WO2014175632A1

WO2014175632A1 - Information storage medium, information storage medium reproducing apparatus, and information storage medium reproducing method

Info

Publication number: WO2014175632A1
Application number: PCT/KR2014/003498
Authority: WO
Inventors: 김재현
Original assignee: 삼성전자 주식회사
Priority date: 2013-04-24
Filing date: 2014-04-22
Publication date: 2014-10-30

Abstract

An information storage medium is disclosed. The information storage medium according to an embodiment of the present invention comprises a first disc layer, and a second disc layer stacked on the first disc layer, wherein the first disc layer and the second disc layer have different light reflectivities.

Description

Information storage medium and information storage medium reproducing apparatus and information storage medium reproducing method

The present invention relates to an information storage medium, and more particularly, to an information storage medium, an information storage medium reproducing apparatus, and an information storage medium reproducing method capable of accurately determining a layer in an information storage medium having at least one disc layer.

Generally, an optical information storage medium, for example, an optical disc, is widely used as an information storage medium of an optical pickup device for recording / reproducing information in a non-contact manner. Mainly, the information recording capacity is divided into compact discs, digital versatile discs and Blu-ray discs using blue laser light. The definition of high definition (HD) TVs from standard definition (SD) TVs to high definition (HD) TVs has been increasing, and the capacity of optical discs for video information is DVD-ROM, DVD-RAM, DVDR / RW, DVD + R / RW. It has a capacity of 4.7GB for single layer, 8.5GB for two layers, and BD-ROM / R / RE is developed for 25GB for single layer, 50GB for two layers, and BD-R for three layers. 100GB, 4 layers, 128GB, and BD-RE are available in 3 layers, 100GB capacity, and the 3D disk has a recording density of 33.3GB per layer and a 4GB disk with 32GB. It is realized.

On the other hand, the next-generation video contents are required to be developed for display devices and cameras corresponding to 4Kｘ2K, which have four times the resolution of HDTV, because the needs of video contents with high resolution and video display devices are increasing by responding to the large screen of the display apparatus. This is going on. These 4K images are also called Ultra High Definition (UHD) along with Super High Vision. In addition, video coding technologies such as MPEG2 and AVC / H264, which are used as Blu-ray discs, are also being developed as high efficiency video coding (HEVC) standards as next-generation technologies corresponding to UHD.

The amount of information of 4Kx2K video is four times that of Full HD. If the conventional video coding techniques such as MEPG2 and AVC / H264 are applied to 4K content, four times the recording capacity of Full HD is required.

Therefore, when HEVC, which is a next-generation video encoding technology, is applied, the compression efficiency is expected to be about twice that of AVC / H264, so that the amount of information can be compressed up to twice that of Full HD. In other words, the BD-ROM that records the current Full HD movie contents can record about 3 hours of video at 50GB, but it requires twice the capacity of 100GB when recording 4Kx2K video using HEVC.

Since Blu-ray discs for recording already have capacities of 100 GB of BD-R / RE 3 layers and 128 GB of 4 BD-R layers, recording of HEVC-encoded video at 100 GB for about 3.2 hours and 128 GB for about 4.1 hours. However, since the BD-ROM exists only up to 50GB on the second floor, only about 1.6 hours of video can be recorded. In particular, most of the contents recorded on the ROM disc are movies, and movie recording time averages about 2 hours and nearly 3 hours. In the case of 3D compatible discs, the capacity is about 1.7 times that of 2D. There is a way to split a movie title into two 50GB discs, but the user will have to change the disc, and because the content is relayed, it will hinder the immersion of the movie through the same high-quality video as in the theater. If possible, it is preferable to use one sheet. In order to record on one disc, a large capacity of the BD-ROM, that is, a ROM disc capacity of 100 GB or more is required. In this case, by constructing a BD-ROM with recording densities such as BD-R / RE 100GB and BD-R 128GB, since the optical structure of the existing playback apparatus hardly changes, the basic design of the apparatus can be configured in almost the same form. have.

