JP2023084388A - Image forming apparatus, method for controlling image forming apparatus, and program for controlling image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that can perform color adjustment without stopping sheet conveyance.SOLUTION: A method executed by an image forming apparatus includes: a step of acquiring a travel speed in the vertical direction relative to a sheet conveyance direction (S625); a step of arranging, as image for adjustment, trigger marks corresponding to the positions of patches for measurement performed by an arranged in-line sensor (S670); a step of acquiring an image forming condition and a measurement condition for color adjustment (S675); a step of forming the images for adjustment (patches and trigger marks) based on the acquired conditions (S680); a step of measuring the patches being the images for adjustment by an inline sensor to acquire a measured value (S685); and a step of calculating an adjustment value by using the acquired measured value (S690).SELECTED DRAWING: Figure 6

Description

TECHNICAL FIELD The present disclosure relates to control of image forming devices, and more particularly to color adjustment of image forming devices capable of color printing.

Since the color reproduction of an output from an image forming apparatus or other printer capable of color printing depends on the output environment, color adjustment may be required under the output environment. For such color adjustment, for convenience, an in-line sensor (colorimeter) provided in the image forming apparatus is used for color adjustment without using an external colorimeter.

Regarding measurement using an in-line sensor, for example, Japanese Patent Application Laid-Open No. 2016-48309 (Patent Document 1) describes, "One image detection unit is calibrated by another image detection unit to improve the image detection accuracy, and at the time of calibration, there is no error. "suppress paper generation" technology is disclosed (paragraph 0007). The technique disclosed in Japanese Patent Application Laid-Open No. 2002-200003 is "a first image detection unit for detecting an image on a transfer sheet on which an image is formed and conveyed, and a detection unit separate from the first image detection unit. a detection unit calibration mode for calibrating the first image detection unit using the image detection result of the second image detection unit; In the calibration mode, the transfer paper transport speed during image reading by the second image detection unit is changed to a transfer paper transport speed different from the normal transfer paper transport speed during image formation, and the first image detection unit and the second image detection unit By having a control unit that calibrates the first image detection unit based on the reading result of the same image in , the accuracy of the image detection unit is improved without increasing waste paper during detection” ([ Summary]).

However, color measurement with an in-line sensor (colorimeter) requires a certain amount of time. Therefore, the normal paper transport speed of the image forming apparatus cannot be used for this measurement, and in order to measure the color patches, it is necessary to temporarily stop the transport of the paper or reduce the speed of the measurement. Therefore, it is desired to measure color patches with an in-line sensor (colorimeter) without temporarily stopping or slowing down paper transport.

For example, Japanese Patent Application Laid-Open No. 2018-197775 (Patent Document 2) discloses an image forming apparatus that "appropriately performs colorimetry of an adjustment image using long paper." The image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 2002-200001 describes that "a speed at which the transfer sheet is conveyed when forming an image, which is higher than the speed set for conveying the transfer sheet when the image is read by the colorimetry unit. A transport speed lower than the first transport speed and determined as a speed for transporting the transfer paper when the image is read by the colorimetry unit is a second transport speed. In the adjustment mode in which paper is used as the transfer paper and the adjustment image is read, the image forming unit and the transfer unit are controlled so that the adjustment image is formed on the transfer paper conveyed at the second conveying speed, and the image is formed on the transfer paper. The adjusted image for adjustment is read while the transfer paper is conveyed at the second conveying speed (see [Summary]). According to the technique disclosed in Japanese Patent Application Laid-Open No. 2002-200001, "Even if the long paper is conveyed while being sandwiched by both the image forming section and the colorimetric section, the second conveying speed is the same for image forming and reading. , and it is possible to appropriately perform colorimetry of the adjustment image using the long sheet" (paragraph 0023).

JP 2016-48309 A JP 2018-197775 A

According to the technique disclosed in Patent Document 2, when the transfer paper is long, the image for adjustment is extended in the sub-scanning direction, and the colorimetry unit reads the image without lowering the conveying speed of the transfer paper. However, there is a need for a technique for performing colorimetry even when the colorimetry unit moves in the direction perpendicular to the conveying direction of the transfer paper.

The present disclosure has been made in view of the background as described above, and one of the objects according to a certain aspect is to reduce paper conveyance when a colorimetry unit moves in a direction perpendicular to the paper conveyance direction. To provide a technique capable of measuring without temporarily stopping or slowing down.

An image forming apparatus according to an embodiment includes a transport mechanism for transporting a print medium, an image forming unit for forming an image on the print medium, and a print medium for scanning one or more color patches formed on the print medium. control the image forming unit to form one or more color patches on the print medium according to the inline sensor movable in the direction perpendicular to the transport direction of the print medium, the transport speed of the print medium, and the moving speed of the inline sensor and a control unit.

In one aspect, the color patches are arranged according to information on the print medium.

In one aspect, the information includes paper type and size.

In one aspect, the in-line sensor includes a spectrophotometer.

In one aspect, the in-line sensor further includes a trigger sensor.

In one aspect, the image forming apparatus further includes a trigger sensor provided separately from the in-line sensor.

In one aspect, the difference between the transport speed of the transport mechanism when forming the one or more color patches on the print medium and the transport speed when forming the image other than the one or more color patches on the print medium is predetermined. within the specified range.

