JP2012078604A - Medium carrying device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate removing work of a medium remaining in a carrying path.SOLUTION: A medium carrying device (BHS) comprises: a carrying path (SH) of a medium (S); carrying members (Rp-Ra) of the medium (S); first guiding portions (11 and 16) capable of guiding the medium (S); second guiding portions (12 and 17) which oppose to the first guiding portions (11 and 16), and can move between a carrying position capable of carrying the medium (S) and an opening position opening the carrying path (SH); opening detection means (C18) for detecting whether the carrying path (SH) is opened; remaining detection means (C8) for detecting whether the medium (S) remains in the carrying path (SH); and drive controlling means (C19) for controlling the drive of the carrying members (Rp-Ra), and carrying the remaining medium (S) to an opened part of the carrying path (SH) when the medium (S) remains in the carrying path (SH) and the carrying path (SH) is opened.

Description

  The present invention relates to a medium conveying apparatus and an image forming apparatus.

  In a conventional image forming apparatus, when a medium is jammed in a conveyance path and the medium cannot be conveyed, that is, when a so-called paper jam occurs, a technique for conveying a medium for eliminating the paper jam or the like is disclosed in Patent Document 1 below. The techniques described in -4 are known.

Japanese Patent Laid-Open No. 3-232672 as Patent Document 1 discloses a lower guide on which an intermediate tray that temporarily stores a sheet on which an image has been recorded on the first side can stack sheets (P) when performing duplex printing. (31) and the lower guide (31), and the upper guide (30) that forms a transport path and can be separated from the lower guide (31) to open the transport path, and is downstream of the intermediate tray. The configuration is described in which the sheet (P) carried out from the intermediate tray is once switched back into the retraction path (37) where it joins at (1), and the lowermost sheet (P1) is picked up by the separation claw (38) of the joining portion. Has been.
In Patent Document 1, when the sheet (P1) conveyed from the intermediate tray to the transfer region is not detected by the sensor even after a predetermined time has elapsed, it is determined that a paper jam has occurred and the upper guide (30) is opened. The roller pair (28a, 28b, 32a, 32b) is rotated forward by a preset amount without causing the sheet (P1) to be discharged from the retreat path (37), thereby making it easier for the operator to handle the paper jam. I am letting.

Japanese Patent Application Laid-Open No. 2009-192580 as Patent Document 2 discloses a conveyance path (41) through which a sheet is conveyed, a plurality of roller units (33) provided in the conveyance path (41) and that conveys the sheet, A plurality of first detectors (37) provided on the path (41) for detecting paper jams, an open / close door (53) for operating the inside of the apparatus from the outside, and opening / closing of the open / close door (53) A paper transport device including a second detection unit (27) for detecting an operation is described.
In the paper transport device of Patent Document 2, when it is detected that a paper is jammed in the transport path (41) and the door (53) is closed after being opened, the rollers are set for a preset time. The part (33) is rotated to convey the jammed paper to facilitate the paper jam clearing operation.

Japanese Patent Application Laid-Open No. 2010-13248 as Patent Document 3 discloses a main body (1) for recording an image on a sheet, a slip sheet inserter (2) connected to the downstream side of the main body (1) in the sheet conveyance direction, An image forming apparatus having a finisher (B3) connected to the downstream side in the paper conveyance direction of the interleaf inserter (2) is described.
In the image forming apparatus of Patent Document 3, a paper jam is detected based on detection results of a plurality of conveyance sensors (4) arranged on the conveyance path, and the conveyance roller (9) stops when a paper jam is detected. After the main body door (5) of the main body (1), the interleaf inserter door (6) of the interleaf inserter (2), or the finisher door (7) of the finisher (B3) is opened, it is closed. If it is done, the conveyance roller (9) of the part corresponding to the door (5-7) in which opening / closing operation was carried out will rotate for a fixed time. Accordingly, in Patent Document 3, the paper jammed between the transport sensors (4) is detected by the transport sensor (4), and erroneously determined that the paper jam has been removed is prevented.

  In the paper post-processing device (PD) disclosed in Japanese Patent Application Laid-Open No. 2009-51594 as Patent Document 4, when a paper jam is detected by the sensors (301, 303) arranged on the transport path, the paper jam occurrence position In contrast, among the sheets on the downstream side, the most downstream sheet that has reached the sheet discharge roll (6) is controlled to continue to be conveyed and discharged to the shift tray (202). The remaining paper such as paper is controlled so as not to be conveyed outside the apparatus. Accordingly, in Patent Document 4, occurrence of problems such as folding, tearing, and roller rubbing on the downstream sheet is reduced.

JP-A-3-232672 (page 5, upper left column, line 8 to page 6, upper right column, line 11; page 6, lower left column, line 7 to page 6, lower left column, line 20, FIGS. 5 to 12) (Figure) JP 2009-192580 A (“0071” to “0076”, FIGS. 2 and 5) JP 2010-13248 A ("0011" to "0018", FIGS. 1 to 3) JP 2009-51594 A (“0082” to “0085”, “0118”, FIGS. 34 to 36)

  It is a technical object of the present invention to facilitate the operation of removing the medium remaining in the conveyance path.

In order to solve the technical problem, a medium conveying device according to claim 1 is provided.
A transport path through which the medium is transported;
A transport member provided in the transport path for transporting the medium;
A first guide unit arranged on the transport path and capable of guiding the medium;
A second guide unit arranged on the transport path and capable of guiding the medium, a transport position capable of transporting the medium to and from the first guide unit opposite the first guide unit; The second guide part movably provided between an open position that opens the conveyance path to the outside;
An opening detecting means for detecting whether or not the conveying path is opened;
Detecting the presence or absence of a medium in the transport path and detecting whether or not the medium remains in the transport path;
Drive control means for controlling the drive of the transport member, wherein when it is determined that a medium remains in the transport path and it is determined that the transport path is opened, the transport member is driven to perform the transport The drive control means for transporting the medium remaining in the path to an open part of the transport path;
It is provided with.

The invention according to claim 2 is the medium conveying apparatus according to claim 1,
Position detecting means for detecting the position of the remaining medium in the transport path;
Exposure length storage means for storing an exposure length that is a length set in advance as a length for exposing a part of the remaining medium from an open portion of the transport path;
Based on the exposure length and the position detected by the position detection means, the remaining medium is transported from the detected position until it is exposed by the exposure length. A drive time setting means for setting the drive time;
The drive control for driving the transport member during the drive time set by the drive time setting means when it is determined that the medium remains in the transport path and the transport path is opened. Means,
It is provided with.

The invention described in claim 3 is the medium conveying apparatus according to claim 2,
A passage for detecting whether or not the medium has passed a preset reference position on the upstream side in the transport direction of the transport path as compared to the positions where the first guide portion and the second guide portion are disposed. Detecting means of
The medium that has passed the reference position is the time from when it is detected that the medium has passed the reference position by the passage detection means until the medium is detected by the residual detection means to remain in the transport path. A transport time measuring means for measuring the transport time of
The position detecting means for detecting the position of the remaining medium in the transport path based on the transport time;
It is provided with.

According to a fourth aspect of the present invention, in the medium conveying apparatus according to the second or third aspect,
The exposure length storage means for storing a predetermined reference exposure length for an exposure length that is a length for exposing a part of the remaining medium from an open portion of the transport path;
When a part of the remaining medium is exposed from the opened part of the transport path, a holding length that is a length of a part of the exposed medium held in the transport path is set in advance. A retention length storage means for storing the reference retention length;
A length storage means for storing the length of the transported medium in the transport direction;
A length discriminating means for discriminating whether or not the difference between the length in the conveyance direction of the medium and the reference holding length is longer than the reference exposure length;
If the difference is determined to be longer than the reference exposure length by the length determination means, an exposure length setting means for setting the difference as the exposure length;
Based on the exposure length set by the exposure length setting means and the position detected by the position detection means, the remaining medium is transported from the detected position to determine the exposure length. The drive time setting means for setting the drive time of the conveying member until it is only exposed;
It is provided with.

The invention according to claim 5 is the medium conveying apparatus according to claim 2 or 3,
A type of storage means for storing the type of medium to be conveyed;
The exposure length storage means for storing the exposure length set in advance according to the type of medium;
An exposure length setting means for setting the exposure length based on the type of medium remaining in the conveyance path and the exposure length stored in the exposure length storage means;
Based on the exposure length set by the exposure length setting means and the position detected by the position detection means, the remaining medium is transported from the detected position to determine the exposure length. The drive time setting means for setting the drive time of the conveying member until it is only exposed;
It is provided with.

In order to solve the technical problem, an image forming apparatus according to a sixth aspect of the present invention provides:
A storage section for storing the medium;
An extraction member for taking out the medium stored in the storage unit;
The medium carrying device according to any one of claims 1 to 5, wherein the medium taken out by the take-out member is carried,
An image recording unit for recording an image on a medium conveyed by the medium conveying device;
It is provided with.

According to the first and sixth aspects of the present invention, when it is determined that the conveyance path is opened, the medium remaining in the conveyance path is more than the case where the medium remaining in the conveyance path is not conveyed. It is possible to facilitate the removal operation of the used medium.
According to the second aspect of the present invention, it is possible to reliably expose the medium as compared with the case of transporting the remaining medium without being based on the position of the remaining medium.
According to the third aspect of the present invention, the position of the medium can be detected based on the transport time.
According to the fourth aspect of the present invention, as compared with the case where it is not based on the reference exposure length and the reference holding length, the remaining medium is surely exposed and a portion to be held in the transport path is secured. I can do it.
According to the fifth aspect of the present invention, the exposed length of the medium can be changed based on the type of the medium.

FIG. 1 is an overall explanatory view of an image forming apparatus according to Embodiment 1 of the present invention. FIG. 2 is an enlarged explanatory view of a main part of the image forming apparatus according to the first embodiment. FIG. 3 is an enlarged view of a main part of FIG. 1 and is an explanatory diagram of the conveyance path. FIG. 4 is an overall explanatory view of Embodiment 1 of the present invention, and is an explanatory view for explaining a state in which the main cover moves between the open position and the normal position. FIG. 5 is a functional diagram, so-called block diagram, of the control unit of the printer according to the first embodiment of the present invention. FIG. 6 is a block diagram continued from FIG. 5 and is a block diagram of the control unit of the printer according to the first embodiment of the present invention. FIG. 7 is an explanatory diagram of the exposure length and the holding length in the paper feed path according to the first embodiment of the present invention. FIG. 8 is an explanatory diagram of the position of the recording sheet remaining in the conveyance path, and FIG. 8A is a recording sheet in which the downstream end in the conveyance direction of the recording sheet remains on the conveyance path at a position before passing the paper path sensor. FIG. 8B is an explanatory diagram of a recording sheet in which the downstream end in the conveyance direction of the recording sheet remains on the conveyance path at a position after passing the paper feed path sensor and before passing the registration sensor. FIG. 9 is an explanatory diagram of the path length and the conveyance distance of the sheet feeding path according to the first exemplary embodiment. FIG. 9A illustrates the downstream end of the recording sheet in the conveyance direction at the position before passing the sheet feeding path sensor. FIG. 9B is an explanatory diagram of the recording sheet, and FIG. 9B is an explanatory diagram of the recording sheet in which the downstream end in the conveyance direction of the recording sheet remains in the conveyance path at a position after passing the paper feed path sensor and before passing the registration sensor. FIG. 10 is an explanatory diagram of a flowchart of jam detection start processing according to the first embodiment. FIG. 11 is an explanatory diagram of a flowchart of first jam detection processing according to the first embodiment. FIG. 12 is an explanatory diagram of a flowchart of second jam detection processing according to the first embodiment. FIG. 13 is an explanatory diagram of a third jam detection process according to the first embodiment. FIG. 14 is an explanatory diagram of a flowchart of the fourth jam detection process according to the first embodiment. FIG. 15 is an explanatory diagram of a flowchart of a drive time setting process according to the first embodiment. FIG. 16 is a continuation of FIG. 15 and is an explanatory diagram of a flowchart of the drive time setting process according to the first embodiment. FIG. 17 is an explanatory diagram of a flowchart of the driving process at the time of remaining in the first embodiment. FIG. 18 is a diagram corresponding to FIG. 5 of the first embodiment, and is a block diagram of the control unit of the printer according to the second embodiment of the present invention. FIG. 19 is a block diagram continued from FIG. FIG. 20 is an explanatory diagram illustrating an example of an exposure length reference value stored in the exposure length storage unit according to the second embodiment, and FIG. 20A is an explanatory diagram regarding the exposure length fed from the uppermost sheet feed tray. FIG. 20B is an explanatory view of the exposure length fed from the lower three stages of paper feed trays. FIG. 21 is an explanatory diagram of a flowchart corresponding to FIG. 15 of the first embodiment, and is a flowchart of a drive time setting process according to the second embodiment of the present invention. FIG. 22 is an explanatory diagram of a flowchart continued from FIG. FIG. 23 is a diagram for explaining the operation of the second embodiment, and is a diagram for explaining the case where the remaining thin paper is exposed.

Next, specific examples of embodiments of the present invention (hereinafter referred to as examples) will be described with reference to the drawings. However, the present invention is not limited to the following examples.
In order to facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The direction indicated by Z and -Z or the indicated side is defined as the front side, the rear side, the right side, the left side, the upper side, the lower side, or the front side, the rear side, the right side, the left side, the upper side, and the lower side, respectively.
In the figure, “•” in “○” means an arrow heading from the back of the page to the front, and “×” in “○” is the front of the page. It means an arrow pointing from the back to the back.
In the following description using the drawings, illustrations other than members necessary for the description are omitted as appropriate for easy understanding.

FIG. 1 is an overall explanatory view of an image forming apparatus according to Embodiment 1 of the present invention.
In FIG. 1, a printer U as an example of an image forming apparatus according to a first embodiment of the present invention includes an image forming apparatus main body U1. Image information transmitted from the image information transmitting apparatus PC electrically connected to the printer U is input to the control unit C. The image information input to the control unit C is converted into yellow Y, magenta M, cyan C, and black K image information for forming a latent image at a preset time and output to the latent image forming device driving circuit DL. Is done.
When the original image is a single color image, so-called monochrome, image information of only black K is input to the latent image forming device driving circuit DL.
The latent image forming device drive circuit DL has drive circuits for respective colors Y, M, C, and K (not shown), and is arranged for each color at a predetermined time according to input image information. To the latent image forming apparatuses LHy, LHm, LHc, and LHk.

FIG. 2 is an enlarged explanatory view of a main part of the image forming apparatus according to the first embodiment.
1 and 2, the visible image forming devices Uy, Um, Uc, Uk disposed in the center of the printer U in the gravity direction form visible images of Y, M, C, and K colors, respectively. Device.
The Y, M, C, and K latent image writing lights emitted from the latent image writing light sources of the latent image forming apparatuses LHy to LHk respectively enter the rotating image carriers PRy, PRm, PRc, and PRk. In the first embodiment, the latent image forming apparatuses LHy to LHk are constituted by so-called LED arrays.
The Y visible image forming device Uy includes a rotating image carrier PRy, a charger CRy, a latent image forming device LHy, a developing device Gy, a primary transfer device T1y, and an image carrier cleaner CLy. In the first exemplary embodiment, the image carrier PRy, the charger CRy, and the image carrier cleaner CLy are configured as an image carrier unit that can be integrally attached to and detached from the image forming apparatus main body U1.
The visible image forming apparatuses Um, Uc, Uk are all configured in the same manner as the Y visible image forming apparatus Uy.

1 and 2, the image carriers PRy, PRm, PRc, and PRk are charged by their respective chargers CRy, CRm, CRc, and CRk, and then at image writing positions Q1y, Q1m, Q1c, and Q1k. An electrostatic latent image is formed on the surface of the latent image writing light. The electrostatic latent images on the surfaces of the image carriers PRy, PRm, PRc, and PRk are developed in the developing regions Q2y, Q2m, Q2c, and Q2k as a developer roll as an example of a developer carrier of the developing devices Gy, Gm, Gc, and Gk A toner image as an example of a visible image is developed with the developer held in GRy, GRm, GRc, GRk.
The developed toner image is conveyed to primary transfer regions Q3y, Q3m, Q3c, and Q3k that are in contact with an intermediate transfer belt B as an example of an intermediate transfer member. The primary transfer units T1y, T1m, T1c, and T1k disposed on the back side of the intermediate transfer belt B in the primary transfer regions Q3y, Q3m, Q3c, and Q3k are preliminarily supplied from the power supply circuit E controlled by the control unit C. At the set time, a primary transfer voltage having a polarity opposite to the charging polarity of the toner is applied.

  The toner images on the image carriers PRy to PRk are primarily transferred onto the intermediate transfer belt B by the primary transfer devices T1y, T1m, T1c, and T1k. Residues and deposits on the surface of the image carrier PRy, PRm, PRc, PRk after the primary transfer are cleaned by the image carrier cleaner CLy, CLm, CLc, CLk. The cleaned surfaces of the image carriers PRy, PRm, PRc, and PRk are recharged by the chargers CRy, CRm, CRc, and CRk.

  Above the image carriers PRy to PRk, a belt module BM as an example of an intermediate transfer device that can move up and down and can be pulled out forward is disposed. The belt module BM includes the intermediate transfer belt B, a belt drive roll Rd as an example of an intermediate transfer body drive member, a tension roll Rt as an example of an intermediate transfer body stretching member, and a walking roll as an example of a meandering prevention member. Rw, an idler roll Rf as an example of a driven member, a backup roll T2a as an example of a secondary transfer region facing member, and the primary transfer units T1y, T1m, T1c, T1k. The intermediate transfer belt B can be rotated by belt support rolls Rd, Rt, Rw, Rf, T2a as an example of an intermediate transfer member support member constituted by the rolls Rd, Rt, Rw, Rf, T2a. It is supported by.

A secondary transfer roll T2b as an example of a secondary transfer member is disposed facing the surface of the intermediate transfer belt B in contact with the backup roll T2a, and a secondary transfer device T2 is configured by the rolls T2a and T2b. ing. A secondary transfer region Q4 is formed in a region where the secondary transfer roll T2b and the intermediate transfer belt B face each other.
The single-color or multi-color toner images transferred on the intermediate transfer belt B by the primary transfer units T1y, T1m, T1c, and T1k in the primary transfer regions Q3y, Q3m, Q3c, and Q3k It is conveyed to the secondary transfer area Q4.
The primary transfer units T1y to T1k, the intermediate transfer belt B, the secondary transfer unit T2, and the like constitute a transfer device T1 + T2 + B according to the first exemplary embodiment.

Below the visible image forming devices Uy to Uk, a pair of left and right guide rails GR as an example of a guide member is provided, and the guide rail GR has a sheet feed tray as an example of a storage unit. TR1 to TR4 are supported so as to be able to enter and exit in the front-rear direction. The recording sheet S as an example of a medium accommodated in the paper feed trays TR1 to TR4 is an example of a conveyance member, and is taken out by a pickup roll Rp as an example of a take-out member. The sheets are separated one by one by a separating roll Rs as an example of a spreading member. The recording sheet S is conveyed by a plurality of conveying rolls Ra as an example of a conveying member along a sheet feeding path SH1 which is an example of a conveying path of the recording sheet S, and is upstream of the secondary transfer region Q4 in the sheet conveying direction. It is an example of a conveying member arranged on the side, and is sent to a registration roll Rr as an example of a medium conveying timing adjustment member.
The pickup roll Rp, the separating roll Rs, and the like constitute the paper feeding device Rp + Rs of the first embodiment.
Further, on the left side of the uppermost sheet feed tray TR1, a manual feed tray TR0, which is an example of a storage unit and is an example of a manual sheet feed unit, is installed. The recording sheet S supported by the manual feed tray TR0 is fed by a manual feed roll Rp0 as an example of a manual feed member, conveyed through the manual feed path SH0, and sent to the registration roll Rr.

The registration roll Rr is an example of a conveyance path on the downstream side of the sheet feeding path SH1 with the timing when the toner image formed on the intermediate transfer belt B is conveyed to the secondary transfer area Q4. And the recording sheet S is conveyed to the secondary transfer region Q4. When the recording sheet S passes through the secondary transfer region Q4, the backup roll T2a is grounded, and the secondary transfer unit T2b is supplied with a polarity opposite to the charged polarity of the toner from the power supply circuit E controlled by the control unit C. A secondary transfer voltage is applied. At this time, the toner image on the intermediate transfer belt B is transferred to the recording sheet S by the secondary transfer device T2.
The intermediate transfer belt B after the secondary transfer is cleaned by a belt cleaner CLb as an example of an intermediate transfer body cleaner.

The recording sheet S on which the toner image is secondarily transferred has a fixing region Q5 which is a pressure contact region of a heating roll Fh as an example of a heating fixing member of the fixing device F and a pressure roll Fp as an example of a pressure fixing member. And heated and fixed when passing through the fixing region Q5. Note that a release agent for improving the releasability of the recording sheet S from the heating roll is applied to the surface of the heating roll Fh by a release agent coating device Fa.
The visible image forming devices Uy to Uk, the belt module BM, the secondary transfer device T2, the fixing device F, and the like constitute the image recording units Uy to Uk + BM + T2 + F of the first embodiment.
A sheet discharge path SH3 as an example of a conveyance path for conveying the recording sheet S to a sheet discharge tray TRh as an example of a medium discharge portion, and an inversion or image recording, which is on the downstream side in the conveyance direction of the fixing device F. An upper connection path SH4 is provided as an example of a conveyance path through which the recording sheet S discharged with the surface facing upward is conveyed. A connecting portion between the paper discharge path SH3 and the upper connection path SH4 is provided with a first gate GT1 as an example of a transport path switching member that switches the transport path according to the transport destination of the recording sheet S. Therefore, when the paper is discharged to the paper discharge tray TRh, the fixed recording sheet S is conveyed through the paper discharge path SH3 and discharged to the paper discharge tray TRh by the paper discharge roll Rh.

An optional discharge unit U3, which is an example of an additional medium discharge device, is supported above the fixing device F, and the optional discharge unit U3 is disposed above the discharge tray TRh to be discharged from the discharge tray TRh. The face-down tray TRh2 as an example of a downward stacking unit stacked with the image recording surface facing down, and the face-up as an example of an upward stacking unit stacked with the image recording surface facing up And a tray TRh3. Inside the optional discharge unit U3, a reversing / discharging common path SH5 as an example of a conveying path connected to the upper connection path SH4, and a recording sheet connected to the reversing / discharging common path SH5 and on the face-down tray TRh2 A face-down discharge path SH6 as an example of a conveyance path for sending S, and a face-up discharge path SH7 as an example of a conveyance path that is connected to the reversal / discharge common path SH5 and sends the recording sheet S to the face-up tray TRh3; Have In the face-down discharge path SH6, a reversing roll Rh2 capable of forward and reverse rotation is disposed as an example of a conveying member and an example of a medium discharging member / medium reversing member, and the face-up discharging path SH7 A face-up sheet discharge roll Rh3, which is an example of a conveyance member and is an example of a medium discharge member, is disposed, and conveys the recording sheet S in each of the conveyance paths SH6 and SH7.
A second gate GT2 as an example of a conveyance path switching member for switching the conveyance path of the recording sheet S is disposed at a connection portion between the reversal / discharge common path SH5, the face-down discharge path SH6, and the face-up discharge path SH7. Yes. The second gate GT2 switches the conveyance path to the face-down discharge path SH6 when the recording sheet S is discharged to the face-down tray TRh2 and when reversed for duplex printing, and the recording sheet S is transferred to the face-up tray TRh3. When the paper is discharged, the conveyance path is switched to the face-up discharge path SH7.

  A reversing unit U4 as an example of an additional unit is installed on the left side of the image forming apparatus main body U1. The reversing unit U4 is provided with a reversing path SH8, which is connected to the lower end of the reversing / discharging common path SH5 and is an example of a transport path for transporting the recording sheet S during duplex printing. The reversing path SH8 includes a main reversing path SH8a extending linearly along the direction of gravity, an upstream reversing path SH8b connecting the main reversing path SH8a and the reversing / discharging common path SH5, and the main reversing path SH8a. And a downstream inversion path SH8c connecting the registration roll Rr. A third gate GT3 as an example of a conveyance path switching member that switches the conveyance path so that the recording sheet S is not conveyed to the upper connection path SH4 at the time of reversal is provided at the connection portion between the upstream reversal path SH8b and the reversal / discharge common path SH5. Is arranged. A reversing path as an example of a reversing path transporting member that transports the recording sheet S in the reversing path SH8 is provided on the reversing path SH8 that is a transport path downstream of the reversing / discharging common path SH5 and the face-down discharging path SH6. A transport roll Ra2 is disposed.

  Therefore, the recording sheet S to be printed on both sides is conveyed through the reversing / discharging common path SH5 and discharged to the face-down tray TRh2 until the rear end portion of the recording sheet S is sandwiched by the reversing roll Rh2. After that, the reverse roll Rh2 rotates in the reverse direction, and the recording sheet S is conveyed to the reverse path SH8. The recording sheet S transported through the reversing path SH8 is transported by the reversing path transport roll Ra2, and is transported to the registration roll Rr with the front and back sides reversed.

FIG. 3 is an enlarged view of a main part of FIG. 1 and is an explanatory diagram of the conveyance path.
1 and 3, the sheet feeding path SH1 is an exclusive path through which the recording sheet S that extends from the sheet feeding trays TR1 to TR4 and is accommodated in the sheet feeding trays TR1 to TR4 is conveyed as an example of a conveying path. 1-4, the upstream merge path 6 to which the lower three-stage dedicated paths 2 to 4 are connected, and the downstream merge that extends upward from the upstream merge path 6 and is connected to the upper dedicated path 1 Road 7. Of the dedicated paths 1 to 4 of the first embodiment, the lower three dedicated paths 2 to 4 are configured identically. In the dedicated paths 1 to 4, on the downstream side in the conveyance direction of the separating roll Rs, as an example of a medium detection member for detecting the recording sheet S, sheet feeding path sensors SN 1, SN 2, SN 3, SN 4, respectively, Has been placed. Further, a registration sensor SN5 as an example of a medium detection member is disposed on the upstream side in the conveyance direction of the registration roll Rr. Further, in FIG. 1, the upper connection path SH4, the reversal / discharge common path SH5, and the main reversal path SH8b also include a connection path sensor SN6, a common path sensor SN7, and a reversal path sensor SN8 as examples of medium detection members. Each is arranged. In addition, discharge sensors SNh, SNh2, and SNh3, which are examples of medium detection members, are disposed upstream of the discharge rollers Rh, Rh2, and Rh3 in the transport direction.

1 and 3, on the left side of the lower three-stage sheet feeding trays TR2 to TR4, a lower cover U1a as an example of an upstream opening member is in a normal position indicated by a solid line in FIG. It is supported so as to be openable and closable between an open position indicated by a broken line in FIG.
A portion corresponding to the lower cover U1a is supported by the image forming apparatus main body U1 as an example of the first guide portion in the upstream combined flow path 6 on the upstream combined flow path 6. As an example of the sheet guide 11 on the main body side capable of guiding the recording sheet S and the second guide portion in the upstream joint channel 6, the cover side on the cover side supported by the lower cover U1a and capable of guiding the recording sheet S is provided. A sheet guide 12 is disposed. The cover-side sheet guide 12 is configured to be movable integrally with the lower cover U1a. A normal position indicated by a solid line in FIG. 1 as an example of a transport position in which the upstream confluent channel 6 that can be transported is configured, and the upstream junction 6 in the upstream paper feed path SH1a are opened to the outside. And an open position indicated by a broken line is supported so as to be movable.
A driving-side conveyance member 13 of the conveyance roll Ra is provided on the sheet guide 11 on the main body side, and a driven-side conveyance of the conveyance roll Ra is provided on the sheet guide 12 on the cover side. A member 14 is provided. Therefore, when the lower cover U1a moves to the normal position, the driving-side conveyance member 13 and the driven-side conveyance member 14 face each other and convey the recording sheet S as the conveyance roll Ra.

FIG. 4 is an overall explanatory view of Embodiment 1 of the present invention, and is an explanatory view for explaining a state in which the main cover moves between the open position and the normal position.
4, in the image forming apparatus main body U1, a main cover U1b as an example of a downstream opening member is shown above the lower cover U1a by a normal position shown by a solid line in FIG. 4 and a broken line in FIG. It is supported to be openable and closable with respect to the open position.
3 and 4, on the conveyance paths SH1 to SH4 corresponding to the main cover U1b, the sheet guide 16 on the main body side as an example of the first guide portion in the conveyance paths SH1 to SH4, A cover-side sheet guide 17 is disposed as an example of a second guide portion in the transport paths SH1 to SH4.
The main cover U1b and the sheet guides 16 and 17 are the same as the lower cover except that the downstream side combined path 7, the main transport path SH2, and the upper connection path SH4 can be opened in the downstream sheet feeding path SH1b. Since it is configured in the same manner as U1a and the sheet guides 11 and 12, detailed description thereof is omitted.

In FIG. 1, in the reversing unit U4, a reversing cover U4a as an example of an opening member of the reversing path SH8 can be opened and closed between a normal position indicated by a solid line in FIG. 1 and an open position indicated by a broken line in FIG. It is supported by.
In FIG. 1 and FIG. 3, a part of the reversing path SH8 corresponding to the reversing cover U4a, that is, on the main reversing path SH8a, as an example of the first guide portion in the main reversing path SH8a, is connected to the main cover U1b. A fixed sheet guide 18 and an opening sheet guide 19 as an example of a second guide portion in the main reversing path SH8a are arranged.
The reverse cover U4a and the sheet guides 18 and 19 are configured in the same manner as the lower cover U1a and the sheet guides 11 and 12 except that the main reverse path SH8a is configured to be openable. Omitted.

Here, in the printer U of the first embodiment, as an example of a shut-off device, an interlock switch that forcibly cuts off the power supply to the drive source or the like in conjunction with the opening of the covers U1a, U1b, U4a. This configuration is not applicable to the Ra drive source. That is, in the first embodiment, when the covers U1a, U1b, and U4a are opened, the heating sources for driving the image carriers PRy to PRk and the developing devices Gy to Gk, the chargers CRy to CRk, and the fixing device F are heated. Although power supply to the rolls Fh and the like is interrupted, power supply to the drive sources of the transport members Rp to Ra is continued and the transport members Rp to Ra can be driven.
Each of the transport paths SH1 to SH8 constitutes a transport path SH of Example 1, and includes the transport path SH, a pickup roll Rp, a separating roll Rs, a transport roll Ra, a registration roll Rr, a paper discharge roll Rh, a reverse roll Rh2, The face-up paper discharge roll Rh3, the reverse path transport roll Ra2, the gates GT1 to GT3, the lower cover U1a, the main cover U1b, the reverse cover U4a, and the like constitute the medium transport apparatus BHS of the first embodiment.

  Above the belt module BM, developer cartridges Ky, Km, Kc, and Kk are disposed as an example of a developer supply container that stores yellow Y, magenta M, cyan C, and black K developers. The developer contained in each developer cartridge Ky, Km, Kc, Kk is supplied from the developer supply path to each of the developing devices Gy, Gm according to consumption of the developer in the developing devices Gy, Gm, Gc, Gk. , Gc, Gk. In Example 1, the developer is composed of a two-component developer including a magnetic carrier and a toner provided with an external additive.

(Description of the control part of Example 1)
FIG. 5 is a functional diagram, so-called block diagram, of the control unit of the printer according to the first embodiment of the present invention.
FIG. 6 is a block diagram continued from FIG. 5 and is a block diagram of the control unit of the printer according to the first embodiment of the present invention.
5 and 6, the control unit C includes an input / output interface I / O for inputting / outputting signals from / to the outside, a ROM: a read-only memory storing a program and information for performing necessary processing, and the like. A RAM for temporarily storing necessary data: a random access memory; a CPU for performing processing according to a program stored in the ROM: a central processing unit; and a small information processing apparatus having an oscillator or the like, a so-called micro It is constituted by a computer, and various functions can be realized by executing a program stored in the ROM.

(Signal output element connected to control unit C)
The control unit C includes an operation unit UI, paper feed path sensors SN1 to SN4, a registration sensor SN5, a connection path sensor SN6, a common path sensor SN7, a reverse path sensor SN8, discharge sensors SNh to SNh3, and an example of a detection member for an opening member. Output signals from signal output elements such as the cover sensors SN11, SN12, and SN13.
The operation unit UI includes a power button UI1, a display unit UI2, an arrow button UI3 as an example of an input button, a setting button UI4, and a residual cancellation input that is input when the operation of removing the remaining recording sheet S is completed. A button UI5 is provided.
Each sensor SN1-SN8, SNh-SNh3 of conveyance path SH detects the presence or absence of recording sheet S on conveyance path SH at the position where sensors SN1-SN8, SNh-SNh3 are arranged.
The cover sensor SN11 for the lower cover U1a, the cover sensor SN12 for the main cover U1b, and the cover sensor SN13 for the reversing cover U4a detect whether or not the corresponding covers U1a to U4a are held at the normal positions.

(Controlled element connected to control unit C)
The control unit C is connected to a main drive source drive circuit D1, a power supply circuit E, a paper feed device drive circuit D2, a conveyance member drive circuit D3, a reversing member drive circuit D4, and other control elements (not shown). The operation control signal is output.
The main drive source drive circuit D1 rotationally drives the image carriers PRy to PRk, the intermediate transfer belt B, and the like via the main drive source M1.
The power supply circuit E includes a development power supply circuit Ea, a charging power supply circuit Eb, a transfer power supply circuit Ec, a fixing power supply circuit Ed, and the like.

The developing power supply circuit Ea applies a developing voltage to the developing rolls of the developing devices Gy to Gk.
The charging power supply circuit Eb applies a charging voltage for charging the surfaces of the image carriers PRy to PRk to the chargers CRy to CRk.
The transfer power supply circuit Ec applies a transfer voltage to the primary transfer units T1y to T1k and the secondary transfer roll T2b.
The fixing power supply circuit Ed supplies a heater heating power to the heating roll Fh of the fixing device F.
The paper feed device drive circuit D2 drives the paper feed device Rp + Rs via the paper feed drive source M2.
The transport member drive circuit D3 drives the transport roll Ra and the paper discharge roll Rh via the transport drive source M3.
The reversing member drive circuit D4 drives the reversing roll Rh2 in the forward and reverse directions via the reversing drive source M4.

(Function of control unit C)
The control unit C has a function of executing processing according to an input signal from the signal output element and outputting a control signal to each control element. That is, the control unit C has the following functions.
C1: Image Forming Operation Control Unit The image forming operation control unit C1 controls the driving of each member of the printer U, the application timing of each voltage, and the like according to the image information input from the information processing apparatus PC, thereby forming an image. A job as an example of an operation is executed.
C2: Main drive source control means The main drive source control means C2 controls the drive of the main drive source M1 via the main drive source drive circuit D1, and controls the drive of the image carriers PRy to PRk and the like.

C3: Power supply circuit control means The power supply circuit control means C3 includes a development power supply circuit control means C3A, a charging power supply circuit control means C3B, a transfer power supply circuit control means C3C, and a fixing power supply circuit control means C3D. Then, the operation of the power supply circuit E is controlled to control voltage application and power supply to each member.
C3A: Developing power circuit control means The developing power circuit control means C3A controls the developing power circuit Ea to control the developing voltage applied to the developing rolls of the developing devices Gy to Gk.
C3B: Charging power supply circuit control means The charging power supply circuit control means C3B controls the charging power supply circuit Eb to control the charging voltage applied to the chargers CRy to CRk.

C3C: Transfer power supply circuit control means The transfer power supply circuit control means C3C controls the transfer power supply circuit Ec and applies it to the primary transfer voltage applied to the primary transfer devices T1y to T1k and to the secondary transfer roll T2b. The secondary transfer voltage is controlled.
C3D: Fixing power supply circuit control means The fixing power supply circuit control means C3D controls the temperature of the heater of the heating roll Fh of the fixing device F, that is, controls the fixing temperature, by controlling the fixing power supply circuit Ed.

C4: Type Storage Unit The type storage unit C4 stores the type of the recording sheet S to be conveyed. The storage means C4 of the type of the first embodiment is a recording sheet S including sizes of A4, A3, and paper types such as thick paper, plain paper, thin paper, etc., for the recording sheets S accommodated in the trays TR0, TR1 to TR4. Are stored for each tray TR0 to TR4. In the first embodiment, the type storage unit C4 also stores the sheet length S1 associated with the size of the recording sheet S being conveyed as an example of the length in the conveyance direction. Also have.
C5: Tray Setting Unit A tray setting unit C5 as an example of a setting unit of the storage unit is configured to store the recording sheet S to be printed input from the information processing apparatus PC in accordance with input of image information from the information processing apparatus PC. Based on the type information and the stored information stored in the type storage means C4, the trays TR0 to TR4 used during the image forming operation are set.
C6: Conveying Device Control Unit The conveying device control unit C6 includes a paper feed control unit C6A, a conveyance control unit C6B, and a reversal control unit C6C, and performs duplex printing on the recording sheet S and discharge trays TRh, TRh2, TRh3. The operation of the medium conveying device BHS is controlled according to the designation, setting, setting by the tray setting means C5, etc., and the driving of each conveying member Rp, Rs, Rr, Ra, Rh to Rh3 and the operation of the gates GT1 to GT3 are controlled. And the conveyance of the recording sheet S is controlled.

C6A: Paper Feed Control Unit The paper feed control unit C6A controls the drive of the paper feed drive source M2 via the paper feed device drive circuit D2, and controls the paper feed of the recording sheet S by the paper feed device Rp + Rs.
C6B: Conveyance Control Unit The conveyance control unit C6B controls driving of the conveyance drive source M3 via the conveyance member drive circuit D3, and controls conveyance of the recording sheet S by the conveyance roll Ra and the discharge roll Rh.
C6C: Inversion Control Unit The inversion control unit C6C controls the driving of the inversion drive source M4 via the inversion member drive circuit D4, and controls the paper discharge by the inversion roll Rh2 and the conveyance to the inversion path SH8.

C7: Sheet detection means The sheet detection means C7 as an example of the passage detection means includes sheet detection means C7A to C7H and C7J to C7L corresponding to the sensors SN1 to SN8 and SNh to SNh3 of the conveyance path SH. Based on the detection results of the sensors SN1 to SN8 and SNh to SNh3, it is detected whether the recording sheet S has passed the detection positions of the sensors SN1 to SN8 and SNh to SNh3. That is, when the sensors SN1 to SN8 and SNh to SNh3 detect the absence of the recording sheet S, the sheet detection means C7A to C7H and C7J to C7L have the sensors SN1 to SN8 at the front end in the conveyance direction of the recording sheet S. , SNh to SNh3 are detected and the sensors SN1 to SN8 and SNh to SNh3 detect the presence or absence of the recording sheet S, the rear end of the recording sheet S in the conveyance direction is the sensors SN1 to SN8. , SNh to SNh3 are detected to have passed.
C8: Residual detection means The residual detection means C8 includes a jam time storage means C8A, a jam time timing means C8B, a start signal transmission means C8C, an end signal transmission means C8D, and a jam determination means C8E. , A jam signal transmission means C8F, and the presence or absence of the recording sheet S in the conveying path SH is detected, and whether or not the recording sheet S remains in the conveying path SH, that is, the recording sheet S enters the conveying path SH. It is detected whether jamming occurs as an example of jammed paper, or whether the recording sheet S is stopped in the conveyance path SH due to jamming.

C8A: Jam time storage means A jam time storage means C8A as an example of a paper jam determination time storage means is a detection position of each of the sensors SN1 to SN8 and SNh to SNh3 when the recording sheet S conveyed on the conveyance path SH is detected. Is stored for each of the sensors SN1 to SN8 and SNh to SNh3. In the first exemplary embodiment, the jam time storage unit C8A includes the times t1 to t4 from the start of paper feeding by the paper feeding devices Rp + Rs of the paper feeding trays TR1 to TR4 to the passage through the paper feeding path sensors SN1 to SN4. Each time t5 from passing through the paper feed path sensors SN1 to SN4 to passing through the registration sensor SN5, time t6 from passing through the registration sensor SN5 to passing through the connection path sensor SN6, and passing through the connection path sensor SN6 Time t7 until the vehicle passes the common path sensor SN7, time t8 from the passage through the common path sensor SN7 to the passage through the reverse path sensor SN8, and the registration sensor SN5 after passing through the reverse path sensor SN9. A time t9 until the vehicle passes, a time t10 from the passage through the registration sensor SN5 to the passage through the discharge sensor SNh, and the passage through the common path sensor SN7. And the time t11 until passing the discharge sensor SNh2 from the stores and time t12 from through the common path sensor SN7 to pass through a discharge sensor SNH3. Each of the times t1 to t12 is a margin, based on the configuration of the medium transport device BHS, in the arrival time of the reference based on the setting of the transport speed and the distance between the sensors SN1 to SN8 and SNh to SNh3. It is preset in consideration of the margin.

C8B: Jam time measuring means J8 time measuring means C8B as an example of a paper jam determination time measuring means is a jam time measuring means C8B1-C8B8, C8B9-corresponding to each of the sensors SN1-SN8, SNh-SNh3. C8B11, and measures the times t1 to t12 stored in the jam time storage means C8A.
C8C: Start signal sending means The start signal sending means C8C sends a start signal, which is a control signal for starting the time measuring means C8B1 to C8B11 of the jam time based on the detection result of the sheet detecting means C7. . The start signal transmission means C8C according to the first exemplary embodiment is configured such that when paper feeding by the paper feeding device Rp + Rs is started, the jamming time measuring means C8B1 to C8B4 of the paper feeding path sensors SN1 to SN4 corresponding to the paper feeding device Rp + Rs. Send a start signal. When the downstream end of the recording sheet S in the conveyance direction of the recording sheet S passes through the paper path sensors SN1 to SN4, the start signal transmission unit C8C according to the first embodiment outputs a start signal of the jamming time measuring unit C8B5 of the registration sensor SN5. send.

  Further, the start signal transmission means C8C according to the first embodiment uses the registration sensor SN5 at the downstream end in the conveyance direction of the recording sheet S in the case of setting to discharge to the trays TRh2 and TRh3 of the optional discharge unit U3 or in the case of duplex printing. Is transmitted, the start signal of the time measuring means C8B6 of the jam time of the connection path sensor SN6 is transmitted. When the downstream end of the recording sheet S in the transport direction passes through the connection path sensor SN6, the start signal transmission means C8C of the first embodiment transmits the start signal of the jam time measuring means C8B7 of the common path sensor SN7. To do. Further, in the case of double-sided printing, the start signal transmission means C8C of Embodiment 1 jams the reverse path sensor SN8 when the downstream end in the transport direction of the recording sheet S on which single-side recording has been performed passes through the common path sensor SN7. A start signal of time measuring means C8B8 is transmitted. Then, when the downstream end of the recording sheet S in the conveyance direction of the recording sheet S passes through the reverse path sensor SN8, the start signal transmission unit C8C of the first embodiment transmits a start signal of the jamming time measuring unit C8B5 of the registration sensor SN5.

  In the case where the start signal transmission means C8C of the first embodiment is set to discharge the recording sheet S to the paper discharge tray TRh, the discharge sensor C8C discharges the registration sensor SN5 when the downstream end in the conveyance direction of the recording sheet S passes. The start signal of the time measuring means C8B9 for SNh jam time is transmitted. Further, in the case where the start signal transmission means C8C of the first embodiment is set to discharge the recording sheet S to the face-down tray TRh2, when the downstream end in the conveyance direction of the recording sheet S passes through the common path sensor SN7, The start signal of the time measuring means C8B10 for jam time of the discharge sensor SNh2 is transmitted. Further, in the case where the start signal transmission means C8C of Example 1 is set to discharge the recording sheet S to the face-up tray TRh3, when the downstream end in the conveyance direction of the recording sheet S passes the common path sensor SN7, The start signal of the time measuring means C8B11 of the jam time of the discharge sensor SNh3 is transmitted.

C8D: End signal transmission means The end signal transmission means C8D transmits an end signal, which is a control signal for ending the time measurement by the time measurement means C8B1 to C8B11 of the jam signal based on the detection result of the sheet detection means C7. . The end signal transmission means C8D of Example 1 corresponds to the sensors SN1 to SN8 and SNh when the downstream end in the conveyance direction of the recording sheet S is detected to have passed the detection positions of the sensors SN1 to SN8 and SNh to SNh3. The timing of the times t1 to t12 by the time measuring means C8B1 to C8B11 of the SNh3 is terminated halfway.
C8E: Jam Judging Unit A jam judging unit C8E as an example of a paper jam judging unit discriminates whether or not a jam as an example of a paper jam has occurred in the transport path SH. The jam determination means C8E according to the first embodiment is a so-called time when the time measurement means C8B completes the time measurement of the times t1 to t12 without any end by the time measurement means C8B1 to C8B11. When the recording sheet S is up, it is determined that a jam occurs in the transport path SH and the recording sheet S remains in the transport path SH.

C8F: Jam signal sending means A jam signal sending means C8F, which is an example of a paper jam notification signal sending means, outputs a paper jam notification signal when the jam judging means C8E determines that a jam has occurred. As an example, a jam signal notifying that a jam has occurred is transmitted. In the first embodiment, the jam signal transmitting means C8F transmits a jam signal and also transmits a control signal for stopping the driving of the transport members Rp to Rh to the transport device control means C6. Accordingly, in the first exemplary embodiment, when a jam occurs when a plurality of recording sheets S are being conveyed on the conveyance path SH, the recording sheets S other than the recording sheet S jammed in the conveyance path SH are also stopped in the conveyance path SH. And remain.

FIG. 7 is an explanatory diagram of the exposure length and the holding length of the first embodiment of the present invention.
C9: Exposure Length Storage Unit The exposure length storage unit C9 is configured in advance with respect to an exposure length that is a length for exposing a part of the recording sheet S remaining in the conveyance path SH from an opened portion of the conveyance path SH. The set reference exposure lengths L1 and L2 are stored. In FIG. 7, the exposure length storage unit C9 according to the first exemplary embodiment is a reference for exposing the recording sheet S conveyed from the paper feed tray TR1 from the conveyance paths 7, SH2, and SH4 opened by the main cover U1b. The exposure length L1 is stored. Further, the exposure length storage unit C9 according to the first exemplary embodiment exposes the recording sheet S conveyed from the paper feed trays TR2 to TR4 from the conveyance path 6 opened by the lower cover U1a. Is remembered. In the first embodiment, the reference exposure lengths L1 and L2 are set according to the lengths of the exposed portions protruding to the left with respect to the sheet guides 11 and 16 on the main body side. The length required for the user to pull out the recording sheet S from the conveyance path SH is measured and set in advance by an experiment or the like.

C10: Holding Length Storage Unit The holding length storage unit C10 exposes the recording sheet S that is exposed when a part of the recording sheet S remaining in the conveyance path SH is exposed from an opened portion of the conveyance path SH. Reference holding lengths H1 and H2 set in advance are stored for the holding length which is the length of the portion held in the transport path SH. In FIG. 7, the holding length storage unit C10 according to the first exemplary embodiment includes the reference holding length H1 for the recording sheet S conveyed from the sheet feeding tray TR1 and the recording sheet S conveyed from the sheet feeding trays TR2 to TR4. The reference holding length H2 is stored. In Example 1, when the remaining recording sheet S is exposed as the reference holding length H1, the upstream portion in the conveyance direction of the recording sheet S is surely sandwiched between the conveyance rolls Ra. The sheet guide 16 on the main body side is arranged from the position P1 where the upstream end in the conveyance direction of the recording sheet S is stopped and from the position P1 set in advance in consideration of the margin on the upstream side in the conveyance direction of the conveyance roll Ra. A length H1 is set along the exclusive path 1 to the junction P5 with the downstream junction 7.

  Further, as the reference holding length H2, the sheet guide 11 on the main body side from the positions P2 to P4 set in advance similarly to the position P1 on the upstream side in the transport direction of the separating rolls Rs of the sheet feeding trays TR2 to TR4. The length H2 is set along the dedicated paths 2 to 4 from the merge points P6 to P8 with the upstream merge path 6 in which is arranged. Therefore, when the recording sheet S is exposed, if the length longer than the reference holding lengths H1 and H2 is held in the transport path SH, the transport members Ra and the upstream of the covers U1b and U1a in the transport direction Even if the exposed portion of the recording sheet S is heavy, it is difficult for the exposed recording sheet S to fall. In Example 1, the exposed length side portion of the recording sheet S and the holding length side portion of the recording sheet S are separated by using the merge points P5 to P8 as boundaries.

C11: Sheet Length Discriminating Unit A sheet length discriminating unit C11 as an example of a length discriminating unit includes a sheet length S1 as an example of a length in the conveyance direction of the recording sheet S, and the reference holding length H1, It is determined whether or not the differences S1-H1, S1-H2 from H2 are longer than the reference exposure lengths L1, L2. The sheet length determination unit C11 according to the first exemplary embodiment is configured such that when the sheet feeding tray TR1 is set by the tray setting unit C5, the sheet length S1 of the recording sheet S accommodated in the sheet feeding tray TR1 and the reference holding length. It is determined whether or not the difference S1−H1 from H1 is longer than the reference exposure length L1. The sheet length determination unit C11 according to the first exemplary embodiment is configured such that the sheet length S1 of the recording sheet S accommodated in the sheet feeding trays TR2 to TR4 when the sheet feeding trays TR2 to TR4 are set by the tray setting unit C5. And the difference S1-H2 between the reference holding length H2 and the reference exposure length L2 is determined.

C12: Exposure length setting means The exposure length setting means C12 is determined by the sheet length determination means C11 that the differences S1-H1, S1-H2 are longer than the reference exposure lengths L1, L2. In the case of the difference, the difference S1-H1, S1-H2 is set as the exposure length. That is, in FIG. 7, when the difference S1-H1, S1-H2 is longer than the reference exposure lengths L1, L2, the exposure length setting means C12 of Embodiment 1 sets the exposure length to L3: L3 = S1-H1, L4: Set as L4 = S1-H2. Further, the exposure length setting means C12 of the first embodiment sets the exposure length as L1 and L2 when the difference S1-H1, S1-H2 is equal to or less than the reference exposure length L1, L2. Therefore, in Example 1, the exposure length is set to a value equal to or greater than the reference exposure lengths L1 and L2.

C13: Transport Time Measuring Unit The transport time measuring unit C13 detects that the recording sheet S remains on the transport path SH by the residual detection unit C8 after the paper feeding by the paper feeding device Rp + Rs is started. Is measured as the conveyance time ta when the recording sheet S fed by the paper feeding device Rp + Rs is conveyed. Further, the transport time measuring means C13 detects that the recording sheet S has passed the detection positions of the paper feed path sensors SN1 to SN4 by the sheet detection means C7 and then the residual detection means C8 detects the transport path. The time until it is detected that the recording sheet S remains on the SH is measured as the conveyance time ta of the recording sheet S that has passed the detection positions of the sheet feeding path sensors SN1 to SN4.

  The conveyance time measuring unit C13 according to the first exemplary embodiment is configured to measure the conveyance time ta in which the recording sheet S is conveyed after the sheet is fed by the sheet feeding device Rp + Rs until the jam occurs, and the jamming time measuring unit C8B1 to C8B4. Measure based on the time counted by. Specifically, the time obtained by subtracting the remaining time measured by the jamming time measuring means C8B1 to C8B4 from the time t1 to t4 set in the jamming time measuring means C8B1 to C8B4, when the jam occurs. It is measured as the conveyance time ta. Similarly, the conveyance time measuring unit C13 according to the first exemplary embodiment uses the conveyance time ta, in which the recording sheet S is conveyed from when the paper passes the sheet path sensors SN1 to SN4 until the jam occurs, to the jam time. The time is measured based on the time measured by the time measuring means C8B5. Specifically, a time obtained by subtracting the remaining time measured by the jamming time measuring means C8B5 when a jam occurs from the time t5 set in the jamming time measuring means C8B5 is measured as the transport time ta. . In the first embodiment, the detection positions of the sheet feed path sensors SN1 to SN4 as an example of the reference position are compared with the positions where the sheet guides 11 and 16 on the main body side and the sheet guides 12 and 17 on the cover side are arranged. Therefore, it is set in advance on the upstream side in the transport direction of the paper feed path SH1.

C14: Transport Speed Storage Unit The transport speed storage unit C14 stores the transport speed V1 of the transport members Rp to Ra of the medium transport apparatus BHS. In the first embodiment, the transport speed V1 stored in the transport speed storage unit C14 is set and stored in advance according to the design and specifications of the medium transport apparatus BHS.
C15: Position calculation means The position calculation means C15 as an example of the position detection means is configured so that the transfer speed V1 stored in the transfer speed storage means C14 and the transfer time ta measured by the transfer time measurement means C13. Based on this, as an example of the position of the remaining recording sheet S in the transport path SH, the position of the downstream end of the recording sheet S in the transport direction is calculated and detected.

FIG. 8 is an explanatory diagram of the position of the recording sheet remaining in the conveyance path, and FIG. 8A is a recording sheet in which the downstream end in the conveyance direction of the recording sheet remains on the conveyance path at a position before passing the paper path sensor. FIG. 8B is an explanatory diagram of a recording sheet in which the downstream end in the conveyance direction of the recording sheet remains on the conveyance path at a position after passing the paper feed path sensor and before passing the registration sensor.
In FIG. 8, the position calculation unit C15 according to the first exemplary embodiment supplies a sheet feeding device for the recording sheet S remaining in the sheet feeding path SH1 at a position before the downstream end in the transport direction passes the sheet feeding path sensors SN1 to SN4. Based on the transport speed V1 of Rp + Rs and the transport time ta, as shown in FIG. 8A, a distance X1: X1 = V1 × ta from the left end walls TR1a to TR4a of the paper feed trays TR1 to TR4 is calculated. The position of the downstream end in the conveyance direction of the recording sheet S is calculated and detected. In addition, the position calculation unit C14 according to the first exemplary embodiment has the recording sheet S remaining in the sheet feeding path SH1 at a position before the downstream end in the transport direction passes the sheet feeding path sensors SN1 to SN4 and before the registration sensor SN5. , Based on the transport speed V1 of the transport members Rp, Rs, Ra and the transport time ta, as shown in FIG. 8B, the distance X2 from the detection position of the paper path sensors SN1 to SN4: X2 = V1 Xta is calculated and calculated, and the position of the downstream end of the recording sheet S in the conveyance direction is detected.

FIG. 9 is an explanatory diagram of the path length and the conveyance distance of the sheet feeding path according to the first exemplary embodiment. FIG. 9A illustrates the downstream end of the recording sheet in the conveyance direction at the position before passing the sheet feeding path sensor. FIG. 9B is an explanatory diagram of the recording sheet, and FIG. 9B is an explanatory diagram of the recording sheet in which the downstream end in the conveyance direction of the recording sheet remains in the conveyance path at a position after passing the paper feed path sensor and before passing the registration sensor.
C16: Path Length Storage Unit The path length storage unit C16 of the conveyance path SH stores path lengths Y1 to Y4 that are the lengths of the conveyance paths along the conveyance path SH. In FIG. 9, the path length storage unit C16 of the first exemplary embodiment is configured to feed the recording sheet S fed from the uppermost sheet feeding tray TR1 among the sheet feeding trays TR1 to TR4 in the dedicated path 1. The path length Y1 from the left end wall TR1a of the paper tray TR1 to the junction P5 and the path length Y2 from the detection position of the paper feed path sensor SN1 to the junction P5 are stored. In FIG. 9, the path length storage means C16 of the first embodiment supplies the recording sheets S fed from the lower three-stage sheet feeding trays TR2 to TR4 in the respective dedicated paths 2 to 4. The path length Y3 from the left end walls TR2a to TR4a of the paper trays TR2 to TR4 to the junction points P6 to P8 and the path length Y4 from the detection positions of the sheet feed path sensors SN2 to SN4 to the junction points P6 to P8 are stored. is doing.

C17: Driving Time Setting Unit The driving time setting unit C17 includes a conveyance distance calculation unit C17A and a conveyance time calculation unit C17B, and the exposure lengths L1 and L2 set by the exposure length setting unit C12. , L3, L4 and the position detected by the position calculation means C15, the remaining recording sheet S is conveyed from the position detected by the position calculation means C15 and is exposed to the exposure length L1. The driving time tb of the conveying members Rp to Ra until the exposure by the amount of L4 is set.
C17A: Transport Distance Calculation Unit The transport distance calculation unit C17A includes a transport distance calculation unit C17A1 before passing and a transport distance calculation unit C17A2 after passing, and is set by the exposure length setting unit C12. Based on the exposure lengths L1 to L4, the position detected by the position calculation means C15, and the path lengths Y1 to Y4 stored in the path length storage means C16, the remaining recording sheet S is Then, the conveyance distance Z1 of the recording sheet S from the position detected by the position calculating means C15 until it is exposed by the exposure lengths L1 to L4 is calculated.

C17A1: Means for calculating transport distance before passage The means for calculating C17A1 before transport as an example of the means for calculating the first transport distance has a downstream end in the transport direction passing through the detection positions of the sheet path sensors SN1 to SN4. The transport distance Z1 of the recording sheet S remaining in the paper feed path SH1 is calculated at a position before the start. In FIG. 9, the transport distance calculation means C17A1 before passing in the first embodiment is transported from the uppermost sheet feed tray TR1 and the position before the downstream end in the transport direction passes the detection position of the sheet feed path sensor SN1. For the remaining recording sheet S, the conveyance distance Z1: Z1 is obtained by adding the exposure lengths L1, L3 to the distance Y1-X1 until the downstream end in the conveyance direction reaches the junction P5. = Y1-X1 + L1, Y1-X1 + L3 Further, the transport distance calculation means C17A1 before passing in Example 1 is transported from the lower three paper feed trays TR2 to TR4, and the downstream end in the transport direction passes through the detection positions of the paper feed path sensors SN2 to SN4. For the recording sheet S remaining in the paper feed path SH1 at the previous position, the exposure lengths L2 and L4 are added to the distance Y3-X1 until the downstream end in the transport direction reaches the junctions P6 to P8. Is calculated as the transport distance Z1: Z1 = Y3-X1 + L2, Y3-X1 + L4.

C17A2: Post-passage transport distance calculation means The post-passage transport distance calculation means C17A2, as an example of the second transport distance calculation means, has its downstream end in the transport direction passing through the detection positions of the paper feed path sensors SN1 to SN4. In addition, the transport distance Z1 of the recording sheet S remaining in the sheet feed path SH1 at a position before passing the registration sensor SN5 is calculated. In FIG. 9, the transport distance calculation means C17A2 after passing in Example 1 is transported from the uppermost sheet feed tray TR1, the downstream end in the transport direction passes the detection position of the sheet feed path sensor SN1, and the registration sensor SN5. For the recording sheet S remaining in the paper feed path SH1 at a position before passing through the sheet, the transport distance Z1 is calculated as Z1 = Y2-X2 + L1, Y2-X2 + L3. The post-passage transport distance calculation means C17A2 is configured such that the recording sheet S is transported from the lower three paper feed trays TR2 to TR4, and the downstream end in the transport direction passes through the detection positions of the paper feed path sensors SN2 to SN4. For the recording sheet S remaining in the paper feed path SH1 at the position before passing the registration sensor SN5, the transport distance Z1 is calculated as Z1 = Y4-X2 + L2, Y4-X2 + L4.

  In addition, in the transport distance calculation means C17A2 of Example 1 after passing, the downstream end in the transport direction of the remaining recording sheet S passes through the junctions P5 to P8, and in the openable portion of the transport path SH. If the exposure lengths L1 to L4 have already been entered, that is, if the value of Z1 is negative, the transport distance Z1 is set to zero. Note that the transport distance calculation means C17A2 after the passage calculates the transport distance before the passage except that the corresponding distance value is different and that Z1 = 0 is set when the value of Z1 is negative. Since the same processing as that of the means C17A1 is performed, detailed description thereof is omitted.

C17B: Transport Time Calculation Means The transport time calculation means C17B is based on the transport distance Z1 calculated by the transport distance calculation means C17A and the transport speed V1 stored in the transport speed storage means C14. The drive time tb of the transport members Rp to Ra until the recording sheet S being transported from the position detected by the position calculation means C15 is exposed by the exposure lengths L1 to L4: tb = Z1 / V1 Is calculated.
C18: Opening detection means The opening detection means C18 detects whether or not the transport path SH has been opened based on the detection results of the cover sensors SN11, SN12, and SN13. When the cover sensors SN11, SN12, and SN13 detect that the lower cover U1a, the main cover U1b, and the reversing cover U4a are not held at the normal positions, the detection means for opening of the first embodiment is the lower cover U1a, It is detected that the conveyance path SH of the portion where the main cover U1b and the reverse cover U4a are arranged is opened. In particular, in the open detection means C18 of the first embodiment, when the cover sensors SN11 to SN13 detect a state where the covers U1a to U4a are not held at the normal position from a state where the covers U1a to U4a are held at the normal position. Then, it is detected that the conveyance path SH of the portion where the covers U1a to U4a are arranged is opened.

C19: Drive signal transmitting means when remaining The drive signal transmitting means C19 when remaining as an example of the drive control means when remaining is determined that the recording sheet S remains in the transport path SH and the transport path SH. Is determined to be released, the conveying members Rp, Rs, Ra are driven for the drive time tb set by the drive time setting means C17. In the first embodiment, when the recording sheet S is conveyed from the uppermost sheet feed tray TR1, the remaining drive signal transmission means C19 detects the remaining recording sheet S by the remaining detection means C8. When the opening detection means C18 determines that the transport path SH corresponding to the main cover U1b has been opened, the control signal is transmitted to the transport apparatus control means C6 and driven via the transport apparatus control means C6. During the time tb, the transport members Rp to Rs are driven.

  Further, when the recording sheet S is conveyed from the lower three stages of the paper feed trays TR2 to TR4, the remaining drive signal transmission means C19 of the first embodiment is the remaining detection signal C8. Is detected, and when the opening detection means C18 determines that the conveyance path SH corresponding to the lower cover U1a has been opened, the control signal is transmitted to the conveyance apparatus control means C6, and the conveyance apparatus control means The conveying members Rp to Rs are driven through the C6 for the driving time tb.

(Explanation of flowchart of Example 1)
Next, a flow of control in the printer U according to the first embodiment will be described with reference to a flowchart, a so-called flowchart.
(Description of flowchart of jam detection start process)
FIG. 10 is an explanatory diagram of a flowchart of jam detection start processing according to the first embodiment.
The processing of each step ST in the flowchart of FIG. 10 is performed according to a program stored in the control unit C of the printer U. This process is executed in parallel with other various processes of the printer U.
The flowchart shown in FIG. 10 is started when the printer U is turned on.

In ST1 of FIG. 10, it is determined whether or not the job has been started. If yes (Y), the process proceeds to ST2. If no (N), ST1 is repeated.
In ST2, it is determined whether or not the paper feed tray TR1 is used. If yes (Y), the process proceeds to ST3. If no (N), the process proceeds to ST7.
In ST3, it is determined whether or not a jam has occurred in the transport path SH, that is, whether or not a jam signal has been transmitted by a jam detection process described later. If yes (Y), the process returns to ST1, and if no (N), the process proceeds to ST4.
In ST4, it is determined whether or not the sheet feeding by the sheet feeding device Rp + Rs in the sheet feeding tray TR1 is started. If yes (Y), the process proceeds to ST5. If no (N), the process returns to ST3.
In ST5, a start signal for the jamming time measuring means C8B1 corresponding to the paper feed path sensor SN1 is transmitted. Then, the process proceeds to ST6.
In ST6, it is determined whether or not the job is finished. If yes (Y), the process returns to ST1, and if no (N), the process returns to ST3.

In ST7, it is determined whether or not the paper feed tray TR2 is used. If yes (Y), the process proceeds to ST8, and, if no (N), the process proceeds to ST12.
In ST8, it is determined whether or not a jam has occurred in the transport path SH, that is, whether or not a jam signal has been transmitted. If yes (Y), the process returns to ST1, and if no (N), the process proceeds to ST9.
In ST9, it is determined whether or not paper feeding by the paper feeding device Rp + Rs in the paper feeding tray TR2 has been started. If yes (Y), the process proceeds to ST10, and if no (N), the process returns to ST8.
In ST10, a start signal of the time measuring means C8B2 corresponding to the jam time sensor SN2 is transmitted. Then, the process proceeds to ST11.
In ST11, it is determined whether or not the job is finished. If yes (Y), the process returns to ST1, and if no (N), the process returns to ST8.

In ST12, it is determined whether or not the paper feed tray TR3 is used. If yes (Y), the process proceeds to ST13. If no (N), the process proceeds to ST17.
In ST13, it is determined whether or not a jam has occurred in the transport path SH, that is, whether or not a jam signal has been transmitted. If yes (Y), the process returns to ST1, and if no (N), the process proceeds to ST14.
In ST14, it is determined whether or not paper feeding by the paper feeding device Rp + Rs of the paper feeding tray TR3 has been started. If yes (Y), the process proceeds to ST15. If no (N), the process returns to ST13.
In ST15, a start signal of the jamming time measuring means C8B3 corresponding to the paper feed path sensor SN3 is transmitted. Then, the process proceeds to ST16.
In ST16, it is determined whether or not the job is finished. If yes (Y), the process returns to ST1, and if no (N), the process returns to ST13.

In ST17, it is determined whether or not a jam has occurred in the transport path SH, that is, whether or not a jam signal has been transmitted. If yes (Y), the process returns to ST1, and if no (N), the process proceeds to ST18.
In ST18, it is determined whether or not paper feeding by the paper feeding device Rp + Rs in the paper feeding tray TR4 has been started. If yes (Y), the process proceeds to ST19, and, if no (N), the process returns to ST17.
In ST19, a start signal of the jamming time measuring means C8B4 corresponding to the paper feed path sensor SN4 is transmitted. Then, the process proceeds to ST20.
In ST20, it is determined whether or not the job is finished. If yes (Y), the process returns to ST1, and if no (N), the process returns to ST17.

(Description of flowchart of first jam detection process)
FIG. 11 is an explanatory diagram of a flowchart of first jam detection processing according to the first embodiment.
The processing of each step ST in the flowchart of FIG. 11 is performed according to a program stored in the control unit C of the printer U. This process is executed in parallel with other various processes of the printer U.
The first jam detection process is executed in parallel for each jamming time measuring means C8B1 to C8B4, C8B6, and C8B8 corresponding to the sensors SN1 to SN4, SN6, and SN8. The first jam detection process corresponds to jam detection times t1 to t4, t6, and t8 and sensors SN5 and SN8 on the downstream side in the transport direction according to the jam time measuring means C8B1 to C8B4, C8B6, and C8B8. Since all the same processing is performed except that the jamming time measuring means C8B5, C8B8, etc. are different from each other, the first jam detecting process of the jamming time measuring means C8B1 will be described below, and the jamming time measuring means C8B2- The description of the first jam detection process of C8B4, C8B6, and C8B8 is omitted.
The flowchart shown in FIG. 11 is started when the printer U is powered on.

In ST31 of FIG. 11, it is determined whether or not the start signal of the time measuring means C8B1 of the jam time of the paper feed path sensor SN1 is transmitted. If yes (Y), the process proceeds to ST32. If no (N), ST31 is repeated.
In ST32, the jam determination time t1 is set in the jamming time measuring means C8B1. Then, the process proceeds to ST33.
In ST33, it is determined whether or not a jam determination time t1 has elapsed, that is, whether or not the jam determination time t1 has expired. If yes (Y), the process proceeds to ST36, and, if no (N), the process proceeds to ST34.
In ST34, it is determined whether or not the downstream end in the conveyance direction of the recording sheet S has passed the detection position of the sensor SN1. If yes (Y), the process proceeds to ST35, and, if no (N), the process returns to ST33.
In ST35, a start signal of the time measuring means for jam time corresponding to the sensor on the downstream side in the transport direction is transmitted. That is, when the time is measured by the jamming time measuring means C8B1 corresponding to the paper feed path sensor SN1, the jamming time measuring means C8B5 corresponding to the registration sensor SN5 on the downstream side in the transport direction of the paper feeding path sensor SN1 is started. Send a signal. Then, the process returns to ST31.
In ST36, a jam signal is transmitted. Then, the process returns to ST31.

(Description of flowchart of second jam detection process)
FIG. 12 is an explanatory diagram of a flowchart of second jam detection processing according to the first embodiment.
12 is performed according to a program stored in the control unit C of the printer U. This process is executed in parallel with other various processes of the printer U.
The second jam detection process is executed according to the jamming time measuring means C8B5 corresponding to the registration sensor SN5. The second jam detection process is different from the first jam detection process in the following points, but in step ST having the same sign as the first jam detection process, the corresponding jam determination times t5 and t9, Similar processing is performed only in the time counting means C8B5 and the like. Therefore, in the following, only step STs with different codes will be described, and detailed description of steps ST with the same codes will be omitted.
In the second jam detection process of FIG. 12, ST41 to ST49 are executed instead of ST32 of the first jam detection process. In the second jam detection process, ST51 to ST55 are executed instead of ST35 of the first detection process.

In ST41 of FIG. 12, it is determined whether or not a start signal is transmitted by passage of the paper feed path sensor SN1. If yes (Y), the process proceeds to ST42, and, if no (N), the process proceeds to ST43.
In ST42, a time t5 from the passage through the paper feed path sensor SN1 to the passage through the registration sensor SN5 is set in the jamming time measuring means C8B5. Then, the process proceeds to ST33.
In ST43, it is determined whether or not a start signal is transmitted by passage through the paper feed path sensor SN2. If yes (Y), the process proceeds to ST44, and, if no (N), the process proceeds to ST45.
In ST44, the time t5 from the passage through the paper feed path sensor SN2 to the passage through the registration sensor SN5 is set in the jamming time measuring means C8B5. Then, the process proceeds to ST33.

In ST45, it is determined whether or not a start signal is transmitted by passage through the paper feed path sensor SN3. If yes (Y), the process proceeds to ST46, and, if no (N), the process proceeds to ST47.
In ST46, a time t5 from passing through the paper feed path sensor SN3 to passing through the registration sensor SN5 is set in the jamming time measuring means C8B5. Then, the process proceeds to ST33.
In ST47, it is determined whether or not a start signal is transmitted by passage through the paper feed path sensor SN4. If yes (Y), the process proceeds to ST48, and, if no (N), the process proceeds to ST49.
In ST48, a time t5 from the passage through the paper feed path sensor SN4 to the passage through the registration sensor SN5 is set in the jamming time measuring means C8B5. Then, the process proceeds to ST33.
In ST49, a time t9 from passing through the reverse path sensor SN7 to passing through the registration sensor SN5 is set in the jamming time measuring means C8B5. Then, the process proceeds to ST33.

In ST51 of FIG. 12, it is determined whether or not double-sided printing is set. If yes (Y), the process proceeds to ST52, and, if no (N), the process proceeds to ST54.
In ST52, it is determined whether or not an image has been recorded on one side of the recording sheet S, that is, whether or not the time t9 is set in the jamming time measuring means C8B5. If yes (Y), the process proceeds to ST54, and, if no (N), the process proceeds to ST53.
In ST53, the start signal of the time measuring means C8B6 of the jam time of the connection path sensor SN6 is transmitted. Then, the process returns to ST31.
In ST54, it is determined whether or not the discharge destination is set to the discharge tray TRh. If yes (Y), the process proceeds to ST55, and, if no (N), the process proceeds to ST53.
In ST55, the start signal of the time measuring means C8B9 for the jam time of the discharge sensor SNh is transmitted. Then, the process returns to ST31.

(Description of flowchart of third jam detection process)
FIG. 13 is an explanatory diagram of a third jam detection process according to the first embodiment.
13 is performed according to a program stored in the control unit C of the printer U. This process is executed in parallel with other various processes of the printer U.
The third jam detection process is executed according to the jamming time measuring means C8B7 corresponding to the common path sensor SN7. The third jam detection process is different from the first jam detection process in the following points, but in step ST having the same sign as the first jam detection process, the corresponding jam determination time t7 and the jam time The same processing is performed only in the timing means C8B7 and the like. Therefore, in the following, only step STs with different codes will be described, and detailed description of steps ST with the same codes will be omitted.
In the third jam detection process of FIG. 13, ST61 to ST66 are executed instead of ST35 of the first jam detection process.

In ST61 in FIG. 13, it is determined whether or not double-sided printing is set. If yes (Y), the process proceeds to ST62, and, if no (N), the process proceeds to ST64.
In ST62, it is determined whether images have been recorded on both sides of the recording sheet S. If yes (Y), the process proceeds to ST64, and, if no (N), the process proceeds to ST63.
In ST63, the start signal of the time measuring means C8B8 corresponding to the reverse path sensor SN8 is transmitted. Then, the process returns to ST31.
In ST64, it is determined whether or not the discharge destination is set to the face-down tray TRh2. If yes (Y), the process proceeds to ST65, and, if no (N), the process proceeds to ST66.
In ST65, the start signal of the time measuring means C8B10 corresponding to the discharge sensor SNh2 is transmitted. Then, the process returns to ST31.
In ST66, the start signal of the jamming time measuring means C8B11 corresponding to the discharge sensor SNh3 is transmitted. Then, the process returns to ST31.

(Description of flowchart of fourth jam detection process)
FIG. 14 is an explanatory diagram of a flowchart of the fourth jam detection process according to the first embodiment.
14 is performed according to a program stored in the control unit C of the printer U. This process is executed in parallel with other various processes of the printer U.
The fourth jam detection process is executed according to jamming time measuring means C8B9 to C8B11 corresponding to the discharge sensors SNh to SNh3. The fourth jam detection process differs from the first jam detection process in the following points, but in step ST having the same sign as the first jam detection process, the corresponding jam determination times t10 to t12, Similar processing is performed only in the time counting means C8B9 to C8B11. Accordingly, only different parts will be described below, and detailed description of step ST with the same reference numerals will be omitted. In the following, the fourth jam detection process of the jam time measuring means C8B9 will be described, and the description of the fourth jam detection process of the jam time measuring means C8B10 and C8B11 will be omitted.
In FIG. 14, in the fourth jam detection process, ST35 of the first jam detection process is omitted. That is, in ST34 of FIG. 14, if yes (Y), the process returns to ST31, and if no (N), the process returns to ST33.

(Explanation of flowchart of drive time setting process)
FIG. 15 is an explanatory diagram of a flowchart of a drive time setting process according to the first embodiment.
FIG. 16 is a continuation of FIG. 15 and is an explanatory diagram of a flowchart of the drive time setting process according to the first embodiment.
The processing of each step ST in the flowcharts of FIGS. 15 and 16 is performed according to a program stored in the control unit C of the printer U. This process is executed in parallel with other various processes of the printer U.
The flowcharts shown in FIGS. 15 and 16 are started when the printer U is turned on.

In ST101 of FIG. 15, it is determined whether or not the job has been started. If yes (Y), the process proceeds to ST102, and if no (N), ST101 is repeated.
In ST102, it is determined whether or not paper is fed from the uppermost paper feed tray TR1. If yes (Y), the process proceeds to ST103, and if no (N), the process proceeds to ST123 in FIG.
In ST103, it is determined whether or not the difference S1-H1 between the sheet length S1 and the reference holding length H1 is longer than the reference exposure length L1. If yes (Y), the process proceeds to ST104, and, if no (N), the process proceeds to ST105.
In ST104, the difference S1-H1 (= L3) is set as the exposure length. Then, the process proceeds to ST106.
In ST105, the reference exposure length L1 is set as the exposure length. Then, the process proceeds to ST106.

In ST106, it is determined whether or not paper feeding by the paper feeding device Rp + Rs in the paper feeding tray TR1 has been started. If yes (Y), the process proceeds to ST107, and if no (N), ST106 is repeated.
In ST107, the measurement of the conveyance time ta after feeding is started. Then, the process proceeds to ST108.
In ST108, it is determined whether or not a jam has occurred in the transport path SH, that is, whether or not a jam signal has been transmitted. If yes (Y), the process proceeds to ST109, and, if no (N), the process proceeds to ST112.
In ST109, the measurement of the conveyance time ta after feeding is completed. Then, the process proceeds to ST110.
In ST110, the transport distance X1 from the left end wall TR1a of the paper feed tray TR1 is calculated. Then, the process proceeds to ST111.

In ST111, the drive time tb is calculated and set based on the exposure lengths L1 and L3, the transport distance X1, the distance Y1 from the left end wall TR1a of the paper feed tray TR1 to the junction P5, and the transport speed V1. . Then, the process proceeds to ST119.
In ST112, it is determined whether or not the downstream end in the conveyance direction of the recording sheet S has passed the detection position of the paper feed path sensor SN1. If yes (Y), the process proceeds to ST113, and, if no (N), the process returns to ST108.
In ST113, the measurement of the conveyance time ta after passing the paper feed path sensor SN1 is started. Then, the process proceeds to ST114.
In ST114, it is determined whether or not a jam has occurred in the transport path SH, that is, whether or not a jam signal has been transmitted. If yes (Y), the process proceeds to ST115, and, if no (N), the process proceeds to ST118.

In ST115, the measurement of the conveyance time ta after passing the detection position of the paper feed path sensor SN1 is ended. Then, the process proceeds to ST116.
In ST116, the transport distance X2 from the detection position of the paper feed path sensor SN1 is calculated. Then, the process proceeds to ST117.
In ST117, the drive time tb is calculated based on the exposure lengths L1 and L3, the transport distance X2, the distance Y2 from the detection position of the paper feed path sensor SN1 to the junction P5, and the transport speed V1 of the transport member. To set. Then, the process proceeds to ST119.
In ST118, it is determined whether or not the downstream end in the conveyance direction of the recording sheet S has passed the detection position of the registration sensor SN5. If yes (Y), the process proceeds to ST119, and, if no (N), the process returns to ST114.
In ST119, it is determined whether or not the job is finished. If yes (Y), the process returns to ST101, and, if no (N), the process returns to ST106.

  In ST123 to ST139 in FIG. 16, the reference exposure length L2 is used instead of the reference exposure length L1, the reference holding length H2 is used instead of the reference holding length H1, and the difference S1-H1 (= L3) is set. Instead, the difference S1-H2 (= L4) is used, and the distance Y1 from the left end wall TR1a of the paper feed tray TR1 to the junction P5 is changed to the junction points P6 to P8 from the left end walls TR2a to TR4a of the paper feed trays TR2 to TR4. And using the distance Y4 from the detection positions of the paper feed path sensors SN2 to SN4 to the junctions P6 to P8 instead of the distance Y2 from the detection position of the paper feed path sensor SN1 to the junction P5, etc. ST103-S, which is a process for the recording sheet S fed from the paper feed tray TR1, except that the process is for the recording sheet S fed from the paper feed trays TR2-TR4. Since the same processing as 119, detailed description thereof will be omitted.

(Explanation of flowchart of driving process when remaining)
FIG. 17 is an explanatory diagram of a flowchart of the driving process at the time of remaining in the first embodiment.
The processing of each step ST in the flowchart of FIG. 17 is performed according to a program stored in the control unit C of the printer U. This process is executed in parallel with other various processes of the printer U.
The flowchart shown in FIG. 17 is started when the printer U is powered on.

In ST201 in FIG. 17, it is determined whether or not the job has been started. If yes (Y), the process proceeds to ST202, and if no (N), ST201 is repeated.
In ST202, it is determined whether a jam has occurred in the transport path SH, that is, whether a jam signal has been transmitted. If yes (Y), the process proceeds to ST204, and, if no (N), the process proceeds to ST203.
In ST203, it is determined whether or not the job is finished. If yes (Y), the process returns to ST201, and if no (N), the process returns to ST202.
In ST204, it is determined whether or not paper has been fed from the uppermost paper feed tray TR1. If yes (Y), the process proceeds to ST205, and, if no (N), the process proceeds to ST206.

In ST205, it is determined whether or not the main cover U1b is opened, that is, whether or not the main cover U1a is not held in the normal position. If yes (Y), the process proceeds to ST207, and if no (N), ST205 is repeated.
In ST206, it is determined whether or not the lower cover U1a is opened, that is, whether or not the lower cover U1a is held in the normal position. If yes (Y), the process proceeds to ST207, and if no (N), ST206 is repeated.
In ST207, the transport members Rp to Rs are driven for the drive time tb. Then, the process returns to ST201.

(Operation of Example 1)
In the printer U according to the first embodiment having the above-described configuration, the recording sheet S is conveyed by an image forming operation according to the number of prints, duplex printing setting, and the like, and an image is recorded on the recording sheet S. The recording sheet S is discharged to TRh to TRh3. At this time, the jam detection start process, the first jam detection process to the fourth jam detection process, and the like according to the first exemplary embodiment are performed, and the recording sheet S is placed in any one of the transport paths SH during the image forming operation. When clogged, one of the times t1 to t12 is timed up, and it is determined that a jam has occurred in the transport path SH. When it is determined that a jam has occurred, the conveyance of the recording sheet S by the medium conveyance device BHS is stopped, and the recording sheet S remains in the conveyance path SH.

  In the printer U according to the first embodiment, when the recording sheet S remains on the dedicated paths 1 to 2 and the corresponding covers U1b and U1a are opened, the remaining time driving process shown in FIG. Thus, the transport members Rp to Ra are driven during the drive time tb set by the drive time setting process of FIGS. 15 and 16. That is, in the printer U according to the first exemplary embodiment, when the covers U1b and U1a are opened in a state where the recording sheet S remains in the dedicated paths 1 to 2, the remaining recording sheet S is transferred to the transport path. Control is carried out so that the sheet is conveyed to the opened part of SH and exposed to the outside.

Here, in the conventional technique, after a jam is detected in the conveyance path, conveyance control of the remaining recording sheet is performed in a state where the cover is closed and the conveyance path is closed. Therefore, even if the remaining recording sheet is conveyed to the position of the cover, it is necessary to pull out the recording sheet from the conveying path after the cover is released, and the remaining recording sheet is torn when the recording sheet is pulled out. In other words, it was difficult to remove the remaining recording sheet.
On the other hand, in the printer U according to the first embodiment, when the covers U1b and U1a are opened, the remaining recording sheet S is transported to the opened portion of the transport path SH and remains. The sheet S is sent out from the opened part and exposed. Accordingly, the operator can easily recognize the remaining recording sheet S exposed from the opened portion, and can easily grasp and pull the exposed portion of the remaining recording sheet S, compared with the conventional configuration. Thus, the remaining recording sheet S can be easily removed.

Further, in the prior art, the remaining recording sheet is conveyed by driving the conveying member for a certain driving time without changing the driving time based on the position of the downstream end in the conveying direction of the recording sheet. Therefore, the position of the recording sheet after conveyance differs depending on the position of the recording sheet when remaining. Therefore, if the conventional configuration is applied and the covers U1a and U1b are opened, the remaining recording sheet S may be configured to drive the conveying members Rp to Ra for a certain driving time. When the toner is conveyed, depending on the position of the recording sheet S when it remains, it may be hardly exposed from the opened portion, and the removal operation may be difficult.
On the other hand, in the actual printer U of Example 1, the drive time tb is set based on the position of the downstream end of the recording sheet S in the conveyance direction, the exposure lengths L1 to L4, and the like. Further, the control is performed to reliably send a predetermined amount or more to the outside as compared with the configuration in which the conveying member is driven for a certain driving time without being based on the position of the downstream end of the recording sheet in the conveying direction. Therefore, the recording sheet S is surely exposed from the opened part, and a part to be grasped by the operator is secured, so that the recording sheet S can be easily removed.

In particular, in the first embodiment, the exposure lengths L1 to L4 of the recording sheet S are set based on the sheet length S1, the reference exposure lengths L1 and L2, and the reference holding lengths H1 and H2. Based on the exposed lengths L1 to L4 and the position of the downstream end of the recording sheet S in the conveying direction, the driving time tb of the conveying member is set, and the remaining recording sheet S is conveyed.
That is, in the first embodiment, the difference S1-H1 and S1-H2 between the sheet length S1 and the reference holding lengths H1 and H2 are set to the reference exposure length L1 by the drive time setting process of FIGS. , L2 or less, the reference exposure lengths L1, L2 are set as the exposure length, and the drive time tb is set. When the difference S1-H1, S1-H2 between the sheet length S1 and the reference holding lengths H1, H2 is longer than the reference exposure lengths L1, L2, the difference S1-H1 ( = L3) and S1-H2 (= L4) are set, and the driving time tb is set so that the holding length becomes the reference holding lengths H1 and H2.

Therefore, in the first embodiment, the exposure lengths L1 to L4 that are greater than the reference exposure lengths L1 and L2 are set, and the drive time tb of the conveying member is set, so that the exposed portion of the recording sheet S is not too short. The transport members Rp to Ra are controlled. Therefore, compared with the case where the exposure lengths less than the reference exposure lengths L1 and L2 are set, it is possible to reduce the deterioration of workability of the remaining recording sheet S. In addition, in the first embodiment, when the differences S1-H1 and S1-H2 are longer than the reference exposure lengths L1 and L2, the exposure length is set so that the holding length becomes the reference holding lengths H1 and H2. L3 and L4 are set and the drive time tb is set. Therefore, when the remaining recording sheet S is conveyed and exposed, the remaining recording sheet S is hardly left in the conveying path SH even if the sheet length S1 is long, and the remaining recording sheet S is easily pulled out from the conveying path SH. . Further, at this time, the exposed recording sheet S is in a state in which the upstream end portion in the transport direction is sandwiched by the closest transport members Ra and Rs on the upstream side in the transport direction from the opened portion of the transport path SH. Even if the exposed portion of the recording sheet S becomes longer and heavier, it is difficult to fall out of the conveying path SH and is less likely to fall and scatter.
Therefore, in particular, in Example 1, the workability of the removal operation of the remaining recording sheet S is improved while ensuring the minimum exposure length, and the recording sheet S is removed as compared with the conventional configuration. Work is easy.

  Next, the printer U according to the second embodiment of the present invention will be described. In the description of the second embodiment, the same reference numerals are given to the components corresponding to the components of the first embodiment, and the details thereof will be described. Description is omitted. The second embodiment is different from the first embodiment in the following points, but is configured in the same manner as the first embodiment in other points.

(Description of the control part C of Example 2)
FIG. 18 is a diagram corresponding to FIG. 5 of the first embodiment, and is a block diagram of the control unit of the printer of the second embodiment of the present invention.
FIG. 19 is a block diagram continued from FIG.
18 and 19, the control unit C of the printer U according to the second embodiment omits the holding length storage unit C10 and the sheet length determination unit C11 in the control unit C of the printer U according to the first embodiment. . The control unit C of the printer U according to the second embodiment replaces the exposure length storage unit C9 and the exposure length setting unit C12 according to the first embodiment, and sets the exposure length storage unit C9 ′ and the exposure length. Means C12 '.

(Function of control unit C)
C9 ′: Exposure Length Storage Unit The exposure length recording unit C9 ′ of the second embodiment includes a first exposure length storage unit C9A ′ and a second exposure length storage unit C9B ′, and a recording sheet. The exposure lengths L11 to L22 and L11 ′ to L22 ′ set in advance according to the type of S are stored.
C9A ′: First exposure length storage means The first exposure length storage means C9A ′ is preset according to the type of the recording sheet S with respect to the exposure length when paper is fed from the paper feed tray TR1. The exposure lengths L11 to L22 are stored.

FIG. 20 is an explanatory diagram illustrating an example of an exposure length reference value stored in the exposure length storage unit according to the second embodiment, and FIG. 20A is an explanatory diagram regarding the exposure length fed from the uppermost sheet feed tray. FIG. 20B is an explanatory view of the exposure length fed from the lower three stages of paper feed trays.
In FIG. 20A, in Example 2, the storage means C9A ′ for the first exposure length feeds the A3 short side of the thick paper, that is, L11 as the exposure length of the A3SEF of the thick paper, L12 as the exposure length of the A4SEF of the thick paper, L13 is stored as an A4 LEF exposure length of thick paper, that is, an exposure length of A4LEF of thick paper, and L14 is stored as an exposure length of other lengths of thick paper. Also, in FIG. 20A, the first exposure length storage means C9A ′ in Example 2 uses L15 as the exposure length of plain paper A3SEF, L16 as the exposure length of plain paper A4SEF, and exposure of plain paper A4LEF. L17 is stored as the length, and L18 is stored as the exposure length of the other length of plain paper. Further, in FIG. 20A, the storage means C9A ′ for the first exposure length of Example 2 uses L19 as the exposure length of thin paper A3SEF, L20 as the exposure length of thin paper A4SEF, and L21 as the exposure length of thin paper A4LEF. Is stored as the exposure length of other sheet lengths of thin paper.

  In the second embodiment, the exposure methods L11 to L13 of the thick paper A3SEF to A4LEF are based on the sheet length S1, the reference exposure length L2, and the reference holding length H2, and the same method as in the first embodiment. The exposure length S1-H1 (= L3) calculated in advance is set. Further, in the second embodiment, as the exposure lengths L15 to L17 of A3SEF to A4LEF of plain paper, based on the A4LEF sheet length S1, the reference exposure length L2, and the reference holding length H2, An exposure length S1-H1 (= L3) calculated in advance by the same method is set. Further, in Example 2, the exposure lengths L19 to L21 of thin paper A3SEF to A4LEF and the other exposure lengths L14, L18, and L22 other than A3SEF to A4LEF of thick paper, plain paper, and thin paper are used as the reference exposure length L1. Is set. In the second embodiment, L11> L12> L13> L1.

C9B ′: Second Exposure Length Storage Unit The second exposure length storage unit C9B ′ previously sets the exposure length when paper is fed from the paper feed trays TR2 to TR4 according to the type of the recording sheet S. The exposed exposure lengths L11 'to L22' are stored. In FIG. 20B, the second exposed length storage means C9B ′ of the second embodiment is similar to the first exposed length storage means C9A ′ in the recording sheets S of thick paper, plain paper, and thin paper. , Exposure lengths L11 ′ to L22 ′ are stored for A3SEF, A4SEF, A4LEF, and other lengths. In the second embodiment, the exposure lengths L11 ′ to L22 ′ are set to values corresponding to the case where paper is fed from the paper feed trays TR2 to TR4, and the reference exposure length L1 and the reference holding length H1. In place of the above, corresponding to the exposure lengths L11 to L22 stored in the first exposure length storage means C9A ′, except that the calculation is based on the reference exposure length L2 and the reference holding length H2. Since it is calculated similarly, the detailed description thereof is omitted.

C12 ′: Exposure length setting means The exposure length setting means C12 ′ is the type of the recording sheet S remaining in the conveyance path SH and the exposure lengths L11 to L22, L11 stored in the exposure length storage means C9 ′. The exposure length is set based on ′ to L22 ′. The exposure length setting means C12 ′ of the second embodiment is based on the types of the paper feed trays TR1 to TR4 stored in the type storage means C4 and the paper feed trays TR1 to TR4 set by the tray setting means C5. The type of the recording sheet S is specified, and the exposure lengths L11 to L22 and L11 ′ to L22 ′ of the corresponding type of the recording sheet S are set.

(Explanation of flowchart of Example 2)
Next, a processing flow of the image forming apparatus U according to the second exemplary embodiment of the present invention will be described with reference to a flowchart.
The jam detection start process, the first jam detection process to the fourth jam detection process, and the remaining drive process are the same as those in the first embodiment, and thus detailed description thereof is omitted.
(Description of Flowchart of Setting Process of Driving Time in Example 2)
FIG. 21 is an explanatory diagram of a flowchart corresponding to FIG. 15 of the first embodiment, and is a flowchart of a drive time setting process according to the second embodiment of the present invention.
FIG. 22 is an explanatory diagram of a flowchart continued from FIG.
21 and 22, in the flowchart of the drive time setting process of the second embodiment, ST301 is executed instead of ST103 to ST105 in the flowchart of the drive time setting process of the first embodiment. In the driving time setting process flowchart of the second embodiment, ST302 to ST306 are executed instead of ST123 to ST125 of the driving time setting process flowchart of the first embodiment. Since other ST101, ST106 to ST119, ST126 to ST139 are the same as those in the first embodiment, detailed description thereof is omitted.

