JP7211102B2 - Image reading device and image forming system - Google Patents

Description

The present invention relates to an image reading device and an image forming device.

Conventionally, an image reading unit arranged on the conveying path of paper after image formation reads the image on the paper to generate image data, compares it with the reference image data, and detects errors in color, position, and image. An image forming system that inspects folds and the like is used.

As a method for reading an image on paper after image formation, for example, in an image forming system that reads a gradation pattern formed on the paper at regular intervals, performs calibration, and updates a gradation correction table, job There has been proposed a method for creating a calibration report after the completion of (see, for example, Patent Document 1).

In addition, in the image forming apparatus that determines whether the front and back misalignment of the image on the paper, color misalignment, density, toner stain, etc. on the downstream side of the image forming unit is normal, we have developed an image forming device that saves the cause of error for each page. (See Patent Document 2, for example).

By the way, the image reading unit that reads images reads images while conveying paper (especially continuous paper), so foreign matter (dust and paper dust) tends to adhere to the reading surface of the image reading unit (reading glass). . If foreign matter adheres to the image reading unit, even if there is no abnormality in the image formed on the paper, the image caused by the foreign matter will be included in the scanned image. A problem arises in that it is erroneously determined that there is an abnormality.

In order to solve the above problem, a blowing unit that blows air between the paper and the image reading unit is provided to prevent foreign matter from adhering to the image reading unit (see, for example, Japanese Unexamined Patent Application Publication No. 2002-100003).

JP 2014-107648 A JP 2014-119668 A JP 2015-050559 A

However, for example, when excessive air is blown by the air blower, the temperature of the paper changes greatly, and the temperature change causes the color of the read image to change. A phenomenon occurs in which the molecular structure changes reversibly due to heat). When the color of the read image changes due to the thermochromism phenomenon, there is a problem that the color of the image on the paper cannot be read correctly in the image reading section.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image reading apparatus and an image forming apparatus capable of correctly reading the color of an image on a sheet while preventing foreign matter from adhering to the image reading section.

An image reading device according to the present invention includes:
an image reading unit that reads an image formed on a sheet;
a temperature detection unit that detects the temperature of the paper;
a blowing unit that blows air between the sheet and the image reading unit;
a control unit that controls the amount of air blown by the air blow unit so that the amount of change in the temperature detected by the temperature detection unit is small;
Prepare.

An image forming apparatus according to the present invention includes:
an image reading unit that reads an image formed on a sheet;
a temperature detection unit that detects the temperature of the paper;
a blowing unit that blows air between the sheet and the image reading unit;
a control unit that controls the amount of air blown by the blower so that the amount of change in the temperature detected by the temperature detection unit is small;
Prepare.

According to the present invention, it is possible to correctly read the color of the image on the paper while preventing foreign matter from adhering to the image reading section.

1 is a diagram schematically showing the overall configuration of an image forming system according to an embodiment; FIG. 2 is a diagram showing main parts of a control system of the image forming apparatus according to the embodiment; FIG. 1 is a diagram schematically showing the configuration of an image reading device according to an embodiment; FIG. 4 is a flow chart showing an operation example of the image reading apparatus according to the present embodiment;

Hereinafter, this embodiment will be described in detail based on the drawings. FIG. 1 is a diagram schematically showing the overall configuration of an image forming system 100 according to this embodiment. FIG. 2 shows the main part of the control system of the image forming apparatus 2 included in the image forming system 100 according to this embodiment. The image forming system 100 uses, as a recording medium, a long paper P (also referred to as continuous paper) indicated by a thick line in FIG. This is a system for forming an image on a length of paper P or paper S. Here, the long paper P is paper having a length exceeding, for example, the width of the main body of the image forming apparatus 2 in the transport direction.

As shown in FIG. 1, the image forming system 100 includes a paper feeding device 1, an image forming device 2, an image reading device 1, an image forming device 2, and an image reading device from the upstream side along the transport direction of the long paper P (hereinafter also referred to as the "paper transport direction"). A device 3 and a paper discharge device 4 are connected to each other. In this embodiment, the image forming apparatus 2 and the image reading apparatus 3 are connected inline. The paper feeding device 1 and the paper discharging device 4 are used when forming an image on the long paper P. FIG.

