| 摘要 |
PURPOSE:To detect the position of an object by a simple mechanism, by overlapping a part of single-directivity lights whose phases are mutually shifted by 90 deg., and seeking phase shift of irregular reflection from the object. CONSTITUTION:Intensely luminous diodes 11 and 12 of single directivity are attached onto a surface 13 at an angle of theta1. Respectively directed regions S1 and S2 are partly overlapped to form an overlapped region S3. By a phototransistor 14 whose pointing direction is a line of l1 running through those regions, irregular reflection from an object is detected. The diodes 11 and 12 are driven in rectangular waves whose phases are mutually shifted by 90 deg.. Light component by the diode 11 is large at a point of A1 on the line of l1, light components of the diodes 11 and 12 are mixed together at a point of A2, and light component of the diode 12 is large at a point of A3. And therefore, phase of the irregular reflection varies in accordance with the position of the object on the line of l1. It is possible, by doing so, to detect the position of the object. |
