US5175545A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data coding system in a magnetic recording apparatus
Assignee: Hitachi Ltd
•
Filing: 1989-01-17
•
Granted: 1992-12-29
•
Expires: 2009-01-17
Abstract
Abstract A digital code conversion system in a magnetic recording apparatus for converting one bit of an input digital signal into a signal of two bits, in which the number of binary digits of "0" making appearance between adjacent binary digits of "1" is two at minimum and seven at maximum. In the digital code resulting from the code conversion, ratio between maximum and minimum values of the density at which the binary digit of "1" makes appearance is 1:2.
Inventors
- 👤 Takamasa Uchiyama
- 👤 Tadahiko Kameyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:22
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/14; G11B20/1403; G11B20/1423; G11B20/1426; H; H03; H03M; H03M5/00; H03M5/02; H03M5/04; H03M5/14; H03M5/145
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
163 words
A data encoding device for a magnetic recording apparatus comprising: means for inputting original data, said original data comprising a plurality of digital bits; means for storing a state transition table which accepts original data and current state data and outputs coded data and next state data based on said original data, said current state data, and contents of said state transition table; means for accepting and storing said next state data and for later providing the stored data as current state data to said means for storing a state transition table; and means for supplying a coded data to a recording head, wherein said means for storing a transition table converts said original data such that one of binary digits "1" and "0" occurs in a number of two at minimum and seven at maximum between adjacent ones of the other binary digits wherein a ratio between maximum and minimum values of density at which said other binary digit appears is 2:1.
Claim 2
Dependent Claim
163 words
A data encoding device for a magnetic recording apparatus comprising: means for inputting original data, said original data comprising a plurality of digital bits; means for storing a state transition table which accepts original data and current state data and outputs coded data and next state data based on said original data, said current state data, and contents of said state transition table; means for accepting and storing said next state data and for later providing the stored data as current state data to said means for storing a state transition table; and means for supplying a coded data to a recording head, wherein said means for storing a transition table converts said original data such that one of binary digits "1" and "0" occurs in a number of two at minimum and seven at maximum between adjacent ones of the other binary digits wherein a ratio between maximum and minimum values of density at which said other binary digit appears is 2:1.
Claim 3
Dependent Claim
35 words
A data coding system according to claim 1 wherein said other binary digits make appearance in a number of at least three bits in eighteen consecutive bits of the binary code resulting from said conversion.
Claim 4
Dependent Claim
22 words
A data coding system according to claim 2, wherein said other binary digit is "1" and said one binary digit is "0".
Claim 5
Dependent Claim
23 words
A data coding system according to claim 1, wherein said other binary digit is "1" and said one binary digit is "0" .
Claim 6
Dependent Claim
97 words
A data coding system in a magnetic recording apparatus for converting two bits of a binary digital data into three bits of a run length limited code in which one of binary digits "1" and "0" occurs in a number of one at minimum and seven at maximum between adjacent ones of the other binary digits and in which among various run length patterns including four run lengths, the run length patterns of "6-1-1-6" and "7-1-1-7" with which error is likely to take place in a signal read out upon data reproduction are inhibited from making appearance.
Claim 7
Dependent Claim
97 words
A data coding system in a magnetic recording apparatus for converting two bits of a binary digital data into three bits of a run length limited code in which one of binary digits "1" and "0" occurs in a number of one at minimum and seven at maximum between adjacent ones of the other binary digits and in which among various run length patterns including four run lengths, the run length patterns of "6-1-1-6" and "7-1-1-7" with which error is likely to take place in a signal read out upon data reproduction are inhibited from making appearance.
Claim 8
Dependent Claim
53 words
A data coding system according to claim 5, wherein among the various run length patterns constituted by four run lengths, the run length patterns in which occurrence of the maximum run length and the minimum length changes most remarkably are limited up to the run length patterns of "6-1-1-5" and "7-1-1-4" inclusive thereof.
Claim 9
Dependent Claim
22 words
A data coding system according to claim 5, wherein said other binary digit is "1" and said one binary digit is "0".
Claim 10
Dependent Claim
22 words
A data coding system according to claim 6, wherein said other binary digit is "1" and said one binary digit is "0".
Claim 11
Dependent Claim
78 words
A digital signal conversion system in a magnetic recording apparatus for converting one bit of an input digital signal into a signal of two bits, in which the number of binary digits of "0" making appearance between adjacent binary digits of "1" is two at minimum and seven at maximum, wherein in the digital signal resulting from the conversion, ratio between maximum and minimum values of density at which said binary digit of "1" makes appearance is 1:2.
Claim 12
Dependent Claim
78 words
A digital signal conversion system in a magnetic recording apparatus for converting one bit of an input digital signal into a signal of two bits, in which the number of binary digits of "0" making appearance between adjacent binary digits of "1" is two at minimum and seven at maximum, wherein in the digital signal resulting from the conversion, ratio between maximum and minimum values of density at which said binary digit of "1" makes appearance is 1:2.
Claim 13
Dependent Claim
112 words
A digital signal conversion system in a magnetic recording apparatus for converting two bits of an input digital signal into a signal of three bits, in which the number of binary digits of "0" making appearance between adjacent binary digits of "1" is one at minimum and seven at maximum, wherein in a digital code block of four run lengths in a digital signal resulting from the code conversion, the run length pattern in which occurrence of the maximum and minimum numbers of the binary digits of "0" between said adjacent binary digits of "1" changes most remarkably are limited up to the run length patterns of "6-1-1-5" and "7-1-1-4" inclusive thereof.
