JP2017035837A - Image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To disperse positions for forming marks corresponding to the use count to a calibration sheet used in calibration of an image reading unit.SOLUTION: When a sheet to be fed next is a calibration sheet (step S1; YES), the coordinates of the position for forming a mark is decided by using the random number (step S2), the mark is formed at the decided position on the calibration sheet by an image formation unit (step S3), and the calibration sheet formed with the mark is read by an image reading unit (step S4). On the basis of the number of read marks, the use count of the calibration sheet is acquired (step S5), and the residual use count (residual number) of the calibration sheet is calculated (step S6). When the residual number of the calibration sheet is 0 or more (step S7; YES), the residual number of the calibration sheet is displayed on a display unit (step S8).SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus.

Conventionally, in an image forming apparatus such as a copying machine or a printer, an image on a sheet after image formation is read in order to adjust the color or position of the image or to check whether the image is appropriate. A color sensor (image reading unit) is used. As a method for calibrating the color sensor, a method of reading a calibration image by inserting a sheet (calibration sheet) on which a calibration image is printed into a post-processing apparatus on which the color sensor is mounted is common.
However, in a post-processing apparatus that does not have a paper feed tray, it is necessary to manually set a calibration sheet inside the post-processing apparatus, and it takes time to calibrate the color sensor. Therefore, it is conceivable to calibrate the color sensor by passing a calibration sheet from the main body sheet feeding tray of the image forming apparatus in the same manner as in normal image formation.

Moreover, since the calibration paper is expensive, it is assumed that it is reused. When the calibration paper is transported from the main unit feed tray under the same conditions as normal image formation, the calibration paper is damaged by heat and transport during fixing, and the image density fluctuates. Can no longer play the role. For this reason, the calibration paper is set with a life (usable number of times), and this life needs to be managed.
However, if the operator who calibrates the color sensor manually counts the number of times that the calibration sheet is used, the calibration sheet may not be correctly calibrated if the counting sheet is erroneously used and the calibration sheet whose life has been exceeded is used. In addition, when a plurality of different workers use one calibration sheet, there is a possibility that accurate counting cannot be performed.

  By the way, although different from the proof paper, a technique for managing the number of times the reusable paper is used by giving an image formation number mark to the reusable paper that can be reused by deinking processing has been proposed (see Patent Document 1). ). In Japanese Patent Laid-Open No. 2004-260260, an image formation number mark is read by a paper information sensor provided upstream from an image forming unit, and the mark is added according to the position of the read mark. Yes.

JP 2001-228757 A

However, when the technique described in Patent Document 1 is used for a calibration sheet, if a mark is read by a color sensor to be calibrated and then a new mark is written on the calibration sheet, the image forming unit included in the image forming apparatus It is necessary to provide a separate writing member (such as a stamp) downstream of the color sensor, which increases costs.
In order to avoid an increase in cost, an image forming unit originally provided in the image forming apparatus is used as a means for writing the mark. In this case, the position of the mark already formed on the calibration sheet can be grasped. The mark is written on the proof sheet in the absence. Therefore, there is a problem that it is difficult to determine where the mark should be formed on the calibration sheet.

  The present invention has been made in view of the above-described problems in the prior art, and it is an object to disperse the positions when marks corresponding to the number of times of use are formed on a calibration sheet used for calibration of an image reading unit. And

  In order to solve the above-described problem, the invention according to claim 1 is provided on an image forming unit that forms an image on a sheet, and downstream of the image forming unit, and is formed on the sheet by the image forming unit. An image reading unit that reads an image; a paper feeding unit that supplies paper to the image forming unit; and a paper that is set in the paper feeding unit is a calibration paper used for calibration of the image reading unit. The position of the mark corresponding to the number of times of use is determined using a random number in the margin area, and the image forming unit forms the mark at the determined position of the calibration sheet, and the image reading unit forms the mark. And an image forming apparatus comprising: a control unit that reads the mark.

  The invention according to claim 2 is an image forming unit that forms an image on a sheet, an image reading unit that is provided downstream of the image forming unit and that reads an image formed on the sheet by the image forming unit, An image forming apparatus configured to supply a sheet to the image forming unit; and an image forming apparatus in a margin area of the calibration sheet when the sheet set in the sheet feeding unit is a calibration sheet used for calibration of the image reading unit. The mark position corresponding to the number of times of use is determined based on the unique information, and the image forming unit is caused to form the mark at the determined position of the calibration sheet, and the image reading unit is configured to store the formed mark. An image forming apparatus comprising: a control unit that causes reading.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the control unit obtains the number of times the calibration sheet is used based on the number of marks read by the image reading unit. It is characterized by doing.

  According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, when the density of the mark read by the image reading unit is equal to or higher than a predetermined value, the control unit displays the mark. It is characterized by judging that it has overlapped.

