JP3706720B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile, and more particularly to an image forming apparatus having a sheet stacking unit having a registration adjusting mechanism.
[0002]
[Prior art]
In an image forming apparatus typified by a copying machine or an LBP, a plurality of sheets of a predetermined size (hereinafter often referred to as paper or paper) used for image formation are usually stored at positions according to the size. It has sheet stacking means (hereinafter often referred to as a paper cassette). The sheets loaded in the sheet cassette are separated and conveyed one by one by a predetermined separating device by a paper feeding operation of the image forming apparatus main body having an image forming unit therein, and by an image process of the image forming unit of the apparatus main body. A predetermined image is formed.
[0003]
For the separated and fed paper, the position of the front end of the paper in the paper transport unit is measured by the signal of the sensor of the transport unit such as a registration sensor, and the front end of the image formed on the photosensitive drum as the image carrier at a predetermined timing The image position in the paper transport direction (so-called leading edge registration) is controlled so as to be aligned with the position. For this reason, the so-called leading edge resist hardly causes a difference due to the paper size or the manufacturing error of the apparatus main body.
[0004]
On the other hand, a position in the direction perpendicular to or perpendicular to the sheet conveyance direction, that is, a position in the width direction (lateral registration) is a conveyance position of the separated and fed sheet and a photosensitive drum by a predetermined image forming unit. It is determined by the relative position with the image capture position of the image created above. For this reason, so-called lateral registration is affected by the accuracy of the paper transport position. The sheet conveyance position accuracy is affected in particular by the position accuracy of the sheet cassette with respect to the apparatus main body, and the horizontal image registration position is shifted as the cassette mounting position is shifted.
[0005]
For this reason, the mounting position of the paper cassette in the width direction is usually positioned by high-precision positioning means, including the paper stacking position.
[0006]
In order to solve this, as a general means, it is conceivable to adjust the mounting position of the sheet cassette at the time of assembly or for each apparatus in the market. FIG. 6 shows an example of a conventional image forming apparatus having a position-adjustable sheet cassette. The paper cassette 201 is provided with respect to the main body of the image forming apparatus so that it can be pulled out. The paper cassette 201 is engaged with the cassette rail frame 204 by pins 202 and 203. Since the front side pin 202 can be adjusted in the front-rear direction with respect to the apparatus main body, the sheet cassette 201 can be moved in the pull-out direction relative to the cassette rail frame 204, that is, in the front-rear direction with respect to the apparatus main body. Since the drawer direction of the cassette is orthogonal to or perpendicular to the sheet conveyance direction at the time of image formation, the position in the width direction during sheet conveyance can be adjusted by adjusting the position in the drawer direction of the cassette.
[0007]
[Problems to be solved by the invention]
In the above-described conventional image forming apparatus, when performing lateral registration adjustment for position adjustment in the width direction of the paper at the time of assembly or in the market, first, the cassette is pulled out, the screws 205 are loosened, and the image is placed at a predetermined position. After moving the pin position to come, it is necessary to fix the screw 205 again and store the cassette in the main body.
[0008]
However, in general, when such an adjustment process is added to the assembly process, the assembly efficiency is lowered, the product cost is increased, and the re-adjustment in the market is troublesome.
[0009]
In addition, since the amount of adjustment is manual, it is difficult to make fine adjustments in units of 0.1 mm. Repeated operations such as feeding a sheet, adjusting the cassette by pulling it out again, and transporting the sheet again. There was a case.
[0010]
The present invention has been made in view of the above-described prior art, and an object of the present invention is to make it possible to accurately adjust the position of a paper cassette in a short time with a simple configuration, An object of the present invention is to provide an image forming apparatus that reduces the error in the interval.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the first invention is a sheet stacking unit capable of stacking a plurality of sheets for image formation in the image forming unit and mounted so as to be drawable on the image forming apparatus main body. In order to relatively align the position in the width direction of the sheet conveyed from the sheet stacking unit and the position of image formation in the image forming unit, the sheet stacking position of the sheets stacked on the sheet stacking unit is In the image forming apparatus having a registration adjustment mechanism that adjusts the sheet stacked on the sheet stacking unit in a direction orthogonal to the sheet transport direction, the sheet stacking unit includes: a sheet transport direction of the sheet stacked on the sheet stacking unit; What withdrawable der in a direction orthogonal, rests movably in the drawing direction relative to the rail member retractably in the withdrawing direction of said sheet stacking means The registration adjustment mechanism is disposed in the pull-out direction front side of the rail member, said sheet stacking means is operated from the pull-out direction front side of the sheet stacking means in a state of being accommodated in the image forming apparatus main body The sheet stacking position is adjusted in a direction perpendicular to the sheet conveying direction, and the sheet stacking means is movably provided on a fixing member disposed in front of the rail member in the pull-out direction; A moving means for moving the adjustment member relative to the fixed member toward the front side or the back side in the drawing direction of the sheet stacking means, and an engagement member fixed to the adjustment member and engaged with the sheet stacking means. It is characterized by having .
