JP2009104704A - System and method for recording and reproducing information - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that when optimizing recording conditions of a recording type multi-layer optical disk, it is required to optimize recording conditions of each information layer, so that a test writing time is remarkably increased due to increase in information layers. <P>SOLUTION: In the information recording and reproducing device, trial writing is performed for only a part of information layers, predetermined calculation is performed by using the result of test writing and predetermined temporary recording conditions information, recording conditions of each whole information layers are optimized. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a recording / reproducing apparatus and a recording / reproducing method for an optical information recording medium, and more particularly to a means and a technique for optimizing recording conditions in a multilayer optical information recording medium.

  With the recent development of multimedia, an optical information recording medium (hereinafter referred to as an optical disk) has attracted attention as an information recording medium suitable for distributing a large amount of data and for long-term storage. As this optical disc, (1) a read-only disc in which embossed pits are formed in the information layer by stamping at the time of manufacture and this embossed pit can only be reproduced, and (2) a recording film made of a dye or the like is used in the information layer, A write-once disc that can be recorded only once, (3) a rewritable disc that uses a magneto-optical recording film or phase change recording film for the information layer, and can rewrite and erase data many times. Yes.

  Data recording and reproduction with respect to these optical discs are performed using laser light. The objective lens narrows the laser beam to the diffraction limit and forms a light spot on the information layer of the optical disc. The diameter of the light spot at this time is represented by approximately λ / NA where λ is the wavelength of the laser beam and NA is the numerical aperture of the objective lens. That is, the diameter of the light spot is a value determined by the wavelength of the laser light and the numerical aperture of the objective lens.

  The resolution of recording / reproduction is determined by the diameter of the light spot, and the smaller the diameter, the higher the resolution of recording / reproduction. Therefore, in order to meet the demand for increasing the capacity of the optical disk, reducing the diameter of the light spot is a direct and most effective means. As described above, since the diameter of the light spot is approximately represented by λ / NA, in order to reduce the light spot diameter, it is only necessary to shorten the laser wavelength and increase the numerical aperture of the objective lens. . For example, while the DVD laser wavelength λ is 650 nm or 635 nm and the numerical aperture NA of the objective lens is 0.6, in the next generation optical disc, the wavelength λ is about 400 nm and the numerical aperture NA is more than 0.6. Therefore, the diameter of the light spot is reduced to increase the density. As an example of a next-generation optical disc, Blu-ray Disc achieves high density by setting wavelength λ to 405 nm and numerical aperture NA to 0.85.

  However, when the wavelength of the light source is further shortened, there is a problem that the transmittance of an optical element such as an objective lens or an optical disk substrate is rapidly reduced. Furthermore, when the numerical aperture of the objective lens is further increased, there is a problem that the lens working distance becomes extremely short.

  Therefore, in order to meet the demand for further increase in the capacity of the optical disc, an optical disc in which a plurality of information layers are stacked in addition to the increase in density by reducing the diameter of the light spot has been proposed. For example, at present, optical discs having two information layers have been commercialized, and multilayer optical discs having three or more information layers are being studied in order to further increase the capacity. When data is recorded on the information layer on the back side when viewed from the laser incident side of the multilayer optical disc, a light spot is formed on the information layer on the back side through the information layer on the light incident side. Therefore, an information layer having a high transmittance is arranged on the light incident side so that sufficient laser power reaches the information layer on the back side.

  By the way, the recording marks for recording the embossed pits and data formed in the information layer by stamping in the information layer have to be formed smaller as the capacity of the optical disk increases. For this reason, in the recordable optical disc such as the recordable disc or the rewritable disc, high precision control is required for the laser power at the time of data recording in order to form a minute recording mark. It was. Therefore, when recording marks are accurately formed on a recordable optical disk, it is important to perform test writing before starting data recording to optimize recording conditions such as laser power. In the case of a multilayer optical disc, it is necessary to optimize the recording conditions individually for each information layer. As a technique for optimizing the recording conditions of the multilayer optical disc, for example, test write is performed sequentially using the test write area provided in each information layer to set the optimum laser power for each layer, and the first layer A technique for executing and controlling recording / reproducing operation, second layer recording / reproducing operation,..., N-th layer recording / reproducing operation is disclosed (see Patent Document 1).

