JP5080932B2 - Manual sheet feeder and image forming apparatus having the same - Google Patents

Description

  The present invention relates to a manual sheet feeding device for feeding a sheet from a manual tray toward an image forming unit, and an image forming apparatus including the same.

In an image forming apparatus such as a copying machine or a printer that employs an electrophotographic system, a sheet is fed to an image forming unit, and a toner image formed on an image carrier in the image forming unit is transferred onto the sheet. An image is formed through a process of fixing the toner image onto a sheet. As a method of feeding a sheet to an image forming unit, a plurality of sheets are stacked and accommodated in a sheet cassette in advance. One of the paper feeding method for picking up one sheet at a time and feeding it to the image forming unit, and the manual feeding method for feeding the paper loaded on the manual tray one by one to the image forming unit. (For example, refer to Patent Documents 1 and 2).
JP-A-2005-200112 JP 2002-167083 A

  By the way, in the conventional manual paper feeder for manually feeding paper, when the manual tray is opened, the manual tray is rotated around its fulcrum by its own weight, so that a large impact sound is generated due to the impact of free fall. At the same time, there has been a problem that a large impact load acts on the components of the manual feed tray and its durability is lowered.

  The present invention has been made in view of the above-described problems, and the object of the present invention is to prevent the generation of impact sound when opening the manual feed tray and to improve the durability of the components of the manual feed tray. It is an object of the present invention to provide a paper device and an image forming apparatus including the same.

To achieve the above object, a first aspect of the present invention, in the manual sheet feeder for feeding one by one toward the image forming unit by the sheet feed roller the stacked paper openable manual feed tray, wherein The manual tray is opened and closed in two stages by temporarily stopping the rotation of the manual tray at a first fixed position, which is an angular position where paper cannot be set on the manual tray. To do.

The invention according to claim 2 is the guide according to claim 1, wherein the manual feed tray is constituted by a manual feed cover and a manual feed base that rotate around different fulcrums, and is formed on both sides of the manual feed cover. a pin projecting from the distal end sides of the manual feed base is engaged with the hole, you characterized by forming the protrusions in the middle of the two guide holes.

The invention according to claim 3 is the invention according to claim 1 or 2 , wherein the opening operation of the first stage of the manual feed tray is performed by pushing the outside of the manual feed tray inward, and the opening of the second stage is performed. The operation is performed by placing the hand inside the manual feed tray that is half-opened by the opening operation of the first stage and fully opening the manual feed tray.

An image forming apparatus according to a fourth aspect includes the manual sheet feeding device according to any one of the first to third aspects.

  According to the first aspect of the present invention, since the manual tray is opened and closed in two stages, the impact when the manual tray is opened is suppressed to a small level, and the generation of impact sound is suppressed. The impact load acting on the surface is also kept small and the durability is improved.

Further, according to the first aspect of the invention, since the manual feed tray, and this the rotation operation at a first fixing position is the angular position which can not load the paper so as to suspend the user manual tray There is no problem that the paper is manually fed with the paper set in a state where the paper is half open.

According to the second aspect of the present invention, when the manual feed tray is opened, the pins of the manual feed base slide along the guide holes of the manual feed cover, but the manual trays come into contact with the projections formed in the guide holes. Is fixed once in a half-open state, and then the user pushes the manual feed tray downward, so that the pins of the manual feed base get over the projections of the guide holes of the manual feed cover and the manual feed tray is fully opened. For this reason, the opening / closing operation of the manual feed tray is performed in two stages, the generation of impact sound is prevented, and the durability of the components of the manual feed tray is improved.

According to the third aspect of the present invention, even in a manual sheet feeding device that employs a push latch or a push catch system that opens the manual tray by pushing the manual tray from the outside to the inside by the first stage opening operation. Since the manual feed tray is temporarily fixed in a half-open state by the opening operation of the step, the generation of impact sound is prevented and the durability of the components of the manual feed tray is improved.

According to the fourth aspect of the present invention, it is possible to prevent the generation of impact sound when the manual feed tray is opened in the image forming apparatus, and to improve the durability of the components of the manual feed tray so that the manual paper feeding can be stably performed. It can be carried out.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
[Image forming apparatus]
1 is a perspective view of a color laser printer as an embodiment of an image forming apparatus according to the present invention, FIG. 2 is a perspective view showing a state in which a manual feed tray of the color laser printer is opened, and FIG. 3 is a side of the color laser printer. It is sectional drawing.

