WO2011158413A1

WO2011158413A1 - Optical head, optical element and data recording device

Info

Publication number: WO2011158413A1
Application number: PCT/JP2011/002089
Authority: WO
Inventors: 新藤　博之
Original assignee: コニカミノルタオプト株式会社
Priority date: 2010-06-16
Filing date: 2011-04-08
Publication date: 2011-12-22
Also published as: JP2013175247A

Abstract

Provided is an optical head that is easy to handle and can be made thin. An optical head (4) has a slider (60), a frame structure (40) and a laser diode (LD) (50). The structure (40) is substantially the same size as the slider (60) and is provided on the slider (60). The LD (50) is provided on the slider (60) at a position to the inside of a frame (41) of the structure (40). On part of the frame (41), the structure (40) has a prism (43) that guides light emitted from the LD (50) to the slider (60). The slider (60) irradiates the light guided by the prism (43) onto the recording medium.

Description

Optical head, optical element, and information recording apparatus

The present invention relates to an optical head, an optical element, and an information recording apparatus.

Magnetic recording devices such as hard disk devices are becoming smaller and larger in capacity, and magnetic heads are also becoming smaller. Accordingly, the slider of the magnetic head is also downsized. For example, a slider called a femto slider has a length of 0.85 mm, a width of 0.7 mm, and a thickness of 0.23 mm.

Also, an optically assisted magnetic recording method has been proposed to further increase the recording density. An optical waveguide for irradiating a recording medium with light from a light source is formed on a slider of this type of magnetic head. As a slider, there is a type having an optical component that guides light emitted from a light source to an optical waveguide. Since the magnetic head of the optically assisted magnetic recording system is small, an optical component provided on the slider of the magnetic head is also required to have a size of several tens to several hundreds of μm.

For example, in the thin film magnetic head disclosed in Patent Document 1, a unit substrate on which a light source is mounted is mounted on a slider. The light emitted from the light source is guided to the light propagation part of the slider by a prism provided at the tip of the unit substrate.

Further, in Patent Document 2, as a technique for realizing high yield mounting by active alignment, first, a chip-on-carrier structure in which a semiconductor laser diode (LD) is mounted on a submount is fabricated in an intermediate manner. Discloses a method of manufacturing a magnetic head in which a submount on which an LD is mounted is mounted on a slider. In Embodiments 1 and 2 of Patent Document 2, the micromirror formed on the emission end face of the edge-emitting LD element and the microlens mechanism formed on the submount function as optical components. Thereby, the light emitted from the LD is guided to the slider. In Embodiment 3 of Patent Document 2, a reflection mirror that is one independent component fixed to a groove formed in a submount and a lens structure integrated in the reflection mirror function as an optical component. . Thereby, the light emitted from the edge-emitting LD is deflected by the reflection mirror and guided to the slider.

JP 2007-335027 A JP 2009-4030 A

As described above, when an optical component is provided on the slider, since the optical component is very small, it becomes a problem how to manufacture the optical component. In addition, since a minute optical component is difficult to handle, there is a problem of how to handle the optical component and attach it to the slider.

For example, since the unit substrate described in Patent Document 1 is almost the same size as the slider, it is easier to handle than the prism alone. However, it is difficult to manufacture a unit substrate provided with a prism, which requires many steps. Here, the manufacturing method of the unit board | substrate described in patent document 1 is demonstrated. First, a dielectric film (prism base material) serving as a propagation layer is laminated on a wafer-shaped substrate serving as a unit substrate, and the wafer-shaped substrate is cut into a rod-shaped member. And the reflective surface of a prism is formed by grind | polishing the edge of the dielectric material film in a rod-shaped member. However, it is very difficult to polish a prism having a size of several tens of μm. Moreover, since it is necessary to adjust the angle and control the polishing amount during polishing, a large number of man-hours are required. Further, since the prism is formed by being laminated on a wafer-like substrate, the prism may be peeled off during polishing, and as a result, the yield of the unit substrate is lowered.

In Embodiments 1 and 2 of Patent Document 2, the optical axis of the lens structure is arranged in parallel to the thickness direction of the magnetic head. For this reason, if it is going to secure the distance from a light emission point to the vertex of a lens surface, a magnetic head will become thick. In order to shorten this distance, the focal length may be shortened, but the radius of curvature of the lens surface becomes small and aberration occurs, resulting in a decrease in optical coupling efficiency with the optical waveguide.

