KR20130062766A - Optical disk device and method for operating thereof - Google Patents

Abstract

PURPOSE: An optical disk device and an operation method are provided to be stably operated by efficiently detecting noise. CONSTITUTION: An optical disk device(100) includes an optical pickup unit(200), an RF(Radio Frequency) processing unit(150), and a digital signal processing unit(160). The digital signal processing unit includes a decoder and an encoder. A control unit(110) distinguishes kinds of optical disks and reproduces data which is recorded in an optical disk in a reproduction mode corresponding to the kinds of the optical disks. The optical disk device includes a spindle motor(121), a driver(130), and a servo unit(140). [Reference numerals] (110) Control unit; (121) Spindle motor; (122) Sled motor; (130) Driver; (140) Servo unit; (150) RF processing unit; (170) Memory

Description

Optical disk device and method for operating thereof

The present invention relates to an optical disk device and an operation method thereof, and more particularly, to an optical disk device and an operation method thereof capable of accurately detecting noise and performing a stable operation.

An optical disk apparatus is a device for generating light from a light source to form pit information on a surface of an optical disk as a recording medium or to reproduce recorded data using light reflected from the formed pit information.

In this case, there are various types of recording media, but generally CDs (CDs) and DVDs (Digital Versatile Disks) are used, and blue can record data using a blue laser of short wavelength. Blu-ray disks (BDs) are used.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical disk device and a method of operating the same, which detect noise accurately and efficiently and operate stably.

 An optical disk apparatus according to an embodiment of the present invention includes an optical pickup unit and a optical disk including a light source unit including a plurality of light sources, an objective lens for condensing light emitted from the light source unit to an optical disk, and an optical detection unit for detecting light reflected from the optical disk. And a control unit for determining the type of the optical disc based on the type of the light source irradiating the light source and the order detected by the light detecting unit, and controlling to reproduce the data recorded on the optical disc in the reproducing mode corresponding to the type of the optical disc.

 An operating method of an optical disk device according to an embodiment of the present invention comprises the steps of sequentially condensing the light irradiated from a plurality of light sources to the optical disk, detecting the light reflected from the optical disk and the type and light of the light source to irradiate the light to the optical disk And determining the type of optical disc based on the order detected by the detection unit.

The optical disk apparatus and its operation method according to the present invention can detect noise accurately and efficiently and operate stably.

1 is a block diagram of an optical disk device according to an embodiment of the present invention.
2 is a perspective view of the optical pickup unit.
3 is a view showing an example of the configuration of an optical pickup unit.
4 is a view showing the configuration of an optical pickup unit according to an embodiment of the present invention.
5 to 8 are views referred to for explaining an optical disk device according to an embodiment of the present invention.
9 is a flowchart of a method of operating an optical disk device according to an embodiment of the present invention.
10 and 11 are views for explaining an operating method of the optical disk device according to the embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

1 is a block diagram of an optical disk device according to an embodiment of the present invention.

Referring to FIG. 1, the optical disc apparatus 100 directly records data on a recording medium 190, which is an optical disc, or reads by the optical pickup unit 200 and an optical pickup unit 200. It may include an RF processor 150 and a digital signal processor (DSP, 160) for receiving the received signal to restore to a desired signal value or to modulate and transmit the data to be recorded to the signal recorded on the recording medium (190) have. In addition, the RF processor 150 may format the signal detected by the optical pickup unit 200 to filter the signal and output the binary signal.

The digital signal processor (DSP) 160 may include a decoder and an encoder.

The decoder may decode the signal read from the recording medium 190 under the control of the controller 110 and restore the signal to desired information and provide the same to the user. The encoder converts an input signal into a signal of a specific format, for example, an MPEG 2 transport stream under the control of the controller 110, in order to perform a function of recording a signal on the recording medium 190. 150).

On the other hand, the recording medium 190 is largely read-only-memory (ROM), recordable (R) capable of recording information only once, and repeatable to repeatedly write, read, and erase information. There is a recordable (RE) optical disc.

