JP4665972B2 - Optical disc apparatus and recording method for optical disc apparatus - Google Patents

Description

  The present invention relates to an optical disc apparatus that records and reproduces information on an optical disc, and a recording method of the optical disc apparatus that controls the relationship between the optical disc and the tilt and focus offset of an objective lens of an optical pickup.

  An optical disc cannot be completely formed in a flat concentric circle due to the limitation of its formation process. That is, on the market, there are optical discs in which the position of the center hole is shifted from the center, optical discs in which the outer peripheral side of the optical disc is warped, and the like. Recently, there is a medium called a printable medium that can print a label surface in an inkjet printer. In the printable media, a dedicated material for enabling printing with an ink jet printer is applied to the label surface, and the material has a property of expanding and contracting due to a temperature change. Therefore, the polycarbonate plate of the optical disk is stretched. As a result, the printable medium has a characteristic of warping in the radial direction of the optical disk due to a temperature change. In such an optical disk, since the laser irradiation method on the optical disk board surface is different with respect to a constant laser power, the optimum recording power for obtaining the optimum recording quality changes. Therefore, a process called running OPC has been established as a means for varying the recording power emitted from the laser and keeping the optimum recording power on the optical disk surface constant, and the entire surface of the optical disk warped from the time of optical disk formation. A process called tilt learning has been established.

  In the optical disc apparatus, a focus servo for keeping the distance between the objective lens and the optical disc constant so that the focal point of the laser beam condensed by the objective lens for recording and reproducing data is connected to the recording surface of the optical disc. It has a mechanism. This focus servo mechanism uses a balance of outputs from two reflected light detectors as an input, and focuses on the recording surface of the optical disc by keeping the balance constant. However, this input balance is shifted mainly due to an electrical offset caused by temperature fluctuation. This shift causes a change in the distance controlled by the focus servo mechanism. As a result, recording and reproduction are performed in a state where the focal point does not come on the recording surface of the optical disk. As a result, the amount of laser light per unit area must be reduced and the laser power must be increased. In order to prevent such a situation, reproduction is performed on the recorded area of the optical disc when the optical disc apparatus is started up, a focus offset value at which the jitter value is optimal is obtained, and a temperature variation is detected to detect a predetermined temperature variation. When this happens, the process of re-determining an appropriate focus offset value (focus position learning) is performed, but it is not performed during recording. Cannot be avoided.

  First, the configuration of a conventional optical disc apparatus will be described with reference to FIGS. 2, 3, 4, 13, and 14. FIG. 2 is a waveform diagram showing the reflected light from the optical disc during recording, FIG. 3 is a diagram showing the relationship between the warp in the radial direction of the optical disc and the objective lens of the optical disc apparatus, and FIG. 4 is a diagram showing the optical disc surface and the focal length of focus. 13 is a block diagram of tilt / focus control of a conventional objective lens, and FIG. 14 is a block diagram of laser control of a conventional optical disk apparatus.

  In FIG. 13, 101 is an optical disk, 102 is a pickup module, 103 is a spindle motor, 104 is a focus drive coil, 105 is an objective lens, 106 is focus drive means, 107 is focus control means, 108 is a tilt value calculation means, 109 is digital Servo controller. The whole surface tilt learning in the tilt control means configured as described above will be described with reference to FIG.

  When the optical disk 101 is inserted into the optical disk apparatus, the optical disk apparatus is moved to the focus driving means 106 by the focus control means 107 so that the laser emitted from the objective lens 105 in the pickup module 102 is focused on the optical disk 101. A signal is sent. The focus driving means 106 receives the signal and applies a constant current to the focus driving coil 104 to move the objective lens 105 up and down and apply focus servo. Thereafter, the spindle motor 103 is rotated to raise the optical disk to a desired rotational speed, and then the optical disk radial position 23 mm to 56 mm is equally divided into 8 points. The 8 points are divided into A, B, C from the inner peripheral position. , D, E, F, G, and H, the focus drive value that is the focal point at each position is acquired. These values are Af, Bf, Cf, Df, Ef, Ff, Gf, and Hf, respectively. First, in the first two points, A, B, and Af, Bf, the distance between the two points = B−A, and the focus drive value difference between them = Bf−Af, the height of the optical disk between B−A Since the difference is obtained, the warp angle of the optical disk between the two points A and B can be obtained by the tilt value calculation means 108 in the digital servo controller 109. Similarly, the warp angle on the entire surface of the optical disc is obtained by obtaining the optical disc warp angle between B-C and CD, and the tilt of the objective lens 105 is made perpendicular to the optical disc surface according to the result. To learn before performing a series of recording operations. In this way, learning for making the tilt of the objective lens 105 perpendicular to the optical disc board surface with respect to the warp existing when the optical disc shown in FIG.

  Next, focus position learning will be described.

