JP2019133734A - Optical disk recording device and optical disk recording method - Google Patents

Abstract

To provide an optical disk recording device and an optical disk recording method capable of recording high-precision image information on a recording surface of an optical disk.SOLUTION: An optical disk recording device includes: a data acquisition section 106 for acquiring bitmap data corresponding to image information; a wobble processing section 104 having a function of acquiring address information set in the wobble by wobble synchronization in an optical disk 201 having the wobble in a track for recording information; a recording processing section 107 having a function of determining a recording position on the optical disk on which the bitmap data is recorded using the address information; and a laser drive section 108 having a function of emitting a light beam of recording power at a recording position on the optical disk and forming a recording mark corresponding to the bitmap data.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an optical disc recording apparatus and an optical disc recording method for recording image information such as characters and images that can be read visually or by an optical reading device.

  An optical disc recording method capable of forming a visible image (visible image) such as a character, a symbol, a picture, or a photograph on a recording surface on which data is recorded in an optical disc is disclosed (for example, see Patent Document 1). . According to this type of optical disc recording method, the user can visually recognize information related to data recorded on the optical disc, such as the title of the recorded content, by visually observing the recording surface of the optical disc.

Japanese Patent No. 3846373

  In the conventional optical disc recording method, the data cannot be additionally written, the formation start address and the formation end address are calculated in the empty area, and the image data of the visible image is recorded in the area between these addresses, thereby making the visible image visible. An image is formed. In this case, a visible image is formed at a predetermined position by feed control of a feed motor that moves the optical pickup in the radial direction of the optical disk in the radial direction of the optical disk and by rotation control of a spindle motor that rotates the optical disk in the circumferential direction. . For this reason, the accuracy of the visible image depends on the position accuracy at the time of motor drive control, and image formation can only be performed within the range of the mechanical position accuracy including the accuracy of the motor drive mechanism and the eccentricity of the optical disk. It was.

  The present disclosure has been devised in view of the above-described conventional circumstances, and an object thereof is to provide an optical disc recording apparatus and an optical disc recording method capable of recording highly accurate image information on the recording surface of an optical disc.

  The present disclosure relates to an optical disk recording apparatus that records image information on a recording surface of a disk-shaped recording target medium, a data acquisition unit that acquires bitmap data corresponding to the image information, and information recording as the recording target medium In an optical disk having a wobble on a track, an address information acquisition unit that acquires address information set in the wobble by wobble synchronization, and a recording position determination that determines a recording position on the optical disk on which bitmap data is recorded using the address information There is provided an optical disc recording apparatus comprising: a recording portion that emits a light beam of recording power at a recording position on an optical disc, and forms a recording mark corresponding to bitmap data on a track of the optical disc.

  In addition, the present disclosure is an optical disc recording method for recording image information on a recording surface of a disc-shaped recording target medium by an optical disc recording apparatus, and obtains bitmap data corresponding to the image information to obtain information as a recording target medium. In an optical disk having a wobble on a track to be recorded, address information set in the wobble is acquired by wobble synchronization, and a recording position on the optical disk on which bitmap data is recorded is determined using the address information. An optical disk recording method is provided in which a recording power beam is emitted to form a recording mark corresponding to bitmap data on a track of the optical disk.

  According to the present disclosure, it is possible to record high-precision image information on the recording surface of an optical disc.

1 is a block diagram showing an example of the configuration of an optical disk recording apparatus according to the present embodiment Schematic diagram showing an example of a track configuration of an optical disk used in the present embodiment The perspective view which shows an example of a structure of the recording surface of an optical disk The figure explaining an example of a structure of the address information unit of an optical disk The figure which shows an example of the setting of the recording area of the image information in an optical disk The flowchart which shows the process sequence at the time of recording image information in the optical disk recording method based on this Embodiment The figure which shows the specific example of the calculation process of a mark formation position A diagram showing a specific example of the pattern of recording marks The figure which shows the 1st example of the pattern of the recording mark expressing light and shade The figure which shows the 2nd example of the pattern of the recording mark expressing light and shade The figure which shows the 1st example of the example of a setting of the recording area containing image information The figure which shows the 2nd example of the example of a setting of the recording area containing image information The figure which shows the 1st example of a structure of the recording layer containing an image information recording area. The figure which shows the 2nd example of a structure of the recording layer containing an image information recording area. The figure which shows the 1st example of the image information recorded on the optical disk The figure which shows the 2nd example of the image information recorded on the optical disk

  Hereinafter, each embodiment specifically disclosing an optical disc recording apparatus and an optical disc recording method according to the present disclosure will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art. The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(Schematic configuration of optical disk recording device)
In the optical disk recording apparatus according to the present embodiment, a recording mark is written on the recording surface of an optical disk medium such as a BD (Blu-ray (registered trademark)), DVD, or CD as a disk-shaped recording target medium. Possible write-once or rewritable optical disc media are used. In the present embodiment, it is assumed that the optical disk has wobbles on a track (for example, a groove track) on which information is recorded on the recording surface.

