Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
10~0~65
This invention relates generally to apparatus ror
electrostatographic reproduction of images and more particularly
to apparatus providing an image storage device during an inter-
mediate reproduction processing step. The intermediate storage
device can act as a buffer device, transforming an image having
a ormat unacceptable for efficient electrostatographic
reproduction into an image having an acceptable format. A
plurality of image storage devices can provide precollation
of a plurality of images into a predetermined sequence.
It is frequently convenient to connect an image into a
signal encoded format, such as in a suitable binary signal
encoding in order for the storage or the transmission of
the image. The encoding of the image can be in a line-by-line
or raster scanning format, or in a format providing a more compact
or convenient signal representation. In order to reconstruct
the signal encoded image, the encoded signals are used to
activate a display device and the resulting display can be
focused on an appropriate photosensitive surf~ce for subse~uent
development. For example~ in the FR-80 Computer Printer
System, available from Information International Inc., having
o~fices in Los Angles, California, an image in the form of bir.ary
encoded signals, activatès a cathode ray tube display deviae.
The image of the cathode ray tube face is focused on a film .
medium. The film is subsequently developed providing a copy
of the displayed image. A particularly important feature of
this system is the use of the film medium to accumulate displayed
portions of the image, the composite of the displayed portions
providing the entire image. Tnis feature permits tne signal
encoded data to activate the display device without a restruct-
uring of the data in a line-by-line scan synchronized with
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exposure of the storage medium and/or without additional
apparatus providing a storage of the image for continual
display on the cathode ray tube. In the absence of the image
storage medium, multiple image reproductions can be obtained
by repeated display of the image on the oscilloscope or by
separate multiple reproductions of the developed film.
It can be desirable to replace the film medium
with a plain paper medium and utilize the convenient techniques
of electrostatographic reproduction. However, it is desirable
that the apparatus accomplishing this change not require the
photoreceptor to be immobilized during the focusing of the image
to be reproduced. In addition, the use of apparatus for image
reformatting or for image signal storage is undesirable. Further-
more, the interaction between the apparatus providin~ the image
encoded signals should be automatic and the opportunity for
multiple reproduction should be provided.
By one aspect of the present invention, there is
provided an improved system for electrostatographic reproduction
of a selected sequence of images of the type having a display
device responsive to image encoded signals, an intermediate
image storage device for storing an image produced by the
display means and an electrostatographic device for reproducing
images applied by the image storage device wherein a plurality
of image storage devices, each of which image storage devices
controllably apply an image stored therein to the electrostato-
graphic device and control means being provided for applying
images stored in the plurality of image storage devices to the
electrostatographic device in a selected sequence.
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~ y a furtllor aspc~t: of the presellt i.JlVell~iOn .1
system is provided for producing electrostatographically copies
of a selected sequence of images. The system comprises means
for storing signals identifying images of the selected sequence,
means for providing a plurality of groups of signals associated
by the stored signals, each of the signal groups comprised of
an image encoded in signals. Means are provided responsive to
the signal groups for displaying the signal encoded images
with means responsive to the display means for storing the
display means images. A plurality of means responsive to the
display means images is provided for storing the display means
images, the storage means including means for displaying irnages
stored therein. Means are provided responsive to the displayed
image of an addressed one of the storage means for providing
at least one electrostatic reproduction of the displayed
storage means image. Control means is provided responsive to
the signal storage for storing identified images in the
plurality of storage means, the control m~ans including means
for determining the addressed one storage means and for
sequentially applying the stored identified image to the
electrostatographic reproduction means.
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More broadly, these aspects may be accomplished
according to the present invention, by providing an image
storage device, which can accumulate component portions of
an image as the portions are exhib-i~ed by a dis~lay-device
and which can apply the stored image to the photosensitive
medium of an electrostatographic reproduction device. Control
apparatus is provided for automatically synchronizing the
image storage device with both the display device and the
electrostatographic reproduction device.
A plurality of image storage devices can be provided
for storage of more than one image. Control apparatus can
select the particular image to be reproduced thereby providing
a preselected sequence of images. ~ddition apparatus retains
the stored image until notification of satisfactory completion
of the electrostatographic reproduction process for the stored
mage .
The image storage apparatus can be a liquid crystal
device. The control apparatus, in response to signals from
the display apparatus, erases images remaining on the liquid
crystal devices and sensiti~zes the storage device to images
provided by the display device. Upon storage of the complete
image by the liquid crystal storage device, the stored image
is focused on the photosensitive element of the electrostato-
graphic reproduction machine. The image can remain focused
for the reproduction of a plurality of image copies before
preparation o-f the storage device for a succeeding image.
