Image reading device and image forming apparatus

Abstract

To provide an image reading device that has high accuracy in authenticity determination.SOLUTION: An image reading device according to an aspect of the present invention has: an illumination unit; a first reading unit that outputs a first read image obtained by reading an object illuminated by the illumination unit at a first reading magnification; a second reading unit that outputs a second read image obtained by reading the object illuminated by the illumination unit at a second reading magnification; and a determination unit that outputs authenticity information on the object determined based on the second read image. The second reading magnification is higher than the first reading magnification.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an image reading apparatus and an image forming apparatus.

Background Art

[0002] In recent years, with the improvement in the performance of image formation by copiers and printers, there has been a concern that objects such as banknotes, securities, passports, title deeds, household registers, resident cards, various certificates, insurance certificates, or confidential documents may be copied, and there is a demand for an apparatus that determines the authenticity of the object.

[0003] As such an apparatus, there is disclosed an image reading apparatus that acquires reference data representing the characteristics of a genuine individual and obtains collation data representing the characteristics of an object individual with respect to an individual having unique readable characteristics with randomness distributed along the surface, and performs authenticity determination based on the reference data and the collation data (see, for example, Patent Document 1).

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the apparatus of Patent Document 1, since the reference data and the collation data are acquired based on the color and reflectance of the object, there is a concern that the authenticity determination accuracy may be reduced.

[0005] An object of the present invention is to provide an image reading apparatus with high authenticity determination accuracy.

Means for Solving the Problems

[0006] An image reading apparatus according to an aspect of the present invention includes An image reading device that reads a printed image formed on the surface of an object, an illumination unit, including a first photoelectric conversion element, a first reading unit that outputs a first read image read at a first reading magnification of the printed image the by the first photoelectric conversion element illuminated by the illumination unit, and and including a second photoelectric conversion element, a second reading unit that reads the the printed image at a second reading magnification of by the second photoelectric conversion element illuminated by the illumination unit andA second reading unit that outputs the read second reading image, and a determination unit that outputs authenticity information of the object determined based on the second reading image, wherein the second reading magnification is higher than the first reading magnification wherein the first reading unit includes a first mirror unit that reflects the reflected light of the light illuminated by the illumination unit by the object and moves at a constant speed in a predetermined direction along the surface of the object, and a second mirror unit that further reflects the reflected light by the first mirror unit and moves in the predetermined direction in conjunction with the movement of the first mirror unit at a speed that is half of the movement speed of the first mirror unit, and a lens that transmits the reflected light reflected by the second mirror unit. When the first mirror unit and the second mirror unit move in conjunction in the predetermined direction, the entire printed image is read. The second photoelectric conversion element is provided on the first mirror unit, and the second reading unit reads the entire printed image as the second photoelectric conversion element moves in the predetermined direction as the first mirror unit moves. , an image reading device.

Effect of the Invention

[0007] According to the present invention, it is possible to provide an image reading device with high authenticity determination accuracy.

Brief Description of the Drawings

[0008]

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Mode for Carrying Out the Invention

[0009] Hereinafter, modes for carrying out the present invention will be described in detail with reference to the drawings. In each drawing, the same reference numerals are given to the same components, and redundant descriptions will be omitted as appropriate.

[0010] The image reading apparatus according to the embodiment includes an illumination unit and a first reading unit that outputs a first read image obtained by reading an object illuminated by the illumination unit at a first reading magnification. This image reading apparatus is, for example, a scanner or the like mounted on an image forming apparatus such as a multi-function peripheral (MFP). The object is, for example, a printed matter in which an image is formed on a recording medium such as paper by an electrophotographic method or an inkjet method.

[0011] When an image formed on paper by an electrophotographic method or an inkjet method is enlarged in a partial region on the paper, it includes a density distribution corresponding to uneven adhesion of toner or ink, bleeding or scattering (so-called chipping) of toner or ink at the ends of patterns such as characters, etc.

[0012] FIG. 1 and FIG. 2 are diagrams for explaining the density distribution in such a minute area. FIG. 1 is a diagram showing an example of a read image of a printed matter in which a character image is formed on a sheet P by an electrophotographic image forming apparatus. As shown in FIG. 1, the read image 110 includes a character image of "CONFIDENTIAL" formed on the sheet P. FIG. 2 is a diagram showing an enlarged image 120 obtained by enlarging a partial area 111 which is a part of the character image "CONFIDENTIAL" in the read image 110 of FIG. 1. In the enlarged image 120, for example, a density distribution due to uneven toner adhesion occurs in the minute area 121. Also, in the minute areas 122a and 122b, a density distribution corresponding to black dot-like dust where toner has scattered occurs. Such a density distribution in the minute area of the read image 110 is non-reproducible and becomes unique information different for each printed matter.

[0013] In the present embodiment, the authenticity of an object is determined by utilizing the density distribution in the minute area of an object such as a printed matter. For example, as individual identification information indicating that it is a read image 110 of an original printed matter, an enlarged image 120 as shown in FIG. 2 is registered in a registration unit such as a database. Then, when performing the authenticity determination, in a counterfeit printed matter, a minute area at substantially the same position as the read image 110 is read, and an enlarged image 130 as shown in FIG. 3 is obtained. In the enlarged image 130, black dot-like dust where toner has scattered does not occur in the minute areas 131 and 132 as in the enlarged image 120. Based on this difference, it can be determined that the printed matter including the minute area corresponding to the enlarged image 130 is a counterfeit.

[0014] However, if the first reading magnification of the first reading unit used as a scanner is increased to such an extent that the density distribution in the minute area can be read, the reading range becomes narrow according to the first reading magnification, thus impairing the copying function which is the main function of the image reading apparatus.

[0015] Therefore, the image reading apparatus according to the embodiment includes a second reading unit that outputs a second read image obtained by reading a printed matter illuminated by an illumination unit at a second reading magnification, and a determination unit that outputs authenticity information of an object determined based on the second read image, and the second reading magnification is higher than the first reading magnification.

[0016] The image reading device according to the embodiment performs authenticity determination using the density distribution of a minute region in a second read image read by a second reading unit having a higher reading magnification than the first reading unit, thereby enabling high-precision authenticity determination without impairing the main function of the image reading device, which is a copying function.

[0017] In the following embodiments, an image forming apparatus which is a multi-function peripheral (MFP) will be described as an example. The image forming apparatus according to the embodiment forms an image on a sheet (an example of a recording medium) by an electrophotographic method, and includes an image reading apparatus that reads a printed matter as an example of an object.

