JP7716620B2 - Optical disc and optical disc device - Google Patents

Description

This disclosure relates to an optically recordable optical disc, and a playback device and recording device for the optical disc.

In recent years, the recording density of optical discs has continued to increase. In the video field, optical discs such as DVDs and BDs (Blu-ray (registered trademark) Discs) are well known. While these optical discs are used for recording video, they are also used as external recording media for personal computers. While hard disks and flash memory are also used as external recording media for personal computers, optical discs offer advantages over these media, such as a long lifespan, high reliability, and no need for storage power. These advantages have led to optical discs attracting attention as an archiving medium for important data in data centers and other locations. In this context, the optical disc with the largest capacity currently available is the 300GB Archive Disc, but there is a demand for even higher density.

One way to increase the density of optical discs is to narrow the track pitch, thereby increasing radial density. However, narrowing the track pitch also creates the problem of increased crosstalk, whereby recorded signals from adjacent tracks interfere with each other when reading recorded data.

On the other hand, optical discs have physical addresses to identify the locations where user data is recorded and played back. One method of creating physical addresses is a wobble address, which is created by meandering the track (hereafter referred to as a wobble). Recording physical addresses using wobbles has the advantage of not reducing recording capacity, as the signal can be detected using a detection method separate from that used to record and play back user data, and is therefore widely used in BDs and other media.

Patent Document 1 discloses a method of representing addresses using wobbles that can be reproduced from both land and groove tracks on a land-groove recording disc. The optical disc disclosed in Patent Document 1 has multiple address allocation areas, and by arranging the wobble shapes of the groove adjacent to the inner side of one address allocation area on a land so that the wobble shapes of the groove adjacent to the outer side are identical, it is possible to reproduce data from the land while minimizing the impact of groove width variations on the recorded data.

International Publication No. 2014/192292

However, narrowing the track pitch to further increase density poses the problem that the aforementioned crosstalk also interferes with the wobble signal when reproducing the address signal, reducing the reliability of address information detection.

This disclosure provides an optical disc and optical disc device that improves the reliability of address information detection while maintaining access performance by equalizing the frequency of address information detection.

In order to solve the above problem, the optical disc disclosed herein has an address information unit, which is a unit for identifying a physical location, and the address information unit has multiple address information bits, and each address information bit has multiple areas where it can be allocated, and the address information unit selects one of the areas to form address information, and an area unit is composed of multiple address information units, and the address information formed in the address information units included in the area unit is the same, and the areas selected for the address information units included in the area unit are configured to be different from each other.

The optical disc device of the present disclosure also includes an area determination unit that determines an area to be detected, an address detection value storage unit that stores address detection values of a plurality of address information units included in an area unit, a selective addition unit that selects, adds, and outputs the address detection values stored in the address detection value storage unit based on the area determined by the area determination unit, and an address information unit position determination unit that determines position information of the address information unit based on the output of the selective addition unit and the area determined by the area determination unit.
It is equipped with:

The optical disc and optical disc device disclosed herein are effective in reproducing address information with high reliability while maintaining access performance equivalent to that of conventional devices.

Schematic diagram of an optical disc according to an embodiment. 1 is an enlarged view of a recording surface of an optical disc according to an embodiment of the present invention; FIG. 1 is a diagram for explaining the structure of an address information unit (ADIP) of an optical disc according to an embodiment of the present invention; FIG. 1 is a diagram illustrating the shape of a wobble having address information according to an embodiment. FIG. 1 is a diagram for explaining an arrangement of ADIPs according to an embodiment. FIG. 1 is a diagram for explaining the arrangement of address information of consecutive ADIPs and areas to be arranged in the embodiment. 1 is a block diagram of an optical disc device according to an embodiment of the present invention; FIG. 1 is a diagram for explaining the configuration and operation of a wobble processing unit according to an embodiment.

(Embodiment)
Optical discs and optical disc devices according to embodiments will be described below with reference to the drawings.

