DESCRIPTION

OPTICAL RECORDING MEDIUM, OPTICAL

RECORDING DEVICE, OPTICAL RECORDING SYSTEM, AND DETERMINATION METHOD

TECHNICAL FIELD

This invention relates to an optical recording medium, an optical recording device, an optical recording system, and a determination method. More particularly, this invention relates to an optical recording medium which is appropriate for recording a content encoded by the CSS (content scrambling system), an optical recording device which uses the optical recording medium as an object medium, an optical recording system in which the optical recording device is provided, and a determination method which determines whether an optical recording medium supports recording of a content encoded by the CSS.

BACKGROUND ART

A video content, such as a movie, is encoded by the encryption system called CSS (content scrambling system) . DVD-ROM (digital

versatile disc-ROM) is marketed with the key information for descrambling the scrambled codes being recorded. A playback device for reproducing the video content is configured to descramble the scrambled video content based on the key information recorded on the DVD-ROM. For example, see Japanese Laid-Open Patent ■ Application No. 11-176090. In this manner, the copyright of video content is protected. The key information is stored in a predetermined region arranged on the inner-track side of DVD- ROM.

Recordable DVDs currently marketed are provided so that the key information cannot be recorded thereon. For example, DVD-system optical recording media, such as DVD-R (DVD- recordable) and DVD-RW (DVD-rewritable), are provided such that emboss processing is performed in the region of the optical recording medium which corresponds to the predetermined region of the DVD-ROM mentioned above. DVD+system optical discs, such as DVD+R (DVD+recordable) and DVD+RW ( DVD+rewritable ) , are provided such that the region corresponding to the predetermined region of the DVD-ROM

mentioned above is a write protected region where writing cannot be performed by the existing recording devices or recording systems. For example, see Standard ECMA-349 "Data Interchange on 120mm and 80mm Optical Disc Using +R Format - Capacity: 4.7 and 1.46 Gbytes per Side", 1st edition, December 2003; and Standard ECMA-337 "Data Interchange on 120mm and 80mm Optical Disc Using +RW Format - Capacity: 4.7 and 1.46 Gbytes per Side", 2nd edition, December 2003.

In recent years, with the spread of the Internet, downloading a video content through the Internet is conceivable as one of the purchase styles of video content. However, as mentioned above, recording the key information in the predetermined region of the medium is impossible even if it is a recordable DVD. Therefore, it is impossible to record the downloaded encoded video content on a DVD in a reproducible state.

DISCLOSURE OF THE INVENTION

According to one aspect of the invention, there is provided an improved optical recording

above-described problems are eliminated.

According to one aspect of the invention there is provided an optical recording medium on which the content encoded by the CSS is recordable in a reproducible state.

According to one aspect of the invention there is provided an optical recording device and optical recording system which is appropriate for recording the encoded content by the CSS on the optical recording medium of the invention in a reproducible state.

According to one aspect of the invention there is provided a determination method which is adapted for easily determining whether an optical recording medium supports recording of the content encoded by the CSS.

In an embodiment of the invention which solves or reduces one or more of the above- mentioned problems, there is provided a recordable optical recording medium having tracks formed in a spiral shape or concentric shape and including a recording region having a management information region and a data region, wherein the optical recording medium is arranged so that key information of a content encoded by

a content scrambling system CSS is recordable in the management information region.

By using the above-mentioned optical recording medium, the key information of the encoded content by the CSS is recordable in the management information region of the medium. Consequently, it is possible to record the encoded content by the CSS in a reproducible state . In an embodiment of the invention which solves or reduces one or more of the above- mentioned problems, there is provided an optical recording device which uses the above-mentioned optical recording medium as an object medium, the optical recording device comprising: a determination unit configured to determine whether discriminating information, indicating that key information of a content encoded by a content scrambling system CSS is recordable, is recorded on an optical recording medium; and a recording unit configured to record the encoded content by the CSS and the key information in a data region and a management information region of the optical recording medium, respectively, when it is determined by the determination unit

that the discriminating information is recorded on the optical recording medium.

