JP2002025100A - Complex optical member and complex optical unit provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a complex optical member which is compact and has a beam shaping function and a complex optical unit provided with the same. SOLUTION: The complex optical member 105 consisting of the molding of a transparent resin and having a incident plane 105a for a laser beam emitted from a double wavelength laser diode 102, a light-reflecting surface 105b to reflect the laser beam emitted from the double wavelength laser diode 102 and on which a return light beam from an optical disk 61 (62) is made incident, and a reflecting surface 105d to guide the return light beam from the optical disk 61 (62) to a light receiving member 104, is mounted on the complex optical unit 101. The incident plane 105a is formed so as to have a concave surface in a cylindrical shape, a light-reflecting surface 105b is formed so as to have a convex face in a cylindrical shape having a different curvature from the incident plane 105a, or the incident plane 105a is inclined with respect to the incident direction of the laser beam emitted from the double wavelength laser diode 102. Thereby, the beam shaping function is given to the complex optical member 105.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite optical member integrally having a plurality of optical functions and a composite optical unit having the same, and more particularly to a composite optical member having a beam shaping means. About.

[0002]

2. Description of the Related Art First, an optical unit for a CD (compact disk) provided with a conventional composite optical member will be described with reference to FIGS. FIG. 15 is a partial sectional view of a conventional optical unit 50, and FIG. 16 is a partially exploded perspective view of the conventional optical unit 50.

[0003] As shown in FIG.
Reference numeral 0 denotes a light source 46 that emits laser light (wavelength 780 nm band) for CD, a light receiving member 47 that receives laser light reflected by a CD (not shown), and a substrate unit having the light source 46 and the light receiving member 47. 48a and a side wall portion 48b attached and fixed to the substrate portion 48a so as to include the light source 46 and the light receiving member 47.
And an emission part 48d which is an opening window of the side wall part 48b, and a light-transmissive composite optical member 49 such as glass joined so as to cover the emission part 48d.

A light source 46 is fixed on a substrate 48 a so as to face the composite optical member 49, and a light receiving member 47.
Are formed on the surface of the substrate portion 48a close to the light source 46. The diffraction grating 49 a formed on the upper end surface of the composite optical member 49 diffracts the return light emitted from the light source 46 and reflected by the CD to guide it to a predetermined position on the light receiving member 47. In addition, a beam forming portion 49b, which is a diffraction grating, is provided on the lower end surface of the composite optical member 49 in order to perform tracking control by the three-beam method.

As shown in FIG. 16, the composite optical member 49 is moved relative to a housing composed of a substrate portion 48a and a side wall portion 48b in the x and y directions orthogonal to the optical axis N and in the rotation direction around the optical axis. The optical axis is adjusted in a certain θ direction. The optical axis alignment between the composite optical member 49 and the housing is
This is performed by holding the composite optical member 49 with a jig (not shown) having a fine adjustment mechanism and operating the fine adjustment mechanisms in the x, y, and θ directions. After the completion of the optical axis alignment, the composite optical member 49 is bonded to the emission part 48d of the housing.

[0006]

The optical unit 50 according to the prior art described above uses a jig provided with a fine adjustment mechanism,
The optical axis alignment of the composite optical member 49 with respect to the housing is represented by x
The adjustment must be performed in three directions, i.e., the y direction and the .theta. Direction, and the adjustment range is very small.
There is a problem that it is difficult to manufacture 0 efficiently.

Further, the composite optical member 4 with respect to the housing
Since the composite optical member 49 needs to be bonded to the housing after the completion of the optical axis alignment of No. 9, there is a problem that the working process is also complicated from this point.

Further, since the optical unit 50 according to the conventional example does not have a beam shaping means for shaping the spot shape of the laser light emitted from the light source 46 into a circle, the laser power applied to the CD is not changed. Wasteful,
There is also a problem that it cannot be applied to an optical disk device that records and reproduces information by mounting a write-once or rewritable optical disk that requires a larger laser power. In this case, if a beam shaping means such as a triangular prism or a cylindrical lens is incorporated in the optical unit 50, such inconvenience can be solved. Incorporation of the shaping means not only increases the size of the optical unit 50, but also necessitates an operation of positioning the beam shaping means with respect to the complex optical member 49, which requires a great deal of labor, so that the manufacturing efficiency of the optical unit 50 is further reduced. become.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned deficiencies of the prior art, and has as its object to provide a composite optical member having a compact beam shaping function and a beam shaping means for the composite optical member. An object of the present invention is to provide a composite optical unit that does not require the adjustment operation of the above.

[0010]

In order to solve the above-mentioned problems, the present invention relates to a composite optical member, in which an incident surface of a laser beam emitted from a light emitting member and a laser beam incident on the incident surface are formed on an optical disk. An emission surface for emitting light toward the optical disk, a return light incident surface on which return light from the optical disk is incident, a diffraction unit formed on the return light incident surface, and diffracting the return light in a predetermined direction; The reflecting surface for guiding the return light diffracted by the means to the light receiving member and the beam shaping means for shaping the spot shape of the laser light emitted from the light emitting member into a circular shape are integrally provided.

As the beam shaping means, the incident surface of the composite optical member is formed as a cylindrical concave surface, and the output surface of the composite optical member is formed as a cylindrical convex surface having a different curvature from the incident surface. Or a means for inclining the incident surface of the composite optical member with respect to the incident direction of the laser light emitted from the light emitting member. Also,
The incident surface of the composite optical member may include an optical diffraction unit that divides the laser light emitted from the light emitting member into a plurality of light beams.

On the other hand, with respect to the composite optical unit, a composite optical member, a light emitting member, and a light receiving member are attached to a housing, and the composite optical member has an incident surface of a laser beam emitted from the light emitting member. An emission surface from which the laser light incident on the incident surface is emitted toward the optical disc, a return light incidence surface on which return light from the optical disc is incident, and the return light formed on the return light incidence surface; Means for diffracting the light in a predetermined direction, a reflecting surface for guiding the return light diffracted by the diffracting means to the light receiving member, and beam shaping for shaping the spot shape of the laser light emitted from the light emitting member into a circle. It is configured to use a unit integrally provided with the means.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a composite optical member according to the present invention and a composite optical unit having the same will be described below with reference to FIGS.

FIG. 1 is a configuration diagram of an optical pickup device 100 having a composite optical unit according to the first embodiment, and FIG.
3 is a perspective view of the two-wavelength laser diode 102 partially sectioned, FIG. 3 is a front view of the composite optical member 105 according to the first embodiment, FIG. 4 is a left side view of FIG. 3, and FIG. 5 is a right side view of FIG. FIG. 6, FIG. 6 is a view from the direction of arrow 6 in FIG. 3, FIG. 7 is a plan view of the housing 106, FIG. 8 is a sectional view taken along line 8-8 in FIG.
8 is a left side view of FIG. 8, FIG. 10 is a right side view of FIG. 8, FIG. 11 is a view from the direction of arrow 11 of FIG. 8, FIG. 12 is a partial cross-sectional view along line 12-12 in FIG. FIG. 13 is an explanatory diagram for explaining the function of the composite optical member 105.

As shown in FIG. 1, an optical pickup device 1
00 is a pickup body, that is, a carriage 500.
And a composite optical unit 101 disposed in the carriage 500, a flat reflecting mirror 300, a collimating lens 400, and an objective lens 200. A member 105 is provided.

The optical pickup device 100 includes an optical disk, for example, a CD 61 or a DVD (digital versatile disk or digital video disk) 62
Focusing (F) which is arranged in a direction orthogonal to the disk surface of the CD 61 (DVD 62).
The objective lens 200 is movably supported in the tracking direction (T), which is the radial direction of the CD 61 (DVD 62). The objective lens 200 is a CD61 and a DV.
It is configured to be compatible with both D62.

The composite optical unit 101 irradiates a laser beam onto the optical disk and reflects light (return light) from the optical disk.
A light receiving / emitting integrated optical element used for reproducing information recorded on an optical disk by receiving light, or for recording information on an optical disk.
As shown in FIG. 2, a two-wavelength laser diode 102 serving as a light emitting member, a light receiving member 104 having a light receiving element 104a built therein, a composite optical member 105,
07 and a housing 10 to which these members are attached and fixed.
6 is comprised.

As shown in FIG. 2, the two-wavelength laser diode 102 has a disc-shaped substrate portion 102a and a substrate portion 102a.
a, a rectangular parallelepiped base 102b protruding from one flat portion 102a ', a laser chip 103 positioned and fixed on the side wall surface of the base 102b, and a flat portion 102a' including the base 102b. A cylindrical body 1 that is attached and fixed
A transparent plate-shaped glass plate 102f fixed to cover the opening 102d 'from the inside of the cap 102e, and a cap portion 102e composed of a top plate 102d having an opening 102d' and an opening 102d '; Substrate section 102a
The laser chip 103 is disposed in a closed space formed by the laser chip 103 and a cap 102e and a glass plate 102f. The laser chip 103 includes a light source 103a that emits a short-wavelength (wavelength 650 nm band) laser beam 103a 'for DVD and a long-wavelength (wavelength 780n) for CD.
The light source 103b that emits the laser light 103b 'of the m band) is formed at a small interval D. In this embodiment, the interval D is set to 120 μm. In addition, the 650 nm band for DVD is, specifically, 6 band.
35 nm or 650 nm has been adopted as the DVD standard.

The laser beams 103a 'and 103b' emitted from the light sources 103a and 103b are emitted through the openings 102d 'so as to be parallel to each other in a direction perpendicular to one plane 102a' of the substrate 102a. Is done. The emission positions of the laser beams 103a 'and 103b' are set at the tip surface 103 'of the laser chip 103 (flat portion 1).
02a 'is arranged on the same plane. Further, the substrate unit 102
A plurality of external connection terminals 102g (see FIG. 1) are protruded from the other flat portion 102a 'on the side opposite to the one flat portion 102a', and the laser chip 103 is connected to the laser chip 103 via the external connection terminals 102g. It supplies drive current.

In the process of manufacturing the two-wavelength laser diode 102, the laser chip 103 having the two light sources 103a and 103b is processed on a predetermined substrate surface by a process similar to a semiconductor process.
The distance D between a and 103b can be easily and uniformly formed to a predetermined value with high accuracy. In addition, since mass production of discrete components is possible, the cost of the two-wavelength laser diode 102 can be reduced.

