WO2016080255A1

WO2016080255A1 - Display device

Info

Publication number: WO2016080255A1
Application number: PCT/JP2015/081696
Authority: WO
Inventors: 洋介梶川; 安西　教生; 孝司上野
Original assignee: シャープ株式会社
Priority date: 2014-11-18
Filing date: 2015-11-11
Publication date: 2016-05-26

Abstract

This liquid crystal display device (10) is provided with: an array substrate (11b); a plurality of gate lines (19); a plurality of source lines (20); a plurality of transparent electrodes (18) respectively disposed in regions (31) formed by the plurality of gate lines (19) and the plurality of source lines (20) intersecting with each other; a plurality of TFTs (17) respectively disposed in the regions (31) and having gate electrodes (17a) connected to the gate lines (19), source electrodes (17b) connected to the source lines (20), and drain electrodes (17c) connected to the transparent electrodes (18); and an inspection line (32) connected to a drain electrode (17c) of at least one TFT (17) from among the plurality of TFTs (17) and also connectable to a DC component extracting unit (34) for extracting a DC component Vd (DC) of a drain voltage Vd applied to the drain electrode (17c).

Description

Display device

The present invention relates to a display device.

A liquid crystal panel used in a liquid crystal display device has a structure in which a liquid crystal layer is sandwiched between a pair of glass substrates. One of the glass substrates is an array substrate having TFTs and pixel electrodes as switching elements. Composed. This array substrate has a configuration in which gate wirings and source wirings are provided in a grid pattern on the substrate, and TFTs and pixel electrodes are provided at intersections of the gate wirings and the source wirings. In the liquid crystal display device having such a configuration, in order to suppress the occurrence of a phenomenon called burn-in, in which the liquid crystal molecules are oriented in a specific direction, the pixel electrode is interposed between the common electrode facing the pixel electrode. A technique for applying a voltage that reverses with a field period is known. When such a technique is employed, flicker called flicker may occur depending on the voltage applied between the pixel electrode and the common electrode.

Patent Document 1 below includes an optical unit that collects transmitted light from a liquid crystal display panel on a surface of an optical sensor by a condensing lens and detects the level of transmitted light by the optical sensor, and based on the detection signal. Thus, a technology related to a liquid crystal display panel automatic adjustment device that automatically adjusts a plurality of trimmers provided in a liquid crystal display panel and sets flicker to a good state is disclosed.

JP-A-6-130920

(Problems to be solved by the invention)
However, in the case of using the liquid crystal display panel automatic adjustment device disclosed in Patent Document 1 described above, it is necessary to detect the level of transmitted light using an optical unit, and a large-scale facility such as an optical sensor is required. In addition, as a technique that does not require large-scale equipment, for example, it is conceivable that the presence or absence of flicker is grasped by an inspector's visual observation, and the liquid crystal display device is adjusted by one's own hand when the inspector determines that it is necessary. However, with such a method, there is a possibility that a determination error for each inspector or a work error related to the adjustment work may occur.

The present invention has been completed based on the above circumstances, and an object thereof is to provide a display device capable of suppressing the occurrence of flicker.

(Means for solving the problem)
The display device of the present invention includes a substrate, a plurality of gate wirings arranged in parallel on the substrate, a plurality of source wirings arranged in parallel across the gate wiring on the substrate, and a plurality of the gate wirings And a plurality of transparent electrodes respectively disposed in a region formed by intersecting the plurality of source wirings, a gate electrode disposed in each of the regions and connected to the gate wiring, and connected to the source wiring A plurality of switching elements having a source electrode and a drain electrode connected to the transparent electrode, and connected to the drain electrode of at least one of the plurality of switching elements and applied to the drain electrode And a wiring for inspection that can be connected to a DC component extraction unit that extracts a DC component of the voltage to be detected.

Since the display device of the present invention includes the inspection wiring that can be connected to the direct current component extraction unit that extracts the direct current component of the voltage value of the drain electrode, the direct current component of the voltage value of the drain electrode can be obtained via the inspection wiring. Can be extracted. For this reason, based on the DC component information, for example, the potential difference between the transparent electrode and the common electrode can be adjusted to suppress flicker of the display device.

The following configuration is preferable as an embodiment of the present invention.
(1) The substrate is divided into a display region and a non-display region surrounding the display region, and the switching element to which the inspection wiring is connected includes a plurality of gate wirings in the non-display region of the substrate. The plurality of source lines are arranged in a dummy pixel region formed by intersecting. According to such a configuration, the inspection wiring is not routed to the pixel region, and the display quality of the display device is not impaired by providing the inspection wiring.

(2) The substrate is divided into a display region and a non-display region surrounding the display region, and the switching element to which the inspection wiring is connected includes a plurality of gate wirings and a plurality of gate wirings in the display region of the substrate. Are arranged in a pixel region formed by crossing the source wiring. According to such a configuration, even when it is difficult to secure a region formed by the intersection of the gate wiring and the source wiring in the non-display region due to the narrow frame of the display device, the pixel region The DC component of the drain electrode voltage value can be extracted.

(3) A common electrode that forms a capacitance with the transparent electrode is further provided. When the drain voltage applied to the drain electrode is an alternating voltage, the common electrode has a positive polarity. The direct current component extracted by the direct current component extraction unit so that the potential difference between the drain electrode and the common electrode and the potential difference between the drain electrode and the common electrode at the time of the negative polarity are substantially the same. A common voltage calculated based on the above is applied. According to such a configuration, by adjusting the common voltage, the potential difference between the common electrode is substantially the same between the positive polarity and the negative polarity of the drain voltage, and thus the occurrence of flicker is suitably suppressed. can do.

(4) a storage unit that stores a setting value of the common voltage; and a common voltage generation unit that generates the common voltage based on the setting value of the common voltage stored in the storage unit, The wiring for use has a terminal portion that can be connected to an inspection device including the DC component extraction unit, and the inspection device further includes a common voltage calculation unit that calculates a set value of the common voltage, The setting value of the common voltage calculated by the common voltage calculation unit of the inspection apparatus is written in the storage unit. According to such a configuration, by using the inspection apparatus, adjustment until the generation of the optimized common voltage is not required, for example, an optical unit for detecting flicker or the like, and the inspector visually checks the flicker. It is possible to automatically perform the operation without checking the presence or absence and adjusting the display device manually.

(5) The storage unit and the common voltage generation unit are provided on the substrate. According to such a configuration, by providing the storage unit and the common voltage generation unit on the substrate, it is possible to realize a display device in which flicker is preferably suppressed.

(6) A circuit board for supplying a voltage to the common electrode is further provided, and the storage unit and the common voltage generation unit are provided on the circuit board. According to such a configuration, the storage unit and the common voltage generation unit are provided on the circuit board even when it is difficult to provide the storage unit and the common voltage generation unit on the substrate due to the narrow frame of the display device. Thus, it is possible to realize a display device in which flicker is preferably suppressed.

(7) The apparatus further includes the DC component extraction unit and a common voltage generation unit that generates the common voltage based on the DC component extracted by the DC component extraction unit. According to such a configuration, the common voltage can be appropriately adjusted not only when the liquid crystal display device is manufactured but also when the liquid crystal display device is used. For example, flicker occurs due to a change in temperature environment or the like. Can be suppressed.