[0018] <Configuration example of image forming apparatus 1> (Hardware configuration example of image forming apparatus 1) FIG. 4 is a block diagram showing the hardware configuration of the image forming apparatus 1 according to the present embodiment. The image forming apparatus 1 has an engine that executes image formation in addition to a configuration similar to that of a general information processing terminal such as a server or a personal computer (PC).

[0019] The image forming apparatus 1 includes a central processing unit (CPU) 10, a random access memory (RAM) 11, a read only memory (ROM) 12, an engine 13, a hard disk drive (HDD) 14, and an interface (I / F) 15. These are electrically connected to each other via a bus 18. Further, the I / F 15 is connected to a liquid crystal display (LCD) 16 and an input operation unit 17.

[0020] The CPU 10 is an arithmetic means that controls the operation of the entire image forming apparatus 1. The RAM 11 is a volatile storage medium that enables high-speed reading and writing of information. The CPU 10 uses the RAM 11 as a work area when processing information. The ROM 12 is a read-only non-volatile storage medium that stores programs such as firmware. The engine 13 is a mechanism that actually executes image formation in the image forming apparatus 1. The components other than the engine 13 are collectively referred to as the information processing apparatus 2.

[0021] The HDD 14 is a non-volatile storage medium that enables reading and writing of information, and stores an OS (Operating System), various control programs, application programs, etc. The I / F 15 is an interface that connects and controls the bus 18 and various hardware and networks. The display device 16 is a visual user interface for the user to check the state of the image forming apparatus 1. The input operation unit 17 is a user interface such as a keyboard or a mouse for the user to input information into the image forming apparatus 1.

[0022] In the above hardware configuration, the image forming apparatus 1 reads the program stored in the recording medium such as the ROM 12, the HDD 14, or the optical disk into the RAM 11 and operates according to the control of the CPU 10, thereby constituting a software control unit. The image forming apparatus 1 constitutes a functional block that realizes the functions of the image forming apparatus 1 by combining the software control unit configured in this way with the hardware.

[0023] (Functional configuration example of the image forming apparatus 1) FIG. 5 is a block diagram showing an example of the functional configuration of the image forming apparatus 1. The image forming apparatus 1 includes a controller 20, an image reading device 100, a display panel 24, a paper feed table 25, a print engine 26, a paper discharge tray 27, and a network I / F 28. The image reading device 100 includes an ADF 21, a scanner unit 22, and a paper discharge tray 23.

[0024] The controller 20 includes a main control unit 30, an engine control unit 31, an input / output control unit 32, an image processing unit 33, an operation display control unit 34, and a determination unit 35. The image forming apparatus 1 is configured as a multifunction device having a scanner unit 22 and a print engine 26. In FIG. 5, electrical connections are indicated by solid arrows, and the paper flow is indicated by dashed arrows.

[0025] The display panel 24 is an output interface that visually displays the state of the image forming apparatus 1. The display panel 24 is also an input interface (input operation unit) when the user directly operates the image forming apparatus 1 or inputs information to the image forming apparatus 1 as a touch panel.

[0026] The network I / F 28 is an interface such as Ethernet (registered trademark) or USB (Universal Serial Bus) for the image forming apparatus 1 to communicate with other devices via a network.

[0027] The controller 20 is composed of a combination of software and hardware. Specifically, control programs such as firmware stored in non-volatile recording media such as the ROM 12, non-volatile memory, the HDD 14, and optical disks are loaded into a volatile memory such as the RAM 11, and the controller 20 is composed of a software control unit configured according to the control of the CPU 10 and hardware such as an integrated circuit. The controller 20 functions as a control unit that controls the entire image forming apparatus 1.

[0028] The main control unit 30 is responsible for controlling each part included in the controller 20 and gives commands to each part of the controller 20. The engine control unit 31 serves as a driving means for controlling or driving the print engine 26, the scanner unit 22, and the like.

[0029] The input / output control unit 32 inputs signals and commands input via the network I / F 28 to the main control unit 30. Also, the main control unit 30 controls the input / output control unit 32 and accesses other devices via the network I / F 28.

[0030] The image processing unit 33 is an electric circuit that generates drawing information based on the print information included in the input print job according to the control of the main control unit 30. This drawing information is information for the print engine 26 to draw the image to be formed in the image forming operation. Also, the print information included in the print job is image information converted into a format recognizable by the image forming apparatus 1 by a printer driver installed in an information processing apparatus such as a PC. The operation display control unit 34 displays information on the display panel 24 or notifies the main control unit 30 of the information input via the display panel 24.

[0031] When the image forming apparatus 1 operates as a printer, first, the input / output control unit 32 receives a print job via the network I / F 28. The input / output control unit 32 transfers the received print job to the main control unit 30. When the main control unit 30 receives the print job, it controls the image processing unit 33 to generate drawing information based on the print information included in the print job.

[0032] When the drawing information is generated by the image processing unit 33, the engine control unit 31 executes image formation on the paper conveyed from the paper feed table 25 based on the generated drawing information. That is, the print engine 26 functions as an image forming unit. The paper on which image formation has been performed by the print engine 26 is discharged to the discharge tray 27.

[0033] When the image forming apparatus 1 operates as a scanner, in response to an operation of the display panel 24 by an operator of the image forming apparatus 1 (hereinafter simply referred to as the operator) or a scan execution instruction input from an external PC or the like via the network I / F 28, the operation display control unit 34 or the input / output control unit 32 transfers a scan execution signal to the main control unit 30. Based on the received scan execution signal, the main control unit 30 controls the engine control unit 31.

[0034] The engine control unit 31 drives the ADF 21 and conveys the printed matter set on the ADF 21 to the scanner unit 22. Further, the engine control unit 31 drives the scanner unit 22 to image the printed matter conveyed from the ADF 21. When no printed matter is set on the ADF 21 and a printed matter is directly set on the scanner unit 22, the scanner unit 22 images the set printed matter in accordance with the control of the engine control unit 31. That is, the scanner unit 22 operates as an imaging unit for the printed matter.

[0035] In the imaging operation, the imaging element included in the scanner unit 22 images the printed matter while being moved in a predetermined direction, and the scanner unit 22 generates imaging information. The engine control unit 31 transfers the imaging information generated by the scanner unit 22 to the image processing unit 33. The image processing unit 33 generates a read image based on the imaging information received from the engine control unit 31 in accordance with the control of the main control unit 30.

