A field emission-type electron source (10) is provided with a conductive substrate (1), a semiconductor layer formed on a surface of the conductive substrate (1), at least a part of the semiconductor layer being made porous, and a conductive thin film (7) formed on the semiconductor layer. Electrons injected into the conductive substrate (1) are emitted from the conductive thin film (7) through the semiconductor layer by applying a voltage between the conductive thin film (7) and the conductive substrate (1) in such a manner that the conductive thin film (7) acts as a positive electrode against the conductive substrate (1). The semiconductor layer includes a porous semiconductor layer (6) in which columnar structures (21) and porous structures (25) composed of fine semiconductor crystals of nanometer scale coexist, a surface of each of the structures being covered with an insulating film (22,24). Further, an average dimension of each of the porous structures (25) in a thickness direction of the semiconductor layer is smaller than or equal to 2 xcexcm.

1. Field of the Invention
The present invention relates to a field emission-type electron source using semiconductor materials, for emitting electron beams by means of electrical field emission, and to a manufacturing method thereof, the electron source being applied to a plane light-emitting apparatus, a display, a solid vacuum device and so on.
2. Description of the Prior Art
As a field emission-type electron source, conventionally, there has been known a Spindt-type electrode which is disclosed, for example, in the U.S. Pat. No. 3,665,241 and so on. The Spindt-type electrode is provided with a substrate on which many emitter chips of triangular pyramid shape are disposed, and a gate layer having emitting holes for exposing apexes of the emitter chips to the outside, the gate layer being disposed so as to be insulated to the emitter chips. The Spindt-type electrode can emit electron beams from the apexes of the emitter chips to the outside through the emitting holes by applying high voltage between the emitter chips and the gate layer under a vacuum atmosphere in such a manner that the emitter chips act as negative electrodes against the gate layer.
However, in the Spindt-type electrode, there exists such a problem described below. That is, the manufacturing process of the electrode is complicated, and further it is difficult to construct many emitter chips of triangular shape with higher efficiency. In consequence, if it is applied, for example, to a plane light-emitting apparatus, a display and so on, it may be difficult to enlarge the area of the electron-emitting surface.
Meanwhile, in the Spindt-type electrode, there exists also such another problem described below. That is, in the Spindt-type electrode, the electrical field converges to the apexes of the emitter chips. In consequence, if the degree of vacuum around the apexes of the emitter chips is lower so that residual gas exists thereabout, a part of the residual gas is ionized by the emitted electron beams to become positive ions. Because the positive ions collide to the apexes of the emitter chips, the apexes of the emitter chips suffer damages (for example, damages due to ion impacts). Therefore, the current density and efficiency of the emitted electrons may become unstable, or the lives of the emitter chips may be shortened.
In order to prevent the above-mentioned disadvantages, the Spindt-type electrode is required to use under a higher vacuum atmosphere (about 10xe2x88x925 Pa to about 10xe2x88x926 Pa. In consequence, there may occur such a disadvantage that the cost for sealing it with higher vacuum or for maintaining the higher vacuum, may be increased.
In order to improve the above-mentioned disadvantages, a field emission-type electron source of MIM (Metal Insulator Metal) type or MIS (Metal Insulator Semiconductor) type has been proposed. The former is a flat field emission-type electron source having a laminated structure of (metal)xe2x80x94(insulator film)xe2x80x94(metal) The latter is a flat field emission-type electron source having a laminated structure of (metal)xe2x80x94(insulator film)xe2x80x94(semiconductor). In order to elevate the electron-emitting efficiency of the above-mentioned type of field emission-type electron source (namely, in order to emit more electrons), it is necessary to decrease the thickness of the insulator film. However, if the insulator film becomes thinner to excess, it is feared that dielectric breakdown is caused when voltage is applied between the upper and lower electrodes of the laminated structure. Because there is a certain restriction on decreasing the thickness of the insulator film as described above, there may exist such a problem that its electron-emitting efficiency (electron extracting efficiency) can not be elevated so much.
Moreover, in recent years, as disclosed in the Japanese Laid-Open Patent Publication No. 8-250766, there has been proposed another field emission-type electron source (semiconductor element for emitting cold electrons), in which a porous semiconductor layer (porous silicon layer) is formed by performing anodic oxidation to a surface of a monocrystalline semiconductor substrate such as a silicon substrate or the like, and further a thin metal film is formed on the porous semiconductor layer. In the field emission-type electron source, electrons are emitted by applying voltage between the semiconductor substrate and the thin metal film.
However, in the field emission-type electron source described in the Japanese Laid-Open Patent Publication No. 8-250766, it is difficult to enlarge the area of the electron-emitting surface, because the monocrystalline semiconductor substrate is an essential constructive element. In consequence, it may not be suitable for applying to an apparatus which requests an electron source having a large electron-emitting surface area, such as a flat display apparatus. Meanwhile, in the Japanese Laid-Open Patent Publication No. 9-259795, there is disclosed a construction for achieving a flat type display based on the invention disclosed in the Japanese Laid-Open Patent Publication No. 8-250766.
In each of the above-mentioned field emission-type electron sources, electrons are emitted due to the electrical field produced by applying voltage to the both surfaces of the porous semiconductor layer. In this case, the porous semiconductor layer is composed of many fine pores and the remaining silicon particles while differing from the above-mentioned MIM or MIS. Hereupon, the porosity is 10 to 80%, while the inner diameter of each of the fine pores is 2 to several nm. In the above-mentioned Publication, there is such a description that because the number of atoms in the remaining silicon particles is several tens to several hundreds, an electron emitting phenomenon may be expected due to the quantum size effect. Meanwhile, in the Japanese Laid-Open Patent Publication No. 9-259795, there is such a description that because the electron emission occurs at a position which is very near with the surface of the porous semiconductor layer, it is desirable that the thickness is thinner, in consequence the practically usable range of the thickness may be 0.1 to 50 xcexcm.
However, in the field emission-type electron source described in the Japanese Laid-Open Patent Publication No. 8-250766 or Japanese Laid-Open Patent Publication No. 9-259795, an electron popping phenomenon may be easily caused and further the amount of electrons emitted within the same plane may be easily dispersed. In consequence, if the electron source is applied to a plane light-emitting device or a display, There may occur such a disadvantage that the brightness dispersion or flicker of the screen may grow larger. Meanwhile, when the electron source is applied to the plane light-emitting device or the display, it is necessary to increase the amount of the emitted electrons. Hereupon, if it is intended to increase the amount of the emitted electrons by decreasing the thickness of the porous semiconductor layer, the above-mentioned disadvantages may grow much larger.
The present invention, which has been performed to solve the conventional problems described above, has an object to provide a field emission-type electron source, in which the popping phenomenon or in-plane dispersion of the emitted electrons hardly occurs while the amount of the emitted electrons and the electron-emitting efficiency are higher together, and to provide a manufacturing method of the electron source.
A field emission-type electron source according to the present invention which is preformed to achieve the above-mentioned object, includes (i) a conductive substrate, (ii) a semiconductor layer formed on a surface of the conductive substrate, at least a part of the layer being made porous, and (iii) a conductive thin film formed on the semiconductor layer, wherein (iv) electrons injected into the conductive substrate are emitted from the conductive thin film through the semiconductor layer by applying voltage between the conductive thin film and the conductive substrate in such a manner that the conductive thin film acts as a positive electrode against the conductive substrate. The field emission-type electron source is characterized in that (v) the semiconductor layer includes a porous semiconductor layer in which columnar structures and porous structures composed of fine semiconductor crystals of nanometer scale coexist, the surface of each of the structures being covered with an insulating layer, and (vi) the average dimension of each of the porous structures in the thickness direction of the semiconductor layer is smaller than or equal to 2 xcexcm.
Because the thickness of each of the porous structures is smaller than or equal to 2 xcexcm in the field emission-type electron source, the amount of emitted electrons may be highly stabilized, and further the amount of the emitted electrons may be increased. In consequence, the popping phenomenon, which is a large time-depending fluctuation of the amount of the emitted electrons, may not occur. Moreover, the in-plane dispersion of the amount of the emitted electrons may be reduced.
In order to apply the field emission-type electron source in various ways, it is essential to increase the amount of the emitted electrons. The present inventors have found that it is desirable that the thickness of each of the porous structures is smaller than or equal to 2 xcexcm, in view of the amount of the emitted electrons of the field emission-type electron source.
Hereupon, the conductive substrate according to the present invention includes a semiconductor substrate in which a conductive region is formed by doping impurities into the substrate, and a substrate in which a thin metal film (bottom electrode) is formed on a surface of an insulating substrate such as glass plate.
In the above-mentioned field emission-type electron source, it is preferable that the thin film side end portions of the columnar structures and the thin film side end portions of the porous structures are located on the same position in the thickness direction of the semiconductor layer (namely, the height of the columnar structures being equal to the height of the porous structures at the conductive thin film side). In this case, because comparatively larger irregularity (namely, convex portions and concave portions) is not formed on the surface of the porous semiconductor layer, the conductive thin film of very small thickness formed on the surface of the porous semiconductor layer may cover the porous semiconductor layer with very high covering ratio in an electrically communicated state. In consequence, the porous semiconductor layer and the conductive thin film are electrically connected to each other. Further, because the covering ratio for the porous structures is higher, the necessary electrical field may be effectively applied to the porous structures. In consequence, its properties such as the amount of the emitted electrons or the electron-emitting efficiency may be efficiently improved.
In the above-mentioned field emission-type electron source, it is preferable that the porous semiconductor layer is composed of porous polycrystalline silicon formed by the anodic oxidation process. In this case, the columnar structures and the porous structures can be formed by a single step by performing the anodic oxidation to the polycrystalline silicon. Therefore, the manufacturing process may be simplified. Further, the formation or anodic oxidation of the polycrystalline silicon layer is advantageous for enlarging the area of the electron-emitting surface. Particularly, if there exist grains (columnar structures) which have grown to the columnar shapes, the pore formations progress along the grains. In this case, the angles of the porous structures in their depth direction become approximately perpendicular to the conductive substrate. In consequence, the electrical field in the porous structures becomes approximately perpendicular to the substrate. Because the emission of electrons is dominated by the electrical field in the porous structures, the electrons are emitted in the direction perpendicular to the substrate in this case. In consequence, the dispersion of the emitting-angles of the electrons is decreased so that a higher definition can be achieved when it is applied to a display or the like.
In the above-mentioned field emission-type electron source, it is preferable that the difference between the maximum dimension and minimum dimension of the porous structures in the thickness direction of the semiconductor layer is smaller than or equal to 0.5 xcexcm (namely, the thickness dispersion of the porous structures being smaller than or equal to 0.5 xcexcm). If the thickness dispersion of the porous structures is smaller, the electrical field applied to the porous structures is uniformed so that the in-plane distribution of the amount of the emitted electrons may be restrained. Particularly, when the columnar structures and the porous structures are provided to prevent occurrence of the popping phenomenon etc. and the thickness of each of the porous structures is smaller than or equal to 2 xcexcm, an extreme dispersion of the intensity of the electrical field does not occur if the thickness dispersion of the porous structures is smaller than or equal to 0.5 xcexcm. In consequence, the amount of the emitted electrons within the same plane may be comparatively uniformed.
In the above-mentioned field emission-type electron source, it is preferable that the thickness of the porous semiconductor layer is approximately equal to the thickness of the semiconductor layer disposed between the conductive thin film and the conductive substrate. In this case, the voltage loss does not occur in a portion which is not made porous. In consequence, the amount of the emitted electrons is increased when the same voltage is applied so that the electron-emitting efficiency may be elevated. Therefore, when the field emission-type electron source is applied to a display or the like, the electrical demand of the display may be reduced.
In the above-mentioned field emission-type electron source, it is preferable that an anticorrosive conductive layer, which has an anticorrosion against an electrolyte for the anodic oxidation process used for making the semiconductor layer porous, is provided on the surface of the conductive substrate at the semiconductor layer side. In this case, the conductive substrate (substrate itself or bottom electrode) may not corroded by the electrolyte. In consequence, the electrical field is effectively applied to the porous structures so that the amount of the emitted electrons may not decreased. Further, it is prevented that an inferior element is produced due to a snap of the bottom electrode.
In the above-mentioned field emission-type electron source, it is preferable that a low-resistance layer of predetermined thickness is provided on the thin film side end portion of the porous semiconductor layer in the thickness direction of the semiconductor layer, the low-resistance layer having a lower resistance in comparison with other parts of the porous semiconductor layer. In this case, the low-resistance layer provided in the surface portion of the porous semiconductor layer acts as a mimic electrode. Therefore, even if the porous semiconductor layer does not partially contact to the conductive thin film, the electrical potential in the whole surface portion of the porous semiconductor layer is uniformed in the same plane. In this case, because the electrical field is uniformly applied into the porous semiconductor layer at the same plane, the dispersion of the amount of the emitted electrons at the same plane may be restrained. Therefore, when the field emission-type electron source is applied to a display, the bright dispersion on the screen may become smaller.
