An approach for controlling ultraviolet intensity over a surface of a light sensitive object is described. Aspects involve using ultraviolet radiation with a wavelength range that includes ultraviolet-A and ultraviolet-B radiation to irradiate the surface. Light sensors measure light intensity at the surface, wherein each sensor measures light intensity in a wavelength range that corresponds to a wavelength range emitted from at least one of the sources. A controller controls the light intensity over the surface by adjusting the power of the sources as a function of the light intensity measurements. The controller uses the light intensity measurements to determine whether each source is illuminating the surface with an intensity that is within an acceptable variation with a predetermined intensity value targeted for the surface. The controller adjusts the power of the sources as a function of the variation to ensure an optimal distribution of light intensity over the surface.

A daylight sensor for automated window-shading applications that incorporates at least one (and optionally more than one) of three aspects: an optimized Field-of-View (FOV), angle-diversity sensing (via at least two sub-sensors with different FOVs, whose outputs are processed in a particular way to yield the overall sensor output), and multi-spectral sensing (via at least two sub-sensors with differing spectral responses and, optionally, different FOVs, whose outputs are processed in a particular way to yield the sensor output). These aspects improve the correlation between the sensor output and the subjectively-perceived daylight level (especially under glare-inducing conditions, such as in the presence of low-angle direct sunlight), thereby enabling more effective automatic control of daylight admitted into a room.

A diamond identification apparatus is disclosed, the diamond identification apparatus comprising a support platform for receiving a gemstone at an observation position, a first light source arranged to emit light at a predetermined angle towards the observation position and a first photodiode arranged to detect an amount of light from the first light source being reflected from the gemstone at the observation position. The diamond identification apparatus further comprises a second light source arranged to emit light towards the observation position, a second photodiode arranged to detect light from the second light source that passes through the gemstone at the observation position and a processor unit.

A diamond identification apparatus is disclosed, the diamond identification apparatus comprising a support platform for receiving a gemstone at an observation position, a first light source arranged to emit light at a predetermined angle towards the observation position and a first photodiode arranged to detect an amount of light from the first light source being reflected from the gemstone at the observation position. The diamond identification apparatus further comprises a second light source arranged to emit light towards the observation position, a second photodiode arranged to detect light from the second light source that passes through the gemstone at the observation position and a processor unit.

A diamond identification apparatus is disclosed, the diamond identification apparatus comprising a support platform for receiving a gemstone at an observation position, a first light source arranged to emit light at a predetermined angle towards the observation position and a first photodiode arranged to detect an amount of light from the first light source being reflected from the gemstone at the observation position. The diamond identification apparatus further comprises a second light source arranged to emit light towards the observation position, a second photodiode arranged to detect light from the second light source that passes through the gemstone at the observation position and a processor unit.

Provided are an optical receiver that can realize a reduction in the variation of sensitivity in the ultraviolet light region and a reduction in noise in the visible light region and the infrared light region, a portable electronic device, and a method of producing an optical receiver. The first light-receiving device (PD1) and the second light-receiving device (PD2) of the optical receiver (1) are each constituted by forming a second conductivity-type N-type well layer (N_well) on a first conductivity-type P-type substrate (P_sub), forming a first conductivity-type P-type well layer (P_well) in the N-type well layer (N_well), and forming a second conductivity-type N-type diffusion layer (N) in the P-type well layer (P_well). The P-type substrate P_sub, the N-type well layer (N_well), and the P-type well layer (P_well) are electrically at the same potential or are short-circuited.

A diamond identification apparatus is disclosed, the diamond identification apparatus comprising a support platform for receiving a gemstone at an observation position, a first light source arranged to emit light at a predetermined angle towards the observation position and a first photodiode arranged to detect an amount of light from the first light source being reflected from the gemstone at the observation position. The diamond identification apparatus further comprises a second light source arranged to emit light towards the observation position, a second photodiode arranged to detect light from the second light source that passes through the gemstone at the observation position and a processor unit.

An approach for controlling ultraviolet intensity over a surface of a light sensitive object is described. Aspects involve using ultraviolet radiation with a wavelength range that includes ultraviolet-A and ultraviolet-B radiation to irradiate the surface. Light sensors measure light intensity at the surface, wherein each sensor measures light intensity in a wavelength range that corresponds to a wavelength range emitted from at least one of the sources. A controller controls the light intensity over the surface by adjusting the power of the sources as a function of the light intensity measurements. The controller uses the light intensity measurements to determine whether each source is illuminating the surface with an intensity that is within an acceptable variation with a predetermined intensity value targeted for the surface. The controller adjusts the power of the sources as a function of the variation to ensure an optimal distribution of light intensity over the surface.