JP2008222380A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further accurately arrange a positional relationship between a paper feed roller and a bottom plate for transferring a sheet in a manual insertion tray to the paper feed roller. <P>SOLUTION: A device body 1a of an image forming device 1 is provided with the paper feed roller 9 for the manual insertion tray for feeding sheets to a carrier path, and a recess 1c which is a mounting part of a guide unit 41 is formed between the paper feed roller 9 and a paper feed cassette 2. A guide plate 46 of a swing member 43 is supported to the guide unit 41 disposed in the recess 1c so as to be liftable. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus provided with a manual feed tray used in a printing machine, a copying machine, a facsimile machine, and a composite machine thereof.

Many image forming apparatuses such as printers, copiers, and facsimiles are equipped with a manual feed tray on the side of the machine body, and the manual feed tray is a special size that is not accommodated in the paper feed cassette inside the machine body. This is used in the case of using papers having color or papers having colors.
FIG. 17 is a schematic cross-sectional view of a conventional manual feed tray. As shown in the drawing, a guide plate 102 is provided on the manual feed tray 101, and a sheet 104 is placed on the guide plate 102. A spring 103 that urges the sheet 104 upward is disposed between the manual feed tray 101 and the guide plate 102, a rotation shaft is provided at an end of the guide plate 102 on the side (not shown), and the guide plate 102 is It is rotatably supported. A separation pad 105 and a paper feed roller 106 are disposed on the leading end side of the guide plate 102. The separation pad 105 and the paper feed roller 106 are attached to the apparatus main body side of the image forming apparatus.
The separation pad 105 can press the separation pad 105 against the paper feed roller 106 by the urging force of the spring 108, and the pad 109 disposed on the upper surface of the separation pad 105 presses the paper feed roller 106. The paper feed roller 106 rotatably supports the paper feed roller 106 with the rotation shaft 110 as the center of rotation. Further, the leading end portion of the sheet 104 is in contact with the roller surface of the paper feed roller 106 by the pressing force of the spring 103.

With such a configuration, when printing a sheet using the manual feed tray 101, the sheet feeding roller 106 is rotated by a driving unit (not shown) after a print command. The sheet is transferred in the rotation direction of the paper feed roller 106 by the pressure contact with the paper feed roller 106 and the frictional force. At this time, when two sheets 104 are fed between the sheet feeding roller 106 and the separation pad 105, the lower sheet 104 is applied to the pad 109 by the frictional force of the pad 109 of the separation pad 105. Further transfer of the contacted sheet is restricted, and only the sheet 104 on the side in contact with the sheet feeding roller 106 is transferred to the conveyance path in the image forming apparatus (see Patent Document 1).
JP 2002-308451 A

Many manual feed trays are formed such that the manual feed tray itself can be freely opened and closed on the side surface of the main body of the image forming apparatus. In addition, as described above, the manual feed tray is provided with a guide plate, and the guide plate is in the lowered position in the printing standby state. During printing, the guide plate is raised and the sheet is pressed against the paper feed roller. There is a type of thing to be done.
In this type of image forming apparatus, a manual feed tray is a movable body that can be freely opened and closed, and a guide plate is attached to the movable body. Therefore, a paper feed roller disposed on the guide plate and the apparatus main body side. There is a limit to accurately arranging the positional relationship with. In addition, if the manual feed tray is provided with a guide plate and a guide plate lifting mechanism, the weight of the manual feed tray increases, and the manual feed tray cannot be opened and closed smoothly. Furthermore, since the manual feed tray and the guide plate are integrated, the shape of the manual tray mounting part that is equipped with the guide plate lifting mechanism is complicated and large, or after the lifting mechanism is attached to the manual tray, the main body of the device There is a problem that the manual feed tray must be attached to the side, and the degree of freedom in layout and the simplification of attachment are lacking.

  The present invention has been made in view of such circumstances, and more accurately arranges the positional relationship between a guide plate for transferring a sheet placed on a manual feed tray to a paper feed roller and the paper feed roller. Another object of the present invention is to provide an image forming apparatus that can smoothly open and close the manual feed tray.