In the above-mentioned field emission-type electron source, it is preferable that the thickness of the low-resistance layer is smaller than the mean free path of the electrons in the semiconductor forming the low-resistance layer. In this case, the deterioration of the electron-emitting efficiency due to the low-resistance layer may be restrained.
In the above mentioned field emission-type electron source, the low-resistance layer may be composed of a low-porosity layer having a smaller porosity in comparison with other parts of the porous semiconductor layer. In this case, because the irregularity of the surface of the porous semiconductor layer becomes less, it may be restrained that the electrical field converges at the apexes of the convex portions or the bottom of the concave portions on the surface of the porous semiconductor layer. In consequence, when the field emission-type electron source is applied to a display etc., it may be prevented that only specific spots become bright. Further, the brightness dispersion in the same plane may become smaller.
In the above-mentioned field emission-type electron source, the low-resistance layer may be composed of a re-crystallized layer which is formed by re-crystallizing a surface portion of the porous semiconductor layer. In this case, the irregularity of the surface of the porous semiconductor layer becomes less so that it may be restrained that the electrical field converges at the apexes of the convex portions or the bottom of the concave portions on the surface of the porous semiconductor layer. In consequence, when the field emission-type electron source is applied to a display etc., it may be prevented that only specific spots become bright. Further, the brightness dispersion in the same plane may become smaller.
In the above-mentioned field emission-type electron source, the low-resistance layer may be composed of an impurity-implanted layer which is formed by implanting impurity ions into the porous semiconductor layer through a surface of the porous semiconductor layer. In this case, it may be easy to control the concentration or distribution of the impurity in the low-resistance layer.
In the above-mentioned field emission-type electron source, the low-resistance layer may be composed of an impurity-diffused layer which is formed by diffusing an impurity into the porous semiconductor layer through a surface of the porous semiconductor layer. In this case, it may be easy to enlarge the area of the electron-emitting surface in comparison with the case that the impurity is implanted by the ion implantation process.
In the above-mentioned field emission-type electron source, it is preferable that the thin film side surface of each of the porous structures is parallel to the surface of the conductive substrate. In this case, the electrical field in the porous structures is applied to the conductive substrate in the direction perpendicular to the substrate. In consequence, the electrons, which are emitted in the direction approximately perpendicular to the surface of the porous structure, are also emitted in the direction approximately perpendicular to the surface of the conductive substrate. As the result, the in-plane distribution of the emitting-angles of the electrons is further decreased. That is, the directions of the emitted electrons uniformly become perpendicular to that. In consequence, higher definition can be achieved when the field emission-type electron source is applied to a display or the like.
A method of manufacturing a field emission-type electron source according to the present invention is a process for producing the field emission-type electron source including (i) a conductive substrate, (ii) a semiconductor layer formed on a surface of the conductive substrate, which includes a porous semiconductor layer in which columnar structures and porous structures composed of fine semiconductor crystals of nanometer scale coexist, a surface of each of the structures being covered with an insulating film; and the average thickness of the porous structures being smaller than or equal to 2 xcexcm; and (iii) a conductive thin film formed on the semiconductor layer, wherein (iv) electrons injected into the conductive substrate are emitted from the conductive thin film through the semiconductor layer by applying a voltage between the conductive thin film and the conductive substrate in such a manner that the conductive thin film acts as a positive electrode against the conductive substrate. The manufacturing method is characterized in that it includes the step of (v) making the semiconductor layer porous by means of an anodic oxidation process to form the porous semiconductor layer, wherein (vi) the thickness of the porous semiconductor layer is controlled by adjusting the depth of the semiconductor layer to be made porous by means of an amount of electric charges during a period that the semiconductor layer acts as a positive electrode in the step. According to the manufacturing method, the thickness of the porous semiconductor layer may be easily controlled by means of the electric charges during the anodic oxidation process so as to become a predetermined value.
In the above-mentioned method of manufacturing the field emission-type electron source, it is preferable that pulse current or pulse voltage is applied between the counter electrode and the conductive substrate on which the semiconductor layer to be made porous is formed in such a manner that a period that the conductive substrate acts as a positive electrode and a period that the current or voltage is off state are mutually set, while the thickness of the porous semiconductor layer is controlled by changing the amount of electric charges during the period that the semiconductor layer acts as the positive electrode. In this case, the thickness of the porous semiconductor layer may be easily controlled so as to become the predetermined value. Further, because the anodic oxidation process can be intermittently performed by the pulse treatment when the porous semiconductor layer of predetermined porosity is formed with larger current density, the rate of progressing the anodic oxidation can be set to a comparatively smaller value. Therefore, the thickness of the porous semiconductor layer may easily controlled in comparison with the case that the current is continuously fed.
In the above-mentioned method of manufacturing the field emission-type electron source, pulse current or pulse voltage may be applied between the counter electrode and the conductive substrate on which the semiconductor layer to be made porous is formed in such a manner that a period that the conductive substrate acts as a positive electrode and a period that the conductive substrate acts as a negative electrode are mutually set, while the thickness of the porous semiconductor layer may be controlled by changing the amount of electric charges per one pulse during the period that the semiconductor layer acts as the negative electrode. In this case, the pore formation in the semiconductor layer progresses when the semiconductor layer acts as the positive electrode, and while the condition of the pore formation disperses in accordance with the surface shape or state of the semiconductor layer. When the polarity is reversed then so that the semiconductor layer acts as the negative electrode, the electrical field converges at the portion where the pore formation has rapidly progressed so that carriers converge at the same portion. In consequence, a large amount of gas is produced at the portion by the electrolysis process. Thus, at the portion where the gas has been produced, the contact between the portion and the electrolyte is snapped so that the pore formation does not progress when the semiconductor layer acts as the positive electrode next. The above-mentioned steps are repeated so that the thickness of the porous structures is uniformed all over the plane. The degree of the uniformity can be controlled by means of the amount of the electric charges during the period that the semiconductor layer acts as the negative electrode. If the thickness of the porous structures is uniformed, the electron source, in which the in-plane distribution of the amount of the emitted electrons is extremely small, may be achieved.
Another method of manufacturing a field emission-type electron source according to the present invention is a process for producing the field emission-type electron source including (i) a conductive substrate, (ii) a semiconductor layer formed on a surface of the conductive substrate, which includes a porous semiconductor layer in which columnar structures and porous structures composed of fine semiconductor crystals of nanometer scale coexist, a surface of each of the structures being covered with an insulating film; and the average thickness of the porous structures being smaller than or equal to 2 xcexcm; and (iii) a conductive thin film formed on the semiconductor layer, wherein (iv) electrons injected into the conductive substrate are emitted from the conductive thin film through the semiconductor layer by applying a voltage between the conductive thin film and the conductive substrate in such a manner that the conductive thin film acts as a positive electrode against the conductive substrate. In the manufacturing method, (v) a low-resistance layer of predetermined thickness is provided on a thin film side end portion of the porous semiconductor layer in the thickness direction of the semiconductor layer, the low-resistance layer having a smaller porosity and a lower resistance in comparison with other parts of the porous semiconductor layer. Further, the manufacturing method is characterized in that it includes the steps of (vi) forming the porous semiconductor layer by decreasing the porosity of a surface portion of the semiconductor layer in comparison with the porosity of other parts of the semiconductor layer, after the semiconductor layer has been formed on the conductive substrate, (vii) forming the porous semiconductor layer including the low-resistance layer by oxidizing or nitrifying the porous semiconductor layer, and (viii) forming the conductive thin film on the porous semiconductor layer. According to the manufacturing method, the low-resistance layer may be provided without independently adding another step for forming the, low-resistance layer. Moreover, the field emission-type electron source, in which the in-plane dispersion of the emitted electrons is smaller, can be achieved with a lower cost.
If the semiconductor layer is made porous by means of the anodic oxidation process in the above-mentioned method of manufacturing the field emission-type electron source, it is preferable that the current density is set to a smaller value during a predetermined initial period of the anodic oxidation process, and then the current density is increased after the predetermined initial period. During the anodic oxidation process, there exist an interrelation between the current density and the porosity. Meanwhile, the resistance changes in accordance with the degree of the porosity. Therefore, the resistance of the low-resistance layer can be controlled by controlling the current density.
When the semiconductor layer is made porous by means of the anodic oxidation process in the above-mentioned method of manufacturing the field emission-type electron source, the light power applied to the surface of the semiconductor layer may be smaller during a predetermined initial period of the anodic oxidation process, and then the light power may be increased after the predetermined initial period. During the anodic oxidation process, there exist an interrelation between the light power and the porosity. On the other hand, the resistance changes in accordance with the degree of the porosity. Therefore, the resistance of the low-resistance layer can be controlled by controlling the light power applied to the surface of the semiconductor layer.
If the low-resistance layer is composed of a re-crystallized layer formed by re-crystallizing a surface portion of the porous semiconductor layer in the above-mentioned method of manufacturing the field emission-type electron source, there may be provided a step for forming the porous semiconductor layer by making the semiconductor layer porous after the semiconductor layer has been formed on the conductive substrate, and another step for re-crystallizing the surface portion of the porous semiconductor layer by means of the laser anneal process, instead of the above-mentioned step of (vi) forming the porous semiconductor layer by decreasing the porosity of the surface portion of the semiconductor layer in comparison with the porosity of the other parts of the semiconductor layer after the semiconductor layer has been formed on the conductive substrate. In this case, the low-resistance layer can be easily provided, comparatively. Meanwhile, the field emission-type electron source, in which the in-plane dispersion of the emitted electrons is smaller, can be achieved with a lower cost.
Meanwhile, if the low-resistance layer is composed of an impurity-implanted layer formed by implanting impurity ions into the porous semiconductor layer in the above-mentioned method of manufacturing the field emission-type electron source, there may be provided a step for forming the porous semiconductor layer by making the semiconductor layer porous after the semiconductor layer has been formed on the conductive substrate, and another step for implanting the impurity ions into the porous semiconductor layer from the surface side of the porous semiconductor layer by means of the ion implantation process. In this case, the low-resistance layer can be formed with a good controllability. Meanwhile, the field emission-type electron source, in which the in-plane dispersion of the emitted electrons is smaller, can be achieved with a lower cost.
Moreover, if the low-resistance layer is composed of an impurity-diffused layer formed by diffusing an impurity into the porous semiconductor layer in the above-mentioned method of manufacturing the field emission-type electron source, there may be provided a step for forming the porous semiconductor layer by making the semiconductor layer porous after the semiconductor layer has been formed on the conductive substrate, and another step for diffusing the impurity into the porous semiconductor layer from the surface of the porous semiconductor layer by means of the thermal diffusion process. In this case, the low-resistance layer can be easily provided comparatively, while enlarging the area of the electron-emitting surface. Meanwhile, the field emission-type electron source, in which the in-plane dispersion of the emitted electrons is smaller, can be achieved with a lower cost.
A further method of manufacturing a field emission-type electron source according to the present invention is a process for producing the field emission-type electron source including (i) a conductive substrate, (ii) a semiconductor layer formed on a surface of the conductive substrate, which includes a porous semiconductor layer in which columnar structures and porous structures composed of fine semiconductor crystals of nanometer scale coexist, a surface of each of the structures being covered with an insulating film; and the average thickness of the porous structures being smaller than or equal to 2 xcexcm; and (iii) a conductive thin film formed on the semiconductor layer, wherein (iv) electrons injected into the conductive substrate are emitted from the conductive thin film through the semiconductor layer by applying a voltage between the conductive thin film and the conductive substrate in such a manner that the conductive thin film acts as a positive electrode against the conductive substrate. The manufacturing method is characterized in that it includes the step of forming the porous semiconductor layer in which the surface of each of the porous structures is parallel to the surface of the conductive substrate by performing the anodic oxidation process to the semiconductor layer after the surface of the semiconductor layer has been smoothed. According to the manufacturing method, the surface of the porous semiconductor layer is smoothed. In consequence, the surface potential is approximately uniformed during the anodic oxidation process so that the rate of progressing the anodic oxidation process is also approximately uniformed. In consequence, the depth of the porous structures becomes approximately uniform so that the electrical field is applied approximately uniformly. Therefore, the field emission-type electron source, in which the in-plane dispersion of the emitted electrons is smaller, can be achieved with a lower cost. Meanwhile, the direction of progress of the anodic oxidation becomes approximately perpendicular to the conductive substrate so that the electrical field in the porous structures becomes approximately perpendicular to the conductive substrate. In consequence, the progressing directions of the emitted electrons become uniformly perpendicular to that. Further, because the distribution of the emitting angles of the electrons is very small, a display with high definition may be achieved.

