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Panox Display provides free connectors for clients who purchase more than five products from us. Our product range includes connectors from Molex, Kyocera, AXE, AXG, JAE, Hiros, and more.
Panox Display provides a customized cover glass/touch panel service. We supply cover glass from Gorilla, AGC, and Panda, which all have excellent optical performance. We also supply driver ICs from Goodix and Focaltech.
If your applications are directly connected to a PC, a cellphone, or Raspberry Pi, and you have enough space to insert a board to input video, Panox Display can provide customized Controller/Driver boards with input connections for VGA, HDMI, DVI, DP, Type-C video input, MIPI, RGB, LVDS, and eDP.
The functions of our boards include, but are not limited to, adjustment of brightness, sound output, touch interface, extra data transmission, and gyroscope.
If you want to buy a new monitor, you might wonder what kind of display technologies I should choose. In today’s market, there are two main types of computer monitors: TFT LCD monitors & IPS monitors.
The word TFT means Thin Film Transistor. It is the technology that is used in LCD displays. We have additional resources if you would like to learn more about what is a TFT Display. This type of LCDs is also categorically referred to as an active-matrix LCD.
These LCDs can hold back some pixels while using other pixels so the LCD screen will be using a very minimum amount of energy to function (to modify the liquid crystal molecules between two electrodes). TFT LCDs have capacitors and transistors. These two elements play a key part in ensuring that the TFT display monitor functions by using a very small amount of energy while still generating vibrant, consistent images.
Industry nomenclature: TFT LCD panels or TFT screens can also be referred to as TN (Twisted Nematic) Type TFT displays or TN panels, or TN screen technology.
IPS (in-plane-switching) technology is like an improvement on the traditional TFT LCD display module in the sense that it has the same basic structure, but has more enhanced features and more widespread usability.
These LCD screens offer vibrant color, high contrast, and clear images at wide viewing angles. At a premium price. This technology is often used in high definition screens such as in gaming or entertainment.
Both TFT display and IPS display are active-matrix displays, neither can’t emit light on their own like OLED displays and have to be used with a back-light of white bright light to generate the picture. Newer panels utilize LED backlight (light-emitting diodes) to generate their light hence utilizing less power and requiring less depth by design. Neither TFT display nor IPS display can produce color, there is a layer of RGB (red, green, blue) color filter in each LCD pixels to produce the color consumers see. If you use a magnifier to inspect your monitor, you will see RGB color in each pixel. With an on/off switch and different level of brightness RGB, we can get many colors.
Wider viewing angles are not always welcome or needed. Image you work on the airplane. The person sitting next to you always looking at your screen, it can be very uncomfortable. There are more expensive technologies to narrow the viewing angle on purpose to protect the privacy.
Winner. IPS TFT screens have around 0.3 milliseconds response time while TN TFT screens responds around 10 milliseconds which makes the latter unsuitable for gaming
Winner. the images that IPS displays create are much more pristine and original than that of the TFT screen. IPS displays do this by making the pixels function in a parallel way. Because of such placing, the pixels can reflect light in a better way, and because of that, you get a better image within the display.
As the display screen made with IPS technology is mostly wide-set, it ensures that the aspect ratio of the screen would be wider. This ensures better visibility and a more realistic viewing experience with a stable effect.
Winner. While the TFT LCD has around 15% more power consumption vs IPS LCD, IPS has a lower transmittance which forces IPS displays to consume more power via backlights. TFT LCD helps battery life.
Normally, high-end products, such as Apple Mac computer monitors and Samsung mobile phones, generally use IPS panels. Some high-end TV and mobile phones even use AMOLED (Active Matrix Organic Light Emitting Diodes) displays. This cutting edge technology provides even better color reproduction, clear image quality, better color gamut, less power consumption when compared to LCD technology.
What you need to choose is AMOLED for your TV and mobile phones instead of PMOLED. If you have budget leftover, you can also add touch screen functionality as most of the touch nowadays uses PCAP (Projective Capacitive) touch panel.
This kind of touch technology was first introduced by Steve Jobs in the first-generation iPhone. Of course, a TFT LCD display can always meet the basic needs at the most efficient price. An IPS display can make your monitor standing out.
