U.S. patent application number 13/076857 was filed with the patent office on 2011-07-21 for pixel interleaving configurations for use in high definition electronic sign displays.
This patent application is currently assigned to DAKTRONICS, INC.. Invention is credited to ERIC S. BRAVEK, CHAD N. GLOEGE, RYAN M. HANSEN, BRENT A. JOFFER, GLENN P. LUKE, MATT R. MUELLER, SHANNON LEE MUTSCHELKNAUS, NATHAN L. NEARMAN, JOSEPH G. SCHULTE, BRETT D. WENDLER.
Application Number | 20110175888 13/076857 |
Document ID | / |
Family ID | 39762260 |
Filed Date | 2011-07-21 |
United States Patent
Application |
20110175888 |
Kind Code |
A1 |
JOFFER; BRENT A. ; et
al. |
July 21, 2011 |
PIXEL INTERLEAVING CONFIGURATIONS FOR USE IN HIGH DEFINITION
ELECTRONIC SIGN DISPLAYS
Abstract
Pixel interleaving configurations for use in high definition
electronic sign displays where each and every scan line includes
full red, green, and blue color representation to provide for high
resolution electronic video sign displays.
Inventors: |
JOFFER; BRENT A.;
(BROOKINGS, SD) ; WENDLER; BRETT D.; (WATERTOWN,
SD) ; LUKE; GLENN P.; (BROOKINGS, SD) ;
NEARMAN; NATHAN L.; (BROOKINGS, SD) ; GLOEGE; CHAD
N.; (BROOKINGS, SD) ; MUELLER; MATT R.;
(BROOKINGS, SD) ; MUTSCHELKNAUS; SHANNON LEE;
(BROOKINGS, SD) ; SCHULTE; JOSEPH G.; (BROOKINGS,
SD) ; BRAVEK; ERIC S.; (BROOKINGS, SD) ;
HANSEN; RYAN M.; (WATERTOWN, SD) |
Assignee: |
DAKTRONICS, INC.
BROOKINGS
SD
|
Family ID: |
39762260 |
Appl. No.: |
13/076857 |
Filed: |
March 31, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13047193 |
Mar 14, 2011 |
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13076857 |
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11786720 |
Apr 12, 2007 |
7907133 |
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13047193 |
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60791808 |
Apr 13, 2006 |
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Current U.S.
Class: |
345/211 ;
345/83 |
Current CPC
Class: |
G09G 2340/0457 20130101;
G09G 3/2003 20130101; G09G 3/32 20130101; G09F 9/3026 20130101;
G09G 2300/0452 20130101; G09G 2340/0428 20130101; G09G 2340/0407
20130101; G09G 2310/0224 20130101 |
Class at
Publication: |
345/211 ;
345/83 |
International
Class: |
G09G 3/32 20060101
G09G003/32; G06F 3/038 20060101 G06F003/038 |
Claims
1. An electronic display comprising: a first set of triangular LED
groupings, with each triangular LED grouping including adjacent
red, green and blue LEDs, and defined by two lines in a first
direction and three lines in a second direction; and a second set
of triangular LED groupings, with each triangular LED grouping
including adjacent red, green and blue LEDs, and defined by two
lines in the first direction and three lines in the second
direction, wherein the second set of triangular LED groupings is
offset from the first set of triangular LED groupings.
2. The electronic display of claim 1, wherein each intermediate
triangular LED grouping in the second set is positioned between an
adjacent pair of triangular LED groupings in the first set.
3. The electronic display of claim 1, wherein portions of the first
set of triangular LED groupings and portions of the second set of
triangular LED groupings combine to form an electronically
scannable line.
4. The electronic display of claim 1, further comprising: at least
a third set of triangular LED groupings, with each triangular LED
grouping including adjacent red, green and blue LEDs, and defined
by two lines in the first direction and three lines in the second
direction; and at least a fourth set of triangular LED groupings,
with each triangular LED grouping including adjacent red, green and
blue LEDs, and defined by two lines in the first direction and
three lines in the second direction, wherein the third set of
triangular LED groupings is offset from the second set of
triangular LED groupings and is aligned with the first set of
triangular LED groupings, and wherein the fourth set of triangular
LED groupings is offset from the third set of triangular LED
groupings and is aligned with the second set of triangular LED
groupings.
