KR20130032094A

KR20130032094A - Optical disk device and method for operating thereof

Info

Publication number: KR20130032094A
Application number: KR1020110095792A
Authority: KR
Inventors: 최준우
Original assignee: 엘지전자 주식회사
Priority date: 2011-09-22
Filing date: 2011-09-22
Publication date: 2013-04-01

Abstract

An operating method of an optical disk device according to an embodiment of the present invention comprises the steps of rotating the optical disk, turning on the first light source, detecting the focus error signal and the RF signal, detected focus error signal and RF signal Determining the type of the optical disc by comparing the respective reference values, entering a reproduction mode corresponding to the determined type of the optical disc, and reproducing data recorded on the optical disc with the first light source.
An optical disk apparatus according to an embodiment of the present invention includes a motor for rotating an optical disk, an optical pickup unit including a light source unit including a first light source, and a light detector for detecting light reflected from the optical disk, and a focus error based on the detected light. RF processing section for generating signals and RF signals, memory storing reference values and focus error signals and RF signals are compared with reference values to determine the type of optical disc, enters the playback mode corresponding to the type of optical disc, and writes to the optical disc And a control unit for controlling the reproduced data to be reproduced using the first light source.

Description

Optical disk device and method for operating thereof

The present invention relates to an optical disc apparatus and an operation method thereof, and more particularly, to an optical disc apparatus and an operation method thereof capable of reducing a material cost and simplifying a reproduction algorithm.

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.

An object of the present invention is to provide an optical disk apparatus and a method of operating the same, which can reduce the material cost and simplify the playback algorithm.

An operating method of an optical disk device according to an embodiment of the present invention comprises the steps of rotating the optical disk, turning on the first light source, detecting the focus error signal and the RF signal, detected focus error signal and RF signal Determining the type of the optical disc by comparing the respective reference values, entering a reproduction mode corresponding to the determined type of the optical disc, and reproducing data recorded on the optical disc with the first light source.

An optical disk apparatus according to an embodiment of the present invention includes an optical pickup unit including a motor for rotationally driving an optical disk, a light source unit including a first light source, and a light detector for detecting light reflected from the optical disk, and a focus error based on the detected light. RF processing section for generating signals and RF signals, memory storing reference values and focus error signals and RF signals are compared with reference values to determine the type of optical disc, enters the playback mode corresponding to the type of optical disc, and writes to the optical disc And a control unit for controlling the reproduced data to be reproduced using the first light source.

The optical disc apparatus and its operation method according to the present invention can reduce the material cost and reproduce the data recorded on the optical disc with a simplified algorithm.

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 flowchart according to an example of a method of operating an optical disk device.
FIG. 4 is a diagram referred to for describing the operating method of FIG. 3.
5 is a flowchart of a method of operating an optical disk device according to an embodiment of the present invention.
6 to 9 are views for explaining an operating method of the optical disk device according to an 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 The objective lens 260 for condensing the medium in the form of spots, the recording medium 270 for irradiating or reflecting the light irradiated, and the sensor lens for condensing the light reflected from the recording medium in the form of spots in the cells of the 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 according to an embodiment of the present invention may include a DVD optical 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 flowchart illustrating an example of an operating method of an optical disc device, and FIG. 4 is a diagram referred to for describing the operating method of FIG. 3.

When the optical disk is inserted into the optical disk device and driven to rotate (S310), the Blu-ray Disc BD laser diode LD is turned on (S320).

It is judged whether the inserted optical disc is a Blu-ray Disc (BD), and when the type of the optical disc is a Blu-ray Disc (BD), the Blu-ray Disc (BD) laser diode depends on the operating characteristics of the Blu-ray Disc playback mode. The data recorded on the optical disc is reproduced using the LD (S333).

On the other hand, when the optical disk is not the Blu-ray Disc BD, the DVD laser diode LD is turned on (S340) and the focus error signal and the RF signal level are detected (S350).

Thereafter, the CD laser diode LD is turned on (S360) to detect the focus error signal and the RF signal level (S370).

On the basis of the focus error signal and the RF signal level detected two times (S350 and S370), it is determined whether the type of the inserted optical disc is a DVD or a CD (S380).

The data recorded on the optical disc is reproduced in accordance with the operation characteristics of each reproduction mode on the basis of the type of the optical disc determined (S383, S385).

FIG. 4A shows an example of reproducing a CD (CD) having a distance from the disk surface to the data recording surface with a CD laser diode LD. FIG. 4B 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).

In this case, since a laser diode (LD) suitable for each media is used, both a Blu-ray Disc (BD) laser diode (LD) and a DVD (CD) / CD (CD) laser diode (LD) are required. There is therefore a further need for components of the optics module.

In addition, in order to play DVD / CD, the DVD / CD laser diode LD is turned on to judge the magnitude of the signal, which has characteristics close to that of the media. Judging, the DVD or CD goes through a number of steps for playback.

