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Claims  |
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I claim:
1. A system permitting a commercial advertiser with retail stores to place
video or still-image advertisements at selected times and locations on a
network of multiple electronic roadside displays, and to tie the roadside
advertisements into point of purchase displays at the advertiser's retail
stores, said system comprising:
a network including a plurality of roadside electronic displays;
means permitting a commercial advertiser with retail stores to place video
or still-image advertisements at selected times on selected ones of the
network's roadside electronic displays; and
point of purchase displays at selected ones of the commercial advertiser's
retail stores displaying content that ties into the content of the video
or still-image advertisements run on the roadside electronic displays.
2. The system of claim 1 wherein said means permitting a commercial
advertiser to place advertisements includes a central processing station
that permits a commercial advertiser to transmit its advertising content
to the station from which it is routed for display at the
customer-selected roadside electronic displays.
3. The system of claim 2 wherein the point of purchase displays at selected
ones of the commercial advertiser's retail stores are electronic point of
purchase displays, said network of electronic displays includes the point
of purchase displays and the content of the point of purchase displays is
transmitted by the advertiser through said central processing station.
4. The system of claim 1 wherein the point of purchase displays at selected
ones of the commercial advertiser's retail stores are electronic point of
purchase displays.
5. The system of claim 4 wherein said electronic point of purchase displays
comprise electronic ink displays.
6. The system of claim 4 wherein the electronic point of purchase displays
are part of a network of point of purchase displays in multiple stores,
said network being independent of said roadside electronic display network
and controlled by the commercial advertiser.
7. The system of claim 1 wherein the roadside advertisements display
information concerning special value or promotional items for sale at the
advertiser's retail stores and the point of purchase displays repeat the
special value or promotional sale information.
8. The system of claim 1 wherein the roadside advertisements include
information concerning the locations of area stores of the commercial
advertiser.
9. A method permitting a commercial advertiser with retail stores to place
video or still-image advertisements at selected times and locations on a
network of multiple electronic roadside displays, and to tie the roadside
advertisements into point of purchase displays at the advertiser's retail
stores, said method comprising:
permitting a commercial advertiser with retail stores to place video or
still-image advertisements at selected times on selected roadside
electronic displays; and
providing point of purchase displays at selected ones of the commercial
advertiser's retail stores displaying content that ties into the content
of the video or still-image advertisements run on the roadside electronic
displays.
10. A system for presenting video or still-image content at selected times
and locations on a networked connection of multiple electronic displays,
said system comprising:
a network interconnecting a plurality of electronic displays provided at
various locations, and a plurality of point of purchase displays provided
at places of business;
means enabling said business to schedule presentation of video or
still-image content at selected time slots on selected electronic displays
of said network, said means receiving said video or still-image content
from a content provider; and
transmission means in communication with said receiving means for
communicating scheduled content to server devices, a server device
associated with a selected electronic display of said network for
initiating display of said video or still-image content at a selected time
on a selected display of said network, a server device additionally
coordinating display of content associated with the video or still-image
content presented on the selected electronic displays at point of purchase
displays located at a selected businesses.
11. The system of claim 10, further including a central processing server
for scheduling and for receiving said video or still-image content from
said content provider, said central processing server initiating
communication of said video or still-image content at the selected
electronic displays at the selected times.
12. The system of claim 11, wherein the point of purchase displays at
selected ones of the places of business are electronic point of purchase
displays, said network of electronic displays including the point of
purchase displays and the content of the point of purchase displays is
transmitted by the content provider through said central processing
server.
13. The system of claim 10, wherein the point of purchase displays at
selected ones of the places of business are electronic point of purchase
displays.
14. The system of claim 13, wherein said electronic point of purchase
displays comprise electronic ink displays.
15. The system of claim 13, wherein said network comprises a first network
comprising said plurality of electronic displays provided at various
locations, and a second network comprising a plurality of point of
purchase displays located at one or more places of business, said first
and second networks capable of being controlled by an agent of said
business.
