US5430703A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Track jump prediction control of memory mode
Assignee: Sharp Corp
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Filing: 1993-06-07
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Granted: 1995-07-04
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Expires: 2013-06-07
Abstract
Abstract Audio sound data (compressed data) read by an optical pickup is temporarily held in a memory and the audio sound data is expanded to be returned to its original size. At the time of usual reproduction, since the difference in data transfer rates of reading by optical pickup and data expansion is absorbed, writing and reading of audio sound data are alternately performed using part of the memory capacity, while audio sound data is held by a fixed amount for data protection upon impact occurrence utilizing the remaining memory capacity. At the time of track jump, for example, if the moving distance of a head is long, all the memory capacity is used for data protection. If the moving distance of the head is short, part of the memory capacity is allocated according to the moving time, and the remaining memory capacity is used for data protection upon impact occurrence.
Inventors
- 👤 Shigeki Tsuji
- 👤 Yukihiko Haikawa
- 👤 Yukiharu Hosono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:30
CPC Classifications
G; G11; G11B; G11B19/00; G11B19/02; G11B20/00; G11B20/10; G11B20/10527; G11B27/00; G11B27/005; G11B27/10; G11B27/102; G11B27/105; G11B27/19; G11B27/28; G11B27/32; G11B27/327; G11B27/329; G11B20/00007; G11B2220/00; G11B2220/20; G11B2220/25; G11B2220/2525; G11B2220/2529
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
177 words
A digital information reproducing apparatus, comprising: reading means for reading compressed digital data from a storage medium; semiconductor memory means for temporarily holding the compressed data read by said reading means; data expansion means for expanding the compressed data held in said semiconductor memory means at a rate lower than the reading rate of the compressed data by said reading means in usual expansion; memory management means for allocating said semiconductor memory means for rate difference absorption for absorbing the difference between the reading rate of the compressed data by said reading means and said expansion processing rate of said data expansion means, and for compressed data protection when disturbance is generated; movement prediction means for predicting that said reading means is to move to another region on said storage medium; and control means for controlling said memory management means to use the entire memory capacity of said semiconductor memory means for said compressed data protection at the time of the movement of said reading means, if said prediction means predicts a movement of said reading means.
Claim 2
Dependent Claim
177 words
A digital information reproducing apparatus, comprising: reading means for reading compressed digital data from a storage medium; semiconductor memory means for temporarily holding the compressed data read by said reading means; data expansion means for expanding the compressed data held in said semiconductor memory means at a rate lower than the reading rate of the compressed data by said reading means in usual expansion; memory management means for allocating said semiconductor memory means for rate difference absorption for absorbing the difference between the reading rate of the compressed data by said reading means and said expansion processing rate of said data expansion means, and for compressed data protection when disturbance is generated; movement prediction means for predicting that said reading means is to move to another region on said storage medium; and control means for controlling said memory management means to use the entire memory capacity of said semiconductor memory means for said compressed data protection at the time of the movement of said reading means, if said prediction means predicts a movement of said reading means.
Claim 3
Dependent Claim
50 words
A digital information reproducing apparatus as recited in claim 1, wherein said storage medium includes storage means for storing data including the content of said storage medium and its address, and said prediction means predicts a movement of said reading means based on the data stored in said storage means.
Claim 4
Dependent Claim
272 words
A digital information reproducing apparatus, comprising: reading means for reading compressed digital data from a storage medium; semiconductor storage means for temporarily holding the compressed data read by said reading means; data expansion means for expanding the compressed data held in said semiconductor memory means at a rate lower than the reading rate by said reading means; memory management means for allocating said semiconductor memory for absorbing the difference between the reading rate of the compression data by said reading means and the expansion processing rate of the data expansion means at the time of usual reproduction, and for compressed data protection when an impact is effected; movement prediction means for predicting a movement of said reading means to a target track and its moving distance; movement time calculation means for calculating a time period necessary for the moving based on said moving distance; calculation means for calculating the longest expansion time period for said data expansion means to expand all the data of said semiconductor memory means; comparison means for comparing the moving time calculated by said moving time calculation means and the longest expansion time period; and control means responsive to the comparison result of said comparison means for controlling said memory management means to use all the storage capacity of said semiconductor memory in a first mode for protecting compressed data at the time of the movement of said reading means, when said moving time period is longer than said longest expansion time period, and to use the semiconductor memory device in said first mode and in a second mode for compressed data protection when an impact is effected.
Claim 5
Dependent Claim
272 words
A digital information reproducing apparatus, comprising: reading means for reading compressed digital data from a storage medium; semiconductor storage means for temporarily holding the compressed data read by said reading means; data expansion means for expanding the compressed data held in said semiconductor memory means at a rate lower than the reading rate by said reading means; memory management means for allocating said semiconductor memory for absorbing the difference between the reading rate of the compression data by said reading means and the expansion processing rate of the data expansion means at the time of usual reproduction, and for compressed data protection when an impact is effected; movement prediction means for predicting a movement of said reading means to a target track and its moving distance; movement time calculation means for calculating a time period necessary for the moving based on said moving distance; calculation means for calculating the longest expansion time period for said data expansion means to expand all the data of said semiconductor memory means; comparison means for comparing the moving time calculated by said moving time calculation means and the longest expansion time period; and control means responsive to the comparison result of said comparison means for controlling said memory management means to use all the storage capacity of said semiconductor memory in a first mode for protecting compressed data at the time of the movement of said reading means, when said moving time period is longer than said longest expansion time period, and to use the semiconductor memory device in said first mode and in a second mode for compressed data protection when an impact is effected.
Claim 6
Dependent Claim
50 words
A digital information reproducing apparatus as recited in claim 3, wherein said storage medium includes storage means for storing data including the content of said storage medium and its address, and said prediction means predicts a movement of said reading means based on the data stored in said storage means.
Claim 7
Dependent Claim
16 words
A digital information reproducing apparatus as recited in claim 3 comprising a mini disk reproducing apparatus.
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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) | 1998-07-03 | 1999-01-02 | 1999-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-03 | 2003-01-02 | 2003-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-03 | 2007-01-02 | 2007-07-04 | $7700.00 | Window Closed / Lapsed |