Grating Ruler

Grating ruler, also known as optical linear encoder,is a sensor that realizes high-precision displacement measurement using optical principles. It is commonly used to measure linear position, displacement and speed,and is applied in the closed-loop servo systems of CNC machine tools. Its measurement output signals are digital pulses, featuring a large detection range, high detection accuracy and fast response speed. According to different manufacturing methods and optical principles, grating rulers are divided into transmissive gratings and reflective gratings.

Common Specifications(Support professional customization)

Basic Structure of Grating Ruler

A grating ruler usually consists of two main parts:

1. Scale Grating (Fixed Part)

A glass or metal ruler with uniform engraved lines, where the spacing between engraved lines is extremely small(micron level).

2. Reading Head(Moving Part)

It contains a light source(LED), photoelectric sensor and signal processing circuit inside. It moves along the grating ruler with mechanical motion and reads position information in real time.

Working Principle of Grating Ruler

In simple terms, the core of the grating ruler is based on an optical principle: when light passes through regular engraved lines, it will produce periodic changes(similar to"light and dark fringes"). The process can be understood as follows:

1. The light source irradiates the grating engraved lines;

2. The light is "cut" by the engraved lines into periodic light and dark signals;

3. The photoelectric sensor receives these changes;

4. The system converts them into electrical signals (pulses or digital quantities);

5. Finally, the displacement, position or speed is calculated.

Features of Grating Ruler

1. Ultra-high Precision: The resolution can reach micron or even nanometer level,and it is widely used in high-end CNC equipment.

2. Strong Real-time Feedback Capability: It can continuously output position signals and is suitable for closed-loop control systems.

3. Non-contact Measurement: It has no mechanical wear,long service life and high stability.

4. Good Anti-interference Ability: Optical measurement is not affected by electromagnetic interference,and the signal is stable and reliable.

Application Fields

Grating rulers are used in almost all equipment that "requires precise movement", such as:

1. CNC Machine Tools: Position closed-loop control

2. Automation Equipment: Precision positioning

3. Semiconductor Equipment: Nanoscale positioning

4. Testing Instruments: High-precision measurement systems

5. Robotics: Linear axis position feedback

Dongguan Dafan Optical Technology Co., Ltd.(DFOPTIX) was founded in 2018, its headquarters located in Dongguan City, Guangdong Province, China. DFOPIX is a system-level calibration solutions service provider with engineering culture as its cornerstone and technological innovation as its core.

Currently, DFOPTIX has nearly 150 employees, with R&D personnel consistently accounting for over 30% of the workforce each year — a professional team combining deep engineering expertise with sustained innovation capability.

DFOPTIX has established an advanced R&D and manufacturing base spanning nearly 20,000 square meters, equipped with high-standard precision workshops such as class-100 lithography workshop and class-1000 vacuum lamination workshop, as well as various well-equipped professional laboratories. It has also introduced internationally advanced manufacturing and testing equipment, systematically establishing an industry-leading R&D and manufacturing system.

DFOPTIX specializes in the R&D and manufacturing of a full category of calibration products — including integrated light-source calibration targets and LiDAR calibration boards, while also providing customized calibration product services tailored to customers’ requirements. To date, our company's products and solutions have been widely deployed across sectors including medical, semiconductor, robotics, consumer electronics, intelligent vehicles, aerospace, 3D scanning, and industrial automation. DFOPTIX has served over 3,000 clients, including several Fortune 500 companies.