JP3090126U - Optical disk drive - Google Patents

Abstract

(57) [Problem] To provide an optical disk device with improved usability by suppressing an increase in the cost of the device main body and shortening the time required to determine the type of optical disk set in the main body. An optical disc device (1) is provided so that a laser beam crosses a plurality of tracks in a focus-on state in which a laser beam emitted from a pickup head (3) is focused on a data recording surface of an optical disc (10) set in a main body. Is changed, and the envelope signal is detected from the RF signal detected at this time. From the magnitude of the amplitude level of the detected envelope signal, the optical disk 10 set in the main body is a CD or a DVD. Is determined.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to an optical disk device that determines the type of an optical disk set in a main body, such as a CD or a DVD, and switches the operation according to the determined type.

[0002]

[Prior art]

 2. Description of the Related Art Conventionally, an optical disc apparatus for reproducing a plurality of types of optical discs, such as CDs and DVDs, requires control of reading data from the optical disc and processing of the read data according to the type of the optical disc set in the main body. Since it is necessary to switch the operation of the main body such as control, a function for determining the type of the optical disk set in the main body is provided.

As a configuration for realizing a function of determining the type of an optical disk set in a main body, for example, the focal point of a laser beam radiated from a pickup head, which is disclosed in Japanese Patent Application Laid-Open No. 2000-285592, is focused on the recording surface of the optical disk. In the focus-on state according to, the envelope signal is detected for the RF signal detected when irradiating the laser beam across the track formed on the optical disk, and the amplitude of the envelope signal detected here is detected. And a configuration for determining the type of the optical disk set in the main body, and setting the main body from the waveform of the RF signal level, the waveform of the focus error signal, and the waveform of the tracking error signal disclosed in JP-A-9-320180. Japanese Patent Laid-Open No. H10-14398 No. 4, the configuration outputs a high level when the RF signal is higher than a predetermined level, and determines the type of the optical disc set in the main body from the width of a continuous section of the high level. Proposed.

[0004]

[Problems to be solved by the invention]

 However, since the configuration for determining the type of the optical disk is complicated, there is a problem that providing the configuration increases the cost of the apparatus main body. In addition, since it takes a long time to determine the type of the optical disk, the time from setting the optical disk in the main body to the start of reproduction of data recorded on the optical disk is long, which is convenient for the user. There was no problem.

It is an object of the present invention to provide an optical disk device that has improved usability by suppressing an increase in the cost of the device main body and shortening the time required to determine the type of the optical disk set in the main body.

[0006]

[Means for Solving the Problems]

 The optical disc device of the present invention has the following configuration in order to solve the above problems.

(1) A pickup head that irradiates a laser beam onto a data recording surface of an optical disc set in a main body to detect an RF signal, processes the RF signal detected by the pickup head, and Reproduction signal generation means for generating a reproduction signal of recorded data; type discrimination means for discriminating the type of the optical disc set in the main body; and the type of the optical disc discriminated by the type discrimination means. Control means for switching a signal processing for generating a reproduction signal from the RF signal in the reproduction signal generation means, wherein the type discriminating means focuses the laser light on a data recording surface of the optical disc. With the focused focus on, move up across multiple tracks formed on the optical disc. An envelope signal detection function for detecting an envelope signal from the RF signal detected when the irradiation position of the laser beam is changed, and an envelope signal detected by the envelope signal detection function exceeds a predetermined level. It has a type discrimination result output function of outputting a type discrimination result signal which sometimes becomes high level or low level to the control means.

In this configuration, the envelope signal detecting function provided in the type discriminating means is a focus-on state in which the laser beam emitted from the pickup head is focused on the data recording surface of the optical disc set in the main body. Then, the irradiation position of the laser beam is changed so as to cross a plurality of tracks, and the envelope signal is detected from the RF signal detected at this time.

Normally, if the position of the pickup head is fixed, the irradiation position of the laser beam crosses a plurality of tracks due to the eccentricity of the rotating optical disc. However, the pickup head is moved in the radial direction of the optical disc. Alternatively, the irradiation position of the laser light may be changed so as to cross a plurality of tracks.

As is known, there is a large difference between the amplitude of the envelope signal detected by the envelope signal detection function between the CD and the DVD. Specifically, the envelope signal of a CD has a large amplitude, and the envelope signal of a DVD has a small amplitude. Therefore, it can be determined from the magnitude of the amplitude of the envelope signal whether the optical disc set in the main body is a CD or a DVD.

