| 摘要 |
PURPOSE:To attain stable angle detection even if dust or the like exists on a base by providing a picture processing section calculating the tilt of the base from the relative position of each cross point of a grating line. CONSTITUTION:A sensor control section 7 fetches a sensor signal (a) from a linear sensor 6 and sends a synchronizing signal (b) to a driving unit 4. The drive unit 4, according to the synchronizing signal (b), supplies a Y axis driving signal (c) to move the Y axis by a prescribed quantity in response to the resolution of a picture to an XY table 3. A signal from the linear sensor 6 passes a sensor control section 7 as the sensor signal (a), goes to a one line picture signal (d) of the base 1, converted into a binary by a binary picture memory circuit 8 and stored in a picture memory. Then the stored picture is inputted to a picture processing section 9 as a binary picture signal (e), where only the grating pattern such as a dicing line is extracted from the binary picture, the tilt is calculated and the tilt signal (f) is inputted to the drive unit 4. The drive unit 4 outputs a rotation drive signal (g) to drive a turntable 2 by a quantity in response to the tilt signal (f). |