Furthermore, in Embodiment 3 of Patent Document 2, it is necessary to fix the reflecting mirror in the groove formed in the submount. Since the size of the reflecting mirror is as small as 100 μm to 200 μm, handling is difficult. In addition, it is not easy to fix the reflection mirror in the groove while aligning the optical axes of the LD and the reflection mirror, and many man-hours are required. Furthermore, when an adhesive for fixing the reflecting mirror is applied between the reflecting mirror and the submount, the adhesive may enter the beam passage region and the reflecting mirror may not function as an optical component.

In both Patent Documents 1 and 2, a unit substrate and a submount are arranged between the light source and the slider. Therefore, the magnetic head becomes thick, and as a result, the magnetic recording device becomes thick.

The present invention solves the above-described problems, and an object thereof is to provide an optical head that is easy to handle and can be thinned, an optical element used in the optical head, and an information recording apparatus having the optical head. There is to do.

The invention described in claim 1 is an optical head having a light source, a slider, and a frame-like structure. The slider floats on the recording medium and irradiates the recording medium with light from the light source. The structure has substantially the same size as the slider and is provided on the slider. The light source is provided on the slider and inside the frame of the structure. The structure has an optical function part that guides light emitted from the light source to the slider in a part of the frame.
According to a second aspect of the present invention, in the optical head according to the first aspect, the optical function part is formed integrally with the structure.
According to a third aspect of the present invention, in the optical head according to the first or second aspect, the optical function unit is constituted by a prism having an incident surface and a deflection surface. The incident surface allows light emitted from the light source to enter the inside. The deflecting surface deflects the light incident inside by the incident surface and guides it to the slider.
The invention according to claim 4 is the optical head according to claim 3, wherein the deflecting surface of the prism has an aspherical shape, a spherical shape, a cylindrical surface shape or an elliptic cylindrical surface shape, The light is condensed and guided to the slider.
The invention according to claim 5 is the optical head according to claim 3, wherein the light source is constituted by a semiconductor laser diode. The semiconductor laser diode is provided on the slider with its substrate side facing the slider. The prism further has an exit surface that emits the light deflected by the deflecting surface to the outside of the prism. The deflecting surface or the emitting surface has an aspherical shape, a spherical shape, a cylindrical surface shape, or an elliptic cylindrical surface shape, and collects light from the light source and guides it to the slider.
According to a sixth aspect of the present invention, there is provided the optical head according to the first or second aspect, wherein the optical function unit is configured by a reflecting surface that reflects the light emitted from the light source and guides it to the slider. Yes.
The invention according to claim 7 is an optical element having a frame and an optical function part. The optical function unit is provided in a part of the frame, and is configured to receive light from the inside of the frame and guide the light to the outside of the frame.
The invention according to claim 8 is the optical element according to claim 7, wherein the frame and the optical function part are integrally formed.
According to a ninth aspect of the present invention, in the optical element according to the seventh or eighth aspect, the optical function unit is constituted by a prism having an incident surface and a deflection surface. The incident surface receives light from the inside of the frame and enters the inside. The deflecting surface deflects the light incident inside by the incident surface and guides it to the outside of the frame.
According to a tenth aspect of the present invention, in the optical element according to the ninth aspect, the deflecting surface of the prism has an aspherical shape, a spherical shape, a cylindrical surface shape, or an elliptic cylindrical surface shape.
The invention according to claim 11 is the optical element according to claim 7 or claim 8, wherein the optical function unit receives light from the inside of the frame and reflects the light to the outside of the frame. It is comprised by the reflective surface.
The invention according to claim 12 includes a recording medium and the optical head according to any one of claims 1 to 6, and the recording medium is irradiated with light emitted from a light source by a slider. An information recording device configured to record information.

According to the present invention, since the structure including the optical function part has almost the same size as the slider, handling becomes easy. Thereby, the structure including the optical function part can be easily attached to the slider. In addition, since the structure has a frame shape, the light head is thinned by arranging the light source inside the frame, even when the light source and the optical component are provided on the slider. It becomes possible.

