JP2008041168A - Optical disk play device, optical disk play method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To discriminate a specification of an optical disk to play it. <P>SOLUTION: In an optical disk play device 100, an optical disk drive 101 irradiates an optical disk with laser beam using laser wavelength and the numerical aperture when data is read and reproduced from a DVD. A control part 108 obtains reflected light intensity, and when the reflected light intensity is a first threshold value or more, the control part 108 discriminates a DVD, and when it is a second threshold value or more and less than a first threshold value, the disk is discriminated as an HD DVD, and when it is a third threshold value or more and less than a second threshold value, the disk is discriminated as a CD, and when it is a fourth threshold value or more and less than a third threshold value, the disk is discriminated as a BD, and for the rest, it is discriminated as that a reproducible optical disk is not loaded. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical disc reproducing apparatus, an optical disc reproducing method, and a program suitable for discriminating and reproducing the type of an optical disc standard.

There are various types of optical disc standards such as CD (Compact Disc) and DVD (Digital Versatile Disk). As standards for next-generation optical discs, for example, Blu-ray DISC (registered trademark; hereinafter referred to as “BD”) and HDDVD (High Definition DVD; registered trademark) have been proposed and product development is progressing. Since characteristics such as the wavelength, focal length, and optical pickup numerical aperture (NA) used in each standard are different, conventionally, for example, as in Patent Document 1, a laser beam having a predetermined wavelength or a focal point is used. A plurality of optical pickup units having a distance or the like are used properly to determine the type of optical disc standard.
JP 2006-031779 A

  However, according to the prior art, since the optical disk reproducing apparatus needs to irradiate laser beams of a plurality of wavelengths in order to determine the type of the standard, it takes a long time to determine the standard. The algorithm for doing this was also complex.

  The present invention solves such problems, and an object of the present invention is to provide an optical disc playback apparatus, an optical disc playback method, and a program suitable for discriminating and playing back the types of optical disc standards.

In order to achieve the above object, an optical disc playback apparatus according to a first aspect of the present invention is an optical disc playback apparatus that plays back an optical disc that complies with any of a plurality of standards including the first standard and the second standard. And an irradiating means, a control means, a reflected light acquiring means, a standard determining means, and a reproducing means.
The irradiating means irradiates the optical disk with laser light having a predetermined wavelength.
The control means performs focus control for controlling the position of the objective lens so that the laser light emitted from the irradiation means is focused on the optical disk.
The reflected light acquisition means acquires the intensity of the reflected light from the optical disk of the laser light irradiated by the irradiation means.
The standard discriminating unit discriminates the type of the optical disc standard based on the intensity acquired by the reflected light acquiring unit.
The reproducing means reads out and reproduces the data recorded on the optical disc based on the determination result determined by the standard determining means.
The standard discriminating unit discriminates that this optical disc is an optical disc conforming to the first standard when the intensity obtained by the reflected light obtaining unit is equal to or higher than the first threshold, and obtained by the reflected light obtaining unit. If the intensity is greater than or equal to the second threshold smaller than the first threshold and less than the first threshold, it is determined that this optical disc is an optical disc compliant with the second standard.

In order to achieve the above object, an optical disk reproducing apparatus according to another aspect of the present invention is an optical disk reproducing apparatus for reproducing an optical disk compliant with any one of a plurality of standards including a first standard and a second standard. , An irradiation means, a first control means, a second control means, a reflected light acquisition means, a tracking discrimination means, a standard discrimination means, and a reproduction means.
The irradiating means irradiates the optical disk with laser light having a predetermined wavelength.
The first control means performs focus control for controlling the position of the objective lens so that the laser light emitted from the irradiation means is focused on the optical disk.
The second control means performs tracking control for controlling the laser light emitted by the irradiation means to be applied to a track including a pit row on the recording surface of the optical disc.
The reflected light acquisition means acquires the intensity of the reflected light from the optical disk of the laser light irradiated by the irradiation means.
The tracking control unit determines whether or not the tracking control by the second control unit is successful.
The standard discriminating unit discriminates the type of the optical disc standard based on the intensity acquired by the reflected light acquiring unit and the discrimination result by the tracking discriminating unit.
The reproducing means reads out and reproduces the data recorded on the optical disc based on the determination result determined by the standard determining means.
The standard discriminating unit conforms to the first standard when the intensity acquired by the reflected light acquiring unit is greater than or equal to the first threshold and the tracking discriminating unit determines that the tracking control is successful. If the intensity acquired by the reflected light acquisition unit is greater than or equal to the first threshold value and the tracking determination unit determines that the tracking control is not successful, the optical disc conforms to the second standard. It is determined that the optical disc is compliant.

  Based on the result of discrimination by the standard discriminating unit, the reproducing unit sets the wavelength of the laser beam irradiated by the irradiating unit and the numerical aperture of the objective lens to a predetermined wavelength and numerical aperture previously associated with each type of standard. Can be set to play.

  The wavelength of the laser beam emitted by the irradiating means when being discriminated by the standard discriminating means can be the wavelength used when the reproducing means reads data from an optical disc conforming to the DVD (Digital Versatile Disk) standard.

