This paper deals with the opto-mechanical configuration of a newly developed high-speed initializing system for phase change recording media such as CD-RW, DVD-RAM, and DVD-RW. The mechanical layout of the system that ensured the mechanical alignment of each diode laser to be field replaceable. With the unique optical configuration implemented, up to six field- replaceable high-power diode lasers of wavelength 840 nm can be simultaneously installed onto this newly developed system. When all six diode lasers were installed, the internal anamorphic optical system can project the near-field intensity distribution of the high power diode lasers into a large 180 micrometer by 3 micrometer spot size while maintaining enough initialization laser power and providing large depth of focus. In this operational configuration, the system is capable of converting the standard outer diameter of 120 mm phase change optical disk from its originally sputtered amorphous state to initialized crystalline state in less than 20 seconds, which is approximate 2 to 3 times faster than today's commercially available system.
Polaroid's Optical Engineering Department has developed an autofocus module designed for use with Polaroid's multi-laser print head. The print head and focus module are now being manufactured and sold as part of a high-quality laser printer for 14' X 17' medical diagnostic images. The focus module is mated and aligned to a cylinder that is clamped into a V on the print head to utilize the semi-kinematic methodology of the print head. The printer clamps the film onto an external drum that is spun at 3300 RPM. While being spun, the profile of the film is 350 μm peak to valley. The print head's focus tolerance is ± 5μm, which is a consequence of using binary film, laser diodes, and the required gray scale. A moving objective lens that tracks the film based on real-time focus information is needed. Polaroid has developed a new focus sensor and assembly process that is economical, reliable and simple. The new sensor can be assembled in 15 minutes and replaces a more complicated design.