Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~2670~4
MICROFILM READER-PRINTER
BACKGROUND OP THE INVENTION
This invention relates to microfilm reader-
printers and, more particularly, to reader-printers
that produce paper copies of images using a light
sensitive media that is developed by heat.
With the increasing amount of information
that must be stored and readily available to business~
es, government and the general public, microfilm has
become a very common and important storage media.
Microfilm enables large quantities of documents, data,
or graphics to be stored in relatively small spaces.
Microfilm can be stored in several configurations.
One form is commonly referred to as microfilm jackets,
in which individual strips of film are placed between
two transparent plastic sheets having channels to
accept and retain tbe film. A second form similar to
microfilm jackets is microfiche in which a piece of
material approximately 4 inches by 6 inches has the
information disposed ther~on. Microfiche can also be
made by a duplicating process from an original micro-
film jacket. The size of the microfiche can vary,
however, the concept encompasses placing multiple
images on a single card or fiche. Another form has a
card with a rectangular cut therein holding an indivi-
dual piece of film, commonly referred to as an aperture
card. The images may also be retained on rolls of
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microfilm which are stored in cartridges or cassettes
for later retrieval.
There are basically two types of microfilm
readers used to project the images onto a screen for
viewing by an observer. The first type, commonly
referred to as the "rear projection" type, uses a
translucent screen which has the image projected on
the read surface of it for viewing by the observer.
The second type, commonly known as the "front projec-
tion" type, projects the microfilm image onto a screenwhich is viewed by the observer from the same side on
which the i~age is projected. The observer thereby
sees the image via reflected light rather than trans-
mitted light as in the rear projection type. Although
the present invention is designed for use with micro-
film jackets, microfiche, or aperture cards, it could
~e adapted for use with roll microfilm which is stored
in cartridges or cassettes.
Oftentimes the user desires to have a per-
manent record on paper of an image which he has beenviewing. The apparatus to view and to provide the
copy is commonly known as a reader-printer. There
are two common methods by which the paper copy is
created. The first uses the electro-photographic
process in which a uniformly charged photo-conductive
sheet of paper is exposed to the image. The charge
on the surface is dissipated depending upon the pre-
sence or absence of light This produces a charge
distribution on the surface which coincides with the
image. The exposed charged surface is then placed in
contact with toner particles which are attracted to
the charged surface depending upon the magnitude of
the charge remaining on the sheet. The toner particles
are then fixed to the charged surface and a paper
copy is produced.
In the second process a light sensitive
imaging surface, commonly a dry silver material, is
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kept in a light-tight enclosure until it is to be
used. The dry silver sheet is then exposed to the
image. The exposed sheet is transported to a develop-
ing station where it is subjected to heat which de-
velops the latent image. The paper copy i5 produced
without the need of separately charging and toning
the sheet such as is required in the electro photo-
graphic process. As can be readily appreciated the
dry silver process requires less sophisticated equip-
ment than is required`in the photo-conductive process.
Charging, toning and fusing stations are not required.
- The only requirement is that the dry silver paper be
kept in a light-tight enclosure until it is exposed
and then subjected to a uniform heating device for
developing.
The present invention relates to a newly
designed reader-printer which, because of its unique
design, provides an extremely economical and efficient
front projection reader-printer for use with the dry
silver copying process.
SUMMARY OF THE INVENTION
The present invention is a new and improved
reader-printer that is extremely simple in its design
and operation resulting in a reader-printer which is
more economical to manufacture than any previous unit.
The device a~cording to the present invention provides
a reader-printer which is simple and easy to operate~
has a minimum number of operator adjustments and is
extremely compact when compared to other reader-prin-
ters. In the viewing mode, the image is projectedonto a viewing screen or easel which is viewed by the
user. When a print of the image is desired, the opera-
tor moves a switch on the front of the reader from a
viewing mode to the print mode. In the print mode,
the image continues to be projected onto the viewing
screen. The operator then pushes a print button which
initiates the print cycle. A timing motor is activated
~67~)24
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which operates a cam and linkage arrangement to close
a pair of cafe doors in the front of the reade~-prin-
ter. ~his seals off ambient light from the viewing
screen. The projection lamp is momentarily deenergi~ed
while a sheet of light sensitive dry silver paper is
fed and positioned onto the viewing screen. The pro-
jection lamp is momentarily energized to project the
image onto the light sensitive dry silver paper. The
lamp is again momentarily deenergized while the dry
silver paper with a latent image thereon is fed to a
developing station. The paper passes around a roller
which is adjacent a heating shoe and the image is
- developed by heat. The paper is then ejected to a
receiving tray. The cafe doors reopen and the projec-
tion lamp is again energi~ed projecting the image
onto the viewing screen.
