JPH0473386B2 - - Google Patents

Abstract

A method and system for high speed image reproduction by electro-coagulation of an electrolytically coagulable colloid. A plurality of negative and positive electrolytically inert electrodes (12, 14) which are electrically insulated from one another are arranged to define a matrix of dot-forming elements (16), the negative and positive electrodes of each matrix element having respective planar active surfaces with the negative electrode active surface extending in the same plane as the positive electrode active surface and in close proximity thereto. A layer of substantially liquid colloidal dispersion is applied over the electrode active surfaces of the matrix elements (16), the colloidal dispersion containing an electrolytically coagulable colloid, a liquid dispersing medium and a soluble electrolyte, and having a substantially uniform temperature throughout the layer. The negative and positive electrodes (12, 14) of selected ones of the matrix elements (16) are electrically energized to cause selective coagulation and adherence of the colloid onto the positive electrode active surfaces of the selected matrix elements and to thereby form a series of corresponding dots representative of a desired image, and any remaining non-coagulated colloid is thereafter removed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method for high speed image reproduction. More particularly, the present invention relates to an improved method and apparatus for image reconstruction by electrocoagulation of electrolytically coagulable colloids.

Applicant issued U.S. Patent No. 1, July 1, 1975.
No. 3,892,645, a thin layer of a liquid composition comprising a colloid such as gelatin or albumin, water and an electrolyte is disposed between at least one pair of spaced opposing cathodes and anodes and filled with the liquid composition. Describes an electroprinting method and device that appears to have a large gap. In one embodiment, there is a plurality of electrically insulated cathodes in a row, selected ones of which are energized to pass electrical pulses through the layer at selected points, so that each energy source is Selective coagulation of the colloid is caused to deposit dot by dot on the anode directly against a given cathode, forming a trace.

It is very important that the gap between the cathode and anode be uniform throughout the electrode active surface. Otherwise, there would be a change in layer thickness and therefore a corresponding change in electrical resistance at different locations between the electrodes, which would result in a non-uniform image since the coagulated colloid thickness is proportional to the amount of current passing through the layer. This is because it becomes a rebirth. Since the gap is approximately 50μ, it is extremely difficult to adjust its uniformity. Further, if the cathode is energized more than once during image reproduction, these polarize and cause gas generation and accumulation at the cathode, which adversely affects image reproduction.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to overcome the above-mentioned drawbacks and to provide a method and apparatus for image reconstruction by electrocoagulation of colloids that does not require precise adjustment of the electrode gap or cause electrode polarization that interferes with image reconstruction. .

According to one aspect of the invention, (a) a number of electrolytically inert cathodes and anodes are provided, electrically insulated from each other and arranged in a matrix of point-forming elements, provided that The cathode and anode of are each composed of first and second sets of strip-shaped electrode parts arranged in parallel and electrically insulated from each other, and the cathode part of the first set is arranged in the lateral direction of the anode part of the second set. formed of a number of protruding conducting portions extending and spaced apart along their length and having flat active end faces, each protruding portion of said cathode portion passing through a corresponding hole in said anode portion. the flat active end surface of each of the protrusions and the flat active surface portion of each of the anode portions adjacent to each of the holes extend substantially in a common plane and terminate flatly to form the matrix element; (b) applying a layer of substantially colloidal dispersion on the cathode and anode active surfaces of said matrix element;
In this case, the cathode and anode active surfaces are on the same side of a colloidal dispersion layer, said colloidal dispersion containing an electrolytically coagulable colloid, a liquid dispersion medium, and a soluble electrolyte and having a substantially uniform temperature throughout said layer. (c) applying an electric field extending between the cathode and anode of selected ones of said matrix elements substantially parallel to the flat active surfaces of said cathode and anode to continuously energize the electrodes of one set; and at the same time energize selected electrode sections of the other set to cause selective coagulation and deposition of the colloid on the anode active surface of the selected matrix element. Electrocoagulation of coagulable colloids by electrolysis, characterized by the steps of forming a series of corresponding points representing the desired image, and (d) removing remaining uncoagulated colloids. An image reconstruction method is provided. According to another aspect of the invention, a plurality of electrolytically inert cathodes and anodes electrically insulated from one another and arranged in a matrix of dot-forming elements, each of the cathodes and anodes being The first of the strip-shaped electrode parts arranged in parallel and electrically insulated from each other.
and a second set, the cathode sections of the first set extending laterally of the anode sections of the second set and spaced apart along their length, each having a flat active end surface. The protruding parts of each of the cathode parts form a protruding conductive part through the corresponding hole in the anode part, and the protruding part of each of the cathode parts connects the flat active end surface of each of the protruding parts to the flat active end surface of each of the anode parts adjacent to each of the holes. active surface portions extending substantially in a common plane and terminating in the matrix element; suitable for receiving a layer of a substantially colloidal dispersion having a substantially uniform temperature throughout the layer; and applying electrical energy to the cathodes and anodes of selected ones of said matrix elements. means for causing selective coagulation and deposition of said colloid on the anode active surface to form a series of corresponding points representing a desired image, said member sequentially energizing one set of electrodes and the other set; An image reproducing device by electrocoagulation of a colloid that can be coagulated by electrolysis is provided, characterized in that it comprises: an electric energy application means comprising a member that simultaneously applies energy to selected ones of the electrodes;

