JPH0470126A - Receiver - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to receivers, particularly vehicle radio receivers.

Conventional technology Traditionally, radio receivers installed in automobiles have
When the received electric field strength of the radio broadcast station being received decreases while the vehicle is running, the driver operates a key switch of the radio receiver to receive a new broadcast station. For example, in so-called electronically tuned radio receivers that use a phase-locked loop frequency synthesizer, manual tuning is performed by operating the up/down keys to raise or lower the reception frequency, and tuning is done manually by operating the up/down keys to raise or lower the reception frequency. When a radio broadcasting station with a reception field strength higher than the specified one is received, operate the auto-tuning key switch, such as seek, which stops scanning that frequency, or scan, which stops operation for a certain period of time and continues scanning the reception frequency. death,
Further, operations such as reading are performed by operating a preset key switch corresponding to a predetermined reception frequency.

Problems to be Solved by the Invention In such prior art, a driver or the like must operate a key in order to change the receiving frequency, which poses a danger from the viewpoint of traffic safety. Additionally, if you try to find a radio station on another frequency that is broadcasting the same content as the radio station you were currently receiving, you may have to repeat the above key operations, which is not only troublesome but also 5 The degree of risk increases.

An object of the present invention is to provide a receiver that can automatically change the reception frequency of radio waves of high-frequency signals such as radio broadcasts.

Means for Solving the Problems The present invention includes a receiving circuit that receives a high-frequency signal, a receiving field strength detecting means that detects the receiving field strength of radio waves received by the receiving circuit, and storing a plurality of predetermined receiving frequencies. When the received electric field strength detected by the memory and the received electric field strength detection means of the high-frequency signal being received by the receiving circuit becomes less than a predetermined value, the received frequencies stored in the memory are read in a predetermined order. A receiver characterized in that it includes a control means for reading out the information and causing a reception circuit to perform reception at the reception frequency to be received next.

According to the present invention, a plurality of predetermined reception frequencies are stored in the memory, and when a reception circuit is receiving radio waves such as radio broadcasting at one of the frequencies, the reception field strength is When the received electric field strength detected by the detection means becomes less than a predetermined value, the control means causes reception to be performed at the reception frequency to be received next to the current reception frequency among the plurality of reception frequencies stored in the memory. The receiving operation is controlled by a circuit, and the order of changes in the receiving frequency is predetermined. Therefore, when the received field strength of radio waves, such as radio broadcasts, which are currently being received becomes small, reception is automatically performed according to a preset order. Therefore, when the receiver of the present invention is installed in a car, for example, there is no need for the driver or the like to perform any operation to search for the reception frequency, thereby improving safety.

By appropriately selecting the receiving frequencies stored in the memory, it becomes possible to listen to radio broadcasts etc. in which the same broadcast content is being broadcast continuously even if the receiving frequencies are different.

Embodiment FIG. 1 is a block diagram of a radio broadcast receiver according to an embodiment of the present invention, which is mounted on an automobile and includes a phase-locked loop frequency synthesizer.
This is a so-called electronically tuned radio receiver. Radio waves, which are high-frequency signals received by antenna 1, are given to high-frequency amplification port WI2 for reception of single-frequency modulation broadcasting, given to mixing circuit 3 for superheterodyne reception, and also given to reception of amplitude modulation broadcasting. For this reason, it is applied to the mixing circuit 4 for the superheterodyne system.

Oscillation outputs from local oscillation circuits 5 and 6 are applied to the mixing circuit 3.4. The intermediate frequency signals from the mixing circuits 3 and 4 are amplified in the intermediate frequency amplifier circuit 7.8, demodulated in the frequency discrimination circuit 9 and the detection diagram n10, and the acoustic signal is given to the low frequency amplifier circuit 12 from the line 11. The speaker 13 is driven. In the one-chip semiconductor integrated circuit 14, the output of the local oscillation circuit 5 is applied to a divider 5 called a prescaler for frequency division, and is further applied to a frequency divider 16 called a programmable divider for frequency division. , the frequency-divided frequency signal is given to the phase comparison circuit 18 from the line 17.The reference frequency signal from the reference frequency oscillation circuit 20 in the processing circuit 19 realized by a microcomputer etc. is supplied to the phase comparison circuit 18 from the line 17. The one-phase comparator circuit 18 provided via 21 is led out to a signal line 23 having a voltage corresponding to the phase difference between the signals on lines 17 and 21, and is led out from line 25 via a low-pass filter 24. The signal from line 25 changes the capacitance of the voltage-dependent variable capacitance element provided in the frequency modulation amplifier circuit 2 and local oscillation circuit 5, thereby changing the reception frequency.

Similarly, the oscillation output of the local oscillator circuit 6 for receiving amplitude modulation broadcasting is given to the frequency divider 16 and frequency-divided.
It is applied via line 17 to phase comparator circuit 18 . The signal derived from the low-pass filter 24 to the line 25 is applied to the local oscillation circuit 6, and similarly to the local oscillation circuit 5 described above, its oscillation frequency is changed and the receiving frequency is changed.