The timing se~uence and opera~ion of the
printing steps is accomplished by means of a timer
motor and controller. Separate motors are used for
feeding paper from a cassette to paper feed rollers
which move the paper onto the viewing screen. A separ-
ate developer motor rotates the developing roller to
transport the paper through the developer.
Accordingly the invention seeks
to provide a front projection microfilm reader-printer
which utilizes a simplified system for producing paper
copies of the images. Further, the invention seeks to provide
a microfilm reader-printer having a minimum number of
operat,or adjustments to further simplify making paper
copies and which utilizes light
sensitive dry siIver paper to
produce copies of the micro~ilm images. An advantage
of using dry silver paper is that it simplifies the
apparatus ~or the imaging and development processes.
Various aspects of the invention are claimed
and in one aspect the invention pertains to a control
circuit for apparatus for reading or printing images
from a microimage record comprising a control switch
for selecting a view mode or a print mode, a print switch
for initiating a copy print se~uence and a first circuit
energized by operation of the control switch to the view
mode for projecting a viewable image of the microimage
record. A second circuit is energized by operation of
the control switch to the print mode and operation of
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the print switch for carrying out a copy print sequence.
Sequence timer means in the second circuit is energized by
operation of the print switch for controlling a timer cycle
including copy feed, exposure and developer operations and a
circuit branch is connected between the first and second
circuits for maintaining operation of the sequence timer means
during a timer cycle in response to operation of the control
switch from the print mode to the view mode prior to completion
of the timer cycle.
A further aspect of the invention comprehends a
microimage reader-printer comprising a housing, a viewing
screen disposed at a fixed location within the housing, means
for projecting images onto the viewing screen, the housing
having viewing means for permitting a viewer to view the
viewing screen and the viewing means having means for
controlling the passage of light therethrough. Means are
provided for holding a supply of light sensitive sheets, and
there is means for transporting the light sensitive sheets
individually from the supply holding means onto the surface of
the fixed viewing screen for exposure by the projecting means
and to transporting the sheets to a developing station.
Control means is responsive to a print signal for sequentially
rendering the projecting means operative to disable the lamp
means, operating the transporting means to transport one of the
sheets from the holding means onto the fixed viewing screen,
rendering the projecting means operative to enable the lamp
means to project an image onto the sheet present on the fixed
viewing screen to expose the sheet, rendering the projecting
means operative to disable the lamp means, operating the
transporting means to transport the sheet to the developing
station for development, and rendering the projecting means
operative to enable the lamp means to project an image onto the
vlewlng screen.
Other aspects of the invention will become more
apparent from the detailed description herein.
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BRIEF DESCRIPTION OF THE DRAWING
_
Other objects and advantages of the invention
will become apparent upon consideration of the follow-
ing detailed description and reference to the drawing,
in which:
FIG. 1 is a perspective view of the microfilm
reader-printer with the outer housing o~ the reader-
printer removed for clarity;
FIG. 2 is a front elevational view of tha
reader-printer shown in FIG. l;
FIG. 3 is a right side view of the reader-
- printer;
FIG. 4 is a cross-sectional view taken along
line 4-4 of FIG. 2 with portions removed for clarity;
FIG. 5 is a schematic diagram of the control
circuit oE the reader-printer of FIG. l; and
FIG. 6 is a diagrammatic illustration of
the sequence timer and timing sequence chart for the
control circuit of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
Turning first to FIG. 1 there is illustrated
a microfilm reader-printer 10 illustrating the present
invention. The outer housing has been removed to
expose a portion of the internal operating mechanism.
The reader-printer 10 has a frame 12 and a base portion
14 having fiche carriage 16 mounted thereon. The
fiche carriage 16 receives the fiche (not illustrated)
which has the individual images thereon. The carriage
16 can move in the horizontal plane to position any
of the desired images for viewing.