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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This paper presents a novel 2-D-3-D switchable gate driver circuit for active-matrix liquid crystal displays (AMLCDs) applications using the hydrogenated amorphous silicon (a-Si:H) technology. While consisting of 12 thin-film transistors (TFTs), the proposed gate driver circuit includes a pull-up circuit, two alternative circuits, and a key pull-down circuit. To provide a stable output waveform for switching between the 2-D and 3-D modes in AMLCD panel, the proposed circuit can improve the…Expand
Liquid Crystal Pixels are transmission type pixels with a backlight, meaning that they are not emitting their own light. While there are many types of liquid crystal materials such as smectics, nematics and cholesterics, twisted nematic (TN) display mode is the most advanced and popular. A TN pixel cell consists of two glass substrates coated on their inner surfaces with transparent electrodes and separated by several millimeters from each other. A nematic liquid crystal material fills the space between the two substrates and two polarizers are attached on both sides of the pixel with their polarization axis crossed. The polarizer is a three-layer composite film with a stretched iodine doped polyvinyl alcohol (PVA) polarizing film in the center and two outer films for protecting the PVA film from the ambient. Since the two substrates, each having alignment layer, are oriented with their alignments perpendicular to each other, liquid molecule is twisted initially. In the voltage-off state, the polarizers are oriented perpendicular and the incoming light from a back light source, whose polarity is twisted by the liquid crystal, is transmitted through the output polarizer. When a voltage is applied to the electrodes, the director of the molecules tends to orient themselves parallel to the applied field, since liquid crystal materials have positive dielectric anisotropy. In this situation, the polarization of the light transmitted through liquid crystal is crossed to the output polarizer resulting in the cut off of the light and thus creating a black state for the display pixel. This operation is called normally white mode, while normally black mode can be achieved by changing the polarizers to a parallel orientation. Figure 10 shows the configuration a TN pixel cell in a normally white mode.
The transmission (luminance) versus the applied voltage characteristic is shown in Fig. 11. The shown characteristic is for normal viewing angle and indicates that grayscale levels can be achieved by varying the voltage across the LCD. Unfortunately, the transmission – voltage curve is viewing angle dependent, leading to grayscale errors and color shift in a display when it is viewed from significant angles to the display normal.
The equivalent circuit with the parasitic elements of a pixel cell and a typical TFT-LCD pixel layout are shown in fig. 12. The pixel consists of a switch TFT device, with the gate electrode connected to the row driver lines and the source electrode connected to the column driver lines. Furthermore, a storage capacitor is connected in parallel to the LC pixel capacitance.
The aperture part is the light transparent part and it is designated for the placement of the liquid crystal while the TFT, voltage lines and storage capacitor areas are non-light transparent. The ratio between the transparent portion of a pixel and its surrounding electronics is called aperture ratio or fill factor. Furthermore, in the shown layout design, the storage capacitor is connected to an adjacent row line resulting in the maximization of the aperture ration but the load capacitance of the row lines is, also, increased. The counter electrode of the LC pixel capacitor is the common ITO electrode on the opposite substrate (Den Boer, 2005). For large displays, this configuration is difficult to be used due to the large RC delay time of the row lines. In order to overcome this problem, a common storage bus can be placed in the aperture area which reduces the load capacitance of the row lines, but also reduces the aperture ration of the pixel.
The crosstalk effect is caused due to the column-line video-signal coupling during one frame and a DC component is being added to the AC data voltage. The DC component can not be entirely eliminated for all gray across the entire pixels matrix, resulting to slight difference in the pixel transmittance between the odd and even frames. A solution to this problem is the polarity inversion method. Apart from elimination of the DC component, the influence of the flicker on the display image quality is also eliminated with the use of a polarity inversion method. Four different polarity inversion methods have been widely used. Figure 13 shows the configuration of the four polarity inversion methods. The type of the polarity inversion method has an impact on the power consumption of the display. In the frame inversion method, all the pixels are driven to + Vp polarity in one frame period and then all of them are driven to – Vp polarity during the next frame period. This method is the most power-efficient method. However, this method is sensitive to the flicker and to vertical and horizontal crosstalk, meaning that this method can not be used in high image quality displays.
In the line and column inversion methods, the polarity of the pixels is alternated in the adjacent rows and columns, respectively. The line inversion method is compatible to the Vcom modulation (Den Boer, 2005) while column inversion method is not compatible. Furthermore, the line inversion method consumes more power than the column inversion method because the capacitance of all row busses is charged and discharged every row time. Finally, the column inversion method has better results to the compensation of the flicker.
In the pixel inversion method, the polarity of each pixel is inverted from the polarity of its neighbouring pixels, by a combination of simultaneous row and column inversions. This produces the highest quality images by total elimination of the flicker and crosstalk effect. This method is not compatible with the Vcom modulation and thus it requires high voltage column drivers leading to high power consumption.
A full color LCD display can be generated by incorporating red, green and blue color filters at the pixels. In order to produce the desirable color tone, the pixel is divided into three sub-pixels each one having red, green and blue color filter, respectively. The three sub-pixels have the same dimensions and the proper combination of each color tone; by applying the right voltages to the liquid crystals, the desired pixel emissive colour will be produced. The width of each sub-pixel is three times smaller than the sub-pixel length and when the three sub-pixels are very closely placed in parallel, a square full color pixel is produced. Figure 14 shows a full colour square pixel.