JP2009056735A - Optical film laminated body, its manufacturing method, and back light unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical film laminated body wherein handling of the optical film is facilitated, the number of the processes needed for assembling of the back light is reduced, possibility of damaging the optical film is reduced, and the yield is increased, and the manufacturing method of the optical film laminated body and a back light unit using the optical film laminated body. <P>SOLUTION: In the optical film laminated body including first and second optical films, and at least one sandwiched optical film sandwiched between the first and second optical films, the first and second optical films are joined via connection members disposed at least at two places of both sides of the outer circumference of the optical film laminated body, having the same thickness as the sandwiched optical film and not connected to the sandwiched optical film. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical film laminate in which a plurality of optical films are laminated, a method for producing the laminate, and a backlight unit using the optical film laminate.

  Liquid crystal displays (LCDs) are used in mobile phones, notebook computers, LCD monitors, liquid crystal televisions, and the like. A transmissive LCD requires a backlight, and an optical film for adjusting the backlight is incorporated in the backlight unit in order to improve display performance. Various types of optical films, such as prismatic structured films and diffusion films, are used to improve output brightness, illumination uniformity, and viewing angle.

  FIG. 5 is a perspective view showing a conventional liquid crystal display device 100. The liquid crystal display device 100 is provided with a backlight unit 150 on the back side of a transmissive liquid crystal panel 151. The backlight unit 150 includes a light source 152, a light guide plate 153, a reflection plate 154, and the optical film 110. The light source 152 is realized by, for example, a light emitting diode (LED). The backlight unit 150 is an edge light type illumination device, and a light source 152 is provided on one side surface portion of the light guide plate 153, a reflection plate 154 is provided on one main surface portion of the light guide plate 153, and the other main portion of the light guide plate 153 is provided. An optical film 110 is provided on the surface portion. The optical film 110 is configured by laminating a plurality of films 111a to 111d.

  In this optical film 110, illumination light emitted from the light source 152 is incident on the light guide plate 153 from one side surface, is emitted from the other main surface of the light guide plate 153, and is irradiated on the liquid crystal panel 151 through the optical film 110. . The optical film 110 diffuses and collects illumination light emitted from the other main surface of the light guide plate 153 so that it can be illuminated uniformly over the entire liquid crystal panel 151. It is configured to demonstrate.

  The optical films 110 are laminated one by one between the light guide plate 153 and the liquid crystal display panel 151, and there are some problems in handling and assembling several individual film pieces during manufacturing. Individual optical films are easily scratched and have a protective cover, which needs to be removed during assembly, which is time consuming and can damage the film when the protective cover is removed. Furthermore, since a plurality of films are laminated one by one, it takes more time, and there are more opportunities for dust to enter between the films or damage to the films, leading to a decrease in throughput and a decrease in yield.

  As a method for solving this, a laminate (for example, Patent Document 1) of a light control film in which at least two films are bonded at a zero gap joint provided outside the display region, and a plurality of optical sheets are laminated, An optical sheet (for example, Patent Document 2) that joins only the uppermost optical sheet and the lowermost optical sheet has been proposed.

JP-T-2006-513352 JP 2007-155940 A

  However, in the former document, there is one joint or two joints on the same side, and the unbonded portion of the film easily opens, and dust enters between the films. Or the film surface may be exposed and the film surface may be damaged. Therefore, the suction by the suction pad is also the suction of only the uppermost film, and there is a problem that the suction pad cannot be used. In addition, since there is a difference in the amount of expansion due to heat and humidity in the film to be laminated, when joining at multiple points, if there is a change in heat or humidity, a difference in expansion occurs between the films, wrinkles occur in the film laminate, etc. There is a problem in the optical characteristics. Further, there is no connection member between the uppermost optical sheet and the lowermost optical sheet of the optical sheet disclosed in the latter document, and there is a space between the uppermost and lowermost optical sheets at the joint. Yes, if it is joined, the distance between the uppermost and lowermost optical sheets will be reduced, so the sheet sandwiched between the uppermost and lowermost optical sheets near the joint will be distorted and warped. , Wrinkles, etc., resulting in problems in optical properties, and a sheet sandwiched between the uppermost and lowermost optical sheets is separately punched and inserted between the uppermost and lowermost optical sheets. There is a problem that garbage enters during the insertion work. Further, there is a problem that the manufacturing apparatus becomes complicated.

