US3680954A - Electrography - Google Patents

Electrography Download PDF

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US3680954A
US3680954A US492988A US3680954DA US3680954A US 3680954 A US3680954 A US 3680954A US 492988 A US492988 A US 492988A US 3680954D A US3680954D A US 3680954DA US 3680954 A US3680954 A US 3680954A
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grid
image
ions
photoconductive
backing member
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US492988A
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Lee Fitzpatrick Frank
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Eastman Kodak Co
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Eastman Kodak Co
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/05—Apparatus for electrographic processes using a charge pattern for imagewise charging, e.g. photoconductive control screen, optically activated charging means
    • G03G15/051—Apparatus for electrographic processes using a charge pattern for imagewise charging, e.g. photoconductive control screen, optically activated charging means by modulating an ion flow through a photoconductive screen onto which a charge image has been formed
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20

Definitions

  • the electrophotographic process employing the reusable drum has the following disadvantages which are overcome by the present invention.
  • the machine is very expensive for the low-volume user; it does not do a good job of copying photographs and large solid areas; the machine is relatively complex and requires more than the usual amount of maintenance; it uses a selenium coated drum which is expensive and fragile and which must be replaced periodically (normally, after about every 40,000 to 50,000 copies); the process requires a developed-image transfer step; and it has a relatively low sensitometric speed.
  • the electrophotographic process which employs a single-use, photoconductor-coated, copy paper has the following disadvantages which are overcome by the present invention.
  • duplicating systems either require large, expensive machines and long makeready times or have the problems of poor quality, limited numbers of copies, and of being messy.
  • this embodiment incorporates the above discussed advantages of both the document copying and the duplicating embodiments of the invention.
  • the subject embodiment can be used to make either a single copy or a very large number of copies from a single exposure.
  • a unique electrographic recording system which comprises directing a fiow of ions toward a record medium and imagewise modulating the flow of ions to produce an image on said record medium.
  • the imagewise modulation is accomplished by interposing a grid or an array of grids in the flow of 10118.
  • the grid is a photoconductive grid.
  • the color recording embodiment uses the same photoconductive grid but employs color separation filters in the exposing step and differently colored developers in the developing step from the document copying embodiment.
  • the duplicating embodiment employs a grid similar in appearance to the photoconductive grid but different in construction in that it employs an imagewise distributed coating of insulating material on a conductive grid.
  • One character printing embodiment employs conductive grids formed in the shape of the characters to be printed.
  • the multiple copying of documents embodiment employs both photoconductive grids and insulator coated grids.
  • a record medium which has an insulating surface coating on a relatively conducting support layer.
  • the flow of ions, as imagewise modulated by the grid or grid array, produces an electrostatic charge image on the insulating surface, which charge image can be xerographically developed to produce a visible image.
  • the imagewise modulation of the flow of ions is accomplished by means of a photoconductive grid comprising a biased or grounded electrically conductive core or grid which is, in the preferred embodiments, covered with a layer of photoconductive insulating material.
  • This photoconductive grid is positioned directly in the ion flow and preferably just above the record medium.
  • the photoconductive grid is imagewise exposed to produce a conductivity image in the photoconductive material, while the flow of ions is being directed through the grid and toward the record medium and, hence, can be designated as an image grid means.
  • the terms electrically energize and imagewise energize are intended to encompass, for the purpose of this specification and claims, the biased or grounded, electrically conductive areas of the grid. In the areas of the grid which are insulating or non-energized (where the grid is not exposed) the flow of ions will first produce a small surface potential (from a few to a few hundred volts) on the grid surface and will then pass through the grid to charge the underlying insulating surface of the record medium.
  • One of the most startling efiects noted with this invention is in connection with the exceptional sensitivity of the process.
  • the maximum operating gain of the system is unity.
  • the operating gain of the system is defined as the number of stored charges removed by one absorbed photon.
  • the present system which is electrodynamic, operating gains greater than unity can be achieved.
  • This process has exhibited speeds of up to 300 times the speed of present electrophotographic systems.
  • An additionally startling effect in this connection is that of an increase in effective speed with increased resolution, i.e., a ZOO-line per inch photoconductive grid gives many times the speed of a l00-line per inch grid.
  • a 300-line per inch grid gives speeds over times faster than previous electrophotographic systems and previously considered unavailable. This simultaneous increase of speed and resolution is opposite to the relationship found in other systems, for example, in photography.
  • photoconductors both N and P types having various levels of sensitivity and dark current
  • Useful photoconductors are, among others, cadmium sulfide, selenium, selenium and tellurium mixtures, zinc oxide, arsenic trisulfide, cadmium telluride, cadmium selenide, germanium (PN or NP) and organic photoconductors such as triphenylamine in an insulating organic resin vehicle (such as that sold under the trademark Vitel PE-lOl) sensitized with 2,4-bis-(4- ethoxyphenyl)-6-(4-n-amyloxy-styryl) pyrylium fiuoroborate.
  • the effective sensitivity of a given photoconductor within the system.
  • electrical bias can be used to employ photoconductors that do not exhibit low resistance upon exposure; increasing the corona current changes the time constant depending on the geometry of the source and the nature of the photoconductor; and increased exposure tends to decrease time constants.
  • other materials which exhibit a change in conductivity upon activation can be used in the present invention in place of a photoconductor.
  • Such other materials include photoinsulators, i.e., materials which are normally conductive but which become insulating upon exposure to light, and heatsensitive materials which exhibit a change in conductivity when heated.
  • the image grid means can be considered as being coated with a radiation responsive insulating material.
  • a layer of photoconductive insulating material may be formed on the grid, for example, by evaporation techniques or by spray coating. It is necessary, however, to spray or evaporate from a widely diverse number of angles with respect to the grid so that all of the surface of the grid will be completely covered with a uniform layer of photoconductor, including the inside walls of the holes in the grid.
  • Woven mesh is hardly suitable for this process, if coated by evaporation, particularly in the finer weaves, because of the difficulty of completely covering the wire surface in the region where the wires cross each other.
  • Spray coating can be used to totally coat woven mesh for this process, provided the coating has reasonable leveling or wetting action on the mesh.
  • a wide choice is also available in connection with the electrically conductive grid which forms the core of the photoconductive grid and to which the photoconductive material is applied.
