WO2009154105A1 - Method for evaluating luminance nonuniformity of display glass substrate, method for manufacturing display glass substrate, and display glass substrate wherein luminance nonuniformity is not easily generated - Google Patents

Method for evaluating luminance nonuniformity of display glass substrate, method for manufacturing display glass substrate, and display glass substrate wherein luminance nonuniformity is not easily generated Download PDF

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Publication number
WO2009154105A1
WO2009154105A1 PCT/JP2009/060529 JP2009060529W WO2009154105A1 WO 2009154105 A1 WO2009154105 A1 WO 2009154105A1 JP 2009060529 W JP2009060529 W JP 2009060529W WO 2009154105 A1 WO2009154105 A1 WO 2009154105A1
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Prior art keywords
glass substrate
display
polarizing plate
luminance unevenness
evaluating
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PCT/JP2009/060529
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French (fr)
Japanese (ja)
Inventor
嘉成 加藤
大和 岡本
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日本電気硝子株式会社
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Publication of WO2009154105A1 publication Critical patent/WO2009154105A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/8803—Visual inspection
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N21/958—Inspecting transparent materials or objects, e.g. windscreens
    • 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
    • G02F1/1306—Details
    • G02F1/1309—Repairing; Testing
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N2021/9513—Liquid crystal panels
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/21—Polarisation-affecting properties
    • G01N21/23—Bi-refringence

Definitions

  • the present invention relates to a glass substrate for display which prevents luminance unevenness generated in a display panel.
  • a flat panel display has become popular in recent years.
  • a liquid crystal display is relatively power-saving, it is used in various display devices such as a television, a mobile phone, a portable game machine, and a car navigation system.
  • a liquid crystal sandwiched between glass substrates for a liquid crystal display in which a transparent electrode is arranged between a pair of orthogonal polarizing plates, is arranged, and the orientation of the liquid crystal molecules is changed by applying a voltage between the transparent electrodes.
  • An image or the like is displayed by changing the polarization state of the light emitted from the light.
  • the luminance unevenness generated in the liquid crystal display is a big problem. However, it takes time and money to evaluate the luminance unevenness after assembling the liquid crystal panel. An evaluation is necessary.
  • Patent Document 1 proposes a photoelastic device comprising two orthogonal polarizing plate (polarizer and analyzer) sample stands.
  • polarizer and analyzer polarizer and analyzer
  • an image of the strain is observed when the glass plate has a strain.
  • the darkly observed part corresponds to the part where the principal stress of the glass plate coincides with the direction of the main axis of the polarizing plate, and the glass plate on the sample table is rotated with respect to the polarizing plate, or The main stress line of the glass plate can be obtained by rotating and observing the plate with respect to the glass plate on the sample stage.
  • Patent Document 2 in order to provide a glass substrate for display that suppresses deflection during conveyance and thermal warp due to heat treatment, a single glass substrate is subjected to deviation stress at a plurality of points at a predetermined interval, and the optical path difference of birefringence. It is described that the distortion is measured by calculating from the above.
  • the present invention has been made to solve the above-mentioned problems of the prior art, and before assembling as a display panel, brightness unevenness generated in the glass substrate can be quickly and inexpensively assembled in the state of the glass substrate. It is another object of the present invention to provide a method that can be accurately evaluated, a method for manufacturing a glass substrate for display, and a glass substrate for display that can prevent occurrence of luminance unevenness.
  • the invention according to claim 1 includes a first polarizing plate disposed in a direction in which light is emitted from a light source, and a second polarizing plate disposed so as to be orthogonal to the polarization axis of the first polarizing plate.
  • a display glass substrate is inserted between them, and the light transmitted from the light source through the first polarizing plate, the display glass substrate, and the second polarizing plate is detected, and luminance unevenness is evaluated.
  • the present invention relates to a method for evaluating luminance unevenness of a substrate, wherein the display glass substrate is brought into surface contact with the first polarizing plate and the second polarizing plate.
  • the glass substrate, the first polarizing plate, and the second polarizing plate are in surface contact within a range equal to or greater than the region of the display glass substrate (luminance unevenness evaluation range) where luminance unevenness is to be evaluated. .
  • the invention according to claim 2 relates to the method for evaluating luminance unevenness of a glass substrate for display according to claim 1, wherein the light source and the first polarizing plate are in contact with each other.
  • the invention according to claim 3 relates to a method for evaluating luminance unevenness of a glass substrate for display according to claim 1 or 2, wherein the light source has a luminance of 8000 cd / m 2 or more.
  • the invention according to claim 4 is characterized in that the thickness of the glass substrate for display is 0.01 mm to 1.1 mm, and the luminance unevenness evaluation of the glass substrate for display according to any one of claims 1 to 3 Regarding the method.
  • the invention according to claim 5 relates to the method for evaluating luminance unevenness of a glass substrate for display according to any one of claims 1 to 4, wherein the length of one side of the glass substrate for display is 900 mm or more. .
  • the invention according to claim 6 is evaluated from a position having a viewing angle of 10 ° to 80 ° from the second polarizing plate, and the luminance unevenness of the glass substrate for display according to any one of claims 1 to 5 It relates to the evaluation method.
  • the present invention relates to a method for evaluating luminance unevenness of a glass substrate.
  • the invention according to claim 8 relates to the luminance unevenness evaluation method for a glass substrate for display according to any one of claims 1 to 7, wherein the evaluation is performed from a position 2 to 6 m away from the second polarizing plate.
  • the invention according to claim 9 relates to a method for evaluating luminance unevenness of a glass substrate for display according to any one of claims 1 to 8, wherein the glass substrate for display is a glass substrate for liquid crystal display.
  • the invention according to claim 10 relates to the luminance unevenness evaluation method for a glass substrate for display according to claim 9, wherein the light source is a backlight unit for liquid crystal display.
  • a first step of producing a glass substrate for display by cutting an edge portion after cutting into a predetermined length while conveying a glass ribbon after molding, and light from a light source Produced in the first step between the first polarizing plate arranged in the direction of irradiation of the first polarizing plate and the second polarizing plate arranged to be orthogonal to the polarization axis of the first polarizing plate. And a second step of bringing the display glass substrate into contact with each other after the insertion, and detecting light transmitted from the light source through the first polarizing plate, the display glass substrate, and the second polarizing plate. And a third step of evaluating luminance unevenness, and a fourth step of selecting the evaluated glass substrate for display into a non-defective product and a defective product. .
  • the invention according to claim 12 relates to a glass substrate for display manufactured by the manufacturing method according to claim 11.
  • the display glass substrate is brought into surface contact with the first polarizing plate and the second polarizing plate, it is hardly affected by the scattered light on the surface of these members, and the contrast is reduced. A good image can be obtained. Therefore, before assembling as a display panel, the luminance unevenness generated in the glass substrate can be evaluated quickly and accurately at a low cost in the state of the glass substrate.
  • the glass substrate, the first polarizing plate, and the second polarizing plate are configured to be in surface contact within a range equal to or greater than the area of the display glass substrate (luminance unevenness evaluation range) where luminance unevenness is to be evaluated.
  • the luminance unevenness evaluation range of the glass substrate can be inspected at a time, and the time required for the inspection is shortened.
  • the luminance unevenness may be caused by a member other than the display glass substrate (for example, a backlight unit or a deflecting plate), but the display panel is actually assembled by using the method of the present invention. Therefore, it is possible to evaluate the luminance unevenness caused by the glass substrate more accurately than in the case of the above.
  • the positions of the light source and the first polarizing plate are the same as when the display panel is assembled.
  • the brightness unevenness of the display glass substrate can be evaluated in a state closer to the state in which the panel is created, and the brightness unevenness of the display glass substrate can be more accurately evaluated.
  • the luminance of the light source is 8000 cd / m 2 or more, the portion where light is transmitted from the orthogonal polarizing plate is emphasized more brightly. Evaluation of luminance unevenness of the glass substrate can be performed.
  • the plate thickness of the glass substrate for display is 0.01 mm to 1.1 mm
  • the conditions are the same as the thickness of the glass substrate actually used for the display. Therefore, the luminance unevenness of the display glass substrate can be evaluated in a state closer to the state in which the display panel is created, and the luminance unevenness of the display glass substrate can be more accurately evaluated.
  • the length of one side of the glass substrate for a display is 900 mm or more, the brightness nonuniformity of the glass substrate for a display used for the large sized display in which a luminance nonuniformity is easy to generate
  • produce is more. It can be evaluated quickly and accurately.
  • the contrast of the evaluation surface does not change and the average luminance is improved. Therefore, it is possible to easily evaluate luminance unevenness.
  • the 1st polarizing plate, the 2nd polarizing plate, and the glass substrate for a display are standingly arranged, the brightness nonuniformity evaluation of the glass substrate for a display is performed more correctly. be able to.
  • the evaluation is performed from a position 2 to 6 m away from the second polarizing plate, it is easy to check the luminance unevenness of the glass substrate for display, and the user can actually use the thin TV.
  • the luminance unevenness of the display glass substrate can be more accurately evaluated from the viewing distance.
  • the glass substrate for a display is a glass substrate for a liquid crystal display
  • the luminance unevenness of the glass substrate for a liquid crystal display used for a liquid crystal display that is more likely to generate luminance unevenness is evaluated. Can do.
  • the light source is a backlight unit for a liquid crystal display
  • the same light source as the light source used for the liquid crystal display is used, so the state is closer to the state in which the liquid crystal display panel is created.
  • the luminance unevenness of the glass substrate for liquid crystal displays can be evaluated, and the luminance unevenness of the glass substrate for display can be more accurately evaluated.
  • Second step of bringing the display glass substrate into contact with each other and inserting light from the light source through the first polarizing plate, the display glass substrate, and the second polarizing plate to detect luminance unevenness The third step of evaluating the display and the fourth step of selecting the evaluated display glass substrate into a non-defective product and a defective product, thereby preventing occurrence of uneven brightness when incorporated in a display panel Enable It is possible to manufacture a glass substrate for display.
  • the twelfth aspect of the invention since it is a glass substrate for display manufactured by the manufacturing method according to the eleventh aspect, it is possible to prevent occurrence of uneven brightness when incorporated in a display panel. It can be set as the glass substrate for a display.
  • the method for evaluating luminance unevenness of a glass substrate for display according to the present invention includes a first polarizing plate (2) disposed in a direction in which light is irradiated from a light source (1), and polarization of the first polarizing plate (2).
