JP2007073122A - Barcode recording device and barcode recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a barcode recording device and a barcode recording method for recording a barcode mark with good quality of a reproduction signal to a high density optical disk with area recording density of 150 Mbytes/cm<SP>2</SP>or more. <P>SOLUTION: The barcode recording device and the barcode recording method use high output blue semiconductor laser 6a for a light source, form a linear laser spot 9, extending in radius direction of the optical disk, on a recording surface of the optical disk, and emit the laser pulse to be synchronized with rotation of an optical disk 7, and sends the laser spot 9 in the radius direction of the disk. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a barcode recording apparatus and a barcode recording method for forming a barcode-like mark on an optical disk surface by irradiating a laser beam for the purpose of copyright protection and copy protection.

  Currently, some of the DVD media that are in widespread use are bar code-like physics that are completely different from pits (marks) that contain content data (music / video, etc.) on the optical disk recording surface or reflective film surface. The mark is recorded. The bar-code-like physical marks are arranged in the circumferential direction on the inner circumference side of the optical disc and are called BCA (Burst Cutting Area) codes, and include unique information such as disc information and disc ID.

The physical mark is formed by laser light after forming a laminated film such as a reflective film or a recording film in the optical disk manufacturing process, and records an arbitrary mark (data) using a special device such as a BCA code recording device. For this reason, it is very difficult for the user to perform copying.
On the other hand, DVD-RAM and DVD-RW have been commercialized as rewritable DVDs. Phase change materials are used as recording materials for these recording media, and the phase change material (recording film) is irradiated with laser. Thus, the crystallization state is changed, and information is recorded / reproduced by utilizing the change in reflectance due to the change in the crystallization state.

  Examples of documents describing techniques related to a method and an apparatus for recording marks on this phase change type optical disc include Patent Document 1 and Patent Document 2 below, and these documents include a barcode-like physical disk using a semiconductor laser. It is described that the mark part and the other space part are recorded and identified by crystal and non-crystal (as-depo).

Further, there is a DVD-ROM as a read-only DVD, and literatures describing techniques related to a mark recording method and apparatus include, for example, Patent Document 3 and Patent Document 4, and these documents include optical disc manufacturing. A technique is described in which a bar code-like physical mark is formed by irradiating a disk reflection layer with a high-power laser such as a YAG laser after the process of laminating the disk to melt and remove the reflection layer. In addition, the bar code mark portion is formed by processing a low reflectance so as to satisfy a predetermined value, and a practical bar code recording apparatus has a far-red wavelength of 800 nm or more so as to obtain a high output. Generally, an external laser is used as a light source.
JP 2004-127514 A Japanese Patent Application Laid-Open No. 2005-166096 Japanese Patent No. 3144422 JP 2005-11435 A

In recent years, optical DVDs such as HD DVD (high density digital versatile disc) and BD (Blu-ray disc: Blu-ray disc) that exceed 15 GB as a next-generation DVD media have been standardized and partially commercialized. . The recording density of these optical discs exceeds 150 Mbytes / cm ^2, and the greatest feature is that both discs record / reproduce data using a blue laser (wavelength 405 nm). In these next-generation media as well, it is necessary to add a BCA code in the same manner as in the conventional DVD described above.

  However, write-once media composed of materials with high wavelength dependency, such as organic dyes, particularly materials that hardly react at wavelengths other than blue (wavelength 400 nm band) are also appearing as recording materials. (Wavelength is 800 nm or more) There is a problem that a barcode recording apparatus using a laser as a light source cannot perform recording at all, or a high-quality BCA mark reproduction signal that satisfies a predetermined value cannot be obtained even if recording is possible.

  In particular, in a single-sided dual-layer disc having two recording layers, if the laser output is relatively small using a bar code recording device using a far infrared laser as a light source, the bar code cannot be recorded and can be recorded. When the laser output is increased to such a degree, there is a problem that damage may be caused to the other recording layer other than the recording target layer, or the reflective layer may be damaged before the recording material reacts.

  Even when a barcode recording device using a far-infrared laser as a light source can be used to record barcodes on next-generation media, the conventional device requires a large amount of input energy (laser power), so It is necessary to slow down the scanning speed, and further, it is necessary to reduce the feed speed in the radial direction of the recording spot, which causes a problem that the recording time becomes redundant. Although the above-mentioned patent document describes that a mark (BCA code) is recorded using a laser, specific techniques such as a laser wavelength and a laser spot size formed on an optical disk recording film surface are described. It is not disclosed.

