Portable information terminal
US6728812B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 14, 1999 |
| Grant date | Apr 27, 2004 |
| Priority date | — |
| Expiry date | Dec 14, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F1/1626
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A portable information terminal has at least a programming ROM, a work RAM, a data storage memory, an input key, a liquid crystal display panel, a liquid crystal driving control circuit, a built-in battery, and a central processing unit which is operated by using the programming ROM and the work RAM and displays data in the data storage memory on the liquid crystal display panel. Further, the portable information terminal comprises a switching control circuit which outputs a switching signal in accordance with an input signal from an external computer apparatus connected to the terminal, a control signal switching circuit which switches an address bus, a data bus and memory control signal lines which are connected to the central processing unit to an address bus, a data bus and memory control signal lines which are connected to the external computer apparatus in accordance with the switching signal in order to access the data storage memory from the external computer apparatus, and a serial signal switching circuit which switches a PCMCIA bus control signal to a serial signal in accordance with an input signal from a serial interface device which is connected between the portable i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.