Patent Application
20120138237
The present invention relates to apparatuses and methods for delaminating an adhesive film, and more particularly to techniques of delaminating a polarizing plate bonded to a liquid crystal display (LCD) panel.
An optical film such as a retarder or a polarizing plate is sometimes bonded to the surface of a display panel. For example, a polarizing plate etc. is bonded to an LCD panel to control liquid crystal by using the function of liquid crystal.
The LCD panel is includes a TFT substrate having thin film transistors (TFTs) etc. formed on a glass substrate, a CF substrate having a color filter (CF) etc. formed on a glass substrate, and a liquid crystal layer enclosed between the TFT substrate and the CF substrate. The TFT substrate is bonded to the CF substrate by a frame-shaped sealant interposed therebetween, and the liquid crystal layer is sealed between these substrates by the sealant.
The LCD panel needs to use light that oscillates only in a predetermined direction, and a polarizing plate configured to allow the light that oscillates only in the predetermined direction to transmit therethrough is bonded to the surface of the LCD panel. More specifically, polarizing plates as films are bonded to those surfaces of the TFT substrate and the CF substrate which are located on the opposite side from the liquid crystal layer, via adhesive layers, respectively.
In manufacturing of LCD devices, an inspection step, such as inspection of appearance and turn-on inspection, is performed after polarizing plates are attached to LCD panels. If any abnormal condition, such as foreign matter caught between the polarizing plate and the panel surface or a shift of the bonding position of the polarizing plate on the panel surface, is detected in this inspection step, it is necessary to delaminate the abnormal polarizing plate from the LCD panel, and then to bond a normal polarizing plate to the LCD panel.
Thus, a method for delaminating such a polarizing plate has been proposed. More specifically, a method for delaminating, e.g., an adhesive film (a polarizing plate) from a bonding surface of a target object (an LCD panel), namely an object from which the adhesion film is to be delaminated, has been disclosed. In this method, a part of the adhesive film, which is located in one corner of the bonding surface of the target object, is first separated from the bonding surface of the target object, and then the adhesive film is wound up and delaminated while holding the separated part of the adhesive film and rotating it in a delamination direction at a constant rotational speed. It is described that this method allows the adhesive film to be delaminated from the target object at a constant delamination speed regardless of the adhesion strength between the bonding surface of the target object and the adhesive film, and thus allows the adhesive film to be easily delaminated from the target object even if the adhesion strength between the bonding surface of the target object and the adhesive film is high (see, e.g., Patent Document 1).
Similarly, another method for delaminating an adhesive film has been disclosed in which a part of an adhesive film (a polarizing plate), which is located in one corner of a bonding surface of a target object (an LCD panel), is separated from the bonding surface of the target object, the adhesive film is wound up by a predetermined number of turns onto a wind-up roller from the delaminated part of the adhesive film, and then the adhesive film is pulled and delaminated while moving the wind-up roller in a delamination direction. It is described that this method allows the delaminated adhesive film such as a polarizing plate to be easily collected (see, e.g., Patent Document 2).
However, in the above conventional delamination methods, the polarizing plate is pulled and delaminated from the LCD panel while winding up the polarizing plate. Thus, as shown in
Moreover, the configuration of winding up the LCD panel 51 can deform or damage the polarizing plate 50.
The present invention was developed in view of the above problems, and it is an object of the present invention to provide an apparatus and a method for delaminating an adhesive film, which are capable of effectively suppressing deformation or damage to the adhesive film such as a polarizing plate and a target object having the adhesive film such as an LCD panel.
In order to achieve the above object, an apparatus for delaminating an adhesive film according to the present invention includes: a delamination stage configured so that a target object having the adhesive film bonded to a surface of a substrate via an adhesive layer is placed thereon; and a wire that is placed to extend along an entire outer periphery of the adhesive film so that the wire is inserted into a gap formed between the substrate and the adhesive film in four corners of the adhesive film. The apparatus according to the present invention further includes: a wire wind-up portion configured to wind up the wire to move the wire; a drive portion configured to drive the wire wind-up portion; and a control portion configured to control the drive portion. The control portion controls the drive portion so that the wire wind-up portion winds up the wire in order to delaminate the adhesive film from the substrate by separating the adhesive film from the substrate while moving the wire between the adhesive film and the substrate.
