WO2004067267A1

WO2004067267A1 - Device for applying an adhesive film to a flat panel and associated application method

Info

Publication number: WO2004067267A1
Application number: PCT/FR2004/000128
Authority: WO
Inventors: Reinhard Georg Otto Hampel
Original assignee: Display Control
Priority date: 2003-01-22
Filing date: 2004-01-21
Publication date: 2004-08-12
Also published as: FR2850058B1; FR2850058A1

Abstract

The invention relates to a device (1) for applying an adhesive film (81) to a panel, the adhesive film initially belonging to a composite film (8) comprising said adhesive film (81) and a protective film (82). The inventive device comprises a support (2) for holding the panel and a roller (3) which is used to apply the adhesive film to the panel and which can move axially above the panel support. The invention also comprises: a mobile support (4) for the composite film, which is solidly connected to, and moves axially with, the roller; a flexible connector (5) which is equipped with first and second fixing points (6, 7), the protective film being connected to said first and second fixing points in order to form a loop around the film support with the aforementioned connector. The invention can be used easily to apply adhesive film to a panel.

Description

DEVICE FOR APPLYING AN ADHESIVE FILM ONTO A PANEL AND ASSOCIATED APPLICATION METHOD

The invention relates to flat panels having adhesive films on at least one of their faces, and in particular the devices and methods for applying such adhesive films to flat panels. The document FR-A-2 648 179 describes a machine for installing intermediate seals for multiple glazing of openings such as windows. During the manufacture of the openings, a seal is placed between the various panes, in order to fix their spacing and in order to ensure sealing between them. The assembly is then mounted in a chassis. To this end, a first pane is scrolled on an air cushion table and then lifted from the table. A second window is scrolled on the air cushion table and simultaneously provided with the seal during its scrolling. The seal is therefore unwound and cut. The second window. is held in position and then applied against the first window. The joint is initially presented in rolled up linear form. The machine implementing this method comprises a device for removing a protective film from the seal and a seal reel.

The document TW20000112786 describes a process for depositing and then removing protective layers, used during the manufacture of electronic integrated circuits.

Document WO93 / 04968 describes a printing process aimed at ensuring the continuity of the unwinding of paper when replacing the roller in use with a new roll of paper. The end of the new roller is coated with glue and then applied to a portion of the old roller driven in rotation. The new roller is then itself driven so as to ensure a continuous unwinding.

Document US Pat. No. 6,363,990 describes a device for applying a coating plaster. The coating coating is typically a coating used to mask typographical errors on documents. The application device comprises a support strip, on which a transferable coating is disposed. The device is designed to avoid reversals of the strip, which often cause breakage of the strip or non-uniform application of the plaster. The application device has a pivoting head over which passes the strip covered with plaster, the plaster being placed on the face of the strip opposite the face in contact with the head. The device comprises coils rotatably mounted relative to a housing and intended respectively for winding and unwinding the strip.

The adhesive films are generally presented, before use, as composite films comprising a protective film held on an adhesive face of the adhesive film. The methods of applying an adhesive film to a flat panel conventionally comprise a prior step of separation between the protective film and the adhesive film. This separation takes place continuously and gradually in all cases where the adhesive film can be used continuously.

In the case of the use of optical films, the film most often has an orientation determined by its manufacturing process. The polarizing films for example are generally polarized parallel or perpendicular to the direction of the unwinding. Very often, the direction of orientation of the optical film required on an optical device such as a display screen does not make it possible to apply the film continuously in an economical manner. On LCD screens, the orientation of polarizers is most often 45 ° to the edges of the screen, it it is then necessary to cut the film into formats having the required orientation, then to apply the cut formats to the substrates. Traditionally, the protective film is removed, then the adhesive film is temporarily stored and then applied to the panel.

These methods have drawbacks. The applicant has found that the rapid separation of the protective film induces the appearance of static charges on the adhesive film, which then attract the surrounding particles and dust. Temporary storage of the discovered adhesive film makes the problem even more acute.