5. The electronic display of claim 1, wherein each triangular LED
grouping of the first and second sets are positioned and supported
on a circuit board.
6. The electronic display of claim 1, wherein the electronic
display is configured such that each individual LED of the first
and second sets of triangular LED groupings is individually
controlled.
7. The electronic display of claim 6, wherein the electronic
display is configured such that individual red LEDs, green LEDs,
and blue LEDs of two or more different triangular LED groupings are
grouped together in real time to form a separate triangular LED
grouping.
8. The electronic display of claim 1, wherein each triangular LED
grouping of the first and second sets is defined by two adjacent
rows in the first direction and three adjacent columns in the
second direction.
9. The electronic display of claim 1, wherein each triangular LED
grouping of the first and second sets is defined by two adjacent
columns in the first direction and three adjacent rows in the
second direction.
10. The electronic display of claim 1, wherein portions of adjacent
triangular LED groupings belonging to the first set and portions of
adjacent triangular LED groupings belonging to the second set
comprise an electronically scannable line.
11. The electronic display of claim 10, wherein each successive
scannable line, of a plurality of electronically scannable lines,
is interleaved with its preceding scannable line.
12. The electronic display of claim 11, wherein the interleaved
arrangement substantially prevents side angle color shift.
13. An electronic display comprising: a plurality of sets of
triangular LED groupings, the plurality of sets including
alternating even numbered sets and odd numbered sets, each
triangular LED grouping including a red LED, a green LED and a blue
LED, and defined by two adjacent lines in a first direction and
three adjacent lines in a second direction; each even numbered set
having a plurality of triangular LED groupings therein, each odd
numbered set having a plurality of triangular LED groupings therein
and offset relative to an even numbered set, with each intermediate
triangular LED grouping in the odd numbered set being positioned
between two adjacently-spaced triangular LED groupings in the even
numbered set.
14. The electronic display of claim 13, wherein portions of
adjacent alternating sets of triangular LED groupings comprise an
electronically scannable line.
15. The electronic display of claim of claim 14, wherein the number
of electrically scannable lines and the number of triangular LED
groupings in each electronically scannable line is sufficient to
provide a predetermined display area.
16. The electronic display of claim 13, wherein the plurality of
triangular LED groupings are positioned and supported on a circuit
board.
17. The electronic display of claim 13, wherein each triangular LED
grouping is defined by two rows in the first direction and three
columns in the second direction.
18. The electronic display of claim 17, wherein the red LED and the
blue LED of each triangular LED grouping are aligned in the first
direction.
19. The electronic display of claim 13, wherein each triangular LED
grouping is defined by two columns in the first direction and three
rows in the second direction.
20. The electronic display of claim 13, wherein each triangular LED
grouping includes a chevron LED grouping.
21. A method comprising: providing or obtaining an electronic
display including a plurality of sets of triangular LED groupings,
the plurality of sets including alternating even numbered sets and
odd numbered sets, with each triangular LED grouping including a
red LED, a green LED and a blue LED, and defined by two lines in a
first direction and three lines in a second direction, wherein the
triangular LED groupings of the even numbered sets are offset from
the triangular LED groupings of the odd numbered sets; and
operating the LEDs of the triangular LED groupings to provide a
display.
22. The method of claim 21, wherein operating the LEDs includes
individually controlling each LED of the electronic display.
23. The method of claim 21, wherein operating the LEDs includes
dynamically coupling individuals red LEDs, green LEDs, or blue LEDs
of two or more different triangular LED groupings in real time to
form a separate triangular LED grouping.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This patent application is a continuation of and claims
priority to U.S. application Ser. No. 13/047,193 (Attorney Docket
No. 339.044US2) filed Mar. 14, 2011, entitled "PIXEL INTERLEAVING
CONFIGURATIONS FOR USE IN HIGH DEFINITION ELECTRONIC SIGN
DISPLAYS," which claims priority to U.S. application Ser. No.
11/786,720 (Attorney Docket No. 339.044US1) filed Apr. 12, 2007,
now U.S. Pat. No. 7,907,133, entitled "PIXEL INTERLEAVING
CONFIGURATIONS FOR USE IN HIGH DEFINITION ELECTRONIC SIGN
DISPLAYS," which claims priority to U.S. Provisional Application
Ser. No. 60/791,808 (Attorney Docket No. 339.044PRV) filed Apr. 13,
2006, entitled "INTERLEAVED PIXEL CONCEPT (SMD-STYLE LEDS)," the
entirety of each of the disclosures of which are explicitly
incorporated by reference herein.
[0002] This patent application is related to U.S. application Ser.
No. 11/642,221 (Attorney Docket No. 339.034US2) filed on Dec. 20,
2006, currently pending, entitled "LED DISPLAY MODULE," which is a
continuation of U.S. application Ser. No. 11/271,404 (Attorney
Docket No. 339.034US1) filed Nov. 10, 2005, currently pending,
entitled "MODULAR DISPLAY SYSTEM."
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention to electronic sign displays and, more
particularly relates to pixel interleaving configurations for use
in high definition electronic sign displays.
[0005] 2. Description of the Prior Art
[0006] Prior art electronic sign displays have often incorporated a
plurality of light emitting diodes (LEDs) as a prime emitter of
light or points of light, whereby visual perception is processed by
the eye of a viewer as a graphic presentation. Electronic sign
displays have evolved from those having moderate resolution to
those having an improved degree of resolution approaching or
equaling high definition video, such as brought on by the advent of
high definition (HD) television devices. There is a desire for high
definition, i.e., high resolution, indoor or outdoor LED displays
reflecting the current trend in the ever increasing quest for
picture-like HD video quality. There are two primary standards for
HD video, one is 720p and the other is 1080i. The 720p standard
uses 720 progressively scanned lines of multiple pixel groups of
full color red, green and blue (RGB) LEDs, where each RGB LED group
constitutes a single pixel that collectively create a video image
frame for accumulated perception as an image by the human eye. For
example, a progressive scan could use 1/60th of a second for each
frame. The other standard is the 1080i standard, that supports 1080
lines of resolution by interleaved scanning. In interleaved
scanning, the odd lines are illuminated for 1/60th of a second
followed by the even scan lines for 1/60th of a second, giving a
full frame of data in 1/30th of a second. Each video standard is
independent of the light emitting technology, and therefore can be
supported by CRT (cathode ray tube), LCD (liquid crystal displays),
plasma, or LEDs (light emitting diodes). Light emitting diode
displays are often the preferred technology for large video
displays because they are capable of creating a high contrast,
bright display. Producing such high resolution light emitting
displays requires the addition of LEDs where the quantity of LEDs
is increased in great quantity to achieve desired clarity,
resolution, definition and brightness. Because every pixel in those
lines of resolution has a red, green, and blue component associated
with it, every pixel should have a red, green, and blue LED to
display all the video information available for that pixel element.