An object of the present invention is to eliminate the above-mentioned problems caused by the prior art, and specifically, to record a barcode mark with a good reproduction signal on a next-generation medium having a recording density exceeding 150 Mbytes / cm ^2. A bar code recording apparatus and a bar code recording method that can be used.

  In order to achieve the above object, the present invention irradiates an optical disk recording surface with a laser beam emitted from a semiconductor laser as a laser spot, changes the output of the laser beam in a pulse shape while synchronizing with the rotation angle of the optical disk, and a laser. In the barcode recording apparatus that forms a mark along the circumference of the optical disk by feeding the spot in the radial direction of the disk and moving in a spiral shape, the semiconductor laser has a wavelength (λ) of 400 nm ≦ λ ≦ 410 nm, and The first feature is to emit a laser beam having a film surface laser output (P) of 100 mW ≦ P ≦ 2 W.

  Further, the present invention provides the barcode recording apparatus according to the first feature, further comprising an objective lens that condenses the laser light emitted from the semiconductor laser and forms a linear laser spot on the optical disk recording surface. The spot size is such that the length (L) in the longitudinal direction is 10 μm ≦ L ≦ 250 μm, the length (d) in the short direction is 0.3 μm ≦ d ≦ 3 μm, and the longitudinal direction of the laser spot is The bar code recording apparatus according to any one of the above characteristics, wherein the objective lens having a numerical aperture (NA) of 0.6 ≦ NA ≦ 0.85 and a bar A third feature is provided with a focus control means for performing automatic focus control of a laser spot on a recording layer for recording a code.

  Furthermore, the present invention irradiates the optical disc recording surface with laser light emitted from a semiconductor laser as a laser spot, changes the output of the laser light in pulses while synchronizing with the rotation angle of the optical disc, and changes the laser spot in the disc radial direction. In the barcode recording method of the barcode recording apparatus for forming a mark along the circumference of the optical disc by moving it in a spiral manner, the semiconductor laser has a wavelength (λ) of 400 nm ≦ λ ≦ 410 nm, and A fourth feature is that barcode recording is performed while emitting laser light with a film surface laser output (P) of 100 mW ≦ P ≦ 2 W.

  In the barcode recording method of the fourth feature, an objective lens for condensing laser light emitted from the semiconductor laser and forming a linear laser spot on the optical disk recording surface is provided, and the size of the laser spot is The length in the longitudinal direction (L) is 10 μm ≦ L ≦ 250 μm, the length in the short direction (d) is 0.3 μm ≦ d ≦ 3 μm, and the longitudinal direction of the laser spot is orthogonal to the circumferential direction of the optical disc. In the barcode recording method of any one of the above characteristics, an objective lens having a numerical aperture (NA) of 0.6 ≦ NA ≦ 0.85 is provided. Focus control means for automatically controlling the laser spot on the recording layer for recording the barcode is provided, and the focus control means performs barcode recording while focusing on the optical disk recording surface. And sixth aspect of the.

According to the barcode recording apparatus and method of the present invention, the semiconductor laser emits laser light having a wavelength (λ) of 400 nm ≦ λ ≦ 410 nm and a film surface laser output (P) of 100 mW ≦ P ≦ 2W. The objective lens has a numerical aperture (NA) of 0.6 ≦ NA ≦ 0.85, the length (L) in the longitudinal direction of the laser spot is 10 μm ≦ L ≦ 250 μm, and the length in the short direction. By setting (d) to 0.3 μm ≦ d ≦ 3 μm and arranging the longitudinal direction of the laser spot perpendicular to the circumferential direction of the optical disc, a reproduction signal is transmitted to the next-generation media having a recording density exceeding 150 Mbytes / cm ^2. Good quality barcode marks can be recorded.
The inventors have confirmed that a high-quality BCA mark can be formed under the following conditions for a next-generation write-once medium in which the recording material is composed of an organic dye.
NA = 0.6,
Laser wavelength (λ) = 408 nm,
Longitudinal spot width = 10 μm,
Film surface laser output = 100 mW
Recording speed (scanning speed) = 2-6 m / s

  Hereinafter, a barcode recording apparatus and a barcode recording method according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the arrangement of an initialization laser spot at an arbitrary time during initialization, and is a diagram seen from a direction perpendicular to the surface of a two-layer optical disc. FIG. 2 illustrates a bar code recorded on the optical disc according to this embodiment. 3 is a diagram for explaining a barcode recording apparatus according to an embodiment of the present invention, FIG. 4 is a schematic diagram of a linear spot formed on the recording film surface of an optical disk, and FIG. FIG. 6 is a schematic diagram in which a laser beam is incident on a single-sided dual-layer disc and the recording layer is focused.

