CN201717918U - Mobile terminal - Google Patents
Mobile terminal Download PDFInfo
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- CN201717918U CN201717918U CN2010202498659U CN201020249865U CN201717918U CN 201717918 U CN201717918 U CN 201717918U CN 2010202498659 U CN2010202498659 U CN 2010202498659U CN 201020249865 U CN201020249865 U CN 201020249865U CN 201717918 U CN201717918 U CN 201717918U
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- frequency amplifier
- audio
- audio frequency
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Abstract
The utility model discloses a mobile terminal, which comprises a baseband, an audio-frequency amplifier and a piezoceramic loudspeaker, wherein the audio-frequency amplifier is used for amplifying an analog voice frequency signal from the baseband and outputting the analog voice frequency signal; the piezoceramic loudspeaker is used for receiving the voice frequency signal outputted by the audio-frequency amplifier and converting the voice frequency signal into a sound signal to be outputted; the audio output terminal of the baseband is connected with the input terminal of the audio-frequency amplifier; and the output terminal of the audio-frequency amplifier is connected with the input terminal of the piezoceramic loudspeaker. The thickness of the piezoceramic loudspeaker is only 1.00 mm, so that the whole thickness (the sum of the thickness of a voice cavity space above a shield cover, the thickness of the shield cover and the thickness of the loudspeaker) of the mobile terminal is less than 2.0 mm. Therefore, components with other functions can be additionally arranged in the saved space, and the layout wiring is smoother, which guarantees the aesthetic appearance of the mobile terminal and is beneficial for improving the performance of the mobile terminal.
Description
Technical field
The utility model relates to a kind of portable terminal, particularly relates to a kind of ultrathin mobile terminal that uses piezoelectric ceramic loudspeaker.
Background technology
At present, the use of mobile phone becomes basically universal.Yet when mobile phone was popularized, the user was also more and more higher to the requirement of handset structure.This requirement is embodied in the requirement to the thickness of mobile phone and area.Generally speaking, the device that influences these two aspects mainly contains the thickness and the length of battery, the thickness of loud speaker, and the thickness of USB interface etc.We can say that the thickness that has reduced these high devices just can reduce the thickness of mobile phone.In general, thin battery and USB interface are used in mobile phone fully, but the influence that loud speaker thickness brings for the mobile phone overall structure never well solves.And traditional loud speaker, not only influenced the thickness of complete machine, simultaneously because its huge volume has also influenced putting of a lot of other components and parts.Also force mobile phone to expand virtually to wideer longer direction.That is to say that the thickness of ventional loudspeakers has become the threshold that is difficult to go beyond of producing frivolous mobile phone.
The utility model content
The technical problems to be solved in the utility model is in order to overcome prior art the defective that size of mobile terminals such as mobile phone is difficult to reduce provides a kind of ultra-thin portable terminal that uses piezoelectric ceramic loudspeaker because the thickness limits of loud speaker makes.
The utility model solves above-mentioned technical problem by following technical proposals:
A kind of portable terminal, it comprises base band, its characteristics are that this portable terminal also comprises:
Audio frequency amplifier is used to amplify from the simulated audio signal of base band and with its output;
Piezoelectric ceramic loudspeaker is used to receive the audio signal of audio frequency amplifier output and is translated into voice signal output;
Wherein, the audio output of this base band links to each other with the input of this audio frequency amplifier, and the output of this audio frequency amplifier links to each other with the input of this piezoelectric ceramic loudspeaker.
Preferably; the audio output of this base band is connected to the input of this audio frequency amplifier by a plurality of input resistances and a plurality of input capacitance; the output of this audio frequency amplifier is connected to the input of this piezoelectric ceramic loudspeaker by a plurality of protective resistances, is connected with a plurality of feedback resistances between the input of this audio frequency amplifier and the output.
Preferably, the charge pump output voltage end of this audio frequency amplifier is by a reference capacitance ground connection.
Preferably, low level the RESET input of this audio frequency amplifier links to each other with the GPIO interface of this base band.
Preferably, the charge pump pumping capacitance cathode of this audio frequency amplifier links to each other by a boost capacitor with charge pump pumping electric capacity negative pole.
Positive progressive effect of the present utility model is: piezoelectric ceramic loudspeaker thickness has only 1.00mm, situation after being put into above the radome is opposite with the situation of using ventional loudspeakers, the space that the sound chamber requires adds the upper speaker body above radome, integral thickness is less than 2.0mm.On the whole, radome adds that piezoelectric ceramic loudspeaker adds the about 4mm of integral thickness in sound chamber, is far smaller than the height (height of 3.5mm earphone is 4.85mm) of 3.5 earphones of standard.Space under saving like this not only can increase the components and parts with other functions, and can make the layout wiring more smooth and easy, has not only guaranteed the aesthetic feeling of portable terminal outward appearance, also helps it to improve performance.
Description of drawings
Fig. 1 a-1c is a piezoelectric ceramic loudspeaker sounding operation principle schematic diagram.
Fig. 2 is the sound chamber schematic diagram of piezoelectric ceramic loudspeaker of the present utility model in portable terminal.
