Patent Application
20140035219
This application claims priority to Japanese Patent Application No. 2012-173606 filed on 6, Aug., 2012 the entire contents of which are incorporated by reference herein.
The present disclosure relates to a sheet conveying apparatus and an image forming apparatus including the same.
In an image forming apparatus for forming an image on a sheet, a toner image is formed on a photosensitive drum of an image forming section, and the toner image is transferred onto the sheet in a transfer nip portion. The image forming apparatus further includes a fixing section, and the sheet onto which the toner image has been transferred is subjected to a fixing process in the fixing section and then discharged.
The image forming apparatus as described above includes a paper feed device disposed to feed sheets to the transfer nip portion. The paper feed device includes a sheet cassette and a manual feed tray. In addition, a first sheet conveying path extending from the sheet cassette and a second sheet conveying path extending from the manual feed tray are joined in a conveying path joining section before reaching the transfer nip portion. Therefore, in order to selectively communicate any one of the first and second conveying paths with the transfer nip portion, a swingable switching guide member is disposed in the conveying path joining section.
Further, there is an image forming apparatus including an elongated shaped switching guide member, as seen from a cross-section in a direction orthogonal to a sheet conveying direction. In this image forming apparatus, as an upper end side of the switching guide member pivots around a supporting point disposed at a lower end part of the switching guide member, the sheet conveying path is switched.
As an aspect of the present disclosure, technology for further improving the above-described related art is proposed.
A sheet conveying apparatus in accordance of an aspect of the present disclosure includes a casing, a first conveying path, a second conveying path, a junction portion, a joining conveyance path, and a guide member.
The first conveying path is disposed in the casing to convey a first sheet.
The second conveying path is disposed in the casing to convey a second sheet, and joined with the first conveying path.
The junction portion is a portion in which the first conveying path and the second conveying path are joined.
The joining conveyance path is connected to a junction portion of the first conveying path and the second conveying path, and extends downstream in a sheet conveying direction on the first conveying path and the second conveying path.
The guide member is disposed in the junction portion, and configured to shift a position between a first position to guide the first sheet from the first conveying path to the joining conveyance path and a second position to guide the second sheet from the second conveying path to the joining conveyance path.
In addition, the guide member is formed in an elongated shape as seen from a cross-section orthogonal to a sheet width direction of each sheet, and has a supporting point portion disposed at a central part or a vicinity thereof in a lengthwise direction of the elongated shape, so as to shift the position by pivoting around the supporting point portion.
Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.
The image forming apparatus 1 includes a substantially rectangular main casing 2. The main casing 2 includes a substantially rectangular lower casing 21 (a casing), a substantially rectangular upper casing 22 arranged above the lower casing 21, and a connecting casing 23 configured to connect the lower casing 21 and the upper casing 22. The connecting casing 23 extends along a right edge and a back surface edge of the main casing 2. A sheet S subjected to a print process is discharged to a discharge space 24 surrounded by the lower casing 21, the upper casing 22, and the connecting casing 23. In particular, in this embodiment, the sheet S is discharged to a paper ejection section 241 disposed on an upper surface part of the lower casing 21, and to a paper ejection tray 242 (
An operation section 221 disposed in a front direction of the upper casing 22, for example, includes an LCD touch panel 222. The operation section 221 is formed to enable information on image forming processes to be input. A user can input, for example, the number of sheets to be printed, the print intensity, or the like through the LCD touch panel 222. The upper casing 22 mainly includes a device for reading an image from a manuscript, and an electronic circuit for executing overall control of the image forming apparatus 1 housed therein.
A pressing cover 223 arranged on the upper casing 22 is used to press against the manuscript. A rear side of the pressing cover 223 is pivotably attached to the upper casing 22. A front side of the pressing cover 223 can pivot vertically. The user loads the manuscript on the upper casing 22 by pivoting the pressing cover 223 upward. Thereafter, the user operates the operation section 221 to cause the device arranged in the upper casing 22 to read an image from the manuscript.
A manual feed tray 240 is arranged on a right side surface of the lower casing 21. The manual feed tray 240 is configured such that an upper end 240B side thereof can pivot vertically with a lower end 240A thereof (
The image forming apparatus 1 includes a paper feed device 10, a pair of registration rollers 116, and an image forming section 120. The paper feed device 10 includes a cassette 110 (a sheet loading section), a paper feed section 11, a second paper feed roller 114, and a conveyance junction section 101 (junction portion).
