Vacuum adsorption control mechanism device, film pasting device, method of pasting film, and display device

An object of the present invention is to provide a vacuum suction control mechanism apparatus capable of accurately bonding a film to a bonding object with a simple structure. A vacuum suction control mechanism apparatus according to the present invention includes a first member including a plurality of suction holes formed in a surface thereof, the plurality of suction holes being connectable to a decompression source, and a second member capable of contacting the plurality of suction holes, the second member being movable relative to the first member, wherein the second member includes connecting member connecting some of the suction holes, the number of which corresponds to a relative position between the first member and the second member, to the decompression source.

BACKGROUND ART

The present invention relates to a vacuum suction control mechanism apparatus, a film bonding apparatus comprising a vacuum suction mechanism, a film bonding method using a film bonding apparatus, and a display apparatus manufactured by a film bonding method.

A display apparatus using liquid crystal or the like is formed by filling liquid crystal or the like between a pair of substrates such as glasses comprising electrodes for display and bonding a polarization film on a surface of one of the substrates.

Apparatuses for bonding a film on a substrate comprise various types of structures. Some apparatuses use a bonding unit (bonding head) comprising suction holes formed in a surface thereof as shown in Patent Document 1.

Specifically, as described at paragraph [0028] of Japanese laid-open patent publication No. 2001-42315 (Patent Document 1), a suction surface of a film support 22, which comprises a curved shape, is formed by a plate comprising a plurality of suction holes defined therein. Suction valves are connected to the suction holes.

As described at paragraph [0037], the film support 22 is rotated and moved toward a supply device A, which supplies a film. The suction valves are switched so as to exhaust air through the suction holes, thereby attracting the film.

After the attraction of the film, the film support 22 is rotated and moved above a substrate (liquid crystal panel). Then the film is bonded to the substrate.

Thereafter, the suction valves are switched so as to supply air, thereby releasing the suction. Thus, the film support 22 is separated from the substrate.

Furthermore, as described at paragraph [0046], air is blown to the film at the time of the bonding in order to prevent a positional deviation when the film is bonded to the substrate.

DISCLOSURE OF INVENTION

However, in a mechanism thus using vacuum suction to bond a film, suction of a suction hole is controlled with a suction valve. Therefore, it is necessary to provide valves so as to correspond to the number of the suction holes. Thus, the structure is problematically complicated.

Furthermore, a structure for blowing air at the time of attraction or bonding complicates the structure of an apparatus. Moreover, the air blow may cause dust or air to be mixed on a bonding surface. Thus, there is a problem that the bonding accuracy may be lowered.

The present invention has been made in view of the above problems. It is an object of the present invention to provide a vacuum suction control mechanism apparatus capable of accurately bonding a film to a bonding object with a simple structure.

In order to achieve the aforementioned object, a first invention provides a vacuum suction control mechanism apparatus comprising: a first member comprising a plurality of suction holes formed in a surface thereof, the plurality of suction holes being connectable to a decompression source; and a second member capable of contacting the plurality of suction holes, the second member being movable relative to the first member, wherein the second member includes connecting member connecting some of the suction holes, the number of which corresponds to a relative position between the first member and the second member, to the decompression source.

A second invention provides a film bonding apparatus comprising the vacuum suction control mechanism apparatus according to the first invention.

A third invention provides a film bonding method comprising: bonding a film to a bonding object with use of the film bonding apparatus according to the second invention.

A fourth invention provides a display apparatus manufactured by bonding a film to a bonding object with use of the film bonding method according to the third invention.

EFFECTS OF THE INVENTION

According to the present invention, there can be provided a vacuum suction control mechanism apparatus capable of accurately bonding a film to a bonding object with a simple structure.

DESCRIPTION OF REFERENCE NUMERALS

BEST MODE FOR CARRYING OUT THE INVENTION

First, an arrangement of a film bonding apparatus1according to an embodiment of the present invention will be described with reference toFIGS. 1 to 3C.

Here, the film bonding apparatus1is illustrated as an example of a film bonding apparatus for bonding a film of a flexible polarization film to a bonding object of a glass substrate for a liquid crystal panel.

As shown inFIGS. 1 to 3A, the film bonding apparatus1as a vacuum suction control mechanism apparatus comprises a bonding head3, a base member5, a shaft7, and a bonding surface plate15.

As shown inFIGS. 1 to 3A, the film bonding apparatus1includes, as a first member, the cylindrical bonding head3for attracting a film17, which will be described later. The diameter of the bonding head3is selected properly depending upon the dimension of the film17.

