What makes Automatic De-icing and Defogging Cameras Crucial in Dynamic Environments

In autonomous vehicles and mobility platforms, perception, navigation, and uninterrupted operation depend on the image quality of embedded cameras. However, in real-world environments, camera lenses are subject to various natural effects, such as icing, frosting, and fog, which may impact the operation of vision-based systems.

In addition, after condensation forms on the lens surface, it can persist even as conditions change, affecting image capture.

To address this challenge, de-icing and defogging cameras integrate advanced lens heating technology as a proactive design solution. This prevents condensation before it forms, ensuring uninterrupted vision performance.

In this blog, we’ll take a closer look at how these cameras work and what makes them reliable in harsh environments.

What is a De-icing and Defogging Camera?

De-icing and defogging cameras come with a built-in heating element that generates heat by converting electrical energy into thermal energy. The generated heat will melt ice or frost on the camera lens when exposed to cold temperatures. The heating element will also prevent the formation of fog on the camera lens when environmental conditions change.

The lens heater input power supports continuous operation as well as manual or automatic on/off control. Additionally, the camera offers a range of power operating modes, which makes it efficient for use in power-constrained applications of embedded vision, including warehouse robots, service robots, and other autonomous robots.

How De-icing and Defogging Technology Works in Vision Systems

Typically, when the camera is exposed to two different temperatures in an interim, two things happen:

• Ice builds up directly on the camera lens in cold conditions.
• Condensation forms, creating a fog-like film, because of the ice formation across the lens surface in warm conditions.

This process occurs according to a physical principle known as the dew point temperature. It is the temperature at which the air is saturated with water vapour. At this point, the water vapor changes to liquid form when it touches any surface that is cooler than the air.

Rather than responding to fogging after it occurs, this lens heater-integrated embedded vision camera works proactively by continuously regulating the lens surface temperature to keep it above the ambient dew point at all times.

The diagram below illustrates the lens heating element and its control mechanism.

The microcontroller unit (MCU) continuously monitors the lens temperature. Using a pulse-width modulation (PWM) signal, it automatically adjusts the power delivered to the heating element to maintain the lens temperature.

The lens heater activates when the lens temperature drops below the dew point and automatically powers off once the dew point is reached.

Real-World Validation of De-icing and Defogging Camera

e-con Systems performed tests with its GMSL camera at different temperature ranges and power levels.

Here’s what this revealed:

Test 1 – Finding Dew Point

The camera was exposed to a 0°C chamber environment with the heater on and streaming on, while the ambient room temperature was 25.2°C. The lens heater temperature is adjusted to different temperatures to find the dew point and prevent condensation on the camera lens.

The camera was removed from the chamber, and the preview was checked for any condensation formation at different lens temperatures.

The figure below shows the condensation observations at 15°C and 20°C.

15°C-Condensation Occurred vs 20°C- No Condensation Occurred

The tables below show the condensation observation at different temperatures.

Lens Temperature	Condensation Observations
20°C	No
19°C	No
18°C	Yes
15°C	Yes

The dew point was 20°C, indicating that the lens heater should be maintained at 20°C when exposed to an environment at 0°C or lower to prevent fog or condensation.

Test 2 – Lens Heater On at 2 W for 0°C

The camera was first placed in a 0°C chamber environment with the heater activated, and live streaming began.

The time taken for the lens to reach 25.2°C, the room temperature, was measured. It took 11 to 12.5 minutes across three repeated trials at 2 W (8.13 V, 0.254 A) lens heater power.

The results indicate that 2 W of power is sufficient for recovery from 0°C exposure.

Test 3 – Continuous Lens Heater Operation at 2 W for 0°C

The camera was exposed to a 0°C chamber environment with both the heater and streaming enabled. The temperature of the lens heater was maintained at 20°C inside the chamber, with 2 W (8.13 V, 0.254 A) of power.

Upon removal from the chamber to ambient room temperature (25.2°C), the lens surface remained clear with no condensation, and the camera continued to capture clear images, as shown below.

Test 4 – Comparing 2 W vs 5.5 W Performance for −30°C

The camera was exposed to a −30°C chamber environment with the heater and streaming on. The lens heater consumed ~2 W (Voltage = 8.13 V, Current = 0.254 A)

The graph below shows that at 2 W, the camera lens struggled to overcome the extreme thermal gradient.

Again, the camera was exposed to a −30°C chamber environment with the heater and streaming on.

The lens heater power was increased to 5.5 W (12.4 V, 0.44 A), resulting in faster temperature recovery as shown in the graph below.

Test 5 – Time to Reach Dew Point (20°C) at Different Power Levels

The camera was exposed to a −30°C chamber environment with the heater and streaming enabled. The time to reach 20°C at different power input levels is listed in the table below.

Power Input	Time to 20°C
5.5 W	5 min
4.5 W	8 min
3.5 W	Not reached
2.0 W	Not reached

How to Select the Right Power Configuration

The data show that the GMSL2 camera with a lens heater reaches 20°C quickly from extreme cold (-30°C) at 5.5 W, whereas at 2.0 W, the heater cannot reach 20°C.

The lens heater can be set to operate continuously or controlled with on/off switching in either manual or automatic mode. The power can be adjusted, ranging from 2 W to 4 W or more, providing flexibility to balance thermal performance with energy efficiency in embedded vision applications.

In this case, at -30°C, the power should be >4.5W to reach a dew point, and then it can be switched to 2W mode to maintain the dew point temperature in the lens.

e-con Systems’ Cameras for Rugged Real-World Deployment

Since 2003, e-con Systems has been designing, developing, and manufacturing embedded vision solutions, from custom OEM cameras to complete ODM platforms. We integrate lens-heating technology into our embedded cameras to maintain clear, reliable imaging in harsh conditions.

Use our Camera Selector to find the right vision solution for your unique requirements – environmental and/or technical.

Have specific requirements? Please reach out to us at camerasolutions@e-consystems.com.

FAQs

1. Why are de-icing and defogging cameras important?De-icing and defogging cameras ensure that images are captured clearly in any environment. This is to ensure that vision-based applications like AMRs and robots work correctly by preventing the accumulation of ice and fog.

2. How does lens heating prevent fog and condensation?Lens heating keeps the lens surface temperature higher than the surrounding air’s dew point. This means that moisture in the air will not condense on the lens surface, and therefore fog will be avoided.

3. Can the lens heater be controlled based on application needs?
   Yes, the lens heater can generally be controlled, whether manually or automatically, in a continuous or intermittent on-off manner as required.

4. What power levels are required for effective de-icing and defogging?
   The power level varies depending on environmental conditions. For example, in moderate conditions (e.g., around 0°C), 2 W lower power is sufficient, whereas in extreme cold conditions (e.g., −30°C), 4.5 W of power or above is required to attain the dew point quickly; later, power can be reduced to maintain the temperature.

5. How does the automatic control of the lens heater work?
   The microcontroller in the lens heater continuously monitors the lens temperature and adjusts the heater via a pulse width modulation (PWM) signal. This will ensure that the lens is kept above the dew point while optimizing power consumption.