Abstract: A developer apparatus (29) for use in an electrostatic reproduction apparatus includes a large reservoir of toner (34, 44). The toner is located in a supply chamber (39) and is metered to a developer roller chamber (35) from which it is carried by a developer roller (31) past a doctor blade (36) to a photoconductor drum (19) for image development. A toner metering roller (41) rotates with the developer roller (31) to provide a continuous supply of toner from the supply chamber (39) to the developer chamber (35). Once an equilibrium level (65) is reached, the toner metering roller (41) acts to remove toner (34) from the developer chamber (35) to the supply chamber (39) to insure proper operation of the developer roller (31).

Abstract: In an electrophotographic reproduction device, such as a copier or a printer, having a transfer station (17) whereat toner images are sequentially transferred from the surface of a moving photoconductor (10) to the adjacent surface of sheets of moving and spaced transfer material, such as paper, the transfer station is controlled in a manner to produce a substantially similar electrical effect on the photoconductor both when a sheet of transfer material resides in the transfer station intermediate the photoconductor and the transfer station, and when no sheet of transfer material is intermediate the photoconductor and the transfer station.

Abstract: A printing machine includes a charge neutralizing system for neutralizing static charge on sheets of material fed therethrough. The charge neutralizing system includes a grounded wire (47) located in proximity to the sheets for neutralizing charge on the sheets. The charge neutralizing system further includes a grounded conductive brush (81) mounted on a sheet deflector (61) so that one end of the brush (77) contacts sheets as they traverse a first sheet feed path (71) and the other end of the brush (79) contacts sheets are they are routed by the deflector to a second alternative sheet feed path (63). The grounded brush (81) further serves to decelerate the sheet as it exits the printing machine over the second sheet feed path (63).

Abstract: A serial impact printer 11 includes a frame 15 mounted drive motor 47 coupled to a print wheel 31 to effect rotation thereof. The print wheel 31 is mounted on a movable print carrier 29 which serially moves from print position to print position along the print line. The motor 47 is coupled to the wheel pulley 51 of the print wheel 31 through a belt 49 which is wrapped about two idler pulleys 57 and 59 located on a sub-carrier 61. The sub-carrier 61 moves one half the distance of the print carrier 29 so that during escapement motion of the print carrier 29, the belt 49 imparts no rotary motion to the wheel pulley 51 and hence to the print wheel 31. The print carrier 29 may be clamped by clamp 77 to the belt 49 to effect the return motion thereof. The motor 47 is also coupled through a clutch 127 to the line feed apparatus of the platen 23.

Abstract: A keyboard (61) includes plural keybar actuators (11) each including plural keys (19, 23, 27, 31) hingedly interconnected (25, 29, 33) and a sensing device (13). The keys of a keybar actuator are all actuated by a common finger (45) in touch typing and therefore are not jointly actuated. Depression of one key causes the keybar actuator (11) to pivot and the sensing device (13) indicates which key is depressed depending upon the amount of keybar actuator rotation. Alternate sensing devices include individual contact switches (79-81) associated with each key.

Abstract: A keyboard assembly (FIG. 1, 11) is constructed of first light transmission members (13) second light transmission members (15), a key actuation assembly (17) having a matrix of keybuttons (25), plural light source assembly (19) and plural sensor assembly (21). Each light source on assembly (19) is exclusively and sequentially energized causing its light to be transmitted through the first light transmission member (13) to be split up and deflected downwardly by the surfaces (43) and then rightwardly by the surfaces (45) to emanate through the surfaces (47) to enter the surfaces (49) of the second light transmission member. Actuation of a keybutton (25) causes its associated interrupter (29) to assume a light blocking position between the first light transmission member (13) and a second light transmission member (15). Light passing through the second light transmission member (15) to the sensor array indicates that none of the interrupters (29) have blocked the light path.

Abstract: A ribbon feed failure in a printer can cause serious problems, particularly for a printer that uses heat to cause selective ink transfers. Localized heat buildup may injure the printhead and, if allowed to continue, might injure other printer instrumentalities.According to the invention, it is recognized that for ribbons having a degree of electrical conductivity, a mechanical ribbon failure will almost always result in a detectable change of electrical properties. By monitoring the characteristics of an electrical circuit passing through a section of the ribbon around the print point and, preferably, also the printhead-ribbon interface, abnormal electrical parameter values that indicate ribbon failure may be detected to trigger a cessation of printer operation.

Abstract: An impact printer utilizes a single print hammer which is loaded with a selected type chip transferred from a rotatable carousel cartridge containing plural type chips. A single solenoid motor is energized to effect chip transfer, the loading of a spring to effect subsequent return of the chip to the cartridge, and the loading of an energy storage spring utilized to power the print hammer toward a platen. Completion of the chip transfer to the print hammer releases the print hammer to be powered by the storage spring until the solenoid motor is de-energized. The solenoid armature provides a reaction force to the storage spring only during solenoid energization. The duration of solenoid energization thus controls the impact force of the print hammer and is varied in accordance with the character area of the selected type chip and with the desired print density.

Abstract: A print hammer for a high speed impact printer using a movable type-face-carrier, e.g., a rotatable printwheel. The print hammer is designed to enable rotating the printwheel for character selection purposes during the return stroke of the print hammer from impact position back to its rest position. While the print hammer moves in a plane perpendicular to the printer platen, back to rest position, pivotal and cam means cooperate to lift the hook shaped hammer head up and over the printwheel, therefore continuously clearing the path of said rotatable printwheel.

