METHOD OF PERFORMING A MULTI-TIME PROGRAMMABLE OPERATION, AND ORGANIC LIGHT EMITTING DISPLAY DEVICE EMPLOYING THE SAME

A method of performing a multi-time programmable (MTP) operation includes independently setting respective pixel gamma curves for respective pixel circuits, obtaining respective actual gamma curves, the obtaining of the respective actual gamma curves including performing tests based on the respective pixel gamma curves for the respective pixel circuits, and storing respective gamma offsets, the storing of the respective gamma offsets including comparing the respective actual gamma curves with a reference gamma curve for the respective pixel circuits.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1is a flow chart illustrating a method of performing a multi-time programmable (MTP) operation according to example embodiments.FIG. 2is a diagram illustrating an example in which an MTP operation is performed on respective pixel circuits included in a display panel by a method illustrated inFIG. 1.FIG. 3is a graph illustrating an example in which an MTP operation is performed on respective pixel circuits based on a plurality of gamma curves by a method illustrated inFIG. 1.

Referring to the example embodiment shown inFIGS. 1 through 3, the method illustrated inFIG. 1may independently set respective pixel gamma curves for respective pixel circuits11(operation S120), may obtain respective actual gamma curves, which may include performing tests based on the respective pixel gamma curves for the respective pixel circuits11(operation S140), and may store respective gamma offsets, which may include comparing the respective actual gamma curves with a reference gamma curve RGMC for the respective pixel circuits11(operation S160). In the present example embodiment, the respective pixel gamma curves indicate respective gamma curves that are selected by the respective pixel circuits11among a plurality of gamma curves in order to perform an MTP operation. In addition, the respective actual gamma curves indicate respective gamma curves that are obtained by performing tests on the respective pixel circuits11based on the respective pixel gamma curves. Further, the reference gamma curve RGMC indicates a gamma curve (e.g., GAMMA CURVE 2.2) that is set for displaying (i.e., outputting) an image in an organic light emitting display device.

Generally, an MTP operation for repeatedly performing a post-correction in luminance and color coordinate for the respective pixel circuits11of a display panel10is performed in order to adjust an image quality of the organic light emitting display device to reach a target quality level. To this end, the method illustrated inFIG. 1may independently set the respective pixel gamma curves for the respective pixel circuits11(operation S120). Thus, the method illustrated inFIG. 1may select one of first through (n)th gamma curves PGMC_1through PGMC_n, where n is an integer greater than or equal to 2, as the respective pixel gamma curves for the respective pixel circuits11. In the present example embodiment, the first through (n)th gamma curves PGMC_1through PGMC_n correspond to candidates for the respective pixel gamma curves retained by the respective pixel circuits11in order to perform the MTP operation. For example, a first pixel circuit11may select (e.g., retain) the first gamma curve PGMC_1as its pixel gamma curve, a second pixel circuit11may select the (n)th gamma curve PGMC_n as its pixel gamma curve, and a third pixel circuit11may select the first gamma curve PGMC_1as its pixel gamma curve. Meanwhile, a quantity of the first through (n)th gamma curves PGMC_1through PGMC_n may correspond to the number of cases related to MTP offsets. In addition, the first through (n)th gamma curves PGMC_1through PGMC_n may be stored in gamma registers (e.g., referred to as gamma rooms) of a MTP memory device.

