KR20100047064A - Optical compensation apparatus and method for optical compensation using the same - Google Patents

Abstract

PURPOSE: An optical compensation apparatus and a method for optical compensation using the same are provided to set a resistor of a power supply unit to match the characteristics of a display panel. CONSTITUTION: A sensor unit(120) measures the luminance of a sub pixel. The sub pixel is arranged in the display panel(150). A processor unit(140) extracts the measured luminance of the sub pixel through the sensor unit. The processor unit corrects the current provided to the sub pixel. The processor unit sets the target luminance of the sub pixel. The processor unit compares the target luminance and the measured luminance and calculates luminance. The processor unit calculates current variation and produces a compensated current.

Description

Optical Compensation Apparatus and Method for Optical Compensation using the same}

An embodiment of the present invention relates to an optical compensation device and an optical compensation method using the same.

An organic light emitting display device used in an organic light emitting display device is a self-light emitting device in which a light emitting layer is formed between two electrodes positioned on a substrate.

The organic light emitting display includes a top emission type, a bottom emission type, or a dual emission type according to a direction in which light is emitted. According to the driving method, it is divided into a passive matrix type and an active matrix type.

When the scan signal, the data signal, and the voltage are supplied to the plurality of subpixels arranged in a matrix form on the panel, the organic light emitting display device may display an image by emitting light of the selected subpixel.

The subpixels arranged on the display panel receive a scan signal from a scan driver connected to the scan line, a data signal from a data driver connected to the data line, and a current from a power source connected to the power line. The power supply unit may supply different currents for each of the red, green, and blue subpixels. Each sub-pixel may vary in brightness depending on a current supplied from a power supply unit. Here, the current supplied to each sub-pixel is determined by the register value stored in the register memory section of the power supply section. By the way, in the conventional organic light emitting display device, all the register values set in the register memory unit are the same. If the same register value is applied to all the products in this way, the luminance or color coordinate deviation occurs due to the deviation of the emission of the organic light emitting layer, the characteristic variation of the TFT constituting the display panel, and the output variation of the power supply. There must be a plan for this.

An embodiment of the present invention for solving the above problems of the background art is to provide an optical compensation device that can set the register value of the power supply unit according to the characteristics of the display panel and an optical correction method using the same.

According to the above-described problem solving means, an embodiment of the present invention, the sensor unit for measuring the brightness of the sub-pixel disposed on the display panel; And a processor unit which measures the luminance of the subpixel through the sensor unit, extracts the measured luminance, and corrects a current supplied to the subpixel so that the measured luminance is close to a target luminance set therein. Set the target luminance, set the first current value to be supplied to the subpixel, supply the first current value to the subpixel, measure the luminance of the subpixel, extract the first measured luminance, and compare the target luminance to the first measured luminance. The first luminance value is calculated, the second current value is calculated by comparing the first current value with a representative expression set therein, the second current value is supplied to the subpixel, and the luminance of the subpixel is measured to extract the second measured luminance. The second luminance value is calculated by comparing the target luminance with the luminance of the second measured value, and the slope equation is derived using the second current value and the second measured value luminance. And calculating a correction value current by calculating a current change amount in a gradient equation.

The representative equation may be an expression derived based on an average value of luminance versus current supplied to the plurality of display panels.

The processor unit may convert the calculated correction value current into a register value corresponding to the correction value current and store the converted correction value in a register memory unit that is interlocked with a power supply unit that supplies power to the display panel.

The processor unit may automatically store the register value in the register memory unit of the power supply unit.

The optical compensator may include an analog-to-digital converter that converts the luminance value of the analog signal measured by the sensor unit into the luminance value of the digital signal and transfers the luminance value to the processor unit.

The optical calibrating device may further include a communication device to monitor a process of calibrating in an external device.

The optical correction device may perform correction for each of the red, green, and blue subpixels.

On the other hand, an embodiment of the present invention, the step of setting the target luminance of the sub-pixel to be corrected among the plurality of sub-pixels disposed on the display panel and setting a first current value to be supplied to the sub-pixel; Supplying a first current value to a subpixel; Measuring the luminance of the subpixel to extract the first measured luminance; Calculating a first luminance value by comparing the target luminance with the first measured luminance; Calculating a second current value by comparing the first current value with a representative formula set therein; Supplying a second current value to a sub pixel; Measuring the luminance of the subpixel to extract a second measured luminance; Calculating a second luminance value by comparing the target luminance with the second measured luminance; And deriving a gradient equation using the second current value and the second measured value luminance and calculating a current change amount in the gradient equation to calculate a correction value current.

The representative formula may be a formula derived based on an average value of luminance versus current supplied to the plurality of display panels.

After the calculating of the correction value current, the method may further include converting the correction value current into a register value corresponding to the correction value current and storing the correction value current in a register memory unit interoperating with a power supply unit supplying power to the display panel.

An embodiment of the present invention has an effect of providing an optical compensation device that can set the register value of the power supply unit according to the characteristics of the display panel and an optical correction method using the same. In addition, the embodiment of the present invention can set the register value of the power supply unit in accordance with the characteristics of the display panel, there is an effect that can solve the problem of luminance or color coordinate deviation caused by the output unit output deviation.

Hereinafter, with reference to the accompanying drawings, the specific content for the practice of the present invention will be described.

1 is a view for explaining an optical compensation device according to an embodiment of the present invention.

Referring to FIG. 1, an optical compensation apparatus according to an exemplary embodiment of the present invention includes a sensor unit 120 for measuring the luminance of a subpixel disposed on the display panel 150, and a luminance of the subpixel through the sensor unit 120. The processor unit 140 may extract the measured value luminance to correct the current supplied to the subpixel such that the measured value luminance is close to the target luminance set therein.

The display panel 150 may include a plurality of sub pixels arranged in a matrix. The plurality of subpixels disposed in the display panel 150 may include red, green, and blue, but is not limited thereto.

The sensor unit 120 may include a color sensor that can measure the luminance of the subpixels disposed on the display panel 150. The luminance measured through the sensor unit 120 may be transmitted to the processor unit 140.

The processor unit 150 may set a target luminance of the subpixel to be corrected, set a first current value to be supplied to the subpixel, and supply the first current value to the subpixel. The first luminance may be extracted by measuring the luminance of the subpixel, and the first luminance may be calculated by comparing the target luminance and the first luminance. The second current value may be calculated by comparing the first current value with a representative formula set therein, and the second current value may be supplied to the subpixel. The second luminance may be extracted by measuring the luminance of the subpixel, and the second luminance value may be calculated by comparing the target luminance and the second luminance. The gradient equation may be derived using the second current value and the luminance of the second measured value, and the correction value current may be calculated by calculating the change amount of the current in the gradient equation.

Here, the representative expression set in the processor 150 may be an expression derived based on an average value of luminance versus current supplied to the plurality of display panels. That is, the representative expression is an expression obtained by repeated experiments as an average index of the luminance change with respect to the current to determine the range of characteristic deviation for each display panel.

The processor 140 may input a signal to the driving IC 160 to display a desired pattern on the display panel 150. The processor unit 140 may convert the calculated correction value current into a register value corresponding to the correction value current and store it in the register memory unit 185 that is linked to the power supply unit 180 that supplies power to the display panel 150. The processor unit 140 may automatically store the converted register value in the register memory unit 185 linked with the power supply unit 180. The power supply unit 180 and the register memory unit 185 may be located on the flexible substrate 170 that is connected to the display panel 150, but is not limited thereto.

The optical compensation device may include an analog-to-digital converter 130 that converts the luminance value of the analog signal measured by the sensor unit 120 into the luminance value of the digital signal and transfers the luminance value to the processor unit. The analog to digital converter 130 may be located inside or outside the processor unit 140.

On the other hand, the optical compensation device may further include a communication device to monitor the process of correction in the external device. When the optical compensation device further includes a communication device, the communication device may be connected to an external device, for example, a computer or the like by serial or parallel communication. In this case, it is possible to monitor the correction process performed by the processor unit 140 through the computer.

