Track jump prediction control of memory mode

• US 5,430,703 A
• Filed: 06/07/1993
• Issued: 07/04/1995
• Est. Priority Date: 06/11/1992
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Haikawa, Yukihiko, Hosono, Yukiharu, Tsuji, Shigeki
• Primary Examiner(s): Epps, Georgia Y.
• Assistant Examiner(s): HINDI, NABIL Z
• Application Number:
  US08/072,453
• Time in Patent Office: 757 Days
• Field of Search: 369/60, 369/59, 369/48, 369/58, 369/54, 369/53, 369/47, 369/32, 369/44.27-44.29, 369/44.26, 369/44.32, 369/50
• US Class Current: 369/53.18
• CPC Class Codes: G11B 19/02 Control of operating function, e.g. switching from recording to reproducing
• CPC Class Codes: G11B 20/00007 Time or data compression or expansion audio compression based on psychoacoustics G10L19/00; data processing for reproducing audio data at different playback speeds G10L21/04; video compression H04N19/00; data compression per se H03M7/30
• CPC Class Codes: G11B 20/10527 Audio or video recording; Data buffering arrangements G11B20/12 - G11B20/18 take precedence
• CPC Class Codes: G11B 2220/2529 Mini-discs
• CPC Class Codes: G11B 27/005 Reproducing at a different information rate from the information rate of recording for television signals H04N5/783
• CPC Class Codes: G11B 27/105 of operating discs
• CPC Class Codes: G11B 27/329 on a disc [VTOC]

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.

Claims

1. 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.

2. 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.

3. 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.

4. 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.

5. A digital information reproducing apparatus as recited in claim 3 comprising a mini disk reproducing apparatus.