Deep field optical label reader including means for certifying the validity of a label reading

Claim 2

Recognition means for converting a visual pattern into electrical signals comprising: a source of a coherent beam of light; means for scanning said beam of light along a predetermined path, said pattern to be recognized being in said predetermined path; transducer means for converting light signals exposed thereto into output electrical signals; means for exposing said predetermined path to said transducer; said visual pattern comprising a generally plane surface having light absorbent and light non-absorbent areas, said pattern being exposed in said predetermined path while said beam scans along said predetermined path for at least a first and second scan and wherein said transducer means comprises: phototransducer means for converting light signals exposed thereto during said first scan into a first train of electrical pulses, said first train being correlated to the position of said light absorbent and light non-absorbent areas in said predetermined path during said first scan, and for converting light signals exposed thereto during said second scan into a second train of electrical pulses, said second train being correlated to the position of said light absorbent and light non-absorbent areas in said predetermined path during said second scan; means comparing said first and second trains for generating said output electrical signals; said comparing means comprising: a first register for storing said first pulse train; a second register for storing said second pulse train; and, means responsive to said first stored pulse train and said second stored pulse train for generating said output electrical signals.

Claim 3

A recognition system for converting a pattern into electrical output signals comprising: a source of illuminating energy; means for scanning said energy along said pattern as said pattern and said source move relative to one another; transducer means for converting energy reflected from said pattern into electrical signals; said pattern including energy absorbent areas and energy non-absorbent areas which are successively illuminated by said energy during at least two complete scans of said pattern; said transducer converting said energy to a first train of electrical pulses during the first of said scans and to a second train of electrical pulses during the second of said scans, said pulse trains having pulses of different amplitudes representative of said absorbent and non-absorbent areas; means for counting the pulses in said first and second pulse trains for determining that each of said pulse trains contains an equal number of pulses to thereby determine said pulse trains to be valid; means for temporarily storing said first and second pulse train until said counting means determines them to be valid; first storage register for storing said first pulse train when determined to be valid; second storage register for storing said second pulse train when determined to be valid; and means for comparing said first and second valid pulse trains and generating said output electrical signals.

Claim 4

A recognition system for converting a pattern into electrical output signals comprising: a source of illuminating energy; means for scanning said energy along said pattern as said pattern and said source move relative to one another; transducer means for converting energy reflected from said pattern into electrical signals; said pattern including energy absorbent areas and energy non-absorbent areas which are successively illuminated by said energy during at least two complete scans of said pattern; said transducer converting said energy to a first train of electrical pulses during the first of said scans and to a second train of electrical pulses during the second of said scans, said pulse trains having pulses of different amplitudes representative of said absorbent and non-absorbent areas; means for counting the pulses in said first and second pulse trains for determining that each of said pulse trains contains an equal number of pulses to thereby determine said pulse trains to be valid; means for temporarily storing said first and second pulse train until said counting means determines them to be valid; first storage register for storing said first pulse train when determined to be valid; second storage register for storing said second pulse train when determined to be valid; and means for comparing said first and second valid pulse trains and generating said output electrical signals.

Claim 5

Means as recited in claim 2 with additionally means responsive to said output Electrical signals for clearing said first and second storage registers.

Claim 6

Means as recited in claim 2 wherein said energy is coherent light and wherein said energy absorbent and energy non-absorbent areas have a dimension intercepted by said predetermined path within a predetermined range whereby the resultant range of said pulse train pulse widths is within a predetermined range, all pulses having a pulse width outside said predetermined range being invalid pulses, said first named means additionally comprising a pulse sampler responsive to invalid pulses for generating an invalid pulse signal.

Claim 7

Means as recited in claim 4 wherein said counting means includes means responsive to said invalid pulse signal for clearing itself.

Claim 8

Means as recited in claim 5 wherein said temporary storing means includes means responsive to said invalid pulse signal for clearing itself.

