JPH09120568A - Laser module for recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the laser module which is low in cost, small in size and effectively reproduces and records the information recorded on various optical disks having plural standards. SOLUTION: Semiconductor laser diodes(LDs) 1 and 2 which are correspondingly provided to optical recording medium surfaces having different laser beam wavelengths to conduct data recording and reproducing and hologram elements 10 which respectively guide the laser beams emitted from the LDs 1 and 2 to an optical recording medium surface are integrated together to form a laser module. By using the laser module above, recording and reproducing of a high density CD, a conventional CD medium and a rewritable CD-R, recording and reproducing of a phase transition type optical disk and recording and reproducing of plural optical disk media are accommodated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser module, and more particularly to recording / reproducing data on / from first and second optical recording medium surfaces having different laser light wavelengths required for recording / reproducing data. The present invention relates to a laser module used in a recording / reproducing apparatus.

[0002]

2. Description of the Related Art FIG. 6 and FIG. 7 show the structure of a recording / reproducing apparatus including a conventional laser module. First, the first conventional example shown in FIG. 6 has a wavelength of 635 [n
m] single wavelength semiconductor laser diode (hereinafter, L
(Referred to as D), and the numerical aperture (Numerical Aper) of laser light near the optical axis.
NA conversion hologram 17 for converting
An objective lens 15 having a high NA (for example, NA = 0.5 to 0.6), and an actuator 18 which holds the objective lens 15 and the NA conversion hologram 17 and drives the disc in two axes in the focus direction and the track direction. , And an optical base 19. Reference numeral 14 in the drawing is an optical disk medium. The alternate long and short dash line in each drawing referred to in the following description represents the center of the optical axis.

The laser beam 12 output from an LD (not shown) in the LD module 21 passes through the hologram element 21h in the module 21 and enters the NA conversion hologram 17. The NA conversion hologram 17 has a coaxial diffraction grating 17a formed in a predetermined opening near the optical axis, diffracts only the laser light incident on the area of the diffraction grating 17a, and filters the laser light in other areas. The transparency is set to almost 100%. Therefore, NA conversion hologram 1
The laser light incident on the beam No. 7 becomes two types of laser light 12m (solid line) and 12n (broken line) shown in the figure, and has a high NA.
It is incident on the objective lens 15. These laser lights have different apparent emission points in the optical axis direction when viewed from the objective lens. Therefore, the focusing position by the objective lens 15 also differs in the optical axis direction, and as a result, the two focal points 14m, 14m
n is formed, and two types of NA on the disk medium side are also formed.

From the above, a high density CD-ROM (Com
pact Disc-Read Only Memor
During the reproduction of y), the information is reproduced by the focused spot 14m of the laser light 12m having a large NA. When reproducing an optical disk of normal density, information is reproduced by the focused spot 14n of the laser light 12n having a small NA.

Next, the second conventional example shown in FIG. 7 will be described. In the figure, (a) is a plan view of the recording / reproducing apparatus, (b) is a side view of the same, and the same portions as those in FIG. 6 are denoted by the same reference numerals.

Referring to FIG. 1, the device of this conventional example has an LD module 21 in which an LD of a single wavelength is mounted and a high NA (for example, NA = 0.5) as in the case of the first conventional example.
˜0.6) objective lens 15 and low NA (for example NA =
The objective lens 24 of 0.35 to 0.45) and an actuator 25 that holds these two lenses 15 and 24 and drives them in the focus direction and the track direction of the disk are configured. Then, the actuator 25 having a lens switching function switches lenses having different NAs as shown by an arrow Y depending on the optical disk medium to be reproduced, so that the NAs 15a and 24a in the drawing are focused respectively.
And two types of spots having different diameters are formed.

In the above two conventional examples, the LD
The same operation is achieved not only when using the module but also when arranging the optical components individually.

[0008]

The conventional recording / reproducing apparatus described above has some problems.

