Climate-Controlled, Immersive Display
novel enclosure is integrated around a flat panel video display. The enclosure has a
"window" in front fitted with a flat magnifying element such as a
Fresnel lens to create (or suggest) an infinity-focus effect. The enclosure
also has sides that isolate and ventilate the air inside to eliminate heat from
the display and to provide climate control for the viewers. The enclosed
display may serve as a module that can be displayed together with other modules
as a larger, orthoscopically correct, immersive display (and one where a larger, magnified image and drastically reduced mullions are "free"). A more advanced embodiment
additionally integrates stereoscopic 3D, both for far-field 2D imagery and for
mixed near-field and far-field stereoscopic imagery.
(Interval Research Corporation, UNESCO World Heritage Centre, photo: Theo Westenberger)
Making a "far-field" display for viewing landscapes may therefore engage these three elements: orthoscopic correctness, "infinity focus" accommodation, and "zero convergence" stereoscopic 3D with identical images seen by both eyes. Our eyes (and therefore our selves) feel it when these elements are properly engaged. But anecdotal experience suggests that each have a degree of tolerance or "wiggle room".
1.1.1 Orthoscopic Correctness
"Karlsruhe Moviemap", interactive art installation, Siggraph 1991, Las Vegas
(ZKM Centre for Arts and Media)
The "Kalrsruhe Moviemap," an interactive art installation filmed from a tram, was shot with a wide-angle lens with a horizontal field of view (FOV) just under 90 degrees. The user interaction occurred from a platform with a lever and foot switches, as well as an overview "you-are-here" map display, which could be placed in front of the screen to replicate the orthoscopically correct FOV. But it was found that "having it roughly close" was good enough. For example, as shown at Siggraph 1991, the horizontal FOV approximated 60 degrees rather than 90 degrees, but given that the display still appeared "bigger than normal," the suggestion of orthoscopic correctness was convincing.
1.1.2 Infinity Focus Accommodation
Karlsruhe Moviemap displayed through an infinity focus "window" (behind a map display and control unit),
Exploratorium 1992, San Francisco
The Karslruhe Moviemap was often exhibited with the display approximately 20 feet away from the input platform, enough for the viewers' eyes to accommodate close to infinity. But it was exhibited at the Exploratorium in 1992 using a consumer sized rear-projection television behind a wall with a rectangular window cut out of it. The window was fitted with a flat lenticular magnifying lens. The television was less than 12 inches behind the lens which not only magnified but altered the accomodation of viewers' eyes to appear close to infinity. This could be confirmed by placing a camera with a calibrated manual focusing lens where viewers stand, focusing on the television, then reading the lens setting.
Viewers stood directly in front of the window, usually no more than one or two feet away. Even though their eyes were converging rather than parallel, the "infinity focus" effect was prominent. Several viewers asked if it was a "holographic" display.
The use of magnifiying optics naturally increases the image size but also "re-places" the image to appear further away, in terms of accommodation. Before the advent of large flat magnifiying lenses such as Fresnels, the flight simulator industry sometimes used a concave mirror to achieve the same effect.
Additionally, placing the display behind a wall may mask the edges of the display and, by having the screen seen in direct comparison with something closer (the wall), enhances the illusion that it is "further back." Special effects producer Douglas Trumbull used this "further back" effect by building overhanging frames in front of his special-venue 70mm "Showscan" theater screens.
1.1.3 "Zero convergence" stereoscopic 3D
Timbuktu, from Be Now Here, Yerba Buena Center for the Arts, San Francisco, 1995
"Be Now Here", a stereo-panoramic art installation, was filmed with a slowly rotating pair of stereoscopic cameras. The installation consisted of a cylindrical room with a stereoscopic screen and a slowly rotating floor (in sync with the cameras). Though much of the imagery included near-field material, such as the boy pictured above, a considerable amount of the imagery was strictly far-field, with essentially identical views for both eyes. The left and right views were calibrated to display zero convergence for far-field imagery (by displacing such imagery ~2.5 inches, the average human interocular distance). It was found that viewers could walk up to the rail, approximately three feet from the screen, and still feel as though their eyes were gazing far away, even without proper infinity focus accommodation.
Be Now Here installation at Art Center College of Design, Pasadena, 2005
Be Now Here consisted of a
relatively small enclosed space, a 16 foot diameter cylindrical room with black
curtains around most of it except for the screen. Its capacity during pubic
exhibitions was generally limited to ten viewers. It was found that the use of
climate control fans made a huge difference for the user experience; without
them the space was uncomfortably hot and stuffy. Enhancing the physiology of
the viewers enhanced their psychology with respect to their experience.
1.3 Modularity –
Dubrovnik, from "Be Now Here Triptych", Helen Lindhurst Gallery, USC, Los Angeles, 2008
(USC School of Cinematic Arts and Ars Electronica Linz)
Be Now Here, as an art installation with a cylindrical room and a rotating floor, weighed over 4,000 pounds and required several human-days to install. In 2008, when stereo3D-capable "DLP" consumer projection televisions became available, the same footage was used to make a 180 degree, 3-screen triptych. The use of modular displays to build a panorama meant that "mullions", the black vertical spaces between the displays, would be visible. Generally speaking, it was found that mullions were perceptually inconsequential, while the practicality of a smaller, modular immersive system made good sense.
