JPH02188011A - On-vehicle receiver - Google Patents

Abstract

PURPOSE:To eliminate the feeling of 'flossy' of a voice as much as possible by detecting the high-pitch range level of a voice frequency band being lowered intentionally by a crew and limiting or inhibiting the operation of an automatic tone control circuit in this case. CONSTITUTION:A tone circuit 6 varies the extent of a decrease in high-pitch range level by the automatic tone control circuit 5 at a request to attenuated the high-pitch range level which is made by the crew and the automatic tone control circuit 5 suppresses the extent of the decrease in the high-pitch range level more and more as the extent of the attenuation of the high-pitch range level requested by the crew is larger and larger. Consequently, the operation of the automatic tone control circuit 5 is limited substantially, and consequently even if a reception state changes, the high-pitch range level neither increases nor decreases to eliminate the feeling of 'flossy' of the voice due to the ON/ OFF operation of the automatic tone control circuit 5 while suppressing noises.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a receiving device such as a car radio installed in a vehicle, and in particular to an auto tone control system that changes the frequency characteristics of audio depending on the reception condition. Regarding what you have.

(Prior Art) Car radios for listening to music, news information, etc. in the cabin of a vehicle have been widely known, as shown in, for example, Japanese Utility Model Application No. 60-14529. F
FM Sica-Geo, which uses M radio waves, is mainly used for listening to music because its frequency band is wide.

By the way, since the FM radio waves have a high straightness, the reception condition deteriorates in areas such as valleys between buildings due to a decrease in electric field strength, and especially noise in the high frequency range increases, making it difficult to hear. For this reason, conventional measures have been taken to prevent the user from becoming aware of this even if the reception condition actually deteriorates.One of these measures is that when the reception condition deteriorates, audio An auto tone control system is known that suppresses noise by lowering the treble level.

(Problem to be Solved by the Invention) However, when the auto tone control system is installed, when the electric field strength changes from strong to weak in a relatively short period of time, the auto tone control circuit repeatedly activates and deactivates, causing the audio to become distorted. The treble level of the system repeatedly rises and falls, creating a condition known as ``fluffiness'' in which the sound becomes audibly unsteady, creating a problem in which it becomes difficult to hear.

The present invention has been made in view of the above points, and its purpose is to focus on the fact that under certain conditions no problem will occur even without an auto tone control system, and to develop an automatic tone control circuit under certain conditions. By restricting or prohibiting the operation, the automatic tone control circuit can be operated only when necessary, and the aim is to eliminate the "fluffy feeling" of the voice as much as possible.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention detects when the high frequency level of the audio frequency band is intentionally lowered by the passenger, and in that case, automatically controls the tone. Limit or prohibit circuit operation.

Specifically, as shown in FIG. 1, the configuration of the invention according to claim (1) automatically lowers the treble level of the frequency characteristics of the audio when the reception condition decreases as described above. The on-vehicle receiving device is equipped with an auto tone control circuit 5 that changes sound quality in accordance with an operation by a vehicle occupant.

A treble range level drop detection means 13 is provided for detecting that the treble range level has been lowered by a predetermined level or more by the sound quality changing means 9, and upon receiving the output signal of the detection means 13, the auto tone control circuit 5 is activated. A restricting means 14 is provided to restrict the.

Further, in the invention described in claim (2), the limiting means 14
Instead, the present invention is characterized in that a prohibition means 14' is provided for inhibiting the operation of the auto tone control circuit 5 in response to the output signal of the treble range level drop detection means 13.

(Function) With the above configuration, in the invention as claimed in claim (1), when the sound quality changing means 9 is operated by the passenger to attenuate the treble range level of the voice, this is detected by the treble range level reduction detection means 13. In this state, the limiting means 14 limits the operation of the auto tone control circuit 5.

In addition, in the invention described in claim '2J, when the treble range level is attenuated, the inhibiting means 14'
The operation of the auto tone control circuit 5 itself is prohibited.

By restricting or prohibiting the operation of the auto tone control circuit 5, the treble level does not change even if the reception condition changes, and the "fluffy feeling" of the voice can be eliminated.

