JPH1097771A - Disk unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfactorily perform reproduction by constituting the unit of a head for recording or reproducing 1st and 2nd information storage areas, a head moving means and a stopper and reproducing the 2nd information storage area after the head is abutted against the stopper. SOLUTION: A bar code 21 is positioned from a radius R1 to a radius R2, and a position of an objective lens 19 at the time of positioning the optical head by its abutting against the stopper 18a falls within a range from a radius S1 to a radius S2. When the objective lens 19 is in a position of the radius S2, the bar code 21 can be reproduced, and after performing usual operation recovery processing, the bar code reproducing operation is finished. Then, when the objective lens 19 is in a position of the radius S1, the bar code 21 cannot be reproduced, so that turning to objective lens shifting processing 41 and regenerative signal processing 42 are carried out. By constituting the device in such a way, positioning the head in abutting against the stopper is feasible, and hence the bar code in the 2nd information recording area can satisfactorily be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a disk device for recording or reproducing information on a disk such as an optical disk device or a magnetic disk device.

[0002]

2. Description of the Related Art A disk used in an optical disk device or a magnetic disk device has a first information recording area for storing information such as music data accessed by the disk device in a normal operation and files used by a computer. . Separately from the first information recording area, information for preventing unauthorized copying and information such as a manufacturing serial number are coded with a special pattern and stored in the second information recording area. The second information recording area is stored in a format different from that of the first information recording area, and information is accessed by means different from recording and reproduction in the first information recording area.

For example, in the prior art described in Japanese Patent Laid-Open No. 8-102133, in an optical disk device, information for preventing unauthorized copying is added to an optical disk by a bar code. Further, this is a technique of reproducing a barcode with an optical head by the following method.

FIG. 11 is a schematic diagram of an optical disk described in Japanese Patent Application Laid-Open No. 8-102133. In FIG. 11, reference numeral 105 denotes an optical disk, and a bar code 107 is optically processed so as not to cause a reading error of a pit row.
It has been given as. Specifically, it is formed by changing the thickness of the transparent substrate or printing a transparent ink having a different refractive index.

FIG. 12 is an explanatory diagram of a bar code reproducing means of an optical disk device described in Japanese Patent Application Laid-Open No. 8-102133. In FIG. 12A, the objective lens 106 relatively moves from (p1) to (p5) according to the rotation of the disk. At this time, the change of the spot on the detector provided in the optical head changes as shown in FIG. At this time, the focus error signal fluctuates as shown in FIG. This is a technique for reproducing the barcode 107 from the obtained change in the focus error signal.

Next, a conventional head positioning technique for accessing the first information recording area will be described. Generally, the head is positioned at the target track position using the address information recorded in the first information recording area. For example, the prior art relating to an optical disk device described in Japanese Patent Application Laid-Open No. Sho 60-239981 discloses an optical head for an area in which music number data and elapsed time data for each music piece of a CD are recorded, a so-called TOC (Table of contents) area. The positioning is performed by a tracking jump method, and the detection variation of the inner peripheral switch and the drive variation of the feed motor are absorbed. Hereinafter, the prior art described in Japanese Patent Application Laid-Open No. 60-239981 will be described with reference to FIGS.

FIG. 13 is a diagram showing the configuration of an optical disk apparatus used for the conventional optical head positioning technique disclosed in Japanese Patent Application Laid-Open No. Sho 60-239981, and FIG. 14 is a diagram showing the conventional optical head positioning technique disclosed in the same publication. It is operation | movement explanatory drawing.

First, the configuration of an optical disk device used in the prior art will be described with reference to FIG. In FIG. 13, the optical disk 108 is rotatably supported by a disk motor 110 fixed to a fixing portion 109. Optical head 1
Numeral 11 forms a light spot on the optical disk 108 and reproduces information in the optical disk 108. The optical head 111 is moved and supported in the radial direction of the optical disk 108 by the guide support 112 fixed to the fixing unit 109. Optical disk 1
A switch 113 is fixed to the fixed portion 109 on the inner periphery of the reference numeral 08 to detect that the optical head 111 is at the inner peripheral position.

