Scaleable tiled flat-panel projection color display

A flat-panel projection color display including a flat projection display screen having a width dimension and a height dimension defining a display screen area A, the display screen having a light transmissive support which has on one surface thereof a plurality of patterned fluorescent elements capable of emitting red, green, or blue color light and at least one laser scanner for producing a raster-scanned laser light beam and for projecting the beam onto the display screen as a display tile from a projection distance which is .ltoreq.0.5.sqroot.A. The display screen causes the laser light beam to illuminate selected fluorescent elements within the display tile on the screen, the laser light beam having a wavelength selected to cause the selected fluorescent elements to emit red, green, or blue color light.

FIELD OF THE INVENTION 
The present invention generally relates to displays and, more particularly, 
to a scaleable tiled flat-panel projection color display comprised of at 
least one laser scanner and a flat projection display screen. 
BACKGROUND OF THE INVENTION 
Recent years have seen the rapid development of displays based on liquid 
crystal display systems, cathode ray tube (CRT) display systems, organic 
electroluminescent display systems, and laser-based display systems. A 
portion of the display system development efforts appear to be directed to 
large area displays and, more particularly, to large area flat-panel 
displays. For example, in a publication by A. Abileah and Z. Yaniv, titled 
"Optical Tiled AMLCD for Very Large Display Applications", SPIE, Vol. 
1664, High Resolution Displays and Projection Systems, pp 241-243, 1992, 
there is described a method of tiling a number of flat-panel liquid 
crystal displays (LCDs) to a continuous large display using magnifying 
fiber optic faceplates to cover the gaps between adjacent displays. R. 
Samadani, J. Lanham, D. Loomis, L. Silverstein, and J. Larimer, in a 
publication titled "Periodic Plane Tilings: Application to Pixel Layout 
Simulations for Color Flat-Panel Displays," Journal of the SID, Vol. 2/2, 
pp 95-104, 1994 discuss algorithms for pixel tilings and at minimizing a 
potentially objectionable observation of individual pixels in a display of 
pixels. U.S. Pat. No. 5,015,999 discloses a display unit for displaying 
two-dimensional images in which a two-dimensional array of organic 
electroluminescent elements emits ultraviolet light which is directed to a 
fluorescent screen having fluorescent materials emitting different colors 
of visible light. In a PCT International Patent Application No. WO 
94/18802, there are disclosed methods and apparatus for image projection 
using linear laser arrays, with each laser array generating multiple 
parallel output beamlets at one of the three primary colors (red, green, 
and blue), combining the beamlets of the three colors into a plurality of 
white light beamlets which are then raster scanned in an optical scanning 
and projection system to be projected onto a screen. U.S. Pat. No. 
5,424,771 discloses a video display device using laser generated 
radiation, in which respective red, green, and blue laser beams are 
combined and raster scanned by a rotating polygon and rotating lenses for 
projection onto a wall or a large, white surface. And U.S. Pat. No. 
5,473,396 discloses a display apparatus in which ultraviolet emitting CRTs 
emit radiation representing red, green, and blue image information and 
projecting these UV emissions onto a large size fluorescent screen having 
a pattern of fluorescent materials which emit visible red, green, and blue 
light upon excitation by the UV rays from the CRTs. 
While LCDs, in general, can be considered as flat-panel displays, their 
utility in providing very large area displays is restricted to the LCD 
used as a light valve in projection. Thus, an LCD light valve display is a 
display having a long projection distance and is, therefore, not a 
flat-panel projection display. CRT-based display devices become 
impractical for large display screen sizes and can not generally be 
considered in applications as flat-panel display systems due to the 
physical dimensions of cathode ray tubes. Display systems based on organic 
electroluminescent light emitting elements can be viewed as flat-panel 
displays, however, the display screen size or display screen area is 
limited by the size or area of available substrates for forming the 
organic electroluminescent elements. 
Display systems utilizing laser light sources offer the principal 
advantages of high brightness and optical coherence of a laser beam over a 
distance sufficient to afford manipulation of the beam by beam deflection 
elements and beam scanning elements so as to make possible laser beam 
projection onto a display screen of a relatively large display screen 
area. In particular, the advent of semiconductor lasers (also referred to 
as laser diodes) has offered the possibility for display system designers 
to advance more compact laser-based display systems than was possible when 
more bulky gas laser sources were used. 
