JP2002042368A - Optical pickup and optical disk device - Google Patents

Abstract

(57) [PROBLEMS] To provide an optical element having a configuration including a parallel plate-shaped hologram element for separating incident light and reflected light in an optical element, while eliminating the need for a holding member for each optical element, Provided is an optical pickup in which elements can be arranged with high precision and the whole can be reduced in size and thickness at low cost. SOLUTION: A laminated optical element 13 in which a plurality of parallel plate-shaped optical elements 12 and 5 including a hologram element 6 are laminated.
By fixing or bonding the surfaces of the optical elements 6, 12, 5 to each other, the position of each element in the optical axis direction can be fixed, and a separate holding member is not required. Each optical element 6,12,
5 originally has a high surface accuracy of the incident surface because it functions as an optical element, and its thickness accuracy and parallelism are also generally very high, so that the position in the optical axis direction can be arranged with high accuracy. . Also, the reference plane 1 for arranging the light receiving elements 8a and 8b in the optical axis direction.
4 and the incident end face 13a are matched with each other,
The positions a and 8b of the laminated optical element 13 in the optical axis direction can be determined with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup for separating incident light from a light source and reflected light from an optical information recording medium using a hologram element, and an optical disk apparatus using the optical pickup.

[0002]

2. Description of the Related Art Recently, CD (Compact
With respect to a disk, a DVD (Digital Versatile Disk) and the like, there is a strong demand for a thin and low-cost optical pickup as a drive thereof. In response to such demands, optical pickups using hologram elements have been actively developed.

As a conventional example using a hologram element, there is an example proposed in Japanese Patent Application Laid-Open No. Hei 4-31828. FIG.
As shown in FIG. 1, a semiconductor laser 101 as a light source, a collimator lens 102, a diffraction grating 103, a hologram element 104, a quarter-wave plate 105, an objective lens 106, an optical disk 107 as an optical information recording medium, and a photo as a light receiving element It is composed of diodes 108a and 108b. The hologram element 104 functions as an optical path separating element for separating incident light from the semiconductor laser 101 and reflected light from the optical disk 107,
It also functions as a light condensing element for condensing light at 8a and 108b. Therefore, the reflected light from the optical disk 107 is diffracted by the hologram element 104 at a predetermined angle with respect to the incident optical axis and travels toward the photodiodes 108a and 108b.

[0004] In order to reduce the size and thickness of the optical pickup, there is a configuration in which a deflection mirror is provided between the objective lens and the hologram element to bend the optical path.

FIG. 21 shows, as an example, Japanese Patent Application Laid-Open No.
An example shown in US Pat. Optical disk 11
A laser unit 112 and a rising mirror 113
And an objective lens 114 are arranged. In the laser unit 112, a semiconductor laser 115 as a light source and a multi-segment light receiving sensor 116 are mounted, and an optical member 117 fixed to the light emitting portion has a diffraction grating 1 for generating three beams.
A diffraction grating 119 is formed to guide the reflected light from the optical disk 18 and the optical disk 111 to the multi-division light receiving sensor 116. Thus, a deflecting mirror (start-up mirror 113) is provided between the objective lens 114 and the hologram element (diffraction grating 119) so that the optical path is bent.

FIG. 22 shows another example as disclosed in Japanese Patent Application Laid-Open No. HEI 8-12424.
An example shown in Japanese Patent Publication No. 05-2005 is shown. A diffraction grating 123 that divides light from a light source 122 provided on a base 121 into three beams, a transmission hologram element 124 that transmits the light, and condenses the transmitted light on an optical information recording medium 125. And a light receiving element 128 that is provided closer to the light source 122 than the hologram element 124 and reflects the light from the optical information recording medium 125 by the hologram element 124 and the reflection mirror 127. Bottom, objective lens (condensing lens 126) and hologram element 124
A deflecting mirror 129 is provided between the first and second mirrors, and is configured to bend the optical path.

[0007]

In a normal optical pickup, a light source (semiconductor laser 101) is used as shown in FIG.
Lens 1 along the optical axis of the light beam emitted from
02, diffraction grating 103, hologram element 104, 1/4
Optical elements such as a wave plate 105 and an objective lens 106 are arranged. At this time, each of the optical elements 102 to 106 is positioned with respect to the optical axis of the light beam emitted from the light source (semiconductor laser 101).
Must be arranged with a high degree of accuracy so that the incident surface is vertical. Although the optical elements 102 to 106 are shown in a state floating in space in the drawing, a holding member for holding each of the optical elements 102 to 106 is necessary in an actual optical pickup, and the holding member and Each optical element 102-
106 must be arranged with high precision.

In order to dispose it with high accuracy, the mechanical accuracy between the holding member and the optical elements 102 to 106 is made extremely high, or an adjustment step is provided so that the arrangement accuracy is increased during manufacturing, so that the necessary accuracy is maintained. However, the cost is inevitably increased in any case, which is a factor that hinders cost reduction.

FIG. 21 and FIG.
As for the optical pickup in which the optical path is bent by providing the deflecting mirrors 113 and 129 as shown in (1), it is necessary to newly increase the number of optical elements such as the deflecting mirrors 113 and 129. As a result, the size of the optical pickup is larger than that shown in the figure, and the number of components of the optical pickup is increased. -It is considered that the intended purpose of thinning cannot be sufficiently fulfilled.

Accordingly, the present invention provides an optical element having a structure including a parallel plate-shaped hologram element for separating incident light and reflected light in an optical element, while eliminating the need for a holding member for each optical element and eliminating the need for each optical element. It is an object of the present invention to provide an optical pickup in which elements can be arranged with high precision, the whole can be reduced in size and thickness at low cost, and an optical disk device using the optical pickup.

In addition, the present invention provides an optical pickup which can increase the optical path length inside an optical element by utilizing internal reflection and can achieve a further reduction in size and thickness, and an optical disk device using this optical pickup. With the goal.

Another object of the present invention is to provide an optical pickup which can be made thinner and an optical disk device using this optical pickup.

In order to achieve the above object, the present invention provides an optical pickup capable of increasing the light use efficiency, improving the S / N of a detection signal, or suppressing the light source energy, and using the optical pickup. It is an object of the present invention to provide an optical disk device that has been used.

Further, in order to achieve the above object, the present invention enhances the performance of separating incident light and reflected light and increases the S
It is an object of the present invention to provide an optical pickup capable of improving / N or suppressing the energy of a light source and an optical disk device using the optical pickup.

