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Publication numberUS3263604 A
Publication typeGrant
Publication dateAug 2, 1966
Filing dateJan 12, 1962
Priority dateJan 12, 1962
Publication numberUS 3263604 A, US 3263604A, US-A-3263604, US3263604 A, US3263604A
InventorsDalton Harold R
Original AssigneeTimefax Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Electro-responsive blanks
US 3263604 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

Aug. 2, 1966 H. R. DALTON 3,263,604


This invention relates to electro-responsive blanks, and more particularly it relates to blanks of the kind which respond at localized areas to the action of an electric discharge or flow of an electric current thereat.

A principal object of the invention is to incorporate in sucha blank a chemical or chemicals which improve the character and resolution of the recordings and the recording process generally.

Another principal object is to improve the responsiveness while substantially reducing undesirable effects which are ordinarily associated with the recording on the blank at localized areas which are subjected to relatively high temperatures as a result of the electric current or discharge. Thus, burning or disintegration in the localized areas of the blank or of one or more coatings on the blank by the recording currents takes place.

Various forms of so-called facsimile or similar electroresponsive recording blank-s have been proposed heretofore wherein the responsiveness of the blank is predicated upon the incorporation in the blank, either in the body thereof or as a coating thereon, a conductive ingredient such as conductive powdered carbon or other ingredients which decompose atelevated temperatures. Typical of such blanks are those disclosed in my prior Patents No.

2,554,017, No. 2,664,043 and No. 2,664,044. Other blanks of that general kind have been proposed wherein the electric recording current or potential produces 'an arc, spark or other similar heat developing current flow,

usually in the form of a disruptive discharge at localized areas on the blank surface. In all those prior blanks, the existence of the discharge results in a burning or disintegration of the blank or of one or more of its coatings at the localized areas. This results in a number of undesira ble conditions during the recording. Among those conditions are the following: the liberation of gasses and odors; the liberation of burnt products which tend to accumulate on the recording electrode especially when such electrode is in the (form of an energized stylus or needle point; the liberation of smoke which tends to leave a deposit on the surface of the recording blank itself, as well as upon other parts of the associated recording equipment. The liberation and deposition of these disintegration or contamination products on the blank gives the surface an unpleasant appearance, and handling of the blank after recording is messy since the deposit is likely to be transferred to the hands.

During the break-down or disintegration of the constituents in the recorded areas of the blank, whether it occurs merely at the surface of the blank as in Patent No. 2,554,- 017, or whether it results in perfioration of the blank as in Patent No. 2,664,043, the decomposition products depend to a large extent upon the materials incorporated in the recording blank or sheet. These products may be either in the body of the blank or backing or in the coating or coatings on such backing. They are also a function of the heat attending the passage of electric current into and through the blank, as well as upon the material of the recording electrode, such for example as the usual recording stylus or needle point electrode.

divided conductor such as carbon or the like, it is necessary in formulating the coating-s to employ a binder, usually a resin binder, so that the coating can be applied as a homogeneous continuous smooth surfaced film. In such cases the decomposition products attending the recording electric discharge contain with-in the smoke or fumes decomposition products of the resin binder. If the backing is of paper or fibrous composition, additional chemical or fibrous decomposition products may be liberated, Among the various decomposition products that may be liberated are resin monomers, aldehydes, esters, acids, etc., as well Some of these d eas carbon, metallic compounds, etc. composition products may collect upon the recording'stylus and frequently cause poor or intermittent recordings and at times may completely insulate the stylus against recording or they may even ground or short circuit the stylus. This is particularly true where the stylus assembly consists of a multiplicity of adjacent needle-pointed elements. The presence of acid decomposition products are particularly objectionable because they cause corrosion of the adjacent parts of the recording mechanism. These difficulties are particularly disturbing wherethe recording blank is of the so-called dry blank or paper kind as distinguished from the well known electrolytic or moist blank kind. In some cases, the presence of these disturbing conditions has been so great that special vacuum discharge (ventilating or filtering) equipment may be required, as

disclosed for example in US. Patent No. 2,706,672,

granted April 19, 1955.

Therefore, a feature of the invention relates to a recording blank which is capable of being recorded on by an electric discharge, but without producing undesirable quantities of odors, deleterious smoke or undesirabledecomposition products.

Another feature relates to the incorporation into the blank or into one or more coatings or layers thereon a metallic peroxide or dioxide which, during the recording of the blank, greatly reduces or eliminates substancesfrom the decomposition products that tend to collect" on the recording stylus which would otherwise interfere with the accuracy and resolution of the recorded subject matter. I i

A further feature relates to the novel organization and chemical composition of an electro-sensiti-ve recording blank whereby more reliable recordings are obtained without subjecting the recording equipment to contamination by disintegration or liberated products which tend to resuit from the recording currents.

Other features and advantages not specifically enumerated will be apparent from aconsideration of the following detailed descriptions, the appended claims and the attached drawing.

In the drawing, 2 l 1 FIG. 1 shows one form of electrically inscribable cording blank accordingrto the invention;

'tF-IGS. 2 through 7 show modifications. of the blank of FIG. 1.

It has been found that the desirable results of the invention can be achieved by incorporating the record- Patented August 2, 1966 -In the case of coated blanks where one or more of the coatings include a finelying medium or blank a quantity of the peroxide of calcium, barium, strontium, cadmium or zinc; or of the dioxide of manganese or lead. These peroxides or dioxides can be used either singly or in combination as found most desirable. In certain cases it is desirable to employ peroxides which are white in color. Amongst such peroxides are the following: calcium peroxide, barium peroxide, strontium peroxide, cadmium peroxide, zinc peroxide. If a black or blackish effect is desired in a coating, manganese dioxide or lead dioxide may be used.

One kind of dry electric recording blank embodying the invention may comprise a backing or web of paper which is rendered electrically conductive to a predetermined degree by incorporating in the paper itself, as for example during the paper manufacture, a conductive material such as powdered carbon black or graphite, and to which paper a whitish masking coating is applied. In another kind of blank the backing is of non-conductive paper which has a conductive coating applied thereto. In the well known manner, this masking coating is removed in localized areas in response to applied electric signals so as to expose the black paper surface. During this re-- cording action, which is attended usually by a spark or space discharge or similar disruptive discharge, the break-down of the coating results in the production of smoke which contains appreciable quantities of undsirable materials. By incorporating a quantity of one or more of the anti-contaminant oxides above mentioned, either in the coating or in the body of the paper itself, or in both, the objectionable ordors and undesirable decomposition products can be greatly reduced in accordance, of course, with the amount of such peroxide or dioxide material that is added.

Referring to FIG. 1, there is shown a typical recording blank which consists of a non-conductive paper backing 10 to which is applied a film 11, for example consisting of conductive powered carbon or graphite homogeneously distributed through a plastic binder. This binder is usually of the film-forming type. The thickness of the dry coating may be approximately 0.0001 inches to 0.005 inches for a recording voltage of, for example, 200-300 volts. Superimposed on the conductive film 11 is a whitish masking coating 12. This coating should be of minimum thickness consonant with the required masking of the dark or blackish film 11. For a detailed description of typical formulations for the film 11 and masking coating 12, reference may be had to any of the above noted patents. Heretofore the masking coating 12, in order to have the desired whitish masking quality consonant with its disintegrating responsive to an electric discharge applied to the blank, for example across electrodes 13, 14, schematically shown in the drawing, has usually been formed of a zinc oxide, zinc sulfide or similar whitish pigment. However, where the whiteness of the coating 12 is to be preserved,-the usual whitish pignment in that coating can, in accordance with the invention, be replaced in whole or in part by zinc peroxide or any of the other peroxides above mentioned or by any mixture thereof. The invention is not limited to any particular proprtion of the said peroxides in the masking coating. It has been found that a replacement of the conventional whitish pigment used in the white masking coating with as little as percent of any of the above noted peroxides is efiective.

It has also been found that by incorporating either the peroxides or dioxides in the blackish conductive film 11 together with the usual carbon black therein, the desired conditions are obtained. In other words, when either or both of the coatings 12 or 11 are disintegrated by the electric discharge, the presence of any of the above peroxides or dioxides in either or both of those coatings reduces the undesirable effects above mentioned.

It will be understood, of course, that the blank need not uncessarily have a top whitish masking coating 12. Thus, as shown in FIG. 2, the blank may comprise the non-conductive paper backing 10 with a film coating 11 of powdered conductive carbon in a resin binder. In that case, since the whiteness of the exposed surface of the blank is not of importance, the above noted peroxides or dioxides may be incorporated into the batch which forms the film coating 11. It will be understood that the invention is not limited to the conductive film or coating 11 being rendered conductive by the incorporation of powdered carbon. It may comprise coatings which are rendered conductive by the incorporation of powdered metal, or it may take the form of a vacuum-deposited material, such as metal or carbon, which is of a color or hue contrasting either with the masking coating 12 (FIG. 1) or with the paper backing 10. In either of the examples of FIGS. 1 and 2, since the backing is non-conducting, the conducting layer 11 in each case acts as the plate of a condenser, andrecording is usually accomplished by subjecting alternate currents across the electrodes 13, 14.

