Adhesive layer-equipped transparent plate and display device

An adhesive layer-equipped transparent plate includes a transparent plate having a first surface and a second surface; a first adhesive layer provided on the first surface; and a second adhesive layer provided on the second surface; wherein the transparent plate includes at least one of an exposed portion in a periphery of the first surface, where the first surface is exposed from the first adhesive layer, and an exposed portions in a periphery of the second surface, where the second surface is exposed from the second adhesive layer.

TECHNICAL FIELD

The present invention relates to an adhesive layer-equipped transparent plate and a display device.

BACKGROUND ART

In recent years, as one of the application modes of a display device, the use of a display device in such a manner that it is bonded to a store window or a glass wall of an office so that the display surface faces outside, has been studied. By this mode, the display device can be utilized as a billboard, an advertising display, etc., since a passersby can recognize the display through the glass from the outside of the store or the office. For example, Patent Document 1 specified below discloses an arrangement where a display device main body, such as a liquid crystal panel, is bonded to a window glass via an adhesive layer-equipped transparent plate having an adhesive layer bonded to each of both surfaces thereof.

PRIOR ART DOCUMENTS

Patent Documents

DISCLOSURE OF INVENTION

Technical Problem

In a case where the bonding operation of a display device using the adhesive layer-equipped transparent plate disclosed in Patent Document 1 is performed, there has been, however, caused a problem that, for example, when a worker uses his or her hands to hold the adhesive layer-equipped transparent plate, the adhesive agent sticks to his or her hands to reduce the workability of the bonding operation. Or, there has been, caused a problem that even when a worker uses a jig, such as a holder, to hold the adhesive layer-equipped transparent plate at the time of performing the bonding operation, the adhesive agent sticks to the holder to reduce the workability of the bonding operation.

After a display device is utilized as a billboard, an advertising display, etc. for a store, the display device needs to be peeled from the window glass to restore the interior in the store in some cases. In such cases, there has been a problem that it is difficult for a worker to peel the adhesive layer-equipped transparent plate from the window glass.

According to one embodiment of the present invention, an adhesive layer-equipped transparent plate which makes it easy to perform a bonding operation for bonding a display device to a transparent support, such as a glass plate, or a peeling operation for peeling the display device from the transparent support. Further, according to another embodiment of the present invention, a display device which includes an adhesive layer-equipped transparent plate and which is excellent in the display quality, is provided.

Solution to Problem

The adhesive layer-equipped transparent plate according to one embodiment of the present invention includes a transparent plate having a first surface and a second surface; a first adhesive layer provided on the first surface; and a second adhesive layer provided on the second surface; wherein the transparent plate includes at least one of an exposed portion in a periphery of the first surface, where the first surface is exposed from the first adhesive layer, and an exposed portion in a periphery of the second surface, where the second surface is exposed from the second adhesive layer.

In the adhesive layer-equipped transparent plate according to one embodiment of the present invention, the transparent plate may be formed in a rectangular planar shape as observed from a normal direction of the first surface, and the exposed portion may be provided in a region along each of at least two sides of the four sides of the rectangular shape so as to be present at a portion of each of the at least two sides.

In the adhesive layer-equipped transparent plate according to one embodiment of the present invention, the exposed portion may be provided in a region along each of two opposing sides of the rectangular shape so as to be present at a portion of each of the two opposing sides.

In the adhesive layer-equipped transparent plate according to one embodiment of the present invention, the transparent plate may be formed in an oblong planar shape as observed from a normal direction of the first surface, and the exposed portion may be provided in a region along each of two opposing long sides of the oblong shape so as to be present at a portion of each of the two opposing long sides.

In the adhesive layer-equipped transparent plate according to one embodiment of the present invention, the exposed portion may be provided in a region along each of the four sides of the rectangular shape so as to be present at a portion of each of the four sides.

In the adhesive layer-equipped transparent plate according to one embodiment of the present invention, the transparent plate may be formed in a rectangular planar shape as observed from a normal direction of the first surface, and the exposed portion may be provided at a corner of the rectangular shape.

In the adhesive layer-equipped transparent plate according to one embodiment of the present invention, the first surface may include a first flat surface in a central area on the transparent plate, and a first inclined surface provided in the periphery of the transparent plate so as to be inclined to the first flat surface and have contact with an end surface perpendicular to the first flat surface, the second surface may include a second flat surface in a central area on the transparent plate, and a second inclined surface provided in the periphery of the transparent plate so as to be inclined to the second flat surface and have contact with an end surface perpendicular to the second flat surface, and the exposed portion may be provided on each of the first inclined surface and the second inclined surface.

In the adhesive layer-equipped transparent plate according to one embodiment of the present invention, the first surface or the second surface may have a light-shielding portion provided on the periphery thereof.

The display device according to one embodiment of the present invention includes an adhesive layer-equipped transparent plate according to one of the above-identified embodiments of the present invention, a transparent support bonded to the first surface of the adhesive layer-equipped transparent plate; and a display device main body bonded to the second surface of the adhesive layer-equipped transparent plate.

In the display device according to one embodiment of the present invention, the exposed portion may be provided on at least the first surface.

Advantageous Effects of Invention

According to one embodiment of the present invention, an adhesive layer-equipped transparent plate which makes it easy to perform a bonding operation for bonding a display device to a transparent support, such as a glass plate, or a peeling operation for peeling the display device from the transparent support. According to one embodiment of the present invention, a display device which includes an adhesive layer-equipped transparent plate and is excellent in the display quality, is provided.

DESCRIPTION OF EMBODIMENTS

First Embodiment

In the following drawings, in order to make various components easily understandable, the respective components may be shown as differentiated in their sizes.

In this specification, “transparent” means that after a plate and a display surface of a display device main body are bonded via an adhesive layer without a void space, the entire or a part of a display image on the display device main body is visible through the plate substantially without optical distortion. Accordingly, a plate can be regarded as “transparent” so long as a display image on a display device main body is visible substantially without optical distortion through the plate even if part of light which enters the plate from the display device main body is adsorbed or reflected by the plate, or even if the plate has a low visible light transmittance, e.g., by a change in the optical phase.