Figure 1 is a schematic diagram of an optical disc according to this embodiment. As shown in Figure 1, groove tracks 102 are formed spirally on an optical disc 101. Land tracks 103 are formed between the spiral groove tracks 102, and on the optical disc 101, both the groove tracks 102 and the land tracks 103 are used as recording tracks. The groove tracks 102 and land tracks 103 divide one circumference at a fixed angle to form ADIP (Address In Pre-Groove) 104, which is an address information unit that identifies a physical location on the optical disc 101. The ADIP 104 has a synchronization area 105 at its beginning, followed by an address information area 106. This configuration is maintained constant at the same angle radially from the inner to outer circumference of the optical disc 101.

Figure 2 is an enlarged view of a portion of the recording surface of the optical disc 101. The groove tracks 102 are formed on the recording surface by transferring grooves formed on a stamper during disc manufacturing, and are located close to the side where light is irradiated. Furthermore, when forming grooves on the stamper, the stamper is formed using a constant beam intensity in the disc manufacturing equipment, so the groove width is also constant. The groove tracks 102 on the optical disc 101 formed by this transfer also have a nearly constant track width across the entire surface of the optical disc 101. Note that there are manufacturing methods in which the stamper is manufactured with a large or small number of transfers, in which case the track width of the land tracks 103 is constant across the entire surface of the optical disc 101. In the case of such optical discs, the land tracks 103 and groove tracks 102 in this embodiment can be considered interchangeable.

Moreover, as shown in Figure 2, the groove track 102 and land track 103 meander at a constant interval over most of the track. This meandering is called a wobble. When the light spot 201 follows the groove track 102 or land track 103, the wobble is formed at a period shorter than the reaction speed of the light spot 201. As a result, a displacement occurs in the relative position of the light spot 201 and the groove track 102 or land track 103. This displacement can be optically detected and converted into an electrical signal to detect the shape of the wobble. By generating a clock synchronized with the wobble detection signal, the wobble detection signal can be used to detect the track length and linear velocity of the optical disc 101, or to record sub-information by changing the shape of the wobble. The optical disc in this embodiment records address information using wobbles, as will be described in detail later. As mentioned above, the track width of the groove tracks 102 is always constant for the convenience of disc manufacturing, but the track width of the land tracks 103 sandwiched between the groove tracks 102 may vary depending on the phase of the wobbles of the adjacent inner and outer groove tracks.

Next, the ADIP 104 will be described in detail using Figure 3. Figure 3 shows the ADIP 104's groove track 102, which is originally continuous, divided and arranged. The ADIP 104 is composed of a basic wobble 302 with a common shape for the most part. The basic wobble 302 has a shape that is a function of cos(ωt), and transitions between maximum inner circumference displacement, maximum outer circumference displacement, and maximum inner circumference displacement within one period. The portions other than the basic wobble 302 are also composed with one period of the basic wobble 302 as the minimum unit (hereinafter, one period of the basic wobble 302 will be referred to as the "wobble period"), and an ADIP unit 303 is composed of 80 wobble periods.

The synchronization area 105 consists of eight ADIP units 303, with MSK (Minimum Shift Keying) marks 301 arranged at irregular intervals based on a predetermined rule, with basic wobbles 302 filling the gaps. The MSK marks 301 are constructed by connecting one wobble cycle each of cos(1.5ωt), -cos(ωt), and -cos(1.5ωt), with the central portion forming a waveform whose phase is inverted from that of the basic wobble 302. The position of the ADIP 104 can be detected by performing phase detection at a predetermined arrangement. The MSK marks 301 are arranged to enable highly accurate positioning by performing autocorrelation detection, which adds inverted phase detection at the arrangement interval of the MSK marks 301.