[0012]
The second invention, the registration adjustment mechanism relates unwinding direction of the sheet stacking means, characterized in that it is arranged on the front side of the image forming apparatus body or said sheet stacking means.
[0015]
In a third invention, the adjustment member is a plate-like member, the fixing member is a stay disposed between a pair of rail members on the front side in the drawing direction, and the moving means is a screw member, The engaging member is an engaging pin that engages with a fitting hole formed in the sheet stacking unit.
[0016]
A fourth invention, the exterior member covering the front portion of the rail member is disposed in the drawing direction before the said rail member, said image forming apparatus wherein the screw member for the operation hole opened in the outer member The screw member is disposed inside the main body, and the screw member can be operated through the operation hole .
[0017]
According to a fifth aspect of the present invention, the operation hole of the exterior member can be concealed by a display plate that can be attached to and detached from the exterior member.
[0018]
According to a sixth aspect of the present invention, a plurality of sheets for forming an image in the image forming unit can be stacked, a sheet stacking unit that is detachably mounted on the main body of the image forming apparatus, and the sheet stacking unit conveys the sheet. In order to relatively match the position in the width direction of the sheet with the position of image formation in the image forming unit, the sheet stacking position of the sheets stacked on the sheet stacking unit is set to the sheet stacked on the sheet stacking unit. In the image forming apparatus having a registration adjusting mechanism that adjusts in a direction orthogonal to the sheet conveying direction, the sheet stacking unit can be pulled out in a direction orthogonal to the sheet conveying direction of the sheets stacked on the sheet stacking unit. The sheet stacking means is mounted so as to be movable in the pull-out direction with respect to a rail member that is movable in the pull-out direction of the sheet stacking means. The sheet stacking position is adjusted in the direction perpendicular to the sheet conveyance direction by serial sheet stacking means is operated from the pull-out direction front side of the sheet stacking means in a state of being accommodated in the image forming apparatus main body, the resist The adjustment mechanism includes a support member fixed to the image forming apparatus main body, a locking member movable in the pull-out direction with respect to the support member, and a moving unit that moves the locking member relative to the support member. has, in the sheet stacking means a state pushed into the image forming apparatus main body, for the locking member, the hook portion of the handle which is pivoted to the exterior member disposed in the drawing direction front side of the rail member It is locked.
[0019]
According to a seventh aspect of the present invention, the moving means of the locking member is a screw member, the support member has a substantially L-shaped cross section comprising a horizontal portion and an upright portion, and the locking member includes the horizontal portion and the horizontal portion. A substantially U-shaped cross section consisting of upright portions standing upright on the front side and the back side of the screw member, and screwing the screw portion of the screw member into the screw hole of one upright portion of the locking member, and the tip of the screw member The support portion is supported by the upright portion of the support member so as to be rotatable and non-movable in the axial direction, and the hook portion of the handle can be engaged with the other upright portion of the locking member.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
1 to 3 show a first embodiment of the present invention, where 100 is an apparatus main body, 101 is a paper cassette as a sheet stacking means, and the paper cassette 101 is attached to the apparatus main body 100 by a cassette rail 102. It is provided so that it can be pulled out.
[0021]
The image forming apparatus main body 100 accommodates an image forming unit similar to the conventional one. An example of an electrophotographic image forming unit will be described. Sheets of different sizes are stacked and stored in a plurality of front loading type paper feed cassettes as described above, and are selectively fed.
[0022]
That is, the sheets stacked and stored in each paper feed cassette 101 are sequentially fed out from the uppermost sheet by a paper feed roller as a feeding means provided corresponding to each paper feed cassette. Then, the sheet fed by the sheet feeding roller is separated by the pair of separation rollers as the separating means, and only the uppermost sheet is separated and sent to the pair of registration rollers in the rotation stopped state via the pair of conveying rollers.
[0023]
The conveying roller pair conveys the sheet until the leading end of the sheet hits the nip of the registration roller pair to form a predetermined amount of loop, and the skew state of the sheet is corrected by the formation of the loop.