  • a glass substrate for display (4) is inserted between the second polarizing plate (3) arranged to be orthogonal to the axis, the first polarizing plate (2), the glass substrate for display (4), and The second polarizing plate (3) and the glass substrate for display (4) are brought into surface contact.
  • surface contact means not only when the glass substrate for display, the first polarizing plate, and the second polarizing plate are uniformly in contact with each other, but with a slight partial The case where they are separated, that is, the case where the surfaces substantially contact each other is also included.
  • the type of the light source (1) is not particularly limited, and a fluorescent lamp, an incandescent lamp, a light emitting diode, or the like can be used.
  • the number of the light sources (1) to be arranged is appropriately selected depending on the type of the light source (1), but at least the number capable of uniformly irradiating the entire surface of the first polarizing plate is required.
  • the light color is not particularly limited, but it is preferable to use a light color. This is because the first polarizing plate (2) and the second polarizing plate (3) are orthogonal to each other, so that when dark colors are used, light may be hardly detected with the naked eye. Usually white light is used.
  • Brightness of the light source (1) is preferably 8000 cd / m 2 or more, more preferably 10000 cd / m 2 or more. This is because the portion where light is transmitted from the orthogonal polarizing plate is emphasized more brightly, so that the luminance unevenness of the glass substrate for display can be evaluated more quickly and accurately.
  • the light source (1) is preferably arranged so as to be in contact with the first polarizing plate (2) as shown in FIG. This is because the luminance unevenness of the display glass substrate can be evaluated in a state closer to the state in which the display panel is created, and the luminance unevenness of the display glass substrate can be more accurately evaluated.
  • the first polarizing plate (2) is a plate-like body having a substantially rectangular shape in plan view, and is composed of a polarizing film (21) and a plate-like transparent body (22) as shown in FIG. It is comprised by sticking a polarizing film (21) to 22).
  • the size of the first polarizing plate (2) is preferably equal to or larger than the size of the glass substrate for display (4) for evaluating the luminance unevenness, and at least the polarizing film (21) is the glass substrate for display (4). It is necessary to be within the luminance unevenness evaluation range of
  • the first polarizing plate (2) is disposed such that the plate-like transparent body (22) is on the light source (1) side and the polarizing film (21) is on the display glass substrate (4) side. This is because only the luminance unevenness due to the glass substrate for display (4) is evaluated without being affected by the distortion of the plate-like transparent body (22).
  • the plate-like transparent body (22) needs to be a material having high rigidity and is difficult to be deformed, and plate glass, hard plastic, or the like can be used.
  • the plate thickness of the plate-like transparent body (22) is appropriately selected depending on the rigidity of the selected material, but it is preferable that the plate-like transparent body (22) has a plate thickness that does not deform at least when the evaluation method according to the present invention is used.
  • the plate thickness is preferably 0.5 mm or more.
  • the plate-like transparent body (22) needs to be at least as large as the polarizing film (21).
  • the second polarizing plate (3) is a plate-like body having a substantially rectangular shape in plan view. As shown in FIG. 2, the polarizing plate (31) and the plate-like transparent body ( 32), and is configured by sticking a polarizing film (31) to a plate-like transparent body (32).
  • the size of the second polarizing plate (3) is the same as that of the first polarizing plate (2), and is usually the same as that of the first polarizing plate (2).
  • the second polarizing plate (3) is arranged so that the polarizing film (31) is on the display glass substrate (4) side.
  • the glass substrate for display (4) is made of silicate glass, preferably silica glass or borosilicate glass, most preferably non-alkali borosilicate glass.
  • the alkali-free borosilicate glass is a glass that does not substantially contain an alkali component, and specifically, a glass having an alkali component of 1000 ppm or less.
  • the content of the alkali component in the present invention is preferably 500 ppm or less, more preferably 300 ppm or less of the alkali component.
  • the glass substrate for display (4) is a plate-like body having a substantially rectangular shape in plan view, and preferably has a plate thickness of 0.01 mm to 1.1 mm. This is because if the thickness is less than 0.01 mm, it is easily affected by light interference or internal distortion due to deformation of the glass substrate for display to be evaluated, and if it is too thick, the luminance at the time of evaluation decreases.
  • a more preferable plate thickness is 0.1 mm to 0.7 mm, and a further preferable plate thickness is 0.1 mm to 0.5 mm.
  • the length of one side of the glass substrate for display (4) is preferably 900 mm or more. This is because it is possible to evaluate the luminance unevenness of the glass substrate used in a large display in which luminance unevenness is likely to occur.
  • the glass substrate for display (4) used in the present invention can be formed by a known method such as a roll-out method, a float method, a slit down method, an overflow down draw method or the like. Especially, it is preferable to shape
  • the overflow down draw method is a molding method in which both sides of the glass plate do not come into contact with the molding member during molding, and both surfaces (translucent surface) of the obtained glass film are hardly damaged and have a high surface without being polished. This is because quality can be obtained.
  • the first polarizing plate (2) and the glass substrate for display (4), and the second polarizing plate (3) and the glass substrate for display (4) are used. Make surface contact. If these are separated, the scattered light on the surfaces of the first polarizing plate (2), the glass substrate for display (4), and the second polarizing plate (3) is transmitted through the second polarizing plate (3). As a result, the contrast of the evaluation surface is lowered, so that the luminance unevenness evaluation of the glass substrate for display cannot be performed quickly and accurately. In the present invention, since such scattered light can be removed by surface contact, the luminance unevenness evaluation of the glass substrate for display can be performed quickly and accurately.
  • the evaluation position is not directly in front of the second polarizing plate (3), but has a certain viewing angle in the vertical and horizontal directions. It is preferable to evaluate the luminance unevenness of the glass substrate for display (4) from the direction in which it is present. It is difficult to evaluate luminance unevenness from the front of the second polarizing plate (3), and the contrast of the evaluation surface changes when the viewing angle is relative to the light source (1) (when the evaluation is performed obliquely). This is because the average luminance is improved, and it becomes easy to evaluate luminance unevenness with the naked eye. Evaluation is preferably performed from a direction having a viewing angle of 10 ° to 80 ° in the vertical direction and the horizontal direction, and more preferably evaluated from a direction having a viewing angle of 30 ° to 60 °.
  • the evaluation method for a glass substrate for a display according to the present invention makes it difficult to evaluate an appropriate luminance unevenness when there is reflected light from the surroundings. Therefore, the evaluation environment is preferably a dark place and is a dark room. More preferred.
  • the first polarizing plate (2), the second polarizing plate (3), and the glass substrate for display (4) are erected.
  • the evaluation of the luminance unevenness of the glass substrate for display (4) is difficult to determine from a nearby position, and can be performed more accurately from a distant position. Therefore, the first polarizing plate (2) and the second polarizing plate
  • the evaluation method of the glass substrate for a display which concerns on this invention is a light source (1), a 1st polarizing plate (2), a glass substrate for a display (4), a 2nd polarizing plate (3 )
  • the brightness unevenness can be evaluated from above at a distance from the second polarizing plate (3).
  • the method for evaluating a glass substrate for display it is preferable to evaluate from a position 2 to 6 m away from the second polarizing plate (3). It is easy to confirm the luminance unevenness of the glass substrate for display (4), and the luminance unevenness of the glass substrate for display (4) can be more accurately evaluated from the distance that the user actually views the thin TV. It is. When the distance is closer than 2 m, light leakage due to the viewing angle increases, and when the distance is longer than 6 m, it is difficult to evaluate with the naked eye depending on the visual acuity of the evaluator (5). ) Is not preferable because it is difficult to see the luminance unevenness.
  • the glass substrate for display (4) is preferably a glass substrate for liquid crystal display. This is because it is possible to evaluate the luminance unevenness of the glass substrate used in the liquid crystal display in which the luminance unevenness is more likely to occur.
  • the light source (1) preferably uses a liquid crystal backlight unit.
  • a liquid crystal backlight unit By using the same light source and the same glass substrate as those used for the liquid crystal display, it is possible to evaluate the luminance unevenness of the glass substrate for display in a state closer to the state in which the liquid crystal panel is created, and to display the display more accurately. This is because the luminance unevenness of the glass substrate can be evaluated.
  • a fluorescent lamp of a cold cathode ray tube or a liquid crystal backlight unit provided with a plurality of white diodes is preferably used.
  • the method for evaluating a glass substrate for a display according to the present invention has been described with respect to an embodiment in which an evaluator performs visual determination with the naked eye.
  • a known image processing apparatus such as a CCD camera
  • luminance is measured and analyzed.
  • the evaluation method of the glass substrate for display (4) according to the present invention can be performed in any form of total number survey and sampling survey.
  • the display glass substrate (4) which has been determined to be non-defective after the evaluation, is cleaned, dried, and packed after both surfaces of the substrate are polished.
  • the glass substrate for display (4) formed by the float process since a polishing process is required, it is preferable to conduct a complete survey.
  • it is preferable to conduct a sampling survey because a polishing step is not required.
  • a predetermined number of display glass substrates (4) are extracted from the production line every predetermined period, and a non-defective product is determined by using the display glass substrate (4) evaluation method according to the present invention.
  • the brightness unevenness of each lot is judged by sampling and the glass substrate for display (4) used directly for evaluation is not used as a product regardless of whether it is good or defective, but is remelted and remolded.
  • FIG. 5 is a diagram showing an example of a forming method used for the glass substrate for display according to the present invention.
  • the glass substrate for display according to the present invention can be produced by the following production method.
  • the glass ribbon (G) immediately after flowing down from the lower end portion (61) of the wedge-shaped molded body (6) is stretched downward while the shrinkage in the width direction is restricted by the cooling roller (7) to have a predetermined thickness. Until it gets thinner.
  • the glass ribbon (G) having reached the predetermined thickness is gradually cooled in a slow cooling furnace (annealer), the thermal distortion of the glass ribbon (G) is removed, the glass ribbon (G) is cut into a predetermined dimension, An edge part is cut
  • the edge portion may be cut first, and then cut to a predetermined dimension.
  • a light source such as a fluorescent lamp
  • the first polarizing plate (2), the glass substrate for display (4), and the second polarizing plate (3 ) Is observed from the second polarizing plate (4) side to evaluate the luminance unevenness of the glass substrate for display (4).
  • the brightness unevenness can be confirmed in a relatively narrow area, such as unevenness with directionality such as vertical and horizontal oblique directions, or unevenness recognized as an irregular area with different brightness from the surroundings, it is determined as defective.
