WO2008029590A1

WO2008029590A1 - Optical recording medium, optical recorder, optical recording system, determination method, and recording method

Info

Publication number: WO2008029590A1
Application number: PCT/JP2007/065682
Authority: WO
Inventors: Masaetsu Takahashi; Susumu Katagiri
Original assignee: Ricoh Company, Ltd.
Priority date: 2006-09-05
Filing date: 2007-08-03
Publication date: 2008-03-13
Also published as: JP2008065873A; TW200822090A

Abstract

An optical recording medium for recording having one of a spiral track and concentric tracks formed thereon is disclosed. The optical recording medium has a recording area including a management information area and a data area. Content encrypted with a Content Scrambling System (CSS) is recordable in the data area. Key information of the CSS- encrypted content is recordable in the management information area.

Description

DESCRIPTION

OPTICAL RECORDING MEDIUM, OPTICAL RECORDER, OPTICAL RECORDING SYSTEM, DETERMINATION METHOD, AND RECORDING METHOD

TECHNICAL FIELD

The present invention relates generally to optical recording media, optical recorders, optical recording systems, determination methods, and recording methods, and more particularly to an optical recording medium suitable for recording content encrypted with the Content Scrambling System (CSS) , an optical recorder for the optical recording medium, an optical recording system including the optical recorder, a method of determining whether an optical recording medium is suitable for recording CSS-encrypted content, and a method of recording CSS- encrypted content and its key information on an optical recording medium.

BACKGROUND ART

Video content such as a movie is encrypted with an encryption system called the Content Scrambling System (CSS), and is recorded on a DVD-ROM (digital versatile disc-ROM) together with key information to be commercially available. A playback unit for playing back video content descrambles the video content based on the key information recorded in the DVD-ROM. (See, for example, Patent Document 1 listed below.) The copyright of the video content is thus protected. The key information is contained in a specific area provided on the inner (center) side of the DVD-ROM. The key information cannot be recorded on currently commercially-available DVDs for recording. For example, an area corresponding to the above- described specific area of the DVD-ROM is embossed in DVD- optical recording media such as a DVD-R (DVD- recordable) and a DVD-RW (DVD-rewritable) . Further, recorders or recording systems cannot perform recording on an area corresponding to the above- described specific area of the DVD-ROM in DVD+ optical disks such as a DVD+R ( DVD+recordable) and a DVD+RW (DVD+rewritable) (hereinafter also referred to as "DVD+R/RW" for convenience of description) . (See, for example, Non-Patent Document 1 and Non-Patent Document 2 listed below.)

[Patent Document 1] Japanese Laid-Open Patent Application No. 11-176090

[Non-Patent Document 1] Standard ECMA-349, "Data Interchange on 120 mm and 80 mm Optical Disk using +R Format - Capacity: 4.7 and 1.46 Gbytes per Side," 1^st Edition, December 2003

[Non-Patent Document 2] Standard ECMA-337, "Data Interchange on 120 mm and 80 mm Optical Disk using +RW Format - Capacity: 4.7 and 1.46 Gbytes per Side,'' 2^nd Edition, December 2003

In these years, as the Internet becomes popular, downloading video content through the Internet has been devised as one type of purchase of video content. As described above, however, since the key information cannot be recorded in a predetermined area of even a DVD for recording, the downloaded encrypted video content cannot be recorded on DVDs in a reproducible manner.

DISCLOSURE OF THE INVENTION

Embodiments of the present invention may solve the above-described problem.

According to one embodiment of the present invention, there is provided an optical recording medium (for recording) in which the above-described problem may be solved.

According to one embodiment of the present invention, there is provided an optical recording medium (for recording) on which CSS-encrypted content can be recorded in a reproducible manner.

According to one embodiment of the present invention, there are provided an optical recorder and optical recording system suitable for recording CSS- encrypted content in a reproducible manner. According to one embodiment of the present invention, there is provided a determination method that can easily determine whether an optical recording medium supports recording CSS-encrypted content . According to one embodiment of the present invention, there is provided a method of recording CSS-encrypted content on the above-described optical recording medium (for recording) of the present invention in a reproducible manner. According to one embodiment of the present invention, there is provided a computer-readable recording medium tangibly embodying a program executed by a control computer of an optical recorder and enabling CSS-encrypted content to be recorded on the above-described optical recording medium (for recording) of the present invention in a reproducible manner .

According to one aspect of the present invention, there is provided an optical recording medium for recording having one of a spiral track and concentric tracks formed thereon, the optical recording medium having a recording area including a management information area and a data area, wherein content encrypted with the Content Scrambling System (CSS) is recordable in the data area, and key information of the CSS-encrypted content is recordable in the management information area.

According to this optical recording medium, it is possible to record the key information of CSS- encrypted content in the management information area, and to record only CSS-encrypted content in the data area. Accordingly, it is possible to record CSS- encrypted content in a reproducible manner.

According to one aspect of the present invention, there is provided an optical recorder for the optical recording medium of the present invention, the optical recorder including a first determination part configured to determine whether determination information showing that only the CSS-encrypted content is recordable is recorded in the optical recording medium; a recording part configured to record the CSS-encrypted content and the key information thereof in the data area and the management information area, respectively, of the optical recording medium in response to the first determination part determining that the determination information is recorded in the optical recording medium; a second determination part configured to determine whether the wobble of one of a spiral track and concentric tracks has a part ^'thereof out of compliance with one of the DVD+R standard and the DVD+RW standard in response to the first determination part determining that the determination information is not contained in the optical recording medium; and an ejection part configured to eject the optical recording medium in response to the second determination part determining that the wobble of the one of the spiral track and the concentric tracks has no part thereof out of compliance with the one of the DVD+R standard and the DVD+RW standard.

