Quality Magazine

Supplement Cover Story: Seeing What No One Has Seen Before

February 1, 2004
Microscope capabilities continue to grow.

The microscope employs a quick-release system in the stage. Photo: Mitutoyo America Corp.


The Nexiv VMR-Z120X has a dual optical system producing magnifications from 36X up to 4320X. Photo: Nikon Instruments Inc.

The lenses of the Hubble Space Telescope have looked into the cosmos and may soon bear witness to the birth of the universe: the Big Bang, or, the Big Picture. Thanks to microscope manufacturers, we are seeing the invisible-the magic that makes things tick: the billions of little pictures responsible for the big picture. In each case, a collective need to see has propelled society to fantastic places that a few short years ago could only be imagined.

Also driving progress is the need for faster, cheaper, smaller. That has been the mantra in recent years for engineers across the manufacturing landscape. Ditto for manufacturers of microscopes, with an emphasis on smaller.

"Products have shrunk to incredible dimensions, and we now routinely talk about structures near or beyond the limit of brightfield optical resolution, such as carbon nanotubes," says Gary Czarnecki, Finescope Sales Supervisor at Mitutoyo America Corp. (Aurora, IL). "Consequently, the need continues for new products to inspect these tiny geometries, which are as unlimited as the products themselves, from medical implants to ultra-small microelectric motors."

New microscopes are also easier to use and more ergonomic, Czarnecki says. This means "microscopes have fewer knobs and adjust quickly to accommodate various work samples. To reduce stress and strain, microscopes now routinely can be configured to have extending, tilting binocular bodies; low-position, full-forward x/y motion stage controls; and eyepieces with larger fields of view."

Mark Glowacky, president of RAM Optical Instrumentation (ROI, Tempe, AZ), adds that video has expanded the microscope's capabilities. "With a video camera in place of an eyepiece, magnified color images can be viewed by groups of people at the same time," he says. "This reduces stress on the inspector and aids in training."

Specialized microscope objectives do not require the part being inspected to be held at a constant working distance from the lens, Glowacky says. "In addition, the lens is purposely not telecentric, so the part is magnified as it is moved closer to the lens. This simplifies inspection of handheld parts where a large area is imaged when the part is as much as 6 inches from the lens."

Today's microscopes also have greater motorization, says Dan King, assistant product manager for materials microscopy, Carl Zeiss MicroImaging Inc. (Thornwood, NY). "They are more intuitive and easier to use than previous generations, which has created a broader user base."

Because measurement with microscopes involves getting actual quantitative values on the size and location of features on a part, these microscopes often incorporate calibrated scales, digital readout and a video camera for edge analysis and automation, says Tom Groff, corporate product manager for QVI, which is the parent company of Optical Gaging Products, RAM Optical Instrumentation and View Engineering. "More advanced microscopes include motorized stages and automation software for automatic inspection. The line between a conventional microscope and an automated vision system is becoming blurred due to advancements in technology and video signal processing."



The VDM-EZ is a compact system that incorporates video technology. Photo: RAM Optical Instru-mentation Inc.

Going Digital

To boil down to a few words what's happening in the world of microscopes, "We have joined the digital revolution," says Mike Metzger, department manager, measuring instruments, for Nikon Instruments Inc. (Melville, NY). "Everything in our world is moving from the analog world to the digital world. And, boy, are we moving fast."

As an example, Metzger points to cellular phones. "The analog cell phones are gone, and it only took a few short years."

For users of microscopes, that means information is obtained more quickly and accurately. Digital cameras help users obtain higher quality images than ever before and computers help them determine what to do with the observed part or object-accept it, reject it or rework it, for instance.

One example of what the newer generations of microscopes can do involves a contractor that was working on an assembly process for a multimillion dollar defense project. The positioning of the component had to be done under magnification, and it was critical to the performance of the product and the price of the final assembly.

"A measuring microscope ended up being the most viable solution because it had the final magnification they needed, the advanced contrasting technique necessary to see the important feature and the digital precision staging mechanism required to provide the positioning data for the assembly process," Metzger says. "Without having the positioning data, which is done with a precision scale and computer, they couldn't have done the job."

In another example, a Tier One supplier of automotive brake parts switched from a stereo microscope containing an eyepiece reticle to an automated measuring microscope, which improved productivity and reduced costs. The company needed to inspect many of the parts coming off the production line to ensure they were meeting specification.

