1-57. (canceled)
58. A method for the formation of small-size metal oxide particles, comprising the steps of:
a) preparing a starting aqueous solution comprising at least one of metallic ion and complexes thereof, at a concentration of at least 0.1% ww of said metal component;
b) preparing a modifying aqueous solution having a temperature greater than 50\xb0 C.;
c) contacting the modifying aqueous solution with the starting aqueous solution in a continuous mode in a mixing chamber to form a modified system;
d) removing the modified system from the mixing chamber in a plug-flow mode; wherein said method is characterized in that:
i) the residence time in the mixing chamber is less than about 5 minutes; and
ii) there are formed particles or aggregates thereof, wherein the majority of the particles formed are between about 2 nm and about 500 nm in size and optionally further calcining said formed particles at a temperature in a range between about 90\xb0 C. and about 900\xb0 C. to form dehydrated particles
59. A method according to claim 58, wherein the conditions in said system are adjusted by at least one of the steps of:
a) heating said starting aqueous solution by at least 10\xb0 C.,
b) elevating the pH of said starting aqueous solution by at least 0.2 units; and
c) diluting the starting aqueous solution by at least 20% or a combination thereof wherein said modified system is maintained at said adjusting conditions for at least 0.5 minutes.
60. A method according to claim 59, wherein said adjustment of conditions is carried out for a period of less than 2 hours.
61. A method according to claim 58, further characterized in that the majority of the formed particles have a degree of crystallinity of more than 50%.
62. A method according to claim 58, further characterized in that the size ratio between the smallest and largest particle of the mean 50% by weigh of the formed particles is less than about 10
63. A method according to claim 58, wherein said dehydrating step and said adjusting step are conducted simultaneously and wherein adjusting involves heating to the temperature of the calcination.
64. A method according to claim 58, wherein said metal is selected from the group consisting of tin, aluminum, silicon, zinc, cobalt, copper, nickel, magnesium, yttrium, vanadium, manganese, cadmium, zirconium, palladium, molybdenum, chromium ruthenium and a combination thereof and , wherein said metal oxide is selected from the group consisting of metal oxides of the formula MetalxOy, metal hydroxy-oxides of the formula Metalp(OH)qOr, metallic acid, various hydration forms of those and compositions wherein those are major components, wherein x, y, p, q, r are each whole integers.
65. A method according to claim 58, wherein the metal concentration in the prepared solution is greater than about 5 wt %
66. A method according to claim 58, wherein said starting solution is treated by at least one of the following operations: a) ultrasound, and b) microwaving.
67. Metal oxide particles whenever formed according to the method of claim 58, products of their conversion and preparations comprising them.
68. The metal oxide particles of claim 67, characterized in at least one of
i. that the purity of the metal oxide particles with regard to other metals intermixed therewith is of at least 95%; and
ii. that said particles are doped with atoms of other compounds.
69. A preparation according to claim 67, wherein said particles are dispersed in a liquid, supported on a solid compound, agglomerated to larger particles, partially fused, coated or any combination thereof.
70. A method comprising using at least one of said particles and said preparations according to claim 67 as at least one of a pigment, a catalyst and a coating.
71. Industrial production of particles according to claim 58, wherein particles are formed at a rate of at least 50 Kghour.
72. A method according to claim 58, wherein the temperature of the modifying solution is in the range between 100\xb0 C. and 300\xb0 C.
73. A method according to claim 58, wherein the modified system is retained for a duration of between 1 and 30 minutes and wherein during said retaining the temperature is maintained within less than a 20\xb0 C. change in either direction from the temperature of the modified system.
74. A method according to claim 58, where the residence time in the mixing chamber is less than about 5 seconds.
75. A method according to claim 58, wherein the removed modified system and optionally also a metal salt solution, is introduced into a crystallizer, the temperature of which is kept in the range of 100-300\xb0 C.
76. A method according to claim 58, wherein a reagent selected from the group consisting of a dispersant and a basic compound is present in at least one step of a group consisting of preparing, maintaining, adjusting, crystallizing in said crystallizer, flowing in said plug-flow mode, wherein said dispersant is selected from a group consisting of cationic polymers, anionic polymers, nonionic polymers, surfactants, and mixtures thereof and wherein said method further comprises the step of changing the amount of said dispersant.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for creating brightness filters:
said brightness filters being adapted in use for an image projection system which projects divided images on a curved screen respectively from a plurality of projectors with adjacent ones of said divided images partially overlapped to reproduce a combined image, said filter being designed to adjust brightness of said divided images for harmonizing the brightness of the overlapping areas with the brightness of non-overlapping areas to make said combined image seamless, said method comprising the steps of:
(a) producing a screen model reflecting a shape of said curved screen;
(b) setting projection points respectively for projecting therefrom said divided images on said screen model, said projection points being different from each other in conformity with said projectors, respectively;
(c) allocating one of said divided images to a reference image and allocating each of the adjacent divided images to a peripheral image;
(d) setting a view point that is coincident with the projection point of said reference image;
(e) obtaining a 2-dimensional reference area of said reference image that is rendered on said screen model and is viewed from said view point;
(f) obtaining a 2-dimensional peripheral area of said peripheral image that is rendered on said screen model and is viewed from said view point;
(g) extracting an overlapping area of said 2-dimensional reference area that overlaps with the 2-dimensional peripheral area;
(h) making a brightness correction for either said overlapping area or said non-overlapping area with regard to said 2-dimensional reference area;
(i) providing a brightness filter for said reference image that realizes said brightness correction;
(j) allocating another divided image to said reference image and repeating the steps of (d) to (i) for providing said brightness filter for each of said divided images.
2. The method as set forth in claim 1, wherein said method employs a frame buffer for storing said 2-dimensional reference area and said 2-dimensional peripheral area, respectively, said 2-dimensional reference area being divided into discrete elements having corresponding addresses in said frame buffer, said 2-dimensional peripheral area being divided into discrete elements having corresponding addresses in said frame buffer, said step (g) comparing said addresses of the 2-dimensional reference area with said addresses of the 2-dimensional peripheral area to define said overlapping area as having the common addresses.
3. A virtual space creation system, said system comprising:
a curved screen offering a wide field of view;
an image creation module, said image creation module dividing a single seamless image into a plurality of divided images which are intended to be projected on said curved screen;
a plurality of projectors, said projectors project said divided images respectively on said curved screen in a partially overlapping relation with each other;
wherein said image creation module has a brightness filter for each of said divided images, said brightness filters being prepared by the steps of;
(a) producing a screen model reflecting a shape of said curved screen;
(b) setting projection points respectively for projecting therefrom said divided images on said screen model, said projection points being different from each other in conformity with said projectors, respectively;
(c) allocating one of said divided images to a reference image and allocating each of the adjacent divided images to a peripheral image;
(d) setting a view point that is coincident with the projection point of said reference image;
(e) obtaining a 2-dimensional reference area of said reference image that is rendered on said screen model and is viewed from said view point;
(f) obtaining a 2-dimensional peripheral area of said peripheral image that is rendered on said screen model and is viewed from said view point;
(g) extracting an overlapping area of said 2-dimensional reference area that overlaps with the 2-dimensional peripheral area;
(h) making a brightness correction for either said overlapping area or said non-overlapping area with regard to said 2-dimensional reference area;
(i) providing a brightness filter for said reference image that realizes said brightness correction;
(j) allocating another divided image to said reference image and repeating the steps of (d) to (i) for providing said brightness filter for each of said divided images.
4. The virtual space creation system as set forth in claim 3, wherein said curved screen is in the form of a concavity having a horizontal axis and a vertical axis, said concavity being curved with respect to said horizontal axis as well as said vertical axis.
5. The virtual space creation system as set forth in claim 3, wherein said image creation module further includes a distortion correction scheme which corrects said divided image in order to minimize a distortion appearing in said divided image that is viewed from a particular view point.
6. The system as set forth in claim 3, wherein said projectors are divided into a first group and a second group, the projectors in said first group projecting said divided images respectively as right-eye images, and the projectors in said second group projecting said divided images respectively as left-eye images, said system further including:
polarizing filters processing said right-eye image and said left-eye image into respective polarized images;
a pair of polarized glasses adapted to be worn by an observer, said a pair of polarized glasses combining said polarized images into a three-dimensional image.
7. The system as set forth in claim 3, wherein said projectors are divided into a first group and a second group, the projectors in said first group projecting said divided images respectively as right-eye images, and the projectors in said second group projecting said divided images respectively as left-eye images, said system further including:
a shutter that interrupts alternately the right-eye images and said left-eye images being projected respectively from said projectors of the first group and the second group;
a pair of glasses adapted to be worn by an observer and having a right-eye lens and a left-eye lens, said glasses being provided with a switch that passes the right-eye image only through said right-eye lens and the left-eye image only through said left-eye lens in synchronous with the alternate interruption of said right-eye images and said left-eye images by said shutter.
8. The system as set forth in claim 3, further including;
an input device for selecting a direction and a speed, and
a scene controller which, in response to said direction and said speed, moves a scene of said divided images represented on said curved screen in said direction and at said speed.
9. The system as set forth in claim 3, further including;
an input device that gives an instruction for changing a content of said divided images, and
a content changer which, in response to said instruction, changes the content of said divided image.
10. A set of projectors adapted in use for a virtual space creation system which combines a plurality of divided images into a single image to be rendered on a curved screen, said projectors projecting said divided images respectively on said curved screen in a partially overlapping relation with each other, and being equipped with filters for adjusting brightness of said divided images for harmonizing the brightness of overlapping areas with the brightness of non-overlapping areas to make said single image seamless, said filters being prepared by the steps of;
(a) producing a screen model reflecting a shape of said curved screen;
(b) setting projection points respectively for projecting therefrom said divided images on said screen model, said projection points being different from each other in conformity with said projectors, respectively;
(c) allocating one of said divided image to a reference image and allocating each of the adjacent divided images to a peripheral image;
(d) setting a view point that is coincident with the projection point of said reference image;
(e) obtaining a 2-dimensional reference area of said reference image that is rendered on said screen model and is viewed from said view point;
(f) obtaining a 2-dimensional peripheral area of said peripheral image that is rendered on said screen model and is viewed from said view point;
(g) extracting an overlapping area of said 2-dimensional reference area that overlaps with the 2-dimensional peripheral area;
(h) making a brightness correction for either said overlapping area or said non-overlapping area with regard to said 2-dimensional reference area;
(i) providing a brightness filter for said reference image that realizes said brightness correction;
(j) allocating another divided image to said reference image and repeating the steps of (d) to (i) for providing said brightness filter for each of said divided images.