GB619084A - Light refracting and transmitting plates and equipment using the same - Google Patents

Light refracting and transmitting plates and equipment using the same

Info

Publication number
GB619084A
GB619084A GB3384446A GB3384446A GB619084A GB 619084 A GB619084 A GB 619084A GB 3384446 A GB3384446 A GB 3384446A GB 3384446 A GB3384446 A GB 3384446A GB 619084 A GB619084 A GB 619084A
Authority
GB
Grant status
Application
Patent type
Prior art keywords
light
refractor
degrees
vertical
plane
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.)
Expired
Application number
GB3384446A
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.)
Holophane Co Inc
Original Assignee
Holophane Co 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

Links

Classifications

    • 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
    • F21V5/00Refractors for light sources
    • F21V5/02Refractors for light sources of prismatic shape

Abstract

619,084. Refractors for rectilinear light sources. HOLOPHANE, Ltd. (Holophane Co., Inc.). Nov. 14, 1946, No. 33844. [Classes 75 (ii) and 75 (iv)] A refractor plate for use in lighting apparatus for preventing the emission of light in unwanted directions is of generally uniform thickness and has a plane first surface 23, Fig. 5, and a light transmitting second surface formed with symmetrical prismatic elements having plane sides 36, 36<1>, or with contiguous conical prismatic elements (not shown), the angle P which the sides 36, 361, or the sides of the conical elements, make with the plane 23 being substantially equal to 2/y (90 degrees - C), where C is the critical angle of the medium of which the refractor is made and y is an odd integer greater than one. The plate shown is of glass having a refractive index of 1.5 and a critical angle of 42 degrees, and the angle P, given by the above formula when y=3, is 32 degrees. No rays are transmitted at angles to the vertical higher than that of the ray 28 which is 47 degrees to the vertical. Fig. 12 shows a refractor 90 for use with a rectilinear light source mounted along the aisle of a railway coach and provided on its upper surface with longitudinally extending prisms 92 which spread light away from the vertical and light depressing prisms 93 which lower the light to produce two generally divergent light beams directed towards the seats. Transverse prisms 98 constructed in accordance with the invention are provided on the lower surface of the refractor extending 30 degrees approximately each side of the vertical central plane through the light source, so that the rays at high angles to the vertical are not emitted through the longitudinal central portion of the refractor.
GB3384446A 1946-11-14 1946-11-14 Light refracting and transmitting plates and equipment using the same Expired GB619084A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB3384446A GB619084A (en) 1946-11-14 1946-11-14 Light refracting and transmitting plates and equipment using the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3384446A GB619084A (en) 1946-11-14 1946-11-14 Light refracting and transmitting plates and equipment using the same

Publications (1)

Publication Number Publication Date
GB619084A true true GB619084A (en) 1949-03-03

Family

ID=10358176

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3384446A Expired GB619084A (en) 1946-11-14 1946-11-14 Light refracting and transmitting plates and equipment using the same

Country Status (1)

Country Link
GB (1) GB619084A (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1101318B (en) * 1956-12-10 1961-03-09 Holophane Ltd Translucent, light-refracting plate
US3179793A (en) * 1962-01-17 1965-04-20 Holophane Co Inc Street lighting luminaires
US4660131A (en) * 1979-06-08 1987-04-21 Peerless Lighting Corporation Method for indirect lighting
US4667275A (en) * 1979-06-08 1987-05-19 Peerless Lighting Corporation Luminaire for indirect lighting
USRE33471E (en) * 1979-06-08 1990-12-04 Peerless Lighting Corporation Method for indirect lighting
USRE33593E (en) * 1979-06-08 1991-05-21 Peerless Lighting Corporation Luminaire for indirect lighting
EP0588504A1 (en) * 1992-09-16 1994-03-23 International Business Machines Corporation A backlight device for a liquid crystal display device
WO1996017205A1 (en) * 1994-11-30 1996-06-06 Honeywell Inc. Prismatic refracting optical array for liquid flat panel crystal display backlight

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1101318B (en) * 1956-12-10 1961-03-09 Holophane Ltd Translucent, light-refracting plate
US3179793A (en) * 1962-01-17 1965-04-20 Holophane Co Inc Street lighting luminaires
US4660131A (en) * 1979-06-08 1987-04-21 Peerless Lighting Corporation Method for indirect lighting
US4667275A (en) * 1979-06-08 1987-05-19 Peerless Lighting Corporation Luminaire for indirect lighting
USRE33471E (en) * 1979-06-08 1990-12-04 Peerless Lighting Corporation Method for indirect lighting
USRE33593E (en) * 1979-06-08 1991-05-21 Peerless Lighting Corporation Luminaire for indirect lighting
EP0588504A1 (en) * 1992-09-16 1994-03-23 International Business Machines Corporation A backlight device for a liquid crystal display device
WO1996017205A1 (en) * 1994-11-30 1996-06-06 Honeywell Inc. Prismatic refracting optical array for liquid flat panel crystal display backlight
US5579134A (en) * 1994-11-30 1996-11-26 Honeywell Inc. Prismatic refracting optical array for liquid flat panel crystal display backlight

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