In one aspect, the image forming section further forms trigger marks at predetermined positions relative to the positions of the one or more color patches.

In one aspect, the placement of the trigger marks is determined according to the transport speed of the print medium and the moving speed of the in-line sensor.

In one aspect, the controller makes color adjustments based on signals output from the in-line sensor by scanning one or more color patches.

According to another embodiment, a method of controlling an image forming apparatus is provided. The control method includes the steps of transporting a print medium, forming an image on the print medium, and scanning one or more color patches formed on the print medium in a direction perpendicular to the transport direction of the print medium. and moving the in-line sensor. Forming the image includes forming one or more color patches on the print medium in response to the transport speed of the print medium and the speed of movement of the in-line sensor.

According to yet another embodiment, a program is provided for controlling an image forming device. The program instructs an image forming apparatus to perform the steps of transporting a print medium, forming an image on the print medium, and scanning one or more color patches formed on the print medium. and moving the in-line sensor in the desired direction. Forming the image includes forming one or more color patches on the print medium in response to the transport speed of the print medium and the speed of movement of the in-line sensor.

The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the invention taken in conjunction with the accompanying drawings.

1 is a diagram showing the appearance of an image forming apparatus 100 according to an embodiment; FIG. FIG. 10 is a diagram showing the appearance of an image forming apparatus 200 according to another embodiment; 2 is a block diagram showing an overview of the hardware configuration of image forming apparatuses 100 and 200; FIG. 4 is a diagram illustrating an example configuration of an in-line sensor 400 according to certain aspects; FIG. FIG. 10 is a diagram illustrating an example configuration of an in-line sensor 500 according to another aspect; 3 is a flowchart showing a part of processing executed by CPU 310 of image forming apparatuses 100 and 200; FIG. 7 is a diagram representing one manner in which patches are placed on a strip of paper 700 when an in-line sensor 400 is used; FIG. 4A is a representation of one manner in which patches are placed on a sheet when an in-line sensor 400 is used. FIG. 10 is a diagram representing one manner in which patches are placed on a strip of paper 900 when an in-line sensor 500 is used; FIG. 10 is a diagram showing another aspect of how patches are arranged on the long sheet of paper 1000 when an in-line sensor 400 is used;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are given the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

An outline of an image forming apparatus according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a diagram showing the appearance of an image forming apparatus 100 according to an embodiment. FIG. 2 is a diagram showing the appearance of an image forming apparatus 200 according to another embodiment. The image forming apparatus 200 can also handle printing on so-called long paper.

Referring to FIG. 1, image forming apparatus 100 includes a paper feeding unit 110, an image forming unit 120, inline scanners 130 and 140, an inline sensor 150, a paper discharging unit 160, a conveying unit 170, and a control unit. 190.

The paper feed unit 110 receives a supply of paper or other print media from the outside. The paper feeding unit 110 supplies the print medium to the image forming unit 120 via the conveying unit 170 .

The image forming unit 120 contains yellow (Y), magenta (M), cyan (C), and black (K) toners. The image forming unit 120 forms an image on the print medium based on image data generated from data provided to the image forming apparatus 100 .

The in-line scanners 130 and 140 optically read the image formed on the print medium by the image forming section 120 and output a signal according to the reading result. The output signal is input to the control section 190 .

The in-line sensor 150 detects patches of color placed on the print medium. A detection result is transmitted to the control unit 190 .

The paper ejection unit 160 receives a print medium on which an image is formed and ejected. The paper discharge unit 160 may be configured to be discontinued with a different cassette for each job.

The conveying unit 170 operates according to a command from the control unit 190 and conveys the print medium from the paper feeding unit 110 to the paper discharging unit 160 .

Control unit 190 controls the operation of image forming apparatus 100 . In one aspect, controller 190 is implemented by one or more processors that execute instructions.

Referring to FIG. 2, image forming apparatus 200 includes paper feeding unit 110, image forming unit 120, inline scanners 130 and 140, inline sensor 150, paper discharging unit 160, conveying unit 170, and control unit. 190. Paper feed unit 110 includes paper feed rollers 210 . Paper ejection section 160 includes paper ejection rollers 220 .

Paper feed unit 110 , image forming unit 120 , inline scanners 130 and 140 , inline sensor 150 , paper discharge unit 160 , and control unit 190 of image forming apparatus 200 are connected to paper feed unit 110 of image forming apparatus 100 . , the image forming section 120, the in-line scanners 130 and 140, the in-line sensor 150, the paper discharge section 160, and the control section 190 implement the same functions as those implemented respectively.

Further, the paper feed roller 210 receives a roll of long paper prepared in a roll shape as a print medium. The long paper is sequentially sent out by the transport unit 170 and taken up by the paper discharge roller 220 .

A specific configuration of the image forming apparatuses 100 and 200 will be described with reference to FIG. FIG. 3 is a block diagram showing an overview of the hardware configuration of image forming apparatuses 100 and 200. As shown in FIG. The image forming apparatuses 100 and 200 each include a CPU (Central Processing Unit) 310, a RAM 320, a storage section 330, an operation section 340, a display section 350, a communication section 360, an image forming section 120, an image reading section 370, and a and Image reading unit 370 includes inline scanners 130 and 140 and inline sensor 150 .

