JP2009205062A - Image forming device - Google Patents

Abstract

An object of the present invention is to easily adjust a medium conveyance speed in a medium conveyance unit on the downstream side, to prevent a reduction in image quality, and to reduce the cost of an image forming apparatus. .
An upstream medium conveying unit that conveys a medium for transferring a developer image formed in an image forming unit to a medium, and a downstream side of the upstream medium conveying unit in the medium conveying direction. And a downstream medium conveying unit that conveys the medium, and a medium conveying unit by the downstream medium conveying unit based on a position where a disturbance is formed in an image when a predetermined adjustment pattern is printed. Conveying speed adjustment processing means for adjusting the speed. When the predetermined adjustment pattern is printed, the medium conveyance speed is adjusted by the medium conveyance unit on the downstream side based on the position where the disturbance is formed in the image. Therefore, the medium conveyance speed can be easily adjusted. it can.
[Selection] Figure 1

Description

  The present invention relates to an image forming apparatus.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a printer, a copying machine, a facsimile machine, or a multifunction machine, for example, a printer, a sheet as a medium is fed, a sheet is conveyed, a toner image is formed, and a toner image is fixed. Each unit for discharging the paper on which the sheet is formed is disposed, and the medium is transported at a set transport speed in a medium transport unit constituted by the units.

  In this case, when the sheet is conveyed from the upstream medium conveying unit to the downstream medium conveying unit in the sheet conveying direction, the downstream medium conveying unit uses the medium conveying speed by the upstream medium conveying unit. When the medium conveyance speed is high, the sheet is pulled by the medium conveyance unit on the downstream side, and the sheet cannot be conveyed with high accuracy. As a result, the toner image cannot be transferred to an accurate position, and an image shift, that is, an image shift is formed. Therefore, by setting the medium conveyance speed by the downstream medium conveyance unit lower than the medium conveyance speed by the upstream medium conveyance unit, the sheet is loosened and the sheet is not pulled. .

  However, in recent years, various types of paper having different lengths, thicknesses, and the like may be used according to diversifying user purposes. In this case, the slack becomes larger than that of normal paper. There is. Also, when a paper having a different friction coefficient depending on the surface condition is used, the slack may be larger than that of a normal paper.

  FIG. 2 is a diagram showing a main part of a conventional printer.

  As shown in the drawing, when the downstream medium conveyance unit is configured by the fixing device 18 and the upstream medium conveyance unit is configured by the cyan image forming unit 22C, the slack of the conveyed paper P is large. When the photosensitive drum 52C and the transfer roller 51C are removed from the restraint, the rear end of the paper P jumps up in the direction of the arrow A and contacts the part a on the bottom surface of the image forming unit 22C. If the slack further increases while the paper P is being transported, the direction in which the slack is formed changes to the direction of arrow B, and the paper P is located at the bottom b1 of the image forming unit 22C and the transport path guide b2. Etc.

  As a result, the unfixed toner image formed on the paper P is rubbed by the portions b1 and b2 and the like, and the image is rubbed, the image quality is deteriorated and the conveyance of the paper P becomes unstable. Cause paper jams.

Therefore, a slack sensor (not shown) is provided to detect the slackness of the paper P on the transport path, and the transport speed of the paper P in the fixing unit 18, that is, the fixing speed is adjusted according to the output of the slack sensor. An appropriate amount of slack is formed (for example, see Patent Document 1).
JP-A-7-261484

  However, in the conventional printer, there is no index indicating how much the fixing speed is adjusted, and since the conveyance state of the paper P cannot be visually observed, the operator needs to adjust the fixing speed repeatedly. Occurs. As a result, toner, paper P, and the like as a developer are consumed unnecessarily. If the slack sensor is provided, the cost of the printer becomes high.

  In addition, when the fixing speed is excessively high, the paper P is pulled, image misalignment is formed, and the image quality is degraded.

  The present invention solves the problems of the conventional printer, can easily adjust the medium transport speed in the downstream medium transport section, can prevent the image quality from deteriorating, and can reduce the cost. An object of the present invention is to provide an image forming apparatus capable of reducing the image quality.

  Therefore, in the image forming apparatus of the present invention, an upstream medium conveying unit that conveys a medium for transferring the developer image formed in the image forming unit to the medium, and the upstream side in the medium conveying direction. The downstream side media transport unit that is disposed downstream of the media transport unit, transports the medium, and the position where the disturbance is formed in the image when the predetermined adjustment pattern is printed. Transport speed adjustment processing means for adjusting the transport speed of the medium by the medium transport section.

  According to the present invention, in the image forming apparatus, the upstream side medium transport unit that transports the medium to transfer the developer image formed in the image forming unit to the medium, and the upstream side in the transport direction of the medium The downstream side media transport unit that is disposed downstream of the media transport unit, transports the medium, and the position where the disturbance is formed in the image when the predetermined adjustment pattern is printed. Transport speed adjustment processing means for adjusting the transport speed of the medium by the medium transport section.

  In this case, when the predetermined adjustment pattern is printed, the medium conveyance speed is adjusted by the medium conveyance unit on the downstream side based on the position where the disturbance is formed in the image. Therefore, the medium conveyance speed is easily adjusted. can do. Further, it is possible to prevent the image from being disturbed. Therefore, it is possible to prevent the image quality from deteriorating.

  In addition, since it is not necessary to repeatedly adjust the medium conveyance speed, the developer, the medium, and the like are not consumed unnecessarily. In addition, since it is not necessary to provide a slack sensor, the cost of the image forming apparatus can be reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this case, a printer as an image forming apparatus will be described.

  FIG. 1 is a conceptual diagram of a printer according to a first embodiment of the present invention.

  As shown in the drawing, a paper feed cassette 11 serving as a medium accommodating portion for accommodating paper P as a medium is disposed in the lower part of the printer main body, that is, the apparatus main body, and is adjacent to the front end of the paper feed cassette 11. A paper feed mechanism for feeding the paper P is provided, and the paper feed mechanism includes paper feed rollers 12a and 12b connected to a transport motor (not shown). In the paper feed cassette 11, the paper P is supported by a sheet receive 11a, the sheet receive 11a is pushed up by a spring as a biasing member (not shown), and the front end of the paper P is pressed against the paper feed rollers 12a and 12b. It is done.

  The paper P fed and fed one by one by driving the transport motor and rotating the paper feed rollers 12a and 12b is a transport unit 201 as a first medium transport unit disposed at the top. And transported by the transport unit 201. The transport unit 201 includes a transport roller unit 14 and a transport roller unit 15 disposed downstream of the transport roller unit 14 in the transport direction of the paper P. Each of the transport roller units 14 and 15 serves as a first roller. Pressure rollers 14b and 15b as second rollers that are pressed against the registration rollers 14a and 15a and the registration rollers 14a and 15a and rotated together with the registration rollers 14a and 15a to apply a conveying force to the registration rollers 14a and 15a. .

  Then, the transfer belt 17 as the transport member and the transfer member 17 as the first transfer member is driven by the transport belt motor (not shown) as the belt transporting drive unit, so that the transfer belt 17 is moved to the sheet P. 17 and a plurality of image forming units (ID units) 22Bk, 22Y, 22M, 22C arranged along the conveyance path of the paper P and the transfer unit u1. Each of the image forming units 22Bk, 22Y, 22M, and 22C and the transfer unit u1 constitutes a second medium transport unit. The image forming units 22Bk, 22Y, 22M, and 22C and the transfer unit u1 form an image forming unit, and the image forming unit forms an image of each color of black, yellow, magenta, and cyan.

  For this purpose, each of the image forming units 22Bk, 22Y, 22M, and 22C uniformly distributes the surface of the photosensitive drums 52Bk, 52Y, 52M, and 52C as the image bearing members and the photosensitive drums 52Bk, 52Y, 52M, and 52C. An electrostatic latent image as a latent image formed on the surface of a charging roller (not shown) as a charging device for charging and the photosensitive drums 52Bk, 52Y, 52M, and 52C is developed to form a toner image as a developer image of each color. A developing roller (not shown) as a developer carrying member, a cleaning device (not shown), and the like. Each of the photosensitive drums 52Bk, 52Y, 52M, and 52C is rotated by driving one ID motor (drum motor) as a drive unit for image formation.

  Further, in order to expose the surfaces of the respective photosensitive drums 52Bk, 52Y, 52M, and 52C to form an electrostatic latent image, each LED head 21Bk, 21Y, 21M, and 21C as an exposure device is provided with each image forming unit 22Bk. , 22Y, 22M, and 22C.

  Each of the image forming units 22Bk, 22Y, 22M, and 22C is detachably disposed on the apparatus main body, and for this purpose, an upper cover 23 is disposed on the upper part of the apparatus main body so as to be opened and closed, and the LED heads 21Bk, 21Y, 21M, and 21C are held by the upper cover 23.

  The transfer unit u1 is connected to the transport belt motor, and is driven by a drive roller 27, an idle roller 28, the transfer belt 17 stretched by the drive roller 27 and the idle roller 28, and the transfer belt 17 between the transfer unit u1. Transfer rollers 51Bk, 51Y, 51M, and 51C are provided as second transfer members disposed so as to face the photosensitive drums 52Bk, 52Y, 52M, and 52C. The idle roller 28 is rotated with the drive roller 27 so as to apply tension so that the transfer belt 17 does not loosen.

  The transfer rollers 51Bk, 51Y, 51M, and 51C transfer the toner images of the respective colors formed by the photosensitive drums 52Bk, 52Y, 52M, and 52C in the image forming units 22Bk, 22Y, 22M, and 22C to the paper P. Then, a color toner image is formed. Incidentally, between the image forming units 22Bk, 22Y, 22M, 22C and the transfer unit u1, that is, between the photosensitive drums 52Bk, 52Y, 52M, 52C and the transfer rollers 51Bk, 51Y, 51M, 51C. In addition, a transfer portion for each color is formed.

  Subsequently, the paper P is sent to a fixing device 18 as a third medium conveyance unit and as a fixing device (fixing unit), and the color toner image is fixed on the paper P in the fixing device 18. A color image is formed. The paper P sent from the fixing device 18 is transported by the transport roller unit 19 and then discharged from the apparatus main body by the discharge roller unit 20. The transport roller unit 19 and the discharge roller unit 20 are both pressed against the transport rollers 19a and 20a as the first rollers and the transport rollers 19a and 20a, and are rotated together with the transport rollers 19a and 20a. Discharge rollers 19b and 20b are provided as second rollers for applying a conveying force. Reference numeral 31 denotes a discharge unit for transporting the paper P sent from the fixing device 18, discharging it to the upper cover 23, and stacking it. The discharge unit 31 constitutes a fourth medium transport unit. In this case, the first medium transport unit is more upstream than the second medium transport unit, the second medium transport unit is more upstream than the third medium transport unit, and the third medium transport unit is more upstream than the fourth medium transport unit. The fourth medium transport section is disposed from the third medium transport section, the third medium transport section from the second medium transport section, and the second medium transport section from the first medium transport section. It is arranged.

  The fixing device 18 is pressed by the fixing roller 25 as a fixing member that is rotated by a fixing motor (not shown) as a fixing driving unit, and is pressed against the fixing roller 25 to be rotated along with the fixing roller 25. A pressure roller 26 is provided as a pressure member for applying a conveying force to the toner, and toner as a developer is formed on the paper P by heat from a heater 25a as a heating body provided in the fixing roller 25. Melted on top.

