Abstract: Photoreceptor charge control for obviating the adverse effects of photoreceptor variation inherent in the photoreceptor as the result of the manufacturing process. The voltage values around the periphery of the photoreceptor commonly referred to as the Vc belt signature are measured. The readings for each of the ESVs are averaged (to find the mean) and the deviations from the mean are smoothed using a 41-term weighting function that properly removes the high frequency reading spikes while retaining the low frequency belt signature. Center weighted averaging of 41 points (n, . . . n±20) where n is a measured point on the photoreceptor that is averaged with the previous twenty readings together with the next twenty readings is initiated a few mm past the photoreceptor seam and ends a few mm before the seam—no phase shift. The readings are taken approximately every 3 mm around the periphery of the photoreceptor.

Abstract: A process control method for color quality control maintains a preselected developed mass per unit area (DMA) of black solid area by adjusting the development field during run-time operation. In order to estimate the DMA of a solid black control patch, which is outside the sensing range of an infra-red densitometer (IRD), an estimation technique is employed which accounts for system changes due to adjustment of the development field. The estimation technique includes generating two or more test patches, using a patch generator, which have DMA readings within the sensing range of the IRD. The DMA readings and corresponding development voltages of the test patches are sensed and used to calculate a developability curve. The developability curve is projected into a region beyond the sensing range of the IRD. From the developability curve, the DMA of the solid black control patch is estimated and employed in a closed feedback loop to return the system to the preselected DMA by adjusting the development field.

Abstract: An online printing parameter establishment apparatus is used with a xerographic printing device for printing high quality prints given a target value. The xerographic printing device is capable of producing at least one print control patch on a photoreceptor and is capable of sensing a value of the at least one print control patch. The xerographic printing device has a plurality of sets of inherent performance characteristic values. The online printing parameter establishment apparatus includes a controller device and a switch device. The controller device is operative to produce a first database of different ones of the sensed values. Each sensed value is associated with a respective one of the plurality of sets of inherent performance characteristic values based upon the target value. The controller device is also operative to produce a second database of a plurality of control values.

Abstract: Apparatus and method for scheduling toner patch creation at a first frequency and monitored for implementing diagnostics for a color image processor's systems parameters and system fault conditions in a manner that minimizes the waste of toner materials without compromising image quality. In the presence of a fault condition the toner patches are created at a different frequency. The number of toner patches required for the control is reduced through the use of complementary color toner patches in lieu of use of color patches for each individual toner colors.

Abstract: The present invention generally relates to an imaging system, and more specifically, a method and apparatus for accurately predicting toner usage and hence toner dispensing requirements in an imaging system. The toner concentration control system maintains toner concentration in a developer structure, which is connected to a dispenser containing toner.

Abstract: The present invention generally relates to an imaging system, and more specifically, a method and apparatus for accurately predicting toner usage and hence toner dispensing requirements in an imaging system. More particularly, the present invention relates to a toner concentration control system for maintaining toner concentration in a developer structure, which is connected to a dispenser containing toner. The toner concentration control system comprises: a sensor, reading the toner concentration; means for determining a toner age correction of toner concentration read by the sensor based on toner age of the toner in the developer structure; means for adjusting a toner concentration target based on the correction; and means for generating a feedback dispense command based on the adjusted toner concentration target to dispense toner into the developer structure to maintain the toner concentration in the developer structure.

Abstract: The present invention generally relates to an imaging system, and more specifically, a method and apparatus for accurately predicting toner usage and hence toner dispensing requirements in an imaging system. More specifically, the present invention relates to a toner concentration control system for maintaining toner concentration in a developer structure, which is connected to a dispenser containing toner.

Abstract: The present invention generally relates to an imaging system, and more specifically, a method and apparatus for accurately predicting toner usage and hence toner dispensing requirements in an imaging system. More specifically, the present invention relates to a feed forward toner concentration control system and method for replacing toner in each developer structure, which was used to develop a latent image on a photoreceptor belt, in order to maintain toner concentration in at least one developer structure. First and second pixel counts for first and second toner in each sector are received. The first toner mass is estimated based on first pixel counts. The second toner mass is estimated based on second pixel counts.

Abstract: The present invention generally relates to an imaging system, and more specifically, a method and apparatus for accurately predicting toner usage and hence toner dispensing requirements in an imaging system. More particularly, the present invention relates to a toner concentration control system for maintaining toner concentration in a developer structure, which is connected to a dispenser containing toner.

Abstract: The present invention generally relates to an imaging system, and more specifically, a method and apparatus for accurately predicting toner usage and hence toner dispensing requirements in an imaging system. More, specifically, the present invention relates to a toner concentration control system for maintaining toner concentration in a developer structure, which is connected to a dispenser containing toner.

