Barcode ball Development History
The earliest products that were bar coded were Wrigley's chewing gum. Barcode technology was first produced in the twenties of the 20th century, and was born in Westinghouse's laboratory. An inventor named John Kermode, who was weird, wanted to automate the sorting of postal documents. At that time, every idea about the application of electronic technology was very novel.
His idea is to mark the envelope with a bar code. The information in the bar code is the address of the recipient, just like today's zip code. For this purpose, Comende invented the earliest barcode identification, and the design scheme was very simple (Note: this method is called the module comparison method), that is, a "bar" indicates the number "1", and two "bars" indicate the number "2" ", and so on. He then invented barcode reading equipment consisting of basic components: a scanner (which emits light and receives reflected light); a method for determining the reflection signal strips and nulls, namely edge-positioning coils; and the use of measurement results. Method, the decoder.
Comund's scanner uses the newly invented photovoltaic cell to collect reflected light. "Air" reflects strong signals, and "bars" reflect weak signals. Unlike today's high-speed electronic component applications, Comend uses magnetic coils to measure "bars" and "blanks." It's like a child connecting a wire to a battery and wrapping it around a nail. Colmend uses a coil with a core to attract a switch when it receives the “empty” signal, and releases the switch and closes the circuit when it receives the “bar” signal. Therefore, the earliest barcode readers were noisy. The switch is controlled by a series of relays. "On" and "Off" are determined by the number of "bars" printed on the envelope. In this way, the bar code symbol directly sorts the letter.
Shortly afterwards, Comund's co-author Douglas Young made some improvements based on the Corumd Code.
The Corumd code contains a very low amount of information, and it is difficult to code more than ten different codes. The Yang code uses fewer bars, but utilizes empty dimensional changes between bars, just as today's UPC bar code symbols use four different bar spaces. The new bar code symbol can encode one hundred different regions in the same size of space, and the Comend code can only encode ten different regions.