Number | Name | Date | Kind |
---|---|---|---|
3124657 | Peterson | Mar 1964 | |
3134074 | Litke | May 1964 | |
3564416 | Price | Feb 1971 | |
4068093 | Fidi | Jan 1978 | |
4134007 | Koreicho et al. | Jan 1979 |
Number | Date | Country |
---|---|---|
205321 | Dec 1908 | DE2 |
2358626 | Jul 1975 | DEX |
2431937 | Jan 1976 | DEX |
2604652 | Aug 1977 | DEX |
Entry |
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Electronic Design 18, Sep. 1, 1976, "Speech/Hearing Aid Uses Infrared Light Transmitter". |