Teledyne Line Scan Cameras: Our Expert Review

Teledyne is the largest line scan camera manufacturer in the world. When we tell customers that, the usual response is a question. If they make so many, which one do I actually need? That is the problem with a range this deep. The choice is not obvious. Picking the wrong family is an expensive mistake to make on a production line.

We work across the Teledyne line scan range and know the cameras well. We help OEMs and system integrators design them into their systems. This review is what we have learned. It covers what each family is genuinely for, where it fits, where it does not and who should buy it. We carry Teledyne alongside other manufacturers. This is a considered view of the range rather than a sales pitch for it.

First, a note on what line scan is for. A line scan camera typically captures a single row of pixels at a time and builds an image as the product moves past it. Some advanced sensors, TDI models among them, use several rows to gather more light. The idea is the same. That makes it the right tool for anything continuous. A web of material, a print run, a conveyor of product with no natural start or stop. It gives you very high resolution across the width of a moving web without the seams you would get from stitching area scan images together. If your product moves continuously and you need to inspect all of it, line scan is usually the answer.

The applications line scan is built for

Web inspection. This is the classic line scan job. Paper, film, foil, textiles, nonwovens, any material produced as a continuous web. The camera images the full width as the web runs, catching defects like holes, streaks, coating flaws and contamination at production speed. Area scan cannot do this without gaps. Line scan is the standard tool.

Print and label inspection. High-speed print needs every unit checked. Print runs fast. A line scan camera reads the printed web continuously, verifying registration, colour and print quality without slowing the press. The colour families are built for exactly this.

Continuous process and conveyed product. Anywhere product runs past on a belt with no fixed frame, line scan gives you uniform, high-resolution imaging along the whole length. Food sorting, recycling streams and sheet goods all fall here. The image is as long as the product, which suits inspection that has to cover everything rather than sample it.

Cylindrical and rotating parts. A part that rotates past the camera unwraps into a flat line scan image of its whole surface. That makes line scan useful for inspecting the outside of cans, bottles and other round objects where an area scan camera would only ever see one face.

The Teledyne line scan range, family by family

Teledyne splits its line scan cameras into families that step up in speed, resolution and cost. Here is what each one is for. The table below summarises them, then we go through each in turn.

Tetra. The newest and most cost-effective family. Tetra uses Teledyne's latest CMOS line scan sensor over a 2.5 or 10 GigE Vision interface. It needs no frame grabber. Resolutions run 2k to 8k with line rates to around 165 kHz on the faster mono models. This is the family to start with when the application is straightforward and budget matters. It is often all a simpler line needs.

Linea Lite. Also aimed at accessibility, Linea Lite is compact and cost-effective. It comes in 2k, 4k and 8k, mono and colour, with line rates from 12.5 to 50 kHz over a GigE Vision interface. It suits simpler inspection tasks where you want proven Teledyne imaging without paying for speed you will not use.

Linea. The mainstream workhorse. Linea offers mono and colour from 2k to 16k, with line rates to 80 kHz on GigE using Teledyne's TurboDrive technology. Interfaces are GigE and Camera Link. TurboDrive lets the GigE models run several times faster than plain GigE would allow with no change to your network. For most web and print inspection, Linea is the sensible default. Its colour option holds image quality well for the price.

Linea2. A step up in bandwidth and sensor capability. Linea2 delivers five times the bandwidth of the Linea family over a 5GigE interface, again with no frame grabber. Its real distinction is the sensor. It comes as a trilinear colour model or a quadlinear multispectral model that captures RGB plus NIR in a single pass, at 4k resolution with line rates around 30 to 40 kHz. That multispectral capability suits print inspection, food sorting and recycling, where seeing beyond visible colour catches things a standard colour camera misses.

Linea ML. This is where Teledyne moves into multi-line TDI CMOS. Linea ML uses a multi-array charge-domain CMOS sensor over Camera Link HS to reach high resolution at high speed, with models running 8k to 16k at up to 300 kHz and strong dynamic range in a compact housing. TDI builds sensitivity by summing multiple exposures of the same line. Linea ML earns its place when the line is fast and the light is limited, a common combination in real factories.

Linea HS and HS2. The top of the range. These are multi-array charge-domain CMOS TDI cameras for the highest-speed, lowest-light work. Linea HS reaches 16k resolution at up to 300 kHz. The newer Linea HS2 pushes a 16k sensor to a 1 megahertz line rate, which is 16 gigapixels per second and makes it the first 16k TDI camera to reach that speed. Both use Camera Link HS and pair with Teledyne's Xtium series frame grabbers. This tier is for demanding inspection at extreme speed, such as high-resolution web inspection where nothing slower will keep up.

