JP2850880B2 - Optical disc tilt detection method in optical disc apparatus and optical disc apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tilt detection method and an optical disk device for an optical disk device, and more particularly to a tilt detection method for an optical disk having a tilt detector and detecting a tilt amount of the optical disk due to the warp of the optical disk. And an optical disc device provided with the same.

[0002]

2. Description of the Related Art Conventionally, as a tilt detection method in an optical disk device, a tilt detector is installed in an optical head that accesses the optical disk in a radial direction, and a relative position between the optical disk and the optical head at each access position of the optical head is set. There is a method of detecting tilt (tilt) and a method of detecting a relative tilt between the optical disk and the optical head at each access position of the optical head using a light beam of the optical head accessing in a radial direction of the optical disk. .

First, as a prior art of the first tilt detection system in which a tilt detector is installed in an optical head, for example, Japanese Patent Application Laid-Open Nos. 08-036772 and 7-27230.
No. 1 and Japanese Patent Application Laid-Open No. 62-404062.

[0004] Japanese Patent Application Laid-Open No. H08-036772 discloses a system in which tilt detectors are provided on the left and right sides of an actuator for driving an objective lens of an optical head, thereby detecting tilt. JP-A-7-272301 discloses that
There are described a method of detecting tilt by a tilt detector that accesses the optical disk together with the optical head in a radial direction, and a method of using a photodetector that is a component of the optical head as a tilt detector.

Japanese Patent Application Laid-Open No. 62-040632 discloses that the diffracted light of the main beam of the optical head reflected from the track of the optical disk is applied to the outer peripheral side of the optical disk and the inner side of the objective lens of the optical head. A method is described in which a tilt is detected by a pair of tilt detectors (light receivers) opposed to the circumferential side, and the tilt is detected by the detection.

Further, as a prior art of the second tilt detection method using a light beam of an optical head for tilt detection, there is, for example, Japanese Patent Application Laid-Open No. 6-28694. Japanese Patent Application Laid-Open No. 6-28694 discloses that a beam split from a half mirror of an optical head is used as a tilt detection light beam, and the tilt detection light beam is irradiated on an optical disk via a mirror detection half mirror provided particularly. A method is described in which a tilt detection light beam reflected from an optical disc is detected by a photodetector provided particularly, and tilt is detected.

[0007]

However, in each of the above conventional examples, the following problems have occurred. The first problem is that the access time of the optical head becomes long. The reason is that the tilt detector is mounted on the optical head for accessing in the radial direction of the optical disk (in the case of JP-A-8-036772, JP-A-7-272301 and JP-A-62-0406632). , and the addition, mirrors, optical components, such as detection half mirror and a photodetector, a for mounted on the optical head unit for accessing in the radial direction of the optical disc (in the case of JP-a-6-028694 discloses), whereby access This is because the time load becomes heavy.

A second problem is that tilt cannot be detected accurately. This is because noise is generated during the correction operation to detect the tilt while performing the tilt correction operation, and the noise affects the tilt detection circuit.

Further, a third problem is that the time for reproducing information written on the optical disk becomes long.
The reason is that, in order to tilt the optical disk or the optical head to correct the tilt of the optical disk, tilt adjustment is performed after tilt detection, but time is required for this alignment. It is.

[0010]

THE INVENTION The object of the invention is to improve the disadvantages according the prior art has, in particular, a tilt detection method for rapid detection and may optical disk apparatus relative tilt amount between the optical head due to the optical disc warpage, It is an object of the present invention to provide an optical disc apparatus which can set and control an optical axis of an optical head to an optimal state based on the optical disc, and thereby can quickly and accurately detect a relative tilt between the optical disc and the optical head. And

[0011]

According to the first aspect of the present invention, there is provided an optical disk, a spindle motor for driving the optical disk to rotate, an optical head for reading predetermined information from the disk, and and threads for holding the optical head, and a guide mechanism for the thread guides the to reciprocate in the radial direction of the optical disc, the optical disc device including a main body case to be equipped with these housing, the optical disc insertion exhaust During the time between insertion into the outlet and setting to the spindle motor, a tilt detector provided in a fixed portion in the main body case near the optical disk insertion / ejection port detects a tilt amount caused by warpage of the optical disk, This is stored as correction data for correcting the direction of the optical axis of the optical head to the optimal direction.

Therefore, according to the first aspect of the present invention,
Before using the optical disk device (after the optical disk is inserted into the optical disk insertion / ejection opening of the optical disk device and before the optical disk is set on the spindle motor), the optical disk device is provided in a fixed portion inside the optical disk device near the optical disk insertion / ejection opening. The tilt detector can detect the amount of tilt due to the warp of the optical disk, and the tilt detector can be provided in a fixed portion inside the optical disk device that does not perform an access operation, so that the tilt can be accurately detected. Therefore, by using this, the access load is reduced, and the access time can be reduced.

