JP2002258757A - Display element, method for protecting surface of the same, method for producing the same, method for producing liquid crystal device and electronic appliance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure or method capable of avoiding the abnormal lighting and damage of a display element by preventing the generation of static electricity when a protective film is peeled off. SOLUTION: A liquid crystal display panel has a polarizing plate 4 stuck on the outer surface of a substrate 1 or 2 and a protective film 5 having self- adhesion is stuck on the surface of the polarizing plate 4 by its self-adhesive power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, a method for protecting the surface thereof, and a method for manufacturing the same, and more particularly, to a technique for protecting an outer surface of the display device.

[0002]

2. Description of the Related Art As one type of display element, there is a liquid crystal display panel. This liquid crystal display panel is cured by bonding a pair of substrates made of glass, plastic, or the like through a sealing material made of a thermosetting resin. Thereafter, a basic cell structure formed by injecting liquid crystal into the inside of the sealing material is provided.

An electrode pattern of a predetermined shape is formed on each of the inner surfaces of the pair of substrates, and an alignment film is further formed thereon. The alignment film maintains the liquid crystal in a predetermined initial alignment state. The liquid crystal molecules in the initial alignment state are configured to be aligned in a direction corresponding to the direction of the electric field by applying a predetermined voltage between the electrode patterns. It can be controlled.

In a conventional liquid crystal display device, a polarizing plate 10 is attached to the outer surfaces of the pair of substrates using a polarizing tape shown in FIG. As shown in FIG. 5, an adhesive layer 10a is formed on the back surface of the polarizing plate 10, and this is covered with a release sheet 11. In addition, a protective film 12 is attached to the surface of the polarizing plate 10 in advance. Protective film 1
Reference numeral 2 denotes a polyester-based material (for example, polyethylene terephthalate: PET), and an adhesive layer 12
a is formed, and is adhered to the polarizing plate 10 by the adhesive layer 12a. This protective film 12 is for preventing dust from adhering to or scratching the surface (outer surface) of the polarizing plate.

[0005]

However, when the protective film 12 adhered to the surface (outer surface) of the polarizing plate is peeled off, the adhesive layer 12a formed on the inner surface of the protective film 12 is removed from the outer surface of the polarizing plate. The liquid crystal display panel is charged by the generation of static electricity when it is separated from the device, and the electric field causes the liquid crystal to be turned on due to abnormal lighting, which makes subsequent visual inspection and lighting inspection difficult. Alternatively, there is a problem that an internal structure such as an electrode pattern, a wiring pattern, or an active element (for example, a TFT (thin film transistor) or a TFD (thin film diode)) formed in the liquid crystal display panel is destroyed by a discharge caused by static electricity or the like. is there.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a structure or a structure capable of avoiding abnormality or damage of a display element by preventing generation of static electricity generated when a protective film is peeled off. It is to provide a method.

[0007]

In order to solve the above-mentioned problems, the display element of the present invention is characterized in that the self-adhesive protective film is directly (ie, not through an adhesive layer or an adhesive layer) due to its self-adhesive force. It is characterized by being attached on the outer surface. According to the present invention, since the protective film is directly adhered to the outer surface by its self-adhesive force, the work of peeling from the outer surface of the protective film becomes easy, and static electricity is less likely to be generated at the time of film peeling. In addition, it is possible to prevent troubles caused by static electricity, such as abnormal lighting of a display element and destruction of an internal structure.

In the present invention, the protective film preferably contains polyethylene. Since polyethylene has self-adhesion, self-adhesion can be generated by using a protective film containing polyethylene.

In the present invention, the protective film is preferably made of polyethylene. Polyethylene has self-adhesion and is easily and inexpensively available. As the protection film made of polyethylene, for example, low density polyethylene (LDPE) can be used. The thickness of the protective film made of polyethylene is 30 to 100 μm.
Is preferably within the range. Beyond this range,
Since the rigidity of the film and the amount of static electricity generated when the film is peeled off have a positive correlation, it is difficult to sufficiently suppress the generation of static electricity when the film is peeled off. It cannot be obtained, and dents are likely to be formed on the surface of the polarizing plate. From this point of view, it is desirable that the thickness be in the range of 50 to 70 μm.

