US20150001794A1

US20150001794A1 - Image forming apparatus

Info

Publication number: US20150001794A1
Application number: US14/311,643
Authority: US
Inventors: Shigeo Doi
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 2013-06-28
Filing date: 2014-06-23
Publication date: 2015-01-01
Also published as: JP2015028610A; CN104249944A

Abstract

An image forming apparatus includes an apparatus body, a door supported by the apparatus body turnably within a range of a first turning angle, a sheet stacking tray supported by the door turnably within a range of a second turning angle, and a bias member whose first end is fixed to the apparatus body and whose second end is fixed to the sheet stacking tray. The bias member pulls the sheet stacking tray to the apparatus body side by a bias force generated by the door pulling the bias member when the door is opened in the state in which the sheet stacking tray is opened and reduces a turning angle of the sheet stacking tray formed with the door to be smaller than the second turning angle at least when the door is turned by the first turning angle.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to an image forming apparatus configured to form an image on a sheet.
2. Description of the Related Art
Heretofore, there is known such an image forming apparatus including a sheet feed portion provided at an under part the image forming apparatus and feeding a sheet, an image forming portion provided above the sheet feed portion and forming an image on the sheet fed from the sheet feed portion, and a sheet discharge portion provided at an upper part of the image forming apparatus and to which the sheet on which the image has been formed is discharged. The image forming apparatus also includes a conveying path configured to move the sheet upward and a door (side cover) permitting to expose the conveying path, when it is opened, and provided along one side surface of an apparatus body so that a jam handling process and maintenance works can be readily carried out.
Still further, in an image forming apparatus in which a manual feed portion configured to allow a user of the apparatus to manually feed a sheet is provided on the door, a manual feed tray of the manual feed portion is turnably supported by the door and the manual feed tray is used by turning so as to be able to stack sheets when the user manually feed the sheets. Due to that, if the door is opened in the state in which the sheets are stacked on the manual feed tray, the manual feed tray is inclined further by the turn of the door, possibly shifting positions of the stacked sheets on the manual feed tray and dropping the sheet from the manual feed tray. This trouble requires a user of the image forming apparatus to correct the stacking position of the sheets on the manual feed tray in manually feeding the sheet. This work is very cumbersome for the user.
It is noted that the manual feed portion is configured such that the user can perform the image forming operation on a sheet having difference size or on a different type of sheet from sheets stored in a sheet feed cassette or the like of the apparatus body by setting such sheet on the manual feed tray.
With regard this problem, Japanese Patent Application Laid-open No. 2012-13828 proposes a configuration in which the body of the image forming apparatus is linked with the manual feed tray by a flexible string or belt-like link member and a turning range of the manual feed tray in opening the door is restricted by the link member so as to hung the manual feed tray.
Here, the belt-like link member described above has a substantially constant length and restricts the turning range of the manual feed tray even in a state in which the door is closed, not only in the state in which the door is opened. While there is such a demand that the user wants to turn the manual feed tray to an angle close to a horizontal level in a state in which the door is closed from an aspect of usability. However, if the turning range of the manual feed tray in the state in which the door is closed is increased, the initial turning angle of the manual feed tray in opening the door approaches the horizontal level. The manual feed tray tries to move in a direction approaching the horizontal level further from the initial turning angle when the door is turned and opened. Accordingly, there is a problem that it is hard to set the turning range of the manual feed tray in the state in which the door is closed to be large in order to prevent the sheet from dropping from the manual feed tray in the state in which the door is opened.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, an image forming apparatus of includes an apparatus body, a door supported by the apparatus body turnably within a range of a first turning angle, a sheet stacking tray supported by the door turnably within a range of a second turning angle and stacking a sheet in a state opened with respect to the door, and a bias member whose first end is fixed to the apparatus body and whose second end is fixed to the sheet stacking tray, the bias member pulling the sheet stacking tray to the apparatus body side by a bias force generated by the door pulling the bias member when the door is opened in the state in which the sheet stacking tray is opened and reducing a turning angle of the sheet stacking tray formed with the door to be smaller than the second turning angle at least when the door is turned by the first turning angle.
According to another aspect of the present invention, an image forming apparatus includes an apparatus body, a door supported by the apparatus body turnably centering on a door turning shaft, a sheet stacking tray supported by the door turnably centering on a tray turning shaft located above the door turning shaft and stacking a sheet, a flexible link mechanism whose one end is linked turnably to the apparatus body and whose other end is linked slidably to the sheet stacking tray, a slide mechanism slidably supporting the other end of the link mechanism, and a bias member linked to the other end of the link mechanism and to the sheet stacking tray, the flexible link mechanism being stretched to its maximum length when the door is opened in a state in which the sheet stacking tray is opened with respect to the door and the other end of the link mechanism being supported by the slide mechanism to be slidable in the state in which the link mechanism is stretched to its maximum length.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section view schematically showing a printer according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control portion of the printer of the embodiment.

