U.S. patent number 3,598,489 [Application Number 04/788,378] was granted by the patent office on 1971-08-10 for projection system.
This patent grant is currently assigned to Spaco, Inc.. Invention is credited to Clarence E. Ellis, Doyle W. Thomas.
United States Patent |
3,598,489 |
Thomas , et al. |
August 10, 1971 |
PROJECTION SYSTEM
Abstract
A photographic system for projection of images on a continuous
flow basis between a medium carrying images and a medium being
exposed to them and providing for adjustable magnification or
reduction of images and wherein the speed or travel of the viewed
and exposed media are precisely determined and synchronized in
accordance with the speed of one of them and the ratio of image
magnification or reduction.
Inventors: |
Thomas; Doyle W. (Huntsville,
AL), Ellis; Clarence E. (Huntsville, AL) |
Assignee: |
Spaco, Inc. (Huntsville,
AL)
|
Family
ID: |
25144307 |
Appl.
No.: |
04/788,378 |
Filed: |
January 2, 1969 |
Current U.S.
Class: |
355/51; 318/77;
355/57; 355/66; 318/69; 318/625; 355/60 |
Current CPC
Class: |
G03B
27/50 (20130101) |
Current International
Class: |
G03B
27/50 (20060101); G03b 027/70 () |
Field of
Search: |
;355/51,40--43,57,60,65,66 ;318/69,77 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Matthews; Samuel S.
Assistant Examiner: Wintercorn; Richard A.
Claims
What we claim is:
1. A projection system for projecting images between first and
second focal planes comprising:
A. lens means responsive to an image appearing at a predetermined
location in one of said focal planes for projecting said image in
the other said focal plane at a predetermined location;
B. a plurality of mirrors spaced along and providing an optical
path between said images comprising:
1. a first mirror positioned to receive images from and transmit
images to one of said focal planes;
2. a second mirror positioned to receive images from and transmit
images to the other of said focal planes; and
3. third and fourth mirrors, said third mirror being positioned to
transmit images between said fourth mirror and said first mirror
and said fourth mirror being positioned to transmit and receive
images between said third mirror and said second mirror; and
C. image size adjustment means comprising positioning means
attached to at least one of said mirrors for varying the path
length between the images whereby the relative size of said images
is varied without varying the said locations.
2. A projection system comprising:
A. a first rectangular aperture having a length substantially
longer than its width;
B. a first reeling system for moving a first elongated sheet of
image material across and adjacent to said aperture wherein the
width dimension of said material is oriented to be exposed to the
length dimension of said aperture;
C. a second rectangular aperture having a length substantially
longer than its width and being smaller in both dimensions than
said first aperture;
D. a second reeling system for moving a second elongated sheet of
image material across and adjacent to said second aperture wherein
the width dimension of said second elongated sheet of image
material is oriented to be exposed to the length dimension of said
second aperture;
E. projection means for projecting an image appearing in a focal
plane of one of said sheets of material at a said aperture on to
the focal plane of the other of said sheets of image material at
the other said aperture;
F. image size adjustment means comprising means for continuously
varying the optical path length between a said image and its
projected image;
G. first electrical drive means for driving said first reeling
system to cause said image material to traverse said first aperture
at a selected speed;
H. second electrical drive means for driving said second reeling
system to cause said image material to traverse said second
aperture at a selected but continuously variable speed;
I. first speed control means for regulating the speed of said first
electrical drive means; and
J. second speed control means responsive to the speed of said first
electrical drive means and the ratio of the size of a said image in
one said focal plane and its projection in the other said focal
plane for regulating the speed of the said second electrical drive
means.
3. A projection system as set forth in claim 2 wherein:
A. said second electrical drive means comprises an electrical motor
coupled to drive said second reeling system;
B. speed-sensing means responsive to the speed of said first
electrical drive means for providing an electrical signal
proportional to the speed of said first electrical drive means;
C. said second speed control means comprising means responsive to
output of said speed-sensing means for applying as on input to said
second electrical drive means the fraction of the output of said
speed-sensing means corresponding to the said ratio of the sizes of
said images.
