JPH0132423Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is an in-vehicle device that has a preset tuning function that allows you to tune into the desired broadcasting station by simply pressing the tuning key, and to obtain the optimal reception condition depending on the strength of the received radio waves. It relates to radio receivers.

When using a conventional radio receiver with a preset tuning function, if you want to select a desired broadcasting station and achieve good reception, operate the tuning key to receive the desired station, and then check the received radio waves. Local/Distance (LO/DX) adjusts the level of received field strength input from the antenna if it is too strong.
)) It was necessary to operate the switch to the LO side, and if the received radio waves were weak, it was necessary to operate it to the DX side. For this reason, in car radio receivers where the receivable broadcast stations and received field strength change as the location changes, it is difficult to receive the desired station well and the operability is poor, and the LO/DX switch cannot be adjusted. The switching operation was cumbersome, and in some cases, the user could make a mistake in operating the LO/DX switch and listen to the broadcast in poor reception conditions.

This invention solves the above-mentioned problems and provides an extremely easy-to-operate preset that allows you to clearly see the status of the received radio waves at a glance, and to instantly receive the desired broadcasting station in good reception condition by operating the channel selection key. The purpose of the present invention is to provide a radio receiver having a channel selection function.

The present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an AM radio receiver that is an embodiment of the present invention, where 1 is an antenna, 2 is a high frequency amplifier, 3 is a mixer, 4 is an intermediate frequency amplifier, 5 is a detector, and 6 is a The low frequency amplifier and 7 are speakers, which have the same configuration as a known radio receiver. A voltage controlled oscillator 8 that inputs a local oscillation signal to the mixer 3 includes a prescaler 9, a programmable counter 10, and a phase comparator 1.
1, a reference oscillator 12, and a low-pass filter 13. Therefore, by changing the frequency division ratio of the programmable counter 10, the oscillation frequency of the voltage controlled oscillator 8 can be changed. 14 is an A/D that converts the detection signal detected by the detector 5 from an analog signal to a digital signal.
The digital signal output from the A/D converter 14 represents the electric field strength of the received radio waves.
15 is a tuning controller that determines whether the digital signal representing the electric field strength generated by the A/D converter 14 is greater than a predetermined value; if it is greater than the predetermined value, it sends a sweep stop signal to the channel controller 16; . The channel controller 16 includes, for example, a pulse generator and a counter inside, the counter counts the output pulses of the pulse generator, the count value output by the counter becomes frequency division number data, and the frequency division number data is transferred to a programmable counter. 10, programmable counter 1
It changes the frequency division ratio of 0, and when the count value of the counter exceeds a certain number, it outputs a pulse.
This output pulse stops the pulse generator and resets the count value of the counter, thereby limiting the variable range of the frequency division number data. 1
Reference numeral 7 denotes an attenuator that is controlled by the channel controller 16 and adjusts the level of the received electric field strength input from the antenna. A memory 18 stores frequency division number data corresponding to the frequency division ratio of the programmable counter 10 and data corresponding to the electric field strength converted by the A/D converter 14. 1
9 is a memory controller, and the memory controller 19 receives the frequency division data from the channel controller 16 and the A/D converter 1 detected by the detector 5.
Among the electric field strength data obtained through 4, the data representing the received electric field strength determined by the tuning controller 15 to be equal to or higher than a predetermined value is stored in the memory 18 and read out from the memory 18. 20 is memory controller 1
Display 21 displays the received electric field strength read out from memory 18 by 9 for each receivable channel.
This is a display driver that displays on the screen. A preset key 22 sends a sweep start signal to the channel controller 16. 23 is a tuning key for selecting a desired broadcasting station, and when the tuning key 23 is operated, a tuning signal is sent to the channel controller 1.
6 to the memory controller 19, and the memory controller 19 reads the frequency division number data corresponding to the channel selection key 23 stored in the memory 18, and sets the frequency division ratio of the programmable counter 10. Further, by operating the channel selection key 23, a signal indicating the strength of the electric field strength is sent to the channel controller 16 at the same time as the channel selection signal.Based on this signal, the channel controller 16 uses the attenuator 17 to adjust the received electric field input from the antenna 1. When the strength is strong, the attenuator 17 is placed in the LO reception state, and when it is weak, the attenuator 17 is put in the DX reception state to adjust the level of the received electric field strength.

Next, the operation of presetting the receiving station and displaying the electric field strength will be explained. Preset key 2
2 is turned on, a sweep start signal is sent to the channel controller 16, and the channel controller 16 sequentially changes the frequency division data given to the programmable counter 10 to adjust the local oscillation frequency supplied from the voltage controlled oscillator 11 to the mixer 3. is changed, and the sweep operation is started from the minimum frequency in the reception frequency range. At this time, attenuator 1
For example, the state 7 is assumed to be forced into the DX reception state. When a broadcast signal is received by changing the local oscillation frequency, the analog signal corresponding to the received electric field strength detected by the wave detector 5 is converted into digital data by the A/D converter 14, and then the tuning controller 15 determines whether the digital data converted by the A/D converter 14 is larger than a predetermined value, and if it is larger than the predetermined value, sends a sweep stop signal to the channel controller 16, and causes the channel controller 16 to sweep for a certain period of time. The reception frequency is maintained by stopping the operation, keeping the division ratio of the programmable counter 10 constant, and keeping the local oscillation frequency constant. When the sweep operation of the channel controller 16 is stopped, the memory controller 19 stores the frequency division number data of the channel controller 16 in the memory 17, and also stores the signal representing the digitized received electric field strength obtained by the A/D converter 14. The data is stored in the memory 18 via the tuning controller 15 and channel controller 16. Next, after a predetermined period of time has elapsed until the signal representing the frequency division number data and the electric field strength is stored in the memory 18, the channel controller 16 starts the sweep operation again, and all sweeps in the reception frequency domain are completed. Each time the tuning controller 15 issues a sweep stop signal, the memory controller 19 stores in the memory 18 frequency division number data of receivable channels and data representing the received electric field strength. Note that if a signal with an electric field strength smaller than a predetermined value of the tuning controller 15 is input, the sweeping operation continues without stopping. By limiting the variable range of the frequency division number data of the channel controller 16, the channel controller 16 ends the sweeping operation when all preset frequency regions have been swept. When the sweep operation is completed, the memory controller 19 reads out some stored data representing received field strengths and displays them on the display 21 via the display driver 20.

Next, the operation of selecting a channel by pressing the channel selection key and adjusting the level of the electric field strength of the signal input from the antenna to achieve the optimum reception condition will be explained.

When one of the channel selection keys 23 is pressed, a channel selection signal is sent to the memory controller 19 via the channel controller 16, and the memory controller 19 stores the division number data corresponding to the channel selection key 23 in the memory 18.
The channel controller 16 inputs the division number data to the programmable counter 10 and sets the division ratio, thereby setting the local oscillation frequency of the voltage controlled oscillator 8 and setting the desired reception channel. is received. Further, when one of the above-mentioned channel selection keys 23 is pressed, a signal instructing the strength of the electric field strength is sent to the channel controller 16 along with the channel selection signal, and the channel controller 16 controls the attenuator 17 based on the signal representing the electric field strength. When the electric field strength of the signal input from the antenna 1 is strong, the attenuator 17 is set to the LO reception state, and when it is weak, the attenuator 17 is set to the DX reception state to adjust the level of the input signal. In this way, by pressing one of the channel selection keys 23, a desired broadcast station can be received in the optimum reception condition.

FIG. 2 is a configuration diagram showing the configuration of the display 21 and the channel selection key 23 of the above embodiment. In FIG. 2, seven stations are displayed in the X direction and two levels of electric field strength are displayed in the Y direction. It has a matrix configuration, each component is a self-illuminated switch, the display 21 also serves as the channel selection key 23, and the channel selection key 23 ₂₁
~23 ₂₇ is the weak electric field strength, and the channel selection key 23 ₁₁
-23 ₁₇ are designed to display each strong electric field strength, and the hatched portion in the figure indicates that the display portion is lit. Therefore, for example, if you press the illuminated station selection key ₂₃₁₁ , one broadcast station stored in the memory 18 by operating the preset key 22 will be selected, and the attenuator 17 will enter the LO reception state, so that the optimum A good reception condition can be obtained. Furthermore, when the lit station selection key ₂₃₂₂ is pressed, the second broadcasting station preset in the memory 18 is selected, and the attenuator 17 enters the DX reception state to obtain the optimum reception state.

In the embodiment shown in FIG. 2, the number of stations on which electric field strength can be displayed is 7, but this number may be any number of stations, and there are two electric field strength display parts and channel selection keys 23 for strength and weakness. If you press the one of the tuning keys 23 that is not lit, for example, the tuning key 23 ₂₁ , the attenuator 17 will enter the DX reception state, so operate the tuning keys 23 ₁₁ to 23 ₁₇ that indicate strong. The attenuator 17 enters the LO reception state,
The attenuator 17 is configured to enter the DX reception state by operating the channel selection keys 23 ₂₁ to 23 ₂₇ indicating weak, but for example, when the lighting of the tuning key 23 ₁₁ , which is the channel selection key 23 of the same broadcasting station, is lit. Attenuator 1 is adjusted so that the reception condition is optimal for the strong electric field displayed regardless of whether you operate the station selection key 23 _{or 21} , which is not in the middle.
7 in the LO reception state, even if the channel selection key 23 on the side representing either strength or weakness is operated, the memory controller 19 is activated by the electric field strength stored in the memory 18 so as to correspond to the electric field strength when the display is lit. A signal indicating the strength of the electric field is sent to the channel controller 16 via the channel controller 16, and the channel controller 16 adjusts the level of the signal input from the antenna 1 using the attenuator 17 based on this signal. For example, when the signal is strong, the attenuator 17 can be placed in the LO reception state, and when the signal is weak, it can be placed in the DX reception state.

Furthermore, as shown in Figure 3, the display 21
It is also possible to separate the channel selection key 23 from the
22 is a preset key, 23 ₁ to 23 ₇ are channel selection keys, and 21 is a display, which is used to increase or increase the electric field strength.
Divided into three levels, medium and weak, each element of the display 21 is composed of a light emitting element, and the light emitting elements light up in the hatched areas to display the received electric field strength of each broadcast station preset in the memory 18. This is shown as an example.

As described above, the radio receiver according to the present invention includes a memory that stores data representing the reception frequency and reception field strength, an attenuator that adjusts the level of the reception field strength input from the antenna, and a receiver that stores the reception frequency and the reception field strength. The tuner section, the channel selection key,
A controller that controls a tuner section to receive a desired reception frequency stored in the memory in response to the operation of the channel selection key, and controls level adjustment by the attenuator based on the stored reception electric field strength. and a display device that displays the received field strength based on the data stored in the memory in correspondence with the channel selection key, so the status of the received radio waves can be clearly seen at a glance, and by simply operating the channel selection key. As the desired broadcasting station is selected,
If the received radio waves are too strong, the attenuator adjusts the received field strength to the optimal level, making it possible to immediately receive the desired broadcast station in good reception condition. can get. Furthermore, if the display device that displays the received electric field strength is constructed from a self-illuminated switch and is also used as a channel selection key, there is no need for space for the channel selection key, and more space is created on the panel. Not only can it be made smaller, but it can also reduce costs by reducing the number of manufacturing steps and parts.

Although an AM radio receiver was used in the embodiment, it is clear that the present invention can also be applied to an FM radio receiver.

Further, in the above embodiment, the received field strength is displayed and when the channel selection key is operated, the desired broadcasting station is selected and received, and the level of the received field strength is adjusted by the attenuator. By changing the attenuator, a means for detecting a stereo signal and a forced monaural key for forcibly switching the stereo reception mode to monaural reception mode were added. Instead of storing the received field strength in memory and displaying it on the display device, The presence or absence of a signal is stored in a memory and displayed on a display device, for example,
“Strong” channel selection keys 23 ₁₁ to 23 ₁₇ in Figure 2
is the stereo broadcast station display/selection key, and "Low"
The channel selection keys 23 ₂₁ to 23 ₂₇ are used as display and selection keys for monaural broadcast stations, and by operating the display and selection keys for stereo broadcast stations, the desired broadcast station is selected and received, and the system enters stereo reception mode. If a stereo broadcast is received in stereo mode and the monaural station display/selection key is operated, the desired broadcast station will be selected and received, and the mode will change to monaural reception mode. Configure the radio receiver to receive the radio signal. Therefore, by operating the channel selection key that displays stereo broadcasting or monaural broadcasting, the desired broadcasting station is selected and received, and switching between stereo and monaural can be performed instantly.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an AM radio receiver showing an embodiment of the present invention, Fig. 2 is a block diagram showing the structure of the display and channel selection key of Fig. 1, and Fig.
The figure is a configuration diagram showing another embodiment of the display and channel selection keys. 5... Wave detector, 10... Programmable counter, 14... A/D converter, 15... Tuning controller, 16... Channel controller, 17... Attenuator, 19... Memory controller, 21... Display, 22... Preset key, 23... Channel selection key.

Claims (1)

[Scope of utility model registration request] A memory that stores data representing the received frequency and received field strength, an attenuator that adjusts the level of the received field strength input from the antenna, a tuner section that receives the received frequency, a tuning key, and a tuning key that controls the tuning key. a controller that controls a tuner unit to receive a desired reception frequency stored in the memory in response to an operation, and controls level adjustment by the attenuator based on the stored reception electric field strength; A radio receiver comprising: a display device that displays received field strength based on stored data in correspondence with the channel selection key.