A method for processing a silver halide photographic light-sensitive material which comprises a support, a silver halide emulsion layer provided on the support and a hydrophilic colloid layer adjacent to the silver halide emulsion layer, comprising a step of developing the photographic light-sensitive material with a developing solution containing an ascorbic acid compound as a developing agent, wherein the photographic material contains an amine compound in at least one of the silver halide emulsion layer and the hydrophilic colloid layer and an nucleating agent within a range of 0 to 20 mg per 1 m2 of the photographic light-sensitive material, and wherein the amine compound has a distribution coefficient (log P) of 1 or more in a n-octanol/water system.

The present invention relates to a method for processing silver halide photographic light-sensitive materials.
Heretofore, in the printing field, in order to obtain ultra-high contrast images, lith development has been carried out for the past long years. However, it is inevitable to carry out processing, employing a developer containing a low amount of sulfite salts. As a result, said developer results in problems with stability (aerial oxidation) and has been unsuitable for processing employing an automatic processor.
Separate from this, though ultra-high contrast is not obtained, a so-called xe2x80x9crapid accessxe2x80x9d system has been employed which improves the stability of the developer by employing a PQ or MQ developer containing a large amount of sulfite salts. However, the quality of halftone dot quality is markedly degraded because an increase in contrast due to the lith development process is not achieved. Accordingly, said system does not sufficiently meet customers"" needs who demand high halftone dot quality.
However, said rapid access system exhibits excellent processing stability and has been widely accepted. On the other hand, in order to obtain high contrast (ultra-high contrast) equivalent to that of said lith development, employing said PQ or MQ developer, a system is employed in which processing is carried out employing a PQ or MQ developer at a high pH (approximately 11.5), while nucleating agents such as hydrazine compounds are incorporated into the light-sensitive materials.
Further, by incorporating one of the nucleation accelerators described, for example, in U.S. Pat. No. 5,316,889, or amine compounds described in U.S. Pat. No. 4,947,354 along with active hydrazine compounds into light-sensitive materials, a decrease in the pH of the developer is achieved whereby the system has resulted in improved stability.
In recent years, in the printing field, higher efficiency of work has been sought along with an increase in work volume. Accordingly, it has been demanded that imagewise exposed light-sensitive materials are subjected to more rapid photographic processing. Further, from the viewpoint of environmental protection, a decrease in effluent during photographic processing, resulting from a decrease in replenishment amount, has been an important issue to be overcome.
Accordingly, in order to accomplish the lower replenishment amount as well as said rapid processing, it is required that development is completed in a short time and high processing stability is achieved during high-volume processing. However, in said rapid access system, since high coating of silver is required to obtain a density high enough for carrying out print-in onto a printing plate, in order to, for example, finish development within 50 seconds, the development temperature should be raised to at least 38xc2x0 C. As a result, a developer is maintained at a relatively high temperature, whereby said developer is degraded, resulting in a decrease in stability.
Further, in said system employing hydrazine compounds, it is possible to constitute a system which results in high density at a low coating weight of silver. However, since it passes through two processes of an induction period and the following reduction sensitization, it is impossible to achieve required development within a short period of time, and further, the processing stability is markedly inferior to said rapid access system.
European Patent No. 0758761 describes a system in which light-sensitive materials do not comprise nucleating agents but comprise amine compounds, and fairly high density is obtained. However, since the PQ and MQ developers are employed, high-volume processing stability has been found to be insufficient when rapid processing is carried out under said low replenishment.
Accordingly, a method has been sought to overcome said drawbacks.
An objective of the present invention is to provide a method for processing a silver halide photographic light-sensitive material which is applicable to rapid processing at a relatively low temperature, and exhibits excellent sharpness, high sensitivity, as well as excellent stability during high-volume processing.
Said objective of the present invention has been achieved employing items 1 through 10 described below.
(Item 1) A method for processing a silver halide photographic light-sensitive material which comprises a support, a silver halide emulsion layer provided on the support and a hydrophilic colloid layer adjacent to the silver halide emulsion layer, comprising a step of developing the photographic light-sensitive material with a developing solution containing an ascorbic acid compound as a developing agent,
wherein the photographic material contains an amine compound in at least one of the silver halide emulsion layer and the hydrophilic colloid layer and an nucleating agent within a range of 0 to 20 mg per 1 m2 of the photographic light-sensitive material, and wherein the amine compound has a distribution coefficient (log P) of 1 or more in a n-octanol/water system.
(Item 2) The method according to the above Item 1, wherein the photographic light-sensitive material contains silver halide grains and 50 percent or more of the silver halide grains in a silver halide emulsion layer are spectrally sensitized.
(Item 3) The method according to the above Item 1, wherein a replenishing amount of the developing solution is 250 ml or less per 1 m2 of the photographic light-sensitive material.
(Item 4) The method according to the above Item 3, the replenishing amount of the developing solution is within the range of 75 to 200 per 1 m2 of the photographic light-sensitive material.
(Item 5) The method according to the above Item 1, wherein the developing is operated under the temperature of 35xc2x0 C. or less, and developing time is 50 sec or less.
(Item 6) The method according to the above Item 5, wherein the developing is operated under the temperature within the range of 20 to 33xc2x0 C., and the developing time is within the range of 5 to 15 sec.
(Item 7) The method according to the above Item 1, wherein the developing solution is prepared by dissolving a solidified developer containing the ascorbic acid compound in water.
(Item 8) The method according to the above Item 1, wherein the photographic light-sensitive material contains the amine compound in an amount within the range of 1 to 1000 mg per 1 m2 of the photographic light-sensitive material.
(Item 9) The method according to the above Item 8, wherein the photographic light-sensitive material contains the amine compound in an amount of within the range of 10 to 500 mg per 1 m2 of the photographic light-sensitive material.
(Item 10) The method according to the above Item 10, wherein the photographic light-sensitive material contains the amine compound in an amount of within the range of 20 to 200 mg per 1 m2 of the photographic light-sensitive material.
The present invention will now be detailed below.
In the present invention, A method for processing a silver halide photographic light-sensitive material comprising a support, a silver halide emulsion layer provided on the support and a hydrophilic colloid layer adjacent to the silver halide emulsion layer, comprising a step of developing the photographic light-sensitive material with a developing solution containing an ascorbic acid compound as a developing agent, wherein the photographic material contains an amine compound in at least one of the silver halide emulsion layer and the hydrophilic colloid layer and an nucleating agent within a range of 0 to 20 mg per 1 m2 of the photographic light-sensitive material, and wherein the amine compound has a distribution coefficient (log P) of 1 or more in a n-octanol/water system. By so doing, it has been found that rapid processing is achievable at a relatively low temperature; high sensitivity is maintained even after high-volume processing; excellent sharpness is exhibited; and excellent stability during high-volume processing is also exhibited.
Amine compounds according to the present invention will now be described.
Amine compounds according to the present invention, which has a distribution coefficient (log P) of 1 or more in an n-octanol/water system, are incorporated into a silver halide photographic light-sensitive material which has nucleating agents in an amount within the range of 0 to 20 mg per 1 m2 of the photographic material. The photographic material is processed employing a developing solution comprising ascorbic acid compounds as a developing agent. Thus, it is possible to obtain the effects described in the present invention. Further, by employing the method for processing the silver halide light-sensitive photographic material of the present invention, it is possible to obtain images with high density.
In the present invention, said distribution coefficient (log P) in an n-octanol/water system is defined by General Formula (1) described below.
log P=log ([X octanol]/[X water])xe2x80x83xe2x80x83General Formula (1)
wherein X octanol represents the saturation concentration of said amine compound in octanol at 1 atmospheric pressure and 25xc2x0 C., and X water represents the saturation-concentration of said amine compound in water.
The distribution coefficient (log P), defined by said General Formula (1), of the amine compounds according to the present invention is preferably 1 or more, more preferably 3 or more, and still more preferably 4 or more.
Said log P can be determined and calculated referring to methods described in xe2x80x9cYakubutsu no Kozo Katsusei Sokan (Structure Activity Correlation of Pharmaceuticals)xe2x80x9d, edited by Kozo Katsusei Sokan Konwakai, Kagaku no Ryoiki, Zokan No. 122, Kohnando, J. Am. Chem. Soc., 86, 5175 (1964), and J. Org. Chem., 32, 2583 (1976).
Preferred structural features of amine compounds having the distribution coefficient (log P) in an n-octanol/water system, as described above, will now be described.
Amine compounds according to the present invention preferably have at least one secondary or one tertiary amino group as well as a group comprised of at least three reiterated ethyleneoxy units. Examples of said compounds are described in U.S. Pat. No. 4,975,354. Further, said ethyleneoxy unit is preferably bonded directly to the nitrogen atom of said tertiary amino group.
Listed as examples of amine compounds according to the present invention are monoamines, diamines, and polyamines. Said amines may be aliphatic amines or may contain an aromatic or heterocyclic portion. Aromatic, aliphatic, and heterocyclic groups in said amines may be substituted or unsubstituted groups. Said amines are preferably compounds having at least 20 carbon atoms.
The amine compounds according to the present invention include compounds represented by General Formula (2), (3), (4), or (5) described below.
Y((X)nxe2x80x94Axe2x80x94B)mxe2x80x83xe2x80x83General Formula (2)
wherein Y represents a group which adsorbs onto silver halide; X represents a divalent bonding group comprised of a hydrogen atom, a carbon atom, a nitrogen atom or a sulfur atom; A represents an alkylene group; B represents an amino group, an ammonium group or a nitrogen-containing heterocyclic group which may be substituted; m represents 1, 2, or 3; and n represents 0 or 1.
N(R1)(R2)xe2x80x94R3xe2x80x94(X)nxe2x80x94SMyxe2x80x83xe2x80x83General Formula (3)
wherein R1 and R2 each represent a hydrogen atom or an aliphatic group, or R1 and R2 may bond to each other to form a ring; R3 represents a divalent aliphatic group; X represents a divalent heterocyclic ring having at least one of a nitrogen atom, an oxygen atom, or a sulfur atom as the hetero atom; n represents 0 or 1; M represents a hydrogen atom, an alkali metal atom, an alkali earth metal atom, a quaternary ammonium, a quaternary phosphonium atom, or amidino group; Y represents an integer of 1 or 2; and when M is a divalent atom, Y is 1. The amine compounds represented by Formula (3) may be in the form of acid addition salts.
In the present invention, bis type tertiary amine compounds, which have a distribution coefficient (log P) of 3 or more and are represented by General Formula (4) described below, are preferably employed.
General Formula (4)
wherein n represents an integer of 3 to 50, and more preferably an integer of 10 to 50; and R4, R5, R6, and R7 each represent an alkyl group having from 1 to 8 carbon atoms, or R4 and R5, and R6 and R7 may bond to each other to form a heterocyclic ring.
In the present invention, further, bis type secondary amine compounds, which have a distribution coefficient (log P) of 3 or more and are represented by General Formula (5) described below, are preferably employed.
General Formula (5)
wherein n represents an integer of 3 to 50, and more preferably an integer of 10 to 50; and R8 and R9 each represent an alkyl group having at least 4 carbon atoms.
Specific examples according to the present invention are illustrated below. However, the present invention is not limited to these examples.
Further, in the present invention, amine compounds listed in European Patent No. 0,364,166 may be preferably employed.
