Electrostatic actuator and camera module using the same

A method of driving an electrostatic actuator, the electrostatic actuator including:

• a first stator section including a first electrode array including first, second and third electrodes arranged at a predetermined pitch in a first direction;
• a second stator section arranged to face the first stator section and to define a space between the first and second stator sections, and including a second electrode array including fourth, fifth and sixth electrodes arranged at the predetermined pitch in the first direction;
• and
• a movable section arranged in the space and including a first electrode section facing the first electrode array and a second electrode section facing the second electrode array, the first and second electrode sections being maintained at a predetermined potential,
• the driving method comprising,
• applying at least first, second, third, and fourth DC voltage signals to the first and second electrode arrays, alternatively, each DC voltage signal having a first level higher than the predetermined potential and a second level lower than the predetermined potential,
• the first DC voltage signal being applied to the adjacent first and second electrodes of the first electrode array to attract the first electrode section of the movable section during a first period, the first and second electrodes of the first electrode array being maintained at the first and second levels during the first period, respectively,
• the second DC voltage signal being applied to the adjacent fourth and fifth electrodes of the second electrode array to attract the second electrode section of the movable section during a second period, the fourth and fifth electrodes of the second electrode array being maintained at the first and second levels during the second period, respectively,
• the third DC voltage signal being applied to the adjacent second and third electrodes of the first electrode array to attract the first electrode section of the movable section during a third period, the second and third electrodes of the first electrode array being maintained at the first and second levels during the third period, respectively,
• the fourth DC voltage signal being applied to the adjacent fifth and sixth electrodes of the second electrode array to attract the second electrode section of the movable section during a fourth period, the fifth and sixth electrodes of the second electrode array being maintained at the first and second levels during the fourth period, respectively, and
• the movable section being moved in the first direction in accordance with the application of the first, second, third and fourth DC voltage signals.

A method of driving an electrostatic actuator, the electrostatic actuator including:

• a first stator section including first and second electrode arrays each including first, second and third electrodes and arranged substantially in parallel and at a predetermined pitch in a first direction;
• a second stator section arranged to face the first stator section and to define a space between the first and second stator sections, and including a third electrode array including fourth and fifth electrodes;
• and
• a movable section arranged in the space and including a first electrode section facing the first and second electrode arrays and a second electrode section facing the third electrode array, the first and second electrode sections being maintained at a predetermined potential,
• the method comprising,
• applying at least first, second, and third DC voltage signals to the first, second and third electrode arrays, alternatively, each DC voltage signal having a first level higher than the predetermined potential and a second level lower than the predetermined potential,
• the first DC voltage signal being applied to the first and second electrodes of the first and second electrode arrays to attract the first electrode section of the movable section during a first period, the first and second electrodes of the first and second electrode arrays being maintained at the first and second levels during the first period, respectively,
• the second DC voltage signal being applied to the fourth and fifth electrodes of the third electrode array to attract the second electrode section of the movable section during a second period,
• the third DC voltage signal being applied to the second and third electrodes of the first and second electrode arrays to attract the first electrode section of the movable section during a third period, the second and third electrodes of the first and second electrode arrays being maintained at the first and second levels during the third period, respectively, and
• the movable section being moved in the first direction in accordance with the application of the first, second and third DC voltage signals.

A method of driving an electrostatic actuator, the electrostatic actuator including:

• a first stator section including first and second electrode arrays each including first and second electrodes and arranged substantially in parallel and at a predetermined pitch in a first direction;
• a second stator section arranged to face the first stator section to define a space between the first and second stator sections, and including third and fourth electrode arrays each including third and fourth electrodes arranged substantially in parallel at the predetermined pitch in the first direction, the third and fourth electrode arrays having an arrangement of the third and fourth electrodes that is deviated by half of the predetermined pitch from the arrangement of the first and second electrodes in the first and second electrode arrays;
• and
• a movable section arranged in the space and including a first electrode section facing the first and second electrode arrays and a second electrode section facing the third and fourth electrode arrays, the first and second electrode sections being maintained at a predetermined potential,
• the method comprising,
• applying at least first, second, third, and fourth DC voltage signals to the first, second, third and fourth electrode arrays, alternatively, each DC voltage signal having a first level higher than the predetermined potential and a second level lower than the predetermined potential,
• the first DC voltage signal being applied to the first electrodes of the first and second electrode arrays to attract the first electrode section of the movable section during a first period, the first electrodes of the first and second electrode arrays being maintained at the first and second levels during the first period, respectively,
• the second DC voltage signal being applied to the third electrodes of the third and fourth electrode arrays to attract the second electrode section of the movable section during a second period, the third electrodes of the third and fourth electrode arrays being maintained at the first and second levels during the second period, respectively,
• the third DC voltage signal being applied to the second electrodes of the first and second electrode arrays to attract the first electrode section of the movable section during a third period, the second electrodes of the first and second electrode arrays being maintained at the first and second levels during the third period, respectively,
• the fourth DC voltage signal being applied to the fourth electrodes of the third and fourth electrode arrays to attract the second electrode section of the movable section during a fourth period, the fourth electrodes of the third and fourth electrode arrays being maintained at the first and second levels during the fourth period, respectively, and
• the movable section being moved in the first direction in accordance with the application of the first, second, third and fourth DC voltage signals.

A method of driving an electrostatic actuator, the electrostatic actuator including:

• a first stator section including first, second and third electrode arrays each including first, second and third electrodes arranged substantially in parallel at a predetermined pitch in a first direction;
• a second stator section arranged to face the first stator section and to define a space between the first and second stator sections, and including a fourth electrode array including fourth and fifth electrodes;
• a movable section arranged in the space and including a first electrode section facing the first, second and third electrode arrays and a second electrode section facing the fourth electrode array, the first and second electrode sections being maintained at a predetermined potential,
• the driving method comprising,
• applying at least first, second, and third DC voltage signals to the first, second, third and fourth electrode arrays, alternatively, the DC voltage signal having a first level higher than the predetermined potential and a second level lower than the predetermined potential,
• the first DC voltage signal being applied to the first and second electrodes of the first, second and third electrode arrays to attract the first electrode section of the movable section during a first period, the first and second electrodes of the first and third electrode arrays being maintained at one of the first and second levels during the first period and the first and second electrodes of the second electrode array being maintained at the other of the first and second levels during the first period,
• the second DC voltage signal being applied to the fourth and fifth electrodes of the fourth electrode array to attract the second electrode section of the movable section during a second period,
• the third DC voltage signal being applied to the second and third electrodes of the first, second and third electrode arrays to attract the first electrode section of the movable section during a third period, the second and third electrodes of the first and third electrode arrays being maintained at one of the first and second levels during the third period, the second electrodes of the second electrode array being maintained at the other of the first and second levels during the third period, and
• the movable section being moved in the first direction in accordance with the application of the first, second and third DC voltage signals.