JP5192423B2 - Liquid crystal display element and manufacturing method thereof - Google Patents

Description

  The present invention relates to a liquid crystal display (LCD) and a manufacturing method thereof.

  Many liquid crystal display elements in which a film-like polarizing plate is disposed outside the liquid crystal cell are manufactured. For example, a wire grid polarizer composed of fine metal wires (wires) arranged in one direction with a period of half or less of the wavelength of light to be used is also known. A liquid crystal display element in which a wire grid polarizer is formed inside a liquid crystal cell is also known (see, for example, Patent Document 1). Patent Document 1 describes a technique related to the formation of an absorption layer that absorbs a polarized light (TE (Transverse Electric) polarized light) component parallel to the wire of a wire grid polarizer, in order to prevent a decrease in contrast particularly in a bright place. ing.

  A film-like polarizing plate has low durability against heat, humidity, light, and the like. For this reason, in a liquid crystal display element having a configuration in which a polarizing plate is disposed outside the liquid crystal cell, the reliability of the liquid crystal display element may be reduced due to deterioration of the polarizing plate even if there is no problem with the liquid crystal cell. .

  In addition, the liquid crystal display element also has a problem that its responsiveness deteriorates under low temperature conditions. To cope with this, for example, countermeasures such as attaching a transparent heater formed of ITO (Indium Tin Oxide) can be considered. However, there are disadvantages such as a significant increase in cost, a decrease in the light transmittance of the liquid crystal cell, and an increase in the thickness of the liquid crystal display element.

  Furthermore, the liquid crystal display element also has a problem that it malfunctions due to static electricity. As a countermeasure against static electricity, there is a method of coating a transparent conductive film on a polarizing plate or a glass substrate of a liquid crystal cell. This also leads to a significant increase in cost and a decrease in light transmittance of the liquid crystal cell.

JP 2008-102416 A

  An object of the present invention is to provide a liquid crystal display element capable of realizing good display.

  Another object of the present invention is to provide a manufacturing method capable of manufacturing a liquid crystal display element capable of realizing good display at a low cost.

According to one aspect of the present invention, a first transparent substrate and a second transparent substrate disposed opposite to the first transparent substrate, wherein a plurality of metal lines are formed in parallel, and a wire grid polarizer A second transparent substrate on which a metal film having a first pattern that functions as a second pattern that electrically connects the first pattern is disposed, the first transparent substrate, and the second pattern A liquid crystal layer sandwiched between the transparent substrate, a transparent electrode provided on the first transparent substrate and the second transparent substrate, and the first transparent substrate or the second transparent substrate. possess a first electric circuit which is a transparent electrode and electrically connected to the metal film of the second transparent substrate, it is formed on the liquid crystal layer side, and different from the second pattern A third pattern electrically connecting the first pattern at a position; The terminal portions of the second and third patterns are formed at the end portions of the second transparent substrate, and are further formed at the end portions of the second transparent substrate. A second electric circuit different from the first electric circuit, which is connected between the terminal portions of the pattern and can flow current between the second and third patterns, and further includes a plurality of metal wires Are provided in parallel, and a liquid crystal display element is provided in which a metal film including a pattern that functions as a wire grid polarizer and a pattern that electrically connects the pattern is disposed on the first transparent substrate .

  ADVANTAGE OF THE INVENTION According to this invention, the liquid crystal display element which can implement | achieve favorable display can be provided.

  In addition, it is possible to provide a manufacturing method capable of manufacturing a liquid crystal display element capable of realizing good display at low cost.

It is a flowchart which shows the manufacturing method of the liquid crystal display element by a 1st Example. It is a schematic top view which shows the pattern of a photomask. It is a graph which shows the measurement result of the light transmittance of a board | substrate with a polarizing film. When, (A) And (B) is a graph which shows the angle dependence of the light transmittance at the time of bonding a board | substrate with a polarizing film, and a general polarizing film, (C) and (D) are general It is a graph which shows that at the time of piling up two polarizing films. (A) And (B) is the schematic sectional drawing and top view of the liquid crystal display element by a 1st Example, respectively. (A) And (B) is a figure for demonstrating the manufacturing method of the liquid crystal display element by a 2nd Example. It is a schematic sectional drawing of the liquid crystal display element by a 2nd Example. It is a flowchart which shows the manufacturing method of the liquid crystal display element by a 3rd Example. It is a schematic sectional drawing of the liquid crystal display element by a 3rd Example.

  FIG. 1 is a flowchart showing a method of manufacturing a liquid crystal display device according to the first embodiment.

  First, a substrate with a polarizing film (a substrate with a wire grid polarizer) is produced. The substrate with a polarizing film is manufactured by a process including step S101 (metal sputtering process) and step S102 (metal patterning process).