  The fixing roller 25 is formed by coating a core metal such as iron or aluminum with an elastic body such as a silicone rubber having a thickness of 1.5 [mm]. By covering the tube made of resin, toner adhesion is prevented. The pressure roller 26 is formed by coating a core metal such as iron or aluminum with an elastic body such as silicone rubber, and the surface of the elastic body is coated with a fluorine-based resin, thereby conveying the paper P. When a paper jam occurs, the toner of the toner image that has not been fixed is prevented from being offset and adhering to the fixing roller 25. Since the fixing roller 25 and the pressure roller 26 are provided with an elastic body, not only can the heat capacity be increased, but also a sufficient nip width (pressing width) can be secured.

  The transport roller units 14, 15, 19, the photosensitive drums 52Bk, 52Y, 52M, 52C, the fixing roller 25, the pressure roller 26, the discharge roller unit 20, and the like are composed of a rotating body for transporting the paper P. The transfer belt 17 functions as a transport element including a moving body for transporting the paper P.

  Further, an operation / display unit is formed on the front surface of the apparatus main body, and an operation unit 102 for operating the printer and a display unit 101 for displaying the status of the printer are disposed on the operation / display unit.

  Next, the display unit 101 and the operation unit 102 will be described.

  FIG. 3 is a diagram showing a display unit and an operation unit in the first embodiment of the present invention.

  As shown in the figure, the display unit 101 includes a liquid crystal display (LCD) m1 as a display member for displaying the printer status, setting contents, and the like, and the operation unit 102 displays the printer status. LEDs m2 and m3 as display elements and keys k1 to k6 as operation elements for giving instructions from the operator to the printer. In this embodiment, the display unit 101 and the operation unit 102 are arranged independently of each other, but the display unit can also function as an operation unit. In that case, the display unit is formed by a touch panel.

  Next, a printer control device will be described.

  FIG. 4 is a first block diagram showing a printer control apparatus according to the first embodiment of the present invention, and FIG. 5 is a second block diagram showing a printer control apparatus according to the first embodiment of the present invention. is there. Note that the control block diagrams shown in FIGS. 4 and 5 show one print control apparatus in a divided manner.

  In the figure, reference numeral 61 denotes a print control unit as a control unit having a microprocessor, ROM, RAM, input / output port, timer, etc. (not shown). The print control unit 61 is a host device (not shown) such as a host computer. Based on the print data and the control command received via the interface control unit 62, the overall printing operation of the printer is controlled, a color image is formed, and printing is performed. The interface control unit 62 transmits information representing the printer status to the host computer, analyzes the control command received from the host computer, and records the received print data in the reception memory 63 for each color. To do. The print data input from the host computer via the interface control unit 62 is edited by the print control unit 61 and is sent to the LED heads 21Bk, 21Y, 21M, and 21C as image data for each color as an image data editing memory. 64.

  Reference numeral 101 denotes a display unit, 102 denotes an operation unit, 66 denotes a plurality of sensors that detect the conveyance position of the paper P, a sensor that detects the temperature and humidity of each unit in the printer, and a sensor that detects the density of a color image. The sensor output of each sensor of the sensor unit 66 is sent to the print control unit 61.

  The print control unit 61 includes a charging voltage control unit 67, a head control unit 69, a development voltage control unit 71, a transfer voltage control unit 73, an ID motor control unit 75, a conveyance motor control unit 77, a conveyance belt motor control unit 79, and A fixing control unit 81 is connected.

  The charging voltage control unit 67 receives an instruction from the printing control unit 61 and applies a voltage to the charging rollers 40Bk, 40Y, 40M, and 40C, and the photosensitive drums 52Bk (FIG. 1), 52Y, 52M, and 52C. Control to charge the surface. The charging voltage control unit 67 includes charging voltage control units 68Bk, 68Y, 68M, and 68C for controlling each color, and controls the charging voltage applied to the charging rollers 40Bk, 40Y, 40M, and 40C. To do.

  The head controller 69 receives an instruction from the print controller 61, receives the image data of each color recorded in the image data editing memory 64, and receives the image data of each color as the LED heads 21Bk, 21Y, 21M. , 21C, the LED elements of the LED array (not shown) are selectively made to emit light, and the surface of the photosensitive drums 52Bk, 52Y, 52M, 52C is controlled to be exposed to light, and the photosensitive drums 52Bk, An electrostatic latent image is formed on 52Y, 52M, and 52C. The head controller 69 includes head controllers 70Bk, 70Y, 70M, and 70C for controlling each color, and transmits image data to the LED heads 21Bk, 21Y, 21M, and 21C at a predetermined timing. Control for.

  The developing voltage controller 71 receives an instruction from the printing controller 61, applies a developing voltage to the developing rollers 41Bk, 41Y, 41M, and 41C, and applies the developing voltage to the photosensitive drums 52Bk, 52Y, 52M, and 52C. Control is performed to form a toner image by attaching toner to the formed electrostatic latent image. The development voltage control unit 71 includes development voltage control units 72Bk, 72Y, 72M, and 72C for controlling each color, and controls the development voltages applied to the development rollers 41Bk, 41Y, 41M, and 41C. To do.

  The transfer voltage controller 73 receives an instruction from the print controller 61, applies a transfer voltage to each of the transfer rollers 51Bk, 51Y, 51M, and 51C, and forms it on the photosensitive drums 52Bk, 52Y, 52M, and 52C. Control for transferring the toner image to the paper P is performed. The transfer voltage control unit 73 includes transfer voltage control units 74Bk, 74Y, 74M, and 74C for controlling each color and for sequentially transferring the toner images of the respective colors onto the paper P. The transfer voltage applied to 51Bk, 51Y, 51M, and 51C is controlled.

  The ID motor control unit 75 receives an instruction from the print control unit 61, and the photosensitive drums 52Bk, 52Y, 52M, 52C, the charging rollers 40Bk, 40Y, 40M, 40C, and the developing rollers 41Bk, 41Y, 41M. , 41C is driven to drive an ID motor 76 as an image forming and conveying drive unit.

  Further, the transport motor control unit 77 feeds the paper P and drives a transport motor 78 as a transport drive unit for transporting the paper P to the image forming units 22Bk, 22Y, 22M, and 22C, whereby the registration motor is controlled. The conveyance belt motor control unit 79 rotates the rollers 14a and 15a, and the conveyance belt motor control unit 79 conveys the sheet P to the fixing unit 18 in the image forming units 22Bk, 22Y, 22M, and 22C. To drive the transfer belt 17.

  The fixing control unit 81 receives an instruction from the printing control unit 61, applies a fixing voltage to the heater 25 a of the fixing device 18, and performs control for fixing the toner image transferred onto the paper P. The fixing controller 81 controls the heater 25a to be turned on / off by the heater controller 81b based on the temperature detected by the fixing thermistor 30, and when the fixing device 18 reaches a predetermined set temperature, The controller 81a drives a fixing motor 82 as a fixing driving unit to rotate the fixing roller 25 and the pressure roller 26.

  Then, the print control unit 61 receives print data and control commands transmitted from the host device via the interface control unit 62. Subsequently, when a printing instruction is received from the upper apparatus, first, the conveyance speed Vb of the paper P in the image forming unit and the fixing speed Vf representing the conveyance speed of the paper P in the fixing device 18 are determined based on the received print information. . The fixing speed Vf is set to a speed corresponding to a condition for sufficiently melting the toner on the paper P and sufficiently fixing the toner image. For this purpose, the image forming unit 22C, the fixing device 18, and the like. The conveyance speed Vb and the fixing speed Vf are set according to the size, thickness, type, and the like of the paper P included in the print information so that slack is formed between the paper P and the printing temperature together with the fixing temperature Tf. It is recorded in the storage unit 61 a of the control unit 61.

In the present embodiment, an item of custom media is set in the storage unit 61a so that good printing can be performed on the long paper P. The conveyance speed Vb, the fixing speed Vf, and the fixing temperature Tf are set and recorded for the paper P. For example, when a sheet P having a width of 210 [mm], a length of 1200 [mm], and a weighing of 128 [g / m ² ], which is referred to as an A4 size long paper, is used, the conveyance speed Vb is The fixing speed Vf is set to 119.7 [mm / sec], which is 0.25% lower than the conveying speed Vb, and the fixing temperature Tf is set to 170 [° C.]. It should be noted that by operating the operation unit 102, the fixing speed Vf can be freely changed to be adjusted and custom-set. Reference numeral 61b denotes a calculation unit of the print control unit 61.

  Next, a method for custom setting the fixing speed Vf will be described.

  FIG. 6 is a diagram showing a display unit and an operation unit when the fixing speed is custom-set according to the first embodiment of the present invention.

  When changing the fixing speed Vf, first, the display unit 101 displays items for changing the fixing speed Vf by operating the keys k1 to k6. In this case, as will be described later, the fixing speed Vf can be changed in increments of a preset width by pressing the keys k3 and k4. In the present embodiment, the change width of the fixing speed Vf is set to +30, and the width of each step is set to 0.1 [%].

That is, when the correction value representing the change amount (number of steps) of the fixing speed Vf in the liquid crystal display m1 is γ and the fixing speed after the change is Vf ′, the fixing speed Vf ′ is
Vf ′ = (1 + 0.001 × γ) × Vf
become.

As described above, in the present embodiment, the fixing speed Vf is 0.25% lower than the transport speed Vb,
Vf = 0.9975 × Vb
Therefore, the fixing speed Vf ′ is
Vf ′ = (1 + 0.001 × γ) × (0.9975 × Vb)
become. The initial value of the correction value γ is set to zero (0).

  By the way, in the present embodiment, a predetermined adjustment pattern is printed, and the fixing temperature Vf can be adjusted based on the printing result. Reference numeral 102 denotes an operation unit, and m2 and m3 denote LEDs.

  Next, the adjustment pattern will be described.

  FIG. 7 is a diagram showing an example of an adjustment pattern in the first embodiment of the present invention, FIG. 8 is a detailed view of the latter half of the adjustment pattern in the first embodiment of the present invention, and FIG. It is a figure which shows the principal part of the adjustment pattern in 1 embodiment.

  As shown in the figure, the adjustment pattern connects the left and right edges of the paper P on the paper P, and in a predetermined range in the length direction, from the rear end to the front end of the paper P in the present embodiment. In the present embodiment, it is constituted by a plurality of ruled lines formed at equal intervals and in parallel. The adjustment pattern is divided into a plurality of areas in the width direction of the paper P, in this embodiment, five areas, that is, ruled line patterns PL1, PL2, PC, PR2, and PR1. The interval ΔLa between the ruled lines is set to 10 [mm], but can be changed as necessary.

  Further, the ruled line patterns PL1 and PR1 are each provided with a scale serving as an index for adjusting the fixing speed Vf from the rear end to the front end of the paper P. Then, the numerical value of +1 scale and the numerical value of a scale of multiples of +5 are surrounded by a frame fr so that the operator can easily see, and other numerical values are set as a vernier without being surrounded. Note that black toner is used for printing the ruled lines and scales.

  By the way, as described above, a slack is formed on the paper P between the image forming unit 22C (FIG. 1) and the fixing device 18. However, when the slack increases, the paper P becomes a photosensitive member. When the rear end is bounced off from the restraint by the drum 52C and the transfer roller 51C, the rear end is brought into contact with a part a (see FIG. 2) on the bottom surface of the image forming unit 22C, and unfixed toner near the rear end of the sheet P. The image is rubbed by the part a, and the image is rubbed. If the slack further increases, the slack moves upward and comes into contact with the part b1 on the bottom surface of the image forming unit 22C, the guide b2 on the conveyance path, and the like. As a result, the unfixed toner image is rubbed by the part b1, the guide b2, and the like, and the image is rubbed. Further, as the slack becomes larger, the rub is formed on the front end side of the paper P. Note that the image is disturbed by the rubbing of the image. Therefore, the numerical value of the scale in the adjustment pattern is the smallest at the rear end of the paper P and is increased toward the front.

  In contrast, when the paper P is not slackened and is pulled by the fixing device 18, the toner images of the respective colors formed by the image forming units 22Bk, 22Y, 22M, and 22C are transferred to the paper P. Misalignment and image misalignment are formed. The image is disturbed due to the image shift.

  Therefore, the ruled line patterns PL2 and PR2 are formed of black toner and have a rectangular frame shape pattern Kp having a rectangular shape and a rectangular shape formed of cyan toner with the periphery overlapped with the pattern Kp. It consists of a strip-like pattern Cp having In the pattern Kp, there is formed a pattern Np having a rectangular shape and made of a base (white) of the paper P.

The amount ΔLb of the overlap between the pattern Kp and the pattern Cp on the four sides is
ΔLb = 200 [μm]
To be.

  When the pattern Kp and the pattern Cp are printed in either direction, for example, more than 200 [μm], the pattern Np becomes white and appears on the ruled line patterns PL2 and PR2. Note that the amount ΔLb can be changed as necessary.

  In this case, the pattern Cp is formed only with cyan toner. This is because, when the fixing speed Vf is changed, the image forming unit 22C is disposed at the farthest position in the transport direction of the paper P with respect to the image forming unit 22Bk, so that the image misalignment is the most in the pattern Cp. This is because it appears remarkably.

  Accordingly, the toner images of the respective colors cannot be transferred to accurate positions, and when image misalignment is formed, the operator can easily confirm the image misalignment by visually observing the ruled line patterns PL2 and PR2. Can do.

  In the present embodiment, the pattern Kp is formed by the image forming unit 22Bk and the pattern Cp is formed by the image forming unit 22C. However, it is possible to confirm that image misalignment is formed. Two patterns can be formed by any two of the image forming units 22Bk, 22Y, 22M, and 22C.

  In the present embodiment, the image forming units 22Bk, 22Y, 22M, and 22C are arranged in this order from the upstream side to the downstream side in the transport direction of the paper P, but image misalignment is formed. The image forming units can be arranged in any order as long as they can be sufficiently detected.

  In the ruled line pattern PC, the entire area between the ruled lines is printed with black toner so that when an image is rubbed as the paper P is conveyed, it can be visually confirmed. The ratio of the area of the ruled line pattern PC to the area of the paper P is set to 10 [%].

  Next, a method for printing the adjustment pattern on the paper P and changing the fixing speed Vf based on the printing result, and the operation of the print control unit 61 (FIGS. 4 and 5) will be described.

  FIG. 10 is a flowchart showing the operation of the print control unit in the first embodiment of the present invention, FIG. 11 is a first diagram showing the adjustment pattern printing method in the first embodiment of the present invention, and FIG. FIG. 13 is a second diagram illustrating the adjustment pattern printing method according to the first embodiment of the present invention, FIG. 13 is a third diagram illustrating the adjustment pattern printing method according to the first embodiment of the present invention, and FIG. FIG. 15 is a fourth diagram illustrating the adjustment pattern printing method according to the first embodiment of the present invention. FIG. 15 is a fifth diagram illustrating the adjustment pattern printing method according to the first embodiment of the present invention. FIG. 6 shows a method for printing an adjustment pattern in the first embodiment of the present invention, and FIG. 17 shows a print result of the adjustment pattern when rubbing is detected in the first embodiment of the present invention. FIG. 18 shows the first of the present invention. FIG. 19 is a first diagram showing a fixing speed adjustment method when rubbing is detected in the embodiment, and FIG. 19 is a second diagram showing a fixing speed adjusting method when rubbing is detected in the first embodiment of the present invention. FIG. 20 is a third diagram showing a fixing speed adjusting method when rubbing is detected in the first embodiment of the present invention. FIG. 21 is a diagram showing rubbing in the first embodiment of the present invention. FIG. 22 is a fifth diagram showing a fixing speed adjusting method when rubbing is detected in the first embodiment of the present invention, and FIG. FIG. 24 shows a method for adjusting the fixing speed when rubbing is detected in the first embodiment of the invention. FIG. 24 is a diagram showing adjustment of the fixing speed when rubbing is detected in the first embodiment of the present invention. FIG. 25 shows the method according to the first embodiment of the present invention. FIG. 26 shows a fixing speed adjusting method when rubbing is detected in the state, and FIG. 26 is a ninth diagram showing fixing speed adjusting method when rubbing is detected in the first embodiment of the present invention. FIG. 27 is a tenth view showing a fixing speed adjustment method when rubbing is detected in the first embodiment of the present invention. FIG. 28 is a diagram of rubbing detected in the first embodiment of the present invention. FIG. 29 shows a method for adjusting the fixing speed, FIG. 29 shows a method for adjusting the fixing speed when rubbing is detected in the first embodiment of the present invention, and FIG. 30 shows a method for adjusting the fixing speed. FIG. 31 is a diagram showing a printing result of an adjustment pattern when image misalignment is detected in the first embodiment, and FIG. 31 shows a printing result of the adjustment pattern when image misalignment is detected in the first embodiment of the present invention. Detailed view, FIG. 32 shows the first embodiment of the present invention. FIG. 33 is a first diagram illustrating a fixing speed adjusting method when image misalignment is detected in the form, and FIG. 33 is a second diagram illustrating a fixing speed adjusting method when image misalignment is detected in the first embodiment of the present invention. FIG. 34 is a third diagram showing a fixing speed adjusting method when image shift is detected in the first embodiment of the present invention.

  First, in order to make a custom setting in an online state, the operator sets the printing conditions when the size, thickness, type, etc. are general, such as A4 size paper P, for example, in the item of the custom media. Set to Custom 1. Further, the operator sets the fixing speed Vf and sets the initial value of the correction value γ to zero.

  Next, printing is performed on the paper P. If no rubbing or image misalignment is formed on the image, there is no problem in the print result, and there is no need to change the setting of the item custom 1, so printing is terminated.

  On the other hand, if the image is rubbed or misaligned, an adjustment pattern for adjusting the fixing speed Vf is printed. First, as shown in FIG. 11, when the key k5 is pressed while “online” is displayed on the liquid crystal display m1 of the display unit 101, “offline” is displayed on the liquid crystal display m1 as shown in FIG. Is displayed. Here, when the key k1 is pressed, as shown in FIG. 13, a menu screen for performing various settings is formed on the liquid crystal display m1, and “menu commuting” indicating that menu items can be set. Is displayed.

  Subsequently, when the key k3 or the key k4 is pressed several times, as shown in FIG. 14, a “color menu” that is a selection item for printing the adjustment pattern is displayed on the liquid crystal display m1.

  Next, when the key k1 is pressed, as shown in FIG. 15, “color menu noisy”, which is a selection item one level below the “color menu” for printing the adjustment pattern on the liquid crystal display m1, is displayed. Is displayed. In this case, “Color Menu Noisy” includes settings related to image quality such as density adjustment in addition to rubbing and image shift.

  Subsequently, when the key k3 or the key k4 is pressed several times, as shown in FIG. 16, the selection item at the next lower level in the “color menu noisy” for printing the adjustment pattern on the liquid crystal display m1. A certain “Color Menu Adjust” is displayed. In this case, “color menu adjustment p” is a display for executing printing of the adjustment pattern.

  Here, when the key k1 is pressed, the adjustment pattern print processing means (not shown) of the calculation unit 61b of the print control unit 61 (FIGS. 4 and 5) performs the adjustment pattern printing process and prints the adjustment pattern on the paper P.

  At this time, it is possible to visually determine whether rubbing or image shift is formed in the adjustment pattern.

  For example, in the printing result shown in FIG. 17, the rubbing S is formed obliquely in the latter half of the adjustment pattern. The shape of the rubbing S changes depending on the balance of the slackness of the left and right sides of the paper P, the rubbing position, and the like. In addition, when the conveyance force of the paper P is equal on the left and right and the presser at the center is weak, linear rubbing is formed, but generally it is difficult to equalize the conveyance force of the paper P on the left and right. The rubbing often bends in the direction of stronger tensile force and becomes S-shaped.

In this case, since the rubbing S is formed obliquely from the position “+5” of the scale to the rear end of the paper P, the position where the rubbing S is formed, that is, the rubbing position α is
α = + 5
Thus, it can be seen that it is preferable to set the correction value γ for changing the fixing speed Vf to +5.

  Next, a method for adjusting the fixing speed Vf will be described.

  First, as shown in FIG. 18, when the key k5 is pressed while “online” is displayed on the liquid crystal display m1, “offline” is displayed on the liquid crystal display m1, as shown in FIG. Here, when the key k1 is pressed, as shown in FIG. 20, a menu screen is formed on the liquid crystal display m1, and “menu bar” indicating that a menu item can be set is displayed.

  Subsequently, when the key k3 or the key k4 is pressed several times, as shown in FIG. 21, the “Adjust menu” which is a selection item for changing the fixing speed Vf is displayed on the liquid crystal display m1.

  Next, when the key k1 is pressed, as shown in FIG. 22, “adjustment” which is a selection item in the lower hierarchy in the “adjustment menu” for changing the fixing speed Vf is displayed on the liquid crystal display m1. Menu Belt Belt "is displayed. In this case, the “Adjust Menu Belt Belt” includes settings related to the printing speed.

  Subsequently, when the key k3 or the key k4 is pressed several times, as shown in FIG. 23, “Adjust menu menu for changing the fixing speed Vf” is displayed on the liquid crystal display m1. In this case, “Adjust Menu Menu Take” is a display for changing the fixing speed Vf.

  Therefore, when the key k1 is pressed, as shown in FIG. 24, “changeable paper” for setting the type of each paper P such as plain paper or thick paper is displayed on the liquid crystal display m1 when the fixing speed Vf is changed. Is displayed.

  Next, when the key k3 or the key k4 is pressed several times, as shown in FIG. 25, “Teaching Custom 1” for changing the fixing speed Vf of the item custom 1 is displayed on the liquid crystal display m1.

  Subsequently, when the key k1 is pressed, as shown in FIG. 26, “Teaching 0” indicating the initial value for changing the fixing speed Vf is displayed on the liquid crystal display m1. In the liquid crystal display m1, “*” indicating that the fixing speed Vf is set to “0” in the initial state indicates that the fixing speed Vf of the item custom 1 is changed to the left of “0”. “K 1” is displayed to the right of “0”.