CPU 310 controls operations of image forming apparatuses 100 and 200 . RAM 320 temporarily holds data externally received by image forming apparatuses 100 and 200 or data generated by CPU 310 .

Storage unit 330 permanently retains data externally received by image forming apparatuses 100 and 200 or data generated by CPU 310 . In one aspect, storage unit 330 is realized by a non-volatile storage device such as a hard disk device or an SSD (Solid State Drive). In one aspect, storage unit 330 stores various programs including a color adjustment patch creation program, a color adjustment execution program, an in-line sensor measurement program, and a color adjustment calculation program.

Operation unit 340 accepts commands input by users of image forming apparatuses 100 and 200 . In one aspect, operation unit 340 is realized as a software switch such as a touch panel, or as a hardware switch such as a button or toggle switch. In another aspect, operation unit 340 may be configured as a detachable operation panel, such as a tablet terminal.

Display unit 350 displays an operation screen or status of image forming apparatuses 100 and 200 . The operation screen displays operating conditions input by the user of the image forming apparatuses 100 and 200, including color adjustment, density, and other printing conditions. The status of image forming apparatuses 100 and 200 includes information indicating the current status of image forming apparatuses 100 and 200 . In one aspect, the display unit 350 is realized as a liquid crystal monitor or an organic EL (Electro-Luminescence) monitor. In another aspect, the display unit 350 can be realized as a detachable monitor device like a tablet terminal.

Communication unit 360 communicates with a personal computer or other information communication device capable of communicating with image forming apparatuses 100 and 200 . The form of communication is not particularly limited. The information communication device transmits a print command to image forming devices 100 and 200, and upon receiving the print command, image forming devices 100 and 200 execute a predetermined print operation. In another aspect, the information communication device can also function as an external monitor device that displays the status of image forming devices 100 and 200 .

The image reading unit 370 measures the patches placed on the print medium and performs color adjustment and confirmation of accuracy. In one aspect, the in-line sensor 150 reads patches formed on color-printed paper and outputs a signal according to the reading result. The signal is input to CPU 310 . The CPU 310 uses the signal to adjust each color or check the accuracy.

A specific configuration of the in-line sensor 150 will be described with reference to FIGS. 4 and 5. FIG. The in-line sensor 150 can move in a direction perpendicular to the paper transport direction. The in-line sensor 150 measures color patches placed on the paper in the main scanning direction.

FIG. 4 is a diagram illustrating an example configuration of an in-line sensor 400 according to certain aspects. FIG. 5 is a diagram illustrating an example configuration of an in-line sensor 500 according to another aspect.

Referring to FIG. 4, in-line sensor 400 includes colorimeter 410 and trigger sensor 420 . The colorimeter 410 performs spectroscopic measurements to obtain color values (L*a*b, XYZ, density) similar to those obtained by an external colorimeter. Trigger sensor 420 detects a trigger mark for the measurement reference point of in-line sensor 400 . Since the trigger sensor 420 moves in the same manner as the colorimeter 410, it can detect trigger marks arranged in the main scanning direction.

Referring to FIG. 5, in-line sensor 500 includes colorimeter 410 . Trigger sensor 420 is located separately from in-line sensor 500 . With this configuration, the colorimeter 410 can move in the direction perpendicular to the paper transport direction and measure color patches arranged on the paper in the main scanning direction. On the other hand, the trigger sensor 420 is fixed to the image forming apparatuses 100 and 200 and does not move, so it detects a trigger mark arranged at a predetermined position on the paper in the main scanning direction.

[Control structure]
The control structure of image forming apparatuses 100 and 200 will be described with reference to FIG. FIG. 6 is a flow chart showing part of the process executed by CPU 310 of image forming apparatuses 100 and 200. As shown in FIG. Note that in other aspects, the processing may be implemented by circuit elements or other hardware.

In step S610, CPU 310 detects, based on the setting input given to operation unit 340, that an instruction for color adjustment has been issued. For example, when a user of image forming apparatuses 100 and 200 inputs a color adjustment execution instruction, CPU 310 starts a color adjustment operation. The color adjustment instruction is given, for example, at the timing when the image forming apparatuses 100 and 200 start operating, before the image forming apparatuses 100 and 200 finish printing certain content and start printing other content. In other aspects, CPU 310 may be configured to automatically perform color adjustments at preset timings.

In step S615, CPU 310 acquires the color to be adjusted and the number of colors based on the setting input. For example, when a color printing instruction is input, CPU 310 can set yellow, magenta, cyan, and black as adjustment targets. In another aspect, CPU 310 may select a user-specified color for color adjustment.

At step S620, CPU 310 acquires the paper transport speed of the output condition. For example, CPU 310 selects a speed corresponding to the selected print quality from a plurality of paper transport speeds prepared in advance according to print quality. A plurality of paper transport speeds are held in the storage unit 330 or the RAM 320 .

