JP6341700B2 - Sheet supply method, apparatus relating to this method, and auxiliary sheet - Google Patents

Description

  The present invention relates to an image forming apparatus (hereinafter referred to as a printer) that forms an image on a cut sheet. In particular, the present invention relates to an auxiliary sheet that assists manual sheet feeding of a cut sheet toward a conveyance roller that conveys the cut sheet, and a cut sheet conveyance system to which the auxiliary sheet can be applied.

  Some printers are capable of printing on cut sheets supplied by a user. If a cut sheet with low rigidity is used, the cut sheet may buckle during feeding, and the leading edge of the cut sheet may not reach the pair of conveying rollers. In such a case, a device for assisting the cut sheet is required so that the cut sheet being fed does not buckle.

  In Patent Document 1, a cut sheet (also referred to as cut sheet paper) is placed on the front surface of the mount, and the rear end of the cut sheet in the conveyance direction is inserted into and held in a notch formed on the mount. Is disclosed.

Utility model registration No. 3069033 (see Fig. 3)

In an ink jet image forming apparatus, a sheet on which printing is performed may absorb ink moisture and wave on the platen and partially float. In order to reduce this, a suction platen that sucks the back surface of the sheet with a negative pressure during image formation is known.
When the mount described in Patent Document 1 is supported by the suction platen, the mount is interposed between the sheet and the negative pressure suction port of the platen, so that suction force does not act on the back surface of the sheet. For this reason, when the technique described in Patent Document 1 is used in an apparatus having a suction platen, there is a possibility that an image defect or a paper jam may occur due to sheet floating.
Accordingly, the present invention provides a sheet supply method that can prevent buckling of a sheet supplied to a processing unit such as an image forming unit or an image reading unit, and can reliably perform processing such as image formation or image reading. With the goal.

One aspect of the present invention attaches a processing unit that performs processing on a sheet, a conveyance unit that is arranged upstream of the processing unit in the conveyance direction of the sheet, and conveys a sheet that is processed by the processing unit. And a processing device in which the sheet to be processed is attached to the auxiliary sheet such that the leading edge of the sheet to be processed is downstream of the leading edge of the auxiliary sheet in the transport direction. And a regulating means for regulating movement of the auxiliary sheet so that the leading edge of the auxiliary sheet does not reach the conveying means after the leading edge of the sheet to be processed reaches the conveying means. To do .

  According to the present invention, since only the cut sheet is taken out from the supplied auxiliary sheet and conveyed, buckling of the sheet supplied to the processing unit can be prevented, and processing such as image formation and image reading can be performed reliably. A sheet feeding method is realized.

1 is a schematic cross-sectional configuration diagram of a printer apparatus main body according to a first embodiment. The figure for demonstrating the auxiliary sheet which concerns on a 1st Example. The figure for demonstrating the auxiliary sheet which concerns on a 1st Example. FIG. 3 is a perspective view illustrating a state when sheet feeding is completed in the first embodiment. The perspective view which showed the mode at the time of printing of the sheet | seat in a 1st Example. FIG. 6 is a schematic cross-sectional configuration diagram of a printer apparatus main body according to a second embodiment. FIG. 9 is a perspective view illustrating a state when sheet feeding is completed in a second embodiment. The schematic cross-section block diagram of the clip mechanism part which is a control means in 2nd Example.

(First embodiment)
FIG. 1 shows a schematic sectional configuration of a printer (image forming apparatus) in a first embodiment of the present invention. The printer apparatus main body 1 includes an image forming unit 3 (processing unit) that forms an image on a sheet S (cut sheet made of paper or resin), a conveying roller 8 that conveys the sheet S, and a sheet S on the conveying roller 8. A pinch roller 9 that rotates following the pressing and conveying roller 8 is provided.
The sheet conveying means including the conveying roller 8 and the pinch roller 9 is installed only upstream of the image forming unit 3 in the conveying direction of the sheet S. Further, the printer apparatus main body 1 includes a conveyance guide pair 22 for guiding and supplying the sheet S toward such a sheet conveyance unit, and a sheet feeding unit that allows the sheet S to be inserted into a space between the conveyance guide pair 22. 20 and a sheet feeding path (sheet supply path). The image forming unit 3 supports a head 4 that ejects ink by an inkjet method, a carriage 5 that is mounted with the head 4 and can reciprocate in the width direction (main scanning direction) of the sheet S, and supports the sheet S from the back side. And a platen 6 that holds the sheet S in a substantially flat surface by negative pressure suction. A detection sensor 7 for detecting the sheet S is installed in the conveyance path between the conveyance guide pair 22 on the upstream side of the image forming unit 3. A conveyance guide 80 is installed slightly upstream of the conveyance roller pair 8 and 9. The conveyance guide 80 is a guide member made of a metallic magnetic material (for example, SUS430), and is installed adjacent to the lower conveyance guide 22. The conveyance guide 80 guides the leading edge of the sheet S being fed to a portion (hereinafter referred to as a nip portion) that sandwiches the sheet S of the conveyance roller pairs 8 and 9.

Next, an image forming process in the printer including the above-described components will be described with reference to FIG.
The sheet S is inserted from the supply unit 20 by the user's hand and guided to the nip portion of the conveyance roller pair 8 and 9 via the conveyance guide pair 22. Such user action is called manual paper feeding. Thereafter, the sheet S sandwiched between the transport roller pairs 8 and 9 is transported downstream in the transport direction as the transport roller 8 is driven to rotate, and the image forming unit 3 forms an image on the sheet S. Done. When ink lands on the sheet S, the sheet S absorbs the moisture of the ink and expands, and tries to deform in the direction of floating from the platen 6. For this reason, by lifting the sheet S to the platen surface through the negative pressure suction port formed on the platen surface that supports the back surface of the sheet S, the above-described floating of the sheet S is suppressed, and the sheet S and the head 4 contact is prevented. In the image forming unit 3, the carriage 5 is moved forward or backward in the main scanning direction while the conveyance of the sheet S is stopped. At that time, ink droplets are ejected from the head 4 to the sheet S to print one line. Do. When printing for one line is completed, the sheet S is conveyed by a predetermined amount in the direction of the arrow (sub-scanning direction) perpendicular to the main scanning direction, and the carriage 5 moves forward or backward again to continue. Is printed for one line. In this way, the sheet S is repeatedly formed and image formation is performed for each line while repeating intermittent conveyance.
In the printer of this embodiment, it is desired to prevent the sheet S from buckling when the user feeds the sheet S from the paper feeding unit 20 to the pair of conveying rollers 8 and 9. For this purpose, an auxiliary sheet 70 that assists paper feeding that can be attached to the sheet S by the user is prepared as an accessory (attachment) of the printer.

