JP7192384B2 - image forming device - Google Patents

Description

The present invention relates to an image forming apparatus that forms an image on a conveyed sheet.

2. Description of the Related Art In an image forming apparatus such as a printer, a sheet being conveyed may get stuck somewhere on the conveying path or become skewed and jam (jam). When such a jam occurrence is detected, the sheet conveying operation is interrupted. The jammed sheet on the conveying path is removed manually by the user by opening the jam clearing cover that opens the conveying path to the outside of the apparatus.

FIG. 14 is a schematic front view showing a configuration example of an image forming apparatus having a jam handling cover. As shown in the figure, the image forming apparatus 900 includes image forming units 901Y and 901M for forming toner images of different colors, here Y (yellow), M (magenta), C (cyan), and K (black). , 901C and 901K are arranged side by side along the intermediate transfer belt 902, which is a so-called tandem type color printer.

Y to K toner images formed by the image forming units 901Y to 901K are transferred onto the intermediate transfer belt 902 in multiple layers. In parallel with this toner image forming operation, the sheet S fed out from the paper feed cassette 903 passes through a pair of timing rollers 920 to a transfer position between the intermediate transfer belt 902 and the transfer roller 907 pressed against it. 908 along the transport path 909 . The toner image superimposed on the intermediate transfer belt 902 is transferred onto the sheet S when the sheet S passes through the transfer position 908 . After passing through the transfer position 908 , the sheet S is fixed by the fixing unit 904 and discharged to the tray 906 by the discharge roller 905 .

As a jam clearing cover for such an image forming apparatus, Japanese Patent Application Laid-Open No. 2002-200003 discloses a so-called vertical opening type cover 930 . Specifically, the cover 930 is rotatably supported around a support shaft 932 extending in the horizontal direction, and when the cover 930 is in the closed position indicated by the solid line, the user can hold the upper end 931 by hand and move the arrow A. By tilting it in the direction, it rotates to the open position indicated by the dashed line around the support shaft 932 at the lower end. As a result, the transport path 909 is opened.

The intermediate transfer belt 902 and the first timing roller 921 of the pair of timing rollers 920 are rotatably supported by the body frame 910 of the image forming apparatus indicated by the dashed line. , is rotatably supported by a support unit 940 connected to the cover 930 .

When the user opens the cover 930, the support unit 940 connected to the cover 930 is separated from the main body frame 910. Therefore, the image forming apparatus 900 can be viewed obliquely from above as indicated by the dashed arrow B from outside the image forming apparatus 900. By inserting a hand downward into the space between the main body frame 910 and the support unit 940, the sheet S jammed on the conveying path 909 can be taken out.

JP 2015-227907 A

In the vertical opening method described above, the space between the body frame 910 and the support unit 940 in the open state of the cover 930 is much narrower on the lower side where the support shaft 932 exists than on the upper side. Therefore, it is difficult for the user to remove the sheet S jammed near the first timing roller 921 located below the intermediate transfer belt 902 .

Therefore, instead of the vertical opening method, as shown in the front perspective view of FIG. 15(a), a horizontal opening method in which the cover 930 is opened and closed around a support shaft 932 along the vertical direction is conceivable.

In the horizontal opening method, when the cover 930 is in the open state shown in the figure, a space 991 between the body frame 910 and the support unit 940 is opened to the front side of the apparatus. Therefore, the user can easily reach the intermediate transfer belt 902 and the vicinity of the first timing roller 921 located below the intermediate transfer belt 902 from the front side of the apparatus, and can easily remove the jammed sheet S.

In the configuration in which the support unit 940 is connected to the cover 930 in this way, it is necessary to position the support unit 940 with respect to the body frame 910 when the cover 930 is closed. This positioning can be facilitated by, for example, adopting the following configuration.

That is, two pins 941 and 942 are provided on the front side of the support unit 940 and are spaced apart vertically. set up. A set of a pin and a receiving portion similar to this, that is, two positioning portions are also provided on the rear side of the device.

Then, as shown in the schematic front view of FIG. 15B, the pin 941 of the support unit 940 is fitted into the concave portion 953 of the receiving portion 951 of the body frame 910 as the cover 930 is closed. The same applies to the other three sets of positioning parts.

In the case of adopting this fitting configuration, when the user opens the cover 930, it is necessary to release the fitting between the pins of the four positioning portions and the concave portions. This engagement can be released by pulling out the pin 941 from the concave portion 953 , but the pin 941 is likely to be caught on the upper end portion 954 of the concave portion 953 . Therefore, the user is required to open the cover 930 with a force stronger than the resistance caused by the catching.

The positioning accuracy is higher when the number N of positioning portions is larger than when the number N is small. A force F1 (=F×n) multiplied by n must be applied to the cover 930, and the required large force F1 lowers the operability. If the upper end portion 954 of the concave portion 951 is lowered, for example, to the position of the dashed line 955, the pin 941 can be easily moved in the left-right direction, and the positioning accuracy is lowered accordingly.

Although the configuration example in which the transfer roller 907 and the second timing roller 922 are arranged in the support unit 940 has been described above, the configuration is not limited to this. A problem similar to that described above may occur in general in a configuration in which a plurality of conveying members such as rollers and guides used for conveying the sheet S are separately arranged on the main body frame side and the support unit side.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is capable of improving operability when a user opens a side-opening type cover while positioning a support unit on a body frame in at least two positions. An object of the present invention is to provide an image forming apparatus.

In order to achieve the above object, an image forming apparatus according to the present invention is an image forming apparatus for forming an image on a conveyed sheet, and is constructed by facing a first conveying member and a second conveying member. A sheet conveying path, a main body frame of an image forming apparatus on which the first conveying member is installed, an exterior body of the image forming apparatus having an opening corresponding to an installation position of the first conveying member, and the edge of the opening. a cover rotatably provided on a support shaft along the sheet conveying direction and capable of freely opening and closing the opening; and the second conveying member facing the first conveying member when the cover is in the closed state. and a support unit for supporting the conveying member positioned on the cover side, wherein the supporting unit is fitted with first and second positioning members provided along the sheet conveying direction on the body frame side. first and second engaging projections having first and second positioned members that can be engaged and disengaged and loosely fitted in first and second through holes provided in the cover, or The cover has first and second through holes into which the first and second engaging projections are loosely fitted. When the cover is closed, the first and second positioned members The first and second fitting states are achieved by fitting the first and second positioning members, and the first and second engaging protrusions are engaged with the first and second through holes. while maintaining the second conveying member in a state facing the first conveying member in cooperation with a state, when the cover is rotated in the opening direction from the closed state, a pulling force due to the rotation of the cover. As a result, the first engaging projection moves in the first through hole and comes into contact with the hole edge of the first through hole, and the support unit is pulled by the cover through this contact state. When the first fitting is released by the pulling force and the cover continues to rotate, the second engaging projection moves in the second through hole and moves to the edge of the second through hole. Through this abutting state, the support unit is pulled by the cover, and the pulling force releases the second fitting, so that the first and second positioning members and the first , the positional relationship and the size of the first and second through holes until the second positioned member is disengaged, and the first and second positioning members are arranged in the body frame to: The body frame is arranged on the side farther from the support shaft across the sheet passing area in the width direction of the sheet, and the body frame is arranged on the side closer to the support shaft across the sheet passing area in the width direction of the sheet. positioning member, and the support unit a third positioned member capable of being engaged with and disengaged from the third positioning member; or a third through hole for loosely fitting the third engaging projection provided on the cover, and the cover is closed At this time, the third positioned member is in the third fitted state in which it is fitted into the third positioning member, and the engagement state between the third engaging projection and the third through-hole also cooperates. the second conveying member is kept facing the first conveying member, and the third engagement protrusion is engaged with the third through hole until the second engagement is released. When the cover continues to rotate after the second fitting is released, the third engaging projection moves. through this contact state, the side of the support unit closer to the support shaft is pulled by the cover to release the third fitting. It is characterized in that the positional relationship and the size of the third through hole until the engagement between the third positioning member and the third positioned member is released are determined .

Here, the body frame is provided on the side closer to the support shaft across the sheet passing area in the width direction of the sheet, and on the upstream side or the downstream side in the sheet conveying direction with respect to the third positioning member. The support unit further has a fourth positioned member that can be engaged with and released from the fourth positioning member, and when the cover is in the closed state. , the fourth positioned member is also fitted to the fourth positioning member, and when the third fitting is released, the position between the fourth positioned member and the fourth positioning member The positional relationship and the size of the third through-hole may be determined so that the engagement between the fourth positioning member and the fourth positioned member is released so that the engagement is also released.