The type discrimination result output function provided in the type discrimination means is provided when the amplitude of the envelope signal detected from the RF signal exceeds a predetermined level (hereinafter, referred to as a threshold level). Outputs a high-level or low-level signal. This threshold level is a level which does not exceed the envelope signal detected from the RF signal when the optical disk set in the main body is a DVD, and the threshold level when the optical disk set in the main body is a CD. If the envelope signal is detected from the RF signal, the level is set to a level higher than the envelope signal. Therefore, the type discrimination result output function outputs a high-level or low-level signal if the optical disk set in the main unit is a CD, but outputs a high-level or low-level signal if the optical disk set in the main unit is a DVD. Signal is not output.

Further, once the amplitude level of the envelope signal exceeds the threshold level once, if the amplitude level of the envelope signal subsequently falls below the threshold level, the signal level output from the type determination result output function is changed to a high level. Alternatively, the signal level output from the type determination result output function is preferably changed to the opposite level in consideration of the influence of noise.

The control means switches the signal processing in the reproduction signal generation means according to the result of the discrimination by the type discrimination means.

The envelope signal detecting function can be constituted by a low-pass filter, and the type discrimination result output function can be constituted by a comparator. Therefore, the type discriminating means can be realized with a simple configuration, and an increase in the cost of the apparatus body can be suppressed. Further, since the processing for determining the type of the optical disk set in the main body is simple, the time required for determining the type of the optical disk can be reduced, and the usability for the user can be improved.

(2) The pickup head is provided with a plurality of light sources for irradiating a laser beam, and the control unit controls the optical disk according to the type of the optical disk determined by the type determination unit. Select a light source for irradiating laser light.

In this configuration, the light source provided on the pickup head is switched according to the type of the optical disk set in the main body. When reproducing a CD, a laser beam having a wavelength of 780 nm is suitable, and when reproducing a DVD, a laser beam having a wavelength of 650 nm is suitable. However, CD reproduction can be performed even with laser light having a wavelength of 650 nm.

Since the light source provided on the pickup head is switched according to the type of the optical disk set in the main body, the use time of each light source can be reduced, and as a result, the life of the main body of the apparatus can be extended. Can be.

[0018]

[Embodiment of the invention]

 Hereinafter, an embodiment of the optical disk device according to the present invention will be described.

FIG. 1 is a diagram showing a configuration of a main part of an optical disk device according to an embodiment of the present invention. The optical disc apparatus 1 of this embodiment processes a control section 2 for controlling the operation of the main body, a pickup head 3 for reading data recorded on the optical disc 10, and data (RF signal) read by the pickup head 3. A reproducing unit 4 for generating and outputting a reproduction signal; a type discriminating unit 5 for discriminating whether the optical disk 10 set in the main body is a CD or a DVD; and a rotation speed of a spindle motor 6 for rotating the optical disk 10 In addition, focus control for adjusting the focus of the laser light emitted from the pickup head 3 to the recording surface of the optical disk 10 and tracking control for adjusting the irradiation position of the laser light emitted from the pickup head 3 to the center of the track of the optical disk 10 are performed. And a servo control unit 7.

The pickup head 3 includes an LD 3a used when the optical disk 10 set in the main body is a CD (hereinafter, referred to as an LD 3a for CD) and a case where the optical disk 10 set in the main body is a DVD. (Hereinafter referred to as DVD LD3b). The wavelength of the laser light output from the CD LD 3a is 780 nm, and the wavelength of the laser light output from the DVD LD 3b is 650 nm. As is well known, the RF signal output from the pickup head 3 is an output of a light receiving element that detects reflected light from the optical disk 10 irradiated with laser light. The focus control is a control for displacing an objective lens (not shown) provided in the pickup head 3 in a direction perpendicular to the recording surface of the optical disc 10. The tracking control is control for displacing the pickup head 3 in the radial direction of the optical disc 10.

FIG. 2 is a diagram showing a configuration of the type determining unit. An RF signal is input to the type determination 5. The type discriminating unit 5 compares the low-pass filter 11 composed of the resistor R1 and the capacitor C1 with an output level of the low-pass filter 11 and a predetermined level (hereinafter, referred to as a threshold level). And a comparator 12 for outputting a result (determination signal).

Note that R2 and R3 shown in FIG. 2 are resistors for limiting an input current, and V1 is a power supply for determining a threshold level.

Hereinafter, the operation of the optical disc device 1 according to this embodiment will be described. FIG. 3 is a flowchart showing the operation of the optical disk device. When the optical disc 10 is set in the main body, the optical disc apparatus 1 of this embodiment executes a type discriminating process for discriminating whether the optical disc 10 is a CD or a DVD (s1).

FIG. 4 is a flowchart showing the type determination process according to s1. The control unit 2 instructs the pickup head 3 to use the LD 3b for DVD (s11). Further, the control unit 2 instructs the servo control unit 7 to start rotation of the optical disk 10 set in the main body (s12). The servo controller 7 controls the rotation of the spindle motor 6 to start the rotation of the optical disk 10 set in the main body.