According to the second aspect of the present invention, an optical disk,
A spindle motor for rotating the optical disc, an optical head for reading predetermined information from an optical disc, a thread for holding the optical head, and a guide mechanism for the thread guides to reciprocate in the radial direction of the optical disk , in an optical disk device including a main body case to be equipped with them accommodated in thread described above, equipped with an optical axis adjustment mechanism for an optical head for setting the direction of the optical axis of the optical head in the optimum direction. Further, a tilt detector for detecting a tilt amount due to the warp of the optical disk is mounted on a fixed portion formed near the optical disk insertion / ejection opening formed in the main body case.

An arithmetic control unit for sequentially calculating the amount of tilt in the direction along the radius of the optical disk based on the tilt information from the tilt detector is provided, and the radius of the optical disk calculated by the arithmetic control unit is provided. A memory for storing the amount of tilt along is provided. Furthermore, the arithmetic and control unit described above is that have a tilt correction control function for driving and controlling the optical axis adjustment mechanism for the optical head on the basis of the information on the tilt amount stored in the memory, and employs a configuration that.

Therefore, in the invention according to claim 2,
The tilt due to the warp of the optical disk can be corrected by a tilt correction mechanism of the optical head before using the optical disk device, and the relatively large tilt due to the warp of the optical disk can be corrected before using the optical disk device. By doing so, it is possible to save the time related to the tilt servo when the apparatus is operating (that is, at the time of reproducing the information on the optical disk), and the information processing time can be shortened accordingly.

According to a third aspect of the present invention, in the optical disk device of the second aspect, the tilt detector includes a light beam output unit for outputting a tilt detection beam toward the optical disk, and both sides of the light beam output unit. And one and the other reflected beam light receiving portions provided along the radial direction of the optical disk. Then, the arithmetic control unit described above has adopted a identifies the direction of the warp of the optical disk based on the tilt information that comprise a disc warpage identification functions allowed to store in the memory, that the construction of the tilt detector.

Therefore, in the invention according to claim 3,
In addition to functioning equivalently to the above-described second aspect of the present invention, it is not necessary to determine the direction of the warp of the entire optical disc for each measurement data, so that the data processing time can be shortened as a whole.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. First, FIGS. 1 and 2
In the figure, reference numeral 1 indicates an optical disk device. The optical disk device 1 includes an optical disk 2 for writing and reading information, a spindle motor 3 for rotating the optical disk 2, an optical head 4 for writing information on the optical disk 2 and reading information from the optical disk 2, and a housing for storing them. And a main body case 1A.

As shown in FIGS. 2 and 3, the optical disk apparatus 1 adjusts the direction of the optical axis of the optical head 4 by adjusting the tilt of the optical head 4 (tilting the optical axis). a tilt mechanism 5 serving as an optical axis adjusting mechanism for the optical head to be set in the optimum direction, the thread 6 equipped with the tilting mechanism 5 and the optical head 4 described above, this thread 6 is moved in the radial direction of the optical disc 2 And a tray 8 for pulling the optical disk 2 into the main body case 1A or discharging the optical disk 2 to the outside of the main body case 1A.
And an optical disk insertion / ejection port 9 for tray passage provided in the main body case 1A.

Further, a tilt detector 11 is fixedly provided at a position in the main body case 1A near the optical disk insertion / ejection port 9 described above. Reference numeral 12 denotes a button switch for inserting and ejecting an optical disk. This button switch 1
By turning on (ON) or off (OFF) 2,
The power of a tray transfer means (not shown) for inserting the optical disk 2 into the optical disk device 1 or sending the optical disk 2 to the outside is turned on or off.

The above-described tilt detector 11 has a function of operating together with the operation of inserting the tray 8 equipped with the optical disk 2 into the main body case 1A to detect a tilt in the radial direction caused by the warp of the optical disk 2. ing. Also,
An arithmetic control unit 20 for sequentially calculating the amount of tilt in the direction along the radius of the optical disk 2 based on the tilt information from the tilt detector 11 is provided. The tilt amount in the direction along the radius of the optical disk 2 calculated by the arithmetic control unit 20 is stored in the information storage unit 21.

Furthermore, the calculation control unit 20, a tilt correction control function for driving and controlling the tilt mechanism as described above (optical head for the optical axis adjustment mechanism) on the basis of the involved that information on the tilt amount stored in the information storage section 21 It has. Here, for example, as shown in FIG. 4, the tilt detector 11 includes a light beam output unit 11A that outputs a tilt detection beam toward the optical disk 2, and the optical disk output unit 11A on both sides of the light beam output unit 11A and the optical disk described above. And two reflected beam receiving units 11B and 11C provided along the radial direction.

