OLED driving characteristic detection circuit and OLED display device including the same

Patent metadata

Field	Value
Publication number	US-11335272-B2
Application number	US-202016793466-A
Country	US
Kind code	B2
Filing date	Feb 18, 2020
Priority date	Aug 5, 2019
Publication date	May 17, 2022
Grant date	May 17, 2022

Abstract

An organic light-emitting diode (OLED) driving characteristic detection circuit is provided. The OLED driving characteristic detection circuit comprising a first current integrator receiving a first current via a first sensing channel and outputting a first sampling voltage based on the first current, a second current integrator receiving a second current via a second sensing channel and outputting a second sampling voltage based on the second current, and a sampling circuit receiving the first and second sampling voltages, followed by storing and holding the first and second sampling voltages, and removing common noise components included in the first and second sampling voltages, a third sampling capacitor and a fourth sampling capacitor which are connected to an output terminal of the second current integrator and store and hold the second sampling voltage, and a plurality of switches which connect first ends of the first sampling capacitor to the fourth sampling capacitor.

First claim

What is claimed is:

1. An organic light-emitting diode driving characteristic detection circuit comprising:
a first current integrator configured to receive a first current via a first sensing channel and output a first sampling voltage based on the first current;
a second current integrator configured to receive a second current via a second sensing channel and output a second sampling voltage based on the second current; and
a sampling circuit having a plurality of sampling capacitors including a first sampling capacitor, a second sampling capacitor, a third sampling capacitor, and a fourth sampling capacitor,
the first sampling capacitor and the second sampling capacitor connected to an output terminal of the first current integrator and configured to store and hold the first sampling voltage,
the third sampling capacitor and the fourth sampling capacitor connected to an output terminal of the second current integrator and configured to store and hold the second sampling voltage, and
a plurality of switches selectively connecting first ends of the first sampling capacitor, the second sample capacitor, the third sample capacitor, and the fourth sampling capacitor, and
the sampling circuit configured to receive the first and second sampling voltages, to store and hold the first and second sampling voltages, and to remove common noise components included in the first and second sampling voltages.

2. The organic light-emitting diode driving characteristic detection circuit of claim 1 , wherein
the sampling circuit further includes a first sampling switch connected between the output terminal of the first current integrator and the first sampling capacitor, a second sampling switch connected between the output terminal of the first current integrator and the second sampling capacitor, a third sampling switch connected between the output terminal of the second current integrator and the third sampling capacitor, and a fourth sampling switch connected between the output terminal of the second current integrator and the fourth sampling capacitor,
wherein the first sampling switch and the third sampling switch are configured to be turned off in a first period, and
the second sampling switch and the fourth sampling switch are configured to be turned off in a second period, which is different from the first period.

3. The organic light-emitting diode driving characteristic detection circuit of claim 2 , wherein the plurality of switches are turned on after the first sampling switch, the second sampling switch, the third sampling switch, and the fourth sampling switches are turned off.

4. The organic light-emitting diode driving characteristic detection circuit of claim 2 , further comprising:
a differential amplifier configured to receive a first hold voltage and a second hold voltage from the sampling circuit and output an output voltage based on the first hold voltage and the second hold voltage; and
an analog-to-digital converter configured to output a digital sensing signal based on the output voltage.

5. The organic light-emitting diode driving characteristic detection circuit of claim 4 , wherein
the differential amplifier includes a fully differential amplifier (FDA),
the output voltage is a difference between a non-inverted output voltage and an inverted output voltage of the differential amplifier, and
the output voltage is input to the analog-to-digital converter.

6. The organic light-emitting diode driving characteristic detection circuit of claim 5 , wherein
the first sampling capacitor and the fourth sampling capacitor are connected to an inverted input terminal of the differential amplifier, and
the second sampling capacitor and the third sampling capacitor are connected to a non-inverted input terminal of the differential amplifier.

7. The organic light-emitting diode driving characteristic detection circuit of claim 6 , further comprising:
a first hold switch connected between the first sampling capacitor and the inverted input terminal of the differential amplifier;
a second hold switch connected between the second sampling capacitor and the non-inverted input terminal of the differential amplifier;
a third hold switch connected between the third sampling capacitor and the non-inverted input terminal of the differential amplifier; and
a fourth hold switch connected between the fourth sampling capacitor and the non-inverted input terminal of the differential amplifier,
wherein the first hold switch, the second hold switch, the third hold switch, and the fourth hold switch are turned on in the same period.

8. The organic light-emitting diode driving characteristic detection circuit of claim 1 , wherein the sampling circuit further includes a plurality of reference switches which are each connected to the first sampling capacitor to the fourth sampling capacitor and operate to apply a sampling reference voltage to the first sampling capacitor, the second sampling capacitor, the third sampling capacitor, and the fourth sampling capacitor.

9. The organic light-emitting diode driving characteristic detection circuit of claim 1 , wherein each of the first current integrator and the second current integrator includes an amplifier,
the amplifier including a first input terminal, a second input terminal, and an output terminal, an integration capacitor, and an integration switch,
the first input terminal connected to the first sensing channel or the second sensing channel,
the integration capacitor connected between the first input terminal and the output terminal of the amplifier, and
the integration switch connected between both ends of the integration capacitor and configured to reset the integration capacitor,
the second input terminal configured to receive an integrated reference voltage, and
the output terminal configured to output the first sampling voltage or the second sampling voltage.

10. An organic light-emitting diode driving characteristic detection circuit comprising:
a first current integrator configured to receive a first current via a first sensing channel and output a first sampling voltage based on the first current;
a second current integrator configured to receive a second current via a second sensing channel and output a second sampling voltage based on the second current; and
a sampling circuit configured to receive the first and second sampling voltages, to store and hold the first and second sampling voltages, and to remove common noise components included in the first and second sampling voltages,
the sampling circuit including a plurality of sampling capacitors including a first sampling capacitor, a second sampling capacitor, a third sampling capacitor, and a fourth sampling capacitor,
the first sampling capacitor configured to store the first sampling voltage;
a first sampling switch connected between an output terminal of the first current integrator and the first sampling capacitor, the first sampling switch configured to be turned off in a first period to complete the storing of the first sampling voltage in the first sampling capacitor;

the second sampling capacitor configured to store the first sampling voltage;
a second sampling switch connected between the output terminal of the first current integrator and the second sampling capacitor, the second sampling switch configured to be turned off in a second period after the first period to complete the storing of the first sampling voltage in the second sampling capacitor;

the third sampling capacitor configured to store the second sampling voltage;
a third sampling switch connected between the output terminal of the second current integrator and the third sampling capacitor, the third

Assignees

• Samsung Electronics Co Ltd

Inventors

• Lee Ha Jun
• Ahn Jeong Ah
• Jeong Ji-Yong
• Woo Suk-Yun
• Jin Young Sub

Classifications

• G09G2310/0294

  Details of sampling or holding circuits arranged for use in a driver for data electrodes · CPC title

• G09G2300/0408

  Integration of the drivers onto the display substrate · CPC title

• G09G3/3233

  with pixel circuitry controlling the current through the light-emitting element · CPC title

• G09G3/006 Primary

  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 title

• G09G2300/0852

  being a dynamic memory with more than one capacitor · CPC title