With the above configuration, the adhesive film can be delaminated by the wire being wound up, without subjecting an adhesive-film delamination interface of the substrate to a stress in a thickness direction of the substrate. This can prevent deformation or damage to the target object due to the stress. Since the adhesive film is not wound up, the adhesive film can be delaminated without being deformed, and damage to the adhesive film can be prevented.
In the apparatus of the present invention, the control portion may control the drive portion so that a moving speed of the wire when winding up the wire is in a range of 0.05 mm/sec to 1.80 mm/sec, both inclusive.
With the above configuration, the moving speed of the wire can be adjusted to a desired low moving speed. Thus, the timing of destroying the adhesive layer can be controlled according to adhesion strength of the adhesive film, and delamination resistance can be reduced.
In the apparatus of the present invention, the wire may be a thin wire.
With the above configuration, the delamination resistance can be flexibly distributed in an arc shape regardless of the material and the composition state of the wire. Moreover, the same wire can be repeatedly used until it breaks.
In the apparatus of the present invention, the wire may have a diameter in a range of 0.1 mm to 0.5 mm, both inclusive.
With the above configuration, the adhesive film can be safely and reliably delaminated even if the gap between the substrate and the adhesive film is narrow.
The apparatus of the present invention has an excellent property in which the adhesive film can be delaminated without causing deformation or damage to the target object having the adhesive film bonded thereto. Thus, the apparatus of the present invention is preferably used in the case where the substrate is a glass substrate of an LCD panel and the adhesive film is a polarizing plate.
A method for delaminating an adhesive film according to the present invention is a method for delaminating an adhesive film bonded to a surface of a substrate via an adhesive layer. The method of the present invention includes the step of separating the adhesive film from the substrate in four corners of the adhesive film, and forming a gap between the substrate and the adhesive film in the four corners of the adhesive film. The method of the present invention further includes at least the steps of: placing a wire so that the wire extends along an entire outer periphery of the adhesive film, and inserting the wire into the gap in the four corners of the adhesive film; and winding up the wire to separate the adhesive film from the substrate while moving the wire between the adhesive film and the substrate, thereby delaminating the adhesive film from the substrate.
With the above configuration, the adhesive film can be delaminated by the wire being wound up, without subjecting an adhesive-film delamination interface of the substrate to a stress in a thickness direction of the substrate. This can prevent deformation or damage to the target object due to the stress. Since the adhesive film is not wound up, the adhesive film can be delaminated without being deformed, and damage to the adhesive film can be prevented.
In the method of the present invention, a moving speed of the wire when winding up the wire may be in a range of 0.05 mm/sec to 1.80 mm/sec, both inclusive.
With the above configuration, the moving speed of the wire can be adjusted to a desired low moving speed. Thus, the timing of destroying the adhesive layer can be controlled according to adhesion strength of the adhesive film, and delamination resistance can be reduced.
In the method of the present invention, the wire may be a thin wire.
With the above configuration, the delamination resistance can be flexibly distributed in an arc shape regardless of the material and the composition state of the wire. Moreover, the same wire can be repeatedly used until it breaks.
In the method of the present invention, the wire may have a diameter in a range of 0.1 mm to 0.5 mm, both inclusive.
With the above configuration, the adhesive film can be safely and reliably delaminated even if the gap between the substrate and the adhesive film is narrow.
The method of the present invention has an excellent property in which the adhesive film can be delaminated without causing deformation or damage to the target object having the adhesive film bonded thereto. Thus, the method of the present invention is preferably used in the case where the substrate is a glass substrate of an LCD panel and the adhesive film is a polarizing plate.
