AU666684B2 - Circuit for detecting unrecorded portion of recording medium - Google Patents
Circuit for detecting unrecorded portion of recording medium Download PDFInfo
- Publication number
- AU666684B2 AU666684B2 AU29572/92A AU2957292A AU666684B2 AU 666684 B2 AU666684 B2 AU 666684B2 AU 29572/92 A AU29572/92 A AU 29572/92A AU 2957292 A AU2957292 A AU 2957292A AU 666684 B2 AU666684 B2 AU 666684B2
- Authority
- AU
- Australia
- Prior art keywords
- signal
- unrecorded portion
- recording medium
- sync
- window
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
- G11B19/02—Control of operating function, e.g. switching from recording to reproducing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
- G11B15/02—Control of operating function, e.g. switching from recording to reproducing
- G11B15/05—Control of operating function, e.g. switching from recording to reproducing by sensing features present on or derived from record carrier or container
- G11B15/087—Control of operating function, e.g. switching from recording to reproducing by sensing features present on or derived from record carrier or container by sensing recorded signals
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
- G11B19/02—Control of operating function, e.g. switching from recording to reproducing
- G11B19/04—Arrangements for preventing, inhibiting, or warning against double recording on the same blank or against other recording or reproducing malfunctions
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
- G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
- G11B27/19—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier
- G11B27/22—Means responsive to presence or absence of recorded information signals
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
- G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
- G11B27/19—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier
- G11B27/28—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording
- G11B27/30—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording on the same track as the main recording
- G11B27/3027—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording on the same track as the main recording used signal is digitally coded
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
- G11B27/36—Monitoring, i.e. supervising the progress of recording or reproducing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B2220/00—Record carriers by type
- G11B2220/20—Disc-shaped record carriers
Description
AF! A??9?97?2 a PCT) (Si) International Patent Classification 5: (11) International Publication Number: WO 94/12982 G11 2/28 1/0, 502Al(43) International Publication Date: 9 June 1994 (09.06.94) (21) International Application Number: PCT/KR92/00070 (81) Designated States: AU, CA, GB, J, US.
(22) International Filing Date: 30 November 1992 (30.11.92) Published With international search report.
(71) Applicant (for all designated States except US): SAMSUNG ELECTRONICS CO., LTD. [KR/KR]; 416, Mactan-dong, Kwonsun-ku, suwon, Kyungki-do 441-742 (KR).
(72) Inventor; and ieV Inventor/Applicant (for US only): LEE, Kwang, VHcui [KR/KR]; 5-505, Samsung 1st Apartment, Mactan 1-dong, Kwonsun-ku, Suwon, Kyungki-do 441-371 (KR).
(74) Agent: LEE, Young, P11; 2nd and 3rd floors, Cheonghwa Building, 1571-18, Scocho-dorog, Seocho-ku, Seoul 137-073
(KR).
(54) Title: CIRCUIT FOR DETECTING UNRECORDED PORTION OF RECORDING MEDIUM 1 INPUT i 100 READ/ __ISN
WRITE
I I SIGNAL
SIGNAL
I 500w 200 D DO I400 2 0 CLR ~WINDOW
SIGNAL.
L (5)Absftrct66 6 4267f2 Disclosed is a circuit for detecting an unrecorded portion in a recording medium, which comprises a window counting portion for receiving an input signal to recognize if the input signal comes from an ucecorded portion of the recording medium and counting a predetermined time to generate a window pulse signal, and a sync signal generator (20) which is enabled by the window pulse signal, in which if the number of pulses of the input signal is not less than a predetermined number, the generator recognizes the current input signal comes from a data region of the recording medium to simultaneously generate a sync signal, while if the number of pulses of the input signal is not more than a predetermined number of pulses, the generator recognizes the current input signal comes from an unrecorded region of the recording mediumn, not to generate the sync signal. The unrecorded portion is accurately detected not to generate a sync signal due to noise included in the unrecorded portion of the recording medium.
FOR THE PURPOSES OF INFORMATION ONLY Codes used to identify Sutt% party to the PCT on the front pages of pamphlets publishing international applications under the PCT.