16. The system of claim 10, wherein the content for display includes
advertisements directed to special value or promotional items for sale at
the places of business, said point of purchase displays receiving a
separate transmission for repeating the special value or promotional sale
information.
17. The system of claim 16, wherein the displayed advertisements include
information content providing locations of the places of business.
18. The system of claim 11, wherein a content provider includes an agent of
said business, said central processing server comprises means for enabling
said agent to view and schedule of times and electronic display locations
that are available for placement said content, and additionally enabling
said agent to purchase one or more available time slots at selected
electronic display locations for presenting said content.
19. The system of claim 18, further comprising means in connection with
said central processing server for enabling a review of received
transmitted video or still image content prior to transmission to the
selected electronic display, said content being transmitted to said
selected electronic display upon reviewer approval of said content.
20. The system of claim 11, wherein said content includes one or more of
public service announcements, news, or sporting events.
21. The system of claim 18, further including an interface server device
for providing Internet access to said central processing server and
enabling remote viewing, scheduling and purchasing from remote locations.
22. The system of claim 21, further including a security device for
enabling said agent to obtain and enter security code and billing code
information to identify said agent prior to accessing said system.
23. The system of claim 22, further including dedicated high-speed
connection to said security device for enabling high-usage agents to
access the system.
24. The system of claim 11, wherein said content is transmitted to said
central processing server according to a mechanism selected from the group
comprising: on-line through the Internet, a direct phone line, and, a high
speed information transfer line.
25. The system of claim 11, wherein said still image or video advertising
content is formatted according to one format selected from the group
comprising: NTSC, PAL, SECAM, YUV, YC, and VGA.
26. The system of claim 19, further including one or more high speed server
devices associated with each electronic display providing functionality
for driving said electronic displays, said content being transmitted to a
server device associated with a selected display upon approval of said
content to be displayed.
27. The system of claim 26, wherein said transmission means is selected
from the group comprising: high speed cable, a satellite link, a dedicated
phone connection, a high-speed communications line, a cellular or PCS data
transmission device, the Internet, a radio or radio pulse transmission
device, a high speed optical fiber, and physical delivery of a medium
storing said content.
28. The system of claim 27, wherein said medium storing said content
includes one of CD ROM, zip drive, DVD ROM or DVD RAM.
29. The system of claim 27, further including a video converter/scaler
mechanism associated with said high speed server devices for each display,
said video converter/scaler mechanism enabling any required reformatting
of said content according to said transmission means implemented.
30. The system of claim 26, further including:
means linked to each electronic display for verifying that advertisements
for the intended display are displayed at the intended time at the
intended display and generating verification information pertaining
thereto; and,
means for receiving and storing said verification information generated by
each said verification means.
31. The system of claim 30, wherein said verifying means includes a digital
camera for recording the content appearing at its respective display.
32. The system of claim 30, further including a traffic count recorder
means linked to each electronic display for counting amount of traffic
passing an electronic display during a particular time slot and generating
traffic count information for receipt and storage by said archival means.
33. The system of claim 32, further including a means for receiving said
stored verification and traffic count information, analyzing said
information and generating demographic information for reports to be sent
to said business after their content is displayed.
34. The system of claim 33, wherein said demographic information for
reports comprises information including: a time of the advertisement, the
content of the advertisement, the traffic count, and residence/median
income information about those who may have viewed the advertisement.
35. The system of claim 30, further including means for generating bills
capable of being transmitted by phone lines to said businesses.
36. The system of claim 18, further including auction sub-system for
enabling previously purchased time slots and all unsold time slots to be
auctioned through a bid process.
37. The system of claim 36, wherein said auction sub-system enables the
purchase of time slots for a set price, and all time not purchased at the
set price becomes available through said auction sub-system at a fixed
time before the run time.
38. The system of claim 18, further including means for preselecting time
slots for display of the agent's content at a "best available rate"
pricing for those high volume agents having establish a monthly budget to
purchase a portion of the available time slots.
39. The system of claim 38, further including means for optimizing
pre-selection of time slots for display of the agent's content in
accordance with needs of said agent and said system.