  As the numerical aperture of the objective lens when discriminated by the standard discriminating unit, the numerical aperture used when the reproducing unit reads data from the optical disc conforming to the DVD standard can be used.

  The optical disk reproducing device is configured to determine the wavelength of the laser light irradiated by the irradiation unit and the numerical aperture of the objective lens based on the determination result determined by the standard determination unit, in advance corresponding to each standard type. A recording means for recording data on the optical disk by setting the wavelength and the numerical aperture may be further provided.

In order to achieve the above object, an optical disc reproducing method according to another aspect of the present invention includes a first standard and a second standard having an irradiation unit, a control unit, a reflected light acquisition unit, a standard determination unit, and a reproduction unit. An optical disc playback method executed by an optical disc playback apparatus that plays back an optical disc that complies with any of a plurality of standards including a control step, a reflected light acquisition step, a standard determination step, and a playback step.
The irradiation unit irradiates the optical disk with laser light having a predetermined wavelength.
In the control step, the control unit performs focus control for controlling the position of the objective lens so that the laser beam irradiated by the irradiation unit is focused on the optical disc.
In the reflected light acquisition step, the reflected light acquisition unit acquires the intensity of the reflected light from the optical disk of the laser light irradiated by the irradiation unit.
In the standard discriminating step, the standard discriminating unit discriminates the type of the optical disc standard based on the intensity acquired in the reflected light acquiring step.
In the reproduction step, the reproduction unit reads out and reproduces the data recorded on the optical disc based on the determination result determined in the standard determination step.
The standard determining step determines that the optical disc is an optical disc conforming to the first standard when the intensity acquired by the reflected light acquiring step is equal to or greater than the first threshold, and the intensity acquired by the reflected light acquiring step. Is equal to or larger than a second threshold value smaller than the first threshold value and smaller than the first threshold value, it is determined that the optical disk is an optical disk conforming to the second standard.

In order to achieve the above object, an optical disc reproducing method according to another aspect of the present invention includes an irradiation unit, a first control unit, a second control unit, a reflected light acquisition unit, a tracking determination unit, a standard determination unit, and a reproduction unit. An optical disc playback method executed by an optical disc playback apparatus for playing back an optical disc that complies with any one of a plurality of standards including the first standard and the second standard, and includes a first control step and a second control step. Control step, reflected light acquisition step, tracking discrimination step, standard discrimination step, and reproduction step.
The irradiation unit irradiates the optical disk with laser light having a predetermined wavelength.
In the first control step, the first control unit performs focus control for controlling the position of the objective lens so that the laser light emitted from the irradiation unit is focused on the optical disc.
In the second control step, the second control unit performs tracking control for controlling the laser beam irradiated by the irradiation unit to be applied to the track including the pit row on the recording surface of the optical disc.
In the reflected light acquisition step, the reflected light acquisition unit acquires the intensity of the reflected light from the optical disk of the laser light irradiated by the irradiation unit.
In the tracking determination step, the tracking determination unit determines whether or not the tracking control by the second control step is successful.
In the standard discriminating step, the standard discriminating unit discriminates the type of the optical disc standard based on the intensity acquired in the reflected light acquiring step and the discrimination result in the tracking discriminating step.
In the reproduction step, the reproduction unit reads out and reproduces the data recorded on the optical disc based on the determination result determined in the standard determination step.
In the standard determining step, when the intensity acquired in the reflected light acquiring step is equal to or higher than the first threshold and the tracking determining unit determines that the tracking control is successful, the optical disc conforms to the first standard. If it is determined that the optical disk is an optical disk, the intensity acquired in the reflected light acquisition step is equal to or greater than the first threshold, and the tracking determination step determines that the tracking control is not successful, the optical disk conforms to the second standard. It is determined that it is an optical disk.

In order to achieve the above object, a program according to another aspect of the present invention has irradiation means for irradiating an optical disc with laser light having a predetermined wavelength, and a plurality of standards including a first standard and a second standard. A computer that reproduces an optical disk that conforms to any one of the above functions as control means, reflected light acquisition means, standard determination means, and reproduction means.
The control means performs focus control for controlling the position of the objective lens so that the laser light emitted from the irradiation means is focused on the optical disk.
The reflected light acquisition means acquires the intensity of the reflected light from the optical disk of the laser light irradiated by the irradiation means.
The standard discriminating unit discriminates the type of the optical disc standard based on the intensity acquired by the reflected light acquiring unit.
The reproducing means reads out and reproduces the data recorded on the optical disc based on the determination result determined by the standard determining means.
The standard discriminating unit discriminates that the optical disc is an optical disc conforming to the first standard when the intensity acquired by the reflected light acquiring unit is equal to or larger than the first threshold, and the intensity acquired by the reflected light acquiring unit. Is equal to or larger than a second threshold value smaller than the first threshold value and smaller than the first threshold value, it is determined that the optical disk is an optical disk conforming to the second standard.

