03-07-2012, 11:49 AM
FMD (Fluorescent Multilayer Disk)
[attachment=26493]
INTRODUCTION
Compact discs were a revolutionary product at its time and influenced
many spheres of human activity. People started recording music of high quality,
which didn't get worse with the time as it happens to be on tape. As soon as CDs
appeared in computer industry they immediately became an undoubted helper both
for users and for programmers. The latter were able to increase volume of their
program products by adding video and audio elements etc. Later discs were used
for digital video (VideoCD).
But technologies are progressing. Data are growing faster and faster. A usual
CD is far not enough (640 MBytes). So, there appeared DVD technology. Of course
we are happy with those 17 GBytes that can be kept on one DVD disc, but this is a
limiting point. So we need a completely new method of storing information on
portable data medium. And at last, the company Constellation 3D demonstrates a
new format: FMD (Fluorescent Multilayer Disk), which can soon become a leader
Constellation 3D's technology implements the concept of the volumetric
storage of information. Data is recorded on multiple layers located inside a disc or a
card, as opposed to the single layer method available in compact discs, and double
layer method available in DVD’s. The recording, reading and storing of the
information is accomplished through the use of fluorescent materials embedded in
pits and grooves in each of the layers. The fluorescent material emits radiation
when excited by an external light source. The information is then decoded as
modulations of the intensity and color of the emitted radiation.
Dept. of Computer Engg. W.P.T.C., Kalamassery
OPTICAL STORAGE MEDIA USED TODAY
CD-ROM
The CD-ROM standard was established in 1984 when the CD-audio
standard was modified to give PCs access to the technology. CD-ROM drives and
discs quickly evolved into a low-cost digital storage option because of the
established CD-audio industry. Data bits are permanently stored on a CD in the
form of physically molded pits in the surface of a plastic data layer that is coated
with reflective aluminum. Smooth areas surrounding pits are called lands.
CDs are extremely durable because the optical pickup (laser light source,
lenses and optical elements, photoelectric sensors, and amplifiers) never touches the
disc. Because data is read through the disc, most scratches and dust on the disc
surface are out of focus, so they do not interfere with the reading process. With a
650-MB storage capacity, one CD-ROM disc can store the data from more than 450
floppy disks. Data access speeds are reasonable, with random access rates ranging
from 80 to 120 ms for any data byte on the disc. Maximum data transfer rates are
approximately 5 MB/ sec. These attributes make CD-ROMs especially well suited
for storing large multimedia presentations and software programs.
CD-ROM drives are distinguished by different disc rotation speeds
measured relative to the speed of an audio CD player. A 1X CD-ROM accesses data
at approximately 150 kilobytes per second (KB/sec), the same as an audio player. A
32X CD-ROM reads data thirty-two times faster at approximately 4,800 KB/sec. In
general, faster speeds reduce data access time, but vibration and noise problems
limit maximum speeds to approximately 48X.
DVD ROM
The DVD ROM standard, introduced in 1995, came about as the result of a
DVD Consortium composed of ten founding companies viz. Hitachi, Matsushita
Electronic,
Mitsubishi Electric, Toshiba, Time Warner, Pioneer Electric, Thomson Multimedia,
Victor Company of Japan, Sony, and Philips Electronics.
Like CD drives, DVD drives read data through the disc substrate, reducing
interferences from surface dust and scratches. However, DVD-ROM technology
provides seven times the storage capacity of CD discs, and accomplishes most of
this increase by advancing the technology used for CD systems. The distance
between recording tracks is less than half that used for CDs .The pit size also is less
than half that on CDs, which
requires a reduced laser wavelength to read the smaller-sized pits. These features
alone give DVD-ROM discs four times the storage capacity of CDs. MultiRead is
an international trade association standard for CD-ROM and DVD-ROM drives that
increases amplification so the photodiodes in the drive can detect the lower contrast
between the pits and lands of CD-RW discs.
