US20040141426A1 - Magneto-optical head and method of making coil for the same - Google Patents
Magneto-optical head and method of making coil for the same Download PDFInfo
- Publication number
- US20040141426A1 US20040141426A1 US10/617,284 US61728403A US2004141426A1 US 20040141426 A1 US20040141426 A1 US 20040141426A1 US 61728403 A US61728403 A US 61728403A US 2004141426 A1 US2004141426 A1 US 2004141426A1
- Authority
- US
- United States
- Prior art keywords
- conductive pattern
- coil
- insulating layer
- magneto
- pattern
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/1055—Disposition or mounting of transducers relative to record carriers
- G11B11/10552—Arrangements of transducers relative to each other, e.g. coupled heads, optical and magnetic head on the same base
- G11B11/10554—Arrangements of transducers relative to each other, e.g. coupled heads, optical and magnetic head on the same base the transducers being disposed on the same side of the carrier
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10532—Heads
- G11B11/10534—Heads for recording by magnetising, demagnetising or transfer of magnetisation, by radiation, e.g. for thermomagnetic recording
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/1055—Disposition or mounting of transducers relative to record carriers
- G11B11/1058—Flying heads
Definitions
- the present invention relates to a magneto-optical head used for writing data to or reading data from a magneto-optical data storage medium.
- the invention also relates to a method of making a coil used for such an MO head.
- a magneto-optical disk stores data magnetically, like a hard disk.
- Writing to an MO disk is first done by heating a portion of the disk with a laser beam. When the disk medium reaches a certain temperature (known as Curie temperature), it loses its magnetic coercivity. Then, with the use of an MO read/write head, a magnetic field is applied to the heated portion, thereby reorienting the magnetic field of the appropriate domains. This means that the data is stored.
- the recorded data is read from the disk using a polarized laser beam.
- the polarized light hits the magnetic domains on the disk, the direction of polarization is altered, in accordance with the direction of the magnetic field of the domain. In this way, the differences in the magnetic orientation of the domains are detected, whereby the data can be read.
- a conventional MO head is disclosed in JP-A-2000-76724 for example.
- the conventional MO head includes an objective 90 and a transparent plate 91 which are carried by a non-illustrated slider.
- the plate 91 is provided with a downward, transparent projection 92 aligned with the optical axis Ca of the lens 90 .
- the projection 92 has substantially the same refractive index as the plate 91 .
- Around the projection 92 is provided a coil 93 consisting of two conductive patterns 93 a for generating a required magnetic field.
- the coil 93 is covered by a transparent insulating layer 97 .
- a laser beam passes through the lens 90 and the projection 92 , and reaches the MO disk D, to form a small laser spot Ls.
- the distance between the lower surface of the plate 91 and the upper surface of the disk D is designated by h.
- the diameter of the laser beam passing from the plate 91 to the projection 92 is designated by D1.
- the diameter of the laser beam passing through the plate 91 can be made smaller than when no such projection is provided. Specifically, without the projection 92 , the laser beam is refracted to a certain degree upon leaving the plate 91 into the air, as shown in FIG. 12B. To compensate for the refraction and form an appropriately small laser spot on the disk D, the diameter D2 of the laser beam needs to be larger than the diameter D1 of FIG. 12A (here the distance between the plate 91 and the disk D is supposed to be the same for the two cases shown in FIGS. 12A and 12B)
- the laser beam is allowed to travel straight upon leaving the plate 91 , as shown in FIG. 12A, whereby the diameter D1 is relatively small. Accordingly, the inner diameter of the coil 93 is reduced, which is advantageous to generating a required magnetic field with a smaller amount of current.
- the conventional MO head has a downside as well.
- FIG. 13 of the accompanying drawings the MO head includes an objective lens 90 formed integral with a projection 92 , and a coil 93 arranged around the projection 92 .
- this conventional MO head also suffers the same problems as the MO head of FIG. 11.
- an object of the present invention is to provide an MO head capable of applying a desired magnetic field to the heated portion of the disk more efficiently than is conventionally possible.
- Another object of the present invention is to provide a method of making a coil used for an MO head.
- a magneto-optical head including: a slider held in facing relation to a storage medium; an objective lens supported by the slider for concentrating light rays; a coil provided with a center through which the light rays pass, the coil including a first conductive pattern and a second conductive pattern which is closer to the storage medium than the first conductive pattern is; and a transparent insulating layer enclosing the coil.
- the second conductive pattern is smaller in inner diameter than the first conductive pattern.
- the insulating layer is arranged to fill the center of the coil.
- the MO head may further include a transparent substrate disposed between the objective lens and the storage medium, and the coil may be provided on this substrate.
- the substrate and the insulating layer may have substantially the same refractive indexes.
- the transparent substrate may be provided with via-holes connected to the first and the second conductive patterns.
- the first conductive pattern may be embedded in the transparent substrate.
- the coil may be directly provided on the objective lens.
- each of the first and the second conductive patterns may be provided with a plurality of turns.
- the turns of the first conductive pattern may be offset radially of the coil from the turns of the second conductive pattern.
- the coil may include a connecting piece for connecting an inner turn of the first conductive pattern to an inner turn of the second conductive pattern.
- the coil may further include a first outgoing line connected to an outer turn of the first conductive pattern, and a second outgoing line connected to an outer turn of the second conductive pattern.
- the coil may include third and fourth conductive patterns arranged between the first and the second patterns, wherein the third and the fourth conductive patterns are smaller in inner diameter than the first conductive pattern but greater in inner diameter than the second conductive pattern.
- the coil may be provided with three auxiliary connecting pieces: a first connecting piece for connecting an inner end of the first conductive pattern to an inner end of the third conductive pattern, a second connecting piece for connecting an outer end of the third conductive pattern to an outer end of the fourth conductive pattern, and a third connecting piece for connecting an inner end of the fourth conductive pattern to an inner end of the second conductive pattern.
- a method of making a coil for a magneto-optical head may include the steps of: forming a first conductive pattern on a transparent substrate; forming a first transparent insulating layer filling a center of the first conductive pattern; forming a second conductive pattern on the first insulating layer, the second conductive pattern being smaller in inner diameter than the first conductive pattern; and forming a second transparent insulating layer filling a center of the second conductive pattern.
- the method may further include the step of flattening a surface of the first insulating layer before the second conductive pattern is formed.
- the method may further include the step of forming a first recess in the substrate for accommodating the first conductive pattern in the substrate.
- the step of forming the second conductive pattern may include the sub-steps of: forming on the first insulating layer a third transparent insulating layer provided with a hole; forming a fourth transparent insulating layer to cover the third insulating layer; etching the fourth insulating layer and a part of the first insulating layer via the hole of the third insulating layer, so that a second recess corresponding to the second conductive pattern is formed in the fourth insulating layer, and that a through-hole communicating with the second recess is formed in the first and the third insulating layers; and supplying a conductive material for filling the second recess and the through-hole.
- FIG. 1 is a schematic view showing the principal components of a magneto-optical disk apparatus incorporating an MO head according to a first embodiment of the present invention
- FIG. 2 is a sectional view showing the MO head shown in FIG. 1;
- FIG. 3 is an enlarged sectional view showing the MO head of FIG. 2;
- FIGS. 4 A- 4 C show two conductive patters of the coil used for the MO head
- FIGS. 5 A- 5 Q show how the coil of the MO head can be made
- FIGS. 6 A- 6 P show another way to make the coil of the MO head
- FIGS. 7 A- 7 L show still another way to make the coil of the MO head
- FIG. 8 is a sectional view showing the principal portion of an MO head according to a second embodiment of the present invention.
- FIG. 9 is a sectional view showing the principal portion of an MO head according to a third embodiment of the present invention.
- FIG. 10 is a sectional view showing an MO head according to a fourth embodiment of the present invention.
- FIG. 11 shows a conventional MO head
- FIG. 12A shows the function of a downward projection of the conventional MO head, while FIG. 12B illustrates the behavior of the laser beam where no downward projection is provided;
- FIG. 13 shows another example of conventional MO head.
- FIGS. 1 - 4 illustrating a magneto-optical (MO) head H 1 according to a first embodiment of the present invention.
- FIG. 1 shows the principal components of an MO disk apparatus A incorporating the MO head H 1 .
- the apparatus A includes a spindle 70 , a suspension 71 , an arm 72 , an actuator 73 , a mirror 74 , and an optical module 75 .
- the spindle 70 supports an MO disk D and rotates the disk D at high speed.
- the suspension 71 supports, at its inner end, the head H 1 in a manner such that the head H 1 is held in facing relation to the recording layer of the disk D.
- the suspension 71 is attached, at its outer end, to the arm 72 .
- the arm 72 is moved linearly or non-linearly in a horizontal plane by the actuator 72 .
- the head H 1 is moved relative to the disk D.
- the mirror 74 is mounted on the inner end of the arm 72 .
- the optical module 75 includes a laser beam emitting unit, a detector, a collimator, etc. The laser beam emitted from the module 75 is reflected on the mirror 74 to be directed toward the head H 1 .
- the head H 1 includes a slider 1 , a first objective 2 A, a second objective 2 B, a coil 3 , a transparent insulating layer 4 , and a transparent plate 5 .
- the slider 1 which may be made of a resin, is formed with a through-hole 11 .