Therefore, according to the invention, the active surfaces of the cathode and anode are no longer in different planes, but rather extend in substantially the same plane, so that it is no longer necessary to precisely control the thickness of the applied colloidal dispersion layer. There isn't.
Further, since the electrodes of the matrix elements for forming each point are given energy once for image reproduction, there is barely any electrode polarization, and gas accumulation occurs which hinders image reproduction.

In a preferred embodiment of the invention, the cathode and anode of the matrix each comprise first and second sets of strip-shaped electrodes arranged in parallel and electrically insulated from each other, the cathode portion of the first set being connected to the cathode of the second set. It extends laterally to the anode portion of the anode and is made up of a number of protruding conductive elements spaced apart along its length, each having a planar active end surface. The protrusion of each cathode section extends through a corresponding hole formed in the anode section so that the planar active end surface of each protrusion and each anode section and planar active surface portion near each hole extend substantially into a common plane. It ends flat to form a matrix element. Therefore, electrically energizing the cathodes and anodes of selected matrix elements can be achieved by successively energizing one set of electrodes and simultaneously energizing selected ones of the other set of electrodes. I can do it. It is preferable to apply energy to selected cathode sections simultaneously while applying energy to the anode section sequentially.

Simultaneous selective energy injection of other sets of electrode sections can be conveniently accomplished by sweeping the electrode sections and delivering electrical pulses to selected ones in the meantime. This electrical pulse can vary in either voltage or time from one electrode to another so that the amount of coagulated colloid deposited on the anodic active surface of the selected matrix element varies accordingly. This can form points of altered intensity and thus reproduce halftone images.

Commonly used colloids have high molecular weight, i.e. approximately
10,000 to about 1,000,000, preferably 100,000 to about 1,000,000
It is a linear colloid with a high molecular weight of 500,000. Examples of suitable colloids include animal proteins such as albumin, gelatin and casein, vegetable proteins such as agar and synthetic copolymers such as polyacrylic acid, polyacrylamide, polyvinyl alcohol and their derivatives. Water is preferably used as the medium for dispersing the colloid to create the desired colloidal dispersion.

Colloidal dispersions also contain soluble electrolytes that make water highly conductive. It is believed that water moves towards the cathode under direct current, thus drying the colloidal dispersion and causing coagulation and deposition of the colloid on the anode. Examples of suitable electrolytes include chlorides and sulfates, such as potassium chloride, sodium chloride,
These include calcium chloride, nickel chloride, lithium chloride, ammonium chloride and magnesium sulfate.
Since the rate of electrocoagulation is temperature dependent, the layer of colloidal dispersion must be kept at a substantially constant temperature, for example using a thermostatic water jacket, for uniform image reproduction.

After coagulation of the colloid, the remaining uncoagulated colloid is removed by an appropriate method such as washing, blowing with air, or wiping to sufficiently reveal the coagulated colloid.