Fig. 3 is the schematic diagram of the front sender of portable terminal of the present utility model.
Fig. 4 is the schematic diagram of the survey face sender of portable terminal of the present utility model.
Fig. 5 is the circuit diagram of preferred embodiment of the present utility model.
Embodiment
Provide the utility model preferred embodiment below in conjunction with accompanying drawing, to describe the technical solution of the utility model in detail.
Piezoelectric ceramic loudspeaker structurally is attached on the sheet metal by piezoelectric ceramic piece from level to level and forms, and they combine and are known as vibrating membrane.When piezoelectric ceramic piece stretched, vibrating membrane will be bent upwards as shown in Figure 1a like that, and when piezoelectric ceramic piece shrank, vibrating membrane will be bent downwardly shown in Fig. 1 b like that.So when the voltage that adds an alternate to vibrating membrane, it will be ceaselessly crooked up and down along with the variation of voltage so, shown in Fig. 1 c.Piezoelectric ceramic loudspeaker is equivalent to a capacitive load, and is flexible up and down under the alternating action of bipolar current, promotes the gas flow in the sound chamber, thereby sends the sound.
Because piezoelectric ceramic loudspeaker itself is thin (less than 1mm) relatively, it relatively flexibly, has strict demand unlike traditional moving-coil loudspeaker to loudness of a sound in the design of sound chamber, as long as isolated the chamber, front and back with foam, audio mixing is just passable before and after preventing.Low requirement when designing just because of the ultra-thin volume of piezoelectric ceramic loudspeaker with in the sound chamber could solve the harsh requirement of present ultra thin handset to the space.Shown in the sound chamber design diagram 2 of piezoelectric ceramic loudspeaker in portable terminal is used.As shown in the figure, with the mobile phone is example, and piezoelectric ceramic loudspeaker 7 is positioned between hand set machine shell 1 and the casing PCB (printed circuit board (PCB)) 2, and the top of piezoelectric ceramic loudspeaker 7 is preceding sound chamber 51, the below is sound chamber, back 52, and this piezoelectric ceramic loudspeaker 7 is fixing by framework 3 and installation foam 4.
In order better to embody the saving of ceramic loudspeaker, use ventional loudspeakers and piezoelectric ceramic loudspeaker to compare to same mainboard to the space.Ventional loudspeakers is because thickness is 4.2mm, so can only be put on the mainboard.Like this, if the ventional loudspeakers that diameter is 18mm, the mainboard area that it takies adds that the young pathbreaker of area that sound chamber and sound chamber wall take reaches 400mm
2, can cause on the hardware like this is to be difficult to goods of furniture for display rather than for use.And ceramic loudspeaker thickness has only 1.00mm, and the situation after being put into above the radome is opposite with the situation of using ventional loudspeakers, and the space that the sound chamber requires adds the upper speaker body above radome, and thickness is less than 2.0mm.Radome+ceramic loudspeaker+sound chamber, about 4mm is far smaller than the height (height of 3.5mm earphone is 4.85mm) of the 3.5mm earphone of standard.Space under saving tightly can not increase the components and parts with other functions, and can make layout more smooth and easy, has not only guaranteed attractive in appearancely, has more improved performance.
Piezoelectric ceramic loudspeaker can sounding, and loud speaker must have outside power amplifier driving action.Meritorious being placed with much of using at present, for example: NS/LM48556, TI/TPA2100, SI-EN/SN4915.With reference to figure 5, the use in portable terminal of piezoelectric ceramic loudspeaker and power amplifier is described.
Portable terminal described in the utility model, it comprises base band 8, audio frequency amplifier 9 is used to amplify from the simulated audio signal of base band and with its output; And piezoelectric ceramic loudspeaker 10, be used to receive the audio signal of audio frequency amplifier output and be translated into voice signal output; Wherein, the audio output of this base band 8 links to each other with the input of this audio frequency amplifier 9, and the output of this audio frequency amplifier 9 links to each other with the input of this piezoelectric ceramic loudspeaker 10.The implementation case adopts the LM4856 chip of national semiconductor (Nationalsemiconductor) as audio frequency amplifier, and those skilled in the art also can select the chip of other models according to actual needs.
Preferably, audio output AUDIO_OUTL, the AUDIO_OUTR of this base band 8 are by input resistance R
InWith input capacitance C
InBe connected to input IN+, the IN-of this audio frequency amplifier 9, the output of this audio frequency amplifier 9 is by protective resistance R
Out1, R
Out2Be connected to the input of this piezoelectric ceramic loudspeaker 10, be connected with feedback resistance R between input IN+, the IN-of this audio frequency amplifier 9 and output OUT+, the OUT-
F1And R
F2
Preferably, the charge pump output voltage end PVSS of this audio frequency amplifier is by a reference capacitance C
RefGround connection.Preferably, the low level the RESET input/SD of this audio frequency amplifier links to each other with the GPIO interface of this base band.More preferably, the charge pump pumping capacitance cathode CP of this audio frequency amplifier and charge pump pumping electric capacity negative pole CN are by a boost capacitor C
PNLink to each other.
