JP2005115986A - Optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk device detecting a stain such as fingerprint unintentionally stuck by the user simplt in a short time and giving a proper warning or the like to a user. <P>SOLUTION: In order to detect a stain such as the fingerprint on a disk medium 9, a tracking servo is removed, an optical head 10 is moved from the inner or the outer to the outer or inner periphery of the disk 9 by a seek motor 13 in a state in which a focus servo only is moved, and the total amount of a reflected light or the signal level of a focus error signal during the movement is detected to determine the degree of the stain based on the size of the signal level. Since the stain is detected within a seeking time, the stain detection is easily carried out within a short time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical disc apparatus for detecting fingerprints, dirt, and the like attached to a disc in an optical disc apparatus that irradiates a disc with a laser beam and records or reproduces the disc on a disc-type recording medium.

Conventionally, Japanese Patent Application Laid-Open No. 2004-151858 discloses detection of contamination on a recording medium on a disk or protection against contamination.
This is a patent related to an optical recording / reproducing device that can detect the degree of dirt such as fingerprints and dust adhering to the surface of a recording medium and warn the user to clean it. Go in number.

  Japanese Patent Laid-Open No. 2004-228688 describes whether the lens is dirty or the surface of the optical disc is higher than the detection level of the focus sum signal performed by the MANUFACTURER'SZONE of the inner peripheral unrecorded portion specified by ISO and the detection level that can be placed in the actual data section. The purpose is to accurately detect whether it is dirty or to prevent deterioration in recording quality.

Patent Document 3 relates to an optical disk reproducing apparatus that can reduce complex track skipping during reproduction caused by scratches on the optical disk or dirt / vibration of the apparatus. Are used to determine whether the track is caused by vibration or due to dirt, and the control for dirt is changed according to the judgment.
The above discloses a technique related to a detection method for dirt on a disk. On the other hand, the thing regarding the process after dirt is shown by the following patent document 4. FIG.

Control the intensity of the recording laser beam irradiated during data recording on a write-once optical disc so that it follows dirt such as fingerprints adhering to the recording surface and does not follow recording surface blur. The present invention relates to a technique for always maintaining an optimal and stable data recording state. The contamination is determined based on the amount of reflected light from the laser, and if it is dirty, the recording power is increased.
The above is a publicly known example related to dirt and the like. In any case, the dirt determination is made at the place, and is a publicly known example related to dealing with dirt in the vicinity.
JP-A-5-314487 JP-A-6-52546 Japanese Patent Laid-Open No. 10-69652 JP 2000-222730 A

  Even if the above-mentioned conventional technology relates to the detection of dirt, the dirt determination is performed in a state where the focus and tracking are operated, and the dirt determination is also the exact place where the focus and tracking are operating. , And some measures are taken against the nearby stains based on the detection result of the location. Therefore, since the condition of the entire disc is not roughly determined, for example, when a user touches the disc unintentionally and a fingerprint is attached, the stain is attached to a large area on the disc. In some cases, no consideration has been given to immediately determining whether the disc is dirty enough to be recorded or reproduced.

  Therefore, for example, it is difficult for the user to accurately determine whether or not the user sees the dirt on the disc and whether or not the dirt is suitable for recording or reproduction. In the prior art, the dirt can be accurately judged. As a method, dirt is judged while recording or playing, and measures are taken on the spot. For example, this disc is roughly divided into a short time before recording or before playing. It was not possible to judge whether it was a recordable or reproducible level of contamination. If the above determination can be made easily, the user can take measures such as wiping dirt or recording on another disk, and the user merit is high.

  It is an object of the present invention to provide an optical disc apparatus capable of detecting dirt easily and in a short time with respect to dirt such as a fingerprint attached unconsciously by the user and issuing an appropriate warning to the user. It is to provide.

  In order to achieve the above object, in the present invention, an optical head that rotates a disk medium, irradiates a predetermined position on the disk medium with a laser beam, receives the reflected light, and a focus direction based on the reflected light. And an actuator for moving in the track direction, a focus position in the previous period, a focus servo means for accurately controlling the track position, a tracking servo means, and a seek motor for moving the optical head to an arbitrary position on the disk And a seek servo means for controlling the reproduction of information recorded at an arbitrary position on the disk or recording information at an arbitrary position by the focus servo and tracking servo. In order to detect dirt such as fingerprints on the top, stop the tracking servo operation. With the focus servo and seek servo in operation, the seek servo means moves the optical head from the inner circumference to the outer circumference, or from the outer circumference to the inner circumference, and the total amount of reflected light from the optical disc during the movement period, Alternatively, the signal level of the focus error signal is detected, and the degree of contamination is determined according to the signal level.