In order to achieve the above object, the present invention provides a manual feed tray that is openable and closable with respect to the apparatus main body and a sheet that is rotatably supported on the apparatus main body side and is placed on the manual feed tray. A sheet feed roller that feeds the sheet, a guide plate that can be moved up and down to move the leading end of the sheet to the height of the sheet feed roller when feeding the sheet to the conveyance path, and an outer peripheral surface of the sheet feed roller In the image forming apparatus provided with the separator that press-contacts the image forming apparatus, a guide unit that supports the guide plate so as to be movable up and down is provided, and the guide unit is configured to correspond to the leading end position of the sheet placed on the manual feed tray. The guide unit is mounted in a non-engaged state with respect to the manual feed tray.
In the image forming apparatus, the guide unit can support the separator.
In the image forming apparatus, the mechanism for raising and lowering the guide plate includes a swingable lever member and a cam member that contacts the lever member, and the lever member engages with the guide plate, A spring mounting in which a follower that contacts the cam member and raises the push-up restriction arm by rotation of the cam member and a first spring (a tension spring) that pushes the guide plate to the lowered position by the push-up restriction arm A second spring (compression spring) that biases the guide plate upward, and the first spring force can be increased to the second spring force. .
In the image forming apparatus, the cam member on which the follower slides has an outer peripheral contour on which the lift restricting arm is lifted, and the push restricting arm releases the engagement state with the guide plate. A mating release area and a lowering area for moving the push-up restricting arm to the lowering position can be provided.

The image forming apparatus of the present invention is a manual feed tray that is openable and closable with respect to the apparatus main body, and is rotatably supported on the apparatus main body side, and feeds a sheet placed on the manual feed tray to a conveyance path of the apparatus main body. A sheet feed roller, a guide plate capable of moving up and down to move the leading end of the sheet to the height of the sheet feed roller when feeding the sheet to the conveyance path, and a separator that presses the outer peripheral surface of the sheet feed roller An image forming apparatus provided with a guide unit that supports the guide plate so that the guide plate can be moved up and down, and the guide unit is fixed to the apparatus main body corresponding to the leading end position of the sheet placed on the manual feed tray. Since the guide unit is mounted in a non-engaged state with respect to the manual feed tray, unlike the conventional case where the guide unit is disposed on the manual feed tray, an installation error is caused. Decreases, the accuracy of the distribution feeding position to the sheet feeding roller is increased.
In the image forming apparatus, since the separator is supported by the guide unit, the arrangement relationship between the guide unit and the separator can be accurately arranged, and the functionality of the separator can be improved.
In the image forming apparatus, the mechanism for raising and lowering the guide plate includes a swingable lever member and a cam member that contacts the lever member, and the lever member engages with the guide plate. A follower that abuts the cam member and raises the push-up restricting arm by rotation of the cam member; and a spring attaching portion to which the push-up restricting arm urges the guide plate to the lowered position. The guide plate is provided with a second spring that urges the guide plate upward, and the first spring force is increased to increase the second spring force. By using the difference in spring force between the second spring and the second spring, the swing control of the push-up restricting arm is facilitated.
Further, in the image forming apparatus, the cam member on which the driven portion slides has an outer peripheral contour that lifts the push-up restricting arm, and the push-up restricting arm releases the engagement state with the guide plate. Since the engagement release region to be moved and the lowering region for moving the push-up restricting arm to the lowered position are provided, the push-up restricting arm can be easily swung.

Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. In this specification, the direction indicated by the arrow F in FIG. 1 is the front side of the apparatus.
FIG. 1 is a perspective view of an image forming apparatus as a printing apparatus of the present invention, and FIG. 2 is a cross-sectional view of the image forming apparatus as viewed from the side of the image forming apparatus.
An image forming apparatus 1 shown in FIG. 1 is provided with a paper feed cassette 2 as a paper feed unit that accommodates sheets as print media on the lower side of the apparatus main body 1a, and as shown in FIG. A pickup roller 3 for pulling out the sheet from the sheet feeding cassette 2 and a sheet feeding roller 4 and a separating roller 5 disposed in a pair on the upstream side are provided on the discharge port side. On the front surface of the apparatus main body 1a, the manual feed tray 8 can be opened in the direction indicated by the arrow Y about the rotation shaft 8a. A paper feed roller 9 is disposed on the lower end side of the manual feed tray 8. When a sheet is set on the manual feed tray 8, the sheet can be transferred to the conveyance path 7 on the downstream side by the rotation of the paper feed roller 9.