  An optical disk recording device forms recording marks on a recording surface of an optical disk, thereby recording data of various user data such as video data and computer data, and visible images (visible images) such as characters, symbols, photographs, and patterns. The image information can be recorded. The image information is not limited to information that can be seen with the human eye, but also includes information that can be read by an optical reader using predetermined light such as laser light. The optical disc is more preferably a write-once optical disc medium such as BD-R or DVD-R from the viewpoint of the visibility of the image information recorded on the recording surface. The image information recorded on the optical disc is image information that is optically readable by human eyes or by an optical reader or the like when the optical disc is not attached to the optical disc recording apparatus, that is, when the optical disc is not rotated and tracked to a predetermined track. is there.

  FIG. 1 is a block diagram showing an example of the configuration of the optical disc recording apparatus according to the present embodiment. The optical disk recording apparatus includes an optical head 101, a servo control unit 102, a signal generation unit 103, a wobble processing unit 104, an address timing generation unit 105, a data acquisition unit 106, a recording processing unit 107, and a laser driving unit. 108 and a controller 111.

  An optical disc 201 that is a recording medium is mounted on the optical disc recording apparatus. The optical head 101 includes a laser light source, an objective lens, and a photodetector, irradiates the optical disk 201 with a light beam, and receives the light beam reflected by the optical disk 201. The photodetector of the optical head 101 is composed of, for example, four divided photodetectors that are divided into four in the track groove direction (tangential direction, circumferential direction) and radial direction (radial direction) of the optical disc 201, and receives light from the optical disc 201. It is converted into an electric signal having a voltage level indicating information on the amount of reflected light and output.

  The signal generation unit 103 generates a focus error signal, a tracking error signal, a wobble signal, and a full addition signal based on the electrical signals output from the respective divided photodetectors of the optical head 101.

  The total addition signal is a signal obtained by adding all signals from the four divided photodetectors, and is a signal indicating the amount of reflected light of the optical disc itself. The focus error signal is a signal detected by, for example, an astigmatism method. The focus error signal is obtained by adding signals from two pairs of divided photodetectors arranged diagonally in each pair, and further obtaining a difference between the addition signals obtained in each pair.

  The tracking error signal and the wobble signal are signals detected by the push-pull method. The tracking error signal and the wobble signal are obtained by adding signals from two sets of divided photodetectors arranged in the tangential direction, and further obtaining a difference between the added signals obtained in each set. The tracking error signal is generated by extracting a frequency component from 0 Hz to several tens of kHz from the push-pull signal. The wobble signal is generated by extracting a signal component of several tens of kHz to several MHz from the push-pull signal.

  The servo control unit 102 focuses the light spot on the recording surface of the optical disc 201 by driving the objective lens of the optical head 101 in a direction perpendicular to the optical disc 201 so that the focus error signal becomes zero. The servo control unit 102 drives the objective lens of the optical head 101 in the radial direction of the optical disc 201 so that the tracking error signal becomes 0, thereby tracking the light spot on the groove of the recording surface.

  Note that the optical disk recording apparatus can be configured to record on lands and grooves in addition to those recorded on grooves. In this case, the servo control unit 102 tracks the recording light spot on the land or groove.

  The wobble processing unit 104 processes the wobble signal generated by the signal generation unit 103. The wobble processing unit 104 has a function of an address information acquisition unit, generates wobble clocks obtained by multiplying the reproduction signal of the basic wobble part of the optical disk out of the wobble signals, and includes address information including address information serving as cluster position information. Unit (ADIP: ADress In Pre-groove) synchronization (ADIP synchronization) is detected and address information is reproduced.

  The address timing generation unit 105 generates recording processing timing from various signals generated by the wobble processing unit 104 and outputs the timing signal to the recording processing unit 107. At this time, the address timing generation unit 105 uses the target address received from the controller 111.

  In the optical disk recording apparatus, each unit performs the following operations regarding information recording. When recording the user data, the data acquisition unit 106 receives the recorded data of the user data and stores it in the memory, and performs various data conversion processes such as addition of an error correction code and modulation to binary data. When recording image information, the data acquisition unit 106 receives bitmap data of the image information and stores it in a memory, and performs data conversion processing such as polar coordinate conversion as necessary.

  The recording processing unit 107 has a function of a recording position determination unit, and determines a recording position on the optical disc based on the acquired recording data or bitmap data. The recording processing unit 107 outputs a light emission control signal to the laser driving unit 108 based on the recording signal after the data conversion processing according to the timing of the recording target address generated by the address timing generation unit 105 and determines The light emission command of the light beam of the recording power corresponding to the recorded position is performed. The laser drive unit 108 has a function of a mark recording unit, drives the laser light source of the optical head 101 according to the light emission control signal, and emits a light beam of recording power from the optical head 101.

  By the above recording operation, a recording mark is formed on the recording surface of the optical disc 201. The recording mark is formed for each channel bit in the cluster in the cluster, which is a data recording unit of the optical disc 201, in accordance with “0” and “1” of the recording information.

  When the optical disc 201 is a BD, the recording mark has a mark length of 2T to 9T, where T is the channel bit length. In this case, the shortest mark length of the recording mark is 2T.

