JP2005259345A - Optical disk recording/reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To always perform the recording with the optimum recording condition, in a recording medium such as a phase change type optical disk. <P>SOLUTION: In performing the recording on the recording medium such as an overwritable optical disk, a test signal is supplied to an optical pickup during a period of time for writing a temporary storage memory so that the recording is performed in the vicinity of the recording area. The intensity of a laser beam of the optical pickup is optimized, on the basis of the evaluation result of the test recording. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

    The present invention relates to an optical disc recording / reproducing apparatus for recording an information signal on an overwritable optical disc or the like.

  In a conventional optical disk device, for example, an MD (Mini Disc) player, data is temporarily stored in a 4 MB (bit) shock proof memory corresponding to a reproduction time of about 10 seconds, and a signal is output from the shock proof memory. However, when the pickup kicks the track while it is being reproduced, the next sector to be reproduced is awaiting rotation. Also, during recording, the recorded signal is compressed and temporarily stored in a shock proof memory, and the signal is intermittently read from this memory and recorded on the disk. During the remaining time, the pickup kicks the track. Thus, the rotation waiting for the sector to be recorded next is performed.

  In addition, a DVD (Digital Video Disc) player is similarly equipped with a 16 MB memory, and since it has a variable transfer rate and a high transfer speed, the storage time of this memory is about 2 seconds. Kicks the track and waits for rotation. Currently, it is difficult to obtain a 4 MB DRAM, and it has become common to use a DRAM of 16 Mbit or more. For this reason, temporary storage for 2 seconds or more is becoming possible.

  By the way, a technique for reproducing and recording high-density information using laser light is known, and is mainly put into practical use as an optical disc apparatus. Optical discs can be broadly classified into read-only, write-once, and rewritable types. The reproduction-only type is commercialized as a CD (Compact Disc) recording music information, a VCD (Video CD) or DVD recording image information, and the write-once type is CD-R or DVD-R. Further, as a rewritable type, CD-RW, DVD-RAM, DVD-RW, and the like are being commercialized for video and audio recording or data recording for personal computers.

  Among these, the rewritable type uses a recording thin film in which two or more states are reversibly changed by changing the irradiation condition such as laser light, and the main types are a magneto-optical type and a phase change type. is there. Phase change discs record the signal by reversibly changing the recording film between amorphous and crystalline by changing the laser light irradiation conditions, and optically measuring the difference between the amorphous and crystalline laser light reflectance. It is detected and played back. The signal can be reproduced as a change in the reflectance of the laser beam in the same way as the read-only type and the write-once type, and the write-once (overwrite) is performed by modulating the laser power between the erase level and the recording level. ) Can be performed with one beam, and there is an advantage that the apparatus configuration can be simplified.

As a technique for increasing the density of signal recording in such a rewritable optical disc, a pulse width modulation method (PWM) in which the edge positions before and after the recording mark correspond to “1” of the digital signal has been studied.
Japanese Patent Laid-Open No. 3-185628 Japanese Patent Laid-Open No. 6-12673

  By the way, in the PWM system, since the width of the recording mark has information, it is necessary to record the recording mark on the recording film so as not to be distorted, that is, symmetrically in the longitudinal direction. However, in the laser irradiation portion of the disk when recording a signal, the end point becomes higher than the irradiation start point due to the heat storage effect. For this reason, the recording mark has a disadvantage that the end of the recording mark is wider than the leading end, and the recording mark shape is narrow at the leading end and thick at the trailing end and is distorted into teardrops.

  The reason why such a recording mark is distorted into teardrops will be further described below with reference to the drawings. FIG. 15A shows an input signal waveform to be recorded. When this is directly used as laser light output as shown in FIG. 6B and a signal is recorded by modulating between the erasing power level Pe and the recording power level Pw, the temperature reached by the recording film is as shown in FIG. become that way. That is, due to the heat storage effect, the temperature at the end portion is higher than the tip portion of the recording mark, and as a result, the shape of the recording mark becomes wider at the end than the tip as shown in FIG. Distorted into a shape Since the heat storage effect increases as the relative speed (linear velocity) between the optical disk and the laser spot decreases, the tear-like distortion increases as the linear velocity decreases. Since this distortion causes distortion of the reproduction waveform, there is a possibility that the recorded signal cannot be read correctly.

  As a method for reducing such distortion of the recording mark, Japanese Patent Laid-Open No. 3-185628 discloses an overwriting method in which one recording mark is formed by irradiation with a plurality of short pulse trains. Japanese Patent Application Laid-Open No. 6-12673 discloses a method for correcting the pulse waveform. Referring to FIG. 16, after the input signal as shown in FIG. 16A is converted into a short pulse train, the laser output is changed between the erasing power level Pe and the recording power level Pw as shown in FIG. The signal is overwritten by modulating with. Here, the short pulse train consists of a wide first pulse and a subsequent pulse train narrower than this. The width of the leading pulse is always constant regardless of the length of the recording mark. Further, the width and interval of each pulse in the subsequent pulse train are equal and the number of pulses in the subsequent pulse when the nth recording mark is formed is n−1.

  For example, an 8-14 modulation signal (EFM signal) employed in a CD is composed of nine types of pulses from 3T (T is a clock cycle) to 11T. When recording this EFM signal, the shortest 3T pulse is converted to the first pulse only, the next 4T pulse is converted to the first pulse and one subsequent pulse, and the 5T pulse is converted to the first pulse and two subsequent pulses. To do. The longest 11T pulse is converted into a leading pulse and eight subsequent pulses. By converting with such regularity, the signal conversion circuit can have a simple configuration. In this case, as shown in FIG. 5C, the temperature reached by the recording film is rapidly raised by the wide leading pulse at the tip, but thereafter, the pulse train is irradiated, so that the temperature rise at the end is suppressed. . As a result, the shape of the recording mark is improved in symmetry between the tip and end as shown in FIG.

  However, the method of shortening the pulse is very effective when the linear velocity is low and the recording frequency is low, but in the case of high-density recording such as DVD-RAM and DVD-RW, the linear velocity is high. When the frequency of the recording signal is high, it is not always effective. When the recording signal waveform is shortened, the energy given to the recording film is reduced, so that a large recording power is required. This is not a problem at a low linear velocity, but if the linear velocity is increased and a larger recording power is required, a high-power laser light source is required, and the cost of the recording apparatus is increased. In addition, in order to shorten the input signal, a clock signal having a period of 1 / integer of the pulse period of the input signal (T in the case of the EFM signal) is necessary, and the frequency of the recording signal is high. In this case, the frequency of the clock signal becomes too high, making circuit design difficult. As the laser output is also modulated at a high frequency, the waveform distortion becomes larger.

  Considering a general method of using an optical disk, when the optical disk is rotated at a constant rotation speed (hereinafter referred to as CAV), the linear velocity is faster on the outer circumference than on the inner circumference of the disk. In order to increase the recording density by making the recording mark length the same at the inner periphery and the outer periphery, a method of increasing the recording frequency at the outer periphery has also been proposed. Even when the optical disk is rotated at a constant linear velocity in all areas (hereinafter referred to as CLV), when signals are recorded on different types of disks with the same recording device, the linear velocity and recording frequency are changed depending on the type of the disk. There is a need.

