AN AMERICAN NATIONAL STANDARD IEEE STANDARD DEFINITIONS OF TERMS ON FACSIMILE

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• Document Number (FOIA) /ESDN (CREST): CIA-RDP80B00829A001100050002-0
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• Document Page Count: 12
• Document Creation Date: December 9, 2016
• Document Release Date: August 23, 2001
• Sequence Number: 2
• Content Type: REGULATION

Ap~xrovedF~r Rel~~se 240'~/Q91#~5. ~tA~?flPB;~B~?~~?'~i40Q10`Qtl~{TQ~T?-Q
An American National Standard
IEE'E' Standard
definitions of Terms
on Facsimile
 Approved For Release 2001/09/05 :CIA-RDP80B00829A001100050002-0
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 Approved For Release 200~1~,,~Q~g~~00829A001100050002-0
Facsimile Test Chart
The pattern number given in the following
descriplion may be identified from Figure 1.
This chart is designed far scanning in either
direction, horizontally ac:rosa the page.
IEEE Std 167-1966, Teat Procedure for Fac-
simile was based on previous issues of the
IEEE Test Chart.
Patterns 1 and 2. 96 linos per inch (3.78 lines
per millimeter) consistinig of 48 dark and 98
light lines, substantially equal in width. In
pattern 1, the black corresponds approximate-
ly to step 2 and gray to step 7 of pattern 8. In
pattern 2, white represents paper white and
gray to approximately step 11. These patterns
are intended for generating low-modulation
high-frequency signals at both ends of the
density scale- useful for testing modulation
characteristics at edges of band in a frequency
shift system.
Patterns 3, 4, and 5. Vertical bar patterns at
10, 50, and 96 lines per inch (0.394, 1.97, and
3.78 lines per millimeter) of substantially
equal width -useful for square-wave testing
at several keying frequencies.
Pattern 8. A continuous density wedge de-
signed so tltat at equal intervals of distance
across the page, the variation in reflectance
will be roughly equally perceptible to the eye.
Reading left-to-right across the page, the rela-
tive reflection density values at the heavy dots
are approximately as shown in Table 1. Pat-
tern 6 is useful for cases where intermediate
reflection densities are needed between the
steps in Patterns 7 and 8.
Table 1
Pattern 6 Density Values
Patterns 7 and 8. Reversed step tablets of 15
steps with reflection densities corresponding
the approximately equal perceptibility modi-
fi,?ti to provide smaller ]ow density in-
crement. Consistent with conventional prac-
tice, paper white is understood to be equal to
0.00 in density (approximately 0.07 on an ab-
solute scale. For patterns' and 8 the relative
refection densities are shown in Tables 2 and
3 respectiveh
'1'hesE patterns will assist in appraising
gradient and absolute scale. They are useful
for chi?ckiug half-tone characteristics. Rever-
sed sequences are used since the dynamic half-
tone characteristics may differ for a rising
density or a falling density scale.
~ L_~~ fZ~1 Cam?
---1 ,~~_>o ->~ _~
IEEE StA t67A 1915
Fig 1
Pattern Anaagement
Pattern 13. Truncated fan-type multiple-line
test pattern.Calibrated in lines per inch-use-
tul for checking multiple-line definition along
scanning line, envelope delay distortion, and
ringing.
Patterns 14A and 14B. NBS type Microcopy
Resolution test pattern. Numerals indicate
the number of cycles (one black plus one white
line) per millimeter (that is, line pairs)-useful
in checking hiKh definition systems.
Pattern 16. Photograph with detail in high-
light and shadow. The limiting densities of
the photograph approximate those of test pat-
terns 7 and B.
Pattern 18. Vertical gray steps with relative
reflection densities of approximately 0.95 and
0.27 -useful in testing rising and falling tran-
sient characteristics and level variations.
Pattern 18. Horizontal "V" pattern with 0.13
in (3.3 mm) openinK? Number of scanning line
crossings of both lines, multiplied by 7.7 will
equal number of lines per inch (multiply by
0.3 for number of lines per millimeter).
