JP6248776B2 - Image forming apparatus and method of controlling image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus and an image forming apparatus control method.

  In recent years, there is an image forming apparatus in which a color sensor is arranged. Such an image forming apparatus performs color adjustment by reading a color patch printed at a predetermined position in a sheet with a color sensor and feeding it back at the next image printing. This technique of measuring colors by providing a color sensor in the apparatus is called in-line color measurement.

  In in-line colorimetry, a sheet of paper that is one size larger than the final image size is prepared, and a color patch is created at a position at the end of the sheet that does not cover the image to be printed. The color patch is read by a color sensor built in the apparatus, and the read result is used for color correction in subsequent image formation. As a result, the image quality of the image created by the image forming apparatus, particularly the color reproducibility can be improved (for example, Patent Document 1).

JP-A-2005-321568

  However, in the conventional technique, a color sensor installed in the apparatus is fixed. For this reason, the position of the color patch created on the paper is limited to a position that can be read by the color sensor.

  However, depending on the image to be formed, the color patch may overlap with the image, or the color patch may come close to the image. In this case, the color patch interferes with the image, so the color patch cannot be printed, and inline colorimetry cannot be performed.

  Accordingly, an object of the present invention is to provide an image forming apparatus that can reliably read a color patch even if the color patch is printed at an arbitrary position on a sheet, and a control method therefor.

  The above object of the present invention is achieved by the following means.

(1) a printing unit that prints an image including a color patch in which a plurality of colors are continuously or intermittently arranged on a sheet;
A color patch position information receiving unit for receiving the position of the color patch on the paper;
A plurality of pixels linearly arranged in the longitudinal direction, and a color sensor that reads the color patch by the plurality of pixels ;
A color sensor moving unit for moving the color sensor to an arbitrary position on the paper and changing the orientation of the color sensor;
Based on the position of the color patch received by the color patch position information receiving unit, the longitudinal direction of the color sensor is the same as the direction in which a plurality of colors of the color patch printed on a sheet are arranged. the by changing the moving is not Rutotomoni facing the color sensor, and a control unit for the color patch read by the color sensor,
An image forming apparatus comprising:

(2) The image forming apparatus according to (1) , wherein in the color sensor , the plurality of pixels are arranged more than a length of the color patch .

  (3) Further, a conveyance stop unit that temporarily stops conveyance of the sheet or a conveyance delay unit that delays conveyance of the sheet is provided so that the color sensor can read the color patch during conveyance of the sheet. The image forming apparatus according to (1) or (2).

(4) a printing unit that prints an image including a color patch in which a plurality of colors are continuously or intermittently arranged on a sheet;
A color patch position information receiving unit for receiving the position of the color patch on the paper;
A plurality of pixels linearly arranged in the longitudinal direction, and a color sensor that reads the color patch by the plurality of pixels ;
A color sensor moving unit for moving the color sensor to an arbitrary position on the paper and changing the orientation of the color sensor;
An image forming apparatus control method comprising:
Receiving the position of the color patch by the color patch position information receiving unit;
Received based on the position of the color patch, the longitudinal direction of the color sensor, so that the same direction as the direction in which the plurality of colors are arranged in the color patches printed on paper, Before moving the color sensor comprising the steps of: Ru to change the orientation with,
Causing the color sensor to read the color patch;
A control method for an image forming apparatus, comprising:

(5) The control method of the image forming apparatus according to (4) , wherein the color sensor has the plurality of pixels arranged in a length equal to or longer than the length of the color patch .

(6) The step of causing the color sensor to read the color patch includes:
The image forming apparatus according to (4) or (5), further comprising a step of temporarily stopping or delaying paper conveyance so that the color sensor can read the color patch during conveyance of the paper. Control method.

  According to the present invention, the color sensor moving unit that can move the color sensor to an arbitrary position on the paper is provided, and based on the position information of the color patch, the color patch printed on the paper is read. The color sensor was moved to read the color patch. Thereby, the color patch printed on which position on the paper can be read. Therefore, it is possible to perform in-line color measurement no matter where the color patch is placed (printed) on the paper, and the user can print without worrying about the position of the color sensor provided inside the image forming apparatus. The color patch can be arranged in accordance with the image to be performed, and the inline side color and the resulting color correction can be performed.