FIG. 3 is a section view showing a state in which a door of the printer shown in FIG. 1 is opened.

FIG. 4 is a section view showing a state in which a manual tray of the printer shown in FIG. 1 is opened.

FIG. 5 is a section view showing a state in which sheets are stacked on the manual tray of the printer.

FIG. 6 is a section view showing a state in which the door is opened by about a half in a state in which the manual feed tray stacking the sheets is opened.

FIG. 7 is a section view showing a state in which the door is opened in the state in which the manual feed tray stacking the sheets is opened.

DESCRIPTION OF THE EMBODIMENTS

An image forming apparatus according to an embodiment of the present invention will be described below with reference to FIGS. 1 through 7. The image forming apparatus according to the present embodiment of the present invention is provided with a manual feed tray in a door capable of exposing a conveying path such as a copier, a printer, a facsimile, a multi-function printer or the like. The image forming apparatus of the present invention will be described by exemplifying an electro-photographic printer (referred to simply as a ‘printer’ hereinafter) 100 forming four colors of toner images.
At first, a schematic structure of the printer 100 of the present embodiment will be described with reference to FIGS. 1 through 3. FIG. 1 is a section view schematically showing the printer 100 of the present embodiment of the present invention, FIG. 2 is a block diagram showing a configuration of a control portion 50 of the printer 100 of the present embodiment, and FIG. 3 is a section view showing a state in which a door 102 of the printer 100 shown in FIG. 1 is opened.
As shown in FIG. 1, the printer 100 includes a sheet feed portion 10 storing a sheet S in a sheet feed cassette or the like and feeding the sheet S from the sheet feed cassette and a manual feed portion 20 enabling to manually feed a sheet S. The printer 100 also includes an image forming portion 30 configured to form an image on the sheet S fed from the sheet feed portion 10, a discharge roller pair 40 discharging the sheet S out of the apparatus, and a control portion 50 controlling these portions.
The sheet feed portion 10 is provided at a lower part of the printer 100 and includes a fed sheet stacking portion (sheet feed cassette) 11 and a sheet feed roller pair (sheet feed member) 12 feeding the sheet S stacked in the fed sheet stacking portion 11. It is noted that a pickup portion picking up the sheet S out of the fed sheet stacking portion 11 is not shown in FIG. 1. The manual feed portion 20 is provided on one side portion (right-hand side in FIG. 1) of the printer 100. It is noted that the manual feed portion 20 will be described in detail later.
The image forming portion 30 is provided above the sheet feed portion 10 and includes photoconductive drums 31 a through 31 d on which toner images of yellow, magenta, cyan and black colors are formed and an exposure unit 32 irradiating a laser beam to the photoconductive drums 31 a through 31 d. The image forming portion 30 also includes a transfer portion 33 transferring the toner images on the sheet S, and a fixing portion 34 fixing the toner images transferred to the sheet S. The discharge roller pair 40 is provided at an upper part of the printer 100 (above the image forming portion 30).
As shown in FIG. 2, the control portion 50 includes a CPU 51 driving and controlling the sheet feed portion 10 and others and a memory 52 storing various programs, various information and others.
As shown in FIG. 3, the printer 100 also includes a body 101 of the printer (referred to simply as a ‘printer body’ or an ‘apparatus body’ hereinafter) and a side cover (referred to simply as a ‘door’ hereinafter) 102 capable of exposing an inside (a conveying path conveying and guiding a sheet) of the printer body 101. The sheet feed portion 10, the image forming portion 30 and others are disposed within the printer body 101. The manual feed portion 20 is disposed within the door 102. The door 102 is provided on one side (on the right-hand side in FIG. 3) of the printer body 101 and is supported by the printer body 101 turnably centering on a door turning shaft 103 provided at a lower part of the printer body 101. It is noted that an opening angle a (first turning angle) of the door 102 formed between the door 102 and the printer body 101 is restricted by a door turning angle restricting portion (first turn restricting portion) 102A composed of a four joint link constructed by using an arm member 102A1 whose one end is turnably attached to the printer body 101 and whose other end is slidably attached to the door 102 to a range enabling a user to carry out a jam handing process, and a maximum opening angle a of the door 102 is set at about 40° in the present embodiment.
The door 102 also opens (exposes) a part of the conveying path 104 conveying the sheet S when it is opened and composes a part of the conveying path 104 when it is closed (see FIG. 1). It is noted that the conveying path 104 composed a so-called vertical path extending from the sheet feed portion 10 upward toward the discharge roller pair 40 while passing through a transfer nip N of the transfer portion 33 and the fixing portion 34. The door 102 is provided with a duplex conveying path 107 and a 110 described later.
