WO2008035767A1

WO2008035767A1 - Optical disc recording and playback device

Info

Publication number: WO2008035767A1
Application number: PCT/JP2007/068407
Authority: WO
Inventors: Naoharu Yanagawa; Masataka Izawa
Original assignee: Pioneer Corporation
Priority date: 2006-09-21
Filing date: 2007-09-21
Publication date: 2008-03-27
Also published as: JP4490501B2; JPWO2008035767A1

Abstract

An optical disc recording and playback device (1) sets a condition on an optical system that is either the DVD or the HDDVD and turns on a light source of the disc under the set optical condition. Next, while moving an objective lens (36) in the vertical direction with respect to the disc surface of a mounted optical disc (2), an RF signal of light received from the optical disc (2) is binarized in accordance with a predetermined threshold value (an RF signal in a focusing depth defined at the focus point as the center is binarized by a predetermined threshold value). The device judges whether or not the binarized RF signal is a desired RF waveform (an RF waveform of the optical condition set disc). If the binarized RF signal is the desired RF waveform, the device judges that the mounted disc (2) is the optical condition set disc. However, if the binarized RF signal is not the desired RF waveform, the device judges that the mounted optical disc (2) is the second disc.

Description

Specification

Optical disc recording / reproducing apparatus

Technical field

[0001] The present invention relates to an optical disc discrimination technique for discriminating the type of an optical disc.

Background art

[0002] There are various types of optical discs currently in use, and an optical disc playback device (or optical disc recording / playback device) needs to be able to play back and record these various types of optical discs. . However, the recording density and track pitch are different for different types of optical discs, and the playback method is also different. For this reason, the optical disc playback apparatus needs to determine the type of the optical disc to be played back before starting the playback operation. Figure 1 shows a comparison table for NA (objective lens numerical aperture), substrate thickness, and light source wavelength of major optical discs.

By the way, as one of the methods for discriminating the type of the optical disc described above, there is a method for discriminating the type of the optical disc from the difference in the substrate thickness by measuring the substrate thickness of the optical disc. This method measures the time difference between the reflected signal from the surface of the optical disk (disk surface) and the reflected signal from the recording surface (recording layer), and discriminates the optical disk based on the measured value (for example, patent See references 1 and 2.)

[0004] Patent Document 1: Japanese Unexamined Patent Publication No. 2003-323716

Patent Document 2: Japanese Patent Laid-Open No. 2000-311427

Disclosure of the invention

Problems to be solved by the invention

[0005] The above-described method for measuring the substrate thickness of an optical disc to determine the type of the optical disc is an optical disc having the same base thickness, for example, DVD (Digital Versatile Disc) and HD DVD (High- There is a problem that the type of Definition Digital Versatile Disc cannot be determined.

[0006] In addition, in general, the method for discriminating the type of optical disc is often used to discriminate an optical disc by applying a focus servo. If it is inappropriate for the optical disk, it is necessary to change the condition of the set optical system, set it to the condition of another optical system, and apply the focus servo again. As a result, there is a problem that the time required for disc type determination becomes longer. This will be explained using Fig. 2.

FIG. 2 is a flowchart showing the flow of processing for discriminating the type of disk in the prior art. First, the optical system conditions for a predetermined type of optical disc are set, the loaded optical disc is rotated, and the light source is turned on (steps S10 and S20). Next, to apply the focus servo, the actuator is driven and the objective lens is moved up and down (step S30). If there is a return light amount above a certain level from the optical disc in step S30, the focus servo is operated and the tracking servo is operated (step S40). Next, disc discrimination is performed based on the signals obtained by the focus servo operation and tracking servo operation (step S50). If it is determined in step S50 that the loaded optical disc is not the optical disc of the optical system conditions that were initially set, the optical system conditions for another type of optical disc are set, and then again. Repeat steps S10 to S50. For this reason, it took time S to determine the type of optical disk. Note that if the track pitch is extremely different, the tracking servo is not turned on, so the optical system conditions for another type of optical disk may be set in step S40.

[0008] The present invention has been made to solve the above-mentioned problems. As an example of the problem, an optical disc recording / reproducing apparatus capable of discriminating types of optical discs having the same substrate thickness is provided. There is to do. An example of the problem is to provide an optical disk recording / reproducing apparatus that can quickly determine the type of an optical disk.

Means for solving the problem

In order to achieve the above object, the optical disc recording / reproducing apparatus according to claim 1 is an optical disc recording / reproducing apparatus provided with a medium discriminating unit that discriminates two or more types of optical discs, and the medium discriminating unit includes: Condition setting means for setting the conditions of one of the optical discs of the two or more types of optical discs, and rotating the mounted optical disc according to the set optical system conditions, and reproducing or playing the mounted optical disc Best to record An optical system starting means for turning on the light source for the first time; an objective lens moving means for moving the objective lens in a direction perpendicular to the disk surface of the mounted optical disk before operating the focus servo of the optical system; Based on the signal recording means for recording a predetermined signal including the RF signal received from the optical disk during the movement of the objective lens and the predetermined signal recorded by the signal recording means, the focal point is detected and detected. The binarization means that digitizes the RF signal within the focal depth centered on the in-focus point and the waveform of the digitized RF signal 1S Whether or not the signal waveform of the type of optical disc for which the optical system conditions are set And binarization determining means for determining whether the mounted optical disk is! / Or a deviation between the two or more types of optical disks.