(Schematic configuration of optical disc)
FIG. 2 is a schematic diagram showing an example of a track configuration of the optical disk used in the present embodiment. Here, an example of the configuration of the optical disc 201 used as a recording medium in the optical disc recording apparatus of the present embodiment will be described below.

  The optical disc 201 has a groove track (hereinafter also simply referred to as “groove”) 202 formed on a recording surface 210 in a spiral shape. A land track (hereinafter also simply referred to as “land”) 203 is formed in a spiral shape in a region sandwiched between the grooves 202 formed in a spiral shape. The optical disc 201 can record user data or image information in the groove 202. That is, the groove 202 can be used as a recording track. The optical disc 201 may be capable of recording user data or image information in both the groove 202 and the land 203.

  The groove 202 is divided into a plurality of units for each predetermined length in the track groove direction (circumferential direction). The unit of this divided groove 202 forms an address information unit (ADIP) 204. The ADIP 204 has one piece of address information for the unit area of the optical disc 201. The ADIP 204 has a synchronization area 205 at the head, and has an address information area 206 following the synchronization area 205. The ADIP 204 further includes a plurality of ADIP units (AU) 233.

  FIG. 3 is a perspective view showing an example of the configuration of the recording surface of the optical disk, and is an enlarged view of a part of the recording surface.

  The groove 202 is formed by transferring a portion formed as a groove on the stamper onto the recording surface when the disk is manufactured. The groove 202 is located on the side close to the light source of the optical head 101. When the grooves are formed on the stamper, the disk manufacturing apparatus is formed with a constant beam intensity, so that the groove width is made substantially constant. Therefore, the groove 202 in the optical disc 201 formed by transferring the groove on the stamper is formed with a substantially constant width, and the track width is substantially constant over the entire surface of the optical disc 201. A land 203 exists between the grooves 202.

  Most of the groove 202 and the land 203 meander at a constant period. The meander of this track is wobble. In the case where the light spot 221 follows the groove 202, the wobble is formed with a cycle shorter than the reaction speed at the time of following. For this reason, displacement occurs in the positional relationship between the light spot 221 and the groove 202, and the shape of the wobble can be detected by optically detecting the displacement and converting it into an electrical signal.

  In wobble detection, a clock synchronized with the detection signal is generated. This clock is used to detect the physical length and linear velocity in the optical disc 201. Alternatively, this clock can be used for reproducing the sub information recorded by changing the wobble shape. In the optical disk medium in the present embodiment, address information is recorded by wobble. Thus, detecting the wobble shape in synchronization with the wobble period formed on the track of the optical disc 201 is referred to as “wobble synchronization”.

  FIG. 4 is a diagram for explaining an example of the configuration of the address information unit (ADIP) of the optical disc.

  The ADIP 204 includes a predetermined number of ADIP units 233. In FIG. 4, for convenience of explanation, as shown in FIG. 2, the ADIP unit 233 originally arranged in the continuous ADIP 204 area is divided for each ADIP unit 233 and described in parallel. Most of the ADIP 204 is composed of a basic wobble 232. The shape of the basic wobble 232 corresponds to, for example, a waveform of one cycle of + cos (ωt). The basic wobble 232 has a waveform shape such that the maximum inner circumference displacement, the maximum outer circumference displacement, and the maximum inner circumference displacement change in one cycle.

  In ADIP 204, the part other than the basic wobble 232 is composed of wobbles having the same period as one period of the basic wobble 232. Hereinafter, one cycle of the basic wobble 232 is referred to as a “wobble cycle”. In the illustrated example, the ADIP unit 233 is configured with 56 wobble cycles.

  In the first three wobble periods of the ADIP unit 233, an MSK (Minimum Shift Keying) mark 231 indicating an ADIP unit break is arranged. For example, the MSK mark 231 is configured by connecting wobbles each having a waveform of + cos (1.5 ωt), −cos (ωt), and −cos (1.5 ωt) by one wobble period. The wobble represented by the waveform of -cos (ωt) arranged second in the MSK mark 231 has a shape whose phase is inverted with respect to the basic wobble 232. Therefore, the position of the MSK mark 231 can be detected by performing phase detection from a signal synchronized with the basic wobble 232.

  The ADIP unit 233 includes those included in the synchronization area 205 of the ADIP 204 and those included in the address information area 206 of the ADIP 204. The ADIP unit 233 has a specific pattern for each given function in the remaining 53 wobble periods following the MSK mark 231.

  First, the ADIP unit 233 included in the synchronization area 205 of the ADIP 204 will be described. In the synchronization area 205, a monotone ADIP unit 234, a first synchronization ADIP unit 235, a second synchronization ADIP unit 236, a third synchronization ADIP unit 237, and a fourth synchronization ADIP unit 238 are arranged.

  The monotone ADIP unit 234 is configured only by the basic wobble 232 except for the leading MSK mark 231. This is to stably generate a clock synchronized with the wobble. The first synchronous ADIP unit 235, the second synchronous ADIP unit 236, the third synchronous ADIP unit 237, and the fourth synchronous ADIP unit 238 are for specifying a position in the ADIP 204. These are arranged near the top of the ADIP 204. There are no other ADIP units of the same pattern in the ADIP 204.

