WO2012102104A1 - Dispositif d'exposition, dispositif d'affichage à cristaux liquides ainsi que leur procédé de fabrication - Google Patents

Dispositif d'exposition, dispositif d'affichage à cristaux liquides ainsi que leur procédé de fabrication Download PDF

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Publication number
WO2012102104A1
WO2012102104A1 PCT/JP2012/050662 JP2012050662W WO2012102104A1 WO 2012102104 A1 WO2012102104 A1 WO 2012102104A1 JP 2012050662 W JP2012050662 W JP 2012050662W WO 2012102104 A1 WO2012102104 A1 WO 2012102104A1
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Prior art keywords
exposure
liquid crystal
light
substrate
crystal display
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PCT/JP2012/050662
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English (en)
Japanese (ja)
Inventor
井上　威一郎
宮地　弘一
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シャープ株式会社
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Publication of WO2012102104A1 publication Critical patent/WO2012102104A1/fr

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
    • G02F1/13378—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers by treatment of the surface, e.g. embossing, rubbing or light irradiation
    • G02F1/133788—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers by treatment of the surface, e.g. embossing, rubbing or light irradiation by light irradiation, e.g. linearly polarised light photo-polymerisation
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
    • G02F1/133753—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers with different alignment orientations or pretilt angles on a same surface, e.g. for grey scale or improved viewing angle

Definitions

  • the present invention relates to an exposure apparatus, a liquid crystal display device, and a manufacturing method thereof. More specifically, the present invention relates to an exposure apparatus suitably used for the photo-alignment treatment of the photo-alignment film, a liquid crystal display device including the photo-alignment film, and a method for manufacturing the liquid crystal display device.
  • the liquid crystal display device is a display device that can be reduced in weight, thickness, and power consumption, it is widely used for televisions, monitors for personal computers, monitors for portable terminals, and the like.
  • Such a liquid crystal display device usually controls the transmittance of light transmitted through the liquid crystal layer according to the inclination angle of the liquid crystal molecules that changes in accordance with the voltage applied between the pair of substrates (liquid crystal layer). Therefore, the liquid crystal display device has an angle dependency on the transmittance.
  • display defects such as a decrease in contrast and gradation inversion during halftone display may occur depending on the viewing angle (observation) direction. Therefore, in general, the liquid crystal display device has room for improvement in terms of improving viewing angle characteristics.
  • each pixel is divided into two or more regions having different tilt directions of liquid crystal molecules.
  • this technique when a voltage is applied to the liquid crystal layer, the liquid crystal molecules are inclined in different directions within the pixel, so that the viewing angle characteristics can be improved.
  • Each region having a different orientation direction is also called a domain, and orientation division is also called a multi-domain.
  • a multi-domain twisted nematic (TN) mode As the liquid crystal mode in which the alignment division is performed, in the horizontal alignment mode, a multi-domain twisted nematic (TN) mode, a multi-domain birefringence control (ECB) mode, a multi-domain optical compensation birefringence (OCB) (Optically Compensated Birefringence) mode and the like.
  • TN multi-domain twisted nematic
  • ECB multi-domain birefringence control
  • OCB optical compensation birefringence
  • Examples of the method for performing the alignment division include a rubbing method and a photo-alignment method (see, for example, Patent Documents 1 and 2).
  • a rubbing method a method of rubbing the alignment film in a state where the rubbing region and the non-rubbing region are separated by a patterned resist has been proposed.
  • the alignment treatment is performed by rubbing the surface of the alignment film with a cloth wound around a roller. Therefore, in the rubbing method, dust such as cloth hairs or scraped pieces may be generated, or switching elements may be damaged due to static electricity, characteristic shift, deterioration, etc., and there is room for further improvement. It was.
  • the photo-alignment method uses a photo-alignment film as the alignment film, and irradiates (exposures) light such as ultraviolet rays to the photo-alignment film, thereby generating an alignment regulating force in the alignment film and / or This is an alignment method for changing the alignment regulation direction. Therefore, the photo-alignment method can perform the alignment treatment of the alignment film in a non-contact manner, and can suppress the occurrence of dirt, dust, etc. during the alignment treatment. Further, by using a photomask at the time of exposure, light irradiation can be performed under different conditions on a desired region in the alignment film surface. Therefore, a domain having a desired design can be easily formed.
  • liquid crystal display devices In recent years, the size of liquid crystal display devices has been increasing, and liquid crystal televisions have rapidly expanded into the size range, which has been the main battlefield of plasma televisions, such as 40-inch to 60-inch.
  • This method includes an exposure step of dividing the substrate surface into two or more exposure regions and exposing the alignment film via a photomask for each exposure region, and the exposure step includes a part of the adjacent exposure region. The exposure is performed so as to overlap, and the photomask has a halftone portion corresponding to the overlapping exposure region.
  • the present invention has been made in view of the above situation, and an exposure apparatus and a liquid crystal display that can effectively suppress the generation of a seam on a display screen even when an alignment process is performed by a scanning exposure method.
  • An object of the present invention is to provide an apparatus and a method for manufacturing the same.
  • the inventors have conducted various studies on an exposure apparatus and a method for manufacturing a liquid crystal display apparatus that can effectively suppress the generation of seams on the display screen even when the alignment process is performed by a scanning exposure method. Attention was paid to the amount of irradiation in the overlappingly exposed part (exposure joint part).
  • the total irradiation amount of the exposure joint portion is preferably 50 to 200. %, More preferably 70-150%.
  • the total exposure dose of the exposure joint is set to 100%, but in the scanning exposure method, the seam is generated by setting the exposure dose to less than 100%.
  • the result of being effectively suppressed is surprising.
  • the present inventors speculate as follows. Unlike the normal exposure portion, the photo-alignment film is exposed twice at the exposure joint portion, and the edge of the exposure light passes at least four times in total. On the other hand, in the normal exposure portion, the edge of the exposure light usually passes twice in total. This difference in the number of passes of the exposure light edge is thought to affect some factor that gives the tilt angle of the photo-alignment film.
  • the first to third parts were set in the photo-alignment film on the substrate, the second part was provided between the first part and the third part, and the irradiation amount of the second part.
  • a second exposure is performed in which the portion is scanned and the second portion is scanned again, and the sum of the dose of the second portion by the first exposure and the dose of the second portion by the second exposure is calculated as follows.
  • An area to be exposed (exposure area) of the substrate includes the first part and the second part by setting smaller than the irradiation amount of the part and smaller than the irradiation amount of the third part. Scanning exposure can be performed by dividing into an area and an area including the second part and the third part. The region including the second portion can be used as an exposure joint (a portion exposed twice or more), and further, it is effective that a joint is generated on the display screen of a liquid crystal display device manufactured using this substrate. As a result, the inventors have found that the above problems can be solved brilliantly, and have reached the present invention.
  • one aspect of the present invention is an exposure apparatus that exposes the photo-alignment film while moving a substrate provided with the photo-alignment film on the surface thereof relative to exposure light
  • the exposure apparatus comprising: Performing a first exposure for exposing the first part and the second part of the photo-alignment film, and a second exposure for exposing the third part of the photo-alignment film and exposing the second part again,
  • the second part is between the first part and the third part
  • the first exposure is performed such that the dose of the second part is smaller than the dose of the first part
  • the second exposure is performed such that the dose of the second part is smaller than the dose of the third part, and the dose of the second part by the first exposure and by the second exposure.
  • the total dose of the second part is the dose of the first part
  • It said third portion said dose exposure apparatus either be set smaller than in (hereinafter, also referred to as an exposure apparatus of the present invention.) Is.
  • the configuration of the exposure apparatus of the present invention is not particularly limited by other components as long as such components are formed as essential, but a light source and a table on which the substrate is placed. And a moving means for moving the light source and / or the table in a predetermined direction.
  • Another aspect of the present invention is a method of manufacturing a liquid crystal display device including an exposure step of exposing the photo-alignment film while moving a substrate on which the photo-alignment film is provided relative to the exposure light.
  • a first exposure for exposing the first part and the second part of the photo-alignment film, a second exposure for exposing the third part of the photo-alignment film and exposing the second part again The first exposure is performed such that the dose of the second part is smaller than the dose of the first part, and the dose of the second part is greater than the dose of the third part.
