JPH0561686B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention irradiates a laser beam emitted from a laser light source such as a semiconductor laser onto an optical disk on which information signals such as music audio signals and video signals are recorded. The present invention relates to an optical disc player that reads and reproduces the above information signals.

[Conventional technology]

The optical disc player has a disc table rotationally driven by a spindle motor,
An optical disk is mounted on the disk table and rotated, and an optical pickup device containing a semiconductor laser is operated from the inner circumferential side to the outer circumferential side of the optical disk in the normal direction of the recording track formed on the optical disk. A laser beam emitted from the semiconductor laser is irradiated perpendicularly from the lower surface of the optical disk to track a recording track, and a predetermined information signal recorded on this recording track is read and reproduced. It is configured as follows.

On an optical disk, which is a signal recording medium used in an optical disk player with such a configuration, information signals such as audio signals are pulse-coded and recorded at high density as a row of pits with minute irregularities, so musical sounds cannot be reproduced. The standard size for so-called compact disks that record signals is one with a diameter of 12 cm. As described above, since the optical disk as a recording medium used in an optical disk player for musical sound reproduction is of a small diameter, attempts have been made to make the optical disk player itself that plays it smaller and thinner. As shown in FIG. 1, it has been considered that the inner circumferential shape of an exterior housing 1 is reduced to a rectangular size such that the outer circumferential diameter of an optical disk 2 substantially forms an inscribed circle. Furthermore, in order to make the optical disc player thinner, an optical pickup device 3 constructed as shown in FIG. 2 is used. This optical pickup device 3 focuses a laser beam and irradiates the signal recording surface of the optical disk 2 perpendicularly to the optical axis of an objective lens 4. The laser beam is parallel to the semiconductor laser 6
The laser beam is deflected by 90 degrees by a reflecting mirror 7 and guided to the objective lens 4 via a 1/4 wavelength plate 8. Therefore, in this optical pickup device 3,
A semiconductor laser 6 is attached to the end of a base 18 as a mounting base so that the laser beam is emitted in a direction perpendicular to the optical axis of the objective lens 4, and the laser beam is used as a main beam for signal reading and a tracking servo. A diffraction grating 9 that separates the light into two sub-beams, a beam splitter 10 that separates and directs the return light reflected from the optical disk 2 to the photodetector 12, a collimating lens 11 that controls the laser beam into parallel light, etc. An optical system block is assembled into the base 18 so that its optical axis is orthogonal to the optical axis of the objective lens 4. Further, an intermediate lens 13 and a cylindrical lens 14 guide the returning laser beam to the photodetector 12 after reading the information signal reflected from the optical disk 2 and recorded on the optical disk 2, which is reflected in a 90 degree direction by the beam splitter 10. The optical system block consisting of the following components is also incorporated into the base 18 so that the optical axis thereof is perpendicular to the optical axis of the objective lens 4. The optical pickup device 3 configured so that the laser beam emitted from the semiconductor laser 6 enters the objective lens 4 in a direction perpendicular to the optical axis of the objective lens 4 is configured to allow the laser beam to enter the objective lens 4 from the direction of its optical axis. It can be made sufficiently thinner than those with
An optical disk player equipped with this optical pickup device 3 can also be made thinner.

[Problem to be solved by the invention]

As mentioned above, it is conceivable that the exterior housing 1 is made smaller and the optical pickup device 3 disposed within this exterior housing 1 is made thinner, thereby making the entire device smaller and thinner. As shown in FIG.
The recording track is recorded with a laser beam transmitted from the objective lens 4 from the inner circumference side to the outer circumference side of the optical disk 2 mounted on the disk table. The recording track is configured to trace and obtain information signals recorded on the recording track. That is, the optical pickup device 3
The optical axis of the objective lens 4 is aligned with the center line of the optical disk 2 placed on the disk table through a pair of guide shafts 16 and 17 arranged parallel to the disk table. It is configured to be transferred by a transfer means consisting of, etc.

