32results about How to "Reduce afterglow" patented technology

Hafnium oxide HfO₂ scintillator compositions are doped with titanium oxide and at least an oxide of a metal selected from the group consisting of Be, Mg, and Li. The scintillator compositions can include sintering aid material such as scandium and/or tin and a rare earth metal and/or boron for improved transparency. The scintillators are characterized by high light output, reduced afterglow, short decay time, and high X-ray stopping power. The scintillators can be used as detector elements in X-ray CT systems.

Scintillator compositions having a garnet crystal structure useful for the detection of high-energy radiation, such as X, beta, and gamma radiation, contain (1) at least one of terbium and lutetium; (2) at least one rare earth metal; and (3) at least one of Al, Ga, and In. Terbium or lutetium may be partially substituted with Y, La, Gd, and Yb. In particular, the scintillator composition contains both terbium and lutetium. The scintillators are characterized by high light output, reduced afterglow, short decay time, and high X-ray stopping power.

The back scatter detector is one truncated rectangular pyramid structure comprising one bottom plane, one top plane and four side planes to form one sealed casing. The bottom plane as the X-ray incident window has outer layer of aluminum-plastic board and inner layer of barium fluorochloride screen; and the top plane and the four side planes have transparent flash cesium iodide crystal sheets adhered to the inner surface and mounted photomultipliers. The present invention has barium fluorochloride layer to absorb low energy X-rays and transparent cesium iodide crystal sheets to absorb high energy X-rays, and this can greatly reduce afterglow, raise the X-ray absorbing efficiency and raise light converting efficiency.

To provide a circuit for reducing an afterglow of secondary light, a circuit includes an LED (11) which includes an LED chip (13) and a KSF phosphor (15), and a first output circuit (5) and a second output circuit (6) which are coupled to a cathode (11C). When a PWM signal goes to “H”, the first output circuit is driven thereby making IF flow from the cathode. When the PWM signal goes to “L”, the first output circuit stops driving, and the second output circuit makes an offset current flow from the cathode.

The present invention discloses a tail-less LED control circuit, which includes: a power supply stage having an output terminal which provides electrical power to an LED circuit; an output capacitor coupled to the output terminal; an LED driver circuit coupled to the power supply stage for controlling the power supply stage to provide the electrical power to the LED circuit, the LED driver circuit receiving a PWM dimming signal for adjusting brightness of the LED circuit; and a MOSFET switch coupled to the output capacitor in series, the MOSFET switch switching synchronously with the PWM dimming signal to alleviate LED afterglow, wherein the MOSFET switch includes a body diode having an anode-cathode direction against the discharge direction of the output capacitor.

The invention discloses a large capacitance rapid discharge device of a light-emitting diode (LED) drive power supply output end and belongs to the technical field of LED drive power supply. The device mainly comprises an input/output rectifier filter circuit, a high-frequency transformer, a pulse-width modulation (PWM) switch, a direct current (DC) circuit and a rapid discharge circuit, the rapid discharge circuit comprises a power supply switch detection circuit, a control circuit and a discharge circuit, one end of the power supply switch detection circuit is connected between the high-frequency transformer and the output rectifier filter circuit, the other end of the power supply switch detection circuit is connected with the control circuit, the power supply switch detection circuit acquires and provides a switching signal, and the control circuit performs logic control according to the switching signal provided by the power supply switch detection circuit to determine whether the discharge circuit is connected or not. According to the light-emitting diode (LED) drive power supply device, energy on large capacitance can be rapidly released, problems of afterglow and efficiency loss caused by slow discharge are solved, when the LED drive power supply is in normal operation, a load resistor is in a non-operating state, and thereby the influence on the work efficiency of the LED drive power supply is absent.

The invention relates to an LED display drive control method used for driving and controlling a plurality of LED lamps electrically connected with M scan lines, wherein the M is a positive integer bigger than 1; the LED display drive control method comprises the following steps: carrying out N-round scanning in sequence, and M scans are done in each round of scanning, wherein the N is a positive integer bigger than 1. In addition, the scan lines corresponding to the first scan of M scans in each round scanning of the N-round scanning are different from each other. The invention also provides an LED lamp panel using the method, and an LED display drive control device realizing the method. The position of the first scan of at least partial rounds of scanning in the multi-round scanning in the prior art can be changed, i.e., a random scanning order is employed in each round of scanning, so each scan line could be the first scan, thus solving the dark problems of the low grey scale first scan of the LED display, and the random scanning order can mitigate afterglow and caterpillar problems.

An oxide phosphor includes an oxide consisting of at least Gd, Ce, Al, Ga, and O, and has the crystal structure of a garnet structure, the atomic ratio (Gd+Ce)/(Al+Ga+Gd+Ce) of which is more than 0.375 and 0.44 or less, and the atomic ratio Ce/(Ce+Gd) of which is 0.0005 or more and 0.02 or less. This oxide phosphor reduces composition misalignment occurring during sintering, being a drawback of a phosphor having (Gd_1-xCe_x)₃Al_5-yGa_yO₁₂ composition, and has a property of extremely small afterglow and high luminescence efficiency. By using this oxide phosphor as a scintillator of a radiation detector having a light detector, the radiation detector with low afterglow and high output can be obtained. Further, by applying this radiation detector to an X-ray CT apparatus, a tomogram with high resolution and high quality can be obtained.

The present invention provides an europium-doped scandium oxide scintillator, which has a general formula (Sc1-x-yMxEuy)2O3, wherein M is one or a variety of materials selected from Lu, Y or Gd, x ismore than or equal to 0 and is less than or equal to 0.4, and y is more than 0 and is less than or equal to 0.2. The present invention provides the europium-doped rare earth sesquioxide scintillationmaterial with characteristics of low afterglow and high scintillation efficiency so as to substantially promote the wide application of the materials in the high-resolution dynamic X imaging field.

A digital addressable lighting interface (DALI) dimming control circuit is used for electrically connecting an LED driving circuit. The LED driving circuit comprises a series LED source, a switch andan LED lamp, wherein the LED source comprises a current feedback circuit and a voltage feedback circuit, the DALI dimming control circuit comprises a microcontroller, a current detection circuit, a voltage detection circuit and a DALI communication circuit, the microcontroller is electrically connected with the current detection circuit, the voltage detection circuit and the DALI communication circuit, the current detection circuit and the voltage detection circuit are used for electrically connecting an output end of the LED source, the DALI communication circuit is used for electrically connecting DALI external equipment, the microcontroller is used for electrically connecting the current feedback circuit, the voltage feedback circuit and the switch, and the microcontroller is used for judging whether LED failure occurs or not according to an output current of the LED source and controlling the LED source to reduce a voltage output if a DALI shutdown signal is received.

The invention relates to a method for accelerating the luminescence decay of a Eu3+ ion doped Lu2O3 film, belonging to the technical field of luminescent film materials. The method adopts a Pechini sol-gel method, and comprises the following steps: adding LuCl3.6H2O powder into absolute ethanol; adding polyethylene glycol, citric acid and little water into the solution, and stirring the solution to prepare transparent sol; adding Eu(NO3)3 solution and co-doped Pr(NO3)3 solution into the sol, and stirring the sol to prepare precursor sol; uniformly coating the precursor sol on a monocrystal silicon substrate by a spin coater, and performing heat treatment on the monocrystal silicon substrate by a hot plate; and calcining the spun silicon substrate after repeated spinning and heat treatment to prepare the co-doped Lu2O3 film. The invention accelerates the luminescence decay of the film, and reduces the persistence of the film by a method of co-doping Pr3+ in Lu2O3: 5mol percent Eu film. Through component ratio optimization, the acquisition of 0.1 mol percent co-doped Pr3+ in the Lu2O3:5mol percent Eu film is a better choice, so that excellent foundation can be laid for application of system scintillation films.

The invention provides a long afterglow material. The chemical formula of the long afterglow material is as follows: SrAl2O4:Eu<2+>, Dy<3+>. A preparation method of the long afterglow material, namely, a method for synthesizing SrAl2O4:Eu<2+>, Dy<3+> with a high temperature solid state method comprises the following steps: weighing a certain quantity of raw materials including Al2O3, SrCO3, Eu2O3,Dy2O3, and H3BO3 in a ratio of substance amounts, grinding and mixing the raw materials uniformly, then putting the mixed raw materials in a tube furnace, calcining the mixed raw materials at 1350 DEG C in a weak reducing atmosphere for 4 h, and performing grinding and pulverizing to obtain the long afterglow material SrAl2O4:Eu<2+>, Dy<3+> with good luminescent property. Release of electrons ina trap in the long afterglow material comprises two types: instantaneous release and delayed release, instantaneous release of the electrons and further transition luminescence are composition of fluorescence, and delayed release leads to afterglow luminescence.

The present invention relates to mixed oxide materials, methods for their preparation, detectors for ionizing radiation and CT scanners. In particular, a mixed oxide material is proposed having the formula (Y_w Tb_x)₃Al_5-y Ga_yO₁₂:Ce_z, wherein 0.01≦w≦0.99, 0.01≦x≦0.99, 0≦y≦3.5 and 0.001≦z≦0.10 and wherein w+x+3*z=1, whereby the mixed oxide material is doped with at least 10 ppm V.

The invention relates to an intrinsic luminous halide scintillation crystal as well as a preparation method and application thereof. The intrinsic luminous halide scintillation crystal has the composition general formula of AB2X3, A2BX3 and A3B2X5, wherein A is at least one of Li, Na, K, Rb, Cs, In and Tl; B is at least one of Cu, Ag and Au; X is at least one of F, Cl, Br and I.