Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF INVE~TION
The subject invention relates to an apparatus and
method whereby any image which can be converted to differen-
tiable components which, in turn, can be converted to
electrical signals may be copied or recorded; specifically
hard copied on film, plastic, paper, etc. Although not in-
tending to be limited thereby, the present concepts are
discussed herein for providing color hard copies utilizing
fiber optic cathoderay tubes including light emitting
phosphors disposed thereon. In this regard, the prior re-
cording systems and methods for providing images on sensitized
surfaces are characterized in that fractional portions of a
random scanned image or figure to be displayed are displayed
on a display window of a display apparatus, then adding to
the input signal applied to the display device to provide the
figure a sending signal whose voltage changes periodically
at a constant rate for sequentially displaying and moving the
remaining portion of the figure in one direction at a
constant speed across the window, and having a r-cording media
provided in front of the diaplay window moved in synchronism
with the movement of the figure in the display window thereby
recording the figure on the recording medium. Such prior
art is not, however, capable of producing images on the
sensitized surface by describing images differentiable from
otherwise identical images in terms of hue, lightness and
saturation because the figure displayed on the display device
is not defined as a function of hue.brightness, and saturation.
Another known facsimile method and apparatus is the
system described in U.S. Patent 3,811,007 to Unger et al.
In such system, a hard copy of a refeshed computer terminal
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cathode-ray tube display is produced in light sensitive paper
by scanning the moving paper in the direction of paper movement
employing a cathode-ray tube. This system is not, however,
capable of producing images in color or producing images
utilizing electrographic techniques.
Other types of systems, say, to provide an image
on or for the production of color film from a color signal are
also well known. For example, in U.S. Patent 3,685,899 a
special form of field sequential video color is recorded on
standard black and white film as a black and white se~aration
master at either 50 or 60 fields/second using a continuous
film motion electronic beam recorder; a standard color film
is then made from the separation master by exposing each frame
of the color film in sequence to red, green and blue
separation images using appropriate color filters with the
separation masters. This system is, however, field
sequential color as are the systems described in U.S. Patents
3716664, 2600868, 2878309 and 3006260. Field sequential
color,is, of course, wherein each field represents a single
color component of the color signal and wherein the fields
are sequential so that the recording may be done in real
time on a black and white separation master. Thus, special
lens systems or color wheel means or three gun continuous
film motion recorders must ~e utilized. As such, the
si~e of and cost of the system increases accordingly.
SUMMARY OF THE INVENTION
In accordance with one aspect of the invention there
is provided an apparatus for producing images on a
sensitized surface, comprising: a cathode ray tube having
33 a faceplate with a plurality of phosphorescent materials
deposited thereon; means for generating a preselected
component of a portion of an image within a first of said
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phosphorescent materials and a different preselected
component of said image within a second of said materials;
means for exposing a sensitized surface to said image
portions generated within said phosphorescent materials;
and means for causing mutually synchronous movement of
said image portions and said sensitized surface across
said faceplate in a direction traversing each of said
phosphorescent materials so as to sequentially expose said
surface to each component of said image portions.
In accordance with another aspect of the invention
there is provided a method of producing an image on a
sensitized surface comprising the steps of: providing a
cathode ray tube having a faceplate with a plurality of
phosphorescent materials deposited thereon, each of said
materials being selected to produce upon excitation
radiant energy having a wavelength different from that
produced by the other of said materials; generating a
preselected component of a portion of an image within a
first one of said phosphorescent materials and a different
preselected component of said image within a second one of
said materials; exposing a sensitized surface to said
image portions generated within said phosphorescent
materials; and causing mutually synchronous movement of
said image portions and said sensitized surface across
said faceplate in a direction traversing each of said
phosphorescent materials so as to sequentially expose said
surface to each component of said image portions.
The present invention overcomes the above-identified
and other ancillary disadvantages of the prior art and
provides a preferre~ embodiment of an apparatus and method
whereby any image that can be converted to simple color
components of red, green and blue and converted to
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electrical signal or images starting as electrical signals
can be copied. As the apparatus accepts red, green and blue
signals which can be utilzied to produce a gray scale image,
it is compatible with monochrome systems. Additionally, the
apparatus and method can be easily extended to copy refreshed,
random deflection and stored displays or images. The
simplicity of the system, the term "system" hereinafter to
refer to the apparatus and method, is that it requires only
one cathode-ray tube with a single electron gun structure
and a three phosphor area deposited on the faceplate thereof.