1 is an explanatory diagram for explaining a configuration of an image forming apparatus according to an embodiment to which the present invention is applied. 3 is a block diagram illustrating an example of a hardware configuration of a control unit in the image forming apparatus. FIG. It is a schematic perspective view of a color sensor and a moving unit that moves and rotates the color sensor. It is explanatory drawing explaining arrangement | positioning and movement of a color sensor. It is explanatory drawing explaining arrangement | positioning and movement of a color sensor. It is explanatory drawing for demonstrating the printing position of a color patch. It is explanatory drawing for demonstrating the printing position of a color patch. It is a flowchart which shows the color patch preparation procedure in PC. 3 is a flowchart illustrating an inline color measurement process procedure of the image forming apparatus according to the first exemplary embodiment. It is explanatory drawing which shows an example of a color patch. 10 is a flowchart illustrating an inline color measurement processing procedure of the image forming apparatus according to the second embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Embodiment 1]
FIG. 1 is an explanatory diagram for explaining a configuration of an image forming apparatus according to an embodiment to which the present invention is applied. FIG. 2 is a block diagram illustrating an example of a hardware configuration of a control unit in the image forming apparatus.

  This image forming apparatus is connected to a client computer (hereinafter referred to as a PC (Personal Computer)) 30 which is an external device via a network 18.

  The image forming apparatus 10 includes a control unit 11, a paper feeding unit 12, a printing unit 13, a post-processing device 14, and an operation panel 15. Further, a color sensor (abbreviated as CS in the figure) 100 and a color sensor moving unit 110 for moving and rotating the color sensor 100 are provided inside the apparatus.

  As shown in FIG. 2, the control unit 11 includes a CPU (Central Processing Unit) 21, a ROM (Read Only Memory) 22, a RAM (Random Access Memory) 23, a hard disk drive (Hard Disk Drive: HDD) 24, a network interface (Network). (Interface: NIF) 27 is provided. These units are connected to each other by a bus 28 for exchanging signals. The control unit 11 is connected to the sheet feeding unit 12, the printing unit 13, the operation panel 15, the color sensor 100, and the like so that control signals can be exchanged by the internal wiring 17 (see FIG. 1). A post-processing device 14 is connected to the image forming apparatus. The paper feed unit 12, the printing unit 13, and the post-processing device 14 are connected by a transport unit 16 that transports paper.

  The control unit 11 controls each unit of the image forming apparatus. The control performed here is control related to the operation of the image forming apparatus, such as printing according to print settings and post-processing control for the printed paper. Since the basic control related to such printing (image formation) is the same as that used in a general image forming apparatus, detailed description thereof is omitted.

  In this embodiment, the control unit 11 also performs control such as position change of the color sensor 100 and color measurement control (both described later) by the color sensor 100.

  These control programs are stored in advance in the HDD 24 and read out to the RAM when necessary to be executed by the CPU 21.

  The ROM 22 stores various programs for executing basic operations necessary as a minimum as an image forming apparatus. For example, it stores a program for basic operations such as determining whether each unit operates normally when the image forming apparatus is turned on, and reading a program necessary for subsequent processing from the HDD 24. Yes.

  The RAM 23 temporarily stores programs and data as a work area for the CPU 21.

  The HDD 24 stores programs and print settings necessary for control. The HDD 24 stores print jobs (including print settings and print data) received from the PC 30 or the like. Instead of the HDD 24, a nonvolatile memory such as a flash ROM can be used.

  The network interface 27 is a receiving unit that receives a print job. The network interface 27 is an interface for communicating with other devices via the network 18. Here, it is used for connection with PC30. In this embodiment, the print job is described as being transmitted from the PC 30. In addition, for example, the image forming apparatus is provided with a wired interface such as a USB or a wireless interface, You may enable it to receive a print job directly from various terminal devices (for example, USB memory, a portable terminal, etc.). In such a case, these interfaces can be a receiving unit that receives a print job.

  The paper feeding unit 12 conveys the paper to the printing unit 13 according to an instruction from the control unit 11. The paper feed unit 12 has a paper feed tray so that a plurality of papers can be stored. The paper feed tray can also store other film-like print media instead of paper.

  The printing unit 13 prints an image on a printing medium such as paper by a known image forming process such as an electrophotographic method, an electrostatic recording method, or inkjet printing under the control of the control unit 11. In the printing operation, after an image is printed on the print medium conveyed from the paper supply unit 12, the print medium is conveyed to the post-processing device 14. As the printing function, for example, a color printing function such as monochrome / color, an enlargement / reduction function, a single-sided / double-sided printing function, a page allocation function such as 2in1, 4in1, and a function of changing the orientation of an image are provided. Each of these print functions is set as one of the print settings. The maximum image size that can be printed by the printing unit 13 is, for example, A3. The paper feeding unit 12 can naturally store paper of a size that can be printed by the printing unit 13.

