Abstract: A method of maintaining consistent large solid area development by developing a large area test patch covering the image area of a photorececptor and detecting the lead edge and trail edge density of the test patch using a densitometer to measure reflectance and comparing the lead and trail edge density to the lead and trail edge density of a reference patch. The reference patch is generated after the changing of developer elements such as developer material and photoreceptor and an electrostatic set up performed. Alternatively a density differential between lead and trail edge density of the test patch is detected. Electrostatic parameters such as preset toner concentration control values and decreasing the development field of the test patch are adjusted to maintain constant large solid area development.

Abstract: An image processing apparatus having a corona device for charging a photoreceptor to voltage levels, a developer for applying toner to the photoreceptor, and a sensor for providing a signal in relation to photoreceptor voltage for adjusting the photoreceptor voltage levels by providing signals from the sensor in response to periodic electrostatic set ups which includes developing a series of predetermined test patches on the photoreceptor, relating the signals to characteristics of the photoreceptor, adjusting the corona device for the characteristics in response to the signals, and measuring cycle down and short term photoreceptor rest recovery changes in photoreceptor voltage for use in adjusting the corona device.

Abstract: A method for measuring the position of a stepping motor by generating a signal representative of the back electromotive force induced by the rotor in the coils of the motor, and estimating the actual position of the rotor from the signal representative of the back electromotive force induced by the rotor.

Abstract: A method of automatically altering the messages for prompting an operator, depending upon the level of operator training, in a reproduction machine having a control and user interface with display including the steps of programming the machine at a first level, recognizing the programming of the machine at the first level to represent either trained or untrained operator programming, responding to the recognition of either trained or untrained operator programming at the first level for providing either a trained sequence of operator prompts or an untrained sequence of operator prompts, programming the machine at a second level after completion of the programming at the first level, recognizing the programming of the machine at the second level to be either trained or untrained operator programming, and responding to the recognition of either trained or untrained operator programming at the second level for providing either a trained sequence of operator prompts or an untrained sequence of operator prompts.