DISPLAY DEVICE AND METHOD OF DRIVING THE SAME

• US 20120327063A1
• Filed: 05/09/2012
• Published: 12/27/2012
• Est. Priority Date: 06/23/2011
• Status: Active Grant

• Current Assignee: JDI Design and Development GK
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: IZAWA, Yosuke, KATO, Toshiyuki, EBISUNO, Kouhei, ONO, Shinya, NAKAMURA, Tetsurou
• Granted Patent: US 9,275,572 B2
• Time in Patent Office: Days
• US Class Current: 345/212
• CPC Class Codes: G09G 2320/0223 Compensation for problems related to R-C delay and attenuation in electrodes of matrix panels, e.g. in gate electrodes or on-substrate video signal electrodes
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2330/02 Details of power systems and of start or stop of display operation
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]

Abstract

Display device includes: a power supplying unit which outputs at least a high-side or low-side output potential; an organic EL display unit which includes pixels and receives power supply from the power supplying unit; two or more detecting lines for transmitting a high-side or low-side applied potential applied to two or more pixels; a relay unit which outputs the high-side or low-side applied potentials transmitted by the detecting lines, to output lines fewer in number than the detecting lines; and a regulating unit which regulates at least the high-side or low-side output potential to be outputted by the power supplying unit, such that any one of potential difference between a reference potential and the high-side applied potential from the relay unit, potential difference between the reference potential and the low-side applied potential, and potential difference between the high-side applied potential and the low-side applied potential reaches a predetermined potential difference.

Claims

1. A display device comprising:

a power supplying unit configured to output at least one of a high-side output potential and a low-side output potential;

a display unit in which a plurality of pixels are arranged and which receives power supply from the power supplying unit;

two or more detecting lines each of which has one end connected to a corresponding one of two or more pixels inside the display unit, and is for transmitting a high-side applied potential or a low-side applied potential that is applied to the corresponding one of the two or more pixels;

a relay unit connected to the other end of each of the two or more detecting lines and to one end of one or more output lines which are fewer in number than the two or more detecting lines, and configured to output, to the one or more output lines, at least one applied potential out of the two or more high-side applied potentials or at least one applied potential out of the two or more low-side applied potentials, the high-side and low-side applied potentials being transmitted by the two or more detecting lines; and

a regulating unit connected to the relay unit via the one or more output lines and configured to regulate at least one of the high-side output potential and the low-side output potential to be outputted by the power supplying unit, such that any one of the following potential differences reaches a predetermined potential difference;

a potential difference between a reference potential and the high-side applied potential outputted by the relay unit;

a potential difference between the reference potential and the low-side applied potential outputted by the relay unit; and

a potential difference between the high-side applied potential and the low-side applied potential,

wherein the display unit and the relay unit are provided on the same substrate.

2. The display device according to claim 1, further comprising

a detecting circuit connected to the other end of each of the one or more output lines and to the regulating unit,

wherein the detecting circuit is configured to detect and select, from among the applied potentials outputted by the relay unit, at least one of a lowest applied potential out of the high-side applied potentials and a highest applied potential out of the low-side applied potentials, and to output the selected at least one applied potential to the regulating unit.

3. The display device according to claim 1,

wherein the relay unit includes, internally, a detecting circuit connected to the other end of each of the one or more output lines, and

the detecting circuit is configured to detect and select, from among the applied potentials transmitted by the two or more detecting lines, at least one of a lowest applied potential out of the high-side applied potentials and a highest applied potential out of the low-side applied potentials, and to output the selected at least one applied potential to the one or more output lines.

4. The display device according to claim 1,

wherein the relay unit is configured to time-divide the applied potentials transmitted by the two or more detecting lines, and sequentially output the time-divided applied potentials to the one or more output lines, and

the regulating unit is configured to regulate at least one of the high-side output potential and the low-side output potential to be outputted by the power supplying unit, such that at least one of the following potential differences reaches the predetermined potential difference:

a potential difference between the reference potential and a lowest applied potential out of the high-side applied potentials; and

a potential difference between the reference potential and a highest applied potential out of the low-side applied potentials, the high-side and low-side applied potentials being included in the applied potentials outputted by the relay unit.

5. The display device according to claim 1,

wherein the relay device is configured to convert, into digital data, the applied potentials inputted to the relay device as analog data, and output the applied potentials as the digital data.

6. The display device according to claim 1,

wherein each of the pixels includes a driver and a luminescence element,

the driver includes a source electrode and a drain electrode,

the luminescence element includes a first electrode and a second electrode, the first electrode being connected to one of the source electrode and the drain electrode of the driver,

the high-side applied potential is applied to one of the second electrode and the other of the source electrode and the drain electrode, and

the low-side applied potential is applied to the other of the second electrode and the other of the source electrode and the drain electrode.

7. The display device according to claim 6,

wherein the second electrode forms part of a common electrode provided in common to the pixels,

the common electrode is electrically connected to the power supplying unit so that a potential is applied to the common electrode from a periphery of the common electrode, and

at least a predetermined one of the two or more pixels is disposed near a center of the display unit.

8. The display device according to claim 7,

wherein the second electrode comprises a transparent conductive material including a metal oxide.

9. The display device according to claim 6,

wherein the luminescence element is an organic electroluminescence (EL) element.

10. A method of driving a display device including a power supplying unit which outputs at least one of a high-side output potential and a low-side output potential, a display device in which a plurality of pixels are arranged and which receives power supply from the power supplying unit, and two or more detecting lines each of which has one end connected to a corresponding one of two or more pixels inside the display unit, and is for transmitting a high-side applied potential or a low-side applied potential applied to the corresponding one of the two or more pixels, the method comprising:

outputting, to one or more output lines, at least one applied potential out of the high-side applied potentials or at least one applied potential out of the low-side applied potentials, the one or more output lines being fewer in number than the two or more detecting lines, and the high-side and low-side applied potentials being transmitted by the two or more detecting lines; and

regulating at least one of the high-side output potential and the low-side output potential such that any one of the following potential differences reaches a predetermined potential difference;

a potential difference between a reference potential and the high-side applied potential outputted in the outputting;

a potential difference between the reference potential and the low-side applied potential outputted in the outputting; and

a potential difference between the high-side applied potential and the low-side applied potential.