Patent ID: 7471395
Filing Date: 2008-12-30
Classification: G01M,G02B

Abstract:
1. An optical alignment method for a light-emitting module that includes a housing unit, a light-emitting unit disposed in the housing unit, and a lens unit, said optical alignment method comprising: (a) through image-capturing techniques, finding a light-emitting point of the light-emitting unit and a predetermined reference point, and determining a total optical path length between the light-emitting point and an imaging plane having a predetermined distance relation with the predetermined reference point; (b) finding an imaginary first center line located at a position that divides the total optical path length into equal half distances; (c) through image-capturing techniques, finding first and second edges of the lens unit that are opposite to each other in a direction of an optical path of light emitted by the light-emitting unit from the light-emitting point to the imaging plane, and determining a lens length between the first and second edges; (d) finding an imaginary second center line located at a position that divides the lens length into equal half distances; and (e) assembling the lens unit to the housing unit in such a manner that the imaginary second center line coincides with the imaginary first center line.