  The post-processing device 14 performs various post-processing on the print medium conveyed from the printing unit 13 under the control of the control unit 11. The post-processing function includes, for example, a punch function that opens a punch hole at a predetermined position (binding direction) of the paper, a staple function that stops the predetermined position of the paper with staples, and a folding function that folds the paper in a predetermined folding method. Each of these post-processing functions is set in the print settings.

  The operation panel 15 includes a display for performing various displays, a touch panel, a numeric keypad, a start button, a stop button, and the like, and is used for displaying various information and inputting various instructions. From this operation panel 15, the position of the color patch and the like are input. Of course, the color patch position may be designated from the PC 30.

  The transport unit 16 includes a first transport path 161 that transports the paper taken out from the paper supply unit 12 to the printing unit 13, and a second transport path 161 that transports the paper printed by the printing unit 13 to the post-processing device 14. . A plurality of rollers 161a, 161b, 162a, 162b are provided in the first transport path 161 and the second transport path 161 in order to transport the paper.

The PC 30 is a computer such as a general personal computer, and includes a network interface 27 (not shown), transmits a print job to and from the image forming apparatus, and performs print settings for each print job. For this purpose, a printer driver (program) suitable for the image forming apparatus is installed in the PC 30. The user uses this printer driver to transmit a print job including print settings and a print command to the image forming apparatus together with print data. Here, the print settings include settings used for normal printing, for example, the print position of the image to be printed, the number of copies, the paper size, duplex / single-side designation, color / monochrome designation, and the like. Since these settings are general processes, description thereof is omitted. In the present embodiment, the network 18 including color patch information (described later) connects the PC 30 and the image forming apparatus, and transmits and receives print jobs and other information. As such a network 18, for example, a LAN can be used. Also, a line or a dedicated line that directly connects the PC 30 and the image forming apparatus may be used.

  Next, the color sensor will be described.

  FIG. 3 is a schematic perspective view of the color sensor and a moving unit that moves and rotates the color sensor. 4 and 5 are explanatory diagrams for explaining the arrangement and movement of the color sensor. 4 and 5 are views seen from the printing surface side of the paper.

  As shown in FIG. 4, the color sensor 100 is attached to the color sensor moving unit 110. The color sensor moving unit 110 includes a rail 101 (color sensor lateral position moving unit) fixed at a position that does not hinder paper conveyance, a motor 102 that moves along the rail 101, and a rotating shaft 103 that is rotated by the motor 102. And have. A color sensor 100 is attached to the rotation shaft 103.

  The rotation direction of the color sensor 100 can be freely changed between the direction in which the longitudinal direction of the color sensor 100 is along the conveyance direction of the paper 200 and the direction orthogonal to the rotation direction of the rotation shaft 103.

  A moving mechanism (not shown) for moving the motor 102 along the rail 101 is provided in the rail 101 or in a connection portion with the motor. There are various moving mechanisms such as a belt and pulley, a ball screw, and a linear motor. Any mechanism can be used as long as it can move the motor 102 along the rail 101. The length of the rail 101 is slightly longer than the paper width (here, the width in the direction orthogonal to the conveyance direction (the direction of arrow A in FIG. 3)), so that the color sensor extends over the entire length of the paper width. 100 can be moved. The rail 101 and the internal moving mechanism serve as a color sensor lateral position moving unit. Further, the motor 102 and the rotating shaft 103 serve as a color sensor direction changing unit.

  The rotating shaft 103 is rotated by the motor 102. The movement of the color sensor 100 in the direction on the rail 101 and the rotation by the motor 102 are performed according to a command from the control unit 11.

  The color sensor 100 stores a color line image sensor and a light source (both not shown) in a case. As is well known, a color line image sensor has a plurality of pixels arranged linearly. The length of the color sensor 100 is a direction in which a plurality of pixels of the color line image sensor are linearly arranged, and is a length that enables color measurement by recognizing a color patch. The length of the color sensor 100 may be as long as the width of the paper so that color patches of various positions and sizes can be recognized, but the color patch is usually about 3 to 10 cm. A plurality of colors having a width of about 3 mm to 10 mm are drawn continuously or intermittently. Therefore, it is sufficient that the length of the color sensor 100 (the length capable of recognizing the color) is about 10 cm. For this reason, it is easier to change the direction of the color sensor by moving a sensor of about 10 cm in the paper width direction rather than a long sensor that extends over the entire length of the paper width.

  The light source is a white light source, for example, an LED. Since the inside of the image forming apparatus is dark, a portion on which the color patch is printed is illuminated by this light source so that the color patch can be read by the color line image sensor.

