An Optical Fiber Cable System for HDTV Cameras
by Takashi Narimatsu * , Tatsuo Sekiguchi * and Hiroyuki Sekino *The content of programs for terrestrial digital broadcasting that started in the fallof 2003 in Japan is produced according to the high-definition (HD) standards.
Therefore the information transmission speed significantly increased than in the conventional
standards, necessitating adoption of optical fiber for TV camera cables. Moreover, the cable
was required to have high resistance against flexure and twist, unprecedentedly high for opticalfiber cables. In response to such a requirement, the authors have developed, after various
investigations, a TV camera cable with high durability. With respect to optical termination box,
which is an indispensable component for optical fiber connection, they have also developed a
new termination box provided with high usability and small footprint.

ABSTRACT1.

INTRODUCTION

The content of programs for terrestrial digital
broadcasting that started in the fall of 2003 in Japanis produced according to the high-definition (HD)standards. Accordingly, we have developed a cablesystem for HDTV imaging cameras consisting of an
optical fiber composite cable (hereafter called “TVcamera cable”) and its peripheral components. This
paper reports on the development.
The TV camera cable shown in Photo 1, whichconnects a TV camera with its control unit, is used invarious service environments. For instance, the cable
may be hung on trees during the live coverage of a golfmatch, and it may be wound, occasionally in the studio,in the shape of 8 with a very small diameter using hands.
See Photo 2. The cable may be handled by many users,
male or female, ranging from skilled technical staff topart-time student workers. Thus this TV camera cablehas been developed attaching much importance to theresistance against irregular flexure and twisting expected
to be caused in such operational environments.
In addition, because the cable is touched over the entire
surface with bare hands and is often dragged across thefloor, the cable characteristics are severely controlled
including surface smoothness, sliding property, abrasion
resistance and appearance.

2.

Photo 1

Various components of optical fiber
cable system for TV camera.

Photo 2

TV camera with optical fiber cables
at a studio.

TV CAMERA CABLES

The background of the TV camera cable development up
to the present will be briefly described below.
Photos 3 through 5 show the appearance of TV camera* Insulated Wire Production Dept., Power Cables Div.

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2004

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An Optical Fiber Cable System for HDTV Cameras������� �����

Photo 3

Optical fiber cable forhandy camera.

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Photo 4�����

Optical fiber cable forstandard camera.

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Photo 5

Optical fiber cable with connectors.

cables.
As shown in Figure 1, this cable has a composite
structure comprising two optical fibers and six metallic
wires. The cable is a standardized article of Associationof Radio Industries and Businesses (ARIB), and plentyof the cable has been launched into the marketplacein recent years aiming at the market of terrestrial digital
broadcasting. Whereas the mainstream was triaxial
cables conventionally, the optical composite cablehas been adopted due to various reasons such as theincrease in information volume and the elimination oftransmission distance limitations.
At this transition stage from triaxial cable to opticalcomposite cable, Furukawa Electric embarked on thedevelopment of new TV camera cables. The cable users
required that the new cable should have usability anddurability equal to or better than those of triaxial cables
conventionally used.
In the development of the TV camera cable, wehave carried out, under the cooperation of connector
manufacturers and our customers, on-site evaluation of
the cable usability and durability at the studio, thereby
introducing cumulative improvements on the cable
design based on feedback from the fresh idea of TV
camera cable operators.
In parallel with this, comparisons were madewith triaxial cables and existing products of othermanufacturers, and cable design was promoted
assuming various service environments in terms ofdurability, flexure and twist. This is thought to be thereason why our products have acquired the highest
reputation in the broadcasting market.
Furthermore, as optical TV camera cables became

Structure of optical fiber cable.

common in the market, those with partially upgraded
performance began to be required for special service
environments whereby, as mentioned earlier, due todiversified users and increased service frequencies,
cables with much improved performance against
irregular flexure and twist became necessary. Forexample, especially in popular song programs andvariety programs, cables are exposed to a very severe
service environment due to the flexure and twist exerted
on them. Against this background, we also reexamined
the structure and material to improve cable durability,
thus succeeding in achieving the required performanceagainst such a severe service environment.

3.

