JP5251087B2 - Manufacturing method of liquid crystal display panel - Google Patents

Description

This invention relates to a method of manufacturing a liquid crystal display panel.

  In recent years, mobile devices such as mobile phones and PDAs (Personal Digital Assistance) have been used for FPD (Flat Panel Display) modules that use liquid crystal display panels, organic electroluminescence display panels, etc. It is used as a display. The demand for miniaturization and thinning is extremely strict for the display of this mobile device, and further thinning is demanded for the FPD module.

  In the FPD, a glass substrate is suitably used as the transparent substrate. However, when the thickness of the glass substrate is reduced in order to reduce the thickness of the FPD, there is a problem that the glass substrate is easily broken by an external force.

As a method of increasing the mechanical strength of the glass substrate, a chemical method of immersing in an alkali molten salt bath at a temperature below the transition point as shown in Patent Document 1, heating as shown in Patent Document 2, and the like. There is a physical method by cooling.
JP 7-318915 A JP 2004-91311 A

  Any of the above-described methods requires a large process and increases the number of manufacturing steps.

An object of the present invention is to provide a method of manufacturing a liquid crystal display panel that can be manufactured by a reduced number of steps by a simple process.

According to a first aspect of the present invention, there is provided a liquid crystal display panel manufacturing method comprising: a liquid crystal display cell including a glass substrate placed on a table; and a polarizing sheet tape wound and housed above the table. And a relay roller that circulates the polarizing sheet tape fed out from the feeding reel, the leading end of the polarizing sheet tape is fed out from the feeding reel, and the leading end of the polarizing sheet tape Passes above the peripheral surface of the relay roller and one end of the glass substrate, and the leading end of the polarizing sheet tape is pressed onto the other end of the glass substrate with a predetermined pressure by a pressing roller and adhered. The pressing roller travels from the other end of the glass substrate to the one end while pressing the polarizing sheet tape against the glass substrate. The other end portion on the glass substrate when the polarizing sheet tape is adhered to the entire surface of the glass substrate and a position other than the other end portion on the glass substrate is pressed by the pressing roller. The length of the polarizing sheet tape from the relay roller to the relay roller is determined from the other end on the glass substrate when the position of the other end on the glass substrate is pressed by the pressing roller. It is longer than the length of the polarizing sheet tape to the roller, and the relay roller is disposed at a position downstream of the pressing roller in the running direction and higher than the upper surface of the glass substrate .

Method of manufacturing a liquid crystal display panel of claim 2, wherein in the method of manufacturing a liquid crystal display panel of claim 1, wherein the polarizing sheet tape, a polarizing layer, an adhesive layer, and release paper tape, the, the A take-up reel that winds up the release paper tape separated from the polarizing sheet tape on the peripheral surface of the relay roller, and the release sheet on the peripheral surface of the relay roller from the polarizing sheet tape fed out from the supply reel; The paper tape is separated .

Method of manufacturing a liquid crystal display panel of claim 3 is a method of manufacturing a liquid crystal display panel of claim 1, wherein the glass substrate is a pair of glass substrates sandwiching a liquid crystal between, equipped with the pressing roller the has been and cutters, polarizing sheet disconnect the polarizing sheet tape is stuck has a side that sandwich the liquid crystal of the pair of glass substrates to each outer surface of the opposite side, the light absorption axis parallel to each other In addition, they are respectively attached in a state where tension is applied in a direction parallel to the direction of the light absorption axis.

According to the present invention, a method of manufacturing the liquid crystal display panel can be manufactured by a reduced number of steps by a simple process.

  FIG. 1A is a schematic sectional view showing a polarizing sheet as an embodiment of the compressive stress applying sheet of the present invention, FIG. 1B is a side view showing a liquid crystal display panel using the polarizing sheet, and FIG. It is explanatory drawing which showed the deformation | transformation state when a bending load is applied to the said liquid crystal display panel.

  In the polarizing sheet 1 in this embodiment, a protective sheet 13 is attached to one main surface of a three-layer film in which a polarizing film 11 is sandwiched between a pair of TAC (Tri Acetyl Cellulose) films 12 and 12, and the other A release sheet 15 made of PET (polyethylene terephthalate) is attached to the main surface of the film through an adhesive layer 14 made of acrylic resin. Therefore, the polarizing sheet 1 has elasticity as a laminated film in which resin layers are laminated.