In an example embodiment, the respective pixel circuits11may include a red color pixel circuit (i.e., a pixel circuit representing a red color), a green color pixel circuit (i.e., a pixel circuit representing a green color), and a blue color pixel circuit (i.e., a pixel circuit representing a blue color). In this case, the method illustrated inFIG. 1may obtain respective temporary gamma curves by performing tests based on the reference gamma curve RGMC for the respective pixel circuits11, may calculate a red color MTP offset, a green color MTP offset, and a blue color MTP offset by comparing the respective temporary gamma curves with the reference gamma curve RGMC for the respective pixel circuits11, and may select one of first through eighth gamma curves as the respective pixel gamma curves based on the red color MTP offset, the green color MTP offset, and the blue color MTP offset for the respective pixel circuits11. In the present example embodiment, the respective temporary gamma curves indicate respective gamma curves that are obtained by performing tests based on the reference gamma curve RGMC for the respective pixel circuits11. As described above, a quantity of the first through (n)th gamma curves PGMC_1through PGMC_n may correspond to the number of cases related to MTP offsets. For example, when the MTP offsets include the red color MTP offset, the green color MTP offset, and the blue color MTP offset, the red color MTP offset may have a plus-value (i.e., +) or a minus-value (i.e., −) with respect to the reference gamma curve RGMC, the green color MTP offset may have a plus-value or a minus-value with respect to the reference gamma curve RGMC, and the blue color MTP offset may have a plus-value or a minus-value with respect to the reference gamma curve RGMC. Thus, a quantity of the first through (n)th gamma curves PGMC_1through PGMC_n may be 8 (i.e., 2*2*2=8). Thus, an integer n may be 8. In example embodiments, the respective temporary gamma curves may be obtained by performing tests at predetermined reference gray-levels (e.g., 35 gray-level, 87 gray-level, and 171 gray-level) based on the reference gamma curve RGMC for the respective pixel circuits11.

In another example embodiment, the respective pixel circuits11may include a red color pixel circuit (i.e., a pixel circuit representing a red color), a green color pixel circuit (i.e., a pixel circuit representing a green color), a blue color pixel circuit (i.e., a pixel circuit representing a blue color), and a white color pixel circuit (i.e., a pixel circuit representing a white color). In this case, the method illustrated inFIG. 1may obtain respective temporary gamma curves by performing tests based on the reference gamma curve RGMC for the respective pixel circuits11, may calculate a red color MTP offset, a green color MTP offset, a blue color MTP offset, and a white color MTP offset by comparing the respective temporary gamma curves with the reference gamma curve RGMC for the respective pixel circuits11, and may select one of first through sixteenth gamma curves as the respective pixel gamma curves based on the red color MTP offset, the green color MTP offset, the blue color MTP offset, and the white color MTP offset for the respective pixel circuits11. As described above, a quantity of the first through (n)th gamma curves PGMC_1through PGMC_n may correspond to the number of cases related to MTP offsets. For example, when the MTP offsets include the red color MTP offset, the green color MTP offset, the blue color MTP offset, and the white color MTP offset, the red color MTP offset may have a plus-value or a minus-value with respect to the reference gamma curve RGMC, the green color MTP offset may have a plus-value or a minus-value with respect to the reference gamma curve RGMC, the blue color MTP offset may have a plus-value or a minus-value with respect to the reference gamma curve RGMC, and the white color MTP offset may have a plus-value or a minus-value with respect to the reference gamma curve RGMC. Thus, a quantity of the first through (n)th gamma curves PGMC_1through PGMC_n may be 16 (i.e., 2*2*2*2=16). Thus, an integer n may be 16. In example embodiments, the respective temporary gamma curves may be obtained by performing tests at the predetermined reference gray-levels (e.g., 35 gray-level, 87 gray-level, and 171 gray-level) based on the reference gamma curve RGMC for the respective pixel circuits11.

