JP3396608B2 - Optical recording / reproducing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording / reproducing apparatus which has a plurality of optical systems and records, reproduces, or erases information on a plurality of information recording media having different specifications and standards. is there.

[0002]

2. Description of the Related Art A technique for irradiating an optical disc with a light beam and detecting the reflected light to reproduce the information recorded on the optical disc is known as a CD (Compact Disc) or LD (Laser Displacement).
c) Widely used as a playback device. In such an optical disc reproducing apparatus, a light beam emitted from a light source such as a semiconductor laser is converged on an optical disc signal surface by an objective lens, and reflected light from the optical disc is detected by a photodetector to be recorded on the optical disc. The information being reproduced is reproduced.

In recent years, the recording density of such optical discs has been increased, and optical discs having a standard different from that of conventional optical discs have come to exist. For example, the size of a pit, which is a unit for recording information, is about 0.83 μm for a CD, but the size of a DVD
(Digital Video Disc) it is 0.4 μm.
Further, the track pitch, which is the interval between the rows of pits in which information is recorded, is 1.6 μm for CDs, whereas
In DVD, it is reduced to 0.74 μm.

The recording density of an optical disk is based on the size of a light spot of a recording / reproducing light beam emitted from an optical head (pickup) for reading minute pits for recording information formed on the optical disk. Will be decided.

Here, the light spot diameter is the wavelength λ of the light beam used and the numerical aperture (NA) of the objective lens.
Aperture) and is expressed by the following equation using a constant k.

Light spot diameter = k × λ / NA Therefore, in order to reduce the light spot and read a high density optical disc, a light beam with a short wavelength is used, or
Alternatively, it is necessary to use an objective lens having a large NA.

However, since a general optical head has a structure having one objective lens and one light source, an optical head having an objective lens having a large NA, that is, an objective lens corresponding to a high-density optical disc is used. , A conventional low density optical disc cannot be read. This is because in the above optical head for reproducing a high density disc, when the optical disc is tilted with respect to the objective lens, the turbulence of the light spot becomes large and the information cannot be read accurately. Therefore, in many cases, the above optical head cannot be shared for reproduction of high density and low density optical disks.

The disturbance of the light spot is also affected by the thickness of the optical disc. That is, in a thin optical disc, the disturbance of the light spot is small even if the optical disc is tilted. Therefore, a thin disc is often used as a substrate for a high-density optical disc.

From the above, the substrate thickness is 1.2 m, for example.
In order to record / reproduce a m CD and a high-density optical disc having a substrate thickness of 0.6 mm represented by a DVD with the same device, two types of optical systems are required.

Therefore, for example, Japanese Patent Laid-Open No. 6-259804 discloses an apparatus provided with two types of light sources, a semiconductor laser for CD and a semiconductor laser for thin optical disk. Then, each light beam from each of the lasers is focused on the optical disc along substantially the same optical path, and a half mirror or a polarization beam splitter that causes the photodetector corresponding to the optical disc to receive the reflected light from the optical disc is connected to each of the lasers. And the optical disc. As a result, it is possible to record and reproduce two types of optical discs having different substrate thicknesses and recording densities by the same device.

[0011]

By the way, as one means for reducing the size of the device, a pickup having at least the two types of light sources described above is arranged at a corner portion of a drive device for driving an optical disk, There is a way to make effective use of space in the department. However, in this method, it is necessary to arrange the pickup so that the information on the outermost peripheral portion of the optical disc can be reproduced.

However, in the conventional structure provided with two types of light sources, due to the arrangement positions of these two types of light sources, a useless empty space is generated at the corner portion, which hinders miniaturization of the device. The problem arises.

The present invention has been made in order to solve the above problems, and an object thereof is an optical system capable of efficiently utilizing a space at a corner portion of a drive device to downsize the device. It is to provide a recording / reproducing apparatus.