According to this optical recorder, the first determination part determines whether the determination information is recorded in the optical recording medium. If it is determined that the determination information is recorded in the optical recording medium, the recording part records the CSS- encrypted content in the data area of the optical recording medium and the key information in the management information area of the optical recording medium. Meanwhile, if the determination information is not recorded in the optical recording medium, the second determination part determines whether the wobble of the track of the optical recording medium has a part thereof out of compliance with the DVD+R or DVD+RW standard. If it is determined that the wobble of the track of the optical recording medium has no part thereof out of compliance with the DVD+R or DVD+RW standard, the ejection part ejects the optical recording medium. Accordingly, it is possible to record CSS-encrypted content and its key information in the optical recording medium of the present invention. As a result, it is possible to record CSS-encrypted content and its key information in the optical recording medium of the present invention in a reproducible manner.

According to one aspect of the present invention, there is provided an optical recording system for the optical recording medium of the present invention, the optical recording including an optical recorder; and a processor configured to record, via the optical recorder, CSS-encrypted content and the key information thereof in the data area and the management information area, respectively, of the optical recording medium, wherein the optical recorder includes a first determination part configured to determine whether determination information showing that only the CSS- encrypted content is recordable is recorded in the optical recording medium; a recording part configured to record the CSS-encrypted content and the key information thereof in the data area and the management information area, respectively, of the optical recording medium in response to the first determination part determining that the determination information is recorded in the optical recording medium; a second determination part configured to determine whether the wobble of one of a spiral track and concentric tracks has a part thereof out of compliance with one of the DVD+R standard and the DVD+RW standard in response to the first determination part determining that the determination information is not contained in the optical recording medium; and an ejection part configured to eject the optical recording medium in response to the second determination part determining that the wobble of the one of the spiral track and the concentric tracks has no part thereof out of compliance with the one of the DVD+R standard and the DVD+RW standard.

Since this optical recording system includes the optical recorder of the present invention, it is possible to record CSS-encrypted content in the data area of the optical recording medium and its key information in the management information area of the optical recording medium. As a result, it is possible to record CSS-encrypted content and its key information in the optical recording medium of the present invention in a reproducible manner.

According to one aspect of the present invention, there is provided a method of determining whether an optical recording medium supports recording of content encrypted with the Content Scrambling System (CSS), the method including the steps of (a) determining whether determination information showing that only the CSS-encrypted content is recordable is contained in the optical recording medium; and (b) determining that the optical recording medium supports the recording of the CSS-encrypted content in response to step (a) determining that the determination information is contained in the optical recording medium. According to this method, it is determined whether determination information showing that only CSS-encrypted content is recordable is contained in an optical recording medium. If it is determined that the determination information is contained in the optical recording medium, it is determined that the optical recording medium supports recording of CSS-encrypted content. Accordingly, it is possible to easily determine whether an optical recording medium supports recording of CSS-encrypted content.

According to one aspect of the present invention, there is provided a method of recording content encrypted with the Content Scrambling System (CSS) and key information thereof in an optical recording medium, the method including the steps of (a) determining whether determination information showing that only the CSS-encrypted content is recordable is contained in the optical recording medium; (b) recording the CSS-encrypted content and the key information thereof in the data area and the management information area, respectively, of the optical recording medium in response to step (a) determining that the determination information is contained in the optical recording medium; (c) determining whether the wobble of the track of the optical recording medium has a part thereof out of compliance with one of the DVD+R standard and the DVD+RW standard in response to step (a) determining that the determination information is not contained in the optical recording medium; and (d) ejecting the optical recording medium in response to step (c) determining that the wobble of the track of the optical recording medium has no part thereof out of compliance with the one of the DVD+R standard and the DVD+RW standard.

According to this method, it is determined whether the determination information is recorded in the optical recording medium. If it is determined that the determination information is recorded in the optical recording medium, the CSS-encrypted content is recorded in the data area of the optical recording medium and the key information is recorded in the management information area of the optical recording medium. Meanwhile, if the determination information is not recorded in the optical recording medium, it is determined whether the wobble of the track of the optical recording medium has a part thereof out of compliance with the DVD+R or DVD+RW standard. If it is determined that the wobble of the track of the optical recording medium has no part thereof out of compliance with the DVD+R or DVD+RW standard, the optical recording medium is ejected. Accordingly, it is possible to record CSS-encrypted content and its key information in the optical recording medium of the present invention. As a result, it is possible to record CSS-encrypted content and its key information in the optical recording medium of the present invention in a reproducible manner.

According to one aspect of the present invention, there is provided a computer-readable recording medium tangibly embodying a program employed in an optical recorder for the optical recording medium of the present invention, the program being for causing the control computer of the optical recorder to execute the steps of (a) determining whether determination information showing that only the CSS-encrypted content is recordable is contained in the optical recording medium; (b) recording the CSS-encrypted content and the key information thereof in the data area and the management information area, respectively, of the optical recording medium in response to step (a) determining that the determination information is contained in the optical recording medium; (c) determining whether the wobble of one of a spiral track and concentric tracks has a part thereof out of compliance with one of the DVD+R standard and the DVD+RW standard in response to step (a) determining that the determination information is not contained in the optical recording medium; and (d) ejecting the optical recording medium in response to step (c) determining that the wobble of the one of the spiral track and the concentric tracks has no part thereof out of compliance with the one of the DVD+R standard and the DVD+RW standard.

