Laser ranging device and automatic cleaning device

A laser ranging device, comprising:

• an encoded chassis comprising a rotary bin and a plurality of ranging teeth disposed at intervals on the periphery of the rotary bin;
• a rotary disc that is mounted within the encoded chassis and is rotatable within the rotary bin when the rotary disc is driven;
• and
• a first barrier ring disposed on the encoded chassis and located at the periphery of the plurality of ranging teeth.

A method of manufacturing a laser ranging device, comprising:

• providing an encoded chassis that comprises a rotary bin and a plurality of ranging teeth disposed at intervals on the periphery of the rotary bin;
• providing a rotary disc that is mounted within the encoded chassis and is rotatable within the rotary bin when the rotary disc is driven;
• and
• providing a first barrier ring disposed on the rotary disc;
• wherein the first barrier ring is disposed at the edge of the bottom surface of the rotary disc and is located at the periphery of the ranging teeth after the rotary disc is mounted to the encoded chassis.