Incidentally, in the optical pickup device 3, the recording track is positioned within the focal depth of the laser beam that is focused by the objective lens 4 and irradiated onto the recording track of the optical disk 2, and the laser beam is positioned precisely in the tracking direction of the recording track. A two-axis drive device for the objective lens 4 is provided for servo-controlling the objective lens 4 in two mutually orthogonal axes directions, the focusing direction and the tracking direction, so that In this two-axis drive device, an objective lens 4 is attached to a magnetic gap in a magnetic circuit section, and a bobbin with a drive coil provided on the proximal end is inserted and supported, and error signals in the focus direction and tracking direction are applied to the drive coil to adjust the focus and the tracking direction. It is configured to perform tracking control. In the two-axis drive device configured in this manner, the magnetic circuit section is disposed so as to surround the objective lens 4, so that the mounting portion of the objective lens 4 of the optical pickup device 3 becomes large. Therefore, when the optical pickup device 3 is moved to a position for reading the recording track on the outermost circumferential side of the optical disk 2, the two-axis drive device is housed at least from the center of the objective lens 4, as shown in FIG. The base 18 protrudes outward from the outer periphery of the optical disk 2 by a length l extending over one side. Also, 2
Even if the axial drive device is downsized and configured to have approximately the same diameter as the outer shape of the objective lens 4, the relationship between the beam spot diameter of the laser beam on the recording surface of the optical disk 2, the focal length of the objective lens 4, etc. Therefore, an objective lens 4 having a diameter of at least 5 to 6 mm is required, and when the optical pickup device 3 is moved to the position where the outermost recording track of the optical disk 2 is read as described above, the radius of the objective lens 4 is One side of the base 18, which includes the base 18 and supports the objective lens 4, protrudes outward from the outer periphery of the optical disk 2. Therefore, the length l of the optical pickup device 3 in the transport direction of the exterior housing 1 needs to be larger than the diameter of the optical disk 2 by the length l of the protrusion of the optical pickup device 3 from the outer periphery of the optical disk 2. There is. As a result, it is not possible to downsize the exterior casing 1 to the size of a rectangle whose inscribed circle is the outer diameter of the optical disk 2, making it impossible to miniaturize the optical disk player to the maximum size. ing.

In addition, the optical pickup device has an objective lens 4.
Since the center of the optical disk 2 is moved in the direction passing through the center of the optical disk 2, the base 18, which serves as a mounting base for storing and holding an optical system block like the optical pickup device described above, is simply If it is rectangular and linear, the amount of protrusion to the outside of the optical disc 2 will increase when it is fed to the outermost circumference of the optical disc 2, making it impossible to downsize the player.

Furthermore, if the base 18 is simply rectangular and linear, the photodetector 12 that detects the returned light beam when the optical components constituting the optical system block are arranged as shown in FIG.
It is necessary to arrange the objective lens 4 in a direction protruding laterally from the center of the optical disk 2. If the width of the optical pickup device 3 increases, the center of the objective lens 4 will be obstructed by the disk rotation drive device and the center of the objective lens 4 will not be able to reach the innermost circumferential side of the optical disk 2. It becomes impossible to read the information signal.

Therefore, the present invention provides a system that can reliably reach the innermost circumference of the optical disk even when the outer casing is miniaturized to the size of a rectangle whose inscribed circle is the outer circumferential diameter of the optical disk. This was proposed for the purpose of providing an optical disc player that can read information signals and further reduce the size of the device.

[Means to solve the problem]

In order to achieve the above-mentioned object, an optical disc player according to the present invention has a disc mounting part on which an optical disc is placed, and a disc player that rotationally drives the optical disc placed on this mounting part. a rotary drive means; an objective lens drive means for driving the objective lens in a direction parallel to its optical axis and in a direction perpendicular to the optical axis; a beam splitter for separating the light beam emitted from the light source and the return light beam via the objective lens from the optical disk placed on the disk mounting section; A photodetector for receiving the returned light beam separated by the beam splitter, at least the objective lens drive means, the light source, the beam splitter, and the optical path deflection means are attached, and the disk rotation drive means and an optical pickup device having a base bent along the outer circumferential surface of the optical disk, the optical pickup device being movable over the inner and outer circumferences of the optical disk placed on the disk mounting section, the objective lens driving means is a position that does not come into contact with the disk mounting section when the optical pickup device moves to a position corresponding to the innermost circumference of the optical disk mounted on the disk mounting section, and the objective lens is disposed on the base at a position that moves in the radial direction of the optical disk.

[Effect]

The optical pickup device constituting the optical disk player according to the present invention has a structure in which the light beam emitted from the light source is polarized by 90 degrees in the optical path and guided to the objective lens. The optical axis of is parallel to the surface of the optical disk.

Further, in the optical pickup device, the bent portion of the base on which the optical system block is attached is arranged along the circumferential surface of the disk rotation driving means, and the bent portion of the base on which the optical system block is attached is aligned with the innermost circumference of the optical disk on the disk rotation driving means. be moved to the corresponding position.