[0010] Further, the optical disc recording / reproducing apparatus according to claim 3 is an optical disc recording / reproducing apparatus provided with a medium discriminating unit for discriminating two or more types of optical discs, wherein the medium discriminating unit includes the two or more types of optical discs. In addition to the disc rotational speed, in addition to the disc rotational speed, the condition setting means for setting the optical system conditions of the two or more types of optical discs and the set disc rotational speed conditions, Before operating the optical system starting means for rotating the mounted optical disk and simultaneously turning on the two or more light sources to reproduce or record the mounted optical disk, and operating the focus servo of the optical system An objective lens moving means for moving the objective lens in a direction perpendicular to the mounted optical disk, and the objective lens is being moved. And a signal recording means for recording a predetermined signal including an RF signal corresponding to each light source received from the optical disc, and based on each predetermined signal recorded by the signal recording means, The binarization means that detects the focal point and digitizes each RF signal within the depth of focus around the detected focal point, and the digitized waveform of each RF signal corresponds to the optical disc of the corresponding light source. And binarization determining means for determining whether the mounted optical disc is one of the two or more types of optical discs based on whether or not the waveform is a signal waveform.

Brief Description of Drawings

[0011] [Fig. 1] A comparison table of NA, substrate thickness and light source wavelength of main optical discs.

FIG. 2 is a flowchart showing a flow of processing for discriminating a disc type in the prior art It is.

3 is a schematic configuration diagram of the optical disc recording / reproducing apparatus according to the first embodiment of the present invention. FIG. 3 is a main configuration diagram of the pickup section shown in FIG.

FIG. 5 is a flowchart showing medium discrimination processing of the optical disc recording / reproducing apparatus according to the first embodiment of the present invention.

FIG. 6 is a flowchart showing in detail a binarization process in step S500 of FIG.

FIG. 7 is an RF signal obtained during UP / DOWN of the objective lens in the medium discrimination process of the optical disc recording / reproducing apparatus according to the first embodiment of the present invention.

FIG. 8 is a diagram showing in-focus, depth of focus, and threshold values for binarization processing in the RF signal and FE signal obtained by the medium discrimination processing of the optical disc recording / reproducing apparatus according to the first embodiment of the present invention. It is.

FIG. 9 is a diagram showing an output waveform of an RF signal when a DVD is played with a DVD light source and when a DVD is played with an HDDVD light source.

FIG. 10 is a diagram showing an output waveform of an RF signal when a DVD is played with an HDDVD light source and when an HDDVD is played with a DVD light source.

FIG. 11 is a flowchart showing a modified example of the medium discriminating process of the optical disc recording / reproducing apparatus according to the first embodiment of the present invention.

FIG. 12 is a flowchart showing a process of discriminating a read-only disk and an unrecorded recording disk in the medium discriminating process of the optical disc recording / reproducing apparatus according to the first embodiment of the present invention.

FIG. 13 is a flowchart showing medium discrimination processing of the optical disc recording / reproducing apparatus according to the second embodiment of the present invention.

14] This is an example of the configuration of the main part of the pickup section of the optical disc recording / reproducing apparatus according to the second embodiment of the present invention.

15] This is an example of a configuration of a main part of the pickup unit of the optical disc recording / reproducing apparatus according to the second embodiment of the present invention.

16] of the pickup unit of the optical disc recording / reproducing apparatus according to the second embodiment of the invention. It is an example of a principal part structure.

FIG. 17 is an example of a main configuration of a pickup unit of an optical disc recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 18 is a flowchart showing a modification of the medium discrimination process of the optical disc recording / reproducing apparatus according to the second embodiment of the present invention.

Explanation of symbols

[0012] 1, 10 Optical disc recording / reproducing apparatus

2 Optical disc

4 Signal processor

5 Control unit

6 Drive unit

7 Optical system switching part

31 and 32 optical discs (DVD, HDDVD, CD, BD)

33, 34 Collimator lens

35 PBS, Dyke Mouth Mirror

36 Objective lens

37 Wavelength transmission filter

38 Optical path switching polarization converter

P1 Focus

Δ 深度 depth of focus

L1 threshold

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0014] (First embodiment)

FIG. 3 is a diagram showing a schematic configuration of the optical disc recording / reproducing apparatus 1 according to the first embodiment of the present invention. The optical disc recording / reproducing apparatus 1 shown in FIG. 3 is an optical disc recording / reproducing apparatus capable of recording / reproducing two types of optical discs 2 having the same substrate thickness. It has a function to determine the type (medium) of disk 2. Here, the optical disc 2 having the same substrate thickness in the present embodiment is a power that can be described by taking DVD (Digital Versatile Disc) and HDDVD (High-Definition Digital Versatile Disc) as examples. Any optical disc with the same substrate thickness (distance from the disc surface to the recording surface) can be used!

[0015] The pickup unit 3 of the optical disc reproducing apparatus 1 is an optical pickup that reads a signal recorded on the optical disc 2, irradiates the optical disc 2 with laser light, and converts the reflected light into an electric signal. Are output to the signal processor 4.

[0016] The signal processing unit 4 performs waveform shaping processing, noise removal processing, digital conversion processing, and the like on the electrical signal, and outputs a reproduction signal (RF signal) to a reproduction circuit (not shown) or the like. . Further, the signal processing unit 12 generates a servo error signal (focus error (FE) signal, tracking error (TE) signal) from the above-described electrical signal and outputs the servo error signal to the control unit 5.

The control unit 5 performs movement control of the pickup unit 3, generates a servo error signal force, a drive signal for focus control and tracking control, and outputs the drive signal to the drive unit 6. It has become. In addition, the control unit 5 performs medium discrimination processing (details will be described later) for discriminating the type of the optical disc 2 when reproducing the mounted optical disc 2.

The drive unit 6 drives an actuator (not shown) in the pickup unit 3 based on the drive signal, and the pickup unit 3 (shown in the pickup! //! // objective lens) Is moved in a direction perpendicular to the disk surface of the optical disk 2, and the entire pickup unit 3 is moved in the radial direction of the optical disk 2.

[0019] The optical system switching unit 7 performs optical system switching control according to the type of the optical disk. In the present embodiment, the optical system conditions (light source, Aberration correction means, disk rotational speed, etc.) are set.

