Light fixture

A few types of light fixtures

Ceiling light fixtures

A light fixture (US English), light fitting (UK English), or luminaire is an electrical device used to create artificial light by use of an electric lamp. All light fixtures have a fixture body and a light socket to hold the lamp and allow for its replacement. Fixtures may also have a switch to control the light. Fixtures require an electrical connection to a power source; permanent lighting may be directly wired, and moveable lamps have a plug. Light fixtures may also have other features, such as reflectors for directing the light, an aperture (with or without a lens), an outer shell or housing for lamp alignment and protection, and an electrical ballast or power supply. A wide variety of special light fixtures are created for use in the automotive lighting industry, aerospace, marine and medicine.

Portable light fixtures are often called "lamps", as in table lamp or desk lamp. In technical terminology, the lamp is the light source, what is typically called the light bulb.

The term luminaire is recommended by the International Electrotechnical Commission (IEC) for technical use.

History

Industrial light fixture, designed by Peter Behrens, around 1915

Fixture manufacturing began soon after production of the incandescent light bulb. When practical uses of fluorescent lighting were realized after 1924, the three leading companies to produce various fixtures were Lightolier, Artcraft Fluorescent Lighting Corporation, and Globe Lighting in the United States.^[1]

Fixture types

Light fixtures are classified by how the fixture is installed, the light function or lamp type.

Free-standing or portable

Tiffany dragonfly desk lamp with pigeon sculptures

• Table lamp fixtures, standard lamp fixtures, and office task light luminaires.
  • Balanced-arm lamp is a spot light with an adjustable arm such as anglepoise or Luxo L1.
  • Gooseneck lamp
  • Nightlight
• Floor Lamp
  • Torch lamp or torchières are floor lamps with an upward facing shade. They provide general lighting to the rest of the room.
  • Gooseneck lamp
• Bouillotte lamp: see Bouillotte

Fixed

• Ceiling Dome — Also called the light source(s) are hidden behind a translucent dome typically made of glass, with some combination of frosting and surface texturing to diffuse the light. These can be flush mount fixtures which are mounted right up against the ceiling, or semi-flush fixtures which are separated by a small distance (usually about 3-12").
  • Open ceiling dome — the translucent dome is suspended a short distance below the ceiling by a mechanism that is hidden with the exception of a screw-knob or other device appearing on the outer dome face, and pulling this knob releases the dome
  • Enclosed ceiling dome The translucent dome mates with a ring that is mounted flush with the ceiling
• Recessed light — the protective housing is concealed behind a ceiling or wall, leaving only the fixture itself exposed. The ceiling-mounted version is often called a downlight.
  • "Cans" with a variety of lamps — this term is jargon for inexpensive downlighting products that are recessed into the ceiling, or sometimes for uplights placed on the floor. The name comes from the shape of the housing. The term "pot lights" is often used in Canada and parts of the US.
  • Cove light — recessed into the ceiling in a long box against a wall.
  • Troffer — recessed fluorescent light fixtures, usually rectangular in shape to fit into a drop ceiling grid.

A chandelier light fixture

• Surface-mounted light — the finished housing is exposed, not flush with surface
  • Chandelier
  • Pendant light — suspended from the ceiling with a chain or pipe
  • Sconce — provide up or down lights; can be used to illuminate artwork, architectural details; commonly used in hallways or as an alternative to overhead lighting.
  • Track lighting fixture — individual fixtures ("track heads") can be positioned anywhere along the track, which provides electric power.
  • Under-cabinet light — mounted below kitchen wall cabinets
  • Display Case or Showcase light — shows merchandise on display within an enclosed case such as jewelry, grocery stores, and chain stores.
  • Ceiling fan - May sometimes have a light, often referred to as a light kit mounted to it.
  • Emergency lighting or exit sign — connected to a battery backup or to an electric circuit that has emergency power if the mains power fails
  • High- and low-bay lighting — typically used for general lighting for industrial buildings and often big-box stores
  • Strip lights or Industrial lighting — often long lines of fluorescent lamps used in a warehouse or factory

A decorative outdoor lamp at Leeds Town Hall.

A garden solar lamp is an example of landscape lighting

• Outdoor lighting and landscape lighting — used to illuminate walkways, parking lots, roadways, building exteriors and architectural details, gardens, and parks.
  • High-mast, usually pole- or stanchion-mounted — for landscape, roadways, and parking lots
  • Bollard — A type of architectural outdoor lighting that is a short, upright ground-mounted unit typically used to provide cutoff type illumination for egress lighting, to light walkways, steps, or other pathways.
  • Solar lamp
  • Street light
  • Yard light

Special-purpose lights

• Accent light — Any directional light which highlights an object or attracts attention to a particular area
• Background light — for use in video production
• Blacklight
• Christmas lights-also called fairy lights or twinkle lights and are often used at Christmas and other holidays for decoration.
• Flood light
• Safelight (for use in a darkroom)
• Safety lamp (for use in coal mines)
• Searchlight (for military and advertising use)
• Security lighting
• Step light
• Strobe light
• Task light
• Traffic light
• Theatrical
  • Stage lighting instrument
  • Intelligent lighting
  • Followspot
• Wallwasher

Lamp types

Old table lamps at Archaeological Museum, Sri Lanka

• Arc lamps

Xenon arc lamp, Yablochkov candle

• Fluorescent

Fluorescent lamp, compact fluorescent lamp (CFL), Induction lamp, blacklight.

• Fuel lamps

Betty lamp, butter lamp, carbide lamp, gas lighting, kerosene lamp, oil lamp, rush light, torch, candle, Limelight, gas mantle

Safety lamps: Davy lamp & Geordie lamp

• Gas-discharge lamp and high-intensity discharge lamp (HID)

Mercury-vapor lamp, Metal-halide (HMI, HQI, CDM), Sodium vapor or "high-pressure sodium"

• Neon sign

• Incandescent lamp

A-lamp, Parabolic aluminized reflector lamp (PAR), reflector lamp (R), bulged reflector lamp (BR) (refer to lamp shapes)

• Obsolete types: limelight, carbon button lamp, Mazda (light bulb), Nernst glower
• Novelty: Lava lamp
• Special purpose: heat lamp, Globar, gas mantle
• Halogen – special class of incandescent lamps

• Nuclear: self-powered lighting
• Plasma lamp
• Light-emitting diode (LED) (solid-state lighting)

Table Lighting

Light-fixture controls

• 3-way 2-circuit switch
• Dimmer
• Light switch (often part of the light socket or power cord on portable fixtures)
• Lighting control system
• Motion detector
• Timer
• Touch
• X10 (industry standard) systems

See also

• Architectural lighting design
• Coefficient of utilization
• Flashlight
• History of street lighting in the United States
• Lantern
• Lightbulb socket
• Lighting designer for the theater
• Luminous efficacy
• Timeline of lighting technology

References

1. "Early industry leaders", of fluorescent fixture manufacturing, Paul Levy (1998)

External links

• Look at the Chart and Pick Out the Reflector You Need, Popular Science, February 1919, page 75, Google Books