WO2019163485A1

WO2019163485A1 - Display device, method for driving display device, and electronic equipment

Info

Publication number: WO2019163485A1
Application number: PCT/JP2019/003667
Authority: WO
Inventors: 山田　泰弘
Original assignee: ソニーセミコンダクタソリューションズ株式会社
Priority date: 2018-02-23
Filing date: 2019-02-01
Publication date: 2019-08-29
Also published as: CN111727471B; CN111727471A

Abstract

A display device according to the present invention comprises: a difference detection unit for detecting a difference in driving voltage between two adjacent pixels; a correction amount calculation unit for calculating a correction amount for correcting a driving voltage applied to a pixel to be corrected that generates a luminance change due to the difference in driving voltage detected by the difference detection unit; a correction amount adjustment unit for adjusting the correction amount calculated by the correction amount calculation unit in accordance with the quality of an output image; and a driving voltage correction unit for correcting the driving voltage applied to the pixel to be corrected on the basis of the correction amount adjusted by the correction amount adjustment unit.

Description

Display device, display device driving method, and electronic apparatus

The present disclosure relates to a display device, a display device driving method, and an electronic device.

In a display device such as a liquid crystal display device, a so-called lateral electric field is generated at a signal boundary portion where a potential difference occurs between video signals supplied to each pixel, that is, between two adjacent pixels. Due to this lateral electric field, the electric field applied to the electrodes of each pixel is disturbed, and an image quality defect occurs due to the influence of the disturbance of the electric field. As a feature of this phenomenon of image quality failure, the density of the two pixels varies depending on the difference (voltage difference) in the drive voltage based on the video signal between the two pixels.

Conventionally, with respect to the image quality defect caused by the horizontal electric field between two adjacent pixels, conventionally, a correction target pixel that detects a difference in driving voltage between two adjacent pixels and causes a luminance change due to the difference. A correction amount for correcting the driving voltage is calculated, and the driving voltage of the correction target pixel is corrected based on the correction amount (see, for example, Patent Document 1).

JP 2009-237366 A

In the prior art described in Patent Document 1, the correction amount of the drive voltage of the correction target pixel is set as a fixed value assuming the state of the display device after a certain change with time. For this reason, in the initial state where there is no change over time, the image quality deteriorates due to overcorrection, or in the state where the change over time progresses more than the assumed state, the image quality of the output image deteriorates due to insufficient correction.

The present disclosure relates to a display device and a display device driving method capable of improving the image quality of an output image by correcting the drive voltage of a correction target pixel without being affected by changes over time, and the display An object is to provide an electronic apparatus having the device.

In order to achieve the above object, a display device of the present disclosure is provided.
A difference detection unit for detecting a difference in driving voltage between two adjacent pixels;
A correction amount calculation unit that calculates a correction amount for correcting the drive voltage of the correction target pixel that causes a luminance change due to a difference in drive voltage detected by the difference detection unit;
A correction amount adjusting unit that adjusts the correction amount calculated by the correction amount calculating unit according to the image quality of the output image; and
A drive voltage correction unit is provided that corrects the drive voltage of the correction target pixel based on the correction amount adjusted by the correction amount adjustment unit.

Further, a driving method of the display device of the present disclosure for achieving the above-described object is as follows.
A difference detection step of detecting a difference in drive voltage between two adjacent pixels;
A correction amount calculation step for calculating a correction amount for correcting the drive voltage of the correction target pixel that causes a luminance change due to the difference in the drive voltage detected in the difference detection step;
A correction amount adjusting step for adjusting the correction amount calculated in the correction amount calculating step according to the image quality of the output image; and
Each process of the drive voltage correction step for correcting the drive voltage of the correction target pixel is executed based on the correction amount adjusted in the correction amount adjustment step.

In addition, an electronic device of the present disclosure for achieving the above object is
A difference detection unit for detecting a difference in driving voltage between two adjacent pixels;
A correction amount calculation unit that calculates a correction amount for correcting the drive voltage of the correction target pixel that causes a luminance change due to a difference in drive voltage detected by the difference detection unit;
A correction amount adjusting unit that adjusts the correction amount calculated by the correction amount calculating unit according to the image quality of the output image; and
A drive voltage correction unit that corrects the drive voltage of the correction target pixel based on the correction amount adjusted by the correction amount adjustment unit;
A display device;

FIG. 1 is a block diagram illustrating an outline of a system configuration of a liquid crystal display device to which the technology of the present disclosure is applied. 2A is a block diagram illustrating an example of a configuration of an active matrix liquid crystal panel, and FIG. 2B is an equivalent circuit diagram illustrating an example of a circuit configuration of a pixel. FIG. 3A is an exploded perspective view showing an example of the structure of the liquid crystal panel, and FIG. 3B is an enlarged view of a main part of FIG. 3A. FIG. 4A is a diagram showing the moisture state of the liquid crystal layer in the initial state of the liquid crystal panel, FIG. 4B is a diagram showing an example of the pixel potential in the initial state, and FIG. 4C is the video signal V _sig in the initial state. -Is a diagram showing the characteristics of transmittance T. FIG. 5A is a diagram showing the moisture state of the liquid crystal layer in the moisture absorption state of the liquid crystal panel, FIG. 5B is a diagram showing an example of the pixel potential in the moisture absorption state, and FIG. 5C is the video signal V _sig in the moisture absorption state. -Is a diagram showing the characteristics of transmittance T. FIG. 6 is a block diagram illustrating an example of a configuration of a digital signal processing unit according to an embodiment of the present disclosure. FIG. 7 is a block diagram illustrating an example of a configuration of a voltage difference calculation unit between adjacent pixels in the digital signal processing unit. FIG. 8 is a block diagram illustrating an example of the configuration of the correction amount calculation unit in the digital signal processing unit. FIG. 9 is a diagram showing drive voltage levels for a display image based on an input video signal and an image of the center line thereof. FIG. 10A is a diagram showing a display image after image quality failure occurs, FIG. 10B is a diagram showing a voltage difference signal obtained by taking a voltage difference between the own pixel and the N + 1th pixel, and FIG. It is a figure which shows the voltage difference signal which took the voltage difference with the N-1 pixel. FIG. 11 is a diagram illustrating an example of the correction setting information referred to when the correction amount is calculated. FIG. 12 is a diagram illustrating an example in which the image quality state of the output image is directly detected by the imaging unit arranged in the projector. FIG. 13 is a flowchart illustrating a flow of processing for correction amount adjustment in the correction amount adjustment unit according to the first embodiment. FIG. 14 is a diagram illustrating an example of the relationship between the usage time of the liquid crystal panel, the state of the output image quality, and the correction coefficient α. FIG. 15 is an explanatory diagram of the threshold value and the image quality setting range for determining whether or not the drive voltage of the correction target pixel needs to be corrected. FIG. 16 is a diagram illustrating an example of correction setting information after feedback of the correction coefficient α. FIG. 17 is a flowchart illustrating a flow of a process for adjusting the correction amount in the correction amount adjusting unit according to the second embodiment. FIG. 18 is a diagram illustrating an example of the relationship between the usage time of the liquid crystal panel, the state of the output image quality, and the correction setting table. FIG. 19 is a diagram illustrating an example of numerical values in the correction setting table A and the correction setting table B. FIG. 20 is a flowchart illustrating a flow of processing for adjusting the correction amount in the correction amount adjusting unit according to the third embodiment. FIG. 21 is a configuration diagram illustrating an outline of an optical system of a three-plate projection type liquid crystal display device (projector) which is an example of the electronic apparatus of the present disclosure.

Hereinafter, modes for carrying out the technology of the present disclosure (hereinafter referred to as “embodiments”) will be described in detail with reference to the drawings. The technology of the present disclosure is not limited to the embodiments, and various numerical values in the embodiments are examples. In the following description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted. The description will be given in the following order.
1. 1. Description of display device and display device driving method of the present disclosure, and electronic device in general 2. Display device to which technology of present disclosure is applied 2-1. System configuration example 2-2. Configuration example of liquid crystal panel 2-3. Pixel circuit example 2-4. Structure example of liquid crystal panel 2-5. 2. Change in image quality over time due to leak between pixels Embodiment of the present disclosure (digital signal processing unit)
3-1. Adjacent pixel voltage difference calculation unit 3-2. Correction amount calculation unit 3-3. Correction amount adding unit 3-3-1. Example 1 (Example of detecting the state of image quality from the imaging result of an output image)
3-3-2. Example 2 (Modification of Example 1)
3-3-3. Example 3 (Example of detecting the state of image quality from the usage time of a liquid crystal panel)
4). Modification 5 Electronic device of the present disclosure (example of projection type liquid crystal display device)
6). Configurations that can be taken by the present disclosure

<Description of Display Device of the Present Disclosure, Display Device Driving Method, and Electronic Device>
In the display device, the display device driving method, and the electronic apparatus according to the present disclosure, the correction amount adjustment unit captures an adjustment image for adjusting the correction amount, and the captured image data is used for the image quality of the output image. It can be set as the structure used as a parameter which detects a state.

In the display device, the display device driving method, and the electronic apparatus of the present disclosure including the above-described preferable configuration, the image quality data is digitized based on the captured image data obtained by capturing the adjustment image for the correction amount adjustment unit. A correction coefficient is set based on the image quality data, corrected image quality data that reflects the correction coefficient is calculated, and the drive voltage of the correction target pixel needs to be corrected based on the corrected image quality data obtained by this calculation. It can be set as the structure which judges NO. At this time, it is preferable to determine whether or not correction is necessary by comparing the corrected image quality data obtained by calculation with the reference image quality data.

Alternatively, in the display device, the display device driving method, and the electronic apparatus including the preferred configuration described above, the correction amount adjustment unit outputs the image quality data based on the captured image data obtained by capturing the adjusted image. It is digitized, a correction coefficient is set based on the image quality data, and the adjustment image is corrected and output using the correction coefficient. Then, the image quality data is digitized based on the captured image data obtained by capturing the corrected adjustment image, and the necessity of correcting the drive voltage of the correction target pixel is determined based on the digitized image quality data of the corrected adjustment image. It can be set as the structure to judge. At this time, it is preferable to determine whether or not correction is necessary by comparing the digitized image quality data of the adjusted image with the reference image quality data.

Alternatively, in the display device, the display device driving method, and the electronic apparatus including the preferred configuration described above, the usage time of the display panel in which the pixels are arranged is counted for the correction amount adjustment unit. The count value can be used as a parameter for detecting the image quality state of the output image. Further, the correction amount adjustment unit has a plurality of correction setting tables corresponding to the usage time of the display panel, and selects one of the plurality of correction setting tables based on the count value of the usage time of the display panel. It can be configured.