  With the color sensor 100 and the moving unit 110 configured as described above, the color sensor 100 can be moved in a direction orthogonal to the paper transport direction and the direction can be freely rotated with respect to the paper transport direction. Therefore, the color sensor 100 can measure colors at any position on the paper 200 in combination with the movement of the paper 200 in the transport direction.

  The installation position of the color sensor 100 in the image forming apparatus may be anywhere as long as the color patch of the paper 200 printed by the printing unit 13 can be read. For example, the color sensor 100 is provided in the first transport path 161 that transports the paper 200 output from the printing unit 13. Further, the color sensor 100 may be provided, for example, on the transport path at the paper entrance of the post-processing device 14. Thus, if it provides in the post-processing apparatus 14, the post-processing apparatus 14 can be attached as an optional item.

  In the drawing, the color sensor 100 is depicted as a configuration for reading the printing surface of the sheet from above the transport unit 16, but this is a case where the printing unit 13 is configured to print on the upper surface of the sheet being transported. . When the printing unit 13 is configured to print on the lower surface of the paper being conveyed, the color sensor 100 and its moving unit 110 are configured to read the printing surface of the paper from below the conveying unit 16.

  Next, the movement of the color sensor and the position of the color patch will be described.

  The printing positions of the color patches on the paper 200 can be freely arranged in the present embodiment. However, at positions that overlap with the image to be printed, image printing is hindered. For this reason, the normal color patch is printed toward the end of the paper 200 that does not cover the image.

  Therefore, in many cases, the color patch 300 is arranged, for example, as shown in FIG. 4, such that the longitudinal direction of the color patch is along the paper conveyance direction A at the upper end of the paper perpendicular to the paper conveyance direction A. As shown in FIG. 5, the longitudinal direction of the color patch is arranged along the direction perpendicular to the sheet conveying direction A at the sheet end on the leading end side in the sheet conveying direction A.

  In this embodiment, when a color patch is printed on the upper edge of the sheet as shown in FIG. 4, the longitudinal direction of the color sensor 100 (pixel arrangement direction, the same applies hereinafter) is along the sheet conveyance direction A as shown. The color sensor 100 is moved and the direction is changed so as to be in the direction.

  On the other hand, as shown in FIG. 5, when a color patch is printed on the end of the paper in the paper transport direction, the longitudinal direction of the color sensor 100 is perpendicular to the paper transport direction A as shown. Move and change the orientation.

  The printing position of the color patch will be further described. 6 and 7 are explanatory diagrams for explaining the printing positions of the color patches.

  Conventionally, as already described, a color sensor for in-line color measurement is fixed. For this reason, the printing position of the color patch is limited to a position where it can be read by a fixed color sensor. For example, as shown in FIG. 6, it is assumed that the upper end portion in the paper 200 is a conventional color sensor reading position. In that case, if the portion is empty, a color patch may be printed there.

  However, the paper size that can be handled by the image forming apparatus is limited. For example, it is assumed that the size in the vertical direction (longitudinal direction) of the paper 200 is the maximum width of the paper 200 that can be printed. This is usually a direction perpendicular to the paper transport direction A and is limited by the width of the transport path in the image forming apparatus. In such a case, as shown in FIG. 7, when it is desired to output the image 201 using the entire longitudinal direction of the paper 200, the color patch cannot be arranged on the upper part of the image 201 to be printed. For this reason, when printing such an image 201, in order to print a color patch, the color patch 300 is arranged at another place, in this case, next to the image.

  However, if a color sensor for performing in-line color measurement is fixed as in the prior art, in-line color measurement cannot be performed at the position of the color patch 300 shown in FIG.

  In this regard, in the present embodiment, the color patch 300 can be measured in any position on the paper 200. Therefore, if the color patch 300 is arranged at the position shown in FIG. 6, the color sensor 100 is moved so that the longitudinal direction of the color sensor 100 is in the direction along the paper conveyance direction, as in FIG. In-line color measurement is possible just by changing the value. Even in the case where a color patch is printed at the position shown in FIG. 7, in this embodiment, the longitudinal direction of the color sensor 100 moves so as to follow the paper transport direction A as shown in FIG. By changing the orientation, in-line color measurement becomes possible.

  Next, the flow of inline color measurement processing will be described. The inline color measurement processing includes color patch creation in the PC 30, printing of the color patch by the image forming apparatus, and inline color measurement processing of the color patch. FIG. 8 is a flowchart showing a color patch creation procedure in the PC 30. FIG. 9 is a flowchart showing an in-line color measurement process procedure of the image forming apparatus according to the first embodiment.

