TriAngle. Electronic Autocollimators for Precise Angle Measurement

Transcription

1 TriAngle Electronic Autocollimators for Precise Angle Measurement

2 Angle Measurement Solutions Contents Page TriAngle Angle Measurement Solutions 3 Operating Principle 4 TriAngle Product Range 5 Highly Flexible Angle Measurement Solutions TriAngle - The Most Versatile Electronic Autocollimator TriAngle UltraSpec - Ultra Precision Angle Measurement TriAngle HiSpeed - High Speed Angle Measurement TriAngle LASER - Measures at Low Reflectivity Customized TriAngle Solutions OptiAngle Software for TriAngle 11 The Complete Software Package for Angle Measurement Software Features und Functions Easy Integration of Customized Measurement Solutions OptiAngle Programming Interface (API) Measurement Applications 13 Typical TriAngle Measurement Applications Straightness Measurement Wedge Measurement Calibration of Index Tables and Rotary Encoders Technical Data and Order Information 17 Order Information TriAngle Delivery Kit Measurement Capabilities and Recommendations TriAngle Configurations Accessories 18 Opto-mechanical Accessories Order Information

3 Angle Measurement Solutions TriAngle Angle Measurement Solutions The TriAngle electronic autocollimators are non-contact optical test tools for the high-precision measurement of angular displacements of specular reflective surfaces and the accurate angular alignment of optical or mechanical parts. TriAngle autocollimators are available in six application specific variants: TriAngle the most versatile electronic autocollimator for standard applications TriAngle UltraSpec enhanced sensor technology for highest resolution and ultra precise measurement results TriAngle HiSpeed for high speed angular measurements TriAngle LASER for small or low-reflectivity samples or long distance measurements TriAngle Focus employs focusing objective tubes for contact-free optical radius measurements TriAngle NIR are used for applications that require measurements at the NIR range 3

4 Angle Measurement Solutions TriAngle autocollimators have a versatile modular design which allows the fitting of a large selection of objective tubes, different sensors, reticles and light sources. With objective tubes of different focal lengths and apertures the optimum measurement solution regarding angle resolution and measurement range is easily found. The digital camera interface enables the use of a notebook or desktop PC, or a mobile touch-screen display unit for measurements in the field. The comprehensive OptiAngle software records, analyzes, stores and reports the measurement results for later reference. A comprehensive set of predefined measurement programs cover all standard applications. It includes Absolute and relative angle measurements of mirror surfaces Absolute and relative angle measurements of collimated sources Wedge angle measurement 90 prism errors 45 prism errors Wobble (run-out) measurement of rotating samples d Image Plane Beam Splitter Focal Length Illumination Object Reticle f Objective Lens Straightness measurement Flatness measurement Squareness measurement User defined measurement procedures can be added into the standard software by a plug-in mechanism. In addition there is an open programming interface for the integration of the TriAngle measurement functions into other applications. Upon request, TRIOPTICS offers customized Tri- Angle instruments, as for example Increased measurement ranges Larger apertures Vacuum compatibility Focusing objectives Customized illumination Customized sensor technology Operating Principle The operating principle of an autocollimator combines the functions of a collimator and a telescope in a single instrument. The collimator part projects an illuminated reticle to infinity α 2α Mirror Surface and the telescope part receives this image back after reflection at a mirror sur face. Both optical paths are separated by a beam splitter. The received image is brought to the focus of the objective lens in which the CCD of an electronic camera or some other position sensor is located. Autocollimator Operating Principle 4

