DISPLAY DEVICE AND METHOD OF TIME DIVISION DRIVING DISPLAY DEVICE

• US 20190331963A1
• Filed: 04/17/2019
• Published: 10/31/2019
• Est. Priority Date: 04/25/2018
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: KIM, Dong-uk, Nam, Minki, Park, Kyoungwon
• Granted Patent: US 11,366,354 B2
• Time in Patent Office: Days
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133602 Direct backlight
• CPC Class Codes: G02F 1/133613 characterized by the sequence of light sources
• CPC Class Codes: G02F 1/133617 Illumination with ultraviolet light; Luminescent elements or materials associated to the cell
• CPC Class Codes: G02F 1/133622 Colour sequential illumination
• CPC Class Codes: G02F 1/1351 Light-absorbing or blocking layers
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources

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.

Claims

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 absorb the second light and convert the second light into first color light and 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 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.

2. The display device of claim 1, wherein the first light and the second 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 wavelength conversion member is configured to convert the first light and the second light into the first color light and the second color light, and the third pixel area is configured to display the first light and the second light.

5. The display device of claim 1, 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, and

wherein the first light source is configured to emit light during the first sub-frame, and the second light source is configured to emit light during the second sub-frame.

6. The display device of claim 5, wherein the third pixel area is configured to block display of the second light during the second sub-frame.

7. The display device of claim 5, wherein the first pixel area and the second pixel area are configured to block display of the first color light and the second color light, respectively, during the first sub-frame.

8. The display device of claim 5, 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, and

wherein the second pixel area is configured to block display of the second color light during the first sub-frame.

9. The display device of claim 5, wherein the first light source and the second light source are configured to emit light during the second sub-frame, and the third pixel area is configured to block display of the first light and the second light during the second sub-frame.

10. The display device of claim 1, wherein the display panel is configured to display an image on a frame-by-frame basis, each frame comprising a first sub-frame, a second sub-frame, and a third sub-frame which are separate time divisions of the frame,

wherein the first light source is configured to emit light during the first sub-frame, and the second light source is configured to emit light during the second sub-frame and the third sub-frame, and

wherein the first pixel area and the second pixel area are configured to block display of the first color light and the second color light during the first sub-frame, the second pixel area and the third pixel area are configured to block display of the second color light and the second light during the second sub-frame, and the first pixel area and the third pixel area are configured to block display of the first color light and the second light during the third sub-frame.

11. 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.

12. The display device of claim 11, 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.

13. 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.

14. A method of time division driving a display device having a first light source, a second light source and a wavelength conversion member configured to receive light from the first and the second light sources to generate a first color light and a second 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 method comprising:

driving the first light source, during a first time period, to generate a first light in the first sub frame;

transmitting the first light, during the first time period, to an outside of the display device to display the first light on the display panel;

driving the second light source, during a second time period after the first time period, to generate a second light in the second sub frame;

transmitting the second light, during the second time period, to the wavelength conversion member to generate the first color light and the second color light on the display panel; and

blocking the second light, during the second sub frame, from being transmitted to the outside of the display device.

15. The method of claim 14, wherein

the transmitting of the first light, during the first time period, to the outside of the display device comprises transmitting the first light through the wavelength conversion member, and

the blocking of the transmitting of the second light, during the second time period, to the outside of the display device comprises blocking the second light from being transmitted to the wavelength conversion member.

16. The method of claim 15, further comprising:

blocking the first light, during the first time period, from generating the first color light and the second color light in the wavelength conversion member.

17. The method of claim 15, further comprising:

transmitting the first light, during the first time period, to the wavelength conversion member to generate the first color light.

18. The method of claim 17, further comprising:

transmitting the first light, during the first time period, to the wavelength conversion member to generate the second color light.

19. The method of claim 17, further comprising:

blocking the first light, during the first time period from generating the second color light in the wavelength conversion member.

20. The method of claim 14, wherein the display device includes a liquid crystal layer and blocking light comprises aligning liquid crystals in the liquid crystal layer to prevent light from being transmitted therethrough.

21. The method of claim 14, wherein each frame further has a third sub frame, and the method further comprising:

driving one of the first and second light source during a third time period to generate a third light in the third sub frame;

transmitting the third light, during the third time period, to the outside of the display device to display the third light on the display panel; and

blocking at least one of the first and second light, during the third sub frame, from being transmitted to the outside of the display device.