| 摘要 |
PURPOSE:To enable detection of two-dimensional displacement with a simple circuit by providing an image line sensor or the like which outputs pulses of different heights according to the brightness and darkness of light. CONSTITUTION:Bright parts and dark parts are differentially counted within 1/2 piece of n-pieces of photodiodes of an image line sensor 11 contained within one pattern of an optical mask and the values counted similarly within the next n/2 pieces are added to the count values in the case of a direction X and are subtracted therefrom in the case of a direction Y by which up-down counters 34, 35 for counting X- and Y displacements are changed over. The count values X0, Y0 of the counters 34, 35 are further doubled with respect to the change in the displacements DELTAX, DELTAY and are DELTAX=X0/4N, DELTAY=Y0/4N when the clock rates inputted to the counters 34, 35 are the same as the clock rates on the transmission side. |