[0014]

In order to solve the above-mentioned problems, an optical recording / reproducing apparatus according to a first aspect of the present invention includes first and second light sources and a first light source from the first light source. A light beam combining means for combining the first and second light beams into substantially the same optical path by reflecting the light beam and transmitting the second light beam from the second light source; and the first light beam. Converge on the first optical disc, and
The substrate thickness of the second light beam is larger than that of the first optical disc.
A thick second <br/> with Ru pick up a converging optical system for converging the optical disks of the above first and second optical disc
A drive device for driving the above-mentioned pick-up at the corners.
And a drive device for mounting the light source on the second light source.
And the light beam synthesizing means is arranged to
Axis is perpendicular to the radial direction of the first or second optical disk
And the first and second light described above.
The source is an optical system of the second light source and the light beam combining means.
The distance between the first light source and the light beam combining means is
It is arranged to be shorter than the optical distance, and in the first light source, the pickup is placed in the corner portion.
So that the optical axis of the first light beam incident on the light beam combining means and the first light beam emitted from the light beam combining means
It is characterized in that it is arranged so that the angle formed by the optical axis of the light beam is less than 90 °.

According to the above arrangement, the first light beam from the first light source and the second light beam from the second light source have substantially the same optical path by the light beam combining means, and the first light beam by the converging optical system. Alternatively, the light is focused on the second optical disc.

Here, the first light source forms an angle between the optical axis of the first light beam incident on the light beam combining means and the optical axis of the first light beam emitted from the light beam combining means. Is less than 90 °. As a result, when the first and second light sources are mounted on the corners of the drive device that drives the first and second optical discs, the first and second light sources are different from those when the angle is 90 °. Can be further brought closer to the corners. This is
While the first and second light sources are arranged at the predetermined positions, the driving device is downsized and the corners are relatively moved to the first position.
It is also synonymous with being able to approach the second light source. Further, in this case, the space at the corner of the drive device is effectively used, and the empty space at the corner can be minimized as much as possible.

Therefore, according to the above configuration, the drive device itself can be downsized by effectively utilizing the space of the corner portion of the drive device, and the optical recording / reproducing device can also be downsized.

Further, the second light beam emitted from the second light source corresponding to the thick second optical disk of the substrate thickness, is incident on the converging optical system becomes more diffuse light, the second light beam The focal position is slightly displaced in the traveling direction of the second light beam. Thereby, the aberration of the second optical disc can be corrected as much as possible.

The first light source is a combination of the light beams.
Optical axis of the first light beam incident on the forming means, and the light beam
Angle formed by the optical axis of the first light beam emitted from the combining means
It is preferable that they are arranged so that the degree is around 80 °.
Good

The optical recording and reproducing apparatus according to the third aspect of the present invention, in order to solve the above problems, according to claim 1 or 2
In the structure, the light beam combining means has a plurality of reflecting surfaces capable of internally reflecting the first light beam from the first light source a plurality of times.

According to the above arrangement , the first light beam is reflected by the plurality of reflecting surfaces of the light beam combining means a plurality of times, so that the optical path of the first light beam is combined with the light beam by one reflection. It becomes longer inside the light beam combining means as compared with the case where the light beams are emitted from the means. As a result, the optical distance between the first light source and the light beam combining means can be shortened by the extension of the optical path. That is, the shortened portion of the distance can be compensated by the extended portion of the optical path. As a result, the area in which the first and second light sources and the light beam combining means are arranged can be made narrower than in the conventional case.

Therefore, the first and second light sources are
The first and second light sources can be further brought closer to the corner when mounted on the corner of the drive device for driving the second optical disk. This means that the driving device can be downsized and the corners can be relatively close to the first and second light sources while the first and second light sources are arranged at the predetermined positions. Is. Further, in this case, the space at the corner of the drive device is effectively used, and the empty space at the corner can be minimized as much as possible.

Therefore, according to the above construction, the drive device itself can be miniaturized by effectively utilizing the space of the corner portion of the drive device, and the optical recording / reproducing device can be miniaturized.

An optical recording / reproducing apparatus according to a fourth aspect of the present invention is the optical recording / reproducing apparatus according to the first, second or third aspect , wherein the wavelengths of the first and second light beams are different from each other. The means is characterized in that a wavelength selection film for selectively transmitting or reflecting the first and second light beams according to the wavelength is formed.

According to the above construction, by forming the wavelength selection film on the light beam synthesizing means, the first light beam can be surely applied to the first optical disc, and at the same time,
A second light beam having a wavelength different from that of the first light beam is
The optical disc can be surely irradiated. Therefore, it is possible to reliably record, reproduce, or erase information on each optical disc by using the first and second light beams having the optimum wavelengths corresponding to the first and second optical discs.

