JP2010188677A - Image forming apparatus and method for controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the time required for continuous printing when forming an image by attaching ink in series in individual lines arranged along a main scanning direction. <P>SOLUTION: The image forming device calculates ink drying time after the completion of the image forming to a sheet to the completion of drying of the ink the image by subtracting the time after the attachment of the ink to the completion of image forming to the sheet from the time after the attachment of ink in every main scanning lines to the completion of drying of the ink. The image forming device continuously conveys the sheets for forming the image after forming the image to the sheet based on the longest ink drying time among the ink drying times calculated in every scanning lines. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  2. Description of the Related Art Conventional image forming apparatuses such as printers, copiers, facsimile machines, or multi-function machines thereof sequentially transport recording media such as paper (hereinafter referred to as “paper”) in the sub-scanning direction, There is an image forming apparatus in which ink is adhered to a sheet by a recording head moving in the scanning direction, and the adhered ink is dried and fixed on the sheet.

  In this image forming apparatus, when continuous printing is performed, the ink drying time is set so that ink smear does not occur due to contact with other paper while the ink is not dried. The paper is fed accordingly. If this ink drying time is set to be long, the timing for image formation on the next sheet is delayed, and the time required for continuous printing is lengthened. Therefore, it is desired to shorten the ink drying time as much as possible.

  Patent Document 1 is known as a conventional technique for shortening the ink drying time. Japanese Patent Application Laid-Open No. H10-228561 discloses changing the sheet feeding timing of the next page based on the ink usage used on the preceding page.

  Ink drying starts from the point of adhesion to the paper. Therefore, in the case where image formation is performed by sequentially depositing ink for each line along the main scanning direction (hereinafter referred to as “main scanning line”), the ink drying time differs for each main scanning line. However, in the above prior art, paper feeding is not performed in consideration of the ink drying time that differs for each main scanning line. As a result, the time required for continuous printing was long.

  The present invention has been made in view of the above, and it is possible to shorten the time required for continuous printing in the case of forming an image on a sheet by sequentially attaching ink to each line along the main scanning direction. An image forming apparatus and a control method therefor are provided.

  In order to solve the above-described problems and achieve the object, an image forming apparatus according to the present invention includes a conveying unit that conveys a sheet, and a main scanning along a main scanning direction with respect to the sheet conveyed by the conveying unit. An image forming unit that sequentially deposits ink for each line to form an image on the paper, and a time from when the ink is deposited to when the ink is dried for each main scanning line to which the ink is deposited A calculating means for calculating an ink drying time from the completion of image formation on the paper to the drying of the ink by subtracting the time from the ink adhesion to the completion of image formation on the paper. And a sheet on which image formation is continuously performed after image formation on the sheet based on the longest ink drying time calculated for each main scanning line to which the ink is attached. Characterized in that it comprises a control means for conveying to the conveying means.

  According to the present invention, the image is formed on the paper by sequentially adhering the ink to each of the main scanning lines along the main scanning direction on the paper transported by the paper transporting means and the paper transported by the transporting means. A method of controlling an image forming apparatus having image forming means for performing after the ink has adhered from the time from when the ink is adhered to when the ink is dried for each main scanning line to which the ink has been adhered Subtracting the time from the end of image formation to the paper to the end of the image formation to calculate the ink drying time from the end of the image formation on the paper to the time when the ink is dried, and attaching the ink Based on the longest ink drying time calculated for each main scanning line, a sheet on which image formation is continuously performed after image formation on the sheet is conveyed to the conveying unit. A control step that, characterized in that it comprises a.

  According to the present invention, there is an effect that the time required for continuous printing is shortened when ink is sequentially attached to each line along the main scanning direction to form an image on a sheet.

