OLED display apparatus

• US 7,982,693 B2
• Filed: 06/06/2005
• Issued: 07/19/2011
• Est. Priority Date: 06/15/2004
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Inventors: Kohno, Makoto, Mori, Nobuyuki, Mizukoshi, Seiichi
• Primary Examiner(s): Hjerpe; Richard
• Assistant Examiner(s): HARRIS, DOROTHY H
• Application Number:
  US11/570,093
• Publication Number:
  US 20080297448A1
• Time in Patent Office: 2,234 Days
• Field of Search: 345 76- 77, 345/589
• US Class Current: 345/76
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2340/0457 Improvement of perceived resolution by subpixel rendering
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: H10K 59/351 comprising more than three subpixels, e.g. red-green-blue-white [RGBW]

Abstract

An organic light emitting diode (OLED) display apparatus having four types of light producing dots, including R (red), G (green), B (blue), and W (white) dots, includes detecting the amount of high frequency components of a portion of a color image to be displayed, or calculating average brightness or power of display from input image data; or detecting the amount of current flowing in display; or responding to a user input instruction; or responding to a battery capacity; and adaptively changing the usage ratio of W dots accordingly.

Claims

1. An organic light emitting diode (OLED) display apparatus, comprising:

(a) means for detecting the amount of high frequency components of a target pixel of a color image to be displayed, wherein the color image includes an input RGB signal for each of a plurality of pixels;

(b) means for calculating a respective conversion coefficient between 0 and 1 for the target pixel in accordance with the result of the detection and the spatial position of the pixel;

(c) means for converting the input RGB signals for the target pixel to RGBW signals for that pixel using the respective conversion coefficient; and

(d) a plurality of pixels each having a R (red), a G (green), a B (blue), and a W (white) dot for producing light in response to the corresponding RGBW signals, so that when the conversion coefficient for a pixel is less than 1, the R, G, B and W dots in the pixel all emit light simultaneously,

wherein the conversion coefficient determines a usage ratio of the W dot.

2. The OLED display apparatus of claim 1, further including a battery and a battery capacity detection circuit;

wherein the conversion coefficients are increased when the battery capacity detection circuit indicates that the battery capacity is less than a predetermined value.

11. The OLED display apparatus according to any one of claims 1-5, 6, 8 and 10, wherein the conversion coefficient is calculated based on response characteristics of a two-dimensional high pass filter with respect to a unit impulse, response characteristics of a two-dimensional low pass filter with respect to a unit impulse, and a signal level corresponding to a dot at the spatial position.

3. An organic light emitting diode (OLED) display apparatus, comprising:

(a) means for calculating the average brightness or electric power necessary for display of a color image from input image data of one screen, wherein the color image includes an input RGB signal for each of a plurality of pixels;

(b) means for calculating a respective conversion coefficient between 0 and 1 for each pixel in accordance with the result of such calculation;

(c) means for converting the input RGB signals for each pixel to RGBW signals for that pixel using the respective conversion coefficient; and

(d) a plurality of pixels, each having a R (red), a G (green), a B (blue), and a W (white) dot for producing light in response to the corresponding RGBW signals, so that when the conversion coefficient for a pixel is less than 1, the R, G, B and W dots in the pixel all emit light simultaneously.

4. The organic light emitting diode (OLED) display apparatus of claim 3, wherein the conversion coefficient is calculated to adaptively change the usage ratio of the W dots depending on the spatial position of the W dot.

5. An organic light emitting diode (OLED) display apparatus, comprising:

(a) a current detection circuit for detecting an electric current flowing through the OLED for achieving display in accordance with input image data, wherein the color image includes an input RGB signal for each of a plurality of pixels;

(b) means for calculating a respective conversion coefficient between 0 and 1 for each pixel in accordance with the detected electric current and the spatial position of the pixel;

(c) means for converting the input RGB signals for each pixel to RGBW signals for that pixel using the respective conversion coefficient; and

(d) a plurality of pixels each having a R (red), a G (green), a B (blue), and a W (white) dot for producing light in response to the corresponding RGBW signals, so that when the conversion coefficient for a pixel is less than 1, the R, G, B and W dots in the pixel all emit light simultaneously,

wherein the conversion coefficient determines a usage ratio of the W dot.

6. An organic light emitting diode (OLED) display apparatus, comprising:

(a) a calculation circuit to detect the amount of high frequency components of a target pixel of a color image to be displayed, wherein the color image includes an input RGB signal for each of a plurality of pixels, and to calculate a respective conversion coefficient between 0 and 1 for each pixel in accordance with the result of the detection and the spatial position of the pixel;

(b) a conversion circuit connected to the calculation circuit to receive the respective conversion coefficient and to convert the input RGB signals for each pixel to RGBW signals for that pixel using the respective conversion coefficient; and

(c) a plurality of pixels each having a R (red), a G (green), a B (blue), and a W (white) dot to produce light in response to the corresponding RGBW signals, so that when the conversion coefficient for a pixel is less than 1, the R, G, B and W dots in the pixel all emit light simultaneously,

wherein the conversion coefficient determines a usage ratio of the W dot.

7. The organic OLED display apparatus of claim 6, further including a battery and a battery capacity detection circuit;

wherein the conversion coefficients are increased when the battery capacity detection circuit indicates that the battery capacity is less than a predetermined value.

8. An organic light emitting diode (OLED) display apparatus, comprising:

(a) a calculation section to calculate the average brightness or electric power necessary for display of a color image from input image data of one screen, wherein the color image includes an input RGB signal for each of a plurality of pixels;

(b) a calculation circuit connected to the calculation section to receive the average brightness or electric power and to calculate a respective conversion coefficient between 0 and 1 for each pixel in accordance with the result of such calculation;

(c) a conversion circuit connected to the calculation circuit to receive the respective conversion coefficient and to convert the input RGB signals for each pixel to RGBW signals for that pixel using the respective conversion coefficient; and

(d) a plurality of pixels, each having a R (red), a G (green), a B (blue), and a W (white) dot to produce light in response to the corresponding RGBW signals, so that when the conversion coefficient for a pixel is less than 1, the R, G, B and W dots in the pixel all emit light simultaneously.

9. The organic light emitting diode (OLED) display apparatus of claim 8, wherein the conversion coefficient is calculated to adaptively change the usage ratio of the W dots depending on the spatial position of the W dot.

10. An organic light emitting diode (OLED) display apparatus, comprising:

(a) a calculation section to detect an electric current flowing through the OLED for achieving display in accordance with input image data, wherein the color image includes an input RGB signal for each of a plurality of pixels;

(b) a calculation circuit connected to the calculation section to receive the electric current and to calculate a respective conversion coefficient between 0 and 1 for each pixel in accordance with the detected electric current and the spatial position of the pixel;

(c) a conversion circuit connected to the calculation circuit to receive the respective conversion coefficient and to convert the input RGB signals for each pixel to RGBW signals for that pixel using the respective conversion coefficient; and

(d) a plurality of pixels each having a R (red), a G (green), a B (blue), and a W (white) dot to produce light in response to the corresponding RGBW signals, so that when the conversion coefficient for a pixel is less than 1, the R, G, B and W dots in the pixel all emit light simultaneously,

wherein the conversion coefficient determines a usage ratio of the W dot.