Hewlett-packard Development Company, L.p.

Hewlett-packard Company

Akinobu Kuramoto

John Phillip Ertel

Robert L Cobene

Rene P Helbing

Steven W Trovinger

Geraint Owen

A method for aligning print media on a feedpath includes the steps of: aligning a sheet of print media using a deskew mechanism; measuring the skew of the sheet after it has been aligned; and comparing the measured skew with a specified skew, and if the measured value is greater than the specified value, reversing the sheet through the deskew mechanism followed by repeating the aligning, measuring and comparing steps. An apparatus for implementing alignment of print media on a feedpath comprises a deskew mechanism and sensors positioned downstream on the feedpath from the deskew mechanism to provide data sufficient to calculate the skew of the sheet.

Multi-pass deskew method and apparatus

The skew of a sheet of print media is precisely controlled by intentionally inducing print media deformation, so that cooperative mechanical and gravitational forces may be used to align the leading edge of the sheet. The sheet is driven into a nip region of deskew rollers in a manner that causes the print media to deform, lifting a movable member in a direction substantially perpendicular to the feedpath into the nip region. The movable member applies a return force that is generally equal along a widthwise surface region of the print media. As a result, there is a reduced likelihood that the print media will be skewed relative to the nip region. In some applications, the return force is adjustable.

Deskew mechanism and method

Systems and methods of binding sheets by activating a microencapsulated binding agent are described. Each sheet to be bound has an exposed binding surface region near a spine edge. A frontside adhesive system is disposed over the frontside binding surface region and comprises a binding agent that is encapsulated in a plurality of microcapsules. The adhesive system is non-tacky to enable the sheets to be stacked and individually processed until the binding agent is released from the microcapsules.

Binding sheets by activating a microencapsulated binding agent

Systems and methods of dispensing adhesive in a bookbinding system are described. Sheets may be bound into bound text bodies having respective spines exposed for adhesive application and characterized by multiple length dimensions and multiple thickness dimensions. In one aspect, a sheet binding system comprises an adhesive dispenser that is configured to dispense across the thickness dimension of a text body spine solid sheet adhesive having one of multiple effective widths that is sized to correspond substantially to the length dimension of the text body spine. In accordance with this approach, books of different lengths (or heights) may be readily bound with solid sheet adhesive that may be contained within a single, replaceable cartridge housing.

Dispensing adhesive in a bookbinding system

Systems and methods of determining when adhesive in a replaceable adhesive dispenser is nearly spent are described. In one aspect, a bookbinding system includes a receptacle for receiving a plug-in cartridge housing of an adhesive dispenser that contains a length of solid sheet adhesive wound into a roll, and an adhesive quantity interrogator that is configured to obtain an indication of the length of solid sheet adhesive remaining within the plug-in cartridge housing. In another aspect, an adhesive dispenser includes a plug-in cartridge housing that is configured to plug into a receptacle of a bookbinding system, a length of solid sheet adhesive that is disposed within the plug-in cartridge housing and wound into a roll, and an indicator of the length of solid sheet adhesive remaining within the plug-in cartridge housing.

Determining when adhesive in a replaceable adhesive dispenser is nearly spent

Systems and methods of managing consumables used in a bookbinding system are described. In one aspect, a bookbinding consumables quantity interrogator is configured to obtain information relating to usage of one or more consumables in a bookbinding system, and a processor is configured to compute usage statistics for the one or more bookbinding consumables based upon usage information obtained by the bookbinding consumables quantity interrogator.