FIG. 1 is a diagram illustrating a configuration of an image forming unit in the image forming apparatus according to the first embodiment. FIG. 2 is a diagram illustrating a sheet and a sheet conveyance direction. FIG. 3 is a block diagram illustrating a functional configuration of the image forming apparatus according to the first embodiment. FIG. 4 is a flowchart illustrating an ink drying time setting process in the image forming apparatus according to the first embodiment. FIG. 5 is a flowchart illustrating processing for forming an image on both sides of a sheet in the image forming apparatus according to the first embodiment. FIG. 6 is a diagram for explaining drawing into the duplex unit in the sheet after the front surface printing. FIG. 7 is a flowchart illustrating an ink drying time setting process in the image forming apparatus according to the third embodiment. FIG. 8 is a diagram illustrating the configuration of the image forming unit in the image forming apparatus according to the fourth embodiment. FIG. 9 is a diagram illustrating a drying waiting time table in the image forming apparatus according to the fourth embodiment.

  Exemplary embodiments of an image forming apparatus and a control method thereof according to the present invention are explained in detail below with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is a diagram illustrating the configuration of the image forming unit 4 in the image forming apparatus 1 according to the first embodiment. As shown in FIG. 1, the image forming apparatus 1 includes an image forming unit 4 having a transport unit 40, a paper feed tray 41, a recording head 42, a paper discharge sensor 43, a paper discharge tray 44, and a duplex unit 45.

  In FIG. 1, a solid line from the paper feed tray 41 to the paper discharge tray 44 via the recording head 42 and the paper discharge sensor 43 indicates a paper conveyance path. Similarly, a dotted line in the duplex unit 45 indicates a sheet conveyance path when the sheet on which the image is formed on the front surface by the recording head 42 is pulled back and an image is formed on the back surface by the recording head 42.

  The transport unit 40 transports the paper along the transport path by a transport roller driven by a driving source such as a motor. Specifically, the transport unit 40 transports paper from the paper feed tray 41 to the recording head 42. Further, the transport unit 40 transports a sheet when an image is formed by the recording head 42 (details will be described later). In addition, the transport unit 40 performs transport for discharging the paper after the image formation to the paper discharge tray 44. When image formation is performed on both sides of the paper, the paper after image formation on the front surface is turned over, so that the paper is conveyed in a direction to be pulled back to the duplex unit 45 (the direction opposite to the conveyance direction during image formation).

  The paper feed tray 41 stores a large number of sheets relating to image formation. The paper stored in the paper feed tray 41 may be recycled paper, high-quality paper, plain paper, postcard, envelope, cardboard, OHP sheet, and the like, and the type is not limited.

  The recording head 42 sequentially forms ink on the paper conveyed by the conveyance unit 40 for each main scanning line along the main scanning direction (for example, orthogonal to the conveyance direction) to form an image on the paper. . Specifically, the recording head 42 moves in the main scanning direction orthogonal to the paper transport direction, and ejects and deposits ink droplets on the transported paper. In the recording head 42, after moving in the main scanning direction and ejecting ink droplets, the paper is transported in the transport direction by a predetermined width (the width of the main scanning line to which ink is attached). As described above, the image forming unit 4 forms an image on the printing surface of the sheet by alternately moving the recording head 42 in the main scanning direction and conveying the sheet of a predetermined width in the conveying direction.

  For example, the recording head 42 includes four full-line ink ejection heads that eject ink droplets for each color of black (K), cyan (C), magenta (M), and yellow (Y) (all (Not shown). Each ink discharge head is mounted on a head holder (not shown) with a nozzle surface on which nozzles for discharging ink droplets are formed facing downward (in a direction perpendicular to the transport path and toward the transported paper). . Therefore, the width of the main scanning line depends on the size of the nozzle surface. The recording head 42 is moved in the main scanning direction by a driving source such as a motor, a driving belt for transmitting the driving force, and a guide member (none of which is shown) arranged along the main scanning direction.

  The recording head 42 described above includes ink discharge heads that discharge ink droplets for each color of yellow, magenta, cyan, and black, but the arrangement and the number of colors of the ink discharge heads are not particularly limited. Further, the ink discharge head and the ink liquid cartridge that supplies the ink liquid to the ink discharge head can be integrated or separated.

