Patent ID: 6181417
Filing Date: 2001-01-30
Classification: G01J,G01N

Abstract:
A readhead for a spectrometer for illuminating a target area having a predetermined area and receiving light from the target area, said readhead comprising:a housing (16) adapted to be incorporated in a spectrometer;a first light-emitting diode (12) mounted in a fixed position relative to said housing (16), said first light-emitting diode (12) being adapted to emit a substantially monochromatic light beam having a first wavelength towards said target area, said light beam emitted by said first light-emitting diode (12) having a uniformity and a divergence angle;a second light-emitting diode (14) mounted in a fixed position relative to said housing (16), said second light-emitting diode (14) being adapted to emit substantially monochromatic light of a second wavelength towards said target area, said second wavelength being different than said first wavelength, said light beam emitted by said second light-emitting diode (14) having a uniformity and a divergence angle;a support mechanism (20) adapted to support a biological sample to be illuminated by one of said light-emitting diodes (12, 14);a substantially planar light-shaping plate (32) disposed between said first and second light-emitting diodes (12, 14) and said support mechanism (20), said light-shaping plate (32) being adapted to increase said uniformity of each of said light beams, to increase said divergence angle of each of said light beams, and to transmit greater than about 85 percent of the light emitted by said light-emitting diodes (12, 14) to said target area; anda photodetector (22) mounted in fixed position relative to said housing (16), said photodetector (22) being adapted to detect light from a biological sample disposed in said target area illuminated by one of said light-emitting diodes (12, 14).