Lexmark International, Inc.

Other

John Lemaster

Christopher Dane Jones

Fei Chen

Craig Eric Hadady

Jichang Cao

Brian Scott Carpenter

David Anthony Schneider

Mark Andrew Omelchenko

Calvin Dale Murphy

Randall Lee Hudson

Delbert Lester Elliott

Thad Carlton Switzer

William Alan Menk, Jr

An imaging device includes a fuser having a heater connected to a power source via a switch. A controller generates a heater control signal for driving the heater without synchronizing the generation of the heater control signal with zero crossings of an AC voltage of the power source. The heater control signal changes between a first state indicating for the heater to be turned on and a second state indicating for the heater to be turned off. A trigger circuit receives the heater control signal and detects whether the AC voltage is within a predefined voltage span around zero volts. The trigger circuit generates a trigger signal for the switch when the AC voltage is within the predefined voltage span while the heater control signal is in the first state such that the switch causes current to pass through from the power source to the heater.

Power control for a fuser of an imaging device

An imaging device includes a controller and fuser assembly. The fuser assembly has a heat transfer and backup member defining a nip and process direction of media travel. The heat transfer member includes a resistive trace with a length twice extending transverse to the process direction. The controller selectively applies AC power to the resistive trace. The controller calculates a power level from zero power to full power to heat the trace to a predetermined set-point temperature from a measured current temperature. The controller maps the calculated power level to one of only eight actual heating power levels that become applied or not to the resistive trace to achieve a desired power flicker and harmonics response otherwise unattainable by merely applying the calculated power level. The actual heating power levels include differing numbers of consecutive half-cycles of AC power and are applied at zero-crossings thereof.

Thermal control of fuser assembly in an imaging device

A developer roll includes end seal regions subject to accumulating residual toner. An adjacent photoconductive member has a longitudinal extent with a central area defining an imaging region and longitudinal ends outside the central area defining non-imaging regions. The photoconductive member has a length extending beyond a length of the developer roll so that the end seal regions of the developer roll contact the non-imaging regions of the photoconductive member. During cleaning, the non-imaging regions become charged and discharged to electrostatically attract and transfer away the toner from the end seal regions. A blade scrapes clean the toner from the photoconductive member.

Removing residual toner from end seal regions of a developer roll of an imaging device

An image forming device includes a controller and a laser scanning unit. The laser scanning unit includes a light source for generating a laser beam for discharging a photoconductive member to create an electrostatic latent image. A first memory is housed on the laser scanning unit and stores data unique to the laser scanning unit and laser beam as characterized during production. A second memory in communication with the controller, and separate from the first memory, stores data characterizing a family of similar laser scanning units of a same type. The controller is configured to read both the first and second memories to generate data to compensate for energy variations along a scan path of the laser beam on the photoconductive member during use. The data substantially reduces energy variation from one scan path to a next.

Image forming device with laser scanner unit and memory therefor

A laser scanning unit for an image forming device includes a light source for emitting a laser beam, a scanning member having at least one reflective surface for scanning the laser beam onto an imaging surface across a plurality of scan lines, and driver circuitry for driving the light source to emit the laser beam. The driver circuitry has a first input for receiving a first signal indicating image information and a second input for receiving a second signal indicating shading information. The driver circuitry modulates the laser beam based on the first signal to form an image on the imaging surface corresponding to the image information and adjusts an output power of the modulated laser beam based on the second signal to substantially reduce energy variation across each scan line.

Laser scanning unit adjusting output power of modulated beam using shading information to reduce scan line energy variation

The invention describes a method and system for correcting linearity error of an electrophotographic device with a reduced number of lenses. The method and system insert additional time-slices in the data being processed by the electrophotographic device. The additional time-slices are inserted in the data in a predefined order based on a plurality of random numbers. The insertion of additional time-slices corrects the linearity error of the electrophotographic device.

Method and system for correcting the linearity error in electrophotographic devices

A system and method for reducing scan line jitter in laser scan systems employing a rotating mirror, including a controller for determining a unique time delay for each mirror facet and controlling laser sources so that video provided by each laser source is delayed in a scan line by the unique time delay corresponding to the mirror facet used in creating the scan line. The controller computes a facet map signature vector corresponding to each mirror facet matches the signature to a previously stored signature and assigns measured distance offset data to the mirror facets based upon the matching.

System and method for reducing scan line jitter in a laser scan unit for an imaging device

A method for compensating misalignment errors associated with a laser beam in an electrophotographic (EP) device is disclosed. A first value and a second value of a time-of-flight of the laser beam are determined. The second value of the time-of-flight is associated with a current value of SOS time and EOS time of the laser beam. The second value of the time-of-flight of the laser beam is compared with the first value of the time-of-flight. A duty cycle of a fuser of the EP device is monitored. An average value of the duty cycle of the fuser for a predetermined time period is determined. One or more alignment conditions of the laser beam are adjusted based on at least one of the comparisons of the second value and the first value of the time-of-flight of the laser beam, and the determined average value of the duty cycle of the fuser.

Method for compensating misalignment errors in electrophotographic device

A method of controlling a fuser assembly within an image forming apparatus having a fuser assembly including a heating member and a backup member cooperating with the heating member to form a nip therebetween for fusing images onto substrates passing through the nip. The method is provided to minimize or avoid a temperature droop condition of the fuser and includes the steps of determining a set point temperature for performing a fusing operation, and determining whether the image forming apparatus has transitioned from a standby mode to a print mode upon receipt of a print job. If a sensed temperature of the fuser is within a temperature range having an upper threshold temperature that is less than the heating temperature and greater than the set point temperature or a lower threshold temperature, a power control for the fuser is switched to operate in a high power region, increasing power to the fuser, to provide heat energy to the heating member.

Growing community of inventors

Lexington, KY, United States of America

John Lemaster