JPH04240913A - Radio receiver - Google Patents

Abstract

PURPOSE:To shorten a scanning time by using a 1st control means so as to use the frequency of a broadcast station stored in a memory and listened to precedingly sequentially as a reception frequency. CONSTITUTION:This receiver is provided with a memory 7 storing the frequency of a broadcasting wave during reception, a detection means 3 detecting a broadcast wave, a 1st control means using the frequency stored in the memory 7 to be a reception frequency sequentially and a 2nd control means using the frequency of a reception band to be the reception frequency sequentially and a driving means driving the 1st control means when a scanning switch 8 is operated and driving the 2nd control means when the frequency stored in the memory 7 is received.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a radio receiver.
In particular, the present invention relates to a radio receiver having a scan function that sequentially changes the reception frequency by operating a scan switch and reproduces the broadcast wave for a certain period of time when a broadcast wave is detected.

0002

2. Description of the Related Art Conventionally, receivers have been used which have a scanning function, that is, a function of sequentially changing the reception frequency until a broadcast wave is detected by operating a scan switch. This function changes the reception frequency one after another,
Since the broadcast waves are reproduced for a certain period of time, it is very convenient for searching for a broadcast station that you wish to listen to, and is particularly useful for car-mounted radio receivers where operability is important.

0003

However, in the scanning operation, it is necessary to sequentially change the receiving frequency for each channel separation (at 0.1 MHz intervals in FM broadcasting) and to determine the presence or absence of broadcast waves. Moreover, the frequencies between broadcasting stations are generally separated to prevent adjacent interference, etc., so when performing a scanning operation, frequency change operations and presence/absence detection of broadcast waves are required for each channel separation frequency in the frequency band. There are problems that take time to be done. Furthermore, simply receiving a frequency where broadcast waves are present does not immediately allow the user to receive the desired broadcast station, and there is a problem that it takes a long time until the desired broadcast station is received.

0004

[Means for Solving the Problems] The present invention solves these problems by sequentially changing the reception frequency by operating a scan switch, and when a broadcast wave is detected, playing back the broadcast wave for a certain period of time. In the radio receiver having a scanning function, the radio receiver includes a memory for storing the frequency of a broadcast wave being received, a detection means for detecting the broadcast wave, and a first control means for sequentially setting the frequencies stored in the memory as the reception frequency. , a second control means for sequentially setting the frequencies of the reception band as the reception frequency; and a second control means for driving the first control means when the scan switch is operated, and after the reception operation of the frequency stored in the memory is performed, the second control means for The present invention is characterized in that a drive means for driving two control means is provided.

[0005]

[Operation] When performing a scanning operation, first, the frequencies of previously listened to broadcast stations stored in the memory are sequentially set as reception frequencies by the first control means, so the number of frequency changes and detection of broadcast waves is reduced. Scan time is shorter. Moreover, since the broadcasting station of the frequency previously listened to is received preferentially, the possibility that the broadcasting station desired to be listened to can be promptly received is increased, and the operability is improved. In addition, when the reception operation at the frequency stored in the memory is completed, the broadcasting station is sequentially searched for all frequencies in the reception band, so even if the broadcasting station you want to listen to is not found at the frequency stored in the memory, There is no loss of scanning functionality.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an embodiment of the present invention, and the following description will be made with reference to this figure. The radio receiver of this embodiment includes an antenna 1, a high-frequency amplification circuit, a mixing circuit that mixes a local oscillation signal from a local oscillation circuit with the output of the high-frequency amplification circuit, and amplifies an intermediate frequency signal frequency-converted by the mixing circuit. a front end 2 consisting of an intermediate frequency amplification circuit;
It consists of a detection circuit 3 which also serves as a converter for converting the output signal from the front end 2 into an audio signal. The audio signal from the detection circuit 3 is amplified by the amplifier 4 and output from the speaker 5. The microcomputer 6 performs various controls of the receiver and controls the receiving frequency. The reception frequency is controlled by outputting a signal instructing the reception frequency to the front end 2. This is to control the oscillation frequency of the local oscillation circuit of the front end 2, and is performed by outputting a frequency division ratio to the variable frequency division circuit in the PLL circuit that constitutes the local oscillation circuit. In addition, the reception operation of the frequency stored in the memory is performed by the RAM.
This is performed by reading and writing frequency information (frequency division ratio, frequency, etc. to be output to the variable frequency divider circuit) stored in (random access memory) 7.

Next, the scanning operation will be explained. The scanning operation is performed by sweeping the receiving frequency and detecting a broadcast wave. [Broadcast wave detection is performed by checking whether the output signal of the front end 2, that is, the output signal of the intermediate frequency amplification circuit, exists (or exceeds a predetermined level). ), the front end 2
Detected by the presence or absence of a signal (called an IFD signal) obtained by a known method of detecting a carrier wave at the receiving frequency, for example, by detecting the output signal of the signal with the detection circuit 3. It continues to demodulate and output broadcast waves by fixing the receiving frequency, and when the operator performs a specific operation while the broadcast waves are being demodulated, reception continues at that frequency. be.

Next, the operation of the microcomputer 6 will be explained. FIG. 2 is a flowchart illustrating the operation of the microcomputer 6 during a frequency change operation, and this process is performed in all cases where the receiving frequency is changed, such as by manual operation. Note that it is preferable to perform this process after the receiving frequency has been changed and when the receiving operation has continued at that frequency for a certain period of time, from the viewpoint of storing the broadcasting station that the operator desires to listen to.

[0009] When the reception frequency is changed by manual operation or the like, a reception operation, that is, control of the reception frequency, prohibition and cancellation of audio reproduction output, etc., are performed in step S1. Next, in step S2, it is determined whether the received frequency is already stored in the RAM 7. If the receiving frequency is not stored, the receiving frequency is stored in step S3. In this case, the reception frequencies are stored in the RAM 7 at addresses corresponding to reception times. For example, if it is possible to store 10 frequencies in addresses 1 to 10 of RAM 7, the frequency information in addresses 1 to 9 is moved to addresses 2 to 10, and the newly received frequency information is stored in address 1 (the frequency information in address 1 is information will be deleted), processing will end. Further, if the receiving frequency is stored in the RAM 7, the process ends, but before that, the address of the stored receiving frequency in the RAM 7 is moved. In other words, so that the frequency being received is stored as the latest received frequency,
Change the frequency storage address. For example, if the frequency being received is stored at address 5, frequency information from addresses 1 to 4 is moved to addresses 2 to 5,
Store the frequency information being received at address 1.

FIG. 3 is a flowchart showing the operation of the microcomputer 6 during a scan operation, and this process is performed when the scan switch is operated. In this embodiment, in order to make the explanation easier to understand, the frequency information is stored in addresses 1 to 10 of RAM 7 in the order of the newest frequency at reception time.
Assume that 0 frequency can be stored.

Step P1 initializes the value N of the address designation register to 1. In step P2, RAM7
Let the frequency stored at address N be the reception frequency. Then, in step P3, it is determined whether there is a broadcasting station. This judgment can be made using the IFD signal mentioned above, but the signal (
S) It can also be determined by comparing a signal called a level signal indicating the level of a carrier wave with a predetermined voltage. Note that this S level signal can be obtained as a detection rectification output of the output signal of the front end 2 (intermediate frequency amplification circuit). If a broadcasting station is detected, the broadcast wave is reproduced for a certain period of time in step P4 (the inhibition of audio reproduction output performed during the frequency changing operation is canceled for a certain period of time), and the process moves to step P5. Also, if it is determined in step P3 that there is no broadcasting station,
In step P5, it is determined whether N is the upper limit value (10),
If it is not the upper limit, N is updated (increased by 1) in step P7, then the process returns to step P2, and the processes of steps P2 to P7 are repeated until N reaches the upper limit (10). Then, when N reaches the upper limit (10), the process moves to step P6, where normal scanning is performed, that is, frequency changing operation at all frequencies (for each channel separation) in the reception frequency band, broadcast wave detection operation, and reproduction of the broadcast wave for a certain period of time. Perform the action and finish the process.

With the above-described configuration, according to this embodiment, when a scanning operation is performed, the previously received broadcast stations stored in the RAM 7 are first received in order from the newest one, and then the broadcast stations in the frequency band are received. Since all frequencies (for each channel separation) are received, scanning operations can be performed quickly and desired broadcast stations can be quickly found.

[0013]

As described above in detail, according to the present invention, when a scanning operation is performed, the frequencies of previously listened to broadcast stations stored in the memory are sequentially set as reception frequencies by the first control means. This reduces the number of frequency changes and broadcast wave detections, resulting in shorter scan times. Also,
Since the broadcasting station of the frequency previously listened to is received preferentially, the possibility that the broadcasting station desired to be listened to can be promptly received is increased, and the operability is improved. In addition, when the reception operation at the frequency stored in the memory is completed, the broadcasting station is sequentially searched for all frequencies in the reception band, so even if the broadcasting station you want to listen to is not found at the frequency stored in the memory, There is no loss of scanning functionality.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the microcomputer 6 during a frequency changing operation.

FIG. 3 is a flowchart showing the operation of the microcomputer 6 during a scan operation.

[Explanation of symbols]

2 Front end 3 Detection circuit 6. Microcomputer 7 RAM

Claims (2)

[Claims] Claim 1: In a radio receiver having a scan function that sequentially changes the reception frequency by operating a scan switch and plays the broadcast wave for a certain period of time when a broadcast wave is detected, the frequency of the broadcast wave being received is changed. memory to remember,
a detection means for detecting broadcast waves; a first control means for sequentially setting the frequencies stored in the memory as the reception frequencies; a second control means for sequentially setting the frequencies of the reception band as the reception frequencies; and a scan switch is operated. 2. A radio receiver comprising: drive means for driving said first control means when said first control means is in use, and for driving said second control means after a reception operation of a frequency stored in said memory is performed. 2. The memory stores frequencies of broadcast waves in the order in which they are received, and the first control means sets the frequencies stored in the memory as reception frequencies in the order of newest stored frequency. 1. The radio receiver according to 1.