JP 2003-346379 A

  As described above, when the recording conditions are optimized for a recordable multi-layer optical disc such as a write once type or a rewritable type, it is necessary to optimize the recording conditions for each information layer. Therefore, when trial writing is performed on a multilayer optical disc having n information layers according to the prior art, the time required for trial writing is n times that of a single-layer optical disc having only one information layer. It was. That is, the trial writing time of a conventional two-layer optical disc having two information layers is about twice that of a single-layer optical disc, whereas the trial writing time of a six-layer optical disc having six information layers is, for example, It took 6 times as much time as a single-layer optical disk.

  In recent years, optical disc recorders have become widespread in general households as video applications. However, the optical disk recorder has a problem of long start-up time as compared with the conventional magnetic tape recorder. Here, the start time is the time from when the medium is inserted into the optical disk recorder until the actual data recording / reproduction starts, but the increase in the start time is performed before the actual data recording / reproduction starts. This is mainly due to the time required for the test writing.

  Increasing the number of information layers of an optical disc is an effective technique for increasing the capacity. However, from the viewpoint of avoiding an increase in start-up time until the start of recording / reproduction, a large increase in the test writing time must be avoided even when the information layer is multi-layered.

  An object of the present invention is to solve such a technical problem. That is, an object of the present invention is to provide an information recording / reproducing apparatus capable of optimizing recording conditions for each information layer in a short time even when a multilayer optical disk is used.

  In order to achieve the object of the present invention, in the information recording / reproducing apparatus according to the present invention, trial writing is performed only on a part of information layers, and the result of the trial writing and predetermined provisional recording condition information are stored. To perform a predetermined calculation to optimize the recording conditions for all information layers.

  According to the information recording / reproducing apparatus of the present invention, the information recording / reproducing apparatus records and reproduces information by irradiating light to an optical information recording medium in which three or more information layers are stacked per light incident surface. Means for storing provisional recording conditions determined for each information layer constituting various optical information recording media as provisional recording condition information, means for reading medium identification information from the optical information recording medium, and Means for selecting the provisional recording condition of each information layer from the provisional recording condition information; means for optimizing the recording condition of all information layers according to the provisional recording condition; and means for optimizing the recording condition, Obtaining an optimum recording result only for the partial information layer by performing trial writing only on the partial information layer of the information layer, and correcting the temporary recording condition based on the optimum recording result By the calculation, the information recording and reproducing apparatus characterized by optimizing the recording condition for each all the information layer.

  In the information recording / reproducing apparatus of the present invention, the provisional recording condition described above includes a recording signal waveform suitable for each information layer and provisional recording power. In the optimization of the recording condition for all the information layers, the provisional recording power is set to the provisional recording power. Based on this, the recording power may be optimized.

  As a result, the recording conditions can be optimized in a simple procedure without optimizing the recording signal waveform, so the time required for optimizing the recording conditions can be further reduced compared to the case where the recording signal waveform is also optimized. Can be

  In the information recording / reproducing apparatus of the present invention, the above-described optimization of the recording conditions is performed on two layers of the optical information recording medium, that is, the information layer farthest from the light incident side and the information layer nearest from the light incident side. Also good.

  The information layer farthest from the light incident side is the information layer that is most susceptible to the variation in transmittance of each information layer during the production of the optical information recording medium, while the information layer closest to the light incident side is each information layer. This is because it is not affected by the transmittance variation of the layer and is easily used as a reference point for recording conditions in the optical information recording medium.

