CN111727471A

CN111727471A - Display device, driving method of display device, and electronic apparatus

Info

Publication number: CN111727471A
Application number: CN201980013365.9A
Authority: CN
Inventors: 山田泰弘
Original assignee: Sony Semiconductor Solutions Corp
Current assignee: Sony Semiconductor Solutions Corp
Priority date: 2018-02-23
Filing date: 2019-02-01
Publication date: 2020-09-29
Anticipated expiration: 2039-02-01
Also published as: WO2019163485A1; CN111727471B

Abstract

The display device of the present disclosure includes: a difference detecting unit for detecting a difference in driving voltages between two adjacent pixels; a correction amount calculation unit that calculates a correction amount for correcting the drive voltage of a pixel to be corrected, the pixel to be corrected having luminance change due to the difference in the drive voltage detected by the difference detection unit; a correction amount adjustment unit that adjusts the correction amount calculated by the correction amount calculation unit according to the image quality of the output image; and a drive voltage correction unit that corrects the drive voltage of the pixel to be corrected based on the correction amount adjusted by the correction amount adjustment unit.

Description

Display device, driving method of display device, and electronic apparatus

Technical Field

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

Background

In a display device such as a liquid crystal display device, a so-called lateral electric field is generated between two adjacent pixels, which are signal boundary portions where a potential difference is generated between video signals supplied to the respective pixels. Due to the transverse electric field, the electric field applied to the electrode of each pixel is disturbed, and image quality is deteriorated due to the influence of the electric field disturbance. The phenomenon of poor image quality is characterized by a difference in driving voltage (voltage difference) based on a video signal between two pixels, which causes a difference in color density between the two pixels.

Conventionally, in response to an image quality defect caused by a lateral electric field between two adjacent pixels, a difference in drive voltage between the two adjacent pixels is detected, a correction amount for correcting the drive voltage of a correction target pixel, which is a pixel having luminance variation due to the difference, is calculated, and the drive voltage of the correction target pixel is corrected based on the correction amount (see, for example, patent document 1).

Patent document 1: japanese laid-open patent publication No. 2009-237366

Disclosure of Invention

In the conventional technique described in patent document 1, assuming a state of the display device after a certain time-dependent change, a correction amount for correcting a drive voltage to a target pixel is set to a fixed value. Therefore, the image quality is degraded due to overcorrection in an initial state in which the image quality does not change with time, or the image quality of the output image is degraded due to undercorrection in a state in which the image quality changes with time more than an assumed state.

An object of the present disclosure is to provide a display device, a method of driving the display device, and an electronic apparatus having the display device, which can improve the image quality of an output image by correcting the drive voltage of a pixel to be corrected without being affected by a change over time.

To achieve the above object, a display device of the present disclosure includes:

a difference detecting unit for detecting a difference in driving voltages between two adjacent pixels;

a correction amount calculation unit that calculates a correction amount for correcting the drive voltage of a pixel to be corrected, the pixel to be corrected having luminance change due to the difference in the drive voltage detected by the difference detection unit;

a correction amount adjustment unit that adjusts the correction amount calculated by the correction amount calculation unit according to the image quality of the output image; and

and a drive voltage correction unit that corrects the drive voltage of the pixel to be corrected based on the correction amount adjusted by the correction amount adjustment unit.

Further, the driving method of the display device of the present disclosure to achieve the above object performs the following processes:

a difference detection step of detecting a difference in drive voltage between two adjacent pixels;

a correction amount calculation step of calculating a correction amount by which the driving voltage of the correction target pixel, which is a pixel having luminance variation due to the difference in the driving voltage detected in the difference detection step, is corrected;

a correction amount adjustment step of adjusting the correction amount calculated in the correction amount calculation step, based on the image quality of the output image; and

and a drive voltage correction step of correcting the drive voltage of the correction target pixel based on the correction amount adjusted in the correction amount adjustment step.

In order to achieve the above object, an electronic device of the present disclosure includes a display device including:

Drawings

Fig. 1 is a block diagram showing an outline of a system configuration of a liquid crystal display device to which the technique of the present disclosure is applied.

Fig. 2A is a block diagram showing an example of a configuration of an active matrix liquid crystal panel, and fig. 2B is an equivalent circuit diagram showing 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 portion of fig. 3A.

FIG. 4A is a diagram showing a state of moisture in a liquid crystal layer in an initial state of a liquid crystal panel, FIG. 4B is a diagram showing an example of a pixel potential in the initial state, and FIG. 4C is a diagram showing a video signal V in the initial state_sig-a graph of the characteristics of the transmittance T.

FIG. 5A is a diagram showing a state of moisture in a liquid crystal layer in a moisture-absorbed state of a liquid crystal panel, FIG. 5B is a diagram showing an example of a pixel potential in the moisture-absorbed state, and FIG. 5C is a diagram showing a video signal V in the moisture-absorbed state_sig-a graph of the characteristics of the transmittance T.

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

Fig. 7 is a block diagram showing an example of the configuration of the inter-pixel voltage difference calculation unit in the digital signal processing unit.

Fig. 8 is a block diagram showing 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 of a display image with respect to an input video signal and an image of a center line thereof.

Fig. 10A is a diagram showing a display image after the occurrence of image quality failure, fig. 10B is a diagram showing a voltage difference signal obtained from a voltage difference between the present pixel and the (N + 1) th pixel, and fig. 10C is a diagram showing a voltage difference signal obtained from a voltage difference between the present pixel and the (N-1) th pixel.

Fig. 11 is a diagram showing an example of correction setting information to be referred to when calculating the correction amount.

Fig. 12 is a diagram showing an example of a state in which the image quality of an output image is directly detected by an imaging unit disposed in the projector.

Fig. 13 is a flowchart showing a flow of processing for correction amount adjustment in the correction amount adjustment section of embodiment 1.

Fig. 14 is a diagram showing an example of the relationship between the use time of the liquid crystal panel, the state of the image quality of the output image, and the correction coefficient α.

Fig. 15 is an explanatory diagram of threshold values and image quality setting ranges of criteria for determining whether or not the drive voltage of the correction target pixel needs to be corrected.

Fig. 16 is a diagram showing an example of correction setting information after the correction coefficient α is fed back.

Fig. 17 is a flowchart showing a flow of processing for correction amount adjustment in the correction amount adjustment section of embodiment 2.

Fig. 18 is a diagram showing an example of the relationship between the usage time of the liquid crystal panel, the state of the image quality of the output image, and the correction setting table.

Fig. 19 is a diagram showing an example of numerical values relating to the correction setting table a and the correction setting table B.

Fig. 20 is a flowchart showing a flow of processing for correction amount adjustment in the correction amount adjustment section of embodiment 3.

Fig. 21 is a schematic configuration diagram showing an optical system of a three-plate projection type liquid crystal display device (projector) as an example of the electronic apparatus of the present disclosure.

Detailed Description

Hereinafter, a mode for carrying out the technique of the present disclosure (hereinafter referred to as "embodiment") will be described in detail with reference to the drawings. The technique of the present disclosure is not limited to the embodiments, and various numerical values and the like in the embodiments are examples. In the following description, the same elements or elements having the same function are denoted by the same reference numerals, and redundant description thereof is omitted. The following procedure is described.

1. Display device, driving method of display device, and overall description of electronic apparatus of the present disclosure

2. Display device to which the technology of the present disclosure is applied

2-1 System construction example

2-2 structural example of liquid crystal panel

2-3 Circuit example of Pixel

2-4 structural example of liquid crystal panel

2-5. time-dependent change in picture quality due to leakage between pixels

3. Embodiments of the present disclosure (digital signal processing section)

3-1. calculating part of voltage difference between adjacent pixels

3-2 correction amount calculating part

3-3 correction amount addition unit

3-3-1. embodiment 1 (example of detecting the state of image quality from the result of capturing an output image)

3-3-2 example 2 (modification of example 1)

3-3-3. embodiment 3 (example of detecting the state of image quality depending on the time of use of liquid crystal panel)

4. Modification example

5. Electronic apparatus (example of projection type liquid crystal display device) of the present disclosure

6. Constitution that the present disclosure can adopt

< description of the display device, the method of driving the display device, and the electronic apparatus of the present disclosure >

In the display device, the method for driving the display device, and the electronic apparatus of the present disclosure, the correction amount adjustment section may be configured as follows: an adjustment image for adjustment of the correction amount is captured, and the captured image data is used as a parameter for detecting the state of the image quality of the output image.

In the display device, the method for driving the display device, and the electronic apparatus of the present disclosure including the above-described preferred configurations, the correction amount adjustment unit may be configured as follows: image quality data is digitized based on captured image data obtained by capturing an adjustment image, a correction coefficient is set based on the image quality data, corrected image quality data in which the correction coefficient is reflected is calculated, and whether or not the drive voltage of a pixel to be corrected needs to be corrected is determined based on the corrected image quality data obtained by the calculation. In this case, it is preferable that the corrected image quality data obtained by the calculation is compared with the reference image quality data to determine whether or not the correction is necessary.

