Micromirror devices are devices based on microscopically small mirrors. The mirrors are microelectromechanical systems (MEMS), which means that their states are controlled by applying a voltage between the two electrodes around the mirror arrays. Digital micromirror devices are used in video projectors and optics and micromirror devices for light deflection and control.
Digital Micromirror Devices (DMD) were invented by Texas Instruments in 1987 and are the core of the DLP technology used for video projection. The mirrors are arranged in a matrix and have two states, "on" or "off" (digital). In the on state, light from the projector bulb is reflected into the lens making the pixel appear bright on the screen. In the off state, the light is directed elsewhere (usually onto a heatsink), making the pixel appear dark. Colours could be produced by various technologies like different light sources or gratings.
The mirrors could not only be switched between two states, their rotation is in fact continuous. This could be used for controlling the intensity and direction of incident light. One future application is controlling the light in buildings, based on micromirrors between the two panes of Insulated glazing. The power and direction of the incident light is determined by the mirrors state, which itself is controlled electrostatically. [1]
A MEMS scanning micromirror consists of a silicon device with a millimeter-scale mirror at the center. The mirror is typically connected to flexures that allow it to oscillate on a single axis or biaxially, to project or capture light. [2]
MEMS is the technology of microscopic devices incorporating both electronic and moving parts. MEMS are made up of components between 1 and 100 micrometres in size, and MEMS devices generally range in size from 20 micrometres to a millimetre, although components arranged in arrays can be more than 1000 mm2. They usually consist of a central unit that processes data and several components that interact with the surroundings.
Liquid crystal on silicon is a miniaturized reflective active-matrix liquid-crystal display or "microdisplay" using a liquid crystal layer on top of a silicon backplane. It is also known as a spatial light modulator. LCoS initially was developed for projection televisions, but has since found additional uses in wavelength selective switching, structured illumination, near-eye displays and optical pulse shaping.
A video projector is an image projector that receives a video signal and projects the corresponding image onto a projection screen using a lens system. Video projectors use a very bright ultra-high-performance lamp, Xenon arc lamp, metal halide lamp, LED or solid state blue, RB, RGB or fiber-optic lasers to provide the illumination required to project the image. Most modern projectors can correct any curves, blurriness and other inconsistencies through manual settings.
Digital light processing (DLP) is a set of chipsets based on optical micro-electro-mechanical technology that uses a digital micromirror device. It was originally developed in 1987 by Larry Hornbeck of Texas Instruments. While the DLP imaging device was invented by Texas Instruments, the first DLP-based projector was introduced by Digital Projection Ltd in 1997. Digital Projection and Texas Instruments were both awarded Emmy Awards in 1998 for the DLP projector technology. DLP is used in a variety of display applications from traditional static displays to interactive displays and also non-traditional embedded applications including medical, security, and industrial uses.
A spatial light modulator (SLM) is a device that can control the intensity, phase, or polarization of light in a spatially varying manner. A simple example is an overhead projector transparency. Usually when the term SLM is used, it means that the transparency can be controlled by a computer.
A handheld projector is an image projector in a handheld device. It was developed as a computer display device for compact portable devices such as mobile phones, personal digital assistants, and digital cameras, which have sufficient storage capacity to handle presentation materials but are too small to accommodate a display screen that an audience can see easily. Handheld projectors involve miniaturized hardware, and software that can project digital images onto a nearby viewing surface.
The screen-door effect (SDE) is a visual artifact of displays, where the fine lines separating pixels become visible in the displayed image. This can be seen in digital projector images and regular displays under magnification or at close range, but the increases in display resolutions have made this much less significant. More recently, the screen door effect has been an issue with virtual reality headsets and other head-mounted displays, because these are viewed at a much closer distance, and stretch a single display across a much wider field of view.
The grating light valve (GLV) is a "micro projection" technology that operates using a dynamically adjustable diffraction grating. It competes with other light valve technologies such as Digital Light Processing (DLP) and liquid crystal on silicon (LCoS) for implementation in video projector devices such as rear-projection televisions. The use of microelectromechanical systems (MEMS) in optical applications, which is known as optical MEMS or micro-opto-electro-mechanical structures (MOEMS), has enabled the possibility to combine the mechanical, electrical, and optical components in tiny-scale.