Another object of the present invention is to provide an optical pickup which can have a simpler configuration for realizing the above object, and an optical disk apparatus using the optical pickup.

In order to achieve the above object, the present invention is very small and thin, is resistant to environmental fluctuations and aging, and is more reliable than integrating most or all of the optical elements constituting the optical pickup. It is an object of the present invention to provide an optical pickup having high performance and an optical disk device using the optical pickup.

[0017]

According to the first aspect of the present invention, there is provided an optical pickup having a plurality of parallel plate-shaped optical elements including a hologram element for separating incident light from a light source and reflected light from an optical information recording medium. An optical axis direction of a light receiving element for detecting a signal by reflected light from the optical information recording medium, comprising a laminated optical element which is laminated and integrated in a direction perpendicular to an optical axis of a light beam emitted from the light source. The arrangement reference plane is coincident with an end face of the laminated optical element on which a light source light beam is incident.

Therefore, in a laminated optical element in which a plurality of parallel plate-shaped optical elements including a hologram element are laminated, the position of each element in the optical axis direction can be fixed by bonding or sticking the surfaces of the optical elements to each other. Therefore, a separate member for holding the optical element is not required. In addition, each optical element having a parallel substrate shape originally has a high surface accuracy of the incident surface to function as the optical element, and its thickness accuracy and parallelism are generally very high. The elements are formed with a predetermined thickness, and if necessary, a parallel transparent substrate of a predetermined thickness is arranged adjacent to each optical element and laminated, and the position of the light flux of each optical element in the optical axis direction is determined. It is possible to arrange them with high precision. Further, by setting the laminated optical element such that the optical axis direction arrangement reference plane of the light receiving element is equal to the end face of the laminated optical element where the light source light beam enters, the light receiving element can be simply contacted or adhered to the laminated optical element. The position in the optical axis direction can also be determined with high accuracy. Therefore, a member for holding each optical element is not required, and position adjustment in the optical axis direction is not necessary, so that an optical pickup using a hologram element can be provided very simply and at low cost.

According to a second aspect of the present invention, in the optical pickup according to the first aspect, the laminated optical element is formed to be inclined and parallel to the lamination surface so as to make the incident light and the reflected light an even number of times. A first reflecting surface for internal reflection and a second reflecting surface
And a reflection surface.

Accordingly, the first reflection surface and the second reflection surface formed in parallel to the lamination surface are formed such that the light is internally reflected an even number of times, thereby increasing the optical path length inside the lamination optical element. Therefore, the thickness of the laminated optical element can be further reduced, and the entire optical pickup can be reduced in size and thickness. Since the first reflecting surface and the second reflecting surface are parallel, the incident light and the outgoing light are always kept parallel.

An optical pickup according to a third aspect of the present invention provides:
A plurality of parallel plate-shaped optical elements including a hologram element for separating incident light from a light source and reflected light from an optical information recording medium are stacked in a direction perpendicular to an optical axis of an objective lens with respect to the optical information recording medium. A first reflecting surface that is formed in parallel to the laminated surface at an angle to the laminated surface and internally reflects the incident light and the reflected light an odd number of times. A second reflecting surface, and at an angle to the laminating surface, formed parallel to a straight line intersecting the laminating surface with the first and second reflecting surfaces, and A third surface on which the emitted light and the reflected light enter and exit, and the position of the light receiving surface of the light receiving element that performs signal detection by the reflected light from the optical information recording medium coincides with the third surface; It is characterized by being.

Accordingly, the light source light beam enters from the third surface, and the light receiving surface of the light receiving element is arranged on the same surface.
Since it is not necessary to arrange components such as a light source and a light receiving element in a direction perpendicular to the optical information recording medium surface where the thickness of the optical pickup increases, it is possible to provide a thinner optical pickup.

According to a fourth aspect of the present invention, in the optical pickup according to the second or third aspect, the first reflection surface and the second reflection surface of the laminated optical element are treated with a reflection film. Features.

Therefore, since the surfaces are subjected to the reflection film treatment for the internal reflection on the first reflection surface and the second reflection surface,
Refractive index of optical element constituting laminated optical element, first and second
The degree of freedom of conditions such as the inclination angle of the reflection surface becomes large, and a highly flexible design can be realized.

According to a fifth aspect of the present invention, in the optical pickup according to the second or third aspect, a portion of the laminated optical element at which a light beam is reflected between the first reflection surface and the second reflection surface. Assuming that the refractive index of the optical element having the smallest refractive index among the constituent optical elements is N, the angle θ between the laminated surface and the first and second reflecting surfaces is sin θ>
The ratio is set to be 1 / N.

Therefore, by setting the angle θ between the laminated surface and the first and second reflection surfaces so as to satisfy sin θ> 1 / N, the first and second reflection surfaces can be subjected to the reflection film treatment. Even if it is not provided, it can be internally reflected by total reflection on the reflecting surface. Therefore, by setting sin θ> 1 / N, it is not necessary to apply a reflection film treatment to the first and second reflection surfaces, and a thinner optical pickup can be provided at a lower cost. Furthermore, since the internal reflection is total reflection, there is almost no loss of light and the light use efficiency is high, so that the amount of light incident on the light receiving element increases and the S / N of the detection signal improves. Also, the S / S
When N is set to the same level as the conventional one or when the light intensity reaching the recording surface of the optical information recording medium is set to the same level as the conventional one, the power of the light source can be reduced. Heat can be suppressed and energy can be saved.

[0027] The invention according to claim 6 is the invention according to claims 1 to 5.
In the optical pickup according to any one of the above, the parallel plate-shaped hologram element is a polarization hologram element, and a parallel plate-shaped quarter-wave plate is integrally provided on the optical information recording medium side of the polarization hologram element. It is characterized by the following.

Therefore, by using a polarization hologram element as a hologram element in the laminated optical element, the incident P-polarized light has no diffraction effect, and is transmitted through a quarter-wave plate twice to become S-polarized light. By imparting a diffraction effect to the reflected light from the optical information recording medium, it becomes possible to greatly improve the performance of separating incident light and reflected light (extinction ratio).
Since the incident light and the reflected light are separated in this manner, the light use efficiency is high, and as a result, the amount of light incident on the light receiving element increases, and the S / N of the detection signal is improved because the amount of flare light is small. Further, when the S / N of the detection signal is made approximately the same as that of the related art or when the light intensity reaching the recording surface of the optical information recording medium is made approximately the same as that of the related art, the power of the light source can be reduced. Heat of the light source generated simultaneously with light emission can be suppressed, and energy saving can be achieved.

