EP0390479A2 - Light emitting diode clusters for display signs - Google Patents

Light emitting diode clusters for display signs Download PDF

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Publication number
EP0390479A2
EP0390479A2 EP90303218A EP90303218A EP0390479A2 EP 0390479 A2 EP0390479 A2 EP 0390479A2 EP 90303218 A EP90303218 A EP 90303218A EP 90303218 A EP90303218 A EP 90303218A EP 0390479 A2 EP0390479 A2 EP 0390479A2
Authority
EP
European Patent Office
Prior art keywords
light emitting
socket
cluster
unit
emitting diode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP90303218A
Other languages
German (de)
French (fr)
Other versions
EP0390479A3 (en
Inventor
Vincent J. Mcewan
Milan J. Patel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ledstar Inc
Original Assignee
Ledstar Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ledstar Inc filed Critical Ledstar Inc
Publication of EP0390479A2 publication Critical patent/EP0390479A2/en
Publication of EP0390479A3 publication Critical patent/EP0390479A3/en
Withdrawn legal-status Critical Current

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Classifications

    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09FDISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F27/00Combined visual and audible advertising or displaying, e.g. for public address
    • G09F27/008Sun shades, shades, hoods or louvres on electronic displays to minimise the effect of direct sun light on the display
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21KNON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
    • F21K9/00Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
    • F21K9/20Light sources comprising attachment means
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09FDISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F13/00Illuminated signs; Luminous advertising
    • G09F13/04Signs, boards or panels, illuminated from behind the insignia
    • G09F13/0418Constructional details
    • G09F13/0472Traffic signs
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09FDISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F13/00Illuminated signs; Luminous advertising
    • G09F13/20Illuminated signs; Luminous advertising with luminescent surfaces or parts
    • G09F13/22Illuminated signs; Luminous advertising with luminescent surfaces or parts electroluminescent
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09FDISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • G09F9/33Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements being semiconductor devices, e.g. diodes
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21VFUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V31/00Gas-tight or water-tight arrangements
    • F21V31/04Provision of filling media
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21WINDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO USES OR APPLICATIONS OF LIGHTING DEVICES OR SYSTEMS
    • F21W2111/00Use or application of lighting devices or systems for signalling, marking or indicating, not provided for in codes F21W2102/00 – F21W2107/00
    • F21W2111/02Use or application of lighting devices or systems for signalling, marking or indicating, not provided for in codes F21W2102/00 – F21W2107/00 for roads, paths or the like
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21YINDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2105/00Planar light sources
    • F21Y2105/10Planar light sources comprising a two-dimensional array of point-like light-generating elements
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21YINDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2105/00Planar light sources
    • F21Y2105/10Planar light sources comprising a two-dimensional array of point-like light-generating elements
    • F21Y2105/12Planar light sources comprising a two-dimensional array of point-like light-generating elements characterised by the geometrical disposition of the light-generating elements, e.g. arranging light-generating elements in differing patterns or densities
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21YINDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00Light-generating elements of semiconductor light sources
    • F21Y2115/10Light-emitting diodes [LED]
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09FDISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F13/00Illuminated signs; Luminous advertising
    • G09F13/20Illuminated signs; Luminous advertising with luminescent surfaces or parts
    • G09F13/22Illuminated signs; Luminous advertising with luminescent surfaces or parts electroluminescent
    • G09F2013/222Illuminated signs; Luminous advertising with luminescent surfaces or parts electroluminescent with LEDs

