| 摘要 |
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.
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