Next, an image forming operation of the printer 100 (image forming control made by the control portion 50) will be briefly described based on the components described above. In response to a start of the image forming operation, the exposure unit 32 irradiates the laser beam on surfaces of the photoconductive drums 31 a through 31d corresponding to an image information signal transmitted from a personal computer or a document reading portion not shown. Thereby, the surfaces of the photoconductive drums 31 a through 31 d charged with predetermined polarity and potential are exposed and electrostatic latent images are formed. When the electrostatic latent images are formed on the surface of the photoconductive drums 31 a through 31 d, a developing portion not shown develops the electrostatic latent images and visualizes as toner images. The visualized respective toner images are superimposed and transferred to an intermediate transfer belt and are conveyed to the transfer nip N of the transfer portion 33 by the intermediate transfer belt.
In parallel with the toner image forming operation described above, the sheet feed roller pair 12 feeds the sheets S stacked in the fed sheet stacking portion 11 to the conveying path 104 while separating one by one. It is noted that in a case of manual feed, the manual feed portion 20 feeds the sheet S toward the conveying path 104. Then, when the sheet S is fed to the conveying path 104, a registration roller pair 105 conveys the sheet S to the transfer nip N with timing synchronized with the toner image on the intermediate transfer belt and the transfer portion 33 transfers the toner image on the sheet S. After that, the fixing unit 34 fixes the toner image by heat and pressure and the discharge roller pair 40 discharges the sheet S out of the apparatus. The sheet S discharged out of the apparatus is stacked on a discharged sheet stacking portion (discharge tray) 106 provided at an upper part of the printer 100.
It is noted that in a case where images are formed on both surfaces (first and second surfaces) of the sheet S, the discharge roller pair 40 is rotated reversely before the sheet S is discharged out of the apparatus to convey the sheet S to a duplex conveying path 107. Then, duplex conveying roller pairs 108 and 109 feed the sheet S through the duplex conveying path 107 again to the conveying path 104 and the image forming portion 30 forms an image on the second surface of the reversed sheet S. An operation thereafter is the same with what described above, so that an explanation thereof will be omitted here.
Next, the manual feed portion 20 described above will be described with reference to FIGS. 4 through 7. At first, a configuration of the manual feed portion 20 will be described with reference to FIG. 4. FIG. 4 is a section view showing a state in which a manual feed tray 21 of the printer 100 shown in FIG. 1 is opened.
As shown in FIG. 4, the manual feed portion 20 includes the manual feed tray 21 on which the sheet S is stacked and a manual feed roller pair (manual feed member) 22 feeding the sheet S stacked on the manual feed tray 21. The manual feed portion 20 also includes a link unit (link mechanism) 23 linking the manual feed tray 21 with the printer body 101 and restricting a turning angle of the manual feed tray 21 formed with the printer body 101 such that the turning angle becomes less than a predetermined turning angle.
The manual feed tray 21 is provided on one side (right-hand side in FIG. 4) of the door 102 and is supported by the door 102 turnably centering on a tray turning shaft (turning shaft portion) 21 a provided at a lower part of the one side surface of the door 102 and above the door turning shaft 103 of the door 102. The manual feed tray 21 is also constructed such that it can be stored within the door 102 so as not to project out of a case surface of the door 102 when the manual feed tray 21 is closed (see FIG. 1). It is noted that an opening angle β (second turning angle) of the manual tray 21 formed between the door 102 in the closed state and the manual tray 21 is restricted by a tray turning angle restricting portion (second turn restricting portion) 20A composed of a four joint link constructed by using an arm member 201A1 whose one end is turnably attached to the door 102 and whose other end is slidably attached to the maximum opening angle β of the manual tray 21=about 70° in the present embodiment.
The manual feed roller pair 22 is provided along a manual feed path 110 connecting the conveying path 104 with the manual feed portion 20 and conveys the sheet S stacked on the manual feed tray 21 to the conveying path 104 through the manual feed path 110. It is noted that a pickup portion picking up the sheet S stacked on the manual feed tray 21 is not shown in FIG. 4.