[0029] The invention according to claim 7 is the invention according to claims 1 to 6.
In the optical pickup according to any one of the above, the laminated optical element is integrally provided with a collimating lens having a parallel substrate shape for converting divergent light from the light source into parallel light.

Therefore, by integrating the collimating lens, which had to be separately provided, as a parallel substrate-shaped element into the laminated optical element, a holding member for holding the collimating lens and a step of adjusting and arranging the holding member are provided. It becomes unnecessary, and a more simple and low-cost optical pickup can be provided.

According to an eighth aspect of the present invention, in the optical pickup according to the seventh aspect, the collimating lens having a parallel substrate shape is an anamorphic lens having a beam shaping function.

Therefore, by using an anamorphic lens having a function of isotropically shaping divergent light having a divergence angle different from the direction of the emitted optical axis depending on the direction and making it parallel light as a collimating lens, the optical axis can be bent. Since there is no parallel shift and it is very easy to handle as an optical element, the optical pickup according to claim 7 having a beam shaping function without bending of the optical axis or parallel shift can be easily realized.

[0033] The ninth aspect of the present invention provides the first to eighth aspects.
In the optical pickup according to any one of the above, an objective lens for irradiating the optical information recording medium with a light beam from the light source is provided separately from the laminated optical element.

Therefore, the objective lens, which is an essential optical element for the optical pickup, is provided separately from the laminated optical element such as a hologram element, so that the tracking / focusing which is usually performed on the objective lens is performed. The object driven by the actuation mechanism for servo control can be a single objective lens.

According to a tenth aspect of the present invention, in the optical pickup according to any one of the first to eighth aspects, the objective lens for irradiating the optical information recording medium with the light beam from the light source is a solid immersion having a parallel substrate shape. It is made of a lens and is integrated with the laminated optical element.

Therefore, by forming the objective lens as a solid immersion lens having a parallel substrate shape, the solid immersion lens has a very good affinity for being integrally formed with the laminated optical element because of the parallel substrate shape. The miniaturization is possible, and the laminated optical element can be extremely miniaturized. As a result, it is possible to integrate the components of the optical pickup including the light receiving element by incorporating the parallel substrate-shaped solid immersion lens, which is the objective lens, into the laminated optical element. Can be provided.

According to an eleventh aspect of the present invention, in the optical pickup according to the seventh, eighth or ninth aspect, the light source and the light receiving element are integrally formed on the same substrate as the light source and the light receiving element. A light receiving / emitting element is used, and the reference plane of the integrated light receiving / emitting element in the optical axis direction and the end face of the laminated optical element on which the light source light beam enters are coincident.

Therefore, since the integrated light receiving / emitting element in which the light source and the light receiving element are formed on the same base and the collimating lens for converting the divergent light into parallel light is integrated with the laminated optical element, The components of the optical pickup other than the lens are integrated in the laminated optical element, so that the optical pickup can be realized to be very small and thin. In addition, since these components are integrated, there is no displacement of the element due to environmental change or aging, and a highly reliable optical pickup can be realized.

The twelfth aspect of the present invention is the seventh aspect or the eighth aspect.
In the optical pickup according to the above, the objective lens for irradiating the optical information recording medium with the light flux from the light source is formed of a solid immersion lens having a parallel substrate shape, is integrated with the laminated optical element, and as the light source and the light receiving element,
These light sources and the light-receiving element are formed on the same base using an integrated light-emitting / receiving element, and an optical axis direction reference plane of the integrated light-receiving / emitting element and an end face of the laminated optical element on which a light source light beam enters. Are matched.

Accordingly, an integrated light receiving / emitting element in which a light source and a light receiving element are formed on the same base, and a collimating lens for converting divergent light and a lens for solid-state immersion lens are used as a laminated optical element. Since the optical pickup is integrated, all the components of the optical pickup including the objective lens are integrated with the laminated optical element, and it is possible to realize the optical pickup in a very small and thin shape. In addition, since these components are integrated, there is no displacement of the element due to environmental change or aging, and a highly reliable optical pickup can be realized. Further, actuation by tracking / focus servo can be performed on the optical pickup as the integrated laminated optical element, and an optical pickup with no optical axis shift due to actuation can be realized.

According to a thirteenth aspect of the present invention, there is provided an optical disk apparatus, comprising: a motor for rotating an optical information recording medium; and a light beam from the light source for the optical information recording medium, which is rotationally driven by the motor, to the objective lens. The optical pickup according to any one of claims 1 to 12, wherein the light is radiated through the optical information recording medium and the reflected light from the optical information recording medium is separated by the hologram element in the laminated optical element.

Therefore, since the optical pickup according to any one of the first to twelfth aspects is provided, it is possible to provide a low-cost optical disk apparatus in which the size of the optical pickup is reduced and the cost is reduced.

[0043]

FIG. 1 shows a first embodiment of the present invention.
A description will be given based on FIG. FIG. 1 shows a schematic configuration of an optical disk device using the optical pickup 1 of the present embodiment. The optical pickup 1 performs a recording or reproducing operation while being opposed to an optical information recording medium 3 which is rotationally driven by a motor 2 such as a spindle motor, and moves in a medium radial direction by a seek mechanism such as a seek motor 4. It is provided freely.

FIG. 2 shows a configuration example of the optical pickup 1 used in such an optical disk device. The optical pickup 1 is an example of an infinite optical pickup, and basically includes a light source (not shown) and a collimating lens (not shown).
And a diffraction grating 5 for generating three beams, a hologram element 6, an objective lens 7, and first and second light receiving elements 8a and 8b.

Thus, the collimated incident light 9 from the light source enters the diffraction grating 5 to generate three beams,
These three beams pass through the hologram element 6 and are focused and irradiated on the recording surface 3a of the optical information recording medium 3 by the objective lens 7. The reflected light from the optical information recording medium 3 follows a path opposite to the incident light and passes through the objective lens 7 and the hologram element 6. Here, the optical pickup 1 shown in FIG. 2 uses a differential beam size method for detecting a focus error signal, and the hologram element 6 separates the reflected light into two light beams at a predetermined angle (diffraction reflected light 10a, 10b). ) And is designed so that each of the separated diffracted reflected lights 10a and 10b is focused at a different distance, and the light receiving surfaces 11a and 11b of the first and second light receiving elements 8a and 8b, respectively.
And various signals corresponding to the light intensity are detected.

