DISPLAY METHOD AND APPARATUS

• US 20100207956A1
• Filed: 02/19/2010
• Published: 08/19/2010
• Est. Priority Date: 02/19/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: KEH, Yong-Chan, Kim, Sung-Sun, Lee, Ho-Min, Park, Byeong-Hoon, Lee, Jung-Kee, Kim, Sung-Won
• Granted Patent: US 8,780,143 B2
• Time in Patent Office: Days
• US Class Current: 345/589
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

A method of displaying image data is provided, which includes analyzing histograms by color signals of an input image frame; confirming grayscales by color signals in a predetermined frame unit with reference to the analyzed histograms; determining dimming factors in consideration of maximum grayscale values of the grayscales; determining image gains of the image data by color signals using the determined dimming factors; and outputting an image signal by applying the image gains to the input image and applying the dimming factors to a light source.

Claims

1. A method of displaying image data, comprising the steps of:

analyzing histograms of color signals of an input image frame;

confirming grayscales of the color signals in a predetermined frame unit with reference to the analyzed histograms;

determining dimming factors based on maximum grayscale values of the grayscales;

determining image gains of the image data of the color signals using the determined dimming factors; and

outputting an image signal by applying the image gains and the dimming factors to the input image.

2. The method as claimed in claim 1, wherein the dimming factors are determined by dividing a maximum value in a grayscale range by the maximum grayscale values of the grayscales.

3. The method as claimed in claim 1, wherein the image gains are reciprocal numbers of the respective dimming factors.

4. The method as claimed in claim 1, wherein the image gains are computed based on relations between the brightness of a light source and an output of the image data.

5. The method as claimed in claim 1, wherein the step of confirming the grayscales comprises:

confirming the grayscales of the color signals of the image frame;

determining at least two image frames in a predetermined frame unit;

averaging the grayscales of the image frames included in the unit to confirm the grayscales in the unit; and

confirming the maximum grayscale values of the grayscales in the unit.

6. The method as claimed in claim 1, wherein a light source required for display is provided by a color sequential driving method.

7. A display apparatus, comprising:

a light source unit providing light required to drive a display device;

a light source driving unit providing driving signals to the light source unit;

an image conversion unit converting image data into color signals of a predetermined format;

a display panel controlling grayscales of respective pixels constituting the image data;

a panel driving unit supplying driving signals to the display panel; and

a control unit confirming dimming factors of the color signals of image frames by analyzing histograms of the color signals of the respective image frames, outputting signals for controlling the brightness of the light source to the light source driving unit through reflection of the dimming factors, setting image data gains of the color signals based on the dimming factors, and providing the color signals in which the gains are reflected to the panel driving unit.

8. The display apparatus as claimed in claim 7, wherein the control unit determines the dimming factor values by dividing a maximum value in a grayscale range of the color signals by the maximum grayscale values of the histograms.

9. The display apparatus as claimed in claim 8, wherein the control unit sets reciprocal numbers of the respective dimming factors as the gain values of the image data of the color signals.

10. The display apparatus as claimed in claim 8, wherein the control unit sets the gain values of the image data of the color signals using the dimming factors based on relations between the brightness of the light source of the color signals and the image data of the signals.

11. The display apparatus as claimed in claim 7, wherein the panel driving unit outputs a first Pulse Width Modulation (PWM) signal for controlling a basic brightness of the image data, and the control unit outputs a second PWM signal for controlling a brightness of the plurality of light emitting devices.

12. The display apparatus as claimed in claim 11, wherein the light source driving unit receives the second PWM signal, and modulates the pulse width of current values being supplied to the plurality of light emitting devices.

13. The display apparatus as claimed in claim 7, wherein the light source unit is driven by a color sequential driving method.

14. The display apparatus as claimed in claim 7, wherein the display panel adjusts the grayscales of an output light by controlling an incident angle or projection angle of an incident light.

15. The display apparatus as claimed in claim 7, wherein the control unit comprises:

a histogram analysis unit analyzing the histograms of the color signals of the image frames, and confirming the maximum grayscale values of the grayscales of the respective color signals;

a dimming factor computation unit receiving the maximum grayscale values of the grayscales from the histogram analysis unit, and confirming the dimming factors of the color signals;

a PWM output unit receiving the dimming factors of the color signals from the dimming factor computation unit, generating and providing signals for controlling the brightness of the light source to the light source driving unit;

an image gain computation unit receiving the dimming factors from the dimming factor computation unit, and confirming image gains of the color signals based on relations between the brightness of the light source and the image data of the color signals; and

an image data output unit receiving the image gains of the color signals from the image gain computation unit, reflecting the image gains of the color signals in the image data of the color signals, and outputting the reflected image data to the panel driving unit.