CN101847358A - Gamma reference voltage generating device - Google Patents
Gamma reference voltage generating device Download PDFInfo
- Publication number
- CN101847358A CN101847358A CN200910081007A CN200910081007A CN101847358A CN 101847358 A CN101847358 A CN 101847358A CN 200910081007 A CN200910081007 A CN 200910081007A CN 200910081007 A CN200910081007 A CN 200910081007A CN 101847358 A CN101847358 A CN 101847358A
- Authority
- CN
- China
- Prior art keywords
- reference voltage
- gamma
- gamma reference
- data
- module
- 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.)
- Pending
Links
Images
Landscapes
- Picture Signal Circuits (AREA)
Abstract
The invention discloses a gamma reference voltage generating device which comprises a storage module, a differential signal generating module, a gamma decoding module and a digital-to-analog conversion module, wherein the storage module is used for storing a plurality of M-bit data which are in one-to-one correspondence with gamma reference voltage; the differential signal generating module is used for reading the plurality of M-bit data and generating differential signals based on the plurality of M-bit data, wherein the differential signals are formed by alternating the M-bit data and (M+1)-bit identification codes; the gamma decoding module is used for decoding the differential signals based on the identification codes to generate a plurality of decoded M-bit data; and the digital-to-analog conversion module is used for converting the decoded M-bit data into the gamma reference voltage. The invention omits the complicated resistor string and capacitor design of the gamma reference voltage generating device in the prior art, and reduces the area of the circuit board.
Description
Technical field
The present invention relates to gamma reference voltage generating device, especially relate to and need not to adopt resistance string to generate the gamma reference voltage generating device of gamma reference voltage.
Background technology
Because LCD (LCD) has the advantage of thin, the in light weight and low electromagnetic of volume, is widely used gradually in recent years.
Existing LCD is made of module backlight, liquid crystal panel and LCD driving mechanism.The LCD driving mechanism that is used to drive LCD comprises module driver backlight (BLU Controller), time schedule controller (Timing Controller), gate driver (Gata Drivers), gamma electric voltage generating apparatus and data driver formations such as (Data Drivers).
Have a plurality of pixels (pixel) of arranging on the liquid crystal panel with matrix form.Each pixel is made up of the liquid crystal layer between color membrane substrates, array base palte and color membrane substrates and the array base palte.A plurality of liquid crystal molecules are filled in the cavity between color membrane substrates and the array base palte, form liquid crystal layer.And color membrane substrates and array base palte have electrode respectively, when respectively in the electrode application voltage of color membrane substrates and array base palte, make when having institute's making alive between color membrane substrates and array base palte, the arrangement mode of the liquid crystal molecule in the liquid crystal layer can change along with the alive size of institute.And the arrangement mode of liquid crystal molecule can influence the ratio of light penetration pixel, is referred to as light transmission (light transmissivity).The size of light transmission has determined the brightness of pixel.Light transmission is big more, and the brightness of pixel is just big more.So, can make pixels different on the LCD screen have different brightness by institute's making alive size of control color membrane substrates and array base palte.
Fig. 1 is the color membrane substrates of pixel and the gamma curve graph of a relation of institute's making alive between array base palte and light transmission.Institute's making alive and light transmission between the color membrane substrates of pixel and array base palte are not linear, but the relation of gamma curve as shown in Figure 1.So claim that the color membrane substrates of pixel and the institute's making alive between array base palte are gamma electric voltage V
GM(being driving voltage).In addition, the light transmission of pixel is only relevant with the size of gamma electric voltage, and irrelevant with the polarity of gamma electric voltage.Therefore, gamma curve is by being the center with the ordinate, and the gamma curve 104 of symmetrical positive polarity gamma curve 102 and negative polarity is formed.If a certain pixel is imported two respectively size is identical but gamma electric voltage that polarity is different, then this pixel can have identical light transmission.If supply with the gamma electric voltage of the same polarity of each pixel constantly, can cause the damage of pixel liquid crystal molecule.Therefore, can protect liquid crystal molecule by the polarity of the gamma electric voltage that alternatively changes pixel.
