EP0899178A1 - Eisenbahnsignalleuchte auf Laserbasis - Google Patents

Eisenbahnsignalleuchte auf Laserbasis Download PDF

Info

Publication number
EP0899178A1
EP0899178A1 EP98306410A EP98306410A EP0899178A1 EP 0899178 A1 EP0899178 A1 EP 0899178A1 EP 98306410 A EP98306410 A EP 98306410A EP 98306410 A EP98306410 A EP 98306410A EP 0899178 A1 EP0899178 A1 EP 0899178A1
Authority
EP
European Patent Office
Prior art keywords
laser
signal light
light
fixture according
housing
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Withdrawn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
EP98306410A
Other languages
English (en)
French (fr)
Inventor
Joseph T. Verdeyen
Ronald W. Snee
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.)
Siemens Industry Inc
Original Assignee
Safetran Systems Corp
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 Safetran Systems Corp filed Critical Safetran Systems Corp
Publication of EP0899178A1 publication Critical patent/EP0899178A1/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B61—RAILWAYS
    • B61L—GUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC
    • B61L5/00—Local operating mechanisms for points or track-mounted scotch-blocks; Visible or audible signals; Local operating mechanisms for visible or audible signals
    • B61L5/12—Visible signals
    • B61L5/18—Light signals; Mechanisms associated therewith, e.g. blinders
    • B61L5/1809—Daylight signals
    • B61L5/1836—Daylight signals using light sources of different colours and separate optical systems
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B61—RAILWAYS
    • B61L—GUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC
    • B61L5/00—Local operating mechanisms for points or track-mounted scotch-blocks; Visible or audible signals; Local operating mechanisms for visible or audible signals
    • B61L5/12—Visible signals
    • B61L5/18—Light signals; Mechanisms associated therewith, e.g. blinders
    • B61L5/1809—Daylight signals
    • B61L5/1827—Daylight signals using light sources of different colours and a common optical system

