Method of and Appliances for Producing Luminous Letters and Designs for Advertisements and other Purposes.
Year: 1898

page_text: Method of and Appliances for Producing Luminous Letters and
Designs for Advertisements and other Purposes.
We, PAUL JEAN and ALBERT BOUCIION, both of 97, Rue St. Lazare, Paris,
France, do hereby declare the nature of this invention to be as follows:-
Our invention relates to an improved method of and appliances for obtaining
intense and ornamental light effect for luminous letters and designs.
For this purpose, instead of the arrangement heretofore employed in which a
source of light is placed behind a plate or screen on which the letters or designs
are cut out so that light produced behind the plate passes through the letters &c.
as was heretofore done, we so arrange the sources of light in connection with a
plate having the letters or design cut therein that the light is first projected on
to a bright and if desired, ornamented surface from which it is then reflected
through the open letters. By this means a much more uniform and effective
distribution of the light is obtained than with the construction heretofore
employed.
According to our invention we employ firstly a solid outer plate with bright
surface preferably of metal, and which may either be plain, or corrugated or
ornamented, and secondly, at a limited distance in front of such plate we fix a
second opaque plate or screen, with dark outer surface and bright inner surface,
in which the letters or designs are cut out; thirdly we provide in the space between
the two plates (which is enclosed on all sides) one or more sources of light placed
intermediately between the openings of the letters &c. and the light from which
consequently does not pass directly through the openings formed by the letters
&c., but is projected first on to the bright surface of the back plate on which it
is diffused in a very uniform manner, and from which it is then reflected through
the openings of the letters &c. A portion of the light being also thrown on to
the inner bright surface of the front plate or screen is reflected thence on to the
bright surface of the back plate, from which it is again reflected through the
open letters &c.
In order to prevent the sources of light from being directly seen through the
open letters, the edges of these are preferably provided with inward projecting
rims.
Instead of arrange the sources of light in the space between the front and back
plates, we in some cases form openings or recesses in the latter in which the
Fources of light are placed preferably provided with reflectors so that the light is
projected first on to the inner surface of the front plate, then on to the back plate,
and thence through the open letters &c.

page_text: According to another modification, we construct the apparatus double, that is
to say, with two opposite outer plates in both of which the open letters &c. are
cut, and a middle plate having two bright reflecting surfaces, one of which serves
for the one outer plate and the second one for the other. The sources of light
may in this case be either provided on each side of the middle reflecting plate or
preferably they are placed in openings in the reflecting plate so as to serve for
both sides thereof.
100l d
of Datah 1900
ABEL & IMRAY,
Agents for the Applicants.
Method of and Appliances for Producing Luminous Letters and
Designs for Advertisements and other Purposes.
We, PAUL JEAN and ALBERT BOUCHON, both of 97, Rue St. Lazare, Paris,
France, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
Our invention consists in a method of illuminating which has for its object to
produce for the purpose of luminous advertisement, decoration and the like, with
the aid of apparatus of moderate dimensions, intense luminous effects similar to
those which would be produced by letters which are cut out separately from a
bright metallic sheet or plate and that are intensely illuminated by means of an
electric projector lamp in such a manner as to shew up the said letters very
sharply and with metallic reflection in the darkness of the night. This method
of illuminating affords the maximum visibility, but is inapplicable because it
requires special conditions which shall allow of placing the projector at a sufficient
distance for illuminating uniformly the whole of the design.
Our method consists substantially.
1. In substituting for cut-out letters, a continuous plate or backing having a
smooth bright surface, or which may be undulating, crimped or ornamented in
any suitable manner, but in all cases being illuminated in an intense and uniform
man r by one of the means hereinafter described.
2. In placing at a small distance in front of said backing relatively to the
cbserver, an opaque wall of a dark colour and which is not illuminated on its
front side, and in which are cut openings in the form of the letters designs or
devices of any kind which are to be shewn up by the illumination.
This perforated wall thus shews externally only those parts of the bright
backing which can be seen through the cut-out devices that are shewn up power-
fully on the front dark surface of the said wall, so that the design formed by the
cut-out portions is shewn very sharply in light.
The illumination of the bright backing is effected by one of the apparatus
shewn in cross section in the diagrammatic Figures 1, 2 and 3 of the accom-
panying drawings, that is to say, by arranging behind the cut-out wall 1, one or
more sources of light 2 of suitable nature and intensity. These sources of light
are, as a general rule, placed behind the full or solid portions of the wall I in such
a manner as to be hidden from the observer and so as not to hinder in any way
the view of the bright backing 3, shewing through the cut-out letters. "Small