When an information storage medium is mounted in the information storage medium reproducing apparatus, a disc discrimination operation is first performed. In this process, the collimator lens is adjusted to an appropriate position and the objective lens is moved up and down to analyze the focusing error signal output at this time to distinguish CD, DVD and BD. Then, the number of signals is checked to discriminate single layer and multiple layers.

However, as the recording layer is formed in multiple layers in order to further increase the recording capacity as described above, the difference in the thickness of the interlayer increases, so that the range of the collimator lens to be compensated for is increased and the difference between the servo signals in the state where the collimator lens is fixed. It has also grown very large. Therefore, a problem arises in that the signal cannot be properly detected during the disc discrimination operation or the interlayer movement. In the prior art, there is no way to compensate for this signal difference, which is a problem.

First of all, when the disc discrimination operation is performed at the same collimator lens position as the disc discrimination, the L2 signal is hardly output in the case of the 3-layer disc. In this case, a BD triple layer (TL) is mistaken for a double layer (DL), and a proper lead-in operation cannot be performed.

In addition, due to the aberration caused by the disc thickness difference during the layer jump, a difference occurs in the focusing error signal in each layer depending on which layer the collimator lens is located close to. Conventionally, the collimator lens is placed in the center or moved to the target layer, thereby obtaining a focusing error (FE) signal.

However, in the conventional method, the L2 focusing error signal is generated at the L0 reference collimator lens position because the thickness difference between L0 and L2 is large when layer jumping between different layers (for example, from L0 to L2). There is a problem that you cannot perform layer jump because it hardly comes out. On the other hand, when the collimator lens is moved to the L2 reference collimator lens position, the focusing error signal of L0 becomes too small to maintain the focus servo and cause a focus drop. In the collimator lens in the intermediate position, a problem occurs in both the L0 and L2 signals, which causes a problem in that a normal layer jump cannot be performed.

Accordingly, there is a need for an information storage medium technology capable of accurately determining the number of disk layers by accurately detecting a focusing error signal for each layer at the disc determination.

In addition, an information storage medium technology that accurately detects a focusing error signal for each layer even when a layer jump is possible is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an information storage medium and an information storage medium reproducing apparatus capable of accurately determining the number of disc layers by accurately detecting a focusing error signal for each layer during disc determination. To provide.

Another object of the present invention is to provide an information storage medium and an information storage medium reproducing apparatus capable of accurately jumping a layer by accurately detecting a focusing error signal for each layer even during a layer jump.

An information storage medium according to an embodiment of the present invention for achieving the above object, in the information storage medium, includes a first disk layer and a second disk layer stacked on the first disk layer, The first disk layer and the second disk layer have different light reflectances.

In this case, the light reflectance of the first disk layer may be higher than the reflectance of the second disk layer.

The information storage medium may further include a third disk layer stacked on the second disk layer.

In addition, when a collimator lens of an information storage medium reproducing apparatus is moved to create an optimized focus between the second disk layer and the third disk layer, the first disk layer may have a maximum light reflectance. have.

According to an aspect of the present invention, there is provided an information storage medium reproducing apparatus, comprising: a laser driver for emitting laser light, and moving the emitted laser light to a predetermined position; A collimator lens for generating parallel light from the light source, an objective lens for injecting the parallel light into an information storage medium, a photodetector for detecting an intensity of reflected light from the information storage medium and generating an electrical signal, and focusing from the electrical signal. And a control unit for detecting an error signal, wherein the multiple layers of the information storage medium have different light reflectances.

In this case, when the information storage medium has three or more disk layers, the collimator lens may signal between the first disk layer, which is the highest layer of the information storage medium, and the second disk layer, which is the next layer of the first disk layer. Can be moved to optimize properties

In addition, the information storage medium may have three or more disk layers.

