This application is a continuation application of Patent Cooperation Treaty Application No. JP/2012/006220, entitled “Bus Bar for Use in Electric Motor”, filed on Sep. 28, 2012, and the specification and claims thereof are incorporated herein by reference.
Not Applicable.
Not Applicable.
Not Applicable.
1. Field of the Invention (Technical Field)
The present invention relates to a bus bar referred to as a bus line or bus ring and, more particularly, to a bus bar suitable for use as a component part of an electric motor.
2. Description of Related Art
Also referred to as a bus line, a bus bar is used in condition where many terminals are electrically connected to this single bus bar, to eliminate the need of wiring for each of the terminals. This kind of bus bar has been found useful, for example, in a case where it is necessary to connect the terminals of many coils at the same potential as in the case of an electric motor for use in an oil pump configured to supply pressure oil to the power steering of a vehicle.
In particular, the electric motor for use in the vehicle has been demanded to be small or thin so that the vehicle may not be heavier and the electric motor can be housed in a limited housing space; therefore, this kind of bus bar used as a part of the electric motor has also been demanded to be structured or functional so that the electric motor may be small or thin as a whole. Of course, the bus bar required to electrically connect many coil terminals needs to stably provide secure electrical connection for long. Naturally, to use a motor as an industrial product, this kind of bus bar has also been demanded to facilitate motor production and electrical connection as well as a reduction in costs of the motor.
This kind of bus bar has been demanded to meet those requirements, various solutions for the requirements have thus been proposed in Japanese patent publications JP 2011-254629 A (“Patent Document 1”) and JP 4697597 B2 (Patent Document 2).
The “power distribution structure component and manufacturing method thereof” described in Patent Document 1 aims at solving a problem in that “security of insulation of a power distribution member causes an increase in size of the power distribution structure component”; as shown in
The motor described in Patent Document 1 is a so-called 3-phase AC induction motor, which is of one type targeted by the present invention. Therefore, the bus bars shown in Patent Document 1 are used in 4 kinds of U-phase, V-phase, W-phase, and neutral-phase as shown in
The “power distribution member” referred to in Patent Document 1 is considered to be a bus bar targeted by the present invention, which bus bar is of a structure that a “(U-phase) tab 5” to which the terminal of each coil is to be connected must be attached independently or punched out along with the bus bar as shown in
Further, in the case of the “power distribution structure component” described in Patent Document 1, as shown in
The “bus bar and motor” described in Patent Document 2 is “to prevent a connecting part and a circuit board from being broken by preventing the generation of stress at the connecting part between a metal member such as a pin in a connector and the circuit board, in a bus bar of an electric motor”, so that, as described in, for example, paragraph 0027 in Patent Document 2, “in a bus bar 50, each connector pin 513 is roughly J-shaped and has two ends 513a and 513b thereof exposed upward from a resin body 51”.
Therefore, in the case of the “bus bar” described in Patent Document 2 also, like that in Patent Document 1, it is necessary but not so easy to contain the bus bar 50 in the resin by molding while permitting the two ends 513a and 513b to project to the outside.
As recent motor coils, a conductor referred to as a “rectangular wire” has been employed. The “rectangular wire” includes a copper wire having a thickness-to-width ratio of 1:2 to 1:20 and an insulating film formed on a surface thereof and can provide a coil with the number of turns and impedance value to be very small and, therefore, has been used as a motor constituent material actively.
Despite those merits, the high thickness-to-width ratio of 1:2 to 1:20 of the “rectangular wire” makes it easy to bend the rectangular wire in the width direction but difficult to bend the rectangular wire in the thickness direction, of course. If such a rectangular wire is wound as a winding wire into a coil and an end thereof is used as a connection terminal as it is, it may not be connected easily owing to its difficulty in thickness-directional bending in some cases. In other words, the rectangular wire has a limitation in direction of bending in which the rectangular wire can be bent only in a certain direction.
If an electric motor in which the bus bar described above is used as a part of components thereof is employed for use in a vehicle, naturally vibration is directly transmitted to the electric motor from the vehicle. The transmitted vibration may have a bad influence in which, in particular, electrical connection portions of the electric motor may be disconnected or peeled off.
