JPH08111076A - Assembling method for optical pickup device and recording and reproducing device for disk-shaped recording medium - Google Patents

Abstract

PURPOSE: To make it possible to stop an optical pickup device with high accuracy and to detect the reading start position of a disk-shaped recording medium with high accuracy at the time when this optical pickup device moves to the innermost circumferential part of the disk-shaped recording medium. CONSTITUTION: The optical axis of an objective lens 8 is adjusted to be in the state of butting to the reference plane 7 of a mounting base plate 6 having the reference plane 7 parallel with the optical axis of the objective lens 8 formed one side face part to the reference plane of a jig 28 for adjustment which adjusts the optical axis and thereafter, a bobbin 5 having with the assembled objective lens 8 in it, is mounted at a mounting base plate 6 and the optical pickup device 3 is assembled. The optical pickup device 3 is then mounted at a guide shaft and guide member in such a manner that the device is made freely movable across the inner and outer circumferences of the signal recording region of an optical disk. Further, the reference plane 7 of the mounting base plate 6 is pressed to a stopper member at the time when the optical pickup device 3 moves to the innermost circumferential part of the signal recording region of the optical disk, thereby, the movement of the optical pickup device 3 is stopped and the optical pickup device is assembled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a read-only optical recording medium (hereinafter referred to as a CD-ROM), a rewritable optical recording medium, and a magneto-optical recording medium rewritable by optical modulation or magnetic field modulation. The present invention relates to an assembling method of an optical pickup device used for writing and / or reading an information signal to and from a disc-shaped recording medium, and a recording / reproducing device for the disc-shaped recording medium including the pickup device.

[0002]

2. Description of the Related Art An optical recording / reproducing apparatus such as an optical disc player uses a disc-shaped recording medium such as an optical disc as an optical recording medium for information signals, and records an information signal recorded in a signal recording area of the disc-shaped recording medium. Or the information signal is recorded in the signal recording area of the disc-shaped recording medium.

Some optical discs serving as disc-shaped recording media are provided with a signal recording area in which an information signal can be written, in the inner peripheral portion of the signal recording area. This optical disc, a so-called CD-R, is a read-only CD-
A signal recording area having a width of about 1.8 mm is provided further inside from the innermost peripheral portion of the signal recording area of the ROM. Therefore, a recording / reproducing apparatus using this CD-R as a recording medium is further in a distance of about 1.8 mm as compared with a CD-ROM when recording / reproducing an information signal to / from this CD-R. It is necessary to move the optical pickup device to the periphery.

A recording / reproducing apparatus for an optical disc compatible with CD-R has been proposed by the same applicant. The optical disk recording / reproducing apparatus 20 is configured as shown in FIGS. The optical disc recording / reproducing apparatus 20 shown in FIGS. 5 and 6 roughly includes an optical pickup device 33 that moves an objective lens 38 attached to a bobbin 35 with respect to a signal recording area of the optical disc, and the optical pickup device 33. A guide shaft 45 and a guide member 46, a spindle motor 53 for rotating and driving an optical disk, and a chassis member 51 on which the guide shaft 45, the guide member 46, and the spindle motor 53 are arranged. .

An optical pickup device 33 used in the recording / reproducing device 20 for this optical disc has an objective lens 38 and
A bobbin 35 provided with the objective lens 38, a mounting base 36 on which the bobbin 35 is mounted, a drive unit 41 mounted on the mounting base 36, and a chassis member 51 on which the optical pickup device 33 is mounted. It is composed of a guide shaft 45 and a guide member 46 provided in the.

The chassis member 51 has a guide shaft 45 supported at both ends by a first supporting portion 47A and a second supporting portion 47B, respectively, and the first supporting portion 47A and the second supporting portion 47B. Are provided respectively. Further, in the chassis member 51, both ends of the guide member 46 are supported by the first support portion 48A and the second support portion 48B in parallel with the guide shaft 45, respectively. 48A and 2nd support part 48B
And are provided respectively. The optical pickup device 33 is slidably assembled to the guide shaft 45 and the guide member 46 of the chassis member 51.