  In the information recording / reproducing apparatus of the present invention, the means for optimizing the recording condition described above is that the optical information recording medium has (n + 1) (m is an integer of 2 or more) Lm information layers (m is 0 to n). From the light incident side in the order of L0 information layer, L1 information layer, L2 information layer,..., Ln information layer, and the information recording / reproducing device corresponds to the optical information recording medium. The Lm information layer has a provisional recording power Pwi (m) (m is an integer of 0 to n), and the information layer farthest from the light incident side and the frontmost from the light incident side in the optical information recording medium. By performing trial writing on the two information layers of the information layer, the optimum recording power Pwo (0) of the L0 information layer farthest from the light incident side in the optical information recording medium and the light in the optical information recording medium Optimal recording power P of the Ln information layer closest to the incident side o (n) is obtained, and the correction coefficient k (0) of the L0 information layer and the correction coefficient k (n) of the Ln information layer are k (0) = Pwo (0) / Pwi (0) and k (n) = Pwo (n) / Pwi (n), and the correction coefficient k (m) of the Lm information layer is k (m) = k (0) + (k (n) −k (0)) × m / The optimal power of the Lm information layer is calculated based on the formula Pwo (m) = k (m) × Pwi (m), and the recording conditions of all the information layers are calculated. May be optimized.

  As a result, the recording power can be optimized with a simple procedure, so that the time required for optimizing the recording conditions can be shortened.

  Further, according to the information recording / reproducing method of the present invention, information is recorded and reproduced by light irradiation on an optical information recording medium in which three or more information layers are laminated per light incident surface, and various types of optical information are recorded. An information recording / reproducing method for optimizing recording conditions of all information layers in accordance with provisional recording conditions defined for each information layer constituting a recording medium, wherein the optimization of the recording conditions is performed on a part of information of the information layer By performing trial writing only on the layers, the optimum recording results are obtained only for the part of the information layers, and the correction calculation based on the optimum recording results is performed for the provisional recording conditions. An information recording / reproducing method characterized by optimizing recording conditions is provided.

  In the information recording / reproducing method of the present invention, the provisional recording condition described above includes a recording signal waveform suitable for each information layer and provisional recording power. In the optimization of the recording condition for all the information layers, the provisional recording power is set to the provisional recording power. Based on this, the recording power may be optimized.

  As a result, the recording conditions can be optimized in a simple procedure without optimizing the recording signal waveform, so the time required for optimizing the recording conditions can be further reduced compared to the case where the recording signal waveform is also optimized. Can be

  In the information recording / reproducing method of the present invention, the above-described optimization of the recording conditions is performed on two layers of the optical information recording medium, that is, the information layer farthest from the light incident side and the information layer nearest from the light incident side. Also good.

  The information layer farthest from the light incident side is the information layer that is most susceptible to the variation in transmittance of each information layer during the production of the optical information recording medium, while the information layer closest to the light incident side is each information layer. This is because it is not affected by the transmittance variation of the layer and is easily used as a reference point for recording conditions in the optical information recording medium.

  In the information recording / reproducing method of the present invention, the means for optimizing the recording condition described above is that the optical information recording medium has (n + 1) (m is an integer of 2 or more) Lm information layers (m is 0 to n). ) In the order of the L0 information layer, the L1 information layer, the L2 information layer,..., The Ln information layer from the farthest from the light incident side, and the deepest information from the light incident side in the optical information recording medium. The optimum recording power Pwo (0) of the L0 information layer farthest from the light incident side in the optical information recording medium is obtained by performing test writing on the two information layers, the information layer closest to the layer and the light incident side. And the optimum recording power Pwo (n) of the Ln information layer closest to the light incident side in the optical information recording medium is acquired, and the correction coefficient k (0) of the L0 information layer and the correction coefficient k (n of the Ln information layer are obtained. ) Is k (0) = Pwo (0) / Pwi (0) and k n) = Pwo (n) / Pwi (n), and the correction coefficient k (m) of the Lm information layer is k (m) = k (0) + (k (n) −k (0)) × The optimum power of the Lm information layer is calculated based on the formula Pwo (m) = k (m) × Pwi (m) Recording conditions may be optimized.