  In step S101 (metal sputtering step), for example, a molybdenum (Mo) film having a thickness of 1000 mm is formed by sputtering on a cleaned glass substrate having a thickness of 0.7 mm. The thickness of the Mo film may be 300 mm or more, but if it is thin, light leakage occurs, and if it is thick, the patterning property is lowered. Note that the conductive film on the glass substrate is not limited to Mo, and can be formed of a metal such as chromium or titanium.

  In step S102 (metal patterning step), a positive type high-resolution photoresist material is coated on the Mo film to a thickness of 1 μm by spin coating. Not only spin coating but also slit coating, roll coating, combined use of spin coating and slit coating, and the like may be performed. The thickness of the resist film is suitably from 0.1 to 1.5 μm.

  Subsequently, exposure is performed by placing a photomask (reticle) on the resist film.

  FIG. 2 is a schematic plan view showing a photomask pattern. The mask pattern includes a linear pattern 60c portion in which linear light-transmitting areas and light-shielding areas are alternately formed, and a solid pattern that connects each end of the linear pattern 60c with the horizontal direction in the drawing as the length direction. 60d portion. Both the linear light transmitting region and the light shielding region are formed with a width of about 0.1 μm. That is, the linear patterns 60c are formed at a pitch of 0.2 μm in the vertical direction of the drawing. The illustrated mask pattern is a mask for manufacturing eight substrates with a polarizing film.

The exposure was performed at a fluence of, for example, 80 mJ / cm ² in accordance with the sensitivity of the resist.

  After exposure, pre-baking is performed and development is performed. An inorganic alkaline aqueous solution of KOH was used as the developer. Commercially available developers can also be used. As a commercially available developer, for example, tetramethylammonium hydroxide (TMAH) generally used for developing a positive resist for lithography can be used.

  The linear pattern 60c portion of the mask (reticle) can be manufactured using an interference exposure system using a laser or a reduced exposure system using a mask. In the example, a pattern was produced with an optical interference system of a He—Cd laser.

  Subsequently, etching is performed by, for example, wet etching. A mixed solution of phosphoric acid, nitric acid, acetic acid and water was used as an etchant. Etching was performed at room temperature and was completed in about 10 seconds.

Etching may be performed by dry etching. When the film on the glass substrate is formed of molybdenum or titanium, CF ₄ , C ₂ F ₄ , C ₂ F ₆ , C ₃ F ₆ , C ₃ F ₈ , C ₄ F ₈ , C ₄ F ₁₀ , C _{5 F 8, C 6 F 14} , CF 3 CFOCF 2, C 6 F 5 CF 2 CFCF 2, CF 3 Br, CF 3 I, C 2 F 5 I, SF 6, NF 3, WF 6, C 2 F 5 _{Cl, C 2 F 4 Cl 2} , CF 3 Cl, CF 2 Cl 2, CFCl 3, CHF 3, CH 2 F 2, CHF 2 CF 3, CH 2 FCF 3, CH 3 CHF 2, C 2 H 3 F 3 C ₃ HF ₇ , CF ₃ CH ₂ CF ₃ , C ₆ F ₅ CHCH _2, or the like can be used. Also, if the film on the glass substrate is formed by _{chromium, Cl 2, CCl 4, SiCl} 4, BCl 3, PCl 3, CBrF 3, BBr 3, C 2 ClF 5, C 2 Cl 2 F 4, CClF ₃ , CCl ₂ F ₂ , CCl ₃ F, HCl, CH ₂ Cl ₂ , CHCl ₃ , HBr, or the like can be used.

  After the etching, the resist was removed using an aqueous NaOH solution. Organic remover and ashing may be used.

  Thus, a substrate with a polarizing film was completed. FIG. 2 is also a diagram showing a polarizing film pattern of a substrate with eight polarizing films (Mo film). A substrate with a polarizing film (substrate with a wire grid polarizer) includes a glass substrate and a polarizing film formed of Mo on the glass substrate. The polarizing film includes a linear pattern 60c portion and a solid pattern 60d portion connecting each end of the linear pattern 60c portion. The length direction of the linear pattern 60c is the left-right direction in the figure, and the width direction is the up-down direction in the figure. The linear patterns 60c are formed at a pitch of 0.2 μm in the width direction. The width of each line of the linear pattern 60c is approximately 0.1 μm.

  The linear pattern 60c portion is disposed at least in the display region corresponding to the display region of the manufactured liquid crystal display element, and the solid pattern 60d portion is disposed outside the display region.

  The inventors of the present application measured the light transmittance of the produced polarizing film-coated substrate from the normal direction of the substrate. In the measurement, considering the possibility that the emitted light from the light source contains a polarization component, each of the cases where the polarizing film-coated substrate is placed vertically and placed horizontally (90 ° shifted), The light transmittance was measured and the average value was calculated.