  • the second exposure is performed so that the irradiation amount of the second part by the first exposure and the irradiation amount of the second part by the second exposure are the first part to be smaller.
  • any of the above-mentioned irradiation amount and the above-mentioned irradiation amount of the third portion Method of manufacturing a liquid crystal display device that is fence set (hereinafter, the method of manufacturing the liquid crystal display device of the present invention also referred to.).
  • the irradiation amount to the photo-alignment film can be calculated by the following formula.
  • (Irradiation amount) (Illuminance) ⁇ (Exposure light width) / (Scanning speed)
  • the illuminance means the illuminance of the exposure light on the photo-alignment film.
  • the width of the exposure light means the width (length) of the exposure light in the scanning (moving) direction on the photo-alignment film. Since the exposure light is applied to a planar area, it normally spreads in a direction orthogonal to the moving direction of the exposure light on the photo-alignment film.
  • the exposure light has a spread and the width of the exposure light is not constant depending on the location (for example, when the width of the exposure light decreases in a sine function within the region corresponding to the exposure joint), the exposure is performed.
  • the width of light means the width (length) at each location in the orthogonal direction.
  • the scanning speed means a relative movement (scanning) speed of the substrate with respect to the exposure light. Note that which of the exposure light and the substrate moves is not particularly limited, and either one of them or both of them may move.
  • the first exposure and the second exposure are performed so that the tilt directions of the liquid crystal molecules in the vicinity of the first to third parts are substantially the same. Is preferably implemented. Accordingly, each pixel (or each picture element) can be efficiently divided in orientation.
  • the tilt direction of the liquid crystal molecules near the first to third portions is preferably 5 ° or less, more preferably 2 ° or less.
  • the photo-alignment film has a direction of exposure light (may be an optical axis of exposure light) and / or a direction of movement of exposure light on the film, It is preferable to use a material (photo-alignment material) that changes the alignment direction of the liquid crystal according to the above.
  • the irradiation amount of the first part and / or the irradiation amount of the third part is 100%
  • the irradiation amount of the second part when the irradiation amount of the first part and / or the irradiation amount of the third part is 100%, the irradiation amount of the second part.
  • the minimum value of the total is more than 85.2%, preferably less than 100%, more preferably 91% or more and 96% or less.
  • the two ends of the exposure light pass once on the first portion and the end of the exposure light passes twice in total, and the third portion is exposed in the same manner. The end of the light passes twice, and the two ends of the exposure light pass twice on the second portion, and the end of the exposure light passes a total of four times.
  • the dose of the first portion and the dose of the third portion are usually set to be substantially the same, and when either dose is 100%, the difference between them is 5% or less. It is preferable that it is 2% or less.
  • the exposure apparatus of the present invention it is preferable that ultraviolet light is incident from an oblique direction with respect to the normal line of the surface of the substrate.
  • a desired pretilt angle can be expressed easily.
  • the expression of the pretilt angle depends on the movement direction of the light irradiation region, it is not necessary to make the exposure light incident obliquely on the surface of the substrate.
  • the incident light can be made substantially perpendicular to the surface of the substrate.
  • what is necessary is just to set the wavelength range of the said ultraviolet ray suitably with the material of the photo-alignment film
  • the ultraviolet light is incident from an oblique direction with respect to the normal line of the surface of the substrate.
  • the ultraviolet light is preferably polarized ultraviolet light.
  • anisotropic ultraviolet light By irradiating the photo-alignment film with anisotropic ultraviolet light in this manner, anisotropic rearrangement of molecules and / or chemical reaction in the photo-alignment film can be easily induced. Therefore, the orientation direction of the liquid crystal molecules in the vicinity of the photo-alignment film can be controlled more uniformly.
  • a dedicated point light source for example, a laser light source
  • the illuminance of the spot light (spot light) emitted from the point light source is adjusted.
  • the exposure apparatus of the present invention includes a photomask including a light shielding portion and a plurality of light transmitting portions, and exposes the photo-alignment film through the photomask.
  • the aperture ratio of the light transmitting part of the photomask can be easily changed by changing the size of the light transmitting part. Therefore, according to this embodiment, the amount of irradiation can be easily made different between the first portion, the third portion, and the second portion by using one kind of light source.
  • the photo-alignment film is exposed through a photomask including a light shielding portion and a plurality of light transmitting portions.
  • the light shielding part and the plurality of light transmitting parts are arranged in a stripe shape. Thereby, alignment processing can be efficiently performed on a substrate in which pixel regions (which may be pixel regions) are arranged in a matrix.
  • the longitudinal direction of the plurality of translucent portions and the relative direction of movement of the substrate are substantially the same.
  • all pixel regions or all picture element regions
  • the longitudinal direction of the plurality of light transmitting portions and the relative movement direction of the substrate are substantially the same, both positions do not necessarily coincide exactly, both positions Is preferably 5 ° (more preferably 2 °) or less.
  • the photomask is provided corresponding to the first portion and / or the plurality of first light transmitting portions provided corresponding to the third portion and the second portion.
  • a plurality of second light-transmitting portions, and the aperture ratio of each second light-transmitting portion is smaller than the aperture ratio of each first light-transmitting portion.
  • the aperture ratio means the ratio (percentage) of the area of the light transmitting part to the area of an arbitrary light transmitting part (usually the light transmitting part having the largest area).
  • the aperture ratio of the plurality of second light-transmitting portions decreases as the distance from the plurality of first light-transmitting portions increases. According to the said form (A), it can suppress more effectively that a joint line is visually recognized.
  • Preferred forms in the above form (A) include the following forms (A-1) and (A-2).
  • the change in the aperture ratio of the plurality of second light transmitting parts is represented by a linear function or a trigonometric function. According to the above form (A-1), it is possible to prevent a discontinuous step from occurring in the change in the aperture ratio of the second light transmitting part.
  • the change in the aperture ratio is represented by a trigonometric function
  • the differential coefficient of the change in the aperture ratio is substantially zero at the end on the first light transmitting portion side and the end on the opposite side. The seam can be particularly effectively suppressed from being visually recognized.
  • the lengths (lengths in the longitudinal direction) of the plurality of second light-transmitting portions are shortened as the distance from the plurality of first light-transmitting portions is increased.
  • the total irradiation amount of the second portion can be easily controlled.
  • a proximity gap is provided between the photomask and the substrate.
  • the exposure apparatus of the present invention preferably includes an image pickup unit that reads the pattern of the substrate.
  • an image pickup unit that reads the pattern of the substrate.
  • the exposure apparatus of the present invention controls the relative movement direction of the substrate with respect to the exposure light while reading the pattern of the substrate.
  • the pattern of the substrate is not an essential component, and there may be no pattern on the substrate, but usually the pattern is formed on the substrate.
  • a specific example of the pattern is not particularly limited, but a dot-like or linear member formed periodically or continuously in the relative movement direction of the substrate is preferable, and in particular, a bus line (for example, a source bus line) , Gate bus line) and black matrix are preferable.
  • the manufacturing method of the liquid crystal display device of the present invention preferably includes a step of forming a vertical alignment type liquid crystal layer. Thereby, a liquid crystal display device in a vertical alignment mode can be realized.
  • the method for producing a liquid crystal display device of the present invention preferably includes a step of forming a liquid crystal layer containing a liquid crystal material having a negative dielectric anisotropy. Accordingly, in the liquid crystal display device in the vertical alignment mode, the liquid crystal layer can be driven efficiently, so that the transmittance can be increased.
  • the projection direction (or the exposure direction) of the two substrates exposed in the exposure process onto the surface of the substrate in the irradiation direction of the exposure light may be substantially orthogonal to each other.
  • a step of bonding may be included.
  • a liquid crystal display device of TN mode, VATN mode, multi-domain TN mode or multi-domain VATN mode can be realized.
  • the fact that the projection directions are substantially orthogonal to each other does not necessarily mean that the angle formed by the projection directions is strictly 90 °, and the angle formed by the projection directions is 90 ° ⁇ 10 ° (more preferably 90 ° ⁇ 5). °) is preferably within the range.
  • the substrate when the substrate is viewed in plan, two regions exposed in antiparallel directions to each other are formed in each pixel (may be in each pixel). It is preferable to include a step of exposing the photo-alignment film.