Further, in the display device, the display device driving method, and the electronic apparatus including the preferred configuration described above, the corrected image quality data that reflects the selected correction setting table is calculated for the correction amount adjustment unit. In addition, it is possible to determine whether or not it is necessary to correct the drive voltage of the correction target pixel based on the corrected image quality data obtained by this calculation. At this time, it is preferable to determine whether or not correction is necessary by comparing the corrected image quality data obtained by calculation with the reference image quality data.

Furthermore, in the display device, the display device driving method, and the electronic apparatus of the present disclosure including the above-described preferable configuration, the correction amount adjustment unit is configured to have a temperature, humidity, or temperature under the usage environment of the display panel. It can be configured to use humidity as one of the parameters. Alternatively, the display panel chromaticity measured using a chromaticity meter or the luminance of the display panel measured using a luminance meter can be used as one of the parameters.

<Display device to which the technology of the present disclosure is applied>
First, a display device to which the technology of the present disclosure is applied will be described using a liquid crystal display device as an example.

Liquid crystal display devices are classified into a transmission type, a reflection type, and a semi-transmission type for display methods. In a transmissive liquid crystal display device, amorphous silicon (amorphous semiconductor) or polysilicon (polycrystalline semiconductor) is often used as a silicon material used for a thin film transistor (TFT: Thin Film Transistor) used in a pixel. In reflective liquid crystal display devices, single crystal silicon is often used. Polysilicon is high-temperature polysilicon (HTPS: High-Temperature-Poly-Silicon) that forms a thin film in a high-temperature environment of 1000 degrees Celsius or higher, and low-temperature polysilicon that forms a thin film in a low-temperature environment of 600 degrees Celsius or lower. (LTPS: Low Temperature Poly-Silicon).

In a liquid crystal panel (display panel), a substrate such as a quartz substrate, a glass substrate, or a silicon substrate is used as a substrate on which pixels are formed. In general, glass substrates are used for amorphous silicon-transmissive liquid crystal panels and low-temperature polysilicon-transmissive liquid crystal panels, and quartz substrates are used for high-temperature polysilicon-transmissive liquid crystal panels. Single-crystal silicon-reflective liquid crystal panels Then, a silicon substrate is used.

Liquid crystal materials mainly used for product manufacture include TN mode, VA mode, and IPS mode, and TFT processes include high temperature polysilicon, low temperature polysilicon, and amorphous silicon (a-Si). In a liquid crystal panel for a projection type liquid crystal display device (projector), a VA mode is selected as a liquid crystal material, and HTPS (high temperature polysilicon) is often selected as a TFT process (so-called HTPS-liquid crystal panel). In small and medium-sized direct-view liquid crystal panels of about 3 to 10 inches such as smartphones, VA mode or IPS mode is often selected as the liquid crystal material, and LTPS (low temperature polysilicon) is often selected as the TFT process (so-called LTPS). -LCD panel). In large direct-view liquid crystal panels of 10 inches or more such as televisions and personal computers, VA mode or IPS mode is often selected as the liquid crystal material, and amorphous silicon is often selected as the TFT process (so-called aSi-liquid crystal panel). .

The technology of the present disclosure described below, that is, the technology of the liquid crystal display device according to the embodiment of the present disclosure can be applied to a transmissive liquid crystal display device or a reflective liquid crystal display device. .

[System configuration example]
First, a system configuration of a liquid crystal display device to which the technology of the present disclosure is applied will be described with reference to FIG. FIG. 1 is a block diagram illustrating an outline of a system configuration of a liquid crystal display device to which the technology of the present disclosure is applied. The liquid crystal display device 1 according to this application example includes a liquid crystal panel 10 and a video signal processing circuit 20. Details of the configuration of the liquid crystal panel 10 will be described later.

The video signal processing circuit 20 includes an A / D (Analog / Digital) / PLL (Phase Locked Loop) unit 21, a video signal conversion unit 22, a digital signal processing unit 23, a sample hold unit 24, an image memory 25, and a control unit. 26, and performs signal processing to convert the input video signal into a signal format suitable for display on the liquid crystal panel 10.

In this video signal processing circuit 20, the A / D / PLL unit 21 performs processing for converting the input video signal into digital pixel data and processing for realizing phase synchronization when the input video signal is an analog signal. . When the input video signal is a digital signal, a configuration in which a digital interface unit is provided instead of the A / D / PLL unit 21 is adopted. The digital interface unit is a processing device that converts an input video signal by a data transmission technique such as DVI (Digital Visual Interface) method or HDMI (registered trademark) (HDMI: High-Definition Multimedia Interface) format into a digital format. is there.

The video signal conversion unit 22 performs processing for converting the pixel data output from the A / D / PLL unit 21 into pixel data (primary color data) adapted to the number of pixels of the liquid crystal panel 10 and the clock frequency. For example, when the liquid crystal panel 10 is a color liquid crystal panel, the video signal conversion unit 22 converts a composite signal or the like into an RGB separate signal suitable for driving the color liquid crystal panel, and outputs the converted signal to the digital signal processing unit 23 together with the video signal. To do.

The digital signal processing unit 23 performs processing such as contrast adjustment and crosstalk correction on the pixel data (primary color data) output from the video signal conversion unit 22. The technique of the present disclosure is applied to the digital signal processing unit 23. Specific examples thereof will be described later.

The sample and hold unit 24 performs sample and hold processing on the pixel data (primary color data) processed by the digital signal processing unit 23 for driving the liquid crystal panel 10. The function of the sample hold unit 24 may be included in the digital signal processing unit 23.

The image memory 25 temporarily stores (buffers) the pixel data (primary color data) output from the sample and hold unit 24, and supplies the pixel data to the liquid crystal panel 10, more specifically, to the horizontal driving unit 13 in the liquid crystal panel 10. Output at the timing.

The control unit 26 includes, for example, a processor such as an MPU (Micro Processing Unit), and the entire liquid crystal display device 1, specifically, the control unit 26 includes a video signal conversion unit 22, a digital signal processing unit 23, and a sample The hold unit 24 and the like are controlled. The control unit 26 controls the driving of the vertical driving unit 12 and the horizontal driving unit 13 in the liquid crystal panel 10 at a predetermined timing according to the RGB separate signal.

[Configuration example of LCD panel]
Next, an example of the configuration of the liquid crystal panel 10 will be described. The pixel driving method may be a passive matrix method or an active matrix method. Hereinafter, the active matrix method will be described as an example. An example of the configuration of the active matrix liquid crystal panel 10 is shown in FIG. 2A.

As shown in FIG. 2A, a liquid crystal panel 10 includes a pixel array unit 11 in which a plurality of pixels 2 including liquid crystal elements are two-dimensionally arranged in a matrix, and a peripheral circuit arranged around the pixel array unit 11. It has the composition which has a part. The peripheral circuit unit includes a vertical driving unit 12, a horizontal driving unit 13, and the like. The peripheral circuit unit is integrated on the same substrate as the pixel array unit 11, and drives each pixel 2 of the pixel array unit 11. The liquid crystal panel 10 includes a terminal portion (not shown) for inputting a signal from the outside and outputting a signal to the outside. For example, an external substrate (not shown) is connected to the terminal portion via a flexible substrate, and the video signal processing circuit 20 is mounted on the external substrate.

In the pixel array unit 11, the scanning lines 31 ₁ to 31 _m (hereinafter sometimes collectively referred to as “scanning lines 31”) are arranged along the row direction for each pixel row with respect to the matrix-like pixel arrangement. Wired. In addition, signal lines 32 ₁ to 32 _n (hereinafter sometimes collectively referred to as “signal lines 32”) are wired along the column direction for each pixel column. In other words, the scanning lines 31 ₁ to 31 _m and the signal lines 32 ₁ to 32 _n are wired in a matrix, and the pixels 2 are formed at the intersections.

In the peripheral circuit section, the vertical drive section 12 is provided connected to the ends of the scanning lines 31 ₁ to 31 _m . The vertical driving unit 12 is configured by a shift register or the like, and outputs a scanning signal for driving when writing a video signal to the pixel 2 to the scanning lines 31 ₁ to 31 _m .

The horizontal drive unit 13 is connected to the ends of the signal lines 32 ₁ to 32 _n . The horizontal drive unit 13 takes in a video signal to be written to each pixel 2 of the pixel row (selected row) selected by the vertical drive unit 12 from the external video signal processing circuit 20 and applies it to the signal lines 32 ₁ to 32 _n . Output.

The driving method for writing the video signal to the pixel 2 may be dot-sequential driving in which the video signal is written to each pixel 2 in the selected row in units of pixels, or the video signal may be sent to each pixel 2 in the selected row. Line-sequential driving for writing in units of pixel rows may be used.

[Pixel circuit example]
Next, a circuit example of the pixel 2 will be described. An example of the circuit configuration of the pixel 2 is shown in FIG. 2B. As shown in the equivalent circuit diagram of FIG. 2, the pixel 2 includes a liquid crystal element LC, a capacitor element C, and a pixel transistor Tr.

One electrode of the liquid crystal element LC is an independent electrode (pixel electrode described later) for each pixel 2, and is connected to one electrode (source / drain electrode) of the pixel transistor Tr and one end of the capacitor element C. Yes. The other electrode of the liquid crystal element LC is an electrode common to all the pixels 2 (a counter electrode described later), and is grounded, for example.

The capacitive element C is an element for stabilizing the accumulated charge of the liquid crystal element LC. One end of the capacitive element C is connected to one electrode of the liquid crystal element LC and one electrode of the pixel transistor Tr. The other end of the capacitive element C is connected to the capacitive line 33.

The pixel transistor Tr is a switching element for writing a video signal to the liquid crystal element LC, and includes a thin film transistor (TFT). The pixel transistor Tr has a gate electrode connected to the scanning line 31, one electrode connected to one electrode of the liquid crystal element LC and one end of the capacitor C, and the other electrode (drain / source electrode) connected to the signal line 32. It is connected.

[Structure example of LCD panel]
Next, an example of the structure of the liquid crystal panel 10 will be described. FIG. 3A shows an exploded perspective view of an example of the structure of the liquid crystal panel 10, and FIG. 3B shows an enlarged view of the main part of FIG. 3A.