The structure of the image forming apparatus 1 will be briefly described along the flow of the sheet. The above-described conveyance path 7 is formed on the downstream side of the paper feed rollers 4 and 9. In the conveyance path 7, the first feed roller pair 10, the registration roller pair 11, the driving roller 12 and the secondary transfer roller 13, the fixing roller 15 of the fixing unit 14, and the pressure roller from the paper feed roller 4 toward the downstream side. 16, a second feed roller pair 17 and a discharge roller pair 18 are disposed. By these roller groups 10 to 18, the sheet is discharged from the discharge port 19 through the conveyance path 7.
A drive roller 12 that is paired with the secondary transfer roller 13 is provided with a driven roller 21 that is spaced apart from the horizontal direction of the drive roller 12. A transfer belt is provided between the drive roller 12 and the driven roller 21. 22 is disposed. Primary transfer rollers 28 to 31 are arranged at intervals on the inner peripheral side of the transfer belt 22, and an image forming unit is positioned below the transfer belt 22 at a position corresponding to each primary transfer roller 28 to 31. 24-27 are arranged.

  These image forming units 24 to 27 are substantially the same, and only the ink colors supplied at the time of printing are different. In other words, yellow (Y), magenta (M), cyan (C), and black (K) process units are provided along the circumferential direction (counterclockwise direction) A of the transfer belt 22. Each process unit (A, M, C, K) has the same basic configuration except for the toner color. Therefore, here, the yellow (M) image forming unit 24 located on the upstream side will be described in detail, and the other toner color image forming units 25 to 27 will be omitted from the description for simplification of the drawings. Is omitted.

  The image forming unit 24 includes drum units 32 to 34 and a developing unit 35, and the drum units 32 to 34 include a photosensitive drum 32, a cleaning unit 33, and a charger 34 as a charging unit. Among these, the photosensitive drum 32 is rotatably provided in the clockwise direction. Around the photosensitive drum 32, a cleaning unit 33, a charger 34, and a developing unit 35 are arranged in the order of rotation of the photosensitive drum 32. It is arranged along. The charger 34 has a function of uniformly charging the outer peripheral surface of the photosensitive drum 32 to a predetermined surface potential. A surface region between the charger 34 and the developing unit 35 is an irradiation region of the light beam from the exposure unit 36, and the photosensitive drum 32 is exposed by the light beam, and an image signal is transferred onto the photosensitive drum 32. An electrostatic latent image corresponding to is formed.

The electrostatic latent image formed in this way is visualized by the toner supplied from the developing unit 35 via the toner cartridge 37 and transferred to the transfer belt 22 by the primary transfer roller 28. The same processing is performed in the downstream image forming units 25 to 27, and the toner image transferred to the transfer belt 22 is transferred to the sheet by the pressure contact of the transfer belt 22 of the secondary transfer roller 13 in the transfer portion. The
When the unfixed toner image transferred to the sheet passes through the fixing roller 15 of the fixing unit 14, it is fixed to the sheet by the heat of the fixing roller 15 and the pressure of the pressure roller 16, and is distributed from the discharge port 19. Established. On the other hand, in the photosensitive drum 32, residual toner attached to the photosensitive drum 32 is removed by the cleaning unit 33.
2 is a reverse conveyance path 38 for duplex printing, and the front cover 39 of the apparatus main body 1a is a reverse conveyance path for the double-sided printing. 38 can be opened to the arrow Y side along with the manual feed tray 8 with the rotation shaft 39b as the center of rotation, with 38 as a boundary.

3 shows the manual feed tray 8 with the front cover 39 of the image forming apparatus 1 removed, and FIG. 4 shows the state with the manual feed tray 8 of FIG. 3 removed.
The manual feed tray 8 is provided with support shafts 8a (only one is shown in the drawing) on both the left and right sides of the manual feed tray 8, and the support shaft 8a has both left and right side surfaces 39a of the front cover 39 (only one side is shown in FIG. 1). ) Is supported by a support portion such as a support hole formed in a rotatable manner. A sheet can be placed on the upper surface side of the manual feed tray 8. As shown in FIG. 4, between the paper feed cassette 2 and the roller support unit 66 provided with the paper feed roller 9 above the paper feed cassette 2, that is, the base end side of the manual feed tray 8 (support shaft). A recess 1c that is long in the lateral direction is provided so as to correspond to the portion on which 8a side) is disposed. A space in which the guide unit 41 is mounted is provided in the recess 1c. As shown in FIG. 5, the guide unit 41 is fixed to the left and right side frames 45a and 45b of the apparatus main body 1a, and one end side is a screw mounting portion 45c (see FIG. 4) formed on the left side frame (as viewed from the apparatus main body) 45b. The screw 70 is attached. Moreover, the other end side of the guide unit 41 is inserted and attached to the attachment part (assembly part) formed in the right side part frame 45a. Note that there is no portion that engages with the manual feed tray 8 for attachment to the guide unit 41.

FIG. 6 is a perspective view of the guide unit 41 as viewed from obliquely above, and FIGS. 7 and 8 are perspective views of the guide unit 41 as viewed from obliquely above in another direction. A paper feed roller 9 is also shown.
With reference to these drawings, the guide unit 41 has a swing member 43 and a separator 44 assembled to a casing 42 of the guide unit 41. Among these members, the swing member 43 plays a role of raising the leading end portion of the sheet placed on the manual feed tray 8 to the height position of the paper feed roller 9 by a lifting mechanism described later. 6 and 7 show a state in which the swing member 43 is in the lowered position (initial state), and FIG. 8 shows a state in which the swing member 43 is in the raised position.

The swing member 43 is provided with a guide plate 46 that is long in the left-right direction, and mounting pieces 47 that are bent in a direction perpendicular to the surface of the guide plate 46 are formed on both left and right sides of the guide plate 46. The attachment piece 47 is rotatably supported by a shaft member 49 attached to side walls 48 formed on the left and right side portions of the casing 42. A regulating piece 46a (see FIG. 9) is formed at one end of the guide plate 46 of the swing member 43 so as to protrude rearward and downwardly from the guide plate 46.
An elevating mechanism 50 that pushes up the guide plate 46 of the swing member 43 is disposed on one side of the guide unit 41. The elevating mechanism 50 is provided with a lever 51 that pushes up the swing member 43 and a cam 57 that operates the lever 51.

As shown in FIGS. 10 and 11, the lever 51 is formed with a shaft hole 51 a, and the shaft hole 51 a is rotated by a shaft portion 56 (see FIGS. 7 and 8) formed in the side wall 48 of the casing 42. Supported as possible. In an initial state (approximately the state shown in FIG. 10) where the lever 51 is not operated, a push-up restricting arm 52 extending forward, a spring mounting arm 53 extending backward, and a cam follower arm 54 extending downward are formed. . The push-up restricting arm 52 is formed of a thick part 52a and a thin part 52b, and the upper surface of the tip part 52c inclined slightly below the thin part 52b swings as shown in FIGS. It arrange | positions so that the upper surface of the control piece 46a formed in the guide plate 46 of the member 43 may be contact | abutted.
With reference to FIG. 11 or FIG. 12, the flat spring mounting arm 53 is formed with a hooking hole 53a for the tension spring 55 on the front end (rear end) side. One end of a tension spring 55 is attached to the hook hole 53 a, and the other end of the tension spring 55 is attached to a hook support portion 41 a of the tension spring 55 formed near the side wall 48 of the guide unit 41.
The cam driven arm 54 forms a driven portion 54 a having a curved surface on the tip (lower end) side, and the driven portion 54 a is formed to protrude from the outer surface of the cam driven arm 54 to the outside of the apparatus main body 1 a. It is arranged to be located on the orbit.

  As shown in FIGS. 7 and 8, a substantially semi-circular plate-like cam 57 is provided below the driven portion 54a of the lever 51, and a rotating shaft 57a is provided on the cam 57. It is rotatably supported by a support portion (not shown). In the lever 51 and the cam 57, the driven portion 54 a of the lever 51 contacts the outer peripheral surface 57 b of the cam 57. In the state shown in FIG. 7, the rotation angle of the cam 57 is the 0 degree position, and the initial position of the cam 57 is shown. At this initial position, the guide plate 46 of the swing member 43 is disposed at the lowered position (hereinafter referred to as the default position). In the state shown in FIG. 8, the rotation angle of the cam 57 is a position rotated approximately 180 degrees. At this position, the guide plate 46 of the swing member 43 is disposed at the raised position.