  In view of the above problems, an object of the present invention is to facilitate the handling of an optical film, reduce the chance of damaging the optical film, reduce the number of steps required for the assembly of the backlight, and improve the yield. And a manufacturing method thereof, and a backlight unit using the optical film laminate.

The present invention relates to an optical film laminate including a first optical film, a second optical film, and at least one sandwiched optical film sandwiched between the first and second optical films.
The first and the second are arranged via connecting members that are arranged at least on both sides of the outer periphery of the optical film laminate, have the same thickness as the sandwiched optical film, and are not coupled to the sandwiched optical film. An optical film laminate, wherein an optical film is bonded. Here, both sides refer to the outer periphery on the opposite side of the film, and include the substantially opposite side where the gap between the films does not open easily and the suction pad can be used.

  The optical film laminate of the present invention is characterized in that the first and second optical films are made of the same material.

  Furthermore, the optical film laminate of the present invention is characterized in that the joining member is formed of the same material as the sandwiched optical film.

  Furthermore, the optical film laminate of the present invention is characterized in that the first and second optical films and the connecting member are each joined with zero gap.

  Furthermore, the optical film laminate of the present invention is characterized in that the first and second optical films and the sandwiched optical film are substantially rectangular and the outer periphery thereof is aligned.

  Furthermore, the optical film laminate of the present invention is characterized in that the joining is joining by ultrasonic welding.

  Furthermore, in the optical film laminate of the present invention, the first and second optical films are diffusion films, and the sandwiched optical film includes a prismatic photo-alignment film.

  Furthermore, the optical film laminate of the present invention is characterized in that it has at least one joint portion of the first and second optical films on each side outside each side of the outer periphery of the optical film.

  Further, another one of the present invention is a notch for making a cut at a predetermined position by superposing the original film supplying process for supplying each original film of the optical film laminate and the original film of the sandwiched optical film. A predetermined position is joined by superimposing the film original fabric of the first optical film from one side and the film original fabric of the second optical film from the other on the film original fabric that has passed through the step and the cutting step And a punching step of punching out an optical film laminate having a predetermined shape from the laminated film original that has passed through the joining step.

  In the production method of the present invention, in the raw material supply step, the belt-shaped film raw material is wound in a roll shape over the entire length in the longitudinal direction, and is fed out from the roll and supplied, and at least one film raw material is another film. It supplies in the direction orthogonal to the original fabric.

  Further, in the manufacturing method of the present invention, at least one of the cutting step or the punching step includes a step of punching the overlapped film with any press selected from a Thomson type, a pinnacle type, and an engraving blade. And

  Furthermore, the manufacturing method of the present invention is characterized in that the joining step performs joining by ultrasonic welding.

  Furthermore, in the manufacturing method of the present invention, the first and second optical films are diffusion films, the prismatic film having prism-shaped ribs in the first direction on the sandwiched optical film, and the first direction And a prismatic film having prismatic ribs in a second direction that are non-parallel.

  Another aspect of the present invention is an optical film laminate, one or more light sources that illuminate a light guide panel, and light incident from the one or more light sources is transmitted through one surface and optically transmitted. A light guide plate directed to the film laminate, wherein the optical film laminate is sandwiched between the first optical film, the second optical film, and the first and second optical films. In a laminate composed of a single sandwiched optical film, a connection that is disposed at least at two positions on both sides of the outer periphery of the laminate and has substantially the same thickness as the sandwiched optical film and is not coupled to the sandwiched optical film The backlight unit is characterized in that the first and second optical films are bonded via a member.

