Dynamic information storage or retrieval – Storage medium structure – Optical track structure
Reexamination Certificate
2000-03-17
2003-01-14
Tran, Thang V. (Department: 2653)
Dynamic information storage or retrieval
Storage medium structure
Optical track structure
C369S103000, C369S275400
Reexamination Certificate
active
06507557
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical recording medium such as an optical disc recorded with information signals and a recording method therefor, particularly, relates to an optical recording medium of which a track is formed in a main information recording area on a disc shaped substrate, wherein the track is formed in concentric circles or in a spiral composed of array of a plurality of pits, and wherein tracks adjoining to each other are arranged approximately in a same pitch.
2. Description of the Related Art
With respect to contents of information recorded in an optical recording medium such as an optical disc, there provided prior arts related to express or indicate visibly numbers or characters such as alphabet indicating a recognition number or a manufacturing sequence number, which is inherent to the optical recording medium itself, and related to display visibly a design pattern corresponding to a content of information recorded. Actually, various methods or systems have been realized.
In order to prevent information signals such as music, video image or game software recorded in an optical disc from illegal duplication by illegal operation or reverse engineering, there provided prior arts disclosing a recording method, which records information of verifying that the optical disc is a genuine optical disc or a legally manufactured optical disc, wherein the verifying information is recorded as information by a visible character or symbol or pattern, or as information, which can be read out as data by utilizing pits allocated on a track. Actually, various systems or methods of preventing information signals from illegal duplication have been utilized.
The prior art, for example, Japanese Patent Laid-open Publication No. 58-100235/1983, which is filed by the same applicant as that of the present invention, discloses that numbers or characters such as alphabet indicating a recognition number or a manufacturing sequence number inherent to an optical disc itself and patterns related to a content of recorded information are recorded outside an information recording area, which is an area for recording information originally to be recorded such as music or video images, wherein such numbers, characters or patterns are visibly displayed or indicated by a dot pattern, which is formed a same pit structure as a pit recorded with information originally to be recorded as mentioned above.
The other Japanese Patent Laid-open Publications such as No. 9-128809/1997, No. 8-83440/1996 and 9-115186/1997 provide methods of forming an inherent pattern outside an information recording area of an optical disc. According to these methods, characters and patters can be displayed or indicated visibly in a main information recording area of an optical disc. Further, it is advantageous to an optical disc that characters or patterns can be formed on the disc during the same manufacturing process of recording information such as music or video images originally and can be displayed or indicated.
However, in all these methods, an exclusive pattern for indicating characters or designs is formed by exclusive pits for displaying the characters or the designs, wherein the exclusive pits are a different format from pits for information to be recorded originally. Accordingly, such exclusive pattern for indicating characters or designs can be displayed only in a narrow area such as a blank space outside an information recording area for recording information to be recorded originally. In other words, there exist a problem that it is basically impossible to indicate characters or designs at an arbitrary location in an information recording area of an optical disc and in arbitrary dimensions.
On the other hand, Japanese Patent Laid-open Publications No. 7-130134/1995 and No. 8-273201/1996 provide a method of forming a pattern for visible characters or designs in an information recording area as well as outside an information recording area.
The Japanese Patent Laid-open Publication No. 7-130134/1995 discloses that a pattern for visible characters or designs are formed with pits in an information recording area of an optical disc in conjunction with information to be recorded originally by writing the information to be recorded originally and the pattern for characters or designs in the CAV (Constant Angular Velocity) and CLV (Constant Linear Velocity) systems respectively. According to the disclosure, a pattern for characters or designs is formed with a pit of the CLV system on an optical disc, wherein information such as music and video images are originally recorded with a pit of the CAV system. Accordingly, a pattern for visible characters or designs can be displayed in an information recording area of an optical disc in conjunction with recording information to be recorded originally.
Forming information to be recorded originally and a pattern for indicating characters or designs in one recording area by writing them with the CAV and CLV systems respectively is assigning some of pits, which are originally provided for recording information to be recorded, to the pattern for indicating characters or designs. In other words, some pits out of a total capacity of pits provided for the information to be recorded in the recording area are utilized for forming the pattern for indicating characters or designs. Accordingly, recording capacity for the information to be recorded originally in the recording area is sacrificed for the pits assigned to the pattern for indicating characters or designs.
Since a pattern for indicating characters or designs can be formed in one recording area together with information to be recorded originally by these prior arts, it is possible to display the pattern for indicating characters or designs at an arbitrary location and in arbitrary dimensions. However, there exists a problem that recording capacity for the information to be recorded originally is decreased by recording capacity for the pattern for indicating characters or designs. The problem is rather serious problem for an optical disc, which is recently required to increase its recording capacity. In other words, the prior arts mentioned above can not comply with such a requirement that information to be recorded originally such as music, video images and application software shall be recorded as much as possible in an optical recording medium like an optical disc. It is disadvantageous to the prior arts.
The other prior art related to forming a visible pattern of characters or designs in a recording area is disclosed in the Japanese Patent Laid-open Publication No. 8-273201/1996. According to the disclosure, in a dual disc such as a DVD (Digital Versatile Disc), which is a disc having a structure of sticking two transparent substrates together, a pattern for indicating characters or designs is displayed in a main information recording area of the dual disc by interposing the pattern for indicating characters or designs printed, for example, in between the two transparent substrates.
However, this prior art can not be applied to an optical disc having only one transparent substrate, that is, an optical disc having single layer of transparent substrate, because the art is applied only to an optical disc having dual layers of transparent substrate.
Japanese Patent Laid-open Publications No. 8-212560/1996 and No. 61-123026/1986 provide another method of writing information for identifying an optical disc whether it is a genuine or fake as a symbol or cipher on a data array or signal not as a visible pattern. Such symbol or cipher can be identified as data and further the information for identification can be protected from duplicating illegally by the method. Therefore, it is possible to identify whether the optical disc is a genuine or fake more accurately and also it prevents an optical disc from illegal duplication, and the illegally duplicated optical disc can be securely identified.
If the art is practiced, however, it causes a problem that an exclusive appara
Ohno Hirotoshi
Tsuji Fumitaka
Connolly Bove & Lodge & Hutz LLP
Tran Thang V.
Victor Company of Japan Ltd.
Vuong Bach
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