Thin Optical Disk Stabilization Technology Using Air Bearing
Stable Rotation of Thin Optical Disks by Means of an Air Stabilizer Plate
The overall configuration is shown in Figure 1. To the right is a cartridge in which multiple thin optical disks are stored. As disk thickness is about the same as that of a sheet of paper (0.1mm), the thickness of a cartridge loaded with ten disks can be kept to less than a centimeter. To the left is a structure configured by adding an air stabilizer plate to an ordinary optical disk drive.
Figure 1: Overall configuration of a thin disk drive
The difference in the state of disk rotation according to whether or not a stabilizer plate is used is readily apparent from the video clips below.
|Video 1: Rotation without a stabilizer plate||Video 2: Rotation with a stabilizer plate|
Benefits of Thin Disks
On the other hand, in the case of thin optical disks stabilized using the force of air, as the force of air dampens vibrations, resonance does not occur even at speeds exceeding 10,000 revolutions per minute. Therefore, these disks can achieve data transfer at higher speeds.
Furthermore, disk stabilization makes possible thinner, flexible disks that can be loaded into cartridges in greater numbers. This makes possible a dramatic increase in disk capacity; the storage in a single cartridge of 10 disks with recording density equivalent to that of blue laser recording would provide capacity of approximately 250 gigabytes, equivalent to two hours of high-definition moving pictures for broadcasting use.
|Photo 3: Thin optical disk||Provided by NHK Science & Technical Research Laboratories
Photo 4: Thin optical disk drive
Practical Application in Broadcast Archiving and Potential for Further Application
In addition, we have enhanced applicability to high-speed rotation by applying the ZPET-FF feed forward control that Japan Broadcasting Corporation Science & Technical Research Laboratories is currently developing to reduce error in the tracking direction.
About 15 minutes of high-definition moving pictures for broadcasting use can be recorded on a single thin optical disk. One thin optical disk cartridge will make it possible to record two hours of programming, higher capacity than that of a tape for broadcasting use.
One currently envisioned application is the archiving of broadcast station video content and television programs. For instance, NHK uses an entire building as a videotape storage warehouse. It currently stores approximately one million tapes at this facility, and the number of archived tapes increases by about 40,000 each year. Tapes for broadcasting use are larger than home VHS tapes and require a large storage space. Also, long-term storage of tapes is inconvenient; for example, it is necessary to occasionally feed (and rewind) the tapes for ventilation purposes.
Provided by NHK Science & Technical Research Laboratories
Figure 2: Target performance for thin optical disks
Another expected application for thin optical disks is the storage of data currently stored using data tapes. Although signal formats for broadcasting and computers varied until ten years ago, today both are digital. A similar situation exists with respect to needs for high data transfer speed, high data capacity, and long-term storage reliability: if a storage medium suitable for broadcasting applications can be produced, application to ordinary data storage (backup tape media) will also be possible.
Ricoh has jointly developed this technology with the NHK Science & Technical Research Laboratories, a world leader in the development of broadcasting standards and electric devices.
Data Archiving Requirements
This advanced technology is highly regarded and it was awarded the Excellent Research Announcement Prize for 2008 of The Institute of Image Information and Television Engineers.
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NHK Science & Technical Research Laboratories