JP2980137B2 - Receiving machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver using RDS data.

[0002]

2. Description of the Related Art Some FM broadcasting stations in Europe add RDS data to an original audio signal.

[0003] The RDS data is a collection of digital data related to broadcast stations and programs, and the RDS data includes an AF list デ ー タ a frequency list of broadcast stations on the same network. PI code @ program identification code. Country code,
It has a program code and the like. TP data @ When this is "1", the broadcast station is broadcasting traffic information. Such data is included.

Then, the RDS data is subjected to an encoding process for error correction, and the RDS data subjected to the encoding process has a frequency of 57 kHz (this is a value three times the frequency of the stereo pilot signal of 19 kHz). The subcarrier signal is balanced-modulated, and the modulated signal is added to a monaural signal or a stereo composite signal and frequency-multiplexed, and the multiplexed signal is transmitted by an FM wave.

Therefore, by using the RDS data, it is possible to receive a specific broadcast station or a specific program,
Traffic information and the like can be obtained.

[0006] Hereinafter, a broadcasting station that also transmits RDS data is called an "RDS station", and a broadcasting station whose TP data is "1" (a broadcasting station that broadcasts traffic information) is called a "TP station".

Reference: "Nikkei Electronics" August 1987
March 24 issue

[0008]

According to the present invention, when an auto preset key is pressed, FM broadcasting stations (including RDS stations) are automatically preset.

[0009] Only the RDS station (including the TP station) is automatically preset.

[0010] Only the TP station is automatically preset. Is intended to be provided.

[0011]

Therefore, in the present invention, if the reference numerals of the respective parts correspond to the embodiments described later, the receiving circuits 1 to 9 of the synthesizer system and the receiving circuits 1 to 9 A demodulation circuit 25 for demodulating RDS data from a broadcast wave signal, a decoder circuit 26 for performing decoding processing such as error correction on the RDS data from the demodulation circuit 25, a memory 34, and a first to a third mode. A designated mode switch Km, an auto preset key Kp, and a plurality of tuning keys K1 to Kn are provided. When the mode switch Km is set to the first mode, the mode switch Km is determined according to the presence or absence of a broadcast wave signal. Is set to the second mode, it is determined that the mode switch Km is set to the third mode depending on whether there is an error in the RDS data. Is written into the memory 34 in accordance with the TP data, and when the tuning keys K1 to Kn are operated, the data N is written from the address corresponding to the operated tuning key in the memory 34. The received data N is read, and the receiving frequency fr of the receiving circuits 1 to 9 is set based on the read data N.

[0012]

When the mode switch is set to the first mode, the FM station performs auto-preset. When the mode switch is set to the second mode, the RDS station performs auto-preset. When the switch is set to the third mode, TP
The station is auto-preset.

[0013]

In FIG. 1, a receiving circuit is constructed in a synthesizer system, 1 is an antenna, 2 is an antenna tuning circuit of an electronic tuning system, and this tuning circuit 2 is used for FM broadcast of a target frequency fr. The wave signal Sr is extracted.

The signal Sr is supplied to the high-frequency amplifier 3
Through the VCO 1
An oscillation signal So having a frequency fo of, for example, fo = fr + 10.7 MHz / (i) is extracted from 1 and this signal So is supplied to the mixer circuit 4 as a local oscillation signal, and the signal Sr is an intermediate frequency signal Si ( The intermediate frequency is converted to 10.7 MHz). Then, the intermediate frequency signal Si is supplied to the FM demodulation circuit 6 through the intermediate frequency amplifier 5 and the audio signal (monaural signal or stereo composite signal) S
a and the modulated signal Sm modulated by the RDS data are taken out, and the signal Sa is supplied to the speaker 9 through the low-pass filter 7 and the low-frequency amplifier 8.

At this time, the VCO 11 is connected to the circuit 1
Together with 2 to 15, the PLL 10 is configured. That is, the signal So from the VCO 11 is supplied to the variable frequency dividing circuit 12 and divided into a frequency of 1 / N. The frequency divided signal is supplied to the phase comparing circuit 13 and the oscillation circuit 1
An oscillation signal Sp having a frequency of 100 kHz as a reference is extracted from 4, and this signal Sp is supplied to a comparison circuit 13, and its comparison output is supplied to the VCO 11 through a low-pass filter 15 as its control voltage. The output voltage of the filter 15 is supplied to the tuning circuit 2 as a tuning voltage.

Therefore, in a steady state, the frequency of the frequency-divided signal from the frequency-dividing circuit 12 and the oscillation signal Sp are equal, and the frequency fo of the oscillation signal So at this time is fo = 100 kHz × Nｋ ‥ (ii). At this time, equation (i) holds.