In order to achieve the above object, a program according to another aspect of the present invention has irradiation means for irradiating an optical disc with laser light having a predetermined wavelength, and a plurality of standards including a first standard and a second standard. A computer that reproduces an optical disc that conforms to any one of the above functions as first control means, second control means, reflected light acquisition means, tracking discrimination means, standard discrimination means, and playback means.
The first control means performs focus control for controlling the position of the objective lens so that the laser light emitted from the irradiation means is focused on the optical disk.
The second control means performs tracking control for controlling the laser light emitted by the irradiation means to be applied to a track including a pit row on the recording surface of the optical disc.
The reflected light acquisition means acquires the intensity of the reflected light from the optical disk of the laser light irradiated by the irradiation means.
The tracking control unit determines whether or not the tracking control by the second control unit is successful.
The standard discriminating unit discriminates the type of the optical disc standard based on the intensity acquired by the reflected light acquiring unit and the discrimination result by the tracking discriminating unit.
The reproducing means reads out and reproduces the data recorded on the optical disc based on the determination result determined by the standard determining means.
The standard discriminating unit conforms to the first standard when the intensity acquired by the reflected light acquiring unit is greater than or equal to the first threshold and the tracking discriminating unit determines that the tracking control is successful. If it is determined that the optical disk is an optical disk, the intensity acquired by the reflected light acquisition means is equal to or greater than the first threshold value, and the tracking determination means determines that the tracking control is not successful, the optical disk conforms to the second standard. It is determined that it is an optical disk.

The program of the present invention can be recorded on a computer-readable information storage medium such as a compact disk, flexible disk, hard disk, magneto-optical disk, digital video disk, magnetic tape, and semiconductor memory.
The above program can be distributed and sold via a computer communication network independently of the computer on which the program is executed. The information storage medium can be distributed and sold independently from the computer.

  According to the present invention, it is possible to provide an optical disc reproducing apparatus, an optical disc reproducing method, and a program suitable for discriminating and reproducing the type of the optical disc standard.

(Embodiment 1)
Hereinafter, the configuration of the optical disc playback apparatus 100 according to the present embodiment will be described.

  FIG. 1 is a diagram showing the configuration of the optical disc playback apparatus 100. An optical disc playback apparatus 100 includes an optical disc drive 101, an input unit 102, an output unit 103, an I / F 104, a storage unit 105, a ROM (Read Only Memory) 106, a RAM (Random Access Memory) 107, a control unit 108, and a system bus. 109.

  FIG. 2 is a diagram showing the configuration of the optical disk drive 101 (viewed from a direction perpendicular to the rotation axis of the optical disk). The optical disc drive 101 includes an optical pickup unit 201. Further, the optical pickup unit 201 includes a laser light source 202, an objective lens 203, and a photodetector 204.

The optical disc drive 101 is a drive device that can play back optical discs that conform to the four standards of BD, HDDVD, DVD, and CD, and can read data from these optical discs. When an optical disc is loaded into the optical disc drive 101, the optical disc drive 101 rotates the optical disc with a motor (not shown) under the control of the control unit 108, and has a predetermined wavelength from the laser light source 202 toward the data recording surface of the optical disc. Irradiate with laser light. Typically, the wavelength of this laser beam is about 650 nanometers (nm), the numerical aperture of the objective lens 203 is about 0.6, and the wavelength and aperture used when reading data from a DVD standard optical disc and reproducing it. It is about the same as the number. The photodetector 204 of the optical disc drive 101 collects the reflected light of the irradiated laser beam from the optical disc and converts it into data. The control unit 108 determines the standard type of the optical disc mounted in the optical disc drive 101 based on the signal intensity of the reflected light of the laser light acquired by the photodetector 204. Details of this processing (hereinafter referred to as “media discrimination processing”) performed by the control unit 108 will be described later.
The control unit 108 controls the optical disc drive 101 to switch to a predetermined wavelength and a predetermined numerical aperture according to the type of the standard determined in the media determination process, and irradiates the laser light from the laser light source 202. The reflected light is condensed and the data recorded on the optical disk is read and reproduced. The wavelength of the laser beam used for the reproduction processing and the numerical aperture of the objective lens are typically about 405 nm and the numerical aperture of about 0.85 when the optical disc standard type is “BD”. . In the case of “HDDVD”, the wavelength of the laser beam is about 405 nm and the numerical aperture is about 0.65. In the case of “DVD”, the wavelength of the laser beam is about 650 nm and the numerical aperture is about 0.6. In the case of “CD”, the wavelength of the laser beam is about 780 nm, and the numerical aperture is about 0.45. Predetermined values such as the wavelength and numerical aperture of the laser beam used for the reproduction process are stored in advance in the ROM 106 or the like. Further, it may be realized by the control unit 108 executing an operation program in which predetermined values such as the wavelength and numerical aperture of the laser beam used for the reproduction operation are stored in advance.

  Thus, since the optical disc drive 101 uses one type of laser light and one type of numerical aperture in order to discriminate the type of optical disc standard, it is not necessary to switch the laser light. As a result, the optical disc drive 101 of the present embodiment can perform media discrimination faster than before.

  The input unit 102 includes operation keys, operation buttons (both not shown), and the like. The input unit 102 generates an input signal based on an instruction input (for example, an instruction input for starting reproduction) or a data input input by a user using an operation key or the like, and inputs the input signal to the control unit 108. Thereby, the user can perform a desired operation instruction. Note that other input devices such as operation switches and voice input devices may be provided instead of or in addition to the operation keys and operation buttons.