〔Example〕

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

As shown in FIGS. 3 and 4, the optical disc player according to the present invention has an inner peripheral shape of an exterior casing 21 constituting the player body, and an outer peripheral diameter R of an optical disc 22 to be played by this player. It is formed into a rectangular shape that forms an inscribed circle, that is, one side of the inner peripheral edge of the exterior housing 21 has a length approximately equal to the diameter of the optical disk 22. On the front side exterior wall portion 23 of the exterior housing 21 formed in this way, a power switch operation button 24 and a play/pause button 2 are provided.
5. Operation buttons such as a next song selection button 26, a fast forward operation button 27, a designated song selection button 28, a reverse operation button 29, and an eject button 30 are provided, as well as a timer or a display section 31 for the address of the performance song.

In the center of the exterior housing 21, there is an optical disk 2.
A disk rotation drive mechanism that performs rotational drive of No. 2 is disposed. This disk rotation drive mechanism is arranged such that the axis of a spindle 33 is aligned with the approximate center of the exterior housing 21, and a disk table 32 on which the optical disk 22 is placed is attached to the tip side of the spindle 33. .

The spindle 33 is mounted on a bearing 3 attached to the lower surface side of the chassis board 34 as shown in FIG.
5 and is rotatably supported, and the tapered base end 33a is supported and attached to a thrust bearing 36 which is also attached to the bottom surface of the chassis base plate 34 so as to hang down. A disk plate 37 made of metal and formed into a disk shape is integrally fitted to the base end side of the spindle 33 mounted in this manner. An elastic ring 39 made of an elastic material such as rubber is fitted into a fitting part 38 which is formed by cutting out the outer peripheral part of the upper surface of the disk plate 37 in a stepped manner, facing the disk table 32. . The upper surface of this elastic ring 39 is formed into a tapered drive wheel contact surface 40, and a drive motor 42 is attached parallel to the surface of the optical disk 22 via a motor support member 41 attached to the lower surface side of the chassis board 34. A drive wheel 45 is attached to a drive shaft 44 connected to the output shaft via a reduction gear mechanism 43 and has an outer circumferential surface tapered to correspond to the drive wheel rotation contact surface 40, and rotates the drive motor 42. The driving force is transmitted to the spindle 33.

In this way, the drive motor 42 is mounted on the upper surface of the disk plate 37 attached to the base end side of the spindle 33.
By adopting a so-called disk drive method in which the drive wheel 45 driven by the spindle 33 is driven by rolling contact, the drive motor 42 has an output shaft parallel to the surface of the optical disk 22 mounted on the disk table 32. Since it can be attached, the spindle drive mechanism can be made thinner, which in turn contributes to making the optical disc player thinner.

Note that the drive method for the disk table 32 is not limited to the above-described disk drive method, but may also employ a so-called direct drive method in which the spindle 33 is directly connected to the output shaft of a drive motor.

Inside the exterior casing 21 in which the disk table 32 is disposed as described above, the disk table 33 is installed.
An optical pickup device 46 irradiates the signal recording surface of the optical disk 22 mounted above with a laser beam and reads and operates information signals such as musical tone signals recorded on the optical disk 22. Mounted facing the signal recording surface. This optical pickup device 46 is
It includes a front side exterior wall 23 provided with various operation buttons of the exterior casing 21, a rear side exterior wall 48 parallel to this front exterior wall 23, and opposite side exterior walls 4.
9,50 at an inclined angle to the optical disk 2.
It is mounted so that it can be operated in a radial direction around the rotation center of No. 2 from the inner circumferential side to the outer circumferential side.

