EP0055984A2 - Method and apparatus of producing a relatively high charge on charge-retaining materials - Google Patents
Method and apparatus of producing a relatively high charge on charge-retaining materials Download PDFInfo
- Publication number
- EP0055984A2 EP0055984A2 EP82100013A EP82100013A EP0055984A2 EP 0055984 A2 EP0055984 A2 EP 0055984A2 EP 82100013 A EP82100013 A EP 82100013A EP 82100013 A EP82100013 A EP 82100013A EP 0055984 A2 EP0055984 A2 EP 0055984A2
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- European Patent Office
- Prior art keywords
- bristles
- charge
- corona
- conductive
- brush
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05F—STATIC ELECTRICITY; NATURALLY-OCCURRING ELECTRICITY
- H05F3/00—Carrying-off electrostatic charges
- H05F3/04—Carrying-off electrostatic charges by means of spark gaps or other discharge devices
Definitions
- the present invention relates to apparatus for establishing a relatively uniform charge level on charge-retaining material, in general, and to such apparatus for establishing a uniform charge level on a moving web of such material, in particular.
- electrostatic charges on charge-retaining materials causes problems in many industries.
- electrostatic charges on potential photographs or film units within a light-tight film cassette containing a plurality of film units for use in an "instant" type photographic camera such as that scld by Polaroid Corporation, Cambridge, Massachusetts, under its registered trademark SX-70, will often cling to one another with such intensity as a result of the force of attraction developed by such electrostatic charges, that proper ejection of an exposed film unit from said film cassette can be prevented if the effects of such charges are not controlled.
- electrostatic charges are controlled by controlling the charge levels on components of said film prior to final film unit assembly.
- a limitation of electrostatic charge-controlling conductive bristle brush apparatus presently employed to establish an electrostatic charge on charge-retaining material is the inability to place an electrical potential on such a brush that is much in excess of 4.5KV without generating a corona on said conductive bristle brush. While corona might be acceptable in many charge-retaining material, charge-controlling applications, it is generally unsuitable for use with materials that are sensitive to light such as materials incorporated in many photographic products. In addition, corona produces ozone, and ozone has an odor that may be offensive to personnel in the vicinity of the corona source.
- improved conductive bristle brush electrostatic charge-controlling apparatus is provided that is capable of producing a relatively uniform charge level on charge-retaining materials at potential levels greater than a potential level where corona would normally occur.
- the apparatus includes an electrically conductive reference member, a brush having conductive bristles or filaments spaced from said reference member with one end of each of said bristles being connected to a common electrical conductor, a relatively low potential DC source connected between said common electrical conductor and said reference member, and means for limiting the current available to said conductive bristle brush from said potential source in order to prevent the generation of corona.
- the current limiting means may take the form of such things as a current limiting resistor or the addition of more conductive bristles in parallel with existing conductive bristles that limit and absorb, respectively, current necessary for the generation of corona, thereby preventing corona generation at said current limited conductive bristle brush.
- FIGs. 1 and 2 a perspective view of prior art charge-controlling apparatus controlling the electrostatic charge on a moving web of charge-retaining material 10 and an equivalent electrical schematic of said apparatus are respectively depicted.
- a roll of charge-retaining material 10 is moved over rotatably mounted cylindrical rollers 12, 14, 16 and 18 in direction 20 at the desired rate of web 10 movement by suitable drive means (not shown) coupled to said web 10.
- Brush 22 is mounted in a fixed position and in a spaced relation with respect to web 10 and backing roller 16.
- the construction of brush 22 will be described below in detail.
- brush 22 does include a multiplicity of conductive bristles or filaments 24 with an end of each of said filaments being electrically connected to common electrical conductor 26.
- Backing roller 16 is constructed of electrically conductive materials and said roller 16 is connected to ground potential through path 28.
- the output of power supply or DC potential source 30 is connected to common electrical conductor 26 through path 32.
