Light emitting apparatus having variable beam angle and fixed central beam candlelight power

Abstract

The invention provides a light emitting apparatus. The light emitting apparatus includes: a light source; an electronic driver for driving the light source to emit light; a light beam shaping elementused for shaping a light beam of light emitted by the light source; a beam angle adjustment mechanism configured to change a positional relationship between the light source and the beam shaping element; and a sensor configured to provide a signal indicative of a setting of the beam angle adjustment mechanism. The electronic driver is configured to adjust the luminous flux emitted by the light source according to a signal provided by the sensor. The light emitting apparatus can keep the candlelight power of the central light beam of the emitted light constant when the angle of the light beam is changed.

Description

technical field

[0001] The present invention relates to luminaires with variable beam angle and fixed center beam candle power. Background technique

[0002] Two important parameters of lighting equipment are the beam angle at which the light is emitted and the central beam candlepower (CBCP). Center beam candela power is the luminous intensity along the geometric centerline of a directional light source. Usually, the center beam candlepower (also often written as center beam candlepower) is also the maximum candlepower. Center beam candela power is also known as center beam intensity.

[0003] In luminaires with a fixed beam angle, the CBCP is usually also fixed.

[0004] In luminaires with variable beam angles, the CBCP typically changes when the beam angle changes. For example, as the beam angle increases, the same amount of light is distributed over a larger solid angle, resulting in a decrease in CBCP. For the workplace, this can be especially undesirable. On the ...

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