- the slider 1 is held in contact with the disk by the urging force of the suspension 71 .
- the slider 1 is caused to float over the disk D by the action of the air introduced into the space between the slider 1 and the rotating disk D.
- the first objective 2 A is arranged at an enlarged, upper portion 11 a of the through-hole 11
- the second objective 2 B is arranged at a lower portion of the through-hole 11 in facing relation to the first objective 2 A.
- the second objective 2 B is provided with a spherical upper lens surface 20 a and with a flat lower lens surface 20 b .
- Using two separate objectives 2 A, 2 B in the illustrated manner serves to increase the numerical aperture (NA) of the optical system of the head H 1 , thereby improving the recording density of the disk D.
- NA numerical aperture
- the rectangular transparent plate 5 may be made of the same glass material as used for forming the first and the second objectives 2 A, 2 B.
- the thickness of the plate 5 may be about 0.2 mm.
- the plate 5 is attached to the bottom surface of the slider 1 . As shown in FIGS. 2 and 3, the upper surface of the plate 5 is held in close contact with the lower lens surface 20 b of the second objective 2 B.
- the coil 3 consists of a first pattern 30 A and a second pattern 30 B both of which may be made of copper.
- the first pattern 30 A is formed on the lower surface of the transparent plate 5 .
- the second pattern 30 B is arranged below the first pattern 30 A.
- the first pattern 30 A includes a plurality of concentric, circular portions or turns which are connected to each other via connecting portions 39 a .
- the second pattern 30 B includes a plurality of concentric, circular portions or turns which are connected to each other via connecting portions 39 b.
- the coil 3 has a central axis coinciding with the optical axis C of the second objective 2 B.
- the first and the second conductive patters 30 A, 30 B have sufficiently large inner diameters Da and Db, respectively.
- the inner diameter Da of the first pattern 30 A is greater than the inner diameter Db of the second pattern 30 B.
- the circular portions of the first pattern 30 A are horizontally offset from the counterparts of the second pattern 30 B by a predetermined distance P, as shown in FIG. 3.
- P a predetermined distance
- the circular portions of the first pattern 30 A do not overlap with the circular portions of the second pattern 30 B.
- the inner end 33 a of the first pattern 30 A is connected to the inner end 33 b of the second pattern 30 B via a connecting piece 32 .
- the outer end 34 a of the first pattern 30 A is connected to a first outgoing line 35 a extending radially of the coil 3 .
- the outer end 34 b of the second pattern 30 B is connected to a second outgoing line 35 b extending radially of the coil 3 .
- the transparent insulating layer 4 has a refractive index which is generally the same as those of the second objective 2 B and the transparent plate 5 .
- the layer 4 may be made of a transparent material such as aluminum oxide, aluminum nitride, amorphous carbon (diamond like carbon), silicon oxide or silicon nitride.
- the layer 4 encloses the coil 3 and is attached to the lower surface of the transparent plate 5 .
- the layer 4 consists of two overlapping sub-layers: a first sub-layer 4 a to enclose the first pattern 30 A and a second sub-layer 4 b to enclose the second pattern 30 B. As shown in FIG.
- the first outgoing line 35 a extends through the first sub-layer 4 a to be exposed therefrom, and the second outgoing line 35 b extends through the second sub-layer 4 b to be exposed therefrom.
- the first outgoing line 35 a is connected to a first terminal 38 a
- the second outgoing line 35 b is connected to a second terminal 38 b .
- These terminals 38 a , 38 b which may be made of copper, are connected to a power supply conductor 19 . In operation, power is supplied to the coil 3 through the conductor 19 , the terminals 38 a and 38 b , and the outgoing lines 35 a and 35 b.
- the slider 1 is caused to float above the rotating disk D.
- the gap between the disk surface and the transparent layer 4 of the floating head H 1 is in the order of micron or submicron.
- the conductor 19 for supplying power to the coil 3 is directed away from the transparent layer 4 , so that it does not extend into the gap between the disk surface and the layer 4 . Accordingly, the gap can be made small enough to bring the coil 3 appropriately close to the laser spot Ls formed on the disk surface. In this manner, it is possible to apply a strong magnetic field to the disk D at the position of the laser spot Ls.
- the laser beam emitted from the optical module 75 (FIG. 1) is caused to converge by the first objective 2 A and the second objective 2 B. After having passed through the second objective 2 b , the laser beam enters the transparent plate 5 and also the transparent layer 4 , passing through the center 31 of the coil 3 and finally reaching the disk D.
- the transparent layer 4 and plate 5 have a generally equal refractive index, which is greater than the refractive index of the air.
- the layer 4 which fills the center 31 of the coil 3 , serves the same purpose as the protruding portion 92 of the conventional MO head shown in FIG. 21 or 23 .
- the laser beam passing through the center 31 of the coil 3 can have an appropriately small diameter. Accordingly, the inner diameter of the coil 3 can also be made small.
- the coil 3 does not need to be provided around a preexisting solid object like the protrusion 92 of the prior art. Therefore, the inner diameter of the coil 3 can be made smaller than is conventionally possible. Still further, the inner diameter Db of the second pattern 30 B is made smaller than the inner diameter Da of the first pattern 30 A. In this manner, the coil 3 as a whole can be brought close to the light passage without interfering with the laser beam.
- the inner ends of the first and second patterns 30 A, 30 B are connected to each other via the vertical connecting piece 32 , while their outer ends are connected to the first and the second outgoing lines 35 a , 35 b , which extend radially outward from the center of the coil 3 .
- the laser beam passing through the center of the coil 3 does not interfere with the connecting piece 32 or the outgoing lines 35 a , 35 b.
- the coil 3 of the MO head H 1 can have an advantageously small inner diameter. As a result, a strong magnetic field generated by the coil 3 is effectively applied to and around the laser spot Ls on the disk D. Also, the small inner diameter allows the entire coil 3 to be made small, which is advantageous to reducing the power consumption of the coil 3 . When the current passing through the coil 3 is reduced, the breakage of the coil 3 due to electromigration can be prevented.
- the coil 3 is made up of two conductive patterns 30 A, 30 B.
- the two-layered coil 3 has a smaller inductance and is capable of properly responding to high frequency signals.
- the two patterns 30 A and 30 B are offset from each other in the radial direction of the coil 3 , the capacitive coupling between the two patterns is restricted, thereby reducing the stray capacitance of the coil 3 .
- the coil 3 of the above-described MO head H 1 may be fabricated in the manner shown in FIGS. 5 A- 5 Q.
- a base layer 60 A of copper is formed on a transparent substrate 5 A by sputtering or evaporation for example.
- the thickness of the layer 60 A may be about 0.1 ⁇ m.
- a thin auxiliary layer of titanium or chromium is formed beforehand, so that the base layer 60 A is properly attached to the substrate 5 A.
- a resist layer 61 A is formed on the base layer 60 A by lithography.
- the resist layer 61 A has a thickness of about 6 ⁇ m for example.
- the pattern of the resist layer 61 A corresponds to the spiral configuration of the first pattern 30 A of the coil 3 .
- a copper layer 62 A is formed on the base layer 60 A by a electroplating technique to fill the spiral pattern of the resist layer 61 A.
- the copper layer 62 A has a thickness of about 3 ⁇ m for example.
- the resist layer 61 A is removed by cleaning with the use of acetone for example.
- the exposed base layer 60 A is removed by e.g. wet cleaning with the use of acid etching solution or dry cleaning with the use of ionized argon gas caused to impinge on the base layer 60 A (ion milling).
- a copper spiral pattern (the first pattern 30 A) is formed on the substrate 5 A.
- the outgoing line 35 a (see FIG. 3) is formed simultaneously with the first pattern 30 A.
- a first transparent insulating layer 4 a is formed on the substrate 5 A to enclose the first pattern 30 A and to fill the central portion 31 a inside of the first pattern 30 A.
- the transparent layer 4 a may be made of aluminum oxide by ion plating.
- the thickness of the layer 4 a is about 6 ⁇ m for example.
- the layer 4 a is subjected to e.g. mechanical polishing.
- the first pattern 30 A may be exposed from the insulating layer 4 a as a result of the surface polishing.
- an additional transparent layer is formed on the layer 4 a to cover the exposed parts of the pattern 30 A.
- the additional layer is made of the same insulating material as used for forming the layer 4 a.
- a resist layer 61 B is formed on the first insulating layer 4 a by lithography.
- the thickness of the resist layer 61 B may be about 2 ⁇ m.
- the resist layer 61 B is provided with a hole 63 a to expose a part of the insulating layer 4 a.
- the exposed part of the insulating layer 4 a is etched away.
- a part of the inner portion of the first pattern 30 A is exposed.
- a second base layer 60 B which is similar to the first base layer 60 A, is formed to cover the insulating layer 4 a and the exposed portion of the first pattern 30 A.
- a second resist layer 61 C is formed in a predetermined pattern.
- a copper layer 62 B is formed by e.g. copper plating. At this time, the copper layer 62 B comes into contact with the inner portion of the first pattern 30 A.
- the exposed portion of the second base layer 60 B is removed.
- the second pattern 30 B is obtained.
- the second outgoing line 38 b is formed simultaneously with the second pattern 30 B.