40. A method for presenting video or still-image content at selected times
and locations on a networked connection of multiple electronic displays,
said method comprising:
a) providing a network including plurality of electronic displays provided
at various locations, and a plurality of point of purchase displays
located at one or more places of business;
b) enabling an agent of said business to schedule video or still-image
content at selected times on selected electronic displays of said network
and receiving said video or still-image content from a content provider;
c) providing a plurality of server devices, each server device associated
with a corresponding electronic display;
d) communicating received video or still-image content to the associated
server devices of corresponding selected electronic displays of said
network, said associated server devices initiating display of said video
or still-image content at selected times on selected electronic displays
of said network; and,
e) coordinating display of content associated with the video or still-image
content presented on the selected displays at point of purchase displays
at selected ones of the places of business.
41. The method of claim 40, wherein prior to placement of video or
still-image advertisements at selected times on selected electronic
displays, the steps of:
enabling an agent to view a schedule of times and electronic display
locations that are available for placement of advertising content; and,
enabling an agent to purchase one or more available time slots at selected
electronic display locations for placement of their content.
42. The method of claim 41, wherein prior to placement of video or
still-image advertisements at selected times on selected electronic
displays, the steps of:
providing an appropriateness review of transmitted video or still image
content; and
transmitting said content to said selected electronic display upon approval
of said content.
43. The method of claim 41, further comprising the step of providing said
agent with Internet access for enabling remote viewing, scheduling and
purchasing from remote locations.
44. The method of claim 42, wherein prior to enabling agent access to said
schedule of times and available electronic display locations, the step of
providing security code and billing code information for identifying said
agent and authorizing agent access to said system.
45. The method of claim 44, further including providing dedicated
high-speed connection to a security device for enabling high-usage agents
to access the schedule of times and available electronic display
locations.
46. The method of claim 44, further including the step of transmitting said
content to a central processing server for receipt thereof according to a
mechanism selected from the group comprising: on-line through the
Internet, a direct phone line, and, a high speed information transfer
line.
47. The method of claim 44, further comprising the step of formatting said
still image or video advertising content according to a format selected
from the group comprising: NTSC, PAL, SECAM, YUV, YC, and VGA.
48. The method of claim 42, wherein an associated server device includes
one or more high speed server devices for driving said electronic
displays, said content being transmitted to a server device associated
with a selected display upon approval of said content to be displayed.
49. The method of claim 46, further including the step of transmitting said
content to a server device associated with a selected display by a
transmission means selected from the group comprising: high speed cable, a
satellite link, a dedicated phone connection, a high-speed communications
line, a cellular or PCS data transmission device, the Internet, a radio or
radio pulse transmission device, a high speed optical fiber, and physical
delivery of a medium storing said content.
50. The method of claim 49, further including the step of enabling any
required reformatting of said content according to said transmission means
implemented.
51. The method of claim 49, further including the steps of: verifying that
advertisements for the intended display are displayed at the intended time
at the intended display and generating verification information pertaining
thereto; and,
receiving and storing said verification information generated.
52. The method of claim 51, wherein said verifying step includes
implementing a digital camera for recording the content appearing at its
respective display.
53. The method of claim 51, further including the steps of:
counting amount of traffic passing an electronic display during a
particular time slot; and
generating traffic count information for receipt and storage by an archival
means.
54. The method of claim 52, further including the steps of:
receiving said stored verification and traffic count information;
analyzing said information; and,
generating demographic information for reports to be sent to agents after
their advertisements are displayed.
55. The method of claim 54, wherein said demographic information for
reports comprises information including: a time of the advertisement, the
content of the advertisement, the traffic count, and residence/median
income information about those who may have viewed the advertisement.
56. The method of claim 51, further including the steps of:
generating bills associated with purchased time slots; and,
transmitting said bills via phone lines to an agent representing said
business establishment.
57. The method of claim 51, further including the step of auctioning
previously purchased time slots and all unsold time slots through a bid
process.
58. The system of claim 57, wherein said auctioning step includes: enabling
the purchase of time slots for a set price, and enabling all time slots
not purchased at the set price to become available through said auction
sub-system at a fixed time before the run time.
