Bar code reader

Claim 2

A bar code reader for reading a code consisting of visual bars of at least two different lengths arranged in a side-by-side pattern with the bottoms of said bars being approximately arranged along a line, said code reader comprising: a. first and second photosensors; b. means supporting said photosensors in a line approximately parallel to the bars of said bar code; c. means for moving an image of said bar code past said sensors, said motion being such as to move all of said bars past said first sensor and the longer portion of said longer bars past said second sensor, whereby said photosensors generate signals corresponding to the passage of said bars past said sensors; d. differentiating means coupled to said photosensors for differentiating the signals generated by said sensors; e. a first logic circuit coupled to said differentiating means for generating a signal corresponding to the differentiated signal from said first sensor; f. a second logic circuit coupled to said differentiating means for generating a signal corresponding to the coincidence of said differentiated signals; and g. a third logic circuit means coupled to said differentiating means for generating a signal corresponding to the presence of the differentiated signal of said first photosensor and the absence of the differentiated signal of said second photosensor.

Claim 3

A bar code reader for reading a code consisting of visual bars of at least two different lengths arranged in a side-by-side pattern on an envelope with the bottoms of said bars being approximately arranged along a line, said code reader comprising: a. first and second photosensors; b. means supporting said photosensors in a line approximately parallel to the bars of said bar code; c. means for moving an image of said bar code past said sensors, said motion being such as to move all of said bars on said envelope past said first sensor and the longer portion of said longer bars past said second sensor, whereby said photosensors generate signals corresponding to the passage of said bars past said sensors; d. differentiating means coupled to said photosensors for differentiating the signals generated by said sensors; e. a first logic circuit coupled to said differentiating means for generating a signal corresponding to the differentiated signal from said first sensor; f. a second logic circuit coupled to said differentiating means for generating a signal corresponding to the coincidence of said differentiated signals; and g. a third logic circuit for generating a signal indicating the cessation of differentiated signals of said first photosensor.

Claim 4

A bar code reader for reading a code consisting of visual bars of at least two different lengths arranged in a side-by-side pattern on an envelope with the bottoms of said bars being approximately arranged along a line, said code reader comprising: a. first and second photosensors; b. means supporting said photosensors in a line approximately parallel to the bars of said bar code; c. means for moving an image of said bar code past said sensors, said motion being such as to move all of said bars on said envelope past said first sensor and the longer portion of said longer bars past said second sensor, whereby said photosensors generate signals corresponding to the passage of said bars past said sensors; d. differentiating means coupled to said photosensors for differentiating the signals generated by said sensors; e. a first logic circuit coupled to said differentiating means for generating a signal corresponding to the differentiated signal from said first sensor; f. a second logic circuit coupled to said differentiating means for generating a signal corresponding to the coincidence of said differentiated signals; and g. a third logic circuit for generating a signal indicating the cessation of differentiated signals of said first photosensor.

Claim 5

A bar code reader for reading a code consisting of visual bars of two different lengths arranged in a side-by-side pattern on an envelope with the bottoms of said bars being approximately arranged along a line, said visual bars being comprised of full bars being on the order of 0.100 inch in height and half bars being on the order of 0.050 inch, the bar width and spacing between bars being on the order of 0.010 inch, said code reader comprising: a. optical means including first and second photosensors positioned in a plane; b. means for moving said envelope past said optical means to form an image of said code on said sensors, thE bar width in said image being on the order of 0.005 inch, said motion being such as to move the images of all of said bars past said first sensor and the images of the longer portion of the longer bars past said second sensor, whereby said photosensors generate signals corresponding to the passage of said bars past said sensors; c. first and second differentiating means coupled to said photosensors for differentiating the signals generated by said sensors; d. first and second operational amplifiers coupled respectively to said first and second differentiating means for amplifying the differentiated signals; e. a first logic circuit including a delay circuit coupled to said first operational amplifier for generating a delayed clock signal corresponding to the differentiated signal from said first sensor; f. a second logic circuit coupled to said first and second operational amplifiers for generating a full-bar signal corresponding to the coincidence of the first and second differentiated signals; g. a third logic circuit coupled to said first and second operational amplifiers for generating a half-bar signal corresponding to the presence of the first differentiated signal and the absence of the second differentiated signal; and h. a fourth logic circuit coupled to said first operational amplifier for generating a signal at a predetermined time after the cessation of said first differentiated signal.

Claim 6

A bar code reader for reading a code consisting of visual bars of two different lengths arranged in a side-by-side pattern on an envelope with the bottoms of said bars being approximately arranged along a line, said visual bars being comprised of full bars being on the order of 0.100 inch in height and half bars being on the order of 0.050 inch, the bar width and spacing between bars being on the order of 0.010 inch, said code reader comprising: a. optical means including first and second photosensors positioned in a plane; b. means for moving said envelope past said optical means to form an image of said code on said sensors, thE bar width in said image being on the order of 0.005 inch, said motion being such as to move the images of all of said bars past said first sensor and the images of the longer portion of the longer bars past said second sensor, whereby said photosensors generate signals corresponding to the passage of said bars past said sensors; c. first and second differentiating means coupled to said photosensors for differentiating the signals generated by said sensors; d. first and second operational amplifiers coupled respectively to said first and second differentiating means for amplifying the differentiated signals; e. a first logic circuit including a delay circuit coupled to said first operational amplifier for generating a delayed clock signal corresponding to the differentiated signal from said first sensor; f. a second logic circuit coupled to said first and second operational amplifiers for generating a full-bar signal corresponding to the coincidence of the first and second differentiated signals; g. a third logic circuit coupled to said first and second operational amplifiers for generating a half-bar signal corresponding to the presence of the first differentiated signal and the absence of the second differentiated signal; and h. a fourth logic circuit coupled to said first operational amplifier for generating a signal at a predetermined time after the cessation of said first differentiated signal.