1. An organic light-emitting diode display device, comprising:
a data line;
first and second gate lines crossing the data line;
an emission line crossing the data line;
an organic light-emitting diode device having an anode electrode and a cathode electrode;
a high-level potential driving voltage source for supplying a high-level potential driving voltage to the anode electrode;
a first switch element for connecting a cathode electrode of the organic light-emitting diode device to a first node;
a second switch element for connecting the data line to a second node;
a third switch element for connecting the second node to a ground voltage source;
a driving element for adjusting a current flowing between the cathode electrode of the organic light-emitting diode device and the second node in accordance with a voltage of the first node;
a first capacitor connected between the second gate line and the first node; and
a second capacitor connected between the first node and the second node,
wherein the driving element includes a gate electrode connected to the first node, a source electrode connected to the second node, and a drain electrode connected to the cathode electrode of the organic light-emitting diode device.
2. The organic light-emitting diode display device as recited in claim 1, wherein the first switch element includes a gate electrode connected to the first gate line, a source electrode connected to the first node, and a drain electrode connected to the cathode electrode of the organic light-emitting diode device.
3. The organic light-emitting diode display device as recited in claim 1, wherein the second switch element includes a gate electrode connected to the second gate line, a source electrode connected to the data line, and a drain electrode connected to the second node.
4. The organic light-emitting diode display device as recited in claim 1, wherein the third switch element includes a gate electrode connected to the emission line, a source electrode connected to the ground voltage source, and a drain electrode connected to the second node.
5. A method of driving an organic light-emitting diode display device having a data line, first and second gate lines crossing the data line, an emission line crossing the data line, an organic light-emitting diode device having an anode electrode and a cathode electrode, a first switch element, a second switch element, a third switch element, a driving element, a first capacitor and a second capacitor, comprising:
supplying a high-level potential driving voltage to the anode electrode from a high-level potential driving voltage source;
connecting a cathode electrode of the organic light-emitting diode device to a first node through the first switch element in response to a first scanning pulse from the first gate line;
connecting the data line to a second node through the second switch element in response to a second scanning pulse from the second gate line;
connecting the second node to a ground voltage source through the third switch element in response to an emission pulse from the emission line;
adjusting a current flowing between the cathode electrode of the organic light-emitting diode device and the second node through the driving element in accordance with a voltage on the first node; and
emitting light from the organic light-emitting diode device,
wherein the first and second scanning pulses are at an active logic voltage during a first period, and the first and second scanning pulses are maintained at the active logic voltage during a second period.
6. The method of driving an organic light-emitting diode display device as recited in claim 5, wherein the emission pulse is maintained at a non-active logic voltage during the first and second periods.
7. The method of driving an organic light-emitting diode display device as recited in claim 5, further comprising:
supplying a pre-charge voltage to the data line during the first period, the pre-charge voltage is defined by a difference voltage between the high-level potential driving voltage and the threshold voltage of the organic light-emitting diode device such that the pre-charge voltage is charged onto the first node by turning-on the second switch element during the first period.
8. The method of driving an organic light-emitting diode display device as recited in claim 5, further comprising:
supplying an up-scaling current Idata defined by the following equation to the data line during the second period such that the up-scaling current is charged onto the second node by turning-on the second switch element during the second period,
I
data
=
I
OLED
=
K
DR
\u2061
(
Vgs
–
Vth
)
2
Vgs
=
I
data
K
DR
+
Vth
IOLED represents a current of the organic light-emitting diode device, Vgs represents a voltage applied between the gate electrode and the source electrode of the driving element, Vth represents a threshold voltage of the driving element and kDR represent a constant defined by mobility and a parasitic capacitance of the driving element.
9. The method of driving an organic light-emitting diode display device as recited in claim 8, wherein the up-scaling current is generated as a current larger than an integer multiple of a current flowing into the organic light-emitting diode device; and the integer multiple in a lower gray scale of a digital video data is larger than that in a higher gray scale of a digital video data, the low gray scale is less than a predetermined reference gray scale and the high gray scale is equal or larger than the predetermined reference gray scale.
10. The method of driving an organic light-emitting diode display device as recited in claim 5, further comprising:
changing the first and second scanning pulses into a non-active logic voltage during a third period, and maintained the first and second scanning pulses in a non-active logic voltage during a fourth period.
11. The method of driving an organic light-emitting diode display device as recited in claim 10, wherein during the third period, the first and second switch elements are turned-off in response to the non-active voltages of the scanning pulses; and
a voltage Vgs between the gate and the source of the driving element is changed as much as \u0394Vgs defined by the following equation, and a current IOLED flowing into the organic light-emitting diode device is changed by the following equation,
\u0394
\u2062
\u2062
Vgs
=
C
\u2062
\u2062
1
C
\u2062
\u2062
1
+
C
\u2062
\u2062
2
\u2062
(
\u0394
\u2062
\u2062
Vgate
\u2062
\u2062
2
–
\u0394
\u2062
\u2062
Vs
)
I
OLED
=
k
DR
\u2061
(
Vgs
–
\u0394
\u2062
\u2062
Vgs
–
Vth
)
2
kDR represents a constant defined by mobility and a parasitic capacitance of the driving element, Vgs represents a voltage applied between the gate electrode and the source electrode of the driving element, \u0394Vgs represents a variation of Vgs, Vth represents a threshold voltage of the driving element, C1 is a capacitance of the first capacitor, C2 is a capacitance of the second capacitor, \u0394Vgate2 represents a variation of a logic voltage of the second scanning pulse S21, and \u0394Vs represents a variation of a source voltage of the driving element.
