Patent Application
20180309899
This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2017-084730, filed Apr. 21, 2017, the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to an image forming apparatus.
A technology which uses a decoloring recording agent to form an image for filling a code image which is a concealed object is proposed as a technology for concealing a code image such as a two-dimensional barcode. However, when the code image is concealed with such a technology, a concealed part is unnatural. Thus, people can easily find that any secret image exists at that position. In this case, the degree of confidentiality is reduced in some cases.
In accordance with an embodiment, an image forming apparatus comprises a printer section and a controller. The printer section forms an image using a decoloring recording agent which is a decolorable recording agent. The controller controls the printer section to form a concealing code image for concealing a secret code image indicating secret information which is a concealed object on a sheet. The controller controls the printer section to form the concealing code image in an area containing at least a part of the secret code image with the decoloring recording agent in such a manner that the secret code image formed on the sheet cannot be decoded.
Hereinafter, an image forming apparatus of an embodiment is described in detail with reference to the accompanying drawings.
The image forming apparatus 1 of the embodiment is an MFP (Multi-Function Peripheral). The image forming apparatus 1 executes an image forming processing. The image forming processing is a processing of forming an image on a sheet. The sheet is, for example, a paper or a label paper. The image forming processing may be executed using a decolorable recording agent. The decoloring in the present embodiment means making an image formed with a color (including not only a chromatic color but also an achromatic color such as white and black) different from a color of a ground of the sheet visually invisible. The decoloring may be performed through heating of the recording agent. For example, the recording agent, such as a toner, may be heated to a temperature greater than a threshold temperature to achieve decoloring. The decoloring may be executed by a method other than decoloring by heating.
The image forming apparatus 1 includes an image reading section 10, a control panel 20, a printer section 30, a sheet housing section 80 and a controller 100. The printer section 30 fixes a visible image formed by using a recording agent (for example, a toner) on a sheet. In the following description, an apparatus for fixing a visible image formed using toner (a specific example of the recording agent) is described as an example.
The image reading section 10 reads image information which is a reading object as intensity of light. The image reading section 10 records the read image information. The recorded image information is output to the controller 100.
The control panel 20 includes a display section and an operation section. The display section is a liquid crystal display or an organic EL (Electro Luminescence) display. The display section displays various information relating to the image forming apparatus 1. The operation section includes an input device such as a plurality of buttons. The operation section receives an operation by the user. The operation section outputs a signal corresponding to the operation executed by the user to the controller 100. The control panel 20 may be constituted using a touch panel formed by the display section and the operation section integrally.
The printer section 30 executes the image forming processing. In the image forming processing, the printer section 30 forms an image on the sheet based on image information generated by the image reading section 10, image information received via a communication path, or image information generated by the controller 100. The printer section 30 in the present embodiment uses a decolorable toner (hereinafter referred to as a “decoloring toner”) and a toner that is not decolorable (hereinafter, referred to as a “normal toner”). The decoloring toner is a specific example of the decoloring recording agent. The normal toner is, for example, a non-decoloring recording agent.
The normal toner includes, for example, a yellow (Y) toner, a magenta (M) toner, a cyan (C) toner, and a black (K) toner. The decoloring toner is a colored toner like the normal toner, and is, for example, black or blue. The decoloring toner is decolorized at a temperature higher than a temperature at which the decoloring toner is fixed on the sheet. Under the control of the controller 100, the printer section 30 executes an image forming processing using the decoloring toner or an image forming processing using the normal toner. In the following description, an image forming processing with the decoloring toner is described as a decoloring printing, and an image forming processing with the normal toner is described as a normal printing.
The sheet housing section 80 includes a plurality of sheet feed cassettes 80A, 80B and 80C. Each of the sheet feed cassettes 80A, 80B and 80C stores a sheet of a predetermined size and type. The sheet feed cassettes 80A, 80B and 80C have pickup rollers 81A, 81B and 81C, respectively. Each of the pickup rollers 81A, 81B and 81C picks up the sheets one by one from each of the sheet feed cassettes 80A, 80B and 80C. The pickup rollers 81A, 81B, and 81C supply the picked sheets to a conveyance section 50.