MINIATURIZATION OF OPTICALTERMINATION BOX FOR TV CAMERACABLE

In connecting optical fiber cables including composite
cables, closures and termination boxes are usuallyused. Connection of the TV camera cables constitutes
no exception to this rule, so that a dedicated opticaltermination box comprising an optical termination tray
and connectors for power and signal wires is used.
In the TV camera cable system, TV camera cables areinstalled as infrastructure in the stadium or studio. The
installed cables are normally connected, after their one orboth ends are terminated at the optical termination box,with receptacle connectors (hereafter called “connector”)
provided on a connector panel.
The conventional optical termination box shown in
Photo 6 has a sufficient storage space secured inside,
so that the box is still in wide use today due to its goodusability. However, the difficulty is that it is not easy tosecure a space for an optical termination box in theexisting distribution frame because of the congested
wiring, and that sufficient space has to be allowed for incase of new design for an optical termination box andthe wiring right back of connectors. Accordingly, it wasrequired this time to miniaturize the optical termination
box and to save labor in the associated design work.
In view of the fact that the conventional method ofwork changes from place to place according to suchconditions as the relative position of termination box withFurukawa Review, No. 25

200425

An Optical Fiber Cable System for HDTV Cameras����� ���������� ��������� �����

Photo 8

Photo 6

Tray of FOP Unit, an improvedversion of B Unit.

Conventional termination box.

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Photo 7

Optical termination box (B Unit).

respect to connectors together with the piping layout, wehave decided to develop a termination-box-integrated
panel unit incorporating connector and termination box.
After several years of study in specifications to meet thecustomers’ requirement of “an optical termination box
to be accommodated in the existing panel”, we havedeveloped B Unit shown in Photo 7, realizing a significant
reduction in footprint in comparison with the conventionaltype.
The conventional optical termination box has been
designed according to the following specifications:• Cable is fed in from one direction.
• Optical termination tray is of Furukawa standard size.
• All components including SC connectors arearranged emphasizing usability.
Meanwhile, the B Unit has been designed according tothe following specifications, realizing small footprint:• Cable is fed in from two directions.
• Optical termination tray is of minimized size.
• Parts including cable fixtures and SC connectors arearranged taking advantage of the space on the tray.
In particular, the tray design whereby the center of
its one side is used to feed in and out optical fiber
contributes a great deal to multiway layout of cable feed
as well as to downsizing.
Moreover, the B Unit has the following features:• Direction of cable feeding is not restricted by piping

Photo 9Optical termination box (FOP Unit).

layout.
• The feed-out portion of the cable belongs to theTV camera cable with sufficient strength, so thatmaintainability has been improved.
At present, it is urgently required to develop a newtermination box aiming at further usability and versatility.
We have therefore developed a termination-boxintegrated panel unit named “FOP Unit” based on moregeneral standards such as EIA, JIS, etc.
Whereas the B Unit has such features as:• Minimized size,• Two-way cable feed ports,• Vertical connector mounting panel, and• Skilled workmanship is required,the features of the FOP Unit shown in Photos 8 and 9are:• Size is slightly larger and can be accommodated in
the EIA (3U) and JIS (3J) racks,• Cable feed ports eight in number are circumferentiallyarranged,• Connector mounting panel is slanted by 45°, and• Improved usability.
Specifically, the panel face is slanted by 45° to reduce
the storage space for floor cable or mobile cable andto lighten the load due to the cable’s own weight at its
transition point to connectors.
Because there is no need to choose the direction

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An Optical Fiber Cable System for HDTV Camerasof cable introduction and to care about the wiring
dimensions of the cable, the FOP Unit enables easy
installation of the cable simply by securing the required
volume of the box (width, depth and height dimensionsof the main body), thereby contributing to labor saving ofconnector panel design.
In terms of panel mounting structure onto the standard
19-inch rack, mounting racks according to JIS andEIA have been added to the product lineup, permitting
mounting of up to six connectors at maximum on theheight of JIS 3J or EIA 3U. Thus space saving andtermination work standardization are included as one ofthe features.

4.

FUTURE TASKS

We intend to make efforts to reduce environmental
impacts regarding TV camera cables and to further
improve the total quality including technical expertisein termination assembly. With respect to the opticaltermination box, we plan to optimize the structure, taking
advantage of the characteristics of newly developed
fibers and our know-how in the termination-box-integrated
panel unit, to achieve usability upgrading and footprint
reduction, thus promoting labor saving in design andinstallation work.

5.

CONCLUSION

We owe much of our present success in the development
and production of this TV camera cable and its peripheral
components to many broadcasting corporations, camera
manufacturers, connector manufacturers and cooperatingcompanies. We would like to take this opportunity toexpress our gratitude to them all. It is our hope thatreaders will pass on to us your frank opinions andsuggestions for our future developmental efforts in themarkets both domestic and overseas.

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