240 results about "Uv detector" patented technology

An ultraviolet (UV) detector for detecting and verifying the authenticity of documents placed therein and exposed to ultraviolet light and ambient (white light) backlighting. The UV detector includes a detector housing, and a viewing chamber having a viewing mirror mounted therein for viewing documents. The detector housing also includes a document insertion slot for inserting documents into the viewing chamber adjacent to the viewing mirror. The detector housing further includes an LED holder for holding one or more LED's therein to provide a source of UV light in the viewing chamber which is transmitted to the viewing mirror and to the documents for identifying UV activated features on the documents, including UV holographic images and / or UV activated inks on the documents that are illuminated. The user looks into the viewing chamber for viewing the UV activated features on the viewing mirror. Additionally, the detector housing includes a translucent member disposed therein for diffusing visible white light. The UV detector includes a printed circuit board (PCB) for holding at least one LED to provide a source of visible white light in the detector housing which is transmitted to the translucent member for diffusing the visible white light for identifying watermarks on the documents that are illuminated. The user looks into the viewing chamber at the viewing mirror which reflects the identified watermarks to the user. Also, the placement of the viewing mirror increases the illumination area of the 365 nm UV light source in order to reduce the size of the detector housing.

A UV absorption spectrometer includes a housing, a controller, and a sensor unit including an ultraviolet light source, an analytical area in an analytical cell or in running water or gaseous medium, and an UV wavelength separator including a UV detector. An ultraviolet light in a wavelength range of 200-320 nm emits from the light source through the analytical area to the wavelength separator, and the controller transforms output signals from the UV detector into absorbance values or optical densities for two or more wavelengths in the wavelength range, calculates differences of said absorbance values or optical densities, determines a concentration of a chemical in the solution with calibration constants found for a known concentration of the chemical and said differences of said absorbance values or optical densities.

The invention belongs to the field of semiconductor optoelectronic detectors, in particular relates to a back incident-type UV detector with quartz as a substrate, nano-TiO2 thin film as a basic UV detection material and Ni as a metal electrode, and a preparation method thereof. The detector takes the quartz as the substrate and adopts an M-S-M (metal-semiconductor-metal) structure. The method for manufacturing the UV detector comprises the steps of adopting a sol-gel technique to grow a TiO2 nanometer thin film on the quartz substrate, evaporating a layer of thin Ni on the prepared TiO2 thin film by a magnetron sputtering method to achieve electrode contact, and adopting lithography technology to obtain Ni inserted-finger shape electrodes. The UV detector in an MSM planar double schottky barrier structure adopts a back incident-type working mode and can greatly improve responsiveness. The detector has good detection performance for the UV rays 250 to 350 nm in wavelength.

The invention discloses a fire hazard alarm safety protection system and method based on a UV and image detection technology. Detected UV radiation data of a monitored area is received, the safety state of the monitored area is pre-determined, and whether UV waveband data carried by flames exist is determined; and image data of the monitored area and a UV data analysis results are received, when it is determined that the UV waveband data carried by the flames exist, the image data is identified, and whether a fire hazard is generated is determined. A UV detector and a monitoring pick-up head are compounded together, under a normal condition, the monitoring pick-up head only carries out normal safety monitoring work, and an image identification algorithm is not started for secondary determination unless the UV detector detects fire hazard signals. A two-stage fire hazard detection mechanism is employed, the correct rate of fire hazard identification is improved, useless calculation of a computer is also reduced, and waste of resources is avoided.

An ultraviolet light sensor includes an elongated metal oxide nanostructure, a layer of an ultraviolet light-absorbing polymer, a current source and a current detector. The elongated metal oxide nanostructure has a first end and an opposite second end. The layer of an ultraviolet light-absorbing polymer is disposed about at least a portion of the metal oxide nanostructure. The current source is configured to provide electrons to the first end of the metal oxide nanostructure. The current detector is configured to detect an amount of current flowing through the metal oxide nanostructure. The amount of current flowing through the metal oxide nanostructure corresponds to an amount of ultraviolet light impinging on the metal oxide nanostructure.

The invention discloses a UV detector with a non-polar absorption layer, which comprises the following elements arranged from the bottom to the top in a successive manner: a substrate, an AlN intermediate layer, an un-doped AlGaN buffer layer, an n-type AlGaN layer and a non-polar AlxGa1-xN / AlyGa1-yN multiple quantum well absorption and isolation layer, an un-doped ALzGa1-zN multiplier layer, p-type AlGaN layer, a p-type Ohmic electrode provided on the p-type AlGaN layer, an n-type Ohmic electrode arranged on the n-type AlGaN layer, where the AlxGa1-xN / AlyGa1-yN multiple quantum well is used as the absorption layer of the UV detector. The beneficial effects of the present invention are: to fundamentally prevent the polarized electric field in the absorption layer from compensating the built-in electric field in the p-n junction and to improve the photocurrent of the ultraviolet detector; in addition, the use of the non-polar AlxGa1-xN / AlyGa1-yN multiple quantum well as the absorption layer of the UV detector can further enhance the UV absorption coefficient and lateral carrier mobility of the UV detector due to the action of the quantum effect and plays an important role in raising the quantum efficiency and the sensitivity of the UV detector.