JP2011043664A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus, wherein the temperature difference generating between a paper passing region and a paper non-passing region in paper with a narrow width is made small in a fixing part having a prescribed width. <P>SOLUTION: The image forming apparatus carries out image formation to a first transferred material and a second transferred material that has a shorter length in the width direction than the first transferred material. The image forming apparatus alternately carries out a process for conveying a prescribed number of sheets of the first transferred material continuously to a conveying path L and a process for conveying a prescribed number of sheets of the second transferred material continuously to the conveying path L, when the image forming instruction information including the information on the number of sheets where the number of sheets for the first transferred material is set to be the prescribed number of sheets or more and the image forming information including the information on the number of sheets where the number of sheet of the second transferred material is set to be the prescribed number of sheets or more, are continuously received within a prescribed period. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  The copying machine includes a transfer unit that directly or indirectly transfers a toner image formed on a photosensitive drum onto a sheet (a material to be transferred), and a fixing unit that fixes the toner image transferred onto the sheet onto the sheet. The fixing unit includes a heating roller heated by a heater and a pressure roller pressed against the heating roller. The fixing unit fixes the toner image on the sheet by sandwiching the sheet conveyed from the transfer unit between the heating roller and the pressure roller to melt and press the toner image.

  Such a copier can print a plurality of sizes of paper (large size paper and small size paper). When large-size paper is passed through the fixing unit, the large-size paper passes through the entire width direction of the heating roller. When passing a small-size sheet through the fixing unit, the small-size sheet passes through a central portion (a part) in the width direction of the heating roller. When a plurality of small size papers are passed through the fixing unit, the temperature of the central part of the heating roller (paper passage area) is lowered because the heat of the heating roller is taken away by the paper. On the other hand, both ends (sheet non-passing area) of the heating roller continue to be heated, so that the temperature rises. Specifically, as shown in FIG. 8, when 100 small-size sheets (A5T (A5 portrait)) are passed through the fixing unit, the temperature of the heating roller is about 180 ° C. in the sheet passing area. On the other hand, the sheet non-passing area is about 230 ° C.

  When passing a plurality of such small size papers through the fixing unit and then continuously passing large size papers through the fixing unit, it was a paper passing area and a paper non-passing area of the small size paper. The amount of heat applied from the heating roller to large-size paper differs depending on the portion. For this reason, high temperature offset occurs in large size paper. Specifically, as shown in FIG. 8, when a large size paper (A4Y (A4 landscape)) is passed through the fixing unit after the small size paper (A5T), the portion indicated by the diagonal lines of the A4Y paper (small size) A portion of the paper corresponding to the paper non-passing area) has a high temperature offset.

  In order to solve the problem of high temperature offset, after passing small size paper through the fixing unit, the pressure roller is rotated backward to lower the temperature of the paper non-passing area, and then large size paper is fed to the fixing unit. An image forming apparatus for passing paper is proposed (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-254269

  However, in the invention described in Patent Document 1, it is necessary to make the temperature of the pressure roller uniform from the time when the small size paper is passed through the fixing unit to the time when the large size paper is passed through the fixing unit. It takes a long time. For this reason, in the invention described in Patent Document 1, there is a problem in that the time for printing small-size paper and large-size paper becomes long, and the processing capability for performing printing decreases.

  The present invention includes a fixing device having a heating rotator, and is a temperature difference that occurs in a region of the heating rotator in contact with a transfer material, which is a difference in length in the width direction that intersects the conveyance direction of the transfer material. An object of the present invention is to provide an image forming apparatus capable of suppressing a temperature difference caused by the temperature difference.

  The present invention includes a first storage portion that stores a sheet-like first transfer material, and a second transfer material that is sheet-like and shorter in the width direction than the first transfer material. A second storage section, a transport path for transporting the first transfer material and / or the second transfer material in a direction orthogonal to the width direction, and an image carrier on which an electrostatic latent image is formed A developing device that develops a toner image on an electrostatic latent image formed on the image carrier, and the first transfer material and the second transfer material conveyed by the conveyance path, A transfer unit that directly or indirectly transfers the toner image formed on the image carrier, and the toner image transferred to the first transfer material and the second transfer material by the transfer unit is heated, By melting the toner image, the toner image is transferred to the first transfer material and the second transfer material. A fixing unit that fixes the toner, the first transfer material stored in the first storage unit, and the second transfer material stored in the second storage unit are selectively carried into the conveyance path. A carry-in unit; a receiving unit capable of receiving at least image type instruction information including type information relating to a type of transfer material on which an image is to be formed; and number information relating to the number of transfer materials; Image forming instruction information including type information to be transferred material and number information of the number of the first transferred material being a predetermined number or more, type information to be transferred material is the second transferred material, and the second transferred image When the receiving unit continuously receives within a predetermined time the image forming information including the number information of the number of materials equal to or greater than the predetermined number, the predetermined number of first transferred materials are continuously carried into the conveyance path. And a predetermined number of second transfer materials A control unit for controlling the loading unit so as to perform alternately and process for carrying the transport path, an image forming apparatus including the.

  In addition, the control unit includes, within a predetermined time, the image forming instruction information including type information in which the receiving unit sets the transfer material as the first transfer material, and type information that sets the transfer material as the second transfer material. When the image forming information including the image forming information is received, it is preferable to control the carry-in unit so that the process of continuously carrying the predetermined number of first transfer materials into the carrying path is performed first.

  In addition, a process of continuously carrying a predetermined number of first transfer materials into the transport path by the carry-in unit and a process of continuously carrying a predetermined number of second transfer materials into the transport path are alternately performed. It is preferable to further include a display unit that performs predetermined notification display.

  Moreover, it is preferable to further include a display control unit that controls the display unit to turn off the predetermined notification display after a predetermined time has elapsed.

  Further, an erasure instruction unit that outputs erasure instruction information for erasing the predetermined notification display displayed on the display unit, and the predetermined notification display is erased based on the erasure instruction information output from the erasure instruction unit. It is preferable to further include a display control unit that controls the display unit.

  The present invention also provides a first storage unit that stores a sheet-like first transfer material, and a second transfer material that is sheet-like and shorter in the width direction than the first transfer material. An electrostatic latent image is formed on the surface of the second storage portion in which the first transfer material and / or the second transfer material are transported in a direction orthogonal to the width direction. An image carrier, a developer for developing a toner image on the electrostatic latent image formed on the image carrier, and the first transfer material and / or the second transfer material conveyed by the conveyance path. On the other hand, a transfer portion that directly or indirectly transfers the toner image formed on the image carrier, and the toner image transferred to the first transfer material and the second transfer material by the transfer portion. The first transferred material and the second transferred material are heated by heating and melting the toner image. The conveyance path selectively includes a fixing unit that fixes the toner image, the first transfer material stored in the first storage unit, and the second transfer material stored in the second storage unit. A receiving unit that can receive image forming instruction information including at least a type information on a type of a transfer material on which an image is formed and a number information on the number of transfer materials; and a transfer material. The receiving unit continuously receives image formation instruction information including type information for the first transfer material and image formation information including type information for the transfer material as the second transfer material within a predetermined time. A control unit that controls the carry-in unit so that the first transfer material is carried into the conveyance path before the second transfer material.

  According to the present invention, a fixing device having a heating rotator is provided, and a temperature difference that occurs in a region of the heating rotator where the transfer material comes into contact, which has a length in the width direction that intersects the conveyance direction of the transfer material. The temperature difference resulting from the difference can be suppressed.

FIG. 3 is a diagram for explaining an arrangement of each component of the copier 1 according to the embodiment of the present invention. 3 is a plan view illustrating an outline of an internal structure of a reading unit 301 of the image reading apparatus 300. FIG. FIG. 3 is a diagram of a reading unit 301 of the image reading apparatus 300 viewed from the main scanning direction Y. It is a figure which shows the outline | summary of the moving mechanism 370 of the illumination unit 347 and the mirror unit 349. FIG. 3 is a functional block diagram for explaining functions of characteristic portions in the copier 1. FIG. 5 is a flowchart for explaining the operation of the copier 1. FIG. FIG. 6 is a diagram for explaining the order of passing sheets T and the temperature of the fixing unit 9. FIG. 7 is a diagram for explaining the order of supplying sheets of a copying machine according to the prior art and the temperature of the fixing unit 9.