In the ADIP 104, the wobble shape of the parts other than the address information wobble 310 is the same in all ADIPs 104 on the optical disc 101, and because the ADIPs 104 are arranged radially in every part from the inner periphery to the outer periphery as shown in Figure 1, the wobble shape other than the address information wobble is the same radially. Therefore, land tracks sandwiched between groove tracks of the same shape also have the same shape, so the synchronization area 105 has the same shape in the land tracks as in the groove tracks and can be detected in the same way as the groove tracks.

The address information area 106 consists of 56 ADIP units 303. Each ADIP unit 303 contains 1 bit of information, and the ADIP 104 contains 56 bits of address information, sub-information, and error correction information.

The address information wobble 310 is each ADIP unit 303 in the address information area 106 and contains 1 bit of information, with the address information area 106 as a whole containing 56 bits of information due to the 64 ADIP units. This 56 bits of information may be configured to contain not only address information, which is physical location information within the optical disc, but also sub-information such as layer information for multi-layer discs, information regarding the conditions for recording on the optical disc, copyright information, etc., as well as error correction/error detection codes for such information.

Next, the address information wobble 310 will be explained in detail using Figure 4. The address information wobble 310 focuses on one ADIP unit 303 of the ADIP 104. Figure 4 is a diagram showing how the address information wobbles 310 are arranged in a radial direction (from the inner to the outer circumference of the disc), and shows their relationship with adjacent tracks. The address information wobbles 310 have different wobble shapes because adjacent tracks have different address information, but they are arranged at the same radial angle.

The address information wobble 310 is constructed based on the address information to be provided to the land track, and four areas, area A404, area B405, area C406, and area D407, are provided as areas for placing wobble patterns based on the address information. Focusing on the land track, Figure 4 shows, from the innermost periphery, a land track with address information "0" in area A404, a land track with address information "1" in area B405, a land track with address information "1" in area C406, a land track with address information "0" in area D407, a land track with address information "1" in area A404, and a land track with address information "0" in area B405. Within any ADIP 104, the area in which address information is to be placed is selected in advance from areas A404 to D407 within that ADIP 104, and address information is not placed in different areas within the ADIP. In other words, the areas in which addresses are placed within the ADIP 104 are the same.

For example, in an ADIP 104 where area A404 is selected, a pattern 402 for address information "0" is placed in area A404 to place address information "0." This is expressed by placing wobbles having six cycles of cos(1.25ωt), -sin(ωt), and a shape of -cos(0.75ωt) in the grooves on both sides. Furthermore, when placing address information "1," a pattern 403 for address information "1" is placed. This is expressed by placing wobbles having six cycles of cos(0.75ωt), +sin(ωt), and a shape of +cos(1.25ωt) in the grooves on both sides. A basic pattern 401 is placed in the wobble in the portion where address information is not placed. Focusing on the second to seventh six-period wobbles, which have the most characteristic shapes, pattern 402 of address information "0" and pattern 403 of address information "1," pattern 402 of address information "0" has a phase difference of −90 degrees, and pattern 403 of address information "1" has a phase difference of +90 degrees with respect to cos(ωt), which is basic pattern 401 of basic wobble 302. Note that the 1.25- and 0.75-times period cos function wobbles before and after the wobble with a 90-degree phase difference are arranged to connect with a gradual phase shift to the wobble with a 90-degree phase difference, and are maintained at a phase difference of 90 degrees or less with respect to the basic wobble.

Furthermore, for any selected area in the ADIP 104 of a land track, the next area in the ADIP 104 of the land adjacent to the inner periphery, when areas A404, B405, C406, and D407 are arranged in this order, is selected, while the previous area is selected for the ADIP 104 of the land adjacent to the outer periphery. As such, there are four areas in which wobbles containing address information are placed, and the configuration is such that the areas move one by one for each land track, so that the areas used in all four consecutive land tracks are different. With this configuration, no matter which land area you focus on, the areas adjacent to it that are flanked by wobbles containing address information (address information "0" pattern 402, address information "1" pattern 403) are not located outside the areas that actually contain address information.

