Profile Projectors / Shadowgraphs
An automated, instant measurement system that provides highly accurate and repeatable measurement data in seconds; simply place a part on the stage and push one button! Hundreds of critical features can be dimensioned on the part anywhere within the system's field of view. Built in automatic edge detection software allows for measurements to remain consistent among all operators and eliminate subjectivity. This user friendly tool can be used by anyone to compliment your quality control processes whether it is being used in a lab or out on the shop floor.
Products Lineup
Capable of high-definition imaging, the IM-8000 Series Image Dimension Measurement System has triple the detection performance of conventional systems without sacrificing its simple operation; just place the part on the stage and press one button. With a 20-megapixel CMOS sensor and a new algorithm for stable edge detection, high-accuracy measurement on up to 300 features within seconds is now possible. A newly developed, optional automated rotary fixture allows for 360' multi-surface measurement on diverse part sizes and shapes. Achieve accurate and repeatable measurements instantly with its 'place and press' operation; this ensures consistent results regardless of operator experience. The fast, accurate, and easy-to-use interface of this product solve various measurement-related problems.
The LM Series High-Accuracy Instant Measurement System is an automated inspection system that can perform measurements to +/- 0.7 µm accuracy and +/- 0.1 µm repeatability at the push of a button. Similar to the IM Series, the unit has built-in edge detection with automatic focus and lighting. The unit also automatically records measurement data and creates detailed inspection reports. The image showcases our latest LM-1100 model which houses high-resolution double telecentric lenses for precision optical inspection and a large 9 x 5 inch field of view.
Profile projectors are a type of optical measuring instrument used for inspection and measurement in the manufacturing industry. The measurement principle is similar to that of optical microscopes, meaning that no physical contact is needed when using a profile measuring tool. This is unlike handheld tools, such as measuring tapes or vernier calipers, that use contact between the tool and part for measurement.
Let's take a look at the process of using a profile projector. First, the target is placed on the stage, and a light is shone on the target from underneath. This causes the target's profile, or shadow, to be projected on the screen. Once the shadow is projected, there are two ways to use a profile projector. The technician can either measure on the profile projector by silhouette measurement or by point comparison. Silhouette measurement refers to measuring the shadow while incorporating magnification distortion. Alternatively, point comparison uses a screen with a predicted image. The shadow is then moved to hit each point on the image, and the technician measures the distance that the profile projector stage moved.
KEYENCE's version of profile projectors – Instant measurement systems (IM) – uses advanced technology to make the measuring process faster, easier and more accurate. Once a part is projected on the screen using a combination of lights, precision lenses and high-resolution camera, these automated profile projectors process the shape of the object while automatically removing burrs and chips that cause inaccurate measuring. Once the shape is processed, part measurement is automatic and instantaneous with the results displayed on-screen. This telecentric optical system is used to enable accurate measurements with no error resulting from operator skill.
How Does A Telecentric Optical System Work Differently?
Standard profile projectors can warp the shadow from an object depending on the height and width, meaning that there is extra time needed for correct measurements. KEYENCE added a telecentric lens in their profile projectors for distortionless shadows on the profile projector.
With the telecentric lens on the profile projectors, the system can keep a constant and accurate magnification. Instead of variations based on size, the telecentric lens on the IMs secures a 2D image birds-eye view without any prospective angle error from different heights. Not just that, but KEYENCE's system automatically adjusts the lighting, focus, and orientation of the program to correspond with the part (or parts) on the stage and produce quick results.
Profile Projector Principle (Telecentric Optical System)
Profile projectors were originally developed to inspect the outlines of targets. Models equipped with measurement functions appeared later. Some large profile projectors have screen diameters that exceed 1 m.
Profile projectors are also commonly known as profile projectors, shadowgraphs, or profile measuring tools.
A typical profile projector illuminates from below and projects the shadow of the measuring object placed on the stage through a projection lens onto a projection screen. These reasons are why it is also known as a profile projector or shadowgraph.
At this time, the size of the projected image is an image magnified with a correct magnification from the measuring object, and the dimension of the measuring object is measured by measuring this image.
An optical system called a "telecentric optical system" is used in the profile projector so that it can be projected with accurate magnification from any position on the stage. The telecentric optical system differs from conventional lenses because there is no profile projector lens distortion. With a general lens, near objects look large and distant objects appear small, which allows you to judge perspective. Telecentric lenses, on the contrary, project the same size for near and far objects.
This telecentric lens on KEYENCE's profile projector allows you to capture the image of an object at the correct magnification without warping the image.
KEYENCE's IM Series Instant Measurement system profile projector was designed to be the next-generation profile projector. Known for the motto "Just place and press," KEYENCE's profile projector system makes the measuring process a seamless activity that cuts down hours of inspection time.