Next, the configuration of the main part of the pickup unit 3 will be described. FIG. 4 is a diagram showing a main configuration of the pickup unit 3. Specifically, the pickup unit 3 includes a DVD module 31 having a DVD light source (LD) and a photodetector (PD), and a HDDVD light source (LD) and a photodetector (PD). HDDVD module 32, DVD collimator lens 33, HDDVD collimator lens 34, PBS (Polarization Beam Splitter) 35, and objective lens 36

[0021] Laser light (wavelength: 650 nm) emitted from the light source of the DVD module 31 is converted into parallel light by the collimator lens 33, reflected by the PBS 35, and incident on the objective lens 36 to become a light beam. It is condensed on the recording surface. Further, the reflected light generated by irradiating the recording surface of the optical disc 2 with the light beam passes through the objective lens 36, is reflected by the PBS 35, and enters the photodetector of the DVD module 31 through the collimator lens 33.

On the other hand, laser light (wavelength: 405 nm) emitted from the light source of the HDDVD module 32 is converted into parallel light by the collimator lens 34, transmitted through the PBS 35, and incident on the objective lens 36 to become a light beam. The light is condensed on the recording surface of the optical disc 2. Further, the reflected light generated by irradiating the recording surface of the optical disc 2 with the light beam passes through the objective lens 36 and the PBS 35 and enters the photodetector of the HDDVD module 32 through the collimator lens 34.

In the present embodiment, the optical system switching unit 7 sets the optical system condition of either the DVD or the HDDVD selected by the control unit 5, so that the DVD module 31 or the HDDVD module 32! / The misalignment is working! /

Next, with reference to FIG. 5 and FIG. 6, the medium discriminating process in which the optical disc recording / reproducing apparatus 1 having the above-described configuration discriminates the type of the mounted optical disc 2 will be described. FIG. 5 is a flowchart showing the medium discrimination process of the optical disc recording / reproducing apparatus 1, and FIG. 6 is a flowchart showing in detail step S500 of FIG.

[0025] First, the optical disc recording / reproducing apparatus 1 sets conditions relating to the optical system of either DVD or HDDVD (step S100). Specifically, the settings are related to the light source, objective lens aberration correction, disc rotation speed, etc. For example, when DVD is selected, the aberration is adjusted to the DVD light source (650 nm) and DVD ΝΑ (0 · 6). Correction, DVD disc rotation speed (3. 49m / sec), etc. are set, and when HDDVD is selected, HDDVD light source (405nm), aberration correction matched to HDDVD) (0 · 65), HDDVD disc The rotation speed ( _6.61m / _SeC ) is set. In the following, the type of optical disc (DVD or HDDVD) for which the optical system conditions are set first is called the first disc. How to set up the first disk For example, the type of the optical disk 2 loaded last time may be set, or may be set by the user's selection, or may be set based on the past playback history. ! / (Set the type of optical disc 2).

Next, the optical disc recording / reproducing apparatus 1 rotates the mounted optical disc 2 according to the set disc rotation speed, and the light source of the first disc (light source of either the DVD module 31 or the HDDVD module 32) Is lit (steps S200 and S300).

Next, the optical disc recording / reproducing apparatus 1 moves, that is, moves up and down, the objective lens 36 in a direction perpendicular to the disc surface of the optical disc 2 (a direction approaching the disc surface and a direction away from the disc surface) (see FIG. Step S400). Then, during the vertical movement of the objective lens 36, the RF signal received from the optical disc 2 is binarized based on a predetermined threshold (step S500). The binarization process in step S500 will be described in detail with reference to FIG. In this embodiment, the objective lens 36 is first moved from the initial position in a direction approaching the disk surface (upward) and then moved away from the disk surface (downward). This will be described below.

[0028] First, in the process of raising the objective lens 36! / When the RF signal exceeds a certain level, the RF signal is input to the memory and the RF signal is recorded (step S510). ). Figure 7 (a) shows an example of the RF signal waveform input to the memory. FIG. 7 (b) is an enlarged view of the nearby waveform including the maximum value of the RF signal shown in FIG. 7 (a). In step S510, when the RF signal exceeds a certain level, the RF signal is input to the memory, but in addition to the RF signal, the FE signal may also be input to the memory! /.

[0029] Next, as shown in Fig. 8 (a), the RF signal output maximum position (position of RF return light amount MAX) is detected as the in-focus position (P1) from the RF signal input to the memory. To do. When the FE signal is input to the memory in step S510, as shown in Fig. 8 (b), the position where the output of the FE signal is zero (the position of the focus zero cross point) is the in-focus position (P1 ) May be detected.

[0030] Next, a threshold L1 for binarizing the RF signal is determined (step S530). Specifically, the threshold value L1 is a value obtained by subtracting half of the RF amplitude value at the position P1 from the maximum output value of the RF signal. Next, the depth of focus of the first disk is calculated (step S540). Here, since the depth of focus Δ Z is Δ Ζ = ± λ / 2ΝΑ ² (λ: wavelength, ΝΑ: numerical aperture), when the first disc is DV D, the depth of focus 厶 2 = ± 6501 111/2 0.6 ² = a ± 903Nm, when the second disk is HDDVD is a focal depth Δ Ζ = ± 405ηπι / 2 Χ 0 · 65 2 = ± 480nm.

