Signal transition detection circuit

Claim 2

In combination: delay means responsive to an alternating input signal for delaying said signal; means including a peak amplitude detection means and energy divider means also responsive to said alternating input signal for producing a signal whose peak value is equal to a fraction of the peak value in one sense of said alternating signal; and comparator means responsive to the signals produced by the delay means and the second-named means for producing a signal at a first level when the amplitude of the delay means signal exceeds that of the other signal and for producing a signal at a second, different level when the inverse is true.

Claim 3

The combination as set forth in claim 1 wherein the transitions of said alternating signals occur at integral multiples of some value, X, and wherein said delay means comprises means for delaying said signal substantially one half X.

Claim 4

The combination as set forth in claim 1 wherein said peak detection means is a resettable peak detection means, and further including means responsive to the transitions in said alternating signal from the sense detected by said peak detection means to the opposite sense for resetting said peak detection means.

Claim 5

The combination as set forth in claim 3, further including means for resetting said peak detection means to a value intermediate the opposite extremes of said alternating signal.

Claim 6

The combination as set forth in claim 1, further including means responsive to said first level signal from said comparator means for causing the delay means signal to exceed the other signal by a greater amount than if this means were absent.

Claim 7

The combination as set forth in claim 1 wherein said means including a peak amplifier detection means and energy divider means comprises a peak amplitude detection means responsive to said alternating input signal for producing a signal whose peak value corresponds to the peak value in one sense of said alternating signal and further comprises an amplitude divider means responsive to the signal from said peak detection means for producing a signal having a value which is a fraction of the signal produced by said peak detection means.

Claim 8

In combination: means producing an alternating signal the peaks of which may be of nonuniform amplitude; means responsive to said signal for producing a signal whose peak value corresponds to a peak in one sense of said alternating signal; means also responsive to said alternating signal for producing a signal whose peak value corresponds to the next succeeding peak in the opposite sense from that represented by said last-named means; averaging means responsive to the signals from said last two named means for producing a signal having a value which is the average of those two signals; delay means responsive to said alternating signal for delaying it; and comparatOr means responsive to said delayed signal and said averaged signal for producing a signal at a first level when the amplitude of the delay means signal exceeds that of the other signal and for producing a signal at a second different level when the inverse is true.

Claim 9

In combination: means producing an alternating signal the peaks of which may be of nonuniform amplitude; means responsive to said signal for producing a signal whose peak value corresponds to a peak in one sense of said alternating signal; means also responsive to said alternating signal for producing a signal whose peak value corresponds to the next succeeding peak in the opposite sense from that represented by said last-named means; averaging means responsive to the signals from said last two named means for producing a signal having a value which is the average of those two signals; delay means responsive to said alternating signal for delaying it; and comparatOr means responsive to said delayed signal and said averaged signal for producing a signal at a first level when the amplitude of the delay means signal exceeds that of the other signal and for producing a signal at a second different level when the inverse is true.

Claim 10

In combination: means producing an alternating signal the peaks of which may be of nonuniform amplitude; amplitude divider means responsive to said signal for producing a signal having a value which is a fraction of the alternating signal; means responsive to said divider means signal for producing a signal whose peak value is equal to a peak in one sense produced by said divider means; means also responsive to said divider means signal for producing a signal whose peak value is equal to the next succeeding peak from said voltage divider means in the opposite sense from that represented by said last-named means; summing means responsive to the signal from said last two named means for producing a signal which is the sum of those two signals; delay means responsive to said alternating signal for delaying it; and comparator means responsive to said delayed signal and said summed signal for producing a signal at a first level when the amplitude of the delay means signal exceeds that of the other signal and for producing a signal at a second different level when the inverse is true.

Claim 11

In combination: means producing an alternating signal the peaks of which may be of nonuniform amplitude; amplitude divider means responsive to said signal for producing a signal having a value which is a fraction of the alternating signal; means responsive to said divider means signal for producing a signal whose peak value is equal to a peak in one sense produced by said divider means; means also responsive to said divider means signal for producing a signal whose peak value is equal to the next succeeding peak from said voltage divider means in the opposite sense from that represented by said last-named means; summing means responsive to the signal from said last two named means for producing a signal which is the sum of those two signals; delay means responsive to said alternating signal for delaying it; and comparator means responsive to said delayed signal and said summed signal for producing a signal at a first level when the amplitude of the delay means signal exceeds that of the other signal and for producing a signal at a second different level when the inverse is true.

Claim 12

An arrangement for detecting the times at which an asymmetrical alternating signal changes from a value on one side of a variable threshold level to a value on the other side of this threshold level, where the threshold level is dependent on the varying peak amplitude of the alternating signal comprising, in combination: means for producing an attenuated, peak detected version of said alternating signal on said one side of said variable threshold level; means for delaying the alternating signal relatively to the attenuated peak detected signal; and means receptive of the relatively delayed alternating signal and the attenuated peak detected signal for producing an output signal each time the amplitude level of one of the signals crosses that of the other.

Claim 13

An arrangement for detecting the times at which an asymmetrical alternating signal changes from a value on one side of a variable threshold level to a value on the other side of this threshold level, where the threshold level is dependent on the varying peak amplitude of the alternating signal comprising, in combination: means for producing an attenuated, peak detected version of said alternating signal on said one side of said variable threshold level; means for delaying the alternating signal relatively to the attenuated peak detected signal; and means receptive of the relatively delayed alternating signal and the attenuated peak detected signal for producing an output signal each time the amplitude level of one of the signals crosses that of the other.

Claim 14

The combination as set forth in claim 9 further including means for resetting the attenuated peak detected signal producing means to a reference value at least when said alternating signal goes to said other side of said threshold level.