The link unit 23 includes a flexible (bendable) link portion 24 and a bias portion 25 biasable so as to be able to raise the manual feed tray 21 to the printer body 101 side (apparatus body side). The link portion 24 of the present embodiment is a link mechanism composed of a first link member 24 a whose one end is turnably supported by the printer body 101 and a second link member 24 b linked to another end of the first link member 24 a. The bias portion 25 is composed of a bias spring (bias member) 26 connected to another end of the second link member 24 b and a slide mechanism 27 sliding the other end of the second link member 24 b substantially in parallel with a stacking surface 21 c of the manual feed tray 21. The bias spring 26 is a coil spring.
One end of the first link member 24 a is supported by the printer body 101 turnably above the tray turning shaft 21 a of the manual feed tray 21. Another end of the first link member 24 a is linked flexibly with one end of the second link member 24 b by a link shaft 28. One end (first end) of the bias spring 26 is connected to the other end of the second link member 24 b and another end the bias spring 26 is connected to an end portion 21 b of the manual feed tray 21. Then, the bias spring 26 biases the second link member 24 b so as to pull toward the end portion 21 b side of the manual feed tray 21. Accordingly, the link portion 24 composed of the first and second link members 24 a and 24 b is configured such that the link portion 24 can bend or extend as the door 102 and the manual feed tray 21 are opened/closed.
As described above, the first end of the bias spring 26 is fixed to the printer body 101 through the link portion 24 and the second end thereof is fixed to the manual feed tray 21 such that the bias spring 26 pulls up the manual feed tray 21 when the door 102 is opened as described later in detail. That is, the bias spring 26 pulls the manual feed tray 21 to the printer body side by a bias force generated when the door 102 is opened in the state in which the manual feed tray 21 is opened and reduces the turning angle of the manual feed tray 21 formed with the door 102 to a turning angle small than the second turning angle β at least when the door 102 is opened to the first turning angle α. Therefore, the stronger the bias force of the bias spring 26, the more the position of the manual feed tray 21 tends to be stabilized. However, if the bias force is too strong, there is a possibility that the manual feed tray 21 jumps up in linkage with the operation of opening the door 102. Then, the bias force of the bias spring 26 is set such that the position of the manual feed tray 21 can be maintained in a state in which the sheets S are fully loaded on the manual feed tray 21. For instance, a force around 30 N will suffice as a force necessary for pulling up a total weight of a weight of the manual feed tray 21 and a maximum loading weight of the sheets S and the bias force of the bias spring 26 is set at 30 N in the present embodiment.
The slide mechanism 27 includes a projection 27 a provided at the other end of the second link member 24 b and a slide member 27 b through which a 27 c sliding the projection 27 a (the other end of the second link member 24 b) substantially in parallel with the manual feed tray 21 c of the manual feed tray 21. While the slide member 27 b is attached to the manual feed tray 21, the slide member 27 b may be formed integrally with the manual feed tray 21.
Next, an operation (action) of the manual feed tray 21 when the door 102 is opened in the state in which the manual feed tray 21 is opened will be explained with reference to FIGS. 5 through 7 in addition to FIG. 1. FIG. 5 is a schematic section view of the apparatus showing a state in which the sheets S are stacked on the manual feed tray 21 of the printer 100, FIG. 6 is a schematic section view of the apparatus showing a state in which the door 102 is opened by about a half in the state in which the manual feed tray 21 stacking the sheets S is opened, and FIG. 7 is a schematic section view of the apparatus showing a state in which the door 102 is opened in the state in which the manual feed tray 21 stacking the sheets S is opened.
As shown in FIG. 1, the first and second link members 24a and 24 b bend at the link shaft 28 in a state in which the manual feed tray 21 is stored in the door 102 and are configured so as not to interfere the storage of the manual feed tray 21 at a position close to each other. The bias spring 26 is contracted and the projection 27 a (the other end of the second link member 24 b) is located at a front edge side of the slide groove 27 c.
When the manual feed tray 21 is pulled out from this state, the second link member 24 b turns centering on the link shaft 28 in linkage with the turn of the manual feed tray 21 and stops the turn of the manual feed tray 21 as the end on the manual tray 21 side of the arm member 20A1 of the tray turning angle restricting portion 20A slides to a sliding limit position on the door side as shown in FIG. 5. The bias spring 26 is contracted also at this time and the projection 27 a (the other end of the second link member 24 b) is located at the front edge of the slide groove 27 c. The link portion 24 is kept in the bended state because the door turning shaft 103 of the door 102 and the tray turning shaft 21 a of the manual feed tray 21 are located at the same position in terms of a horizontal direction (horizontal direction in FIG. 4) of the printer body 101. That is, a turning range of the manual feed tray 21 is not restricted by the link unit 23 and the link unit 23 does not interfere the turn of the manual feed tray 21 when the manual feed tray 21 is just opened/closed.