A: Projection screen, B: Projection lens, C: Movable stage, D: Stage movement handles (X and Y handles)
Precautions, Maintenance and Calibration
Conventional profile projectors require regular maintenance in order to continuously and accurately perform measurements. Maintenance is often performed onsite by a technician as the tool is generally too large to be sent off for regular maintenance.
In addition, regular calibration is required to confirm that the accuracy is as specified. A profile projector's calibration cycle is 6 months to 3 years. As with maintenance, calibration is generally performed locally.
Benefits of a Profile Projector
A primary feature of profile projectors is that they have two dimensional measurement capabilities (X and Y directions), unlike hand tools such as micrometers, vernier calipers or height/depth gauges, which are limited to measurement in only one direction at a time.
The benefit is that it enables inspectors to double their output compared to the one direction hand tools. Operators can line up the lower left-hand corner of the image with the screen centerline to set up an origin point and get a simultaneous reading of both length and width helping to streamline inspection processes.
Profile projectors use a non-contact measurement that doesn't skew the measurement of flexible parts or damage sensitive parts. During the inspection process, nothing but light touches the part, so the part doesn't have any potential to warp or change shape.
A major benefit beyond part integrity is that non-contact gauges also eliminate the "feel factor" and resulting human error of hand gauges. With this subjectivity removed, companies see an improvement in the consistency of their measured values.
Companies can see cost benefits through profile projector utilisation. One way is that they can reduce inspection time with profile projectors by measuring faster than conventional handheld gauging.
With the time saved and increased throughput, there can be a significant impact on profitability. Another cost saving comes in the form of hard gauges. By using optical methods more, you greatly reduce the wear of hard gauges. Also with more wear and need for periodic recertification, there's a requirement for additional substitute tools to use during these down periods which can now be eliminated with optical methods.
Place the object on the stage of the profile projector.
A scale is applied to the image projected enlarged on the profile projector screen to measure the dimensions. Alternatively, you can use the XY stage together and measure the dimensions from the amount of movement.
A profile measuring tool with a computerised calculation function can obtain various measurement results such as width, diameter, and angle by taking measurement points while moving the stage of the profile projector.
How to Measure a Length/Width Using a Profile Measuring Tool
Place the object to be measured on the screen and adjust the height of the profile projector table to focus.
Next, align the orientation of the side you want to measure on the projected image with the orientation of the screen reference line. Adjust the value of the XY stage to 0.
Next, move the profile projector stage using the stage movement handle and align the other side of the projected image to be measured with the screen reference line.
At this time, the movement amount of the profile projector stage is displayed in each of the X and Y directions, so this value becomes the measured value. In the case of simple measurement in only one direction, the amount of movement on the profile projector in only the X or Y direction is used.
How to Measure a Radius /Diameter with a Profile Projector
Place the object on the profile measuring tool to be measured on the screen and adjust the height of the table to focus.
Next, align the center point of the circle on the projected image with the point where the screen reference line is public.
In the case of radius, take 0 points here and move the stage to check the movement amount at the point where the edge of the circle was at the center of the stage. In the case of diameter, move the stage once from here to the edge of the circle, take 0 point, and move to the opposite edge to check the amount of movement. In either case, it is common to measure in four directions in a cross shape.
It is also possible to measure on the profile measuring tool by applying a concentrically graduated sheet called a "chart" to the screen.
In the case of a profile projector with a calculation function, the diameter and radius are automatically calculated by taking three measurement points at the edge of the circle.
How to Measure Angles on a Profile Projector
There are several ways to measure the angle with a profile projector.
A method of checking the amount of rotation is by rotating the profile projector stage in the θ direction by aligning the straight line of the projected image with the reference line of the screen.
There is a method of checking by putting a sheet called a "chart" with a fine scale like a protractor on the screen.
On a profile projector with a calculation function, the angle is calculated by specifying two straight lines.
How to Use Overlays
There are several types of charts that can be used with a profile projector.
For measuring the diameter and radius, there are concentric circle marks. For measuring angles, there are radial marks. In addition, some of the scales are written in a grid to see the XY coordinate values. Both are placed on the profile measuring tool screen and measured by matching them with the projected image.
Fixtures
Fixtures used for profile projectors are used to fix the object in place to be measured in the correct orientation. For example, a round object can be fixtured horizontally by clamping it down or for fixing an object whose bottom surface is not flat in an orientation suitable for measurement.
There are various types of fixtures for profile projectors, including clips, clamps, and magnets.
Mylar Overlay Chart
The overlay chart is used by matching it with the measurement image projected on the screen. There are various types of charts. For example, those with a grid or concentric scale are generally used.
