Abstract: An image forming medium is provided which has an image forming layer comprising a monomolecular film of a diacetylene derivative compound or its built-up film and a radiation absorbing layer. The diacetylene derivative compound may be polymeric. An image forming device employing the image forming medium is also provided.

Abstract: A photosensitive recording material for recording information by means of a local change in the optical properties of a recording layer under the action of light having a high energy density, and a process for its preparation.

Abstract: The photoconductive layer of an electrophotographic plate, such as used to record radiographic patterns, is overcoated with a thin dielectric layer having luminescing (e.g., fluorescing or phosphorescing) properties. Upon being uniformly charged and imagewise exposed to actinic radiation (i.e. radiation to which the photoconductive layer responds), the resulting charge pattern is developed with toner. The toner-bearing surface of the electrophotographic plate is irradiated with radiation adapted to excite the luminescent overcoat. The toner image serves, in effect, to mask any luminescence by the underlying overcoat, thereby giving rise to a luminescent contrast image which may be recovered by laser scanning or CCD techniques, or photographed directly.

Abstract: There is provided a process for preparing a film positive sheet for a forging-by-copying-proof print in which a first background image sheet is placed on a first latent image sheet, an unexposed film having a photosensitive membrane on the undersurface is placed on the background sheet to provide a primary three-layer film structure, the three-layer film structure is illuminated to partially expose the film, the first latent image and background sheets are replaced by second latent image and second background sheets, respectively, to provide a secondary three-layer film structure, the secondary three-layer film structure is illuminated to completely expose the partially exposed film and the second latent image and background sheets are removed from the secondary three-layer structure to thereby provide a film positive sheet for a forging-by-copying-proof print. Then, a forging-by-copying-proof print is prepared from the film positive sheet by a printing method such as offset or relief printing.

Abstract: A photosensitive recording material for recording information by means of a local change in the optical properties of a recording layer under the action of light having a high energy density, and a process for its preparation.

Abstract: A high contrast developing process is described for use after pre-exposure to UV-visible radiation to produce increased sensitivity during lithographic processing of positive resist layers. Compared to samples which have not been subjected to the methods of this invention, sensitivity increases of a factor of 2-4 are to be expected. An additional benefit of low film loss from unexposed resist is obtained. The system disclosed is applicable to lithographic exposures utilizing electrons, photon (e.g. UV-visible, x-rays, etc.) and atomic or molecular charged particles. Specifically, as a result of the increased sensitivity, higher throughput during lithographic processing for the fabrication of photomasks and semiconductor devices is realized.

Abstract: An information recording medium comprises a pair of substrates provided on at least one substrate thereof with a recording layer containing an organic coloring matter, and stuck together by use of an adhesive in such a manner that the substrates may be disposed with the interposition of a space, wherein said substrates of the information recording medium are stuck together by use of an adhesive containing an epoxy monomer and a compound capable of generating a Lewis acid by irradiation with light, and a process for producing the information recording medium.

Abstract: A relief flexographic printing plate is prepared by image-wise exposure of the "printing face" of a layer of photocurable polymer through a negative 7 and image-wise back exposure of the layer 4 through a support sheet 3 and a positive 6 of the image to be printed, thereby selectively curing the floor regions 9 of the printing plate in register with the uncured areas 8 left in the printing face of said layer.Preferably a further non-selective back exposure operation is carried out for additionally curing the floor regions.

Abstract: An optical recording-reproducing method comprising the step of irradiating a radiation for polymerization on an optical recording medium having a recording layer containing at least one selected from the group consisting of azulenium salt compounds, pyrylium dyes, diene compounds, croconic methine dyes and polymethine compounds (hereinafter called the group B) and a diacetylene derivative compound; the step of irradiating a radiation corresponding to a recording information to thereby change the color at the irradiated portion of the recording layer; and the step of reading the recorded information by irradiating a reading light with a shorter wavelength than said radiation on said recording layer. Also, an optical recording-reproducing device utilizes the above-mentioned method.

Abstract: An area on a photoresist film which is formed on a substrate surface having a topography, is exposed a plurality of times in such a manner that the image plane of a mask pattern is formed at a plurality of positions which are spaced apart from a reference plane in the substrate in the direction of an optical axis, and then the photoresist film is developed to form a resist pattern. According to the above method, the effective focal depth of the projection aligner used is enhanced, and moreover the reduction of the image contrast at the photoresist film is made very small by the plural exposure operations. Accordingly, a fine pattern can be formed accurately on the substrate surface having the topography.

