JPH10198969A - Objective lens driving device, and information processor provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely perform the information processing with respect to an optical information recording medium corresponding to a discriminated objective lens by changing over the objective lenses while selecting the objective lens from among objective lenses of different types and making the kind of the objective lens selected in the optical of a laser beam discriminable. SOLUTION: When an objective lens 35 is selected from among two pieces of objective lenses 34, 35, a reflection element 92 is positioned opposite to a detector 100. Consequently, the emitted light of the light emitting part of the detector 100 is reflected on the reflection element 92 to be returned and the light is received by the light receiving part of the detector 100. Since the detector 100 generates a detection signal by the receiving of light of this light receiving part, the selecting of the objective lens 35 is detected. Moreover, when the objective lent 34 is selected, since the reflection element 92 is not present at the counter position of the detector 100, the emitted light of the light emitting part of the detector 100 is not received by the light receiving part of the detector 100. Thus since the detection signal is not generated from the detector 100, it is made detectable that the objective lens 34 is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an optical information recording medium,
For example, the present invention relates to an information processing device such as an optical disk device that at least reproduces information recorded on an optical disk and an objective lens driving device mounted on the information processing device. The present invention relates to an information processing apparatus capable of identifying the type of the switched objective lens and an objective lens driving apparatus mounted on the information processing apparatus.

[0002]

2. Description of the Related Art With the development of various optical information recording media, information processing devices such as optical disk devices for reproducing information recorded on these media have been actively developed. This information processing device is already a CD (compact disk)
Or an optical disk device for a CD-ROM (read-only memory using a compact disk). In addition, an optical disk device not only for reproduction but also for recording is being developed. In particular, recording methods such as a magneto-optical recording method and a phase change recording method are known. The details of many of these methods are currently defined by standards.

In recent years, a DVD (Digital Video Disk) has emerged as a high-density recording type optical disk aiming at further improvement in recording density, and research and development of an optical disk device for this high-density recording type optical disk have been carried out. It is becoming active. In such an optical disk, pits as information recording units are formed smaller than in the case of a conventional CD in order to realize a high density, and it is required for an optical disk device that the pit search be performed with high accuracy. Is done.
Furthermore, a high-density recording type optical disc has a different substrate thickness from that of a conventional CD. In this optical disc apparatus, the wavelength of a laser beam for searching for pits is shorter, and the numerical aperture NA (Numerical Aperture) of the objective lens is smaller. By making the diameter larger, the diameter of the beam spot formed on the optical disk is reduced.

[0004] When various improvements are made to an optical disk device in order to cope with a newly appearing optical disk as described above, there is a problem that it is difficult for the optical disk device to record / reproduce an optical disk in accordance with a conventional standard. For the user, there is a disadvantage that an optical disk device corresponding to the type of the optical disk must be prepared.

As a system for solving such a problem, there is a system in which a plurality of optical heads having different focal lengths are arranged on the same optical disk device as disclosed in US Pat. No. 5,235,581. In this optical disk device, two optical heads are arranged so as to be independently driven for tracking, and are also capable of reproducing or recording a conventional optical disk such as a CD.

[0006]

However, in such a system, two optical heads are arranged symmetrically with respect to the center of the optical disk so as to face each other, and the two optical heads are mounted on the optical disk device. It is said that they cannot be placed adjacent to each other. Therefore, in the optical disk device of such a system, an optical disk (for example, a CD-ROM, a magneto-optical disk, or the like) used in a cartridge (caddy) having a window portion is used.
There is a problem that neither of the two objective lenses can be positioned below the window opening having a limited area. Also, with the spread of optical disk devices, there is a great demand for lowering the price of the device, and the need for two optical heads
There is a problem that it becomes an obstacle to such a request.

From such a viewpoint, two or more types of objective lenses of different types are arranged in one optical head, and the objective lens drive has a structure capable of switching these objective lenses in one optical head. The advent of devices is desired. Further, in such a structure, it is required to reliably identify the type of the objective lens which is switched and selected.

The present invention has been made in view of the above-mentioned circumstances, and has as its object the purpose of, for example, using a conventional type of objective lens between various objective lenses corresponding to various optical information recording media. The objective lens can be selectively switched between the objective lens of the type corresponding to the optical information recording medium being used and the objective lens of the type corresponding to the newly emerging optical information recording medium, and this switching enables It is an object of the present invention to provide an objective lens driving device capable of identifying the type of the selected objective lens and an information processing device provided with the driving device.

[0009]

In order to achieve the above object, an objective lens driving device according to the present invention operates an objective lens for irradiating an optical information recording medium with a light beam in an optical path of the light beam, An objective lens driving device that focuses a light beam on a track on which information on the optical information recording medium is recorded to bring it into a focused state, and causes the light beam in the focused state to follow to bring it into a focused state. A first objective lens for condensing a light beam suitable for the first optical information recording medium; and a light suitable for a second optical information recording medium of a type different from the first optical information recording medium. A second objective lens for condensing a beam, a lens holder for holding the first and second objective lenses, a holding center of the first objective lens by the lens holder, and the second objective lens It has a rotation axis at a position shifted from the holding center and along the optical axis direction of the first and second objective lenses, and is rotatable around the rotation axis and movable in the rotation axis direction. By supporting the lens holder, a lens holder support that supports any one of the first and second objective lenses in the optical path of the light beam and movably in the optical axis direction, Via the lens holder, by the lens holder support, in a state where the first objective lens is arranged in the optical path of the light beam,
The first objective lens is controlled to the tracking state by slightly rotating the lens holder, and the second objective lens is rotated by driving the lens holder to replace the first objective lens. A state in which the first objective lens is arranged in the optical path of the light beam by the first objective lens driving means arranged in the optical path of the light beam and the lens holder support via the lens holder. A second objective lens driving means for finely moving the lens holder along the optical axis of the first objective lens to control the first objective lens in the in-focus state, and via the lens holder In a state in which the second objective lens is disposed in the optical path of the light beam by the lens holder support, the lens holder is slightly rotated to rotate the second objective lens. A third objective lens driving unit that controls the lens to be in the tracking state, and drives the lens holder to rotate and replace the second objective lens with the first objective lens in the optical path of the light beam. Via the lens holder, by the lens holder support, in a state where the second objective lens is disposed in the optical path of the light beam, the lens holder is moved along the optical axis of the second objective lens. Fourth objective lens driving means for finely moving along the second objective lens to control the second objective lens in the in-focus state, and is disposed at a predetermined position of the lens holder,
A reflecting means for reflecting light, and, when the first objective lens is arranged in an optical path of the light beam, arranged at a predetermined position on the lens holder support opposed to the reflecting means, and emits light. And detecting means for detecting the reception of the reflected light generated by the light emission from the reflecting means.

Further, an information processing apparatus according to the present invention includes an objective lens driving device having the above-described configuration, and includes, based on a detection result by the detection means, one of the first and second objective lenses. Identification means for identifying an objective lens arranged in the optical path of the light beam; and, of the first and second objective lenses, a light beam is emitted by one of the objective lenses arranged in the optical path of the light beam. A tracking control circuit that causes the first objective lens driving unit or the third objective lens driving unit to perform tracking control of the one objective lens based on the collected reflected light from the optical information recording medium; Based on the reflected light from the optical information recording medium in which the light beam is condensed by one of the first and second objective lenses arranged in the optical path of the light beam. A focus control circuit for causing the second objective lens driving means or the fourth objective lens driving means to perform focus control of the one objective lens; and an objective arranged in the optical path of the light beam by the identification means. When the lens is identified as the first objective lens, a tracking control circuit controls the first objective lens driving unit to perform tracking control of the one objective lens, and a focus control circuit controls the second objective lens. Causing the lens driving unit to perform focus control of the one objective lens, and when the identification unit identifies the objective lens arranged in the optical path of the light beam as the second objective lens, The tracking of the one objective lens to the third objective lens driving means instead of the one objective lens driving means Comprising a switching means for instead of the second objective lens driving means together to perform the control performed focus control of the one of the objective lens in the fourth objective lens driving means.

In the objective lens driving device having such a configuration and the information processing apparatus having the objective lens driving device, the lens holder for holding the first objective lens and the second objective lens of different types is a lens holder. The first objective lens is brought into a tracking state by being pivotally supported by the support so as to be able to rotate around the rotation axis and to be movable in the direction of the rotation axis, and being slightly rotated by the first objective lens driving means. The second objective lens is arranged in the optical path of the light beam in place of the first objective lens by being controlled and rotated and driven, and the second objective lens is driven by the second objective lens driving means to the optical axis of the first objective lens. The first objective lens is controlled to be in focus by being finely moved along.

Further, the lens holder is slightly rotated by the third objective lens driving means so that the second objective lens is controlled to the in-tracking state and is driven to rotate so that the second objective lens is moved to the second objective lens. Alternatively, the first objective lens is arranged in the optical path of the light beam, and is finely moved along the optical axis of the second objective lens by the fourth objective lens driving means, so that the second objective lens is in a focused state. Is controlled.

