Power drive circuit optically isolated

The microcomputer control system, a large number of applications is the control switch, the switch generally after the microcomputer I / O output, while the I / O drive capability is limited, usually not enough to drive the magnetic implementation of the device at some point, need to increase access drive interface circuits, TFT LCD Display in order to avoid computer disruptions quarantine measures to be taken. Such as thyristors where the main circuit is generally ac power circuits, high voltage, higher current, difficult with the computer is directly connected to the computer control signal applied coupler thyristor trigger circuit isolation.

The motor control circuit, can be applied to the coupler and the motor control circuit isolated from the high voltage circuit. Motor MOSFET or IGBT power transistor by driving current,8x2 lcd the power transistor switching control signal and the power amplification stage between the tubes to be isolated. In the optocoupler isolation level - amplifier stage - power tube connection form, requires optocoupler with high output voltage, high speed and high common mode rejection.

Optocoupler is what powerful

The reason why the optocoupler transmit signals at the same time can effectively suppress spikes and a variety of noise interference on the channel signal to noise ratio greatly improved, mainly the following reasons:
(1) optical coupler input impedance is very small, only a few hundred ohms, and the impedance of the source of interference is large, typically 105 ~ 106Ω. According to the principle known partial pressure, even if the interference voltage amplitude is large, SPI lcds but is fed to the optocoupler input noise voltage will be very small, only a very weak current form, because there is not enough energy without emitting diode can thus be inhibited out.
(2) optocouplers between input circuit and output circuit is not electrically connected, there is no common ground; distributed capacitance between the minimum and the insulation resistance is so big, so the loop side of the various interference noise is difficult to pass Optocoupler fed to the other side, a total impedance coupling to avoid interference signal generation.
(3) optocouplers security can play a very good role, even when the external device fails, serial 16x2 lcd even when the input signal line short circuit, it will not damage the instrument. Because optocoupler input circuits and parts between the output circuit can withstand several thousand volts of high voltage.
(4) optocoupler fast response, the response time of only 10μs delay about the response speed for demanding applications.

Solutions of reflection and transmission reflection

Reflective and transflective OLED Display brightness solutions to solve the problem is an effort to take advantage of the surrounding light. More than half of the energy consumption of the backlight on the display, thus reducing or removing the backlight will greatly extend the battery life, or to significantly reduce the device weight. Like Palm and Compaq iPAQ PDA, etc. often use reflective displays. This means that around the entering light from the front of the display, through the polarization liquid crystal layer, and finally reaches the reflecting layer, then it is reflected again, form a visible image. It is estimated that about 84% of the light is absorbed on the way, so in fact you only see 1/6 of the reflected light. This requires improvement, but still be able to provide sufficient contrast so as to form a visible image. However, if the lack of outside light how to do? You need to provide an auxiliary light so you can see the image.

Some devices (e.g. Palm) is "reflectance and transmittance (transreflective)", and their one-way light reflecting through which only the reflective layer. But this is not a particularly efficient design, there are still a lot of light is reflected away. Another attempt to illuminate the front layer is reflective screen, as used herein CompaqiPAQH3600. Light from the light source edge of the display panel, along the surface of the panel transmission, followed by a wedge-shaped diffuser screen is vertically directed. This provides sufficient light panel light required, ultimately produce a visible image. Transmission reflection and reflection in a wider Low Temperature Display makes using the LCD monitor lighting conditions possible, but it consumes very little energy.

Polyimide slow development of several important factors

A process for producing a polyimide prepared from: pyromellitic dianhydride insufficient purity.
2 pyromellitic dianhydride starting material durene production is limited. International Production: 60,000 tons / year,OLED Module domestic production: 5000 tons / year.
3 pyromellitic dianhydride production costs are too high, the international community about 1.2-1.4 t durene produce 1 ton of pyromellitic dianhydride, and our current best manufacturers around 2.0-2.25 tons produced a durene t, only the federal Chemical Co., Ltd. Changshu reached 1.6 tons / ton.
4 polyimide are too small, lcd module it is difficult to form industry, polyimide side reactions and complex.
5 most domestic enterprises demand the traditional sense, the application surface is limited to a range of habitual seen first with foreign products or foreign products sought after in the country. The business needs from the enterprise's downstream customers needs, sources of information feedback and poor, the middle part and more accurate information out of shape volume.