The present invention allows an adhesive film to be delaminated from a target object having the adhesive film bonded thereto, without causing deformation or damage to the target object.
An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Note that the present invention is not limited to the following embodiment.
As shown in
As shown in
As shown in
A motor is used as the drive portion 6 configured to drive the wire wind-up portion 5. As shown in
The control portion 7 is connected to the drive portion 6, and is configured to control the drive portion 6. As shown in
The wire 10 is a deformable wire. Although the material of the wire 10 is not particularly limited, the wire 10 may be comprised of, e.g., a thin wire such as a metal wire like a piano wire, a resin wire like Dyneema that is used for fishing lines etc. By using such a wire, the delamination resistance can be distributed in an arc shape. Moreover, the same wire can be repeatedly used until it breaks.
Although the diameter “L” of the wire 10 shown in
An example of a method for delaminating a polarizing plate bonded to an LCD panel by using the polarizing-plate delaminating apparatus 1 having the above configuration will be described below.
First, the LCD device will be described. As shown in
The LCD panel 35 includes a TFT substrate 31 (thickness: about 0.20 mm) as a first substrate, and a CF substrate 32 (thickness: about 0.10 mm) as a second substrate facing the TFT substrate 31. The LCD panel 35 further includes a liquid crystal layer 33 as a display medium layer provided between the TFT substrate 31 and the CF substrate 32, and a sealant 34 provided in a frame shape in order to bond the TFT substrate 31 to the CF substrate 32, and to enclose the liquid crystal layer 33 therebetween. The sealant 34 is formed so as to surround the liquid crystal layer 33, and the TFT substrate 31 is bonded to the CF substrate 32 via the sealant 34. Each of the TFT substrate 31 and the CF substrate 32 is comprised of a glass substrate.
As shown in
Each of the polarizing plates 36, 37 is provided with an adhesive layer 39, which is provided on the surface of one support body 38a and configured to bond the polarizing plate 36, 37 to the surface of the TFT substrate 31 or the CF substrate 32. That is, in the LCD panel 35 as a target object, the polarizing plates 36, 37 as adhesive films are bonded to the surface of the TFT substrate 31 and the surface of the CF substrate 32 via the adhesive layers 39, respectively.
The adhesive layer 39 is comprised of e.g., an acrylic adhesive polymerized with butylacrylate, and has viscoelasticity of 16,000 Pa at 75° C. The polarizing plate 36, 37 has a size of, e.g., 140 nm by 230 nm.
The method for delaminating the polarizing plate will be specifically described below.
First, as shown in
More specifically, the tip of a blade (not shown), a thin metal sheet, etc. is first brought into contact with the surface of the CF substrate 32 at a position located outside the peripheral end of the polarizing plate 36. Then, the tip of the blade is moved along the surface of the CF substrate 32 to insert the blade between the CF substrate 32 and the polarizing plate 36, thereby forming the gap “S” between the CF substrate 32 and the polarizing plate 36 in each of the four corners R.
Next, the LCD device 30 (i.e., the LCD panel 35 as a target object) having the gaps “S” formed therein is placed on the delamination stage 3. In the present embodiment, the LCD device 30 placed on the delamination stage 3 need not be fixed.
Then, the other end 10b of the wire 10 is latched on the latch portion 5c provided on the roller 5a of the wire wind-up portion 5, thereby fixing the wire 10 to the roller 5a.
Thereafter, as shown in
Subsequently, with the wire 10 being inserted in the gaps “S” in the four corners R of the polarizing plate 36, the one end 10a of the wire 10 is latched on the latch portion 4d provided in the sagging absorbing portion 4b of the wire fixing portion 4, thereby fixing the wire 10 to the sagging absorbing portion 4b.
Then, the sagging absorbing portion 4b is rotated in the direction of arrow “A” shown in
Thereafter, the power button 7a provided in the control portion 7 is depressed to turn on the motor as the drive portion 6.
