JP2003132552A - Optical pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical pickup device which eliminates the correction of fluctuation of monitor output when incorporating in a disk drive. SOLUTION: The optical pickup device has a monitor device 3 which monitors light emission quantity of a light emitting element held in an optical base 20. The monitor device is held movable at the optical base. The position of the monitor device is made adjustable from the outside of the optical base. It is desirable to form a through hole 27 in the optical base, and to accommodate the monitor device in the through hole and to make it pressure welded elastically to the hole wall of the through hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup device having a monitor device for monitoring the amount of light emitted from a light emitting element.

[0002]

2. Description of the Related Art Recently, an optical disk drive is often mounted on an electronic device such as a personal computer. CD-R (compact disc recordable), CD-R as one of the recording media usable for the optical disc drive
W (compact disc rewritable) is known. CD
-R is a recording medium on which additional recording can be repeated and is a CD-
RW is a rewritable recording medium, but a CD-ROM
It is also compatible with audio CDs (CD-DA). CD
-R, CD-RW requires a dedicated device and writing application to write to CD-R, CD-R
Reading from W can be performed with a normal CD-ROM drive. CD-R, CD-RW, CD-ROM, audio CD, DVD-ROM, DVD-R, DVD-R
The AM and the like are collectively referred to as an optical disc here.

An optical pickup device is used to record and reproduce data on such an optical disc. The optical pickup device includes a device body that is movable in the radial direction of the optical disc, a light emitting element, a light receiving element, and an optical system that are held by the device body. The light emitting element is for generating a laser beam. The light receiving element is for detecting the reflected light from the optical disk. The optical system is for guiding the laser beam or the reflected light from the optical disk.

Particularly when recording data on an optical disk, it is necessary to strictly control the light emission amount of the light emitting element. Therefore, an optical pickup device capable of writing data is equipped with a monitor device for monitoring the light emission amount of a light emitting element. That is, the monitor output of the monitor device is
The amount of light emitted is controlled by feeding back to the driving device for the light emitting element.

[0005]

However, since the light receiving sensitivity of the monitor device used in the optical pickup device varies greatly, there is a problem that the monitor output varies even when the monitor device is mounted at a predetermined position. Therefore,
When incorporating the optical pickup device into the disc drive, it is necessary to correct variations in the monitor output for each optical pickup on the disc drive side. The variation correction on the disk drive side when incorporating the optical pickup device into the disk drive is a complicated and troublesome work as is well known.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an optical pickup device in which the mounting position of the monitor device can be easily adjusted, thereby eliminating the need for correcting variations in monitor output when the monitor device is incorporated into a disk drive. .

[0007]

According to the present invention, an optical base (20), a light emitting element (1) held by the optical base, and a monitor device (3) for monitoring the light emission amount of the light emitting element. In the optical pickup device including the optical pickup device, the monitor device is movably held on the optical base, and the position of the monitor device can be adjusted from the outside of the optical base.

The optical base may have a through hole (27) for accommodating the monitor device, and the monitor device may be elastically pressed against a hole wall of the through hole.

The monitor device includes a photodiode (31) arranged in the through hole, and a signal processing device (32) connected to the photodiode and inserted between the photodiode and a hole wall of the through hole. And the photodiode may be pressed against the hole wall of the through hole by the pressing force existing in the signal processing device.

In the signal processing device, the signal processing device includes two flexible substrates (33, 34) inserted between the photodiode and a hole wall of the through hole in an overlapping manner, and the flexible substrate. And a chip component (35) arranged between
A restoring force generated as a result of bending at least one of the two flexible substrates by the chip component may be used as the pressing force.

Means may further be provided for fixing the monitor device to the optical base in a state of being aligned with the light emitting element.

The reference numerals in the parentheses are given for easy understanding and are merely examples, and the present invention is not limited to these.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An outline of an optical pickup device according to an embodiment of the present invention will be described with reference to FIG.

