EP0485234A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Information recording and reproducing device
Assignee: Sharp Corp
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Filing: 1991-11-08
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Granted: —
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Expires: 2011-11-08
Abstract
Abstract An information recording and reproducing device has a first recording clock generation circuit (106) which generates a clock based on pre-recorded information on a magneto-optical disk (101), a second recording clock generation circuit (107) and a switching circuit (117). The switching circuit (117) selects a first recording clock (e) when recording information is of discrete information (j) and selects a second recording clock (f) when recording information is of successive information (i). Moreover, in the present device, a first reading clock (fr) is used as well as a second clock (fr′) as a clock for reading out the reproduced data from the magneto-optical disk (1), which had been once stored in memory (15). The second reading clock having a reference frequency is generated by a second clock generation circuit (11) and is used for reading out successive information such as music information. The first reading clock in synchronisation with the reproduced signal is generated by a first reading clock generation circuit (9) and is used for reading out discrete information such as computer-use data. In addition, in the case of discrete information, it is possible to start the recording/reproducing operation immediately after an optical head reaches a desired position, thereby permitting a shortened access time.
Inventors
- 👤 Shigemi Maeda
- 👤 Kunio Kojima
- 👤 Jun Akiyama
- 👤 Shigeo Terashima
- 👤 Tomiyuki Numata
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 03:47
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/14; G11B11/00; G11B11/10; G11B11/105; G11B11/10502; G11B11/10504; G11B11/10515; G11B11/1055; G11B11/10556; G11B11/10563; G11B19/00; G11B19/02; G11B19/12; G11B19/20; G11B19/24; G11B20/1403; G11B21/00; G11B21/02; G11B21/08; G11B21/081; G11B21/083; G11B21/085; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G11B27/32; G11B27/327; G11B7/00; G11B7/004; G11B7/08; G11B7/085; G11B7/08505; G11B2020/1087; G11B2020/10888; G11B2220/00; G11B2220/20; G11B2220/25; G11B2220/2525
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
54 words
An information recording and reproducing device employing a recording medium whereon pre-recorded information is formed including rotation control information for controlling a rotation at a constant linear velocity, comprising: first recording clock generation means for generating a first recording clock for signal processing in recording based on the pre-recorded information on the recording medium.
Claim 2
Dependent Claim
79 words
An information recording and reproducing device as set forth in claim 1, further comprising: second recording clock generation means for generating a second recording clock having a determined reference frequency; switching means for alternatively selecting either the first recording clock or the second recording clock; and control means for controlling a switching operation of said switching means based on distinctive information stored in a determined area of the recording medium, which determines whether recorded information is successive or discrete.
Claim 3
Dependent Claim
44 words
The information recording and reproducing device as set forth in claim 2, wherein said first recording clock generation means is designed so as to output a clock which is set in synchronization with the pre-recorded information in the reproduced signal by PLL circuit means.
Claim 4
Dependent Claim
38 words
The information recording and reproducing device as set forth in claim 2, wherein said second recording clock generation means is designed so as to output a recording clock having a reference frequency respective to the constant linear velocity.
Claim 5
Dependent Claim
176 words
An information recording and reproducing device employing a recording medium whereon pre-recorded information is formed including rotation control information for controlling a disk rotation at a constant linear velocity, comprising: an optical head; first recording clock generation means for generating a first recording clock for signal processing in recording which is in synchronization with the pre-recorded information in the reproduced signal and for outputting digital pre-recorded information; second recording clock generation means for generating a second recording clock having a same frequency as a recording clock responsive to the determined linear velocity; means for detecting a present address of the optical head means based on the digital pre-recorded information; switching means for alternatively selecting either the first recording clock or the second recording clock; and control means for controlling a switching operation based on distinctive information which determines whether information recorded on the recording medium is successive or discrete and for starting the recording operation after confirming that the optical head means has reached a target address based on an output from the address detection means.
Claim 6
Dependent Claim
65 words
The information recording and reproducing device as set forth in claim 5, wherein said first recording clock generation means comprises: filter means for separating the pre-recorded information from the reproduced signal; comparator means for digitalizing the pre-recorded information thus separated; PLL circuit means for inputting the digital pre-recorded information and for outputting the first recording clock which is in synchronization with the digital pre-recorded information.
Claim 7
Dependent Claim
60 words
The information recording and reproducing device as set forth in claim 5, wherein said second recording clock generation means comprises: reference clock generation means, which generates the second recording clock, for generating a clock having a frequency in response to the linear velocity under the CLV control; and dividing means for dividing an output from said reference clock generation means.
