Method and system to scan motion picture film to develop television signals

To derive TV signals in standard TV interlace scanning format upon continuous scanning of motion picture film, line by line, the scanned signals are stored in a memory and the lines of the film frame, as they are being scanned, are assigned individual line addresses which permits read-out, in accordance with standard TV signal standards, from the individual addresses. In a preferred form, alternate lines, as they are being scanned, have their addresses incremented by a number corresponding to half the scanning lines (262 for the NTSC system), so that alternate sequentially scanned lines will be stored in the memory as addresses corresponding to interlaced reproduction. The address generation is synchronized with movement of the film and the generation of address signals can be either direct or modified to permit reproduction in slow-motion or accelerated motion; the scanning can be direct or modified to compensate for distortion of film exposed through anamorphic lenses to reconstitute signals stored for undistorted presentation although these signals may cover only portions of possible addresses. The memory is read with a half-scanning frame delay so that a complete film frame is stored before the first half-frame is read out.

The present invention relates to the conversion of images on motion picture 
film to television image signals, and more particularly to a method and 
system for optically scanning motion picture film and then deriving 
television (TV) signals in which the film is continuously scanned without 
skips for interlacing. 
Various types of systems and method to scan motion picture film to develop 
TV image signals have been proposed. In some of those systems, the films 
are continuously moved. The TV signals which are derived, and which must 
conform to standards set by governmental regulatory authorities, include 
line and frame flyback signals. It is customary to scan each image twice, 
once with odd-numbered lines, and the second time with even-numbered 
lines, and to interlace the lines as they are being reproduced. 
Accordingly, TV frame scanning systems have been proposed in which the 
scanning beam is split into two components so that, in spite of continuous 
movement of the motion picture film, double scanning can be obtained, that 
is, scanning by two lines. Another type of motion picture film scanning 
system has been suggested in which a movable mirror is provided which, for 
each half image, has one of two alternate positions. Due to the different 
treatment of the half images or half frames--be it by separate beams or 
differently positioned mirror surfaces--some disturbances are noticeable 
at times which appear in the form of flicker. 
Film scanning devices have been proposed to avoid the flicker problem in 
which the film frames are scanned, line for line, without skipping any 
lines, recording the signals and reading the thus recorded signals in 
accordance with TV transmission standards. 
The Invention 
It is an object to improve the scanning of motion picture films to derive 
TV signals, to simplify the apparatus, and, particularly, to avoid the 
necessity of complex optical systems; and to arrive at a system and method 
which is versatile, so that films of various formats can be scanned, and 
the resulting image matched to the film, and in which films can be scanned 
and reproduced at a different reproduction rate to give the effect of 
speeded-up or slow-motion film. 
Briefly, the film is moved continuously. The frame is scanned, line by 
line, and scanned signals are derived. The scanning rate is high and 
predetermined; it is independent of film motion speed. The derived signals 
are stored in a memory. The lines of the film frame, as they are being 
scanned, are assigned individual line addresses, and the signals are 
stored in the memory at predetermined address locations. The data in the 
memory are then read out in accordance with TV scanning standards. 
Preferably, the line addresses for the signals to be stored in the memory 
are determined as a function of the film position with respect to the 
scanning beam derived, for example, from the film transport mechanism 
which is coupled to a signal transducer so that film movement and storage 
in respective addresses are synchronized. Film frame position can be 
determined, for example, by deriving a signal synchronized with an edge of 
the sprocket holes in the film. 
In accordance with a preferred feature of the invention, the film images 
are read out with a one-half frame phase shift or read-out time shift, so 
that the read-out from the memory is one-half frame behind recording. 
In accordance with a feature of the invention, the duration of scanning of 
any line is held fixed or constant, while the line sequence frequency upon 
scanning is matched to the respective film format so that, for example, 
Cinemascope films can be suitably reproduced. 
The film transport, in accordance with an advantageous feature of the 
invention, is so controlled that one film frame is completely scanned 
before the read-out of the first half-image from the storage or memory has 
been terminated. As a result, one complete TV image is placed in the 
memory; this prevents formation of a TV frame which is a composite of two 
sequential scenes if the subject matter on the film changes dramatically 
between succeeding frames. 
Various types of sensors can be used in the system for scanning, preferably 
linear optical sensors.

The constructions of the individual elements illustrated in FIGS. 1 and 2 
are well known in the art of motion picture-TV image signal conversion, 
and only so much of the system is illustrated as is necessary for an 
understanding of the invention. 
