Conventional optical data storage devices are configured to read digital data from and write digital data to a removable optical disc. Currently, writable compact discs (CD-R) and re-writable compact discs (CD-RW) are popular formats for personal computers and other like devices. Re-writable digital versatile discs (DVDs), known as DVD-RAMs (random access memory), DVD-R, DVD-R/W, etc., have also become popular as the price of the applicable DVD drive devices has become more affordable.
The process of writing data to an optical disc is often referred to as “burning” the disc, since a beam from a write laser is used to selectively raise the temperature of certain materials within the optical disc such that the materials are altered in some manner. Consequently, features are formed on the disc. These features represent binary data values, i.e., 1's and 0's, which can subsequently be detected (read) using a read laser. After burning in a CD-R, for example, the user may decide to label the CD-R disc to reflect the data files that have been stored on the disc.
The LightScribe™ printing system developed by the Hewlett-Packard Company of Palo Alto, Calif. is a direct disc labeling technology that produces optically visible text and graphics on the surface of a CD or DVD disc media using the disc drive's laser and a specially coated LightScribe disc. A LightScribe disc drive writes data (on the data side of the disc) and creates optically visible labels (on the label side of the disc) with the same drive, and may use the same laser for both operations by flipping the disc over after writing the digital data in order to create the label. Using laser technology, LightScribe's specially coated discs chemically change when a laser strikes its label side with energy of a particular wavelength, producing optically visible marks that can be arranged to form titles and graphics using LightScribe software. One embodiment of a suitable coating is described in U.S. Patent Application Publication No. 2003/0108708 A1.
It would be useful to avoid having to flip a disc over in order to label it. It would also be useful to reduce the cost or complexity of a printhead for a disc drive.