Abstract: A sheet or tractor media handling system for a compact printer having a housing, a cut-sheet supply station and a rotatable print platen constructed and located to feed top sheets from said supply station through a print path ingress past a print zone and out a print path egress. The system includes a mode control assembly for selectively controlling the movement of said supply station for sheet or tractor media; a pair of guide wheels constructed and mounted for engagement with tractor media along a tractor media inlet passage; bail rollers engaging the platen between the print path ingress and egress; and a variable spring system for urging the bail rollers against the print platen with higher or lower nip pressures for sheet or tractor media conditions.

Abstract: An improved catcher device for a continuous ink jet printer of the kind having a linear orifice array for producing a linear curtain of parallel drop streams. The catcher device includes: (i) an elongated impact surface constructed and located to be adjacent a region of the droplet curtain; (ii) a drop discharge channel located downstream from the drop impact surface; and (iii) a screen element across the mouth of the drop discharge channel.

Abstract: A sheet movement detection system for apparatus having a sheet feed path includes a first capacitor sensor including a first pair of parallel plate members located in opposing relation on opposite sides of the feed path plane at an upstream position and second capacitor sensor including a second pair of parallel plate members, which are correspondingly sized and spaced to said first plate members, in opposing relation on opposite sides of the feed path plane at a downstream position. The sensors are coupled in a detection circuit which applies potentials across the pairs of plate members so that output signals of the first and second sensing means are subtracted from one another. A position circuit detects the output of the detection circuit during movement of a sheet lead edge through the second sensor and provides a sheet lead-edge position signals indicating the position or velocity of the sheet lead edge.

Abstract: A portable printer comprises a lid member forming a portion of the printer top wall, when in a closed position. The lid member is latchable in a first open position to provide a view stand for print media. The lid member is movable to a second open position to prevent re-feed of continuous web material.

Abstract: An improved sheet-position detection system for apparatus having a sheet feed path and a use location(s). The position detection system includes a first capacitive sensor including a first pair of parallel plate members located in opposing relation on opposite sides of the feed path plane and centered on a desired lead sheet edge position. A second capacitive sensor includes a second pair of parallel plate members that are located in opposing relation on opposite sides of the feed plane and are centered on a desired trail sheet edge position. A bridge circuit applies potentials across the pairs of plate members in a circuit configuration such that output signals of the first and second sensors are subtracted, and when the combined outputs of the first and second sensors is zero, a feed sheet is indicated to be centered between the sensor means.

Abstract: An improved sheet separator and guide construction for a printer having a supply station and a feeder/platen for feeding a top sheet from a supported sheet stack and transporting it through the printing region. The construction includes a force plate for urging a supported sheet stack so that its top sheet contacts the feeder-platen and is moved toward a supply station egress region. A pair of sheet corner deflectors located respectively at opposite edges of the supply station egress region are constructed to direct sheet corners fed there-against inwardly toward the sheet center, and a central deflector located along a central portion of the egress region in spaced relation between the corner deflectors is constructed to direct the center lead-edge of a sheet fed there-against upwardly toward the printer top.

Abstract: Apparatus for clamping receiver sheets to the print drum of a thermal transfer printer. The apparatus includes a clamp assembly mounted for radial movement and having a clamp strip extending over the drum periphery and an interior longitudinal body coupled to that strip at a plurality of axially spaced locations. A longitudinal lever member extends axially within the drum from a pivot point at one drum end to an actuation arm at the other drum end and has a pivot arm coupled to a central portion of the clamp body. Springs urge the clamp assembly radially inwardly and an actuator mounted on the other drum end selectively moves the lever member radially outwardly.

Abstract: A drop ejection device for continuous ink jet printing includes a rectangular solid divided by parallel, elongated through-slots between its major surfaces, into a plurality of approximately identical dilatational regions. Each such region has a longitudinal mechanical resonance mode approximately the same as the desired drop ejection frequency. The body has an ink supply manifold adjacent a drop ejection face, which is normal to the longitudinal axis of the through-slots. An orifice plate having a linear orifice array, substantially longer than the through-slots, is attached to the ejection face. A plurality of elongated piezoelectric strips pairs are attached in opposing positions on major surfaces of each dilatational region. Upon actuation, said strips expand and contract to effect synchronous stimulation at the desired drop frequency.

Abstract: A multiplex drop ejection construction for a drop-on-demand, ink jet printer. The construction includes a support substrate; a first circuit portion having branches that include a resistive heater element and a diode device formed in spaced relation on the substrate. A dielectric passivation layer overlies the first circuit portion except at the discrete terminal regions of the first circuit portion branches. A second circuit portion comprising a plurality of multiplex electrode lines overlies the passivation layer and includes connection sections extending through the passivation layer into contact with terminal regions of the first circuit. A second passivation layer overlies the second circuit portion, but not the resistive heater elements.

