Static multi-color light signal

• US 4,488,207 A
• Filed: 08/18/1983
• Issued: 12/11/1984
• Est. Priority Date: 08/18/1983
• Status: Expired due to Term

• Current Assignee: Union Switch & Signal, Inc. (Hitachi, Ltd.)
• Original Assignee: American Standard Inc. (Trane Technologies plc)
• Inventors: Harmon, Kevin E.
• Primary Examiner(s): Lechert, Jr., Stephen J.
• Application Number:
  US06/524,255
• Time in Patent Office: 481 Days
• Field of Search: 362/231, 362/236, 362/240, 362/241, 362/263, 362/268, 362/293, 362/307, 362/308, 362/310, 362/311, 362/362, 362/375, 362/331
• US Class Current: 362/231
• CPC Class Codes: F21W 2111/00 Use or application of lighting devices or systems for signalling, marking or indicating, not provided for in codes F21W2102/00 – F21W2107/00
• CPC Class Codes: G08G 1/095 Traffic lights

Abstract

A static-type of multi-color searchlight signal for displaying one of a plurality of color signals including a plurality of parabolic reflectors, each having a focal point at which an associated "white light" source is located so that light rays are collected and reflected in a substantially parallel configuration, a plurality of color filters, one of which is disposed in front of each one of the plurality of parabolic reflectors for passing a given color of the parallel light rays and for absorbing all other colors, a plurality of dichroic filters situated in the optical path of the passed parallel light rays and having an angle of incidence which corresponds to the angle of incidence of the passed parallel light rays, and a lens system for projecting the passed parallel light rays for providing a color signal aspect.

Claims

1. A multi-color light signal unit comprising, at least one lamp for producing light rays, at least one parabolic mirror for reflecting the light rays in a substantially parallel orientation to the axial ray, at least one color filter for transmitting specific wavelengths of the light rays and for reflecting or absorbing all other wavelengths of the light, and at least one inclined dichroic filter of selected angle of incidence for receiving the passed wavelengths of the light at substantially the same angle of incidence as the angle of incidence of the dichroic filter and for conveying the passed wavelengths of the light onto a lens system which projects a signal light of homogeneous hue.

2. The multi-color signal light unit, as defined in claim 1, wherein said lamp includes a halogen lamp which emits "white light".

3. The multi-color signal light unit, as defined in claim 1, wherein said inclined dichroic filter is disposed at a forty-five degree angle with respect to the focal axis of said lens.

4. The multi-color light signal unit, as defined in claim 1, wherein said lens includes a diverging meniscus lens.

5. The multi-color light signal unit, as defined in claim 1, wherein said parabolic mirror includes a multi-faceted reflective surface.

6. The multi-color light signal unit, as defined in claim 1, wherein said color filter passes specified range of red light rays and absorbs all other color light rays.

7. The multi-color light signal unit, as defined in claim 1, wherein said color filter passes specified range of green light rays and absorbs all other color light rays.

8. The multi-color light signal unit, as defined in claim 1, wherein said color filter passes specified range of yellow light rays and absorbs all other color light rays.

9. The multi-color light signal unit, as defined in claim 1, wherein said dichroic filters transmit the red light rays.

10. The multi-color light signal unit, as defined in claim 1, wherein said dichroic filter reflects the green light rays.

11. The multi-color light signal unit, as defined in claim 1, wherein said respective dichroic filters reflect and transmit the yellow light rays.

12. A searchlight light for projecting a select one of a plurality of color signals comprising, a plurality of parabolic reflectors, each having a focal point at which an associated "white light" source is located so that light rays are collected and reflected in a substantially parallel configuration, a plurality of different color filters, one of which is disposed in front of each one of said plurality of parabolic reflectors for passing a given color of the parallel light rays and for absorbing all other colors, a plurality of dichroic filters, each having a preselected angle of incidence, said plurality of dichroic filters situated in the optical path of the passed parallel color light rays and disposed at an angle which substantially corresponds to the angle of incidence so that the passed parallel color light rays remain within the selected chromaticity range, and lenses for projecting the selected colors.

13. The searchlight signal, as defined in claim 12, wherein one of said dichroic filters reflects yellow and lower wavelength light rays and transmits all higher wavelength light rays.

14. A searchlight signal comprising, a plurality of parabolic reflectors, each having a focal point at which an associated "white light" source is located so that the light rays are collected and reflected in substantially a parallel configuration, a plurality of different color filters, one of which is disposed in front of each of said parabolic mirrors to pass a given color of the parallel light rays and to absorb all other colors, a plurality of inclined dichroic filters situated in the optical path of the passed parallel color light rays, each of said plurality of dichroic filters having a selected angle of incidence which corresponds to the angle of incidence at which the passed parallel color light rays strike each of said plurality of dichroic filters, and a lens system for projecting the passed parallel color light rays.