- the input of power supply 30 is connected to a source of electrical energy at terminal 34 (not shown) through path 36. Power supply 30 and grounded backing roller 16 are connected to the same ground potential.
- electrostatic charges retained by said web 10 are controlled or regulated by said electrostatic field.
- the magnitude and polarity of the brush potential supplied by potential source 30 is established before web 10 is so moved, by empirically determining the electrostatic field intensity necessary for the desired degree of web 10 electrostatic charge regulation.
- brush 22 is spaced a finite distance from moving web 10.
- the magnitude of the potential applied to said brush 22 must be increased in order to obtain the same electrostatic field intensity over a similar arrangement where brush 22 was in actual contact with web 10. This is so because the brush-to-web spacing introduces an electrical impedance or resistance to the generation of an electrostatic field between these components.
- the electrostatic charge level on web 10 can be properly regulated at lower DC potential when brush 22 is in direct contact with said web 10. However, scratching of the surface of web 10 may occur and such scratching may render portions of web 10 useless for incorporation in an end product.
- Brushes employed to control the charge level on charge-retaining materials such as web 10 in Figs. 1 and 2 usually have a bristle or filament density in excess of 120,000 filaments per square inch and prferably in excess of 150,000 filaments per square inch.
- the number of square inches of brush filaments and the physical dimensions of a particular brush are determined by considering such factors as speed of web movement, the initial web charge level and the type of material of which the web is formed. If, as in the charge-controlling arrangement of Figs. 1 and 2, a web such as web 10 is moved over roller 16 at a relatively high rate of speed, it may be necessary to employ two or more commonly connected brushes and space them about the circumference of said roller 16 if a single brush is insufficient to establish the desired web charge level.
- Brush 22 in Figs. 1 and 2 includes a multiplicity of conductive bristles 24 with each of said bristles having one end connected to common electrical conductor 26, as previously noted.
- Bristles 24 of said brush 22 are circular in cross-section and are normally constructed of conductive materials such as conductive nylon or stainless steel. Practically any conductive material may be employed for use as bristle material so long as its electrical resistance is 500 megohms or less. Low resistances are not necessary because, unlike a corona-generated field, only a minute amount of current is utilized; primarily for leakage and for dipole orientation.
- FIG. 4a is an electrical schematic diagram of conductive bristle brush-type electrostatic charge-controlling apparatus that incorporates the sub-corona electrostatic charge level increasing apparatus of the present invention.
- brush 46 is mounted in a fixed position and in a spaced relation with respect to both web 48 and electrically conductive, rotatably mounted cylindrical backing roller 50.
- the construction of brush 46 is the same as that of brush 22 described above in Figs. 1 and 2.
- a brush such as brush 46 in Fig.
- 4a includes a multiplicity of conductive bristles or filaments 42 with an end of each of said filaments being electrically connected to common electrical conductor 54.
- Backing roller 50 is constructed of electrically conductive material and said roller 50 is connected to ground potential through path 56.
- the input of power supply 58 is connected to a source of electrical energy at terminal 60 (not shown) through path 62.
- Power supply 58 and grounded backing roller 50 are connected to the sanre ground potential.
- the output of power supply or DC potential source 58 is connected to current limiting means 64 through path 66 and the output of current
- limiting means 64 is connected to common electrical conductor 54 of conductive bristle brush 46 through path 68.
- the electrostatic charge level on web 48 is changed to the desired charge level by the relatively intense electrostatic field established between energized conductive bristle brush 46 and electrically conductive backing roller 50. If the electrostatic charge level sought to be established on, for example, web 48 by brush 46 is larger than a predetermined value, corona will be generated at said brush 46 when the magnitude of the electrical potential on said brush 46 supplied by power supply 58 equals or exceeds said predetermined value.
- the electrical potential on said brush 46 may be substantially increased above said predetermined electrical potential value without producing corona.
- corona Whether or not corona will be generated at, for example, brush 46 in the electrostatic charge-controlling apparatus of Fig. 4A, is primarily dependent upon the number and size of bristles 52 of brush 46 as well as the magnitude of the potential applied to said brush 46. If the number of bristles in brush 46 is large enough, the desired electrostatic charge level may be ontained before corona develops. However, if corona should develop at a brush potential level necessary to obtain the desired electrostatic charge level on a charge-retaining material, said corona can be suppressed by limiting the available current to a level that is below that necessary to generate and/or sustain said corona.
- Current limiting means 64 in Fig. 4a limits the current available to conductive bristle brush 46 from potential or power supply 58 to less than a level necessary for the generation of corona.
- Current limiting means 64 may take any number of different forms. In Fig. 4b, for example, current limiting means 64 of Fig. 4a takes the form of additional conductive bristles 72 in conductive bristle brush 74. It is useful to consider bristles 52 of conductive bristle brush 46 to be analogous to a multiplicity of resistors, of equal value, that are connected between path 66, that is connected to 6 the high voltage output terminal of power supply 58, and ground path 56 in Fig. 4a. Such an arrangement is represented by resistors 52a, 52b, 52c, etc.
- Bristles 72 of brush 74 are connected in parallel with bristles 52, which is analogous to adding resistors 72a, 72b, etc. in parallel with resistors 52a, 52b, 52c, etc. in Fig. 4c.
- bristles 72 resistors 72a, 72b, etc.
- bristles 52a, 52b, 52c, etc. current from power supply 58 in Fig. 4a that would otherwise flow through bristles 52 and generate corona is shunted through bristles 72 thereby suppressing corona generation.
- current limiting means 64 in the charge-controlling apparatus of Fig. 4a may take the form of a current-limiting resistor.
- the ohmic valve of the resistance of said resistor must also be large enough to limit current to a level below that necessary for the generation of corona in order to suppress any corona that would otherwise be produced by, for example, brush 52 in Fig. 4a.
- the degree to which current through a conductive bristle brush must be limited to preclude the generation of-corona is defined by the graph 76 of conductive bristle brush current as a function of brush-to-roller voltage depicted in Fig. 5. As shown in Fig. 5, without additional bristles or a current limiting resistor, corona would begin to develop at brush-to-roller voltage 78 as brush current changed in accordance with graph 80 in said Fig. 5.
- electrostatic field means one species of electric field.
Abstract
Description
- The present invention relates to apparatus for establishing a relatively uniform charge level on charge-retaining material, in general, and to such apparatus for establishing a uniform charge level on a moving web of such material, in particular.
- The presence of electrostatic charges on charge-retaining materials causes problems in many industries. In the photographic industry, for example, electrostatic charges on potential photographs or film units within a light-tight film cassette containing a plurality of film units for use in an "instant" type photographic camera, such as that scld by Polaroid Corporation, Cambridge, Massachusetts, under its registered trademark SX-70, will often cling to one another with such intensity as a result of the force of attraction developed by such electrostatic charges, that proper ejection of an exposed film unit from said film cassette can be prevented if the effects of such charges are not controlled. In the SX-70 photographic film units mentioned above, for example, electrostatic charges are controlled by controlling the charge levels on components of said film prior to final film unit assembly.
- In my copending U.S.'patent application, Serial No. 183,326, filed September 2, 1980, a brush-like device is employed to establish a desired electrostatic charge level on a moving web of charge-retaining material by passing said web through a relatively intense electrostatic field generated by said device when it is electrically connected to a relatively low potential DC source of suitable magnitude and polarity. A similar but more limited disclosure of said brush-like device is contained at
page 70 in the February, 1980, issue of "Research Disclosure". - A limitation of electrostatic charge-controlling conductive bristle brush apparatus presently employed to establish an electrostatic charge on charge-retaining material is the inability to place an electrical potential on such a brush that is much in excess of 4.5KV without generating a corona on said conductive bristle brush. While corona might be acceptable in many charge-retaining material, charge-controlling applications, it is generally unsuitable for use with materials that are sensitive to light such as materials incorporated in many photographic products. In addition, corona produces ozone, and ozone has an odor that may be offensive to personnel in the vicinity of the corona source.
- In accordance with the teachings of the present invention, improved conductive bristle brush electrostatic charge-controlling apparatus is provided that is capable of producing a relatively uniform charge level on charge-retaining materials at potential levels greater than a potential level where corona would normally occur. The apparatus includes an electrically conductive reference member, a brush having conductive bristles or filaments spaced from said reference member with one end of each of said bristles being connected to a common electrical conductor, a relatively low potential DC source connected between said common electrical conductor and said reference member, and means for limiting the current available to said conductive bristle brush from said potential source in order to prevent the generation of corona. The current limiting means may take the form of such things as a current limiting resistor or the addition of more conductive bristles in parallel with existing conductive bristles that limit and absorb, respectively, current necessary for the generation of corona, thereby preventing corona generation at said current limited conductive bristle brush.
-
- Fig. 1 is a perspective view of a mechanical schematic of conductive bristle brush-type charge-controlling apparatus constructed in accordance with the prior art, and a moving web of charge-retaining material having its electrostatic charge controlled by said apparatus.
- Fig. 2 is an equivalent electrical schematic of the conductive bristle brush-type electrostatic charge-controlling apparatus depicted in Fig. 1.
- Fig. 3 is a graph of conductive bristle brush current as a function of brush-to-backing roller voltage of the prior art charge-controlling apparatus of Figs. 1 and 2.
- Fig. 4a is an electrical schematic diagram of conductive bristle brush-type electrostatic charge-controlling apparatus that incorporates the inventive concept of the present invention.
- Fig. 4b is a schematic diagram of an additional conductive bristle brush connected in parallel with the conductive bristle brush schematically illustrated in Fig. 4a.
- Fig. 4c is an electrical circuit that approximates the electrical impedance between the conductive bristle brush and the backing roller in Fig. 4a when additional bristles are employed.
- Fig. 5 is a graph of conductive bristle bfush current as a function of brush-to-backing roller voltage of the charge-controlling apparatus of the present invention that is depicted in Fig. 4a.
- In order to facilitate describing the preferred embodiments of the present invention, a brief description of electrostatic charge-controlling apparatus presently available in the prior art, over which the present invention is an improvement, will be provided.
- Turning now to the drawings, in Figs. 1 and 2, a perspective view of prior art charge-controlling apparatus controlling the electrostatic charge on a moving web of charge-retaining
material 10 and an equivalent electrical schematic of said apparatus are respectively depicted. A roll of charge-retainingmaterial 10 is moved over rotatably mountedcylindrical rollers direction 20 at the desired rate ofweb 10 movement by suitable drive means (not shown) coupled to saidweb 10. -
Brush 22 is mounted in a fixed position and in a spaced relation with respect toweb 10 andbacking roller 16. The construction ofbrush 22 will be described below in detail. For the present, however, it should be noted thatbrush 22 does include a multiplicity of conductive bristles orfilaments 24 with an end of each of said filaments being electrically connected to commonelectrical conductor 26.Backing roller 16 is constructed of electrically conductive materials and saidroller 16 is connected to ground potential throughpath 28. The output of power supply or DCpotential source 30 is connected to commonelectrical conductor 26 throughpath 32. The input ofpower supply 30 is connected to a source of electrical energy at terminal 34 (not shown) throughpath 36.Power supply 30 and groundedbacking roller 16 are connected to the same ground potential. Whenpower supply 30 is energized, a relatively intense electrostatic field is established between the free ends ofbristles 24 ofbrush 22 and groundedbacking roller 16. The use of a multiplicity of conductive bristles or filaments in the form ofbrush 22 coupled to a suitable potential source results in an electrostatic field being established betweenbrush 22 androller 16 by means of an electrical potential whose magnitude is substantially less than that necessary for the generation of corona. The reason for being able to establish a relatively intense field with a relatively low voltage will be explained below in detail. - As
web 10 is moved indirection 20 overroller 16 between the free ends ofbristles 24 andgrounded roller 16, through the relatively intense electrostatic field established between said free bristle ends and saidroller 16, electrostatic charges retained by saidweb 10 are controlled or regulated by said electrostatic field. The magnitude and polarity of the brush potential supplied bypotential source 30 is established beforeweb 10 is so moved, by empirically determining the electrostatic field intensity necessary for the desired degree ofweb 10 electrostatic charge regulation. - In the apparatus of Figs. 1 and 2,
brush 22 is spaced a finite distance from movingweb 10. By so spacing saidbrush 22 from said movingweb 10, the magnitude of the potential applied to saidbrush 22 must be increased in order to obtain the same electrostatic field intensity over a similar arrangement wherebrush 22 was in actual contact withweb 10. This is so because the brush-to-web spacing introduces an electrical impedance or resistance to the generation of an electrostatic field between these components. The electrostatic charge level onweb 10 can be properly regulated at lower DC potential whenbrush 22 is in direct contact with saidweb 10. However, scratching of the surface ofweb 10 may occur and such scratching may render portions ofweb 10 useless for incorporation in an end product. - Brushes employed to control the charge level on charge-retaining materials such as
web 10 in Figs. 1 and 2 usually have a bristle or filament density in excess of 120,000 filaments per square inch and prferably in excess of 150,000 filaments per square inch. The number of square inches of brush filaments and the physical dimensions of a particular brush are determined by considering such factors as speed of web movement, the initial web charge level and the type of material of which the web is formed. If, as in the charge-controlling arrangement of Figs. 1 and 2, a web such asweb 10 is moved overroller 16 at a relatively high rate of speed, it may be necessary to employ two or more commonly connected brushes and space them about the circumference of saidroller 16 if a single brush is insufficient to establish the desired web charge level. -
Brush 22 in Figs. 1 and 2 includes a multiplicity ofconductive bristles 24 with each of said bristles having one end connected to commonelectrical conductor 26, as previously noted.Bristles 24 of saidbrush 22 are circular in cross-section and are normally constructed of conductive materials such as conductive nylon or stainless steel. Practically any conductive material may be employed for use as bristle material so long as its electrical resistance is 500 megohms or less. Low resistances are not necessary because, unlike a corona-generated field, only a minute amount of current is utilized; primarily for leakage and for dipole orientation. - It is a well-known electrical phenomenon that more intense electrostatic fields can be generated at sharp angle or small radius of curvature surfaces for the same applied potential than at smooth or large radius of curvature surfaces. The most useful conductive bristle brushes have bristle diameters of 50 microns or less. With a bristle of this size, the surface at the tip or free end of said bristle forms a surface with a radius that approaches zero. With a radius of this magnitude, a relatively intense electrostatic field can be generated at the tip of such a bristle with a potential that is well below the approximately 4.5 KV DC level where a corona would normally first appear and very often at a potential of 1.5 KV DC.
- In the operation of the prior art apparatus of Figs. 1 and 2,
web 10 is moved between the free ends ofconductive bristle brush 22 andbacking roller 16 indirection 14 by drive means (not shown) for the purpose of having its electrostatic charge level regulated by the electrostatic field established betweenbrush 22 androller 16. The intensity of this field is dependent upon the magnitude of the voltage between saidbrush 22 and saidroller 16. For every brush 22-to-roller 16 voltage level there is a corresponding brush current level. As noted above, this brush current is primarily to compensate for current leakage and for web charging. Agraph 38 of conductive bristle brush current as a function of brush 22-to-roller 16 voltage is shown in Fig. 3. As shown in Fig. 3, oncebrush 22 current increases tocurrent level 40, said brush current remains relatively constant between brush-to-roller voltages roller 16 voltage is increased beyondvoltage level 44, corona will be generated at saidbrush 22, andbrush 22 current will increase in order to sustain said corona. The presence of corona is unacceptable in many electrostatic charge-regulating applications, especially when regulating electrostatic charges on light sensitive materials. The generation of corona at a particular brush 22-to-roller 16 voltage level limits the maximum electrostatic charge level that can be established on, for example,web 10 bybrush 22 to a charge level corresponding to said particular brush 22-to-roller 16 voltage level if the presence of corona is to be avoided. The electrostatic charge regulating apparatus of the present invention substantially increases the charge level to which a charge on charge-retaining material can be regulated without generating an undesirable corona. - Turning now to the present invention and to Fig. 4a, where apparatus incorporating a preferred embodiment of said present invention is depicted. Fig. 4a is an electrical schematic diagram of conductive bristle brush-type electrostatic charge-controlling apparatus that incorporates the sub-corona electrostatic charge level increasing apparatus of the present invention. In Fig. 4a,
brush 46 is mounted in a fixed position and in a spaced relation with respect to bothweb 48 and electrically conductive, rotatably mountedcylindrical backing roller 50. The construction ofbrush 46 is the same as that ofbrush 22 described above in Figs. 1 and 2. As discussed above, a brush such asbrush 46 in Fig. 4a includes a multiplicity of conductive bristles orfilaments 42 with an end of each of said filaments being electrically connected to commonelectrical conductor 54. Backingroller 50 is constructed of electrically conductive material and saidroller 50 is connected to ground potential throughpath 56. The input ofpower supply 58 is connected to a source of electrical energy at terminal 60 (not shown) throughpath 62.Power supply 58 and grounded backingroller 50 are connected to the sanre ground potential. The output of power supply or DCpotential source 58 is connected to current limiting means 64 throughpath 66 and the output of current - limiting means 64 is connected to common
electrical conductor 54 of conductive bristlebrush 46 throughpath 68. - As web of charge-retaining
material 48 is moved indirection 70 between conductive bristlebrush 46 and grounded backingroller 50, at the desired rate ofweb 48 movement, by suitable means (not shown) coupled to saidweb 58, the electrostatic charge level onweb 48 is changed to the desired charge level by the relatively intense electrostatic field established between energized conductive bristlebrush 46 and electricallyconductive backing roller 50. If the electrostatic charge level sought to be established on, for example,web 48 bybrush 46 is larger than a predetermined value, corona will be generated at saidbrush 46 when the magnitude of the electrical potential on saidbrush 46 supplied bypower supply 58 equals or exceeds said predetermined value. By employing an embodiment of the inventive concept of the present invention, the electrical potential on saidbrush 46 may be substantially increased above said predetermined electrical potential value without producing corona. - In order to produce and/or sustain a corona, it is essential that sufficient current or ions be made available for movement between the corona-generating electrode and an electrically conductive reference member. By contrast, in the prior art sub-corona conductive bristle brush-type electrostatic charge-controlling apparatus of Figs. 1 and 2, for example, only a minimal amount of current is necessary for proper control of electrostatic charges on a charge-retaining material. Whereas current in the order of milliamps is necessary for corona, conductive bristle brush current in the neighborhood of 10 microamps is sufficient for electrostatic charge-controlling purposes.
