TW201516549A - Electrochromic display panel - Google Patents

Abstract

Provided is an electrochromic display panel in which enlargement of pixel color surface area can easily be controlled without losing reflectivity and image quality. The electrochromic display panel is provided with a substrate on which part of a layered structure is formed by data lines extending in a first direction and scanning lines extending in a second direction crossing the data lines as well as pixel electrodes and thin film transistors which are disposed so as to correspond to a crossing area of the data lines and the scanning lines. The electrochromic display panel is also provided with shield electrodes that cover the data lines and scanning lines from above and are formed with a width 2 ~ 4 [mu]m wider than the data lines and the scanning lines.

Description

Electrochromic display panel

The present invention relates to an electrochromic display panel, and more particularly to an electrochromic display panel in which a shield electrode is disposed between pixels and a method of manufacturing the same.

In recent years, liquid crystals using backlights have been the mainstream in terms of information display panels. However, the burden on the eyes is large and it is not suitable for long-term continuous use.

Therefore, in a reflective display device having a small burden on the eyes, a display panel having a pair of opposed electrodes and an electrophoretic display layer disposed between the electrodes is proposed as an electrophoretic display device (for example, Refer to Patent Document 1).

Since the electrophoretic display device displays characters or images by reflected light in the same manner as the printed paper surface, the electrophoretic display device has a small load on the eyes and is suitable for the operation of continuously watching the screen for a long time.

However, the white reflectance of the electrophoretic display medium whose reflectance is changed by moving the charged particles of white and black is affected by the black charged particles, resulting in insufficient reflectance. Therefore, there is a need for a reflective display device that uses other forms of high reflectivity.

As one of them, the electrochromic display method is attracting attention, and it uses an electrochromic material whose electric coloring is changed, because it is a layer. Since the number is small and the structure is simple, high reflectance can be expected.

On the other hand, there is no problem of an electrochromic method in which a clear voltage threshold is not present, which causes an increase in the area of the colored pixel due to an increase in the electric field between the electrodes.

Therefore, as a driving method of electrochromic, it has been proposed to arrange the display electrode and the counter electrode in the same plane shape (see Patent Document 2), and to arrange the display electrode and the counter electrode at 90 degrees. The passive driving method of the surface (see Patent Document 3) and the matrix driving method in which the active elements are arranged in the pixel unit (see Patent Document 4), but any of the driving methods causes the above problem. It is difficult to perform high-quality display by the color change method.

In order to solve this problem, it has been proposed to form a partition wall having a vertically porous structure in the electrolyte layer to suppress an increase in electric field (see Patent Document 5).

However, once the partition wall of the vertical porous structure is formed, the electrolyte does not sufficiently extend over the electrochromic layer adjacent to the partition wall portion, so that the speed of coloring change and the coloring density become uneven, and as a result, reflectance and image quality are caused. reduce. Further, the above-described fine processing of the partition walls is low in mass productivity and is not practical.

Further, it has been proposed to prevent the electric field from affecting adjacent pixels by forming the partition walls in units of pixels in order to suppress the enlargement of the pixels (Patent Document 6).

However, the expansion of the electric field itself is not suppressed.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 50-015115

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2006-323191

[Patent Document 3] Japanese Laid-Open Patent Publication No. 2012-168439

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2002-287173

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2008-033083

[Patent Document 6] Japanese Laid-Open Patent Publication No. 2010-224240

As described above, in order to improve the expansion of the pixel colored area due to the expansion of the electric field, it is proposed to provide the partition wall of the vertical porous structure to the electrolyte layer or the like. However, when such a proposal is made and the driving is performed, the electrolyte does not sufficiently extend over the electrochromic layer adjacent to the partition portion, and the speed of coloring change and the coloring density become uneven, and as a result, the reflectance and the image quality are lowered. Further, the microfabrication of the above-mentioned partition walls is low in mass productivity and is not practical. Accordingly, it is an object of the present invention to provide an electrochromic display panel which can easily suppress expansion of a pixel colored area without impairing such reflectance or image quality.

The various aspects of the invention of the present invention are as follows.

First, an electrochromic display panel is provided on a substrate by a data line extending in a first direction, a scanning line extending in a second direction intersecting the data line, and being disposed so as to correspond to an intersection of the data line and the scanning line. The pixel electrode and the thin film transistor form a part of the laminated structure, and the shield electrode is provided from the data line and the scan. The line is covered above and formed to have a width of 2 μm or more and 4 μm or less wider than the data line and the scanning line.

Furthermore, an electrochromic display panel in which an insulating film is provided on the surfaces of the scanning lines and the data lines.

Further, an electrochromic display panel in which a width of an insulating film formed on a scanning line and a data line is larger than a width of a shield electrode on the scanning line and the data line.

Further, an electrochromic display panel in which the shield electrode is configured to block light on the thin film transistor.

Further, an electrochromic display panel in which the thickness of the shield electrode is 150 nm or more and 400 nm or less.

Further, an electrochromic display panel in which an insulating film is provided on a surface of a shield electrode.

Further, an electrochromic display panel in which a partition wall between adjacent pixels is provided on a surface of a shield electrode.

Generally, in an adjacent pixel, when a current flows through one of the pixel electrodes, the electric field in the electrolyte layer is enlarged, and the color change of the display layer on the opposite electrode is expanded to be larger than the area of the electrode, and the adjacent electrode is on the adjacent electrode. The display layer will also change color.

However, as shown in the present invention, the shield electrode is disposed above the data line and the scan line between the pixels and formed into a wide width, thereby suppressing an increase in the electric field between adjacent pixels, and the color change between the pixels is small, and can be performed. Clear color changes.

Furthermore, in the electrochromic mode, the present invention is at resolution In a higher panel (100 ppi or more), the electric field between adjacent pixels can be suppressed from expanding, so that a high-definition image can be displayed on a high-resolution panel.

With such a configuration, an electrochromic display medium capable of improving the expansion of the pixel area of the display medium in the electrochromic method and the problem of low-quality display can be produced.

1a‧‧‧ scan line

3a‧‧‧Information line

6a‧‧‧pixel electrode

9a‧‧‧Channel area

10‧‧‧TFT array substrate

11‧‧‧1st interlayer insulating film

12‧‧‧Second interlayer insulating film

12a‧‧‧Shield electrode

14‧‧‧Charge storage layer

15‧‧‧ electrolyte layer

16‧‧‧Display layer

17‧‧‧ opposite electrode

18‧‧‧ opposite substrate

19‧‧‧Electrochromic display layer

20‧‧‧TFT

30‧‧‧ Capacitance

40‧‧‧ partition wall

200‧‧‧electrode

1 is an equivalent circuit of various elements, wirings, and the like which constitute a plurality of pixels in a matrix form in an image display region of an electrochromic display panel.

2 is a plan view of a plurality of pixels adjacent to a TFT substrate on which a data line, a scanning line, a shield electrode, and a pixel electrode are formed.

3 is a plan view showing an element in which the relationship between the data line, the scanning line, the shield electrode, and the pixel electrode in FIG. 2 is extracted.

Fig. 4 is a cross-sectional view taken along line A-A' of Fig. 2, showing a cross-sectional view of an electrochromic display panel according to an embodiment in which an electrochromic material of the present invention is used.

Fig. 5 is a cross-sectional view taken along line A-A' of Fig. 2, showing a state in which a partition wall is formed on a shield electrode.

[Formation of the Invention]

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The electrochromic display panel of the present invention can be driven by active matrix by providing a data line, a scan line, a pixel electrode, and a thin film transistor.

First, the configuration of the pixel portion of the electrochromic display panel according to the first embodiment of the present invention will be described with reference to FIG. 1 to FIG. First, FIG. 1 is an equivalent circuit showing various elements, wirings, and the like which form a plurality of pixels in a matrix shape, which constitute an image display region of an electrochromic display panel. 2 is a plan view showing a plurality of pixels formed with a data line, a scan line, a shield electrode, and a pixel electrode adjacent to the TFT substrate, and FIG. 3 is a drawing for displaying the data line and the scan line in FIG. A plan view of the elements of the relationship between the shield electrode and the pixel electrode.

Figure 4 is a cross-sectional view taken along line A-A' of Figure 2; Moreover, FIG. 5 is a cross-sectional view showing a state in which a partition wall is formed on the shield electrode. Further, in FIGS. 4 and 5, the thickness/member of each layer is set to be identifiable on the drawing surface, so that the layers and members are changed in proportion.

In FIG. 1, a plurality of pixels forming a matrix in the video display region of the present embodiment are respectively formed with a pixel electrode 6a and a TFT 20 for ON/OFF (on/off) control of the pixel electrode 6a. The data line 3a to which the video signal is supplied is electrically connected to the drain of the TFT 20.

The video signals written on the data line 3a are supplied in line order in the order of D1, D2, ‧‧, and Dn.

Further, the scanning line 1a is electrically connected to the gate of the TFT 20, and a voltage is applied in the order of the scanning signals G1, G2, ‧‧, and Gn in the order of the predetermined pulse. Further, the pixel electrode 6a is electrically connected to the source of the TFT 20, and the TFT 20 as a switching element is turned ON only for a certain period of time, and the image signal supplied from the data line 3a is D1 and D2. , ‧‧‧Dn with established timing Write.

The image signals D1, D2, ‧‧‧, Dn written in the electrochromic display panel via the pixel electrode 6a are held between the counter electrodes formed on the entire surface of the display region covering the opposite substrate.

Here, in order to hold the image signal, the capacitor 30 is added in parallel with the capacitance of the electrochromic display element formed between the pixel electrode 6a and the counter electrode. This capacitor 30 includes an electrode 200 that is fixed at a constant potential.

Hereinafter, the actual configuration of the electrochromic display panel that realizes the above-described circuit operation by the scanning line 1a, the data line 3a, the TFT 20, and the like will be described with reference to FIGS. 2 to 4 .

First, in FIG. 2 and FIG. 3, the pixel electrodes 6a are provided in a plurality of rows on the TFT array substrate 10 in a matrix, and the scanning lines 1a and the data lines 3a are arranged along the longitudinal and lateral directions of the plurality of pixel electrodes 6a. A shield electrode 12a is provided on each of the scanning line 1a and the data line 3a.

The scanning line 1a, the data line 3a, and the shield electrode 12a are formed of a conductive film. Further, the scanning line 1a includes a channel region 9a displayed in a hatched area, and the scanning line 1a has a function as a gate electrode. A channel region 9a is provided in the vicinity of the intersection of the scanning line 1a and the data line 3a, and a pixel switching TFT 20 is disposed therein. The pixel switching TFT 20 is provided with a gate electrode of the scanning line 1a. The shield electrode 12a is disposed so as to have a thickness of 150 nm or more and 400 nm or less, and is shielded from light on the TFT 20.

As shown in FIG. 4, the electrochromic display panel includes a TFT array substrate 10, which is a substrate in which a TFT array composed of a glass substrate is disposed, and a counter substrate 18; It is composed of a transparent substrate disposed opposite to the TFT array substrate 10.

As shown in FIG. 4, a pixel electrode 6a is provided on the TFT array substrate 10 side, and a charge storage layer 14 is applied to the pixel electrode 6a. The pixel electrode 6a is made of, for example, an aluminum film, and the counter electrode 17 is provided on the entire surface of the display substrate 18 so as to cover the entire surface of the display region, and is provided with a transparent conductive film made of a transparent conductive film such as an ITO film. Layer 16. The electrolyte layer 15 is provided between the TFT array substrate 10 and the opposite substrate 18 which are disposed opposite each other in this manner, thereby forming the electrochromic display layer 19.

On the TFT array substrate 10, each of the structures including the pixel electrodes 6a is provided in a laminated structure. A first interlayer insulating film 11 is provided between the scanning line 1a and the data line 3a, and a second interlayer insulating film 12 is provided between the scanning line 1a and the data line 3a and the shield electrode 12a, and the second interlayer insulating film is provided. The width of 12 is formed to be larger than the width of the shield electrode 12a, and it is possible to prevent short-circuiting between the aforementioned elements. Further, although not shown, an insulating film may be provided on the surface of the shield electrode 12a.

In the electrochromic display layer 19, a positive or negative voltage or a flowing current can be applied between the pixel electrode 6a and the counter electrode 17, and an electric field is generated in the electrochromic display layer 19 by changing the voltage of the data line 3a. Layer 16 and charge storage layer 14 are redoxed.

When the pixel electrode 6a is a positive electrode, the charge storage layer 14 loses electrons and oxidizes, and the display layer 16 of the counter electrode 17 which is a counter electrode is supplied with electrons to be reduced. Conversely, when the pixel electrode 6a is a negative electrode, the charge storage layer 14 is reduced by supply of electrons, and the display layer 16 loses electrons and oxidizes.

Along with the redox of this display layer, the absorption wavelength region of the visible light appears or moves, whereby the color changes.

In the case where the display layer does not absorb visible light and is colorless and transparent, color development by the reflective material dispersed to the electrolyte layer 15 can be observed.

Next, the effects of the present invention will be described with reference to Fig. 4 .

In a general adjacent pixel configuration, when a current flows in one of the layers to promote the color change of the display layer, in addition to the electric field applied in the vertical direction of the pixel electrode 6a and the counter electrode 17, there is a fear that the following phenomenon occurs: The influence of the transverse electric field parallel to the substrate surface, the color change range of the display layer extends to the display area of the adjacent pixel, the coloring change of the area adjacent to the pixel, or the explicit display boundary of the adjacent pixel does not appear.

As shown in FIG. 4, in the configuration according to the present invention, the shield electrode 12a connected to the external terminal is disposed from the external drive circuit with the same potential or an arbitrary potential as the counter electrode 17 between the pixels, only at some When one of the pixels flows a current, the color change and the electric field increase in the display layer between the pixels are suppressed on the shield electrode without being affected by the electric field of the adjacent pixel. As a result, only the display layer corresponding to the pixel electrode causes a coloring change, and the display region of the pixel electrode adjacent to the pixel electrode that promotes the coloring change does not cause a coloring change, and a clear display region with the adjacent pixel appears, and a high-quality image is displayed.

The width of the shield electrode 12a is preferably 2 μm or more and 4 μm or less larger than the data line 3a and the scanning line 1a. When the edge from the scanning line 1a, the data line 3a, and the TFT 20 region to the edge of the shield electrode 12a is less than 2 μm, damage (etching agent, etc.) due to the etching of the shield electrode 12a in the forming step may cause film reduction, which may result in light leakage. And cause deterioration of TFT characteristics, or Concerns about damage to the electric field suppression effect. Further, when the edge of the scanning line 1a, the data line 3a, and the TFT 20 region is formed to be wider than the edge of the shield electrode 12a, in the application of the high-resolution panel (100 ppi or more), the aperture ratio is The possibility of sacrifice.

As shown in FIG. 5, in the configuration of the present invention, by providing the barrier film 40 of the thick film on the shield electrode 12a, the adjacent pixels can be three-dimensionally separated, and the electric field can be effectively suppressed.

In the above embodiment, an active matrix electrochromic display panel in which a thin film transistor is provided for each pixel is used, but the present invention is not limited thereto. For example, it may also be a passive matrix electrochromic display panel.

Hereinafter, the materials, members, and configurations used in the present invention will be described.

The formation of the electrochromic display layer is composed of an electrochromic material, a supporting electrolyte, a reflective material, and a charge storage material.

As the electrochromic material, general organic compounds and inorganic compounds can be used. Specifically, it can be mentioned that: viologen, thiophene Low molecular systems such as steroids, terpenoids, styryl spiropyrans, pyrazolines, fluoran, styrylpyrazine, phthalocyanines, etc. Electromechanical color-changing compound; conductive polymer compound of polyaniline, polythiophene, polypyrrole, etc.; titanium oxide, molybdenum oxide, cerium oxide, cerium oxide, vanadium oxide, tungsten oxide, indium oxide, cerium oxide, nickel oxide, Prussian blue Or an inorganic electrochromic compound such as a Prussian blue-like body obtained by replacing a coordination metal with iron.

In addition, it is known that colorless dyeing is generally an organically supplied organic substance. The material can also be electrically colored or achromatic.

For example, leuco auramine, diaryl phthalide, polyarylcarbinol, mercapto golden amine, aryl golden amine, rose red B Electron-donating dye precursors such as guanamines, porphyrins, spiropyrans, and fluorescent yellow mothers.

Further, as for the low molecular material, a layer having a porous structure may be formed on the electrode layer with a mineral such as titanium oxide and adsorbed.

Regarding the method for forming the display layer, the above-mentioned electrochromic material can be directly used as a coating material or mixed with a binder to form a coating, and a screen printing, a micro gravure coater, an anastomosis coater can be used. A general coating method such as a kiss coater, a comma coater, a die coater, a bar coater, and a spin coater.

Further, the formation of the convex portion in cooperation with the pixel electrode can be formed by a patterning coating method such as screen printing or inkjet printing.

The supporting salt may, for example, be an inorganic ionic salt such as an alkali metal salt or an alkaline earth metal salt, a quaternary ammonium salt, an acid or a base. Further specific examples of the supporting salt include LiClO ₄ , LiBF ₄ , LiAsF ₆ , LiPF ₆ , LiCF ₃ SO ₃ , CF ₃ COOLi, KCl, NaClO ₃ , NaCl, NaBF ₄ , NaSCN, KBF ₄ , Mg. (ClO ₄ ) ₂ , Mg(BF ₄ ) ₂ and the like.

Examples of the reflective material dispersed in the electrolyte layer include magnesium oxide, barium sulfate, titanium oxide, and the like. Also, black material Examples of the material include carbon black composed of carbon such as lamp black or bone char, or black titanium powder produced from an inorganic material. Further, examples of the blue material include cobalt aluminate, cobalt chrome blue, and phthalocyanine; and examples of the red material include hydrazine and an azo compound. In order to disperse the reflective material in the electrolyte layer, the viscosity of the electrolyte layer may be increased by dissolving a polymer material such as an acrylic resin or a urethane resin in the electrolyte layer. Alternatively, a dispersing agent or a surfactant may be added.

The charge storage material can utilize the same material as the electrochromic material. However, it is preferably a stable material which is difficult to react with other compounds in both the oxidized body and the reduced body of Prussian blue or ferrocene.

The opposite substrate is formed with a transparent electrode formed on a transparent substrate. As the transparent substrate, polyethylene terephthalate (PET), or a plastic such as polycarbonate, polyamidamine, polyethylene naphthalate, polyether oxime, acrylic resin, polyvinyl chloride or the like can be used. Film, or glass, etc. The transparent electrode material user may be, for example, an indium oxide system such as ITO, a tin oxide-based or a zinc oxide-based conductive oxide having transparency. As the transparent electrode layer, a conventional technique such as a vapor deposition method, a sputtering method, or a CVD method can be used.

As the TFT array substrate, an active matrix electrode plate in which a thin transistor is used, which uses an amorphous germanium or a polysilicon used for driving a general liquid crystal panel, can be used. Alternatively, a back electrode plate may be used in which a large number of electrodes are arranged in a lattice shape on the front surface of the printed circuit board, and wiring is formed on the back surface by passing through the through holes, thereby enabling large-scale active matrix driving. .

The wiring of the shield electrode can be formed by using a known material and a forming method, and the material or the forming method thereof is not limited. Examples of the shielding electrode material include tantalum (Ta), aluminum (Al), and copper (Cu). .

Further, by forming the shield electrode on the thin film transistor, it is possible to suppress light from entering the TFT, and it is possible to reduce variations in characteristics of the TFT due to light.

The partition wall can be formed using a known material and a forming method, and the material or the forming method thereof is not limited, and examples of the partition wall material include a photoresist for a thick film. Further, the height of the partition wall is preferably 50% or more with respect to the total thickness of the electrochromic display layer.

Hereinafter, the present invention will be described in detail by way of examples and comparative examples. However, the present invention is not limited by the following description.

[Examples]

[Example 1]

<Production of front electrode substrate>

On a transparent electrode substrate obtained by forming indium tin oxide as an electrode on a glass of 100 mm square, as a electrochromic material, a dispersion of a water-soluble Prussian blue dispersion liquid of 1.0 mol/l was applied by a spin coater. The liquid was dried at 100 ° C for 5 minutes to obtain a surface electrode substrate having a coating film of about 0.5 μm.

Next, a coating liquid prepared by mixing 0.5 mol/l of Prussian blue and polyethylene glycol in pure water was mixed, and a pattern of 250 μm □ was printed on the front substrate by inkjet printing to obtain a width of about 10 μm and having a step difference from the coating film by an average of 0.4 μm Surface electrode substrate.

<Production of Back Electrode Substrate>

As a method of forming an element on the glass which is a back electrode plate, a film forming step by sputtering, a vapor deposition method, a CVD method, a masking step such as a photolithography method, or a film shape processing such as an etching method can be suitably performed. In this step, the first electrode is patterned, and the first interlayer insulating film is formed into a film, and a switching element (TFT) is patterned for each pixel, and then the second electrode is patterned. At this time, the contact holes are formed in advance by patterning the first electrode and the second electrode.

Here, the TFT (hydrogenated amorphous germanium (a-Si:H)) is generally formed by a plasma CVD method, a reactive sputtering method, or the like. For example, when an n-type hydrogenated amorphous germanium is formed by a plasma CVD method, it is decomposed by an RF discharge and deposited by using a decane (SiH ₄ ) or a higher decane and a phosphine (PH ₃ ) as a material gas. It is kept on a substrate having a temperature of 200 ° C or more and 300 ° C or less.

In the hydrogenated amorphous germanium formed by such a method, hydrogen contains about 10 atm% to about 20 atm%, and this hydrogen has an important influence on the determination of the properties of the hydrogenated amorphous germanium. The hydrogen contained in the hydrogenated amorphous germanium has a direct function of removing a dangling bond. Moreover, it also has the function of surface treatment when forming a film of hydrogenated amorphous germanium, and functions as a structural moderator of a network, and the effects of such functions are combined with the heat effect of the substrate temperature. Also indirectly reduces the dangling bonds.

That is, the Si-H bond in the hydrogenated amorphous yttrium reduces the unstable dangling bond and achieves structural sensitivity, by P (phosphorus, V group), B (boron , Group III) to achieve pn bonding by the same substituted dopant as crystalline Si. This property of hydrogen in hydrogenated amorphous germanium is an important property in the application of hydrogenated amorphous germanium to diodes or transistors.

Then, after the formation of the second electrode, a film forming step such as a sputtering method, a vapor deposition method or a CVD method, a mask step such as a photolithography method, or a film shape processing step such as an etching method is performed on the TFT. The second interlayer insulating film is patterned, and the shield electrode is patterned to have a width of 2 μm larger than the data line and the scanning line on the electrodes serving as the data lines and the scanning lines.

Here, the back electrode plate is a TFT substrate having a resolution of 102 ppi (pixel size: 250 μm) at a resolution of 15 μm in order to evaluate the applicability of a panel having a high resolution. Similarly to the front electrode substrate, the prepared Prussian blue dispersion was applied by a spin coater to obtain a back electrode substrate using Prussian blue as a charge holding layer.

In addition, 0.1 M potassium hexafluorophosphate and PMMA (Wako Pure Chemicals) and titanium oxide (R-830, manufactured by Ishihara Sangyo Co., Ltd.), which are electrolytes, were mixed with propylene carbonate to prepare an electrolyte solution.

<Production of Evaluation Substrate>

At the end of the back electrode substrate, an ultraviolet curable resin (TB3026E, manufactured by ThreeBond) in which beads having a diameter of about 100 μm were mixed was applied by a dispenser to form a dam. Then, the dam material was filled with the above-mentioned blended electrolyte solution, and the step portion of the step front electrode substrate was bonded to the inter-pixel portion, and light of 500 mJ/cm ² (420 nm) was applied and adhered.

<Evaluation of the production substrate>

(drive evaluation)

The LSI was mounted on the completed substrate, and 1.5 V was applied to one pixel of the back surface electrode for 2 seconds to confirm whether or not the coloring was changed from blue to transparent. The case where the coloring has changed without any problem is evaluated as "++", and only a part of the color change or the coloring is not changed is evaluated as "-".

(electrode film state evaluation)

For the edges of the scan lines, data lines, and TFT regions to the edges of the shield electrodes, observe with a microscope. In the state of formation of the electrode film, the case where no defects such as damage or film reduction were observed was evaluated as "++", and the case where defects such as damage or film reduction were observed was evaluated as "-".

(Applicable to panel evaluation)

For the panels having the respective line widths, the panel having the aperture ratio of the obtained panel is used for evaluation. Here, as an evaluation, the case where the aperture ratio of each panel is practically applied to the panel is evaluated as "++", and the case where the aperture ratio is practically used but the aperture ratio is sacrificed is evaluated as "+". The case where the problem occurred in practical use and the aperture ratio was sacrificed was evaluated as "-".

(Overview)

Based on the results of each evaluation project, a comprehensive evaluation is conducted. The evaluation criteria are as follows. The evaluation criteria set "++" to "good", "-" to "bad", and "++" to pass.

[Embodiment 2]

In addition to patterning the shield electrode on the electrode as the data line and the scan line, the pattern is formed to be 2.5 μm wider than the data line and the scan line. Example 1 is the same.

[Example 3]

The patterning electrode was patterned to be formed to be 3 μm wider than the data line and the scanning line on the electrodes as the data lines and the scanning lines, and the rest was the same as in the first embodiment.

[Example 4]

The patterning electrode was patterned to be 3.5 μm wider than the data line and the scanning line on the electrodes as the data lines and the scanning lines, and the rest was the same as in the first embodiment.

[Example 5]

The patterning electrode was patterned to be formed to be 4 μm wider than the data line and the scanning line on the electrodes as the data lines and the scanning lines, and the rest was the same as in the first embodiment.

[Comparative Example 1]

The patterning electrode was patterned to be formed to be 1 μm wider than the data line and the scanning line on the electrodes as the data lines and the scanning lines, and the rest was the same as in the first embodiment.

[Comparative Example 2]

The patterning electrode was patterned to be formed to be 5 μm wider than the data line and the scanning line on the electrodes as the data lines and the scanning lines, and the rest was the same as in the first embodiment.

[Comparative Example 3]

The patterning electrode was patterned to be 6 μm wider than the data line and the scanning line on the electrodes as the data lines and the scanning lines, and the rest was the same as in the first embodiment.

Table 1 shows the evaluation results of Examples 1 to 5 and Comparative Examples 1 to 3.

The LSI was mounted on the substrates prepared in Examples 1 to 5 and Comparative Examples 1 to 3, and 1.5 V was applied to one pixel of the back electrode in 2 seconds to promote coloration from blue to transparent. The pixel system was changed to a transparent portion of about 250 μm □ with the above-described step as the edge, and was observed as a white pixel by the titanium oxide of the electrolytic solution. Further, when the adjacent two pixels are promoted to change from blue to transparent, when the step difference between the pixels is also changed to be transparent, a continuous white pixel is observed. In Comparative Example 1, a portion having no coloring change was observed.

Further, as a result of observing the electrode film by a microscope, although the electrode films of Examples 1 to 5 and Comparative Examples 2 and 3 were not observed with defects such as damage or film reduction, it was observed in Comparative Example 1 that the shield electrode was formed. The film due to damage (etching agent, etc.) during etching of the step is reduced. This film is less preferable in quality because it reduces the deterioration of the TFT characteristics or the electric field suppressing effect due to light leakage.

Next, in the case of evaluation for a panel, in Examples 1 to 5, panelization can be performed without sacrificing the aperture ratio. In Comparative Example 1, since the film damage was observed, evaluation (not evaluated) suitable for the panel was not performed. In Comparative Examples 2 and 3, since the shield electrode was formed to allow a wide width to be applied to the panel or more, it was necessary to manufacture the panel at the expense of the aperture ratio.

From the above results, in the comprehensive evaluation, the shield electrode is patterned on the electrode as the data line and the scanning line to have a width wider than the data line and the scanning line by 2 μm or more and 4 μm or less and the composition obtained in this manner. The evaluation was "++ (good)", and it was judged that the pattern was formed to have a width of more than 4 μm, and the aperture ratio was evaluated as "- (inferior)", and the pattern was formed to be narrower than 2 μm. The situation is evaluated as "-(inferior)". It was confirmed that the shield electrode can be patterned to have a width wider than the data line and the scanning line by 2 μm or more and 4 μm or less, that is, good characteristics can be obtained with a resolution of 102 ppi.

From the examples 6 to 10, as panels having higher resolution than those of the first to fifth embodiments, evaluation of a panel having a resolution of 150.3 ppi (pixel size: 169 μm) was performed.

[Embodiment 6]

<Production of front electrode substrate>

A coating liquid obtained by mixing 0.5 mol/l of Prussian blue and polyethylene glycol in pure water and blending a pattern of 169 μm by inkjet printing was used, and the same procedure as in Example 1 was carried out. Step front electrode substrate.

<Production of Back Electrode Substrate>

The shield electrode is patterned to be 2 μm wider than the data line and the scan line on the electrode as the data line and the scan line, and the back electrode plate is a TFT substrate having a resolution of 150.3 ppi (pixel size 169 μm) and a distance between pixels of 15 μm. The back electrode substrate was obtained in the same manner as in Example 1 except for the rest.

<Production of Evaluation Substrate>

It was produced in the same manner as in Example 1.

<Evaluation of the production substrate>

The same evaluation was carried out in the same evaluation item as in Example 1.

[Embodiment 7]

The same procedure as in the sixth embodiment was carried out except that the shield electrode was patterned to be 2.5 μm wider than the data line and the scanning line on the electrodes as the data lines and the scanning lines.

[Embodiment 8]

The same procedure as in the sixth embodiment was carried out except that the shield electrode was patterned to be 3 μm wider than the data line and the scanning line on the electrodes as the data lines and the scanning lines.

[Embodiment 9]

The same procedure as in Example 6 was carried out except that the shield electrode was patterned to be 3.5 μm wider than the data line and the scanning line on the electrodes as the data lines and the scanning lines.

[Embodiment 10]

The same procedure as in the sixth embodiment was carried out except that the shield electrode was patterned to be 4 μm wider than the data line and the scanning line on the electrodes as the data lines and the scanning lines.

[Comparative Example 4]

The same procedure as in Example 6 was carried out except that the shield electrode was patterned to be 1 μm wider than the data line and the scanning line on the electrodes as the data lines and the scanning lines.

[Comparative Example 5]

The same procedure as in the sixth embodiment was carried out except that the shield electrode was patterned to be 5 μm wider than the data line and the scanning line on the electrodes as the data lines and the scanning lines.

[Comparative Example 6]

The same procedure as in the sixth embodiment was carried out except that the shield electrode was patterned to be 6 μm wider than the data line and the scanning line on the electrodes as the data lines and the scanning lines.

Table 2 shows the evaluation results of Examples 6 to 10 and Comparative Examples 4 to 6.

The LSI was mounted on the substrate prepared in Example 6 to Example 10 and Comparative Example 4 to Comparative Example 6, and the pixel on the back electrode was 2 seconds. When 1.5 V was applied for the time to promote the coloration from blue to transparent, the pixel system was changed to a transparent portion of about 250 μm □ with the above-described step as the edge, and a white pixel was observed by the titanium oxide of the electrolytic solution. Further, when the adjacent two pixels are promoted to change from blue to transparent, when the step difference between the pixels is also changed to be transparent, a continuous white pixel is observed. In Comparative Example 4, a portion having no coloring change was observed.

Further, as a result of observing the electrode film by a microscope, although the electrode films of Examples 6 to 10 and Comparative Examples 5 and 6 were not observed with defects such as damage or film reduction, it was observed in Comparative Example 4 that the shield electrode was formed. The film is reduced in the film due to damage (etching agent, etc.) at the time of etching. This film is less preferable in quality because it can deteriorate the deterioration of the TFT characteristics or the electric field suppressing effect due to light leakage.

Next, in the case of evaluation suitable for the panel, in Examples 6 to 10, panelization can be performed without sacrificing the aperture ratio. In Comparative Example 4, since the film damage was observed, evaluation (not evaluated) suitable for the panel was not performed. In Comparative Examples 5 and 6, since the shield electrode was formed to allow a wide width to be applied to the panel or more, it was necessary to manufacture the panel at the expense of the aperture ratio.

From the above results, in the overall evaluation, the shield electrode is patterned on the electrode as the data line and the scanning line to be 2 μm or more and 4 μm or less wider than the data line and the scanning line, and the composition obtained in this manner is evaluated as " ++ (good), when it is judged that the pattern is formed to have a width of more than 4 μm, it is necessary to evaluate the "-(inferior)" at the expense of the aperture ratio, and the pattern formed to be narrower than 2 μm is confirmed to be damaged by the electrode film. The evaluation is "- (inferior)". Confirmation by patterning the shield electrode into a ratio The width of the data line and the scanning line width of 2 μm or more and 4 μm or less can obtain good characteristics with a resolution of 150.3 ppi.

Further, in the same manner as in Example 6, after forming a shield electrode, a photoresist for a thick film is used, and patterning is performed by photolithography or the like, and a structure in which a partition wall is formed by firing is performed. The same evaluation confirmed that the same result as this time was obtained.

From the above results, it was confirmed that there was no abnormality in the evaluation of the driving of the high-resolution panel (100 ppi or more), the evaluation of the state of the electrode film, and the evaluation of the application in the electrochromic panel. Further, in the display performance, the electric field was not confirmed. Adjacent pixels have an effect, confirming that good display characteristics can be obtained with a high-resolution panel.

As explained above, according to the present invention, the following effects can be obtained. In other words, since the shield electrode is provided on the data line and the scanning line between the pixels and formed in a wide width, the electric field between adjacent pixels can be suppressed from increasing, and the color change between the pixels is small, and a clear color change can be performed.

Further, in the electrochromic method, in the present invention, since the electric field between adjacent pixels can be suppressed from being increased in a panel having a higher resolution (100 ppi or more), a high-definition panel can be displayed on a high-resolution panel.

By having such a configuration, it is possible to produce an electrochromic display medium which can easily improve the expansion of the pixel area of the electrochromic display medium and the problem of low-quality display.

[Industrial availability]

The present invention is suitable for a display device or the like of an electronic paper or the like.

Claims (7)

An electrochromic display panel comprising a data line extending in a first direction on a substrate, a scanning line extending in a second direction intersecting the data line, and an intersection region disposed between the data line and the scanning line The corresponding pixel electrode and the thin film transistor form a part of the laminated structure, and the shield electrode is covered from the data line and the scanning line, and is formed to be wider than the data line and the scanning line Width of 2 μm or more and 4 μm or less. An electrochromic display panel according to claim 1, wherein an insulating film is provided on a surface of said scanning line and said data line. The electrochromic display panel of claim 2, wherein a width of the insulating film formed on the scanning line and the data line is larger than a width of a shield electrode on the scanning line and the data line. The electrochromic display panel according to any one of claims 1 to 3, wherein the shield electrode is configured to block light on the thin film transistor. The electrochromic display panel according to any one of claims 1 to 4, wherein the thickness of the shield electrode is 150 nm or more and 400 nm or less. The electrochromic display panel according to any one of claims 1 to 5, wherein an insulating film is provided on a surface of the aforementioned shield electrode. The electrochromic display panel according to any one of claims 1 to 5, wherein a partition wall between adjacent pixels is provided on a surface of said shield electrode.