  Next, the ADIP unit 303 included in the address information area 206 of the ADIP 204 will be described. In the address information area 206, a monotone ADIP unit 234 and an address information ADIP unit 239 are arranged.

  The address information area 206 includes, for example, one monotone ADIP unit 234 and four address information ADIP units 239 as one unit and these 15 units.

  The address information ADIP unit 239 has 1-bit information. The address information area 206 as a whole has 60 bits of information by 75 ADIP units (ie, 60 address information ADIP units 239). The address information ADIP unit 239 records 1 bit in the address information wobble 240. The 60-bit information includes not only address information which is physical position information in the optical disc, but also layer information in a multilayer disc, information on conditions for recording on the optical disc, sub-information such as copyright information, and the like. An error correction / error detection code for the information may be included.

  The address information ADIP unit 239 includes an MSK mark 231, a basic wobble 232, and an address information wobble 240. The address information ADIP unit 239 has an MSK mark 231 in the first three wobble periods. Subsequent 27 wobble periods have a basic wobble 232. Further, the address information wobble 240 is provided in the subsequent 26 wobble cycle. The address information wobble 240 is formed based on the address information and expresses “0” and “1” of the address information. Therefore, by detecting the wobble shape of the address information wobble 240 in synchronization with the wobble cycle, it is possible to acquire address information by wobble synchronization.

  When the optical disc 201 is a BD, the address information wobble 240 has a shape using STW (Saw Tooth Wobble) in a form multiplexed with the MSK. Unlike the MSK, the STW signal energy is spatially distributed and is detected by integration, so that it is resistant to partial defects. The address information wobble 240 can detect address information more robust by using both MSK and STW.

(Image information recording area setting)
Next, an outline of setting a recording area when recording image information on the recording surface of the optical disc will be described.

  FIG. 5 is a diagram showing an example of setting of a recording area for image information on the optical disc. In the optical disc 201, the user data recording area is a user data recording area 251, and the image information recording area is an image information recording area 252. In the illustrated example, an image information recording area 252 is set on the outer periphery of the optical disc 201.

  When recording image information on the recording surface of the optical disc 201, an image information recording area 252 is set on the outer periphery of the recording surface as a disc format. At this time, the start position Ri0 and the end position Ri1 of the image information recording area 252 are set based on the address information of the optical disc 201. In the illustrated example, it is assumed that the remaining inner peripheral area of the recording surface is set as the user data recording area 251.

  Disk radial direction from the start position (the innermost track position of the disk recording area) Rd0 to the end position (start position Ri0 of the image information recording area 252) of the user data recording area 251 (hereinafter also simply referred to as “radial direction”) Is rd, and the length of the image information recording area 252 in the radial direction from the start position Ri0 to the end position Ri1 is ri. These radial lengths ri and rd are obtained from the track pitch (track-to-track spacing) Tp and the number of tracks in each region.

  The image information recording area 252 may be set in advance so as to secure the image information recording area 252 according to the disk format of the optical disk 201, for example, when the disk is formatted, or when image information is recorded. The recording area may be set each time. When the optical disc 201 is a BD or the like, the recording area can be arbitrarily set.

(Image information recording operation)
Next, the operation when recording image information on the recording surface of the optical disc in the optical disc recording apparatus of the present embodiment will be described.

  FIG. 6 is a flowchart showing a processing procedure when image information is recorded in the optical disc recording method according to the present embodiment.

  In the optical disk recording apparatus, the data acquisition unit 106 acquires bitmap data of image information and stores it in a memory (S11). Bitmap data of image information inputs image data to be recorded based on user instructions, generates image data for recording by user operation, inputs image data to be recorded transmitted from the outside, It can be obtained by various methods. At this time, various software programs such as application software for creating external image information, application software for selecting and inputting bitmap data, and interface software for receiving bitmap data may be used.

  The image information is, for example, various information that can be read visually or by an optical reading device, such as characters, symbols, images, photographs, patterns, patterns, two-dimensional codes such as QR codes (registered trademark), bar codes, watermark patterns, etc. May be used. Further, the image information recorded on the optical disc is not limited to a black and white binary image, and a gray scale gradation can be expressed by forming a halftone dot using a dot pattern.

  Next, according to circumstances, the optical disk recording apparatus performs polar coordinate conversion of bitmap data as data conversion processing in the data acquisition unit 106 (S12). In the polar coordinate conversion process, the data acquisition unit 106 converts XY orthogonal coordinates to r-θ polar coordinates. For example, when the bitmap data is an image such as a photograph or a code pattern such as a two-dimensional code, the image information recorded on the optical disc may be difficult to visually recognize. Converts θ polar coordinates. In calculating the recording start position, mark forming position, recording end position, and the like of bitmap data on an optical disc, polar coordinates are more easily calculated, and therefore bitmap data is preferably converted into polar coordinate representation. If the bitmap data is a character, it can be recognized sufficiently even if it is regarded as X → r, Y → θ and the XY orthogonal coordinates are treated as r−θ polar coordinates without performing polar coordinate conversion. Polar coordinate conversion may not be performed.