Next, the method illustrated inFIG. 1may obtain the respective actual gamma curves by performing tests based on the respective pixel gamma curves for the respective pixel circuits11(operation S140). In the present example embodiment, the respective actual gamma curves may be different from the respective pixel gamma curves for the respective pixel circuits11because deviations may occur in a manufacturing process when the organic light emitting display device is manufactured. In example embodiments, the respective actual gamma curves may be obtained by performing tests at predetermined reference gray-levels (e.g., 35 gray-level, 87 gray-level, and 171 gray-level) based on the respective pixel gamma curves for the respective pixel circuits11. As the respective actual gamma curves for the respective pixel circuits11are obtained, the method illustrated inFIG. 1may store the respective gamma offsets by comparing the respective actual gamma curves with the reference gamma curve RGMC for the respective pixel circuits11(operation S160). In the present example embodiment, the respective gamma offsets may be stored by comparing the respective actual gamma curves with the reference gamma curve RGMC at the predetermined reference gray-levels (e.g., 35 gray-level, 87 gray-level, and 171 gray-level) for the respective pixel circuits11. Since these are examples, a way of storing the respective gamma offsets is not limited thereto. Meanwhile, the method illustrated inFIG. 1may store respective setting offsets by comparing the respective pixel gamma curves with the reference gamma curve RGMC for the respective pixel circuits11. Similarly, the respective setting offsets may be stored by comparing the respective pixel gamma curves with the reference gamma curve RGMC at the predetermined reference gray-levels (e.g., 35 gray-level, 87 gray-level, and 171 gray-level) for the respective pixel circuits11. Since these are examples, a way of storing the respective setting offsets is not limited thereto. In example embodiments, the respective gamma offsets and the respective setting offsets may be stored in the MTP memory device included in a driving integrated circuit (D-IC).

As described above, the method illustrated inFIG. 1may perform the MTP operation in a wide range by independently setting the respective pixel gamma curves (i.e. selecting one of the first through (n)th gamma curves PGMC_1through PGMC_n as the respective pixel gamma curves) for the respective pixel circuits, by generating the respective actual gamma curves based on the respective pixel gamma curves for the respective pixel circuits11, and by comparing the respective actual gamma curves with the reference gamma curve RGMC to store the respective gamma offsets for the respective pixel circuits11. In other words, since a general method performs the MTP operation based on a fixed pixel gamma curve for the respective pixel circuits11, the MTP operation may not be performed if the respective gamma offsets has a value out of a predetermined range (e.g., 8 bits (−127˜128)). On the other hand, since the method illustrated inFIG. 1performs the MTP operation based on the respective pixel gamma curves, where the respective pixel gamma curves are independently set for the respective pixel circuits11, for the respective pixel circuits11, the MTP operation may be performed regardless of a gamma offset range. As described above, the respective setting offsets between the respective pixel gamma curves and the reference gamma curve RGMC and the respective gamma offsets between the respective actual gamma curves and the reference gamma curve RGMC may be stored in the offset registers (e.g., referred to as the offset rooms) of the MTP memory device. Therefore, a data signal may be adjusted based on the respective gamma offsets and the respective setting offsets stored in the offset registers of the MTP memory device for the respective pixel circuits11.

FIG. 4is a flow chart illustrating an example in which respective pixel gamma curves are independently set for respective pixel circuits by a method illustrated inFIG. 1.FIG. 5is a diagram illustrating an example in which respective pixel gamma curves are independently set for respective pixel circuits by a method illustrated inFIG. 1.

In the example embodiment show inFIGS. 4 and 5, it is illustrated that the respective pixel gamma curves are independently set for the respective pixel circuits11by the method illustrated inFIG. 1when the respective pixel circuits11include a red color pixel circuit, a green color pixel circuit, and a blue color pixel circuit. Specifically, the method illustrated inFIG. 4may obtain respective temporary gamma curves by performing tests based on a reference gamma curve RGMC for the respective pixel circuits11(operation S220), may calculate a red color MTP offset R, a green color MTP offset G, and a blue color MTP offset B by comparing the respective temporary gamma curves with the reference gamma curve RGMC for the respective pixel circuits11(operation S240), and may select one of first through eighth gamma curves PGMC_1through PGMC_8as the respective pixel gamma curves based on the red color MTP offset R, the green color MTP offset G, and the blue color MTP offset B for the respective pixel circuits11(operation S260). In example embodiments, the respective temporary gamma curves may be obtained by performing tests at predetermined reference gray-levels based on the reference gamma curve RGMC for the respective pixel circuits11.