An optical recording / reproducing apparatus according to a fifth aspect of the present invention is the optical recording / reproducing apparatus according to the first, second, third, or fourth aspect , wherein the light beam combining means is provided in a diffusion optical path from the first and second light sources. It is characterized by being provided in.

With the above arrangement, the diffused light of the first light beam or the second light beam incident on the light beam combining means can be reliably guided to the converging optical system.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION [First Embodiment] The following will describe one embodiment of the present invention with reference to FIGS. 1 to 3.

As shown in FIG. 2, the optical recording / reproducing apparatus according to the present embodiment is a drive device as a drive device for driving the pickup 1 and the first and second discs 9 and 10 (see FIG. 1). It consists of the main body 2.

The drive device main body 2 comprises a drive mechanism portion 2a on which the pickup 1 is mounted and a drive mechanism 2b which forms an outer frame of the pickup 1 mounting area. The drive mechanism portion 2a accommodates the first and second disks 9 and 10, and the first and second disks 9 and 10 are displaced by the displacement in the R-S direction in FIG.
The second disks 9 and 10 can be taken in and out. The figure shows a state in which the drive mechanism portion 2a is pulled out from the drive device main body 2 in order to mount an optical disc.

On the other hand, as shown in FIG. 1, the pickup 1 includes a first light emitting / receiving unit 3 (first light source), a second light emitting / receiving unit 4 (second light source), and a synthetic separating element 5.
(Light beam combining means), a collimator lens 6, a reflection mirror 7, and an objective lens 8 are provided. Then, in order to downsize the optical recording / reproducing apparatus, the pickup 1
Are mounted on the corners of the drive mechanism 2b so that the information on the outermost periphery of the first and second discs 9 and 10 can be reproduced.

Although not shown, the first light emitting / receiving unit 3 includes a light source for emitting a light beam 3a, a photodetector for detecting reflected light from the first disk 9, and light emitted from the light source. It is configured to include a hologram optical element that substantially matches the optical axis of the beam 3a with the optical axis of the reflected light.

Further, the second light emitting / receiving unit 4 also has the first
The light emitting / receiving unit 3 has the same configuration. That is, the second light emitting / receiving unit 4 is a light source that emits the light beam 4a and a photodetector that detects reflected light from the second disc 10 having a substrate thickness and recording density different from those of the first disc 9. And the light beam 4a emitted from the light source
And a hologram element that substantially matches the optical axis of the reflected light with the optical axis of the reflected light.

In this embodiment, the first disc 9
The (first optical disc) is, for example, a DVD having a substrate thickness of 0.6 mm and high recording density, and the second disc 10 (second optical disc) is, for example, a substrate thickness of 1.2 mm and a first recording medium.
The recording density of the CD is lower than that of the disk 9. Also,
The wavelength of the light beam 3a is set to be shorter than the wavelength of the light beam 4a.

The combining / separating element 5, the collimator lens 6, the reflecting mirror 7, and the objective lens 8 are the emission point of the light beam 4a in the second light emitting / receiving unit 4 and the second disk 10.
Are arranged in this order from the side of the second light emitting / receiving unit 4 on the optical path of the light beam 4a that connects with the condensing point of the light beam 4a.

It should be noted that, although this figure shows a plan view of the optical recording / reproducing apparatus, here, for the sake of easy understanding of the explanation, the reflecting mirror 7, the objective lens 8, the first disk 9, and the first disk 9 are shown. The second disk 10 is drawn by rotating 90 degrees around the optical axis of the light beam 4a. However, in practice, the reflection mirror 7 and the objective lens 8 are arranged so that the light beam 3a or the light beam 4a is condensed on the first disk 9 or the second disk 10 which is horizontally mounted. (See FIG. 3).

The combining / separating element 5 reflects the light beam 3a from the first light emitting / receiving unit 3 while transmitting the light beam 4a from the second light emitting / receiving unit 4, thereby transmitting the light beam 3a and the light beam 3a. 4a is combined in substantially the same optical path, and has a function of separating reflected light from the first disc 9 or the second disc 10 toward the first light emitting / receiving unit 3 or the second light receiving / receiving unit 4. In this embodiment, the dichroic prism is used.