Further, when the first objective lens is disposed in the optical path of the light beam instead of the second objective lens by the first objective lens driving means, the reflecting means and the detecting means face each other. As a result, the reflected light from the reflecting means is detected by the detecting means, and it is identified that the first objective lens is disposed in the optical path of the light beam. Further, when the second objective lens is disposed in the optical path of the light beam instead of the first objective lens by the third objective lens driving means, the reflection means and the detection means do not face each other. Is not detected by the detecting means, it is identified that the second objective lens is disposed in the optical path of the light beam instead of the first objective lens.

As described above, the objective lens driving means according to the present invention and the information processing apparatus provided with the objective lens driving means are such that the lens holder holding the first objective lens and the second objective lens is driven and controlled. In addition to selectively performing tracking control and focus control of the objective lens with respect to the optical information recording medium, and switching of the objective lens disposed in the optical path of the light beam, the objective lens is disposed in the optical path of the light beam by switching the objective lens. The identified objective lens is identified.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an optical disc device provided with an objective lens driving device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an optical disc apparatus for reproducing data from an optical disc according to an embodiment of the present invention. FIG. 2 is a block diagram of a disc drive unit for driving the optical disc shown in FIG.
Shows the structure of the optical disk shown in FIGS.

The optical disk device according to the embodiment of the present invention shown in FIG. 1 includes a key operation and display unit 4, a disk drive unit 30, a system CPU unit 50, a system ROM and RAM unit 52, a system processor unit 54, R
It comprises an AM section 56, a video decoder section 58, an audio decoder section 60, a sub-picture decoder section 62, and a D / A and reproduction processing section 64.

The key operation unit and the display unit 4 input a predetermined operation command to the optical disk device by the user operating the key from outside the optical disk device, and display the operation state and operation result of the optical disk device to the outside. Output.

The disk drive unit 30 has a system CP.
The optical disk 10 is driven by the control of the U unit 50, and the data recorded on the optical disk 10 is reproduced and output to the system processor unit 54.

The system CPU unit 50 receives the operation command from the user input from the key operation unit to the key operation unit and the display unit 4 and displays the information on the operation state and operation result of the optical disk device to the display unit. Is output, the drive control of the optical disk 10 is performed to the disk drive unit 30, the program for operating the optical disk device is read out to the system ROM and the RAM unit 52, and the system processor unit 54 is read. On the other hand, control relating to processing of data obtained from the optical disk 10 is performed. With these, the system CPU unit 50 controls each unit collectively, and controls substantially the entire optical disk device.

The system processor unit 54 includes a system C
While receiving control from the PU unit 50, receiving the reproduction data read from the optical disk 10 from the disk drive unit 30, and performing a predetermined process on the reproduction data while exchanging data with the data RAM unit 56, The data is classified into video data, audio data, and sub-video data, and each data is output to the video decoder unit 58, the audio decoder unit 60, and the sub-video decoder unit 62.

The data RAM unit 56 exchanges data with the system processor unit 54 to assist data processing in the system processor unit 54. The video decoder unit 58, the audio decoder unit 60, and the sub-picture decoder unit 62 decode the video data, audio data, and sub-picture data output from the system processor unit 54, respectively, and perform D / A and reproduction processing unit 64. Output to

The D / A and reproduction processing unit 64 converts the decoded video data, audio data, and sub-video data output from the video decoder unit 58, the audio decoder unit 60, and the sub-video decoder unit 62 from digital signals. The video signal, the audio signal, and the sub-video signal are converted into analog signals, respectively, and the video signal and the sub-video signal are output to the monitor unit 6 outside the optical disk device, and the audio signal is output to the speaker unit 8 outside the optical disk device. ,
Responsible for reproducing data recorded on the optical disc 10.

In the optical disk apparatus according to the embodiment of the present invention having the above-described configuration, the user operates the key operation unit and the display unit 4 so that the optical disk 1 can be operated.
0, that is, video data, sub-video data, and audio data are read out. The video and audio are reproduced by the monitor 6 and the speaker 8 outside the apparatus.

As already known, the optical disk 10
Although there are various structures, as shown in FIG. 3, for example, a pair of structures 18 in which a recording layer, that is, a light reflection layer 16 is formed on a transparent substrate 14, are prepared. A high-density optical disk having a structure in which information is recorded at a high density with a structure in which the layer 16 is bonded through an adhesive layer 20 so as to be sealed therein has emerged.

In the optical disk 10 having such a structure, a center hole 22 into which the spindle of the spindle motor 12 is inserted is disposed at the center thereof, and a clamp for holding the optical disk 10 at the time of rotation is provided around the center hole 22. Ping area 24 is arranged. The distance from the clamping area 24 to the outer peripheral edge of the optical disk 10 is
0 is defined in the information recording area 25 where information can be recorded. The optical disc shown in FIG. 3 has information recording areas 25 on both sides.

Each information recording area 25 has an outer peripheral area in a lead-out area 26 where information is not normally recorded, and an inner peripheral area in contact with the clamping area 24 in the same manner.
Usually, a lead-in area 27 where information is not recorded is defined, and a space between the lead-out area 26 and the lead-in area 27 is defined as a data recording area 28.

On the recording layer 16 of the information recording area 25, usually, tracks are continuously formed spirally as areas for recording data, and the continuous tracks are divided into a plurality of sectors. The data is recorded in. Data recording area 28 of information recording area 25
Is an actual data recording area in which management data, video data, sub-video data, and audio data are similarly recorded as physical shape changes such as pits.

In the read-only optical disk 10, a pit array is formed in advance on a transparent substrate 14 by a stamper, and a reflective layer is formed by vapor deposition on the surface of the transparent substrate 14 on which the pit array is formed. 16 will be formed. In the read-only optical disc 10, usually, no groove is specifically arranged as a track, and a pit row is defined as a track.
Usually, in such a high-density type optical disk 10,
While the transparent substrate of an optical disk such as a conventional CD or CD-ROM has a thickness of 1.2 mm, the transparent substrate 14 has a thickness of 1.2 mm.
Has a thickness of 0.6 mm, which is half that of the above.

In such an optical disk apparatus for reproducing data from the optical disk 10, a disk drive unit 30 for loading and driving the optical disk 10 and irradiating the optical disk 10 with a light beam retrieves information recorded on the optical disk 10. Is performed.

The disk drive unit 30 shown in FIG. 2 includes a spindle motor drive circuit 11, a spindle motor 12,
It comprises an optical head 32, a feed motor 33, a focus drive circuit 36, a feed motor drive circuit 37, a tracking drive circuit 38, an objective lens switching drive circuit 39, a head amplifier 40, and a servo processing circuit 44.

The spindle motor drive circuit 11 receives a spindle motor control signal from the servo processing circuit 44 and outputs a drive signal for driving the spindle motor 12 to the spindle motor 12.

The spindle motor 12 is fixed on a base 71 as shown in FIG. 4, and is driven by catching means (not shown) connected to a rotating shaft.
, And receives the drive signal from the motor drive circuit 11 to rotate the optical disk 10 at a predetermined rotation speed.

The optical head 32 is, for example, a CD or C
An objective lens 35 having a small numerical aperture for a D-ROM, and
The high-density recording type optical disk described with reference to FIG.
The objective lenses 34 and 35 are switched by receiving a drive signal from the objective lens switching drive circuit 39, and the objective lens selected by this switching is arranged in the optical beam path so that the A light beam, that is, a laser beam is focused.

As shown in FIG. 4, the objective lenses 34 and 35 are disposed in an objective lens driving device 31 which forms a part of the optical head 32. This objective lens driving device 31
Is mounted on a guide mechanism shown in FIG. 4 so as to be movable in the radial direction of the optical disc 10 in order to search the information recording area 25, particularly the data recording area. The guide mechanism includes a pair of guide rails 73 fixed to a base 71 so as to be parallel to the radial direction of the optical disk 10, and a carriage 72 running along the guide rails 73. The objective lens driving device 31 disposed on the carriage 72 is driven by a feed motor 33 driven by a drive circuit 37 to drive the optical disk 10.
Move in the radial direction.

In such an optical head 32, the objective lens 3 is driven by the objective lens driving device 31 as described later in detail.
4 and 35 are movably held along the optical axis, are moved in the optical axis direction in response to a drive signal from a focus drive circuit 36, and always maintain the objective lenses 34 and 35 in a focus control state. Micro beam spot is recording layer 1
6 is formed. The objective lens driving device 31
The objective lenses 34 and 35 are held movably along the radial direction of the optical disk 10 by the
The optical disk 10 is finely moved in response to the drive signal from the optical disk 10, and is always controlled to a tracking control state, so that the track on the recording layer 16 of the optical disk 10 is followed by the laser beam. Further, in the objective lens driving device 31, the objective lens switching operation described above, that is, the objective lens switching drive circuit 39
Lenses 34 and 35 by receiving drive signals from
Is switched, and the objective lens selected by this switching is arranged in the laser beam optical path.