According to this recording medium, when the program of the present invention is loaded into a predetermined memory and its starting address is set in a program counter, the control computer of the optical recorder determines whether the determination information is recorded in the optical recording medium. If it is determined that the determination information is recorded in the optical recording medium, the CSS-encrypted content is recorded in the data area of the optical recording medium and the key information is recorded in the management information area of the optical recording medium. Meanwhile, if the determination information is not recorded in the optical recording medium, it is determined whether the wobble of the track of the optical recording medium has a part thereof out of compliance with the DVD+R or DVD+RW standard. If it is determined that the wobble of the track of the optical recording medium has no part thereof out of compliance with the DVD+R or DVD+RW standard, the optical recording medium is ejected. Thus, according to the computer- readable recording medium of the present invention, it is possible to cause the control computer of the optical recorder to execute the recording method of the present invention. As a result, it is possible to record CSS-encrypted content and its key information in the optical recording medium of the present invention. Thus, it is possible to record CSS-encrypted content and its key information in the optical recording medium of the present invention in a reproducible manner.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings, in which:

FIG. 1 is a cross-sectional view of an optical disk for illustrating a configuration thereof according to an embodiment of the present invention; FIG. 2 is a diagram for illustrating a track in the optical disk of FIG. 1 according to the embodiment of the present invention;

FIG. 3 is a diagram for illustrating the wobble of the track in the optical disk of FIG. 1 according to the embodiment of the present invention;

FIG. 4 is a diagram for illustrating an information- frame according to the embodiment of the present invention; FIGS. 5A and 5B are waveform charts for illustrating wobble shapes of an ADIP information part according to the embodiment of the present invention;

FIGS. 6A and 6B are waveform charts for illustrating wobble shapes of a synchronization information part according to the embodiment of the present invention;

FIG. 7 is a table for illustrating an ADIP word according to the embodiment of the present invention;

FIG. 8 is a table for illustrating physical format information according to the embodiment of the present invention;

FIG. 9 is a block diagram showing a configuration of a personal computer serving as an optical recording system according to the embodiment of the present invention;

FIG. 10 is a block diagram showing a configuration of an optical disk unit in FIG. 9 according to the embodiment of the present invention; and

FIG. 11 is a flowchart for illustrating an operation of the optical disk unit of FIG. 10 according to the embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

A description is given, with reference to the accompanying drawings, of an embodiment of the present invention. FIG. 1 is a schematic diagram showing a cross-sectional shape of an optical disk 15 serving as an optical recording medium according to the embodiment of the present invention.

Referring to FIG. 1, a groove G serving as a spiral guide groove is formed in a recording layer

15c of the optical disk 15. In general, a part of an optical disk having a convex shape when viewed from the direction of incidence of laser light is referred to as a groove (G) and a part having a concave shape is referred to as a land (L) . Here, the groove G is a track for recording information, and data are recorded in the groove G. In FIG. 1, reference numeral 15a, 15b, and 15d denote a first substrate, a reflective layer, and a second substrate, respectively.

For example, the track is divided into multiple areas including Lead-in Zone, Data Zone, and Lead-out Zone in the direction from center to periphery as shown in FIG. 2. The Lead-in Zone is a management information area where management information is stored. The Data Zone is an area where user data are stored (data area) . The Lead-out Zone is an area where information for indicating the end position of data is stored. For convenience of description, the track is shown as a straight line in FIG. 2, with the right side and the left side of the paper being defined as the peripheral (outer) side and the center (inner) side, respectively, of the optical disk 15. Further, as shown in FIG. 3 as an example, the track wobbles with respect to its center (track center) . The track pitch is 0.74 μm.

The wobble shape of the track is determined by an ADIP unit and a carrier wave. The ADIP unit contains various information items. The carrier wave is used to generate a reference clock signal. According to this embodiment, a basic unit formed of one ADIP unit and a sequential carrier wave part is referred to as "information frame." As shown in FIG. 4 as an example, letting the size of one period of a carrier wave (also referred to as a wobble period) be one wobble, a single information frame 100 has a size of 93 wobbles (Wobble Numbers 0 to 92) . Of those, Wobble Numbers 0 to 7 form an ADIP unit 101, and Wobble Numbers 8 to 92 form a carrier wave part 102. Further, the ADIP unit 101 is formed of an area of Wobble Numbers 0 to 3 (hereinafter referred to as "synchronization information part 101a" for convenience of description) and an area of Wobble Numbers 4 to 7 (hereinafter referred to as "ADIP information part 101b" for convenience of description) . Each of the above-described information parts 101a and 101b is subjected to phase modulation such as PSK (Phase Shift Keying) . In the ADIP information part 101b, the four wobbles represent one-bit data. If the bit data is "0," the front two wobbles are in phase with the carrier wave part 102, and the rear two wobbles are opposite in phase to the carrier wave part 102 as shown in FIG. 5A. Meanwhile, if the bit data is "1," the front two wobbles are opposite in phase to the carrier wave part 102, and the rear two wobbles are in phase with the carrier wave part 102 as shown in FIG. 5B. The synchronization information part 101a has a word synchronization (word sync) signal, that is, has all of the four wobbles opposite in phase to the carrier wave part 102, as shown in FIG. 6A if the ADIP information part 101b in the next information frame 100 is the first bit of data. Further, if the ADIP information part 101b contains bit data, the synchronization information part 101a has a bit synchronization (bit sync) signal, that is, has the first wobble opposite in phase to the carrier wave part 102 and the remaining three wobbles in phase with the carrier wave part 102 as shown in FIG. 6B.

As shown in FIG. 7, one ADIP word is obtained with 52 information frames 100.