An image forming apparatus according to another aspect of the present invention is an image forming apparatus that forms an image on a conveyed sheet, and includes a sheet conveying path configured by facing a first conveying member and a second conveying member. a body frame of the image forming apparatus on which the first conveying member is installed; an exterior body of the image forming apparatus in which a portion corresponding to the installation location of the first conveying member is opened; a cover that is rotatably provided on a support shaft along the conveying direction and that can open and close the opening; and the second conveying member that faces the first conveying member when the cover is in the closed state. is positioned on the cover side, and the support unit is fitted with first and second positioning members provided along the sheet conveying direction on the body frame side, and First and second engaging projections having releasable first and second positioned members and loosely fitted in first and second through holes provided in the cover, or on the cover It has first and second through holes into which the provided first and second engaging projections are loosely fitted. The first and second mating states of fitting to the second positioning member are established, and the first and second mating protrusions are engaged with the first and second through holes in cooperation with the mating states. function to maintain the second conveying member facing the first conveying member, and when the cover is rotated in the opening direction from the closed state, the tensile force due to the rotation of the cover causes the The first engaging projection moves in the first through hole and abuts against the hole edge of the first through hole, and through this abutting state, the support unit is pulled by the cover. When the first fitting is released by force and the cover continues to rotate, the second engaging projection moves in the second through hole and contacts the edge of the second through hole. The support unit is pulled by the cover through this abutting state, and the pulling force releases the second fitting so that the first and second positioning members and the first and second positional relationship leading to disengagement of the positioned member and sizes of the first and second through holes are determined, and the first and second engaging projections are provided on the support unit, The first and second through holes are provided in the cover, the support shaft is a vertical axis, and the hole edge of the first through hole is a first vertical wall. and the hole edge portion of the second through hole advances in the direction opposite to the opening direction of the cover. a second vertical wall portion that continues to the inclined wall portion of the second through hole that inclines obliquely upward along with the second vertical wall portion, the second vertical wall portion being closer to the cover than the first vertical wall portion; It is characterized by being positioned upstream in the opening direction of the.

Further, the hole edge of the first through hole on the opposite side in the rotational direction of the cover to the hole edge of the first through hole that abuts on the first engaging projection as the cover is opened. is the first hole edge, and the hole edge of the second through hole on the side opposite to the hole edge of the second through hole that abuts on the second engaging projection in the rotational direction of the cover. A second hole edge portion, the hole edge portion of the third through hole on the opposite side in the rotation direction of the cover from the hole edge portion of the third through hole that abuts on the third engaging projection, is the third hole edge portion. When the cover is turned from the open state to the closing direction opposite to the opening direction and is returned to the closed state, the third engaging projection and the third hole edge are first brought into contact with each other. The support unit is pushed by the cover due to the contact of the cover, and the third positioned member is fitted into the third positioning member by the pressing force, and after this fitting, the rotation in the closing direction continues. The support unit is pushed against the cover by the contact between the second engaging projection and the second hole edge, and the pushing force causes the second positioned member to fit into the second positioning member. After this fitting, when the rotation in the closing direction continues, the support unit is pushed by the cover due to the contact between the first engaging projection and the first hole edge, and the pressing force The positional relationship in the closing direction of the first, second, and third hole edge portions may be determined such that the first positioned member fits into the first positioning member.

An image forming apparatus according to still another aspect of the present invention is an image forming apparatus that forms an image on a conveyed sheet, the sheet conveying apparatus configured such that a first conveying member and a second conveying member face each other. a path, a body frame of the image forming apparatus on which the first conveying member is installed, an exterior body of the image forming apparatus having an opening corresponding to a location where the first conveying member is installed, and the edge of the opening, a cover rotatably provided on a support shaft along a sheet conveying direction and capable of freely opening and closing the opening; and the second conveying member facing the first conveying member when the cover is in the closed state. a support unit for supporting the member positioned on the cover side, wherein the support unit is fitted to and fitted with first and second positioning members provided along the sheet conveying direction on the body frame side. First and second engaging projections having first and second releasable members to be positioned and loosely fitted in first and second through holes provided in the cover, or the cover has first and second through-holes into which the first and second engaging projections provided on the upper part are loosely fitted, and when the cover is in the closed state, the first and second positioned members , a first fitting state and a second fitting state in which the second positioning member is fitted, and an engagement state between the first and second engaging protrusions and the first and second through holes. While cooperating to maintain the second conveying member facing the first conveying member, when the cover is rotated in the opening direction from the closed state, a tensile force due to the rotation of the cover causes: The first engaging projection moves in the first through hole and comes into contact with the hole edge of the first through hole, and the support unit is pulled by the cover through this contact state. When the first fitting is released by a pulling force and the cover continues to rotate, the second engaging projection moves in the second through hole and engages the edge of the second through hole. The support unit is pulled by the cover through this contact state, and the pulling force releases the second fitting, so that the first and second positioning members and the first and second The positional relationship and the sizes of the first and second through-holes are determined until the engagement of the two members to be positioned is released, and the first position of the first member to be positioned in the axial direction of the support shaft is determined. and the second position of the second member to be positioned, and the first engaging projection on one side near the first member to be positioned across a virtual plane perpendicular to the axial direction. is located and far from the first positioned member It is characterized in that the second engaging projection is positioned on one side.

Here, the first positioned member is located on the upstream side of the second positioned member in the sheet conveying direction, and the first engaging projection is positioned further toward the sheet conveying direction than the second engaging projection. It may be located on the upstream side in the direction.

An image forming apparatus according to still another aspect of the present invention is an image forming apparatus that forms an image on a conveyed sheet, the sheet conveying apparatus configured such that a first conveying member and a second conveying member face each other. a path, a body frame of the image forming apparatus on which the first conveying member is installed, an exterior body of the image forming apparatus having an opening corresponding to a location where the first conveying member is installed, and the edge of the opening, a cover rotatably provided on a support shaft along a sheet conveying direction and capable of freely opening and closing the opening; and the second conveying member facing the first conveying member when the cover is in the closed state. a support unit for supporting the member positioned on the cover side, wherein the support unit is fitted to and fitted with first and second positioning members provided along the sheet conveying direction on the body frame side. First and second engaging projections having first and second releasable members to be positioned and loosely fitted in first and second through holes provided in the cover, or the cover has first and second through-holes into which the first and second engaging projections provided on the upper part are loosely fitted, and when the cover is in the closed state, the first and second positioned members , a first fitting state and a second fitting state in which the second positioning member is fitted, and an engagement state between the first and second engaging protrusions and the first and second through holes. While cooperating to maintain the second conveying member facing the first conveying member, when the cover is rotated in the opening direction from the closed state, a tensile force due to the rotation of the cover causes: The first engaging projection moves in the first through hole and comes into contact with the hole edge of the first through hole, and the support unit is pulled by the cover through this contact state. When the first fitting is released by a pulling force and the cover continues to rotate, the second engaging projection moves in the second through hole and engages the edge of the second through hole. The support unit is pulled by the cover through this contact state, and the pulling force releases the second fitting, so that the first and second positioning members and the first and second The positional relationship and the sizes of the first and second through-holes are determined so that the two members to be positioned are disengaged, the first member to be positioned is a first positioning pin, and the The first positioning member has a first concave portion into which the first positioning pin is fitted, the first concave portion is open on the downstream side in the opening direction of the cover, and the body frame includes: When the cover is opened, the first recess is formed. a lever member movable between a first position on the movement path of the first positioning pin moving in the opening direction of the cover from the opening of the part and a second position retreating from the movement path; a biasing member that biases the cover in a direction from the second position toward the first position, wherein the lever member is positioned at the first position when the cover is in the closed state, and the first The first positioning pin fitted in the recess has an inclined surface that applies a pressing force to the bottom of the recess, and when the cover starts to open, it begins to move in the opening direction. The inclined surface is pushed by the first positioning pin and retreats from the first position to the second position against the biasing force of the biasing member .

Here, the positions of the first positioning pin and the first engaging projection in the first fitting state in which the first recess is fitted in the axial direction of the support shaft may be the same position. .

Further, the second member to be positioned is a second positioning pin, the second positioning member has a second recess into which the second positioning pin is fitted, The recess may open in a direction inclined by a predetermined angle downstream in the opening direction of the cover with respect to the axial direction of the support shaft, and the bottom surface may be closed.

Further, the first and second conveying members may be first and second rollers that nip and convey the sheet.

As a result, the force applied to the cover when the user opens the cover can be reduced as compared with the configuration in which the two positions of the first and second positioning members on the body frame are released at the same time. Operability when opening can be improved.

1 is a schematic front view for explaining the configuration of a printer; FIG. FIG. 4 is a schematic perspective view of a closed cover viewed from the front side of the apparatus; It is a schematic perspective view when the cover in an open state is seen from the front side of the device. FIG. 4 is a front exploded perspective view of a support unit and a cover; FIG. 5 is a rear perspective view when the support unit is viewed from the direction of arrow C in FIG. 4; 4(a) to 4(e) are enlarged views for explaining the configuration of a positioning portion on the front side and the lower side of the apparatus provided on the body frame. FIG. FIG. 4 is an enlarged view for explaining the configuration of a positioning portion on the front side and upper side of the apparatus provided on the body frame; FIG. 4 is an enlarged view for explaining the configuration of a positioning portion on the back side and upper side of the device provided on the body frame; FIG. 4 is an enlarged view for explaining the configuration of a positioning portion on the back side and lower side of the device provided on the body frame; (a) to (d) show step by step how two positioning pins positioned on the front side of the device of the support unit are released from the concave portions of the two positioning members of the body frame in this order as the cover is opened. 3 is a schematic diagram shown in FIG. (a) to (d) show step by step how the two positioning pins positioned on the back side of the device of the support unit are released substantially simultaneously from the concave portions of the two positioning members of the body frame as the cover is opened. 3 is a schematic diagram shown in FIG. In (a) to (c), as the closing operation of the cover in the open state progresses, the two positioning pins positioned on the back side of the device of the support unit are fitted into the concave portions of the two positioning members of the body frame substantially simultaneously. It is a schematic diagram showing step by step how it is done. (a) to (c) show how the two positioning pins positioned on the front side of the device of the support unit are fitted into the concave portions of the two positioning members of the body frame while being displaced as the closing operation of the cover progresses. It is a schematic diagram showing step by step. 1 is a schematic front view showing a configuration example of an image forming apparatus having a cover for jam handling; FIG. (a) is a perspective view showing a configuration example of a side-opening type cover, and (b) is a schematic diagram for explaining how positioning is performed by fitting a pin into a recess.

