US 2006/0125512 A1Published application

Method and apparatus for inspecting array substrate

AssigneeAgilent Technologies, Inc.

InventorsNobutaka Itagaki, Hideyuki Norimatsu

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Abstract

A method for inspecting an active-matrix-display-panel array substrate includes: a first step of applying a voltage V1 to the data terminal of a transistor while the transistor conducts, bringing the transistor into a non-conductive state, applying a voltage V1+ΔV to the data terminal, bringing the transistor into a conductive state, and measuring charge ΔQ; a second step of applying a voltage V0 to the data terminal when the transistor does not conduct and the data terminal voltage is V3, and measuring a voltage Q1 flowing through the transistor when the transistor conducts; a third step of applying a voltage V0′ to the data terminal when the transistor does not conduct and the data terminal voltage is V4, and measuring charge Q2 flowing when the transistor conducts; and a fourth step of determining a capacitance of the capacitor based on ΔV, ΔQ, V0, V0′, V3, V4, Q1, and Q2.

Claims15

Dependent claims

A method for inspecting an array substrate in an active-matrix display panel, the array substrate having a switching transistor having a data terminal, a source terminal, and a gate terminal, a pixel drive circuit connected to the source terminal of the transistor, and a pixel-voltage storing capacitor connected to the pixel drive circuit and the source terminal, the method comprising:

a first step of applying a voltage V1 to the data terminal while the transistor is in a conductive state, bringing the transistor into a non-conductive state, applying a different voltage V1+ΔV to the data terminal while the transistor is in the non-conductive state, bringing the transistor into the conductive state, and measuring an amount of charge ΔQ flowing through the transistor;
a second step of applying a voltage V0 to the data terminal when the transistor is in the non-conductive state, the voltage applied to the data terminal is a voltage V3 different from the voltage V0, and a potential of the capacitor is VC;
and of measuring an amount of voltage Q1 flowing through the transistor when the transistor is brought into the conductive state;
a third step of applying a voltage V0′ to the data terminal when the transistor is in the non-conductive state with the voltage applied to the data terminal being a voltage V4 different from the voltage V3, and the potential of the capacitor being a potential VC;
and then measuring an amount of charge Q2 flowing through the transistor when the transistor is brought into the conductive state;
and
a fourth step of determining a capacitance CS of the capacitor based on values of ΔV, ΔQ, V0, V0′, V3, V4, Q1, and Q2.

4 more elements

An apparatus for inspecting an array substrate in an active-matrix display panel, the array substrate having a switching transistor having a data terminal, a source terminal, and a gate terminal, a pixel drive circuit connected to the source terminal of the transistor, and a pixel-voltage storing capacitor connected to the pixel drive circuit and the source terminal, the apparatus comprising:

a voltage source;
a charge measuring circuit;
a processing unit;
and
storing means;
wherein the processing unit controls:
a first operation of causing the voltage source to apply a voltage V1 to the data terminal while the transistor is in a conductive state, to bring the transistor into a non-conductive state, to apply a different voltage V1+ΔV to the data terminal while the transistor is in the non-conductive state, and to bring the transistor into the conductive state;
causing the charge measuring circuit to measure an amount of charge ΔQ flowing through the transistor;
and causing the storing means to store the amount of charge ΔQ;
a second operation of causing the voltage source to apply a voltage V0 to the data terminal when the transistor is in the non-conductive state with the voltage applied to the data terminal being a voltage V3 different from the voltage V0, and a potential of the capacitor being VC;
causing the charge measuring circuit to measure an amount of charge Q1 flowing through the transistor, when the transistor is brought into the conductive state;
and causing the storing means to store the amount of charge Q1;
and
a third operation of causing the voltage supply to apply a voltage V0′ to the data terminal when the transistor is in the non-conductive state with the voltage applied to the data terminal being a voltage V4 different from the voltage V3, and the potential of the capacitor being VC;
causing the charge measuring circuit to measure an amount of charge Q2 flowing through the transistor, when the transistor is brought into the conductive state;
and causing the storing means to store the amount of charge Q2;
and
the processing unit performs a fourth operation of determining a capacitance of the capacitor based on values of ΔV, V0, V0′, V3, and V4 and values of ΔQ, Q1, and Q2 stored by the storing means.

15 more elements

Dependencies are inferred from the claim text.