Therefore, as shown in FIG.
Is changed in steps of "1" between 982 and 1187, and the local oscillation frequency fo is set to 0.9 when the local oscillation frequency is between 98.2 MHz and 118.7 MHz.
Since it changes at intervals of 1 MHz, the reception frequency fr is 87.5
The frequency band from MHz to 108.0 MHz changes in 0.1 MHz frequency steps and in accordance with the frequency division ratio N.

Reference numeral 30 denotes a microcomputer for controlling the system, 31 denotes its CPU, 32
Is a ROM in which the processing routine 50 shown in FIGS. 3 and 4 is written, 33 is a RAM for a work area,
4 is a RAM for storing various data, 41 to 44
Are ports, these memories 32-34 and ports 41-
Reference numeral 44 is connected to the CPU 31 through the system bus 36.

The port 41 is connected to the frequency dividing circuit 12, and a program described later is executed to set the frequency dividing ratio N in the frequency dividing circuit 12. Although not shown, the RAM 34 is backed up by a battery and is made non-volatile, and retains the written data even when the power is turned off.

Further, a part of the FM demodulated output and the intermediate frequency signal Si is supplied from the demodulation circuit 6 to the detection circuit 23, and the reception level of the broadcast wave signal Sr is higher than a specified value and the broadcast wave signal Sr A tuning detection signal Sq which is "1" when the tuning is correct and "0" otherwise is taken out, and this signal Sq is supplied to the port 42.

The signals Sa and Sm from the demodulation circuit 6 are supplied to a band-pass filter 24 to extract the signal Sm. The signal Sm is supplied to a demodulation circuit 25 and the RDS
The data Sd is demodulated, and the RDS data Sd is supplied to the decoder circuit 26 to perform error correction, and then supplied to the port 42. At this time, the decoder circuit 2
6 to the signal Se indicating the result of the error correction of the RDS data Sd.
That is, the RDS output from the decoder circuit 26
An error flag Se indicating whether there is an error in the data Sd is extracted, and this signal Se is also supplied to the port 42.

Further, a port 43 is connected to a mode switch Km and an auto preset key Kp, and a port 44 is connected to channel selection keys K1 to Kn (n is, for example, 10).

In this case, the mode switch Km is used to select one of the following modes when performing auto presetting. Also, keys Kp and Ki (i = 1 to n)
Are each configured by a non-locking type push switch. And the auto preset key Kp is
When the button is pressed, the preset is automatically performed in accordance with the mode selected by the mode switch Km. Further, the tuning key Ki is for selecting a broadcasting station preset to the key when the key is pressed.

It is assumed that the tuning key Ki corresponds to the address Ai of the RAM 34, and the frequency division ratio N of the broadcasting station preset in the tuning key Ki is stored in the address Ai.

Reference numeral 45 denotes a display controller;
Reference numeral 46 denotes a display device, which digitally displays a reception frequency and the like.

According to such a configuration, the following processing is performed by the CPU 31 executing the routine 50 in FIGS.

Turning on the power supply When the power supply is turned on, the processing of the CPU 31 is executed in a routine 50.
Starting from step 51, and then in step 52, the data of the last channel, that is, the frequency division ratio N of the broadcast station that was received when the power was last turned off, is
The frequency is read from a predetermined address A0 of the RAM 34, and the frequency dividing ratio N is set in the frequency dividing circuit 12 in the next step 53.

Therefore, when the power is turned on, the broadcasting station that was received when the power was last turned off is received.

Subsequently, the processing of the CPU 31 proceeds to step 53.
To step 61, and in this step 61,
It is checked whether or not there is an input from the keys Kp and Ki.
And wait for key input.

◎ Key input In step 61, if any key of the keys Kp and Ki is pressed while waiting for key input, the process proceeds from step 61 to step 62. It is checked whether or not the key input by is the preset key Kp. If the key is not the preset key Kp, that is, if the key is the tuning key Ki, the process proceeds from step 62 to step 69. In this step 69, the following process is executed.

選 Tuning by Tuning Keys K1 to Kn A broadcasting station (general FM station, RDS station, TP
If any of the stations is preset, and the user presses an arbitrary tuning key Ki in step 61, the address Ai corresponding to the pressed key Ki in the RAM 34 is displayed there. The division ratio N of the broadcast station that has been written is read out, and the division ratio N is set in the division circuit 12. After this tuning, the frequency division ratio N is stored in RAM
The data is written to the predetermined address A0 at 34 as last channel data.

Therefore, by this key operation, it is possible to select a broadcasting station preset in the tuning keys K1 to Kn.

As described above, in step 69, the channel is selected by the channel selection keys K1 to Kn.

When the process of step 69 is completed, the process returns to step 61 and waits for a key input again.

Auto preset of FM station (including RDS station) In this case, the mode switch Km is set to the switching position and the auto preset key Kp is pressed.

Then, the process proceeds from step 61 to step 62, but the key input in step 61 is the key K
Therefore, the process proceeds from step 62 to step 71. In this step 71, the pointer i designating the tuning key Ki is set to the initial value 1, and the dividing ratio N of the dividing circuit 12 is set to the minimum value 982. Is set to

Therefore, when the preset key Kp is pressed, the receiving frequency is first set to the minimum receiving frequency of 87.5 MHz.

Then, the process proceeds to a step 72, wherein
In this step 72, the tuning detection signal Sq
It is checked whether the reception level is tuned to a broadcast wave equal to or higher than a specified value. When the reception level is tuned to such a broadcast wave, the process proceeds from step 72 to step 73,
In this step 73, the switching position of the mode switch Km is checked, and in this case, since it is the switching position, the process proceeds from step 73 to step 81.

In step 81, the current frequency division ratio N is written to the address Ai of the RAM 34 indicated by the pointer i. Therefore, the reception frequency fr determined by the current frequency division ratio N is set to the i-th tuning key Ki.

Subsequently, the process proceeds from step 81 to step 82. In this step 82, the pointer i is incremented by "1", and in step 83, the dividing ratio N of the frequency dividing circuit 12 is increased by "1". Increment is performed, and it is checked in step 84 whether the frequency division ratio N has exceeded the maximum value 1187. If not, the process returns from step 84 to step 72.

If it is determined in step 72 that the reception level is not tuned to the broadcast wave whose level is equal to or higher than the specified value, the process proceeds from step 72 to step 83.

Therefore, after that, step 72 (→ 73)
→ 81 → 82) → 83 → 84 are repeated to scan the reception frequency band of FIG. The data is written to the address Ai, that is, the broadcasting station is preset to the tuning key Ki. This preset is performed for FM stations regardless of whether they are general FM stations or RDS stations.

When the frequency division ratio N exceeds the maximum value in step 84, the process returns from step 84 to step 52, and after the last channel is selected,
Step 61 waits for a key input again.

When the auto preset key Kp is pressed while the mode switch Km is at the switching position, the FM station is preset to the tuning key Ki.

In this case, the mode switch Km is set to the switching position and the auto preset key Kp is pressed.

Then, the process proceeds from step 61 to step 73 in the same manner as
In step (3), the switching position of the mode switch Km is checked. In this case, since the switching position is, the process proceeds from step 73 to step 74.

In this step 74, RD
By checking for the presence or absence of S data Sd, RDS
It is determined whether or not a broadcast station transmitting the data Sd has been selected. If the result of this check is that an RDS station has been selected, the processing proceeds from step 74 to step 75.
And in this step 75, the error flag Se
Is checked.

In this case, if a reception failure such as RF intermodulation or multipath has occurred in the currently selected broadcasting station, or if the reception level is so low that it is not suitable for receiving RDS data, the RDS There is a possibility that an error has occurred in the data Sd, and the error flag Se indicates this.

Therefore, as a result of this check, if the error flag Se indicates that no error has occurred, the RDS data Se is valid, and the currently selected broadcasting station is the RDS station. And it is regarded as suitable for reception, and the processing is performed from step 75 to step 76.
Proceed to.

Then, in this step 76, the switching position of the mode switch Km is checked. In this case, since the switching position is, the processing proceeds from step 76 to step 81.

Therefore, in the same manner as in the following, the i-th tuning key Ki is determined in steps 81 to 84.
Then, the reception frequency fr determined by the current frequency division ratio N is set, and then the process returns to step 72.

If the received broadcast station is not an RDS station in step 74, the process proceeds to step 74.
To step 83. Further, in step 75, when the error flag Se indicates that an error has occurred, the processing is continued from step 75 to step 83.
Proceed to.

Therefore, steps 72-76, 81-
When the reception frequency band of FIG. 2 is scanned by R84 and an RDS station whose reception level is equal to or higher than a specified value is found, the frequency division ratio N giving the reception frequency fr is written into the address Ai of the RAM 34, that is, the RDS The station is preset to the tuning key Ki.

Thus, when the mode switch Km is at the switching position, when the auto preset key Kp is pressed, only the RDS station is preset to the channel selection key Ki.

In this case, the mode switch Km is set to the switching position, and the auto preset key Kp is pressed.

Then, the process proceeds from step 61 to step 76 in the same manner as
In step, the switching position of the mode switch Km is checked. In this case, since the switching position is, the process proceeds from step to step 77.

Then, in this step 77, RD
The TP data of the S data Sd is checked, and if it is a TP station ("1"), the process proceeds from step 77 to step 81.

Therefore, in the same manner as in the following cases, the i-th tuning key Ki is set in steps 81 to 84.
Then, the reception frequency fr determined by the current frequency division ratio N is set, and then the process returns to step 72.

If it is determined in step 77 that the received broadcast station is not a TP station (when it is "0"), the process proceeds from step 77 to step 83.