The ADIP unit 101 in the Lead-in Zone contains physical format information. This physical format information is different from the physical format information in the DVD+R standard (ECMA-349) or the DVD+RW standard (ECMA-337) only in Byte 16. That is, as shown in FIG. 8, a hexadecimal numeral "01h" is contained as "content limitation information" in Byte 16. This ^λλ0lh" means that only content encrypted with CSS (CSS-encrypted content) can be recorded in the data area of the optical disk 15. According to the DVD+R standard or the DVD+RW standard (hereinafter also referred to collectively as "DVD+R/RW standard" for convenience of description) , Byte 16 of the physical format information is unused, and ^λλ00h" is set therein.

The ADIP unit 101 in the data area contains address information. Here, addresses are set so as to become smaller in the direction from disk center to disk periphery. According to the DVD+R/RW standard, addresses are set so as to become larger in the direction from disk center to disk periphery. As described above, the optical disk 15 of this embodiment is an optical disk for recording that complies with the DVD+R/RW standard except for Byte 16 of physical format information and the address information of the ADIP unit 101 in the data area. As described above, according to the optical disk 15 of this embodiment, the "content limitation information" (determination information) is contained in physical formation information that determines the wobble shape of a track in the Lead-in Zone. Accordingly, it is possible to record CSS-encrypted content and its key information. As a result, it is possible to record CSS-encrypted content in a reproducible manner. The CSS-encrypted content is recorded in the data area, and its key information is recorded in an unused area of the Lead-in Zone.

Further, according to the optical disk 15 of this embodiment, the address information of the ADIP unit 101 in the data area is set so that addresses become smaller in the direction from disk center to disk periphery. Therefore, the optical disk 15 is determined as an abnormal disk and rejected by an optical disk unit that does not support the optical disk 15. Accordingly, it is possible to prevent content other than CSS-encrypted content from being recorded on the optical disk 15. That is, the optical disk 15 serves as an optical disk for recording dedicated to CSS-encrypted content.

Further, in this embodiment, a description is given of the case where the "content limitation information" is stored in Byte 16 of physical format information. However, the present invention is not limited to this, and the "content limitation information" may be stored in, for example, Byte 17 of physical format information. According to the DVD+R/RW standard, Byte 17 of physical format information is where "Disk Application Code" is stored. Therefore, in this case, there is no compatibility in recording with the conventional optical disk unit. Further, in this embodiment, a description is given of the case where the optical disk 15 has the single recording layer 15c. However, the present invention is not limited to this, and the optical disk 15 may have multiple recording layers. FIG. 9 is a block diagram showing a personal, computer (PC) 10 serving as an optical recording system according to this embodiment.

Referring to FIG. 9, the PC 10 includes a main controller 92, an optical disk unit 20 serving as a recording unit (recorder) and a playback

(reproduction) unit, a hard disk drive (HDD) 94, an input unit 95, a display unit 96, a drive interface 97, and a network controller 98.

The main controller 92 includes a CPU 92a, a ROM 92b, and a RAM 92c. The CPU 92a controls the entire PC 10 and performs a below-described recording operation based on one or more of the programs contained in the ROM 92b and the RAM 92c.

The HDD 94 includes a hard disk 94a and a drive unit 94b for driving the hard disk 94a. Various programs written in a code decodable in 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 into the RAM 92c of the main controller 92 as required.

The display unit 96 includes a display part (not graphically illustrated) using, for example, a CRT, a liquid crystal display (LCD) , or a plasma display panel (PDP) , and displays various information items as requested by the main controller 92.

The input unit 95 includes at least one of input media (not graphically illustrated) such as a keyboard, a mouse, a tablet, a light pen, and a touch panel, and notifies the main controller 92 of various information items input by a user. Information from the input medium may be input wirelessly. Further, the display unit 96 and the input unit 95 may be integrated into, for example, an LCD with a touch panel . The drive interface 97 is a bidirectional interface between the main controller 92 and the optical disk unit 20 and the HDD 94. The drive interface 97 is compliant with a standard interface such as ATAPI (Attachment Packet Interface) , SCSI (Small Computer System Interface), or USB (Universal Serial Bus) .

The network controller 98 controls bidirectional Communications using a public line. The PC 10 can connect to the Internet through this network controller 98.

The optical disk unit 20 records information on the loaded optical disk 15 based on an instruction from the main controller 92.

Referring to FIG. 10, by way of example, this optical disk unit 20 includes a spindle motor -22 for rotating the set optical disk 15, an optical pickup unit 23, a seek motor 21 for driving the optical pickup unit 23 in the radial directions of the optical disk 15, a laser control circuit 24, an encoder 25, a drive control circuit 26, a reproduced signal processing circuit 28, a buffer RAM 34, a buffer manager 37, an interface 38, a flash memory 39, a CPU 40, and a RAM 41. The arrows in FIG. 10 represent typical information or signal flows, and do not represent all connections among the blocks.

Further, the optical disk unit 20 supports the above- described optical disk 15.

The optical pickup unit 23 is for focusing laser light onto the recording layer 15c of the optical disk 15 and receiving reflected light from the recording layer 15c. This optical pickup unit 23 includes a semiconductor laser that emits laser light of a wavelength corresponding to the optical disk 15, an objective lens that focuses the laser light emitted from the semiconductor laser onto the recording layer 15c of the optical disk 15, a light receiver that receives returning light reflected from the recording layer 15c, and a drive system (a focus actuator and a tracking actuator) for driving the objective lens, of which graphical illustration is omitted. The light receiver includes multiple light- receiving elements (or light-receiving areas), and outputs signals each corresponding to the amount of light received in a corresponding one of the light- receiving elements (light-receiving areas)

(photoelectrically converted signals) to the reproduced signal processing circuit 28.

