Monitor

• US 7,173,638 B2
• Filed: 05/30/2002
• Issued: 02/06/2007
• Est. Priority Date: 05/30/2001
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Jeong, Dong-Won
• Primary Examiner(s): Awad; Amr A.
• Assistant Examiner(s): SHENG, TOM V
• Application Number:
  US10/473,343
• Publication Number:
  US 20040113924A1
• Time in Patent Office: 1,713 Days
• Field of Search: 345/63, 345/88, 345/89, 345/690, 348/254, 348/674
• US Class Current: 345/690
• 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 2370/047 using display data channel standard [DDC] communication
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/04 using circuits for interfacing with colour displays
• CPC Class Codes: H04N 9/73 Colour balance circuits, e.g. white balance circuits or colour temperature control camera processing pipelines for colour balance H04N23/88

Abstract

A monitor is disclosed, in which R/G/B signals provided from a video source are compensated to adapt to the color reproduction of the monitor, thereby obtaining the best picture quality. The monitor includes a video source for outputting one video signal, a color compensator for detecting characteristics of the video signal output from the video source and for comparing the detected characteristics with display characteristics of the monitor to compensate the color of the video signal, a video processor for processing the video signal output from the color compensator, and a display for displaying the video signal output from the video processor.

Claims

1. A monitor comprising:

a video source outputting a first video signal;

a color correction unit detecting a characteristic of the first video signal outputted from the video source, comparing the detected characteristic of the first video signal to a display characteristic of the monitor to generate a difference value, and overlapping a second video signal from the source with the difference value to generate a color-corrected video signal;

a video processing unit carrying out a video processing on the color-corrected video signal outputted from the color correction unit; and

a display unit displaying the color-corrected video signal outputted from the video processing unit.

2. The monitor of claim 1, wherein the display unit is selected from a group consisting of CRT (cathode ray tube), LCD (liquid crystal display), and PDP (plasma display panel).

3. The monitor of claim 1, wherein the first video signal detected by the color correction unit is a signal video-processed through the video processing unit.

4. The monitor of claim 1, wherein the color correction unit:

detects voltages of the first video signal in a full white mode and in a partial white mode;

generates a voltage ratio based on the detected voltages in the full white mode and partial white mode; and

detects the characteristic of the first video signal based on the voltage ratio.

5. The monitor of claim 4, wherein the characteristic of the video signal and the display characteristic of the monitor are white gamma values.

6. The monitor, of claim 5, wherein the color correction unit generates the difference value based on a difference between the white gamma value of the video signal and the white gamma value of the monitor.

7. The monitor of claim 1, wherein the characteristic of the first video signal detected by the color correction unit includes at least one selected from a group consisting of R/G/B brightness, current, and voltage data.

8. The monitor of claim 1, wherein the display characteristic information of the monitor is included in EDID (extended display identification data).

9. The monitor of claim 1, wherein the first video signal is a reference signal and the second video signal is an RGB signal.

10. The monitor of claim 1, wherein the first and second video signals are RGB signals.

11. A monitor, comprising:

a video source outputting a first video signal;

a color correction unit detecting a characteristic of the first video signal output from the video source and correcting a color of the second video signal by comparing the detected characteristic of the first video signal to a display characteristic of the monitor;

a video processing unit carrying out a video processing on the color-corrected video signal outputted from the color correction unit; and

a display unit displaying the color-corrected video signal output from the video processing unit, the color correction unit comprising;

an A/D conversion unit converting the first video signal, corresponding to an analog reference video signal for color correction to be video-processed through the video processing unit, into a digital reference video signal;

a memory unit storing the display characteristics information of the monitor and the digital reference video signal outputted from the A/D conversion unit;

an R/G/B voltage ratio operation unit calculating an R/G/B voltage ratio of the digital reference video signal outputted from the A/D conversion unit;

an R/G/B white gamma operation unit calculating an R/G/B white gamma value of the reference video signal using the R/G/B voltage ratio calculated by the R/G/B voltage ratio operation unit and the monitor display characteristic information stored in a memory unit;

a gamma difference operation unit calculating a difference between the R/G/B white gamma value of the reference video signal outputted from the R/G/B white gamma operation unit and the R/G/B white gamma value included in the monitor characteristic information stored in the memory unit;

a D/A conversion unit converting an output of the gamma difference operation unit into analog; and

an adder unit overlapping the gamma difference value outputted from the D/A conversion unit with the second video signal outputted from the video source for color correction so as to output the overlapped result to the video processing unit.

12. The monitor of claim 11, wherein the first video signal is a reference signal and the second video signal is an RGB signal.

13. The monitor of claim 11, wherein the first and second video signals are RGB signals.

14. A monitor comprising:

a video source outputting a first video signal;

a microcomputer requesting the video source to transmit the first video signal for color correction in accordance with a user'"'"'s color correction request;

a color correction unit detecting a characteristic of the first video signal outputted from the video source, the color correction unit comparing the detected characteristic of the first video signal to a display characteristic of the monitor so as to calculate a color correction value in accordance with a characteristic difference between the detected and display characteristics, and the color correction unit correcting a color of a second video signal by adding the color correction value to the second video signal from the video source;

a video processing unit carrying out a video processing on the color-corrected video signal outputted from the color correction unit; and

a display unit displaying the video signal outputted from the video processing unit.

