JP2001306085A - Playback sound generating apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reproduced sound generating apparatus and method capable of preventing an increase in the cost of the apparatus, an increase in the size of the apparatus, and a decrease in sound quality, and which can clearly hear even a low-frequency sound having a low frequency with a sine wave. I do. SOLUTION: A reproduced sound generating unit 27 and a ring tone melody generating circuit 33 capable of generating a reproduced sound that can be heard even at a place away from the ear, and a control unit for controlling the reproduced sound generating unit 27 and the ring tone melody generating circuit 33. When the reproduction sound generation unit 27 and the ringtone melody generation circuit 33 generate a low frequency sound of approximately several hundred hertz or less with a sine wave fundamental wave, the control unit 28 Controls the reproduction sound generation unit 27 and the ringtone melody generation circuit 33 so as to output a harmonic component of the frequency of the fundamental wave superimposed on the fundamental wave.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproduced sound generating apparatus and method for generating a reproduced sound such as a ring tone as in a portable telephone.

[0002]

2. Description of the Related Art As a conventional reproduction sound generating apparatus, there is, for example, a mobile phone. This mobile phone is provided in a portion of the mobile phone which touches a person's ear, and the other party's voice can be heard during a call. A small speaker (reproduced sound generation unit) for generating a reproduced sound such as a ringtone melody is provided separately from the call speaker which is provided. Portable telephones have been competing to be reduced in size and weight so that they can be easily carried and used.

[0003]

However, in such a conventional portable telephone, as the size and weight of the portable telephone have been reduced, the size of a small speaker for generating a reproduced sound such as a ring tone has also been reduced. However, there is a tendency that the lower limit of the frequency of sound that can be generated from small speakers tends to be high, and such high-range sounds can be clearly heard, but low-frequency low-range sounds can hardly be heard. ing.

[0004] In particular, the small speaker has, for example, a high sound quality but an output waveform of four octaves (277 to 277).
In the case of using a sine wave whose frequency changes between 4186 Hz), there is a problem that a sound having a frequency within a range of about 277 to 523 Hz (1 octave) on the low frequency side is hardly heard. . If an expensive sound source IC such as a PCM sound source or an FM sound source is used, it is possible to sufficiently hear even a sound in a low frequency range, but there is a problem that the cost of the entire apparatus is increased.

There is a method of increasing the physical space between a mobile phone and a speaker in order to obtain a low resonance frequency in order to clearly hear low-frequency sounds having low frequencies. It cannot be adopted because it goes against the reduction in size and weight of telephones.

In order to clearly hear low-frequency sounds having a low frequency, there is a method in which a distortion wave such as a square wave or a sawtooth wave is used as a sound waveform of a speaker. However, there is a problem in that the sound generated from the speaker is out of order and the sound quality is deteriorated.

[0007] In view of the above problems, the present invention can prevent an increase in the cost of the apparatus, an increase in the size of the apparatus, and a decrease in sound quality, and can clearly reproduce a low-frequency sound having a low frequency with a sine wave. It is an object to provide a generator and a method.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems, a reproduced sound generating apparatus according to the present invention includes a reproduced sound generating section capable of generating a reproduced sound that can be heard even at a place distant from an ear; A control unit for controlling a sound generating unit, wherein the reproduced sound generating unit generates a low frequency sound of approximately several hundred hertz or less with a sine wave fundamental wave, the control unit includes: Has a configuration in which the reproduced sound generation unit is controlled so as to output a harmonic component of the frequency of the fundamental wave superimposed on the fundamental wave.

According to the reproduced sound generating apparatus having such a configuration, the reproduced sound generating section for generating the reproduced sound that can be heard even at a place away from the ear has at least a fundamental wave of a sine wave and a low frequency of about several hundred hertz or less. When generating a sound, the control unit controls the reproduction sound generation unit so that the harmonic component of the frequency of the fundamental wave is superimposed on the fundamental wave and output, so even low-frequency sounds with low frequencies stay away from the ear Can be heard clearly in place. Also, there is no need to increase the physical space of the device or the speaker, and it is not necessary to use a distortion wave such as a rectangular wave or a sawtooth wave for the sound waveform of the speaker. A decrease in sound quality can be prevented.