  In the illustrated color laser printer, an inclined concave discharge tray 21 is provided at the center of the upper surface of a box-shaped apparatus main body (housing) 100, and the front surface of the apparatus main body 100 (FIGS. 1 to 3). A front cover 50 that can be opened and closed is provided on the right side in FIG.

  The front cover 50 is provided with a manual feed tray 40 that can be opened and closed. The manual feed tray 40 and a manual feed roller 41 that is rotatably provided in the apparatus main body 100 behind the manual feed tray 40 are provided in the present invention. The manual sheet feeding device according to FIG. The details of the manual sheet feeder will be described later.

  Thus, the color laser printer is of a tandem type, and as shown in FIG. 3, a magenta image forming unit 1M, a cyan image forming unit 1C, a yellow image forming unit 1Y, The black image forming units 1BK are arranged in tandem at regular intervals.

  The image forming units 1M, 1C, 1Y, and 1BK are provided with photosensitive drums 2a, 2b, 2c, and 2d, respectively, and around the photosensitive drums 2a to 2d, chargers 3a, 3b, 3c, 3d, developing devices 4a, 4b, 4c and 4d, transfer rollers 5a, 5b, 5c and 5d as transfer means, and drum cleaning devices 6a, 6b, 6c and 6d are arranged, respectively.

  Here, the photosensitive drums 2a to 2d are drum-shaped photosensitive members, and are rotationally driven at a predetermined process speed in a direction indicated by an arrow (clockwise) by a variable speed stepping motor (not shown). The chargers 3a to 3d uniformly charge the surfaces of the photosensitive drums 2a to 2d to a predetermined potential by a charging bias applied from a charging bias power source (not shown).

  Further, the developing devices 4a to 4d contain magenta (M) toner, cyan (C) toner, yellow (Y) toner, and black (BK) toner, respectively, and are formed on the respective photosensitive drums 2a to 2d. In addition, the toner of each color is attached to each electrostatic latent image to visualize each electrostatic latent image as a toner image of each color.

  The transfer rollers 5a to 5d as transfer means are disposed so as to be in contact with the photosensitive drums 2a to 2d via the intermediate transfer belt 7 in each primary transfer portion. Here, the intermediate transfer belt 7 is stretched between the secondary transfer counter roller 8 and the tension roller 9 and is disposed on the upper surface side of each of the photosensitive drums 2a to 2d. The roller 8 is disposed so as to be in contact with the secondary transfer roller 10 via the intermediate transfer belt 7 in the secondary transfer portion. A belt cleaning device 11 is provided in the vicinity of the tension roller 9.

  Incidentally, toner containers 12a, 12b, 12c and 12d for supplying toner to the developing devices 4a to 4d are arranged in a line above the image forming units 1M, 1C, 1Y and 1BK in the apparatus main body 100. It is installed.

  In addition, a laser scanner unit (LSU) 13 is disposed below each image forming unit 1M, 1C, 1Y, 1BK in the apparatus main body 100, and a paper feed cassette 14 is detachably attached to the bottom of the apparatus main body 100 below the image forming unit 1M, 1C, 1Y, 1BK. Is installed. A plurality of sheets (not shown) are stacked and accommodated in the paper feed cassette 14, and a pickup roller 15 for taking out the paper one by one from the paper feed cassette 14 is taken out in the vicinity of the paper feed cassette 14. A feed roller 16 and a retard roller 17 are provided for feeding the fed paper to the transport path L.

  In addition, the conveyance path L extending in the vertical direction on the side of the apparatus main body 100 includes a conveyance roller pair 18 that conveys the sheet, and the secondary transfer counter roller 8 and the second transfer opposing roller 8 at a predetermined timing after the sheet is temporarily held. A registration roller pair 19 is provided to be supplied to a secondary transfer portion which is a contact portion with the next transfer roller 10. Next to the transport path L, another transport path L ′ used for forming an image on both sides of the sheet is formed, and a plurality of transport roller pairs 20 are appropriately used in the transport path L ′. Are provided at regular intervals.

  By the way, the conveyance path L arranged in the vertical direction on one side in the apparatus main body 100 extends to the paper discharge tray 21 provided on the upper surface of the apparatus main body 100, and the fixing device 22 and the discharge path are in the middle. A paper roller pair 23 and a paper discharge device 24 are provided.

  Next, an image forming operation by the color image forming apparatus having the above configuration will be described.