Pattern 19. "Fence" pattern with 0.01 in
(0.254 mm) lines 0.10 in (2.54 mm)
apart-useful for checking jitter and measur-
ing available line length.
Patterns 20 and 21. Halftone dot screens. Re-
produced in approximately 10, 50 and 90 per-
cent black, left to right and at 65 dots per inch
(2.56 dote per millimeter) at a 45? angle for
pattern 20, and t.20 dote per inch (4.72 dote
per millimeter) for pattern 21.
Pattern 22. Title and credit box. Three sizes
of Times Roman type font.
Patterns 23 and 24. Fiducial dote forming a 3,
4, 5 right triangle-useful for indicating the
presence of skew by comparing the hypote-
nuse of the two patterns.
Pattern 25. Type faces es indicated-useful
for checking readability.
Pattern 28. Extension lines to permit mea-
surement of available line and useful length of
copy.
Pattern 9. National Bureau of Standards
INBS1 tvpe repeatinK tri-bar resolution test
pattern. Twelve complete sets of three-line
patterns are repeated across the sheet. Alter- _
oats croups are of different line spacinK. Den-
sity values are shown in'Tahle 4. This pattern
is useful for checkinK definition.
Psttern 1.0. 1Zectangle with 45? diagonal
marks at ear.h corner -useful for checking in-
dex of cooperation, skew, and paper-teed er-
ror.
Patterns 11 and 17. White wedge on black
background and black wedge on white back-
ground, 0.07 in (1.76 mm) to zero -- useful for
checking single-line def-inition.
____"____GrouPA _.
Table 4
Patera 8 Density Values
Pattern l2. W. anrJ l.. E. s3urley type Pestre- __..___ ' ` ___ '
cue 3[ar pattern. Outer sire".e 50, second circle Linea per Inch 61.0 86.4 122 __ 173 244 345 406 284 203 142 102 71.1
100, artd third circle 200 lines per inch (1.97, LinexperMillimeter 2.40 3.90 4.80 6.81.I~y9~.,6g0 ]~3p.6 y~16.r0~ipg1~1.2 y.~7.99 5.59 4.02 2.80
3.94, and 7.87 Iines~gt,gji~i~tdr~Or Releas~?~?~~PYOt3~0~~.''tP~~~~~BLy~~U~UUU~UUU~hUisht.
('opyright 19 i 5 Institute of Electrical and Electronics Engineers, Inc.
Table 2
Pattern 7 llensity Test`
Density 0.01 0.03 0.06 O.10 0.26 0.36 0.46 0.60 0.72 0.89 1.07 1.22 1.43 1.64 1.80
Table 3
Pattern 8 Density Values?