The mounting base 36 is formed of a metal material into a substantially rectangular shape, and the bobbin 35 is provided on the main surface thereof. The mounting base 36 has sleeve mounting portions 40A and 40B integrally formed on one end thereof so as to project therefrom.
A sleeve member 54 is provided on these sleeve attachment portions 40A and 40B. And the mounting base 36 is
It is slidably attached to the guide shaft 45 via the sleeve member 54.

A protrusion 55 is formed on the other end of the mounting base 36 adjacent to the bobbin 35, and a support shaft 56 is provided on one side surface of the protrusion 55. The mounting base 36 has a rolling bearing 39 rotatably supported on the support shaft 56, and is slidably mounted on the guide member 46 via the rolling bearing 39.

Further, the mounting base 36 is provided with a drive circuit portion 41 for driving the bobbin 35 on one side surface portion.
The drive circuit section 41 is connected to a power supply section (not shown) via a flexible cable 42. The mounting base 36 is provided with an electromagnetic levitation drive unit 48 adjacent to the guide shaft 45, and a magnetic force is generated in the electromagnetic levitation drive unit 48 by the electric power supplied from the drive circuit unit 41. Further, the guide shaft 4 is attached to the chassis member 51.
The first magnet member 52A and the second magnet member 5 in parallel with
2B and 2B, respectively.

That is, in the optical pickup device 33, the magnetic force generated by the electromagnetic levitation drive section 48 and the first magnet member 52 arranged at a position corresponding to the electromagnetic levitation drive section 48.
It is moved in a levitated state by the repulsive force generated by A and the magnetic force generated by the second magnet member 52B.

The bobbin 35 has an objective lens 38,
It is supported by a shaft actuator so as to be elastically displaceable. That is, the bobbin 35 includes a mechanism for adjusting in the track direction, which is a direction parallel to the signal recording area of the optical disc, and a mechanism for adjusting in the focus direction, which is a direction orthogonal to the signal recording area of the optical disc. ing.

In the optical disc recording / reproducing apparatus 20 configured as described above, the operation of the optical pickup device 33 moving to read the information signal in the signal recording area of the optical disc will be described. The mounting base 36 is in a state of being levitated by the electromagnetic levitation drive unit 48, and
And the guide member 46, respectively. Then, the mounting base 36 moves along the guide shaft 45 and the guide member 46 via the sleeve member 54.

The optical pickup device 33 includes a mounting base 3
When 6 moves, the objective lens 38 moves in the radial direction of the optical disc to read and reproduce the information signal of the optical disc. When the optical pickup device 33 moves to the innermost peripheral portion of the signal recording area of the optical disc, the mounting base 3
When one end of the sleeve member 54 provided in 6 contacts the abutting portion 57A, the movement is stopped.

When the optical pickup device 33 moves to the outermost peripheral portion of the signal recording area of the optical disc, one end of the sleeve member 54 provided on the mounting base 36 abuts on the abutting portion 57B. Is stopped. That is, in the optical disc recording / reproducing apparatus 20, the moving range of the optical pickup device 33 is restricted by the abutting portion 57A and the abutting portion 57B.

The optical disk recording / reproducing apparatus 20 is also provided.
Aligns the optical axis of the objective lens 38 with respect to the mounting base 36 when the optical pickup device 33 is assembled. The alignment adjustment of the optical axis of the bobbin 35 will be described with reference to FIG.

With the bobbin 35 mounted on the mounting base 36, the sleeve member 54 of the mounting base 36 is mounted on the guide shaft 45, and one side surface adjacent to the optical axis of the objective lens 38 is used as a reference surface 37. Alignment adjustment such as skew adjustment for adjusting the inclination of the optical axis of the objective lens 38 with respect to the main surface of the optical disk, which is the signal recording area, is performed. Therefore, in the optical pickup device 33 for which the alignment adjustment has been performed, the reference surface 37 and the optical axis of the objective lens 38 are maintained in an extremely highly accurate positional relationship.