As shown in FIG. 1, the light receiving member 104 includes a package 104 having a light receiving element 104a built therein and a light receiving window 104b 'provided on the light receiving surface side of the light receiving element 104a.
b, and external connection terminals 104c protruding from both sides from the package 104b.
The supply of the power supply voltage to the power supply and the output of the signal photoelectrically converted by the light receiving element 104a to the outside are performed via the external connection terminal 104c.

The composite optical member 105 shown in FIGS.
Is a substantially conical base portion 105 formed of a molded body of a resin material having high transparency and having both end faces in the direction of the optical axis N formed in parallel.
c, an incident surface 105a of the laser light emitted from the two-wavelength laser diode 102, an emission surface 105b for emitting the laser light emitted from the two-wavelength laser diode 102 toward the optical disk, and a return light from the optical disk. And the reflection surface 105d for guiding the light to the light receiving element 104a are integrally formed. The composite optical member 105 according to the present embodiment has a configuration in which the incident surface of the return light from the optical disk is also used as the emission surface 105b, and the return light from the optical disk is incident on the emission surface 105b. I have.

The entrance surface 105a is formed as a cylindrical concave surface, and the exit surface 105b is located on the entrance surface 10a.
The curved surface has a different curvature from that of 5a, and is formed as a cylindrical convex surface in which the central axis direction of the curved surface is arranged parallel to the incident surface 105a. These entrance surface 105a and exit surface 1
The curvature 05b is emitted from the emission surface 105b when the laser beam emitted from the two-wavelength laser diode 102 enters the center of the incidence surface 105a in the direction of the central axis of the incidence surface 105a. The spot shape of the laser beam is adjusted to be circular. For example, when the distance between both end surfaces of the composite optical member 105 is 4 mm, the entrance surface 105a is formed into a concave surface having a focal length of 2.6, and the exit surface 105b is formed.
Is a convex surface having a focal length of 6.6.
The spot shape of the laser light emitted from the wavelength laser diode 102 can be shaped into a circle. That is, 2
Since the spot shape of the laser light emitted from the wavelength laser diode 102 is elliptical, the light is incident toward the central axis direction of the incident surface 105a so that the incident surface 105a is As in the case where the cylindrical lens is arranged on the laser light incident side or the emission side of the composite optical member formed in parallel, the emission surface 105 is formed.
The spot shape of the laser beam emitted from b can be shaped into a circle.

As shown in FIGS. 3 and 4, the incident surface 105a diffracts the laser light emitted from the two-wavelength laser diode 102 to control the tracking applied to the CD and to reproduce the data. The three-beam generation diffraction grating 105h for generating the three beams is formed.

As shown in FIGS. 3 and 5, the return light from the optical disk is reflected by the reflection surface 10b at the center of the emission surface 105b.
A rectangular first diffraction grating 105f for leading to 5d is formed.

The reflection surface 105d is an inclined surface that is inclined with respect to both end surfaces of the composite optical member 105, and the surface of the reflection surface 105d has a return light path as shown in FIGS. Reflection type second diffraction grating 1 for correcting
05 g are formed. In the transmission path of the return light reflected by the reflection surface 105d, a flat surface 105n is formed over the peripheral surface of the base portion 105c. As shown in FIG. 6, a cylinder surface 1 for performing focus control by the astigmatism method is provided from the edge of the flat surface 105n.
05i is formed in a groove shape having a predetermined angle α with the optical axis N, and the inner wall of the cylinder surface 105i is a return light emission surface 105p.

The composite optical member 1 according to this embodiment is
05, the first and second diffraction gratings 105
f, 105g and a three-beam diffraction grating 105h are integrally formed with the incident surface 105a, the outgoing surface 105b, the base portion 105c, the reflecting surface 105d, and the cylinder surface 105i using a molding die. Each of these diffraction gratings 105
The functions of f, 105g, and 105h will be described later in more detail.

The base portion 105c is formed in a substantially conical shape whose diameter gradually decreases from the incident surface 105a side to the emission surface 105b side, and a columnar portion 105j is formed at the front end of the base portion 105c. The cylindrical surface 105j 'serves as a first restricting portion for the housing 106.

On the rear end side of the base portion 105c, that is, on the outer peripheral surface on the side where the incident surface 105a and the reflective surface 105d are formed,
As shown in FIG. 3 and FIG. 4, 4 having a semi-cylindrical outer surface
The two protrusions 105k 'are formed so as to be arranged substantially evenly in the circumferential direction, and the columnar surfaces of these protrusions 105k' serve as second restricting portions for the housing 106. Further, the rear end surface of the base portion 105c (the incident surface 105a
And a part of the reflection surface 105d. )
As shown in FIGS. 3, 4, and 12, each of the protrusions 105
A space 105 for buffering the press-fit of the composite optical member 105 to the housing 106 is provided in a portion facing k ′.
s is counterbore formed at a predetermined depth.

Further, as shown in FIGS. 3 to 6, a columnar position regulating protrusion 105 is provided at the center of the base 105c.
m is formed to protrude downward.

