KR20070080954A - Method for controlling focus servo in optical disc device - Google Patents

Abstract

A focus servo control method in an optical disc device is provided to more accurately perform focus servo operation by alternately providing a minus focus offset value and a plus focus offset value and determining a focus point at the time when a higher RF(Radio Frequency) signal is detected as the optimum focus point. When printing operation is performed on a label surface of an optical disc(S10-S12), a microcomputer alternately provides a minus focus offset value and a plus focus offset value and detects and stores respective RF signal values(S13,S14). The microcomputer compares the stored respective RF signal values(S15). The microcomputer determines a focus point at the time when a higher RF signal value is detected as the optimum focus point(S16,S17).

Description

Method for controlling focus servo in optical disc device

1 shows a configuration of a general optical disk device,

Figure 2 shows an embodiment of the label side of a typical label printable optical disc,

3 is a flowchart illustrating an operation of a focus servo control method in an optical disk device according to the present invention;

4 illustrates an embodiment in which an optimal focus point is determined according to the present invention.

※ Explanation of code for main part of drawing

10: optical disc 11: optical pickup

12: RF processing unit 13: reproduction digital signal processing unit

14: spindle motor 15: sled motor

16: microcomputer 17: motor drive

18: servo controller 19: memory

20: encoder 21: recording digital signal processing unit

30: Light scribe disk

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus servo control method in an optical disk apparatus. For example, in the case of printing on a label surface of a label printable optical disk such as a light scribe disk, the focus servo operation is more precisely performed. The present invention relates to a focus servo control method in an optical disk apparatus for performing the same.

FIG. 1 illustrates a configuration of a general optical disc device. For example, various types of optical disc devices such as a CD-Recorder or a DVD-Recorder may include an optical disc 10 and an optical pickup. 11), RF processor 12, regenerative digital signal processor 13, spindle motor 14, sled motor 15, microcomputer 16, motor drive 17, servo controller 18, memory 19 ), The encoder 20, the recording digital signal processor 21, and the like.

On the other hand, in the microcomputer 16, when the optical disk 10 is inserted and seated in the apparatus, the servo controller 18 is operated to drive the spindle motor 14 to rotate the optical disk at high speed. In addition, by driving the sled motor 15, the access point of the optical pickup 11 is moved to a specific area such as a lead-in area of the optical disk.

In addition, a focus servo operation for moving the objective lens included in the optical pickup 11 in the vertical direction and a tracking servo operation for moving the objective lens in the left and right directions are performed. For example, a feedback error signal, which is detected while the objective lens moves in the up and down direction, is fed back, and a series of focus servo operations are performed to minimize the focus error signal.

In addition, the microcomputer receives a tracking error signal detected while the objective lens moves in a left and right direction, and performs a series of tracking servo operations to minimize the tracking error signal. In 16, the disk reproducing operation or the recording operation requested by the user can be normally performed together with the above-described focus servo and tracking servo operations.

Recently, optical discs capable of printing labels, such as light scribe discs, have been developed and commercialized. As shown in FIG. 2, opposite to the recording surface of the light scribe disc 30 is shown. Since the label surface formed in the direction is much rougher than the recording surface, a more accurate focus servo control operation is required, but there is no effective solution yet.

Therefore, the present invention was created in view of the above situation, and for example, when printing on a label surface of a label printable optical disc such as a light scribe disk, a minus focus offset By applying the Offset value and the Plus Focus Offset value alternately, the focus point at the point of time when a larger RF signal value is detected is determined to determine the optimal focus point. SUMMARY OF THE INVENTION An object of the present invention is to provide a focus servo control method in an optical disk device for performing accurately.

Focus servo control method in the optical disk apparatus according to the present invention for achieving the above object, when performing a printing operation on the label surface of the optical disk, by applying a negative focus offset value and a positive focus offset value alternately, Detecting and storing respective RF signal values; And comparing the respective stored RF signal values to determine a focus point at the time when a larger RF signal value is detected as an optimal focus point.

