A translation stage with a motor is a precision mechanical device used in motion control applications that allows for precise linear movement along single or multiple axes. The motor is used to drive the translation stage, providing smooth and precise motion control. Translation stages with a motor are commonly used in scientific research, bio-medical, life sciences, metrology, semiconductor, precise manufacturing, and other industries where precise positioning is required.

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The best way to determine the resolution of an optical system is to test it directly using MTF testing. One can purchase expensive MTF testers or pay someone to do the testing, but we like cost effective methods. Read below to learn more about MTF testing and an inexpensive testing method we’ve developed.

Using a linear motor is generally considered to be optimal for high speed motion systems and is the most precise and repeatable linear motion actuation technology.

The simplest possible point source is a laser diode module. You can buy an inexpensive one with a driver circuit on Ebay for less than $10. High power is undesirable and may damage the camera; 5mW is plenty. I power my laser diode with a lab power supply, but you can run the module off of batteries. One thing to verify before you buy is whether you can remove the collimating lens from the module – you’ll need to do this for a point source. If your lens needs to be tested with collimated light, you’re better off buying a high quality collimating lens from a supplier like Edmund Optical, Thorlabs, or Newport. Just make sure the lens diameter is larger than the entrance pupil of the lens you’re testing. One problem with lasers is that they emit coherent light, which causes problems if you want to measure incoherent (normal) MTF. The solution to this is to limit the current to the laser diode so it is below threshold and emits spontaneous (incoherent) light rather than stimulated (coherent) light.

If you want to measure lenses with high MTF, a bare laser diode module might not be enough. They tend to be expensive, but a spatial filter will refocus the laser through a pinhole and assure you of a high quality point source. If you want to know what size pinhole to use for the spatial filter, the diameter should be

A motorized stage is a high-performance positioning system that utilizes integrated motors to drive a platform with exceptional accuracy along one or more linear axes. These stages are instrumental in various automated applications across science and industry, particularly those requiring meticulous object manipulation.

Our screw driven motorized stages range from stages with monolithic integrated XY centers to low-cost, single axis stages with crossed roller ways and stepper motors.

FOV and focal length

Once the payload has been constrained to a single degree of freedom, the system’s next mission is to actuate the payload and provide precise incremental linear motion along the guideway.

Drive Mechanism: The drive mechanism transmits the motion from the motor to the stage platform. It can be a screw drive, belt drive, or direct drive system.

A motorized stage with a linear motor requires a linear feedback device as well as a servo drive and control to close a position feedback loop. With a high-resolution linear encoder, linear actuators can provide position control down to the nanometer level. A typical application for high precision linear actuators is to control the focus of a microscope objective in a digital imaging system.

A motorized stage is a device used in various life science applications to move objects in a controlled and precise manner. The motorized stage consists of a platform that can be moved along one or more axes using motors and mechanical components.

The SmartStage™ XY motorized stage features a built-in motion controller, ONE external cable and has a 5 nm resolution with 0.8 um bi-directional repeatability.

A motorized optical stage is a stage that is designed for use with optical instruments such as microscopes or cameras and is moved by a motor. It provides precise control over the position and movement of samples and optical components. The motorized optical stage has higher precision and accuracy requirements than the general motorized stage, as the movement of the sample or component needs to be very precise for accurate imaging or analysis. Some motorized optical stages have additional features such as encoder feedback for closed-loop control, joystick or computer control, and programmable motion profiles, which are specific to optical applications.

Our direct drive linear motor stages include linear servo motors and offer higher speed, acceleration, and accuracy than belt-drive, lead screw, or rack and pinion actuators.

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Controller: The controller is responsible for controlling the motor's speed, acceleration, and position. It receives input signals from sensors and actuators and generates appropriate control signals to achieve the desired motion.

Dover Motion's motorized stages include motorized translation stages with up to 635 mm of travel, XY tables, vertical Z stages, and microscope stages. Each motorized stage features stepper and servo single and multi-axis motors, built-in motion controllers, and optimal travel time for precision motion. As a leader in creating motion solutions for the life sciences industry, we also specialize in manufacturing standard and custom motorized optical stages that meet higher precision and accuracy requirements for use with optical instruments, including microscopes and cameras.

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As always, we’re interested in finding creative ways to solve complicated (or expensive) problems. If we can help you with your next project, let us know!

The next problem is how to do this cost effectively. Have you heard about the Raspberry Pi educational computer? You can purchase one for $35 and add a camera for another $30. Even with the SD card, wireless network adaptor and so on, your investment should be under $100. Unless you already have the parts handy, it will probably cost more for an optical rail and the parts to hold the lens, camera, and point source than it does for the camera to do the job. The Raspberry Pi camera has 1.4 micron pixels, so it has enough resolution to test up to 180 cy/mm, which is plenty for most lenses. All you have to do is remove the lens from the camera (just as you would do for the resolution chart tester) and figure out how to hold the camera and Pi. We built a custom holder with an M4 thread for mounting to a post. Here is a picture of our setup:

Motor: The motor is the driving force behind the stage's movement. It converts electrical energy into mechanical energy to move the stage platform.

Motorized stages play a critical role in achieving high accuracy and efficiency in various applications, from scientific research to industrial automation. Yet, information on choosing the right motorized stage is not widely accessible. Our guide aims to provide a comprehensive overview, addressing common questions and highlighting key features to help you select the stage that best fits your application.

Our Z stages offering includes traditional Z stages for objective focusing and Z stages for sample positioning or Z-Lift stages .

Modulation transfer function

Our microscope stages are made with embedded high-performance precision electronics required to control motion within the stage without increasing its size.

At Dover Motion, we specialize in designing and manufacturing motorized optical stages that meet the highest standards of accuracy and reliability. Our stages are designed to deliver smooth, stable motion with sub-micron positioning accuracy, even in harsh environments or challenging applications. They range from single-axis stages for simple applications to multi-axis systems for complex processes and are available in a variety of sizes and configurations, with options for linear or rotary motion. Our experienced team of engineers works closely with our customers to understand their specific requirements and design custom motorized optical stages that are tailored to their unique needs.

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Sensors: Sensors are used to measure the stage's position, velocity, and acceleration. They provide feedback to the controller, allowing it to maintain precise control over the stage's movement.

Our XY tables include high performance, open frame, monolithic high load, and custom designed XY tables that move in two degrees of freedom and offer high precision and efficiency for digital imaging applications.

Linear motor stages offer higher speed and precision, while screw-driven stages are more cost-effective and suitable for less demanding applications.

The motorized stage provides precise automated positioning and is available in single or multi-axis architectures. It is also commonly referred to as a motorized table or motorized actuator.  Each axis of a motorized stage must constrain the six degrees of freedom (X, Y, Z, roll, pitch, and yaw) of the payload to only one, producing automation along a single axis of motion. This is accomplished with a set of linear bearings, which are mounted to a metal base to provide a stiff structure.  Our stages designed specifically for vertical motion can be viewed on our Z Stages page.

Let’s start with the theory behind MTF testing. The basic idea is that the MTF of an optical system is a slice through the Fourier transform of the point spread function. Too much jargon? OK, let’s break it down. If you have not yet learned about MTF, please read our page on MTF and then come back. Next, a Fourier transform is a somewhat complicated mathematical operation. When performed by a computer, it is typically called an FFT (fast Fourier transform). Finally, the point spread function is just the image of a point source (like a star) formed by the lens. So all we have to do to measure MTF is take a high resolution picture of the image of a point source, take a cross-section of it (horizontal or vertical to make it easy), and have a computer do an FFT.