JP3062861U - High density compact disc - Google Patents

Abstract

(57) [Problem] To provide a high-density compact disc that can be adapted to current CD and VCD players. A high-density compact disc has a shape similar to a current CD. Since the length and interval between the pit and the pitch are all reduced, the storage capacity of the CD is increased to 1.2 GB (125 minutes of video data). This kind of high-density compact disc is
Compatible with D and VCD players. There is no need to redesign the hardware to play this high density compact disc.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to high density compact discs (CDs), and in particular, to optical discs having a larger storage capacity and compatible with current CD / VCD players.

[0002]

[Prior art]

 A compact disk is a commonly used storage device. In 1981, Philip and Sony defined the specifications for CD audio (compact disc digital audio) and published a book on the red cover. Due to their small size, large capacity and high fidelity, CDs have quickly replaced traditional recording devices such as plastic or bakelite records and tapes.

[0003] Philip and Sony later published yellow, orange, and white cover books that included additional specifications for CDs. The field of CDs has been extended to include CD-ROMs for storing computer data and VCDs for storing video information. Since a single CD has a storage capacity of only 650 MB, only 74 minutes of film length can be stored. Because a movie longer than 100 minutes requires more than one disc, the movie is interrupted while the user changes discs.

[0004] A storage structure for a conventional CD is shown in FIG. A plurality of circular tracks composed of pits 60 are formed on the surface of the disk. A burr 61 is formed around the pit 60 so as to be unremovable because it is limited by the production technology. In other words, since the slope of the pits 60 is gentle, the information may be obstructed when reading information from the CD. Therefore, the pitch (the radial spacing between two adjacent tracks) must be wide enough to avoid crosstalk. According to the book on the red cover, the pitch, the scanning speed, and the time unit (T) of 2CD are 1. 6 μm, 1.4 m / s and 0.327 μm.

[0005] Referring to FIG. 5, the width of the CD read head 70 is 1.7 μm. When reading a track, the read head 70 is separated from the adjacent track by 0.3 μm. FIG. 6 shows a technique for decoding the pit 60. The top row shows the binary code, the middle row shows the modulation signal, and the bottom row shows the shape of the pit 60. Each code in the top row corresponds to a time unit. The number "1" indicates the identification signal of the laser of the read head 70, the laser of the read head 70 being controlled by a code to change from one state to another, for example from an active state to an inactive state. You. The number "0" indicates an identification signal in which the laser of the read head 70 is controlled by a code to maintain one state, such as active or inactive. The change must be completed within the time unit. The slope of the pit 60 corresponds to the number "1" and determines the length of the time unit. Since the slope is gentle, the length of the unit time is defined as 0.327 μm as described above.

[0006]

[Problems to be solved by the invention]

 Wider pitches and longer time units limit the storage capacity of conventional CDs. Reducing the pitch and the unit time can greatly increase the storage capacity.

A high-density compact disk according to the present invention will mitigate and / or avoid the above problems.

It is a primary object of the present invention to provide a high density compact disc capable of storing more data than a conventional CD.

Another object of the present invention is to provide a high-density compact disc that can be adapted to current CD and VCD players.

[0010]

[Means for Solving the Problems]

 The high-density compact disk according to the present invention has a plurality of tracks composed of a plurality of pits, and the interval between two adjacent pits is smaller than 0.3 μm, and the interval between two adjacent tracks is 1. It is characterized by being smaller than 6μ.

[0011]

[Embodiment of the invention]

 Referring to FIG. 1, the high-density compact disk according to the present invention has a shape similar to that of a conventional CD, and is suitable for use in a current CD or VCD player. Table 1 compares the parameters of the conventional CD and the high-density compact disk of the present invention. Examination of this table shows that the parameters for the high-density compact disc are still within the red cover.

[0012]

Table 1 shows a comparison between the parameters of the conventional CD and the parameters of the CD of the present invention.

By improving the production technology, the slope around the pit becomes steeper than that of the conventional CD, so that the chance of interference during reading information from the CD is greatly reduced. Thus, the pitch 20 can be reduced from 1.6 μm to 1.2 μm, as shown in FIGS. In this case, the read head 30 having a width of 1.7 μm is still separated from the adjacent track by 0.1 μm when reading the track of the CD. The gap is sized appropriately to ensure that no crosstalk occurs.

In addition, the slopes of the walls of the pit 10 are also improved to steeper. The length of the time unit (T) is reduced from 0.327 μm to 0.231 μm as shown in FIG. 3 (in fact it could be in the range of 0.23-0.24 μm). . The spacing between the pits is then reduced accordingly. This means that more data can be stored for the same length.

By simultaneously reducing the pitch and length of the time unit, the storage capacity is increased to 1.2 GB (125 minutes of stored video). This is much larger than the conventional CD of 650 MB (74 minutes). Most movies are stored on a single disc, thus avoiding the need to change discs during a single movie. High density CDs are compatible with current CD and VCD players, so there is no need to redesign the player hardware.

[0016]

[Effect of the invention]

 The effects of the present invention are as follows.

Since the storage capacity of a high-density compact disc is 1.2 GB, 125 minutes of video can be completely stored on one disc. This saves the cost of additional masters and many materials.

Advantageous for the environment because consumables are saved.

The high-density CD of the present invention is compatible with current CD and VCD players and is convenient to use.

While many features and advantages of the invention have been listed in the above description, together with the structure and operation of the invention, they have been disclosed by way of example only, and are not to be construed in any way. The arrangement and the like can be changed within the principle of the invention.

[Brief description of the drawings]

FIG. 1 is a plan view showing pits of a high-density compact disk of the present invention.

FIG. 2 is a sectional view showing a read head and two tracks adjacent to the read head according to the present invention;

FIG. 3 is a diagram showing an encoding technique of the high-density compact disk of the present invention.

FIG. 4 is a plan view showing pits of a conventional compact disc.

FIG. 5 is a cross-sectional view showing a conventional compact disk read head and two tracks adjacent to the read head.

FIG. 6 is a diagram showing a conventional compact disc encoding technique.

[Explanation of symbols]

 10, 60 pits 20 pitch 30, 70 read head 61 burr

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 20, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims for utility model registration

[Correction method] Change

[Correction contents]

[Utility model registration claims]

Claims (3)

[Utility model registration claims] 1. A high-density compact disk having a plurality of tracks of a plurality of pits, wherein the distance between two adjacent pits is less than 0.3 μm and the distance between two adjacent tracks is 1. High density compact disc smaller than 6μ. 2. The high-density compact disk according to claim 1, wherein an interval in a time unit is shorter than 0.972 μm. 3. An interval between adjacent pits is 0.1 μm, and an interval between adjacent tracks is 1.0-1.4 μm.
3. The high-density compact disk according to claim 2, wherein the distance between two adjacent tracks is 1.2 tm.