Variable cell width recording

Claim 2

Method of encoding binary numbers on a recording medium comprising the steps of: 1. generating alternate timing and data signals of first and second voltage levels, respectively, wherein each timing signal has a fixed time duration t and the data signals have variable time durations x, a first binary number is designated by x = at, a second binary number is designated by x = abt, and the absence of binary information is designated by x > abct, where a is a predetermined small number and each of b and c is a predetermined number appreciably exceeding one, and 2. serially recording the alternate timing and data signals along a track of the medium.

Claim 3

Method as defined in claim 1 wherein a is 1/2 to 2, b is 1.5 to 3, and c is 1.25 to 3.

Claim 4

Method as defined in claim 2 wherein a is about 1, b is about 2, and c is about 1.5.

Claim 5

Method as defined in claim 1 wherein step (1) further comprises generating (i) a predetermined number of consecutive timing and data signals of at and abt durations to represent a byte of binary information, (ii) a timing signal followed by a data signal exceeding abct duration to represent an inter-byte gap, and (iii) a timing signal followed by a data signal exceeding abcdt duration to represent the end of a message consisting of a series of bytes, where d is a predetermined number appreciably exceeding 1.

Claim 6

Method as defined in claim 4 wherein a is 1/2 to 2, b is 1.5 to 3, c is 1.25 to 5, and d is 2 to 8.

Claim 7

Method of encoding and decoding binary numbers on a recording medium comprising the steps of: 1. generating alternate timing and data signals of first and second voltage levels, respectively, wherein each timing signal has a fixed time duration t and the data signals have variable time durations x, a first binary number is designated by x = at, a second binary number is designated by x = abt and the absence of binary information is designated by x > abct, where a is a predetermined small number and each of b and c is a predetermined number appreciably exceeding one, 2. serially recording the alternate timing and data signals along a track of the medium, 3. playing back the recorded signals, 4. measuring the time interval t' of a played-back timing signal at a rate R 1 , 5. measuring the time interval x' of the succeeding played-back data signal at a rate R 2 = rR 1 , and 6. subtracting the x' measurement in step (5) from the t' measurement in step (4) and producing an output signal indicative of the first binary number when the difference is greater than a first quantity t = rn where n is a value intermediate at and abt, indicative of the second binary number when the difference is less than said first quantity and is greater than a second quantity t - r(abct), indicative of the absence of binary information when the difference is less than said second quantity.

Claim 8

Method of encoding and decoding binary numbers on a recording medium comprising the steps of: 1. generating alternate timing and data signals of first and second voltage levels, respectively, wherein each timing signal has a fixed time duration t and the data signals have variable time durations x, a first binary number is designated by x = at, a second binary number is designated by x = abt and the absence of binary information is designated by x > abct, where a is a predetermined small number and each of b and c is a predetermined number appreciably exceeding one, 2. serially recording the alternate timing and data signals along a track of the medium, 3. playing back the recorded signals, 4. measuring the time interval t' of a played-back timing signal at a rate R 1 , 5. measuring the time interval x' of the succeeding played-back data signal at a rate R 2 = rR 1 , and 6. subtracting the x' measurement in step (5) from the t' measurement in step (4) and producing an output signal indicative of the first binary number when the difference is greater than a first quantity t = rn where n is a value intermediate at and abt, indicative of the second binary number when the difference is less than said first quantity and is greater than a second quantity t - r(abct), indicative of the absence of binary information when the difference is less than said second quantity.

Claim 9

Method as defined in claim 6 wherein measuring step (4) involves counting up from zero during the interval t', step (5) involves counting down during the interval x' at a rate R 2 such that r is less t/a and greater than t/ab, and step (6) involves subtracting the count in step (5) from the count in step (4) and producing an output signal indicative of the first binary number when the countdown is positive, indicative of the second binary number when the countdown is negative while having an absolute magnitude less than a count-down equalling r(abct).

Claim 10

Method as defined in claim 6 wherein step (1) involves generating (i) a predetermined number of consecutive timing and data signals to represent a byte of binary information, (ii) a timing signal followed by a data signal having a predetermined time duration exceeding abct and less than abcdt to represent an inter-byte gap, d being a predetermined number appreciably exceeding 1, and (iii) a timing signal followed by a data signal having a predetermined time duration exceeeding abcdt to represent the end of a message consisting of a block of bytes, and step (6) involves producing an output signal indicative of an end-of-message gap when the difference is less than a third quantity t - r(abcdt).

