1. A contact-type electric capacitive displacement sensor comprising:
a stationary element including a stationary plate and a stationary conductive pattern formed on the stationary plate, wherein the stationary conductive pattern has one or more stationary conductors distanced away from each other;
a displaceable element including a displaceable plate and a displaceable conductive pattern formed on the displaceable plate, wherein the displaceable conductive pattern has at least one displaceable conductor;
a voltage source for supplying an electric power to the sensor; and
signal detector means for detecting a variation of capacitance between the stationary and the displaceable elements, wherein each of the stationary and the displaceable elements has an insulation film associated with its corresponding conductive pattern, and the displaceable element and the stationary element are contacted with each other through the insulation films and movable relative to each other, so that the areas overlapped between the respective stationary conductors and the displaceable conductor change to thereby produce the variation of capacitance therebetween when moving relative to each other.
2. The sensor of claim 1, further comprising an elastic spring for urging the stationary element toward the displaceable element to make the stationary element and the displaceable element be in firm contact with each other.
3. The sensor of claim 2, further comprising swing means for allowing the stationary element to swing relative to the displaceable element.
4. The sensor of claim 1, the insulation film is coated on any one of the stationary and the displaceable conductive patterns.
5. The sensor of claim 4, wherein the insulation film is made from a material having a low friction coefficient, a high resistant to abrasion and a high dielectric constant.
6. The sensor of claim 5, wherein the material is selected from a group composed of a Diamond-like Carbon (DLC) and a polymer of fluoride and ethylene.
7. The sensor of claim 1, the insulation film is placed on the stationary and the displaceable plates except an area on which the stationary and the displaceable conductive patterns are formed.
8. The sensor of claim 7, wherein the insulation film is made from a material having a low friction coefficient, a high resistant to abrasion and a high dielectric constant.
9. The sensor of claim 8, wherein the material is selected from a group composed of a Diamond-like Carbon (DLC) and a polymer of fluoride and ethylene.
10. A contact-type electric capacitive displacement sensor comprising:
a stationary element including a stationary plate and a stationary conductive pattern formed on the stationary plate;
a displaceable element including a displaceable plate and a displaceable conductive pattern formed on the displaceable plate, wherein the stationary and the displaceable conductive patterns include conductors having cyclic patterns, respectively;
a voltage source for supplying an electric power to the sensor; and
signal detector means for detecting a variation of capacitance between the stationary and the displaceable elements,
wherein each of the stationary and the displaceable elements has an insulation film associated with its corresponding conductive pattern, and the displaceable element and the stationary element are contacted with each other through the insulation films and movable relative to each other, so that the area overlapped between the stationary and the displaceable conductors change to periodically produce the variation of capacitance therebetween when moving relative to each other.
11. The sensor of claim 10, further comprising an elastic member for urging the stationary element toward the displaceable element to make the stationary element and the displaceable element be in firm contact with each other.
12. The sensor of claim 10, further comprising swing means for allowing the stationary element to swing relative to the displaceable element.
13. The sensor of claim 10, wherein the cyclic patterns include zigzag patterns.
14. The sensor of claim 10, the insulation film is coated on any one of the stationary and the displaceable conductive patterns.
15. The sensor of claim 14, wherein the insulation film is made from a material having a low friction coefficient, a high resistant to abrasion and a high dielectric constant.
16. The sensor of claim 15, wherein the material is selected from a group composed of a Diamond-like Carbon (DLC) and a polymer of fluoride and ethylene.
17. The sensor of claim 10, the insulation film is placed on the stationary and the displaceable plates except an area on which the stationary and the displaceable conductive patterns are formed.
18. The sensor of claim 17, wherein the insulation film is made from a material having a low friction coefficient, a high resistant to abrasion and a high dielectric constant.
19. The sensor of claim 18, wherein the material is selected from a group composed of a Diamond-like Carbon (DLC) and a polymer of fluoride and ethylene.
20. The sensor of claim 10, wherein the stationary conducive pattern has a series of stationary conductors and the displaceable conductive pattern has a series of displaceable conductors shorter than the series of stationary conductors and a pair of shield conductors, the shield conductors being grounded and disposed at both ends of the displaceable conductors to prevent the displaceable conductors from being affected by an electric field generated at marginal portions of the stationary conductors that do not overlap the displaceable conductors.
21. The sensor of claim 20, wherein each of the stationary and the displaceable conductors has a zigzag pattern.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A miniature acoustic transducer, comprising a capacitive sound pressure-sensing element, wherein the capacitive sound pressure-sensing element comprises a back plate and a diaphragm formed in parallel to each other, wherein the back plate has multiple acoustic holes, and one surface of the diaphragm opposite to the back plate has one or more indentations, and the other surface of the diaphragm has a bridge structure to increase the deformation amount of the displacement of the diaphragm.
2. The miniature acoustic transducer as claimed in claim 1, wherein the bridge structure is a beam structure.
3. A miniature acoustic transducer, comprising:
a substrate with a back plate and a diaphragm formed thereon,
wherein the back plate has multiple acoustic holes, and one surface of the diaphragm opposite to the back plate has one or more indentations, and when a sound pressure is transmitted to the diaphragm, the indentations contact the back plate to create a support structure, while the other surface of the diaphragm has a cut bridge structure, which deforms because of the support of the indentations, to increase the deformation amount of the displacement of the diaphragm, so that the electric field distribution of the capacitor is between the diaphragm and the back plate and varies.
4. The miniature acoustic transducer as claimed in claim 3, wherein the support structure is comprised of an elastic structure with an elastic feature.
5. The miniature acoustic transducer as claimed in claim 3, wherein the bridge structure is a beam structure.
6. The miniature acoustic transducer as claimed in claim 3, wherein the bridge structure is a finger bridge structure.
7. The miniature acoustic transducer as claimed in claim 3, wherein the space between the back plate and the diaphragm is the distance of the deformation thereof caused by the bridge structure for supporting the diaphragm.
8. The miniature acoustic transducer as claimed in claim 3, wherein the back plate and the diaphragm are disposed in parallel, with the back plate being upper and the diaphragm being lower, with relation to an upward direction perpendicular to the substrate surface.
9. The miniature acoustic transducer as claimed in claim 8, wherein the back plate is formed on the substrate as a part of the substrate.
10. The miniature acoustic transducer as claimed in claim 8, wherein the diaphragm is formed on the substrate.
11. The miniature acoustic transducer as claimed in claim 3, wherein the back plate and the diaphragm are disposed in parallel, with the back plate being upper and the diaphragm being lower, with relation to an upward direction perpendicular to the substrate surface.
12. The miniature acoustic transducer as claimed in claim 11, wherein the diaphragm is formed on the substrate.
13. The miniature acoustic transducer as claimed in claim 11, wherein the back plate is formed on the substrate as a part of the substrate.
14. The miniature acoustic transducer as claimed in claim 3, wherein the diaphragm and the back plate are comprised of carbon-based polymers, silicon, silicon nitride, polycrystalline silicon, amorphous silicon, silicon dioxide, silicon carbide, germanium, gallium, arsenide, carbon, titanium, gold, iron, copper, chromium, tungsten, aluminum, platinum, nickel, tantalum or an alloy thereof.
15. The miniature acoustic transducer as claimed in claim 3, wherein the indentations for supporting the diaphragm are disposed on the back plate.