Hereinafter, embodiments of an image forming apparatus of the present invention will be described with reference to the drawings.
With reference to FIG. 1, the overall structure of a copier 1 as an image forming apparatus in the present embodiment will be described. FIG. 1 is a diagram for explaining the arrangement of components of a copier 1 according to an embodiment of the present invention.

As shown in FIG. 1, a copier 1 as an image forming apparatus is disposed on an upper side in the vertical direction Z of the copier 1 and on a lower side of the copier 1 in the vertical direction Z. An apparatus main body M that forms a toner image on a sheet T as a sheet-like transfer material based on image information read by the image reading apparatus 300.
In the description of the copying machine 1, the sub-scanning direction X is also referred to as the “left-right direction” of the copying machine 1, and the main scanning direction Y (direction passing through FIG. 1, see FIG. 2) is also referred to as the “front-rear direction” of the copying machine 1. Say. The vertical direction Z of the copier 1 is orthogonal to the sub-scanning direction X and the main scanning direction Y.

First, the image reading apparatus 300 will be described.
As shown in FIG. 1, the image reading apparatus 300 includes a reading unit 301 that reads an image of a document G, and a document conveying unit 70 that is arranged above the reading unit 301 and conveys the document G to the reading unit 301. .

  The reading unit 301 includes a housing 306, and a first reading surface 302 </ b> A and a second reading surface 302 </ b> B disposed on the upper side of the housing 306. The reading unit 301 includes an illumination unit 340 including a light source, a plurality of mirrors 321, 322, and 323, and a first frame 311 and a second frame that move in the sub-scanning direction X in an internal space 304 of the housing 306. A body 312, an imaging lens 357, a CCD 358 serving as a reading unit, and a CCD substrate 361 that performs predetermined processing on image information read by the CCD 358 and outputs the image information to the apparatus main body M side. Prepare. The illumination unit 340 and the first mirror 321 are accommodated in the first frame 311. The second mirror 322 and the third mirror 323 are accommodated in the second frame 312.

  The document conveyance unit 70 is connected to the reading unit 301 so as to be opened and closed by a connection unit (not shown). The document conveying unit 70 has a document placing unit 71 on the upper side, and a feed roller (not shown) inside. The document conveying unit 70 has a function of protecting the first reading surface 302A and the second reading surface 302B of the reading unit 301.

  The first reading surface 302 </ b> A is a reading surface used when reading the document G conveyed by the document conveying unit 70. First reading surface 302A is formed along the upper surface of first contact glass 335A on which document G is conveyed. The first reading surface 302A is located near the left side surface of the housing 306. Note that this position shown in FIG. 1 is also referred to as a “first reading position”.

The second reading surface 302 </ b> B is a reading surface used when reading the document G without using the document transport unit 70. The second reading surface 302B is formed along the upper surface of the second contact glass 335B on which the document G is placed. The second reading surface 302B is on the right side of the first reading surface 302A and extends over most of the sub-scanning direction X in the reading unit 301.
The first reading surface 302A and the second reading surface 302B extend in a direction orthogonal to the sub-scanning direction X and the main scanning direction Y.

  When reading the document G conveyed by the document conveyance unit 70, the document G is placed on the document placement unit 71. The document G placed on the document placement unit 71 is conveyed to the first reading surface 302 </ b> A of the reading unit 301 by the feed roller provided inside the document conveying unit 70. In this case, the first frame body 311 and the second frame body 312 are arranged at the first reading position and do not move. Then, the original G is conveyed by the original conveying unit 70 so as to slide on the first reading surface 302A, and an image formed on the surface of the original G is read by the CCD 358 as a reading device.

  Further, when the document conveying unit 70 is in an open state, the document G is placed on the second reading surface 302B. In this case, each of the first frame body 311 and the second frame body 312 moves in the sub-scanning direction X while keeping the length of an optical path H (optical path length) to be described later constant. Thereby, the image of the original G placed on the second reading surface 302B is read.

  In the internal space 304 of the housing 306, the plurality of mirrors 321, 322, and 323 form an optical path H for allowing light from the original G to enter the imaging lens 357. In addition, the first frame 311 moves at a constant speed A in the sub-scanning direction X, and the second frame 312 moves at a constant speed A / 2 in the sub-scanning direction X. The length of H is kept constant. Details of the reading unit 301 will be described later.

Next, the apparatus main body M will be described.
The main body M of the apparatus forms an image forming unit GK that forms a predetermined toner image on the paper T based on predetermined image information, and feeds the paper T to the image forming unit GK and discharges the paper T on which the toner image is formed. A paper supply / discharge unit KH for paper.
The outer shape of the apparatus main body M is configured by a case body BD as a casing.

  As shown in FIG. 1, the image forming unit GK includes photosensitive drums 2a, 2b, 2c, and 2d as image carriers (photosensitive members), charging units 10a, 10b, 10c, and 10d, and a laser as an exposure unit. Scanner units 4a, 4b, 4c, 4d, developing devices 16a, 16b, 16c, 16d, toner cartridges 5a, 5b, 5c, 5d, toner supply units 6a, 6b, 6c, 6d, drum cleaning unit 11a, 11b, 11c, 11d, static eliminators 12a, 12b, 12c, 12d, intermediate transfer belt 7, primary transfer rollers 37a, 37b, 37c, 37d, secondary transfer roller 8, counter roller 18, fixing Part 9.

  As shown in FIG. 1, the paper feed / discharge unit KH includes a paper feed cassette 52, a manual paper feed unit 64, a transport path L for paper T, a registration roller pair 80, a first paper discharge unit 50a, 2 paper discharge unit 50b. As will be described later, the transport path L includes a first transport path L1, a second transport path L2, a third transport path L3, a manual transport path La, a return transport path Lb, and a post-processing transport path Lc. Is a collection of

Hereinafter, each configuration of the image forming unit GK and the paper supply / discharge unit KH will be described in detail.
First, the image forming unit GK will be described.
In the image forming unit GK, charging by the charging units 10a, 10b, 10c, and 10d and laser scanner units 4a, 4b are sequentially performed from the upstream side to the downstream side with respect to the respective surfaces of the photosensitive drums 2a, 2b, 2c, and 2d. 4c, 4d exposure, development units 16a, 16b, 16c, 16d development, intermediate transfer belt 7 and primary transfer rollers 37a, 37b, 37c, 37d primary transfer, static eliminators 12a, 12b, 12c, 12d Static elimination and cleaning by the drum cleaning units 11a, 11b, 11c, and 11d are performed.
In the image forming unit GK, the secondary transfer by the intermediate transfer belt 7, the secondary transfer roller 8 and the counter roller 18, and the fixing by the fixing unit 9 are performed.

  Each of the photosensitive drums 2a, 2b, 2c, and 2d is formed of a cylindrical member and functions as a photosensitive member or an image carrier. Each of the photosensitive drums 2 a, 2 b, 2 c, and 2 d is disposed so as to be rotatable in the direction of an arrow about an axis that extends in a direction orthogonal to the traveling direction of the intermediate transfer belt 7. An electrostatic latent image can be formed on the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d.

  Each of the charging units 10a, 10b, 10c, and 10d is disposed to face the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d. Each of the charging units 10a, 10b, 10c, and 10d uniformly charges the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d negatively (minus polarity) or positively (plus polarity).

  The laser scanner units 4a, 4b, 4c, and 4d function as exposure units, and are spaced apart from the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d. Each of the laser scanner units 4a, 4b, 4c, and 4d includes a laser light source (not shown), a polygon mirror, a polygon mirror driving motor, and the like.

  Each of the laser scanner units 4a, 4b, 4c, and 4d scans and exposes the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d based on image information related to the image read by the reading unit 301. The scanning exposure is performed by each of the laser scanner units 4a, 4b, 4c, and 4d, thereby removing the charges on the exposed portions of the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d. Thereby, electrostatic latent images are formed on the respective surfaces of the photosensitive drums 2a, 2b, 2c, and 2d.

  The developing devices 16a, 16b, 16c, and 16d are provided corresponding to the photosensitive drums 2a, 2b, 2c, and 2d, respectively, and are disposed to face the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d. Each of the developing devices 16a, 16b, 16c, and 16d attaches the toner of each color to the electrostatic latent image formed on the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d, and converts the color toner image into the photosensitive drum. 2a, 2b, 2c and 2d are formed on the respective surfaces. Each of the developing devices 16a, 16b, 16c, and 16d corresponds to four colors of yellow, cyan, magenta, and black. Each of the developing devices 16a, 16b, 16c, and 16d includes a developing roller that can be disposed opposite to the surface of the photosensitive drums 2a, 2b, 2c, and 2d, a stirring roller for stirring the toner, and the like.

