Image forming apparatus, enclosing state inspection apparatus, envelope, and enclosing state inspection method

Abstract

To facilitate accurate inspection of a sealed state of an envelope where a plurality of sheets are sealed.SOLUTION: An image formation device 100 includes an imaging part 6S capable of forming an image capable of absorbing infrared rays, and a resist roller pair 28 (conveyance means) for conveying a sheet P toward the imaging part 6S. The imaging part 6S is configured to form images G1 to G4 for identification that are different according to sheets P1 to P4 in any one of an end face excluding a surface and a rear face, a side end part reaching the surface and the rear face over the end face, and a margin part of the surface or the rear face, on the sheet P conveyed by the resist roller pair 28.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an image forming device that forms an image on a sheet such as paper, an enclosure state inspection device that inspects the enclosure state of multiple sheets enclosed in an envelope, an envelope into which multiple sheets are enclosed, and an enclosure state inspection method that inspects the enclosure state of multiple sheets enclosed in an envelope. [Background technology]

[0002] 2. Description of the Related Art Conventionally, devices (enclosure inspection devices) for inspecting a sheet (enclosure) enclosed in an envelope have been known (see, for example, Patent Document 1).

[0003] In detail, the device disclosed in Patent Document 1 irradiates the surface of an envelope containing an enclosure with near-infrared light of a specific wavelength, and captures an image formed by absorbing or reflecting the near-infrared light in an area of ​​the enclosure where page information, etc. is printed, using an imaging element.The enclosure inside the envelope is then inspected based on the captured image. Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional techniques have not been able to accurately inspect envelopes containing multiple sheets (enclosures) for the presence or absence of defects such as missing or misprinted sheets.

[0005] This invention has been made to solve the above-mentioned problems, and aims to provide an image forming apparatus, an enclosure state inspection apparatus, an envelope, and an enclosure state inspection method that make it easier to accurately inspect the enclosure state in an envelope containing multiple sheets. [Means for solving the problem]

[0006] The image forming apparatus of the present invention includes an image forming unit capable of forming an image capable of absorbing infrared rays, and a transport means for transporting a sheet toward the image forming unit, and the image forming unit is capable of forming a different identification image for each sheet on any of the end faces excluding the front and back sides of the sheet transported by the transport means, the side end parts extending across the end faces to the front and back sides, and the margins of the front or back sides. The identification image is for identifying the order of stacking when a plurality of sheets are inserted into a desired envelope. It is something. Effect of the Invention

[0007] According to the present invention, it is possible to provide an image forming apparatus, an inclusion state inspection apparatus, an envelope, and an inclusion state inspection method that facilitate accurate inspection of the inclusion state of an envelope containing multiple sheets. [Brief description of the drawings]

[0008] [Figure 1] 1 is an overall configuration diagram showing an image forming apparatus according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a diagram showing the configuration of an imaging unit. [Diagram 3] 1 is a diagram showing a state in which different identification images are formed on a plurality of sheets in an image forming apparatus; [Figure 4] 11A and 11B are diagrams illustrating an operation of forming an identification image on a side edge portion of the leading edge of a sheet in an image forming unit. [Diagram 5] 13A and 13B are diagrams illustrating an operation of forming an identification image on a side edge portion of the leading edge of a sheet in an image forming unit according to another embodiment. [Figure 6] 5 is a flowchart showing an example of control during printing in the image forming apparatus. [Figure 7] FIG. 1 shows an envelope containing multiple sheets. [Figure 8] 13 is a diagram showing a state in which an enclosure state in an envelope is being inspected by an enclosure state inspection device; FIG. [Figure 9] (A) is a diagram showing an envelope with a normal sealed state, and (B) to (D) are diagrams showing envelopes with an abnormal sealed state. [Figure 10]FIG. 13 is a diagram showing a state in which different identification images are formed on a plurality of sheets in an image forming apparatus according to a first modified example. [Figure 11] FIG. 13 is a diagram showing a state in which different identification images are formed on a plurality of sheets in an image forming apparatus according to a second modified example. [Figure 12] FIG. 12 shows an envelope containing the sheets of FIG. 11. [Figure 13] FIG. 13 is a diagram showing a state in which different identification images are formed on a plurality of sheets in an image forming apparatus according to a third modified example. [Figure 14] FIG. 13 is a diagram showing an image forming apparatus according to a fourth modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and the duplicated description will be appropriately simplified or omitted.

[0010] First, the overall configuration and operation of an image forming apparatus 100 will be described with reference to FIGS. FIG. 1 is a diagram showing the configuration of an electrophotographic printer as an image forming apparatus, and FIG. 2 is an enlarged view showing its image forming section. As shown in FIG. 1, a writing device 7 is provided on the top of the image forming apparatus main body 1, and two image creating units 6K and 6S (image forming units) are provided below the writing device 7.

[0011] The first image creating unit 6K is for forming a normal image (an image based on a user's print command) on the sheet P (an image creating unit for printing normal images). Specifically, in this embodiment, the first image creating unit 6K forms an image using black toner that is generally used as the toner T (developer). The image formed by the first image creating unit 6K is an image that can be viewed under conditions where visible light is projected (a normal usage environment).

[0012] In contrast, the second image forming unit 6S is disposed downstream (downstream in the conveying direction of the sheet P) with respect to the first image forming unit 6K. The second image forming unit 6S is for forming identification images G1-4 (see Figs. 3, 4, etc.) on the sheet P that are different from normal images (image forming unit for printing identification images). Note that these "identification images G1-4" are for identifying the stacking order (sequence) when multiple sheets P1-P4 (after printing) are inserted into a desired envelope F (see Fig. 7), and in this embodiment, they are formed on the side end portions (portions that extend across the end faces (portions excluding the front and back surfaces) to the front and back surfaces) of the sheets P1-P4 as shown in Fig. 4(C). The second image forming unit 6S is an image forming unit capable of forming images that are invisible under conditions where visible light is projected and that can absorb infrared light. Therefore, the identification images G1-G4 formed by the second image forming unit 6S are different from the normal images formed by the first image forming unit 6K, and cannot be seen as transparent by the naked eye under normal use conditions. The identification images G1-G4 thus formed on the sheets P1-P4 are read by an enclosure state inspection device 200 (see FIG. 8) that uses infrared light, which will be described in detail later. The second image forming unit 6S is configured almost the same as the first image forming unit 6K, except for the type of toner contained in the developing device 5. The toner used in the second image forming unit 6S is invisible under conditions where visible light is projected as described above and can absorb infrared rays, and is called "IR toner." As such an "IR toner," for example, the one disclosed in JP 2019-117352 A can be used.

