US3720183A

US3720183A - Transfer device for images by the use of liquid development electrophotography

Info

Publication number: US3720183A
Application number: US00102529A
Authority: US
Inventors: S Suzuki
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 1967-11-08
Filing date: 1970-12-29
Publication date: 1973-03-13
Anticipated expiration: 1990-03-13
Also published as: DE1804367B2; GB1253061A; DE1804367A1

Abstract

There is disclosed herein a simple and reliable liquid development transfer device for images by the use of liquid development electrophotography.

Description

United States Patent 1191 Suzuki 1 TRANSFER DEVICE FOR IMAGES BY THE USE OF LIQUID DEVELOPMENT ELECTROPHOTOGRAPHY [75] Inventor: Shigeru Suzuki, Yokohama, Japan [73] Assignee: Kabushiki Kaisha Ricoh, Tokyo,

Japan [22] Filed: Dec. 29, 1970 21 Appl. No.: 102,529

Related U.S. Application Data [62] Division of Ser. No. 771,162, Oct. 28, 1968, abandoned.

[30] Foreign Application Priority Data Nov. 8, 1967 Japan ..42/7l778 52 us. c1 ..l18/637,1l7/37LE,118/258, 11s o1o.23,355/1o 151 1m. c1. ..G03g 13/00 [58] Field of Search ..l l8/DIG. 23, 637, 257, 258,

118/259, 222; 117/175, 37 LE; 96/l.4; 355/10 1111 3,720,183 1 51Marh 13, 1973 [56] References Cited UNITED STATES PATENTS 3,281,241 10/1966 Mihajlov ..96/l 3,120,446 2/1964 Hunter ..1 17/1 7.5 3,372,027 3/1968 Gnndlach et a1. ..96/l 3,596,635 8/1971 Smitzer ..1 18/637 3,202,526 8/1965 Ostensen. ..1 18/637 2,951,443 9/1960 Byrne 1 01/426 3,556,784 1/1971 Robinson et al ..96/1 .4 2,565,370 8/1951 Hodin ..9 l /49 Primary Examiner-Mervin Stein Assistant Examiner-Leo Millstein Attorney-Waters, Roditi, Schwartz & Nissen [57] ABSTRACT There is disclosed herein a simple and reliable liquid development transfer device for images by the use of liquid development electrophotography.

- 5 Claims, 3 Drawing Figures TRANSFER DEVICE FOR IMAGES BY THE USE OF LIQUID DEVELOPMENT ELECTROPHOTOGRAPIIY This application is a divisional application based on my earlier filed application Ser. No. 771,162 filed Oct. 28, 1968, formerly copending but now abandoned.

The present invention relates to transfer devices for images by the use of liquid development electrophotography.

Since the copy paper on which an image is to be made by liquid development electrophotography is generally opaque, it cannot be used as an original for a copying apparatus such as a diazo-type copying apparatus, in which transparency of the original paper is required. 7

A liquid development electrophotographic copy paper for an or a second original has already been used in practice. However, since the use of ZnO in the paper cannot be avoided and this paper absorbs ultraviolet rays the copy speed is slow and the sharpness of the image is not sufficient for practical use.

It is an object of the invention to get rid the abovementioned defects.

It is another object of the invention to provide a simple and reliable device to transfer an image by means of liquid development electrophotography.

With these and other objects in view, the invention will be next explained in connection with the accompanying drawings, wherein:

FIG. 1 is a diagrammatic elevation view of apparatus to show the principle of transfer according to the present invention;

FIG. 2 is a longitudinal cross sectional view through a transfer device according to one embodiment of the present invention; and

FIG. 3 is a fragmentary plan view of feed tables for paper to be transferred and transfer paper.