  In FIG. 4, when a cross section of the optical disc 101 is viewed, it is composed of a protective layer 101a, a recording surface 101c on which data is recorded, and a recording layer 101b. When recording or reading data on the optical disc 101, it is necessary to adjust the focus 100 of the laser beam to the recording surface 101c as shown in FIG. 4A, and FIGS. ), It is not preferable that the focal point 100 is deviated from the recording surface 101c.

  When the optical disk is inserted, the optical disk device starts a startup process. At that time, when the objective lens is moved to an already recorded area of the optical disk and the recorded data is read, the jitter value is measured. Jitter measurement is performed for each of a plurality of points at the focus position, and the point at which the jitter is lowest is stored as the optimum focus in-focus position (FIG. 4A). If a temperature change is detected after the startup process, focus position learning is performed again based on jitter measurement.

  Next, a running OPC process for keeping the optimum recording power on the optical disk board constant will be described with reference to FIG.

  In FIG. 14, 101 is an optical disk, 102 is a pickup module, 103 is a spindle motor, 114 is a laser diode, 105 is an objective lens, 116 is reflected light receiving means, 117 is reflected light calculating means, 118 is reflected light detecting means, 119 Is a reflected light A / D conversion means, 120 is a reflected light A / D conversion value calculation means, 121 is a reflected light A / D conversion value comparison means, 122 is a laser power control means, 123 is a laser drive current conversion means, 124 Is laser driving means. The running OPC process configured as described above will be described.

  When recording on the optical disc 101 is started, the reflected light receiving means 116 in the optical pickup module 102 receives the reflected light from the optical disc 101. The reflected light calculation means 117 fully adds the signals received by the light receiving means, and generates a total reflected light signal (RF signal). The reflected light A / D conversion means 119 converts the voltage values of the levels A, B, C and level k of FIG. 2 of the RF signal detected by the reflected light detection means 118 into digital signals, and the reflected light A / D. The conversion value calculation means 120 calculates the amount of change in the thermal efficiency of the power applied to the optical disc 101 during recording. Here, levels A, B, and C in FIG. 2 are moments in which the organic dye of the optical disk is thermally decomposed by the heat of the laser power during recording, and the amount of reflected light decreases as the thermal decomposition proceeds. Therefore, if the efficiency of the recording power to the optical disk surface is good, it becomes level C, and if the efficiency becomes low, it rises to levels B and A. Therefore, the reflected light A / D conversion value comparison means 121 calculates the difference between levels A, B, and C in FIG. 2, calculates the power correction amount that cancels the difference, and supplies the correction power to the laser power control means 122. Output a signal. The laser power control means 122 outputs a digital signal that actually varies the laser power, is switched to a current value by the laser drive current conversion means 123, is transmitted to the laser drive means 124, and is transmitted to the laser inside the optical pickup module. By switching the laser power of the diode 114, the optimum recording power during recording is controlled to be constant.

As a prior example, there are (Patent Document 1) (Patent Document 2) and the like.
JP 2001-195663 A JP-A-5-114154

  In a conventional optical disc apparatus, when the recording is actually started after performing the entire tilt learning performed when the optical disc is inserted, the internal temperature is averaged over the entire surface of the optical disc due to self-heating of the IC inside the drive. The temperature rises by about 25 ° C. Here, in the above-described printable media, the entire tilt learning at the time of start-up is performed, and after the start of the entire recording, the optical disc starts to warp as the temperature rises during recording. The warped state is different from the result, and the positional relationship between the optical disk surface and the optical axis of the laser deviates from the vertical, and the mark formed on the optical disk is the mark formed on the conventional optical disk in FIG. As shown in the figure, the asymmetry characteristic reflecting the recording power characteristic shown in the graph showing the recording quality degradation when the conventional optical disk of FIG. As shown in FIG. 6, the recording quality deteriorates such that the number of reproduction errors increases on the outer peripheral side as it decreases on the outer peripheral side. There is a problem to say.

  Conventional focus position learning is a method for obtaining an optimum position based on a jitter value, but this cannot be performed during recording. During recording, the laser power is higher and the heat generation is greater than during reproduction, and the balance value that determines the focus position is shifted due to temperature fluctuations. Therefore, during recording, the recording is continued with the focus position shifted, and there is a problem that the recording quality deteriorates.

  Further, when optimum recording power control is performed using running OPC processing, the optical disc surface and the optical axis of the laser are not in a vertical relationship due to the warp accompanying the temperature rise in the printable medium, and the thermal efficiency of the laser is reduced. The level C in FIG. 2 rises to A and B levels, so the laser power is raised to suppress the amount of change. However, when the vertical relationship with the optical disc surface is significantly deviated, only an increase in laser power results in stronger formation of only one side of the mark to be formed as shown in FIG. Therefore, when reproduced after recording, one side of the mark is unclearly formed, so that there is a problem that reading errors are likely to occur when reproduced.