It is also known to apply polarization adhesive films to the exterior face of glass panels used as components of liquid crystal displays.

Document US-A-5 684 557 describes a machine for applying a polarization film to a glass panel of a liquid crystal screen. The machine comprises a support table provided with suction nozzles intended to maintain the panel in position. The machine includes a panel gripper, moving a blank panel to the support table. The machine also includes a device for gripping a polarizing film, moving the film to the support table. An applicator member applies a roller to the polarizer and moves the roller over the polarization film so as to adhere the polarization film to the glass panel. The machine has actuators then lifting the panel from the table. Air projection nozzles are arranged at one end of the table, and are provided to project air under the raised panel. This projection of air eliminates most of the electrostatic charges deposited on the panel. This machine is complex and can include dust between the polarization film and the glass panel. This machine is unable to precisely position the films on successive panels of different sizes, or even incapable of positioning the films on panels not having a predetermined nominal size.

It is also frequent that the production lines for liquid crystal screens generate rejects, due to a defect in a screen polarization film. It is also frequent that the polarization film accessible to the user is scratched or deteriorated locally during its use. The deteriorated polarization film surface then loses its display functions.

A known prior art repair method included a step of separating the bias film and the glass panel. This separation step was carried out by hand and included the use of cutting tools as well as solvent sprayers. This step of the process was particularly long, tedious, polluting and resulted in a screen still showing adhesive residues and failures in the display structure. Machines for carrying out the separation operation have thus been developed.

Document WO-A-92-10922 describes a machine for automatically removing a protective film previously placed on a plate intended to form a printed circuit. A plate intended for the realization of a printed circuit is initially covered with an adhesive protective film on its two faces with a strong adhesion. The adhesion of the films to the plate poses a problem: it is necessary to peel off the films before treating the plate, but peeling regularly causes damage to the internal structure of the liquid crystal displays. The machine for automatically removing the film comprises a member automatically placing a plate in position on a surface of motorized rollers. The machine also includes a member for lifting and detaching an edge of the protective film. The machine includes another member for gradually detaching the entire protective film. The motorized rollers also evacuate the plate when the film has been removed. The member raising and detaching the edge of the film comprises a nozzle for injecting compressed air. The injection of compressed air makes it possible to reduce the adhesion of the film to initiate the detachment of the edge. The member progressively removing the film comprises a clamp intended to grip the edge of the protective film.

Document WO-A-02-41071 describes a machine for removing a polarization film from a liquid crystal screen. The machine has a table with a slot. The polarization film is peeled from the panel on one edge, then the peeled part of the film is slid into the slot when the panel is deposited on the table. A machine clamp grips the detached part of the film, then completely removes the film from the panel.

These machines have drawbacks. These machines are complex and are unsuitable or even unusable for removing a polarization film from an assembled liquid crystal screen. In addition, the surface of the panel from which the film has been removed is subject to deterioration and dust deposits. The modes of replacing the polarization film have drawbacks. Takeoff of the deteriorated polarization film presents risks of deterioration of the panel or of the electronic circuits which are generally already integral with the screen. Bonding the replacement polarization film is also tricky. It is common to include bubbles or dust between the polarization film and the glass panel. The screen control circuits also interfere with the handling of the screen, both during take-off of the deteriorated polarization film, and during bonding of the replacement polarization film. In addition, the machines for applying polarization films are unsuitable for screens which already have electronic control circuits or which come from an advanced stage of the manufacturing process. In general, the machines for applying polarization films used during the manufacture of liquid crystal displays are unsuitable for carrying out an application process on a liquid crystal display to be repaired. The use of such machines for applying polarization films on successive screens of different sizes would in any case lead to a faulty application of the polarization film. They are also industrial machines designed to process series of identical parts. However, repair shops must deal with arrivals of parts of various sizes and types. A machine suitable for repair work must therefore be easily adjustable for different sizes and types of parts, the time of the operation itself being secondary.