In the liquid crystal panel 10, a first substrate 41 and a second substrate 42 made of transparent substrates, for example, glass substrates are arranged to face each other at a predetermined interval, and a liquid crystal material is placed between the first substrate 41 and the second substrate 42. A panel structure is formed in which the liquid crystal layer 43 is formed. In addition, the liquid crystal panel 10 includes a polarizing plate 44 and a polarizing plate 45 that face each other with the first substrate 41 and the second substrate 42 interposed therebetween. The polarizing plate 44 and the polarizing plate 45 are disposed so that the

polarizing plate axes

44a and 45a are orthogonal to each other.

A transparent conductive film 46 is formed on the first substrate 41. In the transparent conductive film 46, a counter electrode (not shown) is formed in common for all the pixels 2 in the pixel array unit 11. Thereby, the first substrate 41 may be called a counter substrate. The counter electrode is the other electrode of the liquid crystal element LC shown in FIG. 2B. A transparent conductive film 47 is formed on the second substrate 42. On the transparent conductive film 47, pixel electrodes 48 are formed independently for each pixel 2. The pixel electrode 48 is one electrode of the liquid crystal element LC shown in FIG. 2B.

A pixel transistor Tr made of a thin film transistor (TFT) is formed on the second substrate 42. Thereby, the second substrate 42 may be called a TFT substrate. Further, the gate electrode of the pixel transistor Tr is connected to the second substrate 42 for each pixel row, and one electrode (source / drain electrode) of the pixel transistor Tr is connected to each pixel column. The signal line 32 is wired. Here, the i-th scanning line 31 _i and the (i + 1) -th scanning line 31 _{i + 1} , and the J-th column signal line 32 _j and the j + 1-th scanning line 31 _{j + 1} are illustrated.

In the liquid crystal panel 10 having the above structure, only the

liquid crystal molecules

43a and 43b in the region sandwiched between both the pixel electrode and the counter electrode among the liquid crystal molecules of the liquid crystal layer 43 are laterally arranged between the pixel electrode and the counter electrode. It changes its arrangement under the influence of an electric field and functions as a liquid crystal shutter for one pixel. Here, the horizontal electric field is an electric field generated between the pixel electrodes 48 (or between the signal lines 32) of the two adjacent pixels as shown in FIG. 3B due to the potential difference between the video signals supplied to the two adjacent pixels. It is.

By the way, liquid crystal panels (liquid crystal display devices) are classified into a completely vertical alignment type and a tilt alignment type. The complete vertical alignment type is called a so-called VA (Vertical Alignment) type, and the alignment layer (not shown) allows the liquid crystal molecules of the liquid crystal layer 43 to be placed on the substrate (the first substrate 41 and the first substrate 41) without applying a voltage to the electrode corresponding to the pixel. Two substrates 42) are oriented perpendicular to each other. That is, the tilt angle θ of the

liquid crystal molecules

43a and 43b with respect to the substrate is 90 degrees. In this state, when a voltage is applied to the electrode corresponding to the pixel, the direction in which the liquid crystal molecules fall (alignment direction) is free, so the alignment direction is not aligned.

On the other hand, the tilt alignment type uses an alignment film (not shown) to align the liquid crystal molecules of the liquid crystal layer 43 so as to be inclined with respect to the normal direction of the substrate without applying a voltage to the electrode corresponding to the pixel. The orientation is almost horizontal to the substrate. That is, as shown in FIG. 3B, the tilt angle (pretilt angle) θ of the

liquid crystal molecules

43a and 43b with respect to the substrate is θ <90 °. When the pretilt angle is set, the liquid crystal panel 10 is inclined in a predetermined direction when viewed from the front (substrate normal direction). In this state, when a voltage is applied to the electrode corresponding to the pixel, the tilt direction (orientation direction) is determined by the pretilt. Since the orientation direction of the liquid crystal molecules is determined in one direction, the transmitted light in the pixel becomes uniform, and a good image display can be performed.

[Change in image quality with time due to leak between pixels]
By the way, in the liquid crystal panel 10, when moisture enters the liquid crystal layer 43 from the seal portion that seals the liquid crystal material between the first substrate 41 and the second substrate 42 in an environment such as high temperature and high humidity, two adjacent A so-called inter-pixel leak occurs in which a leak current flows between pixels. When an inter-pixel leak occurs, the potential difference between adjacent pixels becomes small, so that the image quality of the output image changes with time, such as characters appearing thick.

FIG. 4A shows the moisture state of the liquid crystal layer 43 in the initial state of the liquid crystal panel 10, FIG. 4B shows an example of the pixel potential in the initial state, and FIG. 4C shows the video signal V _sig in the initial state−transmittance T The characteristics are shown. Here, the case of normally black is illustrated. FIG. 4B illustrates a case where, in the adjacent five pixels pix1 to pix5, the potential of the middle pixel pix3 is 0V, and the potentials of the other four pixels pix1, pix2, pix4, and pix5 are 3V. In the initial state, no leak between pixels occurs. Therefore, as shown in FIG. 4C, the transmittance T of the pixel pix3 is 0%, and the transmittances T of the pixels pix1, pix2, pix4, and pix5 are about 60%, for example.

FIG. 5A shows the moisture state of the liquid crystal layer 43 in the moisture absorption state of the liquid crystal panel 10 (that is, the state where moisture has entered the liquid crystal layer 43), FIG. 5B shows an example of the pixel potential in the moisture absorption state, and FIG. The characteristics of the video signal V _{sig -transmittance} T in the moisture absorption state are shown below. As shown in FIG. 5A, when moisture enters the liquid crystal layer 43 in a high-temperature and high-humidity environment, a leak path is formed between the pixels and a leak current flows as shown in FIG. 5B.

Due to the occurrence of inter-pixel leakage, as an example, the potential of the middle pixel pix3 that was 0V in the initial state is 1V, the potentials of the pixels pix2 and pix4 that were 3V in the initial state are 2.5V, the pixel pix1, Each potential of pix5 is 2.9V. That is, the potential difference between the pixel pix3 that was 3V in the initial state and the adjacent pixels pix2 and pix4 becomes a potential difference of 1.5V in the moisture absorption state.

As a result, as shown in FIG. 5C, the transmittances T of the pixels pix2 and pix4 are about 25%, for example, and the transmittances T of the pixels pix1 and pix5 are about 55%, for example. In other words, when the potential difference between adjacent pixels is reduced due to inter-pixel leakage, the difference in transmittance T is reduced. Therefore, when the character is displayed, the character looks sharp and the sharpness is reduced. The image quality changes with time.

In the above, taking the case where leakage between pixels occurs due to moisture as an example, it has been explained that the potential difference between adjacent pixels becomes small and the image quality of the output image changes with time. It is not limited to the case. For example, leaks between pixels occur due to changes in domains (disturbed alignment of liquid crystal molecules), gaps (distance between two adjacent pixels), liquid crystal composition changes, pretilt angles (tilt angles of liquid crystal molecules with respect to the substrate), etc. In some cases, the potential difference between the pixels is small.

<Embodiment of the Present Disclosure>
Therefore, in the embodiment of the present disclosure, the digital signal processing unit 23 illustrated in FIG. 1 detects a difference in drive voltage between two adjacent pixels, and a correction target that causes a luminance change due to the difference in the drive voltage. A correction amount for correcting the driving voltage of the pixel is calculated. Then, the calculated correction amount is adjusted according to the image quality of the output image, and the drive voltage of the correction target pixel is corrected based on the adjusted correction amount.

FIG. 6 is a block diagram illustrating an example of a configuration of the digital signal processing unit 23 according to the embodiment of the present disclosure.

The digital signal processing unit 23 according to the present embodiment is a correction processing unit that performs correction processing on a video signal, and includes a voltage difference calculation unit 231 between adjacent pixels, a correction amount calculation unit 232, a correction amount adjustment unit 233, and a correction. The amount adding unit 234 is included.

Regarding the adjacent pixel voltage difference calculation unit 231, the correction amount calculation unit 232, the correction amount adjustment unit 233, and the correction amount addition unit 234, a processor such as an MPU interprets and executes a program that realizes each function. Therefore, it can be configured to be executed by software. However, the configuration is not limited to being executed by software, and each functional unit may be configured as a hardware configuration.

That is, in the driving method (signal processing method) according to the present embodiment, the voltage difference calculation unit 231 between the adjacent pixels, the correction amount calculation unit 232, the correction amount adjustment unit 233, and the correction amount addition unit 234 are changed to a difference. A detection step, a correction amount calculation step, a correction amount adjustment step, and a drive voltage correction step can be used.

The adjacent pixel voltage difference calculation unit 231 is a difference detection unit that detects a difference in drive voltage between two adjacent pixels. A voltage difference calculation unit 231 between adjacent pixels, based on the video signal input from the video signal conversion unit 22 in FIG. 1, a drive voltage supplied to the own pixel that performs correction (hereinafter referred to as “correction target pixel”), Then, a process of calculating a difference from a drive voltage supplied to a pixel adjacent to the correction target pixel (hereinafter referred to as “adjacent pixel”), that is, a voltage difference between adjacent pixels is performed.

The correction amount calculation unit 232 acquires the voltage difference between adjacent pixels calculated by the voltage difference calculation unit 231 between adjacent pixels and the video signal data (drive voltage information) for the correction target pixel. Correction setting information is also input to the correction amount calculation unit 232. Details of the correction setting information will be described later. The correction amount calculation unit 232 refers to the correction setting information based on the acquired information, and performs a process of calculating the correction amount of the drive voltage supplied to the correction target pixel.

The correction amount adjustment unit 233 performs a process of adjusting the correction amount calculated by the correction amount calculation unit 232 according to the image quality of the output image. The correction amount adjustment unit 233 is a functional unit that characterizes the present embodiment, and a specific example of the processing will be described later.

The correction amount addition unit 234 adds the correction amount reflecting the image quality of the output image to the video signal data (drive voltage information) supplied to the correction target pixel by adjusting the correction amount in the correction amount adjustment unit 233, The addition result is output as an output video signal to the sample hold unit 24 in FIG. That is, the correction amount addition unit 234 is a drive voltage correction unit that corrects the drive voltage of the correction target pixel based on the correction amount adjusted by the correction amount adjustment unit 233.

[Adjacent pixel voltage difference calculation unit]
Next, a specific configuration of the voltage difference calculation unit 231 between adjacent pixels in the digital signal processing unit 23 will be described with reference to FIG. FIG. 7 is a block diagram illustrating an example of the configuration of the voltage difference calculation unit 231 between adjacent pixels.

Since the digital signal processing unit 23 targets correction not only in the horizontal scanning direction but also in the vertical scanning direction, the digital signal processing unit 23 is configured to be capable of delay control of the input video signal. That is, the digital signal processing unit 23 includes a synchronization separation unit 235 and a delay control unit 236 in addition to the adjacent pixel voltage difference calculation unit 231 and the like.

