WO2007097299A1

WO2007097299A1 - Image display and method for optimizing overdrive coefficient for image display

Info

Publication number: WO2007097299A1
Application number: PCT/JP2007/053023
Authority: WO
Inventors: Kengo Mori; Yutaka Arai
Original assignee: Nec Display Solutions, Ltd.
Priority date: 2006-02-20
Filing date: 2007-02-20
Publication date: 2007-08-30
Also published as: JP2007219392A; JP5255186B2

Abstract

An image display has a control section (16) which optimizes the over drive coefficient by enhancing the accuracy of the prediction of the temperature of the display panel (12) by using a temperature detecting section (14) such as a temperature sensor provided in the image display and a time monitoring section (15) for monitoring the operation elapsing time of the display panel. The image display measures the response speed for itself, thereby optimizes the overdrive coefficient for oneself, and displays a motion picture by overdrive adequate to the environment of the user over a long term.

Description

Specification

Image display device and method for optimizing overdrive coefficient in image display device

Technical field

The present invention relates to an image display device and an overdrive coefficient optimization method in the image display device, and more particularly to an LCD moving image display device that performs overdrive driving and an overdrive coefficient optimization method in the device.

This application claims priority based on Japanese Patent Application No. 2006-42461 filed in Japan on February 20, 2006, the contents of which are incorporated herein by reference.

Background art

In recent years, flat panel displays such as liquid crystal (LCD) displays have become widespread as image display devices.

In addition, with the high speed of PCs, the number of cases of handling video display on LCD has increased. Such LCD video display devices have become popular as television applications in general households as LCD panels have become larger and have improved image quality. The demand for is getting higher.

By the way, the above-mentioned LCD panel displays an image by changing the transmittance of each cell by changing the electric field applied to each cell (pixel) constituting the LCD panel. At this time, since the transmittance of the LCD cell changes relatively slowly, there is a problem with response speed, such as when the video is displayed, a part of the video of the previous frame overlaps with the video of the current frame and appears to be blurred. To do.

In order to improve the response speed described above, a general LCD panel employs a method of overdrive driving by applying a voltage higher than the normal voltage. For this purpose, a lookup table is used to obtain output data from the input data and the input data one frame before.

[0004] The response speed of the LCD panel is improved by the overdrive driving described above. However, the response speed is written in a look-up table that is highly temperature dependent. When the bar drive coefficient is fixed, when the temperature changes, the overdrive drive is not optimal, and the blurred edge of the screen is emphasized.

For this reason, the overdrive coefficient is adjusted according to changes in the ambient temperature, or multiple types of temperature-specific look-up tables are provided, and the most suitable look-up table is selected and switched. Many LCD displays that perform overdrive driving have been proposed (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

Patent Document 1: Japanese Patent Application Laid-Open No. 2003-241721 (paragraph “0022”, FIGS. 1 and 2)

Patent Document 2: Japanese Unexamined Patent Publication No. 2005-114955 (paragraph “0021”, FIG. 4)

Patent Document 3: Japanese Patent Application Laid-Open No. 2005-272882 (paragraph “0019”)

Disclosure of the invention

Problems to be solved by the invention

[0005] According to the techniques disclosed in Patent Documents 1 to 3 described above, an optimal overdrive coefficient can be obtained according to the ambient temperature of the LCD panel, so that improved image quality can be obtained.

However, there are various factors that cause temperature changes in the LCD panel, such as when the LCD monitor is used with its horizontal positioning force rotated vertically, or when the PC returns from hibernation. In addition, the temperature measured by a temperature sensor provided near the LCD panel does not necessarily become the temperature of the LCD panel. Therefore, how to accurately predict the LCD panel temperature and determine the overdrive coefficient was the most important design matter.

[0006] The overdrive coefficient is a fixed value or an adjustment value written when manufacturing an LCD panel or LCD display. Therefore, when the temperature characteristics of the LCD panel and the temperature characteristics inside the LCD display are changed over a long period of time after manufacture, even if such an overdrive coefficient is used, optimal overdrive driving cannot be achieved.

Therefore, in order to obtain the optimum overdrive coefficient during use, it is desirable to measure the response speed in the usage environment. However, this requires expensive measuring instruments and long hours of work. In terms of service and maintenance, the cost was high, and measurement in an actual usage environment was difficult. [0007] The present invention has been made based on the above various circumstances, and an image that realizes high-definition video display by accurately predicting the temperature of a display panel such as an LCD and determining an overdrive coefficient. A method for optimizing an overdrive coefficient in a display device and an image display device is provided.

