Helical optical tape read/write system using at least one laser array

Abstract

An optical tape is helically passed over a cylindrical outer surface of a drum at a first speed to effect a substantial circumferential wrap thereof. A first write/read head with a writing laser array generates light beams that are directed along a first path through an optical rotator, and then via an optical arrangement on the drum onto a portion of the optical tape at a wrapping location of the drum to effect helical scanning of that portion of the optical tape. The optical rotator and the optical arrangement are rotated parallel to the first path at second and third rotational speeds, respectively, where the third speed is twice the second speed. This results in a dynamic imaging of the light beams from the first write/read head in closely spaced and parallel tracks to write binary data on the portion of the optical tape at the wrapping location using a passive focusing control. A linear array of binary data stored on tracks on the optical tape is read by the first write/read head transmitting an illumination beam via the optical rotator and the optical arrangement to illuminate a portion of the tape, and then detecting the linear array of binary data returned via a reflected light beam using a detector array. Multiple write/read heads with associated optical arrangements can use the same rotating optical rotator to concurrently write and read data at separate sections of the optical tape.