Ii
LI
AT
AU
BB
HE
BF
DO
BJ
DR
DY
CA
CF
CG
C9
CI
Cm
CN
CS
CZ
DE
OK
F1
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GA
Austria Australia Barbados Belgium Burkina Faso Bulgea Benin Brazil Belarus Central Aficmn Republic Congo Switzerland C8te d'Ivoire Cameroon Cina Czechoslovakia Czech Republic Germany Finland Gabon United Kingdom Georgia Guln Greece Hungary Ireland Italy Japan Kenya Kyrgystan Democratic People's Republic of Korea Republic of Korea Kozakbstan Liechtenstein SriL.anka I.Altembourg LArvia Monaco Republic of Moldova Madagascar Mali Mongolia Mauritania Malawi Niger Netherlandsq Norway NewZaln Poland Pottuga Romania Ruzssian Federation Sudan Sweden Slovenia Slovaktia Senegal Chad Togo Tajiiuan Thoidad anid Tobago Ukraine United Staea of America Uzbekistan Viet Nam CIRCUIT FOR DETECTING UNRECORDED PORTION OF RECORDING
MEDIUM
TECHNICAL FIELD The present invention relates to magnetic storage devices and more particularly, to a circuit for detecting an unrecorded portion of a magnetic recording medium.
BACKGROUND ART In general, a magnetic recording medium includes a sector identification code for distinguishing one sector from another. In addition, unrecorded portions 1 0 are provided between respective sectors to separate one sector from the next.
It should be noted that, since noise can be generated in these unrecorded portions of the magnetic recording medium, an appropriate sync signal may not be generated at the exact starting point of a sector. That is, the noise generated in the unrecorded portion may be mistaken for the starting point of 1 5 a sector by the playback circuit, and, as a result, the sync signal may be generated in the unrecorded portion.
FIG. 1A represents the conventional data recording format of a hard disk.
In FIG. 1A, a post-amble portion exists from an end location ENDS of a sector to a starting point of an unrecorded portion DC-GAP, sequentially followed by an unrecorded portion, a pre-amble portion and a data portion of the next sector.
FIG. 1B shows the location where a normal sync signal should be generated when reading a conventional hard disk. As can be seen from the figure the normal sync signal is generated at a predetermined point of the pre-amble portion.
FIG. 2 shows the location where a sync signal is generated in reading a conventional hard disk when one or two noise pulses included in the unrecorded portion are mistaken for a data signal. Thus, a conventional unrecorded portion detecting circuit of the recording medium erroneously n.
U
-vZZ 2 generates a sync signal by recognizing as data pulses the noise pulses in the unrecorded portion of the recording medium.
DISCLOSI RE OF THE INVENTION Therefore, to solve the above problems, it is an object of the present invention to provide a circuit for detecting unrecorded portion of a recording medium in which, when an unrecorded portion is detected, a starting point of the sector is accurately detected by ignoring noise pulses, thereby generating a desired sync signal.
To accomplish the above object of the present invention, there is provided a 1 0 circuit for detecting an unrecorded portion of a recording medium, comprising: unrecorded portion recognition means for receiving an input signal read out from the recording medium and recognizing whether the input signal comes from the unrecorded portion thereof; enables signal generating means, which receives the output of said o 15 unrecorded portion recognition means, for generating an enable signal in response to the input signal; 0 window forming means enabled by the output of said enable signal generating means, for generating a window pulse signal with a predetermined pulse duration by counting a predetermined time in response to a 2 0 predetermined clock; and s sync signal generating means which is enabled by the window pulse signal, in which, if the number of pulses of the input signal is not less than a predetermined number, said sync signal generating means recognizes that a current input signal comes from a data region of the recording medium and 2 5 generates a sync signal, while, if the number of pulses of the input signal is not more ihan a predetermined number, said sync signal generating means recognizes that the current input signal comes from the unrecorded region of the recording medium, not to thereby generate the sync signal.
BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings: FIG. 1A represents a conventional data recording format for a hard 3 disk; FIG. 1lB shows the location where a sync signal should be generated in a conventional hard disk; FIG. 2 shows the location where a sync signal is in fact generated in a read operation of a conventional hard disk when one or two noise pulses included in the unrecorded portion are mistaken for data signals; FIG. 3 is a block diagram of one embodiment of an unrecorded portion detecting circuit according to the present invention; and FIG. 4 is a timing diagram for explaining the operation of the 1 0 unrecorded portion detecting circuit shown in FIG. 3.
BEST MODE FOR CARRYING OUT THE INVENTION The preferred embodiment of an unrecorded portion detecting circuit according to the present invention will be described below in more detail with reference to the accompanying drawings.