  A pair of left and right compression springs 59 are provided at the bottom of the swing member 43, and one end (upper end) portion is supported on the lower surface of the guide plate 46 of the swing member 43. The other end (lower end) portion is supported by the bottom plate 42 a of the casing 42. The compression spring 59 always acts to urge the guide plate 46 upward by elastic force. Regarding the spring force of one tension spring 55 and the spring force of the compression spring 59, the spring force of the tension spring 55 is made larger than the spring force of the pair of compression springs 59 combined. Thus, in a state where no external force is applied to the lever 51, the guide plate 46 of the swing member 43 is urged toward the bottom plate 42a of the casing 42 against the spring force of the compression spring 59.

  The outer peripheral surface 57b of the cam 57 includes an ascending region a, a disengagement region b, and a descending region c like the cam 57 shown in the lower left of FIG. The cam 57 rotates counterclockwise about the rotation shaft 57a, and in the curved rising region a, the cam 57 contacts the driven portion 54a of the lever 51 to rotate the lever 51 in the clockwise direction. Thus, the cam 57 can be raised by rotating the tip end portion 52c of the push-up restricting arm 52 of the lever 51 upward. As the push-up restricting arm 52 rotates, the tip 52c rises, so that the compression spring 59 urges the guide plate 46 of the swing member 43 upward, and the guide plate 46 can be raised. . In this state, since the movement of the spring attachment portion 53 to which the tension spring 55 is attached is restricted by the cam 57, the spring force of the tension spring 55 is not transmitted to the swing member 43 side.

As shown in FIG. 8, in the disengagement region b of the cam 57, the driven portion 54 a slides on the substantially semicircular outer peripheral surface, so that the distal end portion of the push-up restricting arm 52 remains while the lever 51 is raised. 52c can be fixed substantially at the raised position. At the ascending position of the leading end 52c, the sheet height position on the guide plate 46 can be maintained at the sheet feeding height of the sheet feeding roller 9.
The descending region c of the cam 57 has a substantially linear shape, and the lever 51 is rotated counterclockwise (inverted) when the follower 54a slides. In this state, when the rotation direction of the spring attachment portion 53 to which the tension spring 55 is attached is reversed, the push-up restricting arm 52 of the lever 51 is lowered, and the guide plate 46 of the swing member 43 is lowered. At this time, the guide plate 46 of the swing member 43 is lowered by the spring force of the tension spring 55 and pushed down to the default position.

  A separator 44 shown in FIG. 13 is attached to the guide unit 41. The separator 44 is provided with a support base 62 and a separator body 63. Left and right side walls 62d are provided on both left and right sides of the support base 62 so as to stand upright from the bottom plate 42a of the guide unit 41, and a base 62c is provided at an intermediate position between the side walls 62d. A cylindrical screw mounting portion 62a is provided at the lower portion. The support base 62 is provided with a boss-shaped screw attachment portion 62 a and is attached to the bottom plate 42 a of the guide unit 41 by a screw 69. On both side walls 62d of the support base 62, slits 62b extending in the vertical direction are formed. A leg portion 63b formed at the lower portion of the base 63a of the separator main body 63 is assembled to the slit 62b so as to be slidable in the vertical direction. A pad 63c is attached to the upper surface of the base 63a. A spring 64 is disposed in a compressed state between the base 63 a and the support base 62.

The support structure of the paper feed roller 9 will be described with reference to FIG.
The paper feed roller 9 is disposed inside the roller support unit 66, one end is supported by a shaft portion 66 b that protrudes in the horizontal direction from a support wall 66 a that is disposed at one end in the vertical direction, and the other end is a gear 67. Is connected to a rotatable drive shaft 68 by a drive means (not shown). Inside the roller support unit 66, support walls 66c and 66d as bearings formed at intervals are provided, and a drive shaft 68 having a shaft disposed in the horizontal direction supports the support walls 66c and 66d in a rotatable manner. Has been.
In the state where the roller support unit 66 is incorporated in the apparatus main body 1a, as shown in FIG. 15, the separator main body 63 of the separator 44 is urged upward by a spring so that the outer peripheral surface of the paper supply roller 9 Is configured to be pressed against the pad 63c.