Thus, winding-up of the wire 10 is started, and delamination of the polarizing plate 36 is started.
At this time, in the present embodiment, the polarizing plate 36 can be delaminated by the wire 10 being wound up, without subjecting the polarizing-plate delamination interface of the CF substrate 32 to a stress in the thickness direction of the CF substrate 32.
More specifically, if the winding-up of the wire 10 is started from the state of
At this time, as shown in
In the present embodiment, since each of a force “F3” with which the wire 10 moving in the direction of arrow “X” delaminates the polarizing plate 36 and a force “F4” with which the wire 10 moving in the direction of arrow “Y” delaminates the polarizing plate 36, as shown in
As described above, in the present embodiment, the LCD device 30 placed on the delamination stage 3 need not be fixed. This is because the force “F4” serves as a force with which the LCD device 30 is fixed when the polarizing plate 36 is delaminated by the wire 10.
The wind-up speed (the moving speed) of the wire 10, namely the speed at which the wire 10 is wound up (moved), is preferably in the range of 0.05 mm/sec to 1.80 mm/sec, both inclusive. If the wind-up speed is lower than 0.05 mm/sec, rotation and torque of the motor may be destabilized due to the low wind-up speed, and the time it takes to delaminate the polarizing plate 36 may be excessively increased. If the wind-up speed is higher than 1.80 mm/sec, the moving speed of the wire 10 becomes higher with respect to the timing the adhesive layer 39 between the polarizing plate 36 and the CF substrate 32 is destroyed. This tends to cause bending of the polarizing plate 36 etc., making it difficult to normally delaminate the polarizing plate 36. That is, using the wind-up speed (the moving speed) of the wire 10 in the range of 0.05 mm/sec to 1.80 mm/sec, both inclusive, allows the moving speed of the wire 10 to be adjusted to a desired low moving speed. Thus, the timing of destroying the adhesive layer 39 can be controlled according to the adhesion strength of the polarizing plate 36, and the delamination resistance can be reduced.
Then, as the wire 10 is further wound up from the state of
That is, in the present embodiment, the control portion 7 is configured to control the drive portion 6 so that the wire wind-up portion 5 winds up the wire 10 in order to delaminate the polarizing plate 36 from the CF substrate 32 by separating the polarizing plate 36 from the CF substrate 32 while moving the wire 10 between the polarizing plate 36 and the CF substrate 32 of the LCD panel 35.
At this time, since the polarizing plate 36 is not wound up as in the above related art, the polarizing plate 36 can be delaminated without being deformed as shown in
Then, the stop button 7c provided in the control portion 7 is depressed to turn off the motor as the drive portion 6, whereby winding-up of the wire 10 is terminated.
Thereafter, as in the delamination of the polarizing plate 36 described above, the polarizing plate 37 is delaminated from the LCD panel 35 (i.e., the TFT substrate 31) by using the wire 10.
The polarizing plates 36, 37 can be delaminated from the LCD panel 35 in this manner.
The following advantages can be obtained by the present embodiment described above.
In the present embodiment, the wire 10 is placed to extend along the entire outer periphery of the polarizing plate 36, so that the wire 10 is inserted into the gaps “S” formed between the CF substrate 32 and the polarizing plate 36 in the four corners R of the polarizing plate 36. Moreover, the polarizing plate 36 is delaminated from the CF substrate 32 by separating the polarizing plate 36 from the CF substrate 32 while moving the wire 10 between the polarizing plate 36 and the CF substrate 32 by winding up the wire 10. This configuration allows the polarizing plate 36 to be delaminated by the wire 10 being wound up, without subjecting the polarizing-plate delamination interface of the CF substrate 32 to a stress in the thickness direction (that is, the thickness direction “T” of the LCD panel 35) of the CF substrate 32. This can prevent deformation or damage to the LCD panel 35 due to the stress. Moreover, since the polarizing plate 36 is not wound up, the polarizing plate 36 can be delaminated without being deformed, and damage to the polarizing plate 36 can be prevented.
