JP2009064486A - Optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem: an optical disk device erroneously discriminates a loaded disk type in a conventional technique due to aberration deviation of a laser beam occurring when the disks having dispersion in physical characteristics between the disks, which is current tendency, are loaded in the optical disk device in which a photodetector has positional deviation caused by secular change or the like. <P>SOLUTION: Ratio values between a tracking error signal÷tracking sum signal are calculated from a tracking error signal at a focus balance value and a tracking error signal at ±10% of the focus balance value. Among the three calculated ratio values, the largest value is compared with a threshold value stored in a storage means, and the disk type is discriminated as DVD-ROM when the comparison result shows that the largest value is larger than the threshold value, and discriminated as DVD-R/RW when smaller. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an optical disc apparatus capable of recording / reproducing various optical discs, and more particularly to an optical disc apparatus having an optical disc discrimination method for judging the type of an optical disc loaded.

There are CDs, DVDs, etc. for optical disks, and there are a plurality of types such as ROM, R, RW for CDs and DVDs. Physical characteristics such as laser wavelength when recording on the body are greatly different, and disk characteristics such as reflectance, modulation degree, and track shape are also different. For this reason, in an optical disc apparatus that records or reproduces information on a plurality of types of optical discs, it is necessary to set parameters relating to the laser emission control circuit and parameters relating to the servo circuit corresponding to each disc. Therefore, it is necessary to accurately determine the type of the optical disc that the user intends to record or reproduce.
In the above-mentioned DVD-ROM and DVD-R / RW, DVD-ROM and DVD-R / RW are roughly classified by their characteristics, and these two types are discriminated, and parameters and servo circuits related to the laser emission control circuit are determined. If the related parameters are set, information can be normally recorded or reproduced on each optical disc.
Patent Document 1 includes means for detecting a tracking error signal, and uses the fact that the amount of fluctuation in the amplitude balance of the push-pull tracking error signal varies depending on the disc type, and the level of the obtained tracking error signal is set in advance. A method of discriminating the types of DVD-ROM and DVD-R / RW of an optical disc by comparing with the threshold value is disclosed. Specifically, it comprises means for generating a push-pull tracking error signal based on the received light signal output from the photodetector, and after performing the focus servo pull-in process, the objective lens is moved a predetermined distance in the radial direction of the optical disc, The push-pull tracking error signal modulation degree before and after moving the objective lens is acquired, and the obtained push-pull tracking error signal modulation degree is compared with a preset threshold value. A technique for discriminating R / RW, DVD-ROM if small is disclosed.
JP 2004-272989

However, with the recent popularization of optical disks, many disk manufacturers have newly entered, and the physical characteristics of the disks have become uneven, and these disks have misalignment of photodetectors due to secular changes, etc. When the optical disc apparatus is loaded, laser beam aberration deviation occurs, and the conventional technique still has a problem of discriminating the disc erroneously. In view of the above problems, an object of the present invention is to provide an optical disc apparatus having a discriminating method for reliably discriminating types of DVD-ROM and DVD-R / RW of an optical disc.

In order to solve the above problems, in an optical disc apparatus, a laser diode for irradiating an optical disc with laser light, an objective lens for condensing the laser light on the optical disc surface, and the optical disc of the laser light condensed by the objective lens A photodetector that generates a light reception signal based on reflected light from the light source, tracking sum signal generation means for calculating a total amount of the light reception signal output from the photodetector, and a light reception signal output from the photodetector. A tracking error signal generating means for generating a tracking error signal that is an error between the track following position of the objective lens and a predetermined track by a push-pull method, a tracking error amplitude calculating means for calculating the amplitude of the tracking error signal, Based on the tracking error signal, the objective lens is Tracking control means for controlling to follow the track on the track, and a focus error signal that is an error between the in-focus point of the objective lens and a predetermined position is generated based on the received light signal output from the photodetector A focus error signal generating means; a focus control means for allowing the objective lens to focus on the disk surface based on the focus error signal; and a storage device for storing a threshold value for determining the type of the optical disk; And a CPU for controlling each of the means, and the CPU adjusts the focus balance value by the focus control means, and after the focus is turned on, the value of tracking error signal amplitude ÷ tracking sum signal is increased. The focus balance value when the focus is turned on is calculated within a predetermined range The tracking error signal amplitude ÷ the value that increases the value of the tracking sum signal is compared with the threshold value stored in the storage means. If the comparison result is larger than the threshold value, the DVD-ROM is obtained. -R / RW is determined.