- the second pattern 30 B is connected to the first pattern 30 A via the connecting piece 32 .
- the thus formed first and second patterns 30 A, 30 B have a common central axis C.
- the inner diameter of the second pattern 30 B is made smaller than that of the first pattern 30 A.
- the first and the second patterns 30 A, 30 B are horizontally offset relative to each other.
- a second transparent layer 4 b is formed on the first transparent layer 4 b to enclose the second pattern 30 B.
- the second layer 4 b is made of the same insulating material as used for making the first layer 4 a.
- the second layer 4 b is subjected to polishing so that the upper surface of the layer 4 b is flattened.
- the forming of the second pattern 30 B is carried out after the first transparent layer 4 a is flattened, as shown in FIGS. 5F and 5G.
- the resulting second pattern 30 B will have a substantially constant thickness, which is advantageous to preventing otherwise possible breakage of the pattern 30 B.
- FIGS. 6 A- 6 P illustrate a second fabrication method of the coil used for an MO head of the present invention.
- a predetermined pattern of resist layer 61 D is formed on the transparent substrate 5 A.
- grooves 64 are formed in the substrate 5 A by ion milling for example. The depth of each groove 64 is about 3 ⁇ m for example.
- the resist layer 61 D is removed.
- a copper layer 62 C is formed on the substrate 5 A. As illustrated, part of the copper layer 62 C fills the grooves 64 .
- the copper layer 62 C is removed from the substrate 5 A except for the portion filling the grooves 64 . This removal may be achieved by polishing. The remaining portion of the copper layer 62 C serves as a first conductive pattern 30 A of the resulting coil.
- a first transparent insulating layer 4 a , a second conductive pattern 30 B and a second transparent insulating layer 4 b are formed in this order through the steps similar to those shown in FIGS. 5 F- 50 .
- a first insulating layer 4 a is formed on the substrate 5 A to cover the first conductive pattern 30 A.
- a resist layer 61 E with a hole 63 b is formed on the insulating layer 4 a .
- a portion of the insulating layer 4 a is exposed through the hole 63 b .
- the exposed portion of the layer 4 a is etched away. As a result, an inner part of the conductive pattern 3 A is exposed to the air.
- the resist layer 61 E is removed from the substrate 5 A.
- a base layer 60 C is formed on the surface of the first layer 4 a and on the exposed inner portion of the first pattern 30 A.
- a predetermined pattern of resist layer 61 F and a conductive layer 62 D (second conductive pattern 30 B) are formed on the base layer 60 C.
- a connecting piece 32 is also formed to connect the conductive layer 62 D to the first pattern 30 A.
- a second transparent insulating layer 4 b for enclosing the second pattern 30 B is formed on the substrate 5 A and flattened in its upper surface.
- the first conductive pattern 30 A is embedded in the substrate 5 A. Due to this design, the transparent layer 4 (consisting of the first and the second insulating layers 4 a , 4 b ) does not need to enclose the pattern 30 A, and accordingly the thickness of the transparent layer 4 is made advantageously small.
- FIGS. 7 A- 7 L illustrate a third fabrication method of the coil used for an MO head of the present invention.
- a first conductive pattern 30 A embedded in a transparent substrate 5 A, is formed in the same manner as described in reference to FIGS. 6 A- 6 E.
- a first transparent insulating layer 4 a and a third transparent insulating layer 4 c are formed on the substrate 5 A.
- the first layer 4 a may be made of silicon oxide and have a thickness of about lam
- the third layer 4 c may be made of silicon nitride and have a thickness smaller than that of the first layer 4 a (300-400 nm for example).
- a resist layer 61 G with a hole 63 c is formed on the third insulating layer 4 c .
- a hole 49 corresponding in position to the hole 63 c of the resist layer 61 G is formed in the third insulating layer 4 c by etching.
- the resist layer 61 G is removed, and a fourth transparent insulating layer 4 d is formed on the third insulating layer 4 c .
- the fourth layer 4 d fills the hole 49 of the third insulating layer 4 c .
- the fourth layer 4 d may be made of the same material as used to form the first insulating layer 4 a , so that these two layers can be etched with the use of the same etchant.
- a predetermined pattern of resist layer 61 H is formed on the fourth layer 4 d , as shown in FIG. 7G. Then, the fourth layer 4 d is subjected to etching to produce a plurality of grooves 69 in the fourth layer 4 d . In this etching step, the protruding portion of the fourth layer 4 d held in the hole 49 of the third layer 4 c is etched away, which causes a portion of the first layer 4 a adjacent to the hole 49 to be exposed to the etchant.
- the first layer 4 a is made of the same material used for the fourth layer 4 d , as stated above, this particular portion of the layer 4 a is also etched away by the applied etchant. As a result, as shown in FIG. 7H, a hole 49 a extending through the three layers 4 a , 4 c and 4 d is formed simultaneously with the above-mentioned grooves 69 in the layer 4 d.
- FIG. 7I the resist layer 61 H is removed. Thereafter, as shown in FIG. 7J, a conductive layer 62 E is formed on the substrate 5 A. Then, as shown in FIG. 7K, the unnecessary upward protrusions of the conductive layer 62 E are removed by polishing for example. Thus, the second conductive pattern 30 B, connected to the first conductive pattern 30 A via a connecting piece 32 , is obtained. Finally, as shown in FIG. 7L, a second transparent insulating layer 4 b is formed to cover the second conductive pattern 30 B.
- FIG. 8 shows an MO head H 2 according to a second embodiment of the present invention.
- the head H 2 is provided with a coil 3 , a transparent insulating layer 4 and a transparent substrate 5 .
- the coil 3 includes first to fourth conductive patterns 30 a - 3 . 0 d each of which is provided with a plurality of turns.
- the third and the fourth patterns 30 c , 30 d are arranged between the first (uppermost) pattern 30 a and the second (lowermost) pattern 30 b .
- the inner diameters of the first, third, fourth and second patterns are made smaller in this order.
- the four conductive patterns 30 a - 30 d are electrically connected. Specifically, the first and the third patterns 30 a , 30 c are connected to each other at their inner ends via a first connecting piece 32 a . The third and the fourth patterns 30 c , 30 d are connected to each other at their outer ends via a second connecting piece 32 b . The fourth and the second patterns 30 d , 30 b are connected to each other at their inner ends via a third connecting piece 32 c.
- the MO head H 2 is also provided with first and second outgoing lines 35 a , 35 b .
- the first outgoing line 35 a is connected to an outer portion of the first conductive pattern 30 a
- the second outgoing line 35 b is connected to an outer portion of the second conductive pattern 30 b .
- the outgoing lines 35 a , 35 b are connected to terminals 38 .
- the first outgoing line 35 a may be connected to an outer portion of the uppermost conductive pattern, whereas the other outgoing line 35 b needs to be connected to an inner portion of the lowermost conductive pattern.
- the laser beam passing though the center of the coil 3 may be interfered with by the second outgoing line 35 b or by an via-hole connected to the inner portion of the lowermost conductive pattern.
- FIG. 9 shows an MO head H 3 according to a third embodiment of the present invention.
- the head H 3 is provided with a coil 3 (consisting of two conductive patterns 30 A and 30 B), a transparent insulating layer 4 to enclose the coil 3 , and a transparent substrate 5 .
- two via-holes 59 extending through the substrate 5 are provided. As illustrated, one of the two via-holes 59 is connected to the first conductive pattern 30 A, while the other is connected to the second conductive pattern 30 B.
- Two external terminals 59 a provided on the upper surface of the substrate 5 , are connected to the via-holes 59 .
- FIG. 10 shows an MO head H 4 according to a fourth embodiment of the present invention.
- the head H 4 is provided with an objective lens 2 , a coil 3 provided on the bottom surface 29 of the lens 2 , and an transparent insulating layer 4 enclosing the coil 3 .
- the coil 3 consists of two conductive patterns connected to outgoing lines 35 a , 35 b .
- the MO head H 4 is advantageous to e.g. cost reduction or weight reduction since it does not need a transparent substrate 5 (see e.g. FIG. 9) prepared separately from the lens 2 .
Abstract
A magneto-optical head includes a slider, an objective lens, a coil and a transparent insulating layer. The coil is provided with upper and lower conductive patterns, wherein the lower pattern is brought closer to a storage medium than the upper pattern is. The lower pattern is made smaller in inner diameter than the upper pattern. The insulating layer fills the center of the coil.
Description
- 1. Field of the Invention
- The present invention relates to a magneto-optical head used for writing data to or reading data from a magneto-optical data storage medium. The invention also relates to a method of making a coil used for such an MO head.
- 2. Description of the Related Art
- As is known, a magneto-optical disk stores data magnetically, like a hard disk. Writing to an MO disk is first done by heating a portion of the disk with a laser beam. When the disk medium reaches a certain temperature (known as Curie temperature), it loses its magnetic coercivity. Then, with the use of an MO read/write head, a magnetic field is applied to the heated portion, thereby reorienting the magnetic field of the appropriate domains. This means that the data is stored.
- The recorded data is read from the disk using a polarized laser beam. When the polarized light hits the magnetic domains on the disk, the direction of polarization is altered, in accordance with the direction of the magnetic field of the domain. In this way, the differences in the magnetic orientation of the domains are detected, whereby the data can be read.