[0032] Next, in the process of lowering the objective lens 36, the RF signal within the focal depth ΔZ is binarized based on the threshold L1 with the focus position (P1) as the center ( Step S550). This is because if the mounted optical disc 2 is the first disc in which the optical system conditions are set, in the region within the focal depth ΔZ centered on the position of the focal point (P 1), the desired optical disc 2 Based on the ability to play back the RF waveform (RF waveform of the first disc). Note that the position of the objective lens 36 is detected by an objective lens position sensor (not shown)! / (The position detection method is disclosed in, for example, Japanese Patent Laid-Open No. 5-114150 and Japanese Patent Laid-Open No. 11), the optical disk recording / reproducing apparatus 1 confirms that the objective lens 36 is located within the focal depth ΔZ centered on the position of the in-focus point (P1). Can figure out

Returning to FIG. 5, next, the optical disc recording / reproducing apparatus 1 determines whether or not the binarized RF signal has a desired RF waveform (RF waveform of the first disc) (step 1). S600). In the present embodiment, binarization is possible when the binarized RF signal has a desired RF waveform. Specifically, the desired RF waveform means that when the first disc is a DVD, the pulse width of the binarized RF waveform (digital signal) corresponds to 3T to 14T. Therefore, when the first disc is a DVD and the DVD optical system conditions are set, when a digital signal corresponding to a digital signal width of 3T to 14T is obtained, the loaded optical disc 2 can be determined to be a DVD. On the other hand, when the nore width of the digital signal is not the pulse width, it can be determined that the mounted optical disc 2 is not a DVD, that is, an HDDVD. Whether or not binarization is possible is determined using a known binarization determination circuit (for example, Morio Onoe, Noboru Murayama et al., “Optical Disc Technology”, Radio Inc. Technology, P. 190-193). Of course, various modifications are possible in the binarization judgment. For example, the RF signal (DC component) is divided by the RF signal (AC component). In this case, even if the waveform is binary, the RF amplitude is emphasized even if the RF signal is small.

In step S600, when binarization is possible (when the binarized RF signal has a desired RF waveform), it is determined that the mounted optical disc 2 is the first disc, With the optical system conditions for the first disk set, turn on the focus servo and tracking servo (step S1000).

On the other hand, in step S600, when binarization is not possible (when the binarized RF signal is not a desired RF waveform), the mounted optical disc 2 is not the first disc, The disc is determined to be the second disc, and the optical system conditions for the second disc are set (step S700). Next, the optical disc recording / reproducing apparatus 1 rotates the mounted optical disc 2 according to the disc rotation speed of the second disc, turns on the light source of the second disc (steps S800, S900), and performs focus servo. Then, turn on the tracking servo (step S1000).

It should be noted that the binarization processing shown in FIG. 6 is a force that assumes a flow assuming that the output of the RF signal (RF amplitude) is equal to or higher than a predetermined level. For example, the off-pit is sufficiently irradiated with a light beam. If an RF signal output cannot be obtained, the objective lens 36 is moved up and down again and the above steps S510 to S550 may be executed.

[0037] In addition, when processing for binary straight half IJ determination in steps S400 to S600 is performed between steps S900 and S1000, and if binarization can be determined, the process proceeds to step S1000. If binarization is impossible, a display may be made indicating that the optical disk is unknown, and the loaded optical disk 2 may be ejected. This is to support the standardization of new optical discs with the same substrate thickness other than DVD and HDDVD. That is, in this case, it can be applied to discriminating three or more types of optical disks having the same substrate thickness.

[0038] In the medium discrimination processing of the present embodiment, specifically, (l) when playing a DVD with a DVD light source, (l) when playing a DVD with an HDDVD light source, (3) HDDVD There are four ways to play HDDVD with a light source: (4) when playing HDDVD with a DVD light source.

FIG. 9 and FIG. 10 are diagrams showing output waveforms of RF signals in the above four cases. Fig. 9 (a ) Shows an RF signal when a DVD is played back with a DVD light source, and the binarized digital signal has a desired waveform (pulse width 3T to 14T). On the other hand, Fig. 9 (b) shows the RF signal when a DVD is played back with an HDDVD light source. The HDDVD light beam has a smaller beam diameter than that of the DVD, so it is not at the edge of the pit. Power and RF signal cannot be obtained. In other words, the binarized digital signal does not have the desired waveform (for example, the pulse width is 1T, 1.5Τ, etc.).

[0040] Fig. 10 (a) shows an RF signal when HDDVD is played back with an HDDVD light source, and the binarized digital signal has a desired waveform. On the other hand, Fig. 10 (b) shows the RF signal when HDDVD is played back with a DVD light source. Since the DVD optical beam has a larger beam diameter than HDDVD, only the long pit part has an RF signal. (Short pit part cannot get RF signal) and RF amplitude is small, so binarization is impossible (no binarization waveform as shown).

As described above, according to the optical disc recording / reproducing apparatus 1 of the present embodiment, the objective lens 36 is moved up and down before the force control and the tracking control are performed, and the obtained value is obtained during the up-and-down movement. Since the focal point (P1) is detected based on the RF signal or FE signal, the RF signal within the focal depth ΔΖ centered on the position of the focal point (P1) is binarized, and the type of optical disc 2 is discriminated. Even with optical disks having the same substrate thickness, such as DVD and HDDVD, the type of optical disk can be quickly determined.

[0042] (First modification of the first embodiment)

In the first embodiment, the light sources of the two types of optical disks (first disk and second disk) are sequentially turned on (when the first disk cannot be binarized) to determine the medium. In addition to this, the medium discrimination process may be performed by turning on the light sources of two types of optical disks at the same time. Hereinafter, a modified example of the medium determination process will be described with reference to FIG. FIG. 11 is a flowchart showing medium discrimination processing when the light sources of two types of optical disks are turned on simultaneously.

[0043] First, since the optical disk recording / reproducing apparatus 1 turns on the light sources of both DVD and HDDVD (light sources of both DVD module 31 and HDDVD module 32), the conditions concerning the optical system of both DVD and HDDVD are set. Set (Step S1100). This variant In the example, one of the types of optical disks set at the same time (one of DVD and HDDVD) is called the first disk, and the other is called the second disk (the other of DVD and HDDVD). Further, since both conditions cannot be set for the rotational speed of the disk, for example, the rotational speed for the first disk is set.

Next, the optical disk recording / reproducing apparatus 1 rotates the mounted optical disk 2 in accordance with the disk rotation speed of the first disk, and simultaneously turns both the light source of the first disk and the light source of the second disk. Lights up (steps S1200, S1300).

