JP3240460B2 - Car radio receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to radio data
The present invention relates to an on-vehicle radio receiver having a receiving function of receiving data of a multiplex broadcasting system , and more particularly to an on-vehicle radio receiver having an improved alternative frequency search function.

[0002]

2. Description of the Related Art Conventionally, RDS (Radio D
Ata System) Radio receivers that can receive data have become widespread. Based on this RDS data, AF (Alternative
Frequency) search function can be performed, but this function is used when the car moves and goes out of the service area of a broadcasting station being listened to in the on-vehicle radio receiver.
When the user enters the service area of another broadcasting station having a different frequency to the destination where the same broadcasting program is being broadcast, the system automatically switches to the receiving frequency of the another broadcasting station and continuously listens to the same broadcasting program. You can do it. Each broadcasting station transmits RDS data including, as an AF list, frequency data of a network station adjacent to the periphery of the service area of the broadcasting station.

As shown in Japanese Utility Model Publication No. 7-22911, in a vehicle-mounted radio receiver having an AF search function, a clock device and whether or not a predetermined time based on the clock device is determined. Identification means is provided for identifying, and the clock device is provided with a CT (Clock Tim) in the RDS data.
e) The time is corrected by the data, and when the identification means identifies that the time is a predetermined time, the AF search operation for the frequency being received is prohibited, and
2. Description of the Related Art There is an on-vehicle radio receiver that prevents an inability to receive CT data due to an F search operation and enables accurate and high-speed clock adjustment. In this case, the CT data is RDS
It is sent from the station once every minute, and the receiver calibrates the clock device when CT data is received, for example, three times, in order to prevent erroneous display of the clock device due to deterioration of the radio wave condition.

In such a receiver, as shown in the flowchart of FIG. 3, it is determined whether or not the clock device is in an undetermined state ( step S11). It is checked whether it is less than second ( step S1).
2) When the time of the clock device is 58 seconds, 59 seconds, 0 seconds, and 1 second, there is a high possibility that the CT data will be transmitted from the broadcasting station .
Step S13), followed by calibrating the clock unit with CT data (corrected) to have (step S14). (The reason why the AF search is invalidated is that the RDS is out of synchronization. While the RDS is out of synchronization, the RDS data cannot of course be taken in.) On the other hand, if NO in steps S11 and S12, the AF search A start check was performed ( step S15).

[0005]

However, in the on-vehicle radio receiver performing the above operation, even if the currently receiving station is a station that does not transmit CT data, an unnecessary AF search operation is prohibited. The search was invalidated (it was impossible to perform an AF search).
SUMMARY OF THE INVENTION It is an object of the present invention to provide an on-vehicle radio receiver having an improved AF search function by preventing a meaningless AF search prohibition time from being created.

[0006]

SUMMARY OF THE INVENTION An on-vehicle radio receiver according to the present invention comprises a radio data multiplex broadcasting system.
The in-vehicle radio receiver having a reception function for receiving, and alternative frequency search circuit, a clock device, means for identifying whether the predetermined time based on said time meter apparatus, being received Radio data transmitted from a broadcasting station
Means for correcting the time of the clock unit with clock data in the data of the data multiplex broadcasting system, the alternative frequency by the alternative frequency Sir <br/> Chi means when said identification means has identified that the predetermined time in-vehicle radio receiver and means for prohibiting the search operation, the radio data
Means for confirming whether there is time data in the data of the data multiplex broadcasting system, and the prohibiting means only when the confirming means confirms that the time data exists. Activating means.

[0007]

[Action] by radio data multiplex broadcasting system of the data at the alternative frequency search function and automotive radio receiver having a clock calibration function, only when receiving the data when the alternative frequency search disabled state prohibiting alternative frequency search operation , Whenever the data is not received
Alternative frequency search can be performed and smooth alternative frequency
A number search start check process can be performed.

[0008]

FIG. 1 is a block diagram showing an embodiment of an on-vehicle radio receiver according to the present invention. In FIG. 1, 1
Is an antenna, 2 is a PLL receiving circuit, 3 is a muting circuit, 4 is a microcomputer (hereinafter referred to as a microcomputer), 5 is an RDS data demodulating circuit, 6 is a receiving sensitivity detecting circuit, 7 is a memory, 8 is a display, and 9 is a display. PS (Program Servi
ce Name) display, 10 is a key input circuit, and 11 is a clock device. In FIG. 1, when a broadcast signal including RDS data from a broadcasting station is input from an antenna 1 to a PLL receiving circuit 2, a microcomputer 4 detects a reception signal by a reception sensitivity detection circuit 6, for example, when the reception signal is detected by an S meter output. 20dB strength
μV or more and noise level at IF output is 1.5V
When a detection signal that satisfies the following reception conditions is output,
The muting circuit 3 is controlled to a non-operating state to output a demodulated audio signal. However, if the reception condition is not satisfied, no detection signal is generated from the reception sensitivity detection circuit 6, and the microcomputer 4 sets the muting circuit 3 to the operating state to cut off the audio signal.

Further , the microcomputer 4 takes in the RDS data signal included in the received signal from the PLL receiving circuit 2 via the RDS data demodulating circuit 5 and stores it in a memory 7 such as a RAM. The display 8 displays the reception frequency and the time under the control of the microcomputer 4 , and the PS display 9
Displays the name of the receiving broadcast station under the control of the microcomputer 4 in the same manner. The key input circuit 10 can selectively perform each function operation at the time of reception by a predetermined key operation.
The clock device 11 can adjust the time by adjusting the time under the control of the microcomputer 4 with the CT data in the RDS data transmitted from the receiving broadcasting station, and display the time on the display 8. Is done.

FIG . 2 is a flowchart for explaining the operation of the block diagram of FIG. First, it is checked whether or not the RDS data received in step S1 includes CT data.
If the answer is yes, it is confirmed whether or not the clock device 11 is in an undetermined state ( step S2).
It is checked whether the second is, for example, not less than 58 seconds and not more than 1 second .
Step S3) The second of the clock device is 58 seconds, 59 seconds, 0 seconds,
When the time is 1 second, the AF search operation is disabled and the AF search operation is prohibited ( step S4).
Calibration (correction) is performed using T data ( step S5). on the other hand,
If NO in steps S1, S2, S3, an AF search start check is performed.

As described above, by checking whether or not CT data is input, the means for inhibiting the AF search operation is activated only when CT data is input. In the case of a station that does not transmit data, an AF search start check can always be performed. It should be noted that the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, when identifying whether or not it is a predetermined time based on a clock device, the predetermined time is set to “58 seconds or more and 1 second or less” in the above embodiment, but is not limited thereto. "55 seconds or more and 5 seconds or less" can be appropriately set.

[0012]

According to the on-vehicle radio receiver according to the present invention, when the receiving broadcasting station does not transmit the time data, it is possible to reduce the time.
The alternative frequency search invalid state is eliminated, and a smooth alternative frequency search start check process can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a vehicle-mounted radio receiver according to the present invention.

FIG. 2 is a flowchart illustrating the operation of the block diagram of FIG. 1 according to one embodiment of the present invention.

FIG. 3 is a flowchart illustrating the operation of a conventional in-vehicle radio receiver.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Antenna 2 PLL receiving circuit 3 Muting circuit 4 Microcomputer 5 RDS data demodulation circuit 6 Reception sensitivity detection circuit 7 Memory 8 Display 9 PS display 10 Key input circuit 11 Clock device

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B 1/16 H03J 7/18

Claims (1)

(57) [Claims] 1. The data of a radio data multiplex broadcasting system.
An on-vehicle radio receiver having a receiving function of receiving data , a substitute frequency search unit, a clock device, and a unit for identifying whether or not a predetermined time is determined based on the clock device; Radio data transmitted from a broadcasting station
Means for correcting the time of the clock device with clock data in the data of the data multiplex broadcasting system, and the alternative frequency search means when the identification means identifies that the time is a predetermined time. in alternative frequency search operation vehicle radio receiver and a means for inhibiting, data of the radio
And means for confirming whether there is data at the time during data over data multiplex broadcasting system, only when the time of de <br/> over data it was confirmed that by the confirming means, the prohibition Means for activating the means.