KR100601892B1 - Paper transfering device for electrophotographic image forming apparatus - Google Patents

Abstract

The paper conveying apparatus of the image forming apparatus according to the present invention includes a counseling member and a transfer member which are provided to face each other to form a transfer section, a first guide member for guiding a print medium through the transfer section, and a first guide member. And a second guide member which is disposed between the transfer section and the print medium, which is spaced apart from a portion of the paper conveying path connecting the first guide member and the transfer section and is conveyed toward either the counseling member or the transfer member. Include. According to this, even if the size of the transfer member or counseling member is enlarged so that the distance between the first guide member and the transfer section increases, the quality of the print image is suppressed by suppressing the transfer of the print media to either the transfer member or the counseling member. The fall can be suppressed.

Image forming apparatus, consultation member, transfer member, first guide member, second guide member

Description

Paper transfering device for electrophotographic image forming apparatus

1 is a configuration diagram schematically showing a conventional image forming apparatus;

FIG. 2 is a cross-sectional view showing an extract of part A of FIG. 1;

3 is a cross-sectional view showing the main portion according to a preferred embodiment of the present invention;

4 is a cross-sectional view showing a state in which the transfer member of FIG. 3 is separated.

Explanation of symbols on the main parts of the drawings

100: image forming apparatus 110: image forming apparatus main body

160: counseling delay 170: transcription

191, 192: 1st guide member 191a, 192a: 1st guide surface

210: second guide member 213: second guide surface

215: rotating shaft 219: elastic body

230: frame 235: mounting groove

237: stopper

The present invention relates to an image forming apparatus, and more particularly, to a paper conveying apparatus of an electrophotographic image forming apparatus including a counseling member and a transfer member.

In general, electrophotographic image forming apparatuses such as copiers, facsimile machines, multifunction machines, and laser beam printers are for printing an image corresponding to input data using an electrophotographic process. To this end, the electrophotographic image forming apparatus includes a counseling member in which an image is formed on a surface by application of a developer, and a transfer member for charging the printing medium to transfer an image of the counseling member to a printing medium.

1 illustrates a conventional electrophotographic image forming apparatus. Referring to this, the conventional electrophotographic image forming apparatus 100 includes an intermediate transfer belt 160 provided as a counseling member and a transfer roller 170 provided as a transfer member.

The intermediate transfer belt 160 receives an image from the photosensitive drum 150. The image of the photosensitive drum 150 is from the developer supply device 130 along an electrostatic latent image formed on the surface of the photosensitive drum 150 by the light scanned from the laser scanning unit (LSU; Laser Scanning Unit; 140). It is formed by applying the supplied developer.

In the case of an image forming apparatus for printing a monochrome image, as described above, a photosensitive drum 150 or a photosensitive belt (not shown) in which an electrostatic latent image is formed is directly installed to face the transfer member, thereby performing a function of a counseling member. Is common. However, in the image forming apparatus 100 capable of printing a multicolor image as illustrated, the intermediate transfer belt 160 which receives the image from the photosensitive drum 150 is not easily printed using the photosensitive drum 150 alone. It is configured to perform the function of counseling delay.

Referring to FIG. 2, between the intermediate transfer belt 160 and the transfer roller 170, a transfer section T through the print medium is formed. Accordingly, the print medium transferred from the paper feeder 120 along the paper feed path P receives the image of the intermediate transfer belt 160 while passing through the transfer section T. FIG.

In order for the image to be uniformly printed on the print medium through the above-described process, the print medium must enter the transfer section T with a constant entry angle. For this purpose, the image forming apparatus 100 is used as a paper feeder. 120 further includes a plurality of guide members 191 and 192 having guide surfaces 191a and 192a for guiding the print medium supplied to the transfer section T with a predetermined entry angle.

On the other hand, in recent years, as the demand for an image forming apparatus having a high printing speed increases, in order to sufficiently transfer the image of the counselor to the print medium in a short time, the trend of expanding the transfer section T is increased. to be. The enlargement of the transfer section T can be achieved by enlarging the transfer surface 175 of the transfer roller 170, and thus, in recent years, the transfer roller 170 having a larger size for the enlargement of the transfer surface 175. ) Is a trend. The transfer roller 170 is generally configured to replace with a new one after using a certain time, according to the transfer section (T) so that the guide member 191, 192 does not interfere with the detachment of the transfer roller 170. It should be kept at a distance from the predetermined distance. Therefore, as the size of the transfer roller 170 increases, the distance between the guide members 191 and 192 and the transfer section T is gradually increased.