  As a result, the recording power can be optimized with a simple procedure, so that the time required for optimizing the recording conditions can be shortened.

  According to the present invention, it is possible to obtain an information recording / reproducing apparatus and an information recording / reproducing method capable of optimizing the recording conditions of the multilayer optical information recording medium in a short time.

  Hereinafter, the present embodiment will be described in detail based on examples. Note that the present embodiment is not limited to the following examples.

  In this example, a write-once type multi-layer optical disk having six information layers and an optical disk recorder corresponding to recording / reproduction of a six-layer multi-layer optical disk were produced, and video data was recorded on the multi-layer optical disk.

The multilayer optical disc has an information layer and a layer made of a transparent resin alternately laminated on a polycarbonate resin disc substrate having a thickness of 1.1 mm, an outer diameter of 120 mm, and an inner diameter of 15 mm, and the total thickness is 1.2 mm. It became the form which becomes. The disk substrate is formed by injection molding and provided with a spiral tracking guide groove having a groove pitch of 0.32 μm. On the surface side where the tracking guide groove is formed on the disk substrate, an Al alloy reflective layer, a ZnS—SiO ₂ dielectric layer, a Te—Pd—O recording layer, and a ZnS—SiO ₂ dielectric layer are first formed as the L0 information layer. It formed in order by sputtering method. Subsequently, on the L0 information layer, the intermediate layer 16 μm, the L1 information layer, the intermediate layer 14 μm, the L2 information layer, the intermediate layer 17 μm, the L3 information layer, the intermediate layer 15 μm, the L4 information layer, the intermediate layer 13 μm, and the L5 information layer. Formed in order.

  The intermediate layer was formed by the following method. First, a transparent ultraviolet curable resin was applied onto the information layer by spin coating, and an amorphous polyolefin resin stamper was bonded thereon. Then, ultraviolet rays were irradiated from the stamper side to cure the ultraviolet curable resin, and the stamper was peeled off to form intermediate layers each having a spiral tracking guide groove with a groove pitch of 0.32 μm.

The L1 to L5 information layers were formed by sputtering after optical adjustment suitable for each information layer. The L1 to L5 information layers are composed of a plurality of layers, and are formed in the order of a ZnS—SiO ₂ dielectric layer, a Te—Pd—O recording layer, and a ZnS—SiO ₂ dielectric layer.

  A cover layer was formed on the L5 information layer. The cover layer was formed by applying a transparent ultraviolet curable resin on the L5 information layer by spin coating, and irradiating the ultraviolet ray to cure the ultraviolet curable resin. The thickness of the cover layer is 25 μm.

  On the other hand, the optical disk recorder incorporates a video broadcast receiver, a fixed disk recording / reproducing apparatus, and an optical disk recording / reproducing apparatus. The fixed disk recording / reproducing apparatus includes a magnetic disk therein, and can record video data received by the video broadcast receiver on the magnetic disk. The video recorded on the magnetic disk of the fixed disk recording / reproducing apparatus can move the data onto the interchangeable optical disk by the optical disk recording / reproducing apparatus.

  An optical disc recording / reproducing apparatus records information by rotating an optical disc by a rotation driving mechanism and irradiating the optical disc with an optical head. Further, at the time of reproducing information, information is reproduced by irradiating the optical disk with laser light from the optical head and detecting the laser light reflected from the optical disk. The disk was rotated so that the linear velocity was constant. In this example, the linear velocity was 4.92 m / s.

  The wavelength λ of the laser light source constituting the optical head is 405 nm, and the numerical aperture NA of the objective lens is 0.85. The optical head is provided with spherical aberration correcting means. In this correction means, when the light is condensed on the L0 to L5 information layers of the multilayer optical disc, a correction amount is set in advance so that spherical aberration correction suitable for each information layer can be performed. In the present embodiment, the correction means is realized by moving the collimator lens in the optical axis direction.

  The laser beam needs to be focused on the target track of the target information layer of the multilayer optical disk by the objective lens of the optical head. Therefore, the conventional focus servo and track servo were used.