Next, the optical disk recording / reproducing apparatus 1 moves, that is, moves up and down, the objective lens 36 in a direction perpendicular to the disk surface of the optical disk 2 (a direction approaching the disk surface and a direction moving away from the disk surface) (see FIG. Step S 1400). Then, during the vertical movement of the objective lens 36, the RF signal received from the optical disc 2 is binarized based on a predetermined threshold (step S1500). In this modification, since the two light sources are turned on at the same time, both the RF signal for the first disc and the RF signal for the second disc (in both the photodetectors of the DVD module 31 and the HDDVD module 32). The detected RF signal) will be binarized. The binarization process in step S 1500 is the same as the binarization process flow in FIG. However, regarding the binarization processing of the second disk, the disk rotation speed is set to the rotation speed of the first disk, so the rotation speed of the first disk is a and the rotation speed of the second disk. When b is set to b, the binarization detection clock of the binarization judgment circuit is multiplied by b / a. Specifically, if the first disc is DVD and the second disc is HDDVD, b / a = 6. 61/3. 49, the first disc is HDDVD and the second disc is DVD. When set to b / a = 3. 49/6. 61.

Next, the optical disc recording / reproducing apparatus 1 determines whether or not the binarized RF signal has a desired RF waveform (step S 1600). That is, whether or not the binarized RF signal of the first disk has a desired RF waveform, and whether or not the binarized RF signal of the second disk has a desired RF waveform Determine whether or not. Since the loaded optical disk 2 is either the first disk or the second disk! /, The deviation is V, and one of the RF signals is the desired RF waveform, and V, the deviation is the other disk. The RF signal must have the desired RF waveform! /.

[0047] Of the first disk and the second disk, an optical disk that cannot be binarized is mounted. It is determined that the optical disk 2 has not been turned off, and the light source is turned off (step S 1700).

[0048] On the other hand, of the first disk and the second disk, for the binarizable optical disk, the rotation speed of the first disk (actual rotation speed) in which the rotation speed of the optical disk is set in step S1100. It is determined whether or not it is the same as the rotation speed of the spindle being operated (step S1 800). If the rotation speed of the binarizable optical disk is the same as the rotation speed of the first disk, it can be determined that the loaded optical disk 2 is the first disk, so the spindle rotation speed is set to the first rotation speed. With the disc rotation speed set, turn on the focus servo and tracking servo (step S2000). On the other hand, when the rotation speed of the binarizable optical disk is not the same as the rotation speed of the first disk, that is, the rotation speed of the second disk, the loaded optical disk 2 is Since it can be determined that it is a disk, set the rotation speed of the spindle to the rotation speed of the second disk, and turn on the focus servo and tracking servo (steps S1900, S2000).

[0049] Therefore, according to the present modification, the same medium determination processing as in the first embodiment can be performed even when the light sources of two types of optical disks are simultaneously turned on, so the first embodiment As described above, it is possible to quickly determine the type of an optical disk even for optical disks having the same substrate thickness, for example, DVD and HDDVD.

[0050] (Second modification of the first embodiment)

In the first embodiment, the reproduction-only optical disk (DVD-ROM, HDD VD-ROM) has been described as an optical disk to be discriminated S, the present invention is not limited to this, and the recording optical disk (DVD-R, DVD-RW, HDDVD-R, HDDVD-RW, etc.) may be added to the disc to be discriminated. Hereinafter, with reference to FIG. 12, a process for discriminating between a read-only disc and an unrecorded recording disc (hereinafter referred to as “playback / unrecorded recordable disc discriminating process”) will be described. FIG. 12 is a flowchart showing the reproduction “unrecorded recordable disc discrimination process. The reproduction“ record discrimination discriminating process is a process positioned as a step before step S510 in the binarization process of FIG.

First, the optical disc playback apparatus 1 determines whether or not an RF signal is input while the objective lens 36 is moving up or down (step S501). The pickup unit 3 is assumed to be positioned in the data area of the optical disc 2 as the initial position in the radial direction. [0052] When an RF signal is input while the objective lens 36 is raised or lowered, the optical disk is determined to be a reproduction-only optical disk (step S502), and thereafter, the process proceeds to step S510.

[0053] On the other hand, when an RF signal is not input while the objective lens 36 is raised or lowered, the pickup unit 3 is positioned at the innermost peripheral part inside the data area of the optical disc 2, and the objective lens is located at the position. It is determined whether or not an RF signal is input while 36 is rising or falling (steps S503 and S504). This is based on the fact that both the DVD and HDDVD recording optical discs are unrecorded discs, and RF signals are recorded on the innermost circumference of the optical disc. When the pickup unit 3 is positioned at the innermost periphery, the RF signal is detected by gradually changing the radial position of V in the innermost periphery. When the pickup unit 3 is positioned at the innermost periphery of the optical disc 2 and an RF signal is input while the objective lens 36 is raised or lowered, the optical disc 2 is determined to be a recording optical disc (step S505), and the process proceeds to step S510. move on. If no RF signal is input at the innermost periphery, the process ends as an unknown optical disk (displayed as Unknown Disc and ejects the loaded optical disk 2).

Note that in the case of a recorded recording disc, it may be determined as a read-only disc. Recorded recording discs have the same physical standard as playback-only discs and are compatible with each other.

[0055] Therefore, according to the present modification, it is possible to determine whether the read-only optical disk is an unrecorded recording optical disk by using only an RF signal without providing a new detection circuit. As for optical disks having the same substrate thickness, it is possible to discriminate between read-only optical disks and unrecorded recording optical disks.