In this state, the first and second link members 24 a and 24 b bend and the link shaft 28 is located near the manual feed tray 21 c of the manual feed tray 21. In other words, the first link member 24 a is located along the printer body 101 and the second link member 24 b is located along the manual feed tray 21. Therefore, the first and second link members 24 a and 24 b do not interfere the user in stacking the sheets S on the manual feed tray 21.
When the door 102 is turned in an opening direction from this state, the first and second link members 24 a and 24 b are stretched as the manual feed tray 21 separates from the printer body 101. It is because the tray turning shaft 21 a of the manual feed tray 21 gradually separates in the right-hand side of the printer body 101 (the right-hand side in FIG. 4) with respect to the door turning shaft 103 of the door 102. Thereby, the bended first and second link members 24 a and 24 b are gradually substantially straightened, i.e., extended to a maximum length, during when the door 102 is opened to its maximum opening angle. When the door 102 is turned further from the state in which the first and second link members 24 a and 24 b are substantially straightened, the other end of the second link member 24 b (the projection 27 a) moves to the tray turning shaft 21 a side along the slide groove 27 c by going against the bias force of the bias spring 26 and pulls the bias spring 26.
When the door 102 is opened by about a half (α/2) as shown in FIG. 6, the manual feed tray 21 turns along with the downward move of the door 102 in the state in which the manual feed tray 21 is restricted at a certain angle (70°) by the tray turning angle restricting portion 20A. At this time, the first and second link members 24 a and 24 b are stretched from the bending state and the link unit 23 is stretched to its maximum length. Until when the link unit is stretched to its maximum length, the tray turning angle restricting portion 20A provided in the opening door 102 restricts an inclination of the manual feed tray 21 because the first and second link members 24 a and 24 b are configured so as not to interfere the opening operation of the manual feed tray 21. Due to that, a relative angle between the manual feed tray 21 and a floor surface is reduced by opening the door 102. While this relative angle depends also on the relationship between the first and second link members 24 a and 24 b and others, the relative angle of the manual feed tray 21 formed with the floor surface changes within a range of 20 to 5° in the present embodiment.
It is noted that while the length of the link unit 23 is maximized when the door 102 is opened by about a half as shown in FIG. 6 in the present embodiment, the opening angle of the door 102 when the link unit 23 is stretched to its maximum length is not limited to that. The opening angle of the door 102 when the link unit 23 is stretched to its maximum length may be set at any angle as long as it is less than an angle when the door 102 is opened in maximum.
As shown in FIG. 7, when the door 102 is turned further, the other end of the second link member 24 b (the projection 27 a) moves to a base end (the tray turning shaft 21 a side) of the slide groove 27 c as the link unit 23 has already stretched to its maximum length. The bias spring 26 is stretched by this move of the projection 27 a of the second link member 24 b.
When the bias spring 26 is stretched to its maximum length, i.e., when the link unit 23 is stretched to its maximum length, a force acts on the manual feed tray 21 in a direction of raising the manual feed tray 21 to the door 102 side centering on the tray turning shaft 21 a by a bias force (resilient force) of the bias spring 26. Thereby, the manual feed tray 21 rises vigorously so as to approach the door 102 more than the previous state (the state in FIG. 7). When the manual feed tray 21 rises, the sheets S stacked on the manual feed tray 21 move to the manual feed roller pair 22 side even if they are shifted.
As described above, according to the printer 100 of the present embodiment, because the bias spring 26 is provided in the link unit 23, the manual feed tray 21 can be raised suitably before the door 102 is opened to the end. Due to that, the sheets S on the manual feed tray 21 will not drop when the door 102 is opened and the sheets S can be also returned to a feed position even if the stacked position of the sheets S is shifted from the feed position. Thereby, it is possible to prevent a feed jam otherwise caused by the shift of the feed position of the sheets S.
Still further, it is possible to buffer a shock otherwise acting on the manual feed tray 21 when the user vigorously opens the door 102 by providing the bias spring 26 in the link unit 23. Therefore, it is possible to reliably prevent the sheet S on the manual feed tray 21 from dropping and to reduce the occurrence of the shift of the position of the sheet S.
It is also possible to smooth the operation carried out in switching the moving direction of the manual feed tray 21 (the operation of the manual feed tray in turning up from the state shown in FIG. 7 in the present embodiment) by providing the bias spring 26 in the link unit 23. Accordingly, it is possible to reduce unnecessary sounds and shocks from being generated.
The printer 100 of the present embodiment uses the first and second link members 24 a and 24 b as the link portion 24 and the slide member 27 b. Therefore, the first and second link members 24 a and 24 b will not interfere the user in stacking the sheets S on the manual feed tray 21 for example.
The printer 100 of the present embodiment is configured such that the other end of the second link member 24 b (the other end of the set of links) is slidable and is biased in one direction. Therefore, the links can flexibly react without being strictly limited in terms of the length of the links, positions of centers of turn of the respective members and others. That is, the links makes it possible to flexibly deal with restrictions on design and precision of parts.
As described above, the printer 100 of the present embodiment suitably restricts the turning angle of the manual feed tray 21 regardless the opening/closing operation of the door 102 and can prevent the fall and the shift of the position of the sheets S stacked on the manual feed tray 21.
While the present embodiment of the present invention has been explained, the present invention is not limited to the present embodiment described above. Still further, the advantageous effects described in the present embodiment of the present invention are merely an enumeration of the most suitable effects brought about from the present invention, and the effects of the present invention are not limited to what described in the present embodiment of the present invention.
For instance, while the present embodiment has been explained by using the manual feed portion 20 as a sheet stacking portion, the present invention is not limited to that. When a discharged sheet stacking tray (sheet stacking tray) stacking the sheet S on which an image has been formed and has been discharged out of the apparatus is provided on a door capable of exposing an inside of the apparatus body, the sheet stacking portion described above is applicable to a discharge sheet stacking portion having a discharge sheet stacking tray.
Still further, while the present embodiment has been described by using the first and second link members 24 a and 24 b as the link portion 24, the present invention is not limited to that. For instance a member, e.g., a sheet-like or string-like member, formed of a flexible material such as bendable synthetic resin (polypropylene or the like) and rubber may be used as the link portion. It is possible to obtain the similar effects even if such member is used.
While the present embodiment has been also explained by using the bias spring 26 and the slide mechanism 27 as the bias portion 25, the present invention is not limited to such configuration. The bias portion may be composed of only the bias spring (bias member).
While the present embodiment has been also explained by using the bias spring 26 as the bias member 25, the present invention is not limited to that. The bias member may be constructed by using a hydraulic damper, a pneumatic damper or an elastic member. Still further, while the door turning angle restricting portion 102A and the tray turning angle restricting portion 20A are constructed by the four joint link in the embodiment described above, the door and tray turning angle restricting portions may be configured such that the end on the apparatus body side of the arm member 102A and the end on the door side of the arm member 20A slide for example. The turning angle restricting portions may be also constructed by any link structure other than the four joint link. The door and tray turning angle restricting portions 102A and 20A may be composed of any mechanism other than the link mechanism, such as a string-like member such as a wire of a predetermined length, a configuration in which a projection is fitted into a long hole, and a mechanism restricting a turning range of the door turning shaft 103 and the tray turning shaft 21 a by using gears and stoppers.
The present embodiment has been also explained by using the electro-photographic image forming process as the image forming portion forming an image on the sheet S, the present invention is not limited to such configuration. For instance, the image forming portion forming the image on the sheet S may be what uses an ink jet image forming process forming an image on the sheet S by discharging liquid ink from a nozzle.
While the present invention has been described with reference to the exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2013-137015, filed on Jun. 28, 2013, and Japanese Patent Application No. 2014-115637, filed on Jun. 4, 2014 which are hereby incorporated by reference herein in their entirety.

