Image forming device

Abstract

To provide an image forming apparatus that can appropriately perform image reading after image formation and can prevent deterioration after fixing of an image formed on a print medium.SOLUTION: An image forming apparatus comprises: an image forming unit that is arranged at a first place in the middle of a conveyance path for conveying a print medium, forms an image on one face of the print medium, and fixes the formed image by heating; a cooling unit that is arranged at a second place that is downstream of the first place in a conveyance direction and blows air for cooling to the print medium to cool the print medium; and a reading unit that is arranged at a third place that is downstream of the second place in the conveyance direction and reads the image formed on the print medium in the image forming unit. Between the first place and the second place, the image forming apparatus is provided with a guide member in contact with the other face of the print medium and is not provided with a guide member in contact with one face of the print medium.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus, and more particularly to a technique applied when an image formed by an image sensor or a colorimeter is read. [Background technology]

[0002] When an image forming device prints on a print medium such as paper or film, the image printed on the print medium is read using a scanner or the like, and the read image data is compared with the print document data to check whether the printing was successful. In such an inspection, for example, the entire printed image is read by a scanner to determine whether the printing is appropriate, such as whether there are any stains on the printed image, whether the amount of ink applied is correct, etc. When inspecting with a scanner, the colors of at least a portion of the printed image are measured by a colorimeter, and the colors of the data read by the scanner are calibrated based on the colors measured by the colorimeter, so that the color inspection of the image read by the scanner is performed correctly.

[0003] Patent Document 1 describes a technique for cooling the continuous paper with a cooling fan after a fixing process in an image forming apparatus that prints on both sides of the continuous paper. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-98764 Summary of the Invention [Problem to be solved by the invention]

[0005] When forming an image using an image forming apparatus, the toner image formed on the print medium must be fixed in a thermal fixing process. This fixing process requires heating the print image to a high temperature. As described above, when scanning and inspecting the image formed using a scanner or other device after image formation, it is preferable to inspect the image on the print medium after it has returned to room temperature. Specifically, because thermochromism occurs, in which the color of the print medium changes depending on its temperature, reading at room temperature is necessary to accurately inspect the color. Furthermore, the scanner and colorimeter that make up the reading unit have a usable temperature range, and reading at high temperatures is not recommended.

[0006] Therefore, when reading an image formed by an image forming device using a scanner or the like, it is preferable to wait until the print medium has returned to room temperature before reading it. For this reason, as described in Patent Document 1, for example, one possible approach is to actively cool the continuous paper by using a cooling fan to cool the continuous paper that has passed through the fixing unit of the image forming device. As a configuration for cooling the print medium other than using a cooling fan, for example, a known method is to place a metal roller in the print medium transport path and cool the print medium by contact with the roller.

[0007] Meanwhile, another problem caused by heating the print medium in the fixing process is that the heated print medium comes into contact with rollers arranged in the transport path, causing degradation such as unevenness in the printed image. That is, after being heated in the fixing process, the image forming surface comes into contact with the rollers before the temperature drops to the point where the wax contained in the toner hardens, which can cause degradation such as unevenness in the printed image.

[0008] Therefore, in order to prevent image degradation after the print medium has passed through the fixing unit, it is undesirable for the image-forming surface to come into contact with rollers in the transport path until the print medium returns to room temperature. However, as in the configuration of the printing machine described in Patent Document 1, for example, many rollers are typically arranged in the transport path for the print medium. Therefore, in conventional printing machines, the image-forming surface of the print medium comes into contact with rollers even immediately after the print medium has passed through the fixing unit, and as the print medium comes into contact with the rollers, some degree of image degradation is unavoidable.

