The angle that a reflected ray makes with a normal to a reflecting surface at the point of incidence

The principle that when light or sound is reflected from a smooth surface, the angle of incidence is equal to the angle of reflection, and the incident ray, the reflected ray, and the normal to the surface all lie in the same plane

The angle that a refracted ray makes with a normal to the interface between two media at the point of incidence

A device for maintaining the current through a fluorescent or HID lamp at the desired constant value, and sometimes also providing the required starting voltage and current

A device used with a ballast to provide the starting voltage for a pre-heat fluorescent lamp

Any of a number of substances that emit light when excited by radiation

A phosphor having peaks in three specific color regions, red, blue, and green, used to improve the color rendering of a fluorescent lamp

The emission of radiation esp. of visible light, by a substance during exposure to external radiation

The temperature at which a blackbody emits light of a specified spectral distribution, used to specify the color of a light source

A curve plotting the radiant energy in each wavelength of a particular source

A measure of the ability of an electric lamp to render color accurately when compared with a reference light source of similar color temperature

A doughnut-shaped fluorescent lamp for circular luminaires

A U-shaped fluorescent lamp for square or rectangular luminaires

Any of various small, improved efficiency fluorescent lamps having a single, double, U-shaped, or spiral tube, and either an Edison screw base or an adapter fitting an incandescent lampholder

A lamp in which light is produced by the discharge of electricity between electrodes in a gas-filled glass enclosure

A tubular discharge in which light is produced by the fluorescence of phosphors coating the inside of the tube

A cold-cathode lamp emitting a glow when a high voltage is applied across two electrodes in a neon-filled glass tube

A high-intensity discharge lamp producing light by means of an electric discharge in mercury vapor

A high-intensity discharge lamp producing light by means of an electric discharge in sodium vapor

A fluorescent lamp that requires a separate starter to preheat the cathodes before opening the circuit to the starting voltage

A fluorescent lamp designed to operate with a ballast having a low-voltage winding for continuous heating of the cathodes, which allows the lamp to be started more rapidly than a preheat lamp

A fluorescent lamp designed to operate with a ballast having a high-voltage transformer to initiate the arc directly without any preheating of the cathodes

A rapid-start fluorescent lamp designed to operate on a current of 800 milliamperes, resulting in a corresponding increase in luminous flux per unit length of lamp

A rapid-start fluorescent lamp designed to operate on a current of 1500 milliamperes, providing a corresponding increase in luminous flux per unit length of lamp

A discharge lamp having cathodes that emit electrons without having to be heated

A discharge lamp in which a significant amount of light is produced by the discharge of electricity through a metallic vapor in a sealed glass enclosure

A sodium lamp producing a yellow, glare-less light and used esp. to illuminate roadways

A sodium lamp producing broader-spectrum, golden-white light than a low-pressure sodium lamp

A high-intensity discharge lamp similar in construction to a mercury lamp, but having an arc tube to which various metal halides are added to produce more light and improve color rendering

A semiconductor device consisting of two materials, one having a surplus of positive charge and the other a surplus of negative charge that, when combined at a junction, releases light energy as a forward voltage is applied

A surface for reflecting light, heat, or sound, esp. the device on a luminaire having such a surface for controlling the distribution of light emitted by a lamp

A piece of transparent material, such as glass or plastic, having two opposite surfaces either or both of which are curved, used in luminaires to focus, disperse, or collimate the emitted light

The light provided by light-emitting diode (LED) lamps in various form factors

An LED lamp designed to be interchangeable with incandescent and halogen lamps in existing luminaires, consisting of a group or cluster of high power LEDs housed in standard bulb shapes with bases that fit normal sockets

A power supply designed to deliver constant current source for LED lamps over a range of load voltages

An LED lamp designed to serve as a replacement for traditional T8/T10/T12 fluorescent tubes

A solid-state, low-voltage electric lamp that uses light-emitting diodes (LED) as the source of light

A fully assembled light fixture utilizing LED lamps and equipped with a compact LED driver for connecting to 110 to 240 V power sources

A flexible or rigid linear module with very low profile, surface-mounted LEDs, used for edge lighting, display lighting, and core lighting

A lighting unit consisting of one or more electric lamps with all of the necessary parts and wiring for positioning and protecting the lamps, connecting the lamps to a power supply, and distributing the light

A reflector having a parabolic surface to spread or focus the rays from a light source, depending on the location of the source

To make rays of light parallel

A reflector having an elliptical surface to focus the rays from a light source

A lens having concentric, prismatic grooves to concentrate light from a small source

A lens having a multi-faceted surface with parallel prisms to redirect the rays from a light source

A series of circular ridges for reducing the brightness of a light source at an aperture

Any of a variety of translucent materials for filtering glare from a light source and distributing the light over an extended area

A finned or vaned device for controlling the radiation from a light source

A louvered construction divided into cell-like areas and used for redirecting the light emitted by an overhead source

A louvered device shielding a light source from view at certain angles

The angle below which a light source can be seen

The ratio of luminous flux emitted by a luminaire to the total flux emitted by the lamps in the luminaire