 Approved For Release 2001/09/05 :CIA-RDP80B00829A001100050002-0
ANSI
C16.30-1972
IEEE
Std 168-1956
Reaffirmed 1971
An American National Standard
IEEE Standard
Definitions of Terms
on Facsimile
Approved July 11, 1972
The American National Standards Institute
Published by
INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS
345 East 47 Street, New York, N. Y. 1001?
Approved For Release 2001/09/05 :CIA-RDP80B00829A001100050002-0
 Approved For Release 2001/09/05 :CIA-RDP80B00829A001100050002-0
IEEE Standard
Definitions of Terms
on Facsi-mile
COMMITTEE PERSONNEL
Committee on Facsimile
}i. R. MCCONNELL, Chairman 1955
H. BURRHARD, Chairman 1953-1955
R. J. WISE, Chairman 1951-1953
D. FREZZOLINI, Vice-Chairman 1955
A. G. COOLEY, Vice-Chairman 1953-1955
H. BURKHARD, Vice-Chairman 1951-1953
H. F. Burkhard
M. F. Hodges
M. P. Rehm
J. Callahan
J. V. Hogan
H. C. Ressler
C. K. Clauer
B. H. Klyce
R. B. Shanck
A. G. Cooley
L. R. Lankes
G. S. Thompson
I. H. Franzel
S. A. Lawson
P. Turkeimer
D. Frezzolini
K. R. McConnell
R. J. Wise
J. H. Hackenberg
P. Mertz
K. Woloschak
F. Hester
K. W. Pfieger
C. J. Young
Standards Committee
1955-1956
W. R. Bennett
P. J. Herbst
K. R. McConnell
J. G. Brainerd
Hans Jaffe
H. R. Mimno
P. S. Carter
Henry Jasik
M. G. Morgan
P. S. Christaldi
A. G. Jensen
C. A. Morton
A. G. Clavier
J. L. Jones
H. L. Owens
J. E. Eiselein
J. G. Kreer, Jr.
P. A. Redhead
A. W. Friend
E. A. Laport
R. Serrell
L'. H. Graham
A. A. MacDonald
R. M. Showers
R. A. Hackbusch
Wayne Mason
H. R. Terhune
H. C. Hardy
D. E. Maxwell
J. E. Ward
D. E.-Harnett
W. T. Wintringham
Definitions Coordinator
M. W. BALDwIN, JR.
AM to FS Converter. See Transmitting Converter, Fac-
simile.
Available Line. The portion of the scanning line which
can be used specifically for Picture Signals.
Bandwidth, Facsimile. In a given Facsimile System, the
difference in cycles per second between the highest
and the lowest frequency components required for ade-
quate transmission of the Facsimile Signals.
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 Baseband. InA~paoried ~or~~~aa~e)200Ce0o~0 ad,ColA- RDP80Bg00om9tAr~ of t000o50 002 ~ stem in which the
transmission system, the lb?and of frequencies occupied material is used.
by the signal before it modulates the carrier (or Subcar-
rier) frequency to form the transmitted line or radio
signal.
Note: The signal in the Baseband is usually distin-
guished from the .line or radio signal by ranging over
distinctly lower frequencies, which at the lower end
relatively approach or may include do (zero frequency).
In the case of a Facsimile Signal before modulation on
a Subcarrier, the Baseband includes de.
Black Recording. In an amplitude-modulation system,
that form of Recording in which the maximum received
power corresponds to the maximum Density of the Rec-
ord Medium. In afrequency-modulation system, that
form of Recording in which the lowest received fre-
quency corresponds to the maxirntrm Density of the
Record Medium.
Black Signal. T'he signal at any poir7t in a Facsimile
System produced by the Scanning of a maximum Den-
sity area of the Subject Copy.
Black Transmission. In an amplitude-modulation sys-
tem, that form of transmission in which the maximum
transmitted power corresponds to the maximum Den-
sity of the Subject Copy. In afrequency-modulation sys-
tem, that form of transmission in which the lowest
transmitted frequency corresponds to the maximum
Density of the Subject Copy.
Carbon Pressure Recording. That type of Electrome-
chanical Recording %n which a pressure device acts upon
carbon paper to register upon the Record Sheet.
Carrier Beat. The undesirable heterodyne of signals
each synchronous with a different stable reference
oscillator causing a pattern in received copy. Where
one or more of the oscillators is fork controlled, this is
called Fork Beat.
Converter, Facsimile. A device which changes the type
of modulation.
Definition. Distinctness or clarity of detail or outline in
a Record Sheet, or other reproduction.
Delay Distortion. See Envelope Delay Distortion.
Delay Equalizer. A corrective network which is designed
to make the Phase .Delay or Envelope Delay of a circuit
or system substantially constant over a desired fre-
quency range.
Density (in Facsimile). A measure of the light-trans-
mitting or -reflecting properties of an area. !t is ex-
pressed by the common logarithm of the ratio of inci-
dent to transmitted or reflected light flux.
Note: There are many types of Density which will
usually have different numerical values for a given ma-
terial; e.g., Diffuse Density, Double Diffuse Density,
Specular Density. The relevant type of density depends
Direct Recording. That type of Recording in which a
visible record is produced, without subsequent process-
ing, in response to the received signals.
Drive Pattern. Density variation caused by periodic er-
rors in the position of the Recording Spot. When caused
by gears this is called Gear Pattern.
Drum Speed. The angular speed of the transmitter or
recorder drum.