  • wide-angle display such as multi-domain TN mode, multi-domain ECB mode, multi-domain VAECB mode, multi-domain VAHAN (Vertical Alignment Hybrid-aligned Nematic) mode, multi-domain VATN (Vertical Alignment Twisted Nematic) liquid crystal display, etc.
  • the antiparallel direction does not necessarily mean that the two directions are strictly opposite and parallel, and the angle formed by both directions is preferably 175 ° (more preferably 178 °) or more and 180 ° or less. .
  • Still another aspect of the present invention is a liquid crystal display device (hereinafter, also referred to as a liquid crystal display device of the present invention) manufactured using the exposure apparatus of the present invention or the liquid crystal display device manufacturing method of the present invention. .
  • the liquid crystal display device of the present invention is preferably driven by active matrix, but may be driven simply.
  • the liquid crystal display device of the present invention is preferably driven in the VATN mode.
  • a VATN mode liquid crystal display device includes a pair of substrates, a liquid crystal layer containing a nematic liquid crystal, and a pair of vertical alignment films provided on the respective substrates. The directions of the alignment treatment applied to these vertical alignment films are substantially orthogonal to each other, and the nematic liquid crystal is vertically and twist-aligned when no voltage is applied.
  • the liquid crystal display device of the present invention preferably has 2 or more domains, preferably 4 or less domains, and more preferably 4 domains.
  • a liquid crystal display device excellent in viewing angle characteristics can be realized while suppressing the complexity of the manufacturing process.
  • a wide viewing angle can be obtained in any of four directions orthogonal to each other, for example, four directions of up, down, left, and right.
  • the viewing angle characteristics in any of the four directions orthogonal to each other can be made substantially the same. That is, it is possible to realize viewing angle characteristics with excellent symmetry. Therefore, a liquid crystal display device with small viewing angle dependency can be realized.
  • the arrangement form of the domains in the case where the orientation is divided into four domains is not particularly limited, and examples thereof include a matrix shape and a stripe shape such as an eye shape.
  • an exposure apparatus it is possible to realize an exposure apparatus, a liquid crystal display apparatus, and a manufacturing method thereof that can suppress the generation of a seam on a display screen even when alignment processing is performed by a scanning exposure method.
  • FIG. 3 is a schematic plan view of a mother glass substrate using the method for manufacturing a liquid crystal display device according to Embodiment 1.
  • FIG. 3 is a perspective view schematically showing a picture element region of a mother glass substrate (array substrate) using the method for manufacturing a liquid crystal display device according to Embodiment 1.
  • FIG. 3 is a perspective view schematically showing a picture element region of a mother glass substrate (color filter substrate) using the method for manufacturing a liquid crystal display device according to Embodiment 1.
  • FIG. FIG. 2 is a schematic diagram showing a main part of an exposure apparatus according to Embodiment 1, viewed from above.
  • FIG. 2 is a schematic view showing a main part of an exposure apparatus according to Embodiment 1, viewed from the side.
  • FIG. 4 is a perspective view schematically showing a photomask using the method for manufacturing a liquid crystal display device according to Embodiment 1.
  • FIG. 4 is a plan view schematically showing a photomask using the method for manufacturing the liquid crystal display device according to Embodiment 1.
  • FIG. 3 is a perspective view schematically showing a photo-alignment process for a mother glass substrate using the method for manufacturing a liquid crystal display device according to Embodiment 1. It is a graph which shows the relationship between the irradiation amount to a photo-alignment film
  • the relationship between dimensions and positions of the photomask for the array substrate and the pattern formed on the mother glass substrate for the array substrate is shown. It is the figure which showed typically the exposure process in the manufacturing method of the liquid crystal display device which concerns on Embodiment 1, and is the figure seen from the side. It is the figure which showed typically the exposure process in the manufacturing method of the liquid crystal display device which concerns on Embodiment 1, and is the figure seen from upper direction. It is the top view which showed typically the mother glass substrate for array substrates using the manufacturing method of the liquid crystal display device which concerns on Embodiment 1, and shows the state after an exposure process.
  • 5 is a plan view schematically showing a pattern formed on the photomask and an arrangement position of the photomask in the exposure process for the array substrate photomask used in the method for manufacturing the liquid crystal display device according to the first embodiment.
  • 6 is a graph showing irradiation amounts in a normal exposure portion and an exposure joint portion in the method for manufacturing a liquid crystal display device according to the first embodiment. It is the top view which showed typically the relationship of the various directions in each pixel about the board
  • FIG. 1 is a cross-sectional view schematically showing a liquid crystal display panel and a liquid crystal display device according to Embodiment 1.
  • FIG. FIG. 3 is a diagram schematically illustrating the alignment direction of liquid crystal molecules in each pixel in the liquid crystal display panel according to Embodiment 1. The result of having simulated the brightness in one picture element in the liquid crystal display panel which concerns on Embodiment 1 is shown. It is the figure which showed typically the exposure process in panel trial manufacture, and is the figure seen from upper direction.
  • FIG. 5 is a schematic plan view for explaining a method for visually evaluating the appearance of exposed joints of prototype panels 1 to 3; 6 is an image showing the result of measuring the luminance unevenness of the prototype panels 1 to 3; FIG. 6 is a diagram schematically showing the orientation direction of liquid crystal molecules in each picture element in a normal exposure portion for prototype panels 1 to 3; FIG. 5 is a diagram schematically showing the orientation direction of liquid crystal molecules in each picture element at an exposure joint for prototype panels 1 to 3; 12 is a plan view schematically showing prototype panels 4 to 13.
  • FIG. 10 is a schematic perspective view for explaining a method for visually evaluating the appearance of exposed joints of prototype panels 4 to 13;
  • FIG. 6 is a diagram schematically showing the orientation direction of liquid crystal molecules in each picture element in the normal exposure portion for prototype panels 4 to 13;
  • FIG. 6 is a diagram schematically showing the orientation direction of liquid crystal molecules in each picture element in an exposure joint for prototype panels 4-13. It is the figure which showed typically the exposure process in the manufacturing method of the liquid crystal display device which concerns on Embodiment 2, and is the figure seen from upper direction.
  • FIG. 6 is a plan view schematically showing a pattern formed on a photomask and an arrangement position of the photomask in an exposure process for a photomask used in the method for manufacturing a liquid crystal display device according to Embodiment 2.
  • FIG. 35 is a plan view schematically showing the relationship between various directions in each pixel for the substrate after the exposure process shown in FIGS. 32 and 34.
  • FIG. 10 is a schematic plan view showing a main part of an exposure apparatus according to Embodiment 3.
  • FIG. 6 is a diagram schematically showing the alignment direction of liquid crystal molecules in each pixel in the liquid crystal display panel of Modification 1 according to Embodiment 1.
  • FIG. 6 is a diagram schematically showing the alignment direction of liquid crystal molecules in each picture element of a liquid crystal display panel of a second modification according to the first embodiment. It is the figure which showed typically the orientation direction of the liquid crystal molecule in each pixel about the liquid crystal display panel of the modification 3 which concerns on Embodiment 1.
  • Embodiment 1 Below, the manufacturing method of the liquid crystal display device which concerns on Embodiment 1 is demonstrated.
  • the method for manufacturing a liquid crystal display device according to the present embodiment is applied to a method for manufacturing a liquid crystal display device including an exposure process for performing a photo-alignment process.
  • the manufacturing method of the liquid crystal display device according to the present embodiment can be applied to liquid crystal display devices of various display modes, and in particular, a liquid crystal display device of a twisted nematic vertical alignment (Vertical Aligned Twisted Nematic (VATN)) mode. It is suitable for.
  • VATN twisted nematic vertical alignment
  • a pair of mother glass substrates 10 before alignment film formation are prepared by a general method. From each mother glass substrate 10, for example, a plurality of (for example, six) array substrates or color filter substrates are obtained. In this embodiment, a single array substrate or a single color filter substrate may be used. Each mother glass substrate 10 is provided with a plurality of panel regions 11 corresponding to the obtained array substrate or color filter substrate.
