input as FTG's original PenDirect product but now includes a faster on-board processor, a more sensitive light pen and newer software.