  Subsequently, the optical disk recording apparatus calculates the recording start position of the recording mark on the recording surface of the optical disk as an example of the recording position based on the bitmap data of the image information in the recording processing unit 107 (S13). In the calculation process of the recording start position, in the image information recording area 252 set as described above, the position R in the radial direction and the circumferential direction (track) are set as the start positions for forming recording marks in accordance with the bitmap data to be recorded. A value expressed by the position θ in the groove direction) is calculated. For the disk radial direction, the position R in the radial direction is calculated by obtaining the number of tracks from the reference track based on the address information of the recording area. For the circumferential direction, the circumferential position θ is calculated by obtaining the number of clusters from the reference position (reference cluster) of the corresponding track using the cluster which is the data recording unit based on the address information of the recording area. . As an example of the recording position, the recording end position may be calculated together with the recording start position of the recording mark.

  Then, the optical disk recording apparatus calculates the formation position (mark formation position) of the recording mark formed corresponding to the image to be recorded, as an example of the recording position, in the recording processing unit 107 based on the bitmap data of the image information. (S14). In the mark formation position calculation process, a value represented by the cluster address and the number of channel bits in the cluster is calculated as the mark formation position in accordance with the bitmap data to be recorded. A specific example of the mark formation position calculation process will be described later.

  Next, the optical disc recording apparatus forms a recording mark according to the recording mark formation position calculated corresponding to the bitmap data (S15). In the recording mark formation process, the recording processing unit 107 generates a light emission control signal corresponding to the mark formation position, and the laser driving unit 108 drives the laser light source of the optical head 101 according to the light emission control signal. A light beam of recording power is emitted. As a result, a recording mark is formed at a predetermined mark formation position on the recording surface of the optical disc 201 in a track unit and a channel bit unit, and highly accurate image information based on the accuracy of the channel bit is expressed on the track.

(Specific examples of recording marks)
FIG. 7 is a diagram illustrating a specific example of the mark formation position calculation process. FIG. 7 is a diagram schematically showing the recording surface of the optical disc 201 and representing a two-dimensional plane in polar coordinate representation, where the horizontal axis direction is indicated by a circumferential position θ, and the vertical axis direction is indicated by a radial position R. ing. The radial position R corresponds to a track, and the numbers (1000, 1001,...) Described in each track represent the addresses of the clusters. Here, a specific example when the optical disc 201 is a BD will be described.

  FIG. 7 shows an area Aw where a recording mark is formed when a binary image having a black square shape is formed. The colors of R = Rs to Re and θ = θs to θe are changed according to the bitmap data. This shows an example of forming (drawing) an image that fills the area Aw. Hereinafter, the recording mark formed on the recording surface is also simply referred to as “mark”.

  First, a method for determining a track on which a mark for obtaining an image of the area Aw will be described. The starting position of the reference cluster is θ = 0, R = R0, and the track pitch (interval between tracks) is Tp. If the number of tracks from the reference cluster position R0 to the recording start position Rs is Ts in the disk radial direction, Ts is an integer part of (Rs−R0) ÷ Tp. Further, when the number of tracks from the reference cluster position R0 to the recording end position Re is Te, Te is an integer part of (Re-R0) / Tp. Thus, marks are formed from the reference cluster to the Tsth track to the Teth track. Here, it is assumed that the track having the reference cluster is the 0th track.

  Next, a method for calculating a position where θ = θn in the circumferential direction in the Tn-th track will be described. First, the position of θ = 0 of the Tn-th track serving as the reference position is obtained. The reference position of the Tn-th track is obtained by calculating the number of clusters from the reference cluster. Assuming that the number of clusters from the reference cluster to the position θn is Cn, Cn is the area of the donut shape from the position R0 in the radial direction of the reference cluster to (R0 + Tn * Tp), as shown in the following equation. It is represented by a value divided by the area (Tp * cluster length).

Cn = (PI * (R0 + Tn * Tp) ^ 2-PI * R0 ^ 2) / (Tp * Lc)
... (1)
Here, * is a multiplication operator, ^ is a power operator, PI is a pi, and Lc is a physical length (cluster length) of one cluster.

  In the above equation (1), the integer part of the calculation result of Cn indicates the number of clusters of the number of clusters from the reference cluster, and the fractional part multiplied by the number of channel bits of one cluster is the number of channel bits in the cluster. The number of channel bits Pθ0 is shown. Here, the reference cluster is the 0th cluster.

  Since the radius Rn of the Tn-th track is Rn = (R0 + Tn * Tp), assuming that the position where θ = θn is Ln, the following equation is obtained.

    Ln = (R0 + Tn * Tp) * 2 * PI * θ / (2 * PI) (2)

  The position Ln indicates the physical length from θ = 0 to θn, and when this is converted into the number of channel bits Nch, the following equation is obtained.

Nch = Ln / Lch (3)
Here, Lch is the physical length (channel length) of one channel bit.

  By adding this channel bit number Nch to the channel bit position Pθ0 at which θ = 0, the channel bit position Pθn at which θ = θn is obtained. As a result, it is possible to calculate the number of channel bits in which cluster.

    Pθn = Pθ0 + Nch (4)

  In this way, the track, cluster and channel bits forming the mark are determined by calculation.