[0017]

The above-mentioned optical pickup device 33 reads the information signal in the signal recording area of the optical disk, and therefore drives the optical disk to rotate while moving toward the inner peripheral portion of the signal recording area of the optical disk. It is necessary to prevent it from coming into contact with a winding coil or the like (not shown) provided on the spindle motor 53. Therefore, when the optical pickup device 33 moves to the inner peripheral portion of the signal recording area of the optical disc, the moving range is regulated so as to stop before the spindle motor 53, and the stop position accuracy is required. ing.

That is, the optical pickup device 33 is provided with an abutting portion 57A located near one end of the guide shaft 45 in order to regulate the range of movement along the guide shaft 45 and the guide member 46. . The optical pickup device 33 includes a mounting base 3 that slides along a guide shaft 45.
6, the sleeve member 54 is provided with an abutting portion 57A.
The movement is stopped by abutting against.

Alternatively, US patent application No. 08/252,
069, the optical pickup device 33.
There is a method of using one side surface portion of the mounting base 36 and stopping the movement by contacting the one side surface portion with an abutting portion 57A provided on the chassis member.

However, in any of the above-mentioned methods, it is difficult to accurately maintain the positional accuracy between the optical axis of the objective lens 38 of the optical pickup device 33 and the abutting portion 57A, and there is a large error in the positional relationship between them. There was a problem that it would occur.

Therefore, according to the present invention, when the optical pickup device moves to the innermost peripheral portion of the disc-shaped recording medium, the optical pickup device can be stopped with high accuracy and the reading start position of the disc-shaped recording medium can be set. An object of the present invention is to provide an assembling method of an optical pickup device and a recording / reproducing device for a disc-shaped recording medium, which can be detected with high accuracy.

[0022]

In order to achieve the above-mentioned object, the method of assembling the optical pickup device according to the present invention is such that the reference surface parallel to the optical axis of the objective lens is formed on one side surface. The alignment and the tilt of the optical axis of the objective lens are adjusted with the reference surface of the base abutted against the reference surface provided on the adjustment jig for adjusting the optical axis of the objective lens. After adjusting the optical axis of the objective lens, the bobbin to which the objective lens is attached is attached to the attachment base to assemble the optical pickup device. Next, the optical pickup device is attached to the guide shaft and the guide member provided on the chassis member so as to be movable over the inner and outer circumferences with respect to the signal recording area of the disk-shaped recording medium. further,
When the optical pickup device is moved to the innermost peripheral portion of the signal recording area of the disc-shaped recording medium, the reference surface of the mounting base is brought into contact with a stopper member provided on the chassis member, so that the optical pickup is mounted. Stop moving the device and assemble.

Further, in the recording / reproducing apparatus for the disk-shaped recording medium according to the present invention, the objective lens, the bobbin in which the objective lens is assembled, and the reference plane for adjusting the arrangement and inclination of the optical axes of the objective lens are provided. A light which is composed of a mounting base provided in parallel with the optical axis and a drive unit for driving the mounting base and is movably assembled to the signal recording area of the disk-shaped recording medium over the inner and outer circumferences. Equipped with a pickup device. The recording / reproducing apparatus for the disk-shaped recording medium is provided with a stopper member that stops the movement of the optical pickup device when the reference surface of the mounting base comes into contact.

The reference surface detects the position of the innermost peripheral portion of the signal recording area of the disc-shaped recording medium by contacting the stopper member, and the optical pickup device uses the stopper member to detect the information of the disc-shaped recording medium. The position reference is used to start moving to the signal reading start position.

Further, the reference plane is provided on the mounting base at a position intersecting with a line connecting the rotation center of the drive motor for rotationally driving the disk-shaped recording medium and the optical axis of the objective lens of the optical pickup. Furthermore, the reference surface is an operation unit that pushes in an operation piece that operates a position detection device that detects the position of the mounting base. The stopper member is provided near the outer peripheral portion of the drive motor.

