CN1707634A - Smart Layer Jumping Method - Google Patents

Abstract

An intelligent layer jump method is applied to read a disc by an optical disc machine. The disk has a center reference point, at least one first reflective layer and a second reflective layer. The first reflective layer has a plurality of first tracks, and the second reflective layer has a plurality of second tracks. The method comprises the following steps: focusing the laser beam of the optical disk drive on the first reflecting layer to form a focusing point and obtain an initial position; comparing the relative position of the starting position and the target position on the second reflecting layer to determine the layer jump and the track seeking path of the focus point; and moving the focus point from the initial position to the target position according to the set layer jump and track seeking path.

Description

Smart Layer Jumping Method

technical field

The present invention relates to an intelligent layer-jumping method, and in particular relates to an intelligent layer-jumping method applied to CD drives.

Background technique

With the increasing demand for high-capacity optical storage media, the Digital Versatile Disc (hereinafter referred to as DVD) with more than two layers of reflective layers has increasingly played an important role. Therefore, when reading a DVD disc, how to quickly and stably read the data on the disc so as to reduce the data access time (data access time) is a topic that various manufacturers are devoting themselves to research.

The optical disc drive rotates the disc and moves the pick-up head in the radial direction of the disc, and then uses the laser beam to scan the reflective layer of the disc to access data. Please refer to FIG. 1 , which shows a schematic cross-sectional view of a conventional disk with double-layer reflective layers. The disc 10 has a first reflective layer 102 and a second reflective layer 104, and data is stored in these two reflective layers. In the figure, solid arrows 106 and 108 point away from the center of the disk, and solid arrows 110 and 112 point to the center of the disk. The laser beam is focused on a predetermined reflective layer through the objective lens 114, and then reflected back to an optical detector (not shown in the figure) on the optical pickup head.

Please refer to FIG. 2 , which shows a schematic diagram of the configuration of the photosensitive device on the optical pickup head. The photosensitive device includes six photodiodes, and the part composed of photodiodes 202, 204, 206, 208 can be used to generate a focus error (Focus Error, FE) signal. The magnitude of the focus error signal can be represented by FE=(A+C)-(B+D). The other two photodiodes 210 and 212 are sources of tracking error (Tracking Error, TE) signal, and its magnitude can be written as TE=(F-E).

Please refer to FIG. 3A and FIG. 3B . FIG. 3A shows the situation where the laser beam crosses the track; FIG. 3B shows the corresponding tracking error signal. As the laser beam 304 moves upward, the photodiode 210 receives the reflected light on the track 302 (track), and the photodiode 212 receives the reflected light on the non-track. Therefore, when the signal received by the photodiode 212 is strong, the tracking error signal is positive (TE=F−E>0); otherwise, a negative tracking error signal is generated. If the laser beam is irradiated on the track (or track) at the same time, the intensity of the reflected light received by the photodiode 210 and the photodiode 212 is equal, and the tracking error signal is 0 at this time. Each T represents a period of a tracking crosssignal, as shown in FIG. 3B .

For now, there are many ways to store data on DVD discs, among which, for example, a double-layer disc must have a layer-jump reading mechanism to cooperate. Please return to Fig. 1, in this figure, the objective lens 114 is focusing on the reflective layer 102, and when the optical pickup head wants to read the data on the reflective layer 104, the objective lens 114 will be moved upward so that the focus point 116 falls on the reflective layer 102. on the layer 104 to read the data of the reflective layer 104 . Conversely, if the optical disc drive needs to read the data on the reflective layer 102 back, it will perform a layer jump again, so that the focus point 116 can be reversely moved from the reflective layer 104 to the reflective layer 102 .

However, discs of different specifications manufactured by different disc manufacturers and the eccentricity caused by the spindle motor will cause the disc to vibrate up, down, left, and right during rotation. The degree of shaking will only increase and not decrease. Moreover, the more the outer ring of the disc, the more obvious the degree of shaking. The known layer jump method is to jump directly from an original position on one reflective layer to a target position on another reflective layer, even if the target position is on the outer ring of the disc and is in a violent shaking state. Therefore, it is very likely that the focus point 116 falls between the reflective layer 102 and the reflective layer 104 during layer jumping due to difficulty in focusing, or exceeds the top of the reflective layer 104 to cause focusing failure, which is detected by the optical pickup head at this time. The focus error signals are all 0. In this case, even the focus compensation technology may not help, and because the position of the objective lens 114 is often not known after the layer jump fails, the focusing procedure has to be restarted, resulting in a longer time for refocusing , reducing the efficiency of data access.

