Data compensation circuit and organic light-emitting diode display having the same

Patent metadata

Field	Value
Publication number	US-9715849-B2
Application number	US-201514626131-A
Country	US
Kind code	B2
Filing date	Feb 19, 2015
Priority date	Oct 22, 2014
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

A data compensation circuit and OLED display including the same are disclosed. In one aspect, the circuit compensates a voltage drop of a power voltage applied to a display panel of the display. The circuit includes an average current calculator configured to calculate an average current value of each of M×N pixel blocks. The circuit also includes a voltage drop calculator configured to calculate one or more pixel block voltage drops of the power voltage of each of the selected target pixel blocks based at least in part on an X-axis voltage drop and a Y-axis voltage drop of each of target pixel block. The circuit further includes an interpolator configured to interpolate the pixel block voltage drops of adjacent target pixel blocks so as to calculate a pixel voltage drop of a target pixel selected among one of the target pixel blocks.

First claim

What is claimed is:

1. A data compensation circuit for compensating a voltage drop of a power voltage applied to a display panel of an organic light-emitting diode (OLED) display, the circuit comprising:
an average current calculator configured to calculate an average current value of each of M×N pixel blocks, where M and N are positive integers, based at least in part on input image data, wherein each of the M×N pixel blocks includes a plurality of pixels, and wherein a plurality of target pixel blocks are selected among the pixel blocks;
a voltage drop calculator configured to calculate one or more pixel block voltage drops of the power voltage of each of the selected target pixel blocks based at least in part on an X-axis voltage drop and a Y-axis voltage drop of each of the target pixel blocks, wherein voltage drop calculator is further configured to calculate the X-axis and Y-axis voltage drops based at least in part on the product of a Y-axis voltage drop weighted value and an X-axis voltage drop distribution coefficient;
an interpolator configured to interpolate the pixel block voltage drops of adjacent target pixel blocks so as to calculate a pixel voltage drop of a target pixel selected among one of the target pixel blocks; and
a compensated data generator configured to compensate a data voltage of the input image data based at least in part on the pixel voltage drop so as generate a compensated data voltage.

2. The circuit of claim 1 , wherein the product corresponds to an amount of current flowing into each of the target pixel blocks when a unit current is applied to a selected reference pixel block of the pixel blocks.

3. The circuit of claim 1 , wherein the Y-axis voltage drop weighted value includes a weighted value of the Y-axis voltage drop of each of the target pixel blocks when a unit current is applied to a selected reference pixel block of the pixel blocks.

4. The circuit of claim 3 , wherein the voltage drop calculator is further configured to set the Y-axis voltage drop weighted value to have a Y-coordinate value of the reference pixel block when the Y-coordinate value of the reference pixel block is less than a Y-coordinate value of each of the target pixel blocks, and
wherein the voltage drop calculator is further configured to set the Y-axis voltage drop weighted value to have the Y-coordinate value of each of the target pixel blocks when the Y-coordinate value of the reference pixel block is greater than or equal to the Y-coordinate value of each of the target pixel blocks.

5. The circuit of claim 3 , wherein the X-axis voltage drop distribution coefficient is represented as Smn(x, y), and
wherein the Smn(x, y) is a normalized value of the X-axis voltage drop of each of the target pixel blocks located at a coordinate (x, y) when the unit current is applied to the reference pixel block located at a coordinate (m, n), where x and m are positive integers less than or equal to M, and where y and n are a positive integer less than or equal to N.

6. The circuit of claim 5 , wherein a first X-axis voltage drop distribution coefficient is substantially equal to a second X-axis voltage drop distribution coefficient,
wherein the first X-axis voltage drop distribution coefficient includes the X-axis voltage drop distribution coefficient of each of the target pixel blocks located at a second X-coordinate when the unit current is applied to the reference pixel block located at a first X-coordinate, and
wherein the second X-axis voltage drop distribution coefficient includes the X-axis voltage drop distribution coefficient of each of the target pixel blocks located at the first X-coordinate when the unit current is applied to the reference pixel block located at the second X-coordinate.

7. The circuit of claim 5 , wherein a first X-axis voltage drop distribution coefficient is substantially equal to a second X-axis voltage drop distribution coefficient,
wherein the first X-axis voltage drop distribution coefficient is the X-axis voltage drop distribution coefficient of each of the target pixel blocks located at a second Y-coordinate when the unit current is applied to the reference pixel block located at a first Y-coordinate, and
wherein the second X-axis voltage drop distribution coefficient is the X-axis voltage drop distribution coefficient of each of the target pixel blocks located at the first Y-coordinate when the unit current is applied to the reference pixel block located at the second Y-coordinate.

8. The circuit of claim 1 , wherein the voltage drop calculator is further configured to calculate the pixel block voltage drop of each of the target pixel blocks based on the following Equation:

Vdrop
⁡

(

x
,
y

)

=

Rs
×

∑

m
=
1

M

⁢

⁢

∑

n
=
1

N

⁢

⁢

Imn
×

Smn
⁡

(

x
,
y

)

×
Yn

,

where Rs denotes a resistance coefficient, Imn denotes the average current value of a reference pixel block corresponding to a coordinate (m, n) selected among the pixel blocks, Smn(x, y) denotes the X-axis voltage drop distribution coefficient corresponding to a coordinate (x, y) selected among the target pixel blocks when a unit current flows through the reference pixel block, Yn denotes the Y-axis voltage drop weighted value, M denotes the total number of the pixel blocks in the X-axis direction, and N denotes the total number of the pixel blocks in the Y-axis direction.

9. The circuit of claim 8 , wherein the voltage drop calculator includes:
a first multiplier configured to multiply the average current value of the reference pixel block corresponding to the coordinate (m, n) and the X-axis voltage drop distribution coefficient corresponding to the coordinate (x, y) so as to output a first result;
a second multiplier configured to multiply the first result corresponding to the coordinate (m, n) and the Y-axis voltage drop weighted value corresponding to the coordinate (m, n) so as to output a second result; and
an adder configured to sum a plurality of second r

Assignees

• Samsung Display Co Ltd

Inventors

• Fujii Mitsuru

Classifications

• G09G2320/0285

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