JPH06267082A - Optical disc apparatus - Google Patents

Abstract

PURPOSE:To prevent the abrasion/deformation of a stopper, prevent an optical disc from becoming bulky in size, elongate the life of the stopper, positively position a light spot to a PEP part without requiring a complicated part such as a sensor or the like. CONSTITUTION:A stopper 6 is constituted of a first stopper 61 which has a function to stop a movable head 2 moving at normal speeds and a second stopper 62 which has a function to stop the movable head 2 when running wild at high speeds. In the case where the first stopper 61 cannot stop the movable head 2, the second stopper 62 stops the movable head 2 and the PEP part is read.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device, and more particularly to an optical disk device suitable for positioning an optical head on a PEP portion of an optical disk in which information about the optical disk is recorded during initial operation of the optical disk device.

[0002]

2. Description of the Related Art The PEP part of an optical disk is as follows. That is, the ISO standard for a 5.25-inch rewritable optical disk defines several types of information recording formats, methods, and other specifications for the optical disk. The area in which the specifications of this optical disc are recorded is the control track P
In the area called the EP portion, the inside of the user area (area with a disk radius of 30 to 60 mm) (disk radius 29.0)
˜29.5 mm area). The PEP portion is recorded by phase modulation of a low frequency aligned in the radial direction so that the signal can be read even if there is no track, and basic information of 18 bytes is recorded three times in one round. The recorded information includes a servo system, a modulation system, a sector length, a reflectance, a read power and the like. This P
The EP section is composed of a preformat section including an ID section indicating that it is a PEP section and a data section in which the above specifications are recorded, and is read by irradiating the PEP section with a light spot from the movable head. Then, the read system circuit of the optical disk device recognizes the presence of the ID.

The optical disk device reads information from the PEP section, sets the above specifications, and records / reproduces the optical disk. If it is determined from the read information of the PEP section that the optical disc device cannot support the optical disc device, the optical disc device is ejected to the outside of the optical disc device, or the upper device is notified of the fact so that the optical disc is not damaged. Can be processed.

Thus, in the optical disk device,
It is necessary to read the information of the PEP section and initialize the above specifications. For that purpose, when the optical disk is inserted into the optical disk device, it is necessary to position the movable head on the PEP section.

As a conventional method for positioning the initial position of the movable head, for example, as disclosed in Japanese Utility Model Publication No. 3-41336, a detector for detecting that the movable head has reached the initial position is provided. It is known to position the movable head in an initial position by means of a detector.

Further, as a stopper for stopping the movable head, as seen in the magnetic disk device, the stopper is flexed in order to prevent the movable head and the disk from being damaged by absorbing the impact force when the movable head goes out of control. It is known that it is made of a rubber material having a large margin.

[0007]

Taking the 5.25-inch magneto-optical disk currently in practical use as an example, the width of the PEP portion in which information on the optical disk is recorded is 0.5.
mm (area of disk radius 29.0 to 29.5) is narrow. For this reason, the movable head cannot be positioned in the PEP section only by providing the detector for detecting the position of the PEP section as in the above-described conventional technique. That is, in order to position the movable head on the PEP part, in addition to the above-mentioned detector, a position sensor (sensor for detecting the position of the movable head on the optical disk) for positioning the movable head at the detection position is required, Alternatively, it is necessary to position the movable head by providing a speed sensor for the movable head and performing positioning control on the movable head to a detection position indicating the PEP section.

As a means for positioning the movable head on the PEP portion, it is possible to provide a movable head stopper on the PEP portion. However, as described above, in the rubber stopper, the movable head hits the stopper every time the optical disk is inserted, and therefore the stopper is worn and deformed, and the service life cannot be satisfied. Also,
Increasing the amount of deformation of the stopper has a problem of increasing the size of the optical disc device. Further, since the movable head stopper also has a function of protecting the movable head and the optical disk when the movable head goes out of control, it cannot be changed to a rigid material in order to improve the positional accuracy and eliminate wear and deformation.

In addition, in the positioning by the stopper, it becomes difficult to position the movable head on the PEP part when dust enters between the stopper and the movable head or when the stopper is worn for some reason. It becomes impossible to record / play optical discs.

The present invention has been made in view of the above-mentioned problems of the prior art, and is intended to prevent wear and deformation of the stopper when the stopper is used without requiring complicated parts such as a sensor. It is an object of the present invention to provide an optical disk device capable of preventing the optical disk from becoming large in size, extending the life of the stopper, and reliably positioning the light spot on the PEP portion.