Using the optical compensation device as described above, the red, green, and blue subpixels can be calibrated. The organic light emitting display device to be subjected to the correction for each of the red, green, and blue subpixels corresponds to a driving method requiring a different current for each of the red, green, and blue subpixels, for example, a digital drive.

Hereinafter, an organic light emitting display device employing a digital driving method will be described with reference to FIGS. 2 and 3.

FIG. 2 is a schematic diagram of an organic light emitting display device, FIG. 3 is a diagram illustrating a circuit configuration of a subpixel driven by a digital driving method, and FIG. 4 is a diagram illustrating a method of implementing grayscales using a digital driving method. to be.

Referring to FIG. 2, the organic light emitting display device includes a display panel 150 having a display area AA in which a plurality of subpixels P is positioned, and a driving IC 160 supplying driving signals to the display panel 150. ) And a power supply unit 180.

The driving IC 160 may include a scan driver 163 for supplying a scan signal to the display panel 150 and a data driver 167 for supplying a data signal to the display panel 150.

The scan driver 163 may receive a vertical synchronization signal Vsync from an external source and generate a scan signal and a control signal to be supplied to the plurality of subpixels P with reference to the vertical synchronization signal Vsync. To this end, the scan driver 163 may include a shift register 161 receiving a vertical synchronization signal Vsync, a level shifter 162 for adjusting a level of a signal received from the shift register 161, and a level shifter 162. An output buffer 164 for outputting a signal received from the) may be included, but is not limited thereto. The output buffer 164 of the scan driver 163 is connected to the scan wiring.

The data driver 167 may receive the horizontal sync signal Hsync and the image signals R, G, and B from the outside, and generate a data signal with reference to the horizontal sync signal Hsync. To this end, the data driver 167 stores the image data signals R, G, and B with reference to the shift register 166 supplied with the horizontal sync signal Hsync and the signal received from the shift register 166. The latch 168 and an output buffer 169 converting the signal and the image data signals R, G, and B received from the latch 168 into analog (or digital) and outputting the same may be included, but are not limited thereto. . The output buffer 169 of the data driver 167 is connected to the data wiring.

The power supply unit 180 supplies different currents for each of the subpixels disposed in the display panel 150. This is because the emission characteristics of the red, green, and blue subpixels disposed in the display panel 150 are different. The power supply unit 180 generates a current corresponding to a register value set in the register memory unit 185 to supply different currents to the corresponding subpixels.

Meanwhile, in the exemplary embodiment of the present invention, the driving IC 160 includes the scan driver 163 and the data driver 167, but the scan driver 163 and the data driver 167 are respectively located separately. Can be.

Referring to FIG. 3, the subpixel may include a first transistor STFT1, a second transistor STFT2, a capacitor CST, a driving transistor DTFT, and an organic light emitting diode OLED.

The first transistor STFT1 has a gate connected to the first scan line SCAN1, one end connected to the data line DATA, and the other end connected to the node A (A). The second transistor STFT2 has a gate connected to the second scan line SCAN2, one end of which is connected to the first power line VDD, and the other end of the second transistor STFT2 connected to the node A (A). One end of the capacitor CST is connected to the first power line VDD and the other end thereof is connected to the node A (A). The driving transistor DTFT has a gate connected to the node A (A), one end of which is connected to the first power line VDD, and the other end of which is connected to the first electrode of the organic light emitting diode OLED. In the organic light emitting diode OLED, a first electrode is connected to the other end of the driving transistor DTFT and a second electrode is connected to the second power supply line VSS.

The subpixel illustrated in FIG. 3 may be driven in the following form.

When the first scan signal is supplied through the first scan line SCAN1, the first transistor STFT1 is turned on and transfers the data signal supplied through the data line DATA to the capacitor CST. Next, the capacitor CST stores the data signal supplied through the data line DATA as a data voltage. Next, the driving transistor DTFT is turned on by the data voltage stored in the capacitor CST, and the organic light emitting diode OLED emits light. In the case of the digital driving method, when the subpixel is operated in this manner, when the second scan signal is supplied through the second scan wiring SCAN2, the capacitor CST is initialized, and the driving transistor DTFT is turned off and organic. Light emission of the light emitting diode OLED is stopped.

