JP2009294411A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus for producing a confidential information document such as a pressure-bonding post card quickly responding to demands. <P>SOLUTION: In the image forming apparatus, a transparent sheet S1 is superposed on a recording sheet S with a toner image formed thereon, an image is formed on the transparent sheet to conceal the information recorded on the recording sheet and then the recording sheet S and the transparent sheet S1 are adhered by heat. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a fax machine that can hide print information.

  Conventionally, in order to transmit character information and the like only to a specific individual, generally, a written item such as a character is in a sealed form so that the individual can confirm the information only after opening.

  In recent years, protection of personal information has been strictly asked. For this reason, at various business establishments, for example, personal information such as various personal data, gradebooks, salary statements, etc., is recorded in the print location inside the text description, and the peripheral portion of the print location or text description The entire surface is distributed in the form of envelopes or cards by bonding or crimping.

  Among these, postcard-sized cards are called “crimp postcards” and can be used at the same charge as regular postcards, making it a highly convenient printing (printing) information concealment system for information providers. It is also widely used for direct mail for advertising.

  In order to use such a printing information concealment system for crimping postcards, etc., secret information has conventionally been created by entrusting it to a specialized manufacturer or introducing an expensive crimping postcard or other manufacturing / printing device. .

  In order to create confidential information using a manufacturing / printing apparatus such as a pressure-sensitive postcard, there are a method of applying an adhesive after information printing, a method of applying an adhesive before information printing, and the like. However, in any case, the premise of creating a large amount of confidential information is essential and expensive.

  Further, such outsourcing to a manufacturer is not a preferable method for creating confidential information because there is a potential problem of leakage of personal information.

  By the way, in recent years, along with the development of personal computers and printers, there has been proposed one that can easily create a crimp postcard even in a small unit so that it can be used by small-scale offices and individuals.

  For example, postcard sheets with release paper to which a pressure sensitive adhesive has been applied in advance are sold. In this method, after printing predetermined character information or the like on the printing surface inside the two-fold, the pressure-sensitive adhesive portion is crimped to complete a postcard for postage.

  In addition, for example, a combination of an adhesive film and a postcard sheet is sold. In this method, after printing predetermined character information or the like on the printing surface inside the double fold, the adhesive film is pressure-bonded with the adhesive film sandwiched inside, so that a postcard for posting can be created.

  However, this is unavoidable, and it is inevitable that handling is complicated, and it is better to make several crimping postcards personally, but it is cheap, quick, and responsive to demand in a certain number of sheets. It can not be created with.

  Therefore, a toner-like adhesive composed of microcapsules containing an adhesive is transferred to the surface of the substrate by electrostatic printing and flash-fixed. At the time of adhesion, the microcapsules are destroyed by pressure and the adhesive in the capsule is leached. Technology has been proposed. This makes it possible to easily create a crimped postcard. This proposal also suggests a pulverized toner obtained by melting, kneading, and pulverizing an adhesive (Patent Document 1).

  Also, put the pressure-bonding substance in the replaceable printing cartridge of the office printer, apply the pressure-bonding substance to government postcards and envelopes in the same way as the printing operation, and then apply it to the pressure-dedicated machine. Proposals have been made for what printers can do. In addition, this proposal suggests that a crimping substance is applied to one side of a fold and one side of a center of a fold. (Patent Document 2).

Japanese Patent Application Laid-Open No. 09-104849 JP 2000-006553 A

  However, both of the techniques of Patent Document 1 and Patent Document 2 are used to create a print information confidential document using a postcard or envelope made by a government company before being applied to a dedicated crimping machine. Therefore, in order to complete it for posting, it must be put on a dedicated crimping machine. In this respect, convenience and responsiveness to demand were lacking.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus for producing an information confidential document such as a postcard for crimping that is responsive to demand.

  Representative means in the present invention for solving the above problems include a first sheet conveying means for conveying a recording sheet, an image forming means for forming a toner image on the sheet, and a sheet on which the toner image is formed. A fixing unit that fixes the image by heating; a retransmission unit that transports the image-formed recording sheet to the image-forming unit again; and a transport unit that transports the image-formed recording sheet to the image-forming unit again. A second sheet conveying unit that conveys the transparent sheet so that the transparent sheet overlaps the image forming surface side of the recording sheet, and after the image is formed on the transparent sheet superimposed on the recording sheet, the image is superimposed by the fixing unit. The recording sheet and the transparent sheet thus obtained are heated and bonded.