FIG. 1is a plan view illustrating the adhesive layer-equipped transparent plate according to the first embodiment.FIG. 2is a cross-sectional view along the line A-A′ inFIG. 1.FIG. 3is a plan view illustrating the adhesive layer-equipped transparent plate as observed from a first surface side.FIG. 3illustrates a state where a first protective film and a second protective film have been peeled from the adhesive layer-equipped transparent plate shown inFIGS. 1 and 2.

As shown inFIGS. 1 and 2, the adhesive layer-equipped transparent plate1according to the first embodiment includes a transparent plate2, a light-shielding portion3, a first adhesive layer4, a second adhesive layer5, the first protective film6and the second protective film7. The light-shielding portion3is provided on the periphery of a second surface2bof the transparent plate2. The first adhesive layer4is provided on a first surface2aof the transparent plate2. The second adhesive layer5is provided on the second surface2bof the transparent plate2. The second surface2bhas a smaller area than the first adhesive layer4.

The transparent plate2is a member in the form of a plate, which is a core material of the adhesive layer-equipped transparent plate1and which, when the after-mentioned display device main body is bonded to a transparent support, is to be interposed between the display device and the transparent support. The transparent plate2may, for example, be a glass plate or a resin plate. The transparent plate2is most preferably a glass plate in view of high transparency to injected light and reflected light from the display device main body, and in addition, in view of light resistance, low birefringence, high plane accuracy, surface abrasion resistance and high mechanical strength. The transparent plate2is preferably a glass plate also in view of high transmittance to light which cures a photocurable resin composition constituting the first adhesive layer4and the second adhesive layer5.

As an example of the glass plate, a glass material, such as soda lime glass, may be mentioned. Further, the glass plate is more preferably a high transmission glass (commonly called low-iron glass) having a lower iron content and less bluish tone. In order to increase the safety, tempered glass may be used as the surface material. Especially when a thin sheet glass is to be used, it is preferred to employ a glass plate subjected to chemical tempering. When the transparent plate2is bonded to the transparent support via the first adhesive layer4, the entire or a part of the transparent plate2may be curved, as described later. To prevent breakage of the transparent plate2on that occasion, a chemically tempered glass plate is preferably employed. As examples of the resin plate, a highly transparent resin material, such as polycarbonate or polymethyl methacrylate, may be mentioned.

The transparent plate2may be subjected to surface treatment to improve the interfacial adhesion to the first adhesive layer4and the second adhesive layer5. The surface treatment method may, for example, be a method of treating the surface of the transparent plate2with a silane coupling agent or a method of forming a silicon oxide thin film by oxidizing flame by a flame burner.

The shape of the transparent plate2may be determined in accordance with the planar shape of the display device main body which is to be bonded, and is rectangular or oblong as an example as shown inFIG. 1. The thickness of the transparent plate2is preferably from about 0.1 to about 30 mm, more preferably from about 0.1 to about 20 mm, further preferably from about 0.2 to about 2.0 mm in the case of a glass plate, in view of mechanical strength, transparency, etc. In order that an observer does not strongly feel that display looks far at the back (i.e., a sense of depth), the thickness of the transparent plate2is more preferably from about 0.2 to about 0.7 mm. In the case of a resin plate, the thickness of the transparent plate2is preferably from about 0.1 to about 1.0 mm. In order that the observer does not strongly feel a sense of depth of the display, the thickness of the transparent plate2is more preferably from about 0.1 to about 0.3 mm.

The light-shielding portion3has a function to shield attachments, such as a flexible printed wiring board connected to the display device main body, so that a region other than the image display region (a region outside the image display region) of the display device main body is not seen in a case where the adhesive layer-equipped transparent plate according to this embodiment is used for bonding between the display device main body and the transparent plate. In the case of this embodiment, the light-shielding portion3is bonded to the second surface2bas a side to which the display device main body is to be bonded, between the two surfaces2aand2bof the transparent plate2. The light-shielding portion3is formed, as shown inFIG. 1, in a frame form on the periphery along the four sides of the rectangular transparent plate2as observed from a normal direction of the first surface2aof the transparent plate2. The light-shielding portion3has an opening region3hformed in an inner side thereof to substantially conform to the image display region of the display device main body when the display device main body is bonded. Although, in this embodiment, external light may enter via exposed portions2cwhere the first surface and/or the second surface of the transparent plate2is exposed, it is possible to prevent the external light from being visible to an observer because the light-shielding portion3is formed to fully cover the exposed portions2cas shown inFIG. 1.

In a case where the transparent plate2is a glass plate, it is preferred in view of high shielding properties to form the light-shielding portion3by a printing method, such as ceramic printing with a black pigment. In a case where the transparent plate2is a chemically tempered glass plate, the heating temperature of the transparent plate2at the time of printing may be lowered by using an organic material as a light-shielding ink. However, the light-shielding portion3may not necessarily be formed by a printing method. For example, a separately prepared light-shielding portion3may be bonded to the transparent plate2. Further, the light-shielding portion3may be formed by various thin film formation methods.

The first adhesive layer4is to bond the adhesive layer-equipped transparent plate1to a transparent support, such as a window glass. As shown inFIG. 2, the first adhesive layer4is provided on the first surface2aas a side to be bonded to the transparent support, between the two surfaces2aand2bof the transparent plate2. The first adhesive layer4is constituted by a transparent resin sheet obtained by curing, e.g., the after-mentioned liquid photocurable resin composition. Further, a touch sensor (not shown) may be provided between the adhesive layer-equipped transparent plate1and the first adhesive layer4.