[Second Embodiment]

Next, an optical disc recording / reproducing apparatus 10 according to the second embodiment will be described. An optical disk recording / reproducing apparatus 10 according to the present embodiment is an optical disk recording / reproducing apparatus capable of reproducing four types of optical disks 2 including two types of optical disks 2 having the same substrate thickness. A function for discriminating the type (medium) of the optical disc 2 is provided. Here, DVD (Digital Versatile Disc) and HDDVD (High-Definition Digital Versatile Disc) are described as examples of the optical disc 2 having the same substrate thickness in the present embodiment. 1S Not limited to this, any optical disk having the same substrate thickness (distance from the disk surface to the recording surface) may be used. The remaining two types of optical disks 2 include force S, which is exemplified by CD (Compact Disc) and BD (Blu-ray Disc), and two types of optical disks with the same substrate thickness. May be acceptable if the optical discs have different substrate thicknesses.

Note that the configuration of the optical disc recording / reproducing apparatus 10 is substantially the same as that of the optical disc recording / reproducing apparatus 1 except for the configuration of the pickup unit (substantially the same as FIG. 3), and thus the description thereof is omitted. Various variations are possible for the configuration of the main part of the pickup section, which will be described later.

Hereinafter, a medium determination process for determining the type of the optical disc 2 on which the optical disc recording / reproducing apparatus 10 is mounted will be described. FIG. 13 is a flowchart showing medium discrimination processing of the optical disc recording / reproducing apparatus 10. In the present embodiment, any one light source selected from the light sources of the four types of optical discs is turned on to perform the medium discrimination process.

[0059] The optical disc recording / reproducing apparatus 10 rotates the mounted optical disc 2 and turns on the light source on the basis of the set conditions relating to the optical system of a predetermined type of optical disc. To measure the substrate thickness of the mounted optical disk 2 (step S2100). The method for measuring the disk substrate thickness is based on a known predetermined method.

Next, the optical disc recording / reproducing apparatus 10 determines whether the measured substrate thickness of the optical disc 2 is a BD substrate thickness (0.1 mm, 0.075 mm) or a CD substrate thickness (1.2 mm). Or a substrate thickness (0 · 6 mm) of a DVD type (DVD and HDDVD! /, U) (step S 2 200).

[0061] When it is determined that the measured substrate thickness of the optical disc 2 is the BD substrate thickness, the type of the mounted optical disc 2 is BD, so that the optical disc recording / reproducing apparatus 10 is a BD optical system. In accordance with the set conditions, the optical disk 2 is rotated at the BD rotation speed, the BD light source is turned on, and then the focus servo and tracking servo are turned ON (steps S2300 to S2500, S2900). [0062] When it is determined that the measured substrate thickness of the optical disk 2 is the CD substrate thickness, the type of the mounted optical disk 2 is a CD. The system-related conditions are set, the optical disk 2 is rotated at the number of rotations of the CD according to the set conditions, the CD light source is turned on, and then the focus servo and tracking servo are turned on (steps S2600 to S2900).

[0063] When it is determined that the measured substrate thickness of the optical disc 2 is a DVD type substrate thickness, the optical disc recording / reproducing apparatus 10 performs a DVD / HDDVD determination process (step S3000). Here, the DVD / HDDVD determination process in step S3000 is the same as the medium determination process (steps S100 to S1000) in FIG. In step S3000, it is determined whether the mounted optical disk 2 is a DVD or HDDVD! /, So set the conditions related to the optical system of the determined optical disk, then focus servo and tracking. Turn on the servo.

Therefore, according to the present embodiment, the substrate thickness of the optical disc is measured and the medium discrimination process described in the first embodiment is applied to discriminate the type of the optical disc, so that the substrate thickness is the same. It is possible to quickly determine the type of four types of optical discs, including the two types of optical discs.

In the present embodiment, the disk substrate thickness measurement process (step S2100) and the binarization determination process (part of step S3000) are moved up and down with the force obtained in separate steps. In this case, the disk substrate thickness may be measured and the binarization determination process may be performed in the same step. In this case, in the process of this step, the force S is used to discriminate between BD, DVD, HDDVD, and CD.

Here, FIGS. 14 to 17 show examples of various configurations of the pickup unit of the optical disc recording / reproducing apparatus 10 according to the present embodiment.

The pickup unit 3A shown in FIG. 14 is a type that includes two objective lenses 36 and switches the objective lens 36 according to the light source. That is, since the objective lens 36A1 is an objective lens for HDDVD / DV D / CD and the objective lens 36A2 is an objective lens for BD, when turning on the light source for HDDVD / DVD / CD, the objective lens Switch to 36A1, When the light source for BD is turned on, it is switched to the objective lens 36A2. Note that the wavelength transmission filter 37A ;! to 3 can transmit only the laser beam having a wavelength corresponding to each light source, and the cross stroke can be removed when the light sources are simultaneously turned on. The collimator lens 33A3 is movable in the direction of the arrow, and can correct spherical aberration based on the difference in the substrate thickness of the optical disk (the collimating lens of the DVD can also be moved in the optical axis direction to Is also effective.)

The pickup unit 3B shown in FIG. 15 is a type that switches the optical path according to the light source. Specifically, laser light is emitted from the same BD / HDDVD module 31B3, and the optical path of BD and HD DVD is switched. In the case of HDDVD, objective lens 36B1 for HDDVD / DVD / CD, in the case of BD The BD objective lens 36B2 is transmitted therethrough. The optical path switching between BD and HDDVD is performed by the optical path switching polarizing element 38B for HDDVD / BD. The collimator lens 33B3 is movable in the direction of the arrow, and can correct spherical aberration based on the difference in the substrate thickness of the optical disk.

[0069] The pickup unit 3C shown in FIG. 16 includes a CD / DVD / BD / HDDVD compatible laser module 31C including a light source capable of emitting laser light of three wavelengths and a light detection unit capable of detecting laser light of three wavelengths. And two objective lenses 36C. That is, the objective lens 36C1 is an objective lens for HDDVD / DVD / CD, and the objective lens 36C2 is an objective lens for BD, so when turning on the light source for HDDVD / DVD / CD, When switching to the objective lens 36C1 and turning on the light source for BD, the objective lens 36C2 is switched. The collimator lens 33C is movable in the direction of the arrow, and can correct spherical aberration based on the difference in the substrate thickness of the optical disk.