Managing bookbinding consumables

A method of illuminating a light valve using a light source with modulated intensity to improve light throughput and color balance while minimizing loss of color resolution. A light valve is provided that includes a light input, a light output and a spatial light modulator including an array of pixels. The spatial light modulator is illuminated through the light input with light generated by a light source having a nominal lamp power dissipation level. Image data is provided and the array of pixels is configured based on the image data during a display period so that the image data is represented in light from the light source received at the light output. During a portion of the display period, the intensity of the light generated by the light source is increased to a high level above the nominal lamp power dissipation. During another portion of the display period, the intensity of the light generated by the light source is decreased to a low level below the nominal lamp power dissipation level. The average lamp power dissipation level over the display period is maintained at a level that does not exceed the nominal lamp power dissipation level. The light valve provided may additionally include a color sequencer for sequentially selecting one of a first, a second, and a third colorband of light that may reach the light output. Alternatively, the light valve provided may include a first, a second, and a third spatial light modulator and a color separator for directing a first, a second, and a third colorband of light from light received at the light input to the first, the second, and the third spatial light modulator, respectively. The light valve provided may also include a first, second, and third shutter between the color separator and the first, second, and third spatial light modulator, respectively.

Method of illuminating a light valve with improved light throughput and color balance correction

A ferroelectric liquid crystal-based light valve system with contrast control and a method for controlling contrast in a ferroelectric liquid crystal-based light valve system. The light valve system includes a light input, a ferroelectric liquid crystal-based spatial light modulator, an analyzer, and a voltage controller. The ferroelectric liquid crystal-based spatial light modulator includes signal processing electronics and an array of pixels. The array of pixels is configured to receive light from the light input and includes an array of pixel electrodes, a transparent electrode, and a layer of ferroelectric liquid crystal material. Each pixel electrode is independently switchable between a first voltage level and a second voltage level by the signal processing electronics. One of these levels may be a variable input voltage level. The analyzer has orthogonal directions of maximum transmissivity and minimum transmissivity. The voltage controller is configured to adjust at least one of the first voltage level and the second voltage level through a first range of voltages and a second range of voltages, respectively. As the voltage controller adjust the variable input voltage level, the direction of polarization of light exiting the pixels may rotate by at least 2 degrees in order to precisely align the direction of polarization with the direction of minimum transmissivity. The light valve system may further comprise a light intensity sensor and a feedback circuit in electrical communication with the light intensity sensor and the voltage controller. The method of controlling contrast in a ferroelectric light valve system begins by providing a ferroelectric liquid crystal-based spatial light modulator that includes a plurality of pixels and signal processing electronics. The signal processing electronics independently switch an electric field across each of the plurality of pixels between a forward direction and a reverse direction. An analyzer having a direction of minimum transmissivity is also provided. The pixels are then illuminated and a contrast control signal is detected. Detecting the control signal may include checking for an input from a contrast control user interface. Detecting the control signal may also include providing an automatic contrast control feedback circuit. The second direction of polarization is then rotated by changing the magnitude of the electric field across the plurality of pixels in response to the control signal.

Liquid crystal light valve system with contrast control

A method of digital grayscale control using light source modulation. First, a light valve, grayscale data, and a light source are provided. The light valve includes a spatial light modulator with at least one pixel. The grayscale data indicates desired grayscale level for the pixel during a frame period. The light source is configured to illuminate the pixel, to generate light with increasing intensity for a rise-time after electric power to the light source is substantially increased, and to generate light with decreasing intensity for a decay-time after electric power to the light source is substantially reduced. The light source may be an arc-lamp. The rise-time and the decay-time taken together may constitute a majority of the frame period. During the frame period, the electric power to the light source is substantially increased and is substantially decreased. Substantially decreasing the electric power to the light source may include turning off the electric power. The frame period is divided into at least four time slices with independent durations so that at least one of the at least four time slices occurs completely during the decay time. This may include selecting the at least four independent durations so that a product of each of the at least four independent durations and an average intensity of the light generated by the light source over each of the at least four time slices, respectively, has a binary weighted value, respectively. The pixel is independently set to one of an 0 state and an 1 state during each of the at least four time slices of the frame period based on the grayscale data.

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Pleasanton, CA, United States of America

Akinobu Kuramoto