As shown inFIG. 3, the first adhesive layer4does not cover the entire first surface2aof the transparent plate2and is not provided on some regions of the first surface2a. Specifically, the first surface2ahas two portions2cwith no first adhesive layer4formed therein in parts of a region along each of two opposing long sides of the oblong shape forming the planar shape. Thus, the transparent plate2has four portions2cformed in the periphery of the first surface2aso that the first surface2ais exposed from the first adhesive layer4. In this specification, the portions2cwhere the first surface2ais exposed from the first adhesive layer4in regions without the first adhesive layer4, and portions2cwhere the second surface2bis exposed from the after-mentioned second adhesive layer5in regions without the second adhesive layer5are called exposed portions2c. InFIG. 3, the first surface2ahas two exposed portions2cformed along a long upper side thereof so as to be apart from each other. Likewise, the first surface2ahas two exposed portions2cformed along a long lower side thereof so as to be apart from each other.

The width W of the exposed portions2c(the size in a short side direction of the first surface) is about 1 to about 5 mm, for example. The length L of the exposed portions2c(the size in a long side direction of the first surface) is about 10 to about 30 mm, for example. The dimensions of the exposed portions2cis preferred to be determined to prevent a worker’ fingers from being brought into substantial contact with the first adhesive layer4when he or she places his or her hand on an end surface2fof the transparent plate2to handle the adhesive layer-equipped transparent plate1. Although the shape of the exposed portions2cis rectangular in this embodiment, the shape of the exposed portions may, for example, be another shape, such as a polygonal shape or a semicircular shape, or an irregular shape.

The first adhesive layer4may be obtained by curing a photocurable resin composition, a thermosetting resin composition, a photocurable and thermosetting resin composition, for example. The term “photocurable resin composition” means a resin composition that is curable by exposure. The term “thermosetting resin composition” means a resin composition that is curable by heat. The term “photocurable and thermosetting resin composition” means a resin composition that is curable by exposure and heat. The term “exposure” means light irradiation, such as an ultraviolet ray irradiation. The curable composition is preferably a photocurable resin composition because of being curable at a low temperature and having a high curing speed.

The shear storage modulus of the first adhesive layer4at 25° C. for a frequency of 1 Hz is preferably within a range of from 5×102to 1×107Pa, more preferably within a range of from 1×103to 1×106Pa. When the shear storage modulus of the first adhesive layer4is at least 5×102Pa, the shape of the first adhesive layer4tends to be maintained. Further, when the shear storage modulus of the first adhesive layer4is at least 5×102Pa, the transparent plate2and a member bonded to the second adhesive layer5on the transparent plate2can be sufficiently fixed to the transparent support, and at the time of bonding the adhesive layer-equipped transparent plate1and the transparent support, the first adhesive layer4will be less likely to be deformed by, e.g., the pressure at the time of bonding, such being desirable. On the other hand, when the shear storage modulus of the first adhesive layer4is at most 1×107Pa, even if air bubbles are formed at the time of bonding the adhesive layer-equipped transparent plate1and the transparent support, such air bubbles will disappear in a short time and will be less likely to remain, such being desirable.

The thickness of the first adhesive layer4is preferably from about 0.1 to about 2.0 mm, more preferably from about 0.2 to about 1.0 mm. When the thickness of the first adhesive layer4is at least 0.1 mm, the first adhesive layer4will effectively absorb, e.g., a shock by an external force from the transparent support side, and can thereby protect the display device main body. Further, even if a foreign matter not exceeding the thickness of the first adhesive layer4is included between the transparent support and the adhesive layer-equipped transparent plate1, the thickness of the first adhesive layer4will not change substantially, and there will be little influence to the light transmitting performance. When the thickness of the first adhesive layer4is at most 2.0 mm, it becomes easy to bond the transparent plate2to the transparent support via the first adhesive layer4, and the entire thickness of the display device will not become unnecessarily thick.

The photocurable resin composition is preferably of a solvent-free type since it is not necessary to perform heating for removal of a solvent. The term “solvent-free type” means that no solvent is contained, or that the content proportion of a solvent is at most 5 mass % in the total mass of the photocurable resin composition (100 mass %). The term “solvent” means a liquid having a boiling point of at most 150° C. (volatile diluent). Most preferably, the photocurable resin composition contains no solvent in terms of eliminating a drying step and saving fabrication time and energy. The curable composition typically contains a curable compound having a curable compound (A) and a photopolymerization initiator (B). The curable composition may contain another non-curable component in addition to the photopolymerization initiator (B) as the case requires. As the non-curable component, a non-curable polymer (C), a chain transfer agent (D) and another additives may be mentioned.

As examples of the curable compound (A), an acrylic compound, a silicone compound, a urethane acrylate compound and an epoxy compound may be mentioned. Among them, a silicone compound or a urethane acrylate compound is preferred as the curable compound (A) because it is easy to control the storage modulus G′ of the first adhesive layer4to a value from 5×102to 1×107Pa. Further, the curable compound (A) is more preferably a urethane acrylate one because it is easy to control the gel fraction of the first adhesive layer4to a value from 1 to 50%.

The second adhesive layer5into bond the adhesive layer-equipped transparent plate1to the display device main body. The second adhesive layer5is provided on the second surface2bas a side to which the display device main body is to be bonded, between the two surfaces2aand2bof the transparent plate2. As described above, the second adhesive layer5has a smaller area than the first adhesive layer4. Specifically, the second adhesive layer5is provided in a central portion of a rectangular shape as the planar shape of the second surface2bwithout being provided on the periphery along the four sides of the rectangular shape, whereas the first adhesive layer4is provided on the entire first surface2aexcept for the four exposed portions2c.

The material constituting the second adhesive layer5may be the same as or different from the material constituting the first adhesive layer4. Since the second adhesive layer5is bonded to a display panel of a display device, it is preferably bonded without voids under a smaller bonding pressure so as not to impair the display panel. Accordingly, a measure, such as a measure to increase the content of the non-curable component in the curable compound, or a measure to adjust the content of the chain transfer agent, may be adopted. Further, the second adhesive layer5may contain an ultraviolet absorber in a smaller amount than the first adhesive layer4since external light which has been transmitted through the first adhesive layer4and the transparent plate2enters the second adhesive layer.

The thickness of the second adhesive layer5may be the same as or different from that of the first adhesive layer4. Specifically, the second adhesive layer5may be thinner than the first adhesive layer4, and the thickness of the second adhesive layer5may be about half the thickness of the first adhesive layer4. The reason is that the second adhesive layer5interposed between the display device main body and the transparent plate is not required to have shock-absorbing properties at the same level as the first adhesive layer4interposed between the transparent plate and a transparent support, such as a window glass.