The present invention also provides an image display device that realizes overdrive driving suitable for the use environment after manufacture by measuring the response speed of the display panel in the use environment and optimizing the overdrive coefficient. Also provided are methods for optimizing overdrive coefficients in image display devices.

Means for solving the problem

In order to solve the above-described problem, the image display device of the present invention has a look-up table for performing overdrive driving of a display panel based on an overdrive coefficient determined by the current frame image and the immediately preceding frame image. An overdrive drive unit, a temperature detection unit that detects the temperature of the display panel, a storage unit that stores a plurality of overdrive coefficients suitable for the detected temperature, and a recovery from a startup or hibernation state Stored in the storage unit using the time monitoring unit that monitors the operation elapsed time of the display panel, the temperature information acquired from the temperature detection unit, and the time monitoring unit force acquired operation elapsed time information. And a control unit that selects an overdrive coefficient and sets it in the lookup table.

[0009] In addition, the image display device of the present invention further includes an outside air temperature detection unit that detects outside air temperature to the outside, and the control unit acquires temperature information acquired from the temperature detection unit and the outside air temperature detection unit. The overdrive coefficient stored in the storage unit is selected using the difference from the outside air temperature information and the operation elapsed time information of the display panel acquired from the time monitoring unit, and set in the lookup table I prefer that.

[0010] Further, the image display device of the present invention further includes a rotation direction detection unit that detects a rotation direction in a use state of the display panel, and the control unit includes the temperature information acquired from the temperature detection unit, The overdrive coefficient stored in the storage unit is selected using the display panel operation elapsed time information acquired from the time monitoring unit and the rotation direction detection unit force acquired from the rotation direction information. Lookup tape Preferred to set to le.

[0011] In addition, the image display device of the present invention is provided on the front surface of the display panel, measures the brightness of the test pattern displayed on the display panel, and converts the voltage into a voltage to detect the response speed. A measurement unit; and a test video pattern generation unit that sequentially generates the test pattern of an arbitrary gradation under the control of the control unit and outputs the test pattern to the overdrive driving unit. In the response speed measurement mode of the display panel, the test pattern generation unit is activated to sequentially generate the test patterns, and the luminance level is taken from the response speed measurement unit to sequentially calculate the overdrive coefficient. It is preferable to set it in the lookup table.

[0012] The overdrive coefficient optimization method of the present invention is based on the overdrive coefficient determined by the current frame image and the immediately preceding frame image, and displays an image with a look-up table for overdriving the display panel. A method for optimizing an overdrive coefficient in an apparatus, comprising: detecting a temperature of the display panel; and monitoring an operation elapsed time of the display panel when the image display apparatus is recovered from a startup or hibernation state. And using the detected temperature information and the monitored operation elapsed time information, an overdrive coefficient suitable for the temperature stored in advance in a memory is selected, and the look-up table And a display panel based on the overdrive coefficient set in the look-up table. It has a step of performing overdrive driving of the.

[0013] In addition, the method for optimizing an overdrive coefficient according to the present invention includes the step of sequentially generating a test pattern of arbitrary gradation in the response speed measurement mode of the display panel and displaying the test pattern on the display panel; Measure the brightness level of the test pattern displayed on the panel, convert it to voltage and detect the response speed, and take the measured brightness level to calculate the overdrive coefficient sequentially and set it in the lookup table Preferably, the method further comprises:

The invention's effect

[0014] According to the present invention, since the overdrive coefficient can be determined by accurately predicting the temperature of the display panel, high-quality moving image display is possible. In addition, images under the usage environment

o

Since the display device measures the response speed of the display panel and optimizes the overdrive coefficient, it is possible to realize overdrive drive suitable for the use environment after manufacturing. Brief Description of Drawings

[015] FIG. 1 is a block diagram showing an internal configuration of an image display apparatus that is strongly involved in a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a data structure of a lookup table used in the first embodiment of the present invention.

FIG. 3 is a diagram for explaining a response time of overdrive driving of the image display device in the first embodiment of the present invention.

FIG. 4 is a flowchart showing the operation of the image display apparatus which is strongly involved in the first embodiment of the present invention.

