JP3951595B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus that records an image on a sheet-like recording medium such as a sheet cut into a predetermined size by an image forming unit.
[0002]
[Prior art]
Various types of image forming apparatuses such as printers, facsimiles, etc. are used such as electrophotographic type, inkjet type, thermal transfer type, etc., but most of them are paper cut to a predetermined size An image such as a character or drawing is formed by an image forming unit on a sheet-like recording medium such as.
[0003]
For example, in the ink jet method or the thermal transfer method, an image is formed on a sheet or the like based on a digital signal.
[0004]
In the electrophotographic system and the electrostatic recording system, an image is formed by applying toner to the electrostatic latent image on the image carrier, and the toner image is transferred and fixed on a sheet or the like.
[0005]
Sheets and the like to which images are provided in this way are generally stacked and stored in a sheet feeding device provided in the image forming apparatus, and are sequentially supplied one by one from here.
[0006]
The paper stored in the paper feeding device needs to be appropriately replenished, and a paper tray that is a cassette that can be attached to and detached from the device main body is used so that this reinforcement can be easily performed. Paper is supplied to the tray and stored.
[0007]
Some of these paper trays are provided in one image forming apparatus, but two or more cassettes are provided in order to select different sizes of paper and apply images. There are also many.
[0008]
There is also an image forming apparatus provided with a manual feed tray that is convenient for arbitrarily using various sizes and various sheets.
[0009]
There is an image forming apparatus having a structure shown in FIG. 8 as a general image forming apparatus having a mechanism for taking out sheets one by one from a paper tray or a manual feed tray and sequentially feeding them to a position where images are applied.
[0010]
In the image forming apparatus 200 shown in FIG. 8, cassette type paper trays 204 and 206 are disposed below the manual feed tray 202.
[0011]
On the back side of the manual feed tray 202, a half-moon roll 210 and a separating member 212 are provided. The half moon roll 210 is brought into contact with the upper surface of the uppermost sheet P accommodated in the manual feed tray 202 and rotates to feed the uppermost sheet P toward the registration roll 214.
[0012]
Also, cassette type paper trays 204 and 206 are arranged below the manual feed tray 202. The paper in the paper tray 204 is sent out toward the registration roll 214 by the paper feed roll 216, and the paper in the paper tray 206 is sent out toward the registration roll 214 by the paper feed roll 218.
[0013]
[Problems to be solved by the invention]
However, the image forming apparatus 200 as described above has the following problems.
[0014]
In the image forming apparatus 200, a guide member 220 that guides the sheet conveyed by the half-moon roll 210 and the sheet P conveyed by the paper feed roll 216 toward the registration roll 214 obliquely below the registration roll 214. Due to the fixed arrangement, there is a problem that the sheet cannot be removed from the inside of the main body when a conveyance failure (also referred to as jamming) of the sheet P occurs in the vicinity of the registration roll 214.
[0015]
Although it is possible to look inside the apparatus from the paper insertion port, the paper P is almost hidden by the guide member 220 and the like, so it is difficult to determine at which part the paper P is jammed.
[0016]
When the conveyance path of the paper P is a so-called C path layout like the image forming apparatus of FIG. 8, the developing device 18 is disposed above the registration roll 214, and the presence or absence of toner in the developing device 18 is detected. The toner sensor 222 is disposed below the developing device 18, that is, on the front side of the sheet conveyance path located below the registration roll 214. This toner sensor 222 also makes it difficult to remove the sheet. It was the cause.
[0017]
[0018]
For example, if the rear end of the paper P can be seen from the opening after the paper tray 204 is pulled out and the paper tray 204 is pulled out, the paper P can be removed. When P is in a state of being compressed in a bellows shape, it is difficult to remove the paper P.
[0019]
[0020]
The invention according to the present application has been made in view of the circumstances as described above, and its purpose is to enable easy removal of paper that has caused a conveyance failure in an image forming apparatus, particularly in the vicinity of a resist roll. is there.
