Printed matter and image forming device

Abstract

To provide a printed matter and an image forming device with which it is possible to easily grasp the position of a confidential information image.SOLUTION: A first confidential information image 80a and a second confidential information image 80b which are visually recognizable under a special condition are printed to a printed matter 300. Furthermore, an information image 81 that indicates the position information of the confidential information images 80a, 80b is printed to the printed matter 300. The information image 81 includes a first label image 81a that indicates the position of the first confidential information image 80a and which is formed at upper / lower edges and at both widthwise edges of a printing surface 300a, and a second label image 81b that indicates the position of the second confidential information image 80b and which is formed at upper / lower edges and at both widthwise edges of the printing surface 300a.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a printed matter and an image forming apparatus. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is known a printed matter on which a secret information image that is visible under special conditions and an information image that indicates the position information of the secret information image are printed.

[0003] Patent Document 1 describes a printed matter in which a landmark image serving as an information image indicating the position of a stealth image, which is a secret information image, is printed adjacent to the secret information image. A user can ascertain the position of the stealth image from the landmark image. Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is a risk that the information image may not be easily found. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the present invention provides a printed matter on which a secret information image visible under special conditions and an information image showing the position information of the secret information image are printed, wherein the secret information image is printed on an edge of the printing surface. and the secret information image and the information image are formed using image forming materials of Y, M, C and K colors. It is characterized by the following. [Effects of the Invention]

[0006] According to the present invention, the position of the secret information image can be easily grasped. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing a printed matter according to the present embodiment. [Figure 2] FIG. 10 is a diagram showing a printout on which a conventional secret information image is formed. [Figure 3]1A and 1B are diagrams illustrating conventional acquisition of a secret information image. [Figure 4] FIG. 10 is a diagram showing a first modified example of a printed matter. [Figure 5] FIG. 10 is a diagram showing a second modified example of the printed matter. [Figure 6] FIG. 10 is a diagram showing an example of a design of a mark image. [Figure 7] 10A and 10B are diagrams showing examples of printed matter having special shapes other than rectangular shapes. [Figure 8] FIG. 1 is an explanatory diagram showing the overall configuration of a printer as an image forming apparatus. [Figure 9] FIG. 10 is a diagram showing an example of a printed matter on which a secret information image is formed using general black toner. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a diagram showing a printed matter 300 according to this embodiment.

[0009] 1, the printed matter 300 of this embodiment is made up of a QR code (registered trademark) recording confidential information 82, and two difficult-to-see confidential information images 80a and 80b are formed on a sheet of paper P. The confidential information 82 may include information about the creator of the printed matter 300, a predetermined URL, and the like, as well as information about the number of confidential information images, such as "001 / 002" and "002 / 002."

[0010] The secret information images 80a and 80b are formed from a special light-reactive image-forming material that emits or develops color in the visible light range when exposed to light outside the visible light range, such as ultraviolet light, or a special light-absorbing image-forming material that absorbs light outside the visible light range, such as infrared light. Examples of special light-reactive image-forming materials include transparent fluorescent toner that fluoresces when exposed to ultraviolet light and transparent fluorescent ink that fluoresces when exposed to ultraviolet light. Examples of special light-absorbing image-forming materials include infrared-absorbing toner that absorbs infrared light and infrared-absorbing toner that absorbs infrared light. This embodiment will be described using an example of infrared-absorbing toner (hereinafter referred to as IR toner).

[0011] Furthermore, an information image 81 including position information of the secret information image is formed on the printed matter 300 of this embodiment. The information image 81 has a first target image 81a indicating the position of the first secret information image 80a and a second target image 81b indicating the position of the second secret information image 80b. The first target image 81a and the second target image 81b are formed of an image forming material visible under visible light. Examples of image forming materials visible under visible light include yellow (Y), magenta (M), cyan (C), and black (K) toners or inks.

[0012] The first target image 81a and the second target image 81b have different shapes, and the first target image 81a and the second target image 81b are formed on each of the four sides of the printing surface 300a. This makes it possible to determine the number of secret information images formed on the printing surface 300a from the number and shape of the target images formed on one side of the printing surface 300a. The size of each target image may be large enough to visually distinguish the difference in design between the first target image 81a and the second target image 81b, and is preferably about 7 to 8 points.

[0013] Furthermore, if priority is given to the visibility of each target image, it is preferable to print each target image in a tone darker than the background color, whereas if priority is given to design, it is preferable to print each target image in a tone equal to or lighter than the background color.