In addition, by integrally forming the structure that is a frame and the optical function part, a process such as polishing for forming the optical function part becomes unnecessary. As a result, a structure having an optical function part can be easily manufactured.

It is a perspective view which shows schematic structure of an information recording device. 1 is an exploded perspective view of an optical head according to a first embodiment of the present invention. 1 is a perspective view of an optical head according to a first embodiment of the present invention. FIG. 4 is a cross-sectional view of the optical head according to the first embodiment of the present invention, and is a cross-sectional view of the optical head shown in FIG. 3 taken along the line IV-IV. 1 is a side view of an optical head according to a first embodiment of the present invention. 1 is a front view of an optical head according to a first embodiment of the present invention. It is a perspective view of the optical function part which concerns on a modification. It is a partial sectional view of an optical head concerning a modification. It is a perspective view of the optical function part which concerns on another modification. It is sectional drawing of the optical head which concerns on 2nd Embodiment of this invention. It is sectional drawing of the optical head which concerns on 3rd Embodiment of this invention.

(Schematic configuration of information recording device)
FIG. 1 shows a schematic configuration of an optically assisted magnetic recording device (for example, a hard disk device, hereinafter also referred to as “information recording device”) equipped with an optically assisted magnetic recording head. The information recording apparatus 1 includes, for example, a plurality of rotatable recording disks (magnetic recording media) 3, a head support 5, a tracking actuator 7, and an optically assisted magnetic head 4 (hereinafter “optical head 4”). And a driving device (not shown) in the housing 2. The disk 3 may be one. The head support portion 5 is provided to be rotatable in the direction of arrow A (tracking direction) with the support shaft 6 as a fulcrum. The tracking actuator 7 is attached to the head support portion 5. The optical head 4 is attached to the tip of the head support 5. A drive device (not shown) rotates the disk 3 in the direction of arrow B. The information recording apparatus 1 is configured to be able to move relative to the disk 3 while the optical head 4 floats on the disk 3.

[First Embodiment]
The optical head 4 according to the first embodiment will be described with reference to FIGS. FIG. 2 is an exploded perspective view of the optical head 4. FIG. 3 is a perspective view of the optical head 4. 4 is a cross-sectional view of the optical head 4 shown in FIG. 3 taken along the line IV-IV.

The optical head 4 is an optical head that records information on the disk 3 using light. The optical head 4 includes a structure 40, a semiconductor laser diode 50 (hereinafter referred to as “LD50”), and a slider 60. The structure 40 and the LD 50 are provided on the upper surface 60 a of the slider 60.

(Structure 40)
The structure 40 defines the position of the LD 50 and the position of the optical waveguide 64 provided on the slider 60, and guides the light emitted from the LD 50 to the optical waveguide 64. The structure 40 includes a rectangular frame 41, for example. A rectangular opening 42 is formed on the inner side surrounded by the frame body 41. A part of the frame body 41 is provided with a prism 43 having a triangular cross-sectional shape. The prism 43 corresponds to an example of an optical function unit. The structure 40 including the frame body 41 and the prism 43 corresponds to an example of an optical element. The size of the outer shape of the structure 40 is substantially the same as that of the slider 60. Further, the size of the opening 42 is larger than that of the LD 50. The size of the outer shape of the structure 40 is, for example, a thickness of about 100 μm, a length of 300 μm to 600 μm, and a width of 200 μm to 300 μm.

The prism 43 has an entrance surface 43a, a deflection surface 43b, and an exit surface 43c. The prism 43 guides the light emitted from the LD 50 to the optical waveguide 64 of the slider 60. As an example, the entrance surface 43a and the exit surface 43c are orthogonal to each other. Furthermore, the deflection surface 43b is inclined with respect to each of the incident surface 43a and the emission surface 43c. The incident surface 43 a faces the inside of the frame body 41. The incident surface 43 a receives light from the inside of the frame body 41 and makes the light enter the prism 43. The deflection surface 43b reflects the light incident inside by the incident surface 43a toward the output surface 43c. The exit surface 43 c is provided to face the entrance surface 64 a of the optical waveguide 64 of the slider 60. The light deflected by the deflecting surface 43b exits from the exit surface 43c and enters the entrance surface 64a. In this embodiment, for example, the surface of the frame 41 that faces the slider 60 and the emission surface 43c of the prism 43 are on the same plane. The refractive index of the prism 43 is larger than 1, for example, 1.5 to 1.6. The length of the prism 43 in the height direction is, for example, several tens μm to several hundreds μm.

