LED display industry people gather together, it is easy to talk about LED display products: how much dot spacing, how to refresh, how to use constant current drive... If you don't understand, such chat, do you feel good pressure? Big?
How to do it? They all say the terminology, and many people regard it as a prerequisite for pretending that they understand LED displays. Today, Xiaobian will share with you the most complete explanation of the LED display in history, let you change from the LED display white to the screen emperor!
(Warm reminder, nowadays English abbreviation is more and more applied, and there are more and more ambiguities, so be sure to remember, don't make jokes.)
1. What is LED?
LED is the abbreviation of LIGHT EMITTING DIODE. LEDs in the 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 pixel distance (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.
4. What is the pixel density?
Also known as dot matrix density, it usually refers to the number of pixels per square meter of display.
5. What is the LED display module?
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.
6. What is DIP?
DIP is an abbreviation for DOUBLE IN-LINE PACKAGE, which is a dual in-line assembly.
7. What is SMT? What is SMD?
SMT is the surface assembly technology (short for SURFACE MOUNTED technology), which is a technology and process currently used in the electronics assembly industry; SMD is a surface mount device (short for surface mounted device).
8. What is the LED display module?
It has a basic unit with circuit and installation structure, display function, and display function by simple assembly.
9. What is an LED display?
A display screen composed of an array of LED devices by a certain control method.
10. What is the plug-in module, 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 is The pixel density is small.
11: 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.
12. What is the sub-surface module? What are the advantages and disadvantages?
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;
13. 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 .
14. 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.
15. What is a 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 three different colors.
16: 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;
17: 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.
18. What is grayscale?
Technical processing levels between the darkest and the brightest at the same brightness level
19. What is the maximum brightness?
Under certain ambient illumination, each primary color of the LED display is at the maximum brightness and maximum gray level;
20. 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.
21. What is a PCB?
PCB is (short for printed circuit board) printed circuit board
22. What is the unit 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)
23. What is the resolution of the cell board?
Refers to how many pixels a cell board has, usually expressed by the expression of the number of rows of cell pixels multiplied by the number of columns. (eg 64×32)
24. What is a BOM?
BOM is a bill of materials (abbreviation for bill of material)
25: What is white balance and what is white balance adjustment?
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;
26: What is contrast?
The ratio of the maximum brightness of the LED display to the background brightness under a certain ambient illumination.
27. What is 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.
28. 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 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.
29. What is the frame change frequency?
The number of times the display screen information is updated in a unit time;
30. What is the refresh rate?
The number of times the display screen is repeatedly displayed by the display in unit time;
31: 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 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 line;
32: 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:
33: What is the point of loss? How many?
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);
34. 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 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.;
35. What is constant current drive? What is a constant voltage drive?
Constant current refers to the current value specified in the constant output design within 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;
36. 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.
37. What is the number of points that a control system can control?
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
38. What is 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 nonlinear correction.
39. 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 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
40. 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.
41: What is a synchronous system, 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.
42. What is blind spot detection technology?
Through the upper software and the underlying hardware, 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;
43. 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.
44. What is brightness detection? What is brightness adjustment?
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;
45. What is a 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 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;
46. ​​What is remote control? Under what circumstances?
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;
47. 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 the network cable is the direct transmission of electrical signals by means of metal wires.
48. Under what circumstances use the network cable? When do you 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.
49. What is LAN control? What is internet control?
In the LAN, one computer is used to control another computer or connected to other external devices. This control method is called LAN control. The main controller achieves the control purpose by the IP address of the controller in the INTERNET network, called the Internet. control;
50. 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.
51. 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.
52, what is an analog signal, what is an analog circuit?
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.
53. 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 computer can achieve:
54, what is the 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.
55, what is GPRS, what is GSM? What is CDMA?
GPRS is a new bearer service developed on the existing GSM system through the General Packet Radiosrvice, mainly used for radio communication; GSM is the "Global System For Mobile" unveiled by the European Committee for Standardization in 1992. The abbreviation of Communication (Global System for Mobile Communications), which uses digital communication technology and unified network standards to ensure the quality of communication, and can develop more new services for users to use. CODE DIVISION MULTIPLE ACCess: A new and mature wireless communication technology based on spread spectrum technology.
56, GPRS technology on the use of the display?
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 remote control;
57, what is the USB interface
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 swap, can connect up to 127 PC external devices: There are two interface standards of USB1.0 and USB2.0.
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