  Each of the toner cartridges 5a, 5b, 5c, and 5d is provided corresponding to each of the developing devices 16a, 16b, 16c, and 16d, and each color toner supplied to each of the developing devices 16a, 16b, 16c, and 16d. To accommodate. Each of the toner cartridges 5a, 5b, 5c, and 5d accommodates yellow toner, cyan toner, magenta toner, and black toner.

  The toner supply units 6a, 6b, 6c, and 6d are provided corresponding to the toner cartridges 5a, 5b, 5c, and 5d and the developing devices 16a, 16b, 16c, and 16d, respectively. The toners of the respective colors accommodated in 5d are supplied to the developing devices 16a, 16b, 16c, and 16d, respectively. Each of the toner supply units 6a, 6b, 6c, and 6d and each of the developing devices 16a, 16b, 16c, and 16d are connected by a toner supply path (not shown).

  To the intermediate transfer belt 7, the toner images of the respective colors formed on the photosensitive drums 2a, 2b, 2c, and 2d are sequentially primary-transferred. The intermediate transfer belt 7 is stretched around a driven roller 35, a counter roller 18 including a driving roller, a tension roller 36, and the like. Since the tension roller 36 biases the intermediate transfer belt 7 from the inside to the outside, a predetermined tension is applied to the intermediate transfer belt 7.

  Primary transfer rollers 37a, 37b, 37c, and 37d are arranged to face each other on the side opposite to the photosensitive drums 2a, 2b, 2c, and 2d with the intermediate transfer belt 7 interposed therebetween.

  A predetermined portion of the intermediate transfer belt 7 is sandwiched between the primary transfer rollers 37a, 37b, 37c, and 37d and the photosensitive drums 2a, 2b, 2c, and 2d, respectively. The predetermined portion thus sandwiched is pressed against the surface of each of the photosensitive drums 2a, 2b, 2c, and 2d. Primary transfer nips N1a, N1b, N1c, and N1d are formed between the photosensitive drums 2a, 2b, 2c, and 2d and the primary transfer rollers 37a, 37b, 37c, and 37d, respectively. In the primary transfer nips N1a, N1b, N1c, and N1d, the respective color toner images developed on the photosensitive drums 2a, 2b, 2c, and 2d are sequentially transferred to the intermediate transfer belt 7. As a result, a full-color toner image is formed on the intermediate transfer belt 7.

  The primary transfer rollers 37a, 37b, 37c, and 37d respectively transfer the color toner images formed on the photosensitive drums 2a, 2b, 2c, and 2d to the intermediate transfer belt 7 by a primary transfer bias applying unit (not shown). A primary transfer bias for transferring is applied.

  The static eliminators 12a, 12b, 12c, and 12d are arranged to face the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d, respectively. The static eliminators 12a, 12b, 12c, and 12d respectively irradiate the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d to irradiate light, and the photosensitive drums 2a, 2b, and 2c after the primary transfer is performed. 2d, each surface is neutralized (charge is removed).

  The drum cleaning units 11a, 11b, 11c, and 11d are disposed to face the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d, respectively. Each of the drum cleaning units 11a, 11b, 11c, and 11d removes toner and adhering matter remaining on the surfaces of the photosensitive drums 2a, 2b, 2c, and 2d, and conveys the removed toner to a predetermined recovery mechanism. And collect it.

  The secondary transfer roller 8 serving as a transfer unit secondarily transfers the toner image primarily transferred to the intermediate transfer belt 7 onto the paper T. A secondary transfer bias for transferring the full color toner image formed on the intermediate transfer belt 7 to the paper T is applied to the secondary transfer roller 8 by a secondary transfer bias applying unit (not shown).

  The secondary transfer roller 8 contacts or separates from the intermediate transfer belt 7. Specifically, the secondary transfer roller 8 is configured to be movable between a contact position where the secondary transfer roller 8 is in contact with the intermediate transfer belt 7 and a spaced position where the secondary transfer roller 8 is separated from the intermediate transfer belt 7. Specifically, the secondary transfer roller 8 is moved to the contact position when the toner image primarily transferred onto the surface of the intermediate transfer belt 7 is secondarily transferred to the paper T, and is separated from the other position. Moved to.

  On the opposite side of the intermediate transfer belt 7 from the secondary transfer roller 8, a counter roller 18 is disposed. A predetermined portion of the intermediate transfer belt 7 is sandwiched between the secondary transfer roller 8 and the opposing roller 18. Then, the paper T is pressed against the outer surface of the intermediate transfer belt 7 (the surface on which the toner image is primarily transferred). A secondary transfer nip N <b> 2 is formed between the secondary transfer roller 8 and the opposing roller 18. The toner image primarily transferred to the intermediate transfer belt 7 is secondarily transferred to the paper T in the secondary transfer nip N2.

  The fixing unit 9 melts and presses each color toner constituting the toner image secondarily transferred onto the paper T to fix it on the paper T. The fixing unit 9 includes a heating rotator 9a heated by a heater and a pressure rotator 9b pressed against the heating rotator 9a. The heating rotator 9a and the pressure rotator 9b sandwich and pressurize the paper T onto which the toner image has been secondarily transferred, and convey the paper T. By transporting the paper T while being sandwiched between the heating rotator 9a and the pressure rotator 9b, the toner transferred to the paper T is fixed to the paper T by being melted and pressurized. The

Next, the paper supply / discharge unit KH will be described.
As shown in FIG. 1, in the lower part of the apparatus main body M, two paper feed cassettes 52 that store paper T are arranged in an up-down direction. The paper feed cassette 52 is configured to be pulled out from the housing of the apparatus main body M in the horizontal direction. In the paper feed cassette 52, a placement plate 60 on which the paper T is placed is disposed. In the paper feed cassette 52, the paper T is stored in a state of being stacked on the placement plate 60. The paper T placed on the placement plate 60 is transported by the cassette paper feed unit 51 as a carry-in part disposed at the paper feed side end of the paper feed cassette 52 (left end in FIG. 1). Sent out. The cassette paper feed unit 51 includes a double feed prevention mechanism including a forward feed roller 61 for taking out the paper T on the placement plate 60 and a paper feed roller pair 63 for feeding the paper T to the transport path L one by one. Prepare.
In the case of the present embodiment, one of the two paper feed cassettes 52 constitutes a first storage unit, and the other constitutes a second storage unit. One sheet feed cassette 52 (first storage unit) stores sheet-like first paper T. The other paper feed cassette 52 (second storage section) stores second paper T that is sheet-like and shorter in the width direction than the first paper T. As an example, the first sheet T1 is an A4Y sheet. The second sheet is an A5T sheet.

  A manual paper feed unit 64 is provided on the right side surface (right side in FIG. 1) of the apparatus main body M. The manual paper feed unit 64 is provided mainly for supplying the apparatus main body M with a paper T of a size and type different from the paper T set in the paper feed cassette 52. The manual paper feed unit 64 includes a manual feed tray 65 that forms a part of the apparatus main body M in the closed state, and a paper feed roller 66. The lower end of the manual feed tray 65 is attached to the vicinity of the paper feed roller 66 so as to be rotatable (openable and closable). The paper T is placed on the open manual feed tray 65. The manual paper feed unit 64 feeds the paper T placed on the open manual feed tray 65 to the manual feed path La.

  A first paper discharge unit 50 a and a second paper discharge unit 50 b are provided on the upper side of the apparatus main body M. The first paper discharge unit 50a and the second paper discharge unit 50b discharge the paper T to the outside of the apparatus main body M. Details of the first paper discharge unit 50a and the second paper discharge unit 50b will be described later.

The transport path L transports the paper T (the first paper T and / or the second paper T) in a direction orthogonal to the width direction of the paper T.
The conveyance path L includes a first conveyance path L1 from the cassette paper feeding unit 51 to the secondary transfer nip N2, a second conveyance path L2 from the secondary transfer nip N2 to the fixing unit 9, and a first discharge from the fixing unit 9. The third conveyance path L3 to the paper section 50a, the manual conveyance path La that joins the paper supplied from the manual sheet feeding section 64 to the first conveyance path L1, and the third conveyance path L3 are conveyed from the upstream side to the downstream side. A reverse conveying path Lb for reversing the sheet to be reversed and returning it to the first conveying path L1, and a post-processing device connected to the second paper discharge unit 50b for conveying the third conveying path L3 from the upstream side to the downstream side ( And a post-processing conveyance path Lc for conveyance to a non-illustrated).

