Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Progressive optics for side mirrors ends automobile blind spots without distorting view

29.01.2013
A new optical prescription for automobile side-view mirrors may eliminate the dreaded "blind spot" in traffic without distorting the perceived distance of cars approaching from behind. As described in a paper published today in the Optical Society's (OSA) journal Optics Letters, objects viewed in a mirror using the new design appear larger than in traditional side-view mirrors, so it's easier to judge their following distance and speed.

Today's motor vehicles in the United States use two different types of mirrors for the driver and passenger sides. The driver's side mirror is flat so that objects viewed in it are undistorted and not optically reduced in size, allowing the operator to accurately judge an approaching-from-behind vehicle's separation distance and speed. Unfortunately, the optics of a flat mirror also create a blind spot, an area of limited vision around a vehicle that often leads to collisions during merges, lane changes, or turns.


These images illustrate the performance between the aspheric and progressive mirror (top) and the flat and progressive mirror (bottom). In (a), the standard aspheric mirror is shown with a blue line to indicate the boundary between the two zones. This illustrates the distortion between the two zones. In (b), the progressive prescription developed by the researchers demonstrates the improved transition between zones, eliminating the blind spot while still giving an undistorted view of objects at a distance. (c) This is the standard flat side view mirror compared with (d) the wider field of view of the progressive mirror.

Credit: Credit: Optics Letters.

The passenger side mirror, on the other hand, possesses a spherical convex shape. While the small radius of curvature widens the field of view, it also causes any object seen in it to look smaller in size and farther away than it actually is. Because of this issue, passenger side mirrors on cars and trucks in the United States must be engraved with the safety warning, "Objects in mirror are closer than they appear." In the European Union, both driver and passenger side mirrors are aspheric (One that bulges more to one side than the other, creating two zones on the same mirror).

The inner zone—the section nearest the door—has a nearly perfect spherical shape, while the outer zone— the section farthest from the door—becomes less and less curved toward the edges. The outer zone of this aspheric design also produces a similar distance and size distortion seen in spherical convex designs.

In an attempt to remedy this problem, some automotive manufacturers have installed a separate, small wide-angle mirror in the upper corner of side mirrors. This is a slightly domed square that provides a wide-angle view similar to a camera's fisheye lens. However, drivers often find this system to be a distracting as well as expensive addition.

A simpler design for a mirror that would be free of blind spots, have a wide field of view, and produce images that are accurately scaled to the true size of an approaching object—and work for both sides of a vehicle—has been proposed by researchers Hocheol Lee and Dohyun Kim at Hanbat National University in Korea and Sung Yi at Portland State University in Oregon. Their solution was to turn to a progressive additive optics technology commonly used in "no-line multifocal" eyeglasses that simultaneously corrects myopia (nearsightedness) and presbyopia (reduced focusing ability).

"Like multifocal glasses that give the wearer a range of focusing abilities from near to far and everything in between, our progressive mirror consists of three resolution zones: one for distance vision, one for close-up viewing and a middle zone making the transition between the two," says Lee. "However, unlike glasses where the range of focus is vertically stacked [from distance viewing on top to close-up viewing on bottom], our mirror surface is horizontally progressive."

Lee says that a driver's side mirror manufactured with his team's new design would feature a curvature where the inner zone is for distance viewing and the outer zone is for near-field viewing to compensate for what otherwise would be blind spots. "The image of a vehicle approaching from behind would only be reduced in the progressive zone in the center," Lee says, "while the image sizes in the inner and outer zones are not changed."

The horizontal progressive mirror, Lee says, does have some problems with binocular disparity (the slight difference between the viewpoints of a person's two eyes) and astigmatism (blurring of a viewed image due to the difference between the focusing power in the horizontal and vertical directions). These minor errors are a positive trade off, the researchers feel, to gain a mirror with a greatly expanded field of view, more reliable depth perception, and no blind spot.

To prove the merits of their design, the researchers used a conventional glass molding process to manufacture a prototype horizontal progressive mirror. They were able to produce a mirror with more than double the field of view of a traditional flat mirror.

Other wide-angle designs have also been proposed, but the new design described today in the Optics Letters paper offers a particularly easy-to-manufacture approach to the problem of blind spots by seamlessly integrating just three zones.

The researchers claim that the manufacturing cost of their proposed mirror design would be cheaper than the mirror design with the added small wide-angle viewing section. Since mirror designs are stipulated by national automobile regulations, the new design would need to be approved for use in the United States before appearing on cars here.

Paper: "Horizontally progressive mirror for blind spot detection in automobiles," H. Lee, D. Kim, S. Yi, Optics Letters, Vol. 38, Issue 3, pp. 317 – 319 (2013).