Incidentally, in order to reduce the thickness of the optical pickup device 46 used in the present invention, the laser beam is directed toward the objective lens 47, similar to that used in the optical disk player shown in FIGS. 1 and 2 described above. It is configured so that the light is incident from a direction perpendicular to the optical axis _OR . That is, as shown in FIGS. 7, 8, and 9, the semiconductor laser 51 as a light source is arranged so that the laser beam emitted from the semiconductor laser 51 is emitted in a direction perpendicular to the optical axis _OR of the objective lens 47. A diffraction grating 54 and an optical disk 2 are attached to the end of the base 52 as a support base and separate the laser beam into a main beam for signal reading and two sub-beams for tracking servo.
a beam splitter 56 that reflects the laser beam reflected from 2 to a photodetector 55, and a collimating lens 5 that polarizes the laser beam into parallel light.
7, etc., is assembled into the base 52 so that its optical axis O _L is orthogonal to the optical axis O _R of the objective lens 47. In addition, the beam splitter 5
A semicylindrical cylinder that reads the information signal recorded on the optical disk 22 and is refracted in a 90-degree direction by the optical disk 22 and reflected from the optical disk 22, and guides the returned light to a photodetector and astigmatizes the returned light. The optical axis O _P of the optical system block on the return light side consisting of the lens 59 is also incorporated into the base ₅₂ so that it is perpendicular to the optical axis OR of the objective lens 47 . The laser beam emitted from the semiconductor laser 51 has an optical path deflected by a reflecting mirror 60 attached to the lower surface side of the objective lens 47 in the direction of 90 degrees, and then rotates its polarization axis by 45 degrees. Board 61
The light is perpendicularly incident on the objective lens 47 through.

Also, an objective lens 47 that focuses the laser beam emitted from the semiconductor laser 51 and irradiates it perpendicularly to the signal recording surface of the optical disk 22, or transmits the return light reflected from the signal recording surface.
is a two-axis driving device 65 serving as an objective lens driving means for driving the objective lens 47 in two mutually orthogonal directions: a focus direction, which is the optical axis direction, and a recording track tracking direction, which is orthogonal to the optical axis direction. It is supported and incorporated into the base 52. The objective lens 47 is supported by a two-axis drive device 65 to control focus so that the recording track is located within the focal depth of the laser beam, and to control the laser beam so that it accurately traces the recording track. Tracking control is performed.

By the way, an optical system block consisting of a semiconductor laser 51, a beam splitter 56, a reflecting mirror 60, etc.
The base 52 serves as a support base for the objective lens 47 and the two-axis drive device 65 for displacing and driving the objective lens 47 in two axis directions perpendicular to each other.
As shown in FIG. 7, it is bent into a substantially doglegged shape. That is, the base 52 is connected to the exterior housing 21.
When the disk table 32 is disposed inside the disk table 32, a substantially dogleg-shaped bent portion 52 whose surface facing the disk table 32 surrounds the circular outer circumferential side of the disk table 32.
It is considered as a. A biaxial drive device 65 including an objective lens 47 is arranged at the bent tip side portion of the base 52.

The two-axis drive device 65 used here is
For example, one configured as shown in FIG. 10 is used. The two-axis drive device 65 shown in FIG. 10 has a fixed part 66 that constitutes a magnetic circuit part forming a magnetic gap, and a support shaft 67 that is mounted on this fixed part 66 and rotates around the axis. It is composed of a movable part 68 that is attached freely and slidably in the axial direction. The fixed part 66 constituting this magnetic circuit part is connected to the base 52 in which the optical system is installed.
a mounting board 69 serving as a mounting plate for the mounting board 69, a ring-shaped magnet 70, integral inner circumferential yokes 72, 73 having a fan-shaped cross section and facing each other so as to be integrally planted on the mounting board 69, and a ring-shaped magnet 70. Inner circumferential yokes 72 and 73 are provided facing each other so as to be integrally planted on the yoke mounting portion 74, and second yokes 77 and 78 are placed facing each other and are mounted on the mounting substrate 71. It is composed of a support shaft 67. A mounting board 7 integrally has a pair of fan-shaped inner yokes 72 and 73 facing each other.
1, one of the notches 79 and 80 formed between the inner circumferential yokes 72 and 72 is provided.
An optical window 81 is provided in communication with the base 52, through which a laser beam from the semiconductor laser built in the base 52 described above passes. Further, a ring-shaped magnet 70 is disposed so as to fit into the base end portions of the inner circumference side yokes 72 and 73, and this magnet 7
A pair of outer circumferential yokes 77 and 78 are attached to the upper side of 0 with a yoke attaching portion 74 provided therein. Note that the outer circumferential yokes 77 and 78 are formed to have a length of one-fourth of the outer circumferential surface of the yoke attachment portion 74,
and are arranged opposite to each other. Therefore, a pair of notches are formed between the pair of outer peripheral yokes 77 and 78. As shown in FIG. 11, these pair of outer circumferential yokes 77, 78 are attached to face the inner circumferential yokes 72, 73, respectively, and form magnetic gaps 82, 83 to constitute a magnetic circuit section. are doing. Further, a damper holder 85 made of an elastic material and having a support hole 84 bored in the central part on the base end side has a pair of leg pieces 85a and 85b formed in the upper end surface of the inner circumferential yokes 72 and 73.
The fitting holes 84a and 84b are engaged with the fitting holes 2a and 73a, so that the fitting holes 84a and 84b are engaged with each other. This damper 8
5 is a notch 7 of the first yoke 72, 73;
9 and 80, it faces the center of a notch 80 on the opposite side to the notch 79 in which the above-mentioned optical window 81 is provided. Further, a support shaft 67 is vertically installed in the center of the mounting board 69.

