US RE44,563 E1Granted

Pixel circuit and display apparatus

AssigneeSony Corporation

InventorsJunichi Yamashita, Katsuhide Uchino

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Abstract

Disclosed herein is a pixel circuit that includes a correcting section configured to correct the input voltage sampled in the pixel capacitance in order to cancel out the dependency of the output current on the carrier mobility. In the pixel circuit, the correcting section operates depending on the control signal supplied from the scanning line to extract the output current from the drive transistor and introduce the extracted output current into a capacitance of the light-emitting device and the pixel capacitance, thereby correcting the input voltage. The pixel circuit further includes an additional capacitance added to the capacitance of the light-emitting device. In the pixel circuit, a portion of the output current extracted from the drive transistor flows into the additional capacitance to give a time margin to operation of the correcting section.

Claims42

Dependent claims

A pixel circuit for being positioned at a point of intersection between a row scanning line for supplying a control signal and a column signal line for supplying a video signal, comprising at least:

a sampling transistor;
a pixel capacitance connected to said sampling transistor;
a drive transistor connected to said pixel capacitance;
a light-emitting device connected to said drive transistor;
wherein said sampling transistor is turned on in response to the control signal supplied from said scanning line to sample the video signal supplied from said signal line into said pixel capacitance,
said pixel capacitance applies an input voltage to a gate of said drive transistor depending on the sampled video signal,
said drive transistor supplies an output current depending on said input voltage to said light-emitting device, said output current having dependency on a carrier mobility in a channel region of said drive transistor,
said light-emitting device emits light at a luminance level depending on said video signal in response to the output current supplied from said drive transistor,
said pixel circuit further including
correcting means for correcting the input voltage sampled in said pixel capacitance in order to cancel out the dependency of said output current on the carrier mobility,
wherein said correcting means operates depending on the control signal supplied from said scanning line to extract the output current from said drive transistor and introduce the extracted output current into a capacitance of said light-emitting device and said pixel capacitance for thereby correcting the input voltage, and
an additional capacitance added to the capacitance of said light-emitting device, wherein a portion of the output current extracted from said drive transistor flows into said additional capacitance to give a time margin to operation of said correcting means.

9 more elements

A display apparatus comprising:

a pixel array having a matrix of pixels each positioned at a point of intersection between a row scanning line for supplying a control signal and a column signal line for supplying a video signal;
a signal unit for supplying a video signal to said signal line;
and
a scanner unit for supplying a control signal to said scanning line to successively scan rows of the pixels;
each of said pixels including at least
a sampling transistor,
a pixel capacitance connected to said sampling transistor,
a drive transistor connected to said pixel capacitance,
a light-emitting device connected to said drive transistor,
wherein said sampling transistor is turned on in response to the control signal supplied from said scanning line to sample the video signal supplied from said signal line into said pixel capacitance,
said pixel capacitance applies an input voltage to a gate of said drive transistor depending on the sampled video signal,
said drive transistor supplies an output current depending on said input voltage to said light-emitting device, said output current having dependency on a carrier mobility in a channel region of said drive transistor,
said light-emitting device emits light at a luminance level depending on said video signal in response to the output current supplied from said drive transistor,
each pixel of said pixels further including
correcting means for correcting the input voltage sampled in said pixel capacitance in order to cancel out the dependency of said output current on the carrier mobility,
wherein said correcting means operates depending on the control signal supplied from said scanning line to extract the output current from said drive transistor and introduce the extracted output current into a capacitance of said light-emitting device and said pixel capacitance thereby correcting the input voltage, and
an additional capacitance added to the capacitance of said light-emitting device, wherein a portion of the output current extracted from said drive transistor flows into said additional capacitance to give a time margin to operation of said correcting means.

14 more elements

A pixel circuit for being positioned at a point of intersection between a row scanning line for supplying a control signal and a column signal line for supplying a video signal, comprising at least:

a sampling transistor;
a pixel capacitance;
a drive transistor;
a light-emitting device;
wherein said sampling transistor is turned on in response to the control signal supplied from said row scanning line to sample the video signal supplied from said signal line into said pixel capacitance,
said pixel capacitance applies an input voltage to a gate of said drive transistor depending on the sampled video signal,
said drive transistor supplies an output current depending on said input voltage to said light-emitting device,
said light-emitting device emits light at a luminance level depending on said video signal in response to said output current supplied from said drive transistor,
said pixel circuit corrects the input voltage sampled in said pixel capacitance,
wherein the output current from said drive transistor is extracted into said pixel capacitance, and
an additional capacitance added to said pixel capacitance, a portion of said output current from the drive transistor flowing into said additional capacitance.

8 more elements

A display apparatus comprising:

a pixel array having a matrix of pixels each positioned at a point of intersection between a row scanning line for supplying a control signal and a column signal line for supplying a video signal;
a signal unit for supplying a video signal to said signal line;
and a scanner unit for supplying a control signal to said row scanning line to successively scan rows of the pixels;
each of said pixels including at least
a sampling transistor,
a pixel capacitance,
a drive transistor,
a light-emitting device,
wherein said sampling transistor is turned on in response to the control signal supplied from said row scanning line to sample the video signal supplied from said signal line into said pixel capacitance,
said pixel capacitance applies an input voltage to a gate of said drive transistor depending on the sampled video signal,
said drive transistor supplies an output current depending on said input voltage to said light-emitting device,
said light-emitting device emits light at a luminance level depending on said video signal in response to said output current supplied from said drive transistor,
said pixel circuit corrects the input voltage sampled in said pixel capacitance,
wherein the output current from said drive transistor is extracted into said pixel capacitance, and
an additional capacitance added to said pixel capacitance, a portion of said output current from the drive transistor flowing into said additional capacitance.

12 more elements

A display apparatus comprising:

a pixel array having a matrix of pixels each positioned at a point of intersection between a row scanning line for supplying a control signal and a column signal line for supplying a video signal;
a signal unit for supplying a video signal to said signal line;
and a scanner unit for supplying a control signal to said row scanning line to successively scan rows of the pixels;
each of said pixels including at least
a sampling transistor,
a pixel capacitance,
a drive transistor,
a light-emitting device,
wherein said sampling transistor is turned on in response to the control signal supplied from said row scanning line to sample the video signal supplied from said signal line into said pixel capacitance,
said pixel capacitance applies an input voltage to a gate of said drive transistor depending on the sampled video signal,
said drive transistor supplies an output current depending on said input voltage to said light-emitting device,
said light-emitting device emits light at a luminance level depending on said video signal in response to said output current supplied from said drive transistor,
said pixel circuit corrects the input voltage sampled in said pixel capacitance,
wherein the output current from said drive transistor is extracted into said pixel capacitance, and
an additional capacitance added to said pixel capacitance,
wherein said light-emitting device comprises an anode connected to a source of said drive transistor and a cathode connected to ground, and said additional capacitance has a terminal connected to the anode of said light-emitting device and another terminal connected to a predetermined fixed potential.

13 more elements

Dependencies are inferred from the claim text.