NONCIRCULAR-SHAPED COMPACT DISC HAVING POSITIONING MARKERS AND SLIDING-RESISTANCE

Abstract: A noncircular-shaped compact disc mountable in any computer compact disc drive is disclosed. The disc has two or more positioning marks and sliding-resistance means. The marks are formed on the positions, at which the exterior contour of the inside positioning depression of a disc conveying deck meets the long sides of the disc while the center of the disc is positioned at the center of the positioning depression. The sliding-resistance means is provided within the data-free area of the bottom surface of the disc, and is made of a sliding-resistance material having a large coefficient of friction. The means is adapted for preventing the disc from unexpectedly moving on the deck. The sliding-resistance means may have a longitudinal rectangular shape. The sliding-resistance means may have a circular shape. The noncircular-shaped compact disc having positioning markers and sliding-resistance may have a rectangular credit card shape. The noncircular-shaped compact disc having positioning markers and sliding-resistance may be any one of a CD-ROM capable of storing read-only data, a CD-R capable of recording data only once, and a CD-RW capable of reading, writing and erasing data many times.

Description: NONCIRCULAR-SHAPED COMPACT DISC HAVING POSITIONING MARKERS AND SLIDING-RESISTANCE Field of the Invention The present invention relates, in general, to compact discs and, more particularly, to a noncircular-shaped compact disc mountable on a compact disc drive in computers, allowing precise and easy positioning of the disc on a disc conveying deck and preventing unexpected movement of the disc on the deck due to retraction of the deck into a compact disc drive and any reasonable degree of external impact. Description of the Prior Art As well known to those skilled in the art, a conventional compact disc used in computers is circular and has a diameter of either 80mm or 120mm. The conventional compact disc is played in a compact disc drive after the disc drive has been loaded with the compact disc. The loading methods are typically classified into two types; a manual loading method wherein the compact disc is inserted onto the center of the disc drive while the cover of the disc drive is opened by hand, and an automatic loading method wherein the disc drive is automatically loaded by retracting the conveying deck into the disc drive while the compact disc has been deposited on the protruded conveyor deck. Recently, a noncircular-shaped compact disc is developed. An example of the noncircular-shaped compact disc is a rectangular-shaped CD-ROM that has a shape similar to the shape of a credit card. However, such a newly developed noncircular- shaped compact disc is problematic when loaded into the disc drive mainly due to the lack of a size- appropriate recess in the conveyor deck. When automatically or manually loading the disc drive with the noncircular-shaped compact disc when the compact disc is symmetric and is properly placed in the disc drive, vibration of the compact disc is minimized in operational rotation due to the symmetric shape. On the other hand, as shown in Fig. 5, a conventional conveying deck 10, conveying a circular- shaped compact disc into the disc drive, is provided with two-stepped tracks 11 and 12, the tracks 11 and 12 having two outside diameters respectively identical to the diameters of the two standard circular compact discs (80 mm and 120 mm) . The two tracks 11 and 12 of the conveying deck 10 function to accord the center of the placed compact disc with the center of rotation and prevent unexpected movement of the disc on the disc conveying deck despite retraction of the deck and any reasonable degree of external impact. That is, this conveying deck 10 has two positioning recesses, the positioning recesses having the exterior diameters, of 80mm and 120mm, pursuant to the exterior diameters of standard circular compact discs. Since the noncircular compact disc, which is not circular and does not have the same exterior diameter as a positioning recess, does not fit tightly within the positioning recesses of the conveying deck 10, the noncircular compact disc often moves unexpectedly on the deck 10 during retraction of the deck 10. Consequently, it is difficult to load the disc drive with the noncircular compact disc using the deck. Disclosure of the Invention Accordingly, the present invention has been made keeping in mind the aforementioned problems occurring in the prior art, and an objective of the present invention is to provide a noncircular-shaped compact disc having positioning markers and sliding-resistance on a disc conveying deck and preventing unexpected movement of the disc onto the deck despite retraction of the deck into a compact disc drive and any reasonable degree of external impact. In order to accomplish the above objective, the present invention provides a noncircular-shaped compact disc having positioning markers and sliding- resistance, comprised of: two or more positioning marks formed on the upper side of the compact disc, at which the exterior contour of the inside positioning depression of a disc conveying deck meets the long sides of the disc while the center of the disc is positioned at the center of the positioning depression; and sliding-resistance means provided within the data-free area of the bottom surface of the disc, and made of a sliding-resistant material having a large coefficient of friction, the means being adapted to prevent the disc from unexpectedly moving on the deck. The sliding-resistance means may be comprised of a thin film made of rubber, urethane or silicon. The sliding-resistance means may be comprised of a plurality of prominences and depressions integrally formed on the disc. The sliding-resistance means