Image reading apparatus and image forming apparatus

Abstract

When an image reading apparatus reads a print medium, reading is properly performed in either case of when the print medium is white and when the print medium is not white. A reading section is disposed at a prescribed position and reads an image formed on a print medium. A backing section is disposed at a position opposite the reading section and is capable of switching the color of the position of the background of the print medium when the reading section performs reading in a plurality of kinds according to the kind of the print medium and / or the color read from the print medium.

Description

Technical Field

[0001] This invention relates to image reading apparatus and image forming apparatus, and particularly to technology used when reading images with an image sensor or colorimeter. Background Technology

[0002] In an image forming apparatus, when printing on a printing medium such as paper or film, an image printed on the printing medium is read using a scanner or the like, and the read image data is compared with the original print data to check whether the printing was performed correctly.

[0003] Such inspections include, for example, using a scanner to read the entire printed image to determine if there are stains or if the ink adhesion is correct. Furthermore, when using a scanner for inspection, a colorimeter is used to measure the color of at least a portion of the printed image. Based on the colorimeter measurements, the color of the data read by the scanner is calibrated to ensure that color checks of the image read by the scanner can be performed correctly.

[0004] Patent Document 1 describes a technique for manually measuring color against a white background and a black background when calibrating multiple printers and obtaining the amount of ink adhering to a transparent printing medium using each printer.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-73307

[0006] In image reading devices that perform scanner readings and colorimeter color measurements, reading images printed on white media is common. Typically, the locations of the scanner and colorimeter are set against a white background. Because of the white background, it is possible to properly read and measure the color of images printed on white media.

[0007] However, when printing images onto transparent films and attempting to read and measure colors against a white background, the reading and color measurement processes become inaccurate.

[0008] For example, when printing on transparent films, there are instances where a technique called whitening is used. Whitening involves applying white to the printing area of ​​the film, allowing the images of each color to be formed cleanly.

[0009] When reading from a whitened area against a white background, there is a problem that the white of the printed surface cannot be distinguished from the white of the background, thus preventing the correct reading for inspection.

[0010] Here, Patent Document 1 describes a technique for manually switching between color measurement against a white background and color measurement against a black background. If inspection can be performed under each background color, appropriate checks can be conducted. However, in the actual printing process of a printing device, regardless of whether sheet-by-sheet paper is used as the printing medium or roll paper is used, many print jobs are required continuously to improve productivity. Therefore, if color measurement against a white background and color measurement against a black background are manually switched repeatedly, the inspection consumes a lot of effort and time, making it impossible to inspect the paper printed by the image forming apparatus in real time, thus reducing the productivity of the printing job.

[0011] Furthermore, while the issues regarding inspecting images printed on transparent films have been explained here, there are also cases where the white background is inappropriate when inspecting images printed on paper other than white. Summary of the Invention

[0012] The object of the present invention is to provide an image reading apparatus and an image forming apparatus that can properly read images regardless of whether the printing medium is white or not.

[0013] The image reading device of the present invention is characterized by comprising: a reading unit for reading an image formed on a printing medium; and a pad portion disposed opposite to the reading unit, which can be switched in multiple ways to become the color of the background of the printing medium when the reading unit is reading, depending on the type of printing medium and / or the color read from the printing medium.

[0014] Furthermore, the image forming apparatus of the present invention is characterized by comprising: a transport path for transporting a printing medium; an image forming unit disposed at a first position midway along the transport path and forming an image on the printing medium; a reading unit disposed at a second position midway along the transport path downstream in the transport direction from the first position and reading the image formed on the printing medium by the image forming unit; and a pad portion disposed at a position opposite the reading unit across the transport path, and capable of being switched in multiple ways to become the color of the background of the printing medium when the reading unit is reading, depending on the type of printing medium and / or the color read from the printing medium.

[0015] According to the present invention, the background color of the image being read by the reading unit can be switched to a color suitable for reading simply by selecting the type of paper used, thus enabling appropriate reading of various colored papers, transparent films, etc. Attached Figure Description

[0016] Figure 1 This is a configuration diagram illustrating an example of an image reading device according to an embodiment of the present invention.

[0017] Figure 2 This is a configuration diagram illustrating an example of an image forming apparatus connected to an image reading apparatus according to an embodiment of the present invention.

[0018] Figure 3 This is a diagram illustrating an example of the operation of the padding portion according to one embodiment of the present invention.