FIG. 2 is a diagram illustrating a state in which the auxiliary sheet 70 is attached to the large size sheet S, and FIG. 3 is a diagram illustrating a state in which the auxiliary sheet 70 is attached to the small size sheet S. 2 and 3, (a) shows a schematic cross section in a state where the auxiliary sheet 70 is attached to the sheet S, and (b) is a back view of the state shown in (a). . Moreover, (a) of each figure is sectional drawing in XX 'shown to (b).
The auxiliary sheet 70 includes a rectangular base sheet 71, a holding part that holds the sheet S formed on the base sheet 71, and a magnet 72 that is disposed on a part of the base sheet 71 outside the holding part. And comprising. As the base sheet 71, a PET sheet having higher rigidity than cut paper or vinyl chloride sheet can be adopted. The base sheet 71 is disposed on the printing surface side of the sheet S and has a width larger than the width of the sheet S. The holding portion is a portion that detachably holds the trailing edge Sb of the sheet S and the two side edges Sc and Sd adjacent to the trailing edge Sb with the leading edge Sa of the sheet S in a free state. . Specifically, the holding portion is formed on the base sheet 71 and has a plurality of cuts into which the rear end edge Sb and the side end edges Sc and Sd of the sheet S can be inserted and removed. A tongue-like piece 72 is formed on the base sheet 71 by cutting, and each of the side edges Sc and Sd of the sheet S is pressed against the base sheet 71 by the elasticity of the tongue-like piece 72. Note that a plurality of tongue-like pieces 72 are provided in the sheet width direction so as to correspond to the external sizes (B5 plate, A4 plate, etc.) of a plurality of types of sheets S (see FIG. 3). Furthermore, a plurality of tongue pieces 72 may be provided not only in the width direction of the sheet S but also in the sheet conveying direction.
Further, the base sheet 71 is provided with a notch 77 that is inclined with respect to the conveying direction of the sheet S. This notch 77 is a holding portion that inserts and holds the two corners of the trailing edge Sb of the sheet S, and corresponds to the external size (B5 version, A4 version, etc.) of the plurality of types of sheets S. A plurality are provided. In a state where the corner portion of the trailing edge of the sheet S is inserted into the notch 77, the notch 77 is arranged such that the leading edge Sa of the sheet S is separated from the leading edge 75 of the auxiliary sheet 70 by about 20 mm downstream in the transport direction. The position is designed. Therefore, as can be seen by comparing FIG. 2B and FIG. 3B, the positions of the notches 77 corresponding to the various sheets S are different in both the width direction and the conveyance direction of the sheets S.
The user places the auxiliary sheet 70 on the sheet S and manually feeds the sheet S while holding the trailing edge Sb and the side edges Sc and Sd of the sheet S by the holding unit. The buckling of the sheet S is suppressed by the rigidity of the base sheet 71 when the sheet S is fed to the nip portion of the pair of conveying rollers 8 and 9.

Next, a flow when paper is fed using the auxiliary sheet 70 will be described with reference to FIGS. 1, 4, and 5. FIG. 4 is a perspective view showing a state when the sheet S is fed to the pair of conveying rollers 8 and 9 using the auxiliary sheet 70, and FIG. 5 is printed on the sheet S after feeding. It is the perspective view which showed the mode.
When the sheet S is fed together with the auxiliary sheet 70 from the sheet feeding unit 20 through the conveyance guide pair 22 by the user's hand, the leading edge of the sheet S in the sheet feeding direction comes into contact with the conveyance roller pairs 8 and 9. . As a result, the sheet S takes a posture perpendicular to the conveying roller pair 8 and 9.
When the sheet detection sensor 7 installed upstream of the conveying roller pair 8 and 9 detects the sheet S, the conveying roller pair 8 and 9 rotate by a predetermined amount (corresponding to about 5 mm) after a while. This state is shown in FIG. 4, and the leading end portion of the sheet S is sandwiched between the nip portions of the conveying roller pairs 8 and 9 by this rotational drive. In this state, the leading end portion of the auxiliary sheet 70 is located immediately above the conveyance guide 80 disposed slightly upstream from the conveyance roller pair 8 and 9. The conveyance guide 80 is made of a magnetic material (for example, SUS430). Sheet-like magnets 76 are fixed to the surfaces of the auxiliary sheet 70 in the vicinity of both ends of the leading edge 75 and facing the conveyance guide 80. Accordingly, the magnet 76 of the auxiliary sheet 70 is attracted to the conveyance guide 80, and the auxiliary sheet 70 cannot advance downstream in the conveyance direction. That is, the auxiliary sheet 70 is fixed to the conveyance guide 80 by the magnetic force, and the leading edge 75 of the auxiliary sheet 70 is separated from the peripheral surface of the conveyance roller 8. On the other hand, the sheet S is conveyed downstream in the conveying direction by receiving the conveying force due to the rotation of the conveying roller 8. In this case, the conveying force is set to be sufficiently larger than the holding force generated in the sheet S by the tongue-like piece 72 and the notch 77 of the auxiliary sheet 70.
As described above, the sheet S is automatically separated from the auxiliary sheet 70 to be conveyed and printed, and the auxiliary sheet 70 stays in the space (sheet supply path) between the conveying guide pair 22 (FIG. 5). State). The auxiliary sheet 70 is pulled out by the user's hand from the paper feeding unit 20 in the direction opposite to the paper feeding direction and collected.

As described above, by using the auxiliary sheet 70, manual sheet feeding can be performed without causing a sheet feeding failure to the nip portion of the pair of conveying rollers 8 and 9. Further, only the sheet S is conveyed from the auxiliary sheet 70 to the image forming unit 3 by the conveying roller 8. For this reason, unlike the prior art described above, the auxiliary sheet 70 is not interposed between the sheet S and the platen 6 during image formation, and the negative suction force against the back surface of the sheet S is not hindered.
In the present embodiment, the form in which the auxiliary sheet 70 is disposed so as to overlap the printing surface side of the sheet S has been described. By arranging the auxiliary sheet 70 on the printing surface side in this way, the printing surface of the sheet S does not come into direct contact with the conveyance guide pair 22, so that generation of scratches on the printing surface and adhesion of dust such as paper dust are prevented. There is an effect to prevent. However, if the auxiliary sheet 70 is used only for the purpose of preventing buckling of the sheet S during feeding, the auxiliary sheet 70 is not limited to being arranged on the printing surface side of the sheet S, and printing of the sheet S is not limited. You may arrange | position to the surface on the opposite side to a surface.
In the first embodiment, the restricting means for restricting the contact of the auxiliary sheet 70 with the conveying roller 8 uses magnetic attraction force. That is, as described above, the auxiliary sheet 70 is provided with a sheet-like magnet 76 (magnetic body), and the conveyance guide 80 is made of a magnetic material. However, the restricting means using the magnetic attractive force is not limited to the configuration described above. For example, a magnetic magnet that attracts the magnet 76 may be installed on the conveyance guide 80, or the magnet 76 of the auxiliary sheet 70 is replaced with a steel sheet (magnetic material), and the conveyance guide 80 includes the steel sheet. You may install the magnet which attracts. According to these alternatives, the conveyance guide 80 can be formed of resin. After all, it is only necessary to construct a means for attracting the auxiliary sheet 70 by magnetism so that the leading edge of the auxiliary sheet 70 in the sheet feeding direction is held at a position away from the conveying roller 8 to the upstream side. The position of the magnet 76 of the auxiliary sheet 70 is not limited to the position shown in FIG. However, a portion to be attracted (magnet 76, steel sheet, magnetic metal, etc.) that can be attracted by magnetism is disposed on a sheet portion of the auxiliary sheet 70 outside the holding portion. This is because the sheet S is not sandwiched between the magnet 76 and the conveyance guide 80 when the auxiliary sheet 70 is fixed to the conveyance guide 80.

(Second embodiment)
Further, a second embodiment will be described. Here, the description of the same points as in the first embodiment will be omitted, and only the different points will be described. The auxiliary sheet 70 used in the second embodiment is the same as that of the first embodiment. However, the second embodiment is different from the first embodiment in that the auxiliary sheet 70 is fed during sheet feeding. The restricting means for restricting the auxiliary sheet 70 is different so that the front end portion does not contact the pair of conveying rollers 8 and 9. The restricting means of the second embodiment will be described below with reference to FIGS. FIG. 6 is a schematic cross-sectional configuration diagram of the printer apparatus main body of the second embodiment, FIG. 7 is a perspective view showing a state when the sheet feeding is completed in the second embodiment, and FIG. 8 is a restriction of the second embodiment. It is a schematic sectional block diagram of the clip mechanism part as a means.

  As shown in FIGS. 6 to 8, a clip mechanism 90 (gripping unit) is provided slightly upstream of the conveying roller pair 8 and 9 in the sheet conveying direction. The clip mechanism unit 90 can grip the leading end portion of the auxiliary sheet 70 that is fed together with the sheet S toward the nip portion of the pair of conveying rollers 8 and 9. Two clip mechanism portions 90 are installed so as to correspond to both end portions of the leading edge 75 of the auxiliary sheet 70. Referring to FIG. 8 for details of the structure, each clip mechanism 90 has two rotating members 90a and 90b that are pivotally supported by a hinge so as to be opened and closed. A plurality of pinch rollers 91a are rotatably disposed at a portion of one rotating member 90a opposite to the other rotating member 90b. A plurality of pinch rollers 91b that abut on the pinch rollers 91a are disposed in a portion of the other rotating member 90b that faces the one rotating member 90a. The pinch roller 91a is pressed against the pinch roller 91b facing each other by a spring (not shown), and a pinch pressure is generated between the pinch rollers 91a and 91b. The spring is attached to the hinge so as to bias the two rotating members 90a and 90b in the closing direction. The pinch rollers 91a and 91b have a so-called one-way mechanism that can be easily rotated in the direction of the black arrow in FIG. 8 but cannot rotate in the opposite direction of the black arrow. For this reason, in a state where the auxiliary sheet 70 is gripped between the pinch rollers 91a and 91b, a frictional force acts in the pulling direction of the auxiliary sheet 70 (the direction opposite to the white arrow), and the auxiliary sheet 70 is prevented from falling off due to its own weight. Has been.

Next, a flow when feeding using the auxiliary sheet 70 will be described with reference to FIGS. 6 and 7.
When the sheet S is fed together with the auxiliary sheet 70 from the sheet feeding unit 20 through the conveyance guide pair 22 by the user's hand, the leading edge of the sheet S in the sheet feeding direction comes into contact with the conveyance roller pairs 8 and 9. . As a result, the sheet S takes a posture perpendicular to the conveying roller pair 8 and 9.
When the sheet detection sensor 7 installed upstream of the conveying roller pair 8 and 9 detects the sheet S, the conveying roller pair 8 and 9 rotate by a predetermined amount (corresponding to about 5 mm) after a while. This state is shown in FIG. 7, and the leading end portion of the sheet S is sandwiched between the nip portions of the conveying roller pairs 8 and 9 by this rotational drive. At this time, the leading edge 75 of the auxiliary sheet 70 enters the clip mechanism 90 disposed slightly upstream from the pair of conveying rollers 8 and 9. Since the pinch rollers 91a and 91b are easily rotatable in the direction of the black arrow in FIG. 8, the auxiliary sheet 70 moved in the direction of the white arrow in FIG. It is guided to 92 and collides with the surface 92. As a result, the movement of the auxiliary sheet 70 in the direction of the white arrow in FIG. 8 (paper feeding direction) is restricted, and the leading edge 75 of the auxiliary sheet 70 does not reach the conveying roller 8. Therefore, the auxiliary sheet 70 is stopped on the upstream side of the conveyance roller 8 by the action of the clip mechanism 90 and remains in the sheet supply path, and only the sheet S moves downstream in the conveyance direction with the rotation driving of the conveyance roller 8. It will be conveyed. In order to remove the remaining auxiliary sheet 70 from the clip mechanism 90 after the printing is completed, the sheet conveying direction is increased with a force larger than the sum of the frictional force of the pinch rollers 91a and 91b and the pinch pressure acting between the pinch rollers 91a and 91b. Pull it upstream.