In addition, when the information storage medium has three or more disk layers, the light reflectance of the lowest disk layer of the information storage medium may be maximum.

According to various embodiments of the present disclosure as described above, the present invention provides an apparatus for reproducing an information storage medium and an information storage medium capable of accurately determining a disc type and a number of layers by accurately detecting a focusing error signal for each layer during disc determination. And a method for reproducing the information storage medium.

The present invention also provides an information storage medium, an information storage medium reproducing apparatus, and a method of reproducing an information storage medium capable of accurately detecting a focusing error signal for each layer even during a layer jump.

1 is a block diagram showing the configuration of an information storage medium reproducing apparatus according to an embodiment of the present invention;

2 illustrates a focusing error signal waveform of a three-layered information storage medium;

3 is a diagram illustrating an example of a thickness between layers in a three-layered information storage medium;

4 is a diagram illustrating an example of a thickness between layers in the case of a 4-layer information storage medium;

5 is a diagram illustrating a focusing error signal waveform of a three-layered information storage medium when the collimator lens is set to optimize focus in the two-layered information storage medium;

6 is a view showing an embodiment of an information storage medium having a layer with a different reflectance according to an embodiment of the present invention;

7 shows a focusing error signal waveform of an information storage medium having layers having different light reflectances;

8 illustrates regions of a recording layer (disc layer) of a Blu-ray disc according to an embodiment of the present invention;

9 is a view showing a layer structure of a Blu-ray disc according to an embodiment of the present invention, and

10 is a diagram illustrating an embodiment of laser regeneration power values.

Hereinafter, various embodiments of the present disclosure will be described with reference to the accompanying drawings.

1 is a block diagram showing the configuration of an information storage medium reproducing apparatus 200 according to an embodiment of the present invention.

An information storage medium reproducing apparatus 200 according to various embodiments of the present disclosure may include a compact disc (CD) reproducing apparatus, a digital versatile disc (DVD) reproducing apparatus, and a BD (blu-ray disc) reproducing apparatus. It includes. The information storage medium 100 may be an optical disc as an information storage medium of an optical pickup apparatus for recording / reproducing information in a non-contact manner. The optical disc includes the above-mentioned CD, DVD, and DVD.

Referring to FIG. 1, an apparatus 200 for reproducing an information storage medium according to an exemplary embodiment may include an optical pickup unit 210, an objective lens 240, an actuator 220, and a collimator lens 230. ), A motor 260, a laser driver 250, a light detector 270, a controller 280, and a signal processor 290.

When the information storage medium 100 is mounted, a rotating shaft (not shown) of the information storage medium reproducing apparatus 200 fixes and rotates the information storage medium 100. The controller 280 drives the laser driver 250, and the laser driver 250 supplies a current to a laser diode (not shown) to emit laser light. The emitted laser light passes through a beam splitter (not shown) and a polarizing beam splitter (not shown) and is incident on a collimator lens (CL) 230. The collimator lens 230 converts the laser light into parallel light, and the laser light is reflected by a reflecting mirror (not shown) to be incident on the objective lens 240 to be focused on the information storage medium 100. The laser light reflected by the information storage medium 100 according to a constant reflectance is reflected by a reflecting mirror (not shown), becomes converged light by the collimator lens 230, and is collected by the photodetector 270. The photo detector 270 detects the intensity of the reflected light to generate an electrical signal, and is sent to the signal processor 290 by the controller 280. The signal processor 290 performs necessary signal processing such as amplification or equalization on the received electric signal. The signal processor 290 generates a servo control signal, in particular, a focusing error signal (FE), and provides feedback to the controller 280.

The controller 280 controls the sled motor (not shown) to move the optical pickup 210 in the horizontal direction to access the data area of the information storage medium 100. The controller 280 controls the motor 260 to perform a focus swing operation in the vertical direction.