Further, a reflective film may be provided on the deflection surface 43 b of the prism 43. As the reflective film, a metal thin film such as aluminum or gold or a dielectric multilayer film can be used. The reflective film is formed on the deflection surface 43b by, for example, vapor deposition or sputtering.

The structure 40 is made of, for example, an optically transparent resin or glass. The structure 40 is produced by, for example, injection molding, a glass mold method, or an imprint method. Examples of the resin for injection molding include thermoplastic resins such as polycarbonate (for example, AD5503, Teijin Chemicals Limited) and ZEONEX 480R (Nippon Zeon Corporation). An example of the resin for imprinting is PAK-02 (Toyo Gosei Co., Ltd.), which is a photocurable resin.

Further, it is preferable that the frame body 41 and the prism 43 are integrally formed. Accordingly, a process such as polishing for forming the prism 43 becomes unnecessary, and the number of steps for manufacturing the structure 40 can be reduced. In addition, since a process such as polishing is not necessary, the yield of the structures 40 is improved.

Further, in the mold used for manufacturing the structure 40, it is preferable that the surfaces corresponding to the incident surface 43a, the deflection surface 43b, and the emission surface 43c of the prism 43 are finished in a mirror state in advance. Thereby, a mirror surface can be obtained without polishing each surface of the prism 43 after molding.

(Semiconductor laser diode (LD) 50)
The LD 50 as a light source is disposed on the upper surface 60 a of the slider 60 and on the inner side (opening 42) of the frame body 41 of the structure 40. As shown in FIG. 4, in the LD 50, a lower clad layer and an upper clad layer (not shown) are formed on a substrate 51, and an active layer 52 is formed between the lower clad layer and the upper clad layer. Yes. In addition, electrode layers (not shown) are formed on both surfaces of the LD 50. The light exit surface from the LD 50 faces the entrance surface 43 a of the prism 43. Further, the surface opposite to the substrate 51 (surface close to the active layer 52) faces the upper surface 60 a of the slider 60.

As a material constituting the LD 50, for example, any one of materials such as GaAs, AlGaAs, InGaAs, AlGaInP, InAlGaN, InGaN, GaN, GaInNA, GaNAsP, and AlGaNAs may be used. The LD 50 can be manufactured by laminating layers necessary for light emission on a wafer.

(Slider 60)
A magnetic head portion 63 is provided at the tip of the slider 60. The magnetic head unit 63 includes an optical waveguide 64, a magnetic recording unit (not shown), and a magnetic information reproducing unit (not shown). The optical waveguide 64 guides the light guided by the prism 43 and emits it toward the disk 3. As shown in FIG. 2, the incident surface 64 a of the optical waveguide 64 is provided on the upper surface 60 a of the slider 60. Further, the exit surface 64b of the optical waveguide 64 is provided on the surface opposite to the upper surface 60a (the surface facing the disk 3). The emission surface 64b is provided with a plasmon probe (not shown) as a near-field light generating element. The light deflected by the prism 43 enters the optical waveguide 64 from the incident surface 64a and travels through the optical waveguide 64 toward the output surface 64b. The plasmon probe provided on the emission surface 64 b converts the light guided by the prism 43 into near-field light and emits it toward the disk 3. In addition, a magnetic recording unit (not shown) writes magnetic information to the recording portion of the disk 3. A magnetic information reproducing unit (not shown) reads magnetic information recorded on the disk 3.

As shown in FIG. 2, an electrode 61 and an electrode 62 are formed on the upper surface 60 a of the slider 60. The electrode 61 and the electrode 62 each have a predetermined pattern shape, and are connected to the LD 50 to supply driving power to the LD 50. The first terminal 61 a of the electrode 61 is formed on the upper surface 60 a of the slider 60. The second terminal 61 b is formed on the side surface of the slider 60. Further, the first terminal 62 a of the electrode 62 is formed on the upper surface 60 a of the slider 60. The second terminal 62 b is formed on the side surface of the slider 60. For example, by masking a region other than the electrode pattern on the upper surface 60a of the slider 60 and performing sputtering or the like using copper foil plating or a metal such as copper as a target material, the electrode 61 and the electrode 62 are formed on the upper surface 60a of the slider 60. It is formed. Alternatively, as the electrode 61 and the electrode 62, flexible wiring in which predetermined wiring is patterned may be fixed to the upper surface 60a of the slider 60.

