Luminance point automatic calibration bill validator

The present invention relates to a technical point bill validator, bill validator luminance point automatic calibration. The disadvantage is that the prior art: an image quality point of instability bill validator; user inconvenient; higher maintenance costs. Point bill validator control circuit of the present invention comprises a digital signal processing chip DSP, a field programmable gate array, the FPGA, the multi-channel enhancement type field effect transistor, a programmable digital potentiometer and analog to digital AD converting chip; DSP digital signal processing chip and field programmable gate array (FPGA) is connected via the EMIF external memory Interface; multi-purpose I connected channel enhancement type field effect transistor and FPGA / O port; a programmable digital potentiometer in series between a multi-channel enhancement type field effect transistor and CIS; AD chip input CIS and the signal output terminal is connected to its output through a common connection with the FPGA I / O port. Advantage of the present invention are: to improve the image quality point the bill validator; lower maintenance costs; and easy to operate.