In the optical head 32, a laser beam reflected from the optical disk 10 is detected, and this detection signal is supplied from the optical head 32 to the servo processing circuit 44 via the head amplifier 40.

The feed motor 33 receives the drive signal from the feed motor drive circuit 37 and moves the optical head 32 running along the guide rail 73 in the radial direction of the optical disk 10.

The feed motor drive circuit 37 receives a feed motor control signal from the servo processing circuit 44 and outputs a drive signal for driving the feed motor 33 to the feed motor.

The focus drive circuit 36 and the tracking drive circuit 38 receive the focus error signal and the tracking error signal from the servo processing circuit 44, respectively, and receive the objective lenses 34 and 35 disposed on the optical head 32.
Is output to the optical head 32.

The objective lens switching drive circuit 39 determines whether the type of the optical disc 10 to be searched, that is, the type of the conventional CD or the like, or the type of the high density recording type such as the DVD or the like.
That is to say, the operation is performed when the system CPU unit 50 has identified the drive signal to the optical head 32 so as to select one of the objective lenses 34 and 35 corresponding to the optical disc 10 of the identified type. Occur.

The head amplifier 40 amplifies the detection signal detected by the optical head 32 and supplies the amplified signal to the servo processing circuit 44. The servo processing circuit 44 is controlled by receiving a control signal as an access signal from the system CPU unit 50, and detects a focus error signal, a tracking error signal, a spindle motor control signal, and a feed motor from a detection signal supplied from the head amplifier 40. Control signals are generated, and these signals are respectively applied to the drive circuits 36, 38, 1
1 and 37.

In the disk drive unit 30 having such a configuration, when the system CPU unit 50 supplies a control signal as an access signal to the servo processing circuit 44, the servo processing circuit 44 supplies a drive signal to the drive circuit 37. When the optical head 32 moves in the radial direction of the optical disk 10, a predetermined sector of the recording layer 16 is accessed. This accessed sector is irradiated with a laser beam by the optical head 32. At the time of this laser beam irradiation, the objective lenses 34 and 35 disposed on the optical head 32 are controlled to a focus control state and a tracking control state. Tracks on layer 16 are tracked without defocus at a predetermined linear velocity, for example, a constant linear velocity. The reflected light from the track being tracked is detected as reproduction data by the optical head 32, and the reproduction data is amplified by the head amplifier 40 and output from the disk drive unit 30.

Next, the details of the objective lens driving device 31 in the optical head 32 shown in FIG. 2 will be described with reference to FIGS. FIG. 5 shows the appearance of the objective lens driving device 31 in the optical head 32. The objective lens driving device 31 includes a lens holder 75 that can float and rotate, and a lens holder support 74 in which the lens holder 75 is received.

The lens holder support 74 is fixed to a carriage 72 and has an opening 7 for a laser beam optical path.
An actuator base 76 having a shaft 8 is arranged, and a shaft 77 is fixed to a center portion of the actuator base 76. The lens holder support 74 has
An arc-shaped yoke 79 is fixed to the actuator base 76 along the circumference around the axis 77. In this arc-shaped yoke 79, two sets of arc-shaped permanent magnets 81 and 82 in which a pair facing each other are magnetized in the same magnetization direction are symmetrically arranged around an axis 77. This one set of permanent magnets 81
Are magnetized such that the north and south poles are arranged in a direction along the axis 77, as shown in FIG. 6, and the other set of permanent magnets 82 is, as shown in FIG. It is magnetized along 79 arcs.

Further, one of the two objective lenses 34 and 35, for example, the objective lens 35, is mounted on the lens holder support 74.
When the objective lens 35 is selected as an objective lens for irradiating a laser beam to the laser beam, that is, when the objective lens 35 is arranged in the laser beam optical path passing through the opening 78, the reflection fixed to a lens holder 75 described later is performed. Detector 100 is mounted on actuator base 7 so as to face element 92.
6 fixed. The detector 100 includes a light emitting unit 101 and a light receiving unit 102 which are arranged adjacent to each other as shown in FIG.
The light emitting unit 101 and the light receiving unit 102 are fixed to the actuator base 76 such that the surface on which the light emitting unit 101 and the light receiving unit 102 are arranged faces the reflective element 92. The light emitting unit 101 is a reflective element 9
The light emitting unit 102 emits light, and the light receiving unit 102 receives the reflected light from the reflective element 92 generated by the light emission of the light emitting unit 101.

The lens holder 75 is formed in a substantially cylindrical shape as shown in FIG.
4 are arranged, and a cavity is arranged below each of the objective lenses 34 and 35 so that a laser beam can pass therethrough.
The objective lenses 34 and 35 are fixed to the lens holder 75 so that their optical axes are arranged on the same circumference around the center of the lens holder 75.

The shaft 7 is located at the center of the lens holder 75.
7 is fixed, and this bearing 83 is inserted.
Accordingly, the lens holder 75 is supported on the shaft 77 so as to be rotatable and vertically movable. This axis 77 is disposed at a position shifted from the holding center of the objective lenses 34 and 35, and the distance from the optical axis center of the objective lens 34 to that position is equal to the distance from the optical axis center of the objective lens 35. It has become. Therefore, the lens holder 75
Is rotated, the position of the center of the optical axis of the objective lens 34 with respect to the lens holder support 74 and the position of the center of the optical axis of the objective lens 35 can be matched.

Around the lens holder 75, the above-described 2
A magnetic body 84 is embedded so as to be symmetrical with respect to the axis 77 so as to face the set of permanent magnets 81 and 82, and a magnetic coil 85 which is also symmetrically arranged with respect to the axis 77 on the magnetic body 84. , 86 are fixed.

Further, on the circumference of the lens holder 75,
Detector 1 fixed to actuator base 76 described above
The reflecting element 92 is fixed so as to face 00. The reflection element 92 is formed of, for example, a glass flat plate on which aluminum is deposited, reflects light emitted from the light emitting unit 101 disposed in the detector 100, and
This is for allowing the light receiving unit 102 arranged at the light receiving unit to receive light. Note that the reflection element 92 is not limited to a case where the reflection element 92 is an independent element disposed in the lens holder 75, and may be a case where a part of the lens holder 75 is formed as a reflection surface.

As will be described later, two objective lenses 34,
When the objective lens 35 is selected by switching the objective lens among the 35, the reflective element 92 is located to face the detector 100. Thereby, the light emitting unit 1 of the detector 100
The light emitted from 01 is reflected by the reflection element 92, returns to the detector 100 again, and is received by the light receiving unit 102 of the detector 100. When light is received by the light receiving unit 102, the detector 100 generates a detection signal. By confirming the generation of the detection signal, it is detected that the objective lens 35 is selected.

If the objective lens 34 is selected by switching the objective lens, since the reflecting element 92 is not located opposite to the detector 100, even if light is emitted from the light emitting section 101 of the detector 100. This light is received by the light receiving unit 10
No light is received at 2. As a result, since the generation of the detection signal from the detector 100 is not confirmed, it is detected that the objective lens 34 is selected instead of the objective lens 35.

Next, FIG. 9 shows an objective lens driving device 31 and an optical unit 90 constituting an optical head 32 together with the objective lens driving device 31. This optical unit 90
Is composed of a semiconductor laser 94, a collimator lens 91, beam splitters 93 and 95, condenser lenses 96 and 97, and photodetectors 98 and 99, which are housed and fixed in an internal space of a carriage 72 as a movable body.

The semiconductor laser 94 generates a laser beam for irradiating the optical disk 10 and emits the laser beam to the collimator lens 91. The collimator lens 91 enters and collimates the laser beam generated by the semiconductor laser 94, that is, converts the divergent light into parallel light, and emits it to the beam splitter 93. The beam splitter 93 changes the traveling direction of the laser beam collimated by the collimating lens 91 by reflection, and
And the laser beam reflected from the optical disk 10 and emitted from the opening 78 of the objective lens driving device 31 is transmitted and emitted to the beam splitter 95.

The beam splitter 95 splits the laser beam emitted from the beam splitter 93 into two systems, one in which the laser beam is guided to the photodetector 98 and the other in which the laser beam is guided to the photodetector 99. The condensing lenses 96 and 97 converge the laser beams split into two systems by the beam splitter 95 to photodetectors 98 and 99, respectively. The photodetectors 98 and 99 generate detection signals for generating the information signal, the focus error signal, and the tracking error signal by condensing the laser beam by the condensing lenses 96 and 97.

The optical unit 90 having such a configuration.
The laser beam emitted from the semiconductor laser 94 of
The light is collimated by a collimator lens 91 in the optical unit 90, is reflected by a beam splitter 93, and is guided out of the optical unit 90. The laser beam that has exited the optical unit 90 is a selected one of the objective lenses 34 and 35 of the objective lens driving device 31 fixed on the carriage 72, for example, the objective lens 35.
And focused on a recording track of the optical disk 10.

