JP2002093078A - Optical disk drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the possibility that user data are destroyed in case of trouble since a conventional optical disk drive makes a laser diode emit light for the 1st time after entering the recording area of the user data when reading information. SOLUTION: This optical disk drive can prevent the user data from being destroyed since the laser output is adjusted in an area where the optical disk is absent before information is read out, and also reduce the load to suppress unnecessary heat generation and power consumption as compared with a device which stops a pickup unit from moving by abutting since the pickup unit is stopped at the adjustment position by detecting the position by a contactless position detector and cutting off the supply of a driving current.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for optically reading recorded information from an optical disk, and more particularly to an optical disk apparatus for controlling movement of a pickup unit for power adjustment before reading out a pickup unit.

[0002]

2. Description of the Related Art Optical disks are generally known as typical optical recording media. When reproducing the information stored in the optical disk, the optical disk is mounted on a motor and rotated at a constant speed, and a laser diode (LD) mounted on a pickup unit irradiates a laser beam to perform a focus operation. . Thereafter, the recording area is irradiated with laser light, and information is sequentially read from the reflected light by photoelectric conversion. Then, the information signal is subjected to predetermined processing and reproduced as data. For example, in Japanese Utility Model Laid-Open No. 4-58813, when one disk is selected from a plurality of disks to be stored and mounted, the pickup unit is moved in the inner circumferential direction of the disk. A technique is described in which a focus operation is performed when the position detection unit detects that the pickup unit has reached a predetermined position.

[0003] Conventionally, after the mounting of the disk is completed, the focus operation is started when the pickup unit is moved to reach a predetermined position, but according to this technique, when the mounting of the disk is completed, Since the focus operation has been started, reproduction can be performed immediately after mounting. Therefore, the exchange and the reproduction of the optical disk are completed in a short time, and the reproduction can be started.

[0004]

However, in the technique disclosed in Japanese Utility Model Laid-Open No. 4-58813 described above, the laser diode emits light only after entering the recording area of the disk where the user data is recorded, as in the prior art. Let me. For this reason, when the laser diode emits light with excessive power due to a failure of the automatic output control device (APC), user data may be destroyed. In order to prevent such a problem, before performing the focus operation, be sure to drive the automatic output control device to adjust the power of the laser diode in an area where no data is recorded or a position off the disk surface. Is good. Therefore, the pickup unit is moved to the power adjustment position.

When the moving pickup unit is stopped, the pickup unit is brought into contact with a stopper or the like and stopped to secure an adjustment position. For example, a moving mechanism of the pickup unit employs a ball screw feed mechanism. In this case, since the driving unit of the moving mechanism is about to move even when stopped, the screw or the spring is constantly loaded. Since such a load is repeatedly applied every time the reproduction is started, abrasion or breakage may occur, which is not practical. Even when the moving unit is a voltage-controlled motor (VCM) mechanism, the coil is energized while it is in contact with a stopper or the like, which is disadvantageous in terms of heat generation and efficiency.

Accordingly, the present invention provides a method for adjusting the output of a laser light emitting element of a pickup unit before data is read, in a case where data is not written to the laser light emitting element moved by a drive system for output adjustment. It is an object of the present invention to provide an optical disk device in which unnecessary power is not applied to the pickup unit and the drive system by shutting off and stopping the drive power supplied to the drive system when the power reaches the drive system.

[0007]

In order to achieve the above object, the present invention provides a pickup unit for irradiating a laser beam for reading user data from a mounted optical disk onto the optical disk, and a pickup unit for irradiating the pickup unit in a radial direction of the optical disk. A moving mechanism for moving the pickup unit, an output control unit for controlling a laser output of a laser light emitting element mounted on the pickup unit, and a stop position of the pickup unit moved by the moving mechanism, which is contactless by an optical element. A stop suggestion unit that detects and suggests by optical detection, and when the stop position suggested by the stop suggestion unit is an adjustment position of the laser light emitting element, the pickup mechanism is moved by the moving mechanism. When the adjustment position is reached, the supply of the drive current to the movement mechanism is interrupted to stop the movement. Rutotomoni, to provide an optical disk apparatus to stop emission of the optical element of the stop suggesting unit.

Further, when the optical disk is mounted, the stop suggesting unit suggests a stop position of the pickup unit so that a laser irradiation position by the laser light emitting element is a position where no data is present. Then, the output control unit adjusts so that a desired laser output is output from the laser light emitting element.

