| 摘要 |
<p>PURPOSE:To read out an optical mark put on paper by storing the output values of an optical sensor as the darkest and lightest data, setting up the intermediate values between both the data as a reference value and comparing an output value obtained at the movement of the optical sensor along the paper with the reference value. CONSTITUTION:To obtain the output values of the optical sensor 12 at the set status and unset status of optical mark paper, a CPU19 outputs a prescribed comparing signal to a D/A converter 28 and a comparator 27 compares the output value of the optical sensor 12 with the output of converter 28 and inputs the compared result to the CPU19. The CPU19 stores the output values from the optical sensor 12 at the paper unset status and set status in the storage parts 22, 23 of a RAM21 respectively as the darkest and lightest data. The CPU19 sets up a reference value for optical mark reading on the intermediate point of the darkest and lightest data and stores it in a storage part 24 of the RAM21. When the paper is moved, the CPU19 outputs a signal corresponding to the reference value to the D/A converter 28 and compares the signal with the output value from the optical sensor 12 by the comparator 27 to read out the optical mark on the basis of the compared result.</p> |