  FIG. 3 is a graph showing the measurement results of the light transmittance of the substrate with a polarizing film. The horizontal axis of the graph represents the wavelength of light incident on the polarizing film-coated substrate in the unit “nm”, and the vertical axis represents the light transmittance in the unit “%”. The light transmittance is shown as 100% when the light is transmitted through a glass substrate having the same thickness (0.7 mmt) as the polarizing film-coated substrate. The curve connecting the white squares shows the relationship between the wavelength of light and the transmittance when the polarizing film-coated substrate is placed sideways (in the case of a horizontal arrangement). The curve connecting the white circles shows the relationship between the two when the polarizing film-coated substrate is placed vertically (in the case of the vertical arrangement). Moreover, the curve which connected the black circle shows the average in the case of horizontal arrangement | positioning, and the case of vertical arrangement | positioning. The light transmittance of the produced polarizing film-coated substrate is considered to be represented by a curve connecting black circles.

  From the graph, it is recognized that the light transmittance of the substrate with the polarizing film is 44% regardless of the wavelength. This value was higher than the light transmittance of a general polarizing film (about 42% as measured by the same measurement method).

  Next, in order to investigate the degree of polarization of the produced polarizing film-coated substrate, the inventors of the present application bonded the polarizing film-coated substrate and a general polarizing film, and measured the light transmittance characteristics.

  4 (A) and 4 (B) are graphs showing the angle dependency of light transmittance when a polarizing film-coated substrate and a general polarizing film are bonded together, and FIGS. 4 (C) and 4 (D). These are graphs showing that when two general polarizing films are stacked. The horizontal axis of each graph represents the incident angle of the incident light in the unit “°”, and the vertical axis represents the light transmittance in the unit “%”. The curve connecting the black circles shows the incident angle dependence of the light transmittance when a substrate with a polarizing film and a general polarizing film, or two general polarizing films are arranged in parallel Nicols, connecting black squares The curved line shows that when placed in crossed Nicols. 4B and 4D are curves obtained by enlarging the crossed Nicols curves of FIGS. 4A and 4C, respectively.

  FIG. 4A and FIG. 4C are compared and contrasted. It can be seen that the light transmittance at the time of parallel Nicol arrangement is high when the produced polarizing film-coated substrate is used (FIG. 4A), which is preferable. The incident angle dependence of the light transmittance when the parallel Nicols are arranged (the degree of the curve) is not significantly different between the cases shown in FIGS. 4 (A) and 4 (C).

  FIG. 4B and FIG. 4D are compared and contrasted. The light transmittance (light omission) at the time of crossed Nicol arrangement is high when the produced substrate with a polarizing film is used (FIG. 4B). However, this point may be overcome by optimizing the conditions. In the case of using a substrate with a polarizing film (FIG. 4B), light leakage is remarkable when the incident angle of light is 60 ° or more. When the produced polarizing film-coated substrate is used as a polarizing plate, it is desirable to devise measures such as increasing the directivity of the backlight so that the incident angle of light to the display region does not exceed 60 °. I will.

  Reference is again made to FIG. A segment substrate and a common substrate are manufactured before, after, or in parallel with the manufacturing of the polarizing film-coated substrate.

  In steps S103 and S104, a transparent electrode is formed of, for example, ITO on two transparent substrates, for example, a glass substrate having a thickness of 0.7 mm. The transparent electrode is formed by etching an ITO film formed by vapor deposition or sputtering on a glass substrate into a desired ITO pattern by a photolithography process. The substrate on which the segment electrode is formed is called a segment substrate, and the substrate on which the common electrode is formed is called a common substrate.

  A TFT (Thin Film Transistor) matrix may be formed on the segment substrate. A color filter (CF) pattern can be formed on the common substrate.

  In addition, you may produce the same pattern as the ITO pattern of a segment board | substrate in the surface different from the polarizing film formation surface of a board | substrate with a polarizing film. In that case, it is desirable to protect the surface of the polarizing film by attaching a protective film, forming a coating film, or the like. Moreover, it is also possible to produce a pattern similar to the CF pattern of the common substrate on a surface different from the polarizing film forming surface of the substrate with the polarizing film.

  An insulating film is formed by, for example, flexographic printing on the segment substrate on which the ITO pattern is formed and the common substrate. Further, a vertical alignment film is formed on the insulating film in, for example, a pattern substantially the same as the insulating film. The alignment film is subjected to an alignment process, for example, by rubbing. The rubbing process is performed, for example, so that the alignment state between the upper and lower substrates is antiparallel (antiparallel).

  Through the processes of steps S103 and S104, a segment substrate and a common substrate in which the patterned ITO electrode, the insulating film, and the alignment film subjected to the alignment process are formed in this order are obtained.

  In step S105, cell conversion is performed. A main seal pattern is printed on one substrate, for example, a segment substrate, and a gap control agent is sprayed on the other substrate, for example, a common substrate. A substrate on which ribs are formed in advance may be used. Thereafter, a liquid crystal layer is formed between the segment substrate and the common substrate using, for example, a liquid crystal material having a negative dielectric anisotropy Δε to produce a liquid crystal cell. The liquid crystal layer may be formed by using either a vacuum injection method or a liquid crystal drop injection method (One Drop Filling; ODF).

