초록 ▼

A light source assembly and method of providing illumination a target surface utilize a fluorescent material to generate composite "white" light from source light of a particular color, i.e., a particular wavelength. The light source assembly is optimally designed for use in scanning devices, such a

A light source assembly and method of providing illumination a target surface utilize a fluorescent material to generate composite "white" light from source light of a particular color, i.e., a particular wavelength. The light source assembly is optimally designed for use in scanning devices, such as flat-bed color scanners, in which linear illumination is necessary to capture images, graphics, and/or text from a target scanned surface. In the preferred embodiment, the light source assembly includes a Gallium Nitride (GaN) based light emitting diode (LED) that emits blue source light and a light transmitting rod lens. The light transmitting rod lens is preferably a solid transparent structure, designed to receive the blue source light through one end of the rod and transmit a composite "white" light from the entire length of the rod, providing the desired linear illumination. The rod lens includes two fluorescent strips and a non-fluorescent strip, located near the exterior surface of the rod. The two fluorescent strips operate to absorb the blue source light and to emit red light and green light, while the non-fluorescent strip reflects the blue source light. The emitted red and green light, along with the reflected blue light, form the composite light that provides the linear illumination on the target surface.

대표청구항 ▼

[ What is claimed is:] [1.] A light source assembly for scanning devices comprising:generating means for emitting light of a first center wavelength, said light of said first center wavelength being a first component of a composite light;an elongated structure having a first port on an exterior surf

[ What is claimed is:] [1.] A light source assembly for scanning devices comprising:generating means for emitting light of a first center wavelength, said light of said first center wavelength being a first component of a composite light;an elongated structure having a first port on an exterior surface, said first port being optically coupled to said generating means to receive said light of said first center wavelength from said generating means, said exterior surface defining an interior region of said elongated structure to provide a propagation conduit for said light of said first center wavelength, said elongated structure having a second port along a length of said elongated structure;a first fluorescent material operationally associated with said elongated structure, said fluorescent material being distributed generally along a length-wise direction of said elongated structure, said fluorescent material having a property to absorb said light of said first center wavelength and emit light of a second center wavelength, said light of said second center wavelength being a second component of said composite ligh; anda second fluorescent material located near said exterior surface of said elongated structure, said second fluorescent material being distributed generally parallel to said first fluorescent material, said second fluorescent material having a property to absorb said light of said first center wavelength and emit light of a third center wavelength, said light of said third center wavelength being a third component of said composite light, said composite light being a generally white light;wherein said second port of said elongated structure is positioned and oriented to simultaneously direct and focus said first, second and third components of said composite light away from said elongated structure and toward a target surface.