Next, in FIG. 14A, the optical disc 108 has a TOC area at the innermost circumference, and music information from tune number k to k + n is recorded on the outer circumference of the TOC area.

The operation of positioning the optical head 111 in the TOC area in the conventional optical disk apparatus configured as described above will be described with reference to FIG. FIG.
FIGS. 14A to 14E schematically show the positional relationship among the optical head 111, the switch 113, and the TOC area, and FIGS. 14B to 14E list the operation order.

When the optical disk 108 is mounted on the apparatus and the operation starts, as shown in FIG.
1 is moved by the feed motor in the inner circumferential direction, and FIG.
As shown in (c), the switch 113 detects that the optical head 111 is located on the inner circumference. Switch 11
When the position is detected by 3, the driving of the feed motor is reversed for a short time to move the optical head 111 in the outer peripheral direction to the position shown in FIG. In this state, the optical head 111 is started up to start focus control and tracking control. Next, the current head position is obtained from the address information in the disk, and the track jump control is repeated to move the optical head 111 to the inner circumference TOC position as shown in FIG.

As described above, the optical head 111 is positioned at the TOC position by the track jump control.

[0013]

In recent years, disk drives typified by optical disk devices and magnetic disk devices have been required to have low cost and large capacity.

In general, assuming that the area of a disk on which information such as music video and computer file information is recorded is a first information recording area, the first information recording area is expanded toward the inner or outer circumference of the disk. Then, the capacity is increased.

On the other hand, it is an important issue to deal with illegal copies found in pirated versions of CDs. As one of the duplication prevention methods, it is conceivable to add anti-duplication information to a disc in a pattern such as a barcode. That is, if the duplication prevention information and the password do not match, the operation of part or all of the functions of the program is stopped, thereby realizing duplication prevention.

Generally, the duplication prevention information is a bar code or the like, and is formed on the inner periphery of the first information recording area. Assuming that the area in which the duplication prevention information is recorded is a second information recording area, the second information recording area is restricted because the inner peripheral area has an area for holding a disc. For example, in an optical disc device, a barcode that can be reproduced by an optical head is formed as a second information recording area in a limited area on the inner circumference of the optical disc.

An optical disk device described in Japanese Patent Application Laid-Open No. 8-102133, which is a prior art for reproducing a barcode with an optical head, optically writes a barcode on the disk surface to such an extent that the optical head does not cause an error in reading a pit row. Must be processed. If the fluctuation of the focus error signal is output so large that the barcode can be reproduced, there is a problem that the control performance deteriorates because the barcode reproduction signal is mixed as noise into the control signal. Therefore, optical processing is performed on a limited area on the inner or outer peripheral side of the first information recording area.

Similarly, a bar code can be reproduced with an optical head.
In addition, as a method that can be easily added to an optical disk, a method of partially removing the reflective film on the recording surface by using a method such as laser cutting to form a bar code is conceivable. Since the barcode can be written only once for each disk, it is difficult to rewrite information, and individual information can be added to each disk, which is advantageous for preventing duplication.

However, in the above two cases where the bar code is reproduced by the optical head, there is a problem that the optical head must be accurately positioned.

Here, the optical disk apparatus described in Japanese Patent Application Laid-Open No. Sho 60-239981, which is a prior art for positioning an optical head, does not require a switch for detecting the position of the optical head to have a high detection accuracy. Although the positioning can be performed with high accuracy, since the positioning method is based on the track jump control, it is a prerequisite for positioning that the address information is obtained and the tracking control is performed.

In general, address information indicating a track position is not always defined on the inner side or outer side of the first information recording area. Further, in a barcode in which a recording film is cut, tracking control is difficult because an information pit row is cut. Therefore, Japanese Patent Application Laid-Open No. 60-1985 discloses a method for positioning the optical head on a bar code formed on the inner or outer peripheral side of the first information recording area.
The method of positioning an optical head described in US Pat. No. 2,399,81 cannot be applied.

