Communication apparatus for vehicle

• US 20070030119A1
• Filed: 10/14/2005
• Published: 02/08/2007
• Est. Priority Date: 07/08/2005
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Ono, Masayoshi, Katayama, Masahiko, Sumida, Masato, Ooba, Tetsuya, Uehara, Naohisa
• Granted Patent: US 9,126,564 B2
• Time in Patent Office: Days
• US Class Current: 340/5.610
• CPC Class Codes: B60R 25/24 using electronic identifiers containing a code not memorised by the user
• CPC Class Codes: G05B 2219/33192 Radio link, wireless
• CPC Class Codes: G05B 2219/36159 Detachable or portable programming unit, display, pc, pda

Abstract

A communication apparatus for a vehicle achieves reduction in size and cost of a portable unit by making unnecessary an oscillation circuit and a battery in the portable unit. The apparatus is provided with an on-board unit installed on the vehicle and a portable unit carried by a user of the vehicle. A response signal is sent from the portable unit to the on-board unit in response to a signal transmitted from the on-board unit. The portable unit includes a power generation circuit for supplying electric power to circuits in the portable unit by a power generation radio wave sent from the on-board unit, and the on-board unit sends a communication signal after sending the power generation radio wave.

Claims

1. A communication apparatus for a vehicle comprising:

an on-board unit installed on a vehicle; and

a portable unit adapted to be carried by a user of said vehicle;

wherein a response signal is sent from said portable unit to said on-board unit in response to a signal transmitted from said on-board unit;

said portable unit includes a power generation circuit for supplying electric power to circuits in said portable unit by a power generation radio wave sent from said on-board unit; and

said on-board unit sends a communication signal after sending said power generation radio wave.

2. The communication apparatus for a vehicle as set forth in claim 1, wherein

said on-board unit intermittently sends said power generation radio wave over a period from a time point of sending said communication signal to a time point of receiving said response signal from said portable unit.

3. The communication apparatus for a vehicle as set forth in claim 1, wherein

said communication signal is an authentication request signal to verify operation permission of an on-board device installed on said vehicle;

said portable unit sends an ID signal specific to itself as said response signal in response to said authentication request signal; and

said on-board unit generates an authentication signal to permit the operation of said on-board device after verifying that the ID signal received from said portable unit coincides with an ID signal registration value stored beforehand.

4. The communication apparatus for a vehicle as set forth in claim 3, wherein

said on-board unit transmits said power generation radio wave and said authentication request signal over a plurality of times while changing the level of transmission power in a plurality of steps, and specifies the positions of said portable unit at time points at which said ID signals are received, based on the reception states of said ID signals from said portable unit corresponding to said plurality of transmissions.

5. The communication apparatus for a vehicle as set forth in claim 4, wherein

said on-board device is a door locking and unlocking device for said vehicle;

and

when it is determined that the ID signal of said portable unit coincides with said ID signal registration value and that said portable unit exists outside said vehicle, said on-board unit executes unlocking processing of said doors by making said door locking and unlocking device operable.

6. The communication apparatus for a vehicle as set forth in claim 5, wherein

when it is determined that said portable unit exists in a passenger compartment of said vehicle, said on-board unit does not execute unlocking processing of the doors of said vehicle.

7. The communication apparatus for a vehicle as set forth in claim 5, further comprising a lock switch installed on an outer side of a door of said vehicle,

wherein said on-board unit sends a warning command when it is determined that said portable unit exists in a passenger compartment of said vehicle upon pressing of said lock switch;

and

said portable unit is provided with a receiving circuit that receives said warning command and a warning section for generating a warning sound in response to said warning command.

8. The communication apparatus for a vehicle as set forth in claim 4, further comprising an indicator installed on said vehicle,

wherein said on-board unit makes the position of said portable unit indicated on said indicator.