  In the present invention, the recording content of the recording sheet can be hidden by forming an image on the transparent sheet according to the recording content of the recording sheet. Further, it is possible to cope with continuous printing of different print information for each sheet, and the area can be selectively hidden according to the information concealment area for each sheet. As a result, an image forming apparatus for producing a print information concealment document such as a postcard for pressure bonding, which is responsive to demand, can be provided.

  Next, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings.

[Entire configuration of image forming apparatus]
First, the overall configuration of the image forming apparatus will be described.

  FIG. 1 is a sectional view schematically showing an image forming apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 101 denotes an original platen glass. An original O is placed on the original platen glass 101 in accordance with a predetermined placement standard with an image surface facing downward, and an original pressure bonding plate 102 is placed over the original O. To do. When the copy start key is pressed, the image photoelectric reading device (reader unit) 103 including the moving optical system operates to photoelectrically read the image information of the downward image surface of the document O on the document table glass 101. An original document feeder (ADF, RDF) may be mounted on the platen glass 101 to automatically feed the document onto the platen glass 101.

  Based on the read information, an image is formed on the recording sheet by the image forming means. The image forming unit of the present embodiment uses an electrophotographic system in which toner is transferred to a recording sheet, and this is fixed and recorded.

  As shown in FIG. 1, an image forming unit as an image forming unit is provided with a rotating drum type electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) 104 that can rotate in the clockwise direction of an arrow. At the time of image formation, the photosensitive drum 104 is rotated at a predetermined peripheral speed. The photosensitive drum 104 undergoes a uniform charging process with a predetermined polarity and potential by the charging device 105 during the rotation process. Then, when the uniformly charged photosensitive drum 104 is subjected to image exposure L by the image writing device 106, the potential of the exposed bright portion of the uniformly charged surface is attenuated to correspond to the exposure pattern on the photosensitive drum 104 surface. An electrostatic latent image is formed. In this embodiment, the image writing device 106 is a laser scanner, and is modulated in accordance with a time-series electric digital pixel signal of document image information photoelectrically read by the photoelectric reading device 103 described above in response to a command from a controller (not shown). The laser beam L is output, and the uniformly charged surface of the rotating photosensitive drum 104 is scanned and exposed to form an electrostatic latent image corresponding to the document image information.

  Next, the electrostatic latent image is developed as a toner image by the developing device 107, and at the position of the transfer charging device 108, a predetermined control is performed on the transfer portion which is a facing portion between the photosensitive drum 104 and the transfer charging device 108 by the sheet conveying means. The recording sheet S fed at the timing is electrostatically transferred from the surface of the photosensitive drum 104.

  In the case of the image forming apparatus according to the present embodiment, the sheet conveying unit includes a first sheet conveying unit that selectively conveys the recording sheet S from the four sheet cassettes 109 to 112 to the image forming unit; There is provided a second sheet conveying means for conveying the sheet from the (purpose tray) 113 to the image forming unit. Further, a reverse conveyance unit 114 that reverses the image-formed recording sheet and conveys it again to the image forming unit, and a double-side conveyance unit 124 that serves as a retransmission unit that conveys the recording sheet again to the image forming unit without being reversed are provided. Reference numeral 115 denotes a registration roller for timing-feeding the recording sheet to the transfer unit.

  The recording sheet that has received the transfer of the toner image from the surface of the photosensitive drum 104 at the transfer unit is separated from the surface of the photosensitive drum 104, conveyed to the fixing device 116, which is a fixing unit, and subjected to a fixing process of the unfixed toner image and discharged. It is discharged onto a discharge tray 118 outside the apparatus by a roller 117.

  On the other hand, the surface of the photosensitive drum 104 after separation of the recording sheet is cleaned by the cleaning device 119 after removal of adhering contaminants such as transfer residual toner, and is repeatedly used for image formation.

  In the double-sided copy mode, the first-side copied recording sheet exiting the fixing device 116 is turned upside down and introduced into the reverse conveyance unit 114, and is conveyed again to the transfer unit so that the second side of the recording sheet The toner image is transferred, and again passes through the fixing device 116 and is discharged as a double-sided copy onto a discharge tray 118 outside the device by a discharge roller 117.

[Image formation sequence]
The image forming apparatus according to the present exemplary embodiment transfers the toner image onto the recording sheet S as described above, and heats and pressurizes the toner image on the fixing device 116 to record information. At this time, in addition to the normal mode in which the recording sheet on which information is recorded is discharged as it is, there is a superposition mode in which the information recorded on the recording sheet can be concealed.