A pickup unit 3D shown in FIG. 17 includes a CD / DVD / BD / HDDVD compatible laser module 31D including a light source capable of emitting laser light of three wavelengths and a light detection unit capable of detecting laser light of three wavelengths. And one objective lens 36D. That is, there is no need to switch the objective lens regardless of which light source is used. The collimator lens 33D is movable in the direction of the arrow, and can correct spherical aberration based on the difference in the substrate thickness of the optical disk. (Modification of Second Embodiment)

In the second embodiment, one of the four types of optical disc light sources is turned on and the medium discrimination processing is performed. Separately, the four types of optical disc light sources are turned on at the same time. A determination process may be performed. Hereinafter, a modified example of the medium determination process will be described with reference to FIG. FIG. 18 is a flowchart showing the medium discrimination process when the light sources of the four types of optical disks are turned on simultaneously. The optical disk recording / reproducing apparatus 10 of this modification will be described below assuming that it includes a pickup unit 3D having the configuration shown in FIG.

First, the optical disc recording / reproducing apparatus 10 sets conditions relating to the optical systems of all types of optical discs in order to simultaneously turn on all the light sources of the four types of optical discs (step S3100). Regarding the rotational speed of the optical disc, the conditions for any type of optical disc (referred to as the first disc) are set.

Next, the optical disk recording / reproducing apparatus 1 rotates the mounted optical disk 2 according to the disk rotation speed of the first disk, and turns on all the light sources (steps S3200, S3300).

Next, the optical disk recording / reproducing apparatus 1 moves, that is, moves up and down, the objective lens 36 in a direction perpendicular to the disk surface of the optical disk 2 (a direction approaching the disk surface and a direction moving away from the disk surface) ( Step S3400). Then, during the vertical movement of the objective lens 36, the substrate thickness of the mounted optical disk 2 is measured, and the RF signal received from the optical disk 2 is binarized based on a predetermined threshold (step S3500). Here, the method of measuring the disk substrate thickness is based on a known method. In addition, the binarization of the RF signal is performed only for the RF signal received by the DVD module and HDDVD module. This binarization process is the same as the binarization process flow of FIG. 6 described above, and a description thereof will be omitted. However, as in the first modification of the first embodiment (step S1500 in FIG. 11), it is necessary to change the binarization detection clock of the binarization determination circuit in accordance with the set disk rotation speed. There is.

Next, the optical disc recording / reproducing apparatus 10 determines whether the measured substrate thickness of the optical disc 2 is the BD substrate thickness (0.1 mm, 0.075 mm) or the CD substrate thickness (1.2 mm). Or DVD tie It is determined whether the thickness of the substrate (DVD and HDDVD! /) Is (0.6 mm) (step S3 600).

[0076] When it is determined that the measured substrate thickness of the optical disc 2 is the BD substrate thickness, the type of the mounted optical disc 2 is BD, so that the optical disc recording / reproducing apparatus 10 uses the BD optical system. In accordance with the set conditions, the optical disk 2 is rotated at the BD rotation speed, the light sources other than the BD are turned off, and the focus servo and tracking servo are turned on (steps S3700 to S3900, S4600).

[0077] When the measured substrate thickness of the optical disk 2 is determined to be the CD substrate thickness, the type of the mounted optical disk 2 is a CD. The system-related conditions are set, the optical disk 2 is rotated at the number of rotations of the CD according to the set conditions, the light sources other than the CD are turned off, and the focus servo and tracking servo are turned on (steps S4000 to S4200, S4600).

When it is determined that the measured substrate thickness of the optical disc 2 is a DVD-type substrate thickness, the optical disc recording / reproducing apparatus 10 performs a DVD / HDDVD determination process (step S4300). This DVD / HDDVD determination process is based on whether or not each of the binarized RF signals in step S3500 has a desired RF waveform. Specifically, the DVD module receives light from the DVD module. If the RF signal shows a DVD waveform, the mounted optical disk 2 is judged as a DVD, and if the RF signal received by the HDDVD module shows a HDD VD waveform, it is judged as an HDDVD. Then, the optical system conditions of the determined optical disk are set, the optical disk 2 is rotated at a desired number of rotations according to the set conditions, the light sources other than the determined optical disk are turned off, and the focus servo and Turn on the tracking servo (steps S4400 to S4600).

Note that in this modification, the medium determination process of the optical disc recording / reproducing apparatus 10 including the pickup unit 3D having the configuration illustrated in FIG. 17 has been described. However, the optical disc recording including the pickup unit having other configurations is described. Of course, the playback device 10 may be used. However, when the pickup units 3A to 3C are used, in the DVD and HDDVD determination process described above, both the RF signals received by both the DVD module and the HDDVD module may not be binarized. In this case, it is necessary to switch the objective lens 36 or the optical path. It becomes important. For example, in the case of the pickup unit 3A shown in FIG. 14, when the BD objective lens 36A2 is set, both cannot be binarized in the DVD and HDDVD determination processing. In the case of the pickup unit 3B shown in FIG. 15, when the laser beam emitted from the BD / HDDVD module 31B3 is set on the optical path for BD, both in the DV D and HDDVD determination processing, Both may not be binarized. In such a case, it is necessary to switch the objective lens 36 or the optical path and perform the DVD / HDDVD determination process again.

Therefore, according to this modification, the light source of the four types of optical disks is turned on simultaneously to measure the substrate thickness of the optical disk, and the medium discrimination described in the first modification of the first embodiment is performed. Since the type of the optical disc is discriminated by applying the processing, it is possible to quickly discriminate the types of four types of optical discs including two types of optical discs having the same substrate thickness.

