Patent ID: 6538976
Filing Date: 2003-03-25
Classification: G11B

Abstract:
An optical spot generation device (10) for a recording medium (34) having a light converging optical element (30) which receives light from a collimator (28) and forms an optical spot (M, E, F, G, H, I, J) on a track of the recording medium, and which can be displaced in a direction perpendicular to the track,wherein said collimator has a size which allows said light converging optical element to receive collimated light from said collimator in a whole motion range of said light converging optical element (30) and a length of said collimator in a track direction is shorter than a length in the direction perpendicular to the track, and wherein said collimator has a lateral cross sectional shape of oval, with its opposite ends in the track direction being cut straight.