Liquid crystal screen technical specifications

Tft-lcd is a thin film transistor liquid crystal display, or TFT.TFT liquid crystal is equipped with a semiconductor switch for each pixel. Each pixel can be directly controlled by point pulse, so each node is relatively independent and can be continuously controlled. It not only improves the reaction speed of the display screen, but also can accurately control the color level of the display.TFT liquid crystal display screen is characterized by good brightness, high contrast, strong sense of hierarchy, bright color, but there are also relatively high power consumption and cost deficiencies.

TFT (Thin Film Transistor) is a kind of active matrix liquid crystal display.It can "actively" control individual pixels on the screen, which can greatly improve the response time.Generally, the reaction time of TFT is relatively fast, about 80 milliseconds, and the visual Angle is large, generally reaching about 130 degrees.

TFT LCD polarity conversion mode:

The driving voltage of liquid crystal molecule cannot be fixed in a certain value invariant, otherwise, time is long, liquid crystal molecule can produce polarization phenomenon, lose optical rotation characteristic gradually thereby.Therefore, in order to avoid the destruction of the characteristics of liquid crystal molecules, the driving voltage of liquid crystal molecules must undergo polarity transformation, which requires the display voltage inside the liquid crystal display screen to be divided into two polarity, one is positive polarity, the other is negative polarity.When the voltage of the display electrode is higher than the common electrode voltage, it is called positive polarity.When the voltage of the display electrode is lower than the common electrode voltage, it is called negative polarity.Whether positive polarity or negative polarity, there will be a set of gray order of the same brightness, so when the absolute pressure difference between the upper and lower layers of glass is fixed, the gray order is exactly the same.However, in both cases, the liquid crystal molecules turn in the opposite direction, which can avoid the damage caused by the above characteristics when the liquid crystal molecules are always fixed in one direction.There are four common polarity transformation modes, namely frame by frame, row by row, column by column and point by point.

For the frame-by-frame inverting mode, in the same frame, all the adjacent points of the whole picture have the same polarity, while the polarity of the adjacent frames is different.For the line-by-line inverting mode, it has the same polarity on the same line, but the polarity of adjacent lines is different.For the inverting mode of each column, the polarity of the same column is the same, but the polarity of adjacent columns is different.For the point-by-point inverting method, each point is adjacent to its four points, upper, lower, left and right, the polarity is not the same.

At present the common personal computer liquid crystal display screen, USES the panel polarity transformation way, majority is point by point transformation way, why?The reason is that the display quality of point-to-point inversion is much better than other conversion methods.The table lists the performance comparison of four polarity transformation modes: frame-by-frame inversion, line-by-row inversion, column-by-column inversion and point-by-point inversion.

The so-called Flicker phenomenon is that the picture will have the feeling of Flicker, but it is not a visual effect specially made, but because the gray scale of the displayed picture will change slightly every time the picture is updated, so that the human eye can feel the Flicker of the picture.This is most likely to happen using a frame-by-frame reversal of polarity.Because the whole picture of inverting phase by frame is of the same polarity, when the picture is positive polarity this time, it will become negative polarity next time. If there is a little error in the common voltage, then there will be a difference in the same gray order voltage of positive and negative polarity. Of course, the feeling of gray order will be different, as shown in figure 2.In the case of constantly switching the screen, Flicker phenomenon will occur because the positive and negative polar images appear alternately.And the polarity of other panels, although there will be this Flicker phenomenon, but because it is not like frame by frame invert is at the same time the whole picture together to change the polarity, only a row or a column, or even just a point change polarity, to the human eye feeling, it will feel not obvious.

Crosstalk phenomenon refers to the phenomenon that the data to be displayed between adjacent points will affect each other, so that the displayed picture will have incorrect conditions.Although there are various causes of Ctosstalk phenomenon, as long as the polarity of adjacent points is different, the occurrence of Ctosstalk phenomenon can be reduced.

TFT LCD working principle:

A "Thin Film Transistor" is a Transistor that can appear in a single pixel on a screen.So how do images come about?The basic principle is simple: a display screen is made up of pixels that emit light of any color.In TFTLCD, backlight technology is generally used. In order to accurately control the color and brightness of each pixel, a shutter-like switch needs to be installed after each pixel. When the "shutter" is opened, the light can pass through, but when the "shutter" is closed, the light cannot pass through.Of course, technically it's not as simple as it sounds.

Liquid Crystal Display (Liquid Crystal Display) takes advantage of the characteristics of Liquid crystals (Liquid Crystal Display when heated and solid Crystal Display when cooled). Generally, Liquid crystals have three forms:

Clay-like laminated (Smectic) liquid crystals

Nematic liquid crystals resembling small matchsticks

Cholestic liquid crystals

Liquid crystal displays are filamentous, and their molecular structure changes as the environment changes, giving them different physical properties -- allowing light to pass through or block it -- such as shutters.

You know the primary colors, so each pixel on the screen needs to be made up of three similar basic components described above, which control the three colors of red, green and blue respectively.

The most commonly used is Twisted Nematic TFT LCD, and the figure below explains how it works.The existing technologies vary widely, and we'll cover them in more detail in the second part of this article.

There are grooves on both upper and lower floors, in which the upper grooves are arranged longitudinally and the lower grooves are arranged horizontally.The lower layers are arranged horizontally.When the unpressurized liquid crystal is in a natural state, the light rays from the luminescent diagram 2a to the TFT display working principle diagram layer will be distorted to 90 degrees after passing through the interlayer, so as to pass through the lower layer smoothly.

When a voltage is applied between the two layers, an electric field is generated, and the liquid crystals are aligned vertically, so that the light does not twist -- as a result, it cannot pass through the lower layers.

TF:

Color filters can be divided into red, green and blue according to color, and they are arranged on the glass substrate in order to form a set of dot pitch corresponding to one pixel. Each monochrome filter is called sub-pixel.In other words, if a TFT display supports a maximum resolution of 1280 x 1024, then at least 1280 x 3 x 1024 pixels and transistors are required.For a 15 inch TFT displays (1024 x 768) as a pixel is about 0.0188 inch (0.30 mm), for the 18.1 inch TFT displays (1280 x 1024), is 0.011 inches (0.28 mm) as we all know, the pixel is on meaningful for display, the smaller each pixel display could reach maximum resolution will be.However, due to the physical characteristics of transistors, the current size of each pixel of TFT is basically 0.0117 inches (0.297mm), so the maximum resolution for a 15-inch display is only 1280 x 1024.

TFT LCD polarity conversion mode:

The driving voltage of liquid crystal molecule cannot be fixed in a certain value invariant, otherwise, time is long, liquid crystal molecule can produce polarization phenomenon, lose optical rotation characteristic gradually thereby.Therefore, in order to avoid the destruction of the characteristics of liquid crystal molecules, the driving voltage of liquid crystal molecules must undergo polarity transformation, which requires the display voltage inside the liquid crystal display screen to be divided into two polarity, one is positive polarity, the other is negative polarity.When the voltage of the display electrode is higher than the common electrode voltage, it is called positive polarity.When the voltage of the display electrode is lower than the common electrode voltage, it is called negative polarity.Whether positive polarity or negative polarity, there will be a set of gray order of the same brightness, so when the absolute pressure difference between the upper and lower layers of glass is fixed, the gray order is exactly the same.However, in both cases, the liquid crystal molecules turn in the opposite direction, which can avoid the damage caused by the above characteristics when the liquid crystal molecules are always fixed in one direction.There are four common polarity transformation modes, namely frame by frame, row by row, column by column and point by point.

For the frame-by-frame inverting mode, in the same frame, all the adjacent points of the whole picture have the same polarity, while the polarity of the adjacent frames is different.For the line-by-line inverting mode, it has the same polarity on the same line, but the polarity of adjacent lines is different.For the inverting mode of each column, the polarity of the same column is the same, but the polarity of adjacent columns is different.For the point-by-point inverting method, each point is adjacent to its four points, upper, lower, left and right, the polarity is not the same.

At present the common personal computer liquid crystal display screen, USES the panel polarity transformation way, majority is point by point transformation way, why?The reason is that the display quality of point-to-point inversion is much better than other conversion methods.The table lists the performance comparison of four polarity transformation modes: frame-by-frame inversion, line-by-row inversion, column-by-column inversion and point-by-point inversion.

The so-called Flicker phenomenon is that the picture will have the feeling of Flicker, but it is not a visual effect specially made, but because the gray scale of the displayed picture will change slightly every time the picture is updated, so that the human eye can feel the Flicker of the picture.This is most likely to happen using a frame-by-frame reversal of polarity.Because the whole picture of inverting phase by frame is of the same polarity, when the picture is positive polarity this time, it will become negative polarity next time. If there is a little error in the common voltage, then there will be a difference in the same gray order voltage of positive and negative polarity. Of course, the feeling of gray order will be different, as shown in figure 2.In the case of constantly switching the screen, Flicker phenomenon will occur because the positive and negative polar images appear alternately.And the polarity of other panels, although there will be this Flicker phenomenon, but because it is not like frame by frame invert is at the same time the whole picture together to change the polarity, only a row or a column, or even just a point change polarity, to the human eye feeling, it will feel not obvious.

Crosstalk phenomenon refers to the phenomenon that the data to be displayed between adjacent points will affect each other, so that the displayed picture will have incorrect conditions.Although there are various causes of Ctosstalk phenomenon, as long as the polarity of adjacent points is different, the occurrence of Ctosstalk phenomenon can be reduced.

TFT LCD working principle:

A "Thin Film Transistor" is a Transistor that can appear in a single pixel on a screen.So how do images come about?The basic principle is simple: a display screen is made up of pixels that emit light of any color.In TFTLCD, backlight technology is generally used. In order to accurately control the color and brightness of each pixel, a shutter-like switch needs to be installed after each pixel. When the "shutter" is opened, the light can pass through, but when the "shutter" is closed, the light cannot pass through.Of course, technically it's not as simple as it sounds.

Liquid Crystal Display (Liquid Crystal Display) takes advantage of the characteristics of Liquid crystals (Liquid Crystal Display when heated and solid Crystal Display when cooled). Generally, Liquid crystals have three forms:

Cholestic liquid crystals

Nematic liquid crystals resembling small matchsticks

Clay-like laminated (Smectic) liquid crystals

Liquid crystal displays are filamentous, and their molecular structure changes as the environment changes, giving them different physical properties -- allowing light to pass through or block it -- such as shutters.

You know the primary colors, so each pixel on the screen needs to be made up of three similar basic components described above, which control the three colors of red, green and blue respectively.

The most commonly used is Twisted Nematic TFT LCD, and the figure below explains how it works.The existing technologies vary widely, and we'll cover them in more detail in the second part of this article.

There are grooves on both upper and lower floors, in which the upper grooves are arranged longitudinally and the lower grooves are arranged horizontally.The lower layers are arranged horizontally.When the unpressurized liquid crystal is in a natural state, the light rays from the luminescent diagram 2a to the TFT display working principle diagram layer will be distorted to 90 degrees after passing through the interlayer, so as to pass through the lower layer smoothly.

When a voltage is applied between the two layers, an electric field is generated, and the liquid crystals are aligned vertically, so that the light does not twist -- as a result, it cannot pass through the lower layers.

TF:

Color filters can be divided into red, green and blue according to color, and they are arranged on the glass substrate in order to form a set of dot pitch corresponding to one pixel. Each monochrome filter is called sub-pixel.In other words, if a TFT display supports a maximum resolution of 1280 x 1024, then at least 1280 x 3 x 1024 pixels and transistors are required.For a 15-inch TFT display (1024 x 768), then a pixel is approximately 0.0188 inches (0.30mm), and for an 18.1-inch TFT display (1280 x 1024), that's 0.011 inches (0.28mm)