[0010]

Embodiments of the present invention will be specifically described below with reference to the drawings. 1 to 6
FIG. 1 is a diagram referred to for describing a first embodiment of a reproduced sound generating apparatus and method according to the present invention.

A portable telephone 10 (reproducing sound generator) shown in FIG. 1 includes a telephone body 12 having a communication function, and an antenna 1 is provided on a casing 16 of the telephone body 12.
8 are provided. On the front part of the casing 16, the receiving speaker 20 and the LCD (L
A liquid crystal display unit 22 using a liquid crystal display, a large number of operation keys 24, a microphone 26 for voice input, and a small incoming notification speaker 27 for generating a sound such as a ringing melody that can be heard even at a place away from the ear. Is provided.

FIG. 2 is a block diagram schematically showing the circuit of the mobile phone 10. The antenna 18, the receiving speaker 20, the liquid crystal display 22, the operation keys 24, the microphone 26, and the incoming call notification speaker 27 have respective functions. So that the analog signal AS can be input to the controller 27, the transmission circuit 30, the reception circuit 32, the transmission / reception switching unit 34, and the speaker 27 for notifying an incoming call when there is an incoming call. Floor generation circuit) is provided.

The incoming call notification speaker 27 and the incoming melody generating circuit 33 constitute a reproduced sound generating section for generating a reproduced sound that can be heard even in a place away from the ears. An analog circuit capable of inputting the analog signal AS from the incoming melody generating circuit 33 as shown in FIG. 3 is connected to the incoming call notification speaker 27.

That is, according to the analog circuit of FIG. 3, the analog signal AS from the incoming melody generating circuit 33 is added to the fundamental component (SINωt) and the second harmonic component (SIN2ω).
t) and one or both of the fourth harmonic component (SIN4ωt) are selectively added, and can be input to the incoming call notification speaker 27.

A waveform when a second harmonic component is added to the fundamental wave component can be expressed by SINωt + ／ SIN2ωt = SINωt (1 + COSωt) (1), and has a waveform as shown in FIG.

The waveform when the fourth harmonic component is added to the fundamental wave component can be expressed by SINωt + 1 / 4SIN4ωt = SINωt {1 + COSωt (COS ² ωt−SIN ² ωt)} (2), as shown in FIG. Waveform.

The waveform when both the second harmonic component and the fourth harmonic component are added to the fundamental wave component is represented by SINωt + 1 / 2SIN2ωt + 1 / 4SIN4ωt = SINωt {1 + COSωt + COSωt (COS ² ωt−SIN ² ωt)} (3) The result is a waveform as shown in FIG.

When ω = 2πf, the above equations (1) to (3) are expressed as a function of the same frequency f as follows. (1): f + 2f (2): f + 4f (3): f + 2f + 4f

The fundamental wave and the harmonic components are calculated by the above equations (1) to (3).
Can be performed in part or all of the reproduction frequency range, and can be performed constantly or temporarily. It is also possible to adjust the amplitude and the composition ratio of the overtone components to be synthesized according to the situation and the frequency.

The operation of the mobile phone 10 will be described below. When a call is made to a called party using the mobile phone 10, the operator presses the operation key 24 while inputting the telephone number of the called party while looking at the liquid crystal display section 22.
, A radio wave is transmitted from the antenna 18 to make a call to the other party. When the line is connected to the other party, the conversation starts.

When the user speaks, when a voice is input to the microphone 26, a signal from the microphone 26 is transmitted to the destination by a radio wave transmitted from the antenna 18 via the transmission circuit 30 and the transmission / reception switching unit 34. Audio is sent.