(The terms refreshed, random and stored are conventional
terms to indicate continuously rewritten, written onde and
retained and in memory, respectively.)
Basically, the system uses a fiber optic cathode-ray
tube whose faceplate has three strips of color phosphorescent
material. In addition, circuitry is used to switch the color
components of the image to be copied at a correct instant of
time. In operation, a gain generator starts simultaneously with
the CRT deflection sweep and a blue gate enables the component
blue to Z axis modulate the CRT. During this time, ~he CRT
beam is being swept up and into the area of blue phospho-
rescent material. After the CRT beam has progressed across
one-third of the phosphored area, the blue gate is disabled
and a green gate enabled. Green phosphorescent material is
likewise swept followed by red. As the beam is being swept
up the phosphored area, a sensitized surface such as film,
paper, plastic, etc., is moving vertically in synchronization
with the sweep; thus, such surface is exposed. By synchronizing
the image scroll rate and the surface rate, the surface is
exposed repeatedly thereby improving the effective sensitivity of
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the surface. Additionally, by connecting, electronically
or physically, all color component inputs to the system
together, the system is compatable with monochrome systems.
Alternatively, any image separated into its primary color
components may also be copied on monochrome sensitive surfaces
with no additional system changes if the sensitive surface
utilized has a wideband sensitivity, i.e., see published
spectral characteristic curves for various types of sensitized
surfaces.
It is therefore an object of the present invention
to provide an apparatus and method of producing images on a
sensitized surface to overcome the disadvantages of the prior
art.
It is another object of the present invention to
provide an apparatus and method of producing images on a
sensitized surface by describing the images on the sensitized
surface in terms of hue, lightness and saturation.
It is yet another object of the present invention
to provide an apparatus and method of producing images on a
sensitized surface by describing the images on the sensitized
surface in terms of lightness.
It is still yet another object of the present
invention to provide a system for producing images on a
sensitized surface by energy traveling as wave motion
propagated by periodic variations radiated from phosphorescent
su~stances.
It is a further objec of the present invention
to provide a system for producing images on a sensitized surface
by energy traveling as wave motion propagated by periodic
variations radiated from phosphorescent substances deposited
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on the faceplate of a fiber optic cathode-ray tube.
It is a still further object of the present
invention to provide a system for producing color hard copies
on sensitized surfaces of a raster scanned image.
It is a yet further object of the present invention
to provide a system for producing color hard copies on sensi-
tized surfaces of a random scanned image.
It is a yet still further object of the present
invention to provide a system for producing color hard copies
on sensitized surfaces of a stored image.
A further object of the present invention to provide
a system for producing color hard copies on sensitized surfaces
of any image represented by an electrical signal using a
single electron gun cathode-ray tube.
The foregoing and numerous other objects, advantages,
and inherent functions of the present invention will become
apparent as the same is more fully understood from the
following description and drawings which describe the invention
in its preferred embodirnent; it is to be understood, however,
that the embodiment i5 not intending to be exhausting nor
limiting of the invention but is given for the purpose of
illustration in order that others skilled in the art may fully
understand the invention and principles thereof and the
manner of applying it in practical use so that they may
modify it in various forms, each as may be best suited to the
conditions of the particular use.
DESCRIPTION OF DRAWINGS
In the drawings, wherein like numerals refers to
like elements:
Figure 1, including figures lA, lB and lC, are the
side, top, and front views respectively, of the cathode-ray
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tube utilized in the present invention;
Figure 2 is a time related drawing of electrical
signals representing primary color components to explain
gradation of color;
Figure 3 is a diagram of the preferred system
according to the present invention;
Figure 4 is a graph of time related waveforms to
explain operation of the system in accordance with Figure 3; and
Figure 5 is a timing diagrm showing the relationship
of the electrical signals and sensitized surface in accordance
with the present invention.
DETAILED DESCRIPTION OF INVENTION
Referring now to the drawings and in particular to
Figures lA-lC, there are shown side, top and front views
respectively, of the CRT utilized in the preferred embodiment
of the present invention. It can be seen that the numeral
10 generally indicates and refers to an evacuated CRT envel-
ope enclosing therein a writing gun comprising a cathode 12,
control grid 14 and a focusing/accelerating anode structure 16
for forming a narrow writing beam of high velocity electrons,
modulated by a Z-axis electrical signal, emitted from the
cathode which are caused to strike light emitting surfaces
such as phosphorescent material 18 disposed on the inner
surface of a faceplate 20. The writing beam is deflected by
applying deflection signals to a deflection yoke 22, which
yoke being slideably received and selectively rotatable
and positionable about the envelope 10 to provide a means to
control the CRT electron beam and for further obvious reasons.
