PHOTOELECTRIC READERS
First Claim
1. A photoelectric reader for reading data markings from a carrier element introduced into an illuminated field of said reader, comprising:
- light-emitting means for emitting light to define said illuminated field, said light-emitting means being controllable to vary selectively the intensity of illumination of said field;
a plurality of photo-responsive devices mounted in a mutually spaced relationship to sense the markings of the introduced carrier element by responding to light from individual regions of the carrier element and thereby provide signals in accordance with the data borne by said carrier element;
a further photo-responsive device for deriving a control signal dependent on the level of illumination of the said field;
means mounting the further photo-responsive device to view a portion of said illuminated field so as to respond to light from only a part of said carrier element lying outside any of said regions; and
means responsive to variation of said control signal for regulating the level of illumination of said field to tend to maintain said control signal substantially constant, said regulating means including means for controlling said light-emitting means to vary said illumination intensity in accordance with variation in the control signal supplied by said further photo-responsive device.
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Accused Products
Abstract
A photoelectric reader used in a money-dispensing system to read information that is impressed on a punched-card blank by a bankcustomer'"'"''"'"'s embossed credit-card, includes an extra photoresponsive device that receives reflected light from a part of the blank outside the field of the impressions. Serial energization of light-emitting devices that illuminate the blank is regulated in dependence upon the output of the extra photoresponsive device to tend to maintain this output constant and thereby compensate for temperature and other variations that would otherwise affect the read-out of the information-imprint.
77 Citations
2 Claims
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1. A photoelectric reader for reading data markings from a carrier element introduced into an illuminated field of said reader, comprising:
- light-emitting means for emitting light to define said illuminated field, said light-emitting means being controllable to vary selectively the intensity of illumination of said field;
a plurality of photo-responsive devices mounted in a mutually spaced relationship to sense the markings of the introduced carrier element by responding to light from individual regions of the carrier element and thereby provide signals in accordance with the data borne by said carrier element;
a further photo-responsive device for deriving a control signal dependent on the level of illumination of the said field;
means mounting the further photo-responsive device to view a portion of said illuminated field so as to respond to light from only a part of said carrier element lying outside any of said regions; and
means responsive to variation of said control signal for regulating the level of illumination of said field to tend to maintain said control signal substantially constant, said regulating means including means for controlling said light-emitting means to vary said illumination intensity in accordance with variation in the control signal supplied by said further photo-responsive device.
- light-emitting means for emitting light to define said illuminated field, said light-emitting means being controllable to vary selectively the intensity of illumination of said field;
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2. A photoelectric reader for sensing marking of a carrier element introduced into an illuminated field of said reader, comprising:
- electric light-emitting means for emitting light to define said illuminated field, said light-emitting means comprising a plurality of electric light-emitting devices connected in series with one another;
a plurality of photo-responsive devices mounted in a mutually-spaced relationship to sense the marking of the introduced carrier-element by responding to light reflected from individual regions of the carrier element;
a further photo-responsive device for deriving a signal dependent on the level of illumination of the said field, means mounting the further photo-responsive device to view a portion of said illuminated field so as to respond to light reflected from a part of said carrier element lying outside any of said regions;
means responsive to variation of said signal for regulating the level of illumination of said field to tend to maintain said signal substantially constant, said regulating means including means for varying energization of the said serially connected light-emitting devices in dependence upon variation of the signal supplied by said further photo-responsive device;
means mounting said plurality of photo-responsive devices in line with said further photo-responsive device; and
means mounting the light-emitting devices to lie in a line substantially parallel to the line of photo-responsive devices.
- electric light-emitting means for emitting light to define said illuminated field, said light-emitting means comprising a plurality of electric light-emitting devices connected in series with one another;
Specification