Method of driving a light source, light source apparatus for performing the method and display apparatus having the light source apparatus

• US 8,730,148 B2
• Filed: 05/14/2009
• Issued: 05/20/2014
• Est. Priority Date: 11/19/2008
• Status: Expired due to Fees

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Park, Young-Min, Kim, Gi-Cherl, Park, Se-Ki, Song, Si-Joon, Lee, Young-Keun, Kwon, Yong-Hoon
• Primary Examiner(s): Yang, Kwang-Su
• Application Number:
  US12/465,802
• Publication Number:
  US 20100123401A1
• Time in Patent Office: 1,832 Days
• Field of Search: 345/102
• US Class Current: 345/102
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/2014 by modulation of the duration of a single pulse during which the logic level remains constant
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/22 using optical feedback

Abstract

A method of driving a light source of a light source module including a red light source, a green light source and a blue light source, includes sensing a luminous intensity of the environment; and adjusting a wavelength of light generated from the light source module according to the luminous intensity of the environment.

Claims

1. A method of driving a light source of a light source module that includes a plurality of light-emitting blocks, each light-emitting block including a red light source, a green light source and a blue light source, the method comprising:

sensing a luminous intensity of an environment;

adjusting a wavelength of light generated from the light source module according to the luminous intensity of the environment; and

individually controlling a luminance of the light-emitting blocks according to a gray-scale of a plurality of image blocks corresponding to the light-emitting blocks using the light adjusted by the wavelength,

wherein adjusting the wavelength of the light includes;

increasing the wavelength of the light when the luminous intensity is less than a low reference value; and

decreasing the wavelength of the light when the luminous intensity is greater than a high reference value,

wherein increasing the wavelength of the light includes;

increasing a peak current of a red driving signal driving the red light source; and

decreasing a duty ratio of the red driving signal.

2. The method of claim 1, wherein decreasing the wavelength of the light includes:

increasing a peak current of a green driving signal driving the green light source; and

decreasing a duty ratio of the green driving signal.

3. The method of claim 1, wherein adjusting the wavelength of the light includes:

adjusting the wavelength of the light when the luminous intensity is between the low reference value and the high reference value.

4. The method of claim 3, wherein adjusting the wavelength of the light includes:

adjusting peak currents of red and green driving signals driving the red and green light sources; and

adjusting duty ratios of the red and green driving signals.

5. A light source apparatus comprising:

a light source module that includes a plurality of light-emitting blocks, each light-emitting block including a red light source, a green light source and a blue light source;

a light source module driving part adapted to adjust a wavelength of light generated from the light source module according to a luminous intensity of an environment by individually controlling a luminance of the light-emitting blocks according to a gray-scale of a plurality of image blocks corresponding to the light-emitting blocks using the light adjusted by the wavelength,

wherein the light source module driving part includes;

a luminous intensity sensing part sensing the luminous intensity of the environment to generate an intensity signal;

a current control part adjusting a peak current of a driving signal driving the plurality of light-emitting blocks based on the intensity signal; and

a local dimming control part adjusting a duty ratio of the driving signal based on the intensity signal, and

wherein the local dimming control part includes;

a reference duty ratio determining part that determines reference duty ratios of the red, green and blue driving signals by using the intensity signal, and

wherein the current control part increases the peak current of the red driving signal driving the red light source and the reference duty ratio determining part decreases the duty ratio of the red driving signal,

when the intensity signal is less than a low reference value.

6. The light source apparatus of claim 5, wherein the light source module driving part increases the wavelength of the light when the luminous intensity is less than the low reference value, and decreases the wavelength of the light when the luminous intensity is greater than a high reference value.

7. The light source apparatus of claim 5, wherein the light source module driving part adjusts the wavelength of the light when the luminous intensity is between the low reference value and a high reference value.

8. The light source apparatus of claim 5, wherein the light source module driving part includes:

a driving part generating the driving signal by using the adjusted peak current and the adjusted duty ratio.

9. The light source apparatus of claim 8, wherein the local dimming control part includes:

a representative data determining part that divides an image signal into the plurality of image blocks corresponding to the light-emitting blocks and determines red, green and blue representative gray-scales by using red, green and blue gray-scales included each of the image blocks, and

a duty ratio determining part that determines duty ratios of the red, green and blue driving signals by using the red, green and blue representative gray-scales based on the reference duty ratios.

10. The light source apparatus of claim 9, wherein the current control part increases the peak current of the green driving signal driving the green light source and the reference duty ratio determining part decreases the duty ratio of the green driving signal, when the intensity signal is greater than a high reference value.

11. The light source apparatus of claim 10, wherein the current control part changes the peak currents of the red and green driving signals driving the red and green light sources and the reference duty ratio determining part changes the duty ratios of the red and green driving signals, when the intensity signal is between the low reference value and the high reference value.

12. The light source apparatus of claim 11, wherein the current control part includes a look up table that stores the peak currents of the red, green and blue driving signals corresponding to the intensity signal.

13. A display apparatus comprising:

a display panel displaying an image;

a light source module that includes a plurality of light-emitting blocks, each light-emitting block including a red light source, a green light source and a blue light source, and providing the display panel with light; and

a light source module driving part adapted to adjust a wavelength of the light generated from the light source module according to a luminous intensity of an environment by individually controlling a luminance of the light-emitting blocks according to a gray-scale of a plurality of image blocks corresponding to the light-emitting blocks using the light adjusted by the wavelength,

wherein the light source module driving part increases a peak current of a red driving signal driving the red light source when the intensity signal is less than a low reference value, to increase the wavelength of the light.

14. The display apparatus of claim 13, wherein the light source module driving part increases a peak current of a green driving signal driving the green light source when the intensity signal is greater than a high reference value, to decrease the wavelength of the light.

15. The display apparatus of claim 14, wherein the light source module driving part changes the peak currents of the red and green driving signals driving the red and green light sources when the intensity signal is between the low reference value and the high reference value, to adjust the wavelength of the light.