Views:32 Author:Site Editor Publish Time: 2019-06-28 Origin:Site
Digital Led Display, whether it is a customer or a practitioner, the customer needs to purchase and communicate with the salesman. Most of the time, the communication is very difficult, because some parameters involved do not understand, and many people in the industry often communicate with each other.
Many LED display parameters and nouns are not understood, so whether it is practitioners or customers, it is necessary to make a general understanding of the common parameter nouns of led display, which is conducive to the stable advancement of the project. It is also conducive to mutual communication, but also a kind of responsible withdrawal to the customer and the project.
LED module is the core of the LED display screen, it is equipped with a LED circuit board and shell, and the LED lamp beads arranged in accordance with certain rules to be packaged together, and then add some waterproofing and composed of a product. With the LED display industry, the continuous development and application of more and more widely, LED module function and role of even more cannot be ignored.
Adhaiwell.com here sorts out the common parameter nouns of the led display to explain, and everyone can become a professional soon.
1. What is led?
LED is the abbreviation of LIGHT EMITTING DIODE. LEDs in the LED display industry refer to LEDs that emit visible bands.
2. What is a pixel?
The minimum illumination unit of the LED display has the same meaning as the pixel described in the ordinary computer display.
3. What is the point spacing?
The center distance between two adjacent pixels, the smaller the spacing, the shorter the visible distance. The industry is often referred to as P to indicate the point spacing. Commonly available are P1.58, P1.9, P2.0, P2.5, P3, P4, P5, P6, P7.62, P8, P10, P12.5, P16, P20, P25, P31.25.
4. What is pixel density?
Also known as dot matrix density, it usually refers to the number of pixels per square meter of display. Divided by pixel density or pixel diameter Since the LED dot matrix module used in the indoor screen has relatively uniform specifications, it is usually divided according to the pixel diameter of the module:
P 3.0mm 62500 pixels / square meter
P 3.75mm 44321 pixels / square meter
P 5.0mm 17222 pixels / square meter
Indoor surface mount pixel points:
P1.58 400689 points / square meter
P1.9 277000 points / square meter
P2.0 250000 points / square meter
P2.5 160000 points / square meter
P3 111111 points / square meter
P4 62500 points / square meter
P5 40000 points / square meter
P6 27777 points / square meter
P7.62 17222 points / square meter
P8 15625 points / square meter
P10 10000 points / square meter
Pixel diameter and number of pixels of the outdoor screen
P10 10000 points / square meter
P12.5 6400 points / square meter
P16 3906 points / square meter
P20 2500 points / square meter
P25 1600 points / square meter
P31.25 1024 points / square meter
5. What is an LED module (cell board)
A small unit consisting of several display pixels that are structurally independent and can form an LED display. Typical 8*8, 8*7, etc., have the basic unit with circuit and installation structure, display function, and display function by simple assembly.
6. What is DIP?
DIP is the abbreviation of DOUBLE IN-LINE PACKAGE, which is assembled in a double in-line manner.
7. What is SMD/STM
SMT is the surface assembly technology (short for SURFACE MOUNTED Technology), which is currently the most popular technology and process in the electronics assembly industry; SMD is the surface mount device (short for surface mounted device).
8. What is the LED display?
A display screen composed of an array of LED devices by a certain control method.
9. What is the straight plug (plug light), what are the advantages and disadvantages?
It means that the lamp of DIP package passes the lamp foot through the PCB board, and the tin is filled in the lamp hole by soldering. The module made by this process is the plug-in lamp group. The advantages are: high brightness, good heat dissipation, and the disadvantage of the pixel density is small.
10. What is a surface mount module? What are the advantages and disadvantages?
The surface mount is also called SMT. The SMT packaged lamp is soldered to the surface of the PCB board through the soldering process. The lamp pins do not need to pass through the PCB board. The module made by this process is called the surface mount module. The advantage is that the display effect is good. The pixel density is large, suitable for indoor viewing: the disadvantage is that the brightness is not high enough, and the heat dissipation of the lamp itself is not good enough.
