LED display knowledge
An LED display is a flat panel display, which uses light-emitting diodes as a video display.
An LED panel is a small display, or a component of a larger display.
They are typically used outdoors in store signs and billboards, and in recent years have also
become commonly used in destination signs on public transport vehicles or even as part of
transparent glass area. LED panels are sometimes used as form of lighting, for the purpose
of general illumination, task lighting, or even stage lighting rather than display.
There are two types of LED panels: conventional (using discrete LEDs) and surface-mounted
device (SMD) panels. Most outdoor screens and some indoor screens are built around discrete
LEDs, also known as individually mounted LEDs. A cluster of red, green, and blue diodes is
driven together to form a full color pixel, usually square in shape. These pixels are spaced
evenly apart and are measured from center to center for absolute pixel resolution.
The largest LED display in the world is over 500 meters long and is located in Suzhou, China,
covering the Yuanrong Times Square. The largest LED television in the world is the Center Hung
Video Display at Cowboys Stadium, which is 160 ft × 72 ft (49 m × 22 m), 11,520 square feet
(1,070 m2).Most indoor screens on the market are built using SMD technology a trend that is
now extending to the outdoor market. An SMD pixel consists of red, green, and blue diodes
mounted in a single package,which is then mounted on the driver PC board. The individual
diodes are smaller than a pinhead and are set very close together. The difference is that
the maximum viewing distance is reduced by 25% from the discrete diode screen with
the same resolution.
Indoor use generally requires a screen that is based on SMD technology and has a minimum
brightness of 600 candelas per square meter (cd/m², sometimes informally called nits).
This will usually be more than sufficient for corporate and retail applications, but under
high ambient-brightness conditions, higher brightness may be required for visibility.
Fashion and auto shows are two examples of high-brightness stage lighting that may
require higher LED brightness.Conversely, when a screen may appear in a shot on a television studio set, the requirement will
often be for lower brightness levels with lower color temperatures; common displays have a
white point of 6500–9000 K, which is much bluer than the common lighting on a television
production set.
For outdoor use, at least 2,000 cd/m² is required for most situations, whereas higher-brightness types of up to 5,000 cd/m² cope even better with direct sunlight on the screen.
(The brightness of LED panels can be reduced from the designed maximum, if required.)
Suitable locations for large display panels are identified by factors such as line of sight,
local authority planning requirements (if the installation is to become semi-permanent),
vehicular access (trucks carrying the screen, truck mounted screens, or cranes), cable runs
for power and video (accounting for both distance and health and safety requirements), power,
suitability of the ground for the location of the screen (if there are no pipes, shallow drains, caves,
or tunnels that may not be able to support heavy loads), and overhead obstructions.
LED is standed for Light Emitting Diode,a kind of semiconductor which is used to give and receive
the electronic signal into infrared rays or light, using the characteristics of compound semiconductor.
This is used for household appliances, remote controller, electric bulletin board, various kinds of
automation appliances. An LED is a solidstate electronic device than emits light when energized
by applying power. The LED die is mounted to a lead frame(see below) which is encapsulated
in an epoxy lens. The epoxy lens directs the emitted light and protects the LED die from physical
damage. The lead frame provides the electrical connections, the physical mounting and a thermal
heat sink to remove the heat generated within the LED. A LED display manufacturer must have an in-
depth understanding of LEDs and their properties, as well as use high quality components in order
to develop effective designs than stand the test of time.
Pixel Pitch means the distance between neighboring pixels.
Pixel Density means the quantity of pixels per square meter.
LED QTY means the quantity of LED lamps per square.
Pixel Configuration means the description of the consistence of a pixel, for instance, we use 1 red
lamp, 1 green lamp, 1 blue lamp to compose a pixel, the pixel configuration is 1R1G1B.
Drive Method: such as static, 1/2 scan, 1/4 scan, 1/8 scan, 1/16 scan, the latter one
contributes to less brightness than the former. We always use the static outdoor, and use
the different kinds of scan indoor.Driving IC is the generic term for several kinds of IC,
that are used to control the LED lamps, and as a bridge between the control system and lamps.
