US4488207A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Static multi-color light signal
Assignee: Hitachi Rail STS USA Inc
•
Filing: 1983-08-18
•
Granted: 1984-12-11
•
Expires: 2003-08-18
Abstract
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.
Inventors
- 👤 Kevin E. Harmon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:04
CPC Classifications
G; G02; G02F; G02F1/00; G08; G08G; G08G1/00; G08G1/09; G08G1/095; F; F21; F21W; F21W2111/00
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
114 words
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.
Claim 2
Dependent Claim
114 words
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.
Claim 3
Dependent Claim
21 words
The multi-color signal light unit, as defined in claim 1, wherein said lamp includes a halogen lamp which emits "white light".
Claim 4
Dependent Claim
31 words
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.
Claim 5
Dependent Claim
18 words
The multi-color light signal unit, as defined in claim 1, wherein said lens includes a diverging meniscus lens.
Claim 6
Dependent Claim
19 words
The multi-color light signal unit, as defined in claim 1, wherein said parabolic mirror includes a multi-faceted reflective surface.
Claim 7
Dependent Claim
28 words
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.
Claim 8
Dependent Claim
28 words
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.
Claim 9
Dependent Claim
28 words
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.
Claim 10
Dependent Claim
19 words
The multi-color light signal unit, as defined in claim 1, wherein said dichroic filters transmit the red light rays.
Claim 11
Dependent Claim
19 words
The multi-color light signal unit, as defined in claim 1, wherein said dichroic filter reflects the green light rays.
Claim 12
Dependent Claim
22 words
The multi-color light signal unit, as defined in claim 1, wherein said respective dichroic filters reflect and transmit the yellow light rays.
Claim 13
Dependent Claim
148 words
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.
Claim 14
Dependent Claim
148 words
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.
Claim 15
Dependent Claim
28 words
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.
Claim 16
Dependent Claim
138 words
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.
Claim 17
Dependent Claim
138 words
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.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-12-11 | 1988-06-11 | 1988-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-11 | 1992-06-11 | 1992-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-11 | 1996-06-11 | 1996-12-11 | $7700.00 | Window Closed / Lapsed |