What is a DMD Sensor?
A DMD sensor is a high-performance electro-optical imaging sensor. DMDs are used in various applications, including scanning laser/light ophthalmoscopy and computer-generated holography.
DMDs are micro-electromechanical systems (MEMS) that use a two-dimensional array of individually controlled aluminum micromirrors to control the direction of reflected light. They can digitally switch a light beam to represent an image pixel with a switching time of microseconds, allowing moving pictures to be displayed on a screen.
Typical setups for DMD projection involve an illumination system, a video front-end that accepts signals, and a DMD chip mounted on an electronic driver with a digital signal processor and a digital format.
DMD-based scanners are ideal for high-speed 2-dimensional confocality and spectral resolution analysis. They can also be used for imaging and tracking tasks with high accuracy and repeatability. They can also enhance optical coherence tomography and computer-generated holography performance. This is because they allow for programmable random access at the pixel level, which can be very useful in these imaging processes.
How Does a DMD Sensor Work?
DMDs (Digital Micromirror Devices) are spatial light modulators manufactured by Texas Instruments and used in many display products. They are comprised of an array of highly reflective aluminum micromirrors.
One mirror, or pixel, can be loaded with rows, blocks, or data frames. The pixel’s mechanical position is changed simultaneously with a “mirror clocking pulse,” resulting in a change of memory state from the CMOS memory below.
During dmd sensor installer, the DMD controller loads each underlying memory cell with a ‘1’ or a ‘0’ signal. A mirror reset pulse is then applied.
The resulting electrostatic deflection of the micromirror about the hinge to the +12 degree (on) or -12 degree (off) state is very repeatable. This bi-stable micromirror state allows the pixel to be programmed for grayscale patterns, RGB color image creation, and other general-purpose applications.
Alternatively, a simple switch can be implemented by tiling a set of mirrors about their respective tilt angles to produce the output beam in a specific direction. However, this simple design cannot provide any-to-any optical switching capability.
Do I Need a DMD Sensor?
The DMD chip is a 2-D array of individually addressable aluminum micromirrors that can digitally control the direction of reflected light. It’s the spatial light modulator in Texas Instruments (TI) Digital Light Processing (DLP) technology and is used primarily for business projection systems.
The DMD system consists of an illumination system, a video front-end, the chip mounted on an electronic driver, a digital signal processor, a digital format, and collection/projection optics. A single reflective mirror corresponds to a pixel on the DMD, which is a bit like a lens, but only projects one color at a time.
TI’s DMD technology allows for high-resolution moving images and a temporal duty cycle of over 1000 shades of gray. It’s used for front and rear projection and in scientific applications such as biomedical optics. It’s not as expensive as the holographic technology found in more complex systems, but it isn’t available at every home.