JPH08111649A - Receiver - Google Patents

Abstract

PURPOSE: To receive a high quality reception signal by a constitution which is excellent in handling convenience and simple by forming a second oscillation means and automatically switching the frequency of a clock signal. CONSTITUTION: Under the control of a control means 13, the oscillation frequency of a second oscillation means 2 switched by a frequency switch means 5 is counted by a counting means 3 by defining the oscillation frequency of a first oscillation means 1 as a reference. Of the high frequency components of the counted frequencies, the nth order harmonic component of the value which is the nearest to the reception frequency of a reception means 6 is specified. The high frequency component which is farthest from the reception frequency of this specified nth order harmonic component is specified by a comparison arithmetic means 4. The oscillation frequency of the second oscillation means 2 is switched to the frequency corresponding to this specified high frequency component by a switch means 5. By this operation, the oscillation frequency of the second oscillation means 2 oscillating a clock signal for a microcomputer 13 can be automatically switched to the frequency which does not interfere with a reception signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver having a radio receiving function and system-controlled by a microcomputer.

[0002]

2. Description of the Related Art In recent years, radio receivers, magnetic recording devices,
A microcomputer driven by a clock having a predetermined frequency is generally used for system control of an audio device having a plurality of functions such as a clock function.

In this way, it is supplied to a microcomputer for system control of a device having a plurality of functions such as a receiving means for FM, AM broadcasting, TV broadcasting, etc., a clock function, a magnetic recording / reproducing means, a compact disc reproducing device and the like. If the clock signal to be generated and its harmonic components are in the vicinity of the reception frequency, the reception of the AM broadcast or the like is disturbed.

Therefore, in order to prevent such reception interference, conventional receivers use metal plates or the like to surround these elements so as to shield jamming radio waves from leaking,
If the interference still cannot be prevented, for example, Japanese Patent Application Laid-Open No. 63-63
As described in JP-A-73728, there has been adopted a system in which a mechanical switch is provided, and when interference occurs during reception, the frequency of clock oscillation is changed by switching the switch to prevent interference.

[0005]

However, in the conventional receiving apparatus as described above, it is necessary to provide a shield plate and a switch for changing the clock frequency, and if there is interference during reception, the operation of switching the switch is required. It was necessary, the device was expensive and very inconvenient.

In view of the above conventional problems, it is an object of the present invention to provide a receiving device which is free from reception interference by the oscillating means for oscillating the clock in the microcomputer.

[0007]

In order to solve the above-mentioned problems, a receiving device of the present invention is a receiving device system-controlled by a microcomputer, which is a receiving device for receiving radio signals and the like, and a receiving device of a constant frequency. First to oscillate a signal
Oscillating means, second oscillating means for oscillating the clock signal of the microcomputer, frequency switching means for switching the oscillating frequency of the second oscillating means to a plurality of frequencies, and oscillating frequency of the first oscillating means. Counting means for respectively counting a plurality of oscillation frequencies of the second oscillating means switched by the frequency switching means with reference to
For each of the plurality of oscillation frequencies of the second oscillating means, the nth order harmonic component closest to the receiving frequency of the receiving means is calculated, and the receiving frequency among the nth order harmonic components of the plurality of oscillation frequencies is calculated. Comparing operation means for specifying the harmonic component having the largest difference with the frequency change means for switching the oscillation frequency of the second oscillating means to the frequency corresponding to the specified harmonic component. Is characterized by.

For example, the frequency switching means sets the oscillation frequencies of the second oscillating means to f1 (Low) and f2 (Center).
r) and f3 (High), the counting means counts the frequencies f1 to f3 with the oscillation frequency of the first oscillation means as a reference, and the comparison operation means is closest to the reception frequency. While calculating the n-th harmonic component of f1 to f3, the n-th harmonic component f1 ′,
Of the f2 'and f3', the harmonic component having the largest difference from the received frequency is identified, and the frequency switching means sets the frequency of any one of f1 to f3 corresponding to this harmonic component to the second oscillating means. The oscillation frequency will be switched.

Further, when the receiving device has a clock function, the oscillating means for outputting the reference clock to the clock function is shared with the first oscillating means for oscillating a signal of a constant frequency.

[0010]

According to the present invention, the counting means counts and counts the oscillation frequency of the second oscillation means switched by the frequency switching means with reference to the oscillation frequency of the first oscillation means. Of the harmonic components of each frequency, the nth harmonic component having the closest value to the reception frequency is specified, and the nth harmonic component farthest from the reception frequency among the specified nth harmonic components. The oscillation frequency of the second oscillation means is switched to the frequency having the component.

By such an operation, the oscillation frequency of the second oscillating means for oscillating the clock signal to the microcomputer is automatically switched to a frequency that does not interfere with the received signal, so that the user of the receiving device can switch the frequency. It is possible to perform high-quality reception with a simple configuration without the trouble of performing.

In particular, by accurately counting the oscillation frequency of the second oscillating means with reference to the oscillation frequency of the first oscillating means, the second frequency is set to the optimum frequency at which the nth harmonic does not interfere with the received signal. The oscillation means can be switched.

The frequency switching means sets the oscillation frequencies of the second oscillation means to f1 (Low), f2 (Center),
In the case of switching to three of f3 (High), the counting means counts the frequencies f1 to f3 with the oscillation frequency of the first oscillating means as a reference, and the comparison operation means is closest to the reception frequency f1. Through f3, the nth harmonic component f1 ′,
Of the f2 'and f3', the harmonic component having the largest difference from the received frequency is identified, and the frequency switching means sets the frequency of any one of f1 to f3 corresponding to this harmonic component to the second oscillating means. By switching the oscillation frequency, 3
It is possible to switch the second oscillating means to an optimum frequency of the two frequencies that does not cause reception interference and oscillate the clock signal to the microcomputer without reception interference.

Further, when the receiving device has a clock function, the oscillating means for outputting a reference clock to the clock function and the first oscillating means for oscillating a signal of a constant frequency should be shared. As a result, it is possible to perform high-quality reception without reception interference without increasing the number of parts of the receiving device or the manufacturing cost.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Below, the receiver of the embodiment of the present invention will be explained.
This will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the receiving apparatus according to the first embodiment. In FIG. 1, reference numeral 1 is a first oscillating means using a crystal oscillator that oscillates with high precision for a watch or the like, 2 is a second oscillating means for controlling a system, and 3 is a second oscillating means. The counting means 4 for counting the oscillation frequency of the oscillation means using the output of the first oscillation means 4 compares the oscillation frequency of the second oscillation means 2 with the reception frequency of the reception means based on the output of the counting means 3. Then, the comparison calculation means 5 for calculating the nth harmonic component which is the closest to the reception frequency with respect to the oscillation frequency of the second oscillation means 2 is an oscillation frequency switching means for switching the oscillation frequency of the second oscillation means, 6 is a receiving means, 7 is a magnetic tape recording / reproducing means, and 8 is the above 6-
7. A signal selection / amplification unit for selecting and amplifying the output signal of each unit, 9 a speaker for amplifying the signal output of the signal selection / amplification unit 8, 10 a plurality of the functional units, the oscillation frequency switching unit, and the comparison calculation. Means for mutually controlling the display means and the display means, 11 is a display means for displaying the plurality of functions 6 to 7, and 12 is an operation unit,
It is composed of SW and the like for selecting each of the means 6 to 7.

FIG. 2 is a detailed block diagram of the inside of the receiving means 6, in which 6a is an antenna, 6b is a PLL frequency controller, and 6 is a PLL frequency controller.
c is a front end circuit section, 6d is an IF detection circuit section,
PLL control data is input to 6e, and the detected low frequency signal is output from 6f.

FIG. 3 is an internal detailed circuit diagram of the clock oscillation circuit of the second oscillation means 2 and the oscillation frequency switching means 5, and I
C1 is an inverter circuit for oscillation, IC2, IC3 are inverter circuits for switching, CR1 is a ceramic oscillator, C1,
C2, C3 and C4 are capacitors, and the oscillation frequency switching signals are input from 5a and 5b.

That is, from 5a and 5b, respectively, Hih
By inputting signals of g and Low, the oscillation frequency (clock oscillation frequency) of the second oscillation means is f1 (5a.
HIGH, 5b ・ HIGH), f2 (5a ・ HIGH,
5b ・ LOW), f3 (5a ・ LOW, 5b ・ LOW)
Is switched to.

The oscillating frequency switching means may switch the oscillating frequency of the second oscillating means to a plurality of frequencies at minute intervals within a range that does not affect the driving of the microcomputer. As shown in FIG. , C2, C3, f1 (Low), f2 (Center),
The optimum frequency can be selected by switching the frequency of the second oscillating means to three of f3 (High).

FIG. 4 shows a case where the functions of the first oscillating means 1, the second oscillating means 2, the counting means 3, the comparing and calculating means 4 and the control means 10 of the receiving apparatus of the present invention are constituted by the microcomputer 13. 3 is a flowchart showing a main part of the processing operation of the microcomputer of FIG. 3, and the operation of the present invention will be described based on these.

First, it is assumed that the power supply of the device is turned on and the storage device and the like inside the microcomputer are initialized.

21 and 29 are connectors, which are incorporated in the main program. The signal 5a is HIGH, and the frequency of clock oscillation is determined by the ceramic oscillator CRI and the capacitors C1, C2 and C3.

First, in step 22, the PLL control data is sent to the PLL frequency control section 6b so that the receiving means 6 is in the operating state. In step 23, the reception frequency F is displayed on the display means 12.

In step 24, the oscillation frequency (clock oscillation frequency) f1 (Low), f2 (C) of the second oscillation means.
center), f3 (High) is oscillated at a constant frequency, and counting is performed using a counter of the microcomputer 13 based on high-precision oscillation (for example, crystal oscillation) of the first oscillating means 1.

First, the oscillation frequency of the second oscillation means is set to f1.
In order to switch to, the control means of the microcomputer 13 sends a HIGH signal to 5a and a HIGH signal to 5b of the oscillation frequency switching means (FIG. 3).

Oscillation frequency f1 of the second oscillating means at this time
Based on the oscillation frequency of the first oscillation means, the microcomputer 13
Count for about 1 second at the counter.

At the same time, the oscillation frequency f2 of the second oscillation means 2
Also counts. The oscillation frequency of the second oscillating means can be counted by the number of clocks at this time.

Next, f2 (5a.HIGH, 5b.LO
W) and f3 (5a.LOW, 5b.LOW) are similarly counted using the highly accurate oscillation of the first oscillating means 1.

In step 25, the data of the reception frequency F currently received is input. Here, the receiving means is 80.2
Assuming that MHz is being received, the oscillation frequency f2 (Cen
ter) is set to 4 MHz, and f1, f2, and f3 are each changed by 0.5%.

Next, at step 26, the reception frequency F (8
Harmonic components f1 ', f2', f3 'of the oscillating frequencies f1 to f3 of the second oscillating means closest to 0.2 MHz).
Is counted by the microcomputer 13.

Here, the twentieth harmonic component of f1 to f3 is closest to the reception frequency F (80.2 MHz), and f
1 '(79.6 MHz), f2' (80.0 MHz),
Assume f3 '(80.4 MHz).

In step 27, a signal is sent to the oscillation frequency switching means so that the difference between the reception frequency F and the twentieth harmonic component of the oscillation frequencies f1 to f3 of the second oscillation means 2 becomes maximum.

Here, the 20th harmonic component of f1 (7
Since the difference between 9.6 MHz) and the reception frequency F (80.2 MHz) is the largest, the signals 5a.HIGH and 5b.HIGH that cause the second oscillating means to oscillate f1 are sent to the oscillating frequency switching means.

As described above, according to the embodiment of the present invention, by automatically switching the oscillating frequency of the second oscillating means for oscillating the clock signal to the microcomputer to a frequency that does not interfere with the received signal, the receiving device It is not necessary for the user to switch the frequency, and high-quality reception can be performed with a simple configuration.

In particular, by accurately counting the oscillation frequency of the second oscillating means with reference to the oscillation frequency of the first oscillating means, the second frequency is set to the optimum frequency at which the nth harmonic does not interfere with the received signal. The oscillation means can be switched.

Further, when the receiving device has a timer function, the oscillating means for outputting a reference clock to the timer function and the first oscillating means for oscillating a signal of a constant frequency should be shared. As a result, it is possible to perform high-quality reception without reception interference without increasing the number of parts of the receiving device or the manufacturing cost.

[0038]

As described above, according to the present invention, the oscillating frequency of the second oscillating means for oscillating the clock signal to the microcomputer can be accurately switched to the optimum frequency in accordance with the receiving frequency. It becomes possible to realize a receiving device that performs extremely high quality reception with a simple configuration without a person having to provide a switch for changing the clock frequency.

[Brief description of drawings]

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

FIG. 2 is an internal detailed block diagram of a receiving means in the embodiment.

FIG. 3 is an internal detailed circuit diagram of a clock oscillation circuit and oscillation frequency switching means 5 of a second oscillation means in the embodiment.

FIG. 4 is a flowchart showing the processing operation of the microcomputer 13 for explaining the operation of the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st oscillation means 2 2nd oscillation means 3 Counting means 4 Comparison calculation means 5 Oscillation frequency switching means 6 Receiving means 6a Antenna 6b PLL frequency control section 6c Front end circuit section 6d IF detection circuit section 7 Magnetic tape recording / reproducing means 8 signal selection amplification section 9 speaker 10 control means 11 display means 12 operation section 13 microcomputer IC1, IC2, IC3 inverter circuit CR1 ceramic oscillator C1, C2, C3, C4 capacitor

Claims (3)

[Claims] 1. A receiving device system-controlled by a microcomputer, comprising: receiving means, first oscillating means for oscillating a signal of a constant frequency, and second oscillating means for oscillating a clock signal of the microcomputer. ,
Frequency switching means for switching the oscillation frequency of the second oscillation means to a plurality of frequencies, and a plurality of oscillation frequencies of the second oscillation means that are switched by the frequency switching means on the basis of the oscillation frequency of the first oscillation means. And n-th harmonic component that is closest to the reception frequency of the receiving means for the plurality of oscillation frequencies of the second oscillating means, and calculates the n-th order of the plurality of oscillation frequencies. Comparing and calculating means for specifying a harmonic component having the largest difference from the received frequency among the harmonic components, and the frequency switching means sets the frequency switching means to the frequency corresponding to the specified harmonic component. A receiving device characterized by switching the oscillation frequency of an oscillation means. 2. The frequency switching means sets the oscillation frequencies of the second oscillation means to f1 (Low) and f2 (Center).
r) and f3 (High), the counting means counts the frequencies f1 to f3 with the oscillation frequency of the first oscillation means as a reference, and the comparison calculation means receives the received signals. The nth harmonic component of f1 to f3 that is closest to the frequency is calculated, and
Among the next harmonic components f1 ', f2', f3 ', the harmonic component having the largest difference from the received frequency is specified, and the frequency switching means corresponds to these harmonic components f1 to f.
3. The receiving apparatus according to claim 1, wherein the oscillation frequency of the second oscillating means is switched to any one of the frequencies of 3. 3. The receiving device has a clock function, and an oscillating means for outputting a reference clock to the clock function and the first oscillating means for oscillating a signal of a constant frequency are shared. The receiving device according to claim 1 or 2.