In addition, by overlaying the diagram chart in which the design value of the measurement target is magnified at the same magnification, it is possible to see how the contour of the design value differs from the actual measurement target by superimposing it on the projected image.
Surface Illumination
The profile projector can not only illuminate from below and transmit light to create a shadow, but it can also illuminate from above (lens side) to project outlines.
Even if the measurement target is difficult to measure with only the transmission (backlit) image, it is possible to measure it by using the epi-illumination on the profile projector.
Curtain
Blackout curtains are used to block light coming from outside. It is used to project a shape more accurately on a profile projector by blocking ambient light.
While the profile projector is a convenient measuring instrument that can perform various measurements, users can encounter a few obstacles when using a conventional profile measuring tool.
Measurement Stability
The position to focus on a profile projector differs depending on the person, causing a measurement error.
Work efficiency and measured values differ depending on the skill of the person.
Not only does the skillset of the person measuring affect the values, but there are other shop floor factors too. For example, ambient vibration from work on the shop floor may disrupt positioning. Another factor may be the number of people who use the profile projector and produce different measurements.
Responsiveness
When comparing shapes, it is necessary to superimpose a 10x enlarged drawing on the projected image and visually confirm the difference.
It is not possible to acquire the numerical values of the differences from the dimensions and drawings with the measuring instrument.
It is difficult to store and compare data, such as transferring contour shapes to trace paper.
Cost and Effort
It takes time to manually move the profile projector XY stage to adjust the position and orientation of the target object and acquire the coordinates of the measurement points one by one to measure.
In the case of an object with a step, it is necessary to focus on each change in the height of the measuring point.
Writing various documents and contour shapes is a manual process requiring many man-hours.
Furthermore, you require a specialised technician to operate a profile projector, report measurements, and draw up reports. If your company doesn't already have one employed, outsourcing can be costly.
Why choose KEYENCE?
Ease-of-Use - Just place a part on the profile measuring tool system's stage and push a button on the profile projector to fully inspect a part. The IM Series works with various parts, like machined parts, resin molds, springs, and die-cast parts. There is no tedious learning curve for measurement or the possibility of human error. Instead, all that is needed is a few clicks and seconds for the IM Series automated profile projector to automatically recognise the position and orientation. Even with multiple types of parts on the stage, the IM profile projector identifies each one and can differentiate the measurement results.
The profile projector system automatically measures a part in 3 seconds or less. Not only does the system measure quickly, but it also speeds up overall measuring time by measuring up to 100 parts simultaneously. Even more, the time used for carefully focusing conventional measuring tools multiple times from various positions is completely eliminated with KEYENCE's profile projector.
High-precision optics and cameras allow for up to +/- 2um accuracy. The accuracy of KEYENCE's version of a profile projector competes with the manual measuring processes because of how easily measuring can be affected by other factors. For instance, someone's vision and metrology skill level will affect the measurement output. On the flip side, KEYENCE's profile projectors are almost completely automated and have slim to no possibility of human error.
Speed and accuracy relate to the actual profile projector measuring, but KEYENCE can go even further and increase overall productivity with the image dimension built-in software features. In seconds, the IMs report statistical values, measurement data, inspection reports, trend graphs, and histograms. With these features, parts move more quickly through the profile projector measuring process.
Looking to streamline your measurement process by adding KEYENCE's profile projector to your toolbox? KEYENCE's profile projectors don't require any metrologist experts to measure up to 100 parts at a time. Instead, the intuitive software only requires a press of a button for you to start measuring parts and receiving measurement feedback.
Here at KEYENCE, we pride ourselves in our expert teams and confidence in our products– which is why we offer a free demo for you to see what KEYENCE's profile projectors do. Contact us today, and our quick team will get back to you to schedule a demo!
Frequently Asked Questions About Profile Projectors
Profile projectors are designed for two-dimensional visual inspection. For this reason, a part would need to be reoriented and remeasured on the profile projector for three-dimensional features. Another method would be to use a combination of tools, such as a profile projector, calipers/micrometers, and height gauges. For example, you can measure any two-dimensional feature using the profile projector but then move the part over to a height gauge to get any required heights or depths. The final measured results from the profile projector can be manually written on a report or typed into an existing reporting platform.
KEYENCE's IM Series automated profile projector measures up to 99 dimensions on a part in 3 seconds or less at the push of a button to +/- 2um accuracy. Once the part is measured, the profile projector system automatically records the data and creates an inspection report. Our latest profile measuring tool unit has a built-in height gauge for Z-axis measurements. When compared to a traditional profile projector, companies see a significant reduction in inspection time, operator subjectivity, and scrap and rework. The advantages in measurement speed, accuracy, and ease of use of the profile projector are immediate.
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