Test thin film transistors are provided outside of the pixel region of an LCD panel that includes an array of pixel thin film transistors and intersecting arrays of spaced apart data lines and gate lines connected to the array of pixel thin film transistors. A respective test thin film transistor is connected to a respective one of the data lines or gate lines. At least subgroups of the test thin film transistors are commonly connected to provide common energization of subgroups of data lines or test lines for gross testing of the LCD panels. Rubber pads are therefore not required to energize each individual data line or gate line for gross testing. Moreover, after testing is completed, test thin film transistors need not be cut or otherwise mechanically disconnected. Test thin film transistors may be organized for tape automated bonding (TAB) LCD panels or for chip on glass (COG) LCD panels. Associated methods are also provided.
A checking machine for being used in a fabricating process of a display module and checking a position of a tape automated bonding (TAB) region is provided. The checking machine includes a main holder having an inclined panel positioned at an inclination .beta. relative to the horizontal, wherein the range of the inclination .beta. is 0.degree.<.beta..ltoreq.90.degree., a test plate having a first hollow portion for suiting a size of the display module and a circuit plate disposed around the first hollow portion for suiting the position of the tape automated bonding region, and a fixing device for fixing the test plate to the inclined panel, thereby the tape automated bonding region is electrically connected with the circuit plate.
A testing apparatus for flat-panel display is disclosed. The flat-panel display at least comprises a plurality of electrode lines and a plurality of driving circuits. The driving circuits are used to drive the electrode lines. The driving circuits and the testing apparatus are disposed on the opposite sides of the flat-panel display. The testing apparatus comprises a plurality of switching components and at least one shorting bar. The shorting bar electrically couples to the electrode lines through the switching components. When the switching components are thin film transistor, the switching components further comprise at least one switching line. The switching line electrically couples to the gates of the thin film transistors. The electrode lines are divided into several groups to electrically couple to the shorting bar and the switching line, for example.
An active matrix display device has an inspection circuit for inspecting the image quality. The inspection circuit includes a plurality of input terminals for inputting a test signal and a plurality of test transistors connected respectively to the input terminals. Input test signals which are to be sent to sub pixel sections from the individual input terminals are controlled by the associated test transistors to display a desired test screen. The test transistors are preferably amorphous silicon TFTs.
A test pad array and dummy lead array for measuring anisotropic conductive film bond contact resistance on a liquid crystal display panel. The test pad and dummy lead arrays are provided on a surface of the liquid crystal display panel. The test pad array is electrically connected to a group of terminal pads disposed on the surface of the panel, which are electrically connected to an electronic device with anisotropic conductive film bonds. The test pad array allows the contact resistance of one or more of the anisotropic conductive film bonds to be measured on the panel. The dummy lead array is provided for electrically connecting a second electronic device to the panel. The dummy lead array is electrically connected to the test pad array such that a contact resistance of at least one anisotropic conductive film bond associated with the second electronic device can be measured on the panel using portions of the test pad array electrically connected to the dummy lead array.