  • the glass substrate for display (4) that has been determined to be non-defective is shipped after undergoing processes such as processing, polishing, washing, and packaging.
  • the glass substrate for display (4) determined to be defective is remelted, and luminance unevenness is evaluated again after re-molding.
  • a shipping operation is performed on the other display glass substrate (4) in the corresponding lot.
  • the display glass substrate (4) used for the determination is remelted without shipping.
  • all the display glass substrates (4) in the corresponding lot are remelted without being shipped.
  • the operating conditions such as the melting conditions and the molding conditions are reviewed, the luminance unevenness is evaluated for each predetermined lot, and the conditions are continuously reviewed until the display glass substrate (4) is determined to be non-defective.
  • the glass substrate for display (2) that can prevent the occurrence of uneven brightness when incorporated in a display panel can be obtained by the above-described manufacturing method.
  • the present invention can be suitably used to evaluate the presence or absence of occurrence of luminance unevenness in a display glass substrate.

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Abstract

In a method for evaluating luminance nonuniformity of a display glass substrate, a display glass substrate (4) is inserted between a first polarization plate (2) arranged in a direction where light is irradiated from a light source (1), and a second polarization plate (3) arranged to orthogonally intersect with the polarization axis of the first polarization plate (2).  Then, light transmitted through the first polarization plate (2), the display glass substrate (4), and the second polarization plate (3) from the light source (1) is detected, and luminance nonuniformity is evaluated.  The display glass substrate (4) is brought into contact with the first polarization plate (2) and the second polarization plate (3) on the surface.

Description

ディスプレイ用ガラス基板の輝度ムラ評価方法、及びディスプレイ用ガラス基板の製造方法、並びに輝度ムラが発生し難いディスプレイ用ガラス基板Method for evaluating luminance unevenness of glass substrate for display, method for producing glass substrate for display, and glass substrate for display in which luminance unevenness hardly occurs
　本発明は、ディスプレイパネルに発生する輝度ムラを防止するディスプレイ用ガラス基板に関する。 The present invention relates to a glass substrate for display which prevents luminance unevenness generated in a display panel.
　省スペース化の観点から、従来普及していたＣＲＴ型ディスプレイに替わり、近年はフラットパネルディスプレイが普及している。特に、液晶ディスプレイは比較的省電力であることから、テレビ、携帯電話、携帯ゲーム機、カーナビゲーションシステム等、様々な表示装置に使用されている。 From the viewpoint of space saving, instead of the CRT type display which has been widely used in the past, a flat panel display has become popular in recent years. In particular, since a liquid crystal display is relatively power-saving, it is used in various display devices such as a television, a mobile phone, a portable game machine, and a car navigation system.
　液晶ディスプレイは、直交する一組の偏光板の間に透明電極が配設された液晶ディスプレイ用ガラス基板に挟まれた液晶が配置され、透明電極間の電圧の印加によって液晶分子の配向を変化させ、バックライトから照射された光の偏光状態を変化させることにより、映像等を表示する。 In a liquid crystal display, a liquid crystal sandwiched between glass substrates for a liquid crystal display, in which a transparent electrode is arranged between a pair of orthogonal polarizing plates, is arranged, and the orientation of the liquid crystal molecules is changed by applying a voltage between the transparent electrodes. An image or the like is displayed by changing the polarization state of the light emitted from the light.
　一方、ガラスに歪みが存在すると、透過する光がその歪みにより複屈折を生じることが知られている。即ち液晶ディスプレイでディスプレイ用ガラス基板に歪みが存在すると、液晶の配向以外の偏光要素が加わることになり、透明電極間の電圧の印加のみでは偏光状態を制御できなくなる。その結果、液晶ディスプレイに表示ムラを生じさせ、液晶ディスプレイの品質の低下の原因となっている。また、近年の液晶ディスプレイの大画面化が輝度ムラ発生の問題を顕在化させており、特に、ディスプレイ用ガラス基板に歪みがあると、液晶ディスプレイの全面に黒色を表示した場合に偏光板から漏れてくるバックライトの光が一様で無くなるので、先記した輝度ムラが顕著に現れる。このように、液晶ディスプレイに発生する輝度ムラは大きな問題となっているが、液晶パネルを組み立てた後に輝度ムラの評価を行ったのでは時間と費用がかかるため、ガラス基板の状態で輝度ムラの評価を行う必要がある。 On the other hand, it is known that when glass has strain, transmitted light causes birefringence due to the strain. That is, if there is distortion in the glass substrate for display in a liquid crystal display, polarizing elements other than the alignment of the liquid crystal are added, and the polarization state cannot be controlled only by applying a voltage between the transparent electrodes. As a result, display unevenness occurs in the liquid crystal display, which causes a deterioration in the quality of the liquid crystal display. In addition, the recent increase in the screen size of liquid crystal displays has revealed the problem of uneven brightness. In particular, if the display glass substrate is distorted, it will leak from the polarizing plate when black is displayed on the entire surface of the liquid crystal display. Since the light coming from the backlight is not uniform, the above-described luminance unevenness appears remarkably. As described above, the luminance unevenness generated in the liquid crystal display is a big problem. However, it takes time and money to evaluate the luminance unevenness after assembling the liquid crystal panel. An evaluation is necessary.
　ガラス板の歪みを検出する装置として、下記特許文献１では、直交する二枚の偏光板（偏光子と検光子）試料台からなる光弾性装置が提案されている。二枚の偏光板の主軸を互いに直交させた状態で試料台上のガラス板を観察すると、当該ガラス板に歪が存在する場合、その歪の像が観察される。この歪像において、暗く観察される部分は、ガラス板の主応力が偏光板の主軸の方向と一致した部分に対応し、試料台上のガラス板を偏光板に対して回転させ、あるいは、偏光板を試料台上のガラス板に対して回転させて観察することにより、ガラス板の主応力線を求めることができる。 As a device for detecting the distortion of a glass plate, the following Patent Document 1 proposes a photoelastic device comprising two orthogonal polarizing plate (polarizer and analyzer) sample stands. When the glass plate on the sample stage is observed in a state where the principal axes of the two polarizing plates are orthogonal to each other, an image of the strain is observed when the glass plate has a strain. In this strain image, the darkly observed part corresponds to the part where the principal stress of the glass plate coincides with the direction of the main axis of the polarizing plate, and the glass plate on the sample table is rotated with respect to the polarizing plate, or The main stress line of the glass plate can be obtained by rotating and observing the plate with respect to the glass plate on the sample stage.
　しかしながら、下記特許文献１に記載された方法では、試料台上のガラス板と、一方の偏光板（偏光子）及び他方の偏光板（検光子）とが相互に離間した状態で配置されているため、これら部材の表面での散乱光が他方の偏光板（検光子）を通過してしまい、良好なコントラストの歪像を得ることはできない。そのため、下記特許文献１に記載された方法では、ガラス板の主応力線（主応力の方向）を求めることはできるものの、輝度ムラのように、歪の方向が一様でないことと関係し、また微小な歪の影響も受けるような繊細な品質を迅速かつ正確に評価することはできない。 However, in the method described in Patent Document 1 below, the glass plate on the sample stage, one polarizing plate (polarizer), and the other polarizing plate (analyzer) are arranged in a state of being separated from each other. Therefore, the scattered light on the surface of these members passes through the other polarizing plate (analyzer), and a distortion image with good contrast cannot be obtained. Therefore, in the method described in Patent Document 1 below, although the principal stress line (direction of principal stress) of the glass plate can be obtained, it is related to the fact that the direction of strain is not uniform, such as luminance unevenness, In addition, it is impossible to quickly and accurately evaluate delicate quality that is also affected by minute distortions.
　下記特許文献２では、搬送時のたわみや加熱処理による熱反りを抑制したディスプレイ用ガラス基板を提供するために、１枚のガラス基板を所定の間隔で複数点における偏差応力を複屈折の光路差から換算して求めることによって、歪みの測定を行う旨が記載されている。 In the following Patent Document 2, in order to provide a glass substrate for display that suppresses deflection during conveyance and thermal warp due to heat treatment, a single glass substrate is subjected to deviation stress at a plurality of points at a predetermined interval, and the optical path difference of birefringence. It is described that the distortion is measured by calculating from the above.
　しかし、この方法では１枚のガラス基板の偏差応力を複数点測定する必要があることから、１枚のガラス基板を評価する時間が多く必要となり、短時間で迅速な評価を行うことができない。また、１枚のガラス基板の区域毎に偏差応力を測定しているため、１枚のガラス基板全体の評価を一度に行うことはできない。 However, since it is necessary to measure the deviation stress of one glass substrate at a plurality of points in this method, it takes a lot of time to evaluate one glass substrate, and a quick evaluation cannot be performed in a short time. Moreover, since the deviation stress is measured for each area of one glass substrate, the evaluation of the whole glass substrate cannot be performed at once.
　上記のように、ガラス板のたわみや反りといった形状品質を評価するために、ガラス基板の歪を測定することは従来より行われていたが、ディスプレイパネルとして組み立てる前に、ガラス基板の状態で、該ガラス基板に発生する輝度ムラの程度を評価することは行われていなかった。 As described above, in order to evaluate the shape quality such as deflection and warpage of the glass plate, measuring the distortion of the glass substrate has been conventionally performed, but before assembling as a display panel, in the state of the glass substrate, Evaluation of the degree of luminance unevenness generated in the glass substrate has not been performed.
特開昭５５－５８４２８号公報JP-A-55-58428 特開２００１－１８０９５７号公報JP 2001-180957 A
　本発明は、上述したような従来技術の問題点を解決すべくなされたものであって、ディスプレイパネルとして組み立てる前に、ガラス基板の状態で、該ガラス基板に発生する輝度ムラを低コストで迅速且つ正確に評価できる方法、及びディスプレイ用ガラス基板の製造方法、並びに輝度ムラの発生を防止することを可能とするディスプレイ用ガラス基板を提供することを目的とする。 The present invention has been made to solve the above-mentioned problems of the prior art, and before assembling as a display panel, brightness unevenness generated in the glass substrate can be quickly and inexpensively assembled in the state of the glass substrate. It is another object of the present invention to provide a method that can be accurately evaluated, a method for manufacturing a glass substrate for display, and a glass substrate for display that can prevent occurrence of luminance unevenness.