In addition, the optical disk apparatus 100 may include a spindle motor 121 for rotating the recording medium 190, a sled motor 122 for moving the optical pickup unit 200, and a spindle motor 121 and a sled motor ( The driver 130 driving the driver 130, the tracking error signal TE and the focus error signal FE of the optical pickup unit 200, and the rotation speed of the recording medium 190 are driven. It may include a servo unit 140 for controlling.

In addition, the optical disc apparatus 100 may include a memory 170 that temporarily stores management information and data and a controller 110 that controls the aforementioned components.

The control unit 110 is responsible for the control of the above-described component, and refers to the user command and the like through the interface (interface) with the user, the recording and reproducing command for recording or reproducing data on the optical disc to the above-described component Will be sent.

In this case, there are various types of recording media, but CDs (CDs) and Digital Versatile Disks (DVDs) are generally used. Up to 27GB can be recorded using a blue laser having a short wavelength. Blu-ray Disk (BD) is used.

2 is a view showing a general optical pickup unit.

Referring to the drawings, a general optical pickup unit includes a light source unit 210 for generating light of a specific wavelength, a tracking light forming unit 220 for dividing the generated light, light transmitted to a recording medium, and light reflected from the recording medium. Optical separation unit 230 for separating, the collimating lens 240 to make the light source output from the light source on the path transmitted to the recording medium in parallel light, the path changing mirror 250 for changing the path of the light by reflection, recording the light An objective lens 260 for condensing the medium in a spot shape, a recording medium on which light is irradiated or reflected, a optical disk 270, and a sensor lens for condensing light reflected from the recording medium on a cell of a photodetector And a light detector 290 for detecting the light reflected from the recording medium and reproducing the signal recorded on the recording medium. In this case, the tracking light forming unit 220 includes a substrate and a diffraction grating pattern, and forms a tracking light by dividing a light source having a specific wavelength into two beams, a main beam and a sub beam.

On the other hand, the light source unit of the optical pickup unit may include a plurality of laser diodes for generating light of different wavelengths, and can record and play back all of the CD (CD), DVD (DVD), Blu-ray Disc (BD) As the optical pickup unit is provided, it is possible to use a CD, a DVD, and a Blu-ray Disc as one optical pickup unit.

On the other hand, the optical pickup unit may include a CD, DVD (CD / DVD) optical system module and a Blu-ray Disc (BD) optical system module. The optical module may be classified according to the laser diode included, and optical components such as mirrors may use the same or similar optical components described with reference to FIG. 2.

3 is a diagram illustrating an example of a configuration of an optical pickup unit.

Referring to FIG. 3, the optical pickup unit may generate an RF signal by reading data recorded on the optical disc. To this end, the optical pickup unit includes an objective lens 361 and a two-wavelength LD (2 wavelength laser diode (LD)) 311 and an objective lens for condensing the light emitted from the two-wavelength LD 311 in the form of spots on a recording medium. 311, a photo diode (PD) 391 for detecting the amount of light emitted from the optical disk and reflected from the optical disk, a tracking actuator (not shown) for tracking and focus servo, and a focus actuator (not shown). .

The two-wavelength LD 311 used in the present invention can selectively irradiate light of the first wavelength corresponding to the DVD layer and light of the second wavelength corresponding to the CD layer. The light of the first wavelength may be light for a DVD having a wavelength of about 650 nm, and the light of the second wavelength may be light for a CD having a wavelength of about 780 nm.

Further, the BD laser diode (LD) 312 for irradiating BD light having a wavelength of about 405 nm and the objective lens 362 and BD LD 312 for condensing the light irradiated from the BD LD 312 in the form of spots on a recording medium. A photodiode (PD) 392 for detecting the amount of light irradiated from the optical disk and reflected from the optical disk, and an actuator (not shown) for tracking and focus servo.

Further, data recorded on the optical disc can be read out in a corresponding reproduction mode according to the type of the determined optical disc. Therefore, if it is determined that the optical disc is a DVD, the two wavelength LD 311 can irradiate the DVD light, and if it is determined that the loaded optical disc is the CD, the two wavelength LD 311 can irradiate the CD light. Further, if it is determined that the optical disc is a BD, the BD LD 312 can irradiate the BD light.