Effect for TFT-LCD glass substrate main physical characteristics

Glass substrate TN / STN, TFT-LCD applications, the required characteristics of surface properties ﹑ ﹑ chemical resistance, heat resistance, and alkali metal content, etc.; these only affect the glass substrate for TFT-LCD of the main physical properties are described below :
1 Tension Point (Strain Point): is the glass density plot of an indicator shall be resistant Optoelectronics LCD production process of high temperature.

(2) Specific gravity: for TFT LCD Display, the notebook is currently the largest market, so the density of the glass substrate as small as possible in order to transport and carry.

3 Thermal expansion coefficient: The coefficient determines the glass caused by temperature changes due to expansion or contraction of the appearance of the size scale, the coefficients as low as possible, so that the large screen of the expansion and contraction to a minimum.

The rest of the physical characteristics of indicators are still melting, softening point, chemical resistance, mechanical strength, optical properties and electrical properties, etc., can according to the user's specific needs to be regulated.

The glass substrate manufacturing process, the main techniques include feed back-sheet forming and processing of three parts, wherein the feed formulation technology mainly in the quality control, the first glass in the high temperature furnace will be a low viscosity material melting and uniform molten glass, not only to consider the physical and chemical properties of the glass, and the need not change the chemical composition of the condition, select the best formulation of raw materials, in order to effectively decrease the glass melting temperature, the glass clear, and to achieve specific properties of glass, meet the needs of practical application.OLED Display The sheet molding technology is relevant to dimensional accuracy, surface properties, and the need for further processing of grinding to achieve specific physical and chemical characteristics required rear section contains the glass partition processing, grinding, washing and heat treatment processes.

LCD polarizing film production of the basic method

Currently polarizing film production techniques to extend PVA film technology division, there are dry and wet hair into two categories; PVA membrane staining method to divide, and iodine staining dye-based two categories.

Dry polarizer technology is the production of a PVA film is at a certain temperature and humidity conditions of the steam environment for extended process method, the early use of this process for the purpose of the process is the production efficiency can be improved, compared with width Big PVA film production which is not often broken membranes. However, the limitations of this process is that during the extended PVA film uniformity is limited, so the original film to form a polarizing composite film tension, color uniformity and durability, not easy stability, and therefore the production process in the actual application of the more less. Wet process polarizer technology is the PVA film is a dyed liquid ratio, stretching process method. This process approach is limited in the early PVA film extending in the liquid stability control difficult, so using this process the PVA film processing film is easily broken, and the limited width of the PVA film. But with the improvement of industrial control technology, the limitations of these wet processing technology has been greatly improved, from the late 1990s onwards, Japanese companies have generally adopted Polaroid width 1330 mm TAC film with wet process for polarizing film production. Especially due to large-size TFT-LCD products, massive popularity, to improve the utilization of Polaroid products to 1330 mm width as the basic production polarizer LCD polarizing film has become the basic method of production.
Polaroid production processes in the dyeing method iodine staining and dye staining two processes. Iodine staining refers to the polarizer dyeing, stretching process, the use of iodine and potassium iodide as two isotropic medium the PVA film generates polarized polarizing properties. The advantage of this dyeing method is relatively easy to obtain a high of 99.9% or more than 42% degree of polarization and the polarization properties of a high transmittance. Therefore, the polarization in the early or need high polarizing materials, the high transmission characteristics of polarizing material products are used mostly iodine dyeing processing. But this process is because of the inadequacy low temperature lcd display of the molecular structure of iodine in hot and humid conditions easy damage, so using iodine staining process to produce polarizing film durability is poor, generally only meet the dry temperature: 80 ℃ × 500HR, humidity: 60 ℃ × 90% RH × 500HR use the following conditions apply.
But with the expansion of the scope of LCD products using the polarized product humid working conditions become more demanding requirements has appeared in 100 ℃ and 90% RH polarizer work under conditions of demand for this kind of work conditions require, iodine staining process on the powerless. To meet the requirements of this technique, first by Nippon Kayaku Co., invented a dye polarizing film for production, by a subsidiary of Nippon Kayaku, Japan Bora lines produced high durability of the dye polarizing sheet product. The use of two isotropic dye dyeing Polaroid Polaroid produced products meet the highest dry temperature: 105 ℃ × 500HR, heat:lcd module 90 ℃ × 95% RH × 500HR following working conditions requirements. However, this process for the production of polarizing film products are generally low degree of polarization and the transmission, the polarization degree is generally not more than 90% transmittance of not more than 40%, and expensive.