Here, the hologram element 6 is originally formed in a parallel plate shape in which a diffraction grating shape is formed, and a predetermined gap is formed between the hologram element 6 and the diffraction grating 5 similarly formed in a parallel plate shape. By interposing a parallel plate-shaped parallel transparent substrate 12 having a predetermined thickness to secure the optical path length, the hologram element 6, the parallel transparent substrate 12 and the diffraction grating 5 integrally form the laminated optical element 13. It is configured. The laminated optical element 13 is arranged and laminated so that the laminated surface of the optical elements 6, 12, 5 is perpendicular to the optical axis direction of the incident light 9 (the optical axis direction of the objective lens 7). In addition, the optical axis direction arrangement reference planes 14 of the light receiving elements 8a and 8b are set to coincide with the end face 13a of the laminated optical element 13 where the incident light 9 is incident. In the present embodiment, the convex lens-shaped objective lens 7 is driven by an actuation mechanism for tracking / focus servo, and is therefore separate from the laminated optical element 13.

In the case of the optical pickup 1 using the laminated optical element 13, the operation described above is performed in exactly the same manner.

According to the optical pickup 1 of the present embodiment, the following effects can be obtained. First, the laminated optical element 13 can fix the positions of the optical elements 6, 12, 5 in the optical axis direction by bonding or adhering the surfaces of the optical elements 6, 12, 5 separately. Optical element 6,1
A member for holding 2 and 5 is not required. In addition, since the optical element having a parallel substrate shape originally has a high surface accuracy of the incident surface to fulfill the function as the optical element, and its thickness accuracy and parallelism are also generally very high, each optical element 6, 12 and 5 are formed with a predetermined thickness, and if necessary, a parallel transparent substrate of a predetermined thickness is disposed adjacent to each optical element and laminated, and the optical axis of the luminous flux of each optical element is obtained. The position in the direction can be arranged with high accuracy. Also, the light receiving element 8
a, 8b in the optical axis direction reference plane 14 and the laminated optical element 13
By setting the laminated optical element 13 to be equal to the incident end face 13a of the light source light beam of the light source, the position in the optical axis direction can be raised simply by contacting or adhering the light receiving elements 8a and 8b to the end face 13a of the laminated optical element 13. It is possible to determine the accuracy.

Therefore, according to the present embodiment, there is no need for a member for holding each of the optical elements 6, 12, and 5, and there is no need for position adjustment in the optical axis direction. Therefore, a very simple and low-cost hologram element. 6 can be realized. Further, the objective lens 7 which is an essential optical element of the optical pickup 1 is provided separately from the laminated optical element 13 such as the hologram element 6 or the like, so that the tracking / focusing normally performed on the objective lens 7 is performed. The object to be driven by the actuation mechanism for servo control of the objective lens 7 can be a single object.
Such an optical pickup 1 can be used as an optical disc device.
By using the optical disc device, an optical disc device in which a portion of the optical pickup 1 is reduced in size and cost and which can perform high-speed seek drive at low cost can be obtained.

When the light receiving elements 8a and 8b are provided with the cover glass 15 and the light receiving surfaces 11a and 11b are set at the recessed positions, the thickness of the parallel transparent substrate 12 is made thinner as shown in FIG. The multilayer optical element 13 may be set so that the optical axis direction arrangement reference surface 14 of the light receiving elements 8a and 8b is equal to the incident end face 13a of the multilayer optical element 13 for the light source light beam.

The present invention is not limited to an infinite system optical pickup. For example, as shown in FIG. 4, a finite system light in which divergent light 17 from a light source 16 is directly condensed by an objective lens 7 is used. The same applies to the pickup 18. Further, a configuration in which the diffraction grating 5 for generating three beams is not provided, a configuration in which the hologram element is optimized by employing a knife edge method other than the differential beam size method, or an astigmatism method may be used.

The point is that optical elements other than the objective lens 7 including the hologram element 6 are formed in a parallel plate shape (they need not be strictly parallel plates), and are laminated perpendicular to the optical axis direction of the incident light 9. Thus, the stacked optical element 13 is configured so that the optical axis direction arrangement reference surface 14 of the light receiving elements 8a and 8b and the end face 13a of the stacked optical element 13 where the light source light beam enters are set to coincide. I just need.

A second embodiment of the present invention will be described with reference to FIG. The same portions as those described in the first embodiment are denoted by the same reference numerals, and description thereof is omitted (the same applies to each of the following embodiments).

In the optical pickup 21 of the present embodiment, the front surface and the back surface of the laminated optical element 13 in the optical pickup 1 are formed at a predetermined angle θ with respect to the laminated surface and at a predetermined thickness. By using cut surfaces cut in parallel, a laminated optical element having a first reflecting surface 22 and a second reflecting surface 23 and having a parallelogram cross section is used. Correspondingly, the objective lens 7 and the light receiving elements 8a and 8b and the light source side are arranged to be shifted in the front-rear direction. Specifically, the first transparent surface 22 and the second reflective surface 23 of the parallel transparent substrate 12 in the laminated optical element 13 have an optical element having an internal light reflected even number times, here, twice. Have been. These first and second
The reflection surfaces 22 and 23 are subjected to a reflection film treatment so as to reflect forward.

In such a configuration, the laminated optical element 1
The incident light 9 from the light source incident on 3 is internally reflected by the second reflecting surface 23, then further internally reflected by the first reflecting surface 22, and then internally reflected by the first and second reflecting surfaces 22 and 23. Being
The light enters the light receiving surfaces 11a and 11b of the light receiving elements 8a and 8b disposed at predetermined positions with respect to the laminated optical element 13. No.
Since the first and second reflecting surfaces 22 and 23 are parallel to each other,
When the number of times that the light beam incident on the laminated optical element 13 is reflected by the two inclined reflecting surfaces 22 and 23 is an even number,
The incident light and the reflected light are always parallel. In FIG. 5, the number of internal reflections is two, but the number of internal reflections may be four or six or an even number as described above.

According to the optical pickup 21 of the present embodiment, the light is internally reflected by the two inclined reflecting surfaces 22 and 23 an even number of times, and the optical path length can be increased inside the laminated optical element 13. The laminated optical element 13 (here, the parallel transparent substrate 12) can be made thinner than in the case of carrying out the embodiment, and the entire optical pickup 21 can be made smaller and thinner.

