Voltage biased pull analog interferometric modulator with charge injection control

An apparatus, comprising:

• an array of three terminal electromechanical systems (EMS) devices arranged in a plurality of rows and columns, each EMS device including:
• a first stationary means for conducting electricity connected to a first drive line;
• a movable means for conducting electricity connected to a second drive line;
• and
• a second stationary means for conducting electricity connected to a third drive line, the movable conducting means disposed between the first and the second stationary conducting means,
• wherein a portion of the movable conducting means and the first stationary conducting means form a first variable capacitor having a first variable capacitance value, and
• wherein a portion of the movable conducting means and the second stationary conducting means form a second variable capacitor having a second variable capacitance value;
• a bias voltage circuit having a bias voltage line connected to the third drive line of each of the EMS devices in a column of the array, the bias voltage circuit configured to provide a potential difference between the second stationary conducting means and the movable conducting means;
• and
• a means for injecting electrical charge configured to electrically connect to the first drive line and the second drive line of each of the EMS devices in the column of the array such that the charge injecting means is electrically connected to the first and second drive line of only one of the EMS devices at any one time to provide a desired charge to the first stationary conducting means, wherein the charge injecting means includes
• a means for amplifying having a means for inverting an input, a means for non-inverting an input, and a means for providing an output, the input inverting means being electrically connected to the second drive line of each of the EMS devices in the column;
• a plurality of means for selectively electrically connecting the output providing means the first drive line of each of the EMS devices in the column such that the output providing means is electrically connected to the first drive line of only one EMS device at any one time;
• and
• a means for storing capacitance configured to be electrically connected to the input inverting means or to a means for charging the capacitance storing means to a charge Qin,
• wherein the charge injecting means is controlled to selectively connect the first drive line of each EMS device in the column, for each of the display elements in the column, to the output providing means while a charge from the capacitance storing means is transferred to the first drive line of the EMS device electrically connected to the charge injecting means.

A method of manufacturing, comprising:

• providing an array of three terminal electromechanical systems devices arranged in a plurality of rows and columns, each electromechanical systems (EMS) device including:
• a first stationary electrode layer connected to a first drive line;
• a movable electrode layer connected to a second drive line;
• and
• a second stationary electrode layer connected to a third drive line, the movable electrode layer disposed between the first and the second stationary electrode layers,
• wherein a portion of the movable electrode layer and the first stationary electrode layer form a first variable capacitor having a first variable capacitance value, and
• wherein a portion of the movable electrode layer and the second stationary electrode layer form a second variable capacitor having a second variable capacitance value;
• connecting a bias voltage circuit having a bias voltage line connected to the third drive line of each of the EMS devices in a column of the array, the bias voltage circuit configured to provide a potential difference between the second stationary electrode layer and the movable electrode layer;
• and
• selectively coupling a charge injection circuit to the first drive line and the second drive line of only one of the EMS devices in the column of the array at any one time to provide a desired charge to the first stationary electrode layer, wherein the charge injection circuit includes:
• an operational amplifier having an inverting input line, a non-inverting input line, and an output line, the inverting input line of the operational amplifier being electrically connected to the second drive line of each of the EMS devices in the column;
• a plurality of row-select switches controlled to selectively electrically connect the output line of the operational amplifier to the first drive line of each of the EMS devices in the column such that the output line of the operational amplifier is electrically connected to the first drive line of only one EMS device at any one time;
• and
• an input capacitor circuit configured to be electrically connected to the inverting line of the operation amplifier or to a voltage circuit for charging the input capacitor circuit to a charge Qin,
• wherein the charge injection circuit is controlled to selectively connect the first drive line of each EMS device in the column, for each of the display elements in the column, to the output line of the operational amplifier while a charge from the input capacitor circuit is transferred to the first drive line of the EMS device electrically connected to the charge injection circuit.