Claims

What is claimed is:

1. An image forming apparatus comprising:

an apparatus body;

a door supported by the apparatus body turnably within a range of a first turning angle;

a sheet stacking tray supported by the door turnably within a range of a second turning angle and stacking a sheet in a state opened with respect to the door; and

a bias member whose first end is fixed to the apparatus body and whose second end is fixed to the sheet stacking tray, the bias member pulling the sheet stacking tray to the apparatus body side by a bias force generated by the door pulling the bias member when the door is opened in the state in which the sheet stacking tray is opened and reducing a turning angle of the sheet stacking tray formed with the door to be smaller than the second turning angle at least when the door is turned by the first turning angle.

2. The image forming apparatus according to claim 1, further comprising a link mechanism including a first link attached to the apparatus body and a second link attached to the first end of the bias member, the link mechanism linking the apparatus body with the sheet stacking tray through the bias member and being flexible and stretchable as the door and the sheet stacking tray are opened/closed.

3. The image forming apparatus according to claim 2, wherein the link mechanism is stretched to its maximum length during when the door in the state in which the sheet stacking tray is opened turns up to the first turning angle.

4. The image forming apparatus according to claim 3, further comprising a slide mechanism configured to move an end of the second link on a side linked with the bias member along a stacking surface of the sheet stacking tray.

5. The image forming apparatus according to claim 4, wherein the bias member is pulled by the end of the second link in a state in which the link mechanism is stretched to its maximum length and the end of the second link is slid along the slide mechanism in response to an opening operation of the door.

6. The image forming apparatus according to claim 5, wherein the bias member includes a bias spring.

7. The image forming apparatus according to claim 6, further comprising a manual feed portion provided on one side surface of the apparatus body and capable of feeding a sheet into the apparatus body;

wherein the sheet stacking tray is a manual feed tray provided in the manual feed portion and stacking sheets to be fed into the apparatus body.

8. The image forming apparatus according to claim 7, further comprising a conveying path guiding the sheet being conveyed within the apparatus body;

wherein the conveying path is exposed by opening the door.

9. The image forming apparatus according to claim 1, further comprising a first turn restricting portion restricting a turning range of the door within the first turning angle; and

a second turn restricting portion restricting a turning range of the sheet stacking tray to the second turning angle.

10. An image forming apparatus comprising:

an apparatus body;

a door supported by the apparatus body turnably centering on a door turning shaft;

a sheet stacking tray supported by the door turnably centering on a tray turning shaft located above the door turning shaft and stacking a sheet;

a flexible link mechanism whose one end is linked turnably to the apparatus body and whose other end is linked slidably to the sheet stacking tray;

a slide mechanism slidably supporting the other end of the link mechanism; and

a bias member linked to the other end of the link mechanism and to the sheet stacking tray;

the flexible link mechanism being stretched to its maximum length when the door is opened in a state in which the sheet stacking tray is opened with respect to the door and the other end of the link mechanism being supported by the slide mechanism to be slidable in the state in which the link mechanism is stretched to its maximum length.