| 摘要 |
PURPOSE:To detect various patterns by detecting the position or shape of a pattern formed on a base body based upon an electric signal outputted from a photoelectric converter. CONSTITUTION:An irradiating optical system 10 and a reflecting optical system 11 are positioned so that the focuses F1, F2 of respective optical systems 10, 11 formed on the side of a laminated body 4 are positioned on their common point and a light shielding body 8 is positioned against the optical system 11 so that the focus F2' of the optical system 11 formed on the side of the photoe lectric converter 7 is positioned in its pin hole 8a. The laminated body 4 and a detector 12 are relatively moved so that the focuses F1, F2 of the optical systems 10, 1 scan the bottom e.g. of a groove to be a pattern 2 formed on the base body 1. When an electric signal whose level is sharply changed on the pattern edge of the base body 1 and almost held at a fixed value on the other position is inputted from the converter 7 to a processor 13, the position and shape of the pattern 2 of the base body 1 can be accurately detected. |
