JP2014104623A - Image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent adhesion of an ink to a carrying system from a printed sheet and ink transfer blotting in printing.SOLUTION: In an image formation apparatus 1, a sheet P is carried while heated by a heating roller 10 capable of temperature adjustment, printed by an ink jet head 12 and discharged. Control means 30 has temperature control basic data including outside diameters dof dots D of a test pattern A and a basic temperature Tin storage means. The control means prints the test pattern A on the same sheet to obtain the outside diameters dof the dots D before printing and calculates a set temperature for the print sheet from the outside diameters dof the dots D and the control basic data. In printing, a sheet is heated by the heating roller heated to a set temperature and subjected to printing. An ink transferred to the print sheet permeates the print sheet and evaporates and dries quickly, thus preventing staying of undried ink behind on the surface and blotting of the carrying means with ink.

Description

  The present invention determines the degree of ink bleeding on the printing paper based on the result of the test printing, and heats the printing paper at the time of printing at a temperature corresponding to the determination result to promote ink penetration and drying. The present invention relates to an image forming apparatus capable of preventing ink stains on a conveyance path through which printed printing paper is conveyed and reducing ink stains during printing of the printing paper.

  Patent Document 1 below discloses an invention of an ink drying system for a stencil printing machine that can sufficiently dry ink by increasing the heating time. The ink drying system 50 heats the paper when the printed paper is sandwiched and transported by the paper transport means 16 to dry the printing ink on the paper. The paper transport means attaches the printed paper to the continuous contact member 52 whose contact surface with the printed paper continuously extends along the paper transport path, and the contact surface of the continuous contact member with the printed paper. Pressure member 16 to be energized. The heating means heats at least the continuous contact member 52.

JP 2001-232761 A

  The invention disclosed in Patent Document 1 includes means for drying printed paper after printing, but the conveying device that transports the printed printing paper from the printing means to the drying means is stained with ink on the printing paper. Inevitably, the subsequent printed printing paper passes through the transport device and is discharged, which causes a problem that ink stains are transferred from the transport device to the printed printing paper.

  Further, as in the invention disclosed in Patent Document 1, in the method of drying by directly contacting the drying means with the printing paper, the ink adheres to the contact portion with the printing paper. In order to prevent the ink from transferring to the subsequent printing paper, an ink transfer prevention material such as oil must be applied. However, there may be a problem of secondary smearing that the oil or the like may contaminate the printing paper separately from the ink, and the cost of oil or the like as a consumable item increases, and the oil or the like is supplied to the contact portion. There is also a problem that the equipment configuration for doing so becomes complicated and the manufacturing cost increases.

  The present invention has been made in view of various problems in the prior art as described above, and requires a device for drying ink on printed printing paper, an ink transfer prevention material such as oil, and a supply device thereof. Therefore, regardless of the type of printing paper, it is possible to effectively prevent ink from adhering to the transport device from printed printing paper by simple means, and to prevent ink transfer stains from being attached to the printing paper during printing. An object of the present invention is to provide an image forming apparatus capable of preventing the above.

An image forming apparatus according to claim 1 is provided.
Image forming means for forming an image by transferring ink to printing paper; and
Test pattern printing control means for controlling the image forming means to print a test pattern on printing paper;
Determining means for determining the degree of ink bleeding on the printing paper from the test pattern printed on the printing paper;
Storage means for storing temperature control basic data indicating the relationship between the degree of ink bleeding on the printing paper and the paper temperature;
A temperature control means for calculating a set temperature at which the printing paper is heated based on the degree of ink bleeding determined by the determination means from the test pattern and the temperature control basic data of the storage means;
Heating means for heating printing paper to the set temperature calculated by the temperature control means before image formation by the image forming means;
It is characterized by having.

The image forming apparatus according to claim 2 is the image forming apparatus according to claim 1,
The temperature control basic data prepared in advance for each of a plurality of types of printing paper used for image formation is stored in the storage means.

The image forming apparatus according to claim 3 is the image forming apparatus according to claim 2,
The test pattern printing control means causes the image forming means to print the test pattern on the printing paper with a predetermined amount of ink so that dots are formed according to the degree of ink bleeding on the printing paper;
The determination means outputs the dot size as a determination result of the degree of ink bleeding on the printing paper,
The storage means stores, as the temperature control basic data, data relating to the relationship between the dot size in the test pattern formed on the printing paper and the paper temperature,
The temperature control unit calculates the set temperature based on the dot size determined from the test pattern by the determination unit and data relating to the relationship between the dot size and the paper temperature stored in the storage unit. It is characterized by.

The image forming apparatus according to claim 4 is the image forming apparatus according to claim 3,
The set temperature is corrected based on a printing rate indicating a ratio of an actual image area to an image formable area of the printing paper.

The image forming apparatus according to claim 5 is the image forming apparatus according to claim 3,
When the image forming unit is an inkjet head, the set temperature is corrected based on a driving amount indicating the number of ink drops supplied to one position in an image on a printing paper.