[0024]
On the other hand, an electrostatic latent image is formed on a photosensitive drum as an image carrier by a laser beam that is charged by a primary charging unit and then modulated in accordance with image information. The latent image is formed by toner as a developer. Developed as a toner image. The skew-corrected sheet is transferred between the photosensitive drum and a transfer means such as a roller by a pair of registration rollers that start grip rotation at the timing of aligning the position of the toner image on the photosensitive drum and the leading edge of the sheet. The toner image on the photosensitive drum is sequentially transferred onto the sheet surface by the transfer means while passing through the transfer portion.
[0025]
The sheet having been subjected to transfer of the toner image is sent by the transfer means such as a belt to a constant Chakushudan such fixing roller, where the transferred toner image is heated and fixed to the sheet surface. The sheet after the toner image fixing process is discharged onto a discharge tray outside the apparatus by a discharge roller. In the paper cassette 101, 103 and 103 ′ are paper width regulating plates which are regulating members for regulating the paper width position, and 104 is movable in a direction perpendicular to the cassette drawing direction, and serves as a regulating means for regulating the paper trailing edge position. The paper trailing edge regulating plate 105 is a paper stacking plate for loading paper, and the paper is stacked inside the three regulating plates 103, 103 ′, 104 and on the paper stacking plate 105.
[0026]
106 and 106 'are inner rail members, 107 and 107' are outer rail members, 108 is an outer cover that is fixed to the inner rail members 106 and 106 'and covers the front portion of the cassette, and 109 is an inner rail member 106 and 106. ′ Is a front stay fixed to the front side in the pulling direction, and 110 is a back stay fixed to the inner rail members 106, 106 ′ in the pulling direction back side. Therefore, the inner rail members 106 and 106 ', the cassette front cover 108, the front stay 109, and the back stay 101 are integrated and slide with respect to the outer rail members 107 and 107', and the device main body is not shown in the figure. The mechanism is always fixed at the same position when stored.
[0027]
111 and 112 are first and second engagement pins provided on the front stay 109 and the back stay 110, respectively, 113 is an adjustment support plate, the first engagement pin 111 is connected to the adjustment support plate 113, and the second The engaging pin 112 is fixed to the back stay 110. These engaging pins 111 and 112 are respectively engaged with the fitting holes 120 and the long holes 121 provided in the paper cassette 101, whereby the paper cassette is positioned at a predetermined position with respect to the cassette rail frame 102.
[0028]
FIG. 3 shows a cross-sectional view of the adjustment mechanism. The adjustment support plate 113 to which the pin 111 is fixed has a substantially L shape including a horizontal portion 113a and a hanging portion 11b. The horizontal portion 113a is slidably mounted on the upper surface of the front stay 109, and the hanging portion 113b is formed. It is attached so as to protrude downward from the hole 114 of the front stay 109. The adjustment support plate 113 is guided in the hole 114, but other guide means may be provided. Reference numeral 115 denotes a screw hole provided in the hanging portion 113b protruding from the hole 114 and a screw provided in the front stay 109 and penetrating through a round hole located opposite to the screw hole, such as a snap ring. The holding members 116 and 116 'are supported by the front stay 109 so as to be rotatable and immovable in the axial direction.
[0029]
Reference numeral 117 denotes a compression spring. One end is in contact with one end 113b of the adjustment support plate 113 and the other end is in contact with the front stay 109. The adjustment support plate 113 is always in front of the front stay 109, that is, in front of the cassette withdrawing direction. It is attached so as to urge.
[0030]
Therefore, even if the screw 115 is rotated, the axial position of the screw 115 itself does not move, and only the pin 111 and the adjustment support plate 113 move in the front-rear direction with respect to the front stay. Reference numeral 118 denotes an operation hole provided on the front cover on the same axis as the screw, and its diameter is such that an adjustment tool such as a screwdriver can pass therethrough.
[0031]
Therefore, when adjusting the lateral resist, a screwdriver is inserted through the hole 118 of the outer cover 108 and the screw 115 is rotated. In this embodiment, when the screw 115 is rotated clockwise, the pin 111 moves to the near side, and when rotated counterclockwise, the pin 111 moves to the far side. As a result, the sheet cassette 101 also moves to the near side or the far side in the cassette drawing direction with respect to the apparatus main body, and the lateral registration adjustment can be performed.
[0032]
Further, since the amount to be adjusted is one pitch of the screw every time the screw 115 is rotated, if the screw portion is M6, it moves by 1 mm per one rotation. In other words, if it is desired to move it 0.5 mm forward, the screw 115 can be turned in a half-turn clockwise direction, so that fine adjustment can be easily performed.