The support shaft 67 has a bearing 8 of the movable part 68.
6 is rotatably inserted as shown in FIG. That is, the movable part 68 has a disc shape that is slightly larger than the outer periphery of the inner yokes 72 and 73, and a bulge 88 is integrally formed in the diametrical direction of the center of the movable part 68. A bearing fixing hole 89 is provided vertically in the axial center of the shaft. The upper end of the bearing 86 is inserted into this fixing hole 89 and fixed. Further, a lens hole 90 is perpendicularly formed in one end of the bulging portion 88 of the movable portion 68 . A lens frame 92 into which the objective lens 47 is fitted is inserted into the lens hole 90 and attached. Here, the optical window 81 is located directly below the objective lens 47,
The laser beam from the optical window 81 reaches the inner yoke 72,
The objective lens 47 passes through the notch 79 between the
It is designed to be guided by.

Further, the upper end of a support pin 93 is vertically implanted at the other end of the bulge 88 of the movable part 68 from the back side of the movable part 68 (lower side in FIG. 10). The lower end of the pin 93 is inserted into the support hole 84 of the damper holder 85 and fixed.

The movable part 68 mounted as described above has a skew winding mechanism that rotates the movable part 68 in the radial direction with respect to the support shaft 67 and controls tracking of the objective lens 47 in the normal direction of the recording track of the optical disk 22. Tracking drive coil 9
4 is attached via a cylindrical bobbin 95. A focus drive coil 96 is wound in regular rows on the tracking drive coil 94 to control the focus in the laser beam focus direction, which is the optical axis direction of the objective lens 47, by sliding the movable part 68 in the thrust direction. installed. The two-axis drive device 65 installed as shown in FIGS. 11 and 12 drives the objective lens 47.
It is covered with a cap 99 having an elongated hole 98 facing into it.

Two-axis drive device 6 configured as described above
5, the focus direction of the objective lens 47 is controlled by astigmatizing the return light reflected from the signal recording surface of the optical disk 22 through a cylindrical lens 59 disposed within the base 52 of the optical pickup device 46. , photodetector 55 divided into four parts
A focus control signal corresponding to the difference in the detection output from each detection section of each divided photodetector 55 is obtained, and a drive current corresponding to this focus control signal is supplied to the focus drive coil 96, and the objective lens This is done by driving the movable part 68 to which the movable part 47 is attached in the thrust direction.

Further, the tracking direction of the objective lens 47 is controlled by converting the laser beam emitted from the semiconductor laser disposed in the base 52 into one main beam and two sub beams for reading the recorded track using the diffraction grating 54. On the signal recording surface of the optical disk 22, the main beam spot S obtained by the main beam as shown in FIG.
The sub-beam spots S2 and S3 obtained by the sub-beams are lined up in the tangential direction of the recording track T with the sub-beam spots S2 and S3 slightly shifted to the left and right across the recording track T, and the sub-beam spots S2 and S3 obtained by the two sub-beams are recorded. A photodetector detects the amount of reflection of the sub-beams from the pits P2 and P3 constituting the track, and a tracking control signal is obtained in accordance with the difference in detection output obtained from each sub-beam. Then, a drive current corresponding to this tracking control signal is supplied to the tracking drive coil 94, and the movable part 68 to which the objective lens 47 is attached is driven in the radial direction around the support pin 93, so that the main beam spot S1 by the main beam is It is positioned over the pits constituting the recording track and is controlled to trace the recording track accurately.

