tft display in cars quotation
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The traditional mechanical instrument lacks the ability to satisfy the market with characters of favorable compatibility, easy upgrading, and fashion. Thus the design of a TFT-LCD (thin film transistor-liquid crystal display) based automobile instrument is carried out. With a 7-inch TFT-LCD and the 32-bit microcontroller MB91F599, the instrument could process various information generated by other electronic control units (ECUs) of a vehicle and display valuable driving parameters on the 7-inch TFT-LCD. The function of aided parking is also provided by the instrument. Basic principles to be obeyed in circuits designing under on-board environment are first pointed out. Then the paper analyzes the signals processed in the automobile
instrument and gives an introduction to the sampling circuits and interfaces related to these signals. Following this is the functional categorizing of the circuit modules, such as video buffer circuit, CAN bus interface circuit, and TFT-LCD drive circuit. Additionally, the external EEPROM stores information of the vehicle for history data query, and the external FLASH enables the display of high quality figures. On the whole, the accomplished automobile instrument meets the requirements of automobile instrument markets with its characters of low cost, favorable compatibility, friendly interfaces, and easy upgrading.
As an essential human-machine interface, the automobile instrument provides the drivers with important information of the vehicle. It is supposed to process various information generated by other ECUs and display important driving parameters in time, only in which way can driving safety be secured. However, the traditional mechanical automobile instrument is incompetent to provide all important information of the vehicle. Besides, the traditional instrument meets great challenge with the development of microelectronic technology, advanced materials, and the transformation of drivers’ aesthetics [1, 2]. Moreover, the parking of the vehicle is also a problem puzzling many new drivers. Given this, traditional instruments should be upgraded in terms of driving safety, cost, and fashion.
The digital instrument has functions of vehicle information displaying, chord alarming, rear video aided parking, LED indicating, step-motor based pointing, and data storage. The instrument adopts dedicated microcontroller MB91F599, a 7-inch LCD, and two step-motors to substitute for the traditional instrument. All the information generated by other ECUs can be acquired via not only the sample circuits but also the CAN bus.
The instrument provides interfaces for different types of signals and the CAN bus. All types of signals (such as square wave signal, switching signal, resistance signal, analog voltage signal, etc.) coming from other ECUs can be acquired either from different types of sampling circuits or from the CAN bus. This makes it suitable for both the outdated application where the information from other ECUs can only be acquired via the sampling circuits and the modern application where the information from other ECUs are transmitted via the CAN bus.
The CAN bus interface and the 7-inch TFT-LCD make it more convenient to upgrade the instrument without changing the hardware. If the software needs to be upgraded, we need not bother to take the instrument down and program the MCU. Instead, we can upgrade the instrument via the vehicle’s CAN network without taking the instrument down, which makes the upgrading more convenient. Most of the information from other ECUs can be transmitted via the CAN bus; so, we do not have to change the hardware circuits if some of the ECUs’ signals are changed in different applications. Besides, since most of the driving parameters are displayed on the TFT-LCD, and the graphical user interface can be designed with great flexibility by programming, only the software needs to be revised to meet different requirements of what kind of driving parameters to display and so forth. These characters, together with the reserved interfaces, enhance the instrument’s compatibility in different applications.
It is a trend to incorporate the instrument into the vehicle information system via the CAN bus. The CAN bus interface gives the instrument access to the vehicle CAN network which enables easier fault diagnosing [3, 4] and information sharing. The fault diagnosing could be realized by accomplishing the fault diagnosing protocol above the low-speed CAN bus.
On the one hand, there are some automobile instruments which adopt 8-bit MCUs or 16-bit MCUs which have limited peripherals, so it is difficult for them to meet some requirements such as rearview video and high real-time data processing performance. And many extra components are needed if the designer wants to accomplish some functions such as video input. On the other hand, there are some advanced automobile instruments which adopt high performance MCUs (such as i.MX 53, MPC5121e, and MPC5123) and run Linux on them. They even use larger TFT-LCDs (such as the 12.3-inch TFT-LCD with a resolution of 1280 × 480 pixels) to display driving parameters. These automobile instruments show higher performances than the instrument in this paper. However, they are more expensive than this automobile. This instrument is able to provide almost all the functions of the advanced automobile instrument with a lower cost.