The conveyance section 50 conveys the sheet picked up from the sheet housing section 80. The conveyance section 50 includes a sheet feed roller 52A, a sheet feed roller 52B, a sheet feed roller 52C, a conveyance roller 53, and a resist roller 54. The sheet feed rollers 52A, 52B and 52C convey the sheet supplied by the pickup rollers 81A, 81B and 81C to the resist roller 54. The resist roller 54 conveys the sheet to a transfer section 55 side according to a timing at which the transfer section 55 of the printer section 30 described later transfers a toner image onto the surface of the sheet. The resist roller 54 conveys the sheet to the transfer section 55 side after aligning a front end of the sheet sent by the conveyance roller 53 at a nip N.
The controller 100 controls the operation of the image forming apparatus 1. The detailed description of the controller 100 is described later.
Next, the detailed constitution of the printer section 30 is described. The printer section 30 includes a developing section 31, an exposure section 38, an intermediate transfer belt 39, the transfer section 55, an inversion unit 60 and a fixing section 70. The developing section 31 has predetermined categories of toner. In the following description, a developing section corresponding to yellow (Y) toner is described as a developing section 31Y, a developing section corresponding to magenta (M) toner is described as a developing section 31M, a developing section corresponding to cyan (C) toner is described as a developing section 31C, a developing section corresponding to the black (K) toner is described as a developing section 31K, and a developing section corresponding to the decoloring toner is described as a developing section 31D.
Each developing section 31 (31Y, 31M, 31C, 31K or 31D) supplies a developer in a developer housing section to a photoconductive drum. The developer housing section houses the developer. The developer is a mixture of a carrier composed of magnetic fine particles and each toner. If the developer is stirred, the toner is triboelectrically charged. Thus, the toner adheres to a surface of the carrier by electrostatic force. In the developer housing section, a first mixer, a second mixer, a developing roller, and a temperature and humidity sensor are arranged. The first mixer and the second mixer stir the developer. The first mixer and the second mixer convey the developer. The second mixer is arranged below a developing roller.
The second mixer supplies the developer housed in the developer housing section to the surface of the developing roller. The temperature and humidity sensor detects temperature and humidity of the inner side of the developer housing section as a state of the printer section 30.
The developing roller rotates counterclockwise by the driving of a developing motor. The developing roller is composed of a magnetic material (magnet) in which negative electrodes and positive electrodes are arranged alternately in a circumferential shape. The developer supplied by the second mixer brushes up on the surface of the developing roller according to a magnetic field distribution of the developing roller. As the developing roller rotates, the napped developer contacts the surface of the photoconductive drum in a sweeping manner. The magnetic field distribution of the developing roller is switchable. The developing section 31 switches the magnetic field distribution of the developing roller to execute napping and ear-breaking of the developer. The developing roller is connected to a voltage applying circuit. Under the control of the controller 100, the voltage applying circuit applies a voltage as a developing bias to the developing roller. The voltage applied to the developing roller is, for example, a negative DC voltage.
The photoconductive drum has a photoconductive layer on a surface thereof. The photoconductive drum rotates clockwise by the driving of the developing motor. Around the photoconductive drum, the developing section 31, a charging section, a discharging section, a cleaning unit and a transfer roller are arranged.
The charging section uniformly charges the surface (photoconductive layer) of the photoconductive drum. For example, the charging section charges the surface (photoconductive layer) of the photoconductive drum to negative polarity. As a result, a toner image is formed on the surface (photoconductive layer) of the photoconductive drum according to an electrostatic latent image.
For example, the developing section 31Y develops the electrostatic latent image on the surface (photoconductive layer) of the photoconductive drum with the yellow (Y) toner. The developing section 31M develops the electrostatic latent image on the surface of the photoconductive drum with the magenta (M) toner. The developing section 31C develops the electrostatic latent image on the surface of the photoconductive drum with the cyan (C) toner. The developing section 31K develops the electrostatic latent image on the surface of the photoconductive drum with the black (K) toner. The developing section 31D develops the electrostatic latent image on the surface of the photoconductive drum with the decoloring toner.
The cleaning unit scrapes off the toner that is not transferred on the surface of the photoconductive drum to remove it. The cleaning unit removes the toner on the surface of the photoconductive drum after the toner image is transferred from the photoconductive drum onto the intermediate transfer belt 39. The toner removed by the cleaning unit is collected in a waste toner tank to be discarded.
The discharging section faces the photoconductive drum across the cleaning unit. The discharging section illuminates the surface of the photoconductive drum with the light. As a result, the heterogeneous charge on the photoconductive layer becomes uniform. In other words, the charge of the photoconductive layer is removed.