<Premise explanation>
First, an optical disc that is an object of barcode recording according to the present invention will be described. The optical disc to which this embodiment is applied can be recorded and reproduced with a blue laser having a recording density per surface exceeding 150 Mbytes / cm ² and a wavelength (λ) of 405 nm. As shown in FIG. A second recording layer 2 and a transparent intermediate layer 3 are sandwiched between the second recording layer 2 and a semi-transparent first recording layer 1 and a recording layer 1 on the recording layer 1. A single-sided, dual-layer optical disc 6 having two recording layers, including a cover layer 5 (or a substrate 5) for protecting the recording layer 1.

  The single-sided dual-layer optical disc 6 can reproduce information recorded on each recording layer 1 or 2 by irradiating the blue laser light 4 from one side, and can record information on each recording layer 1 or 2. Is also possible. The disc is of the write-once type, and the recording material may be tuned for a blue laser and may be either organic dye-based or inorganic. As a feature, recording is possible only with laser light having a high wavelength dependency and a wavelength of 405 nm band.

  In addition, “recording” described in the present application indicates a state similar to a recording mark portion in a drive or recorder, and is a state in which a dye is generally burned (state in which a dye is changed) if it is an organic dye material by laser light irradiation. In the case of an inorganic material, particularly a phase change material, it indicates a state to be crystallized. The “film surface laser output” described in the present application means the value of the laser output irradiated on the recording layer of the optical disc.

  In addition, as shown in FIG. 2, the optical disk recorded by the barcode recording apparatus according to the present application has a plurality of marks (bars and spaces) in the form of a barcode extending radially from the center of rotation of the disk on the inner peripheral side of the optical disk 7. Is formed with a bar code mark 8 along the disk circumferential direction 9a, for example, a BCA code.

<Description of configuration of barcode recording apparatus>
Next, the configuration of the barcode recording apparatus according to the present embodiment will be described. As shown in FIG. 3, the barcode recording apparatus according to the present embodiment is emitted from a high-power blue semiconductor laser 6a that emits laser light having a wavelength (λ) and output power, which will be described later, and the high-power blue semiconductor laser 6a. A laser beam is incident and a linear spot forming optical system 10 for forming a linear laser spot 9 that is long in the radial direction of the disk and a laser beam 28 formed by the linear spot forming optical system 10 are narrowed down. Objective lens 7b, two-layer separation recognition optical system 13 for separating and recognizing two recording layers 11 and 12 and generating a focus servo signal corresponding to each recording layer, and disc surface vibration The double-layer focus control circuit 14 that controls the focusing by moving the objective lens 7b in the direction 7a so that the focus shift does not occur, and the optical disk 27 at a predetermined rotational speed. A spindle motor 15 that is driven to rotate in a direction 78 (reference numeral 15a), a rotary encoder 16 that detects the rotation angle of the disk in accordance with the rotation of the motor 15, and a modulation clock signal based on the rotation angle detected by the encoder 16. Is generated in synchronization with the rotation angle of the disk, and a signal 32 for recording on the disk surface is generated based on the bar code recording buffer data stored in the data buffer 18 and the modulation clock signal. Modulation circuit 19, laser driver circuit 22 for driving the semiconductor laser 6a, carriage 25 for moving the spot 9 focused on the disk recording layer in the disk radial direction 36, focus system / laser system / motor system / carriage A microprocessor that controls the operation of each circuit and the entire system (MP U) 26.

<Description of optical head and recording spot>
The high-power blue semiconductor laser 6a mounted on the optical head 25a has a characteristic that the output wavelength (λ) is [400 nm ≦ λ ≦ 410 nm]. This wavelength is most preferably the same wavelength as the corresponding wavelength 405 nm of the corresponding drive or recorder. If the wavelength is the same as that of the drive or recorder, recording can be performed with high efficiency, and excessive energy can be given to adjacent laminated films other than the target recording film (layer) to reduce adverse effects.

  The high-power blue semiconductor laser 6a has an output characteristic that the film surface laser output is 100 mW or more. The reason for this is that a linear spot having a length of 10 μm or more in the radial direction of the disk is required to efficiently record a bar code. When this linear spot is formed, it is calculated from the recording laser output density. This is because it is practical that the film surface laser output has an output of 100 mW or more. The output value of the high-power blue semiconductor laser 6a in the actual machine is preferably 200 mW or more. The upper limit value of the output is preferably calculated from the upper limit (described later) of the length of the linear spot in the longitudinal direction, and the film surface laser output is preferably 2 W. Therefore, the film surface laser output range in the present invention is preferably 100 mW ≦ P ≦ 2W.