From the viewpoint to obtain the effects described in the present invention, the added amount of said amine compounds in the silver halide light-sensitive photographic material according to the present invention is preferably from 1 to 1,000 mg/m2, is more preferably from 10 to 500 mg/m2, and is most preferably from 20 to 200 mg/m2.
The nucleating agents according to the present invention will now be described.
In the present invention, the nucleating agents represents a compound which leads to increase contrast of image due to contagious development, when a PQ developing solution or a MQ developing solution is used. Conventionally, hydrazine compounds are used as the nucleating agents. Listed as conventional nucleating agents known in the art are compounds disclosed in Japanese Patent Publication Open to Public Inspection Nos. 62-640, 62-235938, 63-104046, 63-296031, and 64-13545. In the present invention, it is preferable that the light-sensitive photographic material contains the nucleating agent within the range of 0 to 20 mg per m2 of the light-sensitive photographic material. More preferably, the light-sensitive photographic material does not contain the nucleating agent.
Ascorbic acid compounds according to the present invention will now be described.
The ascorbic acid compounds, which are employed in developers and developer replenishers used in the method for processing the silver halide photographic light-sensitive material of the present invention, will now be described.
In the present invention, the term xe2x80x9cascorbic acid compoundsxe2x80x9d is used to include ascorbic acid, and isomers, derivatives, or salts thereof. Ascorbic acid developing agents have been very well known in said photographic field, and specifically include the compounds described below. However, the present invention is not limited to those described below.
Herein listed are L-ascorbic acid, D-ascorbic acid, L-erythroascorbic acid, D-glucoascorbic acid, 6-deoxy-L-ascorbic acid, L-rhamnoascorbic acid, D-glucoheptaascorbic acid, imino-L-erythroascorbic acid, imino-D-glucoascorbic acid, imino-6-deoxy-L-ascorbic acid, imino-D-glucoheptaascorbic acid, sodium isoascorbate, L-glycoascorbic acid, D-galactoseascrobic acid, L-araboascorbic acid (erythorbic acid), sorboascorbic acid, ascorbic acid and salts thereof. Listed as salts are alkali metal salts such as sodium salts and potassium salts.
In the present invention, it is possible to employ a developer replenisher and a fixer replenisher prepared by employing solid processing agents. The solid processing agents, as described herein, refer to processing agents in the form of powders, tablets, pills, and granules, and if desired, are subjected to a moisture resistance treatment.
The powders, as described herein, refer to aggregates of minute crystals, while said granules refer to grains having a diameter of 50 to 5,000 xcexcm, which are prepared by applying said powders to a granulation process. The tablets, as described herein, are those which are prepared by applying compression molding to said powders or said granules.
Of said solid processing agents, the tablet agent is preferably employed due to its high replenishment accuracy, as well as ease of handling.
Photographic processing agents may be solidified employing several optimal means. Said means include one in which a concentrated photographic processing solution, or minute powder or grain-shaped photographic processing agents, are kneaded together with water-soluble binders, and the resulting mixture is molded, and another means in which a covering layer is formed in such a manner that a water-soluble binder is sprayed onto the surface of temporarily molded photographic processing agents. (It is advised to refer to Japanese Patent Publication Open to Public Inspection Nos. 4-29136, 4-85535, 4-85536, 4-85533, 4-85534, and 4-172341.)
Preferred methods for producing tablets include a method in which powdered solid processing agents are granulated, and subsequently, molding is carried out employing a tableting process. Solid processing agents produced as above exhibit better solubility and storage stability than that which is produced by simply blending solid processing agent components and molding the resulting mixture employing the tableting process. As a result, said solid processing agents exhibit the advantage in which photographic performance is also stabilized.
Employed as the granulation methods for forming tablets are those known in the art such as rolling granulation, extrusion granulation, compression granulation, crushing granulation, agitation granulation, fluidized-bed granulation, and spray-dry granulation. The average grain diameter of the resulting grains is preferably from 100 to 800 xcexcm, and is more preferably from 200 to 750 xcexcm, from the point of view in which non-uniformity of components or so-called segregation rarely occurs when the resulting grains are blended and are subjected to compression under an application of pressure for preparing tablets.
Further, the preferred size distribution is so that at least 60 percent of the resulting granules are in the deviation from xc2x1100 to xc2x1150 xcexcm. Subsequently, the resulting granules are subjected to pressure compression employing compression devices known in the art such as an oil pressure pressing device, a single-tablet type tablet machine, a rotary type tablet machine, and a briquetting machine. Solid processing agents, which are obtained by pressure compression, may be of any desired shape. However, from the viewpoint of productivity as well as ease of handling, and minimization of dust problems in workshop, a cylindrical shape or a so-called tablet shape is preferred.
It is more preferable that each component such as the alkali agent, the reducing agent, the preservative, and the like is individually granulated. By so doing, said effects are more pronounced.
It is possible to produce tablet processing agents employing common methods described, for example, in Japanese Patent Publication Open to Public Inspection Nos. 51-61837, 54-155038, and 52-88025; and British Patent No. 1,213,808. Further, it is possible to produce granular processing agents employing common methods described, for example, in Japanese Patent Publication Open to Public Inspection Nos. 2-109042, 2-109043, 3-39735, and 3-39739. Still further, it is possible to produce powder processing agents employing common methods, described, for example, in Japanese Patent Publication Open to Public Inspection No. 54-133332; British Patent Nos. 725,892 and 729,862; and German Patent No. 3,733, 861.
From the viewpoint of solubility and the effects of the objective of the present invention, in the case of tablet agents, the apparent density of said solid processing agents is preferably from 1.0 g to 2.5 g/cm3. An apparent density of no less than 1.0 g/cm3 is preferred from the point of strength of the obtained solid materials, while said density of no more than 2.5/cm3 is preferred from the point of solubility of the obtained solid materials. When solid processing agents are granular or powder, the apparent density is preferably from 0.40 to 0.95 g/cm3.
Solid processing agents are preferably employed as a developer. Further, they may be employed as other photographic processing agents such as fixing agents and rinsing agents. Further, developers as well as fixing agents can be excluded from the liquid hazardous substance regulation. It is most preferable that all processing agents be comprised of solid processing agents. However, it is preferable that at least developers and fixing agents are comprised as solids.
Only one component of the processing agent may be solidified. Preferably, however, all components are solidified. It is preferable that each component be individually molded as a solid processing agent and be individually packaged. Further it is preferable that each component is packaged in the order in which they are repeatedly charged.
When processing agents are solidified, all alkali agent and reducing agent are preferably prepared as solid processing agents. Further, when prepared as tablets, one tablet is comprised of at most three agents, but most preferably, one tablet is comprised of only one agent. Further, when solid processing agents are prepared by dividing at least two agents, a plurality of resulting tablets or granules is included in the same package.
When a fixing agent is solidified, it is preferable that all of the main fixing agents, preservatives, and hardening agents such as aluminum salts are solidified. In the case of tablets, one tablet is comprised of at most three agents, and more preferably, one tablet is comprised of one agent or two agents. Further, when a solid processing agent is prepared by dividing into at least two agents, a plurality of these tablets or granules are preferably included in the same package. Specifically, from the viewpoint of handling, it is preferable that aluminum salts are solidified.
Listed as packaging materials of solid processing agents are polyethylene (prepared by either a high or a low pressure method), polypropylene (either stretched or unstretched), polyvinyl chloride, polyvinyl acetate, nylon (either stretched or unstretched), polyvinylidene chloride, polystyrene, polyvinyl carbonate, vinylon, eval, polyethylene terephthalate (PET), other polyesters, hydrochlorinated rubber, acrylonitrile-butadiene copolymers, synthetic resin components such as epoxy-phosphoric acid based resins (polymers described in Japanese Patent Publication Open to Public Inspection No. 63-63037, and polymers described in Japanese Patent Publication Open to Public Inspection No. 57-32952), and pulp.
It is preferable that said components be individually employed. When employed as a film, films may be adhered through lamination, or may be employed as the coating layer. Further, said film may be used individually.
Further, it is more preferable that various types of gas barrier layers be employed in such a manner that, for example, an aluminum foil is provided between said synthetic resinous films, or aluminum evaporated synthetic resinous films are employed.
Still further, in order to improve the storage stability of said solid processing agents, as well as to minimize stain formation, the oxygen permeability of said packaging materials is preferably no more than 50 ml/m2xc2x7atmosphere (at 20xc2x0 C. and 66 percent relative humidity), and is more preferably no more than 30 ml/m2xc2x7atmosphere.
The total thickness of said laminated layers or single layer is preferably from 1 to 3,000 xcexcm, is more preferably from 10 to 2,000 xcexcm, and still more preferably from 50 to 1,000 xcexcm.
Said synthetic resinous film may be comprised of one (polymer) resinous layer, but may also be comprised of at least two laminated layers comprised of (polymer) resinous layers.
When processing agents are packaged employing water-soluble film, and are bound employing water-soluble binding agents or covered with the same, said water-soluble films or water-soluble binders are preferably comprised of polyvinyl alcohol based, methyl cellulose based, polyethylene oxide based, starch based, polyvinylpyrrolidone based, hydroxypropyl cellulose based, pullulan based, dextran based or gum Arabic based, polyvinyl acetate based, hydroxyethyl cellulose based, carboxymethyl cellulose based, carboxymethyl hydroxyethyl cellulose sodium salt based, poly(alkyl) oxazoline based, and polyethylene glycol based components. Of these, specifically, polyvinyl alcohol based and pullulan based components are preferably employed from the point of view of their covering or binding effects.
From the viewpoint of the storage stability of solid processing agents, the dissolving time of said water-soluble film, and crystal deposition in the automatic processor, the thickness of said water-soluble film is preferably from 10 to 120 xcexcm, is more preferably from 15 to 80 xcexcm, and is most preferably from 20 to 60 xcexcm.
In addition, said water-soluble film is preferably thermoplastic. The resulting thermoplasticity not only renders a heat seal treatment and ultrasonic fusion treatment easy, but also makes it possible to more preferably exhibit covering effects.
Further, the tensile strength of said water-soluble film is preferably from 4.9xc3x97106 to 490xc3x97106 N/M2, is more preferably from 9.8xc3x97106 to 245xc3x97106 N/m2, and is most preferably from 14.7xc3x97106 to 98xc3x97106 N/m2. Said tensile strength is determined employing the method described in JIS Z-1521.
Further, in order to minimize damage due to contact with moisture in the atmosphere such as high humidity, rain or fog, and sudden contact with scattered water or wet hands during the storage, transportation and handling of photographic processing agents, which have been packaged with water-soluble film or are bound with water-soluble binders, said photographic processing agents are preferably packaged with moisture-resistance packaging materials. The thickness of said moisture-resistant packaging materials is preferably from 10 to 150 xcexcm. Said material is preferably one which is selected from polyolefin films such as polyethylene terephthalate, polyethylene, polypropylene, kraft paper capable of having moisture resistant effects employing polyethylene, waxed paper, water-resistant cellophane, glassine, polycarbonate, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyamides, polycarbonates, acrylonitrile based and metal foil such as aluminum, and metalized polymer film. Said materials may be composite materials of these. Further, preferably employed as said water-resistant packaging materials are degradable plastics, especially biodegradable or photodegradable plastics.
