Method for driving optical deflecting device array, optical deflecting device array, optical deflecting device, and image projection displaying apparatus

An optical deflecting device array, comprising:

• a plurality of optical deflecting devices arrayed in one or two dimensions, each including a plate member and an electrode group including a plurality of electrodes,
• wherein the electrode group is arranged to face the plate member, and each electrode at a same position for each electrode group is wired to have a same electric potential in an entire plurality of optical deflecting devices forming the optical deflecting device array;
• wherein the optical deflecting device array is driven by a method for driving the optical deflecting device array in that each of the plurality of optical deflecting devices in which a plate member having a light reflection area rotates on a rotation axis or a fulcrum being as a center, and a light deflection operation is conducted by changing a reflection direction of an incoming light flux in that the plate member includes a conductive layer, an electrode is contacted or fixed to the conductive layer to apply the electric potential, and each of the plurality of optical deflecting devices includes the electrode group including the plurality of electrodes arranged to face the plate member, and switching an inclination direction of the plate member due to an electrostatic attraction caused by an electric potential difference between an arbitrary electrode in the electrode group and the electrode applying the electric potential to the conductive layer;
• wherein an inclination direction of the plate member of an arbitrary optical deflecting device is switched to a first inclination direction or a second inclination direction, and a gradation of each pixel is defined based on a time length of the first inclination direction or the second inclination direction,
• wherein a switch of the first inclination direction of the plate member of the arbitrary optical deflecting device is conducted by applying an electric potential which satisfies a condition 1, a condition 2, a condition 3, and a condition 4,
• wherein a switch of the second inclination direction of the plate member of the arbitrary optical deflecting device is conducted by applying an electric potential which satisfies a condition 5, a condition 6, a condition 7, and a condition 8, and
• wherein:
• the condition 1 is a condition for selecting an electric potential V1 or an electric potential V2 for each of the optical deflecting devices in response to the inclination direction in which the electric potential V1 or the electric potential V2 is applied to the electrode contacted or fixed to the conductive layer formed to the plate member;
• the condition 2 is a condition in which an electric potential V3 is applied to at least one electrode arranged at a side of the first inclination direction with respect to the rotation axis or the fulcrum from the electrode group arranged to face to the plate member, an electric potential V4 approximately equivalent to the electric potential V2 is applied to at least one electrode arranged at a side of the second inclination direction with respect to the rotation axis or the fulcrum and the electric potential V3 and the electric potential V4 are applied to the plurality of optical deflecting devices at one time with the same electric potential;
• the condition 3 is a condition in which an electrostatic attraction F1 occurred due to an electric potential difference between the electric potential V3 of the electrode arranged at the side of the first inclination direction and the electric potential V1 of the conductive layer formed to the plate member has a magnitude relation with an electrostatic attraction F2 which occurred due to an electric potential difference between the electric potential V4 of the electrode arranged at the side of the second inclination direction and the electric potential V1 of the electrode arranged at the side of the second inclination direction:
• F1>F2 when the plate member inclines in the first inclination direction at an initial state;
• and
• F1<F2 when the plate member inclines in the second inclination direction at the initial state;
• the condition 4 is a condition in which an electrostatic attraction F3 occurred due to an electric potential difference between the electric potential V3 of the electrode arranged at the first inclination direction and the electric potential V2 of the conductive layer formed to the plate member has a magnitude relation with an electrostatic attraction F4 which occurred due to an electric potential difference between the electric potential V4 of the electrode arranged at the second inclination direction and the electric potential V2 of the conductive layer formed to the plate member:
• F3>F4 when the plate member inclines in the first inclination direction at an initial state;
• and
• F3>F4 when the plate member inclines in the second inclination direction at the initial state;
• the condition 5 is a condition for selecting the electric potential V1 or the electric potential V2 for each of the optical deflecting devices in response to the inclination direction in which the electric potential V1 or the electric potential V2 is applied to the electrode contacted or fixed to the conductive layer formed to the plate member;
• the condition 6 is a condition in which an electric potential V5 approximately equivalent to the electric potential V1 is applied to at least one electrode arranged at a side of the first inclination direction with respect to the rotation axis or the fulcrum from the electrode group arranged to face to the plate member, an electric potential V6 is applied to at least one electrode arranged to the side of the second inclination direction with respect to the rotation axis or the fulcrum being as the center, and the electric potential V5 and the electric potential V6 are applied to the plurality of optical deflecting devices at one time with the same electric potential;
• the condition 7 is a condition in which an electrostatic attraction F5 occurred due to an electric potential difference between the electric potential V5 of the electrode arranged at the side of the first inclination direction and the electric potential V1 of the conductive layer formed to the plate member has a magnitude relation with an electrostatic attraction F6 which occurred due to an electric potential difference between the electric potential V6 of the electrode arranged at the side of the second inclination direction and the electric potential V1 of the electrode arranged at the side of the second inclination direction:
• F5<F6 when the plate member inclines in the first inclination direction at the initial state;
• and
• F5<F6 when the plate member inclines in the second inclination direction at the initial state;
• and
• the condition 8 is a condition in which an electrostatic attraction F7 occurred due to an electric potential difference between the electric potential V5 of the electrode arranged at the first inclination direction and the electric potential V2 of the conductive layer formed to the plate member has a magnitude relation with an electrostatic attraction F8 which occurred due to an electric potential difference between the electric potential V6 of the electrode arranged at the second inclination direction and the electric potential V2 of the conductive layer formed to the plate member:
• F7>F8 when the plate member inclines in the first inclination direction at the initial state;
• and
• F7<F8 when the plate member inclines in the second inclination direction at the initial state.