Drive apparatus and drive method for light emitting display panel

• US 20070085785A1
• Filed: 10/12/2006
• Published: 04/19/2007
• Est. Priority Date: 10/13/2005
• Status: Abandoned Application

• Current Assignee: Tohoku Pioneer Corporation (Pioneer Corporation)
• Original Assignee: Tohoku Pioneer Corporation (Pioneer Corporation)
• Inventors: Hayafuji, Akinori, Kanauchi, Katsuhiro, Ozaki, Mayumi
• Application Number:
  US11/546,533
• Publication Number:
  US 20070085785A1
• Time in Patent Office: Days
• US Class Current: 345/77
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2330/025 Reduction of instantaneous peaks of current
• CPC Class Codes: G09G 2330/028 Generation of voltages supplied to electrode drivers in a matrix display other than LCD
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/2025 the sub-frames having all the same time duration
• CPC Class Codes: G09G 3/3216 using a passive matrix
• CPC Class Codes: G09G 3/3258 with pixel circuitry controlling the voltage across the light-emitting element
• CPC Class Codes: G09G 3/3275 Details of drivers for data electrodes

Abstract

A drive apparatus is provided which can calculate a suitable APL value when driving a color display panel using PLE control. Further, a drive apparatus is provided which can inhibit output capacity of a power supply circuit by controlling display brightness according to a lighting rate of a pixel. An APL calculation means 20 is provided with a weighting means 22A for performing weighting according to a light emitting current rate of each color at the time of displaying a gray scale with respect to a picture signal of each of the colors R, G, and B. Being averaged by an averaging means 23, each signal weighted by this weighting means 22A acquires an APL value. The peak brightness control means 29 is controlled using this APL value so that PLE operation of controlling a peak brightness of the picture signal is realized. Further, a lighting rate calculation means for calculating the lighting rate of the pixel, in the display panel, which is lit and driven based on image data, and a brightness control means for controlling emission brightness of each of said pixels according to the lighting rate obtained by said lighting rate calculation means are provided.

Claims

1. A drive apparatus for a light-emitting display panel in which light emitting elements of a plurality of colors are arranged in a matrix pattern and each of said light emitting elements is selectively caused and driven to emit light based on a picture signal, said drive apparatus comprising:

an APL calculation means for calculating an average picture level (APL) from said picture signal, and a peak brightness control means for variably controlling peak brightness in said picture signal according to APL calculated by said APL calculation means, wherein

said APL calculation means is provided with a weighting means for weighting a picture signal of each color according to a light emitting current rate of each color at the time of displaying a gray scale.

3. The drive apparatus for the light-emitting display panel as claimed in claim 1 or 2, wherein said APL calculation means is further provided with a second weighting means for weighting a picture signal of each color according to an emission brightness rate of each color at the time of displaying the gray scale, and

a selection means for choosing either said weighting means or said second weighting means causes said picture signal of each color to be subjected to the weighting by said weighting means or the weighting by said second weighting means.

4. The drive apparatus for the light-emitting display panel as claimed in claim 1 or 2, wherein said APL calculation means is further provided with a second weighting means for weighting a picture signal of each color according to an emission brightness rate of each color at the time of displaying the gray scale, and

said picture signal of each color is subjected to weighting by said weighting means and weighting by said second weighting means.

2. A drive apparatus for a light-emitting display panel in which light emitting elements of a plurality of colors are arranged in a matrix pattern and each of said light emitting elements is selectively caused and driven to emit light based on a picture signal, said drive apparatus comprising:

an APL calculation means for calculating an average picture level (APL) from said picture signal, and a peak brightness control means for variably controlling peak brightness in said picture signal according to APL calculated by said APL calculation means, wherein

said APL calculation means is provided with a weighting means for weighting a picture signal of each color according to a light emitting power rate of each color at the time of displaying a gray scale.

5. A drive method for a light-emitting display panel in which light emitting elements of a plurality of colors are arranged in a matrix pattern and each of said light emitting elements is selectively caused and driven to emit light based on a picture signal, wherein

an average picture level (APL) is calculated from said picture signal by an APL calculation means, and

APL information data calculated by said APL calculation means are supplied as a control signal to a peak brightness control means, so as to perform variable control operation for peak brightness for variably controlling the peak brightness in said picture signal,

when calculating said average picture level, said APL calculation means performs weighting operation for weighting a picture signal of each color according to a light emitting current rate of each color at the time of displaying a gray scale.

6. A drive method for a light-emitting display panel in which light emitting elements of a plurality of colors are arranged in a matrix pattern and each of said light emitting elements is selectively caused and driven to emit light based on a picture signal, wherein

an average picture level (APL) is calculated from said picture signal by an APL calculation means, and

APL information data calculated by said APL calculation means are supplied as a control signal to a peak brightness control means, so as to perform variable control operation for peak brightness for variably controlling the peak brightness in said picture signal,

when calculating said average picture level, said APL calculation means performs weighting operation for weighting a picture signal of each color according to a light emitting power rate of each color at the time of displaying a gray scale.