The cassette 110 is configured to house a sheet S (a sheet S1, which is a first sheet). The cassette 110 can be drawn from the lower casing 21 in the front direction (a front direction of a paper surface in
The paper feed section 11 includes a pickup roller 112, and a first paper feed roller 113. The paper feed section 11 sends the sheet S in the cassette 110 to a sheet conveying path PP. The sheet conveying path PP is a conveying path arranged so that the sheet from the paper feed section 11 passes through a transfer position TP, which is arranged in the image forming section 120, through the pair of registration rollers 116.
The pickup roller 112 is disposed over the front head edge of the sheet S pressed upward by the lift plate 111. When the pickup roller 112 rotates, the sheet S is sent from the cassette 110 to the first paper feed roller 113.
The first paper feed roller 113 is arranged on a downstream side in a sheet conveying direction of the pickup roller 112. The first paper feed roller 113 sends the sheet S further downstream in the sheet conveying direction. In addition, a counter roller 115 is disposed to face the first paper feed roller 113 below the first paper feed roller 113. A paper feed nip into which the sheet S is sent is formed at a facing portion between the first paper feed roller 113 and the counter roller 115.
A second paper feed roller 114 is arranged on the inside of the lower end 240A of the manual feed tray 240. The second paper feed roller 114 conveys a sheet on the manual feed tray 240 into the lower casing 21. The user can selectively use the sheet S housed in the cassette 110, or the sheet S loaded on the manual feed tray 240.
The conveyance junction section 101 is a portion in which a sheet conveying path extending from the cassette 110 and a sheet conveying path extending from the manual feed tray 240 are joined. The conveyance junction section 101 will be described later in further detail.
The pair of registration rollers 116 defines a position of the sheet in a direction orthogonal to the sheet conveying direction. Thereby, a position of an image to be formed on the sheet S is adjusted. The pair of registration rollers 116 form a nip portion between the rollers. The pair of registration rollers 116 convey the sheet S to the image forming section 120 at such a time that a toner image will be transferred onto the sheet S in the image forming section 120. In addition, the pair of registration rollers 116 have a function of correcting any skewing of the sheet S.
The image forming section 120 includes a photosensitive drum 121, a charging device 122, an exposing device 123, a developing device 124, a toner container 125, a transfer roller 126, a cleaning device 35, a static eliminator 50, and the like.
The photosensitive drum 121 has a substantially cylindrical body shape. The photosensitive drum 121 is configured to have an electrostatic latent image formed on a peripheral surface thereof and carry a toner image based on the electrostatic latent image.
The charging device 122 substantially uniformly electrifies the peripheral surface of the photosensitive drum 121 by applying a predetermined voltage thereto. The exposing device 123 radiates laser light to the peripheral surface of the photosensitive drum 121 electrified by the charging device 122. The laser light is radiated based on image data output from an external device (not illustrated), such as a personal computer, which is connected to the image forming apparatus 1 and capable of communication therewith. As a result, an electrostatic latent image is formed on the peripheral surface of the photosensitive drum 121 corresponding to the image data.
The developing device 124 supplies toner to a peripheral surface of the photosensitive drum 121 with the electrostatic latent image formed thereon. The toner container 125 supplies toner to the developing device 124. The toner container 125 supplies toner to the developing device 124 sequentially or as necessary. If toner is supplied to the photosensitive drum 121 by the developing device 124, the electrostatic latent image formed on the peripheral surface of the photosensitive drum 121 is developed (visualized). As a result, a toner image is formed on the peripheral surface of the photosensitive drum 121. The developing device includes a developing roller 124A configured to carry toner on a peripheral surface thereof. The developing roller 124A is disposed to face the photosensitive drum 121 at a developing position. The developing roller 124A is rotatably driven to supply toner to the photosensitive drum 121.
The transfer roller 126 is arranged to face the peripheral surface of the photosensitive drum 121 at the transfer position TP. In the transfer position TP, the transfer roller 126 is rotationally driven in the same direction as the photosensitive drum 121. The toner image formed on the peripheral surface of the photosensitive drum 121 is transferred onto the sheet S in the transfer position TP.
The cleaning device 35 removes toner remaining on the peripheral surface of the photosensitive drum 121 after the toner image is transferred onto the sheet S. The static eliminator 50 radiates a predetermined static-eliminating light to the photosensitive drum 121 whose peripheral surface has been cleaned by the cleaning device 35. As a result, the photosensitive drum 121 has a uniform potential across the peripheral surface thereof.
After the photosensitive drum 121 is cleaned by the cleaning device 35, the peripheral surface of the photosensitive drum 121 from which static has been eliminated by the static eliminator 50 passes below the charging device 122 again to be uniformly electrified. Thereafter, the above-described forming of the toner image is carried out again.