  According to the image forming apparatus of the first aspect, the test pattern printing control unit controls the image forming unit to test the same type of printing paper as that used in actual printing immediately before actual printing. Print the pattern. The determination unit determines the degree of ink bleeding on the printing paper from the test pattern formed on the printing paper. The temperature control means uses the ink bleeding degree determined from the test pattern by the determination means and the temperature control basic data stored in advance in the storage means, and sets the set temperature when the printing paper is heated by the heating means during image formation. calculate. Here, the degree of ink bleeding determined from the test pattern by the determination means is an index representing the degree of ink bleeding that can be read from the test pattern printed on the printing paper, and the temperature control basic data is the printing paper. Is a data showing the relationship between the degree of ink bleeding and the paper temperature. When actual printing is performed after printing and determination of the test pattern, the printing paper is heated to the set temperature by the heating unit, so that the ink transferred from the image forming unit to the printing paper is warmed to the set temperature. It quickly evaporates and dries while quickly penetrating into the printing paper. As a result, image formation is performed in a state where the bleeding is suppressed to an acceptable level, and an image with good resolution can be obtained, and undried ink does not remain on the surface of the printing paper, and the image forming apparatus Even if the inside is transported, the ink does not adhere to the equipment such as the transporting means, and the possibility that the subsequent printed paper will be soiled by the transfer of ink is reduced.

  According to the image forming apparatus of the second aspect, the temperature control basic data is prepared for each of a plurality of types of printing paper used for image formation, and these are stored in advance in the storage unit. When the printing paper to be actually used is selected and the test pattern is printed immediately before the image formation, and this is read, the control means can automatically calculate the set temperature for heating the printing paper at the time of image formation. it can.

  According to the image forming apparatus of the third aspect, when the test pattern is printed on the printing paper, the size of the dots formed is larger as the printing paper is more likely to bleed ink and the printing conditions are more likely to bleed ink. growing. When this test pattern is read into the image forming apparatus, the determination unit outputs the dot size as a determination result of the degree of ink bleeding on the printing paper. Based on this dot size and basic data for temperature control, that is, data relating to the relationship between the dot size and the paper temperature stored in the storage means, a set temperature for heating the printing paper in actual printing is determined. Calculated by the temperature control means.

  According to the image forming apparatus of the fourth aspect, the set temperature for heating the printing paper obtained from the test pattern printing result and the temperature control basic data is corrected based on the printing rate in actual printing. That is, when the printing rate is larger than the predetermined reference value, more ink is transferred to the printing paper, so that the set temperature is increased to further promote ink penetration, and the ink is evaporated more quickly. It can be controlled to dry.

  According to the image forming apparatus described in claim 5, when the image forming means is an ink jet head, the set temperature for heating the printing paper obtained from the test pattern printing result and the temperature control basic data is set. The correction is made based on the amount, that is, the number of ink drops supplied to one position in the image on the printing paper. That is, when the driving amount is larger than the predetermined reference value, more ink is transferred to the printing paper, so that the set temperature is increased to further promote the penetration of the ink, and the ink evaporates more quickly. It can be controlled to dry.

1 is an external perspective view of an image forming apparatus according to an embodiment. 1 is a schematic configuration diagram illustrating a sheet conveyance system of an image forming apparatus according to an embodiment. 1 is a system configuration diagram of an image forming apparatus according to an embodiment. FIG. 2 is a diagram illustrating an example of a test pattern formed on a printing paper in the image forming apparatus according to the embodiment, and a reading unit and method thereof. FIG. 5 is a diagram illustrating that when a test pattern is formed on a printing paper in the image forming apparatus according to the embodiment, the outer diameter of a dot at the center of the test pattern varies depending on the state of ink bleeding. 3 is a flowchart illustrating an overall control function of the image forming apparatus according to the embodiment. 5 is a flowchart illustrating a procedure for setting print optimization in the control function of the image forming apparatus according to the embodiment. 6 is a flowchart illustrating a printing procedure in a printer mode of a control function of the image forming apparatus according to the embodiment.

An image forming apparatus according to an embodiment of the present invention will be described with reference to FIGS.
First, the basic configuration of the image forming apparatus of the present embodiment will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the image forming apparatus 1 is printed by a printing apparatus 2 that forms an image or a test pattern on printing paper, a paper feeding apparatus 5 that supplies the printing paper to the printing apparatus 2, and the printing apparatus 2. The finisher device 3 performs processing such as sorting and binding on the printed paper, and the reading device 4 such as a scanner for reading a document image or a test pattern.

  As shown in FIG. 2, the paper feeding device 5 can feed the printing paper P stacked on the paper table 6 that can move up and down to the printing device 2 by the primary paper feeding roller 7. The printing paper P sent to the printing apparatus 2 reaches the secondary paper feeding roller 9 through the guide plate 8 and is supplied one by one at a predetermined timing. A pair of heating rollers 10 is provided downstream of the secondary paper feed roller 9 as a heating means for the printing paper P. At least one of the heating rollers 10 is provided with a heat source such as an IH heater, and can be heated to a desired temperature by sandwiching and transporting the printing paper P before printing. Note that the upper limit of the heating temperature of the printing paper P is approximately 85 ° C. in consideration of the general material of the printing paper P and the like. A belt conveyor 11 serving as a conveying means that is a part of the conveying system is provided downstream of the heating roller 10. Above the latter half of the heating roller 10, ink is ejected onto the printing paper P that is being conveyed to form an image. An ink jet head 12 is provided as image forming means for forming the image. The inkjet head 12 has four colors of cyan, magenta, yellow, and black, and can support full-color image formation. Further, a discharge roller 13 as a conveying means that is a part of the conveying system is provided adjacent to the belt conveyor 11 in the conveying direction, and the printing paper P on which image formation has been completed can be sent to the finisher device 3. It can be done.