The laser beam reflected by the optical disk 10 is returned to the optical unit 90 via the above-mentioned one objective lens, that is, the objective lens 35. In the optical unit 90, the laser beam passes through a beam splitter 93 and is split into two systems by a beam splitter 95. Each of the two divided laser beams is condensed by condensing lenses 96 and 97, is incident on photodetectors 98 and 99 arranged in an optical unit 90, and is photoelectrically converted as detection signals. This photo detector 98, 9
9, the information signal, the focus error signal, and the tracking error signal are generated.

By using this focus error signal, one of the objective lenses, ie, the objective lens 3
5 is detected in the focus direction, and a current is supplied to one of coils 85 and 86, which will be described later, so as to correct the position shift. Further, by using the tracking error signal, the positional deviation of the one objective lens, that is, the objective lens 35 in the tracking direction is detected,
In order to correct this displacement, coils 85 and 86 described below are used.
Current is supplied to the other side. In this way, information is read from the recording tracks of the optical disk 10.

Next, the details of the operation of the objective lens driving device 31 will be described below. First, the reason why the lens holder 75 is magnetically levitated in the lens holder support 74 by a so-called magnetic spring will be described. As described above, two sets of permanent magnets 81 and 82 are arranged symmetrically around the axis 77 of the lens holder support 74 on the lens holder support 74 as shown in FIG. Are opposed to each other with a gap. That is, a magnetic body is disposed symmetrically around the axis 77, and the magnetic body 84 is fixed to the lens holder 75. Therefore, the magnetic material 84 is attracted to the permanent magnets 81 and 82, and the permanent magnets 81 and 82 and the magnetic material 84
As shown in (a) and (b), a certain stable state is maintained at a certain neutral position, so that the lens holder 75 is magnetically levitated in the lens holder support 74.

Here, when a disturbance is given to the lens holder 75 and the magnetic body 84 is displaced upward from the neutral position as shown in FIG. 11C, the magnetic body 84 moves upward. The downward force that returns the magnetic body 84 to the neutral position acts more than the force, and as a result, the magnetic body 84 is returned to the neutral position. Similarly, the lens holder 7
When the magnetic material 84 is displaced downward from the neutral position as shown in FIG. 11E due to the disturbance applied to the magnetic material 84, the magnetic material 84 is applied to the magnetic material 84 more than the downward force. A large upward force acts to return the magnetic body 84 to the neutral position, and as a result, the magnetic body 84 returns to the neutral position.

When a disturbance is given to the lens holder 75 and the magnetic body 84 is deviated leftward from the neutral position as shown in FIG. The rightward force that returns the magnetic body 84 to the neutral position acts more than the forward force, and as a result, the magnetic body 84
Will be returned to the neutral position. Similarly, when a disturbance is given to the lens holder 75 and the magnetic body 84 is deviated rightward from the neutral position as shown in FIG. Than the magnetic material 8
4 returns to the neutral position, and the force in the left direction acts greatly. As a result, the magnetic body 84 is returned to the neutral position.

Since the magnetic body 84 is mounted at a position symmetrical with respect to the axis 77, if the objective lens is switched by rotating the lens holder 75 as described below, the magnetic attraction is caused by the magnetic attraction. When the body 84 is maintained at the neutral position, the position of one objective lens before switching of the objective lens, for example, the position of the objective lens 34 is changed to the position of the other objective lens after switching, for example, the position of the objective lens 35. Matches. Therefore, the other objective lens can be used while being adjusted between the optical unit 90 and the one objective lens.

Next, the switching operation of the objective lenses 34 and 35 for selecting the objective lenses 34 and 35 will be described. As shown in FIG. 14A, when the objective lens 34 having a large numerical aperture is arranged in the optical path of the laser beam, the coil 85 is opposed to the permanent magnet 82 magnetized in the circumferential direction, and It is assumed that the coil 86 is opposed to the permanent magnet 81 magnetized in. This state corresponds to the state where the magnetic body 84 is maintained at the neutral position as described above, and the lens holder 75 is stably maintained at the same position.

In such a stable state, FIG.
At time t1 shown in FIG. 12A, the arrow P in FIG.
A current that interacts with the magnetic field generated by the permanent magnet 82 is supplied to the axial portions 85A and 85B in which a positive current indicated by o is parallel to the axis 77 of the coil 85. The generated force FF is generated, and the lens holder 75 starts rotating. Between the time point t1 and the time point t2, the coil 85 is given a starting force enough to sufficiently rotate the lens holder 75.

At time t2 when the coil 85 starts to rotate and the coil portion 85A on the retreat side of the coil 85 is opposed to the N pole of the permanent magnet 82, the current supplied to the coil 85 is reduced as shown in FIG.
It is inverted as shown in FIG. By this reversal, a current in the negative direction indicated by an arrow No in FIG. 12A is supplied to an axial portion 85 </ b> A parallel to the axis 77 of the coil 85, and a current interacting with the magnetic field generated by the permanent magnet 82 is supplied. Rotational force FF that retreats the coil 85 from the permanent magnet 82 is generated between the coil portion 85A on the retreat side of 85 and the N pole of the permanent magnet 82. As a result, the coil 85 is rotated toward the front surface of the permanent magnet 81.

At time t3 during the rotation, the current supply to the coil 85 is stopped. After time t3, the lens holder 75 is rotated by inertia, and the coil 85 is temporarily moved to the permanent magnet 81.
However, the coils 85 and 86 are returned to the stable neutral positions according to the principle described above with reference to FIG.

The rotation of the lens holder 75 causes the coil 85 to move the permanent magnet 8 as shown in FIG.
1, the coil 86 is opposed to the permanent magnet 82,
Instead of the objective lens 34 having a large numerical aperture, an objective lens 35 having a small numerical aperture is arranged in the optical path of the laser beam, and the objective lens is substantially switched.

On the other hand, as shown in FIG. 14B, when the objective lens 35 having a small numerical aperture is disposed in the optical path of the laser beam, the coil 86 is attached to the permanent magnet 82 which is magnetized in the circumferential direction. And the coil 85 is opposed to the permanent magnet 81 magnetized in the axial direction. This state corresponds to the state where the magnetic body 84 is maintained at the neutral position as described above, and the lens holder 75 is stably maintained at the same position.

In such a stable state, FIG.
At time t1 shown in FIG. 12B, the arrow N in FIG.
A current in the negative direction indicated by o is supplied to the axial portions 86C and 86D parallel to the axis 77 of the coil 86 so as to interact with the magnetic field generated by the permanent magnet 82. The generated force FR is generated, and the lens holder 75 starts rotating. Between the time point t1 and the time point t2, a starting force enough to sufficiently rotate the lens holder 75 is applied to the coil 86.

At time t2 when the coil 86 starts to rotate and the coil portion 86C on the retreat side of the coil 86 is opposed to the S pole of the permanent magnet 82, the current supplied to the coil 86 is changed as shown in FIG.
It is inverted as shown in FIG. As a result of this inversion, a current in the positive direction indicated by an arrow Po in FIG. A rotational force FR for retreating the coil 86 from the permanent magnet 82 is generated between the coil portion 86C on the exit side of the 86 and the S pole of the permanent magnet 82. As a result, the coil 86 is rotated toward the front surface of the permanent magnet 81.

At time t3 during the rotation, the current supply to the coil 86 is stopped. After time t3, the lens holder 75 is rotated by inertia, and the coil 86 is temporarily moved to the permanent magnet 81.
However, the coils 85 and 86 are returned to the stable neutral positions according to the principle described above with reference to FIG.

The rotation of the lens holder 75 causes the coil 85 to move the permanent magnet 8 as shown in FIG.
2, the coil 86 is opposed to the permanent magnet 81,
Instead of the objective lens 35 having a small numerical aperture, an objective lens 34 having a large numerical aperture is arranged in the optical path of the laser beam, and the objective lens is substantially switched.

When the objective lenses 34 and 35 are switched by rotating the lens holder 75, the rotating shaft 77
If the clearance between the first objective lens 34 and the second objective lens 35 is ignored, the clearance between the first objective lens 34 and the second objective lens 35 is ignored.

The focus control operation and the tracking control operation of the objective lens driving device 31 shown in FIG. 5 will be described below. As shown in FIG. 14A, when the objective lens 34 having a large numerical aperture is arranged in the laser beam optical path, a coil opposed to the permanent magnet 81 magnetized in the axial direction for focus control. 86
Acts as a focus control coil, and a coil 85 opposed to a permanent magnet 82 circumferentially magnetized for tracking control acts as a tracking control coil.

That is, as shown in FIG. 12 (a), the focus coil driving current F responds to the focus error signal.
When i is supplied to the coil 86, an interaction occurs between the circumferential portions 86A and 86B of the coil 86 and the magnetic field generated by the permanent magnet 81, and the coil 86 is directed upward or downward depending on the direction of the current Fi. Is applied, the lens holder 75 is moved up and down along the axial direction, and the objective lens 34 is controlled to a focused state. When the tracking coil drive current Ti is supplied to the coil 85 in response to the tracking error signal, an interaction occurs between the axial portions 85A and 85B of the coil 85 and the magnetic field generated by the permanent magnet 82, and the current is reduced. A rightward or leftward force acts on the coil 85 in accordance with the direction of Ti, the lens holder 75 is rotated in the circumferential direction, and the objective lens 34 is controlled to the tracking state.