The image forming apparatus 1 further includes a fixing device 130 configured to fix the toner image onto the sheet S downstream in the conveying direction from the image forming section 120. The fixing device 130 includes a heating roller 131 for melting toner onto the sheet S, and a pressing roller 132 for pressing the sheet S to the heating roller 131. When the sheet S passes between the heating roller 131 and the pressing roller 132, the toner image is fixed to the sheet S.
The image forming apparatus 1 further includes a pair of conveying rollers 133 arranged downstream from the fixing device 130, a switching section 70 arranged downstream from the pair of conveying rollers 133, lower discharge rollers 134, and upper discharge rollers 135. The pair of conveying rollers 133 convey the sheet S subjected to the fixing process by the fixing device 130 downstream in the sheet conveying direction. The switching section 70 has a function of switching the conveying direction of the sheet S downstream in the sheet conveying direction from the pair of conveying rollers 133. The lower discharge rollers 134 are disposed at the left of the switching section 70 to discharge the sheet S conveyed by the pair of conveying rollers 133 to the paper ejection section 241. The upper discharge rollers 135 are disposed above the lower discharge rollers 134 to discharge the sheet S conveyed by the pair of conveying rollers 133 to a paper ejection tray 242 mounted above the paper ejection section 241.
Next, the conveyance junction section 101 according to this embodiment will be described with reference to
The first sheet conveying path P1 (a first conveying path) is a conveying path configured to convey the sheet S1 (the first sheet) fed from the cassette 110. The sheet S1 is conveyed to the right and slightly upward on the first sheet conveying path P1. As described above, the sheet S1 passes through the paper feed nip formed between the first paper feed roller 113 and the counter roller 115, and enters the conveyance junction section 101 (an arrow line D1 in
The second sheet conveying path P2 (a second conveying path) is a conveying path configured to convey the sheet S2 (the second sheet) fed from the manual feed tray 240. The sheet S2 is conveyed to the left and upward on the second sheet conveying path P2. In addition, the second sheet conveying path P2 is joined with the first sheet conveying path P1 in the conveyance junction section 101. A counter pad 117 is disposed below the above-described second paper feed roller 114.
The counter pad 117 is a member configured to form a paper feed nip between the counter pad and the second paper feed roller 114. The counter pad 117 is disposed to face the second paper feed roller 114 to the left of and below the second paper feed roller 114. The counter pad 117 includes a pad base part 117A, a pad front end part 117B, and a pad frictional part 117C. The pad base part 117A is a main body part of the counter pad 117, and a plate-shaped member disposed to face the second paper feed roller 114. The pad front end part 117B extends to the left from an upper end part of the pad base part 117A. The pad frictional part 117C is fixed to an upper surface portion of the pad base part 117A. The pad frictional part 117C abuts a peripheral surface of the second paper feed roller 114 to form a paper feed nip between the pad fictional part and the peripheral surface of the second paper feed roller 114. In order to suitably separate the sheet S2 loaded in the manual feed tray 240, the pad frictional part 117C is made of a material with a high frictional coefficient. As the second paper feed roller 114 rotates, the sheet S2 passes between the second paper feed roller 114 and the pad frictional part 117C, and enters the conveyance junction section 101 (an arrow line D2 in
Further, the third sheet conveying path P3 (a third conveying path) is a conveying path disposed upward from the bottom between the first sheet conveying path P1 and the second sheet conveying path P2. The third sheet conveying path P3 is a conveying path that reaches the conveyance junction section 101 through a connection opening section 21R illustrated in
A guide member 90 is disposed in the above-described conveyance junction portion (in other words, the conveyance junction section 101) of the three sheet conveying paths. The sheet S conveyed from any sheet conveying path is guided by the guide member 90 to enter a joining conveyance path 15 (
Referring to
The supporting point portion 901 is disposed at a central part of the guide member 90 in a lengthwise direction as seen from the cross-section. The supporting point portion 901 serves as a supporting point during the pivoting of the guide member 90. In addition, the guide member 90 is pivoted around the supporting point portion 901 as the supporting point, and can shift between a first position 90A and a second position 90B in
The guide part 901A is a portion extending upward from the supporting point portion 901 of the guide member 90. The guide part 901A has a shape that slightly tapers toward an upper end thereof. The guide part 901A includes a left guide surface 902 and a right guide surface 903 which are a pair of side surfaces. The left guide surface 902 is a left side surface of the guide part 901A, and the right guide surface 903 is a right side surface of the guide part 901A.