[0009] SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that can properly read an image after image formation and can prevent deterioration of the image formed on the print medium after fixing. [Means for solving the problem]

[0010] The image forming apparatus of the present invention comprises: It is a long print medium a conveyance path for conveying a print medium; an image forming unit disposed at a first location along the conveyance path, which forms an image on one side of the print medium and fixes the formed image by heating; and an image forming unit disposed at a second location along the conveyance path downstream of the first location in the conveyance direction, which fixes the image on the print medium. The printing medium is printed without contact. a cooling unit that blows cooling air to cool the print medium; and a reading unit that is disposed at a third location downstream in the conveying direction from the second location in the middle of the conveying path and that reads the image formed on the print medium by the image forming unit. 、 Between the first and second locations of the conveying path and a guide member that contacts the other side of the print medium to change the transport direction of the print medium, and between the first and second locations of the transport path, there is no guide member that contacts the print medium to change the transport direction of the print medium on one side of the print medium. It is characterized by: [Effects of the Invention]

[0011] According to the present invention, the roller does not come into contact with the image-forming surface of the print medium from the time of the fixing process for image formation until the time of cooling in the cooling section, thereby preventing deterioration of the formed image. After cooling in the cooling section, reading is performed in the reading section, so that proper reading for inspection can be performed. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a configuration diagram showing an example of an image reading device according to an embodiment of the present invention; [Figure 2] 1 is a configuration diagram showing an example of the overall configuration of an image forming apparatus to which an image reading device according to an embodiment of the present invention is connected; DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention (hereinafter referred to as "this example") will be described below with reference to the accompanying drawings.

[0014] [Overall configuration] Figure 1 shows the configuration of the image reading device of this example, and Figure 2 shows the overall configuration of the image forming device to which the image reading device of this example is connected. Figures 1 and 2 show the configuration of the print medium transport path where image formation takes place inside each device.

[0015] First, before describing the image reading device 300 shown in FIG. 1, the overall configuration connected to the image forming device will be described with reference to FIG. In the example shown in Figure 2, from right to left, a paper feeder 100, an image forming device 200, and an image reading device 300 are connected. Note that the entire system in which the paper feeder 100 and the image reading device 300 are connected to the image forming device 200 as shown in Figure 2 can also be considered an image forming device, but in the following explanation, the image forming device 200 will be referred to as a single device that performs the image formation process. Furthermore, the continuous print medium 11, which is a long print medium that can be loaded into the image forming device 200 in this example, can be a medium made of white paper or film, or a medium made of paper or film of various colors other than white. Furthermore, it can also be a medium made of transparent or translucent film.

[0016] The paper feeder 100 is supplied with continuous printing medium 11 pulled out from a supply roll (not shown), and multiple rollers 101-103 are arranged in the transport path of the continuous printing medium 11. The paper feeder 100 then performs a process of feeding the continuous printing medium 11 to the image forming device 200 at a predetermined speed. The rollers 101-103 function as guide members for the continuous printing medium 11.

[0017] Image forming apparatus 200 includes, as processing sections that make up the image forming section, toner image forming unit 210, transfer section 220, and fixing section 230. Toner image forming unit 210 forms toner images of each color, such as yellow Y, magenta M, cyan C, black K, and white W, on transfer belt 221 of transfer section 220. The transfer unit 220 transfers the toner images of each color formed on the transfer belt 221 onto the surface of the continuous print medium 11 by the transfer rollers 222 .

[0018] The fixing unit 230 includes fixing rollers 231 and 232, and heats the continuous printing medium 11 by passing the continuous printing medium 11 between the fixing rollers 231 and 232, thereby fixing the transferred print image onto the continuous printing medium 11. In the fixing unit 230, the continuous printing medium 11 is heated to, for example, about 100°C.

[0019] In addition to the transfer roller 222 and fixing rollers 231, 232, multiple rollers 201-205 are arranged as guide members along the transport path for the continuous printing medium 11 inside the image forming apparatus 200. However, only roller 205, which comes into contact with the back side of the continuous printing medium 11 (the side opposite to the side on which the printed image is formed), is arranged downstream of the fixing unit 230 on the transport path in the transport direction; the front side of the continuous printing medium 11 does not come into contact with any roller. Each of the rollers 201-205 is made of metal, for example. In the following description, references to downstream and upstream refer to downstream and upstream as viewed in the transport direction of the continuous printing medium 11. The continuous print medium 11 on which the print image has been formed by the image forming apparatus 200 is sent to an image reading apparatus 300 connected to the image forming apparatus 200 .

[0020] [Image reader configuration] Next, the configuration of the image reading device 300 will be described with reference to FIG. The image reading device 300 includes a cooling unit 320, a scanner unit 330, a shading unit 350, and a colorimeter unit 360. The continuous print medium 11 passes through these units in order. The scanner unit 330 includes a scanner backing portion 340, and the colorimeter unit 360 includes a colorimeter backing portion 370. Additionally, a plurality of rollers 301-310 are arranged along the transport path of the continuous print medium 11 within the image reading device 300 as guide members for the continuous print medium 11. Each of the rollers 301-310 is made of, for example, metal, and is a guide member that rotates following the movement of the print medium and does not have a driving means (i.e., a guide member that rotates with the movement of the print medium).

[0021] The continuous print medium 11 transported inside the image reading device 300 passes through roller 301, which is a guide member, and then passes near a cooling unit 320, which is a cooling section that cools the continuous print medium 11. Roller 301 comes into contact with the back side of the continuous print medium 11 (the side opposite to the surface on which the printed image is formed) and turns the continuous print medium 11 downward in the transport direction. The cooling unit 320 is provided with a plurality of cooling fans 321-323 for cooling the continuous print medium 11. In FIG. 1, the continuous print medium 11 is transported vertically from top to bottom, and the three vertically arranged cooling fans 321-323 cool the transported continuous print medium 11. For example, the cooling fans 321-323 may be called sirocco fans, which are fans with plate-shaped blades attached to a rotating cylinder. Alternatively, the cooling fans 321-323 may be fans equipped with propellers.

[0022] Each of the cooling fans 321 to 323 is arranged at an angle, and blows cooling air A1, A2, A3 onto the continuous print medium 11 from diagonally below toward the upstream side of the continuous print medium 11, so that the cooling air escapes above the image reading device 300. A plurality of cooling fans 311 are arranged above the housing of the image reading device 300 to exhaust the cooling air to the outside of the device. The rollers 301 disposed above the cooling unit 320 are on the opposite side of the continuous print medium 11 from the path through which the cooling air A1, A2, and A3 passes. Therefore, the cooling air A1, A2, and A3 do not pass through the locations where the rollers 301 are disposed, and the rollers 301 do not obstruct the passage of the cooling air A1, A2, and A3.

[0023] 2, the continuous print medium 11 is heated to about 100°C in the fixing unit 230 of the image forming device 200, and so is at a high temperature of, for example, about 70°C when it is supplied to the image reading device 300. For this reason, cooling air A1, A2, A3 from cooling fans 321 to 323 is blown onto the continuous print medium 11 to cool it to about room temperature.

[0024] When it is necessary to arrange multiple (three) cooling fans 321-323 in the transport direction to provide uniform cooling performance, as shown in Fig. 1, arranging the transport path for the continuous print medium 11 vertically and arranging the cooling fans 321-323 vertically (longitudinally) contributes to the miniaturization of the image reading device 300. In other words, if the transport path is arranged horizontally and multiple cooling fans are arranged horizontally, the image reading device 300 becomes larger in the horizontal direction, which is not desirable, but the configuration of this example makes it possible to configure the image reading device 300 to be compact.

[0025] 1 shows three cooling fans 321-323 lined up in the vertical direction, but if the width of the continuous print medium 11 is wide, multiple cooling fans may also be lined up in the horizontal direction (from the front to the back in FIG. 1). For example, a total of nine cooling fans may be installed: three in the vertical direction and three in the horizontal direction.

[0026] In addition, roller 301, which is arranged along the transport path of continuous print medium 11 between when continuous print medium 11 is taken into image reading device 300 and when it is cooled by cooling unit 320, is arranged so as to contact the back side of continuous print medium 11, i.e., the side opposite to the image forming surface. Also, as described in Figure 2, roller 205, which is arranged downstream of fixing unit 230 in image forming device 200, is also arranged so as to contact the back side of continuous print medium 11.

[0027] As a result, the image-forming surface of the continuous printing medium 11, which has been heated by the fixing section 230 of the image forming device 200, does not come into contact with guide members such as rollers until the continuous printing medium 11 is cooled by the cooling unit 320. This prevents the toner image from deteriorating due to the image formed on the continuous printing medium 11 coming into contact with rollers at a high temperature, contributing to higher image quality of printed images. In the configurations of Figures 1 and 2, two rollers 205, 301 are arranged between the fixing section 230 and the cooling unit 320, but if possible, a simpler configuration in which only one of the rollers 205 or 301 is arranged may also be used.

[0028] The continuous print medium 11 cooled by the cooling unit 320 is transported upward by two guide members, rollers 302 and 303, and then passes through other guide members, rollers 304 and 305, before being transported horizontally in the upper part of the image reading device 300. The scanner unit 330 is disposed close to the surface of the continuous print medium 11 being transported horizontally. While FIG. 1 shows an example in which multiple guide members are disposed on the transport path from the cooling unit 320 to the scanner unit 330, it is sufficient to dispose at least one guide member. Furthermore, the guide members (rollers) on the transport path after the cooling unit 320 may contact either the front or back side of the continuous print medium 11. Even if the guide members come into contact with the surface of the continuous print medium 11, the continuous print medium 11 has already been cooled to room temperature, so the printed image will not be deteriorated.

[0029] The scanner unit 330 is one of the reading units included in the image reading device 300. In the scanner unit 330 shown in FIG. 1, image light entering the unit from a paper-proximate surface 331 is reflected by multiple mirrors 332-336, passes through an optical system 337, and is focused on an image sensor 338. The image recorded on the continuous print medium 11 is then read by the image sensor 338. The image sensor 338 can be configured, for example, as a CCD (Charge Coupled Device) type line sensor. Alternatively, the image sensor 338 may be configured as a CMOS (Complementary Metal Oxide Semiconductor) type sensor. An image sensor other than a line sensor may also be used.

[0030] The image data read by the scanner unit 330 is supplied to an image inspection processing unit (not shown), where inspection processing is performed to determine whether the image formed by the image forming apparatus 200 is the same as the original. 1, by forming an image on the image sensor 338 while there is a certain optical path length within the scanner unit 330, it is possible to widen the range over which an image can be correctly formed on the image sensor 338. Therefore, with the configuration shown in FIG. 1, the image formed on the surface of the continuous print medium 11 can be correctly read by the image sensor 338.

[0031] A scanner backing section 340 having a background plate of white or the like is disposed on the opposite side of the scanner unit 330 from the paper-proximate surface 331 with the continuous print medium 11 interposed therebetween. The scanner backing section 340 is attached to a roller holding member 381. The roller holding member 381 is a member that holds two rollers 305, 306, which are arranged on the upstream and downstream sides of the scanner unit 330. The roller holding member 381 is connected to two legs 384, 385 that are rotatable around pivot points 382, ​​383. The legs 384, 385 can be rotated along circularly curved guide grooves 386, 386 to move the transport path of the continuous print medium 11 away from the scanner unit 330.

[0032] When the roller holding member 381 moves to separate the transport path of the continuous print medium 11 from the scanner unit 330, the scanner backing portion 340 attached to the roller holding member 381 also moves in conjunction with the roller holding member 381. In addition, a shading unit 350 is disposed beside the roller holding member 381 (on the left side in FIG. 1). This shading unit 350 is movable in the horizontal direction (left and right direction in FIG. 1) by being driven by a moving section 352. Then, when the roller holding member 381 has moved away from the scanner unit 330, the shading unit 350 can be moved to a position directly below the scanner unit 330.

[0033] After passing through the scanner unit 330, the continuous print medium 11 is transported vertically downward by rollers 306, and then transported horizontally again by rollers 308. A colorimeter unit 360 is disposed adjacent to the surface (upper surface) of the continuous printing medium 11 that is now transported horizontally by the rollers 308.