AxCIS. The one that does not look like the others. AxCIS is a fully integrated contact image sensor module. Sensor, lenses and lighting are built into a single unit. There is no separate optics or illumination to align. It installs with no complex alignment or calibration. It fits where vertical clearance is tight and connects over a Camera Link HS fibre interface. Models reach very wide resolutions, up to 28k across the scan. For a wide web where integration time and repeatable setup matter more than optical flexibility, AxCIS removes most of the work. The trade-off is that you take the built-in optics as they come.

The limitations, stated plainly

Line scan is powerful. It is not the answer to everything. These are the constraints to weigh before you commit. They apply to any line scan camera, Teledyne or otherwise.

It needs motion. That motion must be controlled. A line scan camera only builds an image if the product moves past it. The image quality depends on that movement being even. You need an encoder to synchronise the camera to the actual line speed, because any variation in speed stretches or squashes the image. If your product is stationary, or the motion is not controlled, line scan is the wrong choice and an area scan camera is simpler.

It is demanding on lighting. A line scan camera collects light for only a very short time on each line. It needs bright, uniform illumination focused precisely on the scan line. Lighting a line scan system well is harder than lighting an area scan one. It is where many line scan projects struggle. It is worth getting the lighting designed properly from the start.

The faster tiers need frame grabbers and more system. Tetra and the GigE families keep it simple with no frame grabber. The high-speed TDI families do not. Linea HS and HS2 need a Camera Link HS frame grabber from Teledyne's Xtium series, the right cabling and in some cases liquid cooling. That is more cost and more integration, which is justified at high speed but is not free.

Alignment and setup take skill. Except for the integrated AxCIS, a line scan system needs the camera, lens and lighting aligned accurately to the scan line. The optics have to be chosen correctly for the working distance and resolution. This is not difficult for an experienced integrator. It is genuinely fiddly the first time. It is a large part of why line scan projects benefit from engineering support.

Who should buy Teledyne line scan

Teledyne line scan is the right choice if you recognise your application in this list.

You inspect a continuous web or a fast print run. This is the core case. If you produce material as a web or print at speed and need to inspect all of it, Teledyne line scan is a proven and well-supported choice. There is a family to match almost any speed and resolution.

You need very high resolution across a wide product. Line scan gives you resolution across the full width that area scan cannot match without stitching. If you are inspecting a wide web to a fine specification, this is the technology. Teledyne reaches the highest resolutions available.

You have fast lines in difficult light. If your line is quick and the light is limited, the TDI families, Linea ML and Linea HS, are built for exactly that. Few competitors match them at the top end.

You want the depth of one manufacturer's range. Because Teledyne makes its own sensors and covers everything from a simple GigE camera to a megahertz TDI camera, you can move up the range as your requirements grow without changing supplier or software. That consistency has real value over the life of a line.

Who should look elsewhere

Line scan is the wrong tool for a good number of applications. It is worth being clear about them so you do not buy it by mistake.

Your product is stationary or discrete. If you inspect parts that sit still, or arrive one at a time with a natural start and stop, an area scan camera is simpler, cheaper and easier to light. You do not need line scan to check a part that is not moving. Forcing it in adds cost and complexity for nothing.

You cannot control the motion. Line scan depends on even, encoded motion. If your product moves unpredictably, or you cannot fit an encoder, the image will not hold together. An area scan camera does not care about motion in the same way and will serve you better.

Your application is simple and low speed. If the task is basic, presence, a barcode, a single feature on a slow line, a standard area scan camera or a smart camera will do it for less money and less setup. Line scan is worth its cost when you need what it uniquely offers, not as a default.

You need temperature or 3D. Line scan is a 2D reflected-light technology. If you need to measure temperature, a thermal camera is the tool. If you need height or shape, a 3D profiler such as Teledyne's own Z-Trak is the right choice. Do not reach for line scan for a job it is not built to do.

The verdict

Teledyne line scan is as strong as its reputation. The depth of the range is the point. From the cost-effective Tetra to the megahertz Linea HS2, there is a family for almost any continuous inspection task. Because Teledyne makes its own sensors, the image quality is consistent across the range. For web inspection, print and continuous process work, it is a safe and capable choice.

The harder part is not the camera. It is choosing the right family, designing the lighting and setting the system up correctly. That is the work that decides whether a line scan project succeeds. It is the part we spend most of our time on. If you are weighing line scan for an application, the fastest way to know if it fits is to see it running on your product.

Request a line scan demo: get in touch with our engineers

Get in touch: info@clearview-imaging.com | +44 (0)1844 217270

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