4. A projection system as set forth in claim 2 wherein said image
size adjustment means comprises:
A. a plurality of mirrors spaced along and providing an optical
path between the images appearing in the said focal planes; and
B. said image size adjustment means comprises positioning means
attached to at least one of said mirrors for varying the path
length between the images whereby the relative size of said image
is varied without varying the location of either a said image in
one said focal plane or its projected image in the other said focal
plane.
5. The projection system set forth in claim 4 wherein said
plurality of mirrors comprises:
A. a first mirror positioned to receive images from and transmit
images to one of said focal planes;
B. a second mirror positioned to receive images from and transmit
images to the other of said focal planes; and
C. third and fourth mirrors, said third mirror being positioned to
transmit images between said fourth mirror and said first mirror
and said fourth mirror being positioned to transmit and receive
images between said third mirror and said second mirror.
6. A projection system as set forth in claim 5 wherein said image
size adjustment means comprises means for selectively varying the
distance of said third and fourth mirrors from said first and
second mirrors.
7. A projection system as set forth in claim 6 wherein the optical
path between said first and third mirrors and optical path between
said second and fourth mirrors are parallel and wherein said image
size adjustment means comprises means for moving said third and
fourth mirrors in unison along a linear path.
8. A projection system as set forth in claim 2 wherein said image
size adjustment means comprises:
A. a first mirror positioned to receive images from and transmit
images to one of said focal planes;
B. a second mirror positioned to receive images from and transmit
images to the other of said focal planes;
C. third and fourth mirrors, said third mirror being positioned to
transmit images between said fourth mirror and said first mirror
and said fourth mirror being positioned to transmit and receive
images between said third mirror and said second mirror.
D. adjustment means for selectively varying the distance of said
third and fourth mirrors from said first and second mirrors.
E. ratio signal means responsive to the position of third and
fourth mirrors for providing and electrical output proportional to
the ratio of magnification between said images.
F. summing means for electrically adding the output of said ratio
signal means and an electrical signal proportional to the ratio of
speed of said first and second drive means and applying the sum
signal to said second drive means;
G. first speed-sensing means responsive to the speed of said second
drive means for developing an electrical output proportional to the
reciprocal of said speed of said second drive means;
H. second speed-sensing means responsive to the speed of said first
drive means for developing an electrical output proportional to the
speed of said first drive means; and
I. electrical multiplication means responsive to the outputs of
said first and second speed-sensing means for providing to said
summing amplifier said electrical signal proportional to the said
ratio of speeds of said first and second drive means.
9. A projection system as set forth in claim 8 wherein said image
size adjustment means comprises:
A. mounting means for movably supporting said third and fourth
mirrors; and
B. mirror drive means including a reversible motor and a
clockwise-counterclockwise switch for providing power to said
reversible motor, said motor being coupled to said mirror mounting
means for selectively moving said third and fourth mirrors along
said linear path to increase or decrease the distance of said third
and fourth mirrors with respect to said first and second
mirrors.
10. A projection system as set forth in claim 9 wherein said mirror
drive means further comprises a selective stop circuit in circuit
between said clockwise-counterclockwise switch and said reversible
motor comprising:
A. a plurality of normally closed selector switches connected in
series;
B. a plurality of normally closed position-sensing switches being
positioned to be operated "off" by said mirror-mounting means
contacting a said position-sensing switch, said position-sensing
switches being spaced along the travel of said mirror-mounting
means; and
C. each said selector switch being connected in parallel with a
single said position-sensing switch whereby when said
clockwise-counterclockwise switch is operated to an "on" condition
said mirror-mounting means will be moved along its path of travel
until the position responsive switch in parallel with an operated
"off" said selector switch is also operated "off", stopping the
travel of said mirror-mounting means.
11. A projection system as set forth in claim 10 further comprising
means for selectively positioning said position-sensing switches
whereby said third and fourth mirrors may be stopped at any of a
plurality of preselected points along the travel of said mirror
mounting means.
12. A projection system as set forth in claim 11 wherein said ratio
signal means comprises a potentiometer wherein the wiper arm of the
potentiometer is coupled for travel with said mirror-mounting
means.