Definitions

  • the present invention relates to railroad signal lights.
  • Such a signal light may be for use at railroad highway and pedestrian grade crossings, as flashing warning lights, and for railroad right-of-way control signals.
  • incandescent lamps have provided the light source for all railroad signal applications.
  • the incandescent lamp will have essentially uncoloured illumination, with the desired colour being provided by a colour filter.
  • a colour filter For example, for crossing gates and other warning devices there is typically a red colour filter, a light collecting device and a diverging lens.
  • red, yellow and green are the conventional colours, there will be filters to ensure that the proper colour of illumination is provided through the proper opening.
  • a laser light source has many advantages over an incandescent lamp as a source of light. Longer life is perhaps the most significant advantage. For example, present incandescent signal lights used by the railroad have a rated lifetime of approximately 2,000 hours, with 1,000 hours being a more common, realistic period of use. A laser light source may be rated at least as long as 10,000 hours and the accompanying electronics will have a much longer life. Moreover, a laser light source may be composed of an array of multiple lasers or multiple sources and since it is extremely unlikely that there would be a simultaneous failure of all such lasers, a more realistic situation would involve a slow degradation of the light source which can be monitored internally and a signal sent to railroad personnel and, when the light source reaches a predetermined level of illumination, the laser array can be replaced.
  • Another important advantage is that the coupling of a laser to a fibre is far more efficient than such a coupling to an incoherent source such as an incandescent lamp or an LED (light emitting diode).
  • an incoherent source such as an incandescent lamp or an LED (light emitting diode).
  • a laser light source is more easily directionalised and its amplitude can be easily controlled with low cost available semiconductor electronics. Laser light sources will operate at substantially higher electrical-to-light efficiencies than current, present-day incandescent lamps.
  • a railroad signal light fixture including: a housing; a signal light aperture in said housing; lens means covering said aperture; and a source of illumination within said housing to provide light directed through said lens means, said source of illumination being provided from a laser which provides for light within a specific colour spectrum.
  • the laser may provide for light in the red colour spectrum at a wavelength within the range of 630-680 nanometres; or light in the green colour spectrum at a wavelength in the range of 555 nanometres; or light in the yellow colour spectrum at a wavelength in the range of 588 nanometres.
  • the laser may be connected by a light conduit to a location positioned opposite said lens means.
  • the laser may be located remote from said housing, for example using a light conduit which is a fibre optic cable (for example a fibre optic cable doped with a rare earth material such as praseodymium).
  • said laser may be located within said housing.
  • the laser may be a laser diode which provides light within a specific colour spectrum.
  • the laser diode may be one of an array of such laser diodes.
  • Each of the laser diodes may be connected by a respective light conduit to a common location positioned opposite said lens means.
  • the signal light fixture could function as a crossing warning light or as a train control signal, for example.
  • each housing having a signal light aperture and lens means covering its aperture, there being such a source of illumination within each of said housings to provide light directed through the lens means of the housing, the source of illumination in each housing being provided from at least one laser which provides for light within a colour spectrum specific to that housing.
  • laser diodes are utilised as the light source for railway signals, both highway crossing flashing signal fixtures and railroad right-of-way train control fixtures, in the form of an array of such diodes as the light source.
  • the array may be located directly at the point of illumination or it may be remotely located and coupled by fibre optic cables to the point of illumination within the signal housing.
  • such an array of laser diodes may operate within the red colour spectrum of 630-680 nanometres (nm). Within this spectrum, the laser diodes will not all emit light at the same wavelength, but may emit a plurality of different wavelengths within this specific spectrum. For railroad right-of-way signals the array of laser diodes may operate near a wavelength of 588 nm for a yellow light and 555 nm for a green light. In the case of a "white” light requirement, one could use combinations of these colours to produce "white” or use two "complementary" colours, e.g.
  • a fibre optic cable doped with a rare earth which can be excited by very efficient near-infrared lasers to produce visible light of the appropriate wavelengths. This is accomplished by the sequential absorption of two infrared photons from the pumping lasers and the emission of visible photons from the excited rare earth atoms.
  • a particular appropriate rare earth is praseodymium.
  • a fibre optic cable doped with this material would utilize lasers at 1.01 ⁇ m and 835 nm to generate either 635 nm (red), 520 nm (green-blue) or 492 nm (blue) wavelengths of light.
  • Fig. 1 shows a typical prior art highway crossing flashing light signal fixture.
  • an outer housing 10 which may have an inner mirror coating 12.
  • the coating is placed on a parabolic reflector 14 and there is a colour filter and diverging lens 16 closing the aperture of the housing 10.
  • An incandescent light source 18 is positioned within the housing and will direct light along the paths of the arrows 20 out through the filter and diverging lens 16.
  • Such a light source is conventional and can be found throughout the United States wherever there are highway or pedestrian crossings of railroad tracks.
  • Fig. 2 illustrates a typical railroad right-of-way signal fixture.
  • a housing 30 which may be blackened on the inside so as to avoid light reflection.
  • the housing 30 has an aperture 32 and a light source 34 positioned within the housing.
  • a lens system which consists of an inner lens 36 and an outer lens 38, with the combination of the two lenses providing a means to direct the light from the signal source along a predetermined path, with only slight divergence in the beam over its useful length. This is important in that the signal light must be visible from a great distance and this can only come about if the light from the source is concentrated along a desired path.
  • a laser diode railroad signal light source is shown in Figs. 3 and 4. It may be useful in either a warning light environment or as a right-of-way signal.
  • a housing 40 which has a signal light aperture 42.
  • a lens system comprising an inner lens 44 and an outer lens 46, similar to the prior art lens structure of Fig. 2 is used in Fig. 4.
  • the source of illumination is provided from a plurality of laser diodes indicated at 48, 50, 52, 54 and 56 energised via a line 90 connected to a power source.
  • the number is only illustrative and specifically there may be anywhere from 15 to 20 such laser diodes and they may be spread in the wavelength spectrum, using red as an example of the desired colour, from 630-680 nanometres. For a green or yellow signal light, laser diodes in other spectrums would be utilised.
  • the laser diodes indicated at 48 and following are all connected into a light source array such as illustrated in Fig. 3 and located at an opening 58 within a wall 60 of the housing 40.
  • Fibre optic light transmissive conduits indicated at 62 connect each of the laser diode light sources into the bundle of light sources illustrated in Fig. 3.
  • One of the advantages of using laser diodes is that they can be located remotely from the signal housing by taking advantage of the superior coupling of a laser to a fibre optic cable and by the low loss characteristics of readily available fibre optic cables. For example, the loss for a ten metre length of fibre optic cable may be as low as 0.04 dB yielding a transmission factor of 99.08%.
  • an enclosure 64 which binds the light sources together in a closed array so that the effect is effectively a point source of light, which emits with a characteristic cone of radiation, as indicated by its numerical aperture, and emits at one or multiple wavelengths and which can be located at the focal point of the collimating optics.
  • the laser diodes as illustrated in Fig. 4 are within the signal housing, they may be remotely located therefrom, such as in a control box along the signal right-of-way or adjacent to a railroad highway crossing.
  • laser diodes are used as a light source as a source and the fact that even if one or more of the individual diodes within an array should go out, there is still adequate light from the array as a whole.
  • solid state sources for the electronic controls will contribute to the long life of such a signal light.
  • a further advantage to laser diodes is that each laser diode is specific to a particular wavelength and thus all of the light which emanates from the laser diode is at that wavelength. In contrast, in an incandescent lamp the light is spread throughout a wide portion of the light spectrum.
  • laser diodes are available with nominal wavelengths of 635, 650, 670, 640 nanometres.
  • Fig. 5 illustrates the use of a bundle of laser diodes at 70, with appropriate electrical connections 72, positioned in an aperture 74 within a signal light housing 76.
  • a diverging lens 78 is placed in front of the bundle 70 of laser diodes, after which the beam emanating from the diverging lens will be collimated by a lens 80. The end result will be a light beam along the path of arrows 82.
  • Fig. 6 is a perspective view of the laser bundle 70 and shows a plurality of individual laser diode light sources 84, all within a sheath or sleeve 86.
  • Fig. 7 shows a multiple of the housing 76 of Fig. 5 so as to provide a three-signal light source suitable for railroad right-of-way train control.
  • a three-signal light matrix there may be the typical red, green and yellow lights provided by the individual bundles of laser diodes, with the laser diodes functioning at the wavelengths described above.
  • the invention can encompass more than three specific signal lights and colours other than red, green and yellow, as required for train control.
  • laser diodes as a light source also permits the light source to be amplitude-modulated with simple and reliable electronics. This would have particular advantage in train control, as a receiver on a locomotive could be tuned to a particular modulation rate providing an electronic back up connection for train control in addition to the engineer's sighting of the visible signal.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Train Traffic Observation, Control, And Security (AREA)
  • Optical Communication System (AREA)
EP98306410A 1997-08-18 1998-08-11 Eisenbahnsignalleuchte auf Laserbasis Withdrawn EP0899178A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US91272797A 1997-08-18 1997-08-18
US912727 1997-08-18

Publications (1)

Publication Number Publication Date
EP0899178A1 true EP0899178A1 (de) 1999-03-03

Family

ID=25432338

Family Applications (1)

Application Number Title Priority Date Filing Date
EP98306410A Withdrawn EP0899178A1 (de) 1997-08-18 1998-08-11 Eisenbahnsignalleuchte auf Laserbasis

Country Status (5)

Country Link
EP (1) EP0899178A1 (de)
AU (1) AU7184798A (de)
CA (1) CA2243809A1 (de)
HR (1) HRP980428A2 (de)
ZA (1) ZA987324B (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6392553B1 (en) 2000-08-22 2002-05-21 Harmon Industries, Inc. Signal interface module
WO2013160072A3 (de) * 2012-04-23 2014-04-10 Siemens Aktiengesellschaft Lichtsignal

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2542220A1 (de) * 1975-09-22 1977-03-31 Siemens Ag Lichtsignal
WO1982002082A1 (en) * 1980-12-16 1982-06-24 Stensland Leif Fibre-optic lamp
WO1992020125A1 (en) * 1991-04-26 1992-11-12 The University Of Southampton Praseodymium doped waveguide lasers
US5563588A (en) * 1994-08-02 1996-10-08 Belfer; Bruce D. Fiber optic traffic signal light system having a shutter control

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2542220A1 (de) * 1975-09-22 1977-03-31 Siemens Ag Lichtsignal
WO1982002082A1 (en) * 1980-12-16 1982-06-24 Stensland Leif Fibre-optic lamp
WO1992020125A1 (en) * 1991-04-26 1992-11-12 The University Of Southampton Praseodymium doped waveguide lasers
US5563588A (en) * 1994-08-02 1996-10-08 Belfer; Bruce D. Fiber optic traffic signal light system having a shutter control

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6392553B1 (en) 2000-08-22 2002-05-21 Harmon Industries, Inc. Signal interface module
WO2013160072A3 (de) * 2012-04-23 2014-04-10 Siemens Aktiengesellschaft Lichtsignal

Also Published As

Publication number Publication date
HRP980428A2 (en) 1999-06-30
CA2243809A1 (en) 1999-02-18
AU7184798A (en) 1999-02-25
ZA987324B (en) 1999-02-16

Similar Documents

Publication Publication Date Title
US6796698B2 (en) Light emitting diode-based signal light
JP3980484B2 (ja) 赤外レーザダイオード式高輝度ライト
US7083315B2 (en) Elevated airfield runway and taxiway edge-lights utilizing light emitting diodes
US6350041B1 (en) High output radial dispersing lamp using a solid state light source
US6152588A (en) Addressable vehicular lighting system
DE102006029203B9 (de) Lichtemittierende Vorrichtung
US20080271777A1 (en) Method and apparatus for eye-safe transmittal of electrical power in vehicles using white light via plastic optical fiber
KR20090024280A (ko) 광섬유 도파로를 포함하는 배치
JP2006516494A (ja) 航空機位置灯
CN108235720A (zh) 用于产生高亮度光的光学设备
JP3236102U (ja) 照明アプリケーション用のレーザベースの導波路結合白色光システム
WO2013089103A1 (ja) 複数の導光部材を有する照射モジュール
EP2708808A1 (de) Optiksystem zur Verwendung in einer Ampelleuchte
US6850673B2 (en) Light source for fiber optics
US10422487B2 (en) Fiber optic light source
US9229145B2 (en) Lighting device
EP0899178A1 (de) Eisenbahnsignalleuchte auf Laserbasis
DE102012003815A1 (de) Beleuchtungssystem und Luftfahrthindernis
US20080259597A1 (en) Lighting Fixture Adapter
JP2013211252A (ja) 固体照明装置
CN110056808A (zh) 激光发光装置
KR960013483B1 (ko) 광섬유 조명기기 시스템
KR100516360B1 (ko) 발광 소자 어레이(array)장치 및 그 제조 방법
CN107002964B (zh) 用于机动车的前灯
Jaquet Plastic optical fiber applications for lighting of airports and buildings

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

AKX Designation fees paid
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19990906

REG Reference to a national code

Ref country code: DE

Ref legal event code: 8566