Finally, a method of positioning the optical head with mechanical precision is conceivable. That is, this method is a method in which the feed motor is driven at a fixed value for a fixed time to position the optical head in contact with a stopper provided on the inner or outer circumference. Since the positioning can be performed with the mechanical precision determined by the processing precision and the assembly precision of the individual parts, the positioning can be performed with higher precision than when using a microswitch or the like. However, when the feed motor is driven at a fixed value, positioning becomes difficult due to the following problem. It is necessary to set the drive value of the feed motor as high as not to be affected by the friction of the feed mechanism. This drive value must be set to a sufficiently high drive value in consideration of variations during mass production and changes in the use environment. On the other hand, a feed mechanism is generally provided with a means for preventing an overload of the drive when the operation in the inner and outer peripheral directions is restricted. That is, when the feed motor is further driven after the optical head abuts against the stopper, a means for disengaging the screw portion for transmitting the drive when a predetermined transfer load is exceeded is provided. When the engagement is released, the positioning of the optical head is deviated by the recoil, so that the drive value must be set small enough that the means for preventing overload does not operate. Therefore, when the feed motor is driven at a constant drive value in consideration of variations in mass production such as a friction load, there is a problem that the setting range is extremely limited.

The present invention improves the positioning accuracy of a head with respect to a second information recording area formed on a disk,
An object of the present invention is to satisfactorily reproduce information in a second information recording area where tracking control cannot be performed.

[0024]

In order to solve the above-mentioned problems, the present invention provides a first information recording area and a second information having a format different from that of the first information recording area on the inner or outer peripheral side thereof. First and second discs on which a recording area is formed
A head for recording or reproducing the first and second information recording areas, a head transfer means for transferring the head in a substantially radial direction of the disk, And a stopper for restricting the transfer of the head at a position facing the second information recording area. After the head is brought into contact with the stopper by the head transfer means, the second information recording area is reproduced by the head.

In addition to the above-mentioned means, the head transferring means includes a D
A transmitting means for converting the driving force of the C motor and the DC motor into a head transfer force; and an overload preventing means for cutting off or reducing the driving force to the head to a driving force less than a predetermined value when a predetermined load is applied to the transmission means And pulse driving means for pulse driving the DC motor, and the head comes into contact with the stopper while the DC motor is pulse driven.

The disk device is an optical disk device, wherein the disk is an optical disk, and the head is an optical head configured so that focus control and tracking control of an objective lens can be performed by an objective lens driving unit. The information recording area can be reproduced by controlling the focus and tracking of the objective lens.
The second information recording area is reproduced by controlling the focus of the objective lens.

Furthermore, the frequency of the driving waveform output from the pulse driving means does not match the natural frequency of the support mechanism of the objective lens.

In addition, after the optical head comes into contact with the stopper, the objective lens is moved in a substantially radial direction of the optical disk by the objective lens driving means, and the objective lens and the second optical disk are moved.
With the information recording area.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described by taking a disk device represented by an optical disk device as an example.
This will be described with reference to the drawings. Furthermore, an area of a disc on which information such as music video and the like and file information of a computer are generally recorded is defined as a first information recording area, and a second information recording area, which is copy protection information, is formed by a barcode. Will be described.

(Embodiment) FIG. 1 is a schematic diagram of an optical disk according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view showing the configuration of an optical disk device according to one embodiment of the present invention.

FIG. 3 is an enlarged view of the optical head transfer mechanism according to one embodiment of the present invention. In FIG. 1A, the optical disc 1 has a first information recording area 20 in which music video information and computer file information are recorded. A bar code 21 is formed further inside the first information recording area 20, and the bar code 21 contains information for preventing unauthorized copying and management information such as a manufacturing serial number. The bar code 21 is formed by partially removing the reflective film on the recording surface by using a method such as laser cutting after the optical disc 1 is formed, and has a format different from that of the first information recording area. Here, the barcode 21 corresponds to a second information recording area in claims.