A third embodiment of the present invention will be described with reference to FIG. The optical pickup 26 of the present embodiment is different from the first reflection surface 22 in the optical pickup 21 described above with the second reflection surface 22.
A configuration in which a parallel transparent substrate 27 is further integrally added to the side of the diffraction grating 5 in addition to the laminated optical element 13 having the reflective surface 23, and a certain angle (here, a right angle here) with respect to the laminated surface
So that these laminated surfaces and the first and second reflecting surfaces 22,
A third surface 28 formed by cutting the parallel transparent substrate 27 so as to be parallel to the straight line intersecting with the third surface 28
Is provided. The third surface 28 is a surface through which the incident light 9 and the reflected lights 10a and 10b enter and exit, and the third surface 28 reflects the reflected light 10 from the optical information recording medium 3.
The positions of the light receiving surfaces 11a and 11b of the light receiving elements 8a and 8b that perform signal detection using the signals a and 10b are set so as to coincide with the third surface 28. That is, the light source and the light receiving element 8a,
8b is disposed not in the lamination direction of the laminated optical element 29 but in the depth direction in the layer direction. Here, in the present embodiment, the first and second reflecting surfaces 22 and 23 are set to internally reflect the odd number of times, here three times.

That is, the optical pickup 26 of the present embodiment
In the first embodiment, a light beam is made to enter from the third surface 28 in the layer direction, and the light beam is internally reflected three times by the first and second reflecting surfaces 22 and 23, and the reflected light from the optical information recording medium 3 is also reflected by the third surface. And a laminated optical element 29 for emitting the light from the surface 28 and entering the light receiving elements 8a and 8b. In the example shown in FIG. 6, the number of reflections on the first and second reflection surfaces 22 and 23 is three, but the number of internal reflections may be one or five or an odd number as described above.

According to the optical pickup 26 of the present embodiment, the third surface 2 formed in the layer direction of the laminated optical element 29
A light source light beam is incident on the light receiving element 8 and the light receiving elements 8a and 8b
The light receiving surfaces 11a and 11b are arranged so that the light source and the light receiving elements 8a and 8b are arranged in a direction (lamination direction) perpendicular to the surface of the optical information recording medium 3 where the thickness of the optical pickup 26 increases. There is no need to dispose elements, and a thinner optical pickup can be realized.

A fourth embodiment of the present invention will be described with reference to FIG. This embodiment is applied to the laminated optical element 13 or 29 having the first and second reflecting surfaces 22 and 23 as in the second or third embodiment. Here, an example of application to the laminated optical element 13 of the second embodiment will be described.

The angle between the lamination surface and the first and second reflection surfaces 22 and 23 is θ, and a member having the smallest refractive index (here, a parallel transparent member) among the members constituting the surface for internally reflecting the light beam. Assuming that the refractive index of the substrate 12) is N, the relationship between θ and N is si
When nθ> 1 / N is set, the incident light flux is totally reflected by the reflection surfaces 22 and 23 as shown in FIG. Make internal reflection. On the other hand, in the case of sin θ <1 / N, if there is no reflective film, as shown in FIG.

Therefore, in the present embodiment, by setting sinθ> 1 / N with respect to the laminated optical element 13, the first
There is no need to apply a reflection film treatment to the second reflection surfaces 22 and 23, and the low-cost and thin optical pickup 1 can be realized. Further, since the internal reflection is total reflection, there is almost no light loss and the light use efficiency is high, so that the amount of light incident on the light receiving elements 8a and 8b increases and the S of the detection signal increases.
/ N is improved. Conversely, if the S / N of the detection signal is made approximately the same as that of the related art, or if the light intensity reaching the recording surface 3a of the optical information recording medium 3 is made approximately the same as that of the related art, the power of the light source is reduced. Therefore, it is possible to suppress the heat of the light source generated at the same time as the light emission, and to realize the optical pickup 1 that can save energy.

A fifth embodiment of the present invention will be described with reference to FIG. In the above-described embodiment, the optical path is shown so that the hologram element 6 causes a diffraction effect only on the reflected light. However, actually, even when the incident light 9 passes through the hologram element 6, diffraction is performed. Then, the diffracted light (not shown) is generated on the optical information recording medium 3 side of the hologram element 6. This diffracted light is not used for optical information recording and reproduction, and a part of the diffracted light is used as flare light.
And often becomes a factor that lowers the S / N of the detection signal.

In this respect, the optical pickup 3 of the present embodiment
1, the laminated optical element 1 in the optical pickup 1 described above.
The hologram element 6 of FIG. 3 is replaced with a polarization hologram element 32 having a different diffraction effect depending on the polarization direction, and a laminated optical element 34 having a 波長 wavelength plate 33 integrally added to the medium side.

According to the present embodiment, the use of the polarization hologram element 32 has no diffractive effect on the incident P-polarized light, and is transmitted through the quarter-wave plate 33 twice to become S-polarized light. The light reflected from the optical information recording medium 3 can have a diffraction effect, and the performance of separating incident light and reflected light (extinction ratio) can be greatly improved.

Therefore, according to the present embodiment, since the incident light and the reflected light are separated, the light use efficiency is high, and as a result, the amount of light incident on the light receiving elements 8a and 8b increases, and the S / S of the detection signal increases. N is improved. Further, since there is little flare light, the S / N is improved in this respect as well. Conversely, when the S / N of the detection signal is made approximately the same as that of the related art, or when the light intensity reaching the recording surface 3a of the optical information recording medium 3 is made approximately the same as that of the related art, the power of the light source 16 is reduced. Since it can be reduced, the heat of the light source 16 generated simultaneously with the light emission can be suppressed, and the optical pickup 31 that can achieve energy saving can be realized.

FIG. 9 shows, as in the case of the second embodiment,
It is a modification showing a configuration example applied to a case where first and second reflection surfaces 22 and 23 are provided.

A sixth embodiment of the present invention will be described with reference to FIG. In the optical pickup 36 of the present embodiment, the laminated optical element 34 in the optical pickup 31 described above is used.
Between the diffraction grating 5 and the parallel transparent substrate 12 in FIG.
6 is a laminated optical element 3 having a parallel plate-shaped collimating lens 37 having a function of converting divergent light into parallel light.
8 is provided.

According to the present embodiment, since the collimating lens 37, which had to be separately provided, was integrally formed in the laminated optical element 38, the member for holding the collimating lens 37 and the adjusting arrangement thereof This eliminates the need for a step or the like, and makes it possible to realize a simpler and lower-cost optical pickup 36.

FIG. 11 shows the case where the first and second
It is a modified example showing a configuration example applied to a case where reflective surfaces 22 and 23 are provided.

A seventh embodiment of the present invention will be described with reference to FIG. This embodiment is applied to the laminated optical element 38 according to the sixth embodiment. That is, instead of the collimating lens 37, an anamorphic lens 39 as shown in FIG.

