Overview

1. Laser Beam Galvo Y Amp/Driver Galvo Y Laser module Laser BJT Galvo Y Galvo PSU Galvo Y Amp/Driver BJT Switch Atmel AT91EB55 +X Amp Low-Pass Filter -X Amp Low-Pass Filter +Y Amp -Y Amp Josh Ibach-MacKeen Michael Ivey CMPE 490 DESIGN PROJECT 2010W VECTOR LASER PROJECTOR You may use any graphic design software to create your poster – but replicate this template if you do! Please note that PowerPoint may have difficulty printing colour gradations like the one in this balloon. Adobe Illustrator & Photoshop do not have this limitation. Overview • A laser projector is a device which uses a pair of rapidly oscillating mirrors to control the direction of a laser beam. The scanning of the mirrors combined with the modulation of the laser beam allows for the production of: • Vector images/animations • Visual effects Fig. 2 Laser projector component boards Image Properties The laser projector uses a custom software interpreter which translates images and animations complying to the International Laser Display Association’s (ILDA) standard file format to a form displayable by the laser. The projector is capable of drawing a maximum of 1024X1024 distinct points, and the “refresh rate” as such is entirely dependent on the number of points being drawn in an image. The projector is capable of emitting at a maximum viewing angle of 20o, but for complex images a smaller viewing angle such as 10o is required for improved image accuracy. Fig. 1 Block diagram of components Background Colour Design and Operation The laser projector employs a pair of galvanometers that take an analog input voltage to control the modulation of small mirrors, allowing for control of the laser beam in the X and Y axes. Each galvanometer takes a differential input of + 5 V. To control these galvanometers, a pair of XY coordinates is converted to an analog signal and transmitted over a pair of 10-bit Digital to Analog Converters (DACs) on the Atmel AT91EB55 Microcontroller. Each signal is passed through a noise filter to remove any unwanted noise before being passed on to the galvanometers. Since each DAC is only capable of a range of 0-2.5 V, these signals are correspondingly amplified in order to make full use of the projection angle of the galvanometers. This amplification process also produces the differential output signals needed to drive the galvanometers. The laser is modulated by a transistor switch which is connected to a GPIO pin on the Atmel board. Remember to acknowledge your project sponsor if applicable Figure numbers are not mandatory and depend very much on how you wish to convey graphical and tabular information Experiment with layout, form and colour to achieve a visually appealing and informative technical poster. Something that you would read! Please print the poster so its final dimensions are 21.75 x 31.25 inch Delete the side bubbles before printing! Don’t forget to spell cheque! Fig. 3 Sample vector image Department of Electrical and Computer Engineering