The customer needed to see the two divisions to which the part was machined. The stereo microscope worked fine for years, but it was no longer practical because the company needed to get the dimensional information into its statistical process control (SPC) system. A new automated measuring microscope was able to see the detail and, using a digital camera and computer, detect the edges automatically, measure the part and send the information to the SPC system.

Another example involves a medical-device manufacturer that made products that were inserted into the human body. For this type of use, ensuring that the product meets specification and is free of contamination is critical.

"This customer required that we shine a specific wavelength of light onto the parts to look for organic contamination," Metzger says. "Now we have fluorescent attachments for stereo microscopes that can do the job. These advances in optics allow us to see things we never saw before."

An increasingly important use of new microscopes is in conjunction with software and high-end digital cameras to create versatile imaging platforms, King says. "These systems allow the user to save images in an archive for further use or to integrate such images into reports for presentations and other documentation."

Through the Internet, these images can be seen simultaneously at locations worldwide. New software allows users to manipulate the images from remote locations-to zoom in on a particular area of a part on someone else's workstation, for example. The implications for productivity are enormous.

Another big change is that many microscopes are switching from halogen illumination to what is known as "cool light," or white LED illumination. That is a very important emerging technology, Metzger says, because it is more easily and precisely controlled by a computer, by filters and through digital means.

The digital world also is helping manufacturers produce lenses with less distortion, higher resolution and greater color rendition. "For years, we said that producing lenses was more art than science," Metzger says. "That has completely changed."

"There are no perfectly straight lines or perfectly round surfaces; there is always variation in our world," Metzger adds. "The more we can reduce variation, the more perfect something becomes."

All of these improvements are important because they are helping manufacturers prepare for the migration from the micro world to the nano world. Because of developments in sensors, actuators, semiconductors, biomems and wireless technologies in various industries from aerospace to medicine to automotive, the ability to see ever-smaller details is more crucial than ever.

"Many major markets are pushing smaller, faster, cheaper," Metzger says. "Smaller is a key. We need our digital technology to take these images and analog information and turn it into data so that high-powered computers can better analyze these smaller things. Our brains just can't do it any more."

Advancements also are being made in contrast techniques for stereo microscopes. For example, very low contrast samples sometimes seem invisible and must be seen through image amplification or illumination. In "oblique coherent contrast," for example, illumination directed at an object from the side could amplify a substance that may otherwise blend in with the surface upon which it rests.

Lasers, too, are part of the new microscopy landscape. They are incorporated into the optics to measure heights and the topography of samples as fast as 1,000 points per second, Metzger says.

Czarnecki adds, "Future inspection microscopes, like some on the market today, will be highly integrated, digital imaging measuring platforms run by computers. They may or may not require direct observation by a viewer, this function being monitored on a CRT.

"Instead of being viewed only as a measuring microscope, in the sense we do today, microscopes will be highly automated and capable of detecting and measuring these small structures with light we cannot see," Czarnecki says. "This will be accomplished by using the microscopes as the basic unit combined with advanced computer software, high-resolution digital cameras and improved optical techniques, such as the deep UV Confocal microscope and UV digital cameras."



The Axiovert 200 MAT features high-performance optics. Photo: Carl Zeiss

Available Microscopes

The following is a roundup of some of the available microscope products on the market. While this list is not complete, a more comprehensive listing is available at Quality magazine's online Buyers Guide at www.qualitymag.com

Mitutoyo America Corp.'s MF-A/MF-UA microscopes employ a quick-release system in the stage. This allows the operator to switch between a coarse movement and fine movement instantaneously, and the stage is completely freed by only slightly turning the focus handle clockwise. This function is especially useful when the distance of the measuring position from the reference point is long or when returning to the reference position quickly. The Zero-switch allows operations with both hands remaining on the handle except when focusing. Reply #600

JEOL-USA's JEM-2100F Transmission Electron Microscope (TEM) features maximum stability for high resolution imaging at the sub-nanometer scale. The 2100F features atomic-level stage movements, a small probe size of less than 0.15 nanometer, and the ability to integrate a variety of CCD cameras and detectors allow for simultaneous, multiple analytical techniques. New microprocessing and networking capabilities, plus Windows OS interface, simplify operation and speed data acquisition. Reply #601

RAM Optical Instrumentation Inc.'s VDM-EZ is a compact microscope system for high-magnification inspection through the use of RAM video technology. Video imaging technology from RAM Optical presents high-resolution color images on a 13-inch monitor for viewing by an individual or group. Two interchangeable lens options are available, the EDF objective and the 6.5:1 zoom objective. Reply #602

