Method and system for converting binary data using bit-divided encoding

• US 4,652,942 A
• Filed: 07/19/1985
• Issued: 03/24/1987
• Est. Priority Date: 09/19/1984
• Status: Expired due to Fees

• Current Assignee: Hitachi Denshi Kabushiki Kaisha, Hitachi, Ltd.
• Original Assignee: Hitachi Denshi Kabushiki Kaisha, Hitachi, Ltd.
• Inventors: Eto, Yoshizumi
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/756,668
• Time in Patent Office: 613 Days
• Field of Search: 360/40, 360/32, 360/33.1, 375/17-19, 340/347 DD
• US Class Current: 386/232
• CPC Class Codes: G11B 20/1426 conversion to or from block codes or representations thereof
• CPC Class Codes: H04N 5/926 by pulse code modulation H04N5/919 takes precedence

Abstract

A video signal to be recorded on a recording medium used in a video tape recorder or optical disk recorder is digitized, distributed into several bit sets, and then subjected to separate processings or converting operations. The bit sets are merged into a data word with the same number bits as of the original digital data and, after being processed for bit inversion at a certain data interval, it is recorded on the recording medium. Data words retrieved from the recording medium are processed for bit inversion and inverse conversion in a reverse order with respect to the recording process, and a high quality video signal including a smaller number of bit errors can be reproduced.

Claims

1. A binary data conversion method for converting a highly redundant signal having a plurality of data words comprising the steps of:

(a) dividing individual data words into a plurality of bit sets;

(b) independently converting each of said plurality of bit sets derived from said data words;

(c) merging said plurality of converted bit sets into a plurality of new data words; and

(d) inverting the polarities of selective ones of said plurality of new data words.

2. A binary data conversion method according to claim 1, wherein said converting step comprises the steps of distributing each of said data words into a high-order bit set and a low-order bit set, converting said high-order bit sets into other bit sets by rearranging bit strings so as to have a digital sum which varies monotonically with the variation of the magnitude of said bit sets, and converting said low-order bit sets into still other bit sets by rearranging bit strings so as to have a digital sum which varies with a sinusoidal profile with the variation of the magnitude of said bit sets.

3. A binary data conversion method according to claim 1, wherein said plurality of autocorrelative data words are derived from a line-scanned video signal through a digitizing process and said data words produced by said polarity inverting process are recorded with a magnetic tape recorder.

4. A binary data conversion method according to claim 1, wherein each of said original data words is an 8-bit code which is split into two 4-bit codes, said polarity inversion taking place at every bit of said merged data words.

5. A digital recording method for a video signal comprising the steps of:

(a) digitizing a line-scanned video signal into data words each made up of high-order and low-order bit sets;

(b) converting said high-order bit set into a code with the digital sum thereof varying monotonically with the variation of the magnitude of the decimal notation of said high-order bit set;

(c) converting said low-order bit set into another code with the digital sum thereof varying with a sinusoidal profile with the variation of the magnitude of the decimal notation of said low-order bit set;

(d) merging said converted high-order and low-order bit sets; and

(e) inverting every bit of said merged data words at every other word.

6. A video signal recording system comprising:

(a) a first device which receives a high-order bit set of a binary video data and converts said bit set into a code with the digital sum thereof varying monotonically with the variation of the magnitude of the decimal notation of said high-order bit set;

(b) a second device which receives a low-order bit set of said binary video data and converts said bit set into a code with the digital sum thereof varying along a sinusoidal curve with the variation of the magnitude of the decimal notation of said low-order bit set;

(c) a third device which inverts bits of said converted high-order and low-order bit sets at every other data word; and

(d) a fourth device for recording said data words produced by said third device onto a recording medium.

7. A video signal recording system according to claim 6 further comprising a fifth device for inverting bits of data words retrieved from said recording medium at every other data words, and a sixth device which receives data from said fifth device and performs conversion for the high-order and low-order bit sets in a reverse manner with respect to the code conversions by said first and second devices.

8. A video signal recording system according to claim 6, wherein said second device includes means for transforming said low-order bit set having sixteen binary values from 0000 to 1111 corresponding to decimal 0 to 15, respectively into binary values 1010, 1100, 1101, 1110, 1111, 1011, 0111, 1001, 0110, 1000, 0100, 0000, 0001, 0010, 0011, 0101, respectively.