7. A drive method for a light-emitting display panel in which light emitting elements of a plurality of colors are arranged in a matrix pattern and each of said light emitting elements is selectively caused and driven to emit light based on a picture signal, wherein

an average picture level (APL) is calculated from said picture signal by an APL calculation means, and

APL information data calculated by said APL calculation means are supplied as a control signal to a peak brightness control means, so as to perform variable control operation for peak brightness for variably controlling the peak brightness in said picture signal,

when calculating said average picture level, said APL calculation means selectively performs either first weighting operation for weighting a picture signal of each color according to a light emitting current rate of each color at the time of displaying a gray scale, or second weighting operation for weighting the picture signal of each color according to an emission brightness rate of each color at the time of displaying the gray scale.

8. A drive method for a light-emitting display panel in which light emitting elements of a plurality of colors are arranged in a matrix pattern and each of said light emitting elements is selectively caused and driven to emit light based on a picture signal, wherein

an average picture level (APL) is calculated from said picture signal by an APL calculation means, and

APL information data calculated by said APL calculation means are supplied as a control signal to a peak brightness control means, so as to perform variable control operation for peak brightness for variably controlling the peak brightness in said picture signal,

when calculating said average picture level, said APL calculation means selectively performs either first weighting operation for weighting a picture signal of each color according to a light emitting power rate of each color at the time of displaying a gray scale, or second weighting operation for weighting the picture signal of each color according to an emission brightness rate of each color at the time of displaying the gray scale.

9. A drive method for a light-emitting display panel in which light emitting elements of a plurality of colors are arranged in a matrix pattern and each of said light emitting elements is selectively caused and driven to emit light based on a picture signal, wherein

an average picture level (APL) is calculated from said picture signal by an APL calculation means, and

APL information data calculated by said APL calculation means are supplied as a control signal to a peak brightness control means, so as to perform variable control operation for peak brightness for variably controlling the peak brightness in said picture signal,

when calculating said average picture level, said APL calculation means performs first weighting operation for weighting a picture signal of each color according to a light emitting current rate of each color at the time of displaying a gray scale and second weighting operation for weighting the picture signal of each color according to an emission brightness rate of each color at the time of displaying the gray scale.

10. A drive method for a light-emitting display panel in which light emitting elements of a plurality of colors are arranged in a matrix pattern and each of said light emitting elements is selectively caused and driven to emit light based on a picture signal, wherein

an average picture level (APL) is calculated from said picture signal by an APL calculation means, and

APL information data calculated by said APL calculation means are supplied as a control signal to a peak brightness control means, so as to perform variable control operation for peak brightness for variably controlling the peak brightness in said picture signal,

when calculating said average picture level, said APL calculation means performs first weighting operation for weighting a picture signal of each color according to a light emitting power rate of each color at the time of displaying a gray scale and second weighting operation for weighting the picture signal of each color according to an emission brightness rate of each color at the time of displaying the gray scale.

11. A drive apparatus for a light-emitting display panel in which pixels each having a light emitting element are arranged at intersections where a plurality of data lines intersect with a plurality of scanning lines, and one frame (period) is divided into a plurality of sub-frames to realize gradation control by selecting said sub-frames (periods) and by summing the lighting periods of the pixel within one frame period,

said drive apparatus comprising a lighting rate calculation means for calculating a lighting rate of the pixel in said display panel to be lit and driven based on image data, and a brightness control means for controlling emission brightness of each of said pixels according to the lighting rate obtained by said lighting rate calculation means, wherein

said brightness control means is arranged to control the emission brightness of each of said pixels by controlling proportions of the lighting period and a non-lighting period of the pixel in one frame period based on said lighting rate.

12. The drive apparatus for the light-emitting display panel as claimed in claim 11, wherein

a data driver circuit for supplying lighting driving data to each of said pixels, a scanning driver circuit for lighting and scanning each of said pixels one by one, and a second scanning driver circuit for turning off and scanning each of said pixels one by one are provided, and

said brightness control means is arranged to control proportions of the lighting period and a non-lighting period of the pixel in said one frame period by controlling a scanning timing of said second scanning driver circuit.

13. The drive apparatus for the light-emitting display panel as claimed in claim 12, wherein each of said pixels is provided with at least said light emitting element, a drive transistor for controlling supply of lighting driving current to the light emitting element, a control transistor for controlling ON/OFF of said drive transistor, and electric capacitance for holding a gate voltage of said drive transistor.

14. The drive apparatus for the light-emitting display panel as claimed in claim 13, wherein each of said pixels further comprises an erase transistor for discharging electric charges held at said electric capacitance.