The composite optical member 105 according to this embodiment is
Although the outgoing surface 105b and the return light incident surface are the same,
The output surface and the return light incident surface may be separately provided, and the first diffraction grating may be formed on the return light incident surface.

The housing 106 shown in FIGS.
Consists of aluminum die-cast blocks, mainly
It comprises a cylindrical body 106g and mounting portions 106h and 106i projecting outward from both ends of the cylindrical body 106g. These mounting portions 106h and 106i have rectangular mounting surfaces 106h 'and 106i', respectively.

As shown in FIG. 8, an accommodation chamber 106a for accommodating the two-wavelength laser diode 102 shown in FIG. 2 is formed on the inner surface at the left end of the cylindrical body 106g. Has a counterbore formed with a mounting hole 106b for positioning and mounting the two-wavelength laser diode 102. On the other hand, an accommodation room 106c for accommodating the composite optical member 105 shown in FIG. 3 is formed on the inner surface of the right end of the cylindrical body 106g. 1st regulation part (cylindrical surface 1
05j '), and a second restricting portion (projection 105) formed on the composite optical member 105.
k ′) are formed, respectively. Each of these storage rooms 106a and 106c
It is formed concentrically with respect to the central axis N '.

An accommodation chamber 106c for accommodating the composite optical member 105 is provided with the two-wavelength laser diode 102.
Is formed in a conical shape in which the diameter on the side of the storage portion 106k for storing is gradually increased and gradually decreases toward the mounting surface 106i '. Also, the first regulation receiving unit 1
The diameter of 06j is set to a size that allows the columnar portion 105j (diameter D1) of the composite optical member 105 (see FIG. 3) to be fitted with high precision. Each protrusion 105k 'provided at the rear end 105k
Is set to a predetermined dimension that is shorter than the diameter D2 (see FIG. 4) of the circumscribed circle circumscribing the tip of the.

A positioning portion for positioning the composite optical member 105 in the direction of the central axis N ', that is, an abutting surface 106c' is formed at the front end of the accommodation chamber 106c. The abutting surface 106c 'has a circular opening 10
6f is provided so that the first diffraction grating 105f provided in the composite optical member 105 is exposed forward.

Further, FIG.
As shown in FIG. 11, the accommodation chambers 106a, 106
c and a rear end of the U-shaped hole-shaped position regulating groove 106d penetrating through the accommodation chamber 10d.
A fan-shaped guide groove 106d 'penetrating the rear end of 6a is formed. The groove width of the position restricting groove 106d is set to a predetermined size such that the outer diameter of the position restricting protrusion 105m protruding from the composite optical member 105 can be fitted with high precision. An arrangement surface 1 for arranging the light receiving member 104 is provided on a portion of the storage portion 106g facing the position regulating groove 106d.
06e is formed. This arrangement surface 106e corresponds to FIG.
As shown in FIG. 5, when the printed circuit board 107 to which the light receiving member 104 is electrically connected is mounted on the mounting surfaces 106h 'and 106i' of the mounting portions 106h and 106i, the light receiving member 104 does not interfere with the housing 106.
A required step is formed between each of the mounting surfaces 106h 'and 106i'.

The block used for the housing 106 is not only an aluminum die cast but also a zinc die cast.
It may be made of a magnesium alloy or another metal.

Hereinafter, referring to FIG.
Laser diode 102, light receiving member 104,
A method of assembling the composite optical member 105 will be described.

The composite optical member 105 includes the position regulating projection 10.
5m is formed in a guide groove 106d 'formed in the housing 106.
Is inserted through the mounting hole 106b of the housing 106 in a state where the base portion 105c of the incident surface 105a except the diffraction grating 105h is uniformly pressed by a required jig (not shown). Accommodation room 106c
Fit inside. Then, when the outer edge of the emission surface 105b comes into contact with the abutting surface 106c 'formed in the housing chamber 106c of the housing 106, positioning in the direction of the central axis N' with respect to the housing 106 is performed.

At this time, the columnar portion 105j provided on the base portion 105c is connected to the first regulation receiving portion 10 of the accommodation chamber 106c.
6j, the columnar portion 10 of the base portion 105c.
The cylindrical surface 105j '(control surface, see FIG. 3) of 5j abuts on the first control receiving portion 106j, and the position of the front end of the base portion 105c in the direction orthogonal to the optical axis N is controlled with high precision. At the same time, the rear end portion 10c of the base portion 105c is formed.
5k is press-fitted into the second regulation receiving portion 106k provided in the accommodation room 106c. At this time, as shown in FIG.
Each of the projections 105k 'formed on the outer peripheral surface of each of the projections 105k' is uniformly crushed.
Of the base member 105c in the direction perpendicular to the central axis N ', the position of the rear end portion 105k of the base portion 105c is regulated with high precision. From the accommodation room 106c is prevented. Further, the composite optical member 105 is
By fitting into the mounting hole 106b provided in the
Position regulating protrusion 105m formed on composite optical member 105
Is guided by the guide groove 106d 'formed in the housing 106 and fitted into the position regulating groove 106d, so that the position in the rotation direction about the central axis N' is regulated with high accuracy.