The composite separating element 5 has a surface 5a which serves as a reflecting surface for the light beam 3a. A wavelength selection film that transmits or reflects the incident light beam based on the wavelength is formed on the surface 5a. This wavelength-selective film is formed by laminating a non-absorption high-refractive index film and a low-refractive index film with an appropriate thickness and number of layers, and by utilizing the interference of light in this thin film, only the light of a specific wavelength range is obtained. Is transmitted, and light in other wavelength regions is reflected.

Therefore, the light beam 3a from the first light emitting / receiving unit 3 is reflected by the surface 5a of the combining / separating element 5 and emitted toward the first disk 9. Further, the light beam 4a from the second light emitting / receiving unit 4 has a surface 5a.
Is transmitted as it is, and is emitted toward the second disk 10 in the substantially same optical path as the light beam 3a.

On the other hand, the reflected light from the first disk 9 is
Similarly, the light is reflected by the surface 5 a of the synthetic separating element 5 and emitted toward the first light emitting / receiving unit 3. On the other hand, the reflected light from the second disk 10 passes through the surface 5a as it is,
The light is emitted toward the second light emitting / receiving unit 4.

That is, in this way, the surface 5 of the composite separation element 5 is
By forming a wavelength selection film on the light beam 3a,
Can be reflected by the surface 5a to surely irradiate the first disk 9 while the light beam 4a is transmitted to the second disk 9a.
The disk 10 can be surely irradiated. Therefore, by using the light beams 3a and 4a having the optimum wavelengths corresponding to the first and second discs 9 and 10, it is possible to surely record, reproduce, or erase information on each optical disc.

The combining / separating element 5 includes a light beam 3a.
In the diffusion optical path 4b, specifically, it is arranged between the first and second light emitting / receiving units 3 and 4 and the collimating lens 6. As a result, the light beam 3 from the synthetic separating element 5 is
Both a and 4a can be surely guided to the same collimator lens 6 and substantially in the same optical path.

The collimator lens 6 converts the light beams 3a and 4a emitted from the synthesizing / separating element 5 into substantially parallel light beams, and the reflection mirror 7 converts the light beams 3a and 4a transmitted through the collimator lens 6 into The light is reflected in the direction toward the first disk 9 or the second disk 10. The objective lens 8 focuses the light beams 3a and 4a on the first disk 9 or the second disk 10.

Therefore, the collimating lens 6, the reflecting mirror 7, and the objective lens 8 focus the light beam 3a from the synthetic separating element 5 on the first disk 9 and the light beam 4a from the synthetic separating element 5. Second disk 10
The converging optical system according to the first and third aspects is configured.

The pickup 1 having such a structure is mounted on the housing 11, and is picked up by the pickup feed mechanism (not shown) along the guide shafts 12a and 12b.
The second disks 9 and 10 are movable in the radial direction, that is, in the PQ direction shown in FIG. The figure shows a state in which the information on the outermost periphery of the first and second discs 9 and 10 is reproduced.

The guide members 12a and 12b are provided so that the angle formed by the long side of the drive mechanism 2b is approximately 45 °. As a result, by the movement (traverse) of the pickup 1, the focus points of the light beams 3a and 4a are formed on the straight line in the radial direction of the optical disc. Further, by arranging the guide members 12a and 12b as described above to configure the traverse mechanism, the pickup 1 can be housed in the corner of the drive mechanism 2b.
It is also possible to effectively use the space at the corners.

In the above structure, when reproducing the first disc 9, the light beam 3a emitted from the first light emitting / receiving unit 3 is reflected by the surface 5a of the combining / separating element 5, and is collimated by the collimating lens 6. The light flux becomes substantially parallel.
The substantially parallel light beam 3 a is focused on the first disk 9 via the reflection mirror 7 and the objective lens 8.

Light beam 3 reflected by the first disk 9
Contrary to the above, a enters the composite separation element 5 through the objective lens 8, the reflection mirror 7 and the collimator lens 6, is reflected by the surface 5a, and returns to the first light emitting / receiving unit 3. In the first light emitting / receiving unit 3, the returning light beam 3a is guided to a photodetector (not shown) by a hologram optical element (not shown).

