Abstract: Apparatus for separating a thermal transfer ribbon from a recording medium includes an elongated member which is positioned adjacent the ribbon and is movable to a position in contact with the ribbon for stripping the ribbon from the recording medium after a printing operation. The elongated member may take the shape and form of a blade or the member may be a wire for stripping the ribbon from the medium.

Abstract: A control system for a thermal print head includes means for regulating the firing of the print elements with the proper pulse width to compensate for increasing substrate temperature. The control circuit is divided into two separate circuits--the driving circuit for turning the print elements on and off, and the decision-making circuit which executes the substrate temperature coding and control codes and sends control signals to the driving circuit. Three types of temperature compensation are utilized in the control program. A tailored pulse width is used for each bank of the print elements to compensate for various element resistances. As the print head shuttles across the record medium, the pulse width is reduced for each horizontal dot position. The pulse width also is reduced for each line printed in the format. The system may be used for either direct thermal or thermal transfer printing with both full and half dot spacing and single or double width characters.

Abstract: A thermal printer has carriage means supporting a print head for travel along a platen and has camming means operably associated with the carriage means for providing a predetermined pressure of the print head against the platen in one direction of travel of the print head and for releasing or reducing such pressure in the other direction of travel.

Abstract: A cable connection mechanism for a thermal print head includes an integral carriage and clamp assembly which is formed to receive the leads of a flat cable and which contains the print head in position to engage the cable leads. Pressure required to maintain contact of the cable leads with the print head is provided by resilient means carried in a slot in the clamp assembly.

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: The level of ink in a reciprocating reservoir is automatically controlled for both printing and non-printing conditions. The reciprocating motion creates forces to cause the ink to move back and forth between the reciprocating reservoir and a main reservoir and a pump maintains the ink at one level during printing. The pump controls the direction and flow of ink moving between the reservoirs by continuous operation during printing and the ink is allowed to rise in the first-mentioned reservoir during non-printing.

Abstract: The ink fluid in a reservoir is heated to establish a temperature differential between the ink fluid therein and the ink flowing through a print head and being ejected therefrom in the form of ink droplets. The temperature differential in the ink tends to reduce or substantially eliminate any air or other type gas bubbles which may be present in the ink fluid at the lower temperature.