As described above, in the composite optical unit 101 of the present embodiment, the position of the composite optical member 105 in the direction of the central axis N 'with respect to the housing 106 is restricted and the center is adjusted only by fitting the composite optical member 105 into the housing 106. Since the position regulation in the direction orthogonal to the axis N 'and the position regulation in the rotation direction about the central axis N' can be performed, the assembly of the composite optical unit 101 can be performed easily and with high precision.
Further, in the composite optical unit 101 of the present embodiment, since the space 105s is formed so as to face the space corresponding to the formation of the protrusion 105k 'in the composite optical member 105, the distal end surface of each protrusion 105k' (restriction). Face) to the second regulation receiving unit 106
When abutting on the k, the formed portion of each protrusion 105k 'is elastically deformed toward the space 105s side, so that the press-in force is relieved, and the press-in force more than necessary can be prevented from acting on the composite optical member 105. Thus, it is possible to prevent the distortion of the optical function part, particularly the distortion of the second diffraction grating 105g and the three-beam diffraction grating 105h.

The two-wavelength laser diode 102 has its cap portion 102e (see FIG. 2) inserted into a housing chamber 106a of a housing 106, and the base portion 102a is fitted into a mounting hole 106b formed in the housing 106. It is fixed to the housing 106. Thereby, as shown in FIG. 13, the optical axis N of the laser light emitted from the two-wavelength laser diode 102 can be automatically matched with the central axis N 'of the housing 6, and the composite optical member 1
Since the laser light emitted from the two-wavelength laser diode 102 can be made incident on the center of the incident surface 105a of the laser beam 05, the spot shape of the laser light can be shaped into a circle.

As shown in FIGS. 1 and 13, the light receiving member 104 is connected to a housing 106 via a printed circuit board 107.
Attached to. The light receiving member 104 is attached to the printed circuit board 107 by connecting the light receiving window 104b 'of the package 104b to the through hole 1 formed in the printed circuit board 107.
07a and soldering the external connection terminals 104c to lands (not shown) formed on the surface of the printed circuit board 107. In addition, if necessary, the package 104b is connected to the printed circuit board 107 or the housing 1.
06 may be fixed by an adhesive or the like to reinforce. Then, the printed circuit board 107 to which the light receiving member 104 is fixed
Is in a state where the light receiving window 104b 'is disposed so as to face the position regulating groove 106d formed in the housing 106.
The mounting surface 106 of each of the mounting portions 106h and 106i
h ′ and 106i ′, and are fixed by fastening with screws 108 to the housing 106. The printed circuit board 107 on which the light receiving member 104 is mounted is provided with first and second diffraction gratings for returning laser light 103a 'and 103b' emitted from the light sources 103a and 103b by a predetermined reference optical system. 105f and 10
After being adjusted to be optimally guided to the predetermined position P of the light receiving element 104a when diffracted by 5 g, the mounting surface 106
h 'and 106i'.

Next, D by the optical pickup device 100
The reproduction operation of VD62 and CD61 will be described.

In the above configuration, when reproducing the DVD 62, as shown in FIG. 1, the laser beam 103 emitted from the light source 103a of the two-wavelength laser diode 102 is used.
a 'is transmitted through the three-beam diffraction grating 105h formed on the incident surface 105a of the composite optical member 105, converted into three beams, transmitted through the first diffraction grating 105f, and emitted from the emission surface 105b. .

The laser beam 103a 'is deflected at an angle of 90 degrees by a reflection mirror 300 arranged at an angle of 45 degrees with respect to the traveling direction of the laser beam 103a', and is disposed above the reflection mirror 300. The light enters the collimator lens 400. Then, the laser beam 103 a ′, which has been made substantially collimated by the collimating lens 400, enters the objective lens 200 and is focused on the information recording surface of the DVD 62 by the condensing action of the objective lens 200.

The laser beam (return light) 103a 'reflected by the DVD 62 again passes through the objective lens 200 and the collimator lens 400, is reflected by the reflection mirror 300, and then enters the return light entrance surface, ie, the exit surface 105b shown in FIG. Return light 103a'- which is the first-order diffracted light that is incident on the first diffraction grating 105f formed at
It becomes 2. The return light 103a'-2 is further reflected on the return light reflecting surface 105d formed on the composite optical member 105, enters the cylinder surface 105i, and is emitted from the return light exit surface 105p. Then, the emitted return light 103a'-2 passes through the position regulating groove 106d (see FIGS. 8 and 11),
Light receiving position P on light receiving element 104a of light receiving member 104
Incident on.

At this time, the return light 103a'-2 received by the light receiving element 104a is converted to
The reproduction signal is generated by converting the current output corresponding to the signal on the information recording surface of D62 into a voltage signal, output from the external connection terminal 104b of the light receiving member 104, and transmitted to the outside through the printed circuit board 107. A part of the return light 103a'-2 received by the light receiving element 104a is used for focus and tracking control.

On the other hand, when reproducing the CD 61, the laser beam 103b 'emitted from the light source 103b of the two-wavelength laser diode 102 is diffracted by three beams formed on the incident surface 105a of the composite optical member 105 as shown in FIG. After being transmitted through the grating 105h and converted into three beams, the light is transmitted through the first diffraction grating 105f and emitted from the emission surface 105b. Then, the laser beam 103b 'is guided to the objective lens 200 as in the case of the DVD 62, and
By the light condensing action of 00, an image is formed on the information recording surface of the CD 61.