15 In FIG. 3, an unrecorded portion detecting circuit according to the present invention comprises a window counting portion 10 for a receiving read/write pulse signal, for recognizing whether the read/write signal with a *predetermined pleduration cmsfrom anunrecorded prinof a ;recording medium and for generating a window signal by counting a 2 0 predetermined time in response to a clock signal. The circuit also comprises a sync signal generator 20 which is enabled by the window counting portion for accurately generating a sync signal by determining if the number of pulses of the read/write signal is not less than a predetermined number of pulses.
Window counting portion 10 comprises unrecorded portion recognition device 100 for receiving the read/write signal and determining if the signal comes from the data region or the unrecorded region of the recording medium. It further includes a D-type flip-flop 200 which has a data input terminal D for receiving the output of the unrecorded portion recognition device 100 and a clock terminal for receiving the read/write signal, and window forming device 3 0 300 which has a clear terminal CLR for receiving the output of D-type flip-flop 200 and a clock terminal, wherein window forming device 300 is enabled by the clock signal and counts a predetermined time, so as to form a window by performing a transition of a pulse state.
A-A
TT
4 Sync signal generator 20 comprises a pulse counter/sync generator 400 having a clock terminal for receiving the read/write signal and a clear terminal cleared by the output of window forming device 300, thereby counting the number of pulses of the input signal, to accordingly generate a sync signal. It further includes an OR gate 500 for receiving the outputs of both unrecorded portion recognition device 100 and pulse counter/sync generator 400, to logically sum both the signals and to accordingly generate a sync signal.
FIG. 4 is a timing diagram for explaining the operation of the preferred embodiment of the unrecorded portion detecting circuit shown in FIG. 3.
1 0 In FIGs. 3 and 4, if the number of continuous pulses input is less than or equal to two, it is assumed that the input pulses are noise. Unrecorded portion recognition device 100 receives data which has bee read out from the magnetic recording medium and recognizes that the input signal comes from the unrecorded portion of the magnetic recording medium. D-type flip-flop 200 receives the output of unrecorded portion recognition device 100 and then, if the input signal is received through the clock terminal, a pulse is generated. Window forming means 300 counts a predetermined time in responsive to the system clock and generates the window pulse signal, if the output of D-type flip-flop 200 is input to the clear terminal CLR. Here, the 2 0 above predetermined time is a time during which three pulse signals can be input. As shown in Fig. 4, window forming means 300 detects the rising edge of a first noise pulse of the input signal included in the unrecorded portion tc 2 generate a rising edge of a window signal, and then counts a predetermined time to generate a falling edge of the window signal. Pulse counter/sync generator 400 generates a sync signal if the number of pulses of the signal input during an enabled period of the output of window forming device 300 is more than or equal to three, while pulse counter/sync generator 400 recognizes the input signal as noise so as not to generate the sync signal if the number of pulses of the signal input during the same period is less than or equal to two. That is, pulse counter/sync generator 400 detects a rising edge of the third pulse and generates a sync signal when it is determined that three pulses are input. Accordingly, logical summing device 500 outputs the sync signal only when the output of pulse counter/sync generator 400 is generated.
In this embodiment, the generated sync signal is generated slightly delayed from the desired sync signal. Thus, it is necessary to add a sync signal -1 4, correction circuit for synchronizing the sync signal appearing at the output side of logical summing device 500 shown in FIG. 3 to the desired sync signal timing. By doing so, correction of the sync signal is performed simply.
The above-described embodiment has been explained under the assumption that if only one or two pulses are input, the input pulses are noise. However, in other embodiments, both the window counting device and the sync signal generator may form window signals for measuring input signals equal to or exceeding a predetermined number of pulses, then count the number of the input pulses, and determine whether or not the input pulses are noise.
1 0 The above-described unrecorded portion detecting circuit according to the present invention counts the predetermined time to form the window pulse in window forming device 300, and generates the sync signal if a predetermined number of pulses or more are input within the counted interval in pulse counter/sync generator 400. Correspondingly, if fewer than the 1 5 predetermined number of pulses are input, they are determined to be noise and, as a result the sync signal is not generated.
As described above, the unrecorded portion detecting circuit according to the V present invention accurately detects the unrecorded portion of a recording medium by not generating a sync signal in response to noise included in the 2 0 unrecorded portion of the recording medium. Accordingly, the present invention can improve reliability of electronic products requiring accurate synchronization.
INDUSTRIAL
APPLICATION
S.The present invention can be widely applied in the field of the electronic S 2 5 household products in which signals are recorded and reproduced using recording media.
Claims (4)
1. A circuit for detecting an unrecorded portion of a recording medium, comprising: unrecorded portion recognition means for receiving an input signal read out from the recording medium and recognizing whether the input signal comes from the unrecorded portion thereof; enable signal generating means, which receives the output of said unrecorded portion recognition means, for generating an enable signal in response to the input signal; 1 0 window forming means enabled by the output of said enable signal generating means, for generating a window pulse signal with a predetermined pulse duration by counting a predetermined time in response to a predetermined clock; and sync signal generating means which is enabled by said window 1 5 pulse signal, in which if the number of pulses of the input signal is not less than a predetermined number, said sync signal generating means recognizes that a current input signal comes from a data region of the recording medium and genelates a sync signal, while if the number of pulses of the input signal o 0.I iis not more than a predetermined number, said sync signal generating means recognizes that the current input signal comes from the unrecorded region of the recording medium, and omits generating the sync signal.
2. The circuit for detecting an unrecorded portion of a recording medium according to claim i wherein said sync signal generating means comprises a pulse counter and sync generator which is enabled in response 25 to the window pulse signal of said window forming means for receiving the input signal and then generating a certain pulse signal if the predetermined number of pulses are input, and otherwise then omitting the generation of the certain pulse signal, and means for logical summing the outputs of both said unrecorded portion recognition means and said pulse counter and sync 3 0 generator to thereby generate the sync signal.
3. The circuit for detecting an unrecorded portion of a recording medium according to claim 1, wherein said unrecorded portion detection circuit further comprises sync signal corrector means for receiving the output of said sync signal generating means and for generating an accurate sync signal.
4. The circuit for detecting an unrecorded portion of a recording medium according to claim 2, wherein said window forming means detects a rising edge of a first noise pulse included in said unrecorded portion and generates the rising edge of the window pulse signal, and counts the predetermined time and then generates a falling edge of the window pulse signal. Dated this 30th day of November 1995 SAMSUNG ELECTRONICS CO., LTD. By their Patent Attorneys, COLLISON CO. 0 0 0 a e a4 0 *eo°! aooo *co°
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/KR1992/000070 WO1994012982A1 (en) | 1992-11-30 | 1992-11-30 | Circuit for detecting unrecorded portion of recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU2957292A AU2957292A (en) | 1994-06-22 |
| AU666684B2 true AU666684B2 (en) | 1996-02-22 |
Family
ID=19327580
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU29572/92A Ceased AU666684B2 (en) | 1992-11-30 | 1992-11-30 | Circuit for detecting unrecorded portion of recording medium |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP2955364B2 (en) |
| AU (1) | AU666684B2 (en) |
| GB (1) | GB2278226B (en) |
| WO (1) | WO1994012982A1 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3200150A1 (en) * | 1981-01-06 | 1982-07-15 | Pioneer Electronic Corp., Tokyo | DEVICE FOR CONTROLLING THE REPEAT SCAN FOR A MAGNETIC TAPE DEVICE |
| GB2234385A (en) * | 1989-07-10 | 1991-01-30 | Samsung Electronics Co Ltd | A reproduction circuit for a double-deck cassette apparatus |
| US5053896A (en) * | 1986-05-14 | 1991-10-01 | Canon Kabushiki Kaisha | Receiving method and apparatus for recording received data onto a recording medium |
-
1992
- 1992-11-30 AU AU29572/92A patent/AU666684B2/en not_active Ceased
- 1992-11-30 GB GB9406718A patent/GB2278226B/en not_active Expired - Fee Related
- 1992-11-30 JP JP6510426A patent/JP2955364B2/en not_active Expired - Lifetime
- 1992-11-30 WO PCT/KR1992/000070 patent/WO1994012982A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3200150A1 (en) * | 1981-01-06 | 1982-07-15 | Pioneer Electronic Corp., Tokyo | DEVICE FOR CONTROLLING THE REPEAT SCAN FOR A MAGNETIC TAPE DEVICE |
| US5053896A (en) * | 1986-05-14 | 1991-10-01 | Canon Kabushiki Kaisha | Receiving method and apparatus for recording received data onto a recording medium |
| GB2234385A (en) * | 1989-07-10 | 1991-01-30 | Samsung Electronics Co Ltd | A reproduction circuit for a double-deck cassette apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2955364B2 (en) | 1999-10-04 |
| JPH07503573A (en) | 1995-04-13 |
| WO1994012982A1 (en) | 1994-06-09 |
| GB9406718D0 (en) | 1994-08-31 |
| AU2957292A (en) | 1994-06-22 |
| GB2278226B (en) | 1996-05-22 |
| GB2278226A (en) | 1994-11-23 |
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