Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Title: DIGITAL INFORMATION GUARD
Inventor: Arnold L. Park
F~ELD OF THE INVENTION
The present invention relates to protective devices for optical discs
containing data, music and the like. In particular the invention relates to the
10 field of protection for the play side of a variety of optical discs, including
standard audio CD's, Sega Saturn(~), Sony Playstation(~, Panasonic 3Di(~,
computer CD Roms and any other forms of "CD's", including larger "laser
discs" and karaoke CDs.
15 BACKGROUND OF THE INVENTION
With the development of optical disc technology (compact discs,
laser discs, DVD discs et.) their use has increased dramatically. Many differenttypes of information are now stored on these types of discs which are used in
20 the home, the workplace, in the automobile and with portable equipment.
The optical disc stores information digitally. The stored information
is used by computers by reading tiny grooves and peaks as binary data. In
audio CD players the Digital to Analog Converter (DAC) is used to turn the
digital information to analog signals that can be heard as sound. Optical discs
25 have two sides, the information side (generally the one with the label on it)and the read or play side (the shiny clear side). The preferred outer material in
most of these discs is a poly-carbon. The poly-carbon encases the data layer
and provides the shape and structural integrity for the disc. Due to the
softness of poly-carbons however, surface damage is quite common. If the
3 o surface of an optical disc is scratched for example, the laser beam used to read
the data is often reflected or misdirected resulting in mis-tracking or skipping.
The information side has a gloss coating that help in protecting it,
but the read side has no protection of any sort except for the jewel case,
which only protects it during storage. Unfortunately most damages to the di~c
35 occurs during transition from the case to players or by mishandling. When a
disc is damaged by scuffs or a scratch, the end result is loss of information.
This translates to skipping and in some cases stopping of the disc playing
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device. In some audio CD players a technology called over-sampli~7gis used
to compensate for some information loss by filling in the missing data. This
does help somewhat in allowing CDs to be still useable even with scuffs but it
is very limited. In most cases over-sampli~g does not help in common types of
scratches. This invention is designed to protect the CD by placing a
protective cover on the read side where most of the damage occurs.
When being stored discs are typically placed in a rigid container
(jewel case) which protects both the data side and the label side of the disc.
When in use however the discs remain unprotected. Most of the damage
occurs when discs are being transferred from storage to the reading/writing
device.
Prior art devices do exist. Some require a centering adapter to
ensure proper alignment. Others use adhesives, which can migrate oJf the
surface or even to the disc which could damage the surface. Yet others are
difficult to attach and remove.
A prior art device is disclosed in United States Patent No. 4,983.437
entitled "Compact Disc Protector". This device only protects the information
(top) side of the disc. The information side of the disc is generally more
resilient to damage as compared to the unprotected play (bottom) side. The
information side typically has a protective lacquer coating whereas the bottom
side usually does not.
United States Patent No. 4,879,7 l0 entitled "Optical Disc Protector
and Method for Applying Same" also discloses a protective device for optical
discs. This device uses adhesive to attach the protector to the disc.
It would be desirable to have an easily attachable device that
remains on the disc when in use and in storage. The protective device would
have to permit normal functioning of the disc and would have to be capable ol'
being securely attached. The ideal device would effectively be invisible to the
user, providing added protection without any significant loss of convenience
3 o or utility.
The present invention overcomes problems associated with the
prior art devices by providing protection to the read/ play side of the disc andby allowing the end user to apply the device without the use of a special
applying tool or adhesives. The use of adhesives may cause problems to the
3 5 disc because of chemical reactions and also the migratory properties of
adhesives. The end result is that the present invention will be easier to apply
and will elimin~te the use of any form of adhesives. Also because of the fact
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that it does not use adhesives, the present invention will be flexible and easier
to replace if it incurs damage due to mishandling.
The prior art uses materials that were different from the CD itself.
This could result in bubbling or the protective devices not fitting on to the CDproperly due to therrnal expansion or contraction. The present invention is
designed to elimin~te this problem by expanding or contracting at the same
rate as the disc even at extreme temperature fluctuations. This ensures a
precise fit for the protective device to the disc.
SUMMARY OF THE INVENTION
The present invention is designed to protect an optical disc by
means of providing a secondary protective cover that does not interfere with
the handling or the reading of the disc. It has been found that optical discs
such as CD's, can be effectively played with a secondary layer attached to
their surfaces as a protective cover. The cover of the present invention is
easily applied by the user, in no way damages or alters the original integrity of
the disc.
In accordance with the present invention there is provided an easily
detachable protective cover for the play side of an optical disc. In the
preferred embodiment the protector is made of poly-carbon film. The protector
is annular in shape and is appropriately sized to fit the various disc formats.