First, in the first conventional example (FIG. 6), since two laser beams are always produced by the diffraction of the NA conversion hologram 17, the optical efficiency of the entire optical system is greatly reduced, and the signal to noise ratio (Signal / Signal / There was a problem in the life of the laser diode and the like. Further, since the laser has a single wavelength, CD-R (Compact Disc-
Recording on a write-once optical disc such as a recordable disc,
There was a problem that it was not possible to cope with reproduction sufficiently.

Next, in the second conventional example (FIG. 7), although the light efficiency is secured, the actuator must hold two types of objective lenses and follow the optical disc with high accuracy, and the movable part However, there is a problem that it is difficult to balance the weight and balance. Furthermore, like the first conventional example,
Since the laser has a single wavelength, there is a problem that recording and reproducing of a write-once optical disc such as a CD-R cannot be sufficiently dealt with.

A laser module capable of solving this problem has already been filed by the present applicant (Japanese Patent Application No. 7-137675). This is because by using two LD modules with different output light wavelengths,
This is an optical recording / reproducing apparatus that can efficiently use laser light and is sufficiently compatible with recording media such as CD-R.

The structure of the optical recording / reproducing apparatus disclosed in the same application is shown in FIG. In the figure, the laser module includes an LD module 21 including a short-wavelength LD having a wavelength of 635 [nm], a photodiode (hereinafter, referred to as PD), a hologram element, and the like, and a wavelength 7
An LD module 22 including an LD and a PD of 80 [nm], a hologram element, a polarization beam splitter 26, a wavelength filter 16, an objective lens 15,
It is configured to include a wavelength filter 16 and an objective lens 15 and an actuator (not shown) that drives in two axes in the focus and track directions.

The LD modules 21 and 22 use a three-beam method or a push-pull method as a track error detection method, and a hologram element 2 using a known method such as a beam size method or a knife edge method as a focus error detection method.
1h, 22h, etc. are included.

In the above optical information recording / reproducing apparatus, a high density CD-ROM (Digital Video Disc) is used.
c; DVD) reproduction, normal density CD format disc reproduction, write-once disc (CD-R) reproduction, recording, etc., and is configured for recording multiple standard optical disc media with one optical pickup. The feature is that it can be played. In the following description, a high density optical disk medium is represented by 14k, and a normal density optical disk medium such as a normal CD is represented by 14c.

First, when reproducing a high density CD-ROM or the like,
To obtain a high-resolution spot, for example, the wavelength 635
A short wavelength laser near [nm] is required. Wavelength 635
The laser light 12 (solid line) output from the LD in the LD module 21 of [nm] is transmitted through the hologram element 21h in the module 21 and the polarization beam splitter 26. Further, the laser light 12 passes through the wavelength filter 16.

Here, a wavelength selection region 16a for limiting the opening of the laser beam 13 (broken line) having a wavelength of 780 nm described later is formed on the entrance surface of the wavelength filter 16 by a predetermined opening. Laser light 12 of wavelength 635 [nm]
Is the wavelength selection region 16 formed by this predetermined opening.
a is almost transmitted, and a high NA (for example, NA = 0.5 to
0.6) toward the objective lens 15. And wavelength 6
The laser light 12 of 35 [nm] is condensed by the objective lens 15 and forms a minute spot on the information surface of the high density optical disc medium 14k.

The reflected light from the disk, which has undergone the modulation of the pit surface, travels again to the LD module 21 along the same path,
P is diffracted by the hologram 21h and is not shown in the module.
It is focused on D and converted into an electrical signal.

On the other hand, a laser having a wavelength of 780 [nm] is required at the time of reproducing an optical disk medium having a normal density, reproducing a CD-R, and recording, because of the pit size and the recording and reproducing characteristics. The laser light 13 output from the LD (not shown) in the LD module 22 having a wavelength of 780 [nm] is emitted from the module 22.
The light is transmitted through the hologram element 22h therein and is reflected by the deflection beam splitter 26.

Further, the aperture of the reflected light is limited by the wavelength selection region 16a of the wavelength filter 16 described above,
It goes to the objective lens 15. The laser light 13 having a wavelength of 780 [nm] is condensed by the objective lens 15 and forms a minute spot on the information surface of the disk medium 14c such as a CD-R disk. The reflected light from the disc, which has undergone the modulation of the pit surface, again travels to the LD module 22 along the same path, is diffracted by the hologram 22h, is condensed on a PD (not shown) in the module, and is converted into an electric signal.

At this time, the wavelength selection region 16a has a wavelength of 63
Most of the laser light near 5 [nm] is transmitted, and the wavelength 78
It has a characteristic of almost reflecting a laser beam in the vicinity of 0 [nm]. Further, the laser beam 12 of the LD module 21 having a wavelength of 635 [nm] enters the polarization beam splitter 26 as p-polarized light P, and an LD having a wavelength of 780 [nm] is emitted.
The laser light 13 of the module 22 is set so as to enter the s-polarized light S.

However, in the optical information recording / reproducing apparatus previously filed by the applicant of the present application, while recording / reproducing of a plurality of optical disk media is possible, two LD modules are required, resulting in high cost and further the optical pickup itself. There was a defect that it could not be downsized. That is, since a plurality of optical elements are integrated in the LD module, it is very advantageous for downsizing and easy manufacturing of the optical pickup, but considering the manufacturing facilities of the module, the number of manufacturing steps, etc., two modules are required. Manufacturing separately leads to higher costs. The number of parts such as hologram elements, PDs, and other packages will increase.

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and an object thereof is an inexpensive and compact recording / reproducing apparatus laser capable of efficiently reproducing and recording information on optical disc media of a plurality of standards. To provide a module.

[0023]

A laser module according to the present invention records and reproduces data on and from first and second optical recording medium surfaces having different laser light wavelengths required for recording and reproducing data. A laser module for use in a recording / reproducing apparatus for performing the above, and first and second laser elements which are provided corresponding to the surfaces of the first and second optical recording media and which output laser beams having different wavelengths, respectively. The laser light output from these laser elements
Optical means for converging light on the surface of the optical recording medium, and these laser elements and optical means are integrally integrated.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of the present invention is as follows.

The first and second optical recording medium surfaces are provided so as to correspond to each other and output laser beams having different wavelengths from each other.
And the second laser element and the optical means for condensing the laser light output from these laser elements on the surfaces of the first and second optical recording media are integrally integrated. By using this laser module, the first and second laser beams having different wavelengths of laser light required for recording and reproducing data are provided.
Data is recorded / reproduced on / from the optical recording medium surface. Therefore, recording / reproduction of a plurality of optical disc media such as recording / reproduction of a high-density optical disc medium, a normal-density optical disc medium, a write-once CD-R, a phase change optical disc, and the like can be performed.

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram showing the configuration of an embodiment of the laser module according to the present invention, and the same portions as those in FIG. 8 are designated by the same reference numerals. In the figure, a laser module according to an embodiment of the present invention includes an LD module 20 that outputs two laser beams having different wavelengths and an objective lens 1 having a high NA (for example, NA = 0.5 to 0.6).
5, an actuator 18, and an optical base 19.

Further, FIG. 1 is a configuration diagram showing a more detailed configuration of the LD module 20 of FIG. 2, (a) being a plan view,
(B) is a side view. However, the same figure (a) and figure (b)
In, the scales of the light spots do not always match.
In the figure, this laser module is used for normal CDs and CDs.
-R, LD (for example, a wavelength of 780 [nm]) 1 that emits light when reproducing or recording a phase change optical disk, and short wavelength that emits light when reproducing high density CD, DVD, or high density CD-ROM An LD (for example, a wavelength of 635 [nm]) 2 and heat sinks 3 and 4 which are provided corresponding to these two LDs 1 and 2 and hold the corresponding LDs, and which are mounted on a PD described later and two LDs 1, A silicon substrate 7 holding a wavelength selection prism 5 that efficiently transmits and reflects laser light from the LD 2, a heat sink 3, 4 and a wavelength selection prism 5, and a plurality of divided PDs 11 are laminated on the LD side surface of the silicon substrate 7. , And the hologram element 10.

The laser module shown in the figure is an example of a configuration in which the beam size method is used for focus error detection and the three-beam method is used for track error detection. That is, a diffraction grating surface 10b for forming three beams is formed on the LD-side surface of the hologram element 10. Also, the hologram element 1
On the other surface of 0, when the return light from the optical disc is diffracted and guided to the PD 11, the first-order light 13g, 13b and 13h (12g, 12b and 12h) and the second-order light 13 of the diffracted light are provided.
A hologram grating 10a designed to have different focal lengths from i, 13e and 13j (12i, 12e and 12j) is formed. The PD 11 has a total of 10 divided light receiving portions A, B, C, D, E, F, G, H, I.
And J.

FIG. 3 is a configuration diagram showing an example of the configuration of the wavelength selection prism 5. In the figure, the wavelength selection prism 5
Are two triangular prisms 51 and 52 having so-called hot mirror surfaces 5a and 5b that transmit almost all laser light having a wavelength of 635 [nm] and almost reflect laser light having a wavelength of 780 [nm], and have a wavelength of 635 [nm]. It has so-called cold mirror surfaces 5c and 5d that reflect almost all laser light and almost transmit laser light having a wavelength of 780 [nm] 2
The configuration includes four triangular prisms 53 and 54, and these four prisms 51 to 54 are accurately bonded together.

Next, the operation of the present laser module having the configuration shown in FIGS. 1 to 3 will be described.

When reproducing a high density optical disk medium such as a CD-ROM, the short wavelength side LD2 in the two wavelength LD module 20 is caused to emit light. The laser light 12 output from the LD 2 enters the wavelength selection prism 5, is efficiently reflected by the cold mirror surfaces 5c and 5d, and enters the hologram element 10. The laser beam 12 is diffracted into three beams by the diffraction grating surface 10b of the hologram element 10 and is also diffracted by the next hologram grating surface 10a, but the 0th order transmitted light goes to the wavelength filter 16 of FIG. The wavelength filter 16 has the same configuration as that described above, and almost transmits the laser light 12 having a wavelength of 635 [nm]. The laser light 12 that has passed through the wavelength filter 16 is converged into a minute spot by the objective lens 15 and focused on the high density optical disk medium 14k.

The reflected light from the disk which has undergone the modulation of the information pits of the high density optical disk medium 14k travels to the LD module 20 again through the same path. This reflected light is diffracted by the hologram grating surface 10a of the LD module 20,
The first-order diffracted light is converted into electric signals in the light receiving portions A, B, C, G, and H of the PD, and the second-order diffracted light is converted into electric signals in the light receiving portions D, E, F, I, and J of the PD.

At this time, as shown in FIG. 1, the hologram pattern on the hologram grating surface 10a is such that the first-order diffracted light and the second-order diffracted light are separated from the light-receiving surface of the PD 11 by a predetermined distance a in the optical axis direction. It is designed to focus away from each other. As a result, the three beams of return light diffracted by the diffraction grating surface 10b are diffracted by the hologram grating surface 10a, and as shown in FIG. 1, a total of six circular spots 12b, 12g, 12h, 12e. , 12i and 12
j is focused on a predetermined position on the PD 11. It is assumed that FIG. 1 shows a state where the laser light is just focused on the optical disc.

Here, the information signal of the optical disc, the focus error detection signal, and the track error detection signal are created by the following calculation.

Information signal RF = A + B + C + D + E + F Focus error signal FE = (A + C + E)-(B + D +
F) Track error signal TE = (G + I)-(H + J) Note that a known beam size method is used for focus error detection, and a three-beam method is used for track error detection.

Next, a normal CD medium is reproduced and rewritable C
The operations in the case of recording and reproducing the DR and recording and reproducing the phase change medium will be described.