FIG. 1B shows the positional relationship between the first information recording area 20 and the barcode 21 by the radius of the optical disk. The first information recording area 20 extends from the radius R3 to the outermost periphery. The barcode 21 is located within a range from the radius R1 to the radius R2 on the inner periphery of the radius R3. The area between the first information recording area 20 and the barcode 21, that is, the area from the radius R2 to the radius R3 is filled with a pit row representing blank data. At the head of the first information recording area 20, there is a control data area 22 in which physical information on the optical disc 1 is recorded. In the control data area 22, an identifier indicating the presence or absence of the barcode 21 is recorded in addition to the physical information of the disc.

In FIG. 2, the optical disk 1 is rotatably supported by a disk motor 3 fixed to a fixed portion 2. The optical head 4 forms a light spot on the optical disc 1 by the objective lens 19, and records or reproduces information in the first information recording area 20. The optical head 4 reproduces information of the barcode 21.

Further, a pair of guide shafts 5 are fixed to the fixed portion 2 via a guide shaft support portion 7, and the optical head 4 is moved and supported by the pair of guide shafts 5 in the radial direction 6 of the optical disc 1. The moving range of the optical head 4 is fixed
Are limited by the stoppers 18a and 18b provided on the front side.

The stopper 18a limits the movement in the inner circumferential direction, and the stopper 18b limits the movement in the outer circumferential direction. The position of the stopper 18a is set so that the optical head 4 stops at the position where the objective lens 19 and the barcode 21 face each other with the movement restriction. Alternatively, the position of the stopper 18a is set so that the optical head 4 stops at a position facing the barcode 21 when the objective lens 19 is driven in the tracking direction.

Next, the feed screw 8 is disposed substantially in parallel with the guide shaft 5, and one end is fixed to the fixing portion 2 via the feed screw support 11. On the other hand, the other end of the feed screw 8 is directly connected to the rotation shaft of the feed motor 9. The feed motor 9 is fixed to the fixed part 2 by a feed motor support 10. Here, the feed motor 9 is constituted by a DC motor.

Next, in FIG. 3, the screw engaging member 13 is engaged with the feed screw 8 via the elastic member 12 fixed to the optical head 4. Further, the coil spring 14 presses the screw engaging member against the feed screw 8. Here, the elastic member 12 is fixed to the optical head 4 via a mounting angle 15. The regulating guide member 16 is fixed by the mounting angle 15 so as to be close to both side surfaces of the screw engaging member 13.

The operation of the optical disk device of the embodiment configured as described above will be described with reference to the drawings.

First, an overload prevention operation when an overload occurs in the feed mechanism will be described with reference to FIGS. Here, FIG. 4 is a plan view of the overload prevention means according to one embodiment of the present invention.

As a specific example, after the optical head 4 collides with the stopper 18a on the inner peripheral side of the optical disk due to a runaway of the control system, the feed motor 9 is further driven to move the optical head 4 in the inner peripheral direction. Will be described.

When the movement of the optical head 4 is forcibly stopped while the feed motor 9 is driven to rotate in the direction of arrow C, the screw engagement member 13 engaged with the feed screw 8 or the screw engagement An excessive force tends to be applied to the elastic member 12 supporting the member 13.

At this time, the feed screw 8 is
Is pressed in the direction of arrow E to deform the elastic member 12 fixing the screw engaging portion 13. Next, as the elastic member 12 is deformed, only the screw engaging member 13 slightly moves in the direction of arrow E. When the feed screw continues to rotate in the direction of arrow C after the minute movement until one side surface of the screw engaging member 13 and the regulating wall surface 16a come into contact, the movement of the screw engaging member 13 in the direction of arrow E is restricted. Move in the direction of arrow F.

By the displacement in the direction of arrow F, the engagement between the screw engaging member 13 and the feed screw 8 is released. In other words, when a certain load or more is applied, the regulation wall 1
6a, the engagement between the screw engaging member 13 and the feed screw 8 is released, so that an overload state is prevented. When this engagement is released, the elastic energy stored in the elastic member 12 is released, so that the optical head 4 is transferred in the direction opposite to the arrow E.