The film 1 (FIG. 1) to be scanned is delivered from a supply spool 2, 
guided over guide roller 3, a sprocket roller 4, the film window 5, a 
capstan 6, a further guide roller 7, and then wound up on a take-up reel 
8. The film speed is determined by the rotary speed of capstan 6. Capstan 
6 is driven by a capstan motor 9. The various apparatus necessary to drive 
take-up reel 8, pay-out reel 2, and the like, have not been shown; control 
of the speed of reels 2 and 8 and their drive can be done in accordance 
with any well-known system corresponding to the pull-down speed determined 
by the capstan 6 pulling the film in front of window 5. 
A projection lamp 10 associated with an optical system 11, of which only a 
single condenser lens is shown for simplicity, illuminates the film in 
window 5. The light output is passed through an optical system 12, of 
which only an objective is shown, which focusses the film on an optical 
sensor or transducer 13. Photo transducer 13 can be any well-known 
scanning apparatus. The present invention is independent of whether the 
film is a black-and-white (B/W) film, or color film; likewise, the 
invention is indepent of whether the transmission is to be for B/W TV 
reception or color reception. In case of color reception, three 
transducers similar to transducer 13 are preferably used on which the 
light is projected in accordance with a well-known color splitting 
arrangement. The output signals of the photoelectric transducer 13, or of 
the group of transducers 13, are amplified, corrected in accordance with 
well-known correction factors in correction networks as known in TV 
technology in a video processor 14 and then transformed into digital 
signals in the analog-digital (A/D) converter 15. Transposing the images 
into digital signals has the advantage of greatly simplified storage, 
since digital signals can be readily stored without loss in quality. The 
output of A/D converter 15 is connected to a memory 16. Memory 16 has a 
capacity sufficient to store the contents of an entire TV frame, including 
color information, if necessary. The digital TV signals are read out from 
memory 16 in accordance with TV reproduction standards--as will 
appear--then converted in a D/A converter 17 into analog signals and are 
available as standard video signals at terminal 18 of FIG. 1. 
The line-by-line scanning of the film frames, that is, the control of the 
photo transducer 13 (or transducers 13, if color signals are desired) is 
controlled by a scanning clock source 19, which will be described in 
connection with FIG. 2. 
The address which corresponds to the position of the respective line within 
an image frame of the film is derived by obtaining pulses from the 
sprocket 4 which are associated with the upper or lower edge of any one of 
the film frames; and by deriving pulses upon rotation of capstan 6 which 
are used to step a counter. The sprocket 4 is connected to a counter disk 
20; the capstan 6 is connected to a counter disk 21. Disk 20, 21 are 
formed with circumferential markers which subdivide the disk into angular 
regions which can be sensed or scanned by a respective transducer 22, 23 
associated with the respective disk 20,21. For example, transducer 22 will 
generate a pulse as soon as the film moves from one perforation to the 
next. These pulses from the transducers 22, 23 are connected to input 
terminals of a line counter 25, as will be described. 
The address in the memory 16 is determined by a control unit 31 which, in 
turn, is controlled by the line counter 25. Thus, since the line counter 
25 is controlled from the position of the film by the transducer 22 and 
the rotation of the capstan 6 by the transducer 23, the address of the 
respective signals to be stored in the memory 16 is directly derived from 
the respective position of the film within the film window 5. Counter 
pulses are derived from counter 25 which is set based on film 
perforations, that is, by the transducer 22 coupled to disk 20 and to 
sprocket 4; the count pulses themselves are derived from transducer 23 
which counts as the film moves past window 5 under control of movement of 
capstan 6. The transducer 22 is preferably so arranged with respect to 
disk 20 and the sprocket 4 that either the leading edge or the trailing 
edge of the perforations causes a respective control signal to be applied 
to the line counter 25. The first one of the lines scanned for any frame 
of the film is placed preferably into a predetermined initial address, the 
position may depend on the film format. Film frame indicia can also be 
scanned optically to obtain address coding pulses. 