  Thus, the basic preparation for recording on each information layer of the multilayer optical disc is completed. However, before that, it is necessary to optimize the recording conditions of each information layer as described above.

  When optimizing the recording conditions, first, provisional recording conditions specific to the optical disc were determined. For this purpose, the medium identification information recorded in advance on the optical disc is read, and the information corresponding to the medium identification information in the provisional recording condition information registered in advance in the control software of the optical disc recording / reproducing apparatus is referred to. The provisional recording condition information includes information such as a recording signal waveform and recording power corresponding to the medium identification information. When optimizing the recording conditions, information such as a recording signal waveform and recording power corresponding to the medium identification information was used as a provisional recording condition.

  Trial writing for optimizing the recording conditions was performed based on the provisional recording conditions. Specifically, it is as shown below. In the trial writing, the trial writing data was recorded while changing the conditions little by little with respect to the provisional recording conditions, and then the data recorded under each condition was reproduced. In the trial writing, asymmetry was used as the evaluation index, and the recording condition under which the optimum value of the evaluation index was obtained for each information layer was determined as the optimal recording result of the information layer.

Asymmetry is defined by [(I _8H + I _8L ) / 2− (I _2H + I _2L ) / 2] / (I _8H −I _8L ), which represents the asymmetry of the waveform of the long mark and the short mark of the reproduction signal. Here, I _8H is the maximum value of the 8T signal, I _8L is the minimum value of the 8T signal, I _2H is the maximum value of the 2T signal, and I _2L is the minimum value of the 2T signal. Asymmetry has a correlation with the value of the error rate. In the case of this example, the minimum error rate was obtained in the range of asymmetry 0.02 to 0.04 for any information layer in the preliminary trial examination. Therefore, the optimum recording result is determined for each information layer with the optimum value of asymmetry being 0.03.

  Information on specific procedures for optimizing the recording conditions for each information layer based on these optimum recording results is associated with the medium identification information and recorded as recording condition optimization procedure information in the control software of the optical disc recording / reproducing apparatus. Registered in advance.

  The recording condition optimization procedure is the most characteristic feature of the present invention over the prior art. Therefore, a specific procedure for optimizing the recording condition for each information layer will be described below with a specific example. Note that the present embodiment is not limited to the following examples.

  The present invention performs trial writing on only a part of information layers in a multi-layer optical disc, performs a predetermined calculation using the result of the trial writing and provisionally defined recording conditions, The recording conditions are optimized. The procedure for optimizing the recording conditions according to the present invention is shown in FIG. Hereinafter, a recording condition optimization method according to the present invention will be described by taking a six-layer multilayer optical disk as an example.

  First, a write-once six-layer optical disk was manufactured by the method described above.

  The trial writing area of the multilayer optical disk used in this example was provided with a radius of 23.28 mm to 23.62 mm of the L0 information layer and a radius of 23.62 mm to 23.96 mm of the L5 information layer. No trial writing area is provided. This is because the present invention performs test writing only on a part of information layers (in this embodiment, L0 and L5 information layers), and uses a result of the test writing and a provisionally defined recording condition. This is because the recording conditions for all the information layers are optimized. A radius of 23.28 mm to 23.62 mm excluding the trial writing area in each information layer was set as an unrecorded area.

  In the provisional recording condition information, a recording signal waveform suitable for each information layer and provisional recording power information for each information layer are input from data measured in the preliminary trial examination. The provisional recording condition information and the following recording condition optimization procedure information are registered in the control software of the optical disc recording / reproducing apparatus in association with the medium identification information of the optical disc.

  The recording condition optimization procedure information includes the following optimization methods as information.

  First, trial writing of the L0 information layer and trial writing of the L5 information layer are performed. As a result, the optimum recording power Pwo (0) was obtained in the L0 information layer, and the optimum recording power Pwo (5) was obtained in the L5 information layer. Then, based on these values, correction calculation was performed on the recording power value of each information layer included in the provisional recording condition, and the correction calculation result was determined as the optimum recording power of each information layer. In the present embodiment, the provisional recording power of each information layer is multiplied by a correction coefficient to optimize the recording conditions for all information layers.