The shear storage modulus of the second adhesive layer5may be the same as or different from that of the first adhesive layer4. Since the second adhesive layer5is directly in contact with the display device, it is preferred to take a measure to use a material capable of forming an adhesive layer with a smaller shear storage modulus, or a measure to make the second adhesive layer5thick, in a case where the uniformity of the display image may be impaired by bonding the transparent plate to a display surface, such as a case of an IPS mode liquid crystal display device.

As shown inFIG. 2, the second adhesive layer5is provided on both a region surrounded by the frame-form light-shielding portion3and a region planarly overlapping with a part of the light-shielding portion3, on the second surface2bof the transparent plate2. Since the second adhesive layer5is bonded to a portion corresponding to the image display region of the display device main body, it may be provided only on the region surrounded by the light-shielding portion3, i.e. a region on the inner side of the light-shielding portion3. However, in a case where the second adhesive layer5planarly overlaps with a part of the light-shielding portion3as in this embodiment, the region where the second adhesive layer5planarly overlaps with a part of the light-shielding portion3functions as an alignment margin at the time of position adjustment between the second adhesive layer5and the light-shielding portion3. Accordingly, even if the second adhesive layer5and the light-shielding portion3are somewhat misaligned, the second adhesive layer5will readily be formed on the region surrounded by the light-shielding portion3. Thus, the display device main body is fixed to the transparent plate2with a sufficiently high strength, and in addition, the edge of the second adhesive layer5is shielded by the light-shielding portion3, whereby a decrease in the display quality by the sight of the edge of the second adhesive layer5will not occur.

(First Protective Film and Second Protective Film)

The first protective film6is to protect the first adhesive layer4when the adhesive layer-equipped transparent plate1is not in use, and the first protective film is peeled from the first adhesive layer4when the adhesive layer-equipped transparent plate is used. Likewise, the second protective film7is to protect the second adhesive layer5when the adhesive layer-equipped transparent plate1is not in use, and the second protective film is peeled from the second adhesive layer5when the adhesive layer-equipped transparent plate is used. Accordingly, the first protective film6and the second protective film7are required not to be strongly contact-bonded to the first adhesive layer4or the second adhesive layer5. From such a viewpoint, it is preferred to use, as the first protective film6and the second protective film7, a protective film including a base film having a relatively low adhesion to the first adhesive layer or the second adhesive layer and made of polyethylene, polypropylene, a fluorinated resin or the like, for contact with the first adhesive layer4or the second adhesive layer5.

The adhesion on the adhesive face of each of the first protective film6and the second protective film7is preferably from 0.01 to 1 N, more preferably from 0.02 to 0.6 N, with a test specimen having a width of 50 mm in 180° peel test at a peel rate of 300 mm/min with respect to an acrylic plate. The suitable thickness of each of the first protective film6and the second protective film7varies depending upon a resin used, and is preferably from 0.03 to 0.2 mm, more preferably from 0.06 to 0.1 mm in a case of using a relatively flexible film of, e.g., polyethylene or polypropylene. When the thickness is at least 0.04 mm, deformation of the protective film can be reduced when the protective film is peeled from the adhesive layer. When the thickness is at most 0.2 mm, the protective film is likely to sag at the time of peeling and is easily peeled.

In order that the first and second protective films are more easily peeled from the first adhesive layer4and the second adhesive layer5, a release agent, such as silicone, may be applied to the first protective film6and the second protective film7within a range not to impair the first adhesive layer4and the second adhesive layer5. It is preferred to use, as the first protective film6and the second protective film7, protective films having a larger size than the transparent plate2, in order that the edges of the first protective film6and the second protective film7are easily held when the first and second protective films are peeled from the first adhesive layer4and the second adhesive layer5.

FIG. 4is a cross-sectional view illustrating a display device including the adhesive layer-equipped transparent plate1according to the first embodiment.FIG. 5is an enlarged cross-sectional view of the portion B inFIG. 4.

As shown inFIGS. 4 and 5, the display device10according to the first embodiment includes the display device main body11, the adhesive layer-equipped transparent plate1and the transparent support12. The transparent support12is bonded to a first surface1aof the adhesive layer-equipped transparent plate1having the first adhesive layer4provided thereon. The display device main body11is bonded to a second surface1bof the adhesive layer-equipped transparent plate1. In the first embodiment, there is no particular limitation to the transparent support so long as the transparent support has a certain supporting force. The transparent support12may be a window glass used in, e.g., a store or an office. The display device main body11is, e.g., a liquid crystal display device. The adhesive layer-equipped transparent plate1has the first protective film6and the second protective film7peeled from the adhesive layer-equipped transparent plate1shown inFIG. 2. The transparent plate2is bonded to the transparent support12via the first adhesive layer4. The display device main body11is bonded to the transparent plate2via the second adhesive layer5. Further, an adhesive layer-equipped transparent plate1having a touch sensor (not shown) provided on the transparent support12side of the transparent plate2may be used. In such a case, the display device10may be operated by touching the display device10from the outside of the transparent support12. In such a case, the transparent support12may be a lenticular sheet. The lenticular sheet is commonly configured to have a lenticular lens provided on a surface to which light enters (the first adhesive layer4side) and, in order to spread display light in a perpendicular direction, to have a diffusion sheet laminated on a surface from which light emits (observer’ side). It becomes possible to control the expansion of a display image and further provide a stereoscopic effect to the display image by using such a lenticular sheet as the transparent support12.

As shown inFIG. 5, the display device main body11includes a liquid crystal panel14, a pair of polarizing plates15and16, a backlight17(lighting unit), a frame18and a case19. The liquid crystal panel14includes a pair of glass substrates21and22, and a liquid crystal (not shown) sealed in between the glass substrates21and22. The drive system of the liquid crystal panel14is not particularly limited, and for example, a liquid crystal panel driven by transverse field, such an in-plane switching mode may be mentioned. The pair of glass substrates21and22includes a TFT element substrate equipped with a thin film transistor (TFT) and a color filter substrate equipped with a color filter.

