Imaging material regenerating apparatus and liquid processing method

Abstract

 A wet-type regenerating device for applying a liquid to a substrate supporting a printing material thereon and, thereby, removing the printing material from the substance includes a reservoir for receiving the liquid, and means for exposing the liquid to a circumstance that prevents the liquid from rotting and molding. The exposing means may use any one of ozone, ultraviolet ray, and heat and a combination thereof.

Description

TITLE OF THE INVENTION

[0001] The present invention relates to a wet-type regenerating apparatus for a regeneration of a recording medium or supporting member that supports a printing material, in which the recording medium is applied with a certain liquid to thereby remove the printing material therefrom. In particular, the present invention relates to a wet-type regenerating apparatus in which the supporting member such as plain paper for copy and printing machines and plastic transparent sheet for an overhead projector, bearing the printing material such as toner or ink, is brought into contact with the liquid to remove the printing material therefrom. Further, the present invention relates to a method for treating the liquid used in the wet-type regenerating apparatus, i.e., method for processing the liquid and method for decolorizing colorant contained in the liquid.

BACKGROUND OF THE INVENTION

[0002] In order to reuse natural resources, unexamined Japanese Patent Publications 6-222604, 7-311523 and 7-13383 disclose a regenerating apparatus in which a copied or princed sheet supporting a printing material such as toner that forms a visual image is regenerated by removing the printing material therefrom. The wet-type regenerating apparatus disclosed in the publications employs a certain process for removing the printing material from the sheet, in which process the copied and printed sheet as well as the printing material is brought into contact with a water-based liquid and thereby swelled so that the printing material can be separated from the sheet.

[0003] Disadvantageously, the water-based liquid is unable to prevent the propagation of bacteria by itself. This means that the liquid that has been reserved for a long period in a reservoir provided in the regenerating device may permit the propagation of bacteria, causing an occurrence of unpleasant odors in a couple of weeks.

[0004] To prevent this, another unexamined Japanese Patent Publication 7-104620 discloses a technique in which a certain preservative is added in the water-based liquid. In this arrangement, the added preservative is carried away with the sheet transported in and through the liquid, so that the preservative remained in the liquid decreases and thereby the preservative effect thereof will be deteriorated with the increase of the number of sheet regenerated. To prevent this, the preservative should be supplemented periodicly, which requires a great deal of effort for controlling the device as well as the preservative.

SUMMARY OF THE INVENTION

[0005] Therefore, an object of the present invention is to provide a wet-type regenerating apparatus that includes means for provide a positive preservative and antimold effect for a long period. Another object of the present invention is to provide a wet-type regenerating apparatus that does not require any complicated process such as the supplement of the preservative and antimold agent.

[0006] Accordingly, a wet-type regenerating device for applying a liquid to a substrate supporting a printing material thereon and, thereby, removing the printing material from the substance includes a reservoir for receiving the liquid, and means for exposing the liquid to a circumstance that prevents the liquid from rotting and molding. The exposing means may use any one of ozone, ultraviolet ray, and heat and a combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] 

Fig. 1 is a cross-sectional view of a wet-type regenerating device according to the first embodiment of the present invention;

Fig. 2 is a cross-sectional view of the wet-type regenerating device according to the second embodiment of the present invention; and

Fig. 3 is a cross-sectional view of the wet-type regenerating device according to the third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

I. FIRST EMBODIMENT

[0008] Fig. 1 shows a wet-type regenerating device, generally indicated by reference numeral 1, according to the present invention. The device 1 is used for removing a printing material such as toner from a tailor-made, copied or printed sheet and thereby regenerating the material into a condition in which it can be reused for further copying and printing.

[0009] The tailor-made sheet has a three-layered structure of base, intermediate, and top layers or a five-layered structure in which the base layer supports intermediate and then top layers on its opposite sides. Preferably, the base layer is made of plastic film or paper. Also, the intermediate adhesive layer is used to bond the base and top layers and may be made of resin such as urethan, acrylic, and styrene. Further, the top layer may be made of water-swellable resin, preberably obtained by cross-linking the water-based resin. Note that the "water-swellable" means absorbing water or water-based solvent and thereby to swell but not being dissolved therein. Components of the sheet and each of the layers of the sheet is described in detail in the unexamined Japanese Patent Publication 11-218955, which is incorporated herein by reference.