  The polarizing sheet 1 described above has arrows A and B whose opposite ends are opposite to each other on the outer surfaces of the rectangular glass substrates 21 and 22 that sandwich the liquid crystal (not shown) of the liquid crystal display cell 2. They are attached in a state where they are pulled in the direction, that is, in a state where a tensile stress is applied. At the time of sticking, the pulling direction of the polarizing sheet 1 and the longitudinal direction of the rectangular glass substrates 21 and 22 are matched.

  Here, as for each polarizing sheet 1 and 1 stuck on the outer surface of the glass substrates 21 and 22, the sheet itself tends to shrink in the directions of arrows C and D due to its elasticity. Compressive stresses α1 and α2 acting in opposite directions to 22 are generated. That is, the polarizing sheets 1 and 1 are compressive stress-added sheets for the glass substrates 21 and 22 that are adhered.

  Note that the polarizing sheet 1 is elastically deformed to some extent by being pulled, thereby changing optical characteristics such as a polarizing action. However, by setting the initial characteristic value before sticking of the polarizing sheet 1 to a characteristic value that anticipates the amount of change in optical characteristics due to tensile elastic deformation, it is caused by changes in optical characteristics such as polarization due to deformation. The occurrence of defects such as display defects can be substantially avoided.

  As shown in FIG. 1 (c), an external force F is applied to the liquid crystal display panel adhered to the outer surfaces of the glass substrates 21 and 22 in a state where the pair of polarizing sheets 1 and 1 are pulled with a predetermined range of tension. When acting, tensile stresses β1 and β2 and compressive stresses α3 and α4 acting in opposite directions are generated on the glass substrates 21 and 22, respectively.

  At this time, if the polarizing sheet 1 is normally stuck without being pulled, the glass substrates 21 and 22 having low tensile strength may be broken by the tensile stresses β1 and β2. However, in the present embodiment, since the compressive stresses α1 and α2 are respectively applied to the glass substrates 21 and 22 by the polarizing sheet 1 pulled and pasted, the glass substrates 21 and 22 are prevented from being broken.

  That is, when a load F is applied from the outside to a rectangular liquid crystal display panel, the liquid crystal display panel bends along the longitudinal direction as shown in the figure, and the glass substrates 21 and 22 have tensile stress β1 according to the bending load F, β2 and compressive stresses α1 and α2 are also generated along the longitudinal direction. Here, in the present embodiment, since the polarizing sheets 1 and 1 are bonded to each other in the longitudinal direction of the glass substrates 21 and 22 having a rectangular shape, the compressive stresses acting in opposite directions to each other. α1 and tensile stress β1 and compressive stress α2 and tensile stress β2 cancel each other, and the glass substrates 21 and 22 are prevented from being broken.

  In the liquid crystal display panel according to the above-described embodiment, the light absorption axes 1a of the polarizing sheets 1 attached to both surfaces of the two glass substrates 21 and 22 arranged with the liquid crystal layer interposed therebetween are arranged parallel to each other. preferable. In this case, the polarizing sheets 1 are attached to both outer surfaces of the two glass substrates 21 and 22 in a state where tensile stress is applied in the direction along the light absorption axis 1a. According to this structure, since the tension is applied to the two polarizing sheets 1 and 1 in the direction along the light absorption axis 1a, the polarizing sheets 1 and 1 are aligned in the same direction as the arrangement direction of the polymers forming the polarizing film 11 of the polarizing sheet 1. Since tension is applied, the influence of the tension on the polarization characteristics of the polarizing sheet 1 can be substantially eliminated.

  Next, based on FIG. 2 (a), (b), the apparatus and process which stick the said polarizing sheet 1 to the liquid crystal display cell 2 are demonstrated.

  A supply reel 4 is pivotally supported above a table 3 on which the liquid crystal display cell 2 as a work is placed. On the feeding reel 4, a polarizing sheet tape 5 obtained by tape-forming the polarizing sheet 2 is wound and stored. The supply reel 4 includes a brake mechanism (not shown).

  Reference numeral 6 denotes a pressing roller, which is driven to travel in the direction of the arrow parallel to the surface of the table 3 while pressing the fed polarizing sheet tape 5 toward the liquid crystal display cell 2 with a predetermined pressure. The pressing roller 6 is equipped with a chuck mechanism and a cutter (not shown).