Power supply: it is a kind of device that used as a transfer from 110V or 220V AC into 5V DC. It always
seems like a box in the cabinet
LED Type is the description of LED lamp, for instance, the brand,
the shape in physical, the size of the lamp, etc. Module size means the measurement of a module.
Module resolution means the number of pixels per module.Viewing angle is the maximum angle at
which a display can be viewed with acceptable visual performance. It includes horizontal viewing
angle and vertical viewing angle.The refresh rate means the number of times a display’s image is
repainted or refreshed per second. As it denotes a frequency of a process, the refresh rate is
expressed in hertz. That is, a refresh rate of 75 Hz means the image is refreshed 75 times in
one second. Frame rate, or frame frequency means the frequency (rate) at which an imaging
device produces unique consecutive images called frames. The term applies equally well
to computer graphics,
video cameras, film cameras, and motion capture systems. Frame rate means most often expressed
in frames per second (FPS), and is also expressed in progressive scan monitors as hertz (Hz).
gress Protection (IP) is a European rating that describes the degree of protection provided by
an enclosure of electrical equipment. The rating system consists of the letters IP followed by
two numbers:
The first number indicates the degree of protection against solid foreign object ingress.
The second number indicates the degree of protection against liquid ingress.
According to this system an IP65 enclosure will not allow the ingress of dust and is protected
against jets of water from any direction. IP65 enclosures are ideal therefore for use in wet and wash-down environments for example food preparation areas.
Grey level means A calibrated sequence of grey tones, ranging from black to white. In remote sensing,
electromagnetic radiation falling on a photosensitive receiver generates an electrical current
proportional to the intensity of the radiation. The receiver is usually tuned to specific wavelength
bands and the signal from each receiver is amplified and its intensity classified into different
levels, usually 0 (black) to 256. These are the digital numbers of each of the pixel units that
together make up a remotely sensed frame. In multi-spectral scanning systems, the digital
numbers are classified into grey-scale bands, of which there are usually 10 to 12, but up to
256 shades of grey (brightness) may be used.
The operational lifetime of an LED Display is determined by the lifetime of the LEDs.
LED Manufacturers estimate the LED lifetime to be 100,000 hours under certain
operating conditions. LED Display end of lifetimes is when the frontal brightness has
decreated to 50% of original brightness. Three primary factors determine LED lifetime:
Manufacturing process of the LED ,Driving (powering) method of the LED
Temperatures present at the LED die during operation.
LED thermal management is vitally important to maintaining LED lifetime. Increasing the power
through an LED increases brightness but reduces its lifetime due to increased heat generation.
Increased exposure to higher temperature also shortens the lifetime. LED thermal managerment
can only be done through the LED lead frame by conducting the heat to a Printed Circuit Board
(PCB) and by allowing allowing airflow to cool the LED lead frame. LED Display components must
be designed to handle a wide rang of outdoor environmental factors, such as temperature and
humidity. All components must be coated to protect from possible corrosion.
“Dimming” and ”shading” refer to entirely different functions and the terms should not
be interchanged. The word “dimming” refers to a uniform brightness adjustment across
the entire display to correct
the intensity for ease of reading different ambient light conditions. ”Shading” or color depth,
affects the light output variations of each individual red, green and blue LED to create images
within the display.
Calculation explanation: Each individual red, green and blue LED be in one of two states, either
on or off. This example uses a color data processing of 5 bits for each color is 2 to the 5th power
and multiplying each color’s depth provides the overall color depth of 32,768 colors.
Although ”dimming” and ”shading” have different meanings, some manufacturers will combine
greyscale shading values with dimming values to create a color specification that appears more
impressive on paper than it is capable of producing in the field.Combining shading values with
overall dimming values is a deceiving and misleading practice. Below is an incorrect calculation
that includes dimming as part of the color depth:
Along with proper brightness, a display must have high contrast for good readability. Contrast is
the difference between the background’s “off state” (blank display area) versus the “on state”
(illuminated display area). High contrast increases the readability of a message, much like white
text on a black background, causing readers to focus on what needs to be seen. The highest
contrast appears in a display with a dark border and a consistent dark black background across
the entire display with minimal sunlight reflection. A louver system provides shading and black, non-reflective materials ensure the least amount of reflection. Polycarbonate or acrylic face material
may provide as high a contrast as flat black paint or a black potting encapsulated.
