JP2005300744A - Liquid crystal display element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the simple manufacturing method of a liquid crystal display element having satisfactory display quality. <P>SOLUTION: First and second conductive films are formed on first and second substrates, respectively. First and second electrode pattern data in facing regions including display units and data of mutually relatively aligned first and second slit patterns are superposed on each other respectively to prepare first and second reticles so that the slit patterns formed at respective substrates are alternately disposed in a slit width direction when completed substrates are disposed opposite to each other and viewed from the normal direction of the substrates. The first and the second reticles are transferred to form first and second masks of electrode patterns including the slit patterns on the first and the second conductive films, respectively and etching is performed to form first and second transparent electrodes. First and second alignment layers are formed on the first and second substrates so as to cover the first and the second transparent electrodes. The first and the second substrates are disposed opposite to each other to be nearly parallel and is made to adhere to each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a liquid crystal display element that aligns liquid crystal with an oblique electric field, and a method for manufacturing the same.

  FIG. 12 is a cross-sectional view showing a conventional example of a vertical alignment type liquid crystal display element (Liquid Crystal Display). The vertical alignment LCD 50 is formed of a pair of substrates (an upper substrate 32 and a lower substrate 31) and a liquid crystal layer 39 sandwiched therebetween, for example, a nematic liquid crystal 39a having a negative dielectric anisotropy (Δε <0). And a nematic liquid crystal layer. Each of the upper substrate 32 and the lower substrate 31 is formed of a transparent conductive material such as ITO (Indium Tin Oxide) on the transparent substrates 34 and 33, which are flat glass substrates, for example, and a predetermined glass substrate. It includes transparent electrodes 36 and 35 having patterns, and vertical alignment films 38 and 37 formed on the transparent electrodes 36 and 35.

  The pair of substrates (the upper substrate 32 and the lower substrate 31) are arranged in parallel so that the vertical alignment films 38 and 37 face each other, and a liquid crystal layer 39 is sandwiched between the vertical alignment films 38 and 37. A voltage application unit 43 is connected between the transparent electrodes 36 and 35, and an arbitrary voltage can be applied to the liquid crystal layer 39 between the transparent electrodes 36 and 35 by the voltage application unit 43. The vertical alignment films 38 and 37 are subjected to an alignment process such as provision of a pretilt angle. By the alignment treatment, the liquid crystal molecules of the liquid crystal layer 39 in contact with the vertical alignment films 38 and 37 are aligned in a direction substantially perpendicular to the substrates (upper substrate 32 and lower substrate 31) and inclined by a pretilt angle. When a voltage is applied to the liquid crystal layer 39, the pretilt angle defines the direction in which the liquid crystal molecules fall.

  On the outside of the pair of substrates (the upper substrate 32 and the lower substrate 31), a pair of polarizing plates 41 and 42 are disposed, for example, in a crossed Nicols state. As shown in the figure, when defining the X, Y, and Z directions orthogonal to each other, the polarizing plate 41 facing the upper substrate 32 transmits, for example, only light polarized in the X direction and facing the lower substrate 31. For example, 42 is arranged to transmit only light polarized in the Y direction. Further, the pair of substrates (the upper substrate 32 and the lower substrate 31) sandwiching the liquid crystal layer 39 has the normal direction of each substrate (the upper substrate 32 and the lower substrate 31) parallel to the Z direction, and When viewed from the normal direction (Z direction) of the upper substrate 32 or the lower substrate 31, the liquid crystal molecules at the time of voltage application are arranged so as to fall in a direction that forms 45 ° with the X direction and the Y direction.

  In the vertical alignment LCD 50, a viewing angle compensation film 40 is inserted between the upper substrate 32 and the polarizing plate 41 in order to improve the viewing angle dependency. As the viewing angle compensation film 40, for example, a uniaxial optical film having an optical axis in the normal direction of the film and a negative birefringence is used. The viewing angle compensation film 40 can be disposed only on one substrate side as shown in the figure, or can be disposed outside both substrates. The retardation of the viewing angle compensation film 40 is about 1 to 3 times that of the liquid crystal layer 39. When the viewing angle compensation film 40 is disposed on both the substrate sides, the sum of the retardations of the two viewing angle compensation films 40 is 1 to 3 times that of the liquid crystal layer 39.

  The vertical alignment type LCD 50 having the structure shown in FIG. 12 has a drawback that the viewing angle characteristics from the direction in which the liquid crystal molecules are tilted are extremely deteriorated.

