Hewlett-packard Company

Hewlett-packard Development Company, L.p.

Other

Hewlett-packard Corporation

Phillip R Luque

Jeffrey Scott Weaver

John W Huffman

David J Luman

Derek L Knee

Robert A Rust

Robert E Haines

David M Payne

James G Bearss

Tim Mitchell Hoberock

Gary E Hanson

Kenneth B Wade

Ben Tyson

Exemplary methods, apparatuses, media, and arrangements enable the implementation of one or more features in electronic devices that have (e.g., display) screens that are capable of light emission and detection. These features include, for example, scanning, (simulated) touch-screen sensitivity, and ambient light determination and compensation. The display screens may be comprised of light emitting/detecting elements, such as diodes, that can emit light for visual display and can detect light for receiving light information data. In certain described implementations, a method for implementing a feature using a display screen with emitting/detecting elements includes the actions of: activating multiple elements of an array of elements to emit light; activating multiple elements of the array of elements to detect light; producing detected light data representing the light detected by the multiple elements that are activated to detect light; and processing the detected light data to implement the feature.

Electronic device having a light emitting/detecting display screen

A scale is provided, the scale including a cavity having a resonant frequency which is alterable with variations in mass of a load applied to the cavity. The scale also typically includes a comparator operatively coupled with the cavity to detect actual resonant frequency under the load, to compare such actual resonant frequency with a reference resonant frequency, and to produce a difference signal indicative of mass of the load.

Apparatus using resonance of a cavity to determine mass of a load

The present invention provides an imaging system and method having a media stack component measuring system for identifying media characteristics. The imaging system includes a printer engine. A printer control system is in communication with the printer engine. A media holder is provided for holding a media stack including a plurality of sheets. A media stack component sensing system is provided which provides an output signal having a thickness component representative of sheet thickness of the sheets in the media stack.

Imaging system having media stack component measuring system

The present invention involves identifying media type in a media processing device. A system according to one embodiment of the invention includes a thermal energy source and a thermal energy sensor. The thermal energy source and thermal energy sensor are arranged along a media feed path so as to accommodate transfer of thermal energy to the media by the thermal energy source, diffusion of such thermal energy, and subsequent sensing of such diffused thermal energy to determine a heat capacity of the media, such heat capacity being indicative of media type.

Media identification system

The present invention relates to an apparatus for use in detecting unacceptable input media, the apparatus including a contacting element configured to engage input media during a feed operation such that the contacting element may selectively adhere to unacceptable input media and move with such unacceptable input media during the feed operation. The apparatus also includes a sensor configured to identify displacement of the contacting element, such displacement being indicative of unacceptable input media.

Apparatus for detecting unacceptable media

This invention relates to a media weight sensor of the type that includes a transducer consisting of a metal desk with a piezoelectric element fabricated by one side which form the back of a Helmholtz resonator cavity mounted in a printer so that the media going to the printer moves across the top of the Helmholtz resonator where an opening of the resonator is located. A soft, polymeric roller is used to press for media and is the transducer. The resonant frequency of the Helmholtz is affected by the media. The mass of the media adds to the mass of the resonator, thereby lowering the resonant frequency. Consequently, the heavier than media, the more the resonant frequency is lowered.

Media weight sensor using an acoustic resonator

This invention relates to a media weight sensor of the type that includes a transducer consisting of a metal disk with a piezoelectric element mounted in a printer so that the media going to the printer moves across the top of the resonator where an opening of the resonator is located. A soft, polymeric roller is used to press the media against the transducer. The resonant frequency of the resonator is affected by the media. The mass of the media adds to the mass of the resonator, thereby lowering the resonant frequency. Consequently, the heavier the media, the more the resonant frequency is lowered.

Media weight sensor using a resonant piezoelectric element

A first embodiment of an adjustment circuit for a laser diode output power compensator includes a feedback circuit for adjusting the laser diode output power compensator so that the output power of the laser diode is substantially constant. The feedback circuit includes a photodiode for measuring the output power of a VCSEL diode. The signal from the photodiode is coupled to a first amplifier. The difference between the signal from the photodiode and a first reference value is amplified and coupled through electronic switches to selectively charge one of multiple capacitors. The multiple capacitors are each coupled to one of a drive current source, a compensation current source, and a voltage controlled resistor, each of which are voltage controlled. A second amplifier is used for amplifying the difference between the signal from the photodiode and a second reference value to charge a capacitor coupled to a voltage controlled bias current source. The first embodiment of the adjustment circuit controls the bias current source, drive current source, compensation current source, and the voltage controlled resistor so that the output power of the VCSEL diode is held substantially constant. A second embodiment of the adjustment circuit uses an analog to digital converter, a digital comparator, a counter, and registers to form the feedback circuit for adjusting the laser diode output power compensator. A third embodiment of the adjustment circuit uses an analog comparator, counters, and registers to form the feedback circuit for adjusting the laser diode output power compensator.

