Question 1) What is LED?
Answer 1) LED is the abbreviation of LIGHT EMITTING DIODE. LEDs in the LED display industry refer to LEDs that emit visible bands.
Question 2) What is a pixel?
Answer 2) The minimum illumination unit of the LED display has the same meaning as the pixel described in the ordinary computer display.
Question 3) What is pixel pitch?
Answer 3) 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.
Question 4) What is pixel density?
Answer 4) Also known as dot matrix density, it usually refers to the number of pixels per square meter of the display.
Question 5) What is LED Cabinet?
Answer 5) A small unit consisting of several display pixels that are structurally independent and can form an LED display. Typical are 8*8, 8*7, etc.
Question 6) What is DIP?
Answer 6) DIP is the abbreviation of DOUBLE IN-LINE PACKAGE, which is assembled in a double in-line.
Question 7) What is SMT? What is SMD?
Answer 7) SMT is a surface assembly technology ( SURFACE MOUNTED TECHNOLOGY ) and is currently the most popular technology and process in the electronics assembly industry; SMD is a surface mount device. ( SURFACE MOUNTED DEVICE ).
Question 8) What is an LED module?
Answer 8) It has a basic unit with circuit and installation structure, display function, and display function by simple assembly.
Question 9) What is LED display?
Answer 9) A display screen composed of an array of LED devices by a certain control method.
Question 10) What is DIP LED module technology, what are the advantages and disadvantages?
Answer 10) 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 is The pixel density is small.
Question 11) What is surface mount SMD technology module? What are the advantages and disadvantages?
Answer 11) 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. Large pixel density, suitable for indoor viewing: the disadvantage is that the brightness is not high enough, the lamp itself is not good enough.
Question 12) What is sub-surface SMD technology module? What are the advantages and disadvantages?
Answer 12) Sub-surface label is a product between DIP and SMT. Its LED lamp has the same package surface as SMT, but its positive and negative pins are the same as DIP, and it is also soldered through PCB. The advantages are: high brightness, good display effect, disadvantages: complicated process and difficult maintenance.
Question 13) What is 3-in-1? What are its advantages and disadvantages?
Answer 13) 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 .
Question 14) What is three in one line? What are its advantages and disadvantages?
Answer 14) The RGB three independent package SMT lamps 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.
Question 15) What is dual primary color, pseudo color, full color display?
Answer 15) 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 three different colors.
Question 16) What is the brightness？
Answer 16) The intensity of light emitted by the LED display unit per unit area is CD/square meter, which is simply the light intensity emitted by a square meter display.
Question 17) What is the brightness level?
Answer 17) The number of levels of manual or auto-adjustment of the brightness of the entire screen between the lowest and highest brightness.
Question 18) What is grayscale?
Answer 18) Technical processing levels between the darkest and the brightest at the same brightness level.
Question 19) What is the maximum brightness?
Answer 19) Under certain ambient illumination, the primary colors of the LED display are at the maximum brightness and maximum gray level.
Question 20) What is moiré?
Answer 20) When shooting a full-color LED display at work, some irregular water ripples appear on the LED display screen. These water ripples are called “moiré” in physics.
Question 21) What is PCB?
Answer 21) PCB（Printed Circuit Board） is a printed circuit board.
Question 22) What is size of the LED modules?
Answer 22) Refers to the size of the LED module, usually expressed in terms of the length of the LED module multiplied by the width, in millimeters. (320(W) x 160mm(H))
Question 23) What is resolution of the LED modules?
Answer 23) Refers to how many pixels a LED module has, usually expressed by the expression of the number of rows of LED module multiplied by the number of columns. (eg: 64(W)×32(H) pixels)
Question 24) What is BOM?
Answer 24) BOM ( Bill of Material ) is a list of materials
Question 25) What is white balance and what is white balance adjustment?
Answer 25) The white balance we mean is 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.
Question 26) What is contrast?
Answer 26) The ratio of the maximum brightness of the LED display to the background brightness under a certain ambient illumination.
Question 27) What is color temperature?
Answer 27) 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.
Question 28) What is the color difference?
Answer 28) 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 angle is different, and the spectral distribution of different LEDs is 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.
Question 29) What is the frame change frequency?
Answer 29) The number of times the display screen information is updated in a unit time.
Question 30) What is the refresh rate?
Answer 30) The number of times the display screen is repeatedly displayed by the display in unit time.