[0021]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a paper tray on which paper is stacked , an image forming unit that is disposed above the paper tray and forms an image on the paper, and is provided inside the apparatus, and is accommodated in the paper tray. A paper feed roll that abuts against the produced paper and feeds the paper, and a resist that is disposed downstream of the paper feed roll in the paper transport direction and transports the paper transported by the paper feed roll to the image forming unit A roll, an upper surface side guide member that is provided upstream of the registration roll in the paper conveyance direction and guides the upper surface side of the stacked paper, the paper tray, the paper feed roll, the registration roll, and the upper surface side accommodating the guide member, and a body cover openable at least a portion, at least a portion of said image forming unit, at least a portion of said body cover is opened From inside the apparatus through the mouth portion is provided detachably, the upper side guide member, wherein at least a portion of said image forming unit is disposed in visible state from the detached space, the paper can guide Between the first position and the second position which is operated from the space and can open the sheet transport path upstream of the registration roll in the sheet transport direction. It is characterized by that.
[0022]
Next, the operation of the image forming apparatus according to the first aspect will be described.
[0023]
The paper feed roll contacts the uppermost paper stored in a stack in the paper tray and transports it to the registration roll side. At this time, the sheet is guided to the registration roll side by the upper surface side guide member arranged at the first position.
[0024]
When the sheet is conveyed to the registration roll, the sheet is conveyed to the image forming unit by the registration roll.
[0025]
Thereafter, an image is formed on the sheet by the image forming unit.
[0026]
Here, when a conveyance failure occurs such that the sheet is jammed in front of the registration roll for some reason, at least a part of the image forming unit is removed from a portion where the inside of the main body cover can be opened.
[0027]
As a result, there is a space above the registration roll from which at least a part of the image forming unit is removed, so that the upper surface side guide member can be visually checked and operated by hand.
[0028]
If the upper surface side guide member is changed to the second position, the paper conveyance path between the paper feed roll and the registration roll is opened toward the space, so it is easy to remove the paper having a conveyance failure before the registration roll. Can be removed.
[0029]
Since the image forming unit is provided on the upper part of the apparatus, the upper part of the main body cover in the vicinity of the image forming unit can be opened, and even when the apparatus is arranged on the wall, the apparatus can be conveyed without moving. The defective paper can be removed.
[0030]
Note that the main body cover that can be opened from at least part of the body includes, for example, a structure in which a door that can be opened and closed is provided in an opening provided in advance in the main body cover, a structure in which a part of the main body cover is removable, and the like. That is. Of course, the entire body cover may be removable.
[0031]
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the image forming unit develops an image carrier and a latent image formed on the image carrier with a toner image. And the upper surface side guide member has a toner sensor capable of detecting the presence or absence of toner in the developing means.
[0032]
Next, the operation of the image forming apparatus according to claim 2 will be described.
[0033]
In the image forming apparatus according to the second aspect, when the upper surface side guide member is moved to the second position, the toner sensor is also separated from the paper transport path and does not interfere with the paper removal operation.
[0034]
According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, a sheet that enters from the lower side of the upper surface side guide member in the vicinity of the upper surface side guide member is fed to the upper surface side guide member. A second guide member for guiding to the side is provided.
[0035]
Next, the operation of the image forming apparatus according to the third aspect will be described.
[0036]
In the image forming apparatus according to claim 3, in the vicinity of the upper side guide member, is provided with the second guide member for guiding the sheet to enter from below the upper side guide member to the upper side guide member, for example, Second and third paper trays are provided below the paper tray to guide the paper in the second and third paper trays to the upper guide member side, or to reverse the paper to the image forming apparatus. When the paper reversing device is connected, the paper can be moved back and forth between the paper reversing device and the upper surface side guide member .
[0037]
According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the second guide member has a first position capable of guiding the paper, and Operated from a space in which at least a part of the image forming unit is removed, the image forming unit is provided so as to be movable between a second position where the sheet conveying path facing the second guide member can be opened. It is characterized by that.
[0038]
Next, the operation of the image forming apparatus according to the fourth aspect will be described.
[0039]
When the second guide member is in the first position, the sheet can be guided.
[0040]
Next, when the second guide member is in the second position, the sheet conveyance path facing the second guide member is opened toward the image forming unit, so that at least a part of the image forming unit is opened. By removing the sheet, it is possible to easily remove the sheet having a conveyance failure near the second guide member.
[0041]
According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the upper surface side guide member is rotatably provided with the registration roll as a rotation center. It is characterized by having.
[0042]
Next, the operation of the image forming apparatus according to the fifth aspect will be described.
[0043]
In the image forming apparatus according to the fifth aspect, the position of the upper surface side guide member can be changed from the first position to the second position by rotating about the registration roll.
[0044]
According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the third to fifth aspects, the part that can open the inside of the main body cover, the image forming unit, and the upper surface side The guide member and the second guide member are arranged on a substantially straight line.