[0013] 2, the first and second image forming units 6S and 6K are both process cartridges in which the photosensitive drum 1 as an image carrier, the charging device 4, the developing device 5, and the cleaning device 2 arranged around the photosensitive drum 1 are integrated. Then, an image forming process (charging process, exposure process, developing process, transfer process, cleaning process, and discharging process) is performed on the photosensitive drum 1, and an image is formed on the photosensitive drum 1. Note that the image formed on the photosensitive drum 1 is a black image in the case of the first image forming unit 6K, and a transparent image (not visible to the naked eye under normal use conditions) in the case of the second image forming unit 6S.

[0014] 2, a photoconductor drum 1 serving as an image carrier is rotated clockwise by a main motor, and the surface of the photoconductor drum 1 is uniformly charged at the position of a charging device 4 (charging process). Thereafter, the surface of the photosensitive drum 1 reaches a position irradiated with laser light L emitted from a writing device 7 (exposure device), and an electrostatic latent image is formed by exposure scanning at this position (exposure process).

[0015] Thereafter, the surface of the photosensitive drum 1 reaches a position facing the developing device 5 (developing roller 51), where the electrostatic latent image is developed to form a toner image (developing process). Thereafter, the surface of the photosensitive drum 1 reaches a position (transfer nip) facing the transfer roller 18, and at this position the toner image on the photosensitive drum 1 is transferred onto the sheet P (transfer process). At this time, a small amount of untransferred toner remains on the photosensitive drum 1.

[0016] Thereafter, the surface of the photosensitive drum 1 reaches a position opposite the cleaning device 2, at which point untransferred toner remaining on the photosensitive drum 1 is removed by the cleaning blade 2a and collected into the cleaning device 2 (this is the cleaning process). Finally, the surface of the photosensitive drum 1 reaches a position facing a charge eliminating device, where the residual potential on the photosensitive drum 1 is eliminated. Thus, a series of image forming processes carried out on the photosensitive drum 1 is completed.

[0017] Here, referring to Figure 1, the sheet P transported to the transfer nip position is transported from a paper feed unit 26 (paper feed cassette) arranged below the device main body 100 via a transport path K1 on which a paper feed roller 27, a pair of registration rollers 28, etc. are arranged. More specifically, a plurality of sheets P are stacked and stored in the sheet feed unit 26. When the sheet feed roller 27 is rotated counterclockwise in FIG.

[0018] The sheet P conveyed to the registration roller pair 28 (timing roller pair) is temporarily stopped at the roller nip position of the registration roller pair 28, where the rotational driving by the conveying motor 85 (see FIG. 4) has stopped. Then, in synchronization with the image on the photosensitive drum 1, the registration roller pair 28 is rotated and the sheet P is conveyed toward the transfer nip. More specifically, the sheet P passes from the position of the registration roller pair 28 through the transfer nip of the first image forming unit 6K and the transfer nip of the second image forming unit 6S in that order. In this way, the desired image is transferred to the desired position on the sheet P. In this manner, the pair of registration rollers 28 functions as a conveying unit that conveys the sheet P toward the image forming units 6S and 6K. The images formed by the first imaging unit 6K are formed within the normal image area of ​​the sheets P1-P4 (excluding the margins that become the edges). In contrast, the identification images G1-G4 formed by the second imaging unit 6S are formed outside the normal image area of ​​the sheets P1-P4 (the side edges of the sheets in this embodiment).

[0019] Thereafter, the sheet P onto which the image has been transferred at the transfer nip position is transported to the position of the fixing device 20. Then, at this position, the image transferred onto the surface is fixed onto the sheet P by heat and pressure from the fixing roller 21 and the pressure roller 22 (this is the fixing process). Thereafter, the sheet P passes through a discharge path K2 and is discharged to the outside of the apparatus by a pair of discharge rollers. The sheets P discharged to the outside of the apparatus by the pair of discharge rollers are sequentially stacked on a stack unit as printed matter. In this way, a series of image forming processes (printing operations in the "single-sided printing mode") in the image forming apparatus is completed.

[0020] In addition, in the present embodiment, the image forming apparatus 100 is configured to allow the user to select a "printing mode with identification image" in which a normal image is formed by the first image forming unit 6K using black toner and a transparent identification image G is formed by the second image forming unit 6S using IR toner, as well as a "normal printing mode" in which only a normal image is formed by using only the first image forming unit 6K, without forming an identification image G by the second image forming unit 6S. In order to select either the "normal printing mode" or the "identification image-added printing mode", the user operates the operation display panel 90 (see FIG. 1).

[0021] Here, the image forming apparatus 100 in this embodiment is provided with a double-sided conveying section 30 that turns over the sheet P after an image has been fixed on its front side by the fixing device 20 and guides it to the first imaging section 6K. When a mode in which an image is formed on both sides of sheet P (double-sided printing mode) is selected in image forming apparatus 100, sheet P after the fixing process with an image formed on the front side is not guided to discharge path K2, but is guided to double-sided conveying section 30, and then conveyed to the transfer nip position, where the desired image is formed in the normal image forming area on the back side by first image creating section 6K. Specifically, during double-sided printing, the sheet P with an image formed on its front side after the fixing process is transported to the inversion path K3, where the transport direction is reversed to invert the front and back sides, and then transported to the double-sided path K4 and transported again to the transfer nip via the transport path K1. Then, in the transfer nip, the image is transferred to the back side of the sheet P by the first image forming unit 6K. After the image is transferred to the back side at the transfer nip position, the sheet P passes through the second image forming unit 6S, and is transported again to the fixing device 20 position for the fixing process. Thereafter, the sheet P passes through the discharge path K2 and is discharged outside the device by the pair of paper discharge rollers. In this way, the double-sided printing operation in the image forming apparatus is completed.