  According to the optical film laminate of the present invention, in the optical film laminate including the first and second optical films and at least one sandwiched optical film, at least two locations on both sides of the outer periphery of the optical film laminate Therefore, the possibility that the optical film is not easily opened and that dust enters between the optical films or the surface of the optical film is exposed and the surface of the optical film is damaged is reduced. Since at least two places on both sides are joined, the suction pad does not suck only the uppermost optical film, and there is no problem that the suction pad cannot be used. If at least two places on both sides are not joined, the suction pad cannot be used. In addition, since the first and second optical films are joined via a connecting member that is not coupled to the sandwiched optical film, the optical films to be laminated have a difference in expansion due to heat and humidity. Even when bonded at a point, since the sandwiched optical film is not bonded to the first and second optical films, the difference in expansion is irrelevant and wrinkles occur in the optical film laminate. The problem disappears. Furthermore, since it joins via the connection member of the same thickness as a to-be-clamped optical film, an optical film laminated body does not produce distortion, but optical quality also becomes favorable. Note that the same thickness includes those having substantially the same thickness. As a result, it can be handled reliably without being disassembled during handling, the handling of the optical film becomes easy, the chances of damaging the optical film can be reduced, and it has conventionally been handled individually as a plurality of optical films. What has been used can be handled as a single component as an optical film laminate, which is easy to handle, reduces the number of steps required for assembling the backlight, and improves the yield.

  According to the present invention, since the first and second optical films are formed of the same material, the amount of expansion is the same even when the heat and humidity are changed, and the first and second optical films are bonded to the sandwiched optical film. Therefore, even if there is a difference in expansion between them, wrinkles and the like are not generated, and the change in optical characteristics can be eliminated.

  Furthermore, according to the present invention, since the joining portion of the first and second optical films is formed of the same material as the sandwiched optical film, the connection member can be formed only by cutting, and the processing is facilitated. The difference of the total thickness of the optical film laminated body which is the junction part of a 1st and 2nd optical film, and a non-joining part can be made small. As a result, the distortion of the laminate can be eliminated, and the optical properties of the laminate are excellent.

  Furthermore, according to the present invention, the first and second optical films and the connection member are zero-gap bonded, so that the change in the thickness of the non-bonded portion and the bonded portion can be reduced. As a result, the distortion of the laminate can be eliminated, and the optical properties of the optical film laminate are excellent.

  Furthermore, according to the present invention, the first and second optical films and the sandwiched optical film are each aligned with a substantially rectangular outer periphery so that the outer periphery of the optical film laminate can be easily handled with the case of the backlight unit. Can be used for fitting.

  Further, according to the present invention, since the bonded portion of the optical film is bonded by ultrasonic welding, bonding can be performed without using an adhesive or the like, and the change in the thickness of the bonded portion and the non-bonded portion can be reduced. it can. As a result, the distortion of the optical film laminate can be eliminated, and the optical properties of the optical film laminate are excellent.

  Furthermore, according to the present invention, since the first and second optical films are diffusion films, and a prismatic photo-alignment film is sandwiched between the first and second sandwiched optical films, a laminate can be formed. A backlight unit that can uniformly illuminate the entire illumination area by diffusing and condensing light from the light source can be obtained.

  Furthermore, according to the present invention, since the first and second optical film have at least one joint on each side outside the outer peripheral sides of the optical film, the number of joints increases and the distance between the optical films increases. However, the possibility that dust may enter between the optical films or the optical film surface is exposed and the optical film surface is damaged is reduced.

  In addition, according to the method for producing an optical film laminate of the present invention, since the raw film supply process, the cutting process, the joining process, and the punching process of each film original are included, the first and second optical films Therefore, it is possible to manufacture an optical film laminate with a sandwiched optical film structure, which can be handled as a single part as an optical film laminate, easy to handle, and reduce the number of processes required for backlight assembly. In addition, the yield can be improved. Further, there is no step of separately punching the sandwiched optical film and inserting it between the first and second optical films, and there is no problem that dust enters between the films during the step. In the present invention, the original fabric includes materials.

