Tutorial Archives - Page 4 of 13 - 1stVision Inc.

July 19, 2019April 12, 2023

What Are the Benefits of CMOS vs CCD Machine Vision Cameras?

Industrial machine vision cameras historically have used CCD image sensors, but there is a transition in the industrial imaging marketplace to move to CMOS imagers. Why is this?.. Sony who is the primary supplier of image sensors announced in 2015 it will stop making CCD image sensors and is already past its last time buy. The market was nervous at first until we experienced the new CMOS image sensor designs. The latest Sony Pregius Image sensors provide increased performance with lower cost making it compelling to make changes to systems using older CCD image sensors.

What is the difference between CCD and CMOS image sensors in machine vision cameras?

Both produce an image by taking light energy (photons) and convert them into an electrical charge, but the process is done very differently.

In CCD image sensors, each pixel collects light, but then is moved across the circuit via current through vertical and horizontal shift registers. The light level is then sampled in the read out circuitry. Essentially its a bucket brigade to move the pixel information around which takes time and power.

In CMOS sensors, each pixel has the read out circuitry located at the photosensitive site. The analog to digital circuit samples the information very quickly and eliminates artifacts such as smear and blooming. The pixel architecture has also radically changed moving the photosensitive electronics to be more efficient in collecting light.

6 advantages of CMOS image sensors vs CCD

There are many advantages of CMOS versus CCDs machine vision cameras outlined below:
1 – Higher Sensitivity due to the latest pixel architecture which is beneficial in lower light applications.
2 – Lower dark noise will contribute to a higher fidelity image.
3 – Pixel well depth (saturation capacity) is improved providing higher dynamic range.
4 – Lower Power consumption. This becomes important as lower heat dissipation equals a cooler camera and less noise.
5 – Lower cost! – 5 Megapixel cameras used to cost ~ $2500 and only achieve 15 fps and now cost ~ $450 with increased frame rates.
6 – Smaller pixels reduce the sensor format decreasing the lens cost.

What CMOS image sensors cross over from existing CCD image sensors?

1stVision can help in the transition starting with crossing over CCDs to CMOS using the following cross reference chart. Once identified, use the camera selector and select the sensor from the pull down menu.

1st Vision’s sales engineers have over 100 years of combined experience to assist in your camera selection. With a large portfolio of lenses, cables, NIC card and industrial computers, we can provide a full vision solution!

Ph: 978-474-0044 / info@1stvision.com / www.1stvision.com

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June 5, 2019April 5, 2023

Guide to understanding Machine Vision interface standards

Machine Vision standards have evolved providing defined models of how industrial cameras communicate to a PC allowing easier implementation of machine vision technology. Vision systems can be made up of cameras, frame grabbers and vision libraries from various manufacturers. The vision standards provides compatibility between the various manufacturers for easy implementation.

Machine vision applications require some basic tasks of finding and connecting to the cameras, configuring parameters, acquiring images and dealing with events to and from the cameras.

In order to provide cameras from various manufacturers to work together with 3rd party software and hardware from other manufacturers and provide the tasks above, a standard must be followed. “GenICam” is the basis for this standardization, providing compatibility using a Generic Transportation layer and Generic Application programming interface. These are referred to as “GenTL” and “GenAPI” respectively. GenTL provides the communication layer and GenAPI enables camera features to be configured by analyzing a compliant XML file for the camera.

Camera manufacturers however provide unique independent features providing various advantages from one to another. Creating these unique features blur the lines of the standard, not always making a camera fully compatible with another manufacturers software. For example, an industrial camera may use the GenTL layer to be recognized but may have special features making it unique as well.

This can be very confusing to understand! IDS Imaging has a white paper explaining the machine vision interface standardization, GenTL, GenAPI and the system architecture . CLICK BELOW NOW TO DOWNLOAD!

Ph: 978-474-0044 / info@1stvision.com / www.1stvision.com

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June 5, 2019May 16, 2023

What cables should I use with a machine vision camera?

While not an exact figure, we would estimate that about half our client’s problems with machine vision camera connections, dropped frames, etc. comes back to a cabling issue. This is especially true for USB and GigE cameras.

In most of these cases, the issue is that the user is using a poor/low quality cable that was not made for the high speed and/or long distance demands of the application. Most inexpensive camera cables available via mail order are not made for use in high speed highly reliable data transfer applications. If your phone isn’t transferring at the full USB3 bandwidth, you normally don’t care. You probably don’t even know. But when you purchase a high speed USB3 camera and you can’t achieve its full frame rate, or you achieve it intermittently, this becomes a big issue.

This is the reason 1stVision offers ‘machine vision/industrial’ USB3 and GigE cables. These cables are tested to specs, come with screw locks to prevent the connectors from falling out, use larger gauge wire, are over molded. They are designed to be twisted and bent (somewhat) and are industrial!

