METHOD FOR ADJUSTING WHITE BALANCE IN A FIELD SEQUENTIAL DISPLAY AND DEVICE THEREOF

• US 20100045579A1
• Filed: 01/23/2009
• Published: 02/25/2010
• Est. Priority Date: 08/20/2008
• Status: Active Grant

• Current Assignee: Chunghwa Picture Tubes Limited (Tatung Co., Ltd.)
• Original Assignee: Chunghwa Picture Tubes Limited (Tatung Co., Ltd.)
• Inventors: Chou, Chih-Sheng, Lu, Qi-Ming, Chen, Hung-Hsiang
• Granted Patent: US 8,207,919 B2
• Time in Patent Office: Days
• US Class Current: 345/83
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix

Abstract

A method for adjusting white balance includes generating a first matrix according to values in axes of a color gamut corresponding to optical characteristics of a plurality of first LEDs; generating a second matrix according to values in the axes of the color gamut corresponding to optical characteristics of the plurality of first LEDs while in white balance; generating a third matrix according to values in the axes of the color gamut corresponding to optical characteristics of a plurality of second LEDs; storing the first matrix, second matrix, and third matrix; generating a calibration matrix by multiplying the second matrix with an inverse of the first matrix; generating a fourth matrix by multiplying the third matrix with the calibration matrix. As a result, the optical characteristics of the plurality of second LEDs can be effectively and rapidly adjusted simply referring to the differences between the second and fourth matrices.

Claims

1. A method for adjusting white balance in a field sequential display (FSD) comprising:

generating a first matrix according to values in axes of a color gamut corresponding to optical characteristics of at least one first red, green, and blue light emitting diodes (LEDs) respectively;

storing the first matrix;

generating a second matrix according to values in the axes of the color gamut corresponding to the optical characteristics of the at least one first red, green, and blue LEDs respectively while in white balance;

storing the second matrix;

generating a third matrix according to values in the axes of the color gamut corresponding to optical characteristics of at least one second red, green, and blue LEDs respectively;

storing the third matrix;

generating a calibration matrix by multiplying the second matrix with an inverse of the first matrix;

generating a fourth matrix by multiplying the third matrix with the calibration matrix; and

adjusting the optical characteristics of the at least one second red, green, and blue LEDs referring to differences between the second and fourth matrices.

2. The method of claim 1 wherein adjusting the optical characteristics of the at least one second red, green, and blue LEDs referring to the differences between the second and fourth matrices comprises adjusting duty ratios of pulse width modulation (PWM) of the at least one second red, green, and blue LEDs respectively referring to the differences between the second and fourth matrices.

3. The method of claim 1 wherein adjusting the optical characteristics of the at least one second red, green, and blue LEDs referring to the differences between the second and fourth matrices comprises adjusting currents flowing through the at least one second red, green, and blue LEDs respectively so as to change luminance of the at least one second red, green, and blue LEDs respectively referring to the differences between the second and fourth matrices through analog voltages outputted from a digital/analog (D/A) converter.

4. A method for adjusting white balance in an FSD comprising:

generating a first matrix according to values in axes of a color gamut corresponding to optical characteristics of at least one first red, green, and blue LEDs respectively;

storing the first matrix;

generating a second matrix according to values in the axes of the color gamut corresponding to the optical characteristics of the at least one first red, green, and blue LEDs respectively while in white balance;

storing the second matrix;

generating a calibration matrix by multiplying the second matrix with an inverse of the first matrix;

storing the calibration matrix;

generating a third matrix according to values in the axes of the color gamut corresponding to optical characteristics of at least one second red, green, and blue LEDs respectively;

storing the third matrix;

calculating a fourth matrix by multiplying the third matrix with the calibration matrix; and

adjusting the optical characteristics of the at least one second red, green, and blue LEDs referring to differences between the second and fourth matrices.

5. The method of claim 4 wherein adjusting the optical characteristics of the at least one second red, green, and blue LEDs referring to the differences between the second and fourth matrices comprises adjusting duty ratios of PWM of the at least one second red, green, and blue LEDs respectively referring to the differences between the second and fourth matrices.

6. The method of claim 4 wherein adjusting the optical characteristics of the at least one second red, green, and blue LEDs referring to the differences between the second and fourth matrices comprises adjusting currents flowing through the at least one second red, green, and blue LEDs respectively so as to change luminance of the at least one second red, green, and blue LEDs respectively referring to the differences between the second and fourth matrices through analog voltages outputted from a D/A converter.

7. A device for adjusting white balance in an FSD comprising:

a first device for generating a first matrix according to values in axes of a color gamut corresponding to optical characteristics of at least one first red, green, and blue LEDs respectively;

a second device for generating a second matrix according to values in the axes of the color gamut corresponding to the optical characteristics of the at least one first red, green, and blue LEDs respectively while in white balance;

a third device for generating a third matrix according to values in the axes of the color gamut corresponding to optical characteristics of at least one second red, green, and blue LEDs respectively;

a storing device for storing the first matrix, the second matrix, and the third matrix;

a calculating device for generating a calibration matrix by multiplying the second matrix with an inverse of the first matrix, and generating a fourth matrix by multiplying the third matrix with the calibration matrix; and

an adjusting device for adjusting the optical characteristics of the at least one second red, green, and blue LEDs referring to differences between the second and fourth matrices.

8. The device of claim 7 wherein the adjusting device is for adjusting duty ratios of PWM of the at least one second red, green, and blue LEDs respectively referring to the differences between the second and fourth matrices.

9. The device of claim 7 wherein the adjusting device is for adjusting currents flowing through the at least one second red, green, and blue LEDs respectively so as to change luminance of the at least one second red, green, and blue LEDs respectively referring to the differences between the second and fourth matrices through analog voltages outputted from a D/A converter.

10. A device for adjusting white balance in an FSD comprising:

a first device for generating a first matrix according to values in axes of a color gamut corresponding to optical characteristics of at least one first red, green, and blue LEDs respectively;

a second device for generating a second matrix according to values in the axes of the color gamut corresponding to the optical characteristics of the at least one first red, green, and blue LEDs respectively while in white balance;

a calculating device for calculating a calibration matrix by multiplying the second matrix with an inverse of the first matrix;

a third device for generating a third matrix according to values in the axes of the color gamut corresponding to optical characteristics of at least one second red, green, and blue LEDs respectively;

a storing device for storing the first matrix, the third matrix, and the calibration matrix; and

an adjusting device for adjusting the optical characteristics of the at least one second red, green, and blue LEDs referring to differences between the second and a fourth matrices, wherein the fourth matrix is generated by multiplying the third matrix with the calibration matrix through the calculating device.

11. The device of claim 10 wherein the adjusting device is for adjusting duty ratios of PWM of the at least one second red, green, and blue LEDs respectively referring to the differences between the second and fourth matrices.

12. The device of claim 10 wherein the adjusting device is for adjusting currents flowing through the at least one second red, green, and blue LEDs respectively so as to change luminance of the at least one second red, green, and blue LEDs respectively referring to the differences between the second and fourth matrices through analog voltages outputted from a D/A converter.