The polarizing plates15and16are bonded to both the surfaces of the liquid crystal panel14to sandwich the liquid crystal panel14therebetween. Further, an optical film, such as a wave plate, may be disposed between the liquid crystal panel14and each of the polarizing plates15and16. The polarizing plate16on the opposite side from the backlight17, between the polarizing plates15and16, is bonded to the transparent plate2via the second adhesive layer5, whereby the liquid crystal panel14is fixed to the transparent support12.

The backlight17includes a light-emitting device23, such as a light-emitting diode (LED), a light guide plate24, a plurality of optical films25, such as a prism sheet and a light diffusion sheet, and a mirror26. Light emitted from the light emitting device23is reflected on the mirror26while it enters the light guide plate24and is emitted via the optical films25toward the liquid crystal panel14. The optical films25have a function to equalize the intensity of light emitted from the light guide plate24. Accordingly, the optical films25and the liquid crystal panel14are disposed, being apart from each other.

Since the liquid crystal panel14is relatively light in weight, it is supported on the transparent support12by bonding the image display region portion of the liquid crystal panel14to the transparent support12via the adhesive layer-equipped transparent plate1. However, because the backlight17is heavy, even if the liquid crystal panel14and the backlight17are fixed, the entire display device main body11can hardly be supported on the transparent support12only by bonding the liquid crystal panel14to the transparent support12. From this point of view, it is preferred to make the backlight17among the members constituting the display device main body11, supported on the transparent support12separately from the liquid crystal panel14.

As a member to support the backlight17on the transparent support12, in the case of the first embodiment, the backlight17is fixed to the adhesive layer-equipped transparent plate1by an angle28(support member) with an L-shaped cross section. More specifically, the angle28to fix the backlight17is fixed to the light-shielding portion3on the second surface2bof the transparent plate2by a double-coated adhesive tape29. The backlight17is fixed to the frame18, and the frame18is fixed to the case19. The case19is fixed to the angle28by a bolt30. By the above constitution, the backlight17is fixed to the transparent support12via the adhesive layer-equipped transparent plate1. It is possible to firmly fix the display device main body11including the backlight17by adopting an arrangement that the angle28is fixed to the light-shielding portion3by the double-coated adhesive tape29with the light-shieling portion3being partly exposed as mentioned above.

As a procedure to bond the display device main body11to the transparent support12, the first protective film6is peeled from the adhesive layer-equipped transparent plate1, the adhesive layer-equipped transparent plate1is bonded to the transparent support12, and then the second protective film7is peeled, and the display device main body11is bonded to the adhesive layer-equipped transparent plate1bonded to the transparent support12. Otherwise, the second protective film7is peeled from the adhesive layer-equipped transparent plate1, the adhesive layer-equipped transparent plate1is bonded to the display device main body11, and then the first protective film6is peeled, and the display device main body11with the adhesive layer-equipped transparent plate1bonded thereto is bonded to the transparent support12.

At the time of bonding to the transparent support12, the adhesive layer-equipped transparent plate1, or the adhesive layer-equipped transparent plate1with the display device main body11bonded thereto may be bonded while it is curved entirely or locally. In such a case, it is preferred to bond the adhesive layer-equipped transparent plate1alone to the transparent support12first, since the adhesive layer-equipped transparent plate1is easily curved.

On the other hand, in some cases, the display device main body11bonded to the transparent support12is to be peeled from the transparent support12. In such a case also, the bonded object is peeled while it is curved in some cases, and the display device main body11may be peeled from the adhesive layer-equipped transparent plate1first and then the adhesive layer-equipped transparent plate1may be peeled from the transparent support12. Accordingly, the interfacial adhesive strength between the first adhesive layer4and the transparent support12and the interfacial adhesive strength between the first adhesive layer4and the transparent plate2are preferably larger than those between the second adhesive layer and the display device main body11and between the second adhesive layer and the transparent plate2. Otherwise, the adhesive layer-equipped transparent plate1with the display device main body11bonded thereto first may be peeled from the transparent support12, following peeling the adhesive layer-equipped transparent plate1from the display device main body11.

Further, it is preferred that after the adhesive layer-equipped transparent plate1is peeled, the first adhesive layer4will not remain on the transparent support12, and the transparent support12, i.e., a window glass will be restored to its original state before the display device main body11is bonded. Accordingly, the interfacial adhesive strength between the first adhesive layer4and the transparent support12is preferably smaller than that between the first adhesive layer4and the transparent plate2. In order to realize such a degree of the adhesive forces, the adhesive forces may be adjusted by the proportions of monomer components in the curable compound (A), and the contents of the non-curable component and the chain transfer agent, as materials constituting the first adhesive layer4and the second adhesive layer5. In a case where an object to be bonded is a glass plate, the interfacial adhesive strength can be increased by a measure to, for example, reduce the content of the non-curable component. Further, the adhesive strength to a glass surface can be also increased by increasing the content of the chain transfer agent.

In the adhesive layer-equipped transparent plate1according to the first embodiment, the transparent plate2has the two exposed portions exposed portions2cformed along each of the two opposing long sides of the first surface2aso as to be apart from each other. Accordingly, when the operation for bonding the adhesive layer-equipped transparent plate1to the transparent support12is performed, it is possible to increase the workability and easy to perform the bonding operation in comparison with before. For example when a large size of adhesive layer-equipped transparent plate1is bonded to a window glass, it is assumed that two workers hold the adhesive layer-equipped transparent plate1by hands, directing the first surface2adownward. In this case, a worker holds the adhesive layer-equipped transparent plate1so as to catch, with his or her fingers, the two righthand exposed portions2cshown inFIG. 3, and the other worker holds the adhesive layer-equipped transparent plate1so as to catch, with his or her fingers, the two lefthand exposed portions2cshown inFIG. 3, whereby it is possible to reduce the possibility of adherence of the adhesive to the workers' hands and to increase the workability. Thus, the adhesive layer-equipped transparent plate1according to the first embodiment can improve handling performance during transport or working in comparison with the conventional adhesive layer-equipped transparent plates.