Therefore, steps 72-77, 81-
84, the receiving frequency band is scanned, and if a TP station having a receiving level equal to or higher than a specified value is found, the receiving frequency f
The frequency dividing ratio N giving r is written to the address Ai of the RAM 34, that is, the TP station is preset to the tuning key Ki.

When the auto-preset key Kp is pressed while the mode switch Km is at the switching position, only the TP station is preset to the tuning key Ki.

Thus, according to the present invention, when the auto preset key Kp is pressed, the mode switch K at that time is pressed.
The FM station, the RDS station or the TP station is preset to the tuning key Ki corresponding to the switching position of m.

In the above description, when more than the number n of the channel selection keys K1 to Kn are found by scanning the reception frequency band, the upper n stations having a higher reception level are selected as the channel selection keys. Ki can be preset. That is, in this case, step 71
Each time a target broadcast station is found by using the above-described method, the frequency division ratio N and the data indicating the reception level at that time are represented by R
The frequency division ratios N stored in the AM 33 and stored in the RAM 33 upon completion of scanning are sorted in descending order of the reception level, and the frequency division ratios N of the upper n stations of the sorting result are sequentially assigned to the channel selection key Ki. You only need to register.

[0064]

According to the present invention, when the auto-preset key Kp is pressed, the FM station, the RDS station or the TP station is preset to the tuning key Ki corresponding to the switching position of the mode switch Km at that time. be able to.

Further, in the case of (1), the broadcast without error in the RDS data Sd is regarded as a valid RDS station in step 75 and presetting is performed.
Preset of the DS station or the TP station can be reliably performed.

That is, when the modulated signal Sm is detected during scanning of the RDS station, the presetting can be performed. In this case, when the quality of the RDS data Sd is poor due to a reception failure such as multipath, the presetting is performed. Even if the selected RDS station is selected, there is a problem that the RDS data cannot be used. However, in the above, the RDS station or TP station is preset only when it is confirmed that there is no error in the RDS data Sd in step 75. Therefore, only the valid RDS station or TP station is preset. be able to.

Further, before confirming that there is no error in the RDS data Sd in step 75, step 7
In 2, 74, the presence or absence of the broadcast wave signal and the RDS data S
The presence or absence of d is checked, and the error of the RDS data Sd is checked only when these checks are passed, so that a valid RDS station or TP station can be quickly found.

[Brief description of the drawings]

FIG. 1 is a system diagram of an example of the present invention.

FIG. 2 is a diagram for explaining a reception frequency.

FIG. 3 is a flowchart showing a part of an example of processing contents of the present invention.

FIG. 4 is a flowchart showing a part of an example of processing contents of the present invention.

[Explanation of symbols]

 2 Antenna tuning circuit 4 Mixer circuit 6 FM demodulation circuit 9 Speaker 10 PLL 11 VCO 12 Variable frequency dividing circuit 13 Phase comparison circuit 15 Oscillation circuit 23 Detection circuit 25 Demodulation circuit 26 Decoder circuit 30 Microcomputer 31 CPU 32 ROM 33, 34 RAM 41 To 44 ports 45 display controller 46 display device 50 processing routine Km mode switch Kp auto preset key K1 to Kn tuning key

Claims (1)

(57) [Claims] 1. A receiving circuit of a synthesizer system, a demodulating circuit for demodulating RDS data from a broadcast wave signal received by the receiving circuit, and a decoder for performing a decoding process such as an error correction on the RDS data from the demodulating circuit. A circuit, a memory, a mode switch for designating the first to third modes, an auto preset key, and a plurality of channel selection keys. When the mode switch is set to the first mode, When the auto preset key is operated, the receiving frequency of the receiving circuit is changed for each predetermined frequency step to scan a broadcast frequency band, and when the broadcast wave signal is received by this scan, the receiving frequency is changed. The given data is written to the memory, and when the mode switch is set to the second mode, the automatic preset When the key is operated, the receiving frequency of the receiving circuit is changed for each of the predetermined frequency steps to scan the broadcast frequency band. When the RDS data is received by this scanning, the received RDS data is received.
The DS data is checked for errors, and as a result of the check, if no error has occurred in the received RDS data, data giving the frequency at that time is written to the memory, and the mode switch is set to the third mode. When the auto-preset key is operated, the receiving frequency of the receiving circuit is changed for each of the predetermined frequency steps to scan a broadcast frequency band, and when the RDS data is received by this scanning, Check the received RDS data for errors,
If there is no error in the received RDS data as a result of this check, the TP data included in the RDS data is checked. Is written in the memory, and when the tuning key is operated, the written data is read from an address corresponding to the operated tuning key in the memory, and the reception is performed based on the read data. A receiver in which the receiving frequency of a circuit is set to the receiving frequency when the data is written.