The present application claims priority to Japanese Patent Application JP 2008-319215 filed with the Japanese Patent Office on Dec. 16, 2008, the entire content of which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an inductor module and a circuit module, and more particularly to an inductor module provided with an inductor including a plurality of coil sections. The present invention relates also to a circuit module including a plurality of such inductors.
2. Description of the Related Art
A television tuner requires many components such as inductors, and there is a case that it is difficult to reduce the size of the apparatus.
Developed as the television tuner is a silicon tuner including a circuit module such that analog high-frequency circuits are integrated in a semiconductor such as Si and SiGe. The silicon tuner uses an inductor module such that a device such as an inductor is incorporated in a printed wiring board.
For example, a flat coil is used as the inductor (see Japanese Patent Laid-open Nos. 2004-6515 and 2008-41833, for example).
A television tuner is required to support a wide frequency band from tens of MHz to 1 GHz. Accordingly, there is a case that a plurality of inductors having different inductance values are required.
To meet this requirement, there are provided a plurality of kinds of inductors different in the number of layers of flat coils or in the number of turns of coils, for example. In such a case, the footprint of the inductors is therefore increased and there is a case that it is difficult to reduce the size of the inductor module, causing a possible increase in cost.
There is accordingly a need for the present invention to provide an inductor module and a circuit module which can be reduced in size.
In accordance with an embodiment of the present invention, there is provided an inductor module including a coil section provided with an input terminal and an output terminal. At least one of the input terminal and the output terminal is composed of a plurality of terminals. The input terminal and the output terminal are connected at different positions. The connection of the plurality of terminals constituting the input terminal or the output terminal is switched so as to change the combination of the input terminal and the output terminal, thereby obtaining different inductance values.
In accordance with another embodiment of the present invention, there is provided a circuit module including an inductor having a coil section provided with an input terminal and an output terminal. At least one of the input terminal and the output terminal is composed of a plurality of terminals. The input terminal and the output terminal are connected at different positions. The connection of the plurality of terminals constituting the input terminal or the output terminal is switched so as to change the combination of the input terminal and the output terminal, thereby obtaining different inductance values.
According to the present embodiment, the coil section includes the input terminal and the output terminal, wherein at least one of the input terminal and the output terminal is composed of a plurality of terminals. The connection of the plural terminals constituting the input terminal or the output terminal is switched so as to change the combination of the input terminal and the output terminal. Accordingly, the path of a current to be passed through the coil section from the input terminal to the output terminal is changed to thereby obtain different inductance values in the inductor.
According to the present embodiment, it is possible to provide an inductor module and a circuit module which can be reduced in size.
Other objects and features of the invention will be more fully understood from the following detailed description and appended claims when taken with the accompanying drawings.
Some preferred embodiments of the present invention will now be described in detail with reference to the attached drawings. The preferred embodiments will be described in the following order.
1. First Preferred Embodiment (Inductor module having two output terminals)
2. Second Preferred Embodiment (Inductor module having three output terminals)
3. Third Preferred Embodiment (Inductor module having a magnetic insulating layer)
4. Fourth Preferred Embodiment (Inductor module having a solenoid coil)
The circuit module 1 is used in a television tuner, for example. As shown in
As shown in
As described later in detail, the first inductor 101 is configured in such a manner that when a current is passed through the first inductor 101, the connection of the input terminal 151 and the plural output terminals 161 and 162 is changed in combination to thereby vary the value of an inductance. More specifically, the connection of the plural output terminals 161 and 162 is switched so that a current is passed either between the input terminal 151 and the first output terminal 161 or between the input terminal 151 and the second output terminal 162, thereby varying the inductance value.
The components of the first inductor 101 will now be described more specifically.
As shown in
The first to fourth coil patterns 111, 112, 113, and 114 constituting the coil section 110 are layered in this order from the lower side so as to be spaced apart from each other. Each of the first to fourth coil patterns 111 to 114 is formed of a conductive material such as metal.
As shown in
Further, as shown in
As shown in
More specifically, as shown in
As shown in
As shown in
On the other hand, as shown in
As shown in
More specifically, as shown in
As shown in
The second coil pattern 112 is layered over the first coil pattern 111 in the condition where the insulating layer Z2 is interposed therebetween. That is, the lower surface of the second coil pattern 112 is opposed to the upper surface of the first coil pattern 111.