  Further, according to the manufacturing method of the present invention, the raw film supply step rolls the belt-shaped film raw material in a roll shape over the entire length in the longitudinal direction, feeds it from the roll and supplies it, and at least one film raw material is supplied. Since the film is fed in the direction perpendicular to the other film originals, each film original can be supplied smoothly and at a high speed, and the film can be handled in an orthogonal direction easily. The production efficiency of the body can be improved.

  Furthermore, according to the optical film manufacturing method of the present invention, since at least one of the cutting step or the punching step includes a step of punching with a press selected from a Thomson die, a pinnacle die, and an engraving blade, the optical film laminate The production efficiency can be improved.

  Furthermore, according to the method for producing an optical film of the present invention, since the joining step performs joining by ultrasonic welding, the joining can be easily performed in a short time, so that the production efficiency of the optical film laminate can be improved.

  Moreover, according to the optical film manufacturing method of this invention, the optical film laminated body which consists of two types of prismatic films from which orientation differs, and the diffusion film of the both sides can be obtained.

  In addition, according to the backlight unit of the present invention, it is possible to improve the quality of the backlight unit and reduce the number of assembling steps by using a backlight unit incorporating an optical film laminate including a plurality of optical films as one component. realizable.

  Further, the present invention can be applied to a backlight unit for liquid crystal displays, and is particularly useful for reducing the number of steps necessary for manufacturing such a backlight unit.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1A is a perspective view showing an optical film laminate 10 according to an embodiment of the present invention, FIG. 1B is a cross-sectional view taken along the cutting plane line S1-S1 in FIG. 1A, and FIG. It is a disassembled perspective view.

  In the present embodiment, the optical film laminate 10 includes four optical films 11a to 11d, and these optical films 11a to 11d are laminated. Hereinafter, when the optical films 11a to 11d are individually identified and described, they are referred to as a first film 11a, a sandwiched first film 11b, a sandwiched second film 11c, and a second film 11d, respectively. When any of them is described, the suffixes a to d are omitted and the optical film 11 is referred to. The optical film laminated body 10 is laminated | stacked in order of the 1st film 11a, the clamped 1st film 11b, the clamped 2nd film 11c, and the 2nd film 11d from the laminated | stacked upper side of FIG.

  The optical film laminate 10 is obtained by laminating optical films 11 to be incorporated into a backlight. Each optical film 11 is an optical film having an optical action, and the optical film 11 may include, for example, a diffusion film for diffusing light and a prism film for condensing light. In the present embodiment, the first film 11a and the second film 11d are diffusion films, and the sandwiched first film 11b and the sandwiched second film 11c are prism films.

  In the present invention, the shape of the optical film laminate is not particularly limited, but is preferably substantially rectangular, and more preferably rectangular. If it is substantially rectangular, the outer periphery of each rectangle is easily aligned, and handling is accordingly performed, and the outer periphery of the optical film laminate can be easily used for fitting with the case of the backlight unit. In the present invention, a substantially rectangular shape includes a rectangular shape. However, a simple rectangular shape includes even a rectangular shape.

  In the present embodiment, the optical film laminate has a substantially rectangular shape, and is a tab formed of the same material in which the film is extended with the same thickness as a joining member at each central part of the four sides on both sides of the outer periphery. Is provided. That is, the 1st film 11a and the 2nd film 11d are the same shape, the shape perpendicular | vertical to the thickness direction is substantially rectangular shape, and the tab parts 10a and 10d are provided in the center part of four sides. The sandwiched first film 11b and the sandwiched second film 11c have substantially the same shape, but the tab portions 10a and 10d are separated from the film body by the cutting portion 10f. The separated part is a connecting member that is not coupled to the sandwiched optical film, and is formed of the same material, and can be easily formed by only the cutout described later.

  Since there is a difference in the amount of expansion due to heat and humidity in the film to be laminated, when joining at multiple points, if there is a change in heat or humidity, a difference in expansion will occur between the films, and the film laminate will be wrinkled. Although there is a problem in characteristics, since the tab portions 10a and 10d are separated from the film main body by the cutting portion 10f, the first film 11b and the second film 11d to be sandwiched are the first film 11b and the second film 11c to be sandwiched. The above-mentioned problem can be solved without being affected by the expansion.