On the other hand, when reproducing the second disc 10, the light beam 4a emitted from the second light emitting / receiving unit 4 passes through the surface 5a of the synthesizing / separating element 5 and is collimated by the collimating lens 6. Becomes The substantially parallel light beam 4 a is focused on the second disk 10 via the reflection mirror 7 and the objective lens 8.

The light beam 4a reflected by the second disk 10 is, contrary to the above, the objective lens 8, the reflection mirror 7,
Then, the light enters the composite separation element 5 through the collimator lens 6, passes through the surface 5a, and returns to the second light emitting / receiving unit 4. In the second light emitting / receiving unit 4, the returned light beam 4a is guided to a photodetector (not shown) by a hologram optical element (not shown).

Then, the pickup 1 detects information from each track of the first and second disks 9 and 10 by moving in the PQ direction along the guide shafts 12a and 12b by the pickup feed mechanism. And play. The same applies to the recording or erasing of information on the first and second disks 9 and 10.

According to the above construction, two kinds of light sources, that is, the first and second light emitting / receiving units, are provided corresponding to the first and second disks 9 and 10 having different substrate thickness and recording density. 3 and 4 are provided. As a result, the numerical aperture of the objective lens 8 is increased to increase the recording density of the first thin type lens.
The disk 9 and the second disk 10 having a low recording density and a large substrate thickness can be reproduced by the same device. That is, the respective optical discs can be reproduced by the same device without sacrificing the compatibility.

Next, the arrangement positions of the first and second light emitting / receiving units 3 and 4 in this embodiment will be described in detail.

In the second light emitting / receiving unit 4, the optical axis of the light beam 4a incident on the combining / separating element 5 is the guide axis 12a.
It is arranged so as to be perpendicular to 12b. That is, the second light emitting / receiving unit 4 is arranged such that the angle formed by the light beam 4a emitted from the second light emitting / receiving unit 4 and the long side of the drive mechanism 2b is approximately 45 °.

The second light emitting / receiving unit 4 has a second
The optical distance L2 between the light emitting / receiving unit 4 and the composite separating element 5 is shorter than the optical distance L1 between the first light emitting / receiving unit 3 and the composite separating element 5. As a result, the light beam 4a emitted from the second light emitting / receiving unit 4 corresponding to the second disk 10 having a large substrate thickness becomes more diffused light and enters the converging optical system. The focal position is slightly displaced in the traveling direction of the light beam 4a. Therefore, the spherical aberration generated in the second disk 10 can be corrected as much as possible.

On the other hand, in the first light emitting / receiving unit 3, the angle A formed by the optical axis of the light beam 3a incident on the combining / separating element 5 and the optical axis of the light beam 3a emitted from the combining / separating element 5 is 90. It is arranged to be less than °. This makes it possible to reduce the size of the optical recording / reproducing device for the following reasons.

In order to form the converging points of the light beams 3a and 4a on the straight line in the radial direction of the optical disk, the second light emitting / receiving unit 4 must be brought as close as possible to the drive mechanism 2b in the design of the device. However, on the other hand, in order to correct the aberration generated in the optical disc having a thick substrate as much as possible, as described above, the first and second light emitting / receiving units 3 and 4 are set so as to satisfy the relationship of L1> L2. Need to be placed.

Therefore, as shown in FIG. 3, when the angle A is 90 °, for example, the first
When the second light emitting / receiving units 3 and 4 are arranged, the drive mechanism 2b must be bulged outward by the width B in order to avoid contact between the first light emitting / receiving unit 3 and the drive mechanism 2b. Therefore, in this case, the size of the drive mechanism section 2a in which the drive mechanism 2b is formed, and hence the optical recording / reproducing apparatus itself, becomes large.

However, in the structure of this embodiment, the angle A is less than 90 °, so that the second light emitting / receiving unit 4
Even if the drive mechanism 2b is arranged at a position similar to that shown in FIG. 3, the drive mechanism 2b is prevented from expanding outward by the width B and contact between the first light emitting / receiving unit 3 and the drive mechanism 2b is avoided. be able to. Therefore, according to the above configuration, while satisfying the relationship of L1> L2, the first
The second light emitting / receiving units 3 and 4 can both be brought closer to the corner of the drive mechanism 2b. This is synonymous with the fact that the drive mechanism 2b itself can be narrowed by the width B as compared with the conventional case while keeping the pickup 1 at the same position as in the conventional case.