  With reference to FIG. 8, the color patch creation procedure in the PC 30 will be described. First, the user calls and executes a color patch creation program on the PC 30. The color patch creation program may be a single program or may be incorporated in the printer driver.

  The user then creates a color patch using this program.

  First, the PC 30 receives an input of a color patch position from the user (S1). The position of the input color patch is stored as color patch position information and will be described later as one of the print settings. The input color patch position information specifies the position of the color patch together with its size based on the predetermined position of the designated paper 200 as the origin and the distance from the origin. In general, the origin is, for example, the upper left corner of the sheet 200 in a state where the image is upright. Further, the drawing start position of the color patch is designated using the X and Y coordinates where the horizontal direction is the X coordinate and the vertical direction is the Y coordinate. The vertical and horizontal sizes of the color patch are designated as the horizontal (X direction) and vertical (Y direction) length of the color patch from the drawing start position. Such designation of the position is the same as that used when designating the arrangement of images in normal printing. Therefore, referring to FIGS. 6 and 7, regardless of the size and orientation of the paper sheet 200, the upper left corner of the paper sheet 200 is the origin O when the image is upright.

  Next, an instruction for color patch color arrangement is received (S2). The color patch coloration instruction is, for example, to allow the user to select from among color patches whose colors and sizes are determined in advance, or to use color patches arbitrarily created by the user. For each color of the color patch, the position and size of each color are specified in the color patch together with the color information (details will be described later).

  Subsequently, the PC 30 creates printing data for the input color patch (S3).

  Subsequently, the created color patch data for printing is superimposed on the image to be printed in the print job at the position input in S1, thereby generating an image with color patches (S4).

  Subsequently, the PC 30 describes the position input to the image in S1 in the print job, the color scheme input in S2 and the position in each color patch, and the color information of each color as color patch information in the print settings. Then, the images with the color patches are combined into one print job (S5).

  Then, the PC 30 transmits a print job including the image with the color patch in response to a print execution instruction from the user (S6). Thereby, the process in PC30 is complete | finished. Note that the image forming apparatus 10 prints an image with a color patch by instructing the printing execution from the PC 30 thereafter.

  Here, an example of a color patch created by the PC 30 will be described. FIG. 10 is an explanatory diagram illustrating an example of a color patch.

  A color patch usually has a plurality of different colors of the same size. For example, basic colors for color printing such as green (G), blue (B), red (R), cyan (C), magenta (M), yellow (Y), and black (K). In addition, colors that are often used in images or colors that look interesting may be used. A monochromatic color scale may be used. The color arrangement in such a color patch may be arbitrarily determined by the user, and any color may be used. Each color of the color patch also has color information so that the color can be discriminated numerically. For example, it is defined by RGB or CMYK gradation values or Lab color space values.

  Further, the position and size of each color in the color patch must be determined in advance. Here, the long side direction (direction in which individual colors are continuous) of the color patch is defined as the X direction, and the short side direction (direction corresponding to one color) is defined as the Y direction. The size of each color is x × y. For example, when each color is arranged in a square shape of 5 mm × 5 mm, assuming that one end of the illustrated color patch is 0, 0 to 5 mm is green (G), 5 to 10 mm is blue (B), and 10 to 15 mm is red (R ) Cyan (C) from 15 to 20 mm, 20 to 25 mm magenta (M), 25 to 30 mm yellow (Y), 30 to 35 mm black (K), etc., and the position of each color and the color information of each color are associated with each other. Keep it.

  These are necessary in order to know what color the color patch originally was and where the color was when the color patch was measured in-line and color correction was performed based on the result.

  When creating a color patch, it is not necessary to attach the color patch to all sheets. For example, when printing hundreds or thousands of identical images, an image with color patches may be printed every tens or hundreds. In such a case, for example, an image with a color patch is generated in advance using an image in a print job to be executed, and several tens of sheets are printed during execution of a normal print job (image without a color patch). Alternatively, an image with a color patch may be printed every time or every several hundred sheets by interruption processing or the like.

  Next, a processing procedure on the image forming apparatus side will be described with reference to FIG.

  First, the CPU 21 in the image forming apparatus starts an inline color measurement processing program. When a print job is received, print settings and image data to be printed are extracted from the print job and stored in the HDD 24 or the like (S11).

  Subsequently, the CPU 21 analyzes the print settings and determines whether there is a color patch print instruction (S12). If there is no color patch printing instruction in S12, normal printing is performed (S100).