Hereinafter, an embodiment of an image forming apparatus according to the present invention will be described using a tandem color printer (hereinafter abbreviated as "printer") as an example.

FIG. 1 is a schematic front view for explaining the configuration of the printer 1. FIG. In the figure, the X-axis direction corresponds to the horizontal direction when the printer 1 is viewed from the front side, and the Y-axis direction corresponds to the vertical direction. A direction orthogonal to both the X-axis and the Y-axis is sometimes referred to as the Z-axis direction (depth direction).

As shown in the figure, the printer 1 is a tandem-type image forming apparatus including image forming units 10Y, 10M, 10C, and 10K, an intermediate transfer unit 20, a paper feeding unit 30, a fixing unit 40, and the like. ), various jobs including a print job for printing a color image on a recording sheet S based on image data sent from an external terminal device (not shown) can be executed.

The image forming unit 10Y includes a photosensitive drum 11, a charging unit 12, an exposure unit 13, a developing unit 14, a primary transfer roller 15, a cleaner 16 for cleaning the photosensitive drum 11, and the like. A Y-color toner image is formed on the photosensitive drum 11 rotated in the direction of the arrow. The other image forming units 10M, 10C, and 10K have the same configuration as the image forming unit 10Y. image on top. Reference numerals are omitted for the image forming units 10M to 10K.

The intermediate transfer section 20 includes an endless intermediate transfer belt 21, a drive roller 22 and a driven roller 23 that stretch the intermediate transfer belt 21, and makes the intermediate transfer belt 21 circulate in the direction of the arrow in FIG.

The paper feed unit 30 includes a paper feed cassette 31 that stores sheets S for recording, a feed roller 32 that feeds out the sheets S in the paper feed cassette 31 one by one, and the fed sheets S along a transport path 39 . A pair of conveying rollers 33 for conveying, a pair of timing rollers 34 for determining the timing of sending the conveyed sheet S to the secondary transfer position 35a, a secondary transfer roller 35, and the like are provided. The timing roller pair 34 consists of a first timing roller 301 as a first conveying member and a second timing roller 302 as a second conveying member. Each roller such as the first timing roller 301, the second timing roller 302, and the secondary transfer roller 35 is arranged so that its axial direction is parallel to the Z-axis direction.

The fixing unit 40 includes a cylindrical fixing roller 41 and a pressure roller 42 that are pressed against each other, a heater 43 for heating the fixing roller 41, and the like.

With such a configuration, when a print job is executed, the light beam L is emitted from the light source of the exposure unit 13 for each of the image forming units 10Y to 10K based on image data sent from an external terminal device via the network. The light is emitted to expose and scan the photosensitive drum 11 .

Prior to this exposure scanning, the photosensitive drums 11 of the image forming units 10Y to 10K are uniformly charged by the charging units 12, and the light beams L from the exposure unit 13 are applied to the photosensitive drums 11 by the exposure scanning. An electrostatic latent image is formed on the The formed electrostatic latent image is developed with the developer contained in the corresponding developing section 14 to form a toner image on the photosensitive drum 11 .

The toner image on the photoreceptor drum 11 is primarily transferred onto the intermediate transfer belt 21 by the electrostatic force acting between the photoreceptor drum 11 and the primary transfer roller 15 in each of the image forming units 10Y to 10K. At this time, the image forming operation of each color is executed with a timing shift so that the toner images are superimposed on the same position on the intermediate transfer belt 21 and transferred in multiple layers. As the intermediate transfer belt 21 circulates, the toner images of each color multiple-transferred onto the intermediate transfer belt 21 move to a secondary transfer position 35a where the secondary transfer roller 35 and the intermediate transfer belt 21 are in contact with each other.

The sheet S is fed from the sheet feeding unit 30 via the pair of timing rollers 34 in accordance with the above image forming timing, and the sheet S is transferred to the circulating intermediate transfer belt 21 and the secondary transfer belt 21 . It is sandwiched between rollers 35 and conveyed. At that time, due to the action of the electrostatic force of the secondary transfer roller 35, the toner images of each color on the intermediate transfer belt 21 are secondary-transferred collectively onto the sheet S at the secondary transfer position 35a.

After passing through the secondary transfer position 35a, the sheet S is conveyed to the fixing section 40. When passing through the fixing section 40, the toner image on the sheet S is heated and pressurized to be fixed on the sheet S, and then discharged. It is discharged via the roller pair 36 and stored in the storage tray 37 .

The imaging units 10Y to 10K, the intermediate transfer unit 20, and the first timing roller 301 are supported by a body frame 2 (broken line) that constitutes the apparatus body. The second timing roller 302 and the secondary transfer roller 35 are rotatably supported by a support unit 50 separate from the body frame 2 .

The support unit 50 is positioned on the body frame 2 by fitting four positioned members corresponding to four positioning members provided on the body frame 2 as will be described later. As a result of this positioning, the second timing roller 302 presses the first timing roller 301, and the secondary transfer roller 35 presses the intermediate transfer belt 21 at the secondary transfer position 35a.

On the opposite side of the body frame 2 with the support unit 50 interposed therebetween, a lateral opening type jam handling opening/closing cover 60 (hereinafter simply referred to as "cover 60") is provided. As will be described later, the support unit 50 is connected to the cover 60 at three points and supported so as to be movable within a certain range with respect to the cover 60 .

2 is a schematic perspective view of the cover 60 in a closed state as viewed from the front side of the device, and FIG. 3 is a schematic perspective view of the cover 60 in an open state as viewed from the front side of the device. In addition, in FIGS. 2 and 3, illustration of parts that are not related to the explanation is omitted. This partial omission is the same for FIG. 4 and subsequent figures.

As shown in FIGS. 2 and 3, the cover 60 closes the opening 3a in the center of the exterior cover 3 (exterior body) that constitutes the right side of the printer 1, and is provided on the rear side of the printer. By rotating in the direction of arrow G around the support shaft 6a, the closed state is changed to the open state. The opening 3 a is an opening for exposing to the outside of the printer 1 portions corresponding to the installation locations of the first timing roller 301 and the drive roller 22 installed on the body frame 2 . The support shaft 6a is rotatably supported by bearings (not shown) provided in the body frame 2 or other members in the printer 1. As shown in FIG.

The cover 60 is provided with an opening/closing lever 69 having hooks 68a and 68b (FIGS. 3 and 4). When the opening/closing cover 60 is closed, hooks 68a and 68b are hooked on two stoppers 2d (only one is shown in FIG. 3, the other is omitted) provided on the body frame 2, thereby opening the cover 60. Rotation in the direction is prohibited (locked) and the closed state is maintained. When the cover 60 is closed, the support unit 50 connected to the cover 60 is positioned on the body frame 2 .

Positioning is performed by four positioning members 101, 102, 103 and 104 provided on the body frame 2 and four positioned members 71, 72, 73 and 74 provided on the support unit 50 as shown in FIG. , 73, and 74 are shown in FIG. 5) is performed by fitting, specifically by uneven fitting in which the convex portion is fitted into the concave portion. The positioning members 101 to 104 are arranged outside the sheet passing area Sa of the sheet S in the sheet width direction (the direction along the leading edge of the sheet orthogonal to the sheet conveying direction: corresponding to the Z-axis direction).

Specifically, positioning members 101 and 102 are arranged on the front side of the apparatus, which is one side in the sheet width direction, while positioning members 103 and 104 are arranged on the rear side of the apparatus, which is the other side, with the sheet S to be conveyed sandwiched therebetween. ing.

When the user opens the open/close lever 69 while the cover 60 is closed, the hooks 68a and 68b are released from the stopper 2d. As a result, the lock in the opening direction of the cover 60 is released. The user can open the cover 60 by pulling out the cover 60 in the direction of the arrow G while gripping the open/close lever 69 .

Since the support unit 50 is connected to the cover 60, a tensile force due to the rotation of the cover 60 is transmitted to the support unit 50 as the cover 60 is opened. 74 and the positioning members 101 to 104 of the body frame 2 are released from the concave-convex engagement, and the support unit 50 is separated from the body frame 2 .

This engagement is released by pulling out the projections that are fitted in the recesses. It is configured to fit. Therefore, to release the engagement, it is necessary to apply a certain amount of force required to separate the protrusion from the recess, and the engagement cannot be released with a force smaller than the certain amount of force.

In the present embodiment, the connection mechanism between the support unit 50 and the cover 60 is devised so that the user can perform the opening operation without applying a large force to release the engagement. ing. The connecting mechanism and the positioning mechanism of the support unit 50 to the apparatus body frame 2 will be described below.

4 is a front exploded perspective view of the support unit 50 and the cover 60, and FIG. 5 is a rear perspective view of the support unit 50 viewed from the direction of arrow C in FIG.

As shown in FIGS. 4 and 5, the support unit 50 has a support portion 52 that rotatably supports the second timing roller 302 and a support portion 53 that rotatably supports the secondary transfer roller 35 . The support unit 50 also includes a first guide 54 that guides the sheet S to the second timing roller 302 below the support portion 52 and a secondary transfer roller 35 that is above the secondary transfer roller 35 . It has a second guide 55 that guides the sheet S after passing through 35 to the fixing section 40 .

Further, as shown in FIG. 4, on the side surface 51a of the support unit 50 on the front side of the apparatus, convex positioning members 71 and 72 are provided at the ends on the side far from the cover 60, that is, on the side close to the body frame 2, in the vertical direction. , and convex engagement protrusions 81 and 82 are provided at the end portion on the side closer to the cover 60 at intervals in the vertical direction.