The material of the bonding head3is not limited to a specific one. Nevertheless, at least a portion contacting the film17is preferably formed of a material comprising elasticity, more preferably rubber or resin comprising a hardness of 20 to 40 by the standard SRIS 0101.

If the bonding head3is formed of such a material, bonding pressures are equally generated when the film17is bonded onto the glass substrate19. Therefore, the glass is prevented from being broken because of local concentration of the bonding pressures, and the thickness of the glass substrate19can thus be reduced.

Furthermore, since the bonding pressures are equally generated, air bubbles are prevented from being mixed on a bonding surface at the time of bonding. Therefore, low-grade glass comprising poor flatness can be used as a material for the glass substrate19.

The disk-like base member5is provided as a second member on an end face3a(side surface) of the bonding head3.

The base member5may be provided on other surfaces, not on the side surface of the bonding head3.

A structure for preventing leakage of air at the time of pressure reduction, which will be described later, is provided between the bonding head3and the base member5. In order to improve the airtightness and control leakage of air, a seal, which is not shown, may be provided as needed.

The film bonding apparatus1further includes the shaft7provided at the center of axes of the bonding head3and the base member5.

On the other hand, the base member5does not rotate.

Furthermore, the bonding head3, the base member5, and the shaft7can be moved jointly in directions E1, E2, E3, and E4ofFIG. 2by an actuator, which is not shown.

Moreover, the flat bonding surface plate15for holding a bonding object is provided so as to face a surface3bof the bonding head3.

The bonding surface plate15is movable in directions D1and D2ofFIG. 2. The bonding surface plate15may be movable in a vertical direction ofFIG. 2or in a θ-direction (a direction for adjusting the horizontally of the bonding surface plate15).

The material of the bonding surface plate15is not limited to a specific one. Nevertheless, the bonding surface plate15is preferably formed of a material comprising elasticity, more preferably rubber or resin comprising a hardness of 20 to 40 by the standard SRIS 0101, as with the bonding head3.

If the bonding surface plate15is formed of such a material, it is possible to attain the same advantages as in the case where the bonding head3is formed of such a material.

Next, the detailed structures of the bonding head3and the base member5will be described with reference toFIGS. 3A to 5B.

As shown inFIGS. 3A and 4, suction holes9a,9b,9c,9d,9e,9f, and9gare formed in the surface3bof the bonding head3.

The suction holes9a,9b,9c,9d,9e,9f, and9gextend through the bonding head3from the end face3a(side surface) to the surface3b. InFIGS. 3A and 4, a portion of the suction hole extending to the surface3bis illustrated as a suction portion9comprising a widened shape. However, the shape of the suction portion9can be selected properly depending upon the film.

Furthermore, as shown inFIG. 3B, a piece23formed of a porous sheet of metal, resin, sponge, or the like may be provided in the suction portion9.

Provision of the piece23formed of a porous sheet or the like can prevent a mark of the hole from being transferred to the film17at the time of attraction of the film, which will be described later.

For example, the piece23comprises a hole density such that holes comprising a diameter of 1 mm are formed at a pitch of 2 mm.

Meanwhile, the suction holes9a,9b,9c,9d,9e,9f, and9g(on the surface of the end face3afrom which they extend) are arranged (in an arcuate manner) so as to correspond to the shape of a groove11, which will be described later.

Furthermore, a head shaft hole3cthrough which the shaft7passes is formed at the center of the bonding head3.

As shown inFIGS. 3A,5A, and5B, the base member5comprises a groove11formed in a surface facing the bonding head3.

The groove11comprises a shape corresponding to the shape of the surface3bof the bonding head3, i.e., an arcuate shape.

Furthermore, the base member5comprises a hole13extending through the base member5from the groove11to a surface of the base member5opposite to the surface facing the bonding head3.

As shown inFIG. 3C, a hole13amay be formed so as to extend to a side surface of the base member5.

A decompression source such as a vacuum pump, which is not shown, is connected to the hole13.

The position of the hole13can be selected properly based on a positional relationship with the decompression source.

Furthermore, a base shaft hole5athrough which the shaft7passes is formed at the center of the base member5.

Here, as shown inFIG. 3A, when the groove11communicates with the suction hole9a, the hole13is connected to the suction hole9athrough the groove11, so that the suction hole9ais connected to the decompression source.

If the decompression source is operated in this state, air in the suction hole9ais exhausted so that the suction portion9can attract a film.

Meanwhile, when the bonding head3is rotated in the direction C1or C2ofFIG. 2from the state ofFIG. 3Aso as to move the groove11to a position at which the groove11does not communicate with the suction hole9a, the communication between the hole13and the suction hole9ais disconnected. Thus, the communication between the suction hole9aand the decompression source is disconnected.