59. The method of claim 57, further including the step of: preselecting
time slots for display of the agent's content at a "best available rate"
pricing for those high volume agents having establish a monthly budget to
purchase a portion of the available time slots. |
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Claims |
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Description |
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FIELD OF THE INVENTION
The invention relates to the display of video or still image content on
electronic displays. More particularly, the invention relates to a network
of thousands of large, high resolution roadside electronic billboard
displays, and an associated system that permits retail stores to place
advertisements on the displays while tying the advertisement content into
the content of point of purchase displays at their stores.
BACKGROUND OF THE INVENTION
Consumer product advertising takes many forms, such as television
commercials, newspaper and magazine advertisements, mailings,
point-of-sale displays, outdoor billboards, etc.
Using current advertising media, advertisers engage in a constant struggle
to efficiently use their budgets to most effectively reach their
geographic and demographic targets.
Focusing on the outdoor advertising component of advertising by consumer
product companies, it is well known that outdoor billboards have
traditionally taken the form of single-message displays formed of printed
sheets or painted surfaces containing the advertising content adhered to a
flat backing. This time-honored outdoor advertising technique has remained
essentially unchanged throughout the twentieth century. The high cost of
printing, transporting and mounting a message on a conventional billboard
has dictated that the same message remain in place for a considerable
period of time. Thus, a conventional billboard cannot be readily changed
to reflect current events within the geographic area of the billboard.
Additionally, the content on a conventional billboard tends to become
essentially "invisible" as a part of the landscape after its content has
been in place for a relatively short period of time, especially to
commuters and others who regularly pass the billboard. Beyond the above
problems with cost, single-message content, lack of content changeover
capability, and the like, conventional outdoor billboards have come under
increasing criticism because in their large numbers, and often tattered
condition, they clutter highways with a distasteful form of visual
"pollution". A reduction in the number of billboards and improvement of
the appearance and profitability of those that remain, if accomplished
while increasing the overall advertising impact afforded by outdoor
advertising, would please virtually everyone.
The use of electronic billboards has been suggested, for example, in U.S.
Pat. No. 5,612,741. However, there is no electronic billboard network in
operation whereby commercial advertisers may directly place ads onto
selected billboards at selected times through direct access to a master
network. Such a network, properly designed and operated, promises to
overcome the numerous disadvantages currently associated with the outdoor
advertising industry, while also meeting the above needs of consumer
products advertisers.
Turning now to point of purchase advertising, it is well known that various
retail stores such as department stores, fast food restaurants, building
supply stores, and the like, utilize point of purchase displays to inform
customers of product specifications and pricing and to promote periodic
special value or "sale" items. These point of purchase displays usually
take the form of inexpensive paper product displays that are mounted
adjacent to products being promoted, or displays located in a general
store location (such as the entrance) to communicate more general
information to consumers. Other forms of point of purchase displays may be
used, such as electronic displays, for example, displays utilizing
"electronic ink" technology. Current product advertising techniques do not
effectively tie point of purchase displays to other forms of advertising,
particularly to outdoor advertising.
SUMMARY OF THE INVENTION
The present invention, in one broad aspect, is a system that permits a
commercial advertiser with retail store(s) to place video or still-image
advertisements at selected times on a network of multiple roadside
electronic displays, and to tie the roadside advertisements into point of
purchase displays at the advertiser's retail stores.
Commercial advertisers, such as retail store chains and the advertising
agents that represent them, directly access a network of multiple, large,
high resolution electronic displays located in high traffic areas and
directly send their own advertisements electronically to the network to be
displayed at locations and times selected by the advertisers. In preferred
embodiments, this implementation of the invention includes a central
information processing center that permits customers to review a schedule
of times and electronic display locations that are available for placement
of advertisements, and also permits customers to purchase available times
at selected electronic display locations for placement of their
advertising content. The customer then transmits his video or still image
advertising content to the processing center where the content is reviewed
for appropriateness and then transmitted to the customer-selected
electronic display(s). The electronic displays preferably are large (e.g.,
23.times.331/2 ft.) flat LED displays that are driven by their own video
or image servers. In conjunction with the placement of advertisements on
the roadside electronic displays (billboards), the advertiser also
provides point of purchase displays at each retail store with content that
ties into the roadside advertisements. For example, both the roadside
advertisement and the point of purchase displays may focus on specific
special value or "sale" items, with the point of purchase displays
repeating the sale information and directing customers to the store
location(s) where the sale items may be found. The point of purchase
displays may be electronic displays, most preferably displays employing
electronic ink technology. Electronic point of purchase displays may be
incorporated into the same network as the roadside electronic displays or
they may be operated by a private network controlled by the commercial
advertiser who owns the retail stores.