On the other hand, as already described, the objective lens 3
After the object lens 4 is switched to the objective lens 35, as shown in FIG.
5 is disposed in the laser beam optical path, and a coil 85 facing a permanent magnet 81 axially magnetized for focus control acts as a focus control coil and is magnetized in a circumferential direction for tracking control. A coil 86 facing the permanent magnet 82 functions as a tracking control coil.

That is, as shown in FIG. 12B, the focus coil driving current F responds to the focus error signal.
When i is supplied to the coil 85, an interaction occurs between the circumferential portions 85C and 85D of the coil 85 and the magnetic field generated by the permanent magnet 81, and the coil 85 is directed upward or downward depending on the direction of the current Fi. Is applied, the lens holder 75 is moved up and down along the axial direction, and the objective lens 34 is controlled to a focused state. When the tracking coil driving current Ti is supplied to the coil 86 in response to the tracking error signal, an interaction occurs between the axial portions 86C and 86D of the coil 86 and the magnetic field generated by the permanent magnet 82, and the current A rightward or leftward force acts on the coil 86 in accordance with the direction of Ti, the lens holder 75 is rotated along the circumferential direction, and the objective lens 34 is controlled to a tracking state.

As described above, the objective lens driving device according to the present invention can switch the objective lenses 34 and 35 with the coil that performs the tracking operation without applying an external force. A stable signal can be reproduced without tilting the optical axis. In addition, since the role of the coils 85 and 86 can be switched from tracking control operation to focus control operation or vice versa when the objective lens is switched, the coil use efficiency is improved and the drive sensitivity is improved. Is done.

Next, in the objective lens driving device 31 having such a configuration, identification of the selected objective lens, which is necessary for accurately performing the tracking control operation, the focus control operation, and the objective lens switching operation, is described. The operation will be described with reference to FIG.

FIG. 15 shows the relationship between the reflective element 92 and the detector 100 for identifying which objective lens is located in the laser beam optical path in the objective lens driving device shown in FIG. ing. Note that FIGS. 5 and 9
When the objective lens 35 having a small numerical aperture is arranged in the optical path of the laser beam as shown in FIG.
It is assumed that the detector 2 and the detector 100 are arranged in a positional relationship such that they face each other.

As shown in FIG. 15 (a), when the lens holder 75 is rotated and the objective lens 35 is arranged in the optical path of the laser beam, the light emitted from the detector 100 is closely opposed. The light is reflected by the reflection element 92. When the reflected light returns to the detector 100 again and is received by the detector 100, the detector 100 generates a detection signal in accordance with the reception of the light. Therefore, when a detection signal is generated from the detector 100, the objective lens 35 having a small numerical aperture is selected in the objective lens driving device 31 and is in an effective state, that is, the CD objective lens 35 is It is identified as being located in the optical path.

On the other hand, as shown in FIG. 15B, when the objective lens 34 for a high-density recording optical disk having a large numerical aperture is arranged in the optical path of the laser beam, the reflection element 92 and the detector 100 Is no longer in a close and opposed positional relationship. As a result, light emitted from the detector 100 is not reflected by the reflective element 92, and is not reflected by the detector 100.
Since no light is received, no detection signal is generated. Therefore, when no detection signal is generated from the detector 100, the objective lens 34 having a large numerical aperture is selected in the objective lens driving device 31 and is in an effective state. It is identified as being located in the optical path of the laser beam.

FIG. 16 shows the result of the identification.
Drive circuits 106, 10 according to the switching of the objective lens
8 is a block diagram of a circuit for switching the 8. In the circuit shown in FIG. 16, an objective lens identification circuit 104 that generates an identification signal for identifying the type of the objective lenses 34 and 35 according to the presence or absence of a detection signal from the detector 100 is connected to the detector 100. An identification signal is input from the objective lens identification circuit 104 to the CPU 50 as necessary.

This identification signal is output from the objective lens identification circuit 104.
Is input to the CPU unit 50 from the key operation and display unit 4, the type of the loaded medium, that is, whether it is a high-density type optical disk or a general optical disk such as a CD Is compared with the identification signal of the medium type indicating When the type of the medium matches the type of the objective lens, the reproducing operation is started as it is. On the other hand, if they do not match, the objective lens switching drive signal shown in FIG. 13 is generated to switch the objective lens.

In the circuit shown in FIG. 16, the CPU 5 receives an identification signal from the objective lens identification circuit 104.
0, the focus error signal generation circuit 10
3. A focus servo loop is formed by the focus servo circuit 105, one of the coils 85 and 86, and one of the drive circuits 106 and 108 corresponding to the coil. Servo circuit 107, coil 8
A tracking servo loop is formed by one of the coils 5 and 86 and one of the drive circuits 106 and 108 corresponding to the coil.

Further, in this configuration, the focus servo circuit 105 and the tracking servo circuit 107
And a servo loop switching circuit 110 between the drive circuits 106 and 108. In the servo loop switching circuit 110, the connection is switched by the CPU unit 50 responding to the identification signal from the objective lens identification circuit 104 for identifying the type of the objective lenses 34 and 35 so that an appropriate servo loop is formed.

That is, when the coil 85 acts as a focus coil, the servo loop switching circuit 110 is switched by a signal from the CPU 50, and the drive circuit 106 connected to the coil 85 is connected to the focus servo circuit 105. A drive circuit 108 connected to the coil 86 is connected to the tracking servo circuit 107. When the coil 85 operates as a tracking coil, the servo loop switching circuit 110 is similarly switched by a signal from the CPU unit 50, and the drive circuit 106 connected to the coil 85 is connected to the tracking servo circuit 107. The coil 86
Is connected to the focus servo circuit 105.

In the above-described objective lens switching and objective lens driving device, when the number of objective lenses arranged in the objective lens driving device is n, 2n permanent magnets and coils are used as a magnetic circuit in the circumferential direction. It is desirable to arrange them in a shape. In such a relationship, the coils and the permanent magnets facing each other form a magnetic circuit for focus or tracking control, and the acting force acts evenly on the lens holder at the time of focus or tracking control. Can be driven. That is, good vibration characteristics and driving characteristics can be realized.

As described above, according to the present invention, different types of objective lenses are fixed to the lens holder and the objective lens can be selected by rotating the lens holder. It is possible to selectively switch between objective lenses of the type.

In addition, when one of the objective lenses is arranged in the optical path of the laser beam, a reflecting element and a detector which are in close proximity to each other are arranged on a lens holder and a lens holder support, respectively. Because it is configured to detect the presence or absence of reflected light from the detector by the detector,
According to the presence or absence of the detection signal from the detector, the type of the objective lens arranged in the optical path of the laser beam can be easily identified.

Further, in this configuration, the detector emits and receives light to and from the reflective element, and the identification of the objective lens is performed based only on the transmission and reception of light between the reflective element and the detector. Therefore, the reflective element and the detector are dedicated parts for the purpose of identifying the objective lens, and the precision in the manufacture and design of the part itself that affects the identification of the objective lens and the precision in assembling and mounting the part are controlled with extremely high precision. Therefore, it is possible to reliably identify the type of the objective lens arranged in the laser beam optical path.

[0091]

Since the present invention is configured as described above, the objective lens can be selectively switched between different types of objective lenses, and the objective lens can be easily and reliably arranged in the laser beam optical path. The type of the objective lens can be identified, and information processing on the optical information recording medium can be performed in an appropriate manner according to the identification result.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing details of a disk drive unit according to the embodiment of the present invention.

FIG. 3 is a perspective view schematically showing the structure of the optical disc shown in FIG.

FIG. 4 is a plan view schematically showing an objective lens driving device according to an embodiment of the present invention.

FIG. 5 is a perspective view schematically showing an objective lens driving device according to the embodiment of the present invention.

FIG. 6 is a cross-sectional view showing an internal structure of a lens holder support of the objective lens driving device according to the embodiment of the present invention.

FIG. 7 is a perspective view schematically showing a detector of the objective lens driving device according to the embodiment of the present invention.

FIG. 8 is a perspective view showing a lens holder of the objective lens driving device according to the embodiment of the present invention.

FIG. 9 is a schematic diagram showing an objective lens driving device according to an embodiment of the present invention and an optical system related to the objective lens driving device.

FIG. 10 is a conceptual diagram for explaining the principle that the lens holder is magnetically levitated in the objective lens driving device according to the embodiment of the present invention.

11 is a perspective view illustrating the principle of magnetically levitating the lens holder in the arrangement shown in FIG.

FIG. 12 is a perspective view showing a magnetic circuit for an objective lens switching operation in the objective lens driving device according to the embodiment of the present invention.

FIG. 13 is a waveform chart showing signals for causing the magnetic circuit shown in FIG. 12 to perform an objective lens switching operation.