The return light 10 reflected by the CD 61
3b 'indicates the objective lens 200 and the collimating lens 4 again.
After passing through the first reflection grating 300 and being reflected by the reflection mirror 300, it is incident on the first diffraction grating 105f and becomes return light 103b'-2, which is the first-order diffraction light diffracted at a predetermined diffraction angle. The return light 103b'-2 is further reflected by the return light reflecting surface 105d "formed on the composite optical member 105 and is incident on the cylinder surface 105i. On the cylinder surface 105i, the return light 103b'-2 is an astigmatism for focus control. An aberration is given, the light exits the return light exit surface 105p, passes through the position regulating groove 106d (see FIGS. 8 and 11), and is received at the light receiving position P of the light receiving element 104a. The returned light 103b'-2 is subjected to photoelectric conversion to convert a current output corresponding to a signal on the information recording surface of the CD 61 into a voltage signal, thereby generating a reproduction signal, and the external connection terminal 104 of the light receiving member 104.
b and transmitted to the outside through the printed circuit board 107. A part of the return light 103b'-2 received by the light receiving element 104a is used for focus control by the astigmatism method and tracking control by the three-beam method.

In the optical pickup device 100, the laser light 103a 'emitted from the emission surface 105b,
A wavelength filter or the like for regulating the diameter of the light beam 103b 'may be provided in the optical path between the emission surface 105b and the objective lens 200.

Next, the function of each of the diffraction gratings 105f, 105g, and 105h provided in the composite optical member 105 will be described.

As shown in FIG. 13, the composite optical member 10
5, a laser beam 103a 'emitted from the emission surface 105b,
DVD62 and CD61 for 103b 'respectively
Return light 103a'-2 is diffracted by the first diffraction grating 105f formed on the emission surface 105b.
And 103b'-2. At this time, since the return light 103b'-2 corresponding to the CD 61 has a longer wavelength than the return light 103a'-2 corresponding to the DVD 62,
The diffraction angle of b'-2 is larger than the diffraction angle of the return light 103a'-2 (a diffraction grating uses the principle that the longer the wavelength, the larger the diffraction angle).

By utilizing the difference between the diffraction angles, the laser beam 103a ', 103b' whose distance between the optical axes is D before being diffracted is returned to the return light reflecting surface 105.
When the return lights 103a'-2 and 103b'-2 return to "d", the arrival positions of both light beams coincide with each other.

However, on the return light reflecting surface 105d "of the composite optical member 105, the return lights 103a'-2 and
Simply reflecting 3b'-2 causes the incident angles of the two laser beams to be different, so that the two return lights 103a'-2 and 103b'-2 are directed to the light receiving position P of the light receiving element 104a so as to coincide with each other. It is not possible. In order to correct this, the return light reflecting surface 105d "is provided with a second diffraction grating 105g. That is, the return lights 103a'-2 and 103b'-2 incident on the second diffraction grating 105g are re-wavelength. Return light reflecting surface 105 using the difference in diffraction angle due to the difference in
Return light 103a'-2 and 103b'- reflected at d "
The two optical axes are matched.

Thus, the first diffraction grating 105f
Return lights 103a'-2 and 103 diffracted at
b′-2 can be corrected so that both light are received at the light receiving position P of the light receiving element 104a.
Even when using the light receiving members a and 103b, the light receiving member 104 having one light receiving element 104a can receive both laser beams.

As described above, according to the present embodiment, as shown in FIG. 1, the housing 106 is attached to the optical pickup 100.
, A two-wavelength laser diode 102, a light receiving member 104, and a composite optical member 105 are attached and fixed. The two-wavelength laser diode 102 emits a laser diode 103a that emits a short-wavelength laser for DVD and emits a long-wavelength laser for CD. Composite optical member 1 having laser diode 103b
Reference numeral 05 denotes an incident surface 105a on which light emitted from the two-wavelength laser diode 102 is incident and an emission surface 105b on which light is emitted.
And an optical disk D1 (D
First diffraction grating 105 that diffracts the return light reflected in 2)
f, and a reflection surface 105d for reflecting the return light diffracted by the first diffraction grating 105f to the light receiving member 104, and light having different wavelengths is both transmitted to the light receiving position P of the light receiving member 104 on the reflection surface 105d. Since the second diffraction grating 105g that forms an image with the axes aligned is provided, the single composite optical unit 101 can support the optical pickup device 100 that uses two different wavelengths. Also, the light receiving member 104
Since only one light-receiving member 104 needs to be adjusted and aligned, the cost in the adjustment step does not increase. Furthermore, a two-wavelength laser diode 1
Since the emission surface 105b of the laser light emitted from the optical disk 02 and the return light incidence surface for receiving the return light from the optical disk are made the same, the configuration can be simplified from this point as well.

The two-wavelength laser diode 102 includes a substrate 102a, a cap 102e, and a glass plate 102f.
The light receiving member 104 includes a package 104b having a built-in light receiving element 104a and an external connection terminal 104c provided on the package 104b. Since the composite optical unit 101 is a discrete component, and the composite optical unit 101 is formed using members that are manufactured individually at a low cost, the handling of each member is easy, and the assembling work into the housing 106 is facilitated. Member costs and process costs can be reduced.

