JP6384478B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  2. Description of the Related Art An image forming apparatus is known that includes an irradiation unit that irradiates a recording medium on which an image is formed with an energy such as ultraviolet rays in order to fix a colorant such as ink ejected onto the recording medium when the image is formed. (For example, patent document 1).

  There is also known an image forming apparatus including a reading unit that optically reads an image formed on a recording medium before discharging the recording medium. Such an image forming apparatus has, for example, a function of reading a color chart formed on a recording medium by a reading unit and determining color reproducibility of an image based on a reading result.

JP 2009-262524 A

  However, in an image forming apparatus including an irradiation unit and a reading unit, when ultraviolet rays or the like irradiated by the irradiation unit enters the reading unit, there is a problem that an error is caused in a reading result of the reading unit. Here, since both the irradiation unit and the reading unit are provided so as to face the recording medium conveyed by the conveyance unit, it is difficult to completely physically separate the irradiation unit and the reading unit.

  An object of the present invention is to provide an image forming apparatus that can further reduce the influence of energy applied to a recording medium by an irradiation unit on a reading result of the reading unit.

The image forming apparatus according to a first aspect of the present invention, an image forming unit for forming an image on a recording medium, wherein the image forming unit the image is formed, a recording medium conveyed is placed on a predetermined conveying surface an irradiation unit that irradiates the energy for fixing the image to a reading unit reading the image fixed on the recording medium conveyed is placed on the conveying surface, and the reading unit at least the irradiating portion A shielding unit that blocks a part of the energy irradiated from the irradiation unit, and a positional relationship between the irradiation unit and the reading unit is an irradiation range in which the recording medium is irradiated with energy by the irradiation unit. The positional relationship is such that the reading position where the reading unit reads the recording medium does not overlap, and the irradiation unit irradiates the energy by irradiating light, and the positional relationship is irradiated from the irradiation unit. Positional relationship in which the absolute value of the intensity of the light entering the reading unit is less than or equal to the magnitude of the light intensity difference corresponding to the minimum gradation difference detectable by the reading unit in reading the image der is, the shielding unit, and an end portion of the conveying surface has a extending portion which extends along the conveying surface.

  According to the present invention, it is possible to further reduce the influence of the energy applied to the recording medium by the irradiation unit on the reading result by the reading unit.

1 is a diagram illustrating a main configuration of an image forming system according to an embodiment of the present invention. 1 is a block diagram illustrating a main configuration according to an image forming system. It is a figure which shows the example of a change of the conditions which concern on the discharge of the ink from a nozzle, and is a figure which shows an example of the discharge condition of the ink in which a missing part exists. It is a figure which shows the example of a change of the conditions which concern on the discharge of the ink from a nozzle, and is a figure which shows an example of the discharge condition of the ink by which conditions were changed so that a missing part might be compensated. It is a figure which shows an example of the specific structure of an irradiation part. It is a figure which shows an example of the correspondence of the wavelength of the light emitted from the light source of an irradiation part, the integrated light quantity required for hardening of four colors of ink, and the illumination intensity of the light emitted from the said light source. It is a figure which shows an example of the spectral sensitivity characteristic of the CCD image sensor of a reading part. It is a figure which shows an example of the positional relationship of a drum, an image formation part, an irradiation part, and a reading part, and is a figure which concerns on description of a predetermined irradiation area | region and a deceleration area | region. It is a figure which shows an example of the positional relationship of a drum, an image formation part, an irradiation part, and a reading part, and is a figure which concerns on description of the distance of the intersection of a center line and the outer peripheral surface of a drum, and the reading position by a reading part. It is a graph which shows the relationship between the position of the reading part with respect to a centerline, and the intensity | strength of the ultraviolet-ray which approachs a CCD image sensor in the case of reading by a reading part in case there exists a shielding part. 6 is a graph showing the relationship between the position of the reading unit with respect to the center line and the intensity of ultraviolet rays that enter the CCD image sensor during reading by the reading unit when there is no shielding unit. It is a figure which shows an example of a test chart. It is a figure which shows an example of a positional relationship adjustment image. It is a figure which shows an example of the formation position of a pattern image. It is a figure which shows the example of a production | generation of synthetic | combination image data. It is a figure which shows an example of a shading image. The figure which shows the example in which formation of a pattern image is completed before the downstream edge part reaches | attains the reading position by a reading part among the edge parts of the direction along the conveyance direction of the pattern image currently formed in the recording medium. It is. It is a figure which shows an example in which the formation position of a pattern image does not overlap on both surfaces. It is a figure which shows an example of the composite image data in which the blank part was provided. It is a block diagram which shows the main structures concerning the image forming system further provided with a comparison part.

  Embodiments of the present invention will be described below with reference to the drawings. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

FIG. 1 is a diagram illustrating a main configuration of an image forming system 1 including an image forming apparatus according to an embodiment of the present invention.
The image forming system 1 includes a supply unit 10, a main body unit 100, and a discharge unit 20. The supply unit 10, the main body unit 100, and the discharge unit 20 are provided and connected along a predetermined direction (the X direction shown in FIG. 1).

  The supply unit 10 stores a recording medium P (for example, paper) on which an image is formed by the image forming unit 120 provided in the main body unit 100 and supplies the recording medium P to the main body unit 100 one by one.

  The main body 100 forms an image on the recording medium P supplied from the supply unit 10 and discharges the recording medium P on which the image is formed to the discharge unit 20.

  The main body 100 includes a transport unit 110 that transports the recording medium P, an image forming unit 120 that forms an image on the recording medium P, an irradiation unit 130 that irradiates the recording medium P on which an image is formed by the image forming unit 120, A reading unit 140 that reads a medium conveyed to the conveyance unit 110 is provided, and functions as an image forming apparatus in the image forming system 1.

The transport unit 110 transports the medium to the image forming unit 120, the irradiation unit 130, and the reading unit 140.
Specifically, the transport unit 110 includes, for example, a cylindrical drum 110a. The drum 110a is provided so as to be rotatable about an axis passing through the circular center of the cylinder, and carries the recording medium P on the cylindrical outer peripheral surface of the drum 110a. The conveyance unit 110 conveys one surface of the recording medium P carried on the outer peripheral surface while facing the image forming unit 120, the irradiation unit 130, and the reading unit 140 by rotating the drum 110a.
The image forming unit 120, the irradiation unit 130, and the reading unit 140 are provided along the outer peripheral surface in the vicinity of the position where the outer peripheral surface of the rotating drum 110a passes. Specifically, as illustrated in FIG. 1, the image forming unit 120, the irradiation unit 130, and the reading unit 140 are supplied from the supply unit 10 in a conveyance path along which the recording medium P is conveyed by passing through the outer peripheral surface of the drum 110 a. The image forming unit 120, the irradiation unit 130, and the reading unit 140 are provided in this order from the upstream side to the downstream side along the conveyance path for conveying the supplied recording medium P to the discharge unit 20 side.

  Further, the transport unit 110 includes a detection unit 110b that detects the rotation angle of the drum 110a, and a recording medium that is carried and transported on the outer peripheral surface of the drum 110a based on the rotation angle of the drum 110a detected by the detection unit 110b. It is provided so that the position of P can be detected. The detection unit 110b is, for example, an encoder provided on the rotation shaft of the drum 110a. However, the detection unit 110b is an example and is not limited to this, and may be any configuration that can detect the rotation angle of the drum 110a.

Further, the transport unit 110 has a mechanism for inverting the front and back of the recording medium P.
Specifically, the transport unit 110 includes, for example, a switchback unit 115. The switchback unit 115 reverses and conveys the recording medium P by switchback.

More specifically, the switchback unit 115 includes, for example, two cylinders (first cylinder 115a and second cylinder 115b) and a pair of belt loops (belt loop 115c) shown in FIG.
The recording medium P is transferred from the drum 110a to the first cylinder 115a that rotates counterclockwise in FIG. 1 through the cylinder 111 that rotates clockwise in FIG. 1, and then rotates in the clockwise direction in FIG. It is delivered to the two cylinders 115b. When the rear end of the recording medium P reaches the nip portion of the belt loop 115c that rotates counterclockwise in FIG. 1 with the second cylinder 115b, the belt loop 115c reverses in the clockwise direction in FIG. To the drum 110a. Here, the recording medium P returned to the drum 110a by the belt loop 115c is again carried on the drum 110a in a state where the surface on which the image is formed abuts on the outer peripheral surface of the drum 110a. That is, the recording medium P is turned over by the switchback unit 115. Further, the leading end along the conveyance direction of the recording medium P returned to the drum 110a is the end on the trailing side when the recording medium P is conveyed by the drum 110a before being returned. That is, the recording medium P is turned over by being conveyed by the switchback unit 115 so as to be reversed.
In this way, the transport unit 110 can transport the recording medium P such that the both surfaces of the recording medium P and the like are sequentially opposed to the image forming unit 120 by reversing and transporting the recording medium P by the switchback unit 115. Is provided.

The position where the first cylinder 115a of the switchback unit 115 takes over the conveyance of the recording medium P from the drum 110a is downstream of the irradiation unit 130 in the conveyance direction of the recording medium P. Further, when the belt loop 115c returns the recording medium P to the drum 110a, the returned recording medium P is conveyed again to the image forming unit 120 from the upstream side of the image forming unit 120.
Thus, when the image forming unit 120 forms images on both sides of the recording medium P, the switchback unit 115 reverses the front and back of the recording medium P on which the image is formed on one side, It functions as a reversing unit that transports the recording medium P to the upstream side of the image forming unit 120 in the transport direction 110.
The reading unit 140 is provided on the downstream side of the image forming unit 120 in the transport direction and on the upstream side of the switchback unit 115. Therefore, the switchback unit 115 conveys the recording medium P conveyed by the conveyance unit 110 through the image forming unit 120 and the reading unit 140 to the upstream side of the reading unit 140 in the conveyance direction of the conveyance unit 110. Then, it functions as a re-conveying unit that conveys the conveying unit 110 again.