13. A projection system as set forth in claim 12 further comprising
means responsive to movement of said mirror-mounting means for
varying the focus of said lens means for maintaining the focus of
said images.
14. In combination:
A. a first reeling system for moving a first elongated sheet of
material;
B. a second reeling system for moving a second elongated sheet of
material;
C. first electrical drive means for driving said first reeling
system at a selected speed;
D. second electrical drive means for driving said second reeling
system at a selected but continuously variable speed which is a
desired fraction of the speed of said first electrical drive means
comprising a motor coupled to drive said second reeling system;
E. speed-sensing means responsive to the speed of said first
electrically drive means for providing an electrical signal
proportional to the speed of said first electrical drive means;
and
F. speed control means comprising means responsive to the output of
said speed-sensing means for applying as on input to said motor the
fraction of the output of said speed-sensing means corresponding to
the desired ratio of speed synchronism between said first and
second electrical reeling systems.
15. In combination:
A. first and second electrical drive means adapted to provide
movements at different speeds,
B. ratio signal means for providing an electrical output
proportional to the desired ratio of speeds between first and
second electrically driven movements;
C. summing means for electrically adding the output of said ratio
signal means and an electrical signal proportional to the ratio of
the actual speeds of said first and second drive means and applying
the sum signal to said second electrical drive means;
D. first speed-sensing means responsive to the speed of said second
electrical drive means for developing an electrical output
proportional to the reciprocal of said speed of said second
electrical drive means;
E. second speed-sensing means responsive to the speed of said first
electrical drive means for developing an electrical output
proportional to the speed of said first electrical drive means;
and
F. electrical multiplication means responsive to the outputs of
said first and second speed-sensing means for providing to said
summing means said electrical signal proportional to the said ratio
of speeds of said first and second electrical drive means.
Description
This invention relates to photographic projection and printing of
material on a continuous flow basis, as for example where images
initially appearing on a long strip of paper or film are to be
enlarged or reduced on photographic media, paper or film.
The photographic printing of material on a continuous flow basis
generally involves two basic problems.
One is the problem of providing in a practical and economical
manner apparatus for varying the degree of magnification or
reduction of the image size between the paper or film carrying the
image and the paper or film to which the image is to be transferred
over a sufficient range of magnification or reduction. Ideally, the
range would cover from 7 times to 24 times magnification or
reduction continuously and by a single range adjustment.
Second is the problem of precisely regulating the movement or
travel of the paper or film being viewed and the paper or film
being exposed in accordance with the ratio of magnification or
reduction in image size.
Accordingly, it is an object of this invention to overcome these
and other problems and difficulties and to provide a projection
system and printer which will accurately, conveniently and with
minimum cost print on paper or film images which are an enlarged or
reduced facsimile of an original and which permits the continuous
printing of a series of distinct images or pictures or other
intelligence or data of varying lengths.
It is another object of this invention to provide an optical system
for the enlargement or reduction of projected images without the
necessity of relative movement of the focal planes between which
magnification or reduction of images is desired, and without the
necessity of multifocal length lens assemblies.
It is still a further object of this invention to provide a system
of maintaining precise relative speeds between a pair of transport
systems which transport long strips of paper or other material.
In accordance with the invention, the general and specific objects
of this invention are achieved by a combination of the following
features:
First, variable magnification or reduction is achieved by
interrupting the optical path between the viewed media and media
being exposed and interjecting an optical system for varying
optical path lengths by changing the position of at least one
mirror with respect to other optical elements of the system. As a
particular feature of this invention the optical system consists of
two sets of mirror assemblies in which the first mirror assembly
consists of two plane mirrors with surfaces disposed in planes
which are displaced 270.degree. and the second mirror assembly
consists of two plane mirrors wherein the two surfaces of the
mirrors are disposed in planes which are 90.degree. displaced. The
two mirror assemblies are positioned in optical alignment wherein
an image directed at a first mirror of the first mirror assembly is
reflected to the first mirror of the second mirror assembly, again
reflected to the second mirror of the second mirror assembly, then
reflected along a generally parallel path to the second mirror of
the first mirror assembly by which mirror the image is reflected on
an optical path leading to the focal plane where it is to be viewed
or to expose a photosensitive medium. Then by incorporating means
for varying the distance between at least two mirrors the overall
optical path length between focal planes is variable and thus the
degree of magnification or reduction is variable. Where only a
small portion of width of an image is being projected, which is
constant, the mirror widths of the mirrors of the mirror system may
be made small. The mirror lengths vary with the size image
appearing at the point of placement of a mirror. By width is meant
the dimension which corresponds to the slit width of the viewing
aperture, that is the aperture which exposes the photographic
medium.
