Incremental Encoder is commonly used, and Absolute Encoder is used if there are strict requirements on position and zero position. Servo system should be analyzed in detail, depending on the application situation. Commonly used incremental encoder for speed measurement, which can be used for infinite accumulation measurement; Absolute encoder is used for position measurement, and the position is unique (single or multiple turns). Finally, it depends on the application situation and the purpose and requirements to be realized. Incremental Linear Encoders,Linear Optical Encoder,Linear Position Encoder,Encoder Bearing Tester Yuheng Optics Co., Ltd.(Changchun) , https://www.yhenoptics.com
Blu-ray Disc (BD) is one of the next-generation optical disc formats after DVD for storing high-quality audio and video and high-capacity data storage. Blu-ray discs are named because they use a blue laser beam with a wavelength of 405 nanometers (nm) to read and write (DVD uses a 650-nm wavelength red reader, and CD uses a 780-nm wavelength). A single-layer Blu-ray disc has a capacity of 25 or 27GB, enough to record a high-resolution video for up to 4 hours. For its true and false, we can actually look at the box. DVD only prints "Blu ray" on the envelope, and Blu-ray has the box, whether genuine or not.
For true and false blue light:
A friend who is very familiar with the DVD industry once told me that the real Blu-ray, the production line in Hong Kong, the production cost of a plate about 60 languages, 38 of the text is definitely false. There are also a lot of confiscated Blu-ray movies below this price, so then look down:
Look at the box: I mainly look at the "Blue ray" logo. The fake silver is very rough.
Look at the printing: The difference might not be very great if you look at the cover. Look at the words on the back cover. The false registration is very poor. There will be ghosting. The false basic printing seen on the market is very poor.
Look at the base: Blu-ray discs are between cyan and blue-purple, and DVD media are silver or gold.
Into the computer to read: VISTA can identify the capacity of the disc (XP as long as the installation can identify tools UDF 2.5 format can also be), 8.6GB below is definitely a DVD, Blu-ray's minimum capacity of 25GB.