- A conventional MO head is disclosed in JP-A-2000-76724 for example. As shown in FIG. 11 of the accompanying drawings, the conventional MO head includes an objective90 and a
transparent plate 91 which are carried by a non-illustrated slider. Theplate 91 is provided with a downward,transparent projection 92 aligned with the optical axis Ca of thelens 90. Theprojection 92 has substantially the same refractive index as theplate 91. Around theprojection 92 is provided acoil 93 consisting of twoconductive patterns 93 a for generating a required magnetic field. Thecoil 93 is covered by atransparent insulating layer 97. - In operation, as shown in FIG. 12A, a laser beam passes through the
lens 90 and theprojection 92, and reaches the MO disk D, to form a small laser spot Ls. In the figure, the distance between the lower surface of theplate 91 and the upper surface of the disk D is designated by h. The diameter of the laser beam passing from theplate 91 to theprojection 92 is designated by D1. - Due to the
projection 92, the diameter of the laser beam passing through theplate 91 can be made smaller than when no such projection is provided. Specifically, without theprojection 92, the laser beam is refracted to a certain degree upon leaving theplate 91 into the air, as shown in FIG. 12B. To compensate for the refraction and form an appropriately small laser spot on the disk D, the diameter D2 of the laser beam needs to be larger than the diameter D1 of FIG. 12A (here the distance between theplate 91 and the disk D is supposed to be the same for the two cases shown in FIGS. 12A and 12B) - With the
projection 92, however, the laser beam is allowed to travel straight upon leaving theplate 91, as shown in FIG. 12A, whereby the diameter D1 is relatively small. Accordingly, the inner diameter of thecoil 93 is reduced, which is advantageous to generating a required magnetic field with a smaller amount of current. - Though having such an advantageous feature, the conventional MO head has a downside as well. First, it takes an extra time to form the
projection 92 on theplate 91. Second, it may be difficult to form theprojection 92 with accuracy. Third, the inner diameter of thecoil 93 cannot be made smaller than the diameter of theprojection 92. - Another example of conventional MO head is disclosed in JP-A-10(1998)-320863. As shown in FIG. 13 of the accompanying drawings, the MO head includes an
objective lens 90 formed integral with aprojection 92, and acoil 93 arranged around theprojection 92. Clearly, this conventional MO head also suffers the same problems as the MO head of FIG. 11. - The present invention has been proposed under the circumstances described above. Therefore, an object of the present invention is to provide an MO head capable of applying a desired magnetic field to the heated portion of the disk more efficiently than is conventionally possible. Another object of the present invention is to provide a method of making a coil used for an MO head.
- According to a first aspect of the present invention, there is provided a magneto-optical head including: a slider held in facing relation to a storage medium; an objective lens supported by the slider for concentrating light rays; a coil provided with a center through which the light rays pass, the coil including a first conductive pattern and a second conductive pattern which is closer to the storage medium than the first conductive pattern is; and a transparent insulating layer enclosing the coil. The second conductive pattern is smaller in inner diameter than the first conductive pattern. The insulating layer is arranged to fill the center of the coil.
- In accordance with a preferred embodiment, the MO head may further include a transparent substrate disposed between the objective lens and the storage medium, and the coil may be provided on this substrate.
- Preferably, the substrate and the insulating layer may have substantially the same refractive indexes.
- Preferably, the transparent substrate may be provided with via-holes connected to the first and the second conductive patterns.
- For reducing the overall size of the MO head, the first conductive pattern may be embedded in the transparent substrate. In accordance with another preferred embodiment, the coil may be directly provided on the objective lens.
- Preferably, each of the first and the second conductive patterns may be provided with a plurality of turns.
- Preferably, the turns of the first conductive pattern may be offset radially of the coil from the turns of the second conductive pattern.
- Preferably, the coil may include a connecting piece for connecting an inner turn of the first conductive pattern to an inner turn of the second conductive pattern.
- Preferably, the coil may further include a first outgoing line connected to an outer turn of the first conductive pattern, and a second outgoing line connected to an outer turn of the second conductive pattern.
- In addition to the first and the second conductive patterns, the coil may include third and fourth conductive patterns arranged between the first and the second patterns, wherein the third and the fourth conductive patterns are smaller in inner diameter than the first conductive pattern but greater in inner diameter than the second conductive pattern.
- When the four conductive patterns are used, the coil may be provided with three auxiliary connecting pieces: a first connecting piece for connecting an inner end of the first conductive pattern to an inner end of the third conductive pattern, a second connecting piece for connecting an outer end of the third conductive pattern to an outer end of the fourth conductive pattern, and a third connecting piece for connecting an inner end of the fourth conductive pattern to an inner end of the second conductive pattern.
- According to a second aspect of the present invention, there is provided a method of making a coil for a magneto-optical head. The method may include the steps of: forming a first conductive pattern on a transparent substrate; forming a first transparent insulating layer filling a center of the first conductive pattern; forming a second conductive pattern on the first insulating layer, the second conductive pattern being smaller in inner diameter than the first conductive pattern; and forming a second transparent insulating layer filling a center of the second conductive pattern.
- Preferably, the method may further include the step of flattening a surface of the first insulating layer before the second conductive pattern is formed.
- In accordance with a preferred embodiment, the method may further include the step of forming a first recess in the substrate for accommodating the first conductive pattern in the substrate.
- In accordance with another preferred embodiment, the step of forming the second conductive pattern may include the sub-steps of: forming on the first insulating layer a third transparent insulating layer provided with a hole; forming a fourth transparent insulating layer to cover the third insulating layer; etching the fourth insulating layer and a part of the first insulating layer via the hole of the third insulating layer, so that a second recess corresponding to the second conductive pattern is formed in the fourth insulating layer, and that a through-hole communicating with the second recess is formed in the first and the third insulating layers; and supplying a conductive material for filling the second recess and the through-hole.
- Other features and advantages of the present invention will become apparent from the detailed description given below with reference to the accompanying drawings.
- FIG. 1 is a schematic view showing the principal components of a magneto-optical disk apparatus incorporating an MO head according to a first embodiment of the present invention;
- FIG. 2 is a sectional view showing the MO head shown in FIG. 1;
- FIG. 3 is an enlarged sectional view showing the MO head of FIG. 2;
- FIGS.4A-4C show two conductive patters of the coil used for the MO head;
- FIGS.5A-5Q show how the coil of the MO head can be made;
- FIGS.6A-6P show another way to make the coil of the MO head;
- FIGS.7A-7L show still another way to make the coil of the MO head;
- FIG. 8 is a sectional view showing the principal portion of an MO head according to a second embodiment of the present invention;
- FIG. 9 is a sectional view showing the principal portion of an MO head according to a third embodiment of the present invention;
- FIG. 10 is a sectional view showing an MO head according to a fourth embodiment of the present invention;
- FIG. 11 shows a conventional MO head;
- FIG. 12A shows the function of a downward projection of the conventional MO head, while FIG. 12B illustrates the behavior of the laser beam where no downward projection is provided; and
- FIG. 13 shows another example of conventional MO head.
- The preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
- Reference is first made to FIGS.1-4 illustrating a magneto-optical (MO) head H1 according to a first embodiment of the present invention.