[0022] Next, the configuration and operation of the developing device 5 in the image forming units 6S and 6K will be described in more detail with reference to FIG. The developing device 5 is composed of a developing roller 51 (developer carrier) that contacts the photosensitive drum 1, a doctor blade 52 (developer regulating member) that contacts the developing roller 51, a supply roller 53 that contacts the developing roller 51, an agitating member 54 that agitates the toner in the device, and the like. Toner T (single-component developer) is contained in the developing device 5. As described above, the toner T in the first image forming unit 6K is black toner, and the toner T in the second image forming unit 6S is IR toner.

[0023] The developing device 5 configured in this manner operates as follows. A portion of the toner T stirred and transported by the stirring member 54 in the developing device 5 is carried on the supply roller 53. The toner T carried on the supply roller 53 is frictionally charged by sliding contact with the developing roller 51, and a portion of the toner T is carried on the developing roller 51. The toner carried on the developing roller 51 is then adjusted to an appropriate amount by the doctor blade 52, and then reaches a position facing the photosensitive drum 1 (developing area). At this time, the toner on the developing roller 51 is frictionally charged by sliding contact with the doctor blade 52. In the developing area, the adjusted amount of toner adheres to the electrostatic latent image on the photosensitive drum 1, and a toner image is formed on the photosensitive drum 1. In addition, the electric field formed in the development area described above is due to the potential difference between the exposure potential (image area potential) formed on the surface of the photosensitive drum 1 by irradiation with laser light L and the development bias applied to the development roller 51 by the development power supply.

[0024] In this manner, the image forming apparatus 100 in this embodiment is provided with an image creating unit 6S (second image creating unit) capable of forming different identification images G1 to G4 (images for identifying the stacking order of the sheets P1 to P4 when inserted into an envelope F) for each of the sheets P1 to P4 on the side ends spanning the end faces to the front and back sides of the sheets P1 to P4 transported by a pair of registration rollers 28 as a transport means.

[0025] Here, the image forming unit 6S is configured so as to be capable of forming at least one of the number, positions, and shapes of the identification images G1 to G4 so as to be different for each of the sheets P1 to P4. In detail, referring to FIG. 3, in this embodiment, the image forming apparatus 100 performs the "printing mode with identification image", and a first identification image G1 consisting of one rectangular image is formed on one end side of the width direction (the direction perpendicular to the conveying direction indicated by the arrow in FIG. 3 (the vertical direction in FIG. 3) and perpendicular to the paper surface in FIG. 1) at the side end of the leading edge (leading edge in the conveying direction) of the sheet P1 to be printed first. Then, a second identification image G2 consisting of two rectangular images is formed shifted toward the other end side in the width direction at the leading edge side of the sheet P2 to be printed second. Furthermore, a third identification image G3 consisting of three rectangular images is formed shifted further toward the other end side in the width direction at the leading edge side of the sheet P3 to be printed third. Furthermore, a fourth identification image G4 consisting of four rectangular images is formed shifted further toward the other end side in the width direction at the leading edge side of the sheet P4 to be printed fourth. These identification images G1 to G4 are formed on the sheets P1 to P4 in a transfer process in the second image creating unit 6S after the transfer process of the normal image in the first image creating unit 6K has been performed.

[0026] The four sheets P1 to P4 printed in this manner by the image forming apparatus 100 are then inserted into an envelope F by the user (or by a dedicated inserting device) in the order of the first to fourth sheets P1 to P4 stacked from the top, as shown in Figure 7(A). Then, the difference in the number (and position) of each of the identification images G1-G4 (the number of rectangular images constituting one identification image G) is detected by an enclosure state inspection device 200 described later, and based on the detection result, it is determined whether the four sheets P1-P4 are properly inserted in the intended stacking order in the envelope F. That is, the image forming device 100 in this embodiment can easily and accurately inspect the insertion state of the envelope F containing the multiple sheets P1-P4.

[0027] Here, the image forming apparatus 100 in the present embodiment is provided with an adjustment means for adjusting at least one of the image formation timing for forming an image in the second image forming unit 6S and the transport timing for transporting the sheet P toward the second image forming unit 6S. By performing the adjustment by the adjustment means, it becomes possible to form an identification image G at the leading edge of the sheet P in the transport direction, as shown in Figs. 4(A) to (C). Specifically, in this embodiment, the image creation timing for forming an image in the second image creation unit 6S (this is the writing timing for forming a latent image corresponding to the identification image G on the photosensitive drum 1 by the writing device 7) is adjusted to form the identification image G on the side edge (particularly, the end face) of the leading edge of the sheet P. Particularly, in this embodiment, in order to ensure that the identification image G is formed on the end face of the leading edge of the sheet P, the identification image G is formed on the photosensitive drum 1 at a position slightly in front of the sheet leading edge. Thus, in this embodiment, only the writing device 7 functions as the adjustment means.

[0028] 5(A) to 5(C), in this embodiment, a linear speed difference between the photosensitive drum 1 and the transfer roller 18 can be instantaneously generated at the transfer nip just before the sheet P contacts the transfer roller 18 so that the identification image G is reliably formed at the side edge of the leading edge of the sheet P (the portion of both sides spanning the end faces, see FIG. 5(C)). Specifically, the motor driving the photosensitive drum 1 or the transfer roller 18 can be adjusted and controlled so that the linear speed relationship between the photosensitive drum 1 and the transfer roller 18 at the transfer nip just before the sheet P contacts the transfer roller 18 is "linear speed (surface speed) of the photosensitive drum 1>linear speed (surface speed) of the transfer roller 18." By performing such control, toner (identification image G) is accumulated between the photosensitive drum 1 and the transfer roller 18, as shown in FIG. 5(B), and the identification image G can be reliably formed on the side edge (particularly the end face) of the leading edge of the sheet P, as shown in FIG. 5(C).