The number of pulses which transducer 23 coupled to disk 21 and hence to 
capstan 6 will provide depends on the number of lines of the TV standard 
employed; for the standard, this would be 625 lines; for the NTSC 
standard, 525 lines. These are the numbers of lines during which the film 
is moved by one film or image frame. In normal operation, switches 26, 27 
are in their lower position, as shown in FIG. 1, so that the pulses are 
directly applied to the counter 25 until a next frame break pulse is 
sensed. The counter state which obtains during the scanning of a line 
forms the address of the respective line. To so arrange the memory address 
in memory 16 that read-out can be obtained with interlace, that is 
alternately line skipped signals systems under continuous read-out 
conditions, the address is incremented for each second line by the number 
311 for the (625 line) system, or by the number 262 for the NTSC 
system. An electronic transfer switch 28 controls change-over of the 
address by respectively adding the fixed number of 312, or 262, 
respectively--depending on system--for alternate lines. This number is 
stored in a fixed number memory 30, the switch 28 being controlled to 
alternate operation by a divide-by-two counter 29. Other systems can be 
used to associate the respective addresses in the memory 16 with proper 
sequential read-out, although the lines themselves are not to be 
reproduced in the order that the line control signals are derived. For 
example, a different arrangement can be had with respect to memory 16 
which may include reading the signals of the scanned lines sequentially in 
the memory and controlling the read-out by skipping alternate line 
addresses and then returning to then read out the previously skipped 
lines. The address of recording is controlled by a memory address control 
unit 31. Unit 31 receives a fixed address over an AND-gate 32 when a 
certain line, as determined by the scanning clock unit 19, is to be 
started. 
Capstan motor 9 is controlled by a motor control unit 33. Motor control 
unit 33 receives film frame separating pulses and line count pulses from 
the transducers 22, 23 respectively, and additionally horizontal and video 
synchronizing pulses. The motor control unit 33 additionally has a control 
voltage 34 applied thereto. Motor control unit 33 so controls the speed of 
the capstan motor 9 that, upon reproduction at standard speed, the film is 
moved synchronously with the TV clock or synchronization signals. Such 
circuits are well known with respect to film scanning systems as well as 
with respect to video tape recording apparatus, and any suitable one of 
these systems may be used. A specific case, and a specific modification 
will be explained in connection with FIG. 3. It is possible to operate 
motor 9 at a speed other than the standard speed in order to obtain slow 
motion or speeded-up motion of the images on the film. The control voltage 
34 supplies such additional control signals. 
No image information is transmitted during the vertical retrace of the TV 
signal. Thus, the image content is distributed not entirely over 625 ( 
system) lines, but somewhat less, for example to about 590 lines under 
that system, which would correspond to about 500 lines under the NTSC 
system. Consequently, and since the film moves continuously, roughly the 
same percentage of the film is not transmitted. Since standard motion 
picture film has a frame bar, that is, a space or break line between 
sequential frames of the film which, however, normally does not correspond 
to the portion of the vertical retrace, line frequency upon scanning must 
be changed in dependence on the width of the frame bar, or separating 
break line. For example, if upon scanning in accordance with the European 
system, the width of the film separating break line is more than 8% of 
the overall height of a frame, scanning with somewhat greater frequency is 
necessary. These differences are relatively small in 16 mm as well as in 
35 mm film. It is sufficient if the repetition frequency is changed, 
whereas the time during which a line is scanned is held constant. Upon 
only slight increase of the line repetition frequency, only the horizontal 
scanning frequency becomes smaller whereas the active line repetition rate 
remains. 
FIG. 2 illustrates a circuit which can be used to obtain the scanning 
repetition frequency which is different from the line frequency of the TV 
system. The circuit of FIG. 2 is used in accordance with the circuit of 
FIG. 1 and corresponds to element 19 of FIG. 1. Basically, a controlled 
oscillator operating at a frequency of several megahertz is used to obtain 
a divided frequency by means of a divider. A voltage controlled oscillator 
40 is preferred, and connected to a divider 41. The divider generates an 
auxiliary frequency. The division ratio of the divider can be programmed 
in accordance with film format. An auxiliary divider 42 is connected to 
the divider 41 which again divides the auxiliary frequency to obtain a 
derived frequency. The derived frequency and the auxiliary frequency are 
both connected to the inputs of an AND-gate 43. Upon suitable arrangement 
of the division ratio of divider 42, the output of AND-gate 43 will have 
pulses appear thereat which have a repetition rate different from the 
auxiliary frequency. The pulses are compared in a phase comparator 44 with 
the output of a second voltage controlled oscillator 45. The frequency of 
the second voltage controlled oscillator (VCO) 45 thus will be the average 
value of the frequency of the pulses from AND-gate 43. A further divider 
46 then derives a further signal, the frequency of which is phase-compared 
in a phase comparator 47 with pulses at horizontal frequency and connected 
as a control signal to the VCO 40. The phase comparator 47 operates at the 
horizontal frequency. Consequently, oscillator 40 is controlled to 
oscillate at a frequency which is a multiple of the horizontal frequency 
and which differs in predetermined manner from the horizontal frequency. 