According to the method of assembling the optical pickup device of the present invention configured as described above, after the optical axis of the objective lens is adjusted with the reference surface of the mounting base as a reference, the optical pickup device causes the disc-shaped recording medium. When the optical pickup device moves to the innermost peripheral part of the signal recording area, the movement of the optical pickup device is stopped by bringing the optical pickup device into contact with the stopper member with the reference surface of the mounting base as a reference.

Further, according to the recording / reproducing apparatus for a disk-shaped recording medium according to the present invention having the above-mentioned structure, when the objective lens provided on the mounting base is mounted on the mounting base, the light of the objective lens is The movement of the optical pickup device is stopped by bringing the reference surface used for adjusting the arrangement and inclination of the shafts into contact with the stopper member provided on the chassis member. Further, in this disc-shaped recording medium recording / reproducing apparatus, the position where the reference surface provided on the mounting base and the stopper member provided on the chassis member are in contact with each other,
The position reference is used to start the movement of the optical pickup device with respect to the signal recording area of the disk-shaped recording medium. Therefore, the recording / reproducing apparatus for this disc-shaped recording medium can detect the position of the optical pickup device with high accuracy.

[0028]

1 is a block diagram of a recording / reproducing apparatus for a disk-shaped recording medium according to an embodiment of the present invention.
It will be described with reference to FIGS. An optical disc recording / reproducing apparatus according to an embodiment using a read optical recording medium (CD-R; hereinafter simply referred to as an optical disc) in which a writing area is provided in a part of an innermost peripheral portion as a disc-shaped recording medium. 1 will be described. This optical disk recording / reproducing apparatus 1
Has almost the same structure as the conventional optical disk recording / reproducing apparatus 20 and includes an optical pickup device 3 for moving the objective lens 8 for reading an information signal with respect to the signal recording area of the optical disk.

The optical disc recording / reproducing apparatus 1 is generally composed of an optical pickup device 3, a guide shaft 15 and a guide member 16 to which the optical pickup device 3 is assembled, a spindle motor 23 for rotationally driving the optical disc, and these guide shafts 15. , Guide member 16 and spindle motor 2
3 and a chassis member 21 respectively arranged therein.

As shown in FIG. 1, the optical pickup device 3 includes an objective lens 8, a bobbin 5 on which the objective lens 8 is provided, and an attachment base 6 on which the bobbin 5 is attached.
And a drive unit 11 assembled to the mounting base 6,
It is composed of a guide shaft 15 and a guide member 16 provided on a chassis member 21 to which the optical pickup device 3 is assembled.

The guide shaft 15 of the chassis member 21 is supported at both ends by a first supporting portion 17A and a second supporting portion 17B, respectively, and the first supporting portion 17A and the second supporting portion 17B. Are provided respectively. Further, in the chassis member 21, both ends of the guide member 16 are respectively supported by the first support portion 17A and the second support portion 17B in parallel with the guide shaft 15, and these first support portions are provided. 17A and 2nd support part 17B
And are provided respectively. The optical pickup device 3 is attached to the guide shaft 15 and the guide member 16.
Are slidably mounted.

The mounting base 6 is formed of a metal material into a substantially rectangular shape, and the bobbin 5 is provided on the main surface thereof. This mounting base 6 has a sleeve mounting portion 10A at one end,
10B are formed integrally with each other, and a sleeve member 24 is provided on these sleeve mounting portions 10A and 10B. The mounting base 6 is slidably mounted on the guide shaft 15 via the sleeve member 24.

A projection 25 is formed on the other end of the mounting base 6 adjacent to the bobbin 5, and a support shaft 26 is provided on one side surface of the projection 25. In the mounting base 6, a rolling bearing 9 is rotatably supported by the support shaft 26, and the rolling bearing 9 is supported by the guide member 16.
It is mounted slidably via.