Alternatively, in the display device, the method for driving the display device, and the electronic apparatus of the present disclosure including the above preferred configurations, the correction amount adjustment section may be configured as follows: image quality data is digitized based on captured image data obtained by capturing an adjustment image, a correction coefficient is set based on the image quality data, and the adjustment image is corrected using the correction coefficient and output. Then, image quality data is digitized based on the captured image data of the corrected adjustment image, and it is determined whether or not the drive voltage of the pixel to be corrected needs to be corrected based on the digitized image quality data of the corrected adjustment image. In this case, it is preferable that the corrected image quality data converted into numerical values is compared with the reference image quality data to determine whether correction is necessary.

Alternatively, in the display device, the method for driving the display device, and the electronic apparatus of the present disclosure including the above preferred configurations, the correction amount adjustment unit may be configured as follows: the use time of a display panel in which pixels are arranged is counted, and the count value is used as a parameter for detecting the state of the image quality of an output image. The correction amount adjustment unit may be configured as follows: the display device has a plurality of correction setting tables corresponding to the use time of the display panel, and selects one of the plurality of correction setting tables based on the count value of the use time of the display panel.

In the display device, the method for driving the display device, and the electronic apparatus of the present disclosure including the above preferred configurations, the correction amount adjustment unit may be configured as follows: the corrected image quality data reflecting the selected correction setting table is calculated, and whether or not the drive voltage of the pixel to be corrected needs to be corrected is determined based on the corrected image quality data obtained by the calculation. In this case, it is preferable that the corrected image quality data obtained by the calculation is compared with the reference image quality data to determine whether or not the correction is necessary.

In addition, in the display device, the method of driving the display device, and the electronic apparatus of the present disclosure including the above-described preferred configurations, the correction amount adjustment section can adopt a configuration in which temperature, humidity, or both of the temperature and the humidity in the usage environment of the display panel are used as one of the parameters. Alternatively, a configuration may be adopted in which the chromaticity of the display panel measured by a color colorimeter or the luminance of the display panel measured by a luminance meter is 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 technique of the present disclosure is applied will be described with reference to a liquid crystal display device as an example.

Liquid crystal display devices are classified into transmissive type, reflective type and semi-transmissive type in a display mode. As a silicon material used for a Thin Film Transistor (TFT) used for a pixel, amorphous silicon (amorphous semiconductor) or polycrystalline silicon (polycrystalline semiconductor) is often used in a transmissive liquid crystal display device. In a reflective liquid crystal display device, single crystal silicon is often used. In addition, polysilicon is classified into High Temperature Polysilicon (HTPS) that forms a thin film in a High Temperature environment at 1000 degrees Celsius or Higher (HTPS) and Low Temperature Polysilicon (LTPS) that forms a thin film in a Low Temperature environment at 600 degrees Celsius or Lower (LTPS).

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 for forming a pixel. Generally, a glass substrate is used for an amorphous silicon-transmissive liquid crystal panel and a low-temperature polysilicon-transmissive liquid crystal panel, a quartz substrate is used for a high-temperature polysilicon-transmissive liquid crystal panel, and a silicon substrate is used for a single crystal silicon-reflective liquid crystal panel.

Liquid crystal materials mainly used for manufacturing products have TN mode, VA mode and IPS mode, and TFT technology has high-temperature polycrystalline silicon, low-temperature polycrystalline silicon and amorphous silicon (a-Si). In many liquid crystal panels for projection type liquid crystal display devices (projectors), VA mode is selected for liquid crystal materials, and HTPS (high temperature poly-silicon) is selected for TFT process (so-called HTPS — liquid crystal panel). In a large number of small and medium-sized direct-view liquid crystal panels of about 3 inches to 10 inches such as smart phones, VA mode or IPS mode is selected for a liquid crystal material, and LTPS (low temperature polysilicon) is selected for a TFT process (so-called LTPS — liquid crystal panel). In a large-sized direct-view liquid crystal panel of 10 inches or more such as a television receiver, a personal computer, or the like, VA mode or IPS mode is often selected for a liquid crystal material, and amorphous silicon (so-called aSi-liquid crystal panel) is often selected for a TFT process.

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

[ example of System construction ]

First, a system configuration of a liquid crystal display device to which the technique of the present disclosure is applied will be described with reference to fig. 1. Fig. 1 is a block diagram showing an outline of a system configuration of a liquid crystal display device to which the technique of the present disclosure is applied. The liquid crystal display device 1 of the present application example includes a liquid crystal panel 10 and a video signal processing circuit 20. The configuration of the liquid crystal panel 10 will be described in detail 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 and hold unit 24, an image memory 25, and a control unit 26 perform signal processing for converting an input video signal into a signal format suitable for display on the liquid crystal panel 10.

In the video signal processing circuit 20, when the input video signal is an analog signal, the a/D/PLL unit 21 performs processing for converting the input video signal into pixel data in a digital format and processing for realizing phase synchronization. When the input video signal is a digital signal, a digital/interface unit is provided instead of the a/D/PLL unit 21. The digital/interface section is a processing device: an input video signal of a data transmission technology represented by a DVI (Digital Visual Interface) system or an HDMI (registered trademark) (HDMI: High-Definition Multimedia Interface) system is converted into a Digital format.

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) suitable for the number of pixels and the clock frequency of the liquid crystal panel 10. For example, when the liquid crystal panel 10 is a color liquid crystal panel, the video signal converter 22 converts the composite signal or the like into an RGB separate signal suitable for driving the color liquid crystal panel, and outputs the RGB separate signal to the digital signal processor 23 together with the video signal.

The digital signal processing section 23 performs processing such as contrast adjustment and crosstalk correction on the pixel data (primary color data) output from the video signal conversion section 22. The digital signal processing section 23 applies the technique of the present disclosure. This specific embodiment will be described later.

The sample-and-hold section 24 performs sample-and-hold processing on the pixel data (primary color data) subjected to the signal processing by the digital signal processing section 23, for use in driving the liquid crystal panel 10. The digital signal processing section 23 may include the function of the sample hold section 24.

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

The control Unit 26 is constituted by a processor such as an MPU (Micro Processing Unit), for example, and the control Unit 26 controls the video signal conversion Unit 22, the digital signal Processing Unit 23, the sample hold Unit 24, and the like in the entire liquid crystal display device 1. 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 corresponding to the RGB separate signals.

[ example of liquid Crystal Panel ]

Next, an example of the structure 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 system will be described as an example. Fig. 2A shows an example of the structure of the active matrix liquid crystal panel 10.

As shown in fig. 2A, the liquid crystal panel 10 is configured as follows: the liquid crystal display device includes a pixel array section 11 in which a plurality of pixels 2 including liquid crystal elements are two-dimensionally arranged in a matrix, and a peripheral circuit section arranged around the pixel array section 11. The peripheral circuit unit is constituted by a vertical driving unit 12, a horizontal driving unit 13, and the like, and is integrated on the same substrate as the pixel array unit 11 to drive each pixel 2 of the pixel array unit 11. The liquid crystal panel 10 includes a terminal portion (not shown) for inputting or outputting a signal from or to the outside. The terminal portion is connected to an external board (not shown) via a flexible board, for example, and the video signal processing circuit 20 is mounted on the external board.

In the pixel array section 11, the scanning lines 31 are arranged in a matrix form for the pixel arrangement₁～31_m(hereinafter sometimes collectively referred to as "scanning lines 31") are wired for each pixel row in the row direction. In addition, the signal line 32₁～32_n(hereinafter, sometimes collectively referred to as "signal lines 32") are wired in a column direction for each pixel column. In other words, the scanning line 31₁～31_mAnd signal line 32₁～32_nThe pixels 2 are formed in matrix wiring at intersections thereof.

In the peripheral circuit section, the vertical driving section 12 is provided so as to be in contact with the scanning lines 31₁～31_mAre connected. The vertical driving section 12 is constituted by a shift register or the like, and inputs a scanning signal for driving when writing a video signal into the pixel 2 to the scanning line 31₁～31_m。

The horizontal driving part 13 is arranged to be connected with the signal line 32₁～32_nAre connected. The horizontal driving unit 13 reads a video signal for writing to each pixel 2 in a pixel row (selected row) selected by the vertical driving unit 12 from the external video signal processing circuit 20 and outputs the video signal to the signal line 32₁～32_n。

The driving method for writing the video signal into the pixels 2 may be dot-sequential driving in which the video signal is written in pixel units to the respective pixels 2 in the selected row, or line-sequential driving in which the video signal is written in pixel row units to the respective pixels 2 in the selected row.