  When the focus position shifts, the running OPC mechanism detects a decrease in the thermal efficiency of the laser and increases the laser power. However, since the focal point does not come on the optical disk recording surface, the laser beam hits a wide range. End up. As a result, jitter is deteriorated during reproduction, which causes an increase in errors.

  Further, if the address information on the optical disk is a recording optical disk formed by wobbling the recording groove on the optical disk, the optical disk surface and the laser optical axis will return to the left and right of the groove when they are no longer in a vertical relationship. Since the light is different, as a result, there is a problem that the address information on the optical disc being recorded is not detected, and in the worst case, a recording error occurs.

  The present invention has been made to solve the above problems, and the positional relationship between the optical disc surface and the optical axis of the laser is perpendicular to the optical disc in which the amount of warpage changes as the temperature rises during the recording operation of the optical disc apparatus. Optical discs that do not cause a recording error due to the deterioration of recording quality and the address on the optical disc being recorded are not detected by avoiding deviation from the focus and avoiding the occurrence of focus position deviation due to temperature fluctuations. An object is to provide an apparatus.

In order to achieve the above object, an optical disk apparatus of the present invention is an optical disk apparatus that records data on a recordable optical disk using a light emission pattern of a laser beam, and includes an objective lens that focuses the laser beam, Tilting means for tilting the objective lens in the radial direction of the optical disc, driving means for moving the objective lens in the vertical direction from the current focus position to the optical disc board surface, and reflected light amount detecting means for detecting the reflected light amount of the reflected light from the optical disc; During the start-up process , the initial tilt value corresponding to the radial position and the temperature at that time are acquired in advance on the entire surface of the optical disc, and the start-up process is performed by tilting the objective lens without interrupting the recording at every predetermined radial position of the optical disc during recording. The initial tilt value obtained from time to time, the tilt value on the radially outer side of the optical disc relative to the initial tilt value, and the optical disc The amount of reflected light from the optical disk is detected at a plurality of tilt values on the radially inner peripheral side, the tilt value at which the reflected light amount is minimized is obtained, the temperature at that time is obtained, and the obtained tilt value is used as the reflected light amount. Is generated as a tilt value corresponding to the radial position of the optical disk in which the optical disk is detected, and tilt correction is performed, and an initial tilt value and temperature according to the radial position at the start-up process, and a tilt value according to a predetermined radial position during recording And storage means for storing a plurality of sets corresponding to temperatures, and the control means performs tilt correction for each predetermined radial position of the optical disk during recording, and then changes a plurality of movement values of the objective lens. The amount of movement that minimizes the amount of reflected light is detected by detecting the amount of light reflected from the optical disc, and the obtained movement value is calculated as the movement value corresponding to the radial position of the optical disc that detected the amount of reflected light Generated Te, characterized in that it proceeds by moving the driving means of the objective lens to the normal recording based on the generated movement value.

  According to the present invention, it is possible to avoid the deterioration of the recording quality by avoiding the occurrence of the focus position shift due to the temperature fluctuation, such as a printable medium that warps due to the internal temperature rise during the recording operation. Therefore, an optical disc apparatus capable of obtaining stable recording operation and recording quality can be realized.

The invention according to claim 1 of the present invention is an optical disc apparatus for recording data on a recording type optical disc by utilizing a light emission pattern of a laser beam. The objective lens for condensing the laser beam, and the objective lens as an optical disc and tilting means for tilting in a radial direction of the drive means for moving the objective lens on the optical disc board from the current focus position in the vertical direction, the reflected light amount detecting means for detecting the reflected light amount of the reflected light from the optical disk in advance when starting treatment The initial tilt value obtained according to the radial position on the entire surface of the optical disk and the temperature at that time are obtained, and the objective lens is tilted without interrupting the recording for each predetermined radial position of the optical disk during recording. The tilt value on the outer peripheral side in the radial direction of the optical disc and the tilt value on the inner peripheral side in the radial direction of the optical disc with respect to the tilt value and its initial tilt value Detects the amount of light reflected from the optical disk at multiple tilt values, finds the tilt value that minimizes the amount of reflected light, obtains the temperature at that time, and corresponds the calculated tilt value to the radial position of the optical disk from which the amount of reflected light is detected A control means for generating and correcting tilt as a tilt value, and a plurality of sets in which the initial tilt value and temperature corresponding to the radial position during the start-up process and the tilt value and temperature corresponding to the predetermined radial position during recording are associated with each other. Storage means for storing, and after performing tilt correction for each predetermined radial position of the optical disk during recording, the control means detects the amount of light reflected from the optical disk by changing a plurality of movement values of the objective lens. The movement value that minimizes the amount of light is obtained, and the obtained movement value is generated as a movement value corresponding to the radial position of the optical disc from which the reflected light amount is detected, and the movement generated Characterized in that it proceeds by moving the driving means of the objective lens to the normal recording based on.