An electrode layer (not shown) is formed on the substrate 51 side of the LD 50. This electrode layer is connected to the terminal 62a by a bonding wire 55 (see FIG. 4). An electrode layer is also formed on the surface opposite to the substrate 51 (surface close to the active layer 52). The electrode layer and the terminal 61a are connected by solder.

The slider 60 moves relative to the disk 3 in a floating state. However, when dust is attached to the disk 3 or when the disk 3 has a defect, the slider 60 and the disk 3 are moved. There is a possibility of contact. In order to reduce the friction generated in that case, the slider 60 is preferably formed of a hard material having high friction resistance. Examples of this material include a ceramic material containing Al ₂ O ₃ , AlTiC, zirconia, or TiN. Further, in order to prevent friction, a surface treatment for increasing the friction resistance may be performed on the surface of the slider 60 on the disk 3 side. For example, high hardness can be obtained by using a DLC (Diamond Like Carbon) coating.

(Assembly method of optical head 4)
Next, an assembly method of the optical head 4 will be described with reference to FIGS. FIG. 5 is a side view of the optical head 4. FIG. 6 is a front view of the optical head 4.

First, the LD 50 is installed on the upper surface 60 a of the slider 60. The surface opposite to the substrate 51 (surface close to the active layer 52) is directed to the upper surface 60a, and the electrode layer formed on the surface opposite to the substrate 51 and the terminal 61a are connected by soldering. Further, the electrode layer formed on the substrate 51 side of the LD 50 and the terminal 62 a are connected by a bonding wire 55.

Next, the structure 40 is arranged on the upper surface 60a of the slider 60 so that the LD 50 is arranged inside the frame body 41 (opening 42) of the structure 40. For example, a suction forceps (not shown) is brought into contact with a portion of the frame body 41 where the prism 43 is not provided to hold the structure body 40, and the structure body 40 is disposed on the upper surface 60a of the slider 60 while adjusting the position. The structure 40 is disposed on the upper surface 60 a of the slider 60 by aligning the position of the incident surface 64 a of the optical waveguide 64 with the position of the prism 43. For example, the structure 40 may be held by bringing suction tweezers into contact with a portion of the frame body 41 opposite to the portion where the prism 43 is provided, or a side surface of the frame body 41.

The structure 40 can be positioned by a so-called active alignment method. In this case, a contact pin (not shown) is brought into contact with the terminal 61b and the terminal 62b of the slider 60 to supply current to the LD 50, thereby turning on the LD 50. Then, the amount of light emitted from the exit surface 64 b of the optical waveguide 64 is measured, the position of the structure 40 is adjusted so that the amount of light is maximized, and the structure 40 is fixed to the slider 60. Alternatively, the structure 40 may be positioned using an alignment mark instead of the active alignment method. For example, alignment marks are formed in advance on the upper surface 60a of the slider 60 and the structure body 40, and the structure body 40 is positioned so that the positions of the alignment marks coincide.

Then, as shown in FIGS. 5 and 6, the adhesive body 70 is applied to the upper surface 60 a of the slider 60 and the side surfaces of the structure body 40, and the adhesive body 70 is cured to fix the structure body 40 to the slider 60. . For example, an ultraviolet curable adhesive may be used as the adhesive 70. It is preferable to apply the adhesive 70 to the upper surface 60 a of the slider 60 while avoiding the magnetic head portion 63. By applying the adhesive 70 to a portion other than the magnetic head portion 63, it is possible to prevent the adhesive 70 from flowing between the prism 43 and the optical waveguide 64. Thereby, the quality and yield of the optical head 4 can be improved. The structure 40 may be fixed to the slider 60 by applying an adhesive 70 between the structure 40 and the slider 60. Also in this case, it is preferable to apply the adhesive 70 to the upper surface 60a of the slider 60 while avoiding the magnetic head portion 63.