[0045]
Next, the operation of the image forming apparatus according to the sixth aspect will be described.
[0046]
According to the image forming apparatus of the sixth aspect, the part capable of opening the inside of the main body cover, the image forming portion, the upper surface side guide member, and the second guide member are arranged substantially in a straight line . By removing the image forming unit and moving the upper surface side guide member and the second guide member to the second position, it is possible to overlook the transport path of the second guide member located on the innermost side at a time. This makes it possible to easily remove the sheet having a conveyance failure in the conveyance path of the second guide member.
[0047]
DETAILED DESCRIPTION OF THE INVENTION
An image forming apparatus according to an embodiment of the present invention will be described with reference to FIGS.
[0048]
As shown in FIG. 2, the image forming apparatus 10 includes an image carrier (so-called photosensitive drum) 12 on which an electrostatic latent image is formed by irradiating image light after being uniformly charged, and an image. A charging device 14 that uniformly charges the surface of the carrier 12; an image writing device 16 that irradiates the image carrier 12 with preferential light based on image data to form a latent image based on a difference in electrostatic potential; A developing device 18 that selectively transfers and visualizes toner on the image; a transfer device 22 that transfers the toner image on the surface of the image carrier onto the recording paper supplied along the paper conveyance path 20; and a toner on the recording paper. The image forming apparatus includes a fixing device 24 that heats and pressurizes the image to apply a skin, and a cleaning 26 that cleans toner remaining on the image carrier after the toner image is transferred.
[0049]
The image forming apparatus 10 is covered with a main body side cover 10B and a top plate 10A.
[0050]
Here, the image carrier 12, the charging device 14, the developing device 18, and the cleaning 26 function as a single developing unit 27 by opening the top plate 10 </ b> A of the image forming apparatus 10, so that a main body frame (not shown) inside the apparatus. It is easy to attach and detach.
[0051]
The top plate 10A is opened inside by rotating in the arrow CCW direction in FIG. 2 with a shaft 10C provided at the upper end corner portion on the arrow B direction side of the main body side surface cover 10B as a fulcrum.
[0052]
Further, in the lower part of the image forming apparatus 10, a recording paper is stored, and a paper feeding device 28 that feeds the recording paper one by one, and the recording paper sent from the paper feeding device 28 is transferred to a toner image at a predetermined timing. A resist roll 30 is provided for transporting to the center.
[0053]
The image carrier 12 has a photoreceptor layer on the back surface, and the potential of the exposed portion is attenuated by exposure after being uniformly charged.
[0054]
The charging device 14 is a roll-shaped member that comes into contact with the image carrier 12, and when a voltage is applied between them, a discharge is generated in a minute gap near the contact portion, and the image carrier. The surface of the body 12 is charged almost in the same manner.
[0055]
As the charging device, in addition to the above, a device that applies a high voltage to the electrode wire and charges the image carrier by corona discharge can be used.
[0056]
The image writing device 16 scans the flashing laser on the peripheral surface of the image carrier 12 and forms an electrostatic latent image based on the image data on the peripheral surface of the image carrier 12.
[0057]
As the post-writing device, a light emitting element such as an LED may be arranged and blinked based on the image data.
[0058]
The developing device 18 has a cylindrical developing roll 18A disposed so as to face the image carrier 12 in close proximity, and a developing bias voltage is applied between the developing roll 18A and the image carrier 12. The
[0059]
As a result, a developing bias electric field is formed between the developing roll 18A and the image carrier 12, and the charged toner is transferred to the exposed portion on the image carrier 12 to form a visible image.
[0060]
The transfer device 22 is a roll-like member provided so as to face the image carrier 12, and forms a transfer electric field between the image carrier 12 and the toner image on the recording paper passing therethrough. It is to be transferred.
(Paper feeder)
The paper feeding device 28 includes a first paper tray 34, a second paper tray 36 disposed below the first paper tray 34, and a first paper feed that feeds paper from the upper paper tray 34. To the roll 38, the second paper feed roll 40 that feeds paper from the lower paper tray 36, the first sheeting member 42 that is pressed against the first paper feed roll 38, and the second paper feed roll 40 A second whispering member 44 that is press-contacted, a holder 46 that is pivotally attached to the paper tray 34 and supports the first whispering member 42, and a second whispering member 44 that is pivotally attached to the paper tray 36. And a holder 48 for supporting.