The paper feeding device 1 is a device that feeds the long paper P to the image forming device 2 . As shown in FIG. 1, in the housing of the paper feeder 1, a roll of long paper P is wound around a support shaft and rotatably held. The paper feeding device 1 conveys the long paper P wound around the support shaft to the image forming device 2 at a constant speed via a plurality of conveying roller pairs (e.g., delivery rollers, paper feeding rollers, etc.). do. A paper feeding operation of the paper feeding device 1 is controlled by a control unit 101 provided in the image forming device 2 .

In the paper feeder 1, the long paper P does not necessarily have to be held in a roll shape, and a plurality of long papers P of a predetermined size (for example, 210 [mm]×1200 [mm]) are held. It's okay to be there.

The image forming apparatus 2 is an intermediate transfer type color image forming apparatus using an electrophotographic process technology. That is, the image forming apparatus 2 primarily transfers each color toner image of Y (yellow), M (magenta), C (cyan), and K (black) formed on the photosensitive drum 413 onto the intermediate transfer belt 421, After the four-color toner images are superimposed on the intermediate transfer belt 421, secondary transfer is performed onto the long paper P fed from the paper feeding device 1 or the paper S fed from the paper feeding tray units 51a to 51c. By doing so, an image is formed.

In the image forming apparatus 2, the photosensitive drums 413 corresponding to the four colors of YMCK are arranged in series in the running direction of the intermediate transfer belt 421, and the toner images of the respective colors are sequentially transferred onto the intermediate transfer belt 421 in one procedure. A tandem system is used.

As shown in FIG. 2 , the image forming apparatus 2 includes an image reading section 10 , an operation display section 20 , an image processing section 30 , an image forming section 40 , a sheet conveying section 50 , a fixing section 60 and a control section 101 .

The control unit 101 includes a CPU (Central Processing Unit) 102, a ROM (Read Only Memory) 103, a RAM (Random Access Memory) 104, and the like. The CPU 102 reads out a program corresponding to the processing content from the ROM 103 , develops it in the RAM 104 , and centrally controls the operation of each block of the image forming apparatus 2 in cooperation with the developed program. At this time, various data stored in the storage unit 72 are referred to. The storage unit 72 is composed of, for example, a nonvolatile semiconductor memory (so-called flash memory) or a hard disk drive.

The control unit 101 transmits and receives various data to and from an external device (for example, a personal computer) connected to a communication network such as a LAN (Local Area Network) or a WAN (Wide Area Network) via the communication unit 71. conduct. For example, the control unit 101 receives image data transmitted from an external device, and forms an image on the long sheet P or the sheet S based on this image data (input image data). The communication unit 71 is composed of a communication control card such as a LAN card, for example.

The image reading unit 10 includes an automatic document feeder 11 called an ADF (Auto Document Feeder), a document image scanning device 12 (scanner), and the like.

The automatic document feeder 11 transports the document D placed on the document tray by the transport mechanism and sends it to the document image scanning device 12 . The automatic document feeder 11 makes it possible to continuously read images (including both sides) of a large number of documents D placed on the document tray at once.

The document image scanning device 12 optically scans the document conveyed onto the contact glass from the automatic document feeder 11 or the document placed on the contact glass, and converts the light reflected from the document into a CCD (Charge Coupled Device). ) An image is formed on the light-receiving surface of the sensor 12a, and the document image is read. The image reading unit 10 generates input image data based on the result of reading by the document image scanning device 12 . Predetermined image processing is performed on the input image data in the image processing section 30 .

The operation display unit 20 is composed of, for example, a liquid crystal display (LCD) with a touch panel, and functions as a display unit 21 and an operation unit 22 . The display unit 21 displays various operation screens, image states, operation states of respective functions, and the like according to display control signals input from the control unit 101 . The operation unit 22 includes various operation keys such as a numeric keypad and a start key, receives various input operations by the user, and outputs operation signals to the control unit 101 .

The image processing unit 30 includes a circuit or the like that performs digital image processing on input image data in accordance with initial settings or user settings. For example, the image processing unit 30 performs tone correction based on tone correction data (tone correction table) under the control of the control unit 101 . The image processing unit 30 also performs various types of correction processing such as color correction and shading correction, compression processing, etc., on the input image data, in addition to tone correction. The image forming section 40 is controlled based on the image data subjected to these processes.