Further, as shown in FIG. 5, on the side surface 51b of the support unit 50 on the back side of the device, convex positioned members 73 and 74 are provided at the end portion on the side closer to the main body frame 2 at intervals in the vertical direction. , a convex engagement projection 83 is provided at the end portion on the side closer to the cover 60 . Hereinafter, the member to be positioned will be called a positioning pin, and the engaging member will be called an engaging pin.

As shown in FIG. 4, on the inner surface 61 of the cover 60 on the side facing the support unit 50, a front side support member 90a for supporting the engagement pins 81 and 82 provided on the support unit 50 and an engagement pin 83 are supported. A rear side support member 90b is erected.

The front-side support member 90a is a vertically elongated thin plate, stands upright on the inner surface 61 of the cover 60 along the XY plane, and penetrates in the Z-axis direction (corresponding to the seat width direction). Two through-holes 91 and 92 are provided with a space therebetween in the vertical direction. Of the engaging pins 81 and 82 on the front side of the device, the lower engaging pin 81 is loosely fitted in the lower through hole 91 , and the upper engaging pin 82 is loosely fitted in the upper through hole 92 . be fitted.

The back side support member 90b is a thin plate, and stands on the inner surface 61 of the opening/closing cover 60 in a position along the XY plane at a position closer to the back side of the device than the front side support member 90a. A through hole 93 is drilled through in the direction. An engagement pin 83 on the rear side of the apparatus is loosely fitted in the through hole 93 . That is, the through hole is a so-called blank hole with respect to the engaging pin.

The support unit 50 is arranged in the Y-axis direction (vertical direction: corresponding to the axial direction of the support shaft 6a) and the X-axis direction with respect to the cover 60 by loosely fitting the engaging pins 81 to 83 in the through holes 91 to 93. It is movably supported within a certain range (far and near directions with respect to the cover 60). The engaging pins 81 to 83 and the through holes 91 to 93 constitute a connecting mechanism for supporting and connecting the support unit 50 to the cover 60 so as to be movable in the vertical direction and the distance direction.

When the user closes the cover 60, the support unit 50 approaches the body frame 2, and the positioning pins 71-74 provided on the support unit 50 are fitted into the recesses of the positioning members 101-104 of the body frame 2. Then, the positioning of the support unit 50 to the apparatus body frame 2 is completed. Thereafter, when the hooks 68a and 68b of the cover 60 are hooked on the stoppers 2d of the body frame 2 and locked, the cover 60 is closed.

Next, the positioning members 101 to 104 on the body frame 2 side will be described.

FIG. 6A is an enlarged perspective view of the positioning portion 101 on the front side and lower side of the device.

As shown in the figure, the positioning portion 101 has a receiving portion 110 , a lever 112 and a compression coil spring 113 . Here, the direction parallel to the X-axis and opposite to the direction of the arrow X (the direction toward the support unit 50) is referred to as the X' direction.

The receiving portion 110 has a concave portion 111 that opens in the X' direction.

As shown in the enlarged perspective view of FIG. 6B, the lever 112 has an arm 117 extending from a bearing portion 116 in the X' direction. A through-hole 161 is formed through the bearing portion 116 in the Z-axis direction. As a result, the lever 112 is rotatable about the fixed shaft 2e in both the arrow E direction and the opposite direction.

The tip of the arm 117 has a protrusion 109 that protrudes upward. Protruding portion 109 has a first inclined surface 191 on the side closer to bearing portion 116 across top portion 190 and a second inclined surface 192 on the side farther from bearing portion 116 . The first inclined surface 191 is an inclined surface that descends from the top portion 190 as it approaches the bearing portion 116 , and the second inclined surface 192 descends from the top portion 190 as it moves away from the bearing portion 116 . It is the surface.

The compression coil spring 113 is arranged below the arm 117 and urges the arm 117 upward with its elastic force. Arm 117 is urged upward by compression coil spring 113, and projection 193 provided near bearing 116 hits a stopper (not shown) provided on receiving portion 110, thereby moving arm 117 upward above the stopper. movement is restricted. FIG. 6(a) shows how the arm 117 is positioned at the top due to the restriction of the stopper. The position of the lever 112 shown in the figure is called a home position.

6(c) to 6(e) are schematic front views showing step by step how the positioning pin 71 on the support unit 50 side is positioned in the positioning portion 101 by closing the cover 60. FIG.

FIG. 6(c) shows how the positioning pin 71 moving in the direction of the arrow X moves toward the second inclined surface 192 of the lever 112 positioned at the home position.

As shown in FIG. 6(d), when the positioning pin 71 hits the second inclined surface 192 of the lever 112, a downward force component corresponding to the inclination angle of the inclined surface 192 acts on the lever 112 from the positioning pin 71, causing the lever to move downward. The arm 117 of 112 rotates around the fixed shaft 2e in the direction of arrow E against the biasing force of the compression coil spring 113, and the top portion 190 moves downward.

When the movement of the positioning pin 71 in the direction of the arrow X further progresses and the positioning pin 71 passes over the top portion 190 of the arm 117, the recess 111 moves downward from the opening 114 of the recess 111 while descending on the first inclined surface 191 of the arm 117. In parallel with this, the arm 117 rotates around the fixed shaft 2e in the direction opposite to the arrow E direction due to the biasing force of the compression coil spring 113, and the top portion 190 begins to move upward.

Thereafter, as shown in FIG. 6E, when the positioning pin 71 that has entered the recess 111 hits the bottom surface 151 of the recess 111, the movement of the positioning pin 71 is restricted. At this regulated position, the positioning pin 71 is fitted into the recess 111 while being surrounded by the inner bottom surface 151 , lower surface 152 and upper surface 153 of the recess 111 and the first inclined surface 191 of the lever 112 from above, below, left and right. The engaging pin 71 is vertically positioned by the lower surface 152 and the upper surface 153 of the recess 111, and is pressed against the inner bottom surface 151 of the recess 111 by the first inclined surface 191 of the lever 112 on which the biasing force of the compression coil spring 119 is acting. Positioning is performed in the left-right direction.

FIG. 7 is an enlarged perspective view of the positioning portion 102 on the front side and upper side of the device.

As shown in the figure, the positioning portion 102 has a concave portion 121 that opens obliquely upward and is inclined by a predetermined angle (for example, about 10°) in the X′ direction with respect to the vertical direction (Y-axis direction).

When the positioning pin 72 on the side of the support unit 50 that moves in the direction of arrow X by closing the cover 60 goes over the upper surface 126 of the recess 121, it falls into the recess 121 from the opening 122 of the recess 121 by the weight of the support unit 50. It hits the bottom surface 123 of the recess 121 . As a result, the positioning pin 72 is fitted into the recess 121 while being surrounded by the bottom surface 123 and the side surfaces 124 and 125 of the recess 121, and is positioned vertically and horizontally.

FIG. 8 is an enlarged perspective view of the positioning portion 103 on the back side and upper side of the device.

As shown in the figure, the positioning portion 103 includes a concave portion 131 that opens obliquely upward in the same manner as the positioning portion 102, and a concave portion 131 that extends in the direction of the arrow X' and extends downward in the direction of the arrow X'. It has an inclined surface 137 which is inclined.

When the cover 60 is closed, the positioning pin 73 on the side of the support unit 50 moving in the direction of the arrow X is guided obliquely upward along the inclined surface 137. The support unit 50 falls into the recess 131 from the opening 132 of the support unit 50 and hits the bottom surface 133 of the recess 131 . As a result, the positioning pin 73 is fitted into the recess 131 while being surrounded by the bottom surface 133 and the side surfaces 134 and 135 of the recess 131, and is positioned vertically and horizontally.

FIG. 9 is an enlarged perspective view of the positioning portion 104 on the rear side and lower side of the apparatus.

As shown in the figure, the positioning portion 104 includes a concave portion 141 that opens obliquely upward in the same manner as the positioning portion 102, and a concave portion 141 that extends in the direction of the arrow X' from the concave portion 141 and extends downward in the direction of the arrow X'. It has an inclined surface 147 that is inclined.

By closing the cover 60, the positioning pin 74 on the side of the support unit 50 moving in the direction of the arrow X is guided obliquely upward along the inclined surface 147. The support unit 50 falls into the recess 141 from the opening 142 of the support unit 50 by its own weight, and hits the bottom surface 143 of the recess 141 . As a result, the positioning pin 74 is fitted into the recess 141 while being surrounded by the bottom surface 143 and the side surfaces 144 and 145 of the recess 141, and is positioned vertically and horizontally.

By fitting the positioning pins 71 to 74 on the side of the support unit 50 into the concave portions of the positioning portions 101 to 104 on the side of the body frame 2 as described above, the support unit 50 is positioned with respect to the device body frame 2 at four points. be.

With the support unit 50 positioned on the body frame 2 at four positions as described above, when the user performs an operation to open the cover 60, in the present embodiment, first, among the four positions, the front side and the lower side of the apparatus are opened. The fitting of the positioning pin 71 with the concave portion 111 of the positioning portion 101 is released first. After the release, the positioning pin 72 is released from the recess 121 of the positioning portion 102 on the upper side. , 74 are disengaged.

10(a) to 10(d) show that as the cover 60 is opened, the positioning pins 71 and 72 positioned on the front side of the support unit 50 move toward the concave portions 111 and 111 of the positioning members 101 and 102 of the body frame 2. 121 is a schematic diagram showing step by step how the state is released in this order from 121. FIG.