These and other features of the in~ention will be
understood upon reading of the following description along
with the drawing wherein:
Fig. 1 is a block diagram of the apparatus for
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providing electrostatographic reproduction of signal encoded
images according to the preferred embodiment.
l . Fig. 2 is a schematic diagram of a liquid crystal
image storage device utilized in th~ preferred embodiment.
Fig. 3 is a Y~Ltage ~ r~m indicating the ~oltage
utilized in tke operation of the liquid crystal image storage
device.
Fig. 4a and Fig. 4b together comprise a schematic
diagram of the control apparatus providing automatic control
of the liquid crystal image storage device according to the
preferred embodiment.
, .
Fig. 4c is a voltage diagram indicating the operation
of the timing devices utilized in the automatic control apparatus.
Fig. 5 is a schematic block diagram providing for
a variable time period for multipie image reproduction.
Fig. 6a and Fig. 6b show schematically two arrangements
~ ..... .. . .
for providing a plurality of image storage deYices for utiliza-
tion as an optical buffer memory.
Fig. 7 shows flow diagram of the op~ration for
electrostatographic reproduction of a given seguence of images.
Fig. 8 shows a schematic block diagram for apparatus
controlling electrostatographic reproduction of a given
sequence of images.
- Fig~ 9 shows a schematic block diagram of additional
apparatus to retain an image stored in an image storage device
in the event of unsatisfactory electrostatographic reproduction.
F~g. lO is a schematic diagram of apparatus for
sensing satisfactory completion of an electrostatographic
reproduction.
Referring now to Figure 1, the block diagram of the
apparatus for providing electrostatographic reproduction of
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an image encoded in an electric~l signal format is shown.
Apparatus 11 provides the signals which represent the image.
Signal apparatus 11 can, for example, be a
data processing machlne in which the image encoded signals
are stored in a memory unit or apparatus fox ~eceiving trans-
mitted image encoded signals- The image encoded signals of
~ignal apparatus are applied to display device 12, in the
preferred embodiment display device 12 is a cathode ray tube,
and the applied signals activate the display device output
image. The output image of display device 12 is focused
by means of optical system 13 onto image storage and display
device 10. Optical system 13 can be a lens system or a fiber
~optics system or can be eliminated if display device 12 is
sufficiently close to image de~ice 10.
The activation of the display de~ice 12 by signal
apparatus 11 is communicated to control apparatus 20. Control
apparatus 20, having previously prepared image device 10 for
receipt of an image, i.e., by erasure of a previously stored
image, can sensitize the image device 10 to the image
- 'focused thereon.
After completion of the image storage, the storage
of the image by image device 10 is communicated from signal
apparatus 11 to control apparatus 20. Control apparatus 20
signals the control unit 24 of an electrostatographic reproducing
machine 15 to provide a reproduction of the image stored in image
device 10. The control apparatus 20 activates the display portion
of device 10 thereby providing a display of the stored image.
In the preferred embodiment, image de~ice 10 is positioned
near the document platen 26 of the machine 15. The displayed
~mage is focused by means of optical system 14 onto a photo-
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receptor 16 of machine 15. The optical system 14 can include
optical elements as well as mechanical apparatus ror determining
the position of the image stored in storage device 10 on
photoreceptor 16. A drum-type or belt-type photoreceptor
can be utilized to receive the displayed image. The photo-
receptor 16 is initially charged by the corona discharge device
27. The portion of pnotoreceptor 16 receiving the displayed
image is developed at developer station 17 and transfèrred and
fused to copy sheets 23 at transfer station 18. Copy `
sheets ~3 are supplied by paper source 21 transported along
feed path l9 by appropriate means and deposited in finished
copy sheet tray 22. The apparatus for implementing the
development, transfer and fusing of the electrostatic image
produced by the displayed image on the photoreceptor are
known to those skilled in the art of electrostatographic
reproduction. --
Referring next to Fig. 2, the image storage and
display device 10 according to the preferred embodiment is
shown. The image deYice l0 is comprised of transparent conducting
windows 31 and 32. Transparent insulating material has a
thin conducting layer applied on an interior surface of the window,
the conducting layers on the surfaces forming a cavity.
Deposited on conducting window 31 is a photoconducting material
34. A liquid crystal material 36 is located between photo-
~onducting material 34 and window 32. An insulating material
33 provides structural support for the windows 31 and 32 and
provides an enclosure for the li~uid crystal material 36.