  FIG. 8 is a diagram showing a specific example of a recording mark pattern. FIG. 8 shows an example of a recording mark actually formed corresponding to FIG. In this case, a mark Mi is formed continuously from the track T1 corresponding to the start position Rs in the radial direction to the track T5 corresponding to the end position Re, in each track from the start position θs in the circumferential direction to the end position θe. . An image that fills the region Aw is expressed by the mark Mi formed in this way, and a visible rectangular image can be recorded.

In the case of the optical disc 201 in the BD format, standard values are as follows.
Starting position of the reference cluster in the radial direction: R0 = 24.0 [mm]
Track pitch: Tp = 0.32 [μm]
Physical length of one channel bit: Lch = 74.5 [nm]
Number of channel bits in one cluster: Ncl = 1932 * 498 = 96136
However, at least two of R0, Tp, and Lch need to use values that are finely adjusted according to the individual optical disk to be used. In the case of the BD format, the number of tracks is about 100,000, and therefore, a significant number of finely adjusted values is required to be 7 digits or more.

  Therefore, when the optical disc 201 is a BD, a recording mark can be formed with an accuracy of 0.32 μm corresponding to the track pitch Tp in the radial direction. In the circumferential direction, a recording mark can be formed with an accuracy of 74.5 nm corresponding to a physical length Lch (corresponding to 1T) of one channel bit. That is, highly accurate image information can be recorded with the accuracy of the track pitch of the optical disc 201. In addition, a large amount of information can be recorded in a small area.

  In addition, when recording on both the land and the groove instead of recording only on the groove of the optical disc 201, it is also possible to record the image information with an accuracy of half the track pitch (in the case of BD, 0.16 μm). It is. Further, if the optical disc has a narrower track pitch, finer image information can be drawn. Further, in the circumferential direction, the start end of the mark forming position can be controlled by dividing 1T by several tens of minutes.

  FIG. 9 is a diagram illustrating a first example of a recording mark pattern expressing light and shade. FIG. 9 shows an example of a recording mark that expresses a portion corresponding to the area Aw in FIG. 7 with an image having grayscale shading. In the first example, gray scale density is expressed by forming a mark Mi1 having a space in part instead of a continuous mark. In this case, the density can be adjusted by the ratio of the mark to be recorded and the space. Also, even for recorded marks that show the same density with the same ratio of mark and space, different patterns can be formed by changing the distribution of mark and space, and different information depending on the pattern You can also.

  FIG. 10 is a diagram illustrating a second example of a recording mark pattern expressing light and shade. FIG. 9 shows another example of a recording mark that expresses a portion corresponding to the area Aw in FIG. 7 with an image having grayscale shading. In the second example, the grayscale density is expressed by forming the mark Mi2 on a part of the thinned out track instead of the continuous track. In this case, the density can be adjusted by the thinning rate of the recording track. Also, even for recording marks that represent the same density with the same thinning rate of tracks, different patterns can be formed by changing the distribution of thinned tracks, and different information can be given depending on the patterns. .

  It is also possible to combine the first example of FIG. 9 and the second example of FIG. 10 to express an image having grayscale shading by allocating marks and spaces to be recorded and thinning out the tracks.

  When recording bitmap data of image information, as shown in FIGS. 8 to 10, the positions of the recording marks in the circumferential direction are aligned within a predetermined range along the radial direction of the disk. At this time, the mark formation positions are aligned in a predetermined pattern in the disk radial direction, such as continuous tracks as shown in FIGS. 8 and 9, and continuous tracks every several tracks as shown in FIG. 10 (every other track in the illustrated example). Thereby, image information that can be read by the aligned recording marks can be formed instead of the random recording marks of the user data.

(Setting example of recording area including image information)
FIG. 11A is a diagram illustrating a first example of setting of a recording area including image information. FIG. 11B is a diagram illustrating a second example of setting a recording area including image information. 11A and 11B show examples in which the recording area of the recording surface is divided into four areas A1 to A4 as the recording format of the optical disc 201. FIG.

  The first example shown in FIG. 11A is an example in which the area A4 on the outer periphery of the disc is set as the image information recording area 252. In this case, the area A1 on the inner periphery side of the optical disc is set as the user data recording area 251 and user data is recorded. Also, image information is recorded in the image information recording area 252 of the outer peripheral area A4.

  The second example shown in FIG. 11B is an example in which the area A1 in the inner periphery of the disc is set as the image information recording area 252. In this case, the area A2 on the outer peripheral side of the optical disc is set as the user data recording area 251 and user data is recorded. Further, image information is recorded in the image information recording area 252 of the area A1 on the inner peripheral side.

  The settings of the user data recording area 251 and the image information recording area 252 may be set in advance before information recording in the optical disk recording apparatus, for example, at the time of disk formatting, or may be set each time the recording operation is executed. Can also be done. When the optical disc 201 is a BD or the like, the recording area can be arbitrarily set.

  Depending on the use of the optical disk, it is also possible to set the image information recording area 252 in the areas A2, A3, etc. in the middle part of the recording surface, and record the image information between the user data recording areas.