Pulses can thus be obtained from the first divider 41 which have a 
predetermined relationship to the horizontal frequency. The particular 
relationship itself is determined by a program connected to a control 
terminal P, as will appear. The output from divider 41 is a signal H', 
that is, a signal which differs from the horizontal frequency, and applied 
to transducer 13 as well as to AND-gate 32 as shown in FIG. 1. 
TV scanning of motion picture film must be versatile and also suitable to 
scan film which does not have the normal vertical-to-horizontal 
relationship of approximately 3:4. It must also be available to scan films 
in which the recording is optically artificially distorted, to be then 
compensated upon projection by a similar re-distortion, compensation 
optical system. Cinemascope films are a typical example. The present 
invention is suitable to scan Cinemascope films which, for a complete 
understanding, will be described briefly. 
The proportional relationship of the length of the base and the height of 
standard film formats, that is, 16 mm and 35 mm standard film, is 
approximately that of a TV screen; this format has a ratio of about 3:4. 
In Cinemascope film, however, the relationship between width of the 
projected image and height is about twice as great. Cinemascope film, 
however, uses the standard 35 mm film. Upon exposure or recording, an 
anamorphic objective is used which compresses the width of the scene with 
respect to the height by about half. Upon projection of such films, this 
distortion is compensated by a projection objective associated with the 
projector which includes anamorphic optics. Such an anamorphic objective 
or optical arrangement can be saved when a Cinesmascope film is to be 
represented in television images by suitable adjustment of the deflection 
amplitudes of the TV scanning system. The reproduction on the TV screen 
should be without distortion; yet, the format of the TV tube cannot be 
changed and will retain its relationship of height to width of about 3:4. 
This means that the film can be scanned in such a manner that either the 
width is completely retained and the Cinesmascope image will have only 
half of the height of the tube; or, alternatively, the height can be 
properly reproduced and strips of the scene to be shown at the left and at 
the right are cut away, that is, are not transmitted at all. In actual 
practice, it is customary to select a compromise by introducing dark 
strips at the upper and lower edge of the image which should be of a width 
so as not to be disturbing to the viewer, while suppressing at the right 
and left side only those portions of the image which may be considered of 
lesser importance. 
The scanning arrangement permits a simple way of so reproducing 
Cinesmascope film without using an anamorphic lens while scanning the full 
width of the image. This is achieved by so arranging the addresses in 
which the signals are stored upon scanning that, when the signals are read 
out from the memory, the image to be reproduced will be reduced by half 
with respect to the height of the TV screen. Switches 26, 27 (FIG. 1), 
when placed in their upper position, provide a division by two; 
consequently, the line counter will receive only every other count pulse 
and only every other line which is scanned receives a new address. The 
content of two lines is thus recorded in the same address in the memory. 
Consequently, the image content of the overall frame is reduced to half 
the numbers of lines for reproduction of the scene on the TV screen. A 
gate 35 is provided connected to the SET input of the line counter so 
that, upon start of an image, the first line is recorded at that address 
in the memory which is associated with the first line of the TV image, as 
described in connection with the application of frame separating pulses 
and their use in the system of FIG. 1. The gate 35 will have an address 
applied thereto which depends on the format of the film which is being 
scanned. If Cinemascope film is to be scanned, the first image line can be 
recorded, for example, at the line 100 of the TV screen (for a 625-line 
system; for example at line 90 in the NTSC system); if the scanning is to 
be done from a normal 35 mm film, or 16 mm film, for example, the gate 35 
will have a 0 or a 1 applied thereto. 
Standard 16 mm film has one perforation for each frame. Pulses generated in 
the transducer 22, derived from the sprocket 4 and the transducer disk 20, 
can thus be used directly as the SET pulses for the counter 25. Switches 
36, 37 will then be in their lower position, as shown in FIG. 1. 35 mm 
film has four perforations for each frame and thus a divide-by-four 
counter 38 is interposed between the output from transducer 22 and the SET 
S input to the counter 25. Switches 36, 37 thus permit versatility in use 
of the system and enable quick change-over from one film format to 
another. Changing switches to the upper position so that the 
divide-by-four counter 38 is effective introduces, however, an ambiguity 
since there is no unambiguous association between the pulses derived from 
the photoelectric transducer 22 and the frame separation between adjacent 
frames of the film. To provide for such unambiguous association, the 
address of the line counter 25 is movable in increments of a quarter of 
the height of a frame, under manual control, not shown, in order to 
synchronize the output from the transducer 22, divided by four, and the 
count start of the line counter 25. Moving the line counter 25 for 
synchronization of the output pulses from transducer 22 so that they will 
be positively associated with the edge of a frame may have to be repeated 
several times until the line counter count state and the edge of the film 
frame are coincident. 