As seen in FIG. 4, the base portion 14 en-
closes a projection lamp 18, a first mirror 20 and a
condenser lens 22. A pair of glass flats 24 receives
the fiche and is positioned above the condenser lens
22. The beam of light from the lamp 18 is reflected
upward through the fiche and the image from the fiche
is projected through an objective lens 26 to a second
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mirror 28 mounted to the frame 12. The image is then
reflected onto a viewing screen or easel 30 within
the reader-printer 10. The viewing screen 30 is placed
at an appropriate angle so that the user can easily
observe the image projected on the screen 30 through
an opening or window 32 in the frame 12 at the front
of the reader-printer 10. A ~ocusing knob 33 is con-
nected to and controls a focusing mechanism that moves
the objective lens 26. This E~rojection system is
common to front projection microfilm readers.
As seen in FIGS. 1, 3 and 4 there is a paper
tray 3g adapted to receive a light-tight cassette 35
containing dry silver photographic imaging paper. To
provide acceptable copies, the dry silver paper must
not be exposed to stray ambient light before or during
the printing cycle.
To seal off ~he ambient light from passing
through the window 32 there are a pair of cafe doors
36 which close during the printing process. The door
2~ closing mechanism is best illustrated in FIGS. 1 and
3. During the print cycle a timing motor 38 causes a
cam 40 to rotate in the direction of arrow A (the
clockwise direction as seen in FIG. 3). A spring 42
which is in tension has one end mounted to the frame
12 and the other end mounted to a first link 44. As
the cam 40 rotates, a follower 4S on the first link
44 follows the cam profile. The spring 42 causes the
fi~st link 44 to pivot about pivot point 47 as the
follower 46 follows the abrupt drop-off 4~ on cam 40.
30 Thus, the end of the link 44 closest to the cam 40
drops downward raising an opposite end 50 of the link
44.
A connecting pin 52 at the end 50 is con-
nected to a connecting link 54. As the end 50 is
raised, the connecting link 54 rotates in the direction
of arrow B. The end of the connecting link 54 opposite
the connecting pin 52 is connected to a rotatable
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control shaft 56. Rigidly mounted to the control
shaft 56 are a pair of door control levers 58 which
pivot in holes in the cafe door assembly 36. When
the shaft 56 is rotated clockwise the doors 36 will
be urged to an open position. When the shaft 56 is
rotated counterclockwise the door 36 will be uryed to
a closed position.
Tbe path followed by the dry silver paper
through the reader-printer 10 is best illustrated in
lQ FIG. 4. The light-tight cassette 35 holding the dry
silver paper is placed on the Ipaper tray 34. A spring
- 62 forces the paper up against a pair of cassette
feed rollers 64 that are mounted to a shaft S6. The
cassette has two holes or slots (not illus~rated)
that are in alignment with the cassette feed rollers
64. One end of the shaft 66 is connected to a cassette
feed roller motor 68 (FIG. 2). The cassette feed
rollers 64 are mounted to the shaft 66. The shaft 66
is connected to a clutch assembly that causes the
feed roller 64 to drive the top sheet of paper in the
paper feed direction when the motor is energized, yet
allow the cassette feed roller 64 to freely rotate
when the feed motor 68 is deenergized.
At the beginning of the print cycle, the
cassette feed motor 68 momentarily drives the feed
rollers 64 causing the top sheet of paper to be fed
into a nip defined between a first feed roller 70 and
an idler roller 72. The first feed roller 70 is con-
nected by means of a belt and pulley arrangement to a
second feed roller 74. The belt connection can be
seen in FIG. 1 wherein a pair of pulleys 76 and 78
are connected by means of a belt 80 such that when
the paper transport motor 82 is connected to and rota-
tively drives the pulley 78, the pulley 76 is also
driven. The pulley 76 is fastened to the same shaft
on which the first feed roller 70 is mounted. Simi-
o~
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larly, the pulley 78 is fastened to the same shaftthat has the second feed roller 74 mounted on it.
As the sheet is fed past the first feed
roller 70 and the idler roller 72, a paper guide 82
urges the paper around the first feed roller and onto
the easel or viewing screen 30. A pair of ~-configured
edge guides 84 located on either side of the viewing
screen 30 guide the paper so that it is properly
aligned as it is fed up onto the viewing screen 30.
There is a second idler roller 86 which forms a nip
with the second feed roller 74 to continue feeding
the paper up along the viewing screen 30. When the
paper is in its proper image reproduction location,
it trips a paper registration sensor arm 86 that ex-
tends through an opening 88 in the viewing screen 30.
The sensor arm 86 is connected to a paper registration
sensor switch 90 that is connected to the control
circuit. When the registration sensor switch 90 is
tripped, it causes the paper transport motor 82 to
turn off thereby stopping the first and second feed
rollers 70 and 74.