LCD introductory knowledge

The liquid crystal composition:

lcd module liquid crystal used, generally refers to a mixed liquid crystal, liquid crystal monomer by a variety of chiral agent and mixed together.
The liquid crystal characteristics:
TN liquid crystal generally shorter molecular chains, the characteristic parameter adjustment more difficult, so the difference is more obvious characteristics. STN STN liquid crystal display data through the model to calculate the required length of the liquid crystal molecules, and the optical electrical performance parameters, and chemical synthesis of a variety of molecular chain structure similar to the polar molecular groups with different monomers each formulated into a characteristics similar series of LCD. Different series of the STN liquid crystal molecules tend to have a completely different chains, therefore, different series of the STN liquid crystal manufacturer's instructions unless deploy each other, but not mutually deployment.
Liquid crystal molecules have polar groups and non-polar groups, with polar groups molecules of the liquid crystal monomer mixture mainly determined by the threshold voltage of the liquid crystal parameters, non-polar groups of the liquid crystal monomer molecules The refractive index of the liquid crystal mixture of major decisions and clearing points. Liquid crystal monomers with polar groups and non-polar group-containing monomer in static conditions will occur isomers chromatography homosexual phenomenon.
In order to increase the standby time of the machine itself and enhanced drive capability of the liquid crystal display, TFT LCD Display manufacturers have developed to meet the low voltage and low frequency conditions, low threshold voltage of the liquid crystal used. It has the following features:
Low threshold voltage liquid crystal monomers with polar groups and non-polar group-containing monomer in standing condition isomers chromatography homosexual phenomenon appears shorter time.
More polar group-containing monomer component, also means easier with the liquid crystal molecules, and other polar water-free ions, thereby reducing the resistance of the liquid crystal capacitance, causing increased leakage current and power dissipation large.
When the polarity of the liquid crystal monomer molecular chains in the ultraviolet intensified after the polar molecular groups easily intertwined to form neutral molecules, into a non smectic wrong to state, resulting in the threshold voltage increases, the guide layer anchor given effect is not sensitive to loss of low-voltage drive capability.

Polaroid selection rules

A + regulatory product patches, in principle, the entire selection of original Polaroid, some of the products available TFT LCD Module No optical triangulation material; principle to use original negatives entire polarizer.
A regulation of the surface film, generally used in the original grade whole polarizer, TFT no optical triangulation material or scrap inventory more TFT polarizer; or after the main channel of procurement scrap suppliers TFT polarizer film, negatives Polaroid factory level with the whole or composite negatives.
Class B product patches, try to use less inventory scrap TFT polarizer, scrap pieces, or will no longer be the main channel for purchasing scrap suppliers TFT polarizer; film composite film.
Customers have special requirements, lcd module according to customer requirements special polarizer.
Polaroid use:
Gently, not with a hard object on the surface to push plans.
Can not take place when folded.
To the rank of tablets and scrap pieces to be put into production before the dichroic filter.
Patch, be sure to let the LCD cleaning solution remaining on the surface clean after complete evaporation can paste the polarizer.
Wide temperature Polaroid sure to cut the glue is placed facedown.