In order to provide on a display screen a two-dimensional representation of 
information, a laser beam or laser beams, suitably intensity modulated, 
are projected onto the screen in a raster pattern which is generated in 
the form of horizontal laser beam scanlines which are advanced vertically 
along the display screen as a sequence of parallel scanlines. These 
horizontal scanlines are produced by sweeping a laser beam or laser beams 
across the display screen through reflection of the beams off the surfaces 
of multifaceted rotating polygonal mirrors. Each successive horizontal 
scanline is displaced vertically from a previous horizontal scanline by a 
second reflector which is also known as a galvanometer reflector. While 
the operational reliability of rotating multifaceted polygonal mirrors has 
been improved, such laser beam steering systems are complex and expensive. 
Moreover, particulate contamination or haze formation of one or several 
mirror facets would adversely affect the performance of such rotating 
laser beam deflectors. Accordingly, it is desirable to provide horizontal 
laser beam deflection or horizontal laser beam scanline formation by a 
non-rotating deflector element. 
Currently known laser-based color projection systems deploy a fixed number 
of laser light sources, for example, a linear array of red light emitting, 
green light emitting, and blue light emitting laser sources, respectively. 
In such projection display systems, the viewable display area on a screen 
can, in principle, be increased from one area to a larger area by 
increasing the distance between the laser beam projection source and the 
screen. Stated differently, currently known laser projection display 
systems provide a fixed information content on a display screen, 
irrespective of the area covered by the display. Accordingly, it is 
desirable to provide a laser-based scaleable flat-panel color projection 
display in which both the number of laser light sources illuminating a 
display screen, and the display area of the screen can be readily scaled 
so as to meet user needs for projection displays which extend from 
relatively small area flat-panel color displays to relatively large area 
flat-panel color displays. 
Presently known color projection display systems use a plurality of laser 
light sources dedicated to provide a plurality of primary color laser 
beams, followed by elements dedicated to combining these differently 
colored laser beams prior to a beam scanning or a beam rastering assembly. 
Thus, such systems require optically refractive and optically reflective 
elements capable of performing designated functions over a broad spectral 
range extending from red light to blue light. In order to achieve a 
comparable optical efficiency throughout that relatively broad spectral 
range, optical elements tend to require a more complex design which, in 
turn, increases the cost of such elements. Accordingly, it is desirable to 
provide a flat-panel projection display which uses a plurality of laser 
scanners each generating a raster-scanned laser light beam of one and a 
same wavelength, and generating a full-color display on a patterned 
fluorescent full-color display screen by projecting the raster-scanned 
laser light beams thereon. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a flat-panel projection 
color display. 
It is another object of the present invention to provide a scaleable tiled 
flat-panel projection color display. 
The object of providing a flat-panel projection color display is achieved 
by a flat-panel projection color display, comprising: 
a) a flat projection display screen having a width dimension and a height 
dimension defining a display screen area A, the display screen having a 
light transmissive support which has on one surface thereof a plurality of 
patterned fluorescent elements capable of emitting red, green, or blue 
color light; 
b) at least one laser scanner for producing a raster-scanned laser light 
beam and for projecting the beam onto the display screen as a display tile 
from a projection distance which is .ltoreq.0.5.sqroot.A; and 
c) means for causing the laser light beam to illuminate selected 
fluorescent elements within the display tile on the screen, the laser 
light beam having a wavelength selected to cause the selected fluorescent 
elements to emit red, green, or blue color light. 
The object is also achieved by providing a scaleable tiled flat-panel 
projection color display, comprising: 
a) a projection display screen of area A having a light transmissive 
support, a plurality of patterned fluorescent elements on one surface of 
the support capable of emitting red, green or blue light; 
b) the display screen area A being subdivided into a plurality of identical 
display tiles, each individual display tile having an area A.sub.t and 
being seamlessly contiguous to at least one other display tile; 
c) a plurality of identical laser scanners arranged to form a 
two-dimensional array, each laser scanner being capable of projecting a 
laser beam onto a designated display tile for illuminating the patterned 
fluorescent elements; 
d) a projection distance D being defined as the distance from the laser 
scanner to the display screen, is .ltoreq.0.5.sqroot.A.sub.t ; and 
e) the area of an individual display tile A.sub.t being selected to be in 
the range of from 0.01 to 0.1 times the area A of the projection display 
screen. 
