CN101894528B - Method for modulating common signal of liquid crystal display - Google Patents
Method for modulating common signal of liquid crystal display Download PDFInfo
- Publication number
- CN101894528B CN101894528B CN2009101433339A CN200910143333A CN101894528B CN 101894528 B CN101894528 B CN 101894528B CN 2009101433339 A CN2009101433339 A CN 2009101433339A CN 200910143333 A CN200910143333 A CN 200910143333A CN 101894528 B CN101894528 B CN 101894528B
- Authority
- CN
- China
- Prior art keywords
- frequency
- common signal
- modulation
- lcd
- fvcom
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000000034 method Methods 0.000 title claims abstract description 11
- 239000004973 liquid crystal related substance Substances 0.000 title abstract description 4
- 238000000926 separation method Methods 0.000 claims description 11
- 238000010586 diagram Methods 0.000 description 12
- 238000004891 communication Methods 0.000 description 2
- 230000005534 acoustic noise Effects 0.000 description 1
- 210000005069 ears Anatomy 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005236 sound signal Effects 0.000 description 1
Images
Landscapes
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
Abstract
The invention relates to a method for modulating a common signal of a liquid crystal display. A drive circuit of the liquid crystal display comprises a common signal generator and a modulation circuit, wherein the modulation circuit can generate a first frequency, a second frequency and a third frequency; and the common signal generator generates a swinging common signal according to the first frequency and modulates the frequency of the common signal inside the frequency interval of the second frequency and the third frequency.
Description
Technical field
The present invention is relevant to a kind of method that produces the common signal of LCD, refers to a kind of method of common signal of modulation LCD especially.
Background technology
(liquid crystal display, (personal data assistant PDA) waits compact electronic device to LCD LCD) to be widely used in mobile phone or personal digital assistant.Mobile phone or personal digital assistant need show image and audio signal; Therefore; The audio-frequency noise (acoustic noise) that the screen flicker of LCD (flicker) and LCD produce also must reduce as far as possible, just can not influence the demonstration that mobile phone or personal digital assistant provide and the quality of communication.
Please refer to Fig. 1, Fig. 1 is the synoptic diagram of common signal generator of the LCD of prior art.The common signal generator 12 of LCD produces the common signal VCOM of swing (swing) according to a high levle voltage VCOMH, a low level voltage VCOML and a frequency signal CLK.General undersized LCD all uses the common signal VCOM of swing, and it is the voltage waveform of fixed frequency, fixing accurate position.Because the common signal VCOM of swing is for exchanging (AC) voltage, so the frequency dependence of the audio-frequency noise that is produced during the LCD running and common signal VCOM.If the resolution of LCD is QVGA (240*RGB*320), then the frequency of the common signal VCOM of LCD can be calculated as follows:
Please refer to Fig. 2, Fig. 2 is time-domain diagram and the frequency domain figure of the common signal VCOM of Fig. 1.Among Fig. 2, (A) part is the time-domain diagram of common signal VCOM, and horizontal ordinate is the time, and ordinate is a frequency; (B) part is the frequency domain figure of common signal VCOM, and horizontal ordinate is a frequency, and ordinate is intensity (unit is dB); FVCOM representes the frequency of common signal.Time-domain diagram by common signal VCOM can know that common signal VCOM has fixed frequency FVCOM, therefore, can be known by the frequency domain figure of common signal VCOM that the energy of audio-frequency noise can be accumulated in this fixed frequency FVCOM.Likewise, be example with the LCD of resolution QVGA (240*RGB*320), the frequency of its common signal VCOM is about 9.6KHz, so the energy of audio-frequency noise can be accumulated in 9.6KHz.
Normal human ear can hear the sound of 20Hz to the 20KHz hertz frequency, so 20Hz is called " auditory frequency range " to the scope of 20KHz.The human ear is depended on the frequency of sound to the susceptibility of sound, especially responsive especially to the noise of this part of 12KHz hertz for 8KHz, also is prone to discover.Though frequency is that the audio-frequency noise that common signal caused of 9.6KHz is little,, still can clearly experience the interference of the audio-frequency noise of LCD generation if the user moves to ear nearby with LCD.Above-mentioned situation most probable occurs in after the user answers the call or make a phone call, and mobile phone or personal digital assistant are moved to ears to converse, and at this moment, LCD produces audio-frequency noise just can influence communication quality.