  Here, a large change in the total amount of light means that the amount of reflected light is small, and the amount of dirt is severe (severe). On the other hand, since the change amount of the focus error signal is basically a differential value of the change, even a small amount of dirt (slight dirt) is appropriately determined as dirt. Therefore, if it is severely soiled, it is determined by the total light amount. If it is determined that this amount is soiled, it is naturally impossible to record on the disc. The user is notified through a display unit such as an LCD, and the user cleans or replaces the disc depending on the degree.

  Longitudinal dirt that is judged to be dirty at the focus error signal level is basically recordable, but it is expected that the recording quality will deteriorate, specifically the error rate of the recorded data will deteriorate. This is the case. In this case, the user is warned but recording is possible. For example, this is a process assuming that the content of the video itself is valuable, and it is more important to continue recording even if there is some error rate degradation.

  As is apparent from the above description, the present invention can easily and quickly detect dirt such as fingerprints that the user unconsciously attaches. Furthermore, for example, if the dirt is severe, the user can be instructed to replace or wipe the disc. Even if the dirt is small, the recording is continued but an error may occur. An appropriate warning or the like can be issued, and an optical disk device with high user merit can be provided.

An embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 is a schematic configuration of an optical disc apparatus 1 according to an embodiment of the present invention. Reference numeral 2 denotes a photographing means for forming a subject image on a light receiving surface of an image pickup device section 3 comprising a CCD, an A / D converter, and the like. Reference numeral 4 denotes an image signal processing means for changing an image signal from the image pickup device into image data. The image signal processing means 4 also processes an audio information signal from the microphone 14 which is an audio information signal input means. 6 is a recording / reproducing signal for performing encoding / decoding processing, modulation / demodulation, ECC addition, or conversion to a recording format for recording on the disk-shaped recording medium 9 in order to convert the image data from the image signal processing means 4 into recording data. Processing means. Reference numeral 5 denotes a memory for temporarily storing the recording data, and 8 denotes recording / reproducing means for recording the recording data on the disk-shaped recording medium 9.

  The recording data includes a light emitting element (semiconductor laser) 16 that outputs a light beam with a predetermined power, a light receiving element (photodiode) 17 that detects reflected light from the optical disk 9, a half mirror, a collimator lens, an objective lens, and an objective lens. Recording is performed on an optical disk, which is a recording medium, by an optical head 10 including an actuator 18 that controls the focus and track position of a light beam by driving a lens in a direction perpendicular to the disk surface and in a radial direction. The optical disk 9 is rotated by a spindle motor 19 and moved to an arbitrary position on the optical disk by a seek motor 13 to record recording data at a predetermined location on the optical disk 9.

  In the recording or reproducing position control means 12, servo control necessary for optical recording, for example, a focus servo means for controlling the actuator 18 of the optical head 10 in the forus direction, a tracking servo means for controlling in the tracking direction, and an optical head at an arbitrary position on the disk And a spindle servo means for rotating the disk, etc., and performs accurate position control for the reproduction of the recording data recorded on the disk and the data recorded on the disk. 11 is based on the signal of the light receiving element 17 that detects the reflected light from the optical disk, and detects a focus error signal, tracking error signal, or total light quantity reflected from the disk to detect the deviation of the focus or tracking of the optical head. The reflected light amount detecting means. It is. Control and management of all the above parts are performed by a control microcomputer which is the system control means 7.

For reproduction, the information written on the disk is read by the optical head 10 composed of a photodetector as the difference in the amount of light reflected from the disk reflected by the laser beam, and the recording / reproduction signal processing means 6 passes through the recording / reproduction means 8. And is displayed on the LCD as the image display means 15 through the image signal processing means 4. The system control means 7 also controls and manages these parts.
The display unit 15 is also used, for example, when displaying the result of detecting dirt described later.

Next, an embodiment of a method for detecting dirt on an optical disk according to the present invention will be described with reference to FIG.
In FIG. 2, 9 is an optical disk that is a recording medium, 21 is dirt attached to the optical disk such as a fingerprint, and 22 is an optical head that moves by seek servo and focus servo without operating the tracking servo on the optical disk. It is a trajectory.

  Normally, the track pitch on the optical disk is, for example, 0.625 μm for DVD-RAM and 0.74 μm for DVD-ROM, -R, and -RW. Therefore, when the track is scanned while operating the focus and tracking control The movement path of the optical head is a very dense path. To move from the inner circumference to the outer circumference, the optical disk is rotated. Takes time. In the conventional method for detecting the disc contamination, the focus and tracking are operated, and the total amount of light is observed to detect the contamination by the level change. However, in the above method, it takes several tens of minutes to determine the state of dirt at all positions on the optical disk. When the disk is replaced, it can be determined in a short time whether the disk can be recorded with dirt. Cannot be used if you want to make a decision.