Abstract: In an impact typewriter/printer using a daisy wheel typefont a stepper motor for rotating said daisy wheel for character selection purposes and microprocessor facilities for controlling said stepper motor, means are provided for generating tones signalling the occurrence of predetermined events to be brought to the attention of the typist. For that purpose, the microprocessor facilities are used to detect and identify the occurring event and then generate a tone of a predetermined frequency by moving said stepper motor back and forth at given rates whereby the daisy wheel typefont is made to vibrate the surrounding air fluid and generate the acoustical tone.

Abstract: A toner container includes a displaceable member located within the container and attached to one end of a flexible membrane utilized to seal the container closed. A bellows member also forms part of the container. Once the container is inserted into the copy machine in a sealed condition, operator initiated pressure upon an outer wall of the container causes the bellows member to collapse and further causes the displaceable member to move downward carrying with it the membrane member. As the membrane member is thus deflected, the seal of the membrane member to the toner container is broken allowing the contents of the container to escape into the copy machine. A safety mechanism is utilized with the container to prevent accidental operation of the displaceable member during shipment or handling.

Abstract: An automatic typefont loader is sequenced to change the printwheel typefont of a printer. An elongated rack supports plural picker holders along its length and is normally located beneath the platen of the printer. Typefonts to be exchanged are held by the picker holders. During an exchanging sequence, the typefont carrier which is positioned along the platen to effect printing at discrete printing positions is positioned to a discrete printing position adjacent an empty picker holder for a typefont unloading operation. The elongated rack is then elevated so that the empty picker holder contacts the typefont. The typefont is removed from its carrier by moving the typefont carrier perpendicular to its normal motion. The picker holder rack is then withdrawn and the now empty typefont carrier is positioned to a second discrete printing position adjacent a selected typefont located on a picker holder.

Abstract: An electronic switch keyboard for typewriters or office machines includes a multiple switch at selected key positions to provide two signal inputs to a utilization device. A first capacitor switch is actuated to provide a first signal upon initial key depression and a second contact switch, common to all selected key positions, is actuated to provide a second signal upon further key depression at the selected key positions. A ground plane forms a portion of the contact switch and further serves to reduce parasitic capacitance and to shield the capacitive switches from stray electrical noise occasioned by the contact switch or other electrical inputs. A dielectric material is used to accurately separate the ground plane from the capacitive switch and further serves as a force spreading device for the contact switch.

Abstract: A bounce dampening system reduces switch actuator bounce when the actuators are restored to their home position. Included are selection interposers, one of which is selectively driven to thereby effect motion of selection bails and corresponding switch actuators. A reverse interposer is simultaneously driven. A spring restores the reverse interposer after the actuation cycle thereby carrying the bails and switch actuators to their home position. The return spring and the mass of the reverse interposer prevents actuator bounce and insures a timely return of the actuators.

Abstract: In a printwheel type of printer using a selection stepper motor for driving the printwheel, means are provided for performing printwheel homing operation upon occurrence of predetermined events. Such an event, is detected and reported to microprocessor means which drive motion means for bringing the printer carriage assembly to a first extreme left position where a stop element fixed relative to the printwheel rotation is made to enter the path of another stop element attached to rotate with the printwheel. Subsequently, the selection stepper motor driving the printwheel is driven for a number of steps at least equal to one motor revolution to ensure reaching inhibition of the printwheel rotation by bringing the rotating stop element into contact with the relatively fixed stop element.

Abstract: A pulse generating device for speeding-up the rate of a pulse train from N to N+n wherein each of the pulses in the N+n pulse train is synchronized with the immediately preceding pulse in the original N pulse train. A count-up counter is reset upon each original pulse and counts up from zero, at frequency F/N+n, up to the following original pulse. A count-down counter is loaded with the contents of the count-up counter when the following original pulse occurs or when the output pulses occur with the exception of the last pulse in the interval when the time interval between said original pulses includes several generated output pulses, and is decremented at frequency F/M up to zero. A variable presettable counter provides the count-down counter with frequency F/M when each original pulse appears or when the output pulses appear with the exception of the last pulse in the interval when the time interval between the original pulses includes several output pulses.

Abstract: Two coaxially mounted spoked print wheels form a single printing element of a serial printer. Each wheel contains plural spokes having print characters thereon and a selected spoke is driven by a hammer to impact paper on a platen thereby effecting printing. Each wheel has a gap or window between two spokes of sufficient size to allow hammer or spoke entry. In operation, the window of one wheel and the selected spoke of the other wheel are rotated to the print position. The hammer is actuated to effect printing. The distance between the hammer and the selected spoke is maintained constant when shifting from wheel to wheel by shifting the wheel combination axially along its axis of rotation. The printing element is advanced relative to the platen and the platen is indexed to effect serial line printing. The two print wheels can readily be removed as a unit from the printer and replaced for type style interchangeability.

Abstract: A typewriter-printer includes a single element printing mechanism which is pivotable about the center line of the curved platen to an optimum print line viewing position. Printing can thus take place, for example, along a print line located below the center line of the curved platen or, in the alternative, above the platen center line in accordance with operator adjustment of the printing mechanism. The printing mechanism is mounted for printing motion and is further mounted for escapement motion with respect to the stationary platen.

Abstract: A printer, such as an ink jet printer, incorporates various hardware such as the ink supply tank, tubing, and ink drop gutter, as representative items, having components molded in the hardware which disinfect groups of micro-organisms which present problems, particularly in areas where ink has depleted. The techniques described lead to inactivation of vegetative bacteria and fungi and prevention of maturation of spores in those areas not in frequent control with the biocide component of the ink. Also mutant forms are prevented from developing in those areas where the biocide component concentration is below the effective lethal level.