Further, the arithmetic and control unit 20 identifies the warping direction (whether the concave shape is convex) of the optical disk 2 based on the tilt information from the tilt detector 11 and stores it in the information storage unit 21. It has a disk warpage identification function.

In the above embodiment, the optical disk 2 is inserted into the optical disk insertion / ejection port 9 and is set in the spindle motor 3 until the optical disk 2 is set in the main body case 1A near the optical disk insertion / ejection port 9. The tilt detector 11 provided in the fixed unit detects the amount of tilt due to the warpage of the optical disc 2 and stores the tilt amount in the information storage unit 21 as correction data for correcting the direction of the optical axis of the optical head 4 in the optimal direction. It has become so.

Next, the operation of the above embodiment will be described. First, when the optical disk 2 is inserted into the optical disk device 1, after the power is turned on (ON), the button switch 12 is pressed to activate a tray transfer means (not shown), and the tray 8 is ejected in the arrow direction a in FIG. Let it. Next, when the optical disc 2 is mounted on the ejected tray 8 and the button switch 12 is pressed again, the tray 8 is pulled into the main body case 1A of the optical disc apparatus 1 through the optical disc insertion / ejection opening 9.

In this case, the tilt detector 11 operates together with the operation of inserting the optical disk 2, and detects the tilt caused by the warp of the optical disk 2 through the read / write window 8 A of the tray 8 (see FIG. 1). Along the radial direction of. Then, the tilt amount obtained by detecting the tilt due to the warp of the optical disk 2 along the radial direction of the optical disk 2 is stored in the information storage unit 21 described above.

Here, the graph of FIG.
As shown in (A), the optical disk 2 is warped downward (the lower surface side is concave). Also, the graph of FIG. 6B is for the case where the optical disk 2 is warped upward (the upper surface side is concave) as shown in FIG. 5B.

When the tilt is (+) at the start of the detection by the tilt detector 11, the arithmetic and control unit 20 activates the disk warp discrimination function.
As shown in FIG. 5A, the optical disk 2 is warped downward (the lower surface side is concave), and when the optical disk 2 is also (-), it is upward as shown in FIG. 5B (the upper surface side is concave). Is determined to be warped.

Here, a method of recognizing the (+) and (-) signs of the tilt by the arithmetic control unit 20 will be described.

FIG. 4A shows a case where the above-mentioned optical disk 2 is warped downward at the start of detection by the tilt detector 11. In this case, the light beam B of the tilt detector 11
Is reflected by the recording / reproducing surface 2A of the optical disk 2 and reaches the receiving unit 11B of the tilt detector 11, the arithmetic control unit 20
Recognizes that “tilt is (+)”. Similarly, FIG.
(B) shows a case where the optical disc 2 is warped upward at the start of detection by the tilt detector 11. in this case,
When the light beam B of the tilt detector 11 is reflected on the recording / reproducing surface 2A of the optical disk 2 and reaches the receiving unit 11C of the tilt detector 11, the arithmetic control unit 20 recognizes that "tilt is (-)". I do.

By previously recognizing the sign of the tilt in this way, the trouble of recognizing the measured value as (+) or (-) each time is eliminated, and the calculation speed of the calculation control unit 20 is accordingly reduced. In this respect, there is an advantage that tilt correction can be performed more quickly.

[0032] Thus, in the present embodiment, the (specifically prior to use of the optical disk apparatus 1, after inserting the optical disc 2 to the disc insertion and ejection port 9 of the optical disk apparatus 1, the optical disk 2 is a spindle motor Until the optical disk 2 is set to 3, the tilt amount due to the warp of the optical disk 2 is detected in advance by a tilt detector 11 provided in a fixed portion in the main body case 1A near the optical disk insertion / ejection port 9. By providing the tilt detector 11 in the fixed portion inside the optical disc device 1 that does not perform the access operation, the tilt can be detected accurately, and the access load can be reduced, so that the access time can be reduced.

The tilt due to the warp of the optical disk 2 is corrected by the tilt mechanism 5 of the optical head 4 (optical axis adjusting mechanism for the optical head) before using the optical disk apparatus 1. By correcting the relatively large tilt due to the warp of the optical disk 2 before using the optical disk device 1, the time related to the tilt servo when using the optical disk device 1, that is, when reproducing the information on the optical disk 2, becomes unnecessary. Thus, the information processing time can be reduced.

[0034] Thus, the relative tilt of the correction between the optical disc 2 and the optical head 4, prior to use of the optical disk apparatus 1, the direction of the calculated amount of tilt of the "0", the optical head 4 is tilted by a tilt mechanism 5 or the like so that the optical axis of the optical head 4 is substantially perpendicular to the recording / reproducing surface 16 of the optical disk 2.