FIG. 3 shows the invention as embodied in a blank wherein the backing 10a consists of a conductive material such as paper which, during its manufacture or otherwise, has homogenously distributed throughout the body thereof a powdered conducting material such for example as powdered metal, carbon or graphite. The white masking coating 12 containing any of the above noted peroxides is applied directly to the conductive backing 10a. Uusually in this type of blank the conductive paper backing 10a contains approximately 10 percent to 30 percent by weight of carbon black. Therefore, the incorporation of any of the above peroxides and especially of the dioxides, for example in proportion of 10 percent to 20 percent of the dioxides (based on the weight of the fibers present in the backing 10), is eflective in reducing odor, styles contamination and acidity in the liberated smoke. If both the paper 10a and the masking coating 12 contain a peroxide or dioxide above mentioned, the reduction of the undesirable effects is more readily observable. It will be clear that the use of manganese dioxide or lead dioxide in the white coating 12 would detract from its whiteness and, therefore, the white peroxides are preferred for use in the white or light colored coatings. However, any of the mentioned peroxides o-r dioxides may be used in the black electrically conducting paper 10a or in any of the black electrically conducting coatings (such as coating 11 of FIG. 2) or any other black electrial conducting coating or paper well known in the manufacture of electro-responsive stencils, printing plates or blanks.

FIG. 4 shows another form of blank wherein the backing 10 is of non-conductive material such as paper or other fibrous stock to which is applied two or more graded coatings 11a 11b, each containing for example powdered conductive carbon homogeneously dispersed in a resin binder, and over the coating 11b is applied the whitish masking coating 12. For a detailed description of the manner of formulating and applying the coatings 11a and 11b, reference may be had to US. Patent No. 2,664,044. Here again any one or all of the coating 11a, 11b and 12 can, according to the invention, include one or more of the peroxides or dioxides above mentioned.

Preferably the dioxides are used in the coatings 11a and 11b and the peroxides are used in the masking coating 12.

The invention is also applicable to recording or electrically inscribable blanks which not only make a visual record of the recording currents but which also can be used as stencil masters. Thus, in FIG. 5 the backing 10 may be of non-conductive paper or other fibrous stock to which is applied in a readily strippable manner, so as to be adherent thereto with a low degree of afiinity, an electrically conductive plastic film 15 such for example as described in US. Patent No. 2,664,043. The film 15 may or may not be provided with an additional masking coating 12 of a white or contrasting color with respect to film 15. Either the coating 12 or the film 15 may also have incorporated therein one or more of the above mentioned anti-contaminants.

FIG. 6 shows the invention embodied in a blank which is not only capable of being electrically inscribable to record electric signals but also, after such recordings, the blank is capable of being used as a lithographic or planographic master. In this embodiment the backing 10 may be either of conductive or non-conductive paper or even of metal. The backing 10 is provided with a conductive coating or film 11 or a graded conductive coating such as 11a, 11b of FIG. 4. On top of the coating 11 is applied a masking coating 12a which has been rendered hydrophi-lic but water insoluble, as described for example in my prior application Serial No. 445,615, filed July 26, i

1954. In this embodiment either the backing 10, the coating 11, or the coating 12a, or all of them, may contain one or more anti-contaminants above mentioned.

It will be understood, of course, that the invention is not limited to the application of any of the above mentioned coatings to the backing 10 in a manner permanently bonding them to the backing. For example, as shown in FIG. 7, the backing 10, which may be of either conductive or non-conductive material, may have its surface 16 rendered hydrophilic but water insoluble in any well known manner, for example as described in application Serial No. 445,615, filed July 26, 1954, or in British Patent No. 774,702. On the surface 16 there is applied a strippable sheet consisting of a conductive plastic film having permanently bonded thereto the whitish masking coating 12. When the recording potentials are applied -by means of the stylus 13, there results a perforation of the composite unitary sheet formed of the coatings 12 and 15, which composite sheet can then be readily stripped from the backing 10 to form a duplicating stencil. In this embodiment either the film 15 or the masking coating 12 or both may have incorporated therein any of the above noted anti-contaminants.