The reproduced signal processing circuit 28 generates servo signals (such as a focus error signal and a tracking error signal) , a wobble signal, and an RF signal the same as conventionally, based on the output signals of the light receiver (photoelectrically converted signals) . (See, for example, Japanese Laid-Open Patent Application No. 10-69646.) The servo signals obtained here are output to the drive control circuit 26, the CPU 40, etc. Further, the reproduced signal processing circuit 28 obtains synchronization information, physical format information, and address information from the wobble signal. The synchronization information obtained here is output to the encoder 25, the drive control circuit 26, etc., and the physical format information and the address information are output to the CPU 40. Further, the reproduced signal processing circuit 28 performs decoding and error detection on the RF signal. If an error is detected, the reproduced signal processing circuit 28 performs error correction on the RF signal, and thereafter stores the RF signal in the buffer RAM 34 through the buffer manager 37 as reproduced data.

The drive control circuit 26 generates a tracking actuator driving signal for correcting error in the position of the objective lens in the tracking directions based on the tracking error signal fed from the reproduced signal processing circuit 28. Further, the drive control circuit 26 generates a focus actuator driving signal for correcting a focus error of the objective lens based on the focus error signal fed from the reproduced signal processing circuit 28. The driving signals of the actuators generated here are output to the optical pickup unit 23. Thereby, tracking control and focus control are performed. Further, 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 based on instructions from the CPU 40. The generated driving signals of the motors 21 and 22 are output to the seek motor 21 and the spindle motor 22, respectively.

Data to be recorded on the optical disk 15 (recording data) and data reproduced from the optical disk 15 (reproduced data) are temporarily stored in the buffer RAM 34. Inputting data to and outputting data from the buffer RAM 34 are managed by the buffer manager 37.

Based on an instruction from the CPU 40, the encoder 25 extracts recording data stored in the buffer RAM 34 through the buffer manager 37, and modulates and adds an error-correcting code to the data, thereby generating a write signal to be written to the optical disk 15. The write signal generated here is output to the laser control circuit 24.

The laser control circuit 24 controls the light emission power of the semiconductor laser of the optical pickup unit 23. For example, in the case of recording, a signal for driving the semiconductor laser is generated in the laser control circuit 24 based on the write signal, recording conditions, and the light emission characteristics of the semiconductor laser.

The interface 38 is a bidirectional communications interface that interfaces with the main controller 92 through the drive interface 97. The interface 38 is compliant with the same standard interface as the drive interface 97.

The flash memory 39 contains various programs written in a code decodable in the CPU 40 including a program according to the present invention, recording conditions including recording power and recording strategy information, and the light emission characteristics of the semiconductor laser .

The CPU 40 controls the entire optical disk unit 20 in accordance with one or more of the programs stored in the flash memory 39, and stores data necessary for the control in the RAM 41 and the buffer RAM 34.

[Video Content Recording Operation] Next, a description is given of the operation of recording CSS-encrypted video content in the PC 10 configured as described above. Here, it is assumed that the CSS-encrypted content and its key information are downloaded from the Web site of a provider of the CSS-encrypted content through the Internet, and are temporarily contained in the hard disk 94a. Further, the optical disk 15 is loaded in the optical disk unit 20. (I) When receiving a user's request to write

CSS-encrypted content onto the optical disk 15 through the input unit 95, the CPU 92a of the main controller 92 instructs the optical disk unit 20 to write the CSS-encrypted content and its key information stored in the hard disk 94a.

(a) When receiving the instruction to write the CSS-encrypted content and its key information from the main controller 92, the CPU 40 of the optical disk unit 20 sets the starting address of a program corresponding to the flowchart of FIG. 11 contained in the flash memory 39 in the program counter of the CPU 40, and starts processing (hereinafter referred to as "write operation" for convenience of description) . The flowchart of FIG. 11 corresponds to a processing algorithm executed by the CPU 40 .

(b) Referring to FIG. 11, first, in step S401, Byte 16 of the physical format informa-tion of the set optical disk 15 is extracted. The physical format information is read out to be stored in the RAM 41 when the optical disk 15 is set (loaded) .

(c) Next, in step S403, it is determined whether the extracted Byte 16 of the physical format information is "01h." That is, it is determined whether the set optical disk 15 supports CSS- encrypted content recording. Here, since the optical disk 15 is set, the extracted Byte 16 of the physical format information is "01h." Therefore, an affirmative determination is made (YES in step S403), and the write operation proceeds to step S405. That is, it is determined that the set optical disk 15 supports CSS-encrypted content recording.

(d) In step S405, it is authorized to write the CSS-encrypted content in the data area. Thereby, writing the CSS-encrypted content in the data area through the encoder 25, the laser control circuit 24, and the optical pickup unit 23 is started.

(e) Next, in step S407, it is determined whether writing the CSS-encrypted content in the data area is completed by comparing the amount of data to be written according to the instruction of the main controller 92 and the amount of data that has been written. If writing the CSS-encrypted content in the data area is not completed, a negative determination is made (NO in step S407), and it is again determined whether writing the CSS-encrypted content in the data area is completed after passage of a predetermined period of time. Meanwhile, if writing the CSS- encrypted content in the data area is completed, an affirmative determination is made (YES in step S407), and the write operation proceeds to step S409.

(f) In step S409, it is authorized to write the key information of the CSS-encrypted content in the Lead-in Zone. Thereby, writing Lead-in information including the key information in the Lead-in Zone of the optical disk 15 through the encoder 25, the laser control circuit 24, and the optical pickup unit 23 is started.