In this case, since the frequency characteristics of the voice have been corrected by the occupant to consciously lower the treble level, the operation of the auto tone control circuit 5 is limited or prohibited by the limiting means 14 or inhibiting means 14'. However, no problem arises in terms of hearing sensation, and therefore, the "fluffy feeling" of the voice can be eliminated as much as possible.

Further, in particular, in the invention set forth in claim 2, since the operation of the auto tone control circuit 5 is prohibited, the control system can be simplified compared to the case where the operation is restricted.

(Example) Hereinafter, an example of the present invention will be described based on the drawings from FIG. 2 onwards.

FIG. 2 shows the overall configuration of an on-vehicle receiver according to an embodiment of the present invention, where 1 is a receiving antenna consisting of a rod antenna or the like attached to the vehicle, and this antenna 1 is connected to a high frequency amplifier 2. .

The high frequency amplifier 2 amplifies the high frequency signal of a target broadcasting station selected by tuning from among the radio waves received by the antenna 1. The high frequency signal outputted from the high frequency amplifier 2 is converted into an intermediate frequency signal of a predetermined frequency via a frequency converter (not shown), and then transferred to the intermediate frequency amplifier 3.
is input and amplified. Furthermore, this amplified intermediate frequency signal is input to a detection circuit (not shown) to be converted into a voice signal (audio signal), and then input to the multiplex circuit 4. This multiplex circuit 4 separates a stereo broadcast audio signal into left and right channels.

The audio signal output from the multiplex circuit 4 is input to an auto tone control circuit 5 that automatically sets the frequency characteristics of the audio wave band, and then input to a tone control circuit 6. As described later, the auto tone control circuit 5 has four types of maps 1 to 4 regarding preset frequency characteristics, and selects one of them to set the frequency characteristics. A frequency signal is output to the tone circuit 6.

On the other hand, the tone circuit 6 is connected to a bass level operating section 7 and a treble level operating section 8, each consisting of a variable resistor whose resistance value is changed by operating a knob or a slide lever (none of which are shown). In the tone circuit 6,
The bass and treble levels of the frequency characteristics of the audio wave region are respectively increased or decreased around a predetermined frequency in accordance with the amount of operation of the bass and treble level operation units 7.8. In this embodiment, the bass level operating section 7 and the treble level operating section 8 constitute a sound quality changing means 9 that changes the frequency characteristics of the sound according to the operation by the vehicle occupant.

Further, the output of the tone circuit 6 is input to an audio amplifier 10 having a preamplifier for input switching and the like and a main amplifier for driving a speaker, and an output line of this audio amplifier 10 is connected to a speaker 11.

Furthermore, 12 is a control circuit for selecting and switching the map to be used in the auto tone control circuit 5, and this control circuit 12 includes the treble level operation section 8.
In other words, the signal corresponding to the high frequency level of the frequency characteristic set by the tone circuit 6 and the antenna 1
A signal of electric field strength F of a radio wave is inputted to the input terminal.

The procedure for controlling the autotone control circuit 5 in the control circuit 12 will be explained with reference to FIG.

First, in step S1, the electric field strength F of the radio wave received by the antenna 1 is input, and in the next step S2, it is determined whether the electric field strength F is lower than a predetermined level.

When this determination is NO (F≧), the process proceeds to step S3, and a signal for selecting map 1 from among the four types of maps 1 to 4 set in advance and instructing it is output to the auto tone control circuit 5. The above Map 1 is shown in Figure 4 (a
), the frequency characteristics are set to be flat, with almost constant frequency levels from the bass to treble ranges. On the other hand, if the determination is YES (F<k), the process proceeds to step S4, where Map 2 is selected from Maps 1 to 4 and a signal instructing it is output to the auto tone control circuit 5. As shown in FIG. 4(b), map 2 is different from map 1 in that it has a frequency characteristic in which the frequency level from the bass to middle range is almost constant, and the level of the treble range is reduced.