(8) Based on the DC component extraction unit, the DC component extracted by the DC component extraction unit, a common voltage calculation unit that calculates a set value of the common voltage, and the common voltage calculated by the common voltage calculation unit A common voltage generation unit configured to generate the common voltage based on a voltage setting value; According to such a configuration, even if it is difficult to generate the common voltage directly from the direct current component due to design constraints, the common voltage calculation unit calculates the common voltage setting value and based on this Common voltage can be generated.

(9) The DC component extraction unit, a common voltage calculation unit that calculates a set value of the common voltage based on the DC component extracted by the DC component extraction unit, and the common voltage calculated by the common voltage calculation unit A storage unit that stores a set value of the voltage; and a common voltage generation unit that generates the common voltage based on the set value of the common voltage stored in the storage unit. According to such a configuration, the load on the DC component extraction unit and the common voltage calculation unit can be reduced by generating the common voltage based on the set value stored in the storage unit for a certain period.

(10) A plurality of the inspection wirings are provided branched from the drain electrode. According to such a configuration, when one inspection wiring is disconnected at the time of manufacture, another inspection wiring can be used as a backup, so that it is not necessary to make the substrate unusable. Also, it can be expected to improve the yield.

(11) A DC component that is connected to the drain electrode of at least one switching element among the plurality of switching elements and is arranged in the same manner as the inspection wiring, and extracts a DC component of a voltage value of the drain electrode. A dummy wiring not connected to the extraction unit is further provided. According to such a configuration, the inspection wiring is arranged by arranging the dummy wiring in the area where the inspection wiring is not arranged in the area formed by the intersection of the gate wiring and the source wiring. It is possible to suppress a situation in which the electrical characteristics differ between the region where the inspection wiring is arranged and the region where the inspection wiring is not arranged.

(12) A counter substrate that is opposed to the substrate and on which a color filter is disposed, and a liquid crystal layer that is sandwiched between the substrate and the counter substrate. Such a display device can be applied as a liquid crystal display device to various uses, for example, a display such as a portable information terminal or a television receiver.

(The invention's effect)
ADVANTAGE OF THE INVENTION According to this invention, the display apparatus which can suppress generation | occurrence | production of flicker can be provided.

1 is a schematic plan view showing a connection configuration of a liquid crystal panel on which a driver according to Embodiment 1 of the present invention is mounted, a flexible board, and a control circuit board. Schematic cross-sectional view showing a cross-sectional configuration along the long side direction of the liquid crystal display device Circuit diagram showing circuit configuration of dummy pixel and display pixel in array substrate Block diagram showing configuration and inspection mode of liquid crystal display device The figure showing the change for every frame regarding the voltage of the data signal supplied to the drain electrode, the drain voltage, and the common voltage The circuit diagram which shows the circuit structure of the display pixel provided with the test | inspection wiring in the array substrate which concerns on Embodiment 2 of this invention, and another display pixel Block diagram showing configuration and inspection mode of liquid crystal display device The block diagram which shows the structure of the liquid crystal display device which concerns on Embodiment 3 of this invention, and its test | inspection aspect. The block diagram which shows the structure of the liquid crystal display device which concerns on Embodiment 4 of this invention. The block diagram which shows the structure of the liquid crystal display device which concerns on Embodiment 5 of this invention. The block diagram which shows the structure of the liquid crystal display device which concerns on Embodiment 6 of this invention. The circuit diagram which shows the circuit structure of the dummy pixel and display pixel in the array substrate which concerns on Embodiment 7 of this invention. The circuit diagram which shows the circuit structure of the dummy pixel and display pixel in the array substrate which concerns on Embodiment 8 of this invention.

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. In this embodiment, the liquid crystal display device 10 is illustrated as a display device. A part of each drawing shows an X-axis, a Y-axis, and a Z-axis, and the directions of the axes are drawn in common directions in the drawings. As for the vertical direction, FIG. 2 is used as a reference, and the upper side of the figure is the front side and the lower side of the figure is the back side.

As shown in FIGS. 1 and 2, the liquid crystal display device (display device) 10 drives a liquid crystal panel 11 having a display area AA capable of displaying an image and a non-display area NAA outside the display area AA, and the liquid crystal panel 11. The driver (panel drive unit) 21 to be connected, the control circuit board (circuit board) 12 for supplying various input signals to the driver 21 from the outside, and the liquid crystal panel 11 and the external control circuit board 12 are electrically connected. A flexible substrate (external connection component) 13 and a backlight device (illumination device) 14 that is an external light source that supplies light to the liquid crystal panel 11 are provided. The liquid crystal display device 10 also includes a pair of front and back

exterior members

15 and 16 for housing and holding the liquid crystal panel 11 and the backlight device 14 assembled to each other. In addition, an opening 15a for allowing an image displayed in the display area AA of the liquid crystal panel 11 to be visually recognized from the outside is formed. The liquid crystal display device 10 according to the present embodiment includes a notebook computer (including a tablet notebook computer), a mobile phone (including a smartphone), a portable information terminal (including an electronic book, a PDA, etc.), a digital photo frame, It is used for various electronic devices (not shown) such as portable game machines and electronic ink paper. For this reason, the screen size of the liquid crystal panel 11 constituting the liquid crystal display device 10 is set to about several inches to several tens of inches, and is generally classified into a small size and a small size.

First, the backlight device 14 will be briefly described. As shown in FIG. 2, the backlight device 14 includes a chassis 14a having a substantially box shape that opens toward the front side (the liquid crystal panel 11 side), and a light source (not shown) disposed in the chassis 14a (for example, a cold cathode tube, LED, organic EL, etc.) and an optical member (not shown) arranged to cover the opening of the chassis 14a. The optical member has a function of converting light emitted from the light source into a planar shape.

Subsequently, the liquid crystal panel 11 will be described. As shown in FIG. 1, the liquid crystal panel 11 has a vertically long rectangular shape (rectangular shape) as a whole, and is displayed at a position offset toward one end side (the upper side shown in FIG. 1) in the long side direction. A portion (active area) AA is arranged, and a driver 21 and a flexible substrate 13 are respectively attached at positions offset toward the other end side (the lower side shown in FIG. 1) in the long side direction. In the liquid crystal panel 11, an area outside the display area AA is a non-display area (non-active area) NAA in which no image is displayed. The non-display area NAA is a substantially frame-shaped area (CF described later) surrounding the display area AA. Frame portion in the substrate 11a) and a region (the portion exposed without overlapping with the CF substrate 11a in the array substrate 11b to be described later) secured on the other end side in the long side direction. The area secured on the other end side in the long side direction includes the mounting area for the driver 21 and the flexible substrate 13. The short side direction in the liquid crystal panel 11 coincides with the X-axis direction of each drawing, and the long side direction coincides with the Y-axis direction of each drawing. In FIG. 1, a frame-shaped one-dot chain line that is slightly smaller than the CF substrate 11a represents the outer shape of the display area AA, and an area outside the one-dot chain line is a non-display area NAA.

Subsequently, members connected to the liquid crystal panel 11 will be described. As shown in FIGS. 1 and 2, the control circuit board 12 is attached to the back surface of the chassis 14a (the outer surface opposite to the liquid crystal panel 11 side) of the backlight device 14 with screws or the like. The control circuit board 12 is mounted with electronic components for supplying various input signals to the driver 21 on a board made of paper phenol or glass epoxy resin, and wiring (conductive path) of a predetermined pattern (not shown) is provided. Routed formation. One end (one end side) of the flexible substrate 13 is electrically and mechanically connected to the control circuit board 12 via an ACF (Anisotropic Conductive Film) (not shown).