  Step S106 is a superposition process. A substrate with a polarizing film is placed on the segment substrate of the liquid crystal cell in a direction in which the polarizing film (Mo film) contacts the cell. The substrate with the polarizing film and the segment substrate are not attached.

  In step S107, a dichroic film type polarizing plate is attached to the common substrate. The polarizing film on the segment substrate side and the polarizing plate on the common substrate side are arranged so that the polarization axes are orthogonal to each other (crossed Nicols) and the polarization axis forms an angle of 45 ° with the rubbing direction. To do.

  In step S108, the terminal part of the liquid crystal cell and the drive circuit are connected by a flexible printed circuit (FPC). Further, the terminal part of the solid pattern 60d portion of the polarizing film-coated substrate and the DC circuit are connected by a harness.

  5A and 5B are a schematic cross-sectional view and a plan view, respectively, of the liquid crystal display element according to the first embodiment.

  Reference is made to FIG. The liquid crystal display device according to the first embodiment includes a common substrate 20, a segment substrate 30, a vertically aligned liquid crystal layer 40 sandwiched between both substrates 20, 30, and a substrate 60 with a polarizing film. It is comprised including.

  The common substrate 20 includes a transparent substrate 21, a transparent electrode (common electrode) 22 formed on the transparent substrate 21, an insulating film 23 formed on the transparent electrode 22, and an alignment film 24 formed on the insulating film 23. Including. Similarly, the segment substrate 30 includes a transparent substrate 31, a transparent electrode (segment electrode) 32 formed on the transparent substrate 31, an insulating film 33 formed on the transparent electrode 32, and an orientation formed on the insulating film 33. A membrane 34 is included.

  The transparent substrates 21 and 31 are, for example, glass substrates. The transparent electrodes 22 and 32 are made of, for example, ITO. The alignment films 24 and 34 are subjected to an anti-parallel alignment process, for example, by rubbing.

  The liquid crystal layer 40 is a vertically aligned liquid crystal layer. A voltage is applied to the liquid crystal layer 40 by the drive circuit 71 electrically connected to the terminal portion 32a of the transparent electrode (segment electrode) 32 via the flexible printed circuit board 70.

  A polarizing plate 50 and a polarizing film-coated substrate 60 are disposed on the surface of the transparent substrates 20 and 30 opposite to the liquid crystal layer 40, respectively. The polarizing plate 50 and the substrate 60 with a polarizing film are formed such that the polarizing axis of the polarizing plate 50 and that of the substrate 60 with a polarizing film are orthogonal to each other (in a crossed nicols), and the polarizing axes are the substrates 20 and 30. It is arranged so as to form an angle of 45 ° with respect to the rubbing direction.

  The polarizing plate 50 is a dichroic film type polarizing plate and is attached to the transparent substrate 21 of the common substrate 20.

  The polarizing film-coated substrate 60 includes a transparent substrate 60b made of glass, for example, and a polarizing film 60a made of Mo on the transparent substrate 60b. The substrate 60 with a polarizing film is placed on the segment substrate 30 so that the polarizing film 60 a is in contact with the segment substrate 30. The polarizing film-coated substrate 60 and the segment substrate 30 are not attached to each other. The DC circuit 72 is electrically connected to the polarizing film 60a of the polarizing film-coated substrate 60 with a harness.

  The backlight 80 is disposed on the polarizing film-coated substrate 60 side of the liquid crystal cell. The light emitted from the backlight 80 enters the display area of the liquid crystal cell at an incident angle of less than 60 °.

  Since there is the metal polarizing film 60a between the liquid crystal cell and the backlight 80, the polarization component that does not pass through the polarizing film 60a out of the light emitted from the backlight 80 is reflected to the backlight 80 side on the surface of the polarizing film 60a. After that, it is re-reflected and reused while depolarizing. For this reason, the liquid crystal display element according to the first embodiment can perform display with high luminance.

  FIG. 5B is a plan view of the liquid crystal display element according to the first embodiment as viewed from the backlight 80 side.

  The polarizing film 60a of the substrate 60 with a polarizing film includes a linear pattern 60c portion and a solid pattern 60d portion in which a plurality of thin metal lines are arranged in parallel. The linear pattern 60c portion is formed, for example, in a range of 20 mm (horizontal direction in the figure, width direction of the linear pattern) × 25 mm (vertical direction in the figure, length direction of the linear pattern) and functions as a wire grid polarizer. To do. The two solid patterns 60d are electrically connected to the ends of the linear pattern 60c.