  On the other hand, if there is a color patch print instruction (S12: YES), the CPU 21 extracts the color patch information from the print settings (S13). The color patch information extracted at this time includes at least the position information of the color patch. For this reason, the network interface 27 and the control unit 11 that receive a print job including color patch position information function as a color patch position information receiving unit.

  When the image forming apparatus automatically performs color correction, the color patch information includes the position of each color in the color patch and the color information at that position.

  Information on these color patches is temporarily stored in the RAM 23.

  Subsequently, the CPU 21 analyzes where the color patch comes on the conveyed paper 200 from the position information of the color patch (S14). At this time, the coordinate system in the paper 200 is converted into a coordinate system unique to the image forming apparatus, and the position and orientation of the color patch with respect to the conveyance direction are determined. The coordinate system unique to the image forming apparatus is, for example, an X coordinate as a transport direction and a Y coordinate as a direction orthogonal to the transport direction. Of course, other coordinate systems may be used.

  Subsequently, the color sensor 100 is moved and rotated according to the determined position and orientation of the color patch (S15). In other words, the color sensor 100 is moved to the position of the color patch at a position perpendicular to the paper conveyance direction, and the color sensor 100 is arranged so that the longitudinal direction of the color sensor 100 is along the longitudinal direction of the color patch on the paper. Rotate the to change the orientation. As a result, the color sensor 100 can read the color patch at the position and orientation corresponding to the position where the color patch is printed and the orientation thereof.

  Thereafter, the CPU 21 executes printing according to the print settings (S16). The printing operation itself is the same as normal printing. At this time, the image containing the color patch is printed together with the color patch.

  Subsequently, the CPU 21 reads the printed color patch with the color sensor 100 and performs colorimetry (S17). The read result is temporarily stored in the RAM 23 or stored in the HDD 24. Then, the CPU 21 performs color correction if necessary using the result of reading the color patch (S18).

  Thereafter, the CPU 21 determines whether all the images have been printed (S19). If printing of all the images has not been completed, the CPU 21 returns to S16 and continues the printing operation. On the other hand, if all the images have been printed, the process ends.

  In the color correction in S18, for example, when there is a difference between the value of each color in the color patch that is known in advance and the value measured inline, the color correction is performed so as to fill the difference. This color correction is not performed only in the image forming apparatus, but the result of in-line color measurement is transmitted to the PC 30, and the image data subjected to color correction from the PC 30 is retransmitted to the image forming apparatus for printing. It may be. In this case, if the color information of each color of the color patch is known on the PC side (that is, the user), it is not necessary to transmit it to the image forming apparatus. Note that these color correction processes may be performed by conventional methods and are not particularly limited.

  In the above procedure, images with color patches are printed for all images. Instead, for example, when thousands of sheets are printed, images with color patches are printed every 100 sheets. In this way, the color measurement may be performed only for the paper 200 on which the color patch is printed.

  In the above procedure, the color patch is created by the PC 30 and the position information of the color patch is transmitted to the image forming apparatus. Instead, the position information of the color patch is formed from the operation panel 15 by the image formation. You may enter directly into the device. In this case, the control unit 11 that receives the position information of the color patch input from the operation panel 15 functions as a color patch position information receiving unit.

  According to the above Embodiment 1, the following effects are produced.

  In the first embodiment, the color sensor 100 is movable in a direction orthogonal to the paper conveyance direction, and the longitudinal direction of the color sensor 100 is either a direction along the paper conveyance direction or a direction orthogonal to the paper conveyance direction. It was decided to change so that. As a result, the color patch can be read from any portion on the paper 200 being conveyed. Accordingly, in-line color measurement can be performed wherever the color patch is placed (printed) on the paper 200, and the user does not have to worry about the position of the color sensor 100 provided in the image forming apparatus. The color patch can be arranged in accordance with the image to be printed, and the inline side color and the resulting color correction can be performed.

  The orientation of the color sensor 100 is such that the longitudinal direction of the color sensor 100 has an angle other than perpendicular to the paper transport direction, as well as the direction along the paper transport direction or the direction orthogonal to the paper transport direction. May be. That is, even when the color patch is disposed obliquely with respect to the paper edge, this embodiment can cope with the problem by controlling the rotation of the motor. Further, the printing position of the color patch is not limited to the position shown in FIG. 6 or 7, and may be anywhere on the paper as described above.