Definitions

  • the invention relates to a light emitting diode cluster unit comprising an array of light emitting diodes and suitable for use in display signs such as those used on highways to display information to motorists.
  • Such display signs have traditionally used fluorescent or incandescent lamps which are expensive in electricity and may need frequent maintenance and repair.
  • Each lamp usually forms an appreciable part of any letter in a display of information, and so, if any one lamp becomes non-functional it has an appreciable effect on decipherability and as more lamps become non-functional it may be considerably more difficult to decipher the letter.
  • U.S. Patent No. 4 727 289 discloses a lamp comprising a plurality of light-emitting diodes (LEDs) on a printed circuit board and arranged inside a glass bulb. Current is supplied to the LED through a series resistor having an annular shape and fitted around the stem of the lamp. Lamps according to that patent may be used for displays while providing advantages such as:
  • a light emitting diode cluster unit for outdoor use comprising: a connector socket for direct connection into an electric outlet, the connection socket being provided with first electric contacts within the socket and electric connection means through a rear wall and adapted for connection into said outlet; a housing for a cluster of light emitting diodes slidably nested within said connector socket and being an open fronted socket having electrical connection means extending through a rear wall to second electric contacts adapted to connect said first electric contracts of said connection socket, the light emitting diodes being positioned on a circuit board and embedded in potting compound within the housing socket light emitting domes of the light emitting diodes projecting from a front surface of the potting compound, a connector socket for said housing for connection into an electrically operated display.
  • a generally tubular visor is provided extending forwardly of the light emitting diode cluster.
  • the invention also provides a display sign incorporating a light emitting diode unit according to the invention.
  • An LED unit 10 for outdoor use comprises a three-part structure of an LED cluster member 14 resting in a connector socket member 16, which itself fits, on the one hand, into one end of a tubular visor member 12 and, on the other hand, is provided with means for direct connection into a display sign.
  • a cluster of LEDs 20 is set on a circuit board 22.
  • the LEDs 20 are suitably mixed red and yellow LEDs, the red and yellow LEDs having their own connections to supply circuit for electricity.
  • One suitable pattern of red and yellow LEDs 20 is shown in Figure 3. Suitable series resistors may be provided to guard against overloading the LEDs.
  • the circuit board 22 with its cluster of LEDs 20 is connected with wiring 24 for both red and yellow LEDs to socket connections of a generally cylindrical housing 26 for the LED cluster.
  • the housing 26 is open to one side and is provided with a projection 27 housing socket electrical sockets 29 for pins 30 of the connector member 16.
  • Suitably four such sockets 29 may be provided as seen in Figure 6.
  • the circuit board 22 fits into the housing 26 and is set therein in potting compound 28 so that the cluster of LEDs project towards the front of the housing.
  • potting compound 28 may both firmly set the LEDs in position and seal them into the housing so that the arrangement may be water-right.
  • the top domes of the LEDs 20 project from the potting compound 28 to provide light at the front opening of the housing 26.
  • the housing 26 may suitably be of circular section to receive a circular cluster of LEDs but other shapes are possible.
  • An arrangement or circular clusters (Figure 3) is especially useful for highway text displays where light bleed between pixels is of concern.
  • the housing 26 rests slidably in connector member 16 with pins 30 of the connector member in electrical contact in socket connections 29 of housing 26. As shown, there are four pins 30, each mating with a socket 29. Two of these pins are provided to connect wiring the red LEDs and two of them are provided to connect wiring to the yellow LEDs. However, it will be appreciated that an infinite variety of colour patterns are possible and it is not necessary to provide two different colours of LEDs in a unit 10; either less or more colours are possible.
  • the connecting socket member 16 comprises a socket of similar cross-section to that of the cluster member 14, and pins 30 for mating with sockets 29.
  • the connecting socket member 16 may be useful to provide directionality to the housing 26 and to protect the circuit board in housing 26 from any torque during connection of the unit into the main display board.