FIG. 5 is a diagram showing temperature characteristics of the display panel 12 in the first embodiment of the present invention.

FIG. 6 is a block diagram showing an application example in the first embodiment of the present invention.

FIG. 7 is a block diagram showing another application example in the first embodiment of the present invention.

FIG. 8 is a block diagram showing an internal configuration of an image display apparatus that is strongly involved in a second embodiment of the present invention.

Explanation of symbols

70 Signal processor

11, 71 Overdrive drive

12, 72 Display panel

13, 73 Memory

14, 74 Temperature detector

15, 75 hours monitoring section

16, 76 Control unit

51 Outside temperature detector

61 Rotation direction detector

77 Test pattern generator

78 Response speed measurement unit 111 Norec Up Tape Nore

BEST MODE FOR CARRYING OUT THE INVENTION

[0017] (First embodiment)

FIG. 1 is a block diagram showing an internal configuration of an image display apparatus that is a substitute for the first embodiment of the present invention.

The image display apparatus according to the first embodiment of the present invention includes a signal processing unit 10, an overdrive drive unit 11, a display panel 12, a storage unit 13, a temperature detection unit 14, and a time monitoring unit 15. And the control unit 16.

[0018] The signal processing unit 10 executes processing for matching the input video signal with the display format of the display panel 12, and outputs the processed signal to the overdrive drive unit 11. The overdrive drive unit 11 performs overdrive drive of the display panel 12 based on the overdrive coefficient determined by the current frame image and the immediately preceding frame image. The overdrive drive unit 11 also includes a lookup table 111 in which an overdrive coefficient is set.

Here, the display panel 12 is an LCD panel that displays an image by changing the transmittance of each cell by changing the electric field applied to each cell (pixel).

[0019] The storage unit 13 stores a plurality of overdrive coefficients suitable for the temperature detected by the temperature detection unit 14. The temperature detection unit 14 detects the temperature near the display panel 12 using a temperature sensor or the like and outputs the detected temperature to the control unit 16. Further, the time monitoring unit 15 monitors the operation elapsed time of the display panel 12 when the PC activation or hibernation state power is restored, and outputs it to the control unit 16.

The control unit 16 uses the temperature information acquired from the temperature detection unit 14 and the operation elapsed time information acquired from the time monitoring unit 15 to use the intermediate force optimum overdrive stored in the storage unit 13. Select a coefficient and output it to the overdrive drive unit 11. This overdrive coefficient is set in a look-up table 111 built in the overdrive drive unit 11. Specifically, the control unit 16 is configured by a microcomputer or the like, and realizes the above-described functions by sequentially reading and executing a program recorded in a built-in ROM. In the above configuration, the video signal la output from the PC is input to the signal processing unit 10 in the image display device, where processing such as color conversion and image enlargement is performed. The video signal output as a result of processing is input to the overdrive drive unit 11.

The overdrive drive unit 11 determines the video signal by referring to the lookup table 111 based on the video signal output to the display panel 12 in the immediately previous frame and the video signal of the current frame. This video signal is output to the display panel 12.

[0021] The look-up table 111 has, for example, the data structure shown in FIG. 2, and can arbitrarily select a video signal to be output this time from the immediately preceding frame (one frame before video) and the current frame (current video). It is possible to set. The overdrive drive unit 11 sets an overdrive coefficient so that a video signal emphasized over the video signal of the current frame is output in response to a change in the video signal whose response speed of the display panel 12 is slow. As a result, the display panel 12 performs the overdrive driving shown in FIG. By this driving, the response speed of the display panel 12 is improved.

Fig. 3 shows the response time of the overdrive drive of the image display device. When the overdrive drive is not performed for the video signal (a) from the PC, the response time and overdrive drive for the video signal in (b) In this case, the response time for the video signal in (c) is shown.

FIG. 4 is a flowchart showing the operation of the control unit 16. Hereinafter, the overdrive optimization process by the control unit 16 will be described in detail with reference to the flowchart shown in FIG.

First, the control unit 16 acquires temperature information from the temperature detection unit 14 provided in the image display device (step S41). Subsequently, the acquired temperature information is compared with the previously measured temperature information to determine whether there is a change (step S42). Here, when it is determined that there is a change, the control unit 16 refers to the lookup table 111 in the overdrive drive unit 11 to determine an optimal overdrive coefficient reference destination (step S43). If there is no change, the overdrive optimization process ends.