  The output unit 103 is connected to a display device such as an LCD (Liquid Crystal Display). The output unit 103 processes the image data read from the optical disc by the optical disc drive 101 under the control of the control unit 108 using an image arithmetic processor (not shown) included in the control unit 108 or the output unit 103, and then outputs the output unit 103. Is recorded in an output buffer (not shown). The image information recorded in the output buffer is converted into an image signal at a predetermined synchronization timing and output to a display device connected to the output unit 103. Thereby, video data can be reproduced. Note that the display device is not limited to the above-described one, and an arbitrarily modified embodiment can be adopted.

  The output unit 103 is connected to a sound output device such as a speaker. The output unit 103 demodulates the audio data read from the optical disc by the optical disc drive 101 under the control of the control unit 108 by digital / analog conversion using a D / A converter (not shown) provided in the output unit 103, and then demodulates the audio data. Output to the output device. Thereby, it is possible to reproduce the audio data.

  The I / F 104 is an interface for inputting / outputting data by connecting to an external recording medium such as a memory card. For example, the optical disc playback apparatus 100 and an external device can be connected by USB (Universal Serial Bus) connection, and data can be input / output with the external device.

  The storage unit 105 includes a storage device such as a flash memory or a hard disk drive, and stores various data under the control of the control unit 108.

  The ROM 106 stores an operating system (OS), programs, and various data necessary for operation control of the entire optical disc playback apparatus 100.

  The RAM 107 is for temporarily storing data and programs, and holds data read from the optical disc by the optical disc drive 101. Further, the control unit 108 provides a variable area in the RAM 107 and performs an operation on a value stored in the variable, or stores a value stored in the RAM 107 in a register and then performs an operation on the register. Then, processing such as writing back the calculation result to the RAM 107 is performed.

  The control unit 108 is composed of a CPU (Central Processing Unit), controls the overall operation of the optical disc playback apparatus 100, is connected to each component, and exchanges control signals and data. The control unit 108 uses an arithmetic logic unit (ALU) (not shown), such as addition / subtraction / multiplication / division, etc. for a storage area that can be accessed at a high speed called a register (not shown), logical sum, logical product, Logical operations such as logical negation, bit operations such as bit sum, bit product, bit inversion, bit shift, and bit rotation can be performed. In addition, the control unit 108 is configured to perform high-speed saturation calculations such as addition / subtraction / multiplication / division for multimedia processing, vector calculations such as trigonometric functions, and the like. Alternatively, it may be realized with a coprocessor.

  For example, the control unit 108 performs media determination processing described later to determine the type of standard for the optical disc loaded in the optical disc drive 101. Further, the control unit 108 performs reproduction by switching to a predetermined wavelength of the laser beam and a predetermined numerical aperture of the objective lens based on the determination result by the medium determination process. As a result, the optical disc playback apparatus 100 can play back optical discs of a plurality of standards. For example, the control unit 108 controls the optical disc drive 101 to read and decode video data (or audio data, etc.) stored in an optical disc of the DVD standard, HDDVD standard, BD standard, or CD standard, and a video signal (or Video (or audio) is output. The control unit 108 reproduces the program for reproduction stored in advance in the ROM 106 or the like by reading and executing the program at any time.

  A system bus 109 is a transmission path for transferring commands and data to and from the optical disk drive 101, the input unit 102, the output unit 103, the I / F unit 104, the storage unit 105, the ROM 106, the RAM 107, and the control unit 108. It is.

  Next, media discrimination processing performed by the control unit 108 will be described. In the present embodiment, the control unit 108 determines whether or not the intensity of the reflected light is the first threshold value, the second threshold value, the third threshold value, or the fourth threshold value. The type of the standard used for the is determined. Here, the magnitude of each threshold value is a value obtained in advance that satisfies the magnitude relationship of “fourth threshold value <third threshold value <second threshold value <first threshold value”. In the present embodiment, four standards of DVD, HDDVD, CD, and BD are used as discriminating standards. However, the types of standards to be determined are not limited to these combinations. This will be described in detail below.

  FIG. 3 is a flowchart for explaining the media discrimination processing.

  First, the control unit 108 controls the optical disc drive 101 to perform focus servo control (step S301). The focus servo control is control for adjusting the output of the laser beam and the focus of the recording surface of the optical disc. The wavelength of the laser beam and the numerical aperture of the objective lens used in the focus servo control are the wavelength and the numerical aperture used when data is read out from the DVD standard optical disk and reproduced. Specifically, the control unit 108 controls the optical disc drive 101 to irradiate the recording surface of the optical disc with laser light having a predetermined wavelength, and applies an electric signal (current) indicating reflected light obtained by the photodetector 204 to the focus coil. Based on the magnitude of the electric signal, the optical pickup unit 201 is adjusted by moving it in a direction perpendicular to the recording surface of the optical disc (vertical direction in FIG. 2).

  For example, the focus servo control is performed using an astigmatism method or the like in which the spot shape of reflected light detected by the photodetector 204 changes when the focus of the laser beam is deviated. That is, when the laser beam is in focus, the spot shape of the reflected light detected by the photodetector 204 is a perfect circle, and when the laser beam is defocused forward or backward from the recording surface, the spot shape is an ellipse. Become. The control unit 108 controls the position of the optical pickup unit 201 so that the spot shape of the reflected light detected by the photodetector 204 becomes a perfect circle.

  Next, the control unit 108 acquires the intensity of the reflected light of the laser light (step S302), and determines whether or not the acquired intensity of the reflected light is equal to or higher than the first threshold (step S303).

  When it is determined that the acquired reflected light intensity is greater than or equal to the first threshold (step S303; YES), the control unit 108 determines that the optical disc loaded in the optical disc drive 101 is a DVD (step S304).

  On the other hand, when it is determined that the acquired reflected light intensity is less than the first threshold (step S303; NO), the control unit 108 determines whether the reflected light intensity is equal to or higher than the second threshold ( Step S305).

  When it is determined that the acquired reflected light intensity is greater than or equal to the second threshold (step S305; YES), the control unit 108 determines that the optical disc loaded in the optical disc drive 101 is an HDDVD (step S306).

  On the other hand, when it is determined that the acquired reflected light intensity is less than the second threshold (step S305; NO), the control unit 108 determines whether or not the reflected light intensity is equal to or greater than the third threshold ( Step S307).

  When it is determined that the acquired reflected light intensity is greater than or equal to the third threshold (step S307; YES), the control unit 108 determines that the optical disc loaded in the optical disc drive 101 is a CD (step S308).

  On the other hand, when it is determined that the acquired reflected light intensity is less than the third threshold (step S307; NO), the control unit 108 determines whether or not the reflected light intensity is equal to or greater than the fourth threshold ( Step S309).

  When it is determined that the acquired reflected light intensity is greater than or equal to the fourth threshold (step S309; YES), the control unit 108 determines that the optical disc loaded in the optical disc drive 101 is a BD (step S310).

  On the other hand, when it is determined that the acquired reflected light intensity is less than the fourth threshold (step S309; NO), the control unit 108 determines that no readable optical disc is loaded in the optical disc drive 101 (step S309; NO). Step S311). When an optical disc itself is not loaded or an information recording medium recorded in another standard that is not a predetermined standard is loaded, it is determined that a readable optical disc is not loaded.

  The correspondence between each threshold value and the determination result is summarized as shown in FIG. That is, the control unit 108 determines “DVD” if the intensity of the reflected light of the irradiated laser light from the recording surface of the optical disc is equal to or greater than the first threshold, and is equal to or greater than the second threshold and less than the first threshold. If it exists, it is determined as “HDDVD”, if it is not less than the third threshold and less than the second threshold, it is determined as “CD”, and if it is not less than the fourth threshold and less than the third threshold, it is determined as “BD”. If it is less than the threshold of 4, “no disk” is determined.

  The control unit 108 controls the optical disc drive 101, sets the wavelength of the laser beam, the numerical aperture of the objective lens, and the like based on the discrimination result obtained by performing the media discrimination processing, and reads data from the optical disc. Set to be able to. For example, when an instruction input for reproducing an optical disk is received from a user, the control unit 108 reads and reproduces data from the optical disk.

  As described above, according to the present embodiment, the optical disc reproducing apparatus 100 does not need to switch the laser beam to discriminate the type of the optical disc standard, and can discriminate the standard faster and more easily than in the past. it can. Then, the optical disc playback apparatus 100 can play back optical discs of a plurality of standards based on the determination result. For example, as in the past, focus servo control performed using a laser beam capable of reading BD, focus servo control performed using a laser beam capable of reading HDDVD, and focus servo performed using a laser beam capable of reading DVD There is no need to discriminate between the control and focus servo control using a laser beam capable of reading a CD.

(Embodiment 2)
Next, another embodiment of the present invention will be described. In the present embodiment, the control unit 108 determines the type of the optical disc standard based on whether the intensity of the reflected light is equal to or higher than the first threshold, the second threshold, or the third threshold. . Here, the size of each threshold is a value obtained in advance that satisfies the magnitude relationship of “third threshold <second threshold <first threshold”. The control unit 108 is different from the above-described embodiment in that the standard is determined by performing tracking servo control in addition to focus servo control. In the present embodiment, four types of DVD, HDDVD, CD, and BD are used as the types of standards to be discriminated. However, the types of standards to be determined are not limited to these combinations. This will be described in detail below.

  FIG. 5 is a flowchart for explaining the media discrimination processing performed by the control unit 108 of the present embodiment.

  First, the control unit 108 controls the optical disc drive 101 to perform focus servo control (step S501). The wavelength of the laser beam and the numerical aperture of the objective lens used in the focus servo control are the wavelength and the numerical aperture used when data is read out from the DVD standard optical disk and reproduced.

  Next, the control unit 108 acquires the reflected light intensity of the laser light (step S502), and determines whether or not the acquired reflected light intensity is equal to or higher than the first threshold (step S503).

  When it is determined that the acquired reflected light intensity is greater than or equal to the first threshold (step S503; YES), the control unit 108 controls the optical disc drive 101 to perform tracking servo control (step S504). The tracking servo control is a control for accurately tracing the pit track carved on the recording surface of the optical disc so that the laser beam is correctly irradiated to the pit. Specifically, the control unit 108 controls the optical disc drive 101 to irradiate a recording surface of the optical disc with a laser beam having a predetermined wavelength, and uses an electrical signal (current) indicating reflected light obtained by the photodetector 204 as a tracking coil. Based on the magnitude of the electric signal, the optical pickup unit 201 is adjusted by moving it in the direction parallel to the recording surface of the optical disc (the horizontal direction in FIG. 2).