In step S625, CPU 310 acquires the moving speed in the direction perpendicular to the paper transport direction as the moving speed of inline sensors 400 and 500. FIG. That is, the CPU 310 calculates the speed at which the paper as the print medium is traversed while the paper is conveyed. This speed is set at least as a speed at which the in-line sensor 150 can transversely scan the print target area of the paper while the paper transport speed is the normal printing speed. In one aspect, the speed of movement is set to ensure the shortest amount of time that the in-line sensor 400, 500 can manipulate color.

In step S630, CPU 310 calculates an arrangement rule in the main scanning direction for patches for measurement by inline sensors 400 and 500. FIG. For example, CPU 310 determines whether to place the patches in a line or diagonally across the printable area of the paper.

In step S635, CPU 310 determines whether the paper type is long paper. This determination is based on instructions given by the user of the image forming apparatuses 100 and 200, or the type of paper feed mechanism (sheet cassette or paper feed roller) attached to the paper feed unit 110. done. When CPU 310 determines that the paper type is long paper (YES in step S635), CPU 310 switches control to step S640. Otherwise (NO in step S635), CPU 310 switches control to step S645.

In step S640, CPU 310 acquires the paper size. For example, CPU 310 acquires width information of roll paper set on paper feed roller 210 from a sensor (not shown) of paper feed unit 110 . In another aspect, CPU 310 acquires the size (width information) of the paper being conveyed based on the long paper information set in operation unit 340 .

In step S645, CPU 310 acquires the paper size. For example, CPU 310 acquires the size of the paper being transported based on the type of paper cassette used in paper feeding unit 110 or the paper information set in operation unit 340 .

In step S650, CPU 310 calculates the number of patches that can be arranged on one sheet of paper.

In step S655, CPU 310 determines whether or not the adjustment colors can be arranged on one sheet of paper. When CPU 310 determines that the adjustment colors can be arranged on one sheet of paper (YES in step S655), it switches control to step S660.

In step S660, CPU 310 determines the placement of patches in the main scanning direction for measurement by inline sensors 400 and 500. FIG. For example, in the case of long paper, if the length of one printed matter (feed amount in the transport direction) is 5 m and the width of the long paper is 1 m, the CPU 310 calculates the distance of the long paper in the scanning direction ( = 1 m) and the operability of the in-line sensors 400, 500, the in-line sensors 400, 500 calculate how many scans are possible. For example, when the CPU 310 determines that 10 scans are possible, the print target area (for example, 4.5 m) of the length (=5 m) in the transport direction is equally divided into 10, and the arrangement interval of each color patch is calculated. can be calculated as 0.45 m. On the other hand, when the image forming apparatus 100 conveys a sheet as a print medium, the CPU 310 determines whether the inline sensors 400 and 500 are 1 sheet based on the width of the sheet and the scanning speed of the inline sensors 400 and 500. If the CPU 310 determines that 8 scans are possible during sheet transport, the CPU 310 may determine that 8 measurement patches (color patches) can be placed in the scanning direction. In this case, the CPU 310 can divide the length of one sheet of paper in the transport direction into eight equal parts, and determine the positions of the patches so that the eight patches are evenly spaced.

In step S665, CPU 310 determines the arrangement of patches in the main scanning direction for measurement by inline sensors 400 and 500 by dividing them into a plurality of pages. For example, if color adjustments are made for each of a plurality of colors, CPU 310 may determine to place the patches on one sheet of paper for each color.

In step S670, CPU 310 arranges a trigger mark corresponding to the position of the patch for measurement by arranged inline sensors 400, 500 as an adjustment image.

In step S675, CPU 310 acquires image forming conditions and measurement conditions for color adjustment. The image forming condition is a profile type which is a color management condition, or a spot color table type when the adjustment color is a spot color. The measurement conditions include settings of light source conditions (M0, M1, M2) and the like.

In step S680, CPU 310 forms an adjustment image (each patch and trigger mark) on paper based on the acquired conditions.

In step S685, CPU 310 measures the patch of the image for adjustment with in-line sensors 400 and 500 to obtain the measured value.

In step S690, CPU 310 calculates an adjustment value using the acquired measurement value.

In step S695, CPU 310 registers the adjustment value. For example, CPU 310 registers the adjustment value in RAM 320 or storage unit 330 . Thereafter, printing by image forming apparatuses 100 and 200 is performed in a state in which the registered adjustment values are reflected.

[Specific example of image for adjustment]
An example of the adjustment image will be described with reference to FIGS. 7 and 8. FIG. FIG. 7 is a diagram illustrating one manner in which patches are placed on a strip of paper 700 when inline sensor 400 is used. FIG. 8 is a representation of one manner in which patches are placed on a sheet when an in-line sensor 400 is used.

Referring to FIG. 7, long paper 700 is conveyed in the direction of arrow 720 . In-line sensor 400 moves in the direction of arrows 710,711. That is, the in-line sensor 400 reciprocates in a direction perpendicular to the direction in which the long paper 700 is conveyed.

In one aspect, image forming section 120 forms a plurality of trigger marks 730 , a plurality of first color patches 740 , and a plurality of second color patches 750 on long paper 700 . In the example shown in FIG. 7, the trigger marks 730 and the first color patches 740 are formed at eight locations across the long sheet of paper 700 .