[0011]

The first optical disk device of the present invention reads the PEP portion of the optical disk during the initial operation, and has the following features. That is, the first optical disk device of the present invention is equipped with an optical system for forming a light spot on the recording film of an optical disk and reads information from the movable head that moves in the radial direction of the optical disk and the PEP portion of the optical disk. The PEP portion of the optical disc is provided with a stopper for stopping the movable head at a position where the light spot can be irradiated, and the stopper has a first stopper having a function of stopping the movable head moving at a normal speed and a high speed stopper. A second stopper having a function of stopping the movable head in a runaway state. When the first stopper cannot stop the movable head, the second stopper stops the movable head and reads the PEP part. is there.

The second optical disk device of the present invention is
Even if the movable head hits the stopper and stops,
The light spot is not irradiated on the PEP part of the optical disc,
When the P section cannot be read, the fine actuator provided in the movable head is moved in the radial direction of the disk to provide a means for searching the PEP section.

The third optical disk device of the present invention is
It is characterized in that the means for searching the PEP section includes a detector for detecting the position of the fine actuator, and moves the light spot by a predetermined length according to the output of the detector when the PEP section is searched.

The fourth optical disk device of the present invention is
The means for searching the PEP section includes a detector for detecting the speed of the fine actuator, and when the PEP section is searched, the light spot is moved by a certain length according to the output of the detector.

[0015]

According to the present invention, when the optical disk is set in the optical disk device, the movable head is driven in the inner peripheral direction,
The movable head is stopped by the first stopper provided on the stopper and having high positional accuracy. Next, in consideration of variations such as the driving force of the movable head and the frictional force of the movable head, after a certain period of time when the movable head reliably stops at the stopper position,
A light spot is emitted from the movable head to read the PEP section. At this time, if the data cannot be read, the fine actuator is moved in the track direction to search the PEP section. As a result, the reliability is further increased and PEP
The part can be read. At this time, the reliability can be further increased by moving the fine actuator in steps of a constant width by a detector that detects the position of the fine actuator and a detector that detects the speed of the fine actuator.

Further, when an abnormality occurs in the optical disk device,
When the movable head runs out of control, the first stopper cannot receive the movable head, so that the second stopper having a large shock absorbing force can receive the movable head.

Therefore, according to the present invention, it is possible to prevent wear and deformation of the stopper when the stopper is used, to prevent the optical disc from becoming large in size, and to prevent the stopper from being increased without using complicated parts such as a sensor. It is possible to provide an optical disk device which has a long life and which can reliably position the light spot on the PEP part.

[0018]

EXAMPLES Examples of the present invention will be described below. FIG. 1 is an explanatory view showing a cross section of an optical disk device 10 which is an embodiment of the present invention. The optical disk device 10 includes an optical disk 1, a movable head 2 for forming a recording / reproducing light spot on the optical disk 1, an optical system 3 including a laser and a photodetector (not shown) for producing a recording / reproducing signal, The spindle motor 4 for rotating the optical disc 1, the control circuit 5 for controlling these, the movable head 2 and the PEP section 1b.
It is composed of a stopper 6 which is stopped by and a base 7 on which the mechanical parts are mounted. The optical disc 1 has a PEP portion 1b inside the user area 1a.

Here, the stopper 6 includes a first stopper and a second stopper.
It is composed of a stopper. The first stopper is made of a spring material, etc., which has strong repeated proof strength, good wear resistance, and good positional accuracy. It can support a weak force of about 500 g, but a larger force was applied. In that case, it shall have an initial force that cannot hold that position.
The second stopper receives a force at a portion different from that of the first stopper, and does not have repetitive proof strength, abrasion resistance, and dimensional accuracy, but has a large impact absorption capacity, and is made of butyl rubber or the like. It shall be configured. An example of the stopper 6 will be described in detail later with reference to FIGS.

