US 2003/0117352 A1 · Semiconductor device and driving method thereof · patentgrep

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Abstract

In a light emitting device, a variation in intensity caused by varying a threshold value of a TFT for supplying a current to a light emitting element for each pixel becomes a burden to an improvement of an image quality of the light emitting device. A voltage equal to the threshold value of a TFT (106) is held in capacitor unit (109). When a video signal is inputted from a source signal line, the voltage held in the capacitor unit is added thereto and a resultant signal is applied to a gate electrode of the TFT (106). Even when a threshold value is varied for each pixel, each threshold value is held in the capacitor unit (109) for each pixel. Thus, the influence of a variation in threshold value can be eliminated. Further, holding of the threshold value is conducted by only the capacitor unit (109) and a charge does not move at writing of a video signal so that a voltage between both electrodes is not changed. Thus, it is not influenced by a variation in capacitance value.

Claims68

Dependent claims

A semiconductor device comprising a pixel provided with a light emitting element, wherein:

the pixel comprises:
a current supply line;
first to third transistors each having a gate electrode and first and second electrodes;
and capacitor means having first and second electrodes;
the first electrode of the capacitor means is electrically connected with the gate electrode of the first transistor and the first electrode of the second transistor;
the second electrode of the second transistor is electrically connected with the first electrode of the first transistor and the first electrode of the third transistor;
during a first period, the second and third transistors are turned on so that a charge is stored in the capacitor means through the first and second transistors;
during a second period, the third transistors is turned off and the second transistor is turned on so that a voltage held by the capacitor means is made equal to a threshold voltage of the first transistor;
during a third period, the second and third transistors are turned off so that a video signal is inputted through the second electrode of the capacitor means;
and
during a fourth period, the second transistors is turned off and the third transistor is turned on so that a current flows between a source and a drain of each of the first and third transistors.

8 more elements

A semiconductor device comprising a pixel provided with a light emitting element, wherein:

the pixel comprises:
a source signal line;
first to third gate signal lines;
a current supply line;
first to fourth transistors each having a gate electrode and first and second electrodes;
capacitor means having first and second electrodes;
and a light emitting element having a first electrode;
the gate electrode of the first transistor is electrically connected with the first gate signal line, the first electrode thereof is electrically connected with the source signal line, and the second electrode thereof is electrically connected with the first electrode of the capacitor means;
the second electrode of the capacitor means is electrically connected with the gate electrode of the second transistor and the first electrode of the third transistor;
the first electrode of the second transistor is electrically connected with the current supply line and the second electrode thereof is electrically connected with the second electrode of the third transistor and the first electrode of the fourth transistor;
the gate electrode of the third transistor is electrically connected with the second gate signal line;
and
the gate electrode of the fourth transistor is electrically connected with the third gate signal line and the second electrode thereof is electrically connected with the first electrode of the light emitting element.

10 more elements

A semiconductor device comprising a pixel provided with a light emitting element, wherein:

the pixel comprises:
a source signal line;
first to fourth gate signal lines;
a current supply line;
first to fifth transistors each having a gate electrode and first and second electrodes;
capacitor means having first and second electrodes;
and a light emitting element having a first electrode;
the gate electrode of the first transistor is electrically connected with the first gate signal line, the first electrode thereof is electrically connected with the source signal line, and the second electrode thereof is electrically connected with the first electrode of the capacitor means;
the second electrode of the capacitor means is electrically connected with the gate electrode of the second transistor and the first electrode of the third transistor;
the first electrode of the second transistor is electrically connected with the current supply line and the second electrode thereof is electrically connected with the second electrode of the third transistor and the first electrode of the fourth transistor;
the gate electrode of the third transistor is electrically connected with the second gate signal line;
the gate electrode of the fourth transistor is electrically connected with the third gate signal line and the second electrode thereof is electrically connected with the first electrode of the light emitting element;
and
the gate electrode of the fifth transistor is electrically connected with the fourth gate signal line and the first electrode thereof is electrically connected with one of the second electrode of the capacitor means and the second electrode of the second transistor.

11 more elements

A semiconductor device comprising a pixel provided with a light emitting element, wherein:

the pixel comprises:
a source signal line;
first to third gate signal lines;
a current supply line;
first to fifth transistors each having a gate electrode and first and second electrodes;
capacitor means having first and second electrodes;
and a light emitting element having a first electrode;
the gate electrode of the first transistor is electrically connected with the first gate signal line, the first electrode thereof is electrically connected with the source signal line, and the second electrode thereof is electrically connected with the first electrode of the capacitor means;
the second electrode of the capacitor means is electrically connected with the gate electrode of the second transistor and the first electrode of the third transistor;
the first electrode of the second transistor is electrically connected with the current supply line and the second electrode thereof is electrically connected with the second electrode of the third transistor and the first electrode of the fourth transistor;
the gate electrode of the third transistor is electrically connected with the second gate signal line;
the gate electrode of the fourth transistor is electrically connected with the first gate signal line and the second electrode thereof is electrically connected with
the first electrode of the light emitting element;
and
the gate electrode of the fifth transistor is electrically connected with the third gate signal line and the first electrode thereof is electrically connected with one of the second electrode of the capacitor means and the second electrode of the second transistor.