[0010] Referring to Fig. 1, descriptions will be made to the regenerating device 1 in detail below. The regenerating device 1 has a housing 2 or casing that defines an appearance thereof. In the drawing, the housing 2 has a supply station 3 on its left wall for receiving a stack of sheets 4 and supplying each of the sheets for regeneration thereof. Similar to the typical sheet supply station provided for the copying and printing machines, the supply station 3 has a tray 5 or cassette for supporting the stack of sheets and a supply mechanism 6 for transporting the uppermost sheet 4 to a first sheet transporting mechanism. Typically, the supply mechanism 6 has a supply roller 7 capable of making a frictional contact with a top surface of the uppermost sheet 4 and a motor (not shown) for driving the supply roller 7.

[0011] The first sheet transporting mechanism 8, which is extended from the supply station 3 to a dipping station which will be described below, has a sheet guide 9 for guiding the sheet 4 during the transport of the sheet 4. Preferably, where a distance from the supply to dip stations is far long and no transporting member such as transport roller, other than the transporting mechanism 8, is mounted therebetween for providing the sheet with any transporting force, the transporting mechanism is preferably provided with one or more transporting rollers, for example. This is equally applied to the second and third sheet transporting mechanisms described below.

[0012] As shown in Fig. 1, a pre-drying station 10 is preferably provided in the mid portion of the first sheet transporting mechanism 8. The pre-drying station 10 is used for the pre-heating of the sheet, in particular top and bottom surface portions thereof to some extent so that, upon making a contact with water, the dried sheet car. absorb water to swell instantly. In this embodiment, the pre-drying station 10 has a pair of rollers 11 and 12 provided on opposite, i.e., upper and lower, sides of the sheet 4 to be transported along the sheet guide 9. In this embodiment, the upper roller 11 of the pair of rollers has a heat source or heater 13 provided therein. Preferably, in order to reduce a time necessary for pre-drying of the sheet, in particular the five-layered sheet, the lower roller 12 may also include the heater therein to heat and dry the opposite surface portions of the sheet 4. The rollers 11 and 12, either of which being drivingly connected with a motor not shown, are supported in a parallel fashion, so that they make an elongated, peripheral contact with each other.

[0013] It should be noted that the pre-drying station 10 is not limited to the pair of rollers 11 and 12 and may be another structure or device such as heater with heated-air, dehumidifying device, and vacuum heating device, provided that it can dehydrate the sheet.

[0014] The dip station 14 includes a reservoir 15 with a predetermined shape and size to accommodate a certain amount of liauid 16. Typically, the liquid 16 is made of water and detergent that improves a permeability of the water into the surface portions of the sheet 4. It should be noted that the detergent is not necessarily contained and the liquid may include only water. Also, another material may be added to the liquid as required.

[0015] The second sheet transport mechanism 17 is provided in the reservoir 15 so that the sheet fed from the upstream side of the reservoir 15 with respect to the sheet transporting direction (from left to right in the drawing) toward the downstream side thereof is transported in and through the liquid 16. The second sheet transport mechanism 17 has a first pair of rollers 18 mounted on the upstream side of the reservoir 15, a second pair of rollers 19 mounted on the downstream side of the reservoir 15, and a second sheet guide 20 mounted between the first and second pairs of rollers 18 and 19. As shown in the drawing, according to the embodiment, each of the first and second pair of rollers, 18 and 19, is constructed by two, upper and lower rollers and any one of which rollers is drivingly connected with a motor not shown. Also, the upper and lower rollers are arranged in a parallel fashion so that they define a peripheral biasing contact with each other in the liquid 16. Further, the second sheet guide 20, which is mounted between the contact portions of first and second pairs of rollers, 18 and 19, so that it guides the sheet 4 fed from the peripheral contact region of the first pair of rollers 18 toward another peripheral contact region of the second pair of rollers 19.

[0016] Although the dip station 14 includes one reservoir 15, another reservoir for the supplement of the liquid may be provided to maintain a certain amount of liquid in the reservoir 15. In this instance, the reservoir may be fluidly connected with the supplemental reservoir through a suitable liquid feed tube.

[0017] Also, in order to collect foreign matters in the liquid 16, for example, printing material separated from the sheets, a collecting station may be provided in the device. For example, the collecting station may be made of a closed circuit having a filter for collecting foreign matters, a tube fluidly connecting between the filter and the reservoir 15, and a pump mounted in the tube, so that the liquid is circulated in the tube while the foreign matters are collected by the filter.