  The tab portions 10a and 10d of each optical film 11 are all overlapped and joined. The bonding structure of the tab portion is not particularly limited, and may be a bonding structure that is bonded using a bonding agent or may be a bonding structure that is welded. is there. If it is welding joining, it will become zero gap joining, and the change of the thickness of a junction part and a non-joining part can be decreased.

  In the configuration shown in FIG. 1, ultrasonic welding is performed. In this way, the four tab portions are overlapped and joined, and the first film 11a and the second film 11d are connected. The sandwiched first film 11b and the sandwiched second film 11c are sandwiched between the first film 11a and the second film 11d, but are not joined, and are only restrained by the tab portion at the center of each side. It is.

  The tab can also function as an alignment element when the optical film laminate 10 is incorporated into the backlight unit.

  As described above, the first film 11a and the second film 11d are connected at the center of each side so as to wrap the sandwiched first film 11b and the sandwiched second film 11c, and the surface of the first film 11a is connected. By vacuum suction, the optical film laminate 10 can be handled. In addition, although the four films are welded, the first film 11a and the second film 11d are the same diffusion film, and therefore have the same expansion coefficient due to heat or humidity. Further, the first film 11a, the second film 11d and the sandwiched first film 11b, the sandwiched second film 11c have different expansion coefficients due to heat or humidity, but the sandwiched first film 11b and the sandwiched first film 11b are sandwiched. The second film 11c is only sandwiched between the first film 11a and the second film 11d, and even if there is an expansion difference, wrinkles and the like do not occur, and the optical characteristics of the optical film laminate 10 do not change. As described above, since the first and second optical films are made of the same material, the amount of expansion is the same even when the heat and humidity are changed, and the optical film is not bonded to the sandwiched optical film. Even if there is a difference in expansion between them, wrinkles and the like do not occur, and the change in optical characteristics can be eliminated.

  FIG. 2 is an exploded perspective view showing the backlight 30 including the optical film laminate 10. The optical film laminate 10 is used as an optical component that constitutes the backlight 30. The backlight 30 is an illumination device incorporated in a liquid crystal display device or the like, and is provided on the back side of the liquid crystal display panel 26 in the transmissive liquid crystal display device, and illuminates the liquid crystal display panel 26 from the back side. The backlight 30 accommodates a light source realized by a light emitting diode (LED) 23, an FPC 24 having an LED and wiring for supplying power, a light guide plate 21, a reflection plate 22, the optical film laminate 10, and these parts. The frame 20 and the RIM sheet 25 for fixing the optical film laminate 10 to the frame 20 and fixing the liquid crystal display panel 26 to the backlight 30 are provided.

  The backlight 30 is an edge light type illumination device. The LED 23 is provided on one side surface of the light guide plate 21, the reflection plate 22 is provided on one main surface portion of the light guide plate 21, and the other main surface portion of the light guide plate 21 is provided. An optical film laminate 10 is provided. The optical film laminate 10 is provided with the second film body 11 d facing the light guide plate 21.

  Such a backlight 30 is used such that the first film body 11 a of the optical film laminate 10 is opposed to the liquid crystal display panel 26. In the backlight 30, illumination light emitted from the LED 23 is incident on the light guide plate 21 from one side surface, is emitted from the other main surface of the light guide plate 21, and is irradiated to the liquid crystal display panel 26 through the optical film laminate 10. Is done. The optical film laminate 10 diffuses and condenses illumination light emitted from the other main surface of the light guide plate 21 so that it can be illuminated uniformly over the entire liquid crystal display panel 26. It is configured to exhibit optical performance.

  In the present embodiment, the first film 11a and the second film 11d have a four-layer structure of a diffusion film, and the sandwiched first film 11b and the sandwiched second film 11c are prism films. A reflective polarizer layer may be included as the three films. This layer is useful for reusing backlight light in a polarization state inappropriate for transmitting the liquid crystal display panel 26 as image light. Depending on the actual system design, some of the elements represented by the optical film 11 may be omitted, added, or replaced with other functional elements.