12 more elements

A semiconductor device comprising a pixel provided with a light emitting element, wherein:

the pixel comprises:
a source signal line;
first to third gate signal lines;
a current supply line;
first to fifth transistors each having a gate electrode and first and second electrodes;
capacitor means having first and second electrodes;
and a light emitting element having a first electrode;
the gate electrode of the first transistor is electrically connected with the first gate signal line, the first electrode thereof is electrically connected with the source signal line, and the second electrode thereof is electrically connected with the first electrode of the capacitor means;
the second electrode of the capacitor means is electrically connected with the gate electrode of the second transistor, the gate electrode of the fourth transistor, and the first electrode of the third transistor;
the first electrode of the second transistor is electrically connected with the current supply line and the second electrode thereof is electrically connected with the second electrode of the third transistor and the first electrode of the fifth transistor;
the gate electrode of the third transistor is electrically connected with the second gate signal line;
the second electrode of the fourth transistor is electrically connected with the first electrode of the light emitting element;
and
the gate electrode of the fifth transistor is electrically connected with the third gate signal line and the first electrode thereof is electrically connected with one of the second electrode of the second transistor and the second electrode of the third transistor.

11 more elements

A semiconductor device comprising a pixel provided with a light emitting element, wherein:

the pixel comprises:
a source signal line;
first to third gate signal lines;
a current supply line;
first to fifth transistors each having a gate electrode and first and second electrodes;
capacitor means having first and second electrodes;
and a light emitting element having a first electrode;
the gate electrode of the first transistor is electrically connected with the first gate signal line, the first electrode thereof is electrically connected with the source signal line, and the second electrode thereof is electrically connected with the first electrode of the capacitor means;
the second electrode of the capacitor means is electrically connected with the gate electrode of the second transistor, the gate electrode of the fourth transistor, and the first electrode of the third transistor;
the first electrode of the second transistor is electrically connected with the current supply line and the second electrode thereof is electrically connected with the second electrode of the third transistor;
the gate electrode of the third transistor is electrically connected with the second gate signal line;
the first electrode of the fourth transistor is electrically connected with the current supply line and the second electrode thereof is electrically connected with the first electrode of the light emitting element;
and
the gate electrode of the fifth transistor is electrically connected with the third gate signal line and the first electrode thereof is electrically connected with one of the second electrode of the second transistor and the second electrode of the third transistor.

11 more elements

A semiconductor device comprising a pixel provided with a light emitting element, wherein:

the pixel comprises:
a source signal line;
first to fourth gate signal lines;
a current supply line;
first to sixth transistors each having a gate electrode and first and second electrodes;
capacitor means having first and second electrodes;
and a light emitting element having a first electrode;
the gate electrode of the first transistor is electrically connected with the first gate signal line, the first electrode thereof is electrically connected with the source signal line, and the second electrode thereof is electrically connected with the first electrode of the capacitor means;
the second electrode of the capacitor means is electrically connected with the gate electrode of the second transistor, the gate electrode of the fourth transistor, and the first electrode of the third transistor;
the first electrode of the second transistor is electrically connected with the current supply line and the second electrode thereof is electrically connected with the second electrode of the third transistor;
the gate electrode of the third transistor is electrically connected with the second gate signal line;
the first electrode of the fourth transistor is electrically connected with the current supply line and the second electrode thereof is electrically connected with the first electrode of the light emitting element;
the gate electrode of the fifth transistor is electrically connected with the third gate signal line and the first electrode thereof is electrically connected with one of the second electrode of the second transistor and the second electrode of the third transistor;
and
the gate electrode of the sixth transistor is electrically connected with the fourth gate signal line, the first electrode thereof is electrically connected with the current supply line, and the second electrode thereof is electrically connected with the gate electrode of the fourth transistor.

12 more elements

A device comprising a pixel provided with a light emitting element, wherein:

the pixel comprises:
a source signal line;
first to fourth gate signal lines;
a current supply line;
first to sixth transistors each having a gate electrode and first and second electrodes;
capacitor means having first and second electrodes;
and a light emitting element having a first electrode;
the gate electrode of the first transistor is electrically connected with the first gate signal line, the first electrode thereof is electrically connected with the source signal line, and the second electrode thereof is electrically connected with the first electrode of the capacitor means;
the second electrode of the capacitor means is electrically connected with the gate electrode of the second transistor, the gate electrode of the fourth transistor, and the first electrode of the third transistor;
the first electrode of the second transistor is electrically connected with the current supply line and the second electrode thereof is electrically connected with the second electrode of the third transistor;
the gate electrode of the third transistor is electrically connected with the second gate signal line;
the first electrode of the fourth transistor is electrically connected with the current supply line and the second electrode thereof is electrically connected with the first electrode of the light emitting element;
the gate electrode of the fifth transistor is electrically connected with the third gate signal line and the first electrode thereof is electrically connected with one of the second electrode of the second transistor and the second electrode of the third transistor;
and
the gate electrode of the sixth transistor is electrically connected with the fourth gate signal line, the first electrode thereof is electrically connected with the current supply line, and the second electrode thereof is electrically connected with the first electrode of the capacitor means.

