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

A picture element inspecting apparatus for an active matrix type display, for determining the quality of picture elements of a device to be inspected that is either an active matrix type display in which the picture elements are arranged at the respective intersecting portions of a plurality of column select lines and a plurality of row select lines into a matrix shape and the picture elements can be driven by a horizontal driving circuit and a vertical driving circuit, or a display board thereof, said picture element inspecting apparatus comprising:

• a subtracting circuit for performing a subtraction operation on effective picture element data from said picture elements driven by said driving circuits and correction picture element data obtained by driving the picture elements in a state where either said row select lines or said column select lines of the picture elements are not selected;
• and
• a defect determining circuit for determining the quality of the picture elements based on the subtraction output from this subtracting circuit.

A picture element inspecting apparatus for an active matrix type display, for determining the quality of picture elements of a device to be inspected that is either an active matrix type display in which the picture elements are arranged at the respective intersecting portions of a plurality of column select lines and a plurality of row select lines into a matrix shape and the picture elements can be driven by a horizontal driving circuit and a vertical driving circuit, or a display board thereof,

• wherein a subtraction operation is performed on effective picture element data obtained as a discharge waveform from said picture elements by electrically charging said picture elements of said device to be inspected using said horizontal driving circuit and said vertical driving circuit, and correction picture element data obtained as a signal waveform resulting from a reason other than the electric discharge from said picture elements by once again driving both said row select lines and said column select lines of the picture elements, without carrying out said charging operation after acquiring the effective picture element data, and the quality of said picture elements is determined based on the subtraction output thus obtained.

A picture element inspecting apparatus for an active matrix type display, for determining the quality of picture elements of a device to be inspected that is either an active matrix type display in which the picture elements are arranged at the respective intersecting portions of a plurality of column select lines and a plurality of row select lines into a matrix shape and the picture elements can be driven by a horizontal driving circuit and a vertical driving circuit, or a display board thereof, said picture element inspecting apparatus comprising:

• a subtracting circuit for performing a subtraction operation on effective picture element data from said picture elements driven by said driving circuits, and correction picture element data obtained by once again driving both said row select lines and said column select lines of the picture elements after acquiring said effective picture element data;
• and
• a defect determining circuit for determining the quality of said picture elements based on the subtraction output from this subtracting circuit.

A picture element inspecting method for an active matrix type display, for determining the quality of picture elements of to a device to be inspected that is either an active matrix type display in which the picture elements are arranged at the respective intersecting portions of a plurality of column select lines and a plurality of row select lines into a matrix shape and the picture elements can be driven by a horizontal driving circuit and a vertical driving circuit, or a display board thereof, said picture element inspecting method comprising the steps of:

• performing a subtraction operation on effective picture element data obtained as a discharge waveform from said picture elements by electrically charging said picture elements of said device to be inspected using said horizontal driving circuit and said vertical driving circuit, and correction picture element data obtained from said picture elements in a state where either said row select lines or said column select lines of said picture elements are not selected after acquiring the effective picture element data;
• and
• determining the quality of said picture elements based on the subtraction output thus obtained.