When the other party talks, a radio wave transmitted from the other party is transmitted through an antenna 18 via a repeater (not shown).
, And the signal from the transmission / reception switching unit 34 is input to the receiving speaker 20 via the receiving circuit 32, so that the receiving speaker 20 can hear the voice of the telephone from the other party's telephone.

When there is an incoming call to the mobile phone 10 from the other party, the incoming call announcement speaker 27 to which the analog signal AS from the incoming call melody generating circuit 33 controlled by the controller 28 is input can be heard even in a place away from the ear. Generates such ringtone playing sound.

Conventionally, when the reproduced sound heard from the incoming call announcement speaker 27 is a sine wave in a low sound range of several hundred hertz or less, it is extremely difficult to hear because sufficient sound pressure cannot be obtained. This is because conventionally, only the fundamental wave (SINωt) shown in FIG. 3 is transmitted from the incoming call melody generating circuit 33 to the incoming call announcement speaker 27 during reception.

When the fundamental wave is in a high tone range of several hundred hertz or more, a sufficient sound pressure can be obtained, so that the reproduced sound from the incoming call announcement speaker 27 does not become difficult to hear.
As described above, when the fundamental wave is in a low-frequency range having a frequency of several hundred hertz or less, a sufficient sound pressure cannot be obtained.
As shown in the figure, in the low-tone range having a frequency of several hundred hertz or less, the audibility level decreases and it becomes very difficult to hear.

In order to solve such a conventional problem,
In the present embodiment, when the fundamental wave is in a low frequency range of several hundred hertz or less, as shown in FIG. 3, as the analog signal AS from the incoming melody generating circuit 33, the fundamental wave component (S
The controller 28 controls the ring tone melody generating circuit 33 so that the second harmonic component (SIN2ωt) and the fourth harmonic component (SIN4ωt) are simultaneously sent to the incoming call notification speaker 27 in addition to IN (ωt).

Incidentally, the waveform of only the fundamental wave is a sine wave as shown in FIG. 5, but when the second harmonic component and the fourth harmonic component are transmitted from the ring tone melody generating circuit 33 to the ring tone notification speaker 27 simultaneously with the fundamental wave component. Shows the waveform as shown in FIG.

For this reason, even if the sound has a low frequency of about several hundred hertz or less, the apparent bass reproduction can be emphasized.
As shown in FIG. 4 (a), the hearing level can be increased in the same manner as in the mid-high range of frequencies of several hundred hertz or more.
Even the sound in the low frequency range can be clearly heard from the incoming call announcement speaker 27.

The sound in the low frequency range can be clearly heard without increasing the size of the portable telephone 10 or the speaker 27 for notifying the incoming call and without using a distortion wave such as a rectangular or sawtooth wave in the sound waveform. Therefore, it is possible to prevent the mobile phone 10 from being enlarged and the sound quality from being deteriorated. In terms of musical scale, the overtone of "La" is "La", and the overtone is also "La", so that it is possible to prevent the pitch of the ring tone from being out of order.

FIG. 7 is a diagram referred to for describing a second embodiment of the present invention. In the first embodiment, the controller 28 controls the incoming melody generating circuit 33 by using an analog circuit as shown in FIG.
Although the type of the analog signal AS to the incoming notification speaker 27 is controlled to be variable, in the present embodiment,
Instead of using an analog circuit as shown in FIG.
As shown in (1), the controller 28 digitally calculates and changes the analog signal AS based on the program software, and outputs the analog signal AS converted to analog via the D / A converter 38 to the incoming call notification speaker 27. Are different in that In the second embodiment as well, the same effects as in the first embodiment can be obtained.

In the first embodiment,
Incoming call announcement speaker 2 from incoming melody generating circuit 33
Although the case where the second harmonic component and the fourth harmonic component are transmitted at the same time as the fundamental wave component is described in FIG. 7, the second harmonic component may be transmitted simultaneously with the fundamental wave component as shown in FIG. The fourth harmonic component may be sent simultaneously with the fundamental component as shown in FIG.