Figure 5 is a diagram illustrating the arrangement of ADIPs. Figure 5 shows the arrangement of ADIP 501 with region A selected, ADIP 502 with region B selected, ADIP 503 with region C selected, and ADIP 504 with region D selected. Optical disc 101 is arranged so that the region in which address information is allocated moves sequentially through four regions as ADIP 104 moves: region A - region B - region C - region D - region A - region B, etc. This arrangement makes it easy to infer the region selected by a subsequent ADIP 104 from the region selected by a preceding ADIP 104. Furthermore, one revolution is divided into seven ADIPs at a fixed angle, and the number of ADIPs per revolution (= 7) is set to a multiple of the number of selectable regions (= 4) minus 1, so that the regions allocated at the same angle change by one per revolution. In other words, the number of regions changes by one for each track. This configuration can be realized by setting the number of ADIPs per revolution = a multiple of the number of selectable areas ± 1. Furthermore, in order to have a configuration in which different areas are selected for the lands of any three consecutive tracks, this can also be realized by setting the number of ADIPs per revolution and the number of selectable areas to be coprime to each other.

Next, we will use Figure 6 to explain the address information recorded on the ADIP 104 and the arrangement of the areas in which the address information is recorded. For simplicity's sake, Figure 6 shows a configuration based on the address information to be given to the lands. As shown in Figure 4, the groove track is arranged in two areas: the land area on the inner periphery and the land area on the outer periphery.

Figure 6 shows the lowest four digits of the address information recorded in consecutive ADIPs 104, along with the area in which it is located. Seven horizontally aligned ADIPs 104 represent one circumference of the optical disc. As mentioned above, the areas in which the address information is located are arranged in the order A, B, C, D, A, B, etc. (A follows D). The four ADIPs 104 located at A, B, C, and D are grouped into area units 601, and the areas in which the ADIPs 104 included in each area unit 601 are located are different from each other. The same address information is recorded in each area unit 601, and the sequence of "0"s and "1"s in the address information, including the error correction code, is identical; only the areas in which they are located are different. In other words, the shape of the wobble pattern recording the address information is the same for each bit. Adding or averaging the detected values of the wobble pattern within each area unit 601 improves the detection SNR (Signal-to-Noise Ratio), thereby improving the reliability of address information reproduction. Furthermore, the areas allocated to each ADIP 104 are recognized in advance and then address information is detected for those areas, and the current position of ADIP 104 in area unit 601 is also recognized, so the current position on the disc for each ADIP 104 can be identified, and the position of ADIP 104 can be identified on the entire optical disc 101, thereby achieving high detection frequency and access performance for address information for each ADIP 104. Furthermore, in the optical disc of this embodiment, the number of areas included in an area unit is the same as the number of areas in which address information can be allocated, but a similar effect can be achieved as long as the number is a divisor of 2 or more.

Next, we will explain the optical disc device 700 in this embodiment.

Figure 7 is a block diagram of an optical disc device 700 in this embodiment, and its configuration and operation will be explained below.

The optical disc device 700 is composed of an optical head 701, a servo control unit 702, a signal generation unit 703, a wobble processing unit 704, an address timing generation unit 705, a playback processing unit 706, a decoder 707, an encoder 708, a recording processing unit 709, a laser driving unit 710, and a controller 711.

When an optical disc 101 is inserted into the optical disc device 700, a light beam is irradiated from the optical head 701 onto the optical disc 101. The light beam reflected by the optical disc 101 is photoelectrically converted by a photodetector (not shown) divided into four parts in the track groove direction (tangential direction) and radial direction (radial direction) included in the optical head 701, and the reflected light amount information is converted into a voltage level. The voltage information output from the four-part photodetector is used by the signal generator 703 to generate a focus error signal, a tracking error signal, a wobble signal, and a total sum signal. The total sum signal is a signal obtained by adding all the signals from the four-part photodetectors and indicates the actual amount of reflected light from the optical disc. The focus error signal is a signal detected, for example, using the astigmatism method, and is a signal obtained by adding two sets of signals from diagonally arranged four-part photodetectors and calculating the difference between them. The tracking error signal and wobble signal are signals detected by the push-pull method, and are the difference between the signals from two sets of four-segment photodetectors arranged in the tangential direction. The tracking error signal is generated by extracting frequency components from 0 Hz to several tens of kHz from the push-pull signal, and the wobble signal is generated by extracting signal components from several tens of kHz to several MHz from the push-pull signal.

