Core Reasons Why LiDAR Windows Require Ultrasonic Cleaning

Contaminants: Any minor contamination on the window—such as fingerprints, dust, oil, or polishing wax—can have severe consequences. For the transmitting window, contaminants can deform the laser beam and attenuate its energy, leading to measurement inaccuracies. For the receiving window, they can cause blurry imaging, reduced contrast, noise, or even data loss. Ultimately, this degrades the overall performance of the LiDAR system and may render it inoperable.

Conventional Methods Are Ineffective: During processing and handling, the windows become contaminated with various stubborn substances. Manual wiping is not only inefficient but also risks scratching the surface or damaging the delicate anti-reflective (AR) coating. Standard cleaning methods also fail to effectively remove contaminants from the tiny wedge angles or complex structures on the window.

Advantages of Ultrasonic Cleaning: This technique utilizes high‑frequency sound waves to generate a “cavitation effect” in the liquid. Countless microscopic bubbles are continuously formed and then violently collapse, producing powerful impact forces that can penetrate microscopic crevices and thoroughly dislodge contaminants—without damaging the workpiece surface. This ensures both thoroughness and consistency in cleaning.

For cleaning high‑precision optical components such as LiDAR windows, Weguet VGT‑1309FH is a fully automatic optical ultrasonic cleaning machine that integrates cleaning and drying. It is primarily used in the optics industry for cleaning precision components that demand extremely high cleanliness, including shutters, infrared blocking filters, various optical filters, prisms, and beam splitters. The core value of this equipment lies in its highly automated process, which delivers stable, efficient batch cleaning, ensuring that products achieve an exceptionally high surface cleanliness before critical processes such as coating.

The equipment is controlled by a PLC (programmable logic controller) for fully automatic operation. A complete cleaning cycle typically includes the following steps:

1. Automatic Loading: The operator places the basket containing the workpieces onto the loading conveyor; after sensor positioning, the motor automatically transfers the basket into the machine.

2. Organic Solvent Cleaning: The workpieces first enter an organic solvent (e.g., dichloromethane) cleaning tank for multiple ultrasonic cleaning stages to remove stubborn oils and organic contaminants.

3. Drip‑off: After solvent cleaning, the workpieces are held in a drip tank to allow residual solvent on the surface to drain naturally.

4. Pure Water Rinsing: Subsequently, the workpieces enter pure water rinsing tanks for multiple ultrasonic rinsing stages, thoroughly removing any remaining detergent and ionic contaminants.

5. IPA Dehydration: After rinsing, the workpieces undergo multiple dehydration treatments in isopropyl alcohol (IPA). By utilizing IPA’s miscibility with water, this step effectively removes surface moisture.

6. Hot‑Air Drying System: Hot‑air drying is the final step in the drying process, aimed at completely removing trace moisture from the workpiece surface. In a sealed drying tank, circulating clean hot air thoroughly dries the workpieces. To prevent secondary contamination—i.e., to stop hot workpieces from attracting airborne dust—the equipment incorporates an FFU (Fan Filter Unit) system integrated directly above the drying tank. This unit blows clean air downward, creating a positive‑pressure (or negative‑pressure) environment that effectively isolates the interior from external airborne particles.

Key Technical Systems and Features

The Weguet VGT‑1309FH fully automatic optical ultrasonic cleaning machine integrates several precision technical systems that collectively ensure outstanding cleaning performance:

• Ultrasonic System: The core of the equipment uses a fourth‑generation ultrasonic generator with an efficiency of up to 95%. The generator incorporates a built‑in microcontroller, enabling one‑to‑one precise control for each cleaning tank, ensuring that the ultrasonic power is stable and adjustable (0–100%). The system typically operates at high frequencies such as 40 kHz and 68 kHz, and is equipped with an optoelectronic signal display for ultrasonic intensity, facilitating easy monitoring of the cleaning status.

• Circulation Filtration System: Each cleaning tank is equipped with an independent circulation filtration system. The cleaning fluid is circulated through a “mother‑tank‑to‑sub‑tank” method: a pump draws the liquid from the reservoir, passes it through a filter, and returns it to the cleaning tank. This achieves dynamic circulation and continuous purification of the cleaning solution. The system includes a removable strainer screen before the pump, and a filter and pressure gauge after the pump, allowing convenient monitoring and timely replacement or cleaning of the filters.

• Automatic Constant‑Temperature System: Each cleaning tank has its own independent temperature control system, with a temperature range from room temperature (RT) to 100 °C. Temperature sensors precisely regulate the cleaning fluid temperature, ensuring that the cleaning agents work at their optimal activity temperature, thereby guaranteeing consistent cleaning results.