qr-code2025-01-20
QR Code History and Principles
Learn the history of QR codes and how they work.
QR codes were invented in 1994 by Denso Wave, a Toyota subsidiary, to track automotive parts.
History
- 1994: Invented in Japan
- 1999: Open license released
- 2000s: Mobile phone adoption
- 2010s: Marketing widespread use
- 2020s: COVID accelerated adoption
How QR Codes Work
QR codes store data in both horizontal and vertical patterns: 1. Finder patterns - Three corner squares for orientation 2. Alignment patterns - Help correct distortion 3. Timing patterns - Define cell coordinates 4. Format info - Error correction level 5. Data area - Actual encoded content
Data Capacity
| Type | Max Characters | |------|---------------| | Numeric | 7,089 | | Alphanumeric | 4,296 | | Binary | 2,953 bytes |
Error Correction Levels
- L: 7% recovery
- M: 15% recovery
- Q: 25% recovery
- H: 30% recovery