12. The method of driving an organic light-emitting diode display device as recited in claim 10, further comprising:
maintaining the emission pulse at a non-active logic voltage during the third period.
13. The method of driving an organic light-emitting diode display device as recited in claim 12, further comprising:
changing the emission pulse into an active voltage during the fourth period.
14. The method of driving an organic light-emitting diode display device as recited in claim 13, wherein the third switch element is turned-on in response to an active voltage of the emission pulse to electrically form a current path between the driving element and the ground voltage source during the fourth period.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for performing finishing operations on at least one graphics area on a graphics sheet, the graphics sheet having a graphics side, an opposite process side, and reference features, the graphics side bearing the graphics area(s) and registration marks placed in predetermined positions with respect to the graphics area(s), the method comprising:
positioning the graphics sheet on a sheet-receiving surface;
sensing from the graphics side the positions of the registration marks at the time of the finishing operations;
determining from the sensed positions the coordinates of the graphics area(s) with respect to the sheet-receiving surface as if viewable from the process side; and
performing finishing operations from the process side of the graphics sheet based on such determination,
whereby such process-side finishing operations compensate for variations of the graphics area(s) at the time of the finishing operations.
2. The method of claim 1 wherein the variations include print registration errors, linear distortions, or non-linear distortions.
3. The method of claim 1 wherein the graphics sheet is positioned with the graphics side facing the sheet-receiving surface throughout the sensing, determining, and performing actions.
4. The method of claim 3 wherein a portion of the sheet-receiving surface is transparent and the positions of the registration marks are sensed through the transparent portion.
5. The method of claim 1 wherein the reference features have metrics and the method further comprises:
sensing from the graphics side the metrics of the reference features of the sheet;
sensing from the process side the metrics of the reference features; and
using the relative positions of the registration marks to the reference features to determine the coordinates of the graphics area(s) with respect to the sheet-receiving surface.
6. The method of claim 5 wherein the metrics of the reference features and the positions of the registration marks are sensed from the graphics side before the graphics sheet is positioned on the sheet-receiving surface for performing the finishing operations.
7. The method of claim 6 wherein the metrics of the reference features and the positions of the registration marks are sensed from the graphics side during translation of the graphics sheet in a plane parallel to the graphics sheet.
8. The method of claim 5 wherein the sensing of the positions of the registration marks from the graphics side includes sensing the positions of the registration marks not adjacent to the reference features.
9. The method of claim 5 wherein the metrics of the reference features and the positions of the registration marks are sensed from the graphics side by translating a sensor in a plane parallel to the graphics sheet.
10. The method of claim 9 wherein the sensing of the positions of the registration marks from the graphics side includes sensing the positions of the registration marks not adjacent to the reference features.
11. The method of claim 5 wherein the sensing of the metrics of the reference features from the graphics side includes sensing the positions of at least two corners of the graphics sheet.
12. The method of claim 11 wherein the sensing of the positions of the registration marks from the graphics side includes sensing the position(s) of at least one registration mark adjacent to each of the at least two corners of the graphics sheet.
13. The method of claim 11 wherein the sensing from the process side of the metrics of the reference features includes sensing the positions of the at least two corners of the graphics sheet.
14. The method of claim 5 further comprising:
automatically identifying the graphics sheet; and
selecting finishing operation instructions associated with the identified graphics sheet, thereby enabling graphics sheets printed with differing graphics areas to be automatically finished sequentially.
15. The method of claim 14 wherein the automatic identifying step includes reading a bar code on the graphics side of the graphics sheet.
16. The method of claim 5 further comprising determining whether the graphics sheet has been properly loaded to correspond to a set of finishing operation instructions and, if not, preventing the finishing operation from occurring.
17. An apparatus for performing finishing operations on at least one graphics area on a graphics sheet, the graphics sheet having a graphics side, an opposite process side, and reference features, the graphics side bearing the graphics area(s) and registration marks placed in predetermined positions with respect to the graphics area(s), the apparatus comprising:
a sheet-receiving surface;
a graphics-side sensor set for sensing from the graphics side the positions of the registration marks at the time of the finishing operations; and
a controller for determining from the sensed positions the coordinates of the graphics area(s) with respect to the sheet-receiving surface as if viewable from the process side and for controlling finishing operations from the process side of the graphics sheet based on such determination,
whereby such process-side finishing operations compensate for variations of the graphics area(s) at the time of the finishing operations.
18. The apparatus of claim 17 wherein the variations include print registration errors, linear distortions, or non-linear distortions.
19. The apparatus of claim 17 wherein at least a portion of the sheet receiving surface is transparent and the graphics-side sensor set senses the positions of the registration marks through the transparent portion.
20. The apparatus of claim 17 wherein the reference features have metrics and the graphics-side sensor set senses from the graphics side the metrics of the reference features of the sheet, the apparatus further comprising a process-side sensor to sense the metrics of the reference features from the process side.
21. The apparatus of claim 17 wherein the graphics-side sensor set includes at least one camera.
22. The apparatus of claim 17 further including a sheet actuator to translate the graphics sheet in a plane parallel to the graphics sheet during sensing from the graphics side.
23. The apparatus of claim 17 further including lifting and holding apparatus to lift and hold the graphics sheet during the sensing from the graphics side.