may have a longitudinal rectangular shape. The sliding-resistance means may have a circular shape. The markers may be printed shapes on the upper side of the disc. The markers may be carved notches on the upper side of the disc. The noncircular-shaped compact disc may have a rectangular credit card shape. The noncircular-shaped compact disc may be any one of a CD-ROM capable of storing read-only data, a CD-R capable of writing data one time, and a CD-RW capable of reading and writing data many times. Brief Description of the Drawings The above and other objectives, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Fig. 1 is a perspective view showing that a noncircular compact disc having positioning markers and sliding-resistance according to an embodiment of this invention is positioned on the disc conveying deck; Fig. 2 is a perspective view showing the noncircular compact disc having positioning markers and sliding-resistance and printed markers according to an embodiment of this invention; Fig. 3 is a plan view showing the process wherein the compact disc having positioning markers and sliding-resistance is positioned on the conveyor deck; Fig. 4a shows the bottom surface of the noncircular compact disc having positioning markers and sliding-resistance and its longitudinal rectangular-shaped sliding resistance means according to an embodiment of the invention; Fig. 4b is the bottom surface of the noncircular compact disc having positioning markers and sliding- resistance with its circular sliding resistance means according to another embodiment of the invention; and Fig. 5 is a perspective view showing a conventional disc conveying deck. Best Mode for Carrying Out the Invention In order to minimize vibration, a noncircular compact disc having positioning markers and sliding- resistance according to the preferred embodiment of this invention should have a symmetric shape. A credit card is 54 mm in height and 85 mm in width, this size being prescribed by an international standard of ISO 7816-1 and 10536. Since devices using credit cards are well known and used worldwide, the credit card-sized compact disc can be employed as a typical noncircular-shaped compact disc having positioning markers and sliding-resistance, and both credit cards and such discs may enjoy a variety of interchangeable uses. In the credit card-sized compact disc, the capacity of writing data depends upon the disc's height. The width of the disc, which is not directly related to the capacity, is 85 mm according to the above-noted international standard, while the height of the disc is 56 mm because correction allowance must be provided to prevent manufacturing error. The capacity of the disc 85 mm in width and 56 mm in height is approximately 16 MB. However, when the height of the disc is increased, the capacity becomes greater. For instance, when the height of the disc is 58 mm, the capacity increases to approximately 30 MB. Fig. 1 illustrates a noncircular compact disc 1 having positioning markers and sliding-resistance according to an embodiment of this invention, positioned on the conventional disc conveying deck 10 of Fig. 5. In Fig. 2, the credit card-sized noncircular compact disc 1 having positioning markers and sliding-resistance according to the embodiment is illustrated. Fig. 3 illustrates the process wherein the compact disc 1 having positioning markers and sliding-resistance is positioned on the deck 10. The dotted line shown in Fig. 3 and designated by reference numeral 13, is the exterior contour 13 of a first or outside positioning depression 11, while the dotted line shown in Fig. 3 and designated by reference numeral 14, is the exterior contour 14 of a second or inside positioning depression 12. When the disc is 85 mm in width and 56 mm in height, its maximum radius is 49.5mm. Therefore, when the noncircular compact disc 1 having positioning markers and sliding-resistance is positioned on the conveying deck 10, the disc 1 may be positioned on the first positioning depression 11 having 120 mm in diameter, while the disc 1 is positioned on top of the second positioning depression 12 having 80 mm in diameter. According to the embodiment of this invention, four positioning marks are indicated on the upper surface of the disc 1 so as to position the center of the disc 1 at the center of the positioning depressions of the deck 10 when the disc 1 is placed on the deck 10. In more detail, the four positioning marks are marked on the four positions at which the exterior contour 14 of the positioning depression 12 meets the long sides of the disc 1 while the center of the disc 1 is positioned at the center of the positioning depression of the deck 10. Although the positioning marks are shown as small triangles, the shape of the four marks is not limited to the triangle. The four marks may be changed according to the technique of printing or other application. The four marks may be carved notches. Additionally, the number of marks is not fixed at four, but may be no less than two. When a user positions the disc 1 on the deck 10 in such a manner that the ends of the four marks of the disc 1 are on the exterior contour 14 of the second depression, the center of the disc 1 is automatically set at the center of the positioning depressions of the deck 10. When the disc 1 is positioned on the deck 10, the center of the disc 1 may deviate from the center of the positioning depressions of the deck 10, since the conventional disc conveying deck 10 is designed to allow for deviation to some degree, it does not matter that the center of the disc 1 deviates from the center of the positioning depressions of the deck 10 within an allowed degree during the positioning of the disc 1. In Fig. 4a, the noncircular compact disc with positioning markers and sliding-resistance, provided with a longitudinal