BRIEF DESCRIPTION OF THE DRAWINGS
Some of the features of the invention having been stated, other features
will appear as the description proceeds, when taken in connection with the
accompanying drawings, in which
FIG. 1 is a block diagram showing the principal components of a system
constructed in accordance with the present invention for advertising
purposes.
FIG. 2 is a view of one of the electronic displays of the network of FIG.
1.
FIG. 3A is a view of a roadside electronic display of the network that is
displaying special value items that are being offered at a retailer's area
stores, as well as a map and street address information useful to locate
the stores.
FIG. 3B shows the entrance to one of the area stores of the retailer who
placed the roadside advertisement shown in FIG. 3A, and also shows a point
of purchase display next to the entrance. The content of the point of
purchase display ties into the content of the roadside advertisement.
DETAILED DESCRIPTION OF THE INVENTION
While the present invention will be described more fully hereinafter with
reference to the accompanying drawings, in which aspects of the preferred
manner of practicing the present invention are shown, it is to be
understood at the outset of the description which follows that persons of
skill in the appropriate arts may modify the invention herein described
while still achieving the favorable results of this invention.
Accordingly, the description which follows is to be understood as being a
broad, teaching disclosure directed to persons of skill in the appropriate
arts, and not as limiting upon the present invention.
Referring to the drawings, and particularly to FIG. 1, there is shown a
block diagram of a system 20 for direct placement of commercial
advertisements, public service announcements and other content on
electronic displays. System 20 includes a network comprising a plurality
of electronic displays 30 that are located in high traffic areas in
various geographic locations. The displays may be located in areas of high
vehicular traffic, and also at indoor and outdoor locations of high
pedestrian traffic, as well as in movie theaters, restaurants, sports
arenas, casinos or other suitable locations. Thousands of displays, up to
10,000 or more displays worldwide, may be networked according to the
present invention. In preferred embodiments, each display is a large (for
example, 23 feet by 331/2 feet), high resolution, full color display that
provides brilliant light emission from a flat panel screen.
A customer of system 20, for example an in-house or agency representative
of a consumer products company, may access a central information
processing station of the system via the Internet through a customer
Interface Web Server 40. The customer interface web server has a commerce
engine and permits the customer to obtain and enter security code and
billing code information into a Network Security Router/Access module 50.
Alternatively, high usage customers of the system may utilize a customer
interface comprising a high speed dedicated connection to module 50.
Following access, the customer reviews options concerning his order by
reviewing available advertising time/locations through a Review Schedule
and Purchase Time module 60 that permits the customer to see what time is
available on any display throughout the world and thereafter schedule and
purchase the desired advertising time slot. Next, the customer transmits
the advertising content on-line through the Internet, a direct phone line
or a high speed connection (for example, ISDN, or other suitable high
speed information transfer line) for receipt by the system's Video & Still
Image Review and Input module 70. In parallel, the system operator may
provide public service announcements and other content to module 70. All
content, whether still image or video, is formatted in NTSC, PAL, SECAM,
YUV, YC, VGA or other suitable formats. In a preferred embodiment, the
format is VGA, while all other formats, including but not limited to NTSC,
PAL and SECAM, can be run through the video converter 110.
The video & still image review and input module 70 permits a system
security employee to conduct a content review to assure that all content
meets the security and appropriateness standards established by the
system, prior to the content being read to the server 100 associated with
each display 30 where the content being transmitted to the server 100 will
be displayed. Preferably, the servers are located at their respective
displays and each has a backup. An example of a suitable server is the IBM
RISC 6000 server.