[0061]
The paper tray 36 disposed on the lower side is detachable from the main body frame of the image forming apparatus 10 as a cassette, and can be pulled out in the direction opposite to the direction in which the paper is sent out (in the direction of arrow F).
[0062]
Further, the upper paper tray 34 is a manual feed tray, and it is possible to easily insert a paper of an arbitrary size from an opening 49 provided on the side of the image forming apparatus 10 on the arrow F direction side. It has become.
[0063]
The first paper feed roll 38 is a half-moon roll in which a part of the peripheral surface is cut out. When the first paper supply roll 38 is driven to rotate, the peripheral surface comes into contact with the top surface of the uppermost sheet loaded on the paper tray 34, and The top sheet P is sent out sequentially.
[0064]
The first winding member 42 is supported by a holder 46 that is rotatably attached to the paper tray 34, and is biased toward the first paper feed roll 38 by an elastic member such as a spring.
[0065]
A core roll 52 is supported on the shaft 50 of the first paper feed roll 38 so as to be freely rotatable.
[0066]
The first sheeting member 42 is always in contact with the core roll 52, and when the sheet P sent out by the first sheet feeding roll 38 is conveyed by the registration roll 30, the lower sheet is stacked. P is prevented from following the upper sheet P.
[0067]
The second webbing member 44 is supported by a holder 48 that is rotatably attached to the paper tray 36, and is biased toward the second paper feed roll 40 by an elastic member such as a spring.
[0068]
A core roll 56 similar to the shaft 50 of the first paper feed roll 38 is also provided on the shaft 54 of the second paper feed roll 40.
[0069]
The second sheeting member 44 is always in contact with the core roll 56, and when the sheet P fed out by the second sheet feeding roll 40 is conveyed by the registration roll 30, the lower sheet is stacked. P is prevented from following the upper sheet P.
[0070]
The first paper feed roll 38 is provided above the end of the paper tray 34 on the back side (arrow B direction side), and is provided at a position where the paper P accommodated in the paper tray 34 can contact. It has been. The first paper feed roll 38 is rotated by a motor (not shown) controlled by a control device 89 described later.
[0071]
Further, the second paper feed roll 40 is provided above the end of the paper tray 36 on the back side (arrow B direction side), and a position where the paper P accommodated in the paper tray 36 can contact. Is provided. The second paper feed roll 40 is rotated by a motor (not shown) controlled by a control device 89 described later.
[0072]
As shown in FIG. 3, on the arrow B direction side of the first paper feed roll 38, there are a roll 30A arranged on the arrow B direction side and a roll 30B arranged on the arrow F direction side and press-bonded to the roll 30A. A configured resist roll 30 is provided.
[0073]
These rolls 30 </ b> A and 30 </ b> B are rotated by a motor (not shown) controlled by a control device 89 described later.
[0074]
Note that the second paper feed roll 40 is disposed between the first paper feed roll 38 and the registration roll 30.
[0075]
Here, the first tangent line L1 that passes through the separating portion (contact portion) between the first sheet feeding roll 38 and the first separating member 42, and the second sheet feeding roll 40 and the second separating member 44 are connected. It is preferable to arrange a nip point between the roll 30A and the roll 30B of the resist roll 30 between the second tangent line L2 passing through the winding part (contact part), but it protrudes slightly upward from the first tangent line L1. Also good.
[0076]
In the present embodiment, the registration roll 30 is disposed below the horizontal line L <b> 3 that passes through the upper end of the first paper feed roll 38.
[0077]
The second paper feed roll 40 is disposed between the first paper feed roll 38 and the registration roll 30 in the horizontal direction.
[0078]
The first paper feed roll 38, the second paper feed roll 40, and the registration roll 30 are arranged as close as possible while maintaining the above positional relationship, so that the height dimension of the paper feed device 28 (arrow U Directional and arrow D dimensions) and depth dimensions (arrow F and arrow B dimensions) can be rationally minimized.
[0079]
In this embodiment, the distance from the nip point between the rolls 30A and 30B of the registration roll 30 to the nip point between the second paper feed roll 40 and the second winding member 44 is the same as the roll 30A of the registration roll 30. It is set to be smaller than the distance from the nip point of the roll 30B to the nip point between the first paper feed roll 38 and the first separating member 42.
[0080]
As shown in FIGS. 1 and 4, an upper guide assembly 58 is attached to a shaft 30 </ b> Ba of a roll 30 </ b> B of the registration roll 30 through a ring 57 so as to be rotatable and detachable.