(Function)
The operation of the optical head 4 will be described with reference to FIG. The light emitted from the end face of the active layer 52 of the LD 50 reaches the incident surface 43a of the prism 43 while spreading, enters the inside of the prism 43, and reaches the deflection surface 43b. The light reaching the deflection surface 43 b is reflected by the deflection surface 43 b and deflected in the direction of the slider 60. For example, the deflecting surface 43b deflects the optical path of this light by about 90 °. The light reflected by the deflection surface 43 b is emitted from the emission surface 43 c of the prism 43 and is coupled to the optical waveguide 64 of the slider 60. The light coupled to the optical waveguide 64 travels in the optical waveguide 64 from the incident surface 64a toward the output surface 64b, and irradiates a plasmon probe (near-field light generating element) provided on the output surface 64b. Near-field light is generated by the plasmon probe. This near-field light is emitted toward the disk 3. When the light emitted from the optical head 4 is irradiated onto the disk 3 as a minute light spot, the temperature of this irradiation region temporarily rises and the coercive force decreases. A coil installed in a magnetic recording unit (not shown) generates a magnetic field and records information in an area where the coercive force is reduced. When the area where the information is recorded is cooled, the coercive force returns to a high state and the information is retained. A magnetic information reproducing unit (not shown) reproduces information by detecting the recorded magnetization direction.

As described above, since the structure 40 provided with the prism 43 has substantially the same size as the slider 60, handling is easier than the prism 43 alone. As described above, since the structure 40 is easy to handle, the structure 40 can be easily attached to the slider 60. That is, the optical head 4 can be easily assembled.

In order to guide light from the light source to the optical waveguide of the slider, it is necessary to install an optical component (for example, a prism) for guiding the light on the slider. Since optical components such as prisms are very small, it is difficult to handle the optical component alone, and therefore it is difficult to assemble the optical head. In this embodiment, by providing the prism 43 in a part of the structure 40, the structure 40 including the prism 43 can be easily handled. That is, even if the prism 43 itself is very small, the structure 40 has almost the same size as the slider 60, so that the structure 40 including the prism 43 can be easily handled, and as a result, the optical head 4 can be easily assembled. It becomes.

Further, since the structure 40 is formed in a frame shape, the LD 50 (light source) can be disposed inside the frame body 41. That is, the LD 50 can be arranged on the slider 60 without arranging the LD 50 on the structure 40. As a result, the optical head 4 can be made thinner, and as a result, the information recording apparatus 1 can be made thinner. Conventionally, since the light source is provided on the slider via the submount and the unit substrate, the optical head is thick. On the other hand, in this embodiment, the optical head 4 can be thinned while the structure 40 and the LD 50 are provided above the slider 60.

Further, by integrally forming the frame body 41 and the prism 43, a process such as polishing for forming the prism 43 becomes unnecessary. Thereby, the structure 40 can be easily manufactured.

Further, by using the prism 43 having a refractive index larger than 1, the air conversion length from the LD 50 to the incident surface 64a of the optical waveguide 64 is shortened. Thereby, the size of the light spot irradiated to the incident surface 64a of the optical waveguide 64 is reduced, and the optical coupling efficiency in the optical waveguide 64 can be increased.

(Modification)
An optical head according to a modification will be described with reference to FIGS. FIG. 7 is a perspective view of an optical function unit according to a modification. FIG. 8 is a cross-sectional view of a part of an optical head according to a modification. FIG. 9 is a perspective view of an optical function unit according to another modification.

In order to increase the optical coupling efficiency in the optical waveguide 64, an aspherical or spherical reflection condensing surface 43d can be provided on the deflection surface 43b of the prism 43 as shown in FIG. For example, the reflective condensing surface 43d and the prism 43 can be integrally formed by injection molding, a glass mold method, or an imprint method. Further, a reflective film may be formed on the reflective condensing surface 43d. In the optical head according to the modification, the configuration other than the reflection / condensing surface 43d is the same as the configuration of the optical head according to the first embodiment described above.

As shown in FIG. 8, the light emitted from the LD 50 enters the prism 43 from the incident surface 43a and reaches the reflection / condensing surface 43d. The light reaching the reflection / condensing surface 43d is deflected in the direction of the slider 60 by the reflection / condensing surface 43d. The reflective condensing surface 43d has an aspherical shape or a spherical shape. Therefore, the light is collected by the reflection / condensing surface 43d, reaches the incident surface 64d of the optical waveguide 64, and is coupled to the optical waveguide 64. Thus, by condensing the light and coupling it to the optical waveguide 64, the optical coupling efficiency can be increased.