- Whether or not corona will be generated at, for example,
brush 46 in the electrostatic charge-controlling apparatus of Fig. 4A, is primarily dependent upon the number and size ofbristles 52 ofbrush 46 as well as the magnitude of the potential applied to saidbrush 46. If the number of bristles inbrush 46 is large enough, the desired electrostatic charge level may be ontained before corona develops. However, if corona should develop at a brush potential level necessary to obtain the desired electrostatic charge level on a charge-retaining material, said corona can be suppressed by limiting the available current to a level that is below that necessary to generate and/or sustain said corona. - Current limiting means 64 in Fig. 4a limits the current available to conductive bristle
brush 46 from potential orpower supply 58 to less than a level necessary for the generation of corona. Current limitingmeans 64 may take any number of different forms. In Fig. 4b, for example, current limiting means 64 of Fig. 4a takes the form of additionalconductive bristles 72 in conductive bristlebrush 74. It is useful to considerbristles 52 of conductive bristlebrush 46 to be analogous to a multiplicity of resistors, of equal value, that are connected betweenpath 66, that is connected to 6 the high voltage output terminal ofpower supply 58, andground path 56 in Fig. 4a. Such an arrangement is represented byresistors Bristles 72 ofbrush 74 are connected in parallel withbristles 52, which is analogous to addingresistors 72a, 72b, etc. in parallel withresistors resistors 72a, 72b, etc.) in parallel with bristles 52 (resistors power supply 58 in Fig. 4a that would otherwise flow throughbristles 52 and generate corona is shunted throughbristles 72 thereby suppressing corona generation. - If the placement of additional conductive bristles in parallel with existing bristles is either inappropriate or undesirable, current limiting means 64 in the charge-controlling apparatus of Fig. 4a may take the form of a current-limiting resistor. The ohmic valve of the resistance of said resistor must also be large enough to limit current to a level below that necessary for the generation of corona in order to suppress any corona that would otherwise be produced by, for example,
brush 52 in Fig. 4a. - Whether it is the bristle increasing technique illustrated in Figs. 4b and 4c, or the current limiting resistor mentioned above, the degree to which current through a conductive bristle brush must be limited to preclude the generation of-corona is defined by the
graph 76 of conductive bristle brush current as a function of brush-to-roller voltage depicted in Fig. 5. As shown in Fig. 5, without additional bristles or a current limiting resistor, corona would begin to develop at brush-to-roller voltage 78 as brush current changed in accordance withgraph 80 in said Fig. 5. However, by adding more conductive bristles or a current limiting resistor in the manner described above, corona would not develop until increased brush-to-roller voltage level 82 was established betweenbrush 46 androller 50 as brush current changed in accordance withgraph 76 in Fig. 5. - The term "electrostatic field" employed herein means one species of electric field.
- It will be apparent to those skilled in the art from the foregoing description of my invention that various improvements and modifications can be made in it without departing from its true scope. The embodiments described herein are merely illustrative and they should not be viewed as the only embodiments that might encompass my invention.
Claims (8)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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US22233281A | 1981-01-05 | 1981-01-05 | |
US222332 | 1981-01-05 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0055984A2 true EP0055984A2 (en) | 1982-07-14 |
EP0055984A3 EP0055984A3 (en) | 1982-09-29 |
EP0055984B1 EP0055984B1 (en) | 1986-08-06 |
Family
ID=22831776
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP82100013A Expired EP0055984B1 (en) | 1981-01-05 | 1982-01-04 | Method and apparatus of producing a relatively high charge on charge-retaining materials |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0055984B1 (en) |
JP (1) | JPS57164757A (en) |
CA (1) | CA1178644A (en) |
DE (1) | DE3272402D1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0055983A2 (en) * | 1981-01-05 | 1982-07-14 | Polaroid Corporation | Electrostatically assisted coating gap |