In the control unit 280, the information storage medium 100 is a CD (CD), DVD (DVD), DVD (BD) based on the focusing error (FE) signal detected through the focus swing operation as described above An information storage medium discriminating operation for determining which one is any one of them is performed.

For example, the first recording layer of the CD, the first recording layer of the DVD, and the first recording layer of the BD are formed at a distance of 1200 um, 600 um, and 100 um from the surface layer, respectively. The first sine wave signal corresponds to the surface layer and the second sine wave signal corresponds to the recording layer among the focusing error (FE) signals detected through the focus swing operation. If the detection interval between the second sine wave signals is relatively small, it can be determined as BD, usually DVD, and CD.

On the other hand, when performing the type discrimination operation of the information storage medium in the data area as described above, a low level laser reproduction power (e.g., 0.3 mW) is used to safely prevent the recording layer from being damaged. If the information storage medium 100 inserted in the information storage medium reproducing apparatus 200 is determined to be a BD through the above operation, the controller 280 may determine that the optical pickup 210 controls the optical pickup 210 of the video BD. Control access to Burst Cutting Area (BCA) area.

2 is a diagram illustrating a focusing error signal waveform of a three layer information storage medium, FIG. 3 is a diagram illustrating an example of an interlayer thickness in the case of a three layer information storage medium, and FIG. 4 is a case of a four layer information storage medium. FIG. 1 shows an example of the thickness between layers.

The controller 280 controls the motor 260 to perform a focus swing operation in the BCCA area. When the information storage medium 200 is a 3-layer BD-3 layer, as illustrated in FIG. 2, a first sine wave signal of the focusing error signal corresponds to a surface layer, and a second sine wave signal is represented by a second layer. The third recording layer L2, the third sine wave signal corresponds to the second recording layer L1, and the fourth sine wave signal corresponds to the first recording layer L0.

However, when the recording layer is formed into multiple layers in this manner, the thickness difference between the recording layers becomes large as shown in Figs. Accordingly, the range of the collimator lens 230 to be compensated for is increased, and the difference between the servo signals in the state in which the collimator lens 230 is fixed is also greatly increased. Therefore, a problem arises in that the signal cannot be properly detected during the information storage medium discrimination operation or during the inter-layer movement (layer jump).

FIG. 5 is a diagram illustrating a focusing error signal waveform of a three-layer video BD when the collimator lens is set to optimize focus in a two-layered information storage medium.

The collimator lens 230 causes a difference in the focusing error signal in each layer depending on which layer it is located close to. A conventionally used setting in the two-layer information storage medium is to set the collimator lens so that focusing is optimized between the L0 layer and the L1 layer.

In this case, the information storage medium 100 having three or more layers has a problem in that the size of the focusing error signal for the third recording layer L2 is very small due to the layer spacing. In this case, the three-layer information storage medium 100 is mistaken as a two-layer information storage medium, so that a proper lead-in operation cannot be performed.

A similar situation occurs with layer jumps. Due to the aberration caused by the thickness difference of the information storage medium 100 during the layer jump, a difference occurs in the focusing error signal in each layer depending on which layer the collimator lens 230 is located close to. In the past, the collimator lens 230 was placed in the center or moved to a target layer, thereby securing a focusing error (FE) signal.

However, in the conventional method, the L2 focusing error signal is generated at the L0 reference collimator lens position because the thickness difference between L0 and L2 is large when layer jumping between different layers (for example, from L0 to L2). There is a problem that you cannot perform layer jump because it hardly comes out. In addition, when the collimator lens 230 is moved to the L2 reference collimator lens 230 position, the focus error signal of L0 becomes too small to maintain the focus servo and cause a focus drop. In the collimator lens 230 in the intermediate position, a problem occurs in both the L0 and L2 signals, thereby preventing a normal layer jump.