A pair of transparent electrodes formed on the upper and lower substrates is formed in a shape having slits, and the twisted nematic (Twisted), wherein the slits of one transparent electrode and the slits of the other transparent electrode are alternately arranged in the display region (Nematic, TN) liquid crystal display elements have been proposed. (For example, see Patent Document 1.)
According to this proposal, an oblique electric field is generated in the slit portion, and the direction in which the oblique electric field is inclined is reversed on both sides of the slit. In the display area of a pair of electrodes, when a voltage is applied, small areas with the opposite directions of the rising direction of the liquid crystal molecules are formed simultaneously, so that the viewing angle dependence of each small area is complemented, and the viewing area dependence of the entire display area Is reduced, visibility is improved from any direction, and display quality is improved.

Japanese Patent No. 3108768

  An object of the present invention is to provide a liquid crystal display element with good display quality and a simple manufacturing method thereof.

  According to one aspect of the present invention, there is provided a method for manufacturing a liquid crystal display element that performs display in a display region including at least one display unit, wherein (a) a first transparent conductive material film is formed on a first substrate. (B) forming a second transparent conductive material film on the second substrate; and (c) data of a region including at least a part of the display region, the region The first and second electrode pattern data of the opposing region including at least one display unit inside and the data of the first and second slit patterns that are relatively aligned with each other are overlaid and completed. The first and second reticles in which the slit patterns formed on each substrate are alternately arranged in the width direction of the slit when the substrates are arranged facing each other and viewed from the normal direction of the substrate And (d) the first and first And (e) forming the first and second masks of the electrode pattern including the slit pattern on the first and second transparent conductive material films, respectively. Etching the first transparent conductive material film on which the mask is formed to form a first transparent electrode including the first slit pattern on the first substrate; and (f) the second. Etching the second transparent conductive material film on which the mask is formed to form a second transparent electrode including the second slit pattern on the second substrate; and (g) the first Forming first and second alignment films on the first and second substrates, respectively, so as to cover the first and second transparent electrodes; and (h) the first and second substrates, The first and second alignment films face each other and are arranged substantially parallel to each other. Method of manufacturing a liquid crystal display device and a step of wearing is provided.

  According to this method for manufacturing a liquid crystal display element, a liquid crystal display element having a multi-domain structure and good display quality can be easily manufactured.

  According to another aspect of the present invention, a first substrate and a plurality of first slit-shaped openings formed on one surface of the first substrate and distributed two-dimensionally are provided. A first transparent electrode, a first alignment film formed on one surface of the first substrate so as to cover the first transparent electrode, and a substantially parallel arrangement with the first substrate. A second substrate and a second transparent electrode formed on a surface of the second substrate facing the first substrate and viewed from a normal direction of the first and second substrates; A second region having a plurality of second slit-like openings distributed in a two-dimensional manner that overlap with each other to define a region including a display unit and are alternately arranged in the width direction with the first slit-like openings. A transparent electrode and a surface of the second substrate facing the first substrate are formed so as to cover the second transparent electrode. A second alignment film, and when viewed from the normal direction of the first and second substrates, an outer periphery of the display unit, and the first and second slit-shaped openings or their extensions, Thus, a liquid crystal display element is provided in which the number of intersections between the slit and the outer periphery is greater than the number of extensions of the slit and the outer intersection.

  This liquid crystal display element is a liquid crystal display element having a good display quality and having a multi-domain structure.

  ADVANTAGE OF THE INVENTION According to this invention, a liquid crystal display element with favorable display quality and its simple manufacturing method can be provided.

  FIG. 1A is a schematic plan view showing a display area of a liquid crystal display element. FIGS. 1B and 1C are respectively a common electrode (transparent electrode 36 of the upper substrate 32) and a segment electrode ( It is a schematic plan view of the transparent electrode 35) of the lower substrate 31.

  Reference is made to FIG. The display area refers to an area in the liquid crystal display element that displays characters, figures, and the like. In FIG. 1A, the rectangular area within the dotted line is the display area 70. The display area 70 is demarcated inside by a closed curve (contour line, outer peripheral line), and a display unit 71 which is a part that is actually displayed by a change in the alignment state of the liquid crystal, and a ground part at the time of display. And other parts that function as well. In this specification, the display area 70 and the display unit 71 are defined as described above.

  Reference is made to FIGS. 1B and 1C. When viewed from the normal direction of the upper substrate 32 and the lower substrate 31, the pair of transparent electrodes 35 and 36 overlap to define a region including the display unit 71.

  A partial outline of the previous proposal made by the applicant (Japanese Patent Application No. 2003-044662) will be described with reference to FIGS.

  FIG. 2 is a cross-sectional view schematically showing a vertical alignment type liquid crystal display device according to the previous proposal. 12 is different from the liquid crystal display element according to the conventional example shown in FIG. 12 in the structure of the transparent electrodes 35 and 36 and in that the arrangement thereof is devised. Another difference is that the vertical alignment films 37 and 38 are applied and cured vertical alignment films that are not subjected to special alignment processing such as rubbing.

