US4875112A — Compound pulse dimming circuitry for conditioning…

Claim 1

Independent Claim 91 words

Apparatus for conditioning pulse signals representing digital data, said apparatus comprising: delay line equalizer means for equalizing the pulse signals; and filter equalizer means coupled to said delay line equalizer means for complementally equalizing said pulse signals, and including a first path for filtering the pulse signals and to provide filtered pulses at an output, a second path for feeding forward a signal representing the time derivative of said filtered pulse signals at an output, and combining means for combining the signals at the output of the first and second paths.

Claim 2

Dependent Claim 91 words

Apparatus for conditioning pulse signals representing digital data, said apparatus comprising: delay line equalizer means for equalizing the pulse signals; and filter equalizer means coupled to said delay line equalizer means for complementally equalizing said pulse signals, and including a first path for filtering the pulse signals and to provide filtered pulses at an output, a second path for feeding forward a signal representing the time derivative of said filtered pulse signals at an output, and combining means for combining the signals at the output of the first and second paths.

Claim 3

Dependent Claim 21 words

Apparatus as in claim 1 wherein the first path includes a filter selected from the set consisting of low pass filters.

Claim 4

Dependent Claim 62 words

Apparatus as in claim 1 wherein said delay line equalizer means includes: first attenuator means for attenuating the pulse signals; first delay means for delaying pulse signals; second delay and attenuator means for delaying and attenuating pulse signals; and summing means for combining the pulse signals from the first attenuator means, the first delay means, and the second delay and attenuator means.

Claim 5

Dependent Claim 36 words

Apparatus as in claim 3 wherein the summing means includes means for subtracting the pulse signals from the first attenuator and the second delay and attenuator means from the pulse signals from the first delay means.

Claim 6

Dependent Claim 33 words

Apparatus as in claim 3 wherein the second delay means provides a delay of pulse signals which is equal to approximately twice the delay of pulse signals provided by the first delay means.

Claim 7

Dependent Claim 14 words

Apparatus as in claim 2 wherein each filter comprises at least a two-pole filter.

Claim 8

Dependent Claim 27 words

Apparatus as in claim 1 wherein the combining means includes means for adjusting the magnitude of the signals representing the time derivative combined with said filtered pulses.

Claim 9

Dependent Claim 14 words

Apparatus as in claim 1 wherein the time derivative is the second time derivative.

Claim 10

Dependent Claim 44 words

Apparatus as in claim 1 wherein the transfer function of the equalizer means is given by G.sub.3 =-A.sub.1 +e.sup.-D.sbsp.1.sup.s -A.sub.2 e.sup.-(D.sbsp.1.sup.+D.sub.2.sup.)s where s is the Laplace operator, D 1 and D 2 are delay factors and A 1 and A 2 are attenuation factors.

Claim 11

Dependent Claim 48 words

Apparatus as in claim 9 wherein the transfer function of the filter means is given by ##EQU3## where S=s/ω c , s is the Laplace operation, ω c is the corner frequency, a i are polynomial coefficients and k 2 is the coefficient for the second derivative component.

Claim 12

Independent Claim 112 words

A method for conditioning pulse signals representing digital data, said method comprising the steps of: equalizing the pulse signals; filtering the pulse signals for providing filtered pulse signals; deriving a signal representing the time derivative of said filtered pulse signals; and combining the filtered pulse signals and the signal representing the time derivative of said filtered pulse signals, said step of equalizing the pulse signals including the steps of: attenuating said pulse signals; delaying said pulse signals for a first delay; delaying said pulse signals for a second delay and attenuating them; and combining the first attenuated pulse signals, the first delayed pulse signals and the second delayed and attenuated pulse signals.

Claim 13

Independent Claim 112 words

A method for conditioning pulse signals representing digital data, said method comprising the steps of: equalizing the pulse signals; filtering the pulse signals for providing filtered pulse signals; deriving a signal representing the time derivative of said filtered pulse signals; and combining the filtered pulse signals and the signal representing the time derivative of said filtered pulse signals, said step of equalizing the pulse signals including the steps of: attenuating said pulse signals; delaying said pulse signals for a first delay; delaying said pulse signals for a second delay and attenuating them; and combining the first attenuated pulse signals, the first delayed pulse signals and the second delayed and attenuated pulse signals.

Claim 14

Dependent Claim 36 words

The method as in claim 11 wherein the step of combining includes the steps of subtracting the first attenuated pulse signals and the second delayed and further attenuated pulse signals from the first delayed pulse signals.

Claim 15

Dependent Claim 24 words

The method as in claim 11 wherein the magnitude of the second delay is approximately equal to twice the magnitude of the first delay.

Claim 16

Dependent Claim 28 words

The method as in claim 11 wherein the step of deriving a signal representing the time derivative includes the step of adjusting the magnitude of the time derivative.

Claim 17

Dependent Claim 25 words

The method as in claim 11 wherein the time derivative of said filtered pulse signals is the second time derivative of said filtered pulse signals.

