Patent Application
20130313732
1. Technical Field
The present disclosure relates to an apparatus for manufacturing an optical film and a method for manufacturing the optical film using the apparatus.
2. Description of Related Art
Optical films, such as diffusion films, brightness enhancement films, or prism sheets are preferred for using in a backlight module for guiding light. An optical film usually includes a number of microstructures. The optical film with the microstructures can be manufactured through a printing method.
However, the above mentioned printing method must employ a polyethylene terephthalate (PET) film as a carrier, on which ultraviolet (UV) curable glue is adhered, and thus increasing a total thickness of the optical film. Furthermore, the light transmission of the optical film is restricted since the light transmission of the PET film is about 90%, not about 100%.
Therefore, it is desirable to provide an apparatus for manufacturing the optical film and a method for manufacturing the optical film using the apparatus, which can overcome or alleviate the above-mention problems.
Referring to
The feed hopper 10 is substantially funnel-shaped and configured for containing hot melt UV curable glue 101. The feed hopper 10 includes a mouth 12 and a pipe 14. The hot melt UV curable glue 101 flows into the feed hopper 10 through the mouth 12 and flows out the feed hopper 10 through the pipe 14.
The first pressing roller 20 and the second pressing roller 30 are positioned under the feed hopper 10. The first pressing roller 20 defines a first central axis (not labeled and which is perpendicular to the paper) in a central portion thereof and rotates about the first central axis. The second pressing roller 30 defines a second central axis (not labeled and which is perpendicular to the paper) in a central portion thereof and rotates about the second central axis. The first central axis and the second central axis are arranged on a same plane, such as a common horizontal plane, and parallel to each other. A rotating direction of the first pressing roller 22 is the reverse rotating direction of the second pressing roller 32. In this embodiment, the first pressing roller 22 rotates clockwise, and the second pressing roller 32 rotates counterclockwise.
Specifically, the first pressing roller 20 and the second pressing roller 30 are located nearby each other and spaced at a predetermined distance from each other. A molding channel 140 is formed between the first pressing roller 20 and the second pressing roller 30. The pipe 14 is aligned with the molding channel 140. That is, the longitudinal direction of the pipe 14 coincides with the molding channel 140. The hot melt UV curable glue 101 directly flows into the molding channel 140. The distance between the first pressing roller 20 and the second pressing roller 30 is substantially equal to a predetermined thickness of the optical film 200 to be manufactured.
The first pressing roller 20 and the second pressing roller 30 cooperate to press the hot melt UV curable glue 101. The first pressing roller 20 includes a first main body 22 and a first mold core 24. The first main body 22 is gear typed. In detail, the first main body 22 defines a first cavity 220 in a central portion thereof and a number of first teeth 222 on an outer circumferential surface thereof. The first mold core 24 is sleeved on and firmly adhered to the first main body 22. The first mold core 24 defines a number of first microstructures 242 on an outer circumferential surface thereof. In this embodiment, the first main body 22 is coaxial with the first mold core 24, and the axes of the first main body 22 and the first mold core 24 coincide with the first central axis.
The second pressing roller 30 includes a second main body 32 and a second mold core 34. The second main body 32 is gear typed. In detail, the second main body 32 defines a second cavity 320 in a central portion thereof and a number of second teeth 322 on an outer circumferential surface thereof. The second mold core 34 is sleeved on and firmly adhered to the second main body 32. The second mold core 34 defines a number of second microstructures 342 on an outer circumferential surface thereof. In this embodiment, the second main body 32 is coaxial with the second mold core 34, and the axes of the second main body 32 and the second mold core 34 coincide with the second central axis.
In this embodiment, the first main body 22 and the second main body 32 are made of transparent material, such as silicon dioxide (SiO2). The first molding core 24 and the second molding core 34 are made of resin of which the molecule chain including fluorine, such as ethylene tetrafluoroethylene (ETFE), or polytetrafluoroethylene (PTFE). The first microstructures 242 and the second microstructures 342 are formed by a roller pressing method. Each of the first microstructures 242 is substantially V-shaped, and each of the second microstructures 342 is substantially dot-shaped. The shape of the first microstructures 242 and the second microstructures 342 are not limited to the above mentioned shape and may be pyramid-shaped or frustum-cone-shaped. In addition, the shape of the first microstructures 242 may be the same as the shape of the second microstructures 342.
The two UV lamp assemblies 40 are received in the first cavity 220 and the second cavity 320, respectively. In detail, the two UV lamp assemblies 40 are positioned in a central portion of the first cavity 220 or the second cavity 320 and apart from the two pressing rollers 20 and 30. That is, the UV lamp assemblies 40 are still when the two pressing rollers 20 and 30 rotate.
