Switching device
First Claim
1. A switching device which comprises:
- a swinging element that is able to move back and forth between two end positions, the two end positions being on either side of a zero position;
an elastic member connecting said swinging element to a base, said elastic member allowing said swinging element to move back and forth between the two end positions;
stationary actuating electrodes producing electrostatic forces of attraction to said swinging element when said swinging element is at the end positions, the forces of attraction acting away from the zero position; and
a control circuit for controlling the electrostatic forces of attraction;
wherein said elastic member provides a return force that acts toward the zero position, the return force being greater than the force of electrostatic attraction produced by said control circuit and one of said actuating electrodes such that said swinging element has a switching time based upon its natural mechanical oscillation frequency.
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0 Petitions
Accused Products
Abstract
A switching device comprises a swinging element (1) that is able to move between two end positions (A, B). Holding electrodes (4, 5) are placed in end positions (4, 5). A control circuit (8) controls the switching by generating signals of suitable voltage. Swinging element (1) is attached in an elastic manner (for example, by a flexible rod 2) in such a way that the elastic return force which tends toward a zero position (0) has, in an essential amplitude range, a higher value than the electrostatic force of attraction created by the control circuit and holding electrodes (4, 5) and acts in the opposite direction, in such a way that the switching time of the swinging element is determined primarily by its natural frequency and not by the magnitude of the electrostatic force of attraction.
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Citations
25 Claims
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1. A switching device which comprises:
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a swinging element that is able to move back and forth between two end positions, the two end positions being on either side of a zero position; an elastic member connecting said swinging element to a base, said elastic member allowing said swinging element to move back and forth between the two end positions; stationary actuating electrodes producing electrostatic forces of attraction to said swinging element when said swinging element is at the end positions, the forces of attraction acting away from the zero position; and a control circuit for controlling the electrostatic forces of attraction; wherein said elastic member provides a return force that acts toward the zero position, the return force being greater than the force of electrostatic attraction produced by said control circuit and one of said actuating electrodes such that said swinging element has a switching time based upon its natural mechanical oscillation frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A switching unit that comprises a plurality of switching devices, each of the switching devices comprising:
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a swinging element that is able to move back and forth between two end positions, the two end positions being on either side of a zero position; an elastic member connecting said swinging element to a base, said elastic member allowing said swinging element to move back and forth between the two end positions; and stationary actuating electrodes producing electrostatic forces of attraction to said swinging element when said swinging element is at the end positions, the forces of attraction acting away from the zero position; wherein said elastic member provides a return force that acts toward the zero position, the return force being greater than the force of electrostatic attraction produced by said control circuit and one of said actuating electrodes such that said swinging element has a switching time based upon its natural mechanical oscillation frequency, and wherein said switching unit further comprises; a control circuit for controlling the electrostatic forces of attraction; wherein the swinging electrodes or their actuating electrodes of several of the switching devices are connected by common conductors to said control circuit, whereby a selected switching device may be actuated by lowering the voltage on selected conductors that are connected to the selected switching device. - View Dependent Claims (19)
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20. An optical unit that comprises at least one switching device for selectively blocking and passing optical signals, said switching device comprising;
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a swinging element that is able to move back and forth between two end positions in order to block or expose a passage opening, the passage opening permitting optical signals to pass through, the two end positions being on either side of a zero position; an elastic member connecting said swinging element to a base, said elastic member allowing said swinging element to move back and forth between the two end positions; and stationary actuating electrodes producing electrostatic forces of attraction to said swinging element when said swinging element is at the end positions, the forces of attraction acting away from the zero position; wherein said elastic member provides a return force that acts toward the zero position, the return force being greater than the force of electrostatic attraction produced by said control circuit and one of said actuating electrodes such that said swinging element has a switching time based upon its natural mechanical oscillation frequency, and wherein said optical unit further comprises; a control circuit for controlling the electrostatic forces of attraction; wherein said optical unit constitutes a controlled screen, said optical unit further comprising an optical lens system having its focal plane in or near a plane of said controlled screen. - View Dependent Claims (21, 22)
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23. A process for controlling a switching device having a swinging element, an elastic member connecting the swinging element to a base and allowing the swinging element to move back and forth between two end positions, the two end positions being on either side of a zero position, stationary actuating electrodes respectively adjacent the end positions producing electrostatic forces of attraction to the swinging element when the swinging element is at the end positions, the forces of attraction acting away from the zero position, and a control circuit for controlling the electrostatic forces of attraction, comprising the steps of:
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providing a holding voltage to a first one of the actuating electrodes when the swinging element is at a first one of the end position, the holding voltage producing a voltage difference between the first actuating electrode and the swinging element thereby creating an electrostatic force of attraction to the swinging element, the force of attraction being greater than a return force of the elastic member acting toward the zero position; releasing the swinging element from its held position at the end position by temporarily reducing the voltage difference between the swinging element and the actuating electrode, such that the swinging element can oscillate to the other end position under natural mechanical oscillation due to the return force of the elastic member, the return force being greater than the electrostatic force of attraction for at least a portion of the path of movement of the swinging element between the two end positions; and providing a new holding voltage to the second one of the actuating electrodes when the swinging element is at the second end position, the holding voltage producing a voltage difference between the second actuating electrode and the swinging element thereby creating an electrostatic force of attraction to the swinging element, the force of attraction being greater than a return force of the elastic member acting toward the zero position. - View Dependent Claims (24, 25)
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Specification