Cited as said biodegradable plastics are those comprised of natural polymers, microorganism generating polymers, easily biodegradable synthetic polymers, and plastics blended with biodegradable natural polymers. Listed as photodegradable plastics are those having, in the main chain, groups which result in bond breakage upon excitation by ultraviolet rays. In addition to those listed above, preferably employed may be those which simultaneously result in photodegradation and biodegradation.
Specific examples of said representative compounds will now be listed below.
Biodegradable plastics include:
(a) natural polymers: polysaccharides, cellulose, polylactic acid, chitin, chitosan, polyamino acid, or modified compounds thereof;
(b) microorganism generating polymers: PHB-PHV (being a copolymer of 3-hydroxybutylate and 3-hydroxyvalerate), and microorganism generating cellulose;
(c) easily biodegradable synthetic polymers: polyvinyl alcohol and polycaprolactone, or copolymers or mixtures thereof;
(d) plastics blended with biodegradable natural polymers: easily biodegradable natural polymers include starch and cellulose, which are added to plastics so as to result in shape disintegration properties; and
as photodegradable plastics,
(e) introduction of a carbonyl group for photodecomposition.
Further, UV absorbers may be added to accelerate the disintegration.
Employed as said degradable plastics may be those which are generally described in xe2x80x9cKagaku to Kogyo (Science and Industry)xe2x80x9d, Volume 64, No. 10, pages 478 to 484 (1990), xe2x80x9cKino Zairyo (Functional Materials)xe2x80x9d, July Issue, 1990, pages 23 to 34. Further, it is possible to employ commercially available degradable plastics such as Biopol (manufactured by ICI, Eco (manufactured by Union Carbide Co., Ecolite (manufactured by Eco Plastic Co.), Ecostar (manufactured by St. Lawrence Starch Co.), and Nackle P (manufactured by Nippon Unicar Co.).
The moisture permeability of said moisture resistant packaging materials is preferably no more than 10 gxc2x7mm/m2xc2x724 hours, and is more preferably no more than 5 gxc2x7mm/m2xc2x724 hours.
In combination with ascorbic acid compounds (said ascorbic acid, and erythorbic acid) according to the present invention, it is preferred to employ auxiliary developers such as 3-pyrazolidones (for example, 1-phenyl-3-pyrazolidone, 1-phenyl-4-methyl-3-pyrazolidone, 1-phenyl-4,4-dimethyl-3-pyrazolidone, 1-phenyl-4-ethyl-pyrazolidone, and 1-phenyl-5-methyl-3-pyrazolidone), as well as aminophenols (for example, o-aminophenol, p-aminophenol, N-methyl-o-aminophenol, N-methyl-p-aminophenol, and 2,4-diaminophenol). In this case, developing agents such as 3-pyrazolidones and aminophenols are preferably employed in an amount of 0.001 to 1.4 moles per liter of developer. Further, said ascorbic acid compounds (ascorbic acid, and erythorbic acid) are preferably employed in an amount of 0.05 to 1 mole per liter of developer.
Further, it is possible to employ dihydroxybenzene based developing agents in combination. Listed as said dihydroxybenzene based developing agents are, for example, hydroquinone, chlorohydroquinone, bromohydroquinone, isopropylhydroquinone, methylhydroquinone, 2,3-dochlorohydroquinone, and 2,5-dimethylhydroquinone. Of these, hydroquinone is most commonly employed. These are commonly employed in an amount of 0.08 to 0.3 mole per liter of developer, and are preferably employed in an amount of 0.1 to 0.25 mole.
 less than  less than Processing greater than  greater than
In the method for processing the silver halide light-sensitive photographic materials of the present invention, after the fixing step, said light-sensitive materials are washed with water and/or processed in a stabilizing bath. Said stabilizing bath is employed for stabilizing images upon adjusting the pH (3 to 8 after processing) of the layer. Accordingly, said stabilizing bath comprises inorganic and organic acids and salts thereof, or alkali agents and salts thereof (for example, borates, metaborates, borax, phosphates, carbonates, potassium hydroxide, sodium hydroxide, ammonia water, monocaroxylic acid, dicarboxylic acid, polycarboxylic acids, citric acid, oxalic acid, malic acid, and acetic acid are employed in combination). In addition, said stabilizing bath comprises aldehydes (for example, formalin, glyoxal, and glutaraldehyde); chelating agents (for example, ethylenediaminetetraacetic acid or alkali metal salts thereof, nitrilotriacetates and polyphosphates); antifungal agents (for example, phenol, 4-chlorophenol, cresol, o-phenylphenol, chlorophene, dichlorophene, formaldehyde, p-hydroxybenzoic acid ester, 2-(4-thiazoline)-benzimidazole, benzoisothiazoline-3-one, dodecyl-benzyl-ammonium-chloride, N-(fluorodichloromethylthio)phthalimide, and 2,4,4xe2x80x2-trichloro-2xe2x80x2-hydroxydiphenylether); image color control agents and/or remaining color improving agents (for example, heterocyclic ring containing compounds having a mercapto group as the substituent specifically including sodium 2-mercapto-5-sulfonate-benzimidazole, 1-phenyl-5-mercaptotetrazole, 2-mercaptobenzthiazole, 2-mercapto-5-propyl-1,3,4-triazole, and 2-mercaptohypoxanthine). Of these, antifungal agents are preferably incorporated into said stabilizing bath. These may be replenished in either liquid or solid form. In the solid form when replenished, it is possible to employ the method for producing solid processing agents as well as the method for using the same, described below.
When the silver halide photographic light-sensitive materials according to the present invention are subjected to photographic processing after exposure, it is preferable that development is carried out at no higher than 35xc2x0 C. for no more than 50 seconds. From the viewpoint of rapid processing, the development time is preferably no more than 20 seconds, is more preferably 15 seconds, and is most preferably from 5 to 15 seconds. The development temperature is more preferably no higher than 33xc2x0 C., and is most preferably from 20 to 33xc2x0 C.
When the development temperature exceeds 35xc2x0 C., problems may occur in which ascorbic compounds employed as developing agents tend to become unstable.
Further, in the method for processing silver halide light-sensitive materials of the present invention, said processing is carried out in such a manner that a definite amount of the developer, proportional to the processed area, is replenished. In order to decrease the effluent volume,: the replenishment rate of the developer replenisher is preferably no more than 250 ml per m2, and is more preferably from 75 to 200 ml per m2 of the photographic material.
The silver halide emulsion layers employed in the silver halide light-sensitive photographic materials according to the present invention will now be described.
The halogen composition of silver halide employed in said light-sensitive materials is preferably silver chlorobromide or silver iodobromide having a silver chloride content ratio of 50 to 85 mole percent. The average grain size of silver halide grains is preferably no more than 0.7 xcexcm, and is most preferably from 0.3 to 0.1 xcexcm. The shape of silver halide grains may be tabular, spherical, cubic, tetrahedral, octahedral, and other shapes. Further, the grain size distribution is preferably narrow, and specifically, a so-called monodispersed emulsion is preferred in which 90 percent, and preferably 95 percent, of total grains are included within xc2x140 percent of the average grain size.
In at least one of the formation process or the growth process of silver halide grains, Group 8 metal salts such as cadmium salts, zinc salts, lead salts, thallium salts, ruthenium salts, osmium salts, iridium salts, or rhodium salts, or complex salts containing these elements are preferably added, and of these, rhodium salts and ruthenium salts are particularly preferred. The added amount is preferably from 10xe2x88x928 to 10xe2x88x924 mole per mole of silver.
Silver halide emulsions and their preparation methods are detailed in Research Disclosure (RD) Volume 176, Item 17643, pages 22 and 23 (December 1978) or references cited therein.
Silver halide emulsions are preferably chemically sensitized. Further, said silver halide emulsions may be spectrally sensitized to the desired wavelength employing sensitizing dyes. Preferably, 50% or more of the silver halide grains in the silver halide emulsion are chemically sensitized.
Preferably employed as sensitizing dyes for said spectral sensitization is at least one of the sensitizing dyes represented by General Formulas (6) through (11) described below.
wherein R8, R9, and R10 each represent an acid water-solubilizing group such as an alkyl group substituted with a carboxyl group or a sulfone group; R11 and R12 each represent an alkyl group having from 1 to 4 carbon atoms; R13, R14, and R15 each represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group; and X represents a halogen atom (for example, a chlorine atom, a bromine atom, a fluorine atom or an iodine atom).
The silver halide light-sensitive photographic materials according to the present invention will now be described.
Said silver halide light-sensitive photographic materials according to the present invention comprise a support having thereon silver halide emulsion layers. It is preferable that one of the surfaces of said support is provided with an antihalation layer, and further, said antihalation layer is provided on the support surface opposite to said emulsion layers.
Further, said photographic materials according to the present invention preferably comprise a hydrophilic colloidal layer other than said silver halide emulsion layers. Said hydrophilic colloidal layer refers to a layer comprising gelatin, hydrophilic binders, and water-soluble binders, and for example, a protective layer, a backing layer, or the like is one of the embodiments of said hydrophilic colloidal layer.
Antihalation dyes are incorporated into said backing layer. Said dyes are added to said backing layer under a dissolved state and/or a dispersed state. Listed as suitable dyes are those described in Research Disclosure Item 308119.
For the purpose of minimizing fog during the production processes, storage, or photographic processing, or of the stabilizing photographic performance, it is possible to add to said light-sensitive materials according to the present many compounds known as an antifoggant or stabilizer. Said photographic emulsions and light-nonsensitive hydrophilic colloids may comprise inorganic or organic hardeners. For various purposes such as improvement of the coating, minimization of static charge, improvement of lubricating properties, improvement of emulsion dispersion, minimization of adhesion, and improvement of general photographic characteristics, it is possible to employ various types of surface active agents known in the art into the light-sensitive emulsion layers and/or light-insensitive hydrophilic colloidal layers.
It is advantageous to employ gelatin as the binder or the protective colloid of said photographic emulsions. However, it is possible to employ hydrophilic colloids other than gelatin.
For the purpose of improving dimensional stability, in the photographic emulsions employed in the present invention, used individually or in combination may be for example, alkyl acrylate, alkyl methacrylate, alkoxyacryl acrylate, alkoxyacryl methacrylate, glycidyl acrylate, glycidyl methacrylate, acrylamide, methacrylamide, vinyl ester (for example, vinyl acetate), acrylonitrile, olefin, styrene, or any of polymers having, as the monomer component, a combination of acrylic acid, methacrylic acid, xcex1,xcex2-unsaturated dicarboxylic acid, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, sulfoalkyl acrylate, sulfoalkyl methacrylate, and styrenesulfonic acid with any of said compounds.
It is preferable that in the light-sensitive materials which are processed employing the method for processing the silver halide light-sensitive materials of the present invention, at least one electrically conductive layer is provided on the support. Representative methods for forming said electrically conductive layer include those in which said layer is formed by employing water-soluble electrically conductive polymers as well as hydrophobic polymer hardeners and in which metal oxides are employed. Listed as said methods are those described, for example, in Japanese Patent Publication Open to Public Inspection No. 3-265842.
When the swelling percentage of the light-sensitive materials processed utilizing the present invention is preferably from 30 to 250 percent, and more preferably from 50 to 180 percent, it is possible to exhibit the desired effects of the present invention. The swelling percentage, as described herein, refers to the swelling ratio represented by (dxe2x88x92d0)/dxc3x97100, wherein do is the thickness of the hydrophilic colloidal layer of a light-sensitive material which has been subjected to an incubation treatment at 38xc2x0 C. and 50 percent relative humidity for three days, and d is the thickness of the hydrophilic colloidal layer of said light-sensitive material which has been immersed at 21xc2x0 C. for 3 minutes.
It is possible to apply various techniques as well as additives known in the photographic art to silver halide emulsions. These are described in said RD Volume 176, Item 7643 (December 1987) as well as Volume 187, Item 8716 (November 1979).
In the light-sensitive materials employed in the present invention, each of the emulsion layers as well as the protective layer may be comprised of a single layer or a multilayer comprised of at least two layers. In the case of a multilayer, interlayers may be provided between layers.
Listed as usable supports may be those comprised of polyesters such as cellulose acetate, cellulose nitrate, and polyethylene terephthalate; polyolefin such as polyethylene; polystyrene; baryta paper; paper coated with polyolefin; glass; and metal. If desired, these supports may be subjected to a subbing treatment.