[0019] Figure 4 This is a flowchart illustrating a control example of one embodiment of the present invention. Detailed Implementation

[0020] Hereinafter, an embodiment of the present invention (hereinafter referred to as "this example") will be described in sequence with reference to the accompanying drawings.

[0021] [Overall Composition]

[0022] Figure 1 This example illustrates the configuration of the image reading device. Figure 2 The overall configuration of the image forming apparatus, which is connected to the image reading device in this example, is shown. Figure 1 and Figure 2 The diagram shows the internal structure of each device and the configuration of the transport path for the printing medium used in image formation.

[0023] First, in the context of Figure 1 Before describing the image reading device 300 shown, refer to Figure 2 The overall structure connected to the image forming apparatus will be explained.

[0024] exist Figure 2 In the example shown, the paper feed device 100, the image forming device 200, and the image reading device 300 are connected sequentially from the right side. Furthermore, although it is also possible to... Figure 2 The system shown, in which the image forming apparatus 200 is connected to the paper feed device 100 and the image reading device 300, is considered as an image forming apparatus as a whole. However, in the following description, the single device unit that performs the image forming process will be referred to as the image forming apparatus 200. Furthermore, the long strip of printing medium, i.e., the continuous printing medium 11, that can be installed in the image forming apparatus 200 in this example can be made of paper or film of various colors other than white, in addition to white paper or film. It can also be made of transparent or translucent film.

[0025] The paper feed device 100 supplies a continuous printing medium, namely a continuous printing medium 11, which is drawn from a supply side roller (not shown). Multiple rollers 101 to 103 are arranged in the transport path of the continuous printing medium 11. Furthermore, the paper feed device 100 performs the process of feeding the continuous printing medium 11 to the image forming apparatus 200 at a predetermined speed.

[0026] The image forming apparatus 200 includes a toner image forming unit 210, a transfer unit 220, and a fixing unit 230, serving as a processing unit constituting the image forming unit. The toner image forming unit 210 forms toner images of various colors, such as yellow (Y), magenta (M), cyan (C), black (K), and white (W), on the transfer belt 221 of the transfer unit 220.

[0027] The transfer unit 220 uses the transfer roller 222 to transfer the toners of various colors formed on the transfer belt 221 to the surface of the continuous printing medium 11.

[0028] The fixing unit 230 includes fixing rollers 231 and 232. By passing the continuous printing medium 11 between the fixing rollers 231 and 232, the continuous printing medium 11 is heated, and the transferred image, i.e., the printed image, is fixed onto the continuous printing medium 11. Furthermore, in the fixing unit 230, the continuous printing medium 11 is heated to, for example, about 100°C.

[0029] In the image forming apparatus 200, a plurality of rollers 201 to 205 are arranged in the middle of the transport path of the continuous printing medium 11, in addition to the transfer roller 222 and the fixing rollers 231 and 232. However, only the roller 205 that contacts the back side of the continuous printing medium 11 (the side opposite to the surface on which the printed image is formed) is arranged on the downstream side of the transport path compared with the fixing section 230 of the transport path; the surface side of the continuous printing medium 11 does not contact the roller. Each roller 201 to 205 is, for example, made of metal. Furthermore, in the following description, "downstream" and "upstream" refer to the downstream and upstream views observed from the transport direction of the continuous printing medium 11.

[0030] The continuous printing medium 11, in which the image is formed by the image forming apparatus 200, is sent to the image reading apparatus 300, which will be described next.

[0031] [Composition of an image reading device]

[0032] Next, refer to Figure 1 The configuration of the image reading device 300 will be described.

[0033] The image reading device 300 includes a cooling unit 320, a scanner unit 330, a coloring unit 350, and a colorimeter unit 360. The continuous printing medium 11 passes through these units in sequence.

[0034] The scanner unit 330 has a scanner pad portion 340, and the colorimeter unit 360 has a colorimeter pad portion 370.

[0035] Furthermore, multiple rollers 301 to 310 are arranged along the transport path of the continuous printing medium 11 within the image reading device 300. Each roller 301 to 310 is, for example, made of metal.

[0036] The continuous printing medium 11, delivered to the interior of the image reading device 300, passes near the cooling unit 320. Multiple cooling fans 321-323 are arranged in the cooling unit 320 to cool the continuous printing medium 11. Figure 1 In this configuration, a continuous printing medium 11 is vertically conveyed from top to bottom, and three vertically arranged cooling fans 321-323 are used to cool the conveyed continuous printing medium 11. The cooling fans 321-323 can be, for example, fans in the form of plate-shaped blades mounted on a rotating cylinder, known as Silco fans. Alternatively, fans equipped with propellers can also be used as cooling fans 321-323.

[0037] Continuous printing media 11, as in Figure 2 As explained, the fixing section 230 of the image forming apparatus 200 is heated to about 100°C, so when supplied to the image reading device 300, the continuous printing medium 11 is, for example, at a high temperature of about 70°C. Therefore, by supplying cooling air from the cooling fans 321 to 323 to the continuous printing medium 11, it is cooled to room temperature.

[0038] In the cooling unit 320 of the image reading device 300, multiple (three) cooling fans 321-323 need to be arranged in the conveying direction to provide sufficient cooling performance. In such a case, such as Figure 1 As shown, by vertically arranging the transport path of the continuous printing medium 11 and vertically (longitudinally) arranging the cooling fans 321-323, it is possible to miniaturize the image reading device 300. That is, if the transport path is arranged horizontally and multiple cooling fans are arranged in the horizontal direction, the image reading device 300 will be correspondingly larger in the horizontal direction, which is not preferable. With the configuration of this example, the image reading device 300 can be miniaturized.

[0039] In addition, Figure 1 The image shows three cooling fans 321-323 arranged vertically, but in cases where the horizontal width of the continuous printing medium 11 is wide, they can also be arranged horizontally. Figure 1 Multiple cooling fans are also arranged in a direction from the front to the inside. For example, three vertical fans and three horizontal fans can be installed, for a total of nine cooling fans.

[0040] Furthermore, for the transport path of the continuous printing medium 11, the roller 301, which is configured from the time the continuous printing medium 11 is picked up from the image reading device 300 until it is cooled by the cooling unit 320, is configured to contact the back side of the continuous printing medium 11, that is, the side opposite to the image forming surface. Additionally, as in... Figure 2 As explained, the roller 205 in the image forming apparatus 200, which is located downstream of the fixing unit 230, is also configured to contact the back side of the continuous printing medium 11.

[0041] Therefore, during the period from when the continuous printing medium 11, which has been heated in the fixing section 230 of the image forming apparatus 200, is cooled in the cooling unit 320, the image forming surface will not come into contact with rollers or the like. This prevents the toner image from becoming disordered due to the image formed on the continuous printing medium 11 coming into contact with the rollers at high temperatures, thus contributing to high-quality printed images.

[0042] The continuous printing medium 11, cooled by the cooling unit 320, is conveyed upwards via two rollers 302 and 303, then through rollers 304 and 305, and horizontally conveyed in the upper part of the image reading device 300. The scanner unit 330 is configured to be close to the surface of the horizontally conveyed continuous printing medium 11.

[0043] The scanner unit 330 is one of the reading units provided in the image reading device 300.

[0044] exist Figure 1 In the scanner unit 330 shown, image light entering the unit from the paper proximity surface 331 is reflected by multiple mirrors 332-336, and then imaged by the image sensor 338 via the optical system 337. The image recorded on the continuous printing medium 11 is then read by the image sensor 338. The image sensor 338 can be, for example, a line sensor of the CCD (Charge-Coupled Device) type. Alternatively, it can be a CMOS (Complementary Metal Oxide Semiconductor) type sensor. An image sensor that is not a line sensor can also be used.

[0045] The image data read by the scanner unit 330 is supplied to an image inspection processing unit (not shown) to perform inspection processing to check whether the image formed by the image forming apparatus 200 is the same as the original.

[0046] In addition, such as Figure 1As shown, by enabling the image sensor 338 to image within a certain optical path length within the scanner unit 330, the range capable of accurate imaging by the image sensor 338 can be expanded. Therefore, according to Figure 1 The configuration shown enables the image sensor 338 to accurately read the image formed on the surface of the continuous printing medium 11.

[0047] A scanner pad portion 340 is disposed on the opposite side of the paper approach surface 331 of the scanner unit 330, separated from the continuous printing medium 11. The configuration of the scanner pad portion 340 will be described later.

[0048] The scanner pad 340 is mounted on the roller holding member 381. The roller holding member 381 is a component that holds two rollers 305 and 306 disposed on the upstream and downstream sides of the scanner unit 330. The roller holding member 381 is connected to two feet 384 and 385 that can rotate around pivot points 382 and 383. Moreover, by rotating the feet 384 and 385 along the circularly curved guide grooves 386 and 387, the transport path of the continuous printing media 11 can be moved away from the scanner unit 330.

[0049] As the transport path of the continuously printed medium 11 moves away from the scanner unit 330 via the movement of the roller holding member 381, the scanner pad 340 mounted on the roller holding member 381 also moves in conjunction.

[0050] Additionally, on the side of the roller holding member 381 ( Figure 1 A coloring unit 350 is arranged on the left side. This coloring unit 350 can be moved horizontally by the drive of the moving part 352. Figure 1 It can move in the left and right directions. Moreover, when the roller holding member 381 moves away from the scanner unit 330, the coloring unit 350 can be moved to a position directly below the scanner unit 330.

[0051] The continuous printing medium 11 that has passed through the scanner unit 330 is vertically conveyed downwards by roller 306 and then horizontally conveyed again by roller 308.

[0052] The colorimeter unit 360 is configured to be close to the surface (upper side) of the continuous printing medium 11 being conveyed horizontally on the roller 308.

[0053] The colorimeter unit 360 is one of the reading units provided in the image reading device 300.

[0054] A colorimeter is built into the colorimeter unit 360 to perform color measurement processing to determine the color at specific locations on the continuous printing medium 11. Based on the colorimeter measurement results, for example, color calibration is performed on the image read by the scanner unit 330.

[0055] A colorimeter pad portion 370 is disposed on the opposite side of the paper approach surface 361 of the colorimeter unit 360, separated by the continuous printing medium 11. The configuration of the colorimeter pad portion 370 will be described later.

[0056] The continuous printing medium 11, which has passed through the colorimeter unit 360, is conveyed to the outside of the image reading device 300 via rollers 309 and 310 and wound onto a take-up roller (not shown).

[0057] [The composition of the scanner pad and the colorimeter pad]

[0058] Figure 3 The configuration of the scanner pad 340 disposed opposite to the scanner unit 330 and the colorimeter pad 370 disposed opposite to the colorimeter unit 360 is shown.

[0059] Figure 3 This is a side view of the scanner pad 340 and the colorimeter pad 370, with the continuous printing media 11 being fed from right to left. Figure 3 In the continuous printing medium 11, the upper side is the surface on which the image is formed by the image forming apparatus 200.

[0060] The scanner pad 340 includes a pad member 341. The pad member 341 is positioned opposite the paper approach surface 331 of the scanner unit 330 across the continuous printing medium 11.

[0061] The black portion 341B, whose entire surface is black, is adjacent to the white portion 341W, whose entire surface is white. Furthermore, the padding member 341 can be moved horizontally in the M1 direction by a drive mechanism (not shown), thereby switching between a state where the black portion 341B is directly below the paper approach surface 331 and a state where the white portion 341W is directly below the paper approach surface 331.

[0062] The colorimeter pad section 370 includes a pad member 371. The pad member 371 is positioned opposite the paper approach surface 361 of the colorimeter unit 360 across the continuous printing medium 11.

[0063] The padding member 371 is the same as the padding member 341, with the black portion 371B, whose entire surface is black, adjacent to the white portion 371W, whose entire surface is white. Moreover, the padding member 371 can be moved in the horizontal direction M2 by a drive mechanism (not shown), thereby switching between a state in which the black portion 371B is located directly below the paper approach surface 361 and a state in which the white portion 371W is located directly below the paper approach surface 361.

[0064] The background color is set for the portion of the padding members 341 and 371 positioned directly below the approach surfaces 331 and 361 of each sheet of paper, based on the color and type of the continuous printing medium 11 installed in the image forming apparatus 200 and the color in which the image is formed in the image forming apparatus 200. For example, the setting of the padding members 341 and 371 is performed by instruction from the control unit (not shown) of the image forming apparatus 200.

[0065] [Example of setting the colors of the scanner pad and colorimeter pad]

[0066] Figure 4 This is a flowchart illustrating an example of the process of setting the background color of the scanner pad 340 and the colorimeter pad 370.

[0067] First, the control unit of the image forming apparatus 200 determines whether the continuous printing medium 11 installed in the image forming apparatus 200 and the image reading device 300 is a white printing medium or a printing medium other than white (step S11). The printing operator presets the color of the installed continuous printing medium 11 on the operation panel of the image forming apparatus. In addition to various colors of paper and film, the printing medium other than white here also includes transparent or translucent films.

[0068] When the image is determined to be white in step S11 (the “white” in step S11), the control unit of the image forming apparatus 200 indicates that each pad part 340, 370 is switched in conjunction with the white part 341W, 371W so that it is directly below the paper approach surface 331, 361 (step S12).

[0069] In addition, when it is determined in step S11 that it is not white (other than white in step S11), the control unit of the image forming apparatus 200 determines whether the color of the toner (or the color of the ink) used when forming the image in the toner image forming unit 210 is only yellow Y, magenta M, cyan C, black K (step S13).

[0070] In step S13, when the color of the toner used to form the image is only yellow (Y), magenta (M), cyan (C), and black (K) (step S13 "YMCK only"), the control unit of the image forming apparatus 200 moves to step S12 and performs an indication that the white parts 341W and 371W are directly below the paper approach surfaces 331 and 361.

[0071] Furthermore, if the color of the toner used to form the image in step S13 is other than yellow (Y), magenta (M), cyan (C), or black (K) (step S13's "other than Y, M, C, K"), the control unit of the image forming apparatus 200 instructs that each pad portion 340, 370 be switched in conjunction with the black portion 341B, 371B so that it is directly below the paper approach surface 331, 361 (step S14). In addition, as a color other than yellow (Y), magenta (M), cyan (C), and black (K), there are cases where white is used for image formation. In the case of using white for image formation, a process called whitening is performed on a transparent film to form the substrate used when forming images of other colors.

[0072] Then, with the background colors of the scanner pad 340 and the colorimeter pad 370 set in step S12 or S14, the image reading device 300 performs reading of the printed continuous printing medium 11 using the scanner unit 330 and the colorimeter unit 360 (step S15).

[0073] As explained above, when the printing medium for image formation in the image forming apparatus 200 is white, or when the printing medium is other than white, and only yellow (Y), magenta (M), cyan (C), and black (K) toners (inks) are used, each pad component 341 and 371 becomes white. Therefore, it is possible to appropriately perform image reading for print image inspection using the scanner unit 330 and color reading for color inspection using the colorimeter unit 360 on a white background.

[0074] Furthermore, when the printing medium used for image formation in the image forming apparatus 200 is a printing medium other than white, and a toner (ink) other than yellow (Y), magenta (M), cyan (C), and black (K) is used, each pad component 341 and 371 becomes black. For example, when the image is formed using a white toner or ink on a continuous printing medium 11 formed of a transparent film, each pad component 341 and 371 becomes black. Therefore, it is possible to appropriately read images formed from white or other colors for print image inspection in the scanner unit 330 and for color inspection in the colorimeter unit 360, even against a background color other than white (i.e., black).

[0075] Therefore, in the image reading device 300 of this example, when reading an image at a location where a white image has been formed by whitening a transparent film, the back surfaces of the scanner unit 330 and the colorimeter unit 360 also become black, enabling accurate reading of the white image formation state. Furthermore, when reading an image formed using toners or inks other than white, the back surface becomes white, allowing for the same accurate reading as before.

[0076] [Variation Example]

[0077] Furthermore, in the above-described embodiments, an image is formed on a long, continuous printing medium, and the printed medium containing the formed image is read. In contrast, the present invention can also be applied to image forming apparatuses and image reading apparatuses that form images on printing media such as paper or film cut to a predetermined size, and read the printed media containing the formed images.

[0078] Furthermore, in the above-described implementation examples, such as Figure 2 As shown, an image reading device 300 is applied to an image forming apparatus 200 for reading images formed in the image forming apparatus 200. Alternatively, a printing medium with an image already formed in a separate image forming apparatus can be mounted onto a standalone image reading device for image reading.

[0079] Additionally, as an image forming apparatus 200, such as Figure 2 The configuration shown, in which the toner image is fixed to the printing medium using the fixing unit 230, is also an example. The present invention can also be applied to image forming apparatuses using inkjet printing or other methods that use ink.

[0080] Furthermore, in the above-described embodiment, the image reading device simultaneously switches the pad members 341 and 371 of both the scanner pad 340 and the colorimeter pad 370 to the same color. In contrast, it is also possible to configure the device to switch only one of the scanner pad 340 and the colorimeter pad 370 to multiple colors.

[0081] Furthermore, the color of the switching pad components 341 and 371 is a combination of white and black. This color combination can also be other combinations depending on the color of the printing medium read by the image reading device 300 and the color on which the image is formed on the printing medium. For example, the pad components 341 and 371 could also be a combination of white and gray.

[0082] In addition, Figure 4In the flowchart shown, the colors of the scanner pad 340 and the colorimeter pad 370 are switched based on two conditions: the color of the printing medium and the color used for image formation. Alternatively, the colors of either the scanner pad 340 or the colorimeter pad 370 can be switched based solely on either the color of the printing medium or the color used for image formation. For example, the colors of either the scanner pad 340 or the colorimeter pad 370 can be switched when the color used for image formation is only yellow (Y), magenta (M), cyan (C), or black (K), or when it is white or a color other than these.

[0083] in addition, Figure 1 The configuration shown as the scanner unit 330 for image reading is one example, but image reading can also be performed using sensors with other configurations. For example, it can also be configured as a scanner that uses an optical system without lenses or the like, with a line sensor arranged on the paper proximity surface 331 for image reading.

[0084] Explanation of reference numerals in the attached figures

[0085] 11…Continuous printing media, 100…Paper feeder, 200…Image forming apparatus, 201-205…Rollers (guide components), 210…Toner image forming unit, 220…Transfer section, 221…Transfer belt, 222…Transfer roller, 230…Fixing section, 231, 232…Fixing rollers, 300…Image reading device, 301-310…Rollers (guide components), 320…Cooling unit, 321-323…Cooling fan, 330…Scanner unit, 331…Paper approach surface, 332-336…Mirrors, 33… 7…Optical system, 338…Image sensor, 340…Scanner pad, 341…Pad component, 341B…Black part, 341W…White part, 350…Coloring unit, 352…Moving part, 360…Colorimeter unit, 361…Paper approach surface, 370…Colorimeter pad, 371…Pad component, 371B…Black part, 371W…White part, 380…Variable transport path, 381…Roller holding component, 382, ​​383…Rotation pivot, 384, 385…Foot, 386, 386…Guide groove.

Claims

1. An image reading apparatus characterized by comprising: Possessing: a reading section that reads an image formed on a print medium; and a pad section that is disposed at a position opposite the reading section and that is capable of switching the color of the position of the background of the print medium when the reading section is reading, according to the kind of the print medium and / or the color being read from the print medium, among a plurality of kinds, the reading section possesses an image sensor and a colorimeter, in the image reading apparatus, a conveyance path that conveys the print medium is bent in the up-down direction within the image reading apparatus, the image sensor and the colorimeter are disposed at different positions in the up-down direction with respect to the conveyance path, and are disposed so as to partially overlap in the up-down direction.

2. The image reading apparatus according to claim 1, characterized in that the image sensor reads an image formed on the print medium, and the colorimeter measures the color of the image formed on the print medium.

3. The image reading apparatus according to claim 2, characterized in that the pad section is possessed at the disposition position of the image sensor and at the disposition position of the colorimeter, respectively.

4. The image reading apparatus according to claim 3, characterized in that the pad section disposed opposite the image sensor and the pad section disposed opposite the colorimeter are switched to the same color in conjunction.

5. The image reading apparatus according to any one of claims 2 to 4, characterized in that the image sensor is a line image sensor.

6. The image reading apparatus according to claim 1, characterized in that the print medium that the reading section reads is a medium of a color other than white, when the reading section reads a position on which white image formation has been performed on the print medium, the pad section is set to a color other than white.

7. The image reading apparatus according to claim 6, characterized in that the medium of a color other than white is a transparent medium.

8. The image reading apparatus according to any one of claims 1 to 4, characterized in that the pad section is capable of being switched to white and black.

9. An image forming apparatus characterized by comprising: Possessing: a conveyance path that conveys a print medium; an image forming section that is disposed at a first position in the middle of the conveyance path and that forms an image on the print medium; a reading section that is disposed at a second position and that reads the image formed on the print medium by the image forming section, wherein the second position is downstream in the conveyance direction compared to the first position in the middle of the conveyance path; and a pad section that is disposed at a position opposite the reading section across the conveyance path and that is capable of switching the color of the position of the background of the print medium when the reading section is reading, according to the kind of the print medium and / or the color being read from the print medium, among a plurality of kinds, the reading section possesses an image sensor and a colorimeter, the conveyance path is bent in the up-down direction within the image forming apparatus, the image sensor and the colorimeter are disposed at different positions in the up-down direction with respect to the conveyance path, and are disposed so as to partially overlap in the up-down direction.

Images