  Next, when the key k3 or the key k4 is pressed several times, as shown in FIG. 27, “Teach Takes +5” which is a selection item for changing the fixing speed Vf is displayed on the liquid crystal display m1. Here, when the key k1 is pressed and held down, the change of the fixing speed Vf is determined, and as shown in FIG. 28, “*” indicating that the change has been determined is displayed to the left of “+5”.

In this way, when the correction value γ is set to +5 and determined, the fixing speed adjustment processing unit (not shown) as the conveyance speed adjustment processing unit of the calculation unit 61b performs the fixing speed adjustment processing as the conveyance speed adjustment processing. And the fixing speed Vf is changed based on the correction value γ. In this case, the changed fixing speed Vf ′ is
Vf ′ = (1 + 0.001 × 5) × Vf
= 1.005 x Vf
= 1.005 x 0.9975 x Vb
≒ 1.0025 x Vb
become.

  A recording processing unit (not shown) of the calculation unit 61b performs a recording process, and records the changed fixing speed Vf 'and the correction value γ in the storage unit 61a.

  Next, when the key k2 is pressed, as shown in FIG. 29, “Teaching Custom 1” is displayed on the liquid crystal display m1, and “*” indicating that the change has been decided is “Custom 1”. Displayed on the left. In this way, the operator can know that the fixing speed Vf has been changed.

  Subsequently, the key k2 is pressed and held down to display “online” on the liquid crystal display m1, as shown in FIG. 11, and then the adjustment pattern is printed again in the procedure shown in FIGS. It is visually determined whether or not rubbing S is formed on the pattern.

  As described above, when rubbing S is formed on the adjustment pattern, the fixing speed Vf is changed, the difference between the changed fixing speed Vf ′ and the transport speed Vb is reduced, or the fixing speed Vf ′ is changed to the transport speed Vb. By doing so, it is possible to suppress the occurrence of large slack, so that it is possible to prevent the image from being rubbed.

  By the way, when the rubbing S is formed at the position “+5”, if the correction value γ is set to at least +5 or more, the slackness of the paper P can be reduced. Therefore, even if the conveying force of the paper P changes, the rubbing S can be prevented from being formed accordingly, and the margin of the correction value γ can be increased in the rubbing S.

  However, when the correction value γ is excessively increased, the fixing speed Vf ′ after the change is increased by that amount, and when the cyan toner image is transferred in the image forming unit 22C (FIG. 1), the sheet is fed by the fixing device 18. P may be pulled.

  As a result, when the adjustment pattern is printed, no rubbing S is formed on the adjustment pattern, but between the toner image transferred by the image forming units 22Bk, 22Y, and 22M and the toner image transferred by the image forming unit 22C. Image misalignment is formed.

For example, when the correction value γ is +13, the fixing speed Vf ′ is
Vf ′ = (1 + 0.001 × 13) × Vf
= 1.013 × Vf
= 1.013 × 0.9975 × Vb
≒ 1.0105 × Vb
Thus, the sheet P is pulled by the fixing unit 18 when the cyan toner image is transferred in the image forming unit 22C. As a result, for example, in the printing result shown in FIG. 30, an image shift Z is formed in the ruled line patterns PL2 and PR2, and as shown in FIG. 31, the pattern Np is white for the length ΔLbt. appear. This is because the transport speed Vb when the toner image of the pattern Cp is transferred in the image forming unit 22C is higher than the transport speed Vb when the toner image of the pattern Kp is transferred in the image forming unit 22Bk. This is because the toner image transfer timing in the image forming unit 22C is apparently delayed.

  Therefore, in the present embodiment, the image shift Z is prevented from occurring by changing the fixing speed Vf.

In this case, the image misalignment Z is formed from the position “+2” of the scale in the adjustment pattern to the rear end of the adjustment pattern, and therefore the position where the image misalignment Z is formed, that is, the image misalignment position β is
β = + 2
In other words, it is preferable to subtract the correction value γ by +2.

  Therefore, as shown in FIG. 32, the key k1 is pressed in the state where the “adjustment menu for changing the fixing speed Vf” is displayed on the liquid crystal display m1, and then the key k3 or the key k4. When the button is pressed several times, as shown in FIG. 33, the item custom 1 “Teaching Speed +13” for changing the fixing speed Vf is displayed on the liquid crystal display m1. Therefore, when the key k1 is pressed, the change of the fixing speed Vf is determined, and “*” indicating that the change has been determined is displayed to the left of “+13”.

  Next, when the key k3 is pressed twice, as shown in FIG. 34, “Teaching + 1 + 1” for changing the fixing speed Vf is displayed on the liquid crystal display m1.

When the key k1 is pressed for a long time, the correction value γ is set to +11 and determined. Subsequently, the fixing speed adjustment processing unit changes the fixing speed Vf based on the correction value γ. In this case, the fixing speed Vf ′ after the change is
Vf ′ = (1 + 0.001 × 11) × Vf
= 1.011 × Vf
= 1.011 × 0.9975 × Vb
≒ 1.0085 x Vb
become.

  The recording processing unit records the changed fixing speed Vf ′ and the correction value γ in the storage unit 61a.

  Subsequently, the key k2 is pressed and held down to display “online” on the liquid crystal display m1, as shown in FIG. 11, and then the adjustment pattern is printed again in the procedure shown in FIGS. It is visually determined whether or not an image shift Z is formed in the pattern. On the other hand, if no image misalignment Z is formed in the adjustment pattern, the process ends.

  As described above, in the present embodiment, when rubbing S is formed in the adjustment pattern, the fixing speed Vf is corrected with the correction value γ corresponding to the rubbing position α, and is increased. The slackness of P can be reduced. Therefore, it is possible to prevent the rubbing S from being formed on the image, and it is possible to prevent the image quality from deteriorating.

  In addition, when the image misalignment Z is formed in the adjustment pattern, the fixing speed Vf is corrected by the correction value γ corresponding to the image misalignment position β, and the slackness of the paper P is increased. Can do. Accordingly, it is possible to prevent the image shift Z from being formed on the image, and thus it is possible to prevent the image quality from deteriorating.

  Then, the operator determines whether or not the rubbing S and the image misalignment Z are formed in the adjustment pattern. When the rubbing S and the image misalignment Z are formed, the operator only needs to check the rubbing position α and the image misalignment position β. The fixing speed Vf can be easily changed and adjusted. Further, since it is not necessary to repeatedly perform printing, toner, paper P, and the like are not consumed unnecessarily. Since it is not necessary to provide a slack sensor, the cost of the printer can be reduced.

  In addition, since it is possible to simultaneously determine whether or not the rubbing S and the image shift Z are formed in the adjustment pattern, it is possible to simplify the operation of changing the fixing speed Vf.

  Furthermore, by setting the fixing speed Vf higher than the correction value γ at which the rubbing S is not formed, the margin of the fixing speed Vf at which the image misalignment Z is not formed can be confirmed. For example, the correction value γ for the fixing speed Vf When + is set to +8, a margin of ± 3 can be set for the rubbing S and image shift Z with the correction value γ. That is, since a margin of ± 0.3 [%] can be set at the fixing speed Vf, even if there is a change in the environment around the printer or a change with time of the conveyance roller or the like, the rubbing S and the image misalignment Z Can be prevented.

Next, a flowchart will be described.
Step S1: The correction value γ is set to zero.
Step S2 Printing is performed.
Step S3: It is determined whether the rubbing S or the image shift Z is formed. When the rubbing S or the image shift Z is formed, the process proceeds to step S4, and when it is not formed, the process is terminated.
Step S4 Print the adjustment pattern.
Step S5: It is determined whether or not the rubbing S is formed. If rubbing S is formed, the process proceeds to step S6, and if not formed, the process proceeds to step S8.
Step S6 Check the rubbing position α.
Step S7: The value α is added to the correction value γ.
Step S8: It is determined whether an image shift Z is formed. When the image shift Z is formed, the process proceeds to step S9, and when it is not formed, the process ends.
Step S9: Check the image shift position β.
Step S10 The value β is subtracted from the correction value γ.
Step S11: The fixing speed Vf is changed.
Step S12: The changed fixing speed Vf ′ and correction value γ are recorded, and the process returns to step S4.

  By the way, in the first embodiment, even when printing is performed on the same paper P, if the amount of toner of the toner image transferred to the paper P increases, the friction coefficient of the paper P decreases accordingly. Thus, when the paper P is transported, a minute slip due to the toner image is likely to occur, and the transport force of the paper P is reduced. However, when the amount of toner is reduced, the friction coefficient of the paper P is increased accordingly, and the paper P The conveying power of the is increased.

  Therefore, when the density of the adjustment pattern is higher than the density of the image to be actually printed (the ratio of the area where dots are formed to the area of the paper P), the adjustment pattern is printed. Since the conveyance force of the sheet P at that time becomes small, if the correction value γ is set to a value close to the boundary between the range where the rubbing S is formed and the range where the rubbing S is not formed, the rubbing S is formed. On the other hand, if the density of the adjustment pattern is lower than the density of the image to be actually printed, the conveyance force of the paper P when printing the adjustment pattern is increased. If γ is set to a value close to the boundary between the range where the image shift Z is formed and the range where the image shift Z is not formed, the image shift Z is formed.

  Therefore, the second embodiment of the present invention is configured to prevent the formation of the rubbing S and the image misalignment Z regardless of the amount of toner in the toner image transferred onto the paper P. explain. In addition, about the thing which has the same structure as the 1st Embodiment of this invention, the same code | symbol is provided and the effect of the same embodiment is used about the effect of the invention by having the same structure. Further, since the structure of the printer and the control device in the present embodiment is the same as the structure of the printer and the control device in the first embodiment, description will be made with reference to FIGS.

  FIG. 35 is a diagram showing an example of the adjustment pattern for rubbing detection in the second embodiment of the present invention, and FIG. 36 is a detailed view of the adjustment pattern for rubbing detection in the second embodiment of the present invention.

Also in the present embodiment, as in the first embodiment, the width is 210 [mm], the length is 1200 [mm], and the weighing is 128 [g / m ² ]. In the case of using the paper P as a medium of the scale, the transport speed Vb is set to 120 [mm / sec], and the fixing speed Vf is 0.25 [%] lower than the transport speed Vb, 119.7 [mm / sec]. The fixing temperature Tf is set to 170 [° C.].

  The fixing speed Vf can be changed in increments of a preset width. In this embodiment, the changing speed of the fixing speed Vf is set to +30, and the increment in increments of 0.1%. Is done.

When the correction value representing the change amount (number of steps) of the fixing speed Vf is γ, the changed fixing speed Vf ′ is
Vf ′ = (1 + 0.001 × γ) × Vf
become. In the present embodiment, the fixing speed Vf is 0.25 [%] lower than the transport speed Vb,
Vf = 0.9975 × Vb
Therefore, the fixing speed Vf ′ is
Vf ′ = (1 + 0.001 × γ) × (0.9975 × Vb)
become. The initial value of the correction value γ is set to zero.

  Next, an adjustment pattern for adjusting the fixing temperature Vf will be described.