[0018] Further, in order to attain a smooth supply of sheet 4 into the contact region of the first pair of rollers 18, one end positioned on the downstream side of the first sheet guide 9 in the first sheet transport mechanism 8 described above extends into the reservoir 15 and then terminates at the upstream side of and the vicinity of the contact region of the second pair of rollers 19.

[0019] Furthermore, in order to attain a smooth draw-up operation of the sheet 4 from the liquid 16 that has just passed the contact region of the second pair of rollers 19, one end positioned on the upstream side of the sheet guide in the third sheet transporting mechanism extends in the reservoir and terminates at the vicinity of the downstream side of the contact region of the second pair of rollers 19.

[0020] The dip station 14 has a liquid purifier 21 that prevents the liquid 16 from rotting. The liquid purifier 21 has a suction pump 22 for drawing air. The pump 22 is connected at its output to one end of an air supply tube 23. The other end of the air supply tube 23 is connected to a discharge section 24 mounted in the liquid 16 received in the reservoir 15. The discharge section 24 is used to change air from the pump 22 into small bubbles and then supply the bubbles into the liquid 16. For this purpose, the discharge section 24 is made of, for example, air-stone that has a number of small 1 vents. The supply tube 23 includes an ozone generator 25 so that air with ozone generated by the ozone generator 25 is discharged from the discharge section 24 into the liquid 16.

[0021] The third sheet transport mechanism 26, which is positioned on the opposite side of the reservoir 15 and away from the first sheet transport mechanism 8, has a third sheet guide 27 extending from the downstream side of the reservoir 15 to the vicinity of the right wall of the housing 2. As described above, the upstream end of the sheet guide 27 is extended into the liquid 16 in the reservoir and to the vicinity of the second pair of rollers 19.

[0022] To remove the toner from the sheet 4 dipped in the liquid 16, the third sheet transport mechanism 26 has a cleaner 28. In this embodiment, the cleaner 28 is made of a pair of brush rolls 29 and 30 mounted on the upper and lower sides of the sheet path defined by and along the sheet guide 27. Preferably, each of the brush rolls 29 and 30 has a shaft drivingly connected with a motor not shown and a number of brushes planted in the peripheral surface of the shaft. The brush rolls 29 and 30 are positioned on the opposite sides of the sheet path so that the planted brushes thereof make contacts with opposing upper and lower surfaces of the sheet 4 being transported along the sheet guide 27.

[0023] To rinse off the residual matters remaining on the sheet 4 that has passed through the cleaning station 28, a rinse station 31 is provided on the downstream side of the cleaning station 28 with respect to the sheet transporting direction. The rinse station 31 has a reservoir or tank 32 for receiving a rinsing liquid 33. Preferably, the tank 32 is positioned above the sheet guide 27. The tank 32 is connected at its bottom with one end of a supply tube 34. The other end of the supply tube 34 is positioned at a spray position 35 provided above a portion of the sheet guide 27, on the downstream side of the cleaning station 28 so that the rinsing liquid 33 is sprayed at the spray position 35 onto the sheet 4 that has passed the cleaning station 28. Preferably, a control valve not shown is provided in the supply tube for controlling an amount of rinsing liquid 33 to be sprayed.

[0024] Preferably, the rinsing liquid 33 is the liquid 16 received in the reservoir 15. In this instance, return means may be provided for collecting the sprayed liquid 33 and then returning the same to the reservoir. For example, the return means may be a plate positioned downwardly toward the reservoir 15. Also, means for keeping a level of the liquid in the reservoir constant may be provided. This means may include a tube fluidly connecting between the tank 32 and the reservoir 15, a pump for pumping the liquid 16 (and rinsing liquid) from the reservoir 15 to the tank 32 and/or from the tank 32 to the reservoir 15, and a detector for detecting the liquid level in the reservoir 15.

[0025] Although the tank 32 for receiving the rinsing liquid is mounted above the sheet guide 27 and thereby the rinsing liquid 33 is flown by gravity, the tank 32 may be positioned below the sheet guide 27. In this instance, a pump is required for pumping up the liquid.

[0026] Also, although the rinsing liquid is sprayed only onto the upper surface of the sheet, it may be sprayed both upper and lower surfaces of the sheet.