(Configuration example of recording layer of optical disc)
FIG. 12A is a diagram illustrating a first example of a configuration of a recording layer including an image information recording area. FIG. 12B is a diagram illustrating a second example of the configuration of the recording layer including the image information recording area. 12A and 12B schematically show the cross section of the recording layer of the optical disc 201. FIG.

  The first example shown in FIG. 12A is a single-layer optical disc, in which a user data recording area 251 is arranged on the inner periphery of the disc, and an image information recording area 252 is arranged on the outer periphery of the disc. The second example shown in FIG. 12B is a two-layer optical disc, and in each of the first layer RL1 and the second layer RL2, a user data recording area 251 is disposed on the inner periphery of the disc, and image information recording is performed on the outer periphery of the disc. A region 252 is arranged. As described above, even in a multi-layer optical disc, image information can be recorded by setting the image information recording area 252 on the recording surface of each layer.

  Note that the image information recording area 252 is not limited to the outer peripheral portion of the optical disc, but can be set at an arbitrary position such as an inner peripheral portion to record image information. In the case of a multilayer optical disc, it is also possible to set the image information recording area 252 at an arbitrary position of an arbitrary recording layer and record image information.

(Example of recording optical disk image information)
FIG. 13A is a diagram showing a first example of image information recorded on an optical disc. FIG. 13B is a diagram showing a second example of image information recorded on an optical disc. 13A and 13B show the surface of the recording layer of the optical disc 201. FIG.

  In the first example shown in FIG. 13A, an image information recording area 252 is set on the outer periphery of the recording surface 210 of the optical disc 201, and image information 271A including characters, a watermark pattern, and a photograph is recorded.

  In the second example shown in FIG. 13B, an image information recording area 252 is set on the inner peripheral portion of the recording surface 210 of the optical disc 201, and image information 271B including characters, QR code (registered trademark), and images is recorded.

  The image information can form images based on various bitmap data in the image information recording area 252 set at an arbitrary position according to the disc format on the recording surface 210 of the optical disc 201. The image information can be recorded after the user data is recorded in the user data recording area 251 or can be recorded before the user data is recorded.

  Further, the image information recorded on the optical disc 201 can be optically read by the optical disc alone, and can be read without rotating the optical disc without being mounted on the optical disc recording apparatus. As the image information, various kinds of information can be recorded such as information that can be read with the naked eye of human eyes, information that can be read by an optical reader using reference light such as laser light of a specific wavelength, and the like.

  The image information can also be used to determine the authenticity of user data recorded on the optical disc 201 by providing sub-information such as copyright information and serial information to a pattern such as a watermark pattern. In this case, it is set to have specific sub information according to the pattern mode, and the sub information by the pattern is embedded in the image information. The user can read the sub-information by detecting a pattern embedded in the image information by an optical reader or the like, and determine whether or not the user data is illegally copied or falsified.

  As described above, the optical disk recording apparatus of the present embodiment is an optical disk recording apparatus that records image information on a recording surface of a disk-shaped recording target medium, and obtains bitmap data corresponding to the image information. Unit 106, wobble processing unit 104 as an address information acquisition unit for acquiring address information set in wobble by wobble synchronization in optical disc 201 having wobbles in a track on which information is recorded as a recording target medium, and address information is used. A recording processing unit 107 as a recording position determining unit for determining a recording position on the optical disk on which bitmap data is recorded, and a light beam of recording power is emitted to the recording position on the optical disk, and a bitmap is recorded on the track of the optical disk 201. Mark recording that forms recording marks corresponding to data It includes a laser drive unit 108 as a part, a.

  With the above configuration, by determining the recording position using the address information of the track, it is possible to form a recording mark corresponding to the bitmap data representing the image information with the positional accuracy of the track and address information on the optical disc. Therefore, highly accurate image information can be recorded on the recording surface of the optical disc.

  In the optical disc recording apparatus, the recording processing unit 107 determines a mark formation position for forming a recording mark as a recording position for recording bitmap data. Thereby, the recording mark corresponding to the bitmap data representing the image information can be formed according to the positional accuracy of the recording mark used for recording and reproduction on the optical disc. Specifically, high-accuracy bitmap data can be recorded on an optical disc by the accuracy of the track pitch in the radial direction of the disc and the accuracy of the physical length of 1 channel bit and the shortest length (2T) of the recording mark in the circumferential direction. . Therefore, highly accurate image information can be recorded on the recording surface of the optical disc.

  Further, in the optical disc recording apparatus, the recording processing unit 107 determines the mark formation position so that the positions of the recording marks in the circumferential direction are aligned within a predetermined range in the radial direction of the optical disc 201. As a result, optically readable image information such as characters, photographs, and patterns can be formed on the recording surface of the optical disc 201.

  In the optical disk recording apparatus, the recording processing unit 107 determines the mark formation position in units of cluster addresses and channel bits based on the cluster address on the optical disk 201 and the number of channel bits in the cluster. As a result, the recording position can be determined and the recording mark can be formed in units of the cluster address and channel bit on the optical disc, so that highly accurate image information can be recorded.