As shown in
On the other hand, as shown in
As shown in
More specifically, as shown in
As shown in
The third coil pattern 113 is layered over the second coil pattern 112 in the condition where the insulating layer Z3 is interposed therebetween. That is, the lower surface of the third coil pattern 113 is opposed to the upper surface of the second coil pattern 112.
As shown in
On the other hand, as shown in
As shown in
More specifically, as shown in
As shown in
The fourth coil pattern 114 is layered over the third coil pattern 113 in the condition where the insulating layer Z4 is interposed therebetween. That is, the lower surface of the fourth coil pattern 114 is opposed to the upper surface of the third coil pattern 113.
As shown in
On the other hand, the second output terminal 162 is provided on the upper surface of the other end 114f of the fourth coil pattern 114.
As shown in
More specifically, the upper end surface of the input terminal 151 is connected to the lower surface of the one end 111s of the first coil pattern 111. Further, the input terminal 151 extends vertically downward from the lower surface of the one end 111s of the first coil pattern 111.
As shown in
More specifically, the upper end surface of the first output terminal 161 is connected to the lower surface of the other end 111f of the first coil pattern 111. Further, the first output terminal 161 extends vertically downward from the lower surface of the other end 111f of the first coil pattern 111.
The second output terminal 162 is provided on the upper surface of the fourth coil pattern 114 opposite to the first to third coil patterns 111, 112, and 113. The second output terminal 162 is formed of a conductive material such as metal like the input terminal 151.
More specifically, the lower end surface of the second output terminal 162 is connected to the upper surface of the other end 114f of the fourth coil pattern 114. Further, the second output terminal 162 extends vertically upward from the upper surface of the other end 114f of the fourth coil pattern 114.
The operation of the first inductor 101 will now be described.
In the first inductor 101, the connection of the first and second output terminals 161 and 162 is switched so that a current is output from one of the first and second output terminals 161 and 162. More specifically, the connection between one of the first and second output terminals 161 and 162 and output wiring (not shown) through which an output current is passed is switched by a switching device (not shown).
Accordingly, in passing a current through the first inductor 101, either the combination of the input terminal 151 and the first output terminal 161 or the combination of the input terminal 151 and the second output terminal 162 is selected, so that the inductance value in the first inductor 101 is variable according to this selection.
More specifically, in the case that the connection is switched so that a current is input from the input terminal 151 and output from the first output terminal 161, the current is passed through the first coil pattern 111.
As shown in
That is, the current is passed through only the first coil pattern 111 and no current is passed through the second to fourth coil patterns 112, 113, and 114.
In the case that the connection is switched so that a current is input from the input terminal 151 and output from the second output terminal 162, the current is passed not only through the first coil pattern 111, but also through the second to fourth coil patterns 112, 113, and 114.
As shown in
Thereafter, the current input to the one end 112s of the second coil pattern 112 is passed clockwise toward the other end 112f of the second coil pattern 112 and next input to the one end 113s of the third coil pattern 113. Also in the second coil pattern 112, the current input to the one end 112s is passed clockwise through the spiral winding to the other end 112f.
Thereafter, the current input to the one end 113s of the third coil pattern 113 is passed clockwise toward the other end 113f of the third coil pattern 113 and next input to the one end 114s of the fourth coil pattern 114. Also in the third coil pattern 113, the current input to the one end 113s is passed clockwise through the spiral winding to the other end 113f.
Thereafter, the current input to the one end 114s of the fourth coil pattern 114 is passed clockwise toward the other end 114f of the fourth coil pattern 114. Also in the fourth coil pattern 114, the current input to the one end 114s is passed clockwise through the spiral winding to the other end 114f.
Thereafter, the current input to the other end 114f of the fourth coil pattern 114 is output from the second output terminal 162 provided at the other end 114f.
In the former case that the current is output from the first output terminal 161 in the first inductor 101, a low, first inductance value is obtained.
In the latter case that the current is output from the second output terminal 162, a second inductance value higher than the first inductance value is obtained. That is, in the latter case, the current is passed through the first to fourth coil patterns 111 to 114 in the same direction (clockwise direction) and the number of turns of the coil passing the current is greater than that in the former case. As a result, the inductance value in the latter case is higher than that in the former case.