The object is also achieved by providing a scaleable tiled flat-panel 
projection color display, comprising: 
a) a flat projection display screen scaled to a selected width dimension 
and to a selected height dimension defining a selected display screen area 
A, the screen having a light transmissive support which has on one surface 
thereof a plurality of patterned fluorescent elements capable of emitting 
red, green, or blue light; and a plurality of identical laser scanners 
arranged to form a two-dimensional laser scanner array, the plurality of 
laser scanners of the two-dimensional array scaled in accordance with the 
scaled selected width and height dimensions of the display screen, each 
laser scanner of the two-dimensional array producing a raster-scanned 
laser light beam and projecting the beam onto the display screen as a 
designated display tile from a projection distance which is 
.ltoreq.0.5.sqroot.A, the laser light beam illuminating selected 
fluorescent elements within the designated display tile on the screen, 
each laser light beam having a wavelength selected to cause the selected 
fluorescent elements to emit red, green, or blue light, the plurality of 
the laser scanners of the two-dimensional scaled array projecting 
corresponding laser light beams onto the display screen as seamlessly 
abutting designated display tiles across a substantial portion of the 
display screen area, each of the designated display tiles having a tile 
width dimension and a tile height dimension defining a tile area which is 
in a range of from 0.01 to 0.1 times the display screen area A. 
ADVANTAGES 
Major advantages of the flat-panel projection display of the invention are: 
the display size or display area is scaleable to large areas without 
increasing the depth dimension, i.e. the projection distance, of the 
display; the fluorescent color display screen provides a continuous and 
seamless display of any size dimension; the fluorescent color display 
screen illuminated by laser light beams from laser scanner arrays provides 
a high display brightness; the fluorescent display screen can be 
manufactured using flexible and lightweight screen support materials such 
as, for example, plastic support materials; the laser scanners are modular 
to provide ease of assembly and ease of repair; each laser scanner 
produces a laser light beam having one and the same single wavelength of 
light, rather than the red, green, and blue (R, G, B) light laser light 
beams required of prior art laser projection color displays; and the 
fluorescent display screen can be produced economically on a support by 
high speed printing processes or by large area photolithographic processes 
.

DETAILED DESCRIPTION OF THE INVENTION 
Referring now to FIG. 1, there is shown a schematic perspective view of a 
flat-panel projection color display generally designated at 10, having a 
flat projection display screen 200 disposed in a projecting relationship 
with respect to at least one laser scanner 100 of which only one vertical 
raster generator 150 (an oscillating mirror) is shown for purposes of 
clarity. The vertical raster generator 150 of the laser scanner 100 
projects onto the display screen 200 a laser light beam as a display tile 
T from a projection distance D. The projection distance D is the distance 
between the surface of the screen 200 onto which the laser light beam is 
projected and the vertical raster generator 150 when the laser light beam 
is at the center of the display tile T. The display tile T has width and 
height dimensions w and h which define a display tile area A.sub.t. The 
display screen 200 has a width dimension W and height dimension H defining 
a display screen area A. The flat-panel projection display 10 is defined 
in that the projection distance D is .ltoreq.0.5.sqroot.A, i.e. less than 
or equal to 0.5 times the square root of the display screen area A of the 
display screen 200. 
The display tile T projected onto the display screen 200 has a tile area 
A.sub.t defined by the product h.times.w of the height and width 
dimensions of the tile. For a selected display screen area A=H.times.W, 
the tile-center projection distance D from the display screen 200 to the 
vertical raster generator 150 of a laser scanner is at most equal to 
.ltoreq.0.5.sqroot.A to maintain the flat-panel configuration of the 
display 10, as indicated above. The tile area A.sub.t of the projected 
tile T is directly related to the projection distance D and to the beam 
deflection capacity of a laser scanner of the present invention in the 
horizontal and vertical direction S. An additional requirement is that the 
aspect ratio w/h of the display tile T be substantially identical to the 
aspect ratio W/H of the display screen 200, for example an aspect ratio of 
4/3. This latter requirement will be more readily appreciated when 
considering a plurality of laser scanners projecting a plurality of 
seamlessly abutting display tiles onto the display screen over 
substantially the full screen area A, as will be described with reference 
to FIGS. 5, 6, 7B, and 7C. In view of the above considerations, the tile 
area A.sub.t is preferably in a range of from 0.01 to 0.1 times the 
display screen area A. 