In the optical disc apparatus, the CPU adjusts the focus balance value by the focus control means and turns the focus on, and then changes the focus balance value when the focus is turned on step by step while dividing the tracking error signal amplitude by the tracking sum. The value of the signal is calculated, the tracking error signal amplitude ÷ the value at which the tracking sum signal is maximized is compared with the threshold value stored in the storage means, and if the comparison result is greater than the threshold value, the DVD-ROM If it is smaller, it is determined as DVD-R / RW.
In the optical disc apparatus, the CPU adjusts the focus balance value by the focus control means and turns on the focus, and then calculates the focus balance value and the value of the tracking error signal amplitude / tracking sum signal at ± 10% of the focus balance value. Each of the calculated three values is compared with the threshold value stored in the storage means, and if the comparison result is larger than the threshold value, it is DVD-ROM, and if it is smaller, DVD-R. / RW is determined.
In the optical disc apparatus, the focus balance value is calculated by (FEtop−FEbtm) ÷ (FEtop + FEbtm), where FEtop is the maximum value of the output signal from the focus error signal detecting means and FEbtm is the minimum value.
With the configuration as described above, the DVD-ROM and DVD-R / of the optical disc loaded in the optical disc apparatus are not affected by variations in the characteristics of the optical disc, or the positional deviation or aberration deviation of the photodetector in the optical disc apparatus. It acts so that classification with RW is possible.

The effect of the first aspect of the invention will be described below. When an optical disk is loaded into the optical disk device and the focus is turned on, the optical pickup is moved with respect to the vertical direction of the disk surface, the focus balance is adjusted, and the light is detected at the optimal focal point where the photodetector receives the largest amount of light. Stop picking up. At this time, if there is a deviation in the arrangement of the photodetectors or a deviation in the position of the laser diode, tracking, which is the focal point of the track with respect to the radial direction of the disk surface, is out of the optimum position. In this case, since a tracking error signal that is a parameter for disc discrimination is not correctly detected, there is a possibility that disc discrimination will occur. Therefore, while changing the focus balance value step by step, the value of tracking error signal amplitude / tracking sum signal is calculated, and disc discrimination is performed at the focus balance value at which the value becomes large, so that Discrimination between DVD-R / RW and DVD-ROM can be performed without being affected by the positional deviation and the positional deviation of the laser diode.
The effect of the second aspect of the invention will be described next. When an optical disk is loaded into the optical disk device and the focus is turned on, the optical pickup is moved with respect to the vertical direction of the disk surface, the focus balance is adjusted, and the light is detected at the optimal focal point where the photodetector receives the largest amount of light. Stop picking up. At this time, if there is a deviation in the arrangement of the photodetectors or a deviation in the position of the laser diode, the tracking, which is the focal point of the track with respect to the radial direction of the disk surface, is out of the optimum position. In this case, since a tracking error signal that is a parameter for disc discrimination is not correctly detected, there is a possibility that disc discrimination will occur. Therefore, by calculating the value of tracking error signal amplitude / tracking sum signal while changing the focus balance value stepwise, discriminating the disc at the focus balance value at which the value is maximized, the photo detector Thus, it is possible to reliably discriminate between DVD-R / RW and DVD-ROM without being affected by the positional deviation of the laser diode and the positional deviation of the laser diode.
