JPS6117270A - Tone control device - Google Patents

Abstract

PURPOSE:To obtain a desired frequency characteristic by only selecting a sound source by constituting the titled device so that a tone controlling circuit has a frequency characteristic corresponding to the sound source by interlocking with a sound source changeover switch for selecting a signal from plural sound sources. CONSTITUTION:A radio receiver 1 for receiving an amplitude modulating broadcast, a radio receiver 2 for receiving a frequency modulating broadcast, a tape reproducing machine 3 for reproducing a magnetic cassette tape, and a disk reproducing machine 4 for reproducing a compact disk derive a sound souce signal to lines 1a-4a, as a sound source. A signal from these lines 1a-4a is switched selectively by a sound source changeover switch 5 which can be switched manually, applied to an amplifier circuit 6 and amplified. An output from the amplifier circuit 6 is adjusted to a desired frequency characteristic corresponding separately to the sound sources 1-4 which have been switched selectively, in a tone controlling circuit 7, and converted to a sound.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to tone control devices and, more particularly, to tone control devices that control the tone control of signals from multiple acoustic sources, such as radio receivers, tape players, and compact disc players. The present invention relates to a tone control device, which is a tone control circuit, for producing sound so as to have an optimal frequency characteristic corresponding to a source.

BACKGROUND OF THE INVENTION In the prior art, signals from multiple acoustic sources are selected and applied to a common tone control device, and the signals from the tone control device are audible. Tone control and frequency response of the device can be adjusted manually. Therefore, each time a sound source is selected, the tone control device must be readjusted to obtain the desired frequency characteristics for each sound source, which is cumbersome to operate. In particular, it is desired that such operations be simplified from the standpoint of safe driving when the device is installed in a vehicle or the like.

OBJECT It is an object of the present invention to provide a one-tone control device that is easy to operate and achieves frequency characteristics corresponding to each of a plurality of sound sources.

Structure of the Invention The present invention provides a tone control circuit having a plurality of selectively switchable frequency characteristics, an acoustic source changeover switch that selectively supplies signals from a plurality of acoustic sources to the tone control circuit, and an acoustic Interlocked with the source selector switch,
The tone control device is characterized in that it includes means for controlling the tone control circuit so that the tone control circuit has frequency characteristics corresponding to a selected sound source.

Embodiment FIG. 1 is an electrical circuit diagram of an audio system according to an embodiment of the present invention. Radio receiver 1 that receives amplitude modulation broadcasting
, Radio reception I! that receives frequency modulated broadcasting! 2. The tape player 3 for playing magnetic cassette tapes and the disk player 8!4 for playing compact discs output sound source signals to lines 1a, 2a, 3a, 4 as sound sources.
Derived into a. This line 1 a, 2 a, 3 a+
The signal from 4a is selectively switched by a manually switchable acoustic source changeover switch 5, and is applied to an amplifier circuit 6, where it is amplified. The output from the amplifier circuit 6 is adjusted by the tone control circuit 7 to a desired frequency characteristic that individually corresponds to the selectively switched sound sources 1 to 4, and is turned into sound by the speaker 8.

A status switch 9 is provided in conjunction with the sound source changeover switch 5. Radio receiver 1, 2, tape playback 8!
3 and disc playback 8!14 derive high level signals from lines 1b, 2b, 3b, 4b during their operation. When the acoustic signals from lines 1 a, 2 a, 3 a, and 4 a are being applied to the amplifying circuit 6 by the acoustic source changeover switch 5, the status switch 9 switches the acoustic signals being applied to the amplifying circuit 6. One of the four contacts corresponding to the sound sources 1 to 4 being generated is derived and applied to the input terminals 81 to S4 of the processing circuit 10. For example, an acoustic signal from the radio receiver 8!11 is applied to the amplifier circuit 6 via the acoustic source changeover switch 5 (in this case, from line 1b), and an level signal is applied via the contacts of the status switch 9. The remaining contacts of the status switch 9 are cut off, and the input terminals 82 to S4 are connected to the input terminal S1 of the processing circuit 10.
is low level. The processing circuit 10 is realized by a microcomputer or the like.