FIG. 14 is a plan view showing an objective lens switching operation in the objective lens driving device according to the embodiment of the present invention.

FIG. 15 is a cross-sectional view showing an identification operation for identifying which objective lens is located in the laser beam optical path in the objective lens driving device according to the embodiment of the present invention.

16 is a block diagram showing a circuit for switching the drive system of the objective lens drive device based on the identification operation shown in FIG.

[Explanation of symbols]

Reference Signs List 10 optical information recording medium (optical disk) 14 transparent substrate 16 light reflecting layer 28 data recording area 30 disk drive unit 31 objective lens driving device 32 optical head 34, 35 objective lens 36 focus driving circuit 37 driving circuit 39 objective lens switching driving circuit 44 Servo processing circuit 50 System CPU section 54 System processor section 56 Data RAM section 58 Video decoder section 60 Audio decoder section 62 Sub-picture decoder section 64 D / A and reproduction processing section 72 Carriage 73 Guide rail 74 Lens holder support 75 Lens holder 77 Rotating shaft 81, 82 Magnet 83 Rotating bearing 84 Magnetic body 85, 86 Coil 90 Optical unit 92 Reflecting means (Reflecting element) 100 Detecting means (Detector) 101 Light emitting unit 102 Light receiving unit 104 Identification means (Objective) Lens identification circuit) 105 Focus control circuit (focus servo circuit) 107 Tracking control circuit (track servo circuit) 110 Switching means (servo loop switching circuit)

Claims (8)

[Claims] An objective lens for irradiating an optical information recording medium with a light beam is operated in an optical path of the light beam to focus the light beam on a track of the optical information recording medium on which information is recorded. In the objective lens driving device, which is brought into an in-focus state, and the in-focus state is made to follow the light beam in the in-focus state, a first light beam suitable for the first optical information recording medium is condensed. An objective lens, a second objective lens for condensing a light beam suitable for a second optical information recording medium different from the first optical information recording medium, and the first and second objective lenses A lens holder for holding the first objective lens and the holding center of the second objective lens by the lens holder, and in the optical axis direction of the first and second objective lenses. To One of the first and second objective lenses by pivotally supporting the lens holder so as to be rotatable about the rotation axis and movable in the direction of the rotation axis. A lens holder support that can be disposed in the optical path of the light beam and movably in the optical axis direction, and the first objective lens is provided by the lens holder support via the lens holder. While being disposed in the optical path of the beam, the lens holder is slightly rotated to control the first objective lens to the tracking state, and the lens holder is rotated to drive the first objective lens. First objective lens driving means for arranging the second objective lens in the optical path of the light beam instead of a lens, and the first objective lens by the lens holder support via the lens holder While the lens holder is arranged in the optical path of the light beam, the lens holder is slightly moved along the optical axis of the first objective lens to control the first objective lens in the focused state. The lens holder is slightly rotated by the objective lens driving means, via the lens holder, by the lens holder support, in a state where the second objective lens is arranged in the optical path of the light beam. Controlling the second objective lens to the focusing state, rotating the lens holder and replacing the second objective lens with the first objective lens in the optical path of the light beam. Three objective lens driving means, via the lens holder, by the lens holder support, in a state where the second objective lens is arranged in the optical path of the light beam, Fourth objective lens driving means for finely moving the lens holder along the optical axis of the second objective lens to control the second objective lens in the in-focus state, and arranged at a predetermined position on the lens holder. A reflecting means for reflecting light, and when the first objective lens is arranged in an optical path of the light beam, the reflecting means is arranged at a predetermined position on the lens holder support opposite to the reflecting means, and emits light. And a detecting means for detecting the reception of the reflected light from the reflecting means caused by the light emission. 2. An optical system according to claim 1, wherein the objective lens for irradiating the optical information recording medium with a light beam is operated in an optical path of the light beam to focus the light beam on a track of the optical information recording medium on which information is recorded. In the objective lens driving device, which is brought into an in-focus state, and the in-focus state is made to follow the light beam in the in-focus state, a first light beam suitable for the first optical information recording medium is condensed. An objective lens, a second objective lens for condensing a light beam suitable for a second optical information recording medium different from the first optical information recording medium, and the first and second objective lenses A lens holder for holding the first and second objective lenses at a position where the distance from the optical axis center of the first objective lens is equal to the distance from the optical axis center of the second objective lens; and Objective lens The first and second objectives have a rotation axis along the optical axis direction, and pivotally support the lens holder so as to be able to rotate around the rotation axis and move in the rotation axis direction. A lens holder support that supports one of the lenses in the optical path of the light beam and that is movable in the optical axis direction; and While the objective lens is disposed in the optical path of the light beam, the lens holder is slightly rotated to control the first objective lens to the focusing state, and the lens holder is rotationally driven. First objective lens driving means for arranging the second objective lens in the optical path of the light beam in place of the first objective lens, and via the lens holder, by the lens holder support, No. In a state where the objective lens is disposed in the optical path of the light beam, the lens holder is finely moved along the optical axis of the first objective lens to control the first objective lens in the focused state. The second objective lens driving means, and the lens holder via the lens holder, the lens holder is minutely moved in a state where the second objective lens is arranged in the optical path of the light beam. The second objective lens is rotated to control the focusing state, and the lens holder is rotated to drive the first objective lens in the optical path of the light beam instead of the second objective lens. A third objective lens driving means disposed on the lens holder, the second objective lens is disposed in an optical path of the light beam by the lens holder support via the lens holder. A fourth objective lens driving means for finely moving the lens holder along the optical axis of the second objective lens to control the second objective lens in the in-focus state, A reflection unit disposed at a predetermined position to reflect light, and the first objective lens faces the reflection unit when the first objective lens is disposed in an optical path of the light beam, and the second objective lens is When it is arranged in the optical path of the light beam, it is arranged at a predetermined position of the lens holder support that does not face the reflecting means, emits light, and receives reflected light from the reflecting means generated by the light emission. An objective lens driving device, comprising: detecting means for detecting. 3. An optical lens for irradiating an optical information recording medium with a light beam in an optical path of the light beam to focus the light beam on a track of the optical information recording medium on which information is recorded. In the objective lens driving device, which is brought into the focused state, and the light beam in the focused state is made to follow and the focused state is achieved, the first focusing of the light beam suitable for the first optical information recording medium is performed. An objective lens, a second objective lens for condensing a light beam suitable for a second optical information recording medium different from the first optical information recording medium, and the first and second objective lenses A lens holder for holding the first and second objective lenses at a position where the distance from the optical axis center of the first objective lens is equal to the distance from the optical axis center of the second objective lens; and Of the objective lens The first and second objective lenses have a rotation axis along the optical axis direction, and pivotally support a lens holder so as to be able to rotate around the rotation axis and move in the rotation axis direction. A lens holder support that supports either one of them in an optical path of the light beam and that is movable in the optical axis direction; and a first coil disposed in the lens holder and the lens holder support. Is composed of the first magnet
The lens holder is moved along the optical axis of the first objective lens while the first objective lens is disposed in the optical path of the light beam by the lens holder support via the lens holder. A first electromagnetic driving means for finely moving the first objective lens in the in-focus state, a second coil disposed on the lens holder and a second coil disposed on the lens holder support. Composed of magnets,
Through the lens holder, the lens holder holder slightly rotates the lens holder in a state where the first objective lens is disposed in the optical path of the light beam. And the second objective lens is arranged in the optical path of the light beam in place of the first objective lens by controlling the lens holder to the combined tracking state and rotating the lens holder beyond the tracking operation range. A second electromagnetic driving means, comprising the second coil and the first magnet, the second objective lens of the light beam by the lens holder support via the lens holder In a state where the second objective lens is arranged in the optical path, the lens holder is finely moved along the optical axis of the second objective lens to control the second objective lens in the focused state. A third electromagnetic drive unit that controls the first objective lens and the second magnet, and the second objective lens is configured so that the light beam is transmitted by the lens holder support through the lens holder. While the lens holder is disposed in the optical path, the lens holder is slightly rotated to control the second objective lens to the tracking state, and the lens holder is driven to rotate beyond the tracking operation range. A fourth electromagnetic driving means for disposing the first objective lens in the optical path of the light beam in place of the second objective lens, and a reflection means for disposing light at a predetermined position of the lens holder, for reflecting light. Means, facing the reflecting means when the first objective lens is disposed in the optical path of the light beam, wherein the second objective lens is disposed in the optical path of the light beam. In this case, a detecting means is provided at a predetermined position of the lens holder support that is not opposed to the reflecting means, emits light, and detects the reception of reflected light from the reflecting means caused by the light emission. An objective lens driving device, characterized in that: 4. An optical lens for irradiating an optical information recording medium with a light beam in an optical path of the light beam to focus the light beam on a track of the optical information recording medium on which information is recorded. In the objective lens driving device, which is brought into an in-focus state, and the in-focus state is made to follow the light beam in the in-focus state, a first light beam suitable for the first optical information recording medium is condensed. An objective lens, a second objective lens for condensing a light beam suitable for a second optical information recording medium different from the first optical information recording medium, and the first and second objective lenses A lens holder for holding the first and second objective lenses at a position where the distance from the optical axis center of the first objective lens is equal to the distance from the optical axis center of the second objective lens; and Objective lens The first and second objectives have a rotation axis along the optical axis direction, and pivotally support the lens holder so as to be able to rotate around the rotation axis and move in the rotation axis direction. A lens holder support for supporting any one of the lenses in the optical path of the light beam and movably in the optical axis direction; a first coil disposed in the lens holder; and the first object When the lens is disposed in the optical path of the light beam, the lens is opposed to the first coil, and when the second objective lens is disposed in the optical path of the light beam, the second objective lens is disposed in the lens holder. And a first magnet arranged at a predetermined position of the lens holder support facing the second coil, and the first objective lens is provided by the lens holder support via the lens holder. In the optical path of the light beam The first electromagnetic driving means for finely moving the lens holder along the optical axis of the first objective lens to control the first objective lens in the in-focus state, A second coil and, when the first objective lens is located in the optical path of the light beam, facing the second coil, and the second objective lens is located in the optical path of the light beam. And a second magnet arranged at a predetermined position of the lens holder support opposed to the first coil, and the first holder is provided by the lens holder support via the lens holder. While the objective lens is placed in the optical path of the light beam, the lens holder is slightly rotated to control the first objective lens in the tracking state, and the lens holder is A second electromagnetic driving means for arranging the second objective lens in the optical path of the light beam in place of the first objective lens by being rotationally driven beyond the operating range of the first coil; and The lens holder is formed by the first magnet and the lens holder, with the second objective lens being disposed in the optical path of the light beam by the lens holder support through the lens holder. A third electromagnetic driving unit for finely moving the second objective lens along the optical axis of the second objective lens to control the second objective lens in the in-focus state; and comprising the first coil and the second magnet. Then, the lens holder is slightly rotated while the second objective lens is arranged in the optical path of the light beam by the lens holder support via the lens holder, and the second objective lens is slightly rotated. Objective And the first objective lens is disposed in the optical path of the light beam in place of the second objective lens by controlling the lens to be in the tracking state and rotating the lens holder beyond the tracking operation range. A fourth electromagnetic drive unit, a reflection unit disposed at a predetermined position of the lens holder and configured to reflect light, and the reflection is performed when the first objective lens is disposed in an optical path of the light beam. When the second objective lens is disposed in the optical path of the light beam, the second objective lens is disposed at a predetermined position on the lens holder support that does not face the reflecting means, and emits light. Detecting means for detecting reception of reflected light from the reflecting means caused by light emission. 5. An optical information recording medium, wherein an objective lens for irradiating the optical beam with a light beam is operated in the optical path of the light beam to focus the light beam on a track of the optical information recording medium on which information is recorded. In an information processing apparatus, a light beam suitable for a first optical information recording medium is converged in an information processing apparatus which is brought into a focused state by following the light beam in the focused state. A lens, a second objective lens for condensing a light beam suitable for a second optical information recording medium different from the first optical information recording medium, and the first and second objective lenses. A lens holder to be held, at a position shifted from a holding center of the first objective lens and a holding center of the second objective lens by the lens holder, and in an optical axis direction of the first and second objective lenses. Along By having a moving axis and pivotally supporting the lens holder so as to be rotatable around the rotation axis and movable in the direction of the rotation axis, one of the first and second objective lenses can A lens holder support that can be arranged in the optical path of the beam and movably supports in the direction of the optical axis; and the first objective lens is moved by the lens holder support through the lens holder. In the state where the first objective lens is arranged inside, the first objective lens is controlled to the tracking state by slightly rotating the lens holder, and the lens holder is rotationally driven to switch to the first objective lens. First objective lens driving means for arranging the second objective lens in the optical path of the light beam, and the first objective lens is moved forward by the lens holder support via the lens holder. A second objective for finely moving the lens holder along the optical axis of the first objective lens to control the first objective lens in the in-focus state while being disposed in the optical path of the light beam; Lens driving means, via the lens holder, by the lens holder support, in a state where the second objective lens is arranged in the optical path of the light beam, the lens holder is slightly rotated and the A third objective lens is controlled to the tracking state, and the third objective lens is rotated and driven to dispose the first objective lens in the optical path of the light beam instead of the second objective lens. An objective lens driving unit; and the lens in a state where the second objective lens is disposed in an optical path of the light beam by the lens holder support via the lens holder. Fourth objective lens driving means for finely moving the holder along the optical axis of the second objective lens to control the second objective lens in the in-focus state, and arranged at a predetermined position of the lens holder; A reflecting unit for reflecting light; and a light emitting unit that emits light when the first objective lens is arranged in a predetermined position of the lens holder support opposite to the reflecting unit when the first objective lens is arranged in an optical path of the light beam. Detecting means for detecting the reception of reflected light from the reflecting means caused by the light emission; and, based on the detection result by the detecting means, in the optical path of the light beam among the first and second objective lenses. Identification means for identifying an objective lens disposed in the optical beam; and a light beam converging by one of the first and second objective lenses disposed in an optical path of the light beam. Based on the reflected light from the lighted optical information recording medium,