11(a) to 11(d), as the cover 60 is opened, the positioning pins 73 and 74 located on the device rear side of the support unit 50 move into the concave portions 131 and 131 of the positioning members 103 and 104 of the body frame 2. 14A and 141B are schematic diagrams showing step by step how they are released substantially simultaneously from 141;

In the following, the rotation angle of the cover 60 in the closed state when it opens by rotating around the support shaft 6a is the opening angle θ (°), and the opening angle θ of the cover 60 in the closed state is assumed to be 0°. An operation in which the positioning of the support unit 50 with respect to the body frame 2 is released in the order of the positioning pins 71, 72, 73 (or 74) as θ increases will be specifically described.

When the cover 60 is in the closed state (opening angle θ=0°), the positioning pins 71 to 74 are fitted into the concave portions 111 to 141 of the positioning portions 101 to 104 as shown in FIGS. 10(a) and 11(a). It is

10A, the engaging pins 81 and 82 are loosely fitted in through holes 91 and 92 formed in the front support member 90a of the cover 60. As shown in FIG.

When the open angle θ is 0°, the engagement pins 81 and 82 are in contact with the bottom walls 91a and 92a of the through holes 91 and 92 due to the weight of the support unit 50 itself. As a result, the vertical position of the support unit 50 on the front side of the apparatus is determined. Here, the bottom wall portions 91a and 92a are horizontal wall portions along the X-axis direction when viewed from the front. The length of the bottom wall portion 92a in the left-right direction is approximately 1.5 times the diameter of the engaging pin 82. As shown in FIG. The diameters of the engagement pins 81, 82, 83 are the same.

A side wall portion 91 b on the side closer to the body frame 2 in the lower through-hole 91 is a vertical wall portion along the Y-axis direction (vertical direction) when viewed from the front. approximately twice the diameter. The lower end of the side wall portion 91b and the left end of the bottom wall portion 91a are continuous, and the side wall portion 91b and the bottom wall portion 91a are perpendicular to each other. The drawing shows that the engaging pin 81 is in contact with both the bottom wall portion 91a and the side wall portion 91b of the through hole 91. As shown in FIG. Here, the positioning pin 71 fitted in the recess 111 and the engaging pin 81 in contact with the bottom wall portion 91a of the through hole 91 are arranged in the Y-axis direction (the axial direction of the support shaft 6a). The position is a little off, but you can put it in the same position.

A side wall portion 92b on the side closer to the body frame 2 in the upper through-hole 92 connects a vertical wall portion 92d along the vertical direction in a front view, a lower end 92j of the vertical wall portion 92d, and a left end 92i of the bottom wall portion 92a. It includes an inclined wall portion 92c.

The vertical length of the vertical wall portion 92 d is about 1.5 times the diameter of the engaging pin 82 .

The inclined wall portion 92c is slightly longer than the diameter of the engaging pin 82, and is inclined so that the lower end 92j of the vertical wall portion 92d is positioned obliquely upward when viewed from the left end 92i of the bottom wall portion 92a. tilted at an angle of about 30°. The drawing shows that the engagement pin 82 is in contact with the bottom wall portion 92a of the through hole 92 and not in contact with the inclined wall portion 92c, that is, it is positioned at the lowest position within the through hole 92. FIG.

When the cover 60 is closed as described above, the positioning pins 71 and 72 of the support unit 50 are fitted into the concave portions 111 and 121 of the positioning members 101 and 102 of the body frame 2, and the support unit 50 is engaged. The second timing roller 302 is maintained facing the first timing roller 301 in cooperation with the engaging state of the dowel pins 81 and 82 and the through holes 91 and 92 of the cover 60, and the secondary transfer roller 35 are maintained facing the intermediate transfer belt 21 .

On the other hand, as shown in FIG. 11A, the engagement pin 83 on the device rear side of the support unit 50 is loosely fitted in a through hole 93 formed in the rear side support member 90b of the cover 60. As shown in FIG.

When the opening angle θ is 0°, the engagement pin 83 is in contact with the bottom wall portion 93a of the through hole 93 due to the weight of the support unit 50 itself. As a result, the vertical position of the support unit 50 on the rear side of the apparatus is determined. Here, the through hole 93 has the same size and shape as the through hole 92 . Specifically, the bottom wall portion 93 a is a horizontal wall portion along the X-axis direction, and the length in the left-right direction of the bottom wall portion 93 a is approximately 1.5 times the diameter of the engagement pin 83 .

A side wall portion 93b of the through hole 93 closer to the body frame 2 includes a vertical wall portion 93d and an inclined wall portion 93c connecting a lower end 93j of the vertical wall portion 93d and a right end 93i of the bottom wall portion 93a.

The vertical length of the vertical wall portion 93 d is approximately 1.5 times the diameter of the engaging pin 82 .

The inclined wall portion 93c is slightly longer than the diameter of the engaging pin 83, and is inclined so that the lower end 93j of the vertical wall portion 93d is positioned obliquely upward when viewed from the right end 93i of the bottom wall portion 93a. tilted at an angle of about 30°. In the figure, the engaging pin 83 is in contact with the bottom wall portion 93a of the through hole 93 and not in contact with the inclined wall portion 93c, that is, it is positioned at the lowest position within the through hole 93. FIG.

After the opening operation is started for the cover 60 in the closed state, the side wall of the through hole 91 is opened while the opening angle θ is from 0° to the angle Pa (for example, about 5°) as shown in FIG. 10(b). A pulling force fa along the cover moving direction X' accompanying the rotation of the cover 60 acts on the engaging pin 81 in contact with the portion 91b.

As a result, the opening/closing cover 60 is opened to the opening angle Pa, and the engaging pin 81 moves in the X' direction integrally with the opening/closing cover 60 . When the engaging pin 81 moves, the positioning pin 71, which is provided in the same support unit 50 as the engaging pin 81 and which is positioned closest to the engaging pin 81 in the cover moving direction X', also has a pulling force fa substantially equal to the pulling force fa. A tensile force acts in the X' direction.

Due to the action of the pulling force in the X′ direction on the positioning pin 71 , a downward force fb that resists the biasing force of the compression coil spring 113 acts on the first inclined surface 191 of the lever 112 that is in contact with the positioning pin 71 . Due to the action of this force fb, the lever 112 is slightly lowered from the home position (first position) shown in FIG.

On the other hand, the engaging pin 82 is positioned slightly above the inclined wall portion 92c of the through hole 92, and the engaging pin 82 receives a pulling force from the cover 60 according to the inclination angle of the inclined wall portion 92c. It propagates in a state of being decomposed into an upward direction component and an X′ direction (cover opening direction) component.

The force acting on the engaging pin 82 in the upward direction and the X' direction is also transmitted to the nearest positioning pin 72, but while the engaging pin 82 is ascending the inclined wall portion 92c, the force varies depending on the inclination angle. can only move in the X' direction. On the other hand, since the side wall portion 91b of the through-hole 91 with which the engaging pin 81 abuts is a vertical wall portion, it does not decompose into upward components like the inclined wall portion 92c.

Therefore, the amount of movement of the engaging pins 81 and 82 in the X' direction is considerably smaller for the engaging pin 82 than for the engaging pin 81 when the opening angle reaches Pa. , between the positioning pin 71 closest to the engaging pin 81 and the positioning pin 72 closest to the engaging pin 82 among the positioning pins 71 and 72 .

Therefore, the positioning pin 72 fitted in the concave portion 121 of the body frame 2 is slightly lifted by the component force in the upward direction and the component force in the X′ direction, and remains in the concave portion 121 . That is, the side wall portion 91b (vertical wall portion) of the through hole 91 directly transmits the pulling force in the opening direction (X' direction) from the opening/closing cover 60 to the engaging pin 81, but the inclined wall portion 92c of the through hole 92 Since the pulling force is decomposed into an upward component and a cover opening direction component according to the magnitude of the inclination angle and transmitted to the engaging pin 82, the force in the cover opening direction component becomes considerably small.

In addition, since the upward component force of the inclined wall portion 92c of the through hole 92 is transmitted from the engaging pin 82 to the supporting unit 50, the engaging pin 82 slightly floats and at the same time the supporting unit 50 is engaged with the front side of the apparatus. When the pin 81 is in contact with the side wall portion 91b of the through hole 91, the pin 81 is slightly lifted from the bottom wall portion 91a. At this time, the lower end of the front side of the support unit 50 is tilted slightly in the direction away from the body frame 2 with respect to the upper end.

Since the front side of the device rotates about the support shaft 6a on the back side of the device, the cover 60 moves by a greater amount on the back side of the device even if the opening angle θ is the same between the front side and the back side of the device. Less than the front side of the device.

Therefore, even when the cover 60 is opened to the opening angle Pa, the engagement pin 83 positioned on the rear side of the support unit 50 is slightly above the bottom wall portion 93a of the through hole 93 as shown in FIG. 11(a). The force to push the positioning pins 73, 74 fitted in the recesses 131, 141 of the body frame 2 out of the recesses 131, 141 does not act.

When the opening operation of the cover 60 progresses and the opening angle θ reaches Pb (for example, about 10°) as shown in FIG. As a result, the lever 112 is further lowered, and the positioning pin 71 remains over the top portion 190 of the lever 112 . As a result, the positioning pin 71 comes out of the concave portion 111 in the X' direction, and the positioning of the positioning pin 81 is released.

The position of the lever 112 when the positioning pin 71 has passed over the top portion 190 of the lever 112 is the movement path Pt (chain line ) to the retracted position (second position).