Method for processing silver halide light-sensitive photographic material


A multilayer structure sheet for manufacturing an optical information recording medium having a multilayer structure with a plurality of recording layers is disclosed. The multilayer structure sheet comprises at least one unit structure in which a pressure sensitive adhesive layer, a recording layer, a recording layer support layer having a glass transition temperature higher than that of the pressure sensitive adhesive layer, and a recording layer are laid one on top of another in this order, and a release sheet is attached to an outside of an outermost pressure sensitive adhesive layer.

1. Field
The present invention relates to a multilayer structure sheet for manufacturing an optical information recording medium having a multilayer structure with a plurality of recording layers, a method for manufacturing a multilayer structure sheet, an optical information recording medium having a multilayer structure with a plurality of recording layers, and a method for manufacturing an optical information recording medium using a multilayer structure sheet.
2. Description of Related Art
Conventionally, as a method for manufacturing an optical information recording medium having a multilayer structure with a plurality of recording layers, a method using a multilayer structure sheet having laminates of a recording layer and a pressure sensitive adhesive layer is known in the art (e.g., Patent Literature 1). To be more specific, a multilayer structure sheet described in Patent Literature 1 has a release film attached to each of outer surfaces of a laminate of recording and pressure sensitive layers. By peeling this release film off the multilayer structure sheets and stacking and sticking the sheets over a substrate repeatedly one on top of another, an optical information recording medium having a multilayer structure can be obtained. In this type of manufacturing method using a multilayer structure sheet, a large-area optical information recording medium can be manufactured by preparing a large-size multilayer structure sheet.
However, the multilayer structure sheet as described in Patent Literature 1 is configured to have a release film attached to the recording layer, and thus involves a risk of cracking occurring in the recording layer when the release film is peeled off. With this in view, there is proposed a multilayer structure sheet so configured as to have a release film not directly attached to any recording layer (e.g., Patent Literature 2). To be more specific, the multilayer structure sheet described in Patent Literature 2 has a multilayer structure comprising a pressure sensitive adhesive layer, a recording layer and a release assisting layer arranged in this order, and a release film is attached to each of the outermost layers that are the pressure sensitive adhesive layer and the release assisting layer. With this configuration in which the recording layer is sandwiched between the pressure sensitive adhesive layer and the release assisting layer as described above, cracking in the recording layer when the release film is peeled off can be prevented from occurring.

This patent is subject to a terminal disclaimer.

Multilayer structure sheet and method for manufacturing same, and optical information recording medium and method for manufacturing optical information recording medium using multilayer structure sheet


An integrated circuit (IC) package, such as a Quad Flat Pack (QFP), has at least one lead with a tip that extends substantially perpendicular to the ends of two or more bondwires, so that there is room for more than one bondwire to be attached to it along its length. Thus, bondwires leading from die bondpads that are not adjacent to one another can be efficiently connected to the same lead in a bus-like manner.

Electronic packaging is essentially the final step in the process of fabricating an integrated circuit (IC) or "chip." In the packaging step, the semiconductor die is mounted on a leadframe, and electrical connections are made between the die and the leads of the leadframe, before encapsulating the assembly in the component body. The leadframe is typically made from a thin sheet of metal by stamping or etching. The majority of IC packages use a method known as wirebonding to make the electrical connections between the die and the leads. In wirebonding, one end of a very fine gold or aluminum bondwire (on the order of 10-100 micrometers in diameter) is attached to a bondpad on the die, and the other end is attached to an end of a lead. The end of the lead to which the bondwire is attached is sometimes referred to as a bondfinger and sometimes as a lead tip. The bondwire ends are typically attached by applying some combination of pressure and heat. The resulting weld-like or solder-like attachment or bond is commonly referred to as a wirebond. The other end of the lead extends externally to the package (component body) for connection to other circuitry when the IC is used as a circuit component. This external portion of the lead may have a stepped shape or other features to facilitate mounting it to a circuit board, but such features are not relevant to the present invention.
Many common ICs, including many application-specific integrated circuits (ASICs), are in the form of a package known as a Quad Flat Pack (QFP). As illustrated in FIG. 1, a QFP package 100 has four sides with leads 102 extending from the component body 104 on all four sides. As illustrated in FIG. 2, inside a QFP package 100 the electrical connections between the die 106 and the leads 102 are made by wirebonding with bondwires 108. (Some leads 102 and other grouped elements are not shown individually for purposes of clarity, and their omission is indicated collectively by an ellipsis (" . . . ") symbol.) Typically, one wirebond (i.e., the weld-like attachment or bond) connects or attaches one bondpad 110 to one lead 102. In general, the number of bondpads 110 dictates the number of corresponding QFP leads 102. Nevertheless, in instances in which adjacent or proximate bondpads are intended to carry the same electrical signal (e.g., device ground and power), more than one bondpad may be wirebonded to a single lead. Typically, there are numerous electrically common bondpads that lie along each of the four sides of the die, such as device ground ("VSS") and core power ("VDD").
In some packages, ground bondpads are wirebonded to diepaddle 112, which is a metal plate-like portion of the leadframe underneath the die that physically supports the die and acts as an electrical ground plane. (The leadframe is the entire stamped or etched area comprising all leads 102.) The diepaddle 112 effectively combines and consolidates the ground connections from the die and redistributes ground to a number of package lead tips. A similar structure, sometimes referred to as an interposer (not shown), can be used for distributing core power. Such structures add significant manufacturing cost and increase the size and weight of the package.
The more leads in a QFP package, the greater its size, weight, cost and complexity. Thus, it would be advantageous to minimize the number of package leads. In some instances, a package for which a component manufacturer or customer indicates a preference has too few leads to accommodate the number of bondpads of the die to be packaged. In such an instance, a larger, more complex, less economical package must be selected. Note in the QFP package 100 of FIG. 2 that a few bondpads 110a, 110b and 110c cannot be accommodated and thus have been left unattached. While in this exemplary QFP package 100 it may be that bondpads 110a, 100b and 100c are not utilized by the die 106, i.e., carry no signal in operation, and thus are not to be accommodated by any leads 102, it would be desirable to provide the option of accommodating them.
It would be desirable to provide an IC package that maximizes the number of bondpads that a given number of leads can accommodate. The present invention addresses the above-described problems and deficiencies and others in the manner described below.

System and method for providing a power bus in a wirebond leadframe package

Avago Technologies General IP (Singapore) Pte. Ltd.


An optical measurement instrument comprises operational modules (101-107) that are interconnected via a digital communication network (110). Each operational module comprises a transceiver (111-117) connected to the digital communication network and arranged to support a pre-determined digital communication protocol employed in the digital communication network. Those operational modules that include a detector further comprise an analog-to-digital converter (118) for converting a detected signal into a digital form and a digital circuitry (119) for providing digital information based on the detected signal with address data related to a particular operational module to which the digital information is to be delivered via the digital communication network. As information is transferred between operational modules via the digital communication network using the pre-determined digital communication protocol, the operational modules can be tested independently of each other using a test bench system arranged to support the pre-determined digital communication protocol.

The work in analytical biochemical laboratories and in clinical laboratories is often based on different tags or labels coupled on macromolecules under inspection. Typical labels used are different radioactive isotopes, enzymes, different fluorescent molecules and e.g. fluorescent chelates of rare earth metals. Detection of enzyme labels can be performed by utilizing its natural biochemical function, i.e. to alter the physical properties of molecules. In enzyme immunoassays colourless substances are catalysed by enzyme to colourful substances or non-fluorescent substances to fluorescent substances.
The colourful substances can be measured with absorption measurement, i.e. photometric measurement. In the absorption measurement the intensity of filtered and stabilized beam is first measured without any sample and then the sample inside one plate is measured. The absorbance i.e. the absorption values are then calculated.
The fluorescent substances can be measured with fluorescent measurement that is generally used for measuring quantities of fluorescent label substance in a sample. The most photoluminescence labels are based on molecular photoluminescence process. In this process optical radiation is absorbed by the ground state of a molecule. Due to the absorption of energy the quantum molecule rises into higher excited state. After the fast vibrational relaxation the molecule returns back to its ground state and the excess energy is released as an optical quantum. Due to losses in this process the average absorbed energies are higher than the average emitted energies.
A further measurement method is chemiluminescence measurement where emission of a substance is measured from a sample without excitation by illumination. Thus a photoluminometer suitable for photoluminescence measurements can also be used as a chemiluminometer.
Further, there is an analysing method called Amplified Luminescent Proximity Homogeneous Assay or AlphaScreen™. The function of the AlphaScreen™ method is based on the use of small beads that attach to the molecules under study. There are two types of beads that are coated with a material acting either as a donor or acceptor of singlet-state oxygen. The measurement starts, when the liquid sample is illuminated by light with a suitable wavelength e.g. 680 nm. After this, the material in the donor bead converts ambient oxygen into singlet-state oxygen. The single-state molecules have a short lifetime and they can reach only about a 200 nm distance by diffusion in the liquid. If the chemical reaction in question has taken place, both the donor and acceptor beads are bound to the same molecule and so they are sufficiently close to each other. In this case the singlet-state oxygen may reach the acceptor bead where a series of reactions is started. As the last phase of the reaction the coating material in the acceptor beads emits photons in the 500-700 nm range. If the chemical reaction has not taken place the singlet-state oxygen cannot reach the acceptor bead and the emission light is not detected. By measuring the intensity of light it is possible to conclude the efficiency of the chemical reaction.
An optical measurement instrument suitable for performing some or all of the measurements of the kind described above comprises typically at least one excitation light source for producing excitation beams to one or more samples to be measured at each time. Each excitation light source can be for example a flash lamp or a laser source. An optical path from an excitation light source to a sample may contain for example lenses, fibers, mirrors, dichroic mirrors, optical filters, monochromators and/or other optical elements. The optical measurement instrument further comprises at least one detector for detecting emission beams emitted by the samples to be measured at each time, and for producing detection signals responsive to the detected emission beams. Each detector can be for example a photodiode or a photomultiplier tube. An optical path from the sample to the detector may contain for example lenses, fibers, mirrors, dichroic mirrors, optical filters, monochromators, and/or other optical elements. Each sample to be measured is stored in one of a plurality of sample wells that are built on a sample plate, e.g. a microtitration plate. The optical measurement instrument may comprise, for example, a movable sledge adapted to receive the sample plate. Due to the fact that the sample plate is movable, the samples can be measured in a temporally successive manner so that each sample is in turn the sample that is currently being measured. The optical measurement instrument may further comprise a processing device for producing a measurement result for each sample to be measured on the basis of the detection signal related to that sample.
An optical measurement instrument of the kind described above is a complicated apparatus from the viewpoints of manufacturing, testing, and outsourcing the manufacturing and/or testing. This causes a need to modularize the structure of an optical measurement instrument so that the optical measurement instrument can be assembled of different operational modules such as, for example, an excitation light source module, an excitation monocromator module, a sample track module arranged to hold and move a sample plate, an emission monocromator module, and a detector module. Publication U.S. Pat. No. 6,977,722 discloses an example of an optical measurement instrument having a modular structure. A challenge related to the modularization is that the operational modules should be able to be manufactured and tested sufficiently independently of each other in order that the modular structure would provide the desired advantages.

Optical measurement instrument with data transmission


A thermoplastic methacrylimide group-containing resin composition comprised of (a) a methacrylimide group-containing polymer comprising 5 to 100% by weight of units of an imide ring structure represented by the following structural formula (I): ##STR1## wherein R.sub.1 stands for a hydrogen atom, a substituted or unsubstituted alkyl, cycloalkyl, aryl, alkaryl, aralkyl or allyl group having 1 to 20 carbon atoms,. and 0 to 95% by weight of units derived from at least one monoethylenically unsaturated monomer, and (b) a small amount of a tetramethylpiperidine derivative is described. A shaped article made from this composition has a highly improved weatherability.

(1) Field of the Invention
The present invention relates to a thermoplastic resin composition having excellent heat resistance, transparency and light resistance. More particularly, the present invention relates to a thermoplastic methacrylimide group-containing resin composition having improved weatherability.
(2) Description of the Related Art
It is known that a methacrylimide group-containing polymer is a thermoplastic resin having a high heat distortion temperature and a high transparency (see Japanese Examined Patent Publication No. 60-38404).
However, the methacrylimide group-containing polymer has a poor resistance to sunbeams, wind and rain, and heat and cold. Namely, the weatherability of the methacrylimide group-containing polymer is not satisfactory, and reduction of the transparency and degradation of the appearance are often caused. Accordingly, the poor weatherability is a very important problem in practical use of this polymer.
Attempts have been made to improve the weatherability of the methacrylimide group-containing polymer by incorporating various ultraviolet absorbers such as benzophenone type ultraviolet absorbers and benzotriazole type ultraviolet absorbers. However, even if such an ultraviolet absorber is used, a methacrylimide group-containing polymer comparable to a methyl methacrylate resin, which is a transparent resin having a highest weatherability, cannot be obtained.

Thermoplastic methacrylimide group-containing resin composition


A dynamic read/write memory in which refreshing is performed within a read/write cycle so that write recovery time is not prolonged. A word line corresponding to a current address is continuously rendered operative within a write period. When a write operation is completed, the word line is rendered operative so that refreshing is initiated. A word line is rendered operative only within a given period of a read period.

The present invention relates to a dynamic read/write memory for refreshing storage data in a normal data read/write cycle and, more particularly, to an improvement of a control circuit for controlling word lines or a column decoder for such a memory.
A so-called pseudo static RAM (to be referred to as a PSRAM hereinafter) is known as a RAM which uses memory cells (e.g., each comprising one transistor and one capacitor) requiring refreshing of storage data, which does not require the complicated timing signals used in a dynamic RAM, such as a column address strobe signal (CAS) and a row address strobe signal (RAS), and which can be used in the same manner as a normal static RAM. The refreshing operation must be performed before or after the normal read/write cycle in a conventional PSRAM. Refreshing timings must be set by a user, which can be inconvenient.
Assume that data is refreshed during address decoding or at the end of read/write access, i.e., that data refreshing is performed in parallel with data read/write access in one cycle. FIG. 1 shows a schematic arrangement of a dynamic read/write memory (DRAM), and FIGS. 2A to 2I are timing charts for explaining the operation of the DRAM. It is also assumed that a pair of bit lines BL and BL are precharged.
If address input signal ADD (FIG. 2A) is changed, or when a chip enable signal (not shown in FIG. 2) is input, a memory operation cycle is initiated. The change in signal ADD causes an address decoder (not shown) to select one word line WL1, and corresponding signal NWL1 (FIG. 2B) becomes "H". Storage data in memory cell 51 and data in dummy cell 52 are read out onto a pair of bit lines BL and BL (FIG. 2G), and a slight potential difference occurs between the bit lines. Sense amplifier 53 is then operated in response to sense enable signal SAE (FIG. 2C), and the potential difference is amplified by amplifier 53. Subsequently, column decoder 54 is operated in response to column decoder enable signal CDE (FIG. 2E), and data signals on the bit lines BL and BL are decoded. The decoded signals appear on a pair of data lines DL and DL (FIG. 2H). The data signals on the lines DL and DL are waveshaped by input/output circuit 55. As a result, the waveshaped signals are output as active data from data input/output terminal I/O (FIG. 2I).
Signal CDE is supplied as a pulse signal to decoder 54 and becomes "L" after input/output circuit 55 latches active data. When signal CDE becomes "L", signal NWL1 becomes "L" to render line WL1 inoperative. Amplifier 53 is then disenabled in response to "L" of signal SAE, and lines BL and BL are precharged.
Refreshing drive signal RWL2 (FIG. 2D) is supplied to word line WL2 to render sense amplifier 53 operative, and data is rewritten in memory cell 51. During the refreshing operation, data need not be output from the memory. Signal CDE is kept "L", and column decoder 55 is kept inoperative. In this case, the active data latched by input/output circuit 55 appears at terminal I/O.
The word lines (WL1, WL2) are driven in response to pulses as described above, and thus the refreshing operation can be performed in one cycle.
The present inventors developed a control circuit for switching between normal data read/write access (to be referred to as a normal operation hereinafter) and refreshing operation. The control circuit is shown in FIG. 3. In this circuit, normal operation request signal NREQ is generated by reset-set flip-flop (RS FF) 61 which is set in response to normal operation start instruction signal NSET and is reset in response to normal operation end instruction signal NRST. Refreshing operation request signal RREQ is generated by RS FF 62 which is set in response to refreshing operation start instruction signal RSET and is reset in response to refreshing operation end instruction signal RRST. Signals NREQ and RREQ are supplied as input signals to signal selection circuit 65 constituted by NAND gates 63 and 64.
An output signal from NAND gate 63 is inverted by inverter 66, and normal operation control circuit 67 is operated in response to output signal NGO from inverter 66. Similarly, an output signal from NAND gate 64 is inverted by inverter 68, and refreshing operation control circuit 69 is rendered operative in response to output signal RGO from inverter 68. In this manner, the normal and refreshing operations are switched.
The word lines are driven by control circuits 67 and 69, in response to pulses as described above. In the normal operation, particularly in the data write mode, the following problem occurs. This problem will be described with reference to the timing charts in FIGS. 4A to 4E.
Assume that write enable signal WE rises at time t0 in FIG. 4B. In this case, the circuit in FIG. 3 generates normal operation request signal NREQ and causes normal operation word line drive signal NWL1 on word line WL1 to become "H". It is further assumed that the refreshing operation has already started at time t0. At time t1, when signal RWL becomes "L" after the refreshing operation is completed, signal NWL1 (FIG. 4C), corresponding to address input signal ADD (FIG. 4A), becomes "H", and data write access is initiated. In this case, a period t(WR) (FIG. 4A) between the leading edge of write enable signal WE and the next change in signal ADD becomes long. Thus, the one-cycle period of the DRAM is undesirably prolonged, only in the write mode. In other words, when a refreshing operation is performed in the normal operation in the above-mentioned DRAM control circuit, the data write cycle time is undesirably prolonged.

Dynamic read/write memory with improved refreshing operation


A fire enhancement system for increasing the visual appearance of a fire with a simple to utilize structure. The inventive device includes an outer tube defining an interior cavity, and a fuel member positioned within the interior cavity of the outer tube. The outer tube is preferably comprised of copper tubing or similar composition of copper with the fuel member comprised of a plastic material thereby forming a chemical reaction when heated thereby displaying a pleasing variety of colors within a fire. The outer tube may include a first cap and a second cap for preventing the fuel member from exiting the outer tube.

1. Field of the Invention
The present invention relates generally to fire enhancement products for campfires and fireplaces, and more specifically it relates to a fire enhancement system for increasing the visual appearance of a fire with a simple to utilize structure.
Fires are commonly utilized by individuals to provide warmth and sometimes merely for aesthetic reasons. Wood fires typically display white, red and orange colors within their flames. It is desirable to increase the visual appearance of these fires to provide an increased aesthetic appearance.
2. Description of the Prior Art
Fire enhancement devices have been in use for years. Typically, an "artificial log" is comprised of wood material along with various chemicals to decrease the amount of time to ignite a fire. Some fire enhancement products add a scent to the fire to make the scent of the fire pleasing to individuals adjacent the fire.
Examples of patented fire enhancement devices include U.S. Pat. No. 3,370,932 to Kelly et al.; U.S. Pat. No. 2,398,571 to Young; U.S. Pat. No. 4,309,189 to Oberhardt; U.S. Pat. No. 4,997,457 to Mitsusawa et al.; U.S. Pat. No. 4,062,655 to Brockbank; U.S. Pat. No. 2,373,512 to Starner which are all illustrative of such prior art. The disclosures and content of these patents are hereby incorporated by reference regarding the present patent application.
While these devices may be suitable for the particular purpose to which they address, they are not as suitable for increasing the visual appearance of a fire with a simple to utilize structure. Conventional products on the market do not increase the visual appearance of the fire. Patented inventions do not provide an easy self-contained structure to utilize to increase the visual appearance of the fire.
In these respects, the fire enhancement system according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of increasing the visual appearance of a fire with a simple to utilize structure.


Disclosed and claimed are DNA gene segments, biologically functional plasmids and recombinant plasmids, and microorganism host cells containing such plasmids, all of which contain toluene monooxygenase genes from Pseudomonas mendocina KR-1 and which are useful in a method for the microbial bioconversion of selected phenyl compounds to selected phenolic compounds. In particular, the method is useful for making p-hydroxyphenylacetic acid which is a valuable chemical intermediate in the preparation of certain antibiotics and certain .beta.-adrenergic blocking agents.

The present invention is directed to the use of recombinant DNA techniques to confer upon microorganism host cells the capacity for selected bioconversions. More specifically, the invention is directed to the cloning of toluene monooxygenase genes from a newly isolated and characterized Pseudomonas strain, Pseudomonas mendocina KR-1. The present invention thus provides genetically engineered microorganisms that over produce toluene monooxygenase enzymes and proteins, and therefore provides more efficient means of conducting bioconversions dependent on this enzyme system.
Recently, a bacterium identified as Pseudomonas mendocina KR-1 (PmKR1) was isolated by Richardson and Gibson from an algal-mat taken from a fresh water lake. Whited, Ph. D. Dissertation, The University of Texas at Austin, Library Reference No. W586 (1986). PmKR1 utilizes toluene as a sole carbon and energy source. Other strains of Pseudomonas have been previously isolated and described which metabolize or degrade toluene, including Pseudomonas putida mt-2 (Pp mt-2). Williams and Murry, J. Bacteriol. 120: 416-423 (1974) and Pseudomonas putida PpF1 (PpF1) (Gibson, et al. Biochemistry 9:1626-1630 (1970). However, the genes, the enzymes and the pathways for toluene metabolism in these various Pseudomonas strains are distinct and non-overlapping.
The catabolic pathway for the degradation of toluene by Pp mt-2 has been designated TOL. The genes for the TOL pathway are encoded on isofunctional catabolic plasmids found in certain strains of Pseudomonas. The reference plasmid for the TOL degradative pathway is pWWO originally isolated from Pp mt-2. The genetics and biochemistry of the TOL pathway are well described. Kunz and Chapman, J. Bacteriol. 146:179-191 (1981); Williams and Murry, J. Bacteriol. 120:416-423 (1974); Williams and Worsey, J. Bacteriol. 125:818-828 (1976); Worsey and Williams, J. Bacteriol. 124:7-13 (1975); Murry, et al., Eur. J. Biochem. 28:301-310 (1972). A brief summary of the TOL pathway is as follows: initial attack of toluene is at the methyl group which undergoes successive oxidations to form benzoic acid, which is further oxidized by formation of a cis-carboxylic acid diol, which is oxidized to form catechol, which is then degraded by enzymes of a meta cleavage pathway to acetaldehyde and pyruvate.
A second catabolic pathway for the degradation of toluene by PpF1 has been established and designated TOD. In contrast to the TOL pathway, the genes for the TOD pathway are located on the bacterial chromosome and are not plasmid-encoded. Finette, et al., J. Bacteriol. 160:1003-1009 (1984); Finette, Ph. D. Dissertation, The University of Texas at Austin, Library Reference No. F494 (1984). The genetics and biochemistry of the TOD pathway has been studied by Finette, et al. (supra); Finette (supra); Gibson, et al. Biochemistry 9:1626-1630 (1970); Kobal, et al., J. Am. Chem. Soc. 95:4420-4421 (1973); Ziffer, et al., J. Am. Chem. Soc. 95:4048-4049 (1973); Dagley, et al., Nature 202:775-778 (1964); Gibson, et al., Biochemistry 7:2653-2662 (1968). A brief summary of the TOD pathway is as follows: the initial attack of toluene is by a dioxygenase enzyme system to form (+)-cis-1(S),2(R)-dihydroxy-3-methylcyclohexa-3,5-diene(cis-toluene dihydrodiol) which is oxidized to 3-methylcatechol which is further degraded by enzymes of a meta cleavage pathway.
A third catabolic pathway for the degradation of toluene has been recently identified in PmKR1. It has been found that PmKR1 catabolizes toluene by a novel pathway which is completely different than either of the two pathways described above. Richardson and Gibson, Abst. Ann. Meet. Am. Soc. Microbiol. K54:156 (1984). The catabolic pathway for the degradation of toluene by PmKR1 has been designated TMO, because the first step in the pathway is catalyzed by a unique enzyme complex, toluene monooxygenase. The biochemistry of the enzymes and proteins of this pathway has been recently studied in detail by Whited, Ph. D. Dissertation, The University of Texas at Austin, Library Reference No. W586 (1986).
A brief summary of the TMO pathway in PMKR1 is as follows: in the initial step toluene is oxidized to p-cresol, followed by methyl group oxidation to form p-hydroxybenzoate, followed by hydroxylation to protocatechuate and subsequent ortho ring cleavage. The steps of the TMO pathway as outlined by Whited (supra) are diagrammed in FIG. 1. In the first step of the TMO pathway, toluene is converted by toluene monooxygenase to p-cresol. PmKR1 elaborates a unique multicomponent enzyme system which catalyzes this first step monooxygenase reaction. According to Whited, (supra), at least three protein components are involved: oxygenase (at least 2 subunits of 50,000 d. and 32,000 d.), ferredoxin (23,000 d.) and NADH oxidoreductase (molecular weight unknown).
At present, despite the substantial advances in the understanding of the biochemistry of the enzymes and proteins of the TMO pathway and beginning genetic studies (Yen et al. Abstract, University of Geneva EMBO Workshop, Aug. 31-Sept. 4, 1986), the art has not been provided with information regarding the genes encoding the enzymes and proteins of the toluene monooxygenase system in PmKR1 or the usefulness of such genes and gene products in certain microbial bioconversions. The art has also not been provided with microorganism host cells containing novel recombinant plasmids containing PmKR1 toluene monooxygenase genes, in which certain of these microorganism host cells express toluene monooxygenase enzyme activity at levels that exceed the activity of wildtype PmKR1 cells.

