Communication link
US4423319A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 13, 1981 |
| Grant date | Dec 27, 1983 |
| Priority date | — |
| Expiry date | Jan 13, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/26
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A communication link for transferring information from a data terminal with connected light pen (3), which includes a light diode (4) and a phototransistor (5) or corresponding means, to a greater computer unit. According to the invention, the communication link (1) includes an information transferring device, which according to a first embodiment comprises a phototransistor (11). The light pen (3) is arranged so as by means of its light diode (4) to emit light corresponding to information stored in the data terminal (10), which information is converted via the phototransistor (11) to electric signals and transferred to the greater computer unit. According to a second embodiment, the information transferring device also includes a light diode (16), which is arranged so as to emit light pulses corresponding to instructions to the data terminal (10) arriving from a greater computer unit. The phototransistor (5) of the light pen (3) is arranged so as to convert said last mentioned pulses to electric signals and to transfer the same to the data terminal (10).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.