The control unit 16 further determines whether or not the reference overdrive coefficient has already been set in the lookup table 111 (step S44). If the overdrive coefficient is set, the display panel 1 is displayed based on the temperature information acquired by the temperature detector 14. A temperature of 2 is predicted, and an appropriate overdrive coefficient is selected and read from the storage unit 13 holding a plurality of overdrive coefficients corresponding to the temperature (step S45). Next, the read overdrive coefficient is set in the look-up table 111 in the overdrive drive unit 11 to switch to the overdrive coefficient suitable for the temperature, and the overdrive optimization process is completed (step S46).

If it is determined in step S44 that the reference overdrive coefficient has already been set, the overdrive optimization process described above ends.

[0024] The above description is a force that is a basic configuration for well-known optimization of overdrive. As described above, the response speed of the display panel 12 is highly temperature dependent. Changes with panel 12 operating time.

That is, referring to FIG. 5 showing the temperature characteristics of the display panel 12, the display panel 12 rapidly increases in temperature immediately after startup (power-on), and rapidly decreases after power-off. The same temperature change occurs when the PC to which the display panel 12 is connected goes into hibernation (power off) and returns from hibernation (restart) while the display panel 12 is in use. .

[0025] In order to grasp the temperature of the display panel 12, it is desirable to provide the temperature detection unit 14 such as a temperature sensor directly on the display panel 12, but there is a technical problem in terms of manufacturing. Cost. Therefore, the temperature detection unit 14 is generally provided on a control board or the like located in the vicinity of the display panel 12, and predicts the temperature of the display panel 12 from indirectly measured temperature information.

However, the temperature indirectly measured in this way does not necessarily match the actual display panel 12, and is not accurate as temperature information for optimizing the overdrive coefficient. As shown in Fig. 5, the temperature rise when power is turned on or resumed from PC hibernation depends on the elapsed time of operation such as power off or PC hibernation. A means for this is needed.

In the first embodiment of the present invention, a time monitoring unit 15 is provided as means for monitoring the operation elapsed time information. The control unit 16 obtains these times from the time monitoring unit 15 when performing the power activation Z off and the PC hibernation state Z recovery. As a result, the control unit 1 6 is capable of predicting the temperature of the display panel 12 from the temperature information acquired from the temperature detection unit 14 and the time information acquired from the time monitoring unit 15 when selecting the overdrive coefficient.

Specifically, in the process of step S44 of the flowchart shown in FIG. 4, the control unit 16 displays the elapsed operation time information when the start or hibernation state power is restored in addition to the temperature information. Get from. Further, the control unit 16 selects an optimum overdrive coefficient among the plurality of overdrive coefficients stored in the storage unit 13 by using the temperature information and the elapsed time information in the processes of steps S45 and S46. , Set in lookup table 111.

FIG. 6 shows an application example of the image display device according to the first embodiment of the present invention. Referring to FIG. 6, in this application example, in addition to the configuration shown in FIG. 1, an outside air temperature detector 51 that also has a temperature sensor and the like for measuring the outside air temperature is added to the outside of the image display device. Yes. The control unit 16 predicts the temperature of the display panel 12 from the difference between the temperature (outside air temperature) in the usage environment of the image display device and the temperature on the control board by the temperature detection unit 14. This makes it easier to predict the exact temperature of the display panel 12. In addition, the control unit 16 can further improve the temperature prediction accuracy of the display panel 12 by further referring to the operation elapsed time information from the time monitoring unit 15, and can obtain an optimal overdrive coefficient. High-quality video display can be realized even when the PC sleep state power is restored. In FIG. 6, the configuration other than the outside air temperature detection unit 51 is the same as the configuration shown in FIG. .

FIG. 7 shows another application example of the image display device according to the first embodiment of the present invention. In this application example, a rotation direction detector 61 is added to the image display device shown in FIG.

The temperature change of the display panel 12 further depends on the use state of the image display device in addition to the operation elapsed time described above. Some image display devices can be used by rotating the display panel 12 with a mechanical part as a fulcrum, and switching to a vertical position, a horizontal position, or vice versa. In such an image display device, for example, the display panel 12 is When used in a vertically placed state, the temperature characteristics of the display panel 12 differ depending on whether they are used horizontally or vertically because the position of the display panel 12 changes with the components that generate heat. In addition, the temperature detected by the temperature detection unit 14 also has different measurement results for the same reason, and thus the temperature information output from the temperature detection unit 14 needs to be corrected.