As an alternative to a deflection yoke 22, the CRT
electron writing, beam may be controlled or deflected by
applying deflection signals to a pair of horizontal deflection
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plates and a pair of vertical deflection plates provided
within the envelope 10 and spaced between the focusing/accel-
erating anode structure 16 and the phosphorescent material
18 in a conventional manner. For further information and a
detailed description of such preferred or alternative
deflection means, those interested are referred to a series
of books copyrighted by Tektronix, Inc., the assignee of the
subject invention, entitled Circuit Concepts. Although not
shown in the drawings, conventional CRT operation voltage
generating electronics are provided for supplying such
voltages to the CRT.
In accordance with the present invention, the
phosphorescent material 18 has been deposited on a surface
23 of the faceplate 20 utilizing conventional techniques.
For the preferred embodiment, faceplate 20 is a fiber optic
faceplate and phosphorescent material 18 defines a plurality
of n adjacent strips of phosphor selected from that group
of phosphors or groups of phosphors whose radiant energy
distribution of light output is within the range that the
human eye responds to light wave length (typically from about
400 to 650 nanometers, see previously mentioned books) as
defined on any standard chromaticity chart. For the embodiment
shown, the phosphor strip 24 corresponds to phosphors for
providing red light, strip 26 for providing green light
and s~rip 28 for providing blue light. Such phosphor strips
may be, for example, commercially available RCA primary colors
designated 22R, 22G and 22B. It should be emphasized that
the order in which the strips are deposited or the order
of adjacency of the strips is strictly a matter of choice.
Additionally, it is not necessary to limit the radiant
energy distribution of light output from the phosphors or
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group of phosphors to be within the range that the human eye
responds to light wave length; for example, the phosphorescent
material could be an ultraviolet or infrared emitter to produce
on the sensitized surface a visible image.
Before proceeding with the description of the
invention, atten~ion should be directed to the time related
waveforms shown in Figure 2. These waveforms will be used to
describe how, using three primary color phosphors, it is
possible to provide gradation of color, i.e., hue. As seen
in the drawings, waveform 35 illustrates a red waveform
corresponding to, say, the red portion of an image converted
to an electrical signal whereas waveforms 37 and 39 are
electrical signals representing the image in terms of green
and blue, respectively. In this figure assume that as
shown, only two levels exist between which the signal can
alternate and only when at its highest level that energy
traveling as wave motion propagated by periodic variations
is radiated from a corresponding phosphor strip as discussed
previously. Therefore, the waveforms 35, 37 and 39 added
together, electrically, provides the composite image which,
in turn, represents the energy traveling as wave motion to
produce on a sensitized surface the hue of the image copied.
Thus, the produced image 41 would consist of a plurality of
hues defining, left to right, white, yellow, cyan, green,
magenta, red, blue and black, i.e., adding one unit each of
red, green and blue produces one unit of white, red plus
green produces yellow, and so on through black. It should be
noted that the primary colors, red, green and blue as well
as complementary colors yellow, cyan and magenta are given in
the example for purposes of illustration only and that any
real color can be considered an additive mixture of spectrum
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color which lies within the focus of real colors as defined
by the International Commission on Illumination (I.C.I.) on a
chromaticity diagram. Additionally, saturation (or the
sensation of saturation) corresponds to the purity of a
color and is defined as the distance of its representative
point from a reference white point on the chromaticity
diagram expressed as a percentage of the distance from the
reference white point to the extremities of the sprectrum
focus. Although not shown in Figure 2, it can be assumed
that the saturation or purity of the primary colors and
complementary colors are 100~ because each primary waveform
corresponds to unity when high. Thus, to have a green
primary which is 50% saturated, for example, would be to
have the waveform 37 of one-half amplitude. The third
characteristic of the energy radiated from the phosphorescent
material is brightness, brightness is, of course, defined
as the total amount of light energy perceived by the eye as
being dim to very bright. This characteristic, conventionally
called luminous flux, is dependent on several variable
factors such as the type of phosphorescent material utilized.