As will be described hereinafter, the color display screen 200 has a light 
transmissive support which has, on one surface, a plurality of patterned 
fluorescent elements capable of emitting red, green, or blue light, 
respectively, in response to illumination by a laser light beam having a 
selected wavelength, and which is produced by a laser scanner and 
projected onto the screen by the laser scanner's vertical raster generator 
150. The emitted light 250 from selected fluorescent elements illuminated 
by the laser light beam is viewed by a user of the flat-panel projection 
display 10. 
Referring now to FIGS. 2A and 2B, a schematic plan view and a schematic 
side view, respectively, of a laser scanner 101-11 is depicted as 
projecting a tile T(1;1) onto a color display screen 200. The 
sub-designations "-11" refer to parts or functions which are dedicated to 
projecting a tile T(1;1) onto the screen 200. 
On a support 181-11 are disposed along optical axes a laser diode 110-11 
emitting a laser light beam 113-11 which is directed onto a horizontal 
scanline generator 114-11. In the embodiment shown in FIGS. 2A and 2B, the 
horizontal scanline generator 114-11 is a vibrating mirror, as indicated 
by the double arrows. The vibrating mirror forms horizontal scanlines by 
periodically deflecting the laser beam in a substantially horizontal 
direction. The horizontal scanline generator 114-11 directs the deflected 
laser beam onto a vertical raster generator 150-11, which is an 
oscillating mirror having a raster scan interval and a return interval. It 
is the vertical raster generator 150-11 which projects the tile T(1;1) 
onto the surface 220 of patterned fluorescent elements of the color 
display screen 200 as a raster-scanned laser light beam. The screen 200 
has a light transmissive support 210 through which the red, green, and 
blue emitted light 250 is directed toward a viewer. 
The laser light beam 113-11 emitted by the laser diode 110-11 has 
preferably a wavelength selected to be in the range of from 400-430 nm 
which causes the fluorescent elements disposed on the surface 220 of the 
display screen 200 to emit red, green, or blue light, respectively. 
It will be appreciated that the vertical raster generator 150-11 in FIG. 2B 
is shown in a plane located above the plane of the laser light beam 133-11 
for simplicity of presentation. Accordingly, the vibrating mirror 114-11 
(horizontal scanline generator) is depicted as slightly tilted. 
The laser diode 110-11 can be a frequency-doubled infrared laser diode, and 
alternatively, it can be a laser diode capable of emitting a beam of light 
in a wavelength range from 400-430 nm directly. It will be appreciated 
that a suitably configured laser scanner controller (not shown) can 
provide laser diode drive signals capable of modulating the intensity of 
the emitted laser light beam 113-11 in response to a controller input 
signal, and that such a laser scanner controller provides synchronized 
drive signals to the horizontal scanline generator 114-11 and to the 
vertical raster generator 150-11, thereby producing and projecting onto 
the display screen a raster-scanned laser light beam which illuminates 
selected fluorescent elements within the display tile T(1;1). 
Referring now to FIGS. 3A and 3B, there are depicted a schematic plan view 
and a schematic side view, respectively, of a laser scanner 101-11 
projecting a tile T(1;1) onto a surface 220 of a flat projection color 
display screen 200, with like numerals designating like parts or functions 
as described previously with reference to FIGS. 2A and 2B. 
The laser scanner 101-11 depicted in FIGS. 3A and 3B differs from the laser 
scanner of FIGS. 2A and 2B in that a horizontal scanline generator 115-11 
is a non-vibrating optoelectronic device adapted to receive the laser 
light beam 113-11 at one surface, and to provide from another surface a 
horizontally deflected laser beam comprising the horizontal scanlines. The 
horizontally reflected laser beam is directed onto a concave beam 
reflector 141-11 which directs the horizontal scanlines onto the vertical 
raster generator 150-11 at a reduced scanline length dimension. As 
indicated previously, the vertical raster generator 150-11 projects the 
raster-scanned laser light beam onto the surface 220 of the color display 
screen 200 as a display tile. 