[0034] The colorimeter unit 360 is one of the reading units included in the image reading device 300. The colorimeter unit 360 has a built-in colorimeter and performs color measurement processing to measure the color of a specific location on the continuous print medium 11. Based on the color measurement results from the colorimeter, color calibration of an image read by the scanner unit 330, for example, is performed. A colorimeter backing section 370 having a background plate of white or the like is disposed on the opposite side of the colorimeter unit 360 from the paper-proximate surface 361 with the continuous print medium 11 interposed therebetween.

[0035] The continuous print medium 11 that has passed through the colorimeter unit 360 is transported to the outside of the image reading device 300 via rollers 309 and 310 and is wound up onto a winding roll (not shown).

[0036] [Variations] In the above-described embodiment, an image is formed on a continuous long print medium and the print medium on which the image is formed is read. However, the present invention may also be applied to an image forming device or an image reading device that forms an image on a print medium such as paper or film cut to a specified size one sheet at a time and then reads the print medium on which the image is formed.

[0037] 1 is just one example, and images may be read by sensors of other configurations. For example, images may be read by a scanner having a line sensor disposed on the paper-proximate surface 331, without using an optical system such as a lens. [Explanation of symbols]

[0038] 11...continuous printing medium, 100...paper feeder, 200...image forming device, 201-205...rollers (guide members), 210...toner image forming unit, 220...transfer section, 221...transfer belt, 222...transfer roller, 230...fixing section, 231, 232...fixing roller, 300...image reading device, 301-310...rollers (guide members), 311...cooling fan, 320...cooling unit, 321-323...cooling fan, 330...scanner unit, 331...paper proximity surface, 332-336...mirror , 337...optical system, 338...image sensor, 340...scanner backing section, 341...backing member, 341B...black section, 341W...white section, 350...shading unit, 352...moving section, 360...colorimeter unit, 361...paper adjacent surface, 370...colorimeter backing section, 371...backing member, 371B...black section, 371W...white section, 380...transport path variable section, 381...roller holding member, 382, ​​383...rotation fulcrum, 384, 385...legs, 386, 386...guide groove

Claims

1. A conveying path for conveying a continuous print medium, which is a long print medium; an image forming unit that is disposed at a first location along the conveying path and that forms an image on one side of the print medium and fixes the formed image by heating; a cooling unit that is disposed at a second location on the transport path downstream of the first location in the transport direction and that cools the print medium without coming into contact with the print medium; a reading unit disposed at a third location on the conveying path downstream of the second location in the conveying direction, the reading unit reading an image formed on the print medium by the image forming unit; a guide member that is provided between the first location and the second location of the transport path and that contacts the other side of the print medium to change the transport direction of the print medium; Between the first and second locations of the transport path, there is no guide member for contacting the print medium and changing the transport direction of the print medium with respect to the one side of the print medium. Image forming device.

2. The guide member is characterized in that it changes the conveying direction so that the print medium is conveyed from above to below. The image forming apparatus according to claim 1 .

3. The guide member is characterized in that it changes the conveying direction of the print medium to a vertical direction. The image forming apparatus according to claim 1 .

4. the reading unit is an image sensor that reads an image formed on the print medium, a colorimeter for measuring the color of an image formed on the print medium is disposed at a fourth location downstream in the transport direction from the third location on the transport path where the reading unit is disposed; The image forming apparatus according to claim 1 .

5. a guide member for transporting the print medium is also provided between the third location of the transport path where the reading unit is disposed and the fourth location of the transport path where the colorimeter is disposed. The image forming apparatus according to claim 4 .

6. The guide member is characterized in that it is made of a metal roller. The image forming apparatus according to claim 1 .

7. The cooling air blown from the cooling unit is directed to the upstream side of the transport path along which the print medium is transported. The image forming apparatus according to claim 1 .

8. The cooling unit is characterized in that no guide member for the transport path is disposed in the path through which the cooling air blown from the cooling unit escapes. The image forming apparatus according to claim 7 .

9. a guide member that contacts the one surface of the print medium is provided between the second location of the transport path where the cooling unit is located and the third location of the transport path where the reading unit is located. The image forming apparatus according to claim 1 .

10. The guide member is configured by a roller that moves in conjunction with the transport of the print medium. The image forming apparatus according to claim 1 .

Images