LCD Module
LCM (LCD Module) is the LCD display module, liquid crystal module, refers to the liquid crystal display device (TFT/LCD), control and drive peripheral circuit (IC),FPC/PCB circuit board, backlight, structural parts (iron frame) and other components assembled together.
Small and medium-sized LCM modules are widely used in mobile phones, MP3, MP4, digital cameras, digital video cameras, digital photo frames, game consoles, learning machines, GPS, car displays, handheld computers, portable TV and other multimedia video and audio products. There will be more types and it will be more flexible in demand market.
LCD Module
LCM (LCD Module) is the LCD display module, liquid crystal module, refers to the liquid crystal display device (TFT/LCD), control and drive peripheral circuit (IC),FPC/PCB circuit board, backlight, structural parts (iron frame) and other components assembled together.
Small and medium-sized LCM modules are widely used in mobile phones, MP3, MP4, digital cameras, digital video cameras, digital photo frames, game consoles, learning machines, GPS, car displays, handheld computers, portable TV and other multimedia video and audio products. There will be more types and it will be more flexible in demand market.
Module Structure
Connectors
LCM module is an integrated module of liquid crystal display, usually composed of liquid crystal panel, drive circuit, backlight, casing, etc.
Additional Function Modules
Some LCM modules may also include some additional function modules, such as Touch Panel, Ambient Light Sensor, temperature sensor, etc., to provide richer functions and better user experience.
Connectors
LCM modules usually have a variety of connection interfaces for connecting with external systems or devices, such as power interface, signal interface (usually parallel or serial interface), touch screen interface, etc.
Driver Circuit
The driver circuit is the circuit part that controls the LCD panel, usually composed of the driver IC and related circuits. The driving circuit is responsible for generating the driving signal and controlling the arrangement of the liquid crystal molecules to achieve the display effect. The drive circuit may also include a control circuit for the touch screen, backlight, etc.
Backlight
The backlight provides the light source so that the image on the LCD panel can be illuminated and displayed. Common backlights include LED (Light Emitting Diode) backlights and CCFL (Cold Cathode Fluorescent Lamp) backlights. The backlight source is usually located behind the LCD panel and the light is evenly illuminated to the LCD panel through a specific optical structure.
Casing
LCM modules typically include a casing to protect the LCD panel, drive circuit and backlight while providing mounting and securing support structures. Shell design and material selection may vary depending on application scenarios and requirements.
LCD Panel
The LCD panel is the core component of the LCM module and is composed of liquid crystal materials. The liquid crystal panel itself is usually composed of a multi-layer film, including liquid crystal layer, conductive layer and glass substrate. The LCD panel is responsible for adjusting the arrangement state of the liquid crystal molecules according to the driving signal, so as to achieve the display.
Liquid Crystal Display
The structure of the LCD is to place liquid crystals in two parallel pieces of glass. There are many small vertical and horizontal wires in the middle of the two pieces of glass. Through the power supply, the rod crystal molecules are controlled to change the direction and the light is refracted to produce the picture.
Integrated Circuits
Integrated circuits are bonded to the LCD through the COG process, which drives the LCD to display the picture.
Polarizer
Its main function is to convert the natural light that is not biased into a biased aurora, so that the light that is perpendicular to the electric field passes through and the liquid crystal molecule torsion characteristics achieve the control of the light through or not, so that the LCD panel can display the image normally.
Flexible Printed Circuit
Also known as soft circuit board, flexible printed circuit board. Thus, the FPC is connected to the mobile phone motherboard and powered on to make the display module display normally.
Touch Panel
An electronic device that can respond to the surface contact of the display screen (finger, pen) by relying on a computer to recognize the position of its touch.
Display Principle
Polarizer- Grating (light fence) Action
Light has a wave, the direction of travel of light waves is perpendicular to the electric field and magnetic field and the electric field and magnetic field components of light waves are also perpendicular to each other. That is to say, the direction of travel and the electric and magnetic field components are parallel to each other. The polarizer acts like a fence, blocking components perpendicular to the fence and allowing only components parallel to the fence to pass through.
If the two polarizers are stacked together, when the relative Angle of the two polarizers is rotated, it will be found that the brightness of the light will become darker and darker with the different relative angles. When the Angle of the fence of the two polarizers is perpendicular to each other, the light cannot pass through at all.
LCD Structure
LCD structure: There is a liquid crystal layer between the two glass substrates and the electric field of the upper and lower substrates is controlled by the TFT element to achieve the rotation of the liquid crystal molecules to achieve the purpose of display
The liquid crystal molecules are arranged inside the LCD
The liquid crystal molecules are arranged in a spiral pattern inside the LCD box, twisting 90 degrees between the two surfaces (figure below). When the light passes through the unenergized LCD, it becomes polarized light through the first layer of polarizer and when the polarized light passes through the inside of the LCD, it is affected by the spiral arrangement of liquid crystal molecules and the polarization direction of the light is rotated 90 degrees, which is just the same direction as the polarizer of the other layer then the light could passes smoothly.
(Note: The front and back of the two polarizer optical axis direction perpendicular to each other)
When the LCD electrode is charged, the liquid crystal molecules are rearranged in the direction of the electric field. It will no longer have a spiral distribution, so the polarized light is no longer rotating and when it reaches the second polarizer, it cannot pass through.
It is through the power control of the LCD electrodes at both ends of the liquid crystal that the liquid crystal is constantly rotating inside the LCD to achieve the passing or blocking of light, so as to achieve the display of white screen (light through) and black screen (light blocking). If there is an opportunity to hold a magnifying glass, as shown in the figure below (the colors here reflect the colors of the color filter on the LCD).We know that red, blue and green are the so-called three primary colors. Using these three colors, you can mix a variety of different colors. Many flat displays use this principle to display colors. We divide the RGB three colors into three independent points, each with different grayscale changes and then take the three adjacent RGB display points as a basic unit of display, that is, pixel. Then this pixel can have different color changes.
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