Patents by Inventor Shifan Cheng

Shifan Cheng has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20060043335
    Abstract: This invention provides novel cadmium tungstate scintillator materials that show improved radiation hardness. In particular, it was discovered that doping of cadmium tungstate (CdWO4) with trivalent metal ions or monovalent metal ions is particularly effective in improving radiation hardness of the scintillator material.
    Type: Application
    Filed: August 27, 2004
    Publication date: March 2, 2006
    Inventors: Shifan Cheng, Yi-Qun Li
  • Publication number: 20060027785
    Abstract: Novel phosphor systems are disclosed having the formula A2SiO4:Eu2+D, where A is at least one of a divalent metal selected from the group consisting of Sr, Ca, Ba, Mg, Zn, and Cd; and D is a dopant selected from the group consisting of F, Cl, Br, I, S and N. In one embodiment, the novel phosphor has the formula (Sr1-x-yBaxMy)2SiO4: Eu2+F (where M is one of Ca, Mg, Zn, or Cd in an amount ranging from 0<y<0.5). The phosphor is configured to absorb visible light from a blue LED, and luminescent light from the phosphor plus light from the blue LED may be combined to form white light. The novel phosphors can emit light at intensities greater than either conventionally known YAG compounds, or silicate-based phosphors that do not contain the inventive dopant ion.
    Type: Application
    Filed: April 5, 2005
    Publication date: February 9, 2006
    Applicant: Intematix Corporation
    Inventors: Ning Wang, Yi Dong, Shifan Cheng, Yi-Qun Li
  • Publication number: 20060027786
    Abstract: Embodiments of the present invention are directed in general to novel aluminate-blue phosphors. Specifically, embodiments of the present invention are directed to use of the novel aluminate-based blue phosphors in white light illumination systems, and in display applications such as back lighting in liquid crystal displays (LCD's) and plasma display panels (PDPs). Embodiments of the present invention are further directed toward aluminate-based phosphors having the general formula (M1?xEux)2?zMgzAlyO[1+(3/2)y], where M is a divalent alkaline earth metal other than magnesium (Mg) from group IIA of the periodic table, where 0.05<x<0.5; 3?y?12; and 0.8?y?1.2. In another embodiment, 0.2<x<0.5. The composition may contain a halogen, such as fluorine or chlorine.
    Type: Application
    Filed: July 1, 2005
    Publication date: February 9, 2006
    Applicant: Intematix Corporation
    Inventors: Yi Dong, Ning Wang, Shifan Cheng, Yi-Qun Li
  • Publication number: 20060028122
    Abstract: Novel phosphor systems are disclosed having the formula A2SiO4:Eu2+D, where A is at least one of a divalent metal selected from the group consisting of Sr, Ca, Ba, Mg, Zn, and Cd; and D is a dopant selected from the group consisting of F, Cl, Br, I, P, S and N. In one embodiment, the novel phosphor has the formula (Sr1-x-yBaxMy)2SiO4:Eu2+F (where M is one of Ca, Mg, Zn, or Cd in an amount ranging from 0<y<0.5). The phosphor is configured to absorb visible light from a blue LED, and luminescent light from the phosphor plus light from the blue LED may be combined to form white light. The novel phosphors can emit light at intensities greater than either conventionally known YAG compounds, or silicate-based phosphors that do not contain the inventive dopant ion.
    Type: Application
    Filed: September 22, 2004
    Publication date: February 9, 2006
    Applicant: Intematix Corporation
    Inventors: Ning Wang, Yi Dong, Shifan Cheng, Yi-Qun Li
  • Publication number: 20060027781
    Abstract: Novel phosphor systems for a white LED are disclosed. The phosphor systems are excited by a non-visible to near-UV radiation source having an excitation wavelength ranging from about 250 to 420 nm. The phosphor system may comprise one phosphor, two phosphors, and may include optionally a third and even a fourth phosphor. In one embodiment of the present invention, the phosphor is a two phosphor system having a blue phosphor and a yellow phosphor, wherein the long wavelength end of the blue phosphor is substantially the same wavelength as the short wavelength end of the yellow phosphor. Alternatively, there may be a wavelength gap between the yellow and blue phosphors. The yellow phosphor may be phosphate or silicate-based, and the blue phosphor may be silicate or aluminate-based. Single phosphor systems excited by non-visible radiation are also disclosed.
    Type: Application
    Filed: August 4, 2004
    Publication date: February 9, 2006
    Applicant: Intematix Corporation
    Inventors: Yi Dong, Ning Wang, Shifan Cheng, Yi-Qun Li
  • Publication number: 20060022170
    Abstract: Embodiments of the present invention are directed to compositions and processing methods of rare-earth vanadate based materials that have high emission efficiency in a wavelength range of 480 to 700 nm with the maximum intensity at 535 nm (bright yellow) under UV, X-ray and other forms of high-energy irradiation. Embodiments of the present invention are directed to general chemical compositions of the form (Gd1-xAx)(V1-yBy)(O4-zCz), where A is selected from the group consisting of Bi, Ti, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu for 0<x<0.2; B is Ta, Nb, W, and Mo for 0<y<0.1; and C is N, F, Br, and I for 0<z<0.1. Methods of preparation include sol gel, liquid flux, and co-precipitation processes.
    Type: Application
    Filed: February 18, 2005
    Publication date: February 2, 2006
    Applicant: Intematix Corporation
    Inventors: Yi-Qun Li, Shifan Cheng, Ning Wang, Yi Dong, Xiao-Dong Sun
  • Patent number: 6641940
    Abstract: Composition for a solid state material, in bulk and in thin film form, that provides relatively high dielectric permittivity that is tunable with variable electrical field bias, relatively low loss tangent and low leakage current for microwave applications. In a first embodiment, the material is BaySr1−yTi1−xMxO3, where M is a substance or mixture including one or more elements drawn from a group consisting of Ta, Zr, Hf, V, Nb, Al, Ga, Cr, Mo, W, Mn, Sc and Re, and the indices x and y satisfy 0≦x≦1 and 0≦y≦1. A preferred choice is M=Ta, V, W, Mo and/or Nb. In a second embodiment, the material is BaySr1−yTi1−x−zTaxMzO3, where M is a substance or mixture including one or more trivalent elements drawn from a group consisting of Al, Ga and Cr and the indices x, y and z satisfy 0≦x+z≦1 and 0≦y≦1.
    Type: Grant
    Filed: October 9, 2001
    Date of Patent: November 4, 2003
    Assignee: Intematix Corporation
    Inventors: Yi-Qun Li, Xiao-Dong Xiang, Yi Dong, Shifan Cheng, Gang Wang, Ning Wang