Inspection method and inspection device for display device and active matrix substrate used for display device

Abstract

An inspection device for a display device includes: an inspection circuit which judges a defect of each of pixels based on current which flows through an inspection interconnect connected with interconnects of the display device; and an inspection driver circuit which drives by supplying a necessary signal to the display device. The inspection circuit includes: a correction circuit which generates a first correction current which substantially cancels a first current which flows through the inspection interconnect when all the pixels are set to an off-state based on the first current; a detection circuit which detects a measured value for each pixel obtained by correcting a measured current which flows through the inspection interconnect by the first correction current each time the pixels are sequentially set to an on-state; and a defect judgment circuit which judges a defect of each of the pixels based on the measured value.

1 - 14 . (canceled)  
   
   
       15 . An inspection method for an active matrix substrate, comprising: 
 providing an active matrix substrate which includes a plurality of pixels, each of the pixels being connected with one of a plurality of signal lines, one of a plurality of scan lines, and one of a plurality of voltage supply lines, each of the pixels including a pixel select transistor connected with one of the signal lines and one of the scan lines, an operating transistor, and a storage capacitor for holding a gate potential of the operating transistor, a gate of the operating transistor being connected with the storage capacitor and the pixel select transistor, one of a source and a drain of the operating transistor being connected with one of the voltage supply lines, and the other of the source and the drain of the operating transistor being connected with an inspection interconnect;    generating a first correction current which substantially cancels a first current which flows through the inspection interconnect when the operating transistor of each of the pixels is set to an off-state;    inspecting the operating transistor by sequentially causing the operating transistor of each of the pixels to be turned on; and    judging a defect of the operating transistor of each of the pixels based on a measured value obtained by correcting a measured current which flows through the inspection interconnect by the first correction current each time the operating transistor of each of the pixels is sequentially turned on.    
   
   
       16 . The inspection method for an active matrix substrate as defined in  claim 15 , 
 wherein, in the inspection step, the operating transistor of an inspection target pixel, which is one of the pixels, is set to an on-state, and the operating transistor of the inspection target pixel is set to the off-state before setting the operating transistor of another pixel to b subsequently inspected amount the pixels to the on-state, and    wherein, in the defect judgment step, a defect of the operating transistor of each of the pixels is judged based on a difference between the measured value in the on- state and the measured value in the off-state.    
   
   
       17 . The inspection method for an active matrix substrate as defined in  claim 15 , 
 wherein, in the inspection step, the operating transistor of one of the pixels is set to the on-state, and the operating transistor of another pixel to be subsequently inspected among the pixels is set to the on-state while maintaining the on-state of the operating transistor of the one of the pixels.    
   
   
       18 . The inspection method for an active matrix substrate as defined in  claim 17 , 
 wherein the pixels are formed along a plurality of lines in the display device,    wherein the inspection step further includes:    measuring a second current which flows through the inspection interconnect each time the inspection step is completed for the pixels for one line of the display device; and    generating a second correction current, which substantially cancels the second current, instead of the first correction current, and    wherein the second correction current is updated each time the inspection step is completed for the pixels for one line of the display device.    
   
   
       19 . The inspection method for an active matrix substrate as defined in  claim 17 , 
 wherein the inspection step further includes:    measuring a second current which flows through the inspection interconnect each time the inspection step is completed for one of the pixels; and    generating a second correction current, which substantially cancels the second current, instead of the first correction current, and    wherein the second correction current is updated each time the inspection step is completed for the one of the pixels.    
   
   
       20 . An inspection device for inspecting an active matrix substrate which includes a plurality of pixels, each of the pixels being connected with one of a plurality of signal lines, one of a plurality of scan lines, and one of a plurality of voltage supply lines, each of the pixels including a pixel select transistor connected with one of the signal lines and one of the scan lines, an operating transistor, and a storage capacitor for holding a gate potential of the operating transistor, a gate of the operating transistor being connected with the storage capacitor and the pixel select transistor, one of a source and a drain of the operating transistor being connected with one of the voltage supply lines, and the other of the source and the drain of the operating transistor being connected with an inspection interconnect, the inspection device comprising: 
 an inspection circuit which judges a defect of each of the pixels based on current which flows through the inspection interconnect; and    an inspection driver circuit which drives the active matrix substrate by supplying a signal necessary for inspection to the active matrix substrate;    wherein the inspection circuit includes:    a correction circuit which generates a first correction current which substantially cancels a first current which flows through the inspection interconnect based on the first current when the operating transistor of each of the pixels is set to an off-state;    a detection circuit which detects a measured value obtained by correcting a measured current which flows through the inspection interconnect by the first correction current each time the operating transistor of each of the pixels is sequentially set to an on-state; and    a defect judgment circuit which judges a defect of the operating transistor of each of the pixels based on the measured value.