The horizontal scanline generator 115-11 is a solid-state optoelectronic 
device, preferably fabricated from ferroelectric materials and having a 
design which is functionally equivalent to the beam deflection portion as 
shown particularly in FIGS. 6A, 6B, and a FIG. 7 of commonly assigned U.S. 
Ser. No. 08/268,373 filed Jun. 29, 1994 titled "Ferroelectric Light 
Frequency Doubler Device With a Surface Coating and Having an Inverted 
Domain Structure" to Gupta et al, the disclosure of which is incorporated 
here by reference. 
Referring now to FIG. 4, there is shown a more detailed schematic side view 
of a single laser scanner described above with reference to FIGS. 3A and 
3B. A laser diode 110-11 and a laser beam shaping optical element 111-11 
are disposed in a common housing 112-11. The beam shaping optical element 
111-11 serves to circularize a beam of noncircular cross section emitted 
by virtually all types of laser diodes. The circularized laser beam 113-11 
is directed toward an entrance surface (not particularly designated) of a 
horizontal scanline generator 115-11 which provides, at an exit surface 
(not particularly designated) thereof a periodically horizontally 
deflected laser beam in a horizontal plane. This periodically horizontally 
scanning beam is directed by the concave beam reflector 141-11 onto the 
reflective surface of the vertical raster generator 150-11. 
The vertical raster generator 150-11 is oscillated via a shaft 157 which is 
driven by a drive motor 155 so as to provide a raster scan interval and a 
return interval in response to appropriate motor drive signals applied 
thereto from a laser scanner controller (not shown). During the raster 
scan interval, the mirrored front surface of the vertical raster generator 
projects onto the surface 220 of the display screen 200 the tile T(1;1) as 
a raster scanned laser light beam of horizontal scanlines SL (parallel to 
an x-direction) and rastered vertically (along a y-direction). The arrows 
indicate the start of each scanline, and the scanlines are shown in dashed 
outline to indicate that the laser light beam 113-11, and thus its 
projection onto the screen, is intensity modulated, thereby illuminating 
only selected fluorescent elements within the display tile T(1;1) on the 
surface 220 which has a plurality of patterned fluorescent elements 
capable of emitting red, green, or blue light, respectively, upon 
illumination by the raster scanned laser light beam. Upon completion of a 
last horizontal scanline of the tile T(1;1), the vertical raster generator 
150 is driven during a return interval to return to a position for 
projecting a first scanline of a subsequent tile in the same location on 
the screen. 
Referring now to FIG. 5, there is shown a schematic perspective view of a 
scaleable tiled flat-panel projection color display designated at 10, and 
comprised of a two-dimensional laser scanner array designated at 100, and 
a flat projection display screen designated at 200. For illustrative 
purposes only, the two-dimensional laser scanner array 100 is shown to 
comprise three laser scanner arrays 101, 102, and 103 arranged or stacked 
along a vertical axis (y) in an oriented relationship to one another. For 
illustrative purposes only, each laser scanner array is depicted as having 
four identical laser scanners disposed on a respectively common support 
181, 182, and 183 side by side along a horizontal x-direction. Each of the 
plurality of identical laser scanners arranged to form the two-dimensional 
laser scanner array is a laser scanner as described above with reference 
to FIGS. 3A, 3B, and 4. 
While only four laser scanners are shown for each of the three laser 
scanner arrays, it will be appreciated that the number of laser scanners 
per laser scanner array as well as the number of stacked laser scanner 
arrays, can be scaled in accordance with a scaled selected width dimension 
W and a selected height dimension H of the flat projection color display 
screen 200. 
For clarity of presentation, only the uppermost laser scanner array 101 is 
shown as having projected onto the display screen 200 a raster-scanned 
laser light beam so as to form a row of four seamlessly abutting tiles of 
horizontal scanlines SL. The middle laser scanner array 102 would project 
a second row of tiles onto the display screen, where the tiles of the 
second row would seamlessly abut the corresponding tiles of the first row. 
