Reticles Information

Reticles Information

Reticles are circular, transparent glass elements with a system of lines, dots, circles, or crosshairs for fine measurement or alignment in sighting applications. Reticles are used in sighting devices such as telescopes, microscopes, telescopic sights, and oscilloscope screens. Most reticle designs are etched, holographic, or made from wire. Etched reticles may have floating elements that do not cross the reticle itself. These optical devices are suitable for ballistics and range estimation applications. Holographic reticles are illuminated by a laser diode to produce three-dimensional (3D) images. Wire reticles feature lines that cross the reticle completely. The shapes or patterns are limited by the thickness of the wire, which is usually black or silver. 

Reticles may be positioned at either a scope’s front focal plane or its rear focal plane. With fixed power scopes, the location is not critical. With variable power scopes, however, the location determines whether the reticle remains at a constant size to either the target (front plane) or user (rear plane). The first focal plane is associated with the objective lens and the second focal plane is associated with the ocular lens. Sometimes, sighting devices are referred to as either first focal plane reticles and second focal plane reticles. Although front-plane reticles provide greater durability, many variable power scopes feature a rear focal plane design.  

Product Specifications

Product specifications for reticles include diameter or side length, line width or graduations, and thickness. Centering, the displacement error of the reticle design from the center, is also important to consider. Typically, reticle suppliers categorize products by type, which is based upon the shape or pattern. There are many different types or styles of reticles. Some have patterns that consist of concentric circles. Others have crossed lines or crosshairs. Choices may include grid patterns, single or multiple horizontal lines, pinwheels, and protractors. Reticles with scales, spots or dots, and single or multiple vertical lines are also available. Whipple reticles use a grid pattern with a single grid that is further divided into a varying grid.    

Specialized Reticles

Specialized reticles are available for ballistics, firearms, and gun sighting applications. The tactical military reticle (TMR) is a variation of the Mil Dot design. It features vertical and horizontal crosshairs with tick marks or lines that are variously sized and spaced. Special purpose reticles are specialized sighting devices that combine the features of range finding reticles with other designs, grids, or patterns. Microscope reticles for laboratory or scientific application are also available.

• MICRO:Ultrapure Materials-Reticles by James Wiley, p.35 (April '99)
  , the electric field from the induced charge may break down the air and cause an ESD event. In semiconductor manufacturing the effects of static charge are particularly critical in the photolithography area. The photo process involves step-and-repeat operations using reticles. A damaged reticle can result...
• MICRO: Product Handling and Automation - Fosnight (May 2000)
  and William Fosnight, Joshua Shenk, and Rick Zemen, Increasing emphasis is being placed on reticles and their importance in advanced semiconductor manufacturing. Most reticle patterns are sized for 4x reduction. This means that the patterns on a mask are four times larger than the patterns imaged...
• MICRO: Behind the mask - Peterson (September 2000)
  . To illustrate the importance of connectivity in the RQM methodology, case study 2 discusses the impact of reticle defects on yield, focusing on translation software that links the defect locations on reticles to those on product wafers. Using a Reticle-Sampling Plan. MICRO: Behind the mask - Peterson (September...