Referring to FIG. 4, in the above-described driving method, a section in which the first scan signal is supplied may be defined as an address section, a section in which the organic light emitting diode emits light may be defined as a light emitting section, and light emission of the organic light emitting diode may be The stopping section can be defined as the erasing section.

The digital driving method may be divided into subfield units to implement various gray levels. As described above, the divided subfields may include a light emitting section, an address section, and an erasing section. The light emitting section is a section for realizing grayscales according to time, an address section is a section for selecting a subpixel to emit light, and an erasing section is a section for stopping light emission.

When displaying an image with 64 gradations in the digital driving method, a frame period (16.67 ms) corresponding to 1/60 second may be divided into six subfields SF1 to SF6. Each of the six subfields SF1 to SF6 may include an address section, a light emitting section, and an erasing section.

On the other hand, the light emission period is a period for determining the gray scale weight in each subfield. For example, the gray scale weight of each subfield is 2 ⁿ by setting the gray scale weight of the first subfield SF1 to 2 ⁰ and the gray scale weight of the second subfield to 2 ¹ , where n = The gray scale weight of each subfield may be determined to increase at a ratio of 0, 1, 2, 3, 4, 5).

As such, by adjusting the light emission holding time in the light emitting period of each subfield according to the gray scale weight in the light emitting period of each subfield, it is possible to realize the grayscale of various images. However, in the exemplary embodiment of the present invention, only one frame is composed of six subfields in order to help the understanding of the description. However, the number of subfields forming one frame may be variously changed. Further, although the subfields are arranged in the order of increasing magnitude of the gray scale weight in one frame, the subfields may be arranged in the order of decreasing gray scale weight in one frame, or they may be related to the gray weight. Subfields may be arranged without.

Hereinafter, an optical correction method using the optical correction device will be described.

5 is a flowchart of an optical compensation method using an optical compensation device.

An optical correction method using an optical correction device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5.

First, in operation S10, a target brightness of a subpixel to be corrected among a plurality of subpixels disposed on the display panel 150 is set and a first current value to be supplied to the subpixel is set. In this step, when the target luminance of the subpixel to be corrected among red, blue, and green is set, the processor unit 140 converts the first current value into a register value and stores it in the register memory unit 185.

Next, a step (S12) of supplying a first current value to the subpixel is performed. In this step, the processor 140 controls the driving IC 160 to supply the scan signal and the data signal to the corresponding sub pixel in addition to the first current value.

In operation S14, the luminance of the subpixel is measured to extract the first measurement luminance. In this step, the processor unit 140 measures the luminance of the sub-pixel to be corrected by driving the sensor unit 120 and receives the first measured luminance measured by the sensor unit 120 to obtain the first measured luminance. Extract.

Next, a step (S16) of calculating a first luminance value by comparing the target luminance with the first measured luminance is performed. In this step, the processor unit 140 compares the previously set target luminance with the first measured luminance and calculates the first luminance value.

In operation S18, a second current value is calculated by comparing the first current value with a representative formula set therein. In this step, the processor unit 140 compares the first current value stored in the register memory unit 185 with the representative expression set therein, and then changes the luminance and the representative expression of the first current value supplied to the corresponding subpixel. The difference in luminance change can be found. The difference between the first current value and the representative equation may determine how much the second current value is adjacent to the target luminance. As described above, the representative expression set in the processor unit 150 may be an expression derived based on an average value of luminance versus current supplied to the plurality of display panels. That is, the representative expression is an expression obtained by repeated experiments as an average index of the luminance change with respect to the current to determine the range of characteristic deviation for each display panel.

In operation S20, a second current value is supplied to the subpixel. In this step, the processor unit 140 erases the register value corresponding to the first current value stored in the register memory unit 185, stores the register value corresponding to the second current value in the register memory unit 185, and then stores the second value. A current is generated with a register value corresponding to the current value and supplied to the subpixel. Here, the processor 140 controls the driving IC 160 to supply the scan signal and the data signal to the corresponding sub pixel in addition to the second current value.

