Clearing circuit for liquid crystal apparatus

A control apparatus for an electro-optic element, the apparatus comprising:

• a first voltage converter in connection with a power supply, wherein the first voltage converter is configured to receive a supply voltage from the power supply and to output a first voltage;
• a second voltage converter in connection with the power supply, wherein the second voltage converter is configured to receive the supply voltage from the power supply and to output a second voltage;
• a third voltage converter in connection with the power supply, wherein the third voltage converter is configured to receive the supply voltage from the power supply and to output a third voltage;
• a first storage capacitor in connection with the first voltage converter and configured to store first energy at the first voltage;
• a second storage capacitor in connection with the second voltage converter and configured to store second energy at the second voltage;
• a third storage capacitor in connection with the third voltage converter and configured to supply third energy at the third voltage;
• a processor in connection with the first voltage converter and the first storage capacitor, wherein the processor is configured to provide a control signal at the first voltage;
• a driving circuit in conductive connection with the third storage capacitor and configured to supply a driving voltage to the electro-optic element, wherein the third voltage is a nominal supply voltage to operate the driving circuit, and where the third storage capacitor has sufficient capacity to operate the driving circuit;
• and
• a controller in connection with the second voltage converter and the second storage capacitor, wherein the controller is configured to supply a control signal to the driving circuit to control a state of the electro-optic element;
• wherein in response to a failure of the power supply, the first storage capacitor is configured to supply the first energy to the processor, the second storage capacitor is configured to supply the second energy to the driving circuit, and the third storage capacitor is configured to supply the third energy to the driving circuit, wherein the first energy and the second energy are sufficient to power the controller and the driving circuit respectively to transition the electro-optic element from a first state to a second state.

An electro-optic system comprising:

• an electro-optic device, comprising
• a first substrate having a first conductive layer disposed thereon;
• a second substrate having a second conductive layer disposed thereon;
• and
• an electro-optic medium disposed between the first substrate and the second substrate and in contact with the first and second conductive layers;
• and
• a control apparatus comprising:
• a first voltage converter in connection with a power supply, wherein the first voltage converter is configured to receive a supply voltage from the power supply and output a first voltage;
• a second voltage converter in connection with the power supply, wherein the second voltage converter is configured to receive supply voltage from the power supply and output a second voltage;
• a first storage capacitor in connection with the first voltage converter and configured to store first energy at the first voltage;
• a second storage capacitor in connection with the second voltage converter and configured to store second energy at the second voltage;
• a driving circuit in conductive connection with the second storage capacitor and configured to supply a driving voltage to the electro-optic element;
• a controller in connection with the first voltage converter and the first storage capacitor, wherein the controller is configured to supply a control signal to the driving circuit to control a state of the electro-optic element;
• wherein in response to a failure of the power supply, the first storage capacitor is configured to supply the first energy to the controller and the second storage capacitor is configured to supply the second energy to the driving circuit, wherein the first energy and the second energy are sufficient to power the controller and the driving circuit respectively to transition the electro-optic element from a first state to a second state.