  The objective lens 7b strongly narrows the laser beam output from the high-power blue semiconductor laser 6a as a linear laser spot 9 on the recording film of the optical disc through the linear spot forming optical system 10, and therefore has a numerical aperture (NA) of 0. A characteristic of .6 ≦ NA ≦ 0.85 is preferred.

The reason why the objective lens 7b having a high numerical aperture (NA) of 0.6 ≦ NA ≦ 0.85 is used will be described with reference to FIG.
FIG. 4 is a schematic diagram of a linear spot formed on the recording film of the optical disc 27, and is a view of the optical disc viewed from the surface direction, that is, the laser beam incident direction.

  As shown in FIG. 4, the linear spot in this embodiment scans the linear spot 45 (9) at a scanning speed of 50 relative to the optical disc while rotating the optical disc 27 in the direction of the rotation code 15a. Arranging the longitudinal direction 51 of the linear spot 45 on a straight line 48 extending in a half direction from the center of rotation of the optical disk, that is, in a direction orthogonal to the circumferential direction 49 of the optical disk 27 is most efficient in recording a barcode. It is known.

  In the linear spot in this example, the length in the longitudinal direction (half-value width: L) of the linear spot is 10 μm ≦ L ≦ 250 μm, and the length in the lateral direction (half-value width: d) is 0.3 μm ≦ d ≦ Set to 3 μm. The longitudinal direction 51 preferably has an upper limit of 250 μm in view of the balance between the depth of focus and the mechanical characteristics of the disc, particularly the radial tilt amount, and the lower limit is preferably 10 μm or more in consideration of practicality.

  The length (d) in the short direction of the linear spot is preferably 0.3 μm ≦ d ≦ 3 μm from the relationship between the scanning speed 50 of the laser spot and the quality of the recording state. Further, the laser output intensity distribution in the longitudinal direction is effective in recording a uniform mark in the radial direction by forming the trapezoidal shape 46 having a substantially flat vertex. The laser intensity distribution in the short direction is not particularly defined, but a shape close to the Gaussian distribution 47 is desirable.

  In the present embodiment, the length (L) in the longitudinal direction of the linear spot and the laser output intensity distribution 46 in the longitudinal direction, the length (d) in the lateral direction, and the laser intensity distribution (Gaussian distribution) 47 in the lateral direction are: The high-power blue semiconductor laser 6a, the linear spot forming optical system 10, and the objective lens 7b can be freely set. In order to form the shape of the linear spot, the objective lens 7b In order to strongly narrow down as a linear laser spot 9, the numerical aperture (NA) is preferably 0.6 ≦ NA ≦ 0.85.

<Description of operation>
The operation of the barcode recording apparatus according to the present embodiment will be described with reference mainly to FIGS.
The barcode recording apparatus according to the present embodiment automatically records a barcode by programming set in advance in the MPU 26 with the optical disk 3 to be barcode-recorded mounted on the spindle motor 15. In this operation, first, the spindle motor 15 rotates the disk 27 at a predetermined rotational speed according to an instruction from a motor driver circuit (not shown). The rotation method in this case may be either CLV (Constant Linear Velocity) rotation or CAV (Constant Angular Velocity) rotation. Next, the MPU 26 moves the carriage 25 to the barcode recording radius position on the optical disk 27, causes the laser 6 a to emit light with the bottom power 29 at a level (output value) where recording is not performed, and the two-layer focus control circuit 14 performs barcode processing. Autofocus control is applied to the recording layer.

  Next, in this apparatus, the MPU 26 outputs the barcode data for barcode recording to the data buffer 18, and the serial buffer data 30 output from the data buffer 18 is synchronized with the modulation clock signal 31 in the modulation circuit 19. A signal 32 synchronized with the disk rotation is generated and transmitted to the laser driver circuit 22. The laser driver circuit 22 amplifies the signal 32 and gives an output instruction to the high-power blue semiconductor laser 6a. The blue semiconductor laser 6a starts irradiating a laser output 33 that emits pulses at the same timing as the signal 32.

  As shown in FIG. 5, the laser output 33 is set such that the top power 34 of the laser beam to be output is higher than the output at which the disk recording layer can be optically changed to form the mark portion 37, and the bottom power 29 is The output is set so as not to change optically. In particular, the bottom power 29 is preferably reduced to such an extent that the focus is not lost.