Laser color television, or laser color video display, is a type of television that utilizes two or more individually modulated optical (laser) rays of different colors to produce a combined spot that is scanned and projected across the image plane by a polygon-mirror system or less effectively by optoelectronic means to produce a color-television display. The systems work either by scanning the entire picture a dot at a time and modulating the laser directly at high frequency, much like the electron beams in a cathode ray tube, or by optically spreading and then modulating the laser and scanning a line at a time, the line itself being modulated in much the same way as with digital light processing (DLP).
A MEMS electrothermal actuator is a microelectromechanical device that typically generates motion by thermal expansion. It relies on the equilibrium between the thermal energy produced by an applied electric current and the heat dissipated into the environment or the substrate. Its working principle is based on resistive heating. Fabrication processes for electrothermal actuators include deep X-ray lithography, LIGA, and deep reactive ion etching (DRIE). These techniques allow for the creation of devices with high aspect ratios. Additionally, these actuators are relatively easy to fabricate and are compatible with standard Integrated Circuits (IC) and MEMS fabrication methods. These electrothermal actuators can be utilized in different kind of MEMS devices like microgrippers, micromirrors, tunable inductors and resonators.
Large-screen television technology developed rapidly in the late 1990s and 2000s. Prior to the development of thin-screen technologies, rear-projection television was standard for larger displays, and jumbotron, a non-projection video display technology, was used at stadiums and concerts. Various thin-screen technologies are being developed, but only liquid crystal display (LCD), plasma display (PDP) and Digital Light Processing (DLP) have been publicly released. Recent technologies like organic light-emitting diode (OLED) as well as not-yet-released technologies like surface-conduction electron-emitter display (SED) or field emission display (FED) are in development to supersede earlier flat-screen technologies in picture quality.
Interferometric modulator display is a technology used in electronic visual displays that can create various colors via interference of reflected light. The color is selected with an electrically switched light modulator comprising a microscopic cavity that is switched on and off using driver integrated circuits similar to those used to address liquid crystal displays (LCD). An IMOD-based reflective flat panel display includes hundreds of thousands of individual IMOD elements each a microelectromechanical systems (MEMS)-based device.
A structured-light 3D scanner is a 3D scanning device for measuring the three-dimensional shape of an object using projected light patterns and a camera system.
Wavelength selective switching components are used in WDM optical communications networks to route (switch) signals between optical fibres on a per-wavelength basis.
A LED display is a flat panel display that uses an array of light-emitting diodes (LEDs) as pixels for a video display. Their brightness allows them to be used outdoors where they are visible in the sun for store signs and billboards. In recent years, they have also become commonly used in destination signs on public transport vehicles, as well as variable-message signs on highways. LED displays are capable of providing general illumination in addition to visual display, as when used for stage lighting or other decorative purposes. LED displays can offer higher contrast ratios than a projector and are thus an alternative to traditional projection screens, and they can be used for large, uninterrupted video walls. microLED displays are LED displays with smaller LEDs, which poses significant development challenges.
An electronic visual display is a display device that can display images, video, or text that is transmitted electronically. Electronic visual displays include television sets, computer monitors, and digital signage. They are ubiquitous in mobile computing applications like tablet computers, smartphones, and information appliances. Many electronic visual displays are informally referred to as screens.
The digital micromirror device, or DMD, is the microoptoelectromechanical system (MOEMS) that is the core of the trademarked Digital Light Processing (DLP) projection technology from Texas Instruments (TI). Texas Instrument's DMD was created by solid-state physicist and TI Fellow Emeritus Dr. Larry Hornbeck in 1987. However, the technology goes back to 1973 with Harvey C. Nathanson's use of millions of microscopically small moving mirrors to create a video display of the type now found in digital projectors.
MicroTiles are discontinued modular rear projection cube units designed, developed and marketed by Christie Digital. The building-block nature of the system made the configuration of the overall screen area and shape flexible. This allowed for simple traditional rectangular displays, and more complex non-standard shapes.
A microscanner, or micro scanning mirror, is a microoptoelectromechanical system (MOEMS) in the category of micromirror actuators for dynamic light modulation. Depending upon the type of microscanner, the modulatory movement of a single mirror can be either translatory or rotational, on one or two axes. In the first case, a phase shifting effect takes place. In the second case, the incident light wave is deflected.
Projection micro-stereolithography (PμSL) adapts 3D printing technology for micro-fabrication. Digital micro display technology provides dynamic stereolithography masks that work as a virtual photomask. This technique allows for rapid photopolymerization of an entire layer with a flash of UV illumination at micro-scale resolution. The mask can control individual pixel light intensity, allowing control of material properties of the fabricated structure with desired spatial distribution.