  In the optical disc recording apparatus, the recording processing unit 107 sets an image information recording area 252 for recording image information on the optical disc 201 and calculates a recording position in the image information recording area 252. Thereby, at the time of recording image information, the image information recording area 252 is set each time, and a recording mark corresponding to bitmap data representing the image information can be recorded.

  In the optical disc recording apparatus, the recording processing unit 107 calculates a recording position in the image information recording area 252 set in the optical disc 201. As a result, a recording mark corresponding to the bitmap data representing the image information can be recorded in the image information recording area 252 set in advance when the optical disc 201 is formatted.

  Further, in the optical disc recording apparatus, the image information is information on gradation binary or gradation expression including at least one of a character, a symbol, an image, a photograph, a pattern, a pattern, a two-dimensional code, a barcode, and a watermark pattern. It is. As a result, various kinds of image information of grayscale (black and white binary) or gradation expression (grayscale) can be recorded with high accuracy as the image information. For example, a character, a symbol, an image, a photograph, a pattern, a pattern, or the like can be read by a human eye or read by an optical reading device. Information (contents, title, data type, author, creation date, etc.) of recorded data recorded as user data can be easily confirmed from the image information recorded on the optical disc. In addition, a pattern, a two-dimensional code (QR code (registered trademark)), a barcode, a watermark pattern, and the like can be read by an optical reader. By giving sub-information such as copyright information and serial information to the two-dimensional code or watermark pattern, it is possible to perform individual determination, authenticity determination, and the like of the optical disk and the recorded data.

  The optical disc recording method of the present embodiment is an optical disc recording method for recording image information on a recording surface of a disc-shaped recording target medium by an optical disc recording apparatus, and a bit corresponding to image information in a data acquisition unit 106. In the optical disc 201 having the wobble in the track on which the map data is recorded and information is recorded as the recording target medium, the address information set in the wobble by the wobble processing unit 104 is acquired by wobble synchronization, and the address in the recording processing unit 107 Using the information, the recording position on the optical disk where bitmap data is recorded is determined, and the laser drive unit 108 emits a light beam of recording power to the recording position on the optical disk. Corresponding recording marks are formed.

  While various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood. In addition, the constituent elements in the above-described embodiment may be arbitrarily combined without departing from the spirit of the invention.

  The present disclosure is useful as an optical disc recording apparatus and an optical disc recording method capable of recording high-precision image information on the recording surface of an optical disc.

Reference Signs List 101 optical head 102 servo control unit 103 signal generation unit 104 wobble processing unit 105 address timing generation unit 106 data acquisition unit 107 recording processing unit 108 laser drive unit 111 controller 201 optical disk 202 groove track (groove)
203 Land Track (Land)
204 ADIP
205 synchronization area 206 address information area 210 recording surface 232 basic wobble 239 address information ADIP unit 240 address information wobble 251 user data recording area 252 image information recording area 271A, 271B image information

Claims (8)

An optical disk recording apparatus for recording image information on a recording surface of a disk-shaped recording target medium,
A data acquisition unit for acquiring bitmap data corresponding to the image information;
In an optical disk having a wobble on a track on which information is recorded as the recording target medium, an address information acquisition unit that acquires address information set in the wobble by wobble synchronization;
Using the address information, a recording position determining unit that determines a recording position on the optical disk for recording the bitmap data;
A mark recording unit that emits a light beam of recording power at a recording position on the optical disc and forms a recording mark corresponding to the bitmap data on a track of the optical disc;
An optical disc recording apparatus comprising: The optical disk recording apparatus according to claim 1,
The recording position determining unit determines a mark forming position for forming the recording mark as the recording position;
Optical disk recording device. The optical disk recording apparatus according to claim 2,
The recording position determining unit determines the mark forming position so that the positions of the recording marks in the circumferential direction are aligned within a predetermined range in the radial direction of the optical disc;
Optical disk recording device. The optical disk recording apparatus according to claim 2,
The recording position determination unit determines the mark formation position in units of the cluster address and the channel bit according to a cluster address and the number of channel bits in the cluster on the optical disc;
Optical disk recording device. The optical disk recording apparatus according to claim 1,
The recording position determining unit sets an image information recording area for recording the image information on the optical disc, and calculates the recording position in the image information recording area;
Optical disk recording device. The optical disk recording apparatus according to claim 1,
The recording position determining unit calculates the recording position in an image information recording area set in the optical disc;
Optical disk recording device. The optical disk recording apparatus according to claim 1,
The image information is information of gradation binary or gradation expression including at least one of a character, a symbol, an image, a photograph, a pattern, a pattern, a two-dimensional code, a barcode, and a watermark pattern.
Optical disk recording device. An optical disk recording method for recording image information on a recording surface of a disk-shaped recording target medium by an optical disk recording apparatus,
Obtaining bitmap data corresponding to the image information;
In an optical disc having wobbles in a track on which information is recorded as the recording target medium, the address information set in the wobble is acquired by wobble synchronization,
Using the address information, determine a recording position on the optical disk for recording the bitmap data,
A light beam of recording power is emitted at a recording position on the optical disc, and a recording mark corresponding to the bitmap data is formed on a track of the optical disc.
Optical disc recording method.