Abstract: A laser diode/pre-scan assembly associated with a printhead for a laser printer is presented. The laser diode/pre-scan assembly includes a pair of collimation lenses that are de-centered from the axes of a pair of laser beams to direct the pair of beams inwardly in a process direction and into a single pre-scan lens. A corresponding method of constructing a laser diode/pre-scan assembly for a laser printer is also presented.

Abstract: A synchronization system for an electrographic device comprises a laser driver that drives a laser source to emit a beam having an intensity that corresponds to a laser power control signal. The beam is swept across a light detector, which generates a detection signal based upon measured intensity, and a comparing device outputs a synchronization signal based upon a comparison of the detection signal with a control signal that corresponds to the laser power control signal. Alternatively, the detection signal may be compared with a reference signal where a programmable device scales at least one of the detection signal and the reference signal based upon the laser power control signal. The synchronization signal goes active in response to the laser beam in a sufficiently consistent manner regardless of the laser beam intensity by calibrating the sensitivity of the synchronization system based upon the control signal, which corresponds to the laser power control signal.

Abstract: A laser driver comprises a plurality of current sources, including at least one bias current source and at least two drive current sources. To control the laser driver, a set of operating states is defined where each operating state corresponds to a desired laser output power level and a ratio is defined that establishes a relationship between a first desired laser output and a second desired laser output. A calibration operation samples laser output power of the laser source for less than all of the operating states, computes adjustments to the current levels of the current sources based at least in part upon the ratio such that sampled laser power levels converge towards their corresponding desired laser output level. The current sources are adjusted to their corresponding computed current levels.

Abstract: A laser driver comprises a plurality of current sources, including at least one bias current source and at least two drive current sources. To control the laser driver, a set of operating states is defined where each operating state corresponds to a desired laser output power level and a ratio is defined that establishes a relationship between a first desired laser output and a second desired laser output. A calibration operation samples laser output power of the laser source for less than all of the operating states, computes adjustments to the current levels of the current sources based at least in part upon the ratio such that sampled laser power levels converge towards their corresponding desired laser output level. The current sources are adjusted to their corresponding computed current levels.

Abstract: Laser driver systems and methods are provided for controlling a laser driver coupled to a suitable laser source. The laser driver comprises a plurality of current sources, including at least one bias current source and at least two switched current sources. To control the laser driver, a laser power control signal is provided for each switched current source that corresponds to a desired laser output power. An output power error measure is defined based upon an error between a measured laser output power and the desired laser output power for each switched current source and a control system is characterized in which the output power error measures combine to change a magnitude of each of the switched current sources and the bias current source(s) such that the output power error measures converge over time.

Abstract: A synchronization system for an electrographic device comprises a laser driver that drives a laser source to emit a beam having an intensity that corresponds to a laser power control signal. The beam is swept across a light detector, which generates a detection signal based upon measured intensity, and a comparing device outputs a synchronization signal based upon a comparison of the detection signal with a control signal that corresponds to the laser power control signal. Alternatively, the detection signal may be compared with a reference signal where a programmable device scales at least one of the detection signal and the reference signal based upon the laser power control signal. The synchronization signal goes active in response to the laser beam in a sufficiently consistent manner regardless of the laser beam intensity by calibrating the sensitivity of the synchronization system based upon the control signal, which corresponds to the laser power control signal.

Abstract: Laser driver systems and methods are provided for controlling a laser driver coupled to a suitable laser source. The laser driver comprises a plurality of current sources, including at least one bias current source and at least two switched current sources. To control the laser driver, a laser power control signal is provided for each switched current source that corresponds to a desired laser output power. An output power error measure is defined based upon an error between a measured laser output power and the desired laser output power for each switched current source and a control system is characterized in which the output power error measures combine to change a magnitude of each of the switched current sources and the bias current source(s) such that the output power error measures converge over time.

Abstract: A lens has a lens body (1), reinforcing extensions (3a, 3b) and a clear aperture (9) surrounded on top and bottom by lens body. The lens is suitable for spot scanning. The lens is made of a water absorbing material, such as most polymers, particularly acrylate polymers. Aluminum sheets as vapor barriers are attached on each side of the lens body. This results in excellent resistance to change or distortion in high humidity environments.

Abstract: A coating apparatus for applying a coating liquid to a printing substrate. The coating apparatus has a rotatable first roll and a rotatable second roll, each having a surface energy. The second roll is positioned adjacent to the first roll and defines with the first roll a first nip through which the printing substrate passes A metering device is provided for applying a substantially uniform layer of coating liquid onto the second roll. The second roll in turn transfers the coating liquid to the printing substrate. The surface energy of the second roll is greater than the surface energy of the coating liquid. In one embodiment, the metering device includes a rotatable third roll and a doctor blade contacting the third roll, each having a surface energy. The surface energy of at least a portion of either or both the third roll and doctor blade is less than the surface energy of the coating liquid.

Abstract: A lens has a body (1), reinforcing extensions (3a, 3b) and a clear aperture (9) surrounded on top and bottom by lens body. The lens is suitable for spot scanning. The lens is made of a water absorbing material, such as most polymers, particularly acrylate polymers. Aluminum sheets as vapor barriers are attached on each side of the lens body. This results in excellent resistance to change or distortion in high humidity environments.

Abstract: A lens has a lens body (1), reinforcing extensions (3a, 3b) and a clear aperture (9) surrounded on top and bottom by lens body. The lens is suitable for spot scanning. The lens is made of a water absorbing material, such as most polymers, particularly acrylate polymers. Aluminum sheets as vapor barriers are attached on each side of the lens body. This results in excellent resistance to change or distortion in high humidity environments.