In this state, air in the suction hole9ais not exhausted. Therefore, the suction portion9cannot attract a film. Accordingly, if the suction portion9has already attracted a film, the film is separated from the suction hole9a.

The suction holes9b,9c,9d,9e,9f, and9gare configured in the same manner as the suction hole9a.

Thus, in the film bonding apparatus1, a desired number of the suction holes among the suction holes9a,9b,9c,9d,9e,9f, and9gare connected to or disconnected from the decompression source by relative positions between the groove11and the suction holes9a,9b,9c,9d,9e,9f, and9g.

Specifically, the groove11of the base member5connects suction holes, the number of which corresponds to relative positions between the groove11and the suction holes9a,9b,9c,9d,9e,9f, and9g, to the decompression source.

Next, a method bonding the film17onto the glass substrate19with use of the film bonding apparatus1will be described with reference toFIGS. 6 to 11.

Bonding of the film17onto the glass substrate19with the film bonding apparatus1requires a process of attracting the film17to the bonding head3and a process of bonding the film17on the bonding head3to the glass substrate19.

First, the process of attracting the film17to the bonding head3will be described with reference toFIGS. 6 to 8.

The film17is first placed on the bonding surface plate15and held in a flat state.

The film17has been bonded to a mount19a. An adhesive layer, which is not shown, is provided on a surface of the film17that contacts the mount19a.

Available known member can be used holding the film17. For example, the film17is held by vacuum suction or a clamp.

Then the bonding head3is rotated relative to the base member5in the direction C1or C2ofFIG. 2. As shown inFIG. 6, the bonding head3is positioned so that the groove11communicates only with the suction hole9g.

In this state, the bonding head3(along with the base member5and the shaft7) is moved in the direction E2, E3, or E4ofFIG. 2so as to bring the suction hole9ginto contact with a surface of a left edge of the film17. Then the decompression source, which is not shown, is operated.

During the movement, the position of the edge of the film17is measured by a sensor, a camera, or the like, which is not shown. Based on the measured position, an actuator, which is not shown, is operated to move the bonding head3(along with the base member5and the shaft7).

The bonding surface plate15, rather than the bonding head3, may be moved to bring the suction hole9ginto contact with the surface of the left edge of the film17.

Since the groove11communicates only with the suction hole9g, only air in the suction hole9gis exhausted. Thus, the surface of the edge of the film17is attracted to the surface3bof the bonding head3.

The suction force depends upon the surface roughness and the flexibility of the film17. In the case of a polarization film for a liquid crystal panel as in the present embodiment, it is preferable to adjust a suction force in a range of about 2.0×104Pa to about 4.9×104Pa.

Next, the bonding head3is rotated from the state ofFIG. 6in the direction C1ofFIG. 6. Furthermore, the bonding surface plate15is moved toward the direction D2ofFIG. 6in synchronism with the rotation of the bonding head3.

The suction holes9f,9e,9d,9c,9b, and9aare brought into contact with the film17in the order named. The suction holes communicate with the groove11and are connected to the decompression source in the order in which they have been brought into contact with the film17. Sequentially, air is exhausted, so that the suction holes attract the film17.

In other words, the film bonding apparatus1attracts the film17merely by bringing the bonding head3into contact with the film17and rotating the bonding head3.

For example,FIG. 7shows the attraction in progress. The suction holes9g,9f,9e, and9dcommunicate with the groove11and are connected to the decompression source. Air in the suction holes9g,9f,9e, and9dis drawn, so that the suction holes9g,9f,9e, and9dattract the film17.

Those suction holes have been brought into contact with the film17. Those suction holes communicate with the groove11in the order in which they have been brought into contact with the film17. Thus, the suction holes9g,9f,9e, and9dattract the film17.

As shown inFIG. 8, when all of the suction holes communicate with the groove11, the bonding head3(along with the base member5and the shaft7) is moved toward the direction E1ofFIG. 2and separated from the bonding surface plate15.

In order to thus attract the film17with the film bonding apparatus1, relative positions between the suction holes and the groove11are arranged such that the suction holes communicate with the groove11and are connected to the decompression source for attracting the film17in the order in which they have been brought into contact with the film17.

With such an arrangement, the film17can be attracted to the bonding head3with accuracy without deviation at the time of the attraction.

In the above process, the film17is peeled from the mount19aat the same time it is attracted. However, the film17may be attracted together with the mount19a, and the mount19amay be peeled later.

Furthermore, in the above process, the bonding surface plate15holds the film17to be attracted. However, the film17to be attracted may be held on a surface plate other than the bonding surface plate15.

Next, a process of bonding the attracted film17onto the glass substrate19will be described with reference toFIGS. 9 to 11.

First, as shown inFIG. 9, the glass substrate19is held on the bonding surface plate15. The same holding members holding the film17may be used.

For the bonding surface plate15, a common bonding surface plate may be used both holding the film17when the bonding head3attracts the film17and for holding the glass substrate19as described here. Alternatively, separate bonding surface plates may be used.

Next, the bonding head3(along with the base member5and the shaft7) that has attracted the film17is moved in the directions E2, E3, and E4ofFIG. 2so that the suction hole9ais brought into contact with a surface of the glass substrate19at a desired bonding location.

During the movement, the position of the edge of the glass substrate19is measured by a sensor, a camera, or the like, which is not shown. Based on the measured position, an actuator, which is not shown, is operated to move the bonding head3(along with the base member5and the shaft7).

The bonding surface plate15, rather than the bonding head3, may be moved to bring the suction hole9ainto contact with the desired bonding location of the glass substrate19.

Then the bonding head3is rotated in the direction C2. Furthermore, the bonding surface plate15is moved toward the direction D1ofFIG. 9in synchronism with the rotation of the bonding head3.

The suction holes9b,9c,9d,9e,9f, and9gare brought into contact with the glass substrate19via the film17in the order named. The communications of the suction holes9b,9c,9d,9e,9f, and9gwith the groove11are cut off in that order.

In other words, the communications of the suction holes with the groove11are cut off in the order in which the suction holes have been brought into contact with the glass substrate19. The suction holes are disconnected from the decompression source, losing a suction force. Therefore, the suction holes are separated from the film17.

Accordingly, the film17is bonded to the glass substrate19from a portion separated from the suction holes by release of the attraction.

For example,FIG. 10shows the bonding in progress. The suction holes9g,9f,9e, and9dcommunicate with the groove11and are connected to the decompression source. Air in the suction holes9g,9f,9e, and9dis drawn, so that the suction holes9g,9f,9e, and9dattract the film17.

Those suction holes have not been brought into contact with the glass substrate19via the film17. The communications of those suction holes with the groove11are cut off so that the suction holes lose a suction force to the film17in the order in which the suction holes have been brought into contact with the glass substrate19.

A suction force prior to the cut-off is maintained immediately after the communication has been cut off. Therefore, the film17is held on the bonding head3until it is bonded.

As shown inFIG. 11, when the bonding of the film17is completed, the rotation of the bonding head3and the suction of the decompression source are stopped.

Then the bonding head3(along with the base member5and shaft7) is moved upward inFIG. 2and separated from the bonding surface plate15.

Thus, the film17is bonded to the glass substrate19, and a liquid crystal panel is completed.

For reference purposes,FIG. 12shows a display apparatus27manufactured by bonding a polarization plate to liquid crystal panels with use of the film bonding apparatus1.

In the display apparatus27shown inFIG. 12, a polarization plate25is bonded to liquid crystal panels26with use of the film bonding apparatus1.

As described above, when the film17is bonded to the glass substrate19, the communications of the suction holes with the groove11are cut off in the order in which the suction holes have been brought into contact with the glass substrate19via the film17. Thus, the suction holes are separated from the film17. Specifically, the communications are cut off at (or near) a portion at which the film17is brought into contact with the glass substrate.

Therefore, deviation of the film17or mixing of air or dust is prevented during the bonding. Accordingly, the film17can be bonded with accuracy.

Thus, according to the present embodiment, the film bonding apparatus1includes a bonding head3comprising a plurality of suction holes and a base member5comprising a groove11. The individual suction holes are connected to or disconnected from a decompression source by relative positions between the groove11and the individual suction holes.

Therefore, the film bonding apparatus1does not require a plurality of valves for suction control. Thus, the film bonding apparatus1comprises a simple structure.

Furthermore, no air needs to be blown. Therefore, deviation of the film17or mixing of air or dust is prevented during the bonding. Accordingly, the film17can be bonded with accuracy.

Moreover, when the film bonding apparatus1is used to bond the film17onto the glass substrate19for manufacturing a display apparatus, the quality of the manufactured display apparatus can be improved.

EXAMPLE

The present invention will specifically be described below based on an example.

In an example of the present invention, a film bonding apparatus1shown inFIG. 1was prepared. A polarization film was bonded to a glass substrate19comprising a diagonal of 2 inches to 60 inches.

The polarization film used for bonding had a surface roughness such that 0.3 μm≦Ra≦3.0 μm. The thickness of the polarization film was in a range of from 0.1 mm to 0.5 mm.

Furthermore, a suction force of each suction hole at the time of bonding was set in a range of from about 2.0×104Pa to about 4.9×104Pa.

As a result, it was confirmed that the polarization film did not fall off from the bonding head3during the bonding and that there is no trouble in the slide of the polarization film at the time of the bonding.

In the aforementioned embodiment, the present invention is applied to an apparatus for bonding a polarization film to a liquid crystal display substrate. However, the present invention is not limited to that example and is applicable to any apparatus for bonding a film to a bonding object.

Furthermore, in the above embodiment, the base member5is not rotated while the bonding head3is rotated. Conversely, the base member5may be rotated.

Moreover, the bonding head3comprises a cylindrical shape in the above embodiment. However, the shape of the bonding head3is not limited to a cylindrical shape. The bonding head3may comprise any shape as long as a surface with suction holes comprises a curved shape.

Furthermore, according to another embodiment of the vacuum suction control mechanism apparatus of the present invention, the surface of the first member may comprise a curved shape, the second member may include a groove provided on a surface of the second member facing the first member, the groove may comprise a shape corresponding to the curved shape, the second member may comprise a hole extending through the second member from the groove to an exterior of the second member, the hole may be connected to the decompression source, the plurality of suction holes may be arranged to comprise an arrangement shape corresponding to the shape of the groove, the first member or the second member may be movable along a curved surface of the curved shape, and the groove of the second member may be moved relative to the first member so that the suction holes that communicate with the groove are connected to the decompression source by movement of the first member or the second member.

According to still another embodiment of the vacuum suction control mechanism apparatus of the present invention, the first member may comprise a cylindrical shape, the groove may comprise an arcuate shape, the plurality of suction holes may be arranged in an arcuate manner, the first member or the second member may be rotatable about an axis of the cylinder, and the groove of the second member may be moved relative to the first member so that the suction holes that communicate with the groove are connected to the decompression source by rotation of the first member or the second member about the axis of the cylinder.

According to another embodiment of the vacuum suction control mechanism apparatus of the present invention, the plurality of suction holes may extend through the first member from a side surface to a surface of the first member.

According to still another embodiment of the vacuum suction control mechanism apparatus of the present invention, the first member may comprise a bonding head configured to hold a film, and the second member may comprise a base member provided on a side surface of the bonding head.

According to another embodiment of the vacuum suction control mechanism apparatus of the present invention, the decompression source comprises a vacuum pump, for example.

According to still another embodiment of the vacuum suction control mechanism apparatus of the present invention, the vacuum suction control mechanism apparatus may further comprise a bonding surface plate configured to hold a bonding object, and the bonding surface plate may be provided so as to face the surface of the first member.

According to another embodiment of the vacuum suction control mechanism apparatus of the present invention, the first member and/or the bonding surface plate may comprise elasticity

Furthermore, according to another embodiment of the film bonding apparatus of the present invention, the vacuum suction control mechanism apparatus may be an apparatus for attracting and bonding an optical film.

Moreover, according to still another embodiment of the film bonding apparatus of the present invention, the bonding surface plate may comprise holding member holding the bonding object in a flat state.

Furthermore, according to another embodiment of the display apparatus of the present invention, the film may comprise flexibility.

Moreover, according to still another embodiment of the display apparatus of the present invention, the film may be an optical film, and the bonding object may be a substrate that allows visible light to pass therethrough.

Furthermore, according to another embodiment of the display apparatus of the present invention, the optical film may be a polarization film or a retardation film.

Moreover, according to still another embodiment of the display apparatus of the present invention, the film may be a protective film.

Furthermore, according to another embodiment of the display apparatus of the present invention, the bonding object may be formed of glass.

In a vacuum suction control mechanism apparatus and a film bonding method according to an embodiment of the present invention, the vacuum suction control mechanism apparatus comprises a first member comprising suction holes and a second member for connecting the suction holes to a decompression source, and the second member connects some of the suction holes, the number of which corresponds to a relative position between the first member and the second member, to the decompression source.

Accordingly, at the time of bonding of a film, attraction can sequentially be released at a portion that has been bonded. Thus, a film can accurately be bonded to a bonding object with a simple structure without deviation of the film or mixing of dust or air.

Furthermore, since a display apparatus according to an embodiment of the present invention is manufactured by using a film bonding method according to an embodiment of the present invention, the quality of the display apparatus can be improved.

This application claims the benefit of priority from Japanese patent application No. 2007-228892, filed on Sep. 4, 2007, the disclosure of which is incorporated herein in its entirety by reference.