Tofra Inc., has provided microscope automation hardware and software since 1993. As with many applications, the amount of physical space available to accommodate a product continues to shrink. That’s one of the reasons Ilya Ravkin, president, turned to All Motion Inc. for his company’s new generation of products with built-in controllers.
The new Focus Drive with Integrated Controller uses a step motor from AllMotion to manage a microscope’s optical light filters. The Focus Drive unit also includes the motor controller, an adapter that fits over the coarse focus knob of the microscope, and a custom cable that simplifies connection.
The step motor mounts through a flexible coupling directly onto the microscope’s fine-focus shaft, which is connected to the filter wheel. The filter wheel changes the filters in the excitation and emission light paths. On some microscopes, this wheel can be mounted in the transillumination light path. If power is removed from the wheel, engineers may manually position filters.
The coupling delivers high torsion stiffness, which eliminates backlash. The 1-µm step from the motor enables fast computer-controlled switching of either twelve 25-mm diameter filters or ten 32-mm diameter filters. Typical time required to switch between adjacent filters is less than 200 ms.
As part of the automated system, the filter wheel is 17 mm thick with a housing dimension of 180 mm. Mounted on the front of the wheel is a knob with numbers corresponding to the current active filter. No additional control units are needed, reducing the amount of desk space it needs. The custom cable connects the wheel directly to a computer through a serial port, USB port, or USB-to-serial converter.
The wheel can be daisy-chained with other filter wheels, focus drives, and stages, creating an automated microscope system. The cable carries only direct current and communications signals minimizing electromagnetic interference.
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