The sync separator 235 performs a process of separating the sync signal from the video signal. When the input video signal is a monochrome (monochrome) video signal, the signal after the synchronization signal is separated from the video signal is a luminance signal. When the input video signal is a color video signal, the signal after the synchronization signal is separated from the video signal includes luminance information and color information. Examples of color video signals include RGB signals.

The delay control unit 236 delays the synchronization signal separated from the input video signal by the synchronization separation unit 235, outputs the delayed synchronization signal to the adjacent pixel voltage difference calculation unit 231, and also outputs the sample of FIG. 1 as an output synchronization signal. Output to the hold unit 24.

In the digital signal processing unit 23 capable of delay control of the input video signal, the adjacent pixel voltage difference calculation unit 231 includes a memory control unit 2311, a horizontal voltage difference calculation unit 2312, and a vertical voltage difference calculation unit 2313. It has a configuration.

The memory control unit 2311 includes a line memory 2314, and performs a process of delaying the input video signal for each line (one scanning line) at a time (timing) based on the delay synchronization signal supplied from the delay control unit 236. For the line memory 2314, for example, a RAM (Random Access Memory) can be used. In the following description, a video signal delayed for each line from the memory control unit 2311 is described as a line video signal.

The horizontal voltage difference calculation unit 2312 performs a process of detecting a voltage difference between the drive voltages supplied to the own pixel and the adjacent pixels in the horizontal scanning direction based on the line video signal supplied from the memory control unit 2311. Do. That is, the horizontal direction voltage difference calculation unit 2312 regards the N-th pixel (self-line) of the same line when the N-th pixel (N is an arbitrary natural number) of a certain line is set as its own pixel in time series regarding horizontal processing. The difference (voltage difference) between the drive voltage supplied to the pixel) and the drive voltage supplied to the adjacent N−1 pixel is calculated. Similarly, the horizontal voltage difference calculation unit 2312 calculates a difference (voltage difference) between the drive voltage supplied to the Nth pixel (own pixel) on the same line and the drive voltage supplied to the adjacent N + 1 pixel. To do. The voltage difference between the own pixel and each of the (N−1) th pixel and the (N + 1) th pixel calculated by the horizontal voltage difference calculation unit 2312 is supplied to the correction amount calculation unit 232 of FIG. 6 together with the line video signal. .

The vertical direction voltage difference calculation unit 2313 performs processing for detecting a voltage difference between the own pixel and the adjacent pixel in the vertical scanning direction based on the line video signal supplied from the memory control unit 2311. In other words, the vertical voltage difference calculation unit 2313 regards the M-th line pixel (own pixel) when the M-th line (M is an arbitrary natural number) pixel is set as the own pixel in time series regarding vertical processing. The difference (voltage difference) between the drive voltage supplied to the drive voltage and the drive voltage supplied to the adjacent pixels on the (M−1) th line is calculated. Similarly, the vertical direction voltage difference calculation unit 2313 calculates the difference (voltage difference) between the drive voltage supplied to the pixel on the M-th line (own pixel) and the drive voltage supplied to the adjacent pixel on the M + 1-th line. calculate. The voltage difference between the pixel (own pixel) of the own line (M line) calculated by the vertical direction voltage difference calculation unit 2313 and each adjacent pixel of the (M−1) -th line and the (M + 1) -th line is the correction amount calculation of FIG. Supplied to the unit 232.

In a color display device, when one pixel (main pixel), which is a unit for forming a color image, is composed of, for example, RGB subpixels (subpixels), the above-described voltage difference between the horizontal direction and the vertical direction Is calculated for each of the RGB sub-pixels. That is, the adjacent pixel voltage difference calculation unit 231 includes difference information of two systems of the Nth pixel (own pixel), the (N−1) th pixel, and the (N + 1) th pixel, and the Mth line's own pixel and the M−1th line. The difference information of the two systems from the adjacent pixels on the first and (M + 1) th lines is calculated for each of the RGB sub-pixels.

[Correction amount calculator]
Next, a specific configuration of the correction amount calculation unit 232 in the digital signal processing unit 23 will be described with reference to FIG. FIG. 8 is a block diagram illustrating an example of the configuration of the correction amount calculation unit 232. The correction amount calculation unit 232 includes a horizontal direction selection unit 2321, a vertical direction selection unit 2322, a correction amount calculation unit 2323, and a correction amount interpolation unit 2324.

The image quality failure phenomenon to be processed by the digital signal processing unit 23 according to the present embodiment is a property that the image quality failure occurrence direction on the liquid crystal panel 10 does not change in the inversion / non-inversion of the video signal (inversion / non-inversion of the scanning direction). have. That is, the direction in which the image quality failure phenomenon occurs is constant between pixels where a voltage difference occurs. For this reason, it is necessary to perform a correction process in the same direction regardless of the horizontal / vertical scanning direction.

For example, in the right evaporation liquid crystal display device, when a picture quality defect occurs in the left pixel of a black level pixel, if there is a voltage difference between the black level pixel and the left pixel where the video signal is inverted, the left side An image quality defect occurs in the pixel. As an example, in the case of a projection type liquid crystal display system (projector system) using a liquid crystal panel as a light modulation means (light valve), inversion / non-inversion is caused by a projection method or the like. For this reason, in order to correctly display the output image, it is necessary to set inversion / non-inversion (scanning direction).

The correction amount calculation unit 232 selects a voltage difference information to be used from a plurality of voltage difference information calculated by the horizontal voltage difference calculation unit 2312 and the vertical voltage difference calculation unit 2313 in FIG. 2321 and a vertical direction selection unit 2322 are provided. The correction amount calculation unit 232 further includes a correction amount calculation unit 2323 and a correction amount interpolation unit 2324.

The horizontal direction selection unit 2321 obtains, from the horizontal direction voltage difference calculation unit 2312, voltage difference information between its own pixel and adjacent pixels in the horizontal scanning direction, and a horizontal scanning line signal supplied from the control unit 26 in FIG. . The voltage difference information between the own pixel and the adjacent pixel in the horizontal scanning direction is the difference between the drive voltage supplied to the Nth pixel (own pixel) on the same line and the drive voltage supplied to the adjacent N−1 pixel. The difference is the difference between the drive voltage supplied to the Nth pixel (own pixel) on the same line and the drive voltage supplied to the adjacent N + 1 pixel.

The horizontal scanning line signal is information on the horizontal scanning direction for the pixel array unit 11 (see FIG. 2A) in which the pixels 2 are two-dimensionally arranged in a matrix, that is, the horizontal scanning direction is from left to right, or conversely, Contains information indicating whether it is from right to left. Alternatively, information in the horizontal scanning direction may be obtained by analyzing the horizontal scanning line signal itself. Then, the horizontal direction selection unit 2321 selects a pixel (correction target pixel) whose drive signal is to be corrected based on the horizontal direction voltage difference information and the horizontal scanning line signal, and supplies the selection information to the correction amount calculation unit 2323. To do.

The vertical direction selection unit 2322 obtains, from the vertical direction voltage difference calculation unit 2313, voltage difference information between its own pixel and adjacent pixels in the vertical scanning direction, and a vertical scanning line signal supplied from the control unit 26. The voltage difference information between the own pixel and the adjacent pixel in the vertical scanning direction includes the drive voltage supplied to the pixel on the M line (the own pixel), and the drive voltage supplied to the adjacent pixel on the M−1 line. And the difference between the drive voltage supplied to the pixel (own pixel) on the M line and the drive voltage supplied to the adjacent pixel on the M + 1 line.

The vertical scanning line signal includes information in the vertical scanning direction with respect to the pixel array unit 11, that is, information indicating whether the vertical scanning direction is from the top to the bottom or, conversely, from the bottom to the top. Alternatively, information in the vertical scanning direction may be obtained by analyzing the vertical scanning line signal itself. Then, the vertical direction selection unit 2322 selects a pixel (correction target pixel) whose drive signal is to be corrected based on the vertical direction voltage difference information and the vertical scanning line signal, and supplies the selection information to the correction amount calculation unit 2323. To do.

Here, the voltage difference signal (voltage difference information) input from the voltage difference calculation unit 231 between adjacent pixels will be described by taking a horizontal voltage difference as an example. FIG. 9 is a diagram showing drive voltage levels for a display image 140 and an image 140A of the center line of the input video signal. FIG. 10A shows a display image 141 after image quality failure, FIG. 10B shows a voltage difference signal obtained by taking a voltage difference between the own pixel and the (N + 1) th pixel, and FIG. 10C shows the own pixel and N−1. The voltage difference signal which took the voltage difference with a pixel is shown.

In FIG. 9, the image 140A of the center line of the display image 140 is composed of 8 pixels. Of these eight pixels, the central four pixels are at the black level, and the surrounding four pixels are at the gray level. The leftmost pixel 141b of the four black level pixels is adjacent to the gray level pixel 141a, and the rightmost pixel 141c of the four black level pixels is adjacent to the gray level pixel 141d.

Here, in FIG. 10A showing the display image 141 after the image quality failure occurs, the image 141A in the center line of the display image 141 seems to have white blurring in the pixel 141a adjacent to the leftmost pixel 141b of the black level of four pixels. Is displayed. Under such circumstances, the voltage difference signal shown in FIGS. 10B and 10C is output from the horizontal voltage difference calculation unit 2312 based on the input video signal.

FIG. 10B shows a voltage difference signal obtained by taking a voltage difference between the own pixel and the (N + 1) th pixel, that is, a voltage level difference obtained by subtracting the drive voltage level of the own pixel from the drive voltage level of the pixel adjacent to the right side of the own pixel. Yes. In FIG. 10B, the voltage difference between the pixel 141a and the pixel 141b (the difference between the black potential and the gray potential) is positive, and the voltage difference between the pixel 141c and the pixel 141d (the difference between the gray potential and the black potential) is negative. It is.

FIG. 10C shows a voltage difference signal obtained by taking a voltage difference between the own pixel and the (N−1) th pixel, that is, a voltage level obtained by subtracting the drive voltage level of the pixel adjacent to the own pixel from the drive voltage level of the own pixel. Showing the difference. In FIG. 10C, the voltage difference (difference between gray potential and black potential) between the pixel 141a and the pixel 141b is negative, and the voltage difference between pixel 141c and pixel 141d (difference between the black potential and gray potential) is positive. It is. A candidate for a correction target position can be detected from the waveform of the voltage level difference.