By using the above-mentioned optical recording device, it is determined by the determination unit whether the discriminating information, indicating that key information of the encoded content by the CSS is recordable, is recorded on the optical recording medium. When the discriminating information is recorded on the optical recording medium, the recording unit records the encoded content by the CSS in the data region of the optical recording medium and records the key information in the management information region of the optical recording medium. Thus, the encoded content by the CSS and the key information thereof can be recorded on the optical recording medium. Consequently, it is possible to record the encoded content by the CSS on the optical recording medium in a reproducible state.

In an embodiment of the invention which solves or reduces one or more of the above- mentioned problems, there is provided a determination method which determines whether an optical recording medium supports recording of a

content encoded by a content scrambling system CSS, the determination method comprising: determining whether discriminating information, indicating that key information of the encoded content by the CSS is recordable, is recorded on an optical recording medium; and recording the encoded content by the CSS and the key information in a data region and a management information region of the optical recording medium, respectively, when it is determined in the determining step that the discriminating information is recorded on the optical recording medium .

By using the above-mentioned determination method, it is determined whether the discriminating information is recorded on the optical recording medium. When the discriminating information is recorded on the optical recording medium, it is determined that the optical recording medium supports recording of the encoded content by the CSS. Accordingly, it is possible to easily determine whether an optical recording medium supports recording of the encoded content by the CSS.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention will be apparent from the following detailed description when reading in conjunction with the accompanying drawings.

FIG. 1 is a cross -sectional view showing the structure of an optical disc which is an optical recording medium in an embodiment of the invention . FIG. 2 is a diagram for explaining tracks in the optical disc of FIG. 1.

FIG. 3 is a diagram for explaining wobbling of tracks in the optical disc of FIG. 1.

FIG. 4 is a diagram for explaining the composition of an information frame.

FIG. 5A and FIG. 5B are diagrams for explaining a wobbling shape of an ADIP (address in pregroove) information region.

FIG. 6A and FIG. 6B are diagrams for explaining a wobbling shape of a sync information region.

FIG. 7 is a diagram for explaining an ADIP (address in pregroove) word.

FIG. 8 is a diagram for explaining physical format information.

FIG. 9 is a block diagram showing the composition of a personal computer which is an optical recording system in an embodiment of this invention. FIG. 10 is a block diagram showing the composition of an optical disc device shown in FIG. 9 which is an optical recording device in an embodiment of the invention.

FIG. 11 is a flowchart for explaining operation of the optical disc device of FIG. 10.

BEST MODE FOR CARRYING OUT THE INVENTION

A description will be given of embodiments of the invention with reference to the accompanying drawings.

FIG. 1 shows the structure of an optical disc 15 which is an optical recording medium in an embodiment of the invention.

As shown in FIG. 1, a groove G which is a guide groove in a spiral shape is formed in a recording layer of the optical disc 15. Generally, when an optical disc is viewed from the direction of incidence of laser light, the convex-form portion is called a groove G, and the concave-form portion is called a land L. In

this embodiment, the groove G constitutes a track for recording data, and data is recorded on the groove G.

As shown in FIG. 2 as a typical example, each track is divided into a plurality of regions including a lead-in region (Lead-in Zone), a data region (Data Zone), and a lead-out region (Lead-out Zone) in the direction from the inner track side to the outer track side. The lead-in region is a management information region in which management information or the like is stored. The data region is a region in which user data is stored. The lead-out region is a region in which information for pointing to the position of the end of data is stored. In FIG. 2, for the sake of convenience, it is assumed that a track is formed in the shape of a straight line, the left-hand side of the drawing is the inner track side of the optical disc 15, and the right-hand side of the drawing is the outer track side of the optical disc 15.

As shown in FIG. 3 as an example, the tracks are formed in a wobbling shape with respect to the track center. A track pitch in

— i i _

this case is equal to 0.74 micrometers.

