BRAND IDENTITY NAMEPLATES	MEMBRANE SWITCHES	VALUE-ADDED ASSEMBLIES
LABELS	INJECTION MOLDING	DIE-CUT COMPONENTS
GRAPHIC OVERLAYS	COMPRESSION MOLDING	OPTICAL ENCODERS
TOUCH SCREENS	PLASTIC/ELASTOMER DECORATING	LARGE FORMAT GRAPHICS

OPTICAL ENCODERS

Optical encoders measure motion, such as position, velocity, and acceleration in a variety of equipment and machinery. Disk encoders measure rotation and line encoders measure linear motion.

GM Nameplate creates film and glass encoders photographically by contact exposure of photographic film directly from chrome-on-glass or emulsion-on-film masters. Metal encoders are chemically or laser etched.

Materials
Metal, glass and film are the most common encoder materials. Glass is highly durable and capable of the highest resolution encoder, but also the most expensive. Metal encoders are also highly durable but usually low resolution. Film encoders, the most common and least expensive, feature high resolution and modest durability.

Resolution and Masters
Encoder resolutions range from 20 to 550 lines per inch (LPI) with line and space widths from .025" to .00091". For low to middle resolution encoders (20-400 LPI), glass masters can produce a maximum image size of 22.8x31.5 inches. Standard film masters can produce maximum image sizes of 23x35 inches. With our special imaging equipment, GM Nameplate can produce masters up to 48x80 inches. Glass is the preferred material for masters, being both dimensionally stable and clear. Because glass masters represent a significant cost, film masters are often used during prototyping. Proofs created from film verify the master before production.

Fabrication and Tolerances
Encoders are fabricated with Class-A tooling and optically controlled punch presses to achieve the best tolerances and image registration. Optically punched holes serve as the center mounting holes for encoder disks and as Class-A tooling registration holes. With a limit of .472" diameter, registration holes can be punched at the same diameter as the center hole to eliminate setting up two or more punches. Most affected by the fabrication process is the TOTAL INDICATED RUNOUT (TIR) of an encoder disk. With optical targets. TIR can be held to .002". Final shape and interior holes fabricated by Class-A tools will hold tolerances of plus/minus .005" and optically punched mounting holes plus/minus .001".


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