JP2021080057A - Passing paper guide member, fixing unit and image formation apparatus - Google Patents

Abstract

To provide a passing paper guide member capable of preventing degradation in quality due to a contact of moisture generated due to dew condensation with a passing sheet of paper by satisfactorily retaining the moisture regardless of an arrangement attitude.SOLUTION: A passing paper guide member 400 includes: a passing paper guide rib part 401 for guiding passing paper and a passing paper guide rib support part 402 for supporting the passing paper guide rib part 401. The side face of the passing paper guide rib part 401 has a water-retention shape for water retention. As one example of the water-retention shape, there is a recessed part 404 constituted of a groove part extending from the side of guiding passing paper of the passing paper guide rib part 401 to the passing paper guide rib support part 402.SELECTED DRAWING: Figure 3

Description

The present invention relates to a paper passing guide member provided in the vicinity of a fixing device in an image forming apparatus such as a copying machine, a printer, and a facsimile, and other paper transport paths, a fixing unit provided with the paper passing guide member, and an image forming apparatus.

The image forming apparatus as described above includes a paper passing guide member that guides the passing paper to the paper transport path and other paper transport paths in the vicinity of the fixing device. As such a paper passing guide member, there is a structure in which a plurality of paper passing guide rib portions are supported in an upright state on the paper passing guide rib supporting portion. The paper passing guide member is arranged so that the tip of the paper passing guide rib portion faces the paper conveying path, and the conveyed paper is guided by the paper passing guide rib portion.

By the way, in the image forming apparatus, when printing is performed immediately after warming up from a low temperature state such as turning off the power, the moisture contained in the paper becomes water vapor due to the heating when the paper passes through the fixing nip of the fixing device. When water vapor touches an unheated paper guide member, it may condense and become water droplets. In addition, if the moisture comes into contact with the paper being passed through, the quality will deteriorate.

As one of the means for preventing this, Patent Document 1 proposes a method of retaining the moisture due to dew condensation generated on the paper-passing surface side by a hole provided at the root of the paper-passing guide rib.

Japanese Unexamined Patent Publication No. 2012-168224

However, in the method of Patent Document 1, when the paper-passing guide rib portion is arranged in a downward posture, the hole provided at the base of the paper-passing guide rib portion is located above the side surface of the paper-passing guide rib portion, which is caused by dew condensation. There is a problem that the water cannot be retained.

The present invention has been made to solve such a problem, and regardless of the arrangement posture, the moisture generated by dew condensation is satisfactorily retained, and the quality due to the moisture coming into contact with the paper being passed through the paper. It is an object of the present invention to provide a paper passing guide member capable of preventing deterioration of the paper passing guide member, and further to provide a fixing unit and an image forming apparatus provided with the paper passing guide member.

The above object is achieved by the following means.
(1) A paper-passing guide rib portion that guides paper-passing and a paper-passing guide rib support portion that supports the paper-passing guide rib portion are provided, and the side surface of the paper-passing guide rib portion has a water-retaining shape for water retention. Paper guide member.
(2) As the water-retaining shape, a groove extending from the side of the paper-passing guide rib portion for guiding the paper to the paper-passing guide rib support portion is formed, and the surface of the groove portion has a contact angle with water smaller than 90 degrees. The paper passing guide member according to item 1 above.
(3) The paper passing guide rib support portion has a hole portion penetrating the first surface on the side where the guide rib portion is supported and the second surface on the back side thereof at a position corresponding to the groove portion. The paper passing guide member according to item 2 above, wherein the paper guide member is formed.
(4) The paper passing guide member according to item (3) above, wherein a water absorbing means is arranged on the second surface side of the paper passing guide member so as to be in contact with the hole portion.
(5) When the paper-passing guide member is mounted on the paper transport path, the first surface of the paper-passing guide rib support portion is located higher than the edge of the hole on the first surface side. The paper passing guide member according to the preceding item 3 or the preceding item 4.
(6) The paper passing guide member according to any one of the preceding items 1 to 5, wherein a water repellent treatment is applied from a portion of the paper passing guide rib portion where the paper contacts to a portion where the groove portion starts.
(7) The feature is that the fixing portion and the paper passing guide member according to any one of the preceding items 1 to 6 arranged on at least one side of the fixing portion on the upstream side or the downstream side in the paper passing direction are provided. Fixing unit.
(8) The paper passing guide according to any one of the preceding items 1 to 6 arranged in the image forming section, the paper conveying path for conveying the paper from the upstream side to the downstream side of the image forming section, and the paper conveying path. An image forming apparatus including a member.

According to the invention described in the preceding paragraph (1), the paper-passing guide member includes a paper-passing guide rib portion that guides the paper-passing and a paper-passing guide rib support portion that supports the paper-passing guide rib portion, and has a side surface of the paper-passing guide rib portion. Has a water-retaining shape for water retention, so dew condensation occurs on the paper-passing guide ribs even when the paper-passing guide ribs are arranged in an upward or sideways position or even when the paper-passing guide ribs are arranged in a downward position. Water is retained by the water retention shape portion. Therefore, it is possible to effectively prevent the dew condensation water from dripping from the side of the paper passing guide rib portion that guides the paper passing and coming into contact with the paper being passed, and it is possible to prevent deterioration of the quality of the paper. ..

According to the invention described in the preceding paragraph (2), as a water-retaining shape, a groove portion extending from the side of the paper-passing guide rib portion for guiding the paper to the paper-passing guide rib support portion is formed, and water generated by dew condensation is formed in this groove portion. In addition to being retained, the surface of the groove has a contact angle with water smaller than 90 degrees, so that the water retention effect of the groove can be increased.

According to the invention described in the preceding paragraph (3), the paper passing guide rib support portion has a first surface on which the guide rib is supported and a second surface on the back side thereof at a position corresponding to the groove portion. Since the penetrating hole is formed, the groove and the hole can exert a synergistic water retention effect.

According to the invention described in the preceding paragraph (4), since the water absorbing means is arranged on the second surface side of the paper passing guide member so as to be in contact with the hole portion, the water retention of the hole portion can be further enhanced. it can.

According to the invention described in the preceding paragraph (5), the first surface of the paper passing guide rib support portion is higher than the edge of the hole portion on the first surface side when the paper passing guide member is mounted on the paper transport path. Since it is in the position, even if water droplets adhere to the first surface, the adhered water droplets flow to the hole portion along the first surface and are retained in the hole portion. Therefore, contact between water and the paper can be further prevented.

According to the invention described in the preceding paragraph (6), since the water-repellent treatment is applied from the portion of the paper-passing guide rib portion where the paper contacts to the portion where the groove portion starts, the paper-passing guide rib portion is arranged in a downward posture. However, it is possible to prevent the water accumulated in the groove portion from flowing from the portion where the groove of the paper passing guide rib portion starts to the portion where the paper comes into contact.

According to the invention described in the preceding paragraph (7), a paper passing guide having the effect according to any one of the preceding paragraphs (1) to (6) on at least one of the upstream side and the downstream side of the fixing portion in the paper passing direction. A fixing unit in which members are arranged can be provided.

According to the invention described in the preceding paragraph (8), the paper transport path for transporting the paper from the upstream side to the downstream side of the image forming portion and the paper transport path arranged in the paper transport path according to the preceding paragraphs (1) to (6). It is possible to provide an image forming apparatus including a paper passing guide member having the effect described in any one of them.

It is a figure which shows the schematic structure of the main part of the image forming apparatus which concerns on one Embodiment of this invention. It is a side view when the paper-passing guide member arranged with the paper-passing guide rib portion facing downward is seen from the upstream side in the paper-passing direction. (A) is a front view of the paper passing guide member of FIG. 2, and (B) is a view of the same paper passing guide member as viewed from below. It is a figure which shows the other embodiment of the paper-passing guide member, (A) is the figure which looked at the cross section of the line AA of FIG. It is a figure. It is a figure which shows the still another embodiment of the paper-passing guide member, and is the side view when the paper-passing guide member arranged with the paper-passing guide rib part facing down, is seen from the upstream side in the paper-passing direction. It is sectional drawing corresponding to FIG. 3A about the paper passing guide member of FIG. It is a figure which shows still another Embodiment of a paper-passing guide member, and is the front view of the paper-passing guide member. It is a figure which shows still another Embodiment of a paper-passing guide member, and is the figure which enlarges and shows the cross section of the paper-passing guide member when viewed from the upstream side in the paper-passing direction.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of a main part of an image forming apparatus 1 according to an embodiment of the present invention.

The image forming apparatus 1 has an image forming unit 110 that forms a toner image and transfers it to paper, and a paper conveying unit that conveys paper fed from a paper feeding unit (not shown) to a paper discharging unit 120 through the image forming unit 110. The fixing unit 100 and the fixing unit 100, which are arranged on the downstream side of the road 300 and the image forming unit 110, fix the toner image transferred to the paper by the image forming unit 110, and convey the paper further downstream after fixing. It is provided with a pair of paper ejection rollers 201 and 202 for ejecting the paper ejected from the paper to the paper ejection unit 120.

Further, the fixing unit 100 includes a fixing portion 130 for fixing the toner image transferred to the paper, and two paper passing guide members arranged vertically on the downstream side of the fixing portion 130 with a horizontal paper transport path interposed therebetween. It has 400 and 500.

Since the configurations of the image forming unit 110 and the fixing unit 130 are well known, detailed description thereof will be omitted, but in this embodiment, a fixing unit 130 including a heating roller 131 and a pressure roller 132 is used. ing.
[Embodiment 1]
2A and 2B are side views of the upper paper-passing guide member 400 when viewed from the upstream side in the paper-passing direction, FIG. 3A is a front view of the paper-passing guide member 400, and FIG. 3B is a paper-passing guide member. It is the figure which looked at 400 from the bottom.

The paper passing guide member 400 is for guiding the paper conveyed from the fixing portion 130, and as shown in FIG. 2, a plurality of paper passing guide rib portions 401 and one square plate-shaped one. The paper passing guide rib support portion 402 is provided. Each paper-passing guide rib portion 401 extends in the paper transport direction on one side in the thickness direction of the paper-passing guide rib support portion 402 and projects in a direction away from the paper-passing guide rib support portion 402. A plurality of papers are erected in a direction orthogonal to the paper transport direction of. Further, as shown in FIGS. 3A and 3B, the length of each paper-passing guide rib portion 401 in the paper transport direction is shorter than the width of the paper-passing guide rib support portion 402 in the paper-carrying direction, and the paper-passing guide rib support Both ends of the paper passing guide rib portion 401 in the length direction are located inward from both ends of the paper transport direction of the portion 402.

The configuration of the lower paper passing guide member 500 is also the same as the configuration of the paper passing guide member 400 except that the orientation is different. Also in the embodiments described below, the paper passing guide members 400 and 500 configurations are the same.

The two paper-passing guide members 400 and 500 having the above-described configuration are arranged so that the tip side of each paper-passing guide rib portion 401 faces the paper transport path 300, respectively, and horizontal paper transport is performed on the downstream side of the fixing portion 130. They are arranged vertically across the road 300. In this arrangement state, the paper passing guide rib support portion 402 extends in a direction in which the length direction thereof is orthogonal to the paper conveying direction (also referred to as the paper passing direction), and a plurality of paper passing guide rib portions 401 extend along the paper passing direction. It is in a state of being. The paper on which the toner image is fixed by the fixing portion 130 is conveyed to the paper discharging portion 120 through the paper conveying path 300 while being guided by the tips of the paper passing guide rib portions 401 of the upper and lower paper passing guide members 400 and 500. ..

On both side surfaces in the thickness direction of each paper guide rib portion 401, a plurality of rectangular ridges 403 extending from the paper guide rib support portion 402 to the vicinity of the tip of the paper guide rib portion 401 are formed on the paper guide rib portion 401. It is provided at equal intervals in the length direction (the width direction of the paper passing guide rib support portion 402). Therefore, recesses 404 formed of grooves are formed between the adjacent ridges 403, and the recesses 404 are formed at equal intervals in the length direction of the paper guide rib portions 401. These recesses 404 retain water generated by dew condensation or the like on the surfaces of the paper passing guide rib portion 401 and the paper passing guide rib support portion 402 to prevent water from coming into contact with the paper passing through the paper transport path 300. Has the function of

That is, when printing is performed immediately after warming up from a low temperature state such as when the power is turned off, the moisture contained in the paper becomes water vapor due to the heating when the paper passes through the fixing portion 130, and the water vapor is not warmed. When the paper guide members 400 and 500 are touched, dew condensation may occur and water droplets may be formed. In particular, in the paper-passing guide member 400 in which the tip of the paper-passing guide rib portion 401 is arranged downward above the paper transport path 300, the generated water droplets may flow down along the side surface of the paper-passing guide rib portion 401. However, since the recess 404 formed of the groove is formed, the water that has entered the recess 404 is retained in the recess 404 by the capillary phenomenon, and as a result, the contact with the paper due to the downward flow is prevented. Further, also in the paper passing guide member 500 in which the tip of the paper passing guide rib portion 401 is arranged downward of the paper transport path 300 with the tip of the paper passing guide rib portion 401 facing upward, water generated by dew condensation is retained in the recess 404 and prevented from flowing downward. To.

The recess 404 may have a groove shape other than the groove shape, but a groove shape is desirable assuming mold molding using a resin material. Further, since the water retention function uses the capillary phenomenon of water, the width of the recess 404 is preferably as small as possible, but it is preferably about 2 mm from the viewpoint of ease of molding. Further, the width of the ridge 403 forming the recess 404 is preferably as small as possible, but it is preferably about 1 mm from the viewpoint of ease of molding.

Further, since the water retention function uses the capillary phenomenon of water, it is good whether at least the surface of the recess 404 has hydrophilicity. Specifically, it is preferable that the contact angle with water is smaller than 90 degrees. As an example of a method for making the surface of the recess 404 hydrophilic, the paper passing guide rib portion 401 or further the ridge 403 is formed of a hydrophilic material, or at least the surface of the recess 404 is subjected to hydrophilic plating or coating. The method of doing, etc. can be mentioned.
[Embodiment 2]
Other embodiments of the paper passing guide members 400 and 500 will be described with reference to FIGS. 4A and 4B. 4 (A) is a view of the cross section of the line AA of FIG. 4 (B) viewed from the direction of the arrow, and FIG. 4 (B) is a view of the paper passing guide member 400 viewed from below.

In this embodiment, the configurations of the paper guide rib portion 401, the paper guide rib support portion 402, the ridge 403, and the recess 404 are the same as those in the first embodiment, but as shown in FIGS. At a position corresponding to the recess 404, a hole 405 that penetrates the paper passing guide rib support portion 402 in the thickness direction and communicates with the recess 404 is formed.

Further, as in the first embodiment, it is preferable that at least the surface of the recess 404 is hydrophilic and the inner surface of the hole 405 is also hydrophilic. Specifically, it is preferable that the contact angle with water is smaller than 90 degrees. As an example of the method for making the surface of the hole 405 hydrophilic, the paper passing guide rib support portion 402 is formed of a hydrophilic material, the surface of the hole 405 is hydrophilically plated or coated, and the like. The method can be mentioned.

In the second embodiment, since the hole 405 communicating with the recess 404 is formed, more water can be retained than the paper passing guide members 400 and 500 of the first embodiment.
[Embodiment 3]
Other embodiments of the paper passing guide members 400, 500 will be described with reference to FIGS. 5 and 6. FIG. 5 is a side view of the upper paper passing guide member 400 when viewed from the upstream side in the paper passing direction, and FIG. 6 is a cross-sectional view corresponding to FIG. 3 (A).

In this embodiment, in addition to the configuration of the paper-passing guide member 400 of the second embodiment shown in FIGS. 4A and 4B, the surface of the paper-passing guide rib support portion 402 opposite to the paper-passing guide rib portion 401. The water absorbing member 600 is arranged so as to be in contact with the hole 405. The water absorbing member 600 is made of a hygroscopic sponge-like material or a felt-like material.

By providing such a water absorbing member 600, the water generated by dew condensation on the surface of the paper passing guide rib portion 401 passes through the recess 404 and the hole 405 and is retained by the water absorbing member 600. It can retain more water than the paper guide members 400 and 500.
[Embodiment 4]
In this embodiment, as shown in FIG. 7, at least the contact portion 406 of the paper passing guide rib portion 401 that comes into contact with the paper is subjected to a water repellent treatment. Specifically, as shown by the dotted line in FIG. 7, the water repellent treatment is applied from the tip and the tip of the paper passing guide rib portion 401 in contact with the paper to the start portion of the recess 404. Since the other configurations of the paper passing guide member 400 are the same as those of the paper passing guide members 400 of the first to third embodiments, detailed description thereof will be omitted.

