Technical Background:

The Anker smart door lock employs contactless palm vein recognition technology (based on 850nm infrared light), with the following advantages:

• High Security: Vein patterns are located beneath the skin, making them difficult to forge.

• Swift Response: 0.5-second rapid identification, compatible with multi-modal biometric recognition (e.g., fingerprint, facial).

• Adaptive Optimization: Algorithms are iteratively updated to enhance stability in complex environments.

Phenomena

1.  Children’s Palms:

• For children under the age of 7, the failure rate for registration or recognition is higher, and the palm vein imaging may be incomplete.

2. Direct Exposure to Intense Light:

• Recognition accuracy significantly decreases in direct sunlight or under strong artificial light sources.

3. Dirty Palms (e.g., mud, oil paint, etc.):

• The recognition success rate drops when the palm surface has heavy contaminants.

• Vein patterns appear blurred in imaging.

4. Incorrect Posture:

• Failure to register or recognize due to the palm being too close/far from the sensor or tilted at an improper angle.

Root Causes

1. Children’s Palms:

• Size: Small palm dimensions cause insufficient coverage of the vein area when placed <4 cm from the sensor.

• Vein Depth: Shallow vein patterns result in inadequate image contrast.

2. Direct Intense Light:

• Interference: External light disrupts infrared reflection paths, causing excessive noise or overexposure in images.

• Sensor Overload: The sensor fails to capture clear vein patterns due to light intensity exceeding its tolerance.

3. Dirty Palms (e.g., mud, oil paint, etc.):

• Obstruction: Dirt or substances like oil paint block infrared light penetration, distorting vein imaging.

• Abnormal Reflection: Contaminants alter surface reflectivity, degrading image quality.

4. Incorrect Posture:

• Distance: Extreme distances (>15 cm or <4 cm) lead to blurred or incomplete imaging.

• Angle: Rotation exceeding ±15° misaligns veins with the sensor’s scanning area.

Solutions and Operational Guidelines

1. Children’s Palms (aged under 7):

• Registration Distance: Guide children to place their palms flat and centered over the sensor at 4–6 cm (adults: 10–15 cm).

• Retry Process: If initial registration fails, reposition the palm and attempt again.

2. Mitigating Intense Light Interference:

• Shade the Sensor: Block direct sunlight or strong light sources using your body or objects; ensure uniform illumination in indoor/outdoor environments.

• Disable Strong Light Sources: Turn off flashlights, cameras, or other artificial light sources to avoid reflection interference.

3. Cleaning the Palm:

• Preparation: Thoroughly remove contaminants (e.g., mud, oil, etc.) using clean water or neutral detergent. Wipe the palm dry to ensure no moisture remains.

• Verification: Confirm no residues (e.g., paint, makeup, etc.) remain on the palm surface.

4. Adjusting Posture:

• Standard Distance: Hold the palm flat, perpendicular to the sensor, maintaining a distance of 10–15 cm.

• Alignment: Rotate the palm to align vein patterns with the sensor’s scanning zone, keeping the wrist suspended naturally.

Important Notes

• Light Conditions: Ambient light must be between 50–10,000 lux; avoid extreme darkness or brightness.

• Sensor Maintenance: Regularly clean the sensor surface with a soft cloth to prevent dust from degrading image quality.

• Palm State: Ensure the palm is dry and free of sweat before registration. The palm temperature is between 25–35°C. Avoid wearing gloves or jewelry.

• System Updates: Periodically check and update the lock’s firmware to access the latest algorithm improvements.

If you have any other questions about the FamilLock S3 Max, please don't hesitate to contact eufy Support Engineers for further assistance.