(a) Field of the Invention
The present invention is related to a molding tool and a process for manufacturing a diffusion film molding tool, and more particularly to a molding tool and a manufacturing process of the diffusion film molding tool that can be applied in a backlight unit.
(b) Description of the Prior Art
TFT-LCD so far a commodity that is more comprehensively as a display is essentially comprised of two members, respectively a display panel and a backlight unit to provide light source for the display panel. Depending on the location the light source is disposed the backlight unit is available in side edge emitting type and direct type. The side edge emitting type of the backlight unit is usually applied in a display of smaller size with an LED or a cold cathode fluorescent lamp (CCFL) adapted while the direct type of the backlight unit is usually applied in a display of larger size, e.g., a TV set.
In a direct type backlight unit 1 as illustrated in
As illustrated, those light sources 13 in the casing 11 when connected through will immediately emit light. Certain portion of the light directly enters into the diffuser 14 while the remaining light is reflected by the reflective film 12 to other positions in the casing 11 before re-entering into the diffuser 14. The light entering into the diffuser 14 is diffused before entering into the optical diffusion film 15 for further uniform diffusion of the light source while the BEF 16 executes light collection and gathering; and finally, sufficient and uniform light is supplied to the display panel 17 for use in displaying.
Those diffusion optical structures including the diffuser and the optical diffusion film are usually made of acrylic, polycarbonate (PC) or acrylic and styrene copolymer (MS) in sheet and are each given a certain optical permeability. To attain uniform and diffusion effects of the light source, pigment is added in the manufacturing process to make the diffusion optical structure indicating a color of milky white to facilitate diffusion and uniformity of light source. Multiple micro diffusion particles 140 are added as illustrated in
As illustrated in
The primary purpose of the present invention is to provide a molding tool and a process for manufacturing a diffusion film molding tool by providing a locating member on one side of a base plate; multiple micro-particles are arranged and secured on the base plate by means of the locating member; and the side of the base plate provided with those micro-particles are put through processes in sequence of deposition and plating to form a diffusion film molding tool. The finished diffusion film molding tool is essentially comprised of a substrate with a surface disposed of multiple indents so that when the diffusion molding tool is applied in the production of the diffusion film, multiple microstructures are form on the diffusion film that correspond to each of those indents.
Arrangement and density of those micro-particles may be arranged may vary depending on the arrangement and density of those locating members; and arrangement and density of the indents are adjusted for the diffusion optical structure formed by using the diffusion film molding tool to achieve better light diffusion and uniform diffusion results in a shorter time of the manufacturing process while providing a diffusion film with better arrangement of microstructures.
Referring to
a. Prepare a flat base plate 21 having one side disposed with a locating member 22 by adhesion or by coating.
b. Multiple micro-particles 23 are arranged on the base plate 21 using the locating member 22. Those micro-particles 23 may be disposed as to cover up on the locating member 22; as illustrated, each micro-particle 23 is made in a spherical shape and excessive micro-particles 23 are removed by shaking or vibrating so that each micro-particle 23 is secured to the base plate 21 by the locating member 22; of course, the locating member may be coated on the entire surface of the base plate as illustrated or disposed on a selected position so that those micro-particles 23 are respectively secured on their specific positions.
c. Deposition process is performed to execute physical or chemical deposition on the side of the base plate 21 where those micro-particles 23 are disposed to form a layer of metal film 31 on that side of the base plate 21.
d. Plating process is followed to the metal film layer 31 to give it a certain thickness to become a diffusion film molding tool 32, which is essentially comprised of a substrate 321, and multiple hemispherical indents each corresponding to an individual micro-particle 23 are disposed on a surface of the substrate 321 as illustrated in
Finally, a diffusion film 4 is molded using the diffusion film molding tool 32 as illustrated in
Furthermore, multiple grooves 24 are disposed on one side of the base plate as illustrated in
The prevent invention provides a molding tool for manufacturing a diffusion film, and the application for a patent is duly filed accordingly. However, it is to be noted that the preferred embodiments disclosed in the specification and the accompanying drawings are not limiting, the present invention; and that any substitution and decoration made by those who are familiar with the art of the present invention without departing from what is taught in the present invention shall be fall within the scope of the purposes and claims of the present invention.