In addition, in the case of a disk having a higher recording density, there is a possibility that the reproduction quality is deteriorated due to the optimum recording condition being different depending on the environmental condition such as the variation of each disk, the number of times of recording of the disk, or the ambient temperature. In order to determine the optimum recording conditions for each disc, the recording operation is temporarily stopped, the test recording area is moved, the test recording is performed, the signal is reproduced, the signal quality is measured, and the optimum value is determined. I have to find it. However, it takes too much time to perform such measurement at the time of recording, and there is a problem that a signal to be originally recorded cannot be recorded from the beginning. In addition, when recording a disk having a higher recording density with high accuracy, the laser output to be recorded fluctuates due to temperature characteristics, changes with time, etc., and there is a possibility that the recording quality will deteriorate. Also in this case, it is necessary to stop the recording operation once, measure the laser power, and find the optimum value. However, performing such measurement at the time of recording has a problem that it takes too much time, and all continuous signals such as moving images cannot be recorded.
Also, when test recording and this evaluation are performed to obtain an optimum power, especially in the case of high-density R organic dyes and RW phase change media that are recorded using a DVD or a blue laser, the structure of the optical disk material of each company or Since the manufacturing method is different, there is a disc in which an optimum value cannot be remarkably obtained by the method of detecting asymmetry conventionally used in CD-R or the like. Further, in the RW phase change medium, when the same signal is recorded a plurality of times at the same location (position) of the optical disk at the same timing, there is generally a problem that the jitter at the time of reproduction suddenly deteriorates every time recording is performed. .

The present invention focuses on the above points and comprises the following means. That is, when the information signal is recorded on the optical disc by the laser beam irradiated from the optical pickup, the information signal is written to temporarily store the information signal in the temporary storage means, and then read out from the temporary storage means. In an optical disk recording / reproducing apparatus for recording
In the period of writing the information signal to the temporary storage means, a predetermined signal is recorded in the vicinity of the recording position of the optical disk to be recorded next, and the intensity of the laser beam is based on the result of evaluation. A correction means for optimizing the above is provided.

  According to the present invention, the recording power and signal waveform correction of the optical pickup in the vicinity of the recording area of the optical disc can be corrected according to various conditions at the time of recording without interrupting the recording operation. Since recording is performed in the recording area, which is the data area to be recorded next, test recording and evaluation can be performed in a short time without damaging operability, and no new recording evaluation area is required. The area can be used effectively and the density can be increased.

  First, the technology as the background of the present invention will be described. Prior to the present invention, the present applicant, in Japanese Patent Application No. 10-204572, uses the time when the optical pickup is not recording, that is, when the recording signal is written to the shock proof memory. The optical pickup is moved to a test recording area of the optical disc (for example, the inner circumference of the optical disc), and a test signal is recorded to obtain an optimum recording waveform. However, in this method, if there is a variation in the recording sensitivity of the disc between the test recording area and the actual recording area due to variations in the surface of the optical disc, the optimum recording waveform may not be obtained. When the test recording area is away from the area to be recorded next, it takes time to seek, and the test recording time is limited accordingly, the power is increased, and vibration is generated during that time. In some cases, the device may become unstable, and further effective proposals have been requested in this regard.

  Examples of the present invention will be described in detail below. In the embodiment of the present invention, the recording laser waveform is corrected to the optimum shape in accordance with the change in the type of optical disk and the linear velocity. For example, when the input signal (for example, 8-16 modulation signal) is shown in FIG. 1A, the laser modulation waveform in FIG. As shown in B), the recording waveform WA is made into a short pulse train. When the linear velocity is faster than the set value, the laser modulation waveform is converted into a recording waveform WB with a slightly shorter input pulse width as shown in FIG.

  Next, a specific example will be described. First, recording and reproduction are performed on a single phase change optical disk while changing the linear velocity and the recording waveform in various ways to obtain the relationship between the linear velocity and the reproduction waveform distortion. The structure of the optical disk used in the experiment is shown in FIG. The substrate 1 is a 120 mm diameter disk made of polycarbonate and provided with a signal recording track. The recording film 2 is made of three elements of GeSbTe and has a thickness of 20 nm. The upper and lower dielectric films 3 and 4 of the recording film 2 are ZnS, and the substrate side is 150 nm and the opposite side is 15 nm. As the reflective film 5, 50 nm of Au is provided.

  The recording film 2 of such an optical disc is crystallized on the entire surface in advance (signal erased state), and then a signal is recorded as an amorphous recording mark by laser irradiation. As the linear velocity of the optical disk, four velocities of 1.5 m / s, 3 m / s, 6 m / s, and 9 m / s were selected by changing the rotation speed. As an input signal, an 8-16 modulation signal was adopted. Then, the semiconductor laser is driven by a method of (1) correcting and modulating a short pulse train as in the recording waveform WA, and (2) a method of correcting and modulating the pulse train slightly short as in the recording waveform WB, respectively. Recorded.

  The specific shape of the recording waveform is as shown in FIG. First, FIG. 2A shows an example of an input waveform of an 8-16 modulation signal, and T is a clock cycle. FIG. 4B shows a recording waveform WA. In this case, the width Ta until pulse generation was 1T, the width of the leading pulse in the short pulse train was Tb 1.5T, and the width Td and interval Tc of the subsequent pulses were both 0.5T. That is, the clock period of the recording waveform WA is 0.5T, and a clock having a frequency twice that of the 8-16 modulation signal is required. FIG. 4C shows a recording waveform WB. In this case, the width of all the recording pulses is made shorter by T than the 8-16 modulation signal.

  Note that the clock frequency of the 8-16 modulation signal was changed so that the recording mark length would be the same even if the linear velocity was changed. Specifically, when the linear velocity is 1.5 m / s, the clock frequency is 4.3 MHz, when the linear velocity is 3 m / s, the clock frequency is 8.6 MHz, and when the linear velocity is 6 m / s, the clock frequency is 17. When the frequency is 2 MHz and the linear velocity is 9 m / s, the clock frequency is 25.8 MHz.

  Next, the signal recorded as described above is reproduced, and the magnitude of distortion of the reproduced waveform is obtained. The quantitative evaluation of the reproduction waveform distortion is performed by binarizing the reproduction waveform in advance and then inputting it to a time interval analyzer to obtain the jitter amount as a phase margin. The larger the phase margin, the smaller the shift amount of the edge position before and after the recording mark, and the smaller the distortion of the recording mark. FIG. 4 shows the relationship between the phase margin and the linear velocity variation in several types of disks. The recording waveform was B when the linear velocity was 9 m / s. FIG. 5 shows the relationship between the phase margin and the variation in linear velocity with respect to the temperature change of the optical disk. FIG. 6 shows the relationship between the recording power and the linear velocity on the disk surface of the optical disk at that time. The erasing power was fixed at each linear velocity regardless of the difference in all the recording waveforms.

  As is clear from FIG. 4, the recording waveform WA is preferable in that the phase margin is larger as the linear velocity is faster although the inclination is small, but there is disc-to-disk variation. Further, referring to FIG. 5, there is a variation in margin due to temperature. This indicates that in the case of overwriting, the temperature of the recording film is governed by the temperature of the recording film, so that the disk temperature could not be optimal due to variations in linear velocity, ambient temperature, disk manufacturing variations, etc. Yes. As for the recording power, as shown in FIG. 6, in the recording waveform WA, the energy given to the recording film is given by a short pulse train, so that a large recording power is required. For this reason, a semiconductor laser having a large output is required as a light source, particularly at a high linear velocity.

  Further, like the recording waveform WC in FIG. 7A, the laser power may be made lower than the erasing level before and after the recording pulse train of the recording waveform WA in FIG. In this way, when recording with a narrow mark interval, it is possible to reduce the phenomenon of thermal interference in which the heat of the region irradiated with the recording power diffuses backward and the next recording mark is drawn large. Therefore, it is effective for increasing the phase margin. If the period during which the laser power is set lower than the erasing level is too long, the recording film will not reach the crystallization temperature or higher, and unerased will occur. However, if the period τ to be lower than the erasure level is within the range of τ ≦ λ / V (λ: laser wavelength, V: relative speed of the laser spot and the optical disk), the erasing power Pe and recording before and after that period are recorded. Irradiation is repeated with the power Pw, and the temperature is also increased by conduction heat from the areas irradiated with the erasing power Pe and the recording power Pw before and after that period. Therefore, the recording film reaches the crystallization temperature, and the unerased residue can be reduced.

