LightScribe
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LightScribe is an optical disc recording technology that utilizes specially coated recordable CD and DVD media to produce laser-etched labels with text or graphics, as opposed to stick-on labels and printable discs.
The LightScribe method uses the laser in a way similar to when plain data is written to the disc; a greyscale image of the label is etched onto the upper side of the disc. The required discs come in many colors.
The purpose of LightScribe is to allow users to create direct-to-disc labels (as opposed to stick-on labels), using their optical disc writer. Special discs and a compatible disc writer are required. Before or after burning data to the read-side of the disc, the user simply turns the disc over and inserts it with the label side down. The drive's laser then etches into the label side in such a way that an image is produced.
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[edit] History
LightScribe was conceived by HP engineer Daryl Anderson[1] and brought to market through the joint design efforts of HP's imaging and optical storage divisions[2] in 2004.[3] Daryl is no longer actively associated with Lightscribe.
[edit] Mode of operation
The surface of a LightScribe disc is coated with a reactive dye that changes color when it absorbs 780nm infrared laser light. The etched label will show no noticeable fading under exposure to indoor lighting for at least 2 years. Optical media should always be stored in a protective sleeve or case that keeps the data content in the dark and safe from scratches. If stored this way, the label should last the life of the disc in real-world application.
LightScribe labels burn in concentric circles, moving outward from the center of the disc. Images with the largest diameters will take longest to burn.
LightScribe is monochromatic, initially a grey etch on a gold looking surface. From late 2006, LightScribe discs are also available in various surface colors, under the v1.2 specification. The etching is still in shades of grey.
Currently it's not possible to replace a LightScribe label with a new design, but it is possible to add more content to a label that is already burned.
The center of every LightScribe disc has a special code that allows the drive to know the precise rotational position of the disc. This in combination with the drive hardware allows it to know the precise position from the center outwards, and the disc can be labeled while spinning at high speed using these references. It also serves a secondary purpose: The same disc can be labeled with the same label again, several times. Each successive labeling will darken the blacks and generally produce a better image, and the successive burns will register up perfectly.
[edit] Drawbacks
Special storage precautions are necessary to prevent LightScribe discs from fading. HP's LightScribe website warns users to "keep discs away from extreme heat, humidity and direct sunlight", "store them in a cool, dark place", "use polypropylene disc sleeves rather than PVC sleeves", and also notes that "residual chemicals on your fingers could cause discoloration of the label image". Such chemicals include common hand lotions and hair care products.[4] Users not observing these precautions have reported LightScribe discs to become visibly faded within two months in the worst case. This drawback makes the technology unsuitable for applications involving continuous handling, and for such popular uses as car music compilation disks which typically have unavoidable high exposure. Since many disc players present internal temperatures significantly higher than room temperature, LightScribe discs should also not be left in disc players for long periods of time.
Lightscribe discs may form a visible white powder coating. This is due to crystallization of some of the label-side coating. It is not harmful and can easily be removed with a water-dampened cloth. Wiping the disc with a damp cloth does not harm the inscribed label.[5] Up until now, LightScribe support has not explained which conditions lead to this reaction, nor the precautions that can be taken to avoid it.
Multiple Lightscribes of the same image increases contrast, but the image quality decreases with increased burns. Noticeable contrast variations are seen in solid shades.
[edit] References
- ^ HP Online classes - Getting started with LightScribe
- ^ HP LightScribe - frequently asked questions
- ^ HP's invention, due in drives soon, lets users burn labels directly onto discs
- ^ LightScribe.com: Support: FAQ: Burning a Label
- ^ LightScribe.com: Support: FAQ: Support and System Software
[edit] See also
- LabelFlash, a similar but incompatible technology
- DiscT@2
- Labeltag
- U.S. Patent 7,172,991 -- "Integrated CD/DVD recording and labeling", Daryl E. Anderson, Makarand P Gore, Paul J McClellan, Hewlett-Packard Development Company