The composite optical member 105 is formed of an inexpensive resin material, and the first and second diffraction gratings 105f, 105g,
Since the beam diffraction grating 105h and the cylinder surface 105i are integrally formed at the same time, the molding time can be shortened, and the manufacturing cost of the composite optical member 105 can be further reduced.

Further, since the composite optical member 105 is integrally provided with the beam shaping means, it is possible to reduce the waste of laser power for irradiating the optical disk, and for example, an optical pickup of an optical disk device such as a DVD device requiring a large laser power. Can be applied to The beam shaping means includes an incident surface 105a for the laser light emitted from the two-wavelength laser diode 102, and an emission surface 105b for emitting the laser light emitted from the two-wavelength laser diode 102 and receiving the return light from the optical disk. Since the return light from the optical disk is formed integrally with the reflection surface for guiding the light to the light receiving member, mutual adjustment of these components is not required, and the size and the assembly of the composite optical unit can be reduced. further,
The incident surface 105a of the composite optical member 105 is formed as a cylindrical concave surface, and
By forming the outgoing surface 105b as a cylindrical convex surface having a curvature different from that of the incident surface 105a, a beam shaping means is provided to the composite optical member 105, so that manufacture and design can be performed easily and inexpensively. .

Next, a composite optical member and a composite optical unit according to a second embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 14, in the composite optical member 105 of this embodiment, the incident surface 105a is formed on an inclined surface inclined with respect to the optical axis N of the laser light, and the exit surface 105b is formed with respect to the central axis N '. The laser beam emitted from the two-wavelength laser diode 102 is incident on the plane of the laser beam emitted from the two-wavelength laser diode 102 in the direction of the inclination of the incident surface 105a. The spot shape can be shaped into a circle. That is, as described above, since the spot shape of the laser light emitted from the two-wavelength laser diode 102 is elliptical,
The triangular prism is disposed on the laser light incident side of the composite optical member having the incident surface formed in parallel with the emission surface 105b by making the minor axis direction enter the inclined direction of the incident surface 105a, and the triangular prism is disposed on the triangular prism. As in the case where the laser light is obliquely incident, the spot shape of the laser light emitted from the emission surface 105b can be shaped into a circle.

The angle of inclination θ of the entrance surface 105a with respect to the exit surface 105b is such that the beam expansion rate is m, the composite optical member 105
Where n is the refractive index of the resin material that constitutes the following formula, it can be obtained by θ = sin ⁻¹ {(m ² −1) / (n ² m ² −1)}. From this formula, as an example, m
= 2.5 and n = 1.5, θ = 39.3.

As shown in FIG. 14, the housing 106 of the composite optical unit 101 of the present embodiment is
The storage chamber 106a of the two-wavelength laser diode 102 is provided to be inclined with respect to the storage chamber 106c of the laser diode 05. The cap 102e of the two-wavelength laser diode 102 is inserted into the storage chamber 106a, and the two wavelengths are inserted into the mounting holes 106b. By fitting the base portion 102a of the laser diode 102, the laser light emitted from the two-wavelength laser diode 102 is incident on the incident surface 105a of the composite optical member 105 at a required incident angle at which a required beam shaping effect is obtained. Can be incident.

The other parts are the same as those of the composite optical unit 101 and the composite optical member 105 according to the first embodiment, and the corresponding parts are denoted by the same reference numerals and description thereof will be omitted.

The composite optical unit 101 and the composite optical member 105 according to the present embodiment have the same effects as the composite optical unit 101 and the composite optical member 105 according to the first embodiment. The incident optical surface 105a is inclined with respect to the incident direction of the laser light emitted from the two-wavelength laser diode 102, so that the composite optical member 105 that is easy to design and manufacture and has a highly accurate beam shaping function can be used. It can be easily manufactured.

In addition, in each of the above embodiments, two light sources 103a and 103 having different wavelengths are used as the light emitting members.
b using a two-wavelength laser diode 102 having
Of course, it is also possible to use a light emitting member having three or more light sources having different wavelengths.

[0068]

As described above, since the composite optical member of the present invention is provided with the beam shaping means integrally, it is possible to reduce the waste of the laser power for irradiating the optical disk, and for example, a large size such as a DVD device. The present invention can be applied to an optical pickup of an optical disk device requiring laser power. Further, the beam shaping means may include an incident surface of the laser light emitted from the light emitting member, an emission surface of the laser light emitted from the light emitting member, a return light incident surface for receiving return light from the optical disk, and Since it is formed integrally with the reflection surface for guiding the return light to the light receiving member, mutual adjustment of these parts is not required, and it is possible to reduce the size of the composite optical unit and to facilitate the assembly.

In the composite optical member of the present invention, as a beam shaping means, the incident surface of the composite optical member is formed as a cylindrical concave surface, and the exit surface of the composite optical member has a cylindrical shape having a different curvature from the incident surface. Since it is configured to be formed on the convex surface of the shape, it is easy to design and manufacture, and it is possible to easily manufacture a composite optical member having a highly accurate beam shaping function.