Adjustment of a laser diode output power compensator

A laser printer produces an image of raster scan lines exhibiting a pitch distance p. The printer includes a photoreceptor and n laser sources, where n.gtoreq.2. First and second sets of laser sources, in one embodiment, produce plural optical beams which, when imaged on the photoreceptor, are separated by pitch distance p in the direction of movement of the photoreceptor. The first set and second sets of laser sources are separated by a distance S.sub.PR =c(1+qr)p, where: c=number of laser sources in each set, q=an integer, and r=number of rows of laser sources in both the first and second sets. The optical beams are modulated with pixel value data in accordance with a correspondence of image scan lines and positions of the optical beams on the photoreceptor. The photoreceptor is moved by a distance (q.multidot.c.multidot.r)p between scans. In such manner, an interleaving of the scan lines is achieved, which allows substantial separation of laser diodes on a laser diode chip.

Method and apparatus for interleaving raster scan lines in a multi-beam

A toner projection printer is provided with a developer surface which manifests a developer bias, and includes a cloud of entrained toner particles. A platen structure is positioned opposed to the developer surface and manifests a platen voltage that is attractive to the toner particles. An address plate is positioned between the developer surface and the platen structure. The address plate includes a determined thickness insulator with through pixel apertures. Each pixel aperture has at least first and second conductors that are electrically insulated from each other by the insulator, and a screen electrode for distorting the electric field between the address plate and the platen structure in a manner to reduce toner spreading. A first drive circuit is coupled to the first conductor for controllably applying a row drive voltage which is either a reference potential that exerts a repulsive force on the toner particles or a high voltage which is attractive to the toner particles. A second drive circuit is coupled to the second conductor for controllably applying a column voltage drive that is either a reference voltage (repulsive to the toner particles) or a high voltage (attractive to the toner particles). Both the column and row drive voltages are set at levels so that only when both are high can toner particles pass through the pixel aperture, be drawn towards the conductive platen and come under influence of the platen voltage. Control circuitry operates the first and second driver circuits to enable deposition of row and column dots of toner on a media sheet positioned on the platen, under influence of the platen potential. An improved platen structure is also shown which further reduces toner spreading.

Toner projection printer with means to reduce toner spreading

A current steering circuit accomplishes high speed switching of drive current through a vertical cavity surface emitting laser (VCSEL) diode. The preferred embodiment of the current steering circuit includes a first and second schottky diode, connected anode to anode, as the circuit elements used to steer the current that flows into the common connection point of the schottky diodes. The cathode of the first schottky diode is connected to the anode of the VCSEL diode. The cathode of the second schottky diode is connected to one side of a network formed from three resistors. The other side of the network is connected to the output of a CMOS invertor used to buffer the video signal which controls the steering of the current. With the output of the CMOS invertor at a high level, the second schottky diode is in the off state and the first schottky diode is in the on state, forcing drive current to flow through the VCSEL diode. With the output of the CMOS invertor at a low level, the first schottky diode is in the off state and the second schottky diode is in the on state, forcing drive current to bypass the VCSEL diode.

Current steering circuit

A toner projection printer is provided with a developer surface which manifests a developer bias, and includes a cloud of entrained toner particles. A conductive platen is positioned opposed to the developer surface and manifests a platen voltage that is attractive to the toner particles. An address plate is positioned between the developer surface and the conductive platen. The address plate includes a determined thickness insulator with through pixel apertures. Each pixel aperture has at least a first and second conductors that are electrically insulated from each other by the insulator. A first drive circuit is coupled to the first conductor for controllably applying a row drive voltage which is either a reference potential that exerts a repulsive force on the toner particles or a high voltage which is attractive to the toner particles. A second drive circuit is coupled to the second conductor for controllably applying a column voltage drive that is either a reference voltage (repulsive to the toner particles) or a high voltage (attractive to the toner particles). Both the column and row drive voltages are set at levels so that only when both are high can toner particles pass through the pixel aperture, be drawn towards the conductive platen and come under influence of the platen voltage. Control circuitry operates the first and second driver circuits to enable deposition of row and column dots of toner on a media sheet positioned on the platen, under influence of the platen potential.

Toner projection printer with improved address electrode structure

A toner projection printer is provided with a developer surface which manifests a developer bias, and includes a cloud of entrained toner particles. A platen is positioned opposed to the developer surface and manifests a platen voltage that is attractive to the toner particles. An address plate is positioned between the developer surface and the conductive platen. The address plate includes a determined thickness insulator with through pixel apertures. Each pixel aperture has at least a first conductive electrode ring positioned within the insulator and connected to a drive plate that is also positioned within the insulator. A first drive circuit positioned on one side of the insulator and is capacitively coupled to the drive plate for controllably applying a row drive voltage thereto. A second drive circuit is positioned on a second side of the insulator and is capacitively coupled to the drive plate for controllably applying a column voltage drive thereto). Both the column and row drive voltages are set at levels so that only when both are high can toner particles pass through the pixel aperture and be drawn towards the platen and come under the influence of the platen voltage. Control circuitry operates to enable deposition of row and column dots of toner on a media sheet positioned on the platen.

Toner projection printer with capacitance-coupled address electrode

A modulator for a clock pulse generator receives clock pulses from a clock pulse source, which clock pulses exhibit a reference phase. Delay circuitry is connected to the clock pulse source and includes n tap connections, each connection providing a clock pulse that is delayed by a different phase delay from the reference phase. A multiplexer is connected to each of the n tap connections and provides an output manifesting the clock pulses. A selector circuit controls the multiplexer to sequentially connect any sequence of different ones of the n tap connections to the multiplexer's output, whereby the output manifests a series of clock pulses which have different phase displacements from the reference phase.

Growing community of inventors

Boise, ID, United States of America

Phillip R Luque