LEDs are a very significant percentage of the cost of an LED
screen, and therefore, a screen with 720 pixels high by some
arbitrary number of pixels wide can be extremely expensive and,
therefore, cost prohibitive for many users. Such an increase in the
number of LEDs required for high definition resolution use can be
problematic in terms of LED cost and in terms of energy usage. Size
limitations are also a cause of concern. There are two approaches
with respect to LED structuring when building a high definition
electronic sign display. One approach uses a plurality of
individual LEDs where each LED is an individual colored red, green,
and blue LED, thereby forming a pixel. The physical size of these
lamps along with the requirement to have at least three LEDs (red,
green, and blue) limits how tightly the spacing can be between full
color pixel elements. Alternatively, these lamp-style LEDs can be
inserted through the circuit board as part of an LED package
directly affixed to the face of the circuit board. This second
approach is a surface mount device (SMD) package that preferably
includes red, green, and blue LEDs in one package. Combining all
three color diodes into such a single SMD LED package allows for
tighter pixel spacing and is limited only by the size of the SMD
package itself. In addition to typical video format displays, there
are many applications pertaining to vertically small but very long
displays. Some examples of these applications include financial
ticker displays, or programmable electronic advertising displays,
such as Daktronics, Inc. ProAd.RTM. product often found in stadiums
and arenas. These displays are often between 1-4 feet tall, but can
be tens or even hundreds of feet long. Vertical pixel resolution
has a significant impact on the image quality of these displays and
is beneficial to advertisers who want a high quality image when
they are paying to advertise their product/company through the use
of such a device. Clearly what is desired is a solution addressing
the shortcomings of prior art devices where such a solution is
introduced by the present invention.
SUMMARY OF THE INVENTION
[0007] The general purpose of the present invention is to provide
pixel interleaving configurations for use in high definition
electronic sign displays. The invention includes one or more red,
green, and blue LED pixel configurations that are useful for
optimizing the vertical resolution of LED video displays,
especially high definition electronic sign displays. The following
are key features or attributes of the invention:
[0008] 1. Any pixel has at least 1 red, 1 green, and 1 blue (RGB)
light emitting diode to form a full color element, but may be in
different or varying configurations or native pixel arrangements,
such as, but not limited to, the following basic configurations,
whereby a pixel includes either: (a) individual LEDs including a
grouping preferably of at least one red LED, one green LED, and one
blue LED elements consisting of solely vertical LED alignment or
consisting of triangular alignment or any other suitable
arrangement; or (b) SMD (Surface Mount Device) LED packages of
multiple elements including one red LED, one green LED, and one
blue LED being closely grouped therein preferably in chevron
(triangular alignment) style or other suitable arrangement.
[0009] 2. There are odd and even lines of pixels. The even lines
are horizontally offset from the odd lines to allow for tighter
vertical pixel spacing while using either three individual
(separate) red, green, blue LEDs or while using SMD LED packages
according to 1. above.
[0010] 3. The LED spacing within an individual LED (red, green,
blue) style pixel or spacing from pixel-to-pixel can be flexible.
Spacing of the LEDs may be compacted within the pixel to ease
manufacturing and, as such, pixel boundaries can easily be visually
seen and identified), or uniform spacing can be used to create an
even fill-factor across the LED sign where the pixel boundaries
blend together, preferably making it difficult to visually identify
which individual LEDs belong with which pixel.
[0011] 4. Pixel arrangements are scaleable as the pixel pitch
between interleaved 3-in-1 SMD LED package pixels or separate red,
green, blue SMD pixels is not limited to designs at 4 mm, 12.5 mm,
25 mm and the like, but can be implemented on any pitch between the
pixels. This scaleability allows this invention to be used to
develop a family of devices with a wide ranging offering of pixel
spacing that can be used to build a sign format with the optimal
viewing properties for any display applications.
[0012] According to one or more embodiments of the present
invention, there are provided pixel interleaving configurations for
use in high definition electronic sign displays where each scanned
pixel includes a full complement of colored LEDs including the
colors of red, green, and blue.
[0013] One significant aspect and feature of the present invention
is an interleaved display where each scanned pixel includes red,
green, and blue representation.
[0014] Another significant aspect and feature of the present
invention is the offset of a succeeding line of pixels with a
previous line of pixels.
[0015] Still another significant aspect and feature of the present
invention is the reduction in the number of LEDs required in an
electronic sign display by the use of interleaving of pixels while
still maintaining a balanced and full red, green, and blue color
representation in each scan row, often referred to as full color
rows of resolution.
[0016] Yet another significant aspect and feature of the present
invention is the use of pure pixel display concepts instead of
virtual or dynamic pixeling.
[0017] A further significant aspect and feature of the present
invention is the use of full color row resolution which does not
experience color shift, which upholds high image and color quality,
and which maintains high definition capabilities.