On the other hand, the engaging pin 82 rises to the vicinity of the upper end of the inclined wall portion 92c, and the engaging pin 72 floats considerably in the recess 121 by that amount, but does not protrude from the recess 121 yet. No.

Further, when the opening operation of the cover 60 progresses and the opening angle θ reaches Pc (for example, about 15°) as shown in FIG. . Since the engaging pin 71 is separated from the lever 112 , the lever 112 is returned to the home position (first position on the movement path Pt) by the upward biasing force fc of the compression coil spring 113 .

The engaging pin 82 reaches the vertical wall portion 92d above the inclined wall portion 92c, and moves in the X' direction as the cover 60 opens from the opening angle Pb to Pc. In other words, unlike when climbing the inclined wall portion 92c, the cover 60 can move in the X' direction only by an amount corresponding to the angle of inclination, and moves a distance corresponding to the angle itself at which the cover 60 is opened. As a result, the engaging pin 72 comes out of the concave portion 121 and the positioning of the engaging pin 82 is released.

When the opening angle .theta. , the tensile force of the cover 60 is transmitted in a state of being separated into an upward component and an X' direction (cover opening direction) component according to the inclination angle of the inclined wall portion 93c.

While the engaging pin 83 is ascending the inclined wall portion 93c, it can only move in the X' direction by a distance corresponding to the inclination angle, similarly to the above while the engaging pin 82 is ascending the inclined wall portion 92c. Therefore, the positioning pins 73 and 74 fitted in the concave portions 131 and 141 of the body frame 2 enter the concave portions 131 and 141 only slightly lifted by the upward component force and the X' direction component force. No change from the status quo.

When the opening angle θ reaches from Pc to Pd (for example, about 20°) as shown in FIG. is in a state of considerably floating in the concave portions 131 and 141 . Further, when the opening operation of the opening/closing cover 60 progresses and the opening angle θ reaches Pe (for example, about 25°) as shown in FIG. It reaches the upper vertical wall portion 93d, and moves in the X' direction by the amount that the opening/closing cover 60 is opened from the opening angle Pd to Pe. As a result, the positioning pins 73 and 74 come out of the concave portions 131 and 141 substantially simultaneously, and the positioning of the positioning pins 73 and 74 is released.

Positioning of the four positions by the positioning pins 71 to 74 is performed in such a manner that the positioning pin 71 is released first, then the positioning pin 72 is released, and then the positioning pins 73 and 74 are released. The pull force in the opening direction due to the rotation of is shifted in order of release and acts on each pin.

This is due to the following configuration. That is, the transmission path through which the tensile force required to release the concave-convex fitting from the cover 60 during the opening operation is transmitted to the support unit 50 is the side wall portion 91b (vertical wall surface) of the through hole 91 of the cover 60 and the engagement pin on the front side of the device. 81, a second path through which the vertical wall portion 92d of the through hole 92 engages with the engaging pin 82, and a vertical wall portion 93d of the through hole 93 of the cover 60 on the rear side of the device. It becomes the 3rd path|route which engages with the engagement pin 83. As shown in FIG.

During the opening operation of the cover 60, the pulling force is first transmitted to the first path among the three paths, and the positioning pin 71 is disengaged. are released, and after this release, force is transmitted to the third path, and the positioning pins 73 and 74 are released from the engagement.

In other words, when the cover 60 is rotated from the closed state to the cover opening direction, the pulling force due to the rotation of the cover 60 is first applied from the engagement pin 81 that contacts the side wall portion 91b of the through hole 91 to the position pin closest to the engagement pin 81. 71 (first member to be positioned) is acted to release the fitting (first fitting) with the concave portion 111 (first positioning member).

After releasing the first engagement, when the cover 60 continues to rotate due to the opening operation, the engaging pin 82 moves in the through hole 92 and comes into contact with the vertical wall portion 92d of the through hole 92, and this contact state is reached. The device front side of the support unit 50 is pulled by the cover 60 via the pull force, and the pulling force causes the positioning pin 72 (second positioned member) closest to the engagement pin 82 and the concave portion 121 (second positioning member) to move. The fitting (second fitting) is released.

Further, when the cover 60 continues to rotate due to the opening operation after the second engagement is released, the engaging pin 83 moves in the through hole 93 and contacts the vertical wall portion 93d of the through hole 93. The back side of the support unit 50 is pulled by the cover 60 through the contact state, and the pulling force causes the positioning pins 73 and 74 (third members to be positioned) closest to the engagement pin 83 and the recesses 131 and 141 (third members to be positioned). (third fitting) is released.

The first, second and third positioning members and the first positioning member are arranged so that the support unit 50 can be detached from the body frame 2 by sequentially releasing the first to third fittings. , 2nd and 3rd members to be positioned and the sizes of the through-holes 91, 92 and 93 are determined according to the configuration of the device.

Assuming that the force required to release the positioning at one location is F as described above, in the configuration in which the positioning pins 71 to 74 are released simultaneously, the user must apply a force of (4×F) to the cover 60 at once. .

On the other hand, in the present embodiment, since the four positioning positions are sequentially shifted and released, a maximum force of about (2×F) is required, which is less than the structure in which the four positions are released simultaneously. It becomes easier for the user to open the cover 60, and the operability can be improved accordingly.

In addition, only the positioning portion 101, which is released from positioning first, is provided with a locking mechanism by means of a lever 112 for the concave portion 111 of the positioning pin 71. In the other positioning portions 102, 103, and 104, the openings 122 of the concave portions 121, 131, and 141 are provided. The positioning pins 72, 73, and 74 fall into the recesses 121, 131, and 141 under the weight of the support unit 50, and are supported by the bottom surfaces 123, 133, and 143. , and the number of parts is smaller than the configuration in which lock mechanisms are provided in all four positioning portions, which is advantageous in terms of cost.

Although the case of the opening operation of the cover 60 has been described above, the positioning of the four positions in the case of the closing operation is also shifted in order. Specifically, the positioning pins 73, 74 and the recesses 131, 141 are first fitted and positioned, then the positioning pin 72 and the recess 121 are fitted and positioned, and finally the positioning pin 71 and the recess are positioned. 111 are fitted and positioned.

12(a) to 12(c), as the closing operation of the cover 60 in the open state progresses, the positioning pins 73 and 74 positioned on the device back side of the support unit 50 move toward the positioning members 103 and 104 of the body frame. FIG. 10 is a schematic diagram showing step by step how the recesses 131 and 141 are fitted substantially simultaneously.

13(a) to 13(c), as the cover 60 is closed, the positioning pins 71 and 72 positioned on the front side of the support unit 50 move toward the concave portions of the positioning members 101 and 102 of the body frame 2. As shown in FIGS. FIG. 11 is a schematic diagram showing step by step how the positioning pins 72 and 71 are fitted to 111 and 121 in a shifted order.

In the following, the rear side of the device and the front side will be described in this order.

As shown in FIG. 12(a), when the cover 60 rotates in the direction of the arrow X (cover closing direction) on the rear side of the apparatus, the opening angle θ of the cover 60 becomes Pf (for example, about 20°). The dowel pin 83 hits the side wall portion 93e of the through hole 93, and the support unit 50 is pushed in the arrow X direction by the side wall portion 93e. Here, the side wall portion 93e is a vertical wall portion (third hole edge portion) located on the opposite side of the vertical wall portion 93d in the through hole 93 in the cover closing direction.

As a result, the positioning pins 73 and 74 of the support unit 50 approach the concave portions 131 and 141 of the positioning portions 103 and 104 of the body frame 2 . When the positioning pins 73 and 74 approach the recesses 131 and 141, the positioning pins 73 and 73 are placed on the inclined surfaces 137 and 147 (FIGS. 8 and 9) on the body frame 2 side located upstream of the recesses 131 and 141 in the cover closing direction. 74 rides up. As a result, the positioning pins 73 and 74 are guided obliquely upward on the inclined surfaces 137 and 147 as the cover 60 is closed. When the cover 60 moves in the cover closing direction up to the opening angle Pg (<Pf) shown in FIG. 73 , 74 lead to openings 132 , 142 of recesses 131 , 141 .

Further, when the cover 60 moves in the cover closing direction up to the opening angle Ph (<Pg) shown in FIG. The weight of the unit 50 causes it to fall into the recesses 131 and 141 .

reaches Ph, the engaging pin 82 hits the side wall portion 92e of the through hole 92 and the engaging pin 81 contacts the side wall portion 91e of the through hole 91 as shown in FIG. 13(a). hit. Here, the side wall portion 92e is a vertical wall portion (second hole edge portion) located on the opposite side of the vertical wall portion 92d in the through hole 92 in the cover closing direction (arrow X direction). The side wall portion 91e is an inclined wall portion (first hole edge portion) located on the side opposite to the side wall portion 91b, which is the vertical wall portion, in the through hole 91 in the cover closing direction (the arrow X direction).

As a result, the side wall portion 92e, which is a vertical wall portion, applies a pressing force due to the rotation of the cover 60 in the cover closing direction to the engaging pin 82 as it is. Depending on the angle, component forces act in the cover closing direction and obliquely upward direction.

When the positioning pin 72 approaches the recess 121 as the cover 60 continues to close, the positioning pin 72 rides on the inclined surface 127 (FIG. 7) of the body frame 2 located upstream of the recess 121 in the cover closing direction. As a result, the positioning pin 72 is guided obliquely upward on the inclined surface 127 as the cover 60 is closed.