During the feeding of the dry silver paper
from the cassette, the lamp 18 was deenergized and
the cafe doors 36 were closed. This is critical as
the dry silver paper is light sensitive and must not
be subjected to stray light. When the dry silver
paper is in its proper imaging position, the lamp 18
is momentarily energized, projecting the image onto
the dry silver paper. After the predetermined imaging
time, the lamp 18 is deenergized and the paper trans-
port motor 82 is energized. This causes the first
and second feed rollers 70 and 74 to drive the paper
into a developing station 92.
At the developing station 92 there is a
developer motor 94 connected to a developer roller 96
which has a brush fiber surface 98 thereon. Surround-
ing the brush surface 98 is a developer shoe 100 tha~
is connected to a power source. The developer shoe
100 is heated to a predetermined temperature to cause
the latent image on the dry silver sheet to develop
as it is fed between the heater roller 96 and to the
developer shoe 100. The development time depends
upon the developer shoe temperature and the speed of
the heater roller 96. The developed dry silver sheet
is ~hen discharged onto a receiving tray 102.
The operation of the reader-printer 10 is
controlled by a control circuit illustrated schematic-
ally in FIG. 5 and designated as a whole by the re~er-
ence character 110. Circuit 110 includes a pair of
power supply terminals 112 and 114 adapted to be con-
nected as illustrated to a nominal 120-volt alternating
current power suppl~ 116. The mode of operation of
the control circuit 110 is selected by means of a
double-pole, double-throw mode selector switch 118
(FI~S. 1, 2 and 5). Switch 118 is illustrated in its
off position with no power supplied to control circuit
110.
For viewing of a microimage projected upon
the viewing screen 30, the mode selector switch 118
is operated to a "view" position in which projection
lamp 18 is energized at a maximum intensity by the
control circuit 110. In the view position of switch
118, contacts 118A are closed to supply power to an
illumination control circuit 119 including normally
closed timer-controlled contacts 38A and 38B and the
primary winding 120 of a voltage reduction transformer
1~2. Contacts 38A and 38B are controlled in the manner
described below by the timer motor 38. Transformer
122 includes a secondary winding 124 in circuit with
the projection lamp 18, and the transformer 122 pro-
vides the proper operating voltage for the lamp 18.
In the illustrated embodiment of the invention, the
lamp 18 operates at 13.8 volts.
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In order to make a printed copy of the pro-
jected microimage, the mode selector switch is moved
to an alternate l'print" position in which contacts
118B and 118C are closed. Contacts 118B and 118C
supply power from the power supply terminal 112 to a
-printing sequence control network generally designated
as 126 while contacts 118C supply power for operation
of the timing motor 38 and the illumination control
circuit 119 during a print cyc:le.
In addition to rotat:ing the cam ~0 for clos-
ing doors 36 durin~ the print cycle, the timer motor
38 also operates an electromechanical timer device
including sequence controlled switch contacts 38A,
38B, 38C, 38D and 38E. These contacts are operated
respectively by a series of cams 39A, 39B, 39C, 39D
and 39E (FIG. 6) rotated through a timer reduction
gear (no~ shown) by the motor 38. In the preferred
arrangement, the motor 38 and drive gear aee arranged
so that the switch control cams of the timer mechanism
complete one revolution in thirty seconds, this being
the duration of a print cycle of the reader-printer
10 .
The sequence of operation of the contacts
controlled by timer motor 38 is shown graphically in
the chart illustrated as FIG. 6 of the drawings. Cams
39A, 39B, 39C, 3~D, 39E and 40 are shown diagrammatic-
ally in the home position adjacent corresponding por-
tions of a timing sequence chart wherein shaded por-
tions represent the closed condition of the timer
controlled contacts 38A, 38B, 38C, 38D and 38E.
Many electromechanical timers well known to
those skilled in the art may be used for operating
the timer controlled contacts in the desired sequence.
The preferred embodiment of the invention makes use
of a Singe~ Model 146 electromechanical timer. It
should also be understood that features of the inven-
tion may be achieved with other types of timing ar-
* Trade Mark
. ~
rangements~ including but not limited to other types
of electromechanical timers, time delay relay con-
trolled circuits and circuits controlled electronically
as by microprocessors or other logic devices.