According to the second aspect of the present invention, the initial tilt value corresponding to the radial position and the temperature at that time are acquired in advance over the entire surface of the recording type optical disc during the startup process, and laser light is emitted to the recording type optical disc. When recording, the laser beam is focused on the optical disc through the objective lens, the amount of reflected light from the optical disc is detected, and recording is not interrupted at every predetermined radial position of the optical disc during recording on the optical disc. The initial tilt value obtained during the startup process by tilting the body lens, and the tilt value on the radially outer peripheral side of the optical disc and the tilt value on the radially inner peripheral side of the optical disc with respect to the initial tilt value The amount of reflected light from the optical disk is detected, the tilt value at which the amount of reflected light is minimized is obtained, the temperature at that time is obtained, and the amount of reflected light is detected using the obtained tilt value. Generated as a tilt value corresponding to the radial position of the disc and corrected the tilt, and matched the initial tilt value and temperature according to the radial position during the start-up process and the tilt value and temperature corresponding to the predetermined radial position during recording. After storing multiple sets, change the multiple movement values of the objective lens with respect to the optical disk recording surface to detect the amount of reflected light from the optical disk, find a new focus value based on the movement value that minimizes the amount of reflected light, and create a new focus the value, generated by the focus value corresponding to the radial position of the optical disc detected amount of reflected light, by moving the objective lens based on the generated focus value is to transition to the normal recording.

(Embodiment 1)
FIG. 1 is a block diagram of tilt control and focus control of an optical disc apparatus according to an embodiment of the present invention. In FIG. 1, 101 is an optical disk, 102 is a pickup module, 103 is a spindle motor, 104 is a focus driving coil, 105 is an objective lens, 116 is a reflected light receiving means, 117 is a reflected light calculating means, 118 is a reflected light detecting means, 119 Is a reflected light A / D conversion means, 120 is a reflected light A / D conversion value calculation means, 121 is a reflected light A / D conversion value comparison means, 131 is a tilt / focus value calculation means, 107 is a focus control means, 106 is Focus drive means, 132 is a tilt correction result / disk radius position / temperature storage means, 133 is a tilt / focus control permission / prohibition recognition means, 109 is a digital servo controller, and 134 is a CPU.

  When the optical disk 101 is inserted, the optical disk apparatus rotates the spindle motor 103 and starts the activation process. At that time, when the objective lens 105 in the pickup module 102 is moved to an already recorded area of the optical disk and the recorded data is read, the jitter value is measured. Jitter measurement is performed for each of a plurality of points at the focus position, and the point with the lowest jitter is stored as the optimum focus position. If a temperature change is detected after the startup process, focus position learning is performed again based on jitter measurement.

  Next, the optical disc apparatus performs full-face tilt learning.

  When the focus position learning is completed, the optical disk apparatus equally divides the optical disk radial position from 23 mm to 56 mm into 8 points, and the 8 points are A, B, C, D, E, F, G, H from the inner peripheral position. In this case, the focus drive value that is the focal point at each position is acquired. These values are Af, Bf, Cf, Df, Ef, Ff, Gf, and Hf, respectively. First, at the first two points, A, B, and Af, Bf, the disk radius distance is determined by B−A, and the focus drive value difference therebetween is higher than the difference in height of the optical disk between B−A than Bf−Af. Therefore, the warp angle of the optical disk between two points A and B can be obtained. Similarly, by obtaining the optical disk warp angle between B and C, between C and D, the tilt value corresponding to the radial position is obtained in advance on the entire surface of the optical disk using the tilt / focus value calculation means 131. deep. Note that the optical disc apparatus acquires the temperature at the same time when the focus position learning and the entire surface tilt learning are performed.

  The optical disc apparatus shifts to a recording operation when a series of startup processes is completed. First, an OPC (optimum power calibration) operation for obtaining an optimum recording power to the optical disc is executed. In this operation, recording is performed while varying the recording power in a plurality of stages using an area existing for performing the OPC operation, which is called a PCA (power calibration area) area that exists further in the inner peripheral portion than the data area of the optical disk. Then, the recorded signal is reproduced, and the optimum recording power is calculated from the reproduced signal.

  The optical disc apparatus that has obtained the optimum recording power then starts data recording in the actual data area. When recording is started, a normal recording operation is performed for 100 ECC (1 ECC = 37856 bytes). When the 100 ECC recording is completed, the optical disc apparatus measures the amount of light reflected from the optical disc at the current tilt value (this value is obtained by the entire tilt learning at the time of activation). In the measurement, the reflected light obtained by the reflected light receiving means 116 of FIG. 1 is calculated by the reflected light calculating means 117, and only the necessary signal is detected by the reflected light detecting means 118. Subsequently, the reflected light signal obtained by the reflected light detection means 118 is A / D converted by the reflected light A / D conversion means 119, transmitted to the reflected light A / D conversion value calculation means 120, and has an initial tilt value. The reflected light quantity data is held in the tilt correction result / disk radius position / temperature storage means 132. During the time for sampling the reflected light, the reflected light for three rotations of the optical disk is acquired. By obtaining three rotations, the object is to eliminate data variation due to the surface blur component of the optical disc. Note that the tilt correction performed at the time of data recording is performed only in the data area, but it is realized by checking the table value indicating the tilt / focus control permission / prohibition state for the optical disc radial position in the tilt / focus control permission / prohibition recognition means. The In the case of acquiring the reflected light amount data at the initial tilt value, the table value is in the permitted state, so that the tilt / focus control at the time of acquiring the initial tilt value is recognized as permitted. Once the reflected light amount data value at the initial tilt value is obtained, the 0.025 ° objective lens is then tilted toward the outer peripheral side in the radial direction of the optical disc, and using the same means as when obtaining the reflected light amount at the initial tilt value, The reflected light amount is measured, and the reflected light amount data at that time is held. Subsequently, the objective lens is further tilted by 0.025 ° (0.05 ° with respect to the initial value) in the outer circumferential direction, and the reflected light amount is acquired and held using the same means as described above. Subsequently, the optical disc is tilted by 0.025 ° and 0.05 ° toward the inner periphery with respect to the radial direction of the optical disc, and the amount of reflected light is measured and held in the same manner as described above. At this point, when five reflected light amounts are obtained for the five tilt values, the optical disc apparatus acquires the current temperature.

  Next, the optical disc apparatus uses the reflected light A / D conversion value comparison means 121 to obtain the data of the five reflected light amounts obtained for the five tilt values with respect to the optical disc, the current objective lens, the optical disc surface, and the like. Is determined, and the tilt value having the most vertical relationship is learned. The learning method will be described with reference to FIGS.

  FIG. 7 is a diagram showing the amount of reflected light obtained when the tilt of the objective lens is not shifted when the tilt of the objective lens is shaken in the radial direction of the optical disc in the embodiment of the present invention. It shows the relationship between the amount of reflected light when ± 0.025 ° and ± 0.05 ° are varied, and the tilt variable amount at that time. FIG. 8 is a diagram showing the amount of reflected light obtained when the tilt of the objective lens is swung in the radial direction of the optical disc in the embodiment of the present invention. Note that + means tilting toward the outer peripheral side with respect to the radial position of the optical disc, and-means tilting toward the inner peripheral side.

  In general, the amount of light reflected from the optical disk is the most efficiently irradiated with the laser power when the positional relationship between the optical disk surface and the objective lens is vertical, and the amount of light reflected from the optical disk is the lowest. As the laser beam becomes worse, the heat of the laser is not transmitted efficiently, so the amount of reflected light increases. That is, if the initial tilt value is optimal, the characteristics shown in FIG. 7 can be obtained.

  Next, when the tilt is shifted, when the tilt value is varied by 5 points, only the five patterns shown in FIG. 8 exist. Here, the value of the reflected light amount at each tilt value is denoted by A to E as shown in FIG.

  The processing procedure will be described below with reference to FIG. FIG. 9 is a flowchart showing a process for correcting the tilt of the optical disk and the objective lens in the vertical relationship according to the embodiment of the present invention.

  The optical disk apparatus obtains the optical disk radial position at the recording start position (S1), and refers to the tilt / focus control permission / prohibition recognition table for the optical optical disk radial position in FIG. The prohibition recognition state is acquired (S2). When the tilt / focus control is prohibited, the tilt / focus processing is not performed. When the tilt / focus control is permitted, the following processing is performed.

  First, a comparison between the A value (current tilt value) and the B value (reflected light amount when the objective lens is tilted by 0.025 ° outward from the current tilt value) is made to the reflected light amount A / D conversion value comparison unit 121 in FIG. Do it. Here, when the A value is equal to or less than the B value, the three patterns 1, 4 and 5 in FIG. 8 are selected (S3). Next, the A value and the D value (the amount of reflected light when the objective lens 105 is tilted 0.025 ° inward from the current tilt value) are compared. Here, when the A value is smaller than the D value, the pattern 1 is obtained, and the initial tilt value is the most vertical in the positional relationship between the optical disc 101 and the objective lens. (S4). Next, when the D value is equal to or less than the A value, the pattern 4 or 5 is selected (S5), so the D value and the E value are compared. When the D value is smaller than the E value (the amount of reflected light when the objective lens 105 is tilted 0.05 ° inward from the current tilt value), the pattern 4 is obtained, and the optical disc 101 and the objective lens are tilted by −0.025 °. 105 is the portion closest to the vertical relationship, and a signal for moving the objective lens 105 to the inner peripheral side of 0.025 ° with respect to the initial value is transmitted from the focus control means 107 to the focus driving means, and the objective lens 105 The tilt amount is corrected (S6). Further, when the D value is equal to or greater than the E value, the pattern 5 is obtained, and a signal for moving the objective lens 105 to the inner peripheral side of 0.05 ° with respect to the initial tilt amount is driven by the focus control means 107 from the focus drive. Then, the tilt amount of the objective lens 105 is corrected (S7).