According to one embodiment of the present invention, this problem can be solved by making the light reflectance between the plurality of layers differently. That is, the collimator lens 230 may be placed at a preset position, and the information storage medium 100 having a different amount of light reflection of each layer may be reproduced. For example, when the collimator lens 230 is positioned optimally between L0 and L1 in the three-layered information storage medium 100, since the size of the focusing error signal of L2 will be small, the light reflectance of L2 is relatively low. It is necessary to use a large information storage medium 100. On the other hand, when the collimator lens 230 is positioned optimally between L1 and L2 in the three-layered information storage medium 100, since the size of the focusing error signal of L0 will be small, information having a relatively large optical reflectance of L0 is obtained. The storage medium 100 is used.

When L2 and L3 are far from the reference position of the collimator 230 in the four-layer information storage medium 100, the reflection amounts of L2 and L3 may be manufactured differently from other layers. When the reflectance is large, the servo signal is also increased, so that accurate information storage medium 100 can be accurately identified.

6 is a diagram illustrating an embodiment of an information storage medium having layers having different reflectances, according to an exemplary embodiment.

Referring to FIG. 6, when the reflection amount of each layer is 6 to 12%, the signal at L2 is too small, so that the reflection amount of L2 may be about 10 to 16%.

7 is a diagram illustrating a focusing error signal waveform of an information storage medium having layers having different light reflectances.

As illustrated in FIG. 7, the information storage medium 100 having layers having different light reflectances can detect a focusing error signal that can be discriminated in all layers. That is, in the three-layered information storage medium, the focusing error signal size is less than or equal to the reference level, so that the undetermined L2 signal becomes larger than the reference level, so that determination is possible, and all three layers can be accurately determined.

The information storage medium 100 has a disk substrate formed of a transparent synthetic resin material such as a transparent polycarbonate resin, a polyvinyl chloride resin, an acrylic resin and the like having high light transmittance and mechanical resistance or chemical resistance. In each layer of the information storage medium 100 having a multi-layer, aluminum or the like having high light reflectance is deposited so that signal recording is performed and a protective layer is entirely coated. Each layer becomes a translucent film and is formed to reflect a certain ratio of laser light.

On the other hand, since the BCA code recorded in the form of a barcode in the first recording layer L0 is detected as a BCA cutting signal of a high frequency component, the low pass filter LPF (not shown) in the signal processor 290 (not shown). By eliminating the high frequency components included in the BCA cutting signal, the number of recording layers can be accurately counted by appropriately setting a threshold level for slicing a focusing error signal. .

The controller 280 reads the BCA code to finally accurately determine the type of the information storage medium 100, and then allows the optical pickup 210 to access the data area. And the laser reproduction power suitable for the type of recording layer and the recording layer.

Hereinafter, a structure of the information storage medium 100 according to various embodiments of the present disclosure will be described.

8 is a diagram illustrating regions of a recording layer (disc layer) of a Blu-ray disc according to an embodiment of the present invention.

In general, various types of optical discs such as CD, CD, DVD, etc. are widely used. The video BD is divided into a video single layer, a video dual layer, a video multi layer, and the like according to the number of data recording layers.

As shown in FIG. 8, the BD BD includes a burst cutting area (BCA) area, a lead-in area, a data area, and a lead-out area. This division is allocated, and a BCA code in the form of a bar code is recorded in the BCA area.

9 is a diagram illustrating a layer structure of a Blu-ray disc according to an embodiment of the present invention.

In the case of the BD, as illustrated in FIG. 9, the first recording layer L0 of the BD-Single Layer is formed at a position 100um away from the surface layer, and the video double The first recording layer L0 of the layer BD-Dual Layer may be formed at a position 100um apart from the surface layer, and the second recording layer L1 may be formed at a position 75um apart from the surface layer.

In addition, the first recording layer L0 of the BD triple layer is formed at a position 100um apart from the surface layer, and the second recording layer L1 and the third recording layer L2 are formed on the surface thereof. It can be formed at positions 75um and 57um, respectively, from the layer.