Scanning of Cinemascope film is schematically illustrated in FIG. 3. View 
(a) of FIG. 3 shows a circle recorded on a film strip in which the lateral 
sides are compressed. The film, shown at the left, is entirely scanned; 
the image content is compressed about half of the image height, however, 
as shown on the reproduction copy at the right of view (a), where the 
video image is illustrated in the horizontally lined portion. The 
inclined, cross-hatched portion will appear on the video reproduction as 
black strips at the top and bottom of the scene being reproduced. 
The vertical resolution of the TV screen can be better utilized by so 
scanning Cinemascope films that the right and left portions of the screen 
contain only a part of the scene being reproduced, the remainder being 
suppressed or lost. Accordingly, the reproduction of the film scene is 
projected on the photoelectric transducer 13 to an enlarged scale. This 
can readily be achieved by changing the objective 12 (FIG. 1) or changing 
the zoom focal length thereof. As illustrated in view (b) of FIG. 3, the 
central portion of the film frame is scanned completely; the entire height 
of the frame is scanned. The black strips at the top and bottom of the TV 
image will be narrower than in the illustration of view (a), although the 
portions of the film frame which are indicated in broken lines in view (b) 
are not transmitted. This results in a somewhat enlarged and more pleasing 
overall reproduction; it requires, in addition to a change in the focal 
length of the optical system 12--by exchange of the lens, for example, or 
other arrangement--further a change of the line repetition frequency. This 
requires change of the scanning clock unit 19. The line repetition 
frequency will then be about 10 kHz--for the European system. 
If the films are operated at normal standard "take" speed, it is desirable 
and preferred to synchronize the film transport with the TV clock or frame 
repetition rate. It is desirable to maintain a certain phase difference 
between the film scanning and read-out of the stored or memorized TV 
signals from the memory 16 so that a complete TV frame image can be 
associated with only a single motion picture frame. Since, however, in TV 
reproduction first a half-image or half-frame is transmitted, and 
thereafter an interlaced second half-frame, whereas, upon scanning in 
accordance with the system, the film is scanned sequentially, line for 
line, it is preferred and desirable to so select the phase difference that 
the last line of any one film frame is stored in the memory before the 
last line of the first half-frame is read out from the memory 16 (FIG. 1). 
Thus, a phase difference of a half-frame will result. This relationship is 
graphically illustrated in FIG. 4. 
FIG. 4 shows a timing diagram of storage and read-out. Graph (a) of FIG. 4 
shows continuous scanning of a 16 mm film in which any subdivision 
represents about 100 lines. Graph (b) illustrates, similarly, the TV frame 
signals which are read out from the memory. The first half frame of the TV 
signal, which includes the content of the film frame, commences only when 
the first film frame has been scanned only about to half its extent, so 
that the first film frame will be completely scanned when the last odd 
line of the TV frame is ready for read-out. The second TV half-frame, 
interlaced with the first, will then be read out from the memory while the 
second film frame commences to be scanned for storage in the memory. 
Graph (c) and graph (d) of FIG. 4 illustrate the same relationships for 35 
mm film. Due to the greater difference of relationships including the 
width of the separating lines between frames, it is necessary to consider 
the width of the frame separating line as well. 
Synchronization and interconnection of the film transport with the TV clock 
repetition rate is of importance, of course, only upon reproduction of 
films operating at normal speed. This synchronization is not absolutely 
necessary; the TV scene may then, however, be reproduced from two film 
frames, or portions of one and portions of another adjacent one. In normal 
film reproduction, this is not disturbing. 
It may be desirable to reproduce scenes stored on film at speed other than 
the taking speed. Upon reproduction of film below the normal film speed, 
the number of lines for each film frame being scanned will increase. 
Memory 16, however, stores only that number of lines which are associated 
with the specific TV scanning standard--for example 625 () or 525 
(NTSC). This can readily be derived from the arrangement in accordance 
with FIG. 1 by transferring the address at the beginning of a line being 
scanned by means of the AND-gate 32 (FIG. 1) to the memory recording 
control unit 31. The temporal relationship is illustrated in FIG. 5, in 
which in line a, various signals are schematically represented by the 
scanning intervals of the horizontal frequency. They are numbered 
consecutively from 51 to 55. If this film is to be read out under 
slow-motion conditions, then the count pulses, which are illustrated in 
graph (b), derived from the transducer 23 will have a lower frequency. 