The effect of the invention of claim 3 will be described next. When an optical disk is loaded into the optical disk device and the focus is turned on, the optical pickup is moved with respect to the vertical direction of the disk surface, the focus balance is adjusted, and the light is detected at the optimal focal point where the photodetector receives the largest amount of light. Stop picking up. At this time, if there is a deviation in the arrangement of the photodetectors or a deviation in the position of the laser diode, tracking, which is the focal point of the track with respect to the radial direction of the disk surface, is out of the optimum position. In this case, since a tracking error signal that is a parameter for disc discrimination is not correctly detected, there is a possibility that disc discrimination will occur. Therefore, the value of tracking error signal amplitude / tracking sum signal is calculated from the focus balance value and + 10% and -10% of the focus balance value, and the largest value among the calculated three values. And discriminating the disc by comparing the threshold value with DVD-R / RW and DVD- while reducing the processing time without being affected by the displacement of the photodetector or the displacement of the laser diode. The ROM can be discriminated.
According to the fourth aspect of the present invention, the focus balance value can be calculated from the focus error signal.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an optical disc apparatus according to an embodiment of the present invention. The configuration of the optical disc apparatus according to the present invention will be described with reference to FIG. As shown in FIG. 1, an optical disc apparatus according to the present invention transmits a spindle motor 102 for rotating an optical disc 101, a laser diode 118 that outputs laser light, and a laser beam output from the laser diode 118, which will be described later. The beam splitter 119 that reaches the objective lens 120, the laser light transmitted from the beam splitter 119 is condensed, reflected by the objective lens 120 for forming an optical spot on the optical disc 101, and the optical disc 101, and then passed through the objective lens 120. When there is no misalignment between the optical pickup 104 including the diffraction grating 121 for separating the light reflected by the beam splitter 119 and the photodetector 103 for detecting the light dispersed by the diffraction grating 121. Light beam spots and tracks based on the amount of information light in Here, tracking error signal generation means 105 for generating a tracking error signal (hereinafter referred to as a TE signal) by detecting a position shift with respect to the groove) by a push-pull method that corrects the position of the information light in the inner and outer peripheral directions by a change in the amount of information light; The tracking error signal amplitude calculating unit 122 for calculating the amplitude (hereinafter referred to as TEpp) of the tracking error signal output from the tracking error signal generating unit 105 and the TE signal output from the tracking error signal detecting unit 105 A tracking control means 106 for controlling the position of the light beam spot so that the light beam spot follows the track; a focus error signal generating means 107 for detecting a positional deviation between the light beam spot and the disk from the output of the photodetector 103; The output signal from the photodetector 103 A wobble signal detection means 108 for detecting a blue signal, a binarization means 109 for binarizing the wobble signal, a focus control means 110 for correcting out-of-focus based on an output from the focus error signal detection means, Reference clock generating means 111 for controlling the rotation of the spindle motor 102 and motor control for controlling the rotation of the spindle motor 102 based on the frequency of the wobble signal output from the binarizing means 109 and the output of the reference clock generating means 111 Means 112, clock generation means 113 for generating a bit clock at the time of recording from the binarized wobble signal, and recording data such as video data and audio data based on the bit clock output from the clock generation means 113. Recording processing means 114 for converting to the format of this, and this recording Based on the format conversion signal output from the processing means 114, a recording means 115 for converting into a predetermined recording waveform, a storage means 116 for storing parameters relating to each control, and a CPU 117 for controlling each means. Have. The movement of the optical pickup 104 in the inner and outer peripheral directions of the disk is controlled by the output signal of the tracking control means 106, and the movement of the optical pickup 104 in the vertical direction is controlled by the output signal of the focus control means 110. The optical pickup 104 records recording data such as video data and audio data on the disk 101 in accordance with the recording waveform signal output from the recording unit 115.
Next, FIG. 2 shows a detailed drawing of the optical pickup 104 of FIG. The optical pickup 104 in FIG. 1 will be described in more detail with reference to FIG. In the configuration example of FIG. 2, the optical pickup 104 includes a laser diode 118 serving as a light source, a beam splitter 119, an objective lens 120, a diffraction grating 121, and a photodetector 103 that detects light from the light receiving element 201. An objective lens driving device (not shown) that controls the position of the objective lens 120 in the optical axis direction (arrow m) is provided. Laser light emitted from the laser diode 118 passes through the beam splitter 119 and is focused by the objective lens 120 to form a light spot on the optical disc 101. The light reflected by the optical disc 101 is reflected by the beam splitter 119 through the objective lens 120 in the direction of the photodetector 103, split by the diffraction grating 121, enters the light receiving element 201, and is converted into an electric signal.