In the optical disk device having the above-described configuration, in order to adjust the laser output before reading information, when the pickup unit is moved to a position where there is no data,
If the stop position suggested by the stop suggestion unit is the position where the output adjustment is performed, and if the stop position is reached, the drive current to the moving mechanism is cut off and the movement is stopped. Is eliminated.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a configuration example of an embodiment of an optical disk device according to the present invention. The optical disk device includes a spindle motor 2 having a mounting portion for mounting the optical disk 1 and rotating the optical disk 1 at a constant speed, a spindle driving unit 3 for driving the spindle motor 2, and a pickup unit described later for reading information. 4, an automatic output adjustment unit (APC) 5 for controlling the output of a laser diode provided in the pickup unit 4, and a pickup unit 4
Feed mechanism 6 serving as a drive mechanism for moving the optical disc 1 in a direction connecting the center and the outer circumference of the optical disc 1 (hereinafter referred to as a radial direction), and a thread motor 7 for driving the screw feed mechanism 6
A sled motor driving unit 8 for applying a driving voltage to the sled motor 7, a position detecting unit 9 including an optical sensor such as a retract sensor (LED) for indicating a stop position of the pickup unit 4 in a non-contact manner, The control unit 10 includes a CPU that controls the entire system.

The rotation speed of the disk is detected by using a rotation detection element such as a Hall element (not shown) with a spindle motor 2.
And the rotational speed can be detected from the output signal. By detecting the speed, an error can be detected by adding the movement of the sled motor 7 or the like to the outermost peripheral region, and data destruction in the disk can be prevented.

As shown in FIG. 2, the pickup unit 4 includes a laser diode (L) that emits a laser beam.
D) 11, a collimator lens 12 for converting emitted laser light into parallel light, a beam splitter 13 for polarizing a part of the laser light, an objective lens 14 for converging the irradiated laser light, and a beam splitter 13 Optical sensor (PD) 15 that receives the laser beam polarized by the optical sensor, photoelectrically converts the laser beam, and generates a monitor signal for use in output control.
It is composed of A flag (light-shielding plate) 16 that is inserted into the sensor unit (concave portion) of the position detecting unit 9 so as to shield light from light is attached to the outer peripheral side surface of the pickup unit 4. It is assumed that the user data recorded on the optical disk 1 is read by an optical system (not shown) and a light receiving sensor separately provided in the pickup unit 4.

The position detecting section 9 is a concave non-contact sensor in which a pair of a concave light emitting element 9a and a light receiving element 9b are arranged facing each other as shown in FIG.
The detection signal is output by blocking the light between the light receiving element 9a and the light receiving element 9b. Of course, this non-contact sensor of the opposed arrangement type is an example, and for example, the light emitting element 9a and the light receiving element 9b
May be integrated. As shown in FIG.
The laser beam from the pickup unit 4 is
For example, the pickup unit 4 is attached to a position outside the recording area of the optical disk 1 so as to irradiate an area outside the disk surface of the optical disk 1.
When the flag 16 is inserted through the sensor of the position detector 9, the supply of the drive current to the sled motor 7 is interrupted by an instruction from the controller 10, and the movement of the pickup unit 4 is immediately stopped. At the same time, the light emission of the light emitting element of the non-contact sensor is stopped.

Next, the adjustment of the output of the laser beam in the optical disk device of the present embodiment will be described with reference to the flowchart shown in FIG. First, when the optical disk 1 is mounted on a mounting portion of the spindle motor 2 by a user manually or by an automatic mounting mechanism (step S1),
An instruction is sent from the control unit 10 to the spindle driving unit 3, and the spindle motor 2 is rotated at a desired number of revolutions (step S2), and at the same time, the light emitting element 9a of the non-contact sensor starts emitting light and enters a detectable state. (Step S3). Also,
With this rotation, the screw feed mechanism 6 rotates, and the pickup unit 4 is moved to the outer peripheral side in the radial direction (step S4).

Next, it is determined whether or not the flag 16 of the pickup unit 4 being moved to the outer peripheral side has passed through the sensor portion of the position detecting section 9, that is, whether or not the stop position has been detected (step S5). If the position detection unit 9 detects in this determination (YES), the driving of the thread motor 7 is stopped, and the pickup unit 4 stops in the outer peripheral area where the optical disc 1 is not present as shown in FIG. 3 (step S6).
At the same time, the light emission of the light emitting element of the non-contact sensor is stopped (step S7).