In operation S22, the luminance of the subpixel is measured to extract the second measurement luminance. In this step, the processor unit 140 drives the sensor unit 120 again to measure the luminance of the subpixel to be corrected, and receives the second measured luminance measured by the sensor unit 120 to obtain the second measured luminance. Extract.

In operation S24, a second luminance value is calculated by comparing the target luminance with the second measured luminance. In this step, the processor unit 140 compares the previously set target luminance with the second measured luminance and calculates the second luminance value.

Next, a slope equation is derived using the second current value and the second measured value luminance, and a current value of the slope is calculated to calculate a correction value current (S26). In this step, the processor unit 140 derives a gradient equation suitable for the corresponding subpixel by using the second current value and the second measured value luminance calculated above, and calculates a correction value current.

Hereinafter, an example of the optical correction method described above will be described with reference to FIG. 6.

6 is an exemplary view of an optical correction method.

In the example of the optical correction method illustrated in FIG. 6, the actual inclination is the inclination to be obtained by the optical compensation method according to the embodiment, and the representative inclination is the inclination by the representative equation set in the processor unit 140. That is, in the example, it is assumed that the inclination of the subpixel to be corrected is lower than the inclination of the current versus the luminance represented by the representative expression set in the processor 140.

First, the target luminance set in the processor 140 is set to "720", and the first current value I1 to be supplied to the subpixel is set to "62" and is supplied to the subpixel (S10 and S12).

Next, the first measured luminance is extracted from the subpixels (S14). The first measured luminance of the subpixel measured by the sensor unit 120 is found to be "340". (I.e., when the current is supplied 62 for that sub-pixel, the luminance is 340.) (S14)

Next, when the target luminance "720" and the first measured luminance "340" are compared, the first luminance value, which is the luminance difference therebetween, is found to be "380" (S16).

Next, the second current value I2 is calculated by comparing the first current value I1 with the representative equation. (S18) Here, it is assumed that the representative equation set inside the processor unit 140 is “Y = 3X”. Is a target value luminance, " 3 " is a gradient constant, and " X " represents a correction value current. When the representative expression is the same as above, since "X = 720/3", the current value I2 by the representative expression is "240". Here, the second current value ΔI can be calculated by using the difference between the first current value I1 and the current value I2 according to the representative formula. Accordingly, it can be seen that the second current value ΔI becomes “178” since the first current value I1-current value I2 = 240-62 becomes.

Next, the second current value? I is supplied to the subpixels, and the second measured value luminance is extracted from the subpixels. (S20 and S22) The second current value? I is supplied to "178". In this case, the second measured value luminance DELTA S2, which is a change amount of the luminance according to this, is represented by "360".

Next, when the target luminance "720" and the second measured luminance "ΔS2" "360" are compared, the second luminance value, which is the difference in luminance between them, is found to be "360" (S24).

Next, a slope equation is derived using the second current value? I and the second measured value luminance? S2, and a correction value current is calculated. (S26) In this step, the second current value? I When the second measurement luminance DELTA S2, which is the change amount of luminance at 178 ", is" 360 ", it is understood that the gradient constant is not" 3 "for the corresponding subpixel. That is, it can be seen that the slope constant is the second measured value luminance DELTA S2 / second current value DELTA I = 360/178 = 2.02. Therefore, when the second current value ΔI and the second measured luminance ΔS2 are used, it is understood that the gradient expression “Y = 2.02 X” should be applied to the corresponding subpixel, not the representative expression set therein. Will be. Here, since the target value luminance "720 = 2.02 X", it can be seen that the correction value current "X" becomes "720 / 2.02 = 356.4".

After the correction value current calculating step S26 as described above, the correction value current is converted into a register value corresponding to the correction value current and automatically stored in the register memory unit 185 of the power supply unit 180 that supplies power to the display panel 150. . However, since the register value input corresponding to the correction value current must be input in integer units, the correction value current is stored as a value corresponding to "356".