The self-adhesive strength of the protective film is from 10 to 30 gf / 25 mm (4 to
12 kN / m: gf ≒ 10 m / s ² )
Is preferably within the range. If it exceeds this range, static electricity is likely to be generated when the film is peeled off, and if it is below this range, the adhesion of the film is reduced and handling becomes difficult.

In the present invention, it is preferable to have a structure in which an electro-optical function layer is sandwiched between a pair of substrates provided with electrodes. In a case where the electro-optical function layer has a structure in which the electro-optical function layer is sandwiched between a pair of substrates, and the electrodes formed on these substrates are configured to apply a predetermined electric field to the electro-optical function layer, static electricity is generated. The above-described invention is particularly effective in that abnormal lighting and element destruction can be prevented by preventing the above.

In the present invention, it is preferable that the protective film is directly or indirectly attached to the outer surfaces of both the pair of substrates. Since the protective films are attached to both outer surfaces of the pair of substrates, it is possible to prevent dust from being attached and scratches from being generated during the manufacturing process or during transportation.

In the present invention, there is a case where the electro-optical function layer is a liquid crystal layer, that is, a case where the display element is a liquid crystal display panel.

Further, the present invention may have a structure in which an electro-optical function layer is sandwiched between a pair of electrodes, and the pair of electrodes is provided on a substrate.

In this case, the electro-optical function layer may be an electroluminescence layer. In this case as well, abnormal lighting and the like can be prevented as in the case of the display element having the liquid crystal layer.

According to another aspect of the invention, there is provided an electronic apparatus including the above-described display element as a display unit. Examples of the electronic device include a mobile phone, a portable information terminal, a television, a display monitor, and the like.

The surface protection method for a display element of the present invention is a surface protection method for protecting the outer surface of the display element,
The protective film having a self-adhesive property is characterized in that the self-adhesive protective film is directly attached to the outer surface.

In the present invention, the display element has a structure in which an electro-optical function layer is sandwiched between a pair of substrates provided with electrodes, and when the electro-optical function layer is a liquid crystal layer, It is preferable to prepare a polarizing plate to which the protective film has been previously attached, and to adhere the back surface of the polarizing plate to the substrate. According to this means, it is possible to protect the outer surface of the polarizing plate before attaching to the outer surface of the substrate.

Further, the method for manufacturing a display element according to the present invention comprises:
A protective film having self-adhesiveness is attached to at least the outer surface of the display element on which the basic structure has been formed, and thereafter, a post-process of performing a predetermined inspection or a predetermined process on the display element is performed. I do.

In the present invention, after the protective film is adhered to the outer surface of the display element, the protective film is once peeled off and the display element is inspected.
After that, it is preferable that the protective film is again attached to the outer surface. In this case, when the protective film is once peeled, instead of completely peeling the protective film from the outer surface of the display element, the protective film is part of the outer surface within a range that does not hinder the above inspection, for example, It is preferable that the above-described inspection is performed in such a state that the protective film remains attached to the outer edge portion of the outer surface in order to facilitate the subsequent attachment of the protective film.

Further, in the present invention, the outer surface of the display element is preferably an optically functional surface (for example, a transmission type liquid crystal display device) which can provide an effect of maintaining the display quality by the protective film. Is preferable, and particularly, the display surface (the surface from which a display image is emitted) is desirable.

Further, in the present invention, it is preferable that the protective film is transparent in that the display quality and appearance can be confirmed while being attached to the display element.

Further, a method of manufacturing a liquid crystal device according to the present invention is a method of manufacturing a liquid crystal device having a basic structure in which a liquid crystal layer is sandwiched between a pair of substrates provided with electrodes. The method is characterized by comprising a step of attaching a protective film having adhesiveness by its self-adhesive force, and a step of performing an appearance inspection or a lighting inspection on the display element.

The present invention provides a protective tape comprising a base material, mounting means for mounting the back surface of the base material to another member, and a protective film adhered to the surface of the base material by self-adhesive force. Can also be captured. Here, a specific example of the substrate includes a polarizing plate. Further, the attachment means may include an adhesive layer or an adhesive layer formed on the back surface of the polarizing plate, and may further include a release sheet covering the adhesive layer or the adhesive layer.

[0025]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a display device according to the present invention.