After stopping, the automatic output adjusting unit 5 is driven and controlled by the instruction of the control unit 10, and the laser diode 11 emits a laser beam with a desired laser output (step S8). Then, the laser light is applied to the beam splitter 13.
Then, the light is partially polarized and irradiated on the light receiving surface of the monitoring optical sensor 15. The monitor signal generated by the monitoring optical sensor 15 is fed back to the automatic output adjustment unit 5, and the laser diode 11 is controlled so as to have a desired laser output. Specifically, first, based on the monitor signal, it is determined whether or not the actually output laser output is equal to or less than the upper limit of the window of the desired laser output (step S9). In this determination, if the actual laser output exceeds the upper limit (N
O), the automatic output adjuster 5 adjusts the drive current applied to the laser diode 11 so as to reduce the output (step S10).

Next, the drive current is adjusted so that the laser output decreases, and it is determined whether or not the drive current has reached the lower limit of the laser diode 11 (step S11). This determination is made when the drive current falls below the lower limit that is the rating of the laser diode 11.
This is performed because the laser diode 11 cannot output stable laser light. In this determination, if the drive current does not reach the lower limit (NO), step S7
To determine whether the adjusted laser output has fallen below the window upper limit of the desired laser output. However, if the drive current is lower than the lower limit which is the rating of the laser diode 11 (YES), it is determined that the pickup unit 4 has failed or the characteristics of the laser diode 11 have deteriorated, and replacement or repair is prompted. Therefore, a series of operations is stopped (step S12). In such a case, after stopping, the user may be notified that the operation is not normal by using a warning sound, blinking light or display.

On the other hand, in the determination in step S9,
If the actually output laser output is less than or equal to the desired laser output window upper limit (YES), then it is determined whether the output laser output is equal to or greater than the desired laser output window lower limit (step S13). In this determination, when the actual laser output is below the lower limit of the window of the desired laser output (NO), the automatic output adjuster 5 adjusts the drive current applied to the laser diode 11 so as to increase the output ( Step S14).

Next, the drive current is adjusted so as to increase the laser output, and it is determined whether or not the drive current has reached the upper limit of the laser diode 11 (step S15). This determination is made in order to prevent the pickup unit 4 from being damaged when the drive current exceeds the rated upper limit, or to prevent the damage from spreading if the drive current has already been damaged. In this determination,
If the drive current does not reach the upper limit (NO),
Returning to step S13, it is determined whether the adjusted laser output has exceeded the lower window upper limit of the desired laser output. On the other hand, in step S15, the drive current is
If the value exceeds the upper limit, which is a rating of 1 (YE
S), it is determined that the pickup unit 4 is out of order, and the process proceeds to step S12 to stop a series of operations.

In the determination in step S13,
If the actually output laser output is not less than or equal to the lower limit of the window of the desired laser output (YES), it is determined that the operation is normal, and a normal reading operation is performed (step S16). As described above, when the laser output of the laser diode 11 does not fall within the rated range, the drive current applied to the laser diode 11 is adjusted by feedback control of the automatic output adjustment unit 5. However, when the drive current exceeds the upper limit and the lower limit, it is determined that some failure or failure has occurred in the pickup unit 4, and a series of operations is stopped.

As described above, according to the optical disk device of the present embodiment, the laser output adjustment before reading information is performed in an area where there is no optical disk surface. Is output, the user data is not irradiated, and the destruction of the user data can be prevented. Further, in the present embodiment, the position detector of the pickup unit is a non-contact type, but, for example, if it is possible to immediately stop the movement of the pickup unit by outputting a detection signal at the same time as a contact such as a touch sensor, A similar effect can be obtained with a contact type. However, the use of the non-contact type is more useful because there is less stress on the pickup unit and there is less risk of malfunction due to wear of the contact portion.

Further, in the present embodiment, there is not provided a mechanism for applying a drive current to a drive unit and stopping the drive unit while applying the drive current thereto, instead of detecting a stop position by a position detector and applying the drive current to the drive unit. The drive is stopped, so that no stress is applied to the screw feed mechanism that moves the pickup unit, and the drive current is cut off during the stop, which reduces excess heat and current consumption. It is also useful in

Although the above embodiment has been described, the present invention includes the following inventions. (1) a laser diode (LD), automatic output adjustment (APC) means for controlling the light amount of the LD to a predetermined value, a pickup unit equipped with the LD, a moving means for moving the pickup unit, In an optical disc apparatus having position detecting means for detecting the position of a pickup unit, the position detecting means is installed at a position where the pickup unit can be detected outside the user data area of the optical disc or in an area without the optical disc after the disc is inserted. An optical disk device, wherein power supply to a moving unit is cut off, the pickup unit is stopped, and LD power is adjusted by the APC unit. (2) The optical disk device according to the above (1), wherein the position detecting means is a non-contact type.