Next, control processing of the optical disk device will be described. FIG. 5 is a block diagram of a drive circuit of the optical disk device according to one embodiment of the present invention. In FIG. 5, the disk motor 3 is driven at a predetermined rotation speed through the disk motor driving means 24 in accordance with a command from the microprocessor 23. Further, the feed motor 9 is driven with a predetermined drive waveform through the feed motor drive means 25 in accordance with a command from the microprocessor 23. Further, the objective lens 19 is driven through the focus driving unit 26 and the tracking driving unit 27 in the focusing direction and the tracking direction, respectively.

The signal from the optical head 4 is transferred to the head amplifier 28
, A focus error signal 29, a tracking error signal 30, and an RF signal 31 are obtained. Focus error signal 29
And the tracking error signal 30
And is used for focus control and tracking control. The RF signal 31 is converted into a barcode reproduction signal 33 through a
It is processed in 3.

2 and 5, the optical head 4 forms a light spot on the first information recording area 20 of the optical disk 1, and detects a focus error signal 29, a tracking error signal 30, and a track position signal. By using these control signals, a seek operation for moving the optical head 4 in the radial direction 6 is performed to move the light spot to a track on which information is recorded or a track on which information is to be recorded.

When performing the above-mentioned seek operation, the optical head 4 is moved to a desired track position by rotating the feed motor 9 forward or backward.

Next, the barcode reproducing operation will be described in the order of operation. FIG. 6 is a flowchart showing a barcode reproducing procedure according to one embodiment of the present invention.

The initial state of the optical disk device is a normal operation state. That is, the focus control and the tracking control are performed, and the information in the first information recording area 20 can be accessed. In this initial state,
The barcode reproducing operation is started by the occurrence of an event from the host computer or the like. First, a control information area reproduction process 34 is performed to obtain an identifier indicating the presence or absence of a barcode recorded in the control information area 22. Next, a bar code presence / absence determination 35 is performed based on the obtained identifier.
I do. If it is determined from the identifier that there is no barcode, the barcode reproduction process is terminated. If it is determined from the identifier that there is a barcode, settings necessary for barcode reproduction are made. More specifically, in the barcode reproduction condition setting processing 36, the tracking control is canceled and the number of revolutions of the disk motor is set.

The tracking control is canceled for the following reason. First, since the barcode 21 formed on the optical disc 1 is obtained by partially removing the recording surface, the pits are cut. Therefore, the light spot formed by the objective lens 19 is
When it comes to the top, noise due to pit breakage is mixed in the tracking error signal 30. Accordingly, the tracking control becomes unstable depending on the state of the pit being cut. Therefore, the tracking control is canceled so that the objective lens is not erroneously driven due to the influence of noise.

Next, the number of rotations of the disk motor 3 is set in order to reproduce the bar code 21 with a predetermined clock while keeping the speed at which the light spot traverses the bar code 21 constant. The rotation speed is set by the disk motor driving means 24.

When the barcode reproduction condition setting 36 is completed, an optical head transfer process 37 is performed next. In the optical head transfer processing 37, positioning is performed by driving the feed motor 9 and bringing the optical head 4 into contact with the stopper 18a. At this time, the driving of the feed motor 9 is performed with a pulse waveform shown in FIG. In FIG. 7, the vertical axis represents the voltage for driving the feed motor 9, and the horizontal axis represents time. The pulse width Δt1, the pulse interval Δt2, and the peak value Ep are periodically output. This driving waveform is a pulse waveform having a constant frequency up to about several hundred Hz.

The purpose of driving with a pulse waveform is to set the drive value of the feed motor 9 as high as not to be affected by friction and to prevent the means for preventing overload from operating. . This will be described with reference to FIG. FIG. 8 is a diagram showing the relationship between the duty ratio of the drive pulse, the starting voltage, and the voltage at which the mechanism for preventing overload operates.

FIG. 8 is a graph in which the vertical axis represents the pulse height of the pulse drive and the horizontal axis represents the duty ratio of the drive pulse. A constant value drive is represented by a duty of 100%, and a drive waveform having a narrower pulse width as the duty becomes closer to 0%. On this graph, a variation region of the starting voltage and a region in which the overload prevention unit operates are illustrated. A region L is a range in which the starting voltage fluctuates. The region N is a region where the overload prevention means works.

