Quick answer
Hot spots are a frequent defect in LED displays, typically stemming from unstable manufacturing processes. They’re most commonly seen in seven-segment and dot matrix displays, appearing as visibly lighter areas on the display surface. Recognizing these defects helps prevent costly production errors.
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Common LED Display Defects: Hotspots
Hotspots are a common defect in LED displays, almost always caused by an unstable manufacturing process. This kind of problem is hard to spot, especially in small batches, but it often shows up during mass production. This makes it easy for defective products to be shipped to customers.
We see LED displays every day. For product designers, understanding common defects is key to preventing mistakes and reducing the high costs of fixing problems during mass production.
This article explains what a hotspot looks like and uses graphics to show two common examples for designers to learn from.
Visualizing Hotspots in LED Displays
Because it’s hard to get photos of hotspots (due to client intellectual property), this article uses a graphic to explain what they look like. The graphic is based on a real photo of a dual-digit, seven-segment display with a hotspot.
When a seven-segment display lights up, you can see the problem in the diagram above. The center of the segments is a lighter color, almost white, compared to the outer areas. This is what we call a hotspot. This defect makes the display look bad and causes a visible flaw.
Common Ways to Talk About Hotspots
The term hotspot is used most of the time. However, you might hear a few other phrases depending on the type of display:
－For a 7-segment display: Hotspot 7-segment
－For a dot matrix display: Hotspot dot matrix
－For an alphanumeric display (14- or 16-segment): Hotspot Alphanumeric or Hotspot 14-segment/16-segment
Examples of Hotspots
Hotspots are most common in two types of displays: 7-segment displays and dot matrix displays. Here are two examples:
Example 1: A single LED 7-segment display has hotspot issues within its own segments.
Example 2: An LED dot matrix display has hotspot issues in its individual dots.
Since hotspots are related to the manufacturing process, they almost never appear alone. When a hotspot happens, it usually affects the entire panel.
亮點(hotspot)範例[1]－雙八亮點(hotspot)問題
The image above shows a common example of hotspots in a dual-digit, seven-segment display. The OPD-D5630(1)LR-GWOPD-D5630(1)LR-GW is an LED display with two digits inside.Due to an unstable manufacturing process, the display in the photo has hotspots in every segment. You can see that the inside of each segment is a lighter, whiter color, while the outside is a deeper red. This difference makes the display look bad and is a clear visual defect.
Example 2: Hotspots in a Dot Matrix Display
The image above shows a common example of hotspots in a dot matrix display. The OPD-M35760LA-BW is a display with 5×7 square dots.
Due to an unstable manufacturing process, the dot matrix display in the photo has hotspots in every single dot. The center of each square dot has a clear white spot. This defect makes the display look uneven and causes a visible flaw.
Conclusion
Hotspots are a less-known defect in LED displays. When they happen, the display not only looks bad but can also cause problems for systems that use image recognition to read data from the display, leading to errors. This makes hotspots a defect that must be avoided.
Opto Plus has been specializing in LED displays for over 15 years. To prevent defects like uneven color, we focus on a stable manufacturing process and do a 100% manual inspection before every shipment. This ensures our products are consistently high quality.
If you have questions or are currently facing problems with uneven color in your products, please contact us for help.
Other Common LED Display Defects
Besides hotspots, here are two other common defects you might find in LED displays:
－Uneven Segment Color: This happens when different parts of the display, or different digits, have different colors or brightness levels. It makes the display look inconsistent and unappealing.
－Light Leakage: This is a problem where light escapes from a part of the display where it isn’t supposed to be, causing unwanted light around the segments. It can make the numbers or letters look blurry or messy.
FAQ
A hotspot is a common defect in LED displays. It’s usually caused by an unstable manufacturing process. It appears as a bright spot or area with uneven color, where the center of a segment is much lighter—sometimes even white—compared to the surrounding area.
Hotspots make an LED display look bad and cause a visible product defect. Since they usually show up during mass production, they are hard to spot and can easily get shipped to customers.
Hotspot issues can appear on many different LED displays. The article mentions two common examples:
－LED 7-segment displays: Where individual segments have hotspots.
－LED dot matrix displays: Where individual dots have hotspots.
No, they typically do not. Because hotspots are linked to the manufacturing process, they usually affect the entire display panel at once and almost never appear by themselves.
As a product designer, understanding this type of defect helps you avoid design mistakes. It’s also critical to choose a supplier that can consistently provide high-quality products. Fixing defects during mass production can be very expensive. At OPTO PLUS LED, we focus on stable manufacturing and perform a 100% manual inspection before shipping to ensure our products are high quality.
Yes. The article also mentions two other common LED display defects:
－Uneven segment color
－Light leakage