Abstract: A thermal printer is provided which can operate at high speeds either as a direct thermal printer or a thermal transfer printer. The thermal printer includes a frame, a front door assembly pivotally connected to the frame and having a thermal head secured thereto. The front door assembly positions the thermal head to facilitate recording of information on a recording medium when the door is closed as well as dissipating heat generated by the thermal print head. A platen roller is positioned within the frame which conveys the recording medium between the thermal head and the platen roller. The thermal printer also provides interference shielding which maintains security of printed data. The thermal printer is also configured to allow operation in a rigorous environment.

Abstract: Apparatus for releasably attaching a daisy print wheel to a splined shaft of an angular drive such that the print wheel can be driven in angular rotation with substantially no backlash. The apparatus comprises a splined hub fixed to the print wheel and slidably engageable with the splined shaft and a holder mounted on the hub for movement between a locking position in which the hub is locked on the splined shaft with interference fit and a released position in which the hub with the holder thereon is slidably removable from the splined shaft together with the print wheel. The hub includes a plurality of angular segments of cantilever formation which are pressed into the spaces between the splines on the drive shaft with interference fit by the engagement of the holder in its locking position. The holder is axially movable on the hub in traveling between the locking and release positions and is not normally removable from the hub.

Abstract: A printer has a horizontally movable carrier which supports a print head including a print element on which are disposed type characters in a two dimensional array with the element controllably movable by motors in two degrees of freedom to selectively position each type character opposite a record-medium-carrying platen for printing. The print head is on a rocker having a cam follower which cooperates with a cam on a shaft driven by a variable speed motor which is also on the carrier. During printing the motor speed is controlled so that the print element is driven against the platen with a force related to the particular character being printed. The motor speed is further controlled so that there is not only a minimum wait between the printing of successive characters but there are also minimum accelerations and decelerations of the motor.

Abstract: A printer has a print shell on which are disposed type characters in a two dimensional array with the shell controllably movable in two degrees of freedom to selectively position each type character opposite a record-medium-carrying platen for printing. In addition, during printing the shell is driven against the platen with a force related to the particular character being printed, and associated with the printing is an indexing or transverse spacing of the print shell to expose new portions of the record medium for printing.

Abstract: A finger operated switching device includes a key assemblage having a key and a key magnet which moves relative to a biasing magnet wherein the magnets are so dimensioned and mutually positioned so that the key assemblage is biased to a retracted position and when the key assemblage is pushed to an extended position the force required first increases to a peak and then rapidly decreases.

Abstract: A capacitive switch includes: an electrical circuit formed by two spaced pads of conductive material on an insulative substrate; and a capacitive coupling member on the end of a keystem wherein the end of the keystem has a looped ribbon formed by two layers of insulating material sandwiching a layer of conductive material. As the keystem is urged toward the substrate a monotonically increasing area of the ribbon mechanically contacts the pads so that a monotonically increasing capacitive coupling is made between the two spaced pads.

Abstract: In a printer wherein a ribbon is driven against a platen by a print element there is provided a ribbon lifting mechanism having a one revolution motor which drives, via a n-to-1 reduction gear, a ribbon guide to pivot to different positions whereby different transverse portions of the ribbon are interposed between the impact region of the print element and the platen.

Abstract: In a system for recording bits in elements along a moving magnetic medium wherein a first valued bit is represented by a pulse of a first width, length or duration, and a second valued bit is represented by a pulse of a second width, length or duration, there is included the improvement of changing either the first width or said second width when the bit to be recorded and the bit previously recorded have the same value.

Abstract: There is disclosed a typewriter using a single element print head wherein the tilt and rotate positions for character selection are obtained by servo systems driving tilt and rotate shafts. The system utilizes a digital multiplexing system whereby common elements in the servo channels are time shared. One common element is a binary arithmetic unit which compares binarily represented actual and desired position values of the shafts to fetch from a memory desired velocity information. The fetched velocity information in binary form is compared with the binarily represented actual velocity of the shafts to generate signals for energizing the servo motors which drive the shafts.