Abstract: Paste-consistency photopolymer is imaged onto printed wiring boards by coating the board overall and positioning the photographic film over the board in register and off-contact. A resilient blade is pressed against the phototool at one end of the board and drawn across the surface, thus forcing the photographic film into intimate contact with the photopolymer and purging all air therebetween. Mounted on the resilient blade aft of leading edge is a shuttered tubular lamp which hardens the photopolymer where the photographic film is clear, so that in a single pass the photographic film is sequentially mated and photopolymer exposed, to produce line widths unmatched by competing dry film systems and at speeds of 0.5 feet per second.

Abstract: An area on a photoresist film which is formed on a substrate surface having a topography, is exposed a plurality of times in such a manner that the image plane of a mask pattern is formed at a plurality of positions which are spaced apart from a reference plane in the substrate in the direction of an optical axis, and then the photoresist film is developed to form a resist pattern. According to the above method, the effective focal depth of the projection aligner used is enhanced, and moreover the reduction of the image contrast at the photoresist film is very small by the plural exposure operations. Accordingly, a fine pattern can be formed accurately on the substrate surface having the topography.

Abstract: A printing cylinder or a sleeve is coated with a continuous photosensitive recording layer by applying a first jointless stratum of a photosensitive recording layer to the printing cylinder or the sleeve, and uniformly preexposing this first stratum to actinic light and thereafter applying one or more further jointless strata of the photosensitive recording layer to this preexposed first stratum.

Abstract: A process for the production of a heat-sensitive recording material in which a color former causing a color formation reaction and a developer forming color on reaction with the color former are incorporated in a heat-sensitive recording layer, and at least one of the color former and the developer is contained in microcapsules having walls which are impermeable to both the color former and the developer at ordinary temperature but which becomes permeable to at least one of the color former and the developer on heating, where the heat-sensitive recording layer is coated on a support which is then subjected to surface treatment by passing it through a pressure applying apparatus comprising a metallic roll and an elastic roll in such a manner that the heat-sensitive recording layer is in contact with the metallic roll.

Abstract: An infrared flash unit, for use with camera employing infrared film, is mounted in a housing having a base configured to fit on the normal flash unit attachment of a standard camera. The housing has a front panel with an array of eight individual reflectors, each having an infrared light emitting diode or laser diode in it. A power supply is connected through a pulse driver circuit to the diodes, each of which are connected in series with a corresponding switch. The diode and switch combination are connected in parallel with one another and in series with the pulse driver circuit. Different combinations of diodes are selected for operation in accordance with the shutter speed and range of the camera. The pulse driver circuit supplies energizing pulses to the selected diodes at a repetition rate and duty cycle selected to match the primary infrared wave length of the diodes and the film used in the camera to reduce fogging due to background infrared light.

Abstract: A silver halide photographic light-sensitive material and a process for processing it are disclosed. The light-sensitive material is improved in photographic sensitivity, drying property and anti-roller-mark property and is suitable for the disclosed ultra-rapid processing by an automatic processor in which the photographic material is processed for the time of 20 sec to 60 sec in total. The light-sensitive material comprises a support having on at least one side thereof one or more hydrophilic layers containing gelatin which comprise at least one light-sensitive silver halide emulsion layer. An amount of the gelatin contained in said hydrophilic layer or layers is within the range of from 1.90 to 3.50 g/m.sup.2 and a swelling amount of said hydrophilic layer or layers is within the range of from 30 to 58 g/m.sup.2 when said light-sensitive material is treated in a specific condition for 15 sec. at 35.degree. C.

Abstract: A process for the formation of an image comprises(i) applying to a substrate a layer of a liquid composition comprising(A) a residue which is cationically polymerizable or polymerizable by means of free radicals,(B) a radiation-activated polymerization initiator for (A) and(C) a radiation-solubilizable residue,(ii) subjecting the composition to radiation having a wavelength at which (B) is activated but at which (C) is not substantially activated, optionally followed by heating, thereby polymerizing (A) such that the layer of liquid composition is solidified,(iii) subjecting the solidified layer in a predetermined pattern to radiation having a wavelength which is different from that of the radiation used in stage (ii) and at which the residue (C) is activated, such that the solidified layer is rendered more soluble in a developer in exposed areas than in unexposed areas, and(iv) removing the exposed areas by treatment with a developer.

Abstract: The invention provides a process for the production of an image which comprises(i) applying to a substrate a layer of a liquid composition comprising(A) a cationically polymerizable residue(B) a radiation-activated polymerization initator for (A)(C) a radiation-curable residue that is different from (A) and optionally(D) a radiation activated initiator for the cure of (C),(ii) subjecting the composition to actinic radiation having a wavelength at which initiator (B) is activated but at which the residue (C) and/or initiator (D) is not substantially activated, followed by heating, if necessary, so that (A) is polymerized and the layer of liquid composition is solidified, but remains curable,(iii) subjecting the solidified layer in a predetermined pattern to actinic radiation having a wavelength that is different from that of the radiation used in stage (ii) and at which the radiation-curable residue (C) and/or the initiator (D) is activated, such that in the exposed areas (C) is substantially cured, and(iv) re

Abstract: Indicia, provided on a specularly reflective surface, are formed by a dot surface relief pattern featuring polygonal surfaces spaced apart to enhance scattering. The spacing of dots is characterized by a pitch in the range of 8 to 50 microns with a dot size of less than 50 microns and usually about one-half of the pitch dimension. In one embodiment, the dots may be anisotropically etched forming mesas, enhanced by gemlike polygonal facets which provide good optical contrast relative to the background surface.

Abstract: An electrophotographic method is disclosed, in which electrostatic latent images are formed on an electrophotographic photoconductor by exposure of the photoconductor to a light beam, and the formed electrostatic latent images are developed to visible toner images by a developer comprising toner particles, with the minimum diameter D of the light spot of the light beam on the photoconductor and the volume mean diameter X.sub.w of the toner particles being in the relationship of (D).mu.m.gtoreq.9.0.times.(X.sub.w).mu.m-34.

Abstract: Process of photoetching of superficial coatings based on polymeric material comprising the irradiation of the coated surface with localized excimer laser beams having wavelengths equal to or lower than 193 nm.

Abstract: A silver halide negative photographic material is described, comprising a support, at least one silver halide emulsion layer, and one or more light-insensitive hydrophilic colloid layers, wherein said silver halide emulsion layer or said light-insensitive hydrophilic colloid layer contains a hydrazine derivative, and the photographic material has a film surface pH not higher than 5.8 on the side of said emulsion layer inclusive of said light-insensitive hydrophilic colloid layer; in another aspect, this invention is directed to a method for forming an ultrahigh contrast negative image, comprising exposing said photographic material imagewise, followed by development processing of the same with a developer containing at least 0.15 mol/liter of sulfite ion and having a pH of from 10.5 to 12.3.

Abstract: A medium for image formation which comprises a monomolecular film or monomolecular built-up film of a metal chelate compound and a process for image formation which comprises (1) manipulating the adsorption of a gas on a metal chelate compound and the desorption of the gas therefrom or (2) reducing metal ions in molecules of a metal chelate compound.

Abstract: The present invention provides a method for reducing short time-scale reciprocity failure effects of a photosensitive imaging sheet. The photosensitive imaging sheet comprises a substrate having a layer of microcapsules on one surface thereof. The microcapsules contain an internal phase of an acrylate monomer, photoinitiator, and color former. A portion of the microcapsules of the imaging sheet is image-wise exposed to high intensity light and then allowed to recover from the exposure. The exposure and recovery steps are repeated to form a latent image. By pulsing the light onto the photosensitive imaging sheet, the total exposure energy required per unit area is significantly reduced compared to the known short time-scale exposure method.

Abstract: There is provided a process for preparing a film positive sheet for a forging-by-copying-proof print in which a first background image sheet is placed on a first latent image sheet, an unexposed film having a photosensitive membrane on the undersurface is placed on the background sheet to provide a primary three-layer film structure, the three-layer film structure is illuminated to partially expose the film, the first latent image and background sheets are replaced by second latent image and second background sheets, respectively, to provide a secondary three-layer film structure, the secondary three-layer film structure is illuminated to completely expose the partially exposed film and the second latent image and background sheets are removed from the secondary three-layer structure to thereby provide a film positive sheet for a forging-by-copying-proof print.

