Current drive circuit and display device using same pixel circuit, and drive method
First Claim
1. A current drive circuit for supplying a drive current to a driven object, including:
- a control line,a signal line to which a signal current having a current level in accordance with information is supplied,a receiving part for fetching the signal current from the signal line when the control line selected,a converting part for converting a current level of the fetched signal current to a voltage level and holding the same, anda drive part for converting the held voltage signal to a current signal and outputting the drive current, whereinthe receiving part includes a fetch use insulating gate type field effect transistor having a control terminal, a first terminal, and a second terminal, the first terminal connected to a first terminal of the conversion use transistor the second terminal connected to the signal line, and the control terminal connected to the control line, andthe converting part includes a switch use transistor inserted between the first terminal and control terminal of the conversion use transistor.
0 Assignments
0 Petitions
Accused Products
Abstract
A display device including a current drive circuit capable of stably and correctly supplying an intended current to a light emitting element of each pixel without being affected by variations in characteristics of an active element inside the pixel and as a result capable of displaying a high quality image, wherein each pixel comprises a receiving use transistor TFT3 for fetching a signal current Iw from a data line DATA when a scanning line SCAN-A is selected, a conversion use transistor TFT1 for once converting a current level of a fetched signal current Iw to a voltage level and holding the same, and a drive use transistor TFT2 for passing a drive current having a current level in accordance with the held voltage level through a light emitting element OLED. The conversion use thin film transistor TFT1 generates a converted voltage level at its own gate by passing the signal current Iw fetched by the TFT3 through its own channel. A capacitor C holds the voltage level created at the gate of the TFT1. The TFT2 passes the drive current having a current level in accordance with the held voltage level through the light emitting element OLED.
-
Citations
57 Claims
-
1. A current drive circuit for supplying a drive current to a driven object, including:
-
a control line, a signal line to which a signal current having a current level in accordance with information is supplied, a receiving part for fetching the signal current from the signal line when the control line selected, a converting part for converting a current level of the fetched signal current to a voltage level and holding the same, and a drive part for converting the held voltage signal to a current signal and outputting the drive current, wherein the receiving part includes a fetch use insulating gate type field effect transistor having a control terminal, a first terminal, and a second terminal, the first terminal connected to a first terminal of the conversion use transistor the second terminal connected to the signal line, and the control terminal connected to the control line, and the converting part includes a switch use transistor inserted between the first terminal and control terminal of the conversion use transistor. - View Dependent Claims (2, 3)
-
-
4. A current drive circuit for supplying a drive current to a driven object, including:
-
at least one control line, a signal line to which a signal current having a current level in accordance with information is supplied, a conversion use insulating gate type field effect transistor with a source connected to a reference potential, a fetch use insulating gate type field effect transistor connected between a drain of said conversion use insulating gate type field effect transistor and said signal line and having a gate connected to a said control line, a drive use insulating gate type field effect transistor connected between the reference potential and said driven object, a capacitor having a first electrode connected in common to a gate of said conversion use insulating gate type field effect transistor and a gate of said drive use insulating gate type field effect transistor and having a second electrode connected to the reference potential, and a switch use insulating gate type field effect transistor connected between a gate and drain of said conversion use insulating gate type field effect transistor and having a gate connected to said control line.
-
-
5. A current drive circuit for supplying a drive current to a driven object, including:
-
at least one control line, a signal line to which a signal current having a current level in accordance with information is supplied, a conversion use insulating gate type field effect transistor with a source connected to a reference potential, a fetch use insulating gate type field effect transistor connected between a drain of said conversion use insulating gate type field effect transistor and said signal line and having a gate connected to said control line, a drive use insulating gate type field effect transistor connected between the reference potential and said driven object, a capacitor having a first electrode connected to a gate of said drive use insulating gate type field effect transistor and having a second electrode connected to a reference potential, and a switch use insulating gate type field effect transistor connected between a gate of said conversion use insulating gate type field effect transistor and a connecting point of a gate of said drive use insulating gate type field effect transistor and a first electrode of said capacitor and having a gate connected to said control line, wherein a control terminal of said fetch use insulating gate type field effect transistor and a control terminal of said switch use insulating gate type field effect transistor are connected to different control lines.