11. What is 3-in-1? What are its advantages and disadvantages?
It means that the SMT lamps of RGB three different color LED chip packages are vertically juxtaposed at a certain interval, which not only has all the advantages of 3-in-1 but also solves various shortcomings of three-in-one: complicated process and difficult maintenance.
12. What is three-in-one?
The three independent SMT lamps of RGB are vertically juxtaposed at a certain interval, which not only has the advantages of 3-in-1 but also solves various shortcomings of the three-in-one.
13. What is the double primary color, pseudo-color, full-color display?
Different color LEDs can be used to form different display screens. The two primary colors are composed of red, green or yellow and green. The pseudo color is composed of three different colors: red, yellow green and blue. The full color is red. , pure green, pure blue composed of three different colors.
14. What is the brightness of the light?
The intensity of light emitted by the unit area of the LED display, in units of CD/square meter, is simply the intensity of light emitted by a square meter display;
15. What is the brightness level?
The number of levels of manual or auto-adjustment of the entire screen brightness from the lowest to the highest brightness.
16. What is the gray level?
Under the same brightness level, the LED display screen has the technical processing level from the darkest to the brightest. The gray level has multiple description forms, which are described.
17. What is the maximum brightness?
Under certain ambient illumination, each of the primary colors of the LED display is at the maximum brightness and maximum gray level;
18. What is moiré?
When shooting a full-color LED display at work, some irregular water ripples appear on the LED display screen. These water ripples are called "Moore patterns" in physics.
19. What is a PCB board?
PCB is (short for Printed Circuit Board) printed circuit board
20. What is the cell board specification?
Refers to the size of the cell board, usually expressed in terms of the length of the cell board multiplied by the width, in millimeters. (48×244)
21. What is the module (cell board) resolution?
It refers to how many pixels a cell board has, usually the number of rows of cell pixels multiplied by the number of columns. (eg 64×32)
22. What is white balance and what is white balance adjustment?
The white balance we refer to refers to the balance of white, that is, the balance of the brightness ratios of the three colors of RGB; the adjustment of the brightness ratio of the three colors of RGB and the adjustment of the white coordinates is called white balance adjustment;
23. What is the contrast?
The ratio of the maximum brightness of the LED display to the background brightness under a certain ambient illumination.
24. What is the color temperature?
When the color emitted by the light source is the same as the color of the black body at a certain temperature, the temperature of the black body is called the color temperature of the light source.
25. What is the color difference?
The LED display is composed of red, green and blue colors to produce various colors, but the three colors are made of different materials, the viewing angles are different, and the spectral distributions of different LEDs are varied. These differences can be observed. For color difference. When the LED is viewed at a certain angle, its color changes, and the ability of the human eye to judge the color of the real picture (such as a movie picture) is better than that of the observation computer.
26. What is the frame change frequency?
The number of times the LED display screen information is updated in a unit time is to divide the content of the screen we see into multiple segments for playback. The frame change frequency is generally about 60, which is almost invisible to the naked eye.
27. What is the refresh rate?
The display screen of the led display is repeatedly displayed by the display in unit time. The higher the refresh rate, the more delicate the picture.
28. What is the perspective? What is the angle of view? What is the best perspective?
The viewing angle is when the brightness of the viewing direction drops to 1/2 of the brightness of the normal of the LED display. The angle between the two observation directions of the same plane and the normal direction. Divided into horizontal and vertical viewing angles; the viewing angle is the angle between the direction of the image content on the display and the normal of the display screen. The best viewing angle is that you can just see the content on the display, and it is not flat, the angle between the clearest direction of the image and the normal line;
29. What is the best line of sight?
It is just enough to completely see the content on the display, and not flat, the clearest position of the image content relative to the vertical distance of the screen.