  In the recording waveform WC, the laser power is set lower than the erasure level both before and after the recording pulse train. However, only one of the front and rear is effective. Further, if the level lower than the erase level is set as the reproduction power level or the laser off level, the apparatus configuration can be simplified. Similarly, in the recording waveform WB of FIG. 3, a level lower than the erasing level may be provided before and / or after the recording power. The recording waveform WA in FIG. 3 may be modulated between the recording power level and the reproduction power level or the laser off level in the period corresponding to the recording pulse train, as in the recording waveform WD in FIG. 7B. In this method, since the recording film is rapidly cooled after being melted at all locations in the recording mark, a stable recording mark can be formed, and it is effective for increasing the phase margin.

  Next, the optical disk apparatus according to the present embodiment will be described with reference to FIGS. For example, as shown in FIG. 11, in a DVD-RW disc, since the sector in the disc is a spiral CLV, the linear velocity is constant, and an ECC block that is one minimum unit of correction is reproduced and recorded. It is also the smallest unit, 2 ECC blocks in the inner area EA, 16 sectors in one ECC block, and 4 ECC blocks in the outer area EB. The rotation period is also about 40 msec on the inner periphery of the area EA and about 80 msec on the outer periphery of the area EB.

  Next, main parts will be described with reference to FIGS. 9 and 10. The system controller 12 determines the start of reproduction and recording input by the key input unit 10 and instructs the signal processing unit 14 and the servo processor 16. The servo processor 16 drives the spindle motor 20 via the driver 18 and the disk 22 rotates. The signal read from the optical pickup 24 is supplied to the preamplifier 26 whose detailed configuration is shown in FIG. 10, where a reproduction signal and a servo signal are generated. The servo error signal is generated by a servo error signal generation circuit 49. The servo processor 16 processes the servo signal to generate a focusing or tracking signal for the track of the optical disk 22. Based on these signals, the driver 18 drives the actuator of the optical pickup 24 to perform one-round servo control of the optical pickup 24.

  The reproduction signal is supplied to the preamplifier 26 shown in FIG. 10 and amplified by the RF amplifier 50. The frequency characteristic of the reproduction signal after amplification is optimized by the equalizer 52 and subjected to PLL control by the PLL circuit 54. Further, the jitter value generated by the jitter generation circuit 56 based on the comparison between the PLL bit clock and the time axis of the data is measured by the A / D conversion by the system controller 12, and the waveform correction circuit at the time of recording is measured according to this value. change. The jitter detection timing of the jitter generation circuit 56 is controlled by a timing generation circuit 74 described later. In the signal processing unit 14, the reproduction signal is converted into a digital signal and, for example, synchronization detection is performed. As a result, the 8-16 modulation signal on the disk is decoded into NRZ data, and error correction processing is performed to obtain a sector address signal and a data signal. Since this signal is a signal compressed at a variable transfer rate, it is stored in the temporary storage memory 28 (4 MB DRAM), and correction (time axis absorption) is performed to adjust the time axis at the variable transfer rate. The signal read from the temporary storage memory 28 is decompressed by the AV encoder / decoder 30 and separated into audio and video signals. Each of the signals is converted into an analog audio signal and a video signal by a D / A converter (not shown). During recording, externally input data is compressed by the AV encoder / decoder 30, format processing for recording on the optical disk 22 is performed by the signal processing unit 14, laser modulation is performed by the preamplifier 26, and recording is performed on the optical disk 22. .

  Further, the speed signal of the optical disk 22 generated by the PLL circuit 54 of the preamplifier 26 is sent to the servo processor 16, and the rotation of the optical disk 22 is controlled by CLV by this speed signal. The rotational position signal from the Hall element of the spindle motor 20 is fed back to the servo processor 16, and FG control of constant rotation is also performed from the speed signal generated from this signal. The reproduction signal from the RF amplifier 50 is determined by an asymmetry detection circuit 70 to determine the position of the center position of the shortest signal 3T with respect to the peak and bottom amplitude positions of the longest signal 11T of the 8-16 modulation signal. Tell the result to the system controller. Asymmetry detection timing is controlled by a timing generation 73 described later. The servo error signal generation circuit 49 generates an address signal on the disk, an address detection circuit 73 that is a recording / reproduction timing signal, and a wobble signal that is a basis of a spindle speed signal and a clock signal at the time of recording. . The frequency signal obtained by the wobble detection circuit 72 is generated by the PLL 71 as a spindle speed signal and a recording clock signal. This signal is sent to a signal processing unit 14 that generates recording data and a timing generator 73 that will be described later. The address signal on the disk and the recording / reproduction timing signal obtained by the address detection circuit 73 are sent to the system controller 12 and the signal processing unit 14, and the recording / reproduction timing signal is used for test recording and for the area where test recording has been performed. Is sent to a timing generation circuit 74 which generates a timing signal for reproducing the image. The timing generation circuit 74 sends timing signals to the test pattern generation circuit 64, the system controller 12, and the signal processing unit 14 during recording, and generates timing signals for reproducing the area where the test recording has been performed, asymmetry detection circuit 70 and jitter generation circuit 56. Send to.

  The system controller 12 performs overall control of the above components. In addition, the microcomputer (not shown) recognizes key input and control data from the outside in order to separate high-speed scenes such as the resolution of the image to be recorded, car races, etc. In addition, the recording time can be changed by a switching terminal and settings can be selected by an external user.

  The optical pickup 24 uses a semiconductor laser as a light source, and forms a laser sbot on the optical disc 22 using a collimator lens, an objective lens, or the like (not shown). The semiconductor laser forms an APC (auto power control) circuit by inputting a feedback signal from a monitor diode for monitoring the emitted light of a laser (not shown) to the laser drive circuit 58, and the laser shown in FIG. Driven by the drive circuit 58, when an information signal is recorded, the input signal is corrected by the waveform correction circuit 60 and then input to the laser drive circuit 58. Here, the 8-16 modulation signal (write data) and the test pattern signal generated by the test pattern generation circuit 64 are switched and input by the switching circuit 62 as the input signal. The waveform correction circuit 60 is a circuit that converts an 8-16 modulation signal into a short pulse train (see, for example, Japanese Patent Laid-Open No. 3-185628 for a specific circuit configuration), and a laser drive circuit 58 with a short pulse train waveform. Is modulated, the recording waveform WA shown in FIG. 3B is obtained. Further, the waveform correction circuit 60 is a circuit for converting the pulse width to be short, and when the laser driving circuit 58 is modulated with the shortened waveform, the recording waveform WB of FIG. 3C is obtained.

  The waveform correction circuit 60 can be configured by a delay element and an AND circuit. That is, after the input signal is delayed by the delay element, the recording waveform WB shown in FIG. 3C is obtained by obtaining a logical product with the first input signal. In the waveform correction circuit 60, the time axis is switched in a large unit by the linear velocity switching circuit 62 based on the control of the system controller 12, and then the asymmetry value or the jitter value is optimized as will be described later. The detailed time setting of Ta, Tb, Tc, and Td in FIG. The feedback signal from the monitor diode described above is input to the A / D converter of the system controller 12 and can be monitored.