The image forming section 40 includes image forming units 41Y, 41M, 41C, and 41K, an intermediate transfer unit 42, and an image forming unit 41Y, 41M, 41C, and 41K for forming images with colored toners of Y, M, C, and K components based on input image data. etc.

Image forming units 41Y, 41M, 41C, and 41K for the Y, M, C, and K components have similar configurations. For convenience of illustration and description, common components are denoted by the same reference numerals, and Y, M, C, or K is added to the reference numerals to distinguish them. In FIG. 1, only the components of the image forming unit 41Y for the Y component are denoted by reference numerals, and the components of the other image forming units 41M, 41C, and 41K are omitted.

The image forming unit 41 includes an exposure device 411, a developing device 412, a photosensitive drum 413, a charging device 414, a drum cleaning device 415, and the like.

The photosensitive drum 413 is, for example, an aluminum conductive cylindrical body (aluminum tube) having a drum diameter of 80 [mm], and an undercoat layer (UCL) and a charge generation layer (CGL) on the peripheral surface of the drum. Generation Layer) and a charge transport layer (CTL: Charge Transport Layer) are sequentially laminated to form a negatively charged organic photoreceptor (OPC: Organic Photo-conductor). The charge-generating layer is made of an organic semiconductor in which a charge-generating material (eg, phthalocyanine pigment) is dispersed in a resin binder (eg, polycarbonate), and generates a pair of positive and negative charges when exposed by the exposure device 411 . The charge-transporting layer consists of a hole-transporting material (electron-donating nitrogen-containing compound) dispersed in a resin binder (e.g., polycarbonate resin), and transports positive charges generated in the charge-generating layer to the surface of the charge-transporting layer. do.

The control unit 101 rotates the photoreceptor drum 413 at a constant peripheral speed by controlling the drive current supplied to a drive motor (not shown) that rotates the photoreceptor drum 413 .

The charging device 414 uniformly charges the surface of the photosensitive drum 413 having photoconductivity to a negative polarity. The exposure device 411 is composed of, for example, a semiconductor laser, and irradiates the photosensitive drum 413 with laser light corresponding to an image of each color component. A positive charge is generated in the charge generation layer of the photoreceptor drum 413 and transported to the surface of the charge transport layer, thereby neutralizing the surface charge (negative charge) of the photoreceptor drum 413 . An electrostatic latent image of each color component is formed on the surface of the photosensitive drum 413 due to a potential difference with the surroundings.

The developing device 412 is a two-component developing device that adheres toner of each color component to the surface of the photosensitive drum 413 to visualize the electrostatic latent image and form a toner image.

The drum cleaning device 415 has a drum cleaning blade or the like that slides on the surface of the photoreceptor drum 413, and removes transfer residual toner remaining on the surface of the photoreceptor drum 413 after the primary transfer.

The intermediate transfer unit 42 includes an intermediate transfer belt 421, a primary transfer roller 422, a plurality of support rollers 423, a secondary transfer roller 424, a belt cleaning device 426, and the like.

The intermediate transfer belt 421 is an endless belt and stretched around a plurality of support rollers 423 in a loop. At least one of the plurality of supporting rollers 423 is configured as a driving roller, and the others are configured as driven rollers. For example, it is preferable that the roller 423A arranged downstream in the belt running direction from the primary transfer roller 422 for the K component is a driving roller. This makes it easier to keep the running speed of the belt in the primary transfer portion constant. As the drive roller 423A rotates, the intermediate transfer belt 421 runs in the arrow A direction at a constant speed.

The intermediate transfer belt 421 is a conductive and elastic belt, and has a high-resistance layer with a volume resistivity of 8 to 11 [logΩ·cm] on its surface. Intermediate transfer belt 421 is rotationally driven by a control signal from control unit 101 . The material, thickness and hardness of the intermediate transfer belt 421 are not limited as long as they have conductivity and elasticity.

The primary transfer roller 422 is arranged on the inner circumferential surface side of the intermediate transfer belt 421 so as to face the photosensitive drum 413 of each color component. A primary transfer nip for transferring a toner image from the photosensitive drum 413 to the intermediate transfer belt 421 is formed by pressing the primary transfer roller 422 against the photosensitive drum 413 with the intermediate transfer belt 421 therebetween.