[0081]
A substantially C-shaped bearing 59 is formed on both sides of the upper guide assembly 58 in the sheet width direction (the front and back direction in FIG. 1). By elastically deforming the bearing 59, the upper guide with respect to the shaft 30Ba is formed. The assembly 58 is detachable.
[0082]
The upper guide assembly 58 guides the guide surface 60 that guides the lower surface side (when stacked) of the paper P sent out from the first paper feed roll 38, and the paper P sent out from the first paper feed roll 38 ( A guide surface 62 that guides the upper surface side (when stacked) and a guide surface 64 that guides the upper surface side (when stacked) of the paper P fed from the second paper feed roll 40 are provided.
[0083]
1 and 4 show the upper guide assembly 58 in the normal state of the image forming apparatus 10.
[0084]
As shown in FIG. 1, the guide surface 60 includes a straight portion 60A formed on the first paper feed roll 38 side and having a substantially straight cross-sectional shape along the paper conveyance direction, and a resist roll of the straight portion 60A. The first arc portion 60B formed on the side 30 and having a cross-sectional shape along the paper conveyance direction formed in a convex arc shape, and the cross-sectional shape formed on the resist roll 30 side of the first arc portion 60B along the paper conveyance direction. And a second arc portion 60C formed in a concave arc shape.
[0085]
On the other hand, the guide surface 62 is provided so as to face the guide surface 60, and has a cross-sectional shape along the paper conveyance direction at a position substantially opposite to a part of the linear portion 60A of the guide surface 60 and the first arc portion 60B. A substantially straight upper plane portion 62A is provided, and a cross-sectional shape along the sheet conveyance direction is formed in a convex arc shape at a position facing the second arc portion 60C on the registration roll 30 side of the upper plane portion 62A. A circular arc part 62B is provided.
[0086]
Note that the gap between the guide surface 60 and the guide surface 62 gradually decreases toward the registration roll 30, and transports the paper P transported by the first paper feed roll 38 toward the registration roll 30. A route 65 is provided.
[0087]
The upper guide assembly 58 is rotatably provided with a small diameter roller 66 at the lower end of the guide surface 64. The roller 66 rotates by contacting the paper P to be conveyed.
[0088]
A toner sensor (magnetic sensor) 90 that can detect the presence or absence of toner in the developing device 18 provided in the developing unit 27 is attached to the upper portion of the upper guide assembly 58.
[0089]
Next, as shown in FIG. 3, a fixed guide surface 68 is provided on the main body frame side of the image forming apparatus 10 on the arrow B direction side of the upper guide assembly 58.
[0090]
The fixed guide surface 68 includes a substantially vertical vertical surface portion 68A provided at a position facing the guide surface 64, an inclined portion 68B extending toward the diagonally upper side on the arrow B direction side and smoothly connected to the upper end of the vertical surface portion 68A, and a vertical An arc portion 68C having a cross-sectional shape along the paper conveyance direction smoothly connected to the lower end of the surface portion 68A and having a downward convex shape is provided.
[0091]
Between the fixed guide surface 68 and the guide surface 64, there is a transport path 69 for guiding the paper P transported from below toward the registration roll 30.
[0092]
The fixed guide surface 68 is rotatably provided with a small-diameter roller 70 at a connection portion between the vertical surface portion 68A and the inclined portion 68B.
[0093]
A part of the roller 70 protrudes from the fixed guide surface 68, and rotates when it comes into contact with the conveyed paper P.
[0094]
Normally, the upper guide assembly 58 is locked by a lock claw (not shown) so that the guide surface 64 and the vertical surface portion 68A face each other (position shown in FIGS. 1, 3 and 4).
[0095]
The upper guide assembly 58 can be rotated in the direction of the arrow CCW (counterclockwise direction in FIG. 5) as shown in FIG. 5 by unlocking the lock claw. The vertical surface portion 68A is greatly exposed upward.
[0096]
Further, on the main body frame side of the image forming apparatus 10, a lower guide assembly 72 is provided obliquely below the second paper feed roll 40 in the direction of arrow B.
[0097]
As shown in FIG. 5, the lower guide assembly 72 guides the fixed guide surface 72 </ b> A facing the fixed guide surface 68 and the paper P conveyed from the second paper feed roll 40 toward the registration roll 30. A fixed guide surface 72B having a substantially concave arc shape in cross section along the paper conveyance direction is provided.