Contents of the invention

The object of the present invention is to provide an intelligent layer jumping method, which uses the prior judgment of the relative position between the original position and the target position to determine the subsequent layer jumping path and steps. More specifically, the time point when the layer jump occurs is the position on the inner circle of the disc between the initial track position and the target track position, so as to increase the success rate of focusing after layer jumping, which is an intelligent method. Intelligent layer-hopping method.

According to the above purpose, the present invention proposes an intelligent layer jumping method, which is applied to an optical disk drive to access an optical storage medium such as a disk. The optical storage medium has at least one first reflective layer and one second reflective layer. The first reflective layer has several first tracks, and the second reflective layer has several second tracks. The intelligent layer-jumping method includes the following steps: (a) focusing a light beam on the first reflective layer to form a focus point and obtain a starting position. (b) Comparing the relative position between the starting position and the target position on the second reflective layer, so as to determine the layer jumping and tracking path of the focusing point. (c) Move the focus point from the initial position to the target position according to the set layer jump and tracking path.

Description of drawings

In order to make the above-mentioned objects, features and advantages of the present invention more comprehensible, a preferred embodiment will be described in detail below together with the accompanying drawings.

FIG. 1 shows a schematic cross-sectional view of a conventional disk with double reflective layers.

FIG. 2 is a schematic diagram showing the configuration of the photosensitive device on the optical pickup head.

FIG. 3A shows a situation illustrating a laser beam crossing a track.

FIG. 3B shows the corresponding tracking error signal.

FIG. 4 shows a flowchart illustrating a smart layer-jumping method according to a preferred embodiment of the present invention.

FIG. 5 is a schematic diagram illustrating the first layer-jumping process on the disc according to the intelligent layer-jumping method according to a preferred embodiment of the present invention.

FIG. 6 is a schematic diagram illustrating a second layer-jump process on a disc according to a smart layer-jump method according to a preferred embodiment of the present invention.

FIG. 7 is a schematic diagram illustrating a third layer-jump process on a disc according to a smart layer-jump method according to a preferred embodiment of the present invention.

FIG. 8 is a schematic diagram illustrating a fourth layer-jumping process on a disc by an intelligent layer-jumping method according to a preferred embodiment of the present invention.

FIG. 9 is a schematic diagram illustrating a fifth layer-jump process on a disc according to a smart layer-jump method according to a preferred embodiment of the present invention.

FIG. 10 is a schematic diagram illustrating a sixth layer-jump process on a disc according to a smart layer-jump method according to a preferred embodiment of the present invention.

FIG. 11 is a schematic diagram illustrating a seventh layer jumping process on a disc according to an intelligent layer jumping method according to a preferred embodiment of the present invention.

FIG. 12 is a schematic diagram illustrating an eighth layer-jumping process on a disc according to an intelligent layer-jumping method according to a preferred embodiment of the present invention.

Detailed ways

Because the conventional layer-jump method is prone to focus failure after the layer-jump when the outer track of the disc is at a high speed, the purpose of the present invention is to solve the above problems. A preferred embodiment is described as follows.

Please refer to FIG. 4 to FIG. 6 at the same time. FIG. 4 shows and illustrates the flow of the intelligent layer-jumping method according to a preferred embodiment of the present invention; FIG. Schematic diagram of the first layer-jumping process on the chip; FIG. 6 shows a schematic diagram illustrating the second layer-jumping process on the disc according to the intelligent layer-jumping method according to a preferred embodiment of the present invention.

The intelligent layer jumping method of the preferred embodiment of the present invention is applied to an optical disc drive to access an optical recording medium, such as the disc 10 . The disc 10 has a first reflective layer 102 and a second reflective layer 104 . The first reflective layer 102 has a substantial number of first tracks 1022 and the second reflective layer 104 has a corresponding majority of second tracks 1042 . The disk 10 is preferably a digital versatile disk (Digital Versatile Disk, DVD) with double reflective layers.

In step 402 , firstly, the laser beam emitted by the optical pickup head 118 is focused on the first reflective layer 102 to form a focal point 116 and obtain a starting position 502 , as shown in FIG. 5 .

Next, in step 404, the optical pickup head 118 receives an instruction (instruction) indicating to change layers (layer change). The relative position of the initial position on the upper surface and the target position on the second reflective layer 104 determines the layer jump and seek path of the focus point 116 . Wherein, the relative position between the start position and the target position is judged according to the sector number.

