Symbol decoding method and means

Claim 1

Symbol decoding means comprising scanning means for scanning a surface upon which coded data has been placed and generating a signal representative of the information scanned; means for generating a plurality of clock signals of different frequencies with the relationship of the frequencies based upon the relationship of a plurality of components of a code symbol to be identified; counting means; and means for applying the various frequencies to the counting means in accordance with the relationship of the different components of a symbol being scanned; whereby the condition of the counting means at the end of a scan of data provides an indication of whether or not the data scanned is the symbol.

Claim 17

A system for decoding a "start of tag" symbol from record media encoded so that said symbol includes in combination a first area of one type at least four and one half units in width, a second area of a second type substantially one unit in width, a third area of said first type substantially one unit in width, and a fourth area of said second type substantially one unit in width, comprising scanning means for scanning a surface upon which coded data has been placed and generating a signal representative of the information scanned; means for generating a plurality of clock signals of different frequencies with the relationship of the frequencies based upon the relationship of various areas of the "start of tag" symbol; first and second counting means; first gating means for generating signals of first and second types from the signal generated by the scanning means; second gating means controlled by the clock signal generating means, the scanning means and the first gating means to provide inputs to said first and second counting means in accordance with whether the signals from said first gating means are of said first type or said second type, the output from said second gating means being caused by said first gating means to be input to said counting means to effect counting in a first direction by signals of a first frequency and to effect counting in an opposite direction by signals of second and third frequencies; and third gating means controlled by said first and second counting means and said first gating means for providing output signals to indicate the presence or absence of a "start of tag" signal in accordance with whether or not the count in said opposite direction is of greater magnitude than the count in said first direction.

Claim 18

A system for decoding a "start of tag" symbol from record media encoded so that said symbol includes in combination a first area of one type at least four and one half units in width, a second area of a second type substantially one unit in width, a third area of said first type substantially one unit in width, and a fourth area of said second type substantially one unit in width, comprising scanning means for scanning a surface upon which coded data has been placed and generating a signal representative of the information scanned; means for generating a plurality of clock signals of different frequencies with the relationship of the frequencies based upon the relationship of various areas of the "start of tag" symbol; first and second counting means; first gating means for generating signals of first and second types from the signal generated by the scanning means; second gating means controlled by the clock signal generating means, the scanning means and the first gating means to provide inputs to said first and second counting means in accordance with whether the signals from said first gating means are of said first type or said second type, the output from said second gating means being caused by said first gating means to be input to said counting means to effect counting in a first direction by signals of a first frequency and to effect counting in an opposite direction by signals of second and third frequencies; and third gating means controlled by said first and second counting means and said first gating means for providing output signals to indicate the presence or absence of a "start of tag" signal in accordance with whether or not the count in said opposite direction is of greater magnitude than the count in said first direction.

Claim 22

A system for decoding an "end of tag" symbol from record media encoded so that said symbol includes in combination a first area of one type substantially one unit in width, a second area of a second type substantially one unit in width, a third area of said first type substantially one unit in width, and a fourth area of said second type at least four and one half units in width, comprising scanning means for scanning a surface upon which coded data has been placed and generating a signal representative of the information scanned; means for generating a plurality of clock signals of different frequencies with the relationship of the frequencies based upon the relationship of various areas of the "end of tag" symbol; first and second counting means; first gating means for generating signals of first and second types from the signal generated by the scanning means; second gating means controlled by the generating means and the first gating means to provide inputs to said first and second counting means in accordance with whether the signals from said first gating means are of said first type or said second type, the output from said second gating means being caused by said first gating means to be input to said counting means to effect counting in a first direction by signals of a first frequency and to effect counting in an opposite direction by signals of second and third frequencies; and third gating means controlled by said first and second counting means and said first gating means for providing output signals to indicate the presence or absence of an "end of tag" signal in accordance with whether or not the count in said opposite direction is of greater magnitude than the count in said first direction.

Claim 23

A system for decoding an "end of tag" symbol from record media encoded so that said symbol includes in combination a first area of one type substantially one unit in width, a second area of a second type substantially one unit in width, a third area of said first type substantially one unit in width, and a fourth area of said second type at least four and one half units in width, comprising scanning means for scanning a surface upon which coded data has been placed and generating a signal representative of the information scanned; means for generating a plurality of clock signals of different frequencies with the relationship of the frequencies based upon the relationship of various areas of the "end of tag" symbol; first and second counting means; first gating means for generating signals of first and second types from the signal generated by the scanning means; second gating means controlled by the generating means and the first gating means to provide inputs to said first and second counting means in accordance with whether the signals from said first gating means are of said first type or said second type, the output from said second gating means being caused by said first gating means to be input to said counting means to effect counting in a first direction by signals of a first frequency and to effect counting in an opposite direction by signals of second and third frequencies; and third gating means controlled by said first and second counting means and said first gating means for providing output signals to indicate the presence or absence of an "end of tag" signal in accordance with whether or not the count in said opposite direction is of greater magnitude than the count in said first direction.

Claim 27

A device for detecting a unique character represented by a combination of contrasting areas, said device comprising signal generating means; means coupled to the signal generating means for deriving three clock signals of different frequencies, the third signal having a frequency equal to that of the sum of the frequencies of the first two signals; sensing means for sensing the extents of said areas in one direction with respect to each other and generating signals representative of said relative extents of said areas; up-down counting means; gating means for passing each of the three clock signals of different frequencies to the up-down counting means for periods of time proportional to the relative extents of the contrasting areas, in predetermined directions and sequence so that the clock signals corresponding to one of the areas causes the up-down counting means to count in one direction, while the clock signals corresponding to at least one of the other areas cause the up-down counting means to count in the other direction, whereby the identify of the character being sensed is determined by whether or not the counter is counted back to its starting position.

Claim 28

A device for detecting a unique character represented by a combination of contrasting areas, said device comprising signal generating means; means coupled to the signal generating means for deriving three clock signals of different frequencies, the third signal having a frequency equal to that of the sum of the frequencies of the first two signals; sensing means for sensing the extents of said areas in one direction with respect to each other and generating signals representative of said relative extents of said areas; up-down counting means; gating means for passing each of the three clock signals of different frequencies to the up-down counting means for periods of time proportional to the relative extents of the contrasting areas, in predetermined directions and sequence so that the clock signals corresponding to one of the areas causes the up-down counting means to count in one direction, while the clock signals corresponding to at least one of the other areas cause the up-down counting means to count in the other direction, whereby the identify of the character being sensed is determined by whether or not the counter is counted back to its starting position.

Claim 29

A method for detecting a unique symbol represented by a combination of contrasting areas, comprising the steps of generating a signal having relatively high and low levels corresponding to predetermined characteristics of the symbol to be sensed; generating a plurality of clock signals; causing said clock signals to be counted in one direction and subsequently in an opposite direction, the ratio of the counts being related to the ratio of high and low signal levels to be derived from sensing a symbol having a predetermined relationship of contrasting areas; and comparing the counts in the two directions to determine whether or not the symbol sensed is the unique symbol.

Claim 30

A method for detecting a unique symbol represented by a combination of contrasting areas, comprising the steps of generating a signal having relatively high and low levels corresponding to predetermined characteristics of the symbol to be sensed; generating a plurality of clock signals; causing said clock signals to be counted in one direction and subsequently in an opposite direction, the ratio of the counts being related to the ratio of high and low signal levels to be derived from sensing a symbol having a predetermined relationship of contrasting areas; and comparing the counts in the two directions to determine whether or not the symbol sensed is the unique symbol.

Claim 32

A method for detecting a unique symbol represented by a combination of contrasting areas, comprising the steps of generating a signal having relatively high and low levels corresponding to predetermined characteristics of the symbol to be sensed; generating a plurality of clock signals of different frequencies; causing at least one of said clock signals to be counted in one direction and at least one of said clock signals to be counted in an opposite direction, the ratio of the counts corresponding to the ratio of high and low signal levels to be derived from sensing a symbol having a predetermined relationship of contrasting areas; and comparing the counts in the two directions to determine whether or not the symbol sensed is the unique character.

Claim 33

A method for detecting a unique symbol represented by a combination of contrasting areas, comprising the steps of generating a signal having relatively high and low levels corresponding to predetermined characteristics of the symbol to be sensed; generating a plurality of clock signals of different frequencies; causing at least one of said clock signals to be counted in one direction and at least one of said clock signals to be counted in an opposite direction, the ratio of the counts corresponding to the ratio of high and low signal levels to be derived from sensing a symbol having a predetermined relationship of contrasting areas; and comparing the counts in the two directions to determine whether or not the symbol sensed is the unique character.

Claim 34

A method for detecting a unique symbol represented by a combination of bars and spaces and for compensating for width variations in the printing of said bars, comprising the steps of establishing a predetermined ratio of given dimensions of bars and spaces for the unique symbol to be detected, said ratio taking into account a variation from standard width resulting from the manner in which bars are printed, to determine weights to be assigned to various bars and spaces of a symbol to be tested; assigning different weights to the various widths measured in accordace with the relationship of bars and spaces in said unique symbol; and making a comparison of the weighted measurements to determine whether or not the symbol sensed is the unique symbol.

Claim 35

A method for detecting a unique symbol represented by a combination of bars and spaces and for compensating for width variations in the printing of said bars, comprising the steps of establishing a predetermined ratio of given dimensions of bars and spaces for the unique symbol to be detected, said ratio taking into account a variation from standard width resulting from the manner in which bars are printed, to determine weights to be assigned to various bars and spaces of a symbol to be tested; assigning different weights to the various widths measured in accordace with the relationship of bars and spaces in said unique symbol; and making a comparison of the weighted measurements to determine whether or not the symbol sensed is the unique symbol.