The image forming unit 120 forms an image on the recording medium P.
Specifically, the image forming unit 120 includes, for example, a head unit 121 provided with a plurality of recording heads H provided with nozzles for ejecting ink onto the recording medium P carried on the drum 110a. The head unit 121 is provided individually for each color of ink ejected onto the recording medium P (for example, four colors of cyan (C), magenta (M), yellow (Y), and black (K)). The image forming unit 120 having such a head unit 121 forms an image on the recording medium P by ejecting ink.

The irradiation unit 130 irradiates energy for fixing the image on the recording medium P on which the image is formed by the image forming unit 120.
The energy irradiated by the irradiation unit 130 depends on the ink characteristics. For example, when ultraviolet curable ink that is cured by ultraviolet irradiation is used in the head unit 121 of the image forming unit 120, the energy irradiated from the irradiation unit 130 is ultraviolet. In this case, for example, the irradiation unit 130 sets a predetermined range of the light source 131 such as a light emitting diode (LED) that emits ultraviolet (UV) and the range irradiated with the ultraviolet light emitted from the light source 131 (irradiation range). The shielding part 132 etc. which are the irradiation area A (see FIG. 7A). Here, the predetermined irradiation area A is an area in a path through which the outer peripheral surface of the drum 110 a of the transport unit 110 carries the recording medium P and passes. The irradiation unit 130 irradiates the recording medium P conveyed by the conveyance unit 110 and passing through the predetermined irradiation area A with ultraviolet rays.
When energy is irradiated by the irradiation unit 130, the ink ejected on the recording surface of the recording medium P is cured and fixed on the recording surface. As described above, the irradiation unit 130 functions as a fixing unit that fixes an image on the recording medium P on which the image is formed by the image forming unit 120.

The reading unit 140 reads the medium transported to the transport unit 110.
Specifically, the reading unit 140 includes, for example, an imaging element such as a charge-coupled device (CCD) image sensor, illumination that illuminates the recording medium P, and a lens provided on the ray between the imaging element and the recording medium P. Then, the reflected light from the recording medium P illuminated by the illumination is detected by the image sensor, and an electric signal corresponding to the detection result is output. Based on the electrical signal output from the image sensor of the reading unit 140, data corresponding to the reading result is generated and processed as the reading result.

  The discharge unit 20 causes the recording medium P to stand by until the recording medium P discharged from the drum 110a of the main body unit 100 via the cylinder 111, the belt loop 112, and the discharge switching guide 113 is collected by the user. The control unit 250 controls whether the recording medium P is discharged to the discharge unit 20 via the cylinder 111 or conveyed to the switchback unit 115.

Further, the image forming system 1 may be provided with a conveyance path for allowing correction media related to various corrections to pass through the main body 100.
Specifically, for example, as illustrated in FIG. 1, the supply unit 10 includes a correction medium supply tray that is provided separately from the tray that stores the recording medium P and supplies the correction medium. Also good. The discharge unit 20 may include a sub-tray 20b for discharging the correction medium, which is provided separately from the main tray 20a for waiting the recording medium P. The control unit 250 controls the discharge switching guide 113 to switch whether the recording medium P is discharged to the main tray 20a or the sub-tray 20b.
As described above, the image forming system 1 is provided so that various media (for example, a correction medium) including the recording medium P can be conveyed and read by the reading unit 140.
The medium may be a sheet having a size that can be conveyed by the conveyance unit 110. Of the size of the medium, the size in the direction along the transport direction depends on, for example, the circumferential length of the drum 110a. Further, the size of the medium in the width direction orthogonal to the transport direction depends on, for example, the width of the outer peripheral surface of the drum 110a (the width in the direction along the central axis of the cylinder of the drum 110a).

FIG. 2 is a block diagram illustrating the main configuration of the image forming system 1.
The image forming system 1 includes, for example, a setting unit 210, an acquisition unit 220, a generation unit 230, a change unit 240, a control unit 250, a display unit 260, and the like in the main body unit 100.

The setting unit 210 includes input devices such as buttons, keys, and a touch panel used for input for various settings related to the operation of the image forming system 1, and corresponds to setting contents corresponding to user operations on the input devices. To the control unit 250.
Specifically, for example, the setting unit 210 outputs a signal for setting whether to form an image by the image forming unit 120 on one side or both sides of the recording medium P in accordance with a user operation. Output to.

The acquisition unit 220 acquires data that is the basis of an image formed by the image forming unit 120.
Specifically, the acquisition unit 220 includes a configuration related to communication such as a network interface card (NIC), for example, and a print job transmitted from an external device such as a PC connected via the communication. To get. The print job includes image data corresponding to the image formed by the image forming unit 120.

The generation unit 230 generates composite image data in which an image (for example, an image corresponding to image data included in a print job) and a pattern image Q formed on the recording medium P together with the image are combined (FIG. 12). reference). The pattern image Q is an image that is formed in the margin of the recording medium P on which the image is formed and is used for adjustment of the image forming unit 120.
Specifically, the generation unit 230 is, for example, an integrated circuit such as a programmable logic device (PLD) such as an FPGA (Field-Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit) or a combination thereof. It consists of a circuit. The generation unit 230 includes a processing unit and a storage device (memory) mounted on the circuit, stores image data included in the print job and image data corresponding to the pattern image Q stored in advance in a memory, Composite image data is generated by the operation of the processing unit.

The changing unit 240 changes a condition relating to image formation by the image forming unit 120 based on the reading result by the reading unit 140.
Specifically, the changing unit 240 includes, for example, an integrated circuit such as a PLD or an ASIC, or a combination thereof, and the conditions related to image formation are determined by the cooperation of the processing unit and the storage device mounted on the circuit. Processing is performed.
For example, when the clogging of any nozzle of the recording head H provided in the head unit 121 is detected based on the result of reading the test chart (see FIG. 9) by the reading unit 140, the conditions for image formation are satisfied. Of these, the conditions relating to the ejection of ink from the nozzles are changed so as to take into account that no ink is ejected from the nozzles that are clogged.
Specifically, for example, as illustrated in FIGS. 3A and 3B, the changing unit 240 uses the ink of the dots D that are ejected around the defective portion E where ink is not ejected due to nozzle clogging. In order to compensate for E, the conditions relating to the ejection of ink from the nozzles are changed. More specifically, the missing portion E is compensated for as shown in FIG. 3B by increasing the amount of ink of the dots D ejected around the missing portion E shown in FIG. 3A. Thereby, the influence which the missing part E has on the image quality can be reduced.
As described above, the conditions relating to image formation changed by the changing unit 240 include conditions relating to ejection of ink from the nozzles.

An example of changing the conditions for covering the defective portion E with the ink discharged around the defective portion E is a change in the drive signal of the nozzle that discharges the ink discharged around the defective portion E.
As another example, there is a change by correction of color values of a pixel corresponding to the missing portion E in the image data which is the original data for determining the nozzle driving condition, and pixels around the pixel. In this case, the missing portion E is covered by increasing the amount of ink ejected by correcting the color value.

The control unit 250 controls the operation of each unit of the image forming system 1.
Specifically, the control unit 250 includes, for example, a CPU, a RAM, a ROM, and the like.
The CPU reads and executes various programs, data, and the like corresponding to the processing contents from a storage device such as a ROM, and controls the operation of each unit of the image forming system 1 according to the executed processing contents. The RAM temporarily stores various programs and data processed by the CPU. The ROM stores various programs and data read by the CPU or the like.

The display unit 260 performs various displays related to the operation of the image forming system 1 under the control of the control unit 250.
Specifically, the display unit 260 includes, for example, a display device such as a liquid crystal display provided integrally with an input device for performing input in a touch panel format, and performs various displays using the display device. The liquid crystal display is merely an example of a display device, and may be another display device (for example, an organic EL (Electroluminescence) display).
The display unit 260 performs display related to the setting by the setting unit 210, for example. Specifically, a display screen for selecting a surface (one side or both sides) on which an image is to be formed depends on the setting of whether the image forming unit 120 forms an image on one side or both sides of the recording medium P. indicate. When the user performs an operation on the setting unit 210 according to the selection of one side or both sides according to the display, the setting unit 210 performs image formation by the image forming unit 120 on one side of the recording medium P or A signal for setting which of the two sides is to be performed is output to the control unit 250.

Hereinafter, more detailed features of the image forming system 1 will be sequentially described.
First, the conveyance by the conveyance unit 110 when the both sides of the medium are read by the reading unit 140 and the operation of the reading unit 140 will be described.
First, the medium is carried by the drum 110a with one surface (front surface) of the medium facing the reading unit 140, and is conveyed from the upstream side to the downstream side of the reading unit 140 in the medium conveyance direction. Accordingly, the reading unit 140 reads one surface of the medium that has passed the reading position SC (see FIG. 7A and the like).
The medium conveyed to the downstream side of the reading unit 140 is switched back and conveyed by the switchback unit 115. As a result, the medium is carried by the drum 110 a with the other surface (back surface) facing the reading unit 140 and is positioned on the upstream side of the reading unit 140 again. Thereafter, the medium is transported again from the upstream side to the downstream side of the reading unit 140 in the medium transport direction. Accordingly, the reading unit 140 reads the other surface of the medium that has passed the reading position SC.
Thus, both sides of the medium can be read by the reading unit 140 provided to read one side of the medium.