In this way, depending on the scanning direction, the voltage difference signal obtained by taking the voltage difference between the own pixel and the (N + 1) th pixel and the voltage difference signal taking the voltage difference between the own pixel and the (N−1) th pixel are shown as signal waveforms. Is completely different. The same applies to the vertical scanning direction. In such a case, when a voltage difference occurs between two adjacent pixels by the horizontal direction selection unit 2321 and the vertical direction selection unit 2322, for example, the front pixel is set as a correction target pixel in time series, It is possible to select whether the pixel is a correction target pixel. This selection signal may be defined and specified by the user. Alternatively, a pixel in which an image quality defect occurs depends on a difference in structure between liquid crystal display devices such as a TN type and a VA type, an evaporation direction (a direction of pretilt), and the like, so that the horizontal direction selection unit 2321 and the vertical direction selection unit 2322 Information indicating the structure of the display device, vapor deposition direction information, and the like may be acquired and reflected in the selection signal.

The correction amount calculation unit 2323 is supplied from the horizontal direction selection information supplied from the horizontal direction selection unit 2321, the vertical direction selection information supplied from the vertical direction selection unit 2322, and the horizontal voltage difference calculation unit 2312 in FIG. Input line video signal. Then, the correction amount calculation unit 2323 calculates a drive voltage correction amount for the correction target pixel based on the horizontal direction selection information, the vertical direction selection information, and the line video signal.

The horizontal direction selection information supplied from the horizontal direction selection unit 2321 includes the voltage difference between the own pixel and the (N−1) th pixel on the same line and the voltage difference between the own pixel and the (N + 1) th pixel in accordance with the horizontal scanning line signal. Any information is included. Similarly, the vertical direction selection information supplied from the vertical direction selection unit 2322 includes the voltage difference between the M-th line's own pixel and the adjacent pixel on the M−1th line according to the vertical scanning line signal, Information on any of the voltage differences between the own pixel and the adjacent pixel on the M + 1th line is included. Further, the line video signal supplied from the horizontal direction voltage difference calculation unit 2312 includes drive voltage information for each pixel including the own pixel and the correction target pixel.

The correction amount calculation unit 2323 uses the driving voltage information for the correction target pixel included in the horizontal direction selection information, the vertical direction selection information, and the line video signal as parameters, and calculates the correction amount of the driving voltage for the correction target pixel. calculate. The correction amount calculation unit 2323 is a two-dimensional or three-dimensional lookup table (hereinafter, referred to when calculating the drive voltage correction amount based on the horizontal direction selection information, the vertical direction selection information, and the drive voltage information). , Described as “LUT”) 2325.

The LUT 2325 should be added to the correction target pixel corresponding to the difference between the voltage level of the input video signal of the own pixel and the set voltage level of the pixel adjacent to the own pixel, that is, the voltage level between the own pixel and the adjacent pixel. The correction setting information for setting the correction amount is stored. The correction amount is such that the average luminance of the correction target pixel after correcting the driving voltage for the correction target pixel is the same as that when the driving voltage based on the input video signal before correction is supplied to the correction target pixel. Is set to By doing so, the display pattern of the display image before correction is the same as the display pattern of the display image after correction.

Here, correction setting information referred to in order to calculate the drive voltage correction amount will be described. An example of correction setting information to be referred to when calculating the correction amount is shown in FIG. FIG. 11 shows the relationship between the correction amount of the drive voltage, the drive voltage of the own pixel, and the voltage difference with the adjacent pixel. The hollow column in FIG. 11 is not corrected. In addition, the numerical value shown in FIG. 11 is an example, Comprising: It is not restricted to these numerical values. Here, when the driving voltage of the own pixel is 0 V and the driving voltage of the adjacent pixel is 3.975 V, the voltage difference from the adjacent pixel is 3.975 V. Therefore, in the correction setting information shown in FIG. The 1.2V shown is the correction amount of the own pixel (correction target pixel), and the drive voltage of the own pixel is corrected from 0V to 1.2V.

In the LUT 2325, correction target points determined by the relationship between the voltage level of the input video signal of the own pixel and the voltage level difference between the two pixels of the own pixel and the adjacent pixel are set discretely. When the voltage level difference between the own pixel and the adjacent pixel is small, the generated horizontal electric field is weak and image quality is less likely to occur. Accordingly, a threshold for the difference in voltage level between the own pixel and the adjacent pixel is set, and when this threshold is exceeded, the drive voltage is corrected for the correction target pixel. By doing so, it is possible to efficiently perform correction only for pixels that are highly effective in improving image quality defects when corrected without correcting all the pixels 2 of the liquid crystal panel 10. Note that the correction amount may also be defined and specified by the user.

In the LUT 2325, there are a plurality of tables corresponding to the environmental information of the liquid crystal panel 10 supplied from the control unit 26 of FIG. The environmental information of the liquid crystal panel 10 includes, for example, a horizontal / vertical scanning direction, a pretilt direction, and a distance (gap) between two adjacent pixels. Therefore, when the horizontal scanning direction is from left (right) to right (left), the table is referred to in relation to the own pixel and the left (right) side adjacent pixel, and the vertical scanning direction is from top (bottom) to bottom (top). In this case, a table is prepared for reference in relation to the own pixel and the upper (lower) adjacent pixel.

Also, a table to be referred to when the pretilt direction is left (right) with respect to the front of the liquid crystal panel 10 is prepared. Furthermore, since the strength of the generated lateral electric field changes depending on the distance (gap) between two adjacent pixels, even if the drive voltage applied to the two adjacent pixels is the same or the voltage difference between the two pixels is the same, The set value of the correction amount of the drive voltage for the correction target pixel is changed in consideration of the gap between the two pixels. Thus, the contents and correction amount are set in the LUT 2325 so as to correspond to various environment information or combinations thereof.

The correction amount interpolation unit 2324 interpolates and outputs the correction amount calculated by the correction amount calculation unit 2323 with reference to the LUT 2325. For example, since the correction target points are set discretely in the LUT 2325, there may be no correction target points that directly correspond to the voltage level of the input video signal of the own pixel. In this case, the correction amount interpolation unit 2324 selects, for example, two correction target points closest to the voltage level of the input video signal. Similarly, when there is no correction target point that directly corresponds to the voltage level difference between the two pixels of the own pixel and the adjacent pixel, the correction amount interpolation unit 2324, for example, uses the two correction targets closest to the voltage level difference between the two pixels. Select a point. Then, the correction amount interpolation unit 2324 performs interpolation processing such as linear interpolation on these four correction target points for the correction amount, and outputs the processing result to the correction amount adjustment unit 233 in FIG.

[Correction amount adjustment unit]
Next, the correction amount adjustment unit 233 in the digital signal processing unit 23, which is a functional unit characteristic of the present embodiment, will be described.

As described above, the correction amount calculation unit 232 refers to the correction setting information based on the voltage difference between adjacent pixels and the video signal data (drive voltage information) for the correction target pixel and supplies the correction setting information to the correction target pixel. The correction amount of the drive voltage is calculated. Hereinafter, the correction amount calculated by the correction amount calculation unit 232 is referred to as a correction amount X.

The correction amount calculation unit 232 sets the correction amount X of the drive voltage of the correction target pixel as a fixed value, assuming the state of the liquid crystal panel 10 after a certain amount of time has elapsed. In the correction process using the correction value X of the fixed value as it is, the liquid crystal panel 10 in the initial state that has not changed with time may be overcorrected, and conversely, the liquid crystal panel 10 that has changed with time more than previously assumed. Then, there is a case where the correction is insufficient. In either case, the image quality of the output image is degraded. Further, the image quality of the output image becomes worse as the change with time (deterioration with time) of the liquid crystal panel 10 progresses.

Therefore, in the present embodiment, a configuration in which a correction amount adjustment unit 233 that adjusts the correction amount X calculated by the correction amount calculation unit 232 in accordance with the image quality of the output image is provided at the subsequent stage of the correction amount calculation unit 232. Adopted. The correction amount adjustment unit 233 adjusts the correction amount X for correcting the driving voltage of the correction target pixel according to the image quality of the output image, so that the state of the image quality of the output image according to the degree of change with time is corrected. This is reflected in the correction amount X of the driving voltage of the pixel. As a result, the drive voltage of the correction target pixel can be corrected without being affected by the change over time of the liquid crystal panel 10, and the image quality of the output image can be improved.

The correction amount adjustment unit 233 needs to detect (understand) the state of the image quality of the output image in adjusting the correction amount X of the drive voltage of the correction target pixel. As a method for detecting the state of the image quality of the output image, various methods listed below can be exemplified.

First Detection Method The image quality of the output image changes over time due to moisture intrusion and the like. Therefore, by measuring the usage time of the liquid crystal panel 10, it is possible to indirectly detect the degree of change over time in the image quality of the output image (image quality state) from the measurement time. In other words, the first detection method is a method in which the usage time of the liquid crystal panel 10 is measured by a counter and the image quality state of the output image is detected using the counter result (count value) as a parameter.

Second Detection Method The image quality of the output image is also affected by the usage environment of the liquid crystal panel 10, particularly the temperature and humidity. Therefore, by measuring the temperature and humidity under the usage environment of the liquid crystal panel 10, and adding the measurement result as one of the parameters to the usage time of the liquid crystal panel 10, the detection accuracy of the image quality of the output image can be improved. it can. At this time, it is conceivable to add temperature alone, humidity alone, or both temperature and humidity as parameters. That is, the second detection method is a method of detecting the state of the image quality of the output image using the temperature, humidity, or temperature and humidity under the usage environment of the liquid crystal panel 10 as parameters in addition to the usage time of the liquid crystal panel 10. It is.

Third detection method The third detection method uses an imaging unit (imaging device) to capture an output image, and directly determines the degree of temporal change in image quality of the output image (image quality state) from the imaging result. This is a detection method. As an example, in the case of a projection type liquid crystal display system (projector system) using the liquid crystal panel 10 as a light modulation means (light valve), as shown in FIG. 12, the vicinity of a projection lens 114 (see FIG. 21) described later of the projector 51. The imaging unit 52 is disposed in the area. And by imaging the output image 54 projected on the screen 53 with the imaging part 52, the state of the image quality of the output image 54 can be directly detected from the imaging result.

Note that the method for detecting the state of the image quality of the output image is not limited to the above-described first detection method, second detection method, or third detection method. For example, since the degree of moisture absorption of the liquid crystal panel 10 can be detected by chromaticity, the chromaticity of the liquid crystal panel 10 is measured using a chromaticity meter, and the measurement result is used as one of parameters, or a luminance meter is used. It is also possible to measure the luminance of the liquid crystal panel 10 and use the measurement result as one of the parameters.