In view of the above, the present invention has been developed to be a part of an electric motor and to enable directly and electrically connecting a coil-side terminal and to manufacture the electric motor easily and inexpensively while stabilizing the relevant electrical connection portions always to inhibit occurrence of the problems of disconnection and peel-off.
That is, it is a first object of the invention to provide a bus bar that can be manufactured easily as a part of an electric motor and, as a result, enables manufacturing the electric motor also easily and inexpensively.
It is a second object of the invention, in addition to the first object to be achieved, to provide a bus bar that enables directly and electrically connecting a coil-side terminal and manufacturing an electric motor easily and inexpensively while stabilizing the relevant electrical connection portions always to inhibit occurrence of problems of disconnection and peel-off.
Further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating one or more preferred embodiments of the invention and are not to be construed as limiting the invention. In the drawings:
Means employed in the present invention to solve the problems will be described as follows by using the same reference numerals and symbols as those used in the later-described best mode: “a bus bar 10 for use in an electric motor configured to supply power to a plurality of coils 20 of the electric motor and/or ground the coils 20 in assemblage, in which a plurality of folded portions 12 each of which includes 3 or a larger odd number of overlapping portions 12a are formed on a conductor material 11 having a predetermined length so that at least a terminal 21 of each of the coils 20 can be electrically and directly fixed to a predetermined position of each of the folded portions 12”.
That is, in the case shown in
Further, in the case shown in
Of course, the bus bar 10 shown in
As shown in
Each of the folded portion 12 includes a plurality of overlapping portions 12a formed by repeatedly folding back the conductor material 11 at a position thereof, as shown in
Accordingly, as shown in
The fact that the overlapping portions 12a can each be elastically deformed means that the overlapping portions 12a where the terminals 21 of the coils 20 are not fixed to each other absorb vibrations received from, for example, a vehicle and, after absorption, immediately recover to their original positions. Therefore, the folded portions 12 itself of the bus bar 10 can each exert an important “vibration absorbing function” for preventing disconnection and peel-off from occurring at the electric connection portions of the terminals 21 of the coils 20.
In the bus bar 10 shown in
Further, the conductor material 11 is “bare” without having the later-described insulating film 11a, so that even if the overlapping portions 12a overlap to come in contact with each other at the folded portion 12, the bus bar 10 does not short-circuit. This is because the bus bar 10 is energized everywhere thereon to produce the same potential at the folded portions 12.
Of course, it is only necessary to form at least the 3 overlapping portions 12a of the folded portion 12 from the long conductor material 11 in a length direction thereof, that is, the forward traveling first overlapping portion 12a, the backward traveling next overlapping portion 12a, and the originally-directional traveling overlapping portion 12a; therefore, the conductor material 11 can be mechanically easily bent in the length direction thereof, so that the bus bar 10 can be manufactured simply and inexpensively.
The terminals 21 of the coils 20 are electrically connected to the bus bar 10 formed as described above by making them abut against any one of the overlapping portions 12a of the folded portion 12, or inserting them into the insertion space formed between the 2 overlapping portions 12a, so that they may undergo “spot welding”, or make them undergo “musing caulking” (process to heat partially with a large current for pressing). By conducting such treatment, the terminals 21 of the coils 20 can be directly and electrically connected to the bus bar 10 without requiring a “tab 5” such as that shown in
Consequently, the bus bar 10 eliminates the need of forming a tab on the terminal 21 of each coil 20 so that the terminals 21 of the coils 20 can be directly and electrically connected to the bus bar 10, overall enabling manufacturing an electric motor easily and inexpensively. Of course, if used in a 3-phase electric motor, the plurality of (4, for example) bus bars 10 are arranged in the same plane in a manner that they may not come in contact with each other as in the case of the conventional technology example shown in
Further, the thickness of the bus bar 10 orthogonal to torus thereof is basically set equal to the thickness or width of the conductor material 11 of this bus bar 10 as shown in
Therefore, the bus bar 10 according to the first aspect of the present invention can be easily manufactured as a part of the electric motor, to resultantly enable the manufacturing of the electric motor also easily and inexpensively.
To solve the problems, means employed by an invention according to a second aspect of the present invention is the bus bar 10 for use in the electric motor according to the first aspect of the present invention, in which “the insertion space 12b in which the terminal 21 of the coil 20 can be inserted is formed in at least one of the odd number of overlapping portions 12a”.