As shown in FIG. 2, the flexible substrate (FPC substrate) 13 includes a base material made of a synthetic resin material (for example, polyimide resin) having insulating properties and flexibility, and a large number of wirings are provided on the base material. It has a pattern (not shown), and one end in the length direction is connected to the control circuit board 12 arranged on the back side of the chassis 14a as described above, while the other end Since the portion (the other end side) is connected to the array substrate 11 b in the liquid crystal panel 11, the liquid crystal display device 10 is bent in a folded shape so that the cross-sectional shape is substantially U-shaped. At both ends of the flexible substrate 13 in the length direction, the wiring pattern is exposed to the outside to form terminal portions (not shown), and these terminal portions are respectively connected to the control circuit board 12 and the liquid crystal panel 11. Are electrically connected to each other. Thereby, an input signal supplied from the control circuit board 12 side can be transmitted to the liquid crystal panel 11 side.

As shown in FIG. 1, the driver 21 is composed of an LSI chip having a drive circuit therein, and operates based on a signal supplied from a control circuit board 12 that is a signal supply source. Specifically, an input signal supplied from the control circuit board 12 is processed to generate an output signal, and the output signal is output toward the display area AA of the liquid crystal panel 11. In the present embodiment, the driver 21 uses a memory (storage unit) 36 that stores a setting value of a common voltage Vcom applied to the common electrode 22 described later, and a setting value of the common voltage Vcom stored in the memory 36. And a common voltage generator 37 for generating the common voltage Vcom. The driver 21 has a horizontally long shape when viewed in a plan view (has a long shape along the short side of the liquid crystal panel 11) and is directly mounted on the non-display area NAA of the array substrate 11b of the liquid crystal panel 11. That is, COG (Chip On Glass) is mounted. The long side direction of the driver 21 coincides with the X-axis direction (the short side direction of the liquid crystal panel 11), and the short side direction coincides with the Y-axis direction (the long side direction of the liquid crystal panel 11).

The liquid crystal panel 11 will be described again. As shown in FIG. 2, the liquid crystal panel 11 includes a pair of

substrates

11a and 11b, and a liquid crystal layer including liquid crystal molecules that are interposed between the

substrates

11a and 11b and that are substances whose optical characteristics change with application of an electric field. Liquid crystal) 11c, and both

substrates

11a and 11b are bonded together with a sealant 11d while maintaining a gap corresponding to the thickness of the liquid crystal layer 11c. The liquid crystal panel 11 according to the present embodiment is an FFS (Fringe Field Switching) mode in which the operation mode is further improved from the IPS (In-Plane Field Switching) mode, and is an array substrate (see Claims) of the pair of

substrates

11a and 11b. A transparent electrode 18 and a common electrode (counter electrode, common electrode) 22 which will be described later are formed on the substrate 11b side, and the transparent electrode 18 and the common electrode 22 are arranged in different layers. is there. The front side (front side) of the pair of

substrates

11a and 11b is a CF substrate (counter substrate) 11a, and the back side (back side) is an array substrate 11b. Among these, the CF substrate 11a has a short side dimension substantially equal to that of the array substrate 11b as shown in FIGS. 1 and 2, but the long side dimension is smaller than that of the array substrate 11b. It is bonded to 11b with one end (upper side shown in FIG. 1) in the long side direction aligned. Therefore, the other end (the lower side shown in FIG. 1) of the array substrate 11b in the long side direction is in a state in which the CF substrate 11a does not overlap over a predetermined range and both the front and back plate surfaces are exposed to the outside. Here, a mounting area for the driver 21 and the flexible board 13 is secured.

Subsequently, the configuration of the array substrate 11b will be described sequentially. In the array substrate 11b, as shown in FIG. 3, a plurality of gate wirings 19 are arranged in parallel on the array substrate 11b, and a plurality of source wirings 20 are arranged in parallel across the gate wiring 19 on the array substrate 11b. A plurality of transparent electrodes 18 are arranged in a region 31 formed by intersecting a gate wiring (scanning signal line, row control line) 19 and a source wiring (data signal line, column control line) 20, respectively. ing. In the region 31, a plurality of TFTs 17 are arranged corresponding to the respective transparent electrodes 18. In other words, a large number of TFTs 17 and transparent electrodes 18 that are switching elements are provided in a matrix, and the gate lines 19 and source lines 20 that form a lattice surround the TFTs 17 and the transparent electrodes 18. It is arranged in this way. The gate wiring 19 is arranged so as to overlap with one end of the transparent electrode 18 in a plan view (viewed from a normal direction to the plate surface of the array substrate 11b). For this reason, a parasitic capacitance Cgd is formed between the gate wiring 19 and the transparent electrode 18 (see FIG. 3).

Here, among the areas 31 formed by the intersection of the gate lines (scanning signal lines, row control lines) 19 and the source lines (data signal lines, column control lines) 20, those arranged in the display area AA Are referred to as a pixel area 31A, and those arranged in the non-display area NAA are referred to as a dummy pixel area 31B and are distinguished from each other. The pixel region 31A and the dummy pixel region 31B are collectively referred to as a region 31 when collectively referred to. Further, among the transparent electrodes 18, the one disposed in the pixel region 31 A is referred to as a pixel electrode 18 A, and the one disposed in the dummy pixel region 31 B is referred to as a dummy pixel electrode 18 B and is distinguished from each other. When these pixel electrode 18A and dummy pixel electrode 18B are generically referred to, they are simply referred to as transparent electrodes 18.

Further, on the array substrate 20, as shown in FIG. 3, auxiliary capacity wiring (storage capacity wiring, Cs wiring) 25 that is parallel to the gate wiring 19 and overlaps the other end of the transparent electrode 18 in plan view. Is provided. The auxiliary capacitance line 25 is made of the same metal film as the gate line 19 and is alternately arranged with the gate line 19. A predetermined reference potential is applied to the auxiliary capacitance line 25, and a storage capacitance Ccs is formed between the auxiliary capacitance line 25 and the transparent electrode 18.

The TFT 17 is connected to the gate electrode 17a connected to the gate wiring 19, the channel portion 17d made of a semiconductor film and overlapping the gate electrode 17a, the source wiring 20, and a part of the channel portion 17d. And a drain electrode 17c connected to the transparent electrode 18 while being connected to the other part of the channel part 17d. And the channel part 17d bridge | crosses the source electrode 17b and the drain electrode 17c, and enables the movement of the electron between both

electrodes

17b and 17c.

The transparent electrode 18 is made of a transparent conductive film, and forms a vertically long substantially rectangular shape (substantially rectangular shape) as a whole in a region 31 surrounded by the plurality of gate wirings 19 and the plurality of source wirings 20. Yes. The transparent electrode 18 is formed in a substantially comb-like shape by providing a plurality of vertically long slits (not shown). The transparent electrode 18 is formed such that an interlayer insulating film is interposed between the transparent electrode 18 and the common electrode 22 described below.