[0036] The read image generated by the image processing unit 33 is stored as it is in the HDD 14 or the like in response to an instruction from the operator, or is transmitted to an external device via the input / output control unit 32 and the network I / F 28.

[0037] When the image forming apparatus 1 operates as a copier, based on the imaging information received by the engine control unit 31 from the scanner unit 22 or the read image generated by the image processing unit 33, the image processing unit 33 generates drawing information. The engine control unit 31 drives the print engine 26 in the same manner as in the case of the printer operation based on this drawing information.

[0038] Based on the read image of the printed matter generated by the scanner unit 22, the determination unit 35 executes the authenticity determination process of the printed matter. The function of this determination unit 35 will be described in detail with reference to FIG. 10 separately.

[0039] (Example of the overall configuration of the image forming apparatus 1) FIG. 6 is a diagram showing an example of the schematic configuration of the image forming apparatus 1. As shown in FIG. 6, the image forming apparatus 1 includes an image reading device 100, an image forming unit 300, and a paper feeding unit 400.

[0040] The paper feeding unit 400 includes paper feeding cassettes 421 and 422 that store papers of different sizes, and paper feeding means 423 including various rollers that convey the papers stored in the paper feeding cassettes 421 and 422 to the image forming position of the image forming unit 300.

[0041] The image forming unit 300 includes an exposure device 331, a photosensitive drum 332, a developing device 333, a transfer belt 334, and a fixing device 335. Based on the image data of the printed matter read by the image reading device 100 or the image data input from an external PC or the like via the network I / F 28, the image forming unit 300 exposes the photosensitive drum 332 by the exposure device 331 to form a latent image on the photosensitive drum 332. The image forming unit 300 supplies and develops different color toners to the photosensitive drum 332 by the developing device 333. After the image forming unit 300 transfers the image developed on the photosensitive drum 332 to the paper supplied from the paper feeding unit 400 by the transfer belt 334, the image forming unit 300 melts the toner constituting the toner image transferred to the paper by the fixing device 335 to fix the color image on the paper.

[0042] <Example of the configuration of the scanner unit 22> (Example of the overall configuration of the scanner unit 22) FIG. 7 is a diagram showing an example of the configuration of the scanner unit 22 included in the image forming apparatus 1. The scanner unit 22 is, for example, of a differential mirror drive type and is an image reading apparatus of an optical sensor integrated drive type. The dashed-dotted line shown in FIG. 7 represents the light reflected by the printed matter.

[0043] As shown in FIG. 7, the scanner unit 22 includes a first mirror unit 204, a second mirror unit 210, a lens 216, and a first sensor board 215. The first mirror unit 204 includes a light source 200, a first mirror 202 supported at both ends, and a second sensor board 223 on which a second photoelectric conversion element 222 such as a CCD (Charge Coupled Device) is mounted. The second mirror unit 210 includes a second mirror 206 and a third mirror 208 supported at both ends. Each mirror such as the first mirror 202 is a reflecting member that further reflects the light reflected by the printed matter from the illumination light by the light source 200.

[0044] The light source 200 includes a light emitting portion such as an LED (Light Emitting Diode), and is an example of an illumination portion that illuminates the printed matter with white light. However, the color of the light irradiated by the light source 200 is not limited to white, and may be monochromatic light of any color. The lens 216 forms an image of the light reflected by the printed matter from the illumination light by the light source 200 on the first photoelectric conversion element 214 such as a CCD. The first photoelectric conversion element 214 is mounted on the first sensor board 215 together with other hardware, for example. The first photoelectric conversion element 214 is, for example, a CCD.

[0045] The light source 200 illuminates a printed matter placed on the document reading glass 212 by irradiating light through the document reading glass 212. The reflected light from the printed matter is reflected by the first mirror 202, the second mirror 206, and the third mirror 208 in this order after passing through the document reading glass 212, and is guided to the lens 216. Thereafter, the reflected light is substantially imaged on the first photoelectric conversion element 214 by the lens 216. The image of the printed matter formed is read by the first photoelectric conversion element 214 performing photoelectric conversion to obtain an analog image signal. The white reference plate 218 is a white member that reflects the light irradiated by the light source 200 in order to correct the white level.

[0046] In the scanner unit 22, the first mirror 202, the second mirror unit 210, the lens 216, and the first photoelectric conversion element 214 constitute the first reading unit 3. The first reading unit 3 can output, as a first read image, imaging information obtained by reading a printed matter illuminated by the light source 200 at a first reading magnification. The ratio b / a, which is the distance from the printed matter to the principal plane of the lens 216 via the first mirror 202, the second mirror 206, and the third mirror 208 (object distance a) to the distance from the principal plane of the lens 216 to the imaging surface of the first photoelectric conversion element 214 (imaging distance b), corresponds to the first reading magnification. Since the imaging distance b is shorter than the object distance a, the first reading magnification is less than 1, and the first reading unit 3 outputs a first read image of the printed matter reduced by a reduction optical system.

[0047] The second photoelectric conversion element 222 is an example of a second reading unit that outputs, as a second read image, imaging information obtained by reading a printed matter illuminated by the light source 200 at a second reading magnification. The second photoelectric conversion element 222 has a plurality of pixels arranged along the main scanning direction 240 and can read the entire width of the printed matter along the main scanning direction 240. However, it is not necessarily required to be able to read the entire width of the printed matter, and the second photoelectric conversion element 222 may read a part of the printed matter along the main scanning direction 240.

[0048] In this embodiment, since no lens is provided between the printed matter and the second photoelectric conversion element 222 and the printed matter and the second photoelectric conversion element 222 are close to each other, the second photoelectric conversion element 222 can read the printed matter at a same magnification. That is, the second reading magnification is the same magnification (1×), which is larger than the first reading magnification.

[0049] For example, the first reading unit 3 reads the printed matter at a resolution of 600 [dpi: dots per inch] or 1200 [dpi]. The dot pitch at 600 [dpi] is 42.3 [μm], and the dot pitch at 1200 [dpi] is 21.2 [μm]. By making the second reading magnification higher than the first reading magnification, the second photoelectric conversion element 222 can read the printed matter at a higher resolution than the first reading unit 3. In order to read an image of one toner on the image formed on the printed matter, the resolution by the second photoelectric conversion element 222 is preferably 2400 [dpi] or more and it is preferable that a dot pitch of 10.0 [μm] or less can be resolved. Therefore, it is preferable that the second reading magnification is 2 times or more and 5 times or less of the first reading magnification.

[0050] More specifically, the second photoelectric conversion element 222 is, for example, a CCD that outputs a monochrome second read image in which 1300 pixels having a square lattice shape are arranged along the main scanning direction 240. The second photoelectric conversion element 222 can image, as a minimum area, an area on the printed matter that substantially corresponds to an area of about 4.9 [μm] × 4.9 [μm] per pixel. Therefore, even when the minimum diameter of the toner is about 5 [μm], the second photoelectric conversion element 222 can read an image of one toner in the image formed on the printed matter.

[0051] The area of the effective imaging region in the second photoelectric conversion element 222 is larger than the area of the effective imaging region in the first photoelectric conversion element 214, and the second photoelectric conversion element 222 reads the printed matter with a higher resolution (spatial resolution) than the first reading unit 3. On the other hand, the range on the printed matter that can be imaged by the second photoelectric conversion element 222 is narrower than the range on the printed matter that can be imaged by the first reading unit 3.

[0052] When reading a printed matter, the first mirror unit 204 moves at a constant speed along the sub-scanning direction 250. Also, the second mirror unit 210 is linked to the first mirror unit 204 and moves along the sub-scanning direction 250 at a speed that is approximately half of the moving speed of the first mirror unit 204. In FIG. 4, the first mirror unit 204 and the second mirror unit 210 each indicated by a dashed line represent the first mirror unit 204 and the second mirror unit 210 after moving along the sub-scanning direction 250.

[0053] The first reading unit 3 can read the entire width of the printed matter along the sub-scanning direction 250 while keeping the subject distance a substantially constant by the first mirror unit 204 and the second mirror unit 210 moving in conjunction along the sub-scanning direction 250.

[0054] The second photoelectric conversion element 222 provided in the first mirror unit 204 moves along with the movement of the first mirror unit 204 along the sub-scanning direction 250 and can read the entire width of the printed matter along the sub-scanning direction 250.

[0055] When continuously and automatically reading a sheet-like printed matter, the printed matter is conveyed on the sheet original reading glass 220 by the ADF 21, and the light source 200 irradiates light through the sheet original reading glass 220. The reflected light reflected by the printed matter from the irradiated light passes through the sheet original reading glass 220 and is reflected by the first mirror 202, the second mirror 206, and the third mirror 208 in this order and guided to the lens 216. Thereafter, this reflected light is substantially imaged on the first photoelectric conversion element 214 by the lens 216. At this time, the first mirror unit 204 and the second mirror unit 210 read the image of the conveyed sheet-like printed matter in a fixed state. The reading operation is started by pressing the start key provided in the input operation unit 17.

[0056] Note that the first reading unit 3 may be of a unit type integrating a mirror and a photoelectric conversion element, or may use an equal magnification close contact image sensor (CIS).

[0057] (Example of drive method of scanner unit 22) FIG. 8 is a diagram showing the drive method of the scanner unit 22. The scanner motor 230 is a stepping motor. When the shaft of the scanner motor 230 rotates, a rotational driving force is transmitted to the shaft 234 via the timing belt 232. When the wire pulleys 236a and 236b provided on the shaft 234 rotate, the first mirror unit 204 and the second mirror unit 210 connected to the wires 238a and 238b move. At this time, the second mirror unit 210 moves at half the speed relative to the first mirror unit 204. Note that the drive method of the scanner unit 22 may be a method via a timing belt instead of a wire or the like.

[0058] (Example of electrical configuration of scanner unit 22) FIG. 9 is a block diagram showing an outline of the electrical configuration of the scanner unit 22. The scanner unit 22 executes initialization processes such as a homing operation and adjustment of signal processing characteristics of a read image (black level adjustment and white level adjustment) according to the electrical configuration shown in FIG. 9.

[0059] The CPU (control unit) 10 controls the overall operation of the scanner unit 22 including an imaging sequence by controlling each part constituting the scanner unit 22. Further, the CPU 10 receives a position detection signal necessary for the homing operation from the home position sensor 64. The CPU 10 controls the scanner motor 230 so as to move the first mirror unit 204 when the scanner motor 230 performs driving.

[0060] The motor driver 62 drives a scanner motor 230 that moves the first mirror unit 204 and the second mirror unit 210. The first sensor board 215 has a first photoelectric conversion element 214 and the like mounted thereon, and the first photoelectric conversion element 214 outputs a first read image Im1 to the CPU 10. The second sensor board 223 has a second photoelectric conversion element 222 and the like mounted thereon, and the second photoelectric conversion element 222 outputs a second read image Im2 to the CPU 10.

[0061] The CPU 10 performs digital processing on the first read image Im1 and the second read image Im2. For example, the CPU 10 performs image correction processing such as shading processing, gamma correction processing, magnification processing, or filter processing on the digital data of the first read image Im1 and the second read image Im2. Further, the CPU 10 can detect, by calculation, data of the black level and the white level necessary for obtaining adjustment values for performing clamping and gain correction on the first sensor board 215 and the second sensor board 223 from the input digital image data.

[0062] The home position sensor 64 is, for example, a photointerrupter, and outputs a position detection signal for detecting the position of the first mirror unit 204. The NVRAM (Non-Volatile Random Access Memory) 65 stores data necessary for controlling the initialization process.

[0063] The first read image Im1 read by the first photoelectric conversion element 214 corresponds to, for example, the read image 110 shown in FIG. 1. The image forming apparatus 1 can provide a copy obtained by copying a printed matter by forming an image on the paper P based on the first read image Im1.

[0064] The second read image Im2 read by the second photoelectric conversion element 222 corresponds to, for example, the enlarged image 120 shown in FIG. 2 and the enlarged image 130 shown in FIG. 3, respectively. The image forming apparatus 1 can perform authenticity determination of a printed matter using the second read image Im2.

[0065] In this embodiment, the genuine printed matter is, for example, the one in which an image is formed on the paper P by the image forming apparatus 1. In particular, when performing authenticity determination using an image formed by black toner, the determination accuracy can be further improved.

[0066] Regarding the reproducibility in dot units, there is an extremely low possibility that there exists a paper having exactly the same toner adhesion state for an image formed on a recording medium such as paper by an electrophotographic image forming apparatus. In an electrophotographic image forming apparatus, a latent image is formed on a photoreceptor, and then toner is developed on the photoreceptor by electrostatic force by a developing device. After that, the toner is transferred to a transfer belt and then further transferred to the paper. In a series of processes of development, primary transfer, and secondary transfer, the toner repeats moving to the image carrier a total of three times, and the probability of being in the same state for each dot becomes extremely low.

[0067] Also, although there is a possibility that large stains such as toner stains and dirt adhesion that can be clearly visually confirmed occur compared to the size of one dot, it is difficult for minute stains of less than one dot size to adhere. Therefore, the density distribution of a minute region including dots is suitable as information used for authenticity determination.

[0068] (Functional configuration example of the determination unit 35 according to the first embodiment) Next, FIG. 10 is a diagram showing an example of the functional configuration of the determination unit 35. The determination unit 35 includes a feature amount extraction unit 281, a registration unit 282, a comparison unit 283, and an output unit 284. Among these, each function of the feature amount extraction unit 281 and the comparison unit 283 is realized by the CPU 10 executing a program stored in the ROM 12 or the HDD 14 or the like. Also, the function of the registration unit 282 is realized by the CPU 10 executing a program stored in the ROM 12 or the HDD 14 and controlling the HDD 14 or the like. The function of the output unit 284 is realized by the CPU 10 executing a program stored in the ROM 12 or the HDD 14 and controlling the display device 16 or the communication I / F 15 or the like.

[0069] The determination unit 35 extracts feature amounts from the second read image Im2 of the printed matter read by the second photoelectric conversion element 222 by the feature amount extraction unit 281. When performing the registration process of the feature amount data, the determination unit 35 registers the extracted feature amount data by the registration unit 282, and when performing the authenticity determination process, outputs the extracted feature amount data to the comparison unit 283.

[0070] The feature amount extraction unit 281 quantizes by dividing the input second read image Im2 into meshes of an appropriate size. The number of meshes d is the number of M [pieces] in the vertical direction × N [pieces] in the horizontal direction. Further, the feature amount extraction unit 281 converts the second read image Im2 into a mosaic-like image by representing each mesh by a density value of a predetermined density level q for sampling. After quantization and sampling, the feature amount extraction unit 281 sets the density of the j-th mesh as xj, and represents the second read image Im2 by a vector x = (x1, x2, ··· xd) T where T represents a transposed matrix. The vector expressed in this way corresponds to the feature amount data. Each element of the vector gives the density of the corresponding image region. The second read image Im2 is represented as a point on the feature space represented by the vector. Since different density distributions can be obtained for each printed matter in a minute region, the feature amounts also represent unique features for each printed matter.

[0071] Since the printed image itself contains a random density distribution that cannot be reproduced, the density distribution itself of the read second read image Im2 may be used as the feature amount data. However, when the second read image is quantized and sampled to obtain the feature amounts, the feature amounts for each printed matter become clearer, so that the authenticity determination process can be simplified.

[0072] During the authenticity determination, the comparison unit 283 sequentially reads out the registered feature amount data registered in the registration unit 282 from the registration unit 282, and compares the extracted feature amount data of the second read image Im2 extracted by the feature amount extraction unit 281 with all the registered feature amount data. The comparison unit 283 determines the authenticity of the printed matter according to the similarity between the two.

[0073] The similarity between the extracted feature amount data and the registered feature amount data used for authenticity determination can be calculated from the distance between the two in the feature space. This distance is, for example, the Euclidean distance or the Mahalanobis distance. The closer the calculated distance is, the more similar the two are. The comparison unit 283 compares the extracted feature amount data with all the registered feature amount data, and if the registered feature amount data with a similarity equal to or greater than a predetermined threshold has already been registered in the registration unit 282, it determines that the printed matter is genuine. On the other hand, if the registered feature amount data with a similarity equal to or greater than a predetermined threshold has not been registered in the registration unit 282, it determines that the printed matter is a forgery.

[0074] In this embodiment, a configuration for determining authenticity based on the distance in the feature space between the extracted feature amount data and the registered feature amount data is exemplified, but it is also possible to determine using the angle formed by the vectors. Further, without performing mosaic processing, the similarity can also be evaluated based on the correlation value between images, the cumulative squared error, etc.

[0075] Furthermore, the second read image may be converted into the frequency domain by two-dimensional Fourier transform and the determination may be performed in the frequency space. In this case, the pre-registered second read image and the second read image obtained at the time of authenticity determination are synthesized in the frequency space, and the correlation intensity image is obtained by performing inverse Fourier transform on the synthesis result. The similarity between the two images can be evaluated from the peak value in the correlation intensity image. For example, if the peak value of the amplitude spectrum is equal to or greater than a predetermined amplitude threshold, it can be determined that it is genuine.

[0076] Also, the barycentric positions of the minute points scattered in an island shape in the feature amount data can be calculated, and the similarity can be evaluated based on the distance and position between the barycenters. According to this method, the effect of reducing the amount of data used in the determination process can be obtained.

[0077] The determination unit 35 outputs the determination result by the comparison unit 283 to an external device via the output unit 284. Examples of this external device include the display device 16 of the image forming apparatus 1 and an external PC. For example, the image forming apparatus 1 can notify the operator of the image forming apparatus 1 whether the printed matter is genuine or not by displaying the determination result on the display device 16. Further, the image forming apparatus 1 can store the authenticity information as to whether the printed matter is genuine or not by outputting the determination result to an external PC via the network I / F 28.

[0078] <Example of processing by the image reading apparatus 100 according to the first embodiment> (Example of registration processing) FIG. 11 is a flowchart showing an example of the registration process of feature amount data by the image reading apparatus 100 included in the image forming apparatus 1. The operator of the image forming apparatus 1 places the printed matter to be registered on the document reading glass 212 or inserts the printed matter into the ADF 21 and positions it by abutting against the abutting member. Thereafter, at the timing when the operator inputs a registration start operation via the operation unit of the image forming apparatus 1, the image reading apparatus 100 starts the process of FIG. 11.

[0079] First, in step S211, the image reading apparatus 100 inputs a second read image Im2 obtained by the second photoelectric conversion element 222 reading a minute area at a predetermined position on the printed matter to the feature amount extraction unit 281. The printed matter is positioned by the document reading glass 212 and the abutting member of the ADF 21. Therefore, the image reading apparatus 100 can easily specify the predetermined position of the minute area based on the distance from the end of the printed matter.

[0080] Subsequently, in step S212, the image reading apparatus 100 converts the second read image Im2 into a mosaic-like image by quantizing and sampling the second read image Im2 by the feature amount extraction unit 281.

[0081] Subsequently, in step S213, the image reading apparatus 100 extracts feature amounts from the converted mosaic-like image by the feature amount extraction unit 281.

[0082] Subsequently, in step S214, the image reading device 100 registers the extracted feature amount data by the registration unit 282.

[0083] In this way, the image reading device 100 can register the feature amount data serving as a criterion for authenticity determination in the registration unit 282.

[0084] (Example of authenticity determination process) FIG. 12 is a flowchart showing an example of the authenticity determination process by the image reading device 100 included in the image forming apparatus 1. An operator of the image forming apparatus 1 places a printed matter to be determined for authenticity on the original reading glass 212, or inserts the printed matter into the ADF 21 and positions it by abutting against the abutting member. Thereafter, at the timing when the operator inputs an authenticity determination start operation via the operation unit of the image forming apparatus 1, the image reading device 100 starts the process of FIG. 12.

[0085] Since the processes from step S221 to step S223 are the same as the processes from step S211 to step S213 in FIG. 11, duplicate explanations are omitted here.

[0086] In step S224, the image reading device 100 compares the extracted feature amount data of the second read image Im2 with all the registered feature amount data while sequentially reading out the registered feature amount data from the registration unit 282 by the comparison unit 283, and calculates the similarity between the two.

[0087] Subsequently, in step S225, the image reading device 100 determines by the comparison unit 283 whether there is registered feature amount data having a feature amount similarity equal to or greater than a predetermined similarity threshold with the extracted feature amount data.

[0088] The similarity threshold is preferably set by providing an allowable range in consideration of errors in the registered feature amount data and the extracted feature amount data due to reading errors or quantization and sampling errors, etc. Also, the similarity threshold is appropriately selected according to the requirement of whether to perform strict authenticity determination. Further, when the allowable range varies depending on the type of printed matter, the image reading device 100 may register the similarity threshold in association with the registered feature amount data when registering the feature amount data, and use the similarity threshold read together with the registered feature amount data during authenticity determination to perform the process of step S225.

[0089] In step S225, when it is determined that there is registered feature amount data equal to or greater than the similarity threshold (step S225, Yes), in step S226, the image reading device 100 determines by the comparison unit 283 that the printed matter is genuine. On the other hand, when it is determined that there is no registered feature amount data equal to or greater than the similarity threshold (step S225, No), in step S227, the image reading device 100 determines by the comparison unit 283 that the printed matter is a fake.

[0090] Subsequently, in step S228, the image reading device 100 outputs the determination result to an external device by the output unit 284.

[0091] In this way, the image reading device 100 can perform authenticity determination of the printed matter. Note that during authenticity determination, operation errors by the operator or misalignment of the printed matter may occur. Therefore, in order to suppress these influences, the final determination may be made according to the determination results of multiple times.

[0092] In this embodiment, the process of comparing all the registered feature amount data registered by the registration unit 282 with the extracted feature amount data has been exemplified, but it is not limited thereto. For example, when registering the registered feature amount data, the identification code of the printed matter may be registered in the registration unit 282 in association with the registered feature amount data, and at the time of authenticity determination, the registered feature amount data read based on the identification code may be compared with the extracted feature amount data. In this case, since the comparison process is not performed for all the registered feature amount data, the processing load can be reduced and the processing time can be shortened.

[0093] The program for executing each step of FIGS. 11 and 12 can also be stored in a recording medium, and the program can also be provided by communication means. Examples of the recording medium include digital versatile disks (DVDs), such as "DVD-R, DVD-RW, DVD-RAM, etc." which are standards established by the DVD Forum, "DVD+R, DVD+RW, etc." which are standards established by DVD+RW, compact disks (CDs), such as read-only memory (CD-ROM), CD recordable (CD-R), CD rewritable (CD-RW), etc., magneto-optical disks (MOs), flexible disks (FDs), magnetic tapes, hard disks, read-only memory (ROM), electrically erasable and rewritable read-only memory (EEPROM), flash memory, random access memory (RAM), and the like.

[0094] The above program or a part thereof can be recorded on the above recording medium for storage, distribution, etc. Also, it can be transmitted by communication using, for example, a wired network used in a local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), the Internet, an intranet, an extranet, etc., or a wireless communication network, or a combination thereof, and it can also be carried on a carrier wave for transmission.

[0095] Furthermore, the above program may be a part of another program, or may be recorded on a recording medium together with a separate program. It may also be recorded by being divided among a plurality of recording media.

[0096] <Operation and effect of the image reading device 100 according to the first embodiment> As described above, the image reading device 100 included in the image forming apparatus 1 includes a light source 200 (lighting unit) and a first reading unit 3 that outputs a first read image Im1 obtained by reading a printed matter (object) illuminated by the light source 200 at a first reading magnification. The image reading device 100 also includes a second photoelectric conversion element 222 (second reading unit) that outputs a second read image Im2 obtained by reading the printed matter illuminated by the light source 200 at a second reading magnification, and a determination unit 35 that outputs a determination result (genuine / fake information) of the printed matter determined based on the second read image Im2. The second reading magnification is higher than the first reading magnification.

[0097] By reading the printed matter at a second reading magnification higher than the first reading magnification, it is possible to obtain a density distribution in which a predetermined minute region in the printed matter is enlarged. By performing the genuine / fake determination using the density distribution of this minute region, the amount of information increases compared to the case of performing the genuine / fake determination using, for example, the color or reflectance of the printed matter, so that the accuracy of the genuine / fake determination can be made higher. In other words, it is possible to provide an image reading device 100 with high genuine / fake determination accuracy. The amount of information increases as the number of pixels of the second photoelectric conversion element 222 increases. Since copying of a printed matter such as a document by the image reading device 100 is performed using the first reading unit 3, the image reading device 100 can execute the genuine / fake determination process with high accuracy without impairing the main function, which is the copying function.