Moreover, the 1st junction part P1 and the 2nd junction part P2 are provided in the middle of the 1st conveyance path L1. A first branch portion Q1 is provided in the middle of the third transport path L3.
The first joining part P1 is a joining part where the manual feed path La joins the first transport path L1. The second junction P2 is a junction where the return conveyance path Lb merges with the first conveyance path L1.
The first branch portion Q1 is a branch portion where the post-processing transport path Lc branches from the third transport path L3. A rectifying member 58 is provided in the first branch portion Q1. The rectifying member 58 rectifies the transport direction of the paper T carried out from the fixing unit 9 to the third transport path L3 toward the first paper discharge section 50a or the post-processing transport path Lc toward the second paper discharge section 50b ( Switch).

  In the middle of the first transport path L1 (specifically, between the second joining portion P2 and the secondary transfer roller 8), a sensor for detecting the paper T and correction of the skew (oblique paper feeding) of the paper T In addition, a registration roller pair 80 for adjusting the timing with the toner image is disposed. The sensor is disposed immediately before the registration roller pair 80 in the transport direction of the paper T (upstream in the transport direction). The registration roller pair 80 is a pair of rollers that convey the paper T by performing the above-described correction and timing adjustment based on detection signal information from the sensor.

  The return conveyance path Lb is a conveyance provided to make the opposite surface (non-printing surface) to the surface of the photosensitive drums 2a, 2b, 2c, and 2d when performing double-sided printing on the paper T. Road. According to the return transport path Lb, the paper T transported from the first branching section Q1 to the paper discharge section 50 is turned upside down and returned to the first transport path L1 and arranged upstream of the secondary transfer roller 8. It can be conveyed to the upstream side of the pair of registration rollers 80. A predetermined toner image is transferred onto the non-printing surface by the photosensitive drums 2a, 2b, 2c, and 2d on the paper T that has been turned upside down by the return conveyance path Lb.

  A first paper discharge unit 50a is formed at the end of the third transport path L3. The first paper discharge unit 50 a is disposed on the upper side of the apparatus main body M. The first paper discharge unit 50a is open toward the right side surface of the apparatus main body M (the right side in FIG. 1, the manual paper feed unit 64 side). The first paper discharge unit 50a discharges the paper T transported through the third transport path L3 to the outside of the apparatus main body M.

  On the opening side of the first paper discharge section 50a, a paper discharge stacking section M1 is formed. The paper discharge stacking unit M1 is formed on the upper surface (outer surface) of the apparatus main body M. The paper discharge stacking unit M1 is a part formed by the upper surface of the apparatus main body M being depressed downward. The bottom surface of the paper discharge stacking unit M1 constitutes a part of the top surface of the apparatus main body M. In the paper discharge stacking unit M1, sheets T formed with a predetermined toner image and discharged from the first paper discharge unit 50a are stacked and stacked.

A second paper discharge unit 50b is formed at the end of the post-processing conveyance path Lc. The second paper discharge unit 50b is disposed on the upper side of the apparatus main body M. The second paper discharge section 50b opens toward the left side of the apparatus main body M (left side in FIG. 1, the side to which the post-processing apparatus is connected). The second paper discharge unit 50b discharges the paper T conveyed through the post-processing conveyance path Lc to the outside of the apparatus main body M.
A post-processing device (not shown) is connected to the opening side of the second paper discharge unit 50b. The post-processing device performs post-processing (stapling, punching, etc.) of paper ejected from the image forming apparatus (copy machine 1).
A paper detection sensor is disposed at a predetermined position on each conveyance path.

Next, a paper jam (JAM) in the main transport path L1 to L3 (the first transport path L1, the second transport path L2, and the third transport path L3 are collectively referred to as “main transport path” hereinafter) and the return transport path Lb. A structure for eliminating the problem will be briefly described.
As shown in FIG. 1, on the left side surface (left side in FIG. 1) of the apparatus main body M, main conveyance paths L1 to L3 and a return conveyance path Lb are arranged in parallel so as to mainly extend in the vertical direction. A cover body 40 is provided on the left side of the apparatus body M (left side in FIG. 1) so as to form a part of the side surface of the apparatus body M. The cover body 40 is connected to the apparatus main body M via a fulcrum shaft 43 at the lower end thereof. The fulcrum shaft 43 is disposed along the direction in which the axial direction crosses the main transport paths L1 to L3 and the return transport path Lb. The cover body 40 is configured to be rotatable between a closed position (position shown in FIG. 1) and an open position (not shown) with the fulcrum shaft 43 as a center.

  The cover body 40 includes a first cover portion 41 that is rotatably connected to the apparatus main body M by a fulcrum shaft 43, and a second cover portion 42 that is rotatably connected to the apparatus main body M by the same fulcrum shaft 43. It consists of and. The first cover portion 41 is located on the outer side (side surface side) of the apparatus main body M than the second cover portion 42. In FIG. 1, the hatched portion with the left-down dashed line is the first cover portion 41, and the hatched portion with the right-down dashed line is the second cover portion 42.

In the state where the cover body 40 is located at the closed position, the outer surface side of the first cover portion 41 forms a part of the outer surface (side surface) of the apparatus main body M.
Further, in the state where the cover body 40 is located at the closed position, the inner surface side (the apparatus main body M side) of the second cover portion 42 forms a part of the main transport paths L1 to L3.
Further, in a state where the cover body 40 is located at the closed position, the inner surface side of the first cover portion 41 and the outer surface side of the second cover portion 42 form at least a part of the return conveyance path Lb. That is, the return conveyance path Lb is formed between the first cover part 41 and the second cover part 42.

  The copying machine 1 of the present embodiment includes the cover body 40 having such a configuration, so that when a paper jam (JAM) occurs in the main transport paths L1 to L3, the cover body 40 is closed as shown in FIG. By rotating from the position to an open position (not shown) to open the main transport paths L1 to L3, it is possible to process paper jammed in the main transport paths L1 to L3. On the other hand, when a paper jam occurs in the return conveyance path Lb, the cover body 40 is rotated to the open position, and then the second cover portion 42 is moved to the apparatus main body M side (right side in FIG. ) To open the return conveyance path Lb, the paper jammed in the return conveyance path Lb can be processed.

  Next, the reading unit 301 of the image reading apparatus 300 will be described in detail with reference to FIGS. FIG. 2 is a plan view showing an outline of the internal structure of the reading unit 301 of the image reading apparatus 300. FIG. 3 is a diagram of the reading unit 301 of the image reading apparatus 300 viewed from the main scanning direction Y. FIG. 4 is a diagram showing an outline of the moving mechanism 370 of the illumination unit 347 and the mirror unit 349.

  As shown in FIGS. 2 and 3, the reading unit 301 includes a housing 306, a first contact glass 335A that forms a first reading surface 302A, a second contact glass 335B that forms a second reading surface 302B, Is provided. In addition, the reading unit 301 moves a pair of guide rails 345, an illumination unit 347, a mirror unit 349, and the pair of guide units that move the illumination unit 347 and the mirror unit 349 in the sub-scanning direction X in the internal space 304 of the housing 306. A unit moving mechanism 370, an imaging lens 357, a CCD 358 as a reading unit, and an optical sensor 362 are provided.

  The housing 306 has an opening corresponding to the first contact glass 335A and the second contact glass 335B on the upper side. This opening region is covered with the first contact glass 335A and the second contact glass 335B.

  As shown in FIG. 2, the pair of guide rails 345 are disposed between the right side surface 306 a and the left side surface 306 b along the main scanning direction Y in the housing 306. The pair of guide rails 345 are arranged so as to extend in the sub-scanning direction X from the front surface 306 c and the back surface 306 d along the sub-scanning direction X with an interval inside the main scanning direction Y. The pair of guide rails 345 are installed in parallel with the first contact glass 335A and the second contact glass 335B. On the pair of guide rails 345, the first frame 311 of the illumination unit 347 and the second frame 312 of the mirror unit 349 are mounted so as to be movable in the sub-scanning direction X.

As shown in FIG. 2, the pair of unit moving mechanisms 370 are respectively provided between the front surface 306c of the housing 306 and one guide rail 345 and between the other guide rail 345 of the back surface 306d of the housing 306. Be placed. The pair of unit moving mechanisms 370 are configured line-symmetrically in the main scanning direction Y.
Details of the unit moving mechanism 370 will be described later.