5 Operating Principle In this arrangement the illuminated reticle and the CCD plane are conjugate. When the collimated beam falls on a mirror which is almost perpendicular to the beam axis, the crosshair image will be located somewhat near the center of the CCD. If the reflector is now tilted by an angle α the reflected image will be laterally displaced by the amount d with respect to the original position. This displacement d is a function of the tilt angle α and the focal length f of the objective lens: d = 2 α f. When d is measured on the CCD the tilt angle α of the mirror can be calculated by α = d 2f TriAngle Product Range Highly Flexible Angle Measurement Solutions The TriAngle series of electronic autocollimators is designed for outstanding performance and flexibility. All TriAngle instruments share the same form factor, depending on the chosen focal length, i.e. objective tube, for the required measurement resolution. The comprehensive and comfortable OptiAngle software communicates with all TriAngle autocollimators. TriAngle - The Most Versatile Electronic Autocollimator This displacement is linear with the tilt angle (small angles assumed) and the measurement result is independent from the instrument s distance to the mirror. Digital Camera CCD Sensor Beam Splitter The TriAngle electronic autocollimator is the standard and most universal instrument of the TriAngle series offering a maximum set of measurement functions including various wedge and prism measurements. It is equipped with a high brightness LED light source and a high-resolution CCD sensor. The compatibility with objective tubes of different focal lengths leads to a Illumination variable measuring range and accuracy Filter Condensor performance between 2.5 and 0.2 arcsec depending on the focal Diffusor Object Reticle length. Objective Lens The TriAngle autocollimators are ideally suited for standard angle measurement and alignment purposes in the laboratory, as well as for the production measurement of prisms and wedges. General setup of a TriAngle autocollimator 5

6 TriAngle Product Range The application suite further includes straightness and flatness measurement tools for the mechanical engineering. The TriAngle electronic autocollimator is available with 8 different objective tubes with focal lengths ranging from 100 mm to 1000 mm. Objective Tube Selection Guide Objective Tube Identifier Effective Focal Length (mm) TA TA TA TA TA TA Clear Aperture (mm) Target Illumination While a high power green LED of 530 nm center wavelength is the standard light source, other illumination types (NIR-LED, Laser, halogene white light source) are available for the adaption to specific sample characteristics. Sensor TriAngle series autocollimators are equipped with modern high resolution CCD camera sensors offering a maximum of image quality and signal to noise ratio. They achieve a standard measuring rate of 30 measurements per second. Higher measurement rates are available upon request. The following specification for field of view is given for standard sensor sizes. Please ask for other sensor sizes, depending on your requirements for field of view and angle resolution. TA TA TriAngle Specification Order Code Type Field of View hor. (x) vert. (y) (arcsec) Resolution (arcsec) Repeatability (arcsec) Accuracy (arcsec) TA TA TA TA TA TA TA TA LED illumination Peak Wavelength Spectral Half-width 530 nm 35 nm TriAngle UltraSpec - Ultra Precision Angle Measurement The electronic autocollimators of the TriAngle UltraSpec Series represent high-precision angle measurement systems for extremely high demands on angle resolution and measuring accuracy. 6

7 TriAngle Product Range TriAngle UltraSpec Applications include: Calibration laboratories Semiconductor equipment manufacturing High-energy physics Laser physics Space science Therefore, TriAngle UltraSpec autocollimators are used for high-end measuring, testing and adjustment processes where highest precision and reliability in angle determination are required, for example: Adjustment and verification of the straightness of linear stages Run-out measurement of rotary tables Measurement of large-area surface flatness Alignment of optical components Alignment of machines and equipment Stability studies TriAngle UltraSpec Application 7

8 TriAngle Product Range Each autocollimator of the TriAngle UltraSpec series is calibrated with PTB angle standards and supplied with test certificates and individual calibration curves. Traceability of the measuring results to international standards of the angle measuring variable is consistently ensured. The mechanically and thermally optimized design of the TriAngle UltraSpec is available with the objective focal lengths 300 mm and 500 mm and permits precise and reliable measurements even under difficult conditions. The optical system of the TriAngle Ultra- Spec autocollimators comprises the superbly corrected objective lens of minimum distortion and a high-resolution digital CCD camera with extremely low sensor noise. The light source employs a stabilized high power LED illuminating the newly developed sensor system for enhanced angle resolution. TriAngle HiSpeed - High Speed Angle Measurement The TriAngle HiSpeed series of autocollimators take advantage of a high bandwidth position sensitive photo detector for angle measurement rates up to 10 khz. The analog signal output of the angular data enables the closed loop control operation for the fast adjustment or angular control operation. The strong laser illumination allows the TriAngle HiSpeed to measure very small and low reflectivity surfaces. TRIOPTICS offers the TriAngle UltraSpec autocollimator as a complete measurement system including a mobile touch-screen control unit with the user-friendly OptiAngle software preinstalled. TriAngle UltraSpec Specification Vacuum compatible TriAngle HiSpeed Order Code Type TA US TA US Focal Length 300 mm 500 mm Measuring range (h v) (1) 3010" 2230" 1800" 1340" Resolution 0.005" Clear aperture Measuring accuracy 45 mm ±0.05" within 10" measuring range ±0.10" within 20" measuring range ±0.25" within the total measuring range The employed position sensitive detector of TriAngle HiSpeed dissipates almost no heat and is vacuum compatible. For special applications in space science and high- energy physics, TRIOPTICS has developed dedicated vacuum compatible versions of TriAngle HiSpeed, to be used e.g. in thermal vacuum chambers (TVC). LED wavelength Measuring rate 530 nm, spectral half-width: 35 nm > 10 measurements / sec (1) within approx. 2 m measuring distance, diminishing beyond this 8