After step S3 or S4, it is determined in step S5 whether a predetermined time has elapsed since the selection of the map by stopping the operation of the timer. This is to prevent hunting, where maps 1 and 2 are frequently switched in response to changes in the electric field strength F. If this determination becomes YES, the operating position P (the treble range level of the frequency characteristic set by the tone circuit 6) of the treble level operating section 8 by the occupant is detected in step S6, and the operating position P is detected in step S7. It is determined whether or not the first set position is on the damping side of the goblin. If this determination is No, the process ends, but if it is YES, the process proceeds to step S8, where map 2 is selected by the auto tone control circuit 5. In other words, it is determined whether the electric field strength F is low and the treble range level of the voice is lowered. This judgment is NO
If the determination is YES, the operation position P of the treble level operation section 8 is changed from the first setting position to a second setting position which is a further attenuation side position than 1 in step S9. Determine whether it is on the attenuation side of 2. When this determination is No, that is, the operating position P of the treble level operating section 8 is the first and second setting position J.
, 2, and a moderate attenuation of the treble level is required, the process proceeds to step Sll, selects map 3 from maps 1 to 4, and sends a signal instructing it to the auto tone control circuit. Output to 5. As shown in FIG. 14(c), the map 3 is set to have a frequency characteristic in which the frequency level from the bass range to the middle range is almost constant, and the level of the treble range is lowered to a higher level than the map 2.

On the other hand, when the determination is YES, that is, the treble level operation section 8
When the operation position P is at the second setting position on the attenuation side of 2 and a large attenuation of the treble level is required, the process proceeds to step Sl+, selects map 4, and sends a command signal to the auto tone. Output to control circuit 5.

This map 4, as shown in FIG. 4(d), is set to have a flat frequency characteristic in which the frequency level from the bass range to the treble range is substantially constant, similar to the map 1 described above. After these steps 310 r S If, the control ends.

Therefore, in this embodiment, step 8 of the above control procedure
7 to S9 constitute a treble range level reduction detection means 13 that detects that the treble range level has been lowered by a predetermined level or more by the sound quality changing means 9.

Also, step SI1. By SI+, the detection means 1
Limiting means 14 is configured to limit the operation of the auto tone control circuit 5 in response to the output signal No. 3.

Therefore, in the above embodiment, the control circuit 12
One of maps 1 to 4 is selected based on the electric field strength F of the radio wave input to the antenna 1 and the operating position P of the treble level operating section 8, and the frequency characteristics in the auto tone control circuit 5 are set according to the selected map. be done.

That is, when the electric field strength F is above a predetermined level,
Map 1 is selected. As a result, the frequency characteristics of the audio signal output from the auto tone control circuit 5 have a flat level from the bass range to the treble range.

On the other hand, when the electric field strength F is smaller than the predetermined level, map 2 is selected, and the treble level of the frequency characteristic of the audio signal output from the auto tone control circuit 5 is lowered. With this frequency characteristic, it is possible to suppress the noise that increases as the electric field strength F decreases, and it is possible to obtain a characteristic that is audibly preferable.

Furthermore, even if the frequency characteristics are set by map 1.2 according to the electric field strength F as described above, if the operation position P of the treble level operation section 8 is operated to the attenuation side, map 3 or map 4 will be changed. selected. In other words, the operating position P is the first
If the setting position P is on the increasing side with respect to 1 and the occupant does not substantially request attenuation of the high frequency level of the audio frequency, maps 1 and 2 are used as they are, but the operation position P is set to the first position. When the setting position is on the attenuation side of 1, the occupant requests attenuation of the high frequency range level of the audio frequency, and the electric field strength F is low, MAP 3 or MAP 4 is selected. First, the operating position P of the treble level operating section 8 is the first
and the second setting position kl+kz, and when moderate attenuation of the treble range level is required, map 3 having a frequency characteristic in which the treble range level is set to a higher level than map 2 is selected. In addition, when the operation position P of the treble level operation section 8 is on the attenuation side of 2 in the second setting value, and a large attenuation of the treble level is required, the range from the bass to the treble is similar to map 1. Map 4 has a frequency characteristic set to a flat characteristic up to
is selected. In this way, the degree of reduction in the treble range level in the auto tone control circuit 5 is changed according to the degree of attenuation of the treble range level requested by the occupant in the tone circuit 6, and the attenuation of the treble range level requested by the occupant is changed. The greater the degree, the more the auto tone control circuit 5 suppresses the degree of decrease in the high-frequency range level.