The application of the present invention is disclosed in Applicant's U.S. Patent No. 3,892,645.
It is basically the same as the place described in the issue. For example, coagulated colloids can be colored with hydrotapic pigments. The pigment is absorbed and the colored solidified colloid is transferred to an end use support such as paper. The solidified colloids can also be fixed or hardened chemically or by radiation, as used in offset graph printing.
It is also possible to produce solidified colloidal images of different colors which can be transferred onto the final use support in a double-baked state to produce multicolored images.

Further features and advantages of the invention will become readily apparent from the following description of preferred embodiments, as illustrated in the accompanying drawings.

FIG. 1 is a diagram of an image reproduction apparatus according to the invention, in which the matrix printer is shown partially cut away.

FIG. 2 is a fragmentary open view of the point matrix printer of FIG.

FIG. 3 is a cross-sectional view taken along line 3--3 of FIG.

FIG. 4 is another cross-sectional view taken along line 4--4 of FIG.

FIG. 5 is a top view of a matrix element of the point matrix printer shown in FIG.

FIG. 6 is the same diagram as FIG. 5, but shows a staggered matrix element.

The image reproduction device shown in FIG.
This is a dot matrix printer indicated by 0, and consists of two electrically insulated belt-shaped cathode parts 12 and anode parts 14, which are arranged in parallel and overlapped. There are a number of dot-forming matrix elements 16 extending perpendicularly to the anode section 14 and at their intersections. Each cathode section 12 is electrically swept
The sweeping device 18 is connected to a modulator 22 coupled to an electronic counter 24 which is operative to transmit electrical pulses to selected ones of the electrode sections 12 by the sweeping device 18 during sweeping. It is connected to the negative terminal of the DC power supply 20. A modulator serves to vary the electrical pulse either in voltage or time. On the other hand, each anode section 14 is connected to another sweeping device 18' which is electrically connected to the positive terminal of the power source 20. Therefore, the electrodes of selected ones of the matrix elements 16 are connected to the sweeping device 18'.
The device 18 continuously injects energy into the anode section 14 and at the same time sweeps the cathode section 12 to electrically energize it, while a counter 24 transmits electrical pulses to selected electrode sections 12 which are modulated. It is either voltage or time modulated by the machine 22.

As shown in Figures 2-4, the cathode sections are electrically insulated from each other by a layer of insulating material 26 approximately 10 microns thick. The cathode sections 12 are also electrically insulated from each other by a layer of insulating material 28 approximately 25 microns thick. Anode section 14 is similarly insulated by a layer 30 of insulating material about 10 to 25 microns thick, preferably 10 microns thick. Each cathode section 12 has a number of protruding conductive sections 32 of circular cross-section with respective planar active end faces 34 spaced along its length. The protrusion 32 of each cathode section 12 extends through a corresponding hole 36 in the anode section 14 such that the flat active end surface 34 of each section 32 and the flat active surface portion 38 of the anode section 14 near the hole 36 are in a common plane. It ends flat, as if stretching. Each protrusion 32 is of course electrically insulated from its adjacent anode section 14 by a layer of insulating material 40, such as silicon monoxide, having a thickness of about 5 to 10 microns, preferably 10 microns.

Thus, each flat surface 34 of each protrusion 32 and the flat surface portion 38 of each anode portion 14 adjacent to each portion 32 constitute an electrode active surface of each point-forming matrix element 16. Each matrix element is approximately
With a square surface area of 125 microns by 125 microns, the protrusion 32 of each matrix element 16 has a diameter of approximately 25 to 50 microns at its center. Therefore, the protrusion 32 is not visible to the naked eye. The dot matrix printer 10 consists of approximately 40,000 such matrix elements 16 per square inch.

Cathode section 12 can be made from any metal, but copper or stainless steel is preferred. However, the anode section 14 must be made of a metal that resists electrolytic attack and is electrically negative with respect to hydrogen, or a metal that promotes electrical coagulation, such as aluminum, nickel, chromium, or tin. The surface 38 of the anode section 14 may be unpolished to facilitate the deposition of solidified colloid thereon. The electrode portion 14 can be produced by ion sputtering, and is therefore approximately 10 μm thin.