[0024]

As described above in detail, according to the present invention, when adjusting the output of the laser light emitting element of the pickup unit before reading data, the laser light emitting element moved by the drive system is used for adjusting the output. Provided is an optical disk device that does not apply an unnecessary load to the pickup unit and the drive system by shutting off and stopping the drive power supplied to the drive system when the data reaches a place where no data is written to the drive system. Can be.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of an embodiment according to an optical disk device of the present invention.

FIG. 2 is a diagram illustrating a specific configuration example of a pickup unit.

FIG. 3 is a view useful for explaining movement to a stop position where laser output is adjusted and stop.

FIG. 4 is a flowchart for explaining output adjustment of laser light in the optical disc device of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical disk 2 ... Spindle motor 3 ... Spindle drive part 4 ... Pickup unit 5 ... Automatic output adjustment part 6 ... Screw feed mechanism 7 ... Thread motor 8 ... Thread motor drive part 9 ... Position detection part 10 ... Control part (CPU) 11 ... Laser diode (LD) 12 ... Collimary lens 13 ... Beam splitter 14 ... Objective lens 15 ... Monitoring optical sensor (PD) 16 ... Flag (light shield plate)

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[Procedure amendment]

[Submission date] September 27, 2000 (2009.2)
7)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007]

In order to achieve the above object, the present invention provides a pickup unit for irradiating a laser beam for reading user data from a mounted optical disk onto the optical disk, and a pickup unit for irradiating the pickup unit in a radial direction of the optical disk. a moving mechanism for moving, and an output control unit for controlling the laser output of the laser light emitting element mounted on said pickup unit, the stop position of the pickup unit is moved by the moving mechanism, the light emitting element及
And a stop suggestion unit that detects and suggests by non-contact optical detection by the light-receiving element and, when the stop position suggested by the stop suggestion unit is the adjustment position of the laser light emitting element, the moving mechanism When the pickup unit is moved to reach the adjustment position, an optical disc device that stops the supply of the driving current to the moving mechanism to stop the movement and stops the light emission of the light emitting element of the stop indication unit. provide.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

The position detecting section 9 is a concave non-contact sensor in which a pair of a concave light emitting element 9a and a light receiving element 9b are arranged facing each other as shown in FIG.
The detection signal is output by blocking the light between the light receiving element 9a and the light receiving element 9b. Of course, this non-contact sensor of the opposed arrangement type is an example, and for example, the light emitting element 9a and the light receiving element 9b
May be integrated. As shown in FIG.
The laser beam from the pickup unit 4 is
For example, the pickup unit 4 is attached to a position outside the recording area of the optical disk 1 so as to irradiate an area outside the disk surface of the optical disk 1.
When the flag 16 is inserted through the sensor of the position detector 9, the supply of the drive current to the sled motor 7 is interrupted by an instruction from the controller 10, and the movement of the pickup unit 4 is immediately stopped. At the same time, a sensor drive (not shown)
The driving of the moving part is stopped, that is, the drive current to the light emitting element 9a is
The supply is stopped, and the light emission of the light emitting element 9a is stopped.

Claims (2)

[Claims] A pickup unit for irradiating the optical disc with a laser beam for reading user data from a mounted optical disc; a moving mechanism for moving the pickup unit in a radial direction of the optical disc; and a laser mounted on the pickup unit. An output control unit that controls the laser output of the light emitting element, and a stop suggestion unit that detects and suggests a stop position of the pickup unit moved by the moving mechanism by non-contact optical detection by an optical element. When the stop position suggested by the stop suggestion section is the adjustment position of the laser light emitting element, when the pickup mechanism is moved by the movement mechanism to reach the adjustment position, While stopping the supply of the drive current to stop the movement, the stop suggestion unit of the optical element Optical disc apparatus characterized by stopping the light. 2. The reading device according to claim 1, wherein the stop suggestion unit suggests a stop position of the pickup unit so that a laser irradiation position of the laser light emitting element is a position where no data is provided, and reads the user data at the stop position. 2. The optical disk device according to claim 1, wherein the output control unit adjusts the laser light emitting element to output a desired laser output.