In this way, a phase-locked loop frequency synthesizer is constructed.

The outputs from the frequency discrimination circuit 9 and the detection circuit 12 are converted into digital values by the analog-to-digital converter 27, and the signal having the voltage corresponding to the received electric field strength is
The signal is applied to the control circuit 28 of the processing circuit 19 . The III control circuit 28 controls the frequency division ratio of the frequency divider 16, and also controls the frequency division ratio of the frequency divider 16.
Controls the frequency division ratio of 5.

A memory 30 is provided in association with the processing circuit 19 . As shown in FIG. 2, this memory 30 is provided with a plurality of (for example, 5) storage areas A to E, and each storage area A to E stores reception frequencies to be changed in this order. has been done. The processing circuit 19 includes a key switch 31 for switching between frequency modulation broadcasting and amplitude modulation broadcasting, manual tuning, and the like.

The radio receiver is installed in a car, and is located at points 32 to 35 along road 37 in the direction of arrow 38, as shown in Figure 3.
When traveling in this order, near each point 32 to 35, the frequencies fA, fB, and fC.

Assume that a radio broadcast is being transmitted using high frequency radio waves at fD and fE. In this case, the storage area A of the memory 30
~E, the frequency f is set by operating the key switch 31.
A~, 71! Store 'E and preset it.

FIG. 4 is a flowchart for explaining the operation of the processing circuit 19. Moving from step a1 to step a2, frequencies fA to fE are stored in the storage areas A to E as described above in the order in which they are desired to be received in the memory 30 as described above, and thus so-called program selection becomes possible in step a3. state.

Next, in step a4, the program reception mode is set by operating the key switch 31. For example, while driving at point 32, radio broadcasting is set at the reception frequency fA stored in the storage area A of the memory 30, and step Receive at a5. The received electric field strength is detected in step a6, and it is determined in step a7 whether the voltage v1 represented by the signal derived from the analog-to-digital converter 27 corresponding to the received electric field strength is less than the predetermined set voltage Vr. When the received electric field strength is large and therefore the voltage V1 corresponding to the received electric field strength is equal to or higher than the set voltage Vr, the receiving state of the frequency fA is continued in step a5.

When the car further travels near point 32, the received electric field strength at frequency fA is small, and the voltage V1
is less than the set voltage Vr, and when it is determined in step a7, in step a8, the next frequency fB to be received is stored in the storage area B of the memory 30.
When receiving frequency modulation broadcasting, the division ratio of frequency dividers 15 and 16 is changed, and when receiving amplitude modulation broadcasting, the division ratio of frequency divider 16 is changed so that the reception frequency of frequency fB is received. Receive radio broadcasts. Furthermore, when the car travels through points 33, 34, and 35, the reception frequency f stored in the storage areas C, D, and E of the memory 30 is
It becomes possible to receive radio broadcasts on c, fD, and fE.

When the same broadcast content is being broadcast at such frequencies fA to fE, people in the car can continuously listen to the same broadcast content.

The present invention can be broadly implemented in connection with not only radio receivers but also other receivers that receive high frequency radio waves.

Effects of the Invention As described above, according to the present invention, when the received field strength of the radio waves being received by the receiving circuit becomes less than a predetermined value, the current receiving frequency among the plurality of receiving frequencies stored in the memory is selected. In a predetermined order from the receiving frequency of
Since the next receiving frequency to be received is read out and then received by the receiving circuit, it becomes possible to automatically change the receiving frequency according to a preset order. Furthermore, by appropriately selecting the reception frequency stored in this memory, it is possible to continue listening to the same broadcast content, such as a radio broadcast, even if two reception conditions change.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention, FIG. 2 is a memory map diagram showing the contents of the memory 30, FIG. It is a flowchart for explaining operation. 1... Ashitena, 2... High frequency amplification circuit, 3.4
Mixing circuit, 5, 6... Local oscillation circuit, 7, 8... Intermediate frequency amplification circuit, 9... Frequency discrimination circuit, 10...
Detection circuit, 12...Low frequency amplification circuit, 13...Speaker. 14...1 chip semiconductor 4A integrated circuit, 15.16...
Frequency divider, 18・Phase comparison circuit, 20・Reference frequency sporadic SF
i'ilN, 24...Low pass filter, 30...Memory, 31...Key switch

Claims (1)

[Scope of Claims] A receiving circuit that receives a high-frequency signal, a receiving field strength detection means that detects the receiving field strength of radio waves received by the receiving circuit, a memory that stores a plurality of predetermined receiving frequencies, and a receiving circuit. When the received field strength detected by the received field strength detection means of the high frequency signal being received by the receiver becomes less than a predetermined value, the received frequencies stored in the memory are read out in a predetermined order, and then 1. A receiver comprising: control means for causing a receiving circuit to perform reception at a receiving frequency to be received.