Therefore, according to the above construction, the width C'of the drive mechanism portion 2a shown in FIG. 2 and hence the width C of the drive device main body 2 can be narrowed, and as a result, the optical recording / reproducing apparatus can be miniaturized. can do. Also in this case,
Since the pickup 1 can be housed in the corners of the drive mechanism 2b without loss, the empty space in the corners can be minimized and the space in the corners can be used more effectively.

The number of laminated films of the high refractive index film and the low refractive index film in the wavelength selection film differs depending on the angle A, and the acute the angle A, the more difficult the design of the wavelength selection film becomes. Further, the more acute the angle A is, the more difficult it is to process the prism forming the composite separating element 5. Therefore, from the above, the angle A is 80 °.
Before and after is preferable. [Second Embodiment] The following will describe another embodiment of the present invention in reference to FIG. The members having the same functions as those used in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In this embodiment, a synthetic separating element 15 is used instead of the synthetic separating element 5 used in the first embodiment. The composite separating element 15 is composed of a composite prism of pentagons and triangles, and includes the first light emitting / receiving unit 3
It has surfaces 15a and 15b as a plurality of reflecting surfaces capable of internally reflecting the light beam 3a from a plurality of times.

The surface 15a is a predetermined surface of the pentagonal prism, and is designed to totally reflect the light beam 3a from the first light emitting / receiving unit 3 toward the predetermined surface 15b of the triangular prism. . The surface 15b is coated with the wavelength selection film as described in the first embodiment, and the light beam 4a from the second light emitting / receiving unit 4 is transmitted through the surface 15b while the first light emitting / receiving light is received. The light beam 3a from the unit 3 is adapted to be reflected by the surface 15b.

Further, in the present embodiment, the first light emitting / receiving unit 3 has an optical axis of the light beam 3a incident on the synthetic separating element 5 and an optical axis of the light beam 3a emitted from the synthetic separating element 5. The angle A is about 90 °.

In the above structure, the light beam 3a emitted from the first light emitting / receiving unit 3 is composed of the combining / separating element 1
The light beams are reflected by the surfaces 15a and 15b of No. 5 and are collimated by the collimator lens 6 to become substantially parallel light beams. The substantially parallel light beam 3 a is focused on the first disk 9 via the reflection mirror 7 and the objective lens 8. Further, the light beam 3a reflected by the first disk 9 is, contrary to the above,
The light enters the composite separation element 5 through the objective lens 8, the reflection mirror 7, and the collimator lens 6, is reflected by the surfaces 15b and 15a, and returns to the first light emitting / receiving unit 3.

On the other hand, the light beam 4a emitted from the second light emitting / receiving unit 4 passes through the surface 15b of the synthesizing / separating element 15 and becomes a substantially parallel light beam by the collimator lens 6. The substantially parallel light beam 4 a is focused on the second disk 10 via the reflection mirror 7 and the objective lens 8. Further, the light beam 4a reflected by the second disk 10 is, contrary to the above, the objective lens 8, the reflection mirror 7,
Then, the light enters the composite separation element 5 through the collimator lens 6, passes through the surface 15b, and returns to the second light emitting / receiving unit 4.

When the synthetic separating element 15 is used as in the present embodiment, the optical path of the light beam 3a from the first light emitting / receiving unit 3 is changed by the multiple reflections inside the synthetic separating element 15. It is longer than in the case of form 1. As a result, even if the optical distance between the first light emitting / receiving unit 3 and the combining / separating element 5 is shortened by the extension of the optical path, the aberration correction in the second disk 10 is not affected at all. That is, it is possible to compensate for the shortening of the distance by the extension of the optical path, and even if the first light emitting / receiving unit 3 is brought close to the combining / separating element 15, the aberration correction in the second disc 10 having the thick substrate is corrected. Can be reliably performed.