[0027] To remove the liquid 16 from the sheet 4 that has been sprayed with rinsing liquid 33 by the rinsing station 31, a liquid removing station 36 is provided on the downstream side of the spray position 35. In this embodiment, the liquid removing station 36 employs a squeezing technique for nipping the sheet from its upper and lower surfaces and then pressing the liquid away from the sheet. To this end, the liquid removing station 36 includes a pair of squeezing rollers 37 supported in a parallel fashion with their peripheral surfaces biased into contact with each other. In order to squeeze out the liquid from the sheet as much as possible, a biasing force between the squeeze rollers should be designed to be greater than that applied to the pair of sheet transporting rollers. Also, the return means may be extended out below the liquid removing station 36 to collect the liquid 16 squeezed out of the sheet 4.

[0028] In order to dry the sheet into a condition in which the squeezed sheet can be reused in the copying machine for example, a post-drying station 38 is provided on the downstream side of the liquid removing station 36. A dryer used in the post-drying station 38 may be a fan without heater capable applying ambient air to the sheet, a fan with heater capable of applying heated air to the sheet or a roller type heater similar to that used in the pre-drying station.

[0029] A discharge station 39 has a receiving tray 40 mounted on the right wall of the housing 2 for receiving the sheet 4 that has passed the post-drying station 38.

[0030] In operation of the regenerating device 1, the sheets 4 to be regenerated are stacked one on top the other on the tray 5 of the supply station 3. The stacked sheets 4 are fed from the uppermost that is in contact with the supply roller onto the sheet guide 9 of the first sheet transporting mechanism 8 and then into the pre-drying station 10. By the pre-drying station 10, the sheet 4 is heated, so that the absorptive power of the surfaces in the sheet 4 is enhanced. The heated sheet 4 is then fed into the reservoir 15 of the dipping station 14 where it is dipped in the liquid 16. The dipped sheet 4 in liquid 16 is then delivered to the second sheet transporting mechanism and then supplied by the first pair of rollers 18 onto the second sheet guide 20. If necessary, the sheet 4 stays on the second sheet guide 20 until an entire surface portion of the sheet would absorb the liquid. It should be noted that the above-described sheet 4 with three layered or five layered structure, when it is dipped in the liquid 16, gets swollen as it absorbs the liquid in at least base layer. As a result, the adhesive force between the toner and the surface layer supporting the toner is eliminated therefrom, so that the toner can be removed from the surface with a slight mechanical force applied thereto.

[0031] The sheet 4 that has absorbed a sufficient fluid 16 is then transported on the third sheet guide 27 of the third sheet transporting mechanism 26 by the second pair of rollers 19 of the second sheet transporting mechanism 17. Then, the sheet 4 brings at its upper and lower surfaces into contact with the brushes of the rotating brush rolls 29 and 30. This results in that the printing material or toner remaining on the upper and/or lower surfaces of the sheet is scraped off therefrom. Then the sheet 4 is sprayed with the rinsing liquid 33 at the spray position 35 in the rinsing station 31 to remove the residual material on the upper and lower surfaces thereof. Further, the sheet 4 is squeezed to remove the liquid therefrom, then heated at the post-drying station 38, and finally discharged onto the discharge tray 40 of the discharge station 39.

[0032] The liquid 16 received in the reservoir 15 of the dipping station 14 is subject to the preservative and antimold treatment from the liquid purifier 21. Specifically, the ozone generator 25 generates ozone. The ozone together with air is then supplied by the suction pump 22 through the supply tube 23 to the discharge station 24 through which it is discharged into the liquid 16 in the form of bubbles, which sterilizes the liquid to prevent the same from rotting and molding.

[0033] The ensures that the liquid can be maintained for a long period in the reservoir 15 without any generation of the rot or mold. Also, the liquid purifier 21 can be maintained only with a periodic services of the suction pump 22 and the ozone generator 25 but without any supplement of the preservative or antimold agent, which minimizes the maintenance work.

II. SECOND EMBODIMENT

[0034] Fig. 2 shows another regenerating device 1A according to the second embodiment of the present invention. The regenerating device 1A is similar to that disclosed above except for the liquid purifier. Therefore, only the liquid purifier of the second embodiment will be described herfeinafter.