[0018] A still further significant aspect and feature of the
present invention is that full color pixel content is provided for
even use of the LEDs, whereby all LEDs age at an even rate.
[0019] A still further significant aspect and feature of the
present invention decreases LED density while maintaining the
number of full color resolution rows.
[0020] A further significant aspect and feature of the present
invention prevents side angle color shift that occurs when LEDs are
packed very closely together.
[0021] Having thus briefly described embodiments of the present
invention and having mentioned some significant aspects and
features of the present invention, it is the principal object of
the present invention to provide pixel interleaving configurations
for use in high definition electronic sign displays.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Other objects of the present invention and many of the
attendant advantages of the present invention will be readily
appreciated as the same becomes better understood by reference to
the following detailed description when considered in connection
with the accompanying drawings, in which like reference numerals
designate like parts throughout the figures thereof and
wherein:
[0023] FIG. 1 is a segmented view showing a pixel interleaving
configuration for use in high definition electronic sign displays,
the present invention;
[0024] FIG. 2 and FIG. 3 are an overview of interleaving of pixels
showing the use of LED packages (pixels) such as described and
arranged in FIG. 1;
[0025] FIG. 4 shows LED packages (pixels) arranged in true pixel
configuration;
[0026] FIG. 5 for the sake of comparison shows a prior art
virtual/dynamic pixel arrangement incorporating single colored LEDs
which form pixels accounted for in various configuration
designations such as known in the art;
[0027] FIG. 6 is a segmented view showing a pixel interleaving
configuration for use in high definition electronic sign displays
where a plurality of individual LEDs form pixels;
[0028] FIG. 7 is an illustration showing interleaving of pixels
comprised of individual LEDs such as described and arranged in FIG.
6; and,
[0029] FIG. 8 illustrates resolution enhancement such as offered by
interleaving.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] FIG. 1 is a segmented view showing a pixel interleaving
configuration 10 for use in high definition electronic sign
displays where a plurality of LED packages are arranged and mounted
on a circuit board 12 which can be part of a high definition
electronic sign display. The LED packages, each of which are a
pixel, are arranged in alternating style having odd numbered rows
13, 15, 17, 19, and so on, alternating with even numbered rows 14,
16, 18, 20, and so on, where the even numbered rows 14, 16, 18, 20,
and so on, are offset from the odd numbered rows 13, 15, 17, 19,
and so on. Correspondingly, the LED packages are arranged in
alternating style having columns A, C, E and G, and so on,
alternating with columns B, D, F, H, and so on, where the columns
B, D, F and H are offset from the columns A, C, E and G, and so on.
The LED packages can be identified according to row and column. For
example, the upper left LED package would be LED package 13A, the
LED package beneath would be LED package 15A, and so on. An
enlarged copy of the LED package 13A is shown distanced from the
other LED packages. The LED package 13A and each of the other
similar LED packages are a pixel, each including LED elements which
can be generally smaller than individual LEDs which are a red LED,
a green LED, and a blue LED indicated by the letters R, G and B
arranged in chevron or triangular style or other suitable
style.
