Patent · US Expired

Learning toy

US5277587A · kind A · utility

4Cited by
12References
11Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 15, 1992
Grant dateJan 11, 1994
Priority date
Expiry dateSep 15, 2012

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG09B3/02
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

A learning device including a holder having a storage area and a display area. Information cards including a problem and a coded solution are selectively introduced into the display area wherein the problem remains visible and the coded answer is viewed through one or more specifically configured openings which combine with the coded answer to provide a deciphered or readable answer.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.