In the application example shown in FIG. 7, in addition to the configuration shown in FIG. 1, in order to detect the rotation direction of the image display device (display panel 12) described above, a rotation direction detection unit 61 that also has a microswitch force is provided. Is added. For this reason, the control unit 16 can always acquire the rotation state of the image display device from the rotation direction detection unit 61. When selecting the overdrive coefficient, the control unit 16 uses the temperature information acquired from the temperature detection unit 14, the time information acquired from the time monitoring unit 15, and the rotation state information of the image display device. Twelve temperatures can be predicted more accurately. Furthermore, if the outside air temperature information obtained from the outside air temperature detector 51 in the application example shown in FIG. 6 is also added as a parameter, the temperature prediction accuracy of the display panel 12 can be further improved, and the use state of the image display device High-quality video display can be realized by selecting the most suitable overdrive coefficient for the camera.

In FIG. 7, the configuration other than the rotation direction detection unit 61 is the same as the configuration shown in FIG.

[0030] According to the first embodiment of the present invention described above, various temperature change factors are grasped with respect to the response speed of the display panel 12 having temperature dependence, and the temperature information is corrected to perform overload. The drive coefficient can be optimized and the response speed of the display panel 12 can be improved. As a result, it is possible to realize an image display device equipped with an overdrive function for displaying stable high-quality moving images.

[0031] (Second Embodiment)

FIG. 8 is a block diagram showing an internal configuration of an image display apparatus which is a substitute for the second embodiment of the present invention.

In FIG. 8, the signal processing unit 70, the overdrive drive unit 71, the display panel 72, the storage unit 73, the temperature detection unit 74, and the time monitoring unit 75 are the signal processing unit of the first embodiment shown in FIG. 10, Overdrive drive unit 11, Display panel 12, Storage unit 13, Temperature detection unit 14, Since it is the same as that of each of the time monitoring units 15, the configuration and operation description here are omitted.

In the second embodiment, a test pattern generation unit 77 and a response speed detection unit 78 are further added to the above configuration, and the control unit 76 adds the test pattern generation unit 77 and the response speed detection unit 78. Use to calculate and optimize overdrive coefficients. The details will be described below.

[0032] The control unit 76 can display a video signal on the display panel 72 using the test pattern generation unit 77, and as an example, can generate a video signal of 0 to 255 gradations. The response speed measurement unit 78 is provided on the front surface of the display panel 72, converts the measured luminance value into a voltage value, and outputs the voltage value to the control unit 76. Thereby, the control unit 76 can take in the luminance level information from the voltage value.

[0033] When entering the mode for measuring the response speed of the display panel 72, the control unit 76 uses the test pattern generation unit 77 to transmit the video signal to the display panel 72 even if the input video signal is empty. Can be output. In order to measure the response speed of the display panel 72, the control unit 76 instructs the test pattern generation unit 77 to output a 0-gradation video signal first, and uses the response speed measurement unit 78 to change the luminance level. Start sampling and import. Subsequently, a video signal of one gradation is output from the test pattern generation unit 77, and the luminance level is sampled and captured by the response speed measurement unit 78.

Next, the control unit 76 changes the overdrive coefficient of 0-1 in the lookup table 711 to sample the luminance level at the time of gradation change, and repeats this operation until the luminance level stabilization time is shortened. The coefficient when the stabilization time is shortened is the optimum coefficient for 0-1 gradation change.

[0034] Similarly, 0—2, 0—3,..., 0—255 times, the above operation is repeatedly measured and the overdrive coefficient is calculated. Overdrive coefficient can be optimized by combining 0 to 255 video.

Similarly, the temperature information obtained from the temperature detector 74 is calculated by calculating the optimal total overdrive coefficient when the image of the current frame is changed from 0 to 255 while changing the image of the previous frame from 1 to 255. And the time information acquired from the time monitoring unit 75. The overdrive coefficient is stored in the storage unit 73. Note that if the previous frame and the current frame are the same, there is no need to overdrive, so measurement is omitted.