Further, even when the operation for peeling the adhesive layer-equipped transparent plate1from the transparent support12is performed, it is possible to improve the workability and to easily perform the peeling operation in comparison with before. For example, since the conventional adhesive layer-equipped transparent plates have had a first adhesive layer4provided entirely on a first surface2aof a transparent plate2, there has been no clearance between the transparent plate1and the transparent support12where a work places a jig or his or her fingers for the peeling operation. It has been troublesome and has taken much time to perform the peeling operation. In contrast, since the exposed portions2cprovide clearances between the transparent plate1and the transparent support12according to the conventional adhesive layer-equipped transparent plate1according to the first embodiment, a worker can place a jig or his or her fingers into the clearances to peel the adhesive layer-equipped transparent plate1from the transparent support12.

The display device10according to this embodiment includes the above-mentioned adhesive layer-equipped transparent plate1, the transparent support12and the display device main body11, resulting in being excellent in display quality.

Further, in the display device10according to the first embodiment, since the light-shielding portion3surrounding the image display region is provided on the adhesive layer-equipped transparent plate1, accessary parts, such as wiring members connected to the liquid crystal panel14, can be shielded without newly providing a light-shielding portion. Particularly in the first embodiment, since the light-shielding portion3is provided on the second surface2bof the transparent plate2, the distance between the light-shielding portion3and the image display surface in a depth direction is short. Thus, an observer will not feel that display looks far at the back with respect to a frame portion consisting of the light-shielding portion3, and a decrease in visibility of the display by a difference in level of the frame portion and the image display surface can be prevented.

It should be noted that instead of the arrangement according to the first embodiment, for example, the second adhesive layer5may be provided on the entire second surface2bof the transparent plate2. Even in this case, it is possible to improve handling performance so long as the transparent plate2has exposed portions provided on the first surface2aas in the above-mentioned first embodiment.

Second Embodiment

Now, a second embodiment of the present invention will be described with reference toFIGS. 6 to 8.

The adhesive layer-equipped transparent plate according to the second embodiment is basically configured in the same manner as the one according to the first embodiment and is different from the one according to the first embodiment in the arrangement of exposed portions.

FIG. 6is a plan view illustrating the adhesive layer-equipped transparent plate according to the second embodiment as observed from a first surface side.FIG. 6also illustrates a state where a first protective film and a second protective film have been peeled from the adhesive layer-equipped transparent plate.FIG. 7is a schematic view illustrating an example of the method for binding the adhesive layer-equipped transparent plate to a transparent support.FIG. 8is a schematic view illustrating another example of the method for bonding the adhesive layer-equipped transparent plate to the transparent suppose.

InFIGS. 6 to 8, components common to the ones used in the first embodiment and shown in the relevant figures are represented by the same symbols, and their detailed description will be omitted.

As shown inFIG. 6, the adhesive layer-equipped transparent plate31according to the second embodiment has two exposed portions2cprovided along each of two long sides of a first surface2aof a transparent plate2so as to be apart from each other. Further, the transparent plate2has two exposed portions2jprovided along one of the short sides of the first surface2athereof so as to be apart from each other. The form and dimensions of the exposed portions2jalong the one short side may be the same as or different from those of the exposed portions2calong the long sides. The other features of the adhesive layer-equipped transparent plate31are the same as the ones according to the first embodiment.

As one example of the method for bonding the adhesive layer-equipped transparent plate31to the transparent support12, is mentioned a method for bonding the adhesive layer-equipped transparent plate31to the transparent support12, pressing the adhesive layer-equipped transparent plate against the transparent support in a state where the adhesive layer-equipped transparent plate31is bent, being supported by an arbitrary measure, as shown inFIG. 7. In the example shown inFIG. 7, the adhesive layer-equipped transparent plate31is bonded to the transparent support12from one edge of the first surface2afirst, and then is fully bonded to the transparent plate12, being pressed against the transparent support by holding the other edge of the first surface2aby a holder33to keep the other edge out of touch from the transparent support12and moving a roller34in a long side direction of the first surface from the one edge to the other edge.

According to such a method, it is possible to minimize the entry of air bubbles into the interface between the adhesive layer-equipped transparent plate31and the transparent support12to uniformly bond the adhesive layer-equipped transparent plate31to the transparent support12. It should be noted that the direction to move the roller34may be either one of the long side direction and the short side direction of the adhesive layer-equipped transparent plate31, and that the direction is preferred to be the long side direction of the adhesive layer-equipped transparent plate31from the viewpoint of easy bending of the adhesive layer-equipped transparent plate31.

In the adhesive layer-equipped transparent plate31according to the second embodiment, it is possible to improve the handling performance of the adhesive layer-equipped transparent plate31as in the first embodiment since the transparent plate2has the two exposed portion2cprovided along each of the two opposing long sides of the first surface2aas in the first embodiment.

Further, since the transparent plate2has the two exposed portions2jprovided along one of the short sides of the first surface2a, it is possible to reduce the possibility of adherence of the adhesive to the holder33at the time of hooking the holder33on the exposed portions2jas shown inFIG. 7. Thus, it is possible to easily perform the bonding operation by use of the above-mentioned method.

Further, even when the adhesive layer-equipped transparent plate31is peeled from the transparent support12, the adhesive layer-equipped transparent plate31can be peeled from the transparent support12by placing a jig or fingers on the exposed portions2cand2jand applying forces to bend the adhesive layer-equipped transparent plate. In this case also, it is possible to minimize the possibility of adherence of the adhesive to the jig or fingers and to easily perform the peeling operation.