Next, the irradiation unit 130 will be described in more detail.
FIG. 4 is a diagram illustrating an example of a specific configuration of the irradiation unit 130.
In addition to the light source 131 and the shielding unit 132 described above, the irradiation unit 130 is supplied with a connector 133 to which a power line for supplying power to the light source 131 is connected, and cooling water for cooling the light source 131. A water cooling port 134 is provided.

The shielding part 132 is provided, for example, so as to extend from the side part of the casing of the light source 131 toward the outer peripheral surface side of the drum 110a of the transport part 110. Further, the shielding part 132 is provided so as to be divergent at a predetermined angle from the light source 131 toward the outer peripheral surface of the drum 110a in the direction along the conveyance direction of the recording medium P by the drum 110a of the conveyance part 110.
Specifically, the shielding part 132 is provided at an angle of 19.4 [°] with respect to the center line CL connecting the center of the generation region where light is emitted from the light source 131 and the rotation center of the drum 110a. Further, the shielding portion 132 of the present embodiment is configured by an aluminum plate provided so as to reflect 98% of the ultraviolet rays emitted from the light source 131 inside a bulky portion provided in a divergent shape. These specific items related to the specific configuration of the shielding part 132 are merely examples, and are not limited to these. Various specific design items such as a predetermined angle, material, and reflectance can be changed as appropriate. It is.

As shown in FIG. 4, if there is no shielding part 132, the irradiation angle FL of the ultraviolet rays emitted from the light source 131 in the direction along the conveyance direction of the recording medium P by the drum 110a of the conveyance unit 110 is relative to the center line CL. Thus, the light source 131 spreads from the light source 131 toward the drum 110a at an angle exceeding 19.4 [°]. The shielding unit 132 extends from the light source 131 to block the ultraviolet rays, and a position where a part of the ultraviolet rays is not intended in the direction along the conveyance direction of the recording medium P by the drum 110a of the conveyance unit 110 (for example, the reading unit 140). And the area irradiated with ultraviolet rays (irradiation range) is defined as a predetermined irradiation area A.
As described above, the shielding unit 132 blocks part of the energy irradiated from the irradiation unit 130 between the irradiation unit 130 and the reading unit 140.

Further, as shown in FIG. 4, the shielding portion 132 may include an extending portion 132 a that is extended so that the end portion on the drum 110 a side substantially follows the outer peripheral surface of the drum 110 a.
The extending portion 132a is provided such that the surface on the drum 110a side does not easily reflect light (such as ultraviolet rays) from the light source 131. Specifically, the extended portion 132a has, for example, a non-reflective material attached to the surface on the drum 110a side. Thereby, the extending part 132a reduces the reflection of light between the recording medium P carried on the drum 110a and the extending part 132a, and reduces the intensity of the light guided in the direction away from the center line CL. Let

Next, a relationship between light (ultraviolet rays) that is energy irradiated by the irradiation unit 130 in the present embodiment and the curing characteristics of the ink used by the image forming unit 120 in the present embodiment will be described.
FIG. 5 is a diagram illustrating an example of a correspondence relationship between the wavelength of light emitted from the light source 131 of the irradiation unit 130, the integrated light amount necessary for curing the four colors of ink, and the illuminance of light emitted from the light source 131. . FIG. 5 is also a diagram illustrating an example of numerical conditions relating to the degree of ultraviolet irradiation in the present embodiment.
In order to reliably cure the four color inks that are ejected onto the recording medium P carried and conveyed by the drum 110a to form the image, the recording medium P is irradiated with light (ultraviolet rays) by the irradiation unit 130. While passing through the predetermined irradiation area A, there is a condition that ultraviolet rays corresponding to the integrated light amount shown in FIG. 5 need to be irradiated according to the wavelength of light. For example, when the wavelength of light is 395 [nm], the necessary integrated light amount is 350 [mJ / cm ² ]. In addition, when the light wavelength is 405 [nm], the necessary integrated light amount is 475 [mJ / cm ² ]. In general, the shorter the wavelength, the smaller the integrated light amount.
The intensity (for example, light wavelength and illuminance) of the ultraviolet rays irradiated by the irradiation unit 130 is set based on the above conditions. For example, the conveyance speed of the recording medium P carried and conveyed by the drum 110a is 850 [mm / sec], and the length in the direction along the conveyance direction of the recording medium P by the drum 110a in the predetermined irradiation area A is 68 [mm. ], The correspondence between the wavelength of light and the illuminance as shown in FIG. 5 is set. Specifically, for example, when the wavelength of light emitted from the light source 131 is 395 [nm], the illuminance is set to 3.0 [W / cm ² ]. When the wavelength is 405 [nm], the illuminance is set to 4.0 [W / cm ² ]. Note that the illuminance of light shown in FIG. 5 is a measurement result obtained when measurement is performed with a dedicated illuminometer at a distance of 10 [mm] from the light generation source by the light source 131, and such measurement result is obtained. Thus, the operating condition of the light source 131 is set.

Next, the relationship between the ultraviolet rays that are the energy irradiated by the irradiation unit 130 in the present embodiment and the detection of light related to reading by the reading unit 140 will be described.
FIG. 6 is a diagram illustrating an example of spectral sensitivity characteristics of the CCD image sensor of the reading unit 140.
As shown in FIG. 6, the CCD image sensor has sensitivity to light having a wavelength of 400 to 700 [nm]. For this reason, for example, when the wavelength of light emitted from the light source 131 of the irradiation unit 130 is 405 [nm], the CCD image sensor has sensitivity to light emitted from the light source 131 of the irradiation unit 130 and reflected light of the light. It will have.
Although not shown in FIG. 6, the CCD image sensor is not completely insensitive to all light of less than 400 [nm] such as 395 [nm]. Further, the wavelength of light set in the light source 131 is only the center wavelength, and the wavelength of the light actually emitted from the light source 131 is not a complete single wavelength. For this reason, even if the wavelength of light emitted from the light source 131 of the irradiation unit 130 is set to be less than 400 [nm], the CCD image sensor can detect the light emitted from the light source 131 of the irradiation unit 130 or the light. May show sensitivity to reflected light.
If the light emitted from the irradiation unit 130 enters the CCD image sensor during the reading operation of the reading unit 140 and the light entering the CCD image sensor has a predetermined intensity or more, the detection result by the CCD image sensor is affected. May give. Specifically, for example, in the case where ultraviolet rays are irradiated from the irradiation unit 130 as in the present embodiment, when the light irradiated from the irradiation unit 130 enters the CCD image sensor during the reading operation of the reading unit 140, There may be a deviation in the detection results relating to purple and blue colors detected by light having a wavelength closer to that of ultraviolet rays.

In addition, the reach distance of the light emitted from the light source 131 also varies depending on whether or not the recording medium P irradiated with the light is processed.
For example, gloss processing is known as one of the processing processes of the recording medium P, and a paper on which gloss processing has been performed is called glossy paper. In particular, it shows a property that the light irradiated on the recording surface is reflected more strongly in a specific direction than glossy paper having a relatively low gloss. For this reason, when high gloss paper is used as the recording medium P, the light emitted from the irradiation unit 130 is more strongly reflected by the recording medium P and can reach other configurations (for example, the reading unit 140). The sex will go up relatively.
In addition, a fluorescent whitening agent may be used for the purpose of enhancing the whiteness of the recording surface of the recording medium P. Since the recording surface whose whiteness has been strengthened by the fluorescent whitening agent reflects light more strongly, when the fluorescent whitening agent is used for the recording medium P, the light emitted from the irradiation unit 130 Is more strongly reflected by the recording medium P, and the possibility of reaching another configuration (for example, the reading unit 140) is relatively increased.

For these reasons, in order to maintain the reading accuracy of the reading unit 140, the irradiation unit so that the energy (for example, light such as ultraviolet rays) irradiated from the irradiation unit 130 does not affect the reading of the image by the reading unit 140. 130 and the reading unit 140 need to be provided. For this reason, the positional relationship between the irradiation unit 130 and the reading unit 140 is such that the irradiation range where the recording medium P is irradiated with energy by the irradiation unit 130 and the reading position SC where the reading unit 140 reads the recording medium P overlap. It becomes a positional relationship that should not be. Furthermore, the positional relationship between the irradiation unit 130 and the reading unit 140 in the present embodiment is that the intensity of light entering the reading position SC when the image is read by the reading unit 140 among the light irradiated from the irradiation unit 130 is as follows. The positional relationship is less than or equal to the light intensity (for example, 0.4 [%]) necessary for detecting the gradation difference of the image read by the reading unit 140.
In relation to the positional relationship between the irradiation unit 130 and the reading unit 140, as an example, the CCD image sensor has 8 bits for each of red (R), green (G), and blue (B), that is, a numerical value of 0 to 255. A case will be described in which the 256 gradations shown in FIG.
The 8-bit CCD image sensor identifies up to 256 gradations as a detection result corresponding to the intensity of light of each color. Here, when no light is detected (detection result: 0), the intensity is 0 [%], and when the strongest light is detected (detection result: 255), the intensity is 100 [%]. The difference in the light intensity when a difference of one gradation occurs is about 0.4 [%] (0.392... [%]). Therefore, when the reading unit 140 is provided with an 8-bit CCD image sensor, the intensity of light entering the reading unit 140 when the reading unit 140 reads an image out of the light irradiated from the irradiation unit 130 is as follows. If the intensity of light used for reading by the reading unit 140 (for example, light emitted by illumination and reflected by the recording medium P to reach the CCD image sensor) is 0.4 [%] or less, substantially. In other words, the light emitted from the irradiation unit 130 does not affect the reading of the image by the reading unit 140. In other words, in the case of an 8-bit CCD image sensor, the light intensity required to detect the gradation difference of the image read by the reading unit 140 is 0 with respect to the light intensity used for reading by the reading unit 140. The strength exceeds 4%.

