Shifan S Cheng

US Patent:

7279120, Oct 9, 2007

Filed:

Aug 27, 2004

Appl. No.:

10/928755

Inventors:

Shifan Cheng - Moraga CA, US
Yi-Qun Li - Walnut Creek CA, US

Assignee:

Intematix Corporation - Fremont CA

International Classification:

C09K 11/68

US Classification:

2523015, 378 4, 378 988, 378 9812, 250362, 250367, 2504752, 2504831, 25037009

Abstract:

This invention provides novel cadmium tungstate scintillator materials that show improved radiation hardness. In particular, it was discovered that doping of cadmium tungstate (CdWO) with trivalent metal ions or monovalent metal ions is particularly effective in improving radiation hardness of the scintillator material.

US Patent:

7311858, Dec 25, 2007

Filed:

Sep 22, 2004

Appl. No.:

10/948764

Inventors:

Ning Wang - Martinez CA, US
Yi Dong - Tracy CA, US
Shifan Cheng - Moraga CA, US
Yi-Qun Li - Walnut Creek CA, US

Assignee:

Intematix Corporation - Fremont CA

International Classification:

C09K 11/59
H01L 51/00

US Classification:

2523014F, 2523016 F, 2523014 R, 2523014 H, 2523014 S, 257 98, 313503

Abstract:

Novel phosphor systems are disclosed having the formula ASiO:EuD, 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 (SrBaM)SiO:EuF (where M is one of Ca, Mg, Zn, or Cd in an amount ranging from 0

US Patent:

7399428, Jul 15, 2008

Filed:

Feb 18, 2005

Appl. No.:

11/061979

Inventors:

Yi-Qun Li - Walnut Creek CA, US
Shifan Cheng - Moraga CA, US
Ning Wang - Martinez CA, US
Yi Dong - Tracy CA, US
Xiao-Dong Sun - Fremont CA, US

Assignee:

Intematix Corporation - Fremont CA

International Classification:

C09K 11/82

US Classification:

2523014R, 117948, 117 13, 117 19

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 (GdA)(VB)(OC), 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

US Patent:

7541728, Jun 2, 2009

Filed:

Jan 14, 2005

Appl. No.:

11/036914

Inventors:

Ning Wang - Martinez CA, US
Yi Dong - Tracy CA, US
Shifan Cheng - Moraga CA, US
Yi-Qun Li - Walnut Creek CA, US

Assignee:

Intematix Corporation - Fremont CA

International Classification:

H01J 1/62
C09K 11/77

US Classification:

313485, 2523014 R

Abstract:

Novel aluminate-based green phosphors are disclosed having the formula MEuAlO, 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

US Patent:

7557356, Jul 7, 2009

Filed:

Dec 6, 2007

Appl. No.:

11/999729

Inventors:

Xianglong Yuan - Fremont CA, US
Shifan Cheng - Dublin CA, US
Yi-Qun Li - Danville CA, US

Assignee:

Intematix Corporation - Fremont CA

International Classification:

G01T 1/20

US Classification:

25037011

Abstract:

A camera-based x-ray digital image detectors can 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 can be 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 can be utilized to shield image sensor from x-ray damage. Imaging distortion and light falloff caused by the lens optics can be corrected by software algorithms. Sub-millimeter resolution may be achieved with reduced design complexity and substantially lower manufacturing costs.

US Patent:

7575697, Aug 18, 2009

Filed:

Nov 8, 2005

Appl. No.:

11/269953

Inventors:

Yi-Qun Li - Danville CA, US
Yi Dong - Tracy CA, US
Dejie Tao - Fremont CA, US
Shifan Cheng - Moraga CA, US
Ning Wang - San Jose CA, US

Assignee:

Intematix Corporation - Fremont CA

International Classification:

C09K 11/59
C09K 11/55
H01L 51/54
H01J 17/49

US Classification:

2523014F, 2523016 F, 2523014 H, 2523014 P, 2523016 P, 257 98, 313503, 313582, 313584, 313486

Abstract:

Novel green phosphors are disclosed having the comprise silicate-based compounds having the formula (Sr,A)(Si,A)(O,A):Eu, where Ais at least one divalent cation (a 2+ ion) including Mg, Ca, Ba, or Zn, or a combination of 1+ and 3+ cations; Ais a 3+, 4+, or 5+ cation, including at least one of B, Al, Ga, C, Ge, N, and P; Ais 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 Acation replaces Sr; the Acation replaces Si, and the Aanion 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).

US Patent:

7597817, Oct 6, 2009

Filed:

Apr 21, 2004

Appl. No.:

10/829590

Inventors:

Yi-Qun Li - Walnut Creek CA, US
Ning Wang - Martinez CA, US
Qizhen Xue - Walnut Creek CA, US
Shifan Cheng - Moraga CA, US
Xiao-Dong Xiang - Danville CA, US

Assignee:

Intematix Corporation - Fremont CA

International Classification:

H01F 1/03
C01F 11/00
C01F 17/00

US Classification:

252 6251R, 501135, 501138

Abstract:

Novel metal oxide compositions are disclosed. These ferromagnetic or ferrimagnetic compositions have resitivities that vary between those of semiconducting and insulating materials, and they further exhibit Curie temperatures greater than room temperature (i. e. , greater than 300 K). They are perovskite structures with the general chemical formulas (AM)BO, (AM)(B′B″)Oor A(BM)O, where A can be a 1, 2 and 3 charged ion; B can be a 5, 4, 3 charged ion; B′ and B″ can be 2, 3, 4, 5 and 6 charged ion. M is a magnetic ion dopant. X-ray diffraction patterns are presented for exemplary compositions.

US Patent:

7601276, Oct 13, 2009

Filed:

May 3, 2006

Appl. No.:

11/417690

Inventors:

Yi-Qun Li - Danville CA, US
Yi Dong - Tracy CA, US
Shifan Cheng - Dublin CA, US
Dejie Tao - Fremont CA, US
Ning Wang - Martinez CA, US

Assignee:

Intematix Corporation - Fremont CA

International Classification:

C09K 11/55
C09K 11/59

US Classification:

2523014F, 2523016 F, 313503, 257 98

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[Sr(M1)]SiO. (1-a)[Sr(M2)]SiO:EuD, 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.