Patent number 8540503 is assigned to
The following quote was obtained by the news editors from the background information supplied by the inventors: "The present invention relates to a disk substrate molding apparatus, a disk substrate molding method and a disk substrate molding die.
"A disk-shaped optical recording medium with a substrate made of resin has been put into practical use as a large-capacity, low-cost information recording medium. For example, as this kind of optical recording medium, there are a CD (compact disk), a DVD (digital versatile disk), and a BD (Blu-ray disk). The resin substrate of this optical recording medium is manufactured with the injection molding method from the perspective of shortening the manufacturing time. With this molding method, molten resin is filled in a cavity formed within a die, and the resin is solidified and subsequently removed from the die.
"FIG. 13 shows an example of a conventional die. In FIG. 13, reference numeral 101 shows a fixed-side die, and reference numeral 102 shows a movable-side die. The space created by closing the fixed-side die 101 and the movable-side die 102 is a cavity 103. The cavity 103 is where the molten resin is filled and molded into a substrate.
"The fixed-side die 101 comprises a sprue bush 104 and a fixed-side mirror plate 105, and these are disposed in order from the inner circumferential side. The sprue bush 104 is a member for causing the molten resin extruded from a nozzle (not shown) of the injection molding machine to flow into the die. A water passage 106 is formed on the fixed-side mirror plate 105, and the temperature of the fixed-side mirror plate 105 is controlled by causing temperature controlled water to circulate in the water passage 106. The sprue bush 104 and the fixed-side mirror plate 106 are joined with the fixed-side plate 107. The fixed-side mirror plate 105 is fitted into the outer circumferential ring 108 and joined via a spring 109. The outer circumferential ring 108 is a member for deciding the outer circumferential end shape of the substrate.
"The movable-side die 102 comprises an ejector pin 110, a cut punch 111, an ejector 112, a stamper holder 113 and a movable-side mirror plate 114, and these are disposed in order from the inner circumferential side. The cut punch 111 is a member for forming an inner hole in the molten resin that was filled in the cavity 103. The ejector pin 110 and the ejector 112 protrude from the mirror disk 114 after the molten resin is solidified. The ejector pin 110 and the ejector 112 are used for removing, from the movable-side die, the substrate part molded from the molten resin and the unneeded part in a mutually separated state. The stamper holder 113 is used for retaining the stamper 115 with the movable-side mirror plate 114. The stamper 115 is used for forming fine concavity and convexity on the substrate surface, and is generally made of nickel. The movable-side mirror plate 114 is also formed with a water passage 116 as with the fixed-side mirror plate 105. The temperature of the movable-side mirror plate 114 is controlled by causing temperature controlled water to circulate in the water passage 16. Note that, in FIG. 13, reference numeral 117 is a movable-side plate, and the movable-side mirror plate 114 is joined with the movable-side plate 117.
Most Popular Stories
- Updates on Everglades' Stranded Pilot Whales
- Hezbollah Chief's Assassination Claimed by Sunni Group
- Stolen Cobalt-60 Recovered in Mexico
- Wind Power and Wildlife Can Coexist
- Ford Mustang Still Packs Power
- NSA Tracks 5 Billion Cellphone Records a Day
- Allstate Seeks to Invest in Minority Firms
- Sarmiento to Handle Greeley Latin Ops
- First-time Jobless Claims Drop Below 300,000
- White House Pushes to Extend Unemployment Benefits