On the other hand, the use of an objective lens to correspond to each type of optical disk or the use of an optical pickup unit to correspond to each type of optical disk has a problem of increasing the manufacturing cost and miniaturizing the optical disk device. .

4 is a diagram illustrating a configuration of an optical pickup unit according to an exemplary embodiment of the present invention, and FIGS. 5 to 8 are views for explaining an optical disc apparatus according to an exemplary embodiment of the present invention.

9 is a flowchart illustrating a method of operating an optical disk device according to an embodiment of the present invention, and FIGS. 10 and 11 are views referred to for explaining the method of operating an optical disk device according to an embodiment of the present invention.

Referring to FIG. 4, an optical pickup unit according to an exemplary embodiment of the present invention includes a light source unit 411 and 412 including a plurality of light sources, an objective lens 460 for condensing light emitted from the light source unit to an optical disc, and the optical disc. The light detector 490 may detect the reflected light.

The light source unit BD for irradiating the second wavelength LD 411 capable of selectively irradiating the light of the first wavelength corresponding to the DVD layer and the light of the second wavelength corresponding to the CD layer and the BD light of the third wavelength. It may include a laser diode (LD) 412.

Meanwhile, the optical pickup unit described with reference to FIG. 3 is configured using two optical paths of a CD / DVD and a Blu-ray BD using a two-wavelength object lens.

However, the optical pickup unit according to the embodiment of FIG. 4 may reduce manufacturing costs by using one three wavelength (BD, DVD, CD) objective lens 460. That is, the plurality of light having different wavelengths may be used. It may include an objective lens 460 commonly used.

In addition, according to the exemplary embodiment, the collimation lens 440 and the light detector 490 may also be configured as one to further reduce manufacturing cost.

On the other hand, in the case of such a three-wavelength one objective lens, since all wavelengths irradiated from three laser diodes LD pass through one objective lens OBL, signal interference between the wavelengths results in flare noise and the like. False signals may occur.

In addition, such signal interference and flare noise may cause problems in the disc recognition process algorithm.

FIG. 5A illustrates an example in which a CD (CD) having a distance from the optical disk surface to the data recording surface is about 1.1 mm, using a CD laser diode (LD). FIG. 5B shows data from the surface. The distance to the recording surface shows an example of reproducing a DVD (DVD) of about 0.6 mm with a DVD laser diode (LD).

Looking at the example of DVD / CD recognition, in order to play DVD / CD, the DVD / CD laser diode (LD) is turned on and then signaled. It is judged that the media has a characteristic close to that of the media.

In this case, since the light and the reflected light irradiated to the recording surface have one optical path, interference or misunderstanding problems may occur.

Accordingly, the present invention, while applying the structure of the three-wavelength 1 objective lens (OBL) to distinguish between the noise signal, such as flare and the actual signal to be taken, to provide a more accurate disk recognition method.

In the operating method according to the embodiment of the present invention, first, the plurality of light sources LD are turned on and irradiated with light to sequentially condense them onto the optical disc (S910). The photodetector 490 is reflected from the optical disc. Detects light (S920).

The light source unit may include a first light source for irradiating light of the first wavelength and a second wavelength and a second light source for irradiating light of the third wavelength.

For example, the light source unit includes a two-wavelength LD 411 and a third wavelength BD light capable of selectively irradiating light of a first wavelength corresponding to a DVD layer and light of a second wavelength corresponding to a CD layer. The irradiation may include a BD laser diode (LD) 412.

Meanwhile, the method may further include driving the actuator.

The position of the track on which information is recorded may vary relatively due to manufacturing errors and deformations, vibrations due to rotation, and errors in the optical pickup unit itself. Accordingly, in order to compensate for this, the objective lens may be driven by an electrical signal through an actuator. Actuator is generally composed of a coil and a magnet to move the objective lens by the current flowing through the coil and the electromagnetic force between the magnet.

The distance between the surface layer of the optical disk and the recording layer is used to determine whether the CD, DVD or BD is used. However, the flare noise may cause errors in the distance measurement and disc recognition algorithm.