The means for transmitting content information to the display locations may
take a number of forms, with it being understood that any form, or
combination thereof, may be utilized at various locations within the
network. As shown in FIG. 1, the means include:
a. High speed cable
b. Satellite
c. Dedicated phone
d. High speed line (e.g., ISDN, ADSL)
e. Cellular, PCS or other data transmission at available frequencies
f. Internet
g. Radio/radio pulse transmission
h. High speed optical fiber
i. Physical delivery of digitally stored information medium.
A video converter/scaler function and a video controller function provided
by module 110 may be utilized in connection with those servers 100 and
associated displays 30 that require them, according to data transmission
and required reformatting practices well known in the art.
Verification that advertisements do, in fact, run at the intended time at
the intended displays may be provided by an information storage module
(not shown) linked to each display. Another form of verification may be
achieved by a Digital Camera and Traffic Count Recorder 120 that
continuously records the content appearing at its respective display 30
and digitally transmits video verification information to a Verification
Archives module 150. Recorder 120 also provides traffic count information
(for example, 225 vehicles passed the display while an advertisement ran)
to verification archives module 150.
Information from verification archives module 150 is utilized by a
demographic analysis module 160 and a market analysis module 170 to
generate information for reports to be sent to customers after their
advertisements run. To this end, analysis data from modules 160 and 170 is
transmitted to a Billing and Report Generation module 190 where reports
are assembled showing, for example, the time of the advertisement, the
content of the advertisement, the traffic count and residence/median
income information about those who saw the advertisement. A
representative, simplified report for an advertisement running on a single
display is as follows:
Customer: ABC Cola Co.
Ad Content: Ocean Scene with graphics
(content code 1111)
Location: Atlanta, Georgia, Interstate
75N, milepost 125 (site code
XXXX)
Time: 7:30 AM, June 30, 2000
Vehicle Count: 225
Viewer Count: 340
Viewer Demographics: 50% Resident Cobb
County, GA
Median household
income: $60,000/yr.
30% Resident DeKalb
County, GA
Median household
income: $52,000/yr.
20% Median household
income $55,000/yr.
Advertising Cost: $X
For an advertisement that may have run at multiple displays, for example
100 displays, a representative report may appear as follows:
Customer: ABC Cola Co.
Ad Content: Mountain Scene with
graphics (content code 2222)
Locations: 100 sites (site codes
YYY....ZZZ)
Time: 8:30 AM, July 10, 2000
Total Vehicle Count: 21,500
Total Viewer Count: 37,200
Viewer Demographics: Median household
income, $49,500
Advertising Cost: $Y
Module 190 also produces bills that may be transmitted by phone lines for a
debit payment such as a direct bank draft, or other suitable payment mode.
Referring to FIG. 2, there is shown a pictorial view of one preferred form
for the electronic displays 30. In this embodiment, display 30 takes the
form of a 23 feet by 331/2 feet seamless flat screen display including
multiple flat panel display modules. The panels utilize advanced
semiconductor technology to provide high resolution, full color images
utilizing light emitting diodes (LED's) with very high optical power
(1.5-10 milliwatts or greater) that are aligned in an integrated array
with each pixel having a red, green and blue LED. It will be appreciated
that multiple LED's of a given color may be used at pixels to produce the
desired light output; for example, three 1.5 milliwatt blue LED's may be
used to produce a 4.5 milliwatt blue light output. Each red, green and
blue emitter is accessed with 24 bit resolution, providing 16.7 million
colors for every pixel. An overall display of 23 feet by 331/2 feet, so
constructed, has a high spatial resolution defined by approximately
172,000 pixels at an optical power that is easily viewable in bright
sunlight. Suitable display modules for displays 30 are manufactured by
Lighthouse Technologies of Hong Kong, China, under Model No. LV50 that
utilize, for blue and green, InGaN LED's fabricated on single crystalline
Al.sub.2 O.sub.3 (sapphire) substrates with a suitable buffer layer such
as AlN and, for red, superbright AlInGaP LED's fabricated on a suitable
substrate such as GaP. These panels have a useful life in excess of 50,000
hours, for example, an expected life under the usage contemplated for
network 20 of 150,000 hours and more. In preferred embodiments, the panels
are cooled from the back of the displays, preferably via a
refrigerant-based air conditioning system (not shown) such as a forced air
system or a thermal convection or conduction system. Non refrigerant-based
options may be used in locations where they produce satisfactory cooling.