  When tracking servo control is performed and tracking is successful (step S505; YES), the control unit 108 determines that the optical disc loaded in the optical disc drive 101 is a DVD (step S506). In other words, in this embodiment, the wavelength of the laser beam and the numerical aperture of the objective lens used in the media discrimination process are values used when reading and reproducing data from the DVD. Can be determined.

  On the other hand, when the tracking is not successful (step S505; NO), the control unit 108 determines that the optical disc loaded in the optical disc drive 101 is an HDDVD (step S507). In this embodiment, the numerical aperture used for reading from DVD and HDDVD is the same, and the wavelength of the laser beam is different. Therefore, even if the reflected light intensity when performing the focus servo control is equal to or higher than the first threshold, tracking is performed. It is possible to discriminate between DVD and HDDVD based on whether or not the recording has succeeded.

  Returning to step S503, when it is determined that the acquired reflected light intensity is not equal to or greater than the first threshold (step S503; NO), the control unit 108 determines whether the reflected light intensity is equal to or greater than the second threshold. (Step S508).

  When it is determined that the acquired reflected light intensity is greater than or equal to the second threshold (step S508; YES), the control unit 108 determines that the optical disk loaded in the optical disk drive 101 is a CD (step S509).

  On the other hand, when it is determined that the acquired reflected light intensity is less than the second threshold (step S508; NO), the control unit 108 determines whether or not the reflected light intensity is equal to or greater than the third threshold ( Step S510).

  If it is determined that the acquired reflected light intensity is greater than or equal to the third threshold (step S510; YES), the control unit 108 determines that the optical disc loaded in the optical disc drive 101 is a BD (step S511).

  On the other hand, when it is determined that the acquired reflected light intensity is less than the third threshold value (step S510; NO), the control unit 108 determines that no readable optical disc is loaded in the optical disc drive 101 ( Step S512). When an optical disk itself is not loaded or an information recording medium recorded in another standard that is not a predetermined standard is loaded, it is determined that a readable optical disk is not loaded.

  The correspondence between each threshold value and the determination result is summarized as shown in FIG. That is, the control unit 108 determines “DVD or HDDVD” if the intensity of the reflected laser light from the recording surface of the optical disc is equal to or higher than the first threshold value. Further, the control unit 108 determines that it is “DVD” if the tracking is successful, and determines that it is “HDDVD” if it is not successful. The control unit 108 determines “CD” if the reflected light intensity is greater than or equal to the second threshold and less than the first threshold, and determines “BD” if the reflected light intensity is greater than or equal to the third threshold and less than the second threshold. If it is less than the third threshold, it is determined that there is no disk.

  The control unit 108 controls the optical disc drive 101, sets the wavelength of the laser beam, the numerical aperture of the objective lens, and the like based on the discrimination result obtained by performing the media discrimination processing, and reads data from the optical disc. Set to be able to. For example, when an instruction input for reproducing an optical disk is received from a user, the control unit 108 reads and reproduces data from the optical disk.

  As described above, according to the present embodiment, the optical disc reproducing apparatus 100 does not need to switch the laser beam in order to discriminate the type of the optical disc, and can discriminate the standard faster and more easily than in the past. Then, the optical disc playback apparatus 100 can play back optical discs of a plurality of standards based on the determination result. In addition, the number of thresholds used in the media discrimination process is small, and the influence of the obtained reflected light intensity error and the performance error of the photodetector 204 on the judgment result can be reduced, so that the judgment accuracy is increased.

  The present invention is not limited to the above-described embodiments, and various modifications and applications are possible.

  In the above-described embodiments, the types of optical discs of the BD, HDDVD, DVD, and CD standards are determined. However, an embodiment using any combination including a DVD can also be adopted. For example, it can be configured to discriminate between optical discs of three standards of BD, DVD, and CD, or discriminate optical discs of three standards of HDDVD, DVD, and CD.

  In the above-described embodiment, values used when reading and reproducing data from a DVD are employed as the wavelength of the laser beam used for the media discrimination process and the numerical aperture of the objective lens, but are not limited thereto. For example, a modification using other wavelengths and numerical apertures capable of discriminating a plurality of predetermined standards may be employed.

  Typically, the control unit 108 of the optical disc playback apparatus 100 performs the above-described media determination processing when it is detected that an information recording medium is loaded in the optical disc drive 101. The timing for performing the media determination processing is as follows. Is optional.

  According to the present invention, it is possible to provide an optical disc playback apparatus that can easily discriminate media in a short time.

  The optical disc reproducing apparatus 100 may further include a recording unit that not only reproduces an optical disc of a predetermined standard such as BD, HDDVD, DVD, and CD, but also writes data on the optical disc according to each standard. For example, when writing data on an optical disc, the type of the standard of the optical disc to be written to is discriminated, and the wavelength, numerical aperture, etc. of the laser beam used for the writing process are set to a predetermined value based on the discrimination result. You can also. Predetermined values such as the wavelength and numerical aperture of the laser beam used for the writing process are stored in advance in the ROM 106 or the like. Alternatively, it may be realized by the control unit 108 executing an operation program in which predetermined values such as the wavelength and numerical aperture of laser light used for the writing process are stored in advance. As a result, it is possible to provide an optical disc recording apparatus that can discriminate media easily in a short time.

  As described above, according to the present invention, it is possible to provide an optical disc playback apparatus, an optical disc playback method, and a program suitable for discriminating and playing back the types of optical disc standards.

It is a figure for demonstrating the structure of an optical disk reproducing | regenerating apparatus. It is a figure for demonstrating the structure of an optical disk drive, and is the figure seen from the direction perpendicular | vertical to the rotating shaft of an optical disk. It is a flowchart for demonstrating a media discrimination | determination process. It is a figure which shows the correspondence of reflected light intensity and a discrimination | determination result. 10 is a flowchart for explaining a media determination process according to the second embodiment. It is a figure which shows the correspondence of the reflected light intensity of Embodiment 2, and a discrimination | determination result.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Optical disk reproducing | regenerating apparatus 101 Optical disk drive 102 Input part 103 Output part 104 I / F
105 Storage unit 106 ROM
107 RAM
108 Control Unit 109 System Bus 201 Optical Pickup Unit 202 Laser Light Source 203 Objective Lens 204 Photodetector

Claims (10)