  A backlight unit incorporating the optical film laminate 10 of the present invention has several advantages. Many of the optical films are very thin. For example, each prismatic structured film has a thickness of about 62 μm. The optical film used in the backlight is usually very flexible, which causes problems during the assembly of the backlight unit. The optical film laminate 10 of the present invention is a rigid optical film laminate in which a plurality of thin flexible films are bundled, and this can alleviate assembly problems. In addition, when assembling a backlight unit, multiple optical films were stacked one after another. By reducing this to one time, the possibility of introducing defects and the final yield loss were minimized. It is done. Furthermore, the optical film is usually delivered from the manufacturer to a backlight assembler with protective sheets on both sides, and the protective sheet is peeled off during assembly. The optical film laminate 10 reduces the number of protective sheets that the backlight assembler must remove. As a result, the yield and manufacturing unit cost can be further optimized.

  Next, a process of manufacturing the optical film laminate 10 and a manufacturing apparatus thereof will be described with reference to FIGS.

  FIG. 3 is an explanatory view showing a process for manufacturing the optical film laminate 10. The process proceeds in the direction of the arrow in the figure.

  First, as shown to Fig.3 (a), the film original fabric 35b of the to-be-clamped 1st film and the film original fabric 35c of the to-be-clamped 2nd film are piled up. Although not shown, it is preferable to ultrasonically weld the overlapped film originals so that their positions do not shift. Here, in order to show the manufacturing process in this figure, the film original is drawn as a rectangular sheet for convenience. However, a long strip-shaped material wound around a roll is usually drawn out from the roll.

  Next, as shown in FIG.3 (b), it cuts into a predetermined position with respect to the laminated | stacked film originals 35b and 31c. The cut portion 31 can be cut with a punching device or the like, but can be preferably formed by pressing the material with any press selected from, for example, a Thomson type, a pinnacle type, and an engraving blade.

  And as shown in FIG.3 (c), the film original fabric 35a of the 1st film is overlap | superposed with respect to the film original fabric cut | incised from the upper part, and the film original fabric 35d of the 2nd film is overlapped from the downward direction.

  And as shown in FIG.3 (d), the predetermined position 32 of the laminated | stacked film original fabric is ultrasonically welded. The portion 32 to be ultrasonically welded is located outside the location where the cut 31 was made in the previous process, and is the position that becomes the tab portion of the product when punched in the next process. The conditions for ultrasonic welding are set so that all of the superposed film originals 35 are welded.

  Finally, as shown in FIG. 3 (e), a desired shape 33 is punched into a desired shape 33 with a press selected from a Thomson type, a pinnacle type and an engraving blade, and an optical film is laminated from the original film 35. The optical film laminate 10 shown in FIG. 3 (f) can be obtained by removing the remaining portion (hereinafter referred to as “extracted residue”) 34 left after cutting the body 10.

  Through these steps, the uppermost first film and the lowermost second film are joined, and the sandwiched first film and the sandwiched second film are sandwiched between the films, and the sandwiched second film The structure which controls the outer peripheral position of 1 film and the 2nd film to be clamped is realizable.

  In this embodiment, an example of a configuration of four optical films is shown. Furthermore, when adding an optical film, what is necessary is just to add the film raw material overlapped in Fig.3 (a).

  FIG. 4 is a side view showing the manufacturing apparatus 50 for the optical film laminate 10. The process demonstrated in FIG. 3 is implement | achieved.

  The same number of film original fabrics 61a to 61d as the film body 11 of the optical film laminate 10 to be manufactured are provided. Hereinafter, when each film original fabric 61a-61d is identified and explained individually, the first film original fabric 61a, the second film original fabric 61b, the third film original fabric 61c, and the fourth film original fabric 61d, respectively. Okay, when explaining unspecified one, the subscripts a to d are omitted, and the original film 61 is called. The first film original 61a is the first film, the second film original 61b is the first film to be sandwiched, the third film original 61c is the second film to be sandwiched, and the fourth film original 61d is the first film. 2 is a raw material for forming a film. Each film original fabric 61 is a belt-shaped original fabric, and is prepared as an original fabric roll 62 by being wound in a roll shape.