In ST301 in FIG. 21, the exposure lengths L11 to L22 are set according to the type of the recording sheet S stored in the paper feed tray TR1. Then, the process proceeds to ST106.
In ST302 of FIG. 22, it is determined whether or not paper is fed from the paper feed tray TR2. If yes (Y), the process proceeds to ST303, and, if no (N), the process proceeds to ST304.
In ST303, the exposure lengths L11 ′ to L22 ′ are set according to the type of the recording sheet S stored in the paper feed tray TR1. Then, the process proceeds to ST126.
In ST304, it is determined whether or not paper is fed from the paper feed tray TR3. If yes (Y), the process proceeds to ST305, and, if no (N), the process proceeds to ST306.
In ST305, the exposure lengths L11 ′ to L22 ′ are set according to the type of the recording sheet S stored in the paper feed tray TR1. Then, the process proceeds to ST126.
In ST306, the exposure lengths L11 ′ to L22 ′ are set according to the type of the recording sheet S stored in the paper feed tray TR1. Then, the process proceeds to ST126.
(Operation of Example 2)
FIG. 23 is a diagram for explaining the operation of the second embodiment, and is a diagram for explaining the case where the remaining thin paper is exposed.
In the printer U according to the second embodiment having the above-described configuration, the exposure lengths L11 to L22 and L11 ′ to L22 ′ are stored in advance based on the type of the recording sheet S, that is, the type of recording sheet such as the paper type and the sheet length S1. The conveyance member drive time tb is set based on the so-called look-up table and the position of the recording sheet S. That is, in Example 2, the drive time tb is set based on the type of the recording sheet S, and when the covers U1b and U1a are opened, the remaining recording sheet S is opened in the conveyance path SH. Control is performed so that the exposed portion is exposed to the outside. Accordingly, in the second embodiment, as in the first embodiment, it is easy to remove the remaining recording sheet S.
In the second embodiment, the exposure lengths L11 to L22 and L11 ′ to L22 ′ are set to be shorter as the paper thickness is thinner. Therefore, when the exposure length is long, as shown by the broken line in FIG. 23, even the recording sheet S in which the exposed portion hangs down is exposed in a state where the exposure length is short, like the recording sheet S shown by the solid line in FIG. In addition, the exposed portion of the recording sheet S is unlikely to hang down, and a so-called “high” state is easily maintained. Therefore, for example, when the movable range of the covers U1b and U1a is narrow and it is difficult for the operator to work only from above, the operator's hand can easily reach the exposed recording sheet S, and the recording sheet S can be removed. Improved.

(Example of change)
As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various change is performed within the range of the summary of this invention described in the claim. It is possible. Modification examples (H01) to (H09) of the present invention are exemplified below.
(H01) In each of the above embodiments, a printer as an example of an image forming apparatus has been illustrated. However, the present invention is not limited to this, and a FAX, a copying machine, or a multifunction machine having all or a plurality of functions can be used. is there. In the above-described embodiment, the configuration of the so-called electrophotographic system has been exemplified as the configuration of the image forming apparatus. .

(H02) In each of the embodiments, the recording sheet S remaining in the dedicated paths 1 to 4 is exemplified as the recording sheet S that is conveyed and exposed. However, the recording sheet S is not limited to this, and can be opened and closed. The present invention is applicable to any configuration having the above, and a configuration in which an arbitrary recording sheet S remaining in the conveyance path SH is exposed is possible. Accordingly, for example, in the configuration of the embodiment, when the recording sheet S remains in the upstream inversion path SH8b, the recording sheet remaining from the main inversion path SH8a opened by the inversion cover U4a is exposed. Is possible. Further, the recording sheet S fed from the lower three-stage paper feed trays TR2 to TR4 and remaining in the dedicated paths 2 to 4 is opened by the main cover U1b, not by the portion opened by the lower cover U1a. It is also possible to have a configuration in which the part is exposed from the part of the transport path SH that is opened or the part of the transport path SH that is opened by the reversing cover U4a. Furthermore, when the conveying member is configured to be able to rotate in the reverse direction, the recording sheet S that has passed through the opened portion of the conveying path and remains on the downstream side is reversely conveyed toward the upstream side, A configuration in which the exposed portion of the conveyance path is exposed is also possible.

(H03) In each of the embodiments, the recording sheet S fed from the uppermost sheet feed tray TR1 and remaining in the dedicated path 1 is based on the reference exposure length L1 and the reference holding length H1. The exposure lengths L1, L3, L11 to L22 are set, and for the recording sheet S fed from the lower three stages of paper feed trays TR2 to TR4 and remaining in the dedicated paths 2 to 4, the reference exposure length L2 is set. The exposure lengths L2, L4, L11 ′ to L22 ′ are set based on the reference holding length H2, and the reference exposure lengths L1, L2, the reference holding lengths H1, H2, etc. Although the structure which uses properly according to the structure of 2-4 is desirable, it is not limited to this. For example, a common value can be used for the reference exposure length and the reference holding length regardless of the configurations of the conveyance paths 1 to 2 in which the recording sheet S remains.

(H04) In the second embodiment, the configuration of the exposure lengths L11 to L22 and L11 ′ to L22 ′ is exemplified such that the exposure length is shortened when the paper thickness as an example of the type of the recording sheet S is thin. However, the exposure lengths L11 to L22 and L11 ′ to L22 ′ can be arbitrarily set based on the type of the recording sheet S. For example, if the paper is thin and easily torn during removal, the exposed length is set longer so that the holding length is shorter, or the exposed portion is less likely to sag because the paper is thicker and stronger. If the center of gravity is difficult to fall stably even if it is not sandwiched between the transport members Rp to Rs, the exposure length L11 to L22, L11 set in the lookup table, such as setting the exposure length so as to expose as much as possible. ′ To L22 ′ can be arbitrarily set according to the configuration of the printer U, the configuration of the medium conveyance device BHS, and the like.

(H05) In each of the embodiments described above, the common reference exposure length L2 for the recording sheets S fed from the lower three feed trays TR2 to TR4 and remaining in the dedicated paths 2 to 4 is used. Although the configuration in which the exposure lengths L2, L4, L11 ′ to L22 ′ are set based on the reference holding length H2 is exemplified, the present invention is not limited to this. For example, in the dedicated paths 2 to 4, the junction points P <b> 6, P <b> 7, and P <b> 8 with the upstream merge path 6 are lower in the order of the dedicated paths 2, 3, 4, and in the order of the dedicated paths 2, 3, 4, Since the recording sheet S is easily exposed at a low position, the exposure length of the lower dedicated path is set longer than the upper dedicated path so that the recording sheet S can be easily taken out even if the operator is not bent much. For example, the reference exposure length and the reference exposure length can be properly used for each of the dedicated paths 2 to 4.

(H06) In each of the above embodiments, as an example of the drive control means at the time of remaining, a configuration in which the drive of the transport members Rp to Ra is controlled via the transport device control means C6 by the drive signal C19 at the time of remaining drive is illustrated. However, the present invention is not limited to this, and a configuration in which driving of the transport members Rp to Ra is directly controlled without using the transport device control unit C6 is also possible.
(H07) In each of the above embodiments, it is detected that a jam has occurred in the conveyance path SH when the recording sheet S does not pass the detection positions of the sensors SN1 to SN8 and SNh to SHh3 within the expected time t1 to t12. However, the configuration for detecting a jam is not limited to this. For example, when the recording sheet S is detected by the sensor continuously for a certain time or more, a configuration for detecting that a jam has occurred, or the configuration of this embodiment, and the recording sheet S is detected by the sensor for a certain time continuously. A conventionally known configuration for detecting jamming, such as a combination of the configurations in the case of being applied, can be applied.

(H08) In each of the above embodiments, the position calculating means as an example of the position detecting means calculates and calculates the transport distances X1 and X2 based on the transport speed V1 and the transport time ta, and the remaining recording sheet S Although the structure which detects a position was illustrated, it is not limited to this. For example, a configuration in which a plurality of sensors are installed along the conveyance path and the position of the remaining recording sheet S is detected depending on whether or not the sensors are detected is also possible.
(H09) In each of the above embodiments, the reversing unit U4 and the optional discharge unit U3 can be omitted, and conversely, the present invention can also be applied to an image forming apparatus provided with a plurality of optional discharge units U3.

11, 16, 18 ... 1st guide part,
12, 17, 19 ... second guide,
BHS: Medium transport device,
C4: Kind storage means, length storage means,
C7: Passing detection means,
C8: means for detecting residuals,
C9, C9 '... means for storing exposure length,
C10: Retention length storage means,
C11: Length determining means,
C12, C12 '... exposure length setting means,
C13: means for measuring the conveyance time,
C15 ... position detecting means,
C17: Driving time setting means,
C18 ... Opening detection means,
C19: Drive control means,
H1, H2 ... Standard holding length, holding length,
L1, L2 ... Standard exposure length, exposure length,
L3, L4, L11 to L22, L11 ′ to L22 ′... Exposure length,
Ra, Rs, Rp, Rr, Rh to Rh3 ... conveying member,
Rp ... extraction member,
S ... medium
S1... Length in the medium transport direction,
SH, SH1 to SH8, 1 to 7 ... conveying path,
ta ... transport time,
tb: drive time of the conveying member,
TR1 to TR4 ... accommodating portion,
U: Image forming apparatus,
Uy to Uk + BM + T2 + F... Image recording unit.

Claims (6)

A transport path through which the medium is transported;
A transport member provided in the transport path for transporting the medium;
A first guide unit arranged on the transport path and capable of guiding the medium;
A second guide unit arranged on the transport path and capable of guiding the medium, a transport position capable of transporting the medium to and from the first guide unit opposite the first guide unit; The second guide part movably provided between an open position that opens the conveyance path to the outside;
An opening detecting means for detecting whether or not the conveying path is opened;
Detecting the presence or absence of a medium in the transport path and detecting whether or not the medium remains in the transport path;
Drive control means for controlling the drive of the transport member, wherein when it is determined that a medium remains in the transport path and it is determined that the transport path is opened, the transport member is driven to perform the transport The drive control means for transporting the medium remaining in the path to an open part of the transport path;
A medium carrying device comprising: Position detecting means for detecting the position of the remaining medium in the transport path;
Exposure length storage means for storing an exposure length that is a length set in advance as a length for exposing a part of the remaining medium from an open portion of the transport path;
Based on the exposure length and the position detected by the position detection means, the remaining medium is transported from the detected position until it is exposed by the exposure length. A drive time setting means for setting the drive time;
The drive control for driving the transport member during the drive time set by the drive time setting means when it is determined that the medium remains in the transport path and the transport path is opened. Means,
The medium conveying apparatus according to claim 1, further comprising: A passage for detecting whether or not the medium has passed a preset reference position on the upstream side in the transport direction of the transport path as compared to the positions where the first guide portion and the second guide portion are disposed. Detecting means of
The medium that has passed the reference position is the time from when it is detected that the medium has passed the reference position by the passage detection means until the medium is detected by the residual detection means to remain in the transport path. A transport time measuring means for measuring the transport time of
The position detecting means for detecting the position of the remaining medium in the transport path based on the transport time;
The medium conveying apparatus according to claim 2, further comprising: The exposure length storage means for storing a predetermined reference exposure length for an exposure length that is a length for exposing a part of the remaining medium from an open portion of the transport path;
When a part of the remaining medium is exposed from the opened part of the transport path, a holding length that is a length of a part of the exposed medium held in the transport path is set in advance. A retention length storage means for storing the reference retention length;
A length storage means for storing the length of the transported medium in the transport direction;
A length discriminating means for discriminating whether or not the difference between the length in the conveyance direction of the medium and the reference holding length is longer than the reference exposure length;
If the difference is determined to be longer than the reference exposure length by the length determination means, an exposure length setting means for setting the difference as the exposure length;
Based on the exposure length set by the exposure length setting means and the position detected by the position detection means, the remaining medium is transported from the detected position to determine the exposure length. The drive time setting means for setting the drive time of the conveying member until it is only exposed;
The medium conveying apparatus according to claim 2, wherein the medium conveying apparatus is provided. A type of storage means for storing the type of medium to be conveyed;
The exposure length storage means for storing the exposure length set in advance according to the type of medium;
An exposure length setting means for setting the exposure length based on the type of medium remaining in the conveyance path and the exposure length stored in the exposure length storage means;
Based on the exposure length set by the exposure length setting means and the position detected by the position detection means, the remaining medium is transported from the detected position to determine the exposure length. The drive time setting means for setting the drive time of the conveying member until it is only exposed;
The medium conveying apparatus according to claim 2, wherein the medium conveying apparatus is provided. A storage section for storing the medium;
An extraction member for taking out the medium stored in the storage unit;
The medium carrying device according to any one of claims 1 to 5, wherein the medium taken out by the take-out member is carried,
An image recording unit for recording an image on a medium conveyed by the medium conveying device;
An image forming apparatus comprising:

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