The common electrode 22 is made of a transparent conductive film formed in a layer different from that of the transparent electrode 18, and is a so-called solid pattern that extends over substantially the entire display area AA of the array substrate 11b and the dummy pixel area 31B in the non-display area NAA. It is said. The common electrode 22 is opposed to the transparent electrode 18 via an interlayer insulating film, and a capacitance Clc is formed therebetween. When a potential difference is generated between the common electrode 22 and the transparent electrode 18, the liquid crystal layer 11c has a normal direction to the plate surface of the array substrate 11b in addition to the component along the plate surface of the array substrate 11b by the slits of the transparent electrode 18. Since a fringe electric field (diagonal electric field) containing the above component is applied, among the liquid crystal molecules contained in the liquid crystal layer 11c, those present on the transparent electrode 18 in addition to those present in the slit are appropriately aligned. Can be switched to. Therefore, in the display area AA of the liquid crystal panel 11, the aperture ratio is increased to obtain a sufficient amount of transmitted light, and high viewing angle performance can be obtained.

In the display area AA of the CF substrate 11a, a large number of colored portions such as R (red), G (green), and B (blue) are superimposed on each pixel electrode 18A on the array substrate 11b side in a plan view. Color filters 11h arranged in parallel in a matrix are provided. Between each colored portion constituting the color filter 11h, a substantially lattice-shaped light shielding layer (black matrix) 11i for preventing color mixture is formed. The light shielding layer 11i is arranged so as to overlap the above-described gate wiring 19 and source wiring 20 in a plan view. Note that in the liquid crystal panel 11, one pixel as a display unit is formed by a set of three colored portions of R (red), G (green), and B (blue) and three pixel electrodes 18A facing them. It is configured. In the present embodiment, for convenience of explanation, a unit constituted by a set of any one color portion and one pixel electrode 18A facing the colored portion is referred to as a display pixel 30A. Further, in the non-display area NAA in the CF substrate 11a, a colored portion of any one color is formed so as to face the dummy pixel electrode 18B, and the display pixel 30A has the same mode as the above-described display pixel 30A. A dummy pixel 30B that does not contribute is configured. Note that the colored portion does not necessarily have to be formed in the dummy pixel 30B as long as it does not affect the electrical characteristics of the dummy pixel 30B. In the following description, when the display pixels 30A and the dummy pixels 30B are generically referred to, they are simply referred to as pixels 30.

Next, a configuration related to the dummy pixel 30B will be described. As shown in FIG. 3, the dummy pixels 30B are arranged in the non-display area NAA of the array substrate 11b (more specifically, the area overlapping the liquid crystal layer 11c in the non-display area NAA). The dummy pixel 30B has an inspection wiring 32 connected to the drain electrode 17c. In the present embodiment, in the display pixel 30A arranged in the display area AA, the inspection wiring 32 is not connected to the drain electrode 17c. In other words, the dummy pixel 30B and the display pixel 30A differ only in the presence or absence of the inspection wiring 32, and other configurations such as the size, shape, and routing path of each electrode are the same design. By measuring the drain voltage Vd of 30B, the drain voltage Vd of the display pixel 30A can be estimated. The dummy pixel 30 B can be said to be a drain voltage confirmation pixel for confirming the drain voltage Vd of the liquid crystal display device 10 through the inspection wiring 32.

As shown in FIG. 3, the inspection wiring 32 is electrically connected to the drain electrode 17c directly or via a dummy pixel electrode 18B. The inspection wiring 32 is routed to a region of the array substrate 11b that does not overlap the CF substrate 11a, and a terminal portion 33 is formed at the end opposite to the side connected to the drain electrode 17c. . And the terminal part 33 is mutually connectable with the test | inspection apparatus 40 mentioned later. It should be noted that the structure of the inspection wiring 32 and the wiring path thereof can be set as appropriate, and preferably formed in a manner that does not easily affect the electrical characteristics of each electrode provided in the dummy pixel electrode 18B. And have been routed. An aspect of inspecting the liquid crystal panel 11 by connecting the inspection device 40 to the inspection wiring 32 will be described later.

Here, the driving method of the liquid crystal display device 10 will be described with reference to FIGS. The common electrode 22 is applied with the common voltage Vcom generated by the common voltage generator 37 based on the set value of the common voltage Vcom stored in the memory 36, and the transparent electrode 18 by the TFT 17 as will be described later. By controlling the potential applied to the electrode 18, a predetermined potential difference can be generated between the

electrodes

18 and 22. In the present embodiment, the common voltage Vcom is always a constant value. Further, the reference potential of the auxiliary capacitance line 25 is set to the same potential as the common voltage Vcom of the common electrode 22.

When the TFT 17 is turned on by a scanning signal supplied to the gate electrode 17a through the gate wiring 19 at a predetermined timing (an on voltage Von is applied to the gate electrode), the source electrode 17b is connected through the source wiring 20. The data signal supplied to is transmitted to the drain electrode 17c through the channel portion 17d. At this time, the potential of the drain electrode 17 c is substantially the same as the potential applied to the source wiring 20. While the on voltage Von is applied to the gate electrode 17a, the charge applied from the source line 20 is charged to the liquid crystal layer 11c (electrostatic capacitance Clc) and the storage capacitor Ccs. Even after the TFT 17 is turned off (off voltage Voff is applied to the gate electrode), the charge charged in the liquid crystal layer 11c is retained, but the parasitic capacitance formed between the gate wiring 19 and the drain electrode 17c. Due to the influence of Cgd, a phenomenon occurs in which the potential of the drain electrode 17c is drawn by ΔV when the off voltage Voff is applied (see FIG. 5). This ΔV can be expressed as the following formula (1). Here, the values of the electrostatic capacitance Clc, the storage capacitance Ccs, and the parasitic capacitance Cgd are different for each liquid crystal panel 11 due to variations in manufacturing the liquid crystal panel 11. Therefore, ΔV has a different value for each liquid crystal panel 11.
ΔV = (Von−Voff) × Cgd ÷ (Clc + Ccs + Cgd) (1)

As shown in FIG. 5, the TFT 17 is driven by so-called “frame inversion driving” in which the polarity is inverted every frame display period, and has a relatively higher potential (positive polarity) than the common voltage Vcom of the common electrode 22. And a potential relatively lower than the common voltage Vcom of the common electrode 22 (negative potential) are alternately supplied to the transparent electrode 18 via the TFT 17 every frame display period. ing. The frame rate is set to 60 fps, for example. According to such a driving method, the direction in which the voltage is applied between the common electrode 22 and the transparent electrode 18 is reversed, so that the direction of the liquid crystal molecules contained in the liquid crystal layer 11c is in a state in which the direction is directed to a specific direction. It is possible to avoid the phenomenon from occurring.

On the other hand, in the frame inversion driving method, when the effective value of the voltage applied to the liquid crystal layer 11c is different between the positive polarity and the negative polarity at the time of polarity inversion, the light transmittance (brightness) is different for each frame period. Therefore, flickering called flicker occurs. Therefore, in order to suppress flicker, the common voltage Vcom is adjusted in consideration of ΔV so that the potential difference between the transparent electrode 18 and the common electrode 22 is the same between the positive polarity and the negative polarity. There is a need.

In the present embodiment, the liquid crystal display device 10 is inspected by using the inspection device 40 and adjusted to suppress the flicker. Hereinafter, this aspect will be described. As shown in FIG. 4, the inspection apparatus 40 includes a direct current component extraction unit 34 that extracts a direct current component Vd (DC) of the drain voltage Vd applied to the drain electrode 17c, and a drain electrode 17c when the drain voltage Vd is positive. DC component extracted by the DC component extraction unit 34 so that the potential difference between the drain electrode 17c and the common electrode 22 at the time of negative polarity of the drain voltage Vd and the common electrode 22 is substantially the same. And a common voltage calculation unit 35 that calculates the common voltage Vcom based on. The inspection device 40 only needs to include at least the DC component extraction unit 34 and the common voltage calculation unit 35, and may further include various other functional units.

