Communications: electrical – Visual indication – Having light piping
Reexamination Certificate
1999-08-27
2001-02-27
Crosland, Donnie L. (Department: 2632)
Communications: electrical
Visual indication
Having light piping
C340S815470, C340S815550, C340S815760, C345S030000, C345S031000, C345S032000, C345S077000, C345S002200, C345S003100, C345S102000, C345S020000, C362S800000, C359S199200, C348S359000, C348S366000, C348S801000, C385S115000, C385S116000
Reexamination Certificate
active
06195016
ABSTRACT:
TECHNICAL FIELD
The present invention is directed to a fiber optic display system and more particularly to a fiber optic display system with enhanced light efficiency that is suitable for traffic signs or the like used outdoors.
BACKGROUND OF THE INVENTION
Large fiber optic displays are known in which the light receiving ends of the fiber optics are arranged in a bundle adjacent a small LCD display to pick up the image displayed thereon. The fiber optics couple the image to the light output ends of the fibers to display an enlarged image. The image output from the fiber optics is enlarged by spacing the light output ends of the fiber optics farther apart than the spacing between the light receiving ends of the fiber optics. Such fiber optic displays are difficult to use outdoors in bright light conditions because they are very light inefficient. For example, only approximately 2% of the backlight typically passes through a LCD panel. In order to control the viewing angle of the displayed images, the output ends of the fiber optics in some known displays have been cut at a very sharp angle. However, these types of fiber optic displays have problems with unwanted reflections of light back into the fibers. Another known fiber optic display employs a diffusion face plate spaced a distance from the fiber optic output ends. The diffusion plate spreads the light output from the fiber optics. However, because a diffusion plate does not aim or direct the light but randomly scatters light, it is not light efficient and further reduces the light output of the display. Moreover, the back light for the input image generator is typically a single element bulb so as to provide a uniformly illuminated input image. However, given the light inefficiencies of known fiber optic display systems, it is difficult to find a backlight with sufficient brightness to allow the fiber optic display to be used outdoors in ambient light conditions.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, prior fiber optic display systems have been overcome. The fiber optic display system of the present invention utilizes optical elements that increase the light efficiency and the light throughput of the fiber optic display so that it is suitable for use outdoors.
More particularly, the fiber optic display system of the present invention includes a plurality of fiber optics having first and second ends, the first ends being arranged in a bundle to receive an image. The fiber optics couple the received image to the second ends thereof for displaying the image where the spacing between the second ends of the fibers is greater than the spacing between the first ends of the fibers. The display system also includes a light source and an image generator disposed between the light source and the first ends of the fiber optics to generate an image that is focused on the first ends of the fiber optics. In accordance with the present invention, an array of lenses is positioned adjacent the second ends of the fiber optics for receiving light therefrom wherein the lenses aim the light output from the fiber optics to control the viewing angle of the image displayed. The lens array of the present invention substantially eliminates unwanted reflections back into the fiber optics and is extremely light efficient. Moreover, the position of the lens array with respect to the second or output ends of the fiber optics can be controlled to provide a desired viewing angle of the image displayed.
In one embodiment of the present invention, the lens array is formed as a panel of microlenses. In this embodiment, the array is movable with respect to the output ends of the fiber optics to vary the viewing angle of the image displayed. The position of the lens array is automatically controlled in accordance with data stored in a computer control unit of the display system. The display system includes a communication interface such as a modem or a wireless communication interface coupled to the system's computer control unit to allow the positioning of the lens array to be remotely controlled.
In a second embodiment of the present invention, a panel that supports the second or output ends of the fiber optics also supports an individual lens in association with each fiber optic. The positioning of the lens with respect to a fixed aperture associated with the fiber optic output end controls the viewing angle of the displayed image. Moreover, by utilizing a prismatic lens, the image may be directed to a particular location. When the fiber optic display is utilized to display traffic sign information, the prismatic lens can direct the image to a particular lane of traffic and to a particular location so that the image is seen by only the vehicle drivers to whom the information is directed.
To further increase the brightness of the fiber optic display, a light source is employed that is formed of a densely packed array of white light emitting diodes. In one embodiment, the light emitting diodes are mounted on one or more walls of a white interior illumination box. The light from the illumination box passes through a brightness enhancing film to a frosted plate so as to produce extremely bright but uniform white light illumination.
In accordance with another feature of the present invention, the fiber optic display system includes one or more “monitoring” fiber optics having an end supported in the output display panel for receiving ambient light. These “monitoring” fiber optics couple received ambient light to a photo detector that is in turn coupled to a controller. Based on the intensity of the ambient light as determined by the photo detector, the controller varies the brightness of the illumination source. Under bright ambient light conditions, such as daylight, the controller increases the brightness of the illumination source; whereas at night, the brightness of the illumination source can be decreased. Moreover, the detected light intensity can be monitored to determine if the face of the fiber optic display is dirty. This information can then be transmitted via the communication interface to a remote location so as to provide notice that the display needs cleaning.
In accordance with a further feature of the present invention, the input image generator includes a number of image bearing transparencies on a movable support. A motor is coupled to the transparency support and controlled to move the support to position a selected image bearing transparency between the light source and the first or input ends of the fiber optics so as to display the image depicted on the selected transparency. Each of the image bearing transparencies is accompanied by position indicia that is detected so as to provide position feedback and/or registration information for the controller. The controller is programmed to display selected images in a particular sequence and/or at particular times during the day. Moreover, the controller can receive information from a remote location to change the image displayed or the sequence of images displayed. The image generator of the present invention is extremely simple and robust but allows great flexibility so that different images can be depicted on the fiber optic display.
These and other advantages and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings.
REFERENCES:
patent: 3909109 (1975-09-01), Aurenz
patent: 4116739 (1978-09-01), Glenn
patent: 4417412 (1983-11-01), Sansom
patent: 4525711 (1985-06-01), Gery
patent: 4650280 (1987-03-01), Sedlmayr
patent: 4720165 (1988-01-01), Tokuda et al.
patent: 4738510 (1988-04-01), Sansom
patent: 4762392 (1988-08-01), Yamamoto et al.
patent: 4773730 (1988-09-01), Sedlmayr
patent: 4786139 (1988-11-01), Sedlmayr
patent: 4812012 (1989-03-01), Terada et al.
patent: 4815807 (1989-03-01), Kaneko et al.
patent: 4865417 (1989-09-01), Naohiro et al.
patent: 4867530 (1989-09-01), Sedlmayr
patent: 4917448 (1990-04-01), Oppenheimer
patent: 492904
Heacock Gregory L.
Shankle Matthew W.
Shankle Steven J.
Advance Display Technologies, Inc.
Crosland Donnie L.
McAndrews Held & Malloy Ltd.
LandOfFree
Fiber optic display system with enhanced light efficiency does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fiber optic display system with enhanced light efficiency, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fiber optic display system with enhanced light efficiency will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2612724