| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To detect an impact position of a laser beam in a target plate without causing mixing of noise and a malfunction without using an optical filter. <P>SOLUTION: An electric current is generated on the basis of the impact position of the beam received by a PSD sensor 11, and an electric current is generated on the basis of the external light by a photodiode sensor 12. An electric current generated by the photodiode sensor 12, and amplified by an amplifying amplifier 13b is subtracted from an electric current generated by the PSD sensor 11, and amplified by an amplifying amplifier 13a in an attenuator 14, and an external light component is removed thereby. Afterwards, an impact position calculating means 16 detects the beam shot from a laser gun on the basis of a value of removing the external light component, and detects the impact position of the beam. <P>COPYRIGHT: (C)2004,JPO</p> |