A relay roller 7 and a take-up reel 9 for the release paper tape 8 are disposed downstream of the pressing roller 6 in the running direction. The shaft 71 of the relay roller 7 is elastically supported by a position adjusting mechanism (not shown). The position adjustment mechanism adjusts the position of the shaft 71 so that the pressure applied to the shaft 71 is within a substantially constant range. A take-up reel 9, the ratchet mechanism is not shown together to prevent interlocking mechanism and reverse rotation of the supply reel 4 comprising a timing belts or the like for example is equipped.

  First, the liquid crystal display cell 2 is set at a predetermined position on the table 3, and the front end portion of the polarizing sheet tape 5 is pressed with a predetermined pressure by the pressing roller 6 to a predetermined position on the outer surface of the glass substrate 21 facing the front. At the front end of the polarizing sheet tape 5, the release paper tape 8 is separated at the peripheral surface of the relay roller 7, and the adhesive layer 14 (see FIG. 1A) is exposed, and is pressed by the pressure roller 6 with sufficient pressure. As a result, it is firmly fixed to the outer surface of the glass substrate 21 via the adhesive layer 14. In this state, the polarizing sheet tape 5 is stretched while maintaining an intended tension (tension) by the position adjusting mechanism of the relay roller 7.

  Next, as shown in FIG. 2B, the pressing roller 6 is caused to travel in the direction of the arrow parallel to the surface of the table 3 with the polarizing sheet tape 5 pressed against the pressure. At this time, the polarizing sheet tape 5 is unwound from the unwinding reel 4 as much as necessary, but the tension is maintained substantially constant at the above-mentioned desired magnitude by the position adjusting mechanism of the relay roller 7. Thereby, the polarizing sheet tape 5 is stuck to the substantially entire outer surface of the glass substrate 21 while maintaining the above tension.

  Next, the polarizing sheet tape 5 attached by the cutter equipped on the pressing roller 6 is separated, and at the same time, a newly generated tip portion of the polarizing sheet tape 5 is gripped by the chuck mechanism. Then, the pressing roller 6 holding the new tip of the polarizing sheet tape 5 is retracted from the liquid crystal display cell 2, and the desired tension is maintained on the outer surface of the glass substrate 21 on the polarizing sheet 1 shown in FIG. The liquid crystal display cell 2 stuck as it is is taken out.

  Thereafter, a new liquid crystal display cell is set on the table 3, and the pressing roller 6 holding the tip of the polarizing sheet tape 5 is returned to the home position shown in FIG. Then, the chuck mechanism is released in a state where the tip portion is pressed against the new liquid crystal display cell, and the process of attaching the polarizing sheet to the new liquid crystal display cell is started.

  In this embodiment, the liquid crystal display cell 2 as a workpiece is set on the table 3 and the pressing roller 6 is run. However, the liquid crystal display cell is conveyed by belt only by moving the pressing roller to and from the liquid crystal display cell. It is good also as a structure.

  As described above, the liquid crystal display panel of the present embodiment is attached to the outer surfaces of the pair of glass substrates 21 and 22 with the polarizing sheets 1 and 1 made of an elastic material while being pulled with a predetermined tension. Since compressive stress is applied to the glass substrates 21 and 22 by force, the strength against bending load applied to both the front and back surfaces of the liquid crystal display panel is enhanced.

  In addition, since the bending strength of the glass substrates 21 and 22 can be increased by a simple work process of simply attaching the elastic polarizing sheet 1 to the glass substrates 21 and 22 while maintaining tension, even if the glass substrates 21 and 22 are thin, The bending strength can be easily increased with a small number of man-hours, and a liquid crystal display panel excellent in mechanical strength can be produced with a small number of man-hours.

  And the manufacturing process of the liquid crystal display panel concerning this invention is reduced more by setting it as the process which makes the polarizing sheet 1 a tape, and is continuously extended | rolled out and provided on a glass substrate, providing tension | tensile_strength by a roll to roll system. It becomes possible.

  Next, another embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the component same as the said embodiment, and the description is abbreviate | omitted.

  The tempered glass plate of this embodiment is obtained by attaching a transparent reinforcing sheet 20 as a compressive stress applying sheet to one main surface of the glass substrate 10. The transparent reinforcing sheet 20 is a polycarbonate resin sheet excellent in transparency, and in the state where the glass substrate 10 is pulled with a tension that does not deform into a curved shape, the pulling direction is the longitudinal direction of the glass substrate 10 as in the above embodiment. It is made to correspond to a direction and is stuck by the adhesive of acrylic resin.