  On the other hand, the dirt on the disk can be dealt with by the error correction capability of the disk system, for example, in the case of dirt of several millimeters such as some kind of dust adhering. For example, a wide range of dirt on the disc, such as fingerprint attachment caused by a user touching carelessly. Therefore, it is ideal that the above-mentioned wide range of dirt can be detected in a short time, and if a wide range of dirt on the disk can be detected in units of several seconds, and some countermeasure can be taken, the user merit is improved. Therefore, in order to detect a wide range of dirt such as fingerprints on the disk medium in a short time, the tracking servo operation is stopped, and the focus servo and seek servo are operated, and the optical head is moved to the disk by the seek servo means. Is moved from the inner circumference to the outer circumference, or from the outer circumference to the inner circumference, and the total amount of reflected light from the optical disk during the movement period or the signal level of the focus error signal is detected, and the degree of contamination according to the signal level Let me judge.

  FIG. 2 is a conceptual diagram, and the number of vortices of the trajectory along which the optical head moves on the optical disk is four. Normally, the disk rotation speed depends on the spindle control, but from 30 rotations / second. Since it is about 100 revolutions / second, when the optical head is moved by the seek motor from the inner circumference side to the outer circumference side in about 0.2 seconds, the number of vortices of the trajectory along which the optical head moves on the optical disk is 6 There are 20 books. In addition, since the size of the fingerprint usually ranges from several tens of millimeters to several centimeters, even if the movement is performed by the 0.2 second seek motor, the fingerprint trace can be traced sufficiently by the head trajectory.

  FIG. 2 shows a case where the optical head traces a dirty portion due to a fingerprint at the A position and the B position for the sake of concept. Therefore, if the dirt can be determined by this trace, the dirt can be determined in 0.2 seconds of one-side seek (seek from the inner circumference side to the outer circumference side). In order to increase accuracy, it is possible to move from the outer periphery to the outer periphery after moving from the inner periphery to the outer periphery, or to decrease the seek speed. The entire dirt can be detected.

  Next, a method of detecting the degree of contamination according to the total light amount change and the focus error signal change amount will be described with reference to FIG. When there is dirt or the like on the disk, the reflected light of the laser incident on the disk is absorbed or diffusely reflected by the dirt portion, so that the amount of light entering the light receiving element through the optical system in FIG. 1 decreases. The eleven reflected light amount detection means detects this as a total light amount change. In addition, since the fluctuation level of the focus error signal in the reflected light amount fluctuates more greatly when the spot of the focus is scanned than when the normal focus moves, the degree of dirt is detected from the fluctuation amount. This mechanism is described in detail below.

FIG. 4 shows a focus error signal detection method using the astigmatism method.
The reflected light in FIG. 1 is focused on the light receiving element and the amount of reflected light is detected. However, if astigmatism is given to the reflected light by a cylindrical lens or a tilted glass plate, two focal lines in directions orthogonal to each other are generated. In the case where it is in the middle position (just focus position), as shown in FIG. 4 (a), the collected light becomes almost circular, but when it is too close and too far Is an ellipse as shown in the figure. Here, the light receiving element is divided into four as shown in FIG. 4A, and ((1) + (3)) − ((2) in the circuit shown in FIG. 4B for each signal. + (4)) is almost zero in the case of just focus, but a negative error signal is generated when the disc approaches the lens, and a positive error signal is generated when the disc is moved away from the error signal amount. The focus servo is controlled so that it is the just focus position. On the other hand, if there is dirt on the disk surface, the amount of dirt is not so much, and even if the total light amount change is small, the focus error signal in FIG. Can also be detected. This is due to the following reason.

  FIG. 5 is a diagram showing a change in the focus error signal when there is dirt on the disk surface. In (a) of the figure, when there is dirt on the disk, the laser beam is focused on the recording surface, so there is a difference in the amount of reflected light with respect to the dirt on the disk surface with respect to a part having a size in millimeters. Occur. Therefore, as shown in the figure, the focus error signal reacts sensitively to level fluctuations due to the division of FIG. 5A and 5B, the focus error signal has a waveform as shown in FIG.

  A large change in the total amount of light means that the amount of reflected light is small, and the amount of dirt is severe (severe). On the other hand, as described above, the amount of change in the focus error signal can be appropriately determined as being dirty even for a small amount of dirt (slight dirt). FIG. 3 shows how the total light amount and the focus error signal change depending on the degree of contamination. FIG. 3A shows a case of severe contamination, where the total light amount and the change amount of the focus error signal are large. Therefore, in this case, it is determined based on the total light amount, and if it is determined that the amount is dirty, it is naturally impossible to perform recording on the disc. Notification is given through a display unit such as an LCD, and the user cleans or replaces the disc depending on the degree.