With such a configuration, when the image forming apparatus 1 is in the standby state in the non-printing state, as shown in FIG. 7, the rotation angle of the cam 57 is 0 degree, and the tension spring attached to the spring attachment portion 53 of the lever 51. With the spring force of 55, the guide plate 46 of the swing member 43 is lowered and pushed down to the default position.
When printing on a sheet using the manual feed tray 8, the manual feed tray 8 is first opened, and a required number of sheets are placed. In this state, the leading end of the sheet is placed on the guide plate 46. For example, a print command is issued by a personal computer.

The state shown in FIG. 16A shows an initial state in which the rotation angle of the cam 57 is 0 degree, and the cam 57 is rotated counterclockwise from the 0 degree position by driving means (not shown).
When the cam 57 is rotated by the print command, the driven portion 54a slides on the first area a on the outer peripheral surface of the cam 57 and the lever 51 rotates clockwise as shown in FIG. The leading end side of the restricting arm 52 rotates upward, the guide plate 46 pressed down by the restricting arm 52 moves upward by the spring force of the compression spring 59, and the leading end portion of the sheet also rises accordingly.

When the driven portion 54a reaches the second region on the outer peripheral surface of the cam 57, the push-up restricting arm 52 of the lever 51 is disposed at the upper position as shown in FIG. At this position, the engagement state of the guide plate 46 of the push-up restricting arm 52 is released, and the sheet on the guide plate 46 can come into contact with the outer peripheral surface of the paper feed roller 9.
At this time, since the swing member 43 including the lever 51 and the guide plate 46 is attached to one guide unit 41, the height of the guide plate 46 and the position in the front-rear direction can be accurately arranged. . Further, because of the relationship between the swing member 43 and the paper feed roller 9, the swing member 43 that has been conventionally attached to the paper feed tray 8 side is attached to the same apparatus body 1a side as the paper feed roller 9, so that the guide plate The positional relationship between 46 and the paper feed roller 9 can be arranged more accurately than in the past.
Furthermore, since the separator 44 is assembled to the guide unit 41 and the guide unit 41 is attached to the apparatus main body 1a on the side where the paper feed roller 9 is attached, the positional relationship between the separator 44 and the paper feed roller 9 is accurately arranged. can do.

The compression spring 59 attached to the guide plate 46 of the rocking member 43 feeds the sheet by changing the length of the compression spring 59 in any case where a single sheet is stacked. It can be pressed against the paper roller 9.
On the other hand, when a print command is issued, the paper feed roller 9 is rotated in a direction to feed the sheet to the conveyance path 7 (see FIG. 2) of the apparatus main body 1a by driving means (not shown). By the rotation of 9, it can be transferred to the conveyance path 7 so as to be caught.
At this time, when two or more sheets are stacked, the two sheets may be simultaneously transferred into the apparatus main body 1a by the frictional force between the sheets. In such a state, since the lower sheet is disposed on the separator 44, the lower sheet contacts the pad 63 c of the separator 44. At this time, since the frictional force between the lower sheet and the pad 63c is larger than the frictional force between the sheets, the transfer of the lower sheet in contact with the pad 53c is stopped, and only the upper sheet is fed. The paper is transferred into the transport path 7 by the paper roller 9.

In the disengagement region b of the cam 57, the rotation of the lever 51 is stopped at the almost raised position even when the cam 57 is in a rotating state, the cam 57 further rotates, and the driven portion 54a is engaged with the cam 57. When reaching the descending region b from the mating release region b, the lever 51 is rotated counterclockwise. At this time, the upward pressing of the driven portion 54a by the cam 57 is released, and the distal end portion 52c of the regulating arm 52 gradually descends. Therefore, the tip 52c abuts against the regulating piece 46a of the guide plate 46, and the spring force of the tension spring 55 is greater than the spring force of the compression spring 59. Also, the engagement with the paper feed roller 9 is released, and the guide plate 46 is lowered downward and pushed down to the default position.
Thus, when the cam 57 makes one rotation, the cam 57 returns to the initial 0 degree position shown in FIG. When printing one sheet, it waits at this initial position until the next print command is issued. When printing a plurality of sheets, the operations shown in FIGS. The process is repeated sequentially until the printing of one sheet is completed.
As described above, in this embodiment, the swinging member 43 is not assembled to the manual feed tray 8 but is assembled to the apparatus main body 1a side, and the guide plate 46 of the swinging member 43 is moved from the lower default position to the feed roller 9. It can be moved (lifted) to the paper feed position.