While the long paper 700 is being conveyed in the direction of arrow 720, the in-line sensor 400 moves in the direction of arrow 710 at a predetermined speed. This speed is set, for example, so that the inline sensor 400 can measure the first color patches 740 formed at eight locations while the inline sensor 400 reaches from the left end to the right end of the long paper 700 . When the in-line sensor 400 detects the first trigger mark 730, it assumes that a color patch will appear after that, and stands by in the measurement mode.

In-line sensor 400 measures the color of first color patch 740 at the first location. The measured value is input to CPU 310 . The in-line sensor 400 continues to move according to the conveying speed of the long paper 700, and when the trigger mark 730 at the second position is detected, the measurement of the first color patch 740 at the second position is awaited. The in-line sensor 400 outputs a measured value when it detects the second first color patch 740 . Inline sensor 400 measures the color of eight first color patches while moving in the direction of arrow 710 .

When in-line sensor 400 detects trigger mark 760 , it outputs a signal indicating the detection to CPU 310 . CPU 310 detects that in-line sensor 400 has finished scanning in the first scanning direction (the direction of arrow 710).

When the in-line sensor 400 detects the trigger mark 761, it detects to start scanning in the second scanning direction (the direction of the arrow 711). More specifically, when inline sensor 400 detects trigger mark 730, inline sensor 400 waits for detection of an adjustment image. When the in-line sensor 400 detects the second color patch 750 arranged at the first position, the in-line sensor 400 measures the color of the second color patch 750 and outputs the measured value to the CPU 310 . After that, the in-line sensor 400 detects the second placed trigger mark 730 and also measures the color of the second color patch 750 . In-line sensor 400 measures the color of second color patches 750 arranged at eight locations while moving in the direction of arrow 711 and outputs the measured values to CPU 310 .

After that, when in-line sensor 400 detects trigger mark 770 , in-line sensor 400 outputs a signal corresponding to the detection result to CPU 310 . CPU 310 detects that the measurement of second color patch 750 along the second scanning direction (the direction of arrow 720) has ended. CPU 310 determines whether or not the color of the image formed on long paper 700 is the specified color based on the measured value and color information based on preset information. CPU 310 may adjust the color according to the result of its determination.

When the in-line sensor 400 detects the trigger mark 772 following the trigger mark 771, it detects that the scanning of the long paper 700 for image adjustment is completed.

In another aspect, the trigger mark 772 may not be formed on the long paper 700 and the third color patch may be formed in the same manner as the first color patch 740 . In this case, assuming that the third color patch is arranged in the same manner as the first color patch 740, the in-line sensor 400 again moves in the direction of arrow 710 to measure the third color patch. can.

Referring to FIG. 8, color adjustment using in-line sensor 400 can also be applied to sheets. Specifically, each sheet is sequentially transported in the direction of arrow 720, similar to the case illustrated in FIG. In-line sensor 400 moves in the direction of arrows 710,711.

Trigger marks 730 and first color patches 740 are formed at eight locations on the first sheet 810 . Furthermore, trigger marks 760 and 761 are arranged. Trigger marks 730 and second color patches 750 are formed at eight locations on the second sheet 820 . Further, trigger marks 770, 771, 772 are arranged.

While the first sheet 810 is conveyed in the direction of arrow 720, the in-line sensor 400 moves in the direction of arrow 710 at a predetermined speed. This speed is set, for example, so that the in-line sensor 400 can measure eight first color patches 740 while the sheet 810 reaches from the left edge to the right edge. When the in-line sensor 400 detects the first trigger mark 730, it assumes that the first color patch 740 will appear after that, and waits in the measurement mode.

The in-line sensor 400 measures the color of the first color patch 740 at the first location and outputs the measured value. The measured value is input to CPU 310 . The in-line sensor 400 continues to move according to the conveying speed of the sheet 810, and when the second trigger mark 730 is detected, it waits for the measurement of the first color patch 740 at the second position. The in-line sensor 400 outputs a measured value when it detects the second first color patch 740 . In-line sensor 400 thus measures the color of eight first color patches while moving in the direction of arrow 710 .

When in-line sensor 400 detects trigger mark 760 , it outputs a signal indicating the detection to CPU 310 . CPU 310 detects that scanning in the first scanning direction (the direction of arrow 710) has ended.

When the in-line sensor 400 detects the trigger mark 761, it detects that the scanning of the second sheet 820 in the second scanning direction (the direction of the arrow 711) is started. More specifically, when inline sensor 400 detects trigger mark 730, inline sensor 400 waits for detection of an adjustment image. When the in-line sensor 400 detects the second color patch 750 arranged at the first position, the in-line sensor 400 measures the color of the second color patch 750 and outputs the measured value to the CPU 310 . After that, the in-line sensor 400 detects the second placed trigger mark 730 and also measures the color of the second color patch 750 . In-line sensor 400 measures the color of second color patches 750 arranged at eight locations while moving in the direction of arrow 711 and outputs the measured values to CPU 310 .

After that, when in-line sensor 400 detects trigger mark 770 , in-line sensor 400 outputs a signal corresponding to the detection result to CPU 310 . CPU 310 detects that the measurement of second color patch 750 along the second scanning direction (the direction of arrow 720) has ended. CPU 310 determines whether the color of the image formed on sheet 820 is the specified color based on the measured value and color information based on preset information. CPU 310 may adjust the color according to the result of its determination.