The pixel data of general input LCD is binary numerical data.Because the light transmission of gamma electric voltage and pixel is nonlinear gamma curve relation, therefore, LCD needs special circuit arrangement, be used for concerning according to gamma curve, convert the pixel data of digital format to output corresponding driving voltage to array base palte, make the value of pixel data and the light transmission of pixel be the linear ratio relation.Above-mentioned operation is called as gamma correction (gamma correction), is used to improve the image display quality of LCD screen.
Fig. 2 is the synoptic diagram of gamma correction principle.When carrying out gamma correction, at first choose a plurality of pixel datas as the reference pixel data.In Fig. 2, with pixel data D0, D1, D2, D3 and D4 as the reference pixel data.According to gamma curve, each reference pixel data can be distinguished a corresponding positive polarity gamma reference voltage and a negative polarity gamma reference voltage.With reference pixel data D0 is example, and it is a corresponding positive polarity gamma reference voltage V0 and a negative polarity gamma reference voltage V9 respectively.In like manner, 5 reference pixel data D0, D1, D2, D3 and D4 correspond to respectively 5 positive polarity gamma reference voltage V0, V1, V2, V3, with V4 and 5 negative polarity gamma reference voltage V9, V8, V7, V6 and V5, as shown in Figure 2.Described by preamble, general pixel data (DATA) is the binary data of 8bit, can represent 256 gray levels altogether.When carrying out gamma correction, just the corresponding relation with reference pixel data and gamma reference voltage is as the criterion, and utilizes interpolation method to try to achieve the corresponding respectively driving voltage of other all pixel datas, i.e. gamma electric voltage.Wherein, each pixel data all can be distinguished a corresponding positive polarity gamma driving voltage and a negative polarity gamma driving voltage.
Be noted that selected reference pixel data number is many more, when carrying out gamma correction, the pairing driving voltage of each pixel data is just accurate more, generally chooses 8 reference pixel data and carries out gamma correction.According to gamma curve, 8 respectively corresponding 8 positive polarity gamma reference voltages of reference pixel data and 8 negative polarity gamma reference voltages.The data driver of being responsible for the operation of execution gamma correction promptly is as the criterion with these 16 gamma reference voltages and carries out gamma correction.
Fig. 3 is the synoptic diagram of traditional gamma correcting device.As shown in Figure 3, gamma correcting device is formed by connecting by data driver 302 and gamma reference voltage generating device 301.Gamma reference voltage generating device 301 has a resistance string that is in series by 17 resistance r1～r17.Two nodes of the head and the tail of this resistance string are connected with voltage source 303 respectively.By the resistance value of suitably controlling each resistance, make each node of resistance string distinguish output reference voltage Vr, comprising 8 positive polarity gamma reference voltage Vr (+) and 8 negative polarity gamma reference voltage Vr (-).Each gamma reference voltage Vr exports in the data driver 302 through impact damper BUF respectively.Data driver 302 is as the criterion with described reference voltage Vr, uses interpolation method that each pixel data is carried out gamma correction respectively, exports corresponding gamma electric voltage V
GMGamma reference voltage Vr gets ground voltage (GND) to the value between the liquid crystal drive voltage (AVDD).
Because, the tradition gamma reference voltage generating device utilizes the principle of electric resistance partial pressure to export one group of gamma reference voltage Vr to carry out gamma correction for data driver, the size of therefore having to increase circuit board is provided with these resistance string, make that the circuit board volume is big, be unsuitable for the trend of lightening development.
Summary of the invention
The purpose of this invention is to provide a kind of gamma reference voltage generating device, can reduce the size of drive circuit board.