[0098]
The fixed guide surface 72B is provided only at the center portion in the paper width direction (the front and back direction in FIG. 5) perpendicular to the paper conveyance direction of the lower guide assembly 72, and is provided on both sides of the fixed guide surface 72B in the paper width direction. A movable guide member 74 is provided.
[0099]
The movable guide member 74 is rotatably attached to the shaft 73 of the lower guide assembly 72, and has a guide surface 74A formed in the same cross-sectional shape as the fixed guide surface 72A in the central portion, and a fixed guide surface 72B in the central portion. And a guide surface 74B formed in the same cross-sectional shape.
[0100]
Normally, the movable guide member 74 is fixed by a lock mechanism (not shown) so that the guide surface 74A is positioned on an extension line of the fixed guide surface 72B in the paper width direction (see FIGS. 2, 3, 4 and the like).
[0101]
Then, as shown in FIG. 5, the movable guide member 74 can be rotated around the shaft 73 in the direction of arrow CW (clockwise direction in FIG. 5) by unlocking the lock mechanism. A large opening can be made upward between the guide surface 68 and the movable guide member 74.
[0102]
As shown in FIGS. 3 and 5 , the second paper feed roll 40 is used between the fixed guide surface 72 </ b> B and the second paper feed roll 40 and between the guide surface 74 </ b> B and the second paper feed roll 40. The transport path 75 guides the transported paper P toward the registration roll 30.
[0103]
As shown in FIGS. 2 and 4, a guide surface 76 is provided below the fixed guide surface 68. Between the fixed guide surface 68 and the guide surface 76 is a conveyance path 78 for the paper P, and the end of the conveyance path 78 on the arrow B direction side is connected to an opening 80 on the side surface of the apparatus.
[0104]
A pair of rollers 82 for transporting the paper P is provided in the middle of the transport path 78. The roller 82 is rotated by a motor (not shown) so that the paper P can be conveyed in the arrow B direction and the arrow F direction.
[0105]
Note that a paper reversing device (not shown) for reversing the paper P can be connected to the rear surface side (arrow B direction side) of the image forming apparatus 10. The sheet P that has been reversely conveyed in the conveyance path 75 by the reverse rotation of the sheet is guided to the sheet reversing apparatus, and the sheet P that is reversed and discharged by the sheet reversing apparatus is guided toward the conveyance path 75. .
(Paper detection mechanism)
As shown in FIG. 1, the upper guide assembly 58 is used to detect the paper P that has entered the transport path 69 and the first actuator 84 that is used to detect the paper P that has entered the transport path 65. The second actuator 86 is provided.
[0106]
The first actuator 84 is integrally provided with a shaft 84A, and the shaft 84A is rotatably inserted into a hole (not shown) of the upper guide assembly 58. For this reason, the first actuator 84 can swing around the shaft 84A as a rotation center.
[0107]
Here, the first actuator 84 is rotated clockwise as shown in FIG. 1 by a torsion spring (not shown) (one end is locked to the upper guide assembly 58 and the other end is locked to the first actuator 84, and the torsional force is strong). The side is normally in contact with the upper guide assembly 58 and is in the position shown in FIG.
[0108]
On the other hand, the second actuator 86 is a torsion spring (not shown) (one end is locked to the first actuator 84 and the other end is locked to the second actuator 86, and the torsional force is greater than that of the torsion spring of the first actuator 84. 1 is biased counterclockwise in FIG.
[0109]
The second actuator 86 is integrally formed with a protrusion 86A. In normal times, the protrusion 86A is in contact with the protrusion 84B formed integrally with the first actuator 84. It is in the position shown in FIG.
[0110]
A transmissive optical sensor 88 is provided on the fixed guide surface 68 on the main body frame side. The optical sensor 88 is connected to a control device 89 (see FIG. 2) for controlling the entire device.
[0111]
In the normal state, the second actuator 86 crosses the conveyance path 69 and the tip portion blocks the light beam of the optical sensor 88.
[0112]
When the paper P comes into contact with the second actuator 86 and the second actuator 86 rotates clockwise in FIG. 1 and the light beam of the optical sensor 88 is transmitted, it is detected that the paper P has entered the transport path 69. it can.
[0113]
Further, when the paper P comes into contact with the first actuator 84 and the first actuator 84 rotates counterclockwise in FIG. 1, the second actuator 86 together with the first actuator 84 rotates counterclockwise in FIG. And the light beam of the optical sensor 88 is transmitted, so that it can be detected that the paper P has entered the transport path 65.
(Function)
Next, the operation of the image forming apparatus 10 of this embodiment will be described.
[0114]
First, the conveyance of the paper P stacked on the first paper tray 34 will be described.
[0115]
As shown in FIG. 6, when the first paper feed roll 38 rotates in the direction of arrow CW, the uppermost paper P that contacts the outer peripheral surface of the first paper feed roll 38 is conveyed toward the conveyance path 65. .
[0116]
It should be noted that the first webbing member 42 (same as the 2nd webbing member 44) is formed of a material having a large friction with the paper P as in the past, and is based on the frictional force between the papers when the papers P overlap. Since the lower paper P is prevented from traveling by a large frictional force, only the upper paper P is conveyed.
[0117]
When the first paper feed roll 38 further rotates in the direction of arrow CW and the paper P enters the transport path 65, the leading edge is guided by the upper guide surface 62 (upper flat surface portion 62A and / or arc portion 62B). When the conveyance direction of P is changed obliquely downward, and the sheet P is further conveyed, the leading edge of the sheet P is guided by the lower guide surface 60 (second arc portion 60C), and the conveyance direction is changed obliquely upward, It is conveyed between the roll 30A and the roll 30B.
[0118]
Note that the first paper feed roll 38 stops after one rotation. Further, when the paper P enters the transport path 65, the first actuator 84 and the second actuator 86 rotate, and the light beam of the optical sensor 88 is transmitted, so that the paper P has entered the transport path 65. After a predetermined time has been detected (preset by the control device 89), the registration roll 30 rotates.
[0119]
The paper P sandwiched between the registration rolls 30 is further conveyed upward, and after a predetermined time has elapsed (preset by the control device 89), image writing is started. Then, the toner image on the image carrier 12 is transferred to the paper P, and the fixing device 24 fixes the toner image.
[0120]
Next, conveyance of the paper P stacked on the second paper tray 36 will be described.
[0121]
As shown in FIG. 7, when the second paper feed roll 40 rotates in the direction of arrow CW, the uppermost paper P that contacts the outer peripheral surface of the second paper feed roll 40 is transported toward the transport path 75. .
[0122]
When the second paper feed roll 40 further rotates in the direction of the arrow CW and the paper P is conveyed, the leading edge of the paper P is in the order of the fixed guide surface 72B, the guide surface 74B, the fixed guide surface 68, and the guide surface 64. Guided by contact and finally directed between rolls 30A and 30B.
[0123]
The second paper feed roll 40 stops after one rotation. When the paper P enters the transport path 69, the second actuator 86 rotates and the light beam of the optical sensor 88 is transmitted, so that it is detected that the paper P has entered the transport path 69, and a predetermined time has elapsed. Thereafter, the resist roll 30 rotates.
[0124]
The paper P sandwiched between the registration rolls 30 is further conveyed upward, the toner image on the image carrier 12 is transferred, and the toner image is fixed by the fixing device 24.
[0125]
Here, when a conveyance failure such as the paper P being jammed in front of the registration roll 30 due to some cause, the top plate 10A is opened, and the developing unit 27 is removed from the inside.
[0126]
Since there is a space after the developing unit 27 is removed above the resist roll 30, the upper guide assembly 58 can be easily operated from here.
[0127]
By rotating the upper guide assembly 58 in the direction of the arrow CCW (counterclockwise direction in FIG. 5) as shown in FIG. 5, the paper P near the registration roll 30 such as the transport path 65 and the transport path 69 is visually observed from above. This paper P can be easily removed. Since the toner sensor 90 is attached to the upper guide assembly 58 and retracts together with the upper guide assembly 58, the toner sensor 90 does not get in the way when the paper P is removed.
[0128]
Further, by rotating the movable guide member 74 in the arrow CW direction (clockwise direction in FIG. 5) as shown in FIG. 5, the paper P in the conveyance path 75 and the conveyance path 78 near the movable guide member 74 is viewed from above. The paper P can be easily removed.
[0129]
【The invention's effect】
As described above, since the image forming apparatus according to the first aspect has the above-described configuration, it has an excellent effect that it is possible to easily remove a sheet having a conveyance failure such as clogging before the registration roll.
[0130]
Since the image forming apparatus according to the second aspect has the above-described configuration, it has an excellent effect that the toner sensor does not interfere with the sheet removing operation.