EDITOR'S NOTE: An image and video clip of the new mirror are available to members of the media upon request. Contact Brielle Day.

About Optics Letters

Published by the Optical Society (OSA), Optics Letters offers rapid dissemination of new results in all areas of optics with short, original, peer-reviewed communications. Optics Letters covers the latest research in optical science, including optical measurements, optical components and devices, atmospheric optics, biomedical optics, Fourier optics, integrated optics, optical processing, optoelectronics, lasers, nonlinear optics, optical storage and holography, optical coherence, polarization, quantum electronics, ultrafast optical phenomena, photonic crystals, and fiber optics. This journal, edited by Alan E. Willner of the University of Southern California and published twice each month, is where readers look for the latest discoveries in optics. Visit www.OpticsInfoBase.org/OL.

About OSA

Uniting more than 180,000 professionals from 175 countries, the Optical Society (OSA) brings together the global optics community through its programs and initiatives. Since 1916 OSA has worked to advance the common interests of the field, providing educational resources to the scientists, engineers and business leaders who work in the field by promoting the science of light and the advanced technologies made possible by optics and photonics. OSA publications, events, technical groups and programs foster optics knowledge and scientific collaboration among all those with an interest in optics and photonics.

Brielle Day | EurekAlert!
Further information:
http://www.osa.org

More articles from Automotive Engineering:

nachricht Newly developed diamond transistor expected to reduce energy consumption in automobiles
20.02.2015 | Waseda University

nachricht First series production vehicle with software control
19.12.2014 | Siemens AG

All articles from Automotive Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neurochip für die Hirnforschung erfolgreich im Markt

Neues Mess- und Stimulationssystem nimmt die Kommunikation von Nervenzellen in Echtzeit auf und ermöglicht damit lang erhoffte Grundlagenforschung

Für die Enträtselung neurologischer und neurodegenerativer Erkrankungen wie Parkinson, Alzheimer, Depression oder verschiedene Erblindungsformen verspricht ein...

Im Focus: Klassisch oder nicht? Physik der Nanoplasmen

Die Wechselwirkung von intensiven Laserpulsen mit Partikeln auf einer Nanometer-Skala resultiert in der Erzeugung eines expandierenden Nanoplasmas.

In der Vergangenheit wurde die Dynamik eines Nanoplasmas typischerweise durch klassische Phänomene wie die thermische Emission von Elektronen beschrieben. Im...

Im Focus: Klimawandel: Nur auf der Erde, nicht auf dem Mars

Löcher in der Polkappe sind natürlichen Ursprungs

Eine Klimaerwärmung findet auf dem Mars trotz schmelzender Polkappen nicht statt. Zu diesem Ergebnis ist eine Studie der University of Arizona http://www.arizona.edu...

Im Focus: Experiment Provides the Best Look Yet at 'Warm Dense Matter' at Cores of Giant Planets

In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...

Im Focus: Energieautark und kabellos: Neuartiges Messsystem schützt Schiffe vor Ausfällen

Wie der Schiffsverkehr zuverlässiger werden kann, während gleichzeitig der Instandhaltungsaufwand sinkt, zeigt das IPH bei der Hannover Messe 2015. Gemeinsam mit Projektpartnern hat das hannoversche Forschungsinstitut ein Sensorsystem entwickelt, das den Zustand von Schiffsgetrieben permanent überwacht und so Ausfällen vorbeugt. Das Besondere: Das Überwachungssystem funktioniert drahtlos und energieautark. Der benötigte Strom wird dort erzeugt, wo er gebraucht wird – direkt am Sensor.

Autos müssen regelmäßig zum TÜV, Schiffe müssen zur Inspektion – denn wenn mitten im Verkehr der Antrieb ausfällt, ist das nicht nur ärgerlich, sondern auch...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Technologietag bei der SCHOTT AG - Neue Strukturierungstechnologien für Dünngläser

26.03.2015 | Veranstaltungen

7th Mildred Scheel Cancer Conference

26.03.2015 | Veranstaltungen

Corporate Venturing als Quelle unternehmerischer Innovationen

26.03.2015 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Künstliche Muskeln: Gelenkiger Spinnen-Greifer für Industrieroboter passt sich dem Werkstück an

26.03.2015 | HANNOVER MESSE

Technologietag bei der SCHOTT AG - Neue Strukturierungstechnologien für Dünngläser

26.03.2015 | Veranstaltungsnachrichten

Bislang bester Blick auf Staubwolke, die am Schwarzen Loch im Zentrum der Milchstraße vorbeizog

26.03.2015 | Physik Astronomie