US 3413745 A
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Description (OCR text may contain errors)
Dec, 3, 196s R. w. CASE 3,413,745
BLANKOUT S IGN Filed April 5, 1967 FIG. 3
\ j BY;
ATTORNEY 3,413,745 BLANKOUT SIGN Ray W. Cabe, Manhattan Beach, Calif., assignor to Tamar Electronics Industries, Inc., Los Angeles, Calif., a corporation of Delaware Filed Apr. 5, 1967, Ser. No. 628,607 6 Claims. (Cl. 40--132) ABSTRACT 0F THE DISCLOSURE An illuminated sign is in the form of a sandwich structure, a message to be displayed being delineated in clear areas on 'a rear illuminated opaque panel, a central panel of honeycomb structure being sandwiched between the opaque panel and a front panel of translucent material.
In the control of vehicular and pedestrian trafllc it is necessary at certain locations to temporarily display certain predetermined messages to warn that ice or flooded conditions prevail on a thoroughfare, or that a drawbridge is in operation, or to restrict the speed of vehicles during certain hours or conditions, for example, where it is practical to locate a permanent sign which can be illuminated to display the message for the duration of the emergency or condition. At all other times, of course, the message should be blanked out, i.e invisible.
Prior known signs for displaying messages of the foregoing character generally employ a message plate on which the message is spelled out in letters defined by opaque areas on Va clear plate, or in letters defined by clear areas on an opaque plate; the message plate being illuminated by a switch controlled light source located behind the message plate when it is desired to display the message. When it is not desired to display the message, the light source is deenergized.
It has been found, however, that when the light source is off the message becomes visible in the beam of oncoming automobile headlights at night, and during daylight hours by the reflection of the sun off automobile windshields and by direct sunlight Ias well. Thus, it has been necessary to mount louvered screens or baflles over the message plate in an attempt to reduce spurious display of the message plate due to the accidental incidence of light thereon.
However, louvered or baffles have not been satisfactory since any light directed through the louvers or baffles normally upon the surface of the message plate will still render the message visible. Moreover, the louvered screen or baflles tend to obscure the message plate when viewed from the side, i.e., at ya substantially acute angle, when the message is being intentionally illuminated to warn of an emergency or condition.
It is therefore a primary object of my invention t0 provide an electrically illuminated message sign of the character described above which cannot be spuriously displayed by accidental incident light.
It is another object of my invention to provide a message sign of the character described above which is entirely free from obstruction of any kind.
The sign of my invention comprises a conventional message plate, a source of light behind the message plate, a translucent or light diffusing plate positioned in front of the message plate, and light directing means interposed between the message plate and the light-diffusing plate, which light directing means internally reflects and disperses accidental incoming light to effectively prevent spurious display of the message when the light source is deenergized, and which light directing means also dif rects the light from the light source, when energized, through the message defining areas and onto the reverse nited States Patent O ICC side of the light diffusing plate to clearly display the message.
My invention will be more clearly understood by reference to the detailed description and drawings wherein:
FIG. l is a side elevational view in crosssection showing a preferred embodiment of my invention,
FIG. 2 is an exploded view in perspective showing the essential elements of the preferred embodiment, and
FIG. 3 is a fragmentary side elevational View in crosssection of the assembled elements of the sign.
In FIG. l, sign assembly 5 is mounted over the open side of a weatherproof housing 6 which can be mounted on any suitable support (not shown), such as a standard or wall for example. In the housing 6 rearwardly of the sign assembly 5, a generally parabolic reflector 7 is provided which is supported within housing 6 by wall clips 9, and contains a light source such as incandescent lamp 10. Conductor leads 11 extend from the lamp socket 13 through a switch (not shown) toa source of electricity (not shown) provided in the well known manner.
The sign assembly, in accordance with my invention, is in the form of a sandwich structure 13 which sandwich includes a message plate 14 preferably made of durable clear plastic, such as acrylic resin for example, masked with an opaque maskant 15, i.e., coating or paint, having clear areas 16 cut from the mask in the form of letters (not shown) which spell out a message such as ICE or STOP, or numerals as shown in FIG. 2, designating a speed limit such as 25 for example,
Alternatively, the message plate may be an ordinary stencil, i.e., a sheet or panel of opaque material having alphabetical or numeral shaped perforations spelling out a predetermined message.
The message plate 14 is formed with a shallow flat recess 18 surrounded by flanges 17 and 19, the outermost flange 19 being parallel with the recess 18 on which surface the message is defined.
The light directing means, preferably formed of a panel 20 of honeycomb structure fabricated of aluminum foil or other highly reflective material, is dimensioned to t within the shallow recess 18 `formed in the message plate 14, the inner surface of the honeycomb panel 20 abutting the obverse side of the message plate 14, and the outer surface of the honeycomb panel 20 extending parallel with flange 19 of the message plate 14. The axes of the elongated cells 21 of the honeycomb panel must, of course, be positioned normal to the surface of the message plate 14, and define a plurality of light passages as best shown in FIG. 3. I have found that a honeycomb panel from 1/2 to Ss" in thickness provides an effective light directing element.
A front plate 23 of translucent glass or plastic, or glass or plastic material having at least one translucent surface, which may be frosted, for example, is mounted over the forward surface of the honeycomb panel 20 to complete the sandwich -assembly 13, the assembly being mounted and retained within the internal groove 24 of a shock-resistant flexible molded frame 25 fabricated of neoprene or vinyl, for example, as best shown in FIG. 3. The frame 25 has an external peripheral groove 26 fitting over an inwardly extending flange 27 formed around the open side of housing 6, to firmly fasten the frame 25 and sign assembly therein.
In FIG. l, the sign is shown with the lamp 10 energized to display the message. The reflector 7 focuses the light rays emanating from lamp 10 through the clear areas 16 of message plate 14 -along the axes of the honeycomb panel cells 21 onto the reverse side of translucent plate 23 where a substantial portion of the light is diffused and scattered by reflection to produce in effect a bright glow or halation delineating the letter or numeral spelling out front pl-ate substantially as shown.
It will readily be seen that when the lamp 10 is off, i.e., deenergized, most of any light incident to the obverse side of front plate 23 will be dilfused and scattered by the well known principle of light interference at an interface, any remaining light transmitted through front plate 23 and passages 21 being internally reflected -and dissipated through attenuation so that no returning light rays remain to backlight the message plate to produce a spurious display of the message.
With the sign assembly of my present invention, it is not possible for light from the most intense source to backlight the message. It will further be appreciated that the diffused glow produced by the front plate will appear on the obverse surface of the front plate and thus be visible from any acute angle thereto.
While I have described and illustrated a preferred form of my invention using aluminum honeycomb material, many -alternate cellular structures of the same general character, e.g., egg-crate structures, tubular assemblies, etc., will occur to those skilled in the art, all equivalent structures being deemed to fall within the spirit of my invention.
I claim: 1. A blankout sign comprising a message display element defined by an opaque panel having light transmitting areas providing a message,
light diffusing means in the form of a translucent panel disposed adjacent to and parallel with the front surface of said message display element to cover said light transmitting areas thereof,
light directing means interposed between said message display element and said light diffusing means, said means comprising a plurality of discrete parallel elongated passages, the axes of said p-assages being disposed normal to the adjacent surfaces of said message display element and said light diffusing means, and
a light source and reiiector therefor adjacent to said message display element and aligned to direct light through said light transmitting -areas and said passages parallel to the axes of said elongated passages onto said light diffusing means when said source is energized to display said message, said light diffusing means and said light directing passages reflecting and diffusing accidental random light incident to said light diffusing means to prevent said accidental light from spurious display of said message when said light source is deenergized.
2. The blankout sign of claim 1 wherein said light directing means is a panel of honeycomb structure fabricated of highly reflective material.
3. The blankout sign of claim 1 wherein said light Ydirecting Ymeans is a. panel of honeycomb structure fabricated of aluminum foil.
4. The blankout sign of claim 1 wherein said message display lmeans is a panel of transparent material masked with opaque material and having clear areas in the shape of alphabetical or numerical characters spelling out a predetermined message cut out of said opaque material.
5. The blankout sign of claim 1 wherein'said message display means is a stencil formed of opaque material, the perforations being alphabetically or numerically shaped to spell out -a predetermined message.
6. A blankout sign comprising a Vmessage display panel formed-of a transparent material,
an opaque mask mounted over said display panel, said mask being perforated with areas in the shape ot' alphabetical or numerical characters exposing said transparent material to Spell out a predetermined message,
said display panel being formed with a peripheral double ange extending therearound to define a shal low at central depression,
a light diffusing panel having a translucent surface, said panel being disposed parallel with said display panel and abutting the outermost flange thereof,
a light directing panel of highly reflective honeycomb structure dimensioned to fit into said depression, the passages formed by the cells of said honeycomb panel being oriented with their aXes normal to the translucent surface of said light diffusing panel and said message display panel, and in abutting relationship therewith,
substantially flexible frame means surrounding said message display panel, light diffusing panel and light directing panel and retaining said panels together in the form of a sandwich,
a housing having an opening to receive and retain said flexible frame,
a light source and reflector mounted in said housing rearwardly of said panel sandwich, said reilector formed to direct the light rays emanating from said light through said message panel parallel to the axes of said honeycomb structure, and
means for energizing and deenergizing said light source.
References Cited UNITED STATES PATENTS 2,616,957 ll/l952 Thiem. 3,358,394 12/1967 Braude 40-132 X EUGENE R. CAPOZIO, Primary Examiner.
W. J. CONTRERAS, Assistant Examiner.