page_text: inclined screens 5, 5 may for this purpose be arranged inside the apparatus along
the edges of the cut-out letters for the purpose of preventing the sources of light
from being seen from a point of view obliquely to the apparatus. The rays
emitted from the sources of light 2 are projected on to the backing 3 either
directly or by reflection or partly directly and partly by reflection from the inner
surface 4 of the wall 1, which said surface is for this purpose made reflecting or
is painted white or of any other light colour which absorbs the least possible amount
of light and which is as much as possible of a diffusing nature. The sources of
light 2 whilst being arranged behind the full parts of the perforated front wall 1,
may be placed;-
(a). Either in front of the bright backing 3 (Fig. 1), in which case the latter
being illuminated both by the direct rays and by the rays reflected from the inner
surface 4 of the wall 1, (along the paths shewn in dash-dotted lines) reflects the
image of the said surface which is uniformly lighted, whilst preserving its metallic
lustre.
(b). Or the sources of light may be arranged in the same plane as, (Fig. 2) or
slightly to the rear (Fig. 3) of the bright backing 3 in which case the said backing
is illumined exclusively by the rays reflected from the surface 4 of the wall 1,
but it will still shine with uniform brightness by reason of the fact that it reflects,
as in the preceding case, the image of the surface 4 without however, ever being
able to give a direct image of the source of light.
We have shewn by way of example several applications of the devices as
specified by the preceding general description. The luminous board or tablet
having only one face, which is shewn in elevation, horizontal section and cross
section in Figs. 4, 5 and 6, is provided with the arrangement referred to under (a).
It consists of a metallic case, the front wall 1 of which fulfils the function of the
perforated opaque wall above mentioned. The bright backing is constituted by
the rear wall 3 and is lighted by a series of electric lamps 2 which may be in any
number but which are always situated in front of said backing and behind the full
portions of the wall 1.
The apparatus shewn in similar views at Figs. 7, 8 and 9 is similar to the
preceding arrangement, but it has two faces and is lighted by means of the
arrangement referred to under (6). This apparatus comprises two perforated
opaque walls 1 and 1' constructed according to the conditions above mentioned
and placed on either side of an undulating or crimped hacking 3 whose two
surfaces are bright and are lighted up by sources of light 2, 2 (for example
Welsbach burners) arranged in the same plane as the backing 3 and from which
the rays of light are reflected upon the said backing from the reflecting inner
surfaces of the cut-out opaque walls 1 and 1', the sources of light 2, 2 being in
this case hidden from external observation by the full portions of the wall 1 as
well as by those of the wall 11.
For the purpose of illuminating luminous pictures or tablets of small length,
we may employ the arrangement shewn in Fig. 10, that is to say, we may
illuminate the apparatus solely by means of sources of light 2, 2 placed at its ends
either in the same plane as the bright backing 3 (which position is shewn in full
lines), or on each side of the said plane (which position is shewn in dotted lines).
In this case also we may employ a bright backing 3 of greater or less curvature
(as shewn in dash dotted lines) in such a manner that the parts of said backing
which are furthest away from the sources of light shall be situated nearest to the
apertures with a view of rendering the luminous effect thereof more uniform.
The letters &c. may be either simply cut out (as shewn at Figs. 4, 5 and 6): or
they may be bordered with a bevel edge as shewn at the letter L of Figs. 7, 8
and 9 or with a continuous projection formed by a double inclined plane, as
shewn at the letter U which are designed to shew up the outlines of letters; or
they may be provided with narrow slits, as shewn at the letter X, with the object
of simulating a relief of the letter; or they may be ornamented in any suitable
manner.

page_text: In cases where the sign or luminous inscription comprises two or more lines of
writing placed one above the other we employ by preference, the arrangement
shewn in Fig. 11 which allows of the illumination of such lines of letters by means
of one single row of sources of light. As shewn in this fig., the letters which
compose the lines which are superposed, one above the other, (two are shewn in
the example) are cut out in the opaque front wall 1 of the apparatus. At the rear
of the lower line, there is arranged the bright, smooth, undulating or crimped
backing 3 which is divided into several segments between which are placed behind
the full, parts of the wall 1, the Welsbach burners 2, 2; this arrangement
fulfilling with respect to the lower line of letters the same function as that which
was described with reference to Figs. 7, 8 and 9. For the purpose of producing
the illumination of the upper line, the apparatus is further provided with a
backing 4, 4, having an inner bright surface or of a light colour, and or of a
smooth, undulating or crimped nature formed of two or more flat parts suitably
inclined or it may be curved in cross section so as to cause a part of the luminous
rays to be reflected (following for example the paths shewn in dash dotted line)
so as to pass out of the apparatus through the cut-out letters of the upper line
and thus to represent in light the shape of the letters of that line. This arrange-
ment, of which the constructional details can obviously vary according to each
particular application, has as compared with the preceding arrangements, in the
particular cases for which it is intended, the advantage of enabling two or more
lines of a luminous sign to be illuminated by a number of sources of light which
number is not greater than that which is necessary for the illumination of a single
line. In this respect therefore it affects a considerable economy in the con-
sumption of light.
Our apparatus may also be arranged to allow the device cut out in the opaque
wall to be seen very clearly by daylight. For this purpose we give to the back-
ing 3 a colour which forms a sufficient contrast with that of the outer or visible
face of the front opaque wall 1.
The bright backing 3 may be either smooth or preferably undulating or crimped
in such manner as to produce brilliant reflexes or decorative flashes of light.
The sources of light, 2, 2, may be in any suitable number and may be arranged
at the lower part, half way, or at the upper part of the luminous sign, as shewn
in Fig. 7. Our system has the advantage of requiring for the erection of the
illuminating apparatus only a, slight depth of the case which can in practice be
reduced to a few centimetres. The cut out devices in the opaque walls may, if
desired, be covered with a thin plate of glass or other transparent substance
intended to prevent the wind, rain, or dust from entering the interior of the
casing.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, we declare that what we
claim is:-
1. A method for illuminating by reflected light, letters, designs, sign boards
and other luminous devices, which consists in arranging in front of a continuous
backing having a bright smooth or undulating or crimped surface or ornamented
in any suitable manner, and illumined in an intense and uniform manner, an
opaque wall of dark colour which is not illuminated on its front surface and which
has an internal surface of reflecting or diffusing nature, in which wall the letters
or other designs to be shewn up in light are cut out, the said bright backing being
illuminated by means of sources of light which are always hidden behind the full
parts of the opaque wall in which the letters are cut out, and which sources of
light are placed either in front of, or in the same plane as, or slightly behind, the
bright backing, substantially as described.
2. An apparatus having a single face or a double face, serving for the appli-
cation of the method specified in the first claim and characterised by the
combination of a backing made bright on one face or on both faces, with one or

page_text: two perforated opaque walls having an internal reflecting or diffusing face, and
with a certain number of sources of light arranged substantially as described.
3. Apparatus for producing luminous letters, designs, or other luminous devices,
constructed and operating as herein described with reference to the accompanying
drawings.
Th
301
1