For achieving the above object, the invention provides a kind of gamma reference voltage generating device, it comprises:
Memory module is used for storage and a plurality of one to one M Bit datas of gamma reference voltage;
The differential signal generation module is used to read described a plurality of M Bit data, and generates differential signals according to described a plurality of M Bit datas, described differential signal by described M Bit data and (M+1) identification code of bit alternately form;
Gamma decoding module is used for generating a plurality of decoded M-bit data according to the described identification code described differential signal of decoding;
D/A converter module is used for described a plurality of decoded M-bit data are converted to gamma reference voltage.
The present invention stores the data corresponding with gamma reference voltage in advance by memory module, the data-signal conversion is generated the gamma reference voltage of simulation by D/A converter module, the resistance string and the capacitor design of the complexity of prior art have been saved, reduced the area of circuit board, and the gamma reference voltage that generates is more stable than prior art, accurately, controllability strengthens.
Description of drawings
Fig. 1 is color membrane substrates and the institute's making alive of array base palte and the gamma curve graph of a relation of light transmission of pixel;
Fig. 2 is the synoptic diagram of gamma correction principle;
Fig. 3 is the synoptic diagram of traditional gamma correcting device;
Fig. 4 is the structural representation of gamma reference voltage generating device of the present invention;
Fig. 5 is the synoptic diagram of differential signal of the present invention.
Embodiment
Below by drawings and Examples, technical scheme of the present invention is described in further detail.
Fig. 4 is the structural representation of gamma reference voltage generating device of the present invention.As shown in Figure 4, gamma reference voltage generating device 401 of the present invention comprises: memory module 4010, differential signal generation module 4011 and gamma decoding module 4012 and D/A converter module 4013 are used for to a plurality of gamma reference voltage Vr of data driver 402 outputs.
Each gamma address in the memory module 4010 stores 2 system data of 8 bits (bit).General pixel data P
DBe the binary data of 8bit, can represent 256 gray levels altogether, so driving voltage V
GMAlso need 256.Usually, store data with 16 systems among the ROM.Memory module 4010 of the present invention also can be stored two 16 system data, and at this moment, memory module 4010 can also comprise first converter, and two 16 system data are converted to 8 Bit datas.
For example, the gamma reference voltage Vr that proofreaies and correct in advance is shown in following table one.Wherein Vr1-7 is low level Vr (-), and Vr7-14 is high level Vr (+).
| ??Vr 1＝0.34V | ??Vr 2＝1.18V | ??Vr 3＝2.16V | ??Vr 4＝3.42V | ??Vr 5＝4.56V | ??Vr 6＝5.64V | ??Vr 7＝6.25V |
| ??Vr 8＝7.82V | ??Vr 9＝8.86V | ??Vr 10＝9.36V | ??Vr 11＝10.32V | ??Vr 12＝11.39V | ??Vr 13＝12.78V | ??Vr 14＝13.49V |
Then, being provided with of the gamma address, inside of memory module can be shown in following table two.
| ??GMA1＝22 | ??GMA2＝12 | ??GMA3＝10 | ??GMA4＝2A | ??GMA5＝38 | ??GMA6＝40 | ??GMA7＝19 |
| ??GMA8＝52 | ??GMA9＝56 | ??GMA10＝24 | ??GMA11＝20 | ??GMA12＝27 | ??GMA13＝4E | ??GMA14＝31 |
As shown in Table 2, the GMA1 internal memory contains " 22 " of 16 systems, and 8 bits, the 2 system data that " 22 " of 16 systems are converted to are " 00100010 ", is converted to 10 systems and is " 34 ".
Fig. 5 is the synoptic diagram of differential signal of the present invention.See also Fig. 4 and Fig. 5.
Differential signal generation module 4011 according to the clock signal clk of time schedule controller, reads a plurality of M Bit datas in the memory module 4010, and generates differential signal DS according to a plurality of M Bit datas.Differential signal DS can reach (M+1) by the M Bit data, and the identification code of bit alternately forms.
When M was 8 bits, the differential signal of generation was that the data of 8 bits and the identification code of 9 bits replace the signal that forms.Identification code can be the 9 bit blank signals (BLANK) that are made of 9 " 0 ", is used for the data separation with 8 bits.Differential signal can have the amplitude of 100mV-400mV, and reference voltage can be 0.8-1.5V.
D/A converter module 4013 is used for a plurality of decoded M-bit data are converted to gamma reference voltage Vr.D/A converter module 4013 can comprise second converter and generation unit.Second converter is used for decoded M-bit data is converted to the discernible 10 system data of digital to analog converter.Generation unit is used to generate the gamma reference voltage corresponding with 10 data-signals.For example, gamma decoding module 4012 has identified the GMA1 " 00100010 " among the differential signal DS, and transmit it to D/A converter module 4013, second converter is converted to " 00100010 " " 34 " of 10 systems, generation unit will generate simulating signal " 0.34V " by data " 34 ", and export data driver 402 to by impact damper (BUF).
The present invention stores the data corresponding with gamma reference voltage in advance by memory module, the data-signal conversion is generated the gamma reference voltage of simulation by D/A converter module, the resistance string and the capacitor design of the complexity of prior art have been saved, reduced the area of circuit board, and the gamma reference voltage that generates is more stable than prior art, accurately, controllability strengthens.
It should be noted that at last: above embodiment is only in order to technical scheme of the present invention to be described but not limit it, although the present invention is had been described in detail with reference to preferred embodiment, those of ordinary skill in the art is to be understood that: it still can make amendment or be equal to replacement technical scheme of the present invention, and these modifications or be equal to replacement and also can not make amended technical scheme break away from the spirit and scope of technical solution of the present invention.
Claims (4)
1. a gamma reference voltage generating device is characterized in that, comprising:
Memory module is used for storage and a plurality of one to one M Bit datas of gamma reference voltage;
The differential signal generation module is used to read described a plurality of M Bit data, and generates differential signals according to described a plurality of M Bit datas, described differential signal by described M Bit data and (M+1) identification code of bit alternately form;
Gamma decoding module is used for generating a plurality of decoded M-bit data according to the described identification code described differential signal of decoding;
D/A converter module is used for described a plurality of decoded M-bit data are converted to gamma reference voltage.
2. gamma reference voltage generating device according to claim 1 is characterized in that: described M is 8.
3. gamma reference voltage generating device according to claim 1 is characterized in that: described memory module comprises:
Storage unit, the 16 system data that cell stores is a plurality of two;
First converter is used for described 16 system data are converted to the data of 8 bits.
4. gamma reference voltage generating device according to claim 1 is characterized in that, described D/A converter module comprises:
Second converter is used for described decoded M-bit data is converted to the discernible 10 system data of digital to analog converter;
Generation unit is used to generate and the corresponding gamma reference voltage of 10 system data.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910081007A CN101847358A (en) | 2009-03-27 | 2009-03-27 | Gamma reference voltage generating device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910081007A CN101847358A (en) | 2009-03-27 | 2009-03-27 | Gamma reference voltage generating device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101847358A true CN101847358A (en) | 2010-09-29 |
Family
ID=42771964
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200910081007A Pending CN101847358A (en) | 2009-03-27 | 2009-03-27 | Gamma reference voltage generating device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101847358A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105118455A (en) * | 2015-08-31 | 2015-12-02 | 昆山龙腾光电有限公司 | Gamma voltage generation device, method and liquid crystal display |
| CN106297703A (en) * | 2016-08-31 | 2017-01-04 | 深圳市华星光电技术有限公司 | Gamma electric voltage generative circuit and liquid crystal display |
| CN107256698A (en) * | 2013-12-06 | 2017-10-17 | 矽创电子股份有限公司 | The drive circuit and its drive module of display panel and display device and manufacture method |