[0014] The mark images 81a and 81b printed at the widthwise ends are formed at the same vertical positions as the secret information image, and the mark images 81a and 81b printed at the vertical ends are formed at the same vertical positions as the secret information image. For example, as shown in FIG. 1, the first secret information image 80a is formed at a position D mm from one end in the widthwise direction and L mm from the top end. The first mark images 81a formed at the top and bottom ends are formed at a position D mm from one end in the widthwise direction, and the first mark images 81a formed at both widthwise ends are formed at a position L mm from the top end. The first secret information image 80a is located at the point where a virtual line f1a, indicated by a dotted line in the figure, connecting the first mark images 81a formed at the top and bottom ends intersects with a virtual line f2a, indicated by a dotted line in the figure, connecting the first mark images 81a formed at both widthwise ends. In addition, the second secret information image 80b is located at the intersection of a virtual line f1b connecting the second target images 81b formed at the top and bottom ends and a virtual line f2b connecting the second target images 81b formed at both ends in the width direction. Note that the virtual lines in Fig. 1 are not actually printed on the printing surface 300a.

[0015] FIG. 2 is a diagram showing a printed matter 300 on which a conventional secret information image 80 is formed. Since the secret information image 80 is formed with transparent IR toner, it is difficult to confirm with the naked eye under visible light where on the printing surface 300a the secret information image 80 is formed. The secret information image 80 can be seen from an image captured using an infrared camera 90, which is an information acquisition device, and it is common to read the secret information by capturing an image of the secret information image 80 with the infrared camera 90. A commonly used infrared camera 90 has a spot size 90a of about 20 mm in diameter.

[0016] Therefore, when the secret information image 80 is formed on a part of a commonly used A4 size paper (210 mm × 290 mm), for example, the user moves the infrared camera 90 as follows to locate the secret information image 80. That is, while looking at the captured image displayed on the image display unit of the infrared camera 90, the user moves the infrared camera 90 from the upper left of the paper to the left and right in the figure, as shown by the dashed line in FIG. 3, and gradually moves it downward in the figure. In this way, the secret information image 80 is located. As a result, it takes time to locate the secret information image 80 on the paper. Furthermore, when the infrared camera 90 captures the entire paper, the number of pixels constituting the secret information image 80 is small, and the secret information image 80 becomes a blurred image. As a result, the secret information image 80 cannot be recognized, and the secret information may not be read from the secret information image.

[0017] 1 has an information image 81 indicating the position of the secret information image 80. As a result, the position of the first secret information image 80a can be determined from the first target images 81a at the top and bottom ends of the information image 81 and the first target images 81a at both ends in the width direction. Therefore, by aligning the spot (photographing range) of the infrared camera 90 with the position of the first secret information image 80a determined from the first target images 81a, the first secret information image 80a can be photographed by the infrared camera 90. As a result, the secret information 82 can be read from the first secret information image 80a.

[0018] Similarly, the position of the second secret information image 80b can be determined from the second target images 81b at the top and bottom ends of the information image 81 and the second target images 81b at both ends in the width direction. Therefore, by aligning the spot (photographing range) of the infrared camera 90 with the position of the second secret information image 80b determined from the second target images 81b, the second secret information image 80b can be photographed by the infrared camera 90. This allows the secret information 82 to be read from the second secret information image 80b.

[0019] As described above, in the printed matter 300 of this embodiment, the secret information image 80 can be easily found from the information image 81. Furthermore, the target images 81a and 81b constituting the information image 81 are printed at the edge of the printing surface 300a. Other images, such as background images, are rarely printed up to the edge of the printing surface 300a. Therefore, the target images 81a and 81b formed at the edge are outside the printing area where other images are printed. This prevents the target images 81a and 81b from becoming difficult to see due to being blended in with other images, and makes it easy to find the target images 81a and 81b. Since the target images can be easily found in this way, the location of the secret information image can be easily grasped.

[0020] Furthermore, even if other images are formed up to the edge of the printing surface and the visibility of the target images 81a and 81b is somewhat impaired by the other images, the target images can be found by focusing only on the edge of the printing surface 300a. Therefore, even if the visibility is somewhat impaired by making the image thinner to prioritize design, the target images 81a and 81b of the information image can be found more easily than when searching for the target images from the entire printing surface.

[0021] FIG. 4 is a diagram showing a first modified example of the printed matter 300. As shown in FIG. In the printed matter of this first modification, the first target image 81a and the second target image 81b are made into arrow images. The shapes of the arrows of the first target image 81a and the second target image 81b are made different from each other, so that the number of confidential information images, etc. can be ascertained from the difference in shape.

