ORGANIC ELECROLUMINESCENCE DISPLAY APPARATUS, METHOD OF PRODUCING THE SAME, AND METHOD OF REPAIRING A DEFECT

• US 20070273294A1
• Filed: 05/11/2007
• Published: 11/29/2007
• Est. Priority Date: 05/23/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Nagayama, Kohei
• Granted Patent: US 7,728,797 B2
• Time in Patent Office: Days
• US Class Current: 315/169.300
• 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 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2330/08 Fault-tolerant or redundant circuits, or circuits in which repair of defects is prepared
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• CPC Class Codes: G09G 3/3225 using an active matrix
• CPC Class Codes: H10K 71/861 Repairing

Abstract

Provided is an organic EL display apparatus capable of opening and breaking a defective portion without degrading a normal portion of a pixel, and a method of producing the same. The method of producing an organic EL display apparatus in which a plurality of pixels including organic EL devices are arranged includes the steps of: forming an organic EL device formed of a light emitting layer made of an organic compound between a cathode electrode and an anode electrode (Step S1); detecting a defective pixel in which a cathode electrode and an anode electrode are short-circuited (Step 2); and repairing the defective pixel to be opened by selectively applying a voltage between the cathode electrode and the anode electrode with respect to the defective pixel (Step S3).

Claims

1. A method of producing an organic electroluminescence display apparatus comprising a plurality of organic electroluminescence light emitting devices, comprising the steps of:

(1) forming the plurality of organic electroluminescence light emitting devices and a drive circuit for driving each of the organic electroluminescence light emitting devices on a substrate;

(2) measuring one of a light emission amount when a current is supplied from the drive circuit and a current amount when a voltage of a polarity opposite to a polarity of a voltage applied during light emission is applied to the organic electroluminescence light emitting device, with respect to each of the plurality of organic electroluminescence light emitting devices,

(3) specifying a defective organic electroluminescence light emitting device in which one of the light emission amount and the current amount is not usual; and

(4) repairing the defective organic electroluminescence light emitting device by supplying a current to the defective organic electroluminescence light emitting device from the drive circuit.

2. The method according to claim 1, wherein the step of specifying the defective organic electroluminescence light emitting device comprises detecting a position of an organic electroluminescence light emitting device in which a light emission amount is smaller than a predetermined light emission amount among the plurality of organic electroluminescence light emitting elements by an optical unit, when a current is supplied to all the plurality of organic electroluminescence light emitting elements from the drive circuit.

3. The method according to claim 1, wherein the step of specifying the defective organic electroluminescence light emitting device in which the current amount is unusual comprises detecting an organic electroluminescence light emitting device in which the current amount is larger than a predetermined current amount.

4. The method according to claim 1, wherein the step of repairing the defective organic electroluminescence light emitting device comprises repeating measurement of a current amount obtained when the voltage of a polarity opposite to the polarity of voltage of light emission is applied and supply of a current for repair from the drive circuit, with respect to the defective organic electroluminescence light emitting device, by increasing the current for repair gradually.

5. The method according to claim 1, wherein the step of repairing the defective organic electroluminescence light emitting device comprises applying a predetermined voltage to all the defective organic electroluminescence light emitting devices for a predetermined period of time.

6. The method according to claim 1, further comprising aging after the steps (1) to (3).

7. The method according to claim 1, wherein:

the organic electroluminescence display apparatus comprises a plurality of signal lines, a plurality of scanning lines, a plurality of voltage supply lines, and a common electrode on the substrate,

the organic electroluminescence light emitting device has one electrode connected to the common electrode; and

the drive circuit comprises;

a switching transistor whose source is connected to one of the plurality of signal lines and whose gate is connected to one of the plurality of scanning lines;

an operation transistor whose gate is connected to a drain of the switching transistor, whose source is connected to the voltage supply line, and whose drain is connected to the other electrode of the organic electroluminescence light emitting device; and

a holding capacitor provided between the gate and the source of the operation transistor, for holding a potential between the gate and the source of the operation transistor.

8. The method according to claim 7, wherein:

the step of specifying the organic electroluminescence light emitting device in which the current amount is unusual comprises steps of;

turning off the operation transistors of all the drive circuits; and

turning on the operation transistors successively, changing a potential of the common electrode from a potential applied to the common electrode during light emission to a potential of the voltage supply line to apply a voltage to the organic electroluminescence light emitting device of an opposite polarity to the voltage applied to the organic electroluminescence light emitting device during light emission, measuring a current through the organic electroluminescence light emitting device in a direction opposite to a direction of the current flowing through the organic electroluminescence light emitting device during light emission, and determining by the measured current whether the rectification characteristics of the organic electroluminescence light emitting device is unusual.

9. An organic electroluminescence display apparatus including a plurality of electroluminescence light emitting devices, comprising:

a plurality of organic electroluminescence light emitting devices formed on a substrate;

a drive circuit for driving each of the organic electroluminescence light emitting devices;

a unit for applying a voltage of a polarity opposite to a polarity obtained during light emission, to each of the plurality of organic electroluminescence light emitting devices;

a unit for measuring an amount of a current flowing to the organic electroluminescence light emitting device applied with the voltage of the opposite polarity;

a unit for determining the defective organic electroluminescence light emitting device from the measured current amount; and

a unit for repairing the defective organic electroluminescence light emitting device by supplying a current from the drive circuit to the defective organic electroluminescence light emitting device.

10. The organic electroluminescence display apparatus according to claim 9 further comprising:

a plurality of signal lines;

a plurality of scanning lines;

a plurality of voltage supply lines; and

a common electrode on the substrate,

wherein the drive circuit comprises;

a switching transistor whose source is connected to one of the plurality of signal lines and whose gate is connected to one of the plurality of scanning lines;

an operation transistor whose gate is connected to a drain of the switching transistor, whose source is connected to the voltage supply line, and whose drain is connected to the other electrode of the organic electroluminescence light emitting device; and

a holding capacitor provided between the gate and the source of the operation transistor, for holding a voltage between the gate and the source of the operation transistor.

11. The organic electroluminescence display apparatus according to claim 10, wherein the unit for applying a voltage of a polarity opposite to a polarity obtained during light emission comprises a circuit for changing a potential of the common electrode from a potential obtained during light emission to a potential of the voltage supply line in a state where a voltage for turning on the operation transistor with respect to one of the plurality of organic electroluminescence light emitting devices is held in the holding capacitor, and a voltage for turning off the operation transistor with respect to another organic electroluminescence light emitting device is held in the holding capacitor.

12. The organic electroluminescence display apparatus according to claim 9, the unit for measuring an amount of a current comprises:

a current measurement circuit provided outside the substrate; and

a switch for connecting the signal lines to the current measurement circuit.

13. A method of repairing a defect of an organic electroluminescence display apparatus including a plurality of organic electroluminescence light emitting devices arranged therein, the method comprising the steps of:

detecting a position of an organic electroluminescence light emitting device having a short-circuited portion among the plurality of organic electroluminescence light emitting devices; and

selectively supplying a current to the organic electroluminescence light emitting device provided at the detected position to break the short-circuited portion.