Question 31) What is the perspective? What is the angle of view? What is the best perspective?
Answer 31) 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 to 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.
Question 32) What is the best line of sight?
Answer 32) Is the content that can be seen completely on the display, and is not flat, the clearest position of the image content relative to the vertical distance of the screen.
Question 33) What is the point of loss? How many?
Answer 33) The pixel points whose illumination state does not match the control requirements are divided into three types: blind point (also known as dead point) and constant bright point (or dark point).
Question 34) What is a static drive? What is a scan driver? What is the difference between the two?
Answer 34) 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 driver does not need the 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.
Question 35) What is constant current drive? What is a constant voltage drive?
Answer 35) 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.
Question 36) What is the general aspect ratio of LED display?
Answer 36) Graphic screen: determined according to the displayed content; video screen: generally 4:3 or close to 4:3; ideal ratio is 16:9.
Question 37) What is the number of points that a control system can control ?
Answer 37) 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.
Question 38) What is nonlinear correction ?
Answer 38) 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. Because the front and back signals are nonlinear, we often call it nonlinear correction.
Question 39) What is the rated working voltage? What is the working voltage? What is the supply voltage?
Answer 39) The rated working voltage refers to the voltage when the voltage is working normally; the working voltage refers to the voltage value of the electrical appliance in the rated voltage range and normal working: the power 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 5V DC12V Solar power supply is generally 12V.
Question 40) What is color distortion?
Answer 40) 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.
Question 41) What is a synchronous system and what is an asynchronous system?
Answer 41) 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.
Question 42) What is blind spot detection technology?
Answer 42) 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.
Question 43) What is power detection?
Answer 43) 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.
Question 44) What is brightness detection? What is brightness adjustment?
Answer 44) The brightness in the brightness detection refers to the ambient brightness of the LED display screen. Through the light sensor, the ambient brightness of the display screen is detected. 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.
Question 45) What is a real pixel? What is a virtual pixel? What kinds of virtual pixels are there? What is pixel sharing?
Answer 45) The real pixel refers to the relationship between the physical pixel number on the 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 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.
Question 46) What is remote control? Under what circumstances?
Answer 46) The so-called remote is not necessarily a long distance. The remote control includes the main control terminal and the controlled terminal in a local area network, and the space distance is not far; and the main control terminal and the controlled terminal 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.
Question 47) What is fiber transmission? What is network cable transmission?
Answer 47) Optical fiber transmission is the conversion of electrical signals into optical signals by transparent glass fiber transmission. The transmission of the network cable is the direct transmission of electrical signals by means of metal wires.
Question 48) Under what circumstances do you use a network cable? When do you use fiber?
Answer 48) 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.
Question 49) What is LAN control? What is internet control?
Answer 49) 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.
Question 50) What is DVI? What is VGA?
Answer 50) DVI(Digital Video Interface) is a digital video interface. It is a digital video signal interface that is now internationally accepted.
Question 51) What is digital signal? What is digital circuit?
Answer 51) 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.
Question 52) What is analog signal and what is analog circuit?
Answer 52) The analog signal means that the value of the signal amplitude is continuous over time; the circuit that processes and controls such a signal is called an analog circuit.
Question 53) What is a PCI slot?
Answer 53) The PCI slot is an expansion slot based on the PCI local 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 computer can achieve.
Question 54) What is AGP slot?
Answer 54) 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.
Question 55) What is GPRS and what is GSM? What is CDMA?
Answer 55) GPRS is a new bearer service developed on the existing GSM system through packet radio service（General Packet Radiosrvice）, mainly used for radio communication; GSM is the “Global System For Mobile Communication” standard uniformly introduced by the European Committee for Standardization in 1992. The use of digital communication technology, unified network standards, to ensure the quality of communication, and the development of more new services to provide users. Code division address（CODE DIVISION MULTIPLE ACCess）: A new and mature wireless communication technology based on spread spectrum technology.
Question 56) Where is the use of GPRS technology for the display?
Answer 56) 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, achieving the purpose of remote control.
Question 57) What is USB interface?
Answer 57) The English abbreviation for USB is UNIVERSAL SERIALBUS, which translates into Chinese: Universal Serial Bus. Also known as the universal serial interface, it can support hot swapping and can connect up to 127 PC external devices: USB1.0 and USB2.0 interface standards.