The control section 2 instructs the servo control section 7 to turn on the focus (s13). The servo control unit 7 performs a focus-on operation, and focuses the laser light output from the DVD LD 3b on the recording surface of the optical disk 10. Since the details of the focus-on operation are well known, the description is omitted here.

When the focus is turned on, an RF signal is output when the irradiation position of the laser light emitted from the pickup head 3 from the DVD LD 3 b crosses a plurality of tracks formed on the optical disc 10. . More specifically, since the tracking control has not been started at this time, the eccentricity of the optical disk 10 causes a plurality of irradiation positions of the laser light emitted from the DVD LD 3b during one rotation of the optical disk 10. Cross the track. At this time, the position of the pickup head 3 is fixed.

In the case of the optical disk device 1 in which the eccentricity of the optical disk 10 is extremely high, the pickup head 3 is displaced in the radial direction of the optical disk 10 to irradiate the laser beam irradiated from the LD 3b for DVD. May cross multiple tracks.

Here, when the optical disk 10 is a CD, the pickup head 3 outputs an RF signal having a waveform shown in FIG. 5A, and when the optical disk 10 is a DVD, the pickup head 3 outputs the RF signal shown in FIG. An RF signal having the waveform shown is output. As shown in FIG. 5, the envelope signal detected from the RF signal of the CD has a larger amplitude than the envelope signal detected from the RF signal of the DVD (see FIG. 5C).

The RF signal output from the pickup head 3 is input to the low-pass filter 11 of the type determination section 5. The low-pass filter 11 outputs an envelope signal detected from the input RF signal in real time. The output of the low-pass filter 11 is input to the comparator 12. The comparator 12 outputs a comparison result obtained by comparing the preset threshold level with the input output level of the low-pass filter 11 (the level of the envelope signal detected from the RF signal) as a discrimination signal. .

Here, the threshold level preset for the comparator 12 is sufficiently higher than the maximum amplitude level of the envelope signal detected from the DVD RF signal, as shown in FIG. 5C. And a level smaller than the maximum amplitude level of the envelope signal detected from the RF signal of the CD. The comparator 12 outputs a high level when the output level of the low-pass filter 11 is higher than the threshold level, and outputs a low level when the output level of the low-pass filter 11 is lower than the threshold level.

Therefore, when the optical disk 10 set in the main body is a CD, the discrimination signal output from the comparator 12 becomes a pulse signal as shown in FIG. Is a low level signal as shown in FIG. 6 (B).

In the above description, the discrimination signal output from the comparator 12 is high when the output level of the low-pass filter 11 is higher than the threshold level, and the output level of the low-pass filter 11 is lower than the threshold level. It is assumed that the signal is low when the output level of the low-pass filter 11 is higher than the threshold level, and the signal becomes high when the output level of the low-pass filter 11 is lower than the threshold level. Good.

Further, the level of the determination signal when the amplitude level is the threshold level may be a low level or a high level.

The discrimination signal output from the comparator 12 is input to the control unit 2. If the input discrimination signal is a pulse signal, the control unit 2 converts the optical disc 10 set in the main unit into a CD. It is determined that there is a signal (s14, s15), and if the signal is stable at a low level, it is determined that the optical disk 10 set in the main body is a DVD (s14, s16).

In the above operation, when the focus-on operation specified in s13 is completed, the pulse signal shown in FIG. 6 or the low level is stabilized in accordance with the type of the optical disk 10 set in the main body in real time. Since the determined signal is input from the determination unit 5 to the control unit 2, the type of the optical disk 10 set in the main body can be determined in a short time.

Returning to FIG. 3, when the control unit 2 determines that the optical disk 10 set in the main body is a DVD, the control unit 2 instructs the reproduction unit 4 and the servo control unit 7 to start a DVD reproduction operation (s2, s3). The servo control unit 7 performs a track-on operation and starts tracking control.

The focus control has already been started.

After that, the reproducing unit 4 starts reproducing the data recorded on the optical disk 10 (DVD).

Conversely, when the control unit 2 determines that the optical disk 10 set in the main body is a CD, it instructs the pickup head 3 to switch from the LD 3b for DVD to the LD 3a for CD (s2, s4) Then, the reproducing unit 4 and the servo control unit 7 are instructed to start the CD reproducing operation (s5). With switching of the LD in the pickup head 3, the servo control unit 7 performs a focus-on operation and a track-on operation in the CD LD 3a to start focus control and tracking control. Thereafter, the reproducing unit 4 starts a reproducing process of the data recorded on the optical disk 10 (CD).

The optical disc apparatus 1 stops the reproducing operation being executed (s 7) when there is an input instructing to stop the reproducing operation started at s 3 or s 5 (s 7), and ends this processing.