30. What is the point of loss? Several kinds?
The pixel points whose lighting state is inconsistent with the control requirements are divided into two types: blind spot (also known as a dead point) and constant bright point (or dark point);
31. What is a static driver? What is a scan driver? What is the difference between the two?
The "point-to-point" control from the output pin of the driver IC to the pixel is called static drive. The control of "point-to-column" from the output pin of the driver IC to the pixel is called scan drive. He needs the line control circuit: The driver board can be clearly seen: the static drive does not need a row control circuit, the cost is high, but the display effect is good, the stability is good, the brightness loss is small, etc.; the scan driver needs the line control circuit, but the cost is low, the display Poor effect, brightness loss, etc.;
At present, there are two kinds of driving methods for LED display on the market: static scanning and dynamic scanning. Static scanning is divided into static real pixels and static virtual. Dynamic scanning is also divided into dynamic real image and dynamic virtual. The driving device is generally made of domestic HC595, Taiwan MBI5026. , Japan Toshiba TB62726, generally has 1/2 scan, 1/4 scan, 1 / 8 scan, 1 / 16 scan.
32. What is the constant current drive? What is the constant voltage drive?
Constant current refers to the current value specified in the constant output design in the working environment allowed by the driver IC: constant voltage refers to the voltage value specified in the constant output design within the working environment allowed by the driver IC;
33. What is the general aspect ratio of LED display?
Graphic screen: determined according to the displayed content; video screen: generally 4:3 or close to 4:3; ideal ratio is 16:9.
34. A set of points that the control system can control
The communication screen A card: monochrome, two-color 1024×64; communication screen B card: monochrome: 896×512 two-color: 896×256; DVI two-color screen: 1280×768; DVI full-color screen: 1024×512.
35. What is a nonlinear correction?
If the digital signal output from the computer is not corrected, the color distortion will appear on the LED display. Therefore, in the system control circuit, the signal output by the original computer is calculated by a nonlinear function. Since the front and back signals are nonlinear, we often call it a nonlinear correction.
36. What is the rated working voltage? What is the working voltage? What is the supply voltage?
The rated working voltage refers to the voltage when the voltage is working normally; the working voltage refers to the voltage value of the appliance under the rated voltage range and normal operation: the supply voltage is divided into the AC and the branch supply voltage and our actual AC supply voltage is AC220V---240V, DC power supply voltage is generally 5VDC12V solar power supply is generally 12V
37. What is color distortion?
It means that the same object is displayed in nature and on the display, and the difference between the two is the sensory vision of the human eye.
38. What is a synchronous system and what is an asynchronous system?
Synchronous and asynchronous are relative to the computer. The so-called synchronization system refers to the LED display control system that displays the content displayed on the display and the computer display. The asynchronous system means that the computer-edited display data is stored in advance. In the display control system, the normal display of the LED display will not be affected after the computer is turned off. Such a control system is an asynchronous control system.
39. What is blind spot detection technology?
Through the upper software and the underlying hardware, the blind spots (LED open and short circuit) on the display screen can be detected, and a report is generated to tell the LED screen manager that such a technology is called blind spot detection technology;
40. What is power detection?
Through the upper software and the underlying hardware, the working status of each power supply on the display can be detected, and a report is generated to tell the LED screen manager that such a technology is called power detection technology.
41. What is brightness detection? What is brightness adjustment?
The brightness in the brightness detection refers to the ambient brightness of the LED display screen. The ambient brightness of the display screen is detected by the light sensor. This detection method is called brightness detection; the brightness mentioned in the brightness adjustment refers to the LED display. The brightness emitted, the detected data is fed back to the LED display control system or the control computer, and then the brightness of the display screen is adjusted according to the data, called brightness adjustment;
