EL display apparatus

Patent metadata

Field	Value
Publication number	US-10198992-B2
Application number	US-201715858692-A
Country	US
Kind code	B2
Filing date	Dec 29, 2017
Priority date	Sep 7, 2001
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

An electroluminescent (EL) display apparatus and method of controlling are provided. A display screen includes gate signal lines and source signal lines. A pixel corresponds to each intersection of the gate and source signal lines. Each pixel includes: an EL device including an anode and cathode terminals; a driving transistor to flow a current to the EL device; a first switch transistor provided on a current path through which the current flows from a power line through the driving transistor to the EL device; a second switch transistor to supply, to the driving transistor, an image signal from one of the source signal lines; and a third switch transistor provided between the anode terminal of the EL device and a voltage line. The voltage line is configured to supply a reverse bias voltage for reverse biasing the anode terminal of the EL device.

First claim

What is claimed is:

1. An electroluminescent (EL) display apparatus, comprising:
a display screen including:
a plurality of first gate signal lines;
a plurality of second gate signal lines;
a plurality of source signal lines; and
a plurality of pixels arranged in a matrix, each pixel corresponding to an intersection of the plurality of first gate signal lines and the plurality of source signal lines; and
a gate driver circuit including a first gate driver circuit connected to the plurality of first gate signal lines and a second gate driver circuit connected to the plurality of second gate signal lines,
wherein each pixel includes:
an EL device including an anode terminal and a cathode terminal;
a driving transistor to flow a current to the EL device;
a first switch transistor provided on a current path through which the current flows from a power line through the driving transistor to the EL device, the first switch transistor being controlled by the first gate driver circuit;
a second switch transistor to supply, to the driving transistor, an image signal supplied from one of the plurality of source signal lines; and
a third switch transistor provided between the anode terminal of the EL device and a voltage line, the third switch transistor being controlled by the second gate driver circuit, the voltage line being configured to supply a reverse bias voltage for reverse biasing the anode terminal of the EL device,
the first switch transistor is configured to be controlled in an OFF state by the first gate driver circuit, when the second gate driver circuit controls the third switch transistor in a state for reverse biasing the anode terminal of the EL device, and
the first gate driver circuit is configured to turn the first switch transistor from an ON state to the OFF state, and, after a lapse of time, the second gate driver circuit is configured to turn the third switch transistor from an OFF state to an ON state for reverse biasing the anode terminal of the EL device.

2. The EL display apparatus according to claim 1 , further comprising:
a source driver circuit connected to the plurality of source signal lines,
wherein the source driver circuit is configured to supply a signal voltage to a gate of the driving transistor to flow a current which is N times as large as a predetermined value to the EL device to achieve a gray scale display indicated by the image signal, and
N is greater than one.

3. The EL display apparatus according to claim 1 , further comprising:
a precharge circuit or a discharge circuit which forcibly charges or discharges the one of the plurality of source signal lines.

4. The EL display apparatus according to claim 1 ,
wherein the second gate driver circuit is configured to turn the third switch transistor from the ON state for reverse biasing the anode terminal of the EL device to the OFF state, and, after a second lapse of time, the first gate driver circuit is configured to turn the first switch transistor from the OFF state to the ON state.

5. The EL display apparatus according to claim 1 ,
wherein the first gate driver circuit is configured to select a plurality of the first gate signal lines simultaneously.

6. The EL display apparatus according to claim 1 ,
wherein the first gate signal lines are divided into a plurality of blocks,
a plurality of first gate signal lines in one block are connected as one control line, and
the first gate driver circuit is configured to select the plurality of first gate signal lines as a block simultaneously.

7. An electronic device, comprising:
the EL display apparatus according to claim 1 .

8. A method of controlling an electroluminescent (EL) display apparatus,
the EL display apparatus including:
a display screen including:
first gate signal lines, the first gate signal lines being divided into a plurality of blocks, a plurality of the first gate signal lines in one block being connected as one control line;
second gate signal lines;
a plurality of source signal lines; and
a plurality of pixels arranged in a matrix, each pixel corresponding to an intersection of the first gate signal lines and the plurality of source signal lines; and

a gate driver circuit including a first gate driver circuit connected to the first gate signal lines and a second gate driver circuit connected to the second gate signal lines,

wherein each pixel includes:
an EL device including an anode terminal and a cathode terminal;
a driving transistor to flow a current to the EL device;
a first switch transistor provided on a current path through which the current flows from a power line through the driving transistor to the EL device;
a second switch transistor to supply, to the driving transistor, an image signal supplied from one of the plurality of source signal lines; and
a third switch transistor provided between the anode terminal of the EL device and a voltage line, the voltage line configured to supply a reverse bias voltage for reverse biasing the anode terminal of the EL device;

the method comprising:
controlling the first switch transistor via the first gate driver circuit;
selecting the plurality of first gate signal lines via the first gate driver circuit as a block simultaneously; and
controlling, via the second gate driver circuit, the third switch transistor to be in an ON state for reverse biasing the anode terminal of the EL device.

9. The method according to claim 8 , further comprising:
controlling the first switch transistor to be in an OFF state via the first gate driver circuit, when the second gate driver circuit controls the third switch transistor to be in the ON state for reverse biasing the anode terminal of the EL device.

10. An electroluminescent (EL) display apparatus, comprising:
a display screen including:
a plurality of first gate signal lines;
a plurality of second gate signal lines;
a plurality of source signal lines; and
a plurality of pixels arranged in a matrix, each pixel corresponding to an intersection of the plurality of first gate signal lines and the plurality of source signal lines; and

a gate driver circuit including a first gate driver circuit connected to the plurality of first gate signal lines and a second gate driver circuit connected to the plurality of second gate signal lines,
wherein each pixel includes:
an EL device including an anode terminal and a cathode terminal;
a driving transistor to flow a current to the EL device;
a first switch transistor provided on a current path through which the current flows from a power line through the driving transistor to the EL device, the first switch transistor being controlled by the first gate driver circuit;
a second switch transistor to supply, to the driving transistor, an image signal supplied from one of the plurality of source signal lines; and
a third switch transistor provided between the anode terminal of the EL device and a voltage line, the third switch transistor being controlled by the second gate driver circuit, the voltage line being configured to supply a reverse bias voltage for reverse biasing the anode terminal of the EL device,

the first switch transistor is configured to be controlled in an OFF state by the first gate driver circuit, when the second gate driver circuit controls the third switch transistor in a state for reverse biasing the anode terminal of the EL device, and
the second gate driver circuit is configured to turn the third switch transistor from an ON state for reverse biasing the anode terminal of the EL device to an OFF state, and, after a lapse of time, the first gate driver circuit is configured to turn the first switch transistor from the OFF state to an O

Assignees

• Joled Inc

Inventors

• Takahara Hiroshi
• Tsuge Hitoshi

Classifications

• G09G3/325

  the data current flowing through the driving transistor during a setting phase, e.g. by using a switch for connecting the driving transistor to the data driver · CPC title

• G09G3/2007

  Display of intermediate tones · CPC title

• G09G2300/0809

  Several active elements per pixel in active matrix panels · CPC title

• G09G2320/06

  Adjustment of display parameters · CPC title

• G09G2320/0606

  Manual adjustment · CPC title