| 摘要 |
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.
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