  As described above, the bar code recording apparatus according to the present embodiment synchronizes with the rotation of the optical disk and outputs the same pulse laser 33 every rotation of the disk, while the laser spot 40 cannot be recorded by the carriage 25 at a predetermined feed pitch. By feeding 35 in the radial direction 36, a bar code 39 having a predetermined length can be recorded in the radial direction.

  The recording data 38 for this bar code is, for example, the number “..010011 ..” as shown at the bottom of FIG. 5. The recorded mark portion 37 has a low reflectivity, and other disc surfaces and reflectivities are different. Since it is sufficiently different, reproduction recognition can be performed by a general optical disk drive device or the like.

  The bar code recording apparatus according to the present embodiment has a spot scanning speed (V) 50 determined by the disk rotation speed and the spot radius position, a radial feed (D) 35 per disk rotation, and a laser output (top power P). 34 can be arbitrarily set by a personal computer or the like above the MPU 26. The scanning speed (V) 50 is, for example, (2 m / s) ≦ V ≦ (12 m / s), and the radial feed per disk rotation (D) 35 is, for example, 2 μm / r ≦ D ≦ (longitudinal spot width). It is practical to set the um / r, film surface laser output (top power P) 34 to, for example, 100 mW ≦ V ≦ 2 W, so that there is no unevenness for each recording layer and the barcode reproduction waveform is predetermined. It is possible to select the most balanced condition that satisfies the value and further has a short recording time.

<Explanation of focusing>
Next, laser spot focusing by this apparatus will be described with reference to FIG. FIG. 6 is a schematic diagram focusing on each recording layer of a single-sided dual-layer disc.

  The bar code recording apparatus according to the present embodiment can adjust the focal position 61 to the recording layer 59 or 60 for bar code recording of the optical disc as shown in FIG. The shape of the laser spot formed on the recording film does not change due to disturbance, and a laser spot having a predetermined laser power density can always be secured in the recording layer.

  Furthermore, the barcode recording apparatus according to the present example uses the high NA objective lens 58 so that n is the refractive index of the protective layer or intermediate layer, and θ is the angle formed between the normal line perpendicular to the recording surface and the incident light beam. The incident angle θ [θ = sin−1 (NA / n)] can be increased. That is, the laser spot area change greatly with respect to the optical axis direction 62 shown in FIG. 6, and the laser power density can be drastically reduced at a position slightly deviated from the in-focus position 61.

  Therefore, in the present embodiment, when recording is performed while focusing on the recording layer to be recorded with barcode, the recording is not performed up to the other adjacent recording layer at the same time, and the barcode recording 63 is performed only on the target recording layer. It is possible to record different barcode data separately on both recording layers. It is also possible to record bar codes of different data successively by recording the bar code on one recording layer and then moving the focus to the other recording layer by focus jump.

  In the above-described embodiment, the single-sided dual-layer disc has been described. However, the present invention is not limited to two-layers, and the same effect can be obtained with a single-sided multilayer disc having three or more layers. Of course, there is no problem even with a single-layer disc, and the same effect can be obtained. In the above embodiment, bar code recording is shown on the inner periphery of the disc. However, the bar code may be provided on the middle or outer periphery without being limited to the inner periphery of the disc. Furthermore, in the previous embodiment, an example in which a strong laser beam (top power) is irradiated to make the mark portion have a low reflectivity has been described. However, the present invention is not limited to this, and marks arranged in the circumferential direction of the disc. Further, a configuration may be adopted in which strong laser light (top power) is irradiated between the marks, that is, the space portion to reduce the reflectance of the space portion.

  In the above-described embodiment, an example has been described in which an optical disc (high to low) having a recording characteristic in which the reflectance decreases when irradiated with strong laser light (top power), but the present invention is not limited thereto. Instead, an optical disc (Low to high) having a recording characteristic that increases the reflectance when irradiated with strong laser light (top power) can be recorded. That is, in the above-described embodiment, by irradiating a strong laser beam (top power) to the space portion, the reflectance of the space portion can be increased, and a strong laser beam is applied to the mark portion of the high to low disc as a reproduction signal. A signal having the same polarity as that obtained when recording is performed can be obtained.

As described above, in the barcode recording apparatus according to the present embodiment, since the reflection layer material such as a silver alloy or an aluminum alloy generally used for an optical disk has an increased absorptance in a blue band (wavelength: 400 nm band), It is also effective for ROM type bar code (BCA code) recording that melts and removes. Further, a barcode mark with a good reproduction signal can be recorded on a next-generation medium having a recording density exceeding 150 Mbytes / cm ² .