  • source bus lines 12 and gate bus lines 13 that intersect with each other are formed in a mesh shape, and the source bus lines 12 and the gate bus lines 13 A thin film transistor 14 and a pixel electrode 15 are formed in each partitioned pixel region. Then, in each of the pixel regions, assuming two regions A1 and A2 formed by being substantially divided between the source bus lines 12 on both sides (line CL1 in the drawing), The polarized ultraviolet rays are irradiated to the regions A1 and A2 from a direction inclined by a predetermined angle ⁇ with respect to the normal line of the surface of the substrate 10.
  • the direction of irradiation of polarized ultraviolet light with respect to each region is such that when the optical axis of the polarized ultraviolet light to be irradiated is projected onto the surface of the substrate 10, the projected optical axes are parallel to the source bus line 12 and are different from each other by 180 °. Orient.
  • a black matrix 16 is formed in a mesh pattern in the panel region 11 of the other mother glass substrate, and a color filter 17 is formed in each pixel region partitioned by the black matrix 16.
  • a common electrode (not shown) is formed on the black matrix 16 and the color filter 17.
  • two regions B1 and B2 formed by being divided into two substantially at the middle (line CL2 in the figure) of two sides parallel to the gate bus line 13 when bonded to the array substrate.
  • polarized ultraviolet rays are irradiated from the direction inclined by a predetermined angle ⁇ with respect to the normal of the surface of the substrate 10 to the regions B1 and B2.
  • the direction of irradiation of polarized ultraviolet light with respect to each region is such that when the optical axis of the polarized ultraviolet light to be irradiated is projected onto the surface of the substrate 10, these projected optical axes are parallel to the gate bus line 13 and 180 ° to each other. Use different orientations.
  • the liquid crystal display device according to this embodiment is a monochrome display liquid crystal display device. Also good.
  • the picture element may be read as a pixel. Note that a picture element is an element constituting a pixel and is synonymous with a sub-pixel.
  • the photo-alignment film material is not particularly limited, and examples thereof include a resin containing a photosensitive group. More specifically, a 4-chalcone group (the following chemical formula (1)), a 4′-chalcone group (the following chemical formula (2)), a coumarin group (the following chemical formula (3)), and a cinnamoyl group (the following chemical formula (4)).
  • a polyimide containing a photosensitive group such as is suitable.
  • the photosensitive groups of the following chemical formulas (1) to (4) are those that cause a crosslinking reaction (including a dimerization reaction), an isomerization reaction, a photoreorientation, etc. by irradiation with light (preferably ultraviolet rays). Accordingly, the variation in the pretilt angle in the alignment film plane can be effectively reduced as compared with the photodecomposition type photo-alignment film material.
  • the photosensitive groups represented by the following chemical formulas (1) to (4) include structures in which a substituent is bonded to the benzene ring.
  • the photo-alignment film material is more preferably a polyimide containing a cinnamate group.
  • the firing temperature, firing time, and film thickness of the photo-alignment film are not particularly limited and may be set as appropriate.
  • a photo-alignment film material that reacts with light and generates a pretilt angle of liquid crystal molecules in the light irradiation direction is used as the alignment film material.
  • the photo-alignment method disclosed in Non-Patent Document 1 As described above, a photo-alignment film material that can define the pretilt direction depending on the moving direction of the light irradiation region may be used. In this case, light does not need to be incident on the substrate from an oblique direction, and can be incident substantially perpendicular to the substrate.
  • the exposure apparatus 30 is a one-stage scanning exposure apparatus, and an exposure stage 32 including a plurality of exposure heads 31 and a mother glass substrate 10 are placed and moved in a predetermined direction. And a table 33 to be operated.
  • the table 33 also functions as a moving unit.
  • the exposure apparatus 30 may include a moving unit that moves the exposure stage 32, or does not function as a moving unit, and includes a table on which the mother glass substrate 10 is placed and a moving unit that moves the exposure stage 32. You may prepare.
  • the plurality of exposure heads 31 are arranged at intervals in a direction b orthogonal to the moving direction (scanning direction) a of the substrate 10. Each exposure head 31 is supported so as to be movable in a direction b in a plane parallel to the irradiated surface of the substrate 10.
  • Each exposure head 31 includes an ultraviolet light source 34 that emits ultraviolet light, a photomask 50, and an optical member (not shown) such as a polarizing filter and an optical lens provided between the light source 34 and the photomask 50.
  • the surface of the substrate 10 can be irradiated with polarized ultraviolet rays through the mask 50 at a predetermined irradiation angle (an angle between the normal direction of the surface of the substrate 10 and the irradiation direction of the exposure light, for example, 40 °).
  • the Each optical member optically converts the ultraviolet rays emitted from the light source 34 into desired exposure light.
  • the light source 34 may be appropriately selected according to the irradiation target, and may be a light source that emits visible light.
  • Each exposure head 31 includes an imaging unit 35, a storage unit, a collation unit, and a mask moving unit.
  • the imaging means 35 can photograph the surface of the substrate 10 and can read a pattern of the substrate 10 (for example, the source bus line 12, the gate bus line 13, the black matrix 16, etc.).
  • a camera such as a CCD camera can be applied.
  • the storage means can store a reference image serving as a reference for exposure alignment.
  • the collating unit compares and collates the image captured by the image capturing unit 35 with the reference image, and calculates a difference between the position where the exposure is actually performed and the position where the exposure is to be performed.
  • the mask moving means corrects the position and angle of the mask 50 based on the calculation result of the deviation by the collating means.
  • the scanning exposure can be performed while reading the pattern of the substrate 10 and controlling the relative movement direction and position of the substrate 10 with respect to the exposure light with high accuracy.
  • the collating means can similarly correct the position and angle of the mask 50 by a method of comparing and collating the result of imaging the substrate 10 and the result of imaging the mask 50 instead of using the reference image.
  • the mask 50 is disposed so that the surface thereof is substantially parallel to the irradiated surface of the substrate 10, and a proximity gap 41 is formed between the mask 50 and the irradiated surface of the substrate 10, that is, the surface of the photo-alignment film. Is provided.
  • the mask 50 is, for example, a plate-like member, and as shown in FIG. 6, a transparent substrate formed using quartz glass or the like, and a predetermined pattern (preferably a stripe pattern) on the surface of the transparent substrate.
  • the light-shielding portion 52 and the plurality of light-transmitting portions 51 are formed.
  • Each translucent portion 51 has a longitudinal shape, and the plurality of translucent portions 51 are arranged in a direction b orthogonal to the moving direction a of the substrate 10 at a predetermined pitch.
  • the mask 50 has a central region 53 and an overlap region 54 as shown in FIG.
  • the length of the light transmitting portion 56 (corresponding to the second light transmitting portion) provided in the overlap region 54 gradually decreases as the distance from the central region 53 increases.
  • the aperture ratio of the light transmitting portion 56 provided in the overlap region 54 is smaller than the aperture ratio of the light transmitting portion 55 (corresponding to the first light transmitting portion) provided in the central region 53. It has become.
  • the translucent part 56 farther from the translucent part 55 has a shorter length and a smaller aperture ratio.
  • the material of the light transmission part 51 will not be specifically limited if light (for example, polarized ultraviolet rays) can be permeate
  • the translucent part 51 may be, for example, an opening that penetrates the mask 50.
  • the illuminance means the illuminance of the exposure light on the photo-alignment film. Therefore, if the illuminance and the moving speed V are kept constant, the irradiation amount is proportional to the length Y of the light transmitting part.
  • FIG. 9 is a graph showing the relationship between the irradiation amount to the photo-alignment film and the pretilt angle of the liquid crystal molecules.
  • the pretilt angle of the liquid crystal molecules in the vicinity of the alignment film becomes smaller as the irradiation amount to the photo-alignment film becomes larger.
  • the pretilt angle depends on the dose, and the dose is a very important factor in controlling the pretilt angle. Further, as described in Patent Document 4, in the VATN mode, it is extremely important to control the pretilt angle with high accuracy.
  • the area to be exposed of the mother glass substrate 10 is divided into a plurality of areas and exposed (photo-alignment treatment).
  • the mother glass substrate 10a for an array substrate will be described.
  • the array substrate photomask 60 is a substantially rectangular plate-shaped member.
  • a plurality of slit-like light transmitting portions 61 through which polarized ultraviolet rays can pass are formed in parallel at a predetermined pitch Px.
  • the pitch Px is set equal to the pitch of the source bus line 12.
