Display apparatus

• US 20050225681A1
• Filed: 03/22/2005
• Published: 10/13/2005
• Est. Priority Date: 04/09/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Sohn, Young-wook
• Granted Patent: US 7,345,712 B2
• Time in Patent Office: Days
• US Class Current: 348/607
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/0266 Reduction of sub-frame artefacts
• CPC Class Codes: G09G 2320/103 Detection of image changes, e.g. determination of an index representative of the image change
• CPC Class Codes: G09G 2340/16 Determination of a pixel data signal depending on the signal applied in the previous frame
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/28 using luminous gas-discharge panels, e.g. plasma panels
• CPC Class Codes: G09G 3/34 by control of light from an independent source
• CPC Class Codes: Y10S 348/91 Flicker reduction

Abstract

A display apparatus to receive a picture signal containing information of a picture and to process the picture signal using at least an area distinguishing the picture from another picture includes a motion detector to detect whether there is a motion in the area of the picture signal, a hysteresis generator to output hysteresis information on each area according to a detected result of the motion detector from a previous frame up to a current frame, a moving picture detector to detect whether the picture signal is a moving picture signal or a still picture signal in the area on the basis of the hysteresis information, and a gradation level converter to convert the picture signal corresponding to the area into either a group of gradation levels for a moving picture to display the moving picture signal or a group of gradation levels for a still picture to display the still picture signal according to a detecting result of the moving picture detector. With this configuration, a false contour of a moving picture signal can be attenuated, thereby minimizing a flicker.

Claims

1. A display apparatus to receive a picture signal containing information of a picture and to process the picture signal by at least an area making up the picture, comprising:

a motion detector to detect whether there is a motion in an area of a picture signal;

a hysteresis generator to output hysteresis information on each area according to a detected result of the motion detector from at least one of previous frames and a current frame;

a moving picture detector to detect whether the picture signal is a moving picture signal or a still picture signal in the area on the basis of the hysteresis information; and

a gradation level converter to convert the picture signal corresponding to the area into either a group of gradation levels for a moving picture to display the moving picture signal or a group of gradation levels for a still picture to display the still picture signal according to a detected result of the moving picture detector.

2. The display apparatus according to claim 1, wherein the hysteresis generator outputs the hysteresis information by adding and subtracting a weight according to the detected result of the motion detector to and from a predetermined hysteresis parameter, and the moving picture detector detects whether the picture signal corresponding to the area is the moving picture signal or the still picture signal based on a value of the hysteresis parameter.

3. The display apparatus according to claim 2, wherein the moving picture detector detects the picture signal corresponding to the area as the moving picture signal when the value of the hysteresis parameter reaches a first reference range of the moving picture, detects the picture signal corresponding to the area as the still picture signal when the value of the hysteresis parameter reaches a second predetermined reference range of the still picture, and outputs to maintain the detecting result of the previous frame when the value of the hysteresis parameter is between the first reference range of the moving picture and the second reference range of the still picture.

4. The display apparatus according to claim 2, wherein the hysteresis parameter varies within a limited range.

5. The display apparatus according to claim 3, wherein the hysteresis parameter varies within a limited range.

6. The display apparatus according to claim 1, wherein the moving picture detector detects the picture signal corresponding to the area as the moving picture signal when a motion in the area is repeatedly detected in at least two consecutive frames by the motion detector.

7. The display apparatus according to claim 1, further comprising:

a film mode detector to detect whether each frame of the picture signal is inputted as a film mode in which the frame is repeatedly inputted for predetermined number of times,

wherein the moving picture detector changes a detecting reference to determine the moving picture signal or the still picture signal, based on the hysteresis information and a detected result of the film mode detector.

8. The display apparatus according to claim 1, wherein the motion detector detects whether an image of the area is in motion by detecting a predetermined number of sample pixels in the area, and the hysteresis generator outputs the hysteresis information on the area containing the sample pixels from the previous frame up to the current frame based on the detected results of the motion detector from the sample pixels of each area.

9. The display apparatus according to claim 2, wherein the motion detector detects whether an image of the area is in motion by detecting a predetermined number of sample pixels in the area, and the hysteresis generator outputs the hysteresis information on the area containing the sample pixels from the previous frame up to the current frame based on the detected results of the motion detector from the sample pixels of each area.