tft display construction and working pricelist
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Take your design to the next level with our range of TFT Displays including latest IPS TFT, circular and bar shape as well as large size TFT. With or without touch, these are fully customisable to your system requirements.
TFT-LCD technology is now fairly mature. As a result, manufacturing processes are efficient and production yields are high, leading to very competitive unit prices. Upgrading from a monochrome display to a TFT is now an affordable way to give your product an uplift.
Users of industrial display devices are wanting the same experience they have come to expect from a consumer device with all-round viewing angles. Switching to a superior IPS TFT display has become very cost effective as production increases and unit prices decrease.
Choosing a circular display for your next product design could really set you apart from your competition. Models are available from 1" to 4.2"in TFT, PMOLED and AMOLED, we have something to suit every application.
It is now possible to transform from a monochrome display to a colour display in space constrained systemsby using a letterbox shaped display. These ultra-wide displays are ideal for applications with restricted build height such as rack mount systems or landscape format front panels.
Large TFT display systems are increasingly being used for transportation information, retail signage and vending machines and kiosks. We can supply a large range of TFT solutions up to 65" diameter and in bar-style, square or rectangular configurations.
Anders have partnered with world leading brand Kastus®to offer a globally patentedantimicrobial & antiviralsurface coating which has a proven kill rate of up to 99.99% against harmful bacteria, fungi and antibiotic-resistant superbugs, which makes it particularly useful for products including glass and ceramics. This year, an independent testing report found Kastus to be effective against human Coronavirus on screens.
We are now offering increasing cover lens customisation options and processes to make your TFT LCD user interface truly stand out! Anders’ experienced marketers and engineers work with our manufacturing partners around the world to keep informed of the latest innovations, including mirrored glass,tinted glass, spot-facing, three dimension glass, and many more!
Here at Anders we don"t just strive to design a best in class display solution for your product, but we also want to make sure the display is driven with the right embedded system. We can help achieve a hardware solution that ensures your display works perfectly within your application. Hardware solutions include:
Get started quickly on your new user interface with our HMI development kits. The display, the processor and the OS work together out of the box with optimised QT GUI images. We"ll then optimise the kit to meet exactly your system requirements with our design services.
At Anders we understand that no two customers are the same, which is why we specialise in custom display solutionsand offer unique productstailored to your end application.
See below our range of TFT Displayswith sizes ranging from0.96" to 64.5" and including circular and bar type shape. All our displays can be tailored to suit your application antimicrobial coating technology,
We aim to offer reliable and long-term solutions to our B2B customers. If you are a business and would like to discuss your display and/or embedded system requirements please contact us below
A TFT display is a form of Liquid Crystal Display with thin film transistors for controlling the image formation. The TFT technology works by controlling brightness in red, green and blue sub-pixels through transistors for each pixel on the screen.
There are many display technologies, but do you know which one would be better for your application? Particularly when considering optimum viewing angle and contrast. We discuss 2 of the best options.
Compare IPS vs TFT displays - the TFT display is the display of choice for industrial designs, but it can have its limitations. A newer technology called IPS (in plane switching) offers better viewing angles and colours, but is it really the best choice - we discuss benefits and negatives of both types of TFT display.
A TFT LCD, or a thin film transistor liquid crystal display, is one of the fastest growing forms of display technology today. The thin film transistor (TFT) is a type of semiconductor device used in display technology to enhance efficiency, compactness, and cost of the product. In conjunction with its semiconductor properties, the TFT LCD is an active matrix display, controlling pixels individually and actively rather than passively, furthering the benefits of this semiconductor device.
The TFT LCD is built with three key layers. Two sandwiching layers consist of glass substrates, though one includes TFTs while the other has an RGB, or red green blue, color filter. The layer between the glass layers is a liquid crystal layer.
The Architecture of a TFT Pixelbelow) from the other substrate layer of the device and control the amount of voltage applied to their respective sub-pixels. This layer also has pixel electrodes between the substrate and the liquid crystal layer. Electrodes are conductors that channel electricity into or out of something, in this case, pixels.
On the surface level is the other glass substrate. Just beneath this glass substrate is where the actual pixels and sub-pixels reside, forming the RGB color filter. In order to counteract the electrodes of the previously mentioned layer, this surface layer has counter (or common) electrodes on the side closer to the liquid crystals that close off the circuit that travels between the two layers. In both these substrate layers, the electrodes are most frequently made of indium tin oxide (ITO) because they allow for transparency and have good conductive properties.