The transfer roller faces the photoconductive drum across the intermediate transfer belt 39. The transfer roller abuts against the surface of the photoconductive drum across the intermediate transfer belt 39. The transfer roller transfers (primarily transfers) the toner image on the surface of the photoconductive drum onto the intermediate transfer belt 39.
The exposure section 38 is arranged at a position facing the photoconductive drum of each of the developing sections 31Y, 31M, 31C, 31K and 31D. The exposure section 38 irradiates the surface of the photoconductive drum of each of the developing sections 31Y, 31M, 31C, 31K and 31D with the laser light. The exposure section 38 is controlled to emit the light based on the image data under the control of the controller 100. The exposure section 38 emits the laser light based on the image data. In this way, the negative charge on the surface of the photoconductive drum of each of the developing sections 31Y, 31M, 31C, 31K and 31D is eliminated. As a result, a static electricity pattern is formed at a position irradiated with the laser light on the surface of the photoconductive drum. By irradiation of the laser light by the exposure section 38, the electrostatic latent image is formed on the surface of the photoconductive drum. In the exposure section 38, an LED (Light Emitting Diode) light may be used instead of the laser light.
The inversion unit 60 inverts the sheet discharged from the fixing section 70 by switchback. The inversion unit 60 conveys the inverted sheet to the front of the resist roller 54 again. Therefore, in the sheet conveyed by the inversion unit 60, a surface opposite to the surface subjected to a fixing processing faces the intermediate transfer belt 39. In the sheet which passes twice through the inversion unit 60, a surface same as the surface subjected to the fixing processing faces the intermediate transfer belt 39.
The fixing section 70 applies heat and pressure to the sheet. The fixing section 70 fixes the toner image transferred onto the sheet on the sheet by the heat and pressure.
The description of the printer section 30 is omitted as it is the same as that described above.
The roller driving section 90 is a driving device such as a motor. The roller driving section 90 rotates rollers provided in the conveyance section 50 and the inversion unit 60 by generating a driving force if receiving the supply of electric power. Through the driving by the roller driving section 90, the sheet is conveyed in the conveyance section 50 and the sheet is switched back by the inversion unit 60.
The controller 100 is constituted by a CPU (Central Processing Unit) and a memory. The CPU executes a program stored in the memory, and in this way, the controller 100 functions as a secret code image acquisition section 101, a concealing code image acquisition section 102, an image correction section 103 and an image forming controller 104.
The secret code image acquisition section 101 acquires a secret code image. The secret code image indicates secret information which is a concealed object. The code image is acquired by encoding target information according to a predetermined coding method. The code image includes, for example, a barcode image or an image of a QR code (registered trademark). The code image is represented as an aggregate of predetermined unit images.
Retuning to
The concealing code image acquisition section 102 acquires the concealing code image. The concealing code image is used for concealing the secret code image which is a concealed object. The concealing code image is formed at a position to cover a part or all of the secret code image formed on the sheet. By forming an image in this manner, the secret code image cannot be decoded correctly.
The concealing code image acquisition section 102 may acquire the concealing code image through any processing. For example, the concealing code image acquisition section 102 may acquire image data of the concealing code image read by the image reading section 10. In this case, the image reading section 10 reads the concealing code image previously formed on the sheet to generate the image data. For example, the concealing code image acquisition section 102 may acquire the concealing code image received from another device via the communication section 300. For example, the concealing code image acquisition section 102 may acquire the concealing code image recorded in an external memory connected to the external memory interface 400. The concealing code image acquisition section 102 may acquire the concealing code image by reading the concealing code image previously stored in the concealing code image storage section 200. The concealing code image acquisition section 102 may acquire the concealing code image by encoding concealing information before being encoded. The concealing information is indicated by the concealing code image. The concealing information is used to conceal the secret information, and the concealing information need not be concealed. The concealing information may be received from another device via the communication section 300 or maybe acquired from the external memory via the external memory interface 400.
The image correction section 103 corrects either or both of the secret code image and the concealing code image. For example, if the sizes of the unit images are different between the secret code image and the concealing code image, the image correction section 103 may correct either or both of the secret code image and the concealing code image. In this case, the image correction section 103 executes enlargement or reduction processing so that the sizes of both unit images coincide.
According to an error correction capability of the secret code image, the image correction section 103 may correct the concealing code image so as to have an amount of the dark color parts at which the secret code image cannot be decoded with respect to the light color part of the secret code image. At this time, the correction may be executed by adding the dark color part to the concealing code image before correction within the error correction capability of the concealing code image before correction. By executing such correction, it is possible to conceal the secret code image in such a manner that the secret code image cannot be decoded while realizing decoding of the concealing code image after correction.
