Bar code reading system and bar code reading apparatus with start margin detection circuitry

摘要: A bar code reading system produces a binary signal from an analog containing signal, and demodulates the into numerals. The includes amplitude increase detector for detecting when of steeply changes, sequence controller controlling output demodulator that When provides detected carries out its task as if has normal white margin, even margin noise. This correctly recognizes start irrespective noise enables lower limit level thereof to be lowered.