(g) Next, in step S411, the main controller 92 is notified that writing the CSS-encrypted content and its key information has ended normally. Then, the write operation ends.

(h) If the extracted Byte 16 of the physical format information is not "01h" in step S403, a negative determination is made in step S403 (NO in step S403), and the write operation proceeds to step S421.

(i) In step S421, it is determined whether the address information of an ADIP unit in the data area is set so that addresses become smaller in the direction from disk center to disk periphery. That is, it is determined whether the physical addresses of the data area become smaller in the direction from disk center to disk periphery. If the physical addresses of the data area do not become smaller in the direction from disk center to disk periphery, a negative determination is made (NO in step S421) , and the write operation proceeds to step S423.

(j) In step S423, a disk ejection mechanism (not graphically illustrated) is instructed to eject the set optical disk.

(k) Next, in step S425, the main controller 92 is notified to replace the set optical disk with an optical disk that supports CSS-encrypted content recording. Then, the write operation ends.

(1) Meanwhile, if the physical addresses of the data area become smaller in the direction from disk center to disk periphery in step S421, an affirmative determination is made (YES in step S421) , and the write operation proceeds to step S427. (m) In step S427, the main controller 92 is notified that writing the CSS-encrypted content and its key information is to end abnormally. Then, the write operation ends. (II) When receiving "Normal End" from the optical disk unit 20, the CPU 92a of the main controller 92 instructs the HDD 94 to erase the CSS- encrypted content and its key information contained in the hard disk 94a. (III) The CPU 92a of the main controller 92 notifies the user that recording the CSS-encrypted content has ended normally by displaying a message to that effect on the display part of the display unit 96. Then, the CPU 92a instructs the optical disk unit 20 to eject the optical disk 15, and ends the operation of recording the CSS-encrypted content.

(IV) When receiving "Disk Replacement" from the optical disk unit 20, the CPU 92a of the main controller 92 notifies the user to replace the set optical disk with an optical disk on which CSS- encrypted content can be recorded by displaying a message to that effect on the display part of the display unit 96.

(V) When receiving "Abnormal End" from the optical disk unit 20, the CPU 92a of the main controller 92 notifies the user that recording the CSS-encrypted content has failed by displaying a message to that effect on the display part of the display unit 96. As is clear from the above description, in the PC 10 according to this embodiment,, the optical disk unit 20 realizes an optical recorder, and the CPU 92a and a program executed by the CPU 92a realize a processor. The processor realized by the CPU 92a executing processing according to the program may be partly or entirely formed by hardware.

Further, in the optical disk unit 20, the encoder 25, the laser control circuit 24, and the optical pickup unit 23 realize a recording part, and the CPU 40 and a program executed by the CPU 40 realize a first determination part, a second determination part, and an ejection part. Each σf the parts realized by the CPU 40 executing processing according to the program may be partly or entirely formed by hardware.

Further, a determination method and a recording method according to the present invention are performed in the write operation in the optical disk unit 20. Further, according to this embodiment, a program according to the present invention is contained in the program corresponding to the flowchart of FIG. 11 among the programs recorded in the flash memory 39. As described above, according to the optical disk unit 20 of this embodiment, prior to recording CSS-encrypted content and its key information on a set (loaded) optical disk, it is determined whether the optical disk contains "content limitation information" (determination information) indicating that only CSS-encrypted content is recordable on the optical disk. If it is determined that "content limitation information" is contained in the optical disk, the CSS-encrypted content and its key information are recorded on the optical disk. If no "content limitation information" is contained in the optical disk, it is determined whether the physical addresses of the data area become smaller in the direction from disk center to disk periphery, that is, whether the wobble of the track of the optical disk has a wobble part out of compliance with the DVD+R/RW standard. If it is determined that the wobble of the track of the optical disk has no wobble part out of compliance with the DVD+R/RW standard, the set optical disk is ejected. Accordingly, it is possible to record CSS-encrypted content and its key information on the optical disk 15 according to the embodiment of the present invention. As a result, it is possible to record the CSS-encrypted content on the optical disk 15 for recording according to the embodiment of the present invention in such a manner as to enable the CSS-encrypted content to be reproduced. Therefore, for example, video content downloaded with its key information can be recorded on the optical disk 15 in a reproducible manner.

Further, according to the optical disk 15 of this embodiment, the wobble of a track has a wobble part out of compliance with the DVD+R/RW standard. Accordingly, when the optical disk 15 is loaded into the conventional optical disk unit, the optical disk 15 is immediately ejected. Accordingly, it is possible to record only CSS-encrypted content on the optical disk 15 according to this embodiment. That is, the optical disk 15 according to the embodiment is an optical disk for recording dedicated to CSS- encrypted content.

Further, the PC 10 according to this embodiment includes the optical disk unit 20. Therefore, according to the PC 10, it is possible to record CSS-encrypted content and its key information in the optical disk 15 of this embodiment. As a result, it is possible to record CSS-encrypted content on the optical disk 15 for recording according to this embodiment in a reproducible manner In this embodiment, a description is given of the case where physical addresses are set so as to become smaller in the direction from disk center to disk periphery over the entire data area. However, the present invention is not limited to this, and physical addresses may be set so as to become smaller in the direction from disk center to disk periphery in part of the data area.

That is, it is only necessary that the wobble of the track have at least a part thereof out of compliance with the DVD+R/RW standard.