The embodiments of the present invention have been described above. However, of course, the present invention can be variously modified or changed based on the technical idea of the present invention.
For example, in the above-described embodiment, the image forming apparatus has been described as a printing apparatus. However, in addition to a printing machine, the present invention can be applied to a copy tray, a FAX, and a manual feed tray of these multifunction peripherals.

1 is a perspective view of an image forming apparatus as a printing apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the image forming apparatus when the image forming apparatus of FIG. FIG. 2 is a perspective view of a manual tray portion in a state where an outer panel of the image forming apparatus of FIG. 1 is removed. FIG. 2 is a perspective view of the image forming apparatus showing the position of an embedded portion of the guide unit of the image forming apparatus of FIG. It is a front view of the state which mounted | wore the apparatus main body with the guide unit shown in FIG. It is an expansion perspective view of the guide unit shown in FIG. FIG. 5 is an enlarged perspective view of a guide unit and a paper feed roller shown in FIG. 4 (a guide plate is in a lowered position). FIG. 5 is an enlarged perspective view of a guide unit and a paper feed roller shown in FIG. 4 (a guide plate is in a raised position). It is a perspective view of the rocking | swiveling member arrange | positioned at the guide unit shown in FIG. It is a perspective view of the lever which regulates the raise of the guide plate of the guide unit shown in FIG. It is a side view which shows the relationship between the guide plate of the guide unit shown in FIG. 4, a lever, and a cam. It is an expansion perspective view of the one side part of the guide unit shown in FIG. It is a perspective view of the separator arrange | positioned at the guide unit shown in FIG. FIG. 2 is a perspective view of a roller support unit that supports a paper feed roller disposed in the image forming apparatus of FIG. 1. It is sectional drawing which shows the support structure of the paper feed roller shown in FIG. FIGS. 2A and 2B are diagrams for explaining the operation of a guide plate, a lever, and a cam of the image forming apparatus of FIG. 1 is a side view of a state where the driven portion is in a second region of the cam, and D is a side view of a state where the driven portion is in a third region of the cam. FIG. 10 is a side view of a sheet feeding unit in a manual feed tray unit of an image forming apparatus according to a conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 1a Apparatus main body 1c Recess 8 Manual feed tray 9 Paper feed roller 41 Guide unit 43 Oscillating member 44 Separator 46 Guide plate 50 Lifting mechanism 51 Lever 52 Push-up restricting arm 52c Tip part 53 Spring mounting arm 54 Cam driven arm 54a Sliding part 55 Tension spring 57 Cam 59 Compression spring

Claims (4)

A manual feed tray that is openable and closable with respect to the apparatus main body, a paper feed roller that is rotatably supported on the apparatus main body side and feeds a sheet placed on the manual feed tray to a conveyance path of the apparatus main body, and a sheet An image forming apparatus provided with a guide plate that can be moved up and down to move the leading end of a sheet to the height of the paper feed roller and a separator that presses the outer peripheral surface of the paper feed roller when the paper is fed to the conveyance path ,
A guide unit that supports the guide plate so as to be movable up and down is provided, the guide unit is fixed to the apparatus main body corresponding to the leading end position of the sheet placed on the manual feed tray, and the guide unit is attached to the manual feed tray. An image forming apparatus, wherein the image forming apparatus is attached in a non-engaged state.   The image forming apparatus according to claim 1, wherein the separator is supported by the guide unit. The mechanism for raising and lowering the guide plate includes a swingable lever member and a cam member that contacts the lever member,
The lever member engages with the guide plate, the follow-up restricting arm, a follower that contacts the cam member and raises the push-up restricting arm by rotation of the cam member, and the push-up restricting arm lowers the guide plate. And a spring mounting portion to which a first spring for biasing is attached,
The said guide plate was equipped with the 2nd spring which urges | biases the said guide plate upwards, The said 1st spring force was made to enlarge the said 2nd spring force, The Claim 1 or 2 of Claim 1 or 2 Image forming apparatus.   In the outer peripheral contour of the cam member on which the driven portion slides, an ascending region for raising the push-up restriction arm, an engagement release region for releasing the engagement state of the push-up restriction arm with the guide plate, The image forming apparatus according to claim 3, further comprising a descending region that moves the push-up restricting arm to a descending position.

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