To reproduce an image by a device such as the one described above, a layer of a colloidal dispersion containing a colloid such as gelatin or albumin, water and an electrolyte such as potassium chloride and having a substantially uniform temperature throughout the layer is dotted. It is attached to the front of the matrix printer 10.
Sweeping devices 18 and 18' and counter 24 are activated to apply electrical energy to the electrodes of selected ones of matrix elements 16, thereby selectively solidifying colloids on the anodic active surfaces 38 of selected matrix elements. The coagulated colloid 42 forms a series of corresponding points representing the desired image.

The layer of insulating material 30 between the anode sections 14 must be as thin as possible to avoid streaking creating a continuous image. The layer of insulating material 40 around each protrusion 32 must also be as thin as possible since the thinner it is, the faster the electrocoagulation rate is.

Instead of having matrix elements 16 each formed with a single central projection 32 as shown in FIG. Of course, it is also possible to make 16'. Such an arrangement allows image production with a more even tone distribution.

It has been determined that the force required to produce a coagulum on a square surface area of approximately 125 microns by 125 microns using the image reconstruction device described above is a capacitance load of 2 microfarads at 50 volts. In other words, approximately 100,000 points can be transferred per second using a 25 watt (50V, 500mA) generator.

Although the dot matrix printer 10 is shown as having a flat viewing surface, it is clear that the entire surface of the anode section 14 making up the viewing surface of the printer 10 need not be flat. However, the electrode active surfaces of each matrix element are planar and extend substantially in a common plane. Thus, for example, a cylindrical point matrix printer could be designed in which each matrix element would have the required properties described above.

[Brief explanation of drawings]

FIG. 1 is a diagram of an image reproduction device according to the invention, with a dot matrix printer partially cut away. FIG. 2 shows an expanded view of the point matrix printer of FIG. FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. FIG. 5 is a top view of a matrix element of the point matrix printer of FIG. 1. FIG. 6 is a top view of a different type of matrix element. Numbers in each figure: 10... dot matrix printer, 12... cathode section, 14... anode section, 30, 4
0... Insulating material, 32... Projection, 16... Matrix element for point formation, 18, 18'...
Sweeping device.

Claims (1)