  Subsequently, as a result of comparing the A value and the B value, when the B value is small, patterns 2 and 3 in FIG. 8 are obtained (S8). Here, the B value and the C value (the amount of reflected light when the objective lens 105 is tilted outward from the current tilt value by 0.05 °) are compared, and when the B value is smaller than the C value, the pattern 2 is obtained and the initial value is set. On the other hand, a signal for moving the objective lens 105 to the outer peripheral side of 0.025 ° is transmitted from the focus control means 107 to the focus driving means, the tilt amount of the objective lens 105 is corrected (S9), and the B value is C When the value is larger than the value, pattern 3 is obtained. A signal for moving the objective lens 105 to the outer peripheral side of 0.05 ° with respect to the initial value is transmitted from the focus control means 107 to the focus driving means, and the tilt of the objective lens 105 is increased. The amount is corrected (S10).

  After completing the above processing, the optical disc apparatus obtains the current temperature, and the tilt correction result and disc radius in the table showing the tilt value obtained / not-stated, the tilt value, and the temperature at the time of tilt obtaining for the optical disc radius position in FIG. Acquired / not acquired in the position / temperature storage unit 132 is set and held, and the temperature at the time of the tilt value / tilt value acquisition process is held (S11). The processing is performed during the recording operation, and recording is not interrupted.

  The processing procedure will be described below with reference to FIG. FIG. 11 is a flowchart showing a process for correcting a focus in-focus position shift between the optical disc and the objective lens in the embodiment of the present invention.

  After the correction process for the tilt value is completed, the optical disc apparatus next performs a correction process for the in-focus position deviation with respect to the optical disc 101. With reference to FIG. 10, a description will be given of a correction process of the in-focus position deviation between the optical disc 101 and the objective lens 105. FIG. FIG. 10 is a diagram showing the amount of reflected light obtained when the focus position of the objective lens is swung in the vertical direction with respect to the optical disk surface in the embodiment of the present invention. The optical disc apparatus acquires the reflected light amount A with respect to the current focus value using the same means as in the tilt correction process (S12). Next, the objective lens 105 is moved upward by 0.06 μm, and the reflected light amount B at this time is acquired using the same means as in the tilt correction process (S13). Subsequently, the objective lens 105 is moved downward by 0.06 μm, and the reflected light amount C at this time is acquired using the same means as in the tilt correction process (S14). After the reflected light amounts at the three points are obtained, the in-focus position deviation is corrected based on the respective reflected light amount data. First, as a result of comparing the A value and the B value, when the B value is equal to or less than the A value, the pattern 3 in FIG. 10 is obtained, and the in-focus position is more when the objective lens 105 is moved upward by 0.06 μm. Therefore, a signal for moving the 0.06 μm objective lens 105 upward is output from the focus control means 106 to the focus drive means 107 (S15). If the B value is greater than the A value, the pattern 1 or 2 is obtained (S16), and the A value and the C value are compared. If the C value is large, the pattern 1 is obtained, and the current focus position may be the most in-focus position. In order to be found, no correction is made (S17). When the C value is less than or equal to the A value, the pattern 2 is obtained, and it is found that when the objective lens 105 is moved downward by 0.06 μm, it becomes the most in-focus position. A signal for moving down 0.06 μm is output from the focus control means 106 to the focus drive means 107 (S18).

  The processing procedure will be described below with reference to FIG. FIG. 12 is a flowchart showing processing for correcting the tilt of the optical disc and the objective lens to the vertical relationship again when the radial position changes in units of 1 mm in the embodiment of the present invention.

  After the output to the focus drive means is completed, the optical disk radial position is acquired while recording (S19). When a change in 1 mm units occurs, the tilt / focus control permission / prohibition recognition table for the optical disk radial position in FIG. Referring to the figure, the tilt / focus control permission / prohibition recognition state with respect to the optical disk radial position is acquired (S20). When the tilt / focus control is prohibited, the tilt / focus process is not performed, and when the tilt / focus control is permitted, the process returns to the start process of FIG. 9 (S21).

Here, when referring to the tilt / focus control permission / prohibition recognition table, tilt / focus control is permitted in the entire data recording area. The optical disc apparatus performs normal recording after performing tilt correction processing between the optical disc surface and the objective lens and in-focus position deviation correction processing. Then, when it is detected that the 1 mm objective lens has moved from the position where the previous processing was performed to the optical disc radial position, the same processing is performed again.