As another example of the method for bonding the adhesive layer-equipped transparent plate31to a transparent support, is mentioned a method for bonding the adhesive layer-equipped transparent plate31to the transparent support12by sucking or chucking the adhesive layer-equipped transparent plate31by a sucking or chucking jig35and pressing the adhesive layer-equipped transparent plate31as well as the sucking or chucking jig35to the transparent support12as shown inFIG. 8. When the sucking or chucking jig35is used, according to the method for chucking the adhesive layer-equipped transparent plate31by the sucking or chucking jig35, the provision of the exposed portions2con the first surface2aof the transparent plate2is preferred in some cases, and the provision of the exposed portions on the second surface2bof the transparent plate2is preferred in the other cases.

When the adhesive layer-equipped transparent plate31is sucked or chucked to the sucking or chucking jig35, there are a method where a worker places the adhesive layer-equipped transparent plate31on, e.g., a desk and brings the sucking or chucking jig35into contact with the adhesive layer-equipped transparent plate31from upward, and a method where a worker places the sucking or chucking jig35on, e.g., a desk and places the adhesive layer-equipped transparent plate31on the sucking or chucking jig35.

In the former case, it is preferred to provide the exposed portions2con the opposite side of the adhesive layer-equipped transparent plate31from a side with the sucking or chucking jig35placed thereon, i.e., on the first surface2aof the transparent plate2as shown inFIG. 8because the holder, fingers or the like are brought into contact with a lower side of the adhesive layer-equipped transparent plate31when the adhesive layer-equipped transparent plate31is placed on the desk. In contrast, in the latter case, it is preferred to provide the exposed portions on the opposite side of the adhesive layer-equipped transparent plate31from a side with the sucking or chucking jig35placed thereon, i.e., the second surface2bof the transparent plate2because the holder, fingers or the like are brought into contact with the lower side of the adhesive layer-equipped transparent plate31when the adhesive layer-equipped transparent plate31is placed on the sucking or chucking jig35.

In either method, it is preferred to provide the exposed portions2cand2jat least on the opposite side of the adhesive layer-equipped transparent plate31from a side with the sucking or chucking jig35placed thereon (on a side to have contact with the transparent support12), i.e., the first surface2aof the transparent plate2, taking easy peeling operation also into consideration.

Third Embodiment

The adhesive layer-equipped transparent plate according to the third embodiment is basically configured in the same manner as the one according to the first embodiment and different from the one according to the first embodiment in terms of the arrangement of exposed portions.

FIG. 9is a plan view illustrating the adhesive layer-equipped transparent plate according to the third embodiment as observed from a first surface side.FIG. 9also illustrates a state where a first protective film and a second protective film are peeled from the adhesive layer-equipped transparent plate.

InFIG. 9, components common to the ones used in the first embodiment and shown in the relative figures are represented by same symbols, and their detailed description will be omitted.

As shown inFIG. 9, the adhesive layer-equipped transparent plate41according to the third embodiment has exposed portions2kprovided in two respective corners of the four corners of a first surface2aof a transparent plate2, which are located across a long side. Each of the exposed portions2kis formed in a triangle shape surrounded by the long side and the short side forming the relevant corner, and a straight line at an angle of 45° to both sides. It should be noted that the shape of the exposed portions2kis not limited to a triangle, and that the shape may be another shape, such as a rectangular shape or fan shape. Further, there is no particular limitation to the dimensions of the exposed portions2k. The other features of the adhesive layer-equipped transparent plate41are the same as those of the adhesive layer-equipped transparent plate according to the first embodiment.

Since the adhesive layer-equipped transparent plate41according to the third embodiment has the exposed portions2kprovided in two corners of the first surface2aof the transparent plate2, which are located across one long side, a worker can place a jig or fingers on these exposed portions2kto apply a force to the adhesive layer-equipped transparent plate, improving workability at the time of, in particular, performing the peeling operation.

Fourth Embodiment

Now, a fourth embodiment of the present invention will be described with reference toFIGS. 10 and 11.

The adhesive layer-equipped transparent plate according to the fourth embodiment is basically configured in the same manner as that according to the first embodiment and is different from that of first embodiment in terms of the arrangement of an exposed portion.

FIG. 10is a plan view illustrating the adhesive layer-equipped transparent plate according to the fourth embodiment as observed from a first surface side.FIG. 10also illustrates a state where a first protective film and a second protective film have been peeled from the adhesive layer-equipped transparent plate.

InFIG. 10, components common to those used in the first embodiment and shown in the relevant figures are represented by the same symbols, and their detailed description will be omitted.

As shown inFIG. 10, the adhesive layer-equipped transparent plate51according to the fourth embodiment has an exposed portions2mprovided in a region along the four sides of a first surface2aof a transparent plate2. The width of the exposed portion2mmay be formed such that the width W1of a part of the exposed portion along a long side is the same as or different from and the width W2of a part of the exposed portion along a short side. The other features of the adhesive layer-equipped transparent plate51are the same as that of the adhesive layer-equipped transparent plate according to the first embodiment.

According to this embodiment also, it is possible to have the same effects as in the first to the third embodiments, such as improvement in the handling performance of the adhesive layer-equipped transparent plate51, and easy bonding operation and peeling operation for the adhesive layer-equipped transparent plate51.

Further, the adhesive layer-equipped transparent plate51according to the fourth embodiment has advantageous effects as described below. When the adhesive layer-equipped transparent plate51is produced, a first adhesive layer4made of a transparent resin sheet is separately fabricated, and the first adhesive layer4is bonded to a transparent plate2as described with respect to the first embodiment. Supposing that no exposed portion is provided as shown inFIG. 11, when misalignment between a first adhesive layer104and a transparent plate2is caused at a time of bonding the first adhesive layer104to the transparent plate2since the first adhesive layer104and the transparent plate2have the same dimensions, the misalignment causes a problem that the first adhesive layer104protrudes outward from the transparent plate2.

In contrast, the adhesive layer-equipped transparent plate51according to the fourth embodiment has the exposed portion2mprovided in a region along the four sides of the first surface2aof the transparent plate2. According to this arrangement, even if misalignment between the first adhesive layer4and the transparent plate2is caused in any one of a long side direction, a short side direction and a rotation direction at a time of bonding the first adhesive layer4to the transparent plate2, the first adhesive layer4is prevented from protruding outward from the transparent plate2so long as the widths W1and W2of the exposed portion2mare set at values exceeding alignment error between the first adhesive layer4and the transparent plate2. Even if not only the misalignment between the first adhesive layer4and the transparent plate2but also dimensional error between the first adhesive layer4and the transparent plate2is caused, this arrangement can reduce the possibility that the first adhesive layer4could protrude outward from the transparent plate2. These effects improve the productivity of the adhesive layer-equipped transparent plate51.

