An electronic device may be provided with a display mounted in a housing. The display may have an array of pixels that form an active area and may have an inactive area that runs along an edge of the active area. A color ambient light sensor may gather ambient light measurements through a window in an opaque masking layer in the inactive area. The color ambient light sensor may have photodiodes with different spectral sensitivities and may have a dark current photodiode that is insensitive to light. A set of analog-to-digital converters may be used to digitize photodiode signals from the photodiodes. A switch array may be used to distribute signals from the photodiodes to each of the analog-to-digital converters. This allows the output of each photodiode to be averaged over multiple analog-to-digital converters to remove any impact of variations in performance between converters.

The arrangement comprises a filter region (10) filtering electromagnetic radiation and a shielding component (20) inhibiting propagation of electromagnetic radiation. The filter region comprises a central filter region (11) and a separate peripheral filter region (13). The shielding component comprises an aperture (21). The aperture is arranged above the central filter region. The central filter region and the peripheral filter region are optimized for different angles of incidence (α, β) and provided for measurements by individual sensor regions (18, 19).

According to one aspect, the invention relates to an angular optical filtering element (E.sub.i) optimized for angular filtering about a given operating angle of incidence (θ.sub.i, 1) in a given spectral band. The angular filtering element (E.sub.i) comprises a first nanostructured, band-pass, spectral filter (11.sub.i, 301) and a second nanostructured, band-pass, spectral filter (12.sub.i, 302). Each of the first and second spectral filters comprises, respectively, in said spectral band, a first and a second central filtering wavelength that respectively has a first and second angular dispersion curve defined depending on the angle of incidence (θ.sub.inc) on the optical filtering element (E.sub.i), the curves of angular dispersion being secant about the operating angle of incidence (θ.sub.i, 1) of the optical filtering element. The invention applies to the production of a selective angular filtering device and to a multidirectional optical detection system.

Disclosed herein is an ambient light sensor formed by a substrate, and an inner central area defined on the substrate, and a concentric polygonal shape defined on the substrate about the inner central area. The concentric polygonal shape is defined by concentric polygonal isolation regions and spoke shaped isolation regions extending through respective corners of the concentric polygonal isolation regions to the inner central area to thereby divide the concentric polygonal shape into a plurality of concentric polygonal regions, with each of the plurality of concentric polygonal regions divided into a plurality of trapezoidal sections. A plurality of photodiodes ae formed on the substrate such that each of the plurality of trapezoidal sections contains at least one photodiode. A color filter is applied to the plurality of trapezoidal sections and their respective photodiodes to thereby form a plurality of color channels.

Disclosed is a bio illuminance measuring apparatus including a circadian lambda filter passing external light along according to a circadian rhythm sensitivity curve, a visual lambda filter passing the external light along according to a visual sensitivity curve, a photo sensing portion sensing and converting the external light, which has passed through the circadian lambda filter, into a circadian wavelength signal and sensing and converting the external light, which has passed through the visual lambda filter, into a visual wavelength signal, and an illuminance calculating portion which calculates a ratio between the circadian wavelength signal and the visual wavelength signal, calculates a circadian action factor by applying the ratio between the circadian wavelength signal and the visual wavelength signal to a circadian action function which varies according to the visual wavelength signal, and calculates a bio illuminance value of the external light on the basis of the circadian action factor.

A meter for measuring UV light having wavelengths, preferably between 205 nm and 237 nm. The meter includes at least one UV sensitive photo diode adapted for detecting the wavelengths of UV light between a lower end and an upper end; a first filter that blocks the UV light having wavelengths below 237 nm down to at least the lower end that the UV sensitive photo diode can detect; a second filter that blocks the UV light having wavelengths above 230 nm up to at least 205 nm; at least one amplifier for amplifying a signal from the UV sensitive photo diode; an analog to digital converter; a microprocessor; a battery in electrical communication with the microprocessor. The microprocessor preferably being in communication with the amplifier and the analog to digital converter. The microprocessor provides a result for the UV light that the UV sensitive photo diode is exposed to.

A photodetector including: a case including a light receiving surface provided on an upper surface and having a first region that transmits visible light and a second region that transmits less visible light than the first region; a printed circuit board provided to face the light receiving surface; and a plurality of electronic components provided on a light receiving surface side of the printed circuit board and including a first light receiving element configured to detect visible light. The first light receiving element is disposed at a first position of the printed circuit board exposed to the visible light transmitted through the first region. The number of mounted electronic components disposed at the first position is smaller than the number of mounted electronic components disposed at a second position of the printed circuit board other than the first position.

In an example, an example article may include a spatially variant microreplicated layer optically coupled to a wavelength selective filter. The wavelength selective filter may have a light incidence angle-dependent optical band. The spatially variant microreplicated layer may be configured to transmit light to a first optical region of the wavelength selective filter at a first predetermined incidence angle and to a second optical region of the wavelength selective filter at a second predetermined incidence angle.

Disclosed herein is an illumination state monitoring apparatus, the illumination state monitoring apparatus, including a dual band pass filter having a first pass band in the visible wavelength area and having a second pass band in the infrared wavelength area, an optical sensor detecting light having passed through the dual band pass filter through a three primary color pixel and an infrared pixel, and a processor deducting an intensity value of a signal detected by the infrared pixel from an intensity value of a signal detected by the three primary color pixel, calculating an illuminance parameter, and determining an illumination state on the basis of the illuminance parameter, wherein sensitivity of the three primary color pixel toward light having passed through the second pass band and sensitivity of the infrared pixel toward light having passed through the second pass band are within a predetermined range.

Example systems and methods of UV disinfection of surfaces and/or air are presented which can utilize multiple peak wavelengths of UV light and utilize feedback control with UV light sensors. Some example systems and methods can facilitate sanitation of spaces which can be occupied by people and/or animals such as an interior room or space of a building or mode of transportation, or even an outdoor gathering space. Additionally, or alternatively, some example systems can include a compartment which is configured to block light exposure to people and/or animals during sanitation and into which objects can be placed for sanitation.