In the present embodiment, the moving speed of the wire 10 when winding up the wire 10 is in the range of 0.05 mm/sec to 1.80 mm/sec, both inclusive. This configuration allows the moving speed of the wire 10 to be adjusted to a desired low moving speed. Thus, the timing of destroying the adhesive layer 39 can be controlled according to the adhesion strength of the polarizing plate 36, and the delamination resistance can be reduced.
In the present embodiment, a thin wire is used as the wire 10. This configuration allows the delamination resistance to be flexibly distributed in an arc shape regardless of the material and the composition state of the wire, and also allows the same wire to be repeatedly used until it breaks.
In the present embodiment, the diameter “L” of the wire 10 is in the range of 0.1 mm to 0.5 mm, both inclusive. This configuration allows the polarizing plate 36 to be safely and reliably delaminated without causing disadvantages such as breakage of the wire 10 or bending of the polarizing plate 36, even if the gap between the polarizing plate 36 and the CF substrate 32 is narrow.
The above embodiment may be modified as follows.
The above embodiment is described above with respect to an example in which the LCD panel 35 having the polarizing plates 36, 37 respectively bonded to the surfaces of the TFT substrate 31 and the CF substrate 32 via the adhesive layers 39 is used as a target object. However, the target object to which the present invention is applied is not limited to this. For example, the present embodiment may be used as a separation method in the case where an element that is hard and is easily broken, an element that is easily deformed, etc. has been fixed to a target object by an adhesive or a bonding material. The target object need not necessarily be a planar object. Even if the target object is a curved object, a spherical object, etc., an element can be separated or delaminated from the target object without destroying the target object.
The present invention will be described based on an example and a comparative example. The present invention is not limited to this example, and various modifications and variations can be made without departing from the scope and sprit of the present invention.
First, thirty LCD devices, each including an LCD panel and polarizing plates bonded thereto, were prepared. Each of the LCD panels used in this example included a TFT substrate comprised of a glass substrate having a length of 73 mm, a width of 41 mm, and a thickness of 0.2 mm, a CF substrate comprised of a glass substrate having a length of 70 mm, a width of 41 mm, and a thickness of 0.1 mm, a liquid crystal layer provided between the TFT substrate and the CF substrate and having a thickness of 4 vim, and a sealant provided in a frame shape in order to enclose the liquid crystal layer. Each of the polarizing plates used in the first example had an adhesive layer provided on its surface, and had a length of 69 mm, a width of 41 mm, and a thickness of 0.2 mm.
Next, in each of the LCD devices, the polarizing plate was delaminated by using the polarizing-plate delaminating apparatus shown in
Then, each of the LCD panels after delamination of the polarizing plates was visually examined for damage. It was determined that the LCD panel had been damaged, if there was any fracture (crack) in the LCD panel after delamination of the polarizing plates.
As a result, in this example, no damage was observed in any of the LCD panels after delamination of the polarizing plates, and the polarizing plates were able to be delaminated without damaging the LCD panels.
First, ten LCD devices, each including an LCD panel and polarizing plates bonded thereto, were prepared in a manner similar to that of the first example.
Next, in each of the LCD devices, the polarizing plate was delaminated by separating the polarizing plate in one corner from the bonding surface of the LCD panel, and winding up the polarizing plate while holding the separated part of the polarizing plate and rotating it in the delamination direction at a rotational speed of 0.5 mm/sec.
Then, as in the first example, each of the LCD panels after delamination of the polarizing plates was visually examined for damage.
As a result, in this comparative example, damage was observed in all of the ten LCD panels after delamination of the polarizing plates.
As described above, the present invention relates to apparatuses and methods for delaminating an adhesive film, and is especially suitable for apparatuses and methods for delaminating a polarizing plate bonded to an LCD panel.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-212011 | Sep 2009 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2010/003138 | 5/7/2010 | WO | 00 | 2/9/2012 |
