Login| Sign Up| Help| Contact|

Patent Searching and Data

Document Type and Number:
Japanese Patent JPS6227689
Kind Code:

PURPOSE: To output a detecting signal when a measuring object is displaced to approach a reference position or to be spaced apart therefrom, by setting the reference position by appropriately selecting the resistance value of a variable resistor between a non-reversal amplifying circuit amplifying the output of a light receiving element and a reversal amplifying circuit.

CONSTITUTION: The beam spot on an object 3 to be measured by the laser beam from a beam emitting element is formed into an image on a beam receiving element 5 as a beam receiving point. This beam receiving point moves to a direction a'→b'→c' when the object 3 moves to a direction a→b→c. When the object 3 is present at the position (a), the relation of i1/i2=l1/l2 is formed between the output currents i1, i2 of the element 5 and the distances l1, l2 up to the beam receiving point. The current i1 is converted to voltage v1 by a non- reversal amplifying circuit A1 and the current i2 is converted to voltage -v2 by a reversal amplifying circuit A2. Therefore, the relation between the both terminal voltages v1, v2 of a variable resistor VR and the beam receiving point comes to v1, v2 of a variable resistor VR and the beam receiving point comes to v1/v2=l1/l2. When the resistance values from the circuits A1, A2 or the resistor VR to a slider 6 are set to R1, R2, by selecting the position of the slider 6 so as to form R1/R2=l1/l2, a detection signal can be outputted when the object 3 is spaced apart from the reference position (a) or approaches said position (a).

Application Number:
Publication Date:
February 05, 1987
Filing Date:
July 29, 1985
Export Citation:
Click for automatic bibliography generation   Help
International Classes:
G01S17/08; G01S17/02; H03K17/78; (IPC1-7): G01S17/08; H03K17/78