FIG. 3 shows a detailed drawing of the photodetector 103 of the optical pickup 104. The photodetector 103 will be described in detail with reference to FIG. The photodetector 103 is divided into four parts, the X axis indicates the radial direction of the optical disk, and the Y axis indicates the track direction of the optical disk. In the XY coordinates, a light receiving area a is arranged in the first quadrant, a light receiving area b is arranged in the second quadrant, a light receiving area c is arranged in the third quadrant, and a light receiving area d is arranged in the fourth quadrant. A is a detection signal detected in the light receiving area a, B is a detection signal detected in the light receiving area b, C is a detection signal detected in the light receiving area c, and D is a detection signal detected in the light receiving area d. . The TE signal is (A + D)-(B + C), and the focus error signal is (A + C)-(B + D). The state where the reflected light from the optical disc is incident evenly in the vertical direction around the X axis, that is, the state where the tracking error signal (A + D) − (B + C) becomes zero is the optimum state of tracking. In addition, a state in which reflected light from the optical disc is incident evenly from side to side about the Y axis, that is, a state in which (A + C) − (B + D) is zero is the optimum state of focus.
FIG. 4 shows the relationship between a cross-sectional view from the inner periphery to the outer periphery of the optical disc and the TE signal. With reference to FIG. 4, the relationship between the positional deviation of the photodetector and the TE signal will be described. FIG. 4A shows the relationship in DVD-R / RW, the cross-sections of which are almost the same, groove 401 as a groove for recording data, land 402 as a boundary between adjacent grooves 401, It consists of pits 403 that become data. Further, the reflectivity for reflecting the laser beam is high in the groove 401 and low in the land 402 and the pit 403. When the objective lens 120 is at the position 1, the laser beam is focused on the center of the groove 401. Therefore, the relationship between the amounts of light received by the four light receiving portions of the photodetector 103 is (A + D) = (B + C). The TE signal (A + D)-(B + C) at this time becomes zero. When the objective lens 120 is at the position 2, the laser light is equally collected on the groove 401 and the land 402 having completely different reflectivities, so that the amount of light received by the light receiving unit divided into four parts of the photodetector 103 is obtained. (A + D)> (B + C), and the tracking error signal at this time becomes maximum. When the objective lens 120 is at the position 3, the laser light is condensed at the center of the land 402. Therefore, the relationship between the amounts of light received by the four light receiving portions of the photodetector 103 is (A + D) = (B + C). At this time, the tracking error signal (A + D) − (B + C) becomes zero. When the objective lens 120 is at position 4, since the laser light is condensed on the grooves 401 and lands 402 having completely different reflectances, the amount of light received by the light receiving unit divided into four parts of the photodetector 103 is obtained. The relationship is (A + D) <(B + C), and the TE signal at this time is minimized. The optical disk has a minute eccentricity in any disk, and because of this eccentricity, the track continuously reciprocates the inner and outer circumferences on the radius, so the objective lens 120 transmits laser light to one groove. In order to collect light at the center, the states 1, 2, and 4 are repeated. By repeating such a state, the TE signal in (a) is obtained.
