JPH0778407A - Disk record and disk identification method - Google Patents

Abstract

PURPOSE:To identify a true duplicating disk from an illegal duplicating disk and to prohibit the reproduction of data of the illegal duplicating disk. CONSTITUTION:By a control circuit 2, with a disk loaded and a power turned on, a pickup motor 5 is driven and a pickup 1 is moved from its initial position A to a further internal prescribed position B; and in a state where a disk motor 4 is rotated at a prescribed angular velocity by a disk servo circuit 3, the reproducing output of the pickup 1 is inputted in a pattern detecting circuit 6. If a pattern detection output is generated within a fixed period, a reproduction is allowed in an information recording area; and if the detection output is not generated, the reproduction is prohibited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc record and a disc identifying method for identifying an illegally duplicated disc.

[0002]

2. Description of the Related Art Optical discs such as compact discs are
A pattern such as visually recognizable characters is formed further inside the information recording area. This pattern makes it possible to visually identify the pattern by making the pit cycle of the ground portion different from the pit cycle of the pattern portion. This pattern is usually used for production process control and the like, and is not a character that has a special meaning to general consumers.

On the other hand, recently, as optical discs, not only music but also CDROM discs for recording various high-value-added data have come into circulation, and discs illegally copied due to their high value-added are illegally marketed. , There is a piracy issue.

[0004]

Therefore, in order to eliminate such an illegally duplicated disk, it is necessary to identify the illegally duplicated disk by a simple method.

[0005]

According to the present invention, a pattern such as a special trademark is recorded on the inner circumference of a disc by the method described above, and the pattern or a special pit string in the pattern is detected before the reproduction to obtain a standard. By comparing with the pattern,
The reproduction of the information track is controlled according to the comparison result.

[0006]

According to the present invention, when a pattern other than the predetermined pattern or a pit row other than the special pit row is formed on the inner circumference of the disk, an illegally duplicated disk is detected by identifying the pattern or the pit row. To be done.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a disc player will be described below. First, FIG. 2 is a diagram schematically showing a pattern formed in an arc shape inside the information recording area of the disc of this embodiment. (Although the pattern is actually formed in an arc shape, it is expressed linearly for convenience of illustration.) This pattern is composed of short-period pits for the ground portion and long-period pits for the pattern portion. However, the relationship may be reversed. In addition, in order to further improve the identification accuracy, the period of the pattern portion is not made common, and horizontal stripes are formed in the pattern portion by gradually changing according to the disc radius, or even if the pit length is changed for each character. good. It should be noted that forming the pattern on the inner circumference is a well-known configuration, apart from the pit cycle and the like.
Also, the pattern to be formed may be characters or marks,
Registered trademark image is desirable.

FIG. 1 shows a circuit block diagram of this embodiment. As is clear from this figure, the pickup 1 is initially located at the initial position A of the lead-in area on the inner circumference of the information recording area of the disc D. Therefore, when the disc is mounted and the power is turned on, the control circuit 2 operates to first activate the disc servo to rotate the disc motor 4. Further, the control circuit 2 activates the pickup motor 5, the pickup 1 moves to a predetermined position B (position bb 'in FIG. 2) of the above-mentioned pattern portion, and the completion of the movement is detected by the sensor in the pickup motor. Then, the pickup motor 5 is stopped. Further, the disk D is driven at a constant angular velocity by the disk servo circuit 3 in the activated state, and the control circuit 2 inputs the output of the disk servo 3 and detects that it has reached the rated speed rotation state.

In this state, the pattern detection circuit 6 for inputting the pickup output determines whether or not a visual pattern is recorded at a predetermined pit cycle and forms a predetermined reproduction pattern waveform at the reproduction position B in the circumferential direction. Identify. Figure 3
FIG. 3 is a circuit block diagram showing a specific configuration of this pattern detection circuit 6. The pit cycle discriminating circuit 61 which inputs the reproduction output counts the cycle of the reproduction output with a fixed clock, detects that the pit cycle of the pattern portion is a predetermined cycle, and generates an output corresponding to the pattern portion. Therefore, even if the patterns are visually common, no detection output is generated for patterns having different pit periods. The initial position detection circuit 62 which receives this discrimination output as an input is a circuit which enables retriggerable mono-multi, and is configured to generate an output in synchronization with the start of reproduction of the pattern. The output of this detection circuit activates the standard pattern generator 63 and supplies the standard waveform corresponding to the character string portion to the comparison circuit 64. The comparison circuit 64 compares the standard waveform with the discrimination output, generates a coincidence output when the waveforms coincide with each other, and supplies the coincidence output to the control circuit 2 as a pattern detection output. Incidentally, the comparison of pattern detection is not limited to one place as described above, but the pickup may be moved stepwise and executed at a plurality of places. In that case, naturally, a plurality of corresponding standard waveforms are prepared. There is a need to. Furthermore, when the pit cycle of the pattern portion is changed stepwise in the radial direction, it is necessary to prepare a plurality of judgment cycles of the pit judgment circuit 61 and switch them according to the reproduction position.