Further, the mounting base 6 is provided with a drive circuit portion 11 for driving the bobbin 5 on one side surface portion. The drive circuit section 11 is connected to a power supply section (not shown) via a flexible cable 12. An electromagnetic levitation drive unit 19 is provided on the mounting base 6 adjacent to the guide shaft 15, and a magnetic force is generated in the electromagnetic levitation drive unit 19 by the electric power supplied from the drive circuit unit 11. A first magnet member 22A and a second magnet member 22B are provided on the chassis member 21 in parallel with the guide shaft 15.

That is, in the optical pickup device 3, the magnetic force generated by the electromagnetic levitation drive section 19 and the first magnet member 22A arranged at a position corresponding to the electromagnetic levitation drive section 19 are provided.
And the magnetic force generated by the second magnet member 22B and the repulsive force generated by the second magnet member 22B cause it to move while being levitated.

Furthermore, the mounting base 6 has a reference surface 7 parallel to the optical axis of the objective lens 8 provided on the bobbin 5 on one side surface facing the spindle motor 23, and a sliding direction of the mounting base 6. It is provided so as to extend in a direction orthogonal to.

This reference surface 7 is used for alignment adjustment for adjusting the arrangement of the optical axes and skew adjustment for adjusting the inclination of the optical axes in the assembly process of the optical pickup device 3 in which the bobbin 5 is attached to the attachment base 6. It becomes the reference plane.

As shown in FIG. 3, these alignment adjustments and skew adjustments of the optical axis are performed using a dedicated adjustment jig 28 in the manufacturing line of the optical pickup device 3. In this adjusting jig 28, a separate reference surface 29A is prepared for the pickup stopper member 29, and the main guide shaft 30 supporting the pair of sleeve mounting portions 10A, 10B of the mounting base 6 and the rolling bearing 9 are supported. Sub guide shafts 31 are provided respectively. Further, in the optical pickup device 3, the bobbin 5 has a plane within a plane orthogonal to the optical axis of the objective lens 8 with the focal point of the objective lens 8 as a base point.
It has an adjusting structure that is movable in the 0 degree direction.

At the time of adjustment, the pickup stopper member 2
The adjustment television camera 32 provided with a predetermined size and a high precision with respect to the reference surface 29A of the reference numeral 9 allows the reference surface 7 of the mounting base 6 to be the reference surface of the adjustment jig 28 while maintaining their supporting relationship. The position and inclination of the bobbin 5 are finely adjusted in the state of being brought into contact with 29A, and after the adjustment is completed, the bobbin 5 is fixed to the mounting base 6 to complete the assembly process of the optical pickup device 3. Once the alignment adjustment and skew adjustment of these optical axes are completed, it is guaranteed that the optical axis of the objective lens 8 and the reference surface 7 maintain the most accurate positional relationship in the optical pickup device 3.

In the above-mentioned alignment adjustment and skew adjustment of the optical axis, the arrangement and inclination of the optical axis, the inclination angle of the three spots due to the positioning of the diffraction grating, the output of the emitted light, and the emitted light from the optical block are mainly used. Various conditions such as the accuracy of reflecting at right angles by the optical prism, the mounting position of the laser light source, the accuracy of returning light, and the position of the photodetector are adjusted.

The optical pickup device 3 for which the assembly process is completed is assembled into the optical disc recording / reproducing device 1 to have the above-described configuration. When the assembling of the optical pickup device 3 into the optical disk recording / reproducing device 1 is completed, the reference plane 7 has a positional relationship intersecting a line connecting the rotation center of the spindle motor 23 and the optical axis of the objective lens 8 of the bobbin 5. Will be distributed to.

The chassis member 21 is provided with a substantially cylindrical stopper member 14 formed of a metal material and located near the outer peripheral portion of the spindle motor 23. The reference surface 7 provided on the mounting base 6 is the stopper member 1
By contacting the optical pickup 4, the optical pickup device 3
Stop moving.

Since the stopper member 14 is formed of a metal material, the accuracy of the stop position of the optical pickup device 3 due to the contact with the reference surface 7 can be maintained with high accuracy. The stopper member 14 may be provided with a buffer member or may be formed of an elastic material in order to reduce the impact generated when the reference surface 7 of the mounting base 6 abuts.