[0035] According to the second embodiment of the present invention described above, even after the image display device is manufactured, the image display device itself that does not generate an expensive measuring instrument, service, and maintenance costs is displayed on the display panel. 72 response speeds can be measured to optimize the overdrive factor. As a result, an overdrive drive suitable for the characteristics of the display panel 72, the ambient temperature, and the usage environment can be realized, so that an image display device having an overdrive function for displaying high-quality moving images over a long period of time can be realized.

[0036] As described above, the present invention includes temperature detection means (temperature detection units 14, 74) such as temperature sensors provided inside and outside, and means for monitoring the operation elapsed time of the display panel (time monitoring unit 15, 75), the overdrive coefficient can be optimized by accurately predicting the temperature of the display panel. The overdrive coefficient is also optimized by having a means (response speed measurement unit 78) for measuring the response speed of the image display device itself. Therefore, it is possible to display a moving image by overdrive suitable for the user's environment for a long time, and to realize a liquid crystal display with high-quality moving image display quality and reliability.

Industrial applicability

[0037] The image display device of the present invention and the method for optimizing the overdrive coefficient in the image display device are particularly suitable for use in LCD moving image display that performs overdrive driving, and accurately predicts the temperature of the display panel. Since the overdrive coefficient can be determined, high-quality video display is possible. In the present invention, the image display device measures the response speed of the display panel according to the use environment and optimizes the overdrive coefficient, thereby realizing overdrive driving suitable for the use environment after manufacture. be able to.

Claims

The scope of the claims

[1] An overdrive drive unit having a look-up table for overdrive driving the display panel based on an overdrive coefficient determined by the current frame image and the immediately preceding frame image;

A temperature detector for detecting the temperature of the display panel;

A storage unit that stores a plurality of overdrive coefficients suitable for the detected temperature, a time monitoring unit that monitors the elapsed operation time of the display panel when the startup or hibernation state power is restored,

A control unit that selects the overdrive coefficient stored in the storage unit using the temperature information acquired from the temperature detection unit and the operation elapsed time information acquired from the time monitoring unit, and sets the overdrive coefficient in the lookup table; ,

An image display device comprising:

[2] It further includes an outside air temperature detecting unit for detecting outside air temperature outside.

The control unit uses a difference between temperature information acquired from the temperature detection unit and outside air temperature information acquired from the outside air temperature detection unit, and operation elapsed time information of the display panel acquired from the time monitoring unit. 2. The image display device according to claim 1, wherein an overdrive coefficient stored in the storage unit is selected and set in the lookup table.

[3] A rotation direction detection unit that detects a rotation direction in the usage state of the display panel is further provided,

The control unit includes temperature information acquired from the temperature detection unit, operation elapsed time information of the display panel acquired from the time monitoring unit, and rotation direction information of the display panel acquired from the rotation direction detection unit. The image display device according to claim 1, wherein an overdrive coefficient stored in the storage unit is selected using and set in the lookup table.

[4] A response speed measurement unit that is provided on the front surface of the display panel and detects the response speed by converting the luminance of the test pattern displayed on the display panel into a voltage;

A test pattern generation unit that sequentially generates the test pattern of arbitrary gradation and outputs the test pattern to the overdrive drive unit; The control unit activates the test pattern generation unit when measuring the response speed of the display panel and sequentially generates the test pattern, and takes in the luminance level from the response speed measurement unit and sequentially calculates the overdrive coefficient. The image display device according to claim 1, wherein the image display device calculates and sets the lookup table.

[5] A method for optimizing an overdrive coefficient in an image display device having a look-up table for performing overdrive driving of a display panel based on an overdrive coefficient determined by a current frame image and an immediately preceding frame image,

Detecting the temperature of the display panel;

Monitoring the elapsed time of operation of the display panel when the image display device is restored from a startup or hibernation state;

Using the detected temperature information and the monitored operation elapsed time information, selecting an overdrive coefficient suitable for the temperature stored in a memory and setting it in the lookup table;

Performing overdrive driving of the display panel based on the overdrive coefficient set in the lookup table;

Method for optimizing overdrive coefficient in image display apparatus having

[6] In the response speed measurement mode of the display panel, a step of sequentially generating a test pattern of arbitrary gradation and displaying it on the display panel;

Measuring the brightness level of the test pattern displayed on the display panel, converting it to voltage and detecting the response speed;

Taking the measured luminance level and calculating the overdrive coefficient sequentially and setting it in the look-up table;

The method for optimizing an overdrive coefficient in the image display device according to claim 5, further comprising: