JP7005299B2 - Sheet holding mechanism and image forming device - Google Patents

Description

The present invention relates to a sheet pressing mechanism and an image forming apparatus such as a copying machine, a multifunction device, a printer device, and a facsimile machine.

As an image forming apparatus, there is known one provided with a sheet pressing mechanism having a pressing member for pressing the sheet when the sheet such as paper is ejected toward the ejection tray (see Patent Document 1).

By the way, when the discharged sheet is placed on the discharge tray, if the tip of the sheet comes into contact with the upstream side (base end side) of the discharge tray, there is the following inconvenience. That is, the sheet is placed on the discharge tray while moving on the discharge tray with the tip of the sheet in contact with the upstream side of the discharge tray. At this time, if the tip of the sheet does not move smoothly on the discharge tray, for example, the sheet will be loaded on the discharge tray in a curved state with the tip facing down.

From this point of view, in the conventional image forming apparatus, the sheet is undulated in the width direction orthogonal to the ejection direction of the sheet, and the sheet is seated. By doing so, the tip of the sheet can be brought into contact with the downstream side (tip side) of the discharge tray. Therefore, for example, it is possible to effectively prevent the sheet from being loaded on the discharge tray in a state of being curved with the tip facing down.

However, when the discharged sheet comes into contact with the pressing member, the waist of the sheet may be broken (the wave of the sheet is broken) depending on the contact position with the pressing member of the sheet. Then, the tip of the sheet cannot be brought into contact with the downstream side of the discharge tray.

Japanese Unexamined Patent Publication No. 2014-47067

In this regard, Patent Document 1 does not show anything about the bending of the sheet when the discharged sheet comes into contact with the pressing member.

Therefore, according to the present invention, it is possible to suppress the bending of the sheet when the discharged sheet comes into contact with the holding member, whereby, for example, the sheet is loaded on the discharge tray in a curved state with the tip facing down. It is an object of the present invention to provide a sheet pressing mechanism and an image forming apparatus capable of effectively preventing such a situation.

In order to solve the above-mentioned problems, the sheet holding mechanism according to the present invention is provided when the sheet, which is undulated in the width direction orthogonal to the discharging direction of the sheet and is seated, is discharged toward the discharging tray. A sheet pressing mechanism having a pressing member for pressing a sheet, the pressing member has a first pressing area for pressing two portions sandwiching the apex portion of the mountain of the sheet when the discharged sheet comes into contact with the sheet. A pair of holding portions and a connecting portion having a second holding region that connects the tips of the pair of holding portions and holds the central region of the sheet in the width direction when the sheet comes into contact with the discharge tray. It is characterized by having . Further, the image forming apparatus according to the present invention is characterized by including the sheet pressing mechanism according to the present invention.

According to the present invention, it is possible to suppress the bending of the sheet when the discharged sheet comes into contact with the holding member, whereby the sheet is loaded on the discharge tray in a curved state with the tip facing down. It is possible to prevent it effectively.

It is the schematic sectional drawing which looked at the image forming apparatus which concerns on this embodiment from the front. It is sectional drawing which shows the sheet ejection apparatus part in an image forming apparatus. It is a perspective view which looked at the ejection side of the sheet ejection apparatus of an image forming apparatus from diagonally above. It is a top view which shows the holding member in the seat holding mechanism of a sheet discharging device. It is a side view which looked at the main part of the sheet ejection device in an image forming apparatus from the ejection side. It is a front view which shows the state when the tip of the sheet is discharged from the discharge outlet of a sheet discharge device, and is in contact with the first holding region of a holding member. It is a side view which looked at the state shown in FIG. 6 from the discharge direction of a sheet. It is a top view of the state shown in FIG. It is a front view which shows the state which the tip of the sheet has reached the 2nd holding area of a holding member. It is a side view which looked at the state shown in FIG. 9 from the discharge direction of a sheet. It is a top view of the state shown in FIG. It is a front view which shows the state when the tip of a sheet comes into contact with a discharge tray. It is a top view which shows the other example of a holding member. It is a top view which shows still another example of a holding member. It is a top view which shows still another example of a holding member.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In the following description, the same parts are designated by the same reference numerals. Their names and functions are the same. Therefore, the detailed description of them will not be repeated.

[Image forming device]
FIG. 1 is a schematic cross-sectional view of the image forming apparatus 100 according to the present embodiment as viewed from the front. In the figure, reference numeral X represents a left-right direction when viewed from the front, and reference numerals X1 and X2 represent a left side (one side) and a right side (the other side), respectively. The reference numeral Y represents the depth direction orthogonal to the left-right direction X, and the reference numerals Y1 and Y2 represent the front side (one side) and the back side (the other side), respectively. The reference numeral Z represents a vertical direction and a vertical direction. The image forming apparatus 100 according to the present embodiment is a monochrome image forming apparatus. The image forming apparatus 100 performs an image forming process according to the image data read by the image reading apparatus 200 or the image data transmitted from the outside. The image forming apparatus 100 may be a color image forming apparatus that forms multicolor and monochromatic images with respect to the sheet P such as paper.

The image forming apparatus 100 includes a document feeding apparatus 108 and an image forming apparatus main body 110. The image forming apparatus main body 110 is provided with an image forming unit 102 and a sheet conveying system 103.

The image forming unit 102 includes an exposure unit 1, a developing unit 2, a photoconductor drum 3 that acts as an electrostatic latent image carrier, a cleaning unit 4, a charging device 5, and a fixing unit 7. Further, the sheet transport system 103 includes a paper feed tray 81, a manual paper feed tray 82, a discharge roller 31, and a discharge tray 14.

An image reading device 200 for reading an image of the original G is provided on the upper part of the image forming device main body 110. The image reading device 200 includes a document mounting table 221 on which the document G is placed. Further, a document feeding device 108 is provided on the upper side of the document mounting table 221. In the image forming apparatus 100, the image of the document G read by the image reading apparatus 200 is sent to the image forming apparatus main body 110 as image data, and the image is recorded on the sheet P.

The image forming apparatus main body 110 is provided with a sheet transport path W1. The paper feed tray 81 or the manual paper feed tray 82 supplies the sheet P to the sheet transfer path W1. The sheet transport path W1 guides the sheet P to the discharge tray 14 via the transfer roller 10 and the fixing unit 7. The fixing unit 7 heats and fixes the toner image formed on the sheet P to the sheet P. In the vicinity of the sheet transfer path W1, pickup rollers 11a and 11b, transfer rollers 12a, resist rollers 13, transfer rollers 10, heat rollers 71 and pressure rollers 72 in the fixing unit 7, and discharge rollers 31 are arranged.

In the image forming apparatus 100, the sheet P supplied by the paper feed tray 81 or the manual paper feed tray 82 is conveyed to the resist roller 13. Next, the sheet P is conveyed to the transfer roller 10 by the resist roller 13 at the timing of matching the sheet P with the toner image on the photoconductor drum 3. The toner image on the photoconductor drum 3 is transferred onto the sheet P by the transfer roller 10. After that, the sheet P passes through the heat roller 71 and the pressure roller 72 in the fixing unit 7, passes through the transport roller 12a and the discharge roller 31, and is discharged onto the discharge tray 14. When the image is formed not only on the front surface of the sheet P but also on the back surface, the sheet P is conveyed in the reverse direction from the discharge roller 31 to the inverted sheet transfer path W2. The sheet P is guided to the resist roller 13 again by inverting the front and back of the sheet P via the inverting transfer rollers 12b to 12b. Then, the sheet P is discharged toward the discharge tray 14 after the toner image is formed and fixed on the back surface in the same manner as on the front surface.

[Sheet ejector]
FIG. 2 is a cross-sectional view showing a portion of the sheet ejection device 300 in the image forming apparatus 100. FIG. 3 is a perspective view of the discharge side of the sheet discharge device 300 in the image forming device 100 as viewed from diagonally above.

The image forming apparatus 100 further includes a sheet ejecting apparatus 300. The sheet discharging device 300 discharges the sheet P sent from the fixing unit 7 toward the discharging tray 14. The seat discharging device 300 includes a transport roller 12a, a discharging roller 31, a waist roller 32 (an example of a waist member), and a seat pressing mechanism 301.

The transfer roller 12a conveys the sheet P sent from the fixing unit 7 toward the discharge roller 31 and the waist roller 32. The discharge roller 31 discharges the sheet P sent from the transport roller 12a toward the discharge tray 14. The discharge roller 31 is composed of a pair of upper and lower discharge rollers 31a and 31b. The upper discharge roller 31a is smaller in size in the width direction H orthogonal to the discharge direction E of the sheet P than the lower discharge roller 31b. The upper discharge roller 31a faces the central portion of the lower discharge roller 31b in the width direction H. The upper discharge roller 31a is a drive roller, and the lower discharge roller 31b is a driven roller. The lower discharge roller 31b is urged toward the upper discharge roller 31a by an urging member (not shown) such as a spring. The waist roller 32 is arranged at both ends of the lower discharge roller 31b in the width direction H. The outer diameter of the waist rollers 32 to 32 is larger than the outer diameter of the lower discharge roller 31b. As a result, the waist roller 32 can cause the seat P to undulate in the width direction H so that the seat P can be seated.

The seat pressing mechanism 301 includes a pressing member 310. The pressing member 310 presses the sheet P when the sheet P seated by the waist roller 32 is discharged toward the discharge tray 14. As a result, the momentum of the sheet P discharged toward the discharge tray 14 can be relaxed by the holding member 310.

(First Embodiment)
FIG. 4 is a plan view showing a pressing member 310 in the seat pressing mechanism 301 of the seat discharging device 300. FIG. 5 is a side view of the main part of the sheet discharging device 300 in the image forming apparatus 100 as viewed from the discharging side. FIG. 6 is a front view showing a state when the tip P1 of the seat P is discharged from the discharge outlet 300a of the seat discharge device 300 and comes into contact with the first holding region α of the holding member 310. FIG. 7 is a side view of the state shown in FIG. 6 as viewed from the discharge direction E of the sheet P. FIG. 8 is a plan view of the state shown in FIG. In addition, in FIG. 8, the sitting state of the seat P seen from the discharge direction E is shown at the left end. This also applies to FIG. 11 described later.

FIG. 9 is a front view showing a state in which the tip P1 of the seat P reaches the second pressing region β of the pressing member 310. FIG. 10 is a side view of the state shown in FIG. 9 as viewed from the discharge direction E of the sheet P. FIG. 11 is a plan view of the state shown in FIG. Further, FIG. 12 is a front view showing a state when the tip P1 of the sheet P comes into contact with the discharge tray 14.

As shown in FIG. 8, the pressing member 310 has a first pressing region α. The first pressing region α presses a portion (in this example, a portion of the valley Pb) other than the apex portion Pc of the peak Pa of the sheet P when the discharged sheet P (tip P1) abuts. The first pressing region α extends from the contact position of the sheet P in the discharge direction E of the sheet P by a predetermined distance. Here, the apex portion Pc of the mountain Pa of the sheet P is in the width direction H including the apex Pt of the mountain Pa on the mountain Pa side with the boundary line L between the mountain Pa and the valley Pb of the sheet P as the boundary. Refers to a predetermined area. The apex portion Pc may be a region of the entire mountain Pa.

According to the present embodiment, the first pressing region α in the pressing member 310 presses a portion other than the apex portion Pc of the mountain Pa of the sheet P when the discharged sheet P comes into contact with the first pressing region α. Then, it is possible to suppress the crunching of the sheet P when the discharged sheet P (the tip P1 of the sheet P) comes into contact with the pressing member 310. Therefore, the tip P1 of the sheet P can be brought into contact with the downstream side (tip side from the central portion) of the discharge tray 14. Thereby, for example, it is possible to effectively prevent the sheet P from being loaded on the discharge tray 14 in a curved state with the tip P1 facing down.

By the way, when the pressing member 310 presses a portion of the sheet P other than the central region γ (see FIG. 11) in the width direction H when the sheet P comes into contact with the ejection tray 14, the sheet P loaded on the ejection tray 14 is aligned. Sex (stacking) deteriorates.

In this respect, in the present embodiment, the pressing member 310 has a second pressing region β. The second pressing region β presses the central region γ in the width direction H of the sheet P when the sheet P comes into contact with the discharge tray 14. By doing so, when the sheet P comes into contact with (places) the discharge tray 14, the second pressing region β of the pressing member 310 presses the central region γ in the width direction H of the sheet P. As a result, the consistency of the sheet P loaded on the discharge tray 14 can be improved. Here, the central region γ in the width direction H of the sheet P is a predetermined region including the center in the width direction H of the sheet P.

In the present embodiment, the first pressing region α presses two or more (two in this example) portions other than the apex Pc of the mountain Pa of the sheet P when the discharged sheet P comes into contact with the first pressing region α. By doing so, it is possible to suppress the crunching of the sheet P while stably discharging the sheet P.

In the present embodiment, the pressing member 310 has a pair of pressing portions 311, 311 (see FIG. 4). The pair of pressing portions 311, 311 presses two portions other than the apex portion Pc of the mountain Pa of the sheet P when the discharged sheets P come into contact with each other. The pair of pressing portions 311, 311 has a first pressing region α. By doing so, the pressing member 310 can reliably press two portions other than the apex portion Pc of the mountain Pa of the sheet P with the pair of pressing portions 311, 311 when the discharged sheet P comes into contact with the sheet P. As a result, it is possible to suppress the crunching of the sheet P while stably discharging the sheet P. Further, the pressing member 310 has a connecting portion 312 (see FIG. 4). The connecting portion 312 connects the tip portions of the pair of pressing portions 311, 311. By doing so, the pair of pressing portions 311, 311 can be operated integrally. As a result, the discharged sheet P can be stably brought into contact with the pressing member 310. In this example, the connecting portion 312 has a second pressing region β.

In the present embodiment, the pressing member 310 is formed in a substantially U-shape having a curved portion on the downstream side (tip side) when viewed from the vertical direction Z in the discharge direction E of the sheet P. By doing so, the pressing member 310 ensures that when the discharged sheet P comes into contact with the sheet P, two portions other than the apex portion Pc of the mountain Pa of the sheet P are reliably located on the upstream side (base end side) of the substantially U-shape. You can hold it down. As a result, it is possible to suppress the crunching of the sheet P while stably discharging the sheet P. Further, the pressing member 310 can press the center or the substantially center of the sheet P with a substantially U-shaped curved portion when the sheet P comes into contact with the discharge tray 14. As a result, the consistency of the sheet P loaded on the discharge tray 14 can be improved.

In the present embodiment, as shown in FIG. 4, the connecting portion 312 gradually extends in the width direction from the downstream end portion (tip portion) of the pair of holding portions 311, 311 to the downstream side in the discharge direction E of the sheet P. It is evenly or substantially evenly inclined inward in H. The connecting portion 312 is connected to the pair of pressing portions 311, 311 so as to be the apex at the central portion or the substantially central portion in the width direction H. Further, the pair of pressing portions 311, 311 has base portions 311a and 311a and inclined portions 311b and 311b. The base portions 311a and 311a are arranged in parallel or substantially parallel to the discharge direction E of the sheet P. The inclined portions 311b and 311b are provided between the base portions 311a and 311a and the connecting portion 312. The inclined portions 311b and 311b are gradually inclined inward in the width direction H from the base portions 311a and 311a to the connecting portion 312 at an inclination angle smaller than the inclination angle of the connecting portion 312, respectively. The pressing member 310 is integrally formed with a pair of pressing portions 311, 311 and a connecting portion 312. As a result, the pressing member 310 can be made into a single component.

In the present embodiment, the tip portion 312a of the connecting portion 312 is located at a position where the central portion or the substantially central portion of the seat P is pressed in the width direction H. By doing so, the sheets P loaded on the discharge tray 14 can be reliably aligned.

In the present embodiment, the pressing member 310 is configured to rotate around the axis Q along the width direction H. By doing so, the pressing member 310 can be smoothly rotated in the vertical direction Z. As a result, the discharged sheet P can be reliably brought into contact with the pressing member 310. Specifically, the engaging convex portions 310a and 310a (see FIGS. 4 and 6) project outward in the width direction H at the upstream end portion (base end portion) of the pressing member 310. Engaging holes 302a and 302a (see FIG. 6) penetrate the sheet discharging device main body 302 (exterior cover) (see FIG. 6) in the width direction H. The engaging hole portions 302a and 302a engage with the engaging convex portions 310a and 310a so as to be rotatable around the axis Q.

In the present embodiment, the discharge tray 14 (see FIGS. 2, 6, and 9) includes a first tray portion 141 and a second tray portion 142. The first tray portion 141 is located on the upstream side (base end side) of the discharge tray 14 in the discharge direction E of the sheet P. The second tray portion is continuously provided on the downstream side of the first tray portion 141. The first tray portion 141 and the second tray portion 142 are integrally formed. The first tray portion 141 is inclined so that the downstream side (tip side) is higher than the upstream side. The second tray portion 142 is inclined so that the horizontal or substantially horizontal or the downstream side is higher than the upstream side at an angle smaller than that of the first tray portion 141.

By the way, in the discharge tray 14, when the sheet P is crumbled, the sheet P is placed on the discharge tray 14 while moving on the first tray portion 141 with the tip P1 of the sheet P in contact with the first tray portion 141. Placed. At this time, if the tip P1 of the sheet P does not move smoothly on the first tray portion 141, for example, the sheet P will be loaded on the discharge tray 14 in a curved state with the tip P1 facing down. On the other hand, when the sheet P is not crumbled, the tip P1 of the sheet P can be brought into contact with the second tray portion 142. As a result, for example, the sheet P is not or hardly loaded on the discharge tray 14 in a curved state with the tip P1 facing down.

In this respect, in the present embodiment, the first holding region α in the holding member 310 when the sheet P comes into contact with the discharge tray 14 is the second tray portion in the discharging direction E of the sheet P, as shown in FIG. It extends to the corresponding area δ corresponding to 142. By doing so, it is possible to secure a state in which the portion of the sheet P other than the apex portion Pc of the mountain Pa is pressed by the first pressing region α up to the region δ corresponding to the second tray portion 142 when the sheet P is ejected. can. Therefore, the tip P1 of the sheet P can be brought into contact with the second tray portion 142. Then, the tip P1 of the sheet P can be smoothly moved by the second tray portion 142. Thereby, for example, it is possible to eliminate or almost eliminate the sheet P from being loaded on the discharge tray 14 in a curved state with the tip P1 facing down.

(Second Embodiment)
FIG. 13 is a plan view showing another example of the pressing member 310. In the pressing member 310 shown in FIG. 13, the connecting portion 312 is removed from the pressing member 310 according to the first embodiment, and the pair of pressing portions 311, 311 are formed in a straight line (rod shape) along the discharge direction E of the sheet P. It was done. The pair of pressing portions 311, 311 of the pressing member 310 shown in FIG. 13 has a first pressing region α. By doing so, it is possible to suppress the crunching of the sheet P while stably discharging the sheet P.

(Third Embodiment)
FIG. 14 is a plan view showing still another example of the pressing member 310. The pressing member 310 shown in FIG. 14 is provided with a connecting portion 312 in the pressing member 310 according to the second embodiment. The connecting portion 312 of the pressing member 310 shown in FIG. 14 is formed in a straight line at right angles or substantially at right angles to the pair of pressing portions 311, 311. By doing so, the pair of pressing portions 311, 311 can be operated integrally. As a result, the discharged sheet P can be stably brought into contact with the pressing member 310.

(Fourth Embodiment)
FIG. 15 is a plan view showing still another example of the pressing member 310. The pressing member 310 shown in FIG. 15 is the pressing member 310 according to the third embodiment, in which the protruding portion 312b is provided at the center of the connecting portion 312 in the width direction H. The protruding portion 312b of the pressing member 310 shown in FIG. 15 has a second pressing region β. The protruding portion 312b extends along the discharge direction E of the sheet P. By doing so, when the sheet P comes into contact with the discharge tray 14, the central region γ (see FIG. 11) in the width direction H of the sheet P can be pressed by the protruding portion 312b. As a result, the consistency of the sheet P loaded on the discharge tray 14 can be improved.

(Other embodiments)
In the present embodiment, the number of pressing portions of the pressing member is paired (two), but one or three or more may be used. Further, in the present embodiment, the waist member is a waist roller, but a waist guide may be used.

The present invention is not limited to the embodiments described above, and can be implemented in various other forms. Therefore, such embodiments are merely exemplary in all respects and should not be construed in a limited way. The scope of the present invention is set forth by the claims and is not bound by the text of the specification. Further, all modifications and modifications that fall within the equivalent scope of the claims are within the scope of the present invention.

100 Image forming device 14 Discharge tray 141 First tray part 142 Second tray part 300 Sheet discharge device 300a Discharge outlet 301 Seat presser mechanism 302 Sheet ejector main body 31 Discharge roller 310 Pressing member 311 Pressing part 311a Base part 311b Inclined part 312 Connecting part 312a Tip part 312b Protruding part 31a Upper discharge roller 31b Lower discharge roller 32 Sit roller (an example of a stool member)
E Discharge direction H Width direction L Boundary line P Sheet P1 Tip P2 Rear edge Pa Mountain Pb Valley Pc Vertex Pt Vertex Q Axis line α 1st presser area β 2nd presser area γ Central area δ Corresponding area

Claims (5)

A sheet pressing mechanism having a pressing member that presses the sheet when the sheet is undulated in a width direction orthogonal to the discharging direction of the sheet and is seated toward the discharging tray.
The pressing member includes a pair of pressing portions having a first pressing region for pressing two portions sandwiching the apex portion of the mountain when the discharged sheet comes into contact with each other, and a tip portion of the pair of pressing portions. A sheet pressing mechanism comprising a connecting portion having a second pressing region for pressing the central region of the sheet in the width direction when the sheet comes into contact with the discharge tray . The seat holding mechanism according to claim 1, wherein the seat holding mechanism is used.
The pressing member has a pair of bases arranged in parallel or substantially parallel to the sheet discharging direction forming the pair of pressing portions, and the inner side in the width direction toward the downstream side in the sheet discharging direction. It has a pair of inclined portions arranged so as to be inclined , and is characterized in that it is formed in a substantially U-shape with a curved portion on the downstream side when viewed from the vertical direction in the discharge direction of the sheet. Seat holding mechanism. The seat pressing mechanism according to claim 1 or 2 .
The seat holding mechanism is characterized in that the holding member is configured to rotate around an axis along the width direction. An image forming apparatus comprising the sheet pressing mechanism according to any one of claims 1 to 3 . The image forming apparatus according to claim 4 .
The discharge tray includes a first tray portion on the upstream side and a second tray portion connected to the downstream side of the first tray portion in the discharge direction of the sheet.
The first tray portion is inclined so that the downstream side is higher than the upstream side.
The second tray portion is inclined so that the horizontal or substantially horizontal or downstream side is higher than the upstream side at an angle smaller than that of the first tray portion.
An image forming apparatus characterized in that the first pressing region of the pressing member when the sheet comes into contact with the ejection tray extends to a region corresponding to the second tray portion in the ejection direction of the sheet. ..

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