The secondary transfer roller 424 is arranged on the outer peripheral surface side of the intermediate transfer belt 421 so as to face the backup roller 423B arranged on the downstream side of the drive roller 423A in the belt running direction. A secondary transfer nip for transferring the toner image from the intermediate transfer belt 421 to the long paper P or paper S is formed by pressing the secondary transfer roller 424 against the backup roller 423B with the intermediate transfer belt 421 interposed therebetween. be done.

When the intermediate transfer belt 421 passes through the primary transfer nip, the toner images on the photosensitive drum 413 are sequentially superposed on the intermediate transfer belt 421 and primarily transferred. Specifically, a primary transfer bias is applied to the primary transfer roller 422, and a charge opposite to that of the toner is applied to the back side of the intermediate transfer belt 421 (the side that contacts the primary transfer roller 422), thereby forming the toner image. It is electrostatically transferred to the intermediate transfer belt 421 .

After that, the toner image on the intermediate transfer belt 421 is secondarily transferred to the long paper P or the paper S when the long paper P or the paper S passes through the secondary transfer nip. Specifically, a secondary transfer bias is applied to the secondary transfer roller 424, and an electric charge having a polarity opposite to that of the toner is applied to the back side of the long paper P or the paper S (the side in contact with the secondary transfer roller 424). As a result, the toner image is electrostatically transferred to the long paper P or paper S. As shown in FIG. The long paper P or paper S onto which the toner image has been transferred is conveyed toward the fixing section 60 .

A belt cleaning device 426 removes transfer residual toner remaining on the surface of the intermediate transfer belt 421 after secondary transfer. Instead of the secondary transfer roller 424, a configuration in which a secondary transfer belt is stretched in a loop shape around a plurality of support rollers including the secondary transfer roller (a so-called belt-type secondary transfer unit) is adopted. Also good.

The fixing unit 60 includes an upper fixing unit 60A having a fixing surface side member arranged on the fixing surface (the surface on which the toner image is formed) side of the long paper P or the paper S, and the back surface of the long paper P or the paper S. A lower fixing section 60B and the like having a back-side support member arranged on the (surface opposite to the fixing surface) side are provided. A fixing nip for holding and conveying the long paper P or the paper S is formed by pressing the back surface side support member against the fixing surface side member.

The fixing unit 60 fixes the toner image to the long paper P or the paper S by heating and pressurizing the conveyed long paper P or the paper S at the fixing nip after the toner image is secondarily transferred. The fixing section 60 is arranged inside the fixing device F as a unit. Further, the fixing device F may be provided with an air separation unit that separates the long paper P or the paper S from the fixing surface side member or the back side support member by blowing air.

The upper fixing section 60A has an endless fixing belt 61, a heating roller 62, and a fixing roller 63, which are members on the fixing surface side (belt heating method). The fixing belt 61 is stretched between the heating roller 62 and the fixing roller 63 with a predetermined belt tension (for example, 40 [N]).

The fixing belt 61 contacts the long paper P or paper S on which the toner image is formed, and heats and fixes the toner image onto the long paper P or paper S at a fixing temperature (for example, 160 to 200 [° C.]). do. Here, the fixing temperature is a temperature that can supply the amount of heat required to melt the toner on the long paper P or the paper S. different.

The heating roller 62 incorporates a heat source (halogen heater) and heats the fixing belt 61 . The heating roller 62 is heated by the heat source, and as a result, the fixing belt 61 is heated.

The fixing roller 63 has an elastic layer (for example, thickness: 10 [mm]) made of silicone rubber or the like and a surface layer (for example, thickness: 70 [μm]) are stacked in order. Driving control of the fixing roller 63 (for example, turning on/off of rotation, peripheral speed, etc.) is performed by the control unit 101 . Control unit 101 rotates fixing roller 63 clockwise. As fixing roller 63 rotates, fixing belt 61 and heating roller 62 rotate clockwise.

