Patent Publication Number: US-3880515-A

Title: Carrier liquid vapor recovering device electrophotographic apparatus

Description:
United States Patent 1 1 Tanaka et al.  
 . 1 51 Apr. 29, 1975 CARRIER LIQUID VAPOR RECOVERING DEVICE ELECTROPHOTOGRAPHIC APPARATUS Inventors: Hiroshi Tanaka: lkuo Soma. both of Tokyo. Japan Assignee: Canon Kabushilti Keisha. Tokyo.  
 Japan Filed: June 1. 1972 Appl. No.: 258.653  
 Foreign Application Priority Data June 3. 1971 Japan 4648948 US. Cl. 355/10: 55/126. 55/135; 55/138; 55/269 Int. Cl (103g 13/10 Field of Search 55/6. 9. 11. 124. 126. 55/135. 136. I37. 138. 269: 355/10. 15  
 References Cited UNITED STATES PATENTS 10/1920 Duffy 55/11 5/1922 Wolcott 55/10 X 10/1926 Schmidt 55/9 X Primary Examiner-Bernard Nozick Attorney. Agent. or Firm-Fitzpatrick. Cclla. Harper &amp; Scinto [57] ABSTRACT This invention provides a carrier liquid vapor recovering device to recover the carrier liquid by 1iqucf ving the carrier vapor produced within the photocopying device. The carrier vapor is cooled to obtain the carrier mist which in turn is collected by the electrodes or corona charger and the drop-like carrier liquid is recovered to use it repeatedly.  
 4 Claims. 3 Drawing Figures 2 5 7 L I 1 x REPRODUCTION PROCESS TREATING PORTION FDEVELOPING onnou *NEHTEQAPR2919Y5 3,880,515  
 &#39; aapnooucnon:  
 PROCESS TREATING PORTION {DEVELOPING l I ponnou CARRIER LIQUID VAPOR RECOVERING DEVICE ELECTROPI&#39;IOTOGRAPI-IIC APPARATUS BACKGROUND OF THE INVENTION l.&#39;Field of the Invention This invention relates to a device which. in a photographic copying device of liquid development type. rccovers by liquefying the carrier liquid vapor generated mainly from the copy sheet that has undergone development.  
 2. Description of the Prior Art In electrophotographic devices. when the photosensitive paper that have undergone liquid development. or the transfer paper. to which has been transferred the toner image, which was developed on the Xerograph plate through liquid development. is fixed by heating. the carrier liquid (commercially known. for example. as Isoper H. G. etc.) that have impregnated into the photosensitive paper or toner powder image is vaporized to become vapor or, by the temperature rise of the inside of the above-mentioned device due to using it for a long period of time the above-mentioned carrier liquid is vaporized directly from the developing device to become vapor. and the vapor thus formed is liable to leak to the outside of the copying equipment. The air containing this vapor is harmful to the operator of the copying equipment and leaves problem in the sanitary management.  
 SUMMARY OF THE INVENTION This invention is to offer a miniaturized device which liquefies and recovers the generated vapor of the carrier liquid within the copying equipment to prevent its leakage to the outside of the equipment and to eliminate the bad influence on human body and which simultaneously reduces the consumption of carrier liquid by collecting the liquefied carrier liquid to the developer supplying device.  
  The first object according to this invention is to cool the carrier liquid to produce mist of the carrier liquid and recover the liquid the liquid by liquefying the mist.  
  The second object according to this invention is to collect the above-mentioned mist by using electrode and to collect the carrier liquid in drop form.  
  The third object according to this invention is to charge electrically the abovementioned mist of the carrier liquid and collect the charged mist by using electrode.  
  The fourth object according to this invention is to return the carrier liquid that have recovered as described above to the developer supplying device and use the liquid again.  
 BRIEF DESCRIPTION FIG. I is a simplified lateral cross section of an embodiment of the invented carrier liquid vapor recovering device in a state in which the cooling compartment section and the Iiquefying compartment section are separately arranged.  
  FIG. 2 is a simplified lateral cross section showing the above-mentioned carrier liquid vapor recovering device in a state where the device is not separated into the cooling compartment section and the liquefying compartment section.  
  FIG. 3 is a simplified lateral cross section of the above-mentioned cooling compartment and the liquefying compartment having a corona charger therebetween.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT A concrete example of this invention will be described hereinafter referring to the drawings.  
  In FIG. I, I is the body of carrier liquid vapor recov ering device composed of a metal having a comparatively good thermoconductivity such as copper. phosphor bronze. aluminum. iron. stainless steel. etc. The body I is provided with a sucking port 2. which leads the carrier liquid vapor. which as indicated at I4 is generated from the drying and fixing section and developing section of the photographic copying equipment not illustrated. into the body. a recovering port 3. which collects the liquefied carrier liquid into the above mentioned developing section I6 and an exhaust port 4, which is near the above-mentioned recovering port 3 to discharge the dry air remaining after removing the carrier liquid from the vapor of the liquid. And on the inner walls of the body I, which is positioning respectively near the above-mentioned sucking port 2 in a manner facing to each other. there are provided a plural number of guide plates 5, which project out from each wall surface toward opposite wall alternately. to form a cooling compartment having a meandering guide path 6, and further. in the lower section of the above-mentioned cooling compartment 7, a liquefying compartment 10 composed by providing a collecting net 9. which concists of metal wires placed in screen like in many stages vertically and which alternately applied with positive and negative voltages from the power source 8 placed in the outside of the abovementioned body I. The abovementioned cooling compartment 7 and the liquefying compartment I0 are conductive with each other and arrangement is made so that the carrier liquid that has been liquefied in the liquefying compartment I0 runs naturally down along the inner wall surface of the said compartment toward the above-mentioned recovering port 3. Members 11 and 11&#39; are the cooling fans which accelerate the heat dissipating effect of the outer wall of the above-mentioned body I by being positioned at the outside of the said body and by blowing the air to the surface of the outer wall. However, in this invention, other cooling means can also be employed.  