  When an image formation start signal is issued, the photosensitive drums 2a to 2d are driven to rotate at a predetermined process speed in the direction of the arrow in FIG. 1 (clockwise) in each of the image forming units 1M, 1C, 1Y, and 1BK. The drums 2a to 2d are uniformly charged by the chargers 3a to 3d. The laser scanner unit 13 emits a laser beam modulated by a color image signal for each color, irradiates the surface of each photosensitive drum 2a to 2d with the laser beam, and each color is applied to each photosensitive drum 2a to 2d. An electrostatic latent image corresponding to the color image signal is formed.

  First, magenta toner is attached to the electrostatic latent image formed on the photosensitive drum 2a of the magenta image forming unit 1M by the developing device 4a to which a developing bias having the same polarity as the charged polarity of the photosensitive drum 2a is applied. The electrostatic latent image is visualized as a magenta toner image. This magenta toner image is transferred to the arrow shown in FIG. 1 by the action of the transfer roller 5a to which a primary transfer bias having a polarity opposite to that of the toner is applied at the primary transfer portion (transfer nip portion) between the photosensitive drum 2a and the transfer roller 5a. Primary transfer is performed on the intermediate transfer belt 7 which is rotationally driven in the direction.

  The intermediate transfer belt 7 on which the magenta toner image has been primarily transferred as described above moves to the next cyan image forming unit 1C. In the cyan image forming unit 1C as well, the cyan toner image formed on the photosensitive drum 2b is transferred to the magenta toner image on the intermediate transfer belt 7 in the primary transfer portion in the same manner as described above.

  Similarly, yellow and black toners respectively formed on the photosensitive drums 2c and 2d of the yellow and black image forming units 1Y and 1BK on the magenta and cyan toner images superimposed and transferred on the intermediate transfer belt 7, respectively. The images are sequentially superimposed at each primary transfer portion, and a full-color toner image is formed on the intermediate transfer belt 7. The transfer residual toner which is not transferred onto the intermediate transfer belt 7 and remains on the photosensitive drums 2a to 2d is removed by the drum cleaning devices 6a to 6d, and the photosensitive drums 2a to 2d are prepared for the next image formation. It is done.

  Then, the pickup from the paper feed cassette 14 is performed in accordance with the timing at which the front end of the full color toner image on the intermediate transfer belt 7 reaches the secondary transfer portion (transfer nip portion) between the secondary transfer counter roller 8 and the secondary transfer roller 10. The sheet fed to the conveyance path L by the roller 15, the feed roller 16 and the retard roller 17 is conveyed to the secondary transfer unit by the registration roller pair 19. Then, a full-color toner image is collectively transferred from the intermediate transfer belt 7 to the sheet conveyed to the secondary transfer unit by the secondary transfer roller 10 to which a secondary transfer bias having a polarity opposite to that of the toner is applied. .

  Thus, the sheet on which the full-color toner image has been transferred is conveyed to the fixing device 22, and the sheet on which the full-color toner image has been fixed by being heated and pressurized and thermally fixed on the surface of the sheet. Then, the paper is conveyed to the paper discharge device 24 by the paper discharge roller pair 23 and is discharged onto the paper discharge tray 21 by the paper discharge device 24 to complete a series of image forming operations. The transfer residual toner that is not transferred onto the sheet and remains on the intermediate transfer belt 7 is removed by the belt cleaning device 11, and the intermediate transfer belt 7 is prepared for the next image formation.

When the user manually feeds paper, the manual tray 40 is opened as shown in FIG. 2, and the sheets stacked on the manual tray 40 are fed to the registration roller pair 19 shown in FIG. Thereafter, a color image is formed on the paper through the same process as described above.
[Manual feeding device]
Next, the configuration of the manual sheet feeder 6 according to the present invention will be described.

  4 is a side view of the manual feed tray, FIG. 5 is a perspective view of the manual feed tray, FIG. 6 is a perspective view of the manual feed cover of the manual feed tray, FIG. 7 is a perspective view of the manual feed base of the manual feed tray, and FIG. FIG. 9 is a partial side view showing a first fixed state of the manual paper feed tray, FIG. 10 is an enlarged detail view of part A of FIG. 9, and FIG. 11 is a portion showing the first fixed state of the paper feed tray. FIG. 12 is a partial perspective view showing a second fixed state (fully opened state) of the paper feed tray.

  As shown in FIGS. 4 and 5, the manual feed tray 40 includes a manual feed cover 26 and a manual feed base 27 that rotate around different fulcrums. As shown in FIGS. 4 and 12, the manual feed tray 40 is also provided with an auxiliary tray 28 that can be pulled out in the direction of the arrow in FIG.