As a result, the operation of the auto tone control circuit 5 is substantially restricted, and due to the restriction of the operation of the auto tone control circuit 5, the treble level does not increase or decrease even if the reception condition changes. ON1 of auto tone control circuit 5 while suppressing noise
It is possible to eliminate the "fluffy feeling" of the sound associated with 0 F F and obtain aurally preferable characteristics.

In this case, since the frequency characteristics of the voice are corrected by the tone circuit 6 so as to intentionally attenuate the treble level, even if the operation of the auto tone control circuit 5 is restricted, no problem arises in terms of audibility.

In the above embodiment, the reception state is detected based on the electric field strength, but it is now detected based on so-called multipath distortion caused by the interference between the direct wave of the received radio wave and the reflected wave from structures such as buildings. You can.

Further, in the above embodiment, the operation surface W of the treble level operation section 8
By selecting and switching between maps 3 and 4 according to lp,
Although the operation of the auto tone control circuit 5 is restricted, it is also possible to prohibit the operation of the auto tone control circuit 5 itself. In that case, when the occupant requests a reduction in the level of the high frequency range, the auto tone control circuit 5 does not operate at all, so it is possible to eliminate the "fluffy feeling" as in the above embodiment, and the auto tone control circuit 5 5
There is an advantage that the configuration of the control circuit 12 can be simplified by prohibiting the operation of the .

Furthermore, in the above embodiment, the bass and treble level operation section 7
．． The frequency characteristics of the tone circuit 6 are changed according to the operation of the switch 8, but multiple frequency characteristics are set in advance and selected automatically by the operation of the switch. When a characteristic that lowers the treble level is selected from among the above, the operation of the auto tone control circuit 5 is restricted! It may be configured to stop at S, and the same effect as in the above embodiment can be obtained.

(Effects of the Invention) As described above, according to the in-vehicle receiving device of the present invention, it is possible to detect that the high-frequency range level of the voice is intentionally attenuated by the passenger, and in that case, the automatic tone control to lower the high-frequency range level is performed. Since the circuit is not required, its operation is restricted or prohibited, so the auto tone control circuit can be activated only when necessary, thereby making it possible to create a "fluffy" sound in the in-vehicle receiver. It is possible to resolve this issue in a proactive manner.

Particularly, in the invention described in claim ('2J), since the operation of the auto tone control circuit is prohibited, there is an advantage that the control system thereof can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of the present invention. Figure 2 and the following drawings show embodiments of the present invention. Figure 2 is a block diagram showing the configuration of an electric circuit, Figure 3 is a flowchart showing the signal processing procedure in the control circuit, and Figure 4 is a map diagram. FIG. 3 is a characteristic diagram showing frequency characteristics. 14' Auto tone control circuit Tone circuit Treble level operation section Sound quality changing means Control circuit Treble range level drop detection means Limiting means Prohibiting means Agent

Claims (2)

[Claims] (1) In a vehicle-mounted receiver equipped with an auto tone control circuit that automatically changes the frequency characteristics of the voice so that the high-frequency range level decreases when the reception condition deteriorates, the voice a sound quality changing means for changing frequency characteristics; a treble range level reduction detecting means for detecting that the treble range level has been lowered by a predetermined amount or more by the sound quality changing means; and the auto tone control circuit in response to an output signal of the detecting means. 1. A vehicle-mounted receiving device, comprising: a restriction means for restricting the operation of the vehicle. (2) In an in-vehicle receiver equipped with an auto tone control circuit that automatically changes the frequency characteristics of the audio so that the high frequency level decreases when the reception condition deteriorates, the audio a sound quality changing means for changing frequency characteristics; a treble range level reduction detecting means for detecting that the treble range level has been lowered by a predetermined amount or more by the sound quality changing means; and the auto tone control circuit in response to an output signal of the detecting means. An in-vehicle receiving device characterized in that it is provided with a prohibition means for prohibiting the operation of the vehicle.