Note: This speed is
ute.
measured in revolutions per min-
Dual Modulation. The process of modulating a common
carrier wave or Subcarrier by two different types of
modulation (e.g., ar'erplitude-and frequency-modulation)
each convei=ing separate information.
Echo. A wave which has been reflected at one or more
points with sufficient magnitude and time difference
to be perceived in some manner as a wave distinct from
that of the- main transmission.
Effective Band (in Facsimile). The frequency band of a
Facsimile Signal wave equal in width to that between
zero frequency anal Maximum Keying Frequency.
Note: The frequency band occupied in the trans-
mission medium will in general be greater than the
E,~'ective Band.
Electrochemical Recording. Recording by means of a
chemical reaction brought about b}= the passage of
signal-controlled current through the sensitized portion
of the Record Sheet.
Electrolytic Recording. "That type of electrochemical
recording in which the chemical change is made possible
b}= the presence of an electrolyte.
Electromechanical Recording. Recording by means of
asignal-actuated mechanical device.
Electronic Line Scanning. That method of Scanning
which provides motion of the Scanning Spot along the
scanning line by electronic means.
Electronic Raster Scanning. That method of Scanning
in which motion of the Scanning Spot in both dimen-
sions is accomplished by electronic means.
Electrostatic Recording. Recording by means of a signal-
controlled electrostatic field.
Electrothemmal Recording. That type of Recording
which is produced principally by signal-controlled ther-
mal action.
Elemental Area. Any segment of a Scanning Lint of the
Subject Copy the dimension of which along the line is
exactly equal to the Nominal Line Width.
Note: Elemental area is not necessarily the same as
the Scanning Spot..
3
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 End-of-Copy SignalA~psri~i~a~~r~d4~at~~~~gni~r~aQi~i4~5~~{D,d,,~~iOQtB~~Qp~~~QQ~OQ~~u9tment of the
the transmission of a complete Subject Copy. picture to a desired position in the direction of line
Envelope Delay. The time of propagation, between two
points, of the envelope of a wave.
Note: The Envelope Delay is measured by the slope
of the phase shift in cycles plotted against the frequency
in cycles per second. If the system distorts the envelope
the Envelope Delay at a specified frequency is defined
with reference to a modulated wave which occupies a
frequency bandwidth approaching zero.
Envelope Delay Distortion. That form of distortion
which occurs when the rate of change of phase shift
with frequency of a circuit or system is not constant
over the frequency range required for transmission.
Note: Envelope Delay Distortion is usually expressed
as one-half the difference in microseconds between the
maximum and minimum Envelope Delays existing be-
tween the two extremes of frequency defining the chan-
nel used.
Facsimile (in electrical communications). The process,
or the result of the process, by which fixed graphic ma-
terial including pictures or images is scanned and the
information converted into signal waves which are
used either locally or remotely to produce in record form
a likeness (Facsimile) of the Subject Copy.
Facsimile Signal (Picture Signal). A signal resulting
from the Scanning process.
Facsimile-Signal Level. The maximum Facsimile Signal
power or voltage (rms or dc) measured at any point in
a Facsimile System.
Note: It may be expressed in decibels with respect
to some standard value such as 1 milliwatt.
Facsimile System. An integrated assembly of the ele-
ments used for Facsimile.
Facsimile Transient. A damped oscillatory transient
occurring in the output of the system as a result of a
sudden change in input.
Facsimile Transmission. The transmission of Signal
Waves produced by the Scanning of fixed graphic ma-
terial, including pictures, for reproduction in record
form.
Flood Projection. The optical method of Scanning in
which the Subject Copy is flood-lighted and the Scanning
Spot is defined in the path of the reflected or transmitted
light.
Fork Beat. See Carrier Beat.
Frame (in Facsimile). A rectangular area, the width of
which is the Available Line and the length of which is
determined by the service requirements.
Framing. The adjustment of the picture to a desired
position in the direction of line progreGSioTi.
progression.
FS to AM Converter. See Receiving Converter, Facsimile.