The cut-off frequency f of piezoelectric ceramic loudspeaker
In=R
In* C
In=33nF*50K=100Hz.R
F1And R
F2Be feedback resistance 200K Ω, multiplication factor AV=R
f/ R
In=200K Ω/50K Ω=4.R
Out1, R
Out2Protective resistance as a pair of piezoelectric ceramic loudspeaker.Because piezoelectric ceramic loudspeaker is capacitive loud speaker, impedance operator (Z=1/2*Pi*f*C) according to electric capacity, when loud speaker is exported high-frequency sound, just f is big more, the equivalent resistance of ceramic loudspeaker is just more little, electric current by loud speaker is just big more like this, thereby may cause loud speaker to burn.Take place for fear of this situation, protect so increase by two 10 Ω resistance at the piezoelectric ceramic loudspeaker two ends.Boost capacitor C
PNBe the boost capacitor of using for audio frequency amplifier internal capacitance pump, present embodiment is selected 10 μ F.Reference capacitance C
RefBe the reference capacitance that audio frequency amplifier internal capacitance pump charge pump uses, present embodiment is selected 10 μ F.Along with the signal of base band BB input different frequency, the inner driving voltage that produces different frequency that amplifies of audio frequency amplifier sends different sound thereby drive piezoelectric ceramic loudspeaker.
Select for use when driving power amplifier, the piezoelectric ceramic loudspeaker front can add LC or RC filter circuit, on the one hand can dividing potential drop, can reduce the EMI electromagnetic interference on the one hand.If do double horn, calculate the capacitive load of piezoelectric ceramic loudspeaker, drive the power amplifier maximum capacitive loads of supporting must be than the height of outside more.The piezoelectric ceramic loudspeaker body is relatively more fragile, will note its maximum vibration amplitude during structural design, does not interfere with the device of periphery when guaranteeing piezoelectric ceramic loudspeaker work, prevents to damage.
Though more than described embodiment of the present utility model, it will be understood by those of skill in the art that these only illustrate, protection range of the present utility model is limited by appended claims.Those skilled in the art can make numerous variations or modification to these execution modes under the prerequisite that does not deviate from principle of the present utility model and essence, but these changes and modification all fall into protection range of the present utility model.
Claims (5)
1. portable terminal, it comprises base band, it is characterized in that, this portable terminal also comprises:
Audio frequency amplifier is used to amplify from the simulated audio signal of base band and with its output;
Piezoelectric ceramic loudspeaker is used to receive the audio signal of audio frequency amplifier output and is translated into voice signal output;
Wherein, the audio output of this base band links to each other with the input of this audio frequency amplifier, and the output of this audio frequency amplifier links to each other with the input of this piezoelectric ceramic loudspeaker.
2. portable terminal as claimed in claim 1; it is characterized in that; the audio output of this base band is connected to the input of this audio frequency amplifier by a plurality of input resistances and a plurality of input capacitance; the output of this audio frequency amplifier is connected to the input of this piezoelectric ceramic loudspeaker by a plurality of protective resistances, is connected with a plurality of feedback resistances between the input of this audio frequency amplifier and the output.
3. portable terminal as claimed in claim 2 is characterized in that, the charge pump output voltage end of this audio frequency amplifier is by a reference capacitance ground connection.
4. portable terminal as claimed in claim 3 is characterized in that, low level the RESET input of this audio frequency amplifier links to each other with the GPIO interface of this base band.
5. portable terminal as claimed in claim 4 is characterized in that, the charge pump pumping capacitance cathode of this audio frequency amplifier links to each other by a boost capacitor with charge pump pumping electric capacity negative pole.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010202498659U CN201717918U (en) | 2010-07-06 | 2010-07-06 | Mobile terminal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010202498659U CN201717918U (en) | 2010-07-06 | 2010-07-06 | Mobile terminal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201717918U true CN201717918U (en) | 2011-01-19 |
Family
ID=43463926
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010202498659U Expired - Fee Related CN201717918U (en) | 2010-07-06 | 2010-07-06 | Mobile terminal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201717918U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140064520A1 (en) * | 2012-08-31 | 2014-03-06 | Pantech Co., Ltd. | Terminal with a piezoelectric speaker system and method for operating thereof |
| CN103686494A (en) * | 2013-12-11 | 2014-03-26 | 华为终端有限公司 | Electronic apparatus |
| CN107318075A (en) * | 2017-08-30 | 2017-11-03 | 盐城工学院 | A kind of audio frequency apparatus |
-
2010
- 2010-07-06 CN CN2010202498659U patent/CN201717918U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140064520A1 (en) * | 2012-08-31 | 2014-03-06 | Pantech Co., Ltd. | Terminal with a piezoelectric speaker system and method for operating thereof |
| CN103686494A (en) * | 2013-12-11 | 2014-03-26 | 华为终端有限公司 | Electronic apparatus |
| CN103686494B (en) * | 2013-12-11 | 2017-11-24 | 华为终端（东莞）有限公司 | A kind of electronic equipment |
| CN107318075A (en) * | 2017-08-30 | 2017-11-03 | 盐城工学院 | A kind of audio frequency apparatus |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110119 Termination date: 20140706 |
|
| EXPY | Termination of patent right or utility model |