When the closing operation of the cover 60 progresses and reaches the opening angle Pi (<Ph) shown in FIG. It falls into the concave portion 121 . At this time, the positioning pin 71 is pressing the top portion 190 of the lever 112 downward and does not enter the concave portion 111 of the positioning portion 101 .

When the closing operation of the cover 60 progresses further and reaches the opening angle Pj (<Pi) shown in FIG. Pushed inside through the opening. Further, when the closing operation progresses and the opening angle θ becomes 0°, the positioning pin 71 is fitted into the concave portion 111 as shown in FIG. 10A, and the cover 60 is closed. The positional relationship of the side walls 91e, 92e, and 93e of the through holes 91, 92, and 93 in the cover closing direction is determined so that the positioning pins are fitted into the concave portions in the order described above.

In this way, even when the cover 60 is closed, each positioning is performed in a staggered order, so that the user does not need to apply a large force to the cover 60 at once unlike the configuration in which four positions are positioned simultaneously. It becomes easier to perform the closing operation.

<Modification>
Although the present invention has been described above based on the embodiments, the present invention is of course not limited to the above configuration, and the following modifications are conceivable.

(1) In the above-described embodiment, a configuration example in which the positioning member on the main body frame 2 side is a concave portion and the member to be positioned on the support unit 50 side is a convex portion has been described, but the present invention is not limited to this. The positioning may be performed by fitting the positioning member on the main body side and the positioning target on the supporting unit side. For example, it is possible to adopt a configuration in which a convex portion such as a pin is provided on the main body side, and a concave portion into which the convex portion is fitted is provided on the support unit side.

(2) In the above embodiment, as connecting means for connecting the support unit 50 to the cover 60, the engagement pins (engagement projections) 81 to 83 provided on the support unit 50 are provided in the cover 60 through the through holes 91 to 93. Although a configuration example of loose fitting has been described, the present invention is not limited to this. For example, it is possible to adopt a configuration in which an engagement projection is provided on the cover 60 side, and a through hole is provided on the support unit 50 side into which the engagement projection on the cover 60 side is loosely fitted.

(3) In the above-described embodiment, during the opening operation of the cover 60, of the two positioning portions 101 and 102 on the front side of the device and the two positioning portions 103 and 104 on the back side of the device, the positioning portion 101, 102 are released in this order, and then the positioning portions 103 and 104 are released at the same time, but the configuration is not limited to this.

For example, one of the positioning units 103 and 104 can be released earlier than the other while the order of releasing the positioning units 101 and 102 remains unchanged. Further, a configuration is also conceivable in which the positioning sections 103 and 104 are released substantially simultaneously with the release of the positioning section 102, while the order of releasing the positioning sections 101 and 102 remains unchanged. In this case, after the positioning portion 101 is released, the three positions are released at the same time, but the force applied by the user when opening the cover 60 can be reduced as compared with the configuration in which the four positions are released at the same time.

(4) In the above embodiment, the positioning unit 101 on the front side of the apparatus is positioned upstream of the positioning unit 102 in the sheet conveying direction, and the positioning unit 104 on the rear side of the apparatus is positioned upstream of the positioning unit 103 in the sheet conveying direction. Although an example configuration has been described, it is not limited to this.

For example, the positioning section 101 may be positioned downstream of the positioning section 102 in the sheet conveying direction, and the positioning section 104 may be positioned downstream of the positioning section 103 in the sheet conveying direction.

Further, instead of the configuration having four positioning portions, for example, three positioning portions, specifically, two positioning portions are provided along the sheet conveying direction on the front side of the device, and one positioning portion is provided on the back side of the device. It is also possible to adopt a configuration in which they are provided.

(5) In the above embodiment, the positional relationship between the positioning pins 71 and 72 and the engaging pins 81 and 82 on the front side of the apparatus is set in the Y-axis direction (the axial direction of the support shaft 6a) as shown in FIG. 10(d). equivalent), passing through the intermediate position between the first position of the positioning pin 71 (first member to be positioned) and the second position of the positioning pin 72 (second member to be positioned) and perpendicular to the Y-axis direction. An engaging pin 81 (first engaging protrusion) is located on one side of the sandwich, which is closer to the positioning pin 71 , and an engaging pin 82 (first engaging protrusion) is located on the other side, which is farther from the positioning pin 71 (closer to the positioning pin 72 ). 2) is positioned, and the distance between the engaging pin 81 and the virtual plane Pm is substantially the same as the distance between the engaging pin 82 and the virtual plane Pm. No. The positional relationship may be such that the positioning portions 101 and 102 are released in this order. For example, the above distance may be the same or slightly different.

(6) In the above-described embodiment, a configuration example in which the through holes 91 and 92 into which the engaging pins 81 and 82 of the support unit 50 are loosely fitted is provided in the front support member 90a of the cover 60 on the front side of the apparatus. However, it is not limited to this. If the positioning portions 101 and 102 can be released in this order, instead of loosely fitting the engaging pin 81 into the through hole 91, for example, a snug fit may be used, or the engaging pin 81 may be fixedly supported by the supporting member 90a. It would also be possible to have a configuration.

(7) In the above embodiment, an example of the configuration of a printer as an image forming apparatus has been described. It can be applied to image forming apparatuses such as copiers and facsimile machines.

Also, a configuration example in which a first timing roller 301 as a first conveying member is provided on the body frame 2 and a second timing roller 302 as a second conveying member is provided in a support unit 50 separable from the body frame 2 will be described. However, it is not limited to this. For example, one of the first and second conveying members may be a roller for conveying the sheet S and the other may be a guide for guiding the sheet S, or both may be guides.

In addition, although a configuration example in which a side-opening type cover is provided on the right side of the printer has been described, the present invention is not limited to this, and a configuration in which the cover is provided on the left side, the front, the back, etc., for example, can also be adopted. In addition, for example, in the case of a configuration including a conveying device that conveys sheets along a horizontal conveying path to a post-processing device that performs post-processing such as stapling a bundle of sheets after printing, support along the conveying path is required. It can also be applied to an opening/closing cover that rotates about an axis to open and close the conveying path.

Furthermore, the size and shape of each member such as the positioning pin, the recess, the engaging pin, and the through hole are not limited to those described above, and the size and shape suitable for the device configuration can be determined.

Also, the configurations of the above embodiment and the above modifications may be combined as much as possible.

The present invention can be applied to an image forming apparatus that forms an image on a conveyed sheet.

1 printer 3 exterior cover (exterior body)
3a opening 6a support shaft 50 support unit 60 opening/closing cover 71, 72, 73, 74 positioning pin (member to be positioned)
81, 82, 83 engagement pins (engagement projections)
91, 92, 93 Through hole 91b, 92d, 93d Side wall of through hole (hole edge)
91e, 92e, 93e side wall of through hole (first, second, third hole edge)
111, 121, 131, 141 recess (positioning member)
113 Compression coil spring (biasing member)
117 lever Pm virtual plane Pt movement path S sheet Sa sheet passing area

Claims (10)

