Semiconductor circuits for driving current-driven display and display
View Patent ↗In a semiconductor circuit of a current output type, when display is performed by plural semiconductor circuit in one display panel, luminance unevenness for each block with a different semiconductor circuit occurs due to fluctuation in the semiconductor circuits. In current output stages 14 a and 14 b , current mirror circuits are constituted at both ends of a chip, and a reference current to be a reference of gradation display is supplied from both the ends. Moreover, by increasing a resistance value of a gate line of the current mirror circuit of distributing a current to each output, deviation of a transistor threshold value in the chip was compensated for, and output currents at left and right ends were matched. Moreover, reference currents were made the same by connecting resistors for reference current generation 11 c to 11 f each other at least between semiconductor circuits connected side by side, and fluctuation of current values across all semiconductor circuits decreased to 1% or less, whereby unevenness which occurred in boundaries of chips could be eliminated.
1. An active matrix type display device comprising:
a display including a matrix of pixels, each of the pixels having an organic luminous element and a driving transistor;
a driver circuit including a current output unit configured to output a current to be applied to each of the pixels; and
a reference current generation circuit configured to generate a reference current, wherein
the current output unit has transistor groups as output stages thereof, each of the transistor groups having one transistor or a plurality of transistors, so that the outputted current is applied to the driving transistor, and
the current outputted from at least one transistor of the transistor groups is changeable according to a magnitude of the generated reference current.
2. The active matrix type display device according to claim 1 , wherein
a value of (channel width)/(channel length) of the transistor of the transistor group is 0.01 or more and 0.6 or less.
3. The active matrix type display device according to claim 1 , further comprising a current path forming circuit which is supplied a current outputted from the transistor groups for a predetermined period.
4. The active matrix type display device according to claim 1 , wherein
a total resistance value of the gate line of the transistor groups is set to a value equal to or larger than a larger one of a value, which is found by dividing a voltage of a difference between a maximum value and a minimum value of a gate voltage with respect to a reference current value in a use process by a value of 0.5% of the reference current, and 1 KΩ, and equal to or smaller than 5 MΩ.
5. The active matrix type display device according to claim 1 , wherein
the driver circuit has a voltage output unit.
6. The active matrix type display device according to claim 1 , wherein
a change of the reference current is capable of setting according to control data.
7. An active matrix type display device comprising:
a display including a matrix of pixels, each of the pixels having an organic luminous element and a driving transistor;
a driver circuit including a current output unit configured to output a current to be applied to each of the pixels;
a reference current generation circuit configured to generate a reference current;
a first coupling circuit; and
a seconu coupling circuit, wherein
the current output unit has transistor groups as output stages thereof, each of the transistor groups having one transistor or a plurality of transistors, so that the outputted current is applied to the driving transistor, and
the first coupling circuit and the second coupling circuit are electrically coupled to a gate line of at least one transistor of the transistor groups, and are supplied the generated reference current.
8. The active matrix type display device according to claim 7 , wherein
a value of (channel width)/(channel length) of the transistor of the transistor group is 0.01 or more and 0.6 or less.
9. The active matrix type display device according to claim 7 , further comprising a current path forming circuit which is supplied a current outputted from the transistor groups for a predetermined period.
10. The active matrix type display device according to claim 7 , wherein
the driver circuit has a voltage output unit.
11. The active matrix type display device according to claim 7 , wherein
a change of the reference current is capable of setting according to control data.
12. An active matrix type display device comprising:
a display including a matrix of pixels, each of the pixels having an organic luminous element and a driving transistor;
a driver circuit including a voltage output unit configured to output a voltage to be applied to each of the pixels and a current output unit configured to output a current to be applied to each of the pixels;
a judgment circuit configured to judge whether the voltage output unit outputs the voltage or the current output unit outputs the current, wherein
the current output unit having has transistor groups as output stages thereof,
each of the transistor groups having one transistor or a plurality of transistors, so that the outputted current is applied to the driving transistor.
13. The active matrix type display device according to claim 12 , wherein
a value of (channel width)/(channel length) of the transistor of the transistor group is 0.01 or more and 0.6 or less.
14. The active matrix type display device according to claim 12 , further comprising a current path forming circuit which is supplied a current outputted from the transistor groups for a predetermined period.
15. The active matrix type display device according to claim 12 , wherein
a total resistance value of the gate line of the transistor groups is set to a value equal to or larger than a larger one of a value, which is found by dividing a voltage of a difference between a maximum value and a minimum value of a gate voltage with respect to a reference current value in a use process by a value of 0.5% of the reference current, and 1 KΩ, and equal to or smaller than 5 MΩ.
16. The active matrix type display device according to claim 12 , wherein
a period which the voltage output circuit is allowed to output for one horizontal scanning period is capable of setting.
17. A display device comprising:
a display including a matrix of pixels, each of the pixels having an organic luminous element;
a driver circuit including a current output unit configured to output a current to be applied to each of the pixels; and
a reference current generation circuit configured to generate a reference current, wherein
the current output unit has transistor groups as output stages thereof, each of the transistor groups having one transistor or a plurality of transistors,
the current outputted from at least one transistor of the transistor groups is changeable according to a magnitude of the generated reference current, and
a total resistance value of the gate line of the transistor groups is set to a value equal to or larger than a larger one of a value, which is found by dividing a voltage of a difference between a maximum value and a minimum value of a gate voltage with respect to a reference current value in a use process by a value of 0.5% of the reference current, and 1 KΩ, and equal to or smaller than 5 MΩ.
18. A display device comprising:
a display including a matrix of pixels, each of the pixels having an organic luminous element;
a driver circuit including a voltage output unit configured to output a voltage to be applied to each of the pixels and a current output unit configured to output a current to be applied to each of the pixels;
a judgment circuit configured to judge whether the voltage output unit outputs the voltage or the current unit outputs the current, wherein
the current output unit has transistor groups as output stages thereof, each of the transistor groups having one transistor or a plurality of transistors, and
a total resistance value of the gate line of the transistor groups is set to a value equal to or larger than a larger one of a value, which is found by dividing a voltage of a difference between a maximum value and a minimum value of a gate voltage with respect to a reference current value in a use process by a value of 0.5% of the reference current, and 1 KΩ, and equal to or smaller than 5 MΩ.