  In the superposition mode, a transparent sheet is superimposed on the image forming surface side of the recording sheet on which information is recorded, and the information on the recording sheet is recorded by adhering to the recording sheet by forming an image on the transparent sheet. This mode creates a secret document.

  Specifically, when the superposition mode is selected, the recording sheet S on which the toner image has been transferred and fixed is conveyed again to the image forming unit via the duplex conveying unit 124 without being reversed. At this time, a transparent sheet is set on the MP tray 113, and the transparent sheet is conveyed to the image forming unit by the second sheet conveying unit so as to overlap the image forming surface side of the recording sheet conveyed to the image forming unit. Then, an image (for example, a solid image) is formed on the transparent sheet so that the image forming area of the recording sheet is hidden by the image forming unit. Thereafter, the overlapping recording sheet and transparent sheet are conveyed to the fixing device 116, and the toner image on the transparent sheet is fixed by heating and pressurizing, and at the same time, the recording sheet and the transparent sheet are bonded by the heating. .

  The superposition mode sequence is controlled by a control unit 200 having a CPU 201, a ROM 202, and a RAM 203 as shown in FIG. That is, based on signals input from the sheet sensor 210, the operation unit 211, and the like arranged at predetermined positions on the sheet conveyance path, the first conveyance unit, the second conveyance unit, or the A roller driving motor 212 that drives each roller of the retransmission unit, a fixing heater 213 that heats the fixing device 116, and the like are driven. The control unit 200 also controls the image forming operation of the above-described image forming unit.

  Here, the information secret document creation sequence will be described with reference to the flowchart of FIG.

  First, the user selects a normal mode in which an image is formed on a recording sheet and discharged as it is, or a superposition mode in which a transparent sheet is superimposed on an image-formed recording sheet to conceal recording information (S101). When the user selects the normal output mode, the process proceeds to the normal output mode described above (S102).

  When the user selects the overlay mode, sheet size information of the transparent sheet set on the MP tray 113 by the user used in the overlay mode is obtained (S103). The size information may be obtained from a sheet sensor that detects the sheet size set on the MP tray 113, or may be input from the operation unit by the user.

  At this time, since the sizes of the recording sheet S and the transparent sheet S1 used for superposition depend on the position of the mask print area T of the recording sheet S, they do not have to be the same. However, if the mask printing area T of the recording sheet S is arbitrarily designated for each sheet, the recording sheet S size is desirably the same as or larger than the transparent sheet S1 size.

  Next, the user inputs a print area to be masked on the recording sheet S, that is, a location to be concealed in an image formed on the recording sheet S (S104). Here, a method for inputting the mask print area will be described. In the case of copying, the document information read by the image photoelectric reading device (reader unit) 103 is displayed on a main body display (not shown), the user designates a print area to be masked on the screen from the operation unit, and inputs the mask print area. Is completed. In the case of printing, the user designates a print area to be masked on a personal computer display (not shown), and the mask print area input is completed.

  After the above operations are completed, a printing operation is started on the image forming apparatus main body by operating the start key of the operation unit (S105).

  The printing operation of the image forming apparatus main body according to the present embodiment will be described with reference to FIG.

  The recording sheet S is fed from the selected sheet cassettes 109 to 112 in the same manner as in the normal mode, and the image is transferred by the transfer unit and conveyed to the fixing device 116. Here, in the present embodiment, the fixing temperature of the recording sheet S is set to 150 ° C. (S106). In the normal mode, the temperature is about 170 ° C., whereas in the superposition mode, it is set lower than in the normal mode. The fixing temperature 150 ° C. of the recording sheet S is a temperature at which the toner image is not peeled off from the recording sheet S until the sheet is conveyed, but the toner is not sufficiently dissolved. Since the fixing temperature varies depending on the configuration of the fixing device 116 and the sheet conveying speed, it may be changed depending on the main body conditions.

  Thereafter, as shown in FIG. 4, the recording sheet S is not guided to the reverse conveyance unit 114 side but is guided to the double-sided conveyance unit 124 side by the conveyance switching member 120 (S107). Therefore, since the recording sheet S is conveyed without being reversed, the recording sheet S is conveyed so that the printing surface side is again on the photosensitive drum 104 surface side.

