Thomas J Courtney

41603087, Jul 10, 1979

Apr 27, 1978

5/900685

Thomas Courtney - Redwood City CA
Vijay K. Lumba - Mountain View CA

Fairchild Camera and Instrument Corporation - Mountain View CA

B01J 1700

29588

An improved optically coupled isolator uses a glass layer in combination with layers of junction coat material between the emitter and detector to provide greater electrical isolation while preventing potential ionic contamination in the glass from reaching the detector and causing a deterioration in its operating characteristics. The isolator is assembled using standard semiconductor processing techniques so that the cost of manufacture is not substantially increased.

51161508, May 26, 1992

Jan 9, 1991

7/639585

Thomas P. Courtney - Santa Clara CA

Apple Computer, Inc. - Cupertino CA

A41J 2528

400320

The subject invention is an optical sensor detection system for a serial printer useful for the determination of alignment and misalignment of images on a sheet of print media and the correction of misalignment. The present invention includes a photoelectric sensor mounted on the carriage of a serial type printer to locate various indicator markings. In operation the sensor detects the position of a midpoint indicator when the carriage travels from right to left, and then from left to right. The positional information is then compared with the assumed mid-carriage position of the print head based upon the time of travel, that is, the predicted position of the sensor assuming no flex in the support members of the print head and no stretch of the belt driving the print head. The difference between the actual position and the assumed position is then used to derive a correction factor to the right to left and left to right printing parameters, and is used to compensate the timing of the placement of dots on the print media so that they are aligned in each pass.

51277522, Jul 7, 1992

Jan 9, 1991

7/639827

Thomas P. Courtney - Santa Clara CA

Apple Computer, Inc. - Cupertino CA

B41J 2102

400342

The subject invention comprises a printer system for a serial printer having an optical sensor detection system for the alignment of images on a sheet of print media, the correction of misalignment as a result of inaccurate alignment of the print media and the determination of the orientation of print media in a printer.

49251210, May 15, 1990

Apr 25, 1988

7/188111

Peter A. Tapscott - Portola Valley CA
Thomas P. Courtney - Sunnyvale CA

Xerox Corporation - Stamford CT

B65H 1712

242 57

An optical detector senses the teeth on a wheel rotating with an unwinding roll of medium in a printer and provides a signal which is used to count the sensed teeth to measure the rotation of the roll. When a predetermined proportion of a rotation is completed, the measured length of medium movement along a path through the printer during the predetermined proportion of a rotation is used to sense the condition of the medium. The conditions which may be sensed include amount of medium, medium thickness and medium malfunction. The circumference may, for example, be calculated and compared with a low medium circumference for the preselected or calculated thickness of the medium to detect a low medium condition. Periodically, the present medium position may be compared with its position when the last tooth was detected to sense a medium malfunction, either a medium out condition or a medium break. The teeth are triangular and shaped to provide a slowly varying signal from the optical detector which is converted to a purely digital signal by a high hysteresis Schmitt Trigger device.