Abstract: A layered intermediate used in inkjet printing contains a release coat formed on a transfer medium in an area where an image has not been printed. The release coat is formed of polyvinyl pyrrolidone (PVP) or a PVP copolymer and at least one solvent selected from the group consisting of glycol solvents and diol solvents. A viscous coating of PVP or the PVP copolymer is formed on the transfer medium in an area where an image has been printed. A release layer formed from components in the release coat and components in the ink is formed on the viscous coating. A first ink layer is formed on the release layer of flocculated ink. A second ink layer is formed on the first ink layer, of ink that is substantially not flocculated.

Abstract: A coating apparatus for applying a coating liquid to a printing substrate. The apparatus includes a rotatable first roll, and a rotatable second roll positioned adjacent to the first roll and defining with the first roll a first nip through which the printing substrate passes. The apparatus also has a metering device for applying a layer of coating liquid onto the second roll, which in turn transfers the coating liquid to the printing substrate. The apparatus further has a controller that communicates with at least the second roll, wherein the controller performs the steps of determining whether the idle time of the second roll is longer than a predetermined threshold, setting a pre-spin flag if the idle time of the second roll is longer than a predetermined threshold, and directing the second roll to perform a pre-spin upon the presence of the pre-spin flag.

Abstract: A coating apparatus for applying a coating liquid to a printing substrate. The coating apparatus has a rotatable first roll and a rotatable second roll, each having a surface energy. The second roll is positioned adjacent to the first roll and defines with the first roll a first nip through which the printing substrate passes A metering device is provided for applying a substantially uniform layer of coating liquid onto the second roll. The second roll in turn transfers the coating liquid to the printing substrate. The surface energy of the second roll is greater than the surface energy of the coating liquid. In one embodiment, the metering device includes a rotatable third roll and a doctor blade contacting the third roll, each having a surface energy. The surface energy of at least a portion of either or both the third roll and doctor blade is less than the surface energy of the coating liquid.

Abstract: A coating apparatus for applying a coating liquid to a printing substrate. The apparatus includes a rotatable first roll, and a rotatable second roll positioned adjacent to the first roll and defining with the first roll a first nip through which the printing substrate passes. The apparatus also has a metering device for applying a layer of coating liquid onto the second roll, which in turn transfers the coating liquid to the printing substrate. The apparatus further has a controller that communicates with at least the second roll, wherein the controller performs the steps of determining whether the idle time of the second roll is longer than a predetermined threshold, setting a pre-spin flag if the idle time of the second roll is longer than a predetermined threshold, and directing the second roll to perform a pre-spin upon the presence of the pre-spin flag.

Abstract: The invention provides a test fluid for detecting coating flaws in a coated web and a method for testing a web coating system. The test fluid includes, water, a polyol, a surfactant, a radiant energy activated tracer compound and an organic solvent selected from the group consisting of an alkylene glycol and a dialkylene glycol. The test fluid is used to identify deficiencies in the web coating system so that adjustments to the web coating system may be made before assembling the coating system in an ink jet printer.

Abstract: An ink delivery system for an inkjet printing device has an ink cartridge, and a remote ink reservoir for containing a supply of ink. An air purge chamber is provided in flow communication between the reservoir and the cartridge. The air purge chamber includes a vent with a plug of hydrophobic material in the vent, and an outlet to the cartridge. The outlet communicates with a check valve leading to the cartridge. A screen of hydrophilic material is provided in the conduit, with a system for evacuating ink from the system to the reservoir when the printing device is not in use.

Abstract: A dry time sensor apparatus for an ink jet printer includes a light source emitting light onto a selected area of ink on a print medium such that the light reflects off of the selected area of ink. A reflective device receives the reflected light and reflects the light a second time back onto the selected area of ink such that the light is reflected a third time by the selected area of ink in a predetermined direction. The predetermined direction is substantially nonvarying over a range of angles of orientation of the print medium and a range of distances of the print medium from the light source. A reflected light detecting device receives the light reflected in the predetermined direction.

Abstract: A toner fuser system suitable for producing high quality color transparencies is provided. The fuser system includes a media conditioning assembly located directly downstream of a fuser assembly, which may be a roll fuser or an instant-on belt fuser. The conditioner assembly includes a convective heat source, a heating zone, and a convective circulation path past the heat source and the heating zone to provide convective heat transfer to a transparency in the heating zone. A transparency (or other media) with toner to be fused travels on a media path first through the fuser assembly and then through the heating zone of the conditioner assembly. The fuser assembly causes toner to adhere to the transparency just well enough to allow the transparency to pass into the conditioner. In the conditioner, the toner is reheated, thereby causing the surface of the toner to reflow into a smooth, glossy, and uniform surface that increases light transmission efficiency of color transparencies.

Abstract: An ink supply and delivery system for a printer cartridge including a printer cartridge having an interior, at least one air inlet to the interior, and at least one ink outlet from the interior. An air pump is connected to the air inlet of the printer cartridge and creates a positive pressure in the interior of the printer cartridge. The system further includes an ink source, including ink, in the interior of the printer cartridge, the ink source in fluid communication with the ink outlet of the printer cartridge whereby the positive pressure created by the air pump in the interior of printer cartridge forces ink to flow from the ink source in the interior of the printer cartridge through the ink outlet. The ink source is preferably in a resilient container, and the system alternately includes a resilient air container either within, next to, or encapsulating the resilient container of the ink source.