Patent ID: 6773142
Filing Date: 2004-08-10
Classification: G02B

Abstract:
An illumination apparatus for projecting a line of light, comprising;a plurality of diode-lasers each thereof having an emitting-aperture and arranged in an elongated linear array thereof, said diode-lasers being spaced apart by a spacing defined as the distance between the centers of adjacent ones thereof; said linear diode-laser array having a slow axis parallel to the length direction thereof, and a fast axis perpendicular to said slow axis, light being emitted from each of said diode-lasers, from an emitting aperture thereof, as diverging rays in both said fast and slow axes, in a general direction of propagation mutually perpendicular to both said fast and slow axes; an optical system, said optical system including a first anamorphic lens, and a lens group including a second anamorphic lens and a spherical lens having positive optical power, said optical system having a longitudinal axis parallel to the propagation direction of light from said diode-lasers and having mutually perpendicular fast and slow axes corresponding to said fast and slow axes of said diode-lasers; said optical system further including one or more arrays of microlenses, said one or more arrays of microlenses providing two arrays of cylindrical refracting surfaces and being located between said first anamorphic lens and said lens group, said arrays of cylindrical refracting surfaces having a pitch defined as the distance between vertices of adjacent ones of said cylindrical surfaces, the pitch of said arrays of cylindrical refracting surfaces being different from the spacing between said diode-lasers and said cylindrical refracting surfaces being arranged such that each thereof receives rays from a plurality of said diode-lasers and such that rays leaving said one or more microlens arrays arrive at said lens group as rays diverging in both said fast and slow axes; and said lens group being arranged to focus said fast-axis diverging rays from said one or more microlens arrays in a focal plane perpendicular to said longitudinal optical axis, and arranged to form said slow axis diverging rays from said one or more microlens arrays into a plurality of converging bundles of parallel rays each thereof including rays from a plurality of diode-lasers, said converging bundles of parallel rays intersecting in said focal plane, whereby light from said diode-lasers is formed into a line of light about in said focal plane, said line of light having a width in said fast axis and a length in said slow axis.