When the "print" mode is selected, contacts
118B supply power in the network 126 to an electrical
resistance heating element 111 of the developer shoe
100. During the time require~ for the developer shoe
100 to reach its elevated operating temperature, con-
tacts 118C continue to supply power to the illuminationcontrol circuit 119 including the projection lamp 118
through a circuit branch 127 so that continued viewing
of the projected image on the viewing screen 30 is
possible.
The operating temperature of the developer
shoe 100 is regulated by a solid state switch, such
as, for exa~ple, a triac 128 connected in series with
the developer shoe heating resistance element 111.
The triac 128 is controlled by a solid state tempera-
ture regulating circuit including a zero-crossing
switching network 135 and associated components includ-
ing resistors 136 and 137, a variable resistor 138, a
capacitor 139 and a temperature sensitive resistive
element such as a thermistor 1400 In the illustrated
embodiment, the zero-crossing switching network takes
the form of a type 3059 integrated circuit manufactured
by RCA and other manufacturers, but other switching
networks may be used. The thermistor 140 is in heat
transfer relationship with the developer shoe 100 and
has a resistance that varies as a function of the
temperature of the developer shoe 100. The variable
resistor 138 provides a temperature adjustment for
setting the desired temperature of the developer shoe
100. The network 135 monitors the voltage at the
junction of the variable resistor 138 and the thermis-
tor 1~0 and applies a gating signal to the triac 128
to trigger the triac 128 whenever the voltage at the
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junction of the variable resistor 138 and the thermis-
tor 140 indicates that the temperature of the developer
shoe 100 is too low. The triggering is done during
zero crossings of the AC voltage waveform to minimize
the generation of transients. The capacitor 139 serves
as a filter capacitor for the temperature sensing
network. Other electrical, mechanical and electro-
mechanical controllers could a]Lso be used. For
example, the triac 128 could be replaced with a relay.
Alternatively, the entire temperature control circuit
could be replaced by a mechanical switch, such as,
for example, a bimetallic strip in contact with the
developer shoe 100 that provides a normally closed
switch in series with the heating element 111 that
opens when the temperatura of the developer shoe 100
reaches the desired temperature.
When the developer shoe 100 reaches the
desired operating temperature, normally open bimetal
controlled contacts 130 close to enable the beginning
of a print cycle~ Contacts 130 are also in heat trans-
fer relationship with the developer shoe lU0 and are
designed to close at a slightly lower temperature
than the contacts 128 to the end that the contacts
130 remain closed during cycling operation of the
contacts 128.
When the desired developer operating tempera-
ture has been reached and detected by closure of con-
tacts 130, a circuit is completed for energization of
an indicator lamp 132. As shown in FIGS. 1 and 2,
lamp 132 is located at the front of the reader-printer
10 and provLdes an indication that a print cycle can
be commenced.
A print cycle is carried out during each
single energ:Lzation of the timer motor 38. To initiate
a cycle, a manually operated push-button switch 134
(FIGS. 1, 2 and 5) is actuated. This momentarily
completes a circuit through the mode selector switch
1~7~)24
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contacts 118C and the bimetal controlled contacts 130
for energization of the timer motor 38. When the
timer motor 38 begins its cycle of rotation, timer
controlled contacts 38C are closed after an interval
of a fraction of a second and, as can be seen in FIG.
6, remain closed throughout a ]print cycle until the
cycle is completed. At the end of the cycle, contacts
38C reopen to discontinue energization of the timer
motor 38 in preparation for thle next subsequent cycle.
Contacts 38C provide an alternate path for
energization of the timer motor 38 independent of the
print switch 134 and bimetal controlled contacts 130.
Moreover, circuit branch 127 permits timer motor 38
to be energized by way of either contacts 118C or
118A after a cycle of operation begins and contacts
38C close. Thus, each time that a print cycle is
initiated, the timer motor 38 is positively controlled
to complete one full cycle independent of operation
of the mode selector switch 118 to the "view" positionO
20 The cycle is not stopped at any point during its pro-
gress and it is not possible for components operated
during the print cycle to inadvertently be operated
continuously. One advantage of this arrangement is
that the components can be rated for intermittent
rather than continuous use with a cost saving and
without danger of overheating or destruction of the
components.
When timer motor 38 is energized first by
print switch 134 and therèafter by contacts 38C, the
cam ~0 rotates in the manner described above to close
the viewing doors 36 and isolate the interior of the
reader-printer 10 from ambient light. The sequence
of operations then carried out by circuit 110 is con-
trolled by the timer-controlled contacts as illustrated
in FIG. 6.