  According to a fifth aspect of the present invention, in the image forming apparatus according to the fourth aspect, when the control unit determines that the marks are overlapped, the calibration sheet is adjusted according to the overlapping state of the marks. The addition value in the number of times of use is changed.

  According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the third to fifth aspects, the control unit determines the remaining number of times the calibration sheet is used from the acquired number of times the calibration sheet is used. And the user is notified of the calculated remaining number of uses.

  According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the third to sixth aspects, the control unit exceeds a predetermined upper limit value for the number of times the acquired calibration sheet is used. In such a case, the user is notified of the fact.

  According to an eighth aspect of the present invention, in the image forming apparatus according to any one of the first to seventh aspects, each time the control unit causes the image forming unit to form the mark, The shape condition is switched.

  According to a ninth aspect of the present invention, in the image forming apparatus according to the second aspect, the control unit determines the position of the current mark based on the unique information of the image forming apparatus and the position of the previous mark. It is characterized by that.

  According to a tenth aspect of the present invention, in the image forming apparatus according to the ninth aspect, the control unit shifts the position of the current mark from the position of the previous mark.

  According to the present invention, it is possible to disperse the positions when marks corresponding to the number of times of use are formed on a calibration sheet used for calibration of the image reading unit.

1 is a schematic configuration diagram of an image forming apparatus according to the present invention. 2 is a block diagram illustrating a functional configuration of the image forming apparatus. FIG. 3 is a flowchart illustrating a calibration process executed in the image forming apparatus according to the first embodiment. It is a figure which shows the example of a tray setting screen. It is a flowchart which shows the mark position determination process A. It is a figure which shows the example of the calibration paper in which the mark was formed. 10 is a flowchart illustrating a usage count process executed in the image forming apparatus according to the second embodiment. It is a figure which shows the example of the calibration paper in which a part of mark overlaps. 10 is a flowchart illustrating mark formation condition determination processing executed in the image forming apparatus according to the third embodiment. FIG. 10 is a diagram illustrating an example of a calibration sheet in which the position of the current mark is determined based on the manufacturing number of the image forming apparatus. 14 is a flowchart illustrating a mark position determination process B executed in the image forming apparatus according to the fourth embodiment. 10 is a flowchart illustrating a mark position determination process C executed in the image forming apparatus according to the fifth embodiment. 6 is a diagram illustrating an example of a calibration sheet in which the position of the current mark is determined based on the serial number of the image forming apparatus and the position of the previous mark. FIG.

[First Embodiment]
First, a first embodiment of an image forming apparatus according to the present invention will be described. The present invention is not limited to the illustrated example.

FIG. 1 is a schematic configuration diagram of the image forming apparatus 100.
The image forming apparatus 100 is an image forming apparatus that forms a color image by an electrophotographic method based on image data obtained by reading an image from a document or image data received from an external device.
The image forming apparatus 100 includes an operation unit 15, a display unit 20, a document reading unit 30, an image forming unit 40, a paper feeding unit 50, a post-processing unit 60, an image reading unit 70, and the like.

  The operation unit 15 includes a touch panel formed so as to cover the display screen of the display unit 20 and various operation buttons such as numeric buttons and a start button, and an operation signal based on a user operation is transmitted to the control unit 81 (see FIG. 2). ).

  The display unit 20 is configured by an LCD (Liquid Crystal Display), and displays various screens according to instructions of display signals input from the control unit 81.

  The document reading unit 30 includes an ADF (automatic document feeder), a scanner, and the like, and outputs image data obtained by reading an image of the document to the control unit 81.

The image forming unit 40 forms an image on the paper supplied from the paper supply unit 50.
The image forming unit 40 includes photosensitive drums 41Y, 41M, 41C, and 41K corresponding to colors of yellow (Y), magenta (M), cyan (C), and black (K), an intermediate transfer belt 42, and a secondary transfer roller. 43, a fixing unit 44, a reversing mechanism 45, and the like.

After the photoreceptor drum 41Y is uniformly charged, it is scanned and exposed with a laser beam based on yellow image data to form an electrostatic latent image. Then, yellow toner is attached to the electrostatic latent image on the photosensitive drum 41Y, and development is performed.
Since the photosensitive drums 41M, 41C, and 41K are the same as the photosensitive drum 41Y except that the handled colors are different, the description thereof is omitted.

The toner images of the respective colors formed on the photosensitive drums 41Y, 41M, 41C, and 41K are sequentially transferred onto the rotating intermediate transfer belt 42 (primary transfer). That is, on the intermediate transfer belt 42, a color toner image is formed by superimposing four color toner images.
The color toner images on the intermediate transfer belt 42 are collectively transferred onto the paper by the secondary transfer roller 43 (secondary transfer).

The fixing unit 44 includes a heating roller that heats the sheet on which the color toner image is transferred and a pressure roller that pressurizes the sheet, and fixes the color toner image on the sheet by heating and pressing.
The reversing mechanism 45 reverses the paper surface when images are formed on both surfaces of the paper.