On the bus bar 10 according to the second aspect of the present invention, as shown in
The insertion space 12b can be easily formed by forming a portion corresponding to the insertion space 12b at a portion of a mold used to bend and form each of the overlapping portions 12a of the folded portions 12, without using a large-scale technology in particular.
Therefore, in addition to the same functions as those exerted by the first aspect of the present invention, the bus bar 10 of the second aspect of the present invention has a function to enable inserting the terminal 21 of the coil 20 into the insertion space 12b, thereby further facilitating work of connecting the terminals 21 of the coils 20 to each of the bus bars 10.
To solve the problems, means employed by an invention according to a third aspect of the present invention is the bus bar 10 for use in the electric motor according to the first or second aspect of the present invention, in which “at least one twisted portion 13 is formed on the conductor material 11 between the folded portions 12 and an opening direction of the insertion space in one of the two folded portions 12 adjacent to this twisted portion 13 on both sides is changed with respect to that of the insertion space in the other folded portion 12 adjacent to this twisted portion 13”.
The terminal 21 of each coil 20, which is pulled out toward the bus bar 10 as shown in
Of course, the twisting angle of each of the twisted portions 13 is selected appropriately; however, naturally it is not 180° or more because the twisted portion 13 is used to change the direction of the insertion space in order to facilitate insertion of the terminal 21 into the insertion space in each folded portion 12.
Therefore, besides almost the same functions as those of the first or second aspect of the present invention, the bus bar 10 of the third aspect of the present invention has a function to facilitate insertion of each terminal 21 by changing the directions of the insertion spaces on the two sides of the twisted portion 13 by having the twisted portion 13 formed on the conductor material 11.
To solve the problems, means employed by an invention according to a fourth aspect of the present invention is the bus bar 10 for use in the electric motor according to any of the first to third aspects of the present invention, in which “the conductor material 11 is a flat material having a width-to-thickness ratio of 2:1 to 20:1 and each of the overlapping portions 12a is given by folding this flat material at a width-directional kinked line thereof”.
That is, the bus bar 10 of the fourth aspect of the present invention is overall formed using the conductor material 11 made of the flat material such as that shown in
The flat material such as that shown in
The flat material needs to have the width-to-thickness ratio of 2:1 to 20:1 because if the ratio is less than 2:1, this material is like a wire rod and does not have sufficient merits as a flat material. If the ratio is larger than 20:1, this material is like a flat plate and needs to have a larger sized processing machine in order to cut off excess thereof and form the folded portions 12 and does not have sufficient merits as a flat material in this case either.
By forming the bus bar 10 overall by using the conductor material 11 that is such a flat material, it becomes easy to bend the bus bar 10 in the width direction, that is, form the folded portions 12 or form the bus bar 10 in an annular shape. In particular, the overlapping portions 12a of each folded portion 12 can be easily folded at a width-directional kinked line of the flat material to form each folded portion 12 very stably. In other words, the kinked line resulting from folding of the flat material faces a direction in which the flat material can be bent most easily, that is, a direction orthogonal to the length direction thereof.
If the flat material is folded at a width-directional kinked line, that is, a kinked line orthogonal to the length direction thereof as described above, the overlapping portions 12a of the folded portion 12 overlap with each other literally completely as shown in
Therefore, besides almost the same functions as those of the first to third aspects of the present invention, the bus bar 10 of the fourth aspect of the present invention keeps its width unchanged at all even after the processing of the folded portions 12, thereby facilitating designing of the insulating holder 14 and the mold resin 15.
To solve the problems, means employed by an invention according to a fifth aspect of the present invention is the bus bar 10 for use in the electric motor according to any of the first to fourth aspects of the present invention, in which “the conductor material 11 is a flat block on a surface of which the insulating film 11a is formed”.