Summary of the invention
Therefore, the object of the present invention is to provide a kind of method of common signal of modulation LCD, to solve the above problems.
The present invention provides a kind of method of common signal of modulation LCD, and comprising provides a first frequency; Produce the common signal of a swing according to this first frequency; Produce a second frequency and one the 3rd frequency according to this first frequency; Reach the frequency of this common signal of modulation in the frequency separation of this second frequency and the 3rd frequency.
The present invention provides a kind of driving circuit of LCD in addition, comprises a common signal generator and a modulation circuit.This common signal generator produces the common signal of a swing according to high levle voltage and a low level voltage.This modulation circuit is electrically connected at this common signal generator, is used for the frequency of this common signal of modulation.
The present invention produces under the framework of common signal at original LCD, utilizes the frequency of modulation common signal to make the resonance frequency range of LCD produce change, uses and reduces the audio-frequency noise that original single-frequency produced.The driving circuit of LCD of the present invention comprises a common signal generator and a modulation circuit.This common signal generator is used for producing a common signal.This modulation circuit is electrically connected at this common signal generator, is used for the frequency of this common signal of modulation.This modulation circuit can produce a first frequency, a second frequency and one the 3rd frequency.This common signal generator produces the common signal of a swing according to this first frequency, and in the frequency separation of this second frequency and the 3rd frequency the frequency of this common signal of modulation.Therefore, the driving circuit of LCD of the present invention can improve the audio-frequency noise that frequency caused of common signal.
Description of drawings
Fig. 1 is the synoptic diagram of common signal generator of the LCD of prior art.
Fig. 2 is the time-domain diagram and the frequency domain figure of the common signal of Fig. 1.
Fig. 3 is the synoptic diagram of the driving circuit of LCD of the present invention.
Fig. 4 is the time-domain diagram and the frequency domain figure of the common signal of Fig. 3.
Embodiment
In the middle of instructions and above-mentioned claim, used some vocabulary to censure specific assembly.Having common knowledge the knowledgeable in the affiliated field should understand, and same assembly may be called with different nouns by manufacturer.This instructions and above-mentioned claim are not used as distinguishing the mode of assembly with the difference of title, but the benchmark that is used as distinguishing with the difference of assembly on function.Be an open term mentioned " comprising " in the middle of instructions and the above-mentioned claim in the whole text, so should be construed to " comprise but be not limited to ".In addition, " electric connection " speech is to comprise any indirect means that are electrically connected that directly reach at this.Therefore, be electrically connected at one second device, then represent this first device can be directly connected in this second device, or be connected to this second device through other device or the intersegmental ground connection of connection hand if describe one first device in the literary composition.
Please refer to Fig. 3, Fig. 3 is the synoptic diagram of the driving circuit of LCD of the present invention.Driving circuit 30 comprises a common signal generator 32 and a modulation circuit 34.Common signal generator 32 produces the common signal VCOM of swing (swing) according to a high levle voltage VCOMH and a low level voltage VCOML.Modulation circuit 34 is used for the frequency of modulation common signal VCOM.The common signal VCOM output shows signal of LCD after according to this modulation.Modulation circuit 34 is used to provide a first frequency FVCOM, and common signal generator 32 produces common signal VCOM according to first frequency FVCOM.Then; Modulation circuit 34 produces a second frequency FVCOM+ Δ f and one the 3rd frequency FVCOM-Δ f according to first frequency, and the common signal VCOM that modulation produces according to first frequency in the frequency separation of second frequency FVCOM+ Δ f and the 3rd frequency FVCOM+ Δ f.In the present embodiment, modulation circuit 34 provides a first frequency FVCOM, and produces the second frequency FVCOM+ Δ f greater than first frequency FVCOM according to first frequency FVCOM, reaches the 3rd frequency FVCOM-Δ f less than first frequency FVCOM.Common signal generator 32 can produce the common signal VCOM of different frequency according to first frequency FVCOM, second frequency FVCOM+ Δ f and the 3rd frequency FVCOM-Δ f.For example; Common signal generator 32 produces the common signal VCOM of second frequency FVCOM+ Δ f at the first period t1; At the common signal VCOM of second period t2 generation first frequency FVCOM, produce the common signal VCOM of the 3rd frequency FVCOM-Δ f at the 3rd period t3.Moreover common signal generator 32 also can produce the common signal VCOM of different frequency in the frequency separation of second frequency FVCOM+ Δ f and the 3rd frequency FVCOM-Δ f.