-
-
6. A display device, comprising:
-
a scanning line, a data line to which a signal in accordance with brightness information is supplied, and a pixel comprising a display element formed at an intersecting portion of said data line and said scanning line, said pixel comprising a receiving part for fetching the signal supplied to the data line when the scanning line is selected, a converting and holding part for converting and holding the fetched signal, and a drive part for converting the held signal and supplying it to said display element, wherein said converting and holding part comprises a plurality of transistors provided with control terminals and a plurality of capacitors connected to the control terminals.
-
-
7. A display device comprising:
-
a scanning line, a data line to which a current signal in accordance with brightness information is supplied, and a pixel comprising an organic layer formed at an intersecting portion of said data line and said scanning line, said pixel comprising a receiving part for fetching the current signal supplied to the data line when the scanning line is selected, a converting and holding part for converting the fetched current signal to a voltage and holding the same, and a drive part for converting the held voltage signal and supplying a current to said display element, wherein said converting and holding part comprises a first transistor provided with a control terminal and one end of a capacitor connected to said control terminal, wherein said converting and holding part comprises a second transistor connected between the first terminal of said first transistor and said control terminal. - View Dependent Claims (8, 9, 10, 11)
-
-
12. A display device, comprising:
-
a scanning line, a data line to which a signal in accordance with brightness information is supplied, and a pixel comprising a display element formed at an intersecting portion of said data line and said scanning line, said pixel comprising a receiving part for fetching the signal supplied to the data line when the scanning line is selected, a converting and holding part for converting and holding the fetched signal, and a drive part for converting the held signal and supplying it to said display element, wherein said converting and holding part comprises a first transistor provided with a control terminal and one end of a capacitor connected to said control terminal, wherein said converting and holding part comprises a second transistor connected between the first terminal of said first transistor and said control terminal. - View Dependent Claims (13, 14, 15, 16)
-
-
17. A display device comprising
a scanning line drive circuit for successively selecting scanning lines, a data line drive circuit including a current source for generating a signal current having a current level in accordance with brightness information and successively supplying the same to data lines, and a plurality of pixels arranged at intersecting portions of the scanning lines and the data lines and including current driven type light emitting elements emitting light by receiving the supply of the drive current, wherein each pixel comprises a receiving part for fetching the signal current from a data line when the scanning line is selected, a converting part for converting a current level of the fetched signal current to a voltage level and holding the same, and a drive part for passing a drive current having a current level in accordance with the held voltage level through the light emitting element, wherein an initial value setting element for setting said data to an initial value before said scanning line is selected is connected between said data line and a predetermined potential, wherein: -
the drive part includes an insulating gate type field effect transistor having a gate, a drain, and a source, the converting part is provided with a capacitor connected to the gate of the thin film transistor and holding the voltage level, and the adjusting means comprises an additional capacitor connected to that capacitor and downwardly adjusts the level of the voltage to be applied to the gate of the insulating gate type field effect transistor held at that capacitor. - View Dependent Claims (18, 19, 20)
-
-
21. A display device comprising a scanning line drive circuit for successively selecting scanning lines,
a data line drive circuit including a current source for generating a signal current having a current level in accordance with brightness information and successively supplying the same to data lines, and a plurality of pixels arranged at intersecting portions of the scanning lines and the data lines and including current driven type light emitting elements emitting light by receiving the supply of the drive current, wherein each pixel comprises a conversion use insulating gate type field effect transistor having a source connected to a reference potential, a fetch use insulating gate type field effect transistor inserted between the drain of the conversion use insulating gate type field effect transistor and the data line and having a gate connected to a scanning line, a drive use insulating gate type field effect transistor connected between a reference potential and a light emitting element, a capacitor having a first electrode connected in common to a gate of the conversion use insulating gate type field effect transistor and a gate of the drive use insulating gate type field effect transistor and having a second electrode connected to a reference potential, and a switch use insulating gate type field effect transistor connected between a gate and drain of said conversion use insulating gate type field effect transistor and having a gate connected to a scanning line.