In order to maintain the dimensional accuracy of reproduction,
precise control of speed of the medium carrying the images being
viewed and the medium being exposed must be maintained at a ratio
of speeds which is equal to the ratio of image sizes appearing at
the two apertures. To accomplish this, one of the two drive systems
employed is driven at a selected speed. The other drive system is
electrically controlled in speed by means of an electrical input
which is a selected fraction of an electrical signal proportional
to the speed of the first drive system. The selected fraction, of
course, is equal to the fraction of the reduction, or ratio,
between the images.
Other objects, features and advantages of the invention will become
more apparent from the following description when read in
connection with the accompanying drawings in which:
FIG. 1 is a schematic illustration of the system of the
invention.
FIG. 2 is a graph on which is plotted the relationship between
percentage of travel of a mirror assembly as shown in FIG. 1 with
respect to the magnification ratio of the system.
FIG. 3 is a block diagram and alternate system for controlling the
speed of the film drive motor shown in FIG. 1.
FIG. 4 is a side view, partly diagrammatic, illustrating the mirror
system of the invention.
FIG. 5 is a detailed drawing illustrating the method of mounting of
a microswitch or lever operated plunger switch shown in FIG. 4.
FIG. 6 is a schematic illustration of the electrical drive system
which adjusts magnification ratio.
FIG. 7 is a side view of the photographic paper magazine shown
partially in FIG. 11.
FIG. 8 is an elevation view of the arrangement of major components
of an embodiment invention.
FIG. 9 is a plan view of a film projection portion of the invention
as illustrated in FIG. 8.
FIG. 10 is a pictorial view of the exterior of one form of the
invention.
FIG. 11 is an exploded view of FIG. 10.
Referring now to FIG. 1, there is shown a system for transferring
images between focal planes 10 and 12. In this embodiment of the
invention, it is contemplated that the photographic medium 14 would
be in the form of a long strip of unexposed photographic paper, or
alternately, paper with printed images. In either instance it would
initially be wound on storage reel 16. The paper would then be
drawn by and wound on takeup reel 18 while being positioned within
focal plane 10 between aperture plates 20. Takeup reel 18 is driven
through an appropriate gearing system 22 by motor 24, which also
drives paper 14 at a desired constant speed through capstan 25.
Motor 24 is controlled by speed control system 26 in which a
desired speed is set by means of a selected voltage obtained from
potentiometer 28 which is applied to amplifier 30, which in turn
drives motor 24. Tachometer 31, which is driven by motor 24,
develops a voltage proportional to the speed of motor 24, and this
voltage is applied as negative feedback input to amplifier 30 to
insure that the speed of motor 24 is driven at the selected speed
despite variations in load on motor 24.
The image at focal plane 12 may be an image printed on film 32, or
an image received on an unexposed film 32 from an image appearing
on photographic paper 14, depending upon the mode of operation. In
either of the modes, the film is originally stored on reel 38, and
then passes between aperture plates 36 and is reeled or spooled on
takeup reel 34. The speed of film 32 across aperture slit 40 is
precisely synchronized with the movement of paper 14 across
aperture slit 42. As a particular feature of this invention, this
is accomplished by film speed control system 44 which derives a
reference voltage from potentiometer 46 and applies it to amplifier
48 which powers motor 50. Motor 50 drives capstan 49 through
reduction gear 52 which drive film 32 and takeup reel 34. The
voltage across potentiometer 46, derived from tachometer 31, is
proportional to the speed of motor 24, and thus by selecting a
voltage output which is that fraction of the total voltage
corresponding to the desired speed of motor 50, a precise control
of motor 50 can be obtained which corresponds to the desired ratio
of reduction of image sizes between focal plane 10 and focal plane
12. Tachometer 54 provides the desired negative feedback voltage to
amplifier 48 to achieve accurate regulation of motor 50.