[Embodiment 2]
In recent image forming apparatuses, the printing speed is high, and there is a possibility that the image reading speed at the time of color measurement is not in time for the paper conveyance speed. Therefore, the second embodiment is a processing mode for performing inline color measurement with priority over color measurement. Here, a processing procedure in the second embodiment will be described. The apparatus configuration of the second embodiment is the same as that of the first embodiment. The color patch creation process in the PC 30 is the same as that in the first embodiment. Therefore, these descriptions are omitted.

  FIG. 11 is a flowchart illustrating an inline color measurement processing procedure of the image forming apparatus according to the second embodiment.

  Also in the second embodiment, the processes of S11 to S15 are the same as those of the first embodiment. That is, the CPU 21 receives the print job (S11), and when there is a color patch (S12: YSE), extracts the color patch information (S13), analyzes where the color patch comes on the paper 200 (S14), The color sensor 100 is moved and rotated to that position (S15).

  Thereafter, in the second embodiment, the CPU 21 determines whether or not it is necessary to stop the sheet conveyance (S20). This determination is made from the size of each color in the color patch information extracted in S13, the sheet conveyance speed unique to the apparatus, and the time required for the color sensor 100 to read. The sheet conveyance speed V is a speed unique to the image forming apparatus and is known in advance. Similarly, the time t required for reading by the color sensor 100 is unique and known. On the other hand, the size of each color of the color patch is determined when the color patch is created on the PC 30 side, and is horizontal x x vertical y (see FIG. 10 of the color patch creation process in the PC 30 of the first embodiment). .

  From these, if the time for one color in the color patch to pass through the color sensor 100 is shorter than the time t required for reading by the color sensor 100, it may be determined that the conveyance of the paper 200 is stopped. That is, when the following expression (1) or (2) is satisfied, it is determined that the conveyance of the sheet 200 is stopped.

When the longitudinal direction (X direction) of the color patch is the same as the paper transport direction (when the color patch is arranged as in FIG. 4),
x / V <t (1)
When the longitudinal direction (X direction) of the color patch is the direction perpendicular to the paper transport direction (when the color patch is arranged as in FIG. 5),
y / V <t (2)
It becomes.

  If it is determined in S20 that there is no need to stop the conveyance (S20: NO), the process proceeds to printing (S16) and the subsequent processing is continued. In this case, after printing, it is determined in S22 that the conveyance flag is off (S22: NO), and color measurement of the color patch (S27) is performed without stopping the sheet conveyance. This is the same processing as in the first embodiment.

  On the other hand, if it is determined in S20 that the conveyance stop is necessary (S20: YES), the CPU 21 turns on the conveyance stop flag (S21). Thereafter, the process proceeds to printing (S16) and the subsequent processing is continued. In this case, since the CPU 21 determines that the transport flag is on in S22 after printing (S22: YES), the CPU 21 temporarily stops the paper transport and performs color measurement using the color patch (S23). After the color measurement (S23), the CPU 21 resumes paper conveyance (S24) and outputs printing paper.

  After the color measurement, the CPU 21 performs color correction (S18) as necessary. Thereafter, the process returns to S12 until all printing is completed, and the processing is continued.

  Here, when stopping paper conveyance in S23, referring to FIG. 1, for example, after printing, the roller 161a at the front end side in the paper conveyance direction in the first conveyance path 161 is stopped (even if it is stopped before printing). good). As a result, even if the printed paper 200 is conveyed by the roller 161b at the rear end in the paper conveyance direction, since the roller 161a is stopped, the paper 200 hits the roller 161a and stops. That is, the roller 161a serves as a stopper. The roller 161a and the color sensor 100 are adjusted in advance to a position where the color sensor 100 can read the color patch in a state where the paper 200 is stopped by the roller 161a.

  The rollers 161a and 161b are arranged so as to be longer than the length in the transport direction of the paper 200, or the roller 161b is idled (the paper is not sent out) while the roller 161a is stopped. This is because if the roller 161b is rotating and the paper 200 is pushed out while the roller 161a is stopped, the leading edge side of the paper 200 is held by the roller 161a, so that it may be wrinkled when pushed from behind. Because there is. This roller 161a functions as a conveyance stop unit.

  In addition, in order to stop the sheet conveyance and stop in S23, for example, a stopper that stops the sheet 200 at a position where the color patch can be read by the color sensor 100 may be disposed (in this case, the stopper is a conveyance stop unit). Become). Further, the sheet conveyance can be temporarily stopped by using a sheet reversing device (not shown) used for duplex printing (in this case, the sheet reversing device serves as a conveyance stopping unit). In this case, since the paper 200 that has entered the paper reversing device is conveyed in a direction opposite to the incoming direction (referred to as switchback), there is a time to pause at that time. If the color sensor 100 is arranged so that the pause time can be used, the color patch can be read during the pause time.