Further, in this embodiment, a description is given of the case where the address information of the ADIP unit 101 in the data area is set so that addresses become smaller in the direction from disk center to disk periphery in order to provide the wobble of the track with a part that is not compliant with the DVD+R/RW standard. However, the present invention is not limited to this.

For example, the address information of the ADIP unit 101 in the data area may be set so that addresses are arranged at random or include an impossible (impossibly large) address in a part thereof.

Further, the wobble of the track may also be determined so as to include a (wobble) part having a frequency higher than the frequency provided in the DVD+R/RW standard. Specifically, the wobble of the track may be determined so as to include a (wobble) part having a frequency 1.5 times the frequency provided in the DVD+R/RW standard. As a result, the wobble of the track has at least part thereof out of compliance with the DVD+R/RW standard.

Further, the wobble of the track may also be determined so as to include a (wobble) part having amplitude smaller than the amplitude provided in the DVD+R/RW standard. Specifically, the wobble of the track may be determined so as to include a (wobble) part having amplitude half the amplitude provided in the DVD+R/RW standard. As a result, the wobble of the track has at least part thereof out of compliance with the DVD+R/RW standard.

Further, the wobble of the track may also be determined so as to include a (wobble) part subjected to phase modulation different from the phase modulation provided in the DVD+R/RW standard. As a result, the wobble of the track has at least part thereof out of compliance with the DVD+R/RW standard.

Further, the wobble of the track in the data area may be determined so as to include a (wobble) part that does not include the ADIP unit 101, to include a (wobble) part that does not include the synchronization information part 101a, or to include a (wobble) part that does not include the ADIP information part 101b. As a result, the wobble of the track has at least part thereof out of compliance with the DVD+R/RW standard.

That is, it is only necessary that the wobble of the track have at least part thereof out of compliance with the DVD+R/RW standard. In this case, the determination in step S421 (FIG. 11) is modified in accordance with how part of the wobble of the track is out of compliance with the DVD+R/RW standard; As a result, the same effects as in the above- described embodiment can be produced. In the above embodiment, a description is given of the case where the optical recording system is a personal computer. Alternatively, the optical recording system may be a DVD recorder that performs the same processing as the above-described operation of recording CSS-encrypted content. According to one aspect of the present invention, there is provided an optical recording medium for recording having one of a spiral track and concentric tracks formed thereon, the optical recording medium having a recording area including a management information area and a data area, wherein content encrypted with the Content Scrambling System (CSS) is recordable in the data area, and key information of the CSS-encrypted content is recordable in the management information area.

According to one aspect of the present invention, there is provided an optical recorder for the optical recording medium of the present invention, the optical recorder including a first determination part configured to determine whether determination information showing that only the CSS-encrypted content is recordable is recorded in the optical recording medium; a recording part configured to record the CSS-encrypted content and the key information thereof in the data area and the management information area, respectively, of the optical recording medium in response to the first determination part determining that the determination information is recorded in the optical recording medium; a second determination part configured to determine whether the wobble of one of a spiral track and concentric tracks has a part thereof out of compliance with one of the DVD+R standard and the DVD+RW standard in response to the first determination part determining that the determination information is not contained in the optical recording medium; and an ejection part configured to eject the optical recording medium in response to the second determination part determining that the wobble of the one of the spiral track and the concentric tracks has no part thereof out of compliance with the one of the DVD+R standard and the DVD+RW standard.

According to one aspect of the present invention, there is provided a method of determining whether an optical recording medium supports recording of content encrypted with the Content Scrambling System (CSS), the method including the steps of (a) determining whether determination information showing that only the CSS-encrypted content is recordable is contained in the optical recording medium; and (b) determining that the optical recording medium supports the recording of the CSS-encrypted content in response to step (a) determining that the determination information is contained in the optical recording medium.

According to this method, it is determined whether determination information showing that only CSS-encrypted content is recordable is contained in an optical recording medium. If it is determined that the determination information is contained in the optical recording medium, it is determined that the optical recording medium supports recording of CSS-encrypted content. Accordingly, it is possible to easily determine whether an optical recording medium supports recording of CSS-encrypted content. According to one aspect of the present invention, there is provided a method of recording content encrypted with the Content Scrambling System (CSS) and key information thereof in an optical recording medium, the method including the steps of (a) determining whether determination information showing that only the CSS-encrypted content is recordable is contained in the optical recording medium; (b) recording the CSS-encrypted content and the key information thereof in the data area and the management information area, respectively, of the optical recording medium in response to step (a) determining that the determination information is contained in the optical recording medium; (c) determining whether the wobble of the track of the optical recording medium has a part thereof out of compliance with one of the DVD+R standard and the DVD+RW standard in response to step (a) determining that the determination information is not contained in the optical recording medium; and (d) ejecting the optical recording medium in response to step (c) determining that the wobble of the track of the optical recording medium has no part thereof out of compliance with the one of the DVD+R standard and the DVD+RW standard.

[Industrial Applicability] As described above, an optical recording medium according to the present invention is suitable for recording CSS-encrypted content in a reproducible manner. Further, an optical recorder and an optical recording system according to the present invention are suitable for recording CSS-encrypted content on the optical recording medium of the present invention in a reproducible manner. Further, a determination method according to the present invention is suitable for easily determining whether an optical recording medium supports CSS-encrypted content recording. Further, a recording method according to the present invention is suitable for recording CSS-encrypted content on the optical recording medium of the present invention in a reproducible manner. Further, a computer-readable recording medium tangibly embodying a program according. to the present invention is suitable for causing the optical recorder to record CSS-encrypted content on the optical recording medium of the present invention in a reproducible manner.

The present invention is not limited to the specifically disclosed embodiment, and variations and modifications may be made without departing from the scope of the present invention.

