Display apparatus and method of driving the same

• US 11,092,839 B2
• Filed: 12/28/2018
• Issued: 08/17/2021
• Est. Priority Date: 01/02/2018
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Choi, Nam-Gon, Lim, Kyoung Ho, Kim, Kangmin, Kim, Jinpil, An, Taehyeong, Hong, Seokha, Kang, Moon Shik, Lee, Jaehoon, Jo, Kunhee, Pyoun, Seoung-Bum
• Primary Examiner(s): Dinh, Duc Q
• Application Number:
  US16/235,443
• Publication Number:
  US 20190204672A1
• Time in Patent Office: 963 Days
• Field of Search: 345102
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 1/133617 Illumination with ultraviolet light; Luminescent elements or materials associated to the cell
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G02F 1/133624 characterised by their spectral emissions
• CPC Class Codes: G02F 1/133626 providing two modes of illumination, e.g. day-night
• CPC Class Codes: G02F 2202/36 Micro- or nanomaterials
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127
• CPC Class Codes: G09G 3/3688 suitable for active matrices only

Abstract

A display apparatus includes a backlight unit including a first light source for outputting a first color light, and a second light source for outputting a second color light that is different from the first color light, a switching element layer on the backlight unit, and including a plurality of switching elements, a liquid crystal layer on the switching element layer, and a color conversion layer on the liquid crystal layer, including a color-converting material for converting a color of light passing therethrough, including a first color area, a second color area, and a third color area, and including quantum dot particles.

Claims

1. A display apparatus comprising:

a backlight unit comprising a first light source for outputting a first color light, and a second light source for outputting a second color light that is different from the first color light;

a switching element layer on the backlight unit, and comprising a plurality of switching elements;

a liquid crystal layer on the switching element layer;

a color conversion layer on the liquid crystal layer, comprising a color-converting material for converting a color of light passing therethrough, comprising a first color area, a second color area, and a third color area, and comprising quantum dot particles; and

a timing controller comprising a dimming control part for analyzing an input image, and for determining a first dimming signal of the first light source and determining a second dimming signal of the second light source,

wherein, as luminance of the input image increases, a turn-on degree of the second light source increases, and

wherein, as chroma of the input image decreases, the turn-on degree of the second light source increases.

2. The display apparatus of claim 1, wherein the first light source is a blue light source for outputting a blue light, and

wherein the second light source is a white light source for outputting a white light.

3. The display apparatus of claim 2, wherein the first color area is a red color area at which the first color light of the first light source and the second color light of the second light source are converted into red light,

wherein the second color area is a green color area at which the first color light and the second color light are converted into green light, and

wherein the third color area is a blue color area for allowing the first color light and the second color light to pass therethrough.

4. The display apparatus of claim 3, wherein the first color area comprises a first quantum dot particle having a first size,

wherein the second color area comprises a second quantum dot particle having a second size that is different from the first size, and

wherein the third color area comprises a scattering particle.

5. The display apparatus of claim 3, further comprising a blue-light-blocking filter in the first color area and in the second color area.

6. The display apparatus of claim 2, wherein the first light source comprises a blue light emitting diode string comprising a plurality of blue light emitting diodes that output the blue light, and

wherein the second light source comprises a white light emitting diode string comprising a plurality of white light emitting diodes that output the white light.

7. The display apparatus of claim 1, further comprising:

a first polarizer between the backlight unit and the switching element layer; and

a second polarizer between the liquid crystal layer and the color conversion layer.

8. The display apparatus of claim 7, further comprising a third polarizer on the color conversion layer, and having a polarizing axis that is different from a polarizing axis of the second polarizer.

9. The display apparatus of claim 7, further comprising an anti-reflection film on the color conversion layer comprising alternately and repeatedly arranged low refractive index and high refractive index layers.

10. The display apparatus of claim 1, wherein the timing controller further comprises a white balance control part for adjusting a white balance of an image to be displayed according to turn-on degree of the first light source and turn-on degree of the second light source.

11. The display apparatus of claim 1, wherein, when the input image represents an achromatic color, and the luminance of the input image is less than a threshold luminance, the first light source is turned off and the second light source is turned on,

wherein, when the input image represents the achromatic color, and the luminance of the input image is equal to, or greater than, the threshold luminance, the first light source is turned on and the second light source is turned on, and

wherein, when the input image represents a chromatic color, the first light source is turned on and the second light source is turned on.

12. The display apparatus of claim 1, wherein the timing controller is configured to determine the first dimming signal of the first light source and the second dimming signal of the second light source according to a input mode signal,

wherein, when the input mode signal represents a color intensive mode, the first light source is turned on and the second light source is turned off,

wherein, when the input mode signal represents a high luminance and wide color volume mode, the first light source is turned on and the second light source is turned on, and

wherein, when the input mode signal represents a low power mode, the first light source is turned off and the second light source is turned on.

13. A method of driving a display apparatus, the method comprising:

outputting a first color light using a first light source;

outputting a second color light using a second light source;

converting the first color light of the first light source and the second color light of the second light source into red at a first color area of a color conversion layer;

converting the first color light of the first light source and the second color light of the second light source into green at a second color area of the color conversion layer;

passing through the first color light of the first light source and the second color light of the second light source at a third color area of the color conversion layer; and

determining a first dimming signal of the first light source and a second dimming signal of the second light source based on an input image,

wherein, as luminance of the input image increases, a turn-on degree of the second light source increases, and

wherein, as chroma of the input image decreases, the turn-on degree of the second light source increases.

14. The method of claim 13, further comprising:

turning on the first light source and maximally turning on the second light source when the luminance of the input image is equal to, or greater than, a threshold luminance, and the input image represents an achromatic color;

turning on the first and second light sources when the luminance of the input image is equal to, or greater than, the threshold luminance, and the input image represents a chromatic color; and

turning on the first light source and turning off the second light source when the luminance of the input image is less than the threshold luminance.

15. The method of claim 13, further comprising:

turning off the first light source and turning on the second light source when the input image represents an achromatic color, and the luminance of the input image is less than a threshold luminance;

turning on the first and second light sources when the input image represents the achromatic color and the luminance of the input image is equal to, or greater than, the threshold luminance; and

turning on the first and second light sources when the input image represents a chromatic color.

16. The method of claim 13, further comprising determining the first dimming signal of the first light source and the second dimming signal of the second light source according to a input mode signal;

turning on the first light source and turning off the second light source when the input mode signal represents a color intensive mode;

turning on the first and second light sources when the input mode signal represents a high luminance and wide color volume mode; and

turning off the first light source and turning on the second light source when the input mode signal represents a low power mode.

17. A display apparatus comprising:

a backlight unit comprising a first light source for outputting a first color light, and a second light source for outputting a second color light that is different from the first color light;

a switching element layer on the backlight unit, and comprising a plurality of switching elements;

a liquid crystal layer on the switching element layer;

a color conversion layer on the liquid crystal layer, comprising a color-converting material for converting a color of light passing therethrough, comprising a first color area, a second color area, and a third color area, and comprising quantum dot particles; and

a timing controller comprising a dimming control part for analyzing an input image, and for determining a first dimming signal of the first light source and determining a second dimming signal of the second light source,

wherein, when luminance of the input image is equal to, or greater than, a threshold luminance, and the input image represents an achromatic color, the first light source is turned on and the second light source is maximally turned on,

wherein, when the luminance of the input image is equal to, or greater than, the threshold luminance, and the input image represents a chromatic color, the first light source is turned on and the second light source is turned on, and

wherein, when the luminance of the input image is less than the threshold luminance, the first light source is turned on and the second light source is turned off.