When the in-line sensor 400 detects the trigger mark 772 following the trigger mark 771, it detects that the image adjustment has been completed for all colors.

[Other examples of images for adjustment]
Another example of the adjustment image will be described with reference to FIG. FIG. 9 is a diagram representing one manner in which patches are placed on a strip of paper 900 when in-line sensor 500 is used.

Referring to FIG. 9, long paper 900 is conveyed in the direction of arrow 720 . In-line sensor 500 moves in the direction of arrows 710,711. That is, the in-line sensor 500 reciprocates in a direction perpendicular to the direction in which the long paper 900 is conveyed.

In one aspect, image forming section 120 forms a plurality of trigger marks 730 , a plurality of first color patches 740 , and a plurality of second color patches 750 on long paper 700 . In the example shown in FIG. 9, the trigger marks 730 and the first color patches 740 are formed at eight locations across the long sheet of paper 900 . In this case, the trigger marks 730 are arranged in a line along the transport direction of the long paper 900 . The intervals at which the trigger marks 730 are arranged are, for example, equal intervals.

When the in-line sensor 500 detects the first trigger mark 730, it outputs a detection result. A detection result is transmitted to the CPU 310 . CPU 310 sets the operation mode of image forming apparatuses 100 and 200 to the color adjustment mode, and waits for subsequent signal reception.

Upon detecting the first color patch 740 at the first location, the in-line sensor 500 measures the color of the first color patch 740 and outputs the measured value. The measured value is input to CPU 310 .

While the long paper 900 is being conveyed in the direction of arrow 720, the in-line sensor 500 moves in the direction of arrow 710 at a predetermined speed. This speed is set, for example, so that the in-line sensor 500 can measure the first color patches 740 formed at eight locations while the in-line sensor 500 reaches from the left end to the right end of the long paper 900 .

In-line sensor 500 measures the color of first color patch 740 at the first location. The measured value is input to CPU 310 . The in-line sensor 500 continues to move according to the conveying speed of the long paper 900, and when the trigger mark 730 at the second position is detected, the measurement of the first color patch 740 at the second position is awaited. The in-line sensor 500 outputs a measured value when the second first color patch 740 is detected. Inline sensor 500 measures the color of eight first color patches while moving in the direction of arrow 710 .

When the trigger sensor 420 does not detect the next trigger mark 730 within a set period after detecting the trigger mark 730 , it outputs a signal to that effect to the CPU 310 . CPU 310 detects that in-line sensor 500 has finished scanning in the first scanning direction (the direction of arrow 710).

After detecting that scanning in the first scanning direction (direction of arrow 710) has ended, in-line sensor 500 waits for scanning in the second scanning direction (direction of arrow 711).

When the trigger sensor 420 detects the first trigger mark 730 (the ninth from the top in FIG. 9) for scanning in the second scanning direction (the direction of the arrow 711), it outputs a detection result. A detection result is transmitted to the CPU 310 . CPU 310 sends a signal to start scanning in the second scanning direction (direction of arrow 711) to in-line sensor 500 . More specifically, when the in-line sensor 500 detects the second color patch 750 arranged at the first position, it measures the color of the second color patch 750 and outputs the measured value. The measured value is input to CPU 310 .

After that, the in-line sensor 500 detects the second placed trigger mark 730 and also measures the color of the second color patch 750 . The in-line sensor 500 sequentially measures the colors of the second color patches 750 arranged at eight locations while moving in the direction of the arrow 711 and outputs each measured value. Each measured value is input to the CPU 310 .

Thereafter, when the trigger sensor 420 does not detect the next trigger mark 730 within a set period after detecting the trigger mark 730 , it outputs a signal to that effect to the CPU 310 . CPU 310 detects that the measurement of second color patch 750 along the second scanning direction (the direction of arrow 720) has ended. The CPU 310 determines whether or not the color of the image formed on the long paper 900 is the specified color based on the measurement values obtained so far and the color information based on preset information. . CPU 310 may adjust the color according to the result of its determination.

When the CPU 310 detects the end of the measurement of the second color patch 750 in the second scanning direction (the direction of the arrow 720) and the trigger sensor 420 does not detect the next trigger mark 730 within the set period, A signal to that effect is output to CPU 310 . The CPU 310 detects that the image adjustment of the long paper 900 has been completed.

In another aspect, after CPU 310 detects the end of measurement of second color patch 750 in the second scanning direction (the direction of arrow 720), trigger sensor 420 detects the next trigger mark 730 within a set period. is detected, the third color patch may be formed similarly to the first color patch 740 . In this case, assuming that the third color patch is arranged in the same manner as the first color patch 740, the in-line sensor 500 again moves in the direction of arrow 710 to measure the third color patch. can.

Still another example will be described with reference to FIG. FIG. 10 is a diagram showing another aspect of how patches are arranged on long paper 1000 when inline sensor 400 is used. The embodiment shown in FIG. 10 is an example in which the inline scanner 140 is used as one of the trigger sensors and the trigger marks 730 arranged at both ends of the long paper 1000 are detected by the inline scanner 140, which is shown in FIG. different from the example given. Note that the trigger mark 730 is a mark that is also used for sheet position adjustment.