That is, as shown in
Such a conductor material 11 that is the flat block on the surface of which the insulating film 11a is formed is commercially available generally and can make up a coil with very few turns and low impedance and, therefore, has been actively used as a motor constituent material. Like the flat material according to the fourth aspect of the present invention, the conductive material 11 that is the flat block has a demerit of extreme difficulty in thickness-directional bending unlike the wire rod such as that shown in
Of course, the bus bar 10, which is formed using this conductor material 11 that is the flat block, has the insulating film 11a on the surface thereof and, therefore, needs not take into consideration possible subsequent short-circuiting when the bus bar 10 is incorporated into the holder groove 14a in the insulating holder 14 shown in
Further, if the insulating film 11a is formed with a thin film such as a so-called enamel material (as in the case of commercially available rectangular wires), there occurs no problem when electrically and directly connecting the terminals 21 of the coils 20 to each folded portion 12 by “spot welding” or “musing caulking”, because the insulating film 11a is removed by heat.
Further, the conductor material 11 having the insulating film 11a formed on the flat block is generally inexpensive and commercially available, while the overlapping portions 12a of each folded portion 12 can be formed by folding without projecting the overlapping portions 12a in the width direction of the conductor material 11 as in the case of the fourth aspect of the present invention, so that it is possible to manufacture the bus bar 10 easily and inexpensively.
Therefore, besides almost the same functions as those of the first to fourth aspects of the present invention, the bus bar 10 according to the fifth aspect of the present invention itself has insulation properties due to the insulating film 11a and can be
To solve the problems, means employed by an invention according to a sixth aspect of the present invention is the bus bar 10 for use in the electric motor according to any of the first to fifth aspects of the present invention, in which “the conductor material 11 on which the folded portion 12 is formed is inserted into an insulating tube 16”.
That is, the bus bar 10 of the sixth aspect of the present invention is given by inserting the conductor material 11 on which the folded portion 12 is formed, into the insulating tube 16 as shown in
The insulating tube 16 literally has insulation properties and is configured to envelop the internal conductor material 11 while securing insulation between the conductor material 11 and the peripheral parts. Of course, a hole for insertion of the terminal 21 can be formed in the insulating tube 16 by a physical impact such as heat so that the terminal 21 can be easily inserted to the folded portion 12 through this hole. The insulating tube 16 in the later-described embodiment shrinks as being heated and can envelop the conductor material 11 having the folded portion 12 formed thereon with almost no space therebetween so that the terminal 21 and the folded portion 12 can be electrically connected to each other from the outside, as shown in
In an example shown in
The conductor material 11 enveloped in such an insulating tube 16 is securely insulated electrically from the peripheral parts by the insulating tube 16, so that the need of holding the conductor material 11 by the insulating holder 14 is eliminated, that is, the insulating holder 14 itself is rendered unnecessary. Accordingly, the bus bar 10 and the terminals 21 can be interconnected directly as shown in
Of course, as described above, the insulating tube 16 not only secures electrical insulation from the periphery but also protects the conductor material 11 from oxygen in the ambient air as well as humidity and water, which are responsible for rust, thereby enhancing decay durability of the bus bar 10.
Therefore, besides almost the same functions as those of the first to fifth aspects of the present invention, the bus bar 10 of the sixth aspect of the present invention has a function to protect the conductor material 11 by using the insulating tube 16 and, therefore, is more improved in decay durability.
To solve the problems, means employed by an invention according to a seventh aspect of the present invention is the bus bar 10 for use in the electric motor according to any of the first to sixth aspects of the present invention, in which “the bus bar 10 comprises one set of 4 kinds of bus bars: a U-phase bus bar, a V-phase bus bar, a W-phase bus bar, and a neutral-phase bus bar”.
The bus bar 10 of the seventh aspect of the present invention is suitable for use in a case where the electric motor is a 3-phase AC electric motor, comprising one set of 4 kinds of bus bars: a U-phase bus bar, a V-phase bus bar, a W-phase bus bar, and a neutral-phase bus bar. As shown in
In the 3-phase AC electric motor having such U-phase, V-phase, W-phase, and neutral phase, the U-phase bus bar, the V-phase bus bar, and W-phase bus bar are supplied with AC power levels having changed “phases” and connected to the ground by the neutral-phase bus bar.
The bus bar 10 comprising one set of the 4 kinds of bus bars of the U-phase bus bar, the V-phase bus bar, the W-phase bus bar, and the neutral-phase bus bar has all the functions described in the inventions according to the first to fifth aspects of the present invention and therefore, of course, can itself be manufactured easily and enables manufacturing the 3-phase AC electric motor easily and inexpensively by using the bus bar 10 itself as a part of this motor.
