Light emitting device voltage setting method determining whether a black floating phenomenon has been observed

1 . A voltage setting method of an electronic device, in which a plurality of sub-pixels are disposed in a display device, and an anode initialization voltage being applied to the plurality of sub-pixels is set to a plurality of voltage levels, the voltage setting method comprising:

setting a data voltage for displaying an image having a black grayscale to a first level to the plurality of sub-pixels;

applying the anode initialization voltage to the plurality of sub-pixels having a first level;

determining whether a black floating phenomenon has been observed in the displayed image;

decreasing the anode initialization voltage applied to the plurality of sub-pixels by a second level based on the black floating phenomenon being observed to generate a set anode initialization voltage;

applying the set anode initialization voltage to the plurality of sub-pixels; and

writing a level of the set anode initialization voltage to the plurality of sub-pixels based on a determination that the black floating phenomenon has not been observed.

2 . The voltage setting method of claim 1 , wherein when the set anode initialization voltage is applied, determining that the black floating phenomenon has been observed.

3 . The voltage setting method of claim 1 , further comprising determining whether the anode initialization voltage has exceeded a predetermined minimum value.

4 . The voltage setting method of claim 3 , wherein the determining of whether the anode initialization voltage has exceeded the predetermined minimum value is performed after the decreasing of the anode initialization voltage by the second level.

5 . The voltage setting method of claim 3 , wherein the applying of the set anode initialization voltage is performed based on a determination that the anode initialization voltage has exceeded the predetermined minimum value.

6 . The voltage setting method of claim 5 , further comprising setting the anode initialization voltage to a third level based on a determination that the anode initialization voltage has not exceeded the predetermined minimum value.

7 . The voltage setting method of claim 6 , further comprising:

applying the anode initialization voltage having the third level; and

determining whether the black floating phenomenon has been observed as the anode initialization voltage having the third level is applied.

8 . The voltage setting method of claim 7 , further comprising:

based on the black floating phenomenon being observed as the anode initialization voltage having the third level is applied,

increasing a level of the data voltage for displaying the image having the black grayscale by a second level; and

determining whether the black floating phenomenon has been observed as the data voltage increased by the second level is applied.

9 . The voltage setting method of claim 8 , wherein, based on the determination that the black floating phenomenon has been observed as the data voltage increased by the second level is applied, the level of the data voltage for displaying the image having the black grayscale is increased by the second level.

10 . The voltage setting method of claim 8 , further comprising writing the level of a set data voltage for displaying the image having the black grayscale to the display device based on a determination that the black floating phenomenon has not been observed as the data voltage increased by the second level is applied.

11 . The voltage setting method of claim 10 , wherein, in the writing of the level of the set data voltage for displaying the image having the black grayscale to the display device, the level of the anode initialization voltage is written as the third level to the display device.

12 . The voltage setting method of claim 7 , further comprising:

based on the black floating phenomenon not being observed as the anode initialization voltage having the third level is applied,

decreasing the level of the data voltage for displaying the image having the black grayscale by a third level; and

determining whether the black floating phenomenon has been observed as the data voltage decreased by the third level is applied.

13 . The voltage setting method of claim 12 , wherein, based on the determination that the black floating phenomenon has not been observed as the data voltage decreased by the third level is applied, the level of the data voltage for displaying the image having the black grayscale is decreased by the third level.

14 . The voltage setting method of claim 12 , comprising:

increasing the level of the data voltage for displaying the image having the black grayscale by the third level based on a determination that the black floating phenomenon has not been observed as the data voltage increased by the third level is applied; and

writing the level of the data voltage for displaying the image having the black grayscale to the display device.

15 . The voltage setting method of claim 14 , wherein, in the writing the level of the data voltage for displaying the image having the black grayscale to the display device, the level of the anode initialization voltage is written as the third level to the display device.

16 . The voltage setting method of claim 1 , wherein at least one of the plurality of sub-pixels includes:

a sub-pixel circuit configured to generate a driving current; and

a light emitting element connected to the sub-pixel circuit, the light emitting element having the driving current flowing therethrough, and

wherein the sub-pixel circuit includes an initialization transistor configured to switch an electrical connection between the light emitting element and a power line to which the anode initialization voltage is applied.

17 . The voltage setting method of claim 16 , wherein the power line to which the anode initialization voltage is applied is a fourth power line,

wherein the light emitting element includes:

a first electrode connected to the initialization transistor;

a second electrode connected to a second power line to which a second power voltage is applied; and

a light emitting layer located between the first electrode and the second electrode, and

wherein a voltage difference between the first level and the second power voltage is lower than a threshold voltage of the light emitting element.

18 . The voltage setting method of claim 16 , wherein the display device further includes:

a display panel having the plurality of sub-pixels located therein;

a power supply circuit configured to supply the anode initialization voltage to the display panel; and

a timing controller configured to control the power supply circuit, and

wherein, in the writing of the level of the set anode initialization voltage to the display device, the level of the anode initialization voltage is written to a memory of the timing controller.

19 . The voltage setting method of claim 18 , wherein the level of the data voltage for displaying the image having the black grayscale is further stored in the memory of the timing controller.

20 . An electronic device comprising:

a display panel having a plurality of sub-pixels therein, the display panel, wherein an anode initialization voltage is applied to the plurality of sub-pixels;

a data driving circuit configured to supply a data voltage to the plurality of sub-pixels;

a power supply circuit configured to supply the anode initialization voltage to the plurality of sub-pixels; and

a timing controller configured to control the data driving circuit with reference to a memory, and to control the anode initialization voltage outputted from the power supply circuit to have a predetermined level,

wherein the predetermined level is set by:

setting the data voltage for displaying an image having a black grayscale to a first level to the plurality of sub-pixels;

applying the anode initialization voltage having a first level to the plurality of sub-pixels;

determining whether a black floating phenomenon in a displayed image has been observed;

decreasing the anode initialization voltage applied to the plurality of sub-pixels by a first level based on a determination that the black floating phenomenon has been observed to generate a set anode initialization voltage;

applying the set anode initialization voltage to the plurality of sub-pixels; and

writing a level of the set anode initialization voltage to the plurality of sub-pixels based on a determination that the black floating phenomenon has not been observed.