15. A drive method for a light-emitting display panel in which pixels each having a light emitting element are arranged at intersections where a plurality of data lines intersect with a plurality of scanning lines, and one frame (period) is divided into a plurality of sub-frames to realize gradation control by selecting said sub-frames (periods) and by summing the lighting periods of the pixel within one frame period, wherein

a lighting rate of the pixel in said display panel to be lit and driven is calculated based on image data, and emission brightness of each of said pixels is controlled by controlling proportions of the lighting period and a non-lighting period of the pixel in one frame period based on said calculated lighting rate.

18. The drive method for the light-emitting display panel as claimed in claim 15 or 17, wherein the emission brightness of each of said pixels is controlled to be small as said lighting rate becomes large.

16. A drive apparatus for a light-emitting display panel in which pixels each having a light emitting element are arranged at intersections where a plurality of data lines intersect with a plurality of scanning lines, said drive apparatus comprising a scanning driver for selectively setting each of said scanning lines as a scanning selection potential or a non-scanning selection potential, and a data driver for selectively connecting each of said data lines to a lighting driving power supply or a non-lighting driving power supply, said drive apparatus comprising:

a lighting rate calculation means for calculating a lighting rate of the pixel in said display panel to be lit and driven based on image data, and

a brightness control means for controlling emission brightness of each of said pixels according to the lighting rate obtained by said lighting rate calculation means, wherein

said brightness control means is arranged to control emission brightness of each of said pixels by controlling a period when said lighting driving power supply is connected with said data line based on said lighting rate.

17. A drive method for a light-emitting display panel in which pixels each having a light emitting element are arranged at intersections where a plurality of data lines intersect with a plurality of scanning lines, said display panel comprising a scanning driver for selectively setting each of said scanning lines as a scanning selection potential or a non-scanning selection potential, and a data driver for connecting each of said data lines to a lighting driving power supply or a non-lighting driving power supply, wherein

a lighting rate of the pixel in said display panel to be lit and driven is calculated based on image data, and emission brightness of each of said pixels is controlled by controlling a period when said lighting driving power supply is connected with said data line based on said calculated lighting rate.

19. A drive apparatus for a light-emitting display panel in which pixels each having a light emitting element are arranged at intersections where a plurality of data lines intersect with a plurality of scanning lines, and an image is displayed by selectively lighting and driving said pixels, said drive apparatus comprising:

a lighting rate calculation means for calculating a lighting rate of the pixel in said display panel to be lit and driven based on image data, and a brightness control means for controlling emission brightness of each of said pixels according to the lighting rate obtained by said lighting rate calculation means, wherein

said brightness control means controls emission brightness of each of said pixels by controlling an output value of a drive power supply to be provided for each of said pixels based on said lighting rate.

20. The drive apparatus for the light-emitting display panel as claimed in claim 19, wherein a drive voltage (value) supplied to each of said pixels is controlled based on said lighting rate.

21. The drive apparatus for the light-emitting display panel as claimed in claim 20, wherein the drive voltage (value) supplied to each of said pixels is obtained by means of a DC-DC converter.

22. The drive apparatus for the light-emitting display panel as claimed in claim 19, wherein drive current (value) supplied to each of said pixels is controlled based on said lighting rate.

23. A drive method for a light-emitting display panel in which pixels each having a light emitting element are arranged at intersections where a plurality of data lines intersect with a plurality of scanning lines, and an image is displayed by selectively lighting and driving said pixels, wherein

a lighting rate of the pixel in said display panel to be lit and driven is calculated based on image data, and emission brightness of each of said pixels is controlled by controlling an output value of a drive power supply to be provided for each of said pixels based on said calculated lighting rate.

24. The drive method for the light-emitting display panel as claimed in claim 23, wherein the emission brightness of each of said pixels is controlled to be small as the lighting rate becomes large.

25. A drive apparatus for a light-emitting display panel in which pixels each having a light emitting element are arranged at intersections where a plurality of data lines intersect with a plurality of scanning lines, and an image is displayed by selectively lighting and driving said pixels, said drive apparatus comprising:

a lighting rate calculation means for calculating a lighting rate of the pixel in said display panel to be lit and driven based on image data, and a brightness control means for controlling emission brightness of each of said pixels according to the lighting rate obtained by said lighting rate calculation means, wherein

said brightness control means is arranged to control the emission brightness of each of said pixels by performing a conversion process for said image data based on said lighting rate.

26. The drive apparatus for the light-emitting display panel as claimed in claim 25, wherein the conversion process for said image data is carried out based on said lighting rate so that a gradation value may be changed.

27. A drive method for a light-emitting display panel in which pixels each having a light emitting element are arranged at intersections where a plurality of data lines intersect with a plurality of scanning lines, and an image is displayed by selectively lighting and driving said pixels, wherein

a lighting rate of the pixel in said display panel to be lit and driven is calculated based on image data, and emission brightness of each of said pixels is controlled by performing a conversion process for said image data based on said calculated lighting rate.

28. The drive method for the light-emitting display panel as claimed in claim 27, wherein the emission brightness of each of said pixels is controlled to be small as the lighting rate becomes large.