Tabular member swinging device

• US 9,075,234 B2
• Filed: 12/14/2010
• Issued: 07/07/2015
• 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
• Primary Examiner(s): Ghebretinsae, Temesgh
• Assistant Examiner(s): Jansen, II, Michael J
• Application Number:
  US13/394,699
• Publication Number:
  US 20120169702A1
• Time in Patent Office: 1,666 Days
• Field of Search: 345/211, 345 84- 86, 359/230, 359237-324, 348/755, 348/758, 348/759
• US Class Current: 1/1
• 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 plurality of movable units comprising a support, a movable beam, a tabular member, a first electrode and a second electrode; and

a drive circuit, wherein

the plurality of movable units is arranged in a matrix in a row direction and a column direction,

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

the movable beam connects the support and the tabular member, the movable beam further supports the tabular member about a swing axis such that the tabular member can swing, and exhibit a 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, the tabular member further includes a third electrode, 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 swing axis provided to each of the movable units is shaped in a manner extending in the column direction,

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

the 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

when the drive circuit selectively applies first to fourth voltages to each of the plurality of movable units, by applying one of the third voltage and the fourth voltage to the first electrode of the moveable unit, and applying the other of the third voltage and the fourth voltage to the second electrode of the moveable unit, and when a voltage difference between the third voltage and the first voltage is greater than a voltage difference between the fourth voltage and the first voltage, one or more of the following events occur in the plurality of movable units;

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

(b) in the movable unit in which the tabular member is not swinging and in which the second voltage has been applied to the third electrode of 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 third electrode of the tabular member, the tabular member maintains a previous swing posture, and in the movable unit in which the drive circuit has applied the second voltage to the third electrode of the tabular member, the tabular member returns to a posture that is parallel to the substrate,

the drive circuit performing a concurrent reset operation configured to;

(I) during a first step, apply the second voltage to the third electrode of the tabular members of the movable units belonging to all of the rows, all of the tabular members returning to a posture that is parallel to the substrate;

(II) during a first part of a second step, select one selected row from among the rows having all of the tabular members in the posture that is parallel to the substrate;

(III) during a second part of the second step, apply, in the selected row, the third voltage to the first electrode and apply the fourth voltage to the second electrode in the column where the tabular member is to approach the first electrode, and apply the fourth voltage to the first electrode and apply the third voltage to the second electrode in the column where the tabular member is to approach the second electrode;

(IV) during a third step switch the voltage that is being applied to the third electrode of the tabular members of the movable units belonging to the selected row after the second part of the second step (III);

(C);

(V) during a fourth step, repeat the first part and the second part of the second step and third step until the voltage applied to the third electrode of all of the tabular members in all of the rows is switched to the first voltage; and

(VI) return to the first step when the fourth step is satisfied.

2. 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.