[ example of Circuit of Pixel ]

Next, a circuit example of the pixel 2 will be described. Fig. 2B shows an example of a circuit configuration of the pixel 2. As shown in the equivalent circuit diagram of fig. 2, the pixel 2 is a configuration having a liquid crystal element LC, a capacitance element C, and a pixel transistor Tr.

One electrode of the liquid crystal element LC is an independent electrode (a 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 capacitive element C. The other electrode of the liquid crystal element LC is an electrode (counter electrode described later) common to all the pixels 2, and is grounded, for example.

The capacitor element C is an element for stabilizing the accumulated charge of the liquid crystal element LC. One end of the capacitance 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 capacitor element C is connected to the capacitor line 33.

The pixel transistor Tr is a switching element for writing a video signal into the liquid crystal element LC, and is formed of 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 element C, and the other electrode (drain/source electrode) connected to the signal line 32.

[ example of liquid Crystal Panel ]

Next, an example of the structure of the liquid crystal panel 10 will be described. Fig. 3A is an exploded perspective view showing an example of the structure of the liquid crystal panel 10, and fig. 3B is an enlarged view of a main portion of fig. 3A.

The liquid crystal panel 10 has the following panel structure: a first substrate 41 and a second substrate 42, which are transparent substrates such as glass substrates, are disposed to face each other with a predetermined gap therebetween, and a liquid crystal material is sealed between the first substrate 41 and the second substrate 42 to form a liquid crystal layer 43. The liquid crystal panel 10 includes a polarizer 44 and a polarizer 45 facing each other with the first substrate 41 and the second substrate 42 interposed therebetween. The polarizing plate 44 and the polarizing plate 45 are arranged such 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. A counter electrode (not shown) is formed in the transparent conductive film 46 so as to be shared with all the pixels 2 of the pixel array section 11. Thus, the first substrate 41 is sometimes referred to as a counter substrate. The opposite electrode is the other electrode of the liquid crystal element LC shown in fig. 2B. Further, a transparent conductive film 47 is formed on the second substrate 42. A pixel electrode 48 is formed on the transparent conductive film 47 so as to be independent 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 formed of a Thin Film Transistor (TFT) is formed on the second substrate 42. Thus, the second substrate 42 is sometimes referred to as a TFT substrate. A scanning line 31 in which a gate electrode of the pixel transistor Tr is connected to each pixel row and a signal line 32 in which one electrode (source/drain electrode) of the pixel transistor Tr is connected to each pixel column are also wired on the second substrate 42. Here, the i-th scanning line 31 is illustrated_iAnd the i +1 th row scanning line 31_i+1And the J-th column signal line 32_jAnd the j +1 th row scanning line 31_j+1。

In the liquid crystal panel 10 having the above-described configuration, among the liquid crystal molecules in the liquid crystal layer 43, only the

liquid crystal molecules

43a and 43b sandwiched between the two electrodes of the pixel electrode and the counter electrode change their arrangement under the influence of the lateral electric field between the pixel electrode and the counter electrode, and function as a liquid crystal shutter for one pixel. Here, the lateral electric field is an electric field generated between the pixel electrodes 48 (or between the signal lines 32) of two adjacent pixels as shown in fig. 3B due to a potential difference of the video signals supplied to the two adjacent pixels.

Further, a liquid crystal panel (liquid crystal display device) has a perfect vertical alignment type and an oblique alignment type. The perfect Vertical Alignment type is called a VA (Vertical Alignment) type, and liquid crystal molecules of the liquid crystal layer 43 are aligned to be perpendicular to the substrates (the first substrate 41 and the second substrate 42) through an Alignment film (not shown) in a state where no voltage is applied to the electrodes corresponding to the pixels. That is, the tilt angle θ of the

liquid crystal molecules

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

On the other hand, the tilt alignment type aligns liquid crystal molecules of the liquid crystal layer 43 obliquely with respect to a normal direction of the substrate by an alignment film not shown in the figure in a state where no voltage is applied to an electrode corresponding to a pixel, and becomes an alignment azimuth substantially horizontal to the substrate in a state where a voltage is applied. 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 provided, the liquid crystal panel 10 is inclined in a predetermined direction when viewed from the front (substrate normal direction). In this state, if a voltage is applied to an electrode corresponding to a pixel, the falling direction (orientation azimuth) is determined by the pretilt. Since the alignment direction of the liquid crystal molecules is determined to be one direction, the transmitted light in the pixel becomes uniform, and favorable image display can be performed.

[ time-dependent change in image quality due to inter-pixel leakage ]

In the liquid crystal panel 10, if moisture enters the liquid crystal layer 43 from a seal portion where the liquid crystal material is sealed between the first substrate 41 and the second substrate 42 in an environment of high temperature and humidity, so-called inter-pixel leakage occurs in which a leakage current flows between two adjacent pixels. Further, if inter-pixel leakage occurs, the potential difference between adjacent pixels becomes small, and therefore the image quality of an output image, such as a character appearing thick, changes with time.

Fig. 4A shows a state of moisture in the liquid crystal layer 43 in an initial state of the liquid crystal panel 10, fig. 4B shows an example of a pixel potential in the initial state, and fig. 4C shows a video signal V in the initial state_sig-a characteristic of the transmittance T. Here, a case of normally black is exemplified. Fig. 4B illustrates a case where, among five adjacent pixels pix1 to pix5, the potential of the center pixel pix3 is 0V, and the potentials of the other four pixels pix1, pix2, pix4, and pix5 are 3V. In the initial state, no inter-pixel leakage occurs. Therefore, as shown in fig. 4C, the transmittance T of the pixel pix3 is 0%, and the transmittance T of each of the pixels pix1, pix2, pix4, and pix5 is, for example, about 60%.

Fig. 5A shows a state of moisture in the liquid crystal layer 43 in a moisture absorption state (i.e., a state in which moisture is immersed in the liquid crystal layer 43) of the liquid crystal panel 10, fig. 5B shows an example of a pixel potential in the moisture absorption state, and fig. 5C shows a state of moisture absorptionImage signal V in wet state_sig-a characteristic of the transmittance T. As shown in fig. 5A, if moisture enters the liquid crystal layer 43 in a high-temperature and high-humidity environment, a leakage path is formed between pixels and a leakage current flows as shown in fig. 5B.

Further, since inter-pixel leakage occurs, for example, the potential of the middle pixel pix3, which is 0V in the initial state, is 1V, the potentials of the pixels pix2 and pix4, which are 3V in the initial state, are 2.5V, and the potentials of the pixels pix1 and pix5 are 2.9V. That is, the potential difference between the pixel pix3 of 3V in the initial state and the pixels pix2 and pix4 adjacent to both sides becomes 1.5V in the hygroscopic state.

Thus, as shown in fig. 5C, the transmittance T of each of the pixels pix2 and pix4 is, for example, about 25%, and the transmittance T of each of the pixels pix1 and pix5 is, for example, about 55%. That is, if the potential difference between adjacent pixels is small due to the inter-pixel leakage, the difference in transmittance T is small, and therefore, when characters or the like are displayed, the definition of the characters such as the characters appearing thick is reduced, and the image quality of the output image changes with time.

In the above description, the case where the inter-pixel leakage occurs due to moisture is taken as an example, and the potential difference between adjacent pixels is small, and the image quality of the output image changes with time. For example, a leak between pixels may occur due to a change in domain (disturbance in alignment of liquid crystal molecules), gap (distance between two adjacent pixels), liquid crystal composition, pretilt angle (inclination angle of liquid crystal molecules with respect to a substrate), or the like, and the potential difference between adjacent pixels may decrease.

< embodiments of the present disclosure >

Here, in the embodiment of the present disclosure, in the digital signal processing unit 23 shown in fig. 1, a difference in driving voltage between two adjacent pixels is detected, and a correction amount for correcting the driving voltage of a correction target pixel, which is a pixel having luminance change due to the difference in driving voltage, is calculated. Then, the drive voltage of the correction target pixel is corrected based on the correction amount calculated by the image quality adjustment of the output image.

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

The digital signal processing unit 23 of the present embodiment is configured to include, as a correction processing unit that performs correction processing on a video signal: a voltage difference between adjacent pixels calculating section 231, a correction amount calculating section 232, a correction amount adjusting section 233, and a correction amount adding section 234.

The inter-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 may be configured to be executed by software by a processor such as an MPU interpreting and executing a program for realizing each function. However, the present invention is not limited to the configuration executed by software, and each functional unit may be configured as hardware.

That is, in the driving method (signal processing method) of the present embodiment, the inter-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 can be used as a difference amount detection step, a correction amount calculation step, a correction amount adjustment step, and a driving voltage correction step.