Optical pickup device 4 configured as described above
6 is a two-axis drive device 65 in which an objective lens 47 whose external shape becomes large when the optical disk 22 is moved so as to trace the outermost recording track of the optical disk 22 is movably supported in two axes. The optical axis between the beam splitter 56 and the reflecting mirror 60 is located at a corner formed by the rear exterior wall 48 of the housing 21 and one side exterior wall 49 perpendicular to the rear exterior wall 48 of the housing 21. The optical disk 22 is placed on the disk table 32 so that the laser beam is substantially parallel to the rear exterior wall 48.
The semiconductor laser 51 is arranged in the exterior housing 21 so that the semiconductor laser 51 emits light parallel to the surface and parallel to the rear exterior wall 48 .

By the way, tracking of recording tracks by a laser beam irradiated onto the signal recording surface of the optical disk 22 through the objective lens 47 traces all the recording tracks from the inner circumference side to the outer circumference side of the optical disk 22. It is necessary to perform this in the normal direction of the recording track. Therefore, the optical pickup device 46 arranged as described above is moved inside the exterior housing 21 so that the objective lens 47 is transported in the normal direction of the recording track, that is, in the radial direction passing through the center of the optical disk 22. mounted on. That is, the optical pickup device 46 has a pair of guide shafts 10 mounted on the chassis substrate 34 in parallel to the direction in which the objective lens 47 is to be transported.
1 and 102, the recording tracks of the optical disk 22 are moved from the inner circumferential side to the outer circumferential side by being attached to the base 52 by inserting slide bearings 54 and 55 that are fitted into the base 52 and being guided and transferred by the guide shafts 101 and 102. Track everything from side to side.

As described above, the pair of guide shafts 101 and 102 that guide the optical pickup device 46 disposed inside the exterior housing 21 and operated for transfer are attached at an angle with respect to the rear side exterior wall 48. In this case, it is mounted on the chassis board 34 with an inclination angle θ of approximately 45 degrees.

By transporting the optical pickup device 46 at an angle with respect to the rear side exterior wall portion 48 of the exterior housing 21, the optical axis of the objective lens 47 reaches the outermost recording track of the optical disk 22. The two-axis drive device 65, which becomes large when mounted, is connected to the rear side exterior wall portion 48 and one side exterior wall portion 4.
9, it can be positioned protruding from the inner circumferential side of the optical disk 22 without increasing the size of the rectangular exterior housing 21 whose inscribed circle is the outer circumferential edge of the optical disk 22. Tracking operations can be performed on the recording track on the outer circumference side.

Note that the pair of guide shafts 101 and 102 are as follows:
The mounting piece 103 is formed by cutting and bending a part of the chassis board 34, and the mounting piece 103 is installed by being inserted and supported at both ends through the insertion holes. The other guide shaft 102 is mounted in such a manner that it can absorb mounting errors with respect to the one guide shaft 101 and machining precision errors of the bearing of the optical pickup device 46. be installed in such a way as to be adjustable.

As described above, the optical pickup device 46 is slidably attached to the pair of guide shafts 101 and 102, which are arranged at an angle with respect to the rear exterior wall 48, via slide bearings 104 and 105. The inner periphery of the optical disk 22 is driven by a pickup drive motor 108 that is attached to the lower surface of the chassis board 34 via a motor support member 107 so as to be parallel to the exterior wall 49 on one side of the exterior housing 21. The running operation is performed from the side to the outer circumference. This pick-up drive motor 108
The optical pickup device 46 includes the worm gear 109 attached to the output shaft 106 of the drive motor 108 and the base 52 of the optical pickup device 46.
First, second and third gears are meshed with each other and constitute a deceleration mechanism between the racks 110 mounted on one side so as to be parallel to the guide shafts 101, 102.
are connected by a connecting gear mechanism 114 consisting of gears 111, 112, and 113, and the driving force of the pick-up drive motor 108 is decelerated and transmitted to the optical pick-up device 46, so that the optical pick-up device 46 is operated to travel. has been done.

By the way, the tracking direction of the objective lens 47 incorporated in the optical pickup device 46 is controlled so that the main beam accurately traces the recording track according to the movement of the optical pickup device 46. It is necessary to do this in the normal direction. Therefore, the tracking control of the objective lens 47 is
It is necessary to perform the recording in the normal direction of the recording track, that is, in the direction toward the center of the optical disk 22 and in the opposite direction. Therefore, the two-axis driving device 65 built in the optical pickup device 46 is configured to operate the objective lens 47 variably in the direction of the center of the optical disk 22 and in the opposite direction, that is, in the direction of movement of the optical pickup device 46. It is incorporated into the optical pickup device 46 so as to be tracking controlled.