- FIG. 1 shows the principal components of an MO disk apparatus A incorporating the MO head H1. As illustrated, the apparatus A includes a
spindle 70, asuspension 71, anarm 72, anactuator 73, amirror 74, and anoptical module 75. Specifically, thespindle 70 supports an MO disk D and rotates the disk D at high speed. Thesuspension 71 supports, at its inner end, the head H1 in a manner such that the head H1 is held in facing relation to the recording layer of the disk D. Thesuspension 71 is attached, at its outer end, to thearm 72. Thearm 72 is moved linearly or non-linearly in a horizontal plane by theactuator 72. Accordingly, the head H1 is moved relative to the disk D. Themirror 74 is mounted on the inner end of thearm 72. Though not shown, theoptical module 75 includes a laser beam emitting unit, a detector, a collimator, etc. The laser beam emitted from themodule 75 is reflected on themirror 74 to be directed toward the head H1. - As shown in FIG. 2, the head H1 includes a slider 1, a first objective 2A, a second objective 2B, a
coil 3, a transparent insulatinglayer 4, and atransparent plate 5. - The slider1, which may be made of a resin, is formed with a through-
hole 11. When the disk D is at rest, the slider 1 is held in contact with the disk by the urging force of thesuspension 71. When the disk D is rotated at high speed, the slider 1 is caused to float over the disk D by the action of the air introduced into the space between the slider 1 and the rotating disk D. - The first objective2A is arranged at an enlarged, upper portion 11 a of the through-
hole 11, while the second objective 2B is arranged at a lower portion of the through-hole 11 in facing relation to the first objective 2A. The second objective 2B is provided with a sphericalupper lens surface 20 a and with a flatlower lens surface 20 b. Using twoseparate objectives - The rectangular
transparent plate 5 may be made of the same glass material as used for forming the first and thesecond objectives plate 5 may be about 0.2 mm. Theplate 5 is attached to the bottom surface of the slider 1. As shown in FIGS. 2 and 3, the upper surface of theplate 5 is held in close contact with thelower lens surface 20 b of the second objective 2B. - The
coil 3 consists of afirst pattern 30A and asecond pattern 30B both of which may be made of copper. Thefirst pattern 30A is formed on the lower surface of thetransparent plate 5. Thesecond pattern 30B is arranged below thefirst pattern 30A. As shown in FIG. 4A, thefirst pattern 30A includes a plurality of concentric, circular portions or turns which are connected to each other via connectingportions 39 a. Similarly, as shown in FIG. 4B, thesecond pattern 30B includes a plurality of concentric, circular portions or turns which are connected to each other via connectingportions 39 b. - As shown in FIG. 3, the
coil 3 has a central axis coinciding with the optical axis C of the second objective 2B. To allow the laser beam to pass through thecenter 31 of thecoil 3, the first and the secondconductive patters first pattern 30A is greater than the inner diameter Db of thesecond pattern 30B. - The circular portions of the
first pattern 30A are horizontally offset from the counterparts of thesecond pattern 30B by a predetermined distance P, as shown in FIG. 3. Thus, as viewed in the vertical direction (see FIG. 4C), the circular portions of thefirst pattern 30A do not overlap with the circular portions of thesecond pattern 30B. - As shown in FIGS. 3 and 4, the
inner end 33 a of thefirst pattern 30A is connected to theinner end 33 b of thesecond pattern 30B via a connectingpiece 32. Theouter end 34 a of thefirst pattern 30A is connected to a firstoutgoing line 35 a extending radially of thecoil 3. Similarly, theouter end 34 b of thesecond pattern 30B is connected to a secondoutgoing line 35 b extending radially of thecoil 3. - The transparent
insulating layer 4 has a refractive index which is generally the same as those of the second objective 2B and thetransparent plate 5. Thelayer 4 may be made of a transparent material such as aluminum oxide, aluminum nitride, amorphous carbon (diamond like carbon), silicon oxide or silicon nitride. Thelayer 4 encloses thecoil 3 and is attached to the lower surface of thetransparent plate 5. To be precise, thelayer 4 consists of two overlapping sub-layers: afirst sub-layer 4 a to enclose thefirst pattern 30A and asecond sub-layer 4 b to enclose thesecond pattern 30B. As shown in FIG. 3, the firstoutgoing line 35 a extends through thefirst sub-layer 4 a to be exposed therefrom, and the secondoutgoing line 35 b extends through thesecond sub-layer 4 b to be exposed therefrom. At their exposed ends, the firstoutgoing line 35 a is connected to a first terminal 38 a, while the secondoutgoing line 35 b is connected to asecond terminal 38 b. Theseterminals power supply conductor 19. In operation, power is supplied to thecoil 3 through theconductor 19, theterminals outgoing lines - The function of the above head H1 will now be described below.
- In operation, as stated previously, the slider1 is caused to float above the rotating disk D. The gap between the disk surface and the
transparent layer 4 of the floating head H1 is in the order of micron or submicron. According to the first embodiment, as shown in FIG. 3, theconductor 19 for supplying power to thecoil 3 is directed away from thetransparent layer 4, so that it does not extend into the gap between the disk surface and thelayer 4. Accordingly, the gap can be made small enough to bring thecoil 3 appropriately close to the laser spot Ls formed on the disk surface. In this manner, it is possible to apply a strong magnetic field to the disk D at the position of the laser spot Ls. - As shown in FIG. 2, the laser beam emitted from the optical module75 (FIG. 1) is caused to converge by the first objective 2A and the second objective 2B. After having passed through the second objective 2 b, the laser beam enters the
transparent plate 5 and also thetransparent layer 4, passing through thecenter 31 of thecoil 3 and finally reaching the disk D. - According to the first embodiment, the
transparent layer 4 andplate 5 have a generally equal refractive index, which is greater than the refractive index of the air. Thus, thelayer 4, which fills thecenter 31 of thecoil 3, serves the same purpose as the protrudingportion 92 of the conventional MO head shown in FIG. 21 or 23. This means that in the head H1, the laser beam passing through thecenter 31 of thecoil 3 can have an appropriately small diameter. Accordingly, the inner diameter of thecoil 3 can also be made small. - Further, in the MO head H1, the
coil 3 does not need to be provided around a preexisting solid object like theprotrusion 92 of the prior art. Therefore, the inner diameter of thecoil 3 can be made smaller than is conventionally possible. Still further, the inner diameter Db of thesecond pattern 30B is made smaller than the inner diameter Da of thefirst pattern 30A. In this manner, thecoil 3 as a whole can be brought close to the light passage without interfering with the laser beam. - In the MO head H1, the inner ends of the first and
second patterns piece 32, while their outer ends are connected to the first and the secondoutgoing lines coil 3. Thus, the laser beam passing through the center of thecoil 3 does not interfere with the connectingpiece 32 or theoutgoing lines - Due to the above-described features, the
coil 3 of the MO head H1 can have an advantageously small inner diameter. As a result, a strong magnetic field generated by thecoil 3 is effectively applied to and around the laser spot Ls on the disk D. Also, the small inner diameter allows theentire coil 3 to be made small, which is advantageous to reducing the power consumption of thecoil 3. When the current passing through thecoil 3 is reduced, the breakage of thecoil 3 due to electromigration can be prevented. - In the MO head H1, the
coil 3 is made up of twoconductive patterns coil 3 has a smaller inductance and is capable of properly responding to high frequency signals. Further, since the twopatterns coil 3, the capacitive coupling between the two patterns is restricted, thereby reducing the stray capacitance of thecoil 3. - The
coil 3 of the above-described MO head H1 may be fabricated in the manner shown in FIGS. 5A-5Q. - First, as shown in FIG. 5A, a
base layer 60A of copper is formed on atransparent substrate 5A by sputtering or evaporation for example. The thickness of thelayer 60A may be about 0.1 μm. Though not illustrated, a thin auxiliary layer of titanium or chromium is formed beforehand, so that thebase layer 60A is properly attached to thesubstrate 5A. - Then, as shown in FIG. 5B, a resist
layer 61A is formed on thebase layer 60A by lithography. The resistlayer 61A has a thickness of about 6 μm for example. The pattern of the resistlayer 61A corresponds to the spiral configuration of thefirst pattern 30A of thecoil 3. - Then, as shown in FIG. 5C, a
copper layer 62A is formed on thebase layer 60A by a electroplating technique to fill the spiral pattern of the resistlayer 61A. Thecopper layer 62A has a thickness of about 3 μm for example. - Then, as shown in FIG. 5D, the resist
layer 61A is removed by cleaning with the use of acetone for example. Thereafter, as shown in FIG. 5E, the exposedbase layer 60A is removed by e.g. wet cleaning with the use of acid etching solution or dry cleaning with the use of ionized argon gas caused to impinge on thebase layer 60A (ion milling). As a result of the removal, a copper spiral pattern (thefirst pattern 30A) is formed on thesubstrate 5A. Though not illustrated, theoutgoing line 35 a (see FIG. 3) is formed simultaneously with thefirst pattern 30A. - Then, as shown in FIG. 5F, a first transparent insulating
layer 4 a is formed on thesubstrate 5A to enclose thefirst pattern 30A and to fill thecentral portion 31 a inside of thefirst pattern 30A. (In the figure, the sign “C1” refers to the central axis of thefirst pattern 30A.) Thetransparent layer 4 a may be made of aluminum oxide by ion plating. The thickness of thelayer 4 a is about 6 μm for example. Initially, there may be some irregularities on the upper surface of thelayer 4 a since thelayer 4 a overlaps thefirst pattern 30A. To flatten the uneven upper surface, as shown in FIG. 5G, thelayer 4 a is subjected to e.g. mechanical polishing. When the initial thickness of thelayer 4 a is rather small, thefirst pattern 30A may be exposed from the insulatinglayer 4 a as a result of the surface polishing. In this case, an additional transparent layer is formed on thelayer 4 a to cover the exposed parts of thepattern 30A. The additional layer is made of the same insulating material as used for forming thelayer 4 a. - Then, as shown in FIG. 5H, a resist
layer 61B is formed on the first insulatinglayer 4 a by lithography. The thickness of the resistlayer 61B may be about 2 μm. The resistlayer 61B is provided with ahole 63 a to expose a part of the insulatinglayer 4 a. - Then, as shown in FIG. 5I, the exposed part of the insulating
layer 4 a is etched away. Thus, a part of the inner portion of thefirst pattern 30A is exposed. - Then, as shown in FIG. 5J, the resist
layer 61B is removed. - Then, as shown in FIG. 5K, a
second base layer 60B, which is similar to thefirst base layer 60A, is formed to cover the insulatinglayer 4 a and the exposed portion of thefirst pattern 30A. - Then, as shown in FIG. 5L, a second resist
layer 61C is formed in a predetermined pattern. - Then, as shown in FIG. 5M, a
copper layer 62B is formed by e.g. copper plating. At this time, thecopper layer 62B comes into contact with the inner portion of thefirst pattern 30A. - Then, as shown in FIG. 5N, the resist
layer 61C is removed. - Then, as shown in FIG. 5O, the exposed portion of the
second base layer 60B is removed. Thus, thesecond pattern 30B is obtained. Though not illustrated, the secondoutgoing line 38 b is formed simultaneously with thesecond pattern 30B. Thesecond pattern 30B is connected to thefirst pattern 30A via the connectingpiece 32. As illustrated, the thus formed first andsecond patterns second pattern 30B is made smaller than that of thefirst pattern 30A. The first and thesecond patterns - Then, as shown in FIG. 5P, a second
transparent layer 4 b is formed on the firsttransparent layer 4 b to enclose thesecond pattern 30B. Thesecond layer 4 b is made of the same insulating material as used for making thefirst layer 4 a. - Finally, as shown in FIG. 5Q, the
second layer 4 b is subjected to polishing so that the upper surface of thelayer 4 b is flattened. - In the above-described process, the forming of the
second pattern 30B is carried out after the firsttransparent layer 4 a is flattened, as shown in FIGS. 5F and 5G. In this manner, the resultingsecond pattern 30B will have a substantially constant thickness, which is advantageous to preventing otherwise possible breakage of thepattern 30B. - FIGS.6A-6P illustrate a second fabrication method of the coil used for an MO head of the present invention.