  Similarly, the test pattern generation circuit 64 switches the time axis in a large unit by switching the linear velocity, and as a pattern, a signal that alternately repeats 11T, which is the lowest frequency of 8-16 modulation, and 3T, which is the highest frequency, To do. FIG. 17 shows the structure of test recording data. Here, the recording data indicates that recording is performed at a location of the address A2 of the ECC block, and 11T is recorded in the B0 sector which is the first sector of one ECC block composed of 16 sectors, and 3T is recorded in the subsequent B1 sector. Then, 8 identical signals are written in units of 2 sectors. These eight recordings are recorded while switching eight types of recording power (P1, P2,...). When reproducing this, the system controller 12 determines this area, and then the signals T0, T1, T2, and T3 obtained by the timing generation 73 are used by the asymmetry detection circuit 70 to output the 11T signal in the B0 sector. The peak PDP1, the bottom PDB1, and the center PDC1 of the 3T signal are sample-held and A / D converted in the B1 sector, and transferred to the system controller 12. Although not shown, a temperature sensor such as a thermistor for detecting the temperature is provided in the vicinity of the optical disc 22, and a temperature detection circuit 66 for detecting the temperature is provided. As another configuration example of this circuit, a temperature characteristic of a forward voltage of a semiconductor, for example, a diode inside the preamplifier 26 may be measured.

When recording an information signal, the apparatus of this embodiment first irradiates a laser spot on the optical disk 22 and reads an address signal provided in advance in a signal track by an address reproducing circuit (not shown). Then, the linear velocity of the optical disk 22 is set by the system controller 12. For example,
(1) In the mode where the image quality is good but the total recording time is about 2 hours, the linear velocity is 6 m / s.
(2) In a mode in which the image quality is normal but the total recording time is about 4 hours, the linear velocity is 3 m / s.
(3) In a mode in which the image quality is poor but the total recording time is about 8 hours, the linear velocity can be selected to be 1.5 m / s.

  In addition, as described above, in addition to the case of separating scenes with high speed such as the resolution of the image to be recorded and car racing, etc., based on the key input for setting the recording time priority and the control data from the outside, The recording time can be changed by a switching terminal, or the recording time can be changed by selection by an external user. In practice, the compression ratio for compressing the input signal (information signal) is changed by the AV encoder / decoder 30 to change the transfer rate after compression of the input signal at the time of recording.

  Even if the linear velocity and the transfer rate after compression are changed as described above, the transfer rate of recording / reproduction with respect to the optical disc 22 is set faster than the transfer rate of the compressed signal to be recorded, and the difference due to this transfer rate is temporarily stored. The recording means (temporary storage memory 28) is configured to absorb. Although the CLV control is used here, the system controller 12 manages the track address position even when the linear velocity of the inner circumference and the outer circumference is changed to about 30 zones by CAV control or zone CAV control. However, it can be applied by setting the linear velocity at each position. In this case, a basic T cycle is set based on the set linear velocity.

  Next, the recording operation of the embodiment of the present invention will be described with reference to FIG. 12, FIG. 13 (a) and FIG. 13 (b). FIG. 12 shows temporal changes in the storage amount of the temporary storage memory 28, and a recording signal of the first transfer rate is written in the area a (period), and the signal written in the area b (period). Are read at a second transfer rate faster than the first transfer rate and recorded on the disc. FIG. 13 (a) and FIG. 13 (b) show the procedure of the operation as a flowchart. First, the operation when recording original data such as voice and video will be described. First, the recording mode, the reproduction mode, or the standby mode is determined. In the case of the recording mode (step SA), data (information signal) such as audio and video to be recorded is compressed by the AV encoder / decoder 30 and an error correction code, address, sync signal is outputted by the signal processing unit 14. Etc. are added and recorded in the temporary storage memory 28 (area a in FIG. 12, step SB). This operation is performed until the temporarily stored data reaches the full level (step SC). The full level value is set by a compression ratio mode at the time of recording or a mode set from the outside.

When the data storage amount in the temporary storage memory 28 reaches the full level (in the case of Y in step SC), this data is read from the temporary storage memory 28 and written to the optical disk 22 (b area in FIG. 12, step SD). ). This operation is performed until the temporary storage data in the temporary storage memory 28 reaches the empty level (step SE).
Then, when the empty level is reached (Y in step SE), data reading is stopped (step SF). At that time, the optical pickup 24 stops the data recording operation on the optical disk 22.

  In the embodiment of the present invention, for example, the waveform correction optimization process described later is executed after the optical disc 22 is set. When it is determined that the recording mode is selected, the system controller 12 can also determine whether the waveform correction optimization processing of the recording signal has been completed. If the waveform correction optimization process (hereinafter simply referred to as optimization process or optimization) is already performed during recording and the waveform correction optimization process is not required (N in step SG), the following is performed. The address to be recorded is stored, and the apparatus waits while kicking back at the track where the address to be recorded next exists, and returns to step SC. Note that step SG may be omitted when the waveform correction optimization process is executed each time, or when the waveform correction optimization process is performed only for a specific period.

  For step SG shown in FIG. 13A described above, for example, the waveform correction optimization process can be executed depending on whether a certain time has elapsed after the waveform correction optimization process is completed. As a specific example, as shown in FIG. 18, when the timer value becomes a predetermined value k or more (in the case of Y in step 101), the timer is reset (step 102), and FIG. The process proceeds to step SH shown in a). If the timer value does not exceed k (N in Step 101), the timer is counted up (Step 103), and the process returns to Step SC shown in FIG.

  Further, the above-described step SG shown in FIG. 13A is in a stage where recording is performed at a position at a predetermined distance from the position on the disc where the waveform correction optimization processing has been performed so far. It is also possible to execute the waveform correction optimization process depending on whether or not. As a specific example, when the new recording address is separated from the previously optimized address by a predetermined value as shown in FIG. 19 (in the case of Y in step 201), the address at this time is optimized. Is recorded (step 202), and the process proceeds to step SH shown in FIG. If the new recording address is not separated from the address previously optimized by waveform correction by a predetermined value (N in step 201), the process returns to step SC shown in FIG.

  Further, for step SG shown in FIG. 13A described above, for example, it is determined whether or not a predetermined temperature change has occurred, and when the temperature change exceeds a predetermined value, the waveform correction optimization process is performed. It is also possible to do. As a specific example, as shown in FIG. 20, if the current temperature is separated by a predetermined temperature from the temperature when the previous waveform correction optimization was performed (Y in step 301), the temperature at this time is optimized. The recorded temperature is recorded (step 302), and the process proceeds to step SH shown in FIG. If the current temperature is not separated by a predetermined temperature from the previous temperature correction optimization (in the case of N in step 301), the process returns to step SC shown in FIG.

  Further, with regard to step SG shown in FIG. 13A described above, as shown in FIG. 21, for example, when recording to the address A1 is completed by the optical pickup 24, the optical pickup 24 is kicked back into the area A1 ( Step 401) and reproducing the A1 address area (Step 402) and measuring the jitter or error rate in the A1 address area. If the jitter or error rate exceeds a predetermined value (Y in Step 403) ) Proceeds to step SH shown in FIG. 13A, and when the jitter or error rate does not exceed the predetermined value (N in step 403), the process returns to step SC shown in FIG. 13A again. It is also possible to return.

  Further, for step SG shown in FIG. 13A, for example, as shown in FIG. 22, it is determined whether the voltage of the feedback signal of the monitor diode described above has fluctuated by a predetermined value or more from the previous voltage. If the voltage fluctuates by a predetermined value or more (in the case of Y in step 501), this voltage value is recorded as the optimized voltage value (step 502), and the process proceeds to step SH shown in FIG. If it does not fluctuate by more than the value (in the case of N in step 501), it is possible to return to step SC shown in FIG.

