Receiving system having a plurality of frequency converters for use with a vehicle

• US 6,760,579 B1
• Filed: 11/29/1999
• Issued: 07/06/2004
• Est. Priority Date: 11/27/1998
• Status: Expired due to Fees

• Current Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Original Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Inventors: Yokoyama, Masaho, Horimoto, Manabu
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): SHARMA, SUJATHA R
• Application Number:
  US09/449,482
• Time in Patent Office: 1,681 Days
• Field of Search: 455/345, 455/352-354, 455/132, 455/200.1, 455/227, 455/315, 340/825.44, 340/825.72, 340/825.31, 340/5.72, 340/5.61, 340/5.64
• US Class Current: 455/352
• CPC Class Codes: B60R 25/245 where the antenna reception area plays a role
• CPC Class Codes: G07C 2009/00793 by Hertzian waves
• CPC Class Codes: G07C 9/00182 operated with unidirectional data transmission between data carrier and locks
• CPC Class Codes: H04B 1/3805 with built-in auxiliary receivers

Abstract

The present invention provides a mobile receiver, whereby the power consumption can be kept as lower as possible, as the size of the automobile equipment control system, the placement space thereof and the cost can be reduced, since an antenna and part of receiving circuits for keyless entry system are also used as those of a mobile radio receiver. Moreover, in order to prevent the users from feeling inconvenience in its use, the mobile receiver has a construction wherein a mixing circuit, a local oscillator circuit and the like for keyless entry system and those for radio receiver are separately arranged though the antenna and an intermediate frequency amplifier circuit are used both for keyless entry system and for radio receiver. As a result, signals from the remote control side can be received even while someone is listening to the radio.

Claims

1. A mobile receiver, comprising an antenna used both for receiving remote control signals for remotely controlling a drive mounted on a vehicle and for receiving radio signals, remote control receiving circuits and radio receiving circuits, an intermediate frequency amplifier circuit of the remote control receiving circuits and an intermediate frequency amplifier circuit of the radio receiving circuits being one and the same, the remote control receiving circuits, including:

a remote control frequency converter for converting remote control signals input through the antenna to intermediate frequency signals of a prescribed frequency and outputting the signals to the intermediate frequency amplifier circuit;

a remote control detector circuit for detecting the intermediate frequency signals amplified in the intermediate frequency amplifier circuit and outputting remote control detected signals; and

a remote control filter for taking only remote control signals out of the remote control detected signals output from the remote control detector circuit; and

the radio receiving circuits, including;

a radio frequency converter for converting radio signals input through the antenna to intermediate frequency signals of the prescribed frequency and outputting the signals to the intermediate frequency amplifier circuit;

a radio detector circuit for detecting the intermediate frequency signals amplified in the intermediate frequency amplifier circuit and outputting radio detected signals; and

a radio filter for taking only radio signals out of the radio detected signals output from the radio detector circuit;

the frequency converters each and the filters each being separate; and

the antenna being normally connected to both the remote control frequency converter and the radio frequency converter.

2. A mobile receiver according to claim 1, wherein the first and second frequency conversion means comprise local oscillator circuits.

3. A mobile receiver according to claim 1, wherein the first and second frequency conversion means comprise local oscillator circuits and mixing circuits.

4. A mobile receiver according to claim 1, including:

the remote control receiving circuits including plural signal processing elements to output a processed signal to the next step;

switches being interposed in each power line for supplying electric power to each of the signal processing elements; and

a first control means to perform sequential intermittent on/off control of each of the switches at a prescribed timing.

5. A mobile receiver according to one of claims 4, wherein each of the signal processing elements is a first frequency conversion means to convert a signal input from the antenna into a prescribed frequency, an amplifier circuit to amplify the received signal converted by the first frequency conversion means, or a first filter for filtering the received signal amplified in the amplifier circuit to separate a signal for radio receiver from a signal for remote control.

6. A mobile receiver according to claim 1, including:

the remote control receiving circuits including plural signal processing elements to output a processed signal to the next step;

switches being interposed in each power line for supplying electric power to each of the signal processing elements;

a second control means to perform on/off control of each of the switches; and

delay circuits being interposed in each control line for transmitting an on/off control signal from the second control means to each of the switches, whereby each of the switches is intermittently turned on and off in sequence.

7. A mobile receiver according to claim 6, wherein each of the signal processing elements is a first frequency conversion means to convert a signal input from the antenna into a prescribed frequency, an amplifier circuit to amplify the received signal converted by the first frequency conversion means, or a first filter for filtering the received signal amplified in the amplifier circuit to separate a signal for radio receiver from a signal for remote control.

8. A mobile receiver according to claim 1, including:

the remote control receiving circuits including plural signal processing elements to output a processed signal to the next step;

switches being interposed in each power line for supplying electric power to each of the signal processing elements;

a judging means to detect a signal output from a given signal processing element being supplied with electric power and judging whether a remote control signal is existent in the output signal or not; and

a third control means to perform on/off control of the switch interposed in the power line for supplying electric power to a signal processing element in the next step to the given signal processing element on the basis of the judgement result from the judging means, whereby each of the switches is intermittently turned on and off in sequence.

9. A mobile receiver according to claim 8, wherein each of the signal processing elements is a first frequency conversion means to convert a signal input from the antenna into a prescribed frequency, an amplifier circuit to amplify the received signal converted by the first frequency conversion means, or a first filter for filtering the received signal amplified in the amplifier circuit to separate a signal for radio receiver from a signal for remote control.

10. A mobile receiver according to claim 1, wherein the drive performs the lock/unlock of the vehicle doors and the like.