As described above, either the first output terminal 161 or the second output terminal 162 is connected to the output wiring. Accordingly, there is no possibility that devices having different inductance values are operated at the same time.
In the first inductor 101, two different inductance values can be selectively obtained, that is, either the first inductance value or the second inductance value higher than the first inductance value can be selected.
The positions of the first and second output terminals 161 and 162 in the first inductor 101 are merely illustrative and may be changed.
For example, the first output terminal 161 may be provided at the upper surface of the one end 114s of the fourth coil pattern 114. In this case, when a current is output from the first output terminal 161, the current is passed through the first to third coil patterns 111, 112, and 113. Accordingly, the inductance value in this case becomes higher than that in the above case where the first output terminal 161 is provided on the lower surface of the other end 111f of the first coil pattern 111.
The second to fifth inductors 201, 301, 401, and 501 are configured so as to provide inductance values different from the inductance value in the first inductor 101. Further, the inductance values in the second to fifth inductors 201 to 501 are fixed values unlike the variable inductance value in the first inductor 101.
However, each of the second to fifth inductors 201 to 501 may provide a plurality of different inductance values as in the first inductor 101.
There will now be described a major part of a manufacturing method for the first inductor 101.
Although not shown, the second to fifth inductors 201 to 501 are also similarly manufactured by the manufacturing method for the first inductor 101.
As shown in
First, a laminated sheet (not shown) formed by laminating copper foils (not shown) on both sides of the insulating layer Z3 is prepared. The insulating layer Z3 is provided by an insulating resin substrate.
The copper foil laminated on one side of the insulating layer Z3 is patterned to form the second coil pattern 112.
More specifically, as shown in
Similarly, the copper foil laminated on the other side of the insulating layer Z3 is patterned to form the third coil pattern 113.
More specifically, as shown in
As shown in
First, a through hole (not shown) is formed through the insulating layer Z3 by laser processing. For example, this laser processing is performed by using a carbon dioxide gas laser.
Thereafter, this through hole is filled with a conductive material such as metal to thereby form the blind via hole C2. For example, the filling of the through hole is performed by plating.
More specifically, the blind via hole C2 is formed at a position corresponding to the other end 112f of the second coil pattern 112 and the one end 113s of the third coil pattern 113.
Accordingly, the other end 112f of the second coil pattern 112 and the one end 113s of the third coil pattern 113 are electrically connected by the blind via hole C2.
As shown in
First, the insulating layers Z2 and Z4 are formed on both sides of the insulating layer Z3 on which the second coil pattern 112 and the third coil pattern 113 have already been formed. That is, the insulating layer Z2 is formed so as to cover the second coil pattern 112, and the insulating layer Z4 is formed so as to cover the third coil pattern 113. For example, the insulating layers Z2 and Z4 are formed by laminating resin-containing insulating prepreg films on both sides of the insulating layer Z3.
Thereafter, a copper foil (not shown) is laminated on one side (exposed surface) of the insulating layer Z2 and next patterned to form the first coil pattern 111.
More specifically, as shown in
Similarly, a copper foil (not shown) is laminated on one side (exposed surface) of the insulating layer Z4 and next patterned to form the fourth coil pattern 114.
More specifically, as shown in
As shown in
First, a through hole (not shown) is formed through the insulating layer Z2 by laser processing. Thereafter, this through hole is filled with a conductive material such as metal to thereby form the blind via hole C1.
More specifically, the blind via hole C1 is formed at a position corresponding to the other end 111f of the first coil pattern 111 and the one end 112s of the second coil pattern 112.
Accordingly, the other end 111f of the first coil pattern 111 and the one end 112s of the second coil pattern 112 are electrically connected by the blind via hole C1.
Similarly, a through hole (not shown) is formed through the insulating layer Z4 by laser processing. Thereafter, this through hole is filled with a conductive material such as metal to thereby form the blind via hole C3.
More specifically, the blind via hole C3 is formed at a position corresponding to the other end 113f of the third coil pattern 113 and the one end 114s of the fourth coil pattern 114.
Accordingly, the other end 113f of the third coil pattern 113 and the one end 114s of the fourth coil pattern 114 are electrically connected by the blind via hole C3.
