Abstract: A method is described for selectively reinking a resistive ribbon thermal transfer printing ribbon, comprising:(1) positioning a used resistive ribbon thermal transfer printing ribbon in a colloidal dispersion of electrophoretically depositable ink prepared(a) heating a water-insoluble polymeric binder having a melting point in the range of 85.degree. C. to 100.degree. C.

Abstract: A printer/copier having the added capabilities of scanning information from photocopying media, for the purpose of storing it in computer memories or transmitting it over communication lines. The printer/copier has a sensing electrode which detects the charge change on a photoconductor surface as it is being scanned by a laser beam. The laser can also be used to expose the photoconductor for the purpose of printing. A deconvolution circuit is also provided to convert the detected charge to a storable or transmittable coded signal.

Abstract: An ink jet printing head comprising a head body made from a material having high specific stiffness and the head body includes an ink passage which is kept small to retain the high body stiffness. The ink passage comprises a narrow slot connected with internal holes in the body which lead to ink inlet and exit ports. A nozzle plate having a plurality of orifices is fixed to the front of the head body and a piezoelectric crystal is fixed to the back of the head body. The piezoelectric crystal is kept thin compared to the head thickness, typically on the order of 1/20 to 1/30 of the body thickness, so that the effect of the crystal on the resonant characteristics of the assembly is kept small. The ink jet head provides a plurality of columns or jets of ink which are excited in such a way as to break up into uniformly and equally spaced drops at a fixed distance from the nozzle plate containing the orifices which produce the jets.

Abstract: In an ink jet nozzle per spot printer, the transit time of each stream is measured on a periodic basis. In response to the measured transit times, the time at which information imparting signals are applied to the respective charge electrodes is controlled. The transit time is measured (counted) in units of a drop cycle. The slowest count is detected, and the difference is taken between the transit time of the slowest stream and all other streams. In the instance when there is a transit time difference of zero between the slowest stream and a given stream, the printing signal is provided to the charge electrode without delay. In the instances when a transit time difference is detected, an information imparting signal is applied to the charge electrode with a delay dependent upon the sensed transit time difference. A data register has information signals stored therein which are indicative of the data to be printed. Such data will be printed during an appropriate portion of a data cycle.

Abstract: A charge electrode array for use in an ink jet printing apparatus is formed by anisotropic etching of apertures through a single crystal silicon substrate of (110) orientation. Conductive diffusion layers in the walls of and adjacent to the apertures permit a charge to be placed on a jet stream passing through the apertures. Contacts can be formed on the adjacent diffusion layers to provide connection to an externally located charging circuit or the contacts may be omitted when the charging circuit is formed in the substrate itself and connected by diffusion or a metal layer to each adjacent diffusion layer. Jet nozzles and synchronization electrodes are shown incorporated in the charge electrode array to form a monolithic structure capable of performing a plurality of functions. Substrate contacts are also provided for biasing.

Abstract: In an ink jet printing system, a single nozzle or an array of nozzles are etched in a semiconductor material such as silicon. Each nozzle has polygonal or N-sided entrance and exit apertures of different cross-sectional area. Preferably, the nozzle is in the shape of a truncated pyramid with the entrance and exit apertures being substantially square in cross-section. The corners of the apertures and wall interfaces may be rounded to reduce stress concentrations.

Abstract: A charging electrode array for droplets formed from a plurality of liquid streams is formed in a silicon substrate. The substrate also has an FET shift register and FET latch circuits formed therein to supply signals to the charging electrodes, which are formed by diffusing a dopant into at least a selected portion of the wall of each of a plurality of passages in the substrate.

Abstract: The practice of this disclosure obtains a monolithic structure useful for electrohydrodynamically synchronizing the formation of droplets in a jet stream exiting from a jet nozzle. The monolithic structure is primarily adaptable for ink jet printing. The jet nozzle structure provided by the practice of this disclosure includes a jet nozzle design in a crystalline semiconductor block, e.g., of silicon (Si), germanium (Ge) or gallium arsenide (GaAs), with an electrode structure which is integrally incorporated therewith whereby a variable electric field is established proximate to the orifice of the jet nozzle structure. The electric field electrohydrodynamically perturbs the jet stream emitting from the jet nozzle structure so that formation of drops in the jet stream is controllably achieved, e.g., synchronously when the variable electric field is oscillating with a given periodicity.