Here, as an example, a case where the degree of moisture absorption of the liquid crystal panel 10 is detected under the measurement of chromaticity will be described. When the display of white stripes and black stripes is repeated in pixel row units (or pixel column units), that is, when the potential difference between two adjacent pixels is the largest, inter-pixel leakage is likely to occur. Therefore, in a projection type liquid crystal display system, the luminance when only white stripes are displayed is measured as illuminance A, the luminance when only black stripes are displayed is measured as illuminance B, and white stripes and black stripes are alternately displayed. The brightness when displayed on the screen is measured as illuminance C. Then, a moisture absorption index (degree of moisture absorption) is obtained from illuminance C / (average of illuminance A and illuminance B), and the moisture absorption index is used as one of the parameters for detecting the state of the image quality of the output image. it can.

Hereinafter, specific examples of the correction amount adjustment unit 233 when adjusting the correction amount based on the acquisition result of the output image acquired using the third detection method will be described as Example 1 and Example 2. explain. A specific example of the correction amount adjustment unit 233 when adjusting the correction amount based on the usage time acquired using the first detection method will be described as a second embodiment.

Example 1
In the first embodiment, the correction amount adjustment unit 233 detects the state of the image quality of the output image from the imaging result of the adjusted image (output image), and reflects the image quality information on the correction amount X, that is, the output image In this example, the above-described third detection method is applied to the detection of the image quality state. In the first embodiment, the above-described moisture absorption index is used as a parameter for determining whether or not the driving voltage of the correction target pixel needs to be corrected. The same applies to the following embodiments. FIG. 13 shows a flow of processing for correction amount adjustment in the correction amount adjustment unit 233 according to the first embodiment.

A series of processes for adjusting the correction amount described below is executed by software under the control of a processor such as an MPU configuring the digital signal processing unit 23 of FIG. However, the present invention is not limited to a configuration that is executed by software, and each functional unit that executes processing for adjusting the correction amount may have a hardware configuration. The same applies to the embodiments described later.

In the flowchart of FIG. 13, the processor supplies an adjustment image video signal for adjusting the correction amount to the projector 51 of FIG. 12 to output the adjustment image (step S <b> 11), and then the adjustment projected on the screen 53. Image data obtained by imaging an image, that is, an output image using the imaging unit 52 is acquired (step S12). Next, the processor digitizes the image quality data of the adjusted image (output image) based on the acquired image data (step S13), and then according to the image quality state of the output image based on the digitized image quality data A correction coefficient α is set (step S14).

The image quality of the output image deteriorates (deteriorates) as the liquid crystal panel 10 changes with time. An example of the relationship between the usage time of the liquid crystal panel 10, the state of the image quality of the output image, and the correction coefficient α is shown in FIG. As shown in FIG. 14, the initial state of the liquid crystal panel 10, one year later, three years later, and so on, etc., the image quality of the output image is deteriorated according to the usage time of the liquid crystal panel 10. Therefore, in step S14, a value corresponding to the image quality state of the output image is set as the correction coefficient α.

Next, the processor obtains the image quality data after reflecting the correction coefficient α set in step S14, that is, the corrected image quality data by calculation (step S15), and then compares the image quality data with the reference image quality data to perform correction. It is determined whether or not it is necessary to correct the drive voltage of the target pixel (step S16).

Here, the reference image quality data to be compared with the corrected image quality data may be an initial value (image quality data in the initial state), or a value in a predetermined image quality setting range with the initial value as a reference. You can also. For example, based on the change in the moisture absorption index (the degree of moisture absorption) described above, as shown in FIG. 15, the image quality setting range of, for example, ± 5% is driven based on the initial value (moisture absorption index = 50%). The threshold is used to determine whether or not the voltage needs to be corrected.

In the determination process of necessity of correction in step S16, it is determined that correction is necessary when the image quality falls below the image quality setting range. If the processor determines that correction is necessary (YES in S16), the correction coefficient α set in step S14 is set to the correction amount X of the drive voltage of the correction target pixel calculated by the correction amount calculation unit 232. Is reflected (step S17), and then a series of processing for adjusting the correction amount is completed.

In step S17, specifically,
(Correction amount X based on voltage difference between two pixels) × (correction coefficient α according to the image quality of the output image)
The arithmetic processing is performed. The calculation result is a correction amount αX that reflects (feeds back) the correction coefficient α corresponding to the image quality of the output image to the correction amount X based on the voltage difference between the two pixels.

The feedback of the correction coefficient α is performed on the correction setting information shown in FIG. FIG. 16 shows an example of correction setting information after feedback of the correction coefficient α. FIG. 16 shows the relationship between the correction amount of the drive voltage, the drive voltage of the own pixel, and the voltage difference with the adjacent pixel. The hollow column in FIG. 16 is not corrected. In addition, the numerical value shown in FIG. 16 is an example, Comprising: It is not restricted to these numerical values.

When the processor determines that the correction is unnecessary (NO in S16), the correction coefficient α does not need to be reflected in the correction amount X based on the voltage difference between the two pixels. The correction amount X is used as it is (step S18), and a series of processes for adjusting the correction amount is terminated.

According to the correction amount adjustment in the correction amount adjustment unit 233 according to the first embodiment described above, the output image is captured by the imaging unit 52, and the state of the image quality of the output image is grasped from the imaging result. It is possible to detect the state of the image quality of the output image accompanying a change with time. Then, the correction coefficient α is set based on the state of the image quality of the output image and fed back to the correction amount X of the drive voltage of the correction target pixel, so that the drive voltage can be adjusted without being affected by the change over time of the liquid crystal panel 10. Since correction can be performed, the image quality of the output image can be improved.

(Example 2)
The second embodiment is a modification of the first embodiment. In the first embodiment, the correction coefficient α corresponding to the state of the image quality of the output image is set, the image quality data (corrected image quality data) after the correction coefficient α is reflected is calculated, and compared with the reference image quality data. Thus, the necessity of correction is determined. On the other hand, in the second embodiment, the adjusted image after the correction coefficient α is reflected is output, the corrected image quality data is digitized based on the image data acquired again, and compared with the reference image quality data. Determine whether correction is necessary.

FIG. 17 shows a flow of processing for correction amount adjustment in the correction amount adjustment unit 233 according to the second embodiment. In the flowchart of FIG. 17, the processor outputs an adjustment image for adjusting the correction amount from the projector 51 (step S <b> 21), and then an image obtained by imaging the output image on the screen 53 using the imaging unit 52. Data is acquired (step S22).

Next, the processor digitizes the image quality data of the output image based on the acquired image data (step S23), and then calculates a correction coefficient α according to the state of the image quality of the output image based on the digitized image quality data. Set (step S24). The correction coefficient α is the same as in the first embodiment.

Next, the processor corrects the adjusted image using the correction coefficient α, causes the adjusted image to be output from the projector 51 (step S25), and then uses the imaging unit 52 to output the output image on the screen 53. The image data for the adjusted image after correction obtained by imaging is acquired (step S26).

Next, the processor digitizes the image quality data of the adjusted image after correction based on the acquired image data (step S27), and then compares the digitized image quality data of the adjusted image after correction with reference image quality data. Thus, it is determined whether or not it is necessary to correct the drive voltage of the correction target pixel (step S28). The reference image quality data is the same as in the first embodiment.

If the processor determines that correction is necessary (YES in S28), the correction coefficient α set in step S24 is reflected in the correction amount X of the drive voltage of the correction target pixel (step S29). Thereafter, a series of processes for adjusting the correction amount is completed. If the processor determines that no correction is necessary (NO in S28), the correction coefficient α need not be reflected in the correction amount X based on the voltage difference between the two pixels. The calculation for multiplying the coefficient α is not performed, the correction amount X is used as it is (step S30), and a series of processes for adjusting the correction amount is completed.

According to the correction amount adjustment in the correction amount adjustment unit 233 according to the second embodiment described above, it is possible to obtain the same operations and effects as in the first embodiment. In addition, in the first embodiment, the adjusted image after the correction coefficient α is reflected is output, the corrected image quality data is digitized based on the image data acquired again, and the necessity of correction is determined. Therefore, the necessity of correction can be determined more reliably.

(Example 3)
In the third embodiment, the correction amount adjustment unit 233 detects the image quality state of the output image from the usage time of the liquid crystal panel 10 and reflects the image quality information in the correction amount X, that is, the image quality state of the output image. This is an example in which the first detection method described above is applied to the detection of. In the third embodiment, a plurality of correction setting tables corresponding to the usage time of the liquid crystal panel 10 are prepared in advance in a LUT (lookup table) as correction setting information, and the table is selected based on the image quality information. . The LUTs of the plurality of correction setting tables are stored in a frame memory (not shown) built in the correction amount adjustment unit 233, for example.

FIG. 18 is a diagram illustrating an example of the relationship between the usage time of the liquid crystal panel, the quality of the output image, and the correction setting table. Here, as the plurality of correction setting tables, for example, the correction setting table A corresponding to the period from the initial state of the liquid crystal panel 10 to the usage time of about one year, and the usage time of about one year to about two years. The case of using two of the correction setting tables B corresponding to the period until the elapse is illustrated. However, the correction setting table is not limited to two, and may be three or more.

FIG. 19 shows an example of numerical values of the correction setting table A and the correction setting table B. Each table in FIG. 19 shows the relationship between the correction amount of the drive voltage, the drive voltage of the own pixel, and the voltage difference with the adjacent pixel. The hollow column in FIG. 19 is not corrected. Note that the numerical values shown in FIG. 19 are examples, and are not limited to these numerical values.

A series of processing for correction amount adjustment in the correction amount adjustment unit 233 according to the third embodiment will be described with reference to FIG. FIG. 20 is a flowchart illustrating a flow of processing for correction amount adjustment in the correction amount adjustment unit 233 according to the third embodiment.

20, the processor first acquires a count value of a counter (not shown) that counts the usage time of the liquid crystal panel 10 (step S31). As described above, since the image quality of the output image changes with time due to the ingress of moisture, the output image is calculated from the count value (measurement time) by counting the usage time of the liquid crystal panel 10. The degree of change in image quality over time (image quality state) can be indirectly detected. That is, by acquiring the count value of the usage time of the liquid crystal panel 10, it is possible to grasp the degree of temporal change in the image quality of the output image.

Next, the processor selects one of a plurality of correction setting tables from the LUT, that is, the correction setting table A or the correction setting table B, based on the acquired count value of usage time (step S32). As an example, if the usage time of the liquid crystal panel 10 is in an initial state, the correction amount X calculated by the correction amount calculation unit 232 is used as it is as the correction amount of the drive voltage of the correction target pixel. If the period from the initial state to the usage time of about one year has passed, the correction setting table A is selected. If the usage time has passed from about one year to the passage of about two years, the correction setting table B is selected. To do.