Field emission-type electron source and manufacturing method thereof


A new child car seat with air bag protection bar is provided for protecting a child in event of the release of an air bag. Included is a car seat portion having a seat portion and a back portion. The car seat portion includes a harness strap for securing a child therein. A lower end of the back portion has a slot therethrough for receiving a seat belt of a vehicle therethrough to facilitate securement of the car seat portion within the vehicle. A restraint system is provided including a pair of inner vertical brackets secured on opposing sides of the back portion of the car seat portion. The restraint system includes a pair of outer vertical brackets slidably received within the inner vertical brackets. The restraint system includes a pair of horizontal supports pivotally coupled with upper ends of the outer vertical brackets. An outer portion of the horizontal supports have a channel formed therein. An outer end of the horizontal supports have an aperture therethrough. The restraint system includes a cross bar extending between the outer portions of the horizontal supports.

1. Field of the Invention
The present invention relates to child seats and more particularly pertains to a new child car seat with air bag protection bar for protecting a child in event of the release of an air bag.
2. Description of the Prior Art
The use of child seats is known in the prior art. More specifically, child seats heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art child seats include U.S. Pat. No. 5,108,152 to Reilly et al.; U.S. Pat. No. 3,992,028 to Abe et al.; U.S. Pat. No. 4,690,456 to Chiba et al.; U.S. Pat. No. 5,324,071 to Gotomyo et al.; U.S. Pat. No. 5,282,648 to Peterson; and U.S. Pat. No. Des. 334,847 to Takahashi et al.
While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not disclose a new child car seat with air bag protection bar. The inventive device includes a car seat portion having a seat portion and a back portion. The car seat portion includes a harness strap for securing a child therein. A lower end of the back portion has a slot therethrough for receiving a seat belt of a vehicle therethrough to facilitate securement of the car seat portion within the vehicle. A restraint system is provided including a pair of inner vertical brackets secured on opposing sides of the back portion of the car seat portion. The restraint system includes a pair of outer vertical brackets slidably received within the inner vertical brackets. The restraint system includes a pair of horizontal supports pivotally coupled with upper ends of the outer vertical brackets. An outer portion of the horizontal supports have a channel formed therein. An outer end of the horizontal supports have an aperture therethrough. The restraint system includes a cross bar extending between the outer portions of the horizontal supports.
In these respects, the child car seat with air bag protection bar according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of protecting a child in event of the release of an air bag.

Child car seat with air bag protection bar


A semiconductor device includes 1) a conductive pipe including an inner surface forming an inner space shaping a path of an insulative cooling refrigerant liquid and an outer surface including a plane potion partially formed thereof, 2) a power semiconductor element fixed onto the plane portion of the conductive pipe through a bonding layer such as solder, 3) a first external connecting terminal including an inner lead part including a tip portion bonded onto the plane portion of the conductive pipe and an outer lead part continuous with the inner lead part, 4) a second external connecting terminal which is in the state of floating above the outer surface, and 5) a mold resin covering the whole surface of the power semiconductor element, the whole of the inner lead parts of the external connecting terminals, and the whole of the outer surface covering a central portion of the conductive pipe.

1. Field of the Invention
The present invention relates to a cooling technique of a power semiconductor device.
2. Description of the Background Art
In order to dissipate heat generated from a power semiconductor element to the exterior, a conventional power semiconductor device has a copper plate bonded to a back surface of the power semiconductor element with a brazing material and a ceramic plate bonded to the copper plate with a brazing material provided therein, a back surface of the ceramic plate being in contact with an external cooling system (a cooling plate having a path for passing a refrigerant liquid formed therein) through adhesion grease. The conventional power semiconductor device is disclosed in Japanese Patent Application Laid-Open Nos. 2002-270748, 2002-093974 and 2001-332679.
In the conventional semiconductor device, members for the copper plate and the ceramic plate need to be used to attach the cooling system to the semiconductor device, and grease needs to be coated at the time of the attachment to ensure a contact surface and reduce contact thermal resistance. This sort of structure has been an obstacle in seeking size reduction of the device while further increasing the cooling efficiency to heat generated from the power semiconductor element.

Semiconductor device for pipe for passing refrigerant liquid


Antenna designs are disclosed that exhibit both high bandwidth and efficiency. A first aspect of the invention concerns the form factor of the antenna; a second aspect of the invention concerns the ease with which the antenna is manufactured; and a third aspect concerns the superior performance exhibits by the antenna across a large bandwidth.

1. Technical Field
The invention relates generally to antennas for wireless or RF (radio frequency) communications systems. More particularly, the invention relates to antenna designs that provide both high bandwidth and efficiency.
2. Description of the Background Art
It is necessary to equip receivers, transmitters, and transceivers with antennas that efficiently radiate, i.e. transmit and/or receive desired signals to/from other elements of a network to provide wireless connectivity and communication between devices in a wireless network, such as in a wireless PAN (personal area network), a wireless LAN (local area network) a wireless WAN (wide area network), a cellular network, or virtually any other radio network or system. For such antennas as are used in, for example, the 2.4 GHz and 5.0 GHz bands, it is a challenge to provide an antenna that exhibits high efficiency and that is easy to manufacture.


The invention provides a protective coating composition for use on substrates including steel, aluminum, iron and the like. This composition further provides abrasion resistance, electrical resistance, ultra-violet protection, corrosion resistance and heat resistance. It can be particularly useful for coating high temperature stacks, mufflers, manifolds, boilers, ovens, furnaces, steam lines, heat exchangers, barbecue equipment, cooking utensils and other parts that require such powder coating composition. This composition further provides good initial adhesion.. This invention also provides a powder coating composition containing a hydroxyl-functional silicone resin, a glycidyl-functional acrylic resin and an optional flow control agent.

Powder coating compositions are a well known and established art. A variety of articles are routinely powder coated by dipping or tumbling them in a suspended or static bed of resinous powder coating or by spray or sprinkling. The article on which the coating is applied is then heated to form a cured powder coating. These coatings have been shown to be particularly useful on metal surfaces including steel, aluminum and iron.
Various powder coating compositions are available that have been used in heat-resistant applications. For example, it is known in the art that aromatic epoxy resins are used to provide good heat resistance. Epoxy compositions or epoxy and silicone mixtures have also been used in the industry for the same purpose. An example of a silicone coating composition is shown in U.S. Pat. No. 5,422,396 (Daly et al.). However, this composition, along with the other silicone based powder coating compositions, rely on the condensation of the silicone resin with another resin or itself to form the coating composition.
Additional references which describe the preparation of heat-resistant protective coatings are described below:
U.S. Pat. No. 4,877,837 (Reising et al.) discloses powder-based compositions comprising glycidyl functional acrylic polymers admixed with silicone having hydroxyl functional groups. The compositions may contain additives such as flow agents, outgas agents and filler pigments (i.e. hydrated silicates of aluminum and calcium metasilicate) and are cured at a temperature between 180.degree. C.-200.degree. C.). PA1 U.S. Pat. No. 4,446,259 (Vasta) discloses coating compositions in a liquid carrier, which can be cured at ambient temperatures, comprising glycidyl functional acrylic polymers admixed with a reactive polysiloxane. The coatings may contain additives such as metal oxides, metallic pigments and trace amounts of multivalent metal ions including tin and zinc. Vasta also discloses fluorocarbon-based powder compositions which are baked at 200.degree. C.-345.degree. C. for about 2 hours to provide a coating 25-75 microns thick. PA1 Other related patents include: U.S. Pat. No. 4,404,042 (Okada et al.); U.S. Pat. Nos. 4,657,963 and 4,746,568 (Matsumoto et al.); U.S. Pat. No. 4,879,344 (Woo et al); and U.S. Pat. No. 5,087,286 (Fukuda et al.). PA1 1) at least one polysiloxane, preferably a hydroxyl-functional siloxane; and PA1 2) at least one adhesion promoter. PA1 1) at least one acrylic polymer; PA1 2) at least one polysiloxane; and PA1 3) at least one inorganic compound,
A drawback with the prior art references relates to the protective coatings appearance and protective nature when elevated temperatures are used to cure high-film-build powder-based compositions. For example, when said compositions are cured at elevated temperatures, condensation and thermal decomposition by-products often generate gases which can form pinholes, cracks and craters in the protective coating. These defects can be detrimental to coating properties including aesthetics, heat resistance and corrosion resistance and typically limit the coating thickness to less than about 100 microns.
In attempting to overcome this disadvantage, users of these silicone based powder coating compositions have to allow for long cure times at low temperatures or perform a controlled cure that occurs by slowly increasing the oven temperature. Some powder coatings comprising silicone resins and its blends also have poor storage stability, i.e., the powder coating composition clumps up, cohesively bonds or sinters within 48 hours of storage.
Another problem which has existed in the application of thermally stable silicone compositions to substrates is that the coating compositions (a coating composition which has been powder coated, with the coating melted and cured to a continuous film at temperatures up to 230.degree. C.) have exhibited poor initial adhesion to the substrates. Even though the adhesion of undamaged coatings to the substrates tends to improve with elevated temperatures during use (e.g., temperatures above 280.degree. C.), damage can occur before such use, and additional curing of the initially coated and cured material is time consuming and expensive for the manufacturer. For example, when thermoset silicone powder coated materials have been dropped or scratched, the coatings may readily peel from the substrate or flake off the substrate. It is desirable to provide a powder coating composition which, in addition to providing good thermal resistance, also provides good initial bond strength to substrates.
There has therefore been a need for a powder coating that provides high heat resistance, does not significantly pit, can be applied with a generally high film build without significantly affecting the coating, and that has good initial bond strength to substrates.

Heat resistant powder coating composition

H. B. Fuller Licensing & Financing, Inc.


A display device implemented with a spatial light modulator (SLM) comprising a plurality of pixel elements arranged in array to modulate incident light and display an image, wherein each of the pixel elements comprises a movable electrode and a stationary electrode; a drive circuit connected to the movable electrode and receives image data for applying a voltage applied to control the movable electrode in accordance with image data, and a voltage application circuit for applying and controlling a voltage applied to the stationary electrode to control a moving speed of the movable electrode.

1. Field of the Invention
The present invention relates generally to a display device. More particularly, this invention relates to a micromirror device with the pixel elements arranged in an array modulating an incident light with the modulation states of pixel elements display image data.
2. Description of the Related Art
After the dominance of CRT technology in the display industry for over 100 years, Flat Panel Displays (hereafter FPD) and Projection Displays have gained popularity because the FDP display implements a more compact image projecting system while projecting images on a larger display screen. Of several types of projection displays, projection displays using micro-displays are gaining recognition among the consumers because of their high picture quality and a lower cost than FPDs. There are two types of micro-displays used for projection displays on the market, i.e., micro-LCDs (Liquid Crystal Displays) and micromirror technology. Because the micromirror devices display images with an un-polarized light, the images projected by the micromirror device have a brightness superior to that of micro-LCDs, which use polarized light.
Even though there have been significant advances made in recent years in technologies implementing an electromechanical mirror device as a spatial light modulator (SLM), there are still limitations and difficulties when it is employed to display a high quality image. Specifically, when the images are digitally controlled, the image quality is adversely affected due to the fact that the images are not displayed with a sufficient number of gray scales.
An electromechanical mirror device implemented as the spatial light modulator (SLM) for an image projection apparatus has recently drawn a considerable amount of popular interest. The electromechanical mirror device commonly employs a relative large number of micromirrors configured as a "mirror array". In general, the number of mirror elements ranges from 60,000 to several millions, placed on the surface of a substrate in an electromechanical mirror device.
Referring to FIG. 1A, an image display system 1 including a screen 2 is disclosed in a relevant U.S. Pat. No. 5,214,420. A light source 10 is used to generate light beams to project illumination for the display images on the display screen 2. The light 9 projected from the light source is further concentrated and directed toward lens 12 by way of mirror 11. Lenses 12, 13 and 14 form a beam columnator operative to columnate the light 9 into a column of light 8. A spatial light modulator 15 is controlled by a computer 19 through data transmitted over data cable 18 to selectively redirect a portion of the light from path 7 toward lens 5 to display on screen 2. FIG. 1B shows a SLM 15 that has a surface 16 that includes an array of switchable reflective elements 17, 27, 37, and 47, each of these reflective elements is attached to a hinge 30. When the element 17 is in an ON position, a portion of the light from path 7 is reflected and redirected along path 6 to lens 5 where it is enlarged or spread along path 4 to impinge on the display screen 2 to form an illuminated pixel 3. When the element 17 is in an OFF position, the light is reflected away from the display screen 2 and, hence, pixel 3 is dark.
The on-and-off states of the micromirror control scheme, as that implemented in the U.S. Pat. No. 5,214,420 and in most conventional display systems, impose a limitation on the quality of the display. Specifically, applying the conventional configuration of a control circuit limits the gray scale gradations produced in a conventional system (PWM between ON and OFF states), limited by the LSB (least significant bit, or the least pulse width). Due to the ON-OFF states implemented in the conventional systems, there is no way of providing a shorter pulse width than the duration represented by the LSB. The least quantity of light, which determines the gray scale, is the light reflected during the least pulse width. The limited levels of the gray scale lead to a degradation of the display image.
Specifically, FIG. 1C is a schematic circuit diagram to illustrate a control circuit implemented in a mirror element for controlling a micromirror according to U.S. Pat. No. 5,285,407. The control circuit includes memory cell 32. Various transistors are referred to as "M*" where "*" designates a transistor number and each transistor is an insulated gate field effect transistor. Transistors M5, and M7 are p-channel transistors; transistors, M6, M8, and M9 are n-channel transistors. The capacitances, C1 and C2, represent the capacitive loads in the memory cell 32. The memory cell 32 includes an access switch transistor M9 and a latch 32a based on a Static Random Access Memory (SRAM) switch design. All access transistors M9 on a Row line receive a DATA signal from a different Bit-line 31a. The particular memory cell 32 is accessed for writing a bit to the cell by turning on the appropriate row select transistor M9, using the ROW signal functioning as a Word-line. Latch 32a consists of two cross-coupled inverters, M5/M6 and M7/M8, which permit two stable states that include a state 1 when is Node A high and Node B low, and a state 2 when Node A is low and Node B is high.
The control circuit positions the micro-mirrors to be at either an ON or an OFF angular orientation, as that shown in FIG. 1A. The brightness, i.e., the number of gray scales of display for a digitally control image system, is determined by the length of time the micro-mirror stays at an ON position. The length of time a micromirror is in an ON position is controlled by a multiple bit word. FIG. 1D shows the "binary time intervals" when controlling micromirrors with a four-bit word. As shown in FIG. 1D, the time durations have relative values of 1, 2, 4, 8, which in turn define the relative brightness for each of the four bits where "1" is the least significant bit and "8" is the most significant bit. According to the control mechanism as shown, the minimum controllable differences between gray scales for showing different levels of brightness is a represented by the "least significant bit" that maintains the micromirror at an ON position.
For example, assuming n bits of gray scales, one time frame is divided into 2″−1 equal time periods. For a 16.7-millisecond frame period and n-bit intensity values, the time period is 16.7/(2″−1) milliseconds.
Having established these times for each pixel of each frame, pixel intensities are quantified such that black is a 0 time period, the intensity level represented by the LSB is 1 time period, and the maximum brightness is 2″−1 time periods. Each pixel's quantified intensity determines its ON-time during a time frame. Thus, during a time frame, each pixel with a quantified value of more than 0 is ON for the number of time periods that correspond to its intensity. The viewer's eye integrates the pixel brightness so that the image appears the same as if it were generated with analog levels of light.
For controlling deflectable mirror devices, the PWM applies data to be formatted into "bit-planes", with each bit-plane corresponding to a bit weight of the intensity of light. Thus, if the brightness of each pixel is represented by an n-bit value, each frame of data has the n-bit-planes. Then, each bit-plane has a 0 or 1 value for each mirror element. According to the PWM control scheme described in the preceding paragraphs, each bit-plane is independently loaded and the mirror elements are controlled according to bit-plane values corresponding to the value of each bit during one frame. Specifically, the bit-plane according to the LSB of each pixel is displayed for 1 time period.
FIG. 2 is an outline diagram showing the cross-section of a conventional mirror element.
As shown in FIG. 2, a plurality of pixel elements 610 is arrayed in a grid at each of the positions where vertically extended bit lines 621 and horizontally extended word lines 631 cross each other.
Each pixel element 610 comprises a mirror 611, which tilts freely, supported by a substrate (not shown in a drawing herein) by way of a hinge 613.
On the substrate, an ON electrode 615 and an OFF electrode 616 are symmetrically placed at positions sandwiching the hinge 613 between them.
The ON electrode 615, when a predetermined electric potential (noted simply as "potential" hereinafter) is applied thereto, attracts mirror 611 with a coulomb force and tilts it to a position abutting a stopper (not shown in a drawing herein). This causes incident light incident to the mirror 611 to be reflected to the light path of an ON position, which matches the optical axis of a projection optical system (not shown in a drawing herein).
The OFF electrode 616, when a predetermined potential is applied thereto, attracts mirror 611 with a coulomb force and tilts it to a position abutting a stopper equipped on the OFF side. This causes incident light incident to the mirror 611 to be reflected to the light path of an OFF position that is shifted from the optical axis of the above described projection optical system.
An ON capacitor 615a is connected to the ON electrode 615; it is also connected to a bit line 621-1 by way of a gate transistor 615b that is constituted by a field effect transistor (FET) or the like.
Furthermore, an OFF capacitor 616a is connected to the OFF electrode 616; it is also connected to a bit line 621-2 by way of a gate transistor 616b that is constituted by a field effect transistor (FET) or the like.
Opening and closing of the gate transistor 615b and gate transistor 616b are controlled through the word line 631.
Specifically, a single horizontal row of pixel elements 610 lined up with an arbitrary word line 631 is simultaneously selected, and the charging and discharging of capacitance to and from the ON capacitor 615a and OFF capacitor 616a is controlled by a bit line driver unit and a word line driver unit. Thereby the individual ON/OFF controls of the mirror 611 within the present single horizontal row are carried out.
In other words, the ON capacitor 615a and gate transistor 615b placed on the side where the ON electrode 615 is placed constitute a DRAM-structured memory cell M1.
Likewise, the OFF capacitor 616a and gate transistor 616b placed where the OFF electrode 616 is placed constitute a DRAM-structured memory cell M2.
With this configuration, the tilting operation for the mirror 611 is controlled in accordance with, for example, the presence and absence of data written to the respective memory cells of the ON electrode 615 and OFF electrode 616.
Incidentally, the configuration shown in FIG. 2 requires one mirror element with two drive circuits to be connected to two address electrodes.
This requirement creates a problem, however. The area occupied by the drive circuits that are connected to the respective address electrode are placed on the substrate. Therefore, if a very large number of mirror elements must be placed on the substrate, in order to produce a video image with a very high resolution, such as super high definition television (super HD TV), the area of the drive circuit occupying the substrate increases with the number of mirror elements. This eventually results in the need to enlarge the substrate itself and, thus, in a larger micromirror device at a high cost, which is a shortcoming of the configuration.

Display device with an addressable movable electrode


In certain embodiments, a key is received, wherein a value is capable of being generated from the key and an input string corresponding to a packet. Intermediary values are computed based on substrings of the key and substrings of the input string. The intermediary values are stored in a data structure, wherein the stored intermediary values are capable of being used to generate the value.

Receive side scaling (RSS) is a feature in an operating system that allows network adapters that support RSS to direct packets of certain Transmission Control Protocol/Internet Protocol (TCP/IP) flow to be processed on a designated Central Processing Unit (CPU), thus increasing network processing power on computing platforms that have a plurality of processors. Further details of the TCP/IP protocol are described in the publication entitled "Transmission Control Protocol: DARPA Internet Program Protocol Specification," prepared for the Defense Advanced Projects Research Agency (RFC 793, published September 1981). The RSS feature scales the received traffic across the plurality of processors in order to avoid limiting the receive bandwidth to the processing capabilities of a single processor.
In order to direct a packet to the appropriate CPU, a hash function is defined that takes as an input the header information included in the packet, and outputs a hash value used to identify the CPU on which the packet should be processed by a device driver and the TCP/IP stack. The hash function is run across the connection-specific information in each incoming packet header. Based on the hash value, each packet is assigned to one CPU of a plurality of CPUs for execution.


A water heater system includes a water heater having a first water outlet and a second water outlet. The water heater system further includes a flow detection device coupled to the first water outlet to detect a water flow through the first water outlet. The water heater system also includes a flow control valve fluidly coupled to the second water outlet. The flow control valve is configured to control a flow of water through the second water outlet based on whether the water flow through the first water outlet is detected by the flow detection device.

Some water heaters provide heated water for domestic uses as well as hydronic heating uses. For example, domestic uses may include cooking, washing, bathing, etc. To illustrate, a water heater may provide heated water to faucets, shower heads, a dishwasher, a washing machine, etc. The use of heated water for hydronic heating may reduce the amount of heated water available for domestic use. Similarly, the use of heated water for domestic purposes may reduce the amount of water available for hydronic heating. In some cases, it may be desirable to control the amount of heated water that is provided by a water heater for different uses. For example, it may be desirable to reduce or stop the availability of heated water from a water heater for hydronic heating or other auxiliary uses when heated water from the water heater is being used for domestic purposes such as bathing, etc. In some cases, it may be desirable to reduce or stop the availability of heated water for domestic use when hydronic heating or other auxiliary use is needed or preferred. Thus, a solution that enables a control of the usage of heated water from a water heater among a domestic use and hydronic/auxiliary use may be desirable.

This patent is subject to a terminal disclaimer.


In some examples, a laser-based ophthalmological surgical system (hereinafter “system”) includes a therapeutic radiation source configured to emit therapeutic radiation at a first intensity during a therapeutic portion and to emit probe radiation with a second intensity which is less than the first intensity during a probe portion. The system may also include one or more optical elements configured to direct the therapeutic portion and the probe portion into an eye of a patient and to collect reflected radiation from the eye of the patient. The reflected radiation may be indicative of dynamics of microbubbles in the cells of the eye of the patient.

Unless otherwise indicated herein, the materials described herein are not prior art to the claims in the present application and are not admitted to be prior art by inclusion in this section.
Therapeutic radiation may be administered to an eye of a patient to treat various conditions of the eye that may negatively affect vision. It may be difficult to accurately measure an exposure level of the eye to the therapeutic radiation, which can damage the eye at excess exposure levels.

Enhancing optical detection of micro bubbles by laser pulse expansion


An improved slab cart is disclosed for the transport of a slab including a slab of marble, granite, stone, glass, and heavy objects. A first frame assembly attaches to a first end of a slab and a second assembly attaches to a second end of a slab. The first and second frame assemblies are coupled to the slab in such a manner as to support the slab in an upright position. The first and second frame assemblies each have a pair of elongated frame members and wheels mounted thereto for further supporting the slab and allowing the slab to roll freely without damaging surfaces upon which the slab cart may roll. The slab cart of the present invention is further provided with clamps coupled to the frame assemblies for engaging the slab in clamping relation. A retaining pin couples the ends of each frame member of each frame assembly preventing the frame members from spreading when the clamps are engaged.

Transporting slabs of dense material presents particular challenges given the weight, size, and potential for breakage of hard material configured as a slab. A variety of devices are available to assist in handling and transporting large slabs of marble, granite, glass, or otherwise flat, hard, and heavy objects. A stone slab may be transported between cutting area, finishing area, staging area and worksite using devices such as a wheeled cart or like means. Unique problems arise however in handling stone slabs due to their sheer size and weight. The large and unwieldy nature of a typical slab gives rise to additional problems during maneuvers such as ascending inclines, negotiating corners and the like.
Stone slabs must be supported in an upright position during transport in order to prevent breakage and to allow a proper fit through restricted spaces such as doorways, narrow hallways, and the like. In addition, breakage is more likely when a slab is carried flat not only due to increased probability of contact with obstacles but because of the inherent weakness of a slab in the cross sectional direction. Although the upright position is most suitable for slab transport, the slightest tipping or urging in a lateral direction must be avoided. The slab's great weight will carry it over quickly during a fall.
Consequently, it is difficult to find suitable means for supporting a slab in an upright position during rolling and for maintaining upright stability when obstacles and the like are encountered. Upright instability can be attributed in part to the limitations posed on the placement of the center of gravity for the cart due to the position of the wheel axles for the cart. The placement of cart wheel axles in particular limit the placement of the slab to a position above the wheel axles. Placement of the wheel axles prevents the lowering of the center of gravity and limits the stability of the cart regardless of the size of the wheels.
Prior art stone carts exist that assist in dealing with the sheer weight of a stone slab. Maneuvering the stone slab over worksite obstacles while maintaining upright stability may still be problematic for prior art carts. Some prior art stone carts, in order to handle the sheer weight of the heaviest slab likely to be encountered are typically constructed with small diameter metal wheels. Metal wheels, impressed with the weight of a large slab, are a problem however when rolling across finished floors or carpets. Such hard wheels combined with slab weight often leave marks or cause actual physical damage. Other prior art carts are limited by their fixed physical configuration which arises in an effort to accommodate slabs of different sizes.
One such prior art device is disclosed in U.S. Pat. No. 3,580,601 issued to Miles. The disclosed skate device allows for the transport of large objects but has characteristic disadvantages associated with devices of this and like kind. Because of the fixed length of the skate, longer objects placed upon the skate contact the surface of an incline before the first wheel of the skate. Such a situation gives rise to the potential for damage to slab corners and may prevent successful negotiation of the incline all together.
Attempting to accommodate all object sizes is problematic however for a device such as that disclosed in Miles which purports to be a multi-purpose device. Since objects of many sizes must be accommodated, a single average length must be used for the skate construction. A skate optimized for longer objects would be inefficient for handling shorter objects and vice versa.
In addition to the disadvantages already mentioned, other disadvantages are known to those skilled in the art. For example, although rubber tires are disclosed in Miles as a replacement for aluminum or resin rollers, they are nevertheless disadvantageous in that they are of a solid rubber construction. Solid rubber tires are known in the art to present many of the same disadvantages as metal rollers in terms of leaving marks or causing actual physical damage as described above especially when more delicate surfaces are encountered.


An electronic device substrate includes an insulating plate base, an electronic circuit formed on one surface of the base, and a conductive film formed on the other surface of the base and having electrical conductivity. The electronic device substrate is completed through a manufacturing process including charge-removal movement in which removal of a charge of the base is combined with movement of the electronic device substrate. In the charge-removal movement, the electronic device substrate is moved with being supported by a substrate support part that has electrical conductivity and is grounded. The substrate support part abuts the conductive film during the charge-removal movement.

1. Technical Field
The present invention relates to an electronic device substrate, an electronic device, a method of manufacturing an electronic device, and an electronic apparatus.
2. Related Art
In order to enhance the yield and quality of products in fabrication of electronic device substrates, the improvement in manufacturing apparatuses for the electronic device substrates is being promoted. The electronic device substrates are typified by e.g. organic electro-luminescence (EL) panels, and particularly by active-matrix organic EL panels employing thin-film transistors (TFTs) as switching elements.
The manufacturing of the electronic device substrates involves the following problem: static electricity arising due to charging of the electronic device substrate in the manufacturing process thereof leads to breakdown of elements such as TFTs and absorption of dusts in the air to the substrate, which lowers the yield and quality of products. In recent years, the size of glass substrates, which are used as a base of the electronic device substrate, is being increased for lowering fabrication costs and improving the yield. This substrate size increase causes an increase of the total charging amount in the glass substrate, which is an insulator. Therefore, the above-described problem is getting more serious.
A technique is disclosed to prevent the charging of a glass substrate during the manufacturing process. In this technique, the glass substrate is supported by grounded conductive members during the transfer of the glass substrate. For example, JP-A-10-133229 discloses this technique.
However, the availability of the technique in this patent document is insufficient to prevent charging of recent large-size glass substrates.
In addition, in current electronic apparatuses, sufficient measures for achieving electro-magnetic compatibility (EMC) need to be ensured, in order to prevent the electronic apparatus from inhibiting the operation of other electronic apparatuses due to interference of electromagnetic waves and electric fields, and vice versa to prevent other electronic apparatuses from inhibiting the normal operation of the electronic apparatus. Therefore, the casing of some electronic devices is provided with a shield for blocking electromagnetic waves and electric fields. This shield needs to be coupled to the ground of an electronic circuit on the electronic device substrate. However, since a configuration for coupling the shield with the ground of the electronic circuit on the electronic device substrate needs to be formed, the number of parts and manufacturing steps increases, which problematically rises manufacturing costs.

Electronic device substrate, electronic device, method of manufacturing electronic device, and electronic apparatus


Nano- and micron sized metal oxide and mixed metal oxide particles are injected into a high temperature region wherein the temperature is between about 400° C. and less than 2000° C., and collected as particles or as coatings wherein a particulate nature is substantially maintained. The particles are altered in at least one of phase, morphology, composition, and particle size distribution, and may achieve further changes in these characteristics by coinjection of metal oxide precursor in liquid form.

1. Field of the Invention
The present invention is directed to modification of metal oxide particles by injection into a flame of moderate temperature by liquid feed flame spray techniques.
2. Background Art
Particles have been supplied into high temperature plasma or flames, i.e. above 2000° C., to melt or even vaporize the particles for use in preparing coatings. However, the art is silent regarding lower temperature processes whereby phase may be altered, for example a crystalline phase or an amorphous phase, or both, or whereby hollow or core/shell particle morphology may be created from particles in the micron range, and preferably those of nanometer size, while retaining their particulate nature.
There are numerous methods of preparing ultrafine, and nanosized oxide powders using chemical compounds as precursors. These methods are summarized in detail in "Mixed-metal Oxide Particles by Liquid Feed-flame Spray Pyrolysis of Oxide Precursors in Oxygenated Solvents," A. C. Sutorik, R. M. Laine, J. Marchal, T. Johns, T. Hinklin, WO 03/070640 A1 published Aug. 28, 2003, which is incorporated herein.
The literature also describes the injection of preformed particles, or occasionally their precursors, into a plasma or related high temperature flames, typically >2000° C., such that the particles are vaporized or fully melted to subsequently produce coatings such as thermal barrier coatings. In these instances, the particles are 10-50 μm diameter which are, in some instances, formed from nanosized particles in the range of 6-70 nm. The larger particles or precursors are typically injected off-axis into a plasma arc, and generally result in relatively smooth coatings, as the molten particles "splat" onto the substrate. A similar process has been used for many years to produce boules of alumina (sapphire, ruby).
Solution injection of precursors may also be used to prepare particles and/or coatings. In such processes, rapid evaporation of solvent initially forms more concentrated admixtures which then, under the high temperature pyrolysis conditions, further undergo such processes as breakup, precipitation, and/or gelation, followed by pyrolysis, sintering, and if the flame is hot enough, fusion. Often, the fused particles are much larger than the particles initially formed, as the result of forming agglomerates prior to fusion. The process is also useful for forming thermal barrier coatings. However, their particulate nature is substantially lost. Alumina, alumina/zirconia and also alumina/titania mixtures are used commonly for the formation of such thermal barrier coatings. In most instances, the alumina formed is the gamma phase with small amounts of alpha. For example, Trice et al., "Deformation Mechanisms in Compression-Loaded Stand-Alone Plasma-Sprayed Alumina Coatings," J. AM. CERAM. SOC. 83, p. 3057-64 (2000), obtain alumina systems wherein the alpha content is ≈10%.
It would be desirable to provide a process in which particles are obtained with morphologies and other characteristics which cannot be obtained by in situ formation of particles from liquid or gas phase precursors. It would be further desirable to uncouple the chemical makeup of such particles from that of their precursors. It would be further desirable to enable substrates to be coated with coatings wherein the particulate nature of the particles used in preparing the coating is retained.
Thus, in one aspect, the invention pertains to injection of nano-, ultrafine- and micron-sized ceramic oxide particles into low temperature (400-2000° C.) oxidizing, reducing or neutral flames individually, in combination with each other, or coinjected coincidentally or serially downstream, optionally also with chemical precursors, and as a result, their phases, particle sizes and size distributions, phase compositions and physical and chemical properties significantly modified by exposure to the flame and to the coinjected or serially injected materials. During the process, novel and unexpected particle morphologies and size distributions can be generated through the use of combinations of particles, or combinations of particles and precursors coinjected, or serially injected downstream from the initial liquid feed flame spray combustion unit. This process includes the coating of supports and substrates with combinations of metal oxides and metals for development of new catalysts, photonic materials, sensing materials, thermal barrier coatings, abrasion and corrosion resistant coatings, prosthetic ceramic materials, conducting materials, transparent ceramics, etc. In preferred aspects, the products may be α-alumina or combinations of α-alumina coated with other metal oxides or products of the reaction of γ- or α-alumina nanoparticles with coinjected or serially injected components including other metal oxide powders or precursors or combinations thereof; are large clay particles transformed to dense spherical or hollow spherical particles that can be coated with alumina or related hard ceramic nanopowders for applications ranging from novel abrasives to insulating packing materials for construction materials; metal oxide coatings on alumina, yttria, YAG, or titania, NiO or other transition, lanthanum or actinide or main group metal oxide such that the coatings can be modified to become catalytically active or electrically conducting, and may be transparent as well, for applications ranging from self-cleaning photocatalytic materials to fuel and fine chemical processing catalysts to antistatic and/or conducting coatings; and products wherein a glass, ceramic, metal or mixed phase material is placed such that the hot particles impinge on the heated surface and adhere to form coatings that are corrosion resistant, abrasion resistant, catalytically active, thermally robust, insulating, conducting or combinations thereof; while the particles remain substantially in particulate form, and are preferably either dense, porous, or exhibit a gradient from porous to dense or vice versa.

Liquid feed flame spray modification of nanoparticles

The Regents of the University of Michigan


A method of manufacturing a thin-walled polyurethane article includes dipping a shaped former into a coagulant solution and subsequently dipping the shaped former into an aqueous-phase polyurethane/plasticizer dispersion wherein the unplasticized polyurethane has a mean particle size of between about 0.5 .mu.m and 1.0 .mu.m and wherein the plasticizer causes the polyurethane particles to swell until they have a mean particle size of between about 1.5 .mu.m and 3.0 .mu.m. Articles so produced have a thickness of between 0.03 mm to 1.0 mm, a tensile strength of between 17 MPa and 60 Mpa and an elongation at break of greater than 650%.

Elastomeric thin-walled articles, such as gloves for surgical use, are generally manufactured from natural rubber, usually by dipping a glove former into a vessel containing natural rubber latex. However, problems have been encountered with natural rubber surgical gloves since small quantities of proteins may leach from the glove.
As a result, attempts have been made to manufacture surgical gloves from synthetic materials such as polyurethane. For example, U.S. Pat. No. 4,463,156 to McGary, Jr., describes, in Example 14, the manufacture of a mixed diol, 4,4'-diphenylmethane diisocyanate polyurethane. A 20% solids solution of the polyurethane was prepared and a glove produced by dipping a glove former into the suspension. However, such polyurethane suspensions tend to be fairly unstable during storage and therefore do not lend themselves to production processes.
European Patent Application No. 0413467 discloses polyurethane condoms which are manufactured by dipping a suitably shaped former into an organic solvent solution of a polyurethane. However, such processes contain undesirable solvents that give rise to increased costs and problems with waste products.
Another major problem associated with the use of elastomeric materials, such as polyurethane, is the presence of voids and microporosities that reduce elastomer strength and elongation. Elastomer, or polymer, strength and elongation depend on the concentration and intrinsic strength of the polymer and is a function of both the structure of the polymer and its molecular weight.
The absence of voids in protective coatings and for articles, such as condoms and gloves, is also essential to prevent the transmission of viruses and causing other injuries. Voids can develop where polymerization or coagulation of particles is interrupted by solid impurities that are not wetted by the curing elastomer, as is the case with the macromolecules forming latexes. Likewise, although the detailed microscopic mechanisms of systems undergoing phase transitions are not completely understood, especially near phase transitions where large numbers of particles act coherently, voids tend to develop in the interstitial spaces between relatively large elastomer molecules when articles are formed by the evaporation of liquids, such as solvents or carrier liquids. As a result, polymer particle size and size distribution are important and limiting characteristics affecting film formation.
The drying of polymer coatings is commonly characterized by four stages: ordering, deformation, coalescence and interdiffusion. Ordering occurs as water or other liquids evaporate and polymer particles approach each other to form a close-packed array. Deformation occurs when the particles subsequently deform to fill the interstitial space between them but remain physically separated by hydrophilic layers consisting of water and surfactant material. Coalescence occurs as the hydrophilic membranes begin to break up and the particles come into contact with one another. Finally, interdiffusion occurs when the polymer chains diffuse across particle boundaries. Interdiffusion leads to mechanical strength and the loss of all notice of the initial particles. However, the described drying mechanism previously precluded their use because the relatively large interstitial spaces between the particles trapped large amounts of liquids, compared to the amount of liquid in the smaller interstitial spaces between small particles. That resulted in poor drying of the polymer film and, thus, poor mechanical characteristics to the product. Prior art compositions exhibit less advantageous mechanical properties as particle size increases. In addition, the compositions tend to form undesirable agglomerations after a prolonged period of storage.
Sadowski et al. (J. S. Sadowski, B. Martin and D. D. Gerst, "Polyurethane Latexes for Coagulation Dipping," Elastomerics, August 1978, 17-20) recognized that particle size is, relatively, one of the most critical factors in the selection of aqueous-based dispersions. Sadowski et al. disclosed that polyurethane gloves may be made by the "Anode" process that dips a former into a coagulant bath and then dips the former into a polyurethane latex with a particle size between 0.06 to 0.3 .mu.m. With particle sizes above about 0.3 .mu.m, the dispersions become increasingly less suitable for the production of thin coatings because dispersions with a fairly high average particle size tend to settle out. In accordance with the prior art, it is therefore preferable to employ a dispersion having an average particle size of no more than 0.3 .mu.m.
To date, polyurethane gloves manufactured using Sadowski et al.'s method or any other coagulation dipping method have never been made commercially available. Thus, there has been a long felt want for a commercially viable process for the dispersion dipping of polyurethane articles and polyurethane gloves in particular.


A wire bending jig adapted for jewelry manufacture having one or more arrays of holes for receiving bending pins. The jig has means to hold the tare end of the wire stock, freeing the hands for the work of bending wire. The bending jig may be held in one hand, mounted to a work table, or mounted in tandem on a base for complex tool construction.

1. Field of Invention
This invention relates in general to wire bending tools and in particular to benders for fabrication of jewelry components comprising wire.
2. Description of Prior Art
In the prior art, products constructed of bent wire or rod are often made utilizing bending jigs with pins around which wire or rod material is bent into the shapes specific to the application.
Components for manufactured goods, including reinforcing rod for cast concrete, usually are required to be uniform in shape and the dimensions are determined by the use to which they are put. Thus, a custom made jig is an ideal tool for bending the feed stock for such components.
Such jigs and associated tools are easily and inexpensively fabricated to produce the infinite variety of products varying in size, shape, and material. Heavy bending jigs even for heavy rod stock such as reinforcing bar can easily be constructed without resorting to machine shop facilities by welding common pipe and plate. Light bending jigs are often merely nails driven into a sheet of plywood. Therefore, there is little incentive for the development of generalized adjustable bending or wire harness tooling.
Jewelry on the other hand, seldom has tight pre-determined dimensional requirement, but similar pieces used together should be similar enough to be pleasing to the user. A jig is an ideal tool to nearly identical parts or parts with minor artistic differences identifying the parts as hand made. For jewelry, the absence of a specific dimensional requirement permits the pins to be placed in a pattern with a discrete resolution such as is characteristic of a grid or array pattern.
The volume of similar parts made in a jewelry project is usually rather small and there usually are several sets of similar parts, sometimes in graduated sizes. A jig or set of jigs each having several fixed bending points can be used to fabricate a variety, but finite number, of shapes. Therefore, an adaptable jig proves useful to jewelry artisans and other craft producers.
U.S. Pat. No. 5,632,086, by Gary Helwig, is a typical fixed jig having 4 bending pins spaced for the construction of several wire sculptures. Helwig's company also catalogs fixed bending jigs with other patterns for construction of other wire jewelry shapes. Fixed jigs in the prior art do not have general means to retain the beginning end of the wire being bent, therefore, the end must be held by with a pair of pliers until the wire workpiece is bent sufficiently to tend not to move the loose starting end away from its initial position.
One patent shows an adjustable frame having bars with T slots to receive threaded bending pins adapted for use as a wire harnessing jig. Wire harnesses are large structures and there is very little load placed on the bending pins which have a primary function to hold the bundle of wires prior to tying with cord or tape. There is no significant stress applied by the action of bending the usually very flexible wires. This invention is not adaptable to small jig frames because of the size of the T slot holding bars. The wire harness jig requires tools to change and cannot be made usefully small enough to be hand-held.
Although various types of wire bending jigs have been disclosed in the prior art, and some have been designed for use with small diameter wire and the shapes particularly useful for wire jewelry and wire components such as springs and retainers, none have the flexibility of assembly to comprise a universal bending jig capable of re-configuration to make components meeting the specifications of end uses.

Wire bending jig for jewelry manufacture


A resistor element for determining a parameter, including a ceramic support, an electrically resistive body formed on the ceramic support, at least one lead wire electrically connected to the electrically resistive body, and an adhesive containing platinum for securing the lead wire(s) to the ceramic support. Each lead wire includes a wire rod having a lower thermal conductivity than platinum, and a covering layer which covers the wire rod and is formed of an alloy including platinum as a major component.

1. Field of the Invention
The present invention relates in general to a resistor element, and more particularly to a resistor element which utilizes temperature dependence of an electrical resistance of an electrically resistive body, and which may be suitably used as a thermal flowmeter for measuring an amount or a flow rate or velocity of a fluid flowing in an internal combustion engine, for example.
2. Discussion of the Prior Art
There are known resistor elements of the above type having a cylindrical shape or a planar shape. FIG. 1 shows an example of cylindrical resistor element, which includes a ceramic tube 2 formed of alumina, for example, and having an outside diameter of about 0.5 mm, and a platinum thin layer 8 which is formed on an outer surface of the tube 2 and suitably patterned so as to have a desired resistance value. A pair of electrical conductors or leads 4 in the form of platinum wires having a diameter of about 0.2 mm are inserted into the opposite end portions of the ceramic tube 2, and are secured thereto by respective masses of platinum paste 6 serving as adhesives. The platinum layer 8 and leads 4 are electrically connected to each other, through the adhesive masses 6 provided at the opposite end portions of the ceramic tube 2.
Where the platinum wires are used as the leads as in the known resistor element, however, the heat generated by the resistor element tends to escape through the leads, rather than being dissipated into a fluid to be measured as intended. Accordingly, the temperature of the resistor element cannot be responsive to the amount or flow rate of the measurement fluid, resulting in reduced detecting accuracy of the element and a prolonged time required to start its detecting operation.
To solve the above problem, the leads may be formed of a material, such as 40Ni-Fe alloy, which has a lower thermal conductivity than platinum. In this case, however, the resistor element suffers from poor adhesion between the leads and the adhesive masses prepared from the platinum paste. When tensile stresses are exerted on the leads during installation of the resistor element by welding, therefore, the leads are likely to be pulled out of the adhesive masses, giving rise to clearances or cracks and accordingly reduced contact between the leads and adhesive masses. Consequently, the resistor element greatly suffers from a change in its electrical resistance. Since various thermal stresses are applied to the resistance element during its use, causing clearances or cracks between the adhesive masses and leads, the resistor element in use also suffers from a change in its electrical resistance.
To improve the adhesion between the leads and the adhesive masses prepared from the platinum paste, and to prevent oxidization of the leads during manufacture of the resistor element, it is proposed to employ a lead which consists of a wire rod or core formed of 40Ni-Fe alloy, and a platinum layer formed on the outer surface of the wire rod. While the thus formed lead is less likely to be pulled out of the adhesives, the thermal conductivity of the lead as a whole is undesirably increased because of the platinum layer, causing the same problem as encountered when the lead is formed solely of platinum.

Resistor element having lead wire consisting of wire rod and covering alloy layer


The present invention describes a process for the production of natural truffle (Tuber ssp.) aromas using cultures of truffle mycelium and the use of at least one aroma precursor to induce the production by truffle mycelium of volatile compounds characteristic of the natural aroma of truffle fruiting bodies. This invention also includes truffle mycelium (Tuber ssp.) cultivated according to the process of the invention, aromatized products having the smell and the taste of natural truffle fruiting bodies and extracted from said truffle mycelium, as well as aromatized substrates containing the same aromatized products.

Truffles (Genus: Tuber; Family: Tuberacea; Order: Pezizales) are ascomycetes fungi which live in symbiosis (ectomycorrhizae) with oaks, beech, hazels, etc. Among the 60 species that exist, only a limited number of species are praised for their aroma and for their taste, including the black Périgord truffle (Tuber melanosporum), the White Piedmont truffle (Tuber magnatum); the summer truffle (Tuber asetivum), another black truffle (Tuber brumale) and the "small white Italian truffle" (Tuber borchii). The world production is in constant decline: about 1000 tons of truffles were produced at the beginning of the 19th century, but only 80 to 150 tons are produced nowadays.
For more than 50 years, humans have been planting trees which roots had been inoculated with truffles. Less than 5% of these trees produce truffles and this usually only after 5-10 years due to the poor understanding that human have of truffle biology.
Truffle aroma is made up of about 50 volatiles, which are hydrocarbons containing alcohol, ketone, aldehyde and ester functional groups and also sulfur atoms. Different truffle species have a distinct aroma from each other because they produce species specific volatile compounds. Some volatiles are also common to all truffle species; however they are produced by each species in specific quantities. Taken separately none of these volatile compounds smells like truffle fruiting bodies, however once the right compounds are mixed in the right proportions, the mixture reproduces the aroma of truffle fruiting bodies.
Nowadays truffle aromas can be obtained using truffle fruiting bodies and trapping their aroma into a solid substrate (i.e. rice, some cheeses or liver such as the French "foie gras") or a liquid substrate (oils, creams) by extraction or maceration. Another way to obtain black truffle aroma is to use synthetic truffle aromas basically composed of dimethylsulfide and 2-methylbutanal according to the French Patent FR 86 10871 A1 (Delmas, Institut National Polytechnique de Toulouse) or composed of dimethylsulfide and methylethylketone (also known as 2-butanone) according to the Italian Patent IT 1215936B (SENTOSA S. A. S MILANO).
The use of the synthetic compounds in specific proportions described in the French and Italian patents mentioned in the previous paragraph do not permit, according to the European legislation, to use the label "natural truffle aroma" for products that contain those synthetic mixtures. The invention described herewith specifically permits to obtain such a "natural aroma" of white or black truffle, since the aroma compounds are directly derived from truffle mycelium.
Additionally, since the creation of synthetic truffle aromas, international experts agree that synthetic truffle aromas does not have the complexity and nuances of natural truffle aromas, simply because synthetic aromas only contains a limited number of molecules (2 to 5 in total) compared to natural aromas that contains much more constituents (more than 20 volatiles). Furthermore the production costs of natural truffle aromas keeps on rising due to the decline observed in the worldwide production of truffle fruiting bodies (Fauconnet and Delher 1998; Hall and Yun 2001).
Furthermore the aroma analysis performed so far on the truffle mycelium of Tuber borchii (the "small white Italian truffle") showed that even though many aroma molecules are spontaneously produced by the mycelium, they do neither reproduce the smell nor the complexity of fresh truffles (Tirillini et al., 2000; Splivallo et al., 2007). Additionally the American company Truffle International which produces truffle mycelium in hydroponic cultures acknowledges that the taste and aroma of their products clearly differs from the one of truffle fruiting bodies, mostly due to a very low concentration of sulfur containing volatiles (Fields, 2007; see also the web site of the company <<Truffles International>> http://www.truffiesinternational.com/truffle_science.html).
It should be stressed that most culture media used so far to grow truffle mycelium contained low concentrations of amino acids (traces), simply because these culture media are themselves derived from plants (i.e. the potato extract "potato dextrose broth" used in Splivallo et al., <<Discrimination of truffle fruiting body versus mycelial aromas by stir bar sorptive extraction>>, Phytochemistry (Amsterdam) October 2007, Vol. 6668, No. 20, pp 2584-2598). Amino acids are as a matter of fact often used in microbiology to favor the growth of microorganisms. In the case of truffle mycelium, a low concentration of amino acids (traces) is however not sufficient to induce the production volatiles characteristic of the aroma of truffle fruiting bodies.
The patent JP 2005295858 also recommends using amino acids to favor nitrogen uptake by black truffle mycelium thus inducing its growth. The authors of the latter patent however admit that truffle mycelium obtained in such a way does not smell like truffle fruiting bodies, and even recommend drying the mycelium to facilitate its handling/marketability of their product (which surely results in the loss of any aroma compound).
In summary, the invention described in the present patent allows to induce the production of volatile compounds in a targeted manner and as a whole obtain a mixture of volatiles which are characteristic of the natural aroma of truffle fruiting bodies (sulfur containing volatiles and other key volatiles of truffle aroma).
Considering that synthetic truffle aroma is poorly accepted by consumers, and considering the very high prices reached by natural truffle aroma obtained from fruiting bodies, the present invention also offers a solution to the market by defining an alternative and cheaper process to obtain natural truffle aromas. The present invention also permits to reduce overharvesting of truffles in the wild, thus decreasing the ecological pressure on the fungus.

Production of natural truffle flavours from truffle mycelium