In this embodiment, since it is difficult for water to move to the water-repellent treated portion, the water retention capacity of the recess 404 can be improved, and the contact between the paper and water can be further prevented.
[Embodiment 5]
In this embodiment, the hole portion that penetrates the paper passage guide member 400 of the second embodiment shown in FIGS. 4A and 4B, that is, the paper passage guide rib support portion 402 in the thickness direction and communicates with the groove-shaped recess 404. The paper passing guide member 400 on which the 405 is formed is used. Then, on the same side surface of the paper passing guide rib support portion 402 as the paper passing guide rib portion 401, as shown in FIG. 8, from the intermediate portion between the adjacent paper passing guide ribs 401 and 401 toward the holes 405 and 405 on both sides. Therefore, a downhill inclined surface 407 is formed. Therefore, in the arranged state of the paper passing guide member 400, the inclined surface 407 between the adjacent paper passing guide ribs 401 and 401 of the paper passing guide rib supporting portion 402 is located at a position higher than the lower end edge of the hole portion 405. As a result, the moisture generated by dew condensation on the lower surface of the paper passing guide rib support portion 402 moves to the hole portion 405 along the inclined surface 407 by its own weight as shown by the arrow in FIG. 8, and is retained in the hole portion 405. .. In this case, the surface of the paper-passing guide rib support portion 402, which generates moisture due to dew condensation, is treated with hydrophilicity to prevent the moisture from becoming balls and to drip the moisture before it reaches the hole 405. It is desirable from the viewpoint that it can be prevented.

A groove may be formed on the inclined surface 407 of the paper passing guide rib support portion 402 toward the hole portion 404 along the inclined direction. Further, the water absorbing member 600 may be arranged on the surface of the paper passing guide rib support portion 402 opposite to the paper passing guide rib portion 401 so as to be in contact with the hole portion 405.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, although the paper passing guide members 400 and 500 are arranged on the downstream side of the fixing portion 130, they may be arranged on the upstream side of the fixing portion 130 and may be arranged at any position of the paper transport path 300.

Further, although recesses 404 formed of grooves are formed on both side surfaces of the paper guide rib portion 401 as a water-retaining shape, recesses 404 may be formed only on one side surface of the paper guide rib portion 401.

1 Image forming device 100 Fixing unit 110 Image forming part 120 Paper ejection part 130 Fixing part 131 Heating roller 132 Pressurized roller 300 Paper transport path 400, 500 Paper passing guide member 401 Paper passing guide rib part 402 Paper passing guide rib support part 403 Protrusion 404 Recess 405 Hole 406 Contact with paper 407 Inclined surface 600 Water absorbing member

Claims (8)

The paper passage guide rib part that guides the paper passage and
A paper passing guide rib supporting portion for supporting the paper passing guide rib portion is provided.
A paper-passing guide member characterized in that the side surface of the paper-passing guide rib portion has a water-retaining shape for water retention. As the water-retaining shape, a groove portion extending from the side of the paper-passing guide rib portion for guiding the paper to the paper-passing guide rib support portion is formed.
The paper passing guide member according to claim 1, wherein the surface of the groove has a contact angle with water smaller than 90 degrees. The paper passing guide rib support portion is formed with a first surface on the side where the guide rib portion is supported and a hole portion penetrating the second surface on the back side thereof at a position corresponding to the groove portion. The paper passing guide member according to claim 2, wherein the paper passing guide member is provided. The paper passing guide member according to claim 3, wherein a water absorbing means is arranged on the second surface side of the paper passing guide member so as to be in contact with the hole portion. A claim characterized in that, in a state in which the paper passing guide member is mounted on a paper transport path, the first surface of the paper passing guide rib support portion is located higher than the edge of the hole portion on the first surface side. The paper passing guide member according to claim 3 or 4. The paper passing guide member according to any one of claims 1 to 5, wherein a water repellent treatment is applied from a portion of the paper passing guide rib portion where the paper contacts to a portion where the groove portion starts. The feature is that the fixing portion and the paper passing guide member according to any one of claims 1 to 6 arranged on at least one side of the fixing portion on the upstream side or the downstream side in the paper passing direction are provided. Fixing unit. The paper passing guide member according to any one of claims 1 to 6, which is an image forming portion, a paper transport path for transporting paper from the upstream side to the downstream side of the image forming section, and a paper transport path arranged in the paper transport path. An image forming apparatus characterized by being provided with.

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