Therefore, in the optical pickup device 46 used in the present invention, an optical system consisting of a diffraction grating 54, a beam splitter 56, a collimating lens 57, etc. is attached to the rear exterior wall 48 with the optical axis parallel to the optical pickup device 46. Objective lens 4 is attached to the optical axis of the block.
The direction of the tracking control in No. 7 is set at an acute angle of approximately 45 degrees.

In addition, in the case of the optical pickup device 46 which performs tracking control using the three-spot method as described above, two sub-beam spots S2 are located in the tangential direction of the recording track T with the main beam spot S1 in between, as shown in FIG. , S3, the objective lens 47 is controlled in the tracking direction according to the difference in detection outputs obtained from the main beams. must be located in a direction perpendicular to the direction of transport.

Therefore, the moving direction of the objective lens 47 is aligned with the pair of guide shafts 1 relative to the optical axis of the optical system block consisting of the diffraction grating 54 that controls the laser beam emitted from the semiconductor laser 51, the beam splitter 56, etc.
In the case of the optical pickup device 46 which is tilted by the angle θ at which 01 and 102 are tilted with respect to the rear side exterior wall portion 48, the direction of the grating pattern 54a of the diffraction grating 54 that separates the laser beam into three beams. As shown in FIG. 14, the base 5 is tilted by the angle θ with respect to the optical axis P1 of the optical system block.
When the three separated laser beams are refracted by the reflecting mirror 61 and irradiated onto the surface of the optical disk 22 through the objective lens 47, connecting the two beam spots S1, S2, and S3, these beam spots S1, S2, and S3 are arranged in a direction perpendicular to the direction in which the objective lens 47 is moved.

In addition, the cylindrical lens that astigmatizes the three return lights reflected from the surface of the optical disk 22 and guides them to the photodetector, and the photodetector that reads the detection output from the laser beam are also aligned to the optical axis by the angle θ. Tilt against the opposite direction.

Furthermore, since the direction of oscillation and diffusion of the laser beam in the semiconductor laser 51 differs depending on the direction of the light emitting region surface, the direction of the light emitting region surface is tilted by the angle θ which is the angle θ which is the angle at which the diffraction grating 54 is tilted as described above. Installed.

In the optical disk player as described above, in which the optical pickup device 46 is transported at an acute angle with respect to the rear side exterior wall portion 48 of the rectangular exterior housing 21, the optical pickup device 46 is provided with a The tracking control direction of the objective lens 47 is set relative to the optical axis between the beam splitter 56 and the reflecting mirror 61 in the optical pickup device 4.
By tilting it in accordance with the tilt angle with respect to the rear side exterior wall portion 48 in the transport direction of No. 6, and performing the tilting toward the center of the optical disk 22 and in the opposite direction,
Accurate tracking control can be performed at any position from the inner circumferential side to the outer circumferential side of the optical disk 22.

Further, when the optical pickup device used in this optical disk player is transferred to the innermost circumferential side of the optical disk 22 placed on the disk table 32, the base 52 to which the two-axis drive device 65 etc. are attached is bent. As shown in FIG. 15, the portion 52a is positioned so as to surround the outer circumferential side of the disk table 32, and the optical axis center of the monster lens 47 faces the recording track on the innermost circumferential side of the optical disk 22. Become. That is, the optical axis center of the objective lens 47 can be reliably moved to the innermost circumference of the optical disk 22 without a part of the base 52 coming into contact with the outer circumference of the disk table 33.

In the above-described embodiment, the optical pickup device 46 is mounted on the rear side exterior wall portion 4 of the exterior housing 21.
However, when the optical axis of the objective lens 47 reaches the outermost recording track of the optical disk 22, the outermost recording track of the optical disk 22 is moved. 2 protruding from the periphery
A part of the shaft drive device 65 is an optical device formed by the rear side exterior wall 48 and the side exterior wall 49 of the exterior housing 21, which is formed into a rectangular shape with the outer peripheral edge of the optical disk 22 as an inscribed circle. As long as the disk 22 is positioned at a corner where it does not face, the inclination angle θ can be appropriately selected. Furthermore, it is desirable that the electric circuit components housed inside the exterior housing 21 be made as small as possible to take up a large space for installing mechanical components.

In the optical disc player of the above-described embodiment, a lid is provided on the inner surface that covers the upper surface side of the disc table 32 and is provided with a chucking device that works together with the disc table 32 to clamp and support the optical disc 22. The body is attached to the exterior casing 21 so as to be openable and closable.