  In the recording head 42, an actuator (not shown) for generating a pressure for ejecting ink droplets uses a piezoelectric actuator or an electrothermal transducer that deforms a diaphragm by an electromechanical transducer such as a piezoelectric device. Any of a thermal actuator that generates bubbles due to film boiling in the liquid and an electrostatic actuator that deforms the diaphragm with an electrostatic force generated between the diaphragm and the electrode may be used without any particular limitation.

  The paper discharge sensor 43 is disposed in the vicinity of the paper discharge tray 44 and detects paper that is transported by the transport unit 40 and discharged to the paper discharge tray 44. The paper discharge tray 44 stacks the paper discharged out of the apparatus by the transport unit 40. The duplex unit 45 reverses the front and back of the sheet by conveying the sheet pulled back after the image formation on the front surface along the conveyance path illustrated in the drawing at the time of duplex printing. The paper whose front and back sides are reversed by the duplex unit 45 after the image formation on the front surface is subjected to image formation on the back surface by the recording head 42.

  FIG. 2 is a diagram illustrating a sheet and a sheet conveyance direction. As shown in FIG. 2, the sheet conveyance speed during image formation in the image forming unit 4 is Vy (cm / s), the sheet width (length in the main scanning direction) is X (cm), and the main scanning on the sheet. The positions of the lines are y1, y2, ..., yN (cm). In addition, t1, t2,..., TN corresponding to y1, y2,..., YN are obtained by drying ink droplets attached to the paper obtained based on the amount of ejected ink for each main scanning line. This is the ink drying time required until fixing.

  The paper transported in the direction shown in FIG. 2 is image-formed by the recording head 42 from the upper end (y1) in the transport direction to the lower end (yN). Since the ink drying starts from the time when it adheres to the paper, the ink drying proceeds in order from y1 when the image is formed. Therefore, in the paper on which the image is formed by the image forming unit 4, the degree of ink drying on the printing surface is different for each main scanning line (each position in the sub-scanning direction), and the upper end side and the lower end side in the transport direction. There is a difference in the drying state of the ink. In the present embodiment, the difference in the degree of ink drying that occurs for each main scanning line on the printing surface described above is reflected in the ink drying time of the paper.

For example, it is assumed that the recording head 42 moves in the main scanning direction to eject ink droplets (the width of the main scanning line) is the same as the distance between yn and yn + 1, and the movement width of the recording head 42 in the main scanning direction is as follows. X (cm), and the moving speed is Vx (cm / s). In this case, the ink drying time (T1 (n), n: 1 to N) for each main scanning line is as shown in the following equation (1).
T1 (n) = tn − {((yN−yn) / Vy) + ((N−n) × X / Vx)} (1)

  According to the above formula (1), for each main scanning line, the time from the ink adhering to the ink drying is subtracted from the time after the ink adhering to the end of image formation on the paper, It is possible to calculate the ink drying time from the end of the image formation on the paper to the drying of the ink.

  Since it is necessary that the ink is dried over the entire printing surface, the shortest ink drying time of the paper is the maximum value of T1 (1) to T1 (N). Therefore, as shown in Expression (1), in this embodiment, the ink drying time of the paper can be shortened by the amount subtracted from the ink drying time (tn) obtained based on the ejected ink amount.

  Next, the overall configuration of the image forming apparatus 1 will be described with reference to FIG. FIG. 3 is a block diagram illustrating a functional configuration of the image forming apparatus 1 according to the first embodiment. As shown in FIG. 3, the image forming apparatus 1 includes a control unit 2, a storage unit 3, an image forming unit 4, an operation unit 5, and an I / F unit 6.

  The control unit 2 is a microcontroller or a CPU (Central Processing Unit), and centrally controls the operation of the image forming apparatus 1. Specifically, the control unit 2 develops a program code stored in the storage unit 3 or the like in a work area of a RAM (Random Access Memory) and sequentially executes the program code, thereby transmitting a control signal to each unit of the image forming apparatus 1. Output.