As described above, when the distance between the guide members 191 and 192 and the transfer section T increases, the print medium may move away from the normal paper feed path P to enter the transfer section T. It will be difficult to secure an entry angle. As shown in FIG. 2, when the guide surfaces 191a and 192a of the guide members 191 and 192 guide the print medium toward the transfer roller 170, the print medium is mounted with the transfer roller 170. Has a tendency to be transferred in the direction (P1) toward the inner side of the mounting groove 172 has been. In particular, when double-sided printing is performed in the image forming apparatus 100 as shown in FIG. 1, since the print medium which has already been heated once by the fixing unit 180 (see FIG. 1) enters the transfer section T again. As a result, the tendency to bend the print media is stronger, and the above-mentioned cases occur more frequently. In this case, not only the deterioration of the printed image quality but also a more serious obstacle such as a paper jam may occur.

The present invention has been made to solve the above-mentioned problems, and even if the distance between the guide member and the transfer section is increased by the size of the transfer member or the counseling member for the expansion of the transfer surface, it is possible to prevent the deterioration of the print image. It is an object of the present invention to provide a paper conveying apparatus for an image forming apparatus.

The paper conveying apparatus of the image forming apparatus according to the present invention for achieving the above object, the counseling member having an image formed on the surface; A transfer body installed to face the counseling member to form a transfer section between the counseling member and a transfer medium for transferring the image of the counseling member to a print medium via the transfer section; A first guide member installed upstream of the transfer section in a conveying direction of the print medium, the first guide member guiding the print medium to pass through the transfer section; And the printing medium is disposed between the first guide member and the transfer section, wherein the print medium is spaced apart from a portion of a paper transfer path connecting the first guide member and the transfer section. It characterized in that it comprises a; second guide member for suppressing the conveyance toward.

According to this, even if the size of the consultation member or the transfer member is enlarged and the distance between the first guide member and the transfer section is increased, the transfer of the print medium can be prevented from being bent. Therefore, the quality deterioration of a printed image can be suppressed.

According to a preferred embodiment of the present invention, the first guide member is disposed at a position spaced apart from the outer circumferential surface of the transfer member by a predetermined distance, and the second guide member is arranged on one side of the print medium to be in contact with the transfer member. It is provided with the guide surface to guide.

The extension line connecting the guide surface from one point of the paper feed path on the first guide member side may be inclined in a range within a predetermined inclination angle with respect to the paper feed path.

Meanwhile, the paper conveying apparatus of the image forming apparatus further includes a mounting groove formed inside the main body of the image forming apparatus and detachably accommodating the transfer member, wherein the second guide member is positioned adjacent to the mounting groove. It is preferable that a selective opening of a part of the mounting groove is installed in the contact hole, and the contact with the transfer member separated from the mounting groove is suppressed.

In addition, the second guide member is rotatably supported by a rotational shaft adjacent to the mounting groove, the paper conveying apparatus of the image forming apparatus, the elastic member for elastically biasing the second guide member toward the transfer body side; And a stopper for restraining rotation of the second guide member by the elastic member so as to maintain a constant distance between the second guide member and the transfer member.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. For reference, in describing the embodiments of the present invention, the same reference numerals as in the related art will be used for the components of the image forming apparatus having the same structure and function as those of the image forming apparatus shown and described with reference to FIGS. Quote by giving.

Referring to FIG. 3, a paper conveying apparatus of an electrophotographic image forming apparatus according to a preferred embodiment of the present invention includes a counseling member 160, a transfer member 170, a first guide member 191, 192, and The second guide member 210 is included. For reference, reference numeral 194 denotes a feed roller for transferring the print medium to the transfer section (T) to be described later.

The counseling member 160 has a predetermined image formed on the surface of the counseling member 160, and the image is transferred when the print medium is transferred via the transfer section T between the counseling member 160 and the transfer member 170. Transferred to the print media. In this embodiment, as the counseling member 160, an intermediate transfer belt formed in the shape of a belt is employed as described in the related art, but the shape of the counseling member 160 is formed by the image forming apparatus 100; According to the internal structure and the printing method of Figure 1) it may be formed in a variety of forms, such as formed in a drum shape as known photosensitive drum 150 (see Figure 1). For reference, reference numeral 165 denotes a roller that can constantly support the rotational drive of the consultation body 160 when the consultation body 160 is formed in a belt shape as in the present embodiment.

The transfer member 170 is for charging the print medium so that the image of the counselor 160 is transferred when the print medium passes through the transfer section T, and the transfer surface 175 facing the transfer section T. This is formed on the outer peripheral surface. The transfer member 170 may be formed in a roller shape or a belt shape to be rotatably installed in the image forming apparatus main body 110 (see FIG. 1), or may be formed in a pad shape to form the image forming apparatus main body 110. It can be formed in various forms, such as being fixedly installed inside. The transfer member 170 in this embodiment is formed in the form of a roller, and transfers the print medium to the fixing unit 180 (see FIG. 1) by interaction with the consultation body 160 during its rotational drive. Then, the transfer member 170 is detachably installed in the mounting groove 235 formed on one side of the frame 230 provided inside the image forming apparatus, and after a predetermined time of use is replaced as shown in FIG. Is made possible.

The first guide members 191 and 192 are for guiding the print medium to enter the transfer section T while having a predetermined entry angle. To this end, the first guide members 191 and 192 are installed upstream of the transfer section T along the paper transfer direction, and the first guide surface 191a guides the print medium to be transferred to the transfer section T. 192a. In this embodiment, the print media is guided to the transfer member 170 by the first guide surfaces 191a and 192a. The first guide members 191 and 192 are installed at a distance from an outer circumferential surface of the transfer member 170 installed in the mounting groove 235 so as not to prevent replacement of the transfer member 170.

As described above, as the first guide member 191 and 192 are spaced apart from the transfer member 170 by a predetermined distance, the second guide member 210 may include a printing groove 235 or a counseling member 160. It is for preventing the separation (P1; see Fig. 2) from the normal paper feed path (P) is conveyed toward the side. In this embodiment, the print medium is protruded to cover a part of the mounting groove 235 from the frame 230 so as to prevent the print medium from being transferred toward the mounting groove 235. Then, the first guide member 191, 192 is disposed on the paper transfer path (P) between the end of the transfer section (T) and the first contact with one side of the print medium to be in contact with the transfer member 170 2 includes a guide surface 213. The second guide surface 213 is formed to be inclined at a predetermined angle with respect to the second guide member 210 in correspondence with the paper feed path P. FIG. Here, the position of the second guide surface 213 does not necessarily have to be on the normal paper feed path P. FIG. That is, if the print medium can only be prevented from bending in the inward direction of the mounting groove 235, the print medium is installed in close proximity to the consultation body 160 in response to the internal structure of the image forming apparatus 100, or the print medium is bent. It is irrelevant that it may be installed close to the transfer member 170 so as not to contact unless it is transferred. In this case, an extension line connecting the second guide surface 213 from one point of the end side paper transfer path of the first guide members 191 and 192 starts from the end of the first guide members 191 and 192. A predetermined angle is inclined with respect to the normal paper feed path P. FIG. When the inclination angles θ1 and θ2 are formed too large, the print media may be transferred to the counseling member 160 or the transfer member 170 so that the developer may not be uniform in the amount of the printed image. (θ1, θ2) should be within a certain range. In the present embodiment, an extension line connecting the second guide surface 213 from one point of the end side paper transfer path of the first guide members 191 and 192 to the counsel member 160 from the normal paper feed path P. 4 °, the second guide surface 213 is preferably disposed so as not to be inclined by 10 ° or more toward the transfer member 170 side.

On the other hand, the second guide member 210 configured as described above should also not interfere with the replacement of the transfer member 170. To this end, the second guide member 210 should be installed to selectively open a part of the mounting groove 235. As shown in FIG. 4, the second guide member 210 according to the present exemplary embodiment is formed in a lever shape provided to be rotatable using the pivot shaft 215 provided on the frame 230 as the pivot center. Accordingly, when the transfer body 170 is separated from the mounting groove 235, the second guide member 210 is rotated to completely open the mounting groove 235, and the transfer body 170 in the mounting groove 235. In the installed state can be returned to the original position.