Claim 15

The combination as set forth in claim 9 wherein said means producing an attenuated peak detected version of said alternating signal comprises means for peak detecting the alternating signal and means for attenuating the peak detected alternating signal to a given percentage of its value.

Claim 16

The combination as set forth in claim 9 wherein said means producing an attenuated peak detected version of said alternating signal comprises means for attenuating the alternating signal to a given percentage of its value and means for peak detecting the attenuated signal.

Claim 17

Apparatus for reading binary encoded information in the form of alternating regions of indicia exhibiting two different reflectivities representative of binary information comprising, in combination: optical scanning means producing an alternating signal the amplitude of which corresponds to the reflectivity of the information being scanned; means producing an attenuated peak detected version of said alternating signal; means for delaying the alternating signal relative to the attenuated signal; and means receptive of the delayed signal and the alternating signal for producing an output signal indicative of which of said two received signals is the greater amplitude.

Claim 18

Apparatus for reading binary encoded information in the form of alternating regions of indicia exhibiting two different reflectivities representative of binary information comprising, in combination: optical scanning means producing an alternating signal the amplitude of which corresponds to the reflectivity of the information being scanned; means producing an attenuated peak detected version of said alternating signal; means for delaying the alternating signal relative to the attenuated signal; and means receptive of the delayed signal and the alternating signal for producing an output signal indicative of which of said two received signals is the greater amplitude.

Claim 19

The combination as set forth in claim 13 wherein said binary encoded information is in the form of regions of two basic colors exhibiting substantially two different reflectivities, the dimension of each region along the scan path being an integral multiple of a unit dimension and wherein said optical scanning means iNcludes means for scanning at a fixed rate along said scan path.

Claim 20

The combination as set forth in claim 14 wherein said delaying means includes means for delaying said alternating signal a time equal to a fraction of the time required to scan said unit dimension.

Claim 21

The combination as set forth in claim 15 wherein said means receptive of said delayed and attenuated signals includes means for producing a signal at a first level corresponding to a scan of one of said two basic colors when the amplitude of said delayed signal exceeds said attenuated signal and producing a signal at a second level when the reverse conditions are true, the leading edge of each of said levels being delayed from the time of scan across a boundary between said two colors by the amount of delay in said delay means.

Claim 22

The combination as set forth in claim 16 further including means responsive to a change in the level in one sense of the two level signal for resetting to a reference level the means producing the attenuated, peak detected version of said alternating signal.

Claim 23

Apparatus for reading binary indicia in the form of regions of alternating colors exhibiting two substantially different reflectivities comprising, in combination: optical scanning means producing a signal the amplitude of which corresponds at any point in time to the reflectivity of the region being scanned each region along the scan path being greater than a given width; means producing a signal which is the average of the signal produced by said scanning means while scanning two adjacent regions exhibiting substantially different reflectivity; delay means for delaying the optical scanning signal relative to the averaged signal by an amount which is a fraction of the time required by said scanner to scan said given width; and means receptive of the delayed signal and the averaged signal for producing an output signal the value of which is indicative of which of the two input signals has the greater amplitude, whereby when the averaged signal has the greater amplitude the value of the output signal corresponds to a scan over a region of one reflectivity while when the delayed signal has the greater amplitude, a scan over a region of the other reflectivity is indicated, the leading edge of each value of the signal being delayed from the time of actual scan by the amount of delay in said delay means.

Claim 24

Apparatus for reading binary indicia in the form of regions of alternating colors exhibiting two substantially different reflectivities comprising, in combination: optical scanning means producing a signal the amplitude of which corresponds at any point in time to the reflectivity of the region being scanned each region along the scan path being greater than a given width; means producing a signal which is the average of the signal produced by said scanning means while scanning two adjacent regions exhibiting substantially different reflectivity; delay means for delaying the optical scanning signal relative to the averaged signal by an amount which is a fraction of the time required by said scanner to scan said given width; and means receptive of the delayed signal and the averaged signal for producing an output signal the value of which is indicative of which of the two input signals has the greater amplitude, whereby when the averaged signal has the greater amplitude the value of the output signal corresponds to a scan over a region of one reflectivity while when the delayed signal has the greater amplitude, a scan over a region of the other reflectivity is indicated, the leading edge of each value of the signal being delayed from the time of actual scan by the amount of delay in said delay means.

Claim 25

The combination as set forth in claim 18 wherein said averaging means comprises attenuating means producing a signal which is substantially one half of the optical scanning means signal, first peak detecting means receptive of said attenuated signal for producing a signal corresponding to peaks of the attenuated signal corresponding to a scan of a region of one reflectivity, a second signal peak detecting means for producing a signal corresponding to a scan of a region of the other reflectivity and a summing means which produces a signal which is the sum of the signals from said two peak detecting means.

Claim 26

The combination as set forth in claim 18 wherein said averaging means comprises a first peak detection means responsive to said signal from said optical scanning means for producing a signal which is receptive of the peak amplitude of said optical scanning means signal while scanning a region of one reflectivity, the second peak detection means for producing a signal receptive of the peak signal in the opposite sense while scanning regions of said other reflectivity, summing means receptive of the signals from both peak detection means for producing a signal which is a sum of those two signals and attenuation means producing a signal which is substantially one half of said summed signal.

Claim 27

The combination as set forth in claim 19 further including means for resetting one of the peak detection means to within a given magnitude of the signal level in the other peak detection means in response to said output signal changing from a value corresponding to a scan over a region of the Reflectivity the optical scanning signal value of which is stored in said one of the peak detection means to the other value.