[0031] FIG. 2 and FIG. 3 are used for an overview of interleaving
pixels showing the use of LED packages (pixels), such as described
and arranged in FIG. 1. For example, and as in FIG. 2, LED packages
13A, 13C, 13E, 13G, 15A, 15C, 15E, 15G, 17A, 17C, 17E, and 17G are
distributed with the center of each aligned on vertical and
horizontal 8 mm centers, thus creating pixels spaced at 8 mm. A
proportionate number of additional pixels 14B, 14D, 14F, 14H, 16B,
16D, 16F, 16H, 18B, 18D, 18F and 18H (FIG. 3) are then
interleavingly distributed in uniform fashion as shown in FIG. 3,
substantially between or suitably spaced as illustrated with
reference to LED packages 13A, 13C, 13E, 13G, 15A, 15C, 15E, 15G,
17A, 17C, 17E, and 17G in alignment with other and additional
offset vertical and horizontal 8 mm centers resulting in another 8
mm spaced interleaved pixel arrangement, where the term "pixel
interleaving" or "interleaved" is in preferred use by Daktronics,
Inc. of Brookings, S. Dak. More precisely, LED package 14B is
centrally located in the space below LED packages 13A and 13C and
above LED packages 15A and 15C, the LED package 16B is centrally
located in the space below LED packages 15A and 15C and above LED
packages 17A and 17C, and so on in the same fashion. Other LED
packages are not shown for the purpose of brevity and clarity. Such
an arrangement of LED packages (pixels) results in an interleaved
arrangement of LED packages (pixels) with 4 mm vertical and
horizontal spacing. By using positional pixel processing, that
processes the signal in relation to the location of the pixel, the
colors blend with their own pixel but the viewer's eyes also blend
with the color produced by a neighboring pixel. With this type of
interleaved layout combined with positional pixeling technology,
which can also be referred to as "pure pixel", a term which is in
preferred use by Daktronics, Inc. of Brookings, S. Dak., each and
every pixel and, therefore, each and every scan line is full color
resulting in a blend of efficiency and accuracy having the
capability to reproduce all the color depth and detail present in
the original image signal. In the illustration provided by FIG. 3,
24 LED packages using interleaved "pure pixel" design are used,
whereas 48 LED packages are used in the illustration provided in
FIG. 4 using a non-interleaved "true pixel" design, a term which is
in preferred use by Daktronics, Inc. of Brookings, S. Dak.,
obviously providing an economical solution to pixel quantity where,
in FIG. 4, LED packages (pixels) are shown arranged in rows 21
through 26 and columns A through H. Such economy is more
significant when comparing larger high definition electronic sign
displays. For example, such an interleaving using the 4 mm
interleaved pixel spacing of FIG. 3 requires 3,906 LED packages
using interleaved pixel design to populate a one square meter high
definition electronic sign display which, significantly, is half of
the 7,812 LED packages required to populate a "true pixel" high
definition electronic sign display represented in FIG. 4 having 4
mm pixel spacing. Such interleaved configurations can be scaled to
larger spacings. For instance, larger LED packages (pixels) having
correspondingly larger LEDs or individual red, green, and blue LEDs
in groups (pixels) can be scaled upwardly to include, for example,
8 mm, 12.5 mm, 16 mm and the like. For example, a pure pixel
(interleaved) design having 12.5 mm spacing using individual LEDs
would require the use of 3200 red LEDs, 3200 green LEDs, and 3200
blue LEDs to populate a one square meter high definition electronic
sign display, whereas a "true pixel" design having 12.5 mm spacing
would required the use of 6400 red LEDs, 6400 green LEDs, and 6400
blue LEDs to populate a one square meter high definition electronic
sign display.
[0032] For comparison, FIG. 5 shows a prior art virtual/dynamic
pixel arrangement incorporating single colored LEDs which form
pixels which can be accounted for in various configuration
designations, such as known in the art where single colored LEDs
are arranged in rows 27 through 32 and columns A through H of 4 mm
vertical and horizontal spacing. Use of the interleave pixel
spacing as described in FIG. 3 provides for scans involving the
availability of red, green, and blue elements for use in each scan
line. For example, a scan of line 13 of FIG. 3 involves the
availability of four red LED elements, four green LED elements, and
four blue LED elements of the LED packages 13A, 13C, 13E and 13G,
whereas a scan of a corresponding line 27 of FIG. 5 involves the
availability of four red LEDs, zero green LEDs, and four blue LEDs
where green LEDs are under-represented, i.e., nonexistent. In a
similar fashion, a scan of line 14 of FIG. 3 involves the
availability of four red LED elements, four green LED elements, and
four blue LED elements of the LED packages 14B, 14D, 14F and 14H,
whereas a scan of a corresponding line 28 of FIG. 5 involves the
availability of four red LEDs, four green LEDs, and zero blue LEDs
where blue LEDs are under-represented, i.e., nonexistent.
