| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve detection accuracy of the threshold current of a light-emitting element by using simple arithmetic processing. <P>SOLUTION: Driving current is detected when an amount of light emitted corresponding to a reference value Km is obtained, and four equilibrium points specified by the amount of light emitted and a driving current corresponding thereto are determined. Three characteristic lines represented by a primary approximate formula and passing through two out of four equilibrium points are detected. The driving current when the amount of light emitted goes zero is calculated as a zero driving current from the characteristic line, and an average value of zero driving currents obtained from three characteristic lines is set as an estimated threshold current Ith_adv1. <P>COPYRIGHT: (C)2012,JPO&INPIT |