As illustrated inFIG. 5, the MTP offsets may include the red color MTP offset R, the green color MTP offset G, and the blue color MTP offset B. Thus, the red color MTP offset R may have a plus-value or a minus-value with respect to the reference gamma curve RGMC, the green color MTP offset G may have a plus-value or a minus-value with respect to the reference gamma curve RGMC, and the blue color MTP offset B may have a plus-value or a minus-value with respect to the reference gamma curve RGMC. Thus, one of the first through eighth gamma curves may be selected as the respective pixel gamma curves based on the red color MTP offset R, the green color MTP offset G, and the blue color MTP offset B for the respective pixel circuits11. For example, one of the first through eighth gamma curves may be selected as the respective pixel gamma curves for the respective pixel circuits11using Table 1 below.

In the present example embodiment, PGC denotes the pixel gamma curve, and GC1through GC8denote the first through eighth gamma curves to be selected as the pixel gamma curve. Meanwhile, a quantity of the first through eighth gamma curves may correspond to the number of cases related to the MTP offsets. Thus, a quantity of the first through eighth gamma curves may be 8 (i.e., 2*2*2=8) because the red color MTP offset R has a plus-value or a minus-value with respect to the reference gamma curve RGMC, the green color MTP offset G has a plus-value or a minus-value with respect to the reference gamma curve RGMC, and the blue color MTP offset B has a plus-value or a minus-value with respect to the reference gamma curve RGMC. As described above, the method illustrated inFIG. 1may independently set the respective pixel gamma curves (i.e., may select one of the first through eighth gamma curves as the respective pixel gamma curves) based on the red color MTP offset R, the green color MTP offset G, and the blue color MTP offset B for the respective pixel circuits11when the respective pixel circuits11include the red color pixel circuit, the green color pixel circuit, and the blue color pixel circuit. In example embodiments, the first through eighth gamma curves may be stored in gamma registers (i.e., referred to as gamma rooms) of an MTP memory device. Next, the method illustrated inFIG. 1may generate the respective actual gamma curves based on the respective pixel gamma curves for the respective pixel circuits11, and may store the respective gamma offsets by comparing the respective actual gamma curves with the reference gamma curve RGMC for the respective pixel circuits11. As a result, the method illustrated inFIG. 1may perform the MTP operation in a wide range.

FIG. 6is a flow chart illustrating another example in which respective pixel gamma curves are independently set for respective pixel circuits by the method illustrated inFIG. 1.FIG. 7is a diagram illustrating another example in which respective pixel gamma curves are independently set for respective pixel circuits by the method illustrated inFIG. 1.

Referring toFIGS. 6 and 7, it is illustrated that the respective pixel gamma curves are independently set for the respective pixel circuits11by the method illustrated inFIG. 1when the respective pixel circuits11include a red color pixel circuit, a green color pixel circuit, a blue color pixel circuit, and a white color pixel circuit. Specifically, the method illustrated inFIG. 1may obtain respective temporary gamma curves by performing tests based on a reference gamma curve RGMC for the respective pixel circuits11(operation S320), may calculate a red color MTP offset R, a green color MTP offset G, a blue color MTP offset B, and a white color MTP offset W by comparing the respective temporary gamma curves with the reference gamma curve RGMC for the respective pixel circuits11(operation S340), and may select one of first through sixteenth gamma curves PGMC_1through PGMC_16as the respective pixel gamma curves based on the red color MTP offset R, the green color MTP offset G, the blue color MTP offset B, and the white color MTP offset W for the respective pixel circuits11(operation S360). In example embodiments, the respective temporary gamma curves may be obtained by performing tests at predetermined reference gray-levels based on the reference gamma curve RGMC for the respective pixel circuits11.

