2016 New Research Project for STVision

New Research Project for STVision

The R&D Project “PhotoEnco” is the development of a new generation of encoder discs for increasing demands in the market. Targets are simplified assembly without calibration, a higher resolution with improved accuracy, and a reduction of cost.
The PhotoEnco team consists of five partners under the leadership of Sick Stegmann. Responsibility of STVision is the development of visual inspection tools for quality control of the new generation encoders. This will guarantee good and constant quality production of the new encoders from the first day on. STVision was selected by the team, due to 12 years experience in the 100% inspection of glass and Nickel encoder discs.
The project is scheduled for three years, beginning in June 2016.

The project is financed by the BMBF
(Bundesministerium für Bildung und Forschung)

DLC Crack Inspection

  1. May 2016

STV has developed a vision system for the detection of micro cracks on DLC (diamond like coated) needles for Diesel injection nozzles. The needles are the valves of Common Rail Diesel Engines, used everywhere across the world.
Micro cracks occur randomly in the manufacturing process. They are almost invisible and extremely hard to detect. STV has developed a method for safe automatic inspection. The system executes crack inspection within 2 sec cycle time by means of special optical illumination, specific filtering in software, and defect cluster analysis.
The micro cracks can cause certain failures of the Diesel engine injection control, due to incomplete blocking and leaking of the valves. Bosch now uses this system in the 100% quality test of their diesel nozzles.

inspection system of steel needles with DLC (diamond like coating) surfaces for general surface defects.
New generation optical inspection system for power shunt resistors with new generation cameras with higher resolution and speed.

2015 Inspection system for jet holes on Diesel

Inspection system for jet holes on Diesel injection nozzles. Measurement of tip shape, and test for false shape types.
Optical test of steel needles with DLC (diamond like coating) surfaces for micro cracks.
2nd generation system for optical inspection on electroformed encoder discs with fully automatic handling.

2013 STV has developed a very high speed

STV has developed a very high speed inspection system for optical density and position measurement of thin film material.

STV accepts partnership for participation in a BMFT research project for the next generation high definition rotary encoder inspection.

2012 STV develops a large inspection area system for metal sheets.

STV develops a large inspection area system for metal sheets. The active area for inspection is 540×540 mm. The sheet is placed on a glass table, and inspection is executed for contour geometry measurement in backlight, as well as surface inspection with different top illumination options. The system first application is for nickel sheets of size 300×300 mm, which contain inkjet nozzle plate units. The system is equipped with a motor zoom, dual cameras, and measures holes in metal sheets of typically 15-30 micron diameter, with accuracy of better than 1 micron, and repeatability 0.05 micron. Nozzles of size down to 4 micron have successfully been measured.

2011 STV develops and produces systems for metal

STV develops and produces systems for metal surface and contour inspection. The cameras are integrated in complete modules, for device sizes up to 100 mm. The components are processed in automatic handlers, and exposed to the camera unit. The system can measure various dimensional parameters, e.g. diameters, hole positions and sizes, orientation in backlight illumination. Also the system executes surface inspection on noisy surfaces, e.g. sanded copper or manganin, from stamped material or electric welding.


STV has built inspection modules to be integrated into older generation Systemation handlers for the semiconductor industry. Those handlers exist in large numbers, many of them being still operable, and they are frequently used to tape new generation sensor components. These devices have special features, which are not supported in the Systemation camera system. Therefore, STV can replace these cameras, and enable the handlers to tape and inspect these components without facing the high cost of new generation tape & reel handlers.

2007 / STB2 Illumination

STB2 Illumination

STV introduces a new generation of illumination hard and software for industrial inspection. The system generates strobe light pulses for up to eight different illumination units. These may be top light, ring light, side light bars, or any other illumination device, based on LED technology. The LED switch very fast (in the range of microseconds), are free of maintenance and repair for many years. Today there are many high power LED on the market, which allow very bright intensity and extremely short pulses.

For example, STV uses this for illumination of inkjet nozzle plates in high speed continuous grab. Up to 15 high resolution images per sec are digitised, while the target is moving constantly. Holes as small as 4 micron diameter in the metal are measured with repeatability of around 0.1 micron. The camera is high resolution 1380 x 1040 pixel, and the motion has the speed of around 20 000 pixel per second. So within 50 microseconds, the target moves at about 1 pixel. And if you want a jitter free crisp image, the strobe light must be better than ¼ pixel diameter, so 12.5 microseconds.

The STB2 hardware allows programmable pulses between 2.5 nanoseconds and 15 milliseconds, spreading a range of almost six decades. Longer strobe pulses generate more light, of course, but the danger of motion effects increase.

The system generates up to eight independent outputs. They are all flashing with the same timing, same pulse length. But they can be programmed for individual brightness. Each pulse is current control logic. This assures that a definite amount of current is pumped into the LED device, independent of its internal voltage threshold. This assures very stable and identical brightness between channels.

Each channel output current is controlled via 14 bit D/A converter and high speed operational amplifier.

The system is an external USB programmable unit. Setup or chage of programming is within few msec USB speed. Strobe trigger is via camera signal, so the pulses are hardware synchronized to the camera image exposure. Multiple synchronous cameras are supported.

The system has unparalleled performance in pulse duration and light intensity stability. It is used to inspect inkjet nozzle holes at a magnification of 0.8 micon per pixel on the fly (moving target), and the measurement repeatability as well as long term stability of the illumination is as good as 0.1 micron hole diameter for any holes of diameter between 4 and 60 micron.

STV introduces the first software to vectorize CPU intense functions. The algorithms are splitted into balanced parallelthreads which are processed by the multiple CPU’s of the Core 2Duo or the new 4-CPU cores in parallel and enhances speed by up to a factor of 4! This is specially useful in the die surface inspections and applies on all types of imaging sensor.