EL display apparatus
An electroluminescent (EL) display apparatus and manufacturing method are provided. A display screen includes gate signal lines which are arranged to intersect source signal lines. A pixel corresponds to each intersection of the gate signal lines and the source signal lines. Each pixel includes: an EL device; a driving transistor to supply a current to the EL device; a first switch transistor through which the current is supplied by the driving transistor to the EL device; a second switch transistor provided to supply, to the driving transistor, an image signal supplied to a corresponding one of the source signal lines; a third switch transistor provided between a gate terminal and a drain terminal of the driving transistor; and a capacitor connected to the gate terminal of the driving transistor for holding the image signal. The third switch transistor has a multi-gate structure.
1. An electroluminescent (EL) display apparatus comprising:
a display screen including a plurality of gate signal lines which is arranged to intersect a plurality of source signal lines, and a pixel corresponding to each intersection of the plurality of gate signal lines and the plurality of source signal lines;
a source driver circuit connected to the plurality of source signal lines; and
a gate driver circuit which includes a first gate driver circuit and a second gate driver circuit,
wherein each pixel comprises:
an EL device;
a driving transistor to supply a current to the EL device;
a first switch transistor provided on a current path through which the current is supplied by the driving transistor to the EL device;
a second switch transistor provided to supply, to the driving transistor, an image signal supplied to a corresponding one of the plurality of source signal lines;
a third switch transistor provided between a gate terminal and a drain terminal of the driving transistor; and
a capacitor connected to the gate terminal of the driving transistor for holding the image signal,
the third switch transistor has a multi-gate structure,
the source driver circuit is configured to supply a signal voltage to the gate of the driving transistor to flow a current which is N times as large as a predetermined value to the EL device,
N is greater than one,
the first gate driver circuit includes a first gate signal line and the second gate driver circuit includes a second gate signal line,
the first gate signal line is an on/off signal for the first switch transistor and is connected to a gate terminal of the first switch transistor, and
the second gate signal line is an on/off signal for the second switch transistor and the third switch transistor and is connected to a gate terminal of the second switch transistor and a gate terminal of the third switch transistor.
2. The EL display apparatus according to claim 1 ,
wherein the third switch transistor is a p-channel transistor.
3. The EL display apparatus according to claim 1 ,
wherein the third switch transistor is a p-channel transistor configured to cause the capacitor to hold the image signal for one frame period.
4. The EL display apparatus according to claim 1 ,
wherein the driving transistor, the first switch transistor, the second switch transistor, and the third switch transistor are p-channel transistors.
5. The EL display apparatus according to claim 1 ,
wherein the source driver circuit is configured to supply the signal voltage to the gate of the driving transistor to flow the current which is N times as large as the predetermined value to the EL device to achieve a gray scale display indicated by the image signal.
6. The EL display apparatus according to claim 1 , further comprising:
a precharge circuit or a discharge circuit which forcibly charges or discharges the plurality of source signal lines.
7. The EL display apparatus according to claim 1 ,
wherein, by the first gate driver circuit and the second gate driver circuit, the first switch transistor is independently on/off controlled from the second switch transistor and the third switch transistor.
8. The EL display apparatus according to claim 7 ,
wherein the first gate driver circuit is configured to select a plurality of first gate signal lines simultaneously.
9. The EL display apparatus according to claim 1 ,
wherein an on-time of the EL device of the pixel is 1/M of one frame, and
M is greater than one.
10. The EL display apparatus according to claim 9 ,
wherein M is variable with respect to N for varying a brightness of the EL device during the one frame.
11. An electronic device, comprising:
the EL display apparatus according to claim 1 .
12. A method of manufacturing an electroluminescent (EL) display apparatus,
the EL display apparatus comprising:
a display screen including a plurality of gate signal lines which is arranged to intersect a plurality of source signal lines, and a pixel corresponding to each intersection of the plurality of gate signal lines and the plurality of source signal lines;
a source driver circuit connected to the plurality of source signal lines; and
a gate driver circuit which includes a first gate driver circuit and a second gate driver circuit,
wherein each pixel comprises:
an EL device;
a driving transistor to supply a current to the EL device;
a first switch transistor provided on a current path through which the current is supplied by the driving transistor to the EL device;
a second switch transistor provided to supply, to the driving transistor, an image signal supplied to a corresponding one of the plurality of source signal lines;
a third switch transistor provided between a gate terminal and a drain terminal of the driving transistor; and
a capacitor connected to the gate terminal of the driving transistor for holding the image signal,
the first gate driver circuit includes a first gate signal line and the second gate driver circuit includes a second gate signal line,
the first gate signal line is an on/off signal for the first switch transistor and is connected to a gate terminal of the first switch transistor, and
the second gate signal line is an on/off signal for the second switch transistor and the third switch transistor and is connected to a gate terminal of the second switch transistor and a gate terminal of the third switch transistor,
the method comprising:
fabricating the third switch transistor with a multi-gate structure; and
configuring the source driver circuit to supply a signal voltage to the gate of the driving transistor to flow a current which is N times as large as a predetermined value to the EL device, N being greater than one.
13. The method of manufacturing the EL display apparatus according to claim 12 ,
wherein an on-time of the EL device of the pixel is 1/M of one frame, and
M is greater than one.
14. The method of manufacturing the EL display apparatus according to claim 12 ,
wherein the third switch transistor is a p-channel transistor configured to cause the capacitor to hold the image signal for one frame period.
15. An electroluminescent (EL) display apparatus, comprising:
a display screen including a plurality of gate signal lines which is arranged to intersect a plurality of source signal lines, and a pixel corresponding to each intersection of the plurality of gate signal lines and the plurality of source signal lines; and
a gate driver circuit which includes a first gate driver circuit and a second gate driver circuit,
wherein each pixel comprises:
an EL device;
a driving transistor to supply a current to the EL device;
a first switch transistor provided on a current path through which the current is supplied by the driving transistor to the EL device;
a second switch transistor provided to supply, to the driving transistor, an image signal supplied to a corresponding one of the plurality of source signal lines;
a third switch transistor provided between a gate terminal and a drain terminal of the driving transistor; and
a capacitor connected to the gate terminal of the driving transistor for holding the image signal,
the third switch transistor has a multi-gate structure,
the first gate driver circuit includes a first gate signal line and the second gate driver circuit includes a second gate signal line,
the first gate signal line is an on/off signal for the first switch transistor and is connected to a gate terminal of the first switch transistor, and
the second gate signal line is an on/off signal for the second switch transistor and the third switch transistor and is connected to a gate terminal of the second switch transistor and a gate terminal of the third switch transistor.
16. The EL display apparatus according to claim 15 ,
wherein, by the first gate driver circuit and the second gate driver circuit, the first switch transistor is independently on/off controlled from the second switch transistor and the third switch transistor.
17. The EL display apparatus according to claim 15 , 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 the gate of the driving transistor to flow a current which is N times as large as a predetermined value to the EL device,
N is greater than one,
an on-time of the EL device of the pixel is 1/M of one frame, and
M is greater than one.
18. The EL display apparatus according to claim 15 ,
wherein the third switch transistor is a p-channel transistor configured to cause the capacitor to hold the image signal for one frame period.