The wobbling shape of the track is determined by an ADIP (address in pregroove) unit and a carrier. The ADIP unit contains various kinds of information. The carrier is used for generating a reference clock signal. In the following embodiment, the base unit consisting of an ADIP unit and a carrier region is called an information frame. As shown in FIG. 4 as an example, the size of one information frame is represented by 93 wobbles (the wobble numbers 0-92), supposing that one cycle of the carrier (which is called a wobble cycle) is represented by one wobble. In the example of FIG. 4, the wobble numbers 0-7 constitute the ADIP unit, and the wobble numbers 8-92 constitute the carrier region.

The ADIP unit includes a region (sync information region) of the wobble numbers 0-3, and a region (ADIP information region) of the wobble numbers 4-7. Each of the above-mentioned information regions is subjected to the phase modulation (or phase shift keying PSK) respectively. In the ADIP information region, four

wobbles express 1 bit data. As shown in FIG. 5A, when the bit data is "0", the two front-end wobbles are formed to have the phase that is the same as that of the carrier region while the two back-end wobbles are formed to have the phase that is opposite to that of the carrier region.

On the other hand, as shown in FIG. 5B, when the bit data is "1", the two front-end wobbles are formed to have the phase that is opposite to that of the carrier region while the two back-end wobbles are formed to have the phase that is the same as that of the carrier region .

As shown in FIG. 6A, when the ADIP information region in the following information frame indicates the start bit of data, the sync information region indicates a word sync signal, i.e., all the four wobbles of the sync information region are formed to have the phase that is opposite to that of the carrier region.

As shown in FIG. 6B, when bit data are contained in the ADIP information region, the sync information region indicates a bit sync signal, i.e., the one front-end wobble of the sync information region is formed to have the

phase that is opposite to that of the carrier region while the three remaining wobbles of the sync information region are formed to have the phase that is the same that of the carrier region.

As shown in FIG. 7, one ADIP word is represented by 52 information frames. The ADIP unit in the lead-in region contains physical format information. The physical format information in this embodiment is the same as set forth by DVD+R standard requirement (see Standard ECMA-349) or DVD+RW standard requirement (see Standard ECMA-337) except for only the byte 16 of the physical format information being changed.

Specifically, as shown in FIG. 8, the code at the byte 16 of the physical format information in this embodiment is defined as being a recording permission code in a key information region, and "01h" in hexadecimal notation is stored therein.

In the following, DVD+R standard requirement and DVD+RW standard requirement will be collectively called "DVD+R/RW standard requirement" for the sake of convenience.

According to the DVD+R/RW standard requirement, the byte 16 of the physical format information is not in use (reserved) and the code at the byte 16 is set to "0Oh". In this embodiment, the non-used

(reserved) portion of the lead-in region in conformity with the DVD+R/RW standard requirement is used as a key information region. The ADIP unit in the data region contains address information.

As explained above, the optical disc 15 in this embodiment is a recordable optical disc which is in conformity with the DVD+R/RW- standard requirement except for the byte 16 of the physical format information.

The recording permission code in the key information region is stored in the physical format information which specifies the wobbling shape of tracks in the optical disc 15 of this embodiment, which makes it possible to record the key information of the encoded content by the CSS thereon. Accordingly, it is possible to record the encoded content by the CSS on the optical disc 15 of this embodiment in a reproducible state.

In the above-mentioned embodiment, the case where the recording permission code in the key information region is stored in the byte 16 of the physical format information has been described. Alternatively, the recording permission code in the key information region may be stored in the byte 17 of the physical format information, for example. According to the DVD+R/RW standard requirement, the byte 17 of the physical format information is a region in which "Disc Application Code" is stored. In such alternative embodiment, the optical disc is no longer compatible with the existing optical disc devices . In the above-mentioned embodiment, the case where the optical disc 15 has one recording layer has been described. This invention is not limited to this embodiment. Alternatively, the optical disc 15 of the invention may be configured to have two or more recording layers.

FIG. 9 shows the composition of a personal computer (PC) 10 which is an optical recording system in an embodiment of the invention . As shown in FIG. 9, the personal

computer 10 is provided to include a main controller 92, an optical disc device 20, a hard disk drive (HDD) 94, an input device 95, a display device 96, a drive interface device 97, and a network interface device 98. The optical disc device 20 is an optical recording device in an embodiment of the invention.

