For newly added or unfamiliar customers, the basic concept of LED display is rather vague. Xiao Bian summed up the basic knowledge of LED display screen and can help friends have a clear and intuitive understanding:
First, the concept and type of LED
An LED, a light emitting diode, is a tiny electronic semiconductor that converts electrical energy into visible light. The type of chemicals used in the LED determines its color, brightness, and power. There is no filament in the LED lamp, and there will be no burning or damage of the incandescent filament.
LED has two different forms, namely surface mount and in-line package. The table sticker refers to the mounting method of the LED lead frame. LED lamp beads are mounted on the surface of the circuit board. SMD contains red, green, and blue chips. The in-line LED is connected to the circuit board through the lead wire and has a higher position. Each LED lamp bead is a red, green and blue monochromatic lamp bead.
Second, the surface mount SMD
Because there is no directional reflector, surface-mounted LED lamp beads do not focus. In contrast, light is evenly spread over horizontal and vertical angles to provide a wider viewing angle. This makes surface-mount LED displays ideal for most indoor applications as well as some compact-pitch outdoor applications.
Three, in-line DIP
The in-line LED lamp uses reflector cups and epoxy lens assemblies. This combination and the type of chip used determine the elliptical cone. The in-line LED reflector cup concentrates light in a specific angular area.
Fourth, LED display technology indicators
1. Module
LED modules are "building block parts" that make up a video wall. The arrangement of modules depends on the product, market, and use.
2. Pixel
Pixels are the abbreviation of image elements and are the basic spot of letters, numbers, graphics, and video. One pixel can be a single LED, multiple colored LEDs, or multiple different colored LEDs. They are the smallest elements of an electronic display system and can be independently controlled or switched at different brightness levels.
3. Resolution
The resolution is the number of pixels in the physical area of ​​the electronic display. The more pixels in a unit area, the stronger the detail display capability. Resolution is determined by display size, pixel technology, pixel pitch, and viewing distance. The following is a comparison of the effect of three different dot spacings:
4. Visual angle
When selecting the display, consider the position and angle at which it will be installed. The best image is available in the viewing cone, so it is best to place the viewer's viewable position within the cone.
The viewing angle or viewing area is greater than the optimum viewing angle, depending on the situation in the field and the ambient light.
5. Viewing distance
The calculation of the viewing distance is mainly based on the type of indoor and outdoor displays and the distance from the display. Each display has a minimum and maximum viewing distance, based on application and usage considerations.
Larger characters will have a longer viewing distance and smaller ones will be shorter. Pixel pitch also varies between indoor and outdoor applications.
Five, point spacing calculation method
The dot pitch is the center distance between each pixel point to each neighboring pixel point.
Each pixel can be a LED light [such as: PH10 (1R)], two LED lights [such as: PH16 (2R)], four LED lights [such as: PH16 (2R1G1B)]. P16 point spacing: 16mm; P20 point spacing: 20mm; P12 point spacing: 12mm...
Six, the distance between the point and the module (box) size
Case Length = Number of Pixels on Long Edge * Dot Spacing
Box width = number of pixels on wide sides * spacing between points
Such as: PH16 length = 16 points × 1.6 = 25.6, height = 8 points × 1.6 = 12.8
PH10 length=32 points×1.0=32, height=16 points×1.0=16
Seven, box / full screen resolution calculation method
Box Resolution=Length*Width/Dot Spacing LED Display Number of Pixels per Square=1,000,000/Pitch
Eight, screen body module number calculation method
Total area ÷ Module length ÷ Module height = Number of modules used
Such as: 10 squares of PH16 outdoor monochrome LED display using the number of modules equal to:
10 square meters ÷0.256 meters ÷0.128 meters=305.17678≈305
More accurate calculation method: length of use module number * height of use module number = total number of modules used
Such as: 5 meters long, 2 meters high PH16 monochrome led display module number:
Long use module number = 5 meters ÷ 0.256 meters = 19.5325 ≈ 20
High use module number = 2 meters ÷ 0.128 meters = 15.625 ≈ 16 pieces
Total number of modules used = 20 x 16 = 320
Nine, LED display visual distance calculation method
RGB color mixing distance Three-color mixing distance of a single color: LED full-color screen viewing distance = pixel spacing (mm) × 500 - pixel spacing (mm) × 1000
The minimum viewing distance can display the distance of the smooth image: LED display visible distance = pixel pitch (mm) × 1000
The most suitable viewing distance The distance at which the viewer can see a highly clear picture: The best viewing distance of the LED display = Pixel pitch (mm) × 3000 - Pixel pitch (mm) × 1000
The farthest viewing distance: LED display distance = screen height (m) × 30 (times)
Limiter & Limit Switch
A limiter for a Tower Crane is a safety device that is installed to prevent the crane from operating beyond its maximum load capacity or from moving beyond its designated working area. It typically consists of sensors, control systems, and alarms to ensure safe operation.
The load limiter is designed to monitor the load being lifted by the crane and automatically stop the crane's movement if the load exceeds the specified limit. It helps prevent overloading, which can lead to structural failure or accidents.
The radius limiter is used to restrict the crane's movement within a specific working area. It ensures that the crane does not extend beyond its designated radius, preventing it from colliding with nearby structures or obstacles.
Both types of limiters are essential safety features in tower cranes to protect workers, equipment, and the surrounding environment. They help ensure that the tower crane operates within its safe working limits and minimize the risk of accidents or damage.