  The paper feed unit 50 includes paper feed trays T <b> 1 to T <b> 3 and supplies paper to the image forming unit 40. In each of the paper feed trays T1 to T3, paper of a paper type and size predetermined for each paper feed tray is stored.

  The post-processing unit 60 discharges the paper on which the image has been formed by the image forming unit 40 to the paper discharge trays T <b> 11 and T <b> 12, or accumulates it in the large capacity stacker 61. Other post-processing devices that perform post-processing such as sorting, stapling, punching, folding, and bookbinding may be connected as necessary.

The image reading unit 70 is provided downstream of the image forming unit 40, reads an image on a sheet, and outputs read data (image data) to the control unit 81. The image reading unit 70 is a color sensor that receives light emitted from a light source and reflected from the surface of a sheet by a light receiving element and outputs a signal corresponding to the intensity of the light. The image reading unit 70 may be configured by a line sensor in which a plurality of light receiving elements are arranged at predetermined intervals in a direction orthogonal to the paper conveyance direction, or only in a predetermined region in the direction orthogonal to the paper conveyance direction. May be read.
For example, the image reading unit 70 is used when reading an image formed on a sheet by the image forming unit 40 and inspecting the color, position, dirt, and the like of the image.
The image reading unit 70 is used to read a calibration image from a sheet (calibration sheet) on which a predetermined calibration image is printed and calibrate the output value of the image reading unit 70. The calibration image includes patches and gradation patterns for each color.

FIG. 2 is a block diagram illustrating a functional configuration of the image forming apparatus 100.
As shown in FIG. 2, the image forming apparatus 100 includes an operation unit 15, a display unit 20, a document reading unit 30, an image forming unit 40, a paper feeding unit 50, a post-processing unit 60, an image reading unit 70, a control unit 81, A storage unit 82, a communication unit 83, a transport unit 84, and the like are provided. Note that description of the functional units already described is omitted.

  The control unit 81 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The CPU reads various processing programs stored in the ROM in accordance with an operation signal input from the operation unit 15 or an instruction signal received by the communication unit 83, expands the program in the RAM, and displays an image according to the expanded program. The operation of each part of the forming apparatus 100 is centrally controlled.

  The storage unit 82 is configured by a nonvolatile storage device such as a hard disk or a flash memory, and stores various data. For example, the storage unit 82 stores an upper limit predetermined as the number of times the calibration sheet can be used (lifetime). The upper limit value may be acquired from information input from the operation unit 15 by the user.

  The communication unit 83 transmits / receives data to / from an external device connected to a communication network such as a LAN (Local Area Network).

  The transport unit 84 includes transport rollers for transporting paper, supplies the paper stored in the paper feed trays T1 to T3 of the paper feed unit 50 to the image forming unit 40, and discharges the paper after image formation to the paper discharge tray. The sheet is conveyed in the image forming apparatus 100 until it is conveyed to T11, T12 or the large-capacity stacker 61.

  When the sheet set in the sheet feeding unit 50 is a calibration sheet used for calibration of the image reading unit 70, the control unit 81 uses a random number in the blank area of the calibration sheet to set the mark position corresponding to the number of uses. Then, the image forming unit 40 is caused to form a mark at the determined position of the calibration sheet, and the image reading unit 70 is made to read the formed mark. The margin area is an area excluding the area where the calibration image is printed on the calibration sheet.

The control unit 81 acquires the number of times the calibration sheet is used based on the number of marks read by the image reading unit 70.
The control unit 81 calculates the remaining number of times of use of the calibration sheet from the acquired number of times of use of the calibration sheet, and notifies the user of the calculated remaining number of times of use.
When the number of times the acquired calibration sheet is used exceeds a predetermined upper limit value, the control unit 81 notifies the user via the display unit 20 to that effect.

Next, the operation of the image forming apparatus 100 according to the first embodiment will be described.
FIG. 3 is a flowchart showing the calibration process executed in the image forming apparatus 100. This processing is realized by software processing through cooperation between the CPU of the control unit 81 and a program stored in the ROM.

  First, the control unit 81 determines whether or not the next sheet fed from the sheet feeding unit 50 is a calibration sheet (step S1). Specifically, the control unit 81 refers to the tray setting information stored in the storage unit 82 when the start button of the operation unit 15 is pressed, and determines the paper type for the designated paper feed tray. When “calibration paper” is set as “,” it is determined that the next paper to be fed is the calibration paper.

  FIG. 4 shows an example of the tray setting screen 21 displayed on the display unit 20. The tray setting screen 21 is a screen for changing paper attributes for a paper feed tray designated as a setting target. In FIG. 4, the paper type button 22 for changing the paper type is selected for the “paper feed tray T1”, and the plain paper button 23, the high-quality paper button 24, the color paper button 25, the paint type are selected as the paper type candidates. A work paper button 26 and a calibration paper button 27 are displayed. When the user selects the calibration paper button 27 and presses the OK button 28, the control unit 81 associates “paper feed tray T 1” with information indicating that the paper type is calibration paper, and sets the tray. It is stored in the storage unit 82 as setting information.

  If the next paper to be fed is calibration paper (step S1; YES), the control unit 81 performs a mark position determination process A (step S2). The mark position determination process A is a process for determining a position as a mark formation condition corresponding to the number of times the calibration sheet is used.

Here, the mark position determination processing A will be described with reference to FIG.
First, the control unit 81 acquires a first random number used for determining a position in the main scanning direction (step S21). For example, the control unit 81 acquires a random number generated by a random number generator or a random number generation program.
Next, the control unit 81 acquires a second random number used for determining the position in the sub-scanning direction (step S22).

  Next, the control unit 81 determines the coordinates of the position where the mark is formed using the first random number and the second random number (step S23). For example, when the first random number is 140 and the second random number is 40, the mark writing start position is set to the end in the main scanning direction (paper end or image formable area end. The same shall apply.) To 140 mm, and 40 mm from the end in the sub-scanning direction.

Next, the control unit 81 determines whether or not the mark formation position coordinates determined in step S23 are within the blank area (step S24). If the mark formation position coordinates are not within the blank area (step S24; NO), the process returns to step S21 and the process is repeated.
In step S24, when the mark formation position coordinates are within the blank area (step S24; YES), the mark position determination process A ends.

  Returning to FIG. 3, the control unit 81 controls the image forming unit 40 to form a mark at the position determined in the mark position determination process A of the calibration sheet (step S3).

  Next, the control unit 81 controls the image reading unit 70 to read the calibration sheet on which the mark is formed (step S4). The image reading unit 70 reads an area on which a calibration image on a calibration sheet is printed and a blank area.

  Next, the control unit 81 acquires the number of times the calibration sheet is used based on the number of marks read by the image reading unit 70 (use number counting process) (step S5). Specifically, the control unit 81 counts the number of marks from the calibration sheet reading data obtained by the image reading unit 70, and sets the number of marks as the number of times the calibration sheet is used.

FIG. 6 shows an example of a calibration sheet 200 on which marks are formed. The margin areas 201 and 202 of the calibration sheet 200 include marks M1 to M3 that have already been formed and a mark M4 that has been formed this time. The writing start position of the mark M4 is, for example, 5 mm from the end in the main scanning direction and 240 mm from the end in the sub-scanning direction. The width of the mark in the main scanning direction and the width in the sub-scanning direction are the minimum necessary for reading by the sensor of the image reading unit 70. For example, the width in the main scanning direction is 15 mm, and the width in the sub scanning direction is 20 mm. In FIG. 6, the width in the main scanning direction and the width in the sub scanning direction of each of the marks M1 to M4 are constant, but may be variable depending on the mark forming conditions such as the determined mark position. In FIG. 6, the illustration of the calibration image is omitted.
Since the sensor value output by the image reading unit 70 is different between the mark region and the region other than the mark, the control unit 81 follows the sub-scanning direction based on the image data obtained in the margin regions 201 and 202. The number of boundaries (edges) between the mark area and the area other than the mark is counted, and a value obtained by dividing the counted number of edges by 2 is defined as the number of marks. In FIG. 6, the number of edges “8” along the sub-scanning direction is acquired in the blank areas 201 and 202, and a value “4” obtained by dividing the number of edges by 2 is set as the number of marks.

  Next, the control unit 81 reads an upper limit value previously determined as the number of times the calibration sheet can be used (lifetime) from the storage unit 82, subtracts the number of times the calibration sheet is used from the upper limit value, and uses the remaining calibration sheet. The number of times (hereinafter referred to as the remaining number of times) is calculated (step S6).

Next, the control unit 81 determines whether or not the remaining number of calibration sheets is 0 or more (step S7).
When the remaining number of calibration sheets is 0 or more (step S7; YES), the control unit 81 displays the remaining number of calibration sheets on the display unit 20 (step S8).

  In step S7, when the remaining number of calibration sheets is less than 0 (step S7; NO), the control unit 81 displays on the display unit 20 that the number of use of the calibration sheet has exceeded the upper limit (step S7). S9).

Next, the control unit 81 accepts selection of whether or not to validate the calibration based on the reading result of the calibration sheet read in step S4 (step S10). Specifically, the control unit 81 causes the display unit 20 to display a selection screen for selecting whether or not to validate the calibration based on the result of reading the calibration sheet, and gives an operation instruction from the operation unit 15 by the user. Accept.
If the number of times the calibration sheet is used exceeds the upper limit value, the calibration sheet may deteriorate and the image reading unit 70 may not be correctly calibrated. For this reason, although the accuracy of calibration cannot be guaranteed, calibration is validated according to the user's wishes.

