Digital gray control in display systems

A method to make a display system, the method comprising:

• disposing one or more of control circuitry and power supply circuitry on a substrate;
• and
• disposing a pixel array comprising a plurality of pixels on the substrate by:
• disposing a data shift register for each pixel on the substrate, the data shift register to receive gray level data for that pixel in series and to output the gray level data in parallel;
• disposing a plurality of comparators for each pixel on the substrate, each comparator of the plurality of comparators to receive one bit of data from the data shift register and one bit of clock data;
• disposing a NOR gates sum circuit for each pixel on the substrate, the NOR gates sum circuit to provide a binary output based on outputs of all of the plurality of comparators for that pixel;
• disposing a flip flop circuit for each pixel on the substrate, the flip flop circuit to provide a binary output based on the binary output of the NOR gates sum circuit;
• disposing an emission transistor for each pixel on the substrate, the emission transistor controlled by the binary output of the flip flop circuit;
• and
• disposing a drive transistor serially coupled to the emission transistor for each pixel on the substrate, the drive transistor to act as a current source.

A method to operate a digital driving control-based display system, the method comprising:

• receiving gray level data at a data shift register for each pixel in a pixel array in series;
• outputting the gray level data from the data shift register in parallel;
• receiving one bit of the gray level data from the data shift register and one bit of clock data from a clock at each of a plurality of comparators;
• providing a comparison of the one bit of the gray level data and the one bit of clock data from a clock for each pixel to a NOR gates sum circuit;
• providing a binary output based on comparison outputs of all of the plurality of comparators for a pixel to a flip flop circuit;
• and
• providing a binary output from the flip flop circuit to control an emission transistor for the pixel based on the binary output of the NOR gates sum circuit, wherein the emission transistor controls activation of an emission circuit for the pixel.