　請求項１に係る発明は、光源から光が照射される方向に配置された第１の偏光板と、該第１の偏光板の偏光軸と直交するように配置された第２の偏光板との間にディスプレイ用ガラス基板を挿入し、前記光源から前記第１の偏光板、前記ディスプレイ用ガラス基板、及び前記第２の偏光板を透過する光を検知し、輝度ムラを評価するディスプレイ用ガラス基板の輝度ムラ評価方法であって、前記ディスプレイ用ガラス基板を、前記第１の偏光板及び前記第２の偏光板に面接触させることを特徴とするディスプレイ用ガラス基板の輝度ムラ評価方法に関する。好ましくは、輝度ムラを評価すべきディスプレイ用ガラス基板の領域（輝度ムラ評価範囲）以上の範囲で、該ガラス基板と第１の偏光板及び第２の偏光板とが面接触するように構成する。 The invention according to claim 1 includes a first polarizing plate disposed in a direction in which light is emitted from a light source, and a second polarizing plate disposed so as to be orthogonal to the polarization axis of the first polarizing plate. A display glass substrate is inserted between them, and the light transmitted from the light source through the first polarizing plate, the display glass substrate, and the second polarizing plate is detected, and luminance unevenness is evaluated. The present invention relates to a method for evaluating luminance unevenness of a substrate, wherein the display glass substrate is brought into surface contact with the first polarizing plate and the second polarizing plate. Preferably, the glass substrate, the first polarizing plate, and the second polarizing plate are in surface contact within a range equal to or greater than the region of the display glass substrate (luminance unevenness evaluation range) where luminance unevenness is to be evaluated. .
　請求項２に係る発明は、前記光源と前記第１の偏光板とが、接触していることを特徴とする請求項１に記載のディスプレイ用ガラス基板の輝度ムラ評価方法に関する。 The invention according to claim 2 relates to the method for evaluating luminance unevenness of a glass substrate for display according to claim 1, wherein the light source and the first polarizing plate are in contact with each other.
　請求項３に係る発明は、前記光源の輝度が、８０００ｃｄ／ｍ２以上であることを特徴とする請求項１または２に記載のディスプレイ用ガラス基板の輝度ムラ評価方法に関する。 The invention according to claim 3 relates to a method for evaluating luminance unevenness of a glass substrate for display according to claim 1 or 2, wherein the light source has a luminance of 8000 cd / m 2 or more.
　請求項４に係る発明は、前記ディスプレイ用ガラス基板の板厚が、０．０１ｍｍ～１．１ｍｍであることを特徴とする請求項１～３いずれかに記載のディスプレイ用ガラス基板の輝度ムラ評価方法に関する。 The invention according to claim 4 is characterized in that the thickness of the glass substrate for display is 0.01 mm to 1.1 mm, and the luminance unevenness evaluation of the glass substrate for display according to any one of claims 1 to 3 Regarding the method.
　請求項５に係る発明は、前記ディスプレイ用ガラス基板の１辺の長さが、９００ｍｍ以上であることを特徴とする請求項１～４いずれかに記載のディスプレイ用ガラス基板の輝度ムラ評価方法に関する。 The invention according to claim 5 relates to the method for evaluating luminance unevenness of a glass substrate for display according to any one of claims 1 to 4, wherein the length of one side of the glass substrate for display is 900 mm or more. .
　請求項６に係る発明は、前記第２の偏光板から１０°～８０°視野角を有する位置から評価することを特徴とする請求項１～５いずれかに記載のディスプレイ用ガラス基板の輝度ムラ評価方法に関する。 The invention according to claim 6 is evaluated from a position having a viewing angle of 10 ° to 80 ° from the second polarizing plate, and the luminance unevenness of the glass substrate for display according to any one of claims 1 to 5 It relates to the evaluation method.
　請求項７に係る発明は、前記第１の偏光板、前記第２の偏光板、及び前記ディスプレイ用ガラス基板が立設されていることを特徴とする請求項１～６いずれかに記載のディスプレイ用ガラス基板の輝度ムラ評価方法に関する。 The display according to any one of claims 1 to 6, wherein the first polarizing plate, the second polarizing plate, and the display glass substrate are erected. The present invention relates to a method for evaluating luminance unevenness of a glass substrate.
　請求項８に係る発明は、前記第２の偏光板から２～６ｍ離間した位置から評価することを特徴とする請求項１～７いずれかに記載のディスプレイ用ガラス基板の輝度ムラ評価方法に関する。 The invention according to claim 8 relates to the luminance unevenness evaluation method for a glass substrate for display according to any one of claims 1 to 7, wherein the evaluation is performed from a position 2 to 6 m away from the second polarizing plate.
　請求項９に係る発明は、前記ディスプレイ用ガラス基板が、液晶ディスプレイ用ガラス基板であることを特徴とする請求項１～８いずれかに記載のディスプレイ用ガラス基板の輝度ムラ評価方法に関する。 The invention according to claim 9 relates to a method for evaluating luminance unevenness of a glass substrate for display according to any one of claims 1 to 8, wherein the glass substrate for display is a glass substrate for liquid crystal display.
　請求項１０に係る発明は、前記光源は、液晶ディスプレイ用バックライトユニットであることを特徴とする請求項９に記載のディスプレイ用ガラス基板の輝度ムラ評価方法に関する。 The invention according to claim 10 relates to the luminance unevenness evaluation method for a glass substrate for display according to claim 9, wherein the light source is a backlight unit for liquid crystal display.
　請求項１１に係る発明は、成形後ガラスリボンを搬送しつつ、所定長の長さに切り出した後に端縁部を切断することによってディスプレイ用ガラス基板を作製する第１の工程と、光源から光が照射される方向に配置された第１の偏光板と、該第１の偏光板の偏光軸と直交するように配置された第２の偏光板との間に前記第１の工程で作製された前記ディスプレイ用ガラス基板を挿入した後に夫々面接触させる第２の工程と、前記光源から前記第１の偏光板、前記ディスプレイ用ガラス基板、及び前記第２の偏光板とを透過する光を検知し、輝度ムラを評価する第３の工程と、評価された前記ディスプレイ用ガラス基板を良品と不良品とに選別する第４の工程とを有することを特徴とするディスプレイ用ガラス基板の製造方法に関する。 According to an eleventh aspect of the present invention, there is provided a first step of producing a glass substrate for display by cutting an edge portion after cutting into a predetermined length while conveying a glass ribbon after molding, and light from a light source. Produced in the first step between the first polarizing plate arranged in the direction of irradiation of the first polarizing plate and the second polarizing plate arranged to be orthogonal to the polarization axis of the first polarizing plate. And a second step of bringing the display glass substrate into contact with each other after the insertion, and detecting light transmitted from the light source through the first polarizing plate, the display glass substrate, and the second polarizing plate. And a third step of evaluating luminance unevenness, and a fourth step of selecting the evaluated glass substrate for display into a non-defective product and a defective product. .
　請求項１２に係る発明は、請求項１１に記載された製造方法によって製造されたディスプレイ用ガラス基板に関する。 The invention according to claim 12 relates to a glass substrate for display manufactured by the manufacturing method according to claim 11.
　請求項１に係る発明によれば、ディスプレイ用ガラス基板を、第１の偏光板及び第２の偏光板に面接触させることから、これら部材の表面での散乱光の影響を受けにくく、コントラストの良好な画像を得ることができる。そのため、ディスプレイパネルとして組み立てる前に、ガラス基板の状態で、該ガラス基板に発生する輝度ムラを低コストで迅速且つ正確に評価することができる。特に、輝度ムラを評価すべきディスプレイ用ガラス基板の領域（輝度ムラ評価範囲）以上の範囲で、該ガラス基板と第１の偏光板及び第２の偏光板とが面接触するように構成することで、該ガラス基板の輝度ムラ評価範囲を一度に検査することができ、検査に要する時間が短縮される。また、輝度ムラは、ディスプレイ用ガラス基板以外の部材（例えばバックライトユニットや偏向板）が原因で発生する場合も考えられるが、本発明の方法を使用することにより、実際にディスプレイ用パネルを組み立てた場合よりも、より正確にガラス基板に起因する輝度ムラを評価することが可能となる。 According to the first aspect of the present invention, since the display glass substrate is brought into surface contact with the first polarizing plate and the second polarizing plate, it is hardly affected by the scattered light on the surface of these members, and the contrast is reduced. A good image can be obtained. Therefore, before assembling as a display panel, the luminance unevenness generated in the glass substrate can be evaluated quickly and accurately at a low cost in the state of the glass substrate. In particular, the glass substrate, the first polarizing plate, and the second polarizing plate are configured to be in surface contact within a range equal to or greater than the area of the display glass substrate (luminance unevenness evaluation range) where luminance unevenness is to be evaluated. Thus, the luminance unevenness evaluation range of the glass substrate can be inspected at a time, and the time required for the inspection is shortened. In addition, the luminance unevenness may be caused by a member other than the display glass substrate (for example, a backlight unit or a deflecting plate), but the display panel is actually assembled by using the method of the present invention. Therefore, it is possible to evaluate the luminance unevenness caused by the glass substrate more accurately than in the case of the above.
　請求項２に係る発明によれば、光源と第１の偏光板とが接触していることから、光源と第１の偏光板との位置がディスプレイパネルを組み立てた場合と同様となるため、ディスプレイパネルを作成した状態により近い状態でディスプレイ用ガラス基板の輝度ムラを評価することができ、より正確にディスプレイ用ガラス基板の輝度ムラの評価を行うことができる。 According to the invention of claim 2, since the light source and the first polarizing plate are in contact with each other, the positions of the light source and the first polarizing plate are the same as when the display panel is assembled. The brightness unevenness of the display glass substrate can be evaluated in a state closer to the state in which the panel is created, and the brightness unevenness of the display glass substrate can be more accurately evaluated.
　請求項３に係る発明によれば、光源の輝度が、８０００ｃｄ／ｍ２以上であることから、直交する偏光板から光が透過する箇所がより明るく強調されるため、より迅速且つ正確にディスプレイ用ガラス基板の輝度ムラの評価を行うことができる。 According to the invention of claim 3, since the luminance of the light source is 8000 cd / m 2 or more, the portion where light is transmitted from the orthogonal polarizing plate is emphasized more brightly. Evaluation of luminance unevenness of the glass substrate can be performed.