Further, in the first embodiment, the small incoming call notification speaker 27 is used, but a piezoelectric speaker is used instead of the small speaker.
Needless to say, it may be used for No. 7.

In the first embodiment, the mobile phone 10 has been described, but the present invention can be applied to toys and other devices.

Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments, and various other modifications may be made based on the technical concept of the present invention. Can be changed.

[0035]

As described above, according to the reproduced sound generating apparatus and method of the present invention, the reproduced sound generating section for generating the reproduced sound that can be heard even at a place distant from the ear is at least substantially a sine wave fundamental wave. When generating a low-frequency reproduced sound of several hundred hertz or less, the control unit controls the reproduced sound generating unit to output a harmonic component of the frequency of the fundamental wave superimposed on the fundamental wave, so that the frequency is low. Even low-pitched sound can be clearly heard at a place away from the ear. Also, there is no need to increase the physical space of the devices and speakers,
Since it is not necessary to use a distortion wave such as a rectangular wave or a sawtooth wave for the waveform of the reproduced sound of the speaker, it is possible to prevent an increase in the size of the reproduced sound generating device and a decrease in sound quality.

[Brief description of the drawings]

FIG. 1 is a mobile phone 1 according to a first embodiment of the present invention.
FIG.

FIG. 2 is a block diagram showing a circuit of the mobile phone 10 of FIG.

FIG. 3 is an analog circuit diagram that varies an analog signal AS input to a speaker 27 for incoming call notification.

FIG. 4 is a characteristic diagram showing the relationship between the audibility level of the sound reproduced from the incoming call announcement speaker 27 and the frequency thereof.
4A is a characteristic diagram of the mobile phone 10 shown in FIG. 1, and FIG. 4B is a characteristic diagram of the conventional mobile phone.

FIG. 5 is a waveform diagram when the analog signal AS is only a sine wave fundamental wave.

FIG. 6 is a waveform diagram in a case where the analog signal AS simultaneously outputs a second harmonic component and a fourth harmonic component together with the fundamental wave.

FIG. 7 is a main part block diagram referred to for describing a second embodiment of the present invention;

FIG. 8 is a waveform diagram in a case where the analog signal AS simultaneously outputs a second harmonic component together with a fundamental wave.

FIG. 9 is a waveform diagram when the analog signal AS simultaneously outputs a fourth harmonic component together with the fundamental wave.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Cellular telephone 12 Telephone main body 16 Casing 18 Antenna 20 Receiving speaker 22 Liquid crystal display part 24 Operation key 26 Microphone 27 Incoming announcement speaker 28 Controller 30 Transmission circuit 32 Receiving circuit 33 Ringing melody generating circuit 34 Transmission / reception switching part 38 D / A converter AS Analog signal

Claims (2)

[Claims] 1. A reproduction sound generation device comprising: a reproduction sound generation unit capable of generating a reproduction sound that can be heard even at a place away from an ear; and a control unit for controlling the reproduction sound generation unit. When the sound generator generates a low-frequency sound of approximately several hundred hertz or less with a sine wave fundamental wave, the control unit superimposes a harmonic component of the frequency of the fundamental wave on the fundamental wave and outputs the harmonic component. A reproduced sound generator, wherein the sound generator is controlled. 2. The method according to claim 1, wherein the reproduction is performed by using a reproduction sound generation device having a reproduction sound generation unit capable of generating a reproduction sound that can be heard even at a place away from the ear, and a control unit for controlling the reproduction sound generation unit. When the sound generator generates a low-frequency sound of approximately several hundred hertz or less with a sine wave fundamental wave, the control unit superimposes a harmonic component of the frequency of the fundamental wave on the fundamental wave and outputs the harmonic component. A reproduced sound generating method, wherein a sound generating unit is controlled.