Abstract: An electrooptic modulator having a electrooptic substrate and a transparent water impermeable layer formed on a surface of such substrate after absorbed water was removed from such substrate surface. This layer prevents adsorbed water from forming on the substrate surface which could cause the appearance of surface charge that would affect the operation of the modulator.

Abstract: A system for selectively shifting the phase of drop charging along the array of ink jets of a continuous ink jet printer by producing a replicate signal of the drop stimulation signal; selectively shifting the phase of the replicate signal to provide a phase control signal; synchronizing a media feed tachometer signal to the phase control signal to produce a print enable signal; and controlling address of the charge electrodes with the print enable signal. The system further includes a selection mode wherein drop charge phase can be made random by selecting synchronization with the media feed tachometer signal.

Abstract: An improved electro-optic modulator for a light valve device of the kind wherein the modulator is sandwiched between cross polarizer elements. The modulator includes a ferroelectric ceramic panel having a plurality of parallel grooves forming intervening parallel walled ridge portions. A series of address and reference electrode pairs are formed on the ridge side walls with each electrode pair being substantially parallel and opposingly centered on a normal across the intervening ridge portion. The electrode pairs of the series are staggered in location along respective ridge portions to define an array having a linear direction at about 45.degree. to the direction of the panel grooves. The panel can be oriented between the polarizer elements with the polarization directions of the elements parallel to and perpendicular to the linear direction of the array.

Abstract: A short detection system for a continuous ink jet printer includes an electrically conductive sensor element located along an ink egress passage of the printer's catcher; a dielectric surface formed along the drop impact region of the catcher, between the drop electrodes and the sensor element; and signal circuit responsive to a charge polarity reversal output by the sensor for signalling a charge electrode short condition.

Abstract: A process for fabricating a printed circuit board includes the steps of producing data in a printing-scan format representative of a designed area circuit pattern; with such data, printing a mask pattern, corresponding to said circuit pattern, on the metal surface of a dielectric substrate; and etching to remove unmasked portions of the metal layer.

Abstract: An improved nest device construction for use with insertable ink jet print/cartridges having detent portions accurately located vis a vis their orifice array. The construction includes a U-shaped member, having a handle and arms spaced to receive a print/cartridge, which is mounted on a printer carriage for rotation between insert and retain positions. The arms have interior pinch surfaces for slidably engaging an inserted print/cartridge during rotation of said member and a bottom lip edge that extends inwardly to initially support a print/cartridge in an insert position. A spring is located between the arms of the member to contact the bottom rear surface of an inserted print/cartridge and tilt its front face into engagement with a positioning knife edge.

Abstract: An improved heater construction for an ink jet printer of the kind having a rotary print platen for holding and transporting a print sheet through a print path. The platen heater includes a hollow shell mounted for rotation through the print path and has vacuum holes for sheet attachment. A heating foil is detachably mounted in heat transfer relation with a major portion of the interior periphery of said shell and is coupled by brush contacts to an electrical power source.

Abstract: An improved orifice plate for use in ink jet printing, includes a first elongated lamina composed of electroformed metal or metal-alloy having tensile or compressive stress condition and a second elongated lamina composed of a metal or metal-alloy electroformed onto said first lamina and having a counterbalancing stress condition.

Abstract: A method for avoiding drop charge switching errors in continuous ink jet printing of the kind using stimulation to regulate ink drop break-off of a linear array of ink streams. The method includes the steps of: controlling ink drop stimulation so that the phase distribution of drop break-off along the length of the ink stream array remains stable in time and charging stimulated drop streams in at least two different groups during at least two different address periods which are offset in phase so that all drop streams are addressed during a drop break-off condition.

Abstract: A method of fabricating an orifice plate for ink jet printing includes the steps of: (i) providing a reusable mandrel having an electrically conductive bottom surface of an oxidizable metal such as aluminum and integral raised relief portions comprising an oxide of the metal (e.g. aluminum oxide) and (ii) electroforming metal onto said mandrel conductive surfaces to form an orifice plate.

Abstract: A method for fusing thermal transfer prints to avoid blister-type defects. The method includes in order, the steps of rapidly heating respective print image portions to a first temperature slightly below their respective components boiling temperature, maintaining respective print image portions at approximately the first temperature for a time period sufficient to allow significant evaporation from said print portions and, after such period, rapidly heating such significantly dried print portions to the desired fusing temperature, above the components boiling points.