The servo control unit 702 focuses the light spot on the recording surface by driving the objective lens up and down so that the focus error signal becomes 0, and then tracks the light spot to the land or groove by driving the objective lens in the radial direction so that the tracking error signal becomes 0. Whether the light spot is tracked to the land or groove is determined by driving the lens toward or away from the outer periphery depending on the tracking error. This drive polarity is determined according to instructions from the controller 711.

The wobble processing unit 704 processes the wobble signal generated by the signal generation unit 703, generates a wobble clock by multiplying the playback signal of the basic wobble 302 portion of the wobble signal, detects ADIP synchronization, and plays back address information. The address timing generation unit 705 generates playback processing timing for the target address specified by the controller 711 from the various signals generated by the wobble processing unit 704, outputs this to the playback processing unit 706, and generates recording processing timing, outputs this to the recording processing unit 709.

When reproducing user data, the reproduction processing unit 706 extracts binary data from the total sum signal generated by the signal generation unit 703 in accordance with the timing of the target reproduction address generated by the address timing generation unit 705. The decoder 707 demodulates and corrects errors in the binary data and outputs it as reproduced data. When recording user data, the encoder 708 receives the recording data, adds error correction codes, and modulates it into binary data. The recording processing unit 709 issues a command to the laser driver 710 to emit recording power in accordance with the timing of the target recording address generated by the address timing generation unit 705.

Next, using Figure 8, we will provide a detailed explanation of the wobble processing unit 704, which is the most distinctive feature of the optical disc device 700 of this embodiment.

The wobble processing unit 704 is composed of an ADIP synchronization detection unit 801, a timing generation unit 802, a first integrator 803, a second integrator 804, a third integrator 805, a fourth integrator 806, an area detection unit 807, a detection area determination unit 808, a wobble PLL 809, a multiplier 810, an absolute value detector 811, an integrator 812, an area A address detection value storage unit 813, an area B address detection value storage unit 814, an area C address detection value storage unit 815, an area D address detection value storage unit 816, a selective addition unit 817, a decoding unit 818, and an ADIP position determination unit 819.

When the wobble signal is input to the wobble processing unit 704, the wobble PLL 809 generates a wobble clock by multiplying the playback signal from the basic wobble 302, and simultaneously generates a 90-degree phase waveform with the same frequency as the basic wobble 302 but shifted in phase by +90 degrees. In the optical disc device 700 of this embodiment, the 90-degree phase waveform is sinusoidal as shown in Figure 8, but since substantially the same function can be achieved with a square wave, triangular wave, etc., these waveforms may be selected to simplify the circuit. The multiplier 810 multiplies the 90-degree phase waveform generated by the wobble PLL 809 by the wobble signal and outputs the result. The absolute value detector 811 outputs the absolute value of the output of the multiplier 810.

Meanwhile, the ADIP synchronization detection unit 801 generates an ADIP synchronization signal synchronized with the ADIP by searching for the signal of the synchronization area 105 on the optical disc 101 from the wobble signal. The timing generation unit 802 generates timing signals for areas A404 to D407 by counting a certain number of wobble clocks generated by the wobble PLL 809 based on the ADIP synchronization signal detected by the ADIP synchronization detection unit 801. This timing signal is output for all address information wobbles 310 in the ADIP 104. The first to fourth integrators 803 to 806 are reset at the boundaries of the ADIP 104 and integrate and output the output signal of the absolute value detector 811 with respect to the timing for areas A404 to D407 generated by the timing generation unit 802. When the current tracking is a land track, the area detection unit 807 outputs which of the outputs of the first to fourth integrators 803 to 806 has the largest output. When the current tracking is a groove track, it outputs which two consecutive integrators (the fourth to first are considered to be consecutive) are maximum among the first integrator 803 to the fourth integrator 806. This area detection process is performed on the result of integrating the entire ADIP, so it is possible to search for the area where address information is recorded with high reliability.