In step 406 , the optical pickup head 118 moves the focus point 116 from the starting position to the target position according to the determined layer jumping and tracking paths. In FIG. 5, when the comparison result is that the target position 504 is located in the inner circle area of the disc 10 relative to the initial position 502, that is, closer to the central reference point 101, the optical disc drive switches to an open loop (open loop) system. . The tracking servo system (seeking servo) drives the optical pick-up head 118 to move toward the direction 110 of the center of the disk, so that the focus point 116 moves to a preparatory layer jump position (beforelaver change position) 506 in a manner of crossing part of the first track 1022, The preparatory layer jump position 506 is relative to the target position 504 . During the tracking process, the seeking servo system (seeking servo) can calculate the number of tracks traversed by the tracking cross signal.

Then in step 410, the focusing servo system (focusing servo) controls the actuator 120 and drives the objective lens 114 to move in the direction 122 perpendicular to the disk, so that the focus point 116 moves up to perform layer jumping. Finally, the focusing point 116 is held on the second reflective layer 104 and moved to the target position 504 following one of the second tracks 1042 , so as to complete the whole process of layer jumping and focusing. At this time, the optical disk drive is in a closed loop system state, and the optical pickup head 118 is controlled by a tracking servo system (tracking servo).

On the contrary, in FIG. 6, when the result of the comparison is that the target position 604 is located in the outer region of the disc 10 relative to the initial position 602, that is, farther away from the central reference point 101, the optical disc drive switches to an open loop. (open loop) system. Then perform the step of focusing layer jumping. The focusing servo system controls the actuator 120 and drives the objective lens 114 to move in the direction 122 perpendicular to the disc, so that the focus point 116 moves up to a corresponding layer jumping position on the second reflective layer 104 ( corresponding layer change position) 606, as in step 412 in FIG. 4 .

In step 414, the tracking servo system controls the optical pick-up head 118 to move in the direction 106 away from the center of the disc, so that the focus point 116 moves to the target position 604 on the second reflective layer 104 by crossing part of the second track 1042 nearby and perform the rail locking procedure. Then, when the focus servo system receives the focus error signal, it means that the track locking procedure has been completed, and the optical disk drive switches to the state of the closed-loop system at this time. Finally, the focusing point 116 moves to the target position 604 along one of the second tracks 1042 on the second reflective layer 104 .

According to the spirit of the intelligent layer-jumping method of the preferred embodiment of the present invention, in addition to the above two layer-jumping processes, other layer-jumping processes are described in sequence as follows:

Please refer to FIG. 7 , which shows a schematic diagram illustrating a third layer jumping process on a disc by an intelligent layer jumping method according to a preferred embodiment of the present invention. When the target position 704 is closer to the central reference point 101 than the starting position 702 , the layer-jumping path is set as a path of tracking, layer-jumping and re-tracking in sequence. The steps are as follows: move the focus point 116 from the initial position 702 to the direction of the central reference point 101 to a preparatory layer jump position 706 on the second reflective layer 104 in a tracking manner, wherein the bit of the preparatory layer jump position 706 The address or time point is closer to the central reference point 101 than the target location 704 . Then, the focus point 116 is moved from the preliminary layer jump position to a corresponding layer jump position 708 on the first reflective layer 102 by layer jumping. The address or time point of the corresponding layer jump position 708 is the same as that of the preliminary layer jump position 706 Same address or point in time. Finally, the focus point 116 is moved from the corresponding layer jump position 708 to the target position 704 in a tracking manner.

Please refer to FIG. 8 , which shows a schematic diagram illustrating a fourth layer-jumping process on a disc by an intelligent layer-jumping method according to a preferred embodiment of the present invention. When the target position 804 is closer to the central reference point 101 than the starting position 802 , the layer-jumping path is set as a path of tracking, layer-jumping and re-tracking in sequence. The steps are as follows: move the focus point 116 from the initial position 802 to the central reference point 101 to cross part of the second track 1042 in a track-following manner, and move to the pre-layer jump position 806 on the second reflective layer 104, The preparatory floor jump position 806 is closer to the central reference point 101 than the target position 804 . Then, the focus point 116 is moved from the preliminary layer jump position 806 to a corresponding layer jump position 808 on the first track 1022 by layer jumping. The address or time point of the corresponding layer jump position 808 is the same as that of the preliminary layer jump position 806 Same address or point in time. Finally, perform track locking and move the focus point 116 from the corresponding layer jump position 808 to the target position 804 in a track-following manner.