Accordingly, an aspect of the present invention is to provide an optical disk device and a method of operating the same, which can reduce a material cost and simplify a reproduction algorithm.

5 is a flowchart illustrating a method of operating an optical disk device according to an embodiment of the present invention, and FIGS. 6 to 9 are views for explaining an operating method of the optical disk device according to an embodiment of the present invention.

Referring to FIG. 5, when the optical disk in which the motor is inserted is rotated in operation (S510), the first light source of the optical pickup unit is turned on (S520).

The first light source may be a laser diode (LD) for a DVD.

Meanwhile, the light detector of the optical pickup unit detects light reflected from the optical disk, and the RF processor generates a focus error signal, an RF signal, etc. based on the detected light (S530).

In order to reproduce data on the recording medium or record data on the recording medium in the optical pickup unit, accurate focus and tracking control must be performed based on the stable optical system structure.

To this end, the photodetector receives the laser light reflected from the recording medium and converts the laser light into an electrical signal, and performs focus and tracking control using the laser light received from the photodetector.

For focus and tracking control, a focusing error and a tracking error are detected by various methods. In general, a focus error (FE) is detected by astigmatism for focus control, and for tracking control. Tracking errors (TE) can be detected by the DPP (Differential Push Pull) method or the 3-spot method.

First, a focus error detection method based on astigmatism will be described.

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, when the light reception output of the return light by each light reception area is compared with each other, a focus error can be obtained.

On the other hand, in the case of the DPP method, a tracking error is obtained by using a difference signal between a spot caused by a main beam and a spot caused by a sub beam, and the photodetector unit receives a spot and a sub beam caused by a main beam received in each light receiving region of each cell. The tracking error can be obtained by obtaining the difference of the spot signals by.

The controller determines the type of the optical disc by comparing the detected focus error signal and the RF signal with respective reference values stored in the memory.

The control unit may determine the optical disc as a CD when the focus error signal and the RF signal are smaller than the reference value.

The controller may determine the optical disc as a DVD when the focus error signal and the RF signal are greater than or equal to the reference value.

That is, when the focus error signal FE is smaller than the focus error reference value V1 and the RF signal level is smaller than the RF signal reference value V2, the inserted optical disc may be determined as a CD series.

Meanwhile, the focus error reference value V1 and the RF signal reference value V2 may be determined by an experiment result. For example, a DVD-ROM may have a focus error level of 18V and an RF signal level of 800mV, and a CD-ROM may have a focus error level of 3.5V and an RF signal level of 400mV. In this case, the focus error reference value V1 may be 5V, and the RF signal reference value V2 may be 500mV.

Thereafter, the controller controls to enter the playback mode which is driven by the operation characteristic corresponding to the determined type of the optical disk (S550, S560).

For example, when the optical disc is a CD, a first play mode S550 may be entered. When the optical disc is a DVD, a second play mode S560 may be entered.

On the other hand, the control unit may control to reproduce the data recorded on the optical disk using the first light source. That is, according to the present invention, not only two light sources for CD and DVD can be used, but both CD and DVD can be reproduced with different operating characteristics with only one light source.

The controller and the servo unit may perform a servo operation to be suitable for each reproduction mode.

As described with reference to FIG. 3, in the case of a Blu-ray Disc (BD) player, a BD / DVD / CD disc may be played using BD / DVD / CD LD (Laser Diode), respectively.

This uses a laser diode (LD) having a unique wavelength for each disk, and uses approximately BD (405 nm), DVD (650 nm), and CD (780 nm) laser diodes.

However, DVDs and CDs have a similar wavelength range, which allows DVD laser diodes (LDs) to play some media on CD discs as well as DVD discs.

Therefore, in one embodiment of the present invention, after determining whether the optical disc is a CD or a DVD, the playback mode is set to the CD mode or the DVD mode according to the determination result, and the wavelength ranges of the DVD and the CD are 650 nm and 780 nm, respectively. 6, only the DVD laser diode LD can be used to play a DVD / CD in consideration of similar characteristics.

Accordingly, the CD laser diode LD is not required for CD reproduction, and the DVD laser diode LD is used to replace the function of the CD laser diode LD. This can eliminate the CD laser diode (LD).

In addition, in the case of the CD, when the signal size is smaller than the DVD at the time of recognition, the algorithm can be simplified by judging by the CD when the signal size is smaller than the specified reference value. As a result, the optical disc type discrimination time can be shortened.

As described above, the RF processor may generate the focus error signal FE by calculating the light received from the quadrant photodetector by astigmatism.

In addition, the DC signal generated by summing the light input from the four equally divided photodetector may be output to the servo unit together with the focus error signal FE.

The astigmatism method described above will be described in more detail with reference to FIGS. 7 to 9.

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 becomes circular, as shown in FIG.

When the objective lens is too close to the recording / reproducing surface of the recording medium or is too far away, and when it is out of the just focus state, the shape of the beam spot due to astigmatism of the return light is shown in FIGS. 8A and 8B, respectively. Oval.

FIG. 9 is a diagram illustrating a focus error signal FE generated according to the shape of light as shown in FIGS. 7 and 8.

More specifically, FIG. 9A shows regions A and C of the quadrant photodetector, FIG. 9B shows regions B and D of the quadrant photodetector, and FIG. 9C shows a focus error. It is a figure which shows a signal.

When the light passing through the objective lens approaches the data layer, the light focused on the quadrant divided photodetector is mainly focused in the A and C areas, and the value of A + C at the point P1 has a maximum value, and B + The value of D has a minimum value. Accordingly, the focus error signal FE has a maximum value.

On the other hand, in the case where the light transmitted through the objective lens is in the just focus state in which the data layer is accurately formed in the data layer, the light focused on the four-divided photodetector becomes uniform, and the focus error signal FE at the P2 point becomes zero.

On the other hand, when the light passing through the objective lens is far from the data layer, the light focused on the quadrant divided photodetector is mainly focused on the B and D regions. Therefore, at the point P3, the value of A + C has a minimum value, the value of B + D has a maximum value, and the focus error signal FE has a minimum value.

The light input from the four equally divided photodetectors is calculated by the astigmatism method to generate the focus error signal FE and compare the reference values to determine the type of optical disc.

Further, after determining whether the type of optical disc is CD or DVD, the detailed type can also be determined using the fact that the ROM / R / RW has different reflectances. That is, the detailed type of the optical disk can also be determined using the difference in the signal magnitude detected by being irradiated with laser light on the optical disk.

On the other hand, the operation method of the optical disk device according to an embodiment of the present invention, the step of turning on (2) the second light source corresponding to the wavelength different from the first light source and when the optical disk is an optical disk corresponding to the second light source The method may further include reproducing the optical disc with the second light source. In this case, the second light source may be a laser diode for a Blu-ray disc BD.

That is, before the steps described with reference to FIG. 5, in the case of a Blu-ray disc having a different wavelength range, a search and play operation of the Blu-ray disc may be performed first.

The optical disc apparatus and its operation method according to the present invention can reduce the material cost and reproduce the data recorded on the optical disc with a simplified algorithm. In addition, the time required for determining the type of optical disc can be shortened.

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

Rotating the optical disc;
Turning on the first light source;
Detecting a focus error signal and an RF signal;
Determining the type of the optical disc by comparing the detected focus error signal and the RF signal with respective reference values;
Entering a playback mode corresponding to the determined type of optical disc; And
And reproducing the data recorded on the optical disc with the first light source.

The method of claim 1,
And the first light source is a laser diode for DVD.

The method of claim 1,
And wherein the determining step discriminates the optical disc from a CD when the focus error signal and the RF signal are smaller than the reference value.

The method of claim 1,
And wherein the determining step discriminates the optical disc from a DVD when the focus error signal and the RF signal are greater than or equal to the reference value.

The method of claim 1,
The focus error reference value is 5V and the RF signal reference value is 500mV among the respective reference values.

The method of claim 1,
Turning on a second light source corresponding to a wavelength different from the first light source; And
And reproducing the optical disc with the second light source, when the optical disc is an optical disc corresponding to the second light source.

The method according to claim 6,
And the second light source is a laser diode for a Blu-ray Disc (BD).

A motor for rotating the optical disc;
An optical pickup unit including a light source unit including a first light source and a light detector configured to detect light reflected from the optical disc;
An RF processor configured to generate a focus error signal and an RF signal based on the detected light;
A memory storing a reference value; And
The type of the optical disc is determined by comparing the focus error signal and the RF signal with the reference value, and enters a reproduction mode corresponding to the type of the optical disc to reproduce data recorded on the optical disc using the first light source. And a control unit for controlling the optical disk device.

9. The method of claim 8,
And the first light source is a laser diode for DVD.

9. The method of claim 8,
And the control unit determines the optical disc as a CD when the focus error signal and the RF signal are smaller than the reference value.

9. The method of claim 8,
And the controller determines the optical disc as a DVD when the focus error signal and the RF signal are greater than or equal to the reference value.

9. The method of claim 8,
The focus error reference value is 5V and the RF signal reference value is 500mV among the respective reference values.

9. The method of claim 8,
The light source unit further includes a second light source corresponding to a wavelength different from that of the first light source,
And the control unit controls to reproduce the optical disc with the second light source when the optical disc is an optical disc corresponding to the second light source.

The method of claim 13,
The second light source is an optical disk device, characterized in that the laser diode for the BD (BD).