The luminous flux of varius phosphorescent materials are provided
in the previouslymentioned hooks and will not be described
further in this description.
The above-described process of combining the primary
colors to provide a chrominance display of an image obtained
from electrical signals representation of the image is
most generally found in the field of television as a means
and method of displaying an image in color on the screen of
a cathode-ray tube such as a television monitor or display
device. ~In a television application the addition of the
primary signals does not necessarily follow the one unit to
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one unit transformation as explained, but is most generally
transformed into a brightness component Y (luminance) equalling
59% green + 30~ Red + 11% blue, and in phase signal I equalling
-28% green + 60% red - 32% blue, and a quadrature signal Q
equalling -52% green + 31% red + 41% blue.) However, the
utilization of the phosphor strips 24, 26 and 28 enables
the display device to utilize only a single electron gun as
opposed to a plurality of electron guns as is generally the
case in the field of television. Additionally, there are a
few types of cathode-ray tubes utilized in the field of
television wherein only single electron gun structures are
utilized. However, such CRT's have many phosphor areas and
each area comprising the three separate phosphors rather
than a single phosphor area comprising the three separate
phosphors.
Continuing with the description of the preferred
embodiment of the apparatus for producing images on sensitized
surface according to the present invention, reference should
now be made to Figure 3 wherein is shown the system to be
hereinafter described. It is seen that the CRT 10 is responsive
to a Z-axis electrical signal applied thereto via an amplifier
50, such Z-axis electrical signal modulating the CRT electron
beam under the control of a pair of electrical si~nals
applied to yoke 22 via means 52,54. Again , as explained
in the description regarding Figure 1, conventional CRT
operational voltage generating electronics in accordance
with proper CRT operation must be provided so that such
voltages are supplied to the CRT. The first of the pair
of electrical signals used to control the CRT electron beam
modulated by the Z-axis signal is obtained from means 52
which defines a combined sweep generator and processing
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lQ9772~
amplifier and such signal is therefore a sawtooth (ramp,
linear, etc.) current waveform to displace the beam of the
CRT over the entire surface of the faceplate in the vertical
direction which is defined as the direction of arrow 56,
whereas the second of the first pair of electrical signals is
obtained from means 54 to displace the beam of the CRT over
the entire surface of the faceplate in the horizontal direction
which is defined as the direction of arrow 58. This latter
signal is also a sawtooth current waveform, but as opposed
to the first, is provided at a much faster rate by means 54;
means 54 also being a combined sweep generator and processing
amplifier. Means 52 and 54 might be, for example, a triggered
Miller integrator whose output is applied to a conventional
two-stage complimentary current amplifier operating within
the limits of the particular CRT to displace the beam over
the entire surface of the faceplate. Although not shown in
the drawing, such means are preferably operational amplifiers
utilizing feedback obtained from sensing the current flowing
through the yoke 22 in a conventional manner. Amplifier 50,
whose output signal is the Z-axis' electrical signal, can
be for example, a conventional quasi-differential feedback
amplifier dr.iving a cascode amplifier to control the voltage
between, say, the cathode and control grid of the CRT to thereby
control the intensity of the CRT electron ~eam.
Means 5 as well as another means 60 for generating
a sawtooth (ramp, linear, etc.) voltage waveform, the purpose
of which will become apparent shortly, are gated (triggered)
from a means 62 such as a synchronizer, which, in turn, o~erates
or is operated in direct synchronism with an image generator
or display means 64 capable of providing the image to be
copied on the sensitized surface as an electrical signal.
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Responsive to the sawtooth voltage waveform
generated by me~ns 60 and a second sawtooth waveform is a means
66 such as a comparator, such comparator comparing the pair
of sawtooth voltage waveforms to generate a gate which
is used to trigger or to cause the second of the pair of
electrical signals to be generated. This second sawtooth
voltage waveform is provided by yet another means 6~
triggered from an image copying control means 70 such as a
copy switch. The second sawtooth voltage waveform is also
applied, or alternatively an electrical signal derived by
the means 68, to and operatively associated with a sensitized
surface driver means 69 for providing synchronous movement
of the surface therewith. Means 69 could be, for example,
a controllable drive means such as a motor for advancing
the sensitized surface adjacent the faceplate of the CRT
[~l the directio~ of arrows 116), such sensitized surface stored
in a cartridge under the control of the motor. As mechanisms
for moving i.e., driving sensitized surfaces are well known
no further discussion is believed necessary and those desirious
of such information are referred to a Tektronix Instruction
Manual, Part No. 070-1686-01 relating to such devices.