  After step S8 or in step S10, when the calibration based on the reading result of the calibration sheet is validated (step S10; YES), the control unit 81 is based on the reading result of the calibration image area on the calibration sheet. The image reading unit 70 is calibrated (step S11).

  After step S11, if the next paper to be fed is not a calibration paper in step S1 (step S1; NO), or if calibration based on the result of reading the calibration paper is not valid in step S10 ( Step S10; NO), the calibration process is terminated.

  As described above, according to the first embodiment, since the position of the mark formed on the calibration sheet is determined using a random number, it is possible to prevent the mark positions from overlapping, and the image reading unit 70. The positions at the time of forming marks corresponding to the number of times of use can be dispersed on the calibration paper used for calibration.

Moreover, since the number of times the calibration sheet is used is acquired based on the number of marks, the number of times the calibration sheet is used can be easily grasped.
Also, by displaying the remaining number of calibration sheets, the user can recognize the remaining number. The user can prepare an alternative proof sheet when the remaining number of times decreases.
Further, when the number of use of the calibration paper exceeds the upper limit value, this is displayed, so that the user can be warned that the calibration paper has reached the end of its life.

[Second Embodiment]
Next, a second embodiment to which the present invention is applied will be described.
Since the image forming apparatus according to the second embodiment has the same configuration as that of the image forming apparatus 100 according to the first embodiment, FIG. 1 and FIG. 2 are used, and the configuration is illustrated and described. Omitted. Hereinafter, a configuration and processing characteristic of the second embodiment will be described.

The control unit 81 acquires the number of times the calibration sheet is used based on the number of marks read by the image reading unit 70.
The control unit 81 determines that the marks overlap when the density of the marks read by the image reading unit 70 is equal to or higher than a predetermined value.
When it is determined that the marks are overlapped, the control unit 81 changes the added value in the number of times the calibration sheet is used according to the overlapping state of the marks. Since it is determined that the marks are overlapped by the density of the marks, it is desirable that the marks have a halftone and uniform density.

  When the sensor used in the image reading unit 70 is based on the regular reflection light detection method, the value of the sensor varies depending on the mark density. The higher the image density, the smaller the sensor value, and the lower the image density, the greater the sensor value.

Next, the operation of the image forming apparatus according to the second embodiment will be described.
In the second embodiment, the same process as the calibration process shown in FIG. 3 is performed. In the second embodiment, instead of the process in step S5, the use count process shown in FIG. 7 is performed. Done.

The control unit 81 initializes a counter for the number of times of use to 0 (step S31).
Next, the control unit 81 acquires the sensor value of the mark area of the calibration sheet read by the image reading unit 70 (step S32). The control unit 81 acquires the smallest value (sensor value in the high density region) among the sensor values in the mark region.

Next, the control unit 81 determines whether or not the acquired sensor value is greater than 300 (step S33). Here, 300 is used as the reference value of the sensor value when determining whether or not the marks overlap, but the value is not limited to this value.
When the sensor value is greater than 300 (step S33; YES), that is, when the density of the mark area is less than a predetermined value (when the density of the mark is relatively low), the control unit 81 sets the count addition value. 1 (step S34).

  In step S33, when the sensor value is 300 or less (step S33; NO), that is, when the density of the mark area is equal to or higher than a predetermined value (when the mark density is relatively high), the control unit 81 It is determined that the marks overlap (step S35), and the count addition value is set to 2 (step S36).

  After step S34 or step S36, the controller 81 adds the count addition value to the counter for the number of times of use (step S37).

  Next, the control unit 81 determines whether or not there is another mark area in the calibration sheet reading data obtained by the image reading unit 70 (step S38). If there is another mark area (step S38; YES), the process returns to step S32, and the process is repeated for the other mark area.

  In step S38, when there is no other mark area (step S38; NO), the use frequency counting process ends.

  FIG. 8 shows an example of a calibration sheet 300 in which a part of the mark overlaps. The margin areas 301 and 302 of the calibration sheet 300 include mark areas M11 to M13. The mark area M11 includes low density areas 303 and 304 and a high density area 305. The high density area 305 is a place where two marks overlap. That is, two mark marks formed at different timings (a mark formed in the low concentration region 303 and the high concentration region 305 and a mark formed in the low concentration region 304 and the high concentration region 305) are connected to the mark region M11. Is configured. For the mark area M11, the count addition value is set to 2 based on the sensor value obtained from the high density area 305. In FIG. 8, the illustration of the calibration image is omitted.

As described above, according to the second embodiment, when the density of the mark is equal to or higher than a predetermined value, it is determined that the marks are overlapped, so that an error in counting the number of marks can be prevented. Can do.
Further, since the addition value in the number of times of use of the calibration paper is changed according to the degree of overlap of the marks, the number of marks, that is, the number of times of use of the calibration paper can be accurately grasped even when the marks are overlapped. .

