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US 2002/0158882 A1Published application
Auto gamma correction system and method for displays with adjusting reference voltages of data drivers
OwnerMing-Jiun Liaw, Ming-Daw Chen +1inventors
InventorsMing-Jiun Liaw, Ming-Daw Chen, Ho-Hsin Yang
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Abstract
This invention is related to an auto Gamma correction system for displays with adjusting reference voltages of data drivers, wherein a novel correction method by adjusting the external reference voltages of the data drivers was proposed. The auto gamma correction system mainly includes an auto gamma correction system coupled to the data drivers. The auto gamma correction system outputs plurality adjustable Gamma voltages coupled to the data drivers to drive the display without any gray level loss. Further, because of its requirement of no detector or just low-cost detectors, the invention enables display manufactories to get the advantage of cost-down.
Claims18
An auto gamma correction system for displays with adjusting reference voltages of data drivers, comprising:
- a CPU, computing a string of digital codes that will be referenced during the correction process;
- an image generator, coupling to the CPU to generate at least two kinds of gray patches;
- a memory, coupling with the CPU to store a set of target values of Gamma reverence voltages of data drivers, code-to-voltage transfer functions of the data drivers, and at least a target code-to-optical-response curve;
- a group of programmable Gamma voltage generating circuits, providing Gamma reference voltages to the data drivers according to numerical values computed by the CPU, such that the target code-to-optical-response curve can be achieved;
- a group of data drivers, requiring a series of external reference voltages, hereinafter referred as Gamma reference voltages or Gamma voltages, to generate outnumbered analog voltages for the display to present adequate gray levels;
- and
- wherein, the CPU determines the target Gamma reference voltages based on users' visual matching process after taking into considerations the data drivers' code-to-voltage transfer functions, then produces a better image quality without any loss of gray-levels.
4 more elements
An auto gamma correction method for displays with adjusting reference voltages of data drivers, which uses spatial dithering technology cooperated with two gray levels to generate an arbitrary gray patch, comprising:
- (a) selecting adjacent two of Gamma reference voltages, wherein several gray levels exist, to be first corrected;
- then generating two gray patches, one is generated by spatial dithering technology, the other is a continuous pixel gray patch;
- luminance of these two patches should be within those bounded by the two selected Gamma voltages;
- (b) adjusting the digital code of the continuous pixel gray patch from a distance, until the luminance of continuous pixel gray patch looks matching that of the spatial dithering gray patch, then recording the final digital code d1 of the continuous pixel gray patch;
- (c) generating another two gray patches that differ from those of the step (a), one is generated by spatial dithering technology, the other is a continuous pixel gray patch;
- (d) adjusting the digital code of the continuous pixels gray patch from a distance, until the luminance of gray patch looks matching that of the spatial dithering gray patch, then recording the final digital code d2 of the continuous pixel gray patch;
- (e) figuring out the voltage values (Vd1, Vd2) corresponded to the digital codes (d1, d2) by the interpolation method with the built-in code-to-voltage transfer function;
- (f) finding out final target voltage values for the two selected external Gamma reference voltages;
- (g) repeating the steps (c)-(f) until the target numerical values of all Gamma reference voltages are figured out;
- (h) adjusting the Gamma voltages to match with their target values by the programmable Gamma voltage generating circuits;
- and applying these Gamma voltages to the data drivers, then storing the adjusted Gamma reference voltages into a memory to complete the auto Gamma correction.