[0022] The arrow of the first target image 81a points to the first secret information image 80a, and the arrow of the second target image 81b points to the second secret information image 80b. In the first modification, the first secret information image 80 can be photographed by the infrared camera 90 by aligning the spot (photographing range) of the infrared camera 90 with the point indicated by the arrow of the first target image 81a provided on each of the four sides of the printing surface 300a. This makes it possible to read the secret information 82 from the first secret information image 80a. Furthermore, by aligning the spot (photographing range) of the infrared camera 90 with the point indicated by the arrow of the second target image 81b provided on each of the four sides of the printing surface 300a, the second secret information image 80b can be photographed by the infrared camera 90. This allows the secret information 82 to be read from the second secret information image 80b.

[0023] FIG. 5 is a diagram showing a second modified example of the printed matter 300. As shown in FIG. In this second modified example, target images 81a and 81b are provided at the upper end and one end in the width direction of the printing surface 300a. In the second modified example, it can also be seen that the first secret information image 80a is located at the point where the point indicated by the first target image 81a at one end in the width direction intersects with the point indicated by the first target image 81a at the top end. Therefore, the position of the first secret information image 80a can be easily ascertained from these first target images 81a. Similarly, the position of the second secret information image 80b can be easily ascertained from the point indicated by the second target image 81b at the top end and the second target image 81b at one end in the width direction.

[0024] In the above description, information images (target images) are arranged on multiple sides of the printing surface 300a, but information images (target images) may be arranged on only one side. In such a configuration, the secret information image can be captured by moving the spot (photography range) of the infrared camera 90 from the target image in the direction indicated by the target image. Even with such a configuration, the secret information image can be found more easily than when searching for the secret information image by moving the spot (photography range) of the infrared camera 90 as shown in FIG. 3.

[0025] FIG. 6 is a diagram showing an example of a design of a mark image. The target image may be a figure as shown in FIG. 6(a) or an arrow shape as shown in FIG. 6(b). In the case of a figure, by making it tapered and making the upper tapered side in the figure the side of the secret information image, the user can recognize that the secret information image is at the end of the tapered part. Therefore, even from the figure shown in Figure 6(a), the position of the secret information image can be easily grasped based on the target image.

[0026] Using a figure as shown in Fig. 6(a) as the design of the target image has the effect of making it difficult for people who are unaware of the purpose of the target image to notice it. On the other hand, using an arrow as shown in Fig. 6(b) as the design of the target image has the advantage that it is easier to intuitively understand that the target image points to the location of the secret information image than when using a figure.

[0027] FIG. 7 is a diagram showing an example of a printed matter 300 having a special shape other than a rectangle. In recent years, there has been an increase in eye-catching, specially shaped printed materials, such as coasters, invitations, flyers, and shop cards, as shown in FIGS. 7(a) and 7(b). Such specially shaped printed materials can be used as props at parties and events, and, for example, numbers for lottery tickets or discount coupons can be printed as secret information images on the specially shaped printed materials. For example, secret information images 80a and 80b can be formed using transparent fluorescent ink or fluorescent toner that fluoresces when exposed to ultraviolet light. Then, at the party venue, the secret information images 80a and 80b can be illuminated by irradiating them with ultraviolet light, and secret information such as the names and identification numbers of party attendees can be developed and used to check attendees.

[0028] Even with a printed matter 300 having such a special shape, by making the shapes of the first target image 81a and the second target image 81b different from each other, it is possible to grasp the number of confidential information images, and to prevent forgetting to obtain confidential information, etc.

[0029] In the printed matter shown in Fig. 7(a), first target images 81a are arranged near position C in Fig. 7(a) where an end of the printing surface 300a intersects with a first virtual line f1a that passes through the first secret information image 80a, and near position D in Fig. 7(a). Also, the first target images 81a are arranged at position A in Fig. 7(a) where an end of the printing surface 300a intersects with a second virtual line f2a that passes through the first secret information image 80a and is perpendicular to the first virtual line f1a, and at position B in Fig. 7(a). Therefore, it can be easily understood from these first target images 81a that the first secret information image 80a is located at the intersection of the virtual line connecting the first target image 81a placed at position A and the first target image 81a placed at position B, and the virtual line connecting the first target image 81a placed at position C and the first target image 81a placed at position D.

[0030] Further, the second target images 81b are arranged near the position c in Fig. 7(a) where an end of the printing surface 300a intersects with a first virtual line f1b passing through the second secret information image 80b, and near the position d in Fig. 7(a). Further, the second target images 81b are arranged at the position a in Fig. 7(a) where an end of the printing surface 300a intersects with a second virtual line f2b passing through the second secret information image 80b and perpendicular to the first virtual line f1b, and at the position b in Fig. 7(a). Therefore, it can be easily recognized from these second target images 81b that the second secret information image 80b is located at the position of the intersection of a virtual line connecting the second target image 81b arranged at the position a and the second target image 81b arranged at the position b, and a virtual line connecting the second target image 81b arranged at the position c and the second target image 81b arranged at the position d.