GeAr Pattern. See Drive Pattern.
Grouping. Periodic error in the spacing of Recorded Lines.
Halftone Characteristic. Arelation between the Density
of the recorded copy and the Density of the Subject Copy.
Note: The term may also be used to relate the ampli-
tude of the Facsimile Signal to the Density of the Sub-
ject Copy or the record copy when only a portion of the
system is under consideration. In a frequency-modula-
tion system an appropriate parameter is to be used in-
stead of the amplitude.
Index of Cooperation, Scanning or Recording Line. In
rectilinear Scanning or Recording, the product of the to-
tal length of a scanning or recording line by the number
of scanning or recording lines per unit length.
Note 1: The International Index of Cooperation (di-
ametral index of cooperation) is based on drum diameter
and is defined by the International Radio Consultative
Committee (CCIR). It is 1/a times the Scanning Line
Index of Cooperation.
Note 2: For a scanner and recorder to be compatible
the Indices of Cooperation must be the same.
Ink Vapor Recording. That type of Recording in which
vaporized ink particles are directly deposited upon the ~,
Record Sheet.
Jitter (in Facsimile). Raggedness in the received copy
caused by erroneous displacement of Recorded Spots in
the direction of Scanning.
Kendall Effect. A spurious pattern or other distortion
in a facsimile record caused by unwanted modulation
products arising from the transmission of a carrier signal
and appearing in the form of a rectified Baseband that
interferes with the lower sideband of the carrier.
Note: This occurs principally when the single side-
band width is greater than half the Facsimile carrier
frequency.
Light Carrier Injection. The method of introducing the
carrier by periodic variation of the scanner light beam,
the average amplitude of which is varied by the Density
changes of the Subject Copy.
Magnetic Recording. Recording by means of a signal-
controlled magnetic field.
Maximum Keying Frequency (Fundamental Scanning
Frequency). The frequency in cycles per second numeri-
cally equal to the Spot Speed divided by twice the Scan-
ning Spot X Dimension.
Maximum M::u:ating Frequency. The highest Picture
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tem.
Note: The Maximum Modulating Frequency and the
Maximum Keying Frequency .are not necessarily equal.
Multipath. See Multipath Transmission.
Multipath Transmission (Multipath). The propagation
phenomenon which results in signals reaching the radio
receiving antenna by two or more paths.
Note: In Facsimile, Multipath causes Jitter.
Multiple Spot Scanning. The method in which Scanning
is carried on simultaneously by two or more Scanning
Spots, each one analyzing its fraction of the total
scanned r:rea of the :Subject Copy.
Noise. Any extraneous electrical disturbance tending
to interfere with the normal reception of a transmitted
signal.
Nominal Line Widtlh. The average separation between
centers of adjacent scanning or recording lines.
Overlap X. The amount by which the Recorded Spot X
Dimension exceeds that necessary to form a most nearly
constant Density line.
Note: This effect: arises in that type of equipment
which responds to a constant Density in the Subject
Copy by a succession of discrete Recorded Spots.
Overlap Y. The amount by which the Recorded Spot
Y Dimension exceeds the Nominal Line Width.
Phase Delay. In the transfer of a single frequency wave
from one point to another in a system, the time delay
of a part of.the wave identifying its phase.
Note: The Phase Delay is measured by the ratio of
the total phase shift in cycles to the frequency in cycles
per second.
Phase Distortion. See Phase-Frequency Distortion.
Phase-Frequency Distortion. Distortion due to lack of
direct proportionality of phase shift to frequency over
the frequency range required for transmission.
Note Y: Delay Distortion is a special case.
Note 2: This definition includes the case of a linear
phase-frequency relation with the zero frequency inter-
cept differing from an integral multiple of ~.
Phasing. The adjustment of picture position along the
scanning line.
Phasing Signal. A, signal used for adjustment
picture position along the scanning line.
is ure nver i p
the black and white shades of the Recorded Copy.
Picture Signal. See Facsimile Signal.
Ready-to-Receive Signal. A signal sent-back to the Fac-
simile Transmitter indicating that a Facsimile Receiver
is ready to accept the transmission.