　請求項４に係る発明によれば、ディスプレイ用ガラス基板の板厚が、０．０１ｍｍ～１．１ｍｍであることから、実際にディスプレイに使用されるガラス基板の厚みと同様の厚みの条件となるため、ディスプレイパネルを作成した状態により近い状態でディスプレイ用ガラス基板の輝度ムラを評価することができ、より正確なディスプレイ用ガラス基板の輝度ムラの評価を行うことができる。 According to the invention of claim 4, since the plate thickness of the glass substrate for display is 0.01 mm to 1.1 mm, the conditions are the same as the thickness of the glass substrate actually used for the display. Therefore, the luminance unevenness of the display glass substrate can be evaluated in a state closer to the state in which the display panel is created, and the luminance unevenness of the display glass substrate can be more accurately evaluated.
　請求項５に係る発明によれば、ディスプレイ用ガラス基板の１辺の長さが、９００ｍｍ以上であることから、輝度ムラが発生し易い大型ディスプレイに用いられるディスプレイ用のガラス基板の輝度ムラをより迅速且つ正確に評価することができる。 According to the invention which concerns on Claim 5, since the length of one side of the glass substrate for a display is 900 mm or more, the brightness nonuniformity of the glass substrate for a display used for the large sized display in which a luminance nonuniformity is easy to generate | occur | produce is more. It can be evaluated quickly and accurately.
　請求項６に係る発明によれば、第２の偏光板から１０°～８０°視野角を有する位置から評価することから、評価面のコントラストは変化せず平均的な輝度が向上するため、肉眼で輝度ムラを評価し易くすることができる。 According to the invention of claim 6, since the evaluation is performed from a position having a viewing angle of 10 ° to 80 ° from the second polarizing plate, the contrast of the evaluation surface does not change and the average luminance is improved. Therefore, it is possible to easily evaluate luminance unevenness.
　請求項７に係る発明によれば、第１の偏光板、第２の偏光板、及びディスプレイ用ガラス基板が立設されていることから、ディスプレイ用ガラス基板の輝度ムラの評価をより正確に行うことができる。 According to the invention concerning Claim 7, since the 1st polarizing plate, the 2nd polarizing plate, and the glass substrate for a display are standingly arranged, the brightness nonuniformity evaluation of the glass substrate for a display is performed more correctly. be able to.
　請求項８に係る発明によれば、第２の偏光板から２～６ｍ離間した位置から評価することから、ディスプレイ用ガラス基板の輝度ムラを確認し易く、また、実際に使用者が薄型テレビを視聴する距離からより正確にディスプレイ用ガラス基板の輝度ムラの評価を行うことができる。 According to the eighth aspect of the invention, since the evaluation is performed from a position 2 to 6 m away from the second polarizing plate, it is easy to check the luminance unevenness of the glass substrate for display, and the user can actually use the thin TV. The luminance unevenness of the display glass substrate can be more accurately evaluated from the viewing distance.
　請求項９に係る発明によれば、ディスプレイ用ガラス基板が、液晶ディスプレイ用ガラス基板であることから、より輝度ムラの発生し易い液晶ディスプレイに用いられる液晶ディスプレイ用ガラス基板の輝度ムラを評価することができる。 According to the invention of claim 9, since the glass substrate for a display is a glass substrate for a liquid crystal display, the luminance unevenness of the glass substrate for a liquid crystal display used for a liquid crystal display that is more likely to generate luminance unevenness is evaluated. Can do.
　請求項１０に係る発明によれば、光源は、液晶ディスプレイ用バックライトユニットであることから、液晶ディスプレイに使用される光源と同一の光源を使用するため、液晶ディスプレイパネルを作成した状態により近い状態で液晶ディスプレイ用ガラス基板の輝度ムラを評価することができ、より正確にディスプレイ用ガラス基板の輝度ムラの評価を行うことができる。 According to the invention of claim 10, since the light source is a backlight unit for a liquid crystal display, the same light source as the light source used for the liquid crystal display is used, so the state is closer to the state in which the liquid crystal display panel is created. Thus, the luminance unevenness of the glass substrate for liquid crystal displays can be evaluated, and the luminance unevenness of the glass substrate for display can be more accurately evaluated.
　請求項１１に係る発明によれば、成形後ガラスリボンを搬送しつつ、所定長の長さに切り出した後に端縁部を切断することによってディスプレイ用ガラス基板を作製する第１の工程と、光源から光が照射される方向に配置された第１の偏光板と、第１の偏光板の偏光軸と直交するように配置された第２の偏光板との間に前記第１の工程で作製されたディスプレイ用ガラス基板を挿入した後に夫々面接触させる第２の工程と、光源から第１の偏光板、ディスプレイ用ガラス基板、及び第２の偏光板とを透過する光を検知し、輝度ムラを評価する第３の工程と、評価されたディスプレイ用ガラス基板を良品と不良品とに選別する第４の工程とを有することから、ディスプレイパネルに組み込んだ場合に輝度ムラの発生を防止することを可能とするディスプレイ用ガラス基板を製造することができる。 According to the eleventh aspect of the invention, the first step of producing the glass substrate for display by cutting the edge portion after cutting the glass ribbon into a predetermined length while conveying the glass ribbon after molding, and the light source Produced in the first step between the first polarizing plate arranged in the direction in which the light is irradiated from and the second polarizing plate arranged to be orthogonal to the polarization axis of the first polarizing plate. Second step of bringing the display glass substrate into contact with each other and inserting light from the light source through the first polarizing plate, the display glass substrate, and the second polarizing plate to detect luminance unevenness The third step of evaluating the display and the fourth step of selecting the evaluated display glass substrate into a non-defective product and a defective product, thereby preventing occurrence of uneven brightness when incorporated in a display panel Enable It is possible to manufacture a glass substrate for display.
　請求項１２に係る発明によれば、請求項１１に記載された製造方法によって製造されたディスプレイ用ガラス基板であることから、ディスプレイパネルに組み込んだ場合に輝度ムラの発生を防止することを可能とするディスプレイ用ガラス基板とすることができる。 According to the twelfth aspect of the invention, since it is a glass substrate for display manufactured by the manufacturing method according to the eleventh aspect, it is possible to prevent occurrence of uneven brightness when incorporated in a display panel. It can be set as the glass substrate for a display.
本発明に係るディスプレイ用ガラス基板の輝度ムラ評価方法の概略構成図である。It is a schematic block diagram of the brightness | luminance nonuniformity evaluation method of the glass substrate for displays which concerns on this invention. 本発明に係るディスプレイ用ガラス基板の輝度ムラ評価方法で使用される偏光板の詳細図である。It is detail drawing of the polarizing plate used with the brightness nonuniformity evaluation method of the glass substrate for displays which concerns on this invention. 本発明に係るディスプレイ用ガラス基板の輝度ムラ評価方法で輝度ムラを実際に評価している状態を示す説明図である。It is explanatory drawing which shows the state which is actually evaluating the brightness nonuniformity with the brightness nonuniformity evaluation method of the glass substrate for displays which concerns on this invention. 本発明に係るディスプレイ用ガラス基板の輝度ムラ評価方法の他の実施形態を示す説明図である。It is explanatory drawing which shows other embodiment of the brightness nonuniformity evaluation method of the glass substrate for displays which concerns on this invention. 本発明に係るディスプレイ用ガラス基板に使用される成形法の一例を示す図である。It is a figure which shows an example of the shaping | molding method used for the glass substrate for displays which concerns on this invention.
　以下、本発明に係るディスプレイ用ガラス基板の輝度ムラ評価方法の好適な実施形態について、図面を参照しつつ説明する。 Hereinafter, preferred embodiments of a method for evaluating luminance unevenness of a glass substrate for display according to the present invention will be described with reference to the drawings.
　本発明に係るディスプレイ用ガラス基板の輝度ムラ評価方法は、光源（１）から光が照射される方向に配置された第１の偏光板（２）と、第１の偏光板（２）の偏光軸と直交するように配置された第２の偏光板（３）との間にディスプレイ用ガラス基板（４）を挿入し、第１の偏光板（２）とディスプレイ用ガラス基板（４）、及び第２の偏光板（３）とディスプレイ用ガラス基板（４）とを面接触させることを特徴としている。 The method for evaluating luminance unevenness of a glass substrate for display according to the present invention includes a first polarizing plate (2) disposed in a direction in which light is irradiated from a light source (1), and polarization of the first polarizing plate (2). A glass substrate for display (4) is inserted between the second polarizing plate (3) arranged to be orthogonal to the axis, the first polarizing plate (2), the glass substrate for display (4), and The second polarizing plate (3) and the glass substrate for display (4) are brought into surface contact.
　ここでの「面接触」とは、ディスプレイ用ガラス基板、第１の偏光板、及び第２の偏光板がそれぞれ一様にすべての部分において接触している場合のみではなく、部分的に僅かに離反している場合、つまり、実質的に面同士が接触している場合も含まれる。 Here, “surface contact” means not only when the glass substrate for display, the first polarizing plate, and the second polarizing plate are uniformly in contact with each other, but with a slight partial The case where they are separated, that is, the case where the surfaces substantially contact each other is also included.
　光源（１）は、種類については特に限定されず、蛍光灯、白熱電球、発光ダイオード等を使用することができる。光源（１）の配置数は、光源（１）の種類によって適宜選択されるが、少なくとも第１の偏光板の全面を均一に照射することが可能な個数が必要とされる。光色については特に限定はされないが、明色を使用することが好ましい。第１の偏光板（２）と第２の偏光板（３）とは直交しているため、暗色を使用すると、肉眼ではほとんど光を検出することができない可能性があるからである。通常は白色の光を使用する。 The type of the light source (1) is not particularly limited, and a fluorescent lamp, an incandescent lamp, a light emitting diode, or the like can be used. The number of the light sources (1) to be arranged is appropriately selected depending on the type of the light source (1), but at least the number capable of uniformly irradiating the entire surface of the first polarizing plate is required. The light color is not particularly limited, but it is preferable to use a light color. This is because the first polarizing plate (2) and the second polarizing plate (3) are orthogonal to each other, so that when dark colors are used, light may be hardly detected with the naked eye. Usually white light is used.
　光源（１）の輝度は、８０００ｃｄ／ｍ２以上であることが好ましく、１００００ｃｄ／ｍ２以上であることがより好ましい。これにより、直交する偏光板から光が透過する箇所がより明るく強調されるため、より迅速且つ正確にディスプレイ用ガラス基板の輝度ムラの評価を行うことができるからである。 Brightness of the light source (1) is preferably 8000 cd / m 2 or more, more preferably 10000 cd / m 2 or more. This is because the portion where light is transmitted from the orthogonal polarizing plate is emphasized more brightly, so that the luminance unevenness of the glass substrate for display can be evaluated more quickly and accurately.