Therefore, according to the above configuration, the area where the first and second light emitting / receiving units 3 and 4 and the composite separating element 5 are arranged can be made narrower than in the conventional case. As a result, the first and second light emitting / receiving units 3 and 4 can be relatively moved closer to the corner of the drive mechanism 2b.
This is synonymous with the fact that the drive mechanism 2b, the drive mechanism portion 2a, and the drive device main body 2 can be downsized while the first and second light emitting / receiving units 3 and 4 are arranged at predetermined positions. Therefore, according to the above configuration, the optical recording / reproducing device can be downsized. Further, also in the case of the present embodiment, the pickup 1 can be housed in the corner portion of the drive mechanism 2b without loss, so that the first embodiment
Similarly, the space at the corner can be used more effectively.

Further, since the first light emitting / receiving unit 3 can be brought close to the composite separating element 5, even if the angle A is set to about 90 °, the first light emitting / receiving unit 3 may come into contact with the drive mechanism 2b. Absent. Therefore, even if the angle is set to about 90 ° as in the present embodiment, the pickup 1 can be housed in the corner portion of the drive mechanism 2b to downsize the optical recording / reproducing apparatus.

In this embodiment, the synthetic separating element 15
Is composed of a compound prism of pentagon and triangle,
As long as the optical path of the light beam 3a can be extended by a plurality of reflections inside the synthetic separating element 15, the shortened distance between the first light emitting and receiving unit 3 and the synthetic separating element 5 can be compensated for by the extension. For example, the composite separating element 15 may be formed of a prism using another polygon.

[0071]

As described above, the optical recording / reproducing apparatus according to the first aspect of the present invention reflects the first and second light sources and the first light beam from the first light source, while Light beam combining means for combining the first and second light beams into substantially the same optical path by transmitting the second light beam from the second light source, and converging the first light beam on the first optical disc. And the second light beam to the first
A pickup Ru and a thick second converging optical system for converging the optical disks substrate thickness than the optical disk of the above
A drive device that drives the first and second optical disks.
Drive unit that mounts the above-mentioned pickup at the corners.
The second light source and the light beam combining means.
Means that the optical axis of the second light beam is the first or second light beam.
It is placed so that it is perpendicular to the radial direction of the disc.
The first and second light sources above the second light source.
The optical distance from the light beam combining means is the first light source.
And shorter than the optical distance between the light beam combining means and
It is arranged such, and the first light source, the peak
The angle formed by the optical axis of the first light beam incident on the light beam combining means and the optical axis of the first light beam emitted from the light beam combining means is 90 ° so that the lock-up fits in the corner portion . The configuration is such that the number is less than the above.

Therefore, when the first and second light sources are mounted at the corners of the drive device for driving the first and second optical disks, the first and second light sources are mounted on the corners as compared with the case where the angle is 90 °.
And the second light source can be relatively closer to the corner. This is synonymous with the fact that the driving device itself can be miniaturized while the first and second light sources are arranged at predetermined positions. Further, in this case, the space at the corner of the drive device is effectively used.

Therefore, according to the above construction, it is possible to miniaturize the optical recording / reproducing apparatus while minimizing the empty space in the corner portion as much as possible.

[0074] Further, the second light beam emitted from the second light source corresponding to the thick second optical disk of the substrate thickness, is incident on the converging optical system becomes more diffuse light, the second light beam The focal position is slightly displaced in the traveling direction of the second light beam. This brings about an effect that the aberration in the second optical disc can be corrected as much as possible.

The first light source is a combination of the light beams.
Optical axis of the first light beam incident on the forming means, and the light beam
Angle formed by the optical axis of the first light beam emitted from the combining means
It is preferable that they are arranged so that the degree is around 80 °.
Good

As described above, the optical recording / reproducing apparatus according to the third aspect of the present invention has the structure of the first or second aspect .
The light beam combining means has a plurality of reflection surfaces capable of internally reflecting the first light beam from the first light source a plurality of times.

Therefore, the optical distance between the first light source and the light beam combining means can be shortened by the extension of the optical path of the first light beam. The area where the beam synthesizing means is arranged can be made narrower than in the conventional case.

Therefore, when the first and second light sources are mounted at the corners of the drive device for driving the first and second optical disks, the first and second light sources are relatively positioned at the corners. You can get closer. This is synonymous with the fact that the driving device itself can be miniaturized while the first and second light sources are arranged at predetermined positions. Also,
In this case, the space at the corner of the drive device is also effectively used.

Therefore, according to the above configuration, the first aspect
Alternatively, in addition to the effect of the configuration of 2 , the optical recording / reproducing apparatus can be downsized while minimizing the empty space at the corners.

As described above, in the optical recording / reproducing apparatus according to the invention of claim 4 , in the structure of claim 1, 2 or 3 , the wavelengths of the first and second light beams are set to be different from each other. The light beam combining means includes the first
And a wavelength selection film that selectively transmits or reflects the second light beam according to the wavelength.

Therefore, in addition to the effect of the structure of claim 1, 2 or 3 , information for each optical disk is obtained by using the first and second light beams having the optimum wavelengths corresponding to the first and second optical disks. There is an effect that the recording, reproduction, or erasing can be surely performed.

As described above, in the optical recording / reproducing apparatus according to the fifth aspect of the present invention, in the configuration of the first, second, third, or fourth aspect , the light beam combining means includes the first and second optical beam combining means.
This is provided in the diffusion optical path from the light source.

Therefore, in addition to the effect of the first, second, third, or fourth structure, the diffused light of the first light beam or the second light beam incident on the light beam combining means is surely guided to the converging optical system. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a plan view showing a schematic configuration of an optical recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing a state in which a drive mechanism unit is pulled out from a drive device body in the optical recording / reproducing device.

FIG. 3 is a plan view showing an example in which the drive mechanism in the drive mechanism section is enlarged.

FIG. 4 is a plan view showing a schematic configuration of an optical recording / reproducing apparatus according to another embodiment of the present invention.

[Explanation of symbols]

3 First light emitting / receiving unit (first light source) 3a light beam (first light beam) 4 Second light emitting / receiving unit (second light source) 4a light beam (second light beam) 5 Synthetic separation element (light beam synthesizing means) 6 Collimating lens (converging optical system) 7 Reflection mirror (converging optical system) 8 Objective lens (converging optical system) 9 First disc (first optical disc) 10 Second disc (second optical disc)

─────────────────────────────────────────────────── --Continued from the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G11B ^7/ 09-7/22

Claims (5)

(57) [Claims] 1. The first and second light sources and the first light beam from the first light source are reflected, while the second light beam from the second light source is transmitted, whereby the first light beam is transmitted. And a light beam synthesizing means for synthesizing the second light beam in substantially the same optical path, the first light beam is converged on the first optical disc, and the second light beam has a substrate thickness larger than that of the first optical disc. a thick second converging optical system for converging the optical disk and the pickup Ru comprising a driving device for driving the first and second optical disk
There is a drive unit that mounts the above-mentioned pickup at the corner
And the second light source and the light beam combining means are
The optical axes of the two light beams of the first or second optical disk are
The first and second light sources are arranged so as to be perpendicular to the radial direction, and the first and second light sources are the second light source and the light source.
The optical distance from the beam combining means is higher than that of the first light source.
It should be shorter than the optical distance from the light beam combining means.
And the first light source is arranged such that the pickup fits in the corner.
So that the optical axis of the first light beam incident on the light beam combining means and the first light beam emitted from the light beam combining means
An optical recording / reproducing apparatus, wherein the optical recording / reproducing apparatus is arranged so that an angle formed by an optical axis of a light beam is less than 90 °. 2. The first light source is the light beam combining means.
Optical axis of the first light beam incident on the
The angle formed by the optical axis of the first light beam emitted from the step is 8
The optical recording / reproducing apparatus according to claim 1, wherein the optical recording / reproducing apparatus is arranged so as to be around 0 ° . Wherein said light beam combining means, claims, characterized in that it has the first of the first light beam a plurality of reflection surfaces capable of reflecting a plurality of times inside the light source
1 or the optical recording and reproducing apparatus according to 2. 4. The wavelengths of the first and second light beams are relative to each other.
Differently set, the light beam combining means,
The first and second light beams are selectively transmitted depending on the wavelength.
Optical recording and reproducing apparatus according to claim 1, 2 or 3, characterized in that a wavelength selective film for over-or reflection are formed. 5. The light beam synthesizing means comprises:
Optical recording and reproducing apparatus according to claim 1, 2, 3 or 4, characterized in that are found provided in the diffusion optical path from the second light source.