- First, as shown in FIG. 6A, a predetermined pattern of resist
layer 61D is formed on thetransparent substrate 5A. Then, as shown in FIG. 6B,grooves 64 are formed in thesubstrate 5A by ion milling for example. The depth of eachgroove 64 is about 3 μm for example. - Then, as shown in FIG. 6C, the resist
layer 61D is removed. Then, as shown in FIG. 6D, acopper layer 62C is formed on thesubstrate 5A. As illustrated, part of thecopper layer 62C fills thegrooves 64. - Then, as shown in FIG. 6E, the
copper layer 62C is removed from thesubstrate 5A except for the portion filling thegrooves 64. This removal may be achieved by polishing. The remaining portion of thecopper layer 62C serves as a firstconductive pattern 30A of the resulting coil. - After the
first pattern 30A is formed, a first transparent insulatinglayer 4 a, a secondconductive pattern 30B and a second transparent insulatinglayer 4 b are formed in this order through the steps similar to those shown in FIGS. 5F-50. Specifically, as shown in FIG. 6F, a first insulatinglayer 4 a is formed on thesubstrate 5A to cover the firstconductive pattern 30A. Then, as shown in FIG. 6G, a resistlayer 61E with ahole 63 b is formed on the insulatinglayer 4 a. Thus, a portion of the insulatinglayer 4 a is exposed through thehole 63 b. Then, as shown in FIG. 6H, the exposed portion of thelayer 4 a is etched away. As a result, an inner part of the conductive pattern 3A is exposed to the air. - Then, as shown in FIG. 6I, the resist
layer 61E is removed from thesubstrate 5A. Then, as shown in FIG. 6J, abase layer 60C is formed on the surface of thefirst layer 4 a and on the exposed inner portion of thefirst pattern 30A. - Then, as shown in FIGS. 6K and 6L, a predetermined pattern of resist
layer 61F and aconductive layer 62D (secondconductive pattern 30B) are formed on thebase layer 60C. At this time, a connectingpiece 32 is also formed to connect theconductive layer 62D to thefirst pattern 30A. - Thereafter, as shown in FIGS. 6M and 6N, the resist
layer 61F and the exposedbase layer 60C are removed. As a result, the secondconductive pattern 30B is obtained. - Finally, as shown in FIGS. 60 and 6P, a second transparent insulating
layer 4 b for enclosing thesecond pattern 30B is formed on thesubstrate 5A and flattened in its upper surface. - According to the second method described above, the first
conductive pattern 30A is embedded in thesubstrate 5A. Due to this design, the transparent layer 4 (consisting of the first and the second insulatinglayers pattern 30A, and accordingly the thickness of thetransparent layer 4 is made advantageously small. - FIGS.7A-7L illustrate a third fabrication method of the coil used for an MO head of the present invention. Referring to FIG. 7A, a first
conductive pattern 30A, embedded in atransparent substrate 5A, is formed in the same manner as described in reference to FIGS. 6A-6E. Then, as shown in FIG. 7B, a first transparent insulatinglayer 4 a and a third transparent insulatinglayer 4 c are formed on thesubstrate 5A. Thefirst layer 4 a may be made of silicon oxide and have a thickness of about lam, while thethird layer 4 c may be made of silicon nitride and have a thickness smaller than that of thefirst layer 4 a (300-400 nm for example). - Then, as shown in FIG. 7C, a resist
layer 61G with ahole 63 c is formed on the third insulatinglayer 4 c. Then, as shown in FIG. 7D, ahole 49 corresponding in position to thehole 63 c of the resistlayer 61G is formed in the third insulatinglayer 4 c by etching. Then, as shown in FIGS. 7E and 7F, the resistlayer 61G is removed, and a fourth transparent insulatinglayer 4 d is formed on the third insulatinglayer 4 c. As shown in FIG. 7F, thefourth layer 4 d fills thehole 49 of the third insulatinglayer 4 c. Thefourth layer 4 d may be made of the same material as used to form the first insulatinglayer 4 a, so that these two layers can be etched with the use of the same etchant. - After the
fourth layer 4 d is formed, a predetermined pattern of resistlayer 61H is formed on thefourth layer 4 d, as shown in FIG. 7G. Then, thefourth layer 4 d is subjected to etching to produce a plurality ofgrooves 69 in thefourth layer 4 d. In this etching step, the protruding portion of thefourth layer 4 d held in thehole 49 of thethird layer 4 c is etched away, which causes a portion of thefirst layer 4 a adjacent to thehole 49 to be exposed to the etchant. Since thefirst layer 4 a is made of the same material used for thefourth layer 4 d, as stated above, this particular portion of thelayer 4 a is also etched away by the applied etchant. As a result, as shown in FIG. 7H, ahole 49 a extending through the threelayers grooves 69 in thelayer 4 d. - Then, as shown in FIG. 7I, the resist
layer 61H is removed. Thereafter, as shown in FIG. 7J, aconductive layer 62E is formed on thesubstrate 5A. Then, as shown in FIG. 7K, the unnecessary upward protrusions of theconductive layer 62E are removed by polishing for example. Thus, the secondconductive pattern 30B, connected to the firstconductive pattern 30A via a connectingpiece 32, is obtained. Finally, as shown in FIG. 7L, a second transparent insulatinglayer 4 b is formed to cover the secondconductive pattern 30B. - FIG. 8 shows an MO head H2 according to a second embodiment of the present invention. The head H2 is provided with a
coil 3, a transparent insulatinglayer 4 and atransparent substrate 5. Thecoil 3 includes first to fourth conductive patterns 30 a-3.0 d each of which is provided with a plurality of turns. As illustrated, the third and thefourth patterns 30 c, 30 d are arranged between the first (uppermost) pattern 30 a and the second (lowermost)pattern 30 b. The inner diameters of the first, third, fourth and second patterns are made smaller in this order. - The four conductive patterns30 a-30 d are electrically connected. Specifically, the first and the
third patterns 30 a, 30 c are connected to each other at their inner ends via a first connecting piece 32 a. The third and thefourth patterns 30 c, 30 d are connected to each other at their outer ends via a second connectingpiece 32 b. The fourth and thesecond patterns 30 d, 30 b are connected to each other at their inner ends via a third connecting piece 32 c. - The MO head H2 is also provided with first and second
outgoing lines outgoing line 35 a is connected to an outer portion of the first conductive pattern 30 a, while the secondoutgoing line 35 b is connected to an outer portion of the secondconductive pattern 30 b. At their exposed ends, theoutgoing lines terminals 38. - In the preferred embodiment shown in FIG. 8, use is made of four conductive patterns for the
coil 3. According to the present invention, a larger even number of conductive patterns may be used for constituting thecoil 3. An even number of conductive patterns are advantageous since the twooutgoing lines outgoing line 35 a may be connected to an outer portion of the uppermost conductive pattern, whereas the otheroutgoing line 35 b needs to be connected to an inner portion of the lowermost conductive pattern. In such an instance, disadvantageously, the laser beam passing though the center of thecoil 3 may be interfered with by the secondoutgoing line 35 b or by an via-hole connected to the inner portion of the lowermost conductive pattern. - FIG. 9 shows an MO head H3 according to a third embodiment of the present invention. The head H3 is provided with a coil 3 (consisting of two
conductive patterns layer 4 to enclose thecoil 3, and atransparent substrate 5. In this embodiment, two via-holes 59 extending through thesubstrate 5 are provided. As illustrated, one of the two via-holes 59 is connected to the firstconductive pattern 30A, while the other is connected to the secondconductive pattern 30B. Twoexternal terminals 59 a, provided on the upper surface of thesubstrate 5, are connected to the via-holes 59. - FIG. 10 shows an MO head H4 according to a fourth embodiment of the present invention. The head H4 is provided with an
objective lens 2, acoil 3 provided on thebottom surface 29 of thelens 2, and an transparentinsulating layer 4 enclosing thecoil 3. Thecoil 3 consists of two conductive patterns connected tooutgoing lines lens 2. - The present invention being thus described, it is obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to those skilled in the art are intended to be included within the scope of the following claims.
Claims (16)
1. A magneto-optical head comprising:
a slider held in facing relation to a storage medium;
an objective lens supported by the slider for concentrating light rays;
a coil provided with a center through which the light rays pass, the coil including a first conductive pattern and a second conductive pattern which is closer to the storage medium than the first conductive pattern is; and
a transparent insulating layer enclosing the coil;
wherein the second conductive pattern is smaller in inner diameter than the first conductive pattern, the insulating layer filling the center of the coil.
2. The magneto-optical head according to claim 1 , further comprising a transparent substrate arranged between the lens and the storage medium, the coil being provided on the substrate.
3. The magneto-optical head according to claim 2 , wherein the substrate and the insulating layer have substantially same refractive indexes.
4. The magneto-optical head according to claim 2 , wherein the substrate is provided with via-holes connected to the first and the second conductive patterns.
5. The magneto-optical head according to claim 2 , wherein the first conductive pattern is embedded in the substrate.
6. The magneto-optical head according to claim 1 , wherein the coil is provided on the lens.
7. The magneto-optical head according to claim 1 , wherein each of the first and the second conductive patterns is provided with a plurality of turns.
8. The magneto-optical head according to claim 7 , wherein the turns of the first conductive pattern are offset radially of the coil from the turns of the second conductive pattern.
9. The magneto-optical head according to claim 7 , wherein the coil includes a connecting piece for connecting an inner turn of the first conductive pattern to an inner turn of the second conductive pattern.
10. The magneto-optical head according to claim 7 , wherein the coil includes a first outgoing line connected to an outer turn of the first conductive pattern, and a second outgoing line connected to an outer turn of the second conductive pattern.
11. The magneto-optical head according to claim 1 , wherein the coil includes third and fourth conductive patterns arranged between the first and the second conductive patterns, the third and the fourth conductive patterns being smaller in inner diameter than the first conductive pattern but greater in inner diameter than the second conductive pattern.
12. The magneto-optical head according to claim 11 , wherein the coil is provided with a first connecting piece for connecting an inner end of the first conductive pattern to an inner end of the third conductive pattern, a second connecting piece for connecting an outer end of the third conductive pattern to an outer end of the fourth conductive pattern, and a third connecting piece for connecting an inner end of the fourth conductive pattern to an inner end of the second conductive pattern.
13. A method of making a coil for a magneto-optical head comprising the steps of:
forming a first conductive pattern on a transparent substrate;
forming a first transparent insulating layer filling a center of the first conductive pattern;
forming a second conductive pattern on the first insulating layer, the second conductive pattern being smaller in inner diameter than the first conductive pattern; and
forming a second transparent insulating layer filling a center of the second conductive pattern.
14. The method according to claim 13 , further comprising the step of flattening a surface of the first insulating layer before the second conductive pattern is formed.
15. The method according to claim 13 , further comprising the step of forming a first recess in the substrate for, embedding the first conductive pattern in the substrate.
16. The method according to claim 13 , wherein the step of forming the second conductive pattern comprises the sub-steps of:
forming on the first insulating layer a third transparent insulating layer provided with a hole;
forming a fourth transparent insulating layer to cover the third insulating layer;
etching the fourth insulating layer and a part of the first insulating layer via the hole of the third insulating layer, so that a second recess corresponding to the second conductive pattern is formed in the fourth insulating layer, and that a through-hole communicating with the second recess is formed in the first and the third insulating layers; and
supplying a conductive material for filling the second recess and the through-hole.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/617,284 US20040141426A1 (en) | 2000-09-07 | 2003-07-10 | Magneto-optical head and method of making coil for the same |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2000271208A JP3668112B2 (en) | 2000-09-07 | 2000-09-07 | Magneto-optical head and method of manufacturing magneto-optical head coil |
JP2000-271208 | 2000-09-07 | ||
US09/794,369 US6618330B1 (en) | 2000-09-07 | 2001-02-27 | Magneto-optical head and method of making coil for the same |
US10/617,284 US20040141426A1 (en) | 2000-09-07 | 2003-07-10 | Magneto-optical head and method of making coil for the same |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/794,369 Continuation US6618330B1 (en) | 2000-09-07 | 2001-02-27 | Magneto-optical head and method of making coil for the same |
Publications (1)
Publication Number | Publication Date |
---|---|
US20040141426A1 true US20040141426A1 (en) | 2004-07-22 |
Family
ID=18757529
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/794,369 Expired - Fee Related US6618330B1 (en) | 2000-09-07 | 2001-02-27 | Magneto-optical head and method of making coil for the same |
US10/617,284 Abandoned US20040141426A1 (en) | 2000-09-07 | 2003-07-10 | Magneto-optical head and method of making coil for the same |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/794,369 Expired - Fee Related US6618330B1 (en) | 2000-09-07 | 2001-02-27 | Magneto-optical head and method of making coil for the same |
Country Status (2)
Country | Link |
---|---|
US (2) | US6618330B1 (en) |
JP (1) | JP3668112B2 (en) |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090088701A1 (en) * | 2006-03-20 | 2009-04-02 | Novo Nordisk A/S | Contact Free Reading of Cartridge Identification Codes |
US7614545B2 (en) * | 2003-03-24 | 2009-11-10 | Novo Nordisk A/S | Electronic marking of a medication cartridge |
US20100012735A1 (en) * | 2000-08-10 | 2010-01-21 | Novo Nordisk A/S | Support for a Cartridge for Transferring an Electronically Readable Item of Information from the Cartridge to an Electronic Circuit |
US20100106100A1 (en) * | 2007-03-21 | 2010-04-29 | Novo Nordisk A/S | Medical delivery system having container recognition and container for use with the medical delivery system |
US20100194537A1 (en) * | 2007-06-09 | 2010-08-05 | Novo Nordisk A/S | Contact free reading of reservoir identification codes |
US8049519B2 (en) | 2006-04-26 | 2011-11-01 | Novo Nordisk A/S | Contact free absolute position determination of a moving element in a medication delivery device |
US8197449B2 (en) | 2005-05-10 | 2012-06-12 | Novo Nordisk A/S | Injection device comprising an optical sensor |
US8638108B2 (en) | 2005-09-22 | 2014-01-28 | Novo Nordisk A/S | Device and method for contact free absolute position determination |
US8994382B2 (en) | 2006-04-12 | 2015-03-31 | Novo Nordisk A/S | Absolute position determination of movably mounted member in medication delivery device |
US9186465B2 (en) | 2008-11-06 | 2015-11-17 | Novo Nordisk A/S | Electronically assisted drug delivery device |
US9950117B2 (en) | 2009-02-13 | 2018-04-24 | Novo Nordisk A/S | Medical device and cartridge |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3540678B2 (en) * | 1999-08-25 | 2004-07-07 | 富士通株式会社 | Optical head |
US7102992B1 (en) * | 2000-07-27 | 2006-09-05 | Termstar Corporation | Contact optical head for data storage |
JP3668112B2 (en) * | 2000-09-07 | 2005-07-06 | 富士通株式会社 | Magneto-optical head and method of manufacturing magneto-optical head coil |
US6781926B2 (en) * | 2000-10-10 | 2004-08-24 | Hitachi Maxell, Limited | Magneto-optical head having heat sink layer |
JP3903365B2 (en) * | 2001-03-29 | 2007-04-11 | 株式会社東芝 | Optically assisted magnetic recording head and optically assisted magnetic recording apparatus |
KR20040045473A (en) * | 2001-10-05 | 2004-06-01 | 코닌클리케 필립스 일렉트로닉스 엔.브이. | Method of manufacturing a digital magneto-optical signal write/read head and write/read head manufactured according to the method |
JP2003178498A (en) * | 2001-12-11 | 2003-06-27 | Fujitsu Ltd | Magnetic head and data recording and reproducing device |
US20030198146A1 (en) | 2002-04-18 | 2003-10-23 | Seagate Technology Llc | Heat assisted magnetic recording head with multilayer electromagnetic radiation emission structure |
US7215629B2 (en) * | 2002-06-20 | 2007-05-08 | Seagate Technology Llc | Magnetic recording device for heat assisted magnetic recording |
JP4109255B2 (en) * | 2002-12-24 | 2008-07-02 | 富士通株式会社 | Magneto-optical recording medium and manufacturing method thereof |
WO2005001826A1 (en) * | 2003-06-26 | 2005-01-06 | Fujitsu Limited | Magnetic field generator, magnetooptical information storing system, and magnetooptical information storage device |
WO2005071673A1 (en) * | 2004-01-19 | 2005-08-04 | Koninklijke Philips Electronics N.V. | Method of manufacturing a magneto-optical device |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5402293A (en) * | 1990-12-27 | 1995-03-28 | Sony Electronics Inc. | Magneto-optical head having a thin film coil recessed into a magnetic substrate |
US5544131A (en) * | 1993-05-14 | 1996-08-06 | Commissariat A L'energie Atomique | Magnetic writing head for magneto-optical recording with thick protective coating |
US5831797A (en) * | 1997-07-23 | 1998-11-03 | Seagate Technology, Inc. | Slider with mesa for optical disc data storage system |