An image forming apparatus for forming an image on a conveyed sheet,
a sheet conveying path configured by facing a first conveying member and a second conveying member;
a body frame of an image forming apparatus on which the first conveying member is installed;
an exterior body of an image forming apparatus having an opening corresponding to an installation location of the first conveying member;
a cover rotatably provided on a support shaft along the sheet conveying direction at the edge of the opening and capable of freely opening and closing the opening;
a support unit that supports the second conveying member facing the first conveying member so as to be positioned on the cover side when the cover is in the closed state;
with
The support unit has first and second positioned members that can be engaged with and released from first and second positioning members provided along the sheet conveying direction on the body frame side, and First and second engaging projections loosely fitted in first and second through holes provided in the cover, or first and second engaging projections loosely fitted in the first and second engaging projections provided in the cover. 2 through- holes,
When the cover is in the closed state, the first and second positioned members are in first and second mating states in which the first and second positioning members are fitted to each other. While maintaining the second conveying member facing the first conveying member in cooperation with the engagement state between the second engaging projection and the first and second through holes,
When the cover is rotated in the opening direction from the closed state, the pulling force due to the rotation of the cover causes the first engaging projection to move in the first through-hole and close to the edge of the first through-hole. Through this contact state, the support unit is pulled by the cover, the pulling force releases the first engagement, and the rotation of the cover continues, the second engagement occurs. The projection moves in the second through hole and abuts against the hole edge of the second through hole, and the supporting unit is pulled by the cover through this abutting state. The positional relationship and the sizes of the first and second through- holes are such that the first and second positioning members and the first and second positioned members are released from the engagement so as to release the engagement. is stipulated and
The first and second positioning members are arranged on the body frame on the side farther from the spindle in the width direction of the sheet across the sheet passage area of the sheet,
the body frame has a third positioning member on a side close to the support shaft across the sheet passing area in the width direction of the sheet;
The support unit includes a third positioned member that can be engaged with and disengaged from the third positioning member, and a side close to the support shaft across a sheet passing area in the width direction of the sheet, a third engaging projection loosely fitted in a third through hole provided in the cover, or a third through hole loosely fitting the third engaging projection provided in the cover;
When the cover is in the closed state, the third positioned member is in the third fitted state in which the third positioning member is fitted, and the third engaging projection and the third through hole are in the third fitted state. cooperating with the engaged state to maintain the second conveying member facing the first conveying member;
Until the second fitting is released, the third engaging projection moves in the third through hole and does not abut against the hole edge of the third through hole. After the engagement is released, if the cover continues to rotate, the third engaging projection moves and comes into contact with the edge of the third through hole, and through this abutting state, the support is provided. The third positioning member and the third member to be positioned have a positional relationship leading to release of the engagement and the third positioning member so that the side of the unit near the support shaft is pulled by the cover to release the third engagement. 3. An image forming apparatus characterized in that the sizes of the through holes 3 are determined . The body frame further includes a fourth positioning member provided on the side close to the support shaft across the sheet passing area in the width direction of the sheet and on the upstream side or the downstream side in the sheet conveying direction with respect to the third positioning member. having a positioning member of
The support unit further has a fourth positioned member that can be engaged with and released from the fourth positioning member,
When the cover is in the closed state, the fourth positioned member is also fitted to the fourth positioning member,
The fourth positioning member and the fourth member to be positioned are arranged such that the engagement between the fourth member to be positioned and the fourth positioning member is also released when the third fitting is released. 2. The image forming apparatus according to claim 1 , wherein the positional relationship and the size of said third through-hole until the fitting is released are determined. The hole edge portion of the first through hole on the side opposite to the hole edge portion of the first through hole that comes into contact with the first engaging projection as the cover is opened is moved in the direction of rotation of the cover. The hole edge portion of the second through hole opposite to the hole edge portion of the second through hole that abuts on the first hole edge portion and the second engagement projection is the second hole edge portion of the second through hole on the opposite side in the rotation direction of the cover. hole edge, the hole edge of the third through hole on the side opposite to the hole edge of the third through hole in contact with the third engaging projection, in the direction of rotation of the cover, is referred to as a third hole edge; When the part is
When the cover rotates in the closing direction opposite to the opening direction from the open state and is returned to the closed state, the support unit is first contacted by the third engaging projection and the third hole edge. is pushed by the cover, the pressing force engages the third positioned member with the third positioning member, and after this engagement, when the rotation in the closing direction continues, the second engagement occurs. The support unit is pressed against the cover by the contact between the protrusion and the second hole edge, and the pressing force causes the second positioned member to fit into the second positioning member. After that, when the rotation in the closing direction continues, the supporting unit is pushed by the cover due to the contact between the first engaging projection and the edge of the first hole, and the pushing force pushes the first positioned member. 2. An image forming apparatus according to claim 1 , wherein the positional relationship in the closing direction of said first, second and third hole edge portions is determined so that said first positioning member is fitted with said first positioning member. Device. An image forming apparatus for forming an image on a conveyed sheet,
a sheet conveying path configured by facing a first conveying member and a second conveying member;
a body frame of an image forming apparatus on which the first conveying member is installed;
an exterior body of an image forming apparatus having an opening corresponding to an installation location of the first conveying member;
a cover rotatably provided on a support shaft along the sheet conveying direction at the edge of the opening and capable of freely opening and closing the opening;
a support unit that supports the second conveying member facing the first conveying member so as to be positioned on the cover side when the cover is in the closed state;
with
The support unit has first and second positioned members that can be engaged with and released from first and second positioning members provided along the sheet conveying direction on the body frame side, and First and second engaging projections loosely fitted in first and second through holes provided in the cover, or first and second engaging projections loosely fitted in the first and second engaging projections provided in the cover. 2 through- holes,
When the cover is in the closed state, the first and second positioned members are in first and second mating states in which the first and second positioning members are fitted to each other. While maintaining the second conveying member facing the first conveying member in cooperation with the engagement state between the second engaging projection and the first and second through holes,
When the cover is rotated in the opening direction from the closed state, the pulling force due to the rotation of the cover causes the first engaging projection to move in the first through-hole and close to the edge of the first through-hole. Through this contact state, the support unit is pulled by the cover, the pulling force releases the first engagement, and the rotation of the cover continues, the second engagement occurs. The projection moves in the second through hole and abuts against the hole edge of the second through hole, and the supporting unit is pulled by the cover through this abutting state. The positional relationship and the sizes of the first and second through- holes are such that the first and second positioning members and the first and second positioned members are released from the engagement so as to release the engagement. is stipulated and
The first and second engagement projections are provided on the support unit,
The first and second through holes are provided in the cover,
The support shaft is a shaft along the vertical direction,
A hole edge portion of the first through hole is a first vertical wall portion,
A hole edge portion of the second through-hole is a second vertical wall portion that is continuous with an inclined wall portion of the second through-hole that inclines obliquely upward as it advances in a direction opposite to the opening direction of the cover. and
The image forming apparatus , wherein the second vertical wall portion is located upstream of the first vertical wall portion in an opening direction of the cover . An image forming apparatus for forming an image on a conveyed sheet,
a sheet conveying path configured by facing a first conveying member and a second conveying member;
a body frame of an image forming apparatus on which the first conveying member is installed;
an exterior body of an image forming apparatus having an opening corresponding to an installation location of the first conveying member;
a cover rotatably provided on a support shaft along the sheet conveying direction at the edge of the opening and capable of freely opening and closing the opening;
a support unit that supports the second conveying member facing the first conveying member so as to be positioned on the cover side when the cover is in the closed state;
with
The support unit has first and second positioned members that can be engaged with and released from first and second positioning members provided along the sheet conveying direction on the body frame side, and First and second engaging projections loosely fitted in first and second through holes provided in the cover, or first and second engaging projections loosely fitted in the first and second engaging projections provided in the cover. 2 through- holes,
When the cover is in the closed state, the first and second positioned members are in first and second mating states in which the first and second positioning members are fitted to each other. While maintaining the second conveying member facing the first conveying member in cooperation with the engagement state between the second engaging projection and the first and second through holes,
When the cover is rotated in the opening direction from the closed state, the pulling force due to the rotation of the cover causes the first engaging projection to move in the first through-hole and close to the edge of the first through-hole. Through this contact state, the support unit is pulled by the cover, the pulling force releases the first engagement, and the rotation of the cover continues, the second engagement occurs. The projection moves in the second through hole and abuts against the hole edge of the second through hole, and the supporting unit is pulled by the cover through this abutting state. The positional relationship and the sizes of the first and second through- holes are such that the first and second positioning members and the first and second positioned members are released from the engagement so as to release the engagement. is stipulated and
An imaginary plane that passes through an intermediate position between the first position of the first positioned member and the second position of the second positioned member in the axial direction of the support shaft and is perpendicular to the axial direction The first engaging projection is positioned on one side closer to one positioned member, and the second engaging projection is positioned on the other side farther from the first positioned member . Image forming device. The first positioned member is positioned upstream in the sheet conveying direction from the second positioned member, and the first engaging projection is positioned upstream in the sheet conveying direction from the second engaging projection. 6. The image forming apparatus according to claim 5 , wherein the image forming apparatus is located at . An image forming apparatus for forming an image on a conveyed sheet,
a sheet conveying path configured by facing a first conveying member and a second conveying member;
a body frame of an image forming apparatus on which the first conveying member is installed;
an exterior body of an image forming apparatus having an opening corresponding to an installation location of the first conveying member;
a cover rotatably provided on a support shaft along the sheet conveying direction at the edge of the opening and capable of freely opening and closing the opening;
a support unit that supports the second conveying member facing the first conveying member so as to be positioned on the cover side when the cover is in the closed state;
with
The support unit has first and second positioned members that can be engaged with and released from first and second positioning members provided along the sheet conveying direction on the body frame side, and First and second engaging projections loosely fitted in first and second through holes provided in the cover, or first and second engaging projections loosely fitted in the first and second engaging projections provided in the cover. 2 through- holes,
When the cover is in the closed state, the first and second positioned members are in first and second mating states in which the first and second positioning members are fitted to each other. While maintaining the second conveying member facing the first conveying member in cooperation with the engagement state between the second engaging projection and the first and second through holes,
When the cover is rotated in the opening direction from the closed state, the pulling force due to the rotation of the cover causes the first engaging projection to move in the first through-hole and close to the edge of the first through-hole. Through this contact state, the support unit is pulled by the cover, the pulling force releases the first engagement, and the rotation of the cover continues, the second engagement occurs. The projection moves in the second through hole and abuts against the hole edge of the second through hole, and the supporting unit is pulled by the cover through this abutting state. The positional relationship and the sizes of the first and second through- holes are such that the first and second positioning members and the first and second positioned members are released from the engagement so as to release the engagement. is stipulated and
The first positioned member is a first positioning pin,
The first positioning member has a first recess into which the first positioning pin is fitted,
The first recess is open on the downstream side in the opening direction of the cover,
The body frame is
A first position on the movement path of the first positioning pin that moves in the opening direction of the cover from the opening of the first recess in accordance with the opening operation of the cover, and a second position that retreats from the movement path. and a biasing member that biases the lever member in a direction from the second position toward the first position,
The lever member is positioned at the first position when the cover is closed, and applies a pressing force to the bottom of the recess to the first positioning pin fitted in the first recess. When the opening operation of the cover is started, the first positioning pin, which has started to move in the opening direction, pushes the inclined surface to resist the biasing force of the biasing member. and retracting from the first position to the second position . The positions of the first positioning pin and the first engaging projection in the first fitting state fitted in the first recess in the axial direction of the support shaft are the same. Item 8. The image forming apparatus according to item 7 . The second positioned member is a second positioning pin,
the second positioning member has a second recess into which the second positioning pin is fitted;
The second recess is opened in a direction inclined by a predetermined angle downstream in the opening direction of the cover with respect to the axial direction of the support shaft, and the bottom surface is closed. The image forming apparatus according to any one of items 1 to 3. The image forming apparatus according to any one of claims 1 to 9 , wherein the first and second conveying members are first and second rollers that nip and convey the sheet.

Images