There is provided an inner crevice that fits the inner molding of a disc allowing
for greater structural integrity and which assists in the placement of the
protector on the disc. The device is attached to the disc using several clil3.s
that are located around the perimeter.
Further features of the invention will be described or will become
apparent in the course of the following detailed description.
3 o BRIEF DESCRIPI ION OF THE DRAWINGS
The present invention is depicted and described in the
accompanying drawings wherein like reference numerals refer to like parts in
the several views, and wherein:
l~ig. 1 is a top view of the protective cover of the present invention
as installed around a disc; and
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Fig. 2 is a side view showing the spaced relation of the protective
cover and the disc.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to Figs. l and 2, a protective cover according to
the present invention, generally indicated at l, is applied to the play (read)
side of an optical disc 2. The cover l is formed fi-om a material that is
transparent and allows the laser o~~ a CD player to read all information from the
disc. The cover 1 is intended to remain in place for the duration of the life ofthe protector which will vary depending on the use and environment in which
it is used.
The cover l is made of poly-carbon (polycarbonate) film: the
same material as the disc itself is made. Poly-carbon was chosen so there
would be a consistent rate of contraction or expansion relative to the discs
due to thermal variance in the environment. Poly-carbon was also chosen for
this device because of its "memory" properties which allow it to retain its
shape after it has been manufactured. The properties of the material should be
as follows:
The temperature resistance level ideal should be so that the
material does not lose any memory even at a high temperature. The
polycarbon is able to retain such form and will not melt until 250 F degrees.
Polycarbon also has a fairly stable moisture absorption level and
at the same time thermal dimensional coefficient is low.
The polycarbon is fairly resistant to impact and holds the
memory of a formed shape very will.
The most important characteristics of polycarbon is that it is very
clear with very little distortion. This allows for the laser to pass through it and
read the disc within the tolerance level so that information for it can be read.3 C The cover l of the present invention itself is shaped to fit a disc
so that it will not slip or move once it is in place. The cover l consists of a
generally flat transparent body portion 3 having substantially the same
surface area as the disc 2. The thickness of the body portion 3 is preferably
about 50 microns thick although this can be varied as long as the thickness
3 5 does not exceed the tolerance level that will allow the disc player to read it.
The body portion 3 protects the read/play surface of the disc.
This is the part of the cover that will eventually get damaged by handling.
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The protective cover also has an inner crevice or groove that
functions to provide structural integrity to hold its flat shape. This groove isformed by embossing or the like. It also assists in the placement of the
protector over the disc by using the disc's nipple from the mold injection as a
5 guide for the user to apply the protector and provide a more exact fit. In theembodiment shown the groove 4 is provided on the body portion 3 for higllel-
structural integrity and at the same time hold the disc and the protective coverin place. This groove 4 is aligned with the grooves found on all discs. Ideally
in the trough 5 of the groove 4 of the protective cover there is provided some
10 material, high in friction coefficient that is non-adhesive. The preferred
material is found in most signs that stick to smooth surfaces like glass.
The groove 4 not only provides structural integrity by because
of the grabbing effects of the material in the groove it provides a hold in the
disc players.
Means is provided at the periphery of the cover to assist in
retaining the cover in place. In the embodiment shown in Figs. l and 2 a series
of clips 6 are provided on the circumference of the protective cover l. Each
clip is shaped like a "C" and acts to hold the disc and protector together.
One embodiment includes 6 to 20 flexible clips that are located around the
2 o perimeter of the disc. These clips can be cornered or rounded depending on
the design. In the preferred embodiment shown six clips are provided with
each of the clips 6, 60 degrees rad apart from each other. This is done so tha
the centrifugal force of the spinning disc will not throw of the protective
device. Four of the clips 7 are larger than the last two 8. This is made this way
25 so that a disc may be slid in to its proper position then the last two clips would
snap on with little pressure. The four clips 7 have a rounded shape so the
there is no sharp edges that may damage the disc. The two remaining clips 8
are also rounded but are shorter in length then the other four. The clips 6
hold the protective cover in place on the disc. The clips 6 are attached to the
3 o protective cover l by walls 9 which extend at 90 degree from the body
portion 3 of the protective cover. The relative width of each wall ideally
should bel/S of a centimeter, but this width can be changed as long as it do
not form a sharp edge. The center l0 of the protective cover is cut out in the
same diameter as the opening on the disc. The space between the cut center
3~ and the groove is used by the disc player to help hold hold the protector
cover l in place with pressure during use.
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It will be appreciated that the above description related to the
preferred embodiment by way of example only. Many variations on the
invention will be obvious to those knowledgeable in the field, and such
obvious variations are within the scope of the invention as described and
5 claimed whether or not expressly described.