Claim 14
Dependent Claim
112 words
A digital signal conversion system in a magnetic recording apparatus for converting two bits of an input digital signal into a signal of three bits, in which the number of binary digits of "0" making appearance between adjacent binary digits of "1" is one at minimum and seven at maximum, wherein in a digital code block of four run lengths in a digital signal resulting from the code conversion, the run length pattern in which occurrence of the maximum and minimum numbers of the binary digits of "0" between said adjacent binary digits of "1" changes most remarkably are limited up to the run length patterns of "6-1-1-5" and "7-1-1-4" inclusive thereof.
Claim 15
Dependent Claim
74 words
A magnetic recording and reproducing apparatus comprising: a clock pulse generating circuit; means for providing original binary data; a magnetic head, controlled by a binary input signal and having a magnetic field, wherein said magnetic field is inverted at various intervals in response to a binary signal "1" in the binary input signal; means for decreasing variation in the intervals; and means for preventing the intervals from becoming less then a predetermined minimum value.
Claim 16
Dependent Claim
74 words
A magnetic recording and reproducing apparatus comprising: a clock pulse generating circuit; means for providing original binary data; a magnetic head, controlled by a binary input signal and having a magnetic field, wherein said magnetic field is inverted at various intervals in response to a binary signal "1" in the binary input signal; means for decreasing variation in the intervals; and means for preventing the intervals from becoming less then a predetermined minimum value.
Claim 17
Dependent Claim
83 words
The magnetic recording and reproducing apparatus of claim 11 wherein, said means for decreasing variation in the intervals maintains a ratio of 2:1 between the maximum and minimum density values of "1" in the input binary data and said means for preventing the intervals from becoming less then a predetermined minimum value converts each bit of the original binary data into two bits thereby creating input binary data having a minimum of two "0"s and a maximum of seven "0"s between adjacent "1"s.
Claim 18
Dependent Claim
37 words
The magnetic recording and reproducing apparatus of claim 12 wherein, a single means comprises said means for decreasing variation in the intervals and said means for preventing the intervals from becoming less than a predetermined minimum value.
Claim 19
Dependent Claim
35 words
The magnetic recording and reproducing apparatus of claim 13 wherein: said clock pulse generating circuit generates a clock pulse signal in phase with a pulse signal corresponding to magnetic field inversions of the magnetic head.
Claim 20
Dependent Claim
19 words
The magnetic recording and reproducing apparatus of claim 13 wherein, the binary values of "0" and "1" are inverted.
Claim 21
Dependent Claim
35 words
The magnetic recording and reproducing apparatus of claim 12 wherein: said clock pulse generating circuit generates a clock pulse signal in phase with a pulse signal corresponding to magnetic field inversions of the magnetic head.
Claim 22
Dependent Claim
19 words
The magnetic recording and reproducing apparatus of claim 12 wherein, the binary values of "0" and "1" are inverted.
Claim 23
Dependent Claim
77 words
A magnetic recording and reproducing apparatus comprising: a clock pulse generating circuit; means for providing original binary data; a magnetic head, controlled by a binary input signal and having a magnetic field, said magnetic field is inverted at various intervals in response to a binary signal "1" in the binary input signal; means for decreasing the length of the intervals; and means for inhibiting the binary input signal from having run length patterns of "6-1-1-6" and "7-1-1-7".
Claim 24
Dependent Claim
77 words
A magnetic recording and reproducing apparatus comprising: a clock pulse generating circuit; means for providing original binary data; a magnetic head, controlled by a binary input signal and having a magnetic field, said magnetic field is inverted at various intervals in response to a binary signal "1" in the binary input signal; means for decreasing the length of the intervals; and means for inhibiting the binary input signal from having run length patterns of "6-1-1-6" and "7-1-1-7".
Claim 25
Dependent Claim
51 words
The magnetic recording and reproducing apparatus of claim 18 wherein, said means for decreasing the length of the intervals converts every two bits of the original binary data into three bits thereby creating a binary signal having a minimum of one "0" and a maximum of seven "0"s between adjacent "1"s.
Claim 26
Dependent Claim
41 words
The magnetic recording and reproducing apparatus of claim 19 wherein, a single means comprises said means for decreasing the length of the intervals and said means for inhibiting the binary input signal from having run length patterns of "6-1-1-6" and "7-1-1-7".
Claim 27
Dependent Claim
35 words
The magnetic recording and reproducing apparatus of claim 20 wherein: said clock pulse generating circuit generates a clock pulse signal in phase with a pulse signal corresponding to magnetic field inversions of the magnetic head.
Claim 28
Dependent Claim
19 words
The magnetic recording and reproducing apparatus of claim 20 wherein, the binary values of "1" and "0" are inverted.
Claim 29
Dependent Claim
35 words
The magnetic recording and reproducing apparatus of claim 19 wherein: said clock pulse generating circuit generates a clock pulse signal in phase with a pulse signal corresponding to magnetic field inversions of the magnetic head.
Claim 30
Dependent Claim
19 words
The magnetic recording and reproducing apparatus of claim 19 wherein, the binary values of "1" and "0" are inverted.
References Cited (Backward Citations)
US4413251A
Cited
JPS58119273A
Cited
US4463344A
Cited
US4488142A
Cited
US4484176A
Cited
US4684921A
Cited
US4688016A
Cited
US4868922A
Cited
US4866544A
Cited
US4914438A
Cited
US4881076A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-12-29 | 1996-06-29 | 1996-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-12-29 | 2000-06-29 | 2000-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-12-29 | 2004-06-29 | 2004-12-29 | $7700.00 | Window Closed / Lapsed |