As shown in
First, the insulating layer Z1 is formed on one side (exposed surface) of the insulating layer Z2, and the insulating layer Z5 is formed on one side (exposed surface) of the insulating layer Z4. That is, the insulating layer Z1 is formed so as to cover the first coil pattern 111, and the insulating layer Z5 is formed so as to cover the fourth coil pattern 114. For example, the insulating layer Z1 is formed by laminating a resin-containing insulating prepreg film on one side (exposed surface) of the insulating layer Z2. Similarly, the insulating layer Z5 is formed by laminating a resin-containing insulating prepreg film on one side (exposed surface) of the insulating layer Z4.
Thereafter, two through holes (not shown) are formed through the insulating layer Z1 by laser processing. These through holes are next filled with a conductive material such as metal to thereby form the input terminal 151 and the first output terminal 161.
More specifically, the input terminal 151 is formed at a position corresponding to the one end 111s of the first coil pattern 111, and the first output terminal 161 is formed at a position corresponding to the other end 111f of the first coil pattern 111.
Similarly, a through hole (not shown) is formed through the insulating layer Z5 by laser processing. This through hole is next filled with a conductive material such as metal to thereby form the second output terminal 162.
More specifically, the second output terminal 162 is formed at a position corresponding to the other end 114f of the fourth coil pattern 114.
Thus, the first inductor 101 is completed.
The above-mentioned steps of the manufacturing method for the first inductor 101 are merely illustrative and various other methods used in the manufacture of a printed wiring board may be applied.
In this preferred embodiment, the coil section 110 includes three terminals, i.e., the input terminal 151 and the first and second output terminals 161 and 162, which are connected at different positions. The connection to one of the plural output terminals 161 and 162 is selected so as to change the combination of the input terminal 151 and the plural output terminals 161 and 162. Accordingly, the inductance value in the first inductor 101 can be varied.
Accordingly, it is unnecessary to provide a plurality of inductors for supporting a plurality of different inductance values, so that the footprint of an inductor can be reduced. As a result, the module including the inductor in this preferred embodiment can be reduced in size.
Further, in this preferred embodiment, each of the first to fourth coil patterns 111 to 114 is a flat coil and these coil patterns 111 to 114 are layered so that the respective coil surfaces are opposed to each other. The input terminal 151 is provided on the lower surface of the one end 111s of the first coil pattern 111 forming the lowermost layer. Further, the first output terminal 161 is provided on the lower surface of the other end 111f of the first coil pattern 111 forming the lowermost layer. Further, the second output terminal 162 is provided on the upper surface of the other end 114f of the fourth coil pattern 114 forming the uppermost layer.
Accordingly, the footprint of the inductor can be further reduced, so that the module including the inductor can be easily reduced in size.
A second preferred embodiment of the present invention will now be described.
As shown in
As shown in
The pad portion 114p is formed of a conductive material such as metal like the fourth coil pattern 114. The pad portion 114p is formed in the step of patterning a conductive film to form the fourth coil pattern 114.
A blind via hole C3b is provided on the lower surface of the pad portion 114p. The blind via hole C3b is formed by using a conductive material such as metal, and extends downward from the lower surface of the pad portion 114p. Further, the lower end surface of the blind via hole C3b is connected to the upper surface of the one end 113s of the third coil pattern 113.
That is, the third output terminal 163 is electrically connected through the pad portion 114p and the blind via hole C3b to the one end 113s of the third coil pattern 113.
The operation of the first inductor 101b will now be described.
In this preferred embodiment, the connection of the first, second, and third output terminals 161, 162, and 163 is switched so that a current is output from one of these output terminals 161 to 163. More specifically, the connection between one of the first to third output terminals 161 to 163 and output wiring (not shown) through which an output current is passed is switched by a switching device (not shown).
Accordingly, in passing a current through the first inductor 101b, one of the combination of the input terminal 151 and the first output terminal 161, the combination of the input terminal 151 and the second output terminal 162, and the combination of the input terminal 151 and the third output terminal 163 is selected, so that three different inductance values can be obtained in the first inductor 101b.
More specifically, in the case that the connection is switched so that a current is input from the input terminal 151 and output from the third output terminal 163, the current is passed through the first and second coil patterns 111 and 112.
The current input to the one end 111s of the first coil pattern 111 is passed through the spiral winding of the first coil pattern 111, the other end 111f of the first coil pattern 111, the blind via hole C1, the one end 112s of the second coil pattern 112, the spiral winding of the second coil pattern 112, the other end 112f of the second coil pattern 112, and the blind via hole C2 to the one end 113s of the third coil pattern 113 in this order.