  In the above-described procedure, the conveyance of the paper is stopped. However, if the image forming apparatus is capable of changing the conveyance speed of the paper 200, the conveyance speed of the paper 200 is set instead of stopping the conveyance of the paper 200. You may change so that it may become below the speed which the color sensor 100 can read a color patch reliably. In this case, the control unit 11 that controls to delay the conveyance speed of the sheet 200 functions as a conveyance delay unit.

  In the second embodiment, as in the first embodiment, it is not necessary to measure the color by printing color patches on all the sheets 200. For example, the number of sheets is several tens, hundreds, or thousands. Color measurement may be performed by printing about one color patch for a plurality of sheets, such as one sheet. In this case, in the second embodiment, it is only necessary to stop or delay the sheet conveyance on the sheet 200 on which the color patch is printed. Therefore, when the color measurement is performed by printing about one color patch for each of a plurality of sheets, it is possible to finish the entire printing earlier than the case of measuring all the sheets 200.

  Also in the second embodiment, the position of the color patch may be input from the operation panel 15 as in the first embodiment. Further, as in the first embodiment, the position of the color patch may be arranged anywhere on the paper.

  According to the second embodiment described above, in addition to the effect of being able to read a color patch arranged at an arbitrary position on the paper 200 as in the first embodiment, the following effects are obtained.

  In the second embodiment, when the time required for reading the color patch by the color sensor 100 is slower than the conveyance speed of the paper 200, the conveyance of the paper 200 is temporarily stopped or the conveyance is delayed. For this reason, it is possible to reliably read the color patch.

  Although the embodiment to which the present invention is applied has been described above, the present invention is not limited to the above-described embodiment. The scope of the present invention is determined by the configurations described in the claims, and various modifications are also included in the scope of the present invention.

10 image forming apparatus,
11 Control unit,
12 Paper feeder,
13 Printing department,
14 post-processing equipment,
15 Operation panel,
16 transport section,
18 network,
21 CPU,
22 ROM,
23 RAM,
24 HDD,
27 Network interface,
30 PC,
100 color sensor,
101 rails,
102 motor,
103 rotation axis,
110 Color sensor moving part,
200 paper,
300 color patches.

Claims (6)

A printing unit that prints an image including a color patch in which a plurality of colors are arranged continuously or intermittently on paper;
A color patch position information receiving unit for receiving the position of the color patch on the paper;
A plurality of pixels linearly arranged in the longitudinal direction, and a color sensor that reads the color patch by the plurality of pixels ;
A color sensor moving unit for moving the color sensor to an arbitrary position on the paper and changing the orientation of the color sensor;
Based on the position of the color patch received by the color patch position information receiving unit, the longitudinal direction of the color sensor is the same as the direction in which a plurality of colors of the color patch printed on a sheet are arranged. the by changing the moving is not Rutotomoni facing the color sensor, and a control unit for the color patch read by the color sensor,
An image forming apparatus comprising: The image forming apparatus according to claim 1 , wherein the color sensor has the plurality of pixels arranged longer than the length of the color patch .   2. The apparatus according to claim 1, further comprising a conveyance stop unit that temporarily stops conveyance of the sheet or a conveyance delay unit that delays conveyance of the sheet so that the color sensor can read the color patch during conveyance of the sheet. Or the image forming apparatus according to 2; A printing unit that prints an image including a color patch in which a plurality of colors are arranged continuously or intermittently on paper;
A color patch position information receiving unit for receiving the position of the color patch on the paper;
A plurality of pixels linearly arranged in the longitudinal direction, and a color sensor that reads the color patch by the plurality of pixels ;
A color sensor moving unit for moving the color sensor to an arbitrary position on the paper and changing the orientation of the color sensor;
An image forming apparatus control method comprising:
Receiving the position of the color patch by the color patch position information receiving unit;
Received based on the position of the color patch, the longitudinal direction of the color sensor, so that the same direction as the direction in which the plurality of colors are arranged in the color patches printed on paper, Before moving the color sensor comprising the steps of: Ru to change the orientation with,
Causing the color sensor to read the color patch;
A control method for an image forming apparatus, comprising: 5. The method of controlling an image forming apparatus according to claim 4 , wherein the color sensor has the plurality of pixels arranged longer than the length of the color patch . The step of causing the color sensor to read the color patch includes:
6. The control of an image forming apparatus according to claim 4, further comprising a step of temporarily stopping or delaying the conveyance of the sheet so that the color sensor can read the color patch during the conveyance of the sheet. Method.