[0031] 7(b), the first target images 81a and the second target images 81b are arranged in the same manner as in FIG. 7(a). Therefore, the position of the first secret information image 80a can be determined from the first target images 81a, and the position of the second secret information image 80b can be determined from the second target images 81b, in the same manner as in FIG. 7(a).

[0032] Next, an example of an image forming apparatus capable of printing the printed matter 300 of this embodiment will be described. The image forming device is not particularly limited as long as it forms the secret information image 80 on paper using IR toner that forms the secret information image 80. Therefore, the image forming device may be a printer, a copier, a facsimile, or a multifunction device that has at least two functions of a printer, a copier, a facsimile, and a scanner.

[0033] In the following description, the toner symbols for each component are "Y" for yellow toner (Y toner), "M" for magenta toner (M toner), and "C" for cyan toner (C toner).

[0034] First, the overall configuration and operation of the image forming apparatus will be described. FIG. 8 is an explanatory diagram showing the overall configuration of a printer 200 which is an image forming apparatus. The printer 200 of this embodiment is mainly composed of an image forming unit 1, a transfer unit 2, a recording medium supply unit 3, a fixing unit 4, a recording medium discharge unit 5, a control unit 30, and an image forming control unit 40.

[0035] The image forming unit 1 is provided with four process units 6Y, 6M, 6C, and 6IR as imaging units. Each process unit 6Y, 6M, 6C, and 6IR has the same configuration except for the type of toner used. Note that this embodiment does not include a process unit that uses black (K) toner, so color images and monochrome images are formed using only Y, M, and C color toners. A K process unit may be added, but this would have the disadvantage of increasing the size of the device.

[0036] Also, the IR process unit 6IR may be configured to be detachable, and a K process unit may be installed instead of the IR process unit. In this case, when forming an image without using IR toner, installing the K process unit allows color images or monochrome images to be formed using Y, M, C color toners and K toner.

[0037] In addition, the image forming apparatus may have all of the process units detachable and interchangeable in position, in which case the positional relationship between the IR toner image and each color toner image on the recording medium (the positional relationship in the toner image stacking direction) can be appropriately interchanged by interchanging the position of the IR process unit.

[0038] In this embodiment, each of the process units 6Y, 6M, 6C, and 6IR includes a photoconductor 7 as a latent image carrier, a photoconductor 7 as a latent image carrier that carries a latent image, and a charging roller 8 as charging means for charging the surface of the photoconductor 7. Each of the process units 6Y, 6M, 6C, and 6IR also includes a developing device 9 as developing means that develops the latent image on the photoconductor 7, and a photoconductor cleaning device 10 as latent image carrier cleaning means that cleans the surface of the photoconductor 7. Opposite each of the photoconductors 7 is provided an exposure device 11 as latent image forming means that forms a latent image on the surface of the photoconductor 7. In this embodiment, the exposure device 11 is an LED unit, but it may also be a laser beam scanning type using a laser diode.

[0039] The transfer unit 2 includes an endless intermediate transfer belt 12 as an intermediate transfer body onto which the toner image on the photoreceptor 7 is transferred, and a plurality of primary transfer rollers 13 as primary transfer means that primarily transfers the image on the photoreceptor 7 onto the intermediate transfer belt 12. The transfer unit 2 also includes a secondary transfer roller 14 as secondary transfer means that secondarily transfers the toner image transferred onto the intermediate transfer belt 12 onto a recording medium, and a belt cleaning device 17 as intermediate transfer body cleaning means that cleans the surface (outer peripheral surface) of the intermediate transfer belt 12.

[0040] The intermediate transfer belt 12 is stretched between a drive roller 15 and a driven roller 16, and rotates in a circular motion (rotation) as the drive roller 15 rotates. Each primary transfer roller 13 is arranged to press the intermediate transfer belt 12 against each photoconductor 7. As a result, a primary transfer nip is formed at the contact point between the intermediate transfer belt 12 and each photoconductor 7, where an image on each photoconductor 7 is transferred to the intermediate transfer belt 12. Meanwhile, the secondary transfer roller 14 is arranged to contact the portion of the intermediate transfer belt 12 that is wrapped around the drive roller 15. A secondary transfer nip is formed at the contact point between this secondary transfer roller 14 and the intermediate transfer belt 12, where an image on the intermediate transfer belt 12 is transferred to a recording medium.

