Title:
TABLET INTEGRATED WITH ACTIVE MATRIX TYPE LIQUID CRYSTAL DISPLAY AND ITS DRIVING METHOD
Document Type and Number:
Japanese Patent JP2626595
Kind Code:
B2
Abstract:
PURPOSE: To realize an input device integrated with an active matrix type liquid crystal display with a simple constitution without increasing the weight and the voltage of the device.
CONSTITUTION: The application period of a signal for a position detection is provided in this device in addition to a period for voltage writing to pixel electrodes and a signal for determining coordinates is applied to an counter electrode in this period and then a position determination is performed by detecting this signal with a capacitance coupling. At this time, operations of gate and source drivers are stopped in the application period of the signal for the position detection to avoid a malfunction due to noise. Moreover, scanning lines and signal lines are set in a state in which they are electrically insulated by making outputs of drivers driving scanning lines and signal lines high impedances in this period so as to suppress the variation of the signal for the position detection due to the capacitance changes of liquid crystal.
Inventors:
Naoyasu Ikeda
Application Number:
JP30706994A
Publication Date:
July 02, 1997
Filing Date:
November 17, 1994
Export Citation:
Assignee:
NEC
International Classes:
G02F1/133; G06F3/033; G06F3/041; G06F3/044; G06K11/06; G09G3/36; (IPC1-7): G02F1/133; G02F1/133; G06F3/033; G06K11/16; G09G3/36
Domestic Patent References:
| JP7253852A | ||||
| JP7160419A | ||||
| JP6175771A |
Attorney, Agent or Firm:
Asato Kato