　光源（１）は、図２に示す通り、第１の偏光板（２）と接触するように配置されるのが好ましい。ディスプレイパネルを作成した状態により近い状態でディスプレイ用ガラス基板の輝度ムラを評価することができ、より正確にディスプレイ用ガラス基板の輝度ムラの評価を行うことができるからである。 The light source (1) is preferably arranged so as to be in contact with the first polarizing plate (2) as shown in FIG. This is because the luminance unevenness of the display glass substrate can be evaluated in a state closer to the state in which the display panel is created, and the luminance unevenness of the display glass substrate can be more accurately evaluated.
　第１の偏光板（２）は、平面視略矩形状の板状体であって、図２の通り、偏光フィルム（２１）と板状透明体（２２）とからなり、板状透明体（２２）に偏光フィルム（２１）を貼着することによって構成されている。第１の偏光板（２）の大きさは、輝度ムラの評価を行うディスプレイ用ガラス基板（４）の大きさ以上であることが好ましく、少なくとも偏光フィルム（２１）がディスプレイ用ガラス基板（４）の輝度ムラ評価範囲以上であることを要する。第１の偏光板（２）は、板状透明体（２２）が光源（１）側で、偏光フィルム（２１）がディスプレイ用ガラス基板（４）側となるように配置される。板状透明体（２２）が有する歪みの影響を受けずに、ディスプレイ用ガラス基板（４）による輝度ムラのみを評価するためである。 The first polarizing plate (2) is a plate-like body having a substantially rectangular shape in plan view, and is composed of a polarizing film (21) and a plate-like transparent body (22) as shown in FIG. It is comprised by sticking a polarizing film (21) to 22). The size of the first polarizing plate (2) is preferably equal to or larger than the size of the glass substrate for display (4) for evaluating the luminance unevenness, and at least the polarizing film (21) is the glass substrate for display (4). It is necessary to be within the luminance unevenness evaluation range of The first polarizing plate (2) is disposed such that the plate-like transparent body (22) is on the light source (1) side and the polarizing film (21) is on the display glass substrate (4) side. This is because only the luminance unevenness due to the glass substrate for display (4) is evaluated without being affected by the distortion of the plate-like transparent body (22).
　板状透明体（２２）は、剛性が高く変形しにくい材質であることを要し、板ガラスや硬質プラスチック等を使用することができる。板状透明体（２２）の板厚は、選択される材質の剛性によって適宜選択されるが、少なくとも本発明に係る評価方法の使用時に変形しない程度の板厚を有することが好ましい。例えば材質に板ガラスを選択した場合は、板厚は０．５ｍｍ以上が好ましい。板状透明体（２２）は、少なくとも偏光フィルム（２１）以上の大きさを要する。 The plate-like transparent body (22) needs to be a material having high rigidity and is difficult to be deformed, and plate glass, hard plastic, or the like can be used. The plate thickness of the plate-like transparent body (22) is appropriately selected depending on the rigidity of the selected material, but it is preferable that the plate-like transparent body (22) has a plate thickness that does not deform at least when the evaluation method according to the present invention is used. For example, when plate glass is selected as the material, the plate thickness is preferably 0.5 mm or more. The plate-like transparent body (22) needs to be at least as large as the polarizing film (21).
　第２の偏光板（３）は、第１の偏光板（２）と同様、平面視略矩形状の板状体であって、図２の通り、偏光フィルム（３１）と板状透明体（３２）とからなり、板状透明体（３２）に偏光フィルム（３１）を貼着することによって構成されている。第２の偏光板（３）の大きさは、第１の偏光板（２）と同様であり、通常は第１の偏光板（２）と同一とされる。第２の偏光板（３）は、偏光フィルム（３１）がディスプレイ用ガラス基板（４）側となるように配置される。 Similar to the first polarizing plate (2), the second polarizing plate (3) is a plate-like body having a substantially rectangular shape in plan view. As shown in FIG. 2, the polarizing plate (31) and the plate-like transparent body ( 32), and is configured by sticking a polarizing film (31) to a plate-like transparent body (32). The size of the second polarizing plate (3) is the same as that of the first polarizing plate (2), and is usually the same as that of the first polarizing plate (2). The second polarizing plate (3) is arranged so that the polarizing film (31) is on the display glass substrate (4) side.
　ディスプレイ用ガラス基板（４）は、珪酸塩ガラスが用いられ、好ましくはシリカガラス、ホウ珪酸ガラスが用いられ、最も好ましくは無アルカリホウ珪酸ガラスが用いられる。ディスプレイ用ガラス基板（４）にアルカリ成分が含有されていると、アルカリ成分が溶出し、ＴＦＴが損傷するおそれがある。尚、ここで無アルカリホウ珪酸ガラスとは、アルカリ成分が実質的に含まれていないガラスのことであって、具体的には、アルカリ成分が１０００ｐｐｍ以下のガラスのことである。本発明でのアルカリ成分の含有量は、好ましくはアルカリ成分が５００ｐｐｍ以下であり、より好ましくはアルカリ成分が３００ｐｐｍ以下である。 The glass substrate for display (4) is made of silicate glass, preferably silica glass or borosilicate glass, most preferably non-alkali borosilicate glass. When an alkali component is contained in the glass substrate for display (4), the alkali component is eluted and the TFT may be damaged. Here, the alkali-free borosilicate glass is a glass that does not substantially contain an alkali component, and specifically, a glass having an alkali component of 1000 ppm or less. The content of the alkali component in the present invention is preferably 500 ppm or less, more preferably 300 ppm or less of the alkali component.
　ディスプレイ用ガラス基板（４）は、平面視略矩形状の板状体であって、板厚が０．０１ｍｍ～１．１ｍｍであることが好ましい。０．０１ｍｍよりも薄すぎると光の干渉や評価対象ディスプレイ用ガラス基板の変形による内部歪などによる影響を受け易く、１．１ｍｍよりも厚すぎると評価時の輝度が低下するからである。より好ましい板厚は０．１ｍｍ～０．７ｍｍ、さらに好ましい板厚は０．１ｍｍ～０．５ｍｍである。 The glass substrate for display (4) is a plate-like body having a substantially rectangular shape in plan view, and preferably has a plate thickness of 0.01 mm to 1.1 mm. This is because if the thickness is less than 0.01 mm, it is easily affected by light interference or internal distortion due to deformation of the glass substrate for display to be evaluated, and if it is too thick, the luminance at the time of evaluation decreases. A more preferable plate thickness is 0.1 mm to 0.7 mm, and a further preferable plate thickness is 0.1 mm to 0.5 mm.
　ディスプレイ用ガラス基板（４）の１辺の長さは、９００ｍｍ以上であることが好ましい。輝度ムラが発生し易い大型ディスプレイに用いられるガラス基板の輝度ムラを評価することができるからである。 The length of one side of the glass substrate for display (4) is preferably 900 mm or more. This is because it is possible to evaluate the luminance unevenness of the glass substrate used in a large display in which luminance unevenness is likely to occur.
　本発明に使用されるディスプレイ用ガラス基板（４）は、ロールアウト法、フロート法、スリットダウン法、オーバーフローダウンドロー法等、公知の方法によって成形することができる。中でも、オーバーフローダウンドロー法によって成形されていることが好ましい。オーバーフローダウンドロー法は、成形時にガラス板の両面が、成形部材と接触しない成形法であり、得られたガラスフィルムの両面（透光面）には傷が生じ難く、研磨しなくても高い表面品位を得ることができるからである。 The glass substrate for display (4) used in the present invention can be formed by a known method such as a roll-out method, a float method, a slit down method, an overflow down draw method or the like. Especially, it is preferable to shape | mold by the overflow downdraw method. The overflow down draw method is a molding method in which both sides of the glass plate do not come into contact with the molding member during molding, and both surfaces (translucent surface) of the obtained glass film are hardly damaged and have a high surface without being polished. This is because quality can be obtained.
　本発明に係るディスプレイ用ガラス基板の評価方法においては、第１の偏光板（２）とディスプレイ用ガラス基板（４）、及び第２の偏光板（３）とディスプレイ用ガラス基板（４）とを面接触させる。仮にこれらを離間させると、第１の偏光板（２）、ディスプレイ用ガラス基板（４）、及び第２の偏光板（３）の表面での散乱光が第２の偏光板（３）を透過するようになり、評価面のコントラストが低下するため、ディスプレイ用ガラス基板の輝度ムラ評価を迅速且つ正確に行うことができない。本発明では面接触させることによりこのような散乱光を除くことができるので、ディスプレイ用ガラス基板の輝度ムラ評価を迅速且つ正確に行うことができる。 In the method for evaluating a glass substrate for display according to the present invention, the first polarizing plate (2) and the glass substrate for display (4), and the second polarizing plate (3) and the glass substrate for display (4) are used. Make surface contact. If these are separated, the scattered light on the surfaces of the first polarizing plate (2), the glass substrate for display (4), and the second polarizing plate (3) is transmitted through the second polarizing plate (3). As a result, the contrast of the evaluation surface is lowered, so that the luminance unevenness evaluation of the glass substrate for display cannot be performed quickly and accurately. In the present invention, since such scattered light can be removed by surface contact, the luminance unevenness evaluation of the glass substrate for display can be performed quickly and accurately.
　本発明に係るディスプレイ用ガラス基板の評価方法においては、図３に示す通り、評価位置は第２の偏光板（３）の真正面ではなく、上下方向、及び、左右方向に或る程度視野角を有する方向からディスプレイ用ガラス基板（４）の輝度ムラの評価を行うことが好ましい。第２の偏光板（３）の真正面からでは輝度ムラを評価しにくく、光源（１）に対して視野角を有する方が（斜めから評価を行った方が）、評価面のコントラストは変化せず平均的な輝度が向上するため、肉眼で輝度ムラを評価し易くなるからである。上下方向、及び、左右方向に１０°～８０°の視野角を有する方向から評価することが好ましく、３０°～６０°の視野角を有する方向から評価することがより好ましい。 In the method for evaluating a glass substrate for display according to the present invention, as shown in FIG. 3, the evaluation position is not directly in front of the second polarizing plate (3), but has a certain viewing angle in the vertical and horizontal directions. It is preferable to evaluate the luminance unevenness of the glass substrate for display (4) from the direction in which it is present. It is difficult to evaluate luminance unevenness from the front of the second polarizing plate (3), and the contrast of the evaluation surface changes when the viewing angle is relative to the light source (1) (when the evaluation is performed obliquely). This is because the average luminance is improved, and it becomes easy to evaluate luminance unevenness with the naked eye. Evaluation is preferably performed from a direction having a viewing angle of 10 ° to 80 ° in the vertical direction and the horizontal direction, and more preferably evaluated from a direction having a viewing angle of 30 ° to 60 °.