  Here, as shown in FIG. 6, the manual feed cover 26 is formed in a flat rectangular box shape having an open top surface, and support shafts 29 are integrally projected on the left and right sides of the base end portion. By inserting these support shafts 29 into circular hole-shaped bearings 52 (only one is shown in FIG. 8) formed on the inner surfaces of the left and right side walls of the front cover 50 shown in FIG. Rotate up and down around the center. In addition, guide holes 30 that are bent in the shape of “<” are formed in the center portions in the longitudinal direction of the side walls erected vertically on the left and right sides of the manual feed cover 26, respectively. Projections 31 are respectively formed on the portions.

  On the other hand, as shown in FIG. 7, the manual feed base 27 is formed in a rectangular plate shape, and shafts 32 project from the respective base end portions of the side walls standing vertically on the right and left sides. As shown in FIGS. 4 and 5, the long holes 34 of the left and right link levers 33 are inserted into the shaft 32. Accordingly, each link lever 33 is rotatable about the shaft 32 of the manual feed base 27, and a support shaft 35 is integrally projected at the end thereof, and each support shaft 35 is shown in FIG. The front cover 50 is fitted into circular hole-shaped bearings 53 formed on the inner surfaces of the left and right side walls.

  As shown in FIG. 7, pins 36 are integrally provided on the left and right of the front end portion of the manual feed base 27, and each pin 36 has a left and right side of the manual feed cover 26 as shown in FIGS. 4 and 5. Is slidably engaged with the guide hole 30 formed in the side wall. Therefore, the left and right of the base end portion of the manual feed base 27 are supported by the front cover 50 via the link lever 33, and the support shaft is interlocked with the vertical rotation around the support shaft 29 of the manual cover 26. The left and right pins 36 are slid along the left and right guide holes 30 of the manual feed cover 26.

  Next, the opening / closing operation | movement of the manual feed tray 40 comprised as mentioned above is demonstrated based on FIGS.

As shown in FIG. 1, when the manual feed tray 40 is closed, the pin 36 of the manual feed base 27 of the manual feed tray 40 is positioned at the uppermost position of the guide hole 30 of the manual feed cover 26 (a position indicated by a chain line in FIG. 10). It is in.

Thus, when the user opens the manual feed tray 40 during manual paper feed, the manual feed cover 26 of the manual feed tray 40 rotates downward (in the direction of the arrow in FIGS. The base 27 rotates in the same direction around the support shaft 35 of the link lever 33, and the pin 36 of the manual feed base 27 slides in the guide hole 30 of the manual feed cover 26 in the direction of the arrow in FIG. Then, when the manual feed tray 40 is rotated by the angle θ shown in FIGS. 9 and 11 until the pin 36 contacts the protrusion 31 of the guide hole 30 (position b in FIG. 10), the pin 36 protrudes from the protrusion 31 of the guide hole 30. Therefore, the turning operation of the manual feed tray 40 is temporarily stopped at the first fixing position shown in FIGS. 9 and 11, and the manual feed tray 40 is fixed. Note that the rotation angle θ until the temporary stop at the temporary fixing position of the manual feed tray 40 is set to a value at which paper cannot be set on the manual feed tray 40 in the temporary stop state.

  In order to fully open the manual feed tray 40 temporarily fixed at the first fixed position as described above, the user needs to push the manual feed tray 40 downward. Then, the pin 36 of the manual feed base 27 moves over the protrusion 31 of the guide hole 30 of the manual feed cover 26 and moves to the lowest position (position c in FIG. 12), and further rotation of the manual feed tray 40 is prevented. Therefore, the manual feed tray 40 is fixed at the second fixing position shown in FIG. Therefore, the user can set sheets on the fully opened manual feed tray 40 and feed the sheets one by one to the image forming unit 8 in the main body 2 shown in FIG. Depending on the size of the paper set on the manual feed tray 40, the auxiliary tray 28 can be pulled out in the direction of the arrow in FIG.

  As described above, in the present embodiment, the opening and closing operation of the manual feed tray 40 is performed in two stages. Therefore, the impact when opening the manual feed tray 40 is suppressed to be small, and the generation of impact sound is suppressed. The impact load acting on the components of the tray 40 is also kept small, and the durability is improved.

  In this embodiment, the manual feed tray 40 is temporarily stopped at the first fixed position by rotating its manual feeding tray 40 at an angular position (the angle θ shown in FIGS. 9 and 11) where paper cannot be set. Since the paper is once fixed, there is no problem that the user sets paper with the manual feed tray 40 half-opened and manually feeds paper.