[0041] The recording medium supply unit 3 has a paper feed cassette 18 as a recording medium storage unit, a paper feed roller 19 as a recording medium feeding means, and a timing roller 20 as a recording medium transport means. The paper feed cassette 18 stores paper P as a recording medium. The paper feed roller 19 feeds paper P from the paper feed cassette 18. The timing roller 20 transports paper P fed by the paper feed roller 19 to the secondary transfer nip at a predetermined timing. Note that the recording medium may be an OHP sheet, OHP film, cloth, or the like in addition to paper. In addition to plain paper, paper includes cardboard, postcards, envelopes, thin paper, coated paper (coated paper, art paper, etc.), textured paper such as Japanese paper, tracing paper, etc.

[0042] The fixing section 4 is provided with a fixing device 21 as a fixing means for fixing an image on the paper P. The fixing device 21 is mainly composed of a fixing roller 22 as a fixing member that is heated by a heat source such as a heater, and a pressure roller 23 as a pressure member that contacts the fixing roller 22 with a predetermined pressure to form a fixing nip.

[0043] The recording medium discharge section 5 is provided with a discharge roller 24 as a recording medium discharge means for discharging the paper P sent out from the fixing device 21 out of the device, and a discharge tray 25 as a recording medium loading section for loading the paper P discharged by the discharge roller 24.

[0044] The control unit 30 performs image processing on input image information from a reading device (scanner), a personal computer, etc., and also controls the printer 200 as a whole. In addition, the image forming control unit 40, under the control of the control unit 30, controls the image forming operations in each part of the printer 200 (image forming unit 1, transfer unit 2, recording medium supply unit 3, fixing unit 4, recording medium discharge unit 5, etc.).

[0045] In addition to the above-described components, the printer 200 of this embodiment is equipped with a plurality of toner cartridges 26 as powder containers that contain toner, which is a powder used in image formation. Each toner cartridge 26 contains toner of the same color as the toner in the corresponding developing device 9, and when the toner in the developing device 9 falls below a predetermined amount, toner is replenished from the toner cartridge 26. The printer 200 is also equipped with a waste toner container 27 as a powder container separate from the toner cartridges 26. This waste toner container 27 contains waste toner collected by the belt cleaning device 17 or the photoconductor cleaning device 10.

[0046] 8, the printer 200 of this embodiment is provided with a cover member 101 for opening and closing the top of the apparatus main body (image forming apparatus main body) 100. The cover member 101 is rotatable up and down around a rotation shaft 103 provided on the apparatus main body 100. Also, below the cover member 101, a container holding member 102 is disposed that detachably holds four toner cartridges 26. The container holding member 102 is rotatable up and down around another rotation shaft 104 provided on the apparatus main body 100.

[0047] In this embodiment, IR process unit 6IR is disposed on the most downstream side in the running direction of intermediate transfer belt 12, and color process units 6Y, 6M, and 6C are disposed upstream of it. This is because the IR toner image made of IR toner is formed closer to the recording medium than the color toner images made of Y, M, and C color toners on the recording medium. In other words, on intermediate transfer belt 12, a Y toner image, an M toner image, a C toner image, and an IR toner image are layered in this order from the belt side, and after secondary transfer, the IR toner image, a C toner image, an M toner image, and a Y toner image are layered on the recording medium in this order from the recording medium side.

[0048] By forming the IR toner image closer to the recording medium than the color toner image, the IR toner image is hidden by the color toner image, reducing its visibility, making it easier to ensure the confidentiality of the image formed by the IR toner image. However, the location of the IR process unit 6IR relative to the color process units 6Y, 6M, and 6C can be set as appropriate. Also, as described above, if the mounting positions of the process units 6Y, 6M, 6C, and 6IR are configured to be interchangeable, the position of the IR process unit can be freely interchanged.

[0049] Next, the basic operation of the printer 200 of this embodiment will be described. When the image forming operation starts, each photoconductor 7 is rotated, and the surface of each photoconductor 7 is uniformly charged to a predetermined polarity by the charging roller 8. Next, based on input image information from a reading device (scanner), a personal computer, etc., the exposure device 11 irradiates the charged surface of each photoconductor 7 with laser light to form a latent image (electrostatic latent image).

[0050] The latent image formed on each photoconductor 7 is a latent image based on monochrome image information obtained by decomposing a desired full-color image into color information of Y, M, and C. Specifically, a color conversion separation table is used to convert and separate the color information (RGB, YCM, etc.) of the input image information into color information (YMC) for the printer 200. This color conversion separation table is used to convert the input image information into color information of Y, M, and C, and generate decomposed monochrome image information. Each exposure device 11 for Y, M, and C forms a latent image of each color on the respective photoconductor 7 based on the image information of each color of Y, M, and C.

[0051] In this embodiment, the input image information specifies an image to be used as an IR image by an application on the PC, and IR image information is generated from the specified information. Alternatively, the image to be used as an IR image may be specified by a printer driver on the PC. The IR exposure device 11 forms an IR latent image on the photoconductor 7 of the IR process unit 6IR based on the IR image information.