[0029] As described above, in order to form the identification image G on the side edge of the leading edge of the sheet P, as shown in Fig. 4(B), it is necessary for the identification image G to be supported at the position of the transfer nip just before (or at the same time as) the leading edge (leading edge) of the sheet P is fed into the transfer nip. Therefore, as shown in Fig. 4(A), the writing timing by the writing device 7 is made earlier than during the transfer process of a normal image. Specifically, when the point in time when the sheet P is re-fed from the position of the registration roller pair 28 is set to 0 seconds, the writing start time T by the writing device 7 is expressed as follows, assuming that the transport distance from the registration roller pair 28 to the second image forming unit 6S is M, the distance from the writing position on the photosensitive drum 1 to the transfer nip is N, the process linear speed (and the sheet transport speed) is S, and the length in the transport direction of the identification image G formed on the photosensitive drum 1 is X: T = M / SN / S - (X / 2) / S ... (Equation 1) It becomes. By adjusting the write timing in this way, as shown in Fig. 4(C), it is possible to form an identification image G on the side edge of the leading edge of the sheet P. In this way, since it is possible to form an identification image G on the leading edge of the sheet P by simply adjusting the write timing without the need to increase the image area in the width direction, there are fewer design constraints.

[0030] In this embodiment, the identification image G is formed on the side edge of the leading end of the sheet P, but the identification image G can also be formed on the side edge of the trailing end of the sheet P. In this case, the writing start time T by the writing device 7 when the point in time when the sheet P is re-fed from the position of the registration roller pair 28 is set to 0 seconds is different from that of the above (Equation 1), and is expressed as follows: T = M / S + WN / S - (X / 2) / S ... (Equation 2) In the above formula (2), "W" is the length (size) of the sheet P in the conveying direction. Furthermore, when forming an identification image G at the rear end of the sheet P, it is possible to do so by simply adjusting the write timing without needing to increase the image area in the width direction, and therefore design constraints are reduced.

[0031] In the present embodiment, the identification image G is formed on the side edge of the leading edge (or trailing edge) of the sheet P by adjusting the image formation timing (write timing) at which the image is formed in the image forming unit 6S, but the identification image G may be formed on the side edge of the leading edge (or trailing edge) of the sheet P by adjusting only the transport timing at which the sheet P is transported toward the image forming unit 6S, or the image formation timing (write timing) and the transport timing may be adjusted separately. The adjustment of the "transport timing" here refers to the adjustment of the feed start timing by the registration roller pair 28. When the feed start timing by the registration roller pair 28 is adjusted in this way, the write timing (image formation timing) in the first image forming unit 6K is also adjusted so that the position of the normal image by the first image forming unit 6K does not shift in the sub-scanning direction (transport direction). In addition, in this embodiment, an identification image G is formed on the side edge of the leading (or trailing) end of sheet P in the "single-sided printing mode." However, in cases where printing on the back side at the side edge of sheet P is insufficient, an identification image G can also be formed on the side edge of the leading (or trailing) end of sheet P in the "double-sided printing mode" previously described using Figure 1.

[0032] Also, as shown in FIG. 4 etc., in the image forming apparatus 100 of the present embodiment, a scraper 19 (foreign matter removal means) for removing foreign matter adhering to the surface of the transfer roller 18 is installed so as to abut against the surface of the transfer roller 18. As previously described with reference to Fig. 4, the identification image G formed by the second image forming unit 6S is formed so as to be actively carried in the transfer nip, so the transfer roller 18 of the second image forming unit 6S is easily soiled with toner. Therefore, it is useful to provide a scraper 19 for the transfer roller 18 of the second image forming unit 6S.

[0033] In the image forming apparatus 100 in this embodiment, an identification image G is formed at the leading edge of the sheet P. However, as shown in the control flow of FIG. 6, the position at which the identification image G is formed on the sheet P (in the example of FIG. 6, it is either the leading edge, the trailing edge, or a side edge) can also be configured to be selectable by operating the operation display panel 90. 6, when a print command is issued by a user operating the operation display panel 90 (step S1), feeding of the sheet P from the paper feed unit 26 is started, and the sheet P is temporarily placed on standby at the position of the pair of registration rollers 28 (step S2). Based on the print information input in step S1, the control unit acquires image data related to printing and information related to the size of the sheet P (step S3). Thereafter, it is determined whether an identification image G is to be formed on the sheet P (step S4). That is, it is determined whether the "printing mode with identification image" or the "normal printing mode" is selected. As a result, if it is determined that the printing mode is "normal printing mode" in which no identification image G is formed, the pair of registration rollers 28 resumes feeding the sheet P (step S6), the first image forming unit 6K starts forming a normal image based on the print command of step S1 (step S8), and printing is terminated (step S10). On the other hand, if it is determined in step S4 that the mode is the "print mode with identification image" in which the identification image G is formed, it is determined where on the sheet P the identification image G is to be printed (step S5). As a result, if it is determined that the printing position of the identification image G is the leading edge of the sheet, the pair of registration rollers 28 resumes feeding the sheet P (step S6), the second image forming unit 6S starts forming the identification image G according to the write timing of (Formula 1) described above (step S7), and the first image forming unit 6K starts forming a normal image based on the print command of step S1 (step S8), and printing ends (step S10). On the other hand, if it is determined in step S5 that the printing position of the identification image G is the rear end of the sheet, the pair of registration rollers 28 resumes feeding the sheet P (step S6), the first image forming unit 6K starts forming a normal image based on the print command of step S1 (step S8), and the second image forming unit 6S starts forming the identification image G based on the write timing of (Equation 2) described above (step S9), and printing is terminated (step S10). Furthermore, if it is determined in step S5 that the printing position of the identification image G is the side end of the sheet (the end on one side or the other side in the width direction), the pair of registration rollers 28 resumes feeding the sheet P (step S6), the first image creating unit 6K starts forming a normal image based on the print command of step S1 (step S8), and the second image creating unit 6S starts forming the identification image G with the same writing timing as when the image is formed in the image area, and printing is terminated (step S10).