The lower fixing section 60B has a pressure roller 64 as a back side support member (roller pressure method). The pressure roller 64 has a configuration in which an elastic layer made of silicon rubber or the like and a surface layer made of a PFA tube are laminated in order on the outer peripheral surface of a cylindrical core metal made of iron or the like. The pressure roller 64 is pressed against the fixing roller 63 via the fixing belt 61 with a predetermined fixing load (for example, 1000 [N]) by a pressure contact/separation portion (not shown).

The pressing/separating portion has a known configuration, and presses or separates the fixing belt 61 and the pressure roller 64 from each other. In this manner, a fixing nip is formed between the fixing belt 61 and the pressure roller 64 to hold and convey the long paper P or the paper S. As shown in FIG. A control unit 101 controls the driving of the pressure roller 64 (for example, ON/OFF of rotation, peripheral speed, etc.) and the driving control of the pressure contact/separation portion. The controller 101 rotates the pressure roller 64 counterclockwise.

The paper conveying unit 50 includes a paper feeding unit 51, a paper discharging unit 52, a conveying path unit 53, and the like. The three paper feed tray units 51a to 51c that constitute the paper feed unit 51 store paper S (standard paper, special paper) identified based on basis weight, size, etc., for each preset type. . The transport path portion 53 has a plurality of transport roller pairs including a registration roller pair 53a. The registration roller section, in which the registration roller pair 53a is arranged, corrects the inclination and deviation of the paper S or the long paper P. As shown in FIG.

The paper sheets S accommodated in the paper feed tray units 51 a to 51 c are sent out one by one from the top and conveyed to the image forming section 40 by the conveying path section 53 . In the image forming section 40 , the toner images on the intermediate transfer belt 421 are collectively secondary-transferred onto one side of the sheet S, and the fixing section 60 performs a fixing process. Further, the long paper P fed from the paper feeding device 1 to the image forming device 2 is transported to the image forming section 40 by the transport path portion 53 . Then, in the image forming section 40 , the toner images on the intermediate transfer belt 421 are collectively secondary-transferred onto one surface of the long paper P, and the fixing section 60 performs a fixing process. The long paper P or paper S on which an image has been formed is transported to the image reading device 3 by a paper discharge section 52 having a transport roller pair (paper discharge roller pair) 52a.

The image reading device 3 reads an image formed on the long paper P or the paper S ejected from the image forming device 2 to generate image data, compares it with the reference image data, and determines the color, position, and image. Check for errors, creases, etc. The image reading device 3 includes a reading control section 301, an image reading section 302, a temperature detecting section 303, a blowing section 304, and a blowing direction changing section 305, as shown in FIGS. In the following description, a case of reading an image formed on a long paper P (corresponding to the "paper" of the present invention) will be described.

A reading control unit 301 (corresponding to the “control unit”, “mode setting unit”, “temperature setting unit”, and “determining unit” of the present invention) cooperates with the control unit 101 of the image forming apparatus 2 to Controls overall behavior. The reading control unit 301 compares the image data generated based on the reading result of the image reading unit 302 and the reference image data, and inspects the color, position, image error, folding, and the like.

The image reading unit 302 is, for example, a scanner provided with an optical image sensor such as a CCD, a CMOS, etc., provided with a large number of regularly arranged reading elements, and reads an image formed on the long sheet P or the sheet S. It is configured so that the position and density can be read. As shown in FIGS. 3A and 3B, the image reading unit 302 has a strip-shaped reading glass 302a provided along a direction orthogonal to the conveying direction of the long paper P (from right to left in FIGS. 3A and 3B). (Corresponding to the “image reading unit” of the present invention) It reads an image when the long paper P passes over it, generates image data of the read image, and outputs the image data to the reading control unit 301 .

The temperature detection unit 303 is, for example, a temperature detection sensor, detects the temperature of the long paper P, and outputs it to the read control unit 301 . In this embodiment, the temperature detection unit 303 is provided on the opposite side of the long sheet P from the blower unit 304 and near the image reading unit 302 . This is for the purpose of detecting the temperature of the long paper P with high accuracy while eliminating the influence of air blown by the air blower 304 as much as possible. In addition, by providing the temperature detection unit 303 near the image reading unit 302, the temperature change of the long paper P near the image reading unit 302, which causes the phenomenon of thermochromism to be described later, can be detected correctly, and the thermochromism can be detected. It can be utilized for accurate ventilation control to prevent the occurrence of phenomena.

Air blower 304 is long to prevent foreign matter (dust or paper dust) from adhering to reading surface 302b of reading glass 302a and to remove foreign matter from adhering to reading surface 302b. Between the paper P and the image reading unit 302, air is blown from the downstream side to the upstream side of the image reading unit 302 in the conveying direction of the long paper P (see the arrow direction).

The air blowing unit 304 has a heating unit 304a that heats the air blown by the air blowing unit 304 to warm the long paper P that hits the air. For example, the heating unit 304a is composed of a far-infrared heater.

The blowing direction changing unit 305 changes the blowing direction of the blowing unit 304 . In this embodiment, the blowing direction changing unit 305 includes a known moving mechanism (not shown) for moving the blowing unit 304 in the vertical direction in FIG. ) and regulating guides 305a and 305b.

By the way, for example, if the air blowing unit 304 blows air excessively, the temperature of the long paper P changes greatly, and the temperature change causes a thermochromism phenomenon in which the color of the read image changes. When the color of the read image changes due to the thermochromism phenomenon, the image reading unit 302 cannot read the color of the image on the long paper P correctly. It should be noted that the temperature of the long paper P changes greatly between the beginning of printing and after a certain period of time has elapsed from the beginning of printing, and the temperature change causes the thermochromism phenomenon.

Therefore, in the present embodiment, the reading control unit 301 controls the air blowing unit 304 so that the amount of change in the temperature detected by the temperature detecting unit 303 is small, preferably the temperature detected by the temperature detecting unit 303 is constant. Controls the amount of air blown by As a result, it is possible to correctly read the color of the image on the long paper P while preventing foreign matter from adhering to the image reading unit 302 .

In the present embodiment, the reading control unit 301 sets the reading mode of the image reading device 3 according to user's operation on the operation unit 22 of the image forming device 2 . Specifically, the reading control unit 301 sets an image quality priority mode for reading an image with image quality priority or an inspection priority mode for reading an image with inspection priority.

For example, when the image quality priority mode is set by emphasizing the color stability of the read image in real time, the reading control unit 301 controls the air blowing unit so that the amount of change in the temperature detected by the temperature detecting unit 303 is small. 304 to control the amount of air blown. As a result, it is possible to prevent the thermochromism phenomenon, that is, the change in the color of the read image, and to ensure the stability of the color of the read image.

On the other hand, for example, when the inspection priority mode is set with emphasis on detection of image defects, etc., the reading control unit 301 increases the amount of air blown by the air blower 304 compared to when the image quality priority mode is set (for example, the maximum value). The reason for this is that, when a foreign object is attached to the reading surface 302b of the reading glass 302a during inspection for image defects, etc., it is difficult to determine whether it is a foreign object in the read image or a foreign object in the image reading device 3. This is because it is difficult and, in some cases, may impair the reliability of image defect detection. Therefore, when the inspection priority mode is set, the reading control unit 301 is configured to prevent foreign matter from adhering to the reading surface 302b of the reading glass 302a, and to remove foreign matter from adhering to the reading surface 302b. In order to remove it, control is performed so that the amount of air blown by the air blower 304 is increased compared to when the image quality priority mode is set.

Further, when the image reading unit 302 does not perform reading, for example, after execution of a print job is completed, the reading control unit 301 controls the blower unit 304 to operate more efficiently than when the image reading unit 302 performs reading for a predetermined time. Control so that the air flow volume by is increased. This is to remove foreign matter adhering to the reading surface 302b of the reading glass 302a while the image reading unit 302 is not reading in preparation for the next reading.

Further, when the temperature of the long sheet P has decreased too much due to the air blown by the air blower 304 or the temperature environment in the first morning in winter, and the temperature should be raised quickly, the reading control unit 301 warms the long sheet P. , controls the heating unit 304 a of the air blowing unit 304 . Although an example in which the blower section 304 includes the heating section 304a has been described, the blower section 304 and the heating section 304a may be provided separately. In this case, the heating unit 304a may heat the long paper P directly.