Between the two substrate layers lie liquid crystals. Together, the liquid crystal molecules may behave as a liquid in terms of movement, but it holds its structure as a crystal. There are a variety of chemical formulas available for use in this layer. Typically, liquid crystals are aligned to position the molecules in a certain way to induce specific behaviors of passing light through the polarization of the light waves. To do this, either a magnetic or electric field must be used; however, with displays, for a magnetic field to be usable, it will be too strong for the display itself, and thus electric fields, using very low power and requiring no current, are used.
Before applying an electric field to the crystals between the electrodes, the alignment of the crystals is in a 90 degree twisted pattern, allowing a properly crystal-polarized light to pass through the surface polarizer in a display’s “normal white” mode. This state is caused by electrodes that are purposely coated in a material that orients the structure with this specific twist.
However, when the electric field is applied, the twist is broken as the crystals straighten out, otherwise known as re-aligning. The passing light can still pass through the back polarizer, but because the crystal layer does not polarize the lights to pass through the surface polarizer, light is not transmitted to the surface, thus an opaque display. If the voltage is lessened, only some crystals re-align, allowing for a partial amount of light to pass and creating different shades of grey (levels of light). This effect is called the twisted nematic effect.
Fig. 2: On the left is the twisted liquid crystal layer in which polarized light passes freely; on the right is after the electric field is charged into the layer, completely re-aligning the molecule orientations so that light is not polarized and cannot pass through the surface polarizer.
The twisted nematic effect is one of the cheapest options for LCD technology, and it also allows for fast pixel response time. There are still some limits, though; color reproduction quality may not be great, and viewing angles, or the direction at which the screen is looked at, are more limited.
Fig. 3:The top row characterizes the nature of alignment in using IPS as well as the quality of viewing angles. The bottom row displays how the twisted nematic is used to align the crystals and how viewing angles are affected by it.
The light that passes through the device is sourced from the backlight which can shine light from the back or the side of the display. Because the LCD does not produce its own light, it needs to use the backlight in the OLED) have come into use as well. Typically white, this light, if polarized correctly, will pass through the RGB color filter of the surface substrate layer, displaying the color signaled for by the TFT device.
Within an LCD, each pixel can be characterized by its three sub-pixels. These three sub-pixels create the RGB colorization of that overall pixel. These sub-pixels act as capacitors, or electrical storage units within a device, each with their own independent structural and functional layers as described earlier. With the three sub-pixels per pixel, colors of almost any kind can be mixed from the light passing through the filters and polarizer at different brightness based on the liquid crystal alignment.
KING TECH is a TFT LCD IPS supplier solution specialist since 2003, we are the group company combined byAn Innolux authorized LCD panel&IC distribution company
We Provide Different Kinds of Custom TFT Display ServicesIf needed we can make custom size tft displays for customers, we have a good relationship with original TFT display module factories, and we can negotiate with them to tool up an LCD panel mask. The tooling cost will be very high and paid by the end customer, and MOQ is at least 25K/lot.
We are capable to change every structure of the TFT display module. To increase backlight brightness and make it sunlight readable, the highest brightness we’ve ever reached was 6500cd/m2.To change the display FPC shape and length. To customize a resistive touch panel(RTP) or capacitive touch panel(CTP/PCAP), we have a long-term cooperation supplier to work with us on such tooling, for CTP, we can also make different shapes and thicknesses of cover glass, single touch, and multi-touch, AG/AR/AF is also available.
With our own PCBA hardware& software design company, we can design different kinds of TFT display modules for our customers, from simple convert boards to complete motherboards, from HDMI driver boards to Android controller boards, from non-touch function boards to capacitive touch function boards, they are all part of our working.
We have our own TFT display module panel and driver distribution department, if you want to switch to another structure of display, we can also help, cause we know which TFT display module panel and the driver is more match, and which suit’s supply is more stable, which one we can get the lowest price.
In order to give the customer the best support, Kingtech, as one of the best TFT LCD IPS suppliers in China, also can provide industrial solutions such as developing a mother board, serial port UART board, T-CON board, HDMI board, and monitor according to the customer"s requirements.
Kingtech also has existing industrial solutions for the PV135 motherboard, PV901 Linux board, and PV804 motherboard. They can be connected between Raspberry pi and our TFT display module, which can make them work together.
For serial port UART board, Kingtech has a 2.8inch 240x320 LCD with serial port UART board, 3.5inch 320x480 module with serial port UART board, 4.3inch 480x272 display with a resistive touch with serial port UART board, 7inch 800x480/1024x600 TFT with capacitive touch with serial port UART board.