The illustrated optical pickup device can be used in an optical disk drive mounted in an electronic device such as a personal computer, and uses a laser diode 1 which is a semiconductor laser for generating a laser beam as a light emitting element. The laser beam emitted from the laser diode 1 is split by the beam splitter 2, and a part of the laser beam is incident on the monitor device 3. The other part of the laser beam irradiates the optical disk 7 through the collimator lens 4, the raising mirror 5, and the objective lens 6. The monitor device 3 detects the intensity of the laser beam, generates a monitor output indicating the intensity, and supplies the monitor output to the LD driver 8. LD driver 8
Is connected to the driving power supply 11 via the connector 9 and drives the laser diode 1 with reference to the monitor output. In this way, data can be recorded on the optical disk 7 by using the laser beam emitted from the laser diode 1.

The reflected light from the optical disk 7 is incident on the photodiode 12 as a light receiving element via the objective lens 6, the raising mirror 5, the collimating lens 4, the beam splitter 2, and the like. In this way, the data can be reproduced from the optical disk 7 by using the laser beam emitted from the laser diode 1.

Before assembling in the optical disk drive, the variation of the monitor output of the optical pickup device is corrected. In that case, while connecting the adjustment power supply 13 and the voltmeter 14 to the LD driver 8 via the connector 9,
A power meter (not shown) is arranged instead of the optical disk 7. In this state, the value of the monitor output at a light amount of 1 mW is measured by the voltmeter 14, the position of the monitor device 3 is adjusted with reference to the value, and the value of the monitor output is adjusted within the standard.

The optical pickup device will be specifically described with reference to FIGS. 2 to 4 in addition to FIG.

Various optical elements such as the beam splitter 2, the collimator lens 4, the rising mirror 5 and the objective lens 6 arranged in the path of the laser beam are collectively referred to as an optical system here. The optical system, the laser diode 1, the monitor device 3, the LD driver 8, the connector 9, and the photodiode 11 are an optical base 20 that is a device housing.
Held in. The optical base 20 is movably mounted on the optical disk device using the guide hole 21.

As shown in FIG. 2, an upper cover 23 is provided on the upper surface of the optical base 20 via a flexible flat cable 22. Two upper adjusting holes 24 are formed in the upper cover 23. On the other hand, the optical base 20
As shown in FIG. 3, a lower cover 25 is provided on the lower surface of the. A lower adjustment hole 26 is formed in the lower cover 25 so as to face the area including the two upper adjustment holes 24 in the vertical direction.

Further, as shown in FIG. 4, the optical base 20 is provided with through holes 27 having a rectangular horizontal cross section and formed at positions facing the upper adjusting hole 24 and the lower adjusting hole 26. There is. The monitor device 3 is inserted into the through hole 27 and is fixed to the optical base 20 with, for example, a resin adhesive. In addition, 28 is a variable resistance.

The monitor device 3 includes a photodiode 31 arranged in the through hole 27, and a signal processing device 32 connected to the photodiode 31 and inserted between the photodiode 31 and the hole wall of the through hole 27. . In this state, the signal processing device 32 has an internal pressing force, and the pressing force elastically presses the photodiode 31 against the hole wall of the through hole 27.

As a result, the monitor device 3 is held by the optical base 20 by a frictional force so as to be movable, that is, movable in the through hole 27 before being fixed by the adhesive, and is in a temporarily fixed state. . Therefore, an adjustment tool such as a pin is attached to the upper adjustment hole 24 and the lower adjustment hole 26 from the outside of the optical base 20.
It is possible to adjust the position of the monitor device 3 by inserting it through.

Referring to FIGS. 5 and 6, the optical base 20
The attachment of the monitor device 3 to the will be specifically described.

The signal processing device 31 includes a photodiode 32.
The first and second flexible substrates 33 and 34 that are inserted between the first flexible substrate 33 and the hole wall of the through hole 27, and the second flexible substrate 34 is mounted on one surface of the first flexible substrate 33. And a plurality of chip components 35 covered with. First flexible substrate 33
Is integrated with the flexible flat cable 22 via a connecting portion 36. The photodiode 31 is mounted on the opposite surface of the first flexible substrate 33, that is, the surface opposite to the chip component 35. The second flexible substrate 34 is integrated with the first flexible substrate 33 via the connecting portion 37, and is superposed on the second flexible substrate 34 with the connecting portion 37 bent.

