Ronald L Bell

US Patent:

7797295, Sep 14, 2010

Filed:

Jan 4, 2007

Appl. No.:

11/650194

Inventors:

Ronald S. Bell - Menlo Park CA, US
Oliver M. Raskin - Portland OR, US
Duke T. Fan - San Jose CA, US
Chris T. Kalaboukis - Los Gatos CA, US
Ronald G. Martinez - San Francisco CA, US

Assignee:

Yahoo! Inc. - Sunnyvale CA

International Classification:

G06F 17/30

US Classification:

707705, 707706, 707708, 707709, 707711, 707726

Abstract:

Allowing unhosted user content feeds to a public search engine, such as a web search engine, involves a user easily identifying a file as a file the user wants to share with others by, for example, storing the file in a particular directory folder on the user's device. Once identified, the file is scanned and a corresponding entry is inserted into a search index. The storage location on the user's device may be captured, and that information added to the search index for linking to the stored file. The file may be uploaded to a caching server, for serving either primarily from the caching server or secondarily from the caching server when the file is not available from the user's storage. An access policy, which indicates what portion of the public has permission to access the file, may be associated with the shared file.

US Patent:

42800749, Jul 21, 1981

Filed:

Feb 16, 1979

Appl. No.:

6/012687

Inventors:

Ronald L. Bell - Woodside CA

Assignee:

Varian Associates, Inc. - Palo Alto CA

International Classification:

H02N 300

US Classification:

310306

Abstract:

An improved collector is provided for a thermionic energy converter. The collector comprises a p-type layer of a semiconductor material formed on an n-type layer of a semiconductor material. The p-n junction is maintained in a forward biased condition. The electron affinity of the exposed surface of the p-type layer is effectively lowered to a low level near zero by the presence of a work function lowering activator. The dissipation of energy during collection is reduced by the passage of electrons through the p-type layer in the metastable conduction band state. A significant portion of the electron current remains at the potential of the Fermi level of the n-type layer rather than dropping to the Fermi level of the p-type layer. Less energy is therefore dissipated as heat and a higher net power output is delivered from a thermionic energy converter incorporating the collector.

US Patent:

43384803, Jul 6, 1982

Filed:

Dec 29, 1980

Appl. No.:

6/221100

Inventors:

George A. Antypas - Los Altos CA
Ronald L. Bell - Woodside CA
Ronald L. Moon - Atherton CA

Assignee:

Varian Associates, Inc. - Palo Alto CA

International Classification:

H01L 3104

US Classification:

136249

Abstract:

Solar cells with different bandgaps are stacked to form a multijunction photovoltaic converter with a high conversion efficiency. By stacking the cells mechanically rather than by growing them all at one time, the most convenient combination of materials may be selected for the cells. The stacking is completed by means of a glass sealing layer with moats containing inter-cell contacts which are bonded to the cells.

US Patent:

41151496, Sep 19, 1978

Filed:

Jun 20, 1977

Appl. No.:

5/807937

Inventors:

Ronald L. Bell - Woodside CA

Assignee:

Varian Associates, Inc. - Palo Alto CA

International Classification:

H01L 3104

US Classification:

136 89PC

Abstract:

A lens or mirror is employed to concentrate sunlight onto a photovoltaic cell. The cell employs a broad conductor around the periphery of its active surface, and narrow higher resistance conductor strips over the inner part of the surface. The cell and mirror are sized, positioned and shaped such that the image of the sun on the cell's surface is non-uniform, with a proportionately higher concentration of light falling near the periphery of the cell adjacent the peripheral conductors. Thus, the generated current is greater at the periphery, so that less energy is lost due to series resistance of the surface conductors, for more efficiency compared to a uniformly illuminated cell. The non-uniformity can conveniently be obtained by utilizing the natural spherical aberrations of a simple spherical mirror or lens. Also the cell can be positioned relatively close to the mirror outside the focal plane, so that the illuminated area on the cell is larger than the focused image of the sun in the focal plane. Thus, for given diameters of cell and mirror, the arrangement is more compact, and much less sensitive to inaccuracies in mirror curvature.

US Patent:

43799442, Apr 12, 1983

Filed:

Feb 5, 1981

Appl. No.:

6/232062

Inventors:

Peter G. Borden - Menlo Park CA
Ronald L. Bell - Woodside CA
Syed B. Hyder - Los Altos Hills CA

Assignee:

Varian Associates, Inc. - Palo Alto CA

International Classification:

H01L 3106

US Classification:

136259

Abstract:

A grooved solar cell for deployment at a set angle with respect to incoming radiation has reduced contact obscuration and series resistance. A regular array of walls formed by grooves in a crystalline semiconductor substrate is exposed to incoming radiation. Metallic contacts are formed on those walls of the grooves which are not to be exposed to sunlight. The solar cell is mounted in an apparatus at a set angle with respect to incoming radiation. The array of walls is exposed to incoming radiation while the walls with metal contacts are substantially shadowed. In a preferred embodiment the grooves are formed by using orientation specific etches.

US Patent:

44008686, Aug 30, 1983

Filed:

Feb 24, 1982

Appl. No.:

6/351707

Inventors:

George A. Antypas - Los Altos CA
Ronald L. Bell - Woodside CA
Ronald L. Moon - Atherton CA

Assignee:

Varian Associates, Inc. - Palo Alto CA

International Classification:

H01L 21283
H01L 3104

US Classification:

29572

Abstract:

Solar cells with different bandgaps are stacked to form a multijunction photovoltaic converter with a high conversion efficiency. By stacking the cells mechanically rather than by growing them all at one time, the most convenient combination of materials may be selected for the cells. The stacking is completed by means of a glass sealing layer with moats containing inter-cell contacts which are bonded to the cells.

US Patent:

40020312, Jan 11, 1977

Filed:

Jul 7, 1975

Appl. No.:

5/593913

Inventors:

Ronald L. Bell - Woodside CA

Assignee:

Varian Associates, Inc. - Palo Alto CA

International Classification:

F03G 702
H01L 3106

US Classification:

60641

Abstract:

A solar energy converter uses gallium arsenide photovoltaic cells to convert light to direct current. Optical concentrators reduce the needed area of cells. Gallium arsenide retains high conversion efficiency up to several hundred degrees, so the waste heat may be used to produce mechanical power in a Rankine cycle engine.

US Patent:

39581438, May 18, 1976

Filed:

Mar 8, 1974

Appl. No.:

5/449292

Inventors:

Ronald L. Bell - Woodside CA

Assignee:

Varian Associates - Palo Alto CA

International Classification:

H01J 3906
H01J 3126

US Classification:

313 94

Abstract:

A long wavelength photoemitter, for example a III-V semiconductor, having a work function reduction activation layer thereon, with means for overcoming the energy barrier between the semiconductor conduction band edge and the vacuum comprising means for thermally energizing the photoexcited electrons in the conduction band from a lower energy level therein to a higher "metastable" energy level in which they may reside for a sufficient time such that the electrons can pass with high probability from the elevated energy level into the vacuum over the energy barrier. In one embodiment, promotion of electrons to this higher energy level in the conduction band results from proper selection of the semiconductor alloy with conduction band levels favoring such room temperature thermal excitation. In another embodiment, a Schottky barrier is formed between the semiconductor emitter surface and the activation layer, by means of which an internal electric field is applied to the cathode resulting in high effective electron temperature for energy level transfer analogous to the intervalley electron transfer process of the Gunn effect. In yet other embodiments, composite semiconductor bodies are fabricated in which one region may advantageously be designed for efficient absorption of long-wavelength photons, and another for efficient operation of the promotion mechanism, which together assure a high quantum efficiency.