As another feature of this invention, speed selection is achieved
by movement of wiper arm 55 of potentiometer 46 in a manner to be
described below.
Typically, the width of paper 14 would be substantially larger than
film 32, the latter being, typically, 35 millimeter film. Image
reduction or magnification, depending upon whether the image is
initially on the paper or film, is achieved by mirror assemblies 54
and 56. An image, for example, on film 32 is projected by means of
light source 58 to movable mirror 60, is reflected 90.degree. to
the side and then by mirror 115 (FIG. 9) is reflected 90.degree. up
through projection lens assembly 62 on to mirror face 64 of mirror
assembly 54. From mirror face 64 it is reflected to mirror face 66
of mirror assembly 56, then to mirror face 68, then on to mirror
face 69 of mirror assembly 54 and then on to paper 14. Mirror faces
64, 66, 68 and 69 are progressively of longer lengths in order to
accommodate the progressively larger image which occurs.
As still another feature of this invention, mirror assemblies 54
and 56 are relatively movable to vary the distance between them and
in this manner it is possible to vary the ratio of magnification,
or reduction of images with a single projection lens assembly 62.
This is accomplished by means of motor 70 which, as directed by
motor control 71, and through drive means 72, illustrated in FIG.
4, moves mirror assembly 56 toward or away from mirror assembly 54.
In varying the optical path length of the system, motor 70 also
controls through drive means 72 wiper arm 55 of potentiometer 46
and thus by means of motor control 71 both the image ratio and
speed ratio of the film and paper drives are precisely set by one
operation.
Where the initial image is on paper 14, and is to be photographed
on film 32, the image on paper 14 is illuminated by lights 73 and
the image travels in the reverse direction to that just described
and on to film 32. When the image is originally on paper 14, it is
projected on to mirror 69, then to mirror 68, then to mirror 66,
then to mirror 64, through projection lens 62, on to mirrors 104
and 60 and then on to film 32. To observe focusing of the image,
mirror 60 is reversed (dashed line position in FIG. 9) to that of
the position indicated in FIG. 1 and images are reflected out to
ground glass 74, ground glass 74 being the same distance from the
mirror 60 as the focal plane of film 32. In addition, the actual
image size appears on ground glass 74 and thus, image size can be
observed for adjustment in the same manner. Similarly, in instances
where the image is initially on film 32 and is projected upward to
paper 14, by moving mirror 69 (dashed line position in FIG. 4) from
the optical path the image is projected on to ground glass 76 where
it can be viewed and mirror assembly 56 and lens assembly 62,
manually or by means of motor 70, adjusted to achieve precise image
size and focus. Ground glass 76 is, of course, the same distance
from mirror 69 as is the focal plane in which paper 14 travels.
The magnification ratio of the system is determined as described
above by increasing or decreasing the path length between film and
paper which is accomplished by varying the distance between mirror
assemblies 54 and 56. The magnification ratio can be derived from
the following standard equation:
1/P +1/Q =1/ F
Where F is the focal length of lens 62, P is the distance between
one image source and lens or lens assembly 62, and Q is the
distance between the other image source and lens 62.
The magnification ratio is given by the ratio of P to Q, whereas
the optical path distance is given by P+ Q. Solving for the
magnification ratio m in terms of optical path distance results in
a relationship between these two variables as shown in the
following table:
---------------------------------------------------------------------------
M P +Q .times. Distance % of Travel
__________________________________________________________________________
7 10.08 0 0 10 13.42 3.34 17.9 12 15.6 5.52 29.6 14 17.78 7.70 41.2
16 19.97 9.98 53. 18 22.16 9.98 64.7 20 24.46 14.38 77. 22 26.55
16.47 88.3 24 28.75 18.67 100.0%
__________________________________________________________________________
The data in this table was prepared for a 35 mm. lens for
magnification ratios between 7 to 1 and 24 to 1. This data is
plotted in FIG. 2, however the optical path length P+ Q is replaced
with a percent of travel of mirror assembly 56. This latter
variable is, of course, equivalent to an electrical signal that may
be derived from the movement of mirror assembly 56. The
relationship can be seen to be very linear between the ratios of 10
to 1 and 24 to 1. Within this range a voltage derived from movement
of mirror assembly 56 is directly proportional to the desired
magnification ratio. In smaller ratios it is necessary to make
corrections for the nonlinearity, which can be simply built into
the system. For example, in developing an appropriate electrical
signal representative of magnification ratio, potentiometer 46
would be appropriately wound to compensate for the nonlinearity
illustrated in FIG. 2.
FIG. 3 illustrates an alternate electrical circuit for
synchronizing paper and film speeds. This circuit functions to
synchronize the speed of paper 14 and film 32 by maintaining the
magnification ratio, as determined by the optical system, equal to
v.sub.p / v.sub. f , the ratio of the velocity of paper 14 with
respect to film 32. The optical magnification ratio m is obtained
in the form of voltage from potentiometer 46 and is applied as one
input to summing amplifier 80. In this circuit potentiometer 46 is
powered by a fixed reference potential instead of an output of
tachometer 31 as shown in FIG. 1. Also applied to summing amplifier
80 is a voltage proportional to v.sub. p / v.sub. f as derived from
actual speeds of paper 14 and film 32 as will be described below.
The output of summing amplifier 80 is then fed to power amplifier
82 and then to motor 50 which in turn drives film drive 52 which
drives film 32. Tachometer 54 is driven by motor 50 and provides an
electrical signal proportional to the speed of motor 50, which
signal, v.sub. f, is inverted by inverting amplifier 84 to produce
a voltage proportional to the inverse of film speed, 1/v.sub. f.
This signal is then multiplied in multiplier 86 by a voltage
proportional to the paper speed, v.sub. p derived from tachometer
31 which is then fed to summing amplifier 80 as a signal v.sub.p
/v.sub.f. Thus, the system functions by providing an input to power
amplifier 82 which includes an error signal, which is the
difference between m and v.sub.p /v.sub.f causing motor 50 to be
driven at such speed as will correct any error and thus drive the
speed ratio of v.sub.p /v.sub.f in to coincidence with the
magnification ratio m.
Referring to FIG. 4, depending upon direction of rotation of worm
gear 90, mirror mount or mounting assembly 92 moves mirror assembly
56 closer to or further away from mirror assembly 54. At the same
time, support 96 attached to mirror mount 94 also moves wiper 55 of
potentiometer 46 to provide an output voltage which is
representative of the ratio of magnification of the system of FIG.
3 (or selected fraction of paper speed per FIG. 1) as adjusted by
the distance between mirror assemblies 54 and 56.
The magnification setting of mirror mount 92 may be achieved by
means of prepositioned stops or microswitches 104 or by viewing the
projected image on ground glass 76 or 60 and causing motor 70 to be
operated in the direction which brings the image to desired
size.
Referring to FIGS. 4--6 there is shown a system of control for
motor 70. A source of 110 volt AC is applied to terminals 105 of
motor control 71 and applied through a direction selector switch, a
normally open double-throw, triple-pole switch 106 to reference
winding 107 of motor 70 and through normally closed selector
switches 108 and normally closed lever operated or microswitches
104, in parallel, to winding 109 of motor 70.
Microswitches a to d of microswitches 104 are adjustably movable on
guide bar 110 being held by spring mounts 111. These switches are
positioned to be operated "open" by a pawl 112 on mirror mount 92
at positions corresponding to preselected magnification ratios.
In operation, assume first that a purely visual method is to be
used to determine the image to be projected on paper 14 from film
32. Mirror 69 is moved down to horizontal position and out of the
way to permit the projected image to be projected on ground glass
76. Then, depending upon whether the image is to be made larger or
smaller, switch 106 is operated for clockwise or counterclockwise
operation of motor 70. In this general mode of operation all panel
selector switches 108 are left in their normally closed position
and power is supplied to motor 70 until the desired image size is
observed, whereupon the operator would open switch 106.
If one of the preset ratios is desired then the particular selector
switch 108 is operated which is electrically in parallel with the
particular microswitch 104 which is positioned for cutoff at the
desired ratio. Assuming, for example, that it is the ratio
represented by microswitch 104C, thus panel switch 108C would be
operated open. Next, switch 106 would be operated on, either
clockwise or counterclockwise, as required, to cause mirror mount
92 to move until it actuates switch 104C which removes power from
motor 70 and mirror assembly is stopped and positioned for the
selected image size.
It is, of course, necessary each time that there is a change in
magnification ratio that lens 62 be refocused. Accordingly, as
another feature of this invention, and as shown in FIG. 1, motor
drive 72 and mirror assembly 56 are also connected through
appropriate drive means, not shown, to lens 62 whereby the barrel
of lens 62 is rotated in a conventional manner to adjust lens 62 to
follow and maintain focus of the system in accordance with the
optical path length between the focal planes of paper 14 and film
32. Alternately, lens 62 can be independently focused by
disconnecting it from drive 72. While not shown, switch-operating
means may be included to automatically reverse switch 106 at each
end of travel of mirror mount 92 (FIG. 6) so that mirror mount 92
will be moved to a cutoff position regardless of which way switch
98 is initially operated.
Referring now to FIGS. 8 and 9 and assuming that images on film 32
are to be projected and exposed on paper 14, light source 58 is
turned on. Bulb 113 projects lights through condenser lens assembly
114 and through film 32. Images on film 32 are then directed from
aperture 36 to mirror 60 which reflects the images to the left to
mirror 115 which reflects the images, this time upward, to lens 62.
Lens 62 then projects the images through mirror assembly 54 and 56
up through aperture 42 and slit 118 of paper magazine 120 (FIG. 7)
and on to paper 14. Paper 14, initially on supply reel 16, passes
under capstan 25 and between capstan 25 and belt 124, then between
belts 124 and 126, to reel 18. Belts 124 and 126 are each of at
least the width of paper 14 and as paper 14 passes between these
belts it is flattened so that it will be positioned in a plane when
passing slit 118 which is aligned with focal plane 42. Slit 118 is
adjustable in width and by means of slide holder 130 and it may be
closed to prevent light from entering when magazine 120 is not in
use, and when containing sensitized paper.
Belt 124 is supported by rollers 132, 134 and 136 and paper 14 is
fed between capstan 25 and belt 124 at a precise speed as
determined by capstan 25. Belt 126 is an idler belt and is
supported by rollers 138 and 140. Takeup reel 18 is driven by means
of belt 142 and frictional drive 144 and braking torque is applied
to reel 16 by means of belt 146 and frictional coupling 148.
Referring again to film 32 and FIGS. 8 and 9, film 32 is driven by
capstan 49 as it passes between it and pinch roller 150. In
unwinding from reel 34 and winding on reel 38, film 32 also passes
between guide rollers 154 and over guide rollers 156. Belts 158 and
160 provide a frictional drive torque to reel 38 through friction
drive 162 and a drag torque to reel 34 through frictional coupling
164. Thus, the film is positively driven at a precise speed by
means of capstan 49 from drive motor 50 including reduction gears
shown diagrammatically in FIG. 1 and a drive tension is applied to
takeup reel 38 and a drag tension applied to supply reel 34.
FIG. 10 generally shows the housing of the system heretofore
described. It consists of main assembly cabinet 170 and removable
paper magazine 120.
FIG. 11 shows pictorially rack 172, on which the basic assembly is
mounted, cabinet 170 and paper magazine 120. By making paper
magazine 120 detachable, different size paper may be employed by
merely substituting magazines having the desired paper size. Motor
drive 174 for paper 14 is also located in housing 170 (FIGS. 8 and
11) and is coupled to capstan 25 by means of a shaft 176 and
coupling 178 in a manner, not shown, wherein the drive is quickly
disconnected by simply lifting magazine 120.
From the foregoing, it will be understood that the applicants have
provided a new system of projection on a continuous basis between
film 32 and paper 14 which are moved at a relative speed precisely
set and automatically maintained.
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