The DC component extraction unit 34 has a DC component measurement meter. When an electric signal of the drain voltage Vd (AC) taken into the inspection device 40 is input, the DC component extraction unit 34 converts this into DC component Vd (DC) information, that is, The average value information is converted and output. The common voltage calculation unit 35 has a function of converting the DC component Vd (DC) information into a set value of the common voltage Vcom. Based on the DC component Vd (DC) information obtained by the DC component extraction unit 34, the common voltage calculation unit 35 A set value of the common voltage Vcom is calculated by the set conversion formula and output. In the present embodiment, since the common voltage Vcom is a constant value for each frame, the common voltage Vcom is equivalent to the DC component Vd (DC). As another mode of the common voltage calculation unit 35, in the driving method of the liquid crystal display device in which the voltage applied to the common electrode 22 is shifted together with the polarity inversion of the drain voltage Vd, the voltage of the common electrode 22 for each frame is changed. The set value may be calculated, or in addition, the conversion formula may be appropriately determined in consideration of the driving method and the electrical characteristics of the display panel 11.

The liquid crystal display device 10 is shipped as a product after being manufactured and inspected and adjusted by the inspection device 40. Specifically, when the liquid crystal display device 10 is manufactured, the inspection device 40 is connected to the terminal portion 33 of the inspection wiring 32 and writes the common voltage Vcom set value to the memory 36 provided in the driver 21. Connected as possible. Then, in the liquid crystal display device 10 connected to a power source (not shown), the dummy pixel 30B is AC driven over a predetermined frame period, and the electrical signal of the drain voltage Vd (AC) of the drain electrode 17c is supplied to the inspection wiring 32. Directly into the inspection apparatus 40 via Then, in the inspection device 40, the set value of the optimized common voltage Vcom is written in the memory 36 through the direct current component extraction unit 34 and the common voltage calculation unit 35 sequentially. Then, when displaying on the liquid crystal display device 10, the common voltage Vcom is generated by the common voltage generator 37 based on the set value of the common voltage Vcom stored in the memory 36. At this time, since the display pixel 30A has the same electrical characteristics as the dummy pixel 30B, the potential difference between the pixel electrode 18A and the common electrode 22 is positive and negative as in the dummy pixel 30B. The liquid crystal display device 10 is in a state in which the occurrence of flicker is suppressed, that is, in a state in which flicker adjustment is performed. The series of operations up to this point can be automatically performed by the inspection apparatus 40 without any work such as a person checking and adjusting flicker.

As described above, the liquid crystal display device 10 according to the present embodiment includes the array substrate 11b, the plurality of gate wirings 19 arranged in parallel on the array substrate 11b, and the gate wirings 19 arranged in parallel on the array substrate 11b. And a plurality of transparent electrodes respectively disposed in a region 31 (a pixel region 31A and a dummy pixel region 31B) formed by intersecting a plurality of source wires 20, a plurality of gate wires 19 and a plurality of source wires 20. (Pixel electrode 18A and dummy pixel electrode 18B) and a drain connected to a gate electrode 17a connected to the gate wiring 19, a source electrode 17b connected to the source wiring 20, and a transparent electrode 18, respectively. A plurality of TFTs 17 having an electrode 17c and a T disposed in the dummy pixel region 31B among the plurality of TFTs 17. An inspection wiring 32 connected to the drain electrode 17c of T17 and connectable to a DC component extraction unit 34 for extracting the DC component Vd (DC) of the drain voltage Vd applied to the drain electrode 17c; Prepare.

The liquid crystal display device 10 includes the inspection wiring 32 that can be connected to the direct current component extraction unit 34 that extracts the direct current component Vd (DC) of the voltage value of the drain electrode 17c. The DC component Vd (DC) of the voltage value of the drain electrode 17c can be extracted. For this reason, based on the DC component Vd (DC) information, for example, the potential difference between the transparent electrode 18 and the common electrode 22 can be adjusted to suppress flicker of the liquid crystal display device 10.

Specifically, the conventional liquid crystal panel has a specification in which the drain electrode potential cannot be confirmed. For this reason, the potential difference between the transparent electrode 18 and the common electrode 22 is adjusted while confirming the presence or absence of flicker by an optical sensor or visual inspection by an inspector so that the common voltage Vcom at which flicker is minimized is obtained. There was a need to adjust. Further, the adjustment method is analog, for example, by changing an electric signal such as a potential difference between the transparent electrode 18 and the common electrode 22 so that the flicker is minimized by visual observation or using a dedicated optical measuring instrument. It was common to adjust. On the other hand, in the present embodiment, by providing the inspection wiring 32, the potential of the drain electrode 17c can be directly confirmed, so it is not necessary to confirm the presence or absence of flicker. For this reason, it is possible to reduce the equipment related to the optical sensor for checking flicker, the number of inspectors, and the like, thereby reducing the scale of the entire inspection environment and the equipment cost. Furthermore, in this embodiment, since the common voltage Vcom can be determined based on the DC component Vd (DC) information, there is no error or work error for each worker in the adjustment, and the optimum common voltage Vcom is surely obtained. Can be determined.

In the present embodiment, the array substrate 11b is divided into a display area AA and a non-display area NAA surrounding the display area AA, and the TFT 17 to which the inspection wiring 32 is connected is arranged in the non-display area NAA of the array substrate 11b. The plurality of gate lines 19 and the plurality of source lines 20 are arranged in a dummy pixel region 31B formed by intersecting. According to such a configuration, the inspection wiring 32 is not routed to the pixel region 31A, and the display quality of the liquid crystal display device 10 is not impaired by providing the inspection wiring 32.

Further, in the present embodiment, the common electrode 22 that forms a capacitance Clc with the transparent electrode 18 is further provided. When the drain voltage Vd is AC driven, the common electrode 22 has a positive polarity. The DC component extraction unit 34 extracts the potential difference between the drain electrode 17c and the common electrode 22 and the potential difference between the drain electrode 17c and the common electrode 22 at the time of the negative polarity. A common voltage Vcom calculated based on the DC component is applied. According to such a configuration, by adjusting the common voltage Vcom, the potential difference between the common electrode 22 is substantially the same when the drain voltage Vd is positive and negative, and therefore flicker is prevented. It can suppress suitably.

Further, the memory 36 stores a set value of the common voltage Vcom, and a common voltage generation unit 37 that generates the common voltage Vcom based on the set value of the common voltage Vcom stored in the memory 36, and includes a test wiring 32 includes a terminal unit 33 that can be connected to an inspection device 40 that includes a DC component extraction unit 34, and the inspection device 40 includes a common voltage calculation unit 35 that calculates a common voltage Vcom. The common voltage Vcom calculated by the common voltage calculation unit 35 of the inspection apparatus 40 is written. According to such a configuration, by using the inspection device 40, adjustment until generation of the optimized common voltage Vcom does not require, for example, an optical unit for detecting flicker, and the inspector can visually check. Thus, it is possible to automatically perform the operation without checking the presence or absence of flicker and adjusting the liquid crystal display device manually.

