Patent Leaderboard
USPTO Patent Rankings Data through Dec 31, 2025
Home › Credit card which generates a DTMF tone

Credit card which generates a DTMF tone

US Patent 5539819 · Granted Jul 23, 1996

Assignee

No assignee recorded.

Inventors

View full patent text on Google Patents →

More Patents by These Inventors

Exhaust gas purifying apparatus2017
Multi-function telephone apparatus and control method1994