JP2593077B2 - RDS radio receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] In a radio receiver capable of receiving RDS (Radio Data System) broadcasts, the same switch is used for general reception and RDS broadcast reception, thereby preventing an increase in switches. I do.
Here, the RDS broadcast refers to RDS data multiplexed to the conventional FM broadcast.

[Industrial applications]

The present invention relates to a radio receiver capable of receiving an RDS broadcast.

[Conventional technology]

3 times the frequency (5 kHz) of the FM broadcast pilot signal (19KHz)
An RDS broadcast in which data is multiplexed and transmitted in the (7 KHz) band can be reproduced by an FM radio receiver having a decoder as shown in FIG. If the composite signal from the FM demodulation unit is input to the stereo decoder 1, the audio stereo signal L,
R is reproduced, and this is converted to a 57 KHz band-pass filter (BP
F) When the signal is input to 2, the subcarrier of 57 KHz is reproduced by the carrier regenerator 3 and synchronously detected by the synchronous detector 4. A waveform is obtained when this output is input to a low-pass filter (LPF) 5 having a cutoff frequency of 2.4 KHz. This waveform is input to a two-phase PSK (Phase Shift Keying) signal decoder 6 and a clock regenerator 7.
The clock signal of 1187.5KHz is reproduced by using 57KHz subcarrier together. The two-phase PSK signal decoder 6 alternately extracts the input and its inverted waveform with a clock and integrates the synthesized waveform. Then, a binary waveform is reproduced by slicing the integrated waveform. The internal signal of the differential decoder 8 is obtained by shifting this by a clock. The differential decoder 8 reproduces the RDS code signal by taking the exclusive OR of the signal and the signal obtained by further shifting the signal with a clock. 9 is a data processor for processing the code signal.

The RDS code signal includes various codes in a predetermined format and is repeatedly transmitted. The following table shows typical code names and their contents.

Using the above RDS broadcast, (1) a listener can easily search for a desired program in a short time. (2) The "program service name" of the broadcasting station can be displayed. (3) The in-vehicle receiver can announce a broadcast station or the like by voice synthesis. (4) Only stations broadcasting desired programs such as "News" can be automatically picked up. There are merits such as.

Receiving RDS broadcasts requires different control from general reception. For example, when performing a PTY search, as shown in FIG. 7, a program type to be searched is first determined in step S1. This can be realized by detecting that one of the 32 types of PTY codes (for example, Jazz) is input by switching. Next, when the start switch of the PTY search is pressed (step S2), an IF (intermediate frequency) signal above a certain level is detected, and the PTY code decoded at that time is replaced with the PTY code of the program type determined in step S1. The receiving frequency is changed until they match (steps S3, S4, S5). Eventually, when the PTY code matches, the frequency is fixed to that frequency, and the PTY search ends (step S6). The listener can now select the desired program (in this case,
Jazz) can be heard without knowing the broadcaster name or frequency.

[Problems to be solved by the invention]

Even in the case of the PTY search described above as an example, two switches are required: a switch for inputting a program type (PTY code) and a switch for instructing a search start, and more switches are required to instruct other controls. Becomes However, it is not possible to provide a dedicated switch for RDS broadcast reception in addition to the original switches (UP / DOWN, preset, etc.) of the FM receiver, and there is a drawback in that the operability decreases as the number of switches increases. .

According to the present invention, when a program is selected by using a PTY code of an RDS broadcast, the code is input also as a preset switch for general reception, thereby eliminating the need for a switch dedicated to inputting a PTY code.

[Means for solving the problem]

FIG. 1 is a system configuration diagram of the present invention, in which 11 is an antenna,
12 is a PLL synthesizer type FM tuner, 13 is a PLL (phase lock loop) circuit, 14 is a microcomputer for tuner control, 15 is a display, 16 is a switch operation unit, 17 is a speaker, and other symbols 1-9 is the sixth
Refers to each part described in the figure.

The switch operation unit 16 has a plurality of switches (SW) arranged in a matrix, and includes a plurality of presets.
Select SW to select whether to receive SW or RDS broadcast
Is also included. This select SW is newly provided in the present invention.

[Action]

When the select SW is OFF, there are search, SCAN, preset, etc. In this mode, when one of a plurality of preset SWs is turned on, a frequency setting signal (generally a PLL The circumference ratio) is input to the PLL circuit 13, and the tuning frequency of the FM tuner 12 is set to that of the desired broadcasting station with one touch.

On the other hand, when the select SW is turned ON, the same preset SW becomes the input SW of the PTY code to the computer 9. Various methods for inputting the PTY code using the preset SW are conceivable as in the embodiment described later.

In this way, the preset SW for general reception is changed to the RTY broadcast PTY
Select for mode selection when shared with code input switch
Just providing a switch eliminates the need for a dedicated switch for PTY code input.