  As will be described in detail later, in the transparent electrodes 35 and 36, a plurality of substantially rectangular slits 35a and 36a are regularly formed in a two-dimensional plane, for example, in a region within the display unit 71. When viewed from the normal direction of the upper substrate 32 and the lower substrate 31, the two transparent electrodes 35 and 36 include a slit 35 a provided in one transparent electrode 35 and a slit 36 a provided in the other transparent electrode 36. Are alternately arranged in a direction (width direction, short direction, left-right direction in FIG. 2) orthogonal to the length direction (longitudinal direction, direction perpendicular to the paper surface of FIG. 2) of the slits 35a, 36a. Yes.

  3A to 3D are views for explaining the arrangement of the slits 35a and 36a in the display unit 71 of the liquid crystal display element. 3A is a plan view, FIG. 3B is a cross-sectional view, FIG. 3C is a perspective view, and FIG. 3D is a partial plan view.

  Reference is made to FIG. FIG. 3A shows an example of the display unit 71 of the vertical alignment type liquid crystal display element of a simple segment type. Shown is a display unit 71 representing the number “1”. As described above, for example, the slits 35a and 36a are formed in the transparent electrodes 35 and 36 in the inner region (display unit 71) surrounded by the outline of the character “1”.

  When viewed from the normal direction of the substrate, the transparent electrode 36 of the upper substrate 32 is formed with a substantially rectangular slit 36a (36a1, 36a2, 36a3,..., 36an), and the transparent electrode 35 of the lower substrate 31 is formed. Are formed with slits 35a (35a1, 35a2, 35a3,..., 35an). For example, each slit-like opening (slit 35a and slit 36a) of both transparent electrodes 35 and 36 is congruent. The slits 35a, 36a of both electrodes 35, 36 are formed in the same two-dimensional in-plane direction (length direction and width direction) with the same pitch.

  The slit 35a (35a1, 35a2, 35a3,..., 35an) and the slit 36a (36a1, 36a2, 36a3,..., 36an) are the width direction of the slit (the vertical direction in FIG. 3A). Are arranged and arranged alternately. In addition, the slits 35a and 36a of the two transparent electrodes 35 and 36 are formed so that the slit edge in the length direction (edge of the opening) is aligned along the width direction of the slit (vertical direction in FIG. 3A). Placed.

  In order to bring the display characteristics closer to each other, it is desirable that the interval in the width direction between the slits 35a and 36a arranged alternately is substantially constant.

  FIG. 3B is a cross-sectional view taken along line 3B-3B in FIG. The substantially rectangular slits 35a, 36a provided in the two transparent electrodes 35, 36 are alternately arranged in a direction (width direction) orthogonal to the length direction (left-right direction in FIG. 3A).

  FIG. 3C is a perspective view of the display unit 71 shown in FIG. The slits 35a and 36a are formed in portions of the transparent electrodes 35 and 36 located within the display unit 71.

  FIG. 3D is a plan view showing a part of the display unit 71 shown in FIG. The slits 35a and 36a are formed in a substantially rectangular shape having a length direction of 40 μm and a width direction of 20 μm, for example. The slit interval in the length direction on one transparent electrode is 20 μm, and the slit interval in the width direction is 100 μm. In this case, the slits 35a and 36a are formed at a constant pitch of 60 μm in the length direction and 120 μm in the width direction. When viewed from the normal direction of the substrate, the slit interval in the width direction of the transparent electrodes 35a and 36a of different substrates is 40 μm.

  4A and 4B are cross-sectional views for explaining the operation and effect of the previously proposed liquid crystal display element.

  Reference is made to FIG. FIG. 4A shows a cross section orthogonal to the length direction of the slits 35a and 36a (the direction perpendicular to the paper surface of FIG. 2).

  When a voltage is applied between the two transparent electrodes 35 and 36, an oblique electric field 4 (an electric field in which the direction of the electric field is tilted from the normal direction of the substrate) is generated near the edges of the slits 35a and 36a. When viewed from the normal direction of the substrate (vertical direction in FIG. 4A), the slits 35a and 36a are alternately arranged in the width direction (horizontal direction of FIG. 4A) with the liquid crystal layer 39 interposed therebetween. Therefore, the direction of the oblique electric field 4 generated at the edge of each slit formed in one transparent electrode is the same direction (direction parallel to each other) on a certain side of the slit. For example, in FIG. 4A, the direction of the oblique electric field 4 generated at the right end of the slit 35a of the transparent electrode 35 is the same direction (substantially parallel direction), and the direction of the oblique electric field 4 generated at the left end. Are also in the same direction (substantially parallel directions). The directions of the oblique electric fields 4 generated at both ends of one slit 35a are different from each other (reverse directions).