　本発明に係るディスプレイ用ガラス基板の評価方法は、周囲からの反射光が存在すると適切な輝度ムラの評価を行いにくくなることから、評価環境が暗所であることが好ましく、暗室であることがより好ましい。 The evaluation method for a glass substrate for a display according to the present invention makes it difficult to evaluate an appropriate luminance unevenness when there is reflected light from the surroundings. Therefore, the evaluation environment is preferably a dark place and is a dark room. More preferred.
　本発明に係るディスプレイ用ガラス基板の評価方法において、第１の偏光板（２）、第２の偏光板（３）、及びディスプレイ用ガラス基板（４）が立設されていることが好ましい。ディスプレイ用ガラス基板（４）の輝度ムラの評価は、近くの位置からは判定しにくく、離れた位置からの方がより正確に行うことができるため、第１の偏光板（２）、第２の偏光板（３）、及びディスプレイ用ガラス基板（４）を立設させた方が、図４に示す通り水平に載置した場合より離れた位置からディスプレイ用ガラス基板（４）の輝度ムラの判定を行うことができるからである。 In the method for evaluating a glass substrate for display according to the present invention, it is preferable that the first polarizing plate (2), the second polarizing plate (3), and the glass substrate for display (4) are erected. The evaluation of the luminance unevenness of the glass substrate for display (4) is difficult to determine from a nearby position, and can be performed more accurately from a distant position. Therefore, the first polarizing plate (2) and the second polarizing plate When the polarizing plate (3) and the display glass substrate (4) are erected, the luminance unevenness of the display glass substrate (4) from a position distant from the case of being horizontally placed as shown in FIG. This is because the determination can be made.
　なお、本発明に係るディスプレイ用ガラス基板の評価方法は、図４に示す通り、光源（１）、第１の偏光板（２）、ディスプレイ用ガラス基板（４）、第２の偏光板（３）を順に水平に積み重ねるように積層させ、第２の偏光板（３）から間隔を空けて上方から輝度ムラの評価を行うこともできる。当該形態の方法を使用する場合は、第１の偏光板（２）、ディスプレイ用ガラス基板（４）、第２の偏光板（３）が重力や外力などにより撓むのをより確実に防止することができる。 In addition, as shown in FIG. 4, the evaluation method of the glass substrate for a display which concerns on this invention is a light source (1), a 1st polarizing plate (2), a glass substrate for a display (4), a 2nd polarizing plate (3 ) In order to be stacked horizontally, and the brightness unevenness can be evaluated from above at a distance from the second polarizing plate (3). When using the method of the said form, it prevents more reliably that the 1st polarizing plate (2), the glass substrate for displays (4), and the 2nd polarizing plate (3) are bent by gravity, external force, etc. be able to.
　本発明に係るディスプレイ用ガラス基板の評価方法において、第２の偏光板（３）から２～６ｍ離間した位置から評価することが好ましい。ディスプレイ用ガラス基板（４）の輝度ムラを確認し易く、また、実際に使用者が薄型テレビを視聴する距離からより正確にディスプレイ用ガラス基板（４）の輝度ムラの評価を行うことができるからである。２ｍより近づくと、視野角に起因する光抜けが大きくなり、また、６ｍよりも遠くなると評価者（５）の視力によっては肉眼では評価しにくくなるため、いずれの場合もディスプレイ用ガラス基板（４）の輝度ムラが見えにくくなるため好ましくない。 In the method for evaluating a glass substrate for display according to the present invention, it is preferable to evaluate from a position 2 to 6 m away from the second polarizing plate (3). It is easy to confirm the luminance unevenness of the glass substrate for display (4), and the luminance unevenness of the glass substrate for display (4) can be more accurately evaluated from the distance that the user actually views the thin TV. It is. When the distance is closer than 2 m, light leakage due to the viewing angle increases, and when the distance is longer than 6 m, it is difficult to evaluate with the naked eye depending on the visual acuity of the evaluator (5). ) Is not preferable because it is difficult to see the luminance unevenness.
　ディスプレイ用ガラス基板（４）は、液晶ディスプレイ用ガラス基板であることが好ましい。より輝度ムラの発生し易い液晶ディスプレイに用いられるガラス基板の輝度ムラを評価することができるからである。 The glass substrate for display (4) is preferably a glass substrate for liquid crystal display. This is because it is possible to evaluate the luminance unevenness of the glass substrate used in the liquid crystal display in which the luminance unevenness is more likely to occur.
　さらに光源（１）は、液晶用のバックライトユニットを使用することが好ましい。液晶ディスプレイに使用されるものと同一の光源、同一のガラス基板を使用することにより、液晶パネルを作成した状態により近い状態でディスプレイ用ガラス基板の輝度ムラを評価することができ、より正確にディスプレイ用ガラス基板の輝度ムラの評価を行うことができるからである。例えば、冷陰極線管の蛍光灯や、白色ダイオードが複数配設された液晶用バックライトユニットが好ましく用いられる。 Furthermore, the light source (1) preferably uses a liquid crystal backlight unit. By using the same light source and the same glass substrate as those used for the liquid crystal display, it is possible to evaluate the luminance unevenness of the glass substrate for display in a state closer to the state in which the liquid crystal panel is created, and to display the display more accurately. This is because the luminance unevenness of the glass substrate can be evaluated. For example, a fluorescent lamp of a cold cathode ray tube or a liquid crystal backlight unit provided with a plurality of white diodes is preferably used.
　本発明に係るディスプレイ用ガラス基板の評価方法は、評価者が肉眼の目視判定で行う形態について説明を行ったが、公知のＣＣＤカメラ等の画像処理装置を使用することによって、輝度を測定・解析し、輝度ムラの判定を機械的に行うことも可能である。 The method for evaluating a glass substrate for a display according to the present invention has been described with respect to an embodiment in which an evaluator performs visual determination with the naked eye. By using a known image processing apparatus such as a CCD camera, luminance is measured and analyzed. However, it is also possible to determine luminance unevenness mechanically.
　本発明に係るディスプレイ用ガラス基板（４）の評価方法は、全数調査、抜き取り調査のいずれの形態でも行うことができる。全数調査を行う場合は、評価後、良品と判断されたディスプレイ用ガラス基板（４）に関しては、基板両面の研磨を行った後、洗浄、乾燥、梱包を行う。フロート法で成形されたディスプレイ用ガラス基板（４）の場合は、研磨工程を必要とするため、全数調査を行うことが好ましい。一方、オーバーフローダウンドロー法で成形されたディスプレイ用ガラス基板の場合は、研磨工程を必要としないため、抜き取り調査を行うことが好ましい。抜き取り調査は、所定期間ごとに所定数のディスプレイ用ガラス基板（４）を製造ラインから抜き取り、本発明に係るディスプレイ用ガラス基板（４）の評価方法を使用して良品の判定を行う。抜き取り調査によってロット毎の輝度ムラの状態を判断し、評価に直接使用したディスプレイ用ガラス基板（４）に関しては、良品、不良品を問わず製品としては使用せず、再溶融され、再成形される。 The evaluation method of the glass substrate for display (4) according to the present invention can be performed in any form of total number survey and sampling survey. When conducting a 100% survey, the display glass substrate (4), which has been determined to be non-defective after the evaluation, is cleaned, dried, and packed after both surfaces of the substrate are polished. In the case of the glass substrate for display (4) formed by the float process, since a polishing process is required, it is preferable to conduct a complete survey. On the other hand, in the case of a glass substrate for display formed by the overflow downdraw method, it is preferable to conduct a sampling survey because a polishing step is not required. In the sampling survey, a predetermined number of display glass substrates (4) are extracted from the production line every predetermined period, and a non-defective product is determined by using the display glass substrate (4) evaluation method according to the present invention. The brightness unevenness of each lot is judged by sampling and the glass substrate for display (4) used directly for evaluation is not used as a product regardless of whether it is good or defective, but is remelted and remolded. The
　図５は、本発明に係るディスプレイ用ガラス基板に使用される成形法の一例を示す図である。 FIG. 5 is a diagram showing an example of a forming method used for the glass substrate for display according to the present invention.
　本発明に係るディスプレイ用ガラス基板は、以下の製造方法によって作製することができる。 The glass substrate for display according to the present invention can be produced by the following production method.
　断面が楔型の成形体（６）の下端部（６１）から流下した直後のガラスリボン（Ｇ）は、冷却ローラ（７）によって幅方向の収縮が規制されながら下方へ引き伸ばされて所定の厚みまで薄くなる。次に、前記所定厚みに達したガラスリボン（Ｇ）を徐冷炉（アニーラ）で徐々に冷却し、ガラスリボン（Ｇ）の熱歪を除き、ガラスリボン（Ｇ）を所定寸法に切断した後、端縁部を切断し、ディスプレイ用ガラス基板（４）が成形される。ガラスリボン（Ｇ）の切断については、先に端縁部の切断を行い、その後に所定寸法に切断を行ってもよい。 The glass ribbon (G) immediately after flowing down from the lower end portion (61) of the wedge-shaped molded body (6) is stretched downward while the shrinkage in the width direction is restricted by the cooling roller (7) to have a predetermined thickness. Until it gets thinner. Next, the glass ribbon (G) having reached the predetermined thickness is gradually cooled in a slow cooling furnace (annealer), the thermal distortion of the glass ribbon (G) is removed, the glass ribbon (G) is cut into a predetermined dimension, An edge part is cut | disconnected and the glass substrate (4) for a display is shape | molded. Regarding the cutting of the glass ribbon (G), the edge portion may be cut first, and then cut to a predetermined dimension.