[0034] In the image forming apparatus 100 according to the present embodiment, the image forming unit 6S for transparent color is provided separately from the image forming unit 6K for black color, and the identification image G is formed on the sheet P. On the other hand, it is also possible to simultaneously form the normal image and the identification image G on the sheet P by only the black image forming unit 6K without providing the transparent image forming unit 6S. This is because the toner T used in the black image forming unit 6K contains carbon and is not transparent and is visible under conditions where visible light is projected, but is capable of absorbing infrared rays and can be inspected by infrared irradiation using the sealing state inspection device 200 described later. In this way, when no problem occurs even if the identification image G formed on the sheet P is visible, forming the identification image G on the sheet P using the black imaging unit 6K in this manner results in a smaller and less expensive image forming apparatus 100 than when a dedicated imaging unit 6S is installed separately.

[0035] Hereinafter, the enclosed state inspection device 200 that inspects the enclosed state of the sheets P1 to P4 in the envelope F will be described in detail with reference to FIG. 8 etc. 8, the enclosed state inspection device 200 is composed of an image reading unit 201, a judgment unit 205 (calculation unit), a memory unit 206, etc. The enclosed state inspection device 200 may be a fixed type having a platform on which the envelope F is placed, or may be a manual type (handy type). Referring to Figure 8, in this embodiment, an envelope F (with its top, bottom, left and right directions determined) is placed on a placement table not shown, and an enclosure state inspection device 200 (image reading unit 201) is fixedly installed so as to face one end surface within the envelope F (the side on which the identification images G1 to G4 of the four sheets P1 to P4 are located (see Figure 7 (B))).

[0036] Referring to FIG. 8, the image reading unit 201 irradiates infrared rays R1 onto an envelope F containing multiple sheets P1 to P4 on which identification images G1 to G4 have been formed, respectively, by the image forming apparatus 100, and reads the identification images G1 to G4 formed on the multiple sheets P1 to P4, respectively. More specifically, the image reading unit 201 is mainly composed of a light emitting unit 202 such as an infrared light emitting sensor, and a light receiving unit 203 such as a light receiving sensor (CCD camera). The light emitting unit 202 faces the side edge (identification images G1 to G4) of the envelope F (sheets P1 to P4) and irradiates the surface with infrared rays R1 over a wide area (the entire side edge). The light receiving unit 203 is disposed adjacent to the light emitting unit 202 and is capable of receiving infrared light R2 that is irradiated from the light emitting unit 202, passes through the envelope F, and is reflected by the entire side edge areas of the sheets P1 to P4.

[0037] Furthermore, the principle of how the image reading unit 201 reads an image will be described in detail with reference to FIG. When infrared rays are irradiated onto a relatively thin medium such as an envelope F, some of the infrared rays are reflected, but most of the infrared rays pass through the medium (envelope F). On the other hand, in this embodiment, the identification images G1 to G4 (IR toner) formed on the sheet P by the image forming unit 6S have the property of absorbing infrared rays. Therefore, among the infrared rays R1 irradiated from the light-emitting unit 202 and transmitted through the envelope F, those that reach the identification images G1 to G4 are absorbed by the identification images G1 to G4 and are not received by the light-receiving unit 203. On the other hand, among the infrared rays R1 irradiated from the light-emitting unit 202 and transmitted through the envelope F, those that reach the parts where the identification images G1 to G4 are not formed are reflected there, and the reflected infrared rays R2 are transmitted through the envelope F again and then received by the light-receiving unit 203. Then, when the light-receiving unit 203 receives the infrared rays R2, the charge in the area where the light is received changes, and an output different from that of the area where the light is not received is generated. As a result, the image of the side end parts (end faces) of the sheets P1 to P4 on which the identification images G1 to G4 are formed is read by the image reading unit 201. Furthermore, based on the principle of image reading as described above, it can be said that the images formed by the image creating unit 6S (the identification attachment portions, which are the identification images G1 to G4) may have an infrared absorption rate or reflectance different from that of the sheets P1 to P4 themselves.

[0038] 8 and 9, the judgment unit 205 judges whether or not at least one of the following is present among the multiple sheets P1 to P4 enclosed in the envelope F: misprinting, missing pages, or excess number of sheets, based on the information read by the image reading unit 201 (information regarding the identification images G1 to G4). Here, "misprinting" of multiple sheets P1 to P4 enclosed in envelope F refers to a state in which sheets P1 to P4 are enclosed in a different stacking order as shown in Figure 9(B) compared to a predetermined number of sheets P1 to P4 enclosed in envelope F in the correct stacking order as shown in Figure 9(A). In addition, "missing sheets" among the multiple sheets P1 to P4 enclosed in an envelope F refers to a state in which sheets P1, P2, and P4 are enclosed with an insufficient number of sheets compared to the specified number of sheets P1 to P4 as shown in Figure 9(A), as shown in Figure 9(C). In addition, "excessive number" of sheets P1 to P4 enclosed in envelope F means that sheets P1 to P4 and P1 are enclosed in an excess number as shown in Figure 9(D) compared to the specified number of sheets P1 to P4 as shown in Figure 9(A). In this embodiment, the presence or absence of all of the above-mentioned "misprinting," "missing pages," and "excessive number of pages" is determined.

[0039] The judgment unit 205 compares the patterns of the identification images G1 to G4 of the multiple sheets P1 to P4 read by the image reading unit 201 with a reference pattern (which is in a normal state, see Figure 9 (A)) stored in the memory unit 206, and judges the presence or absence of "misprinting," "missing pages," or "excessive number of sheets" based on differences in at least one combination of the number, position, and shape of the identification images G1 to G4. In other words, the judgment unit 205 is provided with a position recognition means for recognizing the number of identification images G1 to G4, a position recognition means for recognizing the positions of the identification images G1 to G4, and a shape recognition means for recognizing the shapes of the identification images G1 to G4, and uses these to judge whether there is any "misprinting," "missing pages," or "excessive number of pages." In this embodiment, the insertion state inspection device 200 detects the difference in the number (and position) of each of the identification images G1 to G4 (the number of rectangular images that make up one identification image G), and based on the detection results, determines whether the four sheets P to P4 in the envelope F have been inserted correctly in the intended stacking order (there are no misprints, missing pages, or excess sheets).