FIG. 1 is a schematic perspective view showing a structure of a liquid crystal display panel which is a display element of the present embodiment, and FIG. 2 is a longitudinal sectional view of the liquid crystal display panel. This liquid crystal display panel has transparent substrates 1 and 2 made of glass, plastic, or the like.
Are bonded together with the sealing material 3 interposed therebetween. The substrate 1 has a substrate overhang portion 1a that extends outside the outer shape of the substrate 2.
Are formed. Electrode patterns (not shown) are formed on the inner surfaces of the substrates 1 and 2 by transparent conductors such as ITO (indium tin oxide), respectively, and the wiring patterns 1b electrically connected to these electrode patterns are formed on the substrate overhang. It is formed so as to be drawn out onto the portion 1a.

The wiring pattern 1b has an input terminal array configured to be conductively connected to a flexible substrate (not shown), a TAB substrate, or the like. Note that, unlike the illustrated example, in the case of a COG (Chip On Glass) type liquid crystal display panel, an IC chip constituting a liquid crystal drive circuit is directly mounted on the wiring pattern 1b.

Polarizing plates 4 and 6 are adhered on the outer surfaces of the substrates 1 and 2, respectively. Further, on the surfaces of these polarizing plates 4 and 6, polyethylene (for example, low density polyethylene (LDP)) is used.
E) The protective films 5, 7 consisting of) are attached.
The protective films 5 and 7 have self-adhesiveness, and adhere to the polarizing plates 4 and 6 only by their self-adhesive force without using an adhesive or an adhesive. In the case of the present embodiment, the protective films 5 and 7 are transparent films.

The polarizing plates 4 and 6 are adhered on the outer surfaces of the substrates 1 and 2 using the polarizing tape shown in FIG. In this polarizing tape, adhesive layers 4a and 6a are formed on the back surfaces of the polarizing plates 4 and 6, similarly to the polarizing plate 10, and the adhesive layers 4a and 6a are in a state covered by the release sheet 11. I have. The protective films 5 and 7 are previously attached to the surfaces of the polarizing plates 4 and 6 by their self-adhesive force.

The thickness of the protective films 5 and 7 is 60 μm in the case of the present embodiment, but it can be used without any particular problem within the range of 30 to 100 μm.
It is desirable to be within the range of 70 μm. If the protective film is too thick, its rigidity is increased, so that static electricity is easily generated at the time of peeling. If the protective film is too thin, the protective property may be reduced and dents may be formed on the surfaces of the polarizing plates 4 and 6.

The self-adhesive strength of the protective films 5 and 7 is 10 to 30 gf / 25 mm (4
１２12 kN / m: gf ≒ 10 m / s ² . ) Is preferable. Here, as shown in FIG.
A tape X formed in a tape shape (band shape) having a thickness of 1 mm is adhered to the substrate surface Y, and a stress required for peeling when the tape X is peeled in a direction perpendicular to the substrate surface Y is measured. I asked. If the self-adhesive strength is higher than this range, static electricity is likely to be generated at the time of film peeling, and if the self-adhesive strength is below this range, the adhesion of the protective film will be insufficient and it will be easy to peel off naturally, so the handling during the manufacturing process and transporting It becomes difficult.

In this embodiment, after forming the electrode patterns on the inner surfaces of the substrates 1 and 2 respectively, the sealing material 3 is formed.
Then, the substrate 1 and the substrate 2 are bonded together, and the sealing material 3 is cured to form a cell structure. Thereafter, liquid crystal is injected and sealed inside the sealing material 3. Thereafter, the peeling sheet 11 of the polarizing tape is peeled off, and the polarizing plates 4 and 6 to which the protective film 5.7 is adhered are adhered on the outer surfaces of the substrates 1 and 2. In this manner, the state in which the protective films 5 and 7 are attached to the outer surface of the basic structure of the liquid crystal display panel can be obtained.

Next, the polarizing plate 4 attached as described above is used.
In order to bleed air from the surface to which the substrate 6 is adhered, the liquid crystal display panel is heated in a pressurized state to remove air between the outer surfaces of the substrates 1 and 2 and the polarizing plates 4 and 6. At this time, even if the polarizing plates 4 and 6 are charged by static electricity generated when the release sheet 11 is peeled as described above, the static electricity is removed by the heat treatment in the above-mentioned pressurized state.

Further, an appearance inspection or a lighting inspection is performed on the liquid crystal display panel on which the above processing is completed. If the protective films 5 and 7 are transparent films as described above, these inspections can be performed with the protective films 5 and 7 attached. However, in order to improve the inspection efficiency and the inspection accuracy, it is preferable that the protective films 5 and 7 are once peeled off and the inspection is performed in a state where the polarizing plates 4 and 6 are exposed.

