DISPLAY APPARATUS

• US 20070285359A1
• Filed: 05/02/2007
• Published: 12/13/2007
• Est. Priority Date: 05/16/2006
• Status: Abandoned Application

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Inventors: Ono, Shinya
• Application Number:
  US11/743,179
• Publication Number:
  US 20070285359A1
• Time in Patent Office: Days
• US Class Current: 345/76
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 2300/0866 by means of changes in the pixel supply voltage
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element

Abstract

A display including a plurality of pixels in matrix, wherein each pixel includes first and second power source lines; a switching device for controlling writing of a signal voltage supplied via a signal line; a capacitor for storing the signal voltage supplied via the switching device; an n-type driver device having a gate electrode and first and second electrodes for providing current corresponding to the signal voltage stored by the capacitor; a light emitting device having an anode and a cathode for emitting light in response to the current. The display makes use of storing a voltage related to the threshold voltage of the driving device during a second portion of the operating time.

Claims

1. A display including a plurality of pixels in matrix, wherein each pixel comprising:

first and second power source lines;

a switching device for controlling writing of a signal voltage supplied via a signal line;

a capacitor for storing the signal voltage supplied via the switching device;

an n-type driver device having a gate electrode and first and second electrodes for providing current corresponding to the signal voltage stored by the capacitor;

a light emitting device having an anode and a cathode for emitting light in response to the current wherein the driver device and the light emitting device are arranged in series between the first and second power source lines such that the first electrode of the driver device is connected between the light emitting device and the second electrode of the driver device and the cathode of the light emitting device is connected between the anode of the light emitting device and the driver device and the one side of the capacitor is connected to the gate electrode of the driver device and other side of the capacitor is connected between the first electrode of the driver device and the light emitting device;

first means for causing light emission during a first portion of the operating time; and

second means for detecting and storing a voltage related to the threshold voltage of the driving device during a second portion of the operating time.

2. The display according to claim 1 where the second means causes the switching device to be in a conducting state during detection of the drive threshold voltage.

3. The display according to claim 1 where the second means causes the light emitting device to be in a non-conducting state during detection of the drive threshold voltage.

4. The display according to claim 1, wherein the first means supplies a first voltage which is positive between the first and second power source lines for causing light emission and the second means supplies a second voltage between the first and second power supply lines for detecting the voltage related to the threshold voltage of the driving device where the second voltage is lower than the first voltage.

5. A display including a plurality of pixels in matrix, wherein each pixel comprising:

first and second power source lines;

a switching device for controlling writing of a signal voltage supplied via a signal line;

a capacitor for storing the signal voltage supplied via the switching device;

a p-type driver device having a gate electrode and first and second electrodes for providing current corresponding to the signal voltage stored by the capacitor;

a light emitting device having an anode and a cathode for emitting light in response to the current wherein the driver device and the light emitting device are arranged in series between the first and second power source lines such that the first electrode of the driver device is connected between the light emitting device and the second electrode of the driver device and the anode of the light emitting device is connected between the cathode of the light emitting device and the driver device and the one side of the capacitor is connected to the gate electrode of the driver device and other side of the capacitor is connected between the first electrode of the driver device and the light emitting device;

first means for causing light emission during a first portion of the operating time; and

second means for detecting and storing a voltage related to the threshold voltage of the driving device during a second portion of the operating time.

6. The display according to claim 5 where the second means causes the switching device to be in a conducting state during detection of the drive threshold voltage.

7. The display according to claim 5 where the second means causes the light emitting device to be in a non-conducting state during detection of the drive threshold voltage.

8. The display according to claim 5, wherein the first means supplies a first voltage which is negative between the first and second power source lines for causing light emission and the second means supplies a second voltage between the first and second power source lines for detecting the voltage related to the threshold voltage of the driving device where the second voltage is higher than the first voltage.