Glass curtain wall LED display solutions project design and implementation of factors to be considered
Glass curtain wall LED display solutions project design and implementation of factors to be considered
High-rise buildings in the city, many are glass curtain wall structure, which is a very good outdoor advertising carrier, through the LED transparent screen technology means, let the building into a three-dimensional photoelectric advertising carrier. Glass curtain wall LED display in the design of the screen, to consider the display content, space conditions, screen size, pixels and other important factors, at the same time to ensure that the production process, technical indicators and so on suitable for the actual application of the glass curtain wall needs, and then combined with the cost of the project, a reasonable design.
1. Point spacing is an important basis for the LED curtain wall screen model, but also determines the final display effect of the screen. The smaller the model, the smaller the dot pitch, the higher the pixel density, the more suitable for high-definition content playback.
2. Spacing and transmittance is a dilemma of choice, the smaller the spacing, the lower the general transmittance rate. This is because the smaller the pitch, the higher the pixel density, the more LED light beads in the unit area, inevitably lose part of the permeability, and high transmittance happens to be the biggest advantage of the LED transparent screen, and improve the price of transmittance is to expand the pitch, which affects the clarity of the screen and display effect.
3. Viewing distance is an important basis for choosing the model, the farther the viewing distance, the larger the general area of the screen, suitable for selection of large-sized products; the closer the viewing distance, the smaller the area of the screen, choose small-sized products.
But with technological advances, point spacing and transmittance can be further improved to achieve a large ideal balance, such as transmittance rate of 90% or more, pixel density to 3 ~ 6mm pitch.
3.1 Driving system
LED driver part of the function is to receive the color data and drive the LED transparent screen according to the data expressed in the brightness value display, usually constant current, regulated voltage, constant voltage - constant current three ways. Constant current driver circuit output current is constant, the output DC voltage changes with the load resistance, the whole circuit is not afraid of load short circuit, but the load is strictly prohibited completely open circuit. Voltage regulator circuit output a fixed voltage, the output current with the increase or decrease of the load and change, the whole circuit is not afraid of the load open circuit, but the load is strictly prohibited completely short-circuited. Constant voltage and then constant current is the most ideal drive circuit, both to detect the LED current, but also to control the LED voltage, is conducive to improving LED life, reduce power consumption, generally used in high-grade LED products.
3.2 Control system
LED display effect depends on the size of the current and voltage through it, time, etc., so the control system is mainly to control the power output of the LED. At present, PWM (pulse modulation) control mode design of the LED power supply, the conversion efficiency is as high as 80% to 90%, and the output voltage or current is very stable, belongs to the high reliability of the power supply. PWM can control the LED on and off time ratio, by dividing the time ratio into a number of levels, so that the LED displays the corresponding number of gray levels (gray scale). The product of the gray levels of the three primary colors is the number of colors that can be reproduced theoretically on the display, generally 256 levels, and the number of colors reaches 16.7M, which can display 24-bit true color information. Generally, the frequency of PWM is greater than 100Hz, otherwise there will be flickering and scan lines when viewing. Now the grayscale level of 10-bit large screen, refresh frequency is mostly 800 ~ 1000 Hz, LED industry transparent screen refresh rate is generally more than 1920Hz.
2) The whole screen color and brightness of the high degree of consistency and uniformity, point by point calibration. Completely avoid the color difference, dark corners, dark edges, “patching” and other phenomena.
3) Because of the large impact of outdoor light, LED curtain wall screen brightness requirements to reach more than 4000cd / ㎡. And support intelligent adjustment of brightness, according to the surrounding environment, dark and light changes, the more comfortable picture, perfect details appear.
4) Wide viewing angle, support for horizontal 140 ° / vertical 140 ° large viewing angle display, satisfied with the effect of different viewing angles, covering more audience.