  • the dimension Lx in the pitch direction of the translucent portion 61 is set to a dimension that is approximately 1 ⁇ 2 of the pitch of the source bus line 12.
  • the mask 60 has a central region and an overlap region, and the aperture ratio of the light transmissive portion provided in the overlap region is smaller than the aperture ratio of the light transmissive portion provided in the central region. .
  • the substrate 10a and the table are moved from the end of the photo-alignment film 19 provided on the surface of the substrate 10a through the photomask 60 while moving the substrate 10a and the table at a constant speed in the + x-axis direction.
  • (1st exposure (1)) the substrate 10 a is moved so that the source bus line 12 is along the longitudinal direction of the light transmitting portion 61 of the photomask 60.
  • the irradiation amount of the area A1 in the area 22 is within the area 21. It becomes smaller than the irradiation amount of area
  • the substrate 10a and the table are moved in the ⁇ x-axis direction and returned to the position before the exposure stage 32. Further, each exposure head 31 is moved in the + y-axis direction by one exposure head. As a result, the central region of the photomask 60 is disposed corresponding to the region 23, and the overlap region of the photomask 60 is disposed corresponding to the region 22.
  • the substrate 10a and the table are moved from the end of the photo-alignment film 19 provided on the surface of the substrate 10a through the photomask 60 while moving the substrate 10a and the table at a constant speed in the + x-axis direction.
  • (1st exposure (2)) the substrate 10 a is moved so that the source bus line 12 is along the longitudinal direction of the light transmitting portion 61 of the photomask 60.
  • the area A1 of the picture element area is exposed in the area 23 through which the central area of the photomask 60 has passed.
  • the region A1 is exposed again.
  • 1st exposure (1) and 1st exposure (2) irradiate the same area
  • the sum of the irradiation amount of the region A1 by the first exposure (1) in the region 22 and the irradiation amount of the region A1 by the first exposure (2) in the region 22 is the first exposure (1 in the region 21).
  • portions of the photo-alignment film 19 that are in the region A1, the region 21, the region 22, and the region 23 correspond to the first portion, the second portion, and the third portion, respectively.
  • the substrate 10a and the table are moved in the ⁇ x-axis direction and returned to the position before the exposure stage 32. Further, the substrate 10a is rotated 180 ° in the plane and placed on the table. Further, each exposure head 31 is moved in the ⁇ y-axis direction by one exposure head. As a result, the photomask 60 is disposed at substantially the same position as the position during the first exposure (1). However, the photomask 60 is arranged at a position shifted in the y-axis direction by half the pitch of the source bus lines 12 as compared to the position at the time of the first exposure (1).
  • the substrate 10a and the table are moved from the end of the photo-alignment film 19 provided on the surface of the substrate 10a through the photomask 60 while moving the substrate 10a and the table at a constant speed in the + x-axis direction.
  • (2nd exposure (1)) At this time, the substrate 10 a is moved so that the source bus line 12 is along the longitudinal direction of the light transmitting portion 61 of the photomask 60.
  • the second exposure (1) in the region 21 through which the central region of the photomask 60 has passed and in the region 22 through which the overlap region of the photomask 60 has passed, the remaining pixel region shown in FIG. This area A2 is exposed.
  • the irradiation amount of the region A2 in the region 22 is smaller than the irradiation amount of the region A2 in the region 21. Further, the area A2 of the picture element area in the area 23 where the light transmitting portion 61 of the photomask 60 has not passed is not exposed at this stage.
  • the substrate 10a and the table are moved in the ⁇ x-axis direction and returned to the position before the exposure stage 32. Further, each exposure head 31 is moved in the + y-axis direction by one exposure head. As a result, the central region of the photomask 60 is disposed corresponding to the region 23, and the overlap region of the photomask 60 is disposed corresponding to the region 22. And the photomask 60 is arrange
  • the substrate 10a and the table are moved from the end of the photo-alignment film 19 provided on the surface of the substrate 10a through the photomask 60 while moving the substrate 10a and the table at a constant speed in the + x-axis direction.
  • (2nd exposure (2)) At this time, the substrate 10 a is moved so that the source bus line 12 is along the longitudinal direction of the light transmitting portion 61 of the photomask 60.
  • the second exposure (2) the area A2 of the picture element area is exposed in the area 23 through which the central area of the photomask 60 has passed. Further, in the region 22 where the overlap region of the photomask 60 has passed, the region A2 of the pixel region is exposed again.
  • 2nd exposure (1) and 2nd exposure (2) irradiate the same area
  • the sum of the irradiation amount of the region A2 by the second exposure (1) in the region 22 and the irradiation amount of the region A2 by the second exposure (2) in the region 22 is the second exposure (1 in the region 21).
  • portions of the photo-alignment film 19 that are in the region A2 in the region 21, the region 22, and the region 23 correspond to the first portion, the second portion, and the third portion, respectively.
  • the substrate 10a is exposed over the entire surface, and the photo-alignment processing of the substrate 10a is completed.
  • the substrate 10a is formed with the normal exposure part 24 exposed only once and the exposure joint part 25 exposed twice.
  • a portion of the photo-alignment film 19 that is normally in the exposure portion 24 corresponds to the first and third portions, and is a portion of the photo-alignment film 19 and in the exposure joint portion 25.
  • the part located at corresponds to the second part.
  • FIG. 14 is a plan view schematically showing a pattern formed on the photomask 60 and an arrangement location of the photomask 60 in the exposure process.
  • the photomask 60 has a central region 63 and an overlap region 64.
  • the width of the overlap region 64 is 10 to 80 mm (preferably 30 to 60 mm, for example, 45 mm).
  • the length y of the translucent part 66 (corresponding to the second translucent part) provided in the overlap region 64 is equal to the translucent part 65 (corresponding to the first translucent part) provided in the central region 63. ) Is smaller than the length y0.
  • the length y of the light transmitting portion 66 is gradually shortened, whereby the aperture ratio of the light transmitting portion 66 is gradually decreased. Therefore, the portion exposed through the relatively long light transmitting portion 66 in the first exposure (1) or the second exposure (1) is relatively transparent in the first exposure (2) or the second exposure (2). The light is exposed through the light part 66.
  • the length (aperture ratio) of the translucent portion 66 preferably changes according to a linear function or a trigonometric function. In the exposure joint 25, the first exposure (1) and the first exposure (2) are the same, and the second exposure (1) and the second exposure (2) are the same part (for example, the same half on the same side of the picture element). ) Is designed to be exposed.
  • the method of gradually decreasing the aperture ratio of the light transmitting portion 66 as the distance from the central region 63 is not particularly limited, and for example, the method described in Patent Document 3 can be appropriately employed. Alternatively, a method may be used in which the translucent portion 66 is shaded while the length of the translucent portion 66 is kept constant, and the density of the shade is gradually increased as the distance from the central region 63 increases.
  • FIG. 15 is a graph showing the irradiation amounts in the normal exposure part 24 and the exposure joint part 25.
  • the dose E0 of the normal exposure unit 24 is proportional to the length y0 of the translucent unit 65 provided in the central region 63, and is constant regardless of the position x. Since the irradiation amount E of the exposure joint portion 25 is proportional to the length y of the light transmitting portion 66 provided in the overlap region 64, it gradually decreases as the distance from the normal exposure portion 24 increases.
  • the total irradiation amount of the exposure joint portion 25 is the sum of the irradiation amount by the first exposure (1) and the irradiation amount by the first exposure (2), or , The sum of the dose by the second exposure (1) and the dose by the second exposure (2). That is, the total dose of the exposure joint portion 25 depends on the dose of each exposure, and may have a maximum value E max or a minimum value E min .
  • the photomask 60 is designed so that the total irradiation amount of the exposure joint portion 25 is smaller than the irradiation amount E0 of the normal exposure portion 24. Thereby, it is possible to effectively suppress the generation of a seam between adjacent normal exposure portions 24.
  • FIG. 16 is a plan view schematically showing the relationship between various directions in each pixel for the substrate after the exposure process shown in FIGS.
  • the substrate in the irradiation direction of polarized ultraviolet rays (or the direction of the optical axis may be used) between the first exposure (1) and (2) and the second exposure (1) and (2).
