What is a Segment LCD? - Custom Segment LCD

Segment LCDs, also called static displays or glass-only displays, are constructed of two pieces of ITO (Indium tin oxide) glass with a twisted nematic fluid sandwiched in between. A static display is a segment display with one pin for every one segment.

 

Custom Segment Liquid Crystal Displays (LCDs) are commonly found in products used to measure the pH level of swimming pools, monitors utilized for detecting specific gases in mines, or thermometers employed to check if a child has a fever. Despite being one of the oldest display technologies, they remain among the most popular choices.

 

Segment Liquid Crystal Displays

 

PCB, also called static displays or glass-only displays, are constructed of two pieces of ITO (Indium tin oxide) glass with a twisted nematic fluid sandwiched in between. A static display is a segment display with one pin for every one segment.

 

These displays remain among the most popular technologies in use, with the majority of them being custom. Many individuals perceive the process of designing a custom segment liquid crystal display as intricate and too complex to grasp, except for a select few experienced individuals.

 

 

What Are The Advantages Of Segment Displays?

 

1. Cost-effective: Segment displays are often simpler and cheaper to manufacture compared to other types of displays like LCD or OLED. This makes them a preferred choice for applications where cost is a significant factor.

 

2. High visibility: Segment displays typically produce bright and easily discernible characters or symbols, making them suitable for environments with varying lighting conditions. They are particularly effective in low-light or high-glare situations.

 

3. Ease of use: Segment displays are straightforward to interface with electronic circuits, requiring minimal hardware and software complexity. This simplicity makes them ideal for applications where quick integration is required.

 

4. Longevity: Due to their relatively simple design, segment displays tend to have a longer operational lifespan compared to more complex display technologies. They are less prone to failure and degradation over time.

 

5. Customization: Segment displays offer flexibility in terms of character size, shape, and arrangement. This allows designers to tailor displays to specific application requirements, such as numeric or alphanumeric displays.

 

6. Low power consumption: Segment displays consume less power compared to some other display technologies, making them suitable for battery-powered devices or applications where power efficiency is critical.

 

7. Reliability: Segment displays are robust and resilient to environmental factors such as temperature fluctuations and mechanical shock. This reliability makes them suitable for use in demanding industrial or automotive applications.

 

8. Wide availability: Segment displays are widely available from various manufacturers in different sizes and configurations. This accessibility makes them easy to source for production purposes.

 

Overall, segment displays provide a cost-effective, reliable, and easy-to-use solution for displaying information in a wide range of applications, from consumer electronics to industrial control systems.

 

Operating Temperatures of Segment Displays

 

Segment LCDs, like all LCD display technologies, perform optimally within specific temperature ranges. These temperature ranges are customizable based on your preferences. Generally, there are two standard configurations: normal temperature and wide temperature. The wider the temperature range, the higher the cost of the display.

 

The standard operating temperature range for a segment LCD is 0°C to 50°C. However, it's possible to configure the display with a different fluid that enables operation from -30°C to 80°C (F). Additionally, with the inclusion of a heater, the display can function in temperatures as low as -50°C.

 

Effects of Extreme Temperatures on LCDs

 

When the temperature drops too low, the fluid between the glass layers starts to freeze. As a result, the segments that were "on" at the time of freezing remain illuminated, and the display remains static until the temperature rises. Conversely, when the temperature rises excessively, a black spot may develop in the center of the glass due to fluid boiling. Once the temperature decreases, the display returns to normal operation.

 

Considerations for Image Quality

 

There are four types of Nematic fluids that can be used between the glass layers, each with its own set of advantages and disadvantages.

 

Types of Nematic Fluids:

 

1. TN Fluid (Twisted Nematic): This is the most cost-effective option but has the narrowest viewing angle. It does, however, exhibit faster response times in cold weather compared to STN and FSTN.

2. STN Fluid (Super Twisted Nematic): More expensive than TN, STN offers a wider viewing angle.

3. FSTN Fluid (Film Super Twisted Nematic): This option is pricier than STN but provides sharper contrast compared to TN and STN.

4. VATN (BTN) (Vertically Aligned Twisted Nematic): Available only in negative mode, VATN displays feature light-colored letters on a dark or black background. They produce very bright segments and offer excellent readability.