  As shown in FIG. 4, when the recording sheet S is being conveyed in the double-sided conveyance unit 124, the transparent sheet S1 stacked on the MP tray 113 stops the leading edge of the sheet as shown in FIG. The multi-pre-registration roller 122 is conveyed and waits as it is (S108). The transparent sheet S1 is a sheet whose back side is visually recognizable, such as an OHP sheet or a mylar sheet, and may be a translucent sheet as long as the back side is visible. In this embodiment, an OHP sheet is used. The transparent sheet is made of a material that can be charged by rubbing with a brush, as will be described later.

  Below the multi pre-registration roller 122 and on the upstream side in the transport direction of the transparent sheet, sheet charging means for charging the transparent sheet transported by the multi-pre-registration roller 122 is provided. In the present embodiment, as shown in FIGS. 5A and 5B, a fur brush 123 formed of conductive rayon hair is provided as a sheet charging unit.

  As shown in FIGS. 5A and 5B, the fur brush 123 contacts the lower surface of the transparent sheet about 30 mm upstream from the pre-registration roller when the leading edge of the transparent sheet S1 reaches the multi-pre-registration roller 122. And is provided so as to be rotatable.

  Then, when the transparent sheet S1 is conveyed by the second sheet conveying means and the leading end reaches the multiple pre-registration roller 122, the fur brush 123 starts to rotate while being in contact with the transparent sheet (S109).

  As a result, the transparent sheet S1 conveyed to the image forming unit is charged on the lower surface side (the surface side in contact with the recording sheet) and reliably adsorbs to the overlapping recording sheets S. However, the leading edge of the transparent sheet S1 of about 30 mm does not enter the rotation region of the fur brush 123. For this reason, the transparent sheet S1 is charged by the fur brush 123 except for the front end in the transport direction.

  In this way, since the leading edge of the transparent sheet is a non-charged region, the adhesive strength with the recording sheet S is small in this portion. Thereby, as will be described later, it is possible to align the leading end positions of the recording sheet S and the transparent sheet S1 at the position of the registration roller 115. Note that in order to further improve the attractive force between sheets by charging, a bias may be applied to charge the fur brush 123 more efficiently.

  Whether or not the recording sheet S conveyed from the double-sided conveyance unit 124 has passed the pre-registration roller 121 in the sheet conveyance path by the first sheet conveyance means is detected by a sheet sensor (not shown) immediately before the pre-registration roller 121. It is determined (S110). At the same time as determining that the recording sheet S has passed the pre-registration roller 121, the multi-pre-registration roller 122 is driven and the transparent sheet S1 waiting at the position of the multi-pre-registration roller 122 is conveyed toward the registration roller 115. (S111).

  As shown in FIG. 5B, the recording sheet S and the transparent sheet S1 are pressed by the pre-registration roller 121 and the multi-pre-registration roller 122, respectively, so that the recording sheet S and the transparent sheet S1 are abutted against the stopped registration roller 115. Match (S112). At this time, the leading end portion of the transparent sheet S1 is not charged as described above, and has a low adsorptivity with the recording sheet, so that the two overlapping sheet leading end positions can be easily aligned.

  Thereafter, the two overlapped sheets by the registration roller 115 are conveyed to the transfer unit. At this time, since the lower surface of the transparent sheet S <b> 1 is charged, the transparent sheet S <b> 1 is reliably adsorbed to the recording sheet S and is adsorbed and conveyed without being peeled off even if it passes through the registration roller 115. Moreover, since the transparent sheet leading end portion region having low adsorbability is very small when viewed from the entire sheet region, both sheets are conveyed while being adsorbed.

  Therefore, the transparent sheet leading end portion as the non-charged region does not become an obstacle to leading end alignment with the recording sheet by not charging the portion, and the entire transparent sheet is not charged by charging the remaining portion. An area that can be adsorbed and transported.

  In this embodiment, the printing information of the recording sheet S is masked (invisible) by printing a solid image M (a uniform toner image) on the transparent sheet S1 in accordance with the printing content of the recording sheet S. It is possible. Here, a solid image is formed on the transparent sheet based on the information set and input as the print area to be masked in S104.

  That is, as shown in FIG. 6, the control unit 200 controls the image forming unit to form a solid image M on the transparent sheet S1 so as to cover the area of the mask print region T on the recording sheet S (S113). . As a result, the contents of the mask print area T are not visible from the transparent sheet S1 side.

  Next, the recording sheet S and the transparent sheet S1 being sucked and conveyed are conveyed to the fixing device 116 as shown in FIG. 7, and the heat and pressure of the fixing device 116 are applied.

  In this embodiment, when the integrated recording sheet S and the transparent sheet S1 are fixed, the toner fixing temperature is set to 180 ° C., and is set to 30 ° C. higher than the fixing temperature 150 ° C. of the recording sheet S described above ( S114). Also, it is set to be about 10 ° higher than the fixing temperature in the normal mode. As a result, the solid image M on the transparent sheet S1 is also sufficiently fixed on the transparent sheet S1.

  Simultaneously with the toner fixing to the transparent sheet S1, the toner on the recording sheet S is further melted and fixed on the recording sheet S, and the melted toner adheres the recording sheet S and the transparent sheet S1. Then, the pressure-bonding sheet (recording sheet S and transparent sheet S1) that is sufficiently pressed and integrated is discharged (S115).

  As a result, the adhesive force between the recording sheet S and the transparent sheet S1 is maintained even after being discharged from the apparatus main body, and functions as a print information concealment document as a pressure-bonding sheet.

  Then, whether or not the next recording sheet S is also output in the superposition mode is determined by user input (S116). If it is not the superposition mode, the operation sequence of the superposition mode of this embodiment is completed.

  The adhesion between the recording sheet S and the transparent sheet S1 of the present embodiment is due to the dissolution of the toner transferred to the recording sheet, and this adhesion force is not so strong. For this reason, it is possible to easily peel off the transparent sheet from the recording sheet, and the same handling as a so-called crimping postcard is possible.

  Note that if the amount of toner transferred to the recording sheet S is small, it may be difficult to ensure the adhesive force with the transparent sheet S1. In that case, it is preferable to transfer a transparent toner (toner that is transparent even when an image is formed) onto the first recording sheet S, and to secure an adhesive force with the transparent sheet S1 by dissolving the transparent toner. .

  In the present embodiment, only one recording sheet has been described. Of course, it is possible to respond even when continuously printing different print information for each sheet, and it can be selectively performed according to the information concealment area for each sheet. It is possible to hide the area.

1 is a cross-sectional view illustrating a configuration of an image forming apparatus. It is a block diagram of the control composition which performs superposition mode. It is a flowchart which shows the execution procedure of superposition mode. FIG. 6 is a cross-sectional view illustrating a sheet conveying method in a superposition mode. It is sectional drawing which shows the sheet conveying method of a resist part. It is sectional drawing which shows the sheet conveying method of a transfer part. 10 is a cross-sectional view illustrating a sheet conveying method of the fixing device.

Explanation of symbols

O ... Original S ... Recording sheet S1 ... Transparent sheet
101… Platen glass
102 ... Original pressure plate
103… Photoelectric reader
104… Photosensitive drum
105… Charging device
106… Image writing device
107… Developing device
108… Transfer charging device
109 to 112 ... sheet cassette
113… MP tray
114… Reversal transfer section
115… Registration roller
116 ... Fixing device
120 ... Conveyance switching member
121… Pre-registration roller
122… Multi-pre-registration roller
123… Fur brush
124… Double-sided conveyance section
200… Control unit
201 ... CPU
202… ROM
203… RAM
210… Seat sensor
212… Roller drive motor

Claims (6)

First sheet conveying means for conveying a recording sheet;
Image forming means for forming a toner image on a sheet;
Fixing means for fixing the image by heating the sheet on which the toner image is formed;
Re-sending means for transporting the image-formed recording sheet to the image forming means again;
A second sheet conveying means for conveying the image-formed recording sheet so that the transparent sheet overlaps the image forming surface side of the recording sheet when the recording sheet is conveyed again to the image forming means;
Have
An image forming apparatus comprising: forming an image on a transparent sheet superimposed on the recording sheet; and heating and bonding the recording sheet and the transparent sheet superimposed by the fixing unit.   2. The heating by the fixing unit is set to a higher temperature when heating the stacked recording sheet and the transparent sheet than when fixing the toner image formed on the recording sheet. Image forming apparatus.   The image forming apparatus according to claim 1, further comprising a sheet charging unit configured to charge the transparent sheet before the transparent sheet overlaps the recording sheet.   The image forming apparatus according to claim 3, wherein the charging unit charges the recording sheet except for a leading end portion in a conveyance direction.   The image forming apparatus according to claim 1, wherein a transparent toner is transferred when a toner image is formed on the recording sheet.   6. A control unit that controls the image forming unit to form an image on a transparent sheet based on information set and inputted as a location to be concealed in an image formed on a recording sheet. The image forming apparatus according to any one of the above.

Images