  • Projection directions A onto the planes are parallel to each other and differ by 180 °.
  • the movement direction B of the substrate between the first exposures (1) and (2) and the second exposures (1) and (2) is parallel to each other and is different by 180 °.
  • the tilt directions C of the liquid crystal molecules in the vicinity of the photo-alignment film are parallel to each other and different from each other by 180 °.
  • the tilt direction means the direction of projection of the liquid crystal molecules 4b in the vicinity of the photo-alignment film onto the surface of the substrate 10 as shown in FIG.
  • the tilt angle ⁇ means an angle formed between the long axis of the liquid crystal molecules 4b and the surface of the substrate 10.
  • the relationship between the projection direction A and the substrate movement direction B is the same for all exposures (first exposure (1), (2) and second exposure (1), (2)). Are the same.
  • the color filter substrate photomask 70 has substantially the same configuration as the array substrate photomask 60. That is, a plurality of slit-like light transmitting portions 71 through which polarized ultraviolet rays can pass are formed in parallel with a predetermined pitch Py.
  • the pitch Py is set to be equal to the pitch of the black matrix 16 (here, the pitch of the side parallel to the gate bus line 13 of the array substrate when superimposed on the array substrate).
  • the dimension Ly in the pitch direction of the translucent portion 71 is set to a dimension that is approximately 1 ⁇ 2 of the pitch of the black matrix 16.
  • the mask 70 has a central region and an overlap region, and the aperture ratio of the light transmissive portion provided in the overlap region is smaller than the aperture ratio of the light transmissive portion provided in the central region. .
  • the exposure mode for the mother glass substrate 10b is substantially the same as the exposure mode for the mother glass substrate 10a for an array substrate, except that the orientation of the substrate is different by 90 °, and therefore detailed description thereof is omitted.
  • the region B1 is exposed by the first exposure (1) and / or the first exposure (2)
  • the region B2 is exposed by the second exposure (1) and / or the second exposure (2).
  • the substrates 10a and 10b are divided into panel regions, and the array substrate 1 and the color filter substrate 2 are produced. And the bonding process of the board
  • a sealing material is applied to the frame region of one substrate.
  • plastic beads having a particle diameter of 4 ⁇ m are sprayed on a substrate coated with a sealing material, and then both substrates are bonded together.
  • a nematic liquid crystal material having a negative dielectric anisotropy is sealed between the substrates 1 and 2 to form a liquid crystal layer 3, thereby completing a liquid crystal display panel.
  • the following process may be employed for manufacturing the liquid crystal display panel.
  • a sealing material is applied to the frame region of each panel region 11 for one of the substrates 10a and 10b.
  • a nematic liquid crystal material having a negative dielectric anisotropy is dropped onto the other substrate surface at a predetermined pitch.
  • both substrates thus treated are bonded together in a vacuum environment.
  • the cell thickness is controlled by a photo spacer previously set on the mother glass substrate 10b for the color filter substrate, and is set to 4 ⁇ m, for example.
  • the sealing material is cured and divided into panels to complete a liquid crystal display panel. *
  • the liquid crystal molecules 4 in the liquid crystal layer 3 are aligned in a direction substantially perpendicular to the surface of the photo-alignment film 19 when a driving voltage is not applied to the liquid crystal layer 3 (when no voltage is applied).
  • the liquid crystal molecules 4 are aligned with a slight inclination of about 0.1 ° to several degrees with respect to the normal direction of the surface of the photo-alignment film 19 at this time. That is, the liquid crystal molecules 4 are aligned by the optical alignment 19 so as to have a slight pretilt angle.
  • the pretilt angle means the tilt angle when no voltage is applied.
  • FIG. 20 is a diagram schematically showing the alignment direction of the liquid crystal molecules in each picture element.
  • the liquid crystal display panel is configured by bonding the array substrate and the color filter substrate subjected to the alignment treatment as described above, the liquid crystal molecules are directed to the orientation treatment applied to each region of each substrate, that is, irradiated with polarized ultraviolet rays. Orient according to direction.
  • the tilt direction of the liquid crystal molecules in the vicinity of the array substrate dotted arrow in FIG. 20
  • the tilt direction of the liquid crystal molecules in the vicinity of the color filter substrate solid arrow in FIG. 20
  • four domains D1 to D4 having different orientation directions of liquid crystal molecules are formed.
  • the liquid crystal molecules are twisted and aligned by approximately 90 °.
  • the liquid crystal molecules are tilted in an orientation that divides the tilt directions of both substrates into two equal parts.
  • the liquid crystal molecules 4a located equidistant from the surfaces of both substrates are tilted to 45 ° azimuth, 135 ° azimuth, 225 ° azimuth, or 315 ° azimuth when a voltage is applied.
  • the liquid crystal molecules 4a are inclined in a direction substantially parallel to the surfaces of both substrates.
  • the two retardation plates 7 a and 7 b and the two polarizing plates 6 a and 6 b are attached to the outside of the substrates 1 and 2.
  • the retardation plates 7a and 7b need not be installed, but are preferably installed from the viewpoint of realizing a wide viewing angle. Further, only one of the phase difference plates 7a and 7b may be arranged.
  • the polarizing plates 6a and 6b are arranged in crossed Nicols. One of the polarizing plates 6a and 6b is arranged so that the absorption axis thereof is parallel to the tilt direction (dotted line arrow in FIG. 20) of the liquid crystal molecules in the vicinity of the array substrate, and the other has the absorption axis of the color filter.
  • the liquid crystal molecules in the vicinity of the substrate are arranged so as to be parallel to the tilt direction (solid arrow in FIG. 20).
  • the liquid crystal display panel of the present embodiment can realize a good black display (normally black mode).
  • the liquid crystal display panel of the present embodiment has four domains, and the liquid crystal molecules in the four domains respond to four different directions, so that display characteristics almost independent of the viewing angle direction can be exhibited.
  • FIG. 21 shows the result of simulating the brightness of one picture element in the liquid crystal display panel according to the first embodiment.
  • the directions in which the liquid crystal molecules 4a are tilted in the four domains D1 to D4 form an angle of about 90 °. Therefore, at the boundary between different domains, the liquid crystal molecules 4a are aligned so as to continuously connect the liquid crystal molecules 4a tilted in different directions. Further, the direction in which the liquid crystal molecules 4a fall in the four domains D1 to D4 differs by about 45 ° with respect to the absorption axis directions of the polarizing plates 6a and 6b.
  • the orientation direction of the liquid crystal molecules 4a at the boundary between different domains is an orientation that is substantially the same or substantially orthogonal to the absorption axis direction of the polarizing plate 6a or the absorption axis direction of the polarizing plate 6b. Accordingly, retardation (phase difference) due to liquid crystal molecules does not occur in the polarized light transmitted through the lower polarizing plate 6a at the boundary between different domains. That is, the polarized light transmitted through the lower polarizing plate 6a is not affected at all by the liquid crystal layer 3, and the polarized light transmitted through the lower polarizing plate 6a cannot be transmitted through the upper polarizing plate 6b. As a result, a dark line having a low luminance, that is, a dark line, is generated at the boundary between different domains.
  • FIGS. 37 to 39 show a case where the alignment direction of the liquid crystal molecules is set so that a reverse dark line is generated when the panel is observed from the color filter substrate side.
  • the direction may be set as shown in FIGS. 37 to 39, the dotted arrow indicates the tilt direction of the liquid crystal molecules near the array substrate, and the solid arrow indicates the tilt direction of the liquid crystal molecules near the color filter substrate.
  • a saddle-shaped dark line is generated in the case shown in FIG. 37
  • an 8-shaped dark line is generated in the case shown in FIG. 38, and vice versa in the case shown in FIG.
  • a dark line with a letter shape is generated.
  • one picture element region may be divided into two regions, and four domains may be formed in each region.
  • Embodiment 1 can be completed through a general module manufacturing process.
  • the liquid crystal display device of this embodiment is a four-domain VATN mode.
  • each of the substrates 10a and 10b is irradiated twice, and four domains can be formed by a total of four irradiations. Therefore, it is possible to reduce the number of apparatuses and shorten the alignment processing time (shorten the tact time). Further, dividing one picture element into four domains is a preferable form from the viewpoint of realizing a wide viewing angle of the liquid crystal display device. Further, the photomask for forming the alignment control structure such as ribs (protrusions) required in the liquid crystal mode having the alignment control structure such as the conventional MVA mode, that is, the photolithography process can be reduced.
