Position control system employing pulse producing means indicative of magnitude and direction of movement

Claim 1

APPARATUS FOR CONTROLLING THE POSITION OF AN ELEMENT CAPABLE OF MOVING IN AN X-Y PLANE HAVING AN X AXIS AND A Y AXIS, SAID APPARATUS INCLUDING: A MANUALLY ACTUATABLE CONTROL DEVICE SUPPORTED FOR ROTATIONAL MOVEMENT ABOUT AT LEAST FIRST AND SECOND ORTHOGONALLY RELATED AXES; FIRST MEANS NORMALLY ACTUATED TO RESPOND TO THE COMPONENT OF ROTATIONAL MOVEMENT OF SAID CONTROL DEVICE ABOUT SAID FIRST AXIS FOR MOVING SAID ELEMENT IN A RELATED MANNER WITH RESPECT TO SAID X AXIS; AND SECOND MEANS NORMALLY ACTUATED TO RESPOND TO THE COMPONENT OF ROTATIONAL MOVEMENT OF SAID CONTROL DEVICE ABOUT SAID SECOND AXIS FOR MOVING SAID ELEMENT IN A RELATED MANNER WITH RESPECT TO SAID Y AXIS; SAID FIRST MEANS INCLUDING A FIRST MEDIUM CARRYING A PLURALITY OF SPACED MARKERS THEREON; SAID SECOND MEANS INCLUDING A SECOND MEDIUM CARRYING A PLURALITY OF SPACED MARKERS THEREON; FIRST AND SECOND TRANSDUCER MEANS RESPECTIVELY POSITIONED PROXIMATE TO SAID FIRST AND SECOND MEDIUMS FOR COUNTING THE NUMBER AND DIRECTION OF MARKERS MOVING THEREPAST; MEANS RESPONSIVE TO SAID COMPONENT OF ROTATIONAL MOVEMENT ABOUT SAID FIRST AXIS FOR INTRODUCING RELATED MOVEMENT BETWEEN SAID FIRST MEDIUM AND SAID FIRST TRANSDUCER MEANS; AND MEANS RESPONSIVE TO SAID COMPONENT OF ROTATIONAL MOVEMENT ABOUT SAID SECOND AXIS FOR INTRODUCING RELATED MOVEMENT BETWEEN SAID SECOND MEDIUM AND SAID SECOND TRANSDUCER MEANS.