Record cards and photoelectric scanning arrangements for use in record card controlled machines

摘要

755,665. Photo-electric record sensing. INTERNATIONAL BUSINESS MACHINES CORPORATION. March 31, 1954 [April 1, 1953], No. 9423/54. Class 40 (3). In photo-electrical statistical apparatus the record card is made green in a region of approxi. mately 5200 Š, and the data is recorded in the index point positions in red. This is stated to improve photo-electric contrast. A cadmium sulphide resistance photo-cell is particularly suitable. Designations of data index point 'positions and lines surrounding the data recording marks may be white.