The displays preferably have a very wide viewing angle, for example,
160.degree..
While the Lighthouse Technologies displays utilize the InGaN on sapphire
and AlInGaP on GaP LED's described above (and in certain cases InGaN on
SiC), other materials may be used for the LED's as follows:
1. (Blue/green) InGaN on SiC, preferably with a suitable buffer layer such
as AlN
2. (Blue/green) InGaN on GaN
3. (Blue/green) InGaN on AlN, preferably with a suitable buffer layer such
as AlN.
4. (Blue/green) A1N or AlN-containing compound on AlN, sapphire or SiC.
It will be appreciated that the InGaN on sapphire and the other solid state
LED's described above have substrates with high optical transmissivity and
produce very high optical power.
This is important for a number of reasons, including giving the electronic
display designers the ability to create very wide viewing angles up to
approximately 160.degree., and the resultant increase in visibility of the
displays to viewers in oncoming traffic.
In addition to the particular solid state LED's mentioned above, the
discrete sources of blue, green and red light at each pixel may take other
forms such as composite devices including an ultraviolet LED that is
utilized to excite a phosphor that, in turn, produces light of a selected
spectrum. The ultraviolet LED may be formed from a GaN or GaN-containing
compound on sapphire with or without suitable buffer layer, or a GaN or
GaN-containing compound on SiC, preferably with a suitable buffer layer,
or an AlN or AlN-containing compound on AlN, sapphire, SiC or GaN, with or
without a suitable buffer layer. In one embodiment, ultraviolet LED's are
incorporated into three different composite devices, each with a different
phosphor for producing blue, green and red, respectively. In another
embodiment, a phosphor is selected to produce white light and a desired
color is produced by passing the white light through a band pass filter.
According to this white light embodiment, filters of blue, green and red
may be used to create discrete composite devices that produce blue, green
and red light at each pixel. The use of white light with appropriate band
pass filters has the advantage of producing a colored light with an
excellent wave length distribution that will not change appreciably over
time, a desirable property for color balancing. On the other hand, the use
of three different phosphors to directly produce blue, green and red
without a filter has the advantage of higher efficiency because light is
not filtered out. Both approaches have the advantage of excellent
persistence which, as known in the art, is a desirable feature that is
especially important in video applications, particularly digital movie
theater applications that are discussed in detail below.
It will be appreciated that energy sources other than ultraviolet LED's may
be used to excite the phosphors of the composite devices discussed
immediately above.
In the case of low ambient light applications, such as digital movie
theaters, lower power LED's may be used. Furthermore, higher power LED's
may be used to provide a light source for an LCD shutter-type screen as
described in U.S. Pat. No. 5,724,062, incorporated herein by reference.
The provision of one or more high resolution, highly aligned digital
cameras at each display site, for example the camera or cameras utilized
in digital camera and traffic counter 120, or other specifically dedicated
cameras, provides a means permitting in situ diagnostics and calibration
of the displays. As known in the art, certain digital cameras have a
resolution of over 7,000,000 pixels--as compared to approximately 172,000
pixels on the above-described 23.times.331/2 ft. display. Thus, by
directing a digital camera at a display, or directing multiple digital
cameras at different discrete portions of a display, a correspondence may
be attained where a portion of each digital camera's image corresponds to
a single pixel in the display. Suitable means for aligning the digital
camera with the display is used, for example, optical means such as laser
alignment marks. At selected times set aside for diagnostics and
calibration, such as a five minute period each night, the entire display
may be run red, then green, then blue, followed by white, all at multiple
power levels. In order to reduce interference, the LED's may be switched
on individually for a short period, for example one millisecond each. In
the most basic diagnostic operation carried out when the display is run
red/green/blue, the camera(s), mounted at a selected distance from the
display such as sixty feet away, are capable of detecting nonfunctioning
or excessively degraded LED's for replacement.
