Sampled Servo Read Only Memory System Using Single Carrier Independent Pit Edge Recording

Abstract

Single carrier independent pit edge recording (SCIPER) is a high-density optical disk recording method which stores information by modulating the position of pit edges in small discrete steps. A high-density read only memory (ROM) system for computer use is one possible application of SCIPER technology. This application requires fast access times and high recording densities, and hence we are developing a SCIPER system based on a red 680 nm laser and sampled servo techniques. We chose a SCIPER format with a linear recording density of 0.24 µm/bit and a track pitch of 1.0 µm. With this format and under optimal conditions we obtained tangential and radial skew margins of ±0.75° and ±0.7°, respectively, and found that the system can tolerate clock jitter values of up to 3.4 ns rms. By employing zone constant angular velocity (CAV) we expect to realize a 3.5-inch, 1.3-Gbyte ROM drive.