　成形され切断されたディスプレイ用ガラス基板（４）を使用し、第１の偏光板（２）とディスプレイ用ガラス基板（４）、及び第２の偏光板（３）とディスプレイ用ガラス基板（４）とを面接触させる。その後、蛍光灯等の光源から第１の偏光板（２）に対して光の照射を行い、第１の偏光板（２）とディスプレイ用ガラス基板（４）、及び第２の偏光板（３）とを通過する光の量の変化による輝度ムラの有無を、第２の偏光板（４）側から観察することによってディスプレイ用ガラス基板（４）の輝度ムラの評価を行う。輝度ムラとして、縦横斜め方向といった方向性のあるムラや、周囲と輝度の異なる不定形の領域と認識されるムラ等、比較的狭い領域で明暗差が確認できる場合、不良と判定する。判定基準として限度見本を使用する。全数調査を行う場合、良品と判定が行われたディスプレイ用ガラス基板（４）については、その後に加工、研磨、洗浄、梱包等の工程を経た後、出荷される。不良品と判定が行われたディスプレイ用ガラス基板（４）については、再溶融され、再成形後に再び輝度ムラの評価を行う。抜き取り調査を行う場合は、抽出されたディスプレイ用ガラス基板（４）が良品と判定された場合は、該当ロット内の他のディスプレイ用ガラス基板（４）について出荷作業を行う。判定に使用したディスプレイ用ガラス基板（４）については出荷を行わず、再溶融される。不良品と判定された場合は、該当ロット内のすべてのディスプレイ用ガラス基板（４）は、出荷されず再溶融される。溶融条件、成形条件等の操業条件の見直しを行い、所定ロット毎に輝度ムラの評価を行い、ディスプレイ用ガラス基板（４）が良品と判定されるまで条件の見直しを継続する。 Using the molded and cut glass substrate for display (4), the first polarizing plate (2) and the glass substrate for display (4), and the second polarizing plate (3) and the glass substrate for display (4) And surface contact. Thereafter, the first polarizing plate (2) is irradiated with light from a light source such as a fluorescent lamp, and the first polarizing plate (2), the glass substrate for display (4), and the second polarizing plate (3 ) Is observed from the second polarizing plate (4) side to evaluate the luminance unevenness of the glass substrate for display (4). When the brightness unevenness can be confirmed in a relatively narrow area, such as unevenness with directionality such as vertical and horizontal oblique directions, or unevenness recognized as an irregular area with different brightness from the surroundings, it is determined as defective. Use limit samples as criteria. When conducting a complete survey, the glass substrate for display (4) that has been determined to be non-defective is shipped after undergoing processes such as processing, polishing, washing, and packaging. The glass substrate for display (4) determined to be defective is remelted, and luminance unevenness is evaluated again after re-molding. In the case of conducting a sampling survey, if it is determined that the extracted display glass substrate (4) is a non-defective product, a shipping operation is performed on the other display glass substrate (4) in the corresponding lot. The display glass substrate (4) used for the determination is remelted without shipping. When it is determined as a defective product, all the display glass substrates (4) in the corresponding lot are remelted without being shipped. The operating conditions such as the melting conditions and the molding conditions are reviewed, the luminance unevenness is evaluated for each predetermined lot, and the conditions are continuously reviewed until the display glass substrate (4) is determined to be non-defective.
　上述の製造方法によって、ディスプレイパネルに組み込んだ場合に輝度ムラの発生を防止することを可能とするディスプレイ用ガラス基板（２）とすることができる。 The glass substrate for display (2) that can prevent the occurrence of uneven brightness when incorporated in a display panel can be obtained by the above-described manufacturing method.
　本発明は、ディスプレイ用ガラス基板の輝度ムラの発生の有無を評価するのに好適に使用することができる。 The present invention can be suitably used to evaluate the presence or absence of occurrence of luminance unevenness in a display glass substrate.
１　　光源
２　　第１の偏光板
２１　偏光フィルム
２２　板状透明体
３　　第２の偏光板
３１　偏光フィルム
３２　板状透明体
４　　ディスプレイ用ガラス基板
５　　評価者
６　　成形体
７　　冷却ローラ DESCRIPTION OF SYMBOLS 1 Light source 2 1st polarizing plate 21 Polarizing film 22 Plate-shaped transparent body 3 2nd polarizing plate 31 Polarizing film 32 Plate-shaped transparent body 4 Glass substrate 5 for display Evaluator 6 Molded body 7 Cooling roller

Claims (12)

  1. 　光源から光が照射される方向に配置された第１の偏光板と、該第１の偏光板の偏光軸と直交するように配置された第２の偏光板との間にディスプレイ用ガラス基板を挿入し、前記光源から前記第１の偏光板、前記ディスプレイ用ガラス基板、及び前記第２の偏光板とを透過する光を検知し、輝度ムラを評価するディスプレイ用ガラス基板の輝度ムラ評価方法であって、
    　前記ディスプレイ用ガラス基板を、前記第１の偏光板及び前記第２の偏光板に面接触させることを特徴とするディスプレイ用ガラス基板の輝度ムラ評価方法。     A glass substrate for display is disposed between a first polarizing plate arranged in a direction in which light is emitted from a light source and a second polarizing plate arranged to be orthogonal to the polarization axis of the first polarizing plate. Inserting and detecting the light transmitted from the light source through the first polarizing plate, the display glass substrate, and the second polarizing plate, and evaluating the luminance unevenness, the luminance unevenness evaluation method of the display glass substrate There,
    The method for evaluating luminance unevenness of a glass substrate for display, comprising bringing the glass substrate for display into surface contact with the first polarizing plate and the second polarizing plate.
  2. 　前記光源と前記第１の偏光板とが、接触していることを特徴とする請求項１に記載のディスプレイ用ガラス基板の輝度ムラ評価方法。 The method for evaluating unevenness of luminance of a glass substrate for display according to claim 1, wherein the light source and the first polarizing plate are in contact with each other.
  3. 　前記光源の輝度が、８０００ｃｄ／ｍ２以上であることを特徴とする請求項１または２に記載のディスプレイ用ガラス基板の輝度ムラ評価方法。 The luminance unevenness evaluation method for a glass substrate for display according to claim 1 or 2, wherein the luminance of the light source is 8000 cd / m 2 or more.
  4. 　前記ディスプレイ用ガラス基板の板厚が、０．０１ｍｍ～１．１ｍｍであることを特徴とする請求項１～３のいずれかに記載のディスプレイ用ガラス基板の輝度ムラ評価方法。 The method for evaluating luminance unevenness of a glass substrate for display according to any one of claims 1 to 3, wherein the thickness of the glass substrate for display is 0.01 mm to 1.1 mm.
  5. 　前記ディスプレイ用ガラス基板の１辺の長さが、９００ｍｍ以上であることを特徴とする請求項１～４のいずれかに記載のディスプレイ用ガラス基板の輝度ムラ評価方法。 The method for evaluating luminance unevenness of a glass substrate for display according to any one of claims 1 to 4, wherein a length of one side of the glass substrate for display is 900 mm or more.
  6. 　前記第２の偏光板から１０°～８０°視野角を有する位置から評価することを特徴とする請求項１～５のいずれかに記載のディスプレイ用ガラス基板の輝度ムラ評価方法。 6. The luminance unevenness evaluation method for a glass substrate for display according to claim 1, wherein the evaluation is performed from a position having a viewing angle of 10 ° to 80 ° from the second polarizing plate.
  7. 　前記第１の偏光板、前記第２の偏光板、及び前記ディスプレイ用ガラス基板が立設されていることを特徴とする請求項１～６のいずれかに記載のディスプレイ用ガラス基板の輝度ムラ評価方法。 The luminance unevenness evaluation of a display glass substrate according to any one of claims 1 to 6, wherein the first polarizing plate, the second polarizing plate, and the display glass substrate are erected. Method.
  8. 　前記第２の偏光板から２～６ｍ離間した位置から評価することを特徴とする請求項１～７のいずれかに記載のディスプレイ用ガラス基板の輝度ムラ評価方法。 The method for evaluating luminance unevenness of a glass substrate for display according to any one of claims 1 to 7, wherein the evaluation is performed from a position 2 to 6 m away from the second polarizing plate.
  9. 　前記ディスプレイ用ガラス基板が、液晶ディスプレイ用ガラス基板であることを特徴とする請求項１～８のいずれかに記載のディスプレイ用ガラス基板の輝度ムラ評価方法。 The method for evaluating luminance unevenness of a glass substrate for display according to any one of claims 1 to 8, wherein the glass substrate for display is a glass substrate for liquid crystal display.
  10. 　前記光源は、液晶ディスプレイ用バックライトユニットであることを特徴とする請求項９に記載のディスプレイ用ガラス基板の輝度ムラ評価方法。 10. The method for evaluating unevenness of luminance of a glass substrate for display according to claim 9, wherein the light source is a backlight unit for liquid crystal display.
  11. 　成形後ガラスリボンを搬送しつつ、所定長の長さに切り出した後に端縁部を切断することによってディスプレイ用ガラス基板を作製する第１の工程と、
    　光源から光が照射される方向に配置された第１の偏光板と、該第１の偏光板の偏光軸と直交するように配置された第２の偏光板との間に前記第１の工程で作製された前記ディスプレイ用ガラス基板を挿入した後に夫々面接触させる第２の工程と、
    　前記光源から前記第１の偏光板、前記ディスプレイ用ガラス基板、及び前記第２の偏光板とを透過する光を検知し、輝度ムラを評価する第３の工程と、
    　評価された前記ディスプレイ用ガラス基板を良品と不良品とに選別する第４の工程とを有することを特徴とするディスプレイ用ガラス基板の製造方法。     A first step of producing a glass substrate for display by cutting the edge portion after cutting into a predetermined length while conveying the glass ribbon after molding;
    The first step between the first polarizing plate arranged in the direction in which light is emitted from the light source and the second polarizing plate arranged so as to be orthogonal to the polarization axis of the first polarizing plate. A second step of contacting the surfaces after inserting the display glass substrate made in
    A third step of detecting light transmitted through the first polarizing plate, the glass substrate for display, and the second polarizing plate from the light source, and evaluating luminance unevenness;
    A method for producing a glass substrate for display, comprising: a fourth step of sorting the evaluated glass substrate for display into a non-defective product and a defective product.
  12. 　請求項１１に記載された製造方法によって製造されたディスプレイ用ガラス基板。 A glass substrate for display manufactured by the manufacturing method according to claim 11.
PCT/JP2009/060529 2008-06-17 2009-06-09 Method for evaluating luminance nonuniformity of display glass substrate, method for manufacturing display glass substrate, and display glass substrate wherein luminance nonuniformity is not easily generated WO2009154105A1 (en)

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