Embodiment FIG. 2 is a flow chart showing a first embodiment of the present invention, which shows a program executed by the computer 9 for controlling the RDS system in FIG. In this example and in each of the embodiments described later, 32 types (actually used 17 types) of PTY codes are divided into groups of preset SWs, and the corresponding PTY A code group is selected. Groups can be grouped in chord order or by genre (music, news,
Sports). The method of selecting a desired PTY code from the selected PTY code group differs in each embodiment.

In the example of FIG. 2, if the select switch is turned on when the preset switch is turned on, a corresponding PTY code group is read out (steps S11 and S12). Is incremented within (step S13). This “increment” is to sequentially select the PTY codes in the group, and the selected PTY code
The code is displayed on the display 15 for about one second (step S1
Four). Preset when the desired PTY code is displayed
When the switch is released (step S15), a PTY scan is performed using the PTY code (step S16).

This PTY scan is an extension of the PTY search described in FIG. The latter PTY search ends when the PTY code matches, but the PTY scan pauses at the frequency where the PTY code matches, but in the meantime, if the stop switch is not operated, the frequency change is started again and the same at another frequency Perform the operation of searching for the PTY code.

FIG. 3 is a flowchart of the second embodiment of the present invention, and steps S21 and S22 correspond to steps S11 and S12 in FIG. That is, when one of the preset SWs is pressed while the select SW is on, the corresponding PTY code group is selected. In this example, this PTY code group is displayed on the display 15 (step S23). FIG. 4 (2) shows this display example. This PTY
The code group is selected, for example, by turning on the first preset SW when receiving the FM broadcast shown in FIG.

Preset SW: 1: Music, 2: News, 3: Sports,
4: Education, 5: Drama, PTY codes are assigned by genre.
, The group of PTY codes of the music program is selected, and the program type abbreviations Po, Li,... Are displayed in FIG. 4 (2). The following table shows the full name of each symbol.

Table 2 Po → Pop and Rock Li → Light music Se → Serious music Ja → Fazz Fo → Folk music When the preset SW is turned on in the state of Fig. 4 (2),
Since this is the second operation, it is not the selection of the PTY code group, but the operation of specifying one PTY code from the PTY code group selected in the first operation (steps S24 and S24).
twenty five). For example, when the fifth preset SW is turned on, the PTY code of the program type Fo is selected, and FIG. 4 (3)
Is displayed (step S26). And this PTY
PTY SCAN is performed using the code (step S27). In addition, 1
If the second preset SW operation is not performed within a certain time after the first preset SW operation, the process automatically ends (steps S28 and S29).

FIG. 5 is a flow chart of the third embodiment of the present invention. Steps S31 and S32 are the same as those of the embodiment of FIGS. 2 and 3. However, the preset SW used for group selection is continuously pressed as in the embodiment of FIG. 2, or the second preset SW is used to specify a code in the group as in the embodiment of FIG.
No action is taken. In this example, when a PTY code group is selected in step S32, the PTY SCAN is immediately performed in step S33.
Is started. This SCAN is the lower limit of FM band (70MHZ in Japan)
The scanning is performed from z) to the upper limit (90 MHz), and if a PTY code in the selected group is detected on the way, the SCAN is stopped (steps S34 to S37).

If the program type received by this PTY code is not the desired one, the same preset SW may be turned on again. At this time, the process of FIG. 5 is restarted from the start, but since the SCAN is restarted from the frequency following the previous stop, the next PTY code of the same selected group is selected.
Of course, other preset SWs may be turned on, in which case the first or next stopped PTY code in the corresponding selected group is detected by the PTY SCAN. That is, according to this example, the PTY codes in the PTY group corresponding to the turned on preset SW are sequentially selected every time the turned on preset SW is turned on.

〔The invention's effect〕

As described above, according to the present invention, the preset SW for receiving the FM broadcast can be provided by simply providing the select SW and the PTY of the RDS broadcast.
Since it can be used for code selection, there is an advantage that the number of operation switches of the radio receiver with the RDS broadcast reception function can be minimized.

[Brief description of the drawings]

 1 is a system configuration diagram of the present invention, FIG. 2 is a flowchart of a first embodiment of the present invention, FIG. 3 is a flowchart of a second embodiment of the present invention, and FIG. 4 is a display example of the second embodiment. FIG. 5 is a flowchart of a third embodiment of the present invention, FIG. 6 is a block diagram of an RDS decoding unit, and FIG. 7 is a flowchart of a PTY search.

Claims (1)

(57) [Claims] An FM tuner (12) and said FM tuner (12)
Computer for tuner control (1
4), an RDS decoding unit (2 to 8) for coding an RDS code signal frequency-multiplexed in the composite signal received by the FM tuner (12), and an RDS system for processing the RDS code signal A control computer (9) and a switch operation unit (1
6), the switch operation unit (16) is provided with a select switch for determining whether or not to receive an RDS broadcast, and is used for reading a frequency setting signal stored in a memory when receiving other than an RDS broadcast. An RDS radio receiver characterized in that a preset switch is used to select a program type (PTY) code when receiving an RDS broadcast.