  As illustrated in FIG. 3, the illumination unit 347 includes an illumination unit 340, a first mirror 321, and a first frame 311 that houses the illumination unit 340 and the first mirror 321.

  The illumination unit 340 includes an LED unit to which a plurality of LEDs 501 are attached. The illumination unit 340 irradiates the document reading position R with light H0. The first mirror 321 is disposed on the lower side in the vertical direction Z of the illumination unit 347. The first mirror 321 is arranged so that the reflection surface faces the document G and the second mirror 322 side. The first mirror 321 reflects the light beam H 1 from the document to the second mirror 322.

  As shown in FIG. 3, the mirror unit 349 includes a second mirror 322, a third mirror 323, and a second frame 312 that accommodates the second mirror 322 and the third mirror 323.

  The second mirror 322 is disposed on the upper side in the vertical direction Z of the second frame 312. The second mirror 322 is arranged so that the reflection surface faces the first mirror 321 and the third mirror 323 side. The second mirror 322 reflects the light beam H2 from the first mirror 321 to the third mirror 323 side.

  The third mirror 323 is disposed on the lower side in the vertical direction Z of the second frame 312. The third mirror 323 is arranged so that the reflection surface faces the second mirror 322 and the imaging lens 357 side. The third mirror 323 reflects the light beam H3 from the second mirror 322 to the imaging lens 357 side.

  As shown in FIGS. 2 and 3, an ISU base 356 that is a member that supports the imaging lens 357, the CCD 358, and the like is attached to the bottom surface 306e of the housing 306 near the right side surface 306a. An imaging lens 357 and a CCD 358 as a reading unit are attached to the upper surface of the ISU base 356 in a predetermined positional relationship.

  The imaging lens 357 is installed on a lens support 359 that is fixed to the ISU base 356. The lens support base 359 is disposed such that its position can be adjusted by a guide member 360 disposed on the CCD 358 side. The imaging lens 357 is disposed at the approximate center in the main scanning direction Y of the reading unit 301. The imaging lens 357 is disposed on the end side opposite to the original G side in the optical path H. The imaging lens 357 forms an image of the incident light beam H4 at a predetermined position. That is, the imaging lens 357 forms an image of the original G at a predetermined position.

  The CCD 358 is mounted on a CCD substrate 361 disposed on the back side of the guide member 360. The CCD 358 is disposed at an image forming position in the image forming lens 357. The light beam from the imaging lens 357 is incident on the CCD 358 through the opening window 360 a formed near the center of the guide member 360. The optical axis of the light beam incident on the CCD 358 is corrected by finely adjusting the position of the guide member 360.

  The optical sensor 362 is disposed on the ISU base 356. The optical sensor 362 detects the size of the document G along the sub-scanning direction X depending on whether or not the reflected light from the document G placed on the second contact glass 335B is received.

Next, the unit moving mechanism 370 will be described in detail.
2 and 4, the unit moving mechanism 370 includes a driving wire 371, a first fixed member 372, a first connecting member 373, a first movable pulley 374, a second connecting member 375, The first fixed pulley 376, the drive pulley 377, the second fixed pulley 378, the second movable pulley 379, the third fixed pulley 380, the elastic member 381, and the second fixed member 382 are provided.

  The fixing members 372 and 382 are fixed to the bottom surface 306e of the housing 306. The movable pulleys 374 and 379 are fixed to the first frame 311 of the mirror unit 349 so that the rotation axis extends in the main scanning direction Y. The pulleys 376, 377, and 378 are fixed to the housing 306 so that the rotation shaft extends in the main scanning direction Y. The third fixed pulley 380 is fixed to the housing 306 so that the rotation axis extends in the vertical direction Z.

  One end of the driving wire 371 is connected to the first fixing member 372 by the first connecting member 373. The other end of the drive wire 371 is connected to the second fixing member 382 through an elastic member 381. An intermediate portion of the driving wire 371 is connected to the first frame 311 of the lighting unit 347 by the second connecting member 375 and is also stretched over each movable pulley and each fixed pulley. The drive wire 371 is driven by a drive pulley 377.

  The first fixed pulley 376 is disposed in the vicinity of the right side surface 306 a of the housing 306. The second fixed pulley 378 is disposed in the vicinity of the left side surface 306 b of the housing 306. The third fixed pulley 380 is disposed in the vicinity of the left side surface 306 b of the housing 306. The first fixing member 372 is disposed between the first fixed pulley 376 and the second fixed pulley 378 in the sub scanning direction X. The first connecting member 373 connects one end of the driving wire 371 and the first fixing member 372. The second fixing member 382 is disposed on the inner side in the main scanning direction Y than the third fixing pulley 380. The elastic member 381 connects the end of the drive wire 371 and the third fixed pulley 380 so that an elastic force appears in the main scanning direction Y.

The first movable pulley 374 and the second movable pulley 379 are fixed outside the main scanning direction Y in the second frame 312 of the mirror unit 349. The first movable pulley 374 and the second movable pulley 379 are disposed between the first fixed pulley 376 and the second fixed pulley 378 and the third fixed pulley 380 in the sub-scanning direction X.
The second connecting member 375 is provided on the first frame 311 of the lighting unit 347 and connects the first frame 311 and the drive wire 371. The second connecting member 375 is disposed between the first fixed pulley 376 and the first movable pulley 374 and the second movable pulley 379.

  The drive wire 371 is spanned as follows. Specifically, one end of the driving wire 371 is connected to the first fixing member 372 by the first connecting member 373, extends to the left side 306b side of the housing 306, and from the lower side to the left of the first movable pulley 374. It is hung on the half circumferential surface, extends from the upper side of the first movable pulley 374 to the right side surface 306a side of the housing 306, and is connected to the first frame 311 by the second connecting member 375. The drive wire 371 extends from the first frame 311 to the right side 306a side of the housing 306, is hung from the upper side to the right half circumferential surface of the first fixed pulley 376, and from the lower side of the first fixed pulley 376. It extends to the left side 306b side of the body 306 and is hung from the lower side on the left half circumferential surface of the second fixed pulley 378. The drive wire 371 extends from the upper side of the second fixed pulley 378 to the right side surface 306 a, is hung from the lower side on the right half circumferential surface of the second movable pulley 379, and the housing 306 from the upper side of the second movable pulley 379. Extends to the left side surface 306b side, is hung on the third fixed pulley 380, and extends inward in the main scanning direction Y. Furthermore, the other end of the drive wire 371 is connected to the second fixing member 382 via an elastic member 381.

  In the pair of unit moving mechanisms 370, the respective drive pulleys 377 are connected by a drive shaft 383 extending in the main scanning direction Y. One drive pulley 377 is driven forward or reverse by a drive motor (not shown). Thus, when one drive pulley 377 rotates, the other drive pulley 377 also rotates in synchronization with this rotation.

  As the driving pulley 377 rotates, the driving wire 371 moves in the sub-scanning direction X toward the right side 306a or the left side 306b of the housing 306. As the driving wire 371 moves, the illumination unit 347 and the mirror unit 349 move in the sub-scanning direction X along the guide rail 345. The illumination unit 347 (first frame 311) is connected to the drive wire 371, whereas the mirror unit 349 includes a first movable pulley 374 that is a movable pulley provided on the second frame 312 and A drive wire 371 is stretched over the second movable pulley 379. Therefore, the ratio of the moving distance of the illumination unit 347 and the moving distance of the mirror unit 349 is 2: 1.

  In the present embodiment, a configuration in which the ratio between the moving distance of the illumination unit 347 and the moving distance of the mirror unit 349 is 2: 1 is realized using the principle of a moving pulley. Not. For example, a configuration in which the ratio of the moving distance of the illumination unit 347 and the moving distance of the mirror unit 349 is 2: 1 can be realized by using a driving pulley and a driven pulley having a large diameter portion and a small diameter portion.

  Next, the characteristic part of the copier 1 according to the present embodiment will be described in detail with reference to FIGS. FIG. 5 is a functional block diagram for explaining the function of the characteristic part in the copying machine 1. FIG. 6 is a flowchart for explaining the operation of the copying machine 1. FIG. 7 is a diagram for explaining the order of passing the paper T and the temperature of the fixing unit 9.

