light pen

light pen,

an electrical device, resembling a pen, that may be used with a computer terminal to enter or modify information displayed on the screen.

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light,

n 1. the electromagnetic radiation of the wavelength and frequency that stimulate visual receptor cells in the retina to produce nerve impulses that are perceived as vision.
2. visible light ranges from 400 to 800 nm.

light box,

n See illuminator.

light, chemiluminescent,

n light produced by the conversion of chemical energy into light energy.

light fog,

n See film fault, fogged.

light leaks,

n.pl See film fault, dark.

light, operating,

n a light with a strong beam that may be directed for concentrated illumination of a part being operated on.

light pen,

n a pointerlike device available with some computer terminals. A light pen selects data displayed on the screen by being pointed at any desired item.

light touch,

n See touch, light.