  As shown in FIGS. 35 and 36, the rubbing detection adjustment pattern connects the left and right edges of the paper P on the paper P, and in a predetermined range in the length direction, the paper P in the present embodiment. From the rear end to the front end, a plurality of ruled lines are printed at predetermined intervals, in this embodiment, at equal intervals and in parallel. The adjustment pattern for rubbing detection is divided into a plurality of areas in the width direction of the paper P, in this embodiment, seven areas, that is, ruled line patterns PL1, PLK, PCM, PCC, PCY, PRK, PR1. . The ruled line pattern PC is constituted by the ruled line patterns PLK, PCM, PCC, PCY, and PRK. The interval ΔLg between the ruled lines is set to 10 [mm], but can be changed as necessary.

  Further, in the ruled line patterns PL1 and PR1, a scale serving as an index for adjusting the fixing speed Vf is given from the rear end to the front end of the paper P one by one. Then, the numerical value of +1 scale and the numerical value of a scale of multiples of +5 are surrounded by a frame fr so that the operator can easily see, and other numerical values are set as a vernier without being surrounded. A black toner is used for printing each ruled line and scale.

  In the ruled line pattern PC, the ruled line patterns PLK, PCM, PCC, PCY, and PRK are formed from black, magenta, cyan, yellow, and black toners from the ruled line pattern PL1 to the ruled line pattern PR1. . In the ruled line pattern PC, the entire area between the ruled lines is printed with the toner of each color so that it can be visually detected whether or not the image is rubbed with the conveyance of the paper P. The ratio of the area of the ruled line pattern PC to the area of the paper P is set to 60 [%].

  Next, an adjustment pattern for image shift detection will be described.

  FIG. 37 is a diagram showing an adjustment pattern for image misalignment detection according to the second embodiment of the present invention, and FIG. 38 is a detailed view of the latter half of the image misalignment detection adjustment pattern according to the second embodiment of the present invention. FIG. 39 is a diagram showing a main part of an adjustment pattern for image shift detection according to the second embodiment of the present invention.

  As shown in the figure, the image misalignment detection adjustment pattern connects the left and right edges of the paper P on the paper P, and in a predetermined range in the length direction, in this embodiment, after the paper P. From the end to the front end, a plurality of ruled lines are printed at predetermined intervals, in this embodiment, at equal intervals and in parallel. The image misalignment detection adjustment pattern is divided into a plurality of areas in the width direction of the paper P, in the present embodiment, five areas, that is, ruled line patterns PL1, PL2, PC, PR2, and PR1. The interval ΔLd between the ruled lines is set to 10 [mm], but can be changed as necessary.

  Further, the ruled line patterns PL1 and PR1 are each provided with a scale serving as an index for adjusting the fixing speed Vf from the rear end to the front end of the paper P. Then, the numerical value of the scale of -1 and the numerical value of the scale of multiples of -5 are surrounded by the frame fr so that the operator can easily see, and the other numerical values are not surrounded by the scale. A black toner is used for printing each ruled line and scale.

  The ruled line patterns PL2 and PR2 are rectangular patterns Cp ′ formed by cyan toner and having a rectangular shape and rectangular lines formed by black toner in the pattern Cp ′. It consists of a pattern Kp ′.

The pattern Cp ′ is formed to have an amount (overlap amount) ΔLf that spreads outward on the four sides with respect to the pattern Kp ′.
ΔLf = 200 [μm]
To be.

  When the pattern Kp ′ and the pattern Cp ′ are printed in either direction, for example, more than 200 [μm], between the pattern Kp ′ and the pattern Cp ′ (the outer periphery of the pattern Cp ′ and the pattern The pattern Np ′ made of the base of the paper P appears white and appears on the ruled line patterns PL2 and PR2 (between the Kp ′ frame). Note that the amount ΔLf can be changed as necessary.

  In this case, the pattern Cp ′ is formed using only cyan toner. This is because the image forming unit 22C (FIG. 1) is disposed at the furthest position in the conveyance direction of the paper P with respect to the image forming unit 22Bk, and therefore when the fixing speed Vf is changed, the pattern Cp ′. This is because the image shift appears most remarkably.

  Therefore, when the toner image of each color cannot be transferred to an accurate position, the operator can easily confirm that the image misregistration is formed by visually observing the ruled line patterns PL2 and PR2. it can.

  The ratio of the area of the ruled line patterns PL2 and PR2 to the area of the paper P is set to 5 [%].

  Next, a method for printing an adjustment pattern on the paper P, changing the fixing speed Vf based on the printing result, and an operation of the print control unit 61 (FIGS. 4 and 5) as a control unit will be described.

  FIG. 40 is a flowchart showing the operation of the print control unit according to the second embodiment of the present invention. FIG. 41 is a print result of the adjustment pattern for detecting rubbing when the rubbing is detected according to the second embodiment of the present invention. FIG. 42 is a first diagram showing a fixing speed adjusting method when rubbing is detected in the second embodiment of the present invention, and FIG. 43 is a diagram showing rubbing in the second embodiment of the present invention. FIG. 44 is a second diagram showing a method for adjusting the fixing speed when detected, FIG. 44 is a third diagram showing a method for adjusting the fixing speed when rubbing is detected in the second embodiment of the present invention, and FIG. FIG. 46 is a diagram showing a print result of an adjustment pattern for detecting image misalignment when image misalignment is detected in the second embodiment of the present invention; FIG. 46 is a diagram when image misalignment is detected in the second embodiment of the present invention. Adjustment patterns for detecting image misalignment FIG. 47 is a detailed diagram showing the results, FIG. 47 is a first diagram showing a method for adjusting the fixing speed when image misalignment is detected in the second embodiment of the present invention, and FIG. 48 is a second embodiment of the present invention. FIG. 49 shows a fixing speed adjustment method when image misalignment is detected in FIG. 49. FIG. 49 is a third diagram showing a fixing speed adjusting method when image misalignment is detected in the second embodiment of the present invention. FIG.

  First, in order to make custom settings in an online state, the operator sets the printing conditions for the custom media such as A4 size paper P when the size, thickness, type, etc. are common. Set item custom 1. Further, the operator sets the fixing speed Vf and sets the initial value of the correction value γ to zero.

  Next, printing is performed on the paper P. If no rubbing or image misalignment is formed on the image, there is no problem in the print result, and there is no need to change the setting of the item custom 1, so printing is terminated.

  On the other hand, when the image is rubbed or misaligned, the rubbing detection adjustment pattern and the image misalignment detection adjustment pattern for adjusting the fixing speed Vf are the same as in the first embodiment. Print. That is, as shown in FIG. 16, when the “color menu adjustment p” for printing the adjustment pattern is displayed on the liquid crystal display m1, when the key k1 is pressed, the adjustment pattern printing processing means 2 An adjustment pattern for rubbing detection and an adjustment pattern for image misalignment detection are printed on each sheet of paper P.

  At this time, it is possible to visually determine whether or not rubbing or image misalignment is formed in the adjustment pattern for detecting rubbing and the adjustment pattern for detecting image misalignment.

  For example, in the printing result shown in FIG. 41, the rubbing S ′ is formed obliquely in the latter half of the adjustment pattern.

In this case, since the rubbing S ′ is formed obliquely from the position “+6” of the scale to the rear end of the paper P, the rubbing position α is
α = + 6
Thus, it can be seen that the correction value γ is preferably set to +6.

  Next, a method for adjusting the fixing speed Vf will be described.

  First, as in the first embodiment, as shown in FIG. 25, in the state in which “Teaching Custom 1” for changing the fixing speed Vf of the item custom 1 is displayed on the liquid crystal display m1, When the key k1 is pressed, as shown in FIG. 42, “Teaching 0” representing the initial value for changing the fixing speed Vf is displayed on the liquid crystal display m1. In the liquid crystal display m1, “*” indicating that the fixing speed Vf is set to “0” in the initial state indicates that the fixing speed Vf of the item custom 1 is changed to the left of “0”. “K 1” is displayed to the right of “0”.

  Next, when the key k1 is pressed for a long time after the key k3 or the key k4 is pressed several times, as shown in FIG. 43, “Teaching Speed +6” for changing the fixing speed Vf is displayed on the liquid crystal display m1, “*” Indicating that the change has been determined is displayed to the left of “+6”.

In this way, when the correction value γ is set to +6 and determined, the fixing speed adjustment processing unit changes the fixing speed Vf based on the correction value γ. In this case, the changed fixing speed Vf ′ is
Vf ′ = (1 + 0.001 × 6) × Vf
= 1.006 × Vf
= 1.006 × 0.9975 × Vb
≒ 1.0035 x Vb
become.

  The recording processing unit records the fixing speed Vf ′ and the correction value γ in the storage unit 61a (FIG. 5).

  Subsequently, when the key k2 is pressed, as shown in FIG. 44, “Teaching Custom 1” is displayed on the liquid crystal display m1, and “*” indicating that the change has been determined is “Teaching Custom 1”. Is displayed to the left of. In this way, the operator can know that the fixing speed Vf has been changed.

  Then, similarly to the first embodiment, the adjustment pattern for rubbing detection is printed again, and it is visually determined whether or not the rubbing S ′ is formed in the adjustment pattern for rubbing detection.

  By the way, when the rubbing S ′ is formed at the position “+6”, if the correction value γ is set to at least +6 or more, the slackness of the paper P can be reduced. Therefore, even if the conveying force of the paper P changes, the rubbing S ′ can be prevented from being formed accordingly, and the margin of the correction value γ can be increased in the rubbing S ′.

  However, when the correction value γ is excessively increased, the changed fixing speed Vf ′ is increased by that amount, and when the cyan toner image is transferred in the image forming unit 22C (FIG. 1), the fixing device (fixing unit). ) May cause the paper P to be pulled.

  As a result, when the rubbing detection pattern is printed, no rubbing S ′ occurs in the rubbing detection pattern, but the toner image transferred by the image forming units 22Bk, 22Y, and 22M and the toner image transferred by the image forming unit 22C. An image shift is formed between the two.

For example, when the correction value γ is +13, the fixing speed Vf ′ is
Vf ′ = (1 + 0.001 × 13) × Vf
= 1.013 × Vf
= 1.013 × 0.9975 × Vb
≒ 1.0105 × Vb
Thus, the sheet P is pulled by the fixing unit 18 when the cyan toner image is transferred in the image forming unit 22C. As a result, for example, in the printing result shown in FIG. 45, the image misalignment Z ′ is formed in the four ruled line patterns PL2 and PR2 at the rear end in the adjustment pattern for image misalignment detection, as shown in FIG. The pattern Np ′ appears white for the length of the amount ΔLft. This is because the transport speed Vb when the toner image of the pattern Cp ′ is transferred in the image forming unit 22C is higher than the transport speed Vb when the toner image of the pattern Kp ′ is transferred in the image forming unit 22Bk. Therefore, the toner image transfer timing in the image forming unit 22C is apparently delayed.

  Therefore, in the present embodiment, the image shift Z 'is prevented from occurring by changing the fixing speed Vf.

In this case, as shown in FIG. 45, the image displacement Z ′ is formed from the position of “−4” on the scale to the rear end of the adjustment pattern for image displacement detection.
β = -4
Thus, it can be seen that it is preferable to add the correction value γ by −4.

  In the present embodiment, since negative values are used for the scale of the adjustment pattern for detecting the image shift, the image shift position β takes a negative value, but a positive value is used for the scale. In this case, the image shift position β takes a positive value.

  Then, as shown in FIG. 47, in the state where “adjustment menu takeout” for changing the fixing speed Vf is displayed on the liquid crystal display m1, the key k1 is pressed, and then the key k3 or the key k4. When is pressed several times, as shown in FIG. 48, “customized +13” of the item custom 1 for changing the fixing speed Vf is displayed on the liquid crystal display m1. Therefore, when the key k1 is pressed, the change of the fixing speed Vf is determined, and “*” indicating that the change has been determined is displayed to the left of “+13”.

  Next, when the key k3 is pressed four times, as shown in FIG. 49, “Teaching Speed +9” for changing the fixing speed Vf is displayed on the liquid crystal display m1.

When the key k1 is long pressed, the correction value γ is set to +9 and determined. Subsequently, the fixing speed adjustment processing unit changes the fixing speed Vf based on the correction value γ. In this case, the changed fixing speed Vf ′ is
Vf ′ = (1 + 0.001 × 9) × Vf
= 1.009 × Vf
= 1.009 × 0.9975 × Vb
≒ 1.0065 x Vb
become.

  The recording processing unit records the fixing speed Vf ′ and the correction value γ in the storage unit 61a.

  Thereafter, the adjustment pattern for detecting the image misalignment is printed again, and it is visually determined whether or not the image misalignment Z ′ is formed in the adjustment pattern. On the other hand, if no image misalignment Z ′ is formed in the adjustment pattern, the process ends.

  Incidentally, as described above, in the adjustment pattern for detecting rubbing, the ratio of the area of the ruled line pattern PC to the area of the paper P is set to 60 [%]. In the adjustment pattern, the ratio of the area of the ruled line patterns PL2 and PR2 to the area of the paper P is set to 5 [%].

  That is, in the present embodiment, the density of the adjustment pattern for rubbing detection can be increased and the density of the adjustment pattern for image shift detection can be decreased. Accordingly, since the density of the adjustment pattern for rubbing detection does not become lower than the density of the image to be actually printed, it is possible to prevent the conveyance force of the paper P when the adjustment pattern is printed from being reduced. . As a result, even if the correction value γ is set to a value close to the boundary between the range where the rubbing S ′ is formed and the range where the rubbing S ′ is not formed, the rubbing S ′ can be prevented from being formed. Further, since the density of the adjustment pattern for detecting image misalignment does not become higher than the density of the image to be actually printed, it is possible to prevent the conveyance force of the paper P when the adjustment pattern is printed from being increased. it can. As a result, even if the correction value γ is set to a value close to the boundary between the range where the image shift Z ′ is formed and the range where the image shift Z ′ is not formed, the image shift Z ′ can be prevented from being formed. .

As described above, in the present embodiment, the adjustment pattern for rubbing detection and the adjustment pattern for image shift detection can be printed independently, so that the printing conditions of each adjustment pattern can be made different. Therefore, when printing is actually performed, it is possible to prevent the formation of the rubbing S ′ and the image shift Z ′ regardless of the amount of toner of the toner image transferred to the paper P. The flowchart will be described.
Step S21: The correction value γ is set to zero.
Step S22 Printing is performed.
Step S23: It is determined whether the rubbing S ′ or the image shift Z ′ is formed. When the rubbing S ′ or the image shift Z ′ is formed, the process proceeds to step S24, and when it is not formed, the process is terminated.
Step S24: Print adjustment patterns for rubbing detection and image misalignment detection.
Step S25: It is determined whether or not the rubbing S ′ is formed. If rubbing S ′ is formed, the process proceeds to step S26, and if not, the process proceeds to step S28.
Step S26 The rubbing position α is confirmed.
Step S27: The value α is added to the correction value γ.
Step S28: It is determined whether or not the image shift Z ′ has been formed. When the image shift Z ′ is formed, the process proceeds to step S29, and when it is not formed, the process is terminated.
Step S29: Check the image shift position β.
Step S30: The value β is added to the correction value γ.
Step S31: The fixing speed Vf is changed.
Step S32: The changed fixing speed Vf ′ and correction value γ are recorded, and the process returns to step S24.

  In the present embodiment, in order to detect the rubbing S ′ and the image misalignment Z ′, the adjustment pattern is printed on the two sheets of paper P in one operation. Thus, it is not necessary to print the adjustment pattern on the two sheets of paper P.

  By the way, in the first and second embodiments, when the number of printed sheets increases, the conveyance roller portions 14, 15, and 19, the photosensitive drums 52Bk, 52Y, 52M, and 52C as the image carrier, and the first transfer member. The transfer belt 17 as a fixing member, the fixing roller 25 as a fixing member, the pressure roller 26 as a pressure member, the discharge roller section 20, and the like, that is, paper dust adheres to the surface of the conveying element, ie, the conveying surface Or the outer diameter becomes smaller due to wear of the transport roller portions 14, 15, 19, the photosensitive drums 52Bk, 52Y, 52M, 52C, the fixing roller 25, the pressure roller 26, the discharge roller portion 20, etc. The conveyance force is reduced. Each of the transport elements is also a maintenance part and a replacement part. Therefore, when printing is performed on a predetermined number of sheets of paper P, they are replaced as the service life. Therefore, the conveying force is increased only by the exchanged conveying element.

  Therefore, it is desirable to print the adjustment pattern each time the transport element is replaced, for example, to adjust the fixing speed Vf. However, if the adjustment pattern is printed each time the transport element is replaced, the toner is removed. It will consume a minute.

  In the second embodiment, the density of the toner image transferred to the paper P is related to the amount of toner by varying the densities of the adjustment pattern for detecting rubbing and the adjustment pattern for detecting image misalignment. However, when the density of the adjustment pattern for detecting the rubbing is higher than the density of the image to be actually printed, the image is not printed. When the density of the adjustment pattern for detecting deviation is lower than the density of the image to be actually printed, rubbing S ′ or image deviation Z ′ is formed.

  Therefore, when the number of printed sheets is large, the density of the adjustment pattern for detecting rubbing is higher than the density of the image to be actually printed, and the density of the adjustment pattern for detecting image misalignment is actually printed. A third embodiment of the present invention will be described in which it is possible to prevent the formation of the rubbing S ′ and the image shift Z ′ in any case such as when the density is lower than the density of the image to be printed. . In addition, about the thing which has the same structure as the said 1st, 2nd embodiment, the same code | symbol is provided and the effect of the embodiment is used about the effect of the invention by having the same structure. In addition, since the structure of the printer and the control device in the present embodiment is the same as the structure of the printer and the control device in the first embodiment of the present invention, the description will be given with reference to FIGS. To do.

  FIG. 50 is a diagram showing an example of an adjustment pattern for rubbing detection in the third embodiment of the present invention, and FIG. 51 is a detailed diagram of an adjustment pattern for rubbing detection in the third embodiment of the present invention.

Also in the present embodiment, as in the first and second embodiments, the width is 210 [mm], the length is 1200 [mm], and the weighing is 128 [g / m ² ]. When using the paper P as an A4 size long medium, the transport speed Vb is set to 120 [mm / sec], and the fixing speed Vf is 0.25 [%] lower than the transport speed Vb to 119.7 [mm]. / Sec] and the fixing temperature Tf is set to 170 [° C.].

  Further, the fixing speed Vf can be changed in increments of a preset width. In the present embodiment, the changing speed of the fixing speed Vf is ± 30, and the increment width is 0.1 [%]. To be.

When the correction value representing the change amount (number of steps) of the fixing speed Vf is γ, the changed fixing speed Vf ′ is
Vf ′ = (1 + 0.001 × γ) × Vf
become. In the present embodiment, the fixing speed Vf is 0.25 [%] lower than the transport speed Vb,
Vf = 0.9975 × Vb
Therefore, the fixing speed Vf ′ is
Vf ′ = (1 + 0.001 × γ) × (0.9975 × Vb)
become. The initial value of the correction value γ is set to zero.

  Next, an adjustment pattern for rubbing detection will be described.

  As shown in FIGS. 50 and 51, the adjustment pattern for rubbing detection connects the left and right edges of the paper P on the paper P, and in a predetermined range in the length direction, the paper P in the present embodiment. From the rear end to the front end, a plurality of ruled lines are printed at predetermined intervals, in this embodiment, at equal intervals and in parallel. The adjustment pattern for rubbing detection is divided into a plurality of areas in the width direction of the paper P, in this embodiment, seven areas, that is, ruled line patterns PL1, PLK, PCM, PCC, PCY, PRK, PR1. . The ruled line pattern PC is constituted by the ruled line patterns PLK, PCM, PCC, PCY, and PRK. The interval ΔLh between the ruled lines is set to 10 [mm], but can be changed as necessary.

  In this embodiment, the rubbing detection adjustment pattern is printed from the rear end to the front end of the paper P. However, it is not always necessary to print from the rear end to the front end of the paper P. And in this Embodiment, although each ruled line is formed at equal intervals, it does not need to be equal intervals.

  Further, in the ruled line patterns PL1 and PR1, a scale serving as an index for adjusting the fixing temperature Vf is given from the rear end to the front end of the paper P one by one. Then, the numerical value of +1 scale and the numerical value of a scale of multiples of +5 are surrounded by a frame fr so that the operator can easily see, and other numerical values are set as a vernier without being surrounded. Note that black toner is used for printing the ruled lines and scales.

  In the ruled line pattern PC, the ruled line patterns PLK, PCM, PCC, PCY, and PRK are formed from black, magenta, cyan, yellow, and black toners from the ruled line pattern PL1 to the ruled line pattern PR1. . In the ruled line pattern PC, the entire area between the ruled lines is printed with the toner of each color so that it can be visually detected whether or not the image is rubbed with the conveyance of the paper P. The ratio of the area of the ruled line pattern PC to the area of the paper P is set to 10 [%].

  Next, an adjustment pattern for image shift detection will be described.

  FIG. 52 is a diagram showing an adjustment pattern for image shift detection according to the third embodiment of the present invention. In this case, since the same adjustment pattern (FIGS. 38 and 39) as in the second embodiment is used, detailed description thereof is omitted.

  By the way, even if the fixing speed Vf is changed based on the correction value γ, as described above, the number of printed sheets is large, the conveying element is worn, the conveying element is replaced, or an adjustment pattern for detecting rubbing is detected. Factors that cause the fixing speed Vf to fluctuate because the density is higher than the density of the image to be actually printed or the density of the adjustment pattern for detecting image misalignment is lower than the density of the image to be actually printed. If there is, rubbing or image misalignment will be formed.

  Therefore, in the present embodiment, when printing the adjustment pattern for rubbing detection and the adjustment pattern for image shift detection, the conveyance speed correction processing unit (not shown) of the calculation unit 61b (FIG. 5) performs the conveyance speed correction processing. The fixing speed Vf is corrected by assuming a factor that fluctuates the fixing speed Vf, and the paper P is conveyed at the corrected fixing speed Vf, that is, the corrected fixing speeds Vx and Vy. The corrected conveyance speed is configured by the corrected fixing speeds Vx and Vy.

  Here, generally, when printing is performed on the paper P, the maximum ratio of the area of the formed image to the area of the paper P is 80% for each color. In addition, the said maximum value in this Embodiment is an example, and is good also as 100 [%].

