Patent ID: 6207968
Filing Date: 2001-03-27
Classification: G01T,H04N

Abstract:
A reading head for an optical scanning device, said reading head comprising:a housing having at least one bore for accommodating therein a respective photo-multiplier tube and a non-intersecting lateral bore for accommodating therein a stimulating light source for producing a stimulating beam having a first wavelength,a focusing lens mounted in association with the stimulating light source for focusing the stimulating beam on a film of the scanning device so as to produce stimulated fluorescent light having a second wavelength in said film at a point of contact by said stimulating beam,a window within the housing for mounting therein a filter for transmitting therethrough the stimulated fluorescent light whilst substantially blocking reflections of the stimulating beam,mounting means associated with said housing for mounting the housing in spaced relationship with said film so as to direct the stimulating light beam perpendicular to the film such that a distance from the film to an internal periphery of the lateral bore within the housing is equal to a focal length of the focusing lens, andregistration means within the housing for registering the stimulating light source within the lateral bore so that the focusing lens is in precise registration with said internal periphery.