The instrument receives signals from other ECUs via the sampling circuits or the CAN bus interface. It can also receive commands from the driver via the button interface. The signals are then processed by the MCU, after which the MCU may send the vehicle information to the LCD or light the LEDs and so forth, according to the results. Therefore, the automobile instrument can be viewed as a carrier of the information flow. And the design of the system can be viewed from two aspects: the hardware system and the information flow based on it.
From the aspect of hardware system components, the system consists of the MCU MB91F599 and other functional circuits such as sampling circuits and video buffer circuits, as shown in Figure 2.
In order to guarantee the performance of the automobile instrument under specific on-board environment and to save the cost of the design, several basic principles must be considered.3.1.1. Chip Package
SMD components are the first choice due to space limitations of the instrument cluster. And the actual power of these components must be no more than 30% of the rated power.3.1.2. Overvoltage Protection
Overvoltage protection circuits should be placed at the interfaces of power supply and important signals (such as the CAN bus interface) in case of voltage overshoots.3.1.3. Generality
Reserved interfaces should be taken into consideration to shorten the development cycle of subsequent similar instruments and optimize the instrument for general use.3.1.4. Inventories
The automobile instrument receives and processes information from other ECUs such as the tachometer, the speedometer, the cooling water temperature gauge, the oil pressure gauge, and the fuel gauge. The signals coming from these ECUs are of different types, according to which different kinds of sampling circuits and interfaces should be designed. Accordingly, a classification of the input signals is first carried out, as shown in Table 1.
The microcontroller is essential to the performance of the instrument cluster. Therefore, the microcontroller that suits the system should have rich peripherals to reduce extra components, thus saving the space of the cluster and enhancing the stability of the system. Meanwhile, the operating frequency should be high and the memory size should be large for the demand of speed and accuracy in real-time processing. Besides, various operation modes are needed to lower down the power consumption.
Respecting the above mentioned factors, we finally chose the MB91F599 produced by Fujitsu as the microcontroller. The MB91F599 is particularly well-suited for use in automotive instrument clusters using color displays to generate flexible driver interfaces. It integrates a high performance FR81S CPU core which offers the highest CPU performance level in the industry. Besides, it has a graphics display controller with strong sprite functionality, rendering engine, and external video capture capabilities. These greatly reduce the need for extra components and enhance the stability of the system. The rendering engine can operate in combination with the video capture to enable image manipulation. Overlaid graphics such as needles or parking guidelines can be rendered in conjunction with captured video, which helps to accomplish the aided parking. What is more, multiple built-in regulators and a flexible standby mode enable the MB91F599 to operate with low power consumption.
Square wave signal is the signal that comes from the tachometer. The engine speed, the velocity of the vehicle, and the mileage are proportional to the frequency of the square wave signal. However, the square wave is not “standard” because it is often corrupted by interferences. Besides, the peak voltage of the square wave is +12 V while the I/O voltage of the microcontroller is . The main task for the circuits is to remove the interferences and convert the +12 V voltage to . As shown in Figure 3, the square wave signal is input from node ②; node ① is connected to one pin of the microcontroller.
After the preprocessing of the square wave, the microcontroller detects the positive edge of the “standard” square wave and calculates its frequency. The engine speed, the velocity of the vehicle, and the mileage can be calculated based on the frequency.
where is the engine speed, is the frequency of the square wave, and is the number of pulses generated by the tachometer in every circle of the wheel.
where is the velocity of the vehicle, is the frequency of the square wave, is the diameter of the wheel, is the reduction ratio of the main reducer, and is the number of pulses generated by the tachometer in every circle of the wheel.