US5978320A (en) * | 1997-05-16 | 1999-11-02 | Sony Corporation | Recording/reproducing apparatus for use with a photomagnetic recording medium |
US6130779A (en) * | 1998-07-06 | 2000-10-10 | Read-Rite Corporation | Near field magneto-optical head made using wafer processing techniques |
US6307818B1 (en) * | 1998-06-09 | 2001-10-23 | Seagate Technology Llc | Magneto-optical head with integral mounting of lens holder and coil |
US20030142593A1 (en) * | 2002-01-25 | 2003-07-31 | Fujitsu Limited | Magnetic head provided with moment-reducing contact for data storage medium |
US6618330B1 (en) * | 2000-09-07 | 2003-09-09 | Fujitsu Limited | Magneto-optical head and method of making coil for the same |
US20040027929A1 (en) * | 1999-03-19 | 2004-02-12 | Fujitsu Limited | Optical head and coil assembly used for the same |
US20050105402A1 (en) * | 2003-11-19 | 2005-05-19 | Fujitsu Limited | Magneto-optical head and magneto-optical disk drive |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10255205A (en) * | 1997-03-07 | 1998-09-25 | Canon Inc | Magnetic head for magneto-optical recording, and magneto-optical recording apparatus |
US5886959A (en) | 1997-04-18 | 1999-03-23 | Read-Rite Corporation | Thin-film electro-magnetic coil design for use in a flying magneto-optical head |
JPH10320863A (en) | 1997-05-19 | 1998-12-04 | Sony Corp | Recording and reproducing device |
JPH11120644A (en) * | 1997-10-17 | 1999-04-30 | Sony Corp | Optical element for magneto-optical recording and recording and/or reproducing device |
JPH11162034A (en) * | 1997-11-27 | 1999-06-18 | Sanyo Electric Co Ltd | Magneto-optical head and magneto-optical recording/ reproducing device |
JPH11232718A (en) | 1998-02-18 | 1999-08-27 | Sanyo Electric Co Ltd | Magneto-optical head and magneto-optical recording device |
JP2000076724A (en) | 1998-08-31 | 2000-03-14 | Sanyo Electric Co Ltd | Magneto-optical head device |
JP2001184748A (en) * | 1999-12-22 | 2001-07-06 | Sanyo Electric Co Ltd | Magneto-optical recording thin-film magnetic head |
JP3490951B2 (en) * | 2000-03-17 | 2004-01-26 | 三洋電機株式会社 | Magnetic head for magneto-optical disk and magneto-optical disk recording / reproducing apparatus including the same |
-
2000
- 2000-09-07 JP JP2000271208A patent/JP3668112B2/en not_active Expired - Fee Related
-
2001
- 2001-02-27 US US09/794,369 patent/US6618330B1/en not_active Expired - Fee Related
-
2003
- 2003-07-10 US US10/617,284 patent/US20040141426A1/en not_active Abandoned
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5402293A (en) * | 1990-12-27 | 1995-03-28 | Sony Electronics Inc. | Magneto-optical head having a thin film coil recessed into a magnetic substrate |
US5544131A (en) * | 1993-05-14 | 1996-08-06 | Commissariat A L'energie Atomique | Magnetic writing head for magneto-optical recording with thick protective coating |
US5978320A (en) * | 1997-05-16 | 1999-11-02 | Sony Corporation | Recording/reproducing apparatus for use with a photomagnetic recording medium |
US6064632A (en) * | 1997-05-16 | 2000-05-16 | Sony Corporation | Recording/reproducing apparatus and a magneto-optical recording medium for use therewith |
US5831797A (en) * | 1997-07-23 | 1998-11-03 | Seagate Technology, Inc. | Slider with mesa for optical disc data storage system |
US6307818B1 (en) * | 1998-06-09 | 2001-10-23 | Seagate Technology Llc | Magneto-optical head with integral mounting of lens holder and coil |
US6130779A (en) * | 1998-07-06 | 2000-10-10 | Read-Rite Corporation | Near field magneto-optical head made using wafer processing techniques |
US20040027929A1 (en) * | 1999-03-19 | 2004-02-12 | Fujitsu Limited | Optical head and coil assembly used for the same |
US6618330B1 (en) * | 2000-09-07 | 2003-09-09 | Fujitsu Limited | Magneto-optical head and method of making coil for the same |
US20030142593A1 (en) * | 2002-01-25 | 2003-07-31 | Fujitsu Limited | Magnetic head provided with moment-reducing contact for data storage medium |
US20050105402A1 (en) * | 2003-11-19 | 2005-05-19 | Fujitsu Limited | Magneto-optical head and magneto-optical disk drive |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100012735A1 (en) * | 2000-08-10 | 2010-01-21 | Novo Nordisk A/S | Support for a Cartridge for Transferring an Electronically Readable Item of Information from the Cartridge to an Electronic Circuit |
US7922096B2 (en) | 2000-08-10 | 2011-04-12 | Novo Nordisk A/S | Support for a cartridge for transferring an electronically readable item of information from the cartridge to an electronic circuit |
US7614545B2 (en) * | 2003-03-24 | 2009-11-10 | Novo Nordisk A/S | Electronic marking of a medication cartridge |
US8771238B2 (en) | 2005-05-10 | 2014-07-08 | Novo Nordisk A/S | Injection device comprising an optical sensor |
US9522238B2 (en) | 2005-05-10 | 2016-12-20 | Novo Nordisk A/S | Injection device comprising an optical sensor |
US8197449B2 (en) | 2005-05-10 | 2012-06-12 | Novo Nordisk A/S | Injection device comprising an optical sensor |
US8638108B2 (en) | 2005-09-22 | 2014-01-28 | Novo Nordisk A/S | Device and method for contact free absolute position determination |
US20090088701A1 (en) * | 2006-03-20 | 2009-04-02 | Novo Nordisk A/S | Contact Free Reading of Cartridge Identification Codes |
US8608079B2 (en) | 2006-03-20 | 2013-12-17 | Novo Nordisk A/S | Contact free reading of cartridge identification codes |
US8994382B2 (en) | 2006-04-12 | 2015-03-31 | Novo Nordisk A/S | Absolute position determination of movably mounted member in medication delivery device |
US8049519B2 (en) | 2006-04-26 | 2011-11-01 | Novo Nordisk A/S | Contact free absolute position determination of a moving element in a medication delivery device |
US8348904B2 (en) | 2007-03-21 | 2013-01-08 | Novo Nordisk A/S | Medical delivery system having container recognition and container for use with the medical delivery system |
US20100106100A1 (en) * | 2007-03-21 | 2010-04-29 | Novo Nordisk A/S | Medical delivery system having container recognition and container for use with the medical delivery system |
US20100194537A1 (en) * | 2007-06-09 | 2010-08-05 | Novo Nordisk A/S | Contact free reading of reservoir identification codes |
US9186465B2 (en) | 2008-11-06 | 2015-11-17 | Novo Nordisk A/S | Electronically assisted drug delivery device |
US9950117B2 (en) | 2009-02-13 | 2018-04-24 | Novo Nordisk A/S | Medical device and cartridge |
Also Published As
Publication number | Publication date |
---|---|
JP3668112B2 (en) | 2005-07-06 |
JP2002083453A (en) | 2002-03-22 |
US6618330B1 (en) | 2003-09-09 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6618330B1 (en) | Magneto-optical head and method of making coil for the same | |
US8116034B2 (en) | Thermally assisted magnetic head having main pole arranged between near-field light-generating portions and manufacturing method of same | |
JP4971245B2 (en) | Data storage | |
JP2002523853A (en) | Heating head for data storage system | |
US6671135B2 (en) | Thin film magnetic head recessed partially into substrate and including planarization layers | |
EP1821288B1 (en) | Magnetic head and information storage apparatus | |
US6631099B1 (en) | Magnetic field modulation magnetic head, magneto-optical element, optical pickup device, and optical disk drive, in which first and second magnetic cores are placed on opposite sides of magnetic field generation coil to achieve low power consumption and high efficiency | |
KR100566680B1 (en) | Recording / playback devices and magneto-optical recording media for use with them | |
US5317800A (en) | Method of making an integrated magnetooptical read and write head | |
KR100784396B1 (en) | Method of manufacturing a magnetic head having a planar coil | |
US8351304B2 (en) | Near-field optical head and information recording/reproducing device | |
US6529449B1 (en) | Magneto-optical head involving solid immersion lens with two-layer heat-dispersive coil | |
US6704250B1 (en) | Near-field magneto-optical head having a magnetic sensor | |
US6628604B2 (en) | Magnetic head having a magnetic coil | |
US6757221B1 (en) | Optical head having object lens and patterned coil | |
US20060114756A1 (en) | Light-assisted type magnetic recording head, magnetic recording apparatus and laser-assisted type magnetic recording head manufacturing method | |
US6717905B2 (en) | Optical head and method of making the same | |
JP2004087068A (en) | Compound optical head and optical disk device using the same | |
JP2000215539A (en) | Optical device, recording and/or regenerating device, and manufacture of the optical device | |
KR100601628B1 (en) | Magneto-optical head for near field recording and/or reading and method for manufacturing thereof | |
JP5611590B2 (en) | Near-field optical head and information recording / reproducing apparatus | |
JP2002365406A (en) | Objective lens, optical pickup device and objective lens manufacturing method | |
JP2010519664A (en) | Near-field optical head and information recording / reproducing apparatus | |
JP2006302347A (en) | Optical assistance type magnetic head device, method for manufacturing the same and magnetic recording device | |
WO2005091281A1 (en) | Integrated magneto-optical write/read head |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO PAY ISSUE FEE |