  • the manufacturing process can be simplified.
  • the viewing angle characteristics in the other direction can be increased, although the viewing angle in the other direction can be widened. Can not.
  • the number of domains may be increased to five or more, it is not preferable because the process becomes complicated and the processing time becomes long. Furthermore, it has been found that there is practically no difference in viewing angle characteristics between four domains and more domains.
  • Examples of materials that can be used in the present embodiment and conditions in an applicable manufacturing process include the following. However, materials and conditions that can be used in the present embodiment are not limited to the following.
  • Pretilt angle 85 ⁇ 89.9 ° ⁇
  • Cell thickness 2-5 ⁇ m ⁇
  • Irradiation energy density 0.01 to 5 J / cm 2 ⁇
  • Proximity gap 100-300 ⁇ m ⁇
  • Light source low-pressure mercury lamp, high-pressure mercury lamp, deuterium lamp, metal halide lamp, argon resonance lamp, xenon lamp, excimer laser, ultraviolet extinction ratio (degree of polarization): 1: 1 to 60: 1 -UV irradiation direction: 0 to 70 ° (for example, 40 °) from the normal direction of the substrate surface
  • the exposure process is performed so that the total irradiation amount of the exposure joint portion is smaller than the irradiation amount E0 of the normal exposure portion.
  • the inventors made a prototype of the following panel.
  • the total irradiation amount of the exposure joint was adjusted with the color filter substrate.
  • batch exposure was performed without performing splice exposure on the array substrate. That is, the entire surface of the array substrate was exposed at once.
  • the orientation of the first exposure and the second exposure on the array substrate was the left-right direction.
  • each photomask 70 is provided with a central region 73 and an overlap region 74, and a translucent part 75 having the same length in the central region 73 (in the first translucent part).
  • a translucent portion 76 (corresponding to the second translucent portion) is provided in the overlap region 74 so that the length of the translucent portion 76 gradually decreases as the distance from the central region 73 increases.
  • the first exposure (1) and the first exposure (2), the second exposure (1) and the second exposure (2) are the same part (for example, the same half on the same side of the picture element).
  • the mask 70 was designed to be exposed.
  • the following three types of masks were used as the mask 70 to produce panels 1 to 3.
  • the first mask was designed so that the total irradiation amount of the exposure joints was constant and 100%.
  • the second and third masks are designed so that the total irradiation amount of the exposure joint portion is higher than 100%, and the second mask is such that the maximum irradiation amount E max of the exposure joint portion is 125%.
  • the third mask was designed so that the E max of the exposed joint was 150%.
  • the exposed joint 25 When viewed from the front direction, the exposed joint 25 was not visible over all gradations. (2) When viewed obliquely in the left-right direction (0 ° or 180 ° azimuth), the exposure joint portion 25 appeared brighter than the normal exposure portion 24 in a strip shape with a gray gradation (low gradation). (3) When viewed obliquely in the up-down direction (90 ° or 270 ° azimuth), the exposure joint portion 25 looks darker than the normal exposure portion 24 in a strip shape with a low gradation. (4) Although the degree of the above-mentioned appearance becomes lighter in the order of 150%, 125%, and 100%, the exposure joint portion 25 was visually recognized even in the case of 100%.
  • FIG. 25 shows the result of measuring the luminance unevenness from the oblique 60 ° direction in the left-right direction (0 ° or 180 ° azimuth). This was measured while scanning the luminance meter in the horizontal direction. As shown in FIG. 25, the tendency of the above visual result (4) was also reproduced by the measurement of the luminance meter. That is, at 100%, it can be said that the exposure to the joint portion is still excessive.
  • FIG. 26 is a diagram schematically showing the alignment direction of the liquid crystal molecules in each pixel in the normal exposure portion for the prototype panels 1 to 3.
  • FIG. 27 is a diagram schematically showing the orientation direction of the liquid crystal molecules in each picture element in the joint portion of the prototype panels 1 to 3. 26 and 27, the solid line arrow indicates the tilt direction on the color filter substrate, and the dotted line arrow indicates the tilt direction on the array substrate. In the normal exposure portion, the tilt angle on the array substrate and the tilt angle on the color filter substrate are substantially equal, and as shown in FIG. 26, the liquid crystal molecules are tilted in an orientation that bisects the tilt direction of both substrates.
  • the liquid crystal molecules are pulled down in the tilt direction on the color filter substrate when the voltage is applied at the exposure joint portion. That is, it is considered that the tilt angle is lower at the exposure joint portion than at the normal exposure portion even when the total irradiation amount is 100%.
  • the antinode portion of the liquid crystal molecules (the portion having a large phase difference) is seen from the left and right directions, looks brighter than the normal exposure portion, and the head of the liquid crystal molecules from the up and down directions. This portion (the portion with a small phase difference) is seen more, and it is considered that the portion looks darker than the normal exposure portion.
  • the ratio (percentage) of the total irradiation amount of the exposure joint portion to the irradiation amount of the normal exposure portion needs to be less than 100% particularly in the scanning exposure method.
  • joint exposure was performed on the array substrate side.
  • the array substrate was divided into six regions and subjected to scanning exposure in the vertical direction. That is, in this prototype, there are five exposure joints 25 as shown in FIG. The width of the exposure joint portion 25 was set to 45 mm.
  • the exposure joint portion 25 was visually observed from the oblique direction in the left-right direction without passing through the ND filter or through the ND filter.
  • the results are shown in Table 1 below.
  • the observation was performed at 32 gradations, which is the gradation at which the exposed joint portion is most easily visible.
  • OK the gradation at which the exposed joint portion is most easily visible.
  • NG the gradation at which the exposed joint portion is most easily visible.
  • ND 1% OK means that the exposed joint is not visible through the 1% ND filter
  • ND 3% NG means that the exposed joint is visible through the 3% ND filter. Note that the amount of light transmitted from the filter decreases as the ND value decreases.
  • FIG. 30 is a diagram schematically showing the alignment direction of the liquid crystal molecules in each pixel in the normal exposure portion for the prototype panels 4 to 13.
  • FIG. 31 is a diagram schematically showing the orientation direction of the liquid crystal molecules in each picture element in the exposure joint for the prototype panels 4 to 13.
  • a solid arrow indicates a tilt direction on the color filter substrate
  • a dotted arrow indicates a tilt direction on the array substrate.
  • the tilt angle on the array substrate and the tilt angle on the color filter substrate are substantially equal.
  • FIG. It falls to the direction to divide. For example, when the minimum irradiation amount of the exposure joint portion is 74.8%, the exposure joint portion appears dark from an oblique direction in the left-right direction.
  • the exposure dose at the exposure joint is insufficient at 74.8%, and the tilt angle of the exposure joint is higher than the tilt angle of the normal exposure on the array substrate. This is considered to be caused by being pulled in the tilt direction on the color filter substrate side and falling down.
  • the head portion of liquid crystal molecules when viewed obliquely in the left-right direction, the head portion of liquid crystal molecules (the portion having a smaller phase difference) is seen more, and it is considered darker than the portions other than the exposure joint portion. It is done.
  • the exposed joint portion looks a little dark, but it is at the ND3% OK level, which is acceptable in practical use. Further, if the range of 91.5 ⁇ E min ⁇ 95.8, a ND10% OK level, said to be non-defective panels no problem. From this result, in the present embodiment, it can be said that the range of the total irradiation amount of the exposure joint portion is preferably 85 ⁇ E min ⁇ 100, and more preferably 91 ⁇ E min ⁇ 96.
  • the exposure apparatus 30 having one stage 32 has been described.
  • the exposure apparatus 30 may have a plurality of stages.
  • a stage may be provided for each of the first exposure (1), the first exposure (2), the second exposure (1), and the second exposure (2).
  • Emodiment 2 The present embodiment is almost the same as the first embodiment except that the exposure apparatus to be used is different and the aspect of the exposure process is different.
  • the exposure apparatus includes an exposure stage 232 including a plurality of exposure heads 231 as shown in FIG.
  • Each exposure head 231 includes a light source and optical member for first exposure (1) and (2), a light source and optical member for second exposure (1) and (2), and a photomask 250.