Full hidden frame: that is, the LED transparent screen is fixed on the aluminum alloy frame, the upper and lower correspond to the upper and lower beams of the aluminum alloy frame, and the two sides of the glass correspond to the left and right vertical bars of the aluminum alloy frame.
Semi-hidden frame: Since the vertical hidden glass curtain wall and vertical hidden horizontal hidden glass curtain wall are called semi-hidden frame glass curtain wall, so this semi-hidden frame of the curtain wall glass has two ways of installation. Vertical hidden is the glass installation embedded in the groove fixed, left and right horizontal and then glass adhesive paste reinforcement; vertical hidden horizontal Ming curtain wall glass to put the glass in the aluminum alloy inlay groove of the horizontal bar, and then in the glass outside the cover pressure plate, and will be hidden in the back of the glass aluminum alloy vertical bar.
Open frame: open frame curtain wall glass type structure whether it is a skeleton and glass frame made of special aluminum alloy profiles or a steel profile as a skeleton, the aluminum alloy frame in the whole curtain wall will be exposed.
Hanger type: this is a kind of column and stainless steel pendant welding installation, is the four claws of the pendant and curtain wall glass hole connected, a hole corresponding to a claw. Can also be described as first in the four corners of the glass drilled a hole, and then the glass will be fixed in the stainless steel pendant on the four claws.
Skeletonless: the glass on the skeletonless curtain wall can also be called structural glass, this curtain wall is mostly used for the first floor of the building, and the building floor to ceiling windows similar to the glass is installed in the form of hanging, is a use of well-spaced hooks or special profiles from above to suspend the glass hanging up the method. The operation step is to first use special profile hooks fixed in the main frame of the channel steel, and then the channel steel suspension suspended in the bottom of the board or under the beam, to strengthen the rigidity of the glass can also be in the glass above and below the addition of a support frame or a crossbar.
As the appearance of different, different structures, the R & D capabilities and production process requires more. If the manufacturer's technology is not pass, splicing out of the LED screen will be due to the splicing gap is too large, splicing surface discontinuity caused by the appearance of uneven and many other problems, thus affecting the viewing effect, and destroy the overall design of the aesthetics. What's more, the design of the circuit and structure of the LED shaped screen is more complicated, which puts forward high requirements on the R&D capability of the manufacturer.
- First. Spacing
1. Point spacing is an important basis for the LED curtain wall screen model, but also determines the final display effect of the screen. The smaller the model, the smaller the dot pitch, the higher the pixel density, the more suitable for high-definition content playback.
2. Spacing and transmittance is a dilemma of choice, the smaller the spacing, the lower the general transmittance rate. This is because the smaller the pitch, the higher the pixel density, the more LED light beads in the unit area, inevitably lose part of the permeability, and high transmittance happens to be the biggest advantage of the LED transparent screen, and improve the price of transmittance is to expand the pitch, which affects the clarity of the screen and display effect.
3. Viewing distance is an important basis for choosing the model, the farther the viewing distance, the larger the general area of the screen, suitable for selection of large-sized products; the closer the viewing distance, the smaller the area of the screen, choose small-sized products.
But with technological advances, point spacing and transmittance can be further improved to achieve a large ideal balance, such as transmittance rate of 90% or more, pixel density to 3 ~ 6mm pitch.
- Second, packaging technology
- Third, LED control section
3.1 Driving system
LED driver part of the function is to receive the color data and drive the LED transparent screen according to the data expressed in the brightness value display, usually constant current, regulated voltage, constant voltage - constant current three ways. Constant current driver circuit output current is constant, the output DC voltage changes with the load resistance, the whole circuit is not afraid of load short circuit, but the load is strictly prohibited completely open circuit. Voltage regulator circuit output a fixed voltage, the output current with the increase or decrease of the load and change, the whole circuit is not afraid of the load open circuit, but the load is strictly prohibited completely short-circuited. Constant voltage and then constant current is the most ideal drive circuit, both to detect the LED current, but also to control the LED voltage, is conducive to improving LED life, reduce power consumption, generally used in high-grade LED products.
