PC controlled laser diode system application

This paper presents a system with personal computer (PC) controlled laser-diode beam to make film exposure for generating 256 gray-level images. The hardware equipment of this system includes an IBM-PC 8255 interface-card and an XY-table. A control software is developed to receive image data from a commercially available software such as PAINT SHOP, then convert them to signals for the laser diode and XY-table. The gray-level of each pixel in image file is represented by an 8-bit binary number. Two ways of control are demonstrated: 1) use this 8-bits number as parameters for timing delay when the laser diode is on with a constant power output; and 2) use this 8-bits number to go through a D/A converter to control the laser diode for outputting beams with varying intensity. Two potential applications for this system are given.