  A terminal portion 60e electrically connected to each solid pattern 60d is formed at the end of the substrate 60 with a polarizing film. The DC circuit 72 is connected between the two terminal portions 60e, and can pass a current through the polarizing film 60a (the linear pattern 60c portion and the solid pattern 60d portion). The resistance value between the two terminal portions 60e is, for example, 22Ω. By causing a current to flow between the two terminal portions 60e in the DC circuit 72, the linear pattern 60c portion can function as a heater based on the principle of resistance heating.

  The inventors of the present application conducted several tests on the liquid crystal display element according to the first embodiment.

  First, the light transmittance was measured when a voltage was applied to the liquid crystal layer 40 and when it was not applied. As a result, the light transmittance when no voltage was applied was 0.23%, the maximum light transmittance when voltage was applied was 33%, and the contrast ratio was about 140. Since the liquid crystal display element according to the first embodiment includes the polarizing film 60a that functions as a wire grid polarizer, good display is possible.

  Next, the measurement regarding the heater function of the polarizing film 60a of the board | substrate 60 with a polarizing film was performed. The inventors of the present application confirmed that the temperature of the liquid crystal display element, which was in the initial state of −30 ° C., becomes about 0 ° C. after 1 minute by applying current to the polarizing film 60a and heating it with the DC circuit 72. Since the polarizing film 60a having a heater function is in contact with the segment substrate 30 (transparent substrate 31), it is considered that the liquid crystal layer 40 was heated in a short time. Also, with this heating, the response time (total time required for rising and falling), which was 4000 msec in the initial state, was reduced to 200 msec after 1 minute. The liquid crystal display element according to the first embodiment is a liquid crystal display element capable of preventing damage and deterioration of function due to low temperature. In addition, the liquid crystal display element can achieve high responsiveness.

  Finally, the effect on static electricity was examined. A sample LCD (the LCD shown in FIG. 5A excluding the backlight 80) is placed on an insulating plate (bake plate having a thickness of 5 mm) so that the polarizing film-coated substrate 60 is in contact with the insulating plate. In the center of the display area of the sample LCD, contact discharge was performed once for 1 second with an electrostatic gun, and the time until the liquid crystal turned on by electrostatic charging completely returned to the original surface was measured. The measurement was performed under conditions of a temperature of 22 ° C., a humidity of 36%, a capacitance of 150 pF, an electric resistance of 330Ω, and an applied voltage of 15 kV. For the measurement, an electrostatic test machine SEE-200AX of Noise Research Co., Ltd. was used.

  In a normal liquid crystal display element, a malfunction occurred due to static electricity of a high voltage of 15 kV, and the malfunction continued for 3 minutes or more particularly in a portion where no electrode was formed. In contrast, the sample LCD did not malfunction. From this, it can be seen that the sample LCD is a liquid crystal display element that is extremely resistant to static electricity. When the harness was removed from the sample LCD and the static electricity resistance of the LCD excluding the DC circuit 72 was examined under the same conditions, a malfunction in a short time (within 10 seconds) was observed. It can be seen that even when the DC circuit 72 is not conducted, a high static electricity resistance effect is exhibited. The static electricity resistance effect is achieved by electrically connecting the linear pattern 60c portion. For this reason, if there is at least one solid pattern 60d portion, an electrostatic resistance effect can be obtained.

  In the liquid crystal display element according to the first embodiment, the polarizing film 60a has both a function as a polarizing plate, a function as a heater, and a function for realizing high electrostatic resistance. Realization is possible.

  In addition, according to the method of manufacturing the liquid crystal display element according to the first embodiment, for example, a process for forming an ITO film for a heater, a coating process for an antistatic material, and the like are not required. Can be manufactured.

  When the ITO film for the heater is separately formed, there is a problem that the light transmittance of the liquid crystal display element is reduced due to the light transmittance and refractive index of the ITO. In the liquid crystal display device according to the above, the light transmittance is not lowered. As described with reference to FIG. 3, the light transmittance of the polarizing film-coated substrate is higher than the light transmittance of a general polarizing film, so that the light transmittance of the liquid crystal display element is rather high.

  Further, in the method of manufacturing the liquid crystal display element according to the first embodiment, the polarizing film-coated substrate 60 and the segment substrate 30 are not attached, so the cut polarizing plate is attached to the segment substrate 30 to provide the liquid crystal display element. Compared with the case of manufacturing the liquid crystal display device, the liquid crystal display element can be manufactured with fewer steps and lower costs. This merit is particularly remarkable when liquid crystal is injected by ODF. In addition, you may adhere | attach the both board | substrates 30 and 60 with an adhesive agent, for example. In this case, it is possible to suppress the loss of light at the interface between the substrates 30 and 60 by adopting an adhesive having a refractive index equivalent to that of the glass substrate (about 1.5). Display can be made.

  With reference to FIGS. 6A and 6B, a method of manufacturing a liquid crystal display device according to the second embodiment will be described. In the liquid crystal display element according to the first embodiment, the polarizing film-coated substrate 60 is produced and the polarizing film 60a is disposed on the opposite side of the segment transparent substrate 31 from the liquid crystal layer 40. However, the liquid crystal display element according to the second embodiment is The polarizing film 60a is formed on the segment transparent substrate 31, and the polarizing film 60a is disposed on the liquid crystal layer 40 side.