The adjacent pixel voltage difference calculation unit 231 is a difference detection unit that detects a difference in drive voltage between two adjacent pixels. The inter-pixel voltage difference calculation unit 231 performs the following processing: a difference between a drive voltage supplied from the video signal input from the video signal conversion unit 22 of fig. 1 to the pixel to be corrected (hereinafter referred to as "correction target pixel") and a drive voltage supplied to a pixel adjacent to the correction target pixel (hereinafter referred to as "adjacent pixel"), that is, a difference between adjacent pixels, is calculated.

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

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

The correction amount addition unit 234 adds the correction amount in which the image quality of the output image is reflected by the correction amount adjustment unit 233 to the video signal data (drive voltage information) supplied to the correction target pixel, and outputs the addition result as an output video signal to the sample hold unit 24 in fig. 1. 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.

[ calculating part of Voltage Difference between adjacent pixels ]

Next, a specific configuration of the inter-pixel voltage difference calculation unit 231 in the digital signal processing unit 23 will be described with reference to fig. 7. Fig. 7 is a block diagram showing an example of the configuration of the inter-pixel voltage difference calculation unit 231.

The digital signal processing unit 23 is configured to perform correction not only in the horizontal scanning direction but also in the vertical scanning direction, and thus can perform delay control of the input video signal. That is, the digital signal processing unit 23 includes a sync separation unit 235 and a delay control unit 236 in addition to the adjacent inter-pixel voltage difference calculation unit 231.

The sync separator 235 separates a sync signal from a video signal. When the input video signal is a black-and-white (white-and-black) video signal, a signal obtained by separating the synchronization signal from the video signal is a luminance signal. In addition, when the input video signal is a color video signal, a signal obtained by separating the synchronization signal from the video signal includes luminance information and color information. Examples of the color video signal include an RGB signal.

The delay control unit 236 delays the synchronizing signal separated from the input video signal by the sync separation unit 235, outputs the delayed synchronizing signal to the adjacent pixel voltage difference calculation unit 231, and outputs the delayed synchronizing signal to the sample hold unit 24 in fig. 1 as an output synchronizing signal.

In the digital signal processing unit 23 capable of performing delay control of the input video signal, the inter-pixel voltage difference calculation unit 231 is configured by a memory control unit 2311, a horizontal voltage difference calculation unit 2312, and a vertical voltage difference calculation unit 2313.

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

The horizontal direction voltage difference calculation unit 2312 performs a process of detecting voltage differences of drive voltages supplied to the present pixel and the adjacent pixels, respectively, in the horizontal scanning direction based on the line video signal supplied from the memory control unit 2311. That is, regarding the processing in the horizontal direction, when the nth pixel (N is an arbitrary natural number) in a certain row is set as the present pixel in time series, the horizontal direction voltage difference calculation unit 2312 calculates the difference (voltage difference) between the drive voltage supplied to the nth pixel (present pixel) in the same row and the drive voltage supplied to the adjacent N-1 th pixel. Similarly, the horizontal direction voltage difference calculation section 2312 calculates a difference (voltage difference) between the drive voltage supplied to the nth pixel (the present pixel) in the same row and the drive voltage supplied to the (N + 1) th pixel adjacent thereto. The voltage differences between the pixel itself and the pixels of the N-1 th pixel and the N +1 th pixel calculated by the horizontal voltage difference calculation unit 2312 are supplied to the correction amount calculation unit 232 of fig. 6 together with the line video signal.

The vertical direction voltage difference calculation section 2313 performs a process of detecting a voltage difference between the present pixel and an adjacent pixel in the vertical scanning direction based on the line video signal supplied from the memory control section 2311. That is, regarding the processing in the vertical direction, when the M-th row (M is an arbitrary natural number) of pixels is set as the pixel in the present row in time series, the vertical direction voltage difference calculation section 2313 calculates the difference (voltage difference) between the drive voltage supplied to the M-th row of pixels (the present pixel) and the drive voltage supplied to the adjacent pixel in the M-1 th row. Similarly, the vertical direction voltage difference calculation section 2313 calculates a difference (voltage difference) between the drive voltage supplied to the pixel in the mth row (the present pixel) and the drive voltage supplied to the adjacent pixel in the M +1 th row. The voltage difference between the pixel (the pixel) in the current row (M rows) and the adjacent pixels in the M-1 th and M +1 th rows calculated by the vertical voltage difference calculation unit 2313 is supplied to the correction amount calculation unit 232 in fig. 6.

In a display device for color display, when one pixel (main pixel) which is a unit for forming a color image is formed of, for example, sub-pixels (sub-pixels) of three primary colors of RGB, the above-described calculation of the voltage difference in the horizontal direction and the vertical direction is performed for each of the sub-pixels of RGB. That is, the inter-pixel voltage difference calculation unit 231 calculates, for each of the RGB sub-pixels, difference information between the nth pixel (own pixel) and two systems of the N-1 th pixel and the N +1 th pixel, and difference information between the own pixel in the M-th row and two systems of the respective adjacent pixels in the M-1 th row and the M +1 th row.

[ correction amount calculation part ]

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. 8. Fig. 8 is a block diagram showing an example of the configuration of the correction amount calculation unit 232. The correction amount calculation unit 232 is configured by 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 defect to be processed in the digital signal processing unit 23 of the present embodiment has a property that the direction of occurrence of the image quality defect on the liquid crystal panel 10 does not change during inversion/non-inversion of the video signal (inversion/non-inversion of the scanning direction). That is, the direction in which the image quality defect occurs is fixed between the pixels where the voltage difference occurs. Therefore, regardless of the horizontal/vertical scanning direction, a process of performing correction in the same direction is required.

For example, in a right vapor deposition liquid crystal display device, when a pixel on the left side of a pixel at a black level has an image quality defect, if a voltage difference is present between the pixel at the black level before the inversion of the video signal and the pixel on the left side, the image quality defect occurs in the pixel on the left side. As an example, if it is a projection type liquid crystal display system (projector system) using a liquid crystal panel as a light modulation unit (light valve), inversion/non-inversion is caused by a projection method or the like. Accordingly, in order to accurately display an output image, it is necessary to set inversion/non-inversion (scanning direction).

The correction amount calculation unit 232 includes a horizontal direction selection unit 2321 and a vertical direction selection unit 2322 to select voltage difference information to be used from the plurality of voltage difference information calculated by the horizontal direction voltage difference calculation unit 2312 and the vertical direction voltage difference calculation unit 2313 in fig. 7. The correction amount calculation unit 232 further includes a correction amount calculation unit 2323 and a correction amount interpolation unit 2324.

The horizontal direction selector 2321 acquires the voltage difference information between the present pixel and the adjacent pixel in the horizontal scanning direction and the horizontal scanning line signal supplied from the controller 26 of fig. 1 from the horizontal direction voltage difference calculator 2312. The voltage difference information between the present pixel and the adjacent pixel in the horizontal scanning direction refers to a difference between the driving voltage supplied to the nth pixel (present pixel) in the same row and the driving voltage supplied to the adjacent N-1 th pixel, and a difference between the driving voltage supplied to the nth pixel (present pixel) in the same row and the driving voltage supplied to the adjacent N +1 th pixel.

The horizontal scanning line signal includes information in the horizontal scanning direction with respect to the pixel array section 11 (see fig. 2A) in which the pixels 2 are two-dimensionally arranged in a matrix, that is, information indicating whether the horizontal scanning direction is from left to right or, conversely, from right to left. Alternatively, the horizontal scanning direction information may be obtained by analyzing the horizontal scanning line signal itself. Then, the horizontal direction selecting unit 2321 selects a pixel (correction target pixel) for which the 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 calculating unit 2323.

The vertical direction selector 2322 acquires the voltage difference information between the present pixel and the adjacent pixel in the vertical scanning direction and the vertical scanning line signal supplied from the controller 26 from the vertical direction voltage difference calculator 2313. The voltage difference information between the present pixel and the adjacent pixel in the vertical scanning direction refers to a difference between the drive voltage supplied to the pixel in the M-th row (the present pixel) and the drive voltage supplied to the adjacent pixel in the M-1 th row, and a difference between the drive voltage supplied to the pixel in the M-th row (the present pixel) and the drive voltage supplied to the adjacent pixel in the M +1 th row.

The vertical scanning line signal includes information with respect to the vertical scanning direction of the pixel array section 11, that is, information indicating whether the vertical scanning direction is from top to bottom or, conversely, from bottom to top. Alternatively, the vertical scanning direction information may be obtained by analyzing the vertical scanning line signal itself. Then, the vertical direction selection unit 2322 selects a pixel (correction target pixel) for which the 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.

