High Optical Efficiency Illumination Device for Use in Image Reading

A high optical efficiency illumination device comprising:

• a light guide having a longitudinal axis, a transverse axis and a light entrance located at a first end of the longitudinal axis, the light guide further having a plurality of light reflective surfaces and opposing light exit surfaces located along the longitudinal axis for converting lights entering the light entrance into lights exiting through the light exit surfaces;
• an illumination means, comprising a plurality of light emitting elements of various light emission wavelength ranges and arranged near the first end of the longitudinal axis, for emitting light beams into the light guide through the light entrance;
• a mounting means, interposed between the illumination means and the light entrance, for locating and affixing the illumination means to the light entrance;
• and,
• for each of at least one of the light emitting elements, the mounting means further comprises a corresponding integrated lens structure for collecting and collimating the light emission emanated from said each light emitting element into the light entrance
• whereby maximize the optical efficiency of the illumination device defined, for each light emitting element, as the amount of light power exiting the light exit surfaces divided by the amount of light power emanated from said each light emitting element.