Device of the kind in which the distance of an object from a defined surface is determined or adjusted by means of a bridge circuit

Claim 1

A DEVICE FOR PROVIDING AN OUTPUT VOLTAGE RESPONSIVE TO THE DISTANCE BETWEEN AN OBJECT AND A PREDETERMINED PLANE, SAID DEVICE COMPRISING ASOURCE OF POTENTIAL, A FIRST BRIDGE CIRUIT HAVING FIRST AND SECOND ADJACENT ARMS COMPRISING FIRST AND SECOND PHOTORESISTIVE MEANS RESPECTIVELY, A SECOND BRIDGE CIRCUIT HAVING THIRD AND FOURTH ADJACENT ARMS COMPRISING THIRD AND FOURTH PHOTORESISTIVE MEANS RESPECTIVELY, MEANS INTERCONNECTING ONE PAIR OF OPPOSITE JUNCTIONS OF SAID FIRST BRIDGE CIRCUIT AND ONE PAIR OF OPPOSITE JUNCTIONS OF SAID SECOND BRIDGE CIRCUITS, OPTICAL MEANS POSITIONED IN THE PATH OF LIGHT FROM SAID OBJECT TO PRODUCE AN IMAGE, MEANS FOR POSITIONING SAID FIRST AND SECOND PHOTORESISTIVE MEANS TO RECEIVE LIGHT DIRECTED TOWARD FIRST AND SECOND REGIONS RESPECTIVELY OF SAID IMAGE, MEANS RESPONSIVE TO THE POSITION OF SAID IMAGE WITH RESPECT TO SAID PLANE FOR DIRECTING PART OF SAID DIRECTED LIGHT TOWARD SAID THIRD AND FOURTH PHOTORESISTIVE MEANS, WHEREBY LIGHT FROM A GIVEN POINT ON SAID OBJECT IS INTERCEPTED ONLY BY SAID FIRST AND THIRD PHOTORESISTIVE MEANS WHEN SAID DISTANCE EXCEEDS A PREDETERMINED LENGTH AND LIGHT FROM SAID GIVEN POINT IS INTERCEPTED ONLY BY SAID FIRST AND FOURTH PHOTORESISTIVE MEANS WHEN SAID DISTANCE IS LESS THAN SAID PREDETERMINED LENGTH, MEANS CONNECTING SAID SAID BRIDGE CIRCUITS, AND OUTPUT MEANS CONNECTED TO THE OTHER OPPOSITE JUNCTIONS OF THE OTHER BRIDGE CIRCUIT.

Claim 2

A DEVICE FOR PROVIDING AN OUTPUT VOLTAGE RESPONSIVE TO THE DISTANCE BETWEEN AN OBJECT AND A PREDETERMINED PLANE, SAID DEVICE COMPRISING ASOURCE OF POTENTIAL, A FIRST BRIDGE CIRUIT HAVING FIRST AND SECOND ADJACENT ARMS COMPRISING FIRST AND SECOND PHOTORESISTIVE MEANS RESPECTIVELY, A SECOND BRIDGE CIRCUIT HAVING THIRD AND FOURTH ADJACENT ARMS COMPRISING THIRD AND FOURTH PHOTORESISTIVE MEANS RESPECTIVELY, MEANS INTERCONNECTING ONE PAIR OF OPPOSITE JUNCTIONS OF SAID FIRST BRIDGE CIRCUIT AND ONE PAIR OF OPPOSITE JUNCTIONS OF SAID SECOND BRIDGE CIRCUITS, OPTICAL MEANS POSITIONED IN THE PATH OF LIGHT FROM SAID OBJECT TO PRODUCE AN IMAGE, MEANS FOR POSITIONING SAID FIRST AND SECOND PHOTORESISTIVE MEANS TO RECEIVE LIGHT DIRECTED TOWARD FIRST AND SECOND REGIONS RESPECTIVELY OF SAID IMAGE, MEANS RESPONSIVE TO THE POSITION OF SAID IMAGE WITH RESPECT TO SAID PLANE FOR DIRECTING PART OF SAID DIRECTED LIGHT TOWARD SAID THIRD AND FOURTH PHOTORESISTIVE MEANS, WHEREBY LIGHT FROM A GIVEN POINT ON SAID OBJECT IS INTERCEPTED ONLY BY SAID FIRST AND THIRD PHOTORESISTIVE MEANS WHEN SAID DISTANCE EXCEEDS A PREDETERMINED LENGTH AND LIGHT FROM SAID GIVEN POINT IS INTERCEPTED ONLY BY SAID FIRST AND FOURTH PHOTORESISTIVE MEANS WHEN SAID DISTANCE IS LESS THAN SAID PREDETERMINED LENGTH, MEANS CONNECTING SAID SAID BRIDGE CIRCUITS, AND OUTPUT MEANS CONNECTED TO THE OTHER OPPOSITE JUNCTIONS OF THE OTHER BRIDGE CIRCUIT.