An LED display is a flat panel display, which uses light-emitting diodes as a video display.
An LED panel is a small display, or a component of a larger display.
They are typically used outdoors in store signs and billboards, and in recent years have also
become commonly used in destination signs on public transport vehicles or even as part of
transparent glass area. LED panels are sometimes used as form of lighting, for the purpose
of general illumination, task lighting, or even stage lighting rather than display.
There are two types of LED panels: conventional (using discrete LEDs) and surface-mounted
device (SMD) panels. Most outdoor screens and some indoor screens are built around discrete
LEDs, also known as individually mounted LEDs. A cluster of red, green, and blue diodes is
driven together to form a full color pixel, usually square in shape. These pixels are spaced
evenly apart and are measured from center to center for absolute pixel resolution.
The largest LED display in the world is over 500 meters long and is located in Suzhou, China,
covering the Yuanrong Times Square. The largest LED television in the world is the Center Hung
Video Display at Cowboys Stadium, which is 160 ft × 72 ft (49 m × 22 m), 11,520 square feet
(1,070 m2).Most indoor screens on the market are built using SMD technology a trend that is
now extending to the outdoor market. An SMD pixel consists of red, green, and blue diodes
mounted in a single package,which is then mounted on the driver PC board. The individual
diodes are smaller than a pinhead and are set very close together. The difference is that
the maximum viewing distance is reduced by 25% from the discrete diode screen with
the same resolution.
Indoor use generally requires a screen that is based on SMD technology and has a minimum
brightness of 600 candelas per square meter (cd/m², sometimes informally called nits).
This will usually be more than sufficient for corporate and retail applications, but under
high ambient-brightness conditions, higher brightness may be required for visibility.
Fashion and auto shows are two examples of high-brightness stage lighting that may
require higher LED brightness.Conversely, when a screen may appear in a shot on a television studio set, the requirement will
often be for lower brightness levels with lower color temperatures; common displays have a
white point of 6500–9000 K, which is much bluer than the common lighting on a television
production set.
For outdoor use, at least 2,000 cd/m² is required for most situations, whereas higher-brightness types of up to 5,000 cd/m² cope even better with direct sunlight on the screen.
(The brightness of LED panels can be reduced from the designed maximum, if required.)
Suitable locations for large display panels are identified by factors such as line of sight,
local authority planning requirements (if the installation is to become semi-permanent),
vehicular access (trucks carrying the screen, truck mounted screens, or cranes), cable runs
for power and video (accounting for both distance and health and safety requirements), power,
suitability of the ground for the location of the screen (if there are no pipes, shallow drains, caves,
or tunnels that may not be able to support heavy loads), and overhead obstructions.
LED is standed for Light Emitting Diode,a kind of semiconductor which is used to give and receive
the electronic signal into infrared rays or light, using the characteristics of compound semiconductor.
This is used for household appliances, remote controller, electric bulletin board, various kinds of
automation appliances. An LED is a solidstate electronic device than emits light when energized
by applying power. The LED die is mounted to a lead frame(see below) which is encapsulated
in an epoxy lens. The epoxy lens directs the emitted light and protects the LED die from physical
damage. The lead frame provides the electrical connections, the physical mounting and a thermal
heat sink to remove the heat generated within the LED. A LED display manufacturer must have an in-
depth understanding of LEDs and their properties, as well as use high quality components in order
to develop effective designs than stand the test of time.
Pixel Pitch means the distance between neighboring pixels.
Pixel Density means the quantity of pixels per square meter.
LED QTY means the quantity of LED lamps per square.
Pixel Configuration means the description of the consistence of a pixel, for instance, we use 1 red
lamp, 1 green lamp, 1 blue lamp to compose a pixel, the pixel configuration is 1R1G1B.
Drive Method: such as static, 1/2 scan, 1/4 scan, 1/8 scan, 1/16 scan, the latter one
contributes to less brightness than the former. We always use the static outdoor, and use
the different kinds of scan indoor.Driving IC is the generic term for several kinds of IC,
that are used to control the LED lamps, and as a bridge between the control system and lamps.
Power supply: it is a kind of device that used as a transfer from 110V or 220V AC into 5V DC. It always
seems like a box in the cabinet
LED Type is the description of LED lamp, for instance, the brand,
the shape in physical, the size of the lamp, etc. Module size means the measurement of a module.