Windows 31 and 32 are coupled respectively to conducting
leads 38 and 39. A source of illumination 35 is also provided.
The operation of the image de~ice 10 can be under- '
stood as follows. The liquid crystal, utilized in the preferred
embodiment contains two components. One component produces a
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current induced scattering of applied radiation. The second
component provides a material which impedes the current
induced optical scattering mechar.ism from rela~ing and dis-
appearing. When a voltage is applied between windows 31 and
32, i.e. Via electrical couplings 38 and 39, the insulating
properties of photoconductor 34 in lhe absence of applied
radiation, prevent current from flowing in the liquid crystal.
~owever, when radiation is applied on a local region of the
photoconductor, the insulating property is altered and the
photoconductor becomes conducting in the region of applied
radiation. Voltage applied between windows 31 and 32 is now
appliea between photoconducting material 34 and window 32 across
the liquid crystal 36, causin~ a current to flow and optical
scattering to be produced in the liquid crystal. When the spacing
between window 32 and photoconducting material is sufficiently small,
the flow of current will be confined to a localized region.
Upon removal of the ~oltage between conducting leads 38 and 39,
the local optical scattering will remain. When the image
aevice 10 is now illuminated with a generalized or flooding
radiation, the optical scattering centers will scatter the
applied radiation while in the region of insignificant optical
scattering the flood illumination will be transmitted without
appreciable scattering. Thus, as will be clear to
those skilled in the art by proper positioning of
flood illumination and aperature stops, an image
determined by the illumination in the presence of applied
voltage can be produced. Thus the image device 10 provides
the mechanism for storing an optical Lmage along with the
ability to display that image.
Reerring now to Flgure 3, the potential voltage
applied to conducting leads 38 and 39 of the liquid crystal
--10--
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cell 37 during a typical operation cycle is shown. During
a period D1, in the presence of flood illumination, a gradually
increasing ~oltage 41 is applied. This period provided a
uniform optical scattering of the entire liquid crystal cPll
37 so that after erasure of the scattering, an~ ~esidual
scattering will be uniform over the entire cell. During
period D2 a negative voltage 42 is gradually applied to the cell
39 in the presence of flood illumination. The use of re~erse
curxent can, for some liquid crystal materials prolong the "
useful lifetime. However, some materials do not require the
application of a nagative voltage and for the material a pause
with no applied voltage can be utilized during D2. During D3,
an oscillating voltage of gradually increasing magnitude in a
preselected frequency range is applied to conducting leads 38
and 39. The result of this oscillating voltage application
is the removal of a majority of the optical scattering centers
in the li~uid crystals. During period D4, a gradually increasing
voltage 45 is applied between conducting leads 38 and 39, in
the absence of flood illumination. During this time interval,
the cell 37 is exposed to and stores the optical image to be
reproduced. The time period D5 provides a wait period including
the absence of applied voltage 45 and flood illumination.
During period D6, a substantially null voltage 46 is applied
to conducting leads 38 and 39. During this period, the flood
illumination or other illumination source can provide a display
of stored image. As will be seen from Fig. 3, care should be
taken to prevent abrupt changes in the voltage applied to
the liquid crystal material to prevent undersirable effects
from occurring.
Referring next to Figure 4a, the ~ontrol apparatus
--11--
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20 for control of the image device 10 and for providing an
interface between signal apparatus 11 and the electrostatographic
reproducing machine 15 is shown. In Figure 4a and Figure 4b, a
plurality of timer devices labelled Dl (111), D~ (12B), D3 (132),
D4 (121) and D5 (136) are shown. These devices have the general
characteristic shown in Fig. 4c. An input voltage applied to the
timer device results in an output voltage which is delayed by
a predetermined time interval D from the application of the
input ~oltage. However, removal of the input ~oltage to
t~mer devices re~ults in a substantially or only slightly
delayed removal of the output voltage.
Initiation apparatus 60 pxovides a method of initiating
an operational cycle for the image device 10. One input ter-
minal of logic "OR" gate 101 is coupled to termlnal 105, a
second input terminal of "OR" gate 101 is coupled through --
manual switch 106 to a common potential and a third input
terminal of "OR" gate 101 is coupled through resistor 102
to the common potential and through capacitor 103 to voltage
source ~1 Voltage source Vl is also coupled a first solenoid
te~minal of relay 107. A second solenoid terminal is coupled
-- to an output terminal of "OR" gate iOl. A fixed terminal c o~
relay 107 is coupled to power source Ll, and fixed terminal
b of relay 107 is not electrically coupled. In the description
of the relays, terminal a can be controllably coupled to either
terminal b or to terminal c while terminal d can be controllably
coupled to either terminal e or to terminal f, the particular
coupling of the controllable terminal determined by the
activation of the relay solenoid.