8 more elements
An auto gamma correction method for displays with adjusting reference voltages of data drivers, by spatial-dithering technology with two specific gray-levels to generate an arbitrary gray patch, comprising:
- (a) selecting two of Gamma reference voltages, wherein several gray levels exist, to be corrected at first;
- then generating two gray patches, one is generated by spatial dithering technology, the other is a continuous pixel gray patch;
- their luminance should be within those bounded by the two selected Gamma voltages;
- (b) adjusting the digital code of the continuous pixel gray patch from a distance, until the luminance of continuous pixel gray patch looks matching that of the spatial dithering gray patch, then recording the final digital code d1 of the continuous pixel gray patch;
- (c) generating another two gray patches that different from those of the step (a), one is generated by spatial dithering technology, the other is a continuous pixel gray patch;
- (d) adjusting the digital code of the continuous pixels gray patch from a distance, until the luminance of gray patch looks matching that of the spatial dithering gray patch, recording the final digital code d2 of the continuous pixel gray patch;
- (e) figuring out the voltage values (Vd1, Vd2) corresponded to the digital codes (d1, d2) by the lookup table and the interpolation method;
- (f) finding out the final target voltages for the two selected external Gamma reference voltages;
- (g) adjusting the two external Gamma reference voltages of step (f) to their target values by a group of programmable Gamma voltage generating circuits, then applying the determined voltages to data drivers;
- (h) selecting another one Gamma voltage to be next adjusted;
- then determining the gray-level of the spatial-dithering gray patch for this selected Gamma voltage according to a set of pre-storage gray levels corresponded to the external reference voltages of the data drivers;
- (i) generating a gray patch with the determined gray level by means of spatial dithering technology;
- then determining the target value of this Gamma voltage via the users' visual matching process.
- (j) adjusting the input Gamma voltage of data drivers to its target value by the programmable Gamma voltage generating circuits.
- (k) repeating step(h)˜(j) until all the Gamma reference voltages have been set.
12 more elements
An auto gamma correction method for displays with adjusting reference voltages of data drivers, which adjusting the external voltages of the data drivers directly, comprising:
- (a) generating two gray patches, one is produced by the spatial dithering and its luminance can be theoretically presented by a special digital code (d1), the other is generated by continuous pixels with a single one gray-level which could be adjusted by user;
- (b) applying one voltage to both the upper and lower external voltages of the continuous pixel gray patches, such that the luminance of all gray-levels within the two selected upper and lower external voltages are all the same;
- (c) adjusting the voltage applied to the upper and lower external voltages via changing the digital code of the continuous pixel gray patch when users are observing the gray patch from a distance;
- (d) recording the final voltage (Vd1) into a memory when the luminance of the adjusted continuous pixel gray patch looks matching that of the spatial dithering gray patch;
- (e) generating two gray patches that differ from those of the step 1, one is produced by the spatial dithering and its luminance can be theoretically presented by a special digital code (d2), the other is a continuous pixel gray patch;
- (f) applying one voltage to both the upper and lower external voltages of the continuous pixel gray patches, such that the luminance of all gray-levels within the two selected upper and lower external voltages are the same, then repeating the steps (c)˜(d) to obtain another final voltage (Vd2);
- (g) determining two voltage values for the selected upper and lower external Gamma reference voltages based on the two gray-levels d1 and d2 with the voltages Vd1 and Vd2 further cooperating with the built-in voltage-to-code transfer function;
- (h) repeating the processing of steps (a)˜(g) to figure out all the external Gamma reference voltages of data drivers.
5 more elements
An auto gamma correction system for displays with adjusting reference voltages of data drivers, comprising:
- at least a detector, measuring the optical energy emitting from the displays;
- a CPU, coupling with the detector to record the optical energy values, and computing a new string of Gamma voltages to be adjusted during the correction process;
- an image generator, coupling to the CPU to generate at least two kinds of gray patches;
- a memory, coupling with the CPU to store the target numerical values of Gamma reverence voltages and at least a target code-to-optical-response curve;
- a group of programmable Gamma voltage generating circuits, providing Gamma voltages to the data drivers according to numerical values computed by the CPU, such that the target code-to-optical-response curve can be achieved;
- and
- wherein, the CPU takes into considerations the data drivers' code-to-voltage transfer functions to determine the target Gamma reference voltages according to the detect and comparison results from the detector;
- then produces a better image quality without any loss of gray-levels.
5 more elements
Dependencies are inferred from the claim text.