Apparatus for determining failure of vehicle antenna

• US 7,791,493 B2
• Filed: 02/14/2008
• Issued: 09/07/2010
• Est. Priority Date: 02/28/2007
• Status: Expired due to Fees

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Ikeura, Masashi
• Primary Examiner(s): TWEEL JR, JOHN ALEXANDER
• Application Number:
  US12/031,240
• Publication Number:
  US 20080204332A1
• Time in Patent Office: 936 Days
• Field of Search: 340/635, 340/653, 361/15, 361/17, 361/92, 343/703, 343/711
• US Class Current: 340/635
• CPC Class Codes: H01Q 1/3241 particular used in keyless entry systems

Abstract

An on-vehicle device has a receiving antenna for receiving a radio signal from a mobile device, a receiving circuit for returning an electric signal obtained by conversion by the receiving antenna to the original state, a control unit for determining whether a received signal from the receiving circuit is correct or incorrect, a driving circuit that is driven in response to a driving signal from the control unit and supplies antenna current to a vehicle antenna, and a detector for detecting whether the vehicle antenna operates normally. A detection signal of the detector is fed back to the control unit through the receiving circuit, and the failure determination of the vehicle antenna is performed.

Claims

1. An on-vehicle device comprising:

a receiving antenna for receiving a radio signal from a mobile device;

a receiving circuit for returning an electric signal obtained by conversion by the receiving antenna to a state of an original transmitted signal supplied from the mobile device;

a control unit for determining whether a received signal from the receiving circuit is correct or incorrect;

a driving circuit that is driven in response to a driving signal from the control unit and supplies antenna current to a vehicle antenna; and

a detector for detecting whether the vehicle antenna operates normally,

wherein the detector is formed of a capacitor, and

wherein, when a detection signal of the detector for detecting a failure of the vehicle antenna is fed back to the control unit, the control unit determines a failure of the vehicle antenna based on the detection signal.

2. The on-vehicle device of claim 1, wherein

one end of the capacitor is connected to a midpoint between the driving circuit and the vehicle antenna, and the other end of the capacitor is connected to the input side of the receiving circuit.

3. The on-vehicle device of claim 1, wherein

the control unit stops operation of the driving circuit when the control unit determines that the vehicle antenna is failed.

4. The on-vehicle device of claim 1, wherein

the control unit performs announcement when the control unit determines that the vehicle antenna is failed.