Patent EP0247829A1 successfully refreshed from Google Patents.
EP0247829A1
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EP
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Method and apparatus for correcting loop gain of a fine adjustment servo loop
Assignee: Pioneer Corp
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Filing: 1987-05-26
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Granted: —
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Expires: 2007-05-26
Abstract
Abstract A servo loop particularly useful for a focusing or tracking servo in an optical disk. The peak-to-peak value of an error signal in the servo loop is detected while the optical pickup (8c) is being driven perpendicularly to the disk in focusing or transversely to the disk in tracking. The detected peak-to-peak value is used to adjust the gain of a variable gain amplifier (2) included in the servo loop.
Inventors
- 👤 Masanori c/o Pioneer Electronic Corp. Suzuki
- 👤 Kiyoshi C/O Pioneer Electronic Corp. Tateishi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 05:54
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/0941
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
68 words
A method of correcting the loop gain of a servo loop, comprising the steps of: opening a servo loop; detecting a peak-to-peak value of an error signal of said servo loop while said servo loop is open; adjusting an amplification gain in accordance with said detected peak-to-peak value; closing said servo loop; and operating said closed servo loop including amplifying said error signal by said adjusted amplication gain.
Claim 2
Independent Claim
68 words
A method of correcting the loop gain of a servo loop, comprising the steps of: opening a servo loop; detecting a peak-to-peak value of an error signal of said servo loop while said servo loop is open; adjusting an amplification gain in accordance with said detected peak-to-peak value; closing said servo loop; and operating said closed servo loop including amplifying said error signal by said adjusted amplication gain.
Claim 3
Dependent Claim
35 words
A method of correcting the loop gain as recited in Claim 1, further comprising the step of moving a mechanical component included in said servo loop in predetermined motion while said servo loop is opened.
Claim 4
Dependent Claim
45 words
A method of correcting the loop gain as recited in Claim 2, wherein said mechanical component is an optical pickup operatively connected with a rotating disk and wherein said predetermined motion is an approach of said pickup substantially perpendicularly to a surface of said disk.
Claim 5
Dependent Claim
43 words
A method of correcting the loop gain as recited in Claim 2, wherein said mechanical component is a pickup operatively connected with a rotating disk and wherein said predetermined motion is a motion of said pickup parallel to a surface of said disk.
Claim 6
Dependent Claim
54 words
A method of correcting the loop gain as recited in Claim 1, wherein said detecting step includes a step of determining a positive peak of said error signal and a step of determining a negative peak of said error signal, and wherein said peak-to-peak value is a difference of said positive and negative peaks.
Claim 7
Dependent Claim
34 words
A method of correcting the loop gain as recited in Claim 5, wherein said two determining steps each include a low-pass filtering step for filtering time variations of said positive and negative peaks respectively.
Claim 8
Independent Claim
93 words
An apparatus for correcting the loop gain of a servo loop, comprising: a servo loop including an error detection signal source, a variable gain amplifier receiving an output of said error detection signal source and switching means for opening and closing said servo loop; means for detecting a peak-to-peak value of said error detection signal while said switching means has opened said servo loop; means for setting a gain constant according to said detected peak-to-peak value; and means for controlling a gain of said variable gain amplifier according to said set gain constant.
Claim 9
Independent Claim
93 words
An apparatus for correcting the loop gain of a servo loop, comprising: a servo loop including an error detection signal source, a variable gain amplifier receiving an output of said error detection signal source and switching means for opening and closing said servo loop; means for detecting a peak-to-peak value of said error detection signal while said switching means has opened said servo loop; means for setting a gain constant according to said detected peak-to-peak value; and means for controlling a gain of said variable gain amplifier according to said set gain constant.
Claim 10
Dependent Claim
62 words
An apparatus for correcting the loop gain as recited in Claim 7, wherein said detecting means includes: positive determining means for determining a positive peak value of said error detection signal; negative determining means for determining a negative peak value of said error detection signal; and differencing means for producing said peak-to-peak value according to said determined positive and negative peak values.
Claim 11
Dependent Claim
34 words
An apparatus for correcting the loop gain as recited in Claim 8, further comprising two filtering means receiving respective outputs of said positive and negative determining means and providing inputs to said differencing means.
Claim 12
Dependent Claim
22 words
An apparatus as recited in Claim 7, further comprising a pickup operating upon a rotating disk and included in said servo loop.
Claim 13
Dependent Claim
27 words
An apparatus as recited in Claim 10, further comprising means for moving said pickup in a predetermined motion while said switching means have opened said servo loop.
Claim 14
Dependent Claim
29 words
An apparatus as recited in Claim 11, wherein said pickup is an optical pickup and said moving means moves said pickup substantially perpendicularly to a surface of said disk.
Claim 15
Dependent Claim
21 words
An apparatus as recited in Claim 12, wherein said moving means moves said pickup parallel to a surface of said disk.
References Cited (Backward Citations)
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