As illustrated inFIG. 7, the MTP offsets may include the red color MTP offset R, the green color MTP offset G, the blue color MTP offset B, and the white color MTP offset W. Thus, the red color MTP offset R may have a plus-value or a minus-value with respect to the reference gamma curve RGMC, the green color MTP offset G may have a plus-value or a minus-value with respect to the reference gamma curve RGMC, the blue color MTP offset B may have a plus-value or a minus-value with respect to the reference gamma curve RGMC, and the white color MTP offset W may have a plus-value or a minus-value with respect to the reference gamma curve RGMC. Thus, one of the first through sixteenth gamma curves may be selected as the respective pixel gamma curves based on the red color MTP offset R, the green color MTP offset G, the blue color MTP offset B, and the white color MTP offset W for the respective pixel circuits11. Meanwhile, a quantity of the first through sixteenth gamma curves may correspond to the number of cases related to the MTP offsets. Thus, a quantity of the first through sixteenth gamma curves may be 16 (i.e., 2*2*2*2=16) because the red color MTP offset R has a plus-value or a minus-value with respect to the reference gamma curve RGMC, the green color MTP offset G has a plus-value or a minus-value with respect to the reference gamma curve RGMC, the blue color MTP offset B has a plus-value or a minus-value with respect to the reference gamma curve RGMC, and the white color MTP offset W has a plus-value or a minus-value with respect to the reference gamma curve RGMC. As described above, the method illustrated inFIG. 1may independently set the respective pixel gamma curves (i.e., may select one of the first through sixteenth gamma curves as the respective pixel gamma curves) based on the red color MTP offset R, the green color MTP offset G, the blue color MTP offset B, and the white color MTP offset W for the respective pixel circuits11when the respective pixel circuits11include the red color pixel circuit, the green color pixel circuit, the blue color pixel circuit, and the white color pixel circuit. In example embodiments, the first through sixteenth gamma curves may be stored in gamma registers (i.e., referred to as gamma rooms) of an MTP memory device. Next, the method illustrated inFIG. 1may generate the respective actual gamma curves based on the respective pixel gamma curves for the respective pixel circuits11, and may store the respective gamma offsets by comparing the respective actual gamma curves with the reference gamma curve RGMC for the respective pixel circuits11. As a result, the method illustrated inFIG. 1may perform the MTP operation in a wide range.

FIG. 8is a block diagram illustrating an organic light emitting display device according to example embodiments.FIG. 9is a block diagram illustrating an MTP processing unit included in an organic light emitting display device ofFIG. 8.

In the example embodiment shown inFIGS. 8 and 9, the organic light emitting display device100may include a display panel110, a scan driving unit120, a data driving unit130, a power unit140, an MTP processing unit150, and a timing control unit160. For example, the organic light emitting display device100may employ a sequential emission driving technique.

The display panel100may include pixel circuits111. The display panel110may be coupled to the scan driving unit120via scan-lines SL1through SLn, and may be coupled to the data driving unit130via data-lines DL1through DLm. In the present example embodiment, the display panel110may include n*m pixel circuits111because the pixel circuits are arranged at locations corresponding to crossing points of the scan-lines SL1through SLn and the data-lines DL1through DLm. In an example embodiment, the pixel circuits111may include red color pixel circuits, green color pixel circuits, and blue color pixel circuits. In another example embodiment, the pixel circuits111may include red color pixel circuits, green color pixel circuits, blue color pixel circuits, and white color pixel circuits. The scan driving unit120may provide a scan signal to the pixel circuits111via the scan-lines SL1through SLn. The data driving unit130may provide a data signal to the pixel circuits111via the data-lines DL1through DLm. The power unit140may provide a high power voltage ELVDD and a low power voltage ELVSS to the pixel circuits111via power-lines.