Dot matrix character LCD module

It is composed of dot matrix character lcd graphic display and a dedicated row, column drivers, controllers and necessary fittings, structural parts assembled, and can display numbers and Latin characters. The module itself has character dot matrix character generator, display capacity, feature-rich. Usually this kind of module can also be displayed at least 8 a row or 16 l or more lines of characters. The lattice arrangement of this module is 5 × 7,5 × 8, or 5 × 11 array of pixels arranged in a bundle consisting of. Each group is one, each room a little interval between each line has a line spacing, so you can not display graphics.

Usually in the serial display modules control, the drive has been cured good 192 characters character font libraries CGROM, but also has to create a dedicated user-defined character RAM CGRAM, allows users to create 8 5 × 8 dot matrix characters.

Digital measurement module and LCD module timing module

This is a kind of multi-segment type liquid crystal display device and a decoding, driving, counting, A / D conversion function of the IC chip OLED Display Module assembled. As with the integrated circuit used for A / D conversion function, so it can be the analog input signal into the digital display. We know of any physical, or chemical quantity (such as pH, etc.) can be converted to an analog power, so long as a sensor coupled, this module may implement any measure and display the amount of towers, very convenient to use. Metering modules used in integrated circuit models are ICL7106, ICL7116, ICL7126, ICL7136, ICL7135, ICL7129, these integrated features, characteristics determine the metering module's functionality and features. As a measurement products, must be measured according to the provisions identified. Approved by the metrology department attached to a product measurement certificate.
Timing Modules

The liquid crystal Character LCD Module device timing module for timing the oldest and a liquid crystal display device with a timer IC assembly together is a full-featured timer. It did not sound in the finished watch casing, so called timing module. Although the timing module is widely used, but common, standard timekeeping module is difficult to buy in the market, only to go to buy electronic watch manufacturer or order a suitable watch movements, timing modules and counter modules Although similar in appearance, but they are displayed in different ways, the timing module to display a set number two by two set of digits. The figures are each counting modules arranged in a row. As many timing module also has a timer, control functions, so these modules can be assembled into a number of broad power on the device, such as tape recorders, CD players, microwave ovens, rice cookers and other appliances on.

High Brightness LED cut outcrop angle

In fact, rarely heard in the same sentence with "early adopters" and "car market segment," two phrases. Some people might assert that this juxtaposition will become very popular in the oxymoron. However, high-brightness LED to car manufacturers to bring several compelling features, and, although this application is relatively new, but they are the basic characteristics of the majority comes from manufacturing LED indicators - much older than they are and have has been well-proven similar products - the same principle and similar processes.
Lcd display module taillights, turn signal lamps, work lights, brake lights can overcome the inherent incandescent tungsten several major drawbacks. Cars often suffered moderate shock and vibration will shorten the filament life. Similarly, the positive temperature coefficient of resistance of the filament due to inrush current will accelerate the destruction of the lamp. Thermal cycling - brake lights are working on an important feature, often shortened incandescent lamps.
Inrush current incandescent bulbs also makes circuit protection and fault detection task becomes complicated. Car manufacturers have to fuse ratings and fault detection threshold set to the current value large enough to accommodate the surge current amplitude and duration, and the fuse failure does not occur or will not detect false failures.
In contrast, a typical automobile suffering amplitude and frequency range of shock and vibration in the case, LED structure of the filaments is more durable. LGD structure and small size, light weight, thereby reducing the mechanical shock and vibration torque. LED small size, but also the automobile designers to design the lighting was smaller, and which is designed to better meet the overall vehicle design. For example, some cars are not the CHMSL (center high mounted stop lamp) module installed in the rear panel, but to use small LED needed this, this feature is included in the trunk lid.
Taillights lighting and control systems raises several interesting issues, which also appear in the control device and the control device are far apart from each other in other systems. mini lcd module  s essentially a current devices. The presence of electron-hole pairs within the composite organic electroluminescent compounds, and the photons emitted when the composite. Current increases will be a corresponding increase in the composite rate and flux output. Efficiency of this process is not 100% (almost less than 100%), so an increase in current consumption will be increased by 1-h of the device self-heating. Unless the poor working conditions, such as incandescent or LED is generally not as catastrophic failure, but it tends to darken due to aging. Many device designers to terminate the life of the LED light output is defined as the initial value of 50% down to time.
Overcurrent and overtemperature conditions can accelerate the LED end of life, so most of the OEM device manufacturers recommend carefully control LED energy.

LED technology advantages and characteristics

According to some data suggest that attention to environmental protection famous European, LED color printer has accounted for the local market share of 30%, and the upward momentum is very fierce. Even in Canada, emphasis on environmental protection and national intelligence applications, LED color printer sales is more than the traditional laser printers. What is the reason for LED popularity so quickly in developed countries in Europe?
This begins with the advantages of OLED Module technology to analyze. First, both in the way the different optical scanning imaging, the LED color printer does not focus the lens from the rotating polygon mirror and other optical components, the advantages of the LED image that the print speed is more efficient, to continuously improve the resolution, and the overall structure of can be done easier.
Secondly, because LED technology resulting dot small, even can be done with image pixel is completely on the other, it is possible to ensure that the actual resolution is consistent with the theoretical resolution, for clear imaging results.
Again, LED imaging system is not as complicated as laser printing system, long lamp life, the use of more reliable and long-term. Fourth, the laser printer laser head is required to reach the photosensitive drum on the optical data for each row scanning and calibration, the calibration level of assurance of the integrity of the rotation speed of the photosensitive drum has certain limitations. LED printing is the use of multi-point light source, without tedious scanning process can be maintained at a high resolution high-speed printing.
Finally, LED color printer energy saving, energy saving, and the work process produces no ozone, odor, LED technology has a well-deserved green energy characteristics can be generated directly in the bright light under low pressure conditions.
With health and environmental protection, high-speed high-quality and smart highlight the advantages of ease of use, custom lcd display technology is increasingly mature, the sudden emergence as a healthy generation of products in Europe, America, Japan and the market share is climbing, is not surprising. And a new term "healthy office", will more and more people's attention.

Pt particles generated as electrode

Generation phase of the glass material to be melted to better take a direct electric heating method, while using bubble level to improve glass melting and uniformity. Therefore, in liquid phase in the glass has a strong current, taking into account the high temperature performance is generally used bubbler made of Pt, when the(Character LCD Module) insulation is not satisfactory when a bubbler, SnO2 electrode and the electrolyte occurs between the bubbler reaction, thereby resulting in Pt 'melting. "
When do Pt electrode, Pt molten state, so that the impurities in the shape of a microscope seen relatively smooth, with clear glass interface, a larger reflector (but this is less than the former purity of impurities, so there is no reflection before a kind of strong);, and its small size (0.05mm diameter is generally less), just from the appearance easily confused with bubbles, must be carefully identified.
The impurity solution,(serial display modules) we must first check bubbler, furnace insulation; then appropriate to reduce the use of current changes and can also be powered using low gear to some extent alleviate the electrode effect; course, if the use of variable frequency power supply, This occurs when a large number of impurities using high frequency to make a "electrolytic cell" time is very short, the amount is reduced accordingly.

Pt can reduce the harm done

Pt crucible use and protection
Usually a Pt crucible(lcd module), generally with two layers of refractory protective outer layer using a sintered products, the inner refractory filler filling. Sintered products Pt main role is to provide sufficient strength to the crucible, the sintering temperature of such products 1500 ~ 1650 ℃, in the usual optical glass glass melting, fining temperature is far lower than this, so in such products have a very high temperature good high temperature strength; filling material is generally used Al2O3 and high temperature cement (the main component of Al2O3, SiO2 with a small amount of a lithium salt made of cement binder). From the "flash" from the narrative learned that, in a high temperature Pt crucible must be isolated as much as possible the air, so the installation must be good filler wrapped Pt, that during the repair, (Graphic LCD Display)Pt crucible was not good coverage, the filler and a Pt layer of air is formed directly, and the crucible wall as the filler there is a temperature difference between, on one side at a low temperature that a large number of Pt particles condense here.
However, at high filler shrinkage after sintering of Pt difficult to isolate the air, then gas may be considered a method to prevent the reaction.

Touchscreen simple principle analysis

With the use of computers as a growing source of information, the touch screen with its easy to use, durable, fast response, space-saving advantages, making the system more and more designers are using the touch screen does have a feeling of considerable advantage. Appears on the touch screen on the Chinese market so far only a few short years, this new multimedia device has not for many people contact and understanding, including some are planning to use the touch screen system designers, but also regarded as dispensable touchscreen equipment from developed history and popularity of the touch screen of multimedia information industry is in a stage of view, this concept also has a certain universality. In fact, the touch screen is a face-lift to make multimedia information or control devices, it gives multimedia system with a new look, is a very attractive new multimedia interactive devices. System designers have developed and pioneered the use of the touch screen system designers have been clearly know that touch screen computers for a variety of applications is no longer an afterthought, but the essential equipment. It greatly simplifies the use of computers, even for people who know nothing about computers, it still can come in handy, so that the computer show greater charm. Public information on the market to solve computer problems can not be solved. serial oled
The main touch screen three species are: resistive touch screen technology, surface acoustic wave touch screen, capacitive touch screen technology. Each class has its own touch-screen strengths and weaknesses, to understand the kind of touch screen for that occasion, the key lies to know how each type of touch screen technology works and characteristics. Graphic LCD Display

About EMI design in a stacked relationship

Circuit board PCB laminate arrangement is designed on the basis of the overall system. If stacked design flaws that will ultimately affect the machine's EMC performance. Overall laminate designed primarily to follow two rules:
1 Each alignment layer must have an adjacent reference layer (power or ground);
(2) adjacent to a main power and ground to maintain the minimum distance, in order to provide a greater coupling capacitance; listed below from two to ten plates stacked laminates:lcd module
2.1 single-sided and double-sided laminated; For two-layer board, because the board layers less, does not exist laminated issue. Control EMI radiation mainly from the wiring and layout considerations; single plate and double plate electromagnetic compatibility problems are becoming increasingly prominent. The main reason for this phenomenon is the result of the signal loop area is too large, not only produces a strong electromagnetic radiation, but also make the circuit sensitive to external interference. To improve the electromagnetic compatibility of the line, the easiest way is to reduce the area of ​​the loop key signals. Key signal: From the EMC point of view, mainly referring to the key signal generating strong radiation sensitive signal and the signal to the outside world. The signal can produce strong radiation is generally periodic signals such as clock signals or address low. Susceptible to interference signals are those of the analog signal level is low. Single, double plate usually below the low frequency of 10KHz analog design:  at the same level of power traces in radial alignment, and minimize the total length of the line;  take power, ground when close to each other; line at the edge of cloth a key signal ground, this ground should be as close signal lines. Thus forming a small loop area, reducing the differential-mode radiation sensitivity to external interference. When the signal lines plus a ground side, the smallest area to form a loop, the signal via the loop current will certainly, and not some other ground paths.  If the double circuit board, the other side of the circuit board, immediately adjacent to the lower signal line, a ground fabric along the signal line, as more wide line. This loop area formed by multiplying the thickness equal to the circuit board signal line length.lcd graphic display

These aspects of LCD TVs

D-sub15pin
D-sub VGA card is generally the most common computer port, the port uses the asymmetric distribution 15pin connection, which works within the memory image stored in digital format in the RAMDAC after the analog signal into an analog frequency modulation signal and then and then output to a digital display device imaging, so VGA signal at the input (digital display equipment), you do not like the other video signal decoding circuit that go through a conversion matrix. From the foregoing principle known VGA video imaging video transfer process is simple, so the VGA port, has many advantages, such as no separation circuit synthesis crosstalk no wear and tear.
VGA video signal transmission signal to the main computer, VGA port contains an I2C bus, so the host and display devices can be negotiated and automatically determine the best display format, and "plug and play", but the use of hybrid video signal, so after a lot of separate derivative 3RCA or DVI port as such. Many LCD projectors also support the component video adapter to D-sub15pin this video inputs.

-Video
SeparateVideo was also known SUPERVIDEO, but the correct law SeparateVideo which is called discrete video terminal input, it will be called SUPERVIDEO S-Video, with the S-VHS VCR and developed. S-Video is a five-pin S-video port terminals, by the video luminance signal (Y) and chrominance video signal (C) and all the way to the public mask ground components. It separated luminance and chrominance output composite video signal output to avoid the interference between the luminance and chrominance.TFT Lcd Modules
1RCA because it no longer compared to Y / C hybrid transmission and, therefore, no longer need to be bright separation and decoding, and the use of separate transmission channel video equipment largely avoided the signal crosstalk generated image distortion , which greatly improves the clarity of the image, but the S-Video still the two color difference signals (CrCb) mixing all the way chrominance signal C, and then be transmitted within the display apparatus for decoding the Cb and Cr treatment, so much will bring some signal loss and distortion, but quite subtle. S-Video video resolution is higher than 1RCA terminals. S terminal transmitted video signal fidelity higher than the V terminal with S terminal is connected to the video device, its resolution up to 400-500 bar, affecting quality and 3RCA (Component YPbPr) is roughly equal, the transmission distance up to 3-5M.lcd module

1RCA (commonly known as the standard video input terminals / AV terminal)
V terminal is Video (video) terminal short, it is the sound / draw separate video terminal, although the transmission of the video signal and the audio signal through other terminals. The most common is called AV terminal port group, which is composed of three separate RCA plugs (also known as RCA terminal) composition, in which the V port to connect composite video signal, the yellow jack; L port to connect the left channel sound signal is white jack; R port to connect right-channel audio signals to red jack. This mixed video signal without the RF signal that modulation, amplification, detection, demodulation process, signal fidelity is relatively moderate, the use of wire great impact on image quality, resolution, generally up to 350-450 pieces, but because an analog port numbers used in flat panel display devices, and more analog to digital process will lose a lot of S / N ratio, it is generally relatively flat display device numbers is not recommended.

LCD TV, port knowledge

RS-232
Digital display devices appear RS-232 interface is not as video transmission, but the image adjustment device.
RS232C connector: RS-232C standard (protocol) stands for EIA-RS-232C standards, including EIA (ElectronicIndustryAssociation) on behalf of the American Electronics Industry Association, RS (ecommededstandard) represent recommended standard identification number is 232, which provides cable and mechanical , electrical characteristics, functions and signal transmission process. The maximum transmission rate of 20kbps, cable up to 15 meters. RS232C port is used for computer input control signal.OLED Display

DVI (DVI-I, DVI-D, DVI-A)
In some high-end product specifications, some would otherwise have DVI (DigitalVisualInterface) connector, DVI interface is mainly used in conjunction with a digital display output is connected to a computer graphics display the computer's RGB signals. DVI (DigitalVisualInterface) digital display interface, by September 1998, at the Intel Developer Forum, established by the Digital Display Working Group (DigitalDisplayWorkingGroup referred DDWG), developed by digital display interface standard.

DVI digital signal terminals is better than the standard VGA terminal, the entire contents of the digital interface ensures a digital format for transmission to ensure that the host computer to monitor the integrity of data during transmission (no interference signal into), you can get a clearer image. The main purpose is to allow DVI graphics card via digital picture signals transmitted to the computer screen. Because the previous CRT screen uses an analog signal, so the traditional D-sub15pin computer screen connector is taking the analog signal (composite signal) will display the card of the digital picture signal into an analog signal to the computer screen to go.

Since the digital display (LCD projectors, plasma TV, LCDTV and other digital display products) uses pure digital device, then directly through the digital interface input digital signal will be better of course, but through D-sub15pin becomes somewhat unwise ( first digital signal to an analog signal, and then the analog signals into digital displays, and finally through the digital display to digital signals inside again).160x160 lcd

DVI connector, there are three, namely DVI-Digital (DVI-D), DVI-Analog (DVI-A) with DVI-Integrated (DVI-I), DVI-Digital (DVI-D) only supports digital display devices, DVI -Analog (DVI-A) only supports analog display devices, DVI-Integrated (DVI-I) is to support digital display with analog display. There is such a mix of all, because although DVI digital display device to the standards set, but because through digital transmission does not reduce the effect of the screen, along with in order to consider can be converted into analog signals, so will There are DVI-D, DVI-A DVI-I with three joints, which can be compatible with DVI-I DVI-D devices (including cable), but the DVI-D connector is not able to use the DVI-I cable, so you will see a digital display device is DVI-D connector, cable connector is DVI-I, DVI-I graphics card is the connector. And DVI-I adapter also become D-sub15pin.

HDMI
HDMI interface called the next century international digital TV standard "High-DefinitionMultimediaInterface (HDMI)" is on 9 December 2002 by the HDMIFounders (HDMI Forum) Confirm High-DefenitionMultimediaInterfaceSpecificationVersion1.0 specifications. Pioneere more in October 18, 2003 launched the world's first HDMIDVD player DV-S969AVi-N, HDMI interface, is now almost a fever-level representative.

HDMI-1
HDMIFounders (HDMI Forum) by a Hitachi, Matsushita Electric, RoyalPhilips, SiliconImage, Sony, Thomson, Toshiba and other seven international appliance manufacturers components. HDMI to DVI-based but offers higher bandwidth, maximum bandwidth of 5Gbit/Sec, the highest quality HDTV requires only 2Gbit/Sec, there is a great amount set aside for possible future higher standards of digital signal . And joined the HDCP copy protection mechanisms while increasing the digital audio transmission, thus becoming a dedicated multimedia interface. HDMI support 1920 * 1080P high-definition digital signals, and supports DolbyDigital / DTS digital audio formats.

What is a high-brightness LED

High-brightness light-emitting diode (HI-LED) is a semiconductor device that allows current to flow in one direction. It is the combination of two semiconductor material is formed into the structure of the PN. High brightness LED and the difference between the standard LED is their output power. Traditional LED output power is generally limited to less than 50 mW, while the high brightness LED up to 1-5 watts.lcd module

In the forward voltage (VF) exceeds the threshold voltage of the internal front, HI-LED has almost no forward current (IF) flows. If VF increased further, the curve will be linear slope sudden rapid rise, forming a shape of the knee of the curve.
LED output intensity is proportional to the forward current, so that if not properly controlled IF output brightness changes may be unacceptable. In addition, if more than the maximum specified by the manufacturer IF restrictions may seriously shorten LED life.

High brightness LED should be controlled by an electronic driver, the electronic driver's main function is to form a constant current source. Using the techniques described later in this article, these circuits may provide luminosity control, in some cases, can also compensate for changes in temperature.

To ensure color consistency provided by the system, HI-LED manufacturers recommend a constant nominal current pulse output of the LED brightness adjustment.122x32 lcd module