[0098] For copying a printed matter, it is preferable to set a first reading magnification so as to be readable at a resolution of 600 [dpi] or 1200 [dpi]. Further, since the diameter of one toner in an electrophotographic method is about 5 [μm] to 10 [μm], in order to read this, it is preferable that the reading resolution of the second photoelectric conversion element 222 is 2400 [dpi] or more. Therefore, in the present embodiment, it is preferable that the second reading magnification is 2 times or more and 5 times or less the first reading magnification. By doing so, since the random distribution of each toner can be detected, more information can be obtained for authenticity determination.

[0099] On the other hand, if the reading magnification is too high, many pixels are used to image one toner, so that the random distribution of each toner cannot be detected and the amount of information for authenticity determination may conversely decrease. By setting the second reading magnification to be 2 times or more and 5 times or less the first reading magnification, such a decrease in the amount of information can be avoided.

[0100] Further, in the present embodiment, it is preferable that the second reading magnification is 1× magnification. By setting it to 1× magnification, the image reading apparatus 100 can set the second reading magnification to be 2 times or more and 5 times or less with respect to the first reading magnification for realizing the reading resolution of 600 [dpi] or 1200 [dpi] in the first reading unit 3. Further, when the second photoelectric conversion element 222 is disposed close to the printed matter, the second reading magnification can be set to 1× magnification without using a lens, which is more preferable from the viewpoint of simplifying the configuration.

[0101] Further, in the present embodiment, the first reading unit 3 has a first mirror unit 204 (variable mechanism) that changes the position to be read by the first reading unit 3 in the printed matter along the sub-scanning direction 250 (predetermined direction). The second photoelectric conversion element 222 is installed in the first mirror unit 204, and the first mirror unit 204 moves the second photoelectric conversion element 222 along the sub-scanning direction 250. As a result, the second photoelectric conversion element 222 having a second reading magnification of 1× magnification can image the entire width of the printed matter along the sub-scanning direction 250.

[0102] Since the second read image Im2 only needs to be able to image a minute area of a part of the printed matter, it is not necessarily required to image the entire width of the printed matter along the sub-scanning direction 250. However, from the perspective of enabling arbitrary selection of particularly characteristic minute areas within the printed matter, it is preferable to be able to image the entire width of the printed matter.

[0103] Also, the second photoelectric conversion element 222 does not necessarily have to be movable and may be configured to be fixed at a predetermined position. For example, in a case where a high-magnification objective lens is used to obtain a high second read magnification, the working distance becomes narrow. Thus, if the second photoelectric conversion element 222 moves, there is a risk that the objective lens may collide with the document reading glass 212 or the like. By fixing the second photoelectric conversion element 222, such a risk can be reduced.

[0104] [Second Embodiment] Next, the image reading apparatus 100a according to the second embodiment will be described. The image reading apparatus 100a is provided in the image forming apparatus 1. Note that the same reference numerals are assigned to the same components as in the first embodiment, and redundant descriptions will be omitted as appropriate.

[0105] FIG. 13 is a block diagram showing an example of the functional configuration of a determination unit 35a included in the image reading apparatus 100a. The determination unit 35a includes a detection unit 285 and a notification unit 286. The function of the detection unit 285 is realized by the CPU 10 executing a program stored in the ROM 12 or the HDD 14 or the like. Also, the function of the notification unit 286 is realized by the CPU 10 executing a program stored in the ROM 12 or the HDD 14 and controlling the display device 16 or the like.

[0106] The detection unit 285 detects the misalignment of the printed matter on the document reading glass 212 or the ADF 21 based on the first read image Im1 read by the first photoelectric conversion element 214. This misalignment includes tilt misalignment where the printed matter is installed at an angle (rotated in the plane) with respect to the document reading glass 212 or the ADF 21, shift misalignment where the printed matter is shifted and installed, and the like. When the detection unit 285 detects a tilt misalignment equal to or greater than a predetermined tilt threshold value, or when it detects a shift misalignment equal to or greater than a predetermined shift threshold value, it outputs the detection result to the notification unit 286.

[0107] The notification unit 286 notifies the misalignment of the printed matter on the document reading glass 212 or the ADF 21 detected by the detection unit 285. For example, when the detection unit 285 detects a misalignment, the notification unit 286 outputs a message indicating that fact to the display device 16 via the output unit 284. The notification unit 286 notifies the operator of the image forming apparatus 1 by causing the display device 16 to display the message. The operator who has visually recognized the message can erase the authenticity determination result or perform the authenticity determination again.

[0108] When the determination unit 35a detects a misalignment of the printed matter based on the first read image Im1, it determines the authenticity of the printed matter based on the second read image Im2 while notifying the misalignment. In other words, the determination unit can determine the authenticity of the printed matter based on the first read image Im1 and the second read image Im2.

[0109] FIG. 14 is a diagram illustrating the first read image Im1 when there is no misalignment. FIG. 15 is a diagram illustrating the first read image Im1 when there is a misalignment.

[0110] When there is no misregistration in the printed matter 141, as shown in FIG. 14, the first read image Im1 includes only the read image of the printed matter 141 and does not include the edge of the printed matter 141. On the other hand, when there is misregistration in the printed matter 141, as shown in FIG. 15, the first read image Im1 includes the edge of the printed matter 141. The detection unit 285 can detect the shift and tilt misregistration of the printed matter 141 from the shift amount s and tilt amount t of this edge.

[0111] FIG. 16 is a flowchart showing an example of the authenticity determination process by the image reading device 100a included in the image forming apparatus 1. The operator of the image forming apparatus 1 places the printed matter to be determined for authenticity on the document reading glass 212 or inserts the printed matter into the ADF 21 and positions it by abutting against the abutting member. Thereafter, at the timing when the operator inputs an authenticity determination start operation via the operation unit of the image forming apparatus 1, the image reading device 100a starts the process of FIG. 16.

[0112] First, in step S161, the image reading device 100a inputs the first read image Im1 read by the first photoelectric conversion element 214 by the detection unit 285.

[0113] Subsequently, in step S162, the image reading device 100a detects, by the detection unit 285, the misregistration of the printed matter 141, that is, the shift misregistration and tilt misregistration.

[0114] Subsequently, in step S163, the image reading device 100a determines, by the detection unit 285, whether the shift misregistration of the printed matter 141 is equal to or greater than a predetermined shift threshold value or whether the tilt misregistration is equal to or greater than a predetermined tilt threshold value.