Other features include a more efficient error correction code (ECC). Fewer
data bits are required for error detection, thus freeing space for recorded data. DVD
discs can also store two layers of data because they can have a translucent reflective
layer with data on top of a second opaque reflective layer containing more data. The
drive changes the focus of the laser to switch between the two data layers.
DVD-ROM drives rotate the disc more slowly than CD drives, but data
throughput is considerably higher be-cause the data density is much greater than on
CDs. A 1X DVD-ROM drive has a data transfer rate of 1,250 KB/ sec compared
with a 150-KB/sec data transfer rate for a 1X CD-ROM drive. Current DVD-ROM
drives can read DVD discs at 12X maximum speeds and can read CDs at 40X
maximum speeds.
DVD-ROM discs provide a 4.7-GB storage capacity for single-sided, single
data-layer discs. Single sided, double data-layer discs increase the capacity to 8.5
GB. Double-sided, single data-layer discs offer 9.4 GB, and double-sided, double
Dept. of Computer Engg. W.P.T.C., Kalamassery
data-layer discs pro-vide 17 GB of storage capacity. DVD-ROM drive costs range
from $200 to $500, and also read CD-ROM, CD-R, CD-RW, and DVD-R discs. As
new software programs push the storage limits for CD-ROM discs, DVD-ROM
discs offer storage capacities that should satisfy these requirements for many years
to come.
FLUORESCENT MULTILAYER DISK (FMD)
OVERVIEW
Compact Disc (CD) and Digital Versatile Disc (DVD) use single and dual
metallic layers, respectively, to store data in pits and grooves, similar to the way
grooves store music on vinyl records.
The limitation of CD and DVD is that the laser cannot accurately penetrate
the solid, reflective layer where data is stored. In the case of DVD, the laser can
penetrate one layer deep to read the second layer, but after that, the laser becomes
diffused and unable to read the data clearly. FMD-ROM is a totally clear disc.
Instead of reading a single layer, the data is stored on fluorescent materials in
multiple layers, which give off light.
[attachment=26493]
INTRODUCTION
Compact discs were a revolutionary product at its time and influenced
many spheres of human activity. People started recording music of high quality,
which didn't get worse with the time as it happens to be on tape. As soon as CDs
appeared in computer industry they immediately became an undoubted helper both
for users and for programmers. The latter were able to increase volume of their
program products by adding video and audio elements etc. Later discs were used
for digital video (VideoCD).
But technologies are progressing. Data are growing faster and faster. A usual
CD is far not enough (640 MBytes). So, there appeared DVD technology. Of course
we are happy with those 17 GBytes that can be kept on one DVD disc, but this is a
limiting point. So we need a completely new method of storing information on
portable data medium. And at last, the company Constellation 3D demonstrates a
new format: FMD (Fluorescent Multilayer Disk), which can soon become a leader
Constellation 3D's technology implements the concept of the volumetric
storage of information. Data is recorded on multiple layers located inside a disc or a
card, as opposed to the single layer method available in compact discs, and double
layer method available in DVD’s. The recording, reading and storing of the
information is accomplished through the use of fluorescent materials embedded in
pits and grooves in each of the layers. The fluorescent material emits radiation
when excited by an external light source. The information is then decoded as
modulations of the intensity and color of the emitted radiation.
Dept. of Computer Engg. W.P.T.C., Kalamassery
OPTICAL STORAGE MEDIA USED TODAY
CD-ROM
The CD-ROM standard was established in 1984 when the CD-audio
standard was modified to give PCs access to the technology. CD-ROM drives and
discs quickly evolved into a low-cost digital storage option because of the
established CD-audio industry. Data bits are permanently stored on a CD in the
form of physically molded pits in the surface of a plastic data layer that is coated
with reflective aluminum. Smooth areas surrounding pits are called lands.