rectangular-shaped sliding- resistance means, according to an embodiment of the invention, is illustrated. In Fig. 4b, the noncircular compact disc with positioning markers and sliding- resistance, provided with a circular sliding- resistance means, according to another embodiment of the invention, is illustrated. A sliding-resistance means is provided on the bottom surface of the disc 1, the sliding-resistance means being made of a sliding-resistant material, thus having a large coefficient of friction and preventing the disc from sliding. As shown in Figs. 4a and 4b, the sliding- resistance means 5 can be formed within the area free from data 15. The data-free area effective for placing sliding-resistance material is the area outside the exterior contours 14 of the second positioning depressions 12. In Figs. 4a and 4b, the areas 15, on which slant lines are drawn, are the areas inside the exterior contours 14 of the second positioning depressions 12 or the areas on which data are allowed to be recorded. In the embodiment shown in Fig. 4a, the sliding- resistance means 5 is in the form of two spaced longitudinal rectangles individually formed along the short ends of the disc 1, while in the embodiment shown in Fig. 4b, the sliding-resistance means 5 is in the form of four circles individually formed at a corner portion. The sliding-resistance means 5 is made of a sliding-resistant material, with the sliding-resistant material having the coefficient of friction sufficient to prevent the disc from sliding on the deck 10. Examples of the sliding-resistant materials are materials which solidify in the form of thin films after being coated in a liquid phase and have large coefficients of friction. Such materials are rubber, urethane, silicon, etc. When such materials are employed as the sliding-resistant materials, the sliding-resistance means is allowed to be formed in an arbitrary shape because the materials may be coated in liquid phase, and the disc is allowed to be easily dealt with because the materials solidify in the form of thin films. On the other hand, rubber film, urethane film, silicon film, sand paper, etc. already solidified may be employed as sliding-resistant materials. Further, as the sliding-resistance means, a plurality of prominences and depressions may be integrally formed on the bottom surface of the disc 1 using a metal mould. When the compact disc 1 having positioning markers and sliding-resistance, provided with such a sliding-resistance means, is positioned on the first positioning depression 11 of the conveying deck 10, the position of the disc 1 is not changed despite retraction of the deck into a compact disc drive and any reasonable degree of external impact. No occurrence of change is due to the friction between the sliding-resistance means 5 and the deck 10. As described above, a noncircular-shaped compact disc having positioning markers and sliding-resistance of the present invention allows precise and easy positioning of the disc on the disc conveying deck because positioning marks are indicated on the upper surface of the disc. The noncircular-shaped compact disc 1 having positioning markers and sliding-resistance of the present invention prevents unexpected movement of the disc on the deck despite retraction of the deck into a compact disc drive and any reasonable degree of external impact because the sliding-resistance means is provided on the bottom surface of the disc. By these means, the noncircular-shaped compact disc can be mounted in any computer disc drive. Industrial Applicability According to noncircular-shaped compact disc having positioning markers and sliding-resistance of this invention, in case that the structure of a disc conveying deck is not changed or an auxiliary device is not provided to the deck, the deck may be loaded with noncircular-shaped compact disc having positioning markers and sliding-resistance by means of an automatic loading method or a manual loading method. Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims: CLATMS 1. A noncircular-shaped compact disc having positioning markers and sliding-resistance, comprised of: two or more positioning marks formed on positions, at which an exterior contour of an inside positioning depression of a disc conveying deck meets the long sides of the disc while the center of the disc is positioned at the center of said positioning depression; and sliding-resistance means provided within a data- free area of a bottom surface of the disc, and made of a sliding-resistance material having a large coefficient of friction, said means being adapted for preventing the disc from unexpectedly moving on the deck. 2. The disc according to Claim 1, wherein said sliding-resistance means is comprised of a thin film made of rubber, urethane or silicon. 3. The disc according to Claim 1, wherein said sliding-resistance means are comprised of a plurality of prominences and depressions integrally formed on the disc. 4. The disc according to any one of Claims 1 to 3, wherein said sliding-resistance means has a longitudinal rectangular shape. 5. The disc according to any one of Claims 1 to 3, wherein said sliding-resistance means has a circular shape. 6. The disc according to any one of Claims 1 to 3, wherein said noncircular-shaped compact disc having positioning markers and sliding-resistance has a rectangular credit card shape. 7. The disc according to any one of Claims 1 to 3, wherein said noncircular-shaped compact disc having positioning markers and sliding-resistance is any one of a CD-ROM capable of storing read-only data, a CD-R capable of writing data once, and a CD-RW capable of reading, writing and erasing data many times.

Inventors: LEE WON RAE, LEE, WON, RAE
Applicants: LEE WON RAE, LEE, WON, RAE
Application year: 1999
Main classification: G11B7
IPC codes: G11B7, G11B17, G11B23