When the focus actuator is physically raised toward the surface of the optical disc, the first wavelength reached for any optical disc is the wavelength output through the CD sphere. Next, the DVD and the BD with the largest curvature are detected last.

Referring to FIG. 6, a case in which light 611 corresponding to a BD wavelength of about 405 nm, light 612 corresponding to a DVD wavelength of about 660 nm, and light 613 corresponding to a CD wavelength of about 790 nm are irradiated will be described. The signal due to the light reflection is first generated on the surface of the CD 623 or the recording layer, and then the signals are generated in the order of the DVD 622 and the BD 621.

FIG. 7 illustrates an example of a signal detected by light reflected when the CD is irradiated with light 613 corresponding to a CD wavelength of about 790 nm.

In this case, a signal 710 due to light reflection occurs first on the surface or recording layer of the CD 623, and then a signal 720 affected by the DVD flare noise, and a signal 730 affected by the BD flare noise. May occur sequentially.

On the other hand, the controller 110 may determine the type of the optical disk based on the type of the light source irradiating the light to the optical disk and the order detected by the optical detector (S930) corresponding to the type of the optical disk determined The playback mode can be entered.

For example, by detecting a third signal when the light source is a BD LD, a second signal when the light source is a DVD LD, and a first signal when the light source is a CD LD, the type and flare of the optical disc are faster. Whether or not noise can be determined.

Alternatively, it is possible to determine the number of signals outputting a signal of a predetermined level or more, and to determine the type of the optical disc and whether flare noise is present.

Meanwhile, the method may further include determining a time corresponding to a distance from the surface of the optical disk to the data recording surface of the optical disk based on the detected light, wherein the determining step S930 may include the type of the light source; The type and the flare noise of the optical disc may be determined based on the detected order and the time.

As described above, the optical discs have different distances between the surface and the recording surface depending on the type. Therefore, the type of optical disc can be determined using the detection time of the reflected light signal on the surface of the optical disc and the reflected light signal on the recording surface.

In addition, when the Blu-ray Disc (BD) laser diode (LD) is turned ON using the above-described sequential rule, when the DVD LD is turned ON, and the CD LD is turned ON. Each surface layer can be distinguished.

If a Blu-ray Disc (BD) is inserted, the last one of the three detected signals is detected and defined as the surface layer signal, and the distance between the signals on the data recording surface that is generated is measured to determine the type of the disc and the flare noise. You can judge.

On the other hand, the objective lens according to the embodiment of the present invention may be formed in an aspherical shape.

Referring to FIG. 8, the objective lens includes a first arc region 810, a second arc region 820 formed adjacent to the first arc region, and the second arc region 820. It may include a third arc region 830 formed adjacent to the arc region.

Meanwhile, the first, second, and third arc regions 810, 820, and 830 may correspond to light having different wavelengths. For example, the first, second, and third arc regions 810, 820, and 830 may correspond to light having wavelengths corresponding to CD, DVD, and BD, respectively.

On the other hand, the operation method of the optical disk device according to an embodiment of the present invention further comprises the step of generating an RF signal in the RF processing unit 150 based on the detected light, the determination step (S930), the The type of the optical disc may be determined based on the type of the light source, the detected order, and the magnitude of the RF signal level.

That is, the type of the disc and the flare noise may be determined based on the RF level by outputting the RF signal rather than determining the type of the disc by the reflected optical signal itself.

Due to flare noise, a case may occur in which the focus is not focused on the data plane but focuses on the surface or the middle of the surface and the data plane. This is usually done by using the size of the focus error (FE) signal or the Srfo signal. The signals generated by the flare noise are also similar to the actual signal size, which may cause an error.

FIG. 10 illustrates an RF signal 1010, an FE signal 1020, and an SRFO signal 1030 in the case where focus is not accurately focused on due to flare noise, and FIG. 11 illustrates an RF signal at normal focus on. 1110, FE signal 1120, and SRFO signal 1130 are illustrated.

According to an exemplary embodiment of the present invention, if the RF level is measured at a corresponding position by focusing on and the reference level is higher than or equal to the reference level, the data plane is detected correctly, otherwise, the detection is caused by flare. You can judge.

In addition, it is possible to determine whether the flare (flare) by using the FE signal and the SRFO signal.

An astigmatism based focus error (FE) detection method is described as an example.

The photodetector has a main beam photodetection cell for receiving zero-order light from the return light and a subbeam photodetection cell for receiving primary light from the return light on the light-receiving surface. The cells are formed in a divided pattern in which the light receiving surface for receiving the return light is formed in a substantially rectangular shape, and each light receiving region divided into four sections by a set of orthogonal dividing lines through the center of the light receiving surface. The sub-beam photodetection cells may be formed at positions opposite to each other with the main beam photodetection cells interposed therebetween.

If the objective lens is in an optimal position with respect to the recording / reproducing surface of the recording medium and is in a just focus state coinciding with the recording / reproducing surface of the recording medium, The shape of the beam spot is circular. If the objective lens is too close to the recording / reproducing surface of the recording medium, or is too far away from the recording medium, the beam spot has an elliptical shape due to astigmatism of the returned light. Therefore, the focus error can be obtained by comparing the received light output of the returned light by each light receiving area with each other.

Such a focus error signal is different from a signal during an abnormal focusing operation and a signal during a normal focusing operation as shown in FIGS. 10 and 11. Therefore, it is possible to detect whether there is noise according to the distortion degree of the focus error signal and the comparison with the reference value.

In addition, the SRFO value obtained by adding the outputs of the four equally divided light receiving regions can also be used for noise detection according to comparison with the reference value similarly to the FE signal.

The optical disk device and its operation method according to the present invention are not limited to the configuration and method of the embodiments described as described above, but the embodiments may be all or part of each embodiment so that various modifications can be made. It may alternatively be configured in combination.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.

Claims (14)

An optical pickup unit including a light source unit including a plurality of light sources, an objective lens for condensing the light emitted from the light source unit to an optical disc, and a light detector configured to detect light reflected from the optical disc; And
Determining the type of the optical disc based on the type of light source irradiating the light onto the optical disc and the order detected by the light detecting unit, and controlling to reproduce the data recorded on the optical disc in a reproduction mode corresponding to the type of the optical disc. And a control unit. The method of claim 1,
The light source unit includes a first light source for irradiating light of the first wavelength and the second wavelength and a second light source for irradiating light of the third wavelength. The method of claim 1,
And the objective lens is formed in an aspheric shape. The method of claim 3,
The objective lens has a first arc region, a second arc region formed adjacent to the first arc region, and a third arc region formed adjacent to the second arc region. Includes an arc region,
And the first, second, and third arc regions correspond to light having different wavelengths, respectively. The method of claim 1,
And an RF processor configured to generate an RF signal based on the detected light. The method of claim 5,
And the controller determines the type of the optical disc based on the type of the light source, the detected order, and the magnitude of the RF signal level. The method of claim 1,
And the control unit determines the time corresponding to the distance from the surface of the optical disc to the data recording surface of the optical disc based on the detected light. The method of claim 7, wherein
And the controller determines the type of the optical disc based on the type of the light source, the detected order, and the time. Sequentially condensing the light emitted from the plurality of light sources with the optical disc;
Detecting light reflected from the optical disk; And
And determining the type of the optical disc based on the type of the light source irradiating light onto the optical disc and the order detected by the light detector. 10. The method of claim 9,
And entering a reproducing mode corresponding to the determined type of optical disc. 10. The method of claim 9,
The plurality of light sources include a first light source for irradiating light of the first wavelength and the second wavelength and a second light source for irradiating light of the third wavelength. 10. The method of claim 9,
Generating an RF signal based on the detected light;
And the determining step determines the type of the optical disc based on the type of the light source, the detected order, and the magnitude of the RF signal level. The method of claim 1,
And determining a time corresponding to a distance from a surface of the optical disk to a data recording surface of the optical disk based on the detected light. The method of claim 13,
And wherein said determining step determines the type of said optical disc based on said type of said light source, said detected order and said time.

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