The first recording layer L0 of the BD-4 layer is formed at a position 100um apart from the surface layer, and includes the second recording layer L1, the third recording layer L2, and the first recording layer L0. The four recording layers L3 may be formed at positions spaced apart from the surface layer by 84.5 um, 65.0 um, and 53.5 um, respectively.

In the optical disc drive (ODD) that reads and reproduces data recorded in the recording layer of the BD BD as described above, the laser read power is appropriately adjusted according to the type of the video and the recording layer.

10 is a diagram illustrating an embodiment of laser regeneration power values.

As shown in FIG. 10, the laser reproduction power suitable for the first recording layer L0 of the once-recordable video single layer R-SL is 0.35 mW, and the once-recordable video dual layer R-DL is possible. The laser reproducing power suitable for the first recording layer L0 and the second recording layer L1 of the? Can be 0.6 mW, respectively.

The laser reproduction powers suitable for the first recording layer L0 and the second recording layer L1 of the video recordable three layer R-TL that can be written once are 1.2 mW, respectively, and the third recording layer L2 Suitable laser reproduction power is 1.1 mW, and the laser is suitable for the first recording layer L0, the second recording layer L1, and the third recording layer L2 of the once-recordable video 4 layer R-QL. The reproduction power is 1.2 mW, respectively, and the laser reproduction power suitable for the fourth recording layer L3 may be 1.1 mW.

The laser reproduction powers suitable for the first recording layer L0 and the second recording layer L1 of the rewritable video three layer RE-TL are 1.44 mW, respectively, and the laser reproduction power suitable for the third recording layer L2. Since the optical disk drive (ODD: information storage medium reproducing apparatus) is a BD, in the optical disc drive (ODD: information storage medium reproducing apparatus), the type of the disc is accurately determined, and laser reproduction suitable for each recording layer is performed. It must be variable in power.

If the type of the video is incorrectly determined, for example, if the BD-Dual Layer inserted into the drive is incorrectly determined as a BD-3Layer, the optical disc drive (ODD) may use the first recording layer of the BD-Dual Layer. Although the laser regeneration power suitable for L0) is 0.6 mW, it is incorrectly adjusted to 1.2 mW, so that the data recorded in the first recording layer L0 of the BD-Dual Layer is damaged due to the high level laser regeneration power. The problem arises.

While the above has been shown and described with respect to preferred embodiments of the invention, the invention is not limited to the specific embodiments described above, it is usually in the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or prospect of the present invention.

Claims

In the information storage medium,

A first disk layer;

And a second disk layer stacked on the first disk layer.

And the first disk layer and the second disk layer are different in light reflectance.
The method of claim 1,

And an optical reflectance of the first disk layer is higher than that of the second disk layer.
The method of claim 1,

And a third disk layer stacked on the second disk layer.
The method of claim 1,

When a collimator lens of the information storage medium reproducing apparatus is moved to create an optimized focus between the second disk layer and the third disk layer,

And the first disk layer has a maximum light reflectance.
An information storage medium reproducing apparatus,

A laser driver for emitting laser light;

A collimator lens moving to a predetermined position to generate parallel light from the emitted laser light;

An objective lens for incident the parallel light onto an information storage medium;

A photo detector for detecting an intensity of reflected light from the information storage medium and generating an electrical signal; And

And a controller configured to detect a focusing error signal from the electrical signal.

And the multilayer of the information storage medium has different light reflectance.
The method of claim 5,

If the information storage medium has three or more disk layers,

The collimator lens,

And a first disk layer, which is a top layer of the information storage medium, and a second disk layer, which is a next layer of the first disk layer, to move the signal characteristic to be optimized.
The method of claim 5,

The information storage medium,

A multi-layered information storage medium playback apparatus having at least three disk layers.
The method of claim 5,

If the information storage medium has three or more disk layers,

And an optical reflectance of the lowest disk layer of the information storage medium is maximum.