As shown in FIG. 5, the copier 1 includes a receiving unit 101, a cassette paper feeding unit 51 as a carry-in unit, and a control unit 102.
The receiving unit 101 can receive image formation instruction information including at least type information regarding the type of paper T on which an image is to be formed and sheet number information regarding the number of sheets T.
The cassette paper feeding unit 51 selectively carries the first paper T stored in one paper feeding cassette 52 and the second paper T stored in the other paper feeding cassette 52 into the transport path L.

The control unit 102 alternately performs a process of continuously carrying a predetermined number of first sheets T into the transport path L and a process of continuously transporting a predetermined number of second sheets T into the transport path L. The cassette paper feeding unit 51 is controlled. The control unit 102 performs such control on the cassette paper feeding unit 51 with image formation instruction information including type information that sets the paper T as the first paper T and number information that sets the number of the first paper T to a predetermined number or more. This is performed when the receiving unit 101 receives the type information for setting the paper T as the second paper T and the image forming information including the number information for making the number of the second paper T equal to or larger than the predetermined number within a predetermined time. . In addition, the time measuring part 104 mentioned later performs time measurement of predetermined time.
The control unit 102 can control the cassette paper feeding unit 51 to perform the process of continuously carrying a predetermined number of first sheets T into the transport path L first.

  In addition, the control unit 102 controls the cassette paper feeding unit 51 so that the first paper T is carried into the transport path L before the second paper T. The control unit 102 controls the cassette paper feeding unit 51 in such a manner as to include image formation instruction information including type information for the paper T as the first paper T and an image including type information for the paper T as the second paper T. It can also be performed when the receiving unit 101 continuously receives the formation information within a predetermined time.

Further, the copier 1 may include a display unit 103, a display control unit 104, a time measuring unit 105, and an instruction unit 106.
The display unit 103 performs a process of continuously carrying a predetermined number of first sheets T into the conveyance path L and a process of continuously carrying a predetermined number of second sheets T into the conveyance path L by the cassette sheet feeding unit 51. Is performed alternately, a predetermined notification display is performed. The predetermined notification display is a display indicating that a predetermined number of first sheets T and a predetermined number of second sheets T are alternately carried into the conveyance path L. For example, the display unit 103 may perform a predetermined notification display at a predetermined location on the display screen. Further, when the display unit 103 is formed of a light emitting element such as a light emitting diode, the display unit 103 may emit light as a predetermined notification display.
The display control unit 104 causes the display unit 103 to display a predetermined notification display.

The timing unit 105 counts time when the receiving unit 101 receives image formation information.
In addition, the timing unit 105 alternately performs a process of continuously carrying a predetermined number of first sheets T into the transport path L and a process of continuously transporting a predetermined number of second sheets T into the transport path L. In case of failure, measure the time.
In this case, the display control unit 104 controls the display unit 103 to turn off the predetermined notification display displayed on the display unit 103 when the time measured by the time measuring unit 105 has elapsed for a predetermined time.

The instruction unit 106 outputs erasure instruction information for erasing a predetermined notification display displayed on the display unit 103. The instruction unit 106 may be, for example, a button arranged outside the copier 1 or a button displayed at a predetermined location on the touch panel arranged in the copier 1.
In this case, the display control unit 104 controls the display unit 103 to erase a predetermined notification display displayed on the display unit 103 based on the erasure instruction information output from the erasure instruction unit 106.

Next, the operation of the copier 1 will be described with reference to FIG.
First, a plurality of documents G having different paper sizes are placed on, for example, the document placement unit 71. In the present embodiment, the plurality of documents G includes a plurality of large-size documents and a plurality of small-size documents having different paper sizes. As a specific example, the plurality of documents G includes a plurality of A4Y documents and a plurality of A5T documents.

  In step ST <b> 1, the receiving unit 101 detects print execution information that is generated when an unillustrated image formation execution button (start button) disposed outside the copier 1 is pressed, for example.

  In step ST <b> 2, the receiving unit 101 conveys a plurality of documents G by driving a feed roller (not shown) arranged inside the document transport unit 70 and causes the reading unit 301 to read the plurality of documents G. At this time, the paper size of the original G is detected. When the document G is placed on the second reading surface 302B and continuously read by the reading unit 301, the size of the document G is detected by the optical sensor 362.

  Next, the control unit 102 determines the order in which the first paper T and the second paper T are carried into the transport path L. Specifically, in step ST3, the control unit 102 determines that the number of sheets to be printed on the small-size paper T (second paper T) based on the small-size document is less than a set number (for example, 5) that is a threshold value. Determine whether or not. If the number of sheets to be printed on the second sheet T is less than the set number (Yes), the process proceeds to step ST4. If the number of sheets to be printed on the second sheet T is greater than or equal to the set number (No), the process proceeds to step ST5.

  In step ST4, the control unit 102 prints a predetermined number of large sized papers T (first paper T) based on a large sized original, and then prints a predetermined number of small sized papers based on the small sized original. All the paper T (second paper T) is printed. Specifically, first, the control unit 102 controls the cassette paper feeding unit 51 so that the first paper T stored in one cassette paper feeding unit 51 is carried into the transport path L. The first paper T is passed between the secondary transfer roller 8 and the opposing roller 18 via the conveyance path L, and a toner image based on a large-size document is secondarily transferred. Further, the first paper T is passed through the fixing unit 9. The fixing unit 9 fixes the toner image on the first paper T by heating the toner image transferred to the first paper T and melting the toner image. The control unit 102 carries the first sheet T into the conveyance path L until all the predetermined number of first sheets T are printed based on a plurality of large-size documents. At this time, the first sheet T is passed so that the sheet interval (the interval between the preceding sheet and the succeeding sheet) is minimized.

  Next, the control unit 102 controls the cassette paper feeding unit 51 so that the second paper T stored in the other cassette paper feeding unit 51 is carried into the transport path L. Note that the transport, transfer, and fixing operations for the second paper T are the same as those for the first paper T, and a description thereof will be omitted. The second paper T is passed so that the paper gap is minimized. Further, the second paper T is passed so that the gap between the first paper T and the first paper T is minimized. That is, if only a predetermined number of second sheets T, which are less than the set number, are passed through the fixing unit 9, the temperature difference generated between the central portion and both ends in the width direction of the heating rotator 9a is small. The second paper T can be passed through the same paper space (minimum paper space) as the paper when the first paper T is passed.

  Next, in step ST5, the control unit 102 sets the number of sheets to be printed on the first sheet T based on a large-size document and the number of sheets to be printed on the second sheet T based on a small-size document (each set number). For example, it is determined whether or not the number is 5 or more. If the number of sheets to be printed on the first sheet T and the second sheet T is greater than or equal to the set number (Yes), the process proceeds to step ST6. If the number of sheets printed on the first sheet T and the second sheet T is not more than the set number (if the number printed on the first sheet T is less than the set number) (No), the process proceeds to step ST7.

  In step ST <b> 6, the control unit 102 loads a predetermined number (for example, four sheets) of the first sheet T, which is less than the set number, into the transport path L from one sheet feeding cassette 52, and sets the predetermined number of sheets, which is less than the set number. The cassette paper feeding unit 51 is controlled so as to alternately carry (for example, four sheets) the second paper T from the other paper feeding cassette 52 into the transport path L. As a result, the first sheet T and the second sheet T are alternately passed between the secondary transfer roller 8 and the opposing roller 18 by a predetermined number. Accordingly, a predetermined number of first sheets T and second sheets T are alternately passed between the secondary transfer roller 8 and the opposing roller 18. In this case, the gap between the first sheets and the gap between the second sheets are minimized. Further, the second paper T is passed so that the gap between the first paper T and the first paper T is minimized. Further, the first paper T is passed so that the gap between the first paper T and the second paper T is minimized. Details of the operation in step ST6 will be described later.

  In step ST <b> 7, the control unit 102 causes the first paper T to be carried into the transport path L from one paper feed cassette 52 and then the second paper T to be carried into the transport path L from the other paper feed cassette 52. The paper feed unit 51 is controlled. That is, the copier 1 prints the first sheet T based on a large-size document, and then prints the second sheet T based on a small-size document. Note that the transport, transfer, and fixing operations for the first sheet T and the second sheet T are the same as the operations described in step S4, and thus description thereof is omitted. In this case, the first paper T is passed so that the paper gap is minimized. Further, the second paper T is passed so as to have a gap between the sheets suitable for passing through the fixing unit 9.