  By the way, according to the present invention, the first-stage opening operation of the manual feed tray 40 is performed by pushing the outside of the manual-feed tray 40 inward, and the second-stage opening operation is half-opened by the first-stage opening operation. The present invention can also be applied to a manual paper feeding device that employs a so-called push latch or push catch method in which the manual feed tray 40 is fully opened by placing a hand inside the tray 40. Since the manual feed tray 40 is temporarily fixed in the half-opened state by the opening operation of the first stage, the generation of impact sound is prevented and the durability of the components of the manual feed tray 40 is improved. Here, in an image forming apparatus employing this method, a catch 54 shown in FIG. 11 is provided on the apparatus main body 100 side, and a latch 37 shown in FIGS. 5 and 6 is provided on the manual feed tray 40 side.

  In the above description, the present invention has been described with respect to a color laser printer and a manual paper feeder provided therein. However, the present invention is not limited to a printer, and other arbitrary images such as a copying machine and a facsimile machine. Of course, the present invention can be similarly applied to the forming apparatus and the manual sheet feeder provided therein.

1 is a perspective view of an image forming apparatus (color laser printer) according to the present invention. 1 is a perspective view showing a state in which a manual feed tray of an image forming apparatus (color laser printer) according to the present invention is opened. 1 is a side sectional view of an image forming apparatus (color laser printer) according to the present invention. FIG. 3 is a side view of a manual feed tray constituting the manual paper feed device according to the present invention. FIG. 3 is a perspective view of a manual feed tray constituting the manual paper feed device according to the present invention. It is a perspective view of the manual feed cover of the manual feed tray concerning the present invention. It is a perspective view of the manual feed base of the manual feed tray concerning the present invention. 1 is a perspective view of a lower portion of a front cover of an image forming apparatus (color laser printer) according to the present invention. FIG. 6 is a partial side view showing a first fixed state of the manual paper feed tray according to the present invention. FIG. 10 is an enlarged detail view of a part A in FIG. 9. It is a fragmentary perspective view which shows the 1st fixed state of the manual feed tray which concerns on this invention. It is a fragmentary perspective view which shows the 2nd fixed state (fully opened state) of the paper feed tray which concerns on this invention.

Explanation of symbols

1M Magenta image forming unit 1C Cyan image forming unit 1Y Yellow image forming unit 1BK Black image forming unit 2a to 2d Photosensitive drum 3a to 3d Charger 4a to 4d Developing device 5a to 5d Transfer roller 6a to 6d Drum cleaning device 7 Intermediate transfer belt 8 Secondary transfer counter roller 9 Tension roller 10 Secondary transfer roller 11 Belt cleaning device 12a to 12d Toner container 13 Laser scanner unit (LSU)
DESCRIPTION OF SYMBOLS 14 Paper feed cassette 15 Pickup roller 16 Feed roller 17 Retard roller 18 Transport roller pair 19 Registration roller pair 20 Transport roller pair 21 Paper discharge tray 22 Fixing device 23 Paper discharge roller pair 24 Paper discharge device 26 Manual cover 27 Manual feed base 28 Auxiliary tray 29 Manual Cover Cover Shaft 30 Manual Cover Guide Hole 31 Guide Hole Projection 32 Manual Base Shaft 33 Link Lever 34 Link Lever Long Hole 35 Link Lever Spindle 36 Manual Base Pin 37 Latch 40 Manual Tray 41 Paper Feed Roller 50 Front cover 51 Operation panel 52, 53 Bearing 54 Catch 100 Image forming apparatus main body L, L 'Conveyance path

Claims (4)

In a manual sheet feeding device that feeds sheets stacked on an openable and closable manual tray one by one toward an image forming unit by a sheet feeding roller,
The opening and closing operation of the manual feed tray is performed in two stages by temporarily stopping the rotation of the manual feed tray at a first fixed position which is an angular position where paper cannot be set on the manual feed tray. Manual feed device. The manual feed tray is composed of a manual cover and a manual feed base that rotate around different fulcrums, and pins projecting from both sides of the manual feed base are inserted into guide holes formed on both sides of the manual feed cover. is engaged with, claim 1 Symbol placement of the manual sheet feeder, characterized in that the formation of the projections in the middle of the guide hole. The opening operation of the first stage of the manual feed tray is performed by pushing the outside of the manual feed tray inward, and the opening operation of the second stage is performed by placing a hand inside the manual feed tray that is half-opened by the opening operation of the first stage. multiplied by the manual sheet feeder according to claim 1 or 2, wherein the performed by fully opening the該手feed tray. An image forming apparatus comprising the manual sheet feeder according to any one of claims 1-3.

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