  • driver circuitry may be mounted directly behind the connector socket, thus saving space and the cost of separate driver circuits.
  • the arrangement may provide protection of driver circuits from ultraviolet rays.
  • each housing 26 may be provided with at least one peripheral groove for a sealing ring 32. As shown, two sealing rings 32 are provided. These rings 32 may seal with the interior of connecting socket member 16.
  • sockets 29 are provided in a projection 27 from the back of housing 26 which projection fits into a corresponding recess 34 of connector member 16, which recess houses pins 30. While the projection 27 and recess 34 are shown as having circular cross-sections, there is no reason why they should not be of other shapes, e.g., triangular or hexagonal, to aid proper location of pins 30 in sockets 29. Alternatively, a locating rib and groove may be provided on respective ones of the projection 36 and recess 34.
  • Plug member 38 is provided on the back of connecting socket 16 for direct connection into a display sign having suitable electric power supply to power the LEDs, and within the socket 16 connector means are provided for the sockets 29 of the cluster member 14.
  • the arrangement as so far described may be advantageous in that it is inexpensively and easily assembled without the need for encapsulating the LED clusters in a frangible glass bulb.
  • the resultant combination of LED cluster member 14 and connector socket member 16 is robust and the cushioning of the LEDs in water-proof potting compound may provide protection for the LEDs resulting in long life and little or no maintenance.
  • the arrangement may be subject to reduced tendency to be obscured by glare of reflected light, such as sunlight, therefrom.
  • pulse width modulation can be used to infinitely vary the light output level of the cluster to match the ambient light levels.
  • visor 12 may provide several additional advantages, in that visor 12 covers connector member 16 and may contribute to protecting it from dust, dirt and exhaust fumes.
  • the intended function of visor 12 is to shield the LED cluster from sunlight and from laterally incident light.
  • the visor acts to focus the light output towards the viewer. For example, in the highway application it is important the motorists in peripheral traffic lanes do not read messages which do not apply to them.
  • the visor also prevents light bleed between pixels which ensures proper definition of each character.
  • Each visor 12 comprises a tube, one end portion of which fits slidably over connecting member 16 and is aligned axially with it. Stops 40 may be provided on member 16 for visor 12 to determine its final position or member 16.
  • the visor 12 is considerably longer in its axial dimension than cluster member 14 and connector member 16 and is suitably made from dark coloured plastic with a matte surface.
  • the visor 12 may be shaped at its front end to form an upper hood portion 42 and a lower cut away portion 44.
  • the upper hood portion 42 may act as additional protection from overhead light and lower cut away portion 44 may aid vision of the display via tubular visor 12.
  • the visor 12 may suitably be between 2 inches to 12 inches in length for example it may be more than 4 inches at its cut away portion 44 and more than 8 inches at its hood portion 42.
  • the combination of the LED cluster member 14 nested within the connector member 16 may have a length of around 1 inch.
  • the visor member may suitably be around ten times as long as the LED cluster in its connecting member.
  • a rib and groove or other locating means may be provided to locate the hood in an upper position. Because the visor is a simple tube easily slidable onto the connector member, it is easily replaceable when required. It may be made to be robust to withstand breakage and deterioration due to environmental conditions.
  • a housing for a cluster of light emitting diodes slidably nested within said connector socket and being an open-fronted socket having electrical connection means extending light emitting diodes through a near wall to second electric contacts adapted to connect with said first electric contacts of said connector socket, positioned on a circuit board and being housing embedded in potting compound within the socket light emitting domes of the light emitting diodes projecting from a front surface of the potting compound, a connector socket for said housing for connection into an electrically operated display; and in the event, over a long term, if deterioration does occur, the visor is inexpensive.
  • FIG. 5 is a sketch giving a general indication of the use of units 10 in display sign.
  • each unit 10 forms an integer of each letter or other symbol of the sign.
  • letter or symbol definition may be improved over the case where a single incandescent unit is used for a similar integer.

Abstract

A light emitting diode cluster unit (10) suitable for use in outdoor display signs. A cluster (14) of LEDs on a circuit board (22) is housed in a first socket (26) open to its front and nested in an outer connector socket (16). Electrical connections (29, 30) are made from the rear of the first socket (26) via the connector socket (16) to a source of electricity. The connector socket (16) provides weather proofing and protects the circuit board (22) from torque. Moreover, the driver circuits of a display board into which the unit is connected may be shielded from ultraviolet rays. A tubular visor (12) may be provided to the front.

Description

    BACKGROUND OF THE INVENTION Field of the Invention
  • The invention relates to a light emitting diode cluster unit comprising an array of light emitting diodes and suitable for use in display signs such as those used on highways to display information to motorists.
  • Background of the Invention
  • Display signs used for advertising or for displaying direction or other information to motorists have an important feature in common. They should be eye-catching and their information should be easy to absorb. This is especially true of signs to be located on the highway where the motorist may be moving fast and may need to absorb the information quickly.
  • Such display signs have traditionally used fluorescent or incandescent lamps which are expensive in electricity and may need frequent maintenance and repair. Each lamp usually forms an appreciable part of any letter in a display of information, and so, if any one lamp becomes non-functional it has an appreciable effect on decipherability and as more lamps become non-functional it may be considerably more difficult to decipher the letter.
  • U.S. Patent No. 4 727 289, issued 23rd February, 1988 to Akio and assigned to Stanley Electric Co. Ltd., discloses a lamp comprising a plurality of light-emitting diodes (LEDs) on a printed circuit board and arranged inside a glass bulb. Current is supplied to the LED through a series resistor having an annular shape and fitted around the stem of the lamp. Lamps according to that patent may be used for displays while providing advantages such as:
    • 1. the provision of a very large number of discrete light sources (LEDs). If only a few of the LEDs fail, there will be little visual deterioration to the display,
    • 2. by suitable selection of the LEDs, the colour of the display or parts of the display is easily adjustable without the use of tinted glass or other filters, and
    • 3. a considerable saving in energy cost.
  • However, it might be desirable to reduce the expense of manufacture of such LED arrays within conventional glass bulbs. Moreover, when used for displays, the glass bulb itself may produce some glare and reflection of, example, sunlight, thus tending to confuse the display. Also the reliability of the connector socket may not be high due to the fact that the contacts are not environmentally sealed and are therefore susceptable to corrosion. Corrosion in the socket may make it difficult to replace the bulb especially in harsh environments such as highways.
  • SUMMARY OF THE INVENTION
  • According to the present invention, there is provided a light emitting diode cluster unit for outdoor use comprising: a connector socket for direct connection into an electric outlet, the connection socket being provided with first electric contacts within the socket and electric connection means through a rear wall and adapted for connection into said outlet; a housing for a cluster of light emitting diodes slidably nested within said connector socket and being an open fronted socket having electrical connection means extending through a rear wall to second electric contacts adapted to connect said first electric contracts of said connection socket, the light emitting diodes being positioned on a circuit board and embedded in potting compound within the housing socket light emitting domes of the light emitting diodes projecting from a front surface of the potting compound, a connector socket for said housing for connection into an electrically operated display. Preferably, a generally tubular visor is provided extending forwardly of the light emitting diode cluster. The invention also provides a display sign incorporating a light emitting diode unit according to the invention.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • Embodiments of the invention will now be described by way of example with reference to the drawings in which:
    • Figure 1 is a view mainly in section of a disassembled LED unit according to an embodiment of the invention;
    • Figure 2 is a view similar to that of Figure 1 with the unit assembled;
    • Figure 3 is a sketch showing one pattern of red and yellow LEDs in a unit; and
    • Figure 4 is a sketch of the unit from the rear showing terminals for connection into an outlet; and
    • Figure 5 is a sketch of a display sign according to the invention comprising LED units;
    DESCRIPTION OF THE PREFERRED EMBODIMENT
  • An LED unit 10 for outdoor use comprises a three-part structure of an LED cluster member 14 resting in a connector socket member 16, which itself fits, on the one hand, into one end of a tubular visor member 12 and, on the other hand, is provided with means for direct connection into a display sign.
  • A cluster of LEDs 20 is set on a circuit board 22. For display signs for written information, the LEDs 20 are suitably mixed red and yellow LEDs, the red and yellow LEDs having their own connections to supply circuit for electricity. One suitable pattern of red and yellow LEDs 20 is shown in Figure 3. Suitable series resistors may be provided to guard against overloading the LEDs.
  • The circuit board 22 with its cluster of LEDs 20 is connected with wiring 24 for both red and yellow LEDs to socket connections of a generally cylindrical housing 26 for the LED cluster. The housing 26 is open to one side and is provided with a projection 27 housing socket electrical sockets 29 for pins 30 of the connector member 16. Suitably four such sockets 29 may be provided as seen in Figure 6. The circuit board 22 fits into the housing 26 and is set therein in potting compound 28 so that the cluster of LEDs project towards the front of the housing. Thus, potting compound 28 may both firmly set the LEDs in position and seal them into the housing so that the arrangement may be water-right. The top domes of the LEDs 20 project from the potting compound 28 to provide light at the front opening of the housing 26.
  • The housing 26 may suitably be of circular section to receive a circular cluster of LEDs but other shapes are possible. An arrangement or circular clusters (Figure 3) is especially useful for highway text displays where light bleed between pixels is of concern.
  • The housing 26 rests slidably in connector member 16 with pins 30 of the connector member in electrical contact in socket connections 29 of housing 26. As shown, there are four pins 30, each mating with a socket 29. Two of these pins are provided to connect wiring the red LEDs and two of them are provided to connect wiring to the yellow LEDs. However, it will be appreciated that an infinite variety of colour patterns are possible and it is not necessary to provide two different colours of LEDs in a unit 10; either less or more colours are possible.
  • The connecting socket member 16 comprises a socket of similar cross-section to that of the cluster member 14, and pins 30 for mating with sockets 29.
  • The connecting socket member 16 may be useful to provide directionality to the housing 26 and to protect the circuit board in housing 26 from any torque during connection of the unit into the main display board. By the use of a connecting socket 16, driver circuitry may be mounted directly behind the connector socket, thus saving space and the cost of separate driver circuits. Moreover, the arrangement may provide protection of driver circuits from ultraviolet rays.
  • To aid weather proofing, each housing 26 may be provided with at least one peripheral groove for a sealing ring 32. As shown, two sealing rings 32 are provided. These rings 32 may seal with the interior of connecting socket member 16.
  • Conveniently, sockets 29 are provided in a projection 27 from the back of housing 26 which projection fits into a corresponding recess 34 of connector member 16, which recess houses pins 30. While the projection 27 and recess 34 are shown as having circular cross-sections, there is no reason why they should not be of other shapes, e.g., triangular or hexagonal, to aid proper location of pins 30 in sockets 29. Alternatively, a locating rib and groove may be provided on respective ones of the projection 36 and recess 34.
  • Plug member 38 is provided on the back of connecting socket 16 for direct connection into a display sign having suitable electric power supply to power the LEDs, and within the socket 16 connector means are provided for the sockets 29 of the cluster member 14.
  • The arrangement as so far described may be advantageous in that it is inexpensively and easily assembled without the need for encapsulating the LED clusters in a frangible glass bulb. The resultant combination of LED cluster member 14 and connector socket member 16 is robust and the cushioning of the LEDs in water-proof potting compound may provide protection for the LEDs resulting in long life and little or no maintenance. Moreover, the arrangement may be subject to reduced tendency to be obscured by glare of reflected light, such as sunlight, therefrom. Also pulse width modulation can be used to infinitely vary the light output level of the cluster to match the ambient light levels.
  • The provision of visor 12 may provide several additional advantages, in that visor 12 covers connector member 16 and may contribute to protecting it from dust, dirt and exhaust fumes. However, the intended function of visor 12 is to shield the LED cluster from sunlight and from laterally incident light. Thus the visor acts to focus the light output towards the viewer. For example, in the highway application it is important the motorists in peripheral traffic lanes do not read messages which do not apply to them. The visor also prevents light bleed between pixels which ensures proper definition of each character.
  • Each visor 12 comprises a tube, one end portion of which fits slidably over connecting member 16 and is aligned axially with it. Stops 40 may be provided on member 16 for visor 12 to determine its final position or member 16. The visor 12 is considerably longer in its axial dimension than cluster member 14 and connector member 16 and is suitably made from dark coloured plastic with a matte surface. Moreover, the visor 12 may be shaped at its front end to form an upper hood portion 42 and a lower cut away portion 44.
  • The upper hood portion 42 may act as additional protection from overhead light and lower cut away portion 44 may aid vision of the display via tubular visor 12.
  • The visor 12 may suitably be between 2 inches to 12 inches in length for example it may be more than 4 inches at its cut away portion 44 and more than 8 inches at its hood portion 42. The combination of the LED cluster member 14 nested within the connector member 16 may have a length of around 1 inch. Thus, the visor member may suitably be around ten times as long as the LED cluster in its connecting member. Suitably a rib and groove or other locating means may be provided to locate the hood in an upper position. Because the visor is a simple tube easily slidable onto the connector member, it is easily replaceable when required. It may be made to be robust to withstand breakage and deterioration due to environmental conditions. However, a housing for a cluster of light emitting diodes slidably nested within said connector socket and being an open-fronted socket having electrical connection means extending light emitting diodes through a near wall to second electric contacts adapted to connect with said first electric contacts of said connector socket, positioned on a circuit board and being housing embedded in potting compound within the socket light emitting domes of the light emitting diodes projecting from a front surface of the potting compound, a connector socket for said housing for connection into an electrically operated display; and in the event, over a long term, if deterioration does occur, the visor is inexpensive.
  • Figure 5 is a sketch giving a general indication of the use of units 10 in display sign. Suitably each unit 10 forms an integer of each letter or other symbol of the sign. However, in the event of component failure, it is unlikely that all the LEDs of a unit will fail together. Thus, in the event of component failure, letter or symbol definition may be improved over the case where a single incandescent unit is used for a similar integer.

Claims (8)

1. A light emitting diode cluster unit (10) for outdoor use comprising: a connector socket (16) for direct connection into an electric outlet, the connector socket (16) being provided with first electric contacts (30) within the socket and electric connector means through a near wall and adapted for connection into said outlet; a housing (26) for a cluster (14) of light emitting diodes slidably nested within said connector socket and being open fronted having electrical connection means (29) extending through a rear wall and adapted to connect said first electric contacts (30) of said connector socket (16), the light emitting diodes (20) being positioned on a circuit board (22) and embedded in potting compound (28) within the housing (26) so that the light emitting domes of the light emitting diodes project from a front surface of the potting compound.
2. A unit as claimed in Claim 1 including a generally tubular visor (12) extending forwardly of the light emitting diode cluster (14).
3. A unit as claimed in Claim in which the visor (12) includes an upper hood portion (42) extending further forwardly of a main visor portion.
4. A unit as claimed in Claim 2 in which the visor (12) extends forwardly of the light emitting diode cluster (14) by between 5 cms and 30.5 cms (2 inches and 12 inches).
5. A unit as claimed in Claim 1 in which the light emitting diode cluster (14) includes a plurality of light emitting diodes for emitting one colour of light (R) and a plurality of light emitting diodes for emitting another colour of light (Y).
6. A unit as claimed in Claim 1 in which weather sealing (32) is provided between the connector socket (16) and the housing (26).
7. An electrical display sign having electrical outlets for a plurality of light emitting diode units (10) including light emitting diodes (20) connected into said outlets, each light emitting diode unit (10) comprising: a connector socket (16) for direct connection into an electric outlet, the connector socket being provided with first electric contacts (30) within the socket and electric connector means through a near wall and adapted for connection into said outlet; a housing (26) for a cluster (14) of light emitting diodes slidably nested within said connector socket (16) and being open fronted with electrical connection means (29) extending through a rear wall adapted to connect said first electric contacts (30) of said connection socket (16), the light emitting diodes (20) being positioned on a circuit board (22) and embedded in potting compound (28) within the housing (16) so that the light emitting domes of the light emitting diodes (20) project from a front surface of the potting compound.
8. An electrical display sign as claimed in Claim 7 including a generally tubular visor (12) extending forwardly of the light emitting diode cluster (14).
EP19900303218 1989-03-31 1990-03-27 Light emitting diode clusters for display signs Withdrawn EP0390479A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US33139089A 1989-03-31 1989-03-31
US331390 1989-03-31

Publications (2)

Publication Number Publication Date
EP0390479A2 true EP0390479A2 (en) 1990-10-03
EP0390479A3 EP0390479A3 (en) 1991-10-30

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EP19900303218 Withdrawn EP0390479A3 (en) 1989-03-31 1990-03-27 Light emitting diode clusters for display signs

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EP (1) EP0390479A3 (en)
DE (1) DE390479T1 (en)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0522248A1 (en) * 1991-07-10 1993-01-13 Rohm Co., Ltd. Light-emitting diode indicator and display panel using the same
FR2699647A1 (en) * 1992-12-19 1994-06-24 Bosch Gmbh Robert Lighting device, in particular for motor vehicles comprising several semiconductor light sources.
WO1997044613A1 (en) * 1996-05-23 1997-11-27 Siemens Aktiengesellschaft Lighting device for signalling, identification or marking
EP0858064A1 (en) * 1997-02-11 1998-08-12 Signature SA Sub-assembly for illuminated display and illuminated display screen using a juxtaposition of such sub-assemblies
KR100507710B1 (en) * 1996-05-23 2006-03-09 지멘스 악티엔게젤샤프트 Lighting device for signalling, identification or marking
US7180252B2 (en) 1997-12-17 2007-02-20 Color Kinetics Incorporated Geometric panel lighting apparatus and methods
KR100679763B1 (en) * 1996-05-23 2007-04-25 지멘스 악티엔게젤샤프트 Flush marker light
US7358929B2 (en) 2001-09-17 2008-04-15 Philips Solid-State Lighting Solutions, Inc. Tile lighting methods and systems
EP2181354A1 (en) * 2007-08-24 2010-05-05 Daktronics, Inc. Flexible pixel element fabrication and sealing method
US8106923B2 (en) 2004-10-14 2012-01-31 Daktronics, Inc. Flexible pixel hardware and method
US8344410B2 (en) 2004-10-14 2013-01-01 Daktronics, Inc. Flexible pixel element and signal distribution means

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Cited By (23)

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EP0522248A1 (en) * 1991-07-10 1993-01-13 Rohm Co., Ltd. Light-emitting diode indicator and display panel using the same
US5521587A (en) * 1991-07-10 1996-05-28 Rohm Co., Ltd. Light-emitting diode indicator and display panel using the same
FR2699647A1 (en) * 1992-12-19 1994-06-24 Bosch Gmbh Robert Lighting device, in particular for motor vehicles comprising several semiconductor light sources.
KR100507710B1 (en) * 1996-05-23 2006-03-09 지멘스 악티엔게젤샤프트 Lighting device for signalling, identification or marking
WO1997044613A1 (en) * 1996-05-23 1997-11-27 Siemens Aktiengesellschaft Lighting device for signalling, identification or marking
WO1997044614A1 (en) * 1996-05-23 1997-11-27 Siemens Aktiengesellschaft Lighting device for signalling, identification or marking
WO1997044612A1 (en) * 1996-05-23 1997-11-27 Siemens Aktiengesellschaft Lighting device for airports, in particular flush lighting
KR100679763B1 (en) * 1996-05-23 2007-04-25 지멘스 악티엔게젤샤프트 Flush marker light
WO1997044615A1 (en) * 1996-05-23 1997-11-27 Siemens Aktiengesellschaft Lighting device for signalling on and identification and marking of airport traffic areas
AU725815B2 (en) * 1996-05-23 2000-10-19 Adb Nv Flush-marker light
FR2759476A1 (en) * 1997-02-11 1998-08-14 Signature Sa LUMINOUS DISPLAY SUB-ASSEMBLY AND LUMINOUS DISPLAY SCREEN CONSTITUTED BY JUXTAPOSITION OF SUCH SUB-ASSEMBLIES
EP0858064A1 (en) * 1997-02-11 1998-08-12 Signature SA Sub-assembly for illuminated display and illuminated display screen using a juxtaposition of such sub-assemblies
US7180252B2 (en) 1997-12-17 2007-02-20 Color Kinetics Incorporated Geometric panel lighting apparatus and methods
US7358929B2 (en) 2001-09-17 2008-04-15 Philips Solid-State Lighting Solutions, Inc. Tile lighting methods and systems
US8106923B2 (en) 2004-10-14 2012-01-31 Daktronics, Inc. Flexible pixel hardware and method
US8344410B2 (en) 2004-10-14 2013-01-01 Daktronics, Inc. Flexible pixel element and signal distribution means
US8363038B2 (en) 2004-10-14 2013-01-29 Daktronics, Inc. Flexible pixel hardware and method
US8552928B2 (en) 2004-10-14 2013-10-08 Daktronics, Inc. Sealed pixel assemblies, kits and methods
US8552929B2 (en) 2004-10-14 2013-10-08 Daktronics, Inc. Flexible pixel hardware and method
US8604509B2 (en) 2004-10-14 2013-12-10 Daktronics, Inc. Flexible pixel element and signal distribution means
US9052092B2 (en) 2004-10-14 2015-06-09 Daktronics, Inc. Sealed pixel assemblies, kits and methods
EP2181354A1 (en) * 2007-08-24 2010-05-05 Daktronics, Inc. Flexible pixel element fabrication and sealing method
EP2181354A4 (en) * 2007-08-24 2011-05-18 Daktronics Flexible pixel element fabrication and sealing method

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