  In the configuration example of the present embodiment, the printing paper P supplied from the paper tray 6 is conveyed by the belt conveyor 11, an image is formed on the upper surface by the inkjet head 12, and is sent as it is to the finisher device 3 by the discharge roller 13. It has become. However, a second conveyance path that forms a loop shape as a whole is connected to both ends of the conveyance path centered on the belt conveyor 11, and a second discharge roller and a sheet discharge are provided above the second conveyance path. A stand is provided, and one end of a linear switchback transport path on which the printing paper P can reciprocate is connected to the second transport path, and switching means for switching each path is further provided at a key point. May be. Each of these transport paths has a guide path for guiding the print paper P and a number of transport rollers provided along the guide path for transporting the print paper P therebetween. With such a configuration, the printing paper P on which an image is formed on the front surface is sent to the loop-shaped conveyance path, and is reversed from the front and back to be discharged from the second discharge roller to the discharge table with the printing surface facing downward. Or the printing paper P on which an image has been formed is reciprocated in the switchback conveyance path through the loop-shaped conveyance path so as to be reversed so that the printing surface faces downward and the unprinted back surface faces upward. The printing paper P on which the image is formed and printed on both sides can be sent out to the finisher device 3 by the discharge roller 13.

  As described above, the image forming apparatus 1 of the present embodiment forms an image by transferring ink to the printing paper P with the inkjet head 12 while conveying the printing paper P by the conveying means of the conveying system. This is a device for performing post-processing such as stapling. If ink remains on the surface of the printed printing paper P without being dried, a transport system, for example, various transport paths, roller transport means such as the discharge roller 13, etc. Ink adheres to these when passing, and when the subsequent printing paper P passes through the transport system, ink is transferred from the transport roller, guide path, discharge roller 13 and the like, and the print paper P or its image is soiled. It is possible to end up. Therefore, in the present embodiment, the heating roller 10 is provided in front of the ink jet head 12 to heat the printing paper P before printing, whereby the state in which undried ink remains on the surface of the printing paper P after printing is printed. It will be resolved soon. In this embodiment, the temperature setting or temperature control of the heating roller 10 for heating the printing paper P before printing to an appropriate temperature is referred to as “print optimization setting (or print optimization control)” in the present embodiment.

  With such a print optimization setting, when the heating roller 10 is heated to an appropriate temperature (hereinafter referred to as a set temperature) and the printing paper P before printing is heated to the set temperature, the ink jet head 12 transfers to the printing paper P. The ink thus obtained can be quickly evaporated and dried while being warmed to a set temperature and efficiently penetrating into the printing paper P. As a result, an image is formed with ink while being suppressed to an acceptable level of bleeding, and an image with good resolution can be obtained, and undried ink does not remain on the surface of the printing paper P. . For this reason, even if the image forming apparatus 1 is conveyed, the ink does not adhere to devices such as the conveying means, and the possibility that the subsequent printed printing paper P is soiled by the transfer of ink is reduced.

  Hereinafter, referring to FIG. 3 to FIG. 8, the penetration of the ink is promoted by preventing the ink from spreading by heating the printing paper P, and the image formed on the surface of the printing paper P is dried to the conveying means. A control function for suppressing ink adhesion will be described in detail.

  FIG. 3 is a functional block diagram of the image forming apparatus 1 of the present embodiment. The reading device 4 includes a scanner or the like as a reading unit, and includes an ADF unit 15 and an optical system reading unit 16. Further, a drive motor unit 17 for driving a mechanism system included in the reading unit and a mechanism system control unit 18 for controlling the drive motor unit 17 are provided. Furthermore, the reading device 4 performs image processing on the image data read by the ADF unit 15 and the optical system reading unit 16 and image data obtained by reading the ADF unit 15 and the optical system reading unit 16. A shading correction unit 20 that provides shading correction as necessary is provided.

  As illustrated in FIG. 3, the printing apparatus 2 includes an inkjet head 12 (IJ head) as an image forming unit, an ink control unit 21 that controls ink supply to the inkjet head 12, and ink supplied to the inkjet head 12. An ink storage unit 22 is provided. In addition, the printing apparatus 2 inputs an operation instruction and data to the image processing / RIP unit 23 that performs processing for making the image data of the image to be formed by the inkjet head 12 into a form suitable for printing, Also provided is a panel operation unit 24 for displaying various information such as the status of the apparatus, input results, and warnings. The panel operation unit 24 may also serve as an input unit and a display unit for the reading device 4 as well as the printing device 2. In addition, the printing apparatus 2 includes an IH heater (also referred to as a heating heater) 25 that is a heating source provided in the heating roller 10 as a heating unit of the printing paper P described above, and a heater control unit 26 that controls the IH heater 25. ing. In addition, the printing apparatus 2 includes an input / output unit for performing communication between the PC / IF unit 27 that is an input unit for receiving information such as image data from an external PC (personal computer) and an external network. A LAN / IP control unit 28 is provided.