Thereafter, the current input to the one end 113s of the third coil pattern 113 is passed through the blind via hole C3b to the pad portion 114p and next output from the third output terminal 163.
Accordingly, in the case that the current is output from the third output terminal 163 in the first inductor 101b, the inductance value becomes different from those obtained in the other two cases described in the first preferred embodiment.
That is, in the first inductor 101b, three different inductance values can be selectively obtained.
In this preferred embodiment, the coil section 110 includes four terminals, i.e., the input terminal 151 and the first to third output terminals 161 to 163, which are connected at different positions. The connection to one of the plural output terminals 161 to 163 is selected so as to change the combination of the input terminal 151 and the plural output terminals 161 to 163. Accordingly, the inductance value in the first inductor 101b can be varied.
Accordingly, as in the first preferred embodiment, it is unnecessary to provide a plurality of inductors for supporting a plurality of different inductance values, so that the footprint of an inductor can be reduced. As a result, the module including the inductor in this preferred embodiment can be reduced in size.
A third preferred embodiment of the present invention will now be described.
As shown in
The insulating layer Z2c interposed between the first coil pattern 111 and the second coil pattern 112 is formed of a magnetic material rather than a nonmagnetic material.
For example, the insulating layer Z2c is formed by mixing magnetic powder such as ferrite powder with resin such as epoxy resin and polyimide.
For example, the magnetic powder is selected from MnZn ferrite, NiZn ferrite, NiZnCu ferrite, Ba ferrite, CoFe soft magnetic alloy, Fe soft magnetic alloy, Co soft magnetic alloy, NiFe soft magnetic alloy, and the combination thereof.
In this preferred embodiment, the insulating layer Z2c formed of a magnetic material is provided between the first output terminal 161 and the second output terminal 162. Accordingly, in outputting a current from the first output terminal 161, it is possible to prevent the losses due to eddy currents caused by the second to fourth coil patterns 112 to 114 located in the layers above the first output terminal 161.
While the magnetic insulating layer Z2c is formed by mixing magnetic powder with resin in this preferred embodiment, this configuration is merely illustrative. For example, the magnetic insulating layer Z2c may be formed by laminating a magnetic substrate.
A fourth preferred embodiment of the present invention will now be described.
As shown in
As in the first preferred embodiment, the first inductor 101d is configured in such a manner that when a current is passed through the first inductor 101d, the connection of the input terminal 151d and the plural output terminals 161d and 162d is changed in combination to thereby vary the inductance value.
The components of the first inductor 101d will now be described more specifically.
As shown in
The first and second coils 111d and 112d constituting the coil section 110d are arranged side by side in the x direction. Each of the first and second coils 111d and 112d is formed of a conductive material such as metal.
As shown in
More specifically, the first coil 111d includes a first coil pattern 111da and a second coil pattern 111db.
As shown in
The first coil pattern 111da includes a plurality of line patterns L1. As shown in
As shown in
Similarly, the lower end surface of a blind via hole C2d is connected to the upper surface of the other end 111daf of the first coil pattern 111da.
As shown in
The second coil pattern 111db includes a plurality of line patterns L2. As shown in
As shown in
As shown in
Similarly, the upper end surface of the blind via hole C2d is connected to the lower surface of the other end 111dbf of the second coil pattern 111db, and the lower end surface of the first output terminal 161d is connected to the upper surface of the other end 111dbf of the second coil pattern 111db.
On the other hand, as shown in
More specifically, the second coil 112d includes a third coil pattern 112da and a fourth coil pattern 112db.
As shown in
The third coil pattern 112da includes a plurality of line patterns L3. As shown in
As shown in
The lower end surface of a blind via hole C3d is connected to the upper surface of the other end 112daf of the third coil pattern 112da.
As shown in
The fourth coil pattern 112db includes a plurality of line patterns L4. As shown in
As shown in
As shown in
The upper end surface of the blind via hole C3d is connected to the lower surface of the other end 112dbf of the fourth coil pattern 112db, and the lower end surface of the second output terminal 162d is connected to the upper surface of the other end 112dbf of the fourth coil pattern 112db.
The operation of the first inductor 101d will now be described.