Abstract: The present invention generally relates to an imaging system, and more specifically, a method and apparatus for accurately predicting toner usage and hence toner dispensing requirements in an imaging system. More specifically, the present invention relates to a toner concentration control system for maintaining toner concentration in a developer structure, which is connected to a dispenser containing toner.

Abstract: A light collector for directing light to a concentrated area on a target surface such as for use with a linear LED array used as an erase lamp in an electrophotographic printer. The collector includes a compound cylinder lens supported by a pair of reflecting members. The reflecting members reflect light rays from the LED array to the cylinder lens. The cylinder lens includes a lower surface for capturing the reflected light rays and a tongue extending from the lower surface for capturing light rays directly from the LED array. The cylinder lens directs and concentrates the captured light rays in a narrow line on a target surface.

Abstract: An online printing parameter establishment apparatus is used with a xerographic printing device for printing high quality prints given a target value. The xerographic printing device is capable of producing at least one print control patch on a photoreceptor and is capable of sensing a value of the at least one print control patch. The xerographic printing device has a plurality of sets of inherent performance characteristic values. The online printing parameter establishment apparatus includes a controller device and a switch device. The controller device is operative to produce a first database of different ones of the sensed values. Each sensed value is associated with a respective one of the plurality of sets of inherent performance characteristic values based upon the target value. The controller device is also operative to produce a second database of a plurality of control values.

Abstract: A method of automatically positioning a test pattern in the interdocument zone of an imaging surface of a printing machine using a sensor with a given field of view. Once the test pattern has been provided in the interdocument zone of the imaging surface, the timing relationship of the test pattern to a plurality of edges of the sensor field of view is determined. The control then responds to the timing relationships to locate the sensor field of view with respect to the test pattern and determine the time period between creating a test pattern and sensing the test pattern.

Abstract: In a xerographic printer for tri-level highlight color imaging, two electrostatic voltmeters (ESVs) are used to interpolate the electrostatic potential at a particular location along the path of the photoreceptor belt. Anomalous ESV readings, such as would be caused by dirt interfering with the ESV itself as opposed to systemic changes in the whole apparatus, are detected by having the printer enter a "test mode" in which test patches having minimal charge are monitored by the ESVs. The low-charge test patches enable noise related directly to the ESVs to be isolated from other possible sources of noise. The noise which results from ESV malfunctioning is compensated for when the printer returns to operation.

Abstract: A heat and pressure fuser for fixing toner images to substrates. A dual heating lamp arrangement is utilized for elevating the surface temperature of a heated fuser roll. The operation of the dual heat lamps is controlled using dual thermistors for maintain steady state temperature fluctuations to .+-.3.degree. F. The thermistors are positioned, one adjacent the inboard end of the fuse and the other adjacent the outboard end thereof. The outboard thermistor is used to determine the desired on time of the fuser lamp and the inboard thermistor is used to determine which of the two lamps is on. If the inboard temperature is below a predetermined target value a 14 inch lamp is turned on. If the inboard temperature is at or above a predetermined target value an 11 inch lamp is turned.

Abstract: A pair of Electronic Voltmeters (ESV) are utilized to control the photoreceptor charging voltage in a Tri-Level imaging apparatus. One of the ESVs is used to control the voltage increases of a charging device. The other ESV is used to monitor the charge level of the charged area image of a Tri-Level image. When a critical value is sensed the control of the charging device is shifted to the ESV that monitors the charged area image level and limits the output from the charging device to a predetermined target value.

Abstract: Erroneous voltage readings of Electrostatic Voltmeters (ESVs), which have become contaminated by charged particles (i.e. toner) from developer housings used for developing latent images on a photoreceptor surface, are negated by adjusting the readings of the ESVs to compensate for the contamination of the ESVs. Additionally, The developer housing biases are adjusted by an amount equal to the difference between the voltages measured by the ESVs thereby insuring proper development and cleaning fields during development.

Abstract: Infra-Red Densitometer (IRD) readings are utilized to check the efficiency of two-pass cleaning of the black toner patch in a tri-level imaging apparatus. The IRD examines the background patch of the tri-level image and declares a machine fault if excessive toner is detected.

Abstract: In a single pass tri-level imaging apparatus, a pair of Electrostatic Voltmeters (ESV) are utilized to monitor various control patch voltages to allow for feedback control of Infra-Red Densitometer (IRD) readings.The ESV readings are used to adjust the IRD readings of each toner patch. For the black toner patch, readings of an ESV positioned between two developer housing structures are used to monitor the patch voltage. If the voltage is above target (high development field) the IRD reading is increased by an amount proportional to the voltage error. For the color toner patch, readings using an ESV positioned upstream of the developer housing structures and the dark decay projection to the color housing are used to make a similar correction to the color toner patch IRD readings (but opposite in sign because, for color, a lower voltage results in a higher development field).