Customer stories

Digitizing memories

Automated feeding of slides using a compact vacuum pump

The high-quality digitization of countless motifs requires innovative technologies.

Digitize slides using vacuum technology? Rasch-Diascan preserves thousands of memories every year. Our ME 1 vacuum pump can also be used for the specially developed "Feeding system for framed slides with automation". The compact and quiet laboratory pump is ideal for this type of small-scale vacuum handling technology.

Efficient and high-quality digitization

Do you remember the time when modern digital cameras and smartphones did not yet exist and memories were captured as slides? Helmut Rasch was also a passionate amateur photographer in the 1990s and developed slide shows with live commentary. He designed these as elaborate audio-visual shows with control technology for up to 16 projectors.

Over the years, he realized that the quality of the images deteriorated over time. So Rasch tried to digitize them with a conventional scanner, but encountered a difficulty: the devices from days gone by took a considerable amount of time to digitize a single image. This was because the older line scanners laboriously scanned each image line by line. "You can imagine that scanning thousands of slides is an extremely time-consuming task if you have to wait two minutes for each one. If you then want to save time you have to opt for a lower resolution, but then the image quality inevitably deteriorates," says Rasch, describing the problem.

This gave rise to the business idea of adding a reliable autofeed system to the existing scanning technology. In 2016, the electrical engineer developed the "Feeding system for framed slides with automation", creating a way to digitize both economically and to a high standard.

Basic principle: automated feeding with vacuum handling

Handy ME 1 laboratory pump as vacuum handling technology for digitizing slides

In principle, the "feeding system for framed slides with automation" developed by Rasch is based on the clever combination of a suction gripper and a vacuum pump. The suction gripper acts like a crane, while the vacuum pump generates the vacuum required to hold the slide securely. The alternative of developing a real gripper hand as used in robotics would be much more complex and time-consuming. Vacuum handling technology presents itself here as a technically more intelligent solution.

As is usual in automation technology, a PLC (programmable logic controller) controls this operation. This transmits commands to all moving components, such as the gripper motor. Rasch has set this up with microcontrollers and a proprietary stepper motor controller.


Technical solution: Suction gripper + vacuum pump

  • Gripper head with bellows suction cup moves down and closes relatively airtight on the surface of the slide frame.
  • Solenoid valve opens so that the connected vacuum pump can generate a vacuum.
  • The slide frame is sucked in by the vacuum and adheres to the bellows suction cup.
  • Gripper head moves the slide upwards like a crane and then to the side.
  • Solenoid valve closes so that the vacuum is released and the slide falls down.
  • Slide lands in a funnel and is fed into the scanner input for digitization.


Vacuum handling with compact and quiet laboratory pump

Ideal for small systems: ME 1 vacuum pump

Which pumps are best suited for small-scale vacuum handling? Heavy industrial pumps with large motors would not only have been too loud for Rasch's office, but also completely oversized. He therefore opted for the compact ME 1 laboratory vacuum pump from VACUUBRAND. The reliability of the pump has also proven to be a significant advantage, as it can be operated for several hours without any problems.

"The compact ME 1 pump proved to be the perfect addition to our small automation system. It works quietly and efficiently – a decisive factor, as a constant noise level comparable to that of a vacuum cleaner would make working impossible. The pump demonstrated its exceptional performance with larger order volumes. There were days when it ran from 7 a.m. to 10 p.m. without interruption," reports Rasch.

Suitable pumps for vacuum handling 

To generate a holding vacuum for small items such as slides or circuit boards, single-stage diaphragm pumps with good pumping speed are sufficient. They create the necessary negative pressure to gently secure and move the parts. For this purpose, VACUUBRAND, for example, offers pumps such as the ME 1, ME 2 NT, ME 4 NT, ME 8 NT, or ME 16 NT. Advantages of these diaphragm pumps include quiet operation and oil-free construction, avoiding oil films on the workpieces.

Are you looking for a vacuum pump for your specific application? We are happy to advise you!

Universal principle for versatile use 


Helmut Rasch successfully used this automated feeding process until 2020 – but he was faced with a challenge: a variety of different slide frames from all over the world made the standardized procedure difficult. This situation motivated the electrical engineer to develop his own scanner, which now digitizes much faster using advanced infrared image technology. The resulting time savings make it possible to insert slides with different frames into the scanner by hand.

Although Rasch has switched to a manually assisted method, automated feeding remains promising. He sees the possibility of transferring the underlying concept and components to similar applications - for example in conjunction with artificial intelligence or recognition systems that identify the different slide frames.

Even more appealing for Rasch would be to adapt the principle for other applications. While the demand for digitizing slides will most likely subside within a decade, he is looking at long-term opportunities in other business areas with innovative technologies.

With the ongoing trend towards digitalization, it is becoming increasingly attractive to offer smaller automation systems. That's why compact vacuum pumps such as those from VACUUBRAND are ideal for such purposes. (Helmut Rasch)

One thing is certain: until that time comes, Rasch-Diascan will continue to preserve countless people's personal memories in a high-quality way. For example, a professionally digitized slide helped a customer to achieve first place in a photography competition, where it was up against images from modern digital cameras. True to the motto: Preserve tradition, dare to be modern!