Here, the voltage difference signal (voltage difference information) input from the inter-pixel voltage difference calculation unit 231 is described by taking the horizontal voltage difference as an example. Fig. 9 is a diagram showing drive voltage levels of a display image 140 with respect to an input video signal and an image 140A of a center line thereof. Fig. 10A shows a display image 141 after the occurrence of the image quality defect, fig. 10B shows a voltage difference signal obtained from a voltage difference between the pixel and the (N + 1) th pixel, and fig. 10C shows a voltage difference signal obtained from a voltage difference between the pixel and the (N-1) th pixel.

In fig. 9, an image 140A of the center line of the display image 140 is composed of eight pixels. Of the eight pixels, four pixels at the center are at black level, and four pixels at the periphery are at gray level. The gray-level pixel 141a is adjacent to the leftmost pixel 141b of the four black-level pixels, and the gray-level pixel 141d is adjacent to the rightmost pixel 141c of the four black-level pixels.

In fig. 10A showing the display image 141 after the occurrence of the image quality defect, the image 141A at the center line of the display image 141 is displayed with white bleeding in the pixel 141A adjacent to the leftmost pixel 141b of the black level of four pixels. In this case, the voltage difference signals shown in fig. 10B and 10C are output from the horizontal voltage difference calculation unit 2312 based on the input video signal.

Fig. 10B shows a voltage difference signal obtained from a voltage difference between the present pixel and the (N + 1) th pixel, that is, a voltage level difference obtained by subtracting the driving voltage level of the present pixel from the driving voltage level of the pixel adjacent to the right side of the present pixel. In fig. 10B, a voltage difference (difference between black potential-gray potential) between the pixel 141a and the pixel 141B is positive polarity, and a voltage difference (difference between gray potential-black potential) between the pixel 141c and the pixel 141d is negative polarity.

Fig. 10C shows a voltage difference signal obtained from a voltage difference between the present pixel and the N-1 th pixel, that is, a voltage level difference obtained by subtracting the driving voltage level of the pixel adjacent to the right side of the present pixel from the driving voltage level of the present pixel. In fig. 10C, a voltage difference between the pixel 141a and the pixel 141b (difference between gray potential and black potential) is a negative polarity, and a voltage difference between the pixel 141C and the pixel 141d (difference between black potential and gray potential) is a positive polarity. The candidate for the position to be corrected can be detected from the waveform of the voltage level difference.

Thus, the waveforms of the signals are completely different in the voltage difference signal derived from the voltage difference between the present pixel and the (N + 1) th pixel and the voltage difference signal derived from the voltage difference between the present pixel and the (N-1) th pixel, depending on the scanning direction. The same applies to the vertical scanning direction. At this time, for example, when a voltage difference occurs between two adjacent pixels, the horizontal direction selector 2321 and the vertical direction selector 2322 can select in time series whether the pixel in front is the pixel to be corrected or the pixel behind is the pixel to be corrected. The selection signal may be user definable and specifiable. Alternatively, since the pixel of the liquid crystal display device is changed due to a difference in the structure of the liquid crystal display device such as TN mode and VA mode, or due to a change in the vapor deposition direction (pre-tilt direction), the horizontal direction selecting unit 2321 and the vertical direction selecting unit 2322 may acquire information indicating the structure of the liquid crystal display device, vapor deposition direction information, or the like and reflect the information in the selection signal.

The correction amount calculation unit 2323 receives 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 line video signal supplied from the horizontal direction voltage difference calculation unit 2312 of fig. 7. The correction amount calculation unit 2323 calculates the amount of correction of the drive voltage 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 information on any one of a voltage difference between the own pixel and the N-1 th pixel and a voltage difference between the own pixel and the N +1 th pixel in the same row in accordance with the horizontal scanning line signal. Similarly, the vertical direction selection information supplied from the vertical direction selection unit 2322 includes any one of the voltage difference between the pixel of the M-th row and the pixel adjacent to the M-1-th row and the voltage difference between the pixel of the M-th row and the pixel adjacent to the M + 1-th row based on the vertical scanning line signal. The line video signal supplied from the horizontal direction voltage difference calculation unit 2312 includes drive voltage information for each pixel, which is represented by the present pixel and the correction target pixel.

The correction amount calculation unit 2323 calculates the correction amount of the drive voltage for the correction target pixel using the horizontal direction selection information, the vertical direction selection information, and the information of the drive voltage for the correction target pixel included in the line video signal as parameters. The correction amount calculation unit 2323 includes a two-dimensional or three-dimensional look-up table (hereinafter referred to as "LUT") 2325 that is referred to when calculating the correction amount of the drive voltage based on the horizontal direction selection information, the vertical direction selection information, and the information of the drive voltage.

The LUT2325 stores correction setting information for setting a correction amount to be applied to a pixel to be corrected in accordance with a difference between the voltage level of an input video signal of the pixel and a set voltage level of a pixel adjacent to the pixel, that is, a voltage level between the pixel and the adjacent pixel. The correction amount is set so that the average luminance of the correction target pixel after the drive voltage to the correction target pixel is corrected becomes the same luminance as that in the case where the drive voltage based on the input video signal before correction is supplied to the correction target pixel. Thus, 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 for calculating the correction amount of the drive voltage will be described. Fig. 11 shows an example of correction setting information to be referred to in calculation of the correction amount. Fig. 11 shows the relationship of the correction amount of the drive voltage, the drive voltage of the present pixel, and the voltage difference with the adjacent pixel. The blank column in fig. 11 is uncorrected. The numerical values shown in fig. 11 are examples, and are not limited to these numerical values. Here, when the driving voltage of the pixel is 0V and the driving voltage of the adjacent pixel is 3.975V, the voltage difference between the pixel and the adjacent pixel is 3.975V, so in the correction setting information shown in fig. 11, 1.2V shown by the grid is the correction amount of the pixel (correction target pixel), and the driving voltage of the pixel is corrected from 0V to 1.2V.

The LUT2325 discretely sets a correction target point determined by the relationship between the voltage level of the input video signal of the pixel and the voltage level difference between the pixel and the two pixels adjacent to the pixel. In addition, when the difference between the voltage levels of the present pixel and the adjacent pixel is small, the lateral electric field generated is weak and the occurrence of image quality defects is small. Therefore, a threshold value is set for the difference between the voltage levels of the pixel and the adjacent pixels, and if the difference exceeds the threshold value, the drive voltage of the pixel to be corrected is corrected. This makes it possible to effectively perform correction only for pixels having a high effect of improving image quality defects when correction is performed, without performing correction for all the pixels 2 of the liquid crystal panel 10. In addition, the correction amount may be defined and designated by the user.

Further, the LUT2325 has a plurality of tables based on the environmental information of the liquid crystal panel 10 supplied from the control unit 26 in fig. 1. Examples of the environmental information of the liquid crystal panel 10 include a horizontal/vertical scanning direction, a pretilt direction, and a distance (gap) between two adjacent pixels. Therefore, a table referred to in the relationship between the present pixel and the adjacent pixel on the left (right) side in the case where the horizontal scanning direction is from the left (right) to the right (left) and a table referred to in the relationship between the present pixel and the adjacent pixel on the upper (lower) side in the case where the vertical scanning direction is from the upper (lower) lower (upper) side are prepared.

Further, a table referred to in the case where the pretilt direction is toward the left (right) with respect to the front surface of the liquid crystal panel 10 is prepared. Further, since the intensity of the lateral electric field generated according to the distance (gap) between the adjacent two pixels is changed, the set value of the correction amount for the drive voltage of the correction target pixel is changed in consideration of the gap between the two pixels even if the drive voltages applied to the adjacent two pixels are the same or the voltage difference between the two pixels is the same. Thereby, the content and the correction amount are set in the LUT2325 so as to be able to correspond to various environmental information or a combination thereof.

The correction amount interpolation unit 2324 outputs the correction amount calculated by the correction amount calculation unit 2323 with reference to the LUT2325 as an interpolation. For example, since the correction target points are discretely set in the LUT2325, there may be no correction target point directly corresponding to the voltage level of the input video signal of the pixel itself. 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 directly corresponding to the voltage level difference between the two pixels of the present pixel and the adjacent pixel, the correction amount interpolation unit 2324 selects, for example, two correction target points closest to the voltage level difference between the two pixels. The correction amount interpolation unit 2324 performs interpolation processing such as linear interpolation on the correction amounts at these four correction target points, and outputs the processing result to the correction amount adjustment unit 233 of fig. 6.

[ correction amount adjustment part ]

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

As described above, the correction amount calculation unit 232 calculates the correction amount of the drive voltage supplied to the correction target pixel, based on the voltage difference between adjacent pixels and the video signal data (drive voltage information) for the correction target pixel, and with reference to the correction setting information. 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 for correcting the drive voltage to the target pixel to a fixed value, assuming a state of the liquid crystal panel 10 that changes with time to some extent. In the correction process using the fixed value of the correction amount X as it is, the liquid crystal panel 10 in the initial state that does not change with time may be over-corrected, and conversely, the liquid crystal panel 10 that changes with time further than the previously assumed state may be under-corrected. In either case, the image quality of the output image is degraded. Further, the image quality of the output image deteriorates as the temporal change (temporal degradation) of the liquid crystal panel 10 progresses.