Coupled to receive the z-axis electrical signal
from amplifier 50 and to pass such signal to the Z-axis of
the CRT is a means 72 such as a switch. Switch 72, which
can ~e any conventional electronic analog switch, is
operated under control of the comparison of the pair of
sawtooth voltage waveforms to present the Z-axis signal to
the CRT only during selected intervals in accordance with
the comparison.
Considering operation of the system thus far
described, in Figure 4 there is shown a plurality of time
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related waveforms generated by the system when a simple image,
say, of a typical raster scanned, random scanned or stored
display is to be copied. For example, it is desired to copy
on a sensitized surface a raster scanned image which has been
converted to be represented by an electrical signal such as
shown at 74A. The waveform 74 might comprise a synchronization
portion and picture portion indicated 76 and 78 respectively.
Thus, the waveform 74 would be generated or taken from
display means 64 and provided to synchronizer 62 as well as
10 amplifier S0 as indicated by dashed line 80. Synchronizer
62, in turn, generated trigger or gate pulses to drive means
52 and 60. If, for example, waveform 74 was an electrical
signal representative of an image to be copied in a television
manner, synchronization portion 56 would represent a line
synchronization pulse which reoccurs about every 64 microseconds
(63.6 microseconds for conventional I~TSC television);
although not shown, a second synchronization portion for field
synchronization also occurs after every 256.5 live lines.
Thus, means 60 coupled to be triggered by portion 76 would
20 generate the waveform 80. Similarly, means 52 would generate
a current sawtooth responsive to the field synchronization
portion to sweep the beam of the CRT in the direction of
arrow 56.
In response to the activation of means 70, means
68 is triggered and the waveform 82 is generated. Waveform
~2, a much slower waveform than the waveform 80, is (1)
compared by means 66 with waveform 80 for producing the
waveform 84, and (2) is utilized to synchronize a conven-
tional mechanism for driving or moving the sensitized surface
30 on which the image is to be copied. Wavefonn 84, in turn,
is used to trigger or gate means 54 thereby producing the
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current sawtooth waveform 86 to displace the beam of the
CRT over the surface of the faceplate in the direction
indicated by arrow 58.
Simultaneously with the triggering of means 54 by
waveform 84 to generate waveform 86, means 72, under control
of waveform 84 is enabled thereby as indicated by the gating
waveform 88. Consequently, only that portion of the waveform
74 reoccuring simultaneously with the gating waveform 88 i~
applied to the Z-axis of the CRT. In the example given, the
portion would be the waveform 90A. As can be discerned, as
the image is scrolled across the faceplate of the CRT and
the sensitized surface scrolls adjacent the faceplate, the
image will be produced on the surface as synchronous movement
of the energy and surface occurs.
In accordance with the present invention, however,
as the image is scrolled across the faceplate of the CRT
and the sensitized surface scrolls adjacent the faceplate,
synchronously, the image or images to be copied are provided
as energy representative of differentiable characteristics
of the image to be produced. The image or images produced
are therefore differentiable from otherwise identical images
because the images will be produced in terms of hue, lightness
and saturation enabling color hard copies to ~e produced.
This is accomplished quite economically and efficiently by
the addition of a plurality of means 92, 94 and 96, such as
electronic switches disposed between means 64 and amplifier
50 as shown in Figure 3. Each switch receives from the image
generating or display means 64 components corresponding to
either the red~ blue and green primary color components
of the image to be produced such as the waveforms 74B and
74C and the previously discussed waveform 74A which now
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would represent a primary component of the image rather thanthe composite thereof as in prior art, and a corresponding
gating or timing waveform generated by a means 98 such as a
gate generator under the control of the already mentioned
comparison signal or waveform 84. These gating or timing
waveforms produced are shown at 100, 102 and 104 and are
timed in accordance with the order in which the already
mentioned phosphorescent strips are deposited on the CRT.
