APPARATUS FOR EXPRESSING WRITING FLUID FROM A PLOTTING PEN

摘要

1402019 Recording apparatus GERBER SCIENTIFIC INSTRUMENT CO 3 Oct 1972 [17 Jan 1972] 45492/72 Heading G1J [Also in Division G3] Writing fluid is expressed on to a recording medium by forcing the fluid from the tip of a plotting pen by a pump, having a linear relationship between drive-shaft rotation and displacement, controlled to produce a flow-rate corresponding to the relative movement of pen and recording medium. As shown, the relative motion between a plotting pen 12, mounted on a head 50, and a drum 30, driving a recording medium, is effected by variable speed motors 40, 60 energized by D/A servo-controls 70, 72 responsive to command pulses from a computer 20. The movement of the pen on to the paper is effected by a solenoid 76 energized by a Z axis driver 74 in response to a command from the computer. The commanded relative velocity of the pen is derived by a circuit 94 responsive to the output of devices 90, 92 deriving axis rate values from the command pulse trains. The output of the circuit 94 through a servo-control 96 controls the energization of a motor 84, driving the pump through gearing 86, whereby the flow of ink to-the pen is maintained in correspondence with the pen velocity. Feedback to the servo-control 96 is derived from a tachogenerator 98.