JP4443461B2 - In-vehicle wireless receiver - Google Patents

Description

  The present invention relates to a technique for self-diagnosis of a failure of an in-vehicle wireless reception device that receives wireless radio waves such as AM or FM radio broadcasts and television broadcasts.

  In an AM / FM car radio, which is a typical in-vehicle wireless receiver, when an event that seems to be a performance defect such as poor sensitivity occurs, usually an ordinary user or a car dealer (hereinafter also referred to as the user side). Take out the AM / FM car radio installed in the console box of the vehicle, exchange it with a new AM / FM car radio, listen to the actual radio station, compare the performance, and check for defects. Is going.

  If the expected performance is still not obtained, the same inspection work is repeated again by replacing the external antenna connected to the AM / FM car radio.

  As described above, for the occurrence of a malfunction of a conventional in-vehicle wireless receiver mounted on a vehicle, it is necessary to perform a very troublesome work on the user side at the beginning of the cause investigation, and the above troublesome work is obtained. In many cases, all the troubles that occurred are immediately determined by the user due to the failure of the in-vehicle wireless receiver and returned to the manufacturer. However, in fact, the in-vehicle wireless reception device itself is normal, and there is a conspicuous case that the external antenna connected to this has a cause of malfunction.

  In the case as described above, the burden on the manufacturer corresponding to the return claim is large, and an appropriate diagnosis of the cause of failure (failure diagnosis) when a failure occurs on the user side is required.

  As a publicly known document regarding this point, as shown in FIG. 3, the following [Patent Document 1] is provided with a self-diagnosis switch 21 for self-diagnosis of a failure of the radio receiver 20 (particularly for a pager). Then, the control unit 22 in the signal processing unit 30 outputs a switching signal to the switching unit 23, connects the FM detection circuit 24 to the pseudo code verification unit 25, causes the pseudo code generator 26 to generate a pseudo code, The pseudo-code collator 25 and the oscillator / modulator 27 are output, the modulated wave generated by the oscillator / modulator 27 is input to the antenna unit ANT, and the received signal received by the antenna unit ANT is amplified and detected. The pseudo code collator 25 inputs the received signal from the FM detection circuit 24 and compares the received signal with the pseudo code from the pseudo code generator 26. And the pseudo-code match, drives the speaker SP via the I / O driver circuit 29, the self-diagnosis system configuration of outputting an alarm sound is disclosed. In FIG. 3, reference numeral 31 is a high-frequency amplifier, 32 and 35 are band-pass filters, 33 is a mixer, 34 is a local oscillator, 36 is an IF amplifier, and 24 is an FM detection circuit.

  In [Patent Document 2] below, as shown in FIG. 4, the amplification in the detection / demodulation circuit 41 that receives the reception signal from the reception circuit 39 that processes the reception signal input to the antenna ANT in the reception apparatus. The circuit uses an amplifier circuit 42 capable of outputting an RSSI signal (voltage signal) corresponding to the received signal level. On the failure determination circuit 50 side, the RSSI signal and the failure determination value obtained by the level detection function of the amplifier circuit 42 are used. A receiving device 40 is disclosed in which a comparator 54 compares the magnitude of the reference voltage Vref2 with a comparator 54 and determines a failure of the receiving circuit 39 when the RSSI signal is lower than the reference voltage Vref2. In FIG. 4, reference numerals 32 and 35 are band-pass filters, 31 is a high-frequency amplifier, 33 is a mixer, 34 is a local oscillator, 44 is a detection circuit, 46 is a low-pass filter, and 48 and 52 are comparators.