  In the case of FIG. 3B, the change in the total light quantity is not so much, but the change in the focus error signal is fluctuating more than a certain level. For light stains that are judged to be dirty at the focus error signal level, recording is basically possible, but it is expected that the recording quality will deteriorate, specifically the error rate of the recorded data will deteriorate. This is the case. In this case, the user is warned but recording is possible. For example, this is a process assuming that the content of the video itself is valuable, and it is more important to continue recording even if there is some error rate degradation.

  FIG. 6 describes a method of displaying to the user when it is determined that the dirt is severe, and when it is determined that the dirt is mild but dirty. FIG. 6A shows a case of heavy dirt. For example, if there is a lot of dirt, it is recommended that the user replace the disk or clean the disk. Indicates to the LCD by words or indicates the degree of contamination by an independent display lamp. In this case, since the degree of contamination is poor even after recording, the recording is stopped due to the servo being removed, or even if recording is possible, the recording quality deteriorates due to block noise. It is preferable to make the recording impossible state and request the user to clean the disk or replace the disk.

  As shown in FIG. 6 (b), if it is determined that the stain is mild but dirty, the user is permitted to perform subsequent recording. As described above, since the user inserts a disc into the apparatus in order to record, the process is supposed to prioritize shooting even if the recording quality is somewhat poor. However, since it is necessary to show some information to the user, the expression on the LCD, for example, has detected a level of contamination that has a problem with the recording quality, so it should be conveyed in a language that recommends stopping recording . Alternatively, an independent display lamp may be used to display that light dirt has been detected.

  In the above embodiment, the camera-integrated optical disk apparatus is described. However, the present invention is not limited to this. For example, a recorder or the like may perform the same detection. In this case, the display unit such as an LCD may be the television itself. The input signal may be information from a broadcasting station.

The system block diagram of one Example of this invention. The figure which shows the stain | pollution | contamination detection method of this invention. The figure which shows the signal waveform of dirt. The figure which shows the system of a focus error signal. The figure which shows a focus error signal in case there exists dirt. It is a figure which shows the warning of dirt.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image | photographing means 2 Image | photographing optical system 3 Image pick-up element part 4 Image signal processing means 5 Memory 6 Recording / reproducing signal processing means 7 System control means 8 Recording / reproducing means 9 Optical disk 10 Optical head 11 Reflected light quantity detecting means 12 Recording or reproducing position control means 13 Seek motor 14 Microphone 15 Display means 16 Light emitting element 17 Light receiving element 18 Actuator 19 Spindle motor 20 Dirt display part 21 Dirt 22 Optical head locus 22 Recording / reproducing part

Claims (9)

An optical head that irradiates a predetermined position on the disk medium with laser light and receives the reflected light, an actuator for moving in the focus direction and the track direction based on the reflected light, the focus position, and the track position Focus servo means for accurately controlling the position, tracking servo means, seek motor for moving the optical head to an arbitrary position on the disk medium, and seek servo for controlling movement of the disk to the arbitrary position by the seek motor An optical disc apparatus that reproduces information recorded at an arbitrary position on the disc by the focus servo, tracking servo, and seek servo, or records information at an arbitrary position.
An optical disc apparatus for detecting dirt without performing the tracking servo in order to detect dirt such as fingerprints on the disk medium.   2. The optical disk apparatus according to claim 1, wherein the detection of dirt such as fingerprints on the disk is detected by a change in the total amount of reflected light from the disk of the laser beam.   2. The optical disk apparatus according to claim 1, wherein the detection of dirt such as fingerprints on the disk is detected by a fluctuation amount of a focus error signal based on reflected light from the disk of laser light.   3. The optical disk apparatus according to claim 1, wherein the degree of dirt such as fingerprints on the disk is detected with the tracking servo removed, and the total quantity of light is detected, and the degree of dirt is judged by the quantity of light. Optical disk device.   4. The optical disc apparatus according to claim 1, wherein a fluctuation amount of the focus error signal is detected in a state where a tracking servo is removed and a degree of contamination such as a fingerprint on the disc is removed, and according to the fluctuation amount. An optical disc apparatus characterized by determining a degree of contamination.   6. The optical disk apparatus according to claim 1, wherein the degree of dirt such as fingerprints on the disk is determined by a combination of the total light amount and the fluctuation amount of the focus error signal with the tracking servo removed. An optical disc device characterized by the above.   7. The optical disc apparatus according to claim 6, wherein detection of a case where the degree of contamination is heavy is detected by a total amount of light, and detection of a case where the degree of contamination is mild is executed by a fluctuation amount of a focus error signal.   8. The optical disk apparatus according to claim 6, further comprising display means for displaying to the user that recording cannot be performed when the dirt is determined to be severe.   8. The optical disk apparatus according to claim 6, further comprising display means for displaying the fact that there is dirt at the same time the recording is continued when the dirt is judged to be mild. Optical disk device.

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