[0115] In step S163, if it is determined that the shift deviation of the printed matter 141 is equal to or greater than a predetermined shift threshold value, or the tilt deviation is equal to or greater than a predetermined tilt threshold value (step S163, Yes), in step S164, the image reading apparatus 100a outputs the detection result to the notification unit 286 by the detection unit 285. Then, the image reading apparatus 100a causes the display device 16 to display a predetermined message for notifying that the printed matter 141 is misaligned by the notification unit 286. Thereafter, the image reading apparatus 100a proceeds to the process of step S165.

[0116] On the other hand, in step S163, if it is determined that the shift deviation of the printed matter 141 is smaller than the predetermined shift threshold value and the tilt deviation is smaller than the predetermined tilt threshold value (step S163, No), the image reading apparatus 100a proceeds to the process of step S165.

[0117] The processes from step S165 to step S172 are the same as the processes from step S221 to step S228 in FIG. 13, and thus the overlapping description is omitted here.

[0118] In this way, the image reading apparatus 100a can determine the authenticity of the printed matter 141 based on the first read image Im1 and the second read image Im2.

[0119] As described above, in the present embodiment, the determination unit 35a determines the authenticity of the printed matter 141 based on the first read image Im1 and the second read image Im2. For example, the determination unit 35a includes a detection unit 285 that detects the misalignment of the printed matter 141 based on the first read image Im1, and a notification unit 286 that notifies the misalignment detected by the detection unit 285.

[0120] If the printed matter 141 is misaligned on the original document reading glass 212 or the ADF 21, the similarity between the extracted feature amount data and the registered feature amount data may be low and a false determination may be made even though the printed matter 141 is genuine. In the present embodiment, when the printed matter 141 is misaligned on the original document reading glass 212 or the ADF 21, the image reading apparatus 100a can notify the fact by the notification unit 286. Thereby, the operator of the image forming apparatus 1 can be notified of the misalignment and can be made aware that a false determination may occur.

[0121] In the present embodiment, although the configuration for notifying the misalignment of the printed matter 141 when the misalignment is detected has been shown, the present invention is not limited thereto. For example, when the detection unit 285 detects the misalignment of the printed matter 141, the determination unit 35a can also correct the second read image Im2 according to the misalignment. For example, image processing for rotating the second read image Im2 according to the tilt misalignment t or image processing for shifting the second read image Im2 according to the shift misalignment s can be performed to correct the second read image Im2. In this way, the image reading apparatus 100a can accurately perform the authenticity determination even when the printed matter 141 is misaligned.

[0122] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope described in the claims.

[0123] In the above-described embodiment, an electrophotographic image forming apparatus using toner has been exemplified, but the present invention is not limited thereto, and the embodiment is also applicable to a liquid ejection type image forming apparatus using a liquid such as ink. Since uneven adhesion, scattering, bleeding, etc. to the recording medium also occur in ink as in the case of toner, the same effects as those in the case of using toner can be obtained.

[0124] The numbers such as ordinal numbers and quantities used in the description of the embodiments are all exemplified for specifically describing the technology of the present invention, and the present invention is not limited to the exemplified numbers. Further, the connection relationship between the components is exemplified for specifically describing the technology of the present invention, and the connection relationship for realizing the functions of the present invention is not limited thereto.

[0125] Each function of the embodiment can be realized by one or more processing circuits. Here, the "processing circuit" in this specification refers to a processor programmed to execute each function by software like a processor implemented by an electronic circuit, an ASIC (Application Specific Integrated Circuit) designed to execute each function described above, a DSP (digital signal processor), an FPGA (field programmable gate array), and devices such as conventional circuit modules.

Explanation of Reference Numerals

[0126] 1 Image forming apparatus 3 First reading unit 21 ADF 212 Document reading glass 22 Scanner unit 23 Paper discharge tray 35 Determination unit 100 Image reading apparatus 200 Light source (an example of illumination unit) 202 First mirror 204 First mirror unit (an example of variable mechanism) 206 Second mirror 208 Third mirror 210 Second mirror unit 214 First photoelectric conversion element 215 First sensor board 216 Lens 222 Second photoelectric conversion element (an example of second reading unit) 223 Second sensor board 300 Image forming unit 240 Main scanning direction 250 Sub-scanning direction 281 Feature extraction unit 282 Registration unit 283 Comparison unit 284 Output unit 285 Detection unit 286 Notification unit 400 Paper feeding unit 110 Read image 111 Partial area 120, 130 Enlarged image 121, 122a, 122b, 131, 132 Micro area Im1 First read image Im2 Second read image P Paper

Prior art documents

Patent documents

[0127]

Patent Document 1

Claims

An image reading apparatus for reading a printed image formed on the surface of an object, comprising: a lighting unit; a first reading unit including a first photoelectric conversion element, for outputting a first read image obtained by reading the printed image illuminated by the lighting unit with the first photoelectric conversion element at a first reading magnification; a second reading unit including a second photoelectric conversion element, for outputting a second read image obtained by reading the printed image illuminated by the lighting unit with the second photoelectric conversion element at a second reading magnification; a determination unit for outputting authenticity information of the object determined based on the second read image; and having the second reading magnification is higher than the first reading magnification, the first reading unit includes a first mirror unit that reflects the reflected light of the light illuminated by the lighting unit by the object, and moves at a constant speed in a predetermined direction along the surface of the object; a second mirror unit that further reflects the reflected light by the first mirror unit and moves in the predetermined direction in conjunction with the movement of the first mirror unit at a speed that is 1 / 2 of the movement speed of the first mirror unit; a lens that transmits the reflected light reflected by the second mirror unit; and having the first mirror unit and the second mirror unit move in the predetermined direction in conjunction with each other to read the entire printed image, the second photoelectric conversion element is provided on the first mirror unit, the second reading unit reads the entire printed image by the second photoelectric conversion element moving in the predetermined direction as the first mirror unit moves. An image reading apparatus.

2. The image reading apparatus according to claim 1, wherein the second reading magnification is 2 times or more and 5 times or less of the first reading magnification.

3. The image reading apparatus according to claim 1 or 2, wherein the second reading magnification is 1:1 magnification.

4. The image reading apparatus according to any one of claims 1 to 3, wherein the determination unit determines the authenticity of the object based on the first read image and the second read image.

5. The determination unit includes a detection unit for detecting the misalignment of the object based on the first read image; and a notification unit for notifying the misalignment detected by the detection unit. The image reading apparatus according to claim 4.

6. An image forming apparatus comprising an image forming unit for forming an image on a recording medium; and the image reading apparatus according to any one of claims 1 to 5.

Images