Controllable terminal a of xelay 107 is coupled to
controllable terminal d of relay 108, a irst solenoid terminal
i -12-
lO~
o~ relay 108 and to a first terminal of switch 109. A second
solenoid terminal of relay 108 is coupled to p~wer source L2.
A second terminal of switch 109, is coupled to a
first solenoid terminal of relay 110, to ~ controllable terminal
d o relay 110, to a first input terminal of timer 111, and
to controllable terminal d of relay 112. Fixed terminal b
of relay 108 and fixed terminal e of relay 108 are.not electric-
ally coupled. Fixed terminal f of relay 108 is coupled to
fixed terminal e of relay 113. Fixed terminal c of relay
10% is coupled to an anode of diode 123. Controllable terminal
a of relay 108 is coupled to fixed terminal f of relay 114, to
a first terminal of timer 121 and to an anode of diode 122.
A second solenoid terminal of relay 110 is coupled
~o power source L2. F~xed terminal e of relay 110 is not
electrically coupled, while fixed terminal b of relay 110 - -
is coupled through resistor 116 to the common potential. Fixed
terminal f of relay 110 is coupled to fixed terminal e of relay
114. Fixed terminal c of relay 110 is coupled to a fixed
terminal c of relay 119 to a cathode terminal of diode 123 and to
one terminal of resistor 120. COntrollable terminal a of relay
110 is coupled to fixed terminal b of relay 112 and to fixed
terminal c of relay 115.
_ . .
.. A second input terminal of timer 111 has power source
L2 applied thereto, while the output terminals of timer 111
are applied to the solenoid terminals of relay 112. Control-
lable terminal a of relay 112 is coupled through capacitor
.
- 126 to the common potential and to fixed terminal b of xelay
115. Fixed terminal c of reiay 112 is coupled to controllable
terminal a of relay 113. Fixed terminal e of relay 112 is
coupled to a first solenoid terminal of relay 127, while a
second solenoid terminal of relay.127 is coupled to power
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source L2. Fixed terminal b o~ relay 127 is no~ electrically
coupled, while fixed terminal c and controllable terminal a of
i relay 127 are coupled to flood lamp circuits. Fixed terminal
f of re~Ay 112 is coupled to a fixst input terminal of timer
128.
A second input ter.minal of timer 128 is coupled to
power source L2 while the output terminals of tLmer 128 are
~oupled to input terminals of a solenoid of relay 113. Con-
trollable terminal d of relay 113 is coupled to power source
Ll. Fixed terminal b of relay 113 is coupled through resistor
129 to a controllable terminal of resistance diYiding network
130~ Fixed terminals of resistance dividins network 130 are
coupled to potential source V2 and the common potential.
~ixed terminal c of rélay 113 is coupled through resistor 131
to the common potential. Fixed terminal f is coupled to a
firs~ input terminal of timer 132 and to a controllable
terminal a of relay 114.
A second input terminal of timer 132 is coupled to
power source L2~ while output terminals of timer 132 are coupled
to terminals of a solenoid of relay 114. Controllable terminal
d of relay 11~ is coupled to controllable terminal d of relay
115, to fixed terminal b of relay 133 and to controllable
- terminal a of relay 117. Fixed terminal b of relay 114 is
coupled through switch 135 to power source Ll, and to a
first terminal o~ a solenoid of relay 134. Fixed tenminal
c of relay 114 is coupled to fixed terminal b of relay 117.
~ second input terminal of timer 121 is couplPd to
power source Lz, while output terminals of timer 121 are
coupled to terminals of a solenoid of relay 115. Controllable ter-
minal a of relay 115 is coupled to fixed terminal b or relay il9 and
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through capacitor 144 to the common potential. Fixed terminal
e of relay 115 is not electrically coupled while fixed terminal
f of relay 115 is coupled to a anode terminal of diode 124.
A cathode terminal of diode 124 is coupled to a cathode
terminal of diode 125.