The switching signal acts as a trigger signal to trigger some events such as lighting up the backlight and waking up the MCU. It can be categorized into active high and active low according to the ECUs that generate it. Figure 4 offers a complete picture of the sampling circuit of active high signal. The switching signal is input from node ②; node ① is connected to one pin of the microcontroller. Diode clamps the peak voltage of the switching signal (usually +12 V) to the standard I/O voltage of the microcontroller () after resistive subdivision. The sampling circuit of active low signal is similar to Figure 4.
The resistance signal is generated by the fuel gauge and the air volume gauge. As shown in Figure 5, the resistance signal is input from node ①; node ② is connected to one pin of the microcontroller. , , , and have the same value of and they form a series-parallel network to cut down the power consumption of each resistor to one forth that of a one-resistor solution.
The analog voltage signal reflects the battery voltage and the air pressure. The corresponding circuit adopts the resistive subdivision so as to adjust the ratio of the resistors for putting voltage of the signal below the microcontroller’s maximum I/O voltage. The value of the resistors should be a little larger to lower down the static power consumption of the resistors. It is unnecessary to go into detail of the circuit.
The rearview video contributes a lot to vehicle backing and parking. The signal coming from the rear camera must be regulated before being processed by the microcontroller. The rear camera outputs NTSC video. The MB91F599 integrates a video decoder which supports NTSC/PAL video input, which makes the design of the regulatory circuit simple.
Figure 6 shows RGB with sync in NTSC format. The RGB varies in a positive direction from the “black level” (0 V) to 700 mV. Meanwhile, a sync waveform of −300 mV is attached to the video signal. Since the output video signal of the camera is AC-coupled, a clamp circuit is needed to clamp the RGB and sync to a reference voltage and leave the others to vary. If not clamped, the bias voltage will vary with video content and the brightness information will be lost [5].
The video buffer circuit consists of a clamping circuit (, , ) and an emitter follower (, , ), as shown in Figure 7. Node ① is connected to the NTSC input pin of the microcontroller; node ② is connected to the clamp level output pin of the microcontroller; node ③ is connected to the camera’s signal output. is the coupling capacitor; is the matching resistor to realize the 75 Ω back termination.
Here, the sync signal is not present, so the clamp level is controlled by the clamp level output pin of the microcontroller, which is called “keyed clamp” [5]. The graphics display controller of the microcontroller let the clamp level output occur in coincidence with the sync pulse; that is, the clamp level output occurs during the sync tip in Figure 6, thus we get the “sync tip clamp” [5].
Since the FLASH size of the microcontroller is only 1 MB which is limited for the storage of pictures displayed on the LCD, external FLASH is needed to store different kinds of meaningful pictures such as the background of the dial. Two S29GL256N chips with a memory capacity of 256 Mb are chosen for picture data storage for their high performance and low power consumption. The application circuits of the chips are provided in their datasheets, so it is unnecessary to go into the details of them here.
Controller Area Network (CAN) is widely deployed in automobile, industry, and aerospace domains. As a major trend of the technological development of in the automation industry, CAN is now reputed as a local area network in automation [6]. Its low cost and ability to integrate with most microcontroller silicon families have made it a standard for automobile applications [7–9].
The ECUs of engine control, full active suspension control [10, 11], airbag control, traction control, and so forth are nodes of the controller area network and can be controlled via CAN bus in time. Thus a networked control system (NCS) is formed via CAN bus and some results in [12–15] may be useful in the controller design of the communication system. The communication system can be categorized by the requirements of real-time response of each node. The nodes requiring good performance in real-time response and reliability should be designed into high-speed communication network, while others should be designed into low-speed communication network [16].
Full active suspension control, airbag control, traction control, and so forth are incorporated into high-speed communication system since their requirements of real-time response and reliability are critical. Because of less critical requirements, on-board fault diagnosing [17, 18], doors control, windows control, and so forth are incorporated into low-speed communication system. The transmitting rate of the high-speed CAN bus is 500 kbps while that of the low-speed one is 250 kbps. The two kinds of communication systems are connected via a gateway which enables real-time sharing of data. And the data transmitting of the high-speed CAN bus has a higher priority over the low speed CAN bus when a collision occurs.