  As shown in FIG. 3, the printing apparatus 2 includes a drive motor unit 31 that drives a conveyance system such as the belt conveyor 11, a power supply unit 32 that supplies electricity to a power consumption part including the drive motor unit 31, and It has a control unit 30 that controls each part and the whole of the apparatus. The power supply unit 32 may also serve as a power source for the reading device 4 as well as the printing device 2. The control unit 30 may perform all or part of the control of the reading device 4 and the finisher device 3 as well as the printing device 2.

Next, specific contents of the heating control of the printing paper P using the heating roller 10 realized by the control unit 30 will be described in more detail with reference to FIGS. 4 and 5.
FIG. 4 is a diagram illustrating an example of a test pattern formed on the printing paper P in the image forming apparatus 1 of the present embodiment, and a reading unit and method thereof. When the ink is transferred to the printing paper P by the inkjet head 12, the type of the ink, the type of the printing paper P (fiber density, presence or absence of surface treatment, type of processing agent, etc.), and environmental conditions (temperature and humidity) Etc.) or the like, the degree of bleeding of the ink with respect to the printing paper P changes. As the ink enters between the fibers of the printing paper P and evaporates and dries with time, the temperature of the printing paper P is generally relatively high when the printing paper P and the type of ink are fixed. As the ink is warmed and sucked into the fibers of the printing paper P, the amount remaining on the surface decreases, and at the same time, the ink is warmed and evaporated and dried, so that it becomes difficult to adhere to the transport system. . On the other hand, if the temperature of the printing paper P is relatively low, the ink is difficult to dry due to the reverse action and tends to remain on the surface of the printing paper P. As a result, the ink tends to adhere to the transport system.

  In order to objectively evaluate the degree of bleeding of such ink on the printing paper P, in this embodiment, as shown in an enlarged view drawn with a white arrow in FIG. 4, a pattern in which small black circles are arranged in a straight line A test pattern A is used, in which the patterns are arranged radially. According to this test pattern A, the closer to the center, the shorter the intervals between the black circles and the closer the arrangement of the black circles. As shown schematically in FIG. 5, when the ink spreads, the center of the radial array The portion looks like a black circle larger than one black circle (this black circle is particularly called a dot D). That is, a black circle having a larger outer shape than a single black circle without bleeding is visible. When such a test pattern A is formed of ink, the dot D at the center portion appears to appear larger as the degree of ink bleeding increases. FIG. 5 shows the size of the dot D when the blur is relatively small, that is, the outer diameter of the dot D is d1, the outer diameter of the dot D when the blur is relatively intermediate, and the blur is relative. In this example, the outer diameter of the dot D when it is large is shown as d3. Therefore, the order of the outer diameter corresponding to the size of the dot D is d1 <d2 <d3. In the present embodiment, the outer diameter d of the dot D appearing at the center of the test pattern A is used as an index of the degree of bleeding indicating the ease of ink bleeding on the printing paper P.

  Then, such a test pattern A is printed under a predetermined condition immediately before printing, the degree of ink bleeding on the printing paper P is evaluated by the outer diameter d of the dot D, and this is used to control the temperature of the heating roller 10 prepared in advance. Compared with the basic data, it is possible to obtain the heating temperature of the printing paper P by the heating roller 10 so that the bleeding is within an allowable range and the ink does not dry and remain on the surface of the printing paper P after printing. . The predetermined condition for printing the test pattern A includes that the amount of ink (or the number of ink drops) used when printing the test pattern A is a predetermined amount.

A method for acquiring the temperature control basic data of the heating roller 10 will be specifically described.
First, the room temperature of the room in which the image forming apparatus 1 is installed is set to an appropriate basic temperature T _B (for example, 25 ° C.), and the process waits until the image forming apparatus 1 and the printing paper P become room temperature. Thereafter, the control unit 30 controls the printing apparatus 2 to print the test pattern A for each type of printing paper P used for printing without using the heating roller 10. Further, the control unit 30 reads each printing paper P on which the test pattern A is printed while being conveyed along the optical system reading unit 16 of the reading device 4 as shown in FIG. acquires d _B as the determination result of bleeding of the ink on the printing paper P. As shown in FIG. 4, when a plurality of test patterns A are printed on one printing paper P and the outer diameter of the dots D is read, an average value may be taken. This basic temperature T _B and the outer diameter d _B (or the average value thereof) of the dot D at that time are controlled as temperature control basic data for controlling the heating roller 10 when an image is printed on the type of printing paper P. It is stored in the storage means in the unit 30 and used to control the temperature of the heating roller 10. Incidentally, the outer shape d _B of the dot D in the basic temperature T _B is made also to correspond to the resolution of the acceptable image at the time of image formation.