Controllable terminal a of rela~ 133 is coupled to
power source Ll, while fixed terminal c of relay 133 is not
coupled. Solenoid terminals of relay 133 are coupled to
output terminals of timer 136. A first input terminal of
timer 136 is coupled to power source L2, while a second input
terminal of timer 136 is coupled to an anode terminal of diode
125 and to a fixed terminal c of relay 117.
Fixed terminal e of relay 117 is not coupled electrically
while fixed terminal f of xelay 117 is coupled to terminal D.
Controllable terminal d of relay 117 is coupled to terminal C.
A first terminal of a solenoid of relay 117 is coupled to
power source L2 while a second terminal of the solenoid of
relay 117 is coupled to a first terminal of a solenoid of
relay 118 and to a cathode terminal of diode 125.
A second terminal of the solenoid of relay 118 is
coupled to power source L2. Controllable terminal d of relay
118 is coupled through capacitor 137 to the ground potential.
Fixed terminal e of relay 118 is coupled through resister 138
to potential source Vl. Fixed terminal f of relay 118 is
coupled through resister 139 to the common potential and to
a set terminal S of an R - S bistable network 140. Controllable
terminal a of relay 118 is coupled to terminal A while fixed
terminal c xelay 118 is coupled to terminal B. Fixed terminal
b of relay 11~ is not electrically coupled.
Controllable terminal a of relay 119 is coupled to
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fixed terminal b of relay 134. A cathode terminal of diode
122 is coupled to a first terminal of a solenoid of relay 119
and to a cathode terminal of diode 141. A second solenoid
terminal of relay 119 is coupled to power source L2. An
anode terminal of diode 141 is coupled through switch 142
to power source Ll. A second terminal of xesistor 120 is
coupled to a controllable terminal of resistance dividing
network 143 while fixed terminals of resistance dividing net-
work 143 are coup~ed potential source ~2 and to the ground
potential respectively.
A second solenoid terminal of relay 134 is coupled
to power source L2. Controllable terminal a of relay 134 is
coupled through image device 10 to the common potenti~l and
through resistor 145 and lamp 146 coupled in series to the
ground potential. Fixed terminal c of relay 134 is coupled
through the output winding of transformer 147 to the common
potential~ Controllable terminal d of relay 134 is coupled
to the common potential. Fixed terminal e of relay 134 is
coupled through resistor 156 to~potentiai source Vl and to
an input terminal of inverting ampli~ier 157. An output
terminal of inverting amplifier 157 is coupled through resistor
159 to a common potential and through capacitor 158 to terminal
R of R - S bistable network 140. Fixed terminal f of relay 134
is coupled to a irst terminal of reslstor 153 and to a first
terminal of resistor 152. A second terminal of resistor 153 is
coupled to a controllable terminal of a resistance dividing
network 154 while fixed terminals of the resistance dividing
network 154 are coupIed to the common potential and to voltage
source V3. A second terminal of resistor 152 is ~oupled
through capacitor 151 to the co~mon potential, to the cathode
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terminals of twin triode 148, and to a center-tap terminal o
an output winding of transformer 150. Terminals of the out-
put winding of transformer 150 are coupled to the grid electrodes
of twin triode 148. ~ first grid electrode of triode 148 is
coupled through resistor 155 to the common potential. Input winding
terminals of transformer 150.are coupled to oscillator 149. Input
winding of transformer 147 are coupled to plate electrodes
of twin triode 148 while a tapped terminal of the input winding
of transformer 147 is coupled to potential source V3.
The operation of the control apparatus 20 can he
described as follows. Pulse generating apparatus 60 causes
activation of the solenoid associated with relay 107 when
one of input termin~ls of "OR" 101 assumes a potential
sufficiently close to a common potential. The pulse can
be generated manually by switch 106, by a signal applied to --
terminal 105 from, for example, the signal apparatus 11, or
upon turning on the apparatus wherein capacitor 103 is
gradually charged through resistor 102. The activation of the
solenoia of relay 107 causes the power source Ll to be applied
through relay 107 to a solenoid terminal of relay 108. When
power sources Ll and L2 are simultaneously applied to the
solenoid terminals, the positions of the controllable terminals
are changed. Thus power source Ll is maintained to relay 108 through
terminal d and 1 of unactivated relay 113 and terminal d and f
of relay 10~, even upon inactivation of the solenoid of relay 107.
