| 摘要 |
PURPOSE:To identify the off-direction of a microsubstance by allowing an off- direction deciding circuit to output an off-direction deciding signal in accordance with the off-direction of the microsubstance immediately before the microsubstance is deviated from a micro-substance detecting area in either direction of positive and reveerse direction. CONSTITUTION:Pulse modulated light is projected from a light emitting element 2 by driving an oscillation circuit 9 to form a microsubstance detecting area through a projection lens and the pulse modulated light is made incident from the area to a light receiving element through an imaging lense. Diffracted light receiving elements 8a, 8b and a non-diffracted light receiving element 7 in the light receiving element respectively output currents corresponding to the quantity of incident light and the currents are converted into voltages to remove a DC disturbance light component. Respective processing such as amplification, filtring, rectification, and smoothing is applied to respective signals and the processed signals, i.e. diffracted light detecting signals Sa, Sb and a threshold level signal Sref, are inputted to a detecting area deviation deciding circuit 16 and a direction deciding circuit 17. |