  Similarly, in the case of a 10-bit CCD image sensor, of the light emitted from the irradiation unit 130, the intensity of light allowed as the intensity of light entering the reading unit 140 when the reading unit 140 reads an image is: The intensity of light used for reading by the reading unit 140 may be 0.1 [%] (0.0976... [%]) Or less. In the case of a 12-bit CCD image sensor, the intensity of light that is allowed as the intensity of light entering the reading unit 140 when the reading unit 140 reads an image out of the light emitted from the irradiation unit 130 is read. It may be 0.02 [%] (0.024... [%]) Or less with respect to the light intensity used for reading by the unit 140.

  Therefore, in the image forming system 1 of the present embodiment, the irradiation unit 130 in which the irradiation range where the recording medium P is irradiated with energy by the irradiation unit 130 and the reading position SC where the reading unit 140 reads the recording medium P does not overlap. Therefore, the energy irradiated from the irradiation unit 130 does not affect the reading of the image by the reading unit 140. Specifically, in the image forming system 1 of the present embodiment, the intensity of light that may enter the reading unit 140 having an 8-bit CCD image sensor out of the light irradiated from the irradiation unit 130. The positional relationship between the irradiation unit 130 and the reading unit 140 is 0.4% or less with respect to the intensity of light used for reading by the reading unit 140 (light by illumination).

7A and 7B are diagrams illustrating an example of a positional relationship among the drum 110a, the image forming unit 120, the irradiation unit 130, and the reading unit 140. FIG. 7A is a diagram relating to a description of a predetermined irradiation area A and deceleration area SL. FIG. 7B is a diagram relating to the description of the distance F between the intersection of the center line CL and the outer peripheral surface of the drum 110a and the reading position SC by the reading unit 140.
8A and 8B are graphs showing the relationship between the position of the reading unit 140 with respect to the center line CL and the intensity of ultraviolet rays that enter the CCD image sensor during reading by the reading unit 140. FIG. 8A is a graph in the case where the shielding part 132 is present. FIG. 8B is a graph when the shielding part 132 is not provided. 8A and 8B corresponds to the distance F. In FIG.
As shown in FIG. 8A, in the case where there is the shielding part 132, by taking a distance F of 70 [mm] or more, the CCD image sensor is used for reading by the reading unit 140 as compared with the distance F of less than 70 [mm]. The intensity of the entering ultraviolet ray is drastically reduced, and by setting the distance F to exceed 100 [mm], the intensity of the ultraviolet ray entering the CCD image sensor upon reading by the reading unit 140 is substantially 0 [%]. be able to.
Further, when there is no shielding part 132 and the light from the irradiation part 130 is not reflected by the drum 110a or the recording medium P, as shown in FIG. Although the attenuation of the intensity of the ultraviolet rays when the distance F is reached does not occur, the distance F exceeding 140 [mm] substantially reduces the intensity of the ultraviolet rays entering the CCD image sensor upon reading by the reading unit 140 to 0. [%].
Here, when the light from the irradiation unit 130 is reflected by the drum 110a or the recording medium P, the reflected light enters the reading unit 140, and therefore it must be installed at a farther distance than shown in FIG. 8B. I must.

  In this embodiment, regarding the positional relationship between the irradiation unit 130 and the reading unit 140, the distance F between the intersection of the center line CL and the outer peripheral surface of the drum 110a and the reading position SC by the reading unit 140 is set to 157 [mm]. The irradiation range where the recording medium P is irradiated with energy by the irradiation unit 130 and the reading position SC where the reading unit 140 reads the recording medium P do not overlap, and the energy irradiated from the irradiation unit 130 is the reading unit 140. The positional relationship that does not affect the reading of the image is established.

  Of the light emitted from the irradiation unit 130, the intensity of the light entering the reading unit 140 when the reading unit 140 reads the image is the processing applied to the recording medium P used in the image forming system 1. Among these, it is desirable to measure based on the case where the recording medium P that has been processed so that the light irradiated from the irradiation unit 130 is reflected most strongly is transported to the transport unit 110.

  The position of the irradiation unit 130 relative to the drum 110a is the recording medium P in which the configuration of the irradiation unit 130 (for example, the extended portion 132a at the end of the shielding unit 132 on the drum 110a side) is carried on the drum 110a. It is preferable that the position is as close as possible to the drum 110a within a range that does not hinder the conveyance of the drum 110a. Thereby, it can suppress more that energy, such as light, reaches | attains another structure from the clearance gap between the irradiation part 130 and the drum 110a.

Next, the formation of the pattern image Q by the image forming unit 120 will be described.
Specifically, as the pattern image Q, for example, a test chart (see FIG. 9) for detecting whether or not the nozzles of the recording head H provided in the head unit 121 are clogged, a plurality of patterns provided in the head unit 121 are used. For example, a positional relationship adjustment image (see FIG. 10) for confirming the positional relationship between the recording heads H can be used.

  For example, as shown in FIG. 9, the test chart includes a line having a predetermined length along the conveyance direction of the recording medium P, which is formed by ejecting ink from each of the nozzles. Here, the number of lines having a predetermined length corresponds to the number of nozzles. If there are nozzles that are clogged, abnormalities such as defects and blurring will appear due to the formation of lines corresponding to the nozzles that are clogged. The presence or absence can be detected.

For example, as shown in the patterns Pa and Pb in FIG. 10, the positional relationship adjusted image overlaps at least in the direction along the conveyance direction of the recording medium P among the nozzle surfaces of the plurality of recording heads H (for example, FIG. 10). Are formed by a plurality of lines formed by a plurality of nozzles provided in the overlapping portion P1).
Here, the pattern Pa is each of the nozzles existing in the overlapping portion P1, and the existing recording head H is formed along the conveyance direction of the recording medium P among a plurality of lines formed by the different nozzles. Consists of multiple lines. From the positional relationship between the plurality of lines, the positional relationship in the direction (width direction) orthogonal to the conveyance direction of the recording medium P among the positional relationships between the recording heads H that overlap in the overlapping portion P1 is known.
Further, the pattern Pb is composed of a plurality of lines formed by the different nozzles of the existing recording head H. The positional relationship in the direction along the conveyance direction of the recording medium P among the positional relationships between the plurality of recording heads H that overlap in the overlapping portion P1 can be understood from the spacing P2 between the plurality of lines. As described above, the positional relationship between the plurality of recording heads H can be confirmed by the positional relationship adjustment image.
Although the recording head H is illustrated in FIG. 10, it is an illustration for showing a relationship with a plurality of lines constituting the patterns Pa and Pb, and an image relating to the recording head H is included in the positional relationship adjustment image. Absent.

Next, the formation of the pattern image Q on both sides of the recording medium P will be described.
When the pattern image Q is formed on both sides of the recording medium P, the control unit 250 causes the image forming unit 120 to apply a blank portion existing on one end side of both ends of the recording medium P in the direction along the conveyance direction by the conveyance unit 110. A pattern image Q is formed.
Specifically, the control unit 250 determines the positional relationship between the image and the pattern image Q so as to form the pattern image Q in the margins on both sides existing on one end side of the recording medium P that is switched back and conveyed by the switchback unit 115. Control. Therefore, as shown in FIG. 11, the pattern image Q is formed on one end side positioned on the downstream side in the transport direction in image formation on one surface (front surface) of the recording medium P, for example. In the image formation on the other surface (back surface), it is formed on one end side positioned on the upstream side in the transport direction. Of course, the control unit 250 may control the positional relationship between the image and the pattern image Q so that the double-sided pattern image Q is formed on the other end opposite to the example shown in FIG.

In connection with the control of the positional relationship between the image and the pattern image Q, the generation unit 230 forms the image on both sides of the recording medium P (for example, the image corresponding to the image data included in the print job) and forms the pattern image Q on both sides. In the case of forming, composite image data in which the positional relationship between the image and the pattern image Q is adjusted so that the pattern image Q is formed in a blank portion existing on one end side is generated for each of both surfaces.
Specifically, for example, as illustrated in FIG. 12, the generation unit 230 stores image data included in a print job and image data corresponding to the pattern image Q in separate memory areas. Of the images corresponding to the image data included in the print job, the generation unit 230 forms a pattern on one end (for example, the upper side shown in FIG. 12) of the image formed on one surface (front surface) of the recording medium P. Composite image data in which the images Q are concatenated is generated. Further, the generation unit 230 determines the other end of the image (for example, the lower side shown in FIG. 12) for the image formed on the other side (back side) of the recording medium P among the images corresponding to the image data included in the print job. Side) to generate combined image data in which the pattern image Q is connected. Here, one end and the other end to which the pattern image Q is connected correspond to end portions in the direction along the conveyance direction of the recording medium P when the image is formed on the recording medium P.
Note that the upper side shown in FIG. 12 corresponds to the downstream side of the image formed on the recording medium P being conveyed. Therefore, the pattern image Q is formed on one end (front surface) of the recording medium P on one end side which is located downstream in the transport direction, and the other surface (back surface) of the recording medium P is transported. A pattern image Q is formed on one end side that will be located upstream in the direction.