Next, the operation of the optical disk device 10 shown in FIG. 1 will be described. The optical disc 1 is inserted into the optical disc device 10 from the outside by an operator. The optical disc 1 is set on the spindle motor 4 by a loading mechanism (not shown). The optical disc 1 includes the PEP part 1b in which the information of the disc is written in the user area 1a.
On the inner side of. The optical disk device 10 is a PEP
It is necessary to read the information of the section 1b and set the optical disk device 10 to the conditions suitable for the optical disk 1. When the optical disc 1 is set on the spindle motor 4, the movable head 2 of the optical disc device 10 is driven toward the inner circumference at a constant acceleration (driving by constant current or constant voltage). The stopper 6 is provided at a position where the light spot from the movable head 2 enters the PEP portion 1b of the optical disc 1, and the movable head 1 stops at the position of the stopper 6. After that, wait for the time when the movable head 1 hits the stopper 6 with certainty, and the laser of the movable head 2 is emitted to emit the PEP.
The information of the part 1b is reproduced. At this time, the laser output is reproduced with the weakest power (a level that does not destroy the recording area) assuming an abnormal time.

At this time, it is assumed that dust or the like enters between the movable head 2 and the stopper 6 and the movable head 2 is not positioned on the PEP portion 1b of the optical disc 1. The operation at this time is shown in FIG. FIG. 2 is an explanatory diagram showing details of the movable head 1. In FIG. 2, 11 is a light spot position, 12 is a fine (mirror) actuator, 13 is a drive coil, and 14 is a drive coil.
Indicates a position sensor. If the information recorded in the PEP section 1b is not obtained within a fixed time, the PEP section 1b
In order to obtain the information of b, the drive coil 13 is energized to change the angle of the fine actuator 12,
The upper light spot position 11 is moved in the track direction. This driving is performed by causing a constant current to flow in the driving coil 13 of the fine actuator 12 to operate it.

Here, since the light spot position 11 is not moved on the disk 3 over a normally considered fluctuation range, the sensor 1 for detecting the position of the fine actuator 12 is used.
4, the position of the fine actuator 12 is detected, and the light spot position 11 is fed back, so that the reproduction can be performed with high reliability without the light spot position 11 reaching the user area 1a.

FIG. 3 is a block diagram showing an example of the above-mentioned feedback circuit for operating the light spot 11 by a fixed amount. 3, the same parts as those shown in FIG. 2 are designated by the same reference numerals. In FIG. 3, reference numeral 15 is an arithmetic unit such as a microcomputer, 16 is a phase compensation circuit, and 17 is a drive amplifier for energizing the drive coil 13 for driving the fine actuator 12.

First, the arithmetic unit 15 determines the fine actuator 12 according to the displacement amount of the light spot on the optical disc 1.
The displacement amount of is output. According to the displacement amount, a constant current flows from the drive amplifier 17 to the drive coil 13 via the phase compensation circuit 16, and the fine actuator 12 is driven. At this time, the output of the sensor 14 is monitored, the output is fed back as shown, and the fine actuator 1
2 (light spot position on the optical disc 1) is driven with a predetermined swing width. In this example, the position of the fine actuator 12 is detected and fed back by the sensor 14, but the present invention is not limited to this. For example, the speed of the fine actuator 12 may be detected and fed back. good.

Next, the structure of the stopper 6 will be described. FIG. 4 is an explanatory plan view showing a first example of the stopper 6. The stopper 6 is composed of a first stopper 61 and a second stopper 62 fixed to the stopper 6 with high positional accuracy. Here, the stopper 6 is fixed to the base 7 with high positional accuracy. The first stopper 61 is composed of a leaf spring 64 and a screw 63 for fixing the leaf spring 64 to the stopper 6 main body. The first stopper 61 has an initial force that does not deform in the initial operation of the movable head 2. When the movable head 2 runs away and hits the stopper 6, the first stopper 61 cannot support the movable head 2 and hits the second stopper 62. The second stopper 62 is made of butyl rubber or the like, and can be stopped without applying an excessive force to the movable head 2. At this time, since the first stopper 61 is within the elastic deformation, its position (positional accuracy) does not change.

FIG. 5 is an explanatory plan view showing a second example of the stopper 6. The stopper 6 is composed of a first stopper 61 and a second stopper 62 capable of receiving a large impact force, as in the first example shown in FIG. In this second example, the bolts 65 and the nuts 66 are configured to provide positional accuracy of the first stopper 61 and the second stopper 62. However, the base 7 and the first stopper 6
It can also be achieved by increasing the precision of each of the spot positions of the movable head 2. The first stopper 61 normally has an initial force that does not deform in the initial operation of the movable head 2. When the movable head 2 runs away and hits the stopper 6, the first stopper 61 cannot support the movable head 2 and the leaf spring 6
4 bends, and the second stopper 62 strikes the stopper 6 main body. The second stopper 62 is made of butyl rubber or the like, and can be stopped without applying an excessive force to the movable head 2. At this time, since the first stopper 61 is within the elastic deformation, its positional accuracy does not change.