CDs are extremely durable because the optical pickup (laser light source,
lenses and optical elements, photoelectric sensors, and amplifiers) never touches the
disc. Because data is read through the disc, most scratches and dust on the disc
surface are out of focus, so they do not interfere with the reading process. With a
650-MB storage capacity, one CD-ROM disc can store the data from more than 450
floppy disks. Data access speeds are reasonable, with random access rates ranging
from 80 to 120 ms for any data byte on the disc. Maximum data transfer rates are
approximately 5 MB/ sec. These attributes make CD-ROMs especially well suited
for storing large multimedia presentations and software programs.
CD-ROM drives are distinguished by different disc rotation speeds
measured relative to the speed of an audio CD player. A 1X CD-ROM accesses data
at approximately 150 kilobytes per second (KB/sec), the same as an audio player. A
32X CD-ROM reads data thirty-two times faster at approximately 4,800 KB/sec. In
general, faster speeds reduce data access time, but vibration and noise problems
limit maximum speeds to approximately 48X.
DVD ROM
The DVD ROM standard, introduced in 1995, came about as the result of a
DVD Consortium composed of ten founding companies viz. Hitachi, Matsushita
Electronic,
Mitsubishi Electric, Toshiba, Time Warner, Pioneer Electric, Thomson Multimedia,
Victor Company of Japan, Sony, and Philips Electronics.
Like CD drives, DVD drives read data through the disc substrate, reducing
interferences from surface dust and scratches. However, DVD-ROM technology
provides seven times the storage capacity of CD discs, and accomplishes most of
this increase by advancing the technology used for CD systems. The distance
between recording tracks is less than half that used for CDs .The pit size also is less
than half that on CDs, which
requires a reduced laser wavelength to read the smaller-sized pits. These features
alone give DVD-ROM discs four times the storage capacity of CDs. MultiRead is
an international trade association standard for CD-ROM and DVD-ROM drives that
increases amplification so the photodiodes in the drive can detect the lower contrast
between the pits and lands of CD-RW discs.
Other features include a more efficient error correction code (ECC). Fewer
data bits are required for error detection, thus freeing space for recorded data. DVD
discs can also store two layers of data because they can have a translucent reflective
layer with data on top of a second opaque reflective layer containing more data. The
drive changes the focus of the laser to switch between the two data layers.
DVD-ROM drives rotate the disc more slowly than CD drives, but data
throughput is considerably higher be-cause the data density is much greater than on
CDs. A 1X DVD-ROM drive has a data transfer rate of 1,250 KB/ sec compared
with a 150-KB/sec data transfer rate for a 1X CD-ROM drive. Current DVD-ROM
drives can read DVD discs at 12X maximum speeds and can read CDs at 40X
maximum speeds.
DVD-ROM discs provide a 4.7-GB storage capacity for single-sided, single
data-layer discs. Single sided, double data-layer discs increase the capacity to 8.5
GB. Double-sided, single data-layer discs offer 9.4 GB, and double-sided, double
Dept. of Computer Engg. W.P.T.C., Kalamassery
data-layer discs pro-vide 17 GB of storage capacity. DVD-ROM drive costs range
from $200 to $500, and also read CD-ROM, CD-R, CD-RW, and DVD-R discs. As
new software programs push the storage limits for CD-ROM discs, DVD-ROM
discs offer storage capacities that should satisfy these requirements for many years
to come.
FLUORESCENT MULTILAYER DISK (FMD)
OVERVIEW
Compact Disc (CD) and Digital Versatile Disc (DVD) use single and dual
metallic layers, respectively, to store data in pits and grooves, similar to the way
grooves store music on vinyl records.
The limitation of CD and DVD is that the laser cannot accurately penetrate
the solid, reflective layer where data is stored. In the case of DVD, the laser can
penetrate one layer deep to read the second layer, but after that, the laser becomes
diffused and unable to read the data clearly. FMD-ROM is a totally clear disc.
Instead of reading a single layer, the data is stored on fluorescent materials in
multiple layers, which give off light.