Abstract:
A novel standard light source with a more simplified construction, which is suitable for measurement of total luminous flux of a light source different in luminous intensity distribution characteristics from a conventional standard light source, and a measurement method with the use of that standard light source are provided. A standard light source includes a light emitting portion, a power feed portion electrically connected to the light emitting portion, and a restriction portion provided between the light emitting portion and the power feed portion, for restricting propagation of light radiated from the light emitting portion toward the power feed portion. A surface of the restriction portion on which light from the light emitting portion is incident is constructed for diffuse reflection.
Abstract:
A radiation detector, including a photodiode, has improved uniformity of sensitivity over the field of view because the receiving surface is provided by an optical diffusing layer, and the field of view is defined by a baffle arrangement, each internal surface of which is reflective. The baffle arrangement also defines a volume and the diffusing layer conforms to a part of the volume adjacent to the apex thereof. The diffusing layer may be provided by material, initially in liquid form, solidified in situ within the baffle arrangement. The receiving surface may be provided within a receiving head of the detector, spaced from the photodiode. Radiation may be transmitted from the receiving surface, whether part of a separate receiving head or not, to the photodiode by an optical fibre. An assembly of four constituent detectors, each having three orthogonally arranged mirrors, may together define a hemispherically shaped volume.
Abstract:
There is provided a light automatic ON/OFF control device 1 that prevents botheration and strange feelings caused by an ON/OFF operation of a head light 50 by an influence of black clouds or white clouds in a visual field range of an illuminance sensor. A forward illuminance sensor 12 for detecting illuminance forward of a vehicle and an upward illuminance sensor 14 for detecting illuminance upward of the vehicle, wherein when the output of both the illuminance sensors 12, 14 is smaller than an ON illuminance threshold, the head light switches on, and when equal to or more than an OFF illuminance threshold higher than the ON illuminance threshold, the head light switches off. Particularly since the visual field range of the upward illuminance sensor 14 is set to an angle of 45° or more, which is wider than that of the conventional visual field range, even if white clouds or black clouds appear above, an area ratio shown by these clouds within the visual field range of the upward illuminance sensor becomes small. Therefore the influence is reduced and the output of the upward illuminance sensor 14 does not cross the ON illuminance threshold or the OFF illuminance threshold. Accordingly an ON state or an OFF state of the head light does not change to prevent a temporal ON/OFF operation thereof.
Abstract:
Demultiplexing systems and methods are discussed which may be small and accurate without moving parts. In some cases, demultiplexing embodiments may include optical filter cavities that include filter baffles and support baffles which may be configured to minimize stray light signal detection and crosstalk. Some of the demultiplexing assembly embodiments may also be configured to efficiently detect U.V. light signals and at least partially compensate for variations in detector responsivity as a function of light signal wavelength.