[0033]
In the present embodiment, the location where the hole 118 is opened coincides with the mounting portion 108a of the size display plate 119 as shown in FIG. 2, and therefore the size plate can be inserted through the insertion hole 108b. The hole 118 has a structure that cannot be seen in appearance. Other plates can be used instead of the display plate. Further, in the present embodiment, the lateral registration adjustment can be performed from the front side of the apparatus main body, which is the front side of the cassette drawing direction, so that the trouble of pulling out the cassette each time the registration adjustment is performed is also eliminated.
[0034]
(Second Embodiment)
Next, a second embodiment will be described. 4 and 5 show a second embodiment of the present invention. Components having the same functions as those shown in the first embodiment are denoted by the same reference numerals. Unlike the first embodiment, the adjustment mechanism is provided on the apparatus main body side. In the second embodiment, the pins 111 can be directly fixed to the front stay 109 so that the paper cassette 101 does not move with respect to the cassette frame 102 both in the front-rear direction and in the left-right direction.
[0035]
Reference numeral 151 denotes a handle having a hook portion 151 a for engaging with the apparatus main body, and is rotatably attached to the cassette side, for example, the exterior cover 108. Reference numeral 152 denotes a return spring, one end of which is hooked to the handle operating portion 151b and the other end is hooked to the cassette front cover 108, and urges the handle 115 to always rotate counterclockwise.
[0036]
The registration adjusting mechanism has a locking plate 153 as a substantially U-shaped locking member and a support plate as a support member fixed to the apparatus main body, and one end portion 153a of the locking plate is a hook portion of the handle 151. 151a is engaged with the main body of the apparatus. The locking plate 153 is supported and guided by the support plate by engaging a headed pin 153 fixed to the plate with a guide groove (not shown) of the support plate 154.
[0037]
Therefore, when the paper cassette is pushed into the apparatus main body, the cassette is urged to the front side in the pulling direction by an urging means (not shown), and the hook portion 151a of the handle is locked to the locking plate. May hold the operating portion 151b of the handle 151 and rotate the handle 151 clockwise.
[0038]
115 penetrates through a screw hole provided in the other end portion 153b of the locking plate 153 and a round hole located opposite to the screw hole provided in the support plate 154 as a support member protruding from the apparatus main body. A screw to be attached and supported by the support plate 154 by holding members 116 and 116 '. Reference numeral 117 denotes a compression spring. One end is in contact with one end 153b of the locking plate 153 and the other end is in contact with the support plate 154, and is attached so as to always urge the locking plate 153 forward with respect to the support plate 154. ing. Therefore, even if the screw 115 is rotated, the position of the screw 115 itself does not move, and only the locking plate 153 moves in the front-rear direction with respect to the apparatus main body.
[0039]
These registration adjusting mechanisms are located near the upper part of the exterior cover 108, and the screw axis is in a position where it can be seen from the front side of the apparatus main body. For example, in FIG. 5, the registration adjusting mechanism is arranged in a clearance 155 with the upper cassette front cover 108. Yes.
[0040]
Therefore, when adjusting the lateral registration, the lateral registration can be adjusted as in the first embodiment by inserting a screwdriver through the gap 155 and rotating the screw 115. Further, since the amount to be adjusted is the same as that in the first embodiment, it can be easily finely adjusted.
[0041]
In each of the above embodiments, a screw may be formed at the tip of the screw member, and the head side may be a smooth surface.
[0042]
【The invention's effect】
As described above, according to the present invention, in the image forming apparatus in which the sheet stacking unit is provided so as to be able to be pulled out from the image forming apparatus main body, the registration adjusting mechanism that adjusts the lateral position perpendicular to the sheet conveying direction is provided. Since the sheet stacking unit is mounted on the image forming apparatus main body, the sheet stacking unit is operated from the front side in the pulling direction of the sheet stacking unit, so that adjustment can be performed from the front side of the image forming apparatus main body. Adjustment can be easily performed.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of an image forming apparatus according to the present invention. FIG. 2 is an exploded perspective view of a cassette portion of the embodiment of the image forming apparatus according to the present invention. FIG. 4 is a perspective view showing another embodiment of the image forming apparatus according to the present invention. FIG. 5 is a cassette section of another embodiment of the image forming apparatus according to the present invention. FIG. 6 is an exploded perspective view of a cassette portion of a conventional image forming apparatus.
