Asynchronous to synchronous converter
US4079240A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 5, 1976 |
| Grant date | Mar 14, 1978 |
| Priority date | — |
| Expiry date | Feb 5, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/0166
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An asynchronous to synchronous converter is disclosed which produces clock pulses in synchronism with data bits of a non-return-to-zero (NRZ) code having a variable data rate. The converter is established adapted for use in optical reading of the Universal Products Code (UPC) code symbol which is of bar code format. The converter comprises a high level bit clock system for clocking the dark bar bits and a low level bit clock system for clocking the light bar bits. A high level measurement circuit times the single bit dark bar pulses and sets the timing for the low level bit clock system and a low level measurement circuit times the single bit low level pulses and sets the timing for the high level bit clock system. The converter receives asynchronous serial data and produces a clock pulse for each bit of the data pulse so that the serial data may be decoded.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.