  • the choice as to the shape, size, material and method of manufacture is large. It has been found that an etched or electroforrned mesh is superior in mechanical properties for one-to-one document copying; window screening works well for moderate size posters and is stronger and less expensive; and hardware cloth can be used for very large prints. Neither the toner nor any part of the document copying apparatus ever needs to come into contact with the grid; the grid is thus indefinitely reusable. It is also relatively simple to construct and relatively inexpensive. An extremely wide choice of record mediais available, including ordinary paper at low humidities.
  • the record medium can be, for example, a single layer of insulating material, a sheet of paper or other support having a thin insulating coating, a sheet of thermal-deformable plastic or an ion-sensitive silver halide emulsion layer, but is preferably an insulating surface with a relatively large capacitance per unit area.
  • the record medium after formation of the electrostatic image thereon, can be xerographically developed, for example, by any of the well-known methods and the developed image can be fixed thereon to form the final copy, or the toner can be transferred to a final copy sheet and fixed thereto, in which case the record medium can be cleaned and reused.
  • the record medium can conveniently be in the shape of a rotatable drum; in connection with this embodiment it should be noted that the drum does not have an expensive, fragile, photosensitive coating but rather a simple, rugged, inexpensive, electrically insulating coating.
  • the preferred embodiments of the invention utilize a record medium having an insulating surface whereby an electrostatic image is produced thereon which can be xerographically developed, it is noted that the invention is not limited to such record media.
  • a Berchtold layer (a mosaic of conducting areas separated by insulating layers as described in US. Pat. No. 2,866,903) can be positioned behind the photoconductive grid with an insulating recording sheet positioned behind the Berchtold layer.
  • the record medium can be a conducting sheet which changes color in response to a flow of current therethrough, as is known in photoconductography.
  • the record medium is replaced with an electroluminescent panel, the electrographic system functions as a light amplifier. Since the electroluminescent panel glows where there is current, the image has a tonal scale reversed from that of the normal (i.e., a negative). When the gain is less than unity, the reversed tonal scale would be useful either in direct viewing of a photographic negative as a positive, or in converting a negative to a positive.
  • the imagewise pattern of ions coming from the grid can be used to form a record (either permanent or temporary) in various ways.
  • exposing methods including projection and contact exposing methods with either area exposure or line scanning.
  • the associated benefits of line scanning are usable, i.e. rightreading, wrong-reading and coand counter-current scanning.
  • Various scanning embodiments useful in the invention include (I) stationary corona charger, grid and lens with moving document and record medium for both coand counter-current scanning, and (2) stationary document and record medium with (a) moving corona charger, grid and lens system (b) moving corona charger with stationary grid and lens system, (c) moving corona charger and lens system with sta tionary grid, and (d) moving corona charger and grid with stationary lens system.
  • the conductivity image produced on the photoconductive grid may thus be spatial (in the case of large area exposure) or temporal (in the case of line scanning) or both in the case of small area scanning.
  • corona discharge electrodes such as needles and wires
  • any of such may be used in the present invention.
  • Certain arrangements of the document copying embodiment of the invention require the use of a photoconductive material which will remain conductive (exhibit persistence of conductivity) for a period of time after the illumination has been turned off and in the presence of a corona discharge.
  • the persistence of conductivity of a photoconductive material is often altered in the presence of a corona discharge.
  • the photoconductivity which would normally persist for many minutes is destroyed in slightly over a second in the presence of a corona discharge even at very low corona levels.
  • the photoconductivity will decay in less than 0.1 second, but under a corona will exhibit persistence of conductivity for several minutes.
  • the dyes to be used can be chosen for their color and stability. Many other advantages of this embodiment are disclosed above in the objects of the invention.
  • the duplicating embodiment employs a grid comprising a grounded or electrically biased conductive core or grid having an imagewise distribution of-insulating surface areas.
  • the insulating and conductive areas of the grid modulate the flow of ions in the same manner as described above with respect to the photoconductive grid.
  • the primary differencebetween the two embodiments is that the image is effectively permanent (permanent for the duration of the copy run) on the printing-master grid. As stated above this embodiment has many advantages over the known duplicating systems.
  • the character printing embodiment employs a grid comprising a grounded or biased conductive electrode formed in the shape of a character to be printed.
  • This grid modulates the flow of ions in somewhat the same manner as do the grids of the above embodiments.
  • the grid is energized to either attract or repel the ions in the flow of ions to produce an electrostatic charge image or shadow of the grid.
  • a stack of individual electrodes, made of thin wire in the shape of characters, or a grid comprising a plurality of individual electrode segments corresponding to parts of characters, can be moved across the record medium to reproduce a page of type.
  • the corona current is transmitted to the paper only when a character is to be printed.
  • the d.c. corona current can be turned on and off by auxiliary means, the dc.
  • Each electrode or electrode segment is connected to ground or to a bias potential through a switch.
  • the switch (or switches in the case of the grid employing electrode segments) corresponding to the character to be printed is closed and the remaining electrodes have practically no blocking effect and do not cast a shadow.
  • a complete row of grids with a full set of electrodes for each space in the line can be used to provide printing of a line as a whole.
  • the switches can be photocells to allow the switching to be done by light. In one embodiment, described below, the
  • photocells are arranged in an X-Y array.
  • the light pattern can be simultaneous, as in the case of exposure through a punched card, or sequential, as in the case of the output of a cathode ray tube.
  • the multiple copying of documents embodiment employs a photoconductive grid or grid array to produce an electrostatic charge image on an insulating grid (or on itself or another photoconductive insulating grid in the dark) and then this grid having the electrostatic charge image is used to modulate an ion flow to imagewise charge an insulating record medium. Many hundreds of copies can be produced from a single exposure.
  • This embodiment employs a different principle of operation from that of the previously described embodiments.
  • ions are not imagewise removed from the ion flow by means of conductive grid areas.
  • the ion flow is modulated by electrostatic fields.
  • the ions are prevented from flowing through the areas of the grid which have the charge image, but flow freely through the remaining areas of the grid.
  • the term ion flow or flow of ions is employed in describing the step of imagewise charging the record member.
  • the preferred source of charges is a corona discharge electrode and the preferred charges are air ions
  • electrons, other charged subatomic particles, charged particles of matter, etc. can be used as the flow of charges in the present invention which flow is directed toward the record member and imagewise modulated to produce an electrostatic charge image thereon.
  • This charge image can be made visible by any known xerographic developing methods.
  • Various types of charges can be used in the present invention and it is intended that the term flow of ions and ion flow be interpreted to include any of such charges and that it not be limited in meaning strictly to air ions.
  • the grid or conductive mesh in this invention is analogous to the grid in a vacuum tube in which relationship the term grid is generally defined as an electrode having one or more openings for the passage of ions therethrough, which electrode exercises control on the passage of ions without collecting more ions than is necessary.
  • the use of the term grid for the electrode of the invention which controls the flow of ions to the record medium is consistent with present usage of the tenn.
  • the term grid, as used in the present specification and claims is intended to encompass any and all electrode configurations which allow for the passage of ions therethrough; the term grid thus encompasses such constructions as are also known by the terms screen, mesh", perforated plate, slot" etc.
  • the resolution of theultimate image depends on the number of openings per linear inch in the grid and since this is commonly called lines per inch in halftone production, the same phrase lines per inch will be used in the present specification and claims to define the size of the grid. This term together with information about the percent of open area of the grid adequately defines the size of the grid. It is noted that the resolution of the grid system is determined by the number of holes per unit length only in the case of stationary operation without interaction between the holes. An example of this is the single grid system operated stationary, close to the record sheet. If a scanning system is used, the system in the direction of motion has a resolution equal to the reciprocal of the diameter of the holes, or slot width, if there is no interaction between the holes and the time frequency response of the system is not limiting.
  • the phrase imagewise exposing the grid means, of course, imagewise exposing the photoconductor to suitable radiation to which the photoconductor is sensitive. As used in the specification and claims, exposing includes exposing to visible light, x-rays, alpha, beta, and gamma rays, and particulate radiation.
  • any type of radiation may be employed that will render the photoconductor conductive.
  • the term insulating as used with respect to certain types of record media is intended to encompass any material which will hold an electrostatic charge image for a period of time long enough to allow for the development thereof. The period of time needed to develop an electrostatic image may be extremely short, as in the case of thermal-deformable or electro-deformable plastic sheet.
  • potentia or connected to a predetermined potentia is intended to include any potential including ground potential.
  • the imagewise modulation of the flow of ions can be either spatial or temporal or both; line scanning would be both, point scanning would be only temporal, and overall exposure would be only spatial.
  • FIG. 1 is a schematic illustration of one document copying embodiment of the present invention
  • FIGS. 2-6 are enlarged, perspective views of various photoconductive grids useful in the invention.
  • FIG. 7 is an enlarged cross-sectional view through another photoconductive grid useful in the invention.
  • FIG. 8 is a greatly enlarged cross-sectional view through a photoconductive grid and a record medium which illustrates certain principles of the invention
  • FIGS. 9A and 9B each schematically illustrate a multigrid embodiment of the invention.
  • FIG. 10 is a schematic diagram of an equivalent circuit of the circuit shown in FIG. 1;
  • FIG. 11 is a schematic diagram of an equivalent circuit of the circuit shown in FIG. 9A;
  • FIG. 12A is a schematic illustration of a two-grid system
  • F IG. 12B is a graph showing the characteristic output current of the circuit of FIG. 12A;
  • FIGS. 13-15 each schematically illustrate another multigrid embodiment of the invention.
  • FIGS. 16-20 each schematically illustrate a document copying embodiment of the invention.
  • FIG. 21 shows, greatly enlarged, an alternative exposure station for use in the embodiment of FIG. 19;
  • FIGS. 22A-22C schematically illustrate a simple reflex printing embodiment of the invention
  • FIG. 23 is a schematic diagram of a document copying apparatus according to one embodiment of the inventron.
  • FIG. 24 illustrates a lens system useful in the embodiment of FIG. 23
  • FIG. 25 is a schematic illustration of an embodiment in which the grid is controlled by a photoconductor spaced from the grid:
  • FIGS. 26-28 schematically illustrate an embodiment of the invention which employs a photoinsulating material:
  • FIG. 29 schematically illustrates an embodiment employing a layer of cellular material on top of the photo conductive grid for the production of reversals
  • FIG. 30 is a schematic illustration of a color reproduction embodiment of the invention.
  • FIG. 31 is a schematic illustration of a duplicating embodiment of the invention.
  • FIG. 32 shows a duplicating embodiment of the invention employing multiple grids.
  • FIG. 33 is a schematic illustration of a character printing embodiment of the invention.
  • FIG. 34 is a plan view showing a line of character printing grids for use in printing a line at a time
  • FIG. 35 is a schematic illustration of a grid composed of electrode segments for use in printing alphanumeric information
  • FIG. 36 is a schematic illustration of a alphanumeric character printing embodiment of the invention.
  • FIG. 37 is a schematic illustration of a modification of the character printing embodiment of FIG. 33;
  • FIG. 38A schematically illustrates certain principles of operation of the embodiment of FIG. 33 when the grid is biased to attract ions
  • FIG. 38B is a graph showing the charge density across an electrostatic image produced by the embodiment of FIG. 38A;
  • FIG. 38C is a graph showing the nature of the toner deposit on the electrostatic image of FIG. 38A;
  • FIG. 39A schematically illustrates certain principles of operation of the embodiment of FIG. 28 when the grid is biased to repel ions
  • FIG. 39B is a graph showing the charge density across an electrostatic image produced by the embodiment of FIG. 39A;
  • FIG. 39C is a graph showing the nature of the toner deposit on the electrostatic image of FIG. 39A;
  • FIGS. 40A and 40B schematically illustrate a twostep process 'using three grids to produce multiple copies from a single exposure
  • FIGS. 41A and 41B schematically illustrate a variation of the embodiment shown in FIGS. 40A and 40B employing an integral array of grids using a foraminous insulating spaces;
  • FIG. 42 schematically illustrates another integral grid construction useful in the process 'of FIGS. 41A and 41B;
  • FIGS. 43, 44, and 45 schematically illustrate more complex grid arrays containing larger numbers of grids for use in the multiple copying of documents embodiment of the invention
  • FIGS. 46A, 46B, and 46C show a preferred threestep process for making multiple copies from a single exposure
  • FIG. 47 schematically illustrates the exposure step of another grid structure useful for reflex printing is the general process of FIGS. 46A, 46B, and 46C;
  • FIG. 48 is aschematic illustration of an apparatus employing, for example, the grid of FIG. 47 for making single or multiple copies of documents by reflex exposure.
  • FIG. 1 illustrates one embodiment of the present invention.
  • a transparency 10 having an image to be reproduced, is illuminated by a light source 12.
  • the image is focused by a lens 14 onto a photoconductive grid 16.
  • the grid 16 consists of a grounded, electrically conductive electrode core or grid 18, for example of metal, completely covered with a layer 20 of photoconductive insulating material.
