Display device and method of time division driving display device

Patent metadata

Field	Value
Publication number	US-11366354-B2
Application number	US-201916387475-A
Country	US
Kind code	B2
Filing date	Apr 17, 2019
Priority date	Apr 25, 2018
Publication date	Jun 21, 2022
Grant date	Jun 21, 2022

Abstract

A display device includes: a light source unit having: a first light source to emit first light having a first peak wavelength; and a second light source to emit second light having a second peak wavelength, the second peak wavelength being shorter than the first peak wavelength; a wavelength conversion member to absorb the second light and convert the second light into first color light and second color light, each of the first and second color light having peak wavelengths different from the first and second peak wavelengths; and a display panel having a first pixel area to display the first color light, a second pixel area to display the second color light, and a third pixel area to display the first light, wherein the first peak wavelength and the second peak wavelength have a value of about 365 nm or more to about 500 nm or less.

First claim

What is claimed is:

1. A display device comprising:
a light source unit having:
a first light source to emit a first light having a first peak wavelength; and
a second light source to emit a second light having a second peak wavelength,

the second peak wavelength being shorter than the first peak wavelength;
a wavelength conversion member to perform a wavelength conversion on at least one of the first light and the second light by absorbing the at least one of the first light and the second light into a first color light and a second color light, each of the first color light and the second color light having peak wavelengths different from the first peak wavelength and the second peak wavelength; and
a display panel having a first pixel area to display the first color light, a second pixel area to display the second color light, and a third pixel area to display a third color light,
wherein the display panel is configured to display an image on a frame-by-frame basis, each frame comprising a first sub-frame and a second sub-frame which are separate time divisions of the frame,
wherein the first peak wavelength and the second peak wavelength have a value of about 365 nm or more to about 500 nm or less, wherein:
the first light having the first peak wavelength, the second light having the second peak wavelength, and the third color light are of a substantially same color light,
during the first sub-frame, the first pixel area and the second pixel area are configured to emit the first color light and the second color light, respectively, by converting the first light generated by the first light source, and the third pixel area is configured to emit the third color light by transmitting the first light generated by the first light source, and
during the second sub-frame, the first pixel area and the second pixel area are configured to emit the first color light and the second color light, respectively, by converting the first light generated by the first light source and the second light generated by the second light source, and the third pixel area does not emit any light by blocking the first light generated by the first light source and the second light generated by the second light source.

2. The display device of claim 1 , wherein the first light, the second light, and the third color light are blue light.

3. The display device of claim 1 , wherein the first peak wavelength is in a range of about 450 nm or more to about 500 nm or less, and the second peak wavelength is in a range of about 365 nm or more to less than the first peak wavelength.

4. The display device of claim 1 ,
wherein the first light source is configured to emit the first light during the first sub-frame, and the first light source and the second light source are configured to emit the first light and the second light, respectively, during the second sub-frame.

5. The display device of claim 4 , wherein the first color light and the second color light have a longer wavelength than the first light,
wherein the first color light has a longer wavelength than the second color light.

6. The display device of claim 1 , wherein the wavelength conversion member comprises a first wavelength conversion portion and a second wavelength conversion portion,
wherein the first wavelength conversion portion comprises a first light-emitting material and the second wavelength conversion portion comprises a second light-emitting material,
wherein the first wavelength conversion portion is configured to convert at least one of the first light and the second light into the first color light, the second wavelength conversion portion is configured to convert at least one of the first light and the second light into the second color light, and
wherein the first pixel area overlaps the first wavelength conversion portion, and the second pixel area overlaps the second wavelength conversion portion.

7. The display device of claim 6 , wherein the wavelength conversion member further comprises a light-transmitting portion that transmits the first light, and the third pixel area overlaps the light-transmitting portion.

8. The display device of claim 1 , wherein the wavelength conversion member is disposed under the display panel, and the wavelength conversion member is configured to provide the first light, the second light, the first color light, and the second color light to the display panel.

9. A method of time division driving a display device having a first light source configured to emit a first blue light, a second light source configured to emit a second blue light, and a wavelength conversion member comprising a light-emitting material and configured to receive light from the first and the second light sources to generate a red color light and a green color light to display an image on a display panel on a frame-by-frame basis, with each frame having first and second sub frames, the display panel having a first pixel area to display the red color light, a second pixel area to display the green color light, and a third pixel area to display a blue color light, the method comprising:
driving the first light source to generate the first blue light in the first sub frame;
transmitting the first blue light in the first pixel area, the second pixel area, and the third pixel area such that the first pixel area and the second pixel area are configured to emit the red color light and the green color light by converting the first blue light, and the third pixel area is configured to emit the blue color light, respectively, by transmitting the first blue light during the first sub frame;
driving the first light source and the second light source to generate the first blue light and the second blue light in the second sub frame;
transmitting the first blue light and the second blue light to the wavelength conversion member in the first pixel area and the second pixel area such that the first pixel area and the second pixel area are configured to emit the red color light and the green color light, respectively, by converting the first blue light and the second blue light during the second sub frame;
blocking the first blue light and the second blue light in the third pixel area such that the third pixel area does not emit any light during the second sub frame, and
increasing a light absorption rate of the light-emitting material by the second blue light.

10. The method of claim 9 , wherein
the transmitting of the first blue light during the first sub frame comprises transmitting the first blue light through the wavelength conversion member, and
the blocking the first blue light and the second blue light in the third pixel area during the second sub frame comprises blocking the second blue light from being transmitted to the wavelength conversion member.

11. The method of claim 10 , further comprising:
blocking the first blue light from generating the red color light and the green color light in the wavelength conversion member in another operating mode.

12. The method of claim 9 , further comprising:
blocking the first blue light from generating the green color light in the wavelength conversion member in another operating mode.

13. The method of claim 9 , wherein the display device further includes a liquid crystal layer configured to adjust transmission amounts of the first blue light provided from the first light source and the second blue light provided from the second light source, and
wherein the wavelength conversion member is configured to receive light from the liquid crystal layer.

14. The method of claim 9 , wherein each frame further has a third sub frame,

Assignees

• Samsung Display Co Ltd

Inventors

• Kim Dong-Uk
• Nam Minki
• Park Kyoungwon

Classifications

• G02F1/133617 Primary

  Illumination with ultraviolet light; Luminescent elements or materials associated to the cell · CPC title

• G02F1/133514

  Colour filters · CPC title

• G02F1/1336

  Illuminating devices · CPC title

• G02F1/133613

  characterized by the sequence of light sources · CPC title

• G02F1/133614

  using photoluminescence, e.g. phosphors illuminated by UV or blue light · CPC title