There is therefore a need, which the invention aims to satisfy, for a device and a method solving one or more of these problems.

The application device of the invention, for applying an adhesive film initially belonging to a composite film formed from this adhesive film and from a protective film covering an adhesive face of this adhesive film, comprises:

-a support to hold the panel, and , a roller for applying the adhesive film to the panel held on the support, the roller being axially movable above the panel support, and further comprises: 5 -a movable support for composite film, integral with the roller in its displacements axial; a flexible link provided with a first and a second fixing points, the protective film being connected to the first and 0 second fixing points to form with the link a loop around the film support. Alternatively, the film support has a flat film receiving surface, the surface having an inclination of between 5 ° and 45 ° relative to the panel support.

According to another variant, the panel support has a substantially rectangular panel receiving surface, and in that a recess capable of receiving a

, control circuit of a liquid crystal display is 0 formed along an edge of the receiving surface.

According to yet another variant, the device comprises several interchangeable panel supports.

According to yet another variant, the panel support has a panel receiving surface and 5 conduits opening onto the receiving surface;

the device also has a suction member connected to the conduits and capable of holding a panel in position on the panel support. 0 It can also be provided that the device further comprises:

an axial panel stop disposed at an axial end of the panel support; an axial stop of adhesive film, disposed on the axial stop of the panel, and projecting in direction of the panel support relative to the axial panel stop.

Alternatively, the axial stop of the adhesive film has a thickness less than or equal to the thickness of the adhesive film to be applied.

According to another variant, the roller and the film support are driven in axial translation by a geared motor.

According to yet another variant, the distance between the roller and one end of the film support is less than 100 mm and preferably as small as possible.

The invention also relates to a method of applying along an axis on a flat panel, such as a glass panel, an adhesive film initially belonging to a composite film formed from this adhesive film and a protective film. covering an adhesive face of this adhesive film, comprising the steps of:

forming a loop around a support for the composite film by connecting the ends of the protective film to the fixing points of a flexible link;

separation of the adhesive film and the protective film on one edge of the composite film; -application of the edge of the separate adhesive film on the panel;

- identical axial displacement of the composite film support and of the application area of the rest of the adhesive film. According to a variant, the glass panel belongs to a liquid crystal screen, the adhesive film is a polarization film, and the method further comprises a step of peeling off an old polarization film from the panel before the step of application. According to another variant, the method further comprises a step of maintaining a circuit for controlling the the liquid crystal display in a recess during the application of the polarization film.

According to yet another variant, the method further comprises a step of placing the composite film with an inclination of between 5 ° and 45 ° relative to the panel, before the application step.

According to yet another variant, the method further comprises the step of axially holding the panel, and the separate adhesive edge is brought into axial abutment against the panel so as not to subsequently apply the adhesive film to a part of the panel delimited by the abutment area.

Furthermore, it is also expected that the distance between the area of application of the adhesive film and the separation area remains less than 100 mm.

The invention will be better understood on reading the description which follows and on examining the figures which accompany it. The figures show:

-Figure 1, a schematic side view of an adhesive film application device according to the invention, in a rest position;

-Figure 2, a side view of the device of Figure 1 after the formation of a loop around a composite film support; -Figure 3, a side view of the device of Figures 1 and 2 after placing a panel on a panel support;

FIG. 4, a side view on a larger scale of a stop zone of the device in the configuration of FIG. 3;

FIG. 5, a side view of the device in an initial position for applying the adhesive film to the support;

-Figure 6, a side view on a larger scale of the initial application area of the adhesive film; FIG. 7, a front view of a portion of the device during the application of the roll on the adhesive film, in the particular case of the application of an adhesive film on a liquid crystal screen; -Figure 8, a side view in section of a fastener connected to a composite film and attached to a flexible link.

The invention provides a device for applying, on a flat panel, an adhesive film belonging to a composite film formed from this film and a protective film covering an adhesive face of this adhesive film. This device has a loop formed around a support for the composite film. The loop is formed by a flexible link provided with first and second fixing means and by the protective film connected to the fixing points.