  In this way, tilt and focus correction processing is executed for each 1 mm radius position of the optical disk, and the tilt correction result is the tilt correction result / disk radius in the optical disk apparatus, together with the temperature and radius position when the correction process is performed. The table is managed in the position / temperature storage means 132, and the focus value is updated each time.

  At the end of recording, the temperature at the end of recording is acquired every time in order to perform temperature management in subsequent operations.

  Next, the case where a series of recording operations are completed and the operation proceeds to the reproduction operation will be described. In some cases, an optical disc apparatus is required to perform an operation of performing a process of reproducing an area recorded by itself after a series of recording operations. At this time, if the reproducing operation is performed immediately after the end of recording, there is almost no temperature change in the optical optical disc apparatus. Therefore, in the reproducing operation at this time, the result of the focus in-focus position correction performed during recording is obtained. The tilt correction result table obtained during recording is referred to depending on where in the radial position of the optical disc is used, and the playback operation is performed using the result. By doing so, it is possible to always reproduce with an optimum tilt value with respect to an optical disk which is warped with temperature fluctuation, represented by a printable optical disk.

  Next, a description will be given of a case where the temperature at the start of the reproduction operation fluctuates because the recording operation is completed and time elapses. In this case, the optical disc apparatus checks the current temperature and where the reproduction position is located in the optical disc radial position, and determines the optimum tilt value for the reproduction position as a result of the tilt correction process during the recording operation or during the start-up process. It is determined which of the results of the implemented entire face tilt learning value is optimal. For example, it is assumed that the reproduction operation position is the 40 mm position of the optical disk radial position. With respect to the tilt value, the tilt value A ° at the time of executing the entire face tilt learning is set, and the temperature at that time is set to 25 ° C. The result of the tilt correction processing performed at the 40 mm position during recording is B °, and the temperature at this time is 50 ° C. Here, the three items of 40 mm-B ° -50 ° C. mean that the values managed in the table in the tilt correction result / disk radius position / temperature storage means 132 of FIG. 1 are used. Under such conditions, when the temperature at the start of the reproduction operation is 30 ° C., the temperature of 25 ° C. is given priority because it is closer to 25 ° C. than 50 ° C. compared to 25 ° C. and 50 ° C. That is, as the tilt value when reproducing the 40 mm position at 30 ° C., the A value obtained by the entire tilt learning is used. Further, for example, when the temperature during the reproduction operation is 40 ° C., it is closer to 50 ° C. than 25 ° C. compared to 25 ° C. and 50 ° C., so the result B ° in the tilt correction process performed during recording is used. To do. This makes it possible to select a tilt value closer to the current temperature in a printable medium that warps due to temperature fluctuations, and the reproduction operation is stabilized.

  Next, a description will be given of a case where the optical disc apparatus performs the additional recording operation without inserting or removing the optical disc from the once recorded optical disc.

  When performing an additional recording operation on an optical disk once recorded by the optical disk apparatus, the optical disk apparatus acquires the current temperature and confirms where the additional recording start position is in the optical disk radial position. Next, if the temperature at the time of additional recording is within 10 ° C. compared to the temperature at the end of recording when the previous recording was performed, the radius on the inner peripheral side closest to the optical disk radial position to be additionally recorded The tilt correction result is referred to from the position table, and recording is started with the value as an initial value. Further, when the temperature is 10 ° C. or more away, the result of the entire tilt learning is used.

  It should be noted that whether or not the tilt correction processing and focus in-focus correction processing during recording can be performed for each optical disc radial position can be managed by software. In an optical disc that is not printable media and has almost no warpage, The processing load on the CPU is reduced by performing only a part of the CPU.

  With the above configuration, the optical disk apparatus avoids the positional relationship between the optical disk surface and the optical axis of the laser from deviating from the vertical relative to the optical disk whose amount of warpage changes as the temperature rises. By always placing the focal point of the laser light, it is possible to avoid a recording error due to a deterioration in recording quality or an address on the optical disc being recorded.

  INDUSTRIAL APPLICABILITY The present invention can be used for a recordable optical disc apparatus, and can realize an optical disc apparatus with high writing reliability and a recording method for the optical disc apparatus.