During the recording operation on any of the blanks above mentioned containing the peroxides or dioxides as above mentioned, these peroxides or dioxides break down and immediately become highly effective oxidizing agents to oxidize effectively the decomposition products of the recording medium, resulting in less odor, less free carbon, acid constituents, etc., in the liberated smoke.

As hereinabove pointed out, the black conducting coating in any of the examples mentioned may be either a single or multiple layer coating and either of uniform or graded transverse conductivity. The carbon in these conductive coatings may range from approximately 15 percent to 50 percent by weight of the total solids present. An equal weight of any of the peroxides or dioxides above mentioned may be added to these coatings to produce the desired effects. In the case of the whitish masking coatings which are usually of the same general composition consisting of a white pigment, such as zinc oxide, zinc sulfite, titanium dioxide, copper thiocyanate, etc., held in a resinous binder, replacement of a portion of the white pigment with as little as 5 percent to as much as 100 percent by the peroxide or mixture of peroxides above mentioned is effective according to the invention.

Thus, in the example shown in FIG. 1, the backing 10 may be of paper or similar fibrous stock of the desired thickness. The coating 11 may be of any of the formulations such as disclosed for such coatings in US. Patent No. 2,664,044, and likewise for'the masking coating 12. While the drawing shows in schematic form a pointed stylus electrode 13 which is arranged to scan the blank in a point-by-point succession, it will be understood that any other form of recording electrode may be used as is well known in the facsimile recording art. While in the drawing the numeral 14 represents the usual metal scanning drum or platen upon which the blank is mounted for the scanning operation, it may take the form of the well known helix rib which cooperates with a conductive intersecting straight edge electrode to define the successive 6 elemental scanning points. It will also be understood that in the form of blank shown in FIGS. 5 and 7 where a non-conductive backing 10 is used and provided with an intermediate conductive strippable plastic film, the

. recording current return for the electrode 13 may be made by providing a suitable contact element engaging the edge or other convenient part of the conductive film. In the manner well known in the facsimile recording art, the recording current or voltage applied to the blank can be chosen to disintegrate either the top or masking coating alone, or also part or all of the intermediate conductive coating at the minute or elemental areas beneath the point of the recording electrode 13.

Various changes and modifications may be made in the disclosed embodiments without departing from the spirit and scope ofthe invention.

What is claimed is: I

1. An electrosensitive recording blank which is conductive at least in part of its thickness, said blank including a normally stable compound chosen from the group consisting of the peroxides of the metals calcium, barium, strontium, cadmium, zinc and manganese which when subjected to the heat of the recording currents releases oxygen to reduce the contamination which tends to occur by the recording current passing through the blank.

2. An electrosensitive recording blank of the kind which is electrically conductive and which is designed to have part or all of its thickness disintegrated in signal-controlled elementally scanned areas and which tends to produce contaminating disintegration products when subjected to electric discharge at said areas, said blank including a compound chosen from the group consisting of the peroxides of the metals calcium, barium, strontium, cadmium, zinc and manganese and from which oxygen is released by the heat of the recording currents and reacts under the recording conditions with said disintegration products to neutralize their contaminating effect.

3. An electrosensitive blank according to claim 2 in which the blank has a backing of electrically con-ductive material.

4. An electrosensitive blank according to claim 2 in which the blank has a backing of non-conductive material having an electrically conducting coating applied to at least one surface thereof.

5. An electrosensitive blank according to claim 2 having a backing which is conductive by inclusion of powdered carbon, and at least one face of the backing has a coating which is disrupted by applied electric discharge.

6. An electrosensitive recording blank according to claim 5 in which the backing is of non-conductive paper having a base coating of powdered conductive carbon in a film-forming resin binder, and a whitish top masking coating which includes said compound.

7. An electrosensitive recording blank according to claim 5 in which the backing is of paper having an electrically conductive film strippably attached thereto and arranged to be perforated by electric discharges applied thereto and which tends to produce contaminating disintegration products accompanying said perforation, said film having said compound incorporated therein.

8. An electrosensitive recording blank according to claim 2 having a backing with a surface which is hydrophilic but water insoluble and which is receptive to lithographic ink only in those areas which are subjected to the recording electric discharge.