In the above-described use count processing, the determination when two marks are overlapped has been described. However, by providing a plurality of reference values for determining the difference in density from the sensor characteristics of the image reading unit 70, You may judge the overlap of three or more marks.
Further, it may be determined that the marks overlap based on the area of the mark region.

[Third Embodiment]
Next, a third embodiment to which the present invention is applied will be described.
Since the image forming apparatus according to the third embodiment has the same configuration as that of the image forming apparatus 100 according to the first embodiment, FIG. 1 and FIG. 2 are used, and the configuration is illustrated and described. Omitted. Hereinafter, a configuration and processing characteristic of the third embodiment will be described.

  Each time the control unit 81 causes the image forming unit 40 to form a mark, the condition of the color or shape of the mark is switched. Specifically, the control unit 81 changes an item different from the item changed in the previous mark formation condition.

  The storage unit 82 stores mark formation change conditions. The mark formation change condition includes the mark formation condition (color / shape) of the last time and the previous mark formation condition (color / shape).

Next, the operation of the image forming apparatus according to the third embodiment will be described.
In the third embodiment, the same processing as the calibration processing shown in FIG. 3 is performed. In the third embodiment, the processing shown in FIG. 9 is performed between the processing in step S2 and the processing in step S3. A mark formation condition determination process is performed.

The control unit 81 reads the previous mark formation change condition from the storage unit 82 (step S41).
Next, the control unit 81 determines whether or not the change item is a color based on the previous mark formation change condition and the previous mark formation condition based on the previous mark formation change condition (step S42).

When the previous change item is a color (step S42; YES), the control unit 81 sets the change item for determining the current mark formation condition as a shape (step S43).
On the other hand, if the previous change item is not a color (step S42; NO), the control unit 81 sets the change item for determining the current mark formation condition as a color (step S44).

  After step S43 or step S44, the control unit 81 changes the change item to determine the mark formation condition (step S45). For example, when the change item is a shape, the control unit 81 changes the shape from the previous mark and determines the current mark formation condition (square, diamond, circle, etc.). Further, when the change item is color, the control unit 81 changes the color from the previous mark and determines the current mark formation condition.

Next, the control unit 81 stores the current mark formation change condition in the storage unit 82 (step S46). The current mark formation change condition includes the previous mark formation condition and the current mark formation condition.
This completes the mark formation condition determination process.

  In step S3 (see FIG. 3), the control unit 81 controls the image forming unit 40 to place the mark determined in the mark formation condition determination process at the position determined in the calibration sheet mark position determination process A. Marks are formed under the formation conditions.

  As described above, according to the third embodiment, every time a mark is formed in the image forming unit 40, the condition of the color or shape of the mark is switched, so that the previous mark and the current mark are different. can do. If there is a difference in color and shape between the previous mark and the current mark, even if the marks overlap, it is easy to recognize individual marks, and thus the number of uses can be easily counted.

In the above mark formation condition determination process, the case of changing an item different from the previously changed item has been described. However, both the color and shape may be changed from the previous mark, or the same as the previously changed item. It is good also as changing an item.
Further, since the number of times of use is easier when the mark position is different, it is desirable to change the mark position each time a mark is formed.

[Fourth Embodiment]
Next, a fourth embodiment to which the present invention is applied will be described.
The image forming apparatus according to the fourth embodiment has the same configuration as that of the image forming apparatus 100 according to the first embodiment. Therefore, FIG. 1 and FIG. 2 are used, and the configuration is illustrated and described. Omitted. Hereinafter, a configuration and processing characteristic of the fourth embodiment will be described.

  When the sheet set in the sheet feeding unit 50 is a calibration sheet used for the calibration of the image reading unit 70, the control unit 81 corresponds to the number of times of use based on the unique information of the image forming apparatus in the blank area of the calibration sheet. The position of the mark to be determined is determined, the image forming unit 40 is caused to form the mark at the determined position of the calibration sheet, and the image reading unit 70 is caused to read the formed mark. As the unique information of the image forming apparatus, the serial number of the image forming apparatus is used.

With reference to FIG. 10, a method for specifying a position in the margin area on the calibration sheet 400 will be described. In FIG. 10, the illustration of the calibration image is omitted.
In the main scanning direction, areas (margin areas) where marks can be formed are two belt-like areas P and Q at both ends of the calibration sheet 400.
For the sub-scanning direction, the area where the mark can be formed (margin area) is divided into 10, and the positions (areas 1 to 10) for forming the mark are assigned according to the numbers 1 to 10.

Next, the operation of the image forming apparatus according to the fourth embodiment will be described.
In the fourth embodiment, the same processing as the calibration processing shown in FIG. 3 is performed. In the fourth embodiment, the mark shown in FIG. 11 is used instead of the mark position determination processing A in step S2. Position determination processing B is performed. The mark position determination process B is a process for determining the mark position from the serial number of the image forming apparatus.