A method for printing the test pattern A performed immediately before printing will be specifically described.
Immediately before printing, the control unit 30 controls the inkjet head 12 under the same conditions as actual printing, and prints the test pattern A on the printing paper P that is the same as that used for printing and is not heated by the heating roller 10. is allowed, further which was read by the reading device 4, and outputs a contour d _n of the dot D of the center as the determination result of bleeding of the ink on the printing paper P. Then, the control unit 30 uses the outer diameter d _B and the basic temperature T _B (for example, 25 ° C.) of the temperature control basic data stored in the storage unit, and the outer diameter data d _n of the dot D acquired as a determination result. The temperature at which the heating roller 10 is heated during image formation (hereinafter referred to as the set temperature T _n ) is calculated. In more detail, the outer diameter d _n of dots D obtained by the printing of the test pattern A immediately before printing is larger than the outer diameter d _B of the temperature control basic data, as compared with the time of acquisition of the temperature control basic data it is considered the ink is in the prone condition bleeding, to print an image by heating the printing paper P in the basic temperature T higher set temperature T _n than _B, and which reduces the bleeding of images. For example, it is possible to calculate the set temperature T _n = an arithmetic such as (d _n / d _B) × basic temperature T _B, higher set temperature T _n than the basic temperature T _B.

If the heating roller 10 is set to such a set temperature T _n and the printing paper P is heated at such a setting temperature T _n during actual image formation, the ink transferred from the inkjet head 12 to the printing paper P is set. While being warmed to the temperature T _n and efficiently penetrating into the printing paper P, it quickly evaporates and dries. As a result, image formation is performed in a state where it is suppressed to an acceptable degree of bleeding, and an image with good resolution can be obtained. In addition, it is difficult for ink in a wet state to remain on the surface of the printing paper P, and to the transport system. The state of ink transfer is small. If d _n <d _B , it is not necessary to use the heating roller 10 at the time of printing, but the printing paper P is heated at a set temperature T _n that is the same as or higher than the basic temperature T _{B by a} predetermined temperature. Also good.

  As described above, in the present embodiment, the control unit 30 is a test pattern printing control unit that controls the inkjet head 12 to print the test pattern A on the printing paper P, and the test pattern A printed on the printing paper P. It is also a determination means for determining the outer diameter of the center dot D. The control unit 30 has a function of calculating temperature control basic data based on the determination of the outer diameter of the dot D by printing and reading of the test pattern A, and storage means for storing the temperature control basic data. I have. Further, the control unit 30 calculates the set temperature during printing of the printing paper P from the outer diameter of the dots D of the test pattern A obtained by printing immediately before printing and the temperature control basic data in the storage means. It is also a means.

Incidentally, when the calculation of the set temperature of the heating roller 10 described above, as the temperature control basic data, was used outer diameter d _B of the dot D in the basic temperature T _B, without using the heating roller 10 immediately before production printing printing The function data indicating the relationship between the outer diameter d _n of the dot D at the center of the test pattern A and the set temperature T _n of the heating roller 10 necessary for preventing the contamination of the transport system during actual printing is experimentally obtained. calculated advance, after obtaining the actual value of the outer diameter d _n of the dot D of the central portion to print a test pattern a immediately before printing, the value of the outer diameter d _n of the obtained data of the function d _n The set temperature T _n of the heating roller 10 may be immediately determined by substituting for. In general, the outer diameter d _n of the dot D at the center of the test pattern A formed immediately before printing and the set temperature T _{n of the} heating roller 10 necessary to prevent the conveyance system from being contaminated during actual printing. The function indicating the relationship is generally directly proportional. Thus, the relatively large outer diameter d _n of the dot D in the center of the test pattern A, when the bleeding is large, more ink bleeding the set temperature T _n of the heating roller 10 relatively high set strongly inhibited, contrary to the outer diameter d _n of the dot D in the center of the test pattern a is relatively small, if bleeding is small, and setting a relatively low set temperature T _n of the heating roller 10 Become. If the bleeding is below a predetermined allowable limit, it is considered that the ink is not left on the surface of the printing paper P after printing, and the heating by the heating roller 10 may not be performed.

  Next, the operation of the image forming apparatus 1 of the present embodiment will be described with reference to the flowchart of FIG. In addition, please refer to FIG. 1 and FIG. When an instruction is given to the panel operation unit 24 to turn on the power supply unit 32 and the printing apparatus 2 is started (S1), the control unit 30 performs initialization and self-diagnosis of the entire image forming apparatus 1 (S2). If the results of initialization and self-diagnosis are bad (S2, NO), the process proceeds to error processing (S3). If it is satisfactory (S2, YES), it is determined whether this apparatus is in a function mode such as print optimization setting or a normal operation mode other than this, and each mode is determined according to the result. Specifically, each part of the apparatus is caused to execute the operation (S4).

  In S4, when it is determined that the operation mode is not the function mode but the normal operation mode (S4, NO), the copy, printer, In each of the scanner and fax modes, each part of the reading device 4 and each part of the printing device 2 are controlled to perform actual work.

  In the copy mode in which the original image is read and copied, copy processing is performed (YES in S5, S6), and it is determined whether the execution mode of the copy processing is the normal mode or the senior mode ( S7). Here, the normal mode is a state of an apparatus that performs normal image formation, and the senior mode is a state of an apparatus that prints characters in an image after performing visibility correction processing. Visibility correction processing is a thickening process that corrects image data so that the line width of the characters in the image is thick, and brightness contrast with respect to the color of each character at least part of the periphery of each character in the image Means brightness correction processing that corrects image data so that an image with a large color is formed, and correction that makes it difficult for seniors to read characters.

  When the copy mode is the normal mode (S7, YES), a normal process for forming an image with faithful reproducibility to the read image data is performed (S8), and the copy is terminated (S9). When the copy mode is the senior mode (S7, NO), senior mode processing is performed such as forming an image in which the characters of the read image are easy to read according to the designation (S10), and the copy is finished ( S9).

Printer processing is performed in the printer mode (S11 to S16), scanner processing is performed in the scanner mode (S17 to S19), and fax processing is performed in the fax mode (S20 to S22).
Such normal operation setting, that is, switching of each normal operation mode can be performed by a touch switch of the panel operation unit 24.

  If the function mode is determined in S4 (S4, YES), the settings included in the function mode, test printing, print optimization settings, and maintenance functions are performed according to the input contents of the function settings input from the panel operation unit 24. In any of the modes, the reading device 4 and the printing device 2 are controlled to perform actual work (S30 to S61).

  The setting mode (S30, S31) is a reading of a test pattern A for controlling the number of ink droplet drops (different from the test pattern A shown in FIG. 4 for controlling the temperature of the heating roller 10 described above). This mode uses the control data related to the number of drops of ink droplets stored in the memory and the number of drops of ink droplets that are dropped during printing to set the optimum number of drops so that printing can be performed. In this mode, copy processing and printer processing in the normal operation mode can be executed in an optimal state.

  The test print mode (S19, S20) is not for printing the test pattern A for printing optimization described above or the test pattern A for controlling the number of drops of ink droplets in the setting mode. In this mode, a predetermined pattern is printed on the printing paper P in order to detect nozzle clogging.

  The print optimization setting mode (S21, S22) is intended to quickly dry the ink on the surface of the printing paper P after printing to prevent ink stains in the transport system and to perform optimal image formation. In this mode, the temperature of the heating roller 10 is set or controlled in order to heat the previous printing paper P to an appropriate temperature. In this mode, basic temperature control data necessary for control can be acquired and stored in the storage means of the control unit 30.

  In this print optimization setting mode, the test pattern A shown in FIG. 4 is printed on the printing paper P that is actually used for printing, is read by the reading device 4, and the print state of the test pattern A is determined to determine the determination data. And the determination data and the like are recorded (stored) in the storage means of the control unit 30 as basic temperature control data. The operation or control procedure of the control unit 30 and the like when acquiring the temperature control basic data in this way will be described in detail later with reference to FIG. 7, and the temperature of the determination data and the like set in this print optimization setting mode. A control procedure performed by the control unit 30 and the like during printing using the basic control data will be described in detail later with reference to FIG.

  The maintenance mode (S23, S24) is a mode for performing maintenance work of the image forming apparatus 11.

  Note that the function setting of each function as described above, that is, the switching of each function mode can be arbitrarily performed by the touch switch of the panel operation unit 24.

  Next, operations and control procedures of the control unit 30 in the print optimization setting mode will be described with reference to FIG. The print optimization setting mode is a mode for acquiring basic temperature control data necessary for controlling the temperature of the heating roller 10 during printing. This procedure is executed in the print optimization setting (S50 to S53) in the function setting mode of the overall control flow of FIG.

For temperature control basic data acquisition, the user, the room temperature first room in which the image forming apparatus 1 is installed and set to the basic temperature T _B, and then operates the touch switch panel control section 24 of the image forming apparatus 1 Select the print optimization setting mode. The type of printing paper P used here is designated. Thus, the printing of the test pattern A using a printing sheet P is specified is executed in the base temperature T _B (S100). The above means YES in step S50 in FIG. 6 and step 51 is completed.

When the test pattern A is printed on the designated printing paper P (S101, YES), the control section displays the type of the printing paper P on which the test pattern A has been printed, or the printing paper P information such as paper quality and paper thickness. together are stored in the 30 storage means (S102), the test pattern a basic when printing the temperature T _B stored in the storage means of the control unit 30 as a part of the temperature control basic data of the type of printing paper P (S103).

Next, when the user places the printing paper P on which the test pattern A is printed on the reading device 4, the image of the test pattern A is read (S104). When the printing paper P on which the test pattern A is printed is processed by the reading device 4 and the processing of one page of the printing paper on which the test pattern A is printed (S105, YES), the reading of the test pattern A is finished (S106). ). Thereafter, a test pattern A printing state determination is performed by the control unit 30 (S107). That is, the control unit 30 obtains the data of the outer diameter d _B of dots D from the center of the image of the read test pattern A, as part of the temperature control basic data, the control unit together with the data of the basic temperature T _B described above 30 (S108), and the print optimization setting mode is terminated (S109).