Further, the reading control unit 301 sets the temperature designated by the user as the set temperature of the long sheet P according to the user's operation on the operation unit 22 of the image forming apparatus 2 . Then, the reading control unit 301 controls the amount of air blown by the air blowing unit 304 so that the difference between the set temperature and the temperature of the long paper P becomes small. For example, when a print job executed at a certain temperature is executed again at a later date, the temperature of the long paper P changes greatly depending on the execution timing of the print job. This is to prevent the chromism phenomenon from occurring.

Further, the reading control unit 301 refers to the image data generated based on the reading result of the image reading unit 302, and determines whether or not foreign matter is attached to the reading surface 302b of the image reading unit 302 (reading glass 302a). judge. Then, when it is determined that a foreign object is attached to the reading surface 302b, the reading control unit 301 controls the air blowing direction changing unit 305 to blow air toward the reading surface 302b.

In FIG. 3A, when it is not determined that a foreign object is attached to the reading surface 302b, the air blowing direction changing unit 305 is controlled so as to blow air not toward the reading surface 302b but in a direction parallel to the reading surface 302b. showing the situation. On the other hand, FIG. 3B shows how the airflow direction changing unit 305 is controlled to blow air toward the reading surface 302b when it is determined that a foreign object is attached to the reading surface 302b. As a result, it is possible to reliably remove the foreign matter adhering to the reading surface 302b of the reading glass 302a. From the viewpoint of more reliably removing the foreign matter adhering to the reading surface 302b, the reading control unit 301 determines that the foreign matter is not adhering to the reading surface 302b when it is determined that the foreign matter is adhering to the reading surface 302b. Control may be performed so that the amount of air blown by the air blower 304 is increased compared to when it is determined.

The paper discharge device 4 is a device that winds up and stores the long paper P conveyed from the image reading device 3 . In the housing of the paper discharge device 4, for example, as shown in FIG. 1, the long paper P is wound around the support shaft and held in a roll shape. For this reason, the paper discharge device 4 passes the long paper P conveyed from the image forming device 2 through a plurality of pairs of conveying rollers (e.g., delivery rollers, paper discharge rollers), and at a constant speed. to wind up. The winding operation of the paper discharge device 4 is controlled by the control unit 101 provided in the image forming device 2 .

Next, an operation example of the image reading device 3 will be described with reference to FIG. Note that the processing shown in FIG. 4 is executed, for example, during image forming processing corresponding to a print job.

First, the reading control unit 301 acquires the temperature detection result of the long paper P by the temperature detection unit 303 (step S100).

Next, the reading control unit 301 determines whether or not the image quality priority mode is set as the reading mode of the image reading device 3 (step S120). As a result of the determination, if the image quality priority mode is set (step S120, YES), the reading control unit 301 reduces the amount of air blown by the air blowing unit 304 so that the amount of change in the temperature detected by the temperature detecting unit 303 is small. is controlled (step S140). The image reading device 3 ends the process in FIG. 4 by completing the process of step S140.

On the other hand, if the image quality priority mode is not set, that is, if the inspection priority mode is set (step S120, NO), the reading control unit 301 reads the image data generated based on the reading result of the image reading unit 302. Then, it is determined whether or not a foreign object adheres to the reading surface 302b of the image reading unit 302 (reading glass 302a) (step S160). As a result of the determination, if no foreign matter adheres to the reading surface 302b (step S160, NO), the process transitions to step S200.

On the other hand, if a foreign object adheres to the reading surface 302b (step S160, YES), the reading control unit 301 controls the air blow direction changing unit 305 to blow air toward the reading surface 302b (step S180). Thereafter, the process transitions to step S200.

In step S200, the reading control unit 301 performs control so that the amount of air blown by the air blowing unit 304 is increased compared to when the image quality priority mode is set. The image reading device 3 ends the process in FIG. 4 by completing the process of step S200.

As described in detail above, in the present embodiment, the image reading device 3 includes the image reading unit 302 that reads an image formed on the long paper P, and the temperature detection unit 303 that detects the temperature of the long paper P. , an air blowing unit 304 that blows air between the long sheet P and the image reading unit 302, and reading control that controls the amount of air blown by the air blowing unit 304 so that the amount of change in temperature detected by the temperature detection unit 303 is small. and a section 301 .