Fifth Embodiment

Now, a fifth embodiment of the present invention will be described with reference toFIGS. 12 and 13.

The adhesive layer-equipped transparent plate according to the fifth embodiment is basically configured in the same manner as that according to the first embodiment and is different from that according to the first embodiment in terms of the arrangements of a transparent plate and exposed portions

FIG. 12is a cross-sectional view illustrating the adhesive layer-equipped transparent plate according to the fifth embodiment.

InFIG. 12, components common to those used in the first embodiment and shown in the relevant figures are represented by the same symbols, and their detailed description will be omitted.

As shown inFIG. 12, the adhesive layer-equipped transparent plate61according to the fifth embodiment includes a transparent plate9, which has a first surface9aincluding a first flat surface9a1locating at a central area on the transparent plate9, and a first inclined surface9a2inclining to the first flat surface9a1in the periphery of the transparent plate9and having contact with an end surface9fperpendicular to the first flat surface9a1. Likewise, the transparent plate9has a second surface9bincluding a second flat surface9b1locating at a central area on the transparent plate9, and a second inclined surface9b2inclining to the first flat surface9b1in the periphery of the transparent plate9and having contact with the end surface9fperpendicular to the second flat surface9b1. In other words, each of the corners formed by the end surface9f, and the first surface9aand the second surface9bof the transparent plate9is chamfered in a planar shape. It should be noted that although the corners chamfered in a planar shape are exemplified, the transparent plate9may have corners chamfered in a curved and round shape.

In this embodiment, the transparent plate9has exposed portions9cprovided on the first inclined surface9a2and the second inclined surface9b2. In other words, the transparent plate has a first adhesive layer4provided on the first flat surface9a1, but not on the first inclined surface9a2. The transparent plate has a second adhesive layer5provided on the second flat surface9b1, but not on the second inclined surface9b2. Thus, the exposed portions9care provided in a region along the four sides of the first surface9aof the transparent plate9and in a region along the four sides of the second surface9bof the transparent plate in this embodiment as observing the adhesive layer-equipped transparent plate61from a normal direction of the first flat surface9a1, though a relevant plan view is omitted. The other features of the adhesive layer-equipped transparent plate61are the same as those according to the first embodiment.

According to the fifth embodiment also, it is possible to obtain the same effects as the first to fourth embodiments, such as improvement in the handling performance of the adhesive layer-equipped transparent plate61and easy bonding operation and peeling operation for the adhesive layer-equipped transparent plate61.

Further, the adhesive layer-equipped transparent plate61according to the fifth embodiment has an advantageous effect described below.

In contrast, since the adhesive layer-equipped transparent plate61according to the fifth embodiment has the exposed portions9cprovided on the first inclined surface9a2and the second inclined surface9b2of the transparent plate9, the second adhesive layer5is bonded to the transparent plate9at the position where the second protective film7starts being peeled (position represented by symbols D). For this reason, only the second protective film7is peeled from the second adhesive layer5since the fifth embodiment reduces the possibility that the second adhesive layer5is peeled from the transparent plate9, adhering to the second protective film7. Thus, it is possible to improve problems, such as a reduction in the bonding strength and poor appearance in the peripheral edge portion of the adhesive layer-equipped transparent plate61.

The present invention is not limited to the above-mentioned specific embodiments, and various modifications are possible without departing from the sprit and scope of the present invention.

For example, although the above-mentioned embodiments are explained in a case where the transparent plate has the exposed portions mainly provided on the first surface, similar exposed portions may be provided on the second surface, and the exposed portions may be provided on both of the first surface and the second surface.

Although the first embodiment is explained about a case where the exposed portions are provided in a region along each of two opposing long sides of the transparent plate as shown inFIG. 3, the exposed portions may be provided in a region along each of two opposing short sides of the transparent plate. Further, the exposed portions may not be provided in a region along each of two opposing sides, and may be provided in a region along each of two adjacent sides, for example. Although the exposed portions are preferred to be provided in a region along each of two opposing sides in the case of a large size of adhesive layer-equipped transparent plate, an adhesive layer-equipped transparent plate may be handled by use of the exposed portions in a region along each of two adjacent sides so long as the adhesive layer-equipped transparent plate has a small size.

Although explanation has been made about a case where the light-shielding portion is provided on a side of transparent plate facing a display device main body, the light-shielding portion may be provided on a side of the transparent plate facing the transparent support. Further, the transparent plate has the light-shielding portion provided along two opposing upper and lower or right and left sides, for example.

Further, as the transparent support constituting the display device, a window glass to be used in a store, an office or the like is mentioned as an example, however, instead of a window glass, a movable member, such as a glass partition partitioning a room, may be used as the transparent support, and a display device main body is bonded to the transparent support. Furthermore, a lenticular sheet may be used as the transparent support, and a display device main body may be bonded to the lenticular sheet to configure a stereoscopic image display system.

Further, as the display device main body, in addition to the liquid crystal display, an organic EL display, a plasma display, an electronic paper display, etc. may be used. Further, the shape, number, arrangement, material, etc. of each of the elements constituting the adhesive layer-equipped transparent plate and the display device are not limited to the ones of the above embodiments, and various modifications are possible.

INDUSTRIAL APPLICABILITY

The present invention is applicable to various display devices, such as a liquid crystal display, an organic EL display, a plasma display and an electronic paper display, and an adhesive layer-equipped transparent plate used to bond such display devices to a transparent support.

The entire disclosures of Japanese Patent Application No. 2017-244240 filed on Dec. 20, 2017 and Japanese Patent Application No. 2018-177605 filed on Sep. 21, 2018 including specifications, claims, drawings and summaries are incorporated herein by reference in their entireties.