Dynamic information storage or retrieval – Control of storage or retrieval operation by a control... – Control of information signal processing channel
Reexamination Certificate
2000-12-27
2001-10-16
Tran, Thang V. (Department: 2651)
Dynamic information storage or retrieval
Control of storage or retrieval operation by a control...
Control of information signal processing channel
C369S047190
Reexamination Certificate
active
06304532
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a disk reproducing apparatus, and particularly to a disk reproducing technique suitable for use in reproducing data at an N time normal speed from a disk on which main information has been recorded together with a subcode of time information or the like, such as a digital audio disk.
There is a known example of data reproduction in which an intermittent access results when the information reading means is inadvertently moved by an external force or the like during N-time normal speed reproduction of a disk, where N is a positive integer. That is, as described in JP-A-62-150560 (Shibuya), digital audio data reproduced from a compact disk (CD) is written in a memory, but when the information reading means inadvertently skips over tracks, it is moved back to its previous position from which the skipping occurred. At this time, the writing of the data reproduced from the disk into the memory is stopped and the memory is read at a constant period of the sampling frequency. Thus, the digital-to-analog converted data can be continuously reproduced.
In this known method, during the period in which the information reading means is inadvertently moved, or skips over tracks and is then moved back to the original correct position, no noise occurs, and the reproduction is not interrupted, or abnormally carried out. However, data control is not performed for making data precisely continuous. This is because, although the subcode of time information is produced in time with the disk reading operation, the audio data is first written in a memory in order that the rotation irregularity of the disk can be absorbed, and is read thereafter under the control of a crystal oscillation frequency. Thus, the subcode and the audio data cannot be made precisely coincident in one-to-one correspondence.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a disk reproducing apparatus capable of precisely coordinating the subcode (e.g., sector member, time information, etc.) with the main information data in one-to-one correspondence and of making the data precisely continuous by use of the resulting main information data and subcode.
It is another object of the present invention to provide a disk reproducing apparatus in which the switching for the equalizer and clock reproduction is not necessary for the N-time normal speed output and the normal speed output because the subcode and the main information data are coincident in one-to-one correspondence, and because the data can be made continuous by use of the resulting main information data and subcode even when the data is read intermittently from the disk.
According to one feature of the present invention, there is provided a disk reproducing apparatus which includes processing means for demodulating modulated information data and a subcode read by the information reading means, making a certain process to detect or correct an error in the information data, and for producing the information data and the subcode; first memory means for storing the information data or the information and subcode from the processing means and for producing the information data; and first control means for controlling a write address and read address supplied to the first memory means; the processing means including second memory means for storing the information data and the subcode in order to absorb a rotation irregularity of the disk, and second control means for controlling a write address and read address supplied to the second memory means, the write address and read address supplied to the second memory means being generated from the second control means in order to deinterleave and read the information data which has been interleaved upon recording, so that a particular one of the information data and particular one of the subcode can be read in one-to-one correspondence.
According to another feature of the present invention, the first control means for controlling the write address and read address supplied to the first memory means includes first detecting means for detecting first sector information which indicates an address at which the information data is written in the first memory means from the subcode which is produced from the processing means through the second memory means; second detecting means for detecting second sector information which indicates an address at which the information data is read from the first memory means; third detecting means for detecting overflow and underflow of the data stored in the first memory means by comparing the detected first sector information and second sector information; third control means for inhibiting the first memory means from being written when the third detecting means detects an overflow and produces a resulting output; fourth control means for moving the reading means to a position of next data continuous to the previous data according to the first sector information when the first memory means is inhibited from being written; and fifth control means for releasing the first memory means from the write-inhibited state, thereby enabling the first memory means to be written when the third detecting means detects an underflow and produces a resulting output, wherein a first clock frequency for determining the speed at which a data is written in the first memory means corresponds to N times the normal speed, and a second clock frequency for determining the speed at which a data is read from the first memory means corresponds to the normal speed.
According to the above features of the present invention, since the processing means having the second control means is provided, the subcode can be written in and read from the second memory means, and the subcode and information data on the disk can be maintained to be matched with each other since the disk rotation irregularity can be absorbed from both the subcode and information data.
In addition, since the first control means and the first memory means are provided, the data reproduced from the disk which is rotating at N time normal speed can be buffered and the reproduced data can be continuously read from the memory means at the normal speed.
REFERENCES:
patent: 4536864 (1985-08-01), Van Rosmalen
patent: 4656525 (1987-04-01), Norris
patent: 4712141 (1987-12-01), Tomohisa et al.
patent: 4905095 (1990-02-01), Yamada
patent: 5057923 (1991-10-01), Matsuda
patent: 5097459 (1992-03-01), Yoshio
patent: 5099464 (1992-03-01), Maeda
patent: 5130816 (1992-07-01), Yoshio
patent: 5134598 (1992-07-01), Nagano
patent: 5159143 (1992-10-01), Emi et al.
patent: 5166804 (1992-11-01), Takahashi
patent: 5214717 (1993-05-01), Kimura et al.
patent: 5221976 (1993-06-01), Dash et al.
patent: 5224089 (1993-06-01), Matsumura et al.
patent: 5253118 (1993-10-01), Konno
patent: 5291467 (1994-03-01), Ishiwata et al.
patent: 5317553 (1994-05-01), Ohga et al.
patent: 5345433 (1994-09-01), Ohga et al.
patent: 5361263 (1994-11-01), Urbansky
patent: 5390052 (1995-02-01), Kato et al.
patent: 5453964 (1995-09-01), Shimizume
patent: 5463607 (1995-10-01), Roth et al.
patent: 5553041 (1996-09-01), Inagawa et al.
patent: 5596558 (1997-01-01), Arataki et al.
patent: 0249781 (1987-12-01), None
patent: 0260722 (1988-03-01), None
patent: 0400810 (1990-12-01), None
patent: 0440224 (1991-08-01), None
patent: 0553841 (1993-08-01), None
patent: 0563922 (1993-10-01), None
patent: 62150560 (1987-07-01), None
patent: 3207056 (1991-09-01), None
patent: 4360067 (1992-12-01), None
patent: 696529 (1994-04-01), None
Kimura Izumi
Nishioka Munehiro
Tadokoro Hiroshi
Takeuchi Toshifumi
Antonelli Terry Stout & Kraus LLP
Hitachi , Ltd.
Tran Thang V.
LandOfFree
Disk reproducing apparatus controlling read signal from a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Disk reproducing apparatus controlling read signal from a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Disk reproducing apparatus controlling read signal from a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2563623