Optical encoders are used for accurate measurement of displacements which are either angular or linear. Optical encoders are referred as an electro mechanical piece of equipment which produces digital output for the displacement of the angular position of the input shaft. Optical encoders are widely used as position sensors since 1970. The industries which use them most are industrial machines such as printers, CNC machine types of equipment and some special kind of robots. In the past, there were inductors used for the positioning processes but due to their high cost, bulk and weight which overshadow their dependability and strength they were discarded of usage when optical encoder came into existence. But nowadays a new technology which is known as inductor encoder or in short “incoder” is giving the optical encoder a tough fight for holding the market share.
What does encoder do?
A primary function of an encoder is to alter positions or motions to an electrical signal normally a digital code which can be easily read by the electrical devices. In simple words, the encoder is a device which encodes signals in such a way so that they interpreted by the electrical devices. Electrical encoders are different than those of shaft encoder, angle encoders, angle sensors, etc. although many times they are confused with each other due to similar names. So it is advisable to the clients that before buying any encoders they should acquire the knowledge about the required one.
Encoders used for positioning purposes are mainly taken care of two types of motion linear and rotational. One of the major features of these kinds of encoders is they can measure the increase or decrease in the displacement of the shaft. In case of a simple absolute rotary encoder the information of the displacement is recorded just after the power-up that means the reading on the meter only changes while there is a displacement. Some configurations are come with an inbuilt reference mark for the encoder to judge whether the dislocation is incremental or decremented. Many industries like robotics, automated systems, etc are willing to go for types of equipment which can be calibrated before functioning so that the encoders can be told from where to mark the displacement. Nearly all incremental encoders have two type of electrical output A and B pulses. Rotation is recognized by the pulse which leads another one. But in case of absolute encoders output is calculated by Synchronous Serial Interface or S.S.I.; S.S.I. is a digital protocol which interacts by showing numerous bit values which point out the reading as absolute position.
Functioning of optical encoder
Whereas many positioning encoders use their own method to judge the distance traversed optical encoders use light for the same purpose. Within the encoder, a light source shoots out a beam of light by an optical disk. This beam of light is studied by an optical detector which seeks out the path of the light. Now if the light is broken off or doesn’t get interrupted in both cases the detector creates an equivalent electrical signal which is used further by display decoder to show the measurements. In the optical disk their several markings which are used to gauge the angle or motion. The markings are separated by small distances which are measured up to microns, i.e. 10-6 meter. That is why optical encoders can measure with high precision.
Working on optical disk and sensor in the encoder
Normally a packaged shaft encoder model is used in various industries. In this model, the shaft moves along in a bearing assembly. This shaft also holds the optical disk. Optical disk and optical detectors have a direct connection. As a matter of electrical components, a multicore cable is used for the connection which offers DC power in addition to conveying the output data. Due to this electrical operations, optical encoders are used for precise and representable output. On top of that, the electrical machinery is widely accessible in the market which and is easy to install.
Advantages of optical encoders
In the account of its’ high precision operations, optical encoders are mainly used in such places where a minimal amount difference between the practical and the theoretical positions can make the huge effect as a whole. Common examples of such industries are robotics, automated systems, etc. The main advantages of optical encoders’ machinery are –
- Optical and digital technology: Use of optics makes the encoder accurate, and digital output decoders eliminate the possibility of human error in measuring.
- Non-mechanical elements: Usage of non-mechanical components makes the encoders fast and nearly automatic in working. Only the bearings are of the mechanical domain.
- IC technology: Integrated Circuits or IC chips make the size of the system small, so it acquires a little place for functioning which is a great deal.
- Non-magnetic goods: The items used in optical encoders are usually non-magnetic. So magnetization effect doesn’t interpose with readings.
With all the mentioned features of an optical encoder, it is clear that why people have accepted it with a wide welcome in no time!