In this case, the LD 1 of the wavelength 780 [nm] in the LD module 20 is made to emit light. The laser light 13 output from the LD 1 enters the wavelength selection prism 5, is efficiently reflected by the hot mirror surfaces 5 a and 5 b, and travels toward the hologram element 10. Upon passing through the hologram element 10, as in the case of the laser beam 12 having a wavelength of 635 [nm] described above, it is incident on the wavelength filter 16 by diffraction of three beams and zero-order transmission of the hologram surface. Wavelength filter 16
Then, the laser light 13 having a wavelength of 635 [nm] that is incident on the wavelength selection region 16a formed in the predetermined opening is totally reflected, and only the laser light in the vicinity of the other optical axis is transmitted to the objective lens 15. Since the numerical aperture NA of this light is limited by the wavelength filter 16, the spot condensed by the objective lens has an optimum size for the pit shape of the optical disc medium 14c of normal density and is focused. The reflected light from the optical disc medium that has been modulated by the information pit travels to the LD module 20 along the same path.

The reflected light from the optical disk medium is diffracted by the hologram grating surface 10a of the LD module 20 and
The second-order diffracted light is converted into electric signals in the light receiving portions A, B, C, G, and H of the PD, and the second-order diffracted light is converted into electric signals in the light receiving portions D, E, F, I, and J of the PD. At this time, the first-order diffracted light and the second-order diffracted light are reflected by the PD as shown in FIG.
The light receiving surface of the lens 11 is opposed to the light receiving surface 11 by a predetermined distance a and is focused. Thereby, the diffraction grating surface 10b
The return light of the three beams diffracted by is the hologram surface 10a.
A total of 6 as shown in FIG.
Circular spots 12b, 12g, 12h, 12e, 1
2i and 12j are condensed on a predetermined position of PD11. It is assumed that FIG. 1 shows a state where the laser light is just focused on the optical disc medium.

In the case of a laser beam having a wavelength of 780 [nm], since the diffraction angles on the diffraction grating surface 10b and the hologram surface 10a are larger than those of a laser beam having a wavelength of 635 [nm], as shown in FIG. Spots 13b, 13e, 13g,
The light beams 13h, 13i, and 13j are condensed at positions slightly shifted in the respective diffraction angle directions. However, by devising the shape of the light receiving surface of the PD 11, it is possible to create the same conditions as in the case of laser light having a wavelength of 635 [nm].

As for the focal position shift in the optical axis direction caused by the difference in wavelength, the distance between LD1 and the wavelength selection prism 5 and the distance between LD2 and the wavelength prism 5 are set so that the focal position shift is corrected. Can be solved with. The lattice pattern, the lattice depth, etc. on the hologram surface are set so that the utilization efficiency of both laser beams can be compatible. The information signal, the focus error signal, and the track error signal are obtained by the same calculation as that described above.

Further, in the case of recording on a CD-R or a phase change optical disk, a wavelength of 78 is obtained by using a pulse transmission circuit (not shown).
Information is recorded by driving the LD 1 of 0 [nm].
The focus and track error detection methods are the same as during reproduction.

By the way, regarding the wavelength selection prism,
Configurations other than the configuration shown in FIG. 3 are possible. FIG.
Shows another configuration example of the wavelength selection prism.
In the figure, the wavelength selection prism 6 has a wavelength of 780 [n
m] of the laser light 12 is efficiently reflected and the wavelength of 635 [n
The prism 61 having the hot mirror surface 6a that transmits the laser light of m] and the prism having the cold mirror surface 6b that most reflects the laser light of the wavelength 635 [nm] and efficiently reflects the laser light of the wavelength 780 [nm]. 62, and these two prisms 61 and 62 are vertically laminated.

In this case, the mounting position of the LD 1 having a wavelength of 780 [nm] is shifted in the optical axis direction by changing the thickness of the heat sink 3. The focus position shift in the optical axis direction on the PD side caused by the difference in wavelength is the same as in the above embodiment.
Correction is performed by the distance between each LD and the incident surface of the wavelength selection prism.

