Keiichi Tsunokawa

Title: Keiichi Tsunokawa: Inventor of a Prepaid-Card Public Telephone System

Introduction

Keiichi Tsunokawa is an inventor associated with Tokyo, Japan, and Tamura Electric Works, Ltd. His recorded patent concerns a public telephone system that uses prepaid cards to authorize communication.

Latest Patents

Tsunokawa’s listed patent, “Public telephone system using a prepaid card to enable communication,” describes a system connecting public telephone sets to a central apparatus. When a prepaid card is inserted, a telephone reads its card information and sends it to the center over a telephone line. The center checks the information against a database and, if the card is valid, permits speech communication. The system also allows an operator to set a card’s valid period and removes expired card information from the database. Tsunokawa is credited with 1 patent in the provided information.

Career Highlights

The available information associates Tsunokawa with Tamura Electric Works, Ltd. His patent reflects work on prepaid-card validation, centralized recordkeeping, and expiration controls for public telephone services.

Collaborations

Nobuo Suzuki is identified as Tsunokawa’s coworker. The provided information does not specify Suzuki’s role in the patent or the extent of their collaboration.

Conclusion

Keiichi Tsunokawa’s recorded invention addresses how public telephone systems can verify prepaid cards and manage their validity through a central database.