FIG. 3 shows how the protection films 5 and 7 are peeled off for inspection. As shown in FIG. 3, the protective film 5 is peeled off from the polarizing plate 4 except for the peripheral portion (one corner in the illustrated example) of the liquid crystal display panel. In this state, the portion where the protective film 5 is adhered to the polarizing plate 4 is outside the driving region of the liquid crystal display panel (the region where the display state can be controlled by the electric field applied to the electrode pattern, ie, the display region). ,
Even if this part is blocked, it is a part that does not hinder the inspection. Although not shown, the protective film 7 adhered to the polarizing plate 6 is also peeled off except for a portion that does not hinder the inspection, similarly to the protective film 5 described above.

After performing the inspection in the above state, the protective films 5 and 7 are adhered to the surfaces of the polarizing plates 4 and 6 again.
Then, a module process such as attaching a backlight, attaching a reflective film (in the case of a reflective liquid crystal display panel), attaching to a support frame, and connecting a flexible substrate or a TAB substrate is performed.

The procedure of the above-mentioned inspection step and module step can be changed as appropriate. For example, in the case of a COG type liquid crystal display panel, an appearance inspection is performed after performing a module process including mounting of an IC chip.

The liquid crystal device formed as described above has
It can be shipped with the protective films 5 and 7 attached. Of course, another protective film other than the above protective film may be attached to the completed liquid crystal device as a display element, but the other protective film also has the same self-adhesiveness as the protective films 5 and 6. Preferably, it is This is because the outer surface of the display element, particularly the display surface, can be protected by covering the display element with a protective film until the display element is incorporated into a product (various electronic devices), and the protective film is peeled before and after the display element is incorporated. This is to prevent static electricity from being generated sometimes.

The above is the description of the case where only the polarizing plate is attached to the substrate, but the same applies to the case where the retardation film between the polarizing plate and the substrate is attached to the polarizing plate in advance. Also,
Even when a reflective plate is previously adhered to the polarizing plate, the same effect can be obtained by using the same material for the protective film of the reflective plate.

It should be noted that the display element, surface protection method and manufacturing method of the present invention are not limited to the illustrated examples described above, and various changes can be made without departing from the scope of the present invention. It is.

The display element is not limited to the above-described liquid crystal display panel, but may be a liquid crystal panel for forming an image of a projector, or may have another electro-optical function layer such as an electroluminescence panel. It does not matter.

FIG. 7 schematically shows a configuration example of an electroluminescence panel to which the present invention is applied. In this configuration example, an organic EL panel 20 is configured. In the organic EL panel 20, an anode 22 made of ITO or the like is formed on an inner surface of a substrate 21 made of glass or the like, and an organic EL film 23 is formed on the anode 22. This organic EL film 23
Has a structure in which three layers of a hole transport layer, a light emitting layer, and an electron transport layer are stacked from above the anode 22. Organic EL
A cathode 24 is formed on the film 23, and these are
1 is covered by a sealed container 26 attached via an adhesive layer 25. Nitrogen gas or the like is sealed inside the sealed container 26. The anode 22 and the cathode 23 are conductively connected to a flexible wiring board 29 and the like (the connection part of the anode 22 is not shown). In this organic EL panel 20, the organic EL film 2
Light emitted from the light-emitting layer 3 is emitted to the outside through the substrate 21. Then, in the case of this configuration example, the same protective film 28 as described above is attached on the outer surface of the substrate 21 by self-adhesive force.

In addition to the above-mentioned polyethylene film, any protective film may be used as long as it has self-adhesiveness and has a protective function. For example, a material containing polyethylene and containing other resin may be used.

[0044]

As described above, according to the present invention,
Since the work of peeling from the outer surface of the protective film is facilitated and static electricity is hardly generated at the time of film peeling, it is possible to prevent troubles caused by the static electricity, such as abnormal lighting of the display element and destruction of the internal structure. be able to. In particular, abnormal lighting of the display element significantly reduces the workability of the lighting inspection. According to the present invention, it is possible to prevent a defect such that it is not possible to inspect a defect of the portion (inside / outside of a cell) when the portion is lit.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a schematic structure of a liquid crystal display panel which is an embodiment of a display element according to the present invention.