The main controller 92 includes a CPU 92a, a ROM 92b, and a RAM 92c. The CPU 92a performs recording processing (which will be mentioned later) while controlling the entire personal computer 10 based on the program stored in the ROM 92b and the RAM 92c.

The HDD 94 includes a hard disk 94a and a driving device 94b for driving the hard disk 94a. Various programs described in codes that can be deciphered by the CPU 92a of the main controller 92 are recorded on the hard disk 94a. The programs recorded on the hard disk 94a are loaded to the RAM 92c of the main controller 92 if needed.

The display device 96 is provided with the display (not shown) which is made of any of a cathode-ray tube (CRT), a liquid crystal display (LCD), a plasma-display panel (PDP), etc.

The display device 96 displays a variety of information in accordance with the instructions from the main controller 92.

The input device 95 is provided to include at least one input medium (not shown) among a keyboard, a mouse, a tablet, a light pen, a touch panel, etc. The input device 95 notifies a variety of information inputted by the user, to the main controller 92. The information from the input medium may be inputted to the personal computer 10 by using a wireless system.

Alternatively, the display device 96 and the input device 95 may be arranged as an integral display/input device, for example, an LCD with a touch panel.

The drive interface device 97 provides a bidirectional interface between the main controller 92 and the optical disc device 20 or the HDD 94. The drive interface device 97 is in conformity with the standard interfaces, such as ATAPI (AT Attachment Packet Interface) , SCSI (Small Computer System Interface), and USB (Universal Serial Bus) . The network control unit 98 controls the

bidirectional communication using the public telephone network. The network interface device 98 serves to establish a connection between the personal computer 10 and the Internet. The optical disc device 20 is arranged to record information on the optical disc in accordance with the instructions from the main controller 92.

As shown in FIG. 10, the optical disc device 20 is provided with the following elements: a spindle motor 22 for rotating an optical disc set in the optical disc device, an optical pickup device 23, a seek motor 21 for actuating the optical pickup device 23 in a radial direction of the optical disc, a laser control circuit 24, an encoder 25, a drive control circuit 26, a playback signal processing circuit 28, a buffer RAM 34, a buffer manager 37, an interface device 38, a flash memory 39, a CPU 40, and a RAM 41. The arrow in FIG. 10 indicates only the flow of a typical signal or typical information, and does not show all the connecting relations between the elements of the optical disc device 20. Suppose that the optical disc device 20

supports recording of the optical disc 15. The optical pickup device 23 is arranged to focus a laser beam onto the recording layer of the optical disc 15 and to receive a reflected laser beam from the recording layer.

The optical pickup device 23 includes a semiconductor laser which emits a laser beam of a wavelength corresponding to the optical disc 15, an objective lens which focuses the laser beam emitted by the semiconductor laser onto the recording layer of the optical disc 15, a photodetector which receives a returned laser beam reflected by the recording layer, and a drive system (a focusing actuator and a tracking actuator which are not shown) for actuating the objective lens, etc. The photodetector includes a plurality of light-receiving elements (or light receiving regions) and outputs a signal (photoelectric conversion signal) proportional to the intensity of the laser beam received by the light-receiving elements (or the light- receiving regions), to the playback signal processing circuit 28.

The playback signal processing circuit 28 generates servo signals (a' focus error signal,

a track error signal, etc.) , a wobble signal, an RF signal, etc. based on the outputs (photoelectric conversion signals) of the photodetector . For example, refer to Japanese Laid-Open Patent Application No. 10-069646.

The servo signals generated by the playback signal processing circuit 28 are outputted to the drive control circuit 26, the CPU 40, etc. The playback signal processing circuit 28 acquires sync information, physical format information, and address information from the wobble signal.

The sync information acquired is outputted to the encoder 25 and the drive control circuit 26. The physical format information and the address information are outputted to the CPU 40.