42. What is the real pixel? What is a virtual pixel? What are the virtual pixels? What is pixel sharing?
The real pixel refers to the relationship between the physical pixel number on the LED display screen and the actual displayed pixel point is 1:1. How many points actually appear on the display screen can only display the image information of how many points. The virtual pixel refers to the relationship between the physical pixel number of the display screen and the actual displayed pixel number: 1:N (N=2, 4), which can display the image pixel 2 times or 4 times more than the actual pixel of the display screen; Pixels can be divided into virtual and hardware virtual according to the virtual way: divided into 2 times virtual and 4 times virtual according to the multiple relationship, according to the lighting mode on one module: 1R1G1B virtual and 2R1G1B virtual;
43. What is a remote control? Under what circumstances?
The so-called remote is not necessarily a long distance. The remote control includes the main control end and the controlled end in a local area network, and the spatial distance is not far, and the main control end and the controlled end are within a relatively distant spatial distance, and the customer requests or directly exceeds the optical fiber according to the customer control position. Control the distance, then use remote control;
44. What is fiber transmission? What is network cable transmission?
Optical fiber transmission is the conversion of electrical signals into optical signals by transparent glass fiber transmission. The transmission of network cables is the direct transmission of electrical signals by means of metal wires.
45. When is the network cable used? When to use fiber?
When the wiring distance between the display screen and the control computer is less than 100 meters, it is transmitted by the network cable; when the distance between the two is less than 500 meters and more than 100 meters, the multimode fiber is used, and when the distance is more than 500 meters, the single mode fiber is used.
46. What is LAN control? What is internet control?
In the LAN, another computer is controlled by another computer or connected to other external devices. This control method is called LAN control. The main controller is controlled by the IP address of the controller in the INTERNET network, called the Internet. control;
47. What is DVI? What is VGA?
DVI is the abbreviation of Digital Video interface, which is the digital video interface. It is a digital video signal interface that is now internationally accepted.
48. What is a digital signal? What is a digital circuit?
The digital signal means that the value of the signal amplitude is discrete, and the amplitude value is limited to two finite values of 0 and 1. The circuit for processing and controlling the west signal is called a digital circuit.
49. What is an analog signal and what is an analog circuit?
Analog signal means that the value of the signal amplitude is continuous in time; the circuit that processes and controls this signal is called an analog circuit.
50. What is a PCI slot?
The PCI slot is an expansion slot based on a PCI local component bus (PEDPHERD component interconnect). The PCI slot is the main expansion slot of the motherboard. By plugging in different expansion cards, you can get almost all the external functions that the current computer can achieve:
51. What is an AGP slot?
Accelerate the graphics interface. AGP is an interface specification that can be displayed at a faster speed on a normal PC using 3D graphics. AGP is an interface designed to transfer 3D graphics faster and more smoothly. He uses the main memory of a normal PC to refresh the image displayed on the display and supports 3D graphics technology such as texture mapping, zero buffering and alpha blending.
52. What is GPRS and what is GSM? What is CDMA?
GPRS is a new bearer service developed on the existing GSM system through the General Packet Radio service. It is mainly used for radio communication. GSM is the "Global System For" issued by the European Committee for Standardization in 1992. Abbreviation for the Mobile Communication standard (Global System for Mobile Communications), which uses digital communication technology and unified network standards to ensure the quality of communication and to develop more new services for users to use. CODEDI VISION MULTIPLE Access: A new and mature wireless communication technology based on spread spectrum technology.
53. The use of GPRS technology for the display screen is there?
On the GPRS data network based on mobile communication, the data of our LED display screen is communicated through the GPRS transceiver module for data communication, which can realize point-to-point small-scale data transmission remotely and remotely, and achieve the purpose of the remote control;
54. What is a USB interface?
The English abbreviation for USB is UNIVERSAL SERIAL BUS, which translates into Chinese: Universal Serial Bus. Also known as the universal serial interface, it can support hot swap, can connect up to 127 PC external devices: There are two interface standards of USB1.0 and USB2.0.
The common parameters and nouns of the led display are the above. It is not so blind to understand the approximate meaning of these parameters. Although it cannot be directly turned into a professional, it at least plays a very good role in attracting jade, better and better.
Quickly let everyone know the LED display parameter information, and it will be smoother when communicating.
For the project itself, there will be no mistakes.