  • Each photomask 250 is formed with a light-transmitting portion pattern 251a for the first exposure (1) and (2) and a light-transmitting portion pattern 251b for the second exposure (1) and (2).
  • the light-transmitting portion patterns 251a and 251b are arranged so as to be shifted from each other by half the pixel pitch, for example.
  • the mask 250 has a central region 253 and an overlap region 254. The length of the translucent part provided in the overlap region 254 gradually decreases as the distance from the central region 253 increases.
  • the polarized ultraviolet rays generated from the light sources for the first exposure (1) and (2) are irradiated to the light transmitting portion pattern 251a, and the second exposure (1) and (2).
  • the substrate 10 is allowed to pass under the mask 250 in a state where the polarized ultraviolet rays generated from the light source for use are irradiated onto the light transmitting portion pattern 251b.
  • These polarized ultraviolet rays are irradiated from opposite directions.
  • the first exposure (1) and the second exposure (1) can be performed simultaneously, and the first exposure (2) and the second exposure (2) can be performed simultaneously. That is, the alignment process of the substrate 10 is completed only by performing scanning exposure twice in total.
  • the tilt direction C of the liquid crystal molecules in the vicinity of the photo-alignment film is the same as in the first embodiment.
  • the exposure apparatus may have a plurality of stages. For example, a stage for the first exposure (1) and the second exposure (1) and a stage for the first exposure (2) and the second exposure (2) may be provided.
  • Embodiment 3 This embodiment is almost the same as Embodiments 1 and 2 except that the exposure apparatus used is different and the aspect of the exposure process is different.
  • each exposure head includes a photomask 350 and a light shielding member 356, as shown in FIG.
  • a plurality of light-transmitting portions 351 having the same length are formed on the photomask 350, but a part of the light-transmitting portion 351 on the end side is a light-shielding member so that the aperture ratio of the light-transmitting portion 351 gradually decreases. 356 is shielded from light.
  • the total irradiation amount of the exposure joint portion can be made smaller than the irradiation amount of the normal exposure portion.
  • the light shielding member 356 may be any member that partially blocks light from the light source, and for example, an optical shutter, an optical blind, or the like can be selected as appropriate.
  • a mechanism for changing the arrangement position of the light shielding member 356 mechanically may be provided in the member 356. In this case, there is an advantage that the irradiation amount of the exposure joint portion can be easily adjusted.
  • Array substrate 2 Color filter substrate 3: Liquid crystal layers 4, 4a, 4b: Liquid crystal molecules 6a, 6b: Polarizing plates 7a, 7b: Phase difference plate 10: Mother glass substrate 10a: Mother glass substrate 10b for array substrate: Mother glass substrate 11 for color filter substrate: panel region 12: source bus line 13: gate bus line 14: thin film transistor 15: picture element electrode 16: black matrix 17: color filter 19: photo-alignment films 18, 21, 22, 23 A1, A2, B1, B2: Area 24: Normal exposure section 25: Exposure joint section 30: Exposure apparatus 31, 231: Exposure head 32, 232: Exposure stage 33: Table 34: Ultraviolet light source 35: Imaging means 41: Proxy Mitty gap 50, 250, 350: Photomask 52: Light shielding parts 51, 55, 56, 61, 65, 6, 71, 75, 76, 351: Translucent portions 53, 63, 73, 253: Central regions 54, 64, 74, 254: Overlap region 60: Photomask for array substrate 70

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  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Liquid Crystal (AREA)

Abstract

L'invention concerne un dispositif d'exposition, lequel permet de supprimer l'apparition de coupures sur un écran d'affichage, même lorsque le processus d'orientation est effectué au moyen d'une exposition par balayage. L'invention concerne également un dispositif d'affichage à cristaux liquides associé, ainsi que le procédé de fabrication de ce dispositif d'exposition et de ce dispositif d'affichage. Plus spécifiquement, l'invention concerne un dispositif d'exposition qui permet d'exposer un film d'orientation optique en déplaçant, relativement à une lumière d'exposition, un substrat sur la surface duquel a été placé un film d'orientation. Ce dispositif d'exposition effectue une première exposition consistant à exposer une première partie et une deuxième partie du film d'orientation, ainsi qu'une seconde exposition consistant à exposer une troisième partie du film d'orientation et à ré-exposer la deuxième partie du film d'orientation. La deuxième partie du film d'orientation se situe entre la première partie et la troisième partie. La première exposition est effectuée de façon à ce que la quantité de rayonnement sur la deuxième partie soit inférieure à la quantité de rayonnement sur la première partie. De même, la seconde exposition est effectuée de façon à ce que la quantité de rayonnement sur la deuxième partie soit inférieure à la quantité de rayonnement sur la troisième partie. En outre, ce dispositif d'exposition est réglé de façon que le total de la quantité de rayonnement sur la deuxième partie lors de la première exposition et lors de la deuxième exposition soit inférieur à la fois à la quantité de rayonnement sur la première partie et à la quantité de rayonnement sur la troisième partie.
PCT/JP2012/050662 2011-01-24 2012-01-16 Dispositif d'exposition, dispositif d'affichage à cristaux liquides ainsi que leur procédé de fabrication WO2012102104A1 (fr)

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WO2014034471A1 (fr) * 2012-08-27 2014-03-06 シャープ株式会社 Dispositif d'affichage à cristaux liquides
JP2016529489A (ja) * 2013-07-12 2016-09-23 ジェネンテック， インコーポレイテッド イオン交換クロマトグラフィーのインプットの最適化の解明
CN111290175A (zh) * 2020-02-16 2020-06-16 南京中电熊猫液晶显示科技有限公司 一种掩膜版
CN111566549A (zh) * 2018-01-19 2020-08-21 堺显示器制品株式会社 液晶显示装置的制造方法及光掩模
CN111856822A (zh) * 2020-06-29 2020-10-30 南京中电熊猫平板显示科技有限公司 双层掩膜版及其使用方法、改善双层掩膜版的漏光方法
CN112068396A (zh) * 2020-09-25 2020-12-11 南京中电熊猫液晶显示科技有限公司 一种掩膜版

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WO2007086474A1 (fr) * 2006-01-26 2007-08-02 Sharp Kabushiki Kaisha Procédé de fabrication d’un dispositif d’affichage à cristaux liquides, et dispositif d’affichage à cristaux liquides
WO2008069181A1 (fr) * 2006-12-05 2008-06-12 Sharp Kabushiki Kaisha Dispositif d'affichage à cristaux liquides

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WO2007086474A1 (fr) * 2006-01-26 2007-08-02 Sharp Kabushiki Kaisha Procédé de fabrication d’un dispositif d’affichage à cristaux liquides, et dispositif d’affichage à cristaux liquides
WO2008069181A1 (fr) * 2006-12-05 2008-06-12 Sharp Kabushiki Kaisha Dispositif d'affichage à cristaux liquides

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014034471A1 (fr) * 2012-08-27 2014-03-06 シャープ株式会社 Dispositif d'affichage à cristaux liquides
JP2016529489A (ja) * 2013-07-12 2016-09-23 ジェネンテック， インコーポレイテッド イオン交換クロマトグラフィーのインプットの最適化の解明
US10274466B2 (en) 2013-07-12 2019-04-30 Genentech, Inc. Elucidation of ion exchange chromatography input optimization
US10921297B2 (en) 2013-07-12 2021-02-16 Genentech, Inc. Elucidation of ion exchange chromatography input optimization
CN111566549A (zh) * 2018-01-19 2020-08-21 堺显示器制品株式会社 液晶显示装置的制造方法及光掩模
CN111566549B (zh) * 2018-01-19 2023-03-24 堺显示器制品株式会社 液晶显示装置的制造方法及光掩模
CN111290175A (zh) * 2020-02-16 2020-06-16 南京中电熊猫液晶显示科技有限公司 一种掩膜版
CN111856822A (zh) * 2020-06-29 2020-10-30 南京中电熊猫平板显示科技有限公司 双层掩膜版及其使用方法、改善双层掩膜版的漏光方法
CN112068396A (zh) * 2020-09-25 2020-12-11 南京中电熊猫液晶显示科技有限公司 一种掩膜版

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