Common signal generator compared to prior art; The human ear hears the audio-frequency noise that fixed frequency produced of common signal VCOM easily; Therefore in the present invention; Utilize modulation circuit 34 to produce different frequency, common signal generator 32 can produce the common signal VCOM of different frequency according to the frequency that modulation circuit 34 is provided, and makes the inner resonance frequency range of LCD produce and changes; The decibel value (dB) of the vibrating noise that reduces original single-frequency by this and produced, and this mode can't change any processing procedure and the structure of LCD.Certainly, after the frequency of modulation common signal VCOM, the drive signal of LCD also must follow the common signal VCOM after the modulation frequency to adjust.
Please refer to Fig. 4, Fig. 4 is time-domain diagram and the frequency domain figure of the common signal VCOM of Fig. 3.Among Fig. 4, (A) part is the time-domain diagram of common signal VCOM, and horizontal ordinate is the time, and ordinate is a frequency; (B) part is the frequency domain figure of common signal VCOM, and horizontal ordinate is a frequency, and ordinate is intensity (unit is dB); FVCOM, FVCOM+ Δ f and FVCOM-Δ f represent the frequency of common signal.Time-domain diagram by common signal VCOM can be known; The frequency of common signal VCOM is modulation in the frequency separation of frequency FVCOM+ Δ f and FVCOM-Δ f; Therefore, can know that the energy of audio-frequency noise can be scattered in the frequency separation of frequency FVCOM+ Δ f and FVCOM-Δ f by the frequency domain figure of common signal VCOM.The present invention adds modulation circuit 34 in the driving circuit 30 of LCD; The frequency of the common signal VCOM that produces with modulation common signal generator 32; Make common signal VCOM by fixed frequency FVCOM modulation to frequency separation FVCOM ± Δ f, therefore, in frequency domain figure; Energy will be dispersed to frequency separation FVCOM ± Δ f, can effectively reduce compared to the energy of accumulating in fixed frequency FVCOM place (shown in dotted line).
In sum, the present invention produces under the framework of common signal at original LCD, utilizes the frequency of modulation common signal to make the resonance frequency range of LCD produce change, uses and reduces the audio-frequency noise that original single-frequency produced.The driving circuit of LCD of the present invention comprises a common signal generator and a modulation circuit.This common signal generator is used for producing a common signal.This modulation circuit is electrically connected at this common signal generator, is used for the frequency of this common signal of modulation.This modulation circuit can produce a first frequency, a second frequency and one the 3rd frequency.This common signal generator produces the common signal of a swing according to this first frequency, and in the frequency separation of this second frequency and the 3rd frequency the frequency of this common signal of modulation.Therefore, the driving circuit of LCD of the present invention can improve the audio-frequency noise that frequency caused of common signal.
The above is merely preferred embodiment of the present invention, and all equalizations of doing according to claim of the present invention change and modify, and all should belong to covering scope of the present invention.
Claims (8)
1. the method for the common signal of a modulation LCD is characterized in that, comprises:
One first frequency is provided;
Produce the common signal of a swing according to this first frequency;
Produce a second frequency and one the 3rd frequency according to this first frequency, comprise: produce second frequency greater than this first frequency; And generation is less than the 3rd frequency of this first frequency; And
The frequency of this common signal of modulation in the frequency separation of this second frequency and the 3rd frequency comprises: export the common signal with the 3rd frequency in one first period; Output has the common signal of this first frequency in one second period; And the common signal that has this second frequency in one the 3rd period output.
2. the method for claim 1 is characterized in that, the common signal that produces this swing according to this first frequency comprises:
One high levle voltage and a low level voltage are provided; And
Be created in the common signal of swinging between this high levle voltage and this low level voltage according to this first frequency.
3. like request terms 1 described method, other comprises:
Shows signal according to this LCD of the adjustment of the common signal behind the modulation.