9 TriAngle Product Range TriAngle HiSpeed Specification Order Code Type Field of View (1) (hor./vert.) (arcsec) Resolution (arcsec) Linearity (2) (%) Bandwidth (-3dB) TA HS TA HS TA HS TA HS TA HS khz TA HS TA HS TA HS Laser illumination Wavelength: Output Power: 635 nm < 2 mw (1) sensors for enlarged field of view available (multiply value by 2.5) (2) within 80% field of view TriAngle LASER - Measures at Low Reflectivity The TriAngle Laser is equipped with a laser light source instead of a LED illuminated reticle and employs a CCD camera for the angle measurement. It is ideally suited for the measurement of small optical components, surfaces of low reflectivity, or long distance measurements. TriAngle LASER Specification Order Code Type Field of View hor. (x) vert. (y) (arcsec) Resolution (arcsec) Repeatability (arcsec) Accuracy (arcsec) TA L , TA L TA L TA L TA L , TA L TA L TA L

10 TriAngle Product Range Laser illumination Wavelength: Output Power: 635 nm < 2 mw Customized TriAngle Solutions TriAngle LF with large field of view The TriAngle LF autocollimator has been designed for applications requiring a large measuring range without compromising the measurement accuracy and resolution. It comes with a specially calibrated large field sensor and optimized imaging optics. TriAngle LF Specification Order Code LF Type TA LF Focal Length 100 mm Measuring range (h v) (1) 4 4 Resolution 0.08" Clear aperture Measuring accuracy LED wavelength Measuring rate 30 mm ±1.0" within 80% measuring range 530 nm, spectral half-width: 35 nm > 10 measurements / sec. TriAngle F The TriAngle F series is based on the standard TriAngle design but employs focusing objective tubes for the measurement of slightly spherical mirror surfaces or some other systems with optical power. TriAngle F Order Information Order Code Type Focal Length (mm) Focus Range (mm) TA F ± ± TA F ± ± TA F ± ± TA F ± ± TA F ± ± TA F ± ±50 10

11 OptiAngle Software TriAngle NIR The TriAngle NIR electronic autocollimators employ LED lights which emit in the NIR range. It is used for measurements on material which only transmit light in the NIR range, such as are used in night vision devices. Another application is the laser beam alignment of lasers that emit light at a wavelength in the NIR spectral range. The specific wavelength can be individually selected. Standard wavelength: 1064 nm (other wavelengths available on request) Order Code: OptiAngle Software for TriAngle The Complete Software Package for Angle Measurement The software OptiAngle is a powerful tool covering all aspects of accurate angle measurement with the TriAngle electronic autocollimators in terms of measurement, control and analysis of the angular data. The well organized and modern menu-guided user interface assists even the inexperienced operator to perform accurate measurements and to obtain repeatable results. A large set of pre-defined standard measurement applications is integrated into OptiAngle which cover all established measurement techniques in Main screen of OptiAngle Software 11

