CONTROLLING THE TIMING FOR THE TONER PATCH AND THE DENSITY SAMPLE SENSOR READING
Original Publication Date: 1993-Dec-31
Included in the Prior Art Database: 2004-Apr-06
Xerox Disclosure Journal
Proposed is an algorithm for the control of the timers for reading the toner patch by the Density Sample Sensor (DSS) within the interdocument area of a photoreceptor. The algorithm allows dynamic adjustments of the timers to start and stop readings when the DSS is exactly over the patch. Since the distance between the lead and trail edges of successive images is small, it is necessary to accurately control the start of the toner patch, the end of the toner patch and the enabling of the Density Sample Sensor. When a toner patch is required, a segment of the inner document lamp has its intensity reduced to a preset patch level by a timer. The timer is adjusted to occur at an exact number of machine counts after the trail edge of the image. The length of the patch zone is limited by a second timer which returns the intensity to an erase level before the end of the interimage zone. The second timer must be accurately controlled relative to the start of the next ima e. When the developer toner patch is over the field of view of the Density 8 ample Sensor, the third timer accurately enables the function of the sensor. The timing for the start and end of toner patch generation and the energizing of the Density Sample Sensor is controlled by an algorithm which adjusts timing as a function of changes in photoreceptor size.