Paper guide mechanism and laser printer

Abstract

The utility model relates to a paper guiding mechanism which comprises a paper guiding piece which extends in a bending mode in the paper outlet direction, a plurality of paper guiding ribs are arranged on the paper guiding piece, an idler wheel which extends in the width direction is further arranged on the paper guiding piece in a rotating mode, and the outer surface of the idler wheel is higher than the paper guiding ribs. The paper guide mechanism can prevent paper from being in contact with the paper guide ribs, and prevent water drops condensed on the paper guide ribs from rotating to the paper. A laser printer comprises a rack, a fixing device and two supports which are oppositely arranged on the rack in parallel, the fixing device comprises a heating pipe and a pressure roller which are arranged in parallel, the heating pipe is arranged on one support, the pressure roller is arranged on the other support, a paper feeding channel for paper to pass through is formed between the two supports, and the laser printer further comprises the paper guiding mechanism. The paper guide mechanism is arranged on the rack, is in butt joint with the paper feeding channel and is arranged on the downstream of one support. According to the laser printer, abnormal development caused by dew formation and water drops is avoided, and the imaging stability of a printed image is guaranteed.

Description

Technical Field

[0001] The utility model relates to a paper guiding mechanism, and also relates to a laser printer applying the paper guiding mechanism. Background Art

[0002] The image fixing of a laser printer is to melt the toner transferred onto the paper by the heating tube and the pressure roller of the fixing device and then press it onto the paper. In this process, the temperature of the fixing device can reach up to about 200 degrees Celsius.

[0003] The double-sided paper output channel of a laser printer generally uses ribbed paper guiding. For example, in the Chinese invention patent application "Fixing Device" with the publication number CN117148698A (application number 202311138134.5), the disclosed fixing device includes a first bracket, a second bracket, a heating tube and a pressure roller. The first bracket and the second bracket are sequentially enclosed to form a paper feeding channel and a fixing cavity that communicate with each other; the heating tube and the pressure roller are both located in the fixing cavity, and one of the heating tube and the pressure roller is arranged on the first bracket, and the other is arranged on the second bracket. The first bracket is provided with a first paper guiding surface, the second bracket is provided with a second paper guiding surface opposite to the first paper guiding surface, and a third paper guiding surface opposite to the second paper guiding surface; a fourth paper guiding surface corresponding to the third paper guiding surface is provided on the printer main body. Paper guiding ribs are arranged on these paper guiding surfaces.

[0004] For this kind of paper guiding structure with paper guiding ribs, under special temperature and humidity conditions, especially in a high-temperature and high-humidity environment, when initially printing the first side of double-sided printing, the high-temperature working fixing device will evaporate the water vapor in the environment and the paper. The evaporated water vapor will reach a saturated state. Since the initial temperature of components such as the printer body is not high, the evaporated water vapor will condense on the surface of the relatively lower-temperature paper guiding ribs. As the water vapor continues to evaporate, the condensed water droplets will gradually become larger. During the printing process, the paper, especially the end of the paper, is likely to come into contact with the paper guiding ribs due to the relative sliding contact with the paper guiding structure, resulting in the water droplets on the paper guiding ribs being transferred to the back surface of the paper. After the water droplets moisten the paper, when printing the second side, the wetted part of the paper will contaminate the OPC surface, causing abnormal OPC development and affecting image formation. Summary of the Utility Model

[0005] The first technical problem to be solved by the utility model is to provide a paper guiding mechanism for a laser printer that can avoid the paper from contacting the paper guiding ribs and prevent the water droplets condensed on the paper guiding ribs from being transferred to the paper according to the above-mentioned prior art.

[0006] The second technical problem to be solved by the utility model is to provide a laser printer applying the aforementioned paper guiding mechanism according to the above-mentioned prior art.

[0007] The technical solution adopted by the utility model to solve the first technical problem mentioned above is: a paper guiding mechanism, which is arranged downstream of the fixer corresponding to the outlet position of the fixer, and includes a paper guiding member bent and extended along the paper output direction, and the paper guiding member has a plurality of paper guiding ribs. The paper guiding member is also rotatably provided with a roller extending along the width direction, and the outer surface of the roller is higher than the paper guiding ribs.

[0008] Preferably, at least two rollers are arranged on the paper guide at intervals along the width direction.

[0009] Preferably, the roller is arranged on the upstream side of the paper guide.

[0010] Preferably, the paper guide is provided with a plurality of paper guide ribs extending in the paper output direction at intervals along the width direction, and the roller is rotatably connected between two paper guide ribs.

[0011] Preferably, the height of the outer surface of the roller above the paper guide rib is h, 2mm≤h≤6mm.