Figure 1 shows a schematic side view of an adhesive film application device 1, in the absence of a composite film comprising the adhesive film to be applied, and in a rest position. The adhesive film application device 1 comprises a panel holding support 2, mounted for example on a frame or table 21 by any suitable means. The panel holding support 2 thus serves to ensure the positioning and the holding in position of a panel having at least one flat surface on which the adhesive film is to be applied.

The adhesive film application device 1 further comprises an adhesive film application roller 3. The roller 3 is provided for applying a force to the adhesive film, so that the adhesive face of the adhesive film is applied against a panel maintained on the support 2. The roller 3 is axially movable above the support 2. The axis of mobility corresponds to the direction of application of the adhesive film, generally perpendicular to the largest dimension of the roller. We preferably uses a roller 3 also movable in rotation about an axis parallel to an application line on an adhesive film. The roller 3 can therefore be mounted for rotation on a gantry 31, movable in translation along the axis of application relative to the panel support 2.

The adhesive film application device 1 further comprises a movable composite film support 4. The composite film support is provided to support the composite film, for example by means of a flat film receiving surface 41 on which the composite film can be deposited. The composite film support is movable in axial translation in order to allow adequate movement of the composite film during the application of the adhesive film. The support is integral with the roller in its translations along the axis of application. It is thus guaranteed, as will be described later, that the distance between the area of the adhesive film applied and the area of separation between the adhesive film and the protective film remains substantially constant. This limits the exposed part of the adhesive film when the film is applied to the panel. This reduces the risk of including impurities or bubbles between the panel and the adhesive film. Figure 2 illustrates the device of Figure 1 after the establishment of a composite film 8. The device then comprises a flexible link 5 provided with a first 6 and a second 7 attachment points. A flexible link 5 is used, so as to allow the displacement of the loop formed around the composite film support 4. The protective film 82 of the composite film 8 is connected to the first and second fixing points 6 and 7 to form a loop around the film holder with this protective film. The loop formed makes it possible to obtain a separation between the adhesive film and the protective film, simultaneously with the application of the adhesive film. on the panel. It is thus possible to keep the length of adhesive film discovered substantially constant. We can consider that it is equivalent to connect the rear end of the protective film or the rear end of the adhesive film to the fixing point 7, since the respective rear parts of these films remain integral with each other. during most of the application of the adhesive film.

The composite film support 4 preferably comprises rotary references 42 to 44 at its ends, so as to allow a regular displacement and with reduced forces of the formed loop. For example, rollers mounted at their ends on plain bearings housed in the film support 4 can be used. 5 If necessary, the film reception surface has an adjustable inclination between 5 ° and 45 ° relative to the panel support. 2. In general, the inclination of the support of the receiving surface 41 will be adjusted by the operator at an angle which makes it possible to 0 place the line of application of the adhesive film in the plane containing the receiving surface 41 and exactly under the application roller. An inclination greater than this angle is to be avoided as it causes the film to touch the substrate before the roll, which results in the inclusion of bubbles. Adjusting the angle lower than this angle can on the other hand make it possible to compensate for a certain deformation of slightly rigid films under their own weight, for the

'' prevent touching the substrate before the axis of the roller.

One can also provide for this purpose an adjustment of the height of the surface 41.

According to an advantageous variant, use is made of a support having a substantially rectangular panel receiving surface. The 1 household device

^* also a shrinkage along an edge of the receiving surface. In the example of FIG. 7, the device 1 provides in particular a recess 10 along an edge parallel to the axis of application. The recess 10 is intended to house an electronic control circuit 20 for a liquid crystal screen. These control circuits 20 conventionally have a flexible connection with a screen panel 15. The connection can thus flex to allow insertion of the circuit 20 in the recess. The removal thus makes it possible to apply an adhesive film to a screen, without requiring disassembly, then reassembly of the control circuits 20. Avoiding the disassembly of a control circuit provides time savings and a guarantee of the subsequent operation of the 'screen. During the passage of the application roller, the control circuits are thus not damaged. The withdrawal 10 can be carried out either by raising the support 2 relative to a plate of the device 1, or by a suitable lowered shape made in the support 2 itself. Of course, several edges may have recesses intended to receive control circuits.