  Reference is made to FIG. In steps S201 to S204, a segment substrate is manufactured. The segment substrate in the second embodiment is a segment substrate with a polarizing film.

  For example, a polarizing film is formed on a glass substrate having a thickness of 0.7 mm by the metal sputtering process in step S201 and the metal patterning process in step S202. The method for forming the polarizing film is the same as that in the first embodiment (metal sputtering step S101 and metal patterning step S102). Eight polarizing film (Mo film) patterns as shown in FIG. 2 are formed on one glass substrate. The linear pattern 60c portion of the polarizing film is formed so as to be disposed at least in the display region corresponding to the display region of the liquid crystal display element to be manufactured, and the solid pattern 60d portion is disposed outside the display region. The points formed are the same.

In step S203, an insulating film is formed on the polarizing film pattern. The insulating film can be formed by sputtering, CVD, printing or the like using a mask formed of SUS, for example. In the second embodiment, SiO ₂ was sputtered using a flexographically printed resist material as a mask, and an insulating film pattern was formed only on a necessary portion of the polarizing film by using a lift-off method. FIG. 6B shows the formed insulating film pattern (SiO ₂ pattern) 60f.

In step S204, a transparent electrode having a predetermined shape is formed of, for example, ITO on the insulating film (SiO ₂ film). Alternatively, a TFT matrix may be formed.

  In step S205, a common substrate is produced. For example, a transparent electrode is formed in a predetermined shape with ITO on a glass substrate having a thickness of 0.7 mm. A color filter (CF) pattern may be formed.

  Similar to the first embodiment, an insulating film and an alignment film are formed on the transparent electrodes of the common substrate and the segment substrate and an alignment process is performed. Instead of performing the alignment treatment on the alignment film, the alignment state of the liquid crystal molecules may be defined by forming a slit in the transparent electrode or forming a protrusion on the substrate.

  In step S206, a liquid crystal layer is formed between the segment substrate and the common substrate by a liquid crystal dropping injection method (ODF) to manufacture a liquid crystal cell. A gap control agent is sprayed on one substrate, for example, a common substrate, and a closed main seal pattern is printed on the other substrate, for example, a segment substrate. Then, a predetermined amount of liquid crystal is dropped inside the seal pattern, and both substrates are superposed in a vacuum to produce a vertical alignment type liquid crystal cell as in the first embodiment.

  In step S207, a dichroic film type polarizing plate is attached to the common substrate. The positional relationship between the polarizing film polarization axis on the segment substrate side and the polarizing plate polarization axis on the common substrate side is the same as in the first embodiment.

  In step S208, the terminal part of the liquid crystal cell and the drive circuit are connected by a flexible printed circuit board (FPC). Further, the terminal part of the solid pattern 60d portion of the segment substrate polarizing film and the DC circuit are connected by a harness.

  FIG. 7 is a schematic cross-sectional view of a liquid crystal display device according to the second embodiment. The liquid crystal display element according to the second embodiment is different from the liquid crystal display element according to the first embodiment in that it does not include the polarizing film-coated substrate 60 and the segment substrate 30 includes the polarizing film 60a. In the second embodiment, the polarizing film 60 a is disposed on the liquid crystal layer 40 side of the segment transparent substrate 31. The segment substrate 30 includes a polarizing film 60a formed on the transparent substrate 31, and a transparent electrode 32, an insulating film 33, and an alignment film 34 formed thereon via an insulating film 35.

  The plan view of the liquid crystal display element according to the second embodiment is the same as that of the first embodiment (FIG. 5B). The polarizing film 60a of the segment substrate 30 includes a linear pattern 60c portion and a solid pattern 60d portion, and the two solid pattern 60d portions electrically connect each end of the linear pattern 60c portion.

  A terminal portion 60e electrically connected to each solid pattern 60d is formed at the end of the segment substrate 30 (transparent substrate 31), and a DC circuit 72 is connected between the two terminal portions 60e. The DC circuit 72 can pass a current through the polarizing film 60a (the linear pattern 60c portion and the solid pattern 60d portion).

  Also in the liquid crystal display element according to the second embodiment, the polarizing film 60a has a function as a wire grid polarizer, a function as a heater, a function of realizing electrostatic resistance, a function of improving luminance, and the like. The effect of the liquid crystal display element according to the second embodiment is almost the same as that of the first embodiment, but the polarizing film 60a is disposed inside the liquid crystal cell (on the liquid crystal layer 40 side of the transparent substrate 31). The heating of the liquid crystal layer 40 can be more effective than the first embodiment. For this reason, for example, higher responsiveness than the first embodiment can be realized. Further, since the polarizing film 60a (the linear pattern 60c portion) is formed inside the liquid crystal cell, it is not affected by humidity and can exhibit higher reliability than that of the first embodiment.

