Development of integrated optical unit for large storage capacity floppy disk

A small integrated optical unit suitable for a large storage capacity flopp y disk drive is proposed. The optical unit is 6.8 mm wide, 3.3 mm deep, and 3.0 mm high. The distance between the laser diode and the focused beam on the disk is only 4.0 mm. The optical unit consists of two components, a len s unit and a laser-detector unit. In this optical unit, with the beam slant ing incident on the disk, the reflected beam takes another path. Thus, a di ffraction grating, a lens, and a deflector can be integrated into one compo nent. The optical unit allows wide disk tilting of up to 2.4 degrees.