  Furthermore, as shown in FIG. 5, the following [Patent Document 3] discloses a vehicular reception device 60 for remote control capable of self-diagnosis with the wireless door lock control device 70 of the vehicle in mind, An RF reception circuit 61, a control circuit 62, a switch 63, a noise generation circuit 64, and an antenna ANT are provided, and a transmission signal from the transmission device 65 (integrated with the engine key) is transmitted to the RF through the antenna ANT. When the function is checked, the switch 63 is connected to the contacts CP1 and CP3, and white noise is output from the noise generation circuit 64. The RF reception circuit 61 receives a reception signal based on the white noise. The control circuit 62 compares the received signal with the determination signal, and the RF receiving circuit 61 A configuration to determine whether it is operating in.

JP-A-7-131429

JP 2001-16125 A JP 2000-64681 A

  On the side of a general user or card dealer, the in-vehicle wireless reception device (typically AM / FM car radio, other wireless communication device or GPS receiver is considered) side failure or external antenna side Without disconnecting the in-vehicle wireless receiver already mounted on the vehicle (with the external antenna connected without being disconnected electrically or physically) If there is a self-diagnosis system for an in-vehicle wireless receiver configured so that it can be easily judged, it will be possible to reduce unnecessary return claims for a normal in-vehicle wireless receiver.

  In this regard, in the wireless receiver 20 of the above-mentioned [Patent Document 1], the self-oscillated pseudo signal is received by the antenna unit, and the received signal and the self-oscillated pseudo signal are compared and determined. Therefore, it cannot cope with the determination of whether the problem is on the external antenna side or on the receiving apparatus side, which is the problem of the present invention. In addition, the oscillation / modulation circuit 27 and the pseudo code generator 26 must be provided in the signal processing unit 30 separately, which makes the circuit configuration complicated.

  Next, the receiving device 40 of [Patent Document 2] has a configuration in which an external transmission radio wave is received and the reception level is determined with respect to a reference level. It is clear that it is not possible to cope with the determination of the malfunction on the external antenna side or the malfunction on the receiving apparatus side. In order to cope with the above-described problem in the receiving device 40, an operation of disconnecting the connection between the external antenna ANT and the receiving device 40 must be performed, and an operation of removing the receiving device 40 from the vehicle is essential.

  Further, the remote control receiving device 70 of the above [Patent Document 3] is provided with the noise generating circuit 64 separately, and has the same configuration as that of the above [Patent Document 1]. It is not possible to determine whether or not there is a problem on the receiving device side while the receiving device is mounted on the vehicle and the external antenna ANT is also connected.

  The present invention has been made in view of the above circumstances, and whether a failure (fault) that has occurred while the vehicle-mounted wireless reception device is mounted on the vehicle is usable is a failure on the external antenna side. It is an object of the present invention to realize a self-diagnosis system that allows a user to easily determine whether or not a device is defective.

According to the present invention, in an in-vehicle wireless receiver, external antenna separating means for separating the external antenna ANT from the antenna input circuit 2 of the tuner unit 5 at high frequency, and the external antenna ANT and the antenna input circuit 2 are separated at high frequency. In this state, the noise level detecting means for detecting the noise level Vsm output to the signal meter S of the intermediate frequency unit 3 during the operation of the tuner unit 5, and the detected noise level Vsm or the noise level Vsm display means and the noise level converted value DVsm converted by the AD converter 9 is displayed and the noise level determining means for determining whether within a predetermined reference level Vr, the display unit 12 a determination result of the noise level determining means At least one of the informing means for informing the determination result by voice output It means, by providing a vehicle radio receiver 18, characterized in that it comprises a self-diagnostic system consisting of, for solving the above problems.

  Since the in-vehicle wireless reception device according to the present invention includes the self-diagnosis system configured as described above, the reception failure of the in-vehicle wireless reception device attached to the vehicle is caused on the external antenna side. Whether or not there is a cause on the in-vehicle wireless reception device side, the user side sets the diagnosis mode by operating a predetermined panel switch without removing the in-vehicle wireless reception device from the vehicle. Since the determination result is displayed on the display unit or notified by voice, the user can easily determine whether there is a problem with the in-vehicle wireless reception device at low cost without removing it from the vehicle. Has an effect.

  In addition, as a result of the above-mentioned appropriate judgment on the user side, it is possible to reduce the return claim of the non-defective in-vehicle wireless reception device, thereby bringing about an effect that the service cost can be greatly reduced.

  An embodiment of an in-vehicle wireless reception device equipped with a self-diagnosis system according to the present invention will be described based on the drawings with respect to an FM car radio receiver as a typical example. The detailed description and description of the FM radio receiver equivalent to the prior art will be omitted, and the components of the added self-diagnosis system characteristic of the present invention and the blocks related thereto will be described in detail.

  FIG. 1 is a block circuit diagram for explaining the configuration of an in-vehicle wireless receiver 18 according to the present invention. FIG. 2 is a circuit diagram of the external antenna disconnecting switch circuit 1 in the external antenna disconnecting means for isolating the external antenna ANT, which is a component according to the present invention, from the antenna input circuit 2 of the tuner unit 5 in a high frequency manner.

  In FIG. 1 or FIG. 2, the in-vehicle wireless receiver 18 is configured by an antenna input circuit 2 (high frequency amplifier, mixer, local oscillator, etc.) of the tuner unit 5 by controlling the switch of the power supply unit 10 by the microcomputer 8. The external antenna separating means for separating at high frequency, the external antenna ANT and the antenna input circuit 2 being separated at high frequency, when the tuner unit 5 is in operation. Noise level detection means for detecting the noise level Vsm output to the signal meter S of the intermediate frequency unit 3, and the detected noise level Vsm or the noise level converted by converting the noise level Vsm by the AD converter 9 of the microcomputer 8 The value DVsm (for example, 8-bit data) is a predetermined value A noise level determination means for determining whether or not it is within the range of the quasi-level Vr by the CPU in the microcomputer 8, and the determination result by the noise level determination means is displayed on the liquid crystal or CRT display unit 12 as "GOOD" or "ERROR". "This receiver is operating normally" from the display means to display or / and the speaker SP, "A failure has been found in the reception function of this receiver", "Problem with external antenna Notification that the determination result is output from the speaker SP by voice output of voice data recorded in a memory device (such as the built-in ROM of the microcomputer 8) not shown in advance. And a self-diagnosis system comprising the means. In FIG. 1, reference numeral 4 denotes a general MPX demodulator, reference numeral 6 denotes an electronic volume, reference numeral 7 denotes an output stage amplifier, and reference numeral 11 denotes a key input device on the operation panel.

  The external antenna disconnecting means mainly includes an external antenna disconnecting switch circuit 1 inserted between the external antenna ANT and the antenna input circuit 2 of the tuner unit 5.

  The external antenna disconnection switch circuit 1 has a configuration as shown in FIG. 2, for example, and uses a PIN diode D1 (specifically, a silicon epitaxial PIN diode ISV307 manufactured by Toshiba). A capacitor C and an inductor L are connected to both terminals. The electronic switch circuit is configured by connecting the two.

  When the receiving device 18 is in a normal receiving state, the microcomputer 8 controls the power supply unit 10 to turn on the switch switching control signal SWC (application of 5V to 8V DC power supply) and disconnect the external antenna. A switch circuit 1 is applied, and a direct current i is passed through the PIN diode D1 in the direction of the arrow to turn on the PIN diode D1, thereby turning it on in a high frequency state (the electronic switch is turned on).

  Next, when the user designates the self-diagnosis mode by a predetermined key operation of the key input device 11 on the operation panel surface, the microcomputer 8 controls the power supply unit 10 to turn off the switch switching control signal SWC. The PIN diode D1 is cut off to make it non-conductive in high frequency (the electronic switch is off), and the external antenna ANT is connected to the tuner unit 5 (RF IN of the antenna input circuit 2) of the in-vehicle wireless receiver 18 in a high frequency manner. It has become a mechanism to separate.

  When a failure occurs, the microcomputer 8 shifts to a self-diagnosis mode by a predetermined key operation of the key input device 11 on the user side, and controls the power supply unit 10 to output to the external antenna disconnection switch circuit 1. The switch switching control signal SWC is turned off, and the external antenna ANT and the antenna input circuit 2 are separated in a high frequency manner. As a result, the cause of the malfunction due to the influence of the antenna can be eliminated.

  Further, when the microcomputer 8 enters the self-diagnosis mode, the microcomputer 8 shifts to a reception state of a certain FM reception frequency (which may be a frequency of a broadcasting station that is currently broadcasted, but is preferably a frequency that is not broadcasted). The tuner unit 5 is BUS controlled. At this time, the noise voltage Vsm generated in the intermediate frequency unit 3 of the tuner unit 5 (in the FM radio receiver, the noise voltage appearing in the S meter voltage obtained by rectifying the intermediate frequency of 10.7 MHz) is converted into the microcomputer 8. Whether the noise level converted value DVsm (for example, 8-bit data) converted by the AD converter 9 is within a predetermined reference level Vr range (for example, 1.0 V ± 0.3 V range) is determined by the CPU in the microcomputer 8. If the level within the range is output, “GOOD”, “normal” or the like is displayed on the display unit to determine that the tuner unit 5 is normal. If it is out of the range, “ERROR”, “with failure” or the like is displayed and it is determined that there is a malfunction in the tuner unit 5. Alternatively, at the same time, the determination result is output by voice from the speaker SP and notified.

  Note that the noise voltage Vsm to be determined is thermal noise generated when the antenna input circuit of the tuner unit 5 and the intermediate frequency unit 3 perform a receiving operation. If the receiving device 18 is normal, the external antenna ANT is disconnected. However, the value should be a value that falls within a predetermined reference level Vr that does not include 0V.

  In addition, the above configuration is an example of an FM car radio receiver, but of course, the present invention can also be applied to an in-vehicle AM radio receiver and an in-vehicle television receiver.

It is a block circuit diagram for demonstrating the structure of the vehicle-mounted radio | wireless receiver which concerns on this invention. It is an external antenna separation switch circuit in the external antenna separation means for separating the external antenna ANT, which is a component according to the present invention, from the antenna input circuit of the tuner section at high frequency. It is a block circuit diagram of the radio receiver given in [patent documents 1]. It is a block circuit diagram of a receiving device given in [patent documents 2]. It is a block circuit diagram of the receiver for remote control described in [Patent Document 3].

Explanation of symbols

1 External antenna disconnection switch circuit
2 Antenna input circuit
3 Intermediate frequency section
4 MPX demodulator
5 Tuner club
6 Electronic volume
7 Amplifier
8 Microcomputer
DESCRIPTION OF SYMBOLS 9 AD converter 10 Power supply part 11 Key input device 12 Display part 18 In-vehicle wireless receiver 20 Wireless receiver (pager)
40 Receiver 70 Wireless Door Lock Control Device ANT External Antenna D1 PIN Diode
L inductor
C capacitor
S Signal meter SP Speaker Vsm Noise level DVsm Noise level converted value Vr Reference level SWC Switch switching control signal

Claims (1)

In the in-vehicle wireless receiver,
An external antenna separating means for separating the external antenna from the antenna input circuit of the tuner section at high frequency;
A noise level detecting means for detecting a noise level output to a signal meter of an intermediate frequency section during operation of the tuner section in a state where the external antenna and the antenna input circuit are separated in a high frequency manner;
Noise level determination means for determining whether the detected noise level or a noise level converted value obtained by converting the noise level with an AD converter is within a predetermined reference level;
At least one of display means for displaying a determination result by the noise level determination means on a display unit and notification means for notifying the determination result by audio output;
An in-vehicle wireless receiver comprising a self-diagnosis system comprising:

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