  Next, an actual image forming procedure using the temperature control basic data acquired in the print optimization setting mode will be described with reference to FIG. This procedure is executed in each operation such as copy (S5) and printer (S11), which are normal operation modes in the overall control flow of FIG.

  The user operates the touch switch of the panel operation unit 24 of the image forming apparatus 1 to select, for example, a copy mode, further designates the printing paper P to be used, and starts image formation. As a result, before actual image formation is performed, the test pattern A is printed using the printing paper P that is actually used for image formation under substantially the same conditions as the subsequent image formation (S200). . As the image formation is started, the heater control unit 26 is operated to start heating the IH heater 25, and heating is preliminarily started at a low temperature (S201).

Next, the printing paper P on which the test pattern A is printed is applied to the reading device 4 by the user, and the test pattern A is read and the determination data is read, and the set temperature T _n using the determination data and the temperature control basic data. Is calculated. That is, when the printing paper P on which the test pattern A is printed is processed by the reading device 4 and the reading of the test pattern A is completed, a determination is made by the control unit 30, and the control unit 30 determines from the read image of the test pattern A. reading the data of the outer diameter d _n of the dot D as the determination data (S202). Then, the control unit 30 reads the temperature control basic data including the outer diameter d _B of the dot D in the basic temperature T _B and the temperature from the storage means (S203). The control unit 30 calculates the set temperature T _n using the outer diameter d _n of this dot D and the temperature control basic data (S202).

Then, the control unit 30, a (S204), the set temperature T _n in the IH heater 25 by initiating the execution of the temperature control by controlling the heater control unit 26 for setting the temperature of the IH heater 25 to set the temperature T _n Hold (S205). Then, by controlling the drive motor unit 31, the inkjet head 12, the ink control unit 30, the image processing / RIP unit 23, etc., the actual image formation or printing for copying the original image on the designated printing paper P ( Printing) is performed (S206).

When the image formation (printing) is finished (S207, YES), the outer diameter d _n of the current dot D obtained with the imaging, the set temperature T calculated based on a temperature control basic data stored in advance _It is determined whether or not _n is stored (S208). When data of the set temperature T _n is stored in accordance with a predetermined criterion or a user instruction input from the panel operation unit 24 (S208, YES), the data can be called to the storage means of the control unit 30 (S209). If the data of the set temperature T _n is held in the storage means of the control unit 30, the test pattern A is not printed again when the same printing paper P is used and image formation is performed under the same conditions. However, it is possible to immediately form an image by heating the heating roller 10 to the set temperature T _n stored, and an image of a preferable printing result with less ink adhering to the transport system can be obtained. When the printing conditions such as the room temperature and humidity are greatly changed, even when the same printing paper P is used, the data of the set temperature T _n stored in the storage unit of the control unit 30 is used. However, good results are not always obtained. In that case, it is necessary to print the test pattern A again and calculate the set temperature T _n .

  After image formation and storage of necessary data, the control unit 30 turns off the IH heater 25 (heater heater) (S210) and ends the printing process (S211).

  In the embodiment described above, the outer diameter of the dot D read from the test pattern A printed immediately before the image formation, and the temperature control basic data (the outer diameter of the dot D at the basic temperature) acquired in advance from the experiment and stored in the storage means. ) To calculate the set temperature of the heater 25 for heating the printing paper P. However, the set temperature calculated as described above is set to another index or element so that the accuracy of control is improved and the ink that stains the transport system is less likely to remain on the printing paper P after image formation. You may make it correct | amend using.

  For example, if the amount of ink transferred to the printing paper P is large, the time required for evaporation and drying of the ink is considered to take a long time, and the possibility of soiling the transport system is expected to increase. Therefore, in such a case, the ink that transfers the set temperature of the heater 25 calculated from the outer diameter of the dots D and the temperature control basic data in the test pattern A immediately before the image formation to the printing paper P during the actual image formation. You may make it high according to the quantity of.

  For example, the set temperature may be corrected based on a printing rate indicating a ratio of an actual image area to an image formable area of the printing paper P. For example, when the reference value of the printing rate is 50% and the printing rate is equal to or less than the reference value, the set temperature of the heater 25 calculated from the outer diameter of the dot D and the temperature control basic data in the test pattern A immediately before image formation is set. If the printing rate exceeds the reference value, the set temperature is increased in proportion to the excess. That is, when the printing rate is 60% and 1.2 times the reference value of 50%, the set temperature is also 1.2 times.

  Alternatively, for example, the inkjet head 12 as the image forming unit corrects the set temperature based on the driving amount (the number of ink droplet drops) indicating the number of ink drops supplied to one pixel in the image of the printing paper P. You may do it. For example, when the reference value of the number of drops of ink droplets dropped on one pixel is 3, and the number of drops is less than or equal to the reference value (3 or less), the outer diameter and temperature control basics of the dot D in the test pattern A immediately before image formation The set temperature of the heater 25 calculated from the data is adopted as it is, and when the number of drops exceeds the reference value (4 or more), the set temperature is increased in proportion to the excess. That is, when the number of drops is 5 and is about 1.7 times the reference value of 3, the set temperature is also about 1.7 times.