  Therefore, when a predetermined paper P (recommended paper) is used as the paper P and the ratio of the area of the ruled line pattern PC to the area of the paper P is set to 10 [%], the rubbing position when the printing is performed is α1. The rubbing position when printing is performed with the ratio of the area of the formed image to the area of the paper P being 80%, and α2 is the rubbing position, and the relationship between the rubbing positions α1 and α2, that is, the difference is Determined experimentally. Based on the difference, a correction value for correcting the fixing speed Vf was calculated when the adjustment pattern for rubbing detection was printed. As a result, the correction value was −0.3 [%].

  Similarly, the ratio of the area of the ruled line patterns PL1 and PR1 to the area of the paper P is set to 5% as in the second embodiment, and the fixing speed when printing is performed. The fixing speed when printing was performed without forming an image on the paper P was set as Vf1, and the difference between the fixing speeds Vf1 and Vf2 was experimentally obtained. Based on the difference, a correction value for correcting the fixing speed Vf was calculated when the adjustment pattern for image misalignment detection was printed, and the correction value was +0.1 [%].

Therefore, in the present embodiment, the fixing speed Vf when the adjustment pattern for rubbing detection is printed is corrected by the correction value −0.3 [%], and the corrected fixing speed Vx is corrected.
Vx = (1−0.003) × Vf
= 0.997 x Vf
≒ 0.9945 × Vb
And the fixing speed Vf when printing with the adjustment pattern for detecting image misalignment is corrected by the correction value +0.1 [%], and the corrected fixing speed Vy is corrected.
Vy = (1 + 0.001) × Vf ′
= 1.001 × Vf ′
≒ 0.9985 × Vb
Was calculated.

  In this way, the fixing speed Vf when printing the adjustment pattern for detecting rubbing is lowered by the correction, and the fixing speed Vf when printing with the adjustment pattern for detecting image shift is raised by the correction.

  Next, a method for printing the adjustment pattern on the paper P and changing the fixing speed Vf based on the printing result, and the operation of the print control unit 61 will be described.

  FIG. 53 is a first flowchart showing the operation of the print control unit in the third embodiment of the present invention. FIG. 54 is a second flowchart showing the operation of the print control unit in the third embodiment of the present invention. FIG. 55 is a diagram showing a print result of an adjustment pattern for detecting rubbing when rubbing is detected in the third embodiment of the present invention. FIG. 56 is a diagram showing image misalignment detected in the third embodiment of the present invention. FIG. 57 is a diagram illustrating a printing result of an adjustment pattern for detecting image misalignment, FIG. 57 is a first diagram illustrating a fixing speed adjusting method when rubbing is detected in the third embodiment of the present invention, and FIG. FIG. 59 is a second diagram showing a method for adjusting the fixing speed when rubbing is detected in the third embodiment of the present invention, and FIG. 59 is a graph of fixing speed when rubbing is detected in the third embodiment of the present invention. It is a 3rd figure which shows the adjustment method

  First, in order to make a custom setting in an online state, the operator sets, for example, the printing conditions when the size, thickness, type, etc. are general, such as A4 size paper P, to item custom 1 To do. Further, the operator sets the fixing speed Vf and sets the initial value of the correction value γ to zero.

  Next, printing is performed on the paper P. If no rubbing or image misalignment is formed on the image, there is no problem in the print result, and there is no need to change the setting of the item custom 1, so printing is terminated.

  On the other hand, when the image is rubbed or misaligned, the same procedure as in the first embodiment is used for the adjustment pattern for rubbing detection and the adjustment pattern for image misalignment detection for adjusting the fixing speed Vf. Print with. That is, as shown in FIG. 16, when the key k1 is pressed while the “color menu adjustment p” for printing the adjustment pattern is displayed on the liquid crystal display m1, the adjustment pattern printing processing means rubs. In order to print an adjustment pattern for detection, a correction fixing speed Vx is calculated and set, and an adjustment pattern for rubbing detection is printed. Subsequently, the adjustment pattern print processing unit calculates and sets a correction fixing speed Vy for printing an adjustment pattern for image misalignment detection, and prints the adjustment detection pattern for image misalignment detection.

  At this time, it is possible to visually determine whether or not rubbing or image misalignment is formed in the adjustment pattern for detecting rubbing and the adjustment pattern for detecting image misalignment.

  For example, in the printing result shown in FIG. 55, the rubbing S ″ is formed obliquely in the latter half of the rubbing detection adjustment pattern.

In this case, the rubbing S ″ is formed obliquely from the position of “+6” on the scale to the rear end of the paper P, so that the rubbing position α is
α = + 6
Thus, it can be seen that the correction value γ is preferably set to +6.

  Next, a method for adjusting the fixing speed Vf will be described.

  First, as in the second embodiment, as shown in FIG. 42, “Teacher 0” indicating the initial value for changing the fixing speed Vf of “Custom 1” is displayed on the liquid crystal display m1. In this state, when the key k1 is pressed for a long time after the key k3 or the key k4 is pressed several times, as shown in FIG. 43, “Teaching Speed +6” for changing the fixing speed Vf is displayed on the liquid crystal display m1. “*” Indicating that the change has been determined is displayed to the left of “+6”.

In this way, when the correction value γ is set to +6 and determined, the fixing speed adjustment processing unit changes the fixing speed Vf based on the correction value γ. In this case, the changed fixing speed Vf ′ is
Vf ′ = (1 + 0.001 × 6) × Vf
= 1.006 × Vf
= 1.006 × 0.9975 × Vb
≒ 1.0035 x Vb
become.

  The recording processing unit records the fixing speed Vf ′ and the correction value γ in the storage unit 61a (FIG. 5).

  Subsequently, when the key k2 is pressed, as shown in FIG. 44, “Teaching Custom 1” is displayed on the liquid crystal display m1, and “*” indicating that the change has been determined is “Teaching Custom 1”. Is displayed to the left of. In this way, the operator can know that the fixing speed Vf has been changed.

  Then, as in the first embodiment, the adjustment pattern for rubbing detection is printed again, and it is visually determined whether or not rubbing S ″ is formed on the rubbing detection adjustment pattern.

  By the way, when the rubbing S ″ is formed at the position “+6”, the slackness of the paper P can be reduced by setting the correction value γ to at least +6 or more. Therefore, even if the conveyance force of the paper P changes, the rubbing S ″ can be prevented from being formed accordingly, and the margin of the correction value γ can be increased in the rubbing S ″.

  However, when the correction value γ is excessively increased, the changed fixing speed Vf ′ is increased by that amount, and when the cyan toner image is transferred in the image forming unit 22C (FIG. 1), the fixing device (fixing unit). ) May cause the paper P to be pulled.

  As a result, when the adjustment pattern for rubbing detection is printed, rubbing S ″ does not occur in the rubbing detection adjustment pattern, but the toner image transferred by the image forming units 22Bk, 22Y, and 22M and the image forming unit 22C. An image shift is formed between the transferred toner image.

For example, when the correction value γ is +13, the fixing speed Vf ′ is
Vf ′ = (1 + 0.001 × 13) × Vf
= 1.013 × Vf
= 1.013 × 0.9975 × Vb
≒ 1.0105 × Vb
Thus, the sheet P is pulled by the fixing unit 18 when the cyan toner image is transferred in the image forming unit 22C. As a result, for example, in the printing result shown in FIG. 56, image displacement Z ″ is formed in the five ruled line patterns PL2 and PR2 in the adjustment pattern for image displacement detection.

  Therefore, in the present embodiment, the image shift Z ″ is prevented from occurring by changing the fixing speed Vf.

In this case, the image misalignment Z ″ is formed from the position “−5” of the scale to the rear end of the sheet P.
β = -5
Thus, it can be seen that it is preferable to add the correction value γ by −5.

  In the present embodiment, since negative values are used for the scale of the adjustment pattern for detecting the image shift, the image shift position β takes a negative value, but a positive value is used for the scale. In this case, the image shift position β takes a positive value.

  Then, as shown in FIG. 57, in the state where the “adjustment menu for changing the fixing speed Vf” is displayed on the liquid crystal display m1, the key k1 is pressed, and then the key k3 or the key k4. When the button is pressed several times, as shown in FIG. 58, “customized +13” of the item custom 1 for changing the fixing speed Vf is displayed on the liquid crystal display m1. When the key k1 is pressed, the change of the fixing speed Vf is determined, and “*” indicating that the change has been determined is displayed to the left of “+13”.

  Next, when the key k3 is pressed five times, as shown in FIG. 59, “Teaching Speed +8” for changing the fixing speed Vf is displayed on the liquid crystal display m1.

When the key k1 is pressed for a long time, the correction value γ is set to +8 and determined. Then, the fixing speed adjusting means changes the fixing speed Vf based on the correction value γ. In this case, the changed fixing speed Vf ′ is
Vf ′ = (1 + 0.001 × 8) × Vf
= 1.008 × Vf
= 1.008 × 0.9975 × Vb
≒ 1.0055 x Vb
become.

  The recording processing unit records the fixing speed Vf ′ and the correction value γ in the storage unit 61a.

  Thereafter, an adjustment pattern for image misalignment detection is printed again, and it is visually determined whether or not an image misalignment Z ″ is formed in the image misalignment detection adjustment pattern. If no image misalignment Z ″ has been formed, the process ends.

  As described above, in the present embodiment, the fixing speed Vf is corrected in advance assuming the factor that the fixing speed Vf fluctuates, and the adjustment pattern for rubbing detection and the image misalignment detection are detected based on the corrected fixing speeds Vx and Vy. Since the adjustment pattern is printed, even if there is a factor that the fixing speed Vf varies, it is possible to prevent the image from being rubbed S ″ or image shift Z ″. In addition, since the fixing speed Vf is corrected in advance, the ratio of the area of the adjustment pattern to the area of the paper P can be reduced. Therefore, toner consumption can be reduced.

Next, a flowchart will be described.
Step S41: The correction value γ is set to zero.
Step S42 Printing is performed.
Step S43: It is determined whether the rubbing S "or the image shift Z" is formed. If rubbing S "or image shift Z" is formed, the process proceeds to step S44, and if not formed, the process is terminated.
Step S44: The corrected fixing speeds Vx and Vy are calculated.
Step S45: An adjustment pattern for rubbing detection is printed at the corrected fixing speed Vx.
Step S46: An adjustment pattern for image misalignment detection is printed at the corrected fixing speed Vy.
Step S47: It is determined whether or not the rubbing S ″ is formed. If the rubbing S ″ is formed, the process proceeds to Step S48, and if not, the process proceeds to Step S50.
Step S48 The rubbing position α is confirmed.
Step S49: The value α is added to the correction value γ.
Step S50: It is determined whether or not the image misalignment Z ″ is formed. If the image misalignment Z ″ is formed, the process proceeds to Step S51, and if it is not formed, the process is terminated.
Step S51 The image shift position β is confirmed.
Step S52: The value β is added to the correction value γ.
Step S53: The fixing speed Vf is changed.
Step S54 The changed fixing speed Vf ′ and the correction value γ are recorded, and the process returns to Step S44.