The MTP processing unit150may perform an MTP operation based on respective pixel gamma curves for respective pixel circuits111. In the present example embodiment, one of first through (n)th gamma curves, where n is an integer greater than or equal to 2, may be selected as the respective pixel gamma curves for the respective pixel circuits111. Specifically, the MTP processing unit150may independently set the respective pixel gamma curves for the respective pixel circuits111, may obtain respective actual gamma curves by performing tests based on the respective pixel gamma curves for the respective pixel circuits111, may store respective gamma offsets MGO by comparing the respective actual gamma curves with a reference gamma curve for the respective pixel circuits111, and may store respective setting offsets SGO by comparing the respective pixel gamma curves with the reference gamma curve for the respective pixel circuits111. Thus, when the organic light emitting display device100outputs an image, the MTP processing unit150may adjust the data signal (i.e., may convert an input data signal IN_DATA into an output data signal OUT_DATA) based on the respective gamma offsets MGO and the respective setting offsets SGO for the respective pixel circuits111. As illustrated inFIG. 9, the MTP processing unit150may include an MTP buffer device152, an MTP memory device154, and a data signal adjusting device156. Specifically, the MTP memory device154may receive data TD that are finally updated in the MTP buffer device152from the MTP buffer device152, and may store the data TD as the respective gamma offsets MGO and the respective setting offsets SGO for the respective pixel circuits111. In addition, the data signal adjusting device156may adjust the data signal based on the respective gamma offsets MGO and the respective setting offsets SGO for the respective pixel circuits111. Since a structure of the MTP processing unit150is an example, the structure of the MTP processing unit150may be designed in various ways.

In an example embodiment, the respective pixel circuits111may include the red color pixel circuit, the green color pixel circuit, and the blue color pixel circuit. In this case, the MTP processing unit150may obtain respective temporary gamma curves by performing tests based on a reference gamma curve for the respective pixel circuits111, may calculate a red color MTP offset, a green color MTP offset, and a blue color MTP offset by comparing the respective temporary gamma curves with the reference gamma curve for the respective pixel circuits111, and may select one of first through eighth gamma curves as the respective pixel gamma curves based on the red color MTP offset, the green color MTP offset, and the blue color MTP offset for the respective pixel circuits111. In another example embodiment, the respective pixel circuits111may include the red color pixel circuit, the green color pixel circuit, the blue color pixel circuit, and the white color pixel circuit. In this case, the MTP processing unit150may obtain respective temporary gamma curves by performing tests based on the reference gamma curve for the respective pixel circuits111, may calculate a red color MTP offset, a green color MTP offset, a blue color MTP offset, and a white color MTP offset by comparing the respective temporary gamma curves with the reference gamma curve for the respective pixel circuits111, and may select one of first through sixteenth gamma curves as the respective pixel gamma curves based on the red color MTP offset, the green color MTP offset, the blue color MTP offset, and the white color MTP offset for the respective pixel circuits111. Since these are described referring toFIGS. 1 through 7, the duplicated descriptions will be omitted.

Referring again toFIG. 8, the timing control unit160may control the scan driving unit120, the data driving unit130, the power unit140, and the MTP processing unit150based on the first through fourth control signals CTL1, CTL2, CTL3, and CTL4. Thus, the organic light emitting display device100may display (i.e., output) a high-quality image by performing the MTP operation in a wide range. In the present example embodiment, the organic light emitting display device100may perform the MTP operation in a wide range by independently setting the respective pixel gamma curves for the respective pixel circuits111, by generating the respective actual gamma curves based on the respective pixel gamma curves for the respective pixel circuits111, and by comparing the respective actual gamma curves with the reference gamma curve to store the respective gamma offsets MGO for the respective pixel circuits111. In an example embodiment, as illustrated inFIG. 8, the MTP processing unit150may be located outside the timing control unit160and the data driving unit130. In another example embodiment, the MTP processing unit150may be located inside the timing control unit160, or inside the data driving unit130.

FIG. 10is a block diagram illustrating an organic light emitting display device according to example embodiments.