Similarly, the bottom or the lower laser scanner array 103 would project a 
third row of seamlessly abutting tiles, thereby substantially filling the 
display screen 200 with display tiles which abut along an x-direction as 
well as along a y-direction. 
Each of the laser scanner arrays 101, 102, and 103 has a respective laser 
diode array 110, 120, and 130 disposed in a corresponding common housing 
112, 122, and 132. Not shown here, each laser diode has, within the 
housing, a beam-shaping optical element as described with reference to 
FIG. 4. Each of the laser diodes 110, 120, and 130 emit respective laser 
light beams 113, 123, and 133 of a wavelength in a range of between 400 
and 430 nm. These laser beams are directed at respective horizontal 
scanline generators 115, 125, and 135 which produce periodically 
horizontally deflected laser beams forming the horizontal scanlines SL. 
These horizontal scanlines are received by respective concave beam 
reflectors 141, 142, and 143 and are reflected therefrom and directed at a 
reduced scanline length dimension onto a dedicated portion of a vertical 
raster generator which is common to all laser scanners of a laser scanner 
array. Thus, for example, each of the concave beam reflectors 141 projects 
a laser beam onto a portion of the vertical raster generator (a front 
surface mirror) 150 which is driven via a shaft 157 by a drive motor 155 
mounted to a bracket 156. Similarly, a bracket 166 carries a drive motor 
(not shown) to drive the vertical raster generator 160 of the laser 
scanner array 102, and a bracket 176 supports a drive motor (not shown) to 
drive the vertical raster generator 170 of the laser scanner array 103. 
Each of the drive motors receive appropriate signals from a controller 
(not shown) to oscillate the vertical raster generators in a synchronized 
manner through a raster scan interval followed by a return interval. 
As indicated above with reference to FIG. 4, a particular laser diode, its 
associated horizontal scanline generator, and a concave beam reflector are 
dedicated to project a particular tile onto the color display screen 200. 
For example, the laser diode 110-11, the horizontal scanline generator 
115-11, the concave beam reflector 141-11, and a dedicated portion of the 
vertical raster generator mirror 150 are dedicated to projecting a tile 
T(1;1) onto the screen. Similarly, a laser diode 130-43 of the laser 
scanner array 103 is associated with a horizontal scanline generator 
135-43, a concave beam reflector 143-43, and a dedicated portion of the 
vertical raster generator 170 to project a tile T(4;3) onto the display 
screen 200. 
For clarity of presentation, the two-dimensional laser scanner array 100 is 
depicted without enclosure. It will be appreciated that the 
two-dimensional laser scanner array 100 will be enclosed in a housing 
adapted to accept the flat color display screen 200 at an opening thereof, 
as schematically indicated in FIG. 1. 
The laser scanners of the two-dimensional laser scanner array 100, and the 
projection distance D between the display screen 200 and each of the 
vertical raster generators 150, 160, and 170, are operative and selected 
to provide seamlessly abutting display tiles on the color display screen. 
As previously described with reference to FIG. 1, each display tile area 
A.sub.t is preferably in a range of from 0.01 to 0.1 times the display 
screen area A. In FIG. 5, an effective display screen area A=H.times.W is 
substantially covered by 12 seamlessly abutting projected display tiles. 
Accordingly, each display tile has a file area of approximately 
0.083.times.A. 
Referring now to FIG. 6, there is depicted a plan view of a flat projection 
display screen designated at 200, and further detailing the raster-scan 
sequence of horizontal scanline projection onto the screen 200 to form a 
first row of abutting tiles, and the first two horizontal scanlines of a 
second row of tiles which abut the first row of tiles. When viewed in 
conjunction with the description of FIG. 5, a first laser scanner of the 
laser scanner array 101 projects onto the screen 200 at a position 
designated as SL START a first scanline traversing a first tile (1;1) from 
left to right in FIG. 6. Synchronized with the termination of the first 
scanline at the end of tile T(1;1), a second laser scanner of the laser 
scanner array 101 commences to project an abutting first scanline which 
sweeps from left to right across the tile T(2;1) associated with that 
particular laser scanner. A first scanline for tile T(3;1) and tile T(4;1) 
is similarly projected onto and swept across the screen by respective 
third and fourth laser scanners of the laser scanner array 101. When the 
first scanline reaches the end of tile T(4;1) at a location indicated as 
SL END, a second scanline from the first laser scanner in the laser 
scanner array 101 commences to sweep from the scanline start position 
horizontally across the screen within tile T(1;1), and the scanning 
process of the laser scanners comprising the laser scanner array 101 
continues through and including an i-th scanline being swept across the 
screen by the laser scanners dedicated to the respective tiles. 