The playback signal processing circuit 28 performs decoding processing and error detection processing to the RF signal. When an error is detected, the playback signal processing circuit 28 stores the playback data after error correction processing is performed, into the buffer RAM 34 via the buffer manager 37. The drive control circuit 26 generates a

driving signal to the tracking actuator for correcting a deviation of the objective lens in the tracking direction, based on the tracking error signal received from the playback signal processing circuit 28. The drive control circuit 26 generates a driving signal to the focusing actuator for correcting a focusing deviation of the objective lens, based on the focusing error signal received from the playback signal processing circuit 28.

The driving signals to the respective actuators generated are outputted to the optical pickup device 23. Thereby, tracking control and focus control are performed. The drive control circuit 26 generates a driving signal for driving the seek motor 21, and a driving signal for driving the spindle motor 22 in accordance with the instructions from the CPU 40. The driving signals to the respective motors are outputted to the seek motor 21 and the spindle motor 22, respectively.

The data (recording data) to be recorded on the optical disc 15, the data (playback data) being reproduced from the optical disc 15, etc. are temporarily stored in the buffer RAM 34.

The input/output of the data to/from the buffer RAM 34 is managed by the buffer manager 37.

In accordance with the instructions from the CPU 40, the encoder 25 reads out the recording data from the buffer RAM 34 through the buffer manager 37, performs modulation of data, addition of error correction codes, etc., and generates a write signal to the optical disc 15. The write signal generated is outputted to the laser control circuit 24.

The laser control circuit 24 controls the emission power of the semiconductor laser of the optical pickup device 23. For example, at the time of recording information, the driving signal to the semiconductor laser is generated by the laser control circuit 24 based on the write signal, the recording condition, the light emission characteristic of the semiconductor laser, etc. The interface device 38 provides a bidirectional communication interface with the main controller 92 through the drive interface device 97, and is in conformity with the standard interface which is the same as that of the drive interface device 97.

The various programs described in codes that can be deciphered by the CPU 40, the recording conditions including the recording power and recording strategy information, the light emission characteristic of the semiconductor laser, etc. are stored in the flash memory 39.

The CPU 40 stores the necessary data for controlling into the RAM 41 and the buffer RAM 34 while controlling the entire optical disc device 20 in accordance with the above-mentioned programs stored in the flash memory 39. Recording Processing of Video Content

Next, the recording processing of the video content encoded by the CSS (which is called "CSS encoded content") which is performed by the personal computer 10 will be explained.

Suppose that the CSS encoded content and its key information are downloaded through the Internet from the web site of the provider of the CSS encoded content, and temporarily stored in the hard disk 94a. Suppose that the optical disc 15 is set in the optical disc device 20.

(1) The CPU 92a of the main controller 92 receives a write request to the optical disc

of the CSS encoded content from a user through the input device 95. Upon receipt of the write request, the CPU 92a requests the optical disc device 20 to perform the writing of the CSS encoded content and its key information stored in the hard disk 94a.

(a) The CPU 40 of the optical disc device 20 receives the writing instruction of the CSS encoded content and its key information from the main controller 92. Upon receipt of the writing instruction, the start address of the program corresponding to the flowchart of FIG. 11 stored in the flash memory 39 is set to the program counter, and the CPU 40 starts the writing processing. The flowchart of FIG. 11 corresponds to a series of processing algorithms which are performed by the CPU 40.

(b) In step S401, the code at byte 16 in the physical format information of the optical disc is read out. The physical format information is already read at the time of setting the optical disc to the optical disc device 20 and stored into the RAM 41.

(c) In step S403, it is determined whether the code read from byte 16 in the

physical format information is equal to "Olh". Namely, it is determined whether the optical disc supports recording of CSS encoded content.

In this case, the optical disc set in the optical disc device 20 is the optical disc 15, and the code read from byte 16 of the physical format information is equal to "Olh". Thus, the result of determination at step S403 is affirmative. The control is shifted to step S405. Namely, it is determined that the optical disc set in the optical disc device supports recording of CSS encoded content.

(d) In step S405, the writing of the CSS encoded content to the data region of the optical disc is permitted. Thereby, the writing of the CSS encoded content to the data region of the optical disc is started through the encoder 25 _f the laser control circuit 24, and the optical pickup device 23. (e) In step S407, the amount of the already written data is compared with the amount of writing data requested by the main controller 92, and it is determined whether the writing of the CSS encoded content to the data region is completed.