On the other hand, the rotation of the second guide member 210 as described above is preferably made elastically for the user's convenience. To this end, the paper transfer apparatus of the image forming apparatus according to the present embodiment is intended to be rotated by the elastic body 219 which elastically biases the second guide member 210 toward the transfer member 170, and the elastic body 219. The second guide member 210 includes a stopper 237 for supporting the second guide member 210 in contact with the transfer member 170 so as to maintain a predetermined distance from the transfer member 170. The elastic body 219, one end is fixed to the frame 230, the other end is fixed to the second guide member 210, installed so as to surround the rotation shaft 215 of the second guide member 210. And the torsion spring elastically biases the second guide member 210. Correspondingly, the stopper 237 is formed to protrude from one side of the frame 230. In this way, the complexity of the structure due to the installation of the stopper 237 can be avoided. Although not shown, the bias direction of the second guide member 210 by the elastic body 219 and the stopper 237 as described above may be interchanged, and in this case, the stopper 237 may be the second guide member. It may also function as a locking means that can selectively permit rotation of 210.

In the above description of the present invention, the second guide member 210 is limited to the case of guiding one side of the print medium to face the transfer member 170. However, the present invention is not limited only to such a case. Although not shown, if the print medium is guided by the first guide members 191 and 192 to bend toward the counseling member 160, the second guide member 210 is reversed in the present embodiment. The first guide member 191, 192 and the second guide member 213 may be configured in various forms, for example, in a shape of guiding the transfer member 170 toward the transfer member 170.

According to the present invention described above, the second guide member provided between the first guide member and the transfer section prevents the print medium from being excessively bent toward the transfer member, thereby degrading the quality of the printed image. It can prevent.

As a result, the transfer surface of the transfer member can be enlarged, and the quality of the image can be prevented from being degraded even at the time of high-speed printing using an electrophotographic process and printing of multicolor images.

In addition, since the second guide member is installed to elastically open a portion of the mounting groove of the transfer member, the transfer member can be easily replaced even when the second guide member is installed.

While the invention has been shown and described with respect to preferred embodiments for illustrating the principles of the invention, the invention is not limited to the construction and operation as shown and described. Rather, those skilled in the art will appreciate that various changes and modifications can be made to the present invention without departing from the spirit and scope of the appended claims. Accordingly, all such suitable changes, modifications, and equivalents should be considered to be within the scope of the present invention.

Claims (5)

A counseling member having an image formed on its surface; It is detachably mounted to the main body of the image forming apparatus, and is disposed to face the counseling member when mounted on the main body of the image forming apparatus to form a transfer section between the counseling member and the print medium via the transfer section. A transfer body for transferring an image of a counseling member; Installed upstream of the transfer section along the conveying direction of the print medium so as to be spaced apart from the transfer body by a distance that does not come into contact with the transfer body when moved in the direction of separation of the transfer body from the image forming apparatus main body; A first guide member for guiding one side of the print medium such that a medium is conveyed toward the transfer section; And A position disposed between the first guide member and the transfer section and in contact with a portion of the transfer member mounted on the image forming apparatus main body and in contact with the transfer member when the transfer member is moved for separation of the transfer member; And a second guide member which is rotatable between positions which are not. The print medium is guided by the first guide member and the second guide member sequentially guided to any one of the counseling member and the transfer member is suppressed that the transfer paper sheet of the electrophotographic image forming apparatus, characterized in that Conveying device. The method of claim 1, wherein the second guide member, And a guide surface for guiding the other side of the print medium to be in contact with the transfer member when the print medium enters the transfer section. The method of claim 2, Further comprising a paper conveyance path connecting the first guide member and the transfer section, An imaginary extension line extending from the guide surface and connected to the paper feed path may have an inclination angle between the extension line and the paper feed path within 4 ° toward the counseling member with respect to the paper feed path. Towards the paper conveying apparatus of the electrophotographic image forming apparatus, characterized in that formed to be inclined to be formed within 10 °. The method according to any one of claims 1 to 3, A mounting groove formed inside the main body of the image forming apparatus and detachably accommodating the transfer member; The second guide member is provided to be selectively opened to a part of the mounting groove in a position adjacent to the mounting groove, the contact with the transfer member separated from the mounting groove is suppressed Paper feed device of photographic image forming apparatus. The method of claim 4, wherein The second guide member is rotatably supported by a rotation shaft adjacent to the mounting groove, An elastic member for elastically biasing the second guide member toward the transfer member side, and a stopper for restraining rotation of the second guide member by the elastic member to maintain a constant distance between the second guide member and the transfer member; Paper transport apparatus of an electrophotographic image forming apparatus further comprising.

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