Embodiments of the present invention have an effect of providing an optical compensation device capable of setting a register value of a power supply unit according to characteristics of a display panel and an optical compensation method using the same. In addition, the embodiment of the present invention can set the register value of the power supply unit in accordance with the characteristics of the display panel, there is an effect that can solve the problem of luminance or color coordinate deviation caused by the output unit output deviation.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention described above may be modified in other specific forms by those skilled in the art to which the present invention pertains without changing its technical spirit or essential features. It will be appreciated that it may be practiced. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all aspects. In addition, the scope of the present invention is shown by the claims below, rather than the above detailed description. Also, it is to be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention.

1 is a view for explaining an optical correction device according to an embodiment of the present invention.

2 is a schematic configuration diagram of an organic light emitting display device.

3 is an exemplary circuit configuration of a subpixel driven by a digital driving method.

FIG. 4 is a diagram for describing a method of implementing digital driving grayscale; FIG.

5 is a flowchart of an optical correction method using an optical correction device.

6 is an exemplary view of an optical correction method.

<Explanation of symbols on main parts of the drawings>

120: sensor unit 130: analog to digital conversion unit

140: processor unit 150: display panel

160: drive IC 170: flexible substrate

180: power supply unit 185: register memory unit

Claims (10)

A sensor unit for measuring the luminance of the sub-pixels disposed on the display panel; And And a processor unit configured to measure the luminance of the subpixel through the sensor unit, extract a measured luminance, and correct a current supplied to the subpixel such that the measured luminance is close to a target luminance set therein. The processor unit, Set a target luminance of the subpixel to be corrected, set a first current value to be supplied to the subpixel, supply the first current value to the subpixel, measure the luminance of the subpixel, and extract the first measured luminance. Comparing the target luminance with the first measured luminance, a first luminance value is calculated, a second current value is calculated by comparing the first current value with a representative expression set therein, and the second current value is converted into the sub-pixels. Supplying and measuring the luminance of the sub-pixel to extract a second measured luminance, and comparing the target luminance and the second measured luminance to calculate a second luminance value and using the second current value and the second measured luminance And a correction value current is calculated by deriving a slope equation and calculating a current change amount in the slope equation. The method of claim 1, The representative expression is, And an expression derived based on an average value of luminance versus current supplied to a plurality of display panels. The method of claim 1, The processor unit, And converting the calculated correction value current into a register value corresponding to the correction value current, and storing the correction value current in a register memory unit interlocked with a power supply unit supplying power to the display panel. The method of claim 3, The processor unit, And the register value is automatically stored in a register memory section of the power supply section. The method of claim 1, The optical correction device, And an analog-to-digital converter for converting the luminance value of the analog signal measured by the sensor unit into the luminance value of the digital signal and transmitting the same to the processor unit. The method of claim 1, The optical correction device, The optical correction device further comprises a communication device to monitor the process of the correction in the external device. The method of claim 1, The optical correction device, An optical compensator for performing red, green and blue subpixel correction. Setting a target luminance of a subpixel to be corrected among a plurality of subpixels arranged on the display panel and setting a first current value to be supplied to the subpixel; Supplying the first current value to the subpixel; Measuring a luminance of the subpixel to extract a first measured luminance; Calculating a first luminance value by comparing the target luminance with the first measured luminance; Calculating a second current value by comparing the first current value with a representative formula set therein; Supplying the second current value to the sub pixel; Measuring a luminance of the subpixel to extract a second measured luminance; Calculating a second luminance value by comparing the target luminance with the second measured luminance; And Deriving a gradient equation using the second current value and the luminance of the second measured value, and calculating a current of a correction value by calculating a current change amount in the gradient equation. The method of claim 8, The representative expression is, An optical correction method using an optical correction device, characterized in that the expression derived based on the average value of the luminance compared to the current supplied to the plurality of display panels. The method of claim 8, After the correction value current calculating step, And converting the corrected value current into a register value corresponding to the corrected value current and storing the corrected value current in a register memory unit interlocked with a power supply unit supplying power to the display panel.

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