Module resolution means the number of pixels per module.Viewing angle is the maximum angle at
which a display can be viewed with acceptable visual performance. It includes horizontal viewing
angle and vertical viewing angle.The refresh rate means the number of times a display’s image is
repainted or refreshed per second. As it denotes a frequency of a process, the refresh rate is
expressed in hertz. That is, a refresh rate of 75 Hz means the image is refreshed 75 times in
one second. Frame rate, or frame frequency means the frequency (rate) at which an imaging
device produces unique consecutive images called frames. The term applies equally well
to computer graphics,
video cameras, film cameras, and motion capture systems. Frame rate means most often expressed
in frames per second (FPS), and is also expressed in progressive scan monitors as hertz (Hz).
gress Protection (IP) is a European rating that describes the degree of protection provided by
an enclosure of electrical equipment. The rating system consists of the letters IP followed by
two numbers:
The first number indicates the degree of protection against solid foreign object ingress.
The second number indicates the degree of protection against liquid ingress.
According to this system an IP65 enclosure will not allow the ingress of dust and is protected
against jets of water from any direction. IP65 enclosures are ideal therefore for use in wet and wash-down environments for example food preparation areas.
Grey level means A calibrated sequence of grey tones, ranging from black to white. In remote sensing,
electromagnetic radiation falling on a photosensitive receiver generates an electrical current
proportional to the intensity of the radiation. The receiver is usually tuned to specific wavelength
bands and the signal from each receiver is amplified and its intensity classified into different
levels, usually 0 (black) to 256. These are the digital numbers of each of the pixel units that
together make up a remotely sensed frame. In multi-spectral scanning systems, the digital
numbers are classified into grey-scale bands, of which there are usually 10 to 12, but up to
256 shades of grey (brightness) may be used.
The operational lifetime of an LED Display is determined by the lifetime of the LEDs.
LED Manufacturers estimate the LED lifetime to be 100,000 hours under certain
operating conditions. LED Display end of lifetimes is when the frontal brightness has
decreated to 50% of original brightness. Three primary factors determine LED lifetime:
Manufacturing process of the LED ,Driving (powering) method of the LED
Temperatures present at the LED die during operation.
LED thermal management is vitally important to maintaining LED lifetime. Increasing the power
through an LED increases brightness but reduces its lifetime due to increased heat generation.
Increased exposure to higher temperature also shortens the lifetime. LED thermal managerment
can only be done through the LED lead frame by conducting the heat to a Printed Circuit Board
(PCB) and by allowing allowing airflow to cool the LED lead frame. LED Display components must
be designed to handle a wide rang of outdoor environmental factors, such as temperature and
humidity. All components must be coated to protect from possible corrosion.
“Dimming” and ”shading” refer to entirely different functions and the terms should not
be interchanged. The word “dimming” refers to a uniform brightness adjustment across
the entire display to correct
the intensity for ease of reading different ambient light conditions. ”Shading” or color depth,
affects the light output variations of each individual red, green and blue LED to create images
within the display.
Calculation explanation: Each individual red, green and blue LED be in one of two states, either
on or off. This example uses a color data processing of 5 bits for each color is 2 to the 5th power
and multiplying each color’s depth provides the overall color depth of 32,768 colors.
Although ”dimming” and ”shading” have different meanings, some manufacturers will combine
greyscale shading values with dimming values to create a color specification that appears more
impressive on paper than it is capable of producing in the field.Combining shading values with
overall dimming values is a deceiving and misleading practice. Below is an incorrect calculation
that includes dimming as part of the color depth:
Along with proper brightness, a display must have high contrast for good readability. Contrast is
the difference between the background’s “off state” (blank display area) versus the “on state”
(illuminated display area). High contrast increases the readability of a message, much like white
text on a black background, causing readers to focus on what needs to be seen. The highest
contrast appears in a display with a dark border and a consistent dark black background across
the entire display with minimal sunlight reflection. A louver system provides shading and black, non-reflective materials ensure the least amount of reflection. Polycarbonate or acrylic face material
may provide as high a contrast as flat black paint or a black potting encapsulated.
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