In this embodiment, the memory 36 and the common voltage generator 37 are provided on the array substrate 11b. According to such a configuration, by providing the memory 36 and the common voltage generation unit 37 on the array substrate 11b, the liquid crystal display device 10 in which flicker is preferably suppressed can be realized.

Further, in the present embodiment, a CF substrate 11A that is opposed to the array substrate 11b and on which the color filter 11h is disposed, and a liquid crystal layer 11c that is sandwiched between the array substrate 11b and the CF substrate 11A are provided. Such a liquid crystal display device 10 can be applied as a liquid crystal display device to various uses, for example, a display such as a portable information terminal or a television receiver.

<Embodiment 2>
A second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the liquid crystal display device 110 in which the dummy pixel 30B described in the first embodiment is not provided and the inspection wiring 132 is formed in the display pixel 30A is shown. In addition, the overlapping description about the same structure, operation | movement, and effect as above-mentioned Embodiment 1 is abbreviate | omitted.

The inspection wiring 132 is connected to the drain electrode 17c of at least one display pixel 30A among the plurality of display pixels 30A provided in the display area AA. The display pixel 30A provided with the inspection wiring 132 is a display pixel 30A arranged around the display area AA, that is, a display pixel 30A adjacent to the non-display area NAA in consideration of the wiring path of the inspection wiring 132. It is preferable. The display pixel 30A provided with the inspection wiring 132 is different from the other display pixels 30A only in the presence or absence of the inspection wiring 132, and the other configurations such as the size, shape, wiring route, and the like of each electrode are the same. The drain voltage Vd of the other display pixel 30A can be estimated by measuring the drain voltage Vd of the display pixel 30A provided with the inspection wiring 132. The display pixel 30 A provided with the inspection wiring 132 can be said to be a drain voltage confirmation pixel for confirming the drain voltage Vd of the liquid crystal display device 110. The configuration of the inspection wiring 132 is the same as that of the above-described inspection wiring 32 of the first embodiment, and a description thereof will be omitted.

In this embodiment, the array substrate 11b is divided into a display area AA and a non-display area NAA surrounding the display area, and the TFT 17 to which the inspection wiring 132 is connected includes a plurality of gate wirings in the display area AA in the array substrate 11b. 19 and a plurality of source lines 20 are arranged in a pixel region 31A formed by crossing. According to such a configuration, even when it is difficult to secure the dummy pixel region 31B in the non-display region NAA with the narrowing of the frame of the liquid crystal display device 10, the voltage value of the drain electrode 17c in the pixel region 31A. The direct current component Vd (DC) can be extracted.

<Embodiment 3>
A third embodiment of the present invention will be described with reference to FIG. The liquid crystal display device 210 according to the third embodiment is different from the first embodiment described above in that the memory 236 and the common voltage generation unit 237 are provided on the control circuit board (circuit board) 12. In addition, the overlapping description about the same structure, operation | movement, and effect as above-mentioned Embodiment 1 is abbreviate | omitted.

When the liquid crystal display device 210 is manufactured, the inspection device 40 is connected to the terminal portion 33 of the inspection wiring 32 and connected to the memory 236 provided in the control circuit board 12 so that the common voltage Vcom can be written. Then, in the liquid crystal display device 210 connected to a power source (not shown), the dummy pixel 30B is AC driven over a predetermined frame period, and the electrical signal of the drain voltage Vd (AC) of the drain electrode 17c is supplied to the inspection wiring 32. Directly into the inspection apparatus 40 via Then, in the inspection device 40, the set value of the optimized common voltage Vcom is written in the memory 236 through the direct current component extraction unit 34 and the common voltage calculation unit 35 sequentially. Then, when displaying the liquid crystal display device 110, the common voltage Vcom is generated by the common voltage generation unit 237 based on the set value of the common voltage Vcom stored in the memory 236. The common voltage Vcom generated by the control circuit board 12 is applied to the common electrode 22 through the flexible board 13.

According to such a configuration, even if it is difficult to provide the memory 236 and the common voltage generation unit 237 on the array substrate 11b with the narrowing of the frame of the liquid crystal display device 210, the memory 236 and the common voltage generation unit By providing 237 on the control circuit board 12, it is possible to realize the liquid crystal display device 210 in which flicker is preferably suppressed.

<Embodiment 4>
A fourth embodiment of the present invention will be described with reference to FIG. The liquid crystal display device 310 of the fourth embodiment is different from the first embodiment described above in that it includes a direct current component extraction unit 334. In addition, the overlapping description about the same structure, operation | movement, and effect as above-mentioned Embodiment 1 is abbreviate | omitted.

The DC component extraction unit 334 is a circuit unit provided in the non-display area NAA of the array substrate 11b in the liquid crystal display device 310. Similarly, a dummy pixel 30B is formed on the array substrate 11b. In this embodiment, the inspection wiring 32 connected to the drain electrode 17c of the dummy pixel 30B is connected to the terminal portion 33 or the external inspection device 40. It is directly connected to the DC component extraction unit 334 without a connection wiring. Then, the DC component extraction unit 334 processes the electrical signal of the drain voltage Vd taken from the drain electrode 17c of the dummy pixel 30B, and extracts the DC component Vd (DC).

Further, the liquid crystal display device 310 includes a common voltage generation unit 337 that generates a common voltage Vcom equivalent to the direct current component Vd (DC) based on the direct current component Vd (DC) information extracted by the direct current component extraction unit 334. Similar to the DC component extraction unit 334, the common voltage generation unit 337 is a circuit unit provided in the non-display area NAA in the array substrate 11b. In other words, in the present embodiment, even when the liquid crystal display device 310 is in use, the setting value of the common voltage Vcom can be appropriately optimized in accordance with the change in the direct current component Vd (DC) value. For this reason, the potential difference between the pixel electrode 18A and the common electrode 22 is substantially the same for each frame, regardless of the variation in the value of the drain voltage Vd (ΔV value).

In the present embodiment, the liquid crystal display device 310 further includes a DC component extraction unit 334 and a common voltage generation unit 337 that generates the common voltage Vcom based on the DC component extracted by the DC component extraction unit 334. According to such a configuration, the common voltage Vcom can be appropriately adjusted not only when the liquid crystal display device 310 is manufactured but also when the liquid crystal display device 310 is used. For example, flicker occurs due to a change in temperature or the like. Can be suppressed.

Specifically, even if the liquid crystal display device is adjusted so that the flicker is minimized during the manufacturing process, flicker may occur due to, for example, a change in the temperature environment according to the usage situation. . This is because the values of the parasitic capacitance Cgd, capacitance, Clc, and storage capacitance Ccs change depending on the temperature, that is, the above-described ΔV changes depending on the temperature, so that the optimum flicker is minimized. This is because the value of the common voltage Vcom and the like also changes depending on the environment such as temperature. On the other hand, in the present embodiment, the change in ΔV can be offset by changing the common voltage Vcom in accordance with the change in the parasitic capacitance Cgd, the electrostatic capacitance, Clc, and the storage capacitance Ccs, that is, ΔV. As a result, the set value of the common voltage Vcom is appropriately optimized, and the display quality can be maintained regardless of changes in the temperature environment or the like.

<Embodiment 5>
A fifth embodiment of the present invention will be described with reference to FIG. The liquid crystal display device 410 according to the fifth embodiment further includes a common voltage calculation unit 435 in the liquid crystal display device 310 according to the fourth embodiment, and the DC component Vd (DC) information output from the DC component extraction unit 434 is the common voltage calculation. The difference is that the set value of the common voltage Vcom calculated there is input to the common voltage generation unit 437 via the unit 435. In addition, the overlapping description about the same structure, operation | movement, and effect as above-mentioned Embodiment 1 is abbreviate | omitted.

The common voltage calculation unit 435 has a function of converting the DC component Vd (DC) information into a set value of the common voltage Vcom, and is set in advance based on the DC component Vd (DC) information obtained by the DC component extraction unit 434. The set value of the common voltage Vcom is calculated by the converted equation. Similar to the DC component extraction unit 434 and the like, the common voltage generation unit 437 is a circuit unit provided in the non-display area NAA of the array substrate 11b in the liquid crystal display device 410.

In the present embodiment, the liquid crystal display device 410 includes a DC component extraction unit 434 and a common voltage calculation unit 435 that calculates a set value of the common voltage Vcom based on the DC component Vd (DC) extracted by the DC component extraction unit 434. And a common voltage generation unit 437 that generates the common voltage Vcom based on the set value of the common voltage Vcom calculated by the common voltage calculation unit 435. According to such a configuration, even if it is difficult to directly generate the common voltage Vcom from the direct current component Vd (DC) due to design constraints, the common voltage calculation unit 435 sets the set value of the common voltage Vcom. The common voltage Vcom can be generated based on the calculation.

<Embodiment 6>
A sixth embodiment of the present invention will be described with reference to FIG. The liquid crystal display device 510 according to the sixth embodiment further includes a memory 536 in the liquid crystal display device 410 according to the fifth embodiment, and the setting value of the common voltage Vcom calculated by the common voltage calculation unit 535 is written into the memory 536. The difference is that the set value of the common voltage Vcom stored in the memory 536 is input to the common voltage generation unit 537. The memory 536 is a circuit unit provided in the non-display area NAA of the array substrate 11b in the liquid crystal display device 510, similarly to the DC component extraction unit 534 and the like. In addition, the overlapping description about the same structure, operation | movement, and effect as above-mentioned Embodiment 1 is abbreviate | omitted.

In the present embodiment, the liquid crystal display device 510 includes a DC component extraction unit 534 and a common voltage calculation unit 535 that calculates a set value of the common voltage Vcom based on the DC component Vd (DC) extracted by the DC component extraction unit 534. A memory 536 that stores the set value of the common voltage Vcom calculated by the common voltage calculation unit 535, and a common voltage generation unit 537 that generates the common voltage Vcom based on the set value of the common voltage Vcom stored in the memory 536. And comprising. According to such a configuration, the load on the DC component extraction unit 534 and the common voltage calculation unit 535 is reduced by generating the common voltage Vcom based on the set value stored in the memory 536 for a certain period. Can do.

<Embodiment 7>
A seventh embodiment of the present invention will be described with reference to FIG. The liquid crystal display device 610 of the seventh embodiment is different from the liquid crystal display device 10 of the first embodiment in that a plurality of inspection wirings 632 (two in this embodiment) are provided. In addition, the overlapping description about the same structure, operation | movement, and effect as above-mentioned Embodiment 1 is abbreviate | omitted.

In this embodiment, the inspection wiring 632 includes two inspection wirings 632A and 634B branched from the drain electrode 17c. According to such a configuration, when one of the inspection wirings 632A and 634B is disconnected at the time of manufacture, the other inspection wiring can be used as a backup, and therefore the array substrate 11b cannot be used. It can also be expected to improve the yield, such as eliminating the need for a state.

<Eighth embodiment>
An eighth embodiment of the present invention will be described with reference to FIG. The liquid crystal display device 710 of the eighth embodiment is different from the liquid crystal display device 10 of the first embodiment in that the inspection wiring 32 is arranged on the dummy pixel 30B, and the dummy wiring 738 is provided on the display pixel 30A. In addition, the overlapping description about the same structure, operation | movement, and effect as above-mentioned Embodiment 1 is abbreviate | omitted.

The dummy wiring 738 is connected to the drain electrode 17c provided in the display pixel 30A, and is routed in the same manner as the inspection wiring 32. On the other hand, the dummy wiring 738 is used as a DC component extraction unit that extracts a DC component of the voltage value of the drain electrode 17c. Not connected. In other words, the capacitance formed between the dummy wiring 738 and other electrodes and wirings in the display pixel 30A is the same as that between the inspection wiring 32 and other electrodes and wirings in the dummy pixel 30B. It is equivalent to the capacitance formed by In the present embodiment, the dummy wiring 738 is formed corresponding to the drain electrode 17c of all the display pixels 30A except the dummy pixel 30B.

According to such a configuration, the dummy wiring 738 is also provided in the region 31 where the inspection wiring 32 is not arranged among the regions 31 formed by the intersection of the plurality of gate wirings 19 and the plurality of source wirings 20. This arrangement prevents the electrical characteristics of the region 31 (dummy pixel region 31B) in which the inspection wiring 32 is disposed and the region 31 (pixel region 31A) in which the inspection wiring 32 is not disposed from being different. can do. As a result, the drain voltage Vd of the display pixel 30A can be estimated from the drain voltage Vd captured from the inspection wiring 32 more preferably.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In addition to the above-described embodiments, for example, in the configuration in which the inspection wiring is provided in the display pixel of Embodiment 2, the dummy wiring disclosed in Embodiment 8 is further added to the display pixel in which the inspection wiring is not provided. The configuration may be provided, and the configurations of the respective embodiments may be appropriately combined without departing from the gist thereof.

(2) In the embodiment described above, the method of adjusting the common voltage applied to the common electrode in order to adjust the flicker is exemplified, but the method of adjusting the flicker is not limited to this. For example, in order to adjust flicker, the voltage value applied to the electrodes other than the common electrode may be adjusted as appropriate. In addition to the voltage value, the voltage application time per unit time applied to each electrode may be appropriately set. You may adjust.

(3) In the above-described embodiment, a configuration in which one drain voltage check pixel (a dummy pixel, a display pixel provided with a test wiring) is provided is exemplified, but the number of drain voltage check pixels is not limited thereto. I can't. A plurality of drain voltage confirmation pixels may be provided.In that case, a common voltage setting value or the like is set based on an average value of a plurality of DC component information obtained from the plurality of drain voltage confirmation pixels. You may decide.

(4) In each of the embodiments described above, the reference electrode in the common electrode or the auxiliary capacitance wiring is exemplified as having a constant potential between the positive polarity and the negative polarity of the drain electrode. The present invention can also be applied to a configuration in which the reference potential varies.

(5) In each of the above-described embodiments, the reference potential applied to the common electrode and the reference potential applied to the auxiliary capacitance wiring are shown to be the same potential. However, the reference potential applied to the common electrode is described above. The present invention can also be applied to a case where the reference potential applied to the auxiliary capacitor wiring is different from the reference potential.

(6) In each of the embodiments described above, the TFT is exemplified as the switching element of the liquid crystal display device. However, the present invention can be applied to a liquid crystal display device using a switching element other than the TFT (for example, a thin film diode (TFD)). The present invention can be applied to a liquid crystal display device for monochrome display in addition to a liquid crystal display device for color display.

(7) In each of the above-described embodiments, the FFS type liquid crystal panel is exemplified, but the present invention can be applied to, for example, an IPS type liquid crystal panel. Furthermore, the present invention can also be applied to a VA liquid crystal panel or an MVA liquid crystal panel in which a common electrode is formed on the CF substrate side.

(8) In each of the embodiments described above, the driver is mounted directly on the array substrate by COG, but the driver is mounted on a flexible substrate connected to the array substrate via the ACF. It is included in the present invention.

(9) In each of the above-described embodiments, the liquid crystal panel having a vertically long rectangular shape is illustrated, but the shape of the liquid crystal panel is not limited thereto. For example, the present invention can be applied to a liquid crystal panel having a horizontally long square shape or a liquid crystal panel having a square shape.

(10) The present invention includes a configuration in which a functional panel such as a touch panel or a parallax barrier panel (switch liquid crystal panel) is attached to the liquid crystal panel described in each embodiment. In addition, a liquid crystal panel in which a touch panel pattern is directly formed is also included in the present invention.

(11) In each of the above-described embodiments, a transmissive liquid crystal display device including a backlight device that is an external light source is illustrated. However, the present invention is applied to a reflective liquid crystal display device that performs display using external light. In this case, the backlight device can be omitted.

(12) In each of the above embodiments, a liquid crystal panel having a configuration in which a liquid crystal layer is sandwiched between a pair of substrates has been exemplified. However, a display panel in which functional organic molecules other than a liquid crystal material are sandwiched between a pair of substrates. The present invention is also applicable to.

(13) In each of the above embodiments, a liquid crystal display device using a liquid crystal panel as an example of the display panel has been illustrated. However, other types of display panels (PDP (plasma display panel), organic EL panel, CRT ( The present invention is also applicable to a liquid crystal display device using a cathode ray tube (Cathode Ray Tube) or EPD (Electrophoretic Display Panel). In that case, the backlight device can be omitted.

(14) In each of the embodiments described above, the case where a liquid crystal panel is used as the display panel has been described. For example, a MEMS (Micro Electro Mechanical Systems) display panel that displays an image using light from a backlight device is used. It is also possible to use it. In this MEMS display panel, a number of minute mechanical shutters constituting display pixels are arranged in a plane in a matrix, and the opening and closing of each mechanical shutter is individually controlled, so that each display pixel is controlled by a backlight device. By adjusting the amount of transmitted light related to the light, an image with a predetermined gradation can be displayed.

(15) In each of the above-described embodiments, it is classified as small or medium-sized, and is a portable information terminal, a mobile phone (including a smartphone), a notebook computer (including a tablet notebook computer), a digital photo frame, and a portable game machine. In addition, liquid crystal panels used for various electronic devices such as electronic ink paper are exemplified, but the present invention is also applicable to liquid crystal panels classified into medium-sized or large-sized (super-large) screens having a screen size of, for example, 20 inches to 90 inches. Applicable. In that case, the liquid crystal panel can be used for an electronic device such as a television receiver, an electronic signboard (digital signage), or an electronic blackboard.

10, 110, 210, 310, 410, 510, 610, 710 ... liquid crystal display device (display device), 11a ... CF substrate, 11b ... array substrate, 11c ... liquid crystal layer, 11h ... Color filter, 17 ... TFT (switching element), 17a ... Gate electrode, 17b ... Source electrode, 17c ... Drain electrode, 18 ... Transparent electrode (pixel part), 18A ... Pixel electrode, 18B ... dummy pixel electrode, 19 ... gate wiring, 20 ... source wiring, 22 ... common electrode, 31 ... area, 31A ... pixel area, 31B ...

dummy Pixel region

31, 132, 632... Inspection wiring, 33... Terminal part, 34, 334, 434, 534 ... DC component extraction part, 35 435, 535. , 236, 536 ... Memory (storage unit), 37, 237, 337, 437, 537 ... Common voltage generation unit, 0 ... inspection apparatus, 738 ... dummy wiring

Claims

A substrate,
A plurality of gate wirings arranged in parallel on the substrate;
A plurality of source wirings arranged in parallel across the gate wiring on the substrate;
A plurality of transparent electrodes respectively disposed in a region formed by intersecting a plurality of the gate lines and the plurality of source lines;
A plurality of switching elements each disposed in the region and having a gate electrode connected to the gate wiring, a source electrode connected to the source wiring, and a drain electrode connected to the transparent electrode;
An inspection wiring connected to the drain electrode of at least one switching element of the plurality of switching elements and connectable to a DC component extraction unit for extracting a DC component of a voltage applied to the drain electrode; A display device comprising:
The substrate is divided into a display area and a non-display area surrounding the display area,
The switching element connected to the inspection wiring is disposed in a dummy pixel region formed by crossing a plurality of the gate wirings and a plurality of the source wirings in the non-display region of the substrate. Item 4. The display device according to Item 1.
The substrate is divided into a display area and a non-display area surrounding the display area,
2. The switching element to which the inspection wiring is connected is disposed in a pixel region formed by intersecting a plurality of the gate wirings and a plurality of the source wirings in the display region of the substrate. The display device described in 1.
A common electrode that forms a capacitance with the transparent electrode;
When the drain voltage applied to the drain electrode is an AC voltage, the common electrode includes a potential difference between the drain electrode and the common electrode at the positive polarity and the drain electrode at the negative polarity. The common voltage calculated based on the DC component extracted by the DC component extraction unit is applied so that the potential difference between the common electrode and the common electrode is substantially the same. Item 1. A display device according to item 1.
A storage unit for storing a set value of the common voltage;
A common voltage generation unit that generates the common voltage based on a set value of the common voltage stored in the storage unit;
The inspection wiring has a terminal portion that can be connected to an inspection apparatus including the DC component extraction unit,
The inspection apparatus further includes a common voltage calculation unit that calculates a set value of the common voltage,
The display device according to claim 4, wherein the setting value of the common voltage calculated by the common voltage calculation unit of the inspection apparatus is written in the storage unit.
The display device according to claim 5, wherein the storage unit and the common voltage generation unit are provided on the substrate.
A circuit board for supplying a voltage to the common electrode;
The display device according to claim 5, wherein the storage unit and the common voltage generation unit are provided on the circuit board.
The DC component extraction unit;
The display device according to claim 4, further comprising: a common voltage generation unit that generates the common voltage based on the DC component extracted by the DC component extraction unit.
The DC component extraction unit;
A common voltage calculation unit that calculates a set value of the common voltage based on the DC component extracted by the DC component extraction unit;
The display device according to claim 4, further comprising: a common voltage generation unit that generates the common voltage based on a set value of the common voltage calculated by the calculation unit.
The DC component extraction unit;
A calculation unit that calculates a set value of the common voltage based on the DC component extracted by the DC component extraction unit;
A storage unit for storing a setting value of the common voltage calculated by the common voltage calculation unit;
The display device according to claim 4, further comprising: a common voltage generation unit that generates the common voltage based on a set value of the common voltage stored in the storage unit.
The display device according to any one of claims 1 to 10, wherein a plurality of the inspection wirings are branched from the drain electrode.
The DC component extraction unit that is connected to the drain electrode of at least one switching element among the plurality of switching elements and is arranged in the same manner as the inspection wiring, and extracts a DC component of a voltage value of the drain electrode. The display device according to claim 1, further comprising a dummy wiring not connected to the display.
The counter substrate according to any one of claims 1 to 12, further comprising: a counter substrate facing the substrate and having a color filter disposed thereon; and a liquid crystal layer sandwiched between the substrate and the counter substrate. The display device described.