Upon closing of switch 109, the solenoid o relay
110 is activated and a volt~gè input is now applied to timer
111. However, for a period of time Dl, the solenoid of relay
112 remains inacti~ated. During time Dl, the potential applied
to the controllable terminal of resistance diYiding network 143
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is applied through relay 110, th~ough rela~ , th~ough relay
115, through relay 119, *hrough relay 134 and applied to image
device 10. Therefore, with the assistance of capacitors 126
and l44, curve 41 of Figure 3 can be produced. During the period
o time Dl, power source Ll is applied to the solenoid of relay
127, activating the flood lamp circuits.
Ater time Dl, the solenoid of relay 112 is activated,
and power source Ll applied to timer 128, and the potential
of the controllable terminal of resistance dividing networ~
130 is applied through (as yet unactivated) relay 113 through
relay 112, through relay 115, through relay 119~ through
relay 134 and applied to the image device lOi the capacitors
126 and.144 eliminating an abrupt ~oltage change.~ Thus the
Yoltage of segment.42 ~f Fig. 2 is appliea to the image storage
and ~isplay device~ - In the preferred embodiment, the flood ~
lamp remains activated by a timing circuit (not shown) associated
with the flood lamp circuit.
Ater a period D2, the solenoid of relay 113 is
actiYated. Power source Ll is removed from the solenoid of
relay 108, thereby inactivating relay 108. Power source
Ll is applied to timer 132 and the solenoid of relay 134.
Oscillator circuit 65 includes an oscillator 1~9 driving a
twi~ triode eléctron tube. The output of the electron tube . -
is usea to apply the oscillation voltage to image device 10
through relay 134. Relay 134 changes the cathode potential of
the triodes of electron tube 148 rendering the tube nonconductive.
~owever, as capactor 151 discharges, the electron tube will
become increasing conductive producing waveform 43 of Fig. 3.
The relay 134 also removes the short circuit ~xom input terminal
of amplifier 157. However the differentiating circuit formed
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by resistor 159 and capacitor 158 prohibit activation of
bistable network 140, the bistable network activated only by
a positi~e going pulse.
After time D3, tLmer 132 acti~ates the solenoid
relay 114, thereby inactivating rela~ 110. The inactivation
o relay 110 causes timer 111 and timer 128 to inactivate
relay 112 and relay 113 respectively. The inactivation of
relay 113 removes the power source from timer 132, however,
timer 132 continues to ~e coupled to power source Ll via
relay 114, r~lay 117 and relay 133. Relay 134 is also inactivated
and the input of amplifier 157 is grounded causing the R - S
bistable network 140 to be reset. The Q terminal of network
140 produces a sigral indicating that the image de~ice 10
is ready to store an optical image. The activation of
relay 114 applies power source Ll to timer D4 ~ia relay 133
and the solenoid of relay 119 is activated causing voltage
from network 143 to be applied to the image device 10 via
relay 119 and relay 134~
Upon completion of an image display, the signal
appaxatus 11 sends an "advance" signal to terminal 105 of control
apparatus 20n Relay 108 is activated as before and power
source Ll applied through relay 113 maintains the activation
of relay 108. Relay 108 activates the solenoids of relay
117 and relay 118. Acti~ation of relay 117 and 118 causes
a shorting of terminals A and B and of C and D which in turn
causes the activation of the electrost~tographic reproduction
machine 15. Acti~ation of relay 118 also removes ~he signal
~rom the Q terminal of bistable network 140. In the absen~e
o~ a signal applied to terminal 105, the passage o internal
D4 will produce the same activation of relay 117 and relay
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5.'~
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108 as produced by relay 107.
'After inter~al D4, timer 136 has a potential applied
thereto. Timer 136 provide a pause ~nd a~ter an inter~al
D5, relay 117 and relay 118 are inc~ctiYated and by ~emoval
of power from timer 32, ti,mer 121 and timer B6, relay 114,
relay 115 and relay 133 are all respecti~ely inac~iva~ed.
The next sequence of control apparatus 20 will begin upon
actiYation of switch 109.
Referring now to Fig. 5, the preferred embodiment
of switch 109, when multiple copies of the signal encoded
image are desired. In this event, a vari,able time D5 will
be necessary to expose the photoreceptor 16 from the image
device 10. Switch 109 is comprised of a relay 171, a logic
'~AND" gate 172 and a logic KNOR" gate 173~ The controllable
terminal a and the fixea terminal c are the terminals of switch
109 in the control apparatus 20. A solenoid of relay 171
has a first terminal coupled to potential Vl and second
~erminal coup~ed to an output terminal of "NAND" gate
172. A first input terminal of the "NAND" gate is'coupled
to a terminal of the electrostatic'rep~oduction machine
indicating, with a positive logic signal, that the exposure
of the image device 10 has been completed. A sec,ond inpu~
terminal is coupled to signal apparatus 11 indicating with
- a positive logic signal that the sequence of reproductions of the
- signal encoded emage is not co~plete. A third input terminal of
nNAND" gate is,coupled to an output terminal of "NOR" gate'
- 173. The input terminals of ~NO~" gate 173 are coupled to
appara*us which senses t~e output signals of timers 132, 121
- and 136 respecti~ely. When the vutput signals of'all the
timers are null signals, a positiYe signal will be present
"~ 20-
~o~o~
at the third input terminal of "NAND" gate.l72. A fourth
terminal is coupled to apparatus associated with relay 110 and
when Felay 110 is inactivated, a positive signal is applied to the
fourth terminal of "NAND" gate 172. When all the input signal~
of "NAND" gate 172 are positive slgnals, the output terminal
of NAND gate will be a null signal and the solenoid and there-
fore the relay of 171 will be activated.
~ h cont~ol apparatus 20 therefore provides for
automatic interface between the apparatus producing the signal
encoded images, the image apparatus.and the electrostatographic
- reproduction apparatus. The signal apparatus 11, in the
preferred embodiment, produces a signal when an image ready to
.
be displayed on display device 12, but produces the display.
only upon proper receipt of the signal. The electrostatographic
reproducing a~paratus begins the appropriate sequencing upon
receipt of the signals from the control apparatus of storage
of an image in display device 10. The cycle is repeated
upon determination that the electrostatographic reproduction
machine has completed the operation, for example, an appropriate
number of copies has been produced.
. Referring ne~t to Figure 6a and Figure 6b, a schematic .
Yiew of the use of a plurality of image storage de~ic~s lOa
through.lOm as an optical buffer is shown; In Fig. 6a the
position control apparatus 79 associated wlth optical system 78
dete`rmines which of the image storage devices is to be addressed.
The position control apparatus also controls the electrical
coupling of the aontrol apparatus 20 to the optically addressed
image device. Mixror 77 along with the associated position
control device determines whether the addressed image storage
device is optically coupled the photoreceptor 16 or to display
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90~s
device 12. In Fig. 6b, a second em~odiment of an optical
buffer utilizing a multiplicity m of image storage devices is
~hown. In this embodiment, the imaqe stoxage devices are
positioned on a wheel 80, the orient:ation of the wheel
determined by a position control device 79. Each image
storage device can then be brought into position to apply a
stored image through optical system 14 to a photoreceptor
ass:ociated with the electrostatic storage device and into
position to receiYe an image for storage.from display device
12 through optical system 13.. The electrical signals are
applied to the appropriate image storage de~ice from control
apparatus 20, ~ia commutator 31. . - - .
The operation.of an optical buffer according to the pre-
ferred embodiment can be understood by reference to the flow ch~rt
of Figure 7 and the schematic block diagram of Figure 8. A number
m of devices are available for storage of opti~al images. A series
of image identification signals are stored in task memory 301 along
wi~h task data, such as number of copies to be produced by the
el~c rostatographic reproductio~ machine. After a BEGIN operation
201, consisting of power on, then COUNT = O, operation resetting
counter 308, the CLEAR IMAGE DEVICE MEMORY operation and the
n=l operation 202 produced by a STROBE 1 signal are performed. ~j
The STROBE 1 signal causes the first entry in task memory 301
to be.placed in task register 303 and the first entry in image
device~memory 302 to be entered in the image device register 304.
The STROBE 1 signal also latches the contents of these regis- .
ter~. Operation 203 is the determination of whether the image
dèvice:in the operational position has an image already stGred
therein. A ST~OBE 2 signal actuates logic apparatus 311 which
in the event of a non-zero signal in register 304 the register
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associate~ with the image storage device in the operational
position, stores a signal in ~iynal storage network 312. A
STROBE 3 signal thereafter initiates operation 204 through logic
circuit 313, the operation of the electro$tatographic reproduction
machine an~, via gates 314, applies signals to the reproduction
machine defining the task. Although shown as a following event on
the flow ~iagram, simultaneously the availability of a new
task, operation 205, is eXecuted. In the pre~erred embodiment,
STROBE 2 signal activates logic apparatus 305, incrementing
COUNTER 308 when no task is available in task register 303
.
and storing a signal, ~ia in~erting amplifier 306, in signal
storage network 307 when a new task is available. When the
count in counter 3 n 8 is equal to m ~ 1, one more than the
number of image storage devices, the operatio~ of the electro-
statographic reproduction machine is halted,- there being no --
image to be reproduced in the m image storage devlces.