A tracking control circuit for causing the first objective lens driving means or the third objective lens driving means to perform tracking control of the one objective lens; and the light beam among the first and second objective lenses Based on the reflected light from the optical information recording medium in which the light beam was focused by one objective lens arranged in the optical path of
A focus control circuit for causing the second objective lens driving means or the fourth objective lens driving means to perform focus control of the one objective lens; and an objective lens arranged in an optical path of the light beam by the identification means. Is identified as the first objective lens, the tracking control circuit controls the first objective lens driving means to perform tracking control of the one objective lens, and the focus control circuit controls the second objective lens. When the objective lens driving unit performs focus control of the one objective lens, and when the identification unit identifies the objective lens arranged in the optical path of the light beam as the second objective lens, In place of the first objective lens driving means, the third objective lens driving means is provided with the track of the one objective lens. Switching means for performing king control and causing the fourth objective lens driving means to perform focus control of the one objective lens instead of the second objective lens driving means. Processing equipment. 6. An optical lens for irradiating an optical information recording medium with a light beam in an optical path of the light beam to focus the light beam on a track of the optical information recording medium on which information is recorded. In an information processing apparatus, a light beam suitable for a first optical information recording medium is converged in an information processing apparatus which is brought into a focused state by following the light beam in the focused state. A lens, a second objective lens for condensing a light beam suitable for a second optical information recording medium different from the first optical information recording medium, and the first and second objective lenses. A lens holder for holding the lens holder at a position where the distance from the optical axis center of the first objective lens is equal to the distance from the optical axis center of the second objective lens, and the first and second Optical axis of objective lens A rotation axis along the direction, and by pivotally supporting the lens holder so as to be able to rotate around the rotation axis and to move in the direction of the rotation axis, the first and second objective lenses are supported. A lens holder support that supports one of them in the optical path of the light beam and is movably supported in the optical axis direction; and the first object is provided by the lens holder support via the lens holder. While the lens is arranged in the optical path of the light beam, the lens holder is slightly rotated to control the first objective lens to the tracking state, and the lens holder is rotationally driven to rotate the lens. First objective lens driving means for arranging the second objective lens in the optical path of the light beam in place of the first objective lens; and Pair of In a state where the lens is arranged in the optical path of the light beam, the lens holder is finely moved along the optical axis of the first objective lens to control the first objective lens in the focused state. A second objective lens driving means, and the lens holder is slightly rotated by the lens holder support while the second objective lens is disposed in the optical path of the light beam via the lens holder. Then, the second objective lens is controlled to the focusing state, and the lens holder is rotationally driven to dispose the first objective lens in the optical path of the light beam instead of the second objective lens. A third objective lens driving means, and the lens holder supporting body via the lens holder, wherein the second objective lens is arranged in the optical path of the light beam. A fourth objective lens driving means for finely moving the lens holder along the optical axis of the second objective lens to control the second objective lens in the focused state; A reflecting means arranged at a position for reflecting light, and the first objective lens is opposed to the reflecting means when the first objective lens is arranged in an optical path of the light beam, and the second objective lens is provided with the light. When it is arranged in the optical path of the beam, it is arranged at a predetermined position of the lens holder support that does not face the reflecting means, emits light, and detects the reception of reflected light from the reflecting means caused by the emission. Detecting means for detecting, when the detecting means detects the reception of the reflected light from the reflecting means, the objective lens disposed in the optical path of the light beam as a first objective lens An identification unit that identifies an objective lens disposed in an optical path of the light beam from a second objective lens when the detection unit does not detect the reception of the reflected light from the reflection unit; Tracking control of the one objective lens based on the reflected light from the optical information recording medium in which the light beam is focused by one of the second objective lenses arranged in the optical path of the light beam. A tracking control circuit that supplies a control signal to the first objective lens driving unit or the third objective lens driving unit to the first objective lens driving unit or the third objective lens driving unit. A control system for performing focus control of the one objective lens based on the reflected light from the optical information recording medium in which the light beam is focused by the one objective lens arranged in the optical path. A focus control circuit that supplies a control signal to the second objective lens driving unit or the fourth objective lens driving unit; and the objective lens arranged in the optical path of the light beam by the identification unit is the second objective lens driving unit. When it is identified as one objective lens, a control signal from the tracking control circuit is supplied to the first objective lens driving means, and the focus control circuit is supplied to the second objective lens driving means. When the objective lens arranged in the optical path of the light beam is identified as the second objective lens by the identification means, the control signal is replaced with the first objective lens driving means. Supply the control signal from the tracking control circuit to the third objective lens driving means, and replace the second objective lens driving means with the control signal. A switching unit for supplying a control signal from the focus control circuit to a fourth objective lens driving unit. 7. An optical lens for irradiating an optical information recording medium with a light beam is operated in an optical path of the light beam to focus the light beam on a track of the optical information recording medium on which information is recorded. In an information processing apparatus, a light beam suitable for a first optical information recording medium is converged in an information processing apparatus which is brought into a focused state by following the light beam in the focused state. A lens, a second objective lens for condensing a light beam suitable for a second optical information recording medium different from the first optical information recording medium, and the first and second objective lenses. A lens holder for holding the lens holder at a position where the distance from the optical axis center of the first objective lens is equal to the distance from the optical axis center of the second objective lens, and the first and second Optical axis of objective lens By having a rotation axis along the direction and pivotally supporting the lens holder so as to be able to rotate around the rotation axis and to move in the direction of the rotation axis, any one of the first and second objective lenses can be used. A lens holder support that supports one of the two in the optical path of the light beam and that is movable in the optical axis direction; a first coil disposed in the lens holder; and a first coil disposed in the lens holder support. Composed of a first magnet,
The lens holder is moved along the optical axis of the first objective lens while the first objective lens is disposed in the optical path of the light beam by the lens holder support via the lens holder. A first electromagnetic driving means for finely moving the first objective lens in the in-focus state, a second coil disposed on the lens holder and a second coil disposed on the lens holder support. Composed of magnets,
Through the lens holder, the lens holder holder slightly rotates the lens holder in a state where the first objective lens is disposed in the optical path of the light beam. And the second objective lens is arranged in the optical path of the light beam in place of the first objective lens by controlling the lens holder to the combined tracking state and rotating the lens holder beyond the tracking operation range. A second electromagnetic driving means, comprising the second coil and the first magnet, the second objective lens of the light beam by the lens holder support via the lens holder In a state where the second objective lens is arranged in the optical path, the lens holder is finely moved along the optical axis of the second objective lens to control the second objective lens in the focused state. A third electromagnetic drive unit that controls the first objective lens and the second magnet, and the second objective lens is configured so that the light beam is transmitted by the lens holder support through the lens holder. While the lens holder is disposed in the optical path, the lens holder is slightly rotated to control the second objective lens to the tracking state, and the lens holder is driven to rotate beyond the tracking operation range. A fourth electromagnetic driving means for disposing the first objective lens in the optical path of the light beam in place of the second objective lens, and a reflection means for disposing light at a predetermined position of the lens holder, for reflecting light. Means, facing the reflecting means when the first objective lens is disposed in the optical path of the light beam, wherein the second objective lens is disposed in the optical path of the light beam. Detecting means disposed at a predetermined position of the lens holder support that is not opposed to the reflecting means, emits light, and detects the reception of reflected light generated from the reflecting means from the reflecting means; When it is detected that the reflected light from the reflecting means is received, the objective lens arranged in the optical path of the light beam is identified as the first objective lens, and the reflected light from the reflecting means is detected by the detecting means. Identification means for identifying an objective lens arranged in the optical path of the light beam from a second objective lens when light reception is not detected; and the light beam of the first and second objective lenses The tracking control of the one objective lens is performed based on the reflected light from the optical information recording medium in which the light beam is condensed by the one objective lens arranged in the optical path. A tracking control circuit that supplies a control signal to the first coil or the second coil, and one of the first and second objective lenses, which is disposed in an optical path of the light beam. On the basis of the reflected light from the optical information recording medium in which the light beam is focused by the objective lens, a control signal for performing focus control of the one objective lens is transmitted to the first coil or the second coil. A focus control circuit that supplies the second coil with the tracking control when the objective lens arranged in the optical path of the light beam is identified as the first objective lens by the identification unit. A control signal from the focus control circuit to the first coil and a light signal from the focus control circuit; When the objective lens arranged in the optical path is identified as the second objective lens, a control signal from the tracking control circuit is supplied to the first coil instead of the second coil. Switching means for supplying a control signal from the focus control circuit to the second coil in place of the first coil. 8. An optical lens for irradiating an optical information recording medium with a light beam in an optical path of the light beam to focus the light beam on a track of the optical information recording medium on which information is recorded. In an information processing apparatus, a light beam suitable for a first optical information recording medium is converged in an information processing apparatus which is brought into a focused state by following the light beam in the focused state. A lens, a second objective lens for condensing a light beam suitable for a second optical information recording medium different from the first optical information recording medium, and the first and second objective lenses. A lens holder for holding the lens holder at a position where the distance from the optical axis center of the first objective lens is equal to the distance from the optical axis center of the second objective lens, and the first and second Optical axis of objective lens A rotation axis along the direction, and by pivotally supporting the lens holder so as to be able to rotate around the rotation axis and to move in the direction of the rotation axis, the first and second objective lenses are supported. A lens holder support that supports any one of them in the optical path of the light beam and movably in the optical axis direction; a first coil disposed in the lens holder; and the first objective lens. When the second objective lens is disposed in the optical path of the light beam, the second objective lens is disposed in the lens holder when the second objective lens is disposed in the optical path of the light beam. A first magnet disposed at a predetermined position of the lens holder support opposed to the two coils, and the first objective lens is provided by the lens holder support via the lens holder. Placed in the beam path The first electromagnetic driving means for finely moving the lens holder along the optical axis of the first objective lens to control the first objective lens in the in-focus state, A coil and, when the first objective lens is arranged in the optical path of the light beam, facing the second coil, and the second objective lens is arranged in the optical path of the light beam. And a second magnet disposed at a predetermined position of the lens holder support facing the first coil, and the first objective is provided by the lens holder support via the lens holder. While the lens is placed in the optical path of the light beam, the lens holder is slightly rotated to control the first objective lens to the tracking state, and the lens holder performs tracking. A second electromagnetic driving means for arranging the second objective lens in the optical path of the light beam in place of the first objective lens by being rotationally driven beyond the working range, the second coil and the second coil The first objective is constituted by a first magnet, the lens holder is supported by the lens holder support, and the second objective lens is disposed in an optical path of the light beam. A third electromagnetic driving means for finely moving along the optical axis of the second objective lens to control the second objective lens in the focused state; and the first coil and the second magnet. The second objective lens is slightly rotated while the second objective lens is disposed in the optical path of the light beam by the lens holder support via the lens holder, and the second objective lens is rotated. Lens The first objective lens is arranged in the optical path of the light beam in place of the second objective lens by controlling the lens tracking state and rotating the lens holder beyond the tracking operation range. Fourth electromagnetic drive means, a reflection means arranged at a predetermined position of the lens holder and reflecting light, and the reflection means when the first objective lens is arranged in an optical path of the light beam. When the second objective lens is disposed in the optical path of the light beam, the second objective lens is disposed at a predetermined position on the lens holder support that is not opposed to the reflection unit, and emits light. Detecting means for detecting the reception of the reflected light generated from the reflection means; and detecting the reception of the reflected light from the reflection means by the detection means. An object lens disposed in the optical path of the light beam is identified as a first objective lens, and is disposed in the optical path of the light beam when the detection unit does not detect the reception of the reflected light from the reflection unit. Identification means for distinguishing the objective lens from the second objective lens, and the light beam is focused by one of the first and second objective lenses disposed in the optical path of the light beam A tracking control circuit that supplies a control signal for performing tracking control of the one objective lens to the first coil or the second coil based on reflected light from an optical information recording medium; Of the first and second objective lenses, based on the reflected light from the optical information recording medium in which the light beam is focused by one of the objective lenses arranged in the optical path of the light beam, A focus control circuit that supplies a control signal for performing focus control of the object lens to the first coil or the second coil; and an objective lens arranged in an optical path of the light beam by the identification unit. When identified as the first objective lens, a control signal from the tracking control circuit is supplied to the second coil and a control signal from the focus control circuit is supplied to the first coil. If the objective lens arranged in the optical path of the light beam is identified as the second objective lens by the identification means, the first coil is replaced with the second coil. The control signal is supplied from the focus control circuit to the second coil instead of the first coil while supplying a control signal from the tracking control circuit. The information processing apparatus characterized by comprising a switching means for supplying a control signal.