Circuit for dealing with a bar code signal and a high speed electric signal

摘要

In a circuit for producing an output signal under selective control of a control signal produced by a processor used in combination, a bar code reader and an optical communication receiver comprise in common a first low pass filter having a first cutoff frequency to produce a first low pass filtered signal. The optical communication receiver comprises a first digitizer connected to the first low pass filter for digitizing the first low pass filtered signal to supply a first digital signal to a serial communication unit. The bar code reader comprises a second low pass filter having a second cutoff frequency and connected to the first low pass filter for filtering the first low pass filtered signal to produce a second low pass filtered signal. A second digitizer is connected to the second low pass filter for digitizing the second low pass filtered signal to supply a second digital signal to an interrupt control unit. Alternatively, the second low pass filter may be connected to an input terminal of the first low pass filter instead of an output terminal of the first low pass filter.