Therefore, besides almost the same functions as those of the inventions according to the first to sixth aspects of the present invention, the bus bar 10 according to the seventh aspect of the present invention enables manufacturing the 3-phase AC electric motor easily and inexpensively.
As described above, a main feature of the present invention in structure is “a bus bar 10 configured to supply power to the plurality of coils 20 of an electric motor and/or ground the coils 20 in assemblage, in which a plurality of folded portions 12 each of which includes 3 or a larger odd number of overlapping portions 12a are formed on a conductor material 11 having a predetermined length so that at least a terminal 21 of each of the coils 20 can be electrically and directly fixed to a predetermined position of each of the folded portions 12”, so that it is possible to provide the bus bar 10 that can itself be manufactured easily as a part of the electric motor and enables manufacturing the electric motor also easily and inexpensively.
Further, the present invention enables electrically and directly connecting at least the terminal 21 of each of the coils 20 to a predetermined position of each of the folded portions 12 so that the terminal 21 on the side of the coil 20 can be directly and electrically connected and can provide the bus bar 10 that enables manufacturing an electric motor easily and inexpensively while stabilizing the relevant electrical connection portions always, to inhibit occurrence of problems of disconnection and peel-off.
Referring now to the figures,
The electric motors shown in
Such a 3-phase AC electric motor uses various numbers of the coils 20, which numbers are, of course, a multiple of 3 because naturally the coil is necessary for each of the U-phase, the V-phase, and the W-phase.
A description will be given of characteristics of the bus bar 10 according to the present invention for each of Embodiment 1 shown in
As to Embodiment 1, a bus bar 10 according to Embodiment 1 shown in
In the bus bar 10 according to Embodiment 1, the folded portion 12 includes a plurality of overlapping portions 12a formed by repeatedly folding back the conductor material 11 at a position thereof, as shown in
That is, in a case shown in
Accordingly, as shown in
The fact that the overlapping portions 12a of the folded portion 12 can each be elastically deformed means that the overlapping portions 12a where the terminals 21 of the coils 20 are not fixed to each other absorb vibrations received from, for example, a vehicle and, after absorption, immediately recover to their original positions. Therefore, the folded portions 12 itself of the bus bar 10 can each exert a “vibration absorbing function” for preventing disconnection and peel-off from occurring at the electric connection portions of the terminals 21 of the coils 20.
In the bus bar 10 according to Embodiment 1 shown in
The conductor material 11 used to sequentially form such bus bars 10 is a wire rod or elongated round wire rod shown in
When the bus bar 10 is manufactured using the conductor material 11 having the insulating film 11a, despite the tendency of the conductor material 11 having the insulating film 11a to be expensive, of course, this bus bar 10 exerts great effects in all phases of its manufacture and assembly as well as completion and use of an electric motor owing to cooperation of insulation properties of the insulating film 11a itself and those of the insulating holder 14 or the mold resin 15.
Because the bus bar 10 of Embodiment 2 has employed the flat material shown in
Such a flat material or flat block needs to have a width-to-thickness ratio of 2:1 to 20:1 because if this ratio is less than 2:1, it is like a wire rod and does not have sufficient merits as a flat material. If the ratio is larger than 20:1, such a flat material or flat block is like a flat plate and needs to have a larger sized processing machine in order to cut off excess thereof and form the folded portions 12 and does not have sufficient merits as a flat material in this case either.
By forming the bus bar 10 overall by using the conductor material 11 that is such a flat material or flat block, it becomes easy to bend the bus bar 10 in a width direction thereof, that is, form the folded portions 12 or form the bus bar 10 in an annular shape. In particular, the overlapping portions 12a of each folded portion 12 can be easily folded at a width-directional kinked line of the conductor material 11 to form each folded portion 12 very stably. In the case of folding the flat material or flat block in the width direction and a length direction thereof, the width-directional kinked line does not obliquely face the width direction but naturally faces a direction parallel to the width direction, that is, faces a direction orthogonal to the length direction. In other words, when the conductor material 11 is folded, the resultant kinked line faces a direction in which the conductor material 11 can be bent most easily, that is, a direction orthogonal to the length direction.
When the conductor material 11 is folded at the width-directional kinked line thereof, that is, a kinked line orthogonal to the length direction thereof as described above, the overlapping portions 12a of the folded portion 12 overlap with each other literally completely as shown in
The second respect of the bus bar 10 according to Embodiment 2 different from that according to Embodiment 1 is that as shown in
The insertion space 12b can be easily formed by forming a portion corresponding to the insertion space 12b at a portion of a mold used to bend and form each of the overlapping portions 12a of the folded portion 12, without using a large-scale technology in particular. The insertion space 12b of the embodiment shown in
A bus bar 10 according to Embodiment 3 shown in
Of course, the twisting angle of each of the twisted portions 13 is selected appropriately; however, naturally the angle is not 180° or more because the twisted portion 13 is used to change the direction of the insertion space in order to facilitate insertion of the terminal 21 into the insertion space in each folded portion 12. Of course, the angle may be large enough if it is 90° at the maximum because the insertion space in each folded portion 12 is open at both ends. In view of the above, the twisting angle of each twisted portion 13 is determined in a range between 20° and 80° in many cases.
By forming the twisted portion 13, the opening direction of the insertion space in one of the two folded portions 12 adjacent to this twisted portion 13 on both sides thereof is changed with respect to that of the insertion space in the other folded portion 12 adjacent to this twisted portion 13 by an angle at which the portion is twisted. The directions of the insertion spaces in the two folded portions 12 adjacent to the one twisted portion 13 on both the sides thereof are changed from each other in order to facilitate work of inserting the terminals 21 of coils 20 in the following cases.
The terminal 21 of each of the coils 20, which is pulled out toward the bus bar 10 as shown in
A bus bar 10 according to Embodiment 4 shown in
The insulating tube 16 literally has insulation properties and is configured to envelop the internal conductor material 11 while securing insulation between the conductor material 11 and the peripheral parts. Of course, a hole for insertion of the terminal 21 can be formed in the insulating tube 16 by a physical impact such as heat so that the terminal 21 can be easily inserted to the folded portion 12 through this hole. Further, the insulating tube 16 shrinks as being heated and can envelop the conductor material 11 having the folded portion 12 formed thereon with almost no space in between so that the terminal 21 and the folded portion 12 can be electrically connected to each other from the outside, as shown in
As shown in
The conductor material 11 enveloped in such an insulating tube 16 is securely insulated electrically from the peripheral parts by the insulating tube 16, so that the need of holding the conductor material 11 by the insulating holder 14 is eliminated, that is, the insulating holder 14 itself is rendered unnecessary. Accordingly, the bus bar 10 and the terminals 21 can be interconnected directly as shown in
Of course, the insulating tube 16 not only secures electrical insulation from the periphery but also protects the conductor material 11 from oxygen in the ambient air as well as humidity and water, which are responsible for rust, thereby enhancing decay durability of the bus bar 10.
In the bus bar 10 according to the present invention, the folded portion 12 that replaces a “tab” separately formed conventionally is formed by folding the conductor material 11 itself, so that this bus bar can be applied as a “bus line” in the case of, for example, electrically interconnecting various electric apparatuses at the same potential. Besides, the bus bar 10 can be formed by sequentially folding the conductor material 11 made of a round wire rod, flat material, or flat block and, therefore, can be mounted in a very small space and inexpensively. Accordingly, the bus bar has large applicability not only in the electric motors but also in other fields of, for example, manufacturing electric appliances such as refrigerators and washing machines.
The following reference numerals are used in this description:
10: Bus bar
11: Conductor material
11
a: Insulating film
12: Folded portion
12
a: Overlapping portion
12
b: Insertion space
13: Twisted portion
14: Insulating holder
14
a: Hold groove
15: Mold resin
16: Insulating tube
16
a: Potting resin
20: Coil
21: Terminal
Note that in the specification and claims, “about” or “approximately” means within twenty percent (20%) of the numerical amount cited. All computer software disclosed herein may be embodied on any non-transitory computer-readable medium (including combinations of mediums), including without limitation CD-ROMs, DVD-ROMs, hard drives (local or network storage device), USB keys, other removable drives, ROM, and firmware.
Although the invention has been described in detail with particular reference to these preferred embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. The entire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference.
Number | Date | Country | |
---|---|---|---|
Parent | PCT/JP2012/006220 | Sep 2012 | US |
Child | 14026683 | US |