  According to such a 2nd Example, the same effect as a 1st Example can be acquired. That is, the sheet S can be fed by the auxiliary sheet 70 without causing a feeding failure. In addition, since only the sheet S is conveyed to the image forming unit, the negative pressure suction force on the sheet S is not hindered as in the conventional technique described above. Further, regarding the second embodiment, the auxiliary sheet 70 is not limited to being disposed on the printing surface side of the sheet S, and may be disposed on the surface opposite to the printing surface of the sheet S.

According to the first and second embodiments described above, the following operations and effects are achieved.
The auxiliary sheet 70 can be placed on the sheet S so that the side edges Sc and Sd and the rear edge Sb of the sheet S can be held by the tongue piece 72 and the notch 77 of the base sheet 71, respectively. When the auxiliary sheet 70 is thus attached by the user, the sheet S is not buckled by the rigidity of the base sheet 71 (FIGS. 2 and 3). Therefore, the user can reliably feed the leading edge of the sheet S to the nip portion of the pair of conveying rollers 8 and 9.
In addition, in the state where the auxiliary sheet 70 is attached to the sheet S as described above, the leading edge Sa of the sheet S in the sheet feeding direction is located outside the leading edge 75 of the auxiliary sheet 70. When the user supplies the auxiliary sheet 70 to which the sheet S is attached toward the nip portion of the conveyance roller pair 8, 9, the auxiliary sheet 70 is arranged so that the leading edge 75 of the auxiliary sheet 70 does not contact the conveyance roller 8. Is restricted by the restricting means. For this reason, only the sheet S is detached from the auxiliary sheet 70 and conveyed downstream as the conveyance roller 8 rotates. Therefore, negative pressure suction can be performed on the sheet S in a printer in which the platen 6 is provided with a negative pressure suction port in order to prevent the sheet S from floating in the image forming unit 3. The cut sheet conveying system of the present invention is configured by the image forming apparatus including the conveying roller pairs 8 and 9 and the regulating means, and the auxiliary sheet 70. The restricting means is a conveyance guide 80 of a magnetic material that attracts the magnet 76 of the auxiliary sheet 70 in the first embodiment, and is a clip mechanism 90 in the second embodiment.
The embodiment described above is an example of an image forming apparatus that forms an image on a sheet, but the present invention is not limited to this. The present invention can also be applied when a sheet is supplied in an apparatus that reads an original image formed on a sheet (original) with an image reading unit including a scanner.

S sheet 1 printer apparatus main body 3 image forming unit 8 conveying roller 9 pinch roller 70 auxiliary sheet 76 magnet 80 conveying guide (regulating means)
90 Clip mechanism (regulating means)

Claims (6)

A processing unit that performs processing on the sheet, a conveying unit that is arranged upstream of the processing unit in the sheet conveying direction, and that supports the sheet that is processed by the processing unit. A processing apparatus in which the sheet to be processed is attached to the auxiliary sheet such that the leading edge of the sheet to be processed in the transport direction is downstream of the leading edge of the auxiliary sheet,
A processing apparatus, further comprising: a regulating unit that regulates movement of the auxiliary sheet so that the leading edge of the auxiliary sheet does not reach the conveying unit after the leading edge of the sheet to be processed reaches the conveying unit. . The regulating means includes a conveyance guide made of a magnetic material disposed upstream of the conveyance means in the conveyance direction, and a magnet provided on the auxiliary sheet, and the magnet is attracted to the conveyance guide. The processing apparatus according to claim 1, wherein movement of the auxiliary sheet is restricted. The restricting means has a grip portion disposed upstream of the transport means in the transport direction, and movement of the auxiliary sheet is restricted when the auxiliary sheet is gripped by the grip portion. The processing apparatus according to claim 1. 4. The processing apparatus according to claim 1, further comprising a platen that is disposed downstream of the transport unit in the transport direction and sucks negatively a sheet on which the processing is performed. 5. The processing apparatus according to claim 1, wherein the processing unit is an image forming unit that forms an image on a sheet. The processing apparatus according to claim 1, wherein the processing unit is an image reading unit that reads an image on a sheet.

Images