The bobbin 5 has an objective lens 8 and is elastically displaceably supported by a biaxial actuator.
That is, the bobbin 5 includes a mechanism for adjusting the objective lens 8 in the track direction which is a direction parallel to the signal recording area of the optical disc and a mechanism for adjusting the objective lens 8 in the focus direction which is a direction orthogonal to the signal recording area of the optical disc. And are provided respectively.

In the optical disc recording / reproducing apparatus 1 having the above-described configuration, the optical pickup device 3 is used.
The operation of reading the information signal of the optical disc will be described. The optical disc recording / reproducing apparatus 1 moves the optical pickup device 3 along the guide shaft 15 and the guide member 16 to the inner peripheral portion of the signal recording area of the optical disc.

The optical pickup device 3 moves to the innermost peripheral portion of the signal recording area of the optical disc, so that the reference surface 7 provided on the mounting base 6 contacts the stopper member 14 provided on the chassis member 21. Contact. The movement of the optical pickup device 3 is stopped when the reference surface 7 contacts the stopper member 14.

Then, the optical pickup device 3 starts moving with the position where the reference surface 7 contacts the stopper member 14 as the position reference for moving to the writable area of the information signal or the reading start position. That is, the optical pickup device 3 arrives at the writable area or the reading start position of the information signal of the optical disc by moving a certain distance from this position reference.

As described above, according to the optical disc recording / reproducing apparatus 1 of the embodiment, the optical axis of the objective lens 8 and the reference surface 7 provided on the mounting base 6 are in a highly accurate positional relationship. The optical pickup device 3 is moved with the position where the reference surface 7 comes into contact with the stopper member 14 provided on the chassis member 21 as a position reference to detect the reading start position of the information signal in the signal recording area with high accuracy. You can

Furthermore, the optical disk recording / reproducing apparatus 1 is
When the reference surface 7 provided on the mounting base 6 contacts the stopper member 14 provided on the chassis member 21 to stop the movement of the optical pickup device 3, the optical axis of the stopped optical pickup device 3 is stopped. And spindle motor 23
The accuracy of the distance from the rotation center of is improved.

The above-mentioned optical disk recording / reproducing apparatus 1 is
The chassis member 21 is provided with a stopper member 14 with which the reference surface 7 of the mounting base 6 abuts. However,
As shown in FIG. 4, the chassis member 21 is provided with a position detecting device 27 for detecting the position where the mounting base 6 has moved, and by pushing the operating piece 27A of the position detecting device 27, the position detecting device 27 is pushed. The reference surface 7 may be used as the operation unit that operates the 27.

Although the CD-R is applied as the optical disc to the optical disc recording / reproducing apparatus 1 of the above-described embodiment, the optical disc is not limited to the CD-R, and other disc-shaped recording such as a CD-ROM is also possible. It is also suitable if a medium is applied.

[0052]

As described above, according to the method of assembling the optical pickup device of the present invention, the reference surface provided on the mounting base and the reference surface provided on the adjustment jig for adjusting the optical axis of the objective lens. When the optical pickup device in which the optical axis of the objective lens is adjusted in the state where it is in contact with the surface moves to the innermost peripheral part of the signal recording area of the disk-shaped recording medium, the reference surface of the mounting base contacts the stopper member. By stopping the movement of the optical pickup device by assembling it and assembling it, the optical pickup device in which the optical axis of the objective lens is adjusted with high precision can be assembled with high precision.

As described above, according to the recording / reproducing apparatus for the disk-shaped recording medium of the present invention, the position where the reference surface provided on the mounting base and the stopper member provided on the chassis member come into contact with each other is positioned. As a reference, by starting the movement of the optical pickup device, the accuracy of detecting the reading start position of the disk-shaped recording medium is improved.

[Brief description of drawings]

FIG. 1 is a plan view showing an optical disc recording / reproducing apparatus according to the present invention.

FIG. 2 is a perspective view showing an optical pickup device used in the recording / reproducing apparatus of the optical disc.