[0012] The technical solution adopted by the utility model to solve the above-mentioned second technical problem is: a laser printer, including a frame, a fuser, and two brackets relatively parallel to each other on the frame, the fuser including a heating tube and a pressure roller arranged in parallel, the heating tube is arranged on one of the brackets, the pressure roller is arranged on the other bracket, a paper feeding channel for paper supply is formed between the two brackets, and also includes a paper guide mechanism as mentioned above, the paper guide mechanism is arranged on the frame and connected to the paper feeding channel and arranged downstream of one bracket.

[0013] Preferably, ribs for guiding paper are arranged on the opposite surfaces of the two brackets.

[0014] In order to ensure that the pressure roller and the heating tube maintain contact to achieve printing, a mounting plate is provided between the ends of the two brackets, and an elastic member is provided on the mounting plate. The elastic member presses against the end of the pressure roller to press the pressure roller toward the heating tube.

[0015] Compared with the prior art, the advantages of the present invention are as follows: the paper guide mechanism of the present invention, by arranging a roller higher than the paper guide rib on the paper guide, enables the paper to maintain rolling contact with the roller when the paper passes through the fuser and is output, and the paper can also transfer its own heat to the roller surface, so that the roller can maintain a relatively stable temperature, avoiding condensation on the roller. In addition, based on the structure that the roller is higher than the paper guide rib, it also avoids the contact between the paper and the paper guide rib, so that the condensation water droplets on the paper guide rib are attached to the paper, and accordingly avoids the influence on the subsequent reverse printing picture.

[0016] The laser printer applied with this paper guiding mechanism avoids the abnormal development caused by the condensed water droplets, and ensures the stability of the imaging of the printed image. Description of the Drawings

[0017] Figure 1 This is a perspective view of the paper guiding mechanism in the embodiment of the present utility model.

[0018] Figure 2 It is Figure 1 exploded view of. Detailed Embodiment

[0019] The following further describes the present utility model in detail with reference to the embodiments of the drawings.

[0020] As Figure 1 and Figure 2 shown, the paper guiding mechanism in this embodiment is arranged downstream of the fuser 1 corresponding to the outlet position of the fuser 1, and is used to realize the paper feeding guidance for the paper output by the fuser 1.

[0021] The paper guiding mechanism includes a paper guiding member 2 that bends and extends along the paper output direction. The paper guiding member 2 has a plurality of paper guiding ribs 21. Specifically, a plurality of paper guiding ribs 21 extending along the paper output direction are arranged at intervals in the width direction on the paper guiding member 2. When the paper moves to the position of the paper guiding member 2, the paper only contacts the tops of the paper guiding ribs 21. Usually, the upstream part of the paper guiding member 2 has been bent accordingly, and then the paper forms a paper feeding curvature and moves downstream. In this way, the contact between the paper and the downstream part of the paper guiding member 2 will be reduced accordingly. Also, because the contact area between the paper guiding ribs 21 and the paper is very effective, it is easy for the paper guiding ribs 21 to generate condensation in a high-temperature and high-humidity environment. Especially, the tail of the paper will fully contact the upstream part of the paper guiding member 2, resulting in the situation that the condensation water droplets on the paper guiding ribs 21 wet the paper at the tail of the paper. To solve this problem, in this embodiment, a roller 3 extending along the width direction is rotatably arranged on the paper guiding member 2. The outer surface of the roller 3 is higher than the paper guiding ribs 21, and the height of the outer surface of the roller 3 higher than the paper guiding ribs 21 is h, where 2 mm ≤ h ≤ 6 mm, and the specific value of h is determined according to the product design. The roller 3 is arranged on the upstream side of the paper guiding member 2. In this way, when the paper passes through the upstream of the paper guiding member 2, it realizes rolling contact with the roller 3. During the fusing process, since the roller 3 continuously contacts the paper, the high-temperature paper transfers heat to the surface of the roller 3, and the surface temperature of the roller 3 is relatively high and uniform, which is not conducive to the occurrence of condensation. Therefore, the situation that the water droplets on the roller 3 transfer to the back of the paper will not occur, avoiding the influence on the subsequent fusing image.

[0022] In this embodiment, at least two rollers 3 are arranged at intervals in the width direction on the paper guiding member 2, and the rollers 3 are rotatably connected between two paper guiding ribs 21.

[0023] The present utility model also relates to a laser printer applying the foregoing paper guiding mechanism. The laser printer specifically includes a frame 4, a fuser 1, two brackets 5 disposed relatively parallel on the frame 4, and the foregoing paper guiding mechanism. The fuser 1 includes a heating tube 11 and a pressure roller 12 disposed in parallel. The heating tube 11 is disposed on one of the brackets 5, and the pressure roller 12 is disposed on the other bracket 5. A paper feeding channel for the paper to pass through is formed between the two brackets 5. The paper guiding mechanism is disposed on the frame 4 and is disposed downstream of one bracket 5 in butt joint with the paper feeding channel. In order to effectively guide the paper and avoid the paper being adsorbed on the bracket 5, rib strips 51 for guiding the paper are provided on the opposite surfaces of the two brackets 5. The paper enters between the heating tube 11 and the pressure roller 12 through the paper feeding channel between the two brackets 5. During operation, the paper passes between the heating tube 11 and the pressure roller 12. Under the combined extrusion action of the heating tube 11 and the pressure roller 12 on the paper, and in cooperation with the heating operation, the image is fixed on the paper to achieve the fixing work.

[0024] In order to ensure that the pressure roller 12 and the heating tube 11 are kept in contact and pressed to achieve the fixing work, a mounting plate 6 is provided between the ends of the two brackets 5. An elastic member 7 is provided on the mounting plate 6. The elastic member 7 abuts against the end of the pressure roller 12 to elastically press the pressure roller 12 towards the heating tube 11. In this way, the elastic force of the elastic member 7 enables the pressure roller 12 to keep pressing against the heating tube 11, which is conducive to the cooperation of the two to achieve the fixing work.

[0025] In the paper guiding mechanism of the present utility model, by providing rollers 3 higher than the paper guiding ribs 21 on the paper guiding member 2, when the paper passes through the fuser 1 and is output, the paper keeps rolling contact with the rollers 3. The paper can also transfer its own heat to the surface of the rollers 3, so that the rollers 3 can maintain a relatively stable temperature, avoiding the condensation of the rollers 3. And based on the structure that the rollers 3 are higher than the paper guiding ribs 21, it also avoids the paper contacting the paper guiding ribs 21 and the condensed water droplets on the paper guiding ribs 21 sticking to the paper, correspondingly avoiding the influence on the subsequent reverse printing image.

[0026] The laser printer applying this paper guiding mechanism avoids the development abnormality caused by the condensed water droplets and ensures the stability of the printed image formation.

[0027] In the description and claims of the present utility model, terms indicating directions such as "front", "rear", "upper", "lower", "left", "right", "side", "top", "bottom", etc. are used to describe various exemplary structural parts and elements of the present invention. However, the use of these terms herein is only for the purpose of convenience in description and is determined based on the exemplary orientations shown in the drawings. Since the embodiments disclosed by the present invention can be arranged in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to the directions opposite to or consistent with the direction of gravity.

Claims

1. A paper guide mechanism, arranged downstream of a fuser (1) corresponding to an outlet position of the fuser (1), comprising a paper guide (2) extending along a paper discharge direction, the paper guide (2) having a plurality of paper guide ribs (21), characterized in that: A roller (3) extending in the width direction is also rotatably arranged on the paper guide (2), and the outer surface of the roller (3) is higher than the paper guide rib (21).

2. The paper guiding mechanism according to claim 1, characterized in that: At least two rollers (3) are arranged on the paper guide (2) in an interval arrangement along the width direction.

3. The paper guiding mechanism according to claim 1, characterized in that: The roller (3) is arranged on the upstream side of the paper guide (2).

4. The paper guiding mechanism according to any one of claims 1 to 3, characterized in that: The paper guide (2) is provided with a plurality of paper guide ribs (21) extending in the paper output direction at intervals along the width direction, and the roller (3) is rotatably connected between two paper guide ribs (21).

5. The paper guiding mechanism according to any one of claims 1 to 3, characterized in that: The height of the outer surface of the roller (3) above the paper guide rib (21) is h, 2mm≤h≤6mm.

6. A laser printer, comprising a frame (4), a fuser (1), and two supports (5) arranged relatively parallel to the frame (4), the fuser (1) comprising a heating tube (11) and a pressure roller (12) arranged in parallel, the heating tube (11) being arranged on one of the supports (5), the pressure roller (12) being arranged on the other support (5), and a paper feeding passage for paper supply passing therethrough being formed between the two supports (5), characterized in that: It also comprises a paper guiding mechanism as claimed in any one of claims 1 to 5, wherein the paper guiding mechanism is arranged on the frame (4) and is arranged downstream of a bracket (5) so as to be connected to the paper feeding channel.

7. The laser printer according to claim 6, characterized in that: Ribs (51) for guiding paper are arranged on the opposing surfaces of the two brackets (5).

8. The laser printer according to claim 6, characterized in that: A mounting plate (6) is provided between the ends of the two brackets (5), and an elastic member (7) is provided on the mounting plate (6). The elastic member (7) abuts against the end of the pressure roller (12) to thereby locally press the pressure roller (12) toward the heating tube (11).

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