  The storage unit 3 stores program codes executed by the control unit 2, setting information, and the like. Further, the storage unit 3 may provide a work area when the control unit 2 executes the program code. The operation unit 5 is an operation button or a touch panel that receives an operation instruction from the user, and outputs a signal corresponding to the operation instruction to the control unit 2.

  The I / F unit 6 is an interface that communicates with an external device under the control of the control unit 2. Specifically, a USB (Universal Serial Bus), a Centronics interface, an IEEE (Institute of Electrical and Electronics Engineers) 1284, an Ethernet (registered trademark) interface, or the like may be used.

  Next, a process for setting the ink drying time of the paper performed by the control unit 2 will be described with reference to FIG. In FIG. 4, the main scanning line (yn), the ink drying time (T1 (n)) for each main scanning line, and the like are as described above. The initial value of the paper ink drying time (T) is 0, and n at the start of processing is 1.

  As shown in FIG. 4, when the process is started, the control unit 2 acquires the ink discharge amount per unit area in the yn region of the sheet (S1). Specifically, the amount of ink droplets ejected when the recording head 42 is moved in the main scanning direction in the yn region is added, and the added value is divided by the area of the yn region preset as setting information. The ink discharge amount per unit area is calculated by referring to the pixel corresponding to the yn area from the print job data relating to the image formation on the paper and calculating the ink droplet amount according to the pixel value. May be.

  Next, the control unit 2 calculates an ink drying time (tn) required until the ink droplets are dried and fixed in the yn region based on the ink discharge amount acquired in S1 (S2). For example, if the ink discharge amount is large, the ink drying time is long, and if the ink discharge amount is small, the ink drying time is short. In S2, the ink drying time may be calculated according to the paper type. For example, with plain paper and OHP paper, the ink drying time is shorter with plain paper.

  Next, the control unit 2 calculates T1 (n) by the above-described equation (1), and based on the calculated T1 (n), it is determined whether or not it is necessary to extend the ink drying time (T) of the paper. Determine (S3). Specifically, it is determined whether T1 (n)> T is satisfied. If T1 (n)> T is satisfied, T1 (n) is substituted for T in order to adjust T to the longer drying time. (S4).

  Next, the control unit 2 determines whether or not n = N and the processing is completed for all the print areas (y1 to yN) of the sheet (S5). In S5, when the process is not completed, n is incremented and the process returns to S1 (S6), and the process related to the next area (yn + 1 area) is performed. When the processing is completed, T calculated by repeating the processing of S1 to S6, that is, the maximum value of T1 (1) to T1 (N) is set as the ink drying time of the paper (S7).

  Next, processing during duplex printing performed by the image forming apparatus 1 according to the present embodiment under the control of the control unit 2 will be described with reference to FIG. As shown in FIG. 5, when the processing is started, the paper stored in the paper feed tray 41 is fed by the transport unit 40 (S11). Next, image formation on the surface of the fed paper is performed by the image forming unit 4 (S12).

  Next, the control unit 2 performs the processing of S1 to S6 described above to set the ink drying time of the paper (S13), and the conveyance of the paper to the duplex unit 45 is set according to the ink drying time of the paper set in S13. Perform (S14). Specifically, the sheet is conveyed to the duplex unit 45 when the ink drying time has elapsed after the image formation on the front surface so that the ink does not adhere to the conveyance rollers provided in the duplex unit 45 or the like.

  Next, the image forming unit 4 performs image formation on the reverse side of the sheet reversed by the duplex unit 45 (S15), and the sheet after duplex printing is discharged to the discharge tray 44 (S16).

  As described above, in the image forming apparatus 1 according to the present embodiment, from the front side to the back side during double-sided printing based on the ink drying time of the paper that reflects the difference in the degree of ink drying that occurs for each main scanning line on the printing surface. Carry to. Therefore, the image forming apparatus 1 can perform double-sided printing at a higher speed without ink adhering to the surface when being conveyed to the duplex unit 45 after image formation on the surface being adhered to the conveyance roller.