  • a record medium 22 Positioned immediately below the grid 16, is a record medium 22 consisting of an electrically insulating layer 24 on a support 26, such as paper. It should be noted that the insulating layer 24 is not, or at least need not be, a photoconductive insulating materiaLThe record medium 22 can therefore be quite inexpensive.
  • the support 26 is positioned in overlying contact with a grounded field electrode 28 during the step of imagewise charging the insulating layer 24.
  • a corona discharge is produced adjacent the grid 16 but on the opposite side thereof from the record medium 22.
  • the corona discharge is produced, for example, by connecting a corona discharge electrode 32 to one terminal of a voltage source 34 by means of a switch 36.
  • the other terminal of the voltage source 34 is connected to ground 38.
  • corona discharge provides a source of ions, and the electric field produced between the corona discharge electrode 32 and the field electrode 28, directs a flow of ions toward the record medium 22.
  • the photoconductive layer 20 is conducting, and the ions which come into proximity thereto are attracted to the photoconductive layer 20 and pass directly to ground.
  • the photoconductive layer 20 is insulating and the ions, after building up a small potential (from a few to a few hundred volts) on the surface of the grid, pass through the openings in the grid 16 to charge the underlying surface of the insulating layer 24.
  • FIGS. 2-6 are perspective views showing alternative grid constructions which are useful in the present invention.
  • FIG. 2 is a perspective view of the grid 16 of FIG. 1 showing the photoconductive insulating layer 20 and the core or grid 18.
  • the grid 18 may be formed by etching or electroforming.
  • FIG. 3 shows a grid 40 consisting of a photoconductive insulating layer 42 on an electrically conductive electrode grid which consists of a series of equi-spaced, parallel electrodes 44 connected to a common electrical line 43.
  • FIG. 4 shows a grid 50 formed from a perforated metal plate which fonns the electrode core or grid 52. The grid 52 is completely covered with a layer 54 of photoconductive insulating material.
  • FIG. 1 is a perspective view of the grid 16 of FIG. 1 showing the photoconductive insulating layer 20 and the core or grid 18.
  • the grid 18 may be formed by etching or electroforming.
  • FIG. 3 shows a grid 40 consisting of a photoconductive insulating layer 42 on an electrically
  • FIG. 5 shows a photoconductive insulating layer 56 on an electrically conductive electrode core or grid 57.
  • the core or grid 57 can be formed, for example, by electroforming in which a durable high quality stainless steel plate is covered with a photoresist, exposed to the desired pattern (to harden the exposed areas of the photoresist the photoresist in the background being subsequently washed away), etched to leave posts and then electroplated with, for example, nickel, copper, gold or silver. The plating is then peeled off of the steel plate resulting in an excellent electrically conductive electrode foil which forms the core or grid 57.
  • FIG. 6 illustrates a grid 60 in which an electrically conductive grid 61 is provided with a single, narrow slot or opening 62 having tapered faces 64.
  • FIGS. 2-6 show examples of the various shapes and constructions which the photoconductive grid of the present invention can take.
  • the resolution of the ultimate image depends on the number of openings or holes in the grid per linear inch, hereinafter referred to as lines per inch.
  • the openings or holes in the grids of FIGS. 2- 5 are on the order of about 50 to 500 lines per inch.
  • the process of the present invention has been found to operate very well with 150, 200 and 300 lines per inch grids.
  • FIG. 7 is an enlarged cross-sectional view through a photoconductive grid 70 which is identical to the grid 16 of FIGS. 1 and 2 except for the nature of the layer 72 of insulating material which covers the electrode core or grid 76.
  • the grids of FIGS. 1-6 are all shown as being completely covered with a photoconductive insulating material. In FIG. 7 only a part of the insulating layer 72 is photoconductive.
  • the insulating layer 72 of the grid 70 of FIG. 7 consists of a photoconductive insulating layer 74 on one half of the grid 70 and a nonphotoconductive, preferably opaque, insulating layer 78 covering the other half of the grid 70.
  • an opaque insulating coating can be coated over the photoconductor on one side of the grid.
  • the two layers 74 and 78 meet to provide the complete insulating layer 72.
  • the photoconductive insulating layer 74 faces both the corona discharge and the light source during exposure and imagewise charging; however certain embodiments of the invention, to be discussed below, employ different arrangements.
  • FIG. 8 illustrates how the flow of ions is modulated by the imagewise exposed image grid means or photoconductive grid.
  • the ions are either attracted to the gridin the exposed areas thereof (and thus removed from the flow of ions) or repelled from the grid due to the surface charge thereon in the unexposed areas (and thus pass through the openings in the grid).
  • a grid 80 (similar,
  • FIGS. 1 and 2 For example, to the grid 16 of FIGS. 1 and 2) is shown having a grounded electrode core or grid 82 completely covered with a layer 84 of photoconductive insulating material.
  • the grid 80 is imagewise exposed as indicated by the small arrows 96. Ions, illustrated by the long, open arrows 86, are directed from a corona discharge (not shown) to the field electrode 88 positioned behind the insulating record sheet 90, and through the grid 80.
  • the ions In striking the photoconductive layer 84 in the unexposed areas 92 thereof, the ions produce a small surface charge thereon.
  • the conducting areas 93 of the photoconductive layer 84 have a trapping action extending a certain distancefrom the photoconductive layer 84.
  • the distance at which the trapping action is effective extends to and beyond the middle of the openings or holes between the individual elements or wires of the grid 80 and thus any ions 86 directed toward such areas of the grid 80 are essentially completely trapped; that is, the ions are drawn over to the photoconductive layer 84 and pass to ground so that no ions pass through the exposed areas of the grid 80 to charge the insulating record sheet 90.
  • leakage pass-through of ions
  • This trapping action is substantially the same whether the insulating layer surrounding the electrode grid 82 is allphotoconductive or partly photoconductive and partly nonphotoconductive as shown in FIG. 7.
  • the degree of trapping depends not only on the amount of exposure and the degree of photoconductivity of the photoconductor, but also on the potential of the electrode grid 82 relative to that of the field electrode 88.
  • the electrode grid 82 has a potential somewhere between that of the corona source and that of the field electrode 88, the trapping action in the illuminated areas is somewhat reduced. If the grid 82 has a potential opposite in sign to that of the corona electrode the trapping action in the illuminated areas is somewhat increased thus tending to clean-up the background and effectively increase sensitivity. It should be noted that it is the complete coating of all the conductive surface of the grid within the picture area that allows the use of the preferred potential opposite in sign to that of the corona electrode. Even microscopic holes or cracks in the coating of photoconductor on the grid will make the system wholly inoperative with the preferred bias.