  As a result, two small regions α and β having different directions of the generated electric field are defined in the transparent electrode 36 between the adjacent slits 36a. In addition, two small regions γ and δ having different electric field directions are also defined in a portion of the transparent electrode 36 adjacent to the small regions α and β across one slit 36a. The direction of the electric field in the small region α and the small region γ is the same direction, and the direction of the electric field in the small region β and the small region δ is the same direction.

  By generating the electric field in this way, the direction in which the liquid crystal molecules fall can be controlled.

  Reference is made to FIG. FIG. 4B is a schematic cross-sectional view showing the direction in which the liquid crystal molecules 39 a are tilted by the oblique electric field 4. The liquid crystal molecules 39a are tilted in different directions (reverse directions) by the oblique electric fields 4 in different directions generated at both ends of one slit 36a.

  Therefore, in the small region α and the small region β in FIG. 4A, the direction in which the liquid crystal molecules 39a are tilted is different, and the same applies to the small region γ and the small region δ. In the small region α and the small region γ, and in the small region β and the small region δ, the liquid crystal molecules 39a are tilted in the same direction. Therefore, a two-domain alignment structure can be realized.

  FIG. 5 is a plan view showing a part of the display area 70 of the simple matrix type dot matrix type liquid crystal display element. The transparent electrode 36 (common electrode) of the upper substrate 32 and the transparent electrode 35 (segment electrode) of the lower substrate 31 are both formed in a rod shape, for example, and both rod-shaped electrodes are substrates (upper substrate 32 and lower substrate 31). When viewed from the normal line direction, they are arranged to cross each other, for example, to be orthogonal to each other. A region where the rod-shaped electrodes intersect corresponds to the display unit 71. The slit-shaped opening (slit 35a) of the transparent electrode 35 (segment electrode) and the slit-shaped opening (slit 36a) of the transparent electrode 36 (common electrode) are formed in, for example, a congruent substantially rectangular shape. In addition, the slit-shaped openings of both electrodes are formed in the length direction and the width direction at the same pitch. The rod-shaped transparent electrode 36 (common electrode) is formed with slits 36a so that the extending direction thereof is parallel to the width direction of the slits 36a. In the rod-shaped transparent electrode 35 (segment electrode), a slit 35a is formed so that the extending direction thereof is parallel to the length direction of the slit 35a. The slits 35a, 36a of both the electrodes 35, 36 are formed and arranged so as to be alternately arranged in the extending direction of, for example, the rod-like transparent electrode 36 (common electrode) when viewed from the normal direction of the substrate. Further, for example, the slits 35a and 36a of the two transparent electrodes 35 and 36 are arranged so that the slit edges (edges of the opening) in the length direction are aligned along the width direction of the slits.

  In the case of the dot matrix type liquid crystal display element in which the transparent electrodes 35 and 36 are formed and arranged in this manner in the display region 70, the same effect as described with reference to FIGS. An effect can be obtained.

  FIG. 6 is a schematic plan view showing several pixels of a TFT active matrix liquid crystal display element which is another example of the dot matrix type. For example, a plurality of TFT elements 20 made of amorphous silicon and a transparent electrode 35 (pixel electrode) made of ITO are formed on one transparent glass substrate. Further, a source line (signal line) 22 and a gate line (scanning line) 23 respectively connected to the source electrode S and the gate electrode G of the TFT element 20 are formed, and a transparent electrode is formed by the TFT element 20 via the drain electrode D. A drive signal is transmitted to 35 (pixel electrode). A common transparent electrode 36 (common electrode) made of ITO is formed on the other opposing transparent glass substrate.

  Similar to the slits of the display unit 71 shown in FIG. 3A, the opposing transparent electrodes 35 and 36 have substantially rectangular slits 35a and 36a in the width direction of the slit when viewed from the normal direction of the substrate. Are arranged and arranged alternately. Except for this point, the formation and arrangement of the slits 35a and 36a are the same as those described with reference to FIG.

  In the case of the TFT active matrix liquid crystal display element in which the slits 35a and 36a are formed and arranged as described above, the same effects as those described with reference to FIGS. 4A and 4B can be obtained.

  The applicant has proposed the liquid crystal display element as described above in the previous application (Japanese Patent Application No. 2003-044262).

  Hereinafter, as an embodiment of the present invention, a method for manufacturing a liquid crystal display element according to the above proposal will be described. In the previous proposal, the manufacturing method of the liquid crystal display element has not been sufficiently disclosed, and therefore will be described together with examples of the present invention.

  7A to 7E are schematic diagrams for explaining an example of a method for manufacturing a simple segment type vertically aligned liquid crystal display element having the display unit 71 shown in FIGS. 3A to 3D. It is.

  Reference is made to FIG. For example, a transparent conductive material film made of ITO, for example, is formed on the transparent substrate 33 which is a transparent glass substrate, for example, by sputtering.