  In the present embodiment, a correction value for correcting the fixing speed Vf is calculated by printing an adjustment pattern for rubbing detection and an adjustment pattern for image shift detection on paper P (recommended paper). However, it is also possible to correct the fixing speed Vf by recording correction values corresponding to the thickness, size, and the like of the paper P in the storage unit 61a and reading out the correction values. Further, as the number of printed sheets increases, the conveyance surface of each conveyance element deteriorates or the outer diameter gradually decreases due to wear, so that the correction value can be changed according to the number of printed sheets. For example, as the number of printed sheets increases, the correction value of the correction fixing speed Vx is decreased, and the correction value of the correction fixing speed Vy is increased.

  In the present embodiment, the adjustment pattern for detecting rubbing and the adjustment pattern for detecting misregistration are printed, respectively. However, rubbing and misregistration can be detected by one adjustment pattern. .

  In each of the embodiments, the adjustment pattern is printed from the rear end to the front end of the paper P. However, it is not always necessary to print from the rear end to the front end of the paper P. Moreover, in each embodiment, although each ruled line is formed at equal intervals, it does not need to be equal intervals.

  Further, in each of the above embodiments, the rubbing and image misalignment are prevented by adjusting the conveyance speed Vf by the fixing device 18, but fixing as a fixing member by a cam mechanism or the like. By changing the nip amount or the nip pressure between the roller 25 and the pressure roller 26 as the pressure member, it is possible to prevent rubbing and image misalignment.

  In each embodiment, the case where the fixing speed Vf of the fixing device 18 is changed has been described. However, in addition to the fixing speed Vf, the conveyance speed and image formation in the conveyance unit 201 as the first medium conveyance unit are described. The conveyance speed Vb between the units 22Bk, 22Y, 22M and the transfer unit u1 and the conveyance speed in the discharge unit 31 can be changed based on the correction value γ to form an appropriate slack.

In each embodiment, when using A4 size paper P having a width of 210 [mm], a length of 1200 [mm], and a weighing of 128 [g / m ² ] However, papers having different widths, lengths, weighings, etc. can be used.

  In each embodiment, an adjustment pattern print command, adjustment of the fixing speed Vf, and the like are performed by operating the operation unit 102 of the printer, but the printer is directly connected to the printer or via a network. It is also possible to perform adjustment pattern printing commands, fixing speed Vf adjustment, and the like using a host computer, a dedicated remote controller, or the like.

  Further, in each of the above-described embodiments, a tandem type electrophotographic printer is described. However, the present invention can be applied to a monochrome electrophotographic printer, or an electrophotographic method such as a laser method or an intermediate transfer method. The present invention can be applied to a printer or an image forming apparatus such as a copying machine, a facsimile, or a multifunction machine other than the printer.

  The present invention is not limited to the above embodiments, and various modifications can be made based on the gist of the present invention, and they are not excluded from the scope of the present invention.

1 is a conceptual diagram of a printer according to a first embodiment of the present invention. It is a figure which shows the principal part of the conventional printer. FIG. 3 is a diagram illustrating a display unit and an operation unit of the printer according to the first embodiment of the present invention. 1 is a first block diagram illustrating a printer control device according to a first embodiment of the present invention. FIG. It is a 2nd block diagram which shows the control apparatus of the printer in the 1st Embodiment of this invention. FIG. 5 is a diagram illustrating a display unit and an operation unit when the fixing speed is custom-set according to the first exemplary embodiment of the present invention. It is a figure which shows the example of the adjustment pattern in the 1st Embodiment of this invention. It is detail drawing of the second half part of the adjustment pattern in the 1st Embodiment of this invention. It is a figure which shows the principal part of the adjustment pattern in the 1st Embodiment of this invention. 3 is a flowchart illustrating an operation of a print control unit according to the first embodiment of the present invention. It is a 1st figure which shows the printing method of the adjustment pattern in the 1st Embodiment of this invention. It is a 2nd figure which shows the printing method of the adjustment pattern in the 1st Embodiment of this invention. It is a 3rd figure which shows the printing method of the adjustment pattern in the 1st Embodiment of this invention. It is a 4th figure which shows the printing method of the adjustment pattern in the 1st Embodiment of this invention. It is a 5th figure which shows the printing method of the adjustment pattern in the 1st Embodiment of this invention. It is a 6th figure which shows the printing method of the adjustment pattern in the 1st Embodiment of this invention. It is a figure which shows the printing result of the adjustment pattern when the rubbing in the 1st Embodiment of this invention is detected. FIG. 6 is a first diagram illustrating a method for adjusting a fixing speed when rubbing is detected in the first embodiment of the present invention. FIG. 10 is a second diagram illustrating a fixing speed adjustment method when rubbing is detected in the first embodiment of the present invention. FIG. 10 is a third diagram showing a fixing speed adjustment method when rubbing is detected in the first embodiment of the present invention. FIG. 10 is a fourth diagram illustrating a fixing speed adjustment method when rubbing is detected in the first embodiment of the present invention. FIG. 10 is a fifth diagram illustrating a fixing speed adjustment method when rubbing is detected in the first embodiment of the present invention. FIG. 10 is a sixth diagram illustrating a fixing speed adjustment method when rubbing is detected in the first embodiment of the present invention. FIG. 10 is a seventh diagram illustrating a fixing speed adjustment method when rubbing is detected in the first embodiment of the present invention. FIG. 10 is an eighth diagram illustrating a fixing speed adjustment method when rubbing is detected in the first embodiment of the present invention. FIG. 10 is a ninth diagram illustrating a fixing speed adjustment method when rubbing is detected in the first embodiment of the present invention. FIG. 10 is a tenth diagram illustrating a fixing speed adjustment method when rubbing is detected in the first embodiment of the present invention. FIG. 15 is an eleventh view showing a fixing speed adjustment method when rubbing is detected in the first embodiment of the present invention. FIG. 12 is a twelfth diagram illustrating a fixing speed adjustment method when rubbing is detected in the first embodiment of the present invention. It is a figure which shows the printing result of the adjustment pattern when the image shift in the 1st Embodiment of this invention is detected. FIG. 7 is a detailed diagram illustrating a printing result of an adjustment pattern when an image shift is detected in the first embodiment of the present invention. FIG. 6 is a first diagram illustrating a fixing speed adjustment method when image shift is detected in the first embodiment of the present invention. FIG. 6 is a second diagram illustrating a fixing speed adjustment method when image shift is detected in the first embodiment of the present invention. FIG. 9 is a third diagram illustrating a fixing speed adjustment method when image shift is detected in the first embodiment of the present invention. It is a figure which shows the example of the adjustment pattern for a rubbing detection in the 2nd Embodiment of this invention. It is a detailed view of an adjustment pattern for rubbing detection in the second embodiment of the present invention. It is a figure which shows the adjustment pattern for the image shift detection in the 2nd Embodiment of this invention. It is a detail drawing of the second half part of the adjustment pattern for image shift detection in the second embodiment of the present invention. It is a figure which shows the principal part of the adjustment pattern for image shift detection in the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the printing control part in the 2nd Embodiment of this invention. FIG. 10 shows a print result of a rubbing detection adjustment pattern when rubbing is detected in the second embodiment of the present invention. FIG. 10 is a first diagram illustrating a fixing speed adjustment method when rubbing is detected in the second embodiment of the present invention. FIG. 10 is a second diagram illustrating a fixing speed adjustment method when rubbing is detected in the second embodiment of the present invention. FIG. 10 is a third diagram illustrating a fixing speed adjustment method when rubbing is detected in the second embodiment of the present invention. It is a figure which shows the printing result of the adjustment pattern for image misalignment detection when the image misalignment in the 2nd Embodiment of this invention is detected. FIG. 10 is a detailed diagram illustrating a printing result of an image misalignment detection adjustment pattern when image misalignment is detected in the second embodiment of the present invention. FIG. 10 is a first diagram illustrating a method for adjusting a fixing speed when an image shift is detected according to the second exemplary embodiment of the present invention. FIG. 10 is a second diagram illustrating a fixing speed adjustment method when image shift is detected according to the second exemplary embodiment of the present invention. FIG. 9 is a third diagram illustrating a fixing speed adjustment method when image shift is detected in the second embodiment of the present invention. It is a figure which shows the example of the adjustment pattern for a rubbing detection in the 3rd Embodiment of this invention. It is a detailed view of the adjustment pattern for rubbing detection in the 3rd Embodiment of this invention. It is a figure which shows the adjustment pattern for the image shift detection in the 3rd Embodiment of this invention. It is a 1st flowchart which shows operation | movement of the printing control part in the 3rd Embodiment of this invention. It is a 2nd flowchart which shows operation | movement of the printing control part in the 3rd Embodiment of this invention. It is a figure which shows the printing result of the adjustment pattern for a rubbing detection when the rubbing is detected in the 3rd Embodiment of this invention. FIG. 10 is a diagram illustrating a printing result of an adjustment pattern for detecting image misalignment when image misalignment is detected in the third exemplary embodiment of the present invention. FIG. 12 is a first diagram illustrating a fixing speed adjustment method when rubbing is detected in the third embodiment of the present invention. FIG. 10 is a second diagram illustrating a fixing speed adjustment method when rubbing is detected in the third embodiment of the present invention. FIG. 10 is a third diagram illustrating a fixing speed adjustment method when rubbing is detected in the third embodiment of the present invention.

Explanation of symbols

18 Fixing Units 22Bk, 22Y, 22M, 22C Image Forming Unit 61a Storage Unit 61b Calculation Unit 201 Conveying Unit P Paper

Claims (10)

(A) an upstream medium transport unit that transports the medium to transfer the developer image formed in the image forming unit to the medium;
(B) a downstream medium conveyance unit that is disposed downstream of the upstream medium conveyance unit in the medium conveyance direction and conveys the medium;
(C) having a conveyance speed adjustment processing unit that adjusts a medium conveyance speed by the downstream medium conveyance unit based on a position where a disturbance is formed in an image when a predetermined adjustment pattern is printed. An image forming apparatus.   The image forming apparatus according to claim 1, wherein the downstream medium transport unit is a fixing unit.   The image forming apparatus according to claim 1, wherein the transport speed adjustment processing unit corrects the transport speed of the medium recorded in the storage unit with a correction value representing a position where a disturbance is formed in the image. (A) A plurality of the image forming units are arranged along the conveyance direction of the medium,
(B) The image forming apparatus according to any one of claims 1 to 3, wherein the adjustment pattern is printed by the most upstream image forming unit and the most downstream image forming unit among the image forming units. .   The said conveyance speed adjustment process means adjusts the conveyance speed of a medium based on the position where the rubbing was formed in the image, and the position where the image gap was formed in the image. Image forming apparatus.   The image forming apparatus according to claim 1, wherein a ratio of an area of the adjustment pattern for detecting image rubbing to an area of the medium is 60% or more.   The image forming apparatus according to claim 1, wherein a ratio of an area of the adjustment pattern for detecting the image shift to an area of the medium is 5% or less.   The image forming apparatus according to claim 1, further comprising a conveyance speed correction processing unit that corrects a conveyance speed of the medium when the adjustment pattern is printed.   The image forming apparatus according to claim 8, wherein the transport speed correction processing unit lowers the transport speed of the medium when the adjustment pattern for detecting image rubbing is printed by correction.   The image forming apparatus according to claim 8, wherein the conveyance speed correction processing unit increases the conveyance speed of the medium when printing an adjustment pattern for detecting image misalignment by correction.

Images