Blanking

Blanking is a state in which the laser beam is turned OFF while the mirrors are changing position during the creation of animations or text. Blanking is an ultra fast operation happening typically hundreds of times per second. New technology solid state lasers use direct electronic control of the laser source to provide the blanking. With gas lasers such as argon or krypton, this was not possible and the blanking would be carried out by use of a third galvanometer that would mechanically interrupt the beam. As new technology was developed, a Poly-Chromatic Acousto-Optic Modulator, or PCAOM was used, that allowed high-speed electronic blanking, intensity control and color selection of a multi-color laser beam.

Modulation

Most DPSS lasers used in laser projectors support modulation. Modulation has to do with blanking but is a slightly broader term. A DPSS laser will support either 'analog modulation' , 'TTL modulation' or both. Modulation is usually specified in terms of kHz. 2kHz can be considered low and 30kHz can be considered high. Manufacturers do not specify an exact relationship between this number and the behavior of the laser.

Analog modulation

An analog signal is used to control the intensity of the output beam. This signal is usually a voltage in the range of 0V to 5V. With an RGB laser and analog modulation you have, with an 8 bit system, 16.7 million colours at your disposal.

TTL Modulation

TTL modulation indicates that the laser does not support analog modulation of the output but only ON / OFF control. See blanking. With an RGB laser and TTL blanking you have seven colours at your disposal. Red, Green, Blue, Cyan, Magenta, Yellow, White.

ILDA

The International Laser Display Association. A trade association dedicated to promoting the use of laser displays.

Scan Angle

This term defines the optical angle that can be achieved by a set of scanners normally at a given rate of points per second. The wider the angle the larger the area covered by the scan will be but the more difficult it will be for the scanner to accurately track due to physical limitations of the mechanical nature of a scanner. As an example a 20 degree angle will provide a 3.5 metre scanned area at a distance of 10 metres from scanner to screen. Scan angles can be easily calculated using standard trigonometry.