TABULAR MEMBER SWINGING DEVICE

• US 20120169702A1
• Filed: 12/14/2010
• Published: 07/05/2012
• Est. Priority Date: 12/22/2009
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho (Toyota Motor Corporation)
• Original Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho (Toyota Motor Corporation)
• Inventors: Ozaki, Takashi, Kodama, Ryo
• Granted Patent: US 9,075,234 B2
• Time in Patent Office: Days
• US Class Current: 345/211
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G09G 3/34 by control of light from an independent source

Abstract

A plurality of movable units is arranged in a matrix. First and second electrodes are used in common in the movable units arranged in a column. A plurality of third electrodes, which commonly connects tabular members of the movable units arranged in a row, is formed for each row. The drive circuit selects, in order and one by one, the third electrodes. Subsequently, the drive circuit swings the tabular member by applying a bias voltage to the selected third electrode and applying an approach voltage or a separating voltage to a plurality of the first electrodes and second electrodes. During a predetermined period of maintaining a swinging posture, the voltage applied to the third electrodes is maintained as the bias voltage. The tabular member is returned to a non-swinging state by changing the voltage applied to the third electrodes to a reset voltage after the lapse of the predetermined period.

Claims

1. A device capable of controlling a swinging state of a tabular member, comprising:

a substrate;

a support;

a movable beam;

a tabular member;

a first electrode;

a second electrode; and

a drive circuit,

wherein the support is fixed to the substrate and extends upward from the substrate,

the movable beam connects the support and the tabular member, supports the tabular member about a swing axis such that the tabular member can swing, and exhibits returnability that causes the tabular member to return to a posture that is parallel to the substrate,

the tabular member includes a first end and a second end that face each other across the swing axis, and at least a part of the tabular member is formed of a conductor,

the first electrode is formed on the substrate in a position opposing the first end,

the second electrode is formed on the substrate in a position opposing the second end,

the drive circuit applies one of a first voltage and a second voltage to the tabular member, applies one of a third voltage and a fourth voltage to the first electrode, and applies the other of the third voltage and the fourth voltage to the second electrode, and

in assuming that a distance between the first end and the first electrode and a distance between the second end and the second electrode when the tabular member is in a posture that is parallel to the substrate are d0, an approach distance when the distance between the first end and the first electrode decreases by a swing of the tabular member is d1 and a separation distance when the distance between the second end and the second electrode increases by the swing of the tabular member is d2, an approach distance when the distance between the second end and the second electrode decreases by a swing of the tabular member in an opposite direction is d1 and a separation distance when the distance between the first end and the first electrode increases by the swing of the tabular member in the opposite direction is d2, the first voltage to fourth voltage satisfy relationships of (1) to (3) below;

(1) when the distance between the first end and the first electrode and the distance between the second end and the second electrode are d0, the first voltage is applied to the tabular member, one of the third voltage and the fourth voltage is applied to the first electrode, and the other of the third voltage and the fourth voltage is applied to the second electrode, a difference in torque applied by the first electrode and torque applied by the second electrode to the tabular member exceeds the returnability;

(2) when the second voltage is applied to the tabular member, the difference in the torque applied by the first electrode and the torque applied by the second electrode to the tabular member is less than the returnability; and

(3) a value of (voltage difference between the third voltage and the first voltage)/(voltage difference between the fourth voltage and the first voltage) is smaller than a value of (separation distance d2)/(approach distance d1).

2. A device capable of controlling a swinging state of a tabular member, comprising:

a plurality of movable units comprising the movable beam, the tabular member, the first electrode and the second electrode according to claim 1,

wherein the first electrode of each movable unit is commonly connected to a drive circuit,

the second electrode of each movable unit is commonly connected to the drive circuit,

the tabular member of each movable unit is individually connected to the drive circuit,

a voltage difference between a third voltage and a first voltage is greater than a voltage difference between a fourth voltage and the first voltage, and

when the drive circuit selects one of the movable units in which the tabular member is swinging and the movable units in which the tabular member is not swinging, applies the first voltage to the tabular member of the selected movable unit, applies the second voltage to the tabular member of the remaining movable units, applies one of the third voltage and the fourth voltage commonly to the first electrode of the plurality of movable units, and applies the other of the third voltage and the fourth voltage commonly to the second electrode of the plurality of movable units, the following events occur in the plurality of movable units;

(a) in one movable unit among the movable units in which the tabular member is not swinging and in which the first voltage has been applied to the tabular member, the tabular member swings in a direction approaching the electrode to which the third voltage has been applied;

(b) in one movable unit among the movable units in which the tabular member is not swinging and in which the second voltage has been applied to the tabular member, the tabular member does not swing; and

(c) in the movable unit in which the tabular member is swinging and in which the first voltage has been applied to the tabular member, the tabular member maintains a previously assumed swinging posture, and in the movable unit in which the drive circuit has applied the second voltage to the tabular member, the tabular member returns to a posture that is parallel to the substrate.

3. A device capable of controlling a swinging state of a tabular member,

wherein the plurality of movable units according to claim 2 is arranged in a matrix in a row direction and a column direction,

the swing axis provided to each of the movable units is shaped in a manner extending in the column direction,

a first electrode of each of the movable units arranged in the column direction is commonly connected to a drive circuit, and the first electrode of each of the movable units of different columns is individually connected to the drive circuit,

a second electrode of each of the movable units arranged in the column direction is commonly connected to the drive circuit, and the second electrode of each of the movable units of different columns is individually connected to the drive circuit,

the tabular member of each of the movable units arranged in a row direction is commonly connected to the drive circuit, and the tabular member of each of the movable units of different rows is individually connected to the drive circuit, and

the drive circuit:

(A) selects a processed row and one row to be processed, applies a first voltage to the tabular members of the movable units belonging to the selected row, and applies a second voltage to the tabular members of the movable units belonging to remaining rows;

(B) in the one row to be processed, applies a third voltage to the first electrode and applies a fourth voltage to the second electrode in the column where the tabular member is to approach the first electrode, and applies the fourth voltage to the first electrode and applies the third voltage to the second electrode in the column where the tabular member is to approach the second electrode; and

(C) switches the voltage that is being applied to the tabular members at a predetermined point in time from the first voltage to the second voltage.

4. The device according to claim 1,

wherein the second voltage and the fourth voltage are a ground voltage, the third voltage is a negative voltage when the first voltage is a positive voltage, and the third voltage is a positive voltage when the first voltage is a negative voltage.

5. The device according to claim 2,

wherein the second voltage and the fourth voltage are a ground voltage, the third voltage is a negative voltage when the first voltage is a positive voltage, and the third voltage is a positive voltage when the first voltage is a negative voltage.

6. The device according to claim 3,

wherein the second voltage and the fourth voltage are a ground voltage, the third voltage is a negative voltage when the first voltage is a positive voltage, and the third voltage is a positive voltage when the first voltage is a negative voltage.