Therefore, in the present embodiment, the correction amount arithmetic unit 232 is provided with a correction amount adjustment unit 233 at a stage subsequent to the correction amount arithmetic unit 232, and the correction amount adjustment unit 233 adjusts the correction amount X calculated by the correction amount arithmetic unit 232 in accordance with the image quality of the output image. The correction amount adjustment unit 233 adjusts the correction amount X for correcting the drive voltage of the pixel to be corrected in accordance with the image quality of the output image, and reflects the state of the image quality of the output image corresponding to the degree of temporal change in the correction amount X of the drive voltage of the pixel to be corrected. This makes it possible to correct the drive voltage of the correction target pixel without being affected by the temporal change of the liquid crystal panel 10, and thus, it is possible to improve the image quality of the output image.

In order to correct the correction amount X of the drive voltage of the pixel to be adjusted, the correction amount adjustment unit 233 needs to detect (grasp) the state of the image quality of the output image. As a method of detecting the state of the image quality of the output image, various methods listed below can be exemplified.

First detection method

The quality of the output image changes with time due to the intrusion of moisture or the like. Therefore, by measuring the use time of the liquid crystal panel 10, the degree of temporal change in the image quality of the output image (the state of the image quality) can be indirectly detected from the measured time. That is, the first detection method is as follows: the use time of the liquid crystal panel 10 is measured by a counter, and the state of the image quality of the output image is detected using the result of the counter (count value) as a parameter.

Second detection method

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

Third detection method

The third detection method is as follows: an output image is captured by an imaging unit (imaging device), and the degree of temporal change in the image quality (the state of the image quality) of the output image is directly detected from the result of the imaging. 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 image pickup section 52 is disposed in the vicinity of a projection lens 114 (see fig. 21) described later of the projector 51. Further, by capturing the output image 54 projected onto the screen 53 by the image capturing unit 52, the state of the image quality of the output image 54 can be directly detected from the captured result.

The method of detecting the state of the image quality of the output image is not limited to the first detection method, the second detection method, or the third detection method. For example, since the degree of moisture absorption of the liquid crystal panel 10 can be detected by chromaticity, it is also possible to measure the chromaticity of the liquid crystal panel 10 using a color colorimeter and use the measurement result as one of the parameters, or to measure the luminance of the liquid crystal panel 10 using a luminance colorimeter 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 by measuring chromaticity will be described. When the display of the white stripe and the black stripe is repeated in a pixel row unit (or a pixel column unit), that is, when the potential difference between two adjacent pixels is the maximum, the inter-pixel leakage is likely to occur. Therefore, in the 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 the luminance when white stripes and black stripes are alternately displayed is measured as illuminance C. Then, a moisture absorption index (moisture absorption degree) can be obtained from the illuminance C/(the average value of the illuminance a and the illuminance B), and this moisture absorption index can be used as one of the parameters for detecting the state of the image quality of the output image.

Hereinafter, specific examples of the correction amount adjusting section 233 when adjusting the correction amount based on the acquisition result of the output image acquired by using the third detection method will be described as examples 1 and 2. Further, a specific example of the correction amount adjusting section 233 when adjusting the correction amount based on the use time acquired by using the first detection method will be described as example 2.

(example 1)

Example 1 is the following example: the correction amount adjustment unit 233 detects the state of the image quality of the output image based on the imaging result of the adjustment image (output image), and applies the third detection method described above to the correction amount X, that is, to the detection of the state of the image quality of the output image, reflecting the image quality information. In example 1, the moisture absorption index is used as a parameter for determining whether or not the drive voltage of the pixel to be corrected needs to be corrected. The same applies to the following examples. Fig. 13 shows a flow of processing for correction amount adjustment in the correction amount adjustment section 233 of embodiment 1.

A series of processing for correction amount adjustment described below is executed by software under the control of a processor such as an MPU constituting the digital signal processing unit 23 of fig. 6, for example. However, the present invention is not limited to the configuration executed by software, and each functional unit that executes the processing for adjusting the correction amount may be configured as hardware. The same applies to the later-described embodiments.

In the flowchart of fig. 13, the processor supplies the video signal of the adjustment image for correction amount adjustment to the projector 51 of fig. 12 and outputs the adjustment image (step S11), and then acquires image data obtained by capturing an output image, which is the adjustment image projected onto the screen 53, by using the imaging unit 52 (step S12). Next, the processor digitizes the image quality data of the adjustment image (output image) based on the acquired image data (step S13), and then sets a correction coefficient α corresponding to the state of the image quality of the output image based on the digitized image quality data (step S14).

The state of the image quality of the output image deteriorates (deteriorates) as the temporal change of the liquid crystal panel 10 progresses. Fig. 14 shows an example of the relationship between the use time of the liquid crystal panel 10, the state of the image quality of the output image, and the correction coefficient α. As shown in fig. 14, the quality of the output image deteriorates in accordance with the use time of the liquid crystal panel 10 to the extent of … … after 1 year, 3 years, or the like in the initial state of the liquid crystal panel 10. Therefore, in step S14, a value corresponding to the state of the image quality of the output image is set as the correction coefficient α.

Next, the processor obtains corrected image quality data, which is image quality data reflecting the correction coefficient α set in step S14, by calculation (step S15), and then compares the image quality data with reference image quality data to determine whether or not the drive voltage of the pixel to be corrected needs to be corrected (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 an initial state) or a value in a predetermined image quality setting range with the initial value as a reference. For example, based on the change in the moisture absorption index (moisture absorption degree) as described above, as shown in fig. 15, an image quality setting range of ± 5% can be used as a threshold value for determining whether or not the correction is necessary for the drive voltage of the correction target pixel, with reference to the initial value (moisture absorption index being 50%).

In the determination process of whether correction is necessary or not in step S16, it is determined that correction is necessary when the image quality falls below the image quality setting range. When determining that correction is necessary (yes in S16), the processor causes the correction coefficient α set in step S14 to be reflected in the correction amount X of the drive voltage of the pixel to be corrected calculated by the correction amount calculation unit 232 (step S17), and thereafter, ends the series of processing for adjusting the correction amount.

Specifically, in step S17, an arithmetic process is performed (correction amount X based on the voltage difference between two pixels) × (correction coefficient α corresponding to the image quality of the output image). The calculation result is a correction amount α X by which the correction coefficient α corresponding to the image quality of the output image is reflected (fed back) on the correction amount X based on the voltage difference between the two pixels.

This correction coefficient α is fed back to the correction setting information shown in fig. 11. Fig. 16 shows an example of correction setting information after the correction coefficient α is fed back. Fig. 16 shows the relationship of the correction amount of the drive voltage, the drive voltage of the present pixel, and the voltage difference with the adjacent pixel. The blank column in fig. 16 is uncorrected. The numerical values shown in fig. 16 are examples, and are not limited to these numerical values.

When determining that correction is not necessary (no in S16), the processor does not need to reflect the correction coefficient α on the correction amount X based on the voltage difference between the two pixels, and therefore, does not perform an operation of multiplying the correction amount X by the correction coefficient α and uses the correction amount X as it is (step S18), and ends a series of processing for correction amount adjustment.

According to the correction amount adjustment in the correction amount adjustment unit 233 of embodiment 1, the image pickup unit 52 captures an output image, and the state of the image quality of the output image is grasped based on the captured result, whereby the state of the image quality of the output image accompanying the temporal change of the liquid crystal panel 10 can be detected. Further, by setting the correction coefficient α based on the state of the image quality of the output image and feeding back the correction amount X of the drive voltage of the correction target pixel, the drive voltage can be corrected without being affected by the temporal change of the liquid crystal panel 10, and therefore, the image quality of the output image can be improved.

(example 2)

Example 2 is a modification of example 1. In example 1, a correction coefficient α corresponding to the state of the image quality of the output image is set, and image quality data (corrected image quality data) on which the correction coefficient α is reflected is calculated and compared with reference image quality data, thereby determining whether correction is necessary. In contrast, in example 2, an adjustment image in which the correction coefficient α is reflected is output, and the corrected image quality data is digitized based on the image data acquired again and compared with the reference image quality data, thereby determining whether or not correction is necessary.

Fig. 17 shows a flow of processing for correction amount adjustment in the correction amount adjustment section 233 of embodiment 2. In the flowchart of fig. 17, the processor outputs an adjustment image for correction amount adjustment from the projector 51 (step S21), and then acquires image data obtained by capturing an output image on the screen 53 using the image capturing section 52 (step S22).