〔Effect of the invention〕

As described above, the optical disc player according to the present invention follows the optical path of the light beam emitted from the light source.
The player uses an optical pickup device configured to deflect the light by 90 degrees and guide it to the objective lens, and to make the optical axis of the optical system block from the light source to the optical path deflecting means parallel to the surface of the optical disk. The device itself has been made thinner.

Further, since the objective lens driving means, light source, beam splitter, and optical path deflection means constituting the optical pickup device are arranged on a base bent along the outer periphery of the disk rotation driving means, the optical pickup device described above The player itself can be miniaturized while sufficiently guaranteeing a movement range covering the inner and outer peripheries of the optical disk.

Further, the objective lens driving means is moved to a position on the base bent along the outer periphery of the disk rotation driving means, and the optical pickup device corresponds to the innermost periphery of the optical disk placed on the disk mounting section. Since the objective lens is placed at a position where it does not come into contact with the disk mounting section when the lens is moved, and where the locus of movement of the objective lens coincides with the radial direction of the optical disk, it can be easily moved to the innermost circumferential position of the optical disk. This makes it possible to read information signals recorded on the optical disk. In other words, even when the optical pickup device is moved to the innermost circumferential side of the optical disk, the objective lens driving means does not come into contact with the disk mounting section, so the vibrations generated when the objective lens is driven are transmitted to the optical disk. The rotation of the optical disc is stable without being transmitted to the
Furthermore, it realizes stable control of the objective lens, making it possible to read information signals with good quality. Furthermore, since the movement locus of the objective lens, which is drive-controlled by the objective lens driving means, is arranged at a position that coincides with the radial direction of the optical disk, accurate tracking control can be performed to adjust the movement of the objective lens to the inner and outer peripheries of the optical disk. Information signals from all recording areas can be reliably read out.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an optical disc player, which is the premise of the present invention, and FIG. 2 is a schematic sectional view showing an optical pickup device used in the optical disc player. FIG. 3 is a tilted view showing the optical disc player according to the present invention, and FIG.
The figure is a plan view thereof, and FIG. 5 is a bottom view thereof. FIG. 6 is a side view showing a disk drive mechanism used in the optical disk player. 7th
The figure is a plan cross-sectional view schematically showing the internal structure of the optical pickup device used in the present invention, FIG. 8 is a cross-sectional view taken along the line A--A in FIG.
It is a sectional view taken along the line BB in the figure. FIG. 10 is an exploded oblique view showing the two-axis drive device built into the optical pickup device, FIG. 11 is a side sectional view thereof, and FIG. 12 is a sectional view taken along line A-A in FIG. 11. , FIG. 13 is an enlarged plan view showing the tracking error detection state by the three-spot method.
FIG. 14 is a diagram illustrating how the diffraction grating is attached. FIG. 15 is a plan view of the optical pickup device transferred to the innermost circumferential side of the optical disk. 21...Exterior housing, 32...Disk table, 4
6...Optical pickup device, 47...Objective lens,
48...Back side exterior wall part, 51...Semiconductor laser, 5
2... Base, 52a... Bent portion of base, 56... Beam splitter, 60... Reflector, 65... Two-axis drive device, 101, 102... Guide shaft, 108
...Pickup drive motor.

Claims (1)

[Scope of Claims] 1. A disk rotation drive means having a disk mounting portion on which an optical disk is placed, and a disk rotation driving means for rotationally driving the optical disk placed on the mounting portion, and an objective lens having an optical axis thereof. objective lens driving means for driving in parallel directions and in directions perpendicular to the optical axis; optical path deflection means for deflecting the optical path of the light beam emitted from the light source by 90 degrees and guiding it to the objective lens; a beam splitter that separates the returned light beam from the optical disk placed on the disk mounting section and the returned light beam that passes through the objective lens; and a returned light beam separated by the beam splitter. a photodetector for receiving light, and a base to which at least the objective lens drive means, the light source, the beam splitter, and the optical path deflection means are attached, and which is bent along the outer peripheral surface of the disk rotation drive means. and an optical pickup device that is movable over the inner and outer peripheries of the optical disk placed on the disk mounting section, and the objective lens driving means is configured such that the optical pickup device a position where the objective lens does not come into contact with the disk mounting portion when moved to a position corresponding to the innermost circumference of the optical disk placed on the optical disk, and a position where the objective lens moves in the radial direction of the optical disk; An optical disc player characterized in that the optical disc player is located on the base.