In the first inductor 101d, the connection of the first and second output terminals 161d and 162d is switched so that a current is output from one of the first and second output terminals 161d and 162d. More specifically, the connection between one of the first and second output terminals 161d and 162d and output wiring (not shown) through which an output current is passed is switched by a switching device (not shown).
Accordingly, in passing a current through the first inductor 101d, either the combination of the input terminal 151d and the first output terminal 161d or the combination of the input terminal 151d and the second output terminal 162d is selected, so that the inductance value in the first inductor 101d is variable according to this selection.
More specifically, in the case that the connection is switched so that a current is input from the input terminal 151d and output from the first output terminal 161d, the current is passed through the first coil 111d.
That is, the current is passed through only the first coil 111d and no current is passed through the second coil 112d.
More specifically, the current input to the one end 111dbs is passed through the first and second coil patterns 111da and 111db toward the other end 111dbf so as to form a cylindrical spiral about an axis extending in the x direction. The current is next output from the first output terminal 161d provided at the other end 111dbf.
In the case that the connection is switched so that a current is input from the input terminal 151d and output from the second output terminal 162d, the current is passed not only through the first coil 111d, but also through the second coil 112d.
More specifically, the current input to the one end 111dbs is passed through the first and second coil patterns 111da and 111db toward the other end 111dbf as in the above case. Thereafter, the current is passed through the blind via hole C2d to the other end 111daf of the first coil pattern 111da, which is connected to the one end of the third coil pattern 112da of the second coil 112d. Accordingly, the current is further passed through the third and fourth coil patterns 112da and 112db toward the other end 112dbf so as to form a cylindrical spiral about an axis extending in the x direction. The current is next output from the second output terminal 162d.
Accordingly, in the first inductor 101d, a first inductance value and a second inductance value different from the first inductance value can be selectively obtained.
In this preferred embodiment, the coil section 110d includes the input terminal 151d and the plural output terminals 161d and 162d, which are connected at different positions. The connection to one of the plural output terminals 161d and 162d is selected so as to change the combination of the input terminal 151d and the plural output terminals 161d and 162d. Accordingly, the inductance value in the first inductor 101d can be varied.
Accordingly, as in the first preferred embodiment, it is unnecessary to provide a plurality of inductors for supporting a plurality of different inductance values, so that the footprint of an inductor can be reduced. As a result, the module including the inductor in this preferred embodiment can be reduced in size.
The present invention is not limited to the above preferred embodiments, but various modifications may be made.
For example, while the current is passed through the plural coil patterns (or coils) constituting the coil section in the same direction, i.e., in the clockwise direction in the above preferred embodiments, the present invention is not limited to this configuration. That is, the current may be passed through the plural coil patterns in different directions. In other words, the current may be passed through the plural coil patterns in the clockwise and counterclockwise directions. In this case, the inductance value is reduced.
While one input terminal is provided in each preferred embodiment mentioned above, the present invention is not limited to this configuration. That is, a plurality of input terminals may be provided and the connection of these plural input terminals may be switched. In the case that at least three terminals are located at different positions in the coil section and that two of these plural terminals are used as the input terminals or the output terminals, the combination of the input terminals and the output terminals may be arbitrarily changed.
Further, the number of layers forming the coil patterns may be arbitrarily selected.
The first coil pattern 111 in the first to third preferred embodiments corresponds to the first coil in the present invention. The second, third, and fourth coil patterns 112, 113, and 114 in the first to third preferred embodiments correspond to the second coil in the present invention. The first coil 111d in the fourth preferred embodiment corresponds to the first coil in the present invention, and the second coil 112d in the fourth preferred embodiment corresponds to the second coil in the present invention. The input terminal 151 or 151d in the above preferred embodiments corresponds to the input terminal in the present invention. The first output terminal 161 or 161d, the second output terminal 162 or 162d, and the third output terminal 163 in the above preferred embodiments correspond to the output terminal in the present invention. The coil section 110 or 110d in the above preferred embodiments corresponds to the coil section in the present invention. The insulating layer Z2c in the third preferred embodiment corresponds to the magnetic insulating layer in the present invention.
The present application contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2008-319215 filed with the Japan Patent Office on Dec. 16, 2008, the entire content of which is hereby incorporated by reference.
It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.
Number | Date | Country | Kind |
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2008-319215 | Dec 2008 | JP | national |