Next, the processor digitizes the image quality data of the output image based on the acquired image data (step S23), and then sets a correction coefficient α corresponding to the state of the image quality of the output image based on the digitized image quality data (step S24). The correction coefficient α is the same as in the case of embodiment 1.

Next, the processor corrects the adjustment image using the correction coefficient α, outputs the corrected adjustment image from the projector 51 (step S25), and then acquires image data on the corrected adjustment image obtained by capturing the output image on the screen 53 using the image capturing section 52 (step S26).

Next, the processor digitizes the image quality data of the corrected adjustment image based on the acquired image data (step S27), and then compares the digitized image quality data of the corrected adjustment image with reference image quality data to determine whether or not the drive voltage of the correction target pixel needs to be corrected (step S28). The reference image quality data is the same as in example 1.

When the processor determines that correction is necessary (yes in S28), the processor causes the correction coefficient α set in step S24 to be reflected in the correction amount X of the drive voltage of the pixel to be corrected (step S29), and thereafter, the processor ends the series of processing for adjusting the correction amount. When determining that correction is not necessary (no in S28), the processor does not need to reflect the correction coefficient α on the correction amount X based on the voltage difference between the two pixels, and therefore does not perform an operation of multiplying the correction amount X by the correction coefficient α and uses the correction amount X as it is (step S30), and ends the series of processing for correction amount adjustment.

The correction amount adjustment by the correction amount adjustment unit 233 according to embodiment 2 can provide the same operation and effect as those of embodiment 1. In embodiment 1, since the adjustment image in which the correction coefficient α is reflected is output and the corrected image quality data is digitized based on the image data acquired again to determine whether or not correction is necessary, it is possible to more reliably determine whether or not correction is necessary.

(example 3)

Example 3 is the following example: the correction amount adjustment unit 233 detects the state of the image quality of the output image based on the use time of the liquid crystal panel 10, and reflects the image quality information on the correction amount X, that is, applies the first detection method described above to the detection of the state of the image quality of the output image. In example 3, the following configuration is adopted: a plurality of correction setting tables corresponding to the use time of the liquid crystal panel 10 are prepared in advance as correction setting information in an LUT (look-up table), and the table is selected based on the image quality information. The LUTs of the plurality of correction setting tables are stored in, for example, a frame memory (not shown) built in the correction amount adjustment unit 233.

Fig. 18 is a diagram showing an example of the relationship between the usage time of the liquid crystal panel, the state of the image quality of the output image, and the correction setting table. Here, the following example is illustrated as the plurality of correction setting tables: two correction setting tables a corresponding to a period from an initial state of the liquid crystal panel 10 to a lapse of about 1 year in use time and two correction setting tables B corresponding to a period from a lapse of about 1 year in use time to a lapse of about 2 years in use time are used. However, the correction setting table is not limited to two, and may be three or more.

Fig. 19 shows an example of the numerical values of the correction setting table a and the correction setting table B. Each table in fig. 19 shows a relationship between the correction amount of the drive voltage, the drive voltage of the present pixel, and the voltage difference between the present pixel and the adjacent pixel. The blank column in fig. 19 is uncorrected. 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 section 233 of embodiment 3 will be described with reference to fig. 20. Fig. 20 is a flowchart showing a flow of processing for correction amount adjustment in the correction amount adjustment section 233 of embodiment 3.

In the flowchart of fig. 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 intrusion of moisture or the like, the degree of temporal change in the image quality of the output image (the state of the image quality) can be indirectly detected from the count value (measurement time) by counting the use time of the liquid crystal panel 10. That is, by acquiring the count value of the use time of the liquid crystal panel 10, the degree of temporal change in the image quality of the output image can be grasped.

Next, the processor selects one of the plurality of correction setting tables, i.e., the correction setting table a or the correction setting table B, from the LUT based on the acquired count value of the use time (step S32). As an example, if the use time of the liquid crystal panel 10 is in the initial state, the correction amount X calculated by the correction amount calculation unit 232 is directly used as the correction amount of the drive voltage of the correction target pixel. The correction setting table A is selected if the period from the initial state to the use time is about 1 year, and the correction setting table B is selected if the use time is about 1 year to about 2 years.

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 B to calculate corrected image quality data (step S33), and then compares the corrected image quality data with reference image quality data to determine whether or not the drive voltage of the correction target pixel needs to be corrected (step S34). Here, the image quality data to be compared with the corrected image quality data is the same as that in the case of example 1.

When the processor determines that correction is necessary (yes in S34), the processor causes the correction setting table a or B selected in step S32 to be reflected in the correction amount X of the drive voltage of the correction target pixel as the correction amount of the drive voltage of the correction target pixel (step S35), and thereafter, the processor ends the series of processing for adjusting the correction amount.

When determining that correction is not necessary (no in S34), the processor does not need to reflect the correction setting table a/B on the correction amount X based on the voltage difference between the two pixels, and therefore, directly uses the correction amount X calculated by the correction amount calculation unit 232 (step S36), and ends the series of processing for correction amount adjustment.

According to the correction amount adjustment in the correction amount adjustment unit 233 of embodiment 3, the use time of the liquid crystal panel 10 is counted, and the state of the image quality of the output image is grasped based on the count result, whereby the state of the image quality of the output image accompanying the temporal change of the liquid crystal panel 10 can be detected. Further, by selecting one of a plurality of correction setting tables prepared in advance based on the state of the image quality of the output image and reflecting the correction amount X of the drive voltage of the correction target pixel, the drive voltage can be corrected without being affected by the temporal change of the liquid crystal panel 10, and therefore, the image quality of the output image can be improved.

In embodiment 3, the first detection method using the use time of the liquid crystal panel 10 is applied to the detection of the state of the image quality of the output image, but the second detection method may be used in combination. That is, the temperature and humidity in the use environment of the liquid crystal panel 10 are measured, and the state of the image quality of the output image can be detected in addition to the use time of the liquid crystal panel 10 using the individual temperature, the individual humidity, or both the temperature and the humidity as one of the parameters. By using the first detection method and the second detection method in combination, the detection accuracy of the image quality of the output image can be further improved.

< modification example >

The technology of the present disclosure has been described above based on preferred embodiments, but the technology of the present disclosure is not limited to the embodiments. The configuration and structure of the display device described in the above embodiments are examples, and can be changed as appropriate. For example, although the technique of the present disclosure has been described using a liquid crystal display device (liquid crystal panel) as an example in the above embodiment, the occurrence of the image quality defect due to the lateral electric field is not limited to the liquid crystal display device.

That is, the image quality defect caused by the lateral electric field is a phenomenon that occurs in a display device in which pixels are two-dimensionally arranged in a matrix and a display drive method is performed by applying a voltage to a scanning line and a signal line. For example, in an organic EL (ElectroLuminescence) display device, a transverse electric field causes disturbance in movement of electrons and holes in an organic EL element, and thus image quality is poor. In addition, in the plasma display device, the generation of plasma in the pixel is affected by the lateral electric field, and image quality is deteriorated. Therefore, the technique of the present disclosure can be applied to the display devices of all the above-described modes.

The display device of the present disclosure described above can be used as a display unit (display device) of an electronic device in all fields in which a video signal input to the electronic device or a video signal generated in the electronic device is displayed as an image or a video. Examples of the electronic device include a projection type liquid crystal display device, a television, a notebook type personal computer, a digital still camera, a mobile terminal device such as a mobile phone, and the like. However, it is not limited thereto.

The display device of the present disclosure further includes a module-shaped display device of a sealed configuration. The display module may be provided with a circuit portion for inputting and outputting signals to and from the pixel array portion from the outside, a Flexible Printed Circuit (FPC), or the like. Hereinafter, a projection type liquid crystal display device is exemplified as a specific example of an electronic apparatus using the display device of the present disclosure. However, the specific example illustrated here is merely an example, and is not limited to the projection type liquid crystal display device.

[ projection type liquid Crystal display device ]

A projection type liquid crystal display device (so-called projector) generally employs the following three-panel system: color display is performed by additive color mixing, and images of the primary colors, namely red (R), green (G), and blue (B), are produced by three liquid crystal panels using liquid crystal panels, respectively, and then the images are synthesized by a prism. A liquid crystal panel used for a projection type liquid crystal display device is generally a panel having a size of about 1.0 inch. Fig. 21 shows an outline of an optical system of a three-plate projection type liquid crystal display device (projector) as 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 a polarization conversion element 102, and then is uniformized by a fly-eye lens 103 and incident on a dichroic mirror 104. Then, only a specific color component, for example, a light component of R (red) passes through the dichroic mirror 104, and the light component of the remaining color is reflected by the dichroic mirror 104. The light component of R transmitted through the dichroic mirror 104 changes its optical path by the mirror 105, and then enters the liquid crystal panel 107R of R through the lens 106R.

