TDK Begins Shipping Mass Production Samples Of Bare, Cartridge-Free BD-R (Write-Once) And BD-RE (Rewritable) Blu-ray Discs

January 9, 2006

TDK Corporation has begun shipping massproduction samples of its bare, cartridge-free BD-R (write-once) and BD-RE (rewritable) Blu-ray Discs. The four new products include the BD-R25 (single-sided, single-layer, 25GB) and BD-R50 (single-sided, dual-layer, 50GB) write-once type discs, as well as the BD-RE25 (single-sided, single-layer, 25GB) and BD-RE50 (single-sided, dual-layer, 50GB) rewritable discs. Mass production for the retail market will begin at TDK’s Chikumagawa factory, which specializes in optical media, when final licensing is issued. Driven by the continuously expanding data storage requirements of today’s digital society, as well as the rapid emergence of high-definition broadcasting, demand has grown for discs that achieve larger capacities and higher-speed recording than previous formats. The BD-R and BD-RE products introduced by TDK are bare, cartridge-free discs that rise to the challenge by delivering larger capacities and high speed recording without requiring a cumbersome cartridge to ensure reliability. For the Blu-ray Disc, which utilizes ultra-high density recording to achieve its large capacities, scratches or dirt on the disc surface can cause data errors. To ensure reliable performance, the Blu-ray Disc was first introduced to the Japanese market in a protective cartridge. The BD-R and BD-RE Blu-ray Discs that TDK is now launching utilize DURABIS 2, the company’s exclusive hard coating technology. DURABIS 2 gives the recording surface extremely high resistance to scratches, fingerprint smudges and other dirt, thus eliminating the need for a protective cartridge. TDK’s proprietary high-precision Spin Coating manufacturing process is utilized to form each Blu-ray Disc’s cover layer, which resides atop the recording layer. Because Spin Coating creates a cover layer with nano-uniform smoothness, exceptionally stable recording and playback characteristics are realized. The write-once type BD-R discs incorporate inorganic recording material, which is entirely different from the organic dye used in previous write-once discs. Because the recording layer is not affected by light, the discs are exceptionally suitable for long-term archiving. The rewritable type BD-RE discs utilize a high-sensitivity phase-change recording material that displays stability and a low error rate, even after 10,000 overwrites. In addition, the single-sided, dual-layer 50GB TDK Blu-ray Discs utilize high-precision stacking technology to achieve precise formation of disc layers. Using this technology, which was developed over a number of years, the upper layer (Layer 1) and lower layer (Layer 0) are combined to realize stable recording and playback characteristics. TDK’s massive R&D efforts in advanced optical disc technology have enabled creating the world’s first 25GB and 50GB high-capacity discs capable of 2X recording speed. TDK is confident that the BD-R and BD-RE, freed from the confines of a cartridge, will find widespread consumer acceptance by delivering unprecedented capacities and speeds. Main Features of TDK BD-R and BD-RE Blu-ray Discs 1. Exclusive DURABIS 2 coating designed for bare Blu-ray Discs provides significantly greater resistance to scratches, fingerprints and dirt, ensuring reliability without a cartridge. 2. Proprietary high-precision Spin Coating creates a cover layer with uniform smoothness to the nano-level, realizing stable recording and playback. 3. The write-once type BD-R media utilizes inorganic recording layer material. Because the material is unaffected by exposure to light, it’s ideal for archiving applications. 4. The rewritable BD-RE utilizes high-sensitivity phase-change recording material that maintains stable characteristics even after as many as 10,000 rewrites. 5. High-precision stacking technology precisely overlays disc layers. This realizes stable performance characteristics for the upper layer (Layer 1) and lower layer (Layer 0) of TDK’s single-sided, dual-layer 50GB Blu-ray Discs. TDK’s Blu-ray Disc Product Line-Up TDK is launching four Blu-ray Disc products as follows: BD-R (write-once type) 1. BD-R25 (single-layer, 25GB) 2. BD-R50 (dual-layer, 50GB) Main Features of TDK BD-R and BD-RE Blu-ray Discs 1. Exclusive DURABIS 2 coating designed for bare Blu-ray Discs provides significantly greater resistance to scratches, fingerprints and dirt, ensuring reliability without a cartridge. Since the area of the laser spot on the Blu-ray Disc is small (about one-fifth that of the DVD), scratches or dirt on the disc’s recording surface can have a more serious effect than with DVDs. Laser tracking errors and, even worse, irrevocable data loss can result. That’s why TDK utilizes DURABIS 2 hard coating, specially developed for the bare Blu-ray Disc, on its BD-R and BD-RE media. Along with significantly higher resistance to scratches, DURABIS 2 also delivers superior fingerprint and dirt resistance, ensuring reliability without a cartridge. (Figs. 1, 2 and 3.) 2. Proprietary high-precision Spin Coating creates a cover layer with uniform smoothness to the nano-level, realizing stable recording and playback. The Blu-ray Disc is constructed of a 1.1mm thick substrate with a 0.1mm thick cover layer. Because the laser beam passes through the cover layer in its path to the recording layer, the cover layer essentially assumes the function of a lens. For this reason, the precision and smoothness of the cover layer is extremely important to ensuring precise laser tracking for the Blu-ray Disc, which uses a short-wavelength blue-violet laser. To form this cover layer, TDK utilizes high-precision Spin Coating. The process controls the thickness of the cover layer to the nano-level, forming an outstanding surface. This uniformity reduces the load on the servo circuit, which is used to correct the laser beam position. Reducing the load on the servo circuit helps ensure stable recording and playback. 3. The write-once type BD-R media utilizes inorganic recording layer material. Because the material is unaffected by exposure to light, it’s ideal for archiving applications. Previous types of write-once type discs, such as the CD-R and DVD-R, utilized organic dye recording layer material. TDK write-once BD-R discs use a completely new recording layer material featuring an inorganic two-layer structure composed of silicon (Si) and copper alloy (Cu). When heated by the recording laser beam, the silicon and copper melt, creating a composite and forming the recording marks. Because the material is inorganic, it is not affected by light, and is, therefore, ideal for archival. 4. The rewritable BD-RE utilizes high-sensitivity phase-change recording material that maintains stable characteristics even after as many as 10,000 rewrites. For the rewritable BD-RE discs, an exclusive high-sensitivity phase change recording material and a layer structure specially designed for high-density recording are utilized to realize excellent recording/playback and overwrite characteristics. Even after 10,000 rewrites, TDK BD-RE discs still exhibit stable performance characteristics. 5. High-precision stacking technology precisely overlays disc layers. This realizes stable performance characteristics for the upper layer (Layer 1) and lower layer (Layer 0) of TDK’s single-sided, dual-layer 50GB Blu-ray Discs. The single-sided, dual-layer TDK Blu-ray Disc with tremendous 50GB capacity was made possible by high-precision stacking technology developed through years of TDK R&D in optical recording. The recording layers (Layers 0 and 1), dielectric layers, spacer layer and a cover layer are formed with high precision to a total thickness 0.1mm (100?m). TDK technology enables exactly matching Layer 0 and Layer 1 in terms of precision and recording layer transparency ratio for stable recording and playback characteristics.

Read More: