US3714665A

US3714665A - Electrostatic recording with improved electrostatic charge retention

Info

Publication number: US3714665A
Application number: US00006633A
Authority: US
Inventors: E Mutschler; U Klavsons
Original assignee: Xerox Corp
Current assignee: Xerox Corp
Priority date: 1970-01-28
Filing date: 1970-01-28
Publication date: 1973-01-30
Anticipated expiration: 1990-01-30

Abstract

Method and apparatus for electrostatic recording on ordinary paper. An electrostatic latent charge pattern to be developed is deposited on dry ordinary paper. A conductive member is positioned in contact with the other surface of the paper from the point of charge deposition to the development area. The electrostatic latent charge pattern is then developed in the development area.

Description

United States Paten n91 Mutschler et a1. a

[ 1 Jan. 30, 1973 1541 ELECTROSTATIC RECORDING WITH IMPROVED ELECTROSTATIC CHARGE RETENTION [75] Inventors: Edward C. Mutschler, Pittsford; Uldis Klavsons, Fair'port, both of [73] Assignee: Xerox Corporation, Rochester, NY.

[22] Filed: Jan. 28, 1970 [21] Appl. No.: 6,633

Related U.S. Application Data [63] Continuation-impart of Ser. No. 693,893, Dec. 27,

1967, abandoned.

[52] U.S. Cl. .....346/74 ES, 117/37,LE, 118/D1G. 23 [51] Int. Cl ..G0l d 15/06, B41f23/06, B411 23/20 [58] Field of Search ..346/74 ES; lOl/DIG. 13;

[56] References Cited UNITED STATES PATENTS 3,411,482 11/1968 Brodie ..346/74 ES 2,885,556 5/1959 Gundlach ..346/74 ES 2,807,703 9/1957 Roshon ..117/17.5 2,859,673 '11/1958 Hix et a1 ..346/74 ES 3,519,253 7/1970 Aser et a1. ..117/17.5 2,889,758 6/1959 Bolton ..346/74 ES 3,394,385 7/1968 Lloyd ..346/74 ES Primary Examiner-Bernard Konick Assistant ExaminerJay P. Lucas Attorney-James J. Ralabate, John E. Beck and Irving Keschner [57] ABSTRACT Method and apparatus for electrostatic recording on ordinary paper. An electrostatic latent charge pattern to be developed is deposited on dry ordinary paper. A conductive member is positioned in contact with the other surface of the paper from the point of charge deposition to the development area. The electrostatic latent charge pattern is then developed in the development area. A

13 Claims, 6 Drawing Figures PATENTED JM|30 I975 3, 7 1 4 6 65 SHEET 10F 3 INVENTORS EDWARD C. MUTSCHLER BY ULDIS KLAVSONS PATENTEDJAIM 30 ms SHEET 2 [IF 3 ELECTROSTATIC RECORDING WITH IMPROVED ELECTROSTATIC CHARGE RETENTION CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of US. application, Ser. No. 693,893, filed Dec. 27, 1967 now abandoned.

BACKGROUND OF THE INVENTION Prior art electrostatic recording systems produce a latent electrostatic image on a dielectric recording surface. In general, the electrostatic image pattern is produced by virtue of an electrical discharge from electrodes directed to an electrode located behind the dielectric recording media. A wide variety of techniques, utilizing contact styli, sheet transfer of electrostatic charge, and transfer from shaped electrodes have all been employed in this area. The electrostatic recording process consists broadly of three steps. The first step comprises establishing or printing electrically charged areas on selective portions of a recording media which are representative of information in the form of letters, lines dots, etc. The second step consists of developing these charged areas on the recording media by means of a developing powder generally referred to as toner, which makes them visible. The third step, which is optional, consists in fixing or rendering the developed areas substantially permanent.

The prior art in this area contains occasional references to the use of pre-dried paper as the recording medium. In general, the paper is pre-baked to high temperatures on the order of 300 F and then kept in an environment of relative humidity on an order of less than percent by being held in a container containing a desiccant until immediately before its use. However, any charge deposited on such pre-dried paper tends to be dispersed both laterally and through the paper resulting in a loss of charge with attendant loss of resolution and clarity of the image within a few seconds after deposition of the initial charge. A large part of this difficulty apparently arises from the fact that the charge disperses laterally even onextremely dry paper within a few seconds of its deposition. There has therefore never been a particularly practical or effective system which could employ the use of ordinary paper in its uncoated'form to receive electrostatic images.

