Sanders Associates Limited

Calcomp Inc.

Aftab H Kapadya

Charles Gunderson

James Lawrence

A control system for controlling a turret head in a pen plotter wherein the turret head and pen holder move in combination with the pen carriage to provide turret selectability at the writing site. Sensors and associated logic are provided for detecting the presence of a turret on the pen carriage, for sensing the presence and absence of pens in the turret and in the pen holder, for detecting the type of pen or other writing device being used and taking appropriate action responsive thereto, and for applying variable damping constants to the movement of the turret head. Control logic is disclosed for assuring reliable and optimum operation.

Pen turret control system

An improvement to graphics pen plotters including a pen gripping mechanism for gripping a cylindrical bodied pen in a generally vertical orientation for sensing the presence and type of a pen in the gripping mechanism with a single sensor. There is a multi-channel sensor adapted for producing and sensing a plurality, 'n+1', of parallel light beams disposed one above the other to produce a binary number at an output thereof indicating the ones of the light beams sensed by the sensor. The sensor is disposed to shine the light beams at a position past which the pen is moved by the gripping mechanism. There is also a cylindrical reflective surface disposed about a portion of the body of the pen so as to be struck by the light beams when the pen is being gripped by the gripping mechanism at the position and reflect the light beams back towards the sensor to be sensed thereby. The reflective surfce has 'n' cylindrical strip positions disposed to be struck by 'n' of the light beams for selectively containing non-reflective strips to indicate a binary indication of the pen type whereby one digit of the binary number output indicates the presence or absence of a pen at the position and the remaining 'n' digits of the binary number designate one of 2.sup.n possible pen types. Particular size relationships are disclosed providing preferred error-free operation in a low tolerance environment.

Plotter pen presence and type identification system

A pen type sensor for use in a graphics pen plotter wherein plotter pens are moved along a pre-established path between a pen holding area and a plotting area for reading a plurality of vertically oriented reflective indicia positions thereon to create a binary logic output signal representative of the pen type. There is a hollow body member having a pair of angled front surfaces. Light emitting apparatus is associated with one of the pair of angled front surfaces for directing a light beam to simultaneously strike the indicia positions at a point on the path of pen movement. A plurality of light detectors are associated with the other of the pair of angled front surfaces for receiving on respective sensing surfaces thereof the light beam as it is reflected by reflective indicia on a pen at respective ones of the positions and for creating respective bi-stable output signals reflecting the presence and absense of reflected light on the sensing surfaces. Finally, there is apparatus for reading the output signals from the detector means as the binary logic output signal as pens pass the point on the path.

Pen plotter pen type identification system

A control system for controlling a turret head in a pen plotter wherein the turret head and pen holder move in combination with the pen carriage to provide turret selectability at the writing site. Sensors and associated logic are provided for detecting the presence of a turret on the pen carriage, for sensing the presence and absence of pens in the turret and in the pen holder, for detecting the type of pen or other writing device being used and taking appropriate action responsive thereto, and for applying varible damping constants to the movement of the turret head. Control logic is disclosed for assuring reliable and optimum operation.

A pen for use in a graphics plotter employing a turret head with optical scanning of the pens. The upper portion of a cylindrical pen body having a centrally located guide ridge for positioning the pen in the gripping arms is provided with a retaining ridge, a support ridge, and a stop shoulder over which a sleeve is removably snap fit. The sleeve is provided with a reflective tape outer surface heat-bonded to the sleeve.

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Brea, CA, United States of America

Aftab H Kapadya