Synchronized with the completion of the i-th scanline at the scanline end 
position SL END of tile T(4;1), a first laser scanner of laser scanner 
array 102 commences projecting a first scanline at the SL START position 
of the screen to begin the projection of a second row of tiles in the 
manner described above, and so forth. 
It will be appreciated that the area A.sub.t of the projected tile, given 
by the product of a height dimension h of the tile and a width dimension w 
of the tile, is influenced by the aforementioned considerations, and 
further by the power (intensity) of the laser light emitted by the laser 
diodes of the two-dimensional laser scanner array, and the minimum spacing 
between the parallel horizontal scanlines projected onto the screen (a 
measure of perceived resolution and perceived display quality). 
Referring now to FIGS. 7A, 7B, and 7C, there are shown schematic plan views 
of a flat display screen generally designated at 200, and having a width 
dimension W parallel to an x-direction and a height dimension H parallel 
with a y-direction. Projected tiles T are shown in dashed outline, having 
a width dimension w and a height dimension h. 
In FIG. 7A, a single laser scanner has projected a tile T(x;y) into the 
approximate center of the screen. Thus, the tile and the screen are not 
scaled with respect to each other. 
FIG. 7B shows one horizontal row of four seamlessly abutting tiles 
projected onto the screen by a laser scanner array having four laser 
scanners positioned side by side, such as, for example, the laser scanner 
array 101 of FIG. 5. The row of abutting tiles and the display screen 200 
are scaled with respect to each other along the x-direction. 
In FIG. 7C, there is depicted a display screen 200 having a desired width 
dimension W and a desired height dimension H projected onto the screen 
from a scaled two-dimensional laser scanner array are six seamlessly 
abutting rows of tiles, with each row corresponding to seven laser 
scanners positioned side by side. The dotted circular outlines shown 
schematically centered within some of these tiles schematically indicate 
the rows of tiles projected by respectively dedicated laser scanner arrays 
101 through 106 of a scaled two-dimensional laser scanner array 100. Thus, 
the two-dimensional laser scanner array and the display screen are scaled 
with respect to each other along the x-direction and along the 
y-direction. 
Each projected tile is contiguous and with other projected tiles on all 
sides. There are no physical seams between individual tiles since the 
display screen can be uniformly patterned with fluorescent elements using 
any suitable techniques such as photolithography, silk-screen printing, 
ink-jet printing, or any other reprographic processes. The butting between 
individual display tiles is done entirely by electronic and optical means, 
thus it is possible to construct a large projection display simply by 
scaling the display screen size with an appropriate number of identical 
laser scanners. 
Referring now to FIGS. 8A, 8B, and 8C, there are shown schematic 
perspective views of flat projection color display screens generally 
designated at 200 having patterned fluorescent red, green, and blue 
elements on a surface 220 of a light transmissive support 210. Fluorescent 
elements are also referred to in the art as fluorescent picture elements 
or as fluorescent pixels. 
The light transmissive support is preferably a glass support, or a plastic 
support such as, for example, a plastic sheet or foil support. 
The plurality of patterned fluorescent elements are disposed on the surface 
220 which is the surface upon which the laser light beam is projected from 
a laser scanner. Stated differently, these fluorescent elements are 
disposed on the surface 220 of the support 210 which is opposite a surface 
of the support from which the display screen is being viewed. 
In FIG. 8A, there is shown a plurality of fluorescent elements which have a 
repeating pattern along the width dimension W and along the height 
dimension H of the screen of adjacent or closely spaced red, green, and 
blue light emitting hexagons 226. 
FIG. 8B depicts a plurality of patterned fluorescent elements having a 
repeating pattern across the width dimension W and along the height 
dimension H of the screen of adjacent or abutting red, green, and blue 
light emitting squares 224. 