Claim 9

In means for reading a label having alternate light absorbent and light non-absorbent areas, said reading means including a scanning light source for repetitively scanning a beam of light along a predetermined path at a preselected scanning rate, said label being in said path whereby said alternate areas are successively illuminated by said scanning beam, the time duration an area is illuminated being dependent at least in part upon the distance from said label to a transducer which observes said label as illuminated by said scanning beam and which is responsive to illumination of said label for generating electrical signals having a characteristic correlated to the time duration an area is illuminated, an improvement comprising; logic means for processing said electrical signals in accordance with said characteristic; means responsive to the distance of said label from said transducer for varying the response of said logic means to said characteristic; said means for varying the response of said logic means comprising photocell means for generating signals indicative of the distance of said label from said transducer, said logic means including means responsive to said characteristic for sampling said electrical signals, the response of said sampling means to said characteristic being determined by said photocell means signals.

Claim 10

In means for reading a label having alternate light absorbent and light non-absorbent areas, said reading means including a scanning light source for repetitively scanning a beam of light along a predetermined path at a preselected scanning rate, said label being in said path whereby said alternate areas are successively illuminated by said scanning beam, the time duration an area is illuminated being dependent at least in part upon the distance from said label to a transducer which observes said label as illuminated by said scanning beam and which is responsive to illumination of said label for generating electrical signals having a characteristic correlated to the time duration an area is illuminated, an improvement comprising; logic means for processing said electrical signals in accordance with said characteristic; means responsive to the distance of said label from said transducer for varying the response of said logic means to said characteristic; said means for varying the response of said logic means comprising photocell means for generating signals indicative of the distance of said label from said transducer, said logic means including means responsive to said characteristic for sampling said electrical signals, the response of said sampling means to said characteristic being determined by said photocell means signals.

Claim 13

Label reading means as recited in claim 8 wherein said means for varying the response of said logic means comprises means for varying said predetermined delay time according to the distance of said label from said transducer.

Claim 14

Label reading means as recited in claim 9 wherein said label has a predetermined number of Said light absorbent and light non-absorbent areas whereby a pulse train resulting from a single scan of said label will include a predetermined number of pulses and including means for counting the number of pulses in said pulse train resulting from a single scan of said label, the number attained by said counter being indicative of, at least in part, whether a valid label has been scanned.

Claim 15

Label reading means as recited in claim 8 with additionally pulse width sampling means for generating an invalid pulse signal when the width of the pulses comprising said pulse train lie without a range encompassing said first and second pulse widths.

Claim 16

Label reading means as recited in claim 11 wherein said logic means includes means responsive to said invalid pulse signal for returning said logic means to an initial state.

Claim 17

Label reading means as recited in claim 11 wherein said pulse sampling means comprises: a counter including counter clearing means responsive to a predetermined portion of the pulses comprising said pulse train for clearing said counter; and, a free running oscillator for strobing said counter, the count accumulated by said counter being a measure of pulse train pulse width, said counter generating said invalid pulse signal whenever it has accumulated a count corresponding to a pulse width lying without said range of pulse widths encompassing said first and second pulse widths.

Claim 18

Label reading means as recited in claim 13 wherein said logic means includes: gate means opened when said counter is cleared for passing said invalid pulse signal if it is at that time being generated by said counter; and, means responsive to said invalid pulse signal if passed through said gate means for returning said logic means to an initial state.

Claim 19

In means for reading a label having alternate light absorbent and light non-absorbent areas, said reading means including a scanning light source for repetitively scanning a beam of light along a predetermined path at a preselected scanning rate, said label being in said path whereby said alternate areas are successively illuminated by said scanning beam, the time duration an area is illuminated being dependent at least in part upon the distance from said label to a transducer which observes said label as illuminated by said scanning beam and which is responsive to illumination of said label for generating electrical signals having a characteristic correlated to the time duration an area is illuminated, an improvement comprising; logic means for processing said electrical signals in accordance with said characteristic; means responsive to the distance of said label from said transducer for varying the response of said logic means to said characteristic; means wherein said electrical signals comprise binary level signals, a first level signal being generated in response to the illumination of a light absorbent area and a second level signal being generated in response to the illumination of a light non-absorbent area, the electrical signals thus comprising a pulse train pulse width modulated in accordance with the time duration an area is illuminated; and means wherein at one of the groups comprising said light absorbent areas or said light non-absorbent areas is comprised of a first subgroup of areas having a first predetermined dimension in said path and a second subgroup of areas having a second predetermined dimension in said path, and with additionally pulse width sampling means for generating an invalid pulse width signal when the width of the pulses comprising said pulse train lie without a first predetermined range of pulse widths.