[0040] The result of the determination thus made by the sealing state inspection device 200 is displayed on a display panel (not shown) installed in the sealing state inspection device 200. As a specific example, when the state of contents inside the envelope F is normal as shown in FIG. 9(A), a message indicating that the state is normal is displayed on the display panel. On the other hand, if the state of contents inside the envelope F is not normal as shown in FIGS. 9(B) to (C), the display panel will display the fact that there is an abnormal state and the details thereof.

[0041] By using such an enclosure state inspection device 200, a user can accurately know the enclosure state inside the envelope F even if the number of sheets P1 to P4 enclosed in the envelope F is large. This is particularly useful when a large number of envelopes F containing multiple documents (multiple sheets P1 to P4) with the same content must be prepared. It is preferable that the encapsulation state inspection device 200 is configured so that information regarding the multiple sheets P printed in the image forming device 100 and the identification images G formed thereon can be obtained from the image forming device 100 by wired or wireless communication. This allows the encapsulation state inspection device 200 to perform accurate inspection in response to changes in the form of the multiple sheets P and the identification images G depending on the usage pattern of the user.

[0042] Referring now to FIG. 7(B), the envelope F in which the multiple sheets P1-P4, on which identification images G1-G4 have been formed by the image forming apparatus 100, are enclosed is formed by folding a single sheet and pasting a portion of it to form a bag shape, and therefore has a thick portion F1 formed by three or more overlapping sheet surfaces and a non-thick portion F2 formed by two overlapping sheet surfaces. In the envelope F of this embodiment, as shown in Figure 7 (B), when viewed from the front side (or back side), multiple sheets P1 to P4 are enclosed inside so that the identification images G1 to G4 formed on the multiple sheets P1 to P4, respectively, are located in the non-thick portion F2 rather than the thick portion F1. This is because the infrared rays R1 and R2 are less likely to pass through the thick portion F1 than the non-thick portion F2, which prevents any difference in the accuracy of reading the identification images G1-G4 by the image reading unit 201. This configuration is particularly useful when the image reading unit 201 is positioned so that the infrared rays are irradiated from the front (or back) side of the envelope F to read the identification images G1-G4.

[0043] Also, referring to FIG. 7(B), in this embodiment, the envelope F is provided with a flap portion F3 (which is the portion to which the sheets P1 to P4 are glued after being enclosed) for inserting multiple sheets P1 to P4 into the envelope F from a predetermined direction (the direction indicated by the white arrow). Then, the multiple sheets P1 to P4 are inserted into an envelope F so that the identification images G1 to G4 formed on the multiple sheets P1 to P4, respectively, are positioned on the side of the envelope F that is parallel to the direction of the white arrow (a specified direction) (the position in Figure 9 (B)). With this configuration, the sheets P1 to P4 are easily inserted into the envelope F so that the identification images G1 to G4 are located in the non-thick portion F2.

[0044] The sheets P1 to P4 (enclosures) are inserted into the envelope in a substantially rectangular state (including the case where they are folded). If the identification images G1 to G4 formed on the sheets P1 to P4 (enclosures) are in a position that can be read by the image reading unit 201 while the sheets P1 to P4 (enclosures) are inserted into the envelope F, they can be inspected by the enclosure state inspection device 200, as in the present embodiment. Therefore, for example, even if multiple identification images G1 to G4 are located in different positions within an envelope F (not limited to the same side, but including different sides), as long as they are located in a position that can be read by the image reading unit 201, inspection by the sealing state inspection device 200 is possible, as in the present embodiment.

[0045] As such, in this embodiment, the image forming apparatus 100 and the enclosing state inspection apparatus 200 can be said to constitute a single system (enclosure state inspection system) for inspecting the enclosing state of multiple sheets P1 to P4 enclosed in an envelope F. Further, a method for inspecting the state of encapsulation in such a system includes: (1) forming different identification images G1 to G4 for each of sheets P1 to P4 on any of the end faces of sheet P excluding the front and back surfaces, the side edges extending across the end faces to the front and back surfaces, and the margins of the front or back surfaces (areas on which images are not normally formed, which are the edges of sheet P); (2) a step of irradiating an envelope F containing a plurality of sheets P1 to P4 on which identification images G1 to G4 are formed, with infrared rays R1, thereby reading the identification images G1 to G4 formed on the plurality of sheets P1 to P4, respectively; (3) determining whether or not the sheets P1 to P4 are inserted in the envelope F based on information obtained by reading the identification images G1 to G4; It can be said that it is equipped with these features.

[0046] <Variation 1> As shown in FIG. 10, the image forming apparatus 100 in the first variant is capable of forming different identification images G1 to G4 for each of the sheets P1 to P4 by the image forming unit 6S in the margins (areas where images are not normally formed, outside the area surrounded by the dashed line) on the front (or back) sides of the sheets P1 to P4. In particular, in the first modified example, the identification images G1 to G4 are formed in the margins on one widthwise end side (the upper side in FIG. 10) of the sheets P1 to P4 (not formed on the end faces). In such a case, the adjustment of the writing timing as previously described with reference to FIG. 4 is not necessary, and it is necessary to secure an image forming width in the width direction by the margins. Furthermore, even when identification images G1 to G4 are formed as in variant example 1, the inclusion state of sheets P1 to P4 in envelope F can be accurately inspected by the inclusion state inspection device 200 arranged in a position where such identification images G1 to G4 can be inspected. Furthermore, by forming different identification images G1 to G4 for each sheet P1 to P4 on any of the end faces excluding the front and back sides, the side edges spanning the end faces to the front and back sides, and the margins on the front or back sides, it becomes possible to accurately inspect the insertion status of sheets P1 to P4 in the envelope F.

[0047] <Variation 2> As shown in Figures 11 and 12, in variant example 2, the multiple sheets P1 to P4 on which the identification images G1 to G4 are formed by the image forming apparatus 100 are each index paper (a sheet having one side (tab portion Px) cut out so that the other portion protrudes), and before the sheets are inserted into the desired envelope F, each tab portion Px is visible from the front or back side without overlapping (is visible with some of it shifted), and the identification images G1 to G4 are formed on each tab portion Px (which is a portion visible from the front or back side). In the second modification, the identification images G1 to G4 are numbered "1" to "4" corresponding to the stacking order of the envelopes F (in a broad sense, these are "images with different shapes"). The image reading unit 201 that reads the identification images G1 to G4 in the envelope F containing such multiple sheets P1 to P4 is installed in a position facing the front or back surface (a position where the identification images G1 to G4 can be read) as shown in Figure 12. Furthermore, even when the identification images G1 to G4 are formed using index paper as in variant example 2, the inclusion state of the sheets P1 to P4 in the envelope F can be accurately inspected by the inclusion state inspection device 200 arranged in a position where such identification images G1 to G4 can be inspected.

[0048] <Variation 3> As shown in FIG. 13(A), the image forming apparatus 100 in the third variant is configured so that the positions of the identification images G1-G4 (in the example of FIG. 13(A), the positions are the margins on the front side of the leading edge of the sheets) are different for each of the sheets P1-P4 by the image creating unit 6S. Also, as shown in Figure 13(B), the image creating unit 6S is configured to be able to form the shapes of the identification images G1 to G4 (in the example of Figure 13(B), this is the widthwise length of the margin on the front side of the leading edge of the sheet) so that they differ for each of the sheets P1 to P4. In addition, although not shown in the figure, as long as the image creating unit 6S forms at least one of the number, position, and shape of the identification images G1 to G4 so that they are different for each sheet P1 to P4, the identification images G1 to G4 can be formed so as to be different for each sheet P1 to P4 by combining two or more of the number, position, and shape. Furthermore, even when identification images G1 to G4 are formed in this manner, the inclusion state of sheets P1 to P4 in envelope F can be accurately inspected by the inclusion state inspection device 200 arranged in a position where such identification images G1 to G4 can be inspected.

[0049] <Modification 4> As shown in FIG. 14, image forming apparatus 300 in variant example 4 is an inkjet color printer in which image forming units 3K, 3Y, 3M, and 3C for forming full-color normal images corresponding to four colors (black, yellow, magenta, and cyan) are arranged in parallel in the transport direction, and further image forming unit 3S for forming an identification image G is arranged in parallel. The five image forming units 3K, 3Y, 3M, 3C, and 3S have almost the same structure, except for the color (type) of ink they use. The main part of the image forming units 3K, 3Y, 3M, 3C, and 3S is composed of a piezoelectric actuator, and is provided with nozzles that eject ink, ink tanks filled with ink, a control board, and the like. Then, ink is sprayed sequentially from the image forming units 3K, 3Y, 3M, and 3C required for normal images onto the sheet P transported along the transport path based on write information, and a desired full-color normal image is formed on the sheet P. In addition, the image creating unit 3S for forming the identification image G forms an image using ink that is invisible under conditions where visible light is projected and that can absorb infrared light, and forms different identification images G1 to G4 for each of the sheets P1 to P4 at desired positions outside the normal image area on the sheet P on which the normal image is formed. Furthermore, even when the identification images G1 to G4 are formed using such an image forming device 300, the inclusion state of the sheets P1 to P4 in the envelope F can be accurately inspected by the inclusion state inspection device 200 arranged in a position where such identification images G1 to G4 can be inspected. Although the image forming apparatus 300 in the fourth modified example is an inkjet color printer, the identification images G1 to G4 can be formed in the same manner even if an electrophotographic color printer is used.

[0050] As described above, the image forming apparatus 100 in this embodiment is provided with the imaging unit 6S capable of forming an image capable of absorbing infrared rays, and the pair of registration rollers 28 (conveying means) that transports the sheet P toward the imaging unit 6S. The imaging unit 6S is configured to be capable of forming different identification images G1-G4 for each of the sheets P1-P4 on any of the end faces excluding the front and back sides of the sheet P transported by the pair of registration rollers 28, the side edges extending across the end faces to the front and back sides, and the margins of the front or back sides. This facilitates accurate inspection of the state of the envelope F containing the sheets P1 to P4.

[0051] In this embodiment, the image forming units 6K and 6S are configured as process cartridges to improve the maintainability of the image forming units 6K and 6S, but the image forming units 6K and 6S do not have to be configured as process cartridges. In this specification, the term "process cartridge" is defined as a unit in which at least one of a charging device for charging an image carrier, a developing device for developing a latent image formed on the image carrier, and a cleaning device for cleaning the image carrier is integrated with an image carrier, and is detachably installed in the main body of an image forming apparatus.

[0052] In this embodiment, a one-component developing device is used as the developing device 5 in the image forming units 6K and 6S, but a two-component developing device can also be used as the developing device. In that case, the developing device contains a two-component developer consisting of toner and carrier, and toner is appropriately replenished from a toner container to the developing device in accordance with the toner consumption in the developing device. Further, in the present embodiment, an example has been described in which four sheets P1 to P4 are enclosed in an envelope F, but the number of sheets P enclosed in an envelope is not limited to this. In the present embodiment, the transfer roller 18 is used as the transfer member that contacts the photosensitive drum 1 to form the transfer nip, but a transfer belt can also be used as the transfer member. Even in such cases, the same effects as those of this embodiment can be obtained.

[0053] It is clear that the present invention is not limited to the present embodiment, and that the embodiment may be appropriately modified within the scope of the technical concept of the present invention in addition to the modifications suggested in the present embodiment. Furthermore, the number, position, shape, etc. of the above-mentioned components are not limited to the present embodiment, and may be any number, position, shape, etc. suitable for implementing the present invention.

[0054] In this specification, the term "sheet" is defined not to be limited to paper, but to include all sheet-like recording media, such as index paper, coated paper, label paper, OHP sheets, etc. [Explanation of symbols]

[0055] 6K imaging unit (imaging unit for normal image printing), 6S image forming unit (image forming unit for printing identification images), 7 writing device (adjustment means), 28 registration roller pair (conveying means), 100 Image forming apparatus (image forming apparatus main body), 200 Encapsulation state inspection device, 201 Image reading unit, 202 light emitting unit, 203 light receiving unit, 205 determination unit, 206 storage unit, P, P1~P4 sheets (enclosure), G1~G4 Identification images (identification marks), Px tab section, F envelope, F1 thick part, F2 non-thick part, R1, R2 Infrared (infrared light). [Prior art documents] [Patent documents]

[0056] [Patent Document 1] JP 2018-58258 A

Claims

1. an imaging unit capable of forming an image capable of absorbing infrared rays; a conveying means for conveying a sheet toward the image forming unit; Equipped with the image forming unit is capable of forming a different identification image for each sheet on any of the end faces excluding the front surface and the back surface of the sheet conveyed by the conveying means, the side end portions extending across the end faces to the front surface and the back surface, and the margins of the front surface or the back surface; The image forming apparatus according to claim 1, wherein the identification image is for identifying an order of stacking when a plurality of sheets are enclosed in a desired envelope.

2. an imaging unit capable of forming an image capable of absorbing infrared rays; a conveying means for conveying a sheet toward the image forming unit; Equipped with the image forming unit is capable of forming a different identification image for each sheet on any of the end faces excluding the front surface and the back surface of the sheet conveyed by the conveying means, the side end portions extending across the end faces to the front surface and the back surface, and the margins of the front surface or the back surface; The image forming apparatus is characterized in that the multiple sheets on which the identification images are formed are each index paper, and each tab portion is visible from the front or back side without overlapping before being inserted into a desired envelope, and the identification image is formed on each of the tab portions.

3. an imaging unit capable of forming an image capable of absorbing infrared rays; a conveying means for conveying a sheet toward the image forming unit; an adjusting unit that adjusts at least one of an image forming timing for forming an image in the image forming unit and a transport timing for transporting a sheet toward the image forming unit; Equipped with the image forming unit is capable of forming a different identification image for each sheet on any of the end faces excluding the front surface and the back surface of the sheet conveyed by the conveying means, the side end portions extending across the end faces to the front surface and the back surface, and the margins of the front surface or the back surface; The image forming apparatus is characterized in that, by performing adjustment by the adjusting means, the identification image can be formed at a leading end or a trailing end in a conveying direction of the sheet.

4. an imaging unit capable of forming an image capable of absorbing infrared rays; a conveying means for conveying a sheet toward the image forming unit; Equipped with The imaging unit includes: A different identification image can be formed for each sheet on any of the end faces excluding the front surface and the back surface of the sheet conveyed by the conveying means, the side end portions extending across the end faces to the front surface and the back surface, and the margins of the front surface or the back surface, An image forming apparatus which forms an image using toner or ink which is invisible under conditions of visible light projection and which is capable of absorbing infrared light.

5. 5. The image forming apparatus according to claim 1, wherein the image forming unit is capable of forming the identification images so that at least one of the number, position, and shape of the identification images is different for each sheet.

6. 6. The image forming apparatus according to claim 1, wherein the image formed by said image forming unit has an infrared absorptivity or reflectivity different from that of the sheet itself.

7. An enclosure state inspection device comprising an image reading unit that irradiates infrared rays onto an envelope containing a plurality of sheets on which the identification images are respectively formed by the image forming device described in any one of claims 1 to 6, and reads the identification images formed on the plurality of sheets.

8. The enclosure state inspection device according to claim 7, further comprising a judgment unit that judges whether or not at least one of the following is present in the plurality of sheets enclosed in the envelope: misprinting, missing pages, or an excess of sheets, based on the information read by the image reading unit.

9. The sealing state inspection device described in claim 8, characterized in that the judgment unit compares the patterns of the identification images of the multiple sheets read by the image reading unit with a reference pattern stored in a memory unit, and determines the presence or absence based on differences in at least one combination of the number, position, and shape of the identification images.

10. an image forming apparatus including an image forming unit capable of forming an image capable of absorbing infrared rays and a conveying means for conveying a sheet toward the image forming unit; an image reading unit for irradiating an envelope containing a plurality of sheets on which identification images have been formed with infrared rays and reading the identification images formed on the plurality of sheets; a determination unit that determines whether or not at least one of misprinting, missing pages, and excess number of sheets is present in the plurality of sheets enclosed in the envelope based on the information read by the image reading unit; Equipped with the image forming unit is capable of forming the identification image, which differs for each sheet, on any of the end faces excluding the front surface and the back surface of the sheet conveyed by the conveying means, the side end portions extending across the end faces to the front surface and the back surface, and the margins of the front surface or the back surface; The determination unit compares the patterns of the identification images of the multiple sheets read by the image reading unit with a reference pattern stored in a memory unit, and determines the presence or absence based on differences in at least one combination of the number, position, and shape of the identification images.

11. An envelope for enclosing a plurality of sheets on which the identification images are formed by the image forming apparatus according to any one of claims 1 to 6, The sheet has a thick portion formed by overlapping three or more sheets, and a non-thick portion formed by overlapping two sheets, An envelope, wherein the plurality of sheets are enclosed so that the identification images formed on the respective sheets are positioned in the non-thick portion.

12. The envelope has a flap portion for inserting a plurality of sheets into the envelope from a predetermined direction; 12. The envelope according to claim 11, wherein the plurality of sheets are enclosed so that the identification images formed on the respective sheets are positioned on a side of the envelope that is parallel to the predetermined direction.

13. forming a different identification image for each sheet on any of the end faces of the sheet excluding the front and back surfaces, the side end portions extending across the end faces to the front and back surfaces, and the margins of the front and back surfaces; a step of irradiating an envelope containing a plurality of sheets on which the identification images are formed with infrared rays to read the identification images formed on the plurality of sheets; determining whether or not the plurality of sheets are defectively inserted in the envelope based on information obtained by reading the identification image; Equipped with The method for inspecting an enclosed state, wherein the identification image is for identifying the order in which a plurality of sheets are stacked when enclosed in a desired envelope.

Images