“Light-emitting diodes arranged in a matrix form a dot matrix display. The ip68 led strip manufacturer says it is commonly used to display the time, temperature, news updates and more on digital billboards. Dot matrix displays are manufactured in a variety of sizes, such as 5×7, 8×9, 128×16, 128×32, and 128×64, where the numbers represent rows and columns of leds respectively.
Leds can be arranged in matrix mode in one of two ways: row anode-row cathode or row cathode-row anode. In the row anode-column cathode pattern, the entire row is the anode and all the columns act as the cathode, and vice versa in the row anode-column anode pattern. LED wafers stick to the bottom of the segment and glow when energized. Interestingly, the 35 leds are controlled by using a combination of 14 pins. Conductor tracks are laid throughout the circuit board to power each LED. Let’s take a closer look at how dot matrix displays work.
Dot matrix display: The Image01 shows the front of the 5 x 7 dot matrix display. A total of 35 leds are visible as dots on the front of the dot-matrix display. When their respective terminals are energized, the LED lights up.
Pin design: The back of the display displays the built-in track and pin. A total of 14 pins are used as terminals for 35 leds. Pin numbers vary by manufacturer. In this version of the dot matrix display, 13, 3, 4, 11, 10, and 6 are the pin terminals for the columns, and the rest are the rows.
LED segments and wafers
LED segment: After trimming the plastic edges, the 3-D structure of the LED points is distinctly visible. The dots are shaped like a funnel and are called LED segments. The LED wafer is fixed at the bottom of the LED segment. When an LED chip is energized, it emits light. The light passes through a funnel-shaped section that acts as a diffuser and illuminates the point. All LED sections are mounted on the frame with the help of plastic molding. It is a tough plastic molding that acts as a protective case by protecting the dot matrix display from dust, moisture, etc.
LED wafers: The tiny shiny gold material shown in Figure 04 is an LED wafer. It’s a tiny LED that’s difficult to spot with the naked eye.
LED terminals and slicing
LED terminal: The LED terminal can be seen after the segment is removed. The terminal supplies power to the LED.
Slicing: After removing all LED segments from their respective positions, cut the device in half. The two halves have mechanical locking devices that keep the assembly intact.
Panel and command track
Base plate: After cutting the device in half, a full view of the base plate with all the LED terminals can be seen. The LED segment that houses all 35 LED terminals is shown in Figure 07. In addition, two holes were cut into the panel to help with mechanical locking (marked inside the red rectangle)
Upper panel: The upper panel holds the LED segment tightly. LED segments are placed in these holes to form a matrix display pattern. These holes with LED segments are installed in curves carved into the bottom plate. The plastic fasteners for the upper panel are circled in Figure 08.
Conductor tracks: The tracks that connect the LED to its respective terminals are shown above 09. It is through these internal conductive rails that the leads are connected to each other. Rows and columns of leads are also visible, respectively. Some tracks are not visible in the image because they were damaged when the equipment was being excavated.”