In FIG. 1, is a paper 1 to be transferred, for example, an image 2 formed by a positive toner which is to be copied by liquid development electrophotography. Copy paper 3 is made of transparent paper such as tracing paper and others the like. The paper (recording material) to be transferred (i.e., having an image to be transferred) and the copy paper (image receiving material) 3 are fed in convergently so as to provide an intimately close gap between them, and a wetting liquid .4 with an appropriate volatility is introduced into the gap between the papers. The toner'on the transfer paper 3 is wetted and softened and then swells. The transfer paper 3 is shifted to a gap between corona discharge electrodes and subjected to a corona discharge from the side of the transfer paper, the toner is transferred to the transfer paper and thereby the image is transferred. The corona discharge is formed between a grounded conductive ro'ller acting as an electrode and an opposed electrode positioned at a .predetermined distance above the roller.

In the following, the structure and the operation of the main parts of a transfer device according to the invention will be explained referring to FIG. 2. When a mainswitch 5 is turned on, a main motor 6 starts to rotate, and guide rollers 10 and 11 rotate in the direction shown by the arrowsbeing driven by sprocket wheels 7 and 8 and a chain 9. A pulley 14 is also rotated by a pulley 12 which is integral-with and coaxially fixed to the sprocket wheel 8 and acts through a round belt 13.

On the front side of the pulley 14 in FlG. 2, a cam 15 is supported coaxially and both are connected through a one revolution clutch. When a start button 16 is pushed, a lever 17, a paper stopper 18, a lever 19 and a lever 20 rotate clockwise around a shaft 21 and undergo displacement from the position depicted shown in broken lines to that by solid lines. These rotating members have a tendency to rotate counterclockwise through the action of a spring 24 which is stretched between a pin 22 at the end of the lever 17 and another pin 23 mounted on a fixed part of the machine.

There is provided a cam follower 25 adjacent the lever 17. When the cam follower 25 falls into a recess 26 of the cam 15, the cam 15 stops rotating. However, the cam 15 rotates when the cam follower 25 is out of the recess 26 and slides around the external periphery of the cam 15.

When the lever 19 is at the position shown in broken lines, it pushes up both ends of the shaft 28 of an upper feed roller 27 so that the upper feed roller 27 is at the position shown in broken lines. Under these conditions, there is a wide gap between the guide roller 11 and the upper feed roller 27. When the paper stopper 17 is at the position shown by the broken lines, the tips of the paper to be transferred on a feed table 29 and of the transfer paper on a feed table 30 strike the stopper 18, and the positioning of both papers with each other is effective. When the lever 20 comes to the position shown by solid lines, the'button of a switch 31 for a corona discharger 32 is pushed, and the circuit for the corona discharger 32 is closed.

When the main switch 5 is turned on, a pumping motor 33 starts to rotate. A wetting liquid 38 is poured into a tank 37 through an opening 36 of a pipe 35 by means of a pump 34. If the paper to be transferred and the transfer paper are placed on the feed tables 29 and 30, respectively, the wetting liquid is fed between the paper to be transferred and the transfer paper, and the toner which forms the image on the paper to be transferred is wetted, softened and swells to some extent.

When the start button 16 is pushed, each rotating member shifts to the position shown in solid lines around the shaft 21 as a center as described above cam follower 25 comes out of the recess 26 of the cam 15 and the cam 15 starts to rotate. The cam follower 25 slides on the external periphery of the cam 15 and each rotating member remains in the position shown in solid lines. When the paper stopper 18 rotates and shifts to the position shown in solid lines, it becomes possible to feed in the paper to be transferred and the transfer paper as the lever 19 rotates to the position shown by a solid line, the upper feed roller 27 comes down and displaces the paper to be transferred and the transfer paper keeping them between the upper feed roller 27 and the guide roller 11 as shown in FIG. 1.

The paper to be transferred and the transfer paper receive a corona discharge while on their way, and pass between

guide rollers

10 and 39. The image is then transferred as explained with above reference to FIG. 1. Though not shown, the paper carrying the image to be transferred and the transfer paper are separated by a separating means, and if necessary, they are heated to be dried. Element 40 is a grounded roller for the corona discharge, and element 41 is a high-voltage power supply for the corona discharge.