The abutting part 901B (a protruding part) is a portion extending downward (upstream in a third direction) from the supporting point portion 901 of the guide member 90. In addition, the abutting part 901B includes a region with an outwardly protruding shape adjacent to the supporting point portion 901 thereof on the left side portion. In addition, in the above-described first position 90A of the guide member 90, a left guide surface upstream part 90S which is a wall surface of the protruding part is disposed along a guide part 118A of the cover member 118 to define a part of the first sheet conveying path P1. Further, during the pivoting of the guide member 90, when the abutting part 901B abuts the pad front end part 117B of the counter pad 117, the second position 90B of the guide member 90 is defined. In this case, the right side portion of the abutting part 901B defines a part of the second sheet conveying path P2. In addition, when the abutting part 901B (a lower end part of the left guide surface upstream part 90S) abuts the protective part 118B of the cover member 118, the first position 90A of the guide member 90 is defined.
Further, in this embodiment, the center of the guide member 90 is set so that the guide member 90 is disposed at the first position 90A by a self weight of the guide member 90. In addition, as another embodiment, it may be possible to set the supporting point portion 901 or the guide member 90 to have a helical spring (not illustrated) installed thereon, such that when no other external force is applied to the guide member 90, the guide member 90 is disposed at the first position 90A by a biasing force of the helical spring.
Further, a wall part 119 is disposed to face the guide member 90 on the right of the guide member 90. The wall part 119 is integrally fixed to a casing opening and closing section (an access cover member) 21A to be described later. The wall part 119 defines a downstream end part in the conveying direction of the second sheet conveying path P2 between the wall part and the guide member 90.
Next, the operation of the guide member 90 when the sheet enters the conveyance junction section 101 through each sheet conveying path will be described.
When the sheet S1 housed in the cassette 110 is conveyed into the first sheet conveying path P1, as described above, the guide member 90 is disposed at the first position 90A by the self weight of the guide member 90. Therefore, the sheet S1 passing between the first paper feed roller 113 and the counter roller 115 is guided upward by the left guide surface 902 of the guide member 90 in the first position 90A, while sliding on the guide part 118A and the left guide surface upstream part 90S. In addition, the sheet S1 is conveyed to the pair of registration rollers 116 from the joining conveyance path 15, while sliding on a second wall part 151. Further, in the image forming apparatus 1, the sheet S1 loaded in the cassette 110 is fed more frequently than the manual feed tray 240, and thereby the sheet S1 is stably conveyed by setting a position at which the guide member 90 is normally disposed as the first position 90A.
Meanwhile, the sheet S2 loaded in the manual feed tray 240 passes between the second paper feed roller 114 and the counter pad 117, and then is conveyed toward the guide member 90 disposed at the first position 90A by the self weight. In this case, in this embodiment, the angle of the counter pad 117 (the pad frictional part 117C) is set beforehand so that the front edge of the sheet S2 conveyed on the second sheet conveying path P2 abuts a contacting part 90P disposed at an upper portion of the supporting point portion 901 of the right guide surface 903 of the guide member 90. Therefore, when the front edge of the sheet S2 abuts the contacting part 90P, the guide member 90 is pivoted around the supporting point portion 901 to be disposed at the second position 90B. Thus, the sheet S2 is guided upward, while sliding on the right guide surface 903 of the guide member 90 in the second position 90B. Further, the sheet S2 is conveyed to the pair of registration rollers 116 from the joining conveyance path 15, while sliding on the first wall part 150.
Further, the sheet S3 fed from the post-attachment type paper feed cassette (not illustrated) is conveyed into the third sheet conveying path P3 through the connection opening section 21R (an arrow line D3 in
As described above, according to this embodiment, the sheet S conveyed from the first sheet conveying path P1, the second sheet conveying path P2, and the third sheet conveying path P3 is stably guided to the joining conveyance path 15 by pivoting of the guide member 90. In this case, the supporting point for the pivoting of the guide member 90 is disposed at the central part of the guide member 90 in a lengthwise direction, thereby it is possible to pivot the guide member 90 with a large range of movement in as reduced a space as possible. In particular, in this embodiment, as illustrated in
As described above, when the swing guide 95 is swung around the supporting point 951 disposed at the lower end part of the swing guide 95, because the supporting point 951 and the upper end part of the swing guide 95 are separate from each other, the range of movement of the swing guide 95 becomes narrow. In
Further, in this embodiment, even if a sheet S becomes clogged in the conveyance junction section 101, the sheet S is easily removed due to the position of the guide member 90.