  First, the control unit 81 acquires the serial number of the image forming apparatus stored in the storage unit 82 (step S51).

  Next, the control unit 81 acquires the second digit number from the end of the manufacturing number (step S52). Here, the control unit 81 determines whether or not the second digit from the end of the serial number is an even number (step S53).

If the second digit from the end of the serial number is an even number (step S53; YES), the control unit 81 determines the position in the main scanning direction as the region P (step S54).
In step S53, when the second digit from the end of the serial number is an odd number (step S53; NO), the control unit 81 determines the position in the main scanning direction as the region Q (step S55).

After step S54 or step S55, the control unit 81 acquires the first digit from the end of the serial number (step S56).
The controller 81 determines the position in the sub-scanning direction based on the first digit from the end of the serial number (step S57). Specifically, the control unit 81 determines the sub-scanning direction area corresponding to the same number as the first digit from the end of the serial number. However, if the first digit from the end of the serial number is 0, the position in the sub-scanning direction is determined as the area 10.
This completes the mark position determination process B.

  When the serial number is “*** 25”, the second digit “2” from the end of the serial number is an even number, and the first digit from the end of the serial number is “5”. As shown in FIG. 10, marks M <b> 21 are formed at the positions of the main scanning direction region P and the sub-scanning direction region 5.

As described above, according to the fourth embodiment, since the position of the mark to be formed on the calibration sheet is determined based on the unique information of the image forming apparatus, it is possible to suppress the overlap of the mark positions. In addition, it is possible to disperse the positions when marks corresponding to the number of times of use are formed on the calibration paper used for calibration of the image reading unit 70.
This is particularly effective when the image reading unit 70 is calibrated in order using the same calibration sheet for a plurality of image forming apparatuses having different production numbers, such as at the time of product shipment.

[Fifth Embodiment]
Next, a fifth embodiment to which the present invention is applied will be described.
The image forming apparatus according to the fifth embodiment has the same configuration as that of the image forming apparatus 100 shown in the first embodiment. Therefore, FIG. 1 and FIG. 2 are used, and the configuration is illustrated and described. Omitted. Hereinafter, a configuration and processing characteristic of the fifth embodiment will be described.

The controller 81 determines the current mark position based on the unique information of the image forming apparatus and the previous mark position. The method for specifying the position in the margin area on the calibration sheet is the same as in FIG.
The control unit 81 shifts the current mark position from the previous mark position.

  The storage unit 82 stores the position of the previously formed mark.

Next, the operation of the image forming apparatus according to the fifth embodiment will be described.
In the fifth embodiment, the same processing as the calibration processing shown in FIG. 3 is performed. In the fifth embodiment, the mark shown in FIG. 12 is used instead of the mark position determination processing A in step S2. A position determination process C is performed. The mark position determination process C is a process for shifting the current mark position from the previous mark position.

  First, the control unit 81 reads the previous mark position (main scanning direction region, sub-scanning direction region) stored in the storage unit 82 (step S61). Here, the control unit 81 determines whether or not the previous mark position has been stored in the storage unit 82, that is, whether or not the previous mark position has been successfully read (step S62). In the image forming apparatus according to the fifth embodiment, when the calibration process is performed for the first time, the previous mark position is not stored in the storage unit 82.

  When the previous mark position is stored in the storage unit 82 (step S62; YES), the control unit 81 acquires the serial number of the image forming apparatus stored in the storage unit 82, and ends the serial number. To obtain the first digit number (step S63). Here, the control unit 81 determines whether or not the first digit from the end of the serial number is 0 (step S64).

If the first digit from the end of the serial number is 0 (step S64; YES), the control unit 81 changes the position in the main scanning direction to a region different from the previous time (step S65). Specifically, when the previous position in the main scanning direction is the region P, the control unit 81 sets the current position in the main scanning direction as the region Q, and the previous position in the main scanning direction as the region Q. If there is, the current position in the main scanning direction is set as a region P.
Next, the control unit 81 sets the position in the sub-scanning direction as an area obtained by adding 1 to the number in the previous sub-scanning direction area (step S66).

  In step S64, when the first digit from the end of the production number is not 0 (step S64; NO), the control unit 81 produces the position in the sub-scanning direction as the number in the previous sub-scanning direction area. An area corresponding to a number obtained by adding a value obtained by dividing the first digit from the end of the number by 2 is set (step S67). When the first digit from the end of the serial number is not 0, the position in the main scanning direction is set to the same area as the previous time.

  In the calibration paper 500 shown in FIG. 13, the method for designating the area (margin area) where the mark can be formed is the same as in FIG. As shown in FIG. 13, when the previous mark M31 is the main scanning direction area P and the sub scanning direction area 5 and the serial number is “*** 25”, the first digit from the end of the serial number is shown. Since the number is not 0, the position of the mark M32 in the main scanning direction is the same as the previous area P, and the position in the sub-scanning direction is the previous area “5”. A value “7.5” obtained by adding “2.5” obtained by dividing “5” by 2 is obtained. In FIG. 13, the calibration image is not shown.

  In step S62, when the previous mark position is not stored in the storage unit 82 (step S62; NO), the control unit 81 performs a mark position determination process B (see FIG. 11) (step S68). Since the mark position determination process B has been described in the fourth embodiment, a description thereof will be omitted.

After step S66, step S67 or step S68, the control unit 81 stores the current mark position (main scanning direction region, sub-scanning direction region) in the storage unit 82 (step S69).
This completes the mark position determination process C.

As described above, according to the fifth embodiment, since the current mark position is determined based on the unique information of the image forming apparatus and the previous mark position, the overlapping of the mark positions is suppressed. can do.
Further, by shifting the position of the current mark from the position of the previous mark, the number of times of use can be easily counted.

The description in each of the above embodiments is an example of the image forming apparatus according to the present invention, and the present invention is not limited to this. The detailed configuration and detailed operation of each part constituting the apparatus can be changed as appropriate without departing from the spirit of the present invention.
Moreover, it is good also as performing combining the characteristic process in each embodiment.

  In each of the above embodiments, the case has been described in which it is determined whether or not the next sheet fed from the sheet feeding unit 50 is a calibration sheet based on the tray setting information stored in the storage unit 82. Each of the paper feed trays T1 to T3 is provided with a sensor for detecting the paper type or thickness of the paper, and when the sensor detects that the paper type or thickness corresponds to the calibration paper, the paper feed unit 50 It may be determined that the next paper to be fed is a calibration paper. Further, identification information (such as a mark) indicating that the sheet is a calibration sheet is given to the calibration sheet, and a sensor for reading the identification information on the calibration sheet is provided in each of the sheet feeding trays T1 to T3. It may be determined that the next paper to be fed is a calibration paper.

  In the above description, an example in which a ROM is used as a computer-readable medium storing a program for executing each process is disclosed, but the present invention is not limited to this example. As other computer-readable media, a non-volatile memory such as a flash memory and a portable recording medium such as a CD-ROM can be applied. A carrier wave may be applied as a medium for providing program data via a communication line.

20 Display unit 40 Image forming unit 50 Paper feed unit 70 Image reading unit 81 Control unit 82 Storage unit 100 Image forming apparatuses T1 to T3 Paper feed tray

Claims (10)

An image forming unit for forming an image on paper;
An image reading unit that is provided downstream of the image forming unit and reads an image formed on the paper by the image forming unit;
A paper feeding unit for feeding paper to the image forming unit;
When the paper set in the paper feeding unit is a calibration paper used for calibration of the image reading unit, a mark position corresponding to the number of times of use is determined using a random number in a blank area of the calibration paper, A control unit that causes the image forming unit to form the mark at the determined position of the calibration sheet, and causes the image reading unit to read the formed mark;
An image forming apparatus comprising: An image forming unit for forming an image on paper;
An image reading unit that is provided downstream of the image forming unit and reads an image formed on the paper by the image forming unit;
A paper feeding unit for feeding paper to the image forming unit;
The position of the mark corresponding to the number of uses in the margin area of the calibration paper based on the unique information of the image forming apparatus when the paper set in the paper feeding unit is a calibration paper used for calibration of the image reading unit A control unit that causes the image forming unit to form the mark at the determined position of the calibration sheet and causes the image reading unit to read the formed mark;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein the control unit obtains the number of times the calibration sheet is used based on the number of marks read by the image reading unit.   The image forming apparatus according to claim 3, wherein the control unit determines that the marks overlap when the density of the mark read by the image reading unit is equal to or higher than a predetermined value. .   5. The image according to claim 4, wherein, when it is determined that the marks overlap, the control unit changes an addition value in the number of times of use of the calibration sheet according to a degree of overlap of the marks. Forming equipment.   The control unit calculates a remaining number of times of use of the calibration sheet from the acquired number of times of use of the calibration sheet, and notifies the user of the calculated remaining number of times of use. The image forming apparatus according to claim 1.   7. The control unit according to claim 3, wherein when the number of times the acquired calibration sheet is used exceeds a predetermined upper limit value, the control unit notifies the user to that effect. 8. The image forming apparatus described.   The image forming apparatus according to claim 1, wherein the control unit switches a condition of a color or a shape of the mark every time the image forming unit forms the mark.   The image forming apparatus according to claim 2, wherein the control unit determines the position of the current mark based on the unique information of the image forming apparatus and the position of the previous mark.   The image forming apparatus according to claim 9, wherein the control unit shifts the position of the current mark from the position of the previous mark.

Images