Matrix display device with light sensing function and time-shared amplifier
US5386543A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 21, 1993 |
| Grant date | Jan 31, 1995 |
| Priority date | — |
| Expiry date | Jul 21, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/042
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A combined matrix display and light sensing device comprising arrays of display elements (12) and light sensing elements (18) connected to a first set of address conductors (14) to which scan signals (15) are applied, a second set of address conductors (16) through which data signals from a drive circuit (30) are supplied to the display elements (12) and to which a detection circuit (40) is connected to detect illumination of sensing elements. The detection circuit comprises charge sensitive amplifier circuits (45) which serve also as buffer amplifiers for data signals from the drive circuit (30). Each circuit (45) comprises an output, a first input connected to a conductor of the second set, a second input, and a switch (48) and capacitor (47) connected in parallel between the output and the first input. A control circuit (19) periodically opens and closes the switch and is arranged to apply to the second input data signals for display elements when the switch is closed and a read potential for reading the condition of sensing elements when the switch is open.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.