  The manufacturing apparatus 50 includes a supply unit that supplies a film original 61 from each original roll 62, a first ultrasonic welder 51 that temporarily fixes each film original 61 supplied by the supply unit, and each film original. A second ultrasonic welder 52 for permanently fixing 61, a first cutting means 54 for cutting each original film 61, and a second cutting means 56 for finally cutting the optical film laminate 10. Prepare.

  The supply unit sandwiches the film original fabric 61 with a pair of conveyance rollers (not shown), and rotates the conveyance roller pair so that the film original fabric 61 is fed from the original fabric roll 62 and conveyed so as to move in the longitudinal direction. The 2nd film original fabric 62b is cut | disconnected by the length for the conveyance width of the other film original fabrics 62a, c, and d, and is supplied in the direction orthogonal to the other film original fabrics 62a, c, and d. Moreover, although not shown in figure, it passes through the supply part of each film original fabric 61, the dust adhering to each film original fabric 61, and each process by pinching with the adhesive roller which has adhesiveness after each process. Adhering dust can be removed.

  An ultrasonic horn is attached to the tip of the ultrasonic welding units 51 and 52, and the pressed portion of the film original fabric 61 is ultrasonically bonded by applying ultrasonic waves while the original film 61 is pressed. .

  The cutting means 54 and 56 are cutting machines that cut the film originals 61. By pressing a punching die such as a Thomson type, a pinnacle type, or an engraving blade against each film original 61, desired processing is realized on each film original 61.

  Although not shown, the optical film laminate 10 to be cut out can be easily transported by interposing a carrier tape in the lowermost layer of each original film 61, and the cutting blades of the cutting means 54 and 56 can be further conveyed. Wear can be prevented. Also, it functions as a means for carrying out the optical film laminate 10. For example, it can be wound in the form of a roll in the same manner as the original film 61 and supplied by a supply means having the same configuration, for example, it can be recovered by winding on a roll. The configuration of the carrier tape material and the like is not particularly limited, and various types including those conventionally known can be adopted.

  The punched residue 34 is wound around the residue take-up roll 55 and collected separately from the optical film laminate 10.

  In the manufacturing apparatus 50, the second film original 62b is supplied onto the third film original 61c, and the first ultrasonic welder 51 ultrasonically welds the third film original 61c and the second film original 62b. Then, the second film original fabric 62b becomes an intermediate laminated original fabric 63 fixed on the third film original fabric 61c.

  Next, the intermediate laminated original 63 is sent to the first cutting means 54, and a cut is provided at a predetermined position. The first film original fabric 62a is overlapped with the intermediate laminated original fabric 63 after the bend processing from above, and the fourth film original fabric 62d is superimposed from below to form an intermediate laminated original fabric 64.

  And the intermediate | middle laminated original fabric 64 is conveyed to the 2nd ultrasonic welder 52, and a predetermined position is ultrasonically welded. Thus, the first film original fabric 61a and the fourth film original fabric 61d are connected.

  Finally, the intermediate laminated raw fabric 64 ultrasonically welded is supplied to the second cutting means 56 and punched into a predetermined shape, whereby the optical film laminate 10 is formed.

  In addition, the alignment between processes can be implement | achieved by the positioning hole provided in each film original fabric 61, and each positioning pin, for example.

  As described above, the present invention can be applied to a backlight unit, and is considered to be particularly useful for reducing the number of steps necessary to manufacture such a backlight unit.