The image forming controller 104 controls the printer section 30 to execute the image forming processing on the sheet. If the concealing code image is formed on a sheet on which the secret code image is already formed, the image forming controller 104 controls the printer section 30 to form the concealing code image with the decoloring toner. If the image forming controller 104 forms an image on a sheet on which the secret code image is not formed, first, the image forming controller 104 controls the printer section 30 to form the secret code image with the non-decoloring toner (for example, black toner). Then, the image forming controller 104 controls the roller driving section 90 to convey the sheet in such a manner that the sheet surface on which the secret code image is formed becomes a printing surface. For example, the image forming controller 104 may control the roller driving section 90 so that the sheet passes twice through the inversion unit 60. Then, the image forming controller 104 forms the concealing code image on the sheet surface on which the secret code image is formed. The image forming controller 104 discharges the sheet on which the concealing code image is formed from a discharge section to the outside of the image forming apparatus 1.
The concealing code image storage section 200 is constituted using a storage device such as a magnetic hard disk device or a semiconductor storage device. The concealing code image storage section 200 stores the concealing code image. The concealing code image stored in the concealing code image storage section 200 maybe acquired by the concealing code image acquisition section 102 and formed on the sheet.
The communication section 300 is a communication interface. The communication section 300 executes data communication with another device via a wireless communication path or a priority communication path. For example, the communication section 300 may receive data of the secret code image and data of the secret information from other devices. For example, the communication section 300 may receive data of the concealing code image and data of the concealing information from another apparatus.
The external memory interface 400 is an interface for executing data communication with the external memory. The external memory interface 400 may be constituted as a USB (Universal Serial Bus) port, for example. The external memory interface 400 may be constituted to receive data from external memory, for example, by non-contact communication.
In the example in
After the processing in Act S104 or if the correction condition is not satisfied in Act S103 (NO in Act S103), the image forming controller 104 executes the image forming processing. More specifically, the image forming controller 104 first forms the secret code image on the sheet with the non-decoloring toner (Act S105). The image forming controller 104 then controls the roller driving section 90 to drive the rollers in the inversion unit 60. By the driving, the sheet is conveyed in such a manner that the same surface as the surface subjected to the fixing processing faces the intermediate transfer belt 39 (Act S106). The image forming controller 104 forms the concealing code image at a position where at least a part of the secret code image formed in Act S105 is covered (Act S107). Then, the image forming controller 104 discharges the sheet from the discharge section (Act S108).
In the image forming apparatus 1 arranged in this manner, the degree of confidentiality of the code image can be improved. Hereinafter, such an effect is described in detail. In the image forming apparatus 1, the concealing code image formed to cover the secret code image is formed so that the predetermined information can be acquired by decoding. Therefore, the secret code image can be concealed naturally rather than in an unnatural manner. If a painted rectangle is formed to just cover the secret code image, the existence of the rectangle often becomes unnatural. Those (hereinafter, referred to as “user”) who touch the sheet on which the concealing code image is formed cannot acquire the secret code image in that state, but there is a possibility of easily recognizing that some kind of information is hidden there. On the other hand, in the above image forming apparatus 1, since the concealing code image that can be decoded is formed, it is difficult for the user to recognize that the secret code image is further formed under it. Therefore, it is possible to improve the degree of confidentiality of the code image (secret code image).
In the image forming apparatus 1, the concealing code image is formed so that the secret code image cannot be decoded. Therefore, the secret information is not acquired even if the user attempts a decoding processing using the code image at the position where the secret code image is formed. Therefore, it is possible to improve the degree of confidentiality of the code image (secret code image).
In the image forming apparatus 1, the sizes of the unit images coincide between the secret code image and the concealing code image. Therefore, it is difficult to determine that the secret code image is hidden behind the concealing code image. Therefore, it is possible to improve the degree of confidentiality of the code image (secret code image).
In the image forming apparatus 1, the processing corresponding to Act S106 of the flowchart may be realized in any way. As described above, the processing may be realized by enabling the sheet to pass through the inversion unit 60 twice or may be realized by other means.
The processing in Act S105 and S107 of the flowchart may be executed at once if the image formation using the decoloring toner and the non-decoloring toner can be executed at once in the image forming apparatus 1. The processing in Act S106 becomes unnecessary.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the invention. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-084730 | Apr 2017 | JP | national |