When the first and second flexible substrates 33 and 34 are pressed into the through hole 27 in a stacked state, as shown in FIG.
The second flexible substrate 34 bends due to the presence of the chip component 35, and as a result, the second flexible substrate 33 generates a restoring force. This restoring force acts as the above-mentioned pressing force, and thus the monitor device 3 is held by the frictional force so as to be movable in the through hole 27.

In order to effectively generate the restoring force of the second flexible substrate 33, the optical base 20 has the chip parts 3
A recess or notch 38 is formed in the portion corresponding to 5.

Further, the cross-sectional shape of the through hole 27 is not limited to the rectangular shape, but may be a semicircular shape or a semielliptic diameter, and the recesses or the notches 38 can be omitted.

[0028]

As described above, according to the present invention,
Since the mounting position of the monitor device can be easily adjusted, it is possible to provide an optical pickup device which does not require the correction of variations in the monitor output when the monitor device is incorporated into a disk drive.

[Brief description of drawings]

FIG. 1 is an explanatory diagram for explaining an outline of an optical pickup device according to an embodiment of the present invention.

2 is a perspective view from above specifically showing the optical pickup device of FIG. 1. FIG.

FIG. 3 is a perspective view from below specifically showing the optical pickup device of FIG. 1;

FIG. 4 is a perspective view from above of only a main part showing a state where an upper cover of the optical pickup device of FIG. 2 is removed.

5 is a perspective view showing in detail the mounting structure of the monitor device with respect to the optical base in FIG.

FIG. 6 is a perspective view showing a state in which the monitor device in FIG. 5 is detached from the optical base.

[Explanation of symbols]

1 laser diode 2 beam splitter 3 Monitor device 4 Collimating lens 5 Launch mirror 6 Objective lens 7 Optical disc 8 LD driver 9 connectors 11 Drive power supply 12 photodiodes 13 Power supply for adjustment 14 Voltmeter 20 Optical base 21 Guide hole 22 Flexible flat cable 23 Top cover 24 Upper adjustment hole 25 Lower cover 26 Lower adjustment hole 27 through holes 28 Variable resistance 31 Photodiode 32 signal processor 33 First Flexible Substrate 34 Second flexible substrate 35 Chip parts 36 Connection 37 Connection 38 recesses or notches

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5D117 AA02 CC07 HH10 KK04 KK22                 5D119 AA38 BA01 BB01 BB02 BB04                       FA23 HA12 HA44 KA42                 5D789 AA38 BA01 BB01 BB02 BB04                       FA23 HA12 HA44 KA42

Claims (5)

[Claims] 1. An optical pickup device having an optical base, a light emitting element held by the optical base, and a monitor device for monitoring the amount of light emitted by the light emitting element, wherein the monitor device is movably held by the optical base. The optical pickup device is characterized in that the position of the monitor device can be adjusted from the outside of the optical base. 2. The optical pickup device according to claim 1, wherein the optical base has a through hole that accommodates the monitor device, and the monitor device is elastically pressed against a hole wall of the through hole. 3. The monitor device includes a photodiode arranged in the through hole, and a signal processing device connected to the photodiode and inserted between the photodiode and a hole wall of the through hole. The optical pickup device according to claim 2, wherein the photodiode is pressed against the hole wall of the through hole by a pressing force existing in the signal processing device. 4. The signal processing device comprises: two flexible substrates which are inserted between the photodiode and the hole wall of the through hole in an overlapping manner; and a chip component arranged between the flexible substrates. 4. The optical pickup device according to claim 3, wherein a restoring force generated as a result of bending at least one of the two flexible substrates by the chip component is used as the pressing force. 5. The optical pickup device according to claim 1, further comprising means for fixing the monitor device to the optical base in a state of being aligned with the light emitting element.