  In the first and second embodiments, a dichroic film type polarizing plate 50 is provided on the front side (observer side) of the liquid crystal display element, and a wire grid polarizing film (metal polarizing film 60a is provided on the back side (backlight 80 side). A linear pattern 60c) was arranged. When the metal polarizing film 60a is used on the front side of the liquid crystal display element, there is a problem that external light is reflected due to surface reflection and the display quality of the liquid crystal display element is deteriorated. Therefore, an antireflection film such as an optical multilayer film is used. It is desirable to form. If the configurations of the first and second embodiments are adopted, the problem of deterioration in display quality due to external light can be avoided, and the cost for forming the antireflection film can be reduced. In addition, since commercially available polarizing films often have a degree of polarization superior to that of metal polarizing films, it is possible to realize high contrast display by arranging metal polarizing films on both the front and back surfaces of a liquid crystal display element. is there. If a metal polarizing film is used, the function as a heater, the function of realizing static electricity resistance, the function of improving luminance, and the like are maintained even on the back surface alone. In particular, static electricity resistance can be further enhanced by electrically connecting the metal polarizing film to a circuit or grounding it.

  With reference to FIG. 8, the manufacturing method of the liquid crystal display element by the 3rd Example is demonstrated. In the liquid crystal display element according to the second embodiment, the metal polarizing film is formed only on the segment substrate side. However, in the third embodiment, the metal polarizing film is also formed on the inner side of the liquid crystal cell on the common substrate side.

  In steps S301 to S304, a common substrate is manufactured. Steps S301 to S303 are the same as steps S201 to S203 in the second embodiment. By these steps, for example, a pattern of a metal film and an insulating film as shown in FIG. 6B is formed on a transparent glass substrate.

  In step S304, a transparent electrode having a predetermined shape is formed of, for example, ITO on the insulating film. A color filter (CF) may be formed.

  Similarly, a segment substrate is manufactured in steps S305 to S308. In the segment substrate, the terminal portion of the metal polarizing film is not essential, and only a solid pattern connecting the linear pattern and each end thereof may be used. Furthermore, the insulating film formed on the metal polarizing film pattern can be formed on the entire surface without patterning. Note that the pattern is formed so that the length direction of the linear pattern is orthogonal to the common substrate.

  In step S308, a transparent electrode having a predetermined shape is formed of, for example, ITO on the insulating film. A TFT matrix may be formed.

  An insulating film and an alignment film are formed on the transparent electrodes of the common substrate and the segment substrate, and an alignment process is performed.

  In step S309, a vertical liquid crystal layer is formed between the segment substrate and the common substrate by a liquid crystal dropping injection method (ODF) to manufacture a liquid crystal cell. The steps such as the application of the gap control agent, the printing of the main seal pattern, and the dropping of the liquid crystal are the same as those in the first and second embodiments.

  In step S310, the terminal part of the liquid crystal cell and the drive circuit are connected by a flexible printed circuit board (FPC). Further, the terminal portion of the solid pattern 60d portion of the common substrate polarizing film and the DC circuit are connected by a harness. In addition, when the terminal part and the insulating film pattern as shown in FIG. 6B are also formed on the polarizing film of the segment substrate, the terminal part of the solid pattern 60d portion of the segment substrate polarizing film, the DC circuit, Can also be electrically connected.

  In the method for manufacturing a liquid crystal display element according to the third embodiment, since a metal polarizing film is formed on both the segment substrate and the common substrate, a step of attaching a polarizing plate to the outside of the liquid crystal cell is unnecessary. For this reason, it is possible to reduce the manufacturing cost of a liquid crystal display element.

  FIG. 9 is a schematic cross-sectional view of a liquid crystal display device according to the third embodiment. The liquid crystal display element according to the third embodiment is a liquid crystal display element having a metal polarizing film 60a inside the liquid crystal cell on both the common substrate 20 side and the segment substrate 30 side.

  The liquid crystal display device according to the third embodiment is different from the second embodiment in that the liquid crystal display element does not include the polarizing plate 50 and the common substrate 20 includes the metal polarizing film 60a and the insulating film 25. Further, the DC circuit 72 is connected not to the segment substrate 30 but to the polarizing film 60 a of the common substrate 20. A DC circuit that is the same as or different from the DC circuit 72 connected to the common substrate 20 can be connected to the polarizing film 60 a of the segment substrate 30. The DC circuit 72 only needs to be connected to at least one of the common substrate 20 and the segment substrate 30.

  The plan view of the liquid crystal display element according to the third embodiment viewed from the common substrate 20 side is the same as the plan view of the first and second embodiments (FIG. 5B). The polarizing film 60a of the common substrate 20 includes a linear pattern 60c portion and a solid pattern 60d portion, and the two solid pattern 60d portions electrically connect the respective ends of the linear pattern 60c portion.

  Terminal portions 60e that are electrically connected to the solid patterns 60d are formed at the end of the common substrate 20 (transparent substrate 21), and the DC circuit 72 is connected between the two terminal portions 60e. The DC circuit 72 can pass a current through the polarizing film 60a (the linear pattern 60c portion and the solid pattern 60d portion).

  In the liquid crystal display element according to the third embodiment, the polarizing film 60a of the common substrate 20 has a function as a wire grid polarizer, a function as a heater, a function of realizing electrostatic resistance, and the like. The effect of the liquid crystal display device according to the third embodiment is almost the same as that of the second embodiment. However, since both the common and segment substrates 20 and 30 have the metal polarizing film 60a inside the liquid crystal cell, the humidity is high. Therefore, it is possible to exhibit higher reliability than the second embodiment. Further, display can be performed with higher brightness than in the second embodiment. Further, in the configuration in which the DC circuit is connected to the segment substrate side, the liquid crystal layer 40 can be heated in a shorter time and higher responsiveness can be realized.

  Further, it was confirmed that the electrostatic resistance was higher than that of the first and second examples. In the liquid crystal display element according to the third embodiment, malfunction did not occur in the state where it was connected to the DC circuit 72. When the DC circuit 72 was removed, the malfunction time was very short, within one second. The higher static electricity resistance effect of the third embodiment is considered to be because a conductive polarizing film is formed on the front side (common substrate side) of the liquid crystal display element.

  In the third embodiment, the polarizing film 60a of the common substrate 20 can be formed outside the liquid crystal cell (opposite the liquid crystal layer 40 of the transparent substrate 21). In this case, the insulating film 25 is unnecessary. Although it is desirable to perform a coating such as a hard coat on the polarizing film 60a formed outside the liquid crystal cell, it is not essential. Compared with the case where the polarizing film 60a is formed inside the liquid crystal cell, the heater function is slightly inferior, and there is a concern that the temperature rise of the liquid crystal layer 40 immediately after startup is delayed. However, compared with an external transparent heater, since the polarizing film 60a is integrated with the transparent substrate 21, the temperature rises quickly. The static electricity resistance when the polarizing film 60a of the common substrate 20 was formed outside the liquid crystal cell was almost the same as the case where it was formed inside.

  As mentioned above, although this invention was demonstrated along the Example, this invention is not limited to these.

  You may produce a metal polarizing film by methods other than the patterning method in an Example, for example, the method described in patent document 1. FIG.

    It will be apparent to those skilled in the art that other various modifications, improvements, combinations, and the like are possible.

  For example, it can be used for all types of liquid crystal displays such as in-vehicle displays, display for games, mobile phone / DSC displays, audio displays, personal computer monitor displays, liquid crystal television displays, mobile television displays. In particular, it can be suitably used for a liquid crystal display element that requires high reliability, a liquid crystal display element that requires responsiveness at low temperatures, and a liquid crystal display element that easily generates static electricity when the user directly wipes the display portion. .

20 Common substrate 30 Segment substrate 21, 31 Transparent electrode 22, 32 Transparent electrode 32a Terminal portion 23, 33 Insulating film 24, 34 Alignment film 25, 35 Insulating film 40 Liquid crystal layer 50 Polarizing plate 60 Polarizing film substrate 60a Polarizing film 60b Transparent Substrate 60c Linear pattern 60d Solid pattern 60e Terminal portion 60f SiO ₂ pattern 70 Flexible printed circuit board 71 Drive circuit 72 DC circuit 80 Backlight

Claims (2)

A first transparent substrate;
A second transparent substrate disposed opposite to the first transparent substrate, wherein a plurality of metal lines are formed in parallel and function as a wire grid polarizer , and the first pattern is electrically connected A second transparent substrate on which a metal film having a second pattern to be connected is disposed;
A liquid crystal layer sandwiched between the first transparent substrate and the second transparent substrate ;
Transparent electrodes provided on the first transparent substrate and the second transparent substrate;
Have a <br/> the first electrical circuit the electrically connected transparent electrodes and the first transparent substrate or the second transparent substrate,
The metal film includes a third pattern which is formed on the liquid crystal layer side of the second transparent substrate and electrically connects the first pattern at a position different from the second pattern. ,
The terminal portions of the second and third patterns are formed at the end of the second transparent substrate,
Furthermore, it is connected between the terminal portions of the second and third patterns formed at the end of the second transparent substrate, and a current can flow between the second and third patterns. A second electrical circuit different from the first electrical circuit,
Furthermore, a liquid crystal display element in which a plurality of metal lines are formed in parallel, and a metal film having a pattern that functions as a wire grid polarizer and a pattern that electrically connects the patterns is disposed on the first transparent substrate . The liquid crystal display element according to claim 1, wherein the first pattern functions as a heater by causing a current to flow between the second and third patterns in the second electric circuit.

Images