Patent ID: 7081908

Claim:
An apparatus for testing a pixel electrode structure in which a plurality of pixel electrodes are arranged in a matrix of n rows and m columns, each of n and m being a natural number more than 1, and each of said plurality of pixel electrodes being activated, comprising: a testing unit which has at least one potential sensor using an FET function in which a specific one of said plurality of pixel electrodes is used as a gate of an FET; wherein said at least one potential sensor is arranged opposite to said specific pixel electrode while keeping a predetermined distance from said specific pixel electrode, said potential sensor including two semiconductor regions of a first conductive type provided separately in a semiconductor region of a second conductive type, said PET function is realized by said potential sensor and said specific pixel electrode, said potential sensor is activated in response to a sensor activation signal to output a voltage detection result associated with an activated pixel electrode; a drive section which relatively drives said tasting unit to said specific pixel electrode with respect to said pixel electrode structure while keeping said predetermined distance, in response to a testing unit drive signal; and a control unit which outputs said testing unit drive signal to said drive section, sequentially activates said specific pixel electrode and pixel electrodes adjacent to said specific pixel electrode when said testing unit is driven to said specific pixel electrode, outputs said sensor activation signal to said testing unit, and detects a disconnection of said specific pixel electrode and a short-circuit between said specific pixel electrode and each of said adjacent pixel electrodes based on said voltage detection result.