Claim 20

In means for reading a label having alternate light absorbent and light non-absorbent areas, said reading means including a scanning light source for repetitively scanning a beam of light along a predetermined path at a preselected scanning rate, said label being in said path whereby said alternate areas are successively illuminated by said scanning beam, the time duration an area is illuminated being dependent at least in part upon the distance from said label to a transducer which observes said label as illuminated by said scanning beam and which is responsive to illumination of said label for generating electrical signals having a characteristic correlated to the time duration an area is illuminated, an improvement comprising; logic means for processing said electrical signals in accordance with said characteristic; means responsive to the distance of said label from said transducer for varying the response of said logic means to said characteristic; means wherein said electrical signals comprise binary level signals, a first level signal being generated in response to the illumination of a light absorbent area and a second level signal being generated in response to the illumination of a light non-absorbent area, the electrical signals thus comprising a pulse train pulse width modulated in accordance with the time duration an area is illuminated; and means wherein at one of the groups comprising said light absorbent areas or said light non-absorbent areas is comprised of a first subgroup of areas having a first predetermined dimension in said path and a second subgroup of areas having a second predetermined dimension in said path, and with additionally pulse width sampling means for generating an invalid pulse width signal when the width of the pulses comprising said pulse train lie without a first predetermined range of pulse widths.

Claim 21

Label reading means as recited in claim 15 wherein said pulse width sampling means comprises: a free running oscillator; a counter strobed by said free running oscillator and accumulating a count proportional to time, said counter including means for resetting itself in response to the leading edge of pulses in said pulse train, Said counter generating said invalid pulse width signal whenever it has accumulated a count corresponding to a pulse width without said first predetermined range.

Claim 22

Label reading means as recited in claim 15 wherein said means for varying the response of said logic means comprises means for varying the range of pulse widths without which said invalid pulse width signal is generated.

Claim 23

Label reading means as recited in claim 17 wherein said pulse width sampling means comprises: counting means accumulating a count proportional to time and including means for clearing itself in response to the leading edge of pulses in said pulse train, said counting means generating said invalid pulse width signal whenever it has accumulated a count corresponding to a pulse width without said first predetermined range, said means for varying the response of said logic means comprising means for varying said counting means according to the distance of said label from said transducer whereby the count to be accumulated by said counting means to generate said invalid pulse width signal is varied.

Claim 24

In a label reader generating a binary pulse width modulated pulse train of a predetermined number of pulses encoding the informational content of a label, logic means for certifying the validity of a label reading comprising: pulse width sampling means for generating an invalid pulse signal when the width of a pulse in said pulse train is without a predetermined range; first counter means cleared by said invalid pulse signal and strobed by said pulse train so as to accumulate a count related to the number of pulses in said pulse train for generating a valid label signal when said first counter means accumulates a count corresponding to said predetermined number of pulses; a first storage register means for sampling said pulse train and storing said sampled pulse train; a second storage register first gating means responsive to a first said valid label signal corresponding to a first generating of said binary pulse width modulated pulse train for transferring the contents of said first storage register into said second storage register; a third storage register; second gating means responsive to a second said valid label signal corresponding to a second generating of said binary pulse width modulated pulse train for transferring the contents of said first storage register into said third storage register; and, means comparing the contents of said second and third storage registers to generate an output electrical signal which certifies the validity of the label reading.

Claim 25

In a label reader generating a binary pulse width modulated pulse train of a predetermined number of pulses encoding the informational content of a label, logic means for certifying the validity of a label reading comprising: pulse width sampling means for generating an invalid pulse signal when the width of a pulse in said pulse train is without a predetermined range; first counter means cleared by said invalid pulse signal and strobed by said pulse train so as to accumulate a count related to the number of pulses in said pulse train for generating a valid label signal when said first counter means accumulates a count corresponding to said predetermined number of pulses; a first storage register means for sampling said pulse train and storing said sampled pulse train; a second storage register first gating means responsive to a first said valid label signal corresponding to a first generating of said binary pulse width modulated pulse train for transferring the contents of said first storage register into said second storage register; a third storage register; second gating means responsive to a second said valid label signal corresponding to a second generating of said binary pulse width modulated pulse train for transferring the contents of said first storage register into said third storage register; and, means comparing the contents of said second and third storage registers to generate an output electrical signal which certifies the validity of the label reading.