9. An electrosensitive recording blank according to claim 2 having a paper backing whose surface is hydrophilic but water insoluble and which is receptive to lithographic link only at those areas which are subjected to the recording electric discharge, and a conductive plastic film strippably attached to said hydrophilic surface, said film being perforatable by the electric discharge to render only said areas receptive to lithographic link.

10. A coating material for electrosensitive recording blanks of the kind which are arranged to be acted upon in suocessivescanned areas by an electric discharge which tends to produce contaminating disintegration products, and comprising powdered material in a film-forming binder and also a peroxide chosen from the group consisting of the peroxides of the metals calcium, barium, strontium, cadmium, zinc, manganese and lead.

11. A light colored electrosensitive coating for electrically inscribable blanks, comprising a peroxide chosen from the group consisting of the peroxides of the metals calcium, barium, strontium, cadmium, zinc, manganese and lead, together with a whitish masking pigment and a film-forming binder.

12. An electrosensitive coating for electrically inscrib- 15 a film-forming binder and also including a peroxide chosen from the group consisting of the peroxides of the metals calcium, barium, strontium, cadmium, zinc andmanganese.

References Cited by the Examiner UNITED STATES PATENTS 2,294,149 8/ 1942 Kline et a1. 101426 2,310,946 2/ 1943 Finch 101426 FOREIGN PATENTS 774,702 5/ 1957 Great Britain.

DAVID KLEIN, Primary Examiner.

WILLIAM B. PENN, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO. 3,263,604 August 2, 1966 Harold R. Dalton It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 30, for "ordors" read odors line 50, for "responsive" read responsiveness H line 60, for "proprtion" read proportion line 74, for "uncessarily" read necessarily column 6, line 71, for "link" read ink line 75, for "link" read ink Signed and sealed this 1st day of August 1967.

(SEAL) Attest:

EDWARD M. FLETCHER, JR. EDWARD J. BRENNER Attesting Officer Commissioner of Patent

Patent Citations
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US2310946 *Apr 7, 1939Feb 16, 1943Finch William G HFacsimile recording paper
GB774702A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3363261 *Jul 30, 1965Jan 9, 1968Motorola IncPrinting device
US3789425 *Jun 9, 1972Jan 29, 1974Colorfax Co LtdElectro-sensitive recording medium having a plurality of recording layers
US3898672 *Jun 10, 1974Aug 5, 1975Ricoh KkElectrosensitive recording member
US3904752 *Nov 6, 1973Sep 9, 1975Fuji Photo Film Co LtdDischarge recording
US3920873 *Nov 9, 1973Nov 18, 1975Diamond Arthur DElectrosensitive recording media
US4046928 *Jan 8, 1973Sep 6, 1977Xerox CorporationElectroresistive paper
US4086853 *Jul 13, 1976May 2, 1978Vickers LimitedLithographic printing plate preparation
US4275092 *May 15, 1979Jun 23, 1981Kansai Paint Co., Ltd.Method for producing a plate or sheet useful in planographic printing
US4319255 *Dec 14, 1979Mar 9, 1982International Business Machines CorporationTinted metallized recording medium
US4322469 *Nov 14, 1980Mar 30, 1982Xerox CorporationElectrostatic recording medium
US4608102 *Nov 14, 1984Aug 26, 1986Omark Industries, Inc.Primer composition
US4836106 *Oct 30, 1987Jun 6, 1989International Business Machines CorporationDirect offset master by resistive thermal printing
US5052292 *Jan 18, 1991Oct 1, 1991Presstek, Inc.Method and means for controlling overburn in spark-imaged lithography plates
US5165345 *Feb 25, 1991Nov 24, 1992Presstek, Inc.Lithographic printing plates containing image-support pigments and methods of printing therewith
US5249525 *Jun 5, 1992Oct 5, 1993Presstek, Inc.Spark-discharge lithography plates containing image-support pigments
EP0501065A1 *Oct 15, 1991Sep 2, 1992Presstek, Inc.Lithographic printing plates containing image-support pigments
WO1991004154A1 *Sep 21, 1990Mar 22, 1991Presstek IncMethod and means for controlling overburn in spark-imaged lithography plates
WO1991008108A1 *Nov 26, 1990May 29, 1991Presstek IncLithography plates and method and means for imaging them
U.S. Classification101/462, 430/259, 358/1.9, 101/467, 430/84, 346/135.1
International ClassificationB41C1/10
Cooperative ClassificationB41C1/1033
European ClassificationB41C1/10A4