Xerox Corporation

Dale C Thomas

Lawrence P Lavery

David G Wilcox

A power regulating device which maintains a constant rms voltage across a load by periodically interrupting the application of voltage to the load for a predetermined number of cycles. To accomplish this, a functional solution to the equation which describes the relationship between the rms line voltage developed across the load and the rms voltage of a desired control set point is continuously provided. The solution of this equation is obtained by squaring a sampling of the applied load voltage, subtracting the square of the desired control voltage, and then integrating over time the difference therebetween. When the resultant time integral reaches a predetermined constant value, the voltage applied to the load is interrupted for a predetermined number of half or full cycles.

Rms voltage controller

In a radiant energy beam scanning system, a detector, positioned at a predetermined position along the path scanned by the beam, for sensing the center position of the power distribution within the beam and generating a signal indicative thereof. When utilized in an information recording system, the detector is positioned adjacent the start position of the scan path so that the generated indicator signal provides a reference for system timing and synchronization. In such a recording environment, synchronization of the system relative to the center position of power distribution within the beam compensates for variations in beam power level and focus, assuring proper alignment of information recorded on consecutive scan lines. In a preferred form, a diode detector, partially masked in a cross-scan direction, is employed to provide an output signal when irradiated by the scanning beam. The detector output signal is amplified and filtered to provide a reference signal which represents the average total power of the beam. The reference signal is divided in half and supplied to a comparator for comparison with the detector output signal. As the beam crosses the edge of the mask, the detector output decreases rapidly towards zero. When this output signal reaches 50% of the average total power level, the comparator switches, creating the indicator signal.

Scanning beam detector

An automatic development control system having a sensor providing a signal representative of developed toner mass on a patch sample on the photoreceptor. The signal is conveyed to a comparator through signal processing circuits for comparing with a reference signal. The signal processing circuits include digital to analog circuitry also capable of providing analog to digital conversion. The reference signal represents an undeveloped photoreceptor signal normalized to accommodate changing photoreceptor, sensor and operating environment characteristics. A dispenser solenoid activates a toner dispenser through an interrupt mechanism in given increments of time depending upon the error signals generated by the comparator.

Automatic development dispenser control

Circuitry for establishing a variable voltage reference for a circuit which amplifies and shifts an input signal. When a known input signal is applied to the circuitry, a counter is incremented to increase in a stepped fashion the variable voltage until the circuit output reaches a region of tolerance around a desired set point. The counter is then stopped and remains in that state, holding the variable voltage reference at its last value.

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Ontario, NY, United States of America

Dale C Thomas