By incorporating a laser source and detector array on the same chip, engineers at MicroE Systems have produced an optical digital encoder they claim is the world's smallest (6 mm square by 4 mm high) at a cost that will allow their use in mass production products, such as printers and copiers, as well as stepper motors.
The ChipEncoder™ uses a vertical cavity surface emitting laser (VCSEL) to generate a precise beam to reflect off a moving microetched scale onto a detector array beside the laser on the same hybrid circuit—determining position or velocity. The reflected beam is diffracted, creating a wide region of interference, within which the detector operates. This large interference zone enables wide tolerances so that no alignment is necessary after final assembly, says William Manning, marcom manager. Four factory pre-set resolutions (interpolation levels) range from 3,300 to 160,000 counts/revolution and 100 to 1,000 counts/millimeter. Engineers choose a VCSEL for its longer life and better performance compared to more common edge-emitting lasers.
The same chip-scale encoder package can be used with a linear or rotary reflective scale, with a built-in index mark, which increases production volume and helps drive down costs (in OEM quantities, the encoder's price is $49). The encoder produces a three-channel differential output with reference pulse for home-position determination. Cost is also held down by specifying one of four interpolation methods as opposed to making them integer selectable as on MicroE Systems more precise but larger, industrial-shielded programmable encoders.
As a non-contact, optical device, the ChipEncoder has zero wear, backlash, and hysteresis. The surface-mount package is compatible with automated manufacturing equipment, including pick-and-place and solder-reflow systems.
System on a chip: The 6 mm2x4mm high
ChipEncoder allows motion control to fit in tight volumes. It is low
costs, due in part to the same device being suitable for linear and
rotaryconfigurations, which facilitates use in such products as office
equipment printers and copiers.
Truchard will be presented the award at the 2014 Golden Mousetrap Awards ceremony during the co-located events Pacific Design & Manufacturing, MD&M West, WestPack, PLASTEC West, Electronics West, ATX West, and AeroCon.
Robots that walk have come a long way from simple barebones walking machines or pairs of legs without an upper body and head. Much of the research these days focuses on making more humanoid robots. But they are not all created equal.
The IEEE Computer Society has named the top 10 trends for 2014. You can expect the convergence of cloud computing and mobile devices, advances in health care data and devices, as well as privacy issues in social media to make the headlines. And 3D printing came out of nowhere to make a big splash.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.