If the wavelength selection prism 6 of this example is used, the wavelength 635 [n] seen from the objective lens 15 is the same as the prism 5.
m] and the optical emission point of the laser light of wavelength 780 [nm] is the center point O of the xy coordinates shown in FIG.
The image height does not occur at the converging point by the objective lens 15. Moreover, since the number of prisms to be bonded is small, the processing accuracy of the prisms is improved.

Next, an example of the structure when the wavelength selection prism is not used will be described with reference to FIG. However, the scales of the light spots do not necessarily match in the plan view (a) and the side view (b). In FIG. 5, the same parts as those in FIGS. 1 to 4 are indicated by the same reference numerals.

The laser module shown in FIG.
Instead of the wavelength selection prism, a simple total reflection mirror 9 is arranged. The laser lights from the LD1 and LD2 having two wavelengths are held on one heat sink 8 so that the laser lights can be made incident on the mirror 9 from the same direction.

The positional deviation of the returning light spot due to the difference in the light emitting points in the x-axis direction is corrected by the shape of the PD 11. That is, since the PD 11 has a shape in which a part of the light receiving surface is long in the direction parallel to the x-axis as shown in the figure,
The positional deviation of the returning light spot is corrected.

The optical emission points of the laser light of two wavelengths seen from the objective lens 15 are, as shown in FIG.
In the case of an LD with a wavelength of 780 [nm], a wavelength of 6
In the case of a 35 [nm] LD, it is near O2. For this reason,
In the optical path system from each light emitting point to the objective lens 15, laser beams of two wavelengths are independent, and there is no need to combine and separate the lights as in the above-described embodiment.

The operation of this laser module will be described with reference to FIGS. First, when reproducing a high density CD medium, the LD 2 having a wavelength of 635 [nm] is caused to emit light. The laser beam 12 output from the LD 2 reflects the reflection mirror 9
Then, it efficiently passes through the hologram element 10, the wavelength filter 16 and the objective lens 15 and focuses it on the optical disc medium 14k. At this time, the hologram element 10 and the wavelength filter 16
Since the operation received by is the same as that of the laser module of FIG. 1, the description thereof will be omitted.

The return light from the optical disk is diffracted by the hologram surface 10a, and six circular spots 12g, 12b are formed at positions substantially equidistant from the optical emission point O2 on the x axis shown in the drawing. 12h, 12i, 12e and 12j
Is condensed on the PD 11. For how to create the information signal, focus error detection signal, and track error detection signal,
This is similar to the case of the laser module of FIG. 1 described above.

When reproducing a normal CD, reproducing a CD-R or a phase change optical disk, and recording, an LD having a wavelength of 780 [nm] is used.
Make 1 emit light. Laser light 13 output from LD1
Is efficiently totally reflected by the reflection mirror 9 and the hologram element 1
0, the wavelength filter 16 and the objective lens 15, and focuses on the optical disk medium 14c. At this time, the effects exerted by the hologram element 10 and the wavelength filter 16 are the same as in the case of FIG. 1 described above, and therefore the description thereof will be omitted.

The return light from the optical disk medium is diffracted by the hologram surface 10a, and six circular spots 13g are formed at positions substantially equidistant from the optical emission point O1 on the x axis shown in the drawing. 13b, 13h, 13i, 13e and 13j are condensed on the PD 11. The method of creating the information signal, the focus error detection signal, the track error detection signal, the pulse driving during recording, and the like are the same as in the case of the laser module of FIG. 1 described above.

The focal position shift in the optical axis direction caused by the difference in wavelength is the same as in the case of FIG.
This can be solved by setting the distance between and the distance between the LD 2 and the reflection mirror 9 so that the focal position shift is corrected.
The grating pattern on the hologram surface and the grating depth are also set so that the utilization efficiency of laser light of both wavelengths can be compatible.