Please refer to FIG. 9 , which shows a schematic diagram illustrating the fifth layer-jumping process on the disc according to the intelligent layer-jumping method according to a preferred embodiment of the present invention. When the distance between the target position 904 and the starting position 902 is the same by 101 points from the center reference point and is located on the inner circle of the disk 10 , the focus point 116 is directly moved from the starting position 902 to the target position 904 by layer jumping.

In contrast, please refer to FIG. 10 , which shows a schematic diagram illustrating a sixth layer-jumping process on a disc according to an intelligent layer-jumping method according to a preferred embodiment of the present invention. When the address or time point of the target location 908 is the same as that of the starting location 906, but belongs to the outer track of the disc 10, it is determined that the layer-jumping path is a path of sequential tracking, layer jumping and re-tracking. For example, the second orbit where the starting position is located is the second outermost orbit 914 , and the first orbit where the target position is located is the first outermost orbit 916 . At this time, the steps are as follows: move the focus point 116 from the initial position 914 to the preparatory layer jump position 910 in a track-tracking manner, and the preparatory layer jump position 910 is closer to the central reference point than the initial position 914 and the target position 916 101. The focus point 116 is moved from the preliminary layer jump position 910 to a corresponding layer jump position 912 in a layer jump manner. Finally, the focus point 116 is moved from the corresponding layer jump position 912 to the target position 916 in a tracking manner.

Please refer to FIG. 11 , which shows a schematic diagram illustrating a seventh layer jumping process on a disc according to a smart layer jumping method according to a preferred embodiment of the present invention. When the target position 124 is farther away from the central reference point 101 than the starting position 122 , it is determined that the layer-jumping path is a path of tracking, layer-jumping and re-tracking in sequence. The steps are as follows: firstly, the focusing point 116 is moved from the starting position 122 to a preparatory layer jump position 126 on the first reflective layer 102 in a track-tracking manner, and the address or time point of the preparatory layer jump position 126 is greater than the The starting position 122 is closer to the central reference point 101. Then, the focus point 116 is moved from the preliminary layer jump position 126 to a corresponding layer jump position 128 on the second reflective layer 104 in a layer jump manner, and the address or time point of the corresponding layer jump position 128 is the same as the preliminary layer jump position 126 The same address or point in time. Finally, the focus point 116 is moved from the corresponding layer jump position 128 to the target position 124 in a tracking manner.

Please refer to FIG. 12 , which shows a schematic diagram illustrating an eighth layer-jump process on a disc according to a smart layer-jump method according to a preferred embodiment of the present invention. When the target position 134 is farther away from the central reference point 101 than the starting position 132 , it is determined that the layer-jumping path is a path of tracking, layer-jumping, and re-tracking in sequence. The steps are as follows: first, the focus point 116 is moved from the initial position 132 to a preparatory layer jump position 136 on the first reflective layer 102 in a track-tracking manner, and the address or time point of the preparatory layer jump position 136 is Between the address or time point of the start location 132 and the target location 134 . Next, the focus point 116 is moved from the preliminary layer jump position 136 to a corresponding layer jump position 138 on the second reflective layer 104 in a layer jump manner. Finally, the focusing is completed and the focus point 116 is moved from the corresponding layer jump position 138 to the target position 134 in a tracking manner.

It can be known from the above description that the intelligent layer jumping method of the preferred embodiment of the present invention has the function of intelligent judgment, so that the optical disc player first judges the relative position between the starting position and the target position before executing the focus layer jumping, and then determines a A better layer-hopping path. And no matter what the path is, the focus point is located at the inner circle of the disc when layer jumping is performed. Therefore, the success probability of focusing after layer jumping can be greatly improved, and the deficiency of the known technology can be effectively overcome. In this way, the rotation speed of the optical disk drive can be further accelerated, and the speed of accessing data can be further increased, which greatly improves the competitiveness of the overall product.

In summary, although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make various modifications without departing from the spirit and scope of the present invention. Changes and modifications, so the scope of protection of the present invention should be defined as defined by the patent scope of the application.

Claims (12)

1. intelligent layer jump method, when being used for a CD player access one disc, this disc has a center reference point, at least one first reflection horizon (recoding layer) and one second reflection horizon, this first reflection horizon has a plurality of first tracks (track), this second reflection horizon has a plurality of second tracks, and this method comprises:

One laser beam of this CD player is focused on this first reflection horizon forming a focus point (focal point), and obtain an initial position (original position);

Relatively this reference position be positioned at the relative position of the target location (target position) on this second reflection horizon, with the skip floor that determines this focus point and seek the rail path; And

According to this skip floor and seek the rail path, this focus point is moved to this target location by this reference position.

