Content Menu
● Understanding LCD Technology
>> Step 1: Prepare the Glass Substrates
>> Step 2: Create the Electrodes
>> Step 3: Assemble the LCD Sandwich
>> Step 4: Fill with Liquid Crystal Material
>> Step 5: Attach Polarizing Filters
>> Step 6: Add Backlight (Optional)
● DIY Tutorial: Building a Basic LCD Display Circuit with Arduino
>> Components
>> Steps
● Considerations for Custom LCDs
>> 1. What is the purpose of the polarizing filters in an LCD?
>> 2. What is ITO-coated glass, and why is it used in LCDs?
>> 4. What are some common applications for custom LCDs?
Liquid Crystal Displays (LCDs) are everywhere, from the screens of our smartphones and laptops to the displays in our cars and appliances[2][13]. They have become an integral part of modern life, offering a versatile and energy-efficient way to display information. But have you ever wondered how these displays are made? Building an LCD screen might seem like a daunting task, but with the right knowledge, materials, and tools, it is possible to create your own custom LCD from scratch[3][6].
This comprehensive guide will walk you through the process of constructing a basic LCD screen, explaining the principles behind LCD technology, the materials required, and the step-by-step instructions for assembling your own display. Whether you're a DIY enthusiast, a student learning about electronics, or simply curious about how things work, this article will provide you with a detailed understanding of LCD construction[3].
Before diving into the construction process, it's essential to understand the basic principles behind LCD technology[2][13]. LCDs work by modulating light using liquid crystals, which are substances that exhibit properties between those of conventional liquids and solid crystals. These liquid crystals can be aligned by an electric field, allowing light to pass through or blocking it[2].
Here's a breakdown of the key components and concepts:
- Liquid Crystals: These are the heart of the display. They respond to an electric field by changing their orientation, which in turn affects the polarization of light passing through them[2].
- Polarizing Filters: These filters only allow light waves that are vibrating in a specific direction to pass through. LCDs use two polarizing filters, oriented at 90 degrees to each other. When the liquid crystals are not aligned, the first filter polarizes the light, the liquid crystals twist the light by 90 degrees, and the light passes through the second filter. When the liquid crystals are aligned by an electric field, they do not twist the light, and the light is blocked by the second filter[2].
- Electrodes: These are transparent, electrically conductive layers, often made of indium tin oxide (ITO), that create the electric field to align the liquid crystals[2][9]. By applying a voltage to specific electrodes, you can control which areas of the LCD are light or dark, creating images or text[9].
- Glass Substrates: These are the supporting layers that hold all the components together. The liquid crystals, polarizing filters, and electrodes are all attached to these glass substrates[5].
- Color Filters: In color LCDs, each pixel is divided into subpixels with red, green, and blue color filters. By controlling the intensity of each subpixel, a wide range of colors can be produced[2].
- Backlight: Since LCDs modulate light rather than emit it, a backlight is needed to make the display visible. This can be a fluorescent lamp, an LED array, or another light source[5].
To build your own basic LCD screen, you will need the following materials[1]:
- Glass Slides: Microscope slides or ITO-coated glass slides can be used as substrates[3]. Pre-coated glass is readily available online[3].
- Polarizing Filters: These can be purchased online or salvaged from old LCD screens[2].
- Liquid Crystal Material:This can be obtained from specialized suppliers[5].
- Conductive Coating (Indium Tin Oxide - ITO): If you're not using pre-coated glass, you'll need a way to apply a transparent conductive coating[3].
- Wire: Jumper wires for connecting the LCD module to the Arduino board[1].
- Sealant: To seal the edges of the LCD and prevent the liquid crystal material from leaking[5].
- Spacers: To maintain a consistent gap between the glass slides[5].
- Electrode Connector: Connect the data pins of the LCD module to the Arduino[5].
- Arduino Uno:[1]
- LCD display module (compatible with Arduino):[1]
- I2C module:[1]
- USB cable (to connect Arduino to a computer):[1]
- Double Battery holder:[1]
- 2 Battery of 3.7V:[1]
Here are the steps to build a basic LCD screen:
- Clean the glass slides thoroughly to remove any dirt or contaminants[5].
- If you're not using ITO-coated glass, you'll need to apply a transparent conductive coating. This can be done through a process called sputtering, but it's often easier to purchase pre-coated glass[3].
- Design the electrode pattern you want to create on the LCD. This could be simple segments for a numeric display or a more complex pattern for a graphic display[5].
- Use a photoresist and etching process to create the electrode pattern on the ITO-coated glass. Alternatively, you can use a laser cutter or even hand-cut the pattern using a sharp blade[5].
- Apply a thin layer of sealant around the edges of one of the glass substrates, leaving a small opening for filling the liquid crystal material[5].
- Place spacers between the glass substrates to maintain a consistent gap. The gap thickness will affect the LCD's performance, so it's important to be precise[5].
- Carefully align the two glass substrates and press them together, ensuring the sealant creates a good seal[5].
- Heat the LCD assembly slightly to make the liquid crystal material more fluid[5].
- Use a syringe or dropper to carefully inject the liquid crystal material into the gap through the opening in the sealant[5].