[0131]
Since the image forming apparatus according to claim 3 has the above-described configuration, for example, the second and third paper trays are provided below the paper tray, and the sheets on the second and third paper trays are guided on the upper surface side. When the sheet reversing device for guiding to the member side or connecting the sheet reversing device for reversing the sheet to the image forming apparatus is connected, the sheet can be moved back and forth between the sheet reversing device and the upper surface side guide member . It has an excellent effect.
[0132]
Since the image forming apparatus according to the fourth aspect has the above-described configuration, it has an excellent effect that it is possible to easily remove a sheet having a conveyance failure in the vicinity of the second guide member.
[0133]
Since the image forming apparatus according to the fifth aspect has the above-described configuration, it is possible to easily change the position from the first position to the second position by rotating the upper guide member. Have
[0134]
Since the image forming apparatus according to claim 6 has the above-described configuration, it is possible to easily remove a sheet having a conveyance failure on the conveyance path of the second guide member located on the innermost side. Has an effect.
[Brief description of the drawings]
FIG. 1 is an enlarged cross-sectional view illustrating a main part of a sheet feeding device of an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention.
FIG. 3 is a side view showing the vicinity of an upper guide assembly of a paper feeding device of an image forming apparatus according to an embodiment of the present invention.
FIG. 4 is a schematic configuration diagram illustrating a sheet feeding device in a normal state.
FIG. 5 is a schematic configuration diagram illustrating a sheet feeding device in a maintenance state such as a paper jam.
FIG. 6 is a side view showing a main part of the paper feeding device showing a state in which the paper is started to be conveyed by the first paper feeding roll.
FIG. 7 is a side view showing a main part of the paper feeding device showing a state in which the second paper feeding roll starts to convey the paper.
FIG. 8 is a schematic diagram illustrating an example of a conventional image forming apparatus.
[Explanation of symbols]
10 Image forming apparatus
10A top plate (cover)
10B body side cover (body cover)
16 Image writing device (image forming unit)
18 Developing device (developing means)
27 Development unit (image forming unit)
30 Registration Roll 34 Paper Tray 36 Paper Tray 38 First Feed Roll 40 Second Feed Roll 58 Upper Guide Assembly ( Upper Guide Member )
74 Movable guide member (second guide member)
90 Toner sensor

Claims (6)

A paper tray for loading paper,
An image forming unit disposed above the paper tray and forming an image on the paper;
A paper feed roll that is provided inside the apparatus and feeds the paper in contact with the paper stored in the paper tray;
A registration roll disposed downstream of the paper feed roll in the paper transport direction and transporting the paper transported by the paper feed roll to the image forming unit;
An upper surface side guide member that is provided upstream of the registration roll in the paper conveyance direction and guides the upper surface side of the stacked paper;
A main body cover that houses the paper tray, the paper feed roll, the registration roll, and the upper surface side guide member, and that can be opened at least partially ;
With
At least a part of the image forming unit is provided to be removable from the inside of the apparatus through an opening part where at least a part of the main body cover is opened.
The upper surface side guide member is disposed so as to be visible from a space from which at least a part of the image forming unit is removed, and is operated from the space to guide the sheet, and the registration roll is operated from the space. An image forming apparatus, wherein the image forming apparatus is provided so as to be movable between a second position where the sheet conveying path upstream of the sheet conveying direction can be opened . The image forming unit includes at least an image carrier and a developing unit that forms a toner image by developing a latent image formed on the image carrier with toner,
The image forming apparatus according to claim 1, wherein the upper surface side guide member includes a toner sensor capable of detecting the presence or absence of toner in the developing unit. In the vicinity of the upper side guide member, the upper side guide according to claim 1 or claim paper entering from below the member, characterized in that a second guide member for guiding to the top-side guide member side 2 The image forming apparatus described in 1. The second guide member has a first position where the sheet can be guided and a sheet conveyance path which is operated from a space where at least a part of the image forming unit is removed and faces the second guide member. The image forming apparatus according to any one of claims 1 to 3, wherein the image forming apparatus is provided so as to be movable between a second position where the opening is possible. 5. The image forming apparatus according to claim 1, wherein the upper surface side guide member is provided to be rotatable about the registration roll as a rotation center. 6. 4. The part capable of opening the inside of the main body cover, the image forming unit, the upper surface side guide member, and the second guide member are arranged substantially in a straight line. 6. The image forming apparatus according to any one of items 5.

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