DEVELOPMENT OBJECTIVE AN ADVANCED TILT TOP LIGHT TABLE

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B04747A001400030018-5
• Release Decision: RIFPUB
• Original Classification: K
• Document Page Count: 4
• Document Creation Date: December 28, 2016
• Document Release Date: April 19, 2001
• Sequence Number: 18
• Publication Date: January 29, 1964
• Content Type: REQ

-approved For Release 2001/05/11 : CIA-RDP78EIQ4747AO01400030018-5
29 January 1964
DEVELOPMENT OBJECTIVE
AN ADVANCED TILT TOP LIGHT TABLE
1. .INTRODUCTION. '
These development objectives describe the requirements to be met in
the designing of an Advanced Tilt Top Light Table. This table is intended
as a replacement for contemporary tables which tend to be-awkward and uncom-
fortable to use. They provide inadequate light and, in most instances,
require the operator to adjust to the limitations of the table rather than
adjusting the table to the 'operator.
2. CONCEPT.
This table is intended to provide ease of viewing, increased illumin-
ation, easy loading and a. superior film transport system. It is to be as
light, compact and simple in mechanical design as is possible within the
parameters imposed by the specific requ.irepents stated in these objectives.
3. GENERAL DESCRIPTION.
This table shall provide a 11" by 18" illuminated area for use in view-
ing single rolls of 92", 5" or 70mm film, or dual rolls of either 5" or 70mm
film, concurrently. The light table in tilted configuration will normally
be positioned facing the operator on the front or forward edge of a low,
fixed or elevating table. The viewing surface will normally be tilted about
the center of the shorter axis of the light box; however, the table may be
used in a horizontal position or tilted about the long axis of the table.
4. REQUIREMENTS.
4.1. Illumination System
4.1.1. Intensity.
4.1.1.1. Range. The illumination system must provide at least 1500
foot lamberts,/(measured at the illumination surface) with 1800 foot lam-
berts a definite design goal. This illumination shall not vary by more than
10% between any two points within the entire illuminated surface area.
4.1.1.2. Variability. The illumination intensity shall be continu-
ously variable throughout a range of from 15% to 100% of full intensity with-
out evidence of "flicker."
4.1.2. Heat.. The light table must be able to be operated continuously
at maximum intensity over a 24 hour per:iod,in a room with an 80OF ambient
temperature, without exceeding 1100 on any external surface.
DECLASS REVIEW BY NIMA / DoD
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4.1.3. Diffuser. An opal glass or similar diffuser shall be located
~..' between the glass top and the light source.
4.1.4. Shades. Adjustable shades must be provided to block out all
of the illuminated surface not actually covered by the film. Each of these
shades must be located beneath the surface glass, mounted along the long
dimension of the unit and extendable ac;^oss the short dimension. This
extensibility must be continuously variable between a minimum extension of
(0) zero inches and a maximum extension of 9 inches. These shades must not
encroach upon the illuminated viewing area when retracted and, in addition,
must be lockable in any extended or retracted position.
4.2. External, Configuration.
4.2.1. Size. The entire unit shall not exceed 32" in length and 16"
in width. Width is exclusive of crank handles. The overall height of the
table shall not exceed 9" when. in the horizontal position. This is the
height excluding the film spools.
4.2.2. Weight. The unit must be as light as possible commensurate
with that weight which is necessary to maintain good stability and to ba
l-
.
ance the table in any of its tilted positions.
.4.3. Spool Loading and Holding Mechanism.
4.3.1. Loading Mechanism. A loading mechanism must be provided for
the fast loading and unloading of single spools of 92", 5" and 70mm film or
dual rolls of either 5" or 70mm. These rolls will range up to and including
500 feet in capacity. The loading system must be both quick and easy to
operate and at the same time positive in'ation; i.e.-it must not drop the
heaviest full spool (92", 500 ft.) no matter what the degree of tilt of the
table or how fast or hard the film is cranked. A drop-in film loading device
is one possibility
4.3.2. Holding Mechanism. The holding mechanism which engages and
secures the spool must be designed for easy one hand operation so that the
film can be held in one hand while the holding mechanism is activated with
the other. A positive but quick release lock must be provided on this secur-
ing device.
.4.4. Film Transport.