Next, FIG. 4B shows the relationship in the DVD-ROM, and the cross section thereof is different from the DVD-R / RW, and consists only of pits 403 which are data provided on the recording surface 404 for reproduction only. Further, the reflectivity for reflecting the laser beam is high on the recording surface 404 and low on the pit 403. When the objective lens 120 is at the position 5, the laser light is focused around the pit 403, and therefore the relationship between the amounts of light received by the four light receiving portions of the photodetector 103 is (A + D) = (B + C). The TE signal (A + D)-(B + C) at this time becomes zero. When the objective lens 120 is at position 6, the laser light is focused on each of the recording surface 404 and the pit 403 having completely different reflectivities. (A + D)> (B + C), and the TE signal at this time has a value close to the minimum. When the objective lens 120 is at the position 7, all the laser light is condensed on the recording surface 404. Therefore, the relationship between the amounts of light received by the four light receiving portions of the photodetector 103 is (A + D) = (B + C). The TE signal (A + D)-(B + C) at this time becomes zero. When the objective lens 120 is at the position 8, the laser light is focused on the recording surface 404 and the pit 403 having completely different reflectivities, so the relationship between the received light amount of the light receiving unit divided into four parts of the photodetector 103. (A + D) <(B + C), and the TE signal at this time has a value close to the maximum. Thus, the TE signal has a sine waveform that repeats peaks and valleys, and the tracking error signal amplitude calculating means 122 calculates the difference between the peaks and valleys, and calculates TEpp.
As described above, the physical structure of the DVD-R / RW is such that the areas of the grooves 401 and lands 402 having completely different reflectivities are provided equally, and the light received in the radial direction when the laser beam straddles them. Since the amount balance changes greatly, the amplitude of the TE signal increases. On the other hand, the physical structure of the DVD-ROM is provided with a recording surface 404 and pits 403 that have completely different reflectivities, but the area of the pit 403 is smaller than the area of the recording surface 404, so the laser beam straddles them. The balance change of the amount of received light in the radial direction is small, and the TE signal is smaller than that of DVD-R / RW. The prior art makes use of the above characteristics to discriminate between DVD-R / RW and DVD-ROM. With the recent widespread use of optical disks, the physical characteristics of the disks have changed. In these optical disc apparatuses having optical detector positional deviation due to secular change or the like, aberration deviation of laser light occurs, and there is a possibility that the type of the disc is erroneously determined in the conventional technology.
FIG. 5 shows the relationship between TEpp / tracking sum signal (hereinafter TS) and the focus balance value in each disk. The principle of disc discrimination according to the present invention will be described with reference to FIG. FIG. 5A shows the relationship between TEpp ÷ TS and the focus balance value when each optical disk is loaded in an optical disk apparatus without positional deviation of the photodetector (no aberration deviation). All of the disks have a relationship indicating a mountain-shaped waveform having a peak at a certain point, and the heights of the peaks increase in the order of DVD-ROM, DVD-RW, and DVD-R. Further, TEpp ÷ TS of each disk has a peak on the focus balance value line when the focus is on, which is represented by a vertical thick line in the graph. This is a state in which the focus is in the vertical direction with respect to the disk surface when the focus is on, and the focus balance relationship (A + C) − (B + D) of the four-divided light receiving area of the photodetector 103 is zero. In addition, focusing is also achieved in the radial direction of the disk, and focus and tracking are in good condition. In such a state, in order to discriminate between DVD-R / RW and DVD-ROM, the predetermined threshold value represented by a horizontal thick line in the graph, the focus balance value when the focus is turned on, and the characteristics of each disc are determined. This is possible by comparing the intersections of the curves to represent. As shown in the graph, the relationship between the intersection of the curve of each disk and the threshold value is clearly DVD-ROM <threshold value <DVD-R / RW, where DVD-ROM is smaller than the threshold value, and DVD-R is larger than the threshold value. / RW can be determined. Here, the reason why not only the TEpp but also the formula of TEpp ÷ TS is used for discriminating the disc type will be described. Even if the optical disk apparatus has the same design, the value of TEpp varies depending on the optical disk apparatus due to variations in the characteristics of the components constituting the optical disk apparatus and the mounting position shift of the photodetector that occurs in the production process. . For this reason, the threshold value when disc type is discriminated only by TEpp must be set to a large range in consideration of the above-mentioned variation, and setting a large range may cause erroneous discrimination. Also grows. Therefore, by utilizing the fact that TS has a tendency to vary as well as the tendency of TEpp variation, TEpp is divided by TS to obtain a ratio value, thereby making the correlation variation of each optical disc apparatus zero, and this ratio. By setting a threshold value as a judgment material, it is possible to reliably discriminate the disc type.