According to the embodiment described above, in the first position 90A, the guide member 90 guides the sheet S1 conveyed on the first sheet conveying path P1 to the joining conveyance path 15. In addition, in the second position 90B, the guide member 90 guides the sheet S2 conveyed on the second sheet conveying path P2 to the joining conveyance path 15. The guide member 90 is pivoted around the supporting point portion 901 disposed at the central part thereof in the lengthwise direction. Therefore, as the guide member 90 switches the conveying path of the sheet S guided to the joining conveyance path 15 between the first sheet conveying path P1 and the second sheet conveying path P2, the range of the movement of the guide member 90 is mostly covered, compared to the case in which the supporting point is disposed at one end of the guide member 90 in the lengthwise direction.
That is, in this embodiment, the pivoting operation of the guide member 90 is conducted so as to significantly pivot around the supporting point portion 901 with a reduced space, as described above. Therefore, the operation in which the right guide surface 903 and the left guide surface 902 downstream in the sheet conveying direction from the supporting point portion 901 become a part of the joining conveyance path 15 by pivoting of the guide member 90 around the supporting point portion 901 for switching, and the abutting part 901B upstream in the sheet conveying direction from the supporting point portion 901 abuts the pad front end part 117B or the protective part 118B can be achieved with a reduced space. Thereby, it is possible to shape the guide member 90 which pivots for switching along the shape of the first sheet conveying path P1, the second sheet conveying path P2, and the third sheet conveying path P3 with a reduced space.
In addition, according to the embodiment described above, if the guide member 90 is pivoted around the supporting point portion 901, the abutting part 901B of the guide member 90 defines a part of the first sheet conveying path P1 and the second sheet conveying path P2. Therefore, the guide member 90 can suitably guide the sheet along the shape of the sheet conveying path with a switchable conveying direction.
Further, according to the embodiment described above, the guide member 90 is stably disposed at the first position 90A by the self weight or the biasing force of the biasing member provided in the supporting point portion 901. Therefore, the sheet S1 conveyed on the first sheet conveying path P1 can be correctly guided to the joining conveyance path 15. Further, when the front edge of the sheet S2 conveyed on the second sheet conveying path P2 abuts the guide member 90, the guide member 90 is shifted from the first position 90A to the second position 90B. Therefore, even if the guide member 90 is disposed at the first position 90A, the sheet S2 conveyed on the second sheet conveying path P2 can be correctly guided to the joining conveyance path 15.
Further, according to the embodiment described above, the front edge of the sheet S2 abuts the contacting part 90P downstream (on an upper side) in the second direction from the supporting point portion 901, and thereby the guide member 90 can be correctly shifted from the first position 90A to the second position 90B.
Further, according to the embodiment described above, in the open state of the casing opening and closing section 21A, the wall part 119 is separated from the guide member 90, and thereby a part of the second sheet conveying path P2 is opened to the outside of the lower casing 21. In addition, when the guide member 90 is disposed at the first position 90A, a part of the first sheet conveying path P1 is exposed to the outside of the lower casing 21. Therefore, in the area around the guide member 90, even if the sheet S becomes clogged in the first sheet conveying path P1 or the second sheet conveying path P2, the sheet S can be easily removed.
Further, according to the embodiment described above, the guide member 90 can guide the sheet S3 to the joining conveyance path 15 (upward), which is conveyed on the third sheet conveying path P3, in addition to the first sheet conveying path P1 and the second sheet conveying path P2.
Although the paper feed device 10 according to the embodiment of the present disclosure and the image forming apparatus 1 were described above, the present disclosure is not limited thereto, and can take a modified embodiment as follows for example.
(1) In the embodiment described above, it was described that three conveying paths of the first sheet conveying path P1, the second sheet conveying path P2, and the third sheet conveying path P3 are joined in the conveyance junction section 101, but the present disclosure is not limited thereto. The conveyance junction section 101 may be any one in which a plurality of conveying paths are joined. Further, none of the first sheet conveying path P1, the second sheet conveying path P2 and the third sheet conveying path P3 is limited to extending from the cassette 110, the manual feed tray 240, and the post-attachment type paper feed cassette (not illustrated), but may be any one in which the sheet is conveyed toward the conveyance junction section 101.
(2) Further, in the embodiment described above, it was described that the guide member 90 is disposed at the first position 90A by the self weight, but the present disclosure is not limited thereto. The guide member 90 may be disposed at the first position 90A as a standby position by the biasing force of the helical spring, or the like, and further may be disposed at the second position 90B or the third position 90C as a standby position.
(3) Further, in the embodiment described above, it was described the guide member 90 is stopped in the first position 90A when the casing opening and closing section 21A is open in
Various modified embodiments and alterations of this disclosure will be apparent to those skilled in the art without departing from the scope and spirit of this disclosure, and it should be understood that this disclosure is not limited to the illustrative embodiments set forth herein
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-173606 | Aug 2012 | JP | national |