As can be seen more clearly in FIGS. 3 and 4, the adhesive film application device 1 also preferably has a stop system 9 facilitating the relative placement of a panel 16 and an adhesive film 81. The stop system of Figure 4 is disposed on an axial end of the panel holding support 2. The system 9 comprises a first stop 12, raised relative to the panel receiving surface. The stop 12 is intended to ensure correct axial positioning of the panel 16. The stop 12 is surmounted by an adhesive film positioning stop 13. This stop 13 projects axially in the direction of the panel support relative to the stop 12. This stop therefore partially covers a panel 15 on which the adhesive film 81 is to be applied. This stop 13 allows the end of the adhesive film 81 to be set back relative to an edge of the panel 16. This is particularly advantageous, in particular when the panel 16 is a liquid crystal screen panel 15. The panel 16 shown in the figures belongs to a liquid crystal screen 15 having two glass panels 16 and 17, as well as a polarization film 18 placed on one side exterior of the panel 17. In most cases, liquid crystal screens require that an adhesive polarization film applied to a panel 16 be set back with respect to the edge of the panel 16. The panel 16 then has an area not covered by an adhesive polarization film 81 thus applied.

It is advantageous for the thickness of the stopper 12 to be at least equal to the thickness of the panel on which the adhesive film is to be applied. The stop 13 can thus overhang the panel. It is particularly advantageous that the stop 12 has the same thickness as the panel or the device provided with the panel on which the adhesive film 81 is to be applied. Thus, the stop 13 is flush with the surface of the panel 16. This avoids including bubbles at the start of the application of the adhesive film 81. It is also preferable for the stop 13 to have a thickness at most equal to the thickness adhesive film 81 to be applied. When the roller 3 is applied to the adhesive film 81, the stop 13 does not then prevent contact between the roller 3 and the adhesive film 81. It is in particular possible to provide as a stop 13 for falling films of polarization of identical thickness to the polarization adhesive film 81 to be applied to a panel 16 of liquid crystal screen 15.

The panel device or support also preferably has an adequate vacuum system to selectively hold the panel in position. It is for example possible to produce, in the panel support, conduits 14 opening onto the panel receiving surface. These conduits 14 are then connected to a pump vacuum adequate to hold a panel in position on the panel support 2. Holding the panel by such a system allows to clear the surface of the panel or screen intended for the application of the adhesive film, while ensuring a hold of the appropriate panel.

It is also possible to use a set of several removable supports 2, each having dimensions adapted to a specific panel or screen. The adhesive film application device 1 thus has a clamping device 24 making it possible to position and maintain in position the support 2 relative to the chassis 21. The removable supports 2 can thus be fixed and easily removed from the chassis 21. It is possible to then provide that the removable supports 2 also include stop systems 9 of specific dimensions. Provision may be made for the various removable supports 2 and stops 9 to have an identical axial arrangement with respect to the chassis 21. It is then preferably provided that the axial position of the start of application of the roller is also clamped. This starting position is preferably determined so that the roller is applied to the edge of the adhesive film 81 which is in contact with the stop 13. Thus, the initial line of application of the roller 3 on the adhesive film 81 always has the same axial arrangement when placing successive panels with their respective supports 2.