As for the light component reflected by the dichroic mirror 104, for example, a light component of G (green) is reflected by the dichroic mirror 108 and a light component of B (blue) is transmitted through the dichroic mirror 108. The light component of G reflected by the dichroic mirror 108 is incident on the liquid crystal panel 107G of G through the lens 106G. The light component of B transmitted through the dichroic mirror 108 passes through the lens 109, is changed in optical path by the mirror 110, further passes through the lens 111, is changed in optical path by the mirror 112, and is incident on the liquid crystal panel 107B of B through the lens 106B.

Although not shown in fig. 21, polarizers are disposed 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 arranging a pair of polarizing plates on the incident side and the emission side so that the directions of polarization are perpendicular to each other (cross nicol), and a normally black mode can be set by arranging the polarizing plates so that the directions of polarization are parallel to each other (parallel nicol).

The light components passing through R, G, B of the

liquid crystal panels

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

In the three-panel 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 serving as the light modulation means (light valve). The display device according to the above-described embodiment can correct the drive voltage of the correction target pixel without being affected by temporal changes, and therefore can improve the image quality of the output image. Therefore, by using the display device of the above-described embodiment as the light modulation means of the projection type liquid crystal display device, it is possible to contribute to improvement of the display quality of the projection type liquid crystal display device.

< constitution that can be adopted in the present disclosure >

The present disclosure can also adopt the following configurations.

Display apparatus

[ A-1] A display device comprising:

a correction amount calculation unit that calculates a correction amount for correcting the driving voltage of a pixel to be corrected, the pixel to be corrected having luminance change due to the difference in the driving voltage detected by the difference detection unit;

[ A-2] the display device according to the above [ A-1], wherein,

the correction amount adjustment unit captures an adjustment image for correction amount adjustment, and uses captured image data thereof as a parameter for detecting a state of image quality of an output image.

[ A-3] the display device according to the above [ A-2], wherein,

the correction amount adjustment unit digitizes image quality data based on captured image data obtained by capturing an adjustment image, sets a correction coefficient based on the image quality data, calculates corrected image quality data in which the correction coefficient is reflected, and determines whether or not the drive voltage of the pixel to be corrected needs to be corrected based on the corrected image quality data obtained by the calculation.

[ A-4] the display device according to the above [ A-3], wherein,

the correction amount adjustment unit compares the corrected image quality data obtained by the calculation with the reference image quality data to determine whether or not correction is necessary.

[ A-5] the display device according to the above [ A-2], wherein,

the correction amount adjustment unit digitizes image quality data based on captured image data obtained by capturing an adjustment image, sets a correction coefficient based on the image quality data, corrects the adjustment image using the correction coefficient, and outputs the corrected adjustment image.

[ A-6] the display device according to the above [ A-5], wherein,

the correction amount adjustment unit compares the digitized corrected image quality data with reference image quality data to determine whether correction is necessary.

[ A-7] the display device according to the above [ A-1], wherein,

the correction amount adjustment unit counts the use 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.

[ A-8] the display device according to the above [ A-7], wherein,

the correction amount adjustment unit has a plurality of correction setting tables corresponding to the use time of the display panel.

[ A-9] the display device according to the above [ A-8], wherein,

the correction amount adjustment section selects one of the plurality of correction setting tables based on a count value of a use time of the display panel.

[ A-10] the display device according to the above [ A-9], wherein,

the correction amount adjustment unit calculates the corrected image quality data in which the selected correction setting table is reflected, and determines whether or not the drive voltage of the pixel to be corrected needs to be corrected based on the corrected image quality data obtained by the calculation.

[ A-11] the display device according to the above [ A-10], wherein,

[ A-12] the display device according to any one of [ A-7] to [ A-11] above, wherein,

the correction amount adjustment section uses temperature, humidity, or both temperature and humidity in the usage environment of the display panel as one of the parameters.

[ A-13] the display device according to any one of [ A-7] to [ A-11] above, wherein,

the correction amount adjustment unit uses, as one of the parameters, chromaticity of the display panel measured by using a color colorimeter or luminance of the display panel measured by using a luminance meter.

Method for driving display device

[ B-1] A driving method of a display device, which executes the following processes:

[ B-2] the method for driving a display device according to the above [ B-1], wherein,

in the correction amount adjustment step, an adjustment image for correction amount adjustment is captured, and captured image data of the adjustment image is used as a parameter for detecting the state of the image quality of the output image.

[ B-3] the method for driving a display device according to the above [ B-2], wherein,

in the correction amount adjustment step, image quality data is digitized based on captured image data obtained by capturing an adjustment image, a correction coefficient is set based on the image quality data, the corrected image quality data in which the correction coefficient is reflected is calculated, and whether or not the drive voltage of the pixel to be corrected needs to be corrected is determined based on the corrected image quality data obtained by the calculation.

[ B-4] the method for driving a display device according to the above [ B-3], wherein,

in the correction amount adjustment step, it is determined whether or not correction is necessary by comparing the corrected image quality data obtained by the calculation with the reference image quality data.

[ B-5] the method for driving a display device according to the above [ B-2], wherein,

in the correction amount adjustment step, image quality data is digitized based on captured image data obtained by capturing an adjustment image, a correction coefficient is set based on the image quality data, the adjustment image is corrected using the correction coefficient and output, the image quality data is digitized based on the captured image data obtained by capturing the corrected adjustment image, and it is determined whether or not the drive voltage of the pixel to be corrected needs to be corrected based on the digitized image quality data of the corrected adjustment image.

[ B-6] the method for driving a display device according to the above [ B-5], wherein,

in the correction amount adjustment step, the digitized corrected image quality data is compared with the reference image quality data to determine whether correction is necessary.

[ B-7] the method for driving a display device according to the above [ B-1], wherein,

in the correction amount adjustment step, the use 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.

[ B-8] the method for driving a display device according to the above [ B-7], wherein,

in the correction amount adjusting step, a plurality of correction setting tables corresponding to the use time of the display panel are provided.

[ B-9] the method for driving a display device according to the above [ B-8], wherein,

in the correction amount adjusting step, the correction amount adjusting section selects one of the plurality of correction setting tables based on a count value of a use time of the display panel.

[ B-10] the method for driving a display device according to the above [ B-9], wherein,

in the correction amount adjustment step, the correction amount adjustment section calculates the corrected image quality data in which the selected correction setting table is reflected, and determines whether or not the drive voltage of the pixel to be corrected needs to be corrected based on the corrected image quality data obtained by the calculation.

[ B-11] the method for driving a display device according to the above [ B-10], wherein,

[ B-12] the method for driving a display device according to any one of [ B-7] to [ B-11], wherein,

in the correction amount adjustment step, temperature, humidity, or both of the temperature and humidity in the usage environment of the display panel are used as one of the parameters.

[ B-13] the method for driving a display device according to any one of [ B-7] to [ B-11], wherein,

in the correction amount adjustment step, chromaticity of the display panel measured using a colorimeter or luminance of the display panel measured using a luminance meter is used as one of the parameters.

Electronic apparatus

[ C-1] an electronic device having a display device, the display device comprising:

[ C-2] the electronic device according to [ C-1] above, wherein,

[ C-3] the electronic device according to [ C-2] above, wherein,

[ C-4] the electronic device according to [ C-3] above, wherein,

[ C-5] the electronic device according to [ C-2] above, wherein,

[ C-6] the electronic device according to [ C-5] above, wherein,

[ C-7] the electronic device according to [ C-1] above, wherein,

[ C-8] the electronic device according to [ C-7] above, wherein,

[ C-9] the electronic device according to [ C-8] above, wherein,

[ C-10] the electronic device according to [ C-9] above, wherein,

[ C-11] the electronic device according to [ C-10] above, wherein,

[ C-12] the electronic device according to any one of [ C-7] to [ C-11] above, wherein,

[ C-13] the electronic device according to any one of [ C-7] to [ C-11] above, wherein,

Description of reference numerals

1 … liquid crystal display device; 2 … pixels; 10 … liquid crystal panel; 20 … video signal processing circuit; 21 … A/D PLL unit; 22 … video signal conversion part; 23 … digital signal processing section; 24 … sample-and-hold section; 25 … image memory; 26 … control section; 231 … a voltage difference calculation unit between adjacent pixels; 232 … correction amount calculation unit; 233 … correction amount adjustment unit; 234 … and an addition unit for the correction amount.

Claims

1. A display device is provided with:

2. The display device according to claim 1,

3. The display device according to claim 2,

4. The display device according to claim 3,

5. The display device according to claim 2,

6. The display device according to claim 5,

7. The display device according to claim 1,

8. The display device according to claim 7,

9. The display device according to claim 8,

10. The display device according to claim 9,

11. The display device according to claim 10,

12. The display device according to claim 7,

13. The display device according to claim 7,

14. A driving method of a display device performs the following processes:

15. An electronic device having a display device, the display device comprising: