JPH077924B2 - Electronic tuner - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electronic tuner, and particularly to an electronic tuner suitable for use as a car tuner.

“Prior Art” Most of the car tuners in recent years employ an electronic tuner. Some of these electronic tuners are capable of presetting desired stations for several stations, and the demand thereof is increasing due to the ease of channel selection.

In this type of preset tuner, a desired station is searched by automatic scanning by a frequency synthesizer, and when the station is tuned to the corresponding station, the scanning is stopped and a predetermined preset operation is performed. After the preset, the preset switch corresponding to the desired station is pressed to immediately tune to the station.

[Problems to be Solved by the Invention] The final characteristic of a tuner is determined by the sum of various characteristics such as high-cut control characteristic, stereo noise control characteristic, and frequency characteristic. Therefore, it is necessary to determine individual characteristics such as frequency characteristics depending on the final characteristics. And
In a conventional electronic tuner, a maker side determines final characteristics, and individual characteristics such as frequency characteristics are set so as to match the final characteristics.

However, since the tuner reception status varies depending on the user's local environment, the size of the broadcast output of the station, and the distance from the station, it is desirable that the final characteristics of the tuner also correspond to the reception status. . Therefore,
It would be ideal if the various characteristics of the tuner could be set on the user side and for each station, but in the conventional electronic tuner, the final characteristics of the tuner are fixed characteristics set by the manufacturer. We were unable to meet the request.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electronic tuner in which the user can set the characteristics for each station and the characteristic setting operation is easy.

[Means for Solving the Problem] In order to solve the above problems, the present invention is such that, when a preset switch is operated in the preset mode, the frequency of the station that is tuned to the storage area corresponding to the preset switch at that time In an electronic tuner that stores data and performs tuning according to the frequency data read from the corresponding storage area when the preset switch is operated in the read mode, a mode in which data indicating the characteristics of each circuit portion according to the reception mode is stored. The table, the mode switch that instructs the change of the receiving mode during reception, and the receiving mode selected by the preset switch pressed when the mode change is instructed by this mode switch, and the corresponding characteristics Data is read from the mode table and stored in the memory corresponding to the station being received. Receiving mode rewriting means to be stored in the rear, characteristic data reading means for reading characteristic data from a storage area corresponding to the preset switch in the reading mode, and circuit parts according to the receiving mode data read from the storage area or mode table And a characteristic control means for controlling the characteristic of.

After instructing to change the "action" mode, the preset switch functions as a mode selection switch, and any of a plurality of preset reception modes can be selected. The characteristic data is read from the mode table in accordance with this selection, and the characteristic of each part of the circuit is controlled according to the characteristic data. Further, the characteristic data read from the mode table is written in the storage area corresponding to the station being received, and thereafter, the characteristic data written in this storage area is received.

[Examples] Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, 1 is a front end, which is composed of a high frequency amplifier circuit, a local oscillation circuit and a mixing circuit. In this case, the local oscillator uses a PLL synthesizer, and when the frequency data is supplied, the oscillation frequency is controlled so as to tune to the frequency. Next, 2 is an intermediate frequency amplification / detection circuit including an intermediate frequency amplification circuit that amplifies the intermediate frequency signal output from the mixing circuit of the front end 1 and a detection circuit that detects the intermediate frequency output. The output signal is supplied to the multiplex circuit 3. Further, the intermediate frequency amplification / detection circuit 2 supplies the control circuit 7 with the signal S1 corresponding to the level of the received signal and the signal S2 indicating the level of the multipath noise. The multiplex circuit 3 is a circuit that demodulates a stereo signal, and the L channel signal and the R channel signal separated in this circuit are supplied to the equalizer circuit 4.

Here, the characteristics of the multiplex circuit 3 are shown in FIGS. FIG. 4A shows the high cut control characteristic, and two types of characteristics, characteristic A and characteristic B, can be selected. Here, the characteristic A has a low response to a low input level and is used in the normal mode (mode when the reception state is not so good). Further, the characteristic B has a high response even at a low input level and is used when performing HiFi reception. FIG. 2B shows a stereo noise control characteristic, and either A or B characteristic shown in the figure can be selected. Characteristic A has a low degree of separation with respect to a low input level, and the reproducibility of stereo is not good. However, when there is a lot of noise in the received signal, it is preferable to lower the degree of separation because the noise is less noticeable. This characteristic A is used in the normal mode. Further, the characteristic B has a high degree of separation even at a low input level, so that the stereo reproducibility is good,
Used when performing HiFi reception. The above characteristics must be selected for high cut control characteristics when the terminal HC
The signal S3 supplied to C selects either A or B characteristics.
Either the characteristic of A or B is selected by the signal S4 supplied to C.

Next, the equalizer circuit 4 shown in FIG. 1 is a circuit for performing de-emphasis and other frequency component adjustment,
Any of the three frequency characteristics (F characteristics) shown in FIG. 2C can be selected. Characteristic A shown in this figure
Is a characteristic that attenuates in the high range, and the reproducibility on the high range side is not good. However, when there is noise in the high frequency range, the noise is reduced, which is preferable. This characteristic A
Is used in normal mode. In addition, characteristic B
Has a flat characteristic from low to high frequencies, has good sound reproducibility, and is used when performing HiFi reception. The characteristic C is a characteristic that increases on the high frequency side, and is used particularly in a mode in which the high frequency is emphasized. The selection of the characteristic in the equalizer circuit 4 is performed by the signal S5 supplied to the terminal F. The signal output from the equalizer circuit 4 is amplified by the amplifier 5 and supplied to the speaker 6.

Next, 7 shown in FIG. 1 is a control circuit that outputs the above-described signals S3, S4, and S5. The memory 11 in this control circuit 7 is
It is composed of ROM and RAM. The ROM stores programs used by the CPU 10 and the mode table shown in FIG. This mode table stores data indicating the characteristics (A, B, C characteristics shown in FIGS. 2A to 2C) of each circuit portion corresponding to the reception mode. That is, in this embodiment, the reception mode is "1".
7 modes of "6" mode and normal mode are set, and for each mode, A characteristic, B characteristic or C characteristic is set for each of HCC, SNC and F characteristic. Further, the RAM of the memory 11 is set with a working area in which various data are temporarily stored and a preset data storage area in which preset data for stations (data contents are described later) are stored. In this case, the preset data storage area is
It is backed up by a battery and the stored contents are retained. In addition, the CPU 10 has a built-in timer so that it can perform timekeeping processing. Then 12,1
Reference numerals 3 and 14 are I / O interfaces.

Reference numeral 20 is a memory keyboard operated when storing preset data for the desired station in the memory 11, and has push switches SW1 to SW6. The on / off signals of these switches SW1 to SW6 are I / O interface 1
It is supplied to the CPU 10 via 2. Also,
The preset data storage area of the memory 11 is composed of a plurality of storage areas corresponding to the switches SW1 to SW6. SWM is a mode switch,
This is a switch that is operated when changing the reception mode.
The mode switch SWM is of a backlit type, and once pressed, it is lit for a certain period of time under the control of the CPU 10.

Next, the operation of this embodiment having the above configuration will be described.

Initial Preset Operation The initial preset operation for the desired station is as follows. First, an automatic scanning switch (not shown) is pressed to sequentially change the local oscillation frequency of the front end 1 to search for a desired station. When tuning to the desired station, fix the local oscillation frequency and press one of the switches SW1 to SW6.
Which switch SW1 to SW6 is pressed depends on which number the currently tuned station is preset to. To preset the number "1" for borrowing, press switch SW1. Then, when any of the switches SW1 to SW6 is pressed, the CPU 10 causes the frequency data of the station currently tuned and FIG. 2 (a), (b), (c).
The data for selecting the characteristic A shown in 1) is stored in the memory 11 as a set of preset data. in this case,
The preset data is stored in the area corresponding to the switch SW1 in the memory 11. The above processing is the same for the other switches SW2 to SW6.

Read Operation (Tuning Process) Next, the operation for receiving the station preset as described above will be described. First, the switch having the number corresponding to the desired station is pressed among the switches SW1 to SW6. When the switch SW1 is pressed, the memory corresponding to the switch SW1 11
The preset data is read from the internal storage area. Then, the frequency data in the preset data is supplied to the PLL synthesizer of the front end 1, and the values of the signals S3 to S5 are set as the values indicating the characteristic A according to the reception mode (normal mode in this case) indicated by the preset data. . As a result, the frequency synthesizer in the front end 1 is controlled to have the local oscillation frequency corresponding to the frequency of the desired station. Moreover, the multiplex circuit 3 and the equalizer circuit 4 are set to the A characteristic. In this way, by pushing any one of the switches SW1 to SW6, the preset station is tuned with the characteristic A.

Receiving Mode Change Processing First, the above processing is performed to tune to a desired station. It is assumed that the switch SW1 is pressed and is tuned to the preset station for this switch.

Next, the operator presses the mode switch SWM. As a result, the switch signal of the mode switch SWM is supplied to the CPU 10 via the I / O interface 12, and the CPU 10 starts executing the reception mode changing process. That is, the CPU 10 supplies a lighting signal to the lamp in the mode switch SWM via the I / O interface 12 to light the mode switch SWM. Thereby, the operator can know that the reception mode can be changed. Then, the operator pushes any one of the switches SW1 to SW6 in accordance with the number of the desired reception mode “1” to “6”. To select the reception mode "3", press the switch SW3. As a result, the switch signal of the switch SW3 is supplied to the CPU 10,
The CPU 10 reads from the mode storage table in the memory 11 each characteristic in the reception mode “3”, that is, the B characteristic for the high-cut control characteristic and the stereo noise control characteristic, and the C characteristic for the frequency characteristic, and uses these data as these data. Signals S3, S to correspond
Change the value of 4, S5. Therefore, during reception, the normal mode is changed to the reception mode “3”. Further, the CPU 10 writes the data showing the above characteristics in the storage area corresponding to the switch SW1 in the memory 11. in this case,
Data indicating the characteristic corresponding to the normal mode has already been written in the same storage area by the above processing, but this is rewritten to the characteristic data corresponding to the reception mode "3".

On the other hand, the CPU 10 starts the time counting process using the internal timer from the time when the mode switch SWM is pressed, and when a predetermined time has elapsed, turns off the lamp in the mode switch SWM and ends the mode changing process. As a result, when the switches SW1 to SW6 are pressed, the above-described processing is performed until the mode switch SWM is pressed again. In this case, if the process of is performed, the reception mode at the time of subsequent tuning is the changed reception mode.

However, even if the reception modes “1” to “6” are set, the CPU 10 may change to the normal mode based on the signal S1 or S2 supplied via the I / O interface 13. That is, when the reception state is poor and the input signal level is low, or when the multipath noise is large, the reception mode including the B characteristic and the C characteristic is stopped and changed to the normal mode based on only the A characteristic. Keep normal mode until it gets better.

Note that the present invention is suitable for use in a car tuner whose use environment changes with movement, but can of course be applied to an installation type audio tuner. this is,
This is because the usage environment differs depending on the user, and it is necessary to set the characteristics on the user side for each station.

[Effects of the Invention] As described above, according to the present invention, since the preset switch functions as the mode selection switch after the instruction to change the mode, any one of the reception modes set in advance can be selected. The circuit characteristics can be selected and the subsequent circuit characteristics are controlled by the characteristic data read from the mode table in accordance with the selection. Therefore, the user can set the characteristics for each station, and
This has the advantage that the characteristic setting operation can be made extremely easy.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing the structure of an embodiment of the present invention, and FIG.
FIG. 3 is a characteristic diagram showing characteristics of each part of the circuit in the embodiment, and FIG. 3 is a conceptual diagram showing stored contents of a mode table in the embodiment. 10 ... CPU (reception mode rewriting means: characteristic data reading means: characteristic control means), 11 ... memory (storage area, mode table), SW1 to SW6 ... preset switch, SWM
...... Mode switch.

Claims (1)

[Claims] 1. When a preset switch is operated in the preset mode, frequency data of a station tuned at that time is stored in a corresponding storage area, and when the preset switch is operated in the read mode. In an electronic tuner that tunes according to frequency data read from a corresponding storage area, a mode table that stores data indicating characteristics of each circuit portion according to a reception mode, and a mode switch that instructs a change of the reception mode during reception , A receiving mode is selected depending on which preset switch is pressed when the mode switch is instructed to change the mode, characteristic data corresponding to the selected mode is read from the mode table, and a memory corresponding to the receiving station is stored. Reception mode rewriting means to be stored in the area,
Characteristic data reading means for reading the characteristic data from the storage area corresponding to the preset switch in the reading mode, and characteristic control means for controlling the characteristic of each part of the circuit according to the reception mode data read from the storage area or the mode table. An electronic tuner characterized by being provided.