3.2 Control system
LED display effect depends on the size of the current and voltage through it, time, etc., so the control system is mainly to control the power output of the LED. At present, PWM (pulse modulation) control mode design of the LED power supply, the conversion efficiency is as high as 80% to 90%, and the output voltage or current is very stable, belongs to the high reliability of the power supply. PWM can control the LED on and off time ratio, by dividing the time ratio into a number of levels, so that the LED displays the corresponding number of gray levels (gray scale). The product of the gray levels of the three primary colors is the number of colors that can be reproduced theoretically on the display, generally 256 levels, and the number of colors reaches 16.7M, which can display 24-bit true color information. Generally, the frequency of PWM is greater than 100Hz, otherwise there will be flickering and scan lines when viewing. Now the grayscale level of 10-bit large screen, refresh frequency is mostly 800 ~ 1000 Hz, LED industry transparent screen refresh rate is generally more than 1920Hz.
- Fourth, the display requirements
2) The whole screen color and brightness of the high degree of consistency and uniformity, point by point calibration. Completely avoid the color difference, dark corners, dark edges, “patching” and other phenomena.
3) Because of the large impact of outdoor light, LED curtain wall screen brightness requirements to reach more than 4000cd / ㎡. And support intelligent adjustment of brightness, according to the surrounding environment, dark and light changes, the more comfortable picture, perfect details appear.
4) Wide viewing angle, support for horizontal 140 ° / vertical 140 ° large viewing angle display, satisfied with the effect of different viewing angles, covering more audience.
- Fifth, the installation method
Full hidden frame: that is, the LED transparent screen is fixed on the aluminum alloy frame, the upper and lower correspond to the upper and lower beams of the aluminum alloy frame, and the two sides of the glass correspond to the left and right vertical bars of the aluminum alloy frame.
Semi-hidden frame: Since the vertical hidden glass curtain wall and vertical hidden horizontal hidden glass curtain wall are called semi-hidden frame glass curtain wall, so this semi-hidden frame of the curtain wall glass has two ways of installation. Vertical hidden is the glass installation embedded in the groove fixed, left and right horizontal and then glass adhesive paste reinforcement; vertical hidden horizontal Ming curtain wall glass to put the glass in the aluminum alloy inlay groove of the horizontal bar, and then in the glass outside the cover pressure plate, and will be hidden in the back of the glass aluminum alloy vertical bar.
Open frame: open frame curtain wall glass type structure whether it is a skeleton and glass frame made of special aluminum alloy profiles or a steel profile as a skeleton, the aluminum alloy frame in the whole curtain wall will be exposed.
Hanger type: this is a kind of column and stainless steel pendant welding installation, is the four claws of the pendant and curtain wall glass hole connected, a hole corresponding to a claw. Can also be described as first in the four corners of the glass drilled a hole, and then the glass will be fixed in the stainless steel pendant on the four claws.
Skeletonless: the glass on the skeletonless curtain wall can also be called structural glass, this curtain wall is mostly used for the first floor of the building, and the building floor to ceiling windows similar to the glass is installed in the form of hanging, is a use of well-spaced hooks or special profiles from above to suspend the glass hanging up the method. The operation step is to first use special profile hooks fixed in the main frame of the channel steel, and then the channel steel suspension suspended in the bottom of the board or under the beam, to strengthen the rigidity of the glass can also be in the glass above and below the addition of a support frame or a crossbar.
- Sixth, the shape of the structure
As the appearance of different, different structures, the R & D capabilities and production process requires more. If the manufacturer's technology is not pass, splicing out of the LED screen will be due to the splicing gap is too large, splicing surface discontinuity caused by the appearance of uneven and many other problems, thus affecting the viewing effect, and destroy the overall design of the aesthetics. What's more, the design of the circuit and structure of the LED shaped screen is more complicated, which puts forward high requirements on the R&D capability of the manufacturer.