JP2552951Y2 - Car radio receiver - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle radio receiver, and more particularly to an on-vehicle radio receiver for stereo display.

[0002]

2. Description of the Related Art A stereo display of an on-vehicle radio receiver detects a stereo pilot signal (19 KHz) and displays whether or not a stereo broadcast is based on the presence or absence of the pilot signal.

[0003]

However, in the case of an in-vehicle radio receiver, there is a problem that the stereo display is not performed despite the stereo broadcast because the radio wave condition changes with the movement of the vehicle.

[0004] In particular, in such a case, the stereo display repeatedly blinks, so that the user may judge that it is malfunctioning.

[0005] The present invention has been made in view of the above points, and has as its object the Radio Data System.
An object of the present invention is to provide an in-vehicle radio receiver capable of performing more stable display by using the decoder identification code of m.

[0006]

FIG. 1 is a functional block diagram of the present invention.

The in-vehicle radio receiver of this invention is Radio
In a vehicle-mounted radio receiver comprising data demodulation means for demodulating data of a Data System and displaying stereo based on the presence or absence of a stereo pilot signal, a value of bit 0 of a decoder identification code to be demodulated by the data demodulation means is provided. A logical sum with a signal indicating the presence or absence of the pilot signal is obtained, and stereo display is performed based on the result of the logical sum.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an in-vehicle radio receiver according to the present invention will be described with reference to FIGS.

In the figure, reference numeral 1 denotes a Radio Data System (hereinafter, referred to as Radio Data System).
RDS), a front end having a high-frequency amplifier for amplifying radio waves received by the antenna 1 and a mixer for converting the radio waves to a predetermined intermediate frequency. Is a PLL circuit functioning as a local oscillator of the front end 2, 4 is an intermediate frequency amplification circuit including a detection circuit, 5 is RDS data demodulation means for demodulating RDS data from the output of the intermediate frequency amplification circuit 4, and 6 is a stereo pilot. Signal (19KHz)
, A microcomputer for controlling the in-vehicle radio receiver, 8 an arithmetic unit for calculating the logical sum of two signals (or data), and 9 a display for displaying a stereo broadcast. .

In the RDS system, a bit of a decoder identification code (hereinafter referred to as a DI code), which is a switching signal, is used.
When 0 is 1, stereo broadcasting is indicated.

In the in-vehicle radio receiver according to the present invention, the arithmetic means 8 demodulates the RDS data demodulated by the RDS data demodulating means 5.
Value B ₀ of the bit 0 of the code and the pilot signal detecting circuit 6
During the stereo broadcast by the RDS system, the logical sum with the detection signal P is calculated.
Even if the state of the radio wave deteriorates and the pilot signal detection circuit 6 does not output the detection signal P due to the phase shift or the level decrease of the pilot signal, the stereo display may be stopped due to the signal by the DI code. Absent.

Of course, even during a stereo broadcast not based on the RDS system, since the pilot signal detection circuit 6 detects the pilot signal, a stereo display is performed on the display 9 as in the related art.

[0013]

According to the in-vehicle radio receiver according to the present invention, since it is configured as described above, stable stereo display can be performed during reception of stereo broadcast by the RDS system.

[0014] In addition, there is also an effect that stereo display is performed as in the related art even in a broadcast not based on the RDS system.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram of the hardware.

[Explanation of symbols]

 5 RDS data demodulation means 6 Pilot signal detection circuit 8 Operation means 9 Display

Claims (1)

(57) [Scope of request for utility model registration] 1. An in-vehicle radio receiver comprising data demodulation means for demodulating data of a Radio Data System and displaying stereo based on the presence or absence of a stereo pilot signal, a decoder identification code demodulated by said data demodulation means. An in-vehicle radio receiver configured to take a logical sum of a value of pit 0 of the above and a signal indicating the presence or absence of the pilot signal, and perform stereo display based on a result of the logical sum.