  Next, another embodiment of this invention will be described referring to FIG. 2. FIG. 2 shows a construction where the cooling compartment 7 and the liquefying compartment 10 are not separated vertically as shown in FIG. 1, but collecting nets 9 consisting of screen-like metal wires are installed stage by stage over the total height of the body and, in between these collecting nets 9, there are placed the above-mentioned guide plates at proper places so as to form a cooling and liquefying compartment.  
  FIG. 3 shown an embodiment in which a corona charger 13 is interposed between the cooling compartment 7 and the liquefying compartment 10. Taking into consideration the generation of ozone, the most suitable polarity of the charger is positive. The arrow a shows the direction of corona ions.  
  Since the invented carrier liquid vapor recovering device is composed as mentioned above. the carrier liquid vapor generated from the inside of an clectrophotographic equipment is introduced by proper device (not illustrated) into the body 1 made of a metal such as copper. phosphor bronze, aluminum. iron. stainless stell. etc. through the sucking port 2 at the upper section. This carrier liquid vapor that have been introduced in is converted into liquid drops while the vapor is passing through the guide path 6 of the cooling com partment 7.  
  Although the cooling compartment 7 shown in FIG. 1 is the air cooling system consisting of the cooling fan 11 which blow the air to the outer wall of the body 1 while the carrier liquid vapor is sent downward meanderingly through the guide plates which project alternatingly from left and right of the upper half of the body 1. use of a water cooling system consisting of jacket construction can also be considered.  
  Next the carrier liquid vapor that has been made to form mist drops is led to the liquefying compartment formed in the lower half of the body 1. The liquefying compartment [0 consists of the collecting nets 9 formed by spreading metal wires 10 in screen form vertically in several stages which are applied with positive and negative voltages alternately. Therefore. the carrier liquid vapor that have been made to take forms of mist drops at the cooling compartment 7 move along the electric field formed in the liquefying compartment 10. if the vapor has already been charged either positive or negative or when the vapor is charged by the corona charger [2 installed in the body 1 is shown in H0. 3. and is converted to liquid drops along the screen-like collecting nets 9 or along the wall surface of the body 1, and is collected into the developer supplying device not illustrated from the collecting port 3 formed at the lower section of the body I by transferring means such as gravity. pump, etc. The air that have passed the liquefying compartment 10 and have substantially removed of carrier liquid vapor is led to the exhaust port 4 extending upward from the collecting port 3 like a chimney. The polarity of corona charging can be either positive or negative or AC corona. However. from the point of view of preventing the generation of ozone etc.. positive polarity is desirable.  
  Here, the same effect can be obtained by only spreading electrically conductive wires or by installing electrically conductive plates in the liquefying compartment 10 instead of using screen-like metal nets.  
  The cooling fan 11&#39; is used to accelerate the conversion ofcarrier liquid vapor still remaining in the liquefying compartment [0 into mist drops. Examples of application of the above-mentioned carrier liquid vapor recovering device will be described below.  
 Example 1 In the electrophotographic liquid developing device now in use an air containing the carrier liquid vapor in the concentration of about 5 mg/l is generated when the device is run continuously over a long period of time. By applying a voltage of SOOOV to the collecting nets 9 installed in the liquefying compartment N] of the above-mentioned invented device shown in FIG. I, the carrier liquid concentration of the air discharged from the exhaust port 4 was reduced to below 0.5 mg/l. The dimensions of entire equipment shown in FIG. I which was used in this case were about 500 X lOO X 50 (mm).  
  If in practizing the invented device, a means is taken to collect the carrier liquid vapor generated from copied sheet at a high concentration the device can be made further smaller because liquefaction becomes easy even when the flow path of the carrier liquid vapor in the cooling compartment shown in FIG. 7 becomes shorter Furthermore. the device can be connected to the developer storing tank to collect the carrier liquid vaporized from the storing tank.  
 Example 2 Using the device shown in FIG. 3 and the same processing as described in Example ll was carried out after applying a voltage of about BOOOV to the corona charger. Then the carrier vapor content of the air discharged from the exhaust port 4 was below 0.1mg/l.  
 We claim:  
  1. In an electrophotographic copying device of the wet development type having a developing portion and a reproduction station. the improvement comprising a developer collecting device including a housing having an inlet means for receiving developer vapor generated at a reproduction process treating station in said copying device, an outlet for discharging air and a second outlet for discharging liquefied developer, baffle means mounted in said housing to provide a tortuous path for the developer passing through said housing, cooling means in said housing comprising a substance having a good heat conductivity for cooling the developer vapor to convert it into mist, and electric field applying means in said housing for collecting and liquefying said developer mist due to an electrostatic attraction by applying an electric field thereto, and means connected to said second outlet for leading said collected developer to the developing portion of said copying machine for reuse.  
  2. A developer collecting device according to claim 1, wherein said electric-field applying means includes a corona discharger.  
  3. A developer collecting device according to claim 1, wherein said electric-field applying means includes at least a couple of electrode nets applied with a voltage. p  
  4. A developer collecting device according to claim 1, wherein said cooling means and said electric-field applying means are simultaneously operated.