Patent US5428473A successfully refreshed from Google Patents.
US5428473A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mirror driving apparatus for optical disk drive
Assignee: Panasonic Holdings Corp
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Filing: 1993-04-06
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Granted: 1995-06-27
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Expires: 2013-04-06
Abstract
Abstract A mirror driving apparatus includes a rotary mirror, a support member for rotatably supporting the rotary mirror, a driving section for rotating the rotary mirror, a rotary electrode mounted on the rotary mirror or the support member, a fixed electrode disposed close to the rotary electrode and generally parallel thereto, a fixing section to which the support member and the fixed electrode are mounted, and a detecting section for detecting electrostatic capacity or a variation thereof between the rotary electrode and the fixed electrode. A mechanical vibration system, formed by the rotary mirror and the rotary mirror support member, is controlled based on the amount of rotary movement of the rotary mirror detecting as a change in capacity between the electrodes to suppress resonance of the rotary mirror. Additionally, by superposing an additional high frequency component outside the control band onto the rotary mirror control signal, the rotary mirror can be moved in fine increments. Thus, a dead band region (hysteresis characteristic) of the mechanical vibration system is limited.
Inventors
- 👤 Teruyuki Takizawa
- 👤 Yoshikazu Goto
- 👤 Toshiyuki Shimada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:27
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/0925; G11B7/085; G11B7/08547; G11B7/08564
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
156 words
A mirror driving apparatus comprising: a rotating section including a rotary mirror, and a support member on which the rotary mirror is supported so as to be rotatable about a fixed axis of rotation; driving means for rotating said rotary mirror about said fixed axis of rotation; a rotary electrode mounted on said rotary section so as to rotate about said axis with said rotary mirror; a fixed electrode disposed close to the rotary electrode and generally parallel thereto, one of said rotary electrode and said fixed electrode having a plurality of portions spaced from one another on opposite sides of said axis of rotation of said rotary mirror; a fixing section to which said support member and said fixed electrode are mounted; and detecting means for detecting at least two electrostatic capacities or changes thereof between said plurality of portions of said one of said rotary and said fixed electrodes and the other electrode, respectively.
Claim 2
Dependent Claim
156 words
A mirror driving apparatus comprising: a rotating section including a rotary mirror, and a support member on which the rotary mirror is supported so as to be rotatable about a fixed axis of rotation; driving means for rotating said rotary mirror about said fixed axis of rotation; a rotary electrode mounted on said rotary section so as to rotate about said axis with said rotary mirror; a fixed electrode disposed close to the rotary electrode and generally parallel thereto, one of said rotary electrode and said fixed electrode having a plurality of portions spaced from one another on opposite sides of said axis of rotation of said rotary mirror; a fixing section to which said support member and said fixed electrode are mounted; and detecting means for detecting at least two electrostatic capacities or changes thereof between said plurality of portions of said one of said rotary and said fixed electrodes and the other electrode, respectively.
Claim 3
Dependent Claim
23 words
A mirror driving apparatus as claimed in claim 1, wherein one of said rotary electrode and said fixed electrode includes a charging film.
Claim 4
Dependent Claim
50 words
A mirror driving apparatus as claimed in claim 1, wherein said fixed electrode is so disposed as to become closest to said rotary electrode when said rotary mirror has been rotated a predetermined amount from an initial stationary position whereat the mirror rests when not driven by said driving means.
Claim 5
Dependent Claim
16 words
A mirror driving apparatus as claimed in claim 1, wherein said support member is electrically conductive.
Claim 6
Dependent Claim
17 words
A mirror driving apparatus as claimed in claim 1, wherein said driving means includes a magnetic circuit.
Claim 7
Dependent Claim
21 words
A mirror driving apparatus as claimed in claim 1, wherein said driving means includes a driving coil and a magnetic circuit.
Claim 8
Dependent Claim
27 words
A mirror driving apparatus as claimed in claim 1, wherein said support member is a plate spring which biases said rotary mirror to a stationary center position.
Claim 9
Dependent Claim
145 words
A mirror driving apparatus comprising: a rotary mirror supported in the apparatus so as to be rotatable about a fixed axis of rotation extending along a longitudinal center line of the mirror dividing the mirror in half; a rotary electrode integral with said rotary mirror so as to rotate therewith; a fixed electrode fixed in the apparatus and confronting said rotary electrode such that a distance between said rotary electrode and said fixed electrode varies as said rotary mirror rotates about said fixed axis, at least one of said fixed and said rotary electrodes having a plurality of portions spaced from one another on opposite sides of said fixed axis of rotation; and detecting means for detecting electrostatic capacities or changes thereof between said plurality of portions of said at least one of said fixed and said rotary electrodes and the other of said electrodes.
Claim 10
Dependent Claim
145 words
A mirror driving apparatus comprising: a rotary mirror supported in the apparatus so as to be rotatable about a fixed axis of rotation extending along a longitudinal center line of the mirror dividing the mirror in half; a rotary electrode integral with said rotary mirror so as to rotate therewith; a fixed electrode fixed in the apparatus and confronting said rotary electrode such that a distance between said rotary electrode and said fixed electrode varies as said rotary mirror rotates about said fixed axis, at least one of said fixed and said rotary electrodes having a plurality of portions spaced from one another on opposite sides of said fixed axis of rotation; and detecting means for detecting electrostatic capacities or changes thereof between said plurality of portions of said at least one of said fixed and said rotary electrodes and the other of said electrodes.
Claim 11
Dependent Claim
22 words
A mirror driving apparatus as claimed in claim 8, wherein one of said fixed and said rotary electrodes includes an electret film.
Claim 12
Dependent Claim
31 words
A mirror driving apparatus as claimed in claim 8, and further comprising a spring to which said rotary mirror is mounted, said spring being twistable about said fixed axis of rotation.
Claim 13
Dependent Claim
24 words
A mirror driving apparatus as claimed in claim 8, and further comprising drive means for rotating said mirror about said fixed axis of rotation.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-06-26 | 1998-12-26 | 1999-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-26 | 2002-12-26 | 2003-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-26 | 2006-12-26 | 2007-06-27 | $7700.00 | Window Closed / Lapsed |