It is also possible to provide for the roller to be movable in translation in a direction normal to the receiving surface of the panel holding support 2. The roller 3 thus makes it possible to selectively release the part of the adhesive film 81 to be applied initially, in particular to facilitate the initial manipulations of the application process. In the example shown, provision is therefore made for the roller 3 to be movable vertically relative to the gantry 31. It can also be provided that the roller has a damped vertical mobility, in order to obtain a substantially constant application force, even when the roller is applied to uneven surfaces. This can in particular be useful at the end of the application of the adhesive film, when using a fixing of the composite film to the flexible bond as described later. Provision may also be made for the roller 3 to have an outer elastomer coating in order to increase the surface of application on the adhesive film 81. 0 Furthermore, the axial displacement of the roller and of the film support can be achieved by any suitable means . One can for example provide a drive in axial translation of the manual type or by geared motor. Provision may be made for the drive by the geared motor 5 11 to be interrupted when a movable element 22 integral in translation with the roller 3 and the film support 4 comes into contact with a stop. It can be provided that the axial position of the stop can be modified to adapt to different axial dimensions of the panels 0 16 to be placed on the support 2. In the examples shown, the gearmotor forms an axial stop for the movable element 22 .

The flexible link 5 used advantageously comprises a latching device 51 which can selectively join 5 parts of the link 5. The flexible link can

, thus be more easily manipulated during its attachment to the composite film 8. The latching device 51 may for example have fastenings for two straps of the flexible link 5. The latching device 51 may also 0 have a member for adjusting the distance between the two fixing points 6 and 7.

, The fixing points 6 and 7 may comprise a rigid part 71 provided with fixing means 75 with the flexible link 5, possibly adjustable. The fasteners 6 5 and 7 may have a flexible film 72 having an articulation 74 with the rigid part 71. The flexible film 72 preferably has a thickness less than the thickness of the composite film 8, in order to facilitate the movement of the loop around the support 4. The flexible film 72 of each attachment can then be connected to the composite film 8 by means of an adhesive tape 73. FIG. 8 schematically represents the rear part of the composite film connected to a fixing 7 of this type. The use of a flexible film 72 connected directly to the adhesive film 81 of the composite film makes it possible to maintain the adhesive film during the end of the application, when the adhesive film 81 and the protective film 82 are completely separated. The flexible film 72 can thus be deformed, then pass partially under the roller without disturbing the end of the application of the adhesive film 81 to the panel 16.

The adhesive film 81 comprises an adhesive film made for example of polymer and an adhesive layer distributed over the adhesive film. The adhesive film 81 can have any suitable structure known from the state of the art. The adhesive film 81 to be applied to the panel 16 is initially protected by a protective film 82 with lower adhesion to form a composite film 8. During the separation between the adhesive film 81 and the protective film 82 with lower adhesion, the major part of the adhesive separating the two films remains present on the adhesive film. The adhesive is intended to adhere to the panel on which it is applied in order to maintain the adhesive film 81 on the panel.

The adhesive film 81 can in particular be a polarization film, of the type conventionally used on liquid crystal display panels, or a microprismatic film. The composite film 8 sometimes includes a second protective film adhering to the other face of the adhesive film 81. This second protective film (not shown) may in particular have adequate physical and dimensional properties to stiffen the adhesive film 81. The second protective film may in particular have a rigidity greater than that of the adherent film: this facilitates handling of the assembly, in particular during application to the panel, and reduces the requirements concerning the material or the thickness adherent film.

The following description of the method for applying the adhesive film 81 also makes it possible to better understand the operation of the device for applying the adhesive film 1.

Figure 1 shows the adhesive film application device 1 in its rest position, in the absence of flexible link 5. The assembly formed by the gantry 31, the roller 3 and the composite film support 4 is offset to the right in order to provide good access to the support 2. This position makes it possible in particular to mount or dismount the support 2 of the frame 21. The roller 3 is here in the raised position, according to the possibility presented by the variant of the device described above. During a first step, the composite film 8 is put in place on the film support 4. For this, the axial ends of the protective film 82 are connected to the fixing points 6 and 7 of the flexible link 5. In the example, the fastening 6 was thus connected to the film 82, and the fastening 7 to the adhesive film 81. As the rear ends of the films 81 and 82 remain integral most of the application phase, this amounts to connecting the fastening 7 to the protective film 82. It is however preferable to connect the adhesive film 81 to the fixing 7, so as not to disturb the movement of the composite film on the support 4. The loop around the support 4 is for example formed by placing the film composite on an upper planar surface 41 of the support 4, then closing the latching device 51 under the underside of the support 4. The adhesive film application device 1 then has the configuration illustrated in FIG. 2. The use of the latching device 51 also makes it possible to connect the flexible link 5 in two stages to the composite film 8. It is thus possible to attach halves of flexible links to composite films 8 in series. The loop formed from the connected composite film 8 the link 5 can then be moved by scrolling around the support 4.