-
22. A display device comprising
a scanning line drive circuit for successively selecting scanning lines, a data line drive circuit including a current source for generating a signal current having a current level in accordance with brightness information and successively supplying the same to data lines, and a plurality of pixels arranged at intersecting portions of the scanning lines and the data lines and including current driven type light emitting elements emitting light by receiving the supply of the drive current, wherein each pixel comprises a conversion use insulating gate type field effect transistor having a source connected to a reference potential, a fetch use insulating gate type field effect transistor connected between the drain of the conversion use insulating gate type field effect transistor and the data line and having a gate connected to a scanning line, a drive use insulating gate type field effect transistor connected between a reference potential and a light emitting element, a capacitor having a first electrode connected to a gate of the drive use insulating gate type field effect transistor and having a second electrode connected to a reference potential, and a switch use insulating gate type field effect transistor connected between a gate of said conversion use insulating gate type field effect transistor and a connecting point between a gate of said drive use insulating gate type field effect transistor and a first electrode of said capacitor and having a gate connected to a scanning line, wherein the control terminal of the fetch use insulating gate type field effect transistor and the control terminal of the switch use insulating gate type field effect transistor are connected to different scanning lines.
-
26. A display device comprising
a scanning line drive circuit for successively selecting scanning lines, a data line drive circuit including a current source for generating a signal current having a current level in accordance with brightness information and successively supplying the same to data lines, and a plurality of pixels arranged at intersecting portions of the scanning lines and the data lines and including current driven type light emitting elements emitting light by receiving the supply of the drive current, wherein each pixel comprises a receiving part for fetching the signal current from a data line when the scanning line is selected, a converting part for converting a current level of the fetched signal current to a voltage level and holding the same, and a drive part for passing a drive current having a current level in accordance with the held voltage level through the light emitting element, wherein: -
the receiving part includes a fetch use insulating gate type field effect transistor inserted between the drain of the conversion use insulating gate type field effect transistor and the data line, and the converting part includes a switch use insulating late type field effect transistor inserted between the drain and the gate of the conversion use insulating gate type field effect transistor. - View Dependent Claims (27, 28, 29, 30, 31)
-
-
32. A pixel circuit for driving a current-driven type light emitting element arranged at an intersecting portion of a data line supplying a signal current of a current level in accordance with brightness information and a scanning line supplying a selection pulse and emitting light by the drive current, comprising
a receiving part for fetching the signal current from said data line in response to a selection pulse from said scanning line, a converting part for converting a current level of the fetched signal current to a voltage level and holding the same, and a drive part for passing a drive current having a current level in accordance with the held voltage level through the light emitting element, wherein: -
the receiving part includes a fetch use insulating gate type field effect transistor inserted between the drain of the conversion use insulating gate type field effect transistor and the data line and the converting part includes a switch use insulating gate type field effect transistor inserted between the drain and the gate of the conversion use insulating gate type field effect transistor. - View Dependent Claims (33, 34, 35, 36, 37)
-
-
38. A pixel circuit for driving a current-driven type light emitting element arranged at an intersecting portion of a data line supplying a signal current of a current level in accordance with brightness information and a scanning line supplying a selection pulse and emitting light by the drive current, comprising
a receiving part for fetching the signal current from said data line in response to a selection pulse from said scanning line, a converting part for converting a current level of the fetched signal current to a voltage level and holding the same, and a drive part for passing a drive current having a current level in accordance with the held voltage level through the light emitting element, and an adjusting means for downwardly adjusting the voltage level held by the converting part and supplying the same to the drive part to tighten the black level of the brightness of each pixel, wherein the drive part includes an insulating gate type field effect transistor having a gate, a drain, and a source, the converting part is provided with a capacitor connected to the gate of the thin film transistor and holding the voltage level, and the adjusting means comprises an additional capacitor connected to that capacitor and downwardly adjusts the level of the voltage to be applied to the gate of the insulating gate type field effect transistor held at that capacitor.
