Wintest Corporation

Makoto Ookuma

Masatoshi Itoh

Shoji Nara

Shouji Nara

Wataru Yamamoto

Tomoharu Innami

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.

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

The present invention provides a picture element inspecting apparatus and method for an active matrix type display that is constituted by an LCD array device or an EL array device, which is capable of canceling the irregularities in source switches, the noise caused by device driving signals, and the irregularities in devices in the measurement apparatus, and enhancing the accuracy of a picture element inspection. The present invention is based on the finding that irregularities in the direction of the source linescan be canceled by performing, in addition to a charging step and first sensing step that are realized by the charging and discharging of picture elements, a second sensing step in a state where gate lines are not selected, and subtracting correction picture element data thus obtained, and is characterized in that a subtraction operation is performed on effective picture element data obtained by electrically charging picture elements, and correction picture element data obtained in a state where gate linesof picture elementsare not selected, and the quality of the picture elementsis determined based on the subtraction output.

Apparatus and method for inspecting picture elements of an active matrix type display board

An active matrix substrate has a plurality of pixel drive cells, each of which includes a switching element and a capacitor. The capacitor is charged and discharged through the switching element, and a charging current based on a charge stored in the capacitor and a discharge current after discharging the capacitor are sampled. The charging current is sampled at a plurality of points on a time axis in consideration of the variation of the on-resistance of the switching element. Since the load on a path through which an inspection current (charging current or discharge current) flows depends on the position of the pixel drive cells, the wave height value between the charging current and the discharge current is calculated for each pixel drive cell based on the discharge current, and whether or not the pixel drive cell has a defect is determined based on the wave height value.

Method and device for inspection active matrix substrate

It is an object of the present invention to provide an apparatus and method for evaluating an organic EL display, with which there is a simple drive circuit used for testing an organic EL display , evaluation of high reliability can be achieved, and an evaluation of the organic EL display itself is performed prior to the installation of finished product drive circuits to the organic EL display , which makes it possible to suppress the decrease in yield caused by dealing with defective products due to the evaluation results. It was noticed that if the drive (testing) of a pixel is performed during the discharge of the previous pixel after the supply of drive current to that previous pixel , and if the difference between the drive current and discharge current values of the organic EL pixel of the pixel is under a specific level, then it is possible to decide that the pixels constituted by the various organic EL elements are operating normally, and the present invention is characterized in that pixel defects are detected by detecting the difference between drive current and discharge current values for every pixel constituted by an organic EL element

Growing community of inventors

Yokohama, Japan

Makoto Ookuma