Additional following scan patterns repeatingly exhibit the same
characteristics where a shortage of green and blue color
representation exists with reference to the scan lines of the
virtual/dynamic pixel arrangement shown in FIG. 5 and where,
preferably, an even and balanced red, green, and blue color
representation exists with reference to the scan lines of the
interleaved pixel arrangement shown in FIG. 3. It is noted that the
interleaved pixel arrangement of FIG. 3, like the "true pixel"
arrangement of FIG. 4, includes scan lines of full color
representation.
[0033] FIG. 6 is a segmented view showing a pixel interleaving
configuration 10a for use in high definition electronic sign
displays where a plurality of individual LEDs form pixels which are
arranged for use on a circuit board 34 which can be part of a high
definition electronic sign display. Each pixel consists of an
individual red LED, an individual green LED, and an individual blue
LED in vertical alignment where the pixels are arranged in
alternating style having odd numbered rows 35, 37, 39 and so on
alternating with even numbered rows 36, 38, 40 and so on where the
even numbered rows 36, 38, 40 are offset from the odd numbered rows
35, 37, 39. Correspondingly, the pixels are arranged in alternating
style having columns A, C, E, G and so on alternating with columns
B, D, F, H and so on where the columns B, D, F, H are offset with
respect to the columns A, C, E, G, whereby the pixels can be
identified according to row and column. For example, the upper left
pixel would be pixel 35A, the pixel beneath would be pixel 37A and
so on. An enlarged copy of the pixel 35A is shown distanced from
the other pixels. The pixel 35A and each of the other pixels are
similar in construction.
[0034] FIG. 7 is an illustration showing interleaving of pixels
comprised of individual LEDs, such as described and arranged in
FIG. 6. For example, and as in FIG. 6, pixels 35A, 35C, 35E, 35G,
37A, 37C, 37E, 37G, 39A, 39C, 39E, and 39G are distributed with the
center of each (a green LED) aligned on vertical and horizontal
12.5 mm centers thus creating pixels spaced at 12.5 mm. A
proportionate number of additional pixels 36B, 36D, 36F, 36H, 38B,
38D, 38F, 38H, 40B, 40D, 40F and 40H are interleavingly distributed
in uniform fashion substantially between or suitably spaced as
illustrated with reference to pixels 35A, 35C, 35E, 35B, 37A, 37C,
37E, 37G, 39A, 39C, 39E, and 39G in alignment with other and
additional offset vertical and horizontal 12.5 mm centers resulting
in an 12.5 mm spaced interleaved pixel arrangement, where the term
"pixel interleaving" or "interleaved" is in preferred use by
Daktronics, Inc. of Brookings, S. Dak. More precisely, pixel 36B is
centrally located in the space below pixels 35A and 35C and above
pixels 37A and 37C, the pixel 38B is centrally located in the space
below LED pixels 37A and 37C and above pixels 39A and 39C and so on
in a suitable fashion. Other pixels are not shown for the purpose
of brevity and clarity. Such an arrangement of pixel results in an
interleaved arrangement of pixels with 12.5 mm vertical and
horizontal spacing. By using positional pixel processing, the
colors blend with their own pixel but the viewer's eyes also blend
with the color produced by a neighboring pixel. With this type of
interleaved layout, which can also be referred to as "pure pixel",
a term which is in preferred use by Daktronics, Inc. of Brookings,
S. Dak., each and every pixel and, therefore, each and every scan
line is full color resulting in a blend of efficiency and accuracy
having the capability to reproduce all the color depth and detail
present in the original image signal. For example, a scan of line
35 of FIG. 7 involves the availability of four red LED elements,
four green LED elements, and four blue LED elements of the pixels
35A, 35C, 35E and 350. In a similar fashion, a scan of line 36
involves the availability of four red LED elements, four green LED
elements, and four blue LED elements of the pixels 36B, 36D, 36F
and 36H. Additional following scan patterns repeatingly exhibit the
same characteristics where, preferably, an even and balanced red,
green, and blue color representation exists with reference to the
scan lines of the interleaved pixel arrangement shown in a manner
such as previously described with reference to FIG. 3. It is noted
that the interleaved pixel arrangement of FIG. 7, like the "true
pixel" arrangement of FIG. 4, includes scan lines of full color
representation.