FIG. 5B shows the relationship between TEpp / TS and the focus balance value when each optical disc is loaded in an optical disc apparatus having a positional deviation (aberration deviation) of the photodetector. Similar to FIG. 5 (a), all the disks have a relationship indicating a mountain-shaped waveform having a peak at a certain point, and the peak heights are in the order of DVD-ROM, DVD-RW, and DVD-R. Although it is high, all the curves are shifted in the right direction as a whole with respect to the focus balance value when the focus is on, which is indicated by a vertical thick line. This is due to a positional deviation of the photodetector, and the relationship (A + C) − (B + D) of each light receiving area divided into four when the focus is turned on is zero, but the tracking is not in a good state, and the disk This is because the laser beam is displaced in any one of the radial directions. In such a case, A representing the intersection of the curve of DVD-RW and the vertical thick line of the focus balance value at the time of focus on is smaller than the threshold value represented by the horizontal thick line. Thus, in an optical disk apparatus having a photodetector misalignment, even if TEpp / TS is calculated from the focus balance value at the time of focus on and compared with the threshold value, the disk is erroneously determined.
Therefore, in this embodiment, the focus control is performed at ± 10% of the focus balance value at the time of focus on, and the tracking state is out of the balance (A + C) − (B + D) which is the balance in the vertical direction with respect to the disk surface. The better one, TEpp / TS, is calculated and compared with a threshold value to discriminate the disc. In FIG. 4B, in the focus balance value (vertical broken line) of ± 10% from the focus balance value (vertical thick line) at the time of focus on, the intersection with the disk curve at each point is + 10% focus balance value. The DVD-RW is larger than the threshold value, the DVD-R is also larger than the threshold value, the DVD-ROM is small, and the disc can be discriminated normally. In FIG. 4B, the case where the curve of each optical disk is shifted to the right as a whole is described. However, if the direction of the position shift of the photodetector is reversed, the curve of each optical disk is generally left. The disc can be normally discriminated when the focus balance value is adjusted to -10%.
Next, FIG. 6 shows a flowchart of the discrimination processing according to the present invention. The discrimination process of the present invention will be described with reference to FIG. The focus control means (110 in FIG. 1) moves the optical pickup (104 in FIG. 1) in a direction perpendicular to the disk surface of the optical disk (101 in FIG. 1), and a focus error signal generating means (107 in FIG. 1). The CPU (117 in FIG. 1) calculates the focus balance value based on the focus error signal output from (step S601). The focus balance value is calculated by (FEtop−FEbtm) ÷ (FEtop + FEbtm), where FEtop is the maximum value of the output signal from the focus error signal generation means (107 in FIG. 1) and FEbtm is the minimum value. Next, the focus control means (110 in FIG. 1) controls the focus position according to the calculated focus balance value, and then the CPU (117 in FIG. 1) calculates TS (step S602), and the focus balance value is calculated. TEpp / TS is calculated (step 603). Next, TEpp ÷ TS at a value of + 10% of the focus balance value is calculated (step S604), and then TEpp ÷ TS at a value of −10% of the focus balance value is calculated (step S605). Then, the largest value of the three TEpp / TS calculated in steps S603, S604, and S605 is compared with the threshold value stored in the storage means (116 in FIG. 1) (step S606), and the above value is obtained. CPU (117 in FIG. 1) determines whether or not is smaller than the threshold (step S607). If the determination result is small, it is determined that the loaded optical disk is a DVD-ROM (step S608), and the determination result is If it is larger, it is determined that the loaded optical disc is a DVD-R / RW (step S609).
In another embodiment of the present invention, the focus balance value is calculated within a predetermined range, a value where TEpp ÷ TS increases within the predetermined range is detected, and the disc type is determined by the magnitude relationship between the value and the threshold value. Make a decision. By adjusting the focus balance value and using a value for increasing TEpp ÷ TS as a parameter for disc type discrimination, disc discrimination can be made reliably. Note that if the range is too wide, the focus control will be lost, and the optical disc apparatus will be in a state where it cannot be reproduced or recorded. It is preferable to calculate.