Each UV lamp assembly 40 includes a support device 42, a UV lamp 44, and a light guide pipe 46. The support device 42 is fixed in the first cavity 220 or the second cavity 320 using an installation device. The UV lamp 44 is fixed on the support device 42 and configured for solidifying the hot melt UV curable glue 101 pressed by the first pressing roller 20 and the second pressing roller 30. The light guide pipe 46 is flexible and fixed on the UV lamp 44 and configured for guiding UV light beams emitted from the UV lamp 44 toward the pressed UV curable glue 101. The light guide pipe 46 can be bent toward a desired direction to control the UV light emitting direction due to the flexibility of the light guide pipe 46. Therefore, it is convenient to control the UV light emitting direction. In detail, the UV lamp 44 in the first cavity 220 emits UV light beams toward the second pressing roller 30 through the light guide pipe 46 in the first cavity 220. The UV lamp 44 in the second cavity 320 emits UV light beams toward the first pressing roller 20 through the light guide pipe 46 in the second cavity 320.
The transmission roller 50 is a hollow cylinder and positioned under the second pressing roller 30. The transmission roller 50 defines a third central axis (not labeled and which is perpendicular to the paper) in a central portion thereof and rotates about the third central axis. The third central axis and the second central axis are arranged on a same plane, such as a common vertical plane, and parallel to each other. The transmission roller 50 is configured for transmitting the solidified UV curable glue 101 to the winding roller 60.
The winding roller 60 is a hollow cylinder and configured for winding up the solidified UV curable glue 101. The winding roller 60 defines a fourth central axis (not labeled and which is perpendicular to the paper) in a central portion thereof and rotates about the fourth central axis. The fourth central axis and the third central axis are arranged on a same plane, such as a common horizontal plane, and parallel to each other.
Referring to
In step S21, a first pressing roller 20 and a second pressing roller 30 are provided, and the first pressing roller 20 and the second pressing roller 30 are arranged side by side and spaced at a predetermined distance from each other to form a molding channel 140. Specifically, the first pressing roller 20 includes a first main body 22 and a first mold core 24. The first main body 22 is gear typed. The first main body 22 defines a first cavity 220 in a central portion thereof and a number of first teeth 222 on an outer circumferential surface thereof. The first mold core 24 is sleeved on and firmly adhered to the first main body 22. The first mold core 24 defines a number of first microstructures 242 on an outer circumferential surface thereof. The second pressing roller 30 includes a second main body 32 and a second mold core 34. The second main body 32 is gear typed. The second main body 32 defines a second cavity 320 in a central portion thereof and a number of second teeth 322 on an outer circumferential surface thereof. The second mold core 34 is sleeved on and firmly adhered to the second main body 32. The second mold core 34 defines a number of second microstructures 342 on an outer circumferential surface thereof.
In step S22, the first pressing roller 20 and the second pressing roller 30 are rotated in reverse directions to each other. In this embodiment, the first pressing roller 20 rotates clockwise, and the second pressing roller 30 rotates counterclockwise.
In step S23, hot melt UV curable glue 101 is introduced into the molding channel 140 from the feed hopper 10 and pressed by the first pressing roller 20 and the second pressing roller 30 to print first microstructures 242 and second microstructures 342 on opposite surfaces of the pressed UV curable glue 101.
In step S24, the pressed UV curable glue 101 is solidified by UV light beams to form an optical film 200. This step can be implemented by two UV lamps 44 received in the first pressing roller 20 and the second pressing roller 30. The optical film 200 defines a number of first cutouts 202 on a first surface and a number of second cutouts 204 on a second surface opposite to the first surface. The shape of the first cutouts 202 matches with that of the first microstructures 242, and the shape of the second cutouts 204 matches with that of the second microstructures 342.
In step S25, the optical film 200 is transmitted using a transmission roller 50.
In step S26, the optical film 200 is winded up using a winding roller 60.
The first pressing roller 20, the second pressing roller 30, the transmission roller 50, and the winding roller 60 can be driven by motors (not shown).
In the apparatus 100 and during the steps of the method for manufacturing the optical film 200, a carrier (such as a PET film) is omitted. Therefore, the thickness of the manufactured optical film 200 can be reduced, and the light transmission of the manufactured optical film 200 can be enhanced. Furthermore, the first teeth 222 firmly engage with the first mold core 24, and the second teeth 322 firmly engage with the second cold core 34, thereby avoiding slide of the first mold core 24 and the second mold core 34 when the hot melt UV curable glue 101 is pressed by the first pressing roller 20 and the second pressing roller 30. Moreover, the optical film 200 is easily separated from the first pressing roller 20 and the second pressing roller 30 because the first mold core 24 and the second mold core 34 of PTFE material have good adhesion resistance.
Referring to
Advantages of the apparatus 300 of the third embodiment and the method for manufacturing the optical film 400 using the apparatus 300 of the third embodiment are similar to the advantages of the apparatus 100 of the first embodiment and the method of the second embodiment.
Even though numerous characteristics and advantages of the present embodiments have been set fourth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in details, especially in the matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 101118273 | May 2012 | TW | national |