[0052] Toner is supplied from the respective developing devices 9 to the Y, C, M, and IR latent images formed on the photoreceptors 7, and the latent images are developed into Y, C, M, and IR toner images. The toner images on each photoreceptor 7 are sequentially transferred onto the rotating intermediate transfer belt 12 in a superimposed state. More specifically, when the toner images on the photoreceptors 7 reach the primary transfer nip, a predetermined voltage is applied to the primary transfer roller 13 to form a transfer electric field, which sequentially transfers the toner images on the photoreceptors 7 onto the intermediate transfer belt 12. In this way, a full-color toner image (visible image) made of Y, C, and M toners and an IR toner image (invisible image) made of IR toner are formed on the surface of the intermediate transfer belt 12. Any toner on each photoreceptor 7 that was not completely transferred to the intermediate transfer belt 12 is removed by the photoreceptor cleaning device 10.

[0053] Furthermore, when the image forming operation is started, paper feed roller 19 rotates and feeds paper P from paper feed cassette 18. The transport of the fed paper P is temporarily stopped by timing roller 20. Thereafter, timing roller 20 starts to rotate at a predetermined timing, and paper P is transported to the secondary transfer nip in time with the toner image on intermediate transfer belt 12 reaching the secondary transfer nip.

[0054] When the paper P is transported to the secondary transfer nip, a predetermined voltage is applied to the secondary transfer roller 14, and a transfer electric field is formed in the secondary transfer nip. The toner images on the intermediate transfer belt 12 are transferred all at once to the paper P by the transfer electric field formed in the secondary transfer nip. At this time, the toner remaining on the intermediate transfer belt 12 is removed by the belt cleaning device 17.

[0055] Thereafter, the paper P is transported to a fixing device 21, where the toner image is heated and pressed by a fixing roller 22 and a pressure roller 23, thereby being fixed to the paper P. Then, the paper P is discharged out of the device by a paper discharge roller 24 and placed on a paper discharge tray 25.

[0056] The above description is of the image formation operation when forming a full-color image, but it is also possible to form an image using any one of the four process units 6Y, 6M, 6C, and 6IR, or to form an image using any two or three of the process units.

[0057] By creating a secret information image 80 and an information image 81 (target image) using application software on a personal computer and specifying the secret information image 80 as the IR image, the printed matter 300 shown in FIG. 1 etc. can be obtained.

[0058] Also, the printer 200 may automatically create the information image 81 (target image) to obtain the printed matter 300 shown in Fig. 1 etc. Specifically, when the secret information image 80 is designated as an IR image by a printer driver on a personal computer, a selection screen for selecting whether or not to create the information image 81 is displayed on the screen of the personal computer. If the user selects to create the information image 81, the user selects from a plurality of target image designs shown in Fig. 6, for example.

[0059] The PC side specifies the position of the specified secret information image 80, automatically generates a target image on the edge of the paper based on the specified position of the secret information image 80 and the design of the target image specified by the user, and transmits the generated target image as image data to the printer 200. Alternatively, the printer 200 side may automatically generate a target image on the edge of the paper based on the target image data specified by the user received from the PC and the position information of the secret information image 80.

[0060] Next, a printed matter on which a secret information image 80 is formed using a general black toner containing carbon that absorbs infrared rays will be described. Generally, black toner differs from other color toners (yellow, magenta, cyan) in that it contains carbon that absorbs infrared rays, making it possible to read it with an infrared camera. By using this property, it is possible to form a hidden information image 80 that is normally invisible with K toner but can be read with an infrared camera 90. As a result, it is possible to obtain a printed matter 300 on which a hidden information image 80 that is visible under special conditions is printed using Y, M, C, and K toners.

[0061] FIG. 9 is a diagram showing an example of a printed matter 300 on which a secret information image 80 is formed using ordinary black toner. 9(b), the secret information image 80 formed with black toner is a black image that is visible under visible light, unlike IR toner. Therefore, in order to make it difficult to be seen, it is preferable that the secret information image 80 is formed as a halftone image, that is, a light image.

[0062] The secret information image 80 formed with black toner shown in Fig. 9(b) is covered with the background image 180 created with Y, M, and C color toners shown in Fig. 9(a). As a result, as shown in Fig. 9(c), the secret information image 80 formed with black toner is hidden by the background image of Y, M, and C color toners, and the secret information image 80 becomes an image that is difficult to see.

[0063] An information image 81 (target image) is formed on the edge of the outer printed surface of the background image 180. When the position of the secret information image 80 identified based on this information image is photographed using an infrared camera 90, the secret information image 80 formed with black toner containing carbon that absorbs infrared rays is displayed on the image display unit of the infrared camera 90. This makes it possible to read the secret information.

