Patent ID: 6438088
Filing Date: 2002-08-20
Classification: G11B

Abstract:
A light transmission device for transmitting a light beam with a variation of wavelength f from a light source to a light receiver, comprising,an optical element for receiving the light beam and projecting the light beam wherein a deflection angle between the received light beam and the projected light beam varies according to the variation of wavelength of the light beam, and a compensation optical element for receiving the light beam and projecting the light beam wherein a compensating deflection angle between the received light beam and the projected light beam varies according to the variation of wavelength of the light beam, wherein the optical element and the compensation optical element are arranged optically in series between the light source and the light receiver, the deflection angle changes in a first direction according to an increase of wavelength of the light beam, the compensating deflection angle changes in a second direction according to the increase of wavelength of the light beam, and the change of the deflection angle in the first direction is compensated by the change of the compensating deflection angle in the second direction so that a position on the light receiver at which position the light beam impinges is restrained from changing according to the increase of wavelength of the light beam.