In order to manually change the frequency characteristics of the tone control circuit 7, a tone selection switch 11 realized by a push button switch or the like is connected. Processing circuit 1
0 has output terminals CI, C2, and the output terminals CI,
By applying the low and coded signals from C2 to the tone control circuit 7, the frequency characteristics of the tone control circuit 7 are changed in accordance with the coded signals. The display device 12 receives signals from the output terminals CI and C2 and displays the frequency characteristics of the tone control circuit 7.

The coded signals derived from the output terminals C1 and C2 of the processing circuit 10 and the frequency characteristics of the tone control circuit 7 are as shown in Table 1. For example, when a low level signal is derived from the output terminals CI and C2, the frequency characteristics of the tone control circuit 7 are flat over the entire range of reproduction frequencies. Further, for example, the output terminal c'i is at a low level, and the output terminal C
2 is at a high level, the frequency characteristics of the tone control circuit 7 are changed to characteristics that are enhanced in the bass range. The codes of the logical values from the output terminals C1 and C2 corresponding to the plurality of frequency characteristics of the tone control circuit 7 are defined as "0" to "3" as shown in Table 1.

The first table processing circuit 10 has a memory 13, and this memory 1
3 is a storage area Ml that individually corresponds to the sound sources 1 to 4;
~M4. The codes shown in Table 1 are stored in each of the store areas M1 to M4. This stored content can be changed by the tone selection switch 11.

FIG. 2 is a 70-chart for explaining the operation of the embodiment shown in FIG. Step n1 to step n
2, it is determined whether the tone selection switch 11 has been operated, and if it has not been operated, the process moves to step n6. At the step port 6, it is determined which of the input terminals 81 to S4 via the status switch 9 is at a high level, and thereby which of the acoustic signals from the acoustic sources 1 to 4 is selected via the acoustic source changeover switch 5. It is determined whether the signal is supplied to the amplifier circuit 6 or not. The processing circuit 10 stores the storage areas M1 to M4 of the memory 13 in step n6.
The codes “Oj to “3” stored in the storage areas M1 to M4 corresponding to the selected sound sources 1 to 4 are
is derived according to Table 2, and logic signals corresponding to this code are derived from output terminals C1 and C2. As a result, the tone control circuit 7 controls the selected sound sources 1 to 1.
The frequency characteristics correspond to 4.

When it is detected in step n2 of Table 2 that the tone selection switch 11 has been operated, the process moves to step n3, and the sound sources 1 to 4 selected by the sound source changeover switch 5 are
Store areas M1 to M4 corresponding to one of the four
Increment the code stored in by 1. In step n4, it is determined whether the code stored in the store areas M1 to M4 has become "4", and "
If the code is not ``4'', that is, if it is ``31 or less'', the process moves to step 6. In step n4, when the code becomes ``4'', the process moves to step n5, and the corresponding store areas M1 to M4 are stored. The stored contents are cleared to code "0" and the process moves to step n6.

Of course, the acoustic sources 1 to 4 may have a configuration that generates other acoustic signals.

Effects As described above, according to the present invention, the tone control circuit is made to have frequency characteristics corresponding to the sound sources in conjunction with the sound source changeover switch that selects signals from a plurality of sound sources. Simply select the sound source to obtain the desired frequency characteristics, making operation easy. ,

[Brief explanation of drawings]

Figure 1 is an electrical circuit diagram of one embodiment of the present invention, and Figure 2 is the electrical circuit diagram of one embodiment of the present invention.
3 is a flowchart for explaining the operation of the embodiment shown in the figure. 1.2... Radio receiver, 3... Tape player, 4
...Disc player, 5...Sound source selection switch, 6...Amplification circuit, 7...Tone control circuit, 8...Speaker, 9...Status switch, 1
0... Processing circuit, 11... Tone selection switch, 1
3...Memory

Claims (1)

[Claims] A tone control circuit having a plurality of selectively switchable frequency characteristics, a sound source changeover switch that selectively supplies signals from a plurality of sound sources to the tone control circuit, and a sound source changeover switch. A tone control device comprising means for controlling the tone control circuit in conjunction with each other so that the tone control circuit has frequency characteristics corresponding to a selected sound source.