  • the developing station is preferably remote from the charging station, developer powder or toner never needs to touch the photoconductive grid; the photoconductive grid can be reused indefinitely.
  • FIG. 9A illustrates an embodiment of the invention which employs a control grid means which can take the fonn of an additional electrode grid between a photoconductive grid 102, which can be, for example, any of those shown in FIGS. 27, and an insulating record sheet 104 carried on a field electrode 106.
  • the conductive grid 100 forms an electrostatic shield and does not absorb a majority of the ion flow. By this means the voltage across the photoconductive grid 102 can be decoupled from the voltage across the record sheet 104.
  • FIG. 10 which is an approximate equivalent circuit of the system shown in FIG. 1.
  • a current source supplies current to a current divider circuit consisting of two branches. One branch represents the photoconductive grid 16 of FIG.
  • FIG. 10 1 and is shown in FIG. 10 by a capacitor 112 in parallel with a variable resistor 116 (representing photoconductance).
  • the other branch represents the air resistance between the grid 16 and the record medium 22 of FIG. 1 and is shown in FIG. 10 by a resistor 118 in series with a capacitor 114 (the series capacitance of the paper). Since no current flows from the grid 16 to the record medium 22, or vice versa, when the current source (corona) is shut off, a diode is included in each branch.
  • the transient behavior of this circuit can be analyzed in detail. However, the most significant characteristics involve the terminal voltages on the capacitors.
  • variable resistor 116 When the system is at equilibrium, there is no current flowing through the capacitor 114, so that it is charged to the potential across the photoconductor, represented by variable resistor 116. All the current is flowing through the photoconductor 20 so the final potential across it and the record medium 22 is equal to the current through it times the photoconductor resistance. The record medium 22 potential is then limited in the simple grid system of FIG. 1 to the current times the change in photoconductor resistance. It should be noted that this equivalent circuit implies that the potential deposited on the record medium is limited to the maximum potential that the photoconductor can stand. This establishes a minimum thickness and resistivity in the dark of a given photoconductor in order to provide a developable image for any given development process. It should be noted that at maximum deposited charge on the record medium the total flow of current is through the photoconductor while it has the maximum potential across it, resulting in maximum power dissipation in the photoconductor.
  • FIG. 11 shows a current source 120 (the corona source of FIG. 9A) which supplies current to two branches of a circuit.
  • One branch represents the photoconductive grid 102 of FIG. 9A and is shown by a resistor 126 in parallel with a capacitor 122.
  • the other branch represents the air resistance between the two grids and is shown by a resistor 119. Since there is no capacitor in series with the resistor 119, at equilibrium current will flow through the resistor 119.
  • a dependent current source 121 supplies current to the paper capacitance 123.
  • the current source 121 supplies 'a current equal to or slightly less than that which flows through the electrical resistance of the air.
  • the photoconductive grid 102 delivers its output into the additional grid 100, which grid 100 appears to the grid 102 to be a grounded metal plate, though it is not actually grounded.
  • the major part of the current which is delivered to the grid 100 is transmitted through it to the record sheet 104 provided there is a potential of about 300 volts or more (for convenient dimensions) between the record sheet 104 and the additional grid 100 to accelerate the flow of ions. Since the flow of ions is independent of voltages above about 300 volts (for convenient dimensions) it-is possible to put a large potential between the additional grid 100 and the record sheet 104.
  • This potential decreases the transit time of the ions between the additional grid 100 and the record sheet 104 to the point where diffusion of the image due to kinetic motion is negligible.
  • the main source of diffusion is between the photoconductive grid 102 and the additional grid 100. However, this is between two permanent parts of the apparatus which are stationary relative to each other and the amount of diffusion can be minimized by proper manufacture. Since the transit time is inversely proportioned to the potential, the record sheet 104 can be positioned more distant from the grid 100 by just increasing the potential. In embodiments which do not employ the additional grid 100, ions diffuse at angles of about 45 so that the record sheet 104 should be in virtual contact with the photoconductive grid 102.
  • FIGS. 12A and 12B give an idea of the limits of the applicability of the incremental circuit model of the double grid.
  • a metal grid system was set up as shown schematically in FIG. 12A.
  • the current to a metal receiving sheet 132 was measured as a function of the voltages on the two metal grids 130 and 131.
  • the delivered current depends only on the intergrid voltage V,, and can vary between 0 and about 4 microamps for the system shown.
  • the charging of the paper is dependent on the charging time and the intergrid surface voltage V, only, making it possible to charge the paper to hundreds of volts (limited only by breakdown or discharge through the insulator coating on the paper) with an intergrid potential of a few volts.
  • FIG. 128 shows the characteristic output current of the circuit shown in FIG. 9A as a function of the additional grid 100 to record sheet 104 voltage.
  • the parameter of variation is the potential across the photoconductive grid 102.
  • the photoconductive grid has to stand off or hold without-discharging a surface potential of about 300 volts.
  • FIG. 9A having a second, all-metal grid 100, only a tenth of the voltage is needed at about the same current as before.
  • One-tenth as thick a layer of photoconductor can be used on the photoconductive grid 102.
  • the thickness of the photoconductor layer on the photoconductive grid 102 is the primary limiting factor of the device; therefore, the resolution can be theoretically increased by about a factor of 10.
  • a thinner layer of photoconductive material on the photoconductive grid 102 is not desired, it is also possible to use, instead, a photoconductor with a higher dark current than was previously possible. This is particularly useful in extending the response of the system into the infrared, where most of the photoconductors are characterized by high dark currents.
  • the grid 100 is preferably metallic and will wear well even if it touches the dielectric surface of the record sheet 104. However, at these points, some contact-charged spots will occur in the image and some contour to the surface of the dielectric layer may be needed to minimize the areas of these spots.
  • the divorcing of the charging rate from the potential on the record sheet 104 causes an increase in the average charging rate, i.e., the charging proceeds at a uniform relatively high rate instead of tapering off.
  • the additional grid 100 effectively increases the current gain of the system. Any difficulty in employing papers and developers that would work well at low potentials can be eliminated by using the embodiment shown in FIG. 9A. It is possible to develop an insulating record sheet on a temporary conducting backing, such as an insulating paper on a metal sheet, and then remove the record sheet from the backing when the image is developed and fixed.
  • FIG. 9A When using the embodiment of FIG. 9A with a scanning exposure step, a certain amount of difficulty is encountered. Normally, the system appears in either the one or the two grid versions (FIG. 1 and FIG. 9A, respectively), to have a rapid decrease in response between 10 and 100 cycles/second when the current is delivered to a metal plate. In the one grid system (FIG. 1 the interaction between the charge on the record sheet and the rate of current delivery acts like a negative feedback loop and extends the frequency response at the expense of gain, producing acceptable scanned images. There is no evidence of such an occurrence in the two-grid system (FIG. 9A). The primary use of the embodiment shown in FIG. 9A is for relatively high resolution and high sensitivity stationary exposure of images.
  • the two-grid system of FIG. 9A can use any photoconductor that the single grid system of FIG. 1 can use. It is also possible to accomplish some compensation for the electrical properties of some photoconductors that is impossible to do in the single-grid system of FIG. 1, specifically, there are some photoconductors that have sufficient resistance even when well-exposed to develop a sufficient surface charge to allow some current to reach the paper, but when given an attractive bias, will attract the current and produce a clean image. Additional bias can compensate for resistance in the exposed areas of the photoconductors, rendering a usable image when at lower light levels, thus increasing the effective sensitivity of the system. Alternatively, photoconductors with very high impedance can be used if sufficient bias is used.
  • FIG. 9B shows an alternative arrangement of a twogrid system having the same electrical characteristics as the arrangement shown in FIG. 9A, but with improved image resolution.
  • a foraminous insulating spacer 107 is coated on its two surfaces with metal electrodes 101 and 103, which thus form metal grids corresponding to grid 100 and the metal core of photoconductor coated grid 102 of FIG. 9A. It is necessary in applying metal electrodes 101 and 103 to ensure that the metal does not coat the inner walls of the foraminous insulating spacer 107.
  • the spacer 107 may be made by drilling a regular array of small holes, typically 0.003 inches in diameter, on 0.005 inch centers, in a sheet of insulating plastic 0.006 inches thick.
  • the thickness of the spacer should optimally be about twice the diameter of the holes.
  • the number of holes per linear inch determines the resolution of the finished print, and the individual holes should have a diameter as large as is mechanically consistent with the center-to-center hole spacing.
  • Metal electrode 103 is then coated completely with photoconductor 105, either by evaporation or spraying, taking care that the holes are not filled, but that the edges of electrode 103 are thoroughly covered.
  • the use of the spacer 107 prevents any migration of charge from one hole to another in the low field region between electrodes 101 and 103 and thus improves the resolution of the finished print. There is no significant sideways migration of charge in the space between electrode 101 and receiving sheet 104 because of the high field in this region.
  • FIG. 13 shows a 3-grid system which provides a means for correcting frequency response at the expense of current gain and resolution.
  • FIG. 13 shows a corona discharge electrode 140, an image grid means or a photoconductive grid 142, an insulating record sheet 144 on a grounded, conductive field electrode 146 and a metal grid 148 analogous to the metal grid in FIG. 9A.
  • the difference between the embodiment of FIG. 13 and that shown in FIG. 9A is the use of another metal grid 150, placed in front of the 2-grid system of FIG. 9A, the photoconductive grid 142 being closer to the rear grid 148 then to the front grid 150 and the grids l48and 150 comprising the control grid means.
  • the front grid 150 is provided with a slight repelling bias and acts to limit the current through the system.
  • the bias on grid 150 is set at such a value that at an input frequency of I00 cps a small change in bias in one direction will not affect the current while a small change in the other direction will affect the current. At lower frequencies this is also the maximum current that can flow, while at higher frequencies a smaller current will flow for the same input amplitude.
  • this arrangement also has the advantage of limiting the excessive buildup of charge on the photoconductive grid 142.
  • the grid 150 can be referred to as a limiter grid.
  • the limiter grid For its use as a limiter grid it can be much coarser (be of larger mesh) and have a spacing from the photoconductive grid 142 which is large compared with the spacing of the latter from the record sheet 144 or from the screen grid" when the limiter grid is used in conjunction with a double-grid system.
  • the limiter grid therefore does not interfere appreciably with the optical image falling on the photoconductive grid 142, and does not require a high degree of mechanical precision in its construction.
  • limiter grid (l) to limit the potential on the surface of the unilluminated photoconductive grid 142 and to therefore to prevent damage to the photoconductor which might result from exceeding the voltage tolerance of the photoconductor, and (2) to prevent bulging or arching of the center of the photoconductive grid by shielding it from the strong electrostatic field which is generated by the high-voltage corona wire.
  • the limiter grid is held at a potential, relative to the conductive core of the photoconductive grid 142, which is of the same polarity as the potential on the corona wire and which is of a magnitude roughly equal to the voltage which the photoconductor can withstand.
  • the electrostatic field between the photoconductor surface and the limiter grid is such as to prevent further charging of the photoconductor.
  • the potential across the photoconductor is therefore held to a safe value.
  • the limiter grid can be used whether the photoconductive grid is followed directly by the record sheet or by other gn'ds.
  • the high voltage impressed between the photoconductive grid and the corona wire produces a strong electrostatic attraction which tends to bulge or arch the center of the photoconductive gn'd relative to its supports. This changes the spacing between the photoconductive grid and the record sheet or the fol-

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
  • Electrophotography Using Other Than Carlson'S Method (AREA)
  • Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Control Or Security For Electrophotography (AREA)
US492988A 1965-04-30 1965-09-27 Electrography Expired - Lifetime US3680954A (en)

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US3796490A (en) * 1970-10-29 1974-03-12 Electroprint Inc Electrostatic modulator for controlling flow of charged particles
US3824010A (en) * 1970-10-29 1974-07-16 Electroprint Inc Electrostatic modulator for controlling flow of charged particles
JPS4975180A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) * 1972-10-17 1974-07-19
US3850628A (en) * 1970-10-29 1974-11-26 Electroprint Inc Electrostatic modulator for controlling flow of charged particles
US3879195A (en) * 1973-01-05 1975-04-22 Horizons Inc Electrophotography with a photoconductor coated fine mesh
DE2451166A1 (de) * 1973-10-29 1975-04-30 Electroprint Inc Verfahren und vorrichtung zum elektrostatischen mehrfarbendrucken
US3898085A (en) * 1971-08-03 1975-08-05 Electroprint Inc Screen drum with screen tension adjustable axially and circumferentially
USB423883I5 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) * 1973-12-12 1976-01-27
US3936177A (en) * 1973-07-17 1976-02-03 Canon Kabushiki Kaisha Electrostatic copying machine
US3942980A (en) * 1974-07-16 1976-03-09 Addressograph-Multigraph Corporation Ion modulator device and method of using in positive and negative modes
US3945725A (en) * 1973-06-29 1976-03-23 Canon Kabushiki Kaisha Flat screen electrostatic copier
US3955128A (en) * 1974-07-31 1976-05-04 Addressograph Multigraph Corporation Charged particle optical system for curved modulators
US3976484A (en) * 1973-05-23 1976-08-24 Canon Kabushiki Kaisha Screen electrophotographic process
US3980474A (en) * 1974-10-16 1976-09-14 Addressograph Multigraph Corporation Method of ion imaging with additional control fields
US4022527A (en) * 1975-05-29 1977-05-10 Addressograph-Multigraph Corporation Ion modulator having independently controllable bias electrode
US4022528A (en) * 1975-05-29 1977-05-10 Addressograph Multigraph Corporation Ion modulator having independently controllable bias electrode
US4026700A (en) * 1975-02-24 1977-05-31 Addressograph Multigraph Corporation Charged particle modulator device and improved imaging methods for use thereof
JPS52111732A (en) * 1976-03-16 1977-09-19 Addressograph Multigraph Copy and apparatus for forming reeusable master
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US4082448A (en) * 1972-09-22 1978-04-04 Electroprint Electrostatic modulator for control of flow of charged particles
US4086088A (en) * 1976-03-25 1978-04-25 Addressograph Multigraph Corporation Imaging methods for use with charged particle modulator device
US4090876A (en) * 1976-07-19 1978-05-23 Konishiroku Photo Industry Co., Ltd. Color corrected latent electrostatic images formed using ion-beam screen, plural exposures
US4092160A (en) * 1975-03-25 1978-05-30 Addressograph-Multigraph Corp. Ion modulator having bias electrode for regulating control fields
FR2395532A1 (fr) * 1977-03-26 1979-01-19 Canon Kk Procede et appareil de formation d'images pour reprographie
US4158564A (en) * 1977-04-04 1979-06-19 Electroprint, Inc. Method and apparatus for controlling the gray scale response of a multilayer image forming screen
US4168164A (en) * 1976-07-08 1979-09-18 Konishiroku Photo Industry Co., Ltd. Screen process for forming electrostatic latent images
US4174215A (en) * 1973-05-23 1979-11-13 Canon Kabushiki Kaisha Electrophotographic screen
US4181423A (en) * 1973-10-29 1980-01-01 Electroprint, Inc. Electrostatic color printing systems and methods using modulated ion streams
US4298268A (en) * 1974-02-25 1981-11-03 Tadashi Sato Method and device for cleaning photosensitive screen in an image forming apparatus
US4332876A (en) * 1973-06-19 1982-06-01 Canon Kabushiki Kaisha Electrophotographic screen
US4593994A (en) * 1984-03-30 1986-06-10 Kabushiki Kaisha Toshiba Ion flow modulator
US4621919A (en) * 1983-07-13 1986-11-11 Canon Kabushiki Kaisha Metal drum and image holding member using the same
US5072239A (en) * 1989-12-21 1991-12-10 Texas Instruments Incorporated Spatial light modulator exposure unit and method of operation
US20020121274A1 (en) * 1995-04-05 2002-09-05 Aerogen, Inc. Laminated electroformed aperture plate
US6978941B2 (en) 2001-05-02 2005-12-27 Aerogen, Inc. Base isolated nebulizing device and methods
US7032590B2 (en) 2001-03-20 2006-04-25 Aerogen, Inc. Fluid filled ampoules and methods for their use in aerosolizers
US7040549B2 (en) 1991-04-24 2006-05-09 Aerogen, Inc. Systems and methods for controlling fluid feed to an aerosol generator
US7066398B2 (en) 1999-09-09 2006-06-27 Aerogen, Inc. Aperture plate and methods for its construction and use
US7174888B2 (en) 1995-04-05 2007-02-13 Aerogen, Inc. Liquid dispensing apparatus and methods
US7195011B2 (en) 2001-03-20 2007-03-27 Aerogen, Inc. Convertible fluid feed system with comformable reservoir and methods
US7201167B2 (en) 2004-04-20 2007-04-10 Aerogen, Inc. Method and composition for the treatment of lung surfactant deficiency or dysfunction
US20070188185A1 (en) * 2004-07-15 2007-08-16 Samsung Electronics Co., Ltd Method of inspecgin a leakage current characteristic of a dielectric layer
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US7322349B2 (en) 2000-05-05 2008-01-29 Aerogen, Inc. Apparatus and methods for the delivery of medicaments to the respiratory system
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US7771642B2 (en) 2002-05-20 2010-08-10 Novartis Ag Methods of making an apparatus for providing aerosol for medical treatment
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CA1171130A (en) * 1981-02-18 1984-07-17 Shigemichi Honda Electrostatic printing apparatus
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US3796490A (en) * 1970-10-29 1974-03-12 Electroprint Inc Electrostatic modulator for controlling flow of charged particles
US3824010A (en) * 1970-10-29 1974-07-16 Electroprint Inc Electrostatic modulator for controlling flow of charged particles
US3850628A (en) * 1970-10-29 1974-11-26 Electroprint Inc Electrostatic modulator for controlling flow of charged particles
US3898085A (en) * 1971-08-03 1975-08-05 Electroprint Inc Screen drum with screen tension adjustable axially and circumferentially
US3761173A (en) * 1971-08-27 1973-09-25 Horizons Research Inc Imaging system employing ions
JPS4859840A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) * 1971-11-11 1973-08-22 Electroprint Inc
US4082448A (en) * 1972-09-22 1978-04-04 Electroprint Electrostatic modulator for control of flow of charged particles
JPS4975180A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) * 1972-10-17 1974-07-19
US3879195A (en) * 1973-01-05 1975-04-22 Horizons Inc Electrophotography with a photoconductor coated fine mesh
US4068585A (en) * 1973-05-11 1978-01-17 Electroprint, Inc. Electrostatic printer support with controlled electrostatic surface voltage
US3976484A (en) * 1973-05-23 1976-08-24 Canon Kabushiki Kaisha Screen electrophotographic process
US4174215A (en) * 1973-05-23 1979-11-13 Canon Kabushiki Kaisha Electrophotographic screen
US4675261A (en) * 1973-06-19 1987-06-23 Canon Kabushiki Kaisha Electrophotographic process with a photoconductive screen
US4340296A (en) * 1973-06-19 1982-07-20 Canon Kabushiki Kaisha Electrophotographic apparatus
US4332876A (en) * 1973-06-19 1982-06-01 Canon Kabushiki Kaisha Electrophotographic screen
US3945725A (en) * 1973-06-29 1976-03-23 Canon Kabushiki Kaisha Flat screen electrostatic copier
US3936177A (en) * 1973-07-17 1976-02-03 Canon Kabushiki Kaisha Electrostatic copying machine
US4006983A (en) * 1973-10-29 1977-02-08 Electroprint, Inc. Electrostatic color printing systems using modulated ion streams
US4181423A (en) * 1973-10-29 1980-01-01 Electroprint, Inc. Electrostatic color printing systems and methods using modulated ion streams
DE2451166A1 (de) * 1973-10-29 1975-04-30 Electroprint Inc Verfahren und vorrichtung zum elektrostatischen mehrfarbendrucken
US3986871A (en) * 1973-12-12 1976-10-19 Addressograph-Multigraph Corporation Charged particle modulator device and improved imaging methods for use thereof
USB423883I5 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) * 1973-12-12 1976-01-27
US4298268A (en) * 1974-02-25 1981-11-03 Tadashi Sato Method and device for cleaning photosensitive screen in an image forming apparatus
US3942980A (en) * 1974-07-16 1976-03-09 Addressograph-Multigraph Corporation Ion modulator device and method of using in positive and negative modes
US3955128A (en) * 1974-07-31 1976-05-04 Addressograph Multigraph Corporation Charged particle optical system for curved modulators
US3980474A (en) * 1974-10-16 1976-09-14 Addressograph Multigraph Corporation Method of ion imaging with additional control fields
US4026700A (en) * 1975-02-24 1977-05-31 Addressograph Multigraph Corporation Charged particle modulator device and improved imaging methods for use thereof
US4092160A (en) * 1975-03-25 1978-05-30 Addressograph-Multigraph Corp. Ion modulator having bias electrode for regulating control fields
US4022528A (en) * 1975-05-29 1977-05-10 Addressograph Multigraph Corporation Ion modulator having independently controllable bias electrode
US4022527A (en) * 1975-05-29 1977-05-10 Addressograph-Multigraph Corporation Ion modulator having independently controllable bias electrode
JPS52111732A (en) * 1976-03-16 1977-09-19 Addressograph Multigraph Copy and apparatus for forming reeusable master
US4086088A (en) * 1976-03-25 1978-04-25 Addressograph Multigraph Corporation Imaging methods for use with charged particle modulator device
US4168164A (en) * 1976-07-08 1979-09-18 Konishiroku Photo Industry Co., Ltd. Screen process for forming electrostatic latent images
US4090876A (en) * 1976-07-19 1978-05-23 Konishiroku Photo Industry Co., Ltd. Color corrected latent electrostatic images formed using ion-beam screen, plural exposures
FR2395532A1 (fr) * 1977-03-26 1979-01-19 Canon Kk Procede et appareil de formation d'images pour reprographie
US4158564A (en) * 1977-04-04 1979-06-19 Electroprint, Inc. Method and apparatus for controlling the gray scale response of a multilayer image forming screen
US4621919A (en) * 1983-07-13 1986-11-11 Canon Kabushiki Kaisha Metal drum and image holding member using the same
US4593994A (en) * 1984-03-30 1986-06-10 Kabushiki Kaisha Toshiba Ion flow modulator
US5072239A (en) * 1989-12-21 1991-12-10 Texas Instruments Incorporated Spatial light modulator exposure unit and method of operation
US7628339B2 (en) 1991-04-24 2009-12-08 Novartis Pharma Ag Systems and methods for controlling fluid feed to an aerosol generator
US7040549B2 (en) 1991-04-24 2006-05-09 Aerogen, Inc. Systems and methods for controlling fluid feed to an aerosol generator
US7174888B2 (en) 1995-04-05 2007-02-13 Aerogen, Inc. Liquid dispensing apparatus and methods
US8561604B2 (en) 1995-04-05 2013-10-22 Novartis Ag Liquid dispensing apparatus and methods
US20070209659A1 (en) * 1995-04-05 2007-09-13 Aerogen, Inc. Liquid dispensing apparatus and methods
US20020121274A1 (en) * 1995-04-05 2002-09-05 Aerogen, Inc. Laminated electroformed aperture plate
US7066398B2 (en) 1999-09-09 2006-06-27 Aerogen, Inc. Aperture plate and methods for its construction and use
US20070023547A1 (en) * 1999-09-09 2007-02-01 Aerogen, Inc. Aperture plate and methods for its construction and use
US8398001B2 (en) 1999-09-09 2013-03-19 Novartis Ag Aperture plate and methods for its construction and use
US8336545B2 (en) 2000-05-05 2012-12-25 Novartis Pharma Ag Methods and systems for operating an aerosol generator
US7971588B2 (en) 2000-05-05 2011-07-05 Novartis Ag Methods and systems for operating an aerosol generator
US7748377B2 (en) 2000-05-05 2010-07-06 Novartis Ag Methods and systems for operating an aerosol generator
US7322349B2 (en) 2000-05-05 2008-01-29 Aerogen, Inc. Apparatus and methods for the delivery of medicaments to the respiratory system
US7331339B2 (en) 2000-05-05 2008-02-19 Aerogen, Inc. Methods and systems for operating an aerosol generator
US7195011B2 (en) 2001-03-20 2007-03-27 Aerogen, Inc. Convertible fluid feed system with comformable reservoir and methods
US8196573B2 (en) 2001-03-20 2012-06-12 Novartis Ag Methods and systems for operating an aerosol generator
US7032590B2 (en) 2001-03-20 2006-04-25 Aerogen, Inc. Fluid filled ampoules and methods for their use in aerosolizers
US7104463B2 (en) 2001-05-02 2006-09-12 Aerogen, Inc. Base isolated nebulizing device and methods
US6978941B2 (en) 2001-05-02 2005-12-27 Aerogen, Inc. Base isolated nebulizing device and methods
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Also Published As

Publication number Publication date
DE1522582A1 (de) 1969-09-18
GB1152309A (en) 1969-05-14
GB1149901A (en) 1969-04-23
BE680378A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1966-10-03
GB1152308A (en) 1969-05-14
ES337430A1 (es) 1968-02-16
CH459763A (fr) 1968-07-15
ES326154A1 (es) 1968-03-16
DE1522582B2 (de) 1972-04-06
NL6605860A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1966-10-31
DE1522582C3 (de) 1979-01-11

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