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: 20080210874
    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: October 9, 2007
    Publication date: September 4, 2008
    Applicant: Intematix Corporation
    Inventors: Shifan Cheng, Yi-Qun Li
  • Publication number: 20080197290
    Abstract: Disclosed herein are camera-based x-ray digital image detectors that contain an assembly of a scintillator screen, a wide-angle optical lens or fisheye lens, and a digital image sensor. Images formed by x-ray radiation on the scintillator screen are projected onto a much smaller area image sensor through a fisheye or super-wide-angle optical lens, hence forming a highly distorted image thereon. Transparent lead-contained glasses or plastics are utilized to shield image sensor from x-ray damage. Imaging distortion and light falloff caused by the lens optics are corrected by software algorithms. Sub-millimeter resolution may be achieved with reduced design complexity and substantially lower manufacturing costs.
    Type: Application
    Filed: December 6, 2007
    Publication date: August 21, 2008
    Applicant: Intematix Corporation
    Inventors: Xianglong Yuan, Shifan Cheng, Yi-Qun Li
  • Patent number: 7399428
    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, Tl, 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: Grant
    Filed: February 18, 2005
    Date of Patent: July 15, 2008
    Assignee: Intematix Corporation
    Inventors: Yi-Qun Li, Shifan Cheng, Ning Wang, Yi Dong, Xiao-Dong Sun
  • Patent number: 7390437
    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[2+(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?z?1.2. In another embodiment, 0.2<x<0.5. The composition may contain a halogen, such as fluorine or chlorine.
    Type: Grant
    Filed: July 1, 2005
    Date of Patent: June 24, 2008
    Assignee: Intematix Corporation
    Inventors: Yi Dong, Ning Wang, Shifan Cheng, Yi-Qun Li
  • Publication number: 20080138268
    Abstract: Disclosed herein are cerium doped, garnet phosphors emitting in the yellow region of the spectrum, and having the general formula (Y,A)3(Al,B)5(O,C)12:Ce3+, where A is Tb, Gd, Sm, La, Sr, Ba, Ca, and/or Mg, and substitutes for Y, B is Si, Ge, B, P, and/or Ga, and substitutes for Al, and C is F, Cl, N, and/or S, where C substitutes for O. Relative to a solid-state-reaction method, the instant co-precipitation methods provide a more homogeneous mixing environment to enhance the distribution of the Ce3+ activator in the YAG matrix. Such a uniform distribution has the benefit of an increased emission intensity. The primary particle size of the as-prepared phosphor is about 200 nm, with a narrow distribution.
    Type: Application
    Filed: October 18, 2007
    Publication date: June 12, 2008
    Applicant: Intematix Corporation
    Inventors: Dejie Tao, Yi-Qun Li, Shifan Cheng
  • Publication number: 20080116786
    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, N, and B. 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: December 24, 2007
    Publication date: May 22, 2008
    Applicant: Intematix Corporation
    Inventors: Ning Wang, Yi Dong, Shifan Cheng, Yi-Qun Li
  • Publication number: 20080111472
    Abstract: Novel aluminum-silicate based orange-red phosphors, with mixed di- and trivalent cations are disclosed. The phosphors have the formula (Sr1?x?yMxTy)3?mEum(Si1?zAlz)O5, where M is at least one of Ba, Mg, Ca, and Zn in an amount ranging from 0?x?0.4. T is a trivalent metal in an amount ranging from 0?y?0. This phosphor is configured to emit visible light having a peak emission wavelength greater than about 580 nm. The phosphors may contain a halogen anion such as F, Cl, and Br, at least some of which is substitutionally positioned on oxygen lattice sites. The present aluminum-silicate phosphors have applications in white and orange-red illumination systems, as well as plasma display panels.
    Type: Application
    Filed: April 9, 2007
    Publication date: May 15, 2008
    Applicant: Intematix Corporation
    Inventors: Shengfeng Liu, Shifan Cheng, Yi-Qun Li
  • Publication number: 20080073616
    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: September 10, 2007
    Publication date: March 27, 2008
    Applicant: Intematix Corporation
    Inventors: Yi Dong, Ning Wang, Shifan Cheng, Yi-Qun Li
  • Publication number: 20080043129
    Abstract: A semiconductor color image sensor comprises: an array of semiconductor photo-sensors (CMOS or CCD) and a color filter array comprising an array of red, green and blue filter elements in which each filter element is associated with a respective one of the photo-sensors. The sensor further comprises a phosphor (photo-luminescent) material associated with each of the blue filter elements and configured to absorb blue light and re-emit light of a longer wavelength range which is then incident on the photo-sensor associated with the blue filter element. Preferably the phosphor material is selected such that light of the longer wavelength range substantially matches the spectral response of the photo-sensor. The image sensor can further comprise an array of micro-lenses for focusing light onto the photo-sensors of the image sensor, wherein each micro-lens is associated with a respective one of the photo-sensors.
    Type: Application
    Filed: August 13, 2007
    Publication date: February 21, 2008
    Applicant: Intematix Corporation
    Inventors: Yi-Qun Li, Shifan Cheng, Magnus Ryde, Mike Ko
  • Publication number: 20080018235
    Abstract: Novel aluminate-based green phosphors are disclosed having the formula M1-xEuxMg1-yMnyAlzO[(x+y)+3z/2]; where 0.1<x<1.0;0.1<y<1.0; 0.2<x+y<2.0; and 2?z?14; wherein M is selected from the group consisting of Ba, Sr, Ca, and Zn; and wherein the phosphor is configured to absorb UV and visible radiation having a wavelength ranging from about 220 to 440 nm, and emit visible green light having a wavelength ranging from about 500 to 550 nm. A novel feature of the present aluminate-based green phosphors is the relatively narrow range of wavelength over which they can be configured to emit; in one embodiment, this range is from about 518 nm to 520 nm. In an alternative embodiment, the phosphor emits visible light with a peak wavelength having a full width at half maximum of less than or equal to about 40 nm in some embodiments, and 80 nm in other embodiments.
    Type: Application
    Filed: May 15, 2007
    Publication date: January 24, 2008
    Applicant: Intematix Corporation
    Inventors: Ning Wang, Yi Dong, Shifan Cheng, Yi-Qun Li, Ravilisetty Rao
  • Publication number: 20070295383
    Abstract: The present embodiments are directed to photovoltaic devices that convert sunlight into electrical energy. More specifically, the present embodiments include a phosphor-containing, wavelength-converting material for shifting higher energy light to a lower energy form, the latter being more suitable for the typical solar cell to convert to electricity. The absorption of the phosphor may range from about 280 to 460 nm. Advantageously, the phosphor component of the wavelength converter may be in the form of nano-particles embedded in a transparent matrix for reducing scattering losses.
    Type: Application
    Filed: March 30, 2007
    Publication date: December 27, 2007
    Applicant: Intematix Corporation
    Inventors: Yi-Qun Li, Wei Shan, Shifan Cheng, Mike Ko
  • Patent number: 7311858
    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)2 SiO4: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: Grant
    Filed: September 22, 2004
    Date of Patent: December 25, 2007
    Assignee: Intematix Corporation
    Inventors: Ning Wang, Yi Dong, Shifan Cheng, Yi-Qun Li
  • Publication number: 20070241311
    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: October 18, 2007
    Inventors: Shifan Cheng, Yi-Qun Li
  • Patent number: 7279120
    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: Grant
    Filed: August 27, 2004
    Date of Patent: October 9, 2007
    Assignee: Intematix Corporation
    Inventors: Shifan Cheng, Yi-Qun Li
  • Patent number: 7267787
    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: Grant
    Filed: August 4, 2004
    Date of Patent: September 11, 2007
    Assignee: Intematix Corporation
    Inventors: Yi Dong, Ning Wang, Shifan Cheng, Yi-Qun Li
  • Publication number: 20070065947
    Abstract: This invention provides methods and systems to prepare replicate arrays from master arrays of liquid solutions. Replicate arrays of liquid solutions can be reacted to form product solid inorganic material arrays for analysis and selection of optimum processes and products with desirable properties.
    Type: Application
    Filed: September 19, 2005
    Publication date: March 22, 2007
    Applicant: Intematix Corporation
    Inventors: Yi Dong, Shifan Cheng, Dejie Tao, Yi-Qun Li
  • Publication number: 20070029526
    Abstract: Novel orange phosphors are disclosed having the comprise silicate-based compounds having the formula (Sr,A1)x,(Si,A2)(O,A3)2+x:Eu2+, where A1 is at least one divalent cation (a 2+ ion) including Mg, Ca, Ba, or Zn, or a combination of 1+ and 3+ cations; A2 is a 3+, 4+, or 5+ cation, including at least one of B, Al, Ga, C, Ge, P; A3 is a 1?, 2?, or 3? anion, including F, Cl, and Br; and x is any value between 2.5 and 3.5, inclusive. The formula is written to indicate that the A1 cation replaces Sr; the A2 cation replaces Si, and the A3 anion replaces O. These orange phosphors are configured to emit visible light having a peak emission wavelength greater than about 565 nm. They have applications in white LED illumination systems, plasma display panels, and in orange and other colored LED systems.
    Type: Application
    Filed: October 25, 2005
    Publication date: February 8, 2007
    Applicant: Intematix Corporation
    Inventors: Shifan Cheng, Dejie Tao, Yi Dong, Yi-Qun Li
  • Publication number: 20060261309
    Abstract: Novel two-phase yellow phosphors are disclosed having a peak emission intensity at wavelengths ranging from about 555 nm to about 580 nm when excited by a radiation source having a wavelength ranging from 220 nm to 530 nm. The present phosphors may be represented by the formula a[Srx(M1)1-x]zSiO4?(1-a)[Sry(M2)1-y]uSiO5:Eu2+D, wherein M1 and M2 are at least one of a divalent metal such as Ba, Mg, Ca, and Zn, the values of a, x, y, z and u follow the following relationships: 0.6?a?0.85; 0.3?x?0.6; 0.85?y?1; 1.5?z?2.5; 2.6?u?3.3; and Eu and D each range from 0.001 to about 0.5. D is an anion selected from the group consisting of F, Cl, Br, S, and N, and at least some of the D anion replaces oxygen in the host silicate lattice of the phosphor. The present yellow phosphors have applications in high brightness white LED illumination systems, LCD display panels, plasma display panels, and yellow LEDs and illumination systems.
    Type: Application
    Filed: May 3, 2006
    Publication date: November 23, 2006
    Applicant: Intematix Corporation
    Inventors: Yi-Qun Li, Yi Dong, Shifan Cheng, Dejie Tao, Ning Wang
  • Publication number: 20060158090
    Abstract: Novel aluminate-based green phosphors are disclosed having the formula M1?xEuxAlyO1+3y/2, where M is at least one of a divalent metal selected from the group consisting of Ba, Sr, Ca, Mg, Mn, Zu, Cu, Cd, Sm, and Tm; 0.1<x<0.9; and 0.5:?y?12. phosphors are configured to absorb substantially non-visible radiation having a wavelength ranging from about 280 to 420 nm, and emit visible green light having a wavelength ranging from about 500 to 550 nm. In a particular embodiment, the phosphor contains the divalent alkaline earth metals Mg, and Mn may be present as well. A novel feature of the present aluminate-based green phosphors is the relatively narrow range of wavelength over which they can be configured to emit; in one embodiment, this range is from about 518 nm to 520 nm. In an alternative embodiment, the phosphor emits visible light with a peak wavelength having a full width at half maximum of less than or equal to about 40 nm.
    Type: Application
    Filed: January 14, 2005
    Publication date: July 20, 2006
    Applicant: Intematix Corporation
    Inventors: Ning Wang, Yi Dong, Shifan Cheng, Yi-Qun Li
  • Publication number: 20060145123
    Abstract: Novel green phosphors are disclosed having the comprise silicate-based compounds having the formula (Sr,A1)x(Si,A2)(O,A3)2+x:Eu2+, where A1 is at least one divalent cation (a 2+ ion) including Mg, Ca, Ba, or Zn, or a combination of 1+ and 3+ cations; A2 is a 3+, 4+, or 5+ cation, including at least one of B, Al, Ga, C, Ge, N, and P; A3 is a 1?, 2?, or 3? anion, including F, Cl, Br, and S; and x is any value between 1.5 and 2.5, both inclusive. The formula is written to indicate that the A1 cation replaces Sr; the A2 cation replaces Si, and the A3 anion replaces O. These green phosphors are configured to emit visible light having a peak emission wavelength greater than about 480 nm. They have applications in green illumination systems, red-green-blue backlighting systems, white LEDs, and plasma display panels (PDPs).
    Type: Application
    Filed: November 8, 2005
    Publication date: July 6, 2006
    Applicant: Intematix Corporation
    Inventors: Yi-Qun Li, Yi Dong, Dejie Tao, Shifan Cheng, Ning Wang