Abstract: Dual-sided direct thermal printing of a thermal imaging element having thermally sensitive coatings on opposite sides of a substrate is described, where the thermal imaging element is provided along a feed path of a thermal printer having print heads disposed on opposite sides of the feed path. Printing on both sides of the thermal imaging element is achieved by applying variable energy heat pulses from the opposed print heads.

Abstract: A data processing system comprising a central processing unit, a read-only memory, a changeable read-only memory and a read-write memory. A resident computer program is stored in the read-only memory, and instructions corresponding to program changes are stored in the changeable read-only memory. The program is assembled, revised and stored in the read-write memory from which the revised program can then be executed by the central processing unit. Other or further program revisions may be made by changing or reprogramming the changeable read-only memory.

Abstract: A gain control and signal conversion stage in a data converter for a color video CRT display system is disclosed. The disclosed circuit includes capacitors for supplying current at a selected output voltage level, voltage followers for charging the capacitors, and modulators for forming low-level analog color signals for control of video amplifiers in a color CRT display. Digital control of video brightness or contrast and precise color tracking are features which are discussed.

Abstract: A process for treating the interior surface area of a glass nozzle for use in an ink jet printer device. The process includes cleaning of the surface area with a hydrofluoric acid solution under controlled conditions, rinsing and then protecting the cleaned area with a blocking agent to prevent contamination by the atmosphere prior to use of the nozzle in a printer device. The disclosed process is useful in minimizing air bubble formation and lock within the nozzle during use, and in facilitating ejection or purging of such air bubbles as may become ingested by the nozzle during service.

Abstract: Described is a controlled device such as a printer device, comprising an electrically operated mechanism such as a moveable print head, a scanner for sensing indicia of alignment of the electrically operated mechanism, and an electrical conductor to carry signals by which the mechanism is operated. The electrical conductor is employed to provide the indicia of alignment to be read by the scanner. Included is a description of an electrical conductor which comprises parallel conductive runs made of copper which are spaced apart and supported by a transparent electrically insulative plastic material, thus forming a timing strip on which positional indicia are defined by optical contrast between the runs and the insulative plastic material.

Abstract: Described is a piezoelectric drive element assembly for use in ink jet printer devices. The assembly comprises a piezoelectric drive element, which is characterized by a pair of electrodes spaced apart and thereby electrically isolated from one another on an external lateral face of the drive element. The assembly further includes a printed circuit board having holes through which the drive element is fitted, with the electrodes of the drive element being soldered to opposite sides of the printed circuit board.

Abstract: The invention relates to a fastening mechanism (10) for removably securing together two workpieces, such as the mounting plate (50) of a print head housing (16) and the support blocks 12 of a carriage (10) in a line printer. The fastening mechanism has a locking member (22) having a stud portion (24) mounted on the carriage (10) for rotational and axial movement relative thereto and having abutment surfaces (28) cooperating with cam surfaces (56, 62) on the print head housing (16) upon rotation of the locking member (22) so as to latch together the print head housing (16) and carriage (10) by the action of a spring (38) biasing the locking member in an axial direction. The fastening mechanism enables a simple and rapid removal and mounting of the print head housing (16) to the carriage (10) without the use of any tools.

Abstract: A pin feed mechanism (10) for transporting continuous stationery (11) having perforations (46) at both longitudinal edges thereof, in which transport pins (38) are arranged to engage with the perforations (46) and move the stationery (11) past a printing station. The pins (38) each have a tapered end to facilitate insertion of the pins (38) into the perforations (46). The tapered end of each pin (38) is shaped to have biconvex cross section, so that the curvature of its paper engaging surfaces has a constant radius of curvature along the length of the pin (38).

Abstract: A memory system has a plurality of memory modules. A longitudinal parity word is stored in one memory module and correction words are stored in each of the other memory modules. When one of the data words in a memory module having a correction word is changed, the correction word is also changed from a prior value to a new value so that the longitudinal parity of the data in the modules is unaffected. The new value of the correction word is computed by EXCLUSIVE ORing the value of the data word before the change, the data word after the change, and the prior value of the correction word.

Abstract: A data processing system having a plurality of subsystems linked by a star coupler. The star coupler includes contention circuitry for controlling the star coupler so that at any given time no more than one selected subsystem can pass a message through the star coupler. The contention circuitry uses a conventional priority encode circuit to determine the selected one of the subsystems, so that the first message to be received from one of the subsystems is the message passed or, if two or more messages are received from subsystems simultaneously, the message from the subsystem having the highest relative priority established by the priority encode circuit is the message passed. In an embodiment showing an expanded star coupler, the contention circuitry has plural first level contention circuits and a second level contention circuit, each using a conventional priority encode circuit.

Abstract: A memory system having both a primary memory and an alternate memory. The alternate memory stores data to be substituted for data stored at memory locations in the primary memory that have defective cells. The alternate memory includes a byte memory and a bit memory. The byte memory stores bytes of data that are to replace bytes having multiple bit errors in the primary memory. The bit memory stores bits to replace single bits in any byte in the primary memory that has a single bit error. A mapping memory controls access to the primary memory and the alternate memory. The memory devices in the primary memory have either all row defects or all column defects in order to reduce the size of the mapping memory.