  Here, in the case where the set number or more of the second sheets T are continuously passed through the fixing unit 9 between the minimum sheets, the temperature of the central portion (sheet passing region) in the width direction of the heating rotator 9a decreases. The temperature at both ends (sheet non-passing area) rises. Therefore, in step ST7, when the second sheet T is passed through the fixing unit 9, the gap between the second sheets T is set larger than the gap between the first sheets T. Thereby, the heating rotator 9a raises the temperature of the central portion due to the large space between the second sheets. That is, in the copying machine 1, the control unit 102 controls the cassette sheet feeding unit 51 so that the space between the second sheets T is larger than the space between the first sheets T, whereby the width of the heating rotator 9a is increased. The temperature in the direction is made uniform.

  Note that when the predetermined number of sheets of the first sheet T and the second sheet T are alternately printed in step ST6, the display unit 103 performs a predetermined notification display. In this case, the timing unit 105 starts timing from when the first sheet T and the second sheet T are discharged to the first sheet discharge unit 50a or the second sheet discharge unit 50b, for example. Then, the time measuring unit 105 outputs time information to the control unit 102 after the predetermined time has elapsed. Further, when the timekeeping information is supplied, the control unit 102 outputs the timekeeping information to the display control unit 104. When the timing information is supplied, the display control unit 104 controls the display unit 103 to turn off the predetermined notification display displayed on the display unit 103.

  Further, when the display unit 103 performs a predetermined notification display, the instruction unit 106 outputs erasure instruction information to the control unit 102 when a predetermined operation such as being pressed by the user is performed. Further, when the erasure instruction information is supplied, the control unit 102 outputs the erasure instruction information to the display control unit 104. When the erasure instruction information is supplied, the display control unit 104 controls the display unit 103 to erase a predetermined notification display displayed on the display unit 103.

Next, details of the operation in step ST6 will be described with reference to FIG.
In step ST6, as described above, the first step of printing a predetermined number (for example, four sheets) of first sheets T and the second step of printing a predetermined number (for example, four sheets) of second sheets T are repeatedly performed. As a result, all of the large-size original and the small-size original read by the reading unit 301 are printed.

  First, in the first process, after the first paper T (for example, A4Y) is carried into the transport path L from one paper feed cassette 52 by the cassette paper feeding unit 51, the first paper T is opposed to the secondary transfer roller 8. Paper is passed between the rollers 18. The secondary transfer roller 8 and the counter roller 18 transfer the toner image based on the large-size document read by the reading unit 301 onto the first sheet T. Next, the first sheet T is passed through the fixing unit 9. The fixing unit 9 fixes the toner image on the first paper T by sandwiching the first paper T between the heating rotator 9a and the pressure rotator 9b to melt and press the toner image. At this time, the first paper T passes through the entire width direction of the heating rotator 9a and the pressure rotator 9b. For this reason, since the temperature in the entire width direction of the heating rotator 9a is uniformly reduced, the number of first sheets T less than the set number can be supplied to the fixing unit 9 with a minimum number of sheets.

  Next, in the second step, after the second paper T (for example, A5T) is carried into the transport path L from the other paper feed cassette 52 by the cassette paper feeding unit 51, the second paper T is brought into contact with the secondary transfer roller 8. Paper is passed between the opposing rollers 18. The secondary transfer roller 8 and the counter roller 18 transfer the toner image based on the small-size original read by the reading unit 301 onto the second paper T. Next, the second paper T is passed through the fixing unit 9. The fixing unit 9 fixes the toner image on the second paper T by sandwiching the second paper T between the heating rotator 9a and the pressure rotator 9b to melt and press the toner image. At this time, the second paper T passes through the central portion in the width direction of the heating rotator 9a. For this reason, in the heating rotator 9a, when the second paper T is passed, the temperature of the central portion (paper passage region) in the width direction decreases and the temperature of both ends (paper non-passage region) increases. As a specific example, as shown in FIG. 7, the temperature of the heating rotator 9a is about 180 ° C. when four A5T sheets T are passed through the fixing unit 9, and the sheet non-passing state. The region becomes 190 ° C. Thus, only by passing a predetermined number of sheets (for example, four sheets) of the second sheet T through the fixing unit 9, the temperature difference generated between the central part and both ends of the heating rotator 9a is small. The second paper T can be passed with the same paper spacing (minimum paper spacing) as the paper T is passed.

  Next, in the third step, as in the first step, the first sheet T is passed through the transfer portion (secondary transfer roller 8 and counter roller 18) and the fixing portion 9 in this order. The first sheet T passes through the entire width direction of the heating rotator 9a and the pressure rotator 9b in the fixing unit 9. For this reason, even if temperature variation occurs in the width direction of the heating rotator 9a in the second step, as shown in FIG. 7, the first sheet T less than the set number (for example, four sheets) is passed. As a result, the temperature of the entire surface of the heating rotator 9a in the width direction is uniformly reduced, so that the first sheet T can be passed through the fixing unit 9 between the minimum sheets.

  Next, in the fourth step, as in the second step, the second sheet T is passed through the transfer portion (secondary transfer roller 8 and counter roller 18) and the fixing portion 9 in this order. Even in this case, only by passing a predetermined number (for example, four sheets) of the second sheet T through the fixing unit 9, as in the second step, the central portion (sheet passing region) and both end portions ( Since the temperature difference generated between the first paper T and the first paper T is small, the second paper T can be passed through the same paper space (minimum paper space) as the first paper T is passed. .

  In the subsequent steps, the same steps as the first step and the second step are repeated to print all of the large-size document and the small-size document read by the reading unit 301.

Next, examples will be described.
That is, the time required for printing when the paper T is printed using the copying machine 1 according to the present embodiment and the conventional copying machine according to the comparative example is compared.

First, a conventional copying machine according to a comparative example will be described. As shown in Table 1, in the conventional copying machine, as the width of the paper becomes narrower, the interval between the sheets to be passed becomes longer, and the number of pages printed per minute (ppm) decreases.

  When the A4Y paper is passed through the fixing unit, the A4Y paper passes through the entire width of the heating rotator, so the temperature in the width direction becomes uniform. Therefore, even when A4Y paper is continuously passed through the fixing unit, the temperature in the width direction of the heating rotator becomes uniform.

  On the other hand, when narrow size paper (A4T (A4 length), A5T and A6T (A6 length)) narrower than the A4Y paper is passed through the fixing portion, the heating rotator is narrower in the center in the width direction. Since the size paper passes, the temperature of the central portion (paper passage region) decreases and the temperature of both end portions (paper non-passage region) in the width direction increases. For this reason, when narrow-size paper is continuously passed through the fixing unit while narrowing the gap between the sheets, the temperature of the central portion in the width direction of the heating rotator becomes lower than both ends. In order to prevent such a temperature in the width direction of the heating rotator from becoming non-uniform, in a conventional copying machine, the space between papers is increased as the width of the sheet is reduced, and the heating rotator is increased. The temperature of the central portion of the sheet (the sheet passage area of narrow-size sheets) is raised, and the temperature in the width direction of the heating rotator is made uniform until the next sheet is passed.

  In the conventional copying machine, when printing is performed by sequentially passing 16 sheets of A4Y paper and A5T paper in this order, the A4Y paper and the A5T paper are separated according to the sheet spacing shown in Table 1, respectively. Since the paper is passed, the printing time takes 1 minute 30 seconds.

  On the other hand, when the copier 1 according to this embodiment prints 16 sheets of A4Y paper T and 16 sheets of A5T paper, respectively, the A5T paper is printed after printing 4 sheets of A4Y paper T as described above. Repeat printing 4 sheets of T 4 times. At this time, the A5T paper is passed through the same paper as the A4Y paper. That is, as shown in Table 1, the copier 1 prints the A4Y paper T at 32 [ppm], and prints the A5T paper T at 32 [ppm], which is the same as the A4Y paper T. Therefore, the copying machine 1 requires only 1 minute to print.