Claim 26

Logic means as recited in claim 19 with additionally means responsive to said output electrical signal for generating a clearing signal, said second and third storage registers being responsive to said clearing signal for returning to an initial state.

Claim 27

Logic means as recited in claim 19 wherein the width of pulses in said pulse train varies in accordance with a determinable variable and with additionally: means for sensing said determinable variable to generate error signals; and, means responsive to said error signals for varying said predetermined range in accordance with said determinable variable.

Claim 28

Logic means as recited in claim 19 wherein said first storage register means comprises means responsive to the width of pulses in said pulse width modulated pulse train for converting said pulse width modulated pulse train into a binary digital pulse train comprising said sampled pulse train, said first, second and third registers comprising binary digital storage registers and wherein the width of pulses in said pulse width modulated pulse train varies in accordance with a determinable variable, said logic means additionally comprising: means responsive to said determinable variable for generating error signals; and, means responsive to said error signals for varying the response of said converting means to the width of pulses in said pulse width modulated pulse train.

Claim 29

Logic means as recited in claim 22 with additionally means responsive to said error signals for varying said predetermined range in accordance with said determinable variable.

Claim 30

Logic means as recited in claim 23 wherein the distance of said label being read from said label reader comprises said determinable variable, said means for generating error signals comprising photocell means detecting said distance for generating electrical error signals comprising said error signals.

Claim 31

Recognition means for converting a visual pattern into electrical signals comprising: a source of a coherent beam of light; means for scanning said beam of light along a predetermined path, said pattern to be recognized being in said predetermined path; transducer means for converting light signals exposed thereto into output electrical signals; means for exposing said predetermined path to said transducer; said visual pattern comprising a surface having alternate light absorbent and light non-absorbent areas disposed in said predetermined path whereby said areas are consecutively illuminated by said scanning beam of light and wherein said transducer means comprises: phototransducer means for converting light signals exposed thereto into a train of electrical pulses, said exposing means exposing said predetermined path to said phototransducer means, the time duration a scanned area is illuminated determining the pulse width of a resultant pulse of said pulse train; logic means responsive to the widths of the pulses in said pulse train for generating said output electrical signals; and means responsive to the distance of said pattern from said phototransducer for varying the response of said logic means to said pulse widths.

Claim 32

Recognition means for converting a visual pattern into electrical signals comprising: a source of a coherent beam of light; means for scanning said beam of light along a predetermined path, said pattern to be recognized being in said predetermined path; transducer means for converting light signals exposed thereto into output electrical signals; means for exposing said predetermined path to said transducer; said visual pattern comprising a surface having alternate light absorbent and light non-absorbent areas disposed in said predetermined path whereby said areas are consecutively illuminated by said scanning beam of light and wherein said transducer means comprises: phototransducer means for converting light signals exposed thereto into a train of electrical pulses, said exposing means exposing said predetermined path to said phototransducer means, the time duration a scanned area is illuminated determining the pulse width of a resultant pulse of said pulse train; logic means responsive to the widths of the pulses in said pulse train for generating said output electrical signals; and means responsive to the distance of said pattern from said phototransducer for varying the response of said logic means to said pulse widths.

Claim 35

The system of claim 20 wherein there is relative motion between said system and said pattern, said axis and the direction of said scanning nominally occuring along a line substantially parallel to the direction of said motion.

Claim 36

The system of claim 20 wherein there is relative motion between said system and said pattern, said axis and the direction of said scanning nominally occuring along a line substantially perpendicular to the direction of said motion.

Claim 37

The system of claim 20 wherein saiD pattern is rectangular and said areas are parallel to two sides of said rectangle.

Claim 38

The system of claim 20 wherein said pattern is semi-circular and said areas are concentric about the center of the diameter of said pattern.

Claim 39

The system of claim 20 wherein said pattern is circular and said areas are concentrically arranged on said pattern.