Abstract: A printer of small overall size includes a plurality of typing wheels on the periphery of which are provided letters characters or symbols. At a printing position, a selection mechanism selects one of the plurality of letters, characters or symbols on each typing wheel. A printing mechanism prints the letter, character or symbols selected by the selection mechanism by applying a pressure thereto. A mechanism for feeding recording paper is arranged after the printing device in the feeding direction of the recording paper, and the printing mechanism moves in a direction opposite to the feeding direction of the recording paper after which pressure is applied to the printing device to effect printing.

Abstract: A printer of the needle or hammer impact type prints by release of spring-stored energy, driving the needle or hammer against a platen or character ring. A rotating cam restores the printing member to a locked standby condition after impact, and an electromagnet attracts a moveable core to allow release of the printing member at selected times for printing. The gap between the moveable and fixed cores of the electromagnet is periodically closed mechanically and electrical energization of the electromagnet only maintains the attracted state of the fixed and moveable cores.

Abstract: A serial printer for use in portable electronic calculators and the like. The printer includes a single printing head having a plurality of characters divided into two groups circumferentially disposed therearound in a predetermined pattern. A first selecting mechanism selects one of the two groups of characters. A second selecting mechanism selects the particular character in the group selected by the first selecting mechanism which is to be printed on a printing tape. The first selecting mechanism may include a helical gear mechanism which selects between the two groups of characters.

Abstract: An improved wire dot print head assembly for a wire dot printer including a resilient securing spring for holding the assembly elements secure is provided. The print head assembly includes a plurality of print wires, each selectively driven through a print nose by a plurality of electromagnets disposed about the print wires. A pivotable operating member engaged to the input end of the wire is actuated by an electromagnet with the fulcrum end of the operating member secured by a holding member. The holding member, nose, electromagnet and operating member are compressively retained by the resilient securing spring. The holding member is formed with a projection extending through the fulcum portion of the operating member to minimize magnetic reluctance of the magnetic flux by minimizing an air gap between a plunger mounted on the operating member and a yoke plate. The print head constructed in accordance with the invention permits improved dimensional accuracy in a simplified construction.

Abstract: A rounded end on a pivoted arm impacts a print medium through an ink ribbon to form a printed dot on the print medium. For printing, a wire drawn by an electromagnet acts on the arm between the pivot axis and the rounded end. A plurality of arms and electromagnets are spaced apart along a lateral row and mounted on a carriage for reciprocal lateral translation over a distance approximating the space between arms to print an entire horizontal row of dots forming a portion of a character line. Arms are driven separately or in combinations. The gap in the electromagnet is simply fixed to reduce power requirements.

Abstract: Character rings mounted on a common shaft and having a plurality of circumferential character columns thereon, are opposed by a platen including recessed portions. A recessed portion faces non-printing character columns when the platen presses against one character column on each character ring for printing on paper. The platen translates laterally so that each character column on a character ring is printed in sequence. A single character selection and return mechanism serves all columns on a single character ring. A translating mask separates non-printing characters from the paper.

Abstract: An ink supply system for an ink printer. The system includes an ink cartridge which supplies ink through a conduit to the print head of the printer. A bubble trapping device is disposed along the conduit and includes a porous member which prevents air bubbles from entering the nozzle of the print head. The air bubbles are held in a chamber defined in the bubble trapping device. Fluid passages in the chamber of the bubble trapping device allow for continuous feeding of the ink to the porous member for passage to the nozzle. A bubble detecting device may also be provided in the supply system.

Abstract: A head for an ink-on-demand type ink jet printer includes two laterally offset, linear rows of ink nozzles, said nozzle rows being linearly offset for producing alternate dots of a continuous printed line of dots. Interconnected chambers and channels, formed in opposite surfaces of a central plate, are closed by coverplates to provide pressure chambers and nozzle ducts. Individual piezoelectric elements externally affixed to the coverplates in registry with the pressure chambers, when driven, locally deform the coverplate to drive ink from the associated nozzles. Ducts and chambers in one surface are not in registry with the ducts and chambers of the opposite surface, and the lateral offset between rows is less than the printed-character spacing.

Abstract: An ink jet printing head of simple construction includes two supply channels and a pressure chamber which are substantially coplanar with the nozzle. A piezoelectric element acts to decrease the pressure chamber volume and eject an ink droplet from the nozzle. A smoothly curved supply channel inlet assures that vapor in the pressure chamber is easily removed. Ink refills the pressure chamber from a transverse supply pipe feeding two supply channels when the chamber volume increases after ejection of a drop.

Abstract: A head for an ink-on-demand jet dot printer is highly integrated to provide a large plurality of closely spaced dots by combining more than one head of lesser dot density as components of a single unit. The dots from the separate component heads are interspaced on the print recording medium to provide characters of high quality. Commonality of elements provides for a miniaturized head. In another embodiment independent pressure chambers, channels and nozzles are formed on opposite sides of a common baseplate.

Abstract: A thermal printer for printing on a thermal print paper including a platen element of a porous material, a fibrous material or a plastic material having an inrregular surface is provided. The platen element is opposed to the printer heating element which generates thermal energy for printing on the thermal paper. The platen element is mounted in a pair of grooves in a holding member substantially parallel to the printing direction of the heating element and retained therein by an adhesive or compressive retaining members. The inlet and outlet edges of the platen element are rounded for facilitating paper transport thereby.The elasticity and deformity of the platen element permits intimate contact between the thermal head and the thermal paper for clearer printing with a smaller power input. Repetitive heating and cooling does not result in thermal stresses and extends the life of the thermal head.

Abstract: A printer for an electric cash register or the like which performs at least two print related functions. The printer includes a printing head adapted for lateral displacement across a printing paper for effecting printing on the paper. The printer also includes a drive mechanism for effecting the lateral displacement of the printing head and a paper feeding mechanism for advancing the printing paper. The printer may also include a stamping mechanism, an automatic receipt paper cutting mechanism and a journal paper winding mechanism. Each of these mechanisms includes a control lever for actuating the operation thereof. A displaceable selecting lever is arranged and constructed to selectively operate each of the control levers. A single electromagnet controls the operation of the selecting lever.

Abstract: A liquid ink for printers including a component for dissolving at least one of a fibrous material, sizing material and surface treatment material included in the recording medium is provided. An aqueous liquid ink in accordance with the invention includes a water-soluble dye, a strong alkali material, at least one wetting agent and water. The pH of the ink is between about 10 and 14. Shelf life of the liquid ink is improved by including a preservative and the speed of ink penetration into the print paper can be increased by including a surface active agent.

Abstract: An improved thermally sensitive printer for recording characters on a thermally sensitive medium is provided. An exothermic printing head includes a substrate and a plurality of selectively energized resistance elements supported on the substrate, the resistance elements being energized during a printing operation to print characters on a thermally sensitive medium in contact therewith. A rotary platen is provided for bringing the thermally sensitive medium into printing contact with the resistance printing elements to thereby effect printing on the thermally sensitive medium during a printing operation. The rotary platen is also adapted to incrementally advance the thermally sensitive printing medium after each printing operation.

Abstract: A character ring-selecting type printer for printing m laterally spaced columns includes less than m character rings with lateral spacing between adjacent character rings. The character rings are translated in unison to enable one character ring to print in more than one column.