As the duty decreases, the average drive voltage decreases. On the other hand, the response of the overload prevention means is difficult to respond to a pulse of about several hundred hertz, and the average drive voltage acts dominantly. This is because the overload prevention means is a mechanism that operates when a certain amount of energy or more is stored in an elastic member in the mechanism. Therefore, the region N appears in the lower right direction.

On the other hand, if the pulse width Δt1 is equal to or more than a certain value, the feed motor 9 responds, so that even if the duty changes, the start voltage does not change much. Therefore, the region L appears almost flat.

At this time, the region M, which is the difference between the region N and the region L, is the set range of the driving peak value. For example, the pulse waveform shown in FIG. 7 is set in a region M indicated by a circle in FIG.

By the above operation, the drive value of the feed motor 9 can be set to a high drive value that is not affected by friction by driving with a pulse waveform, and the means for preventing overload does not operate. Can be. That is, in the optical head transfer process 37 in the flowchart of FIG. 6, the optical head 4 is brought into contact with the stopper 18a, whereby positioning of the assembled component can be performed with mechanical accuracy.

FIG. 9 shows the positional relationship between the objective lens and the bar code when the optical head transfer processing 37 is completed and the optical head 4 is positioned. In FIG. 9, the horizontal axis represents the radial position of the optical disk, and the barcode 21 is the radius R.
1 and at a radius R2. Objective lens 19 when optical head is positioned by contact with stopper 18a
Is in the range from the radius S1 to the radius S2. This range is determined by the accuracy of each part and the accuracy of assembly.

If the width of the barcode 21 is narrow, the objective lens 1
9 does not face the barcode 21. For example, when the objective lens 19 is at the position of the radius S1, it does not face the barcode 21, so that the barcode 19 cannot be reproduced as it is.

The bar code reproduction signal processing 38 shown in FIG. 6 depends on the positional relationship between the objective lens 19 and the bar code 21.
Since the processing result changes, the processing branches at the bar code check 39. That is, when the objective lens 19 is at the position of the radius S2, the barcode 21 can be reproduced.
After performing the normal operation return process 40, the barcode reproducing operation is ended. On the other hand, when the objective lens 19 is at the position of the radius S1, the process branches to the objective lens shift processing 41 because the barcode 21 cannot be reproduced.

In the objective lens shift process 41, the objective lens 19 is shifted in the outer peripheral direction by ΔR shown in FIG.
Here, the shift amount ΔR of the objective lens 19 is determined by the amount calculated from the component accuracy and the assembly accuracy and the tracking driving means 2.
7 is set based on the amount including the variation. After the objective lens shift processing, a bar code reproduction signal processing 42 is performed.

Based on the processing result of the bar code reproduction signal processing 42, a bar code check 43 is performed. When the barcode 21 can be reproduced, the normal operation return process 40 is performed, and the barcode reproduction operation is ended. When the barcode cannot be reproduced, the normal operation return process 40 is performed after the barcode reproduction error process 44 is performed, and the barcode reproduction operation ends.

The contents of the bar code reproduction signal processing 38 and the bar code reproduction signal processing 42 will be described with reference to FIG. FIG. 10A shows that the light spot is a bar code 21.
FIG. FIG. 10B shows FIG.
FIG. 3 is a diagram showing an RF signal 31 obtained corresponding to 0 (a). FIG. 10C shows the RF signal 31 of FIG.
Bar code reproduction signal 34 obtained through value conversion means 32
FIG.

In FIG. 10A, the light spot is a1
To a7 on the optical disc 1 in order. Of a1 to a7, a1, a3, a5, and a7 are portions having pits, and a2, a4, and a6 are portions from which the recording film has been removed. When the light spot passes through the barcode 21, RF signals 34 of b1 to b7 shown in FIG. 10B are obtained corresponding to a1 to a7.