LECO Corp. and Olympus offer the GS-Series Inverted Metallographs. The solutions for image clarity and resolution in material sciences, the modular GX51 and GX71 models offer a broad range of applications including production control, quality control and advanced research to be implemented. Built with a solid aluminum casting for improved stability and vibration control, the two models offer objectives ranging from 1.25X to 250X; reticle sliders that accept grain size, micron marker and intercept methods; and a variety of optional filters. Reply #603

Carl Zeiss' Axiovert 200 MAT has a wide range of applications, from analyzing microstructures to measuring particles and grain size. Developed specifically for the industrial market, the product provides a combination of high-performance optics, easy use, innovative techniques, sophisticated features, unshakable stability and a choice of a manual or motorized stand. Reply #604

The SBS-20 from Detroit Testing Machine Co. features a micrometer measuring eyepiece for simple, accurate indentation reading and can be used under normal lighting conditions. It comes with a carrying case for safe storage and meets ASTM E-10 specifications. Reply #605

The EVO scanning electron microscope from LEO Electron Microscopy Inc. features high-resolution optics, analytical chamber designs and specimen stages. The XVP (extended variable pressure) imaging capability of the EVO 40, 50 and 60 series provides imaging and analysis of specimens within a pressure range of 1 to 750 Pascal using water vapor or air. The microscopes can be upgraded for future requirements, such as high vacuum and extended pressure, combining 8.5-millimeter working distance and take-off angle of 35 degrees, along with the LEO32 graphical user interface, high-resolution image storage and Windows XP operating system. Reply #606

Vision Engineering's LYNX stereo-zoom microscope produces images to 120X magnification on a large viewing area. The company's Dynascope technology promotes operator comfort and eliminates neck and back strain. Features include image brilliance and long working distances for applications where manipulation is necessary. Accessories such as digital camera options are also available. Reply #607

The ProScan TMII stepper motor controller from Prior Scientific Inc. automates microscopes and is capable of controlling up to six stepper motors that control a motorized stage, focus motor, three filter wheels and three shutters from a single controller. A fourth axis driver is available to control sample rotation or an additional custom application. The unit also offers four TTL inputs and outputs for triggering camera shutters, relays, linescan cameras or other peripheral devices. Reply #608

Leica Microsystems has introduced the DM Digital Microscopes, which use intelligent automation for advanced imaging techniques. The series includes the DM4000 M for routine and research applications in materials science. The DM4000 M is designed to deliver optimized imaging by selecting the objective, filter and contrast method. All aspects of the light path are automatically adjusted to the user's preferred settings. It features a number of innovations, including a fluorescence intensity manager that automatically sets the fluorescence illumination. Reply #609

Nikon's VMR-Z120X has a dual optical system producing magnifications from 36X up to 4320X, enabling imaging and measurements of part features down to 1 micrometer. Inspections of complex designs are improved with Nexiv's combination of optics, as well as the intelligent search software and TTL laser scanning. The 120X Telecentric Zoom System enables high throughput precise measurements of heights, complex profiles and critical dimensions. Reply #610

The Versamet 3 from Buehler Emerson Electric Co. has an inverted metallurgical design with an erect image. It has a 200 by 200 millimeter graduated stage with 30 by 45 millimeter travel. It has a 100W quartz halogen illuminator and is available with several objectives. Reply #611

The Flexbar DigiScope video miscroscope system has a zoom range of 1:4 and magnification of 10X to 40X. It combines stereo zoom optics with a built-in CCD camera, plug-and-play computer output, and imaging and measurement software. Reply #612

The RZ series of modular stereo microscopes from Meiji Techno has been engineered around a common main object and parallel optical paths to offer distortion free, high-resolution images at magnifications ranging from 3.75X to 300X. It features a 10:1 zoom ratio. Reply #613

Pyser-SGI Ltd. offers a range of compound microscopes include the XE-M2 which features a metal die cast body, 45 degree inclined and 360 degree rotatable monocular head, a single 2X ojbective and rack and pinion focusing. Reply #614



Benefits

  • Microscopes must explore products that have gotten smaller. Some structures have gone beyond the limit of brightfield optical resolution.
  • Today's microscopes are easier to use, more ergonomic and incorporate improved data analysis and collection software.
  • By incorporating video, microscopic images can be magnified and simultaneously seen at different locations.
  • Many microscopes now can incorporate digital cameras.