12 more elements

A semiconductor device comprising a pixel provided with a light emitting element, wherein:

the pixel comprises:
a source signal line;
first to fourth gate signal lines;
a current supply line;
first to sixth transistors each having a gate electrode and first and second electrodes;
capacitor means having first and second electrodes;
and a light emitting element having a first electrode;
the gate electrode of the first transistor is electrically connected with the first gate signal line, the first electrode thereof is electrically connected with the source signal line, and the second electrode thereof is electrically connected with the first electrode of the capacitor means;
the second electrode of the capacitor means is electrically connected with the gate electrode of the second transistor, the gate electrode of the fourth transistor, and the first electrode of the third transistor;
the first electrode of the second transistor is electrically connected with the current supply line and the second electrode thereof is electrically connected with the second electrode of the third transistor;
the gate electrode of the third transistor is electrically connected with the second gate signal line;
the first electrode of the fourth transistor is electrically connected with the current supply line and the second electrode thereof is electrically connected with the first electrode of the light emitting element;
the gate electrode of the fifth transistor is electrically connected with the third gate signal line and the first electrode thereof is electrically connected with one of the second electrode of the second transistor and the second electrode of the third transistor;
and
the gate electrode of the sixth transistor is electrically connected with the fourth gate signal line and provided between the current supply line and the first electrode of the fourth transistor or between the second electrode of the fourth transistor and the first electrode of the light emitting element.

12 more elements

A semiconductor device comprising a pixel provided with a light emitting element, wherein:

the pixel comprises:
a source signal line;
first to fourth gate signal lines;
a current supply line;
first to sixth transistors each having a gate electrode and first and second electrodes;
capacitor means having first and second electrodes;
and a light emitting element having a first electrode;
the gate electrode of the first transistor is electrically connected with the first gate signal line, the first electrode thereof is electrically connected with the source signal line, and the second electrode thereof is electrically connected with the first electrode of the capacitor means and the first electrode of the fifth transistor;
the second electrode of the capacitor means is electrically connected with the gate electrode of the second transistor, the gate electrode and the first electrode of the fifth transistor, and the first electrode of the third transistor;
the first electrode of the second transistor is electrically connected with the current supply line and the second electrode thereof is electrically connected with the second electrode of the third transistor and the first electrode of the fourth transistor,
the gate electrode of the third transistor is electrically connected with the second gate signal line;
the gate electrode of the fourth transistor is electrically connected with the third gate signal line and the second electrode thereof is electrically connected with the first electrode of the light emitting element;
and
the gate electrode of the sixth transistor is electrically connected with the fourth gate signal line and provided one of between the first electrode of the capacitor means and the first electrode of the fifth transistor, between the first electrode of the third transistor and the second electrode of the fifth transistor, and between the first electrode of the third transistor and the gate electrode of the fifth transistor.

11 more elements

A semiconductor device comprising a pixel provided with a light emitting element, wherein:

the pixel comprises:
a source signal line;
first to third gate signal lines;
a current supply line;
first to sixth transistors each having a gate electrode and first and second electrodes;
capacitor means having first and second electrodes;
and a light emitting element having a first electrode;
the gate electrode of the first transistor is electrically connected with the first gate signal line, the first electrode thereof is electrically connected with the source signal line, and the second electrode thereof is electrically connected with the first electrode of the capacitor means and the first electrode of the fifth transistor;
the second electrode of the capacitor means is electrically connected with the gate electrode of the second transistor, the gate electrode and the first electrode of the fifth transistor, and the first electrode of the third transistor;
the first electrode of the second transistor is electrically connected with the current supply line and the second electrode thereof is electrically connected with the second electrode of the third transistor and the first electrode of the fourth transistor;
the gate electrode of the third transistor is electrically connected with the second gate signal line;
the gate electrode of the fourth transistor is electrically connected with the third gate signal line and the second electrode thereof is electrically connected with the first electrode of the light emitting element;
and
the gate electrode of the sixth transistor is electrically connected with the second gate signal line and provided one of between the first electrode of the capacitor means and the first electrode of the fifth transistor, between the first electrode of the third transistor and the second electrode of the fifth transistor, and between the first electrode of the third transistor and the gate electrode of the fifth transistor

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/279,000Filed 24 Oct 2002
Priority: JP 2001-32639724 Oct 2001
Published: 26 Jun 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification32 codes

G09G 3/3233
Using an active matrix: with pixel circuitry controlling the current through the light-emitting element
G09G 3/3225
Organic, e.g. using organic light-emitting diodes [OLED]: using an active matrix
G09G 3/3266
Organic, e.g. using organic light-emitting diodes [OLED]: details of drivers for scan electrodes
H10D 86/441
Characterised by multiple TFTs: interconnections, e.g. scanning lines

Family

US 7,365,713 B2Related patent
US 2003/0117352 A1This patent

From the US filing history. Foreign family members aren’t listed.

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