100 ... Main body 101 ... Paper cassette (sheet stacking means)
106, 106 ', 107, 107' ... rail 108 ... exterior member 111, 112 ... pin 113 ... adjustment support plate 115 ... screw member 116, 116 '... holding member 117 ... spring 118 ... operation hole 151 ... handle 152 ... return Spring 153 ... locking plate (locking member)
154 ... Support plate (support member)

Claims (7)

A sheet stacking unit capable of stacking a plurality of sheets for image formation in the image forming unit and mounted so as to be able to be pulled out to the image forming apparatus main body;
In order to relatively align the position in the width direction of the sheet conveyed from the sheet stacking unit and the position of image formation in the image forming unit, the sheet stacking position of the sheets stacked on the sheet stacking unit is In an image forming apparatus having a registration adjustment mechanism that adjusts a sheet stacked on a sheet stacking unit in a direction orthogonal to the sheet conveyance direction of the sheet,
Said sheet stacking means, the I drawable der in the direction perpendicular to the sheet conveying direction of the stacked sheets on the sheet stacking means, the pull-out direction relative to the advance and retreat of the rail member in the unwinding direction of the sheet stacking means Is movably mounted on the
The registration adjusting mechanism is disposed on the front side in the pull-out direction of the rail member , and is operated from the front side in the pull-out direction of the sheet stacking unit in a state where the sheet stacking unit is stored in the image forming apparatus main body . the sheet stacking position is adjusted in the direction perpendicular to the sheet conveyance direction by Rukoto,
The registration adjusting mechanism includes: an adjustment member that is movably provided on a fixing member that is disposed in front of the rail member in the pull-out direction; and the adjustment member that is on the near side in the pull-out direction of the sheet stacking unit with respect to the fixing member. An image forming apparatus comprising: a moving unit that relatively moves to the back side; and an engaging member that is fixed to the adjustment member and engages with the sheet stacking unit .   The image forming apparatus according to claim 1, wherein the registration adjusting mechanism is arranged on the front side of the image forming apparatus main body or the sheet stacking unit with respect to a drawing direction of the sheet stacking unit. In Claim 1 , the said adjustment member is a plate-shaped member, the said fixing member is a stay arrange | positioned between a pair of rail members in the drawing direction near side, The said moving means is a screw member, The image forming apparatus according to claim 1, wherein the engaging member is an engaging pin that engages with a fitting hole formed in the sheet stacking unit. According to claim 3, wherein the exterior member covering the front of the withdrawing direction before the rail member of the rail member is disposed, the image forming apparatus main body wherein the threaded member for the operation hole opened in the outer member An image forming apparatus, wherein the screw member can be operated through the operation hole . 5. The image forming apparatus according to claim 4 , wherein the operation hole of the exterior member can be concealed by a display plate detachable from the exterior member. A sheet stacking unit capable of stacking a plurality of sheets for image formation in the image forming unit and mounted so as to be able to be pulled out to the image forming apparatus main body;
In order to relatively align the position in the width direction of the sheet conveyed from the sheet stacking unit and the position of image formation in the image forming unit, the sheet stacking position of the sheets stacked on the sheet stacking unit is In an image forming apparatus having a registration adjustment mechanism that adjusts a sheet stacked on a sheet stacking unit in a direction orthogonal to the sheet conveyance direction of the sheet,
The sheet stacking means can be pulled out in a direction perpendicular to the sheet conveying direction of the sheets stacked on the sheet stacking means, and can be pulled out in the pulling direction with respect to a rail member that is movable back and forth in the pulling direction of the sheet stacking means. It is placed so that it can move,
The registration adjusting mechanism is configured to operate the sheet stacking position in a direction orthogonal to the sheet conveying direction by being operated from the front side in the pulling-out direction of the sheet stacking unit in a state where the sheet stacking unit is housed in the image forming apparatus main body. Adjust to
The registration adjusting mechanism includes a support member fixed to the image forming apparatus main body, a locking member movable in the pull-out direction with respect to the support member, and a moving unit that moves the locking member relative to the support member. has the door, in the sheet stacking means a state pushed into the image forming apparatus main body, for the locking member, the handle which is pivoted to the exterior member disposed in the drawing direction front side of the rail member An image forming apparatus, wherein a hook portion is locked. 7. The moving member of the locking member according to claim 6 , wherein the moving member is a screw member, the support member has a substantially L-shaped cross section including a horizontal portion and an upright portion, and the locking member includes the horizontal portion and the horizontal portion. It has a substantially U-shaped cross section consisting of upright portions that stand upright on the front side and the back side, and the screw portion of the screw member is screwed into the screw hole of one upright portion of the locking member, and the tip end portion of the screw member The image forming apparatus is characterized in that the upright portion of the support member is supported rotatably and axially non-movable, and the hook portion of the handle can be engaged with the other upright portion of the locking member.

Images