Claim 8
Dependent Claim
59 words
The information recording and reproducing device as set forth in claim 5, wherein said address detection means comprises a biphase-mark demodulator and an address decoder, and after demodulating in the form of "biphase-mark" the pre-recorded information extracted by the first recording clock generation means, outputs address information indicating positions on the recording medium by means of the address decoder.
Claim 9
Dependent Claim
169 words
A recording method of a recording medium whereon having formed pre-recorded information including rotation control information for controlling a rotation at a constant linear velocity, comprising the steps of: (a) determining whether recorded information is analog information or digital information; (b) moving the optical head means to a target address; (c) judging whether or not the optical head has reached the target address by detecting a present address of the optical head means; (d) recording by using a second recording clock having a determined reference frequency generated by the second recording clock generation means in the case of analog information immediately after confirming that the optical head has reached the target address in the step (c), while, for recording by using a recording clock generated in synchronism with the pre-recorded information in the reproduced signal from the optical head means by the first recording clock generation means in the case of digital information, immediately after confirming that the optical head has reached the target address in the step (c).
Claim 10
Dependent Claim
92 words
An information recording and reproducing device having memory means for storing reproduced data for the purpose of absorbing a time based deviation of the reproduced data from a recording medium, wherein the reproduced data is written in the memory means using a writing clock in synchronization with the reproduced data from the recording medium, comprising: first reading clock generation means for generating a first reading clock in synchronization with the reproduced data as a reading clock, wherein the reproduced data is read out from the memory means according to the reading clock.
Claim 11
Dependent Claim
85 words
The information recording and reproducing device as set forth in claim 10, further comprising: second reading clock generation means for generating a second reading clock having a determined reference frequency; switching means for alternatively selecting either the first reading clock or the second reading clock as the reading clock; and reading clock switch controlling means for controlling a switching operation of the switching means based on distinctive information which determines whether information recorded in the determined area on the recording medium is successive or discrete.
Claim 12
Dependent Claim
213 words
An information recording and reproducing device having memory means for storing reproduced data for the purpose of absorbing a time based deviation of the reproduced data from a recording medium, wherein the reproduced data is written in the memory means using a writing clock in synchronization with the reproduced data from the recording medium, comprising: optical head means; a reproduction amplifier means for amplifying and digitalizing the reproduced signal from said optical head means and for outputting the digital reproduced signal; pre-recorded information detection means for extracting the pre-recorded information from the reproduced signal; address detection means for detecting a present position of the optical head means based on the pre-recorded information thus extracted; first reading clock generation means for generating a first reading clock in synchronization with the reproduced data as a reading clock, for reading out the reproduced data from the memory means; second reading clock generation means for generating a second reading clock having a determined reference frequency; switching means for alternatively selecting either the first reading clock or the second reading clock as the reading clock; and control means for controlling a switching operation of said switching means based on distinctive information which determines whether information recorded on a determined area of the recording medium is successive or discrete.
Claim 13
Dependent Claim
76 words
The information recording and reproducing device as set forth in claim 12, wherein said first reading clock generation means comprises: first PLL circuit means for outputting a write address generation use clock based on the pre-recorded digital information from said reproduction amplifier means; dividing means for dividing frequency of the write address generation use clock; and second PLL circuit means for outputting a read address generation use clock based on an output from said dividing means.
Claim 14
Dependent Claim
174 words
A reproducing method of a recording medium whereon having formed pre-recorded information including rotation control information which is used to control a rotation at a constant linear velocity, comprising the steps of: (a) determining whether the recorded information is analog information or digital information; (b) moving the optical head means to a target address; (c) judging whether or not the optical head has reached the target address by detecting a present address of the optical head means; (d) reproducing by using the second reading clock having the determined reference frequency generated by the second reading clock generation means in the case of analog information immediately after confirming that the optical head has reached the target address in the step (c), while, for reproducing by using the first reading clock generated in synchronism with the pre-recorded information in the reproduced signal from the optical head means by the first reading clock generation means in the case of digital information, immediately after confirming that the optical head has reached the target address in the step (c).
Claim 15
Dependent Claim
63 words
A data storage device including a recording head adapted to record data on a recording medium, characterised in that, in use, data to be stored is supplied to the medium at a rate which is dependent upon the speed, at the time of storage, of the part of the medium at which the data is to be stored, relative to the recording head.
Claim 16
Dependent Claim
67 words
A data retrieval device including a reading head adapted to retrieve data from a recording medium, characterised in that, in use, data retrieved from the medium is both written in and read from a memory means at a rate which is dependent upon the speed, at the time of retrieval, of the part of the medium from which the data is retrieved, relative to the reading head.
References Cited (Backward Citations)
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