[0035] In the second embodiment, the liquid purifier 21A has a circulation passage 41 or tube. The circulation passage 41, which is opened at its opposite ends in the liquid 16 received in the reservoir 15, includes a circulation pump 42 for the circulation of the liquid 16 along the circulation passage 41, and an irradiator or generator 43 for generating and then irradiating an ultraviolet ray to the liquid 16 being circulated in the circulation passage 41.

[0036] With the regenerator 1A so constructed, the liquid 16 is circulated along the circulation passage 41 by the circulation pump 42. During the circulation, the fluid 16 is exposed to the ultraviolet ray irradiated from the generator 43, which sterilizes the liquid to prevent the same from rotting and molding.

[0037] The ensures that the liquid can be maintained for a long period in the reservoir 15 without any generation of the rot or mold. Also, the liquid purifier 21A can be maintained only with a periodic services of the suction pump 42 and the generator 43, which minimizes the maintenance work.

III. THIRD EMBODIMENT

[0038] Fig. 3 shows another regenerating device according to the third embodiment of the present invention. The regenerator 1B of this embodiment is slightly different in structure and function from that disclosed in the second embodiment. Specifically, the liquid purifier 21B of the regenerating device 1B has a heater 46 in place of the ultraviolet ray generator.

[0039] With the regenerator 13 so constructed, the liquid 16 is circulated along the circulation passage 44 by the circulation pump 45. The circulated liquid 16 is exposed to heat provided from the heater 46. This sterilizes the liquid 16 to prevent its rotting. Also, a sterilizing power depends upon the heat temperature and, in order to attain a suitable effect of rotting and molding, the liquid 16 is preferably heated more than 60 degrees centigrade.

[0040] The ensures that the liquid can be maintained for a long period in the reservoir 15 without any generation of the rot or mold. Also, the liquid purifier 21A can be maintained only with a periodic services of the suction pump 45 and the heater 46, which minimizes the maintenance work.

VI. FOURTH EMBODIMENT

[0041] As described above, preferably the sheet with a three-layered or five-layered structure is used for the regenerating devices according the first to third embodiments. Also, the regenerating devices are designed to remove but not to dissolve the printing material supported on the surfaces of the sheet. However, the present invention is also applicable to another type of regenerating device for regenerating the sheets printed by an image forming device, e.g., ink-jet printer, by which ink is projected and then held in between paper fibers. In this instance, once the sheet is dipped in the fluid, the ink in the sheet is dissolved into the fluid. Also, dyes in the ink dissolved in the fluid are decolorized by the exposure of the ultraviolet ray. Further, although generally the fluid 16 in the reservoir 15 would become cloudy with the increase of the number of regenerated sheets, the dyes of the dissolved ink in the fluid 16 are decolorized by the exposure of the ozone and/or ultraviolet ray, which maintains the clearness of the fluid.

V. TESTS AND EVALUATION

[0042] Tests were conducted to evaluate a durability of the fluid by the use of the regenerating devices of the first to third embodiments and another regenerating devices for comparison. Conditions of the test are described below. In the tests, a contamination, smell, and turbidity (absorptivity) of the fluid is evaluated for each of the tested devices.

Test 1

(i) Sheet

[0043] The three-layered sheet was used. The base layer of the sheet was a paper commercially available from Minolta, under the tradename of "CF paper".

[0044] A solution for the intermediate layer was made by preparing 100g of water-based urethane resin (available from Asahidennka under the tradename of "HUX-232"), adding 5g of melamine-fontmaldehyde resin (available from Sumitomo Chemical under the tradename of "Sumirase") and 0.1g of polyoxiethylenenonylphenylether, and then agitating the mixture thereof for five minutes. The solution was applied onto the opposite surfaces of the base layer by the use of a coating bar. After application, the base layer with the solution was dried for five minutes at 120 degrees centigrade and then subject to corona discharge treatment to form the intermediate layer having a thickness of 5µm.

[0045] A solution for the top surface was prepared by dissolving 16g of water-based resin, i.e., anion-denaturated polyvynilalcohol (available from Kurare under the tradename of "KL-318") into 184g of water. The solution was mixed with 3.2g of epoxy cross-linker (available from Nagasekasei under the tradename of "Deconal EX-313") and 0.4g of polyoxiethylenenonylphenylether and then agitated for 15 minutes. The prepared solution was coated on the intermediate layers by the use of the coating bar and then heated at 120 degrees centigrade for two hours to form the top layer having a thickness of 9µm.

(ii) Printing condition (Printer)

[0046] Used was a laser printer commercially available from Epson under the tradename of LP-9200 which uses a powder toner. A black/white ratio of the printed image was 5%. The image was printed on the A4-sized sheet.

(iii) Regenerating device

a. Sheet transport

[0047] The A4-sized sheet was transported with its longitudinal edges directed along the transporting direction.

b. Pre-dry

[0048] The surface temperature of the heat roller was set to be 60 degrees centigrade. The sheet was transported at 5mm per second.

c. Dip

[0049] The liquid, the amount being 20 litters, was prepared by mixing 0.1% of detergent (available from Sanyokaseikogyo under the tradename of "Nonypol 60") and 99.9% of water. The liquid was kept 35 degrees centigrade in the reservoir. The dipping time was set to be three minutes.

d. Toner removing

[0050] The brush rolls with nylon brushes were used.

e. Rinse

[0051] Water was used for the rinsing liquid.

f. Purifier

[0052] Ozone generator available from Gomi-shoji under the tradename of "OZ-505", and air-stone made of ceramic stone available from Torio Corporation were used. A duration for generating ozone was set to be eight hours per day.

g. Troughput

[0053] The througput of the device was 100 sheets per day.

h. Evalation

Number of bacteria

[0054] The fluid (sample) was collected after 30 days from the start of the test and then diluted with water up to the dilution rate of 100. A membrane filter of a water sampler (commercially available from Nihon Milipoa under the tradename of "MHPC10025") was dipped in the diluted fluid for 30 seconds. After removing water from the surface thereof, the membrane filter was maintained in the pyrostat at 35 degrees centigrade for 48 hours. Then, the number of colony of bacteria cultivated on the surface of the membrane filter was counted.

Smell

[0055] The fluid (sample) was collected after 30 days from the start of the test. A sensory test was made for the smell of the collected sample. The same test was also made to a sample collected from the fluid of another regenerating device in which no preservative or antimolding agent was added for comparison (Comparative example 1). Turbidity (Absorptivity)

[0056] The fluid (sample) was collected after 30 days from the start of the test. The sample was exposed to light of 370nm and then the absorptivity of the sample was measured. The measurement was made by the use of a spectrophotometer available from Hitachi under the tradename of "U-3210".

Test 2

[0057] Conditions of test 2 were identical to those of test 1 except that the ultraviolet-ray generator was employed in place of ozone generator. The ultraviolet-ray generator used in the test 2 was available from Nisso under the tradename of "NUV-9000" with 9W lamp-output. The amount of liquid exposed to ultraviolet ray was seven liters per minute. The irradiation time of the ultraviolet ray was eight hours per day.

Test 3

[0058] Conditions of test 3 were identical to those of test 1 except that the heater was employed in place of ozone generator. The heater used in test 3 was a resistance heater with the electricity consumption of 150W. The amount of fluid heated was 30ml per minute and the duration for heating was eight hours per day.

Test 4

[0059] Conditions of test 4 were identical to those of test 1 except in that an ink-jet printer commercially available from Hewlett Packard under the tradename of "DeskJet 710C" was used for printing. The printed image, black/white ratio being 5%, was a full color image formed by the use of yellow, magenta, cyan, and black inks. The throughput of the regenerating device was 10 sheets per day.

Test 5

[0060] Conditions of test 5 were identical to those of test 2 except for the followings. The ink-jet printer commercially available from Hewlett Packard under the tradename of 'DeskJet 710C" was used for printing. The printed image, black/white ratio being 5%, was a full color image formed by the use of yellow, magenta, cyan, and black inks. The throughput of the regenerating device was 10 sheets per day.

Test 6 (Comparative test 1)

[0061] Conditions of comparative test 1 were identical to those of test 1 except that no ozone generator was employed therefor.

Test 7 (Comparative test 2)

[0062] Conditions of comparative test 1 were identical to those of test 1 except that no ozone generator was employed therefor.

Test results

[0063] The test results are shown in the following table.

No. of Test	Number of colonies	Smell	Absorptivity
1	Less than 100	No	0.18
2	Less than 100	No	0.08
3	500	No	0.25
4	Less than 100	No	0.08
5	Less than 100	No	0.20
6	More than 1000	Yes	0.25
7	More than 1000	Yes	More than 1.0

Evaluation

[0064] The table indicates that the ozone and ultraviolet ray are so effective for the prevention of the contamination of the regenerating fluid in the sheet regenerating device.

VI. OTHERS

[0065] The tests made by the inventor has clarified the followings:

1. Temperature control of fluid
   In the regenerating device for removing toner or dissolving ink, the temperature of the liquid is controlled from about 5 to 65 degrees centigrade, preferably about 25 to 45 degrees centigrade, most preferably about 35 degrees centigrade. Also discovered is that the fluid with low temperature decreases the removability of toner and the dissolvablity of ink. On the other hand, the fluid with higher temperature disadvantageously accelerates the evaporation of the fluid. It should be noted that the fluid with the temperature ranges disadvantageously increases the fertility of bacteria and, therefore, the above-described preservative and anitmolding techiques are indispensable to the regenerating devices.

2. Other preservative and antimolding techniques
   For the prevention of both rotting and molding, other techniques are also effective, for example, to maintain the pH of the fluid 4 or less or 9 or more, and to apply an ultrasonic wave and/or an electric excitation.

3. Other application
   Although in the previous embodiments the fluid in the regenerating reservoir is exposed to ozone for example to prevent the rotting and molding, the present invention can be applied equally to an auxiliary agent to be supplied to the fluid, the detergent contained in its reservoir, and the rinsing liquid.

[0066] As described above, according to the regenerating device and method of the present invention, the liquid or liquids in the device can be well reserved without rotting and the dyes in the printing material dissolved in the liauid can be decolorized, which ensures a long time use of the liquid. This in turn means that the liquid can be well controlled without any excessive supplement or exchange thereof.

Claims

1. A wet-type regenerating device for applying a liquid to a substrate supporting a printing material thereon and, thereby, removing the printing material from the substance, comprising:

a reservoir for receiving said liquid; and

means for exposing said liquid to a circumstance that prevents said liquid from rotting and molding.

2. A device in accordance with claim 1, wherein said preventing means includes

a generator for generating ozone; and

means for exposing said liquid to said ozone generated by said generator.

3. A device in accordance with claim 2, wherein said exposing means includes a passage, said passage having one end fluidly connected to said ozone generator and the other end positioned in said fluid, said ozone generated by said ozone generator is transported through said passage and then discharged in said fluid in the form of bubbles.

4. A device in accordance with claim 1, wherein said preventing means includes

a generator for generating ultraviolet ray; and

means for irradiating said ultraviolet ray generated by said generator to said fluid.

5. A device in accordance with claim 4, wherein said irradiating means includes an irradiating station for irradiating said ultraviolet ray to said liquid, and means for circulating said fluid through said irradiating station.

6. A device in accordance with claim 1, wherein said preventing means includes means for heating said fluid.

7. A device in accordance with claim 6, wherein said heating means has a heating station for heating said fluid, and means for circulating said fluid through said heating station.

8. A device in accordance with claim 7, wherein said heating station heats said fluid at 60 degrees centigrade or more.

9. A wet-type regenerating device for applying a fluid to a substrate supporting a printing material thereon and, thereby, removing the printing material from the substance, comprising:

a reservoir for receiving said liquid and said printing material removed from said substrate; and

means for decolorizing said printing material in said reservoir.

10. A device in accordance with claim 9, wherein saic decolorizing means includes

a generator for generating ozone; and

means for exposing said liquid to said ozone generated by said ozone generator.

11. A device in accordance with claim 10, wherein said exposing means includes a passage, said passage having one end fluidly connected to said ozone generator and the other end positioned in said fluid, said ozone generated by said ozone generator is transported through said passage and then discharged in said fluid in the form of bubbles.

12. A device in accordance with claim 9, wherein said decolorizing means includes

a generator for generating ultraviolet ray; and

means for irradiating said ultraviolet ray generated by said generator to said fluid.

13. A device in accordance with claim 12, wherein said irradiating means includes an irradiating station for irradiating said ultraviolet ray to said liquid, and means for circulating said fluid through said irradiating station

14. A method for use with a wet-type regenerating device for applying a fluid to a substrate supporting a printing material thereon and, thereby, removing the printing material from the substance, comprising:
   exposing said fluid to either an ozone or an ultraviolet ray or both.

Drawing