This invention integrates a climate-controlled enclosure around a flat panel video display. The enclosure has a transparent "window" in front allowing the display to be seen. The window may be fitted with a flat magnifying element such as a Fresnel or holographic magnifying lens to create an infinity-focus effect. The enclosure includes sides that isolate and ventilate the air inside to eliminate heat from the display. The enclosed display may serve as a module that can be displayed together as a larger immersive display.
2.1 Far-field Optics
The window of the enclosure may have a flat magnifying element (i.e., a positive diopter), which both magnifies and changes the apparent distance focused on the display. Its main purpose is to let the viewers' eyes accommodate at or near infinity even though they are relatively close to the display itself. As a magnifying element, its secondary purpose is to make the display look larger than it actually is. Additionally, the window of the enclosure may include some amount of framing around the front in such as way as to mask or partially mask the edges of the display, creating the illusion that the imagery displayed is even further away.
The amount of magnification and the distance of the magnifying element from the display are variable. The weaker the magnification and the shorter the distance to the display, the less the apparent focus will approach infinity but the wider the FOV in the viewing space in front of the enclosure. The stronger the magnification and the greater the distance to the display, the more the apparent focus may approach infinity, within limits, but the narrower the FOV in the viewing space in front of the enclosure.
A preferred embodiment may use a relatively medium to strong magnifying element placed a relatively short distance from the display, to maximize the effect while minimizing the amount of space used. For a typical flat panel display, e.g., 40 to 60 inch, the magnification may be 1.5x to 4x and the distance from the magnifying element to the display may be under 10 or 20 inches. It is not critical that true "infinity focus" is achieved as much as is suggested in order to create a rich immersive experience. Even a little bit helps, in fact, even with no magnification (1.0x), simply framing the front of the display enhances the illusion of distance behind.
The magnification element should be of sufficiently high quality to minimize additional artifacts to the display. Though it could in theory be a large "double-convex" glass element, it is more practical to use flat magnifying elements, the most common today being Fresnel lenses. A hologram of a magnifying element may then be used as a magnifying element, but such holographic elements are currently not practical on the scale required.
2.2 Climate-Controlled Enclosure
The enclosure may be made of climate-isolating material and encloses the display on the front, sides, and optionally on the back. The front consists mostly of the far-field optical element and optionally a small frame around the edges. The enclosure allows climate-controlled air to circulate through enclosed area.
A preferred embodiment may remove heat from the display by intaking air from below the enclosure and blowing it out to the rear at the top of the enclosure, using fans. The bottom of the enclosure and the top rear of the enclosure may be completely open. A more elaborate climate controller may be integral or a separated unit via known means such as vent, baffles, and ducts. It may be a simple fan or an actual air conditioner unit. The wider the volume of air circulation, the less noise.
The climate-controlled enclosure may also be used to affect the climate outside of the enclosure, in particular, of the viewers standing in front. For example, the temperature experienced by the viewers may be programmed to maintain reasonable comfort levels. Additionally, this temperature (and even humidity and scent through known means) may be synchronized with the imagery viewed. Output vents for may be above or below the display, or may be built into the vertical mullions.
2.3 Modular Design
The climate-controlled enclosure around a video display with far-field optics in front is designed to be modular and used in arrays, particularly in horizontal arrays approximating a cylinder for panoramic imagery. These modules may be only a few inches deeper than the display itself (to allow for magnification), a few inches higher than the display itself (for the ventilation intake and exhaust), and no wider than the optical element. Since the optical element magnifies, the display may be smaller than the optical element and the sides of the module may flange forward.
The climate control for each module may be independent or modules may be interconnected and share the same climate controller such as an external air conditioner, through known means of ducts and hoses. Additionally, the modules may be physically interconnected through known means of rapid attachment and detachment for fast and simple assembly and disassembly with proper registration among the displays.
Anecdotal evidence suggests that adding infinity focus and adding zero convergence stereoscopic 3D may both individually enhance the far-field viewing experience. Since stereoscopic 3D generally requires glasses (always true for more than one viewer), the preferred embodiment described above has the greatest enhancement at the smallest cost and effort by viewers. But a "deluxe" model, incorporating both infinity focus and stereoscopic 3D, is worth considering for an ultimate immersive viewing experience.
A preferred embodiment of such a system may use inexpensive "active" (LCD shutter) glasses and flat video displays capable of high frame rates, such as current 120 Hz "DLP" projection televisions. The far-field imagery, naturally 2D, may be digitally displaced horizontally for left and right eyes by the average human interocular distance (~2.5 inches), such that the viewers' eyes gaze in parallel with zero convergence. Assuming that all of the imagery is far-field, e.g., "landscape," no special 3D recording is required.
Such a system may also display mixed near-field and far-field imagery with little compromise. One minor modification may be to decrease the infinity focus of the magnifying element, e.g., from infinity to 8 or 10 feet, to help accommodate both near and far-field imagery. This display system may then be capable of showing stereoscopically recorded imagery as well as 2D recorded far-field landscapes.
(Interval Research Corporation, Banff Centre for the Arts, photo: Louie Psihoyos)
and Related Publications
Be Now Here Triptych http://www.naimark.net/projects/bnh3.html
Be Now Here http://www.naimark.net/projects/benowhere.html
Banff kinetoscope http://www.naimark.net/projects/banff.html
Karlsruhe Moviemap http://www.naimark.net/projects/karlsruhe.html
"Two Unusual Projection Spaces," Presence, Special Issue on Projection, MIT Press, 14.5,