It is a block diagram which shows the optical film laminated body 10 of embodiment of this invention. It is a disassembled perspective view which shows a backlight unit provided with the optical film laminated body 10 of this invention. It is explanatory drawing which shows the manufacturing process of the optical film laminated body 10 of this invention. It is a side view of the manufacturing apparatus of the optical film laminated body 10 of this invention. It is a perspective view which shows the liquid crystal display device 100 of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Optical film laminated body 10a-10d Tab part 10f Cutting | disconnection part 11 Optical film 11a 1st film 11b Sandwiched 1st film 11c Sandwiched 2nd film 11d 2nd film 20 Frame 21 Light guide plate 22 Reflector 23 Light emitting diode ( LED)
24 FPC
25 RIM sheet 26 Liquid crystal display panel 30 Backlight 31 Cut portion 32 Ultrasonic welded portion 33 Desired shape 34 Dregs 35a to 35d Original film 50 Production apparatus 51 First ultrasonic welder 52 Second ultrasonic welder 54 First cutting means 56 Second cutting means 61 Film original fabric 61a First film original fabric 61b Second film original fabric 61c Third film original fabric 61d Fourth film original fabric 62 Original fabric roll

Claims (14)

In an optical film laminate including a first optical film, a second optical film, and at least one sandwiched optical film sandwiched between the first and second optical films,
The first and the second are arranged via connecting members that are arranged at least on both sides of the outer periphery of the optical film laminate, have the same thickness as the sandwiched optical film, and are not coupled to the sandwiched optical film. An optical film laminate, wherein an optical film is bonded.   The optical film laminate according to claim 1, wherein the first and second optical films are made of the same material.   The optical film laminate according to claim 1, wherein the joining member is formed of the same material as the sandwiched optical film.   The optical film laminate according to any one of claims 1 to 3, wherein the first and second optical films and the connecting member are each joined with zero gap.   The optical film laminate according to any one of claims 1 to 4, wherein the first and second optical films and the sandwiched optical film are substantially rectangular, and the outer periphery thereof is aligned.   The optical film laminate according to any one of claims 1 to 5, wherein the joining is joining by ultrasonic welding.   The optical film according to claim 1, wherein the first and second optical films are diffusion films, and the sandwiched optical film includes a prismatic photo-alignment film. Laminated body.   The optical film laminate according to any one of claims 2 to 7, wherein the optical film laminate has at least one joint portion of each of the first and second optical films on the outer side of each outer side of the optical film. . A raw material supply process for supplying each film raw material of the optical film laminate,
An incision step in which the original film of the sandwiched optical film is overlapped and incised at a predetermined position;
A joining step of joining a predetermined position by superimposing the original film of the first optical film from one side and the original film of the second optical film from the other on the original film that has passed through the cutting step. When,
A method for producing an optical film laminate, comprising: a punching step in which an optical film laminate having a predetermined shape is punched from the laminated film original that has passed through the joining step.   In the raw material supply step, the belt-shaped film raw material is wound in a roll shape over the entire length in the longitudinal direction, and is fed out from the roll and supplied, and at least one film raw material is orthogonal to the other film raw materials. It supplies in a direction, The manufacturing method of the optical film laminated body of Claim 9 characterized by the above-mentioned.   The at least one of the cutting step or the punching step includes a step of punching the overlapped film original with a press selected from a Thomson die, a pinnacle die, and an engraving blade. The optical film laminated body manufacturing method as described in any one of.   The method for producing an optical film laminate according to any one of claims 9 to 11, wherein the joining step performs joining by ultrasonic welding. The first and second optical films are diffusion films;
The sandwiched optical film includes a prismatic film having prism-shaped ribs in a first direction and a prism-shaped film having prism-shaped ribs in a second direction that is non-parallel to the first direction. The method for producing an optical film laminate according to any one of claims 10 to 13. An optical film laminate, one or more light sources that illuminate the light guide panel, and a light guide plate that transmits light incident from the one or more light sources through one surface toward the optical film laminate ,
In the laminate comprising the optical film laminate, the first optical film, the second optical film, and at least one sandwiched optical film sandwiched between the first and second optical films, The first and second optical films are disposed at at least two positions on both sides of the outer periphery of the laminate, and have the same thickness as the sandwiched optical film and are connected to the sandwiched optical film via a connecting member. A backlight unit characterized in that is joined.

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