Abstract: On a photosensitive lacquer present on a substrate, details having a line width in the range of 0.5 .mu.m-2 .mu.m have to be accurately reproduced in the lacquer layer. In order to determine the exposure does or time, the lacquer layer is exposed through a raster pattern comprising alternately transparent and non-transparent line-shaped regions of the desired width. The raster pattern is then laterally displaced over a distance equal to the line width in a direction at right angles to the longitudinal direction of the lines, after which an exposure is carried out again at the same dose. The process is repeated at a few areas, but at a different exposure dose, after which a reference exposure dose is determined in that it is ascertained what dose is required to just dissolve entirely the photosensitive lacquer layer after development.

Abstract: Disclosed is a direct making of multicolor printing plates by the procedure of exposing a photosensitive material (P) of the lithographic type for making a black plate to an original bearing both the continuous tone image and the line images. The said procedure comprises (1) exposure to the continuous tone image which is performed by exposing the sensitive material (P) through a contact screen to the original in which the line images are covered with a mask (M-1) having an optical reflectance of 2% or less and the continuous tone image is covered with a mask (M-2) having a large optical reflectance, then again exposing, in the absence of contact screen, the sensitive material (P) to the original in which the line images are covered with said mask (M-1), and the mask (M-2) for the continuous tone image is removed, and (2) exposure to the line images which is performed by exposing the sensitive material (P) to the original in which the continuous tone image is covered with the mask (M-1).

Abstract: The present invention relates to an image forming method and apparatus in which a photographic material is subjected to an exposure by scanning with laser beam being of blue, green and red wavelengths as an exposure means, the photographic material used in the above scanning exposure process is a silver halide photographic material comprising blue, green and red sensitive silver halide emulsion layers, the silver halide of at least one of which emulsion layers is silver chloroiodobromide whose silver bromide content is from zero to 65 mol %.

Abstract: A method of producing an electrostatic charge image comprising the sequential steps of: (1) bringing an electrode into proximity with a photoreceptor, the photoreceptor having a dielectric substrate and a photoconductive film intimately bonded to the substrate, the electrode having means to enable an electric field to be applied across the photoreceptor and being adapted to be brought into proximity with the substrate of the photoreceptor along a length of the electrode and charging the photoreceptor with an electrostatic charge of one polarity and projecting an image of a photograph on the receptor, (2) charging the photoreceptor with an electrostatic charge of opposite polarity, and (3) projecting a photographic image of the subject again on the photoreceptor whereby an electrostatic charge image is formed on the photoconductor surface. The invention also resides in apparatus to carry out the method.

Abstract: This invention relates to a composition of a water-soluble photopolymer which is synthesized from a water-soluble organic matter, which matter is a base polymer produced and refined particularly by bacterial culture biotechnically and contains at least one of polysaccharides, protein, gelatin, casein, polyvinyl pyrrolidone and polyvinyl alcohol, in particular pullulan which is a natural polysaccharide, and chemicals to add functions to aqueous solution of the base polymer, for example, water-soluble radiation sensitive chemical, crosslinking agent, catalyst, epoxy compound, and a compound possessing bleaching or fading action with respect to radiation.The water-soluble photopolymer can be developed in water, and is high in safety and small in aging, and is expected to be used as the material of single-layer resist or multi-layer resist of high resolution and high resistance, or as the material for contrast enhanced litography.

Abstract: The present invention provides a recording medium employing conductive polymers and a recording method employing the recording medium. The recording medium of the present invention is comprised of a substrate and a conductive polymer layer including a dopant therein and layered on the substrate. In addition, the recording method according to the present invention is effected on the basis of selective change in the amount of the dopant contained in the conductive polymers. The recording medium according to the present invention is utilizable ion the field of recording, memory and electronic devices, while displaying remarkably advantageous recording characteristics and environmental stability.

Abstract: In the process of making relief printing plates a liquid photopolymerizably layer having substantially identical negatives on each of its two sides and being in registration and also having a transparent substrate is exposed to an external light source so that both sides are exposed to the same image and after removal of the negatives the unexposed areas of the plate are removed.

Abstract: A silver halide photographic emulsion having a high spectral-sensitivity in a red-color wavelength range, especially within a wavelength range of from 600 nm to 690 nm, is disclosed, which contains one or more sensitizing dyes represented by formula (I) ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 each represents an alkyl group, a substituted alkyl group, or an alkenyl group;V.sub.1, V.sub.2, V.sub.3, and V.sub.4 each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an acyl group, an acyloxy group, an alkoxycarbonyl group, a carboxyl group, an alkoxysulfonyl group, a cyano group, or a trifluoromethyl group;Q represents an alkyl group or an aralkyl group;X.sup..crclbar. represents an anion; andm is 1 or 2, provided that when the dye forms an internal salt, m is 1.

Abstract: Photopolymerizable composition comprising monomer, photoinitiator and triarylmethane or xanthene dye exhibit increased photospeed with an exposure to light above 400 nm with an intensity of at least 1500 lumen/sq. meter for one hour or more, with a preferred exposure of 15,000 lumen/sq. meter for 10 seconds or longer. A photospeed layer protected from exposure to oxygen has been shown to continue to maintain increased photospeed.

Abstract: Industrial radiographic systems having low grainines and high information density may be constructed with intensifying screens sandwiching radiation sensitive elements having emulsions wherein the average size of the silver halide grains is less than 0.4 micrometers.

Abstract: A relief printing plate is made by exposing a photopolymer layer on a support sheet to image forming projected light radiation and then removing the unexposed portions of photopolymer. The image forming projected light radiation is provided by passing ultraviolet light radiation, which has been passed first to homogenizing means and then condensing means, through image bearing means out of contact with said photopolymer layer to a projection enlargement means which projects the resultant image upon the photopolymer layer at a predetermined ratio of enlargement greater than 1:1.

Abstract: A method of lithography employing an electromagnetic wave having a very short wave length such as X-ray and a resist layer sensitive to that electromagnetic wave is disclosed. The irradiation process is divided into two steps. One step is selectively irradiating the electromagnetic wave, as in the prior art, to the resist layer in a desired pattern. The other steps is non-selective irradiation over the entire area of the resist layer. The latter step may be conducted with a plurality of workpieces such as semiconductor wafers simultaneously.

Abstract: Process for forming a halftone or multicolor colloid pattern by the following steps in sequence:(1) scanningwise exposing to light a multicolor original carried, e.g., by a rotating scanner drum, to obtain separate red light, green light and blue light, out signals which are received by corresponding photon-conductors to produce corresponding separate series of electrical signals, which are, e.g.

Abstract: A holographic recording medium is treated to eliminate side lobes. The method involves exposing opposed surfaces of the medium with filtered incoherent light either before or after a holographic exposure with coherent light. The incoherent exposure produces controlled desensitization of the medium, resulting in a sensitivity profile which increases continuously to a maximum near the center of the layer. A hologram recorded in the layer has a refractive index modulation which is high in the center of the layer and which decreases toward the surfaces of the layer.

Abstract: Disclosed is a method for plate-making which comprises imagewise exposing by scanning type flash exposure a lithographic printing plate comprising a support and at least a silver halide emulsion layer containing at least 70 mol % of silver chloride and prepared with addition of a water soluble iridium compound during emulsification or physical ripening of silver halide and a water soluble gold compound at any time before coating of the emulsion and thereafter subjecting the exposed emulsion to diffusion transfer development.

Abstract: An image forming method which comprises copying an original on a photosensitive material employing a direct reversal photographic emulsion is disclosed. The method comprises conducting ordinary exposure when the original image is a positive image and conducting exposure at high illuminance when the original image is a negative image. Thereby, it is possible to obtain a direct positive image from either the original positive or original negative image. The process is greatly advantageous with respect to forming positive images since the process can be utilized to obtain positive images regardless whether the original image is positive or negative.