  As shown in FIG. 3B, the tempered glass plate configured as described above is enhanced in strength against the bending load F by the same mechanism as in the above embodiment. Therefore, the tempered glass plate of the present embodiment is suitable as a glass substrate for FPD such as a liquid crystal display panel and an organic EL (electroluminescence) display because it has a large bending strength and excellent transparency. When applied to a liquid crystal display panel, the liquid crystal may be sandwiched with the main surface on which the transparent reinforcing sheet 20 is adhered as the outer surface, and the polarizing sheet may be adhered on the transparent reinforcing sheet 20. In this case, since the polarizing sheet is normally stuck without applying tension, it is not necessary to consider the shift in optical characteristics due to tensile deformation.

  As described above, the tempered glass of this embodiment is suitably used as an FPD glass substrate such as a liquid crystal display panel or an organic EL display panel because a polycarbonate resin sheet having high transparency is used as a compression stress applying sheet.

In addition, this invention is not limited to said embodiment.
For example, the compressive stress-added sheet may be attached to both the front and back main surfaces of the glass substrate. However, when this is applied as a glass substrate of a liquid crystal display panel or an organic EL display panel, it is necessary to select a material that does not elute impurities into the liquid crystal or organic EL material as the material for the compressive stress application sheet.

(A) is typical sectional drawing which shows the polarizing sheet applied to the liquid crystal display panel as one Embodiment, (b) is a side view which shows the said liquid crystal display panel, (c) is a bending load to the said liquid crystal display panel. It is explanatory drawing which shows the added state. It is explanatory drawing which shows the sticking process of the said polarizing sheet, (a) has shown the sticking start time, (b) has each shown in the middle of sticking. (A) is a side view which shows other embodiment of the tempered glass board of this invention, (b) is explanatory drawing which shows the state which added the bending load to the said tempered glass board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polarizing sheet 1a Light absorption axis 11 Polarizing film 12 TAC film 13 Protective sheet 14 Adhesive layer 15 Release sheet 2 Liquid crystal display cell 21, 22 Glass substrate 3 Table 4 Feeding reel 5 Polarizing sheet tape 6 Pressing roller 7 Relay roller 71 Axis 8 Release sheet tape 9 Take-up reel 10 Glass substrate 20 Transparent reinforcing sheet

Claims (3)

A liquid crystal display cell comprising a glass substrate placed on a table;
A delivery reel provided above the table, in which a polarizing sheet tape is wound and stored;
A relay roller that circulates the polarizing sheet tape fed from the feeding reel;
Prepare
The leading end portion of the polarizing sheet tape is fed out from the feeding reel, and the leading end portion of the polarizing sheet tape passes above the peripheral surface of the relay roller and one end portion of the glass substrate, and the leading end of the polarizing sheet tape The part is pressed and stuck on the other end of the glass substrate with a predetermined pressure by a pressing roller,
While the pressing roller presses the polarizing sheet tape against the glass substrate, the polarizing sheet tape is adhered to the entire surface of the glass substrate by running from the other end to the one end of the glass substrate. ,
The length of the polarizing sheet tape from the other end on the glass substrate to the relay roller when a position other than the other end on the glass substrate is pressed by the pressing roller is the glass Longer than the length of the polarizing sheet tape from the other end on the glass substrate to the relay roller when pressing the position of the other end on the substrate with the pressing roller,
A method of manufacturing a liquid crystal display panel , wherein the relay roller is disposed at a position downstream of the pressing roller in a traveling direction and higher than an upper surface of the glass substrate . The polarizing sheet tape includes a polarizing layer, an adhesive layer, and a release paper tape,
A winding reel that winds up the release paper tape separated from the polarizing sheet tape on the peripheral surface of the relay roller;
Wherein from the polarizing sheet tape fed out from the supply reel, the method of manufacturing the liquid crystal display panel according to claim 1, characterized in that the separation of the release paper tape peripheral surface of the relay roller. The glass substrate is a pair of glass substrates that sandwich a liquid crystal therebetween,
The cutter is mounted on the pressing roller, the adhered has been polarizing sheet disconnect the polarizing sheet tapes are, each outer surface of the side opposite to the side that sandwich the liquid crystal of said pair of glass substrates, the light-absorbing 2. The method of manufacturing a liquid crystal display panel according to claim 1 , wherein the axes are attached in a state where the axes are parallel to each other and tension is applied in a direction parallel to the direction of the light absorption axis.

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