As a print cycle commences, the projection
lamp 18 is controlled to prevent exposure of a sheet
-14-
of paper until it is properly positioned and is then
controlled to provide a regulated exposure intensity.
Normally closed contacts 38B open near the beginning
of a print cycle to prevent energization of the pro-
jection lamp 18. Thereafter, normally closed contacts
38A open to enable control o~ the intensity of projec-
tion lamp 18. When contacts 38A are openl the circuit
for supplying power to the transEormer 122 and lamp
18 includes a variable resistor 136 adjusted by a
knob 138 located at the front of the reader-printer
10 (FIGS. 1 and 2). When the dry silver paper sheet
is properly positioned for exposure after approximately
fourteen seconds, contacts 38B reclose for an exposure
interval of approximately three seconds. During this
interval, lamp 18 is energi~ed at a selected intensity
level by a circuit including the variable resistor
136 and closed contacts 38B. At the end of the expo-
sure operation, contacts 38B reopen to discontinue
energization of lamp 18, and shortly before the end
of the print cycle, the contacts 38A reclose to disable
the variable resistor 136 and restore the illumination
control circuit 119 for operation at maximum intensityr
Contacts 38B close after contacts 38A in preparation
for a subsequent viewing operation.
Cassette feed motor 68 is controlled to
advance a sheet of paper from the paper tray 34. Dur-
ing the print cycle, when projection lamp la is dis-
abled by opening of contacts 38B, normally open con-
tacts 38E are closed to energize motor 68. As a re-
sult, cassette feed rollers 64 advance the topmostsheet toward feed roller 70 and idler roller 72. The
normally closed switch 90 in series with contacts 38C
provide a circuit for energi~ing the paper transport
motor 82 so that the feed rollers 70 and 74 are rotat-
ing. When t:he topmost sheet reaches feed roller 70,
it is advanced by rollers 70 and 74 into the exposure
position. t'ontacts 38E remain closed for an interval
2 ~7~2
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of about four seconds, long enough to advance the top
sheet until its leading edge is engaged and further
advanced between rollers 70 and 72.
As the paper sheet reaches the proper posi-
tion for exposure, its leading edge engages sensor
arm 87 and operates paper registration switch 90 from
its illustrated closed to its open position. This
interrupts the circuit for energization o~ the paper
transport motor 82 and feed rollers 70 and 74 stop.
The paper sheet is held stationary in proper position
for exposure. While the sheet is stopped, the projec-
tion lamp 18 is operated by contacts 38B at a selected
intensity level in the manner described above until
the exposure operation is completed.
In order to advance the exposed paper sheet
to the developing station 92, normally open contacts
38D are closed at the end of the exposure interval
and provide an alternate circuit branch for energiza-
tion of the paper transport motor 82. Contacts 38D
remain closed for about ten seconds, and feed rollers
70 and 74 advance the paper sheet until its leading
edge engages and is further advanced by the heater
roller 96 in cooperation with the developer shoe 100.
The developer motor 94 operates continuously whenever
the print mode is selected by the mode selection switch
118 to the end that the components of the developing
station 92 are uniformly heated by the continuously
energized developer heating element 111. After the
trailing edge oX the paper leaves the nip of roller
86 and 74, contacts 38D may be reopened since further
energization of the motor 82 is not required. The
developing process may continue after completion of
the timer controlled print sequence.
As the exposed image on the paper sheet
moves through the developer station between roller 96
and shoe 100, it is developed by heatO The developed
sheet is advanced by roller 96 to the receiving tray
~7a~
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102 at the top of the reader-printer 10. As the print
cycle is completed, contacts 38C are reopened to stop
the timer motor 38 at a home position ready for initia-
tion of a further print cycle. If desired, the mode
selector switch 118 may be ieft in its "print" posi-
tion, and a further print cycle may be initiated by
again pressing the print switch 134 to reenergiæe
timer motor 38 and begin another complete print cycle.
Alternatively, the mode selection switch 118 may be
moved to the illustrated off position or may be re-
turned to the "view" position to reclose contacts
118A for further viewing of projected images.
While the invention has been described in
eonjunction with a specific embodiment, it is evident
that many alternatives, modifieations, and variations
will be apparent to those skilled in the art in light
of the foregoing deseription. Aeeordingly, it is
intended to embrace all such alternatives, modifica-
tions and variations as fall within the spirit and
broad seope of the appended elaimsD