For the HDMI board, Kingtech has a 1.39inch 454x454 AMOLED round with HDMI board, 3.34inch 320x320 TFT round with HDMI board, 3.4inch 800x800 TFT round with HDMI board, 5inch 1080x1080 TFT with HDMI board, 4.3inch 800x480 TFT with HDMI board, 5inch 800x480 LCD with HDMI board, 7inch 800x480/1024x600 LCD display with HDMI board, 10.1inch 1280x800 LCD module with HDMI board.
Above all TFT display modules with board products can be used for industrial equipment, medical, smart-home, or others. Kingtech can also have industrial custom TFT display solutions according to the customer’s requirements. Ware is welcome to contact us. If you are interested in any tft display module products, we can negotiate with you at a reasonable TFT LCD display price. Thank you.
TFT display module is a Thin Film Transistor, and AMOLED is Active-matrix organic light-emitting Display. The TFT display module is backlight-on the liquid crystal panel; AMOLED is a panel that emits light on its own; TFT display module structure is more thick and strong, AMOLED is very thin and also weak, TFT display module is used widely than AMOLED, AMOLED is used in consumer products the most, like a smartwatch, mobile phone, and TV.
IPS is In-Plane Switching, It is also known as free viewing angle, which means the viewing angle of the display on 4 sides is the same, a normal display has its best viewing angle like 6 o’clock or 12 o’clock. While the TFT display module contains normal viewing angles and IPS display,IPS display is a kind of TFT display module.
TFT display module belongs to LCD, LCD is Liquid Crystal Display, it contains mono(single color) LCD and color LCD, single color LCD is barely used now, and color LCD has STN and TFT two types. Therefore, TFT display module is a kind of LCD display.
OLED is Organic Light Emitting Display, it is a display that emits light on its own, and it does not need an extra backlight, so it requests lower power consumption than TFT display module but its lifetime is shorter than TFT(5000 hours), AMOLED is a kind of OLED but it is more colorful. TFT display module requests a backlight to light on and power consumption are higher than OLED, but its lifetime is much longer(20000 hours).
The LED display is working by lighting up the LED lights, the TFT display module is lighted up by the backlight and the liquid crystal starts to work and shows contents. TFT display module has brighter and more true color, and lower price and LED display has lower power consumption, smaller heat, and longer lifetime.
Compares to other types of display, TFT display module is the more widely used, it can be made in different shapes and sizes, from very small sizes to big sizes. The resolution now is higher and higher, and the price of custom TFT display modules is more and more competitive. Its lifetime is longer than the OLED display, and its color is brighter than OLED.
In this Arduino touch screen tutorial we will learn how to use TFT LCD Touch Screen with Arduino. You can watch the following video or read the written tutorial below.
For this tutorial I composed three examples. The first example is distance measurement using ultrasonic sensor. The output from the sensor, or the distance is printed on the screen and using the touch screen we can select the units, either centimeters or inches.
The next example is controlling an RGB LED using these three RGB sliders. For example if we start to slide the blue slider, the LED will light up in blue and increase the light as we would go to the maximum value. So the sliders can move from 0 to 255 and with their combination we can set any color to the RGB LED, but just keep in mind that the LED cannot represent the colors that much accurate.
As an example I am using a 3.2” TFT Touch Screen in a combination with a TFT LCD Arduino Mega Shield. We need a shield because the TFT Touch screen works at 3.3V and the Arduino Mega outputs are 5 V. For the first example I have the HC-SR04 ultrasonic sensor, then for the second example an RGB LED with three resistors and a push button for the game example. Also I had to make a custom made pin header like this, by soldering pin headers and bend on of them so I could insert them in between the Arduino Board and the TFT Shield.
Here’s the circuit schematic. We will use the GND pin, the digital pins from 8 to 13, as well as the pin number 14. As the 5V pins are already used by the TFT Screen I will use the pin number 13 as VCC, by setting it right away high in the setup section of code.
As the code is a bit longer and for better understanding I will post the source code of the program in sections with description for each section. And at the end of this article I will post the complete source code.
I will use the UTFT and URTouch libraries made by Henning Karlsen. Here I would like to say thanks to him for the incredible work he has done. The libraries enable really easy use of the TFT Screens, and they work with many different TFT screens sizes, shields and controllers. You can download these libraries from his website, RinkyDinkElectronics.com and also find a lot of demo examples and detailed documentation of how to use them.
After we include the libraries we need to create UTFT and URTouch objects. The parameters of these objects depends on the model of the TFT Screen and Shield and these details can be also found in the documentation of the libraries.
Next we need to define the fonts that are coming with the libraries and also define some variables needed for the program. In the setup section we need to initiate the screen and the touch, define the pin modes for the connected sensor, the led and the button, and initially call the drawHomeSreen() custom function, which will draw the home screen of the program.
So now I will explain how we can make the home screen of the program. With the setBackColor() function we need to set the background color of the text, black one in our case. Then we need to set the color to white, set the big font and using the print() function, we will print the string “Arduino TFT Tutorial” at the center of the screen and 10 pixels down the Y – Axis of the screen. Next we will set the color to red and draw the red line below the text. After that we need to set the color back to white, and print the two other strings, “by HowToMechatronics.com” using the small font and “Select Example” using the big font.
Next is the distance sensor button. First we need to set the color and then using the fillRoundRect() function we will draw the rounded rectangle. Then we will set the color back to white and using the drawRoundRect() function we will draw another rounded rectangle on top of the previous one, but this one will be without a fill so the overall appearance of the button looks like it has a frame. On top of the button we will print the text using the big font and the same background color as the fill of the button. The same procedure goes for the two other buttons.
Now we need to make the buttons functional so that when we press them they would send us to the appropriate example. In the setup section we set the character ‘0’ to the currentPage variable, which will indicate that we are at the home screen. So if that’s true, and if we press on the screen this if statement would become true and using these lines here we will get the X and Y coordinates where the screen has been pressed. If that’s the area that covers the first button we will call the drawDistanceSensor() custom function which will activate the distance sensor example. Also we will set the character ‘1’ to the variable currentPage which will indicate that we are at the first example. The drawFrame() custom function is used for highlighting the button when it’s pressed. The same procedure goes for the two other buttons.
getDistance(); // Gets distance from the sensor and this function is repeatedly called while we are at the first example in order to print the lasest results from the distance sensor
Here’s that function which uses the ultrasonic sensor to calculate the distance and print the values with SevenSegNum font in green color, either in centimeters or inches. If you need more details how the ultrasonic sensor works you can check my particular tutorialfor that. Back in the loop section we can see what happens when we press the select unit buttons as well as the back button.
Ok next is the RGB LED Control example. If we press the second button, the drawLedControl() custom function will be called only once for drawing the graphic of that example and the setLedColor() custom function will be repeatedly called. In this function we use the touch screen to set the values of the 3 sliders from 0 to 255. With the if statements we confine the area of each slider and get the X value of the slider. So the values of the X coordinate of each slider are from 38 to 310 pixels and we need to map these values into values from 0 to 255 which will be used as a PWM signal for lighting up the LED. If you need more details how the RGB LED works you can check my particular tutorialfor that. The rest of the code in this custom function is for drawing the sliders. Back in the loop section we only have the back button which also turns off the LED when pressed.
In order the code to work and compile you will have to include an addition “.c” file in the same directory with the Arduino sketch. This file is for the third game example and it’s a bitmap of the bird. For more details how this part of the code work you can check my particular tutorial. Here you can download that file:
getDistance(); // Gets distance from the sensor and this function is repeatedly called while we are at the first example in order to print the lasest results from the distance sensor
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White Paper Thin-Film-Transistor (TFT) LCD Display Control Electronics Design and Operation Revision 1.0 DENSITRON TECHNOLOGIES plc. – PROPRIETARY DATA – ALL RIGHTS RESERVED
1 TFT OVERVIEW Thin-Film Transistor (TFT) displays are growing in popularity due to their resolution and speed. Today’s LCD televisions and monitors are built using TFT technologies. The structure and operation of a TFT display is shown in Figure 1. Figure 1: TFT LCD structure and operation Figure 1 demonstrates the electrochemical operation characteristics of a TFT display. The drive electronics of a TFT activate the TFT array substrate, resulting in an induced electromagnetic field that affects the liquid crystal. The liquid crystal is twisted in response to the induced E-field, allowing...
Greyscale Generator Voltage Drive Generator Figure 2: Block Diagram: Elements of TFT drive electronics The Controller logic block controls the instruction and clock signals to the TFT glass’s row and column drivers. The Controller logic block also includes a timing subsection that generates the correct signal cycles to drive the TFT correctly. The Controller logic block will be detailed in Section 2. The Greyscale Generator logic block generates the target reference voltages across a voltage divider circuit to control the brightness and clarity of each color pixel. The Controller logic...
2 TFT CONTROLLER LOGIC 2.1 DRIVERS-ONLY TFT LCD DISPLAYS Figure 3: TFT Row/Column Driver Interface In some applications, engineers prefer to use a drivers-only TFT LCD. Drivers-only interface requires the product engineers to essentially build a TFT controller circuit with control software code programmed into their microprocessor or microcontroller. Therefore, the timing, greyscale generation and voltage drive functions are controlled directly through the application. Design constraints drive the need for drivers-only TFT LCDs. Many PDA and portable applications have tight mechanical...
2.2 CONTROLLER BLOCK DIAGRAM Greyscale Generator Voltage Drive Generator Command and Signal Processor logic Timing Generator Row/Column Driver Control block Figure 4: Controller logic subsections The TFT controller logic block is comprised of 3 blocks; the command and signal processor logic, the timing generator logic and the row/column control logic. The timing generator logic is shown in Figure 5. Timing Generator Logic Block Figure 5: Timing generator logic block 6/17 DENSITRON TECHNOLOGIES plc. – PROPRIETARY DATA – ALL RIGHTS RESERVED
The timing generator logic takes the global timing signals from the application input and generates the specific signal waveforms required for the TFT’s row and column drivers. In addition, the timing generator logic block interacts with the row/column driver control block to ensure the driver control signals are aligned to the specific signal waveforms for proper row/column driver operation. The command and signal processor logic block coordinates the TFT’s input signals and generates the required waveforms to the timing generator logic, the row/column driver logic, the greyscale generator...
2.3 INPUT TIMING WAVEFORMS - EXAMPLE Figure 6: Input Timing Waveforms These waveforms are examples of the required input waveforms for a TFT with built-in controller. Most TFT displays offer the choice of portrait or landscape mode graphics; the waveforms depend on the graphic mode used as well. Since landscape mode require more horizontal pixels than portrait mode, it requires longer instruction cycle times. Note the differences between the horizontal-portrait (top) and horizontal-landscape (middle) waveforms. Most of the instructions, including the RGB inputs, are the same, except for...
3 GREYSCALE GENERATOR/PANEL STABILITY 3.1 Greyscale Generator Voltage Drive Generator Figure 7: Greyscale Generator Circuit, with the voltage latch and summing amplifier circuitry inside the column drivers Figure 7a is an example of the greyscale generator circuit. The greyscale generator consists of an op-amp network that generates distinct V0-V4 voltages. These V0-V4 voltages are then paralleled into the summing amplifier circuits (D/A converter circuits) of the column drivers. In general, the voltage relationship is as follows: 9/17 DENSITRON TECHNOLOGIES plc. – PROPRIETARY DATA – ALL...
V0 < V1 < V2 < V3 < V4 Each D/A converter circuit has a data latch that releases V0-V4 to the summing amplifier according to the instructions from the Controller logic block. The output of the D/A converter circuit sets the voltage applied to a specific cell to control the ‘brightness’ level of the individual pixel. Note that the levels of brightness and color available are dependent on the complexity of the column drivers. Although a TFT LCD panel’s input waveforms may indicate a digital device, the glass panel is not. The liquid crystal lattice reacts to AC voltage waveforms; therefore,...
PANEL STABILITY (REV and VCOM) In Figure 7b, REV and VCOM can be seen to influence the Gamma Curve. However, REV and VCOM play another, more critical, role in a TFT panel operation – to ensure the TFT panel maintain net zero DC voltage throughout its operation. Please note REV is used to generate VCOM. Figure 8 shows the top-level REV/VCOM block diagrams and the circuitry in a TFT panel. Controller Block Controller Block Controller Block Figure 8: REV and the corresponding generated VCOM signal Figure 8a shows the high-level block diagram of the role of REV and VCOM signals. The DC offset...
Figure 9: VCOM circuit: DC offset, VCOM adjustment, and VEE modulation Figure 9 shows a typical VCOM circuit. VCOM needs to be adjusted to match the capacitance and performance specifications of the TFT panel to maximize contrast and minimize flickering. Therefore, the VCOM circuit is tweaked during panel production to ensure consistent performance. Note that in Figure 9’s example, the circuit is constructed to output a typical +1.1V DC Offset. In reality, panels sometimes require a net DC offset to achieve optimum performance due to impurities and other production issues. In addition, VCOM...
In this guide we’re going to show you how you can use the 1.8 TFT display with the Arduino. You’ll learn how to wire the display, write text, draw shapes and display images on the screen.
The 1.8 TFT is a colorful display with 128 x 160 color pixels. The display can load images from an SD card – it has an SD card slot at the back. The following figure shows the screen front and back view.
This module uses SPI communication – see the wiring below . To control the display we’ll use the TFT library, which is already included with Arduino IDE 1.0.5 and later.
The TFT display communicates with the Arduino via SPI communication, so you need to include the SPI library on your code. We also use the TFT library to write and draw on the display.
In which “Hello, World!” is the text you want to display and the (x, y) coordinate is the location where you want to start display text on the screen.
The 1.8 TFT display can load images from the SD card. To read from the SD card you use the SD library, already included in the Arduino IDE software. Follow the next steps to display an image on the display:
Note: some people find issues with this display when trying to read from the SD card. We don’t know why that happens. In fact, we tested a couple of times and it worked well, and then, when we were about to record to show you the final result, the display didn’t recognized the SD card anymore – we’re not sure if it’s a problem with the SD card holder that doesn’t establish a proper connection with the SD card. However, we are sure these instructions work, because we’ve tested them.
In this guide we’ve shown you how to use the 1.8 TFT display with the Arduino: display text, draw shapes and display images. You can easily add a nice visual interface to your projects using this display.
White Paper Thin-Film-Transistor (TFT) LCD Display Control Electronics Design and Operation Revision 1.0 DENSITRON TECHNOLOGIES plc. – PROPRIETARY DATA – ALL RIGHTS RESERVED
1 TFT OVERVIEW Thin-Film Transistor (TFT) displays are growing in popularity due to their resolution and speed. Today’s LCD televisions and monitors are built using TFT technologies. The structure and operation of a TFT display is shown in Figure 1. Figure 1: TFT LCD structure and operation Figure 1 demonstrates the electrochemical operation characteristics of a TFT display. The drive electronics of a TFT activate the TFT array substrate, resulting in an induced electromagnetic field that affects the liquid crystal. The liquid crystal is twisted in response to the induced E-field, allowing...
Greyscale Generator Voltage Drive Generator Figure 2: Block Diagram: Elements of TFT drive electronics The Controller logic block controls the instruction and clock signals to the TFT glass’s row and column drivers. The Controller logic block also includes a timing subsection that generates the correct signal cycles to drive the TFT correctly. The Controller logic block will be detailed in Section 2. The Greyscale Generator logic block generates the target reference voltages across a voltage divider circuit to control the brightness and clarity of each color pixel. The Controller logic...
2 TFT CONTROLLER LOGIC 2.1 DRIVERS-ONLY TFT LCD DISPLAYS Figure 3: TFT Row/Column Driver Interface In some applications, engineers prefer to use a drivers-only TFT LCD. Drivers-only interface requires the product engineers to essentially build a TFT controller circuit with control software code programmed into their microprocessor or microcontroller. Therefore, the timing, greyscale generation and voltage drive functions are controlled directly through the application. Design constraints drive the need for drivers-only TFT LCDs. Many PDA and portable applications have tight mechanical...
2.2 CONTROLLER BLOCK DIAGRAM Greyscale Generator Voltage Drive Generator Command and Signal Processor logic Timing Generator Row/Column Driver Control block Figure 4: Controller logic subsections The TFT controller logic block is comprised of 3 blocks; the command and signal processor logic, the timing generator logic and the row/column control logic. The timing generator logic is shown in Figure 5. Timing Generator Logic Block Figure 5: Timing generator logic block 6/17 DENSITRON TECHNOLOGIES plc. – PROPRIETARY DATA – ALL RIGHTS RESERVED
The timing generator logic takes the global timing signals from the application input and generates the specific signal waveforms required for the TFT’s row and column drivers. In addition, the timing generator logic block interacts with the row/column driver control block to ensure the driver control signals are aligned to the specific signal waveforms for proper row/column driver operation. The command and signal processor logic block coordinates the TFT’s input signals and generates the required waveforms to the timing generator logic, the row/column driver logic, the greyscale generator...
2.3 INPUT TIMING WAVEFORMS - EXAMPLE Figure 6: Input Timing Waveforms These waveforms are examples of the required input waveforms for a TFT with built-in controller. Most TFT displays offer the choice of portrait or landscape mode graphics; the waveforms depend on the graphic mode used as well. Since landscape mode require more horizontal pixels than portrait mode, it requires longer instruction cycle times. Note the differences between the horizontal-portrait (top) and horizontal-landscape (middle) waveforms. Most of the instructions, including the RGB inputs, are the same, except for...
3 GREYSCALE GENERATOR/PANEL STABILITY 3.1 Greyscale Generator Voltage Drive Generator Figure 7: Greyscale Generator Circuit, with the voltage latch and summing amplifier circuitry inside the column drivers Figure 7a is an example of the greyscale generator circuit. The greyscale generator consists of an op-amp network that generates distinct V0-V4 voltages. These V0-V4 voltages are then paralleled into the summing amplifier circuits (D/A converter circuits) of the column drivers. In general, the voltage relationship is as follows: 9/17 DENSITRON TECHNOLOGIES plc. – PROPRIETARY DATA – ALL...
V0 < V1 < V2 < V3 < V4 Each D/A converter circuit has a data latch that releases V0-V4 to the summing amplifier according to the instructions from the Controller logic block. The output of the D/A converter circuit sets the voltage applied to a specific cell to control the ‘brightness’ level of the individual pixel. Note that the levels of brightness and color available are dependent on the complexity of the column drivers. Although a TFT LCD panel’s input waveforms may indicate a digital device, the glass panel is not. The liquid crystal lattice reacts to AC voltage waveforms; therefore,...
PANEL STABILITY (REV and VCOM) In Figure 7b, REV and VCOM can be seen to influence the Gamma Curve. However, REV and VCOM play another, more critical, role in a TFT panel operation – to ensure the TFT panel maintain net zero DC voltage throughout its operation. Please note REV is used to generate VCOM. Figure 8 shows the top-level REV/VCOM block diagrams and the circuitry in a TFT panel. Controller Block Controller Block Controller Block Figure 8: REV and the corresponding generated VCOM signal Figure 8a shows the high-level block diagram of the role of REV and VCOM signals. The DC offset...
Figure 9: VCOM circuit: DC offset, VCOM adjustment, and VEE modulation Figure 9 shows a typical VCOM circuit. VCOM needs to be adjusted to match the capacitance and performance specifications of the TFT panel to maximize contrast and minimize flickering. Therefore, the VCOM circuit is tweaked during panel production to ensure consistent performance. Note that in Figure 9’s example, the circuit is constructed to output a typical +1.1V DC Offset. In reality, panels sometimes require a net DC offset to achieve optimum performance due to impurities and other production issues. In addition, VCOM...
Apollo specializes in TFT-LCD flat panel technologies and supply chain solutions. We offer a huge selection of TFT-LCD monitors and touchscreens, as well as corresponding components. We also offer hardware and software solutions for all of our products and digital signage applications.
As a worldwide supplier of state-of-the-art TFT technologies and system solutions, Apollo Displays supports you in all project phases – 1 from construction of the metal housing and procurement of specific parts to in-house development of controller boards and touchscreen integration.
Display screen is everywhere nowadays. Do you still remember the TVs or computer monitors 20 years ago? They were quadrate, huge and heavy. Now let’s look at the flat, thin and light screen in front of you, have you ever wondered why is there such a big difference?
Actually, the monitors 20 year ago were CRT (Cathode Ray Tube) displays, which requires a large space to run the inner component. And now the screen here in your presence is the LCD (Liquid Crystal Display) screen.
As mentioned above, LCD is the abbreviation of Liquid Crystal Display. It’s a new display technology making use of the optical-electrical characteristic of liquid crystal.
Liquid crystal is a state of substance that has both the characteristics of liquid and solid crystal. It don’t emit light itself, but it can let the light pass perfectly in specific direction. Meanwhile, liquid crystal molecule will rotate under the influence of a electric field, and then the light goes through it will rotate too. That said, liquid crystal can be a switch of light, which is the key in display technology.
STN LCD: STN is for Super-twisted Nematic. The liquid crystal in STN LCD rotate more angles than that in TN LCD, and have a different electrical feature, allowing STN LCD to display more information. There are many improved version of STN LCD like DSTN LCD (double layer) and CSTN LCD (color). This LCD is used in many early phones, computers and outdoor devices.
TFT LCD: TFT is for Thin Film Transistor. It’s the latest generation of LCD technology and has been applied in all the displaying scenario including electronic devices, motor cars, industrial machines, etc. When you see the word ‘transistor’, you may realize there’s integrated circuits in TFT LCD. That’s correct and the secret that TFT LCD has the advantage of high resolution and full color display.
In a simple way, we can divide TFT LCD into three parts, from bottom to top they are: light system, circuit system and light and color control system.In manufacturing process, we’ll start from inner light and color control system and then stretch out to whole module.
It’s accustomed to divide TFT LCD manufacturing process into three main part: array, cell and module. The former two steps are about the production of light and color control system, which contains TFT, CF (color filter) and LC (liquid crystal), named a cell. And the last step is the assembly of cell, circuit and light system.
First, let me introduce a crucial material, ITO, to you. ITO, abbreviation of Indium tin oxide, has the characteristic of electrical conductivity and optical transparency, as well as can be easily deposited as a thin film. Thus it’s widely used to create circuit on glass.
Now let’s turn to the production of TFT and CF. Here is a common method called PR (photoresist) method. The whole process of PR method will be demonstrated in TFT production.
◇ Use glue to build a boundary for LC on both glass. And on CF glass, apply one more layer of conductive adhesive. This enable LC molecule link to the control circuit.
◇ Put the diffuser film and prism film on light source in turn. Together with reflector film, these two films are used to turn the point light from light source into area light and enhance light intensity.
The world of smartphones has been busy for the past few months. There have been numerous revolutionary launches with groundbreaking innovations that have the capacity to change the course of the smartphone industry. But the most important attribute of a smartphone is the display, which has been the focus for all prominent players in the mobile phone industry this year.
Samsung came up with its unique 18:5:9 AMOLED display for the Galaxy S8. LG picked up its old trusted IPS LCD unit for the G6’s display. These display units have been familiar to the usual Indian smartphone buyer. Honor, on the other hand, has just unveiled the new Honor 8 Pro for the Indian market that ships with an LTPS LCD display. This has led to wonder how exactly is this technology different from the existing ones and what benefits does it give Honor to craft its flagship smartphone with. Well, let’s find out.
The LCD technology brought in the era of thin displays to screens, making the smartphone possible in the current world. LCD displays are power efficient and work on the principle of blocking light. The liquid crystal in the display unit uses some kind of a backlight, generally a LED backlight or a reflector, to make the picture visible to the viewer. There are two kinds of LCD units – passive matrix LCD that requires more power and the superior active matrix LCD unit, known to people as Thin Film Transistor (TFT) that draws less power.
The early LCD technology couldn’t maintain the colour for wide angle viewing, which led to the development of the In-Plane Switching (IPS) LCD panel. IPS panel arranges and switches the orientation of the liquid crystal molecules of standard LCD display between the glass substrates. This helps it to enhance viewing angles and improve colour reproduction as well. IPS LCD technology is responsible for accelerating the growth of the smartphone market and is the go-to display technology for prominent manufacturers.
The standard LCD display uses amorphous Silicon as the liquid for the display unit as it can be assembled into complex high-current driver circuits. This though restricts the display resolution and adds to overall device temperatures. Therefore, development of the technology led to replacing the amorphous Silicon with Polycrystalline Silicon, which boosted the screen resolution and maintains low temperatures. The larger and more uniform grains of polysilicon allow faster electron movement, resulting in higher resolution and higher refresh rates. It also was found to be cheaper to manufacture due to lower cost of certain key substrates. Therefore, the Low-Temperature PolySilicon (LTPS) LCD screen helps provide larger pixel densities, lower power consumption that standard LCD and controlled temperature ranges.
The AMOLED display technology is in a completely different league. It doesn’t bother with any liquid mechanism or complex grid structures. The panel uses an array of tiny LEDs placed on TFT modules. These LEDs have an organic construction that directly emits light and minimises its loss by eradicating certain filters. Since LEDs are physically different units, they can be asked to switch on and off as per the requirement of the display to form a picture. This is known as the Active Matrix system. Hence, an Active Matrix Organic Light Emitting Diode (AMOLED) display can produce deeper blacks by switching off individual LED pixels, resulting in high contrast pictures.
The honest answer is that it depends on the requirement of the user. If you want accurate colours from your display while wanting it to retain its vibrancy for a longer period of time, then any of the two LCD screens are the ideal choice. LTPS LCD display can provide higher picture resolution but deteriorates faster than standard IPS LCD display over time.
An AMOLED display will provide high contrast pictures any time but it too has the tendency to deteriorate faster than LCD panels. Therefore, if you are after greater picture quality, choose LTPS LCD or else settle for AMOLED for a vivid contrast picture experience.