Claims: 1. (a) A number of electrolytically inert cathodes and anodes electrically insulated from each other and arranged in a matrix of point-forming elements, provided that The cathode and the anode each consist of first and second sets of strip-shaped electrode parts arranged in parallel and electrically insulated from each other, and the cathode part of the first set extends in the lateral direction of the anode part of the second set. and formed of a number of protruding conducting portions spaced apart along its length and having flat active end faces, the protruding portion of each cathode portion passing through a corresponding hole in the anode portion. the flat active end surface of each protrusion and the flat active surface portion of each anode portion adjacent to each hole extend substantially in a common plane and terminate flatly to form the matrix element; b) applying a layer of substantially colloidal dispersion on the cathode and anode active surfaces of said matrix element;
In this case, the cathode and anode active surfaces are on the same side of a colloidal dispersion layer, said colloidal dispersion containing an electrolytically coagulable colloid, a liquid dispersion medium, and a soluble electrolyte and having a substantially uniform temperature throughout said layer. (c) applying an electric field extending between the cathode and anode of selected ones of said matrix elements substantially parallel to the flat active surfaces of said cathode and anode to continuously energize the electrodes of one set; and at the same time energize selected electrode sections of the other set to cause selective coagulation and deposition of the colloid on the anode active surface of the selected matrix element. Electrocoagulation of coagulable colloids by electrolysis, characterized by the steps of forming a series of corresponding points representing the desired image, and (d) removing remaining uncoagulated colloids. image reconstruction method. 2. The method of claim 1, wherein step (c) is carried out by successively energizing said anode portion and simultaneously energizing selected ones of said cathode portions. 3. Claim 1, wherein simultaneous selective energy injection into other sets of electrode parts is carried out by sweeping said electrode parts and transmitting electrical pulses to selected ones during sweeping.
The method described in section. 4. Claims 1 and 2, wherein said electrical pulses are varied in voltage or time from one electrode section to another, thereby correspondingly varying the amount of coagulated colloid deposited on the anode active surface of said selected matrix element. The method described in Scope No. 3. 5. The method of claim 1 further comprising the step of coloring the solidified colloid and transferring the colored solidified colloid onto an end-use support. 6. The method of claim 1 further comprising the step of hardening the solidified colloid and using the colloid for offset lithographic printing. 7. Claim 1, wherein the colloid is a linear colloid having a molecular weight of about 10,000 to about 1,000,000.
The method described in section. 8. The method of claim 7, wherein said colloid has a molecular weight of about 100,000 to about 500,000. 9. The method of claim 7, wherein said colloid is selected from the group consisting of animal and vegetable proteins and synthetic copolymers. 10 The colloid is a synthetic copolymer selected from the group consisting of polyacrylic acid, polyacrylamide, polyvinyl alcohol and derivatives thereof, the dispersing medium is water, and the electrolyte is potassium chloride, sodium chloride, chloride, etc. 8. The method of claim 7, wherein the compound is selected from the group consisting of calcium, nickel chloride, lithium chloride, ammonium chloride, copper chloride and magnesium sulfate. 11 A number of electrolytically inert cathodes and anodes electrically insulated from one another and arranged in a matrix of dot-forming elements, each of which is electrically insulated from one another and arranged in parallel. A first set and a second set of insulated strip electrode parts.
the first set of cathode sections extending laterally of the second set of anode sections and having a plurality of protruding conductive sections spaced apart along their lengths, each having a flat active end surface. The protrusions of each of the cathode sections pass through corresponding holes in the anode section, and the flat active end surfaces of each of the protrusions and the flat active surface portions of each of the anode sections adjacent to the holes are connected to each other through corresponding holes in the anode section. Extending substantially in a common plane to form the matrix elements, the electrode active surface includes thereon an electrolytically solidified colloid, a liquid dispersive medium and a soluble electrolyte, substantially dispersing the entire layer. suitable for receiving a layer of a substantially colloidal dispersion having a uniform temperature; and applying electrical energy to the cathodes and anodes of selected ones of said matrix elements on the anode active surfaces of said selected matrix elements. means for causing selective coagulation and deposition of said colloid to form a series of corresponding points representing the desired image, the selection of a member for successively energizing one set of electrodes and the other set of electrodes; An image reproducing device using electrocoagulation of a colloid that can be coagulated by electrolysis, characterized in that: an electric energy application means including a member that simultaneously applies energy to a colloid that is coagulated by electrolysis. 12 The means for continuously energizing comprises a sweeping device suitable for sweeping the anode connected to the positive terminal of a DC power source, and the means for selectively energizing further comprises a sweeping device suitable for sweeping the anode connected to the positive terminal of a DC power source. Claim 11 comprising a sweeping device connected to the negative terminal of said power supply and a computing device coupled to said sweeping device for transmitting electrical pulses to selected ones of said cathode sections during operation of said coupling device. The equipment described in section. 13. Further comprising modulating means for varying said electrical pulses in voltage or time from one cathode section to another to correspondingly vary the amount of coagulated colloid deposited on the anode active surface of said selected matrix element. The device according to item 12. 14. The device of claim 11, wherein said matrix element comprises a single said protrusion substantially at its center. 15. Claim 11, wherein said matrix element comprises said plurality of projections spaced to form an image with uniform tone distribution.
The equipment described in section. 16 The above matrix element is approximately 125μ×
15. The device of claim 14, having a square surface area of 125 microns and wherein said single protrusion is circular in cross-section and has a diameter of about 26 to 50 microns. 17. The apparatus of claim 11, wherein each said protrusion is electrically insulated from its adjacent anode section by a layer of insulating material about 5 to 10 microns thick. 18. The device of claim 11, wherein said anode portions are electrically insulated from each other by a layer of insulating material having a thickness of about 10 to 25 microns. 19. The device of claim 18, wherein said layer of insulating material has a thickness of about 10 microns. 20 The above matrix is approximately
12. Apparatus according to claim 11, comprising 40,000 dot-forming matrix elements.