Plasmid encoding the Pseudomonas mendocina toluene monooxygenase gene


A retainer employs a flexible arm with an internal rib. In another aspect of the present invention, a retainer has at least one generally triangularly shaped projection laterally extending from an arm. A further aspect of the present invention retainer provides a laterally enlarged member, a trim panel-retaining head and stem, a central post, one or more flexible wings flexibly spanning between a tip of the post and the laterally enlarged member, and an internal rib and/or at least a pair of generally angular extensions flexibly extending from each arm.

The present application relates generally to fasteners and more particularly to an automotive vehicle trim retainer.
Conventional polymeric fasteners have been used in the automotive industry to retain interior trim panels to sheet metal structure. Examples of such traditional fasteners are disclosed in the following U.S. Pat. No.; 5,592,719 entitled "Fastening Clip" which issued to Eto et al. on Jan. 14, 1997; U.S. Pat. No. 5,573,362 entitled "Fastener Including Elastic Legs for Retaining the Fastener in a Mounting Hole" which issued to Asami et al. on Nov. 12, 1996; and U.S. Pat. No. 5,301,396 entitled "Fastener Assembly with Compression Member" which issued to Benoit on Apr. 12, 1994; all of which are incorporated by reference herein. Known fasteners such as these have unsuccessfully attempted to provide desirable insertion versus extraction forces while also achieving self-centering and over-compression resistance. Moreover, many conventional polymeric fasteners are not acceptably reusable after removal from the often sharp, sheet metal hole edges.


A method is for correcting an imbalance in a computed tomography system, in which a supporting structure includes a radiation source is fitted on a fixed mounting frame. The supporting structure rotates together with the radiation source about a measurement space, in which is fixed in place a measurement object having a known attenuation response for the radiation emitted by the radiation source. The method includes detecting first measurement data of the radiation while the supporting structure rotates about the measurement object, determining an imbalance arising during the rotation of the supporting structure on the basis of the acquired first measurement data of the radiation, and determining a position and a weight of at least one counterweight on the supporting structure in order to reduce the determined imbalance, or determining correction data, which is used to correct the imbalance in software.

In all rotating or rotational computed tomography systems there are dynamic effects that arise as a result of imbalances in the rotating components. These imbalances can be so severe that they affect the operating life of the components. In addition, they can have a negative impact on the operation of the various components or on the image quality.
Until now, the imbalances in a rotating supporting structure (also known as a gantry) comprising the radiation source were handled in various ways:
At low speeds of rotation, and if there is no negative impact on the operation or the operating life of the rotating parts, no balancing of the rotating parts takes place.
The components to be mounted on the rotating plate are checked individually to ascertain whether the weight, the center of gravity, and the position of this center of gravity lie within a specified tolerance. This tolerance has been established in advance in order to determine when the imbalance has negative consequences. An initial counterbalancing of the imbalance is performed using counterweights, which offset the imbalances.
For systems in which the speed of rotation of the gantry is higher, the residual imbalances are detected, for instance using sensors or mechanical measurement device(s). Then the counterweights are mounted on one plane or two separate planes according to the information from the sensors, which involves determining the plane and angular position of the counterweight.
The aforementioned procedure is performed once or repeatedly during the manufacture of the computed tomography system until a desired result is achieved. This procedure, however, is also performed on some systems installed at the end-user's premises, for instance performed by service personnel when replacing components. For this purpose, the sensors or other measurement device(s) are permanently installed in the system, or the service personnel must bring external measurement device(s) with them.
In addition, the service personnel require counterweights on site. Thus correcting imbalances is time-consuming, especially in operation.

Correcting an imbalance on the basis of the acquired radiation data


An amorphous substance obtained by mixing volcanic ash with or without added clay and water and, if necessary, a surfactant, kneading the mixture, and shaping and firing. Additives such as camphor or naphthalene may be included prior to firing for plasticity and to form pores. The resultant mixture possesses an ability to adsorb phosphorus selectively. When this substance is placed in contact with a phosphorus-containing liquid, it removes phosphorus from the liquid.

1. Field of the Invention
This invention relates to a novel adsorbent for phosphorus, a method for the dephosphorization of a phosphorus-containing liquid, and a method for the production of the adsorbent for phosphorus. More particularly, this invention relates to an adsorbent for phosphorus which essentially consists of a fired shaped product of volcanic ash possessing outstanding characteristics such as preferential adsorption of phosphorus, a large capacity for adsorption of phosphorus, excellent selectivity with respect to phosphorus, high durability and inexpensiveness, a method for dephosphorization by the use of the adsorbent mentioned above, and a method for the production of the adsorbent. The adsorbent is advantageously used for the removal of phosphorus from sewage, for example.
2. Prior Art Statement
In recent years, environmental pollution due to the eutrophication of rivers and lakes has become a serious problem. As countermeasures, use of phosphorus-free detergents in the home and treatment of sewage for dephosphorization have been promoted.
The removal of phosphorus from sewage has heretofore been performed mainly by secondary treatment attendant on the treatment of activated sludge using a microorganism. The known methods available for the secondary treatment include the lime process, the method using a metal salt such as an aluminum salt, and the method using an ion-exchange resin, for example (Kagaku Kogyosha: "Extra Issue of Kagaku Kogyo", Vol. 18 No. 1, pp 210-219, published on Jan. 1, 1974).
In the treatment by any of these methods, the ratio of phosphorus removed to the total phosphorus contained in the sewage falls short of 30%. Sewage still retaining the greater part of its original phosphorus content is released into rivers. These processes pose a number of problems. The lime process, for example, is a method which effects the removal of phosphorus by adding to the phosphorus-containing sewage under treatment an amount of lime large enough to adjust the pH value of the resultant mixture to about 10 thereby inducing occurrence of floc containing phosphorus and removing the floc from the sewage. This process entails the disadvantage that the neutralization of the sewage remaining after the removal of phosphorus necessitates consumption of a large amount of carbon dioxide, the treatment requires much time and labor, and the equipment for the treatment is expensive. The method relying on the use of a metal salt such as an aluminum salt entails the disadvantage that the gelled product obtained by the reaction with phosphorus requires a very difficult treatment. The method using an ion-exchange resin has very small selectivity with respect to phosphorus and normally suffers degradation in phosphorus removal capacity and efficiency in the presence of other coexisting cations or anions. Thus, the conventional techniques for the removal of phosphorus have a number of problems. A solution of these problems is urgently needed.

Adsorbent for phosphorus and method for production of adsorbent for phosphorus

Agency of Industrial Science and Technology

Ministry of International Trade and Industry


A system and associated method is disclosed to monitor physiological activity of a subject. One or more sensors are positioned in or on a support, the support being adapted to receive the subject, at least a first one of the sensors being adapted to produce a first signal indicative of movement of the subject over time. Processing apparatus is adapted to identify first, second and third portions of the first signal. The first and third portions correspond to first and third time periods, respectively, during which the subject changes body position on the support. The second portion corresponds to a second time period, between the first and third time periods, during which substantially no change in body position of the subject on the support takes place.

Many devices have been used and proposed for recording breathing or sleep activity. One example is an ECG measurement system in which ECG electrodes are attached to a subject's skin. Another example is an electronic stethoscope which is manually pressed against the subject to hold it in place against the subject's skin.
An alternative approach employs vibration sensors that are placed at different positions in a mat. The sensors are configured to sense vibrations from the patient, permitting diagnosis of breathing abnormalities, snoring and sleep apnea, etc. The sensors are distributed over the mat such that, when the subject rests against the mat, sensors may sense sound vibrations originating from the subject to enable a diagnosis to be performed.
Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application.

System and method for monitoring physiological activity of a subject


Provided is a host computer which is connected to a system resource through n (n≧2) number of paths. The host computer includes: a plurality of logical partitions accessible to the system resource; an allocation unit that allocates the paths to the plurality of logical partitions; and an allocation table. The allocation table is user configurable and stores, in a correlated manner, information indicating the logical partitions and information capable of indicating the number of paths to be allocated to the logical partitions indicated by the information. The allocation unit allocates the paths to the logical partitions in accordance with the allocation table. This makes it possible to secure the I/O response also for logical partitions having a small amount of I/O.

