Thermal plotter

A thermal plotter comprising:

• a pair of electrically conductive elements spaced from each other and disposed along a first axis;
• a support assembly including a pivot rod supported for rotation about a pivot axis, and arms outwardly extending from the pivot rod and rotatable therewith;
• an electrical resistance wire extending between and supported by the outward ends of the support arms;
• said resistance wire being disposed at an acute angle to said first axis of said elements, and having a bridging portion in contact with the front edges of the elements;
• means coupled to the support assembly for causing rotation thereof about the pivot axis in response to an input condition;
• the movement of the resistance wire causing linear movement of the bridging portion of the wire along the front edges of said elements;
• means for providing a voltage across said elements to cause current flow through the bridging portion of the resistance wire and heating of the bridging portion to a temperature sufficient to cause activation of the thermally responsive sheet;
• and
• a thermally responsive sheet disposed in contact with the front edges of the elements and bridging portion of the resistance wire.

A thermal plotter comprising:

• a pair of electrically conductive elements spaced from each other and disposed along a first axis;
• an electrical resistance wire disposed at an acute angle to said first axis of said elements and having a bridging portion in contact with the front edges of the elements;
• means for supporting the resistance wire and electrically conductive elements with the resistance wire at an acute angle to said first axis and operative to provide relative movement between the wire and elements along a second axis transverse to the first axis, thereby to cause movement of the bridging portion of the wire along the front edges of said elements;
• means coupled to the support means for causing movement of the wire along the second axis in response to an input;
• means for providing a voltage across said elements;
• a thermally responsive sheet disposed in contact with the front edges of the elements;
• the bridging portion of the wire being heated by electrical current flowing therethrough to a temperature sufficient to produce a visible image on the sheet;
• the movement of the bridging portion of the wire along said elements being magnified in relation to movement of the wire along the second axis.