15. A monitor comprising:

a microcomputer requesting a video source to transmit a reference video signal for color correction in accordance with a selection of a display mode for user'"'"'s color correction, so as to output a control signal to perform a video processing of the reference video signal outputted from the video source or an RGB video signal outputted from the video source;

a video processing unit carrying out the video processing on the RGB or reference video signal outputted from the video source in accordance with the control signal outputted from the microcomputer;

a display unit displaying an output of the video processing unit on a screen; and

a color correction unit detecting a characteristic information of the reference video signal video-processed through the video processing unit, the color correction unit comparing the detected characteristic information to a display characteristic information of the monitor so as to calculate a compensation value in accordance with a display characteristic difference from the video source, and the color correction unit overlapping the compensation value with the RGB video signal outputted from the video source so as to output the overlapped value to the video processing unit.

16. The monitor of claim 15, wherein the display characteristic information of the monitor is included in EDID (extended display identification data) and the characteristic information of the reference video signal includes R/G/B brightness, current, and voltage data.

17. The monitor of claim 15, wherein the reference video signal detected by the color correction unit includes a full white signal and a partial white signal.

18. The monitor of claim 15, the color correction unit comprising:

an A/D conversion unit converting an analog reference video signal for color correction to be video-processed through the video processing unit into a digital reference video signal;

a memory unit storing the display characteristic information of the monitor and the digital reference video signal outputted from the A/D conversion unit;

an R/G/B voltage ratio operation unit calculating an R/G/B voltage ratio of the digital reference video signal outputted from the A/D conversion unit;

an R/G/B white gamma operation unit calculating an R/G/B white gamma value of the reference video signal using the R/G/B voltage ratio calculated by the R/G/B voltage ratio operation unit and the monitor display characteristic information stored in the memory unit;

a gamma difference operation unit calculating a difference between the R/G/B white gamma value of the reference video signal outputted from the R/G/B white gamma operation unit and the R/G/B white gamma value included in the monitor characteristic information stored in the memory unit;

a D/A conversion unit converting an output of the gamma difference operation unit into analog; and

an adder unit overlapping the gamma difference value outputted from the D/A conversion unit with the RGB video signal outputted from the video source for color correction so as to output the overlapped result to the video processing unit.

19. A color correction circuit, comprising:

a calculation circuit to calculate a ratio of voltages of a reference signal in different video modes;

wherein the different video modes includes a full white mode,

a detector to detect a parameter of a reference signal based on the voltage ratio;

a comparator to compare the detected parameter of the reference signal to a display parameter of a monitor to generate a difference value; and

an adder to add the difference value to a video signal received from a video source to generate a color-corrected video signal for display on the monitor.

20. The circuit of claim 19, wherein the detected parameter and the display parameter are white gamma values.

21. The circuit of claim 20, wherein the detector determines the white gamma value of the reference signal based on the voltage ratio and at least one other monitor value.

22. The circuit of claim 21, wherein the at least one other monitor value includes brightness data for the monitor.

23. The circuit of claim 21, wherein the at least one other monitor value includes current data of the monitor.

24. The circuit of claim 21, wherein the detector determines the white gamma value of the reference signal based on the voltage ratio, brightness data of the monitor, and current data of the monitor.

25. The circuit of claim 20, wherein the white gamma value of the reference signal is detected based on the following formula:

White Gamma={Log(B2/B1)/Log(A2/A1)}/{Log(A1/A2)/Log(V1/V2)}

where B1 is brightness in the full white mode, B2 is brightness in the partial white mode, A1 is current in the full white mode, A2 is current in the partial white mode, V1 is voltage in the full white mode, and V2 is voltage in the partial white mode.

26. The circuit of claim 19, wherein the reference signal and video signal are RGB signals.

27. A monitor, comprising:

a video source for selectively outputting a first video signal and a second video signal;

a video processing unit for video-processing the selectively output video signal from said video source;

a color correction unit for detecting characteristic information of the video-processed first video signal, said color correction unit comparing the detected characteristic information to display characteristic information of the monitor and correcting, based on the comparison, a color of the second video signal output from said video source; and

a display unit for displaying the video signal output from said video processing unit.

28. The monitor of claim 27, further comprising:

a microcomputer for outputting a control signal for selecting the output from said video source of one of the first video signal or the second video signal, the output control signal being generated according to a display mode for user color correction.

29. The monitor of claim 28, wherein said color correction unit calculates, based on the comparison, a compensation value according to a display characteristic difference derived from said video source.

30. The monitor of claim 29, wherein said color correction unit performs color-correcting by overlapping, using the compensation value, the second video signal output from said video source and outputs the overlapped second video signal to said video processing unit.

31. The monitor of claim 29, wherein the compensation value is an RGB white gamma value.

32. The monitor of claim 29, wherein the compensation value is calculated based on:

$\frac{\mathrm{Log}<br><br>\left(\frac{\mathrm{B2}}{\mathrm{B1}}\right)}{\frac{\mathrm{Log}<br><br>\left(\frac{\mathrm{A2}}{\mathrm{A1}}\right)}{\frac{\mathrm{Log}<br><br>\left(\frac{\mathrm{A1}}{\mathrm{A2}}\right)}{\mathrm{Log}<br><br>\left(\frac{\mathrm{V1}}{\mathrm{V2}}\right)}}}$

where B1 and B2 are brightness values for a full white mode and for a partial white mode, respectively, where A1 and A2 are current values for the full white mode and the partial white mode, respectively, and where V1 and V2 are voltage values for the full white mode and the partial white mode, respectively.

33. The monitor of claim 32, wherein the partial white mode is a 70×

70 white mode.

34. The monitor of claim 27, wherein the first and second video signals are RGB signals and wherein the first video signal is a reference signal.