LED displays are widely used in our daily lives. They can be seen in various applications, such as on the road, home appliances, motorcycles, and more. In addition to these LED displays, there are other advanced technologies with similar structures, such as MicroLED, MiniLED, and OLED.

The LED Display’s Characteristic

The structure of the LED display is simple, allowing it to easily meet outdoor requirements in terms of brightness and color emission by adjusting the LED current and utilizing various LED materials. Additionally, the epoxy-based assembly of the LED display enables it to successfully pass rigorous reliability tests for outdoor applications. The price of standard LED displays is not excessively high, making them widely employed in traffic lights, thermal meter displays, home appliance indicators, countdown meters, and more.

The Non-recurring Engineering Expense (NRE cost) for custom displays, including those with special sizes, heights, additional components, or unique colors, is significantly lower than that of LCD, Mini LED, and Micro LED displays. This is particularly true for displays with irregular shapes and sizes. For more information on the complete customization tooling cost for LED displays, readers can refer to this article.

Generally speaking, in order to customize an LED display, Opto Plus typically requires a tooling cost ranging from US$3,000 to US$6,000, depending on the overall design.

The Structure of LED Displays

LED displays can be categorized into two types based on their structure:

• LED display without reflective cover.

• LED display with reflective cover.

LED Display Structure (Without Reflective Cover)

The structure of an LED display without a reflective cover can be divided into three components:

• Dot matrix display cover

• Light Emitting Diode (LED)

• Printed Circuit Board (PCB)

　　Let’s take the common traffic signal display, also known as the “little green man display,” as an example. This display consists of a dot matrix display cover. The upper section shows the countdown number and the red light stop sign, while the lower section displays a walking animation of a little green man. The light-emitting diodes (LED lamps) are assembled on a printed circuit board (PCB), which handles the circuitry, LED switch control, and production of the digital display and small green man animation for the traffic signal display (referred to as the “Little Green Man monitor”).

　　To reduce costs, most large LED displays are designed without reflective covers. Additionally, in recent years, MiniLED and MicroLED technologies have emerged, which are highly compact and can be used as LED displays without reflective covers when used for display purposes rather than as backlight modules. However, the size and spacing of the LEDs are reduced to millimeter (mm) and micron (μm) levels.

LED Display Structure (With Reflective Cover)

• Light Emitting Diode (LED)

• Printed Circuit Board (PCB)

• Reflective Cover

　　Let’s take the common floor display in an elevator as an example. The floor display consists of a dot matrix display that shows combined icons. The icon in the upper left corner represents the floor number, while the lower section displays an approximate internal structure diagram. The light-emitting diodes (LEDs) are mounted on a printed circuit board (PCB), which contains the necessary circuitry. The display also includes an upper reflective cover, which ensures uniformity of emitted light points and prevents interference between them. The LEDs are arranged in a matrix shape to form the desired display pattern on the elevator floor.

　　This article will primarily focus on introducing LED displays that incorporate reflective covers, such as Seven segment display，Alphanumeric display，Dot matrix display，and Bar graph display。

The structure of an LED display that incorporates a reflective cover can be illustrated using the internal structure of a dot matrix display found on elevator floors as an example.

The Type Of LED Display

The DISPLAY means to display the Words, Pictures, it can be classified to 4 types:

1. Words.
2. A certain picture.
3. Limited words +certain pictures.
4. Any pictures.

Type Of LED Display– 7 Segment Display

　　The main structure of a 7-segment display consists of a 7-segment emitting area and a bottom right emitting area. This is why it is commonly referred to as a “7-segment display” or “8-segment display” (when all segments are lit up, it represents the number 8), or simply as a “numeric display” for displaying numbers. Additionally, most 7-segment displays include a bottom right side emitting area known as the DP point (Data point).