In a subsequent step, a panel 16 is placed on the support 2, as shown in FIG. 3. In the example of FIG. 3, the panel belongs to a liquid crystal screen 15. It may in particular be a liquid crystal screen 15 having a panel

16 from which a previous polarization film has been removed. The panel 16 is held in position by any suitable means. One can for example use the suction device described above to achieve an air depression at the receiving surface of the support 2 on which the screen is arranged. It is preferable to check the cleanliness of the panel 16 after its installation. FIG. 4 represents an enlargement of the zone of the stop system 9 after the positioning of the screen 15 on the support 2. The screen 15 comprises a glass panel 16 on which an adhesive polarization film must be applied. The screen also includes a second glass panel 17 provided with a polarization film 18. The screen 15 rests on the support 2 by means of the polarization film 18. An axial edge of the panels 16 and

17 is in abutment against the stop 12, so as to ensure their precise positioning. The stop 13 is put in place. The stop 13 overhangs the panels 16 and 17 and is flush with the panel 16.

In the event that the assembly formed by the roller 3 and the support 4 has previously been removed from the support 2, this assembly is brought closer to the edge of the panel 16 on which it is desired to initiate the application.

There is in particular the roller 3 above the area initial application. In the case where the initial positioning of the assembly is automated with a motorized drive, an axial stop can be adjusted to interrupt the drive of the assembly to this initial position. In the example illustrated, the position of an axial switch 23 is adjusted, on which the gantry abuts to interrupt the reconciliation drive.

In another step of the process, preferably after having brought the whole of the initial application area closer together, the separation of the front end of the composite film 8 is initiated. The front edges of the adhesive film 81 and the protective film 82 are thus separated. The loop is made to run on the support 4. The front edge of the adhesive film 81 is thus brought closer to its initial area of application on the panel 16. Simultaneously with the bringing together, the rear end of the composite film 8 is moved and the link 5 thus drives the part of the protective film 82 removed under the support 4.

The front edge of the adhesive film 81 is brought into contact with the panel 16, as illustrated in FIGS. 5 and 6. The front edge of the adhesive film 81 is for example brought into contact with the stop 13 in order to ensure its adequate positioning with respect to the panel 16. As can be seen more precisely in FIG. 6, only the portion of the adhesive film 81 situated between the end of the support 4 and the area of application with the panel 16 is uncovered. The risk of inclusion of dust is thus limited.

The roller 3 is then brought into contact with the adhesive film 81, in order to exert a force for applying the adhesive film 81 to the panel 16. Consequently, the roller will also maintain the part of the adhesive film applied in position on the panel 16. This position of the roller is better illustrated in FIG. 7. FIG. 7 also shows the placement of a control circuit 20 of the screen 15 in a recess 10 described previously. The assembly comprising the roller 3 and the support 4 is then axially translated, in order to continue the application of the adhesive film 81 to the panel 16. The applied portion of the adhesive film 81 is held in place on the panel 16 by the roller 3 , the support 4 drives the composite film in translation. The displacement of the assembly thus results simultaneously in the application of the adhesive film, in the gradual separation between the adhesive film 81 and the protective film 82, as well as in the progressive entrainment of the protective film 82 separated along the loop . During the axial translation of the assembly, due to the loop formed, the speed of the area of application of the adhesive film 81 is substantially identical to the speed of separation of the composite film 8. The exposed area of the adhesive film therefore remains substantially constant. The process is therefore carried out with a relatively simple structure, while limiting the area of the adhesive film 81 capable of receiving dust to a substantially constant area.