In the example embodiment shown inFIG. 10, the organic light emitting display device200may include a display panel210, a scan driving unit220, a data driving unit230, a power unit240, an MTP processing unit250, a control signal generating unit255, and a timing control unit260. For example, the organic light emitting display device200may employ a simultaneous emission driving technique.

The display panel200may include pixel circuits211. The display panel210may be coupled to the scan driving unit220via scan-lines SL1through SLn, and may be coupled to the data driving unit230via data-lines DL1through DLm. In an example embodiment, the pixel circuits211may include red color pixel circuits, green color pixel circuits, and blue color pixel circuits. In another example embodiment, the pixel circuits211may include red color pixel circuits, green color pixel circuits, blue color pixel circuits, and white color pixel circuits. The scan driving unit220may provide a scan signal to the pixel circuits211via the scan-lines SL1through SLn. The data driving unit230may provide a data signal to the pixel circuits211via the data-lines DL1through DLm. The power unit240may provide a high power voltage ELVDD and a low power voltage ELVSS to the pixel circuits211via power-lines. The MTP processing unit250may perform an MTP operation based on respective pixel gamma curves for respective pixel circuits211. In the present example embodiment, one of first through (n)th gamma curves, where n is an integer greater than or equal to 2, may be selected as the respective pixel gamma curves for the respective pixel circuits211. In an example embodiment, as illustrated inFIG. 10, the MTP processing unit250may be located outside the timing control unit260and the data driving unit230. In another example embodiment, the MTP processing unit250may be located inside the timing control unit260, or inside the data driving unit230. The control signal generating unit255may provide an emission control signal ECS to the display panel210, where the emission control signal ECS controls the pixel circuits211of the display panel210to simultaneously emit light. The timing control unit260may control the scan driving unit220, the data driving unit230, the power unit240, the MTP processing unit250, and the control signal generating unit255based on first through fifth control signals CTL1, CTL2, CTL3, CTL4, and CTL5. Thus, the organic light emitting display device200may display (i.e., output) a high-quality image by performing the MTP operation in a wide range. In the present example embodiment, the organic light emitting display device200may perform the MTP operation in a wide range by independently setting the respective pixel gamma curves for the respective pixel circuits211, by generating the respective actual gamma curves based on the respective pixel gamma curves for the respective pixel circuits211, and by comparing the respective actual gamma curves with the reference gamma curve to store the respective gamma offsets for the respective pixel circuits211.

FIG. 11is a block diagram illustrating an electronic device having an organic light emitting display device according to example embodiments.FIG. 12is a diagram illustrating an example in which an electronic device illustrated inFIG. 11is implemented as a smart-phone.

In the example embodiment shown inFIGS. 11 and 12, the electronic device500may include a processor510, a memory device520, a storage device530, an input/output (I/O) device540, a power supply550, and an organic light emitting display device560. In the present example embodiment, the organic light emitting display device560may correspond to the organic light emitting display device100ofFIG. 8, or the organic light emitting display device200illustrated inFIG. 10. In addition, the electronic device500may further include a plurality of ports for communicating with a video card, a sound card, a memory card, a universal serial bus (USB) device, other electronic devices, etc. In an example embodiment, as illustrated inFIG. 12, the electronic device500may be implemented as the smart-phone. However, an implementation of the electronic device500is not limited thereto.

The processor510may perform various computing functions. The processor510may be a micro processor, a central processing unit (CPU), etc. The processor510may be coupled to other components via an address bus, a control bus, a data bus, etc. Further, the processor510may be coupled to an extended bus such as a peripheral component interconnection (PCI) bus. The memory device520may store data for operations of the electronic device500. For example, the memory device520may include at least one non-volatile memory device such as an erasable programmable read-only memory (EPROM) device, an electrically erasable programmable read-only memory (EEPROM) device, a flash memory device, a phase change random access memory (PRAM) device, a resistance random access memory (RRAM) device, a nano floating gate memory (NFGM) device, a polymer random access memory (PoRAM) device, a magnetic random access memory (MRAM) device, a ferroelectric random access memory (FRAM) device, etc., and/or at least one volatile memory device such as a dynamic random access memory (DRAM) device, a static random access memory (SRAM) device, a mobile DRAM device, etc. The storage device530may be a solid state drive (SSD) device, a hard disk drive (HDD) device, a CD-ROM device, etc.

