JP2012145797A - Liquid crystal panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance aperture ratios of individual pixels in a liquid crystal panel, in which a color filter layer is formed on one of two substrates interposing a liquid crystal therebetween in addition to a plurality of thin film transistors, a plurality of signal lines and a plurality of scanning lines.SOLUTION: A plurality of color material films 18 forming a color filter layer is formed on a first substrate 10. A partitioning section 32 partitioning two color material films 18 adjacent to each other is formed therebetween. A common electrode 21 extends from an upper side of one material film 18 to an upper side of another material film 18 by extending across an upper side of the partitioning section 32 therebetween.

Description

  The present invention relates to a liquid crystal panel in which a color filter layer is formed on one of two substrates sandwiching liquid crystal, in addition to a plurality of thin film transistors, a plurality of signal lines, and a plurality of scanning lines.

  The liquid crystal panel has two substrates facing each other, and liquid crystal is sealed between them. Conventionally, there is a liquid crystal panel in which a thin film transistor and a color filter layer made of three color material films are formed on one substrate (for example, Patent Document 1). In this type of liquid crystal panel, two color material films adjacent to each other are formed so that their edges overlap. The overlapping part of the two color material films is shielded by a signal line formed below it and a black matrix formed above the overlapping part.

JP 2003-50387 A

  However, in the conventional liquid crystal panel, it is necessary to widen the width of the signal line or the like in order to hide the overlapping portion of the two adjacent color material films, and this is a factor for lowering the aperture ratio of the pixel.

  The present invention has been made in view of the above problems, and an object thereof is to improve the aperture ratio of each pixel in a liquid crystal panel in which a thin film transistor and a color filter layer are formed on one substrate.

  In order to solve the above problems, a liquid crystal panel according to the present invention includes a plurality of thin film transistors, a plurality of scanning lines, a plurality of signal lines, and a plurality of pixel electrodes on one of two substrates sandwiching liquid crystal. And at least one common electrode and a plurality of color material films forming a color filter layer. Between the two adjacent color material films among the plurality of color material films, a partition portion that partitions the two color material films and shields the light is formed. The at least one common electrode is formed so as to continue from the upper side of one of the two color material films to the upper side of the other color material film beyond the partition portion. The plurality of pixel electrodes are stacked on each other via the common electrode and an insulating film, and are arranged corresponding to the plurality of color material films, respectively.

  In this invention, the partition part which divides them is formed between two adjacent color material films | membranes. For this reason, it is possible to prevent the edges of two adjacent color material films from overlapping. The common electrode continues from the upper side of one color material film to the upper side of the other color material film beyond the upper side of the partition. Therefore, the interval between the pixel electrodes formed corresponding to each color material film can be reduced. As a result, the aperture ratio of each pixel can be improved while suppressing the occurrence of color mixing due to the overlapping of two adjacent color material films.

  In the aspect of the invention, the partition portion may be formed at least above the signal line, and the width of the partition portion may be smaller than the width of the signal line. According to this aspect, the aperture ratio of the pixel can be further improved.

  In another aspect of the invention, the plurality of pixel electrodes may be formed above the common electrode. According to this aspect, the liquid crystal can be driven stably as compared with the structure in which the color material film is formed between the pixel electrode and the common electrode.

  In another aspect of the present invention, the one substrate has a spacer that defines a distance between the one substrate and the other substrate, and the spacer is formed by laminating the same material as the plurality of color material films. May be formed. According to this aspect, the material cost of the liquid crystal panel can be reduced.

It is a top view of the wiring and thin film transistor which were formed in the liquid crystal panel which concerns on one Embodiment of this invention. It is sectional drawing of the liquid crystal panel obtained by the cut surface shown by the II-II line | wire of FIG. It is sectional drawing of the liquid crystal panel obtained by the cut surface shown by the III-III line of FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of wirings and thin film transistors 2 formed on a first substrate 10 provided in a liquid crystal panel 1 which is an example of an embodiment of the present invention. FIG. 2 is a cross-sectional view of the liquid crystal panel 1 obtained by the cut surface indicated by the line II-II in FIG. FIG. 3 is a cross-sectional view of the liquid crystal panel 1 obtained at the cut surface indicated by the line III-III in FIG. In addition, in FIG. 1, the part of the partition part 32 and the shielding part 31 mentioned later is shaded.

  As shown in FIG. 2, the liquid crystal panel 1 includes a first substrate 10 and a second substrate 12 that face each other. The first substrate 10 and the second substrate 12 are, for example, transparent glass substrates. Liquid crystal 3 is sealed between the first substrate 10 and the second substrate 12.

  In the liquid crystal panel 1, both a color filter layer and a plurality of thin film transistors (hereinafter simply referred to as TFTs) 2 are formed on a first substrate 10. The liquid crystal panel 1 in this example is an IPS (In Plane Switching) type panel. Therefore, a plurality of pixel electrodes 23 to which a video signal representing a gradation value of each pixel is applied via the TFT 2 and a common electrode 21 facing the pixel electrode 23 are formed on the first substrate 10. The plurality of pixel electrodes 23 and the common electrode 21 are stacked on each other with an insulating film 24 interposed therebetween. The pixel electrode 23 and the common electrode 21 are formed of a transparent conductive film such as indium tin oxide (ITO). In the example shown in FIG. 2, a transparent conductive film 13 made of ITO is also formed on the back surface of the second substrate 12.

  As shown in FIGS. 1 and 2, a plurality of scanning lines 4 for applying a gate voltage for turning on / off the TFT 2 to the TFT 2 are formed on the first substrate 10. The plurality of scanning lines 4 are parallel to each other. As shown in FIG. 2, a gate insulating film 6 made of a transparent insulating material such as silicon oxide (SiO 2) or silicon nitride (SiN x) is formed on the scanning line 4. The scanning line 4 is covered with a gate insulating film 6.

  A plurality of signal lines 5 for supplying a video signal to the pixel electrode 23 through the TFT 2 are formed on the gate insulating film 6. The plurality of signal lines 5 are formed in parallel to each other and are orthogonal to each scanning line 4. That is, the signal lines 5 and the scanning lines 4 form a lattice shape, and an area surrounded by the two adjacent signal lines 5 and the two adjacent scanning lines 4 constitutes one pixel.

  TFT2 is provided in each pixel. As shown in FIG. 2, the TFT 2 is formed on the scanning line 4, and the scanning line 4 functions as a gate electrode of the TFT 2. The TFT 2 includes a source electrode 7 connected to the signal line 5, a semiconductor layer 9 such as amorphous silicon, and a drain electrode 8 positioned on the opposite side of the source electrode 7 across a channel portion formed by the semiconductor layer 9. have. The source electrode 7 and the drain electrode 8 are formed on the gate insulating film 6 together with the signal line 5. The semiconductor layer 9 is also formed on the gate insulating film 6 and is located above the scanning line 4. An end portion of the source electrode 7 and an end portion of the drain electrode 8 are located on the semiconductor layer 9.

  As shown in FIG. 2, the TFT 2 and the signal line 5 are covered with a protective insulating film 14 formed thereon. This protective insulating film 14 is also formed of a transparent insulating material such as SiO 2 or SiNx.

  A light shielding portion 31 is formed on the protective insulating film 14. The light shielding part 31 is formed of a material with suppressed light transmittance, such as resin black or metal chrome containing carbon. The light shielding unit 31 is located above the scanning line 4 and extends in a direction along the scanning line 4. Further, the light shielding portion 31 has a width larger than the width of the scanning line 4.

  As described above, the color filter layer is formed on the first substrate 10. The color filter layer is formed of three kinds of color material films 18 (red, green, and blue) having different colors (two adjacent color material films 18 are shown in FIG. 2). In this example, the color material film 18 is formed on the protective insulating film 14. The color material film 18 is formed of a colored resin, for example. One color material film 18 is provided for each pixel. The color material film 18 of the example described here is rectangular in plan view, and extends over almost the entire region surrounded by the two adjacent scanning lines 4 and the two adjacent signal lines 5. The three color material films 18 are arranged in a certain order in the extending direction of the scanning line 4.

  As shown in FIG. 2, a partition portion 32 is formed between two adjacent color material films 18 (specifically, two color material films 18 that are adjacent in the extending direction of the scanning line 4 and have different colors). Has been. The partition portion 32 partitions these two color material films 18. Therefore, the edges of the two adjacent color material films 18 do not have overlapping portions. The partition portion 32 is located in the same layer as the color material film 18. In this example, the partition portion 32 is formed on the protective insulating film 14 together with the color material film 18. In the example shown in FIG. 2, the thickness of the partition portion 32 and the thickness of the color material film 18 are defined so that the heights of the upper surfaces thereof are aligned.

  The partition part 32 is formed above the signal line 5 described above. The partition 32 extends in the direction along the signal line 5. As shown in FIG. 2, the partition part 32 has a width smaller than the width of the signal line 5. Therefore, the entire partition portion 32 is located above the signal line 5.

  The partition part 32 is formed of a material whose light transmittance is suppressed, such as resin black containing carbon or metal chrome, and has a light shielding function, like the light shielding part 31 described above. In other words, the partition 32 blocks light that tries to pass between the two adjacent color material films 18. As shown in FIG. 1, the light shielding portion 31 extends in a direction along the scanning line 4. Further, the partition portion 32 extends in a direction along the signal line 5. The partition part 32 and the light-shielding part 31 are orthogonal to each other and form a black matrix having a lattice shape as a whole.

  As shown in FIG. 2, a common electrode 21 is formed on the color material film 18. The common electrode 21 is formed across the plurality of color material films 18. That is, when attention is paid to two adjacent color material films 18, the common electrode 21 extends from the upper side of one color material film 18 to the upper side of the other color material film 18 beyond the upper side of the partition portion 32. In this example, the common electrode 21 is formed on the color material film 18 and the partition portion 32. As described above, the three color material films 18 are arranged in the extending direction of the scanning lines 4 in a certain order. The common electrode 21 extends on the color material film 18 in the alignment direction of the color material film 18 and covers the plurality of color material films 18 and the plurality of partition portions 32. In particular, in this example, a film-like common electrode 21 is formed in the entire region except for a contact hole 26 described later. Therefore, all the color material films 18 and all the partition portions 32 are covered by one common electrode 21.

  Further, by forming the common electrode 21 in this way, the signal line 5 formed below the partition portion 32 is also covered with the common electrode 21. Therefore, the occurrence of an electric field in the liquid crystal 3 due to the video signal flowing through the signal line 5 is suppressed. The common electrode 21 is also formed on the light shielding portion 31. Thereby, the occurrence of an electric field in the liquid crystal 3 due to the signal applied to the scanning line 4 is suppressed.

  On the common electrode 21, an insulating interlayer film (insulating film in claims) 24 covering the common electrode 21 is formed. The pixel electrode 23 is disposed corresponding to each color material film 18. In this example, the plurality of pixel electrodes 23 are formed on the interlayer film 24. The plurality of pixel electrodes 23 are positioned above the plurality of color material films 18 and respectively face the plurality of color material films 18. The plurality of pixel electrodes 23 arranged in the extending direction of the scanning line 4 face each other with the interlayer film 24 sandwiched between one common electrode 21. The pixel electrode 23 has a plurality of slits.

  In the present embodiment, the edges of two adjacent color material films 18 do not have overlapping portions, and the common electrode 21 is continuously formed from one color material film 18 to the other color material film 18. Therefore, the distance D (see FIG. 1) between two adjacent pixel electrodes 23 can be reduced.

  As shown in FIG. 2, the pixel electrode 23 is connected to the drain electrode 8 through a contact hole 26. The drain electrode 8 of this example extends beyond the scanning line 4 and the light shielding portion 31 toward the inside of each pixel (toward the color material film 18). The contact hole 26 is located between the color material film 18 and the light shielding portion 31 and penetrates the interlayer film 24 and the protective insulating film 14. The end of the drain electrode 8 is located at the lower end of the contact hole 26. The pixel electrode 23 extends inside the contact hole 26, and the end of the drain electrode 8 is connected to the pixel electrode 23 through the contact hole 26.

  As shown in FIG. 3, the first substrate 10 is formed with a plurality of spacers 35 that define the distance between the first substrate 10 and the second substrate 12. In this example, the spacer 35 is located above the scanning line 4. The spacer 35 is formed by three color material films 19 made of the same material as the three color material films 18 forming the color filter layer. That is, the spacer 35 is formed by laminating three color material films 19 having different colors. The lowermost color material film 19 is formed on the light shielding portion 31. Two color material films 19 are laminated on the lowermost color material film 19. The three color material films 19 are formed so that their areas become smaller as they go upward. The three color material films 19 are covered with an interlayer film 24, and a spacer 35 is formed by the three layers of the color material film 19 and the interlayer film 24. Thus, since the spacer 35 is formed on the light-shielding part 31, it can prevent that the spacer 35 becomes a factor of the fall of the aperture ratio of each pixel.

  The color material film 19 can be formed in the same process as the process of forming the color material film 18. That is, in the process of forming the first color material film 18 among the three kinds of color material films 18, the lowermost color material film 19 is formed on the light shielding portion 31. Then, in the step of forming the second color material film 18, the middle color material film 19 is formed on the lowest color material film 19. In the process of forming the last color material film 18, the uppermost color material film 19 is formed on the middle color material film 19.

  As described above, in the liquid crystal panel 1, the partition portion 32 that divides them is formed between the two adjacent color material films 18. For this reason, it is possible to prevent the edges of two adjacent color material films 18 from overlapping. The common electrode 21 extends from the upper side of one color material film 18 to the upper side of the other color material film 18 beyond the upper side of the partition portion 32. Therefore, the interval between the pixel electrodes 23 formed corresponding to each color material film 18 can be reduced. Therefore, the aperture ratio of each pixel can be improved while suppressing the occurrence of color mixing due to the overlapping of two adjacent color material films 18.

  The present invention is not limited to the liquid crystal panel 1 described above, and various modifications can be made. For example, in the liquid crystal panel 1, the width of the partition portion 32 is smaller than the width of the signal line 5. However, the width of the partition portion 32 is not necessarily limited to this, and may be larger than the width of the signal line 5.

  Further, the first substrate 10 was provided with a spacer 35 made of the color material film 19. However, the first substrate 10 is not necessarily provided with such a spacer 35. A separate spacer may be disposed between the first substrate 10 and the second substrate 12.

  In the above description, the plurality of pixel electrodes 23 are formed above the common electrode 21. However, the plurality of pixel electrodes 23 may be formed below the common electrode 21. For example, a plurality of pixel electrodes 23 may be formed on the plurality of color material films 18, and an interlayer film that is an insulating film may be formed on the plurality of pixel electrodes 23. A common electrode 21 may be formed on the interlayer film.

  DESCRIPTION OF SYMBOLS 1 Liquid crystal panel, 2 Thin film transistor (TFT), 3 Liquid crystal, 4 Scan line, 5 Signal line, 6 Gate insulating film, 7 Source electrode, 8 Drain electrode, 9 Semiconductor layer, 10 1st board | substrate, 12 2nd board | substrate, 13 transparent conductive film, 14 protective insulating film, 18 color material film, 19 color material film, 21 common electrode, 23 pixel electrode, 24 interlayer film, 26 contact hole, 31 light shielding part, 32 partition part, 35 spacer.

Claims (4)

In a liquid crystal panel having two substrates sandwiching liquid crystal,
One of the two substrates includes a plurality of thin film transistors, a plurality of scanning lines, a plurality of signal lines, a plurality of pixel electrodes, at least one common electrode, and a plurality of colors forming a color filter layer. A material film,
Between the two color material films adjacent to each other among the plurality of color material films, a partition portion that partitions the two color material films and shields light is formed.
The at least one common electrode is formed so as to continue from the upper side of one of the two color material films to the upper side of the other color material film beyond the partition portion,
The plurality of pixel electrodes are stacked on each other via the at least one common electrode and an insulating film, and are disposed corresponding to the plurality of color material films, respectively.
A liquid crystal panel characterized by that. The liquid crystal panel according to claim 1,
The partition is formed at least above the signal line,
The width of the partition is smaller than the width of the signal line,
A liquid crystal panel characterized by that. The liquid crystal panel according to claim 1,
The plurality of pixel electrodes are formed above the at least one common electrode.
A liquid crystal panel characterized by that. The liquid crystal panel according to claim 1,
The one substrate has a spacer that defines a distance between the one substrate and the other substrate;
The spacer is formed by laminating the same material as the plurality of color material films.
A liquid crystal panel characterized by that.

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