Display panel conversion data deciding method and measuring apparatus

• US 20060290618A1
• Filed: 09/02/2004
• Published: 12/28/2006
• Est. Priority Date: 09/05/2003
• Status: Abandoned Application

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Goto, Masaharu
• Application Number:
  US10/558,911
• Publication Number:
  US 20060290618A1
• Time in Patent Office: Days
• US Class Current: 345/77
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2320/02 Improving the quality of display appearance
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 3/30 using electroluminescent panels

Abstract

A high-speed correction of display panel luminance variation is performed by use of a display panel conversion data deciding method, which comprises a first measuring step for determining a first driving current of the light emitting elements of the display panel when the capacitors of the pixels other than pixels to be measured have not completely been discharged; a charging step for charging, by an analog voltage, the capacitors of the pixels to be measured; a second measuring step for determining a first driving current of the light emitting elements of the display panel when the capacitors of the pixels to be measured have been charged by the analog voltage; a driving current calculating step for determining, from the difference between the first and second driving currents, the driving current of the pixels to be measured; and a data calculating step for determining conversion data based on the driving current.

Claims

1. A method for determining the conversion data of a display panel, characterized in that it is a method for determining the conversion data of a display device having

a display panel, wherein there are disposed in matrix form multiple pixels, each having a capacitor, a drive circuit for controlling current or voltage based on the voltage of the capacitor, and a self-emitting element driven by the drive circuit, and

a luminance signal generating means for applying to the capacitor an analog voltage obtained by conversion of luminance data based on conversion data, comprises the steps of:

a first measurement step for finding a first driving current of the light-emitting elements of the display panel when the capacitors of the pixels other than the pixel under test have not been completely discharged;

a charging step for charging the capacitor of the pixel under test to the analog voltage;

a second measurement step for measuring a second driving current of the light-emitting elements of the display panel when the capacitor of the pixel under test has been charged to the analog voltage;

a driving current calculation step for finding the driving current of the pixel under test from the difference between the first driving current and the second driving current; and

a data calculation step for finding the conversion data based on the driving current.

2. The method of claim 1, wherein the self-emitting element is an EL element.

3. The method of claim 1, wherein the first measurement step is executed every time a specific number of pixels is measured and;

the first driving current of the pixel under test is found by interpolation from the driving current actually measured in the first measurement step immediately before and immediately after the pixel under test.

4. A display device comprises:

a display panel, wherein there are disposed in matrix form multiple pixels, each having a capacitor, a drive circuit for controlling current or voltage based on the voltage of the capacitor, and a self-emitting element driven by the drive circuit;

a selection means for selecting any pixel under test;

a luminance signal generating means for applying to the capacitor an analog voltage obtained by conversion of luminance data based on conversion data;

a measurement means for measuring the driving current of the light-emitting elements of the multiple pixels; and

a conversion data determination means for finding the conversion data based on the difference between the first driving current of the light-emitting elements of the multiple pixels when the capacitors of pixels other than the pixel under test have not been completely discharged and the second driving current of the light-emitting elements of the multiple pixels when the capacitor of the pixel under test has been charged to the analog voltage.

5. A measuring apparatus of a display panel, characterized in that it is a measuring apparatus of a display panel wherein there are disposed in matrix form multiple pixels, each having a capacitor, a drive circuit for controlling current or voltage based on the voltage of the capacitor, and a self-emitting element driven by the drive circuit, comprises:

a selection means for selecting any pixel under test,

a luminance signal generating means for applying to the capacitor an analog voltage obtained by conversion of luminance data based on conversion data;

a measurement means for measuring the driving current of the light-emitting elements of the multiple pixels;

a conversion data determination means for finding the conversion data based on the difference between the first driving current of the light-emitting elements of the multiple pixels when the capacitors of pixels other than the pixel under test have not been completely discharged and the second driving current of light-emitting elements of multiple pixels when the capacitor of the pixel under test has been charged to the analog voltage; and

an output means for outputting the conversion data.

6. A method for determining conversion data of a display panel, characterized in that it is a method for determining the conversion data of a display device having a display panel, wherein there are disposed in matrix form multiple pixels, each having a capacitor, a drive circuit for controlling current or voltage based on the voltage of the capacitor, and a self-emitting element driven by the drive circuit, and

a luminance signal generating means for applying to the capacitor an analog voltage obtained by conversion of luminance data based on conversion data, comprises the steps of:

a first measurement step for finding the first emission luminance of the display panel when the capacitors of pixels other than the pixel under test have not been completely discharged;

a charging step for charging the capacitor of the pixel under test to the analog voltage,

a second measurement step for measuring the second emission luminance of the display panel when the capacitor of the pixel under test has been charged to the analog voltage;

an emission luminance calculation step for finding the emission luminance of the pixel under test from the difference between the first emission luminance and the second emission luminance; and

a data calculation step for finding the conversion data based on the emission luminance.

7. A method for determining the conversion data of a display panel, having a display panel comprising a TFT array and self-emitting elements;

a luminance signal generating means for generating luminance signals by converting luminance data to conversion data;

a drive means for driving the self-emitting elements by the luminance signals, and a measurement means for measuring the driving current and/or emission luminance of the light-emitting elements of the TFT array,

comprises the steps of;

a step for driving the self-emitting element of the pixel under test,

a step for performing the measurement before the driving current or emission luminance of the pixel under test has reached a steady state; and

a step for determining the conversion data based on the results of the measurement.