Next, the processor corrects the correction amount X calculated by the correction amount calculation unit 232 based on the selected correction setting table A or correction setting table B, calculates post-correction image quality data (step S33), and then Then, by comparing with the reference image quality data, it is determined whether or not it is necessary to correct the drive voltage of the pixel to be corrected (step S34). Here, the reference image quality data to be compared with the corrected image quality data is the same as in the first embodiment.

If the processor determines that correction is necessary (YES in S34), the correction setting table A or the correction setting table B selected in step S32 is reflected in the correction amount X of the drive voltage of the correction target pixel. Thus, the correction amount of the drive voltage of the correction target pixel is set (step S35), and then a series of processes for adjusting the correction amount is finished.

If the processor determines that the correction is unnecessary (NO in S34), it is not necessary to reflect the correction setting table A / correction setting table B in the correction amount X based on the voltage difference between the two pixels. The correction amount X calculated by the correction amount calculation unit 232 is used as it is (step S36), and a series of processes for adjusting the correction amount is completed.

According to the correction amount adjustment in the correction amount adjustment unit 233 according to the third embodiment described above, the usage time of the liquid crystal panel 10 is counted, and the state of the image quality of the output image is grasped from the count result, so that the liquid crystal panel 10 It is possible to detect the state of the image quality of the output image accompanying a change with time. Then, based on the state of the image quality of the output image, one of a plurality of correction setting tables prepared in advance is selected and reflected in the correction amount X of the drive voltage of the pixel to be corrected, so that the liquid crystal panel 10 changes over time. Since the drive voltage can be corrected without being affected by the change, the image quality of the output image can be improved.

In the third embodiment, the first detection method using the usage time of the liquid crystal panel 10 is applied to the detection of the image quality state of the output image. However, the second detection method may be used in combination. That is, the temperature and humidity in the usage environment of the liquid crystal panel 10 are measured, the temperature alone, the humidity alone, or both the temperature and humidity as one of the parameters, in addition to the usage time of the liquid crystal panel 10, the output image The image quality state may be detected. The combined use of the first detection method and the second detection method can further improve the detection accuracy of the image quality of the output image.

<Modification>
As mentioned above, although the technique of this indication was demonstrated based on preferable embodiment, the technique of this indication is not limited to the said embodiment. The configuration and structure of the display device described in the above embodiment are examples, and can be changed as appropriate. For example, in the above-described embodiment, the technology of the present disclosure has been described by taking a liquid crystal display device (liquid crystal panel) as an example.

That is, the image quality defect due to the horizontal electric field is a phenomenon that occurs in a display device in which pixels are two-dimensionally arranged in a matrix and display driving is performed by applying a voltage to the scanning lines and signal lines. For example, in an organic EL (Electro-Luminescence) display device, a lateral electric field disturbs the movement of electrons and holes in the organic EL element, resulting in poor image quality. In the plasma display device, the horizontal electric field affects the generation of plasma in the pixel, resulting in poor image quality. Therefore, the technology of the present disclosure can be applied to all display devices of the above method.

The display device of the present disclosure described above is a display unit (display device) of an electronic device in any field that displays a video signal input to the electronic device or a video signal generated in the electronic device as an image or a video. Can be used as Examples of the electronic device include a projection type liquid crystal display device, a television set, a notebook personal computer, a digital still camera, and a mobile terminal device such as a mobile phone. However, it is not restricted to these.

The display device of the present disclosure also includes a module-shaped one with a sealed configuration. Note that the display module may be provided with a circuit unit for inputting / outputting signals from the outside to the pixel array unit, a flexible printed circuit (FPC), and the like. Hereinafter, a projection type liquid crystal display device will be exemplified as a specific example of an electronic apparatus using the display device of the present disclosure. However, the specific example illustrated here is only an example, and is not limited to this projection type liquid crystal display device.

[Projection type liquid crystal display]
Projection type liquid crystal display devices (so-called projectors) perform color display with additive color mixing, and use liquid crystal panels for the three primary colors of light, that is, red (R), green (G), and blue (B). In general, a three-plate system is used in which images of primary colors are created with a single liquid crystal panel and then the images are combined with a prism. A liquid crystal panel used in a projection type liquid crystal display device is generally a panel having a size of about 1.0 inch. FIG. 21 schematically illustrates an optical system of a three-plate projection liquid crystal display device (projector) that is an example of the electronic apparatus of the present disclosure.

In FIG. 21, white light emitted from a light source 101 such as a white lamp is converted from P-polarized light to S-polarized light by the polarization conversion element 102, and then the illumination is made uniform by the fly-eye lens 103 to be applied to the dichroic mirror 104. Incident. Then, only a specific color component, for example, an R (red) light component is transmitted through the dichroic mirror 104, and the remaining color light components are reflected by the dichroic mirror 104. The R light component transmitted through the dichroic mirror 104 is changed in optical path by the mirror 105 and then enters the R liquid crystal panel 107R through the lens 106R.

Regarding the light component reflected by the dichroic mirror 104, for example, the G (green) light component is reflected by the dichroic mirror 108, and the B (blue) light component is transmitted through the dichroic mirror 108. The G light component reflected by the dichroic mirror 108 enters the G liquid crystal panel 107G through the lens 106G. The B light component transmitted through the dichroic mirror 108 passes through the lens 109 and is then changed in the optical path by the mirror 110. Further, after passing through the lens 111, the optical path is changed by the mirror 112, and enters the B liquid crystal panel 107B through the lens 106B. .

Although not shown in FIG. 21, polarizing plates are arranged on the incident side and the emission side of the

liquid crystal panels

107R, 107G, and 107B, respectively. As is well known, a normally white mode can be set by installing a pair of polarizing plates on the incident side and the outgoing side so that the polarization directions are perpendicular to each other (crossed Nicols), and the polarization directions are parallel to each other (parallel Nicols). You can set the normally black mode.

The R, G, and B light components that have passed through the

liquid crystal panels

107R, 107G, and 107B are incident on the cross prism 113 and are combined in the cross prism 113. Then, the light synthesized by the cross prism 113 enters the projection lens 114 and is projected on the screen (not shown) by the projection lens 114.

In the three-plate projection type liquid crystal display device having the above-described configuration, the display device (liquid crystal panel) according to the above-described embodiment can be used as the

liquid crystal panels

107R, 107G, and 107B as light modulation means (light valves). Since the display device according to the above-described embodiment can correct the drive voltage of the correction target pixel without being affected by the change over time, the image quality of the output image can be improved. Therefore, by using the display device according to the above-described embodiment as the light modulation means of the projection type liquid crystal display device, it is possible to contribute to improving the display quality of the projection type liquid crystal display device.

<Configuration that the present disclosure can take>
This indication can also take the following composition.

≪A. Display device >>
[A-1] A difference detection unit that detects a difference in drive voltage between two adjacent pixels;
A correction amount calculation unit that calculates a correction amount for correcting the drive voltage of the correction target pixel that causes a luminance change due to a difference in drive voltage detected by the difference detection unit;
A correction amount adjusting unit that adjusts the correction amount calculated by the correction amount calculating unit according to the image quality of the output image; and
A drive voltage correction unit that corrects the drive voltage of the correction target pixel based on the correction amount adjusted by the correction amount adjustment unit;
Display device.
[A-2] The correction amount adjusting unit captures an adjustment image for adjusting the correction amount, and uses the captured image data as a parameter for detecting the state of the image quality of the output image.
The display device according to [A-1].
[A-3] The correction amount adjustment unit digitizes the image quality data based on the captured image data obtained by capturing the adjusted image, sets a correction coefficient based on the image quality data, and corrects the image quality after the correction coefficient is reflected. Calculate the data, based on the post-correction image quality data obtained by this calculation, determine whether or not it is necessary to correct the drive voltage of the correction target pixel,
The display device according to [A-2] above.
[A-4] The correction amount adjustment unit determines whether or not correction is necessary by comparing the corrected image quality data obtained by calculation with the reference image quality data.
The display device according to [A-3] above.
[A-5] The correction amount adjustment unit digitizes the image quality data based on the captured image data obtained by capturing the adjusted image, sets a correction coefficient based on the image quality data, and corrects the adjustment image using the correction coefficient. The image quality data is digitized based on the captured image data obtained by capturing the corrected adjusted image, and the drive voltage of the correction target pixel is corrected based on the digitized image quality data of the corrected adjusted image. Judgment is necessary,
The display device according to [A-2] above.
[A-6] The correction amount adjustment unit determines the necessity of correction by comparing the digitized image quality data of the adjusted image with the reference image quality data.
The display device according to [A-5] above.
[A-7] The correction amount adjustment unit counts the usage time of the display panel in which the pixels are arranged, and uses the count value as a parameter for detecting the state of the image quality of the output image.
The display device according to [A-1].
[A-8] The correction amount adjustment unit has a plurality of correction setting tables corresponding to the usage time of the display panel.
The display device according to [A-7] above.
[A-9] The correction amount adjustment unit selects one of a plurality of correction setting tables based on the count value of the usage time of the display panel.
The display device according to [A-8] above.
[A-10] The correction amount adjustment unit calculates post-correction image quality data reflecting the selected correction setting table, and corrects the drive voltage of the correction target pixel based on the post-correction image quality data obtained by this calculation. Judgment is necessary,
The display device according to [A-9] above.
[A-11] The correction amount adjustment unit determines whether or not correction is necessary by comparing the corrected image quality data obtained by calculation with the reference image quality data.
The display device according to [A-10] above.
[A-12] The correction amount adjustment unit uses temperature and humidity under the usage environment of the display panel, or temperature and humidity as one of the parameters.
The display device according to any one of [A-7] to [A-11].
[A-13] The correction amount adjustment unit uses, as one of the parameters, the chromaticity of the display panel measured using a chromaticity meter or the luminance of the display panel measured using a luminance meter.
The display device according to any one of [A-7] to [A-11].