  Reference is made to FIG. A mask 90 having a predetermined pattern is formed on the ITO film, and etching is performed. The mask 90 has a slit pattern in a part thereof. The mask 90 and a manufacturing method thereof will be described in detail later.

  Reference is made to FIG. By patterning into a predetermined shape by etching, the transparent electrode 35 including the slit 35a to which the mask 90 is transferred is formed on the transparent substrate 33. The slit 35a is formed only inside the display unit 71 of the liquid crystal display element, for example. A vertical alignment film 37, for example, SE-1211 manufactured by Nissan Chemical Industries, is applied and cured to a thickness of 500 mm so as to cover the transparent electrode 35 on the transparent substrate 33, whereby the lower substrate 31 is obtained. The vertical alignment film 37 aligns liquid crystal molecules on average approximately perpendicular to the surface. The vertical alignment film desirably has a surface free energy of 35 N / m to 39 N / m.

  Reference is made to FIG. The upper substrate 32 is obtained by a process similar to the process described with reference to FIGS. The upper substrate 32 includes a transparent substrate 34, a transparent electrode 36 having a slit 36 a formed on the transparent substrate 34, and a vertical alignment film 38 coated and cured on the transparent substrate 34 and the transparent electrode 36. The vertical alignment film 38 also has a thickness of 500 mm, for example, and aligns liquid crystal molecules substantially perpendicularly to the surface on average. The mask used when forming the transparent electrode 36 of the upper substrate 32 also has a slit pattern in a part thereof. This point will also be described in detail later.

  Reference is made to FIG. The upper substrate 32 and the lower substrate 31 are bonded to each other with the surfaces on which the vertical alignment films 37 and 38 are formed facing each other substantially in parallel.

  When viewed from the normal direction of the upper substrate 32 and the lower substrate 31, the plurality of slits 35 a of the transparent electrode 35 and the plurality of slits 36 a of the transparent electrode 36 are alternately arranged in the slit width direction. In other respects, the slits 35a and 36a are arranged as described with reference to FIGS. Not only the slit edges in the length direction of the substantially rectangular slits 35a and 36a are aligned along the width direction of the slit, but also the slits 35a and 36a adjacent in the width direction are arranged in the length direction as described later. Alternatively, it may be shifted by a half pitch. The reticle is manufactured so that the above arrangement is realized. The fabrication of the reticle will be described later.

  For adhesion, for example, a UV curable main sealant is applied to the periphery of the cell, a 4 μm diameter gap control agent (for example, silica beads manufactured by Catalyst Chemical Industries, Ltd.) is sprayed, and then superimposed and irradiated with UV to cure the main sealant. To do. An empty cell is thus produced.

  The empty cells are cut in units of cells, and a liquid crystal layer 39 is formed by injecting, for example, a liquid crystal 39a having a birefringence of 0.15 manufactured by Merck by a vacuum injection method. The inlet is sealed to complete the liquid crystal cell. A viewing angle compensation film 40, for example, a VAC-C180 film manufactured by Sumitomo Chemical Co., Ltd., is arranged substantially in parallel on the upper substrate 32 of the liquid crystal cell, and a polarizing plate 41 is arranged substantially in parallel on the viewing angle compensation film 40. Further, the polarizing plate 42 is arranged substantially in parallel on the lower substrate 31. For example, both polarizing plates 41 and 42 are arranged in a crossed Nicols state.

  Through the steps as described above, the liquid crystal display device as shown in FIG. 2 is manufactured.

  A mask for forming the slits 35a and 36a in the transparent electrodes 35 and 36 will be described.

  The mask can be designed using CAD. The mask is designed so that the slits 35a and 36a are arranged with high symmetry in each display unit 71. In FIG. 3A, for the contour portion (for example, a vertical bar portion of “1”) of the display unit 71 “1”, the contour line and the end portions of the slits 35a and 36a adjacent to the contour line. The slits 35a and 36a are formed so that the distance between them is equal on the left and right. On CAD, a mask corresponding to this slit arrangement is designed. In addition, in order to arrange the slits with high symmetry, the slits are designed for each different display unit 71. Further, in different display units 71, slits having different sizes may be formed.

  Forming the slits 35a and 36a with high symmetry in the display unit 71 contributes to suppression of a certain kind of deterioration in display quality (for example, the outline of the display unit 71 appears to be emphasized).

  However, when performing a segment display other than the 7-segment display, on the CAD, a slit is formed with high symmetry for each display unit 71 having a different shape (for example, “1”, “2”, etc.). The method of designing a mask cannot be said to have high work efficiency.

  In the case where a 7-segment display electrode, a dot matrix display electrode as shown in FIG. 5 and an active matrix display electrode as shown in FIG. 6 are produced, the segment display other than the 7-segment display electrode is also performed by the above method. The working efficiency is not as bad as when an electrode is produced. This is because the 7-segment display electrode is formed by repeating a predetermined electrode pattern. In the case of a dot matrix display electrode or an active matrix display electrode, a large number of pixels having a predetermined shape are arranged on one screen, so even if the slits are arranged with high symmetry on the display electrode, This is because the design is performed on the pixels and it is repeated for all the pixels.

  In order to increase the working efficiency, a mask manufacturing method as described below is effective.

  FIGS. 8A and 8B are diagrams showing an outline of a slit pattern used when manufacturing a mask. FIG. 8A shows a slit pattern used at the time of manufacturing a mask for forming the slit 35a in the transparent electrode 35 (segment electrode) of the lower substrate 31, and FIG. The slit pattern used at the time of mask production for forming the slit 36a in the transparent electrode 36 (common electrode) is shown.

  In both of the slit patterns shown in the drawings, substantially rectangular slits having a length direction of 100 μm and a width direction of 20 μm are formed at regular intervals in the length direction and the width direction (20 μm intervals in the length direction and 100 μm intervals in the width direction). ing. For this reason, these slit patterns are slit patterns in which substantially rectangular slits are formed at a constant pitch of 120 μm in the length direction and 120 μm in the width direction. In addition, the size of the slit and the space | interval between slits in the slit pattern shown to FIG. 8 (A) and (B) were made the same as those in the slit formed in a mask.

  In both figures, the center line is two orthogonal straight lines. When the center lines in FIGS. 8A and 8B are overlapped, the slit edges (openings) in the length direction are arranged so that the slits in both figures are alternately arranged at equal intervals in the width direction of the substantially rectangular slit, for example. The center lines in both figures are defined so that the edges of the portions are aligned along the width direction of the slit.

  FIGS. 9A and 9B are schematic views for explaining a part of a process for manufacturing a mask, and FIGS. 9C and 9D are schematic plan views showing the manufactured mask. FIG.

  Reference is made to FIG. Data of an area including at least a part of the display area 70 of the liquid crystal display element, and data of an opposing area including at least one display unit 71 in the area (data of electrode patterns of segment electrodes and common electrodes) On the other hand, for example, a slit arrangement is assumed with a certain repetitive pattern. For example, consider a slit arrangement in which the slit patterns shown in FIGS. 8A and 8B are aligned with respect to the center line and overlapped.

  Reference is made to FIG. For example, a slit pattern is provided only in a portion where the temporarily arranged slit pattern and the display unit 71 overlap, and an electrode pattern reticle including the slit pattern is produced on, for example, a quartz substrate. A slit corresponding to each slit pattern using a slit pattern indicated by a solid line (slit pattern shown in FIG. 8B) and a slit pattern indicated by a dotted line (slit pattern shown in FIG. 8A), respectively. A reticle on two quartz substrates having Next, for example, a photoresist layer is laminated on the ITO film on the transparent substrates 33 and 34, and the reticles on the two quartz substrates are reduced and transferred to the photoresist layers, respectively. A mask corresponding to the reticle on the quartz substrate is formed on the ITO film. Transparent electrodes 35 and 36 having slits 35a and 36a are formed by these masks.

  9A and 9B, for the convenience of explanation, only the data of the display unit 71 portion of the electrode patterns of the segment electrode and the common electrode is shown.

  In the production of the reticle, the operation corresponding to the above steps is not performed on the CAD, but the electrode pattern data and the slit pattern of the area including the display unit 71 in the display area 70 are produced at the stage of producing the reticle. Overlay data and draw.

  When the mask is manufactured as described above, for example, it is not necessary to individually design a slit for each of the segment display units 71, and a liquid crystal display element can be manufactured easily and with high work efficiency. .

  FIG. 9C shows a mask for manufacturing a common electrode, and FIG. 9D shows a mask for manufacturing a segment electrode. By superimposing the electrode pattern data and the slit pattern data to form a slit-shaped opening, a mask having an outline according to the electrode pattern data and a slit-shaped opening according to the slit pattern data can be produced. Since the common electrode and the segment electrode are produced by transferring these masks, they have substantially the same shape as these masks. In FIG. 9C, a portion corresponding to the display unit 71 is indicated by a one-dot chain line for use as a reference convenience.

  FIG. 10 is a photomicrograph obtained by photographing the display unit 71 of the solid-state imaging device in which the transparent electrodes 35 and 36 are formed using the mask by using the above-described steps and from the normal direction of the substrate. is there. A part of the vertical bar portion of the display unit 71 representing the character “T” was photographed.

  The transparent electrodes 35 and 36 appear whitish, and the slits 35a and 36a appear in a black horizontally long (long in the left-right direction in the figure) rectangle. When the center line of the vertical bar portion is defined in the vertical direction, it can be seen that the symmetry of the slits 35a and 36a arranged in the display unit 71 is broken with respect to the center line. Further, for example, in the vertical bar portion of the display unit 71 representing the character “1” shown in FIG. 3A, the contour line and the edges of the openings (slits 35a, 36a) of the transparent electrodes 35, 36 intersect. In contrast, in the photograph shown in FIG. 10, the two intersect.

  When the slits 35a and 36a are provided in the transparent electrodes 35 and 36 in the display unit 71 using the mask manufactured as described above, the slits 35a of the transparent electrodes 35 and 36 in the display unit 71 are excluded except in rare cases. , 36a will be broken. Further, the outer peripheral line of the display unit 71 and the edges of the slits 35a and 36a will intersect. Further, when viewed from the normal direction of the substrate, in many cases, the outer peripheral line of a certain display unit 71 and the intersection of the slit-like openings (slits 35a and 36a) of the transparent electrodes 35 and 36, and the outer peripheral line and the slit. The number of the former will be greater than the number of the latter with respect to the intersection with the extension when the elongated opening is extended in the longitudinal direction.

  Although the slits 35a and 36a appear to be connected in the horizontal direction in the figure with black lines, the black lines that are visible between the slits are disclination lines in which an alignment mismatch surface appears. The disclination line is generated at the boundary where the tilt direction of the response of the liquid crystal is switched, for example.

  When the display of the liquid crystal display element showing a part of the display unit 71 in FIG. 10 is observed, it is confirmed that there is no defect such as emphasis on the contour with a biased edge portion and a display with good display characteristics can be obtained. It was done. That is, the liquid crystal display element using the transparent electrodes 35 and 36 in which the slits 35a and 36a are formed with the mask manufactured using the mask manufacturing method described with reference to FIGS. It was found to have characteristics.

  9A and 9B, the segment display type liquid crystal display element other than the 7 segment display type has been described as an example, but the 7 segment display type liquid crystal display element, the dot matrix display type liquid crystal display element, The present invention can also be applied to the production of an active matrix type liquid crystal display element.

  FIG. 11 is a schematic plan view showing a part of the display unit 71 of the liquid crystal display element. The other example of arrangement | positioning of the slit of the transparent electrode seen from the normal line direction of the board | substrate was shown. 3D shows the liquid crystal display element in which the edges in the length direction of the slit are aligned along the width direction. In the liquid crystal display element shown in FIG. The edges of the 36 slits 35a, 36a are not aligned. Slits adjacent in the width direction are shifted by a half pitch in the longitudinal direction. Even when the slits are arranged in this manner, an oblique electric field can be generated, and good display quality by multi-domain can be realized.

  In the liquid crystal display element having the slit arrangement as shown in FIG. 11, for example, the slit pattern shown in FIGS. 8A and 8B is ½ in the slit length direction relative to the position where the center lines are overlapped. It can be manufactured using a mask manufactured by shifting the pitch.

  In the drawings for explaining the embodiments, for example, the transparent electrodes are formed and arranged so that the horizontal direction of the character “1” and the length direction of the slit are parallel to each other. However, for example, the transparent electrode can be formed and arranged so that the horizontal direction of the character and the length direction of the slit intersect (for example, the length direction of the slit is oblique to the horizontal direction of the character). .

  In the embodiments, the vertical alignment type liquid crystal display element is taken up, but the present invention can also be applied to a TN type liquid crystal display element, an STN type liquid crystal display element, or the like.

  As mentioned above, although this invention was demonstrated along the Example, this invention is not limited to these. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

  The present invention can be used for a liquid crystal display element having a transparent electrode provided with a slit and its manufacture.

It is a schematic plan view which shows the display area of a liquid crystal display element, (B) and (C) are a common electrode (transparent electrode 36 of the upper side substrate 32) and a segment electrode (transparent electrode 35 of the lower side substrate 31), respectively. FIG. It is sectional drawing which shows the outline of the vertical alignment type liquid crystal display element by a previous proposal. (A)-(D) are the figures for demonstrating arrangement | positioning of the slits 35a and 36a in the display unit 71 of a liquid crystal display element. (A) And (B) is sectional drawing for demonstrating the effect | action and effect of the liquid crystal display element by a previous proposal. It is a top view which shows a part of display area 70 of a liquid crystal display element of a simple matrix type dot matrix type. It is a schematic top view which shows several pixels of the TFT active matrix liquid crystal display element which is another example of a dot matrix type. FIGS. 3A to 3E are schematic views for explaining an example of a method for manufacturing a simple segment type vertically aligned liquid crystal display element having the display unit 71 shown in FIGS. . (A) And (B) is a figure which shows the outline of the slit pattern used when producing a mask. (A) And (B) is a schematic diagram for demonstrating a part of process of producing a mask, (C) And (D) is a schematic plan view which shows the produced mask. is there. It is the microscope picture which image | photographed the display unit 71 of the solid-state image sensor which formed the transparent electrodes 35 and 36 using the produced mask from the normal line direction of the board | substrate. It is the schematic plan view which showed a part of display unit 71 of a liquid crystal display element. It is sectional drawing which shows the prior art example of a liquid crystal display element (Liquid Crystal Display) of a vertical alignment type.