The figure which shows arrangement | positioning of the initialization laser spot in the arbitrary time during initialization execution. The figure for demonstrating the barcode recorded on the optical disk by this embodiment. The figure for demonstrating the barcode recording device by one Embodiment of this invention. The schematic diagram of the linear spot formed on the recording film surface of an optical disk. The time chart figure of the barcode recording method by this embodiment. FIG. 3 is a schematic diagram in which laser light is incident on a surface double-layer disc and a recording layer is focused.

Explanation of symbols

1: recording layer, 2: recording layer, 3: intermediate layer, 4: blue laser light, 5: cover layer, 6: layer optical disk, 6a: high-power blue semiconductor laser, 7: optical disk, 7b: objective lens, 8: Bar code mark, 9: Laser spot, 9a: Disk circumferential direction, 10: Linear spot forming optical system, 11: Recording layer, 12: Recording layer, 13: Two-layer separation recognition optical system, 14: Two-layer focus control circuit 15: spindle motor 16: rotary encoder 17: clock synchronization circuit 18: data buffer 19: modulation circuit 22: laser driver circuit 25: carriage 25a: optical head 27: optical disk 28: laser light 29: Bottom power, 30: Serial buffer data, 31: Clock signal for modulation, 32: Signal, 33: Laser output, 34: Top power, 35 Pitch, 36: disk radial direction, 37: mark portion, 38: recording data, 39: barcode, 40: laser spot, 45: linear spot, 46: trapezoidal shape, 46: laser output intensity distribution, 47: Gaussian distribution 48: straight line, 49: circumferential direction, 50: scanning speed, 51: longitudinal direction, 58: objective lens, 59: recording layer, 61: focal position, 61: in-focus position, 62: optical axis direction, 63 : Bar code recording.

Claims (6)

Laser light emitted from a semiconductor laser is irradiated onto the optical disk recording surface as a laser spot, and the output of the laser light is changed in pulses while synchronizing with the rotation angle of the optical disk. A bar code recording device that forms a mark along the circumference of an optical disc by moving it,
A bar code recording apparatus, wherein the semiconductor laser emits a laser beam having a wavelength (λ) of 400 nm ≦ λ ≦ 410 nm and a film surface laser output (P) of 100 mW ≦ P ≦ 2 W.   An objective lens for condensing laser light emitted from the semiconductor laser and forming a linear laser spot on the optical disk recording surface is provided, and the size of the laser spot has a length (L) in the longitudinal direction of 10 μm ≦ 2. L ≦ 250 μm, the length (d) in the short direction is 0.3 μm ≦ d ≦ 3 μm, and the longitudinal direction of the laser spot is arranged perpendicular to the circumferential direction of the optical disk. The barcode recording apparatus described.   An objective lens having a numerical aperture (NA) of 0.6 ≦ NA ≦ 0.85, and a focus control means for performing automatic focus control of a laser spot on a recording layer for recording a barcode. The bar code recording apparatus according to claim 1 or 2. Laser light emitted from a semiconductor laser is irradiated onto the optical disk recording surface as a laser spot, and the output of the laser light is changed in pulses while synchronizing with the rotation angle of the optical disk. A barcode recording method of a barcode recording apparatus for forming a mark along the circumference of an optical disk by moving the barcode,
The semiconductor laser performs barcode recording while emitting laser light having a wavelength (λ) of 400 nm ≦ λ ≦ 410 nm and a film surface laser output (P) of 100 mW ≦ P ≦ 2 W Recording method.   An objective lens for condensing the laser light emitted from the semiconductor laser and forming a linear laser spot on the optical disk recording surface is provided, and the size of the laser spot has a length (L) in the longitudinal direction of 10 μm ≦ L ≦ 250 μm, the length (d) in the short direction is set to 0.3 μm ≦ d ≦ 3 μm, and barcode recording is performed while the longitudinal direction of the laser spot is arranged perpendicular to the circumferential direction of the optical disk. 5. The barcode recording method according to claim 4, wherein An objective lens having a numerical aperture (NA) of 0.6 ≦ NA ≦ 0.85 and a focus control means for performing automatic focus control of a laser spot on a recording layer for recording a barcode are provided, and the focus control means 7. The bar code recording method according to claim 5, wherein bar code recording is performed while focusing on the optical disc recording surface.

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