2. the method for claim 1 is characterized in that, wherein this method also comprises in the step that this focus point is moved to this target location by this reference position:

When this target location with respect to this reference position system during relatively near this center reference point, prior to moving this focus point to one preparation skip floor position (before layer change position) in the mode of crossing over those first tracks of part on this first reflection horizon, this preparation skip floor position is with respect to this target location; And

Carry out focusing and skip, this focus point is moved to this target location.

3. the method for claim 1 is characterized in that, wherein this method also comprises in the step that this focus point is moved to this target location by this reference position:

When this target location distant during with respect to this reference position from this center reference point, carry out earlier focusing and skip, make this focus point move to a corresponding skip floor position (corresponding layer change position) on this second reflection horizon by this reference position; And

On this second reflection horizon, move this focus point to this target location in the mode of crossing over those second tracks of part.

4. the method for claim 1 is characterized in that, wherein this disc be the double-deck reflection horizon of tool a digital multi disc (Digital Versatile Disk, DVD).

5. the method for claim 1 is characterized in that, wherein the relative position of this reference position and this target location is to judge according to the mode of sector number (Sector number).

6. the method for claim 1 is characterized in that, wherein this method also comprises in the step that this focus point is moved to this target location by this reference position:

When this target location than this reference position more near this center reference point, prior to moving this focus point to one preparation skip floor position in the mode of crossing over those first tracks of part on this first reflection horizon, this preparation skip floor position is than more close this center reference point in this target location;

In the skip floor mode focus point is moved to a corresponding skip floor position on this second reflection horizon by this preparation skip floor position, this correspondence skip floor position is than more close this center reference point in this target location; And

On this second reflection horizon, this focus point is moved to this target location by this correspondence skip floor position in the mode of crossing over those second tracks of part.

7. the method for claim 1 is characterized in that, wherein this method also comprises in the step that this focus point is moved to this target location by this reference position:

When this target location than this reference position more near this center reference point, prior to moving this focus point to one preparation skip floor position toward the direction of this center reference point on this first reflection horizon, this preparation skip floor position than this target location further from this center reference point;

In the skip floor mode focus point is moved to a corresponding skip floor position on this second reflection horizon by this preparation skip floor position, this correspondence skip floor position than this target location further from this center reference point; And

On this second reflection horizon, this focus point is moved to this target location by this correspondence skip floor position.

8. the method for claim 1 is characterized in that, wherein this method also comprises in the step that this focus point is moved to this target location by this reference position:

When this target location when all identical apart from this center reference point, this focus point is moved to this target location by this reference position in the mode of skip floor with this reference position.

9. method as claimed in claim 8 is characterized in that, wherein this method also comprises:

In the mode of crossing over those first tracks of part this focus point is moved to a preparation skip floor position by this reference position on this first reflection horizon, this preparation skip floor position is than more close this center reference point of this reference position;

In the skip floor mode this focus point is moved to a corresponding skip floor position on this second reflection horizon by this preparation skip floor position, this correspondence skip floor position is than more close this center reference point in this target location; And

On this second reflection horizon, this focus point is moved to this target location by this correspondence skip floor position in the mode of crossing over those second tracks of part.

10. intelligent layer jump method, in order to a focus point of a CD player is moved to a target location in one second reflection horizon of this disc from an initial position in one first reflection horizon of a disc, this first reflection horizon has a plurality of first tracks, this second reflection horizon has a plurality of second tracks, this reference position is positioned on one of those first tracks, this target location is positioned on one of those second tracks, and this method comprises:

According to this reference position and this target location, determine a skip floor path; And

According to this skip floor path, this focus point is moved to this target location by this reference position.

11. method as claimed in claim 10, it is characterized in that, wherein this disc has a center reference point, this target location is corresponding to the preparation of one on those first tracks skip floor position, the address (address) or the time point of this preparation skip floor position and this target location are identical, and this method also comprises in the step that determines this skip floor path:

When this target location during, determine this skip floor path and be one and follow the rail path of skip floor then earlier than more close this center reference point of this reference position.

12. method as claimed in claim 11 is characterized in that, wherein this method also comprises in the step that this focus point is moved to this target location by this reference position:

In the mode of following rail this focus point is moved to this preparation skip floor position by this reference position; And

Mode with skip floor moves to this target location with this focus point by this preparation skip floor position.

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