12 OptiAngle SOFTWARE optical and mechanical industry. In addition, customized measurement routines can be easily developed and embedded either by TRIOPTICS or the experienced end user. All OptiAngle measurement functions can be further used in other common applications like MatLab, LabView or Visual Basic (Excel). Software Features und Functions The TriAngle software provides many features to simplify the daily use of TriAngle autocollimators whether in the laboratory or in the production environment. Real-time camera display Numerical and graphical display of measurement data Optional full screen camera window (visual alignment mode) User defined graphical scales or indicators inside the camera window Simultaneous measurement with multiple (up to 12) autocollimators Simultaneous measurement of multiple surface reflections (up to 12) Comprehensive data reporting functions ASCII (CSV) data export Selectable angle units for screen display and measurement certificate Software remote control by host computer via RS232 interface Programming interface by MS OLE Automation or via DLL Plug-in mechanism for customized measurement programs User defined measurement certificate layout Demo programming examples for Excel, MatLab, LabView, VBA 12 TriAngle software interface with time chart of angle results

13 Measurement Applications Multiple camera interface technology for IEEE 1394 (Firewire), USB, Gigabit Ethernet, CameraLink or Analog Video Cameras Production mode for batch/lot sample identification and result reporting Easy Integration of Customized Measurement Solutions The OptiAngle software allows the integration of customized measurement Plug-Ins with a dedicated user interface for specialized target applications. Custom specific measurement routines and display functions are quickly implemented to take care of specialized procedures, e.g. in a production environment. The advantages are User interface adapted to specialized applications Increase of throughput Avoidance of faulty operations in production processes Integration of external hardware and software possible Adaptation to familiar data processing and display OptiAngle Programming Interface (API) In addition to the above Plug-In mechanism, the OptiAngle functions can be embedded into a larger measurement framework which then can take control over the full functionality of OptiAngle measurement applications. OptiAngle features an open software concept and programming interface which allows for the flexible and easy integration into other software environments. The angle measurement functions of TriAngle autocollimators can thus be integrated into almost any existing measurement application. In contrast to the Plug-In technology the user himself is enabled to develop the interfacing between the TriAngle autocollimator and his governing application. OptiAngle functions are executed either by sending commands via serial port (RS232) or MS OLE Automation communication, or directly using the DLL based C++ programming interface (API). Existing sample applications and the comprehensive documentation demonstrate the control of TriAngle autocollimators by MatLab, LabView, VBA, Excel. TRIOP- TICS will be happy to assist the user to integrate the TriAngle functions into his own application. TriAngle modular software concept Measurement Applications Typical TriAngle Measurement Applications The applications of TriAngle autocollimators are mainly related to the detection and measurement of small angular displacements. TRI- OPTICS has successfully supported customers in a wide area of application fields. Assembly and adjustment of optical components like mirrors, prisms, windows, wedges etc. Alignment of machinery 13

14 Measurement Applications TriAngle autocollimator measuring pitch and yaw of a linear stage Proof of straightness and flatness of tables, rails, linear guides, etc. Measurement of yaw, pitch and roll errors of linear stages Characterization of rotation stages (wobble and run-out measurement) Measurement of wedge, prism and polygon angles Measurement of parallelism of reflecting surfaces CD/DVD ROM alignment (focusing and tracking) Thermal stability investigations Analyzing the stability or deformation of mechanical or optical constructions Vibration analysis Alignment of astronomical systems Alignment of components for the beam control in high energy physics Inspection of solid state Laser rods and many more... Straightness Measurement The straightness measurement is the daily practice of manufacturers of linear stages, guides and rails whether in precision mechanics or machine tools. The travel of a moving carriage is investigated regarding angular motion errors square to the direction of movement, called yaw, pitch and roll errors. A reference mirror mounted to the carriage is moved with a constant step length b along the stage or rail to be measured. For each step the angular output α i of TriAngle autocollimator is recorded. The software displays the angular measurement data as well as the straightness deviation δ in µm units. Motor driver software modules for standard DC- and stepper-motors are included which makes the measurement of motorized stages very convenient. A few prominent examples will be given in the following sections. 14

15 Measurement Applications Straightness measurement with TriAngle δ (z n ) = b Σ n i=1 tanα i 3D Straightness measurement Wedge Measurement The inspection of optical wedges with an autocollimator is the fastest and most convenient way of measuring wedge angles, especially in production environments. When the parallel beam emerging from the TriAngle autocollimator is directed square to the wedge it is reflected back from both the front and the back surface of the wedge. As the result, two crosshairs are displayed on the camera screen, with a distance d depending on the wedge angle and the refractive index n of the material. The wedge angle δ is given by Where δ = d 2nf d = distance of both surface reflection images n = refractive index of the wedge material f = focal length of the autocollimator 15