Long paper 1000 is conveyed in the direction of arrow 720 . In-line sensor 400 moves in the direction of arrows 710,711. 7, the in-line sensor 400 reciprocates in the direction perpendicular to the direction in which the long paper 1000 is conveyed.

In one aspect, image forming section 120 forms two trigger marks 730 , a plurality of first color patches 740 and a plurality of second color patches 750 on long paper 1000 . In the example shown in FIG. 10, two trigger marks 730 are formed on both ends of the long paper. The first color patches 740 are formed at eight locations across the long paper 1000 .

While the long paper 1000 is being conveyed in the direction of arrow 720, in-line sensor 400 moves in the direction of arrow 710 at a predetermined speed. This speed is set, for example, so that the in-line sensor 400 can measure the first color patches 740 formed at eight locations while the in-line sensor 400 reaches from the left edge to the right edge of the long paper 1000 . When the in-line scanner 140 detects the first trigger mark 730, it outputs the detection result. A detection result is input to the CPU 310 . CPU 310 then assumes that a color patch will appear, notifies in-line sensor 400, and waits in measurement mode.

The in-line sensor 400 measures the color of the first color patch 740 at the first location and outputs the measured value. The measured value is input to CPU 310 . The in-line sensor 400 continues to move according to the transport speed of the long paper 700 . The in-line sensor 400 outputs a measured value when it detects the second first color patch 740 . The measured value is input to CPU 310 . In-line sensor 400 thus measures the color of eight first color patches while moving in the direction of arrow 710 .

When in-line sensor 400 detects trigger mark 760, it outputs a signal indicating the detection. The signal is input to CPU 310 . Based on the signal, CPU 310 detects that in-line sensor 400 has finished scanning in the first scanning direction (the direction of arrow 710). Movement of in-line sensor 400 ends upon detection of trigger mark 760 . Conveyance of the long paper 1000 continues. The in-line sensor 400 outputs a detection result when the trigger mark 761 is detected. A detection result is input to the CPU 310 . CPU 310 detects the start of scanning in the direction of arrow 711 based on the detection result.

More specifically, when the in-line sensor 400 detects the second color patch 750 arranged at the first position, it measures the color of the second color patch 750 and outputs the measured value. The measured value is input to CPU 310 . After that, when the in-line sensor 400 detects the second color patch 750 placed at the second position, the in-line sensor 400 measures the color of the second color patch 750 . In-line sensor 400 sequentially measures the colors of second color patches 750 arranged at eight locations while moving in the direction of arrow 711 and outputs each measured value to CPU 310 .

After that, when the in-line sensor 400 detects the trigger mark 770, it outputs a signal according to the detection result. The signal is input to CPU 310 . CPU 310 detects that the measurement of second color patch 750 along the second scanning direction (the direction of arrow 720) is completed based on the reception of this signal. CPU 310 determines whether or not the color of the image formed on long paper 1000 is the specified color based on the measured value and color information based on preset information. CPU 310 may adjust the color according to the result of its determination.

When the in-line sensor 400 detects the trigger mark 772 following the trigger mark 771, it detects that the scanning of the long paper 1000 for image adjustment is completed.

In another aspect, the trigger mark 772 may not be formed on the long paper 700 and the third color patch may be formed in the same manner as the first color patch 740 . In this case, assuming that the third color patch is arranged in the same manner as the first color patch 740, the in-line sensor 400 again moves in the direction of arrow 710 to measure the third color patch. can.

The technical features disclosed above can be summarized as follows.

[Configuration 1] Image forming apparatuses 100 and 200 according to an embodiment include a transport mechanism (transport unit 170) that transports a print medium, an image forming unit 120 that forms an image on the print medium, and an image forming unit 120 that forms an image on the print medium. In-line sensor 150 is movable in a direction perpendicular to the transport direction of the print medium to scan one or more color patches, and depending on the transport speed of the print medium and the speed of movement of the in-line sensor, one or more color and a control unit (CPU 310) that controls the image forming unit to form patches on a print medium.

[Arrangement 2] In one aspect, the color patches are arranged according to the information of the printing medium (for example, the width of the long sheet, the length of one sheet of printing, the size of the sheet, etc.). CPU 310 determines the location of the color patch based on the information. The information is given as data for image formation before printing is started.

[Configuration 3] In one aspect, the information includes the type and size of paper.

[Configuration 4] In one aspect, the in-line sensor includes a spectrophotometer.

[Configuration 5] In one aspect, the in-line sensor further includes a trigger sensor. Since the spectrophotometer and the trigger sensor can move together, the CPU 310 can form the color patch and the trigger patch in close proximity.

[Configuration 6] In one aspect, the image forming apparatus further includes a trigger sensor provided separately from the in-line sensor. Since the trigger sensor is provided independently of the movement of the in-line sensor, the trigger mark 730 can be formed at locations remote from the color patch locations.

[Structure 7] In a certain aspect, the difference between the transport speed of the transport mechanism when forming one or more color patches on a print medium and the transport speed when forming an image other than one or more color patches on a print medium is , within a predetermined range. The predetermined range is a range in which there is substantially no speed difference. This eliminates the need to change the speed at which the print medium is conveyed to print the content image on the print medium and the speed at which the print medium is conveyed to print the color patches for color adjustment on the print medium. , the need to complicate the transport control of the image forming apparatuses 100 and 200 is eliminated.