[0064] The printed matter 300 shown in FIG. 9 can be formed by replacing the IR process unit 6IR in the image forming apparatus shown in FIG. 8 with a K process unit that uses black toner.

[0065] By arranging the K process unit downstream of the Y, M, and C process units in the movement direction of the intermediate transfer belt, the K toner image is primarily transferred onto the Y, M, and C toner images on the intermediate transfer belt. In this way, since the K toner image is placed on top of the Y, M, and C toner images on the intermediate transfer belt, the K toner image is positioned below the C toner image, M toner image, and Y toner image that form the background image 180 on the paper P. As a result, the confidential information image 80 formed with K toner is covered by the background image 180 made of Y, M, and C toners, making it difficult to see the confidential information image 80 formed with K toner.

[0066] Note that as long as the K toner image can be formed below the Y, M, and C color toner images on the paper, the configuration is not limited to disposing the K process unit downstream of the Y, M, and C color process units in the direction of movement of the intermediate transfer belt. Also, in the case of a direct transfer type image forming apparatus that transfers the toner image of the process unit directly to the paper, the K process unit is disposed upstream of the Y, M, and C process units in the direction of transport of the paper P. This allows the K toner image to be formed below the Y, M, and C toner images on the paper, and the secret information image 80 and information image formed with K toner can be covered by the background image 180 made of Y, M, and C toner.

[0067] Furthermore, since the secret information image 80 formed with K toner is colored, there is a risk that the secret information image 80 formed with K toner may be visible depending on the background image formed. Therefore, the background image 180 made of Y, M, and C colors may be formed multiple times to make the background image 180 thicker.

[0068] In the above, an example was described in which an infrared camera 90 equipped with an image display unit that displays the captured image was used as an information acquisition device for acquiring the secret information of the secret information image 80, but an infrared camera without an image display unit, such as a barcode reader that only outputs the read content, may also be used.

[0069] The above description is merely an example, and each of the following aspects provides unique effects. (Aspect 1) In a printed matter 300 on which a secret information image 80 visible under special conditions and an information image 81 indicating the position information of the secret information image 80 are printed, the information image 81 is printed on an edge of a printing surface 300a. Depending on the print layout, the secret information image may be printed near the center of the print surface, in which case the secret information image is printed in the print area of ​​another image, such as a background image. In Patent Document 1, in which the information image is printed adjacent to the secret information image, the information image is also printed in the print area of ​​the other image. Therefore, depending on the other image printed in this print area, the information image may blend in with the other image, making it difficult to see and making it difficult to find. In contrast, in aspect 1, the information image is printed on the edge of the printing surface. Generally, the printing area of ​​other images is rarely set to extend to the edge of the printing surface, so the information image printed on the edge of the printing surface will not be difficult to see because it will blend in with other images. This makes it easy to find the information image. Even if the printing area of ​​the other image is set up to the edge of the printing surface and the other image is formed up to the edge of the printing surface, making it difficult to see the information image due to the other image, it is only necessary to search for the information image only at the edge of the printing surface, and the information image can be found more easily than when searching for the information image from the entire printing surface.

[0070] (Aspect 2) In the first embodiment, the secret information image 80 is made of an image-forming material that absorbs infrared rays, such as IR toner or K toner. According to this, as explained in the embodiment, the secret information image 80 can be made difficult to see except under special conditions such as being captured by a special camera such as an infrared camera.

[0071] (Aspect 3) In the first or second embodiment, the secret information image 80 and the information image 81 are formed using image forming materials of Y, M, C, and K colors. 9, the secret information image 80 is formed using a K-color image forming material, and this secret information image 80 is covered with a background image 180 made of Y, M, and C-color image forming materials, thereby concealing the secret information image 80. The secret information image 80 concealed by the background image 180 made of Y, M, and C-color image forming materials can be made visible under special conditions, such as when it is photographed with a special camera such as an infrared camera.

[0072] (Aspect 4) In the first embodiment, the secret information image 80 is made of a transparent image-forming material that reacts to special light, such as a special light-reactive image-forming material. According to this, as explained in the embodiment, the secret information image 80 becomes difficult to see except under special conditions such as irradiation with special light such as ultraviolet light, and the secret information image 80 can be well concealed.

[0073] (Aspect 5) In any of embodiments 2 to 4, the imaging material is a toner. This makes it possible to form printed matter using an electrophotographic image forming apparatus.

[0074] (Aspect 6) In any of aspects 1 to 5, the information image 81 has a marker image that indicates the position of the secret information image 80, and the marker image has an arrow shape that indicates the position of the secret information image. As a result, as explained in the embodiment, it is easy to intuitively understand that the hidden information image is at the destination of the arrow, and the position of the hidden information image can be easily grasped from the target image.