Signal amplitude (the voltage of the signal in the cable) is a function of distance and frequency for cables. For instance, Ethernet is specified to 100 meters. So your cable should work when each device is 100 meters away. However, without the proper cable, you will not maintain the full 1000 Mbits/s data transfer rate! You might only be getting 50% of the speed depending upon the distance without a high quality cable.

Finally, consider the cost if your machine vision camera is part of an instrument or product that is being sold to your clients. We see far too many clients who try to save $30 on the cable only to find out that it is costing them thousands of dollars to trouble shoot a problem that can be easily solved with the proper part. Not to mention the cost to their client when the system isn’t working, and a hit to their reputation of not building a reliable system.

Here is our advice:

If you are in an industrial setting, you are compromising the reliability and robustness of your system if you are not using an ‘industrial cable’. Even if you are not operating at maximum speed of the camera, you should have these cables. BTW, these cables are not that much more expensive mail order cables. They are in the 10’s of dollars, but not in the 1’s of dollars.
If you are using USB3 cables, you should really be using ‘industrial’ cables. Current ‘inexpensive’ USB3 cables are not reliable at over 2M, and only 1M for USB C connector types. If you are using USB3 specifically to get the higher speeds from this protocol, then you absolutely need to be using ‘industrial’ cables. Inexpensive cables are not reliable for high speed data transmission.
If you are in a lab environment, with the cable never moving, and only going a short distance, then a high quality ‘inexpensive’ Cat 6e cable will work. There is a difference between inexpensive Ethernet cables. The one that came with the security camera all folder up is NOT what you should use. A reputable mail order cable vendor selling high quality patch cables is OK.

CLICK HERE to get GigE Cable specs and get a quote

CLICK HERE for USB3 Cable specs and get a quote

Don’t be penny wise and pound foolish. At 1stVision, we offer these cables not to enrich ourselves, there is not much profit in a $30 cable, but rather to make sure our clients systems work well.

Contact us to help in the specification and providing pricing

Ph: 978-474-0044 / info@1stvision.com / www.1stvision.com

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February 20, 2019March 21, 2023

Optotune liquid lenses – 5 case examples for machine vision

Liquid lens technology, with its ability to change focus within the order of milliseconds is opening up a host of new applications in both machine vision and the life sciences. It is gaining growing interest from a wide cross section of applications and easily adapts to standard machine vision lenses.

Liquid lens technology alone provides nice solutions, but when combined with advanced controls, many more applications can be solved.

To learn the fundamentals of liquid lens technology and download a comprehensive white paper read our previous blog HERE.

In this blog, we will highlight several case application areas for liquid lens technology.

Case 1: Applications requiring various focus points and extended depth of field: This does cover many applications, such as logistics, packaging and code reading in packaging. Optotune Liquid lenses provide the ability to have pre-set focus points, auto-focus or utilize distance sensors for feedback to the lens. In the example below, 2 presets can be programmed and toggled to read 2D codes at various heights essentially extending the depth of field.

Case 2: 3D imagery of transparent materials / Hyperfocal (Extended DOF Images: When using an Optotune liquid lens in conjunction with a Gardasoft TR-CL180 controller, sequence of images can be taken with the focus point stepped between each image. This technique is known as focus stacking. This will build up a 3D image of transparent environments such as cell tissue or liquid for analysis. This can also be used to find particles suspended in liquids.

A Z-stack of images can also be used to extract 3D data (depth of focus) and compute a hyper-focus or extended depth of field (EFOF) image.

The EDOF technique requires tacking a stack of individual well focused images which have preferably been synchronized with one flash per image. An example is show below with the rendered hyper focus image shown at right.

Case 3: Lens inspection: Liquid lenses can be used to inspect lenses, such as those in cell phones for dust and scratches looking through the lens stack.

For this application, a liquid lens is used in conjunction with a telescentric lens taking images through different heights of the lens stack.

Case 4: Bottle / Container inspection: Optotune Liquid lenses can be used to facilitate image bottom’s of glass bottles or containers of various heights.

In this example, the camera is consistently at the neck of the bottle, but the bottom is at different heights.

Case 5: Large surface inspections with variation in height: Items ranging from PCB’s to LCD’s are not flat, have various component heights and need to be inspected at high magnification (typically using lenses with minimal DOF). Optotune Liquid lenses are a perfect solution using preset focus points.

Machine Vision applications using Optotune Liquid lenses and controller are endless!

These applications are just the tip of the iceberg and many more exist, but this will give you a good idea of capabilities. Gardasoft TR-CL controllers are fully GigE Vision compliant, so any compatible GigE Vision client image processing software such as Cognex VisionPro, Teledyne Dalsa Sherlock or National Instruments LABVIEW can be used easily.

Contact us to help in the specification and providing pricing

Ph: 978-474-0044 / info@1stvision.com / www.1stvision.com