[Arrangement 8] In one aspect, the image forming section further forms a trigger mark at a predetermined position with respect to the positions of the one or more color patches.

[Arrangement 9] In one aspect, the arrangement of the trigger marks is determined according to the transport speed of the print medium and the movement speed of the inline sensor 150 .

[Configuration 10] In one aspect, the controller performs color adjustment based on signals output from an in-line sensor by scanning one or more color patches. For example, if the color values obtained by reading the image (color patch) actually formed on the print medium are different from the color values given as the image formation instruction, the CPU 310 Corrects the numerical value that specifies the color based on the difference between

[Arrangement 11] According to another embodiment, there is provided a control method for an image forming apparatus. This control method is implemented, for example, by CPU 310 of image forming apparatuses 100 and 200 . Specifically, the control method comprises the steps of transporting a print medium; forming an image on the print medium; and scanning one or more color patches formed on the print medium. and moving the in-line sensor in a vertical direction. Forming the image includes forming one or more color patches on the print medium in response to the transport speed of the print medium and the speed of movement of the in-line sensor.

[Arrangement 12] According to still another embodiment, there is provided a program for controlling an image forming apparatus. The program instructs an image forming apparatus to perform the steps of transporting a print medium, forming an image on the print medium, and scanning one or more color patches formed on the print medium. and moving the in-line sensor in the desired direction. Forming the image includes forming one or more color patches on the print medium in response to the transport speed of the print medium and the speed of movement of the in-line sensor. For example, CPU 310 can read the program stored in storage unit 330 to RAM 320 and execute the instructions included in the program to execute each of the processing steps described above.

As described above, in the image forming apparatuses 100 and 200 according to the present embodiment, the in-line sensors 400 and 500, which are the colorimetric units, move in the direction perpendicular to the paper conveying direction, and the colors formed on the paper are measured. Measure the patch. As a result, the in-line sensors 400 and 500 can measure the patches arranged in the main scanning direction without temporarily stopping or slowing down the paper conveyance.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning of equivalents of the scope of the claims.

The disclosed technical features are applicable to commercial printers, such as both sheet-fed printers and long paper (roll paper) printers.

Reference Signs List 100,200 image forming apparatus 110 paper feeding unit 120 image forming unit 130,140 inline scanner 150,400,500 inline sensor 160 paper discharge unit 170 transport unit 190 control unit 210 paper feed roller 220 Paper discharge roller 320 RAM 330 storage unit 340 operation unit 350 display unit 360 communication unit 370 image reading unit 410 colorimeter 420 trigger sensor 700,900,1000 long paper 710,711, 720 arrow, 722, 730, 760, 761, 770, 771, 772 trigger mark, 740 first color patch, 750 second color patch, 810, 820 sheet.

Claims (12)

a transport mechanism for transporting the print medium;
an image forming unit that forms an image on the print medium;
an in-line sensor movable in a direction perpendicular to the transport direction of the print medium to scan one or more color patches formed on the print medium;
an image forming apparatus, comprising: a controller that controls the image forming unit to form the one or more color patches on the print medium according to the transport speed of the print medium and the moving speed of the inline sensor. . 2. The image forming apparatus according to claim 1, wherein said color patches are arranged according to information on said print medium. 3. The image forming apparatus according to claim 2, wherein said information includes paper type and size. 4. The image forming apparatus according to claim 1, wherein said in-line sensor includes a spectrophotometer. 5. The image forming apparatus of claim 4, wherein the in-line sensor further includes a trigger sensor. 5. The image forming apparatus according to claim 4, further comprising a trigger sensor provided separately from said in-line sensor. The difference between the transport speed of the transport mechanism when forming the one or more color patches on the print medium and the transport speed when forming an image other than the one or more color patches on the print medium is determined in advance. The image forming apparatus according to any one of claims 1 to 6, which is within a defined range. 8. The image forming apparatus according to claim 1, wherein said image forming section further forms a trigger mark at a predetermined position with respect to the position of said one or more color patches. 9. The image forming apparatus according to claim 8, wherein the placement of said trigger mark is determined according to the transport speed of said print medium and the moving speed of said in-line sensor. 10. The image forming apparatus according to claim 1, wherein said control section performs color adjustment based on a signal output from said in-line sensor by scanning said one or more color patches. conveying a print medium;
forming an image on the print medium;
moving an in-line sensor in a direction perpendicular to the direction of travel of the print medium to scan one or more color patches formed on the print medium;
A method of controlling an image forming apparatus, wherein the step of forming an image includes forming the one or more color patches on the print medium according to a transport speed of the print medium and a moving speed of the inline sensor. . A program for controlling an image forming apparatus, the program causing the image forming apparatus to:
conveying a print medium;
forming an image on the print medium;
moving an in-line sensor in a direction perpendicular to the direction of travel of the print medium to scan one or more color patches formed on the print medium;
The step of forming the image includes the step of forming the one or more color patches on the print medium according to the transport speed of the print medium and the moving speed of the in-line sensor, controlling an image forming apparatus. program for.

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