Receiver, Facsimile. The apparatus employed to trans-
late the signal from the communications channel into
a Facsimile record of the Subject Copy.
Receiving Converter, Facsimile (FS to AM Converter).
A device which changes the type of modulation from
frequency shift to amplitude.
Record Medium. The physical medium on which the
Facsimile Recorder forms an image of the Subject Copy.
Record Sheet. The medium which is used to produce a
visible image of the Subject Copy in record form. The
Record Medium and the Record Sheet may be identical.
Recorded Spot. The image of the Recording Spot on the
Record Sheet.
Recorded Spot X Dimension. The effective Recorded
Spot dimension measured in the direction of the recorded
line.
Note Y: By effective dimension is meant the largest
center-to-center spacing between Recorded Spots which
gives minimum peak-to-peak variation of Density of the
recorded line.
Note Z: This term applies to that type of equipment
which responds to a constant Density in the Subject Copy
by a succession of discrete Recorded Spots.
Recorded Spot Y Dimension. The effective Recorded
Spot dimension measured perpendicularly to the record-
ed line.
Note: By effective dimension is meant the largest
center-to-center distance between recorded lines which
gives minimum peak-to-peak variation of Density across
the recorded lines.
Recorder, Facsimile. That part of the Facsimile Re-
ceiver which performs the final conversion of electrical
Picture Signal to an image of the Subject Copy on the
Record Medium.
Recording (in Facsimile). The process of converting the
electrical signal to an image on the Record Medium.
of the Note: See Direct Recording, Electrochemical Recording,
Photosensitive Recording. Recording by the exposure
of a photo-sensitlve surface to asignal-controlled light
beam or spot.
Picture Frequencies. The frequencies which result solely
from Scanning Subject Copy.
Note: This does not include frequencies which are
part of a modulated carrier signal.
Electrolytic Recording, Electromechanical Recording;
Electrostatic Recording, Electrochemmal Recording, Ink
Vapor Recording, Magnetic Recording, and Photosensi-
tive Recording.
Recording Spot (in Facsimile). The image area formed
at the Record Mediust~ by the Facsimile Recorder.
Reproduction Speed. The area of copy recorded per
unit time.
5
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Ringing. See Facsimile Transient.
Scanner. That part of the Facsimile Transmitter which
systematically translates the Densities of the Subject
Copy into signal-wave form.
Scanning (in Facsimile). The process of analyzing suc-
cessively the Densities of the Subject Copy according to
the elements of a predetermined pattern.
Note: The normal Scanning is from left to right and
top to bottom of the Subject Copy as when reading a
page of print. Reverse direction is from right to left
and top to bottom of the Subject Copy.
Scanning Line Frequency. See Stroke Speed.
Scanning Line Length. The total Iength of scanning line
is equal to the Spot Speed divided by the Scanning Line
Frequency.
Note: This is generally greater-than the length of the
Available Line.
Scanning Spot (in Facsimile). The area on the Subject
Copy viewed instantaneously by the pickup system of
the-Scanner.
Scanning Spot X Dimension. The effective scanning
spot dimension measured in the direction of the scan-
ning line on the Subject Copy.
Note: The numerical value of this will depend upon
the type of system used.
Scanning Spot Y Dimension. The effective scanning
spot dimension measured perpendicularly to the scan-
ning line on the Subject Copy.
Note: The numerical value of this will depend upon
the type of system used.
Signal Contrast (in Facsimile). The ratio expressed in
decibels between White Signal and Black Signal.
Signal Frequency Shift. In a frequency shift Facsimile
System, the numerical difference between the frequen-
cies corresponding to White Signal and Black Signal at
any point in the system.
Simple Scanning. Scanning of only one Scanning Spot
at a time during the Scanning process.
Skew (in Facsimile). The deviation of the received
Frame from rectangularity due to asynchronism be-
tween Scanner and Recorder. Skew is expressed numer-
ically as the tangent of the angle of this deviation.
