JPH11284492A - Broadcasting wave receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a broadcasting wave receiver capable of saving time for automatic frequency sweeping and corresponding to two kinds of span frequencies. SOLUTION: First, automatic frequency sweep is performed by span at 100 kHz, an IF signal is detected 5 from an IF amplifier 3 when there is a broadcasting wave at the swept frequency, an IF frequency is counted with an IF counter 6, the counted IF frequency is read by a microcontroller 8, the existence of a broadcasting station at the set frequency is determined when that IF frequency is a nominal IF frequency, and that frequency is recorded. Next, automatic frequency sweep is performed with a span of 50 kHz and when the existence of a broadcasting station is detected, the above described recorded frequency is skipped so that a user can recognize only thenew broadcasting station.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadcast wave receiving apparatus having an automatic frequency sweep function and receiving a broadcast wave, for example, an FM broadcast wave.

[0002]

2. Description of the Related Art As a conventional technique, the frequency of FM broadcasting in Europe is determined at a span of 50 kHz, but most broadcast stations have a frequency of 100 kHz. So in the receiver, 100kHz and 50k
Although the switching of Hz is performed by a switch, if the setting is made at the time of the initial state when the power is turned on, the switching is not performed until the power is turned on and the initial time is reached.

[0003]

According to the above,
When the frequency of the FM broadcast is 50 kHz span, when the automatic frequency sweep function is used, the time for sweeping from the lower limit to the upper limit of the broadcast frequency is twice as long as that in the case of 100 kHz span, which is inconvenient. Conventionally, 50 kHz
Since only z-span or 100-kHz span can be selected, 10
If you switch to zero span, it will disappear. Therefore, the object of the present invention corresponds to two kinds of span frequencies,
An object of the present invention is to provide a broadcast wave receiving device capable of saving time for sweeping.

[0004]

A broadcast wave receiving apparatus according to the present invention automatically sweeps a reception frequency in a predetermined frequency span and stores a reception frequency at which a broadcast wave is assumed to exist. Means for setting a span frequency, and control means for automatically sweeping the reception frequency in the set frequency span and comparing the reception frequency at which the broadcast wave is assumed to exist with the already stored reception frequency. Is what you do.

The control means does not automatically store the received frequency or stop the automatic frequency sweep when both frequencies are the same as a result of the comparison, thereby saving the automatic frequency sweep time. it can. Further, when the comparison result shows that both frequencies are adjacent to each other, the control means re-confirms whether or not a broadcast wave exists at both frequencies. If a detection error is made, it can be corrected to the correct broadcast wave frequency.

Further, the broadcast wave receiving apparatus of the present invention automatically sweeps the reception frequency in a predetermined frequency span and stores the reception frequency at which the broadcast wave is assumed to exist. IF for detecting IF frequency value
Detecting means for automatically performing a frequency sweep of the reception frequency in a predetermined frequency span and determining the reception frequency at which the broadcast wave exists based on the sweep frequency at which the broadcast wave is present and the IF frequency value detected by the IF detection means. Control means for determining.

[0007] Further, the control means may determine that the IF frequency value detected at a specific sweep frequency differs from the nominal IF frequency by "span frequency / 2", and the IF frequency detected at an adjacent sweep frequency is equal to the nominal IF frequency. When the frequency differs from the IF frequency by “span frequency / 2” in the opposite direction, the intermediate frequency between the two sweep frequencies is determined as the reception frequency where the broadcast wave exists.
Even if automatic frequency sweep is performed at 0 kHz span, 50 kHz
Broadcast waves in a frequency span can be detected.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described. FIG. 1 shows the configuration of a basic synthesizer tuner. The FM broadcast wave received by the antenna ANT passes through the front end 1 and passes through the IF filter 2 to the IF
It is sent to the amplifier 3. Here, it is amplified and then subjected to FM detection 4. The detected signal is further amplified by the amplifier 9 and sent to the speaker 10. On the other hand, the IF signal is detected 5 from the IF amplifier 3, the IF signal is counted by the IF counter 6, and the IF frequency is sent to the microcontroller 8.

In the case of automatic frequency sweeping, when the receiving frequency is set in the PLL circuit 7 by the microcontroller 8, the PLL 7 enables the local station of the front end 1 to receive the designated broadcasting frequency. Next, if there is a broadcast at that frequency, the IF signal is detected 5 from the IF amplifier 3, the IF frequency is counted by the IF counter 6, and the counted IF frequency is read by the microcontroller 8, which is the original nominal frequency. If it is an IF frequency, it is determined that a broadcasting station exists at the set frequency.

