Abstract: A mask is described which enables the fabrication of features in GaAs such as waveguides, channels, facets, mesas, and mirrors by dry etch processing in chlorine containing ambients. The mask consists of an amorphous form of carbon which may contain incorporated hydrogen. The mask can be applied, patterned and removed through dry processing techniques.

Abstract: A single piece trigger and knock off mechanism for a switch operated card printer includes a lever integrally connected to a resilient mounting bracket which provides a first flexural pivot. The lever comprises a pair of integrally connected arms, each provided with an ear. A moving card contacts the ear on one arm, causing the lever to swing about the first flexural pivot. As the lever swings, the ear on the other arm contacts a switch which triggers a card printer solenoid. The solenoid operates a card printer hammer. The card printer hammer is driven towards the card when the solenoid is triggered. As the hammer is driven towards the card, a moveable element associated with the card printer strikes the arm whose ear is in contact with the switch, causing the arm to swing about a second flexural pivot formed by a bend in the arm. As the arm swings, the ear releases the switch. This knocks off the solenoid just before the hammer contacts the card.

Abstract: An apparatus for registering cards for printing in time recorders and the like uses a punch and die to form perforations which are co-linear with the printed information on the card. The perforations are sensed on subsequent insertions of the card and are used to prevent further insertion of the card and register the card in position so that each printing on the card will be made below previous printings.

Abstract: A printer countwheel mechanism in a time stamp machine keeps a running count of the number of groups of documents stamped by automatically advancing a countwheel to the next highest number when all documents in the group have been stamped. A document group comprises one or more documents. Each document in the group is stamped with the same countwheel number. When stamping single documents, i.e. groups consisting of only one document, the countwheel is advanced every stamping operation so that every document is stamped with a different number. When stamping duplicates, i.e. groups of two documents, the countwheel is advanced every other stamping operation so that duplicates are stamped with the same number. The mechanism may also be disengaged when it is not necessary to keep a count of the number of documents stamped.