It has thus been a major problem in the prior art that shortly after charging the charge is lost and the image effectively destroyed, in many cases long before the development could take place in the system in which it was desired to use ordinary paper.

SUMMARY OF THE INVENTION The present invention provides novel method and apparatus for developing electrostatic images. In particular, the present invention provides a technique for developing electrostatic images formed on ordinary paper, the paper being in contact with a conductive electrode from the charging station into the developing area.

It is an object of the present invention to provide novel method and apparatus for recording electrostatic images on a substrate.

It is a further object ofthe present invention to provide novel method and apparatus for recording electrostatic images on ordinary paper.

It is an object of the present invention to provide novel method and apparatus for recording electrostatic images on ordinary paper wherein an electrically conductive member is maintained in contact with said paper from the charging station into the development area.

It is still a further object of the present invention to provide novel method and apparatus for recording electrostatic images on ordinary paper wherein an electrically conductive member is maintained in contact with said paper from the charging station into the development area and wherein the paper between the charging station and the development area is enclosed by a chamber containing a desiccant.

DESCRIPTION OF THE DRAWINGS For a better understanding of the invention as well as other objects and further features thereof, reference is made to the following description which is to be read in conjunction with the accompanying drawings wherein:

FIG. 1 is a cross-sectional representation of a first embodiment of the present invention;

FIG. 2 is a perspective view of development apparatus which may be utilized in the present invention;

FIG. 3 is a cross-sectional representation of a second embodiment of the present invention;

FIG. 4 is a cross-sectional representation of a third embodiment of the present invention;

FIG. 5 is a cross-sectional representation of a fourth embodiment of the present invention; and

FIG. 6 is a cross-sectional representation of a fifth embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention illustrating the operative principles of the present invention is shown in FIG. 1. A roll of pre-dried paper 8 for deposition of electrostatic charge thereon is provided. The pre-dried paper is normally packaged in sealed packages containing a desiccant to keep the moisture content of the paper low. A paper moisture content of less than three percent is preferred. Suitable drive means (not shown) feeds the paper 10 from the paper roll 8 to a backing electrode 12 which is grounded. The paper contacts the surface of the backing electrode 12 as it move thereacross. The backing electrode 12 extends into the development apparatus 20. A charging station 16 is provided to deposit electrostatic charge on the paper in the area where paper 10 initially contacts backing electrode 12. Any suitable means of depositing electrostatic charge may be employed at charging station 16; however, a contact stylus array is preferred. Typical contact stylus arrays suitable for use in the present invention are 5 X 7 pin matrices operated at approximately 750 volts or 13 pin stylus matrices operated at approximately 600 volts. At slow speeds somewhat lower potentials may be employed. In general for typical operating speeds and pressure voltages ranging from 600 to 1000 volts may be utilized.

In the alternative, an array of ion guns may be utilized at the charging station in lieu of a contact stylus array. Any other suitable electrode arrangment as disclosed in the prior art may also be utilized at charging station 16.

For slow operating speeds (paper flow rate of approximately 0.1 to approximately l inches per second) a blower 18 may be provided between the charging station 16 and the development apparatus 20 to direct a desiccant, such as dry air or gas, across the surface of the paper after it has been charged at charging station 16. The total distance between the charging station and the end of the developer station may be as little as 10 inches in a typical arrangment so that utilizing a paper flow rate of 60 inches per second in the fast speed mode, less than one sixth of a second is involved in moving the paper from the charging station to the developer. For slow operating speeds, the paper may move at rates to that as much as a minute may pass prior to development. The development apparatus comprises a dispenser 22 for dispensing developer particles 24, such as toner, into the area between a pair of biased

conductive electrodes

26 and 28 which are separated by insulative material. Conductive electrode 28, as shown in FIG. 1, is in electrical contact with backing electrode 12. It should be noted that backing electrode 12 may extend into the development apparatus 20 and function as a biased conductive electrode, eliminating the necessity of a separate electrode 28. The essential requirement of the present invention is that a conductive backing be maintained in contact with the paper web from the point at which it is charged into the development area. The backing electrode 12 may be grounded, as shown in FIG. 1, or connected to a biasing voltage source. The application of a bias between

electrodes

26 and 28 is somewhat optional. The bias electrodes have been found to be most helpful for slow operating speeds. A seal 30 is provided to prevent the developer particles from escaping through the bottom of the development apparatus housing and provides a means of holding the paper web 10 in intimate contact with the conductive electrode 28. The bias applied across the electrodes may vary normally vin the range from 0 to 500 volts with a potential on the order of 200 volts being preferred. Other potentials may be employed, however, since the potential is proportional to the type of developer being utilized, the electrode spacing, and the geometry of the develop- I ment apparatus 20.

The development apparatus 20 may comprise an I shell bulk cascade developer in which a carrier of Pyron iron powder or glass carrier beads is employed with toner. Toners which may also be utilized in the present invention are available from Xerox Corporation of Rochester, New York under the tradenames 914 Toner, Type 10 Toner, etc. and are made of insulating materials such as rosin, modified phenol formaldehyde, polystyrene and styrene methacrylate copolymer containing coloring material such as carbon black. The toners of this type are more fully described in US. Pats. No. 2,788,288, 2,89l,01l and US. Pat. No. Reissued 25,136 among others. After leaving the development apparatus 20 wherein the electrostatic image formed on paper 10 is developed, the paper enters a roll fuser 34 and is wound about a takeup roll 36 for storage. in the alternative, the paper 10 may be cut into strips of suitable length for the documents being produced. The paper may be moved through the charging station and developer at various rates ranging from 0.2 inches per second to 300 inches per second with rates on the order of 5 and 60 inches per second being preferred and inches per second giving very good results. lt should be noted that the paper 10 is both charged and developed while maintained in contact with a conductive electrode, whether the combination of backing electrode 12 and bias electrode 28 or backing electrode 12 alone when extended into-the development apparatus 20. The extension of a conductive electrode into the development apparatus 20 is believed to be a significant reason for the success of this system with ordinary paper. It has been found that if the paper is removed from the backing electrode before development, the charge on the top of the paper will disperse laterally as a result of the removal of the negative or opposite binding charges residing in the metal backing electrode and some of the charge will be neutralized by air breakdown at the separation. Thus, by extending a conductive electrode into the development apparatus this problem is avoided and the image may be developed so that the charges are neutralized by the toner particles and separation of the paper from the conductive electrode can be achieved without image destruction afterdevelopment. It has been noted that a 600 volt input on the stylus will give, for example, a 280 volt initial residual charge which will decay to something on the order of volts within 10 seconds. The decay takes place partly because of charges moving through the web and partially because of surface diffusion and lateral loss of charges on the surface of the paper. Even when the potential on the paper does not decay further the image continues to blur out rapidly. At slow operating speeds this problem has been corrected by the application of a desiccant, such as dry air or other suitable gas, by blower 18 across the surface of the charged paper to preserve image sharpness and intensity for a period as long as a minute. By use of this technique of blowing a desiccant across the paper it is possible to maintain a charge pattern of suitable quality for a far longer period than has been achievable at any time in the prior art although it is not necessary to do so unless it is desired to retain the charge prior to development for a period in excess of 10 seconds.

For while it was conventional in the prior art to predry the paper and to provide a desiccant around the paper before charging, the concept of blowing the desiccant across the paper in close proximity to the recording electrode and the actual deposition of charge is believed to be at least in part responsible for the drastic improvement in charge storage times obtainable, at slow operating speeds. By blowing the desiccant is meant the enclosing or surrounding of the paper with desiccant under a dynamic pressure differential, that is, at some overpressure so as to confine the desiccant in the region of the paper, thereby denying moist air to the paper. It is believed that the blowing of a desiccant across the charge inhibits the spread of the charge on the surface of the dried paper which was a major factor in the unsatisfactory results achieved in the prior art and has resulted in extending the time for which charge may be stored from times on the order of 10 seconds to times on the order of 1 minute. In order to provide for intimate contact between the printing electrode stylus and the recording surface, pressures in the range from about 2,000 pounds per square inch to about 3,500

pounds per square inch may be considered typical for most operations although higher and lower pressures may be utilized. It should be noted that a flexible conductive backing may be placed over the grounded backing electrode 12 for mechanical reasons i.e. for protecting the stylus from conforming to imperfections in the metal backing electrode 12. The paper roll 8, as set forth hereinabove, is maintained in a desiccated environment and should be located close to the charging station 16 to prevent the pickup of additional moisture by the paper prior to charging. Ordinary paper in a dried condition functions as a non-conductive dielectric charge retaining media and when pre-dried for 10 minutes at approximately 250 F, the surface resistivity is increased from on the order of 10 ohms per square centimeter to 10 to 10 ohms per square centimeter.

As has been noted hereinabove, the preferred embodiment utilizes metal contact styli in intimate contact with the surface of the paper. The contact stylus may be a single point electrode, an array of such electrodes and/or alphanumeric shaped character electrodes. Alternative methods such as the ion gun disclosed in US. application, Ser. No. 602,787, filed Dec. 19, 1966 now U.S. Pat. No. 3,495,269, assigned to the same assignee or one of the many TESI electrode means for transfer of electrostatic charge may be utilized at the charging station. It should be noted that by providing contact with a conductive electrode through the development zone a negative bonding charge, assuming an initial position charge is deposited on the surface of the paper, is provided in the electrode and neutralization of the charges by air breakdown and dispersion at separation are minimized. The application of a desiccant after the charging at slower speeds prevents the lateral dispersion of charge and results in its effective retention on the paper for a time sufficient to make the development on ordinary paper practical.

The structure of the backing electrode 12 and the development apparatus 20 can be varied in numerous ways a few of which will be illustrated by the alternative embodiments presented herein. These embodiments are merely exemplary and many other variations are possible within the scope and spirit of the present invention.

In the preferred embodiment, any suitable developer or toner may be utilized including but not necessarily limited to the toners referred to above.

The configuration of the development apparatus 20 is shown in FIG. 2. Paper 10 passes between plate electrodes 26 and 28 (or the portion of backing electrode 12 which extends into the development apparatus 20) which are separated by strips of insulating material 38. The latent electrostatic image is developed as it passes through the toner particles 24. The paper within the developing apparatus 20 is in contact with the grounded electrode 28. The paper 10 is held in contact with the grounded electrode 28 by the action of seal 30 which may be made from any suitable resilient material, such as foam rubber. It should be noted that the backing electrode 12 in FIG. 1 may be given in a curvature which would place a tension 11 the web material 10 resulting in more intimate contact between the backing electrode 12 and the paper 10. The grounded backing electrode 12 need not be a single plate of material as shown in FIG. 1 but be be a solid mass of material. Indeed, the only limitation on size is that it be large enough to constitute an adequate supply of electrons and that it acts as a true ground plane.

Going somewhat beyond this concept we have the embodiment of FIG. 3 in which, as described heretofore, paper web 40 is pulled off a supply roll 42 and brought into contact with a conductive belt 44 which is wrapped around a pair of

rollers

46 and 48 and provided with a curved radius by means of restraint and constraining elements so as to provide a close and intimate contact with paper web 40. The radius of the belt is indicated by 49.

The conductive belt 44 passes along with the paper web 40 past a seal 50 made of a suitable resilient material into development apparatus 52 which has a toner dispenser 54 mounted on one side and is composed of a pair of biased

plate electrodes

56, 58, separated by suitable insulative material. A suitable bias as described heretofore is provided by bias means applied to terminal 60. The web of paper 40 emerges from development apparatus 52 in contact with belt 44. It then passes into the roller fuser 62 and is then either cut into suitable sheets or rolled up on take-up roller 64. The curved grounded backing electrode 44 in the form of a belt provides for intimate contact as well as providing a means of moving the paper web 40 through the development apparatus to provide additional agitation of the toner. Furthermore, belt 44 may be made of a flexible conductive material or may be a flexible metal belt on the outside surface of which is coated a conductive backing layer as described in conjunction with the previous embodiment.

Another form of the present invention is shown in the alternative embodiment of FIG. 4 in which a paper web 66 is removed from a container roll 68, passed over an idler roller 70 and around a free-rotating grounded drum 72. A flexible conductive layer 73 may overlie the grounded drum 72 for mechanical reasons as set forth hereinabove. A charging station 74 is located past the point of tangency between the web 66 and drum 72 and is followed by development apparatus 76 containing toner particles 78. At slow speeds, a chamber containing a desiccant may surround paper web 66 in the interval between charging station 74 and development apparatus 76 to preserve the charge as set forth previously. The web 66 is thus in contact with the free-rotating drum 72 throughout its path from charging station 74 through the development apparatus 76. Development apparatus 76 may be any suitable development system such as fur brush, magnetic brush, or cascade development. After paper web 66 passes through the development apparatus 76 it passes through a roll fuser 82 and is either appropriately cut into segments or wound about a take-up roller 84.

Still another alternative embodiment employing the general principles described herein is shown in FIG. 5. In this embodiment, a backing electrode separate from the paper web is not necessary. Rather, in lieu of the use of a backing electrode in intimate contact during charging and developing, the paper web 86 after being removed from a storage roll 88 is passed over a liquid applicator brush 90 which applies conductive liquid to the backside of the web 86 just before it reaches charging station 92. The liquid applicator dips into a container of conductive liquid 94 as it rotates and thus brings the liquid into contact with web 86. It is important that the rate or rotation of the liquid applicator brush 90 be adjusted to apply only a sufficient amount of liquid to the web 86 so that the liquid will not penetrate to the top surface of the paper before the development is complete.

It is obvious that this adjustment depends upon the rate of speed of movement of the paper through the charging and development station. By applying the conductive liquid 96 to web 86, before the charging at charging station 92, the charges in the ground plane of roller 98 are able to migrate effectively to the paper web 86. At slow paper speeds, after charging a desiccant is blown across the charged paper web from a blower 102 and is continued until the web 86 enters the development apparatus 104 through seal 107.

The development apparatus 104 may have a bias placed across its

plate electrode members

106 and 108 by applying a bias to terminal 110. Upon completion of the developing process the paper web 86 passes through a roll fuser 112 and is then either cut into appropriate lengths or wound up on take-up reel 114. It should be noted that depending upon the configuration of the rollers with respect to the charging station and development apparatus it may be necessary to provide a twist through web 86 to insure that the proper side of the web 86, namely, the side opposite that which receives the charge at the charging station 92 receives the liquid 96 from applicator brush 90. It should be noted further that in this configuration after charge is applied it is possible to leave or to separate the conductive liquid layer, or backing electrode, and the paper web if the back of the paper web remains wet with the liquid applied by applicator brush 90. This is because the liquid 96 applied in effect transforms the paper web 86 into a temporary electrographic paper with an electrode capable of supplying electrons and bonding the charge to the paper until it is adequately developed. In the preferred embodiment any suitable material such as water which exhibits the property of being a conductive material at potentials on the order applied at the charging station may be employed. Salt solutions and similar materials may be considered to be typical materials in addition to water which would be suitable for use as the liquid 96.

Another alternative embodiment-is shown in FIG. 6. This embodiment features on-line drying and fusing. Paper web 122 initially stored on roll 120 is passed into the on-line drying and fusing unit 124 in which a continuous overpressure of air or other suitable desiccant is maintained. Heater elements 126 are provided to assist in the drying process. As the air picks up moisture from the web 122 it is exhausted through orifice 128. A gas flow of 2-3 cubic feet per minute through dryer 124 has been found sufficient for a paper speed of inches per second. Other flow rates may be utilized for different paper speeds. Having been conditioned by the pre-drying unit, web 122 passes over roller 130 into tangential contact with conductive backing roller 134. The stylus 132 may consist of a single electrode, a pin electrode array or an array of alphanumeric shaped character electrodes. The stylus is pulsed appropriately to deposit the desired charge pattern on web 122. While still in contact with the conductive backing roller 134, web 122 is passed into developer unit 138 where it comes in contact with developer 140. The developer unit 138 may be of any suitable type and configuration in addition to that shown in FIG. 6. Following development, the web 122 passes over guide roller 142 and into the on-line drying-fusing unit 124 again to fuse the developed image. The heat from heater elements 126 is sufficient to fuse the developed image at the paper speed for a given configuration. Variations in configuration may be utilized to increase the path length of web 122 in the fusing unit 124 if necessary for higher paper speeds. Additional fusing techniques may be employed within the on-line drying-fusing unit 124 to produce fusing as desired. Following fusing, the image on web 122 may be stored on take-up reel 144 or may be cut into sheets of appropriate lengths, as desired. The use of the same heat to dry (or pre-dry) the web and to fuse the developed image in an on-line configuration provides a design which is economical simple and reliable.