　　At Opto Plus LED Corp., we define each emitting segment in a clockwise manner from segment A to segment G, including the DP point. For more information, please refer to the data sheet or technical specifications of rOPS-S4010SE-GW

If you want to learn more about the internal structure and details of 7-segment displays, please refer to the article titled “Introduce each kind of 7-segment display, 16-segment display , and Internal structure!“.If you are interested in understanding how 7-segment displays can be used to display Arabic numerals or the English alphabet, you can find information in the article titled “How to Representing Numbers and Letters in 7-segment and 16-segment LED display?. Furthermore, if you wish to protect your LED display by using a limited current resistor, you may find the article How to design a 7 segment display with limited current resistor? “ helpful.If you want to learn more about the internal structure and details of 7-segment displays, please refer to the article titled “Introduce each kind of 7-segment display, 16-segment display , and Internal structure!” If you are interested in understanding how 7-segment displays can be used to represent Arabic numerals or the English alphabet, you can find information in the article titled “How to Representing Numbers and Letters in 7-segment and 16-segment LED display? Furthermore, if you wish to protect your LED display by using a limited current resistor, you may find the article How to design a 7 segment display with limited current resistor? “ helpful.

Type Of LED Display– Alphanumeric Display

An alphanumeric display is a complex 7-segment display specifically designed to display numbers 0-9 and English letters A-Z. Alphanumeric displays follow similar naming rules as 7-segment displays. In order to represent all English letters in both uppercase and lowercase, alphanumeric displays have three main designs for the emitting segments: 9-segment, 14-segment, and 16-segment configurations.

1. 9 emitting segment – Nine segment display
2. 14 emitting segment – Fourteen segment display
3. 16 emitting segment – Sixteen segment display.

     The most popular type of alphanumeric display is the sixteen-segment display. Similar to the 7-segment display, Opto Plus LED Corp. defines each emitting segment from A segment to P segment, including the DP point. For more detailed information, please refer to the data sheet for OPD-AS8020(1)LA-GW.

     If you would like to learn more about the internal structure and details of 16-segment displays, please refer to the article titled “Introduce each kind of 7-segment display, 16-segment display , and Internal structure!“.”If you are interested in understanding how 16-segment displays can be used to display Arabic numerals or the English alphabet, you can find information in the article titled “How to Representing Numbers and Letters in 7-segment and 16-segment LED display?.Furthermore, if you wish to protect your LED display using a limited current resistor, you can refer to the article titled “How to design a 7 segment display with limited current resistor?.

Type of LED Display: Icon/Bar Display

   Using pictures to display information is a very common application in home appliance products. Additionally, using a light bar to indicate progress is a simple and intuitive method. The advantage of using pictures and bars is that they can overcome language barriers and be understood worldwide.

　　Below are two example products that incorporate icon (pictures), bar, and 7-segment display: OPS-V32 and OPS-B500LA-UT-GW. The OPS-V32 is a typical custom display that combines a 7-segment display, icons (pictures), and a bar for customer display purposes. The OPS-B500LA-UT-GW can be connected to multiple displays to meet customer requirements.

OPS-V32

Type of LED Display: Mix-Type Display

Most mixed-type displays are customized to meet specific customer requirements, which may include large sizes, irregular shapes, small sizes, or thin profiles. A typical example of a mixed-type display is the dashboard display used in the Gogoro 2 Plus, which incorporates various functions to enhance the dashboard’s fashion, availability, functionality, colorfulness, and dynamic performance.

1. Large-sized and irregularly-shaped design.
2. An oversized 7-segment display to indicate the motorcycle’s speed.
3. Function pictures to display indicators such as direction lights, ABS, IOS, and more.
4. A bar to indicate the battery level.
5. RGB color ambient lighting for enhanced visual effects.

Type Of LED Display– Dot Matrix Display

LED dot matrix displays use individual emitting dots to display pictures or letters in various languages. They can be classified into two categories: displays for limited information and displays for any information. Please refer to the following introduction for more details:

Dot Matrix Display– To Display Limited Information

The most typical application of dot matrix LED displays is as numbering indicators for traffic lights. These displays are specifically designed to show limited information. For instance, the top light is designed to display only two yellow numbers for countdown purposes, while the red figure represents a prohibition against walking. When the top light is in countdown mode, the bottom light displays a walking green figure. These displays utilize monochrome LEDs to emit light and perform the dot matrix function for displaying limited information. They are commonly used for larger applications and employ DIP/THT monochrome LED lamps or SMD LEDs to achieve the dot matrix function. This type of display is cost-effective.

