What is "linear scale"

linear scale, also known as raster ruler displacement sensor (sensor grating ruler), is using the optical principle of work of grating measuring feedback device. Grating ruler is often used in closed-loop servo system of nc machine tools, can be used for detection of linear displacement or angular displacement. The measurement of the output signal of digital pulse, with wide detection range, high precision, fast response characteristics. In the numerical control machine tool, for example, often used for cutting tool and workpiece coordinate, to observe and track feeding error, to play the role of a motion error compensation of cutting tool.

linear scale according to the methods and different optical principle, divided into transmission grating and reflection grating.

linear scale is made up of rod grating and the grating reading of the first two parts. General scale grating fixed on the machine fixed parts, grating reading head installed on the machine moving parts, indicating grating in a grating reading head. The picture on the right is shown in the structure of the grating ruler.

Raster detection device is a key part of the grating reading head, it consists of light source, convergent lens, grating, optoelectronic components and the adjusting mechanism, etc. Grating structure of reading head form a lot, according to the reading head structure characteristic and using occasion are divided into direct receive type reading head (or silicon photocell reading head, image reading, reading head, metal grating spectroscope type reflection type reading head).