This explanations starts from the consideration that each count pulse 
steps the line counter 25 by one digit, that is by 1, with the leading 
flank thereof. For purposes of this discussion, the interlace 
relationships and Cinemascope-distortion will not be considered, so that 
the principle can be more easily understood. Graph (c) shows that an 
address in the line counter will maintain the same value until it gets the 
next count pulse, to be then incremented by 1. The address--as described 
above in connection with the AND-gate 32--is now associated with the 
respective line, the scanning of which just has started. Line 51, thus, 
receives the address 211. Line 52, since at the beginning thereof the 
address 211 is still valid, will also receive the same address. Thus, line 
52 will be stored in the same storage positions of the memory 16 as line 
51. As a consequence, the content within memory 16 of line 51 will be 
erased in the customarily used memories and replaced by the content of 
line 52. Line 53 receives address 212; line 54 receives the address 213, 
but line 55 will also receive the address 213 which, again, means that 
line 54 will not be available for read-out since it will have been erased 
by line 55, and therefore effectively is not being stored. Since, as a 
consequence, the image content of various lines is not used or evaluated, 
a vertical image distortion will result. This vertical image distortion is 
very slight, however, and changes from line to line and, as has been found 
in actual experience, is not disturbing to the viewer. 
The converse relationship may obtain if, rather than slowmotion, a 
speeded-up or accelerated-motion reproduction is desired. FIG. 6 
illustrates the relationship upon scanning of films with speeds which are 
above normal taking speed. The pulses derived from the transducer 23 (FIG. 
1) will now have a repetition rate or frequency which is greater than the 
line repetition frequency, as clearly seen in FIG. 6, graph (b). 
Correspondingly, the time duration of the respectively valid address will 
be reduced, as seen in graph (c) of FIG. 6. The line 61, graph (a) of FIG. 
6, receives the address 101, which is valid at the beginning of this line. 
Correspondingly, line 62 receives the address 103, line 63 the address 
105, line 64 address 107, and line 65 address 109. The signals of these 
lines are then recorded in the respective memory positions. corresponding 
to the addresses of the lines as given. The memory positions corresponding 
to the line addresses 102, 104, 106, 1-8, 110 initially are free or 
unoccupied so that, upon reproduction, the read-out of those lines 102, 
104, 106, 108, 110 will not result in video signals. To avoid this 
disadvantage, various possibilities present themselves: For example, when 
reading out the signals from the memory, the content of any one line can 
be read twice if a subsequent line has no video signal stored therein. 
This solution decreases the resolution, however. Another possibility is to 
supplement the missing or blank lines by so controlling the transport 
speed of the film that the subsequent film frame will fill the blank 
memory positions of the memory 16, that is, where nothing was stored in 
prior storage. This can readily be obtained by so arranging, respectively, 
the film transport speed with respect to normal scanning speed, that the 
film speed does not differ by a whole number multiple from normal film 
speed. In some, and undesirable situations, it may be necessary to use 
more than two film frames in order to build a single composite TV video 
frame. By suitable synchronization circuits, which synchronize the 
movement of the drive capstan, that is, by applying suitable control 
signals to terminal 34 of the motor control unit 33 (FIG. 1), it is 
possible to so arrange the film transport speed, in which the composition 
of a complete TV image would take too long, that such particular speeds 
are prohibited. Such prohibited speeds, for example, are whole number 
multiples of normal film speed. 
It is entirely possible to combine the described systems and methods, for 
example such that, if for some reason scanning of a film where exactly 
double standard speed is desired, the blank lines will receive signals 
corresponding to the next preceding lines although, then, the resolution 
of the image being shown is less. When such a line is to be reproduced, 
that is, when it is found that the addresses being read out contain no 
data information, the previously read data information is merely 
duplicated from the previously stored information which, as is customary, 
will be retained in the memory until replaced by new data. While this will 
fill the TV image screen without blank interlaces, the overall quality of 
reproduction, particularly regarding resolution, will not be as good as 
when the recording scanning rate, as the film is being moved, does not 
correspond to normal film speed, multiplied by a whole number. 
Various changes and modifications may be made, and any one of the features 
described may be used with any of the others, within the scope of the 
inventive concept.