  Specifically, the correction coefficient k (m) of the Lm information layer (m is an integer of 0 to 5) is k (m) = k (0) + (k (5) −k (0)) × m / It was calculated based on the correction formula expressed as 5. Here, if the provisional recording power corresponding to the Lm information layer (m is an integer of 0 to 5) is Pwi (m), k (0) = Pwo (0) / Pwi (0), k (5) = Pwo (5) / Pwi (5). The other correction coefficients were calculated by putting the values of k (0) and k (5) into the correction equation. The optimum power of the Lm information layer (m is an integer of 0 to 5) was calculated by Pwo (m) = k (m) × Pwi (m).

(Comparative Example 1)
In the following, a method for optimizing the recording conditions of a six-layer optical disk according to the prior art will be shown as a comparative example. In this comparative example, trial writing is performed on each information layer to optimize the recording conditions. The optimization procedure of Comparative Example 1 corresponds to a routine in the case where the optimization method of the present invention is not followed among the procedures shown in FIG.

  First, a write-once six-layer optical disk for Comparative Example 1 was manufactured, and provisional recording condition information and recording condition optimization procedure information corresponding to the medium identification information of the optical disk were registered in the control software of the optical disk recording / reproducing apparatus.

  The trial writing area of the optical disc includes the radius of the L0 information layer 23.28 mm to 23.62 mm, the radius of the L1 information layer 23.62 mm to 23.96 mm, the radius of the L2 information layer 23.96 mm to 24.30 mm, and the L3 information layer. A radius of 24.30 mm to 24.64 mm, a radius of the L4 information layer of 24.64 mm to 24.98 mm, a radius of the L5 information layer of 24.98 mm to 25.32 mm, and a radius excluding the trial writing area in each information layer 23. 28 mm to 25.32 mm was set as an unrecorded area. As described above, a trial writing area is provided in each information layer. This is because test writing is performed on each information layer to optimize the recording conditions. Therefore, the medium identification information of the optical disk of Comparative Example 1 is different from the medium identification information of the optical disk of Example 1.

  In the provisional recording condition information, a recording signal waveform suitable for each information layer and provisional recording power information for each information layer are input from data measured in the preliminary trial examination. The recording condition optimization procedure is a procedure in which trial writing of the L0 to L5 information layers is performed in order, and the obtained result is determined as the optimum recording power of each information layer.

(Comparative Example 2)
In the following, a method for optimizing the recording condition of a two-layer optical disc according to the prior art will be shown as a comparative example. In this comparative example, trial writing is performed on each information layer to optimize the recording conditions. The optimization procedure of the comparative example 2 corresponds to a routine in the case where the optimization method of the present invention is not followed in the procedure shown in FIG.

  First, a write-once two-layer optical disk for Comparative Example 2 was manufactured, and provisional recording condition information and recording condition optimization procedure information corresponding to the medium identification information of the optical disk were registered in the control software of the optical disk recording / reproducing apparatus.

  In a two-layer optical disk, an L0 information layer, an intermediate layer 25 μm, an L1 information layer, and a cover layer 75 μm are sequentially laminated on a disk substrate, and each information layer is optically adjusted to be suitable for a two-layer optical disk. The six-layer optical disk of Comparative Example 1 was manufactured in the same manner except that The medium identification information of the optical disk of Comparative Example 2 is different from the medium identification information of the optical disks of Example 1 and Comparative Example 1. The trial writing area of the optical disc is provided in the radius of 23.28 mm to 23.62 mm of the L0 information layer and the radius of 23.62 mm to 23.96 mm of the L1 information layer. 23.96 mm was set as an unrecorded area.

  In the provisional recording condition information, a recording signal waveform suitable for each information layer and provisional recording power information for each information layer are input from data measured in the preliminary trial examination. The recording condition optimization procedure is a procedure in which trial writing of the L0 information layer and trial writing of the L1 information layer are performed in order, and the obtained result is determined as the optimum recording power of each information layer.

(Optimization of recording conditions)
The produced optical disk was loaded into an optical disk recording / reproducing apparatus of an optical disk recorder, and video data was recorded. When the optical disc was loaded, first, the medium identification information on the optical disc was reproduced and the recognition operation was executed. Next, when a recording start command is sent from the operation software of the optical disk recorder, trial writing and optimum recording power calculation are performed using the provisional recording condition information and the recording condition optimization procedure information registered on the control software. Then, video data recording was started. When the operation of the control software was monitored, the optimum recording power determined for the temporary recording power in Example 1 was the result shown in Table 1. For Comparative Example 1, the results shown in Table 2 were obtained. For Comparative Example 2, the results shown in Table 3 were obtained. In order to verify the optimum recording power, an error rate measuring circuit was connected to the optical disk recording / reproducing apparatus, and the reproduction signal was evaluated for the optical disk after recording was completed. As a result, excellent recording characteristics with an error rate of 2.0 × 10 ⁻⁵ or less were confirmed in all the information layers of Example 1, all of the information layers of Comparative Example 1, and all of the information layers of Comparative Example 2. .

(Measurement of recording condition optimization time)
In the optical disk recorder of the present embodiment described above, the optimization time of the recording conditions when actually recording on the optical disk was measured. The optimization time of the recording condition was measured as a time required for a series of processes (from when a recording start command is sent until recording of recording data is started) related to test writing performed before data recording.

  The data used for recording on the optical disk was previously received by the video broadcast receiver and recorded on the magnetic disk by the fixed disk recording / reproducing apparatus. When measuring the optimization time, the video data was moved from the magnetic disk to the optical disk. Prior to measurement, the optical disk was loaded in the optical disk recording / reproducing apparatus in advance, and the recognition operation of the medium identification information was completed. The recording condition optimization time is measured from the time when the recording start command is sent from the operation software of the optical disk recorder, and the video after the trial writing is completed while observing the recording signal waveform input to the laser light source with an oscilloscope. The end point was the time when the first signal of data was input to the laser light source. The time interval between these start points and end points was measured with a stopwatch. The measurement was performed on 10 optical disks under the same conditions, and the average optimization time was obtained.

  In addition, in order to compare the time required for optimizing the recording conditions between the present embodiment and the prior art, not only the embodiment but also the average optimization time in the prior art shown in the comparative examples 1 and 2 was obtained. .

When recording video data on an optical disc, the optimization time of the recording conditions was measured in parallel with the optimization of the recording conditions. As a result, the average optimization time shown in Table 4 was measured for each optical disc. The six-layer optical disk of Comparative Example 1 required about three times the optimization time of the two-layer optical disk of Comparative Example 2, whereas the six-layer optical disk of Example 1 was a six-layer optical disk, but the comparative example Recording could be started with an optimization time similar to that of the two-layer optical disc.

From the above, according to the recording condition optimization procedure based on the present invention, even when the number of information layers of the multilayer optical disk is increased, the time required for optimization of the recording condition can be greatly shortened as compared with the prior art. .

It is a flowchart explaining the optimization of the recording conditions of the multilayer optical disk according to this invention.

Claims (8)

An information recording / reproducing apparatus for recording and reproducing information by irradiating light to an optical information recording medium in which three or more information layers are laminated per light incident surface,
Means for storing provisional recording conditions determined for each information layer constituting various optical information recording media as provisional recording condition information;
Means for reading the medium identification information from the optical information recording medium;
Means for selecting a provisional recording condition of each information layer of the medium identification information from the provisional recording condition information;
Means for optimizing the recording conditions of all information layers according to the provisional recording conditions,
The means for optimizing the recording condition obtains the optimum recording result only for the partial information layer by performing trial writing only for the partial information layer of the information layer, and An information recording / reproducing apparatus characterized by optimizing recording conditions for all information layers by performing correction calculation based on an optimum recording result. The provisional recording condition consists of a recording signal waveform and provisional recording power suitable for each information layer,
2. The information recording / reproducing apparatus according to claim 1, wherein in the optimization of the recording conditions for all the information layers, the recording power is optimized based on the provisional recording power.   3. The information recording according to claim 2, wherein test writing is performed on two information layers of the optical information recording medium: an information layer farthest from the light incident side and an information layer nearest to the light incident side. Playback device. The optical information recording medium has (n + 1) (n is an integer of 2 or more) Lm information layers (m is an integer of 0 to n) from the light incident side to the L0 information layer, L1 information layer, L2 Information layer, ..., Ln information layer in this order,
The information recording / reproducing apparatus has provisional recording power Pwi (m) (m is an integer of 0 to n) for each Lm information layer according to the optical information recording medium,
By performing test writing on the two information layers, the information layer farthest from the light incident side in the optical information recording medium and the information layer closest to the light incident side, from the light incident side in the optical information recording medium. The optimum recording power Pwo (0) of the innermost L0 information layer and the optimum recording power Pwo (n) of the Ln information layer nearest to the light incident side in the optical information recording medium are acquired,
The correction coefficient k (0) of the L0 information layer and the correction coefficient k (n) of the Ln information layer are k (0) = Pwo (0) / Pwi (0) and k (n) = Pwo (n) / Pwi ( n),
The correction coefficient k (m) of the Lm information layer is calculated based on a correction formula represented by k (m) = k (0) + (k (n) −k (0)) × m / n,
4. The optimum power of the Lm information layer is calculated based on an expression of Pwo (m) = k (m) × Pwi (m), and the recording conditions of all the information layers are optimized. The information recording / reproducing apparatus described. Information is recorded and reproduced by light irradiation on an optical information recording medium in which three or more information layers are laminated per light incident surface, and provisional information determined for each information layer constituting various optical information recording media. An information recording / reproducing method for optimizing the recording conditions of all information layers according to the recording conditions,
In the optimization of the recording condition, the optimum recording result is acquired only for the partial information layer by performing trial writing only for the partial information layer of the information layer, and the optimal recording is performed for the temporary recording condition. An information recording / reproducing method characterized by optimizing recording conditions for all information layers by performing correction calculation based on a result. The provisional recording condition consists of a recording signal waveform and provisional recording power suitable for each information layer,
6. The information recording / reproducing method according to claim 5, wherein in the optimization of the recording conditions for all the information layers, the recording power is optimized based on the provisional recording power.   7. The information recording according to claim 6, wherein test writing is performed on two information layers of the optical information recording medium: an information layer farthest from the light incident side and an information layer nearest to the light incident side. Playback method. The optical information recording medium has (n + 1) (n is an integer of 2 or more) Lm information layers (m is an integer of 0 to n) from the light incident side to the L0 information layer, L1 information layer, L2 Information layer, ..., Ln information layer in this order,
The information recording / reproducing apparatus has provisional recording power Pwi (m) (m is an integer of 0 to n) for each Lm information layer according to the optical information recording medium,
By performing test writing on the two information layers, the information layer farthest from the light incident side in the optical information recording medium and the information layer closest to the light incident side, from the light incident side in the optical information recording medium. The optimum recording power Pwo (0) of the innermost L0 information layer and the optimum recording power Pwo (n) of the Ln information layer nearest to the light incident side in the optical information recording medium are acquired,
The correction coefficient k (0) of the L0 information layer and the correction coefficient k (n) of the Ln information layer are k (0) = Pwo (0) / Pwi (0) and k (n) = Pwo (n) / Pwi ( n),
The correction coefficient k (m) of the Lm information layer is calculated based on a correction formula represented by k (m) = k (0) + (k (n) −k (0)) × m / n,
8. The optimum power of the Lm information layer is calculated based on a formula of Pwo (m) = k (m) × Pwi (m), and the recording conditions of all the information layers are optimized. The information recording / reproducing method described.

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