By the way, in the configuration shown in FIG.
Since the two LDs are arranged on the x-axis, a slight image height is generated in the minute spot condensed by the objective lens 15. However, this can be solved by setting the distance between LD1 and LD2 so as to sufficiently satisfy the image height characteristic of the objective lens 15.

In each of the above embodiments, the beam size method is used for focus error detection, and 3 is used for track error detection.
Although the beam method is used, it is obvious that other detection methods such as the Fuco method and the push-pull method can be applied depending on the pattern design of the hologram element and the shape design of the PD light receiving surface.

[0057]

As described above, according to the present invention, one P
By integrating the D and the hologram element so that the two LDs can be used in common, two laser beams having different wavelengths can be efficiently used, and high density CDs, normal CD media, and rewritable CD-Rs can be used. There is an effect that it is possible to realize a low-priced and small-sized laser module that can be applied to a plurality of optical disk media such as recording and reproduction, and further recording and reproduction of a phase change optical disk.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of a laser module according to an embodiment of the present invention, (a) is a plan view and (b) is a side view.

FIG. 2 is a block diagram showing a configuration of a main part of a recording / reproducing apparatus using a laser module according to an embodiment of the present invention.

3 is a configuration diagram showing a configuration of a wavelength selection prism in FIG.

FIG. 4 is a configuration diagram showing another configuration example of the wavelength selection prism.

5A and 5B are configuration diagrams showing a configuration when a mirror is used instead of the wavelength selection prism in the laser module of FIG. 1, FIG. 5A is a plan view, and FIG. 5B is a side view.

FIG. 6 is a block diagram showing a configuration of a conventional laser module.

FIG. 7 is a block diagram showing the configuration of another conventional laser module, in which (a) is a plan view and (b) is a side view.

FIG. 8 is a block diagram showing a configuration of a laser module according to another application of the applicant of the present application.

[Explanation of symbols]

 1, 2 Semiconductor laser diode 3, 4 Heat sink 5, 6 Wavelength selection prism 7 Silicon substrate 9 Total reflection mirror 8 Heat sink 10 Hologram element 10a Hologram grating surface 10b Diffraction grating surface 11 Photodiode 15 Objective lens 16 Wavelength filter 18 Actuator 20 LD module 51-54 triangular prism 61, 62 prism

Claims (5)

[Claims] 1. A laser module used in a recording / reproducing apparatus for recording / reproducing data on / from first and second optical recording medium surfaces having different laser light wavelengths required for recording / reproducing data. The first and second laser elements that are provided corresponding to the surfaces of the first and second optical recording media and that output laser light having different wavelengths, respectively, and laser light output from these laser elements A laser module comprising: an optical means for guiding the surfaces of the first and second optical recording media, wherein the laser element and the optical means are integrated together. 2. The optical means is provided corresponding to the first and second laser elements, respectively, and reflects the laser light output from the corresponding laser elements to reflect the first and second laser elements, respectively.
2. The laser module according to claim 1, further comprising a prism having first and second reflecting surfaces that lead to the surface of the optical recording medium. 3. The optical means has a reflecting surface which is provided corresponding to the first laser element and which reflects a laser beam output from the laser element and guides the laser beam to the surface of the first optical recording medium. A second prism having a first prism and a reflecting surface which is provided corresponding to the second laser element and which reflects a laser beam output from the laser element and guides it to the second optical recording medium surface.
2. The laser module according to claim 1, further comprising: 4. The optical means includes a mirror having a reflecting surface that reflects the laser beams output from the first and second laser elements and guides the laser beams to the surfaces of the first and second optical recording media, respectively. The laser module according to claim 1, wherein: 5. A light-receiving element having a light-receiving surface for outputting a signal necessary for recording / reproducing the data according to light irradiated on the light-receiving surface; and a light-receiving element from the first and second optical recording medium surfaces. The laser module according to claim 1, further comprising a condensing unit that guides reflected light to the light receiving surface.