In the embodiment shown in Figure 3, with phosphor strips
as discussed for Figure 1, waveform 100 and the red signal
component would be applied to means 92 which define a red
component switch, waveform 102 and the green signal
component to means 94 which defines a green component switch
and waveform 104 as well as the blue signal component to means
96 which defines a blue component switch; means 98 can
therefore be thought of as a means to generate sampling
signals and the switching means as a means combining the
primary color components and the sampling signals to
provide an electrical signal. From the drawing of Figure 4
it can also be seen that only during the ramp time of waveform
86 will these gating signals be produced and only during these
sample times will a particular component of the image be
gated and applied as an electrical signal representative of
differentiable characteristics of the image to the Z-axis
of the CRT, i.e., each image is the combination of m displaced
partial images (spatial and time). Alternatively, by
combining the outputs of means 64 or outputs each of the
means 92, 94 and-96 as indicated by 106, the system may be
made compatible to monochrome as such combining means could
conventionally reconstruct the electrical signals into a
single signal which corresponds to a conventional signal
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applied to amplifier 50 via dashed line 80. Means 98 in thepreferred embodiment is for example, a one shot multivibrator
in integrated or discrete form and means 92, 94 and 96 are
integrated or discrete component selectors of an input
analog signal responsive to a digital input. As these means
are well known, no description is believed necessary.
Referring now to Figure 5, there is again shown
the plurality of electrical signals 35, 37 and 39 which
represent, say, the primary color components of an image
displayed on a display device 110 such as a television
monitor or display device. These electrical signals
produce on device 110 a plurality of color bars; such bars
are, from top to bottom, white, yellow, cyan, green, magenta,
red, blue and black and will be described to detail operation
of the system according to the present invention. Again, as
the color bars and monitors are well known to those in the
art, no further discussion is believed necessary. In accor-
dance with the invention, signals 35, 37 and 39 are also
applied to the inputs of means 92, 94 and 96 (reference should
also be made to Figures 3 and 4). At a sample time, say To,
gate generator 98 is triggered by waveform 84. In response
to the trigger at time To, generator g8 produces the timing
signals (or gates) 100, 102, and 104. In turn, the signal 86
is generated to deflect the beam of the CRT in accordance
therewith. During the duration of waveform ~6, between
time To and Tl, when signal 100 (red gate) is present, only
phosphor 24 of faceplate 20 produces energy, i.e., produces
red light as indicated by shaded areas 114. Simultaneously
therewith, the sensitized surface is moving adjacent the entire
faceplate in the direction of arrow 116. At the time Tl, signal
100 is removed thereby pre~enting any red signal (if any)
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from energizing the phosphor 24 and green gate signal 102enables green phosphor 26 to be energized between times Tl
and T2. The sensitized paper, having been selectively exposed
to red light becomes selectively exposed to green light in those
shaded areas indicated 118. At the end of time T2, signal
102 is removed and signal 104 gates the blue video signal and
phosphor 28 is energized as indicated by shaded areas 120.
As the sensitized surface passes through the areas 120, it is
again exposed, this time ~o blue light.
It can clearly be understood then, that the time the
sensitized paper is moved through a distance defined by
window 112, it has been exposed repeatedly to provide a copy
or reproduce the image which is desired. It should be restated
at this time, that the window 112 is scanned at a very fast
rate as compared to the rate of surface movement thereby
enabling the phosphor area to appear as being constantly ene~
gized and that for use in typical television systems, gate
signals are generated at the line rate, i.e., 525 gates for
each color would be generated every one-thirtieth of a
second for a standard 525 line NTSC System. Additionally,
the rate of paper movement and the apparent rate of window
movement are the same.
Thus, there has been described a system of producing
images on a sensitized surface whereby the surface is
repeatedly exposed and as such effectively improves the
sensitivity of the sensitized surface material, a system
whereby images produced are compatible for both chroma and
monochrome principles, a system which is economical and has
various other ancillatory advantages over the prior art.
While there has been shown and described the
preferred embodiments of the present invention, it will be
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apparent to those skilled in the art that many changes and
modifications may be made without departing therefrom in its
broader aspects. For example, it is within the rea~lm of the
invention that the CRT be replaced by a plurality of properly
aligned light and lens means, light emitting diodes, energy
transferring devices such as conductor ends or other electro-
graphic techinques, and light emitting devices such as lasers
for producing the colored light, etc. Also, it is within the
realmof the invention that the CRT be replaced by a CRT
for displaying a viewing image, that the light energy be
transferred~to the sensitized surface via a conventional lens
or mirror system or that a two surface transfer median
system be utilized. Therefore, the appended claims are
intended to cover all such changes and modifications as fall
within the time spirit and scope of this invention.
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