For this design, only the CAN transceiver and its auxiliary circuit are needed since the MB91F599 is integrated with two CAN controllers, which are connected to the high-speed and low-speed CAN bus, respectively. TJA1040 is chosen as the CAN transceiver for its low consumption in standby mode. Besides, it can also be woken up via CAN bus, which is required by some automobile instruments. Detailed circuit is provided in the datasheet of TJA1040, so the repetitious details need not be given here. Note that for high-speed CAN, both ends of the pair of signal wires must be terminated. ISO 11898 requires a cable with a nominal impedance of 120 Ω [19]; therefore, 120 Ω resistors are needed for termination. Here, only the devices on the ends of the cable need 120 Ω termination resistors.
The 7-inch TFT-LCD has a resolution of pixels and supports the 24-bit for three RGB colors. The interface of the 60-pin TFT-LCD can be categorized into data interface, control interface, bias voltage interface, and gamma correction interface.
The data interface supports the parallel data transmitting of 18-bit (6 bits per channel) for three RGB colors. Thus, a range of colors can be generated. The control interface consists of a “horizontal synchronization” which indicates the start of every scan line, a “vertical synchronization” which indicates the start of a new field, and a “pixel clock.” This part is controlled by the graphics display controller which is integrated in the MB91F599. We just need to connect the pins of the LCD to those of the microcontroller correspondingly.
Bias voltages are used to drive the liquid crystal molecules in an alternating form. The compact LCD bias IC TPS65150 provides all bias voltages required by the 7-inch TFT-LCD. The detailed circuit is also provided in the datasheet of TPS65150.
The greatest effect of gamma on the representations of colors is a change in overall brightness. Almost every LCD monitor has an intensity to voltage response curve which is not a linear function. So if the LCD receives a message that a certain pixel should have certain intensity, it will actually display a pixel which has intensity not equal to the certain one. Then the brightness of the picture will be affected. Therefore, gamma correction is needed. Several approaches to gamma correction are discussed in [20–22]. For this specific 7-inch LCD, only the producer knows the relationship between the voltage sent to the LCD and the intensity it produces. The signal can be corrected according to the datasheet of the LCD before it gets to the monitor. According to the datasheet, ten gamma correction voltages are needed. These voltages can be got from a resistive subdivision circuit.
The vehicle electric power system is mainly composed of a generator and a battery [23]. The power voltage of a car is +12 V while that of a bus is +24 V. The power supply of the automobile instrument alternates between the generator and the battery. The generator powers the automobile instrument and charges the battery when working. Note that the battery does not power the instrument when the generator is on. If the generator is not working, the instrument is powered by the battery. Figure 9 shows how the power supply alternates. Node ① is connected to the battery; node ② is connected to the generator; node ③ is connected to other circuits. When the generator is on, and are turned off, which prevents node ③ from getting power from the battery. Then node ③ gets power from the generator via other routes (not shown in the figure). When the generator is off, and are turned on, so node ③ gets power from the battery.
For this instrument, the LED indicators, the backlight, and the chord alarm need to be supplied with a voltage of +12 V; the CAN transceiver, the EEPROM, and the buttons need to be supplied with a voltage of +5 V; the video buffer circuit, the external FLASH, and the data interface of the LCD need to be supplied with a voltage of +3.3 V. Besides, the microcontroller needs to be supplied with voltages of +5 V and +3.3 V simultaneously. Figure 8 offers a detailed block diagram of the power supply for the automobile instrument.
The main task for the program is to calculate the driving parameters of the vehicle and display them on the TFT-LCD. The calculation is triggered by the input signals via the sampling circuits or the CAN bus. The main program flow chart of the system is shown in Figure 10.
The design scheme of a TFT-LCD based automobile instrument is carried out form aspects of both the hardware and the main program flow chart. The MB91F599 simplifies the peripheral circuits with its rich on-chip resources and shows high performance in real-time data processing. The automobile instrument is capable of displaying the velocity of the vehicle, the engine speed, the cooling water temperature, the oil pressure, the fuel volume, the air pressure, and other information on the TFT-LCD, which contributes a lot to driving safety and satisfies drivers’ aesthetics. Besides, the rearview video makes the parking and backing easier and safer for the driver. Moreover, the CAN bus interface and TFT-LCD make it easier for the upgrading of the instrument without changing the hardware, thus saving the cost.
The authors acknowledge the support of China Postdoctoral Science Foundation Grants no. 2012M520738 and no. 2012M520739, Heilongjiang Postdoctoral Fund no. LBH-Z12092, and the support of the Polish-Norwegian Research Programme in the frame of Project Contract no. Pol-Nor/200957/47/2013.
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Expectations continue to rise in the automotive industry, and automotive displays are at the center of the action. There is a stronger demand for greater convenience, safety, and comfort in today’s cars. Many consumers expect more than monochrome visuals from the driver’s seat; the crisp and clear graphics found in a TFT LCD display offers an excellent way to satisfy this need.
Drivers today are not content with using their vehicles to get from Point A to Point B anymore. That’s why modern passenger cars now have numerous cutting-edge capabilities that enhance the daily lives of car owners and passengers, such as on-road entertainment, appointment scheduling, and other connected services. A TFT LCD module is a great option for smart displays that accomplish these activities.
The current trend among OEMs is to roll out economic vehicle variants with advanced display applications. Of course, the cost of equipping a car with the latest smart displays will have quite an impact on its overall price. TFT module displays can deliver practical solutions to various automotive display applications depending on the needs of the project.
In as little as two decades ago, you’ll find instrument clusters, infotainment units, information displays, and other automotive electronics components equipped with monochrome LCD panels in their basic form. However, technological and electronic advancements have allowed for display applications to integrate more and more vehicle functions.
The past years have seen advanced display applications featuring TFT-LCD and LCD display panels. LCD panels are particularly effective for the instrument cluster, the basic center stack touchscreen, and the rear seat entertainment touchscreen. TFT LCD displays, meanwhile, were preferred for more advanced applications thanks to their appeal and visual quality. Both LCD and TFT-LCD technologies satisfy strict automotive application requirements.
Automotive display applications are home to advanced functions. Therefore, display panel manufacturers must meet the stringent requirements for durability and ideal temperature in automotive applications.
Other advanced technologies, such as AMOLED and LED, may not be well-suited for automotive display applications because typically, these options are not able to withstand the high temperatures involved in automotive applications. They also tend to be not as durable as TFT-LCD and LCD display panels for vehicles.
While LED and AMOLED technologies do offer amazing display aesthetics, TFT-LCD and LCD displays remain some of the best options for the automotive industry.
Smart displays are not the only applications that benefit from TFT-LCD and LCD technologies. Others like speedometers, satellite navigation, tachometers, backup cameras, gauge clusters, radio controls and dash controls are also undergoing dramatic innovations.
Microtips Technology USA is a leading global manufacturer of TFT-LCD and LCD displays for automotive applications. Some available key features of our displays include:
We also offer comprehensive turnkey solutions, and we can assist with all stages of your project development, including design. For the best TFT-LCD, Touch Panels, OLED LCD, Monochrome, and Custom Segment displays, contact Microtips Technology USA today!
Microtips Technology provides displays in many different industries around the world. Because of this, we have become familiar with certain requirements that are necessary in these different markets. Our team can guide and advise on what displays will be best for your particular application. We can also tune any of our standard displays to work better for your environment. We offer anything from wide-temperature fluid for automotive applications to display module ruggedization for harsh or humid environments to tuning our capacitive touchscreen with glove and stylus support in mind.
A thin-film-transistor liquid-crystal display (TFT LCD) is a variant of a liquid-crystal display that uses thin-film-transistor technologyactive matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven (i.e. with segments directly connected to electronics outside the LCD) LCDs with a few segments.
In February 1957, John Wallmark of RCA filed a patent for a thin film MOSFET. Paul K. Weimer, also of RCA implemented Wallmark"s ideas and developed the thin-film transistor (TFT) in 1962, a type of MOSFET distinct from the standard bulk MOSFET. It was made with thin films of cadmium selenide and cadmium sulfide. The idea of a TFT-based liquid-crystal display (LCD) was conceived by Bernard Lechner of RCA Laboratories in 1968. In 1971, Lechner, F. J. Marlowe, E. O. Nester and J. Tults demonstrated a 2-by-18 matrix display driven by a hybrid circuit using the dynamic scattering mode of LCDs.T. Peter Brody, J. A. Asars and G. D. Dixon at Westinghouse Research Laboratories developed a CdSe (cadmium selenide) TFT, which they used to demonstrate the first CdSe thin-film-transistor liquid-crystal display (TFT LCD).active-matrix liquid-crystal display (AM LCD) using CdSe TFTs in 1974, and then Brody coined the term "active matrix" in 1975.high-resolution and high-quality electronic visual display devices use TFT-based active matrix displays.
The liquid crystal displays used in calculators and other devices with similarly simple displays have direct-driven image elements, and therefore a voltage can be easily applied across just one segment of these types of displays without interfering with the other segments. This would be impractical for a large display, because it would have a large number of (color) picture elements (pixels), and thus it would require millions of connections, both top and bottom for each one of the three colors (red, green and blue) of every pixel. To avoid this issue, the pixels are addressed in rows and columns, reducing the connection count from millions down to thousands. The column and row wires attach to transistor switches, one for each pixel. The one-way current passing characteristic of the transistor prevents the charge that is being applied to each pixel from being drained between refreshes to a display"s image. Each pixel is a small capacitor with a layer of insulating liquid crystal sandwiched between transparent conductive ITO layers.
The circuit layout process of a TFT-LCD is very similar to that of semiconductor products. However, rather than fabricating the transistors from silicon, that is formed into a crystalline silicon wafer, they are made from a thin film of amorphous silicon that is deposited on a glass panel. The silicon layer for TFT-LCDs is typically deposited using the PECVD process.
Polycrystalline silicon is sometimes used in displays requiring higher TFT performance. Examples include small high-resolution displays such as those found in projectors or viewfinders. Amorphous silicon-based TFTs are by far the most common, due to their lower production cost, whereas polycrystalline silicon TFTs are more costly and much more difficult to produce.
The twisted nematic display is one of the oldest and frequently cheapest kind of LCD display technologies available. TN displays benefit from fast pixel response times and less smearing than other LCD display technology, but suffer from poor color reproduction and limited viewing angles, especially in the vertical direction. Colors will shift, potentially to the point of completely inverting, when viewed at an angle that is not perpendicular to the display. Modern, high end consumer products have developed methods to overcome the technology"s shortcomings, such as RTC (Response Time Compensation / Overdrive) technologies. Modern TN displays can look significantly better than older TN displays from decades earlier, but overall TN has inferior viewing angles and poor color in comparison to other technology.
Most TN panels can represent colors using only six bits per RGB channel, or 18 bit in total, and are unable to display the 16.7 million color shades (24-bit truecolor) that are available using 24-bit color. Instead, these panels display interpolated 24-bit color using a dithering method that combines adjacent pixels to simulate the desired shade. They can also use a form of temporal dithering called Frame Rate Control (FRC), which cycles between different shades with each new frame to simulate an intermediate shade. Such 18 bit panels with dithering are sometimes advertised as having "16.2 million colors". These color simulation methods are noticeable to many people and highly bothersome to some.gamut (often referred to as a percentage of the NTSC 1953 color gamut) are also due to backlighting technology. It is not uncommon for older displays to range from 10% to 26% of the NTSC color gamut, whereas other kind of displays, utilizing more complicated CCFL or LED phosphor formulations or RGB LED backlights, may extend past 100% of the NTSC color gamut, a difference quite perceivable by the human eye.
The transmittance of a pixel of an LCD panel typically does not change linearly with the applied voltage,sRGB standard for computer monitors requires a specific nonlinear dependence of the amount of emitted light as a function of the RGB value.
In-plane switching was developed by Hitachi Ltd. in 1996 to improve on the poor viewing angle and the poor color reproduction of TN panels at that time.
Initial iterations of IPS technology were characterised by slow response time and a low contrast ratio but later revisions have made marked improvements to these shortcomings. Because of its wide viewing angle and accurate color reproduction (with almost no off-angle color shift), IPS is widely employed in high-end monitors aimed at professional graphic artists, although with the recent fall in price it has been seen in the mainstream market as well. IPS technology was sold to Panasonic by Hitachi.
Most panels also support true 8-bit per channel color. These improvements came at the cost of a higher response time, initially about 50 ms. IPS panels were also extremely expensive.
IPS has since been superseded by S-IPS (Super-IPS, Hitachi Ltd. in 1998), which has all the benefits of IPS technology with the addition of improved pixel refresh timing.
In 2004, Hydis Technologies Co., Ltd licensed its AFFS patent to Japan"s Hitachi Displays. Hitachi is using AFFS to manufacture high end panels in their product line. In 2006, Hydis also licensed its AFFS to Sanyo Epson Imaging Devices Corporation.
It achieved pixel response which was fast for its time, wide viewing angles, and high contrast at the cost of brightness and color reproduction.Response Time Compensation) technologies.
Less expensive PVA panels often use dithering and FRC, whereas super-PVA (S-PVA) panels all use at least 8 bits per color component and do not use color simulation methods.BRAVIA LCD TVs offer 10-bit and xvYCC color support, for example, the Bravia X4500 series. S-PVA also offers fast response times using modern RTC technologies.
When the field is on, the liquid crystal molecules start to tilt towards the center of the sub-pixels because of the electric field; as a result, a continuous pinwheel alignment (CPA) is formed; the azimuthal angle rotates 360 degrees continuously resulting in an excellent viewing angle. The ASV mode is also called CPA mode.
A technology developed by Samsung is Super PLS, which bears similarities to IPS panels, has wider viewing angles, better image quality, increased brightness, and lower production costs. PLS technology debuted in the PC display market with the release of the Samsung S27A850 and S24A850 monitors in September 2011.
TFT dual-transistor pixel or cell technology is a reflective-display technology for use in very-low-power-consumption applications such as electronic shelf labels (ESL), digital watches, or metering. DTP involves adding a secondary transistor gate in the single TFT cell to maintain the display of a pixel during a period of 1s without loss of image or without degrading the TFT transistors over time. By slowing the refresh rate of the standard frequency from 60 Hz to 1 Hz, DTP claims to increase the power efficiency by multiple orders of magnitude.
Due to the very high cost of building TFT factories, there are few major OEM panel vendors for large display panels. The glass panel suppliers are as follows:
External consumer display devices like a TFT LCD feature one or more analog VGA, DVI, HDMI, or DisplayPort interface, with many featuring a selection of these interfaces. Inside external display devices there is a controller board that will convert the video signal using color mapping and image scaling usually employing the discrete cosine transform (DCT) in order to convert any video source like CVBS, VGA, DVI, HDMI, etc. into digital RGB at the native resolution of the display panel. In a laptop the graphics chip will directly produce a signal suitable for connection to the built-in TFT display. A control mechanism for the backlight is usually included on the same controller board.
The low level interface of STN, DSTN, or TFT display panels use either single ended TTL 5 V signal for older displays or TTL 3.3 V for slightly newer displays that transmits the pixel clock, horizontal sync, vertical sync, digital red, digital green, digital blue in parallel. Some models (for example the AT070TN92) also feature input/display enable, horizontal scan direction and vertical scan direction signals.
New and large (>15") TFT displays often use LVDS signaling that transmits the same contents as the parallel interface (Hsync, Vsync, RGB) but will put control and RGB bits into a number of serial transmission lines synchronized to a clock whose rate is equal to the pixel rate. LVDS transmits seven bits per clock per data line, with six bits being data and one bit used to signal if the other six bits need to be inverted in order to maintain DC balance. Low-cost TFT displays often have three data lines and therefore only directly support 18 bits per pixel. Upscale displays have four or five data lines to support 24 bits per pixel (truecolor) or 30 bits per pixel respectively. Panel manufacturers are slowly replacing LVDS with Internal DisplayPort and Embedded DisplayPort, which allow sixfold reduction of the number of differential pairs.
Backlight intensity is usually controlled by varying a few volts DC, or generating a PWM signal, or adjusting a potentiometer or simply fixed. This in turn controls a high-voltage (1.3 kV) DC-AC inverter or a matrix of LEDs. The method to control the intensity of LED is to pulse them with PWM which can be source of harmonic flicker.
The bare display panel will only accept a digital video signal at the resolution determined by the panel pixel matrix designed at manufacture. Some screen panels will ignore the LSB bits of the color information to present a consistent interface (8 bit -> 6 bit/color x3).
With analogue signals like VGA, the display controller also needs to perform a high speed analog to digital conversion. With digital input signals like DVI or HDMI some simple reordering of the bits is needed before feeding it to the rescaler if the input resolution doesn"t match the display panel resolution.
The statements are applicable to Merck KGaA as well as its competitors JNC Corporation (formerly Chisso Corporation) and DIC (formerly Dainippon Ink & Chemicals). All three manufacturers have agreed not to introduce any acutely toxic or mutagenic liquid crystals to the market. They cover more than 90 percent of the global liquid crystal market. The remaining market share of liquid crystals, produced primarily in China, consists of older, patent-free substances from the three leading world producers and have already been tested for toxicity by them. As a result, they can also be considered non-toxic.
Kawamoto, H. (2012). "The Inventors of TFT Active-Matrix LCD Receive the 2011 IEEE Nishizawa Medal". Journal of Display Technology. 8 (1): 3–4. Bibcode:2012JDisT...8....3K. doi:10.1109/JDT.2011.2177740. ISSN 1551-319X.
Brody, T. Peter; Asars, J. A.; Dixon, G. D. (November 1973). "A 6 × 6 inch 20 lines-per-inch liquid-crystal display panel". 20 (11): 995–1001. Bibcode:1973ITED...20..995B. doi:10.1109/T-ED.1973.17780. ISSN 0018-9383.
Richard Ahrons (2012). "Industrial Research in Microcircuitry at RCA: The Early Years, 1953–1963". 12 (1). IEEE Annals of the History of Computing: 60–73. Cite journal requires |journal= (help)
K. H. Lee; H. Y. Kim; K. H. Park; S. J. Jang; I. C. Park & J. Y. Lee (June 2006). "A Novel Outdoor Readability of Portable TFT-LCD with AFFS Technology". SID Symposium Digest of Technical Papers. AIP. 37 (1): 1079–82. doi:10.1889/1.2433159. S2CID 129569963.
Kim, Sae-Bom; Kim, Woong-Ki; Chounlamany, Vanseng; Seo, Jaehwan; Yoo, Jisu; Jo, Hun-Je; Jung, Jinho (15 August 2012). "Identification of multi-level toxicity of liquid crystal display wastewater toward Daphnia magna and Moina macrocopa". Journal of Hazardous Materials. Seoul, Korea; Laos, Lao. 227–228: 327–333. doi:10.1016/j.jhazmat.2012.05.059. PMID 22677053.
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