CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0109882 filed on Sep. 13, 2018 in the Korean Intellectual Property Office (KIPO), the entire content of which is incorporated herein by reference.

BACKGROUND

1. Field

An embodiment of the present invention relates to display devices, and more particularly to image data correcting devices, and display devices including the image data correcting devices.

2. Description of the Related Art

Even if a plurality of pixels included in a display device are manufactured by the same process, the plurality of pixels may have different luminance due to a process variation, and/or the like, and thus a mura defect may occur in the display device. To reduce or eliminate the mura defect, and to improve luminance uniformity of the display device, an image displayed by the display device in a module state may be captured, correction data may be generated based on the captured image, and the correction data may be stored in the display device. The display device may correct image data based on the stored correction data, and may display an image based on the corrected image data, thereby displaying the image with uniform luminance and without the mura defect.

To prevent or protect from a takt time for the display device and a storage space for the correction data from being excessively increased, the correction data may be obtained and stored not on a pixel-by-pixel basis, but on a sampling window-by-sampling window basis, and a sampling window may correspond to a plurality of pixels. With respect to related art display devices, a single square sampling window, e.g., an 8*8 sampling window may be used to capture, store and use the correction data, and thus optimal or desired mura correction may not be performed for all different display devices.

SUMMARY

Aspects of some example embodiments are directed toward an image data correcting device capable of performing optimal or desired mura correction.

Aspects of some example embodiments are directed toward a display device including an image data correcting device capable of performing optimal or desired mura correction.

According to example embodiments, there is provided an image data correcting device included in a display device including a correction data memory configured to store sampling window select information indicating a sampling window selected from a plurality of sampling windows that are different from each other, and correction data obtained utilizing the selected sampling window with respect to the display device, and a correction calculator configured to receive image data, and to correct the image data based on the correction data for pixels at positions corresponding to the selected sampling window indicated by the sampling window select information.

In example embodiments, the selected sampling window indicated by the sampling window select information may be selected based on a luminance distribution of the display device from among the plurality of sampling windows.

In example embodiments, the plurality of sampling windows may have different row direction lengths and different column direction lengths, and may have a same size.

In example embodiments, a display panel of the display device may be divided into a plurality of pixel blocks, each corresponding to the selected sampling window indicated by the sampling window select information, and the correction data stored in the correction data memory may include, with respect to each pixel block, a pixel correction data at a plurality of reference gray levels for a representative pixel from among the pixels included in the each pixel block.

In example embodiments, the representative pixel may be a pixel located at a top left corner from among the pixels included in the each pixel block.

In example embodiments, the sampling window select information may include a row direction length and a column direction length of the selected sampling window.

In example embodiments, a display panel of the display device may be divided into a plurality of pixel blocks based on the selected sampling window, and the correction data may include a plurality of pixel correction data for a plurality of representative pixels respectively corresponding to the plurality of pixel blocks. The correction calculator may extract, with respect to each pixel of the display panel, the plurality of pixel correction data for the representative pixels that are adjacent to the each pixel based on the row direction length of the selected sampling window, the column direction length of the selected sampling window, a row direction position of the each pixel, and a column direction position of the each pixel, and may correct the image data for the each pixel by performing a bilinear interpolation on the pixel correction data for the adjacent representative pixels.

In example embodiments, the correction calculator may extract the pixel correction data for the adjacent representative pixels utilizing equations, P0=(└X/X_SIZE┘)+(└Y/Y_SIZE┘)*(┌NUM_COL/X_SIZE┐+1), P1=(└X/X_SIZE┘+1)+(└Y/Y_SIZE┘)*(┌NUM_COL/X_SIZE┐+1), P2=(└X/X_SIZE┘)+(└Y/Y_SIZE┘+1)*(┌NUM_COL/X_SIZE┐+1), and P3=(└X/X_SIZE┘+1)+(└Y/Y_SIZE ┘+1)*(┌NUM_COL/X_SIZE┐+1), where P0, P1, P2 and P3 represent indexes of the pixel correction data for the adjacent representative pixels, X_SIZE represents the row direction length of the selected sampling window, Y_SIZE represents the column direction length of the selected sampling window, X represents the row direction position of the each pixel, Y represents the column direction position of the each pixel, and NUM_COL represents a number of pixel columns of the display panel.

In example embodiments, the correction calculator may perform the bilinear interpolation utilizing an equation, CD[P0]+((X % X_SIZE)/X_SIZE))*(CD[P1]−CD[P0])+((Y % Y_SIZE)/Y_SIZE))*(CD[P2]−CD[P0])+((X % X_SIZE)*(Y % Y_SIZE)/X_SIZE*Y_SIZE))*(CD[P0]+CD[P3]−CD[P1]−CD[P2]), where CD[P0], CD[P1], CD[P2] and CD[P3] are the pixel correction data having the indexes of P0, P1, P2 and P3.

In example embodiments, the correction calculator may perform the bilinear interpolation at each of a plurality of reference gray levels, and the correction calculator may correct the image data for the each pixel by further performing a linear interpolation between gray levels on results of the bilinear interpolation at the plurality of reference gray levels.

According to example embodiments, there is provided an image data correcting device included in a display device including a correction data memory configured to store correction data that is obtained with respect to the display device utilizing a plurality of sampling windows at a plurality of reference gray levels, respectively, and a correction calculator configured to receive image data, to select at least one sampling window according to a gray level of the image data from among the plurality of sampling windows, and to correct the image data based on the correction data for pixels at positions corresponding to the selected sampling window.

In example embodiments, the plurality of reference gray levels may include a first reference gray level, and a second reference gray level higher than the first reference gray level, and the plurality of sampling windows may include a first sampling window corresponding to the first reference gray level, and a second sampling window corresponding to the second reference gray level. The second sampling window may be greater in size than that of the first sampling window.

In example embodiments, the correction calculator may include a plurality of correction data buffers configured to temporarily store the correction data at the plurality of reference gray levels, a space interpolator configured to generate the correction data for all the pixels included in a display panel of the display device by performing, with respect to each pixel of the display panel, a bilinear interpolation on a plurality of pixel correction data for representative pixels that are adjacent to the each pixel from among the plurality of pixel correction data included in the correction data at each of the plurality of reference gray levels, and a gray interpolator configured to receive, with respect to the each pixel, the correction data at two of the reference gray levels that are adjacent to the gray level of the image data for the each pixel from among the correction data at the plurality of reference gray levels from the space interpolator, and to correct the image data for the each pixel by performing a linear interpolation on the correction data at the two of the reference gray levels.

In example embodiments, the plurality of reference gray levels may include a first reference gray level, and a second reference gray level higher than the first reference gray level, and the plurality of correction data buffers may include a first correction data buffer configured to temporarily store the correction data at the first reference gray level, and a second correction data buffer configured to temporarily store the correction data at the second reference gray level. The second correction data buffer may be less in size than that of the first correction data buffer.

In example embodiments, the plurality of correction data buffers includes two correction data buffers per each of the plurality of reference gray levels, and each of the two correction data buffers may temporarily store the correction data corresponding to representative pixels in one row, and may update one of the two correction data buffers each time the image data for the pixels in rows corresponding to a column direction length of the sampling window corresponding to each of the plurality of reference gray levels are received.

In example embodiments, the space interpolator may perform the bilinear interpolation utilizing an equation, “CD[P0]+((X % X_SIZE)/X_SIZE))*(CD[P1]−CD[P0])+((Y % Y_SIZE)/Y_SIZE))*(CD[P2]−CD[P0])+((X % X_SIZE)*(Y % Y_SIZE)/X_SIZE*Y_SIZE))*(CD[P0]+CD[P3]−CD[P1]−CD[P2])”, where P0, P1, P2 and P3 represent indexes of the pixel correction data for the adjacent representative pixels, CD[P0], CD[P1], CD[P2] and CD[P3] are the pixel correction data having the indexes of P0, P1, P2 and P3, X_SIZE represents a row direction length of the sampling window, Y_SIZE represents a column direction length of the sampling window, X represents a row direction position of the each pixel, Y represents a column direction position of the each pixel, and NUM_COL represents a number of pixel columns of the display panel.

In example embodiments, the gray interpolator may perform the linear interpolation on the correction data at the two of the reference gray levels utilizing an equation, “Y1+(X_I−X1)*(Y2−Y1)/(X2−X1)”, where X_I represents the image data for the each pixel, X1 represents a first reference gray level among the two of the reference gray levels, X2 represents a second reference gray level among the two of the reference gray levels, Y1 represents the correction data for the each pixel at the first reference gray level, and Y2 represents the correction data for the each pixel at the second reference gray level.

According to example embodiments, there is provided a display device including a display panel including pixels, an image data correcting device including a correction data memory configured to store correction data, and a correction calculator configured to receive image data, to select a sampling window from among a plurality of sampling windows that are different from each other, and to correct the image data based on the correction data for the pixels at positions corresponding to the selected sampling window, and a data driver configured to generate data signals based on the corrected image data, and to provide the data signals to the pixels.

In example embodiments, the correction data memory may further store sampling window select information indicating the selected sampling window, and the correction calculator may select the sampling window based on the sampling window select information from among the plurality of sampling windows.

In example embodiments, the correction calculator may select the sampling window according to a gray level of the image data from among the plurality of sampling windows.

As described above, the image data correcting device and the display device including the image data correcting device according to example embodiments may correct image data based on correction data that are obtained using a sampling window selected based on a luminance distribution of the display device among a plurality of sampling windows, thereby performing optimal or desired mura correction suitable for each display device.

Further, the image data correcting device and the display device including the image data correcting device according to example embodiments may correct image data based on correction data that are obtained using a plurality of sampling windows respectively at a plurality of reference gray levels, thereby performing optimal or desired mura correction suitable for a gray level of image data.

