The laser scanner is an optical distance sensor for flexible protection in hazardous areas.
Access protection, etc. are achieved through access control.
It scans in three ways, including:
- Single line scanning
- Grating scanning
- Full angle scanning
This is a long-distance bar code reading device, which is widely used because of its superior performance.
The scanning method of the laser scanner has three methods: single line scanning, grating scanning and full angle scanning.
The laser hand-held scanner is a single-line scan with a large depth of field, high scanning first reading rate and high precision, and the scanning width is not limited by the device opening width;
The horizontal laser scanner is a full-angle scanner, which is easy to operate.
The operator can manipulate the item with both hands, as long as the bar code symbol faces the scanner, regardless of its orientation, automatic scanning is possible.
Most of the supermarkets use this type of equipment.
When the user touches the power switch or the corresponding device to energize the scanner, the VLD emits a red laser beam that is expanded through the beam expander lens and reflected onto the surface of the oscillating mirror and reflect to the bar code to form a laser spot.
When the reflect mirror swings, according to the principle of optical reflection, the position of the laser spot on the bar code changes and the mirror continuously oscillates, then a red laser line is seen on the bar code, which is caused by the persistence of vision.
The surface of the bar code is rough and reflected by the laser spot on the bar code.
The intensity of the reflection of the bars and air is different.
The diffusely reflected light is incident on the mirror, and then reflected by the mirror to the concentrator. The concentrator collects the light, and the stray natural light is filtered by the filter to enter the photodiode, and the photoelectric sensing signal is generated, and then amplified. The shaping is decoded into useful information and transmitted to the host.