  In this embodiment, the case of duplex printing has been described as an example, but it goes without saying that it may be applied during continuous printing. For example, referring to FIG. 5, image formation is performed on the nth sheet in S12, and the ink drying time of the nth sheet is set in S13. Next, in S14, the (n + 1) th sheet is transported based on the set ink drying time, and in S15, an image is formed on the (n + 1) th sheet. Specifically, in consideration of the time required for image formation on the (n + 1) th sheet, when the ink drying time set after the image formation on the nth sheet has elapsed, the (n + 1) th sheet is discharged to the discharge tray 44. N + 1 sheets are conveyed so as to be stacked. By performing the above-described processing, the ink drying time can be shortened, and higher-speed continuous printing can be performed.

[Second Embodiment]
Next, a second embodiment will be described with reference to FIG. In the following description, the same elements as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different elements are described.

  The second embodiment is limited to printing on both sides of a sheet. When limited to double-sided printing, what is necessary as the paper ink drying time is that when the paper after surface printing is pulled back to reach the double-sided unit 45, the time for the ink to dry is secured. It is. More specifically, when the ink reaches a transport roller that first contacts the surface of the paper (for example, the transport roller of the duplex unit 45), the time for the ink to dry is secured.

  That is, for the paper transported to the duplex unit 45 for backside printing, it is only necessary that the ink is dry at the sub-scanning position of the paper in contact with the transport roller, and the ink is dry over the entire surface. There is no need. Therefore, the ink drying time for each main scanning line may include the time until the main scanning line reaches the duplex unit 45 when the paper is pulled back. In other words, at the time of printing on the back side, the time until each main scanning line by front surface printing reaches the duplex unit 45 is subtracted from the ink drying time corresponding to each main scanning line for each position in the sub-scanning direction of the paper. The ink drying time may be calculated.

  FIG. 6 is a diagram for explaining drawing of the paper after the front surface printing into the duplex unit 45. As shown in FIG. 6, the drawing speed of the sheet into the duplex unit 45 is Vr (cm). Further, it is assumed that the duplex unit 45 is in front of the retracting direction.

In the case of the above-described example, the time from the start of paper drawing to the duplex unit 45 for each main scanning line is (yN−yn) / Vr. Therefore, the ink drying time (T2 (n), n: 1 to N) for each sub-scanning position is as shown in the following equation (2).
T2 (n) = tn− (yN−yn) / Vr (2)

  In double-sided printing, since it is necessary to satisfy the above formula (2) on the entire surface, the maximum value of T2 (1) to T2 (N) is the shortest ink drying time on the surface. In the image forming apparatus 1, by setting the shortest ink drying time on the surface calculated using the equation (2) in S <b> 13 in FIG. 5, higher-speed double-sided printing is possible.

[Third Embodiment]
Next, a third embodiment will be described with reference to FIG. In the following description, the same elements as those in the first and second embodiments are denoted by the same reference numerals, description thereof is omitted, and only different elements are described.

  The third embodiment is a combination of the first and second embodiments described above. The first and second embodiments may be performed independently. However, when executed in combination as shown in the third embodiment, the difference in the degree of ink drying that occurs for each main scanning line is determined as the ink drying time. Can be reflected. Furthermore, the time until each main scanning line reaches the duplex unit 45 when the sheet is pulled back during backside printing can be included in the ink drying time. Therefore, the ink drying time can be further shortened, and higher-speed double-sided printing can be performed.

That is, in the third embodiment, the ink drying time (T2 (n), n: 1 to N) for each main scanning line is as shown in the following equation (3).
T3 (n) = tn− (yN−yn) / Vr − {((yN−yn) / Vy) + ((N−n) × X / Vx)} (3)

  In double-sided printing, since the above formula (3) needs to be satisfied on the entire surface, the maximum value of T3 (1) to T3 (N) is the shortest ink drying time.

  FIG. 7 is a flowchart illustrating a paper ink drying time setting process performed by the control unit 2 in the image forming apparatus 1 according to the third embodiment. As shown in FIG. 7, when the process is started, the control unit 2 acquires the ink discharge amount per unit area in the yn region of the sheet (S21).