MODE OF OPERATION
[0035] FIG. 8 illustrates resolution enhancement such as offered by
interleaving, such as shown in FIG. 7. Individual control of red,
green, and blue LEDs is exercised over each individual red, green,
or blue LED regardless of the native pixel in which each is
contained. Such control includes, but is not limited to, operating
or not operating the desired colored individual LED and operation
of an individual LED at a desired intensity. Individual red, green,
and blue LEDs are grouped in real time to increase the perceived
line count and overall resolution of a high definition electronic
sign display. Such a sub-pixel processing method effectively
doubles the native full-color count of the display to deliver
smoother curves and greater image detail. Interleaved scanning is
used to produce a set of alternating scan lines that are odd or
even numbered. Consider scan line 1 (an odd number scan line) and
scan line 2 (an even number scan line) during positional pixel
processing where the human eye visually and temporally combines LED
colors perceived in a 720 line frame. In scan line 1, the colors of
a complete group of red green, and blue LEDs are perceived to be
located as shown encircled by an ellipse albeit the LEDs reside in
different native pixels, i.e., the blue and green LEDs of pixel 35A
and the red LED of the partial pixel above pixel 36B are involved.
This sequence repeats along scan line 1 and the other odd scan
lines where each incremental portion of each scan line includes
red, blue and green LEDs. Immediately following a full scan along
scan line 1 and all following odd scan lines, another scan along
scan line 2, and all following even scan lines, are initiated
beginning with the green and red LEDs of pixel 35A and the blue LED
of pixel 36B. The very next scan of line 2 proceeds to another
complete group of red, green, and blue LEDs involving the blue LED
of pixel 36B and the green and red LEDs of pixel 35C. This sequence
repeats along scan line 2 where each incremental portion of scan 2
includes red, green, and blue LEDs until completing a full scan of
even numbered scan lines. Hence, scan line 1 is painted on using
the image information from the scan line 1 of the incoming image,
and scan line 2 is painted on with the information from scan line 2
of the incoming image. The shared green LED in this example is
imbued with information from both scan line 1 and scan line 2 in
relation to the position of this shared green LED. The positional
information involves a combination of an interpolated site
(weighted average), as well as filters, to remove false color
artifacts. Consider scan line 2 and scan line 3, the red and blue
LEDs are shared devices on these two lines. The information used to
drive these LEDs is a weighted average of the incoming scan lines 2
and 3 with the weighting of the average oriented to the location of
these red and blue LEDs. The weighted averaging is performed before
transmission of data to the display. To minimize the transmission
overhead of the extra information of the shared devices, the green
LEDs that are shared on scan lines 1 and 2 are transmitted as part
of the information for the blue and red LEDs of scan line 1. The
positional image information that is shared on the red and blue
devices between scan lines 2 and 3 is transmitted with the
information for the green LEDs on scan line 3. This decimation of
transmitted data allows for control of the full color scan lines
without increasing the transmission bandwidth. Although the pixels
are vertically spaced at 12.5 mm each, scan line centers at 6.25 mm
spacing where each scan line includes a full compliment of red,
green, and blue LEDs as opposed virtual/dynamic pixel arrangements
which lack in full color complements for each scan line. Scanning
continues in this sequence along the entire frame to achieve 720
scan lines of full red, green, and blue color resolution. Arranging
the pixels in interleaving fashion provides spacing which prevents
side-angle color shift that occurs when LEDs are packed very
closely together and creates situations where the plastic lens of
LED devices shoulders and blocks the light of other LEDs. The
positional pixel processing technology can also be applied to the
pixel interleaving configuration 10a shown and described starting
in FIG. 1.
[0036] Various modifications can be made to the present invention
without departing from the apparent scope thereof.
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