FIG. 2 is a schematic longitudinal sectional view of the liquid crystal display panel of the embodiment.

FIG. 3 is a schematic perspective view showing a state in which a liquid crystal display panel is inspected in the embodiment.

FIG. 4 is a schematic sectional view showing a sectional structure of a polarizing tape used in the embodiment.

FIG. 5 is a schematic sectional view showing a sectional structure of a conventional polarizing tape.

FIG. 6 is an explanatory view showing how to measure the self-adhesive strength of the protective film.

FIG. 7 is a schematic sectional view showing a configuration example of an organic EL panel to which the present invention is applied.

[Explanation of symbols]

 1, 2 substrate 3 sealing material 4, 6 polarizing plate 5, 7, 28 protective film 20 organic EL panel 21 substrate 22 anode 23 organic EL film 24 cathode

Claims (26)

[Claims] 1. A display device, wherein a protective film having self-adhesiveness is directly adhered to an outer surface by its self-adhesive force. 2. The display device according to claim 1, wherein the protective film contains polyethylene. 3. The display device according to claim 1, wherein the protective film is made of polyethylene. 4. The display element according to claim 1, wherein the display element has a structure in which an electro-optical function layer is sandwiched between a pair of substrates provided with electrodes. 5. The display device according to claim 4, wherein the protective film is directly or indirectly attached to both outer surfaces of the pair of substrates. 6. The display device according to claim 4, wherein the electro-optical function layer is a liquid crystal layer. 7. An electro-optical function layer sandwiched between a pair of electrodes,
The display device according to any one of claims 1 to 3, wherein the display device has a structure in which the pair of electrodes is provided on a substrate. 8. The display device according to claim 7, wherein the electro-optical function layer is an electroluminescence layer. 9. An electronic apparatus comprising the display element according to claim 1 as a display unit. 10. A surface protection method for protecting an outer surface of a display element, wherein a self-adhesive protective film is directly adhered to the outer surface by its self-adhesive force. Characteristic method for protecting the surface of a display element. 11. The method according to claim 10, wherein the protection film includes polyethylene. 12. The method according to claim 10, wherein the protective film is made of polyethylene. 13. The display element according to claim 10, wherein the display element has a structure in which an electro-optical function layer is sandwiched between a pair of substrates provided with electrodes. Surface protection method for a display element. 14. The method according to claim 13, wherein the protection film is directly or indirectly attached to both outer surfaces of the pair of substrates. 15. The method according to claim 13, wherein the electro-optical function layer is a liquid crystal layer. 16. The surface protection of a display element according to claim 15, wherein a polarizing plate having the protective film adhered thereto in advance is prepared, and the back surface of the polarizing plate is attached to the substrate. Method. 17. The structure according to claim 10, wherein the electro-optical function layer is sandwiched between a pair of electrodes, and the pair of electrodes is provided on a substrate. Surface protection method for a display element. 18. The method according to claim 17, wherein the electro-optical function layer is an electroluminescence layer. 19. A state in which a protective film having self-adhesiveness is adhered to the outer surface of at least the display element on which the basic structure has been formed by its self-adhesive force. A method for manufacturing a display element, which comprises performing a post-process. 20. The method according to claim 19, wherein the protective film contains polyethylene. 21. The method according to claim 19, wherein the protective film is made of polyethylene. 22. The display device according to claim 19, wherein the display element has the basic structure in which an electro-optical function layer is sandwiched between a pair of substrates provided with electrodes.
The method for manufacturing a display element according to any one of the above items. 23. The method according to claim 22, wherein the protective film is directly or indirectly attached to the outer surfaces of both the pair of substrates. 24. The method according to claim 22, wherein the electro-optical function layer is a liquid crystal layer. 25. The method for manufacturing a display element according to claim 24, wherein a polarizing plate having the protective film adhered thereto in advance is prepared, and the back surface of the polarizing plate is attached to the substrate. . 26. A method for manufacturing a liquid crystal device having a basic structure in which a liquid crystal layer is sandwiched between a pair of substrates provided with electrodes, wherein a protective film having self-adhesion is formed on an outer surface of the basic structure by self-adhesion. A method for manufacturing a liquid crystal device, comprising: a step of attaching by a force; and a step of performing an appearance inspection or a lighting inspection on the display element.