An optical disc playback apparatus for playing back an optical disc compliant with any one of a plurality of standards including a first standard and a second standard,
Irradiating means for irradiating the optical disk with laser light of a predetermined wavelength;
Control means for performing focus control for controlling the position of the objective lens so that the laser light emitted by the irradiation means is focused on the optical disc;
Reflected light acquisition means for acquiring the intensity of the reflected light from the optical disc of the laser light irradiated by the irradiation means;
Standard discriminating means for discriminating the type of standard of the optical disc based on the intensity obtained by the reflected light obtaining means;
Based on the discrimination result discriminated by the standard discriminating means, the reproducing means for reading and reproducing the data recorded on the optical disc;
With
The standard discriminating unit discriminates that the optical disc is an optical disc conforming to the first standard when the intensity acquired by the reflected light acquiring unit is equal to or higher than a first threshold, and the reflected light acquiring unit When the acquired intensity is equal to or greater than a second threshold value that is smaller than the first threshold value and less than the first threshold value, it is determined that the optical disc is an optical disc that conforms to the second standard. An optical disc reproducing apparatus characterized by the above. An optical disc playback apparatus for playing back an optical disc compliant with any one of a plurality of standards including a first standard and a second standard,
Irradiating means for irradiating the optical disk with laser light of a predetermined wavelength;
First control means for performing focus control for controlling the position of the objective lens so that the laser light emitted by the irradiation means is focused on the optical disc;
Second control means for performing tracking control for controlling the laser light emitted by the irradiation means to be applied to a track including a pit row on the recording surface of the optical disc;
Reflected light acquisition means for acquiring the intensity of the reflected light from the optical disc of the laser light irradiated by the irradiation means;
Tracking determination means for determining whether or not the tracking control by the second control means is successful;
Standard discriminating means for discriminating the type of the standard of the optical disc based on the intensity obtained by the reflected light obtaining means and the discrimination result by the tracking discriminating means;
Based on the discrimination result discriminated by the standard discriminating means, the reproducing means for reading and reproducing the data recorded on the optical disc;
With
If the intensity acquired by the reflected light acquisition unit is greater than or equal to a first threshold value and the tracking determination unit determines that tracking control has been successful, the standard determination unit determines that the optical disc is the first optical disc. When it is determined that the optical disk conforms to a standard, the intensity acquired by the reflected light acquisition unit is equal to or greater than a first threshold, and the tracking determination unit determines that tracking control is not successful, the optical disc Disc is determined to be an optical disc conforming to the second standard. The reproducing means is a predetermined number in which the wavelength of the laser beam irradiated by the irradiating means and the numerical aperture of the objective lens are associated in advance for each standard type based on the determination result by the standard determining means. The optical disk reproducing apparatus according to claim 1 or 2, wherein reproduction is performed with the wavelength and numerical aperture set to each other. The wavelength of the laser beam emitted by the irradiating unit when discriminated by the standard discriminating unit is a wavelength used when the reproducing unit reads data from an optical disc compliant with the DVD (Digital Versatile Disk) standard. The optical disk reproducing apparatus according to claim 1, wherein 5. The numerical aperture of the objective lens determined by the standard determining unit is a numerical aperture used when the reproducing unit reads data from an optical disc compliant with the DVD standard. Optical disk playback device. Based on the discrimination result discriminated by the standard discriminating unit, the wavelength of the laser beam irradiated by the irradiating unit, and the numerical aperture of the objective lens, a predetermined wavelength and a predetermined wavelength associated with each type of standard in advance 3. The optical disk reproducing apparatus according to claim 1, further comprising recording means for recording data on the optical disk by setting the numerical aperture. Executed by an optical disk reproducing apparatus that reproduces an optical disk that conforms to one of a plurality of standards including the first standard and the second standard, and includes an irradiation unit, a control unit, a reflected light acquisition unit, a standard determination unit, and a reproduction unit An optical disc playback method, comprising:
The irradiation unit irradiates the optical disk with laser light having a predetermined wavelength,
A control step in which the control unit performs focus control for controlling a position of an objective lens so that the laser beam irradiated by the irradiation unit is focused on the optical disc;
The reflected light acquisition unit acquires the intensity of reflected light from the optical disk of the laser light irradiated by the irradiation unit;
A standard determining step for determining a standard type of the optical disc based on the intensity acquired by the reflected light acquiring step;
The reproduction unit reads out and reproduces the data recorded on the optical disc based on the determination result determined by the standard determination step;
With
The standard determining step determines that the optical disc is an optical disc conforming to the first standard when the intensity acquired in the reflected light acquiring step is equal to or greater than a first threshold, and the reflected light acquiring step When the acquired intensity is equal to or greater than a second threshold value that is smaller than the first threshold value and less than the first threshold value, it is determined that the optical disc is an optical disc that conforms to the second standard. An optical disc reproducing method characterized by the above. Any of a plurality of standards including a first standard and a second standard having an irradiation unit, a first control unit, a second control unit, a reflected light acquisition unit, a tracking determination unit, a standard determination unit, and a reproduction unit An optical disc reproducing method executed by an optical disc reproducing apparatus for reproducing an optical disc compliant with
The irradiation unit irradiates the optical disk with laser light having a predetermined wavelength,
A first control step in which the first control unit performs focus control for controlling the position of the objective lens so that the laser beam irradiated by the irradiation unit is focused on the optical disc;
A second control step in which the second control unit performs tracking control for controlling the laser beam irradiated by the irradiation unit to be applied to a track including a pit row on the recording surface of the optical disc;
The reflected light acquisition unit acquires the intensity of reflected light from the optical disk of the laser light irradiated by the irradiation unit;
A tracking determination step in which the tracking determination unit determines whether or not the tracking control by the second control step is successful;
A standard discriminating step in which the standard discriminating unit discriminates the type of the standard of the optical disc based on the intensity obtained in the reflected light obtaining step and the discrimination result in the tracking discriminating step;
The reproduction unit reads out and reproduces the data recorded on the optical disc based on the determination result determined by the standard determination step;
With
In the standard determining step, when the intensity acquired in the reflected light acquiring step is greater than or equal to a first threshold value and the tracking determining means determines that the tracking control is successful, the optical disc is the first optical disc. If it is determined that the optical disk conforms to a standard, the intensity acquired in the reflected light acquisition step is equal to or greater than a first threshold, and the tracking determination step determines that tracking control is not successful, the optical disk Disc is determined to be an optical disc conforming to the second standard. A computer that has irradiation means for irradiating a laser beam of a predetermined wavelength onto an optical disk and reproduces an optical disk that conforms to any of a plurality of standards including the first standard and the second standard,
Control means for performing focus control for controlling the position of the objective lens so that the laser light irradiated by the irradiation means is focused on the optical disc;
Reflected light acquisition means for acquiring the intensity of reflected light from the optical disk of the laser light irradiated by the irradiation means;
A standard discriminating unit for discriminating the type of the standard of the optical disc based on the intensity acquired by the reflected light acquiring unit;
Reproducing means for reading out and reproducing the data recorded on the optical disc based on the determination result determined by the standard determining means,
Function as
The standard discriminating unit discriminates that the optical disc is an optical disc conforming to the first standard when the intensity acquired by the reflected light acquiring unit is equal to or higher than a first threshold, and the reflected light acquiring unit When the acquired intensity is equal to or greater than a second threshold value that is smaller than the first threshold value and less than the first threshold value, it is determined that the optical disc is an optical disc that conforms to the second standard. A program characterized by A computer that has irradiation means for irradiating a laser beam of a predetermined wavelength onto an optical disk and reproduces an optical disk that conforms to any of a plurality of standards including the first standard and the second standard,
First control means for performing focus control for controlling the position of the objective lens so that the laser light emitted by the irradiation means is focused on the optical disc;
Second control means for performing tracking control for controlling the laser light emitted by the irradiation means to be applied to a track including a pit row on the recording surface of the optical disc;
Reflected light acquisition means for acquiring the intensity of reflected light from the optical disk of the laser light irradiated by the irradiation means;
Tracking determination means for determining whether or not tracking control by the second control means is successful;
Standard discriminating means for discriminating the type of the standard of the optical disc based on the intensity obtained by the reflected light obtaining means and the discrimination result by the tracking discriminating means,
Reproducing means for reading out and reproducing the data recorded on the optical disc based on the determination result determined by the standard determining means,
Function as
If the intensity acquired by the reflected light acquisition unit is greater than or equal to a first threshold value and the tracking determination unit determines that tracking control has been successful, the standard determination unit determines that the optical disc is the first optical disc. When it is determined that the optical disk conforms to a standard, the intensity acquired by the reflected light acquisition unit is equal to or greater than a first threshold, and the tracking determination unit determines that tracking control is not successful, the optical disc Is determined to be an optical disc compliant with the second standard.

Images