Patent ID: 7911654

Claim:
A method of estimating light output of a lamp in a scanner prior to the lamp being fully warmed-up, comprising: measuring a spectral characteristic of light emitted by the lamp at a time t 0 prior to the lamp being fully-warmed-up; determining a warm-up state of the lamp for time t 0 by comparing the spectral characteristic to stored data correlating the spectral characteristic and a lamp warm-up state; and estimating the light output of the lamp at a time t 1 , based on the spectral characteristic, wherein t 1 is greater than t 0 , and wherein estimating the light output of the lamp at the time t 1 comprises: determining a warm-up state of the lamp for time t 1 , based on the warm-up state for time t 0 and the difference between t 1 and t 0 ; and obtaining the estimated light output at time t 1 by comparing the warm-up state of the lamp for time t 1 to stored data correlating the lamp warm-up state for time t 1 and a corresponding light output.