  Next, the control unit 2 calculates an ink drying time (tn) required until the ink droplets are dried and fixed in the yn region based on the ink discharge amount acquired in S21 (S22). Next, the control unit 2 calculates the time required for printing in the sub-scanning direction area (yn + 1 to yN) after the yn area (S23). Specifically, in (S23), ((yN−yn) / Vy) + ((N−n) × X / Vx) is calculated.

  Next, the control unit 2 calculates the time required for drawing into the duplex unit 45 for the yn region (S24). Specifically, in S24, (yN−yn) / Vr is calculated.

  Next, the control unit 2 calculates T3 (n) from Equation (3) based on the calculation results of S23 and S24 (S25), and based on the calculated T3 (n), the ink drying time ( It is determined whether or not it is necessary to extend T3) (S26). Specifically, it is determined whether or not T3 (n)> T3 is satisfied. When T3 (n)> T3 is satisfied, T3 (n) is substituted for T3 in order to adjust T3 to the longer drying time. (S27).

  Next, the control unit 2 determines whether or not n = N and the processing is completed for all the print areas (y1 to yN) of the sheet (S28). In S28, when the process is not completed, n is incremented and the process returns to S21 (S29), and the process related to the next area (yn + 1 area) is performed. When the processing is completed, T3 calculated by repeating the processing of S21 to S29, that is, the maximum value of T3 (1) to T3 (N) is set as the ink drying time of the paper (S30).

[Fourth Embodiment]
Next, a fourth embodiment will be described with reference to FIGS. In the following description, the same elements as those in the first to third embodiments are denoted by the same reference numerals, description thereof is omitted, and only different elements are described.

  Regarding the ink drying time, in addition to the ink discharge amount per unit area, the environment (temperature, humidity, etc.) in the vicinity of the paper after image formation also affects. Therefore, in the fourth embodiment, the ink drying time (tn) required until the ink droplets are dried and fixed is calculated in consideration of the environment in the vicinity of the paper after the image formation.

  FIG. 8 is a diagram illustrating the configuration of the image forming unit 4a in the image forming apparatus 1a according to the fourth embodiment. As shown in FIG. 8, the image forming unit 4 a includes a temperature sensor 46 that detects the ambient temperature and a humidity sensor 47 that detects the ambient humidity in the vicinity of the recording head 42. In the image forming unit 4a, the temperature sensor 46 and the humidity sensor 47 detect the environment (temperature and humidity) near the paper after the image is formed.

Regarding the relationship between the temperature / humidity detected by the image forming unit 4a and the ink drying time, generally, the ink drying time is short under high temperature / low humidity. When the ink drying time obtained from the ink discharge amount per unit area is tn at a predetermined reference temperature / humidity, the ink drying time (tn ′) corrected by the temperature / humidity is expressed by the following equation: As in (4).
tn ′ = tn + α × (temperature) + β × (humidity) (4) (α: temperature characteristic value, β: humidity characteristic value)

  In Formula (4), α × (temperature) is a negative value when the temperature is equal to or higher than a predetermined reference temperature, and α × (temperature) is a positive value when the temperature is lower than the predetermined temperature. That is, the ink drying time is shortened at a temperature higher than the reference temperature. In addition, β × (humidity) is a positive value when the humidity is equal to or higher than the reference predetermined humidity, and β × (humidity) is a negative value when the humidity is lower than the predetermined humidity. In other words, the ink drying time is shortened at low humidity below the reference humidity.

  The control unit of the image forming apparatus 1a corrects the value of tn in the equations (1) and (2) by substituting the detection results of the temperature sensor 46 and the humidity sensor 47 into the equation (4). By performing this correction, the image forming apparatus 1a can set the ink drying time according to the environment near the paper.

  However, since the values of α and β depend on each other's environment, ink characteristics, and the like, it may be difficult to express them with mathematical expressions. In this case, as shown in FIG. 9, the ink drying time may be corrected with reference to a three-dimensional correction table of ink discharge amount per unit area, temperature and humidity. Specifically, in the image forming apparatus 1a, the control unit obtains tn ′ by referring to the correction table stored in advance in the storage unit.