16 Measurement Applications The wedge angle is automatically computed by the software according to the above formula. The software further includes the program for the wedge measurement in transmission (double pass) with reflection at a mirror behind the wedge. With this procedure the resolution is doubled by the double pass configuration. Calibration of Index Tables and Rotary Encoders The accuracy of goniometers and rotary machine axes equipped with angular encoders is mainly determined by the run-out error of the mechanical axis, manufacturing errors of the encoder scale and the eccentricity between axis and encoder. The absolute calibration of the angular readings of goniometers and rotary encoders is often made by the rosette technique. This procedure is based on measuring the difference of the angles between two adjacent facets of a precision polygon mirror. By measuring all the facet angle differences a calibration curve is obtained which can be used to correct the angular readings of the encoder for the complete system, whether machine axis, goniometer or index table. The calculations involved are quite cumbersome and complex without software assistance, but easily done with the dedicated software Plug-In of the OptiAngle software. The measurements can be performed with manual axis rotation or with motor control if available. 16 Measuring a wedge angle in reflection mode

17 Technical Data/Order Information OptiAngle Plug-In for index table calibration Technical Data and Order Information Order Information TriAngle Type: TA Objective tube diameter Focal length (mm) Delivery Kit TriAngle Electronic Autocollimator PCI interface card OptiAngle Software Package on CD Protection Dongle Interface cables Individual Certificate of Calibration traceable to PTB angle standard Clear Aperture: TA...-38: 30 mm TA...-57: 50 mm TA...-57: 100 mm TA...-57: 125 mm 17

18 Accessories Measurement Capabilities and Recommendations Measurement Task TriAngle TriAngle UltraSpec TriAngle HiSpeed TriAngle LASER Tilt angle Analyzing more than one optical surface Wedge angle in reflection Wedge angle in double pass 45 prism error 90 prism error Wobble Vibrations Low reflective surfaces High precision measurement Calibration tasks Straightness measurement Flatness measurement Standard TriAngle Configurations TriAngle TriAngle Ultra Spec TriAngle HiSpeed TriAngle LASER Sensor CCD Camera CCD Camera PSD CCD Camera Light Source LED LED Laser Laser Interface IEEE 1394 IEEE 1394 Analog, USB IEEE 1394 Different configurations are available upon request Accessories Opto-mechanical Accessories In addition to the TriAngle electronic autocollimator series, TRIOPTICS offers a large range of opto-mechanical accessories, often required for certain standard applications. 18 TriAngle TA 300 in 2-axis adjustable holder with reference mirror

19 Accessories 45 deflection mirrors D38 and D57 Clamp fixtures D57 and D38 2-axes tilt adjustable Holder with V-prism fixture D 57 and D 38 2-axes tilt adjustable Holder with V-prism fixture D115 and D57 19

20 Accessories Order Information Order Code Type Clamp fixture D 38 mm Clamp fixture D 57 mm Clamp fixture D 57 mm, with height adjustment Clamp fixture D 115 mm axes tilt adjustable Holder with V-prism D axes tilt adjustable Holder with V-prism fixture D axes tilt adjustable Holder with V-prism fixture D axes tilt adjustable Holder with V-prism fixture D axes tilt mount wit micrometers D axes tilt mount wit micrometers D LA 57 Laser Pre-Alignment Device LA 115 Laser Pre-Alignment Device LA 140 Laser Pre-Alignment Device Iris Diaphragm D deflection mirror D deflection mirror D deflection mirror D Base mirror, D75, base length 100 mm View finder autocollimator alignment tool Calibration wedge in mount, accuracy 1 arcsec Reference 90 prism, mm, accuracy +/-0.5 arcsec Reference 90 prism, mm, accuracy +/-0.5 arcsec Penta prism, accuracy 5 arcsec 20

21 TRIOPTICS GmbH. Optische Instrumente Hafenstrasse Wedel / Germany Phone: Fax: info@trioptics.com TRIOPTICS GmbH. All rights reserved