While the embodiments and examples of the present invention have been described above, the present invention is not limited to the above-described embodiments and modifications, and the present invention is not limited to the scope of the present invention. Various modifications and changes can be made to the embodiments and examples of the invention.

[0082] For example, in the medium discrimination processing of the above-described embodiment and modification, the power used to binarize the RF signal within the focal depth and discriminate the type of the optical disc. Instead, the type of optical disk may be determined by measuring the position (range) where the RF signal exists. Specifically, for example, when HDDVD is played back with a DVD optical system, sufficient RF output cannot be obtained even within the focal depth. However, when a DVD is played back with a DVD optical system, it is shown in Fig. 7. Can be obtained (an RF signal having substantially the same amplitude within the depth of focus, and an RF signal whose output gradually decreases as the depth of focus is exceeded). Based on the appearing position, the type of the optical disk can be determined. In addition, when a DVD is played back using the HDDVD optical system, an RF signal with the same magnitude as the depth of focus can be obtained even if the depth of focus is exceeded (Figure 9 (b) within the depth of focus. As shown in Fig. 7), an RF signal with a short waveform width is obtained, and an RF signal with a long waveform width is obtained outside the depth of focus). (Within the depth of focus, almost the same vibration This is an RF signal having a width, and when the depth of focus is exceeded, an RF signal whose output gradually decreases is obtained), and the type of optical disc can be discriminated based on the position and magnitude of the RF signal. I'll do it.

Claims

The scope of the claims

[1] An optical disc recording / reproducing apparatus equipped with a medium discriminating means for discriminating two or more types of optical discs,

The medium determining means is

Condition setting means for setting the conditions of any one of the two or more optical discs;

In accordance with the set optical system conditions, an optical system starting means for rotating the mounted optical disk and turning on the light source first to reproduce or record the mounted optical disk,

An objective lens moving means for moving the objective lens in a direction perpendicular to the disk surface of the mounted optical disk before operating the focus servo of the optical system;

Signal recording means for recording a predetermined signal including an RF signal received from the optical disk during the movement of the objective lens;

Binarization means for detecting a focal point based on a predetermined signal recorded by the signal recording means and digitizing an RF signal within a focal depth centering on the detected focal point; Whether the mounted optical disc is one of the two or more types of optical discs based on whether the RF signal waveform is the signal waveform of the type of optical disc for which the optical system conditions are set Binarization judging means for judging

An optical disc recording / reproducing apparatus comprising:

[2] The condition setting means includes:

The type of optical disc selected by the user, the type of optical disc that was played last time, and the number of past playbacks were the most, based on the type of optical disc! 2. The optical disc recording / reproducing apparatus according to claim 1, wherein the condition is set.

[3] An optical disc recording / reproducing apparatus provided with a medium discriminating means for discriminating two or more types of optical discs,

The medium determining means is

In addition to setting the rotational speed of one of the two or more types of optical discs, the optical system conditions for the two or more types of optical discs are set other than the rotational speed of the disc. Condition setting means to be determined;

An optical system starting means for rotating and driving the mounted optical disc in accordance with the set disc rotation speed condition, and simultaneously lighting the two or more types of light sources for reproducing or recording the mounted optical disc;

Objective lens moving means for moving the objective lens in a direction perpendicular to the mounted optical disk before operating the focus servo of the optical system;

Signal recording means for recording a predetermined signal including an RF signal corresponding to each light source received from the optical disc during the movement of the objective lens;

Based on the respective predetermined signals recorded by the signal recording means, the binarization means detects the focal point and digitizes each RF signal within the focal depth around the detected focal point. When,

Based on whether each digitized RF signal waveform is the signal waveform of the corresponding optical disk or not, whether the loaded optical disk is one of the two or more types of optical disks Binarization judging means for judging

An optical disc recording / reproducing apparatus comprising:

[4] The binarizing means, for the optical disc of the type for which the disc rotation speed is not set among the two or more types of optical discs, sets the rotation speed of the optical disc of the type and the set disc rotation. 4. The optical disc recording / reproducing apparatus according to claim 3, wherein the digitization is performed in consideration of a ratio of the numbers.

[5] The predetermined signal includes a focus error signal,

4. The optical disc recording apparatus according to claim 1, wherein the focal point is detected based on a point where the value of the RF signal becomes maximum or a point where the value of the focus error signal becomes zero. Playback device.

[6] The binarization determination means includes threshold determination means for determining a threshold level for digitizing the RF signal based on an RF amplitude value at a point where the value of the RF signal is maximum. The optical disk recording / reproducing apparatus according to claim 1 or 3, wherein

[7] When the signal recording means does not receive the RF signal, the pickup unit including the objective lens is positioned on the inner peripheral part inside the data area of the mounted optical disk. A means for moving the inner periphery of the backup,

Based on whether or not the signal recording means has received an RF signal when the objective lens is positioned on the inner periphery, the mounted optical disk is an unrecorded recording disk. Disc discriminating means for discriminating whether the disc is a read-only disc,

The optical disk recording / reproducing apparatus according to claim 1, further comprising:

8. The optical disc recording / reproducing apparatus according to claim 1, wherein the two or more types of optical discs are optical discs having the same substrate thickness.

[9] An optical disc recording / reproducing apparatus comprising the medium discriminating unit according to claim 8, and discriminating three or more types of optical discs,

Substrate thickness measuring means for measuring the substrate thickness of the mounted optical disc;

First discriminating means for discriminating types of optical discs having different substrate thicknesses based on the substrate thickness measured by the substrate thickness measuring means;

When the first discriminating unit determines that the loaded optical disc is a displacement between two or more types of optical discs having the same substrate thickness, the medium discriminating unit is used to determine the type of optical disc. A second discriminating means for discriminating;

An optical disc recording / reproducing apparatus comprising: