The invention relates to a plug-in connector, substantially consisting of an insulating body and at least one contact element which is mounted directly in the insulating body, wherein the insulating body directly forms the plug-in connector housing of the plug-in connector. The plug-in connector is of particularly simple construction and can therefore be manufactured quickly. In addition, the plug-in connector is of very robust design and suitable for industrial use, in particular in harsh environments.

The publication EP 0 945 929 A2 discloses a plug-in connector having a rectangular cross-section for use in an industrial environment. The plug-in connector demonstrates an insulating body in which the contact elements are arranged using insulation displacement connection technology. The individual conductors of a connected cable are arranged in one contact piece. As the contact piece and the insulating body are joined together, the individual conductors are contacted by the associated contact elements in an electrically conductive manner. The insulating body that is joined to the contact piece is surrounded by a metal plug-in connector casing.
The plug-in connector disclosed in EP 0 945 929 A2 has proven its worth. However, owing to its multiple component parts, it necessitates high production costs and assembly costs. In addition, the parts require a large amount of installation space in the plug-in connector casing and this makes the overall plug-in connector extremely large and as a consequence limits its field of application.
The publication U.S. Pat. No. 1,672,521 A discloses a plug-in connector having a casing that is manufactured from two parts that are screwed together. The two parts each have two receiving devices for respectively fixing a contact element.
The publication GB 1 537 061 A discloses a plug-in connector having a plug-in connector casing that is injection molded onto a cable. Contact elements that are likewise arranged in the plug-in connector casing are arranged on the individual conductors of the cable.
The publication EP 0 424 699 A2 discloses a casing feed-through having an insulating body which has a cable passing through it.
The publication US 2004/0235321 A1 discloses two plug-in connectors which can be plugged together and mutually matching contact elements are held in the casing of each plug-in connector.
The publication DE 10 2015 113 786 A1 discloses a plug-in connector which has a plug-in connector casing having a locking bracket, an insulating body which is arranged in the plug-in connector casing and an electrical contact which is arranged in the insulating body.
There is generally a need in the industrial environment to make the best possible use of the available space, i.e. to accommodate as many technical components as possible in the limited space. A compact as possible installation space is accordingly required for such industrial plug-in connectors. A wide functionality spectrum is required simultaneously. The plug-in connectors must fulfill the most varied tasks.
During the priority application regarding the current application, the German Patent and Trademark Office has researched the following prior art: U.S. Pat. No. 1,672,521 A, GB 1 537 061 A, EP 0 424 699 A2, DE 10 2015 113 786 A1, US 2004/0235321 A1.


The ink set of this invention comprises at least two inks, one of which contains a pH sensitive polymer and pigment colorant with dispersant. A second ink is provided which comprises incompatible inorganic or organic salts or has an appropriate pH. The polymer precipitates onto a medium upon contact with the second ink, thereby providing improved bleed control.

The present invention relates to ink-jet inks employed in ink-jet printing. In particular, this invention relates to an ink system that utilizes the addition of specific polymers to conventional, non-self dispersing pigment-based ink. These polymers reduce, and in some cases even eliminate, color bleed problems typically associated with ink-jet printing.
Ink-jet printers offer a low cost, high quality, and comparatively noise-free option to other types of printers commonly used with computers. Such printers employ a resistor a element in a chamber provided with an egress for ink to enter from a plenum. The plenum is connected to a reservoir for storing the ink. A plurality of such resistor elements are arranged in a particular pattern, called a primitive, in a printhead. Each resistor element is associated with a nozzle in a nozzle plate, through which ink is expelled toward a print medium. The entire assembly of printhead and reservoir comprise an ink-jet pen.
In operation, each resistor element is connected via a conductive trace to a microprocessor, where current-carrying signals cause one or more selected elements to heat up. The heating creates a bubble of ink in the chamber, which expels ink through the nozzle toward the print medium. In this way, firing of a plurality of such resistor elements in a particular order in a given primitive forms alphanumeric characters, performs area-fill, and provides other print capabilities on the medium.
When some ink-jet inks are printed adjacent to each other a condition called xe2x80x9cbleedxe2x80x9d can appear. Bleed occurs as colors mix both on the surface of the paper being printed on and in the paper. The terms xe2x80x9cbleedxe2x80x9d, as used herein, are defined as follows: when inks of two different colors are printed next to each other, it is desired that the border between the two colors be clean and free from the invasion of one color into the other. When one color does invade into the other, the border between the two colors becomes ragged, and this is called bleed. This is in contradistinction to uses of the term xe2x80x9cbleedxe2x80x9d in the prior art, which often defines xe2x80x9cbleedxe2x80x9d in the context of ink of a single color following the fibers of the paper.
Prior solutions to bleed have largely involved the use of heated platens or other heat sources and/or special paper. Heated platens add cost to the printer. Special paper limits the user to a single paper, which is of a higher cost than a plain paper. Another way to reduce bleed involves increasing the penetration rate of the ink into the paper. However, increasing the penetration rate reduces the edge acuity (lowers the print quality of the ink). Nevertheless, this method is acceptable for printing color ink because of the lesser importance of color text quality. However, print quality is important for black ink. And hence, alternate bleed control mechanisms are needed.
U.S. Pat. No. 5,428,383 teaches a method to control bleed in multicolor ink-jet printing involving the use of multi-valent metal salts as precipitation agents in a first ink composition. The precipitation agent is designed to react with the coloring agent in a second ink composition.
A solution to the specific problem of black to yellow color bleed is disclosed in U.S. Pat. No. 5,198,023 wherein multivalent cations such as calcium chloride and magnesium chloride are added at concentrations ranging from about 1 to about 10 wt % to yellow cationic inks to prevent bleed between yellow and black inks. However, it has been determined that the addition of large amounts of multivalent cations to thermal ink-jet ink compositions may induce precipitation of dye salts, requiring further adjustments in the ink composition. U.S. Pat. No. 5,518,534 teaches the use of a first ink having a pigment dispersion and the second ink containing a salt of an organic acid or mineral acid wherein said salt reacts with said first ink to alleviate bleed between the inks. However, in this case, the pigment requires the presence of a dispersing agent, and both inks must have the same ionic character.
A method to control bleed is also disclosed by U.S. Pat. No. 5,730,790. The ink-jet ink is formulated to comprise at least one dye-based ink composition and at least one pigment-based ink. The dye-base ink also contains a cationic surfactant, and the pigment-base ink contains a negatively charged dispersant.
Another method of reducing bleed between ink-jet inks involves the use of pH-sensitive dyes as disclosed in U.S. Pat. No. 5,181,045. It discloses an ink having a pH-sensitive dye to prevent bleeding to an adjacent ink having an appropriate pH. Migration of the ink having the pH-sensitive dye is prevented by rendering the dye insoluble on the page by contact with the pH of the adjacent ink. This method requires a pH differential of about 4 or 5 units to completely control bleed. Accordingly, a pH not exceeding 4 would be required to effectively eliminate bleed from a pH-sensitive ink having a typical pH of about 8.
U.S. Pat. No. 5,679,143 builds upon the ""045 case referenced above, but an organic acid component is added to the so-called target ink-jet ink composition, as opposed to the pH-sensitive ink composition. The organic acid component reduces the pH differential required to control bleed to about 3 units or less.
While each of the above has produced varying degrees of success, a need still remains for pigment-based (non self-dispersing) ink compositions for use in ink-jet printing which do not evidence bleed, as defined herein, when printed on plain papers, and yet which posses relatively long shelf life and other desirable properties of such inks.
In accordance with the invention, an ink set is provided in which certain pigment-based inks contain polymers which become insoluble under either specific and well defined pH conditions or when contacted with incompatible ionic substances. By forcing the polymers present to become insoluble on the page, migration of the colorant is inhibited, thereby helping to reduce bleed between different colors. Rendering the polymers insoluble is achieved by making the polymer come out of solution or to precipitate; this is done by contacting the polymer with another ink having an appropriate pH or one which contains ions that are incompatible with the polymers, or both.
The specific polymers disclosed herein are added to pigmented inks that are stabilized by a dispersant. Thus, in systems in which a dispersant yields a very stable dispersant but is not useful in the control of bleed, the specific polymers herein can be added in small quantities to enhance bleed performance. A further advantage of adding these specific polymers is that the concentration of acids and/or incompatible ions in the color inks can be significantly reduced. Lowered concentrations of the acids and ions in the color inks means that the ink will have better stability, better compatibility with pen materials, and will fire more reliably from pens. Thus, the combination of a dispersed pigment along with these bleed-reducing polymers provide for a very stable pigmented ink composition which have components which precipitate out of solution without adversely affecting the overall pigment""s stability.
It has long been known that certain colorant classes, especially pigments, are insoluble or become insoluble under specific and well defined pH conditions or in the presence of incompatible ions. Thus, the use of pigments in ink formulations has been limited to either 1) pigments in conjunction with dispersants or 2) self-dispersing pigments. Moreover, the dispersant must have two attributes. First, it must be able to stably disperse the pigment in the aqueous ink composition. Second, it is desirable for the dispersant to provide some measure of bleed control, or at the least not promote bleed. Industry has been challenged in formulating ink with the above limitations. However, now with this invention, a specific group of polymers has been found which precipitate under certain pH conditions or in the presence of certain ions, but do not affect the dispersability of the pigment. These polymers allow for the use of a broader class of materials, particularly dispersants that have not been previously associated with good bleed control. Additionally, since the class of non-self dispersing pigments far outnumbers the class of self-dispersing pigments, the formulator has an increased choice of available pigments as well. Use of these specific polymers thus allows for formulation flexibility because these polymers do not interfere with the dispersion or water-solubility of the pigment. This new class of polymers can be utilized for dispersion without concern of their ability to affect bleed. By utilizing a separate dispersant to disperse the pigment, the polymers of this invention can be designed to be pH and ion/or sensitive yet have little or no dispersing ability.
An advantage of the polymer""s ion sensitivity is the ability to formulate an ink composition with reduced levels of reactive ions. Since these polymers precipitate in the presence of low levels of ions, the secondary ink, which contains the ions, can be formulated to have much lower levels; thus, adding to the flexibility of the formulation and the stability of the ink.
Without subscribing to any particular theory, the Applicants believe that by forcing a polymer contained in an ink to become insoluble on the page, then migration of the colorant in the ink will be inhibited, thereby helping to reduce bleed between the inks. The xe2x80x9cforcexe2x80x9d used to make the polymer come out of solution or to precipitate is to contact the polymer containing ink with another ink having an appropriate pH or containing incompatible ions.
Polymers
The polymers of this invention can be random or block copolymers and contains at least one of each of the following: 1) basic amine monomer, 2) acid monomer, and 3) hydrophobic monomer. The polymers are selected to precipitate with a change of pH or in the presence of certain ions or both. In general, polymers which precipitate with a change from higher to lower pH will comprise monomers containing an acidic group and a hydrophobic group; polymers which precipitate with a change from lower to high pH will comprise monomers containing amine functionality and hydrophobic moieties. The structure for the polymers of this invention is:
wherein R1 are independently selected from H or a C1-C18 substituted or unsubstituted, branched or unbranched, alkyl, aromatic, or cyclic chain and may contain halogen, ester, ether, amine or amide functionalities, and is preferably H, CH3, a halogen or a halogenated methyl group; and R2 is a group containing either a carboxylic acid group having a pKa of from about 5.0 to about 7.5, or a primary, secondary, or tertiary amine functionality. R3 is a C1-C18 substituted or unsubstituted, branched or unbranched, alkyl, aromatic, or cyclic chain, which may contain ester, ether, amine or amide functionalities. Examples of monomers of type X that contain carboxylic acids that are useful in the invention include, but are not limited to; acrylic acid, methacrylic acid, crontonic acid, 2-trifluoromethylacrylic acid and 2-bromoacrylic acid. Typically, polymers containing acidic R2 monomers will be present in the ink as acid salts of Na, K, Li, triethanolamine, 2-amino-2-methyl-1propanol and the like. Examples of monomers of type X that contain primary, secondary, and tertiary amines that are useful in the invention include, but are not limited to; 2-(diethylamino)ethyl acrylate, 2-(dimethylamino)ethyl acrylate, 3-(dimethylamino)propyl acrylate, butylaminoethyl methacrylate, 2-aminoethyl methacrylate and N-[3-(dimethylamino)propyl]acrylamide. Typically, polymers containing primary secondary, and/or tertiary amine R2 monomers alone will be present in the ink as salts of Cl, Br, I, sulfate, nitrate, and the like. Hydrophobic monomers of type Y that are useful in the invention include, but are not limited to; methyl and ethyl esters of acrylic and methacrylic acids, ethyl-2-(bromomethyl) acrylate, propyl acrylates and methacrylates, butyl a acrylates and methacrylates, isoamyl acrylate, hexyl acrylates and methacrylates, cyclohexyl acrylates and methacrylates and their alkyl derivatives, ethylhexyl acrylates and methacrylates, trimethylhexyl acrylate, isooctyl acrylate, isodecyl acrylate, dodecyl acrylate, tridecyl methacrylate, octadecyl acrylate, isobornyl acrylate and methacrylate, phenyl methacrylate, benzyl methacrylate, 2-butoxyethyl acrylate and methacrylate, 2-ethoxyethyl acrylate, neopentyl glycol acrylate benzoate, ethylene glycol phenyl ether acrylate, hydroxybutyl acrylate, alkyl esters of crotonic acid, N,N-dimethylacrylamide, N-isopropylacrylamide and methacrylamide, N-octylacrylamide, N-(butoxymethyl)acrylamide, N-(isobutoxymethyl)acrylamide, methyl-2-acrylamido-2-methoxyacetate, vinyl acetate, vinyl neodecanoate, cyclohexyl vinyl ether, 2-ethylhexyl vinyl ether and styrene. Polymers of this invention may contain more than one X-type or Y-type monomer.
Polymers that have acidic groups, such as carboxylate groups, are pH sensitive. These carboxylated, or otherwise acidified, polymers will either be in solution or precipitate based on their pH-dependant solubility. As the pH is lowered and the carboxylate groups become protonated, the solubility of the polymer decreases. At some point, the polymer will begin to become unstable and will effectively drop out of solution. Typical polymers for use herein include those having at least one and preferably multiple carboxyl groups, which commonly consist of acrylic monomers and polymers known in the art. Hydrophobic moieties are also required to aid in the precipitation of the polymer and induce flocculation of the pigment in an aqueous based ink. When the polymer carries a net anionic charge, the pigment must also carry a net anionic or nonionic charge.
The average molecular weight of the polymers of this invention ranges from about 1,000 to about 20,000, preferably from about 1,000 to about 12,000; more preferably from about 3,000 to about 10,000. The above monomers are provided in sufficient amounts to provide a polymer that will be stable when solubilized in water at the appropriate pH, yet will effectively precipitate and flocculate the pigment upon the change in pH or contact with the appropriate ions. Thus, polymers may be selected which comprise other monomers as long as an effective amount of the above monomers comprise part of the polymer chain.
In a preferred embodiment, R2 is a carboxylic acid moiety, thus having the structure:
wherein R1 are independently selected from H or a C1-C18 substituted or unsubstituted, branched or unbranched, alkyl, aromatic, or cyclic chain and may contain ester, ether, amine or amide functionalities, and is preferably H, CH3, a halogen or a halogenated methyl group; and n is from 0 to 15, preferably 0 to about 3, so as long as the group has pKa of from about 5.0 to about 7.5. R3 is a C1-C18 substituted or unsubstituted, branched or unbranched, alkyl, aromatic, or cyclic chain, which may contain ester, ether, amine or amide functionalities.
The acidity, measured by the acid number, of these polymers is in the range of 55-400 mg KOH/g of polymer; preferably from 80-350 mg KOH/g of polymer; more preferably from 80-200 mg KOH/g of polymer. When the polymers have X-type monomers without acidic groups and the R2 groups contain primary, secondary, and/or tertiary amine functionality, the amount of basic nitrogen in the polymer, measured as the meq of basic nitrogen per gram, ranges from between about 1 to about 7 meq/g, preferably about 1.5 to about 6.2 meq/g and even more preferably between about 1.5 to about 3.5 meq/g.
The following examples of polymers that are useful in this invention are not intended to limit the scope of the invention. Monomer ratios are given in weight percent. Molecular weights conform to the ranges given above. Examples; a) 8:92 acrylic acid:butyl acrylate, acid number 62 mg KOH/g; b) 10:90 methacrylic acid:butyl acrylate, acid number 65 mg KOH/g; c) 12:88 acrylic acid:ethyl acrylate, acid number 93 mg KOH/g; d) 14:86 methacrylic acid:ethyl acrylate, acid number 91 mg KOH/g; e) 16:60:24 acrylic acid:methyl methacrylate:hexyl acrylate, acid number 125 mg KOH/g; f) 16:5:15:64 acrylic acid:butylaminoethyl methacrylate:octylacrylamide:methylmethacrylate, acid number 125 mg KOH/g; g) 19:40:41 methacrylic acid:ethyl acrylate:methyl methacrylate, acid number 124 mg KOH/g; h) 30:30:30 methacrylic acid:methyl methacrylate:benzyl methacrylate, acid number 195 mg KOH/g; and i) 44:56 acrylic acid:ethyl acrylate, acid number 325 mg KOH/g. Other combinations could also be made. Some modifications could be made by those skilled in the art and still be within the spirit of the invention.
The use of pH sensitive polymers should not be confused with the use of pH changes on paper, which lead to improved waterfastness. First, waterfastness issues involve the ability of the ink to resist smearing when water is dripped across a printed line of ink, while bleed resistance is the ability of the ink to resist mixing of one color with another when both are printed in close succession. Having solved one problem does not imply a solution to the other.
Solving waterfastness in other systems has involved the use of a single ink. This is in contrast to the present invention in which a second ink is used to bring about the desired effect, i.e., reduction of bleed.
In addition, the present invention involves what is essentially a border effect, i.e., the drastic pH conditions of the two inks in question or the presence of incompatible ions in one of the inks bring about the desired effect at the border of the two inks. This differs with the mode in which other dye-based inks achieve waterfastness, i.e., an entire dot of black ink is subjected to paper which lowers the pH slightly and brings about insolubility (and thus waterfastness); see, e.g., U.S. Pat. No. 4,963,189.
Finally, it should be mentioned that using a second ink with a pH of, for example, 4 will have a much greater effect on the solubility of the pH-sensitive polymer than will any pH change caused by the paper. Paper-induced pH changes in the ink are small compared to contact with a fluid that is buffered at a pH of 4. Thus, while it is thought that the pH of the paper itself contributes to an improvement of waterfastness, in the present application, a second ink, having a pH low enough to bring about insolubility of polymers in the first ink or the presence of specific polymer-incompatible ions, is used to bring about the desired effect, i.e., bleed reduction.
The method of the invention eliminates the requirement of a heater or heated platen in order to reduce bleed from an ink of one color into an ink of another color, and the need for special paper to control bleed between inks that otherwise would bleed on plain types of paper.
While the specific example given is directed to the use of an ink having a lower pH than the first ink, it is also possible to employ an ink having a higher pH than the initial ink. In this case, the pH-sensitive ink would have the property that it precipitates as the pH is increased. For example, if the polymer is soluble at a low pH by carrying a positive charge through protonation of an amine group on the polymer, it is possible to precipitate the polymer by contacting it with a second ink that is buffered at a high pH causing deprotonation of the polymer. This system would work in conjunction with pigments that are either dispersed by dispersants containing nonionic or with a cationic charged moieties.
The effect on bleed may be seen at a pH difference of about 1 to 3 units. Further and near complete control of bleed results when the pH difference is further increased, to about 4 to 5 units. However, these values do not preclude the use of a polymer which is more sensitive to pH than those disclosed herein; with more sensitive pH-polymers, near complete control of bleed could result with only a small difference in PH, considerably less than 4 units.
Multivalent Salts
In one embodiment herein, the polymers of this invention interact with incompatible multi-valent (inorganic or organic) salts in the second ink. These salts must be soluble in the ink in the concentration employed. Suitably-employed cations for the multi-valent salt include alkaline earth metals of group 2A of the periodic table (e.g., magnesium and calcium); the transition metals of group 3B of the periodic table (e.g., lanthanum); cations from group 3A of the periodic table (e.g., aluminum); and lanthanides (e.g., neodymium). Preferably, calcium and magnesium are employed as cations in the practice of this invention. Suitably employed anions associated with calcium or magnesium include nitrate, chloride, acetate, benzoate, formate, and thiocynate. Salts preferably employed in this invention are nitrate, chloride, and acetate salts of calcium and magnesium. If used, the salt should be present in the second ink in an amount ranging from about 1% to about 10%, preferably from about 1.5% to about 7%, more preferably from about 2% to about 6% by weight of the ink.
Organic Acid
Examples of organic acids which may be included in the second ink to aid in the pH and buffering capabilities of the second ink include, but are not limited to, mono-, di-, and polyfunctional organic acids. In general, it is contemplated that any soluble organic acid having a pKa equal to or less than that of the pH-sensitive polymer of concern may be suitably employed. Preferably, one of the following classes of organic acids is employed: polyacrylic, acetic, glycolic, malonic, malic, maleic, ascorbic, succinic, glutaric, fumaric, citric, tartaric, lactic, sulfonic, and ortho-phosphoric acid, derivatives thereof, and mixtures thereof. If used, the organic acid should be present in the second ink in an amount ranging from about 1% to about 10%, preferably from about 2% to about 7%, more preferably from about 3% to about 6% by weight of the ink.
Pigments/Dispersants
A wide variety of organic and inorganic pigments, either alone or in combination, may be benefited in the practice of this invention, since it is contemplated that any pigments or combination thereof may be benefited in the practice of this invention. The term xe2x80x9cpigmentxe2x80x9d as used herein mean a water insoluble colorant. In practice, pigment particles are deagglomerated or dispersed in aqueous media to achieve greater uniformity in print quality of the ink. Any means for dispersing the pigment particles that is compatible with the remaining ink components may be employed in the practice of this invention. Examples of suitable dispersing means include hydrophilic pigment dispersing agents. Any hydrophilic dispersing agent that is compatible with the pigment may be employed in the practice of this invention. Examples of classes of polymeric dispersing agents commonly used to disperse pigment particles in aqueous media include random, block, and branched-type polymers. The polymer may be anionic, cationic, or nonionic in nature.
It is contemplated that a commercially available concentrated aqueous pigment dispersion is employed in the practice of this invention. Examples of such pigments dispersions include Hostafine Yellow and Hostafine Green, Fuji BBL Red and Fuji BBL Magentas.
The pigment particle size is an important consideration in ink-jet printing, since the pigment particles must be sufficiently small to permit free flow of the ink through the ink jet printing devices. For example, the ejecting nozzles of thermal inkjet office printers typically have diameters on the order of about 10 to 60 micrometers. The pigment particle size is also important in considerations of stability and color strength. Given these considerations, the range of useful particle size is about 0.005 to 15 micrometers. Preferably, the pigment particle size should range from about 0.005 to about 1 micrometer.
Illustrative examples of suitable pigments that are identified with respect to the Color Index include but are not limited to: pigments black 1, 7, 11, and 31; pigments blue 1,9,14, 15, 16, 27, 28, 29, 36, 60, and 61; pigments brown 24, 29, and 31; and pigments green 1, 2, 7, 36, and 50; pigments orange 5, 13, 16, 34, 36, 43, 46, 67, and 69; and pigments red 2, 3, 4, 5, 78, 17, 19, 22, 23, 31, 38, 48, 49, 2, 57, 63, 81, 88, 100, 101, 104, 112, 122, 146, 149, 170, and 179; pigments violet 2, 3, 9, 19, 23, and 29; and pigments yellow 1, 3, 12, 13, 14, 17, 34, 65, 74, 83, and 97.
All concentrations herein are in weight percent, unless otherwise indicated. The purity of all components is that employed in normal commercial practice for ink-jet inks. All references are hereby incorporated by reference.
Ink-jet Ink Vehiclexe2x80x94The ink compositions of this invention comprise the pigment, dispersant, a bleed controlling polymer(s), and the ink vehicle. For a discussion of inks and their properties, see The Printing Manual, 5th ed. Leach et al. (Chapman and Hall, 1993). See also U.S. Pat. Nos. 2,833,736; 3,607,813; 4,104,061; 4,770,706; and 5,026,755.
A typical formulation for an ink useful in the practice of the invention includes the pigment colorant (about 0.001% to 10 wt %), a dispersant (about 0.001% to 10%), one or more cosolvents (0.01 to about 50 wt %), one or more water-soluble surfactants/amphiphiles (0 to about 40, preferably about 0.1 to about 5 wt %), one or more high molecular weight colloids (0 to about 3 wt %), and water (balance). Of course, one or more of the inks in the ink-set will contain the bleed controlling polymer(s), present in a amount of from about 0.1 to about 10 % by wt of the ink composition, preferably from 0.1 to about 3%.
One or more cosolvents may be added to the vehicle in the formulation of the ink. Classes of cosolvents employed in the practice of this invention include, but are not limited to, aliphatic alcohols, aromatic alcohols, diols, glycol ethers, poly(glycol) ethers, caprolactams, lactones, formamides, acetamides, and long chain alcohols. Examples of compounds employed in the practice of this invention include, but are not limited to, primary aliphatic alcohols of 30 carbons or less, primary aromatic alcohols of 30 carbons or less, secondary aliphatic alcohols of 30 carbons or less, secondary aromatic alcohols of 30 carbons or less, 1,2-alcohols of 30 carbons or less, 1,3-alcohols of 30 carbons or less, 1,5-alcohols of 30 carbons or less, ethylene glycol alkyl ethers, propylene glycol alkyl ethers, poly(ethylene glycol) alkyl ethers, higher homologues of poly(ethylene glycol) alkyl ethers, poly(propylene glycol) alkyl ethers, higher homologues of poly(propylene glycol) alkyl ethers, N-alkyl caprolactams, unsubstituted caprolactams, substituted formamides, unsubstituted formamides, substituted acetamides, and unsubstituted acetamides. Specific examples of cosolvents that are preferably employed in the practice of this invention include, but are not limited to, 1,5-pentanediol, 2-pyrrolidone, 2-ethyl-2-hydroxymethyl-1,3-propanediol, diethylene glycol, 3-methoxybutanol, and 1,3-dimethyl-2-imidazolidinone. The cosolvent concentration may range from about 0.01 to about 50 wt %, with about 0.1 to 20 wt % being preferred.
Water-soluble surfactants may be employed in the formulation of the vehicle of the ink. These surfactants are added as free components to the ink formulation and are not otherwise associated or intended to become part of the polymers described herein. For convenience, examples of surfactants are divided into two categories: (1) non-ionic and amphoteric and (2) ionic. The former class includes: TERGITOLs, which are alkyl polyethylene oxides available from Union Carbide; TRITONs, which are alkyl phenyl polyethylene oxide surfactants available from Rohm and Haas Co.; BRIJs; PLURONICs (polyethylene oxide block copolymers); and SURFYNOLs (acetylenic polyethylene oxides available from Air Products); POE (polyethylene oxide) esters; POE diesters; POE amines; POE amides; and dimethicone copolyols. Amphoteric surfactants such as substituted amine oxides are useful in the practice of this invention. Cationic surfactants such as protonated POE amines may also be used. U.S. Pat. No. 5,106,416, discloses more fully most of the surfactants listed above. The non-ionic amphiphiles/surfactants are more preferred than the ionic surfactants. Specific examples of amphiphiles/surfactants that are preferably employed in the practice of this invention include iso-hexadecyl ethylene oxide 20, SURFYNOL CT-111, TERGITOL 15-S-7, and amine oxides, such as N,N-dimethyl-N-dodecyl amine oxide, N,N-dimethyl-N-tetradecyl amine oxide, N,N-dimethyl-N-hexadecyl amine oxide, N,N-dimethyl-N-octadecyl amine oxide, N,N-dimethyl-N-(Z-9-octadecenyl)-N-amine oxide. The concentration of the amphiphile/surfactants may range from 0 to 40 wt %, preferably from about 0.1% to 3 wt %.
To further improve optical density, between 0 and about 3 wt % of a high molecular weight colloid derived from natural or synthetic sources may optionally be added to the ink formulation. Addition of a high molecular weight colloid improves print quality. Example of high molecular weight colloids employed in the practice of this invention include alginates, mannuronic acid, carageenan, guar gum, xanthan gum, dextran, chitin, chitosan, carboxymethylcellulose, nitromethylcellulose, and all derivatives thereof. These colloids are disclosed in U.S. Pat. No. 5,133,803, xe2x80x9cHigh Molecular Weight Colloids for Bleed Control.xe2x80x9d The preferred concentration of the high molecular weight component colloid in the inks of this invention is from about 0.1% to about 0.75 wt %.
Consistent with the requirements for this invention, various types of additives may be employed in the ink to optimize the properties of the ink composition for specific applications. For example, as is well-known to those skilled in the art, biocides may be used in the ink composition to inhibit growth of microorganisms. Preferred examples of biocides include Urarcide(trademark) and Proxel(trademark), and NuoCept(trademark). Sequestering agents such as EDTA may be included to eliminate deleterious effects of heavy metal impurities, and buffer solutions may be used to control the pH of the ink. Other known additives such as viscosity modifiers and other acrylic or non-acrylic polymers may be added to improve various properties of the ink compositions as desired.
The inks are formulated by combining the various components of the vehicle and mixing them with the colorants and polymers disclosed herein. The viscosity of the final ink composition is from about 0.8 to about 8 cPs, preferably from about 0.9 to about 4 cPs.
A method of ink-jet printing is also disclosed herein. The inks of this invention may be used in any conventional ink-jet or bubble-jet or piezoelectric printer. Preferably the inks are used in thermal ink-jet printers. The ink is typically charged into a printer cartridge and printed on any medium. Examples of suitable media for printing includes paper, textiles, wood, and plastic.

Black to color bleed control using specific polymers in ink-jet printing inks containing pigmented inks requiring dispersants


A Fingerprint sensing device and a recognition system having a row/column array of sense elements which are coupled to a drive circuit and a sense circuit by sets of row and column conductors, respectively. The sense elements are actively addressable by the drive circuit. Each sense element contains a sense electrode and a switching device (e.g., a TFT) for active addressing of that sense electrode. The sense electrodes of the sense elements are covered by insulating material adapted for receiving, directly thereon or on respective conductive pads overlying the sense electrodes, a finger. Capacitances resulting from individual finger surface portions in combination with sense electrodes are sensed by the sense circuit by applying a potential to the sense electrodes and measuring charging characteristics. In the fingerprint recognition system, an output from the sensing circuit is analyzed and characteristical data is compared with stored characteristical data for identification and verification purposes.

This invention relates to fingerprint recognition systems and particularly fingerprint sensing devices for use in such systems.
Fingerprint recognition has been suggested for many applications, ranging from high security uses such as access control for buildings, computers or the like to low security uses such as replacements for conventional locks and keys. The main advantages of such systems are that they are easy and convenient to use, avoid the need for keys, personal identification numbers and the like, and should be less susceptible to fraudulent use. The sensing device is an important part of the system and the quality of the representation of the fingerprint that the device picks up will affect recognition capability and the amount of preprocessing required for verification.
Conventional forms of fingerprint sensing devices rely on optical detection methods. A simple optical sensing method can be open to fraudulent use by presenting a photographic image of a fingerprint. A more secure and common approach is to use a glass prism with frustrated total internal reflection. Light is directed through one face, reflected at a second face and passes out at the third face. A finger is placed on the second face and at the points where the finger is in contact with the glass, i.e. at the ridges of the fingerprint, reflection no longer takes place. Light continues to be reflected at regions where troughs of the fingerprint pattern are present. Light output from the third face is picked up by an image sensor. A binary image, in which those parts of the fingertip in contact with the glass show as black and the rest as white, can therefore be obtained. Such an optical sensing device has disadvantages however. For example, the device is comparatively bulky. Also it is essential that the contact surface be maintained clean and free of dirt or grease. Moreover, problems can occur because some people have drier fingers than others and because most people's fingers become drier in cold weather. A dry finger actually touches the glass at many fewer points than a moist finger with the result that the lines of the fingerprint appear as rows of small dots so that more image processing becomes necessary.
An alternative kind of fingerprint sensor was proposed in U.S. Pat. No. 4,353,056 which uses a capacitive sensing approach. The described sensor has a two dimensional, row and columm, array of capacitors, each comprising a pair of spaced electrodes, carried in a sensing member and covered by an insulating film. The sensors rely upon deformation to the sensing member caused by a finger being placed thereon so as to vary locally the spacing between capacitor electrodes, according to the ridge/trough pattern of the fingerprint, and hence, the capacitance of the capacitors. In one arrangement, the capacitors of each column are connected in series with the columns of capacitors connected in parallel and a voltage is applied across the columns. In another arrangement, a voltage is applied to each individual capacitor in the array. Sensing in the respective two arrangements is accomplished by detecting the change of voltage distribution in the series connected capacitors or by measuring the voltage values of the individual capacitances resulting from local deformation. To achieve this, an individual connection is required from the detection circuit to each capacitor.
While the described sensor may not suffer form the problems associated with the kind of sensor employing an optical sensing technique, it suffers from its own problems. For example, because the sensor relies in operation on deformation and requires the use of resilient materials, problems with durability and reliability may be experienced. Moreover, the need to provide a respective connection to each individual capacitor in the array means that a very large number of connecting lines is necessary. This creates difficulties, both in the fabrication of the sensing member and its interconnection with the detection circuit. In practice the large number of connections would likely also cause operating difficulties due to stray capacitances.

Fingerprint sensing device and recognition system having predetermined electrode activation


A method and to a sensor for determining the distance of sound generating targets, preferably wheeled or track-laying vehicles, from acoustic signals which are subjected to a Fourier transformation. In order to determine the target distance easily and reliably, it is provided that the acoustic signals received by an acoustic sensor at two successive points in time from a target that is at a distance r.sub.1 and r.sub.2, respectively, from the acoustic sensor are employed, after the Fourier transformation, for an evaluation of the phase difference in the sound spectrum which yields the difference between the distances of the target from the sensor at the two points in time, from which difference the target distance is then calculated according to the spherical wave model.

The present invention relates to a method and to a sensor for determining the distance of sound generating targets with respect to the sensor by means of acoustic signals subjected to a Fourier transformation.
DE-OS (German Unexamined Published Patent Application) 3,936,359 discloses the use of a sensor arrangement composed of a plurality of sensors to determine the direction and distance of sound generating targets, with acoustic sensors being employed to determine the target direction. A seismic sensor is additionally employed to determine the target distance. A line characteristic of the target in the air and ground sound spectra is measured and the Doppler shift between these lines as well as the propagation speed of the corresponding waves are used to calculate the radial target velocity and from it, under consideration of the bearing angle, the target distance. Aside from the fact that a number of sensors are required to determine the target distance, the propagation speed of sound waves in the ground relative to the propagation speed of sound waves in the air fluctuates greatly depending on the type of ground involved so that this propagation speed must be determined which requires the formation of a cross spectrum of the signals received from two sensors.

Method and sensor for determining the distance of sound generating targets


Porous microparticles of high-purity tantalum may be processed in a vacuum plasmatron using a hollow cathode and spraying apparatus in which the coolant is in the form of a metal surface. In one embodiment, the initial powder of tantalum is introduced through a coaxial hole in a hollow cathode and supplied to a vertical column of plasma by inert gas and exposed to heating to temperatures close to the melting point of tantalum. The atomizing tantalum particles are directed through a hole in the anode and collide with a rotating inclined tantalum substrate and cooled from within water, thereby flattened and solidifying the particles.

With evolution and a microminiaturization of microprocessor engineering and electronics, the need for high-capacitance tantalum capacitors has rapidly increased. Qualifying demands on tantalum powder for use in electrolytic capacitors on purity and developed surface of powder particles are very high and can not always be achieved by known means of powder metallurgy.
There are well-known methods of processing high purity metal powders using vacuum-arc, plasma and electron beam heating of initial metals. Similarly, the known subsequent centrifugal atomization of a melt and cooling to form grain-like or flake-like metal particles have many merits, such as refining the microstructure, giving homogeneous distribution of many parameters, and forming an amorphous phase. However, these methods are inconvenient in view of the high melting point of tantalum. In particular, the collision of the melted particles with a cooled metal surface (usually the copper) results in contaminating the refractory drops with the constituents of the impacted metal surface.
One conventional production method of a tantalum powder for anodes of electrolytic capacitors includes mechanical milling tantalum ingots. The resulting powder has the porous structure similar to agglomerated powder and fits the requirements of developed surface, but does not meet the requirements of surface contamination, which substantially impairs parameters of capacitors. Thus, what is needed is an improved method and apparatus for plasma processing of tantalum particles.

Method and an apparatus of plasma processing of tantalum particles


A bicycle frame set comprising a main frame and a rear wheel suspension system including a swing-arm, a first link member and an intermediate lower link member. The swing arm has a forward end pivotally connected to the main frame. The swing-arm pivots such that a rear wheel axle on the swing-arm pivots about the lower pivot point on the frame with a constant radius of rotation. The first link member is pivotally connected to the main frame at a link pivot point, and has a displaceable lower end pivotable about the link pivot point. The intermediate lower link member is pivotally connected between the first link member and the swing-arm. The first link member rotates in a direction opposite to the rotation of the swing-arm as the suspension system compresses. A shock absorber is disposed between the first link member and the main frame.

Rear wheel suspension systems have been used on a variety of two-wheeled vehicles, including motorcycles, scooters and bicycles, for providing improved rider comfort and increased performance.
Rear wheel suspensions on pedal powered bicycles have become increasingly popular, and generally provide a rider with the benefits of a more comfortable ride and better control over the bicycle. Such bicycle suspension systems improve ride quality by absorbing the shocks incurred from encountering ground obstacles, rather than transmitting them through the frame to the rider. By maintaining greater contact between the tire and the ground, the suspension also provides the rider with better control for accelerating, braking, and cornering.
For a suspension to be suitable for use on a bicycle, it must be efficient. Ideally, a perfect rear wheel suspension would compress only in reaction to ground forces but not to drive-train or braking forces. Unwanted suspension movement resulting from drive train forces wastes rider energy. Bicycle suspensions can be designed to react principally to ground forces, and such that drive-train and braking forces which act thereon are limited, by careful selection of suspension type and geometry.
Several types of rear wheel suspensions exist. One of these suspension systems comprises attaching the rear axle directly to a swing-arm which pivots around a single fixed pivot axis on the forward main frame. In such a system, the pivot point around which the rear wheel axle rotates is simply the pivot point at which the swing-arm is attached to the frame. This type of suspension benefits from being simple and, if the single fixed pivot is correctly placed and the suspension geometry is correctly chosen, this type of suspension can be effective. However, the possible locations for the main pivot are often limited by traditional frame geometry and by the necessity for mounting other components such as the shock absorber and the front derailleur.
Another type of suspension system which is currently growing in popularity, and which enables a rear wheel travel path which defines a quadratic trajectory, comprises a four-bar linkage in which two different linkages or pairs of linkages are attached to the main frame of the bicycle. A third member, to which is attached the rear axle, is engaged with each of these two linkages. In such a four-bar linkage suspension, the center of rotation of the rear axle is not fixed, as in the fixed pivot axis suspensions, and varies with the relative position of the linkages. Thus, as the suspension moves, the instantaneous center of rotation changes. Such a variable pivot point (VPP) system accordingly allows for a non-constant rate of change between the rear wheel axle and the bottom bracket of the main frame portion.
Both of the above types of suspensions have their advantages, however most known suspension designs of either type have associated disadvantages. For example, known single/fixed pivot rear suspensions generally require the shock absorber for the single pivot swing arm to be located relatively high in the main frame of the bicycle and therefore result in a relatively high overall center of gravity of the bicycle. This is disadvantageous in many bicycling applications, particularly when covering steep or mountainous terrain. Further, traditional single pivot suspensions assemblies often have a suspension structure with a center of mass which is off-center relative to the bottom bracket of the frame, resulting in fore-aft weight imbalances. Such weight imbalances can result in reduced maneuverability of the bicycle.
There exists therefore a need for an improved bicycle rear suspension which addresses at least some of the forgoing problems with known designs.

Rocky Mountain Bicycles - a division of Procycle Group Inc.


A method for of connects cut edges of a thermosensitive transfer film having a plurality of color frame units each comprising at least a yellow frame, a magenta frame and a cyan frame arranged in a straight line in the order of the yellow frame, the magenta frame, and the cyan frame where a frame includes a defective part. Each frame has a transfer starting mark. The method includes the steps of cutting the film at a position of the yellow frame precedent to the magenta frame so that the transfer starting mark of the yellow frame is broken, cutting the film at a position rearward of the cyan frame and forward of the transfer starting mark of a succeeding yellow frame so as to remove the magenta and cyan frames from the film, and connecting both cut edges of the film with each other with the transfer starting mark of the yellow frame precedent to the magenta frame maintained.

Field of the Invention
The present invention generally relates to a method or connecting the edges of two cut parts of a thermal transfer film to be used in carrying out color printing, and particularly relates to a method for adhering a precedent part and a succeeding part thereof with each other after defective regions are removed therefrom.

Method for adhering thermosensitive transfer film to be used for color printing

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An exhaust system for an internal combustion engine of a vehicle includes an exhaust gas pipe, at least one branch pipe branching off from the exhaust gas pipe, for example, a pressure pipe (22), as well as at least one support device (38) supporting at least one branch pipe in relation to an exhaust system component. The support device (38) includes a carrier element (42) fixed to the exhaust system component, a clamping element (44) pressing at least one pressure pipe (22) against the carrier element (42), as well as a clamping (tensioning) device (58) acting between the carrier element (42) and the clamping element (44) for tensioning the clamping element (44) in relation to the carrier element (42).

In case of an exhaust system having such a configuration, the pressure in the exhaust system can be inferred by means of a pressure sensor connected to a pressure pipe provided by a branch pipe. If such a pressure pipe is provided with a pressure sensor each, for example, upstream and downstream of a particle filter in the exhaust system, then the pressure drop in the particle filter and thus the coating thereof with soot particles filtered out of the exhaust gas stream can be inferred on the basis of the pressure in the exhaust system that was detected by these two pressure sensors.


A method comprising reading out first lines of pixels of a sensor, when the first lines are read out in a sequence of the first lines in a first direction along the sensor also reading out different second lines of the pixels of the sensor, when the second lines are read out in a sequence of the second lines in a different second direction along the sensor and interleaving the read outs from the first lines of pixels and the different second lines of pixels.

Technical Field
The exemplary and non-limiting embodiments relate generally to digital image creation and, more particularly, to improving the quality of images taken using a rolling shutter image sensor.
Brief Description of Prior Developments
Digital images are created using pixel sensors that convert light energy into an electrical signal. Most common image sensors have pixel sensors arranged in rows and columns and have associated electrical circuitry. The circuitry reads out the electrical signals from which an image can be formed. When a flash is used the quality of the image can be impaired. Different methods have been used to prevent or correct the image created using a flash. One method that has been used is to combine two images, one with flash and one without flash. Various methods of this type generally do not generate a quality image because of latency involved in the capture, take too long or use too much memory.

Method and apparatus for obtaining image


A method for measuring an AC current in a conductor in which a DC current also exists includes the steps of (A) obtaining a first AC current measurement; (B) obtaining a measure of a power factor, fundamental frequency component, and second harmonic component; and (C) adjusting the first AC current measurement in accordance with an error value to obtain a corrected current measurement. The error value is determined as a function of the power factor, fundamental frequency component, and second harmonic component.

Electronic metering of electrical energy is a mature field of technology, and today's metering products must minimize hardware cost to be competitive. Typically, one of the major cost elements in a current or Watt-hour meter is the current transformer responsible for accurately reproducing the waveforms of the current to be measured. Normally, the current to be measured is the current component at the power frequency, 60 Hz for systems in the United States and 50 Hz for many international systems. However, in addition to the power frequency currents, there are harmonic currents and DC currents that can be present. These harmonic and DC currents can adversely affect the performance of current transformers designed to operate at the power frequency. This is a particularly serious concern where extremely accurate billing information is required.
Previous metering technologies have used a variety of current sensing techniques. Generally, these techniques offer a compromise of accuracy for power frequency current with and without DC current present. The DC current tends to saturate magnetic materials, and consequently it adversely affects accuracy. Typical current sensing materials, such as Supermalloy, tend to be expensive and are priced proportional to weight or volume. Accordingly, a consequence of the presence of DC current is the need for more magnetic material to obtain the same AC accuracy, which in turn results in higher costs. Therefore, a need exists for a current measurement technique that will improve power frequency metering accuracy in the presence of DC current.

Current measurement methods and apparatus employing second harmonic scaling


A dialysis machine includes a control unit having a user interface; a heater(s) located separate from the control unit; a supervisory processor located with the control unit; a delegate control processor located with the heater(s), the delegate control processor in communication with the supervisory processor and configured to receive load cell, heater(s) plate and supply bag temperature sensor inputs; and a sub-delegate heater(s) processor in communication with the control processor and configured to control power to the heater(s). The machine can also include primary and secondary monitoring processors that perform a safety check to the control processing and monitor the load cell.

It is known to use delegating or cascading processing in medical systems, such as a dialysis system. The trend has been to use faster, more powerful processors, which can handle an increasing number of software related tasks. One drawback of faster processing is increased cost. Another drawback of faster processing is increased electromagnetic interference ("EMI"), which is particularly important in a medical environment.
Another consideration in distributed processing is the physical configuration of the medical machine. For example, a machine having a single housing for all components does not have cabling constraints. A machine having multiple components or discrete subassemblies, however, presents cabling issues. It is desirable to minimize electrical connections for ease of use and reliability.
There is, accordingly, a need to provide an effective, low cost, low EMI distributed processing system, and in particular, one that can mitigate the number of wire connections made between different discrete components of a medical machine or system.

Distributed processing system and method for dialysis machines


A method and apparatus for creating pre-stressed zones in concrete. In one embodiment, a circular blade is coated with a chemical which retards the setting of the concrete. The circular blade is then rolled through the wet concrete, thus transferring the retarding chemical from the blade into the concrete. The region of wet concrete that has the retarding chemical introduced into it does not set until after the surrounding concrete has set and shrunk, thus creating a pre-stressed zone which typically manifests itself as a crack, visible upon setting of the wet concrete. Other embodiments describe alternative ways of introducing the chemical into the wet concrete.

1. Field of the Invention (Technical Field)
The present invention relates to a method and apparatus for creating pre-stressed zones in concrete through the introduction of a chemical while the concrete is in a liquid stage.
2. Description of Related Art
After a slab of concrete has been poured, one or more pre-stressed zones are then created in the slab. These pre-stressed zones act to guide cracks along straight and predetermined pathways. Typically, such pre-stressed zones are created by cutting through an upper portion of the concrete with a circular saw that is made to travel in a relatively straight line across the slab. Use of such a saw, therefore, requires that the concrete first be allowed to harden. Hardened concrete is quite abrasive and thus typically requires a diamond coated cutting blade with a constant flow of water applied thereto. This process is both slow and expensive. There is thus a present need for a method and apparatus for installing pre-stressed zones in concrete in a fast and inexpensive manner.
The present invention is directed to a method for creating a pre-stressed zone in wet concrete which includes providing wet concrete, providing a chemical capable of retarding, delaying, or inhibiting the setting of wet concrete, physically penetrating a top surface of the wet concrete, placing the chemical below the top surface of the wet concrete, and allowing the wet concrete to set.
In the method, penetrating a top surface can include rolling a substantially circular blade at least partially through a portion of the wet concrete, as well as pressing a blade at least partially into a portion of wet concrete. The chemical can be sprayed into an opening in the wet concrete, or the chemical can be sprayed onto a blade that is subsequently placed at least partially into the wet concrete. The chemical used in the present invention can also be saturated into a rope which is then at least partially disposed beneath a surface of the concrete.
Regardless of how the chemical is added to the wet concrete, after the chemical has been added, the surface of the wet concrete can optionally be smoothed.
The chemical used in the present invention preferably contains a hydrocarbon solvent and more preferably contains aromatic 100 and/or mineral spirits. Desirable results can also be obtained when sugar-water is used.
The apparatus of the present invention also includes introducing a chemical below a top surface of wet concrete. This apparatus preferably comprises a roller with a blade that is disposed at least partially around an outer surface of the roller, an axle fixedly or rotatably secured to the roller and substantially axially aligned therewith, one or more handles fixedly or rotatably connected to the roller, and a chemical application system which applies a chemical to the blade.
The blade can have a plurality of orifices disposed radially therethrough, and through which the chemical is excreted. Or, the chemical can be applied to the blade with a spraying system.
A pump can be coupled to the roller such that when the roller is rotated, a volume of chemical is pumped which is proportional to the amount of rotation experienced by the roller. A plurality of pistons can be radially disposed within the roller. A cam-shaped member can be attached to an axle thereof such that rotation of the roller causes the cam-shaped member to reciprocate the pistons, thus pumping the chemical.
One or more chemical-distributing wipers can be provided which spread chemical across the blade. Further, one or more wet concrete scrapers can be provided which help to remove wet concrete that sticks to the blade.
The apparatus can be powered by a mechanism, including but not limited to one or more electric motors, gas motors, pneumatic motors, hydraulic motors, combinations of these, etc. The power mechanism can be directly coupled to the apparatus, or a drive mechanism can be provided which transfers power from the power mechanism to the roller or the axle. The power mechanism can be disposed internal of or external to the roller.
The present invention also relates to an apparatus for introducing a chemical below a top surface of wet concrete which includes at least one propulsion member; a power source having an internal power source, an external power source, and/or combinations thereof; a movably positional blade; and a chemical application system.
The apparatus can also have one or more guide mechanisms. The guide mechanism can be one or more tracks, a string guide, and/or a laser guide.
One or more vibrators can also be provided, and the propulsion member can include at least one rotatable leg member and/or at least one wheel. The chemical application system can apply a chemical onto a surface of the blade, and/or apply the chemical directly into a depression of the wet concrete.
An automated controlling mechanism can be provided, which can optionally include a microcontroller.
The present invention also relates to a method for creating a pre-stress zone in wet concrete which includes providing a rope saturated with a chemical, disposing the rope at least partially within wet concrete, and allowing the wet concrete to set. The apparatus can include a rope holder, and the rope holder can have a spool and/or a spool holder.
Disposing the rope at least partially within the wet concrete can include disposing the rope at least partially around a circumference of a substantially circular rotatable blade. Optionally, after disposing the rope within the wet concrete, the wet concrete can be smoothed.
The present invention also relates to an apparatus for inserting a chemical-saturated rope below a top surface of wet concrete which includes a roller, an axle at least substantially axially aligned with the roller, at least one handle, and a blade circumferentially disposed around the roller. The blade can include a channel, a groove, an indentation, or a trough.

Chemical induced pre-stressed zones in concrete


A brake caliper of a hydraulic brake system comprises several pistons, each of which is slidably disposed in a cylinder along the axis of the cylinder, several brake pads that are forced against a brake disk by the pistons upon actuation of the brake, and at least one spring device having a base and opposite legs that extend from the base to the brake pads. The opposite legs extend from a side of the base to a brake pad that is disposed on the opposite side.

Hydraulic bicycle disk brakes are known to bias the brake pads by a spring device against respective pistons. As a result, the brake pads always abut against the piston so as to avoid a rattling noise and ensure a sliding-free operation of the brake pad. In this connection, it is important to adjust the force of the spring device such that it is smaller than the return force of the piston so as not to markedly influence the return function of the pressure chamber gasket surrounding the piston. At the same time, the force of the spring device should be high enough to ensure a good abutment of the brake pad against the piston.
Known spring devices have a base from which, for each brake pad, two legs extend in approximately perpendicular fashion to the base along the edges of the pads of the brake pads such that the pad is framed by the two legs. Two projections are provided at the ends of the legs and engage behind the pads. These known spring devices have a drawback in that they require a relatively large available space. Therefore, such spring devices are disadvantageous, in particular for four-piston brake calipers where four individual pads are provided.
Thus, a need exists to overcome the problems with the prior art systems, designs, and processes as discussed above.


A sensor element provided with a silicon substrate having a semiconductor circuit, a sensing-element portion formed on the silicon substrate and connected to the semiconductor circuit, and a cavity portion formed by removing a silicon substrate portion below the sensing-element portion, in which a removal resistance region having resistance against substrate removal is provided in the silicon substrate between the semiconductor circuit and the cavity portion.

1. Field of the Invention
The present invention relates to a sensor element which is fabricated on a semiconductor circuit by using a micromachining technology, as well as a manufacturing method thereof.
FIGS. 7A and 7B are schematic diagrams of a conventional sensor element disclosed in, for example, WO93/26051. In FIG. 7A, reference numeral 1 denotes a substrate, and 2 denotes a substrate-removing hole. An unillustrated sensing-element portion serving as a sensor element is provided in a region surrounded by the substrate-removing holes 2 on the substrate 1. Because the sensor uses a temperature change, a crystalline anisotropic etching technology based on a wet process using a solution is used so as to remove a substrate portion in a range surrounded by the substrate-removing holes 2 to form a cavity portion in the substrate below the sensing-element portion, whereby the substrate 1 and the sensing-element portion are separated and thermally isolated to prevent the heat from escaping to the substrate 1. With this sensor, it is ensured that the square region surrounded by the substrate-removing holes 2 is oriented in the (110) direction in the crystalline orientation of the substrate. In the crystalline anisotropic etching technology, the amount of substrate removal with respect to the (111) plane is small. Consequently, if the substrate is removed on the basis of this phenomenon, a desired region of the substrate which is principally surrounded by four (111) planes including the (110) direction is removed. In this way, a substrate portion which is desired to be left can be defined by the substrate-removing holes, thereby making it possible to fabricate an integrated sensor element.
However, when the substrate is removed in the above-described wet process, the erosion of the substrate at the (111) planes which are desired to be left is not nil, so that a region of the substrate which is larger than the region surrounded by the substrate-removing holes is removed. Particularly, when an attempt is made to form a highly integrated element, a semiconductor circuit for processing a signal from the sensing-element portion should be provided in the substrate in the vicinity of the sensing-element portion. Hence, there has been a problem in that if the region of the substrate larger than the region surrounded by the substrate-removing holes is removed, the breakdown of the circuit occurs, and the element fails to function as the sensor.
In addition, in the wet process, when the sensor element is removed the solution and is dried, the sensing-element portion may adhere to the bottom of the removed substrate portion and breaks down. To overcome this problem, a substrate removing technology based on a dry processing using xenon difluoride gas or the like has been proposed, as disclosed in WO96/23229. In the dry process, the drying step which is essential to the wet process is not used, there is an advantage in that the breakdown of the sensor is nil. However, since substrate removal occurs isotropically from the substrate-removing holes without conforming to the crystalline orientation, a region of the substrate larger than in the wet process is removed. Accordingly, there has been a problem in that the high integration of the sensor element is made more difficult than the wet process.

Sensor element with removal resistance region


A column section is disposed within a thermostatic chamber within a clean room, a section for analog controlling each portion of the column section is disposed within the clean room and outside of the thermostatic chamber, and a section for digital controlling the analog control section is disposed outside of the clean room.

1. Field of the Invention
The present invention relates to a charged particle beam exposure apparatus, and particularly, to a charged particle beam exposure apparatus which is suitable for application to the manufacture of LSI's.
2. Description of the Related Art
There are two cases for the structure of a charged particle beam exposure apparatus, that is the case of integrating a main body of the apparatus including a charged particle generator section and a sample carrier section and a control unit for controlling these units and the case of separating the main body of the apparatus from the control unit. In the case of separating these units, it is general that the apparatus mechanism portion is separated from the control section. In this case, it is necessary to have an analog signal cable wired from the control section to the apparatus main body, with a maximum limit of about 10 m for the wiring distance between the two units. Further, in the case of integrating the apparatus main body and the control unit, an area for the installation of the apparatus is unnecessarily increased.
In order to minimize the necessary floor space within a clean room at the side of the user of the apparatus, it is desirable that only a portion requiring the stability of cleanness, temperature and humidity is installed within the clean room. From this viewpoint, having the charged particle beam exposure apparatus by integrating the main body of the apparatus and the control unit is a problem because it increases an unnecessary space for the floor area for the installation of the apparatus within the clean room. Further, in the case of separating the main body of the apparatus from the control unit to structure the charged particle beam exposure apparatus, there is a problem that the layout of the apparatus is constrained by the wiring of an analog signal cable.
As described above, there is a problem that constraints in the floor space and in the layout of the apparatus are applied to the user of the apparatus, because no consideration has been given either to reduce the floor space for the installation of the apparatus in the clean room or to guarantee the layout of the apparatus with high degree of freedom to match the idea of the configuration of the manufacturing line at the side of the user of the apparatus.

Charged particle beam exposure apparatus

Hitachi Instrument Engineering Co., Ltd.


A system and method interpolates a full color image from an array of single color sensors. Each sensor measures a single color, e.g., red, green or blue. The measured color values are stored as an array of data. For each data element, a plurality, e.g., four, gradients are computed that specify the color and/or luminance difference along different linear paths extending through the data element. At least some of the gradients are computed using a first order color differential and a second order color or luminance differential along the selected path. One or more gradients are then selected based on a comparison of the gradients to a computed threshold. Using the data elements along the path of the selected gradient or gradients, the missing color values are interpolated. The interpolation algorithm also utilizes first and second order color differentials.

1. Field of the Invention
The invention relates to digital imaging and, more specifically, to interpolating a color image using multiple gradients.
2. Background Information
In digital color imaging, an image plane having a rectangular array of sensor elements is typically used to measure varying intensities of electromagnetic radiation, such as visible light. For color imaging, it is desirable to capture image data in three color planes, typically red, green and blue (RGB). When the three color planes are combined, it is possible to create high-quality color images. Capturing three color planes is typically accomplished by placing a color filter array (CFA) between the lens and the sensors of the array. For each sensor of the array, the CFA filters all but one of the color planes. Thus, each sensor measures one of red, green, or blue intensity.
One of the most common CFA arrangements or patterns is described in U.S. Pat. No. 3,971,065 to Bayer, and is known as a Bayer array or pattern. The Bayer array is a four-by-four, repeating pattern of color filters as shown below.
G R G R
B G B G
G R G R
B G B G
Several methods have been developed for interpolating the "missing" color elements for each sensor, e.g., the red and blue values at a "green" element, the blue and green values at a "red" element, etc. These methods, however, are either too expensive computationally or produce undesirable artifacts in the resulting image. Thus, a need exists for a method for accurately and efficiently generating missing color values in a digital image sensing system.

System and method for interpolating a color image

Hewlett-Packard Development Company, L.P.


Embodiments of the invention are directed toward methods for an effective blind, passive, splicing/tampering detection. The methods of the various embodiments of the invention use a natural image model to detect image splicing/tampering with a model that is based on statistical features extracted from a given test image and multiple 2-D arrays generated by applying the block discrete cosine transform (BDCT) with several different block-sizes to the test images. Experimental results have demonstrated that the new splicing detection scheme outperforms state-of-the-art methods by a significant margin when applied to the Columbia Image Splicing Detection Evaluation Dataset.

1. Field of the Invention
Embodiments of the invention are directed toward an apparatus and methods for an effective blind, passive, splicing/tampering detection. In particular, various embodiments of the invention relate to apparatus and methods for the use of a natural image model to detect image splicing/tampering where the model is based on statistical features extracted from a given test image and multiple 2-D arrays generated by applying the block discrete cosine transform (DCT) with several different block-sizes to the test images.
2. Description of Background Art
Replacing one or more parts of a host picture with fragment(s) from the same host picture or other pictures is called a photomontage or image tampering. Image tampering may be defined as a malicious manipulation of an image to forge a scene that actually never happened in order to purposely mislead observers of the image.
Image splicing is a simple and commonly used image tampering scheme for the malicious manipulation of images to forge a scene that actually never exists in order to mislead an observer. Image splicing is often a necessary step in image tampering. In image splicing, a new image is formed by cropping and pasting regions from the same or different image sources. Modern digital imaging techniques have made image splicing easier than ever before. Even without post-processing of the image, image splicing detection can hardly be caught by human visual systems. Hence, high probability of detection of image splicing detection is urgently needed to tell if a given image is spliced without any a priori knowledge. That is, image splicing/tampering detection should be blind in nature.
Researchers recently have made efforts on image splicing detection due to the increasing needs of legal forensics. For example, a method on blind splicing detection has been reported in T.-T. Ng, S.-F. Chang, and Q. Sun, "Blind detection of photomontage using higher order statistics," IEEE International Symposium on Circuits and Systems 2004, Vancouver, BC, Canada, May, 2004. However, the reported results of a 72% success rate for tampering detection over the Columbia Image Splicing Detection Evaluation Dataset are not satisfactory for image splicing/tampering detection.
Another background art approach, utilizing statistical moments of characteristic functions has been reported in Y. Q. Shi, G. Xuan, D. Zou, J. Gao, C. Yang, Z. Zhang, P. Chai, W. Chen, and C. Chen, "Steganalysis based on moments of characteristic functions using wavelet decomposition, prediction-error image, and neural network", IEEE International Conference on Multimedia & Expo 2005, Amsterdam, Netherlands, July, 2005. In this approach, 78-dimensional (78-D) feature vectors are used for universal steganalysis. The first half of features are generated from the given test image and its 3-level Haar wavelet decomposition. The second half of features are derived from the prediction-error image and its 3-level Haar wavelet decomposition. Considering the image and its prediction-error image as the LL0 (Low-Low 0) subbands, there are 26 subbands totally. The characteristic function (CF) (i.e., the discrete Fourier transform (DFT) of the histogram) of each of these subbands is calculated. The first three moments of these CFs are used to form the 78-D feature vectors. The above-mentioned steganalysis scheme provides good results when attacking data hiding algorithms operating in the spatial domain but further improvement in detection probability performance is desirable.
Based on the above discussed features, a more advanced technology has been developed in C. Chen, Y. Q. Shi, and W. Chen, "Statistical moments based universal steganalysis using JPEG 2-D array and 2-D characteristic function," IEEE International Conference on Image Processing 2006, Atlanta, Ga., USA, Oct. 8-11, 2006. In this background art method, 390-dimensional (390-D) feature vectors are developed for universal steganalysis. These 390-D features consist of statistical moments derived from both image spatial 2-D array and JPEG 2-D array, formed from the magnitudes of JPEG quantized block discrete cosine transform (DCT) coefficients. In addition to the first order histogram, the second order histogram is also considered and utilized. Consequently, the moments of 2-D CF's are included for steganalysis. Extensive experimental results have shown that this steganalysis method outperforms in general the background art in attacking modern JPEG steganography including OutGuess, F5, and MB1. However, as with the above, further improvements in detection performance is desirable.
In our own background art developments, we have developed a powerful steganalyzer to effectively detect the advanced JPEG steganography in Y. Q. Shi, C. Chen, and W. Chen, "A Markov process based approach to effective attacking JPEG steganography", Information Hiding Workshop 2006, Old Town Alexandria, Va., USA, Jul. 10-12, 2006. In this work, we first choose to work on the image JPEG 2-D array. Difference JPEG 2-D arrays along horizontal, vertical, and diagonal directions are then used to enhance changes caused by JPEG steganography. Markov processes are then applied to modeling these difference JPEG 2-D arrays so as to utilize the second order statistics for steganalysis. In addition to the utilization of difference JPEG 2-D arrays, a thresholding technique is developed to greatly reduce the dimensionality of transition probability matrices, i.e., the dimensionality of feature vectors, thus making the computational complexity of the proposed scheme manageable. Experimental results have demonstrated that this scheme has outperformed the existing steganalyzers in attacking OutGuess, F5, and MB1 by a significant margin. However, as with the above, further improvement in detection performance is desirable.
From the discussion above, it is clear that image splicing detection is of fundamental importance in the art of image splicing/tampering detection. The blind splicing detection methods of the background art have typically achieved a probability of successful detection rate of 72%-82% against the Columbia Image Splicing Detection Evaluation Dataset. Thus, there is a need in the art for further improvement in image splicing/tampering detection performance with blind methods for authenticating images.

Method and apparatus for a natural image model based approach to image/splicing/tampering detection


The present disclosure relates to an epicyclic gear train comprising a driving pinion (3), driving a plurality of planetary gears (7). Each planetary gear rotates around a planetary axis (23), which has first (9) and a second (11) interconnected gears with different numbers of teeth. The first gear (9) meshes with a first ring gear (19), which is stationary, and the second gear (11) meshes with a second ring gear (25) which is thereby made to rotate about a central axis (21) of the planetary gearing. An adjusting arrangement is arranged to alter the distance between the central axis (21) and each planetary axis (23), such that gearing backlash can be substantially eliminated.

Such a gear train is known e.g. from U.S. Pat. No. 5,957,804-A, which describes a gear train for an industrial robot. The axial distance between a first and a second ring gear can be adjusted, and the gears of each planetary gear may be conical to allow a floating planetary holder.
One general problem associated with planetary gears is to improve their performance and reliability.


An electronic tampering detection system is applied to a blank which can be formed into a package through the use of closure tabs which are coated with an electrically conductive adhesive. An electronic chip or CPU is applied to the blank and electrically conductive traces are printed or otherwise formed on the blank to connect the CPU to a first pair of the closure tabs to form an electric circuit. Other traces on the blank connect the first pair of closure tabs to the other closure tabs to form an enlarged circuit. The CPU has procedure memory, data memory, a power source, a clock and communication means associated therewith. If a package is opened accidentally or intentionally before it should be opened by way of the closure tabs the electric circuit is broken and a time stamp from the CPU clock is stored in the data memory for later retrieval. The circuit can be formed as resistances in parallel and an analog to digital converter can be used to provide an appropriate signal to the CPU. The electric circuit can cover a large portion of the blank's surface to provide a signal in the event of unauthorized penetration of the formed package.

Folded paper board (cardboard) packages (boxes, containers) are widely used to organize and ship a variety of contents. Many such contents are at risk for tampering or theft. In such scenarios, the paper board package is opened by an unauthorized person, giving unauthorized access to the contents of the package. The contents may be stolen and replaced with inactive versions of the contents, part or all of the units may simply be removed from the package (stolen), or the contents may be contaminated by the addition of toxic substances to the contents. The unauthorized person might then reseal the package, allowing it to continue in the distribution chain, disseminating its altered contents.
It is widely acknowledged that it would be useful to have a means of detecting unauthorized access to the contents of cardboard packages to protect against theft and alteration of the contents thereof. Although there are many areas in which such a device might prove useful, there has recently been expressed particular concern by the FDA about the possibility of tampering with pharmaceuticals, pharmaceutical components, and food products.


A process and device for determining a run-away condition of a rotation-speed controlled, permanent-excited synchronous motor are described. The process continuously checks, when a rotation speed controller is active and for a predetermined constant rotation speed setpoint, several conditions, either alone or in combination, and generates an error signal if the particular condition or the combination of conditions, when continuously checked, is/are always satisfied during at least a predetermined time interval. These conditions include: determining if the magnitude of a measured deviation in the rotation speed between a measured actual rotation speed value and the predetermined constant rotation speed setpoint increases or reaches a limit value; if the magnitude of a control variable present at the output of a rotation speed controller increases or reaches a limit value; and if the magnitude of a measured acceleration value and/or the magnitude of a torque-producing current increases or reaches a limit value.

The present invention relates to a a process for determining a run-away condition of a rotation-speed controlled, permanent-excited synchronous motor and to a device for carrying out the process.
Rotation-speed controlled, permanent-excited synchronous motors are commercially available. Certain procedures are implemented that can be used to identify the correct pole position of the permanent-excited pole rotor for commutating the synchronous motor. All these procedures are relatively reliable and accurate. However, commutation errors can occasionally occur which can cause the rotation-speed controlled, permanent-excited synchronous motor to run away. Synchronous motors in that run away can damage or destroy a production machine or machine-tool in which the synchronous motor is installed.
Although commutation errors occur very rarely, they have to be prevented at all cost because of the potential for consequential damages. A commutation error can have many causes which depend on the components which cooperate with the drive. It is therefore not sufficient to merely analyze the errors that have occurred in the past.
To this date, the rotation speed controller of the rotation-speed controlled, permanent-excited synchronous motor is monitored to determine if the rotation speed controller has reached a limit setting. It can be safely assumed that a fault has occurred when a maximum or minimal controlling variable is generated at the output of the rotation speed controller during a predetermined time interval. The predetermined time interval is typically preset at the factory to, for example, approximately 100 msec, and the length of this time interval can be increased by a user. However, it is impossible to determine from the error signal the reason why the rotation speed controller has reached the limit setting. There can be numerous reasons why the rotation speed controller has reached the limit setting. Of these reasons, only one represents a commutation error that can cause the rotation-speed controlled, permanent-excited synchronous motor to run away.
A commutation error may already have accelerated a load to a high speed after the expiration of the predetermined time period, depending on the inertial mass of a connected load. If an error message is generated, a converter connected to the rotation-speed controlled, permanent-excited synchronous motor is switched off by a conventional pulse blocking device. Depending on the existing friction, the load then coasts to a stop. If the load was already accelerated to a high speed during the predetermined time period, then the pulse blocking device can no longer prevent a crash. For this reason, production machines and machine tools are protected by a limiter in form of a buffer that intercepts a load that coasts to a stop.
It would therefore be desirable and advantageous to provide an improved process and device for determining a run-away condition of a rotation-speed controlled, permanent-excited synchronous motor, which obviates prior art shortcomings and is able to specifically bring the motor and an associated drive to a safe stop.

Process and device for determining a run-away condition of a rotation-speed controlled, permanent-excited synchronous motor


A gradation corrector for use in a television receiver which can subject a signal at any luminance level to non-linear correction to provide optimum image quality. Memory stores therein luminance histogram of an input signal. On the basis of the data, a circuit detects a total frequency, a circuit detects luminance distribution, and a circuit detects the expanse of the luminance distribution. A circuit calculates a fixed value to be added. Further, a circuit detects a minimum luminance level, and a circuit detects an average luminance level. A circuit calculates an accumulation starting point and a circuit calculates an accumulation stopping point. An adder adds the calculated fixed value to the data in the memory. A circuit accumulates the results in the range from the accumulation starting point to the accumulation stopping point. The accumulation result is stored in memory. A circuit detects the maximum cumulative value, and a circuit normalizes all the data stored in the memory by use of this maximum value. The normalized data are stored in a memory. Thus, the input signal is subjected to optimum normalization by use of the normalized data.

The present invention relates to a gradation corrector used in correcting the gradation of a video signal in a television receiver, a video tape recorder, a video camera, a video disk or the like.
In recent years, great importance has been attached to gradation correctors in order to provide more clearer images which are required with the increase in size of color television receivers and the improvement in image quality thereof, and more especially, in order to expand the dynamic range of an image on a CRT by passing a video signal through a non-linear amplifier to correct the gradation of the video signal. A U.S. patent application Ser. No. 838,844 entitled "Gradation corrector" was filed on Feb. 21, 1992 (on basis of Japanese patent application No. 3-32794 filed on Feb. 2, 1991). A U.S. patent application Ser. No. 846,143 entitled "Video signal gradation corrector" was filed on Mar. 5, 1992 (on basis of Japanese patent application No. 3-58657 filed on Mar. 22, 1991). A new U.S. patent application entitled "Video signal gradation corrector" is filed on basis of Japanese patent application Nos. 3-123647 and 3-123468 filed on May 28, 1991. These three patent application have been assigned to the same assignee with the present application.
An explanation will be given of a gradation corrector proposed precedently to the present application.
FIG. 3 is a block diagram of the preceding gradation corrector. In FIG. 3, reference numeral 1 designates a black detection circuit for detecting a signal corresponding to a black portion in an input luminance signal to output a black detection signal. Numeral 2 designates a gain control circuit for gain-controlling the black detection signal in accordance with a gain control signal to output an amplified black detection signal. Numeral 3 designates an adder for adding the input luminance signal to the amplified luminance signal to output an output luminance signal. Numeral 4 designates a black peak-hold circuit for holding the black peak level of the output luminance signal to output the voltage with the level as a black peak hold voltage. Numeral 5 designates a comparator for comparing the black peak-hold voltage with a reference voltage. Numeral 6 designates a voltage source for generating the reference voltage.
The operation of the gradation corrector thus constructed will be explained with reference to FIG. 4. FIG. 4 shows waveforms of signals at several points of the gradation corrector of FIG. 3.
First, an input luminance signal a is inputted to the black detection circuit which extracts the black signal corresponding to the portion lower than a predetermined value of the luminance signal to be outputted as a black detection signal b. The black detection signal b is inputted to the gain control circuit 2 which controls its gain in accordance with a gain control voltage f to output an amplified black detection signal c. The signal c is inputted to the adder 3 which adds it to the input luminance signal a to output an output luminance signal d with an extended dynamic range on the black side. The signal d is outputted externally and also inputted to the black peak-hold circuit 4. The peak-hold circuit 4 detects the highest black luminance signal level to output the voltage with the level as a black peak-hold voltage e. The comparator 5 compares the peak-hold voltage e with a reference voltage r generated by the voltage source 6 to feed back a difference between them as a gain control voltage f to the gain control circuit 2. This feed-back system is stabilized when the black peak voltage e becomes equal to the reference voltage g. In this way, when there is a black-detection component, if the corresponding peak voltage is controlled to always be equal to the reference voltage, the dynamic range is extended on the black side to provide gradation correction.
FIG. 5 is a block diagram of another precedent gradation corrector. Reference numeral 7 designates an A/D converter for converting an input luminance signal into a digital value. Numeral 8 designates a histogram memory for obtaining a luminance histogram of the input luminance signal. In general, the luminance level enters an address of the memory 2 and the frequency enters as the data thereof. Numeral 9 designates a histogram accumulation circuit for accumulating the output signals from the histogram memory 8. Numeral 10 designates a cumulative histogram memory for storing therein the result of accumulation by the histogram accumulation circuit 9. In general, the luminance level enters an address of the memory 9 and the frequency enters as data thereof. Numeral 11 designates a look-up table operating circuit which normalizes the respective data from the cumulative histogram memory 10 so that the maximum value resulting from accumulation becomes the maximum value of the output luminance signal. Numeral 12 designates a look-up table memory for storing therein the output signal normalized by the look-up table operating circuit 11. In general, the input luminance level enters an address of the memory 12 and the frequency enters as the data thereof. Numeral 13 designates a D/A converter which converts an output luminance signal in digital value corrected by the look-up table memory 12 into an analog signal. Numeral 14 designates a timing control circuit 14 which makes sequencing of various operations and control for the memories.
The operation of the gradation corrector circuit thus constructed will be explained below. FIG. 6 shows the manner of conversion in the circuit.
First, an input luminance signal a is inputted to the A/D converter 7 which converts it into a digital value to be outputted as a converted input luminance signal h. The histogram memory 8 takes the converted input luminance signal h as an address and adds 1 to the data at the address for each access. By performing this operation during one vertical scanning period, it is possible to detect a histogram distribution of the input luminance signal a. The histogram distribution is shown in FIG. 6(A). The contents of the histogram memory 8 are cleared at every predetermined period to make all the data zero. Usually, this period is set for one vertical scanning period or its integer-times.
Next, data of the histogram memory 8 are read sequentially from the address of 0 by the histogram accumulation circuit 9 which in turn the output signals i. The accumulation result j is stored in the cumulative histogram memory 10. It is shown in FIG. 6(B).
The look-up table operating circuit 11 determines a normalization coefficient so that the maximum value of the cumulative histogram memory 10 is the maximum output luminance level. The look-up table operating circuit 11 performs a normalization operation on all the data in the cumulative histogram memory 10 by use of the determined normalization coefficient. The operation result is stored in the look-up table memory 12. It is shown in FIG. 6(C).
Data in the look-up table memory 12 is read with a converted input luminance signal h as an address and the read data is outputted as a corrected output luminance signal as a corrected output luminance signal m. FIG. 6(D) shows a histogram of the corrected luminance signal m. The D/A converter converts the corrected output luminance signal m into an analog signal d to be outputted.
The timing control circuit 14 controls the operations of various circuits so that the respective parts are performed in the order as described above.
The above precedent correctors have the following defects. The first corrector has a problem that since only a black signal is subjected to gradation correction, a high luminance level signal or an intermediate luminance level signal is not gradation-corrected, and so the dynamic range cannot be improved sufficiently.
The second corrector which is directed to "histogram flattening processing" can extend the dynamic range to 100%. But a normal video signal when subjected to such processing results in quite unlike an actual image.

Video signal gradation corrector which prevents excessive extension of the dynamic range

Matsushita Electric Industrial Co., Ltd.