In addition, the first step is to detect and store the RF signal value by applying a negative focus offset value during one disc rotation, and then detect and store the RF signal value by applying a positive focus offset value during one disc rotation. The optical disc is a live scribe disc, and the negative focus offset value and the positive focus offset value are set to a specific value in advance.

Hereinafter, a preferred embodiment of a focus servo control method in an optical disk apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

First, the focus servo control method according to the present invention may include a CD recorder or a DVD recorder configured as described above with reference to FIG. 1. It can be applied to an optical disk device.

3 is a flowchart illustrating an embodiment of a method of controlling a focus servo in an optical disk apparatus according to the present invention. For example, when the light scribe disk 30 is inserted into the apparatus (S10), the micom At 16, the servo controller 18 is operated to control the optical disk 14 to be rotated by the spindle motor 14, and the sled motor 15 is used to control the optical pickup 11. Allows the access point to access a specific location on the perimeter of the label face.

In addition, the microcomputer 16 determines the type of the optical disk and performs an initialization operation (S11). For example, in the microcomputer 16, as shown in FIG. After detecting the spoke recorded in the bar shape, the type of the optical disk is determined as a light scribe disk, the index is detected, the control feature is searched, and then the media ID is detected. The media ID is read and a series of operations for confirming the media information is performed.

When the disc discrimination and initialization operation as described above is completed, the microcomputer 16 starts a light scribe print operation according to a user's request (S12). At this time, the servo controller 18 operates. By controlling the focus servo and tracking servo, while performing one rotation of the disk, a preset minus focus offset value is applied and the corresponding RF signal value (for example, RF_M) is applied. It is detected and stored (S13).

In the meantime, the microcomputer 16 applies a preset Plus Focus Offset value while the disk is rotated one by one, and detects and stores the RF signal value (for example, RF_P) accordingly. In operation S14, the respective stored RF signal values are compared to determine an optimal focus point.

For example, in the microcomputer 16, as illustrated in FIG. 4, the RF signal value RF_M detected while the negative focus offset value is given is the RF signal value detected while the positive focus offset value is given. If greater than (RF_P) (S15), the focus operation is controlled by the RF signal detected when the negative focus offset is applied (S16).

On the other hand, if the RF signal value RF_M detected with the negative focus offset value is smaller than the RF signal value RF_P detected with the positive focus offset value, the RF signal detected when the positive focus offset is applied Since the focus operation is controlled at step S17, as shown in FIG. 4, the focus point at the time when the RF signal is detected larger for each section is determined as the optimal focus point, and thus the focus servo is selected. To control the operation.

Then, the microcomputer 16 repeatedly performs the above-described series of operations (S13 to S17) until the print operation is finished (S18), thereby providing a label surface having a surface that is very rough compared to the data recording surface. Also, accurate focus servo control operation can be performed.

Or more, preferred embodiments of the present invention described above, for the purpose of illustration, those skilled in the art, within the technical spirit and the technical scope of the present invention disclosed in the appended claims below, to further improve various other embodiments Changes, substitutions or additions will be possible.

The focus servo control method in the optical disk apparatus according to the present invention made as described above is, for example, in the case of printing on the label surface of a label printable optical disk such as a light scribe disk, the previously set minus A Focus Offset value and a Plus Focus Offset value are applied alternately during each disc rotation to detect and store respective RF signal values, and then store the respective RF signal values. In comparison, by determining the focus point at the time when a larger RF signal value is detected as the optimal focus point, it is possible to perform the focus servo operation on the label surface of the light scribe disk more accurately, thereby printing the label. It is a very useful invention that the operation is normal.

Claims (3)

When performing a printing operation on the label surface of the optical disc, step 1 of alternately applying a negative focus offset value and a positive focus offset value to detect and store respective RF signal values; And And comparing the respective stored RF signal values to determine a focus point at the time when a larger RF signal value is detected as an optimal focus point. The method of claim 1, In the first step, an optical disc detects and stores an RF signal value by applying a negative focus offset value during one disc rotation, and then detects and stores an RF signal value by applying a positive focus offset value during one disc rotation. Focus servo control method in a device. The method of claim 1, And the optical disc is a live scribe disc, and the negative focus offset value and the positive focus offset value are set to a specific value in advance.

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