Claims
- 1. A window glass antenna device comprising:
- a window glass panel;
- defrosting heaters for use as part of a reception antenna, said defrosting heaters including at least first and second heaters each comprising a plurality of heater wires disposed on said window glass panel, first bus bars interconnecting ends of said heater wires, and second bus bars interconnecting opposite ends of said heater wires;
- current supply means for supplying electric currents to said defrosting heaters;
- a first choke coil connected between the first bus bars of said first and second heaters and said current supply means; and
- a second choke coil connected between the second bus bars of said first and second heaters and said current supply means;
- said first choke coil having a core and at least two windings disposed around said core, said windings being connected respectively to the first bus bars of said first and second heaters such that magnetic fluxes generated in said core by a first electric current flowing through said first heater and a second electric current flowing through said second heater will be canceled;
- said second choke coil having a core and at least two windings disposed around said core, said windings being connected respectively to the second bus bars of said first and second heaters such that magnetic fluxes generated in said core by said first electric current flowing through said first heater and said second electric current flowing through said second heater will be canceled; and
- at least one of said first and second choke coils including a third winding disposed around said core, and current adjusting means for supplying an electric current from said current supply means to said third winding for producing a magnetic flux to cancel any magnetic flux produced by the difference between electric currents flowing through said two windings of said at least one of said first and second choke coil.
- 2. A window glass antenna device according to claim 1, wherein said first heater has a first combined resistance and said second heater has a second combined resistance, said first combined resistance being equal to said second combined resistance.
- 3. A window glass antenna device according to claim 2, wherein said first heater is above said second heater, said first and second heaters including an uppermost and lowermost heater wire, said heater wires of said first heater extend substantially parallel to each other, and said heater wires of said second heater extend substantially parallel to each other, said first and second heaters being trapezoidal in shape with said uppermost heater wire of said first heater defining an upper side, and said lowermost heater wire of the second heater defining a lower side, and the bus bars defining right and left sides.
- 4. A window glass antenna device according to claim 3, wherein the number of the heater wires of said first heater is different from the number of the heater wires of said second heater in order to equalize said first combined resistance to said second combined resistance.
- 5. A window glass antenna device according to claim 3, wherein the width of the heater wires of said first heater and the width of the heater wires of said second heater are adjusted in order to equalize said first combined resistance to said second combined resistance.
- 6. A window glass antenna device according to claim 1, further comprising an antenna disposed in capacitive coupling with one of said first and second heaters.
- 7. A window glass antenna device according to claim 6, wherein said defrosting heaters further include a third heater disposed between said first and second heaters, said antenna including first and second patterns disposed in independent capacitive coupling with said first and second heaters, respectively.
- 8. A window glass antenna device comprising:
- a window glass panel;
- defrosting heaters for use as part of a reception antenna, said defrosting heaters including at least first and second heaters each comprising a plurality of heater wires disposed on said window glass panel, first bus bars interconnecting ends of said heater wires, and second bus bars interconnecting opposite ends of said heater wires;
- current supply means for supplying electric currents to said defrosting heaters;
- a first choke coil connected between the first bus bars of said first and second heaters and said current supply means; and
- a second choke coil connected between the second bus bars of said first and second heaters and said current supply means;
- said first choke coil having a core at least two windings disposed around said core, said windings being connected respectively to the first bus bars of said first and second heaters such that magnetic fluxes generated in said core by a first electric current flowing through said first heater and a second electric current flowing through said second heater will be canceled;
- said second choke coil having a core and at least two windings disposed around said core, said windings being connected respectively to the second bus bars of said first and second heaters such that magnetic fluxes generated in said core by said first electric current flowing through said first heater and said second electric current flowing through said second heater will be canceled; and
- at least one of said two windings of each of said first and second choke coils including a plurality of taps selectable to provide a number of winding turns for canceling the magnetic fluxes generated in said core by said first electric current flowing through said first heater and said second electric current flowing through said second heater.
- 9. A window glass antenna device having first and second defrosting heaters disposed independently of each other on an automobile window glass panel, first and second choke coils independent of each other and each having a core and first and second windings disposed independently of each other on said core, and a heating power supply for supplying electric currents to said first and second defrosting heaters, said first windings of said first and second choke coils being connected between one and other ends of said first defrosting heater and said heating power supply, said second windings of said first and second choke coils being connected between one and other ends of said second defrosting heater, which are positioned on the same side of said one and other end of said first defrosting heater, and said heating power supply, said first and second defrosting heaters being used as part of a reception antenna, characterized in that at least one of said first second choke coils has a third winding disposed around said core, and current adjusting means for supplying an electric current from said heating power supply to said third winding for producing a magnetic flux to cancel any magnetic flux produced in said core by the difference between electric currents flowing through said first and second windings.
- 10. A window glass antenna device according to claim 9, wherein at least one of said first and second choke coils has a plurality of taps on at least one of said first and second windings to provide corresponding numbers of winding turns, said taps being selectable for connection to said heating power supply to supply electric currents from said heating power supply to cancel magnetic fluxes generated in said core by said first and second windings.
Priority Claims (2)
Number |
Date |
Country |
Kind |
4-059949 U |
Aug 1992 |
JPX |
|
4-327371 |
Nov 1992 |
JPX |
|
Parent Case Info
This is a file wrapper continuation of application Ser. No. 08/100,930, filed Aug. 3, 1993, now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
4914446 |
Lindenmeier et al. |
Apr 1990 |
|
5231410 |
Murakami et al. |
Jul 1993 |
|
5239302 |
Maeda et al. |
Aug 1993 |
|
Continuations (1)
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Number |
Date |
Country |
Parent |
100930 |
Aug 1993 |
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