When the writing of the CSS encoded content to the data region is not completed, the result of the determination at step S407 is negative. After passing of a predetermined time, it is determined again whether the writing of the CSS encoded content to the data region is completed .

On the other hand, when the writing of the CSS encoded content to the data region is completed, the result of the determination at step S407 is affirmative. The control is shifted to step S409.

(f) In step S409, the writing of the key- information to the lead-in region is permitted. Thereby, the writing of the lead-in information, including the key information, to the lead-in region of the optical disc is started through the encoder 25, the laser control circuit 24, and the optical pickup device 23. (g) In step S411, the CPU 40 notifies the main controller 92 that the writing of the CSS encoded content and the key information is completed normally. And the writing processing is ended. (h) When the code read from byte 16 of

the physical format ^' information is not equal to "Olh", the result of the determination in step S403 is negative. The control is shifted to step S421. (1) In step S421, the CPU 40 notifies the main controller 92 that the writing of the CSS encoded content and the key information is terminated abnormally. And the writing processing is ended. (2) When "normal end" is received from the optical disc device 20, the CPU 92a of the main controller 92 requests the HDD 94 to erase the CSS encoded content and the key information stored in the hard disk 94a. (3) The CPU 92a of the main controller

92 displays a message, indicating that recording of CSS encoded content is completed normally, on the display of the display device 96, in order to notify the user of it. And the CPU 92a requests the optical disc device 20 to eject the optical disc. The recording processing of CSS encoded content is ended.

(4) When "abnormal end" is received from the optical disc device 20, the CPU 92a of the main controller 92 displays a message indicating

that the optical disc currently set should be replaced by another optical disc on which CSS encoded content is recordable, on the display of the display device 96, in order to notify the user of it. Namely, recording of CSS encoded content and its key information on any optical disc other than the optical disc on which CSS encoded content is recordable is inhibited.

As described in the foregoing, in the personal computer 10 of this embodiment, the optical recording device is constituted by the optical disc device 20, and the processing unit is constituted by the CPU 92a and the program executed by the CPU 92a. Alternatively, a part of the processing unit or all the processing unit constituted by the program executed by the CPU 92a may be replaced by the processing using the hardware. In the optical disc device 20 of this embodiment, the recording unit is constituted by the encoder 25, the laser control circuit 24, and the optical pickup device 23, and the determination unit is constituted by the CPU 40 and the program executed by the CPU 40. Alternatively, a part of the

determination unit or all the determination unit constituted by the program executed by the CPU 40 may be replaced by the processing using the hardware . The determination method of the invention is constituted by the writing processing performed by the optical disc device 20 described above.

As described above, according to the optical disc device 20 of this embodiment, prior to recording of CSS encoded content and its key information on the optical disc, it is determined whether the recording permission code in key information region (discriminating information) , indicating that the key information of CSS encoded content is recordable, is recorded on the optical disc. When the recording permission code in key information region is recorded on the optical disc, the CSS encoded content and its key information are recorded on the optical disc. Therefore, it is possible to record the CSS encoded content and its key information on the optical disc of the invention . Accordingly, it is possible to record

the CSS encoded content on the recordable optical disc of the invention in a reproducible state. Thus, it is possible to record the downloaded CSS encoded content along with the key information on the optical disc of the invention in a reproducible state.

In the personal computer 10 of this embodiment, the optical disc device 20 is provided therein, and it is possible to record the CSS encoded content and its key information on the optical disc of the invention. Consequently, it is possible to record the CSS encoded content on the optical disc of the invention in a reproducible state. In the above-mentioned embodiment, the case where the optical recording system is constituted by a personal computer has been described. Alternatively, the optical recording system may be constituted by a DVD recorder which performs processing that is the same as the above-mentioned recording processing of the CSS encoded content.

The present invention is not limited to the above-described embodiments, and variations and modifications may be made without departing

from the scope of the present invention.

The present application is based on and claims the benefit of priority of Japanese patent application No. 2006-239953, filed on September 5, 2006, the entire contents of which are hereby incorporated by reference.