  In the embodiment described above, the outer diameter of the dot D read from the test pattern A printed immediately before the image formation, and the temperature control basic data (the outer diameter of the dot D at the basic temperature) acquired in advance from the experiment and stored in the storage means. ) To calculate the set temperature of the heater 25 to control the heating temperature of the printing paper P. However, by keeping the temperature of the heater 25 constant and controlling the speed or time of the printing paper P passing through the heating heater 25, the heating state of the printing paper P is controlled to obtain the same effect. Also good. That is, when the set temperature of the heater 25 should be higher than the basic temperature as judged from the outer diameter of the dot D and the temperature control basic data, the heating heater 25 takes more time by reducing the conveyance speed of the printing paper P. And may be controlled so as to receive more heat from the heater 25.

  The image forming apparatus 1 according to the present embodiment described above uses the inkjet head 12 as the image forming unit. However, when the stencil printing unit is used as the image forming unit, the same effect as that of the present embodiment can be obtained. Can do. Further, since the heating roller 10 using heating means such as the IH heater 25 is used as the heating means for the printing paper P, it is easy to quickly set and change the temperature, and the entire printing paper P is sandwiched. Although efficient heating can be performed, it is also possible to use a heating fan that blows hot air to heat the printing paper P in a non-contact manner.

  As described above, according to each embodiment of the present invention, it is possible to prevent or reduce ink transfer contamination from the image-formed printing paper P to the transport system, and there is a risk of ink adhesion to the transport system. Therefore, there is no need to use an ink adhesion preventing material such as oil, and therefore there is no fear of secondary contamination of the printing paper P due to the ink adhesion preventing material. In addition, it is possible to obtain an image with good resolution that suppresses ink bleeding.

  Further, according to each embodiment of the present invention, the test pattern A is printed using the printing paper P actually used in the printing environment immediately before the actual image formation, and the heating temperature is determined. The temperature control of the paper P can be performed under conditions that are actually adapted. The printing paper P stored in a room other than the room where the image forming apparatus 1 is installed, not the printing paper P stacked on the paper tray 6 of the paper feed unit of the image forming apparatus 1, is brought into the room and the image is displayed. There may be a case where an image is formed by the forming apparatus 1. In this case, printing paper P having a temperature or humidity different from that of the room in which the image forming apparatus 1 is installed is used. For example, such a sheet is actually used to print the test pattern A, and the set temperature of the heater 25 is determined from the outer diameter of the dot D and the temperature control basic data. Therefore, image formation that actually uses the sheet is performed. In this case, the heating temperature of the printing paper P can be set optimally, and as described above, it is difficult for the ink to adhere to the transport system, and the subsequent printing paper P is less likely to be soiled by the transfer of ink. Sure To be obtained.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 2 ... Printing apparatus 4 ... Reading apparatus 10 ... Heating roller as heating means 11 ... Belt conveyor as conveying means in conveying system 12 ... Inkjet as image forming means 13 ... Discharging as conveying means in conveying system Roller 16... Optical system reading unit 30 as reading unit 30... Test pattern printing control unit, determination unit, temperature control unit, and control unit including storage unit for storing temperature control basic data A. Test pattern D ... outer diameter of the dot P ... printing paper T _B ... base temperature d _B ... outer diameter of the dot D in the basic temperature T _n ... set temperature d _n ... dots D obtained by the test pattern print just before printing the test pattern

Claims (5)

Image forming means for forming an image by transferring ink to printing paper; and
Test pattern printing control means for controlling the image forming means to print a test pattern on printing paper;
Determining means for determining the degree of ink bleeding on the printing paper from the test pattern printed on the printing paper;
Storage means for storing temperature control basic data indicating the relationship between the degree of ink bleeding on the printing paper and the paper temperature;
A temperature control means for calculating a set temperature at which the printing paper is heated based on the degree of ink bleeding determined by the determination means from the test pattern and the temperature control basic data of the storage means;
Heating means for heating printing paper to the set temperature calculated by the temperature control means before image formation by the image forming means;
An image forming apparatus comprising: 2. The image forming apparatus according to claim 1, wherein temperature storage basic data prepared in advance for each of a plurality of types of printing paper used for image formation is stored in the storage unit. The test pattern printing control means causes the image forming means to print the test pattern on the printing paper with a predetermined amount of ink so that dots are formed according to the degree of ink bleeding on the printing paper;
The determination means outputs the dot size as a determination result of the degree of ink bleeding on the printing paper,
The storage means stores, as the temperature control basic data, data relating to the relationship between the dot size in the test pattern formed on the printing paper and the paper temperature,
The temperature control unit calculates the set temperature based on the dot size determined from the test pattern by the determination unit and data relating to the relationship between the dot size and the paper temperature stored in the storage unit. The image forming apparatus according to claim 2. 4. The image forming apparatus according to claim 3, wherein the set temperature is corrected based on a printing rate indicating a ratio of an actual image area to an image formable area of the printing paper. 4. The set temperature according to claim 3, wherein when the image forming unit is an inkjet head, the set temperature is corrected based on a driving amount indicating the number of ink drops supplied to one position in an image on a printing paper. Image forming apparatus.

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