Method of controlling an electrowetting element with stable fluid configurations

Apparatus comprising:

• a first electrowetting element comprising:
• a first fluid;
• a second fluid immiscible with the first fluid;
• a first surface of a support plate, the first surface having:
• a first surface portion lying in a first plane, and
• a second surface portion lying in a second plane different from the first plane;
• a first electrode within the support plate;
• and
• a second electrode in contact with the second fluid;
• a second electrowetting element comprising:
• a first fluid;
• a second fluid immiscible with the first fluid;
• a second surface of the support plate, the second surface having:
• a first surface portion lying in a first plane, and
• a second surface portion lying in a second plane different from the first plane;
• and
• a first electrode within the support plate;
• and
• a second electrode in contact with the second fluid;
• at least one processor;
• and
• at least one memory comprising computer program instructions, the at least one memory and the computer program instructions configured to, with the at least one processor, perform a method comprising:
• receiving display effect data indicative of a requested display effect for display by each of the first electrowetting element and the second electrowetting element;
• for the first electrowetting element, and based on the display effect data:
• determining a first voltage value of a voltage to apply to the first electrode and the second electrode of the first electrowetting element;
• generating the voltage with the first voltage value;
• and
• applying the voltage with the first voltage value to the first electrode and the second electrode of the first electrowetting element, to switch the first electrowetting element to:
• a state a) in which:
• the first fluid contacts substantially all of the first surface portion, and
• the first fluid contacts substantially all of the second surface portion;
• or
• a state b) in which:
• the first fluid contacts a first part of the first surface portion,
• the second fluid contacts substantially all of the second surface portion, and
• the second fluid contacts a second part of the first surface portion;
• for the second electrowetting element, and based on the display effect data indicative of the requested display effect:
• determining a second voltage value of a voltage to apply to the first electrode and the second electrode of the second electrowetting element;
• generating the voltage with the second voltage value;
• and
• applying the voltage with the second voltage value to the first electrode and the second electrode of the second electrowetting element, to switch the second electrowetting element to a state in which:
• the first fluid contacts substantially all of the first surface portion, and
• the second fluid contacts substantially all of the second surface portion.