Thus, in operation, the charge applied on a paper web by contact stylus means is maintained on the web until it is completely developed by maintaining the paper web in intimate contact with a source of electrons (that is, with a conductive backing electrode). At lower paper speeds, the charge is additionally maintained for long periods by blowing a desiccant over the charge in the interval between the charging station and the development station. Development may be facilitated by the biased electrodes which result in a more effective deposition on developer powder on the charged areas. It should be noted that the developer systems described herein are not necessarily limited to development of charge patterns on ordinary paper but may be utilized to develop charge patterns on electrographic paper or on any other treated paper. a

While the invention has been described with reference to its preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the true spirit and scope of the'invention. In addition, many modifications may be made to adapt a particular situation or material to the teaching of the invention without departing from its essential teachings.

What is claimed is: I

1. Apparatus for recording electrostatic charge images on a substrate of ordinary paper comprising:

a. means for developing an electrostatic charge image formed on a substrate of ordinary paper, means for depositing an electrostatic charge image on said ordinary paper substrate, said depositing means being positioned to receive said ordinary paper substrate prior to said developing means, and

c. an electrically conductive electrode in contact with said ordinary paper substrate on the side opposite said depositing means and extending to said developing means.

2. The apparatus as defined in claim 1 wherein said electrically conductive electrode extends into said developing means.

3. The apparatus as defined in claim 1 further including means to enclose said paper between said depositing means and said developing means in a chamber containing a desiccant whereby the dissipation of said deposited electrostatic charges developed is minimized.

4. The apparatus as defined in claim 1 further including means to apply a conductive liquid to the backside of said paper to wet said paper part way through prior to depositing said electrostatic charge on said paper, said liquid applicator means being positioned with respect to said depositing means and developing means so that said liquid has time to migrate only part way through said paper prior to image development.

5. The apparatus as defined in claim 1 wherein said electrically conductive electrode comprises a rotatable prior to being grounded metallic drum.

9. The apparatus as defined in claim 8, said contact stylus produces a pressure on said paper in the range from about 2,000 pounds per square inch to about 3,500 pounds per square inch.

10. The apparatus as defined in claim 1 further including a means for drying said paper positioned along the path of paper flow prior to said depositing means.

11. The apparatus of claim 10 wherein said drying means further includes means to fuse the developed image following the passage of said paper through said developing means.

12. A method of recording electrostatic charge images on a substrate of ordinary paper comprising the steps of:

a. depositing electrostatic charge images on said ordinary paper substrate, and

b. providing an electrically conductive electrode in contact with said ordinary paper substrate from the time said electrostatic charge images are deposited thereon until said images are developed.

13. The method of claim 12 further including the step of directing a flow of desiccant over said deposited electrostatic charge images from the time of deposition until said images are developed.

Claims

1. Apparatus for recording electrostatic charge images on a substrate of ordinary paper comprising: a. means for developing an electrostatic charge image formed on a substrate of ordinary paper, b. means for depositing an electrostatic charge image on said ordinary paper substrate, said depositing means being positioned to receive said ordinary paper substrate prior to said developing means, and c. an electrically conductive electrode in contact with said ordinary paper substrate on the side opposite said depositing means and extending to said developing means.

3. The apparatus as defined in claim 1 further including means to enclose said paper between said depositing means and said developing means in a chamber containing a desiccant whereby the dissipation of said deposited electrostatic charges prior to being developed is minimized.

5. The apparatus as defined in claim 1 wherein said electrically conductive electrode comprises a rotatable grounded metallic drum.

6. The apparatus as defined in claim 1 wherein said developing means comprises a pair of opposed parallel plate electrodes separated by insulating members, said plate electrodes and said insulating means forming a chamber-like structure containing development powder and biasing means for applying an electrical field across said paper and powder as said image carrying paper passes through said chamber-like structure.

7. The apparatus of claim 1 wherein said electrically conductive electrode comprises a flexible conductive belt.

8. The apparatus as defined in claim 1 wherein said depositing means comprises a contact stylus.

12. A method of recording electrostatic charge images on a substrate of ordinary paper comprising the steps of: a. depositing electrostatic charge images on said ordinary paper substrate, and b. providing an electrically conductive electrode in contact with said ordinary paper substrate from the time said electrostatic charge images are deposited thereon until said images are developed.