US4761709A (en) * | 1984-10-29 | 1988-08-02 | Xerox Corporation | Contact brush charging |
EP0295431A1 (en) * | 1987-06-19 | 1988-12-21 | Till Keesmann | Device for modifying the static electric potential by corona discharge of a surface made of an insulating material of a moved element |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH08315956A (en) * | 1995-05-18 | 1996-11-29 | Kasuga Denki Kk | Corona discharge treatment method of vessel, and device therefor |
DE102008018920A1 (en) * | 2008-04-15 | 2009-10-22 | Lindauer Dornier Gmbh | Pinning electrode arrangement |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2774921A (en) * | 1953-04-23 | 1956-12-18 | Haloid Co | Apparatus for electrostatically charging insulating image surfaces for electrophotography |
GB976027A (en) * | 1962-05-17 | 1964-11-25 | Eastman Kodak Co | Method and apparatus for electrostatic charging |
US3308344A (en) * | 1965-03-04 | 1967-03-07 | Ener Jet Corp | High voltage antistatic apparatus |
DE2120397A1 (en) * | 1970-04-27 | 1971-11-18 | Progil | Removal of static charges from plastic film |
DE2301313A1 (en) * | 1972-01-14 | 1973-08-02 | Kuraray Co | DEVICE FOR REDUCING THE STATIC CHARGES ON COPY PAPER DELIVERED FROM A COPY MACHINE |
DE2237282B2 (en) * | 1971-07-30 | 1974-03-21 | Eastman Kodak Co., Rochester, N.Y. (V.St.A.) | Method for removing electrical charges from an insulating tape |
DE2363209A1 (en) * | 1973-11-30 | 1975-01-16 | Gruenenfelder Eltex Elektron | Charge carrier generator for static charge dissipation - has row of electrodes with current limited supply facing single serrated counter electrode |
US4213167A (en) * | 1978-03-31 | 1980-07-15 | Cumming James M | Planar gas and ion distribution |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5418737A (en) * | 1977-07-12 | 1979-02-13 | Sharp Corp | Electrophotographic method |
-
1982
- 1982-01-04 DE DE8282100013T patent/DE3272402D1/en not_active Expired
- 1982-01-04 EP EP82100013A patent/EP0055984B1/en not_active Expired
- 1982-01-04 CA CA000393517A patent/CA1178644A/en not_active Expired
- 1982-01-05 JP JP54882A patent/JPS57164757A/en active Pending
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2774921A (en) * | 1953-04-23 | 1956-12-18 | Haloid Co | Apparatus for electrostatically charging insulating image surfaces for electrophotography |
GB976027A (en) * | 1962-05-17 | 1964-11-25 | Eastman Kodak Co | Method and apparatus for electrostatic charging |
US3308344A (en) * | 1965-03-04 | 1967-03-07 | Ener Jet Corp | High voltage antistatic apparatus |
DE2120397A1 (en) * | 1970-04-27 | 1971-11-18 | Progil | Removal of static charges from plastic film |
DE2237282B2 (en) * | 1971-07-30 | 1974-03-21 | Eastman Kodak Co., Rochester, N.Y. (V.St.A.) | Method for removing electrical charges from an insulating tape |
DE2301313A1 (en) * | 1972-01-14 | 1973-08-02 | Kuraray Co | DEVICE FOR REDUCING THE STATIC CHARGES ON COPY PAPER DELIVERED FROM A COPY MACHINE |
DE2363209A1 (en) * | 1973-11-30 | 1975-01-16 | Gruenenfelder Eltex Elektron | Charge carrier generator for static charge dissipation - has row of electrodes with current limited supply facing single serrated counter electrode |
US4213167A (en) * | 1978-03-31 | 1980-07-15 | Cumming James M | Planar gas and ion distribution |
Non-Patent Citations (2)
Title |
---|
EP-A-82100011.4 * |
RESEARCH DISCLOSURE, No. 190, February 1980, Havant, England. P.T. Andrews et al: "Controlling Polar Charge with Low Electrical Potentials", page 70, no. 19031 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0055983A2 (en) * | 1981-01-05 | 1982-07-14 | Polaroid Corporation | Electrostatically assisted coating gap |
EP0055983B1 (en) * | 1981-01-05 | 1987-05-06 | Polaroid Corporation | Electrostatically assisted coating gap |
US4761709A (en) * | 1984-10-29 | 1988-08-02 | Xerox Corporation | Contact brush charging |
EP0295431A1 (en) * | 1987-06-19 | 1988-12-21 | Till Keesmann | Device for modifying the static electric potential by corona discharge of a surface made of an insulating material of a moved element |
Also Published As
Publication number | Publication date |
---|---|
DE3272402D1 (en) | 1986-09-11 |
CA1178644A (en) | 1984-11-27 |
JPS57164757A (en) | 1982-10-09 |
EP0055984A3 (en) | 1982-09-29 |
EP0055984B1 (en) | 1986-08-06 |
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