Explanation of symbols

4 oblique electric field 20 TFT element 22 source line 23 gate line 31 lower substrate 32 upper substrate 33, 34 transparent substrate 35, 36 transparent electrode 35a, 35a1,..., 35an slit 36a, 36a1, ... 36an slit 37, 38 Vertical alignment film 39 Liquid crystal layer 39a Liquid crystal 40 Viewing angle compensation films 41, 42 Polarizing plate 43 Voltage applying means 50 Vertical alignment type LCD
70 Display region 71 Display unit 90 Mask D Drain electrode G Gate electrode S Source electrode α, β, γ, δ Small region

Claims (11)

A method of manufacturing a liquid crystal display element that performs display in a display region including at least one display unit,
(A) forming a first transparent conductive material film on the first substrate;
(B) forming a second transparent conductive material film on the second substrate;
(C) data of an area including at least a part of the display area, and the first and second electrode pattern data of the opposing area including at least one display unit in the area are relatively relative to each other Each of the aligned first and second slit pattern data is overlaid, and when the completed substrate is placed oppositely and viewed from the normal direction of the substrate, the slit pattern formed on each substrate is the slit pattern. Producing first and second reticles arranged alternately in the width direction;
(D) transferring the first and second reticles, respectively, and forming first and second masks of electrode patterns including slit patterns on the first and second transparent conductive material films, respectively. When,
(E) etching the first transparent conductive material film on which the first mask is formed to form a first transparent electrode including the first slit pattern on the first substrate; ,
(F) etching the second transparent conductive material film on which the second mask is formed to form a second transparent electrode including the second slit pattern on the second substrate; ,
(G) forming first and second alignment films on the first and second substrates, respectively, so as to cover the first and second transparent electrodes;
(H) A method of manufacturing a liquid crystal display element, comprising: a step of facing and bonding the first and second substrates to the first and second alignment films so as to face each other substantially in parallel. 2. The method of manufacturing a liquid crystal display element according to claim 1, wherein the first and second slit patterns have substantially rectangular slits repeatedly arranged at a constant pitch in a length direction and a width direction. 3. The method for manufacturing a liquid crystal display element according to claim 1, wherein in the step (c), the first and second reticles are manufactured so as to have a slit only in a display unit. Furthermore, in the said process (c), the said 1st and 2nd reticle is produced so that the edge of a slit may align along the width direction, The manufacture of the liquid crystal display element of any one of Claims 1-3 Method. Furthermore, in the said process (c), the said 1st and 2nd reticle is created so that the slit adjacent to the width direction may shift | deviate by a half pitch in the length direction. A method for manufacturing a liquid crystal display element. A first substrate;
A first transparent electrode formed on one surface of the first substrate and having a plurality of first slit-like openings distributed two-dimensionally;
A first alignment film formed on one surface of the first substrate so as to cover the first transparent electrode;
A second substrate disposed substantially parallel to the first substrate;
The second substrate includes a display unit that is formed on a surface of the second substrate facing the first substrate and overlaps with the first transparent electrode when viewed from the normal direction of the first and second substrates. A second transparent electrode defining a region and having a plurality of second slit-shaped openings distributed in a two-dimensional manner alternately arranged in the width direction with the first slit-shaped openings;
A second alignment film formed on the surface of the second substrate facing the first substrate so as to cover the second transparent electrode;
When viewed from the normal direction of the first and second substrates, the intersection of the slit and the outer periphery with respect to the outer periphery of the display unit and the intersection of the first and second slit-shaped openings or their extensions. A liquid crystal display element in which the number of parts is greater than the number of slits extending and the outer intersections. The liquid crystal display element according to claim 6, wherein the first and second slit-shaped openings are both formed in a substantially rectangular shape. The liquid crystal display element according to claim 7, wherein the first and second slit-shaped openings are formed at a constant pitch in a length direction and a width direction of the openings. The liquid crystal display according to claim 8, wherein when viewed from the normal direction of the first and second substrates, edges of the first and second slit-like openings are aligned along the width direction. element. The first and second slit-like openings adjacent to each other when viewed from the normal line direction of the first and second substrates are shifted by a half pitch in the length direction. Liquid crystal display element. The liquid crystal display element according to claim 6, wherein the first and second slit-shaped openings are formed only inside the display unit.