According to this embodiment configured as described above, by providing the air blowing unit 304 for blowing air between the long sheet P and the image reading unit 302, it is possible to prevent foreign matter from adhering to the image reading unit 302. . Furthermore, since the amount of air blown by the air blower 304 is controlled so that the amount of change in the temperature of the long paper P is small, for example, the air blown by the air blower 304 greatly changes the temperature of the long paper P, causing the temperature to rise. It is possible to prevent the occurrence of the thermochromism phenomenon in which the color of the read image changes due to the change. As described above, it is possible to correctly read the color of the image on the long paper P while preventing foreign matter from adhering to the image reading unit 302 .

In the above embodiment, the image reading device 3 is connected downstream of the image forming device 2 in the transport direction of the long paper P, but the present invention is not limited to this. For example, the image reading device 3 may be provided inside the image forming device 2 .

Moreover, the above-described embodiments are merely examples of specific implementations of the present invention, and the technical scope of the present invention should not be construed to be limited by these. Thus, the invention may be embodied in various forms without departing from its spirit or essential characteristics.

REFERENCE SIGNS LIST 1 paper feeding device 2 image forming device 3 image reading device 4 paper discharging device 10 image reading section 20 operation display section 21 display section 22 operation section 30 image processing section 40 image forming section 50 paper conveying section 60 fixing section 71 communication section 72 storage Unit 100 Image forming system 101 Control unit 102 CPU
103 ROMs
104 RAMs
301 reading control unit 302 image reading unit 302a reading glass 302b reading surface 303 temperature detection unit 304 blowing unit 304a heating unit 305 blowing direction changing unit 305a, 305b regulation guide P long paper

Claims (13)

an image reading unit that reads an image formed on a sheet;
a temperature detection unit that detects the temperature of the paper;
a blowing unit that blows air between the sheet and the image reading unit;
a control unit that controls the amount of air blown by the air blow unit so that the amount of change in the temperature detected by the temperature detection unit is small;
a mode setting unit for setting an image quality priority mode for reading the image with image quality priority or an inspection priority mode for reading the image with inspection priority;
an image reader. an image reading unit that reads an image formed on a sheet;
a temperature detection unit that detects the temperature of the paper;
a blowing unit that blows air between the sheet and the image reading unit;
a control unit that controls the amount of air blown by the air blow unit so that the amount of change in the temperature detected by the temperature detection unit is small;
with
The temperature detection unit is provided on the opposite side of the air blow unit across the paper,
Image reader. an image reading unit that reads an image formed on a sheet;
a temperature detection unit that detects the temperature of the paper;
a blowing unit that blows air between the sheet and the image reading unit;
a control unit that controls the amount of air blown by the air blow unit so that the amount of change in the temperature detected by the temperature detection unit is small;
a blowing direction changing unit that changes the blowing direction of the blowing unit;
a determination unit that determines whether or not a foreign object adheres to the reading surface of the image reading unit;
with
When it is determined that a foreign object is attached to the reading surface, the control unit controls the air blow direction changing unit to blow air toward the reading surface.
Image reader. When the inspection priority mode is set, the control unit controls to increase the amount of air blown by the blower unit compared to when the image quality priority mode is set.
The image reading device according to claim 1 . The temperature detection unit is provided on the opposite side of the air blow unit across the paper,
The image reading device according to claim 1 . The temperature detection unit is provided near the image reading unit,
6. The image reading device according to claim 5 . The air blowing unit blows air from the downstream side to the upstream side of the image reading unit in the paper transport direction.
The image reading device according to any one of claims 1 to 6 . When the image reading unit does not perform reading, the control unit controls the amount of air blown by the air blowing unit to increase compared to when the image reading unit performs reading.
The image reading device according to any one of claims 1 to 7 . A heating unit that warms the paper,
The image reading device according to any one of claims 1 to 8 . The blower unit has the heating unit,
The image reading device according to claim 9 . A temperature setting unit that sets a temperature specified by a user as a set temperature of the paper,
The control unit controls the amount of air blown by the air blow unit so that the difference between the set temperature and the temperature of the paper becomes small.
The image reading device according to any one of claims 1 to 10 . When it is determined that a foreign object is attached to the reading surface, the control unit increases the amount of air blown by the air blowing unit compared to when it is determined that the foreign object is not attached to the reading surface. Control,
4. The image reading device according to claim 3 . An image forming system comprising the image reading device according to any one of claims 1 to 12.

Images