The detection area determination unit 808 determines the area at the boundary between consecutive ADIPs 104 based on the output of the area detection unit 807. If the output of the area detection unit 807 for the preceding ADIP 104 at the ADIP boundary timing is area A, the detection area determination unit 808 infers that the following ADIP is area B and therefore selects area B. Similarly, if the preceding ADIP is area B, the following ADIP will select area C; if the preceding ADIP is area C, the following ADIP will select area D; and if the preceding ADIP is area D, the following ADIP will select area A.

The integrator 812 integrates the output signal of the multiplier 810 with respect to the timing of the region selected by the detection region determination unit 808 and outputs the integrated signal. The operation of this configuration of the multiplier 810 and integrator 812 is a common means of phase detection. The integration process is reset at the beginning of the address information wobble 310 and is performed for each address information wobble 310.

The area A address detection value storage unit 813, area B address detection value storage unit 814, area C address detection value storage unit 815, and area D address detection value storage unit 816 store the output of the integrator 812 for the timing of areas A to D generated by the timing generation unit 802. Since the ADIP 104 has 56 bits of information, each unit stores 56 bits of detection value.

When the detection area determination unit 808 selects area A, the selective addition unit 817 outputs the output of the area A address detection value storage unit 813. When the detection area determination unit 808 selects area B, the selective addition unit 817 outputs the sum of the output of the area A address detection value storage unit 813 and the output of the area B address detection value storage unit 814. When the detection area determination unit 808 selects area C, the selective addition unit 817 outputs the sum of the output of the area A address detection value storage unit 813, the output of the area B address detection value storage unit 814, and the output of the area C address detection value storage unit 815. When the detection area determination unit 808 selects area D, the selective addition unit 817 outputs the sum of the output of the area A address detection value storage unit 813, the output of the area B address detection value storage unit 814, the output of the area C address detection value storage unit 815, and the output of the area D address detection value storage unit 816.

The decoding unit 818 determines whether the output of the selective addition unit 817 is positive or negative for each bit at the end of the address information area 106, and performs error correction. The ADIP position determination unit 819 determines the position information for each ADIP 104 based on the output result of the decoding unit 818, i.e., the address information for each area unit 601, and the area selected by the detection area determination unit 808. If the detection area determination unit 808 selects area A, the ADIP position information is determined as follows: ADIP position information = address information recorded in the area unit 601 x 4. If the detection area determination unit 808 selects area B, the ADIP position information is determined as follows: ADIP position information = address information recorded in the area unit 601 x 4 + 1. If the detection area determination unit 808 selects area C, the ADIP position information is determined as follows: ADIP position information = address information recorded in the area unit 601 x 4 + 2. If the detection area determination unit 808 selects area D, the ADIP position information is determined as follows: ADIP position information = address information recorded in the area unit 601 x 4 + 3.

In the optical disc 101 and optical disc device 700 of this embodiment, the number of ADIPs 104 included in the area unit is set to 4, but by setting it to the nth power of 2 (n is a natural number), the ADIP address can be calculated from the address information recorded in the area unit by bit shifting using binary numbers, which can be achieved with a simple configuration.

With this configuration, of the four ADIPs 104 in the area unit 601, address detection is performed at the end of the first ADIP using only the detection value in area A. At the end of the second ADIP, address detection is performed using the sum of the detection values in areas A and B. At the end of the third ADIP, address detection is performed using the sum of the detection values in areas A, B, and C. At the end of the fourth ADIP, i.e., the end of the area unit 601, address detection is performed using the sum of all detection values in areas A through D. This improves reliability by adding up the detection values of ADIPs 104 with identical address information. Furthermore, by simultaneously using the area in which the address information is located, it is possible to identify which ADIP 104 in the area unit 601 is being played, making it possible to identify the position of each ADIP 104, achieving both improved reliability and access performance.