FIG. 8C shows a plurality of patterned fluorescent elements having a 
repeating pattern across the width dimension W of the screen of adjacent 
or closely spaced red, green, and blue light emitting stripes 222 
extending parallel to the height dimension of the screen. 
Each of the red, green, and blue (R, G, B) fluorescent elements or 
fluorescent pixels includes at least one fluorescent material to provide 
the respective emission of red light, green light, and blue light upon 
stimulation by the laser light beam from a laser scanner or a laser 
scanner array. For example, the red light emitting patterned elements 
include at least one red light emitting fluorescent material; the green 
light emitting patterned elements include at least one green light 
emitting fluorescent material; and the blue light emitting patterned 
elements include at least one blue light emitting fluorescent material. 
Fluorescent materials include organic fluorescent dyes, organic fluorescent 
pigments, dispersions of dyes and/or pigments in polymeric binder which 
can be a photopolymer, fluorescent polymers such as conjugated polymers, 
inorganic pigments, inorganic pigments dispersed in suitably selected 
polymeric binder, and mixtures of fluorescent materials. 
Each of the red, green, and blue patterned fluorescent elements further 
include at least one fluorescent compound capable of absorbing a laser 
light beam having a wavelength of from about 400 nm to about 430 nm, 
thereby causing the respective fluorescent elements to emit red, green, or 
blue light. 
One method of producing patterned fluorescent elements on a surface 220 of 
the display screen 200 is disclosed in U.S. Pat. No. 5,298,363, issued 
Mar. 29, 1994, entitled "Photolithographically Patterned Fluorescent 
Coating" which is commonly assigned and which is incorporated herein by 
reference. 
The invention has been described in detail, but it will be understood that 
variations and modifications can be effected within the spirit and scope 
of the invention. 
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TS LIST 
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10 tiled flat-panel projection display system 
100 two-dimensional laser scanner array 
101 laser scanner array 
102 laser scanner array 
103 laser scanner array 
110 laser diode array 
110-11 laser diode dedicated to a tile (1;1) 
111 beam-shaping optical element 
112 housing 
113 laser beam 
113-11 laser beam dedicated to a tile (1;1) 
113-41 laser beam dedicated to a tile (4;1) 
115 horizontal scanline generator 
115-11 horizontal scanline generator dedicated to a tile (1;1) 
115-41 horizontal scanline generator dedicated to a tile (4;1) 
120 laser diode array 
122 housing 
123 laser beam 
125 horizontal scanline generator 
125-42 horizontal scanline generator dedicated to a tile (4;2) 
130 laser diode array 
130-13 laser diode dedicated to a tile (1;3) 
130-23 laser diode dedicated to a tile (2;3) 
130-33 laser diode dedicated to a tile (3;3) 
130-43 laser diode dedicated to a tile (4;3) 
132 housing 
133 laser beam 
135 horizontal scanline generator 
135-33 horizontal scanline generator dedicated to a tile (3;3) 
135-43 horizontal scanline gcnerator dedicated to a tile (4;3) 
141 concave beam reflector 
141-11 concave beam reflector dedicated to a tile (1;1) 
141-41 concave beam reflector dedicated to a tile (4;1) 
142 concave beam reflector 
142-42 concave beam reflector dedicated to a tile (4;2) 
143 concave beam reflector 
143-43 concave beam reflector dedicated to a tile (4;3) 
150 vertical raster generator 
155 drive motor dedicated to vertical raster generator 150 
156 bracket 
157 drive shaft 
160 vertical raster generator 
166 bracket 
170 vertical raster generator 
176 bracket 
181 support 
182 support 
183 support 
200 projection display screen 
210 light transmissive support 
220 surface with fluorescent elements 
222 fluorescent R, G, B color stripes 
224 fluorescent R, G, B color squares 
226 fluorescent R, G, B color hexagons 
250 emitted R, G, B light 
A display screen area = H .times. W 
A.sub.t display tile area = h .times. w 
D projection distance between vertical raster generators and 
projection display screen 
h height dimension of a file T 
H height dimension of display screen 
R, G, B red, green, blue fluorescent elements 
SL scanlines 
T tile(s) projected onto the projection display screen 
w width dimension of a file T 
W width dimension of display screen 
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