- Once the gap is filled, seal the opening with more sealant[5].
- Cut the polarizing filters to the size of the glass substrates[2].
- Carefully align and attach the polarizing filters to the outer surfaces of the glass substrates. Make sure the polarization axes are oriented at 90 degrees to each other[2].
- If you want to create a transmissive LCD (one that requires a backlight), you can add a backlight panel behind the LCD[5].
- Connect the backlight to a power source[5].
- Connect the LCD display module to the Arduino[1].
- Connect the data pins of the LCD module to the Arduino[1].
- Upload the code to the Arduino[1].
- Test the LCD display circuit[1].
"Building a Basic LCD Display Circuit with Arduino" is a DIY tutorial that guides you through the process of creating a simple circuit that uses an LCD display module to display text messages[1]. The tutorial covers the necessary materials needed to complete the project, including an Arduino board, LCD display module, jumper wires, and USB cable[1]. The tutorial then takes you through each step of the process, including connecting the LCD module and Arduino, connecting the data pins of the LCD module to the Arduino, uploading the code to the Arduino, and testing the circuit[1]. By the end of the tutorial, you will have a functioning LCD display circuit that you can customize to display any messages you want[1].-
- Arduino Uno[1]
- LCD display module (compatible with Arduino)[1]
- I2C module[1]
- Jumper wires[1]
- USB cable (to connect Arduino to a computer)[1]
- Double Battery holder[1]
- 2 Battery of 3.7V[1]
1. Connect the LCD display module to the Arduino[1].
2. Connect the data pins of the LCD module to the Arduino[1].
3. Upload the code to the Arduino[1].
4. Test the LCD display circuit[1].
- Display Type: Determine if you need a positive or negative display[6]. Positive displays have a light background with dark characters, while negative displays have a dark background with light characters[6].
- Illumination Method: Decide on the illumination method[6]. Options include reflective (using ambient light), transmissive (requiring a backlight), and transflective (a combination of both)[5].
- Driving Technique: Choose the appropriate driving technique[6]. Direct drive is simpler but requires more pins, while multiplex drive reduces the number of pins but increases complexity[6].
- Polarizing Type: Select the appropriate polarizing type[6]. Options include transmissive, reflective, and transflective polarizers[2].
- Connection Method: Determine the connection method[6]. Options include soldering, connectors, and conductive rubber strips[1].
Building your own LCD screen from scratch is a challenging but rewarding project. By understanding the principles of LCD technology and following the steps outlined in this guide, you can create a custom display tailored to your specific needs. Whether you're building a simple numeric display or a more complex graphic display, the knowledge and skills you gain from this project will be invaluable[3][6].
The polarizing filters are essential for creating the contrast in an LCD[2]. They only allow light waves vibrating in a specific direction to pass through. By orienting two polarizing filters at 90 degrees to each other and using liquid crystals to control the polarization of light, the LCD can selectively block or transmit light, creating dark or light areas on the display[2].
ITO-coated glass is glass that has a thin layer of indium tin oxide (ITO)[3][9]. ITO is a transparent, electrically conductive material that is used to create the electrodes in an LCD. These electrodes are used to apply an electric field to the liquid crystals, which controls their alignment and, therefore, the amount of light that passes through[9].
Color LCDs use a similar principle to monochrome LCDs, but with the addition of color filters[2]. Each pixel is divided into subpixels with red, green, and blue color filters. By controlling the intensity of each subpixel, a wide range of colors can be produced. The human eye blends these subpixel colors together to perceive a single color for each pixel[2].
Custom LCDs are used in a wide range of applications, including industrial equipment, medical devices, automotive displays, and consumer electronics[6]. They are particularly useful when a standard LCD doesn't meet the specific size, shape, or functionality requirements of a product[6].
Advantages of building a custom LCD include the ability to create a display that is tailored to specific needs, such as size, shape, and functionality[6]. It can also be more cost-effective for large production runs[6]. Disadvantages include the higher initial investment in equipment and materials, the need for specialized knowledge and skills, and the longer development time[6].
[1] https://www.youtube.com/watch?v=e8BXdKoiUsg
[2] https://www.youtube.com/watch?v=Gx-JVoOFYhs
[3] https://hackaday.com/2016/06/17/how-to-make-a-custom-lcd-from-scratch/
[4] https://docs.arduino.cc/learn/electronics/lcd-displays
[5] https://www.seacomp.com/resources/lcd-construction
[6] https://circuitdigest.com/article/everything-you-need-to-know-to-design-and-build-your-own-custom-custom-lcd-displays
[7] https://core-electronics.com.au/guides/use-lcd-arduino-uno/
[8] https://www.freepik.com/free-photos-vectors/lcd-monitor
[9] https://hackaday.com/2013/12/02/crafting-a-liquid-crystal-display/
[10] https://www.instructables.com/Tutorial-7-the-LCD-Screen-Liquid-Crystal-Display/
[11] https://www.istockphoto.com/photos/liquid-crystal-display
[12] https://www.instructables.com/LCD-Display-Tutorial/
[13] https://www.elprocus.com/ever-wondered-lcd-works/