Block diagram of tilt control and focus control of an optical disc apparatus according to an embodiment of the present invention Waveform diagram showing reflected light from optical disc during recording Relationship between the warp in the radial direction of the optical disk and the objective lens of the optical disk device Diagram showing optical disc surface and focal length The figure which showed the mark in which the conventional optical disk was formed Graph showing degradation of recording quality when conventional optical disc is warped The figure which showed the amount of reflected light obtained when the tilt of the objective lens is shaken in the radial direction of the optical disc in the embodiment of the present invention and the tilt is not shifted The figure which showed the amount of reflected light obtained when the tilt of an objective lens was shaken in the optical disk radial direction in embodiment of this invention The flowchart which showed the process which correct | amends the tilt of an optical disk and an objective lens to perpendicular | vertical relationship in embodiment of this invention The figure which showed the amount of reflected light obtained when the focus position of an objective lens was shake | shifted up and down with respect to the optical disk board surface in embodiment of this invention The flowchart which showed the process which correct | amends the focus focus position shift | offset | difference of an optical disk and an objective lens in embodiment of this invention The flowchart which showed again the process which correct | amends the tilt of an optical disk and an objective lens to a perpendicular relationship when the radial position changes in 1 mm unit in embodiment of this invention. Tilt / focus control block diagram of a conventional optical disc apparatus Laser control block diagram of a conventional optical disc apparatus Table showing tilt / focus control permission / prohibition status for optical disk radial position Table showing tilt value acquired / not yet status, tilt value, and temperature at the time of tilt acquisition with respect to the optical disc radial position

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Focal point 101 Optical disk 101a Protective layer 101b Recording layer 101c Recording surface 102 Pickup module 103 Spindle motor 104 Focus drive coil 105 Objective lens 106 Focus drive means 107 Focus control means 108 Tilt value calculation means 109 Digital servo controller 114 Laser diode 116 Reflected light Light receiving means 117 Reflected light calculation means 118 Reflected light detection means 119 Reflected light A / D conversion means 120 Reflected light A / D conversion value calculation means 121 Reflected light A / D conversion value comparison means-The power control means 123 Laser drive current conversion means 124 laser drive means 131 tilt / focus value calculation means 132 tilt correction result / disk radius position / temperature storage means 133 tilt / focus control permission / prohibition recognition hand Stage 134 CPU

Claims (2)

An optical disk apparatus that records data using a laser light emission pattern with respect to a recording optical disk, and an objective lens that focuses the laser light;
Tilt means for tilting the objective lens in the radial direction of the optical disc;
Driving means for moving the objective lens in the vertical direction with respect to the optical disc surface from the current focus position;
A reflected light amount detecting means for detecting a reflected light amount of reflected light from the optical disc;
The initial tilt value corresponding to the radial position and the temperature at that time are acquired in advance on the entire surface of the optical disc during the startup process, and the objective lens is tilted without interrupting recording at every predetermined radial position of the optical disc during recording. With respect to the initial tilt value obtained during the start-up process and the initial tilt value, the tilt value on the radially outer periphery side of the optical disc and the tilt value on the radially inner periphery side of the optical disc are set to a plurality of tilt values from the optical disc. The amount of reflected light is detected, a tilt value that minimizes the amount of reflected light is obtained, the temperature at that time is obtained, and the obtained tilt value is generated as a tilt value corresponding to the radial position of the optical disc from which the amount of reflected light is detected. Control means for correcting the tilt,
Storage means for storing a plurality of sets in which the initial tilt value and temperature corresponding to the radial position at the start-up process and the tilt value and temperature corresponding to the predetermined radial position during recording are associated with each other;
The control means, after performing the tilt correction for each predetermined radial position of the optical disc during the recording , detects the amount of reflected light from the optical disc by changing a plurality of movement values of the objective lens, and the amount of reflected light is minimized. The obtained movement value is generated as a movement value corresponding to the radial position of the optical disc from which the amount of reflected light is detected, and the objective lens is moved by the driving unit based on the generated movement value. The optical disc apparatus is characterized by shifting to normal recording . During the startup process, the initial tilt value according to the radial position and the temperature at that time are obtained in advance on the entire surface of the recording optical disc,
When recording by emitting laser light to a recordable optical disc,
Condensing the laser beam on the optical disc through an objective lens;
Detecting the amount of reflected light from the optical disc,
The optical disc with respect to the initial tilt value obtained during the startup process by tilting the body lens without interrupting recording at every predetermined radial position of the optical disc during recording on the optical disc and the initial tilt value The amount of reflected light from the optical disc is detected at a plurality of tilt values of the radially outer peripheral side tilt value and the radially inner peripheral side tilt value of the optical disc, and the tilt value that minimizes the reflected light amount is obtained. The temperature is acquired, and the obtained tilt value is generated as a tilt value corresponding to the radial position of the optical disc from which the amount of reflected light is detected, and tilt correction is performed, and the initial tilt value corresponding to the radial position at the time of start processing and After storing a plurality of sets corresponding to the temperature and the tilt value corresponding to the predetermined radial position during recording and temperature ,
A plurality of movement values of the objective lens with respect to the optical disk recording surface are changed to detect a reflected light amount from the optical disk, and a new focus value is obtained based on a movement value that minimizes the reflected light amount, and the new focus value is reflected. control method for an optical disk apparatus characterized by generated by a focus value corresponding to the radial position of the optical disk that detects the amount, the process proceeds to the normal recording by moving the objective lens based on the focus values the product .

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