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US 7,248,255 B2Granted
Active drive type light emitting display device and drive control method thereof
AssigneeTohoku Pioneer Corporation
InventorTakayoshi Yoshida
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AssigneeTohoku Pioneer Corporation
InventorTakayoshi Yoshida
Estimating the term…
In a light emitting display device which is actively driven by TFTs, light emitting display pixels are driven efficiently. In a light emitting display panel 10, a large number of light emitting display pixels 10a are arranged in a matrix pattern and measuring pixels 10b are arranged forming a line along one dataline. A constant current is supplied from a constant current source 11 to the measuring pixels 10b, and the forward voltage VF of the EL element in the measuring pixel 10b is obtained by a voltage detecting terminal 12. The value of the drive voltage supplied to the light emitting display pixels 10a is controlled based on the forward voltage VF. Thus, a drive TFT (Tr2) constructing the light emitting display pixel 10a can drive an EL element E1 in the state where a drop voltage (VD) of the degree by which a constant current characteristic can be ensured is ensured, and a power loss generated in the drive TFT can be effectively restrained.
An active drive type light emitting display device in which a large number of light emitting display pixels each of which at least comprises a light emitting element and a drive TFT that allows a drive current to flow to the light emitting element are arranged, wherein the active drive type light emitting display device is constructed in such a way that a plurality of measuring pixels each of which at least comprising a measuring element and a drive TFT that allows a drive current to flow to the measuring element are further arranged in the light emitting display device so that a forward voltage of the measuring element constructing the measuring pixel can be picked up from a power supply line of the measuring pixel.
A drive control method for an active drive type light emitting display device in which a large number of light emitting display pixels each of which at least comprises a light emitting element and a drive TFT that allows a drive current to flow to the light emitting element are arranged and further in which a plurality of measuring pixels each of which at least comprises a measuring element and a drive TFT that allows a drive current to flow to the measuring element are arranged, wherein the drive control method for the active drive type light emitting display device executes the step of driving the measuring element constructing the measuring pixel, the step of obtaining a forward voltage of the measuring element from a power supply line of the measuring pixel, and the step of controlling a drive voltage applied to the light emitting display pixel based on the forward voltage.
Dependencies are inferred from the claim text.