| 摘要 |
PROBLEM TO BE SOLVED: To provide methods of, in a lighting system, reducing the amount of retro-reflected light incident at a light sensing device, which senses the light energy of a light emitting device, and reducing measurement error of the light sensing device.SOLUTION: A light sensing device 202 supplies light energy from a light emitting device 110 along a first axis 220; and senses the light energy with the light sensing device disposed along a second axis 222 oriented substantially orthogonally to the first axis. The amount of retro-reflected light 260 from a work piece 26 at the light sensing device is reduced, and the light energy is adjusted in accordance with the sensed light energy.SELECTED DRAWING: Figure 2 |
