1. Technical Field
The present disclosure relates to a mold for forming light guide plates.
2. Description of Related Art
Liquid crystal display devices typically include a backlight module for providing light for a liquid crystal panel. An essential member of the backlight module is a light guide plate.
Injection molding for molding the light guide plate usually needs a micro-structure insert to form a microstructure of an incident surface of the light plate. However, the microstructure insert is easily abraded because of repeated use.
Therefore, a light guide plate mold, which can overcome the above-mentioned problems, is needed.
The base 10, the first side plate 11, the second side plate 12, the third side plate 13, the fourth side plate 14 and the intermediate baffle 15 are substantially cubic. The base 10 includes a first side surface 101, a second side surface 102 opposite to the first side surface 101, a third side surface 103 connecting the first side surface 101 with the second side surface 102, and a fourth side surface 104 opposite to the third side surface 103. The first side plate 11 is attached to the first side surface 101. The second side plate 12 is attached to the second side surface 102. The intermediate baffle 15 is attached to the third side surface 103. The third side plate 13 is positioned in a corner formed by the second plate 12 and the intermediate baffle 15, and the fourth plate 14 is positioned in a corner formed by the first side plate 11 and the intermediate baffle 15. The length of the first side plate 11 and the length of the second side plate 12 are substantially the same as the length of the base 10. Each of the replaceable mold blocks 16 is selectively attachable to the fourth side surface 104.
The base 10 includes a top surface 110 and a bottom surface 111 opposite to the top surface 110. In the embodiment, the top surface 110 is a bottom surface of the molding cavity 20, and the top surface 110 is parallel to the bottom surface 111. In other embodiment, the top surface 110 may be inclined to the bottom surface 111. When the top surface 110 is parallel to the bottom surface 111, the light guide plate 21 is flat. When the top surface 110 is inclined to the bottom surface 111, the light guide plate 21 is wedge-shaped.
The optical micro-structure insert 17 is a metal sheet with a thickness equal to a depth of the molding cavity 20. In the embodiment, the optical micro-structure insert 17 is substantially T-shaped. The optical micro-structure insert 17 includes a fixing portion 171 and a molding portion 172 connected with an end of the fixing portion 171. An end surface of the molding portion 172 bounding the molding cavity 20 defines a number of grooves 1721. The grooves 1721 are used for molding microstructure 210 of an incident surface of the light guide plate 21 (see
The material of the fixing portion 171 is stainless steel. The material of the molding portion 172 is soft metal such as copper, gold or nickel and any combination thereof. The molding portion 172 can be processed to form new grooves when former grooves 1721 are abraded. The molding portion 172 of the optical microstructure insert 17 becomes short after process, so it is necessary to replace the replaceable block 16 after the process in order to match with the size of the optical microstructure insert 17. Thus, failure forming the light guide plate 21 can be avoided. The molding portion 172 can be processed to form new recesses after the old recesses have been abraded. Thus, the using life of the light guide plate mold is increased, and the cost of the light guide plate molding is reduced.
The depth L of the grooves 1721 is less than the length H of the molding portion 172. In this way, the molding portion 172 can be processed more than one time. When the grooves 1721 is abraded, the abraded grooves 1721 will be polished smoothly via an ultra-precision machining, then new grooves 1721 on the molding portion 172 is achieved.
It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set forth 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 detail, especially in matters of shape, size, and arrangement of portions 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 |
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101143812 | Nov 2012 | TW | national |