≪B. Driving method of display device >>
[B-1] A difference detection step for detecting a difference in drive voltage between two adjacent pixels;
A correction amount calculation step for calculating a correction amount for correcting the drive voltage of the correction target pixel that causes a luminance change due to the difference in the drive voltage detected in the difference detection step;
A correction amount adjusting step for adjusting the correction amount calculated in the correction amount calculating step according to the image quality of the output image; and
Based on the correction amount adjusted in the correction amount adjustment step, each process of the drive voltage correction step for correcting the drive voltage of the correction target pixel is executed.
A driving method of a display device.
[B-2] In the correction amount adjustment step, an adjustment image for adjusting the correction amount is captured, and the captured image data is used as a parameter for detecting the image quality state of the output image.
The method for driving the display device according to [B-1].
[B-3] In the correction amount adjustment step, the image quality data is digitized based on the captured image data obtained by capturing the adjusted image, the correction coefficient is set based on the image quality data, and the corrected image quality reflecting the correction coefficient Calculate the data, based on the post-correction image quality data obtained by this calculation, determine whether or not it is necessary to correct the drive voltage of the correction target pixel,
The method for driving the display device according to [B-2] above.
[B-4] In the correction amount adjustment step, it is determined whether or not correction is necessary by comparing the corrected image quality data obtained by calculation with the reference image quality data.
The method for driving the display device according to [B-3] above.
[B-5] In the correction amount adjustment step, the image quality data is digitized based on the captured image data obtained by capturing the adjusted image, a correction coefficient is set based on the image quality data, and the adjustment image is corrected using the correction coefficient. The image quality data is digitized based on the captured image data obtained by capturing the corrected adjusted image, and the drive voltage of the correction target pixel is corrected based on the digitized image quality data of the corrected adjusted image. Judgment is necessary,
The method for driving the display device according to [B-2] above.
[B-6] In the correction amount adjustment step, it is determined whether or not correction is necessary by comparing the digitized image quality data of the adjusted image with the reference image quality data.
The method for driving the display device according to [B-5] above.
[B-7] In the correction amount adjustment step, the usage time of the display panel in which the pixels are arranged is counted, and the count value is used as a parameter for detecting the state of the image quality of the output image.
The method for driving the display device according to [B-1].
[B-8] The correction amount adjustment step includes a plurality of correction setting tables corresponding to the usage time of the display panel.
The method for driving the display device according to [B-7] above.
[B-9] In the correction amount adjustment step, one of a plurality of correction setting tables is selected based on the count value of the usage time of the display panel.
The method for driving the display device according to [B-8].
[B-10] In the correction amount adjustment step, the post-correction image quality data reflecting the selected correction setting table is calculated, and based on the post-correction image quality data obtained by this calculation, the correction of the drive voltage of the correction target pixel is performed. Judgment is necessary,
The method for driving the display device according to [B-9].
[B-11] In the correction amount adjustment step, whether or not correction is necessary is determined by comparing the corrected image quality data obtained by calculation with the reference image quality data.
The method for driving a display device according to [B-10] above.
[B-12] In the correction amount adjustment step, temperature and humidity under the use environment of the display panel, or temperature and humidity are used as one of the parameters.
The method for driving a display device according to any one of [B-7] to [B-11].
[B-13] In the correction amount adjustment step, the chromaticity of the display panel measured using a chromaticity meter or the luminance of the display panel measured using a luminance meter is used as one of the parameters.
The method for driving a display device according to any one of [B-7] to [B-11].

≪C. Electronic equipment >>
[C-1] A difference detection unit that detects a difference in drive voltage between two adjacent pixels;
A correction amount calculation unit that calculates a correction amount for correcting the drive voltage of the correction target pixel that causes a luminance change due to a difference in drive voltage detected by the difference detection unit;
A correction amount adjusting unit that adjusts the correction amount calculated by the correction amount calculating unit according to the image quality of the output image; and
A drive voltage correction unit that corrects the drive voltage of the correction target pixel based on the correction amount adjusted by the correction amount adjustment unit;
An electronic device having a display device.
[C-2] The correction amount adjustment unit captures an adjustment image for adjusting the correction amount, and uses the captured image data as a parameter for detecting the state of the image quality of the output image.
The electronic device according to [C-1] above.
[C-3] The correction amount adjusting unit digitizes the image quality data based on the captured image data obtained by capturing the adjusted image, sets a correction coefficient based on the image quality data, and corrects the image quality after the correction coefficient is reflected. Calculate the data, based on the post-correction image quality data obtained by this calculation, determine whether or not it is necessary to correct the drive voltage of the correction target pixel,
The electronic device according to [C-2] above.
[C-4] The correction amount adjustment unit determines whether or not correction is necessary by comparing the corrected image quality data obtained by the calculation with the reference image quality data.
The electronic device according to [C-3] above.
[C-5] The correction amount adjustment unit digitizes the image quality data based on the captured image data obtained by capturing the adjusted image, sets a correction coefficient based on the image quality data, and corrects the adjusted image using the correction coefficient. The image quality data is digitized based on the captured image data obtained by capturing the corrected adjusted image, and the drive voltage of the correction target pixel is corrected based on the digitized image quality data of the corrected adjusted image. Judgment is necessary,
The electronic device according to [C-2] above.
[C-6] The correction amount adjustment unit determines whether or not correction is necessary by comparing the image quality data of the adjusted image after correction with the reference image quality data.
The electronic device according to [C-5] above.
[C-7] The correction amount adjustment unit counts the usage time of the display panel in which the pixels are arranged, and uses the count value as a parameter for detecting the image quality state of the output image.
The electronic device according to [C-1] above.
[C-8] The correction amount adjustment unit has a plurality of correction setting tables corresponding to the usage time of the display panel.
The electronic device according to [C-7] above.
[C-9] The correction amount adjustment unit selects one of a plurality of correction setting tables based on the count value of the usage time of the display panel.
The electronic device according to [C-8] above.
[C-10] The correction amount adjustment unit calculates post-correction image quality data reflecting the selected correction setting table, and corrects the drive voltage of the correction target pixel based on the post-correction image quality data obtained by the calculation. Judgment is necessary,
The electronic device according to [C-9] above.
[C-11] The correction amount adjustment unit determines whether or not correction is necessary by comparing the corrected image quality data obtained by calculation with the reference image quality data.
The electronic device according to [C-10] above.
[C-12] The correction amount adjustment unit uses temperature and humidity under the usage environment of the display panel, or temperature and humidity as one of the parameters.
The electronic device according to any one of [C-7] to [C-11].
[C-13] The correction amount adjustment unit uses, as one of the parameters, the chromaticity of the display panel measured using a chromaticity meter or the luminance of the display panel measured using a luminance meter.
The electronic device according to any one of [C-7] to [C-11].

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device, 2 ... Pixel, 10 ... Liquid crystal panel, 20 ... Video signal processing circuit, 21 ... A / D * PLL part, 22 ... Video signal conversion part, 23 ... Digital signal processing unit, 24 ... Sample hold unit, 25 ... Image memory, 26 ... Control unit, 231 ... Adjacent pixel voltage difference calculation unit, 232 ... Correction amount calculation , 233... Correction amount adjustment unit, 234... Correction amount addition unit

Claims

A difference detection unit for detecting a difference in driving voltage between two adjacent pixels;
A correction amount calculation unit that calculates a correction amount for correcting the drive voltage of the correction target pixel that causes a luminance change due to a difference in drive voltage detected by the difference detection unit;
A correction amount adjusting unit that adjusts the correction amount calculated by the correction amount calculating unit according to the image quality of the output image; and
A drive voltage correction unit that corrects the drive voltage of the correction target pixel based on the correction amount adjusted by the correction amount adjustment unit;
Display device.
The correction amount adjustment unit captures an adjustment image for adjusting the correction amount, and uses the captured image data as a parameter for detecting the state of the image quality of the output image.
The display device according to claim 1.
The correction amount adjustment unit digitizes the image quality data based on the captured image data obtained by capturing the adjusted image, sets a correction coefficient based on the image quality data, calculates post-correction image quality data reflecting the correction coefficient, Based on the post-correction image quality data obtained by this calculation, it is determined whether or not it is necessary to correct the drive voltage of the correction target pixel.
The display device according to claim 2.
The correction amount adjustment unit determines whether or not correction is necessary by comparing the corrected image quality data obtained by calculation with reference image quality data.
The display device according to claim 3.
The correction amount adjustment unit digitizes the image quality data based on the captured image data obtained by capturing the adjustment image, sets a correction coefficient based on the image quality data, corrects and outputs the adjustment image using the correction coefficient, The image quality data is digitized based on the captured image data obtained by capturing the adjusted image after correction, and the necessity of correcting the drive voltage of the correction target pixel is determined based on the digitized image quality data of the adjusted image after correction. ,
The display device according to claim 2.
The correction amount adjustment unit determines whether or not correction is necessary by comparing the digitized image quality data of the corrected image with reference image quality data.
The display device according to claim 5.
The correction amount adjustment unit counts the usage time of the display panel in which pixels are arranged, and uses the count value as a parameter for detecting the state of the image quality of the output image.
The display device according to claim 1.
The correction amount adjustment unit has a plurality of correction setting tables corresponding to the usage time of the display panel.
The display device according to claim 7.
The correction amount adjustment unit selects one of a plurality of correction setting tables based on the count value of the usage time of the display panel.
The display device according to claim 8.
The correction amount adjustment unit calculates post-correction image quality data reflecting the selected correction setting table, and determines whether or not the drive voltage of the correction target pixel needs to be corrected based on the post-correction image quality data obtained by the calculation. ,
The display device according to claim 9.
The correction amount adjustment unit determines whether or not correction is necessary by comparing the corrected image quality data obtained by calculation with reference image quality data.
The display device according to claim 10.
The correction amount adjustment unit uses temperature and humidity under the usage environment of the display panel, or temperature and humidity as one of the parameters.
The display device according to claim 7.
The correction amount adjustment unit uses, as one of the parameters, the chromaticity of the display panel measured using a color chromaticity meter, or the luminance of the display panel measured using a luminance meter.
The display device according to claim 7.
A difference detection step of detecting a difference in drive voltage between two adjacent pixels;
A correction amount calculation step for calculating a correction amount for correcting the drive voltage of the correction target pixel that causes a luminance change due to the difference in the drive voltage detected in the difference detection step;
A correction amount adjusting step for adjusting the correction amount calculated in the correction amount calculating step according to the image quality of the output image; and
Based on the correction amount adjusted in the correction amount adjustment step, each process of the drive voltage correction step for correcting the drive voltage of the correction target pixel is executed.
A driving method of a display device.
A difference detection unit for detecting a difference in driving voltage between two adjacent pixels;
A correction amount calculation unit that calculates a correction amount for correcting the drive voltage of the correction target pixel that causes a luminance change due to a difference in drive voltage detected by the difference detection unit;
A correction amount adjusting unit that adjusts the correction amount calculated by the correction amount calculating unit according to the image quality of the output image; and
A drive voltage correction unit that corrects the drive voltage of the correction target pixel based on the correction amount adjusted by the correction amount adjustment unit;
An electronic device having a display device.