When the light spot passes through a1, a3, a5, and a7, the reflected light amount corresponding to the passing pit row is
RF signal 31 as shown in b1, b3, b5, b7
Is obtained. On the other hand, when the light spot passes through a2, a4, and a6, the amount of light reflected from the optical disk 1 is reduced, so that the RF signal 31 is b1, b2, b4, and b6.
It is output at a lower level than b3, b5, b7. When the RF signal 31 shown in FIG. 10B is binarized at an appropriate level threshold, a bar code reproduction signal 33 shown in FIG. 10C is obtained. The obtained barcode reproduction signal 33 is processed by the microprocessor 23.

The RF signal 31 hardly changes even when the objective lens 19 shifts by ΔR in the tracking direction. That is, the barcode reproduction signal 34 can be reproduced even when the objective lens 19 is shifted. In addition, it is needless to say that a narrower barcode can be reproduced by setting the shift amount of the objective lens 19 finely and performing barcode reproduction in which the drive amount is divided into a plurality of stages.

Assuming that the bar code is reproduced by shifting the objective lens 19, the stopper 18
It is possible to set the position of a to the inner peripheral side by the tracking movable range. When the position of the stopper 18a is set to the inner peripheral side, the distance between the stopper 18a and the start radius R3 of the information recording area can be increased. In other words, when the inner head seek is performed in the normal operation and the optical head 4 goes over the radius R3 due to a track count error, the collision of the optical head 4 with the stopper 18a can be easily avoided by increasing the distance.

The barcode reproducing operation has been described with reference to the flowchart of FIG. In the above embodiment, the barcode 21 corresponding to the second information recording area in the claims is:
Although the case where the bar code 21 is formed on the outer peripheral side of the first information recording area 20 has been described, the rotation direction of the feed motor 9 is reversed and the stopper 18b is formed. , The reproduction operation can be performed similarly.

If the frequency of the drive waveform of the feed motor when the optical head 4 is brought into contact with the stopper 18a does not match the natural frequency of the support mechanism of the objective lens 19, the control system of the objective lens can be controlled. Adverse effects are reduced. This is because, when the feed motor is driven with a pulse waveform, the optical head 4 is vibrated by the vibration component of the drive waveform, and a resonance state occurs when the natural frequency of the support mechanism of the objective lens 19 and the frequency of the drive waveform match. This is because the amplified vibration becomes a disturbance of the control system.

As described above, in one embodiment of the present invention, the positioning of the optical head is performed by driving the feed motor 9 with a pulse waveform and bringing the optical head 4 into contact with the stopper 18a. As a result, the mechanism for setting the drive value of the feed motor 9 high enough not to be affected by friction and preventing overloading does not operate. As a result, the optical head 4 is positioned at a predetermined position on the inner circumference, and reproduces the bar code on the inner circumference of the optical disk.

Even when the bar code cannot be reproduced because the bar code is not opposed to the objective lens, the bar code can be surely reproduced by reproducing the objective lens while shifting it in the tracking direction. In addition,
Both the optical head positioning operation and the barcode reproducing operation can be performed without the need for tracking control.

Further, although the embodiment has been described with respect to the optical disk device, the above series of operations is the same even in the case of a magnetic disk device as well as the optical disk device.

[0075]

As described above, according to the present invention, by driving the DC motor, which is the feed motor, with a pulse waveform, it is possible to set a drive value which is not affected by friction, and to displace the head. Can be avoided. As a result, the head can be positioned in contact with the stopper, and the bar code, that is, the second information recording area in claims can be reproduced. In addition, since a series of reproduction operations can be performed without requiring address information and tracking control, reproduction can be performed even in the second information recording area where tracking control is not performed.

Further, the optical disc device has a feature that the second information recording area can be surely reproduced by shifting the objective lens mounted on the optical head in the tracking direction.

[Brief description of the drawings]

FIG. 1 is a schematic view of an optical disc according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view showing a configuration of an optical disk device according to an embodiment of the present invention.

FIG. 3 is an enlarged view of an optical head feed mechanism according to one embodiment of the present invention;

FIG. 4 is a plan view of an overload prevention unit according to an embodiment of the present invention.

