To learn what kinds of applications are well-suited for a Contact Image Sensor
To see the unique features only found in the Teledyne DALSA AxCIS series
You already know (or can catch up quickly):
Contact Image Sensors don’t actually contact the things they are imaging. But they get to within 15 mm = 0.59 inches! So they are ideal for space-constrained applications.
And they aren’t interchangeable with line scan cameras, they are a variant on line scan concepts. They share the requirement that “something is moving” and that the sensor array is a single row of pixels.
Applications for Contact Image Sensing
Courtesy Teledyne DALSA
Why Teledyne DALSA AxCIS in particular?
You may want to review the whole Teledyne DALSA AxCIS series, and the datasheet details. Go for it! Geek out. Full transparency as always.
Or maybe you’d like a little help on what we think is special about the Teledyne DALSA AxCIS series?
T2IR – Trigger to Image Reliability
This is a Teledyne DALSA proprietary innovation that helps to de-mystify what’s happening inside a complex vision system. It uses hardware and software to improve reliability. In high level terms, T2IR monitors from trigger through image capture, and on to host memory transfer, aiming to protect against data loss. And to provide insights for system tuning if needed. T2IR is compatible with many Teledyne DALSA cameras and frame grabbers – including the AxCIS series.
About you: We want to hear from you! We’ve built our brand on our know-how and like to educate the marketplace on imaging technology topics… What would you like to hear about?… Drop a line to info@1stvision.com with what topics you’d like to know more about
Unless one calculates and sets the line rate correctly, there’s a risk of blur and sub-optimal performance. And/or purchasing a line scan camera that’s not up to the task; or that’s overkill and costs you more than would have been needed.
Perhaps you know about area scan imaging, where a 2D image is generated with a global shutter, exposing all pixels on a 2D sensor concurrently. And you’d like to understand line scan imaging by way of comparing it to area scan. See our blog What is the difference between an Area Scan and a Line Scan Camera?
30 minute informative overview of Line Scan imaging – Courtesy Teledyne DALSA
Maybe you prefer seeing a specific high-end product overview and application suggestions, such as the Teledyne DALSA 16k TDI line scan camera with 1MHz line rate. Or a view to tens of different line scan models, varying not only by manufacturer, but by sensor size and resolution, interface, and whether monochrome or color.
Either you recall how to determine resolution requirements in terms of pixel size relative to defect size, or you’ve chased the link in this sentence for a tutorial. So we’ll keep this blog as simple as possible, dealing with line rate calculation only.
Line scan cameras – Courtesy Teledyne DALSA
Calculate the line rate
Getting the line rate right is the application of the Goldilocks principle to line scanning.
Line rate too slow…
Line rate too fast…
Blurred image if due to too long exposure, and/or missed segments due to skipped “slices”
Oversampling can create confusion by identifying the same feature as two distinct features
Why we need to get the line rate rate right
A rotary encoder is typically used to synchronize the motion of the conveyor or web with the line scan camera (and lighting if pulsed). Naturally the system cannot be operated faster than the maximum line speed, but it may sometimes operator more slowly. This may happen during ramp up or slow down phases – when one may still need to obtain imaging – or by operator choice to conserve energy or avoid stressing mechanical systems.
Naming the variables … with example values
Resolution A = object space correlation to sensor; FOV / pixel array; e.g. if 550mm FOV and 2k sensor = 550/2000 = 0.275 pixels per mm
Transport speed T = mm per sec; e.g. 4k / 1mm yields rate of motion
Sampling frequency F = T / A; for example values above F = 4000 / 0.275 = 14545.4545 = 14.5kHz; spelled out: Frequency = Transport_speed / Pixel_spatial_resolution (what 1 pixel equals in target space)
For the example figures used above, a line scan camera with 2k resolution and a line scan frequency of about 14.5 kHz will be sufficient.
Justclick here, or on the image below, to download the spreadsheet calculator. It includes clearly labeled fields, and examples, as the companion piece for this blog:
Not included here… but happy to show you how
We’ve kept this blog intentionally lean, to avoid information overload. Additional values may also be calculated, of course, such as:
Data rate in MB / sec: Useful to confirm camera interface can sustain the data rate
Frame time: The amount of time to process each scanned image. Important to be sure the PC and image processing software are up to the task – based on empirical experience or by conferring with software provider.
About you: We want to hear from you! We’ve built our brand on our know-how and like to educate the marketplace on imaging technology topics… What would you like to hear about?… Drop a line to info@1stvision.com with what topics you’d like to know more about
Superior vibration resistance and mechanical design
Two of six available ML-M-HR lens models – Courtesy Moritex
Value Engineering
Every field with diverse product offerings has its own broad mix from which to choose. Some offerings are generalized; some fit a specific niche. When designing a machine vision application, and choosing components like cameras, sensors, lenses, lighting, etc., each component has to be at least slightly better than “good enough”, but need not be more than needed. The whole field of value engineering has evolved to guide practitioners in achieving required functionality while also respecting budgetary goals.
Larger FA series design goals which ML-M-HR series share- Courtesy Moritex
Moritex ML-M-HR lens series
The Moritex ML-M-HR series is part of Moritex larger FA Series of lenses. The “FA” stands for Factory Automation, which suggests points including:
Robust mechanical engineering
Quality designed to deliver reliable results and stand the test of time
Priced to permit volume purchases by achieving return on investment
Of course, the lenses are not constrained to factory automation, and you may purchase as few as you need. The factory automation insight just helps to understand their design heritage and largest market.
Specifics:
Key attributes of the Moritex ML-M-HR lens series
Pixel size and resolving capacity
Designed for 4.5 µm pixels, the lenses may of course also be used with larger pixels, but aren’t suitable for smaller. So they are an ideal fit for Sony Pregius 3rd generation sensors.
With wide-range anti-reflective (AR) coatings, the lenses provide consistent transmission from visible (Vis) through near infrared (NIR) wavelengths, i.e. 400 ~ 1100nm.
Six member family
There are six choices in the Moritex ML-M-HR series, spanning from focal lengths 8mm – 50mm, at typical intervals. The link in the previous sentence takes you to the detailed table – and quote request buttons.
Robotics application is just an example – Courtesy Moritex
About you: We want to hear from you! We’ve built our brand on our know-how and like to educate the marketplace on imaging technology topics… What would you like to hear about?… Drop a line to info@1stvision.com with what topics you’d like to know more about