The present application is based on Japanese Priority Patent Application No. 2006-239947, filed on September 5, 2006, the entire contents of which are hereby incorporated by reference.

Claims

1. An optical recording medium for recording having one of a spiral track and concentric tracks formed thereon, the optical recording medium having a recording area including a management information area and a data area, wherein: content encrypted with a Content Scrambling System (CSS) is recordable in the data area, and key information of the CSS-encrypted content is recordable in the management information area.

2. The optical recording medium as claimed in claim 1, wherein determination information showing that only the CSS-encrypted content is recordable in the data area is prerecorded.

3. The optical recording medium as claimed in claim 2, wherein: the one of the spiral track and the concentric tracks wobbles, and the determination information is contained in information on a shape of the wobble of the one of the spiral track and the concentric tracks.

4. The optical recording medium as claimed in claim 3, wherein at least a part of the wobble has a frequency higher than a frequency provided in one of a DVD+R standard and a DVD+RW standard.

5. The optical recording medium as claimed in claim 3, wherein at least a part of the wobble has an amplitude smaller than an amplitude provided in one of a DVD+R standard and a DVD+RW standard.

6. The optical recording medium as claimed in claim 3, wherein at least a part of the wobble is subjected to phase modulation different from phase modulation provided in one of a DVD+R standard and a DVD+RW standard.

7. The optical recording medium as claimed in claim 3, wherein at least a part of the wobble has address information different from address information provided in one of a DVD+R standard and a DVD+RW standard.

8. The optical recording medium as claimed in claim 1, wherein only the content encrypted with the CSS is recordable in the data area

9. An optical recorder for the optical recording medium as set forth in claim 1, the optical recorder comprising: a first determination part configured to determine whether determination information showing that only the CSS-encrypted content is recordable is recorded in the optical recording medium; a recording part configured to record the CSS-encrypted content and the key information thereof in the data area and the management information area, respectively, of the optical recording medium in response to the first determination part determining that the determination information is recorded in the optical recording medium; a second determination part configured to determine whether a wobble of the one of the spiral track and the concentric tracks has a part thereof out of compliance with one of a DVD+R standard and a DVD+RW standard in response to the first determination part determining that the determination information is not contained in the optical recording medium; and an ejection part configured to eject the optical recording medium in response to the second determination part determining that the wobble of the one of the spiral track and the concentric tracks has no part thereof out of compliance with the one of the DVD+R standard and the DVD+RW standard.

10. An optical recording system for the optical recording medium as set forth in claim 1, the optical recording comprising: an optical recorder; and a processor configured to record, via the optical recorder, the CSS-encrypted content and the key information thereof in the data area and the management information area, respectively, of the optical recording medium, wherein the optical recorder includes a first determination part configured to determine whether determination information showing that only the CSS-encrypted content is recordable is recorded in the optical recording medium; a recording part configured to record the

CSS-encrypted content and the key information thereof in the data area and the management information area, respectively, of the optical recording medium in response to the first determination part determining that the determination information is recorded in the optical recording medium; a second determination part configured to determine whether a wobble of the one of the spiral track and the concentric tracks has a part thereof out of compliance with one of a DVD+R standard and a DVD+RW standard in response to the first determination part determining that the determination information is not contained in the optical recording medium; and an ejection part configured to eject the optical recording medium in response to the second determination part determining that the wobble of the one of the spiral track and the concentric tracks has no part thereof out of compliance with the one of the DVD+R standard and the DVD+RW standard.

11. A method of determining whether an optical recording medium supports recording of content encrypted with a Content Scrambling System (CSS), the method comprising the steps of:

(a) determining whether determination information showing that only the CSS-encrypted content is recordable is contained in the optical recording medium; and (b) determining that the optical recording W

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rαedium supports the recording of the CSS-encrypted content in response to said step (a) determining that the determination information is contained in the optical recording medium.

12. A method of recording content encrypted with a Content Scrambling System (CSS) and key- information thereof in an optical recording medium, the method comprising the steps of: 0 (a) determining whether determination information showing that only the CSS-encrypted content is recordable is contained in the optical recording medium;

(b) recording the CSS-encrypted content and5 the key information thereof in a data area and a management information area, respectively, of the optical recording medium in response to said step (a) determining that the determination information is contained in the optical recording medium; 0 (c) determining whether a wobble of a track of the optical recording medium has a part thereof out of compliance with one of a DVD+R standard and a DVD+RW standard in response to said step (a) determining that the determination information is not5 contained in the optical recording medium; and (d) ejecting the optical recording medium in response to said step (c) determining that the wobble of the track of the optical recording medium has no part thereof out of compliance with the one of the DVD+R standard and the DVD+RW standard.

13. A computer-readable recording medium tangibly embodying a program employed in an optical recorder for the optical recording medium as set forth in claim 1, the program being for causing a control computer of the optical recorder to execute the steps of:

(a) determining whether determination information showing that only the CSS-encrypted content is recordable is contained in the optical recording medium;

(b) recording the CSS-encrypted content and the key information thereof in the data area and the management information area, respectively, of the optical recording medium in response to said step (a) determining that the determination information is contained in the optical recording medium;

(c) determining whether a wobble of the one of the spiral track and the concentric tracks has a part thereof out of compliance with one of a DVD+R standard and a DVD+RW standard in response to said step (a) determining that the determination information is not contained in the optical recording medium; and

(d) ejecting the optical recording medium in response to said step (c) determining that the wobble of the one of the spiral track and the concentric tracks has no part thereof out of compliance with the one of the DVD+R standard and the DVD+RW standard.