The control circuit 2 moves the pickup motor 5 to the initial position A of the information recording area when the pattern detection output is input within a certain period after starting the identification operation, and then the information is recorded. Start playing the recording area. Therefore, the reproduction output is decoded and output by the decoder 7. At the same time, the PLL circuit 8 which inputs the reproduced clock signal output from the decoder inputs the output to the disk servo circuit 3. Initial position A of pickup 1
After returning to, the control circuit 5 drives the disk motor 4 with an output obtained by phase comparison of the reference pulse and the PLL output so as to control the disk servo circuit 3 at a constant linear velocity. Therefore,
After that, the disc player returns to the normal operating state and reproduces the recorded information on the disc.

On the other hand, when the pattern detection output is not input within the above-mentioned fixed period, the control circuit 2 considers the disk as an illegal duplication disk, and drives the pickup motor 5 to move the pickup 1 to the initial position A. When the disk is restored and the drive of the data 4 is stopped,
Prohibits playback of the information recording area. Although the above-mentioned disc player performs both the pit period identification and the pattern identification, only the pit period in the pattern may be identified. It goes without saying that such a configuration is also included in the present invention. Furthermore, if characters are formed in a pit string in which the pit period is complicatedly changed for each character and in the radial direction, illegal imitation can be made even more difficult, and even if the player checks all patterns. It is also possible to check only a specific part. Furthermore, the inner peripheral portion of the disk may not have a pit row formed in the ground portion.

Therefore, it is possible to form a character pattern by continuously and repeatedly recording a predetermined identification pit pattern sequence in which the pit length and the pit period are not constant and to form no pit in the remaining ground portion. It is possible. When discriminating such a disc, only the pattern discriminating means in FIG. 3 needs to be changed. FIG. 4 shows a pattern identifying means for identifying such a disc a plurality of times, and the reproduction output is input to the shift register 65 by a fixed clock. The output of the shift register 65 is input to the coincidence detecting means and compared with the identification pit pattern. This identification pit pattern has a waveform as shown in the figure, for example, and is stored in advance in the identification pit pattern generating means 67. The coincidence detecting means 66 detects the identification pit pattern and the shift register 6.
The output of 5 is compared every time a fixed clock is generated. As a result, a coincident output is generated when the identification pit pattern is reproduced. This coincidence output is input to the continuous detection means 68 at the generation cycle of the identification pit pattern. The continuous detection circuit generates a pattern detection output when the coincidence output occurs four times in the generation cycle of the identification pit pattern. Therefore, even if the coincidence detection circuit erroneously produces the coincidence output only once, the pattern detection output is not produced, and the malfunction can be prevented. Needless to say, the entire pattern detection circuit may be composed of software of a microcomputer.

The pattern identifying means described above only identifies at a specific radial position, and the identification pit pattern string to be recorded on the disc is formed only in a predetermined radial range, and the remaining character patterns are constant. It does not matter if it is used as a periodic pit pattern. In that case, the disc is one in which arc-shaped lines are visually formed in the character pattern.

[0014]

As described above, according to the present invention, a disc in which the pattern on the inner peripheral side of the disc is not formed with a predetermined pit period and a predetermined shape is identified by the identification circuit of the present invention, and the information recording area is identified. Since the reproduction of is prohibited, the use of illegal duplicated discs can be restricted, which can contribute to copyright protection.

[Brief description of drawings]

FIG. 1 is a block diagram of a main circuit of a disc player showing an embodiment of the present invention.

FIG. 2 is a schematic explanatory view of a pattern formed on the inner circumference of the disc.

3 is a specific circuit block diagram of the pattern detection circuit in FIG.

4 is another specific circuit block diagram of the pattern detection circuit in FIG.

[Explanation of symbols]

 6 Pattern detection circuit 2 Control circuit 1 Pickup

Claims (4)

[Claims] 1. A visually recognizable character or graphic pattern is formed in an arc shape by changing only the character portion or the graphic portion of the pit length of a continuously formed pit row on the inner peripheral side of an information recording area of a disc. In order to reproduce the optical disc record, the pickup is moved to the radial position where the character or graphic pattern is formed in the initial state of reproduction and the disc motor is rotated at a predetermined speed, and reproduction is executed. Then, the reproduction signal waveform formed by the character or graphic pattern is compared with a standard waveform stored in advance, and reproduction of the information recording area is controlled based on the comparison result. Identification method. 2. An optical disk record formed by forming a character or graphic pattern which can be visually identified by an identification pit pattern array in an arc shape on the inner peripheral side of the information recording area of the disk in an initial reproduction state. Then, while the disc motor is rotating at a predetermined speed, the pickup is moved to the radial position where the character or graphic pattern is formed, and reproduction is executed.
A disc identifying method for a disc player, wherein the special pit string is identified, and reproduction of the information recording area is controlled based on the identification result. 3. A character or figure pattern that can be visually identified by pits is formed in an arc shape on the inner peripheral side of the information recording area of the disc, and a special pit row is formed only in a specific range in the radial direction of the character or figure pattern. An optical disc record formed by forming. 4. A character or figure pattern that can be visually identified by pits is formed in an arc shape on the inner peripheral side of the information recording area of the disc, and an identification pit pattern is formed only in a specific range in the radial direction of the character or figure pattern. In order to reproduce an optical disk record formed by forming rows, in the initial reproduction state, the disk motor is rotated at a predetermined speed, and the pickup is moved to a specific range of the radial position where the character or figure pattern is formed. The disc identification method of the disc player, characterized in that the reproduction is performed, the specific range of the pattern is reproduced to identify the special pit row, and the reproduction of the information recording area is controlled based on the identification result. .