4. the driving circuit of a LCD is characterized in that, comprises:
One common signal generator produces the common signal of a swing according to high levle voltage and a low level voltage; And
One modulation circuit is electrically connected at this common signal generator, is used for the frequency of this common signal of modulation.
5. driving circuit as claimed in claim 4 is characterized in that, this LCD is according to the output of the common signal behind this modulation shows signal.
6. driving circuit as claimed in claim 4 is characterized in that, the common signal that this common signal generator produces has a first frequency.
7. driving circuit as claimed in claim 6 is characterized in that, this modulation circuit is to be used for producing a second frequency and the 3rd frequency less than this first frequency greater than this first frequency.
8. driving circuit as claimed in claim 7 is characterized in that, this modulation circuit is to be used for the frequency of in the frequency separation of this second frequency and the 3rd frequency this common signal of modulation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009101433339A CN101894528B (en) | 2009-05-21 | 2009-05-21 | Method for modulating common signal of liquid crystal display |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009101433339A CN101894528B (en) | 2009-05-21 | 2009-05-21 | Method for modulating common signal of liquid crystal display |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101894528A CN101894528A (en) | 2010-11-24 |
| CN101894528B true CN101894528B (en) | 2012-05-30 |
Family
ID=43103703
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009101433339A Expired - Fee Related CN101894528B (en) | 2009-05-21 | 2009-05-21 | Method for modulating common signal of liquid crystal display |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101894528B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8892374B2 (en) * | 2011-07-01 | 2014-11-18 | Intel Corporation | Identifying electrical sources of acoustic noise |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101105924A (en) * | 2002-11-04 | 2008-01-16 | 京东方显示器科技公司 | Common voltage adjustment circuit of liquid crystal display device |
| CN101197121A (en) * | 2007-12-29 | 2008-06-11 | 友达光电股份有限公司 | Liquid crystal display and its drive control circuit |
-
2009
- 2009-05-21 CN CN2009101433339A patent/CN101894528B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101105924A (en) * | 2002-11-04 | 2008-01-16 | 京东方显示器科技公司 | Common voltage adjustment circuit of liquid crystal display device |
| CN101197121A (en) * | 2007-12-29 | 2008-06-11 | 友达光电股份有限公司 | Liquid crystal display and its drive control circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101894528A (en) | 2010-11-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| RU2622109C2 (en) | Mobile device | |
| CN103347115B (en) | The method and apparatus of a kind of output volume controlling electronic product and a kind of mobile phone | |
| US10281958B2 (en) | Portable electronic device and pivoting assembly | |
| TW200910901A (en) | Adjusting device and method of notification sound according to the environment | |
| CN103369112A (en) | A mode management system and a management method thereof | |
| US8913752B2 (en) | Audio signal measurement method for speaker and electronic apparatus having the speaker | |
| JP2007502594A (en) | Display speaker | |
| CN101459414B (en) | Video and audio playing device and volume control method | |
| CN102780797A (en) | Mobile telephone and correction method of internal electroacoustic component thereof | |
| CN101783656A (en) | Loudness control method, module and device of stereo system | |
| CN109302525B (en) | Method for playing sound and multi-screen terminal | |
| CN103428593B (en) | The device of audio signal is gathered based on speaker | |
| US7683887B2 (en) | Display system | |
| CN101894528B (en) | Method for modulating common signal of liquid crystal display | |
| CN110691303B (en) | Wearable sound box and control method thereof | |
| CN103199602A (en) | Mobile terminal charging system and mobile terminal charging method | |
| CN111614829A (en) | An electronic device and anti-eavesdropping method | |
| CN202364332U (en) | Apparatus for improving mechanical vibration of flat television set | |
| CN207135242U (en) | A kind of wireless microphone with intelligent noise removal function | |
| TWI413076B (en) | Method of modulating a common signal of liquid crystal display | |
| WO2024037183A1 (en) | Audio output method, electronic device and computer-readable storage medium | |
| TWI419125B (en) | Method for reducing resonance energy of an lcd panel and related lcd device | |
| CN210181883U (en) | Experimental device for be used for exploring forced vibration and resonance phenomenon | |
| CN101887697B (en) | Method for reducing resonance energy of liquid crystal panel and liquid crystal display | |
| CN102421006A (en) | Method and device for improving vibration of flat-panel television |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| 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: 20120530 Termination date: 20170521 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |