Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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FILM sr~ AND/OR RECO~D~R WITt~ TIPLE FIL.M PAT88
FIE~D OF T~IE lNVL~ ON
The present invention relates to an image transfer
system incorporating multiple film paths for the high speed
conversion of digital data to film and for reading film to
produce digital image information.
~ POUIlD OF THE INV~NTIO~I
In motion picture, television, video, and broadcasting
production, high speed sc~ners have been employed for
recording and for re~;n~ media for years. A scanner is an
optomechanical system that deflects light and/or moves the
light in relation to the media to produce motion of a focused
spot so that by observing the intensity of the transmitted
light information is read and by varying the intensity of the
spot information is written. Thus, reading involves using a
scanner to recover digital data from a previously exposed
media while writing involves exposing media in accordance
with digital data.
Internal drum scanners that use lasers for the re?~;ng
and writing of media are well known in the art. Such
scanners are disclosed in U.S. Pat. No. 3,316,348, issued to
Hufnagel et al., which discloses a scanner for recording
using laser light from a moving aircraft that is reflected
from terrain to modulate a second laser beam which exposes
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photographic film; in U.S. Pat. No. 3,465,352, issued to
Carlson et al., which discloses a scanner for recording and
scanning a document to a microfilm; in U.S. Pat. No.
3,4S7,422, issued to Rottman, which discloses an optical
system with a scanner for scanning an image and rotating it;
in U.S. Pat. No. 3,816,652, issued to Barnett, which
discloses a laser facsimile transceiver that uses a scanner
for reading and writing a document; in U.S. Pat. No.
4,015,081, issued to Starkweather,which discloses a scanning
system that uses a modulated and an unmodulated light beam
for writing and reading, respectively, with the beam striking
the same facet of a polygon scanner either at the same
location or at spaced apart locations aligned with an axis of
the rotating polygon scanner; in U.S. Pat. No. 4,236,183,
issued to Howe, which discloses optical configurations for a
rotating polygon film scanner; and, in U.S. Pat. No.
3,958,250 which discloses a photographic data plotting system
using a modulated laser light that scans a photographic film.
All of the previous devices provide one path for reading
or writing. U.S. Pat. No. 2,831,055, issued to Mattke,
discloses a film projector capable of scanning multiple films
at one time. The Mattke device consists of a scanner
composed of an array of plane mirrors arranged around a
circle with each mirror mounted on an axis parallel to the
axis of the circle. Curved film gates support the film as
scanning light passes through it. Since the projector circle
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is large in comparison to the film gates, a large amount of
scanning area is wasted. Besides being cumbersome, this
device also does not provide any means for recording onto
film. Moreover, films with different widths are not easily
accommodated in this device since a film of a different width
would presumably involve dismantling the film gate and
substituting another film gate appropriate for the film
width.
In the prior art, only 180 degrees or less of the
sc~nn;ng area is used although the internal drum scanner has
the capability to scan 360 degrees. Smaller format film such
as motion picture film uses even less of the available
sc~nn; ng area in each rotation of the scanning reflector.
Accordingly, it is the object of this invention to provide an
improved image transfer system that uses the scanner
reflector more efficiently.
In order to scan different widths of films, a different
path for each size of film must be provided. In conventional
apparatus, this means changing the mechanical apparatus of
the film path and sometimes the film holding cylinder itself.
This is not desirable since the alignment of the cylinder to
the axis of rotation and axis of linear translation of the
scanner is set at a very high degree of precision and
changing cylinders disrupts this alignment. It is another
object of the invention to provide an image transfer system
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that can read or write on a wide variety of films with
different widths without dismantling the components of the
devlce .
S Furthermore, re~;ng and writing of film require
different components. In addition, the film and, thus, the
film handling differ in significant ways for re~;ng and
writing. Yet another object of the invention is to provide a
device that allows the user an easy way to switch between
reading and writing modes.
SU~nS~RY OF TH~ INV~NTION
According to the invention, there is provided an optical
apparatus for high speed conversion of digital data to film
and for reading film to produce digital data information.
The apparatus is comprised of a scanning reflector that is
rotatable about an axis of rotation and that is reversibly
translatable in a direction parallel to the axis of rotation.
It includes a light source that emits light beams that are
focused by a lens assembly onto the facets of the reflector
and a modulator which can modulate a light beam in accordance
with digital data so that the light beam records onto a light
sensitive film associated with the light beam. It further
includes a plurality of film transporters which move film
paths in a direction transverse to the axis of rotation of
the scanner.
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The apparatus may have a second modulator which
modulates a second light beam and records onto a second film
that is light sensitive.
S The apparatus may further have a light reader that reads
digital information from the intensity of a second light beam
that passes through an exposed film.
The scanning reflector may have one or more facets that
reflect light beams.
Preferably, there is further provided a cylindrical
housing concentric with the axis of rotation of the
reflector. Films may be mounted on the inner surface of the
cylindrical housing or on the outside of the housing over
openings present in the housing. Different frames with
different aperture widths may be used to mount films of
different widths. The cylindrical housing may have a light
impervious chamber and a removable light shield to prevent
light from exposing a light sensitive film when another film
is being scanned.
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BRIEF DESCRIPTION OF THE DRAWING~
The novel features believed to characterize the
invention are set forth in the appended claims. The
invention, itself, however, as well as other features and
S advantages thereof, will be best understood by reference to
the detailed description which follows, read in conjunction
with the accompanying drawings, wherein:
Fig. 1 is a perspective view of an image transfer
system in accordance with a preferred embodiment of the
invention;
Fi~. 2a is a front view of a holding plate for one
film;
Fig. 2b is a front view of a holding plate for a second
film;
Fig. 3a is a schematic view of a cylindrical housing
with three film paths;
Fig. 3b is a schematic view of a cylindrical housing
with four film paths;
Fi~. 4 is an end view of an embodiment of one film
being read on two film paths;
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Fi~. 5 is an end view of an embodiment with one light
beam and two film paths;
Fig. 6 is an end view of an embodiment with two light
S beams and two film paths;
Fig. 7a is an end view of an embodiment for writing on
two film paths;
Fig. 7b is an end view of an embodiment for reading on
two film paths; and
F~. 8 is an end view of an embodiment for reading a
film on one film path and writing on another film path.
DETAI~D D~SCRIP$ION OF THE PR~F~RPRn ~MBODIMENT
Referring to Fig. 1, there is shown in perspective an
image transfer system comprising a light source 57, a laser,
from which a light beam 13 is generated. An image lens 12
focuses the beam of light 13 onto the scanning reflector 3
which is mounted on the axis of cylinder 30. Sc~nni ng
reflector 3 is rotated by sC~nn; n~ motor 7. An optical
rotary encoder 11 is affixed to the shaft of the scanning
motor 7 in order to indicate its angular position. A
translation stage 8 driven by translation drive motor 10
causes linear movement of motor 7 in a forward and reverse
direction. A linear encoder 9 provides information as to the
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axial position of the motor 7 including the scanning
reflector 3. Concentric with the axis of rotation of the
scanning reflector 3 is a larger cylinder 1 which is used as
a support for film while it is read or exposed by the light
S beam 13 that is being focused by image lens 12 and deflected
by scanning reflector 3. The supporting surface may be any
curved shaped other than a cylinder provided that the locus
of the focal point is not substantially changed when
scanning.
For so~e purposes, the film may be inside the cylinder
1, in which case, openings 2 are not needed. In this
embodiment, two film paths are shown on the outside surface
of the cylinder 1. On each side of the cylinder 1, there are
lS two openings 2 to permit the light to pass through the
cylinder from the scanning reflector 3 to the films 5 and 6.
For reading and writing on each film, holding plates 35 and
36 serve as a frame around each film S and 6 and keep each
of the film 5 and 6 in uniform contact with the cylinder 1
over the area to be read or exposed. Referring to Fig. 2a
and Fig. 2b, a film 30 has a width that is greater than the
width of film 31. The two films use two different holding
plates 35 and 36 which have the same overall width 34 that
is approximately equal to the width of the opening in the
cylinder on which the holding plates are mounted. The
holding plates 35 and 36, thus, serve as an adapter that
determines the maximum size of the opening 2. The holding
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plate may also have an adjustable frame that can be changed
to fit the width of the film. An advancing device advances
the film to the holding plate.
S If the film is perforated as in the case of film 6, the
perforations may be registered with registration pins (not
shown). The registration pins are insertable into the
perforations of the film. A device that withdraws the pins
from particular perforations in the film at both sides of the
opening and another device that provides other pins to engage
other perforations in the film may be present. The two
devices operating in concert advance the film a fixed number
of perforations and therefore a fixed distance. Each film
frame thus has a fixed and repeatable position on the film
with respect to previous and successive film frames.
In an alternate embodiment, the registration pins are
fixed on the film holder or cylinder. Instead of devices
that move the pins in and out of film perforations, the film
is lifted off the registration pins and advanced a fixed
number of perforations and then reset on the registration
pins of the holding plate by another device.
Referring to Fig. 3a, the cylinder 1 may also have three
openings, thus providing an image transfer system which
allows three films 37, 38, 39 to be scanned or it may have
four openings as shown in Fig. 3b allowing four films 40,
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41, 42, 43 to be scanned. More than four openings are
possible also. Each opening in the cylinder has its own
means of holding, registering, and advancing the film (not
shown).
Referring to Fig. 4, in an alternative embodiment,
instead of having two films, only one film 56 may occupy both
openings. One section of the film may be threaded through
one opening while another section of the same film may be
threaded through a second opening with the aid of two rollers
58 and 59. The two films may be scanned concurrently or the
slack loop of film 60 can be configured so that one station
is scanned while the other advances the film.
Referring to Fig. 5 and Fig. 6, there is shown a view
looking into an end of an image transfer system along an axis
thereof that the beam of light enters to strike the scanning
reflector 3. In Fig. 5, there are two film paths with two
films 5 and 6 secured to two openings in the cylinder 3 and
one light source ~not shown), which emits one light beam 13.
In addition, the scanning reflector 27 is multifaceted, with
four facets 28. For each facet 28 there is a focusing lens
26 positioned to focus light reflected from a facet 28 into
a focused spot 29 onto the film. The focusing lenses 26
2~ rotate with the scanning reflector 27. Because of the
configuration of the facets 28 of the scanning reflector 27
and the focusing lenses 26, the beam of light 13 must be
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located away from the central axis of the cylinder 1 so that
the beam 13 can be deflected onto the sides of the cylinder
1 where the films 5 and 6 to be read or exposed are
positioned. Since only one source of light is present, only
S one film can be scanned at a time. The selection of which
side of the cylinder 1 to scanned is made by a moveable
mirror 16. The moveable mirror 16 when placed in location,
14, deflects the light beam 13 allowing it to strike the
scanning reflector 27 on the facet 28 suitable for exposing
or reading film 6. When moveable mirror 16 is moved to a
position, lS, the light beam 13 is deflected towards the
facet 28 of the scanning reflector 27 suitable for exposing
or reading film 5.
lS Referring to Fig. 6, a similar arrangement to Fig. 5,
with two film paths having two films 5 and 6 secured to two
openings in the cylinder 3, a multifaceted sc~nn;ng reflector
27 and focusing lenses 26, is shown. The difference between
the two embodiments is that in this embodiment two light
sources emitting two independent light beams 19 and 20 are
present. The two light sources, in this embodiment, are two
separate lasers. In other embodiments, the light source can
comprise of a combination of multiple lasers, for e.g. a
combination of laser emitting red light, another laser
emitting green light and a laser emitting blue light, or
light source can simply be a source of white light. In
addition, two mirrors 17 and 18, which deflect the light
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~ beams 19 and 20 to the two appropriate facets 28 of the
scanning reflector 27 are provided. Thus, light beam 20
travels to mirror 18 which deflects light beam 20 towards
facet 28 on the scanning reflector 27. Facet 28, furthers,
deflects the light beam 20 towards the appropriate focusing
lens 26 which focuses light beam 20 onto film S. Similarly,
light beam 19 is deflected by mirror 17 to an opposite facet
28 on the scanning reflector 27. Facet 28, further,
deflects the light beam 20 towards the appropriate focusing
lens 26 which focuses light beam 19 to film 6.
Referring to Fig. 7~, when the sc~nning reflector is
operating as a recorder for recording digital data on
unexposed film 46 and 47 in both film paths, the light beams
48 and 49 are modulated by light modulators 4~ and 45
according to digital image data.
Referring to Fig. 7b, when the scanner is operating as a
reader of films 52 and 53 rather than a film recorder,
20 sc~nn; nn light collectors 50 and 51 are present instead of
light modulators. The scanning light collector comprises of
photodiodes or photomultiplier tubes which collect and detect
the intensity of light. The scanning light collector may
have additional mirrors to focus light into a small spot at
the face of the detectors. In addition, the collector may
also have an optical system of mirrors to reflect certain
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wavelengths of light to photomultipliers so that information
about color as well as intensity is collected.
Referring to Fig. 8, there is shown a view looking into
S the end of the image transfer system along the axis that the
beam of light may enter to strike the multifaceted scanning
reflector 3. In Fig. 8, there are two film paths with two
films 24 and 25 secured to the two openings on the outside of
cylinder 1. Film 24 is an exposed and processed film that
is to be read while film 25 is an unexposed film that is to
be written upon by exposing it to a modulated light beam.
While film 24 is read by the sc~nning of light by the
scanning reflector over the film and onto the sc~nn; ng light
collector and detector, unexposed film 25 is protected by a
lS light tight compartment 22 and removable light shield 23.
The light shield 23 is mechanically removed when film 25 is
to be exposed and modulated light beam is scanned with the
scanning reflector 3 onto film 25.
While the present invention has been described with
particularity, it should be understood that various
modifications and alterations may be made therein without
departing from the spirit and scope of the invention set
forth in the appended claims.