The control unit 250 controls the operation of the image forming unit 120 to form the image and the pattern image Q on both sides of the recording medium P using the composite image data generated by the generating unit 230.
Here, for example, as illustrated in FIG. 11, the control unit 250 sets the image forming unit 120 so that the formation regions in the direction along the transport direction coincide with each other among the formation regions of the pattern image Q on both surfaces. The image formation timing of the recording medium and the conveyance timing of the recording medium P by the conveyance unit 110 are controlled.

Next, another image used for adjustment of the image forming unit 120 will be described.
The image forming system 1 according to the present embodiment is not limited to a margin part, and uses an image forming area (for example, an area in which an image corresponding to image data is formed) existing on the recording surface of the recording medium P. It is possible to form an image used for the adjustment of the image.
Specifically, the image forming system 1 records, for example, a shading image (see FIG. 13) for confirming the reproducibility of each shade of colors handled by the image forming unit 120 (for example, four colors of CMYK). Form on medium P.

The shading image is an image formed by increasing or decreasing the amount of ink ejected from the nozzles of each head unit 121 stepwise along the conveyance direction of the recording medium P. Based on the shading image, the reproducibility of color shading depending on the amount of ink ejected onto the recording medium P can be confirmed.
As shown in FIG. 13, the shading image is individually formed for the colors handled by the image forming unit 120. In the example shown in FIG. 13, English initials indicating each color are used as codes for shaded images of yellow (Y), magenta (M), cyan (C), and black (K). In addition, specific aspects, such as the positional relationship of the shading image of each color in the recording medium P, are not restricted to this, It can change suitably.
Of course, the image forming system 1 can also form the pattern image Q in the image forming area existing on the recording surface of the recording medium P, not limited to the blank portion, if necessary.

An image used for adjustment of the image forming unit 120 such as a pattern image Q such as the test chart and the positional relationship adjustment image, a shading image, or the like is read by the reading unit 140. The control unit 250 performs various operations related to the adjustment of the image forming unit 120 based on the reading result by the reading unit 140. Here, as various operations, for example, a condition change by the changing unit 240, a temporary stop of image formation by the image forming unit 120, a process for notifying the user, and the like can be cited.
Here, in the pattern image Q according to the above example, it is sufficient that the test chart is read at a resolution with which it is possible to confirm the presence or absence of line loss or blur. Further, it is sufficient for the shading image to be read at a resolution at which the color density can be confirmed.
On the other hand, of the pattern image Q according to the above example, the positional relationship adjustment image is read at a higher resolution than the test chart and the shading image because of the necessity of adjusting the positional relationship between the recording heads H more precisely. Need to be done.
As described above, an image read by the reading unit 140 requires an image that requires a relatively low resolution reading (such as a test chart or a shading image) and a relatively high resolution reading. There is an image (high-resolution read image) to be performed.

Next, control related to the operation of the transport unit 110 when reading by the reading unit 140 is performed will be described.
The resolution that can be read by the reading unit 140 depends on the performance of the reading unit 140 and the relative moving speed between the reading unit 140 and the recording medium P. Specifically, in the case of this embodiment, when the recording medium P is transported at the transport speed (first transport speed) of the recording medium P when the image is formed by the image forming unit 120, the low-resolution read image is read. The performance of the reading unit 140 is ensured to obtain a resolution that can be obtained at a possible resolution (first resolution) without causing a problem in reading a low-resolution read image.
The reason for the performance of the reading unit 140 will be described. When printing on both sides of the recording medium P, it is related to image formation such as nozzle clogging based on the result of reading a test chart formed together with image formation on one side (front side). This is because, when a problem is found, it is considered preferable to change the conditions relating to image formation on the other side (back side) by the changing unit 240.
If an image is formed in consideration of problems such as nozzle clogging, an image with insufficient image quality may be formed not only on one side but also on the other side (back side). Therefore, it is not preferable from the viewpoint of preventing wasteful consumption of the recording medium P and ink. On the other hand, if the conditions relating to image formation on the other side (back side) are changed by changing the conditions relating to image formation, it is possible to prevent wasteful consumption of the recording medium P and ink caused by the problem.
In order to realize this, the performance of the reading unit 140 is ensured to obtain a resolution with no problem in reading a low-resolution read image such as a test chart at the first transport speed.

However, in the performance of the reading unit 140, the resolution (second resolution) necessary for reading the high-resolution read image is obtained by reading the pattern image Q or the like formed on the recording medium P conveyed at the first conveyance speed. It is not possible. This is because the reading unit 140 that can read the recording medium P conveyed at the first conveyance speed at the second resolution is expensive and difficult to employ in the present embodiment.
Therefore, in order to perform reading with the second resolution, it is necessary to set the conveyance speed of the recording medium P by the conveyance unit 110 to a conveyance speed (second conveyance speed) slower than the first conveyance speed.

The control unit 250 controls the conveyance speed by the conveyance unit 110 based on the relationship between the performance of the reading unit 140 and the conveyance speed described above.
The control unit 250 has a resolution that can be read by the reading unit 140 when the recording medium P is transported at the first transport speed that is the transport speed of the recording medium P when the image forming unit 120 forms an image. When reading at the second resolution, which is higher than the resolution, is necessary and an image is not formed by the image forming unit 120, the transport speed of the recording medium P by the transport unit 110 is set to the first speed. The second transport speed is a transport speed that is slower than the transport speed.
Specifically, for example, when the pattern image Q that needs to be read at the second resolution is formed on the recording medium P, the control unit 250 performs the recording after the formation of the pattern image Q is completed. The medium P is transported to the transport unit 110 at the second transport speed.

To give a more specific example, the control unit 250 records the recording medium P at the first conveyance speed when the pattern image Q that needs to be read at the second resolution is formed on the recording medium P by the image forming unit 120. In the transport of the pattern image Q, the downstream end of the end in the direction along the transport direction of the pattern image Q reaches the reading position SC by the reading unit 140 before the image including the pattern image Q is scanned. When the formation is completed, the control unit 250 sets the conveyance speed of the recording medium P to the second conveyance speed until the recording medium P reaches the reading position SC after the formation of the pattern image Q is completed. A specific example will be described with reference to FIG.
In the present embodiment, as shown in FIG. 14, the most downstream side in which an image is formed on the recording medium P by the image forming unit 120 in the conveyance path of the recording medium P carried by the drum 110 a and conveyed. Between the position and the reading position SC by the reading unit 140, there is provided a deceleration area SL for reducing the transport speed of the recording medium P transported at the first transport speed to the second transport speed. The deceleration area SL is, for example, a straight line connecting the end position on the downstream side of the predetermined irradiation area A and the rotation center of the drum 110a, and a straight line obtained by extending the reading position SC by the reading unit 140 to the rotation center of the drum 110a. The region corresponding to the rotation angle range of the drum 110a to be formed is an example and is not limited to this.
For example, an image (pattern image Q of a high-resolution read image) is recorded on the recording medium P before the downstream end of the recording medium P carried and conveyed by the drum 110a reaches the upstream end of the deceleration region SL. Of the end in the direction along the conveyance direction of the pattern image Q formed on the recording medium P reaches the reading position SC by the reading unit 140. Before the pattern image Q is formed, the formation of the pattern image Q is completed. In this case, the control unit 250 rotates the drum 110a during the rotation operation of the drum 110a until the downstream end of the recording medium P passes through the deceleration region SL and reaches the reading position SC by the reading unit 140. Decelerate. Thereby, the control unit 250 reduces the transport speed of the recording medium P transported at the first transport speed during image formation to the second transport speed. Then, the control unit 250 operates the reading unit 140 to read the high-resolution read image formed on the recording medium P conveyed at the second conveyance speed at the second resolution.

  For example, the control unit 250 acquires the positional relationship between the recording medium P carried on the drum 110a and the image forming unit 120, the irradiation unit 130, and the reading unit 140 based on the detection result by the detection unit 110b, and the conveyance speed. However, this is an example and not limited to this. For example, based on the image data including the pattern image Q, such as the composite image data, the control unit 250 determines to which part of the upstream side of the transported recording medium P the image including the pattern image Q is continued. The position information indicated is acquired. Further, the control unit 250 acquires the position information of the recording medium P detected by the detection unit 110b. In addition, based on the position information, the control unit 250 captures an image at a timing when the downstream end of the pattern image Q formed on the transported recording medium P reaches the upstream end of the deceleration region SL. You may make it determine the presence or absence of continuation of formation. The image forming unit 120 forms an image including the pattern image Q before the downstream end of the end of the pattern image Q along the conveyance direction reaches the upstream end of the deceleration region SL. Is completed, the control unit 250 sets the transport speed of the recording medium P to the second transport until the recording medium P reaches the reading position SC after the image forming unit 120 completes the formation of the image including the pattern image Q. You may make it speed.