4.4.1. General. The film transport system must be unique in that it
shall permit bi-directional film motion controllable from either end, i.e.,
.it will permit both winding and unwinding with the same crank atone end of
the table. This transport system may be either mechanical or electro-
mechanical; however, basic simplicity of design and complete reliability
are mandatory; consequently.a purely mechanical system is more desirable.
4.4.2. Film Capacity. The film transport system must be able to
accommodate either single rolls of 92", 5" or 70mm wide film on either
partially or fully loaded spools of up to and including 500 feet ca
acit
p
y.
In addition, provision must be made for handling dual rolls of either 5" or
.70mm film simultaneously. These rolls should be mounted side by side with
a supporting post in between.
4.4.3. Film Direction. Film spools shall. be located at the ends of
the long dimension of the viewing area., with the film or films transported
along and parallel to the long axis of the light table. When dual rolls
are used, the filpn strips will travel parallel to each other and to the
long axis of the table, with.a minimum of separation between strips.
.4.4.4. Rollers. Rollers must be designed so that film can be trans-
ported with either emulsion up or emulsion down without scratching either
the emulsion or the b~s,e of the film. The rollers must be either segmented
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or some alternative system provided so that when dual rolls of film are
~.~ used, alternate rolls of film can be wound in opposite directri.ons concur-
rently or one of the dual rolls translated while the other roll remains
stationary.
4.4.5. Film Tension. The film transport mechanism must maintain a
light, constant, even tension on the film or films -- just enough tension
to keep the film flat and in contact with the plate glass surface when the
film is not being transported.. This tension should be automatically reduced
(eased) when the film is transported.
4.4.6. Film Drive. The film drive must provide a means of winding and
unwinding single rolls of 92, 5" or 70mm wide film or dual rolls of either
5" or 70mm film. The drive must provide the ability to wind one of the dual
rolls while unwinding the alternate roil or, for instance, permit one film
roll to remain stationary while the other roll is translated. The drive
control may be a hand crank or electric switch; however, if an electric
control is used, it must permit the same degree of control sensitivity as
a hand crank.. If an electric drive is proposed, an additional high or
"slew' speed must be provided.. If a mechanical system is proposed,.a two
speed mechanical gear shift or electrical slew with-'a mechanical hand crank
override will be required. In all cases, reliability of operation is manda-
tory. Each individual hand crank must provide very smooth winding and
unwinding of film from either its own spool or the spool at the other end
(long axis) of the table. The drive must be a: low friction system incorpor-
ating inertia-damping and antiba,cklash 'control. The.efficiency, reliability,
and ease of operation of this drive system is the most important single con-
sideration in these development objectives.
4.5. Tilt Mechanism.
4.5.1. Amount and Direction of Tilt. The tilt mechanism must permit
the table to tilt about its center from the horizontal to a position of 150
measured from the vertical when rotates. about the short axis. This tilt,
beck~.Use of the 9". overall height requirement (when in horizontal mode), may
require a movable pivot point and assumes that the base is located at the
edge of the table to permit the film spools and transport mechanism to
extend out into space and clear the supporting surface. In addition, the
light table should be able to tilt about its center, from the horizontal to
45 from the vertical when rotated about its long axis. These motions must
be smooth, positive and continuously variable. Ball joints, while providing
the required flexibility of motion, have not proved successful in the past.
4.5.2. Tilt Lock Mechanism. A positive mechanism must be provided to
lock the light table in all possible tilted and horizontal positions. This
lock must be activated and deactivated with only a, minimum of force and it
must not lose its positive locking characteristics because of wear under
continuous hard usage.
4.5.3. Electrical Wiring. All electrical wiring between the base and
the light table must be carried internally or positioned where it can not
be twisted or broken off. This wiring shall not interfere in any manner
with the tilting motion of the table.
4.5.4. Balance. The table must be completely stable and remain prop-
erly balanced throughout all the possible tilt.positions,'even with dual
500 foot rolls of 5" film on one end and empty spools on the other.
.4.6. Miscellaneous.
4.6.1. .Construction. Construction shall meet.?the highest commercial
standards.
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4.6.2. Shock Hazard. The unit must be grounded and be free of all
shock hazard.
4.6.3. Warning Light. A warning light must be provided to show when
the unit is on even if the table light intensity is turned completely down.
4+.6.4. Controls. All necessary controls must be provided in locations
readily accessible to the operator regardless of the degree of table tilt.
Human engineering factors must be thoroughly considered in the design and
placement of all necessary controls.
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