As shown in FIG. 12, the anamorphic lens 39 isotropically shapes divergent light having a divergence angle different from the direction of the diverging angle with respect to the emission optical axis emitted from the light source 16 like a semiconductor laser, and converts the divergent light into parallel light. This is an optical element having a beam shaping function. Therefore, unlike laser beam shaping using a prism, a major feature is that there is no bending or parallel shift of the optical axis, and there is a great advantage that it is very easy to handle as an optical element. Further, by forming the anamorphic lens 39 as shown in FIG. 12, it is possible to form a parallel substrate, and the laminated optical element 38 can be easily formed.

Therefore, according to the present embodiment, it is possible to easily realize the optical pickup 36 having a beam shaping function without bending the optical axis and without parallel shift.

An eighth embodiment of the present invention will be described with reference to FIG. In the optical pickup 41 of the present embodiment, a solid immersion lens 42 having a parallel substrate shape is provided as an objective lens instead of the objective lens 7, and 1 / １ ／ of the laminated optical element 38 in the optical pickup 36 described above.
The solid immersion lens 4 is provided on the outer surface of the four-wavelength plate 33.
2 is provided with a laminated optical element 43 in which the two are integrated.

As for the solid immersion lens 42 having a parallel substrate shape, for example, as described in JP-A-11-45455, a solid immersion lens having a parallel substrate shape can be manufactured simply, with high accuracy, and at low cost. And the laminated optical element 4
The affinity for forming 3 is very good. Further, the solid immersion lens 42 can be made very small, and the laminated optical element 43 can be made very small.
Therefore, by incorporating the solid immersion lens 42, which is the objective lens, into the laminated optical element 43, it is possible to integrate almost all the components of the optical pickup 41 including the light receiving elements 8a and 8b, and it is extremely compact. In addition, it is possible to realize a thin optical pickup 41.

FIG. 14 is a modified example showing a configuration example applied to the case where the first and second reflecting surfaces 22 and 23 are provided as in the second embodiment.

A ninth embodiment of the present invention will be described with reference to FIGS. In the optical pickup 46 of the present embodiment, the semiconductor laser 47 as the light source and the light receiving element 8
A light receiving / emitting element 49 as shown in FIG. 16 in which the light receiving surfaces 11a and 11b of a and 8b are integrally formed on one base 48 is used. It is integrated with a laminated optical element 38 having first and second reflecting surfaces 22 and 23 (however, the diffraction grating 5 is omitted here) by adhesion or close contact. Further, the objective lens 7 may be used as the objective lens, but here, a solid immersion lens 50 having a single structure separate from the laminated optical element 38 is used.

According to the present embodiment, the semiconductor laser 47
And the light receiving elements 8a and 8b are integrally formed as an integrated light receiving and emitting element 49, and the collimating lens 37 for converting the divergent light into parallel light is integrally formed and further integrated with the laminated optical element 38. Almost all the components of the optical pickup 46 except for the lens (solid immersion lens 50) are integrated, so that the optical pickup 46 can be made very small and thin. Further, since the optical pickup 46 is integrated as described above, there is no displacement of the element due to environmental change or aging, and the highly reliable optical pickup 46 can be realized.

FIG. 17 shows a configuration example applied to a case where the laminated optical element has the first and second reflection surfaces 22, 23 and the third surface 28 as in the third embodiment. This is a modification. The example of the laminated optical element 51 in the illustrated example is a configuration example including the anamorphic lens 39 as a collimating lens.

A tenth embodiment of the present invention will be described with reference to FIG. The optical pickup 46 according to the present embodiment uses the integrated light emitting and receiving element 49 as described above, and for example, the first and second optical pickups 41 in the optical pickup 41 as shown in FIG.
It is integrated with a laminated optical element 43 having the second reflecting surfaces 22 and 23 (however, the diffraction grating 5 is omitted here) by adhesion or close contact.

That is, the semiconductor laser 47, the light receiving element 8a,
8b, objective lens (solid immersion lens 42)
Are integrated, and the optical pickup 56 can be made very small and thin. In addition, since they are integrated, there is no displacement of the elements due to environmental changes and aging, and a highly reliable optical pickup 56 can be realized. Also, since the optical pickup 56 can be made very small, its weight can be made very light. Therefore, actuation by tracking / focus servo can be performed on the integrated optical pickup 56, and it is possible to realize an optical pickup 56 having no optical axis deviation due to actuation.

[0082]

According to the optical pickup of the first aspect of the present invention, a laminated optical element in which a plurality of parallel plate-shaped optical elements including a hologram element are laminated, the surfaces of the optical elements are adhered or adhered to each other. As a result, the position of each element in the optical axis direction can be fixed, so that a separate member for holding the optical element is unnecessary, and each optical element in the form of a parallel substrate is originally incident to perform its function as the optical element. Since the surface accuracy of the surface is high and the thickness accuracy and parallelism are also generally very high, each optical element is formed with a predetermined thickness, and if necessary, a parallel transparent substrate with a predetermined thickness By simply arranging and stacking adjacent to each optical element, the position of the light beam in each optical element in the optical axis direction can be arranged with high accuracy, and the light receiving element can be stacked with the optical axis direction reference plane. The end face of the optical element where the light source beam enters is equal By setting the laminated optical element so that the optical element is positioned, it is possible to determine the position in the optical axis direction with high accuracy only by contacting or adhering the light receiving element to the laminated optical element, thereby holding each optical element. There is no need for
Since it is not necessary to adjust the position in the optical axis direction, an optical pickup using a hologram element can be provided very simply and at low cost.

According to the second aspect of the present invention, in the optical pickup according to the first aspect, the first reflection surface and the second reflection surface formed in parallel to the lamination surface by inclining with respect to the lamination surface have an even number of times. Since the internal reflection is employed, and the optical path length can be increased inside the multilayer optical element, the multilayer optical element can be further thinned, and the entire optical pickup can be reduced in size and thickness.

According to the optical pickup of the third aspect of the invention, it is the same as the second aspect of the invention, but further includes the third aspect.
A light source luminous flux is incident from the surface of the optical pickup, and the light receiving surface of the light receiving element is arranged on the same surface, and the components such as the light source and the light receiving element are perpendicular to the optical information recording medium surface where the thickness of the optical pickup increases. Since it is not necessary to provide the optical pickup, it is possible to provide a thinner optical pickup.

According to the fourth aspect of the present invention, in the optical pickup according to the second or third aspect, when the internal reflection is performed on the first reflection surface and the second reflection surface, the surface is treated with a reflection film. Therefore, the degree of freedom of conditions such as the refractive index of the optical element constituting the laminated optical element and the inclination angles of the first and second reflecting surfaces is increased, and a highly flexible design can be realized.

According to the fifth aspect of the present invention, in the optical pickup according to the second or third aspect, a portion of the laminated optical element where the light beam is reflected is formed between the first reflection surface and the second reflection surface. Assuming that the refractive index of the optical element having the smallest refractive index among the optical elements is N,
Since the angle θ formed with the second reflecting surface is set so as to satisfy sin θ> 1 / N, even if the first and second reflecting surfaces are not subjected to the reflecting film treatment, the inner surfaces are formed by total reflection on the reflecting surfaces. The light can be reflected, so that there is no need to perform a reflection film treatment on the first and second reflection surfaces, and a thinner optical pickup can be provided at lower cost. Further, since the internal reflection is total reflection, there is almost no loss of light and the light use efficiency is increased, so that the amount of light incident on the light receiving element increases and the S / N of the detection signal can be improved. Alternatively, if the S / N of the detection signal is made approximately the same as before, or if the light intensity reaching the recording surface of the optical information recording medium is made approximately the same as before, the power of the light source can be reduced. Heat of the light source generated at the same time as light emission can be suppressed, and energy can be saved.

According to the sixth aspect of the present invention, in the optical pickup according to any one of the first to fifth aspects, a polarization hologram element is used as a hologram element in the laminated optical element, so that the incident P-polarized light is reduced. Without having a diffraction effect, the reflection light from the optical information recording medium, which has been transmitted twice through the quarter-wave plate and turned into S-polarized light, has a diffraction effect, so that the incident light and the reflected light can be reflected. Since the separation performance (extinction ratio) can be greatly increased, the light use efficiency is high,
As a result, the amount of light incident on the light receiving element is increased, and the flare light is small, so that the S / N of the detection signal can be improved. Alternatively, if the S / N of the detection signal is made approximately the same as before, or if the light intensity reaching the recording surface of the optical information recording medium is made approximately the same as before, the power of the light source can be reduced. Heat of the light source generated at the same time as light emission can be suppressed, and energy can be saved.

According to a seventh aspect of the present invention, in the optical pickup according to any one of the first to sixth aspects, the collimating lens, which had to be separately provided, is a laminated optical element having a parallel substrate shape. Since they are integrated inside, a holding member for holding the collimating lens and a step of adjusting and arranging the holding member are not required, and a more simple and low-cost optical pickup can be provided.

According to the eighth aspect of the present invention, in the optical pickup according to the seventh aspect, the function of isotropically shaping the divergent light having a divergence angle different from the direction of the emission optical axis depending on the direction and making the divergent light parallel. 8. A beam shaping function without bending or parallel shift of the optical axis because the use of an anamorphic lens having the above as the collimating lens makes it very easy to handle as an optical element without bending or parallel shift of the optical axis. Optical pickup can be easily realized.

According to the ninth aspect of the present invention, in the optical pickup according to any one of the first to eighth aspects, the objective lens which is an essential optical element for the optical pickup is a laminated optical element such as a hologram element. By separately providing the objective lens, the object driven by the actuation mechanism for servo control for tracking / focusing usually performed on the objective lens can be a single objective lens.

According to the tenth aspect of the present invention, the first aspect is provided.
The optical pickup according to any one of Items 1 to 8,
By forming the objective lens as a solid immersion lens in the shape of a parallel substrate, it has a very good affinity for being integrally formed with the laminated optical element because of the parallel substrate shape, and the solid immersion lens can be extremely miniaturized. Yes, the laminated optical element can be made very small, and as a result, almost all the components of the optical pickup including the light receiving element are integrated by incorporating the parallel substrate-shaped solid immersion lens, which is the objective lens, into the laminated optical element. It is possible to provide a very small and thin optical pickup.

According to the eleventh aspect of the present invention, in the optical pickup according to the seventh, eighth or ninth aspect, the light source and the light receiving element use an integrated light receiving and emitting element formed on the same base, and diverge. Since the collimating lens that converts light into parallel light is integrated into the laminated optical element, almost all components of the optical pickup except the objective lens are integrated into the laminated optical element, making the optical pickup extremely compact and compact. It is possible to realize a thin optical pickup, and since these components are integrated, there is no displacement of the element due to environmental change and aging, and a highly reliable optical pickup can be realized.

According to the twelfth aspect, the seventh aspect is provided.
Or the optical pickup according to 8, wherein the light source and the light receiving element use an integrated light receiving and emitting element formed on the same base,
In addition, since the collimating lens that converts the divergent light into parallel light and the anti-French lens using a solid immersion lens are integrated into the multilayer optical element, all the components of the optical pickup including the objective lens are integrated into the multilayer optical element. This makes it possible to realize an optical pickup that is extremely small and thin, and because these components are integrated, there is no displacement of the element due to environmental fluctuations and aging, and reliability is improved. A high optical pickup can be realized, and actuation by tracking / focus servo can be performed on the optical pickup that is an integrated laminated optical element.
It is possible to realize an optical pickup with no optical axis deviation due to actuation.

According to a thirteenth aspect of the present invention, since the optical pickup according to any one of the first to twelfth aspects is provided, an optical pickup device having a small and low-cost optical pickup portion is provided. Can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an optical disk device showing a first embodiment of the present invention.

FIG. 2 is a front view showing an optical pickup configuration.

FIG. 3 is a front view illustrating a configuration of an optical pickup according to a modified example.

FIG. 4 is a front view showing an optical pickup configuration of another modification.

5A and 5B show an optical pickup configuration according to a second embodiment of the present invention, wherein FIG. 5A is a front view and FIG. 5B is a side view.

6A and 6B show an optical pickup configuration according to a third embodiment of the present invention, wherein FIG. 6A is a front view and FIG. 6B is a side view.

FIGS. 7A and 7B show a configuration of a laminated optical element according to a fourth embodiment of the present invention. FIG. 7A is a side view of a comparative example, and FIG. 7B is a side view of the present embodiment.

FIG. 8 is a front view showing the configuration of an optical pickup according to a fifth embodiment of the present invention.

FIG. 9 is a side view showing a configuration of an optical pickup according to a modified example.

FIG. 10 is a front view showing the configuration of an optical pickup according to a sixth embodiment of the present invention.

FIG. 11 shows a configuration of an optical pickup according to a modified example thereof;
(A) is a front view, (b) is a side view.

FIGS. 12A and 12B show an anamorphic lens configuration according to a seventh embodiment of the present invention, wherein FIG. 12A is a front view and FIG. 12B is a side view.

FIG. 13 is a front view showing the configuration of an optical pickup according to an eighth embodiment of the present invention.

FIG. 14 shows an optical pickup configuration of a modified example thereof,
(A) is a front view, (b) is a side view.

FIGS. 15A and 15B show the configuration of an optical pickup according to a ninth embodiment of the present invention, wherein FIG. 15A is a front view and FIG. 15B is a side view.

FIG. 16 shows the structure of the integrated light emitting and receiving element, and FIG.
Is a front view, and (b) is a vertical side view.

FIG. 17 shows a configuration of an optical pickup according to the modification;
(A) is a front view, (b) is a side view.

FIGS. 18A and 18B show the configuration of an optical pickup according to a tenth embodiment of the present invention, wherein FIG. 18A is a front view and FIG. 18B is a side view.

FIG. 19 shows an optical pickup configuration of a modified example thereof;
(A) is a front view, (b) is a side view.

FIG. 20 is a front view showing an example of a conventional optical pickup.

FIG. 21 is a side view showing another example of the conventional optical pickup.

FIG. 22 is a side view showing still another example of the conventional optical pickup.

[Explanation of symbols]

 Reference Signs List 1 optical pickup 2 motor 3 optical information recording medium 5 optical element 6 hologram element 7 objective lens 8a, 8b light receiving element 9 incident light 12 optical element 13 laminated optical element 13a incident end face 14 optical axis direction reference plane 16 light source 18 optical pickup 21 light Pickup 22 First reflection surface 23 Second reflection surface 27 Optical element 28 Third surface 29 Multilayer optical element 31 Optical pickup 32 Polarization hologram element 33 Quarter wave plate 34 Multilayer optical element 36 Optical pickup 37 Collimating lens 38 Multilayer Optical element 39 Collimating lens, anamorphic lens 41 Optical pickup 42 Objective lens, solid immersion lens 43 Multilayer optical element 46 Optical pickup 47 Light source 48 Base 49 Integrated light emitting and receiving element 50 Objective lens 51 Multilayer optical element 56 Optical pin Up

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 7/22 G02B 7/18 A F term (Reference) 2H043 BA00 2H049 CA07 CA09 CA11 CA15 5D119 AA04 AA11 AA22 AA38 AA43 BA01 CA06 DA01 DA05 EC27 FA05 JA14 JA17 JA44 JA57 JA64 JB03 JC03 JC05 JC07 KA02 NA05

Claims (13)

[Claims] A plurality of parallel plate-shaped optical elements including a hologram element for separating incident light from a light source and reflected light from an optical information recording medium are perpendicular to an optical axis of a light beam emitted from the light source. An optical axis direction reference plane of a light receiving element for detecting a signal by reflected light from the optical information recording medium, and an end face on which a light source light beam of the laminated optical element is incident. An optical pickup characterized in that: A first reflecting surface and a second reflecting surface which are formed in parallel to the laminated surface so as to be inclined with respect to the laminated surface and internally reflect the incident light and the reflected light an even number of times; 2. The optical pickup according to claim 1, comprising: 3. A plurality of parallel plate-shaped optical elements including a hologram element for separating incident light from a light source and reflected light from an optical information recording medium with respect to an optical axis of an objective lens with respect to the optical information recording medium. A laminated optical element that is vertically laminated and integrated, and the laminated optical element is formed to be inclined and parallel to the lamination surface thereof and internally reflect the incident light and the reflected light an odd number of times. 1st reflective surface and 2nd
Having a certain angle with respect to the lamination surface and formed parallel to a straight line intersecting the lamination surface and the first and second reflection surfaces, and A third surface through which the reflected light enters and exits, and a position of a light receiving surface of a light receiving element that performs signal detection by the reflected light from the optical information recording medium coincides with the third surface. An optical pickup characterized by the following. 4. The optical pickup according to claim 2, wherein the first reflection surface and the second reflection surface of the laminated optical element are subjected to a reflection film treatment. 5. An optical element having the smallest refractive index among optical elements constituting a portion where a light beam is reflected among the first reflection surface and the second reflection surface in the laminated optical element. Assuming that the refractive index is N, the laminated surface and the first,
4. The optical pickup according to claim 2, wherein an angle [theta] with respect to the second reflecting surface is set so that sin [theta]> 1 / N. 6. The parallel hologram element according to claim 1, wherein the parallel hologram element is a polarization hologram element, and a parallel plate １ ／ wavelength plate is integrally provided on the polarization information hologram element side of the optical information recording medium. Item 6. The optical pickup according to any one of Items 1 to 5. 7. The laminated optical element according to claim 1, further comprising a parallel substrate-shaped collimating lens for converting divergent light from the light source into parallel light.
The optical pickup according to any one of the above. 8. An optical pickup according to claim 7, wherein said collimating lens having a parallel substrate shape is an anamorphic lens having a beam shaping function. 9. The optical system according to claim 1, wherein an objective lens for irradiating the optical information recording medium with a light beam from the light source is provided separately from the laminated optical element. Optical pickup as described. 10. An objective lens for irradiating the optical information recording medium with a light beam from the light source is a parallel substrate-shaped solid immersion lens, and is integrated with the laminated optical element. 8. The optical pickup according to any one of 8. 11. An integrated light receiving / emitting element in which the light source and the light receiving element are formed on the same base as the light source and the light receiving element, and a reference plane in the optical axis direction of the integrated light receiving / emitting element. 10. The optical pickup according to claim 7, wherein an end face of the laminated optical element on which a light source light beam is incident coincides. 12. An objective lens for irradiating the optical information recording medium with a light beam from the light source is formed of a solid immersion lens having a parallel substrate shape, is integrated with the laminated optical element, and serves as the light source and the light receiving element. An integrated light receiving and emitting element in which the light source and the light receiving element are formed on the same base is used, and the reference surface of the integrated light receiving and emitting element in the optical axis direction and the end face of the laminated optical element on which the light source light flux enters are one. The optical pickup according to claim 7 or 8, wherein 13. A motor for rotating and driving the optical information recording medium, and a light beam from the light source is applied to the optical information recording medium rotationally driven by the motor via the objective lens. 2. The reflected light from the optical element is separated by the hologram element in the laminated optical element.
13. An optical disc device comprising: the optical pickup according to any one of claims 12 to 12.