Claim 18

Dependent Claim 69 words

Apparatus for conditioning pulse signals representing digital data, said apparatus comprising: at least two delay line equalizers for equalizing the pulse signals; and at least two pass filters coupled to said delay line equalizers for complementally equalizing said pulse signals, including means for deriving signals representing the second derivative of, and means for subtracting said second derivative signals from, the filtered pulse signals produced by said low pass filters.

Claim 19

Dependent Claim 69 words

Apparatus for conditioning pulse signals representing digital data, said apparatus comprising: at least two delay line equalizers for equalizing the pulse signals; and at least two pass filters coupled to said delay line equalizers for complementally equalizing said pulse signals, including means for deriving signals representing the second derivative of, and means for subtracting said second derivative signals from, the filtered pulse signals produced by said low pass filters.

Claim 20

Dependent Claim 22 words

Apparatus as in claim 16 wherein each of the low pass filters is a low pass filter having at least two poles.

Claim 21

Dependent Claim 40 words

Apparatus as in claim 16 wherein each of the low pass filters has multiple stages and the means for deriving the signal representing the second derivative of the filtered pulse signals is the last stage of the low pass filter.

Claim 22

Dependent Claim 31 words

Apparatus as in claim 18 wherein the last stage of the low pass filter includes an inductive impedance in series with the pulse signal path and a capacitive impedance to ground.

Claim 23

Dependent Claim 47 words

Apparatus as in claim 16 wherein the means for subtracting the signal representing the second derivative of the filtered pulse signals includes a feed-forward circuit for feeding forward the second derivative signals and an amplifier for receiving and subtracting the second derivative signals from said filtered pulse.

Claim 24

Dependent Claim 35 words

Apparatus as in claim 19 wherein the signal representing the second derivative of the filter pulse signals is derived from the voltage across said inductive impedance of said last stage of said low pass filter.

Claim 25

Dependent Claim 167 words

Apparatus for conditioning pulse signals representing digital data according to a transfer function of G 1 =G 2 G 3 , said apparatus comprising: delay line equalizer means for equalizing the pulse signals and having a transfer function of G 3 ; filter equalizer means coupled to said delay equalizer means complementally equalizing said pulse signals according to a transfer function of G 2 and including a first path for filtering the pulse signals and to provide filtered pulses at an output, a second path for feeding forward a signal representing the time derivative of said filtered pulse signals at an output, and combining means for combining the signals at the output of the first and second paths, where ##EQU4## s=s/ω c , is the Laplace operator, ω c is the corner frequency, a i are polynomial coefficients and k 2 is the coefficient for the second derivative component and D 1 and D 2 are delay factors and A 1 and A 2 are attenuation factors.

Claim 26

Dependent Claim 167 words

Apparatus for conditioning pulse signals representing digital data according to a transfer function of G 1 =G 2 G 3 , said apparatus comprising: delay line equalizer means for equalizing the pulse signals and having a transfer function of G 3 ; filter equalizer means coupled to said delay equalizer means complementally equalizing said pulse signals according to a transfer function of G 2 and including a first path for filtering the pulse signals and to provide filtered pulses at an output, a second path for feeding forward a signal representing the time derivative of said filtered pulse signals at an output, and combining means for combining the signals at the output of the first and second paths, where ##EQU4## s=s/ω c , is the Laplace operator, ω c is the corner frequency, a i are polynomial coefficients and k 2 is the coefficient for the second derivative component and D 1 and D 2 are delay factors and A 1 and A 2 are attenuation factors.

Claim 27

Dependent Claim 154 words

Apparatus for conditioning pulse signals representing digital data according to a transfer function of G T =[G 2 G 3 ] 2 , said apparatus comprising: at least two delay line equalizers for equalizing the pulse signals at each according to a transfer function G 3 ; and at least two low pass filters coupled to said delay line equalizer for complementally equalizing said pulse each according to a transfer G 2 pulse signals and including means for deriving signals representing the second derivative of, and means for subtracting said second derivative signals from, the filtered pulse signals produced by said low pass filters, where ##EQU5## s=s/ω c , s is the Laplace operator, ω c is the corner frequency, a 1 are polynomial coefficients and k 2 is the coefficient for the second derivative component and D 1 and D 2 are delay factors and A 1 and A 2 are attenuation factors.

Claim 28

Dependent Claim 154 words

Apparatus for conditioning pulse signals representing digital data according to a transfer function of G T =[G 2 G 3 ] 2 , said apparatus comprising: at least two delay line equalizers for equalizing the pulse signals at each according to a transfer function G 3 ; and at least two low pass filters coupled to said delay line equalizer for complementally equalizing said pulse each according to a transfer G 2 pulse signals and including means for deriving signals representing the second derivative of, and means for subtracting said second derivative signals from, the filtered pulse signals produced by said low pass filters, where ##EQU5## s=s/ω c , s is the Laplace operator, ω c is the corner frequency, a 1 are polynomial coefficients and k 2 is the coefficient for the second derivative component and D 1 and D 2 are delay factors and A 1 and A 2 are attenuation factors.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1992-10-16	1993-04-17	1993-10-17	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1996-10-16	1997-04-17	1997-10-17	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2000-10-16	2001-04-17	2001-10-17	$7700.00	Window Closed / Lapsed

Compound pulse dimming circuitry for conditioning readback signals

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