Dot Matrix Display– Can Display Any Information

Most mono-color or full-color moving signs belong to this type of display. The photos below show the LED moving sign structure made by 96 pieces of 8×8 LED dot matrix display (OPD-M58810W-GW).

　If you want to learn more about the internal structure and details of a dot matrix display, please refer to the article titled “Introduce dot matrix display’s name, type, internal structure, and application scene” If you are interested in how dot matrix displays convey information such as Arabic numerals and the English alphabet, it is worth noting that for the English alphabet or Arabic numerals, a minimum of a 3×5 dot matrix is required, but the most popular format is a 5×7 dot matrix per character. Additionally, for Traditional Chinese characters, a minimum of a 16×16 dot matrix is needed, while more detailed representations can be achieved with a 64×64 dot matrix. For a comprehensive explanation of how dot matrix displays render digits, English letters, and pixelated graphics, please refer to the article titled Explain how dot matrix display digits, English letter, and pixelated graphic?“

The Difference Between LCD Display, LED Display, OLED ,Mini-LED & Micro-LED.

　　There are two mainstream displays in the market: LCD display and LED display. LCD technology is commonly used in TVs and screens to convey complex information. Traditional LED displays, such as 7-segment LED displays and dot matrix LED displays, are widely used in home appliances and dashboard displays to show simple information like digits or icons. LED displays made with OLED, Mini-LED, and Micro-LED technologies have an advantage over LCD displays in terms of brightness and contrast when expressing complex information. However, LCD displays are generally cheaper than these LED displays due to more mature mass production technology.

　　 Traditional LED displays, OLED, Mini-LED, and Micro-LED are all made using similar technologies but differ in scale and color mixing methods. In this article, we will explore these aspects and provide explanations from these two perspectives.

Use a proportion chart to understand the major differences between traditional LED displays, Mini-LED, and Micro-LED.

　　The basic idea is to use single-color chips in an area to display all information and pictures. We will use the OPTO PLUS Standard dot matrix LED display OPD-M21610(1)LR-GW as an example to explain the difference between traditional LED displays and Mini-LED/Micro-LED displays.

　　The size of the dot and the spacing between the dots in an LED display are usually referred to as dot diameter and pitch, while for Mini-LED/Micro-LED/LCD displays, they are referred to as pixels and pixel pitch. One main difference between LED displays and Mini-LED/Micro-LED or LCD displays is the size of the dot. In the case of OPD-M21610(1)LR-GW, the 12 x 12 Dot Matrix LED display consists of 144 dots with a dot diameter of 1.9mm and a pitch of 2.54mm. The outline dimensions and a GIF showing its illumination are provided below.

　　As mentioned earlier, the major difference between LED displays and Mini-LED/Micro-LED displays lies in their scale. The following table and picture illustrate the difference in size.

　　 In order to demonstrate the difference in scale between these displays, we have arranged three displays side by side in the following picture to show the variation in size.

The Advantage to Use MicroLED/ MiniLED/ OLED Display To Replace LCD display

1. The smaller the pixel, the better the performance in terms of high-resolution display. Therefore, MicroLED, MiniLED, and OLED displays can achieve better resolution than LCD displays.
2. MicroLED, MiniLED, and OLED displays emit their own light, while LCD displays utilize a backlight through a light-conducting board to produce different colors. As a result, MicroLED/MiniLED displays can react quickly and offer better color contrast compared to LCD displays. Achieving true dark is challenging for LCD displays. Conversely, the self-emitting light characteristic of MicroLED/MiniLED/OLED displays enables easier attainment of true dark and better image quality.
3. MicroLED, MiniLED, and OLED displays are more energy-efficient than LCD displays.
4. However, the yield rate for MicroLED and MiniLED production is still low, making mass production challenging. Additionally, the price of these technologies remains too high for the market.