Claim 11

Method as defined in claim 8, including the additional steps of 7. counting the bits in each byte, and 8. producing an error signal when the count differs from said predetermined number.

Claim 12

Apparatus for encoding binary numbers on a recording medium comprising: 1. means for generating alternate timing and data signals of first and second voltage levels, respectively, wherein each timing signal has a fixed time duration t and the data signals have variable time durations x, a first binary number is designated by x = at, a second binary number is designated by x = abt and the absence of binary information is designated by x > abct, where a is a predetermined small number and each of b and c is a predetermined number appreciably exceeding one, and 2. means for serially recording the alternate timing and data signals along a track.

Claim 13

Apparatus for encoding binary numbers on a recording medium comprising: 1. means for generating alternate timing and data signals of first and second voltage levels, respectively, wherein each timing signal has a fixed time duration t and the data signals have variable time durations x, a first binary number is designated by x = at, a second binary number is designated by x = abt and the absence of binary information is designated by x > abct, where a is a predetermined small number and each of b and c is a predetermined number appreciably exceeding one, and 2. means for serially recording the alternate timing and data signals along a track.

Claim 14

Apparatus for encoding and decoding binary numbers on a recording medium comprising: 1. means for generating alternate timing and data signals of first and second voltage levels, respectively, wherein each timing signal has a fixed time duration t and the data signals have variable time durations x, a first binary number is designated by x = at, a second binary number is designated by x - abt and the absence of binary information is designated by x > abct, where a is a predetermined small number and each of b and c is a predetermined number appreciably exceeding one, 2. means for serially recording the alternate timing and data signals along a track of the medium, 3. means for playing back the recorded signals, 4. means for measuring the time interval t' of each played-back timing signal at a rate R 1 , 5. means for measuring the time interval x' of each played-back data signal at a rate R 2 = rR 1 , and 6. means for subtracting the output of the x' measuring means (5) from the output of the t' measuring means (4) and for producing an output signal indicative of the first binary number when the difference is greater than a first quantity t - rn where n is a value intermediate at and abt, indicative of the second binary number when the difference is less than said first quantity and is greater than a second quantity t - r(abct), indicative of the absence of binary information when the difference is less than said second quantity.

Claim 15

Apparatus for encoding and decoding binary numbers on a recording medium comprising: 1. means for generating alternate timing and data signals of first and second voltage levels, respectively, wherein each timing signal has a fixed time duration t and the data signals have variable time durations x, a first binary number is designated by x = at, a second binary number is designated by x - abt and the absence of binary information is designated by x > abct, where a is a predetermined small number and each of b and c is a predetermined number appreciably exceeding one, 2. means for serially recording the alternate timing and data signals along a track of the medium, 3. means for playing back the recorded signals, 4. means for measuring the time interval t' of each played-back timing signal at a rate R 1 , 5. means for measuring the time interval x' of each played-back data signal at a rate R 2 = rR 1 , and 6. means for subtracting the output of the x' measuring means (5) from the output of the t' measuring means (4) and for producing an output signal indicative of the first binary number when the difference is greater than a first quantity t - rn where n is a value intermediate at and abt, indicative of the second binary number when the difference is less than said first quantity and is greater than a second quantity t - r(abct), indicative of the absence of binary information when the difference is less than said second quantity.

Claim 16

Apparatus as defined in claim 11 wherein said t' means means (4) includes means for counting up from zero during the interval t', said x' measuring means (5) includes means for counting down during the interval x' at a rate R 2 such that r is less than t/a and greater than t/ab, and said subtracting means (6) includes means for producing an output signal indicative of the first binary number when the countdown is positive, indicative of the second binary number when the countdown is negative while having an absolute magnitude less than a count-down equalling r(abct).

Claim 17

Apparatus as defined in claim 11 wherein generating means (1) includes means for generating (i) a predetermined number of consecutive timing and data signals to represent a byte of binary information, (ii) a timing signal followed by a data signal having a predetermined time duration exceeding abct and less than abcdt to represent an interbyte gap, d being a predetermined number appreciably exceeding one, and (iii) a timing signal followed by a data signal exceeding abcdt to represent the end of a message consisting of a block of bytes, and subtracting means (6) includes means for producing an output signal indicative of an end-of-message gap when the difference is less than a third quantity t - r(abcdt).

Claim 18

Apparatus as defined in claim 13 further including 7. means for counting the bits in each byte, and 8. means for producing an error signal when the count differs from said predetermined number.

Claim 19

Apparatus as defined in claim 11 for use with magnetic recording tape wherein the generating means (1) and the playing back means (3) are magnetic recording means.