| 摘要 |
A photoelectric reader used in a money-dispensing system to read information that is impressed on a punched-card blank by a bank-customer's embossed credit-card, includes an extra photo-responsive 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 photo-responsive 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.
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