FIG. 3 is a perspective view showing a state in which an optical pickup device used in the recording / reproducing apparatus for the optical disc is attached to an adjusting jig.

FIG. 4 is a plan view showing a main part of a recording / reproducing apparatus for the optical disc.

FIG. 5 is a plan view showing a conventional optical disk recording / reproducing apparatus.

FIG. 6 is a perspective view showing an optical pickup device used in a conventional optical disk recording / reproducing apparatus.

[Explanation of symbols]

 1 optical disk recording / reproducing device 3 optical pickup device 5 bobbin 6 mounting base 7 reference surface 8 objective lens 9 rolling bearing 14 stopper member 15 guide shaft 16 guide member 19 electromagnetic levitation drive unit (drive unit) 21 chassis member 23 spindle motor ( Drive motor) 28 Adjustment jig 28A Reference plane

Claims (7)

[Claims] 1. A reference plane of a mounting base having a reference plane parallel to the optical axis of the objective lens formed on one side surface is used as a reference plane provided on an adjustment jig for adjusting the optical axis of the objective lens. After adjusting the arrangement and tilt of the optical axis of the objective lens in the abutting state, the bobbin on which the objective lens is assembled is attached to the mounting base to assemble the optical pickup device, and then the optical pickup device is mounted on the chassis member. The optical pickup device is attached to the guide shaft and the guide member so as to be movable over the inner and outer circumferences of the signal recording area of the disc-shaped recording medium, and the optical pickup device further records the signal of the disc-shaped recording medium. When the optical pickup device is moved to the innermost peripheral portion of the area, the reference surface of the mounting base is brought into contact with a stopper member provided on the chassis member to move the optical pickup device. Assembling method of the optical pickup device characterized by assembling by locked. 2. An optical pickup device mounted on a guide shaft provided on a chassis member and a guide member so as to be movable over the inner and outer circumferences of a signal recording area of a disk-shaped recording medium. By contacting the surface with the stopper member provided on the chassis member, the position corresponding to the innermost peripheral portion of the signal recording area of the disc-shaped recording medium is detected, and then the information signal of the disc-shaped recording medium is read. 2. The method for assembling the optical pickup device according to claim 1, wherein when the movement to the start position is started, the detection position is used as a position reference. 3. An objective lens, a bobbin to which the objective lens is assembled, and a mounting base on which a reference plane for adjusting the arrangement and inclination of the optical axis of the objective lens is provided parallel to the optical axis. An optical pickup device comprising a drive unit for driving the mounting base, and the optical pickup device provided on a chassis member that is movably assembled to the signal recording area of the disk-shaped recording medium over the inner and outer circumferences. When the optical pickup device moves to the innermost peripheral portion of the signal recording area of the disk-shaped recording medium, the reference surface of the mounting base comes into contact with the stopper member, so that the movement operation is performed. A recording / reproducing apparatus for a disk-shaped recording medium, which is stopped. 4. The reference surface detects the position of the innermost peripheral portion of the signal recording area of the disc-shaped recording medium by contacting the stopper member, and the optical pickup device is used to detect the information of the disc-shaped recording medium from the stopper member. The recording / reproducing apparatus for a disk-shaped recording medium according to claim 3, wherein the recording / reproducing apparatus is a position reference for starting movement to a signal reading start position. 5. The reference surface is provided at a position of a mounting base that intersects a line connecting a rotation center of a drive motor that rotationally drives a disk-shaped recording medium and an optical axis of an objective lens of a bobbin. The recording / reproducing apparatus for a disk-shaped recording medium according to claim 3. 6. The recording / reproducing apparatus for a disk-shaped recording medium according to claim 3, wherein the reference surface is an operating portion for pushing in an operating piece for operating a position detecting device for detecting the position of the mounting base. . 7. The recording / reproducing apparatus for a disk-shaped recording medium according to claim 3, wherein the stopper member is provided near an outer peripheral portion of a drive motor for rotationally driving the disk-shaped recording medium.