The I/O device540may be an input device such as a keyboard, a keypad, a touchpad, a touch-screen, a mouse, etc., and an output device such as a printer, a speaker, etc. In some example embodiments, the organic light emitting display device560may be included in the I/O device540. The power supply550may provide a power for operations of the electronic device500. The organic light emitting display device560may communicate with other components via the buses or other communication links. In an example embodiment, the organic light emitting display device560may include a display panel, a scan driving unit, a data driving unit, a power unit, an MTP processing unit, and a timing control unit. In another example embodiment, the organic light emitting display device560may include a display panel, a scan driving unit, a data driving unit, a power unit, an MTP processing unit, a control signal generating unit, and a timing control unit. In the present example embodiment, the MTP processing unit may perform an MTP operation based on one of first through (n)th gamma curves (i.e., respective pixel gamma curves) for respective pixel circuits of the display panel. Specifically, the MTP processing unit may independently set the respective pixel gamma curves for the respective pixel circuits, may obtain respective actual gamma curves by performing tests based on the respective pixel gamma curves for the respective pixel circuits, may store respective gamma offsets by comparing the respective actual gamma curves with a reference gamma curve for the respective pixel circuits, and may store respective setting offsets by comparing the respective pixel gamma curves with the reference gamma curve for the respective pixel circuits. Although it is described above that example embodiments are applied to the organic light emitting display device, embodiments may also be applied to a liquid crystal display (LCD) device.

Embodiments may be applied to an electronic device having a display device. For example, embodiments may be applied to a television, a computer monitor, a laptop, a digital camera, a cellular phone, a smart phone, a smart pad, a personal digital assistant (PDA), a portable multimedia player (PMP), an MP3 player, a navigation system, a game console, a video phone, etc.

By way of summation and review, discarding all end products determined as defective products is not efficient. Thus, a post-correction for adjusting the image quality of the organic light emitting display device to reach the target quality level may be considered. An MTP operation for repeatedly performing the post-correction in luminance and color coordinate for respective pixel circuits may be performed in order to adjust the image quality of the organic light emitting display device to reach the target quality level. Generally, the MTP operation may be performed by comparing an actual gamma curve, where the actual gamma curve is generated based on a pixel gamma curve, with a reference gamma curve to store respective gamma offsets. For example, the reference gamma curve may correspond to the pixel gamma curve. In this case, the actual gamma curve may be compared with the pixel gamma curve to store the respective gamma offsets. However, since general driving integrated circuit (D-IC) includes fixed gamma registers, the MTP operation may be performed by generating an actual gamma curve based on a fixed pixel gamma curve for the respective pixel circuits, and by comparing the actual gamma curve with a reference gamma curve to store the respective gamma offsets. As a result, it may be difficult to perform the MTP operation in a wide range. For example, the MTP operation may not be performed if the respective gamma offsets has a value out of a predetermined range (e.g., 8 bits (−127˜128)).

As described above, embodiments may provide a method of performing a multi-time programmable (MTP) operation capable of performing the MTP operation in a wide range when the MTP operation is performed on respective pixel circuits. Embodiments may provide an organic light emitting display device employing the method of performing the MTP operation. A method of performing an MTP operation according to example embodiments may perform the MTP operation in a wide range by independently setting respective pixel gamma curves for respective pixel circuits, and by comparing respective actual gamma curves, where the respective actual gamma curves are generated based on the respective pixel gamma curves, with a reference gamma curve to store respective gamma offsets for respective pixel circuits. In addition, an organic light emitting display device according to example embodiments may display (i.e., output) a high-quality image by employing the method of performing the MTP operation.