1. Technical Field
The present invention relates to a path allocation technique for use in a multipath system.
2. Background Art
Various attempts have been made to improve the efficiency of computer systems that include a host computer and a system resource (e.g., storage device) used by the host computer.
For example, Japanese Unexamined Patent Application Publication No. 2008-257572 discloses a method for creating multiple logical partitions by logically partitioning storage devices, controlling the logical partitions so that each logical partition separately operates as an independent storage system, and changing the proportion allocated to each logical partition according to the amount of access from a host computer. With this method, the resource of a storage device, which is owned by a logical partition having a small amount of access, can be allocated to a logical partition having a large amount of access. As a result, the storage resource can be effectively used.
There has also been known a multipath system in which a host computer and a system resource are connected through multiple paths. According to the multipath system, path redundancy or distribution of an input/output (I/O) load is realized. Various methods for the construction and operation of such a multipath system have been proposed.
For example, Published Japanese Translation of PCT International Publication for Patent Application, No. 2002-533831 discloses a method for a multipath system employing multiple paths simultaneously. The method has been devised for allocating I/O operations for transmission/reception between a host computer and a system resource to any of the multiple paths. Specifically, according to this method, a time to complete the I/O operation currently being performed by each path is predicted, and a next I/O operation is allocated to the path which is expected to complete the I/O operation most quickly. This makes it possible to improve the usability of multiple paths and increase the efficiency of the entire system compared with the conventional round robin technique in which I/O operations are sequentially allocated to multiple paths.
Additionally, Japanese Unexamined Patent Application Publication No. 2007-157089 discloses a method for a multipath system including a path (regular path) for ordinary use and a path (sub path) used when a failure occurs in the regular path. According to the method, when a failure is detected in the regular path, the regular path is switched to the sub path and the regular path is blocked until the failure in the regular path is resolved.
If the regular path is not blocked during the time when a failure occurs in the regular path, the access from a host computer to a storage device is executed by the following procedure. That is, "the host computer accesses via the regular path", "the host computer cannot access the storage device because a failure occurs in the regular path", and "the regular path is switched to the sub path". According to the method disclosed in Japanese Unexamined Patent Application Publication No. 2007-157089, the failed regular path is blocked until the regular path is restored, and thus the host computer constantly "accesses the system resource via the sub path" during this period. This can improve the access efficiency during the period when a failure occurs in the regular path.
Moreover, there has also been known a multipath system in which a host computer having multiple logical partitions, which are configured for each of multiple operating systems (OSs), and a system resource are connected through multiple paths, and in which the multiple logical partitions share the system resource.
In the multipath system in which the host computer having multiple logical partitions and the system resource are connected through the multiple paths and in which the multiple logical partitions share the system resource, there is a fear that, when the multiple logical partitions have various amounts of I/O, processing in response to requests from logical partitions having a large amount of I/O accounts for a large portion of the processing of the entire system, and application processing in logical partitions having a small amount of I/O may be hindered.

Host computer, multipath system, path allocation method, and program


Methods for attenuating multiple reflections in seismic data by predicting the multiples using wavefield extrapolation modeling, which uses one-way wavefield propagation in both the up and down directions to predict internal multiples up to a specified order.

1. Field of the Invention
Embodiments of the present invention generally relate to seismic surveying and, more particularly, to a method for attenuating multiples in seismic data.
2. Description of the Related Art
The following descriptions and examples do not constitute an admission as prior art by virtue of their inclusion within this section.
Seismic surveying is a method for determining the structure of subterranean formations in the earth. Seismic surveying may typically utilize seismic energy sources which generate seismic waves and seismic receivers which detect seismic waves. The seismic waves may propagate into the formations in the earth, where a portion of the waves may reflect from interfaces between subterranean formations. The seismic receivers may detect the reflected seismic waves and convert the reflected waves into representative electrical data. The seismic data may be transmitted by electrical, optical, radio or other means to devices which record the data. Through analysis of the recorded seismic data (or seismograms), the shape, position and composition of the subterranean formations may be determined. Such analysis may indicate the presence or absence of probable locations of hydrocarbon deposits or other valuable substances.
Depending on the location where a survey takes place, there are surveys in sea, on land or in transition zones. Marine seismic surveying is a method for determining the structure of subterranean formations underlying bodies of water. Marine seismic surveying may typically utilize seismic energy sources and seismic receivers located in the water which may be either towed behind a vessel or positioned on the water bottom from a vessel. The energy source may typically be an explosive device or compressed air system which generates seismic energy, which then propagates as seismic waves through the body of water and into the earth formations below the bottom of the water. As the seismic waves strike interfaces between subterranean formations, a portion of the seismic waves may reflect back through the earth and water to the seismic receivers, to be detected, transmitted, and recorded. The seismic receivers typically used in marine seismic surveying may be pressure sensors, such as hydrophones. Additionally, motion sensors, such as accelerometers, may be used. Both the sources and receivers may be strategically repositioned to cover the survey area.
Land seismic surveying is done on land. The energy sources are typically vibratory sources (vibrators). The vibrators produce a pressure signal that propagates through the earth into the various subsurface layers. Here elastic waves are formed through interaction with the geologic structure in the subsurface layers. Elastic waves are characterized by a change in local stress in the subsurface layers and a particle displacement, which is essentially in the same plane as the wavefront. Acoustic and elastic waves are also known as pressure and shear waves. Acoustic and elastic waves are collectively referred to as the seismic wavefield.
A reflected wavefield may consist of both primary reflections and multiple reflections. Primary reflections may be defined as seismic waves which have reflected only once, from an interface between subterranean formations, before being detected by a seismic receiver. Primary reflections contain the desired information about the subterranean formations which is the goal of marine seismic surveying. Multiple reflections, or multiples, may be defined as seismic waves which have reflected more than once before being detected by a seismic receiver.
FIG. 1 illustrates two types of multiples: internal multiple 110 and a surface multiple 120. A "surface multiple" is herein defined as any seismic event that is generated by at least two upward reflections and at least one downward reflection from the free surface boundary. The free surface boundary is typically the sea surface in marine environment, or earth surface in land surveys.
Another type of multiples is an "internal multiple", which is herein defined as any seismic event that is generated by at least two upward reflections and at least one downward reflection from a boundary below the free surface with no downward reflection from the free surface. The internal multiples comprise multiple reflections between reflectors and media within the earth subsurface, whose physical properties are unknown and usually need to be determined by the survey.
In the context of seismic surveying, multiple attenuation is a pre-stack inversion of a recorded wavefield, which aims at removing the energy associated with multiple reflections. Theoretically, multiple attenuation can be pursued in a totally data-driven manner by evaluating equations which involve continuous summations over the directions of space.
Surface Multiples
There are several methods available to attenuate surface related multiples. Wavefield extrapolation techniques that estimate surface multiples have been described in many publications. Wiggins (1999) summarized the 2D technique that subtracts forward extrapolated shot gathers from backward extrapolated shot gathers. In this case, the primaries of the forward extrapolated shots matched the first order surface multiples of the backward extrapolated shots. Subtracting these data sets and forward extrapolating the results removed the first order surface multiples from the input shot gathers.
Kabir et. al. (2004) extended Wiggins' method to 3D and used it to attenuate water-bottom multiples and peg-legs. But this method required receiver line interpolation to ensure adequate crossline data coverage.
Pica et. al. (2005) extended the 3D wavefield extrapolation technique to essentially de-migrate a depth image using a given velocity field to compute primaries and surface multiples. The first de-migration process resulted in an estimate of the primaries, and subsequent de-migrations computed successively higher orders of surface multiples. They indicated that a recorded shot can be used in place of the computed primary wavefield.
Stork et. al. (2006) used a similar de-migration scheme to compute primaries and surface multiples. This method is called Wavefield Extrapolation Multiple Modeling (WEMM), and performs the following four steps. FIGS. 6-9 illustrate the steps and a four-layer model 600, which has three interfaces 611, 612 and 613, and a bottom 614.
Step 1: Using wavefield extrapolation, forward propagate a point source 620 at the source location (S, considered the surface) downward through the given reflectivity and velocity models 600, and compute and store upward reflection information (a 628, b 627 and c 626 in FIG. 6). Stop the propagation at a specified depth (bottom 614).
Step 2: Forward propagate a 2D zero energy wavefield from the bottom 614 of the given reflectivity and velocity models 600 to the surface 610, and accumulate all upward reflection information previously computed (c′ 636, b′ 637 and a′ 638 in FIG. 7). Save the 2D wavefield at the surface 610. This wavefield consists of primary reflections generated from one upward bounce off of the modeled reflectors 611, 612 and 613.
Step 3: Forward propagate the recorded 2D wavefield at the surface downward through the given reflectivity and velocity models 600, and again compute and store upward reflection information (d 648, e 647 and f 646 in FIG. 8). Stop the propagation at the bottom 614.
Step 4: Forward propagate a 2D zero energy wavefield from the bottom 614 of the given reflectivity and velocity models 600 to the surface 610, and accumulate all upward reflection information previously computed (d′ 658, e′ 657 and f′ 656 in FIG. 9). Save the wavefield at the surface 610. This wavefield consists of first order surface multiples generated from two upward reflections off of the modeled reflectors and one downward bounce off of the free surface 610.
Higher orders of surface multiples can be computed by increasing the number of propagations performed. Surface multiples of order 1 to N−1 are computed from N propagations.
Internal Multiple Prediction
Pica and Delmas (2008) used a wavefield extrapolation method similar to the surface multiple prediction method described by Pica et. al. (2005) to compute 3D internal multiples from marine data. Their method consists of four separate extrapolation steps.
Step 1: Back propagate recorded shots to an arbitrary depth.
Step 2: Upward propagate the back propagated shot through the migrated image to generate a first set of secondary sources at reflectors.
Step 3: Propagate the wavefield generated from first set of secondary sources downward through migrated image, building a second set of secondary sources at the reflectors.
Step 4: Propagate the wavefield generated from the second set of secondary sources upward through migrated image, resulting in an internal multiple model.
This method of internal multiple modeling inputs recorded shots as the initial wavefield, and adds to all events in the shot of first order internal multiple whose generating horizon lies above the arbitrary depth established in Step 1.
As described above, the prior art methods have some success in predicting and attenuating multiples. But it is still not satisfactory for many situations. Internal multiples are still difficult and costly to remove from seismic data, especially as the dimension for the problem increases. It is desirable to have methods to effectively attenuate various multiples, especially internal multiples.

Wavefield extrapolation modeling for internal multiple prediction