When the pattern image Q that needs to be read at the second resolution is formed on the recording medium P by the image forming unit 120, the control unit 250 uses the re-conveying unit (for example, the switchback unit 115) to read the reading unit 140. The recording medium P transported upstream may be transported to the transport unit 110 at the second transport speed.
For example, in the case of image formation on one surface (front surface) where the pattern image Q is formed on the downstream side in the transport direction, the downstream end of the recording medium P passes through the deceleration region SL and is read by the reading unit 140. It is conceivable that image formation on the recording medium P is continued even when reaching SC. For this reason, when the pattern image Q is a high-resolution read image, the conveyance speed must be reduced in order to read the pattern image Q. However, the reduction in the conveyance speed during image formation is caused by the ink ejection position. It affects the image quality, such as changes. In this way, when the reading unit 140 cannot perform the deceleration for reading during conveyance accompanying image formation, the control unit 250 completes the image formation without reducing the conveyance speed during image formation. . At this time, the reading unit 140 does not operate. Thereafter, the control unit 250 operates the switchback unit 115 to re-transport the recording medium P on which the image is formed. Specifically, the control unit 250 performs the inversion of the recording medium P by the switchback unit 115 twice. As a result, the recording medium P on which one surface (front surface) on which the pattern image Q is formed on the upstream side in the transport direction is opposed to the reading unit 140 is turned over by the first reversal and then the second reversal. Then, the drum 110 a is again carried with one surface (front surface) facing the reading unit 140. At the same time, the recording medium P is conveyed to the upstream side of the reading unit 140 due to inversion by the switchback unit 115. After the recording medium P is reversed twice by the switchback unit 115, the control unit 250 sets the conveyance speed of the recording medium P to the second conveyance speed, operates the reading unit 140, and conveys the recording medium P at the second conveyance speed. The high-resolution read image formed on the recording medium P to be read is read at the second resolution.
Note that not only the pattern image Q that is a high-resolution read image but also an image that needs to be read at the second resolution is formed, the downstream end of the recording medium P passes through the deceleration region SL and is read. When the image formation on the recording medium P is continued when the reading position SC is reached by the unit 140, the control unit 250 causes the re-conveying unit (for example, the switchback unit 115) to move upstream of the reading unit 140. The transported recording medium P is transported to the transport unit 110 at the second transport speed.

In addition, when the recording medium P is transported at the second transport speed, the control unit 250 is configured to transport the irradiation amount per unit time of the energy irradiated by the irradiation unit 130 at the first transport speed. Less than.
Specifically, when the recording medium P is transported at the second transport speed and the energy irradiation by the irradiation unit 130 is necessary, the control unit 250 records the recording medium P transported at the second transport speed. Irradiation is performed by the irradiation unit 130 for the purpose of making the integrated amount of energy per unit area (for example, integrated light amount) uniform and the integrated amount of energy per unit area of the recording medium P transported at the first transport speed. The amount of energy applied per unit time is reduced as compared with the case where the recording medium P is transported at the first transport speed.
More specifically, for example, as shown in FIG. 14, the image formation by the image forming unit 120 has been completed, and even if the conveyance speed of the recording medium P is decreased in the deceleration region SL, the ink discharge position can be changed. Even if there is no influence on the image quality due to the change, the irradiation of energy to the image formed on the recording medium P is completed when the downstream end of the recording medium P reaches the reading position SC by the reading unit 140. There may be cases where it is not. In such a case, if the energy irradiation amount by the irradiation unit 130 remains the same as the first conveyance speed, the integrated amount of energy for the image passing through the predetermined irradiation area A after being decelerated to the second conveyance speed is obtained. More than the image passing through the predetermined irradiation area A in the state of being transported at the first transport speed. Therefore, the control unit 250 reduces the irradiation amount of energy irradiated by the irradiation unit 130 per unit time as compared with the case where the recording medium P is transported at the first transport speed. The specific degree of reduction depends on, for example, the ratio between the first transport speed and the second transport speed.

  The control unit 250 may not operate the irradiation unit 130 when the recording medium P is transported at the second transport speed. For example, the re-transport unit (for example, switchback unit 115) transports the recording medium P to the upstream side of the reading unit 140, and transports the recording medium P to the transport unit 110 at the second transport speed. When reading at the second resolution, the image formation on the recording medium P conveyed to the upstream side of the reading unit 140 has already been completed. In such a case, there is no need to re-irradiate the recording unit P with energy applied by the irradiation unit 130, so the control unit 250 stops the operation of the irradiation unit 130, and the irradiation unit 130 The irradiation amount per unit time of the energy irradiated by 130 is set to zero.

Further, when the pattern image Q that can be handled by reading at the first resolution is formed on the recording medium P, the control unit 250 records the recording medium at the first transport speed performed when the pattern image Q is formed on the transport unit 110. Continue carrying P.
Specifically, for example, reading of the recording medium P conveyed at the first conveying speed, such as reading of a low-resolution read image by the reading unit 140, can ensure a sufficient resolution according to the purpose. In this case, the conveyance at the first conveyance speed can be continued regardless of whether or not the image is formed when the low-resolution read image reaches the reading position SC by the reading unit 140. Therefore, the control unit 250 continues the conveyance of the recording medium P at the first conveyance speed performed when the low resolution read image is formed on the conveyance unit 110, and the low resolution read image is formed at the reading position SC by the reading unit 140. The recording medium P is passed.
In addition to the pattern image Q that is a low-resolution read image, when reading an image that can be handled by reading at the first resolution, such as a shading image, the control unit 250 sends the image to the transport unit 110. The conveyance of the recording medium P at the first conveyance speed performed at the time of forming is continued, and the recording medium P on which the image is formed is passed near the reading unit 140.

  As described above, according to the image forming system 1 of this embodiment, the positional relationship between the irradiation unit 130 and the reading unit 140 is such that the irradiation unit 130 irradiates the recording medium P with energy and the reading unit 140 of the recording medium P. Since the positional relationship does not overlap with the reading position SC where reading is performed, even if the irradiation unit 130 is operating during the reading operation by the reading unit 140, reading by the reading unit 140 can be performed without any problem. That is, according to the image forming system 1 of the present embodiment, it is possible to further reduce the influence of the energy irradiated on the recording medium P by the irradiation unit 130 on the reading result by the reading unit 140.

In addition, since the shielding unit 132 that blocks a part of the energy irradiated from the irradiation unit 130 is provided between the irradiation unit 130 and the reading unit 140, it is possible to limit a range in which the energy irradiated from the irradiation unit 130 reaches. Therefore, the positional relationship in which the irradiation range where the recording medium P is irradiated with energy by the irradiation unit 130 and the reading position SC where the reading unit 140 reads the recording medium P does not overlap can be realized more easily.
In addition, since the irradiation unit 130 and the reading unit 140 can be brought closer to each other, the image forming apparatus (main body unit 100) can be made more compact.

  Further, the positional relationship between the irradiation unit 130 and the reading unit 140 is that the reading unit 140 reads the intensity of light entering the reading position SC when the reading unit 140 reads an image out of the light emitted from the irradiation unit 130. The positional relationship is equal to or lower than the light intensity necessary for detecting the gradation difference of the image to be obtained. Accordingly, since both the irradiation unit 130 and the reading unit 140 are provided so as to face the recording medium P conveyed by the conveyance unit 110, it is difficult to completely physically separate the irradiation unit 130 and the reading unit 140. Even when a part of the energy irradiated from the irradiation unit 130 reaches the reading position SC of the reading unit 140, the energy is read by the shielding unit 132 by attenuating the arrival of the energy. It is possible to prevent the reading of an image by 140 from being affected.

  Further, when the pattern image Q is formed on both surfaces of the recording medium P, the control unit 250 forms an image forming unit on a blank portion existing on one end side of both ends of the recording medium P in the direction along the conveyance direction by the conveyance unit 110. Since the pattern image Q is formed by 120, the other end of both sides can be used for image formation. Therefore, more images are formed on both sides of the recording medium P in the formation of the image and the pattern image Q. Can be used.

  Further, when the generation unit 230 forms the pattern image Q on both sides together with the image formation on both sides of the recording medium P, the positions of the image and the pattern image Q so that the pattern image Q is formed in the blank portion existing on one end side. Since the composite image data whose relationship is adjusted is generated for each of both sides, the control unit 250 only forms the image and the pattern image Q on both sides of the recording medium P using the composite image data generated by the generation unit 230. Thus, since the pattern image Q can be formed in the blank portion existing on one end side for each of both surfaces of the recording medium P, the processing relating to the positional relationship between the image and the pattern image Q on each of both surfaces is further simplified. be able to.

  Furthermore, the control unit 250 determines the image formation timing by the image forming unit 120 and the conveyance unit 110 so that the formation regions in the direction along the conveyance direction coincide with each other among the formation regions of the pattern image Q on both sides. Since the conveyance timing of the recording medium P is controlled, the area used for the pattern image Q in the conveyance direction can be matched on both sides, so that the image forming unit 120 can form an image on the recording medium P. Of these, the area other than the area of the pattern image Q can be used in common for both sides to form an image other than the pattern image Q (an image corresponding to the image data), and a larger area can be used for image formation. Can do.

  Further, the control unit 250 uses the transport unit 110 when reading at the second resolution, which is higher than the first resolution, is required and an image is not formed by the image forming unit 120. Since the conveyance speed of the recording medium P is the second conveyance speed, which is a conveyance speed slower than the first conveyance speed, the conveyance speed of the recording medium P with respect to the reading unit 140 in image reading is further reduced without degrading the image quality. It is possible to realize both compatibility with both the first resolution and the second resolution and ensuring the image quality by controlling the transport speed according to the required resolution.