  Whether or not the waveform correction optimization processing is performed is determined based on each of the above-described conditions alone, a plurality of conditions are logically combined, that is, when either the condition a or the condition b is met, It is also possible to make a determination when both the condition a and the condition b match, or to set a priority order for conditions such as determining the condition a with the highest priority. As an example of a combination of a plurality of conditions, for example, the waveform correction optimizing process is executed if any of the conditions is met according to the judgment shown by the chart in the flow shown in FIG. 18 (elapsed time) and FIG. 19 (recording address). 18 (elapsed time), FIG. 19 (recording address), FIG. 20 (temperature), FIG. 21 (jitter error rate), FIG. 22 (photodetector feedback voltage), etc. If these conditions are met, the waveform correction optimization process is executed, or the condition based on the judgment shown in the flowchart shown in FIG. 18 (elapsed time) and the condition based on the judgment shown in the flowchart shown in FIG. It is also possible to logically set a condition so that the waveform correction optimization process is executed when both match.

Further, when the condition based on the determination based on the flowchart shown in FIG. 18 (elapsed time) is met, the condition based on the determination based on the flowchart shown in FIG. 19 (recording address) or the condition based on the determination based on the flowchart shown in FIG. If either of these matches, the waveform correction optimization process can be executed. The above description of the conditions for executing the waveform correction optimization process is merely an example, and various other settings of the conditions for executing the waveform correction optimization process are possible as described above, including logical settings.

  Returning to FIG. 13 (a) again, when the waveform correction optimization process is necessary (in the case of Y in step SG), the address of the disk where data is to be recorded next is stored (step SH), and recording is performed. The test mode (step SI) is entered.

  The recording test mode process, which is the waveform correction optimization process, will be described below with reference to FIG. 13B and FIG. When the recording test mode (step SI) is entered, during recording of the next data in the temporary storage memory 28 (writing period), for example, the address of the disc whose recording was previously stopped is shown in FIG. When A1, the recording signal is switched to the test pattern signal at the address A2 subsequent to the address A1, and, for example, the test pattern signal for one ECC block 16 sectors (one sector is composed of, for example, 16 bytes of address and 2048 bytes of data) The address area of the address A2 on the optical disk 22 is confirmed (step SIa) and written continuously (step SIb).

  That is, 11T is recorded on the B0 sector, which is the first sector of one ECC block, and 3T is recorded on the B1 sector, followed by recording of 8 sets of 2 sectors, a total of 16 sectors. (Step SIb). The input of the switching circuit 62 shown in FIG. 10 is switched from the write data 8-16 modulation signal to a signal output from the test pattern generation circuit 64, whereby the test pattern signal output from the test pattern generation circuit 64 is converted into a waveform correction circuit. The laser is supplied to the laser drive circuit 58 via 60. The laser drive circuit 58 records the input test pattern signal on the optical disc 22. That is, test recording is performed at the address A2 following the address A1 recorded at the stage of SF. In this case, since recording is not stopped once, there is no waiting time such as waiting for a kick.

  As will be described later, the test pattern generation circuit 64 has at least one of the laser power of the recording power Pw and the erasing power Pe and the recording pulse widths Ta, Tb, Tc, Td for eight types (P1, P2,. A test pattern signal is generated while changing both settings. The pattern for changing the laser power is, for example, a monotonically increasing pattern, a monotonically decreasing pattern, a pattern that sequentially changes the level in the positive and negative directions around a predetermined value, a pattern that changes the level according to the detected temperature, and a recording position Select a pattern to change the level according to the time, or select from a plurality of patterns prepared in advance corresponding to the elapsed time from the previous recording, or change according to the situation, or a plurality according to the situation of the device It is also possible to selectively switch the patterns.

  Next, the optical pickup 24 kicks again to the A2 address of the recorded track (step SIc), reproduces the test signal of this track, and measures asymmetry (step SId). In the measurement, the signals T0, T1, T2, and T3 obtained by the timing generation circuit 74 are used to determine the peak PDP1 and bottom PDB1 of the 11T signal in the B0 sector and the center PDC1 of the 3T signal in the B1 sector by the asymmetry detection circuit 70. After smoothing with the LPF, sample hold and A / D conversion are performed, and the data is transferred to the system controller 12 and stored.

  FIG. 23 is a diagram illustrating an example of the asymmetry detection circuit 70. RF signals reproduced by the optical pickup 24 output from the RF amplifier 50 shown in FIG. 10 are input to a peak hold circuit 601, a bottom hold circuit 602, and a low pass filter (LPF) 603, respectively. Timing signals are supplied to the peak hold circuit 601, the bottom hold circuit 602, and the low-pass filter (LPF) 603 from the timing generation circuit 74 shown in FIG.

  The timing signal is supplied to the asymmetry detection circuit 70 by the timing generation circuit 74. The timing generation circuit 74 is supplied with a wobble signal output from the wobble detection circuit 72 and the PLL circuit 71 and a land pre-pit (LPP) signal output from the address detection circuit 73. For example, the wobble signal (for example, 140 kHz) shown in FIG. 24 reproduced from the disc is supplied to the timing generation circuit 73 as a signal multiplied by the recording clock signal (27 MHz), and the LPP signal shown in FIG. Is also supplied to the timing generation circuit 74. Since one sync frame signal is recorded in synchronization with the LPP signal, the timing generation circuit 74 counts on the basis of the recording clock signal with reference to the position of the LPP signal, thereby recording B0, B1,... A timing signal corresponding to the start position (T0, T1,... Shown in FIG. 17) can be generated.

The asymmetry detection circuit 70 refers to the timing signal described above and resets the peak hold circuit 601 and the bottom hold circuit 602 at the T0 time position. Next, the peak level from the peak hold circuit 601 that holds the peak level of the 11T signal reproduced from the B0 sector during the period from T0 to T1 and from the bottom hold circuit 602 that holds the bottom level of the 11T signal. The signal and the bottom level signal are sequentially read out at the time position T2, and the peak level signal and the bottom level signal converted into a digital signal by the A / D converter 604 are output to the system controller 12. Next, since the 3T signal reproduced from the B1 sector in the period from T1 to T2 is supplied to the LPF 603 and a smoothed signal (center value) is output, the peak level signal and the bottom level signal are read at the time position of T2. The 3T smoothing signal (center value) supplied to the A / D converter 604 and converted into a digital signal after being output or before being read out is also output to the system controller 12. Subsequently, the eight sets of signals recorded at different laser powers as described above are also supplied to the system controller 12 in the same manner.

In other words, this process is repeated, and the laser power value at the time when the center value of the 3T signal is almost centered with respect to the above-mentioned 11T peak value and bottom value is selected from the eight types of laser power values, and the value is optimized. The recording power Pw, erasing power Pe, and / or laser power values of Ta, Tb, Tc, and Td and / or pulse width are changed as values (step SIf). The system controller 12 determines whether or not the measured value is within a predetermined range from the peak level, bottom level, and center value output from the asymmetry detection circuit 70 (step SIe), and is set when it is outside the predetermined range (N). The waveform correction parameter is changed to the determined one and when it is within the predetermined range (Y), the waveform correction parameter is not changed. Thereafter, when the test signal measurement is completed (Y in step SIg), the process proceeds to step SJ shown in FIG. 13A, and when the measurement of the test signal is not completed (N), the process returns to step SId. Further, since the reproduction signal may fluctuate due to fluctuations in the reproduction signal due to device noise, optical disk 22 sensitivity irregularity, tracking servo status, etc., the peak hold and bottom hold are not limited to one point. By sampling a plurality of points during the measurement period and averaging the results, it is possible to absorb errors due to the above-described fluctuations and obtain more accurate measurement values.

  Here, for example, the measurement target may be replaced with an asymmetry value to measure jitter. In the case of jitter, the pattern of data to be recorded may be a normal random signal or data recorded before and after, and the recording is performed while changing the laser power value for each of the two sectors in the same manner, and these two sectors are recorded during reproduction. The jitter in the unit is measured at the same timing, and the above-mentioned laser power value corresponding to the value at which the measured jitter is minimized is changed as the optimum value and the power value for the next recording. More specifically, the waveform correction parameter, that is, Ta to Td of the waveform correction circuit 60 is changed as the laser power value. The Ta to Td of the waveform correction circuit 60 that is a waveform correction parameter may be changed using correction coefficients that are preliminarily compiled in a table corresponding to the tendency of the characteristics of the disk 22.

  The recording test mode process is performed, for example, as described in JP-A-7-153106, at least two lasers for recording and erasing at a predetermined address (for example, the area of the address A2 described above). Output a laser beam of power (for example, in the case of a phase change disk such as RW, three powers of reproduction, erasure and recording, and in the case of an organic dye disk such as R, output of two powers of reproduction and recording) The laser beam corresponding to the signal based on the 8-16 modulation is irradiated to a predetermined sector (for example, the above-described B0 sector) which is the first sector of one ECC block. In the case of reproduction power, the area on the optical disk is irradiated with reproduction power, in the case of erasing power, the signal is erased, in the case of recording, a predetermined recording signal is recorded, and for each laser power, the emitted light of the laser beam is emitted. The feedback signal of the monitor diode to be detected (monitored) is A / D converted, and this A / D converted signal is evaluated as a measured value by, for example, the system controller 12 and the difference between the measured value and the optimum value. For example, the intensity of the laser power is controlled so that the value decreases and approaches the target value. In this method, the sensitivity difference of the disk cannot be detected, but the fluctuation can be absorbed by detecting and correcting the fluctuation of the laser power due to the temperature characteristic of the laser and the change with time. Therefore, this method may be combined with the above-described control based on jitter or asymmetry measurement that can absorb the sensitivity difference of the disk and the like, the temperature characteristics of the laser, and the change with time.

  With respect to monitoring the laser beam being recorded, for example, when the recording test mode (step SI) is entered as shown in FIG. 25, the next data is being recorded in the temporary storage memory 28 (writing period). ), For example, the address A2 (FIG. 17) following the address A1 is confirmed (step SIA), and the test pattern signal as described above is recorded in the address A2 area. The laser beam emitted at the time of recording is monitored by the optical pickup 24, and the monitored signal is subjected to predetermined processing such as A / D conversion and then detected as a measurement value by the system controller (step SIB). The system controller 12 evaluates the measured value. If the evaluation result is within the predetermined range (Y in step SIC), the system controller 12 proceeds to step SJ, and if the evaluation result is out of the predetermined range (N in step SIC). The system controller 12 supplies a control signal to the waveform correction circuit 60, for example, and based on this control signal, the waveform correction circuit 60 and the laser drive circuit 58 have the optimum laser beam intensity of the laser light from the optical pickup 24. For example, the optical pickup 24 is driven by changing the waveform correction parameter as described above (step SID).

  The above-described operation in the recording test mode is performed within a time range from when the signal is accumulated in the temporary storage memory 28 until the full level is reached. That is, the waveform correction circuit 60 is set with the value of the waveform correction parameter at the time when the full level is reached. At the end of the recording test mode, the recording test mode is canceled, and the optical pickup 24 kicks back to the recording address A2 of the next data stored at the start (step SJ). Then, when the storage amount of the temporary storage memory 28 reaches the full level, the next data is recorded at the recording address A2 to be recorded next (steps SC and SD). Note that this recording connection uses a method called 0k (zero kilobyte) byte linking. The 0 kbyte linking is described in detail in Japanese Patent Application No. 10-310893 and Japanese Patent Application No. 10-310917. By this method, the previously recorded signal and the newly recorded signal can be continuously recorded at the boundary part of one ECC block at the time of reproduction at the time of reproduction, and an error within the range of ECC correction capability occurs at the time of reproduction. However, uncorrectable errors do not occur and can be reproduced continuously. Also, the test recording data is immediately overwritten by the data to be recorded next, and the test recording data is recorded by the same recording method as the recording signal of 8-16 modulation. The data area can be used efficiently without any occurrence.

  As described above, according to the embodiment of the present invention, the test pattern signal is recorded in the area to be recorded next by using the pickup idle time in the data (information signal) writing period to the temporary storage memory 28. Recording and reproduction are performed, and asymmetry and jitter of the reproduced signal are measured. Then, correction parameters relating to the intensity of the laser beam such as the recording power and the recording pulse waveform are set so that the asymmetry and the jitter become optimum values. Therefore, since the optimum value of the area to be recorded next is actually measured, the optimum value can always be found even when the optimum value is different due to a difference in recording sensitivity due to the difference in the inner and outer circumferences of the optical disk. In addition, it is not necessary to seek to the test recording area, and no time is required for setting a special waveform correction parameter, and data recording can be performed without giving a sense of incongruity to the user. In addition, since the area where this test pattern signal was recorded is overwritten during the next recording, it is not necessary to secure a special area for recording the test pattern signal, and recording with a laser beam of optimum intensity can be realized. It is.

  Further, in this method, test recording may always be performed during the idle time of the optical pickup during recording. In that case, for example, test recording / reproduction can be performed about once every 4 seconds. In addition, as described above, depending on the method for determining whether test recording is necessary or not, in vehicles such as in-vehicle and portable devices, recording is necessary even when the temperature changes rapidly, or a higher density is required. For example, when the recording conditions are slightly different due to variations in the recording temperature, output fluctuation due to temperature characteristics of the laser and changes over time, and variations in the inner and outer circumferences of the optical disc This method is effective for an apparatus that needs to update the optimum value in the area to be recorded. Further, depending on the device, the test recording may always be performed without determining whether or not the test recording is necessary.

In addition, this invention is not limited to the Example mentioned above at all, For example, the following are also included.
(1) In the temperature correction in the above-described embodiment, the temperature characteristic having a large influence on the recording characteristic shown in FIG. 5 is measured in advance by the temperature sensor. And the correction coefficient of said Ta-Td is corrected with this measured value. For example, when the measured temperature is 10 degrees, the disk 22 is unlikely to warm, so the direction is changed to increase Td with respect to Tc. When the temperature is as high as 40 ° C., the direction is changed to make Tc longer than Td.

  (2) In the embodiment described above, the asymmetry and jitter value of the reproduction signal of the test pattern signal are measured because the asymmetry and jitter value are related to the quality of the reproduction signal. For example, a high frequency component such as an RF signal, particularly its 3T signal, may be extracted and controlled so as to maximize this amplitude.

  (3) It is known that the phase change optical disk as in the above-described embodiment has a limit on the number of recordings, and jitter deteriorates as the number of times increases. Therefore, in a preferred embodiment, there is means for counting the number of recordings linked to the track, and this number of recordings is updated. As the number of times of recording increases, for example, the limit jitter value at the end of test recording is increased. Further, since the recording is changed so that the recording is not performed favorably as the number of times of recording increases, it is desirable to change the time from Ta to Td stepwise.

  (4) In the above embodiment, when the linear velocity which is the maximum transfer rate is 6 m / s as the waveform correction means, the signal waveform of FIG. 3C is used to simplify the recording signal generation circuit. . However, a plurality of different types of correction means may be used even at a linear velocity of 6 m / s.

  (5) In the above embodiment, as the waveform correction means, in the region where the linear velocity is low, the recording pulse is corrected to the pulse train composed of a plurality of short pulses, and then the signal is recorded, and in the region where the linear velocity is high, the recording pulse is shortened. Record the signal after correction. However, the optimal waveform correction may differ depending on the structure and type of the optical disc, and the waveform shown in the above form is not always the optimal correction. For example, in some cases, a method of correcting the waveform of a recording pulse to a pulse train composed of a plurality of short pulses regardless of the linear velocity is adopted, and the amplitude of the pulse of the short pulse train converted in the high linear velocity region and the slow region is changed. It is also possible to increase the phase margin in the entire area of the optical disk by, for example, increasing the amplitude of the tip in an area where the linear velocity is high, and such a correction method is also included in the present invention.

  (6) Regardless of the linear velocity, a method of correcting the waveform of the recording pulse to a pulse train composed of a plurality of short pulses is adopted, and the width of the pulse of the short pulse train converted in the high linear velocity region and the slow region can be changed. Good. For example, in the region where the linear velocity is low, the recording waveform is the recording waveform WE shown in FIG. 8A, and in the region where the linear velocity is high, the pulse width of the short pulse train of the recording waveform WE is widened as shown in the recording waveform WF in FIG. To. Since the heat storage effect during signal recording decreases as the linear velocity increases, the tear-like distortion does not increase even if the pulse width of the short pulse train is widened. When the pulse width of the short pulse train is widened, the energy supplied to the recording film increases, and as a result, the recording power can be reduced as compared with the case where the pulse width is narrow.

  Also in the recording waveforms WE and WF shown in FIG. 8, as in the recording waveforms WC and WD in FIG. 7, the laser power is made lower or lower than the erasing level before or after the recording pulse train, or corresponds to the recording pulse train. It goes without saying that the modulation may be made between the period, the recording power and the reproduction power level or the laser off level.

  (7) The above embodiment is a case where the present invention is applied to a single-layer disk. However, even in a disk such as a partial ROM or hybrid, the inner circumference has a ROM area and the outer circumference has a phase change RAM area. The same applies. For example, the current DVD standard is a read-only dual-layer disc, but as shown in FIG. 2, one layer is composed of a phase change recording film, or the whole is two layers and both layers are phase change. It is possible to use any one of the above-mentioned recording films, one layer being a read-only structure, etc. Similarly, the present invention can be applied to a disc having two or more layers. The apparatus configuration includes means for recognizing a multilayer disk, means for recognizing that at least one layer is a recordable layer, focus jump means for focusing on the signal surface of each layer, and a plurality of waveform correction means. The waveform correction value of the recording layer may be tested and stored.

  (8) The present invention can be similarly applied to an optical disc apparatus having no compression / decompression block, for example, a computer peripheral device such as a DVD-RAM or a DVD-RW. These devices record and reproduce compressed / decompressed data, but do not have a compression / decompression circuit as a device. For example, the compressed data is output to an external computer without being decompressed via a bus such as ATAPI or lEE1394, and decompressed by software on the computer. In order to optimize recording with a device controlled by such an external control input, whether the pickup is busy, such as during recording, playback, or seek, or unselected state to the disc. Monitoring is performed, and the waveform correction optimization process is performed when the state becomes the unselected state.

  (9) For this purpose, first, with the disk started, it is determined whether the type of disk, that is, single layer or multilayer, or whether there is a recording layer, depending on whether the disk is inserted or powered on. Then, it is determined whether there is a recording layer and whether recording optimization is necessary. The necessity of recording optimization is represented by a flag, for example. For example, when the power is turned on or the disk is inserted, the logical value is “0”, indicating that recording optimization is necessary. Once the optimization is completed, the flag becomes “1”. However, when a predetermined time has elapsed, or when a predetermined temperature change has occurred with respect to the temperature at the previous optimization, the flag is “0”. By looking at this flag, if there is a recording layer, the unselected state is monitored, and the waveform is optimized at that time. As a configuration, it has a focus jump means for focusing on the signal surface of each layer, and the waveform correction means may test and store the waveform correction values of a plurality of recording layers.

  (10) With a detachable disc, it is necessary to stably reproduce what was recorded on one device on another device. However, with the improvement in recording density, such stable reproduction has become difficult. The above-described mode is a case where optimum recording is performed within the own apparatus. A method for improving compatibility with other apparatuses will be described below. In such a case, by recording the waveform correction value on the disk, when the disk is started, if the correction value is referred to, there is no need to perform test recording again. Can be easily recorded.

  As a specific example, in the case of a DVD, the lead-in area is less than 24 mm in the innermost circumference of the disk. The data area after 24 mm is a data area. In the lead-in area, conventionally, the disc type (reproduction only, write-once, recording / reproduction type), layer (single-layer disc, two-layer disc, parallel, opposite), reflectance (single layer 0.7, double layer 0) .3), physical information such as the start address and end address of the data is described.

  In the embodiment of the present invention, in addition to these, for the recording / reproducing type, (b) optimum recording laser power (power is a laser such as Pw and Pe having a recording waveform as shown in FIG. 3B). (B) Optimal recording waveform correction value (the correction value basically indicates the temporal relationship of Ta to Td, which is the temporal profile of FIG. 3B. May record these four values, or may be a symbol that tabulates a set of a plurality of types of these values), (c) linear velocity, recording temperature (the above (a), ( (B) may be omitted), (d) a recording device (specifying the recording device when recorded on the market), (e) a manufacturer name (if recorded at the time of manufacture, the manufacturer of the disc) Only when disc recording is done on the market And (f) the device manufacturer is recorded corresponding to the data of (b) and (b)), (f) the production lot number of the product number (if recorded at the time of manufacture, only the disk number. Also recorded in the market. In this case, the disc manufacturer and the device number corresponding to the data (a) and (b) are recorded).

  (11) When recording is performed by the optical disc apparatus, the recorded data may be encrypted so that it cannot be read by other companies. In the case of a plurality of layers such as two layers, these data are specified. They may be recorded together in one layer.

  Such a disc recording / reproducing apparatus may be exactly the same as that described above, but test recording is performed in a test recording area prepared in the lead-in area as a test recording area. In addition to this area, any area may be used as long as the recorded data is not destroyed by normal data recording / reproduction. The recording / reproducing apparatus reproduces the test recording area and the like of the lead-in area and the waveform correction value at the first startup. If there is no waveform correction value, the recording test is performed to measure the optimum value of the waveform correction parameter, and this measured optimum value is encoded and written in the recording area. As a result, if the recording correction is performed by reproducing the optimum value after the next time, it is not necessary to perform the correction operation again. At this time, the mail name, the production lot number, and the like are confirmed, and, for example, the correction value reading method changes depending on the production lot.

  The same applies to the case where the correction value is recorded in advance on the disc. At the first start-up, the test recording area prepared in the lead-in area is reproduced and the waveform correction value is reproduced. Then, the correction value is reproduced by a decoder, and the waveform correction value is stored in a recording register by referring to the disk manufacturer name, production lot number, and the like. At the time of subsequent recording, data is written with this optimum waveform correction value.

(12) More specifically, the temperature at the time of measurement is measured by the temperature sensor, and this temperature value is recorded simultaneously with the correction value. The conditions such as linear velocity are recorded at the same time. Then, when these conditions are played back at the same time during playback and new recording is performed, parameters such as temperature and linear velocity at that time are compared, and if there is a difference between them, this difference is corrected. Correct the correction value from the calculation formula or table. Then, the corrected value is recorded as an optimum value.

(13) In the case of a two-layer disc or the like, if the recording area is on the first layer and the data on the second layer is written in a concentrated manner on the first layer, the processing at the time of reproduction is simplified. In this case, as in the case of a single layer, data for two layers is reproduced and set for each layer. However, when there is no data and a correction value is recorded, the recording test is first performed on the first layer, Measure the optimum value. Then, a focus jump is made to the second layer and the recording test is performed to measure the optimum value. Thereafter, the two data are encoded, moved to the recording area of the first layer, and the optimum value is written in this recording area. Thus, from this time onward, if this optimum value is reproduced and the recording correction is performed, it is not necessary to perform the correction work again.

As described above, here, it is described that three types of signals are recorded and evaluated as test recording signals. That means
Evaluation method A, 11T and 3T shown in FIG. 17 are recorded, and asymmetry is measured.
Evaluation method B, recording random signals and measuring jitter.
Evaluation method C, signals for reproduction, erasure, recording, etc. are recorded, and the feedback signal of the laser is measured.
The above three types.
In the high-density disc, the method for finding the optimum value is different among these three methods depending on the type of the optical disc. For example, before the processing shifts to the recording processing (step SA) in FIG. (A) The optimization method shown in the above (A) to (C) is selected according to the flowchart shown in (b).

That is, in the first method, as shown in FIG. 26A, the type of the optical disk is determined from information such as the difference in the reflectance of the disk at the time of activation (step SKa). For example, when it is determined that the disc is a DVD-RW disc based on the determination result, for example, the evaluation method B and the evaluation method C are selected. When the DVD-R is determined, for example, the evaluation method A and the evaluation method C are selected. Is selected (step SKb).
As described above, the evaluation method A and the evaluation method C, and the evaluation method B and the evaluation method C can be used, for example, by the detection means such as several kinds of positions and times, so that the moving distance from the position on the disk of the previous recording can be changed. When the distance is shorter than a predetermined distance, or when the elapsed time from the previous recording is shorter than the predetermined time, the evaluation method C is used to move the previous recording from the position on the disc. If is longer than the predetermined distance and the elapsed time from the previous recording is longer than the predetermined time, the processing procedure should be set in advance as evaluation method A or evaluation method B Is possible. It is also possible to set to perform only with the evaluation method A or the evaluation method B. The above-described example is an example of the present invention, and the present invention is not limited to this.

  In the second method, a predetermined area of the disc is reproduced as shown in FIG. 26B (step SKA), and specific information such as the disc manufacturer name, product number, and lot number is recorded in this predetermined area. This unique information is read (step SKB). In the recording apparatus, information relating to the association between the disc-specific information and the corresponding optimization method is recorded in the system controller 12 in advance, and the optimum method is determined based on the same concept as described above based on the comparison result. Based on this determination, optimization is performed during recording as described above (step SKC).

  The test pattern generation circuit 64 shown in FIG. 10 includes a function that enables random shift. This is configured to shift the recording data of the test signal to be recorded in one ECC block of the address A2 shown in FIG. 17 by about 6 bytes in the recording clock unit in the time axis direction. This shift amount can be set from the system controller 12. For example, when the system controller 12 first performs test recording in an unrecorded area, this amount is set to 0, and test recording is performed once in the area where the test signal is recorded. To do so, the system controller 12 generates a random signal to obtain a random value, which is shifted by that value and recorded. Then, the shifted signal is read, and the asymmetry is measured by shifting the read timing by the shift amount. In another embodiment, the test pattern generation circuit 64 shown in FIG. 10 has a function of inverting the 3T and 11T generation units. When recording with the data arrangement shown in FIG. 17 and recording a test signal for the second time, the data arrangement is inverted, such as a 3T signal in the B0 sector and an 11T signal in the B1 sector. By reversing this even number and odd number thereafter, the same effect can be obtained without deteriorating jitter because it coincides with the previous data during recording. Similarly, in the case of the evaluation method C, for example, erasure and recording signal are recorded first, then erasure and recording signal are recorded, and this is repeated to prevent signal quality deterioration.

  Note that the above description of the method explains that test recording is performed in the recording area to be recorded next, but not only in this case, but also a disc having a dedicated test recording area for determining the optimum power. Therefore, it is also effective for test recording in this dedicated area. Especially when the same signal is recorded every time as a test recording signal, it is highly probable that the signal quality will deteriorate. It is effective for.

  The method for detecting the optimum power in the dedicated test recording area is the same as the test recording and evaluation method in the area to be recorded as described above, and the description thereof will be omitted. When inserted, the optimum power is detected by moving to a dedicated test recording area, and in the subsequent recording, the optimum power is detected by test recording in the area to be recorded. Is also possible.

  Further, in this embodiment, the description has been made in which the three kinds of recording signals and the evaluation are performed separately. For example, three kinds of recording signals are simultaneously recorded, and one or two signals are evaluated at the time of evaluation. You can also do it. Further, for example, a method of recording two types of recording signals at the same time and evaluating one or two of them at the time of evaluation may be used. That is, the combination of evaluations can be changed as appropriate to the most suitable combination.

It is a recording waveform diagram which shows the fundamental effect | action of this invention. It is principal sectional drawing which shows an example of an optical disk. It is a figure which shows the recording waveform in one form of this invention. It is a figure which shows the relationship between the linear velocity and phase margin in various recording waveforms. It is a figure which shows the temperature fluctuation of the relationship between a linear velocity and a phase margin. It is a figure which shows the relationship between the linear velocity and recording power in various recording waveforms. It is a figure which shows the other recording waveform in this invention. It is a figure which shows the other recording waveform in this invention. It is a block diagram which shows the principal part of the optical disk apparatus concerning this form. FIG. 10 is a block diagram illustrating a configuration example of the preamplifier in FIG. 9. It is a figure which shows the disc form in DVD. It is a figure which shows the change of the memory | storage amount at the time of the data writing of a temporary memory. It is a flowchart which shows operation | movement of the Example of this invention. It is a figure which shows the change of the memory | storage amount at the time of data reading of a temporary memory. It is a figure which shows the mode of tearing of a recording mark. It is a figure which shows the mode of correction | amendment of the recording mark by a prior art. It is a figure for demonstrating operation | movement of the Example of this invention. It is a figure for demonstrating the 1st example of the waveform correction optimization process of the Example of this invention. It is a figure for demonstrating the 2nd example of the waveform correction optimization process of the Example of this invention. It is a figure for demonstrating the 3rd example of the waveform correction optimization process of the Example of this invention. It is a figure for demonstrating the 4th example of the waveform correction optimization process of the Example of this invention. It is a figure for demonstrating the 5th example of the waveform correction optimization process of the Example of this invention. It is a figure which shows an example of an asymmetry detection circuit. It is a figure for demonstrating operation | movement of a timing generation circuit. It is a flowchart which shows operation | movement of the other Example of this invention. It is a flowchart which shows the operation | movement for selecting the optimization method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Key input part 12 ... System controller 14 ... Signal processing part 16 ... Servo processor 18 ... Driver 20 ... Spindle motor 22 ... Disk 24 ... Pick-up 26 ... Preamplifier 28 ... Temporary memory 30 ... Decoder 49 ... Servo error signal generation circuit 50 ... Amplifier 52 ... Equalizer 54 ... PLL circuit 56 ... Jitter generation circuit 58 ... Laser drive circuit 60 ... Waveform correction circuit 62 ... Switching circuit 64 ... Test pattern generation circuit 66 ... Temperature detection circuit 70 ... Asymmetry detection circuit 71 ... PLL circuit 72 ... Wobble detection circuit 73 ... Address detection circuit 74 ... Timing generation circuit 601 ... Peak hold circuit 602 ... Bottom hold circuit 603 ... LPF
604 ... A / D converter

Claims (1)

When an information signal is recorded on an optical disk by a laser beam emitted from an optical pickup, writing is performed to temporarily store the information signal in a temporary storage unit, and then the information signal read from the temporary storage unit is recorded. In an optical disk recording / reproducing apparatus for
In the period of writing the information signal to the temporary storage means, a predetermined signal is recorded in the vicinity of the recording position of the optical disk to be recorded next, and the intensity of the laser beam is based on the result of evaluation. An optical disc recording / reproducing apparatus comprising a correcting means for optimizing the above.

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