Analog screen and digital screen
Should be no matter what is the digital or analog screen, the interior of the final drive screen is displayed for a voltage value, can be considered to be analog signals.
Saying one: in addition to all of the pixels on the screen is certainly a digital signal, which is the A/D conversion, the digital screen is not completed in the A/D conversion, but directly into digital signals, analog screen is the input of analog signals, which need to be converted into digital signal through the A/D converter circuit board, it is clear that the digital screen is less than a A/D conversion process, the picture is more powerful, so it is widely used in digital products, but also MP4.
Analog screen and digital screen on the screen itself is no difference, the main difference is in the circuit. Added to the LCD screen pixel is certainly a digital signal. On the edge of the screen there are a lot of drivers on the IC, which is called the drive. On the back of the screen the main circuit board is the controller, the controller will receive the signal converted to meet the driver timing requirements of the driving signal, to drive, light up the corresponding pixel.
Analog screen and digital screen in this writing is the same, their difference is mainly in the input. Digital screen direct input digital signal, RGB each color signal is converted to a number of video processing circuit digital signal, directly into the screen on the control drive, A/D conversion is completed in the previous circuit. And simulation are three color screen input analog signal input, its A/D conversion is completed in the circuit on the LCD screen.
Statement two:
This problem has been said many times. The key difference in the input of the RGB signal is the simulation or the number of the. To point out one error, the actual input to the screen is a specific voltage value, the size of the voltage value determines the size of the liquid crystal, which determines the number of light, it can be considered that the driver screen is the simulation signal, but not the digital signal (RGB signal, of course, the timing signal is digital) input RGB if the simulation screen, the DRIVER IC LCM internal sampling processing, and then put the sample value to TFT. RGB signal input if it is digital, called the digital screen, in the DRIVER IC LXM internal D/A conversion, this part of the work is done by the GAMMA correction circuit.
I want to add it. As shown, this is an equivalent circuit diagram of a liquid crystal panel. When the red gate line is opened (such as the third open), the driver source data (voltage) is along the green line, stored in the Cst (liquid crystal storage capacitor), so that the point of the line is lit, the third lines of each point of the brightness of the storage capacitor voltage. So that the voltage is simulated, the digital signal itself is not the size of the voltage. Whether the driver or the digital signal to the analog signal or digital signal to the driver IC source inside to do the transformation. If the analog signal is source, driver to the voltage corresponding to the sampling points down, and then sent to the source (green line). If the input is a digital signal, source driver to convert digital signal to a voltage value corresponding to the point, and then sent to the source (green line). Digital signals are not directly sent to the source line.
Above, do not know to have a help to you, if you have what do not understand the place, please continue with the placard, everyone together to discuss.
(true color LCD display use LCD TFT and active matrix display, source pole driver source driver and the gate driver (gate driver to control the LCD field effect transistor FET source and gate can be used. Received by the source driver display LCD display column data driver, also known as data (data driver) driver, gate driver control progressive scan.)
Statement three:
Analog screen input signal is analog RGB signal, general each line signal and a reverse, but also with VCOM signal, need + 10V above and - below 10V bias, vertical resolution generally about 230; screen digital input signals into TTL, LVDS several, general red, green, and blue color the 6 to 8 bit digital quantity to represent, no external bias and vertical resolution is generally more than 400.
In fact, digital screen and analog screen are used in digital signal driven display. Now that people are saying that the digital screen and analog screen is from the LCD interface to distinguish, can be directly input analog signal screen is the simulation screen, to enter the digital signal is the digital screen. A A/D converter is used to convert analog signals to digital signals. Digital screen will directly deal with digital signal to display. Digital screen from its signal transmission mode to points, can be divided into TTL, LVDS, etc..
Analog screen and digital screen is no difference between the screen itself, when the driver of the driving ranks of the IC used in the digital signal. Analog screen is in Pingbian.
In the field of touch screen, the simulation screen is called the analog screen. The digital screen is called matrix type, and the analog type has the function of contact and handwriting. Analog screen input signals need to be converted to A/D, calculate the input coordinates, and then by the software to determine the coordinates of the role or function, most of the lead line is four (four line) or five (five line); digital screen only as a table