Spot Projection. The optical method of Scanning or Re?
cording in which the Scanning or Recording spot is de-
fined in the path of the reflected or transmitted light.
Spot Speed. The speed of the Scanning or Recording
spot within the Available Line.
Note: This is generally measured on the Subject
Copy or on the Record Sheet.
CIA-RDP80B00829A001100050002-0
Stagger. Periodic error in the position of the Recorded
Spot alorig the recorded line.
Start Record Signal. A signal used for starting the proc-
ess of converting the electrical signal to an image on the
Record Sheet.
Start Signal. A signal which initiates the transfer of a
Facsimile equipment condition from standby to active.
Stop Record Signal. A signal used for stopping the
process of converting the electrical signal to an image
on the Record Sheet.
Stop Signal. A signal which initiates the transfer of a
Facsimile equipment condition from active to standby.
Stroke Speed (Scanning or Recording Line Frequency).
The number of times per minute, unless otherwise
stated, that a fixed line perpendicular to the direction
of Scanning is crossed in one direction by a Scanning or
Recording Spot.
Note: In most conventional mechanical systems this
is equivalent to Drum Speed. In systems in which the
Picture Signal is used while Scanning in both directions,
the Stroke Speed is twice the above figure.
Subcarrier. A carrier which is applied as a modulating
wave to modulate another carrier.
Subject Copy. The material in graphic form which is to
be transmitted for Facsimile reproduction.
Synchronizing (in Facsimile). The maintenance of pre-
determined speed relations between the Scanning Spot
and the Recording Spot within each scanning line.
Synchronizing Signal (in Facsimile). A signal used for
maintenance of predetermined speed relations between
the Scanning Spot and Recording Spot within each scan-
ning line.
Tailing (Hangover). The excessive prolongation of the
decay of the signal.
Transmitter, Facsimile. The apparatus employed to
translate the Subject Copy into signals suitable for de-
livery to the communication system.
Transmitting Converter, Facsimile (AM to FS Con-
verter). Adevice which changes the type of modulation
from amplitude to frequency shift.
Underlap X. The amount by which the center-to-center
spacing of the Recorded Spots exceeds the Recorded Spot
X Dimension.
Note: This effect arises in that type of equipment
which responds to a constant Density in the Subject
Copy by a succession of discrete Recorded Spots.
Underlap Y. The amount by which the Nominal Line
Width exceeds the Recorded Spot Y Dimension.
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STANDARDS DEPARTMENT
The Institute of Electrical and Electronics Engineers
345 East 47th Street
New York, N. Y. 10017
Place
Here
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To IEEE
Standards Department
,IEEE_Std 168-1956
30-1972
ANSI C16
.
Please advise me when new editions of
are issued.
Name_
Compan y
Address_
Approved For Release 2001/09/05 :CIA-RDP80B00829A001100050002-0
 Approved For Release 2001/09/05 :CIA-RDP80B00829A001100050002-0
Useful Line. See Available Line.
Vestigial Sideband. The transmitted portion of the
sideband which has been largely suppressed by a trans-
ducer having a gradual cut-off in the neighborhood of
the carrier frequency, the other sideband being trans-
mitted without much suppressio~l.
Vestigial Sideband Transmission. That method of
signal transmission in which one normal sideband and
the corresponding Vestigial Sideband are utilized.
White Recording. In an amplitude-modulation system,
that form of Recording in which the maximum received
power corresponds to the minimum Density of the Rec-
ord Medium. In afrequency-modulation system that
form of Recording in which the lowest received frequency
corresponds to the minimum Density of the Record
Medium.
White Signal. The signal at any point in a Facsimile
System produced by the Scanning of a minimum Den-
sity area of the Subject Copy.
White Transmission. In an amplitude-modulation sys-
tem, that form of transmission in which the maximum
transmitted power corresponds to the minimum Den-
sity of the Subject Copy. In afrequency-modulation sys-
tem, that form of transmission in which the lowest
transmitted frequency corresponds to the minimum
Density of the Subject Copy.
Approved For Release 2001/09/05 :,'CIA-RDP80B00829A001100050002-0