| WO2017181483A1 (en) * | 2016-04-19 | 2017-10-26 | 深圳市华星光电技术有限公司 | Driving system and driving method for liquid crystal display and liquid crystal display |
| CN111028808A (en) * | 2019-12-24 | 2020-04-17 | 惠州市华星光电技术有限公司 | Method, device and system for adjusting brightness and visual angle of liquid crystal panel and display device |
| CN116743124A (en) * | 2023-06-28 | 2023-09-12 | 上海极海盈芯科技有限公司 | Threshold value generation circuit, chip and device |
-
2009
- 2009-03-27 CN CN200910081007A patent/CN101847358A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107256698A (en) * | 2013-12-06 | 2017-10-17 | 矽创电子股份有限公司 | The drive circuit and its drive module of display panel and display device and manufacture method |
| CN105118455A (en) * | 2015-08-31 | 2015-12-02 | 昆山龙腾光电有限公司 | Gamma voltage generation device, method and liquid crystal display |
| CN105118455B (en) * | 2015-08-31 | 2018-01-16 | 昆山龙腾光电有限公司 | Gamma voltage generating device and method, liquid crystal display |
| WO2017181483A1 (en) * | 2016-04-19 | 2017-10-26 | 深圳市华星光电技术有限公司 | Driving system and driving method for liquid crystal display and liquid crystal display |
| US10186214B2 (en) | 2016-04-19 | 2019-01-22 | Shenzhen China Star Optoelectronics Technology Co., Ltd | Driving system and driving method of liquid crystal display device and liquid crystal display device |
| CN106297703A (en) * | 2016-08-31 | 2017-01-04 | 深圳市华星光电技术有限公司 | Gamma electric voltage generative circuit and liquid crystal display |
| CN106297703B (en) * | 2016-08-31 | 2018-12-07 | 深圳市华星光电技术有限公司 | Gamma electric voltage generative circuit and liquid crystal display |
| CN111028808A (en) * | 2019-12-24 | 2020-04-17 | 惠州市华星光电技术有限公司 | Method, device and system for adjusting brightness and visual angle of liquid crystal panel and display device |
| CN116743124A (en) * | 2023-06-28 | 2023-09-12 | 上海极海盈芯科技有限公司 | Threshold value generation circuit, chip and device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101847358A (en) | Gamma reference voltage generating device | |
| KR101034533B1 (en) | video display driver with Gamma Control | |
| KR100993813B1 (en) | Video display driver with data enable learning | |
| CN104091558A (en) | LED display panel driving method and system | |
| US7663586B2 (en) | Reference voltage generation circuit, display driver, electro-optical device, and electronic instrument | |
| US8054266B2 (en) | Display device, driving apparatus for display device, and driving method of display device | |
| KR20090031342A (en) | Video display driver with partial memory control | |
| EP2071550A2 (en) | Data driving device and liquid crystal display device using the same | |
| KR20080036442A (en) | Data driving apparatus, liquid crystal display comprising the same and method for driving of liquid crystal display | |
| JP2005338763A (en) | Display device | |
| KR20030067574A (en) | Reference voltage generation circuit, display drive circuit, display device and reference voltage generation method | |
| CN104821828B (en) | Low pressure digital analogue signal conversion circuit, data drive circuit and display system | |
| CN101162571B (en) | Liquid crystal display and method of driving the same | |
| CN102456335A (en) | Liquid crystal display device and driving method of the same | |
| JP2007288787A (en) | Digital-to-analog converter and driving method of display device | |
| US20060198009A1 (en) | Reference voltage generation circuit, display driver, electro-optical device, and electronic instrument | |
| KR102198366B1 (en) | Data Driver and Display Device Using the same | |
| US8223141B2 (en) | System and method for driving displays with single latch pixels | |
| EP2193517A2 (en) | Display driving integrated circuit and display driving system | |
| TW201307974A (en) | Display panel and operating method thereof | |
| CN1150502C (en) | System and method for reducing inter-pixel distortion by dynamic redefinition of display segment boundaries | |
| US8416165B2 (en) | Display device capable of receiving and manipulating image signals having different bit sizes | |
| CN101303834B (en) | Digital-to-analog converter | |
| CN116092406A (en) | Gamma voltage curve adjusting method and equipment | |
| US20140055437A1 (en) | Digital-to-analog converter, display driving circuit having the same, and display apparatus having the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20100929 |