THIN BACKLIGHT SYSTEM AND LIQUID CRYSTAL DISPLAY DEVICE USING SAME

摘要

A thin backlight system for deflecting the light beams from light-emitting units for emitting light beams of different main wavelengths and focusing the light beams on light-passing units arranged in predetermined positions.  The system includes the light-emitting units (1), the light-passing units (4), an imaging optical system (3) having the same lenses which are arrayed in the longitudinal and/or lateral direction in such a way as to correspond to the array pitch which is the product of the array pitch in the longitudinal and/or lateral direction of the light-passing units multiplied by the number of different main wavelengths, serving to focus the light beams from the light-emitting units (1) on the regions of the light-passing units (4) corresponding to the different main wavelengths, and disposed so as to be opposed to the light-focusing surfaces of the light-passing units(4), and an illuminating optical system (2) serving to deflect the light beams from the light-emitting units (1) by reflection by main wavelengths, make the light beams go substantially parallel to the direction of the normal to the light-passing units (4), and make the light beams strike the opposite surfaces of the lenses of the imaging optical system (3) to the light-passing units (4) and disposed in such a way as to be opposed to the light-emitting units (1) and the optical incident surface of the imaging optical system (3).