[0075] (Aspect 7) In any of aspects 1 to 5, the information image 81 has a mark image that indicates the position of the secret information image, and the mark image has a shape that tapers toward the secret information image. This allows the user to recognize that there is a secret information image at the end of the tapered portion, as explained in the embodiment, and allows the user to easily grasp the position of the secret information image from the target image.

[0076] (Aspect 8) In the sixth or seventh aspect, the information image 81 has a plurality of target images of the same shape for one secret information image. This makes it possible to know that the position of the secret information image is at the point where the directions indicated by the plurality of target images intersect, and the position of the secret information image can be easily ascertained from the target images. Furthermore, by making the target images have the same shape as one secret information image, the user can intuitively recognize that target images of the same shape point to the position of the same secret information image.

[0077] (Aspect 9) In embodiment 8, the marking image is printed at the point where a first virtual line f1 passing through the secret information image 80 intersects with the edge of the printing surface, and at the point where a second virtual line f2 passing through the secret information image 80 and perpendicular to the first virtual line f1 intersects with the edge of the printing surface 300a. According to this, as explained in the embodiment, the position of the secret information image can be easily grasped from a plurality of target images.

[0078] (Aspect 10) In any of the sixth to ninth aspects, when there are a plurality of secret information images on the printing surface 300a, the shape of the mark image indicating the position of one secret information image is different from the shape of the mark image indicating the position of another secret information image. According to this, as explained in the embodiment, the number of secret information images 80 can be grasped from the number of target images with different shapes, and it is possible to prevent forgetting to read the secret information images 80.

[0079] (Aspect 11) In any of the sixth to tenth aspects, the same number of target images as the number of secret information images are printed on one side of the printing surface 300a. As a result, as explained in the embodiment, the number of secret information images 80 can be ascertained from the number of target images printed on one side of the printing surface, and forgetting to read the secret information images 80 can be prevented.

[0080] (Aspect 12) In an image forming apparatus that forms an image on a recording medium such as paper P to form a printed matter, the printed matter of any of the aspects 1 to 11 can be generated. [Explanation of symbols]

[0081] 80a: First secret information image 80b: Second secret information image 81: Informational image 81a: First target image 81b:Second marker image 82: Confidential Information 90: Infrared camera 90a: Spot size 200: Printer 300: Printed matter 300a: Printing surface P:Paper f1: First virtual line f2: Second virtual line [Prior art documents] [Patent documents]

[0082] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-132027

Claims

1. A printed matter on which a secret information image visible under special conditions and an information image showing the position information of the secret information image are printed, the information image is printed on an edge of the printing surface, The printed matter is characterized in that the secret information image and the information image are formed using image forming materials of Y, M, C and K colors.

2. A printed matter on which a secret information image visible under special conditions and an information image showing the position information of the secret information image are printed, the information image is printed on an edge of the printing surface, the information image has a marker image indicating the position of the secret information image, When there are a plurality of secret information images on the printing surface, A printed matter characterized in that a mark image indicating the position of a certain secret information image and a mark image indicating the position of another secret information image have different shapes.

3. The printed matter according to claim 1 or 2, The printed matter is characterized in that the secret information image is made of an image forming material that absorbs infrared rays.

4. The printed matter according to claim 2, The secret information image is a printed matter characterized in that it is made of a transparent image forming material that reacts to special light.

5. The printed matter according to any one of claims 1 to 4, the information image has a marker image indicating the position of the secret information image, The printed matter is characterized in that the mark image is in the shape of an arrow pointing to the position of the secret information image.

6. The printed matter according to any one of claims 1 to 4, the information image has a marker image indicating the position of the secret information image, The printed matter is characterized in that the target image has a shape that tapers toward the secret information image.

7. The printed matter according to any one of claims 1 to 6, the information image has a marker image indicating the position of the secret information image, The information image is a printed matter characterized in that it has a plurality of target images of the same shape for one secret information image.

8. The printed matter according to claim 7, The printed matter is characterized in that the marking image is printed at a point where a first virtual line passing through the secret information image intersects with the edge of the printing surface, and at a point where a second virtual line passing through the secret information image and perpendicular to the first virtual line intersects with the edge of the printing surface.

9. The printed matter according to any one of claims 1 to 8, the information image has a marker image indicating the position of the secret information image, The printed matter is characterized in that the number of the target images printed on one side of the printing surface is the same as the number of the secret information images.

10. In an image forming apparatus for forming a print by forming an image on a recording medium, An image forming apparatus capable of generating the printed matter according to claim 1 .

Images