  In the above embodiment, the ink drying time (tn) is calculated in consideration of the environment around the paper. However, it goes without saying that the type of paper may be taken into consideration. For example, the ink drying time may be corrected with reference to a four-dimensional correction table of ink discharge amount per unit area, temperature, humidity, and paper type.

  Note that the program code executed by the image forming apparatus of the above-described embodiment is provided by being incorporated in advance in a ROM or the like. The program code executed by the image forming apparatus of the above-described embodiment is an installable or executable file, such as a CD-ROM, a flexible disk (FD), a CD-R, a DVD (Digital Versatile Disk), or the like. You may comprise so that it may record and provide on a computer-readable recording medium. Furthermore, the program code executed by the image forming apparatus of the above-described embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. The program code executed by the image forming apparatus according to the above-described embodiment may be provided or distributed via a network such as the Internet.

  The program code described above may be a printer driver that is executed by an information device such as a PC (Personal Computer) connected to the image forming apparatus via the I / F unit. In other words, the image forming apparatus may be configured to perform control when an image is formed on a sheet by an information device such as a PC executing a program code such as a printer driver. In this case, setting of the ink drying time using the equations (1) to (4) may be performed on the information device side such as a PC.

  In addition, the image forming apparatus in the above embodiment is applicable to any multifunction machine having at least two functions of a copy function, a printer function, a scanner function, and a facsimile function, a printer, a scanner apparatus, a facsimile apparatus, and the like. be able to.

DESCRIPTION OF SYMBOLS 1, 1a Image forming apparatus 2 Control part 3 Memory | storage part 4, 4a Image forming part 5 Operation part 6 I / F part 40 Conveyance part 41 Paper feed tray 42 Recording head 43 Paper discharge sensor 44 Paper discharge tray 45 Both-side unit 46 Temperature sensor 47 Humidity sensor

JP 2004-130565 A

Claims (5)

Conveying means for conveying paper;
Image forming means for sequentially depositing ink for each main scanning line along the main scanning direction on the paper conveyed by the conveying means to form an image on the paper;
For each main scanning line to which the ink has been applied, the time from when the ink has been applied until the ink has dried is subtracted from the time from when the ink has been applied until image formation on the paper is completed. Calculating means for calculating an ink drying time from completion of image formation on the paper to drying of the ink;
Based on the longest ink drying time calculated for each main scanning line to which the ink is attached, a sheet on which image formation is continuously performed after the image is formed on the sheet is conveyed to the conveying unit. Control means for causing
An image forming apparatus comprising: A double-side unit for reversing the front and back of the paper transported to the image forming unit;
The control unit causes the conveyance unit to convey a sheet when image formation is continuously performed on the back surface after forming an image on the front surface of the sheet based on the longest ink drying time. Item 2. The image forming apparatus according to Item 1.   The calculating means calculates the time taken for each main scanning line to which the ink has been attached to reach the double-sided unit when the conveying means conveys the paper to the double-sided unit, and determines the ink drying time corresponding to each main scanning line. The image forming apparatus according to claim 2, further subtracted from time. Detecting means for detecting temperature and humidity in the vicinity of the paper after the image formation;
Correction means for correcting the ink drying time based on the detected temperature and humidity;
The image forming apparatus according to claim 1, further comprising: A conveying unit configured to convey a sheet; and an image forming unit configured to form an image on the sheet by sequentially attaching ink to the sheet conveyed by the conveying unit for each main scanning line along a main scanning direction. An image forming apparatus control method comprising:
For each main scanning line to which the ink has been applied, the time from when the ink has been applied until the ink has dried is subtracted from the time from when the ink has been applied until image formation on the paper is completed. A calculation step of calculating an ink drying time from the end of image formation on the paper to the drying of the ink;
Based on the longest ink drying time calculated for each main scanning line to which the ink is attached, a sheet on which image formation is continuously performed after the image is formed on the sheet is conveyed to the conveying unit. A control step to
A control method for an image forming apparatus.

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