Beyond replacing defective LED's, each night the system may automatically
re-calibrate all LED's in the display. To this end, the display is run
red/green/blue at several iterative power levels (e.g.,
20%/40%/60%/80%/100%) and the optical power output of each LED is sensed
for each power level, with the goal being to calibrate the system so that
each red, green or blue LED has the same optical power output at each
power level as do the other LED's of the same color. Calibration
preferably is achieved by diode recalibration scaler software (e.g., look
up table) that may be associated with a scaler (not shown) that acts
independently in conjunction with the video converter/scaler at 110 (FIG.
1). The diode recalibration scaler receives information from the
diagnostic equipment indicating the optical power output of each LED at
the various power levels and, through an associated automatic calibration
LED look-up table, accounts for daily variance in LED output (degradation
or increase) by adjusting the power curve by which the LED will be driven
the next day. This periodic (e.g. daily) in situ recalibration has the
benefit of greatly reducing on site maintenance since LED's that have
degraded can be run harder to compensate for the degradation, eliminating
the need for frequent replacement.
As an alternative to using digital cameras for the diagnostic and
calibration function, in other embodiments miniature photodetector chips,
with or without band pass filters, may be located in close proximity to
each LED in the display for measuring LED light output during
diagnostic/calibration operations.
As another alternative, a programmable chip may be located at each pixel so
that each individual chip may be reprogrammed as necessary during each
calibration sequence to raise or lower the effective light output of the
LED's contained in the pixel.
As an alternative to performing daily in situ calibration by looking at
every pixel in sequence and adjusting the scaling value for each pixel, a
statistical modeling approach may be utilized. According to this approach,
selected LED's or groups of LED's may be run in iterative power cycles in
order to optimize the overall screen color through statistical analysis to
provide a new scaling value for each LED or group of LED's.
When the diagnostic operation operates with an all white display, the three
LED's at each pixel may be evaluated individually and collectively to
assure that the pixel is contributing the proper spectrum and amount of
white light. Through a diagnostic/calibration software package that
interrelates output and peak wave length response for each red/green/blue
LED at a pixel to the desired white light response, an iterative
calibration may be undertaken at each pixel to adjust the values contained
in the diode recalibration scaler software or to reprogram programmable
logic chips that determine the drive current for each LED located in a
specific pixel.
It will be appreciated that split screen images may be displayed at the
displays 30. In the simplest application, a still image advertisement may
be one half corporate logo and one half scenery. Beyond this simple
application, split screen capability may be used to present a portion of
the image as a corporate logo, or the like, and the remainder either real
time (or near real time) video or still frame. For example, a previously
qualified customer with acceptable internal content review procedures may
have direct access to a display or displays for the purpose of displaying
a real time (or near real time) sports event, news event, or the like, in
conjunction with the customer's corporate logo. This display may be
achieved by utilizing high speed servers 100 or by bypassing the servers
altogether. High speed still image or video transfer may be facilitated by
compression techniques such as JPEG and MPEG II, known in the art.
While advertising scheduling and purchasing may take place as described
above where customers directly purchase time from available slots
according to a fixed fee schedule, it will be appreciated that alternative
modes may be used. For example, an auction system such as introduced by
eBay Corporation may be used where all previously purchased slots and all
unsold slots are auctioned through a bid process (a "total" auction).
Additionally, a limited auction may be utilized where time may be
purchased and booked for a set price, but all time not purchased at the
set price becomes available through auction at a fixed time before the run
time, for example, one month before run time. As another alternative for a
portion of the available time slots, a high usage customer may establish a
monthly advertising budget with the system operator that authorizes the
operator to select the time slots for display of the customer's
advertisements at "best available rate" pricing, taking advantage of last
minute availability of time slots and other time | | |
