The CONEX-LDS is a versatile electronic autocollimator with integrated controller used for non-contact alignment or high resolution angular measurements. Using advanced optics and electronics technology with simplified design, the CONEX-LDS offers a high level of reliability for demanding metrology and industrial applications. With convenient features like the integrated controller, eyepiece and mounting accessories, the CONEX-LDS enables quick convenient setups on-site or at the production floor. CONEX-LDS can be interfaced via USB or Ethernet for network communication.
This is a classical application for autocollimators. To obtain flatness measurements, the autocollimator beam is reflected off a mirror. By indexing the mirror along the beam path at known distances, linear position vs. the pitch angle is obtained and is used to determine vertical displacement.
In manufacturing environments or metrology applications that utilize dividing heads or rotation stages with mechanical or air bearings, the CONEX-LDS is a very useful tool to verify the wobble of the bearings. In the manufacture of ball, thrust or air bearings, particularly those with large diameters, in-process or final verification of wobble specifications can be accomplished with the CONEX-LDS. In both cases, a simple mirror mounted perpendicular to the rotation axis with the CONEX-LDS beam coincident to it, will provide high precision measurements of wobble that will characterize the condition of the bearing. The results could indicate the need for maintenance, repair or rework. The graph on the right illustrates a typical result of a wobble test of a bearing. Using the same CONEX-LDS setup, but with a precision ball fixture rather than a mirror, it is possible to determine the axial eccentricity of a bearing.
Pitch and Yaw deviations during motion increase positioning errors due to the Abbe effect, especially at a longer distance between the sample and the feedback encoder. With the CONEX-LDS autocollimator, this type of error can be accurately identified and used to calculate true position. Pitch and yaw can be measured concurrently using a simple flat mirror. In addition, these angular measurements can be used to derive the flatness and straightness deviations of the linear bearing.
The time required for settling into a position is an important parameter in high-accuracy, highthroughput applications like semiconductor inspection. Fast settling times result in processes to be performed very quickly, thus increasing productivity. In this case the CONEX-LDS autocollimator is used to measure the angular displacement at all stage positions, according to the control parameters. The dynamic measurements reflect the stage performance at the given situation. Using Fourier analysis of the same data enables understanding of the stage's resonances.
Rotation stage accuracy can be measured using a precisely calibrated multifaceted mirror. The CONEX-LDS autocollimator measures the angular difference between the stage rotation and index of the calibrated standard. Absolute accuracy is measured directly, taking the index error and hysteresis into account. The measurement accuracy is better than 1 µrad.