JPH0683092B2 - Radio receiver - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio receiver, and more particularly, to a signal to be originally received, for example, an audio signal in radio broadcasting and the content of the signal to be originally received, for example, a broadcasting station. It is suitable for use in so-called radio data systems (RDS), etc. in which code signals representing the contents of programs, programs, etc. are transmitted at the same time, so that desired signals that should be originally received can be displayed acoustically or visually. New radio receivers.

Prior Art A typical prior art is a radio receiver with a Phase Locked Loop (PLL) frequency synthesizer. In this prior art, a high frequency signal of a broadcasting station having a predetermined electric field strength or more is received by so-called auto tuning. The operator can select a desired broadcasting station by selecting from the received signals, and the tuning operation is easy.

Problems to be Solved by the Invention In such a prior art, desired program contents such as news and sports cannot be selectively heard. Also, as the number of broadcasting stations increases, many signals are received, and it becomes difficult to easily select a desired program.

In particular, in a radio receiver mounted on a car, the frequency that can be received by the same program is changed because the broadcasting station is changed with the movement of the area, and it is necessary to retune each time. From the viewpoint of facilitating tuning operation and improving safety, it would be convenient if not only automatic frequency selection function such as so-called auto tuning but also program content or program selection can be performed.

An object of the present invention is to solve the above problems and improve operability,
It is an object of the present invention to provide a radio receiver capable of accurately and quickly selecting and receiving a signal to be originally received such as a desired broadcasting station or program.

Means for Solving the Problems The present invention provides a code for identifying a radio broadcasting network.
The card-shaped store means 1, 16 and 17 for storing PI and the store means 15, 16 and 17 are detachably mounted, and the means 13 for reading the stored contents and the frequency of the output of the read means 13 Among the radio broadcasts scanned and received with the electric field strength higher than a predetermined value, the radio having the same identification code PI stored in the storing means 15, 16, 17 and the maximum electric field strength S _M And a means 9 for detecting and receiving a broadcast.

Operation According to the present invention, therefore, the card-shaped store means 15, 16 and 17 are removably attached to the reading means 13, whereby the store means 1 is provided.
The code PI for identifying the radio broadcasting network stored in 5, 16, 17 is read, and the frequency is automatically scanned when read in this way, and the same identification code PI is read.
Since the radio broadcast having the maximum electric field strength S _M is received, it is possible to select the radio broadcast accurately and quickly by a simple operation by exchanging different store means 15, 16 and 17. This is useful for improving safety, especially when the radio receiver of the present invention is used by being installed in an automobile or the like.

Embodiment FIG. 1 is a block diagram of a radio receiver 20 according to an embodiment of the present invention. Broadcast waves from a plurality of broadcasting stations are received by an antenna 14, are received by a super heterodyne system, and are converted into sound by a speaker 6 which is a display means.

For example, in the card-shaped store means 15, 16 and 17 formed of a read-on memory, the stored contents are read by the read means 13 and output to the control circuit 9 which is the comparison means. By these store means 15, 16 and 17, a desired broadcasting station can be selected and listened to.

A carrier wave from a radio broadcasting station is received by an antenna 14 and given to a high frequency amplification mixing circuit 1 which performs high frequency amplification and mixing. The high frequency amplification mixing circuit 1 comprises a phase locked loop frequency synthesizer, and the reception tuning frequency and the local oscillation frequency are set by a control signal from a control circuit 9 via a line 19.

The output from the high frequency amplification mixing circuit 1 is given to an intermediate frequency amplification detection circuit 2 which performs intermediate frequency amplification and also performs detection such as frequency discrimination. The signal from the intermediate frequency amplification detection circuit 2 is given to a separation circuit 3 and separated into left and right acoustic signals of stereo broadcasting. The acoustic signal from the separation circuit 3 is given to an adjustment circuit 4 which performs sound quality adjustment and volume adjustment.

The adjusting circuit 4 suspends the derivation of the acoustic signal by the mute signal provided from the control circuit 9 via the line 18. The acoustic signal from the adjustment circuit 4 is power-amplified by the power amplification circuit 5 and sonicated by the speaker 6.

The output from the intermediate frequency amplification detection circuit 2 is also given to a bandpass filter (hereinafter referred to as BPF) 7, and further given to the control circuit 9 via the demodulation circuit 8. The operation state of the control circuit 9 is controlled by the drive circuit 10. Displayed by the driven display 11. The display 11 is composed of liquid crystal, for example.

A signal input from the key input unit 12 is given to the control circuit 9 so that the receiving operation can be manually operated.

FIG. 2 is a diagram showing the insertion port 21 and the storing means 15, 16, 17 of the radio receiver 20 shown in FIG. Radio receiver
An insertion opening 21 for the storing means 15, 16, 17 is formed in the storage means 20, and the storing means 15, 16, 17 can be selectively inserted into and removed from the insertion opening 21.

FIG. 3 is a diagram showing a frequency spectrum of a modulated wave for modulating a carrier wave received by the radio receiver 20 from a plurality of radio broadcasting stations. For stereo broadcasting, this modulated wave contains an L + R signal 23 which is the sum of left (L) and right (R) audio signals at a frequency of 15 kHz or less. The pilot signal 24 having a frequency of 19 kHz indicates the presence or absence of stereo broadcasting. The separation circuit 3 separates the left and right audio signals of the stereo broadcast when the pilot signal 24 is being transmitted.

A signal 32a and a signal 32b which are left and right audio signals by a suppressed carrier wave 25 which is a high frequency signal having a frequency of 38 kHz which is twice as high as that of the pilot signal 24 (collectively referred to as LR signal 32).
Is included in the frequency band of 23 kHz to 53 kHz as a sideband.

For example, the code signal transmitted by the above-mentioned RDS has a frequency of 5
It is distributed as sideband signals 35 and 36 on both sides of the 7 kHz subcarrier 34. The output from the intermediate frequency amplification detection circuit 2 has a frequency of 57
Given to BPF7 that wave signal with frequency around kHz,
Sideband signals 35, 36 are waved, pilot signals 24, L +
The R signal 23 and the L-R signal 32 are removed.

The demodulation circuit 8 demodulates the sideband signals 35 and 36 to derive a code signal as shown in FIG. This code signal is given to the control circuit 9. This code signal is for example RDS
, Each group consists of 104 bits, and each group consists of 26 bits.
It consists of two blocks. One block consists of a 16-bit information word and a 10-bit check word, and the check word is for detecting / correcting an error.

There are several types in this group, and various types of information are transmitted depending on the types. FIG. 4 (1) is a diagram showing codes common to all groups. The 16-bit information word in the first block is called the PI code. The first 4 bits indicate the country of the broadcasting station, and the next 4 bits indicate the region where it is broadcast.
The last 8 bits represent the reference number of the program and are the identification code of the program as a whole. Usually, broadcasting stations on the same network broadcast the same program, and the same PI code is transmitted.

The 5th bit from the 7th bit to the 11th bit of the second block is called a PTY code and is a code relating to the program content as shown in Table 1.

As shown in FIG. 4 (2), the last 2 bits of the information word of the second block and the 16 bits of the information word of the fourth block represent the broadcasting station name called PS code in some groups. The character code is placed.

The radio receiver 20 of the present embodiment receives such a code signal, compares it with the identification signal stored in the storing means 15, 16 and 17, and automatically broadcasts such that both signals match. The operation of the radio receiver 20 will be described for the case of selecting a channel and storing the identification signal corresponding to the PI code in the storing means.

The operator selects one of the store means 15, 16 and 17 in which the PI code of the desired broadcasting station is stored and inserts it into the insertion port 21 provided in the radio receiver 20. The reading means 13 reads the PI codes of the inserted storing means 15, 16, 17 and outputs them to the control circuit 9. The control circuit 9 sends the mute signal of the adjusting circuit 4,
After pausing the audio output, scan from the minimum tuning frequency to the maximum tuning frequency. At each frequency to be scanned, the PI code demodulated with respect to the broadcast received with a field strength equal to or higher than a predetermined value is compared with the identification code output from the reading means 13, and both codes match, In addition, the frequency and field strength of the tuned broadcast are stored when the highest field strength has been received since the start of scanning. When scanned up to the maximum tuning frequency, it is tuned to the broadcast of the stored frequency, that is, the program having the highest electric field strength and corresponding to the PI code stored in the storing means 15, 16, 17. After this, the muting operation is released and audio output is performed.

By the above operation, the desired broadcast can be stored in the storing means 15,1
It is possible to receive by simply applying 6, 17 to the reading means 13. In this embodiment, since the channel is selected by the PI code, it is possible to immediately receive the desired broadcast even if the reception frequency is unknown. Further, in a mobile body such as an automobile, the above-described scanning operation is automatically performed even when the electric field strength of the received broadcast falls below a certain level, and the transmitting station of the same program having a higher electric field strength is different. It is also possible to receive a signal transmitted from the device, that is, a signal having a different frequency. At this time, for example, the driver only sets the store means 15, 16 and 17, so that the safety is remarkably improved as compared with the conventional receiving method which requires many operations.

In the present embodiment, a recording medium such as a so-called RAM card or magnetic card can be used as the storing means in addition to the card-shaped read-only memory. In addition, a broadcast in which a signal similar to the PI code is multiplexed can be applied to AM broadcast and TV broadcast, and the present invention can be implemented regardless of the signal modulation system.

As described above, according to the present invention, the card-shaped store means 1
5, 16 and 17 are exchanged and the reading means 13 reads the code PI which is the content stored therein, whereby the same code as the radio broadcasting network represented by the code PI stored in the storing means 15, 16 and 17 is read. Moreover, it is possible to detect and receive the radio broadcast having the maximum electric field strength S _M in the receivable frequency range. As a result, a desired radio broadcast can be accurately and quickly selected and received, which is important from the viewpoint of improving safety, especially in a radio receiver mounted on a vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a radio receiver 20 according to an embodiment of the present invention, and FIG. 2 is an insertion port of the radio receiver 20 shown in FIG.
21 and store means 15, 16 and 17, FIG. 3 is a diagram showing a frequency spectrum of a modulated wave for modulating a carrier wave received from a plurality of radio broadcasting stations by a radio receiver 20, FIG. FIG. 3 is a diagram showing an example of the structure of a code signal representing the content of a signal to be originally received. 6 ... speaker, 8 ... demodulation circuit, 9 ... control circuit, 11
...... Display, 13 ...... Reading means, 15 to 17 …… Store means,
20 …… Radio receiver, 21 …… Insertion port

Claims (1)

[Claims] 1. Card-shaped store means 15, 16 and 17 for storing a code PI for identifying a radio broadcasting network, and store means 15, 16 and 17 are detachably mounted and a means 13 for reading the stored contents. In response to the output of the reading means 13, the frequency scan, and the identification code PI stored in the storing means 15, 16 and 17 among the radio broadcasts received with the electric field strength of a predetermined value or more, Radio receiver including means 9 for detecting and receiving radio broadcasts having the same maximum electric field strength S _M.