  Furthermore, when the pattern image Q that needs to be read at the second resolution is formed on the recording medium P by the image forming unit 120, the control unit 250 removes the recording medium P from the second after the formation of the pattern image Q is completed. Since the sheet is conveyed to the conveyance unit 110 at the conveyance speed, the conveyance speed of the recording medium P with respect to the reading unit 140 in image reading can be further reduced without causing disturbance in the formation of the pattern image Q. Therefore, it is possible to realize both the control of the conveyance speed for reading the pattern image Q that needs to be read and the formation of the correct pattern image Q.

  Further, in the transport of the recording medium P at the first transport speed when the pattern image Q that needs to be read at the second resolution is formed on the recording medium P by the image forming unit 120, the pattern image Q is transported in the transport direction. When the formation of the image including the pattern image Q by the image forming unit 120 is completed before the downstream end of the end along the direction reaches the reading position SC by the reading unit 140, the control unit 250 Since the conveyance speed of the recording medium P is set to the second conveyance speed until the recording medium P reaches the reading position SC after the formation of the pattern image Q is completed, the switchback unit 115 is accompanied by the conveyance for image formation. The pattern image Q can be read without re-conveying using a configuration relating to re-conveying such as image formation and patterning including the formation of the pattern image Q through a shorter conveying path. Read image Q bets can be performed.

  Furthermore, when the pattern image Q that needs to be read at the second resolution is formed on the recording medium P by the image forming unit 120, the control unit 250 uses the re-conveying unit (for example, the switchback unit 115) to read the reading unit 140. Since the recording medium P transported upstream is transported to the transport unit 110 at the second transport speed, the transport speed is set to the second transport during image formation involving the formation of the pattern image Q that requires reading at the second resolution. Even if the speed cannot be achieved, the pattern image Q can be read at the second resolution.

  Further, when the pattern image Q that can be handled by reading at the first resolution is formed on the recording medium P, the control unit 250 records the recording medium at the first transport speed performed when the pattern image Q is formed on the transport unit 110. Since the conveyance of P is continued, the pattern image Q can be read along with the conveyance for image formation without passing through the re-conveyance using the configuration related to the re-conveyance such as the switchback unit 115. Image formation including formation of the pattern image Q and reading of the pattern image Q can be performed on the conveyance path.

  Furthermore, when the recording medium P is transported at the second transport speed, the control unit 250 is configured to transport the irradiation amount per unit time of the energy irradiated by the irradiation unit 130 at the first transport speed. Therefore, the integrated amount of energy per unit area of the recording medium P conveyed at the second conveyance speed (for example, the integrated light amount) and the unit area of the recording medium P conveyed at the first conveyance speed. Since the integrated amount of energy can be made uniform, the image quality of the image fixed on the recording medium P can be made uniform regardless of the conveyance speed.

  Further, since the controller 250 does not operate the irradiation unit 130 when the recording medium P is conveyed at the second conveyance speed, the irradiation unit 130 operates during conveyance of the recording medium P without the operation of the image forming unit 120. Therefore, it is possible to prevent waste of energy, change of the recording medium P and an image formed on the recording medium P due to unnecessary energy irradiation, and the like.

  Further, the image forming system 1 includes a reversing unit (for example, a switchback unit 115), and the reading unit 140 is provided on the downstream side of the image forming unit 120 in the transport direction and on the upstream side of the reversing unit. Since both sides of the recording medium P can be read by the reading unit 140 by the operation of the double-sided conveyance mechanism, the recording medium P can be read without providing a dedicated reading unit 140 for reading each of both sides. Therefore, both sides can be read with a cheaper configuration.

  Furthermore, since the change unit 240 that changes the conditions related to the image formation by the image forming unit 120 based on the reading result by the reading unit 140 is provided, the reading result by the reading unit 140 should not continue the image formation without changing the condition. By changing the conditions when an event (for example, nozzle clogging, etc.) is indicated, it is possible to perform operation control corresponding to the event in image formation, so an image formed under inappropriate conditions Various types of waste (for example, waste of the recording medium P and ink and waste of time spent for image formation under inappropriate conditions) can be prevented.

  Furthermore, since the conditions changed by the changing unit 240 include conditions relating to ink ejection from the nozzles, the reading result by the reading unit 140 continues image formation without changing the conditions relating to ink ejection from the nozzles. When an event that should not have occurred (for example, nozzle clogging, etc.), it is possible to perform operation control corresponding to the event in image formation by changing the condition. It is possible to prevent various types of waste such as wasteful consumption of ink caused by the printed image.

  Furthermore, since the reading unit 140 is provided on the downstream side of the irradiation unit 130, an image that is fixed by the irradiation unit 130 and does not change any more can be read by the reading unit 140, which is equivalent to an image visually recognized by the user. Image reading results can be obtained.

  Furthermore, since the distance between the image forming unit 120 and the irradiation unit 130 and the reading unit 140 can be arranged close to each other within a range that does not affect the reading result, the changing unit 240 that changes a condition related to image formation by the image forming unit 120. Therefore, it is possible to prevent various kinds of waste such as waste of ink caused by an image formed under an inappropriate condition.

  The embodiment of the present invention should be considered that the embodiment disclosed this time is illustrative and not restrictive in all respects. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

For example, the control unit 250 may control the formation position of the pattern image Q on the recording medium P so that the formation position of the pattern image Q on each of both surfaces does not overlap on both faces.
Specifically, for example, as shown in FIG. 15, with respect to the width direction of the recording medium P, the pattern image Q is formed on the region where the pattern image Q is formed on one surface (front surface) and the other surface (back surface). You may make it divide | segment the area | region used. Such area control of the pattern image Q can be performed for the pattern image Q that falls within an area that is not more than half of the maximum width in which the image can be formed in the width direction of the recording medium P. As a specific example, formation of a test chart of the image forming unit 120 having the head unit 121 that reciprocates in the width direction as in a non-one-pass type ink jet recording apparatus can be cited.

In addition, the control unit 250 performs operation control related to the formation of the pattern image Q so that the pattern image Q is formed only on one surface and not formed on the other surface (for example, when the discrepancy is impossible). May be.
Specifically, for example, in the case of the recording medium P in which an image formed on one surface (front surface) can be seen through from the other surface (back surface), the pattern images Q formed on one end side overlap each other. A case where the reading result of the pattern image Q formed on the other surface cannot be obtained correctly is considered. In this case, the controller 250 may form the pattern image Q only on one side and not on the other side.

  Further, in the above embodiment, the generation unit 230 provided in the main body unit 100 generates the composite image data, but this is an example and the present invention is not limited to this. For example, since the information processing apparatus connected to the image forming system 1 such as the PC shown in FIG. 2 forms an image on both sides of the recording medium P and forms the pattern image Q on both sides, a blank space on one end side exists. The composite image data in which the positional relationship between the image and the pattern image Q is adjusted so as to form the pattern image Q in the part is generated for each of both surfaces and output to the image forming apparatus. The control unit 250 of the image forming system 1 The image and the pattern image Q may be formed on both sides of the recording medium P using the composite image data output from the information processing apparatus.

Further, in the composite image data generated by the information processing apparatus connected to the image forming system 1, the formation areas in the direction along the transport direction among the formation areas of the pattern image Q for each of the both faces coincide with each other. A blank portion corresponding to the carry amount for adjusting the image formation timing by the image forming unit 120 may be included.
Specifically, the composite image data includes, for example, a pattern image Q arranged so that the pattern image Q is formed on one end side and an image other than the pattern image Q (as shown in FIG. Corresponding images, which are images formed on both sides), and the maximum area where image formation by the image forming unit 120 on one side of the recording medium P is possible. You may have a blank part corresponding to fields other than a formation field. Here, as shown in FIG. 16, the pattern image Q in the composite image data is adjusted so that the formation areas of the pattern image Q on both surfaces coincide with each other in the direction along the conveyance direction.

  The information processing apparatus generates composite image data for both sides and outputs the composite image data to the image forming apparatus, so that the control unit 250 does not perform special control related to the position of the pattern image Q, but each pattern image on both sides. Q can be formed on one end side of the recording medium P.

Further, in the composite image data generated by the information processing apparatus connected to the image forming system 1, the formation areas in the direction along the transport direction in the formation areas of the pattern image Q for each of the both faces coincide with each other. By including a blank portion corresponding to the conveyance amount for adjusting the image formation timing by the image forming unit 120, the area used for the pattern image Q in the conveyance direction can be more easily matched on both sides. Of the areas where the image forming unit 120 can form an image on the recording medium P, the area other than the area of the pattern image Q is shared on both sides, and an image other than the pattern image Q (an image corresponding to the image data) is stored. More regions can be used for image formation.
In the case of the example shown in FIG. 16, the blank portion is provided on the other end side on both sides, but this is an example and the present invention is not limited to this. For example, a blank portion may be provided between the blank portion where the pattern image Q is formed and the portion where the image corresponding to the image data is formed, or a part of the periphery of the image corresponding to the image data Or a blank part may be provided in all.

In the above embodiment, the reading unit 140 reads the pattern image Q and the shading image. However, the reading unit 140 is an example, and the reading unit 140 is not limited to this. The image formed on a medium that can be transported by the transport unit 110. Anything can be read.
Here, as shown in FIG. 17, the main body 100 of the image forming system 1 further includes image data that is the basis of an image formed by the image forming unit 120 and the image forming unit 120 based on the image data. The comparison unit 270 may be provided that compares the read data generated by reading the image formed by the reading unit 140 with the reading unit 140. In this case, the changing unit 240 may change the condition based on the comparison result by the comparing unit 270.

Further, the conditions relating to image formation changed by the changing unit 240 are not limited to the conditions relating to ink ejection from the nozzles.
For example, the condition may include content related to the brightness of the image.
For example, the changing unit 240 may change the degree of ink ejection related to the reproduction of the shading of each color based on the reading result of the shading image by the reading unit 140. Further, the image formed on the basis of the image data is read by the reading unit 140, and each color (for example, four colors of CMYK) used for forming the image is compared by the comparison unit 270, and formed on the recording medium P. You may make it change the discharge amount of the ink of each color, etc. so that the brightness of an image may be made the same with the brightness in image data.

  As described above, when the condition includes the content related to the brightness of the image, the brightness of the image formed on the recording medium P can be made the same as the brightness in the image data.

Further, the specific contents of the conditions relating to image formation changed by the changing unit 240 are not limited to the above example.
For example, when the number of nozzles in which clogging is detected is equal to or greater than a predetermined number based on the reading result of the test chart, the changing unit 240 relates to image formation so as to stop image formation by the image forming unit 120. Conditions may be changed. In this case, the control unit 250 may cause the image forming unit 120 to perform a maintenance operation for eliminating clogging of the nozzles. Specific contents of the maintenance operation include, for example, ejection that eliminates nozzle clogging by moving the head unit 121 to the cleaning unit and driving the nozzles to forcibly eject ink from the clogged nozzles. Maintenance is mentioned.

Further, the comparison by the comparison unit 270 is not limited to the comparison related to the brightness of the image.
For example, the comparison unit 270 checks each pixel in the image data and each image data in the image data corresponding to the reading result generated by reading by the reading unit 140 in order to confirm the reproducibility of the image formed on the recording medium P. You may make it compare with a pixel. Here, when it is confirmed that there is a problem in the reproducibility of the image, such as the degree of color difference of each pixel exceeds a predetermined degree, the changing unit 240 stops image formation by the image forming unit 120. In this way, the conditions relating to image formation may be changed. As a result, for example, when a problem such as a white streak that does not exist in the image in the image data occurs in the image formed on the recording medium P, the image formation is continued as it is, and the recording medium P or ink is wasted. Can be prevented from further occurring.
Note that items that serve as a reference for stopping image formation, such as the predetermined number and the predetermined degree, can be arbitrarily set by a user operation via the setting unit 210 or the like.

  In the above embodiment, the shielding part 132 is extended from the side part of the casing of the light source 131 toward the outer peripheral surface side of the drum 110a of the transport part 110. However, this is an example and the present invention is not limited thereto. Not. For example, it may be provided independently of the irradiation unit 130 and the reading unit 140 like a light shielding plate provided so as to be interposed between the irradiation unit 130 and the reading unit 140. Further, the shielding unit 132 may be provided integrally with the reading unit 140.

Moreover, in said embodiment, although the energy irradiated from the irradiation part 130 is an ultraviolet-ray, it is an example and is not restricted to this. Specific examples of other energies include infrared (IR), other light beams that cause the ink to cure, or waves such as electromagnetic waves, or heat generated by these waves. The energy is specifically selected according to the characteristics of the ink.
Further, the specific content related to the influence of the energy irradiated from the irradiation unit 130 on the reading unit 140 depends on the energy. For example, when IR is used as energy, the influence of light having a wavelength of 700 [nm] or more among light having a wavelength at which the CCD image sensor exhibits sensitivity is more seriously considered. The specific structure and material of the shielding unit 132 are also provided so as to shield part of the energy irradiated from the irradiation unit 130 between the irradiation unit 130 and the reading unit 140.
In addition, the reading unit 140 of the present embodiment based on the example illustrated in FIG. 6 is a CCD image sensor, but is an example and is not limited thereto. The influence of the energy irradiated from the irradiation unit 130 depends on the characteristics of the image sensor employed as the reading unit 140.

  Further, the shielding unit 132 in the above embodiment is provided between the irradiation unit 130 and the reading unit 140 for the purpose of setting a range (irradiation range) irradiated with ultraviolet rays emitted from the light source 131 as a predetermined irradiation region A. Although it extends beyond the position which interrupts a part of energy irradiated from the irradiation part 130, it is an example and is not restricted to this, At least between the irradiation part 130 and the reading part 140 It may be provided so as to block a part of the energy irradiated from the irradiation unit 130.

  In addition, the image forming unit 120 in the above-described embodiment performs image formation by an inkjet method, but is an example and is not limited thereto. For example, the image forming unit 120 is a primary transfer unit that forms an image on a photoconductor provided to contact the recording medium P carried on the drum 110a, and a secondary transfer that transfers an image from the photoconductor to the recording medium P. The image may be formed by an electrophotographic method or an image may be formed by another image forming method.

Further, the control unit 250 may control the conveyance of the recording medium P based on the reading result by the reading unit 140.
Specifically, for example, the recording medium P on which an image determined to be defective based on the reading result by the reading unit 140 is discharged to the sub-tray 20b, and only the recording medium P on which an image determined to be normal is formed. The discharge switching guide 113 may be controlled so as to be discharged to the main tray 20a. By performing such control, the user can easily distinguish between the recording medium P on which an image is normally formed and the recording medium P on which an image determined to be defective is formed.
Even when images are formed on both sides, if it is determined that the image recorded on the first side (front side) is abnormal, the recording medium P is not conveyed to the switchback unit 115 and the belt The paper may be immediately discharged to the sub-tray 20b via the loop 112 and the discharge switching guide 113, and the image formation may be performed again on another recording medium P after changing the above-described conditions for image formation. As a result, waste of materials such as ink and time due to wasteful recording on the recording medium P can be prevented.
In the case where images are formed on both sides, and the image recorded on the first side (front side) after transporting the recording medium P to the switchback unit 115 is determined to be abnormal, the second side If the image formation on the (back side) is not started, the recording medium P is discharged to the sub-tray 20b via the drum 110a, the cylinder 111, the belt loop 112, and the discharge switching guide 113 without image formation, and the second side (back side). After the start of the image formation, the back side image formation may be stopped, and the recording medium P may be discharged to the sub-tray 20b via the drum 110a, the cylinder 111, the belt loop 112, and the discharge switching guide 113. Accordingly, it is possible to prevent waste of materials such as ink due to wasteful recording on the recording medium P.

In the above embodiment, the deceleration region SL is set in connection with the control of the conveyance speed, but this is an example and the present invention is not limited to this.
For example, in the transport of the recording medium P at the first transport speed when the pattern image Q that needs to be read at the second resolution is formed on the recording medium P by the image forming unit 120, the pattern image Q is transported in the transport direction. When the formation of the image including the pattern image Q by the image forming unit 120 is completed before the downstream end of the end along the direction reaches the reading position SC by the reading unit 140, the control unit 250 The conveyance unit 110 may be stopped once when the formation of the image Q is completed, and then the recording medium P may be conveyed to the conveyance unit 110 at the second conveyance speed. In this case, even if the deceleration area SL is not set, the recording medium that is transported at the second transport speed in the transport process in the transport process of the recording medium P when the pattern image Q is formed on the recording medium P. P can be read by the reading unit 140.

  In addition, the specific configuration of the acquisition unit 220 described above is an example and is not limited thereto. The acquisition unit 220 may include various interfaces that can be connected to a storage device that stores image data that is a source of an image formed on the recording medium P, such as a hard disk or a flash memory card.

In the above embodiment, the switchback unit 115 reverses and re-transports the paper. However, the switchback unit 115 is an example, and the present invention is not limited to this. The specific composition is not asked. For example, a reversing and re-transporting mechanism by a combination of a plurality of rollers may be used.
In the above-described embodiment, the drum 110a carries the recording medium P and is transported. However, the embodiment is not limited to this example, and the transport unit 110 may be configured to transport paper. Good. For example, the transport unit 110 may have a transport mechanism using a belt carried by a plurality of rollers.
In addition, the number of reading units 140 in the above embodiment is one, but this is an example and the present invention is not limited to this. For example, the main body unit 100 may include a plurality of reading units 140.
In addition, the specific configuration of the embodiment of the present invention can be changed as appropriate without departing from the characteristics of the present invention.

  The present invention can be used in an image forming apparatus.

1 Image Forming System 100 Main Body (Image Forming Apparatus)
DESCRIPTION OF SYMBOLS 110 Conveyance part 120 Image formation part 130 Irradiation part 131 Light source 132 Shielding part 132a Extension part 140 Reading part 250 Control part A Irradiation area P Recording medium SC Reading position

Claims (1)

An image forming unit for forming an image on a recording medium;
Wherein the image by the image forming part is formed, an irradiation unit that irradiates the energy for fixing the image on the recording medium conveyed is placed in a predetermined conveying surface,
A reading unit reading the image fixed on the recording medium conveyed is placed on the conveying surface,
A shielding unit that blocks at least a part of energy irradiated from the irradiation unit between the irradiation unit and the reading unit;
With
The positional relationship between the irradiation unit and the reading unit is a positional relationship in which an irradiation range in which energy is applied to the recording medium by the irradiation unit and a reading position where the reading unit reads the recording medium do not overlap.
The irradiation unit irradiates the energy by irradiating light,
The positional relationship is such that the absolute value of the intensity of light entering the reading unit among the light irradiated from the irradiation unit corresponds to the minimum gradation difference that can be detected by the reading unit in reading the image. positional relationship der equal to or less than the magnitude of the intensity difference is,
The image forming apparatus according to claim 1, wherein the shielding portion includes an extending portion that extends so that an end portion on the conveying surface side extends along the conveying surface .

Images