When the cam makes one rotation, the cam follower 25 of the lever 17 falls into the recess 26 of its cam 15, and each rotating member comes back to the original position following the stopping of the cam 15.

An indication lamp 42 is lighted when the main switch is turned on.

The feed tables 29 and 30, upon which the paper 'to be transferred and the transfer paper are to be placed are respectively inclined downwardly and forwardly and their forward ends have comb shapes as shown in FIG. 3. Therefore, it is possible to see through them. At the same time, the wetting liquid flows down without dispersing on the tables more than is needed.

The invention as explained above in detail, has the following remarkable effects:

1. An image formed by a liquid development electrophotographic copy can be transferred upon a highly transparent paper by simple means.

2. Since a wetting liquid is poured into the gap between the paper to be transferred and the transfer paper, only one side of each paper becomes wet while the other side is dry, so that both papers are scarcely damaged, easily dried, and convenient to carry.

3. Since the toner is transferred onto the transfer paper through corona discharge, the transferred image becomes uniform.

4. When a paper to be transferred and a transfer paper corona discharge, they have a tendency to stick to the opposite electrodes, so that when the transfer is conducted while the transfer paper is moving on. It is necessary to eliminate this tendency to stick to the opposite electrodes, and for that purpose, the metal roller is used in the invention.

5. Each of the feed tables for a paper to be transferred and a transfer paper has a forward end formed in the comb shape so as to enable easily viewing things underneath through the comb-shaped end, and it also makes the wetting liquid flow downward without dispersing on the tables in an amount more than is needed.

While the present invention has been particularly described in terms of a specific embodiment thereof, it will be understood that numerous deviations and modifications may be readily devised by those skilled in the art without departing from the scope of the invention.

What is claimed is:

1. A device for transferring a toner image from a recording material to an overlaying image receiving material by wetting the toner image and applying a corona discharge electric field, said device comprising separate slide-in channels for the recording material and the image receiving material which are guided into superposed relationship, a plurality of pairs of feed rollers defining a feed path for said materials, corona discharge means for producing a corona discharge normal to the surface of the superposed recording and image receiving materials, said channels including said one pair of said feed rollers being positioned in continuation of two vertically spaced, downwardly inclined and converging supporting plates for the sliding in of the recording and image receiving materials, a wetting agent feed pipe having an o ening arranged between said plates, one roller of sal one part being pivotally mounted, a pivotally mounted lever for pivoting one roller of said one pair to open a roller gap, and an arm attached to said lever for closing the feed path.

2. A device as claimed in claim 1 comprising a motor for driving at least some of said rollers, a cam driven by said motor and a cam follower attached to said lever and cooperating with the cam to determine a transfer cycle.

3. A device as claimed in claim 1 comprising a reservoir for said wetting agent and a pump for pumping said agent through said pipe.

4. A device as claimed in claim 1 comprising a switch for controlling said corona discharge means and means attached to said lever for operating said switch.

5. A device as claimed in claim 1 wherein said plates include comb-shaped edges.

Claims

1. A device for transferring a toner image from a recording material to an overlaying image receiving material by wetting the toner image and applying a corona discharge electric field, said device comprising separate slide-in channels for the recording material and the image receiving material which are guided into superposed relationship, a plurality of pairs of feed rollers defining a feed path for said materials, corona discharge means for producing a corona discharge normal to the surface of the superposed recording and image receiving materials, said channels including said one pair of said feed rollers being positioned in continuation of two vertically spaced, downwardly inclined and converging supporting plates for the sliding in of the recording and image receiving materials, a wetting agent feed pipe having an opening arranged between said plates, one roller of said one pair being pivotally mounted, a pivotally mounted lever for pivoting one roller of said one pair to open a roller gap, and an arm attached to said lever for closing the feed path.