[0035]

Since the present invention is constructed and functions as described above, it has the following effects. (1). Having established the tilt detector body Ke <br/> over scan side of the optical disk device without mounting the optical head unit for accessing in the radial direction of the optical disc, the optical head section is lighter, for this reason the optical head section The inertia is significantly reduced,
The access time by the optical head has been reliably reduced. (2). As described above, since the installation tilt detector body to case of the optical disk apparatus, the less affected by the tilt correction operation, therefore, because the noise does not affect the operation circuit during tilt detection Thus, the tilt of the optical disk can be detected more accurately than in the conventional example. (3). As described above, since the tilt detection is performed at the time of inserting the optical disk into the optical disk device (before the writing or reading operation of the optical disk device), the time for tilt detection is unnecessary when using the optical disk device, For this reason, it is possible to shorten the time for reproducing the information written on the optical disk.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view along a line AA of FIG. 1 with a part omitted.

FIG. 3 is a block diagram showing a relationship between a tilt detector disclosed in FIG. 2, an optical axis adjustment mechanism for an optical head, an arithmetic control unit, and the like.

[Figure 4] a view showing an example and an operation example of the tilt detector disclosed in FIG. 2, FIG. 4 (A) the lower surface of the optical disk is concave
FIG. 4 is an explanatory view showing a case of the state (case of FIG. 5A) ;
FIG. 5B shows a case where the upper surface of the optical disk is concave (FIG. 5).
It is an explanatory view showing (case (B)) .

5A and 5B are diagrams showing a state of warpage of the optical disk and a tilt detection operation at that time in the embodiment of the tilt detection method of the optical disk device shown in FIG. 2, and FIG. 5A shows a state where the optical disk is warped downward (optical disk). FIG. 5B is an explanatory view showing a tilt detection operation when the lower surface of the optical disk is concave (FIG. 5B). FIG. 5B is a diagram illustrating tilt detection when the optical disk is warped upward (when the upper surface of the optical disk is concave). Description showing operation
FIG .

FIG. 6 is a graph showing a tilt amount in a diameter region of the optical disc corresponding to the warp of each optical disc shown in FIG. 5; FIG. 6 (A) is a diagram corresponding to the case of FIG. 5 (A); FIG 6 (B) is Ru Oh <br/> diagrammatically corresponding to the case of FIG. 5 (B).

[Explanation of symbols]

Reference Signs List 1 optical disk device 2 optical disk 2A recording / reproducing surface 4 optical head 5 tilt mechanism as optical axis adjusting mechanism for optical head 8 tray 9 optical disk insertion / ejection port 11 tilt detector 11A light beam output units 11B, 11C reflected beam light receiving unit 12 button switch B light beam

Claims (3)

(57) [Claims] 1. A spindle motor for rotating the optical disk, and the light head to read predetermined information from the disk, and thread for holding the optical head, the thread <br/> head is the optical disc of and a guide mechanism for guiding the to reciprocate radially between the optical disc until it is set to the spindle motor is inserted into the optical disk insertion outlet, in the optical disk insertion and ejection port near the body case An optical disc in an optical disc device, wherein a tilt detector provided in a fixed portion detects a tilt amount caused by warpage of the optical disc and stores the data as correction data for correcting an optical axis direction of an optical head in an optimal direction. Tilt detection method. 2. A disc, a spindle motor for rotating the optical disc, an optical head for reading predetermined information from the optical disk, and scan <br/>Re' de for holding the optical head, this thread a guide mechanism for guiding the to reciprocate in the radial direction of the optical disc, the optical disc device including a main body case to be equipped with them accommodated in the thread, to set the optical axis of the optical head in the optimum direction An optical axis adjusting mechanism for an optical head is provided, and a tilt detector for detecting a tilt amount due to the warp of the optical disk is mounted on a fixed portion near an optical disk insertion / ejection opening formed in the main body case. An arithmetic control unit for sequentially calculating a tilt amount in a direction along a radius of the optical disk based on tilt information from a detector is provided. An information storage unit that stores a tilt amount along a radius of the optical disk calculated by the control unit; and the arithmetic control unit controls the light for the optical head based on information on the tilt amount stored in the information storage unit. An optical disc device comprising a tilt correction control function for driving and controlling an axis adjusting mechanism. 3. A light beam output unit that outputs a tilt detection beam toward the optical disc, wherein the tilt detector outputs:
One and the other reflected beam light receiving units provided on both sides of the light beam output unit and along the radial direction of the optical disc, and the arithmetic and control unit is configured to perform the operation based on tilt information from the tilt detector. 3. The optical disk device according to claim 2, further comprising a disk warp identification function for identifying a warp direction of the optical disk and storing the information in the information storage unit.