Renishaw's optical encoder history

As Renishaw grew its metrology business in the early 1980s, it recognised the increasing importance of high performance position encoders in the CMM and machine tool markets and, in response to this trend, Renishaw Research formed an Optical Projects Department in 1984. Focussing mainly on the CMM and metrology markets, the first prototype RG optical scale was developed in 1988 and this was closely followed by the first optical readhead, the RGH1, which was first supplied to customers in 1989. Further technology developed at this time included digital interpolation within the readhead, the electrograting integrated fringe detector and built-in set-up LEDs for easy encoder installation (without requiring any external set-up or diagnostic tools). This led to the introduction of the RGH22 readhead in 1996 and the highly popular RGH24 readhead in 1999.

Significant advances in laser ablation for scale production led to the first high performance rotary ring scale, the RESR, in 2002. The core filtering optics technology in the RGH2 encoder range was enhanced with powerful built-in signal processing to produce the SiGNUM™ readhead range in 2004 and the super-compact TONiC™ encoder series in 2008, delivering improved metrology performance in a substantially smaller readhead.

In 2009 Renishaw broke new ground with the introduction of RESOLUTE™, the world's first true-absolute fine-pitch single track optical encoder, which delivered absolute position measurement with low Sub-Divisional Error and jitter at resolutions down to 1 nm and at linear speeds of up to 100 m/s.

Miniaturization of electronics and optics allowed the introduction in 2014 of the ATOM™ encoder series, which provides leading-edge signal stability, dirt immunity and reliability in a miniature encoder package. These advances also contributed to new variants of the TONiC encoder series: the high performance digital all-in-one VIONiC™ readhead in 2016 and the versatile and easy-to-install QUANTiC™ encoder launched in 2018.

2021 saw the introduction of an exciting new product range – the FORTiS™ enclosed linear absolute encoder series combines the industry-proven technology of the RESOLUTE absolute encoder system with enhanced sealing and an innovative non-contact design to deliver reliable high-performance position measurement with easy installation, excellent vibration resistance, superior repeatability and reduced hysteresis compared to conventional enclosed encoder designs.

Now in its fourth decade, Renishaw's encoder business has grown from strength-to-strength with high volume sales across multiple product lines for an increasing range of demanding markets and applications such as robotics, automation, motion control, metrology, electronics manufacturing and flat panel display manufacturing. Renishaw encoders are now established at the forefront of the motion control industry, offering manufacturers of the world's highest specification machines unparalleled service, quality and performance.