The same effect can be expected by adding the detection values of any two or more of the ADIPs 104 included in the same area unit 601. Furthermore, although the optical disc device of this embodiment is configured to select and add the detection values of each area, it may also be configured to set the detection values of all detection value storage units to 0 at the beginning of the area unit, and store the detection values when reproducing the address of each area, thereby always adding all the detection values of areas A to D.

As explained above, the optical disc and optical disc device of this embodiment can provide an optical disc device with highly reliable address information reproduction and access performance by forming the same address information in multiple address information units located in different areas. Note that the configuration of the optical disc device according to the present disclosure may be realized by a processor and memory.

This disclosure is applicable to recording and reproducing devices that represent physical addresses in track grooves. Specifically, it is applicable to optical disks, optical tapes, and recording and reproducing devices thereof.

101 Optical disc 102 Groove track 103 Land track 104 ADIP
105 Synchronization area 106 Address information area 201 Light spot 302 Basic wobble 301 MSK mark 310 Address information wobble 404 Area A
405 Area B
406 Area C
407 Area D
401 Basic pattern 402 Pattern of address information "0" 403 Pattern of address information "1" 501 ADIP with area A selected
502 Area B selected ADIP
503 ADIP with area C selected
504 ADIP with region D selected
601 Area unit 700 Optical disc device 701 Optical head 702 Servo control section 703 Signal generation section 704 Wobble processing section 705 Address timing generation section 706 Reproduction processing section 707 Decoder 708 Encoder 709 Recording processing section 710 Laser driving section 711 Controller 801 ADIP synchronization detection section 802 Timing generation section 803 First integrator 804 Second integrator 805 Third integrator 806 Fourth integrator 807 Area detection section 808 Detection area determination section 809 Wobble PLL
810 Multiplier 811 Absolute value detector 812 Integrator 813 Area A address detection value storage unit 814 Area B address detection value storage unit 815 Area C address detection value storage unit 816 Area D address detection value storage unit 817 Selective addition unit 818 Decode unit 819 ADIP position determination unit

Claims (2)

having address information units that identify physical locations on the optical disc;
the address information unit has a plurality of address information bits, and each of the address information bits has a plurality of areas in which the address information bits can be arranged;
In the address information unit, address information is formed by selecting one of the plurality of areas in which the address information can be allocated,
A plurality of the address information units constitute an area unit,
the address information formed in the plurality of address information units included in the area unit is the same,
the shape of a wobble pattern recording the address information formed in the plurality of address information units included in the area unit is the same for each bit;
An optical disc, wherein a plurality of areas selected by a plurality of the address information units included in the area unit are different from one another. An optical disc device for recording and reproducing information on an optical disc ,
The optical disc is
having address information units that identify physical locations on the optical disc;
the address information unit has a plurality of address information bits, and each of the address information bits has a plurality of areas in which the address information bits can be arranged;
In the address information unit, address information is formed by selecting one of the plurality of areas in which the address information can be allocated,
A plurality of the address information units constitute an area unit,
the address information formed in the plurality of address information units included in the area unit is the same,
The areas selected by the address information units included in the area unit are different from each other,
The optical disk device
a detection area determination unit that determines the plurality of areas to be detected;
an address detection value storage unit that stores a plurality of address detection values of the plurality of address information units included in the area unit;
a selective addition unit that selects and adds the plurality of address detection values stored in the address detection value storage unit based on the plurality of areas determined by the detection area determination unit, and outputs a total value;
an address information unit position determination unit that determines the physical position of the address information unit based on the sum output by the selective addition unit and the plurality of areas determined by the detection area determination unit.