Thg signal of storage ne~work 307 is utilized to enter
image indentification signals in a data processing machine forapplication to tne corresponding element of the optical
buffer memory of the image enco~ed signals associated
with the image of the image identification signals. A STROBE
4 signal activates logic 317 and places a signal in signal
storage network 331. An output of signal storage network 331
produces an erase and a store operation, operation 208 and-
20g, respective~y, for the addressed image storage device.
A STROBE 5 signal actuates logic gate 332 which produces a
signal causing the next image device in sequence to be addressed
by the position control apparatus ~operation 211). The STROBE 4
signal transfers the signals of the task register 303 to be
transferred to the last image deYice memory l~cation which is
now vacantO Delay device 310 produces signal dela~ed for the
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10~ i5
STR~BE 5 signal which resets counter 308, operation 210 and
which resets the storage networks. With the application of
another STROBE 1 signal, the cycle is repeated, i.e., the
operation 212, n = n + 1 (mod m) is preformed and register
304 contains data related to image storage de~ice now in the
operat~onal position.
It will be clear to those skilled in the art that
the STROBE signals used to illustrate the operation of the
preferred emkodiment are more complex than timing signals. These
s~g~als can be initiated, for example, only upon completion
....
of some prior operation. This feature prohibits activation
of a further step before completion of a preceeding operation.
. .
It will be clear to those skilled in the art that if
additional image devices are available, then the erase operation
and the new image storage operation can be performed simultaneously
with the reproduction of the image. Thus a saving o~ time can be
accomplished but at the expense of additional equipment.
Referring once again to Figure 7, operation 207,
is a verification that the image reproduction is complete.
It can be operationally inefficient to erase a stored image
and have to retrieve it at a later time. Therefore, as shown
. ~ . . .
in Figure 10, a radiation source 341 is reflected from a copy
~heet 23 on the feed path 19 prior to storage in copy bin 22.
Sensor 342 measuxes the reflected optical radiation at a time
when the copy sheet is in position as determined by copy
sheet sensor 343. The presence of an unacceptable reproduction
sheet at the position determined by copy sheet sensor provides
a signal at the output of logic gate 3~g. This logic gate
can be further enabled by a signal indicating the machine
.
cycle is still acti~e. The presence of a positi~e signal
.: .. . - ,
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at the gate output of gate 349 or pxovided.by unsatisfactory
operation, for example, a lamp that did not flash, will
proYide a error signal at the output of OR gate 351.
Referring now to the Figure 9, additional storage
registers 321, 322 and 323 have been added, associated with a
wait position 321, as erase position 322, and a store imaye
position 323 to implement operation 207. ~he signals in
register 304 are transerred to register 321. Dete~tion of
~nacceptable operation will be entered i~ the register after
the.next STROBE 1 signal a signal in a predetermined register
cell position. When the signal is already set indicating a
se~ond malfunction, an abort operation is activated, halting
operation. In the absence of a second flag signalO the next
STROBE 1 signal shifts t~e data from register 321 to register 322.
The ~mage device is now in a position for erasure, however,
the flag activates a signal inhibiting erasure. ~nother
S~ROBE 1 signal transfers the contents of register 322 to
register 323, the position for image storage in the image
device. The presence of the signal inhibits the storage
operation. Similarly the presence of the slgnal in 323, causes
t~e contants of register 323 to ~e entered in memory 302 and
the contents of register 303, normally entered, are prevented
~rom the transfer though gates 318 (Figure 8). Finally, the presence
of a signal in register 323 is utilized to prevent transer of
~emory contents from task memory 301 to task register 303.
The result is that in the event of an unsatisfactory reproduction
cycle, the reproduction will be repeated, e~en though out of
order, without recall of the signal encoded data. It will
be clear that, when sufficient time is available, iOe. all
operations are performed a one image de~ice address,.there is
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no need for additional registers. In this situation, the
succeeding STROBE 1 signal will be activated only upon satis- !
factory completion of the reproducti.on cycle. ,
. The above description is included to illustrate the
operation of the preferred embodiment and is not meant to
limit the scope of the in~ention. The scope of the invention
1~ limited only by the following claLms. From the aboue dis-
cussion, many ~ariations will be apparent.to one skilled in the
art that would yet be encompassed by the.spirit and scope of
the invention7 .. -. - .
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