Further, in the intensity distribution in the far field of the light emitted from the LD 50, the FWHM (full width at half maximum) (full width at half maximum) of the component perpendicular to the active layer 52 becomes wide. Therefore, even if only the component perpendicular to the active layer 52 is collected, the optical coupling efficiency in the optical waveguide 64 can be increased. In this case, for example, as shown in FIG. 9, the deflection surface of the prism 43 may be a cylindrical reflecting cylindrical surface 43e having a curvature in a direction perpendicular to the active layer 52. As a result, the component perpendicular to the active layer 53 in the light emitted from the LD 50 is collected by the reflecting cylindrical surface 43e, so that the optical coupling efficiency in the optical waveguide 64 can be increased. The deflection surface of the prism 43 may be a cylindrical surface having a substantially elliptical cross section instead of the reflecting cylindrical surface 43e.

[Second Embodiment]
The optical head 4 according to the second embodiment will be described with reference to FIG. FIG. 10 is a cross-sectional view of the optical head 4.

In the second embodiment, the structure 40 is provided with a prism 43 having a larger cross section (cross sectional area). The rigidity of the structure 40 increases as the cross section (cross sectional area) of the prism 43 increases. The cross sections are orthogonal to the incident surface 43a, the deflecting surface 43b, and the exit surface 43c of the prism 43, respectively. The larger the cross section of the prism 43, the longer the distance from the LD 50 to the deflection surface 43b. Therefore, the light deflected by the deflecting surface 43 b is irradiated to a position shifted from the optical waveguide 64. Therefore, as the cross section of the prism 43 becomes larger, the prism 43 is arranged at a position farther from the slider 60, and the light emitting portion (active layer 52) of the LD 50 is arranged in accordance with the position of the prism 43. That is, as the cross section of the prism 43 increases, the light emitting portion (active layer 52) of the LD 50 is disposed at a position farther from the slider 60. In this case, as shown in FIG. 4, the light emitting portion (active layer 52) of the LD 50 with the surface opposite to the substrate 51 (surface close to the active layer 52) facing the upper surface 60 a of the slider 60. ) Is disposed at a position away from the slider 60, the optical head 4 becomes thick. Therefore, in the second embodiment, the LD 50 is disposed on the upper surface 60a of the slider 60 by inverting the LD 50 upside down. Specifically, the LD 50 is disposed on the upper surface 60 a of the slider 60 with the substrate 51 facing the upper surface 60 a of the slider 60. Then, the electrode layer formed on the substrate 51 side and the terminal 61a are connected by soldering. Further, the electrode layer formed on the surface opposite to the substrate 51 (surface close to the active layer 52) is connected to the terminal 62a by the bonding wire 55. Thereby, the position of the light emitting portion (active layer 52) of the LD 50 can be arranged at a position away from the slider 60 without increasing the thickness of the optical head 4.

Also, if the prism 43 is made larger, the optical path length becomes longer, so that the optical coupling efficiency in the optical waveguide 64 decreases. Therefore, in order to increase the optical coupling efficiency, it is preferable to provide the lens surface 43f on the emission surface 43c. For example, the lens surface 43 f may be formed integrally with the prism 43. Thereby, the light emitted from the emission surface 43 c is collected by the lens surface 43 f and coupled to the optical waveguide 64 of the slider 60. The lens surface 43f is, for example, an aspherical surface, a spherical surface, a cylindrical surface, or a cylindrical surface having a substantially elliptical cross section. The deflection surface 43b may be, for example, an aspherical surface, a spherical surface, a cylindrical surface, or a cylindrical surface having a substantially elliptical cross section. Note that a diffractive lens may be provided on the exit surface 43c instead of the lens surface 43f.

[Third Embodiment]
The optical head 4 according to the third embodiment will be described with reference to FIG. FIG. 11 is a cross-sectional view of the optical head 4.

In the third embodiment, the structure 40 is not provided with a prism, but a reflection surface 44 as an optical function unit is provided on a part of the frame 41. The reflection surface 44 is formed obliquely at the edge of the surface of the frame body 41 that faces the slider 60. A reflective film is formed on the reflective surface 44. In the optical head according to the third embodiment, the configuration other than the reflection surface 44 is the same as the configuration of the optical head according to the first embodiment described above. The light emitted from the LD 50 is reflected by the reflecting surface 44 and deflected in the direction of the slider 60, and is coupled to the optical waveguide 64 of the slider 60. In order to increase the optical coupling efficiency in the optical waveguide 64, the reflecting surface 44 may be an aspherical surface, a spherical surface, or a cylindrical surface.

By providing the reflection surface 44 on the frame body 41 instead of the prism, it is possible to enlarge the cross section of the frame body 41 where the reflection surface 44 is provided. Thereby, the rigidity of the structure 40 can be increased. In addition, since the optical function unit is configured only by the reflecting surface 44, it is possible to reduce the number of manufacturing steps of a mold for forming the structure 40.

The embodiment described above relates to an optically assisted magnetic recording head and an optically assisted magnetic recording device, but the optical recording head and optical recording device in which the recording medium is an optical recording disk are used. It is also possible to apply the main configuration of these embodiments. In this case, the slider 60 need not be provided with a magnetic recording unit and a magnetic information reproducing unit.

DESCRIPTION OF SYMBOLS 1 Information recording device 2 Housing | casing 3 Disc 4 Optical head 5 Head support part 6 Support axis 7 Tracking actuator 40 Structure 41 Frame 42 Opening part 43 Prism

43a Incident surface

43b Deflection surface

43c Output surface 43d Reflection condensing surface 43e Reflection cylinder Surface 43f Lens surface 44 Reflecting surface 50 Semiconductor laser diode (LD)
51 Substrate 52 Active layer 55 Bonding wire 60 Slider

60a Upper surface

61, 62 Electrode 63 Magnetic head part 64 Optical waveguide

64a Incident surface

64b Emission surface 70 Resin

Claims

A light source;
A slider that floats on the recording medium and irradiates the recording medium with light from the light source;
A frame-like structure having substantially the same size as the slider and provided on the slider;
Have
The light source is provided on the slider and inside the frame of the structure,
The structure has an optical function part that guides light emitted from the light source to the slider in a part of the frame.
An optical head characterized by that.
The optical function unit is formed integrally with the structure.
The optical head according to claim 1.
The optical function unit is
An incident surface on which light emitted from the light source is incident;
A deflecting surface that deflects light incident inside by the incident surface and guides the light to the slider;
A prism having
The optical head according to claim 1, wherein the optical head is provided.
The deflecting surface of the prism has an aspherical shape, a spherical shape, a cylindrical surface shape, or an elliptic cylindrical surface shape, condenses light from the light source, and guides it to the slider.
The optical head according to claim 3.
The light source is a semiconductor laser diode;
The semiconductor laser diode is provided on the slider with the substrate side facing the slider,
The prism further includes an exit surface that emits the light deflected by the deflection surface to the outside of the prism;
The deflecting surface or the emitting surface has an aspherical shape, a spherical shape, a cylindrical surface shape, or an elliptical cylindrical surface shape, and collects light from the light source and guides it to the slider.
The optical head according to claim 3.
The optical function unit is a reflecting surface that reflects light emitted from the light source and guides the light to the slider.
The optical head according to claim 1, wherein the optical head is provided.
A frame,
An optical function unit that is provided in a part of the frame and receives light from the inside of the frame and guides the light to the outside of the frame;
An optical element comprising:
The frame and the optical function unit are integrally molded,
The optical element according to claim 7.
The optical function unit is
An incident surface that receives light from the inside of the frame and enters the inside;
A deflecting surface that deflects light incident inside by the incident surface and guides the light to the outside of the frame;
A prism having
The optical element according to claim 7 or 8, wherein
The deflection surface of the prism has an aspheric shape, a spherical shape, a cylindrical surface shape, or an elliptic cylindrical surface shape,
The optical element according to claim 9.
The optical function unit is a reflecting surface that receives light from the inside of the frame and reflects the light to the outside of the frame.
The optical element according to claim 7 or 8, wherein
A recording medium;
An optical head according to any one of claims 1 to 6,
Have
Irradiating the recording medium with light emitted from the light source to record information on the recording medium;
An information recording apparatus characterized by that.