As described above, the optical disk device 1 of this embodiment can determine whether the optical disk 10 set in the main body is a CD or a DVD in a short time. Since the time from when is set on the main body to when the reproduction of the data recorded on the optical disc 10 is started can be shortened, the usability can be improved.

Further, the configuration for determining the type of the optical disk 10 set in the main body is simple, and the increase in the cost of the apparatus main body can be sufficiently suppressed.

Further, since the LD 3a for CD and the LD 3b for DVD are provided in the pickup head 3 and switching is performed according to the type of the optical disk 10 set in the main body, the use time of each LD can be suppressed, and the apparatus main body can be controlled. Life can be extended.

[0044]

[Effect of the invention]

 As described above, according to the present invention, the type of the optical disk set in the main body is determined with a simple configuration, so that an increase in the cost of the apparatus main body can be sufficiently suppressed. In addition, the time required for discriminating the type of the optical disk is short, and the usability of the user can be improved.

Further, since the light source to be used is switched according to the optical disk set in the main body, the use time of each light source can be suppressed, and as a result, the life of the apparatus main body can be extended.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a main part of an optical disc device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a type discriminating unit of the optical disc device according to the embodiment of the present invention.

FIG. 3 is a flowchart showing an operation of the optical disc device according to the embodiment of the present invention.

FIG. 4 is a flowchart showing a disc type discriminating process in the optical disc apparatus according to the embodiment of the present invention.

FIG. 5 is a diagram showing RF signals read from a CD and a DVD.

FIG. 6 is a diagram illustrating an output signal of a comparator.

[Explanation of symbols]

 Reference Signs List 1-optical disk device 2-controller 3-pickup head 3a-LD for CD 3b-LD for DVD 4-playback unit 5-type discriminating unit 11-low-pass filter 12-comparator

Claims (5)

[Utility model registration claims] 1. A pickup head for irradiating a laser beam to a data recording surface of an optical disk set in a main body to detect an RF signal, processing the RF signal detected by the pickup head, and recording the data on the optical disk. Reproduction signal generation means for generating a reproduction signal of the data being read, type discrimination means for discriminating the type of the optical disc set in the main body, and reproduction in accordance with the type of the optical disc discriminated by the type discrimination means. Control means for switching signal processing for generating a reproduction signal from the RF signal in the signal generation means;
In the optical disc apparatus provided with the above, the type discriminating means is configured to traverse a plurality of tracks formed on the optical disc in a focus-on state in which a focus of the laser light is adjusted to a data recording surface of the optical disc. An envelope signal detection function for detecting an envelope signal from the RF signal detected when the light irradiation position is changed, and a high level when the envelope signal detected by the envelope signal detection function exceeds a predetermined level. A type discrimination result output for outputting, to the control means, a type discrimination result signal that is at a level or a low level and does not exceed a predetermined level, and has a level opposite to that when the predetermined level is exceeded; The envelope signal detection function is a low-pass filter; The discrimination result output function is a comparator. Further, the pickup head is provided with a plurality of light sources for irradiating laser light, and the control unit is configured to control the type of the optical disc determined by the type determination unit. An optical disk device for selecting a light source for irradiating the optical disk with laser light. 2. A pickup head for irradiating a laser beam to a data recording surface of an optical disk set in a main body to detect an RF signal, processing the RF signal detected by the pickup head, and recording the data on the optical disk. Reproduction signal generation means for generating a reproduction signal of the data being read, type discrimination means for discriminating the type of the optical disc set in the main body, and reproduction in accordance with the type of the optical disc discriminated by the type discrimination means. Control means for switching signal processing for generating a reproduction signal from the RF signal in the signal generation means;
In the optical disc apparatus provided with the above, the type discriminating means is configured to traverse a plurality of tracks formed on the optical disc in a focus-on state in which a focus of the laser light is adjusted to a data recording surface of the optical disc. An envelope signal detection function for detecting an envelope signal from the RF signal detected when the light irradiation position is changed, and a high level when the envelope signal detected by the envelope signal detection function exceeds a predetermined level. An optical disc device having a type discrimination result output function of outputting a type discrimination result signal of a level or a low level to the control means. 3. The optical disc apparatus according to claim 2, wherein the type determination result signal has a level opposite to that when the envelope signal does not exceed a predetermined level when the envelope signal does not exceed a predetermined level. . 4. The optical disk device according to claim 2, wherein the envelope signal detection function is a low-pass filter, and the type determination result output function is a comparator. 5. The pickup head is provided with a plurality of light sources for irradiating a laser beam, and the control unit controls the laser beam on the optical disk according to the type of the optical disk determined by the type determination unit. The optical disk device according to claim 2, wherein a light source for irradiating light is selected.