In another embodiment of the present invention, the focus balance value is adjusted so that TEpp / TS is maximized, and the disc type is determined based on the magnitude relationship between the maximum value of TEpp / TS and the threshold value. By detecting the maximum value, the disc can be reliably discriminated, and the discrimination accuracy can be improved.
In the embodiment in which the focus balance value at the time of focus on and TEpp ÷ TS at ± 10% of the focus balance value are calculated and discriminated, the process of calculating the value of TEpp ÷ TS is three times. Therefore, it is possible to reduce the time required for disc discrimination processing.

The present invention is suitable for an optical disc apparatus having a function for discriminating the type of the optical disc, and particularly suitable for an optical disc apparatus having a function of discriminating the type of DVD-R / RW and DVD-ROM. is there.

1 is a block diagram of an optical disc apparatus according to the present invention. 1 shows a detailed drawing of an optical pickup according to the present invention. 1 represents a detailed drawing of a photodetector according to the present invention. The relationship between the cross-sectional view of the optical disk according to the present invention from the inner periphery to the outer periphery and the tracking error signal is shown. 4 shows a relationship between a tracking signal / tracking sum signal and a focus balance value in each disk according to the present invention. 3 shows a flowchart of discrimination processing according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Optical disk 103 Photo detector 105 Tracking error signal detection means 106 Tracking control means 107 Focus error signal detection means 110 Focus control means 116 Storage means 117 CPU
118 Laser diode 120 Objective lens 122 Focus error signal amplitude calculating means

Claims (4)

A laser diode for irradiating an optical disk with laser light, an objective lens for condensing the laser light on the optical disk surface, and a light reception signal based on the reflected light from the optical disk of the laser light condensed by the objective lens And a tracking sum signal generating means for calculating the total amount of received light signals output from the light detector, and a track of the objective lens by a push-pull method based on the received light signals output from the light detector. Tracking error signal generating means for generating a tracking error signal that is an error between the tracking position and a predetermined track, tracking error amplitude calculating means for calculating the amplitude of the tracking error signal, and the objective lens based on the tracking error signal A truck for controlling to follow a track on the disk. A king control means, a focus error signal generating means for generating a focus error signal that is an error between a focal point of the objective lens and a predetermined position based on a light reception signal output from the photodetector, and a focus error signal A focus control means for focusing the objective lens on the disk surface, a storage device for storing a threshold value for determining the type of the optical disk, and a CPU for controlling the means. In an optical disc device having
The CPU adjusts the focus balance value by the focus control means and after the focus is turned on, the focus balance value when the focus is turned on so that the value of the tracking error signal amplitude ÷ the tracking sum signal is increased within a predetermined range. Calculate and compare the value of the tracking error signal amplitude ÷ the value of the tracking sum signal with the threshold value stored in the storage means. If the comparison result is larger than the threshold value, it is DVD-ROM. An optical disc apparatus that is discriminated as a DVD-R / RW. The CPU adjusts the focus balance value by the focus control means and turns on the focus, and then changes the focus balance value when the focus is turned on step by step while changing the amplitude of the tracking error signal / the value of the tracking sum signal. Calculate and compare the value of the tracking error signal amplitude / maximum tracking sum signal with the threshold stored in the storage means. If the comparison result is larger than the threshold, DVD-ROM, and if smaller, DVD The optical disk device according to claim 1, wherein the optical disk device is determined as R / RW. The CPU, after adjusting the focus balance value by the focus control means and focusing on, calculates the value of the tracking error signal amplitude / tracking sum signal at ± 10% of the focus balance value and the focus balance value, respectively. The largest value among the calculated three values is compared with the threshold value stored in the storage means, and if the comparison result is larger than the threshold value, it is discriminated as DVD-ROM, and if it is smaller, it is discriminated as DVD-R / RW. An optical disc apparatus characterized by: 2. The optical disk according to claim 1, wherein the focus balance value is calculated by (FEtop−FEbtm) ÷ (FEtop + FEbtm), where FEtop is the maximum value of the output signal from the focus error signal detection means and FEbtm is the minimum value. apparatus.