According to the copying machine 1 of the present embodiment as described above, the following effects are produced.
According to the present embodiment, the copying machine 1 includes one sheet feeding cassette 52 that stores the first sheet T and the other that stores the second sheet T that is shorter in the width direction than the first sheet T. Paper feeding cassette 52, the first paper T stored in one paper feeding cassette 52, and the second paper T stored in the other paper feeding cassette 52 are selectively fed into the transport path L. A paper unit 51; a receiving unit 101 capable of receiving image formation instruction information including at least type information relating to a type of paper T on which an image is formed; and number information relating to the number of papers T; Image forming instruction information including the type information to be used and the number information of the first paper T to be a predetermined number or more, the type information to be the paper T as the second paper T, and the number of the second paper T to be a predetermined number or more. Image formation information including When the attaching unit 101 receives continuously within a predetermined time, a process of continuously carrying a predetermined number of first sheets T into the conveyance path L and a predetermined number of second sheets T being continuously input to the conveyance path L. And a control unit 102 that controls the cassette paper feeding unit 51 so that the carrying-in process is alternately performed.
Therefore, the copying machine 1 passes a predetermined number of second sheets T through the fixing unit 9, so that a temperature difference generated between a sheet passing area and a sheet non-passing area in the heating rotator 9 a constituting the fixing unit 9. Can be reduced. As a result, the copying machine 1 can pass a predetermined number of second sheets T between the same minimum number of sheets as when the first sheet T is passed, thereby shortening the printing time. it can.

Further, according to the present embodiment, the copying machine 1 continuously carries a predetermined number of first sheets T into the conveyance path L and continuously carries a predetermined number of second sheets T into the conveyance path L. When the process to be performed is alternately performed, the display unit 103 performs a predetermined notification display.
Therefore, the copier 1 can alert the user that the predetermined number of first sheets T and the predetermined number of second sheets T are alternately discharged.

Further, according to the present embodiment, the copying machine 1 stores one paper feed cassette 52 that stores the first paper T and the second paper T that is shorter in the width direction than the first paper T. The other paper feed cassette 52, the first paper T stored in one paper feed cassette 52, and the second paper T stored in the other paper feed cassette 52 are selectively carried into the transport path L. A cassette paper feed unit 51 for receiving, an accepting unit 101 capable of accepting image formation instruction information including at least type information relating to the type of paper T on which an image is to be formed, and number information relating to the number of paper T, and a paper T When the receiving unit 101 continuously receives image formation instruction information including type information for the first sheet T and image formation information including type information for the second sheet T as the first sheet T, the first Transport paper T before second paper T A control unit 102 for controlling the feed cassette 51 so as to carry the L, and configured to include.
Therefore, the copying machine 1 can prevent the problem of high temperature offset in the first paper T. As a result, the copying machine 1 can pass a predetermined number of second sheets T between the same minimum number of sheets as when the first sheet T is passed, thereby shortening the printing time. it can.

As mentioned above, this invention is not limited to this embodiment, It can implement with a various form.
In the present embodiment, the case where the first sheet T is an A4Y sheet and the second sheet T is an A5T sheet has been described. However, the present invention is not limited to this. That is, the second sheet only needs to have a predetermined width shorter than that of the first sheet. For example, the first sheet may be an A4Y sheet and the second sheet may be an A6T sheet. The first sheet may be an A4Y sheet, and the second sheet may be an A4T sheet. Further, the first sheet may be an A5T sheet, and the second sheet may be an A6T sheet.

  In the present embodiment, when the first paper T and the second paper T are alternately carried into the conveyance path L by the cassette paper feeding unit 51, the first paper T is first conveyed to the conveyance path L, and then Although the form which carries in the 2nd paper T to the conveyance path L was demonstrated, it is not limited to this. That is, the control unit 102 controls the cassette paper feeding unit 51 to first carry a predetermined number of second sheets T, which is less than the set number, into the transport path L, and then to the predetermined number of sheets, which is less than the set number. Carrying in one sheet T into the transport path L may be repeated.

  In this embodiment, the case where each of the first paper T and the second paper T is stored in the paper feed cassette 52 has been described. However, the present invention is not limited to this. That is, one of the first paper T and the second paper T may be placed on the manual paper feed unit 64.

  In this embodiment, the toner image is transferred onto the paper T via the intermediate transfer belt 7 (indirect transfer method). However, the present invention is not limited to this, and the toner image is directly transferred onto the paper T without passing through the intermediate transfer belt. It is also possible to transfer a toner image (direct transfer method).

In addition, the sheet-shaped transfer material is the paper T in the present embodiment, but is not limited thereto, and may be, for example, a film sheet.
In this embodiment, the copying machine 1 is described as an image forming apparatus. However, a printer, a facsimile, a complex machine of these, or the like may be used. When the image forming apparatus is a printer, the image forming instruction information received by the receiving unit 101 is generated by a personal computer connected to the printer.

DESCRIPTION OF SYMBOLS 1 ... Copy machine (image forming apparatus), 8 ... Secondary transfer roller, 18 ... Counter roller, 51 ... Cassette paper feeding part, 52 ... Paper feeding cassette, 101 ... Reception part, 102 ... Control , 103 ... Display unit, 104 ... Display control unit, 105 ... Timekeeping unit, 106 ... Instruction unit

Claims (6)

A first storage portion in which a sheet-shaped first transfer material is stored;
A second storage portion for storing a second transfer material that is in the form of a sheet and is shorter in the width direction than the first transfer material;
A transport path for transporting the first transfer material and / or the second transfer material in a direction orthogonal to the width direction;
An image carrier on which an electrostatic latent image is formed on the surface;
A developing device for developing a toner image on the electrostatic latent image formed on the image carrier;
A transfer unit that directly or indirectly transfers a toner image formed on the image carrier to the first transfer material and the second transfer material conveyed by the conveyance path;
The first transferred material and the second transferred material are heated by melting the toner image by heating the toner image transferred to the first transferred material and the second transferred material by the transfer unit. A fixing unit for fixing the toner image on a material;
A carry-in unit that selectively carries the first transfer material stored in the first storage unit and the second transfer material stored in the second storage unit into the transfer path;
A receiving unit capable of receiving image formation instruction information including at least type information relating to a type of a transfer material on which an image is formed and number information relating to the number of transfer materials;
Type information in which the material to be transferred is a first material to be transferred, image formation instruction information including information on the number of the first material to be transferred is a predetermined number or more, and a type in which the material to be transferred is a second material to be transferred When the receiving unit continuously receives information and image formation information including the number information of the second transferred material equal to or greater than a predetermined number, within a predetermined time,
The carry-in unit that alternately performs a process of continuously carrying a predetermined number of first transfer materials into the transport path and a process of continuously carrying a predetermined number of second transfer materials into the transport path. A control unit that controls the image forming apparatus. The control unit includes an image including, within a predetermined time, image formation instruction information including type information in which the receiving unit sets the transfer material as the first transfer material, and type information including the transfer material as the second transfer material. 3. The image forming apparatus according to claim 2, wherein when receiving the formation information, the carry-in unit is controlled so that the predetermined number of first transfer target materials are successively carried into the conveyance path. A process of continuously carrying a predetermined number of first transfer materials into the conveyance path and a process of continuously carrying a predetermined number of second transfer materials into the conveyance path are alternately performed by the carry-in unit. 4. The image forming apparatus according to claim 2, further comprising a display unit that performs predetermined notification display in the case of failure. The image forming apparatus according to claim 4, further comprising a display control unit that controls the display unit to turn off the predetermined notification display after a predetermined time has elapsed. An erasure instruction unit for outputting erasure instruction information for erasing the predetermined notification display displayed on the display unit;
The image forming apparatus according to claim 4, further comprising: a display control unit that controls the display unit to erase the predetermined notification display based on the erasure instruction information output from the erasure instruction unit. A first storage portion in which a sheet-shaped first transfer material is stored;
A second storage portion for storing a second transfer material that is sheet-like and shorter in the width direction than the first transfer material;
A transport path for transporting the first transfer material and / or the second transfer material in a direction orthogonal to the width direction;
An image carrier on which an electrostatic latent image is formed on the surface;
A developing device for developing a toner image on the electrostatic latent image formed on the image carrier;
A transfer unit that directly or indirectly transfers the toner image formed on the image carrier to the first transfer material and / or the second transfer material conveyed by the conveyance path;
The first transferred material and the second transferred material are heated by melting the toner image by heating the toner image transferred to the first transferred material and the second transferred material by the transfer unit. A fixing unit for fixing the toner image on a material;
A carry-in unit that selectively carries the first transfer material stored in the first storage unit and the second transfer material stored in the second storage unit into the transfer path;
A receiving unit capable of receiving image formation instruction information including at least type information relating to a type of a transfer material on which an image is formed and number information relating to the number of transfer materials;
The receiving unit continuously receives, within a predetermined time, image formation instruction information including type information for a transfer material as a first transfer material and image formation information including type information for a transfer material as a second transfer material. And a control unit that controls the carry-in unit so that the first transfer material is carried into the conveyance path before the second transfer material.

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