If it is not the nominal IF frequency, the next receiving frequency above the span frequency is set, and the above operation is repeated. When a broadcast station is detected, auto stop or auto memory is performed at that frequency. In the operation of finding a broadcasting station by increasing or decreasing the frequency by one step at one span frequency as described above, the span frequency is set to 50 as in Europe.
In the case of 100 kHz and the case of 100 kHz,
There is a region where only the 00 kHz span may be used, and if automatic frequency sweeping is performed at a 50 kHz span frequency in that region, it takes time to perform automatic frequency sweeping of the FM frequency band.

Conventionally, the switch 11 of FIG. 1 is attached to the microcontroller 8 to provide a switch for switching between a 100 kHz span and a 50 kHz span. When this is set to any one, the tuning frequency goes up and down at the set span frequency, the received frequency stored at the time of switching is erased, and a new received frequency is stored. However, in an area such as Europe where there are few broadcast stations having a span of 50 kHz, only 100 kHz is required. Therefore, the automatic frequency sweep is performed at a span of 100 kHz, and the broadcast frequency is stored and used. However, portable radios and the like are used for local movement, so if there is a broadcasting station having a span of 50 kHz when moving, a new 50 kHz band is required.
It is necessary to change to z and perform an automatic frequency sweep, and the previous memory will be lost.

In the present invention, a new reception frequency is stored without erasing the previous storage even in the 50 kHz span. Even if two kinds of span frequencies are operated in the reverse order, a new reception frequency is stored without erasing the previous storage. However, in a device in which the mechanical span changeover switch 11 is abolished and can be easily switched and used with an operation key of a microcontroller, in the case of a 100 kHz span state, even if the stored frequency is 50 kHz span frequency, When the storage frequency is selected, the microcontroller 8 automatically sets 50k.
The storage frequency can be set as the reception frequency in the Hz span.

As a memory configuration of the microcontroller 8, the reference is set to a 50 kHz
In the case of kHz, it is treated as 50 kHz and 100 kHz.
At the time of the automatic frequency sweep in the case of the z-span, the tuning frequency may be raised or lowered by skipping one of the 50 kHz span frequencies.

FIG. 2 is a flowchart for explaining the operation of the storage content confirmation function when the two types of span frequencies are switched in the case of the "stop when a broadcast station is detected during automatic frequency sweep" function. When the automatic frequency sweep starts, the microcontroller 8 proceeds to step S
In step 1, the reception frequency is changed by one step (span frequency). Next, the IF count value of the IF counter 6 is read (step S2), and it is determined whether or not it is the nominal IF frequency. If it is, it is determined that there is a broadcasting station, and the process proceeds to step S4. If not, the process returns to step S1 (step S3). Next, in step S4, it is determined whether the same frequency as this frequency is stored in the memory of the microcontroller 8.

If the frequency is unregistered, it is determined that there is a new broadcast station, and the automatic frequency sweep is stopped (step S).
5). If the frequency is already registered, select the mode in the auto mode set in advance (whether to skip or stop if the frequency is the same in the automatic frequency sweep mode), and if it is stopped, stop the automatic frequency sweep at that frequency In the case of skip, the process returns to the routine S1 for shifting to the next reception frequency (step S6).

When the skip mode is selected, the user can know only a new broadcasting station to skip when the same frequency has already been registered. Is over and you can listen to the broadcast. Also, if the new broadcast frequency is the frequency next to the registered frequency at the time of automatic frequency sweep, the registered frequency is incorrect because the broadcasting station is operated on the principle that it is not adjacent. Since there is a possibility that there is a possibility, measure the IF count value at this frequency and the registered frequency again, and have a means to notify the user of the one with the nominal IF frequency count value as the correct broadcast frequency. Or, the correct one is automatically stored.

Next, of the two types of frequency spans, an automatic frequency sweep is first performed over a wide frequency span, and a broadcast frequency shifted by a narrow span frequency is recorded under predetermined conditions, thereby automatically performing a narrow frequency span. Explain that a broadcast station can be found without performing a frequency sweep.

FIG. 3 is a diagram showing a frequency axis in the case where a wide span of 100 kHz and a broadcasting station of 50 kHz exist between them. In the case of automatic frequency sweep in a 100 kHz span, as shown in FIG.
Hz → 90.1 MHz (→ 90.2 MHz →...) And the frequency is increased by the span frequency to be in the receiving state.

In this example, IF at 90.0 MHz
If the counter 6 detects a count value at a frequency 50 kHz lower than the nominal IF frequency, and then at 90.1 MHz the IF counter 6 detects a count value at a frequency 50 kHz higher than the nominal IF frequency, the 50 kHz frequency between them is detected.
It can be assumed that there is a broadcast station on the z span. By using this, as shown in FIG. 4, if the estimated frequency is displayed on the display device after the end of the sweep, the user can obtain 50k.
The broadcast station on the Hz span can be known and, if necessary, the user can store the frequency.

That is, when the automatic frequency sweep is started, the microcontroller 8 changes the reception frequency by one step to F (n) in step S10. Next, the IF count value of the IF counter 6 is read (step S11), and it is determined whether the IF count value is (-ci) or (+ ci) with respect to the nominal IF frequency (ci).
Is the span frequency / 2), and if -ci, that fact is temporarily stored (step S13), and if + ci, it is step S
Proceed to 14. In step S14, it is determined whether or not there is a temporary storage of -ci at the time of F (n-1). If not, the process returns to step S10, and if there is, the reception frequency F (n)-
Ci is temporarily recorded as a certain frequency of the broadcast wave. If the IF count value is neither (-ci) nor (+ ci) with respect to the nominal IF frequency in step S12, the process proceeds to step S16 to determine whether or not to end the sweep.
When the sweep ends, the temporary recording frequency F (n) -ci is displayed (step S17), and the flow ends. If the sweep is not completed, the process returns to the routine S10 for shifting to the next reception frequency.

Then, the estimated frequency is automatically selected by the microcontroller 8 and I at this reception frequency is selected.
By confirming that the F count value is the count value of the nominal IF frequency, it is also possible to automatically record the broadcast frequency as the broadcast frequency. Although the preferred embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various improvements and design changes can be made without departing from the gist of the present invention. is there.

For example, in the present invention, not only in Europe but also in Japan where only the 100 kHz span is used, the automatic frequency sweep is performed in 200 kHz steps and the IF count value is analyzed as described above. Thus, even if the automatic frequency sweep is performed in the 200 kHz span, the broadcast frequency in the 100 kHz span can be detected. As a selection mode of this method, the user can select two types of normal automatic frequency sweep and quick automatic frequency sweep.

[0023]

As described above, according to the present invention, it is necessary to perform automatic frequency sweeping over a wide frequency span without increasing the automatic frequency sweeping time for only a few broadcasting stations having a narrow frequency span. Only the broadcasting station of the frequency can be swept, and the automatic frequency sweeping time can be saved.

[Brief description of the drawings]

FIG. 1 is a general block diagram of a synthesizer tuner.

FIG. 2 is a flowchart illustrating an operation of the microcontroller of the present invention when performing automatic frequency sweeping in two types of spans.

FIG. 3 is a diagram showing a reception frequency in one step of frequency change.

FIG. 4 is a flowchart illustrating an operation in a case where a frequency sweep is automatically performed at a wide span frequency and a broadcast station having a narrow span frequency is also detected.

[Explanation of symbols]

 Reference Signs List 1 front end 2 IF filter 3 IF amplifier 4 FM detection 5 IF signal detection 6 IF counter 7 PLL 8 microcontroller 9 amplifier 10 speaker 11 switch

Claims (5)

[Claims] 1. A broadcast wave receiving apparatus for automatically sweeping a reception frequency in a predetermined frequency span and storing a reception frequency at which a broadcast wave is assumed to exist, means for setting a span frequency, A broadcast wave receiving apparatus comprising: a control unit configured to automatically sweep a reception frequency in a frequency span and compare a reception frequency in which a broadcast wave is assumed to exist with a previously stored reception frequency. 2. The control means according to claim 1, wherein, when the two frequencies are the same as a result of the comparison, the control means does not automatically store the received frequency or stop the automatic frequency sweep. Broadcast wave receiver. 3. The control means according to claim 2, wherein if both frequencies are adjacent to each other as a result of the comparison, the control means checks again whether or not a broadcast wave exists at both frequencies. The broadcast wave receiving device according to claim 1 or 2, wherein 4. An IF detector for detecting an IF frequency value for a received broadcast wave in a broadcast wave receiving apparatus for storing a received frequency at which a broadcast wave is present by automatically sweeping the received frequency over a predetermined frequency span. Means, and a receiving frequency at which a broadcast wave is present is determined based on a sweep frequency at which a broadcast wave is assumed to be present by automatically sweeping a receiving frequency in a predetermined frequency span and an IF frequency value detected by the IF detecting means. A broadcast wave receiving apparatus comprising: 5. The control means according to claim 1, wherein the IF frequency value detected at the specific sweep frequency is different from the nominal IF frequency by “span frequency / 2”, and the IF frequency detected at the adjacent sweep frequency is equal to the nominal IF frequency. 5. The broadcast according to claim 4, wherein when the IF frequency differs by "span frequency / 2" in the opposite direction, a frequency intermediate between the two sweep frequencies is determined as a reception frequency at which a broadcast wave exists. Wave receiver.