-
40. A pixel circuit for driving a current-driven type light emitting element arranged at an intersecting portion of a data line supplying a signal current of a current level in accordance with brightness information and a scanning line supplying a selection pulse and emitting light by the drive current, comprising
a conversion use insulating gate type field effect transistor having a source connected to a reference potential, a fetch use insulating gate type field effect transistor inserted between the drain of the conversion use insulating gate type field effect transistor and the data line and having a gate connected to a scanning line, a drive use insulating gate type field effect transistor connected between a reference potential and a light emitting element, a capacitor having a first electrode connected in common to a gate of the conversion use insulating gate type field effect transistor and a gate of the drive use insulating gate type field effect transistor and having a second electrode connected to a reference potential, and a switch use insulating gate type field affect transistor connected between a gate and drain of said conversion use insulating gate type field effect transistor and having a gate connected to a scanning line.
-
41. A pixel circuit for driving a current-driven type light emitting element arranged at an intersecting portion of a data line supplying a signal current of a current level in accordance with brightness information and a scanning line supplying a selection pulse and emitting light by the drive current, comprising
a conversion use insulating gate type field effect transistor having a source connected to a reference potential, a fetch use insulating gate type field effect transistor connected between the drain of the conversion use insulating gate type field effect transistor and the data line and having a gate connected to a scanning line, a drive use insulating gate type field effect transistor connected between a reference potential and a light emitting element, a capacitor having a first electrode connected to a gate of the drive use insulating gate type field effect transistor and having a second electrode connected to a reference potential, and a switch use insulating gate type field effect transistor connected between a gate of said conversion use insulating gate type field effect transistor and a connecting point between a gate of said drive use insulating gate type field effect transistor and a first electrode of said capacitor and having a gate connected to a scanning lines, wherein the control terminal of the fetch use insulating gate type field effect transistor and the control terminal of the switch use insulating gate type field effect transistor are connected to different scanning lines.
-
44. A method of driving a light emitting element for driving a current-driven type light emitting element arranged at an intersecting portion of a data line supplying a signal current of a current level in accordance with brightness information and a scanning line supplying a selection pulse and emitting light by the drive current, comprising
a receiving routine for fetching the signal current from said data line in response to a selection pulse from said scanning line, a converting routine for converting a current level of the fetched signal current to a voltage level and holding the same, a drive routine for passing a drive current having a current level in accordance with the held voltage level through the light emitting elements, wherein the converting routine includes a routine using a conversion use insulating gate type field effect transistor provided with a gate, a source, a drain, and a channel and a capacitor connected to the gate, in the routine, the conversion use insulating gate type field effect transistor creates the voltage level converted by passing the fetched signal current though the channel in the receiving routine at the gate, and the capacitor holds voltage level created at the gate, wherein the converting routine includes a routine using a switch use insulating gate type field effect transistor inserted between the drain and the gate of the conversion use insulating gate type field effect transistor, in the routine, the switch use insulating gate type field effect transistor becomes conductive when converting the current level of the signal current to the voltage level and electrically connects the drain and the gate of the conversion use insulating gate type field effect transistor to create the voltage level with the source as the reference at the gate, and the switch use insulating gate type field effect transistor is cut off and separates the gate of the conversion use insulating gate type field effect transistor and the capacitor connected to this from the drain when the capacitor holds the voltage level.
Specification