Hewlett-packard Company

William J West

Edward T Liljenwall

Clarence K Studley

William W Misson

Bruce Cowger

Ross R Allen

Si-Ty Lam

Christopher A Schantz

Eric G Hanson

Howard H Taub

Robert R Beeson

Robert J Miller

The system for controlling the back pressure in the reservoir of an ink-jet pen includes a pump for removing air from the reservoir and a vacuum regulator to ensure that the back pressure within the reservoir does not exceed a level that would cause the print head to fail.

Back pressure control in ink-jet printing

A method and system for regulating the temperature of a hot melt ink wherein light reflected from a phase change material adjacent to the ink is detected, and a closed loop control signal proportional to the intensity of the reflected light is generated. The control signal is applied to a heater element for the ink and provides good temperature control thereof. In addition, the phase change material is used to generate an ink level indication signal which is also processed in a closed loop servo system in order to provide control over levels of the hot melt ink during operation of an ink jet printhead. In the embodiment of the present invention for controlling both ink temperature and ink levels within a pen body housing, there is provided a means and method for simultaneously sensing the liquid level and temperature at the solid/liquid interface within the pen body housing. This is done by simultaneously detecting the reflectivity of separate phase change material components located within or adjacent to the pen body housing and then processing closed loop detection signals which are optically coupled by way of control logic from the separate phase change material components to one or more heater elements located adjacent to the pen body housing. The present invention is also directed to a new and improved pen body construction which is uniquely suited for implementing the above novel method and system. This construction employs a flex circuit, an ink jet printhead and a multiple sensor assembly mounted adjacent to one wall of the pen body housing.

Method and system for remote-sensing ink temperature and melt-on-demand

An apparatus for a scanning-head printer in which a single motor is used to provide movement to a print head carriage and to advance the paper along a paper path. The single motor is coupled to the print head carriage to provide movement of the carriage back and forth across the width of the paper. As the carriage is moved across the paper, the print head applies print to the paper. An advancement mechanism is located near the edge of the paper path. As the print head carriage reaches the edge of the paper, the carriage contacts the advancement mechanism which, in turn, causes the paper to be advanced along the paper path. Thus, a single motor advances the paper and moves the carriage across the paper.

Single motor scanning-head printer

An apparatus and method for cooling a large-area, pass-through projection mask for excimer ablation. In a preferred embodiment, a laser-transparent window is spaced apart from the projection mask to provide a thermal escape path. The thermal escape path receives a liquid flow which is in direct contact with patterned masking material of the projection mask. The liquid, preferably deionized water, is caused to flow in a laminar fashion. The liquid intersects the laser energy of the excimer laser. In a second embodiment, the liquid flow is along the periphery of the patterned masking material.

Contact cooling of a projection mask

An orifice plate is thermally bonded to a thick film photopolymer spacer fabricated on a print head substrate using heat and compression. The compression is applied by pressurized gas to a pliable sheet covering the orifice plate and substrate assembly. Heat can be supplied through a vacuum chuck on which the assembly is mounted or from a heating element embedded in the pliable sheet. An apparatus comprising an air actuated ram with a flange having an o-ring seated within is used to seal the pliable sheet against the vacuum chuck circumferentially about the assembly. The ram includes a chamber with an open end which is sealed against the pliable sheet when in an engaged position. By filling the chamber with gas under sufficient pressure while heating the spacer forms a bond between the orifice plate and the assembly. After thermal bonding, curing of the photopolymer spacer can be completed in an oven.

Thermal-bonding process and apparatus

A push-button switch mechanism suitable for use with printed circuit boards is disclosed comprising a body that has a slidable plunger for actuating a cantilevered contact attached to the body. A button is attached to the plunger and when the button is depressed, the plunger deflects the cantilevered contact toward conductors on a printed circuit board to which the body is attached. A leaf spring in the body holds the plunger in an up or extended position and returns the plunger to this position after the button has been depressed. When the button is depressed the leaf spring is compressed along its longest axis and buckles, thereby providing tactile feedback. The switch may be provided with a light which is connected to the printed circuit board and is located in a cavity in the plunger. Illumination from the light may be seen through a translucent portion in the button.

Modular printed circuit board mountable push-button switch with tactile

A keyboard is disclosed comprising a printed circuit board having conductors on only one side. Resilient switching elements are supported by selected ones of the conductors and may be deflected into contact with other selected ones of the conductors by keys supported above the switching elements.

Printed circuit board and contact assembly for keyboard switch assemblies

An array of curved metal strips is supported over an array of conductors, and a key is supported over each intersection of a metal strip and a conductor. When a user depresses a key, a metal strip is pressed against a conductor to make an electrical connection. As the metal strip is deflected by the key, it snaps or buckles, providing tactile feedback to the user.

Growing community of inventors

Los Altos, CA, United States of America

William J West