FIG. 5 is a block diagram of a drive circuit of the optical disc device according to the embodiment of the present invention;

FIG. 6 is a flowchart showing a barcode reproducing procedure according to one embodiment of the present invention;

FIG. 7 is a diagram showing a drive waveform of a feed motor according to an embodiment of the present invention.

FIG. 8 is a diagram illustrating a relationship between a duty ratio of a driving pulse, a starting voltage, and a voltage at which a mechanism for preventing overload operates according to an embodiment of the present invention.

FIG. 9 is a diagram illustrating a positional relationship between an objective lens and a barcode after an optical head transfer process according to an embodiment of the present invention.

FIG. 10 is an explanatory diagram of barcode reproduction signal processing according to one embodiment of the present invention.

FIG. 11 is a schematic view of an optical disk described in Japanese Patent Application Laid-Open No. 8-102133.

FIG. 12 is an explanatory diagram of a bar code reproducing means described in Japanese Patent Application Laid-Open No. 8-102133.

FIG. 13 is a configuration diagram of an optical disk device used for an optical head positioning technology described in Japanese Patent Application Laid-Open No. Sho 60-239981.

FIG. 14 is a diagram illustrating the operation of the optical head positioning technique described in the publication.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk 2 Fixed part 3 Disk motor 4 Optical head 5 Guide shaft 6 Disk radial direction 7 Guide shaft support part 8 Feed screw 9 Feed motor 10 Feed motor support part 11 Feed screw support part 12 Elastic member 13 Screw engaging member 14 Coil spring 15 Mounting angle 16 Regulatory guide member 16a Regulatory wall 16b Regulatory wall 18a Stopper 18b Stopper 19 Objective lens 20 First information recording area 21 Barcode 22 Control information area 23 Microprocessor 24 Disk motor driving means 25 Feed motor driving means 26 Focus driving means 27 tracking driving means 28 head amplifier driving means 29 focus error signal 30 tracking error signal 31 RF signal 32 binarization means 33 barcode reproduction signal 34 control information area Raw processing 35 Bar code presence / absence judgment 36 Bar code reproduction condition setting 37 Optical head transfer processing 38 Bar code reproduction signal processing 39 Bar code check 40 Normal operation return processing 41 Objective lens shift processing 42 Bar code reproduction signal processing 43 Bar code check 44 Bar Code reproduction error processing R1 Inner radius position of bar code R2 Outer radius position of bar code R3 Start radius of information recording area on optical disc △ R Shift amount of objective lens

Claims (5)

[Claims] 1. A first and second discs having a first information recording area and a second information recording area having a format different from that of the first information recording area formed on the inner or outer peripheral side thereof.
A disk device for recording or reproducing the information recording area with the same head, a head for recording or reproducing the first and second information recording areas, and a head transferring means for transferring the head in a substantially radial direction of the disk And a stopper for restricting the transfer of the head at a position where the head and the second information recording area face each other, wherein the head is brought into contact with the stopper by the head transfer means and the second information is stored. A disk device for reproducing a recording area with the head. 2. A head transfer means comprising: a DC motor; a transmission means for converting a driving force of the DC motor into a head transmission force; and a drive force for cutting off the head when a predetermined load or more is applied to the transmission means. Or a pulse driving means for pulse driving the DC motor, wherein the head is brought into contact with a stopper while the DC motor is pulsed. Item 10. The disk device according to Item 1. 3. A disk is an optical disk, and a head is an optical head configured so that focus control and tracking control of an objective lens can be performed by objective lens driving means. A first information recording area of the optical disk focuses on the objective lens. It can be played by controlling and tracking control,
3. The disk device according to claim 2, wherein the second information recording area is reproduced by controlling the focus of the objective lens. 4. The disk device according to claim 3, wherein the frequency of the driving waveform output from the pulse driving means does not match the natural frequency of the support mechanism of the objective lens. 5. After the optical head comes into contact with the stopper, the objective lens is moved in a substantially radial direction of the optical disk by the objective lens driving means, so that the objective lens faces the second information recording area of the optical disk. 4. The optical disk device according to claim 3, wherein: