hmi man-machine interface products,tft LCD screen manufacturerTechnical indicators:

1. LCD display 0010010 nbsp; 0010010 nbsp;

1. Back structure of the LCD screen In the LCD, the LCD screen generally exists as a whole. This is due to the particularity of the liquid crystal device and the need for special tools for connection and assembly, plus the difficulty of operating technology, etc., manufacturers have LCD liquid crystal display screens, connectors, drive circuit PCB circuit boards, backlights, etc. The device is sealed with a steel plate, leaving only the backlight plug and drive signal input socket. This component is called LCDMODUEL (LCM), also called LCD display module, such as Shenzhen Cardi Electronics Co., Ltd., a professional serial screen module, size: 3. 5-1 0. { {3 inches. It can be seen that the way of this component not only increases the reliability of the work, but also prevents unnecessary accidental losses caused by users' random disassembly. The manufacturer of the liquid crystal display only needs to connect the plug of the backlight and the drive signal socket to the external circuit board, which makes the production process of the whole machine much simpler. For the LCD screen, the number of backlights is different according to the size of the screen size and the display requirements. 00 1 00 1 0 nbsp; 00 1 00 1 0 nbsp;

2. The main technical indicators of the LCD screen directly determine the quality of the display. The current price of LCD devices on the market has a direct relationship with the LCD screen used. 0010010 nbsp; 0010010 nbsp;

(1) pixel pitch 00 1 00 1 0 nbsp; 00 1 00 1 0 nbsp;

The pixel pitch of a liquid crystal display has the same meaning as the dot pitch of a CRT. As we all know, the dot pitch of a CRT (cathode ray tube) display refers to the distance between two adjacent pixels, but due to the different resolution modes and different field refresh rates, the actual dot pitch of the image displayed is somewhat different. Different, so CRT monitors generally indicate that the dot pitch index refers to the minimum dot pitch. The liquid crystal display is different, its pixel number is fixed, there is no maximum and minimum, so the marked pixel pitch is its own inherent dot pitch. 0010010 nbsp; 0010010 nbsp;

This dot pitch determines the higher the resolution of the LCD screen, the smaller the pixel pitch, and vice versa. It can be seen that the pixel pitch is indeed an index that can affect the fineness of the image. For CRT monitors, of course, the smaller the better, but for the LCD monitor, because the principle of displaying images is based on light transmission Therefore, the size of the pixel pitch depends on the maximum possibility that this display method can achieve, so it is not possible to pursue the pixel pitch of the liquid crystal display like the dot pitch of CRT. In fact, as long as the screen size and resolution are the same, the pixel pitch of the LCD screen is basically the same. 0010010 nbsp; 0010010 nbsp;

(2) Response time 0010010 nbsp; 0010010 nbsp;

Due to the viscous nature of the liquid crystal material, the display will be delayed. The response time is a technical indicator that reflects the speed at which each pixel's luminescence reflects an input signal. The smaller the indicator value, the better. The response time is composed of two parts, one is the delay time Tr (also called the rise time) of the input signal when the pixel is turned from bright to dark, and the other is the delay time of the input signal when the pixel is turned from dark to bright (and This is called the fall time, and the sum of these two times is the response time of the LCD. Its unit of measurement is ms (milliseconds). 0010010 nbsp; 0010010 nbsp;

The response time of early liquid crystal displays is usually above 50 ms, so there are shortcomings of smear. Since {{1}} seconds (s) is equal to {{1}} milliseconds (ms), the response time for 50 ms can be up to {{{ {4}}}} Continuous display of {{1}} 000 ÷ 50=20 frames in seconds, and the standard for watching movies smoothly is {{8 }} Pictures, so the speed of 20 pictures will naturally produce smearing (also called trailing), ; 00 {{1}} 00 {{1}} 0 nbsp;

The response time of the new generation of LCD monitors is generally shortened. If the standard is 30 frames per second as the display standard of the TV, the response time required to convert to an LCD monitor is 1000 ÷ 30=33 ms (thereby inferred that the response time of 30 ms is suitable for 33 per second, and the response time of {{6}} ms is suitable for per second {{ 7}} Zhang, the calculation process is as before, omitted here), and today ’s technology can already reach about 10 ms or even smaller (high-end models, l0ms response time is suitable for every second {{8} } 0 photos). Due to the differences and controversies in the response time algorithms of various manufacturers, the response time of the liquid crystal display is preferably within l 6 ms, the smaller the better. The response time threshold is small, the higher the quality of the high-speed motion picture. 00 10 0 10 nbsp; 00 10 0 10 nbsp;

(3) Contrast 0010010 nbsp; 0010010 nbsp;

The liquid crystal itself cannot emit light, it relies on the back light to illuminate the screen. The gray display of the spleen does not mean that there is no back light, that is, the light does not pass through the liquid crystal layer and does not show pixels. Contrast refers to the light transmission level of the LCD display, which is the ratio of the brightness at the brightest point (white) to the lowest point (black) at the same point on the screen. High contrast means relatively high brightness and color. The degree of gorgeousness. The LCD panel with excellent quality and the excellent brightness of the backlight source can provide a full, bright and clear picture with reasonable combination of the two. The contrast of most desktop LCD monitors is currently 200: {{1}} ~ 500: {{1}}. In terms of excellent picture quality, the higher the contrast, the better. With a high-contrast LCD display, the gradation effect of the color will be more obvious, and the color performance will be more rich and lively. 00 {{1}} 00 {{1}} 0 nbsp; 00 {{{1}} 00 {{1}} 0 nbsp;

(4) Brightness 0010010 nbsp; 0010010 nbsp;

Brightness refers to the brightness of the picture, that is, the maximum brightness that the backlight light source can produce, and the unit is cd / square meter. Generally, LCD monitors have the ability to display 200 cd / m². Now mainstream LCD monitors even reach 300 cd / m² or more. Their function is to adapt to different operating environments. If the light in the operating environment is bright, it is easy to see clearly without adjusting the brightness of the LCD. Therefore, the greater the brightness, the greater the range of the environment that can be adapted. At present, there are two ways to increase the brightness. One is to increase the light transmission rate of the liquid crystal panel; the other is to increase the brightness of the background light, that is, to increase the number of lamps. In terms of LCD brightness teaching research, NEC has developed a 500 cd / m² color TFT LCD display module; Panasonic has also developed a technology called ABI (Adaptive Brightness Intonsifier), which is made into a dedicated IC that can effectively Increasing the brightness by 350 cd / m2 ~ 400 cd / m2 For the LCD machine, the brightness index is not as large as possible. Too high brightness will affect the contrast and color performance, and it is more difficult to solve this problem. So remind friends who want to buy a brightness specification of more than 400 cd / m2, please pay attention to the comparison of different brand models, and choose products with less influence on contrast and color saturation in highlight mode. 0010010 nbsp; 0010010 nbsp;

(5) Viewing angle 0010010 nbsp; 0010010 nbsp;

It refers to an indicator that the user can clearly observe all the contents on the screen within a large angle. Since the light source displayed on the liquid crystal display has a certain directivity when output after refraction and reflection, normal images cannot be seen when viewing beyond this range. The horizontal viewing angle means that the vertical normal of the display (that is, the vertical imaginary line in the middle of the display volume three) shall prevail. At a certain angle perpendicular to the left or the right of the normal: it can still: Normally see the displayed image This angle Fan Wei is the horizontal viewing angle of the LCD. Similarly, if the horizontal normal is taken as the standard, the viewing angle up and down is called the vertical viewing angle. 0010010 nbsp; 0010010 nbsp;

At present, the viewing angles of liquid crystal displays on the market are symmetrical. Due to the characteristics of the LCD screen, the horizontal viewing angle is usually greater than the vertical viewing angle. The index parameters of the viewing angle marked on the LCD screen generally refer to the horizontal viewing angle. The larger the viewing angle and the wider the viewing angle range, the better the applicability of the LCD. 0010010 nbsp; 0010010 nbsp;

Since each person's vision is different, we use contrast as a reference standard. The greater the contrast of the image seen at the maximum viewing angle, the better. At present, most products on the market have a viewing angle above 120 degrees, and a considerable number of products have reached 140 degrees or even 160 degrees. Above 140 degrees. 0010010 nbsp; 0010010 nbsp;