1. Laser Display System Christopher Nigro David Merillat

2. Description / Overview (1) Produce a simple binary graphical display using a set of diode lasers. –Support text displays (stationary and scrolling) with the possibility of images and simple video. –Minimize lasers required for display. Should help minimize cost. –Provide enough accuracy and synchronization to ensure resulting image appears consistent with minimal jitter and flicker.

3. Description / Overview (2)

4. Display Specifications SpecificationValue Refresh Rate60 Hz ± 5 Hz Vertical Resolution16 pixels Vertical Height12.5 cm ± 0.5 cm Vertical Jitter< ½ pixel Horizontal Resolution100 pixels Horizontal Field of View90° ± 1° Horizontal Jitter< ½ pixel Optimal Projection Distance70 cm

5. Target Display Modes Target Deliverables –Basic Text Display Display basic 8-point text. –Scrolling Text Display Display scrolling 8-point text at a configurable speed. –Pause Display Pause displays between commands. Goal Deliverables –Binary Image Display Display ASCII-encoded binary images. –Binary Video Display Display animation, or correlated sets of ASCII-encoded binary images.

6. Analysis and Feasibility (1) Specification: 60Hz Display –Requires a 4-face mirror spinning at 900 RPM. –Thus, required laser operating frequency must be approximately 50 kHz. Specification: 16 x 100 Pixel Resolution –Frame Size: 200 Bytes –Required Bandwidth: 12 kB/s Expected Brightness Approximately 350 cd.

7. Analysis and Feasibility (2) Horizontal Accuracy –Requires electrical timing accuracy of approximately 40 us. –Mirror mounting accuracy (horizontal) is not important and can be compensated for in software. Vertical Accuracy –Requires vertical mirror mounting accuracy of approximately 0.5 degrees.

8. Other Technical Difficulties Mirror Mounting –Mirror faces not mounted on motor shaft’s axis of rotation. –Causes nonlinearities in laser reflection angles. Frame Construction –Many of the components in this system require accurate or precise mounting. Motor Speed Control –If a decent synchronous motor is not found, a speed control system must be implemented to keep mirror rotation speed consistent.

9. Project Status Current Activities –Acquiring Components System Microprocessor Acquired and Functional –Motorola MC68332 20 MHz Microprocessor Lasers, motor, and materials required for accurate construction and mounting of system components. –Subsystem Design Motor Control Output FIFO Control Output Driver Channel

10. Conclusion Questions? Comments? Suggestions?