Abstract: Through a pattern mask, small sections of a semiconductor wafer are exposed successively to light radiated from a mercury-vapor lamp in high-level steps, during each of which the power consumption of the mercury-vapor lamp is at a high level, by continuously lighting the mercury-vapor lamp and repeatedly alternating each of the high-level steps and a low-level step during which the power consumption of the mercury-vapor lamp is at a low level. As the mercury-vapor lamp, there is used a mercury-vapor lamp in which mercury is filled in such a large amount that when lit in the low-level step, the mercury vapor pressure in its envelope is below 96% of the saturated mercury vapor pressure at that time. Use of such a mercury-vapor lamp is effective in avoiding the occurrence of incomplete lighting state when its power consumption is changed from the low-level step to the high-level step.

Abstract: Photocured layers possessing a defined controllable hardness are produced by exposing a layer of a photopolymerizable or photocrosslinkable mixture, which contains a partially crystalline polymeric binder possessing olefinic double bonds capable of undergoing polymerization, to actinic light, by a method in which the photocurable layer, prior to exposure to actinic light, is subjected to a heat treatment in which the partially crystalline parts of the polymeric binder are partially or completely fused.

Abstract: A process for producing a light-sensitive lithographic plate requiring no dampening solution comprising (1) carrying out corona discharge treatment on the surface of a silicone rubber layer of a light-sensitive lithographic plate requiring no dampening solution wherein the silicone rubber layer is the top layer, (2) spraying a solution or dispersion containing a non-volatile solid component on said silicone rubber layer, and (3) drying to provide fine projection patterns on said silicone rubber layer.

Abstract: A method for exposing a layer of photoresist on a sheet includes positioning the sheet in a vacuum printing frame comprising a glass plate carrying an opaque master pattern of metal or metal oxide. With the pattern opposite the coating, the frame is evacuated and the layer is exposed. The pattern has a substantially-uniform thickness in the range of about 0.5.+-.0.2 micrometer. To reduce the times for evacuating and devacuating the frame, the pattern side of the glass plate carries an array of light-transparent islands up to about 3.0-micrometer thick. An overcoating of wax on the islands is a further aid.

Abstract: In a method of forming very minute real window patterns to a negative photoresist film that are required in the manufacture of highly packed semiconductor devices, false unexposed patterns are formed in the proximity of the minute real unexposed patterns. The false patterns have a width that, upon a single exposure of the negative photoresist film to ultraviolet light or other energy beam, the photoresist film portion immediately below the false patterns are unexposed but a photoresist portion under the unexposed portion is exposed to light by reason of light diffraction or light circling around under the false pattern. As a result, the false patterns in the photoresist film substantially disappear after development of the photoresist. The partially removed false patterns serve to negate swelling of the photoresist at the time of development and prevent obliteration of the real window patterns or formation of burr-like parts where the real window patterns are to be formed.

Abstract: A presensitized plate adapted for use in lithography comprising a support member with a metal surface, e.g. aluminum metal, and overlying layer containing a diazo compound. In accordance with this invention, the relative exposure sensitivity of the diazo compound is improved by pretreatment to accelerate its reactivity in the presence of actinic light. One method of pretreatment involves preheating the diazo compound to a temperature above about 35.degree. C. up to about 120.degree. C. The improved lithographic plate and the process of preparing plate are claimed.

Abstract: By exposing a photopolymer layer to radiation under the surface of a liquid medium such as water that does not affect the photopolymer solubility characteristic, disproportionately faster exposure time with lower energy cost and heat dissipation giving longer life to equipment and phototools and reducing production costs. The water additionally synergetically reacts as a coolant dissipating heat and as a release agent permitting photo bearing images to be in direct contact with the photopolymer while being radiated without accumulation of unwanted photopolymer to scratch the image or decrease its resolution.

Abstract: Disclosed is an ablative infrared sensitive optical recording composition containing as a component thereof a dispersion of a resinous binder and an absorbing infrared sensitive tertiary butyl substituted vanadyl phthalocyanine obtained by the vapor treatment of a non-infrared sensitive tertiary butyl substituted vanadyl phthalocyanine of the following formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are tertiary butyl groups, or hydrogen, and M is vanadium oxide, subject to the provision that the average number of tertiary butyl groups present is from about 1 to 2.5, and at least one of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is tertiary butyl.

Abstract: An element for optically recording digitally encoded information which comprises a support carrying an array of discrete regular geometric spaced depressions in a surface, each of said depressions carrying material capable of a transformation in response to a level of radiation adapted to effect said transformation, wherein said transformation is optically detectable.