Also, the composite optical member of the present invention is designed so that the incident surface of the composite optical member is inclined with respect to the incident direction of the laser light emitted from the light emitting member as beam shaping means, so that it is designed and manufactured. And a composite optical member having a highly accurate beam shaping function can be easily manufactured.

Further, the composite optical member of the present invention is provided with light diffracting means for splitting the laser beam emitted from the light emitting member into a plurality of light beams on the incident surface of the composite optical member. The present invention can be applied to an optical disk device that performs reproduction of an image.

In the composite optical unit of the present invention, since the composite optical member, the light emitting member, and the light receiving member are attached to the housing, the whole can be made compact and the adjustment between the members can be facilitated. be able to. Also,
Since the composite optical unit is provided with the composite optical member integrally provided with the beam shaping means, it is possible to reduce waste of laser power applied to the optical disc.
The present invention can be applied to an optical pickup of an optical disk device requiring a large laser power, such as a VD device. Also,
The beam shaping means includes an incident surface of the laser light emitted from the light emitting member, an emission surface of the laser light emitted from the light emitting member, a return light incident surface for receiving the return light from the optical disk, and a return light from the optical disk. Is formed integrally with the reflection surface that guides the light receiving member, so that mutual adjustment of these parts is unnecessary,
The composite optical unit can be reduced in size and can be easily assembled.

[Brief description of the drawings]

FIG. 1 is an optical pickup device 10 according to a first embodiment.
It is explanatory drawing which shows 0.

FIG. 2 is a partially sectional perspective view of a two-wavelength laser diode 102 according to the first embodiment.

FIG. 3 is a front view of the composite optical member 105 according to the first embodiment.

FIG. 4 is a left side view of FIG. 3;

FIG. 5 is a right side view of FIG. 3;

FIG. 6 is a view as seen from a direction 6 in FIG. 3;

FIG. 7 is a plan view of a housing 106 according to the first embodiment.

8 is a sectional view taken along line 8-8 in FIG. 7;

FIG. 9 is a left side view of FIG.

FIG. 10 is a right side view of FIG.

FIG. 11 is a view as viewed from a direction 11 in FIG. 8;

FIG. 12 is a partial sectional view taken along line 12-12 in FIG. 1;

FIG. 13 is a functional explanatory diagram of the composite optical member 105 according to the first embodiment.

FIG. 14 is a partial cross-sectional view of a composite optical unit according to a second embodiment.

FIG. 15 is a partial cross-sectional view of a conventional optical unit 50.

FIG. 16 is a partially exploded perspective view of a conventional optical unit 50.

[Explanation of symbols]

 Reference Signs List 61 CD (optical disk) 62 DVD (optical disk) 100 optical pickup device 101 composite optical unit 102 two-wavelength laser diode (light emitting member) 103a, 103b light source 104 light receiving member 104a light receiving element 105 composite optical member 105a incident surface (beam shaping means) 105b Emission surface 105d Reflection surface 105f First diffraction grating 105g Second diffraction grating 105h Three-beam diffraction grating 105j 'Cylindrical surface (regulating surface) 105k' Projection 105p Return light emission surface 105s Space 106 Housing 106c Storage chamber 106c ' Abutment surface (positioning portion) 106d Position regulating groove 106d 'Guide groove 106f Input / output port 106m Position regulating protrusion 106j First regulation receiving portion (regulation receiving surface) 106k Second regulation receiving portion (regulation receiving surface) 200 Objective lens 300Morphism mirror 400 collimating lens 500 carriage (pickup body)

Claims (5)

[Claims] 1. An incident surface of a laser beam emitted from a light emitting member, an exit surface on which the laser beam incident on the incident surface is emitted toward an optical disk, and a return surface on which return light from the optical disk is incident. A light incident surface, diffractive means formed on the return light incident surface, and diffracting the return light in a predetermined direction;
A reflection surface for guiding the return light diffracted by the diffraction means to a light-receiving member, and a beam shaping means for shaping a spot shape of the laser light emitted from the light-emitting member into a circle. Composite optical member. 2. The beam shaping means according to claim 1, wherein said incident surface is formed as a cylindrical concave surface, and said output surface is formed as a cylindrical convex surface having a curvature different from said incident surface. Item 2. The composite optical member according to Item 1. 3. The composite optical member according to claim 1, wherein, as the beam shaping means, the incident surface is inclined with respect to an incident direction of the laser light emitted from the light emitting member. 4. The composite optical member according to claim 1, further comprising an optical diffraction means on said incident surface for dividing laser light emitted from said light emitting member into a plurality of light beams. 5. A composite optical member, a light-emitting member, and a light-receiving member are attached to a housing, and the composite optical member has an incident surface of laser light emitted from the light-emitting member, and an incident surface of the composite optical member. An emission surface from which the emitted laser light is emitted toward the optical disc, a return light incidence surface on which return light from the optical disc is incident, and the return light incidence surface, which diffracts the return light in a predetermined direction. Diffraction means, a reflection surface for guiding the return light diffracted by the diffraction means to the light receiving member, and a beam shaping means for shaping a spot shape of the laser light emitted from the light emitting member into a circle are integrally provided. A composite optical unit, characterized in that a composite optical unit is used.