FIG. 6 is an explanatory plan view showing a third example of the stopper 6. The stopper 6 includes a first stopper 61 and a second stopper 62 that can receive a large impact force. The positional accuracy of the stopper 6 can be achieved by increasing the accuracy of the spot positions of the base 7, the first stopper 61, and the movable head 2. The first stopper 61 is
One end is formed to receive the movable head 2, and the other end is composed of a shaft 67 housed in the main body of the stopper 6, and a spring spring 68 provided around the shaft 67. When the movable head 2 hits the first stopper 61 at a normal speed, the spring spring 68 deforms to move the movable head 2
Have the power to receive. The movable head 2 runs away and the stopper 6
When it hits, the first stopper 61 cannot support the movable head 2 and hits the second stopper 62. Second
The stopper 62 is made of butyl rubber or the like and can be stopped without applying an excessive force to the movable head 2. At this time, since the first stopper 61 is within the elastic deformation, its positional accuracy does not change. As is clear from the above description, according to the above-described embodiment, since the movable head is positioned on the PEP portion, it is possible to search for the PEP portion without any special sensor and even if there is some positional deviation. It is possible to provide an optical disk device capable of reproducing a highly reliable disk at a low price.

Further, even when the optical disk device is abnormal, excessive force is not applied to the movable head, so that the movable head is not damaged, no extra cost is required for repairing the optical disk device, and the repair cost is reduced. It is possible to achieve this, and it is also possible to carry out repair of parts at the time of abnormality in a short time.

[0029]

According to the present invention, when a stopper is used without requiring complicated parts such as a sensor, the stopper is prevented from being worn or deformed, and the optical disc is prevented from becoming large. It is possible to provide an optical disk device that can extend the life of the stopper and can reliably position the light spot on the PEP portion.

[Brief description of drawings]

FIG. 1 is an explanatory cross-sectional view of an optical disk device that is an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing details of a movable head.

FIG. 3 is a block diagram showing an example of a circuit for operating a light spot by a fixed amount in a PEP unit.

FIG. 4 is an explanatory view showing the structure of a stopper.

FIG. 5 is an explanatory view showing the structure of a stopper.

FIG. 6 is an explanatory view showing the structure of a stopper.

[Explanation of symbols]

1 ... Optical disc, 1b ... PEP part, 1a ... User area, 2 ... Movable head, 3 ... Optical system, 4 ... Spindle motor, 5 ... Control circuit, 6 ... Stopper, 7 ... Base, 10 ...
Optical disk device, 11 ... Optical spot position, 12 ... Fine actuator, 13 ... Drive coil, 14 ... Sensor, 15
... arithmetic unit, 16 ... phase compensation circuit, 17 ... drive amplifier,
61 ... 1st stopper, 62 ... 2nd stopper ,.

Claims (4)

[Claims] 1. An optical disc apparatus for reading a PEP portion of an optical disc during an initial operation, which has an optical system for forming a light spot on a recording film of the optical disc, a movable head which moves in a radial direction of the optical disc, and a PEP portion of the optical disc. In order to read the above information, the PEP portion of the optical disc is provided with a stopper for stopping the movable head at a position where the light spot can be irradiated, and the stopper has a function of stopping the movable head moving at a normal speed. 1 stopper and a second stopper having a function of stopping the movable head that is in a runaway state at high speed. When the movable head cannot be stopped by the first stopper, the movable head is stopped by the second stopper, An optical disk device characterized by reading a PEP section. 2. Even if the movable head hits the stopper and stops, the PEP portion of the optical disc is not irradiated with the light spot, and the PEP portion cannot be read out. 2. The optical disk device according to claim 1, further comprising means for moving in a radial direction and searching for a PEP section. 3. The means comprises a detector for detecting the position of a fine actuator, and moves the light spot by a fixed length according to the output of the detector when the PEP section is searched. Item 2. The optical disk device according to item 2. 4. The means comprises a detector for detecting the speed of a fine actuator, and moves the light spot by a fixed length according to the output of the detector during the search of the PEP section. Item 2. The optical disk device according to item 2.