The translation of the assembly during the application of the adhesive film is preferably carried out with an axial speed of less than 50 mm / s, in order to guarantee good application conditions. If necessary, the motorized assembly reaches its stop position, and the drive in axial translation is interrupted. The roller 3 can then be raised, then the panel or the element comprising the panel can be removed from the support 2. The method and the device according to the invention can be used both for repairing liquid crystal screens on a manufacturing line for repairing used liquid crystal displays. They can also be used for adhesive films such as microprism films.

Claims

1. Application device (1), on a flat panel (16), such as a glass panel, with an adhesive film

(81) initially belonging to a composite film (8) formed from this adhesive film (81) and from a protective film (82) covering an adhesive face of this adhesive film, this device comprising: a support (2) for maintain the panel, and

a roller (3) for applying the adhesive film to the panel held on the support, the roller being axially movable above the panel support, characterized in that it further comprises: -a movable support (4) of composite film, integral with the roller in its axial displacements;

-a flexible link (5) provided with first and second attachment points (6,7), the protective film being connected to the first and second attachment points to form a loop around the support with the link of movie.

2. Application device according to claim 1, characterized in that the film support has a flat film receiving surface (41), the surface having an inclination between 5 ° and 45 ° relative to the panel support.

3. Application device according to claim 1 or 2, characterized in that the panel support has a panel receiving surface (2) substantially rectangular, and in that a recess (10) capable of receiving a circuit screen control liquid crystal is formed along an edge of the receiving surface.

4. Device according to any one of the preceding claims, characterized in that it comprises several interchangeable panel supports.

5. Device according to any one of the preceding claims, characterized in that: the panel support (2) has a panel receiving surface and conduits (14) opening onto the receiving surface;

the device also has a suction member connected to the conduits and capable of holding a panel in position on the panel support.

6. Device according to any one of the preceding claims, characterized in that it further comprises:

an axial panel stop (9) disposed at an axial end of the panel support; an axial stop of adhesive film (13), disposed on the axial stop of the panel, and projecting in the direction of the panel support with respect to the axial stop of the panel.

7. Device according to claim 6, characterized in that the axial stop of the adhesive film has a thickness less than or equal to the thickness of the adhesive film to be applied.

8. Device according to any one of the preceding claims, characterized in that the roller and the film support are driven in axial translation by a geared motor (11).

9. Device according to any one of the preceding claims, characterized in that the distance between the roller (3) and one end of the film support is less than 100 mm and preferably as small as possible.

10. A method of applying along an axis on a flat panel, such as a glass panel, an adhesive film (81) initially belonging to a composite film (8) formed of this adhesive film and a film of protection covering an adhesive face of this adhesive film, comprising the steps of:

forming a loop around a support for the composite film (4) by connecting the ends of the protective film to fixing points (6,7) of a flexible link (5);

- identical axial displacement of the composite film support and of the application area of the rest of the adhesive film.

11. The method of claim 10, characterized in that the glass panel belongs to a liquid crystal screen, in that the adhesive film is a polarization film, and in that the method further comprises a step of peeling off. '' an old polarization film of the panel before the application step.

12. The method of claim 11, characterized in that it further comprises a step of maintaining a control circuit of the liquid crystal screen in a shrinkage during the application of the polarization film.

13. Method according to any one of claims 10 to 12, characterized in that it further comprises a step of placing the composite film with an inclination between 5 ° and 45 ° relative to the panel, before step d 'application.

14. Method according to any one of claims 10 to 13, characterized in that it further comprises the step of axially holding the panel, and in that the separate adhesive edge is brought into axial abutment against the panel so not to apply the adhesive film subsequently to a part of the panel delimited by the abutment zone.

15. Method according to any one of claims 10 to 14, characterized in that the distance between the area of application of the adhesive film and the separation area remains less than 100mm.