The present disclosure relates to image forming apparatuses for forming an image on a recording medium, such as a transfer material, a print sheet, photosensitive paper, or an electrostatic recording sheet. In particular, the present disclosure relates to an image forming apparatus including a cover that can be opened or closed with respect to the image forming apparatus.
In an image forming apparatus, an improvement in the user operability of the opening and closing cover is sometimes a challenge. In other words, high rigidity of the cover, a good feel in operating the cover, and a good feeling in an opening or closing operation may be required. Among them, in the cover opening operation, the cover can swing open, or the opened door can bounce to decrease the quality feeling of the apparatus.
For those reasons, known image forming apparatuses in the art have a braking mechanism that exhibits their effects according to the cover opening or closing operation to improve the operational feeling in opening or closing the opening and closing cover.
An example configuration is illustrated in
Another example illustrated in
However, in the configuration disclosed in Japanese Patent Laid-Open No. 2003-87464, the braking force is produced by the interference between the resin components. Therefore, a large braking force may damage the components. Therefore, this configuration cannot give a sufficient braking force to a large, heavy cover.
The braking mechanism disclosed in Japanese Patent Laid-Open No. 2017-3892 produces a high torque using the damper and the gear train but needs a large space for the braking mechanism and high cost.
The configuration disclosed in Japanese Patent Laid-Open No. 2004-45585 requires a large damper to exhibit a sufficient damper function.
The present disclosure provides an image forming apparatus including a cover configured to be opened or closed by rotating with respect to the image forming apparatus and a cover support portion openably and closably supporting the cover on the image forming apparatus. The cover support portion includes a clamping portion and a pressure member. The clamping portion is configured to contact and clamp part of the cover or part of the cover support portion in a turning radius direction of the cover. The pressure member is mounted to the clamping portion to press the clamping portion.
Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Embodiments of the present disclosure will be described hereinbelow in detail with reference to the drawings. It is to be understood that the components described in the embodiments are given for mere illustrative purposes, and the scope of the present disclosure is not limited to the embodiments.
In
In an image forming process, first, the surfaces of the photosensitive drums 2Y, 2M, 2C, and 2K having an organic photoconductive layer are respectively uniformly charged by charging rollers 3Y, 3M, 3C, and 3K. Thereafter, the photosensitive drums 2Y, 2M, 2C, and 2K are selectively exposed to a laser beam emitted from a laser scanner 5 to form electrostatic latent images.
These electrostatic latent images are provided with toners, which are color developers, by developing units 4Y, 4M, 4C, and 4K and are developed as toner images on the photosensitive drums 2Y, 2M, 2C, and 2K.
An intermediate transfer belt unit 7 includes an intermediate transfer belt 8 stretched across a driving roller 9 and a driven roller 10. Primary transfer rollers 11Y, 11M, 11C, and 11K are driven while being in contact with the photosensitive drums 2Y, 2M, 2C, and 2K with the intermediate transfer belt 8 therebetween. The intermediate transfer belt 8 is rotationally driven clockwise in
A predetermined transfer bias is applied to the primary transfer rollers 11Y, 11M, 11C, and 11K, and color toner images on the surfaces of the photosensitive drums 2Y, 2M, 2C, and 2K are layered in sequence on the intermediate transfer belt 8 to form a four-color toner image.
A sheet cassette 12 contains transfer materials Q (recording media), such as plane paper or heavy paper. The transfer materials Q are fed by a feed roller 13. Thereafter, each transfer material Q passes through a conveying roller pair 14 and a registration roller pair 15 and is conveyed to a secondary transfer position at which the intermediate transfer belt 8 and a secondary transfer roller 16 are in contact. At the secondary transfer position, the four-color toner image on the intermediate transfer belt 8 is transferred onto the transfer material Q by the secondary transfer roller 16 to which a predetermined bias is applied.
The transfer material Q to which the four-color toner image is transferred is conveyed to a fixing roller pair 17, where the toner image is melted and fixed onto the transfer material Q by heat and pressure to form a color image on the transfer material Q. The transfer material Q conveyed by the fixing roller pair 17 passes through a discharge roller pair 18 and is discharged and stacked onto an output tray.
The cartridge tray 6 and the intermediate transfer belt unit 7 can be mounted and demounted in the direction of arrow A in
The opening and closing door 19, which is a cover that can be opened or closed with respect to the image forming apparatus, can be opened or closed with respect to the main body of the image forming apparatus by operating a handle 20.
As illustrated in
As illustrated in
The opening and closing door 19 is supported by the cover support portions—the door hinge 27 on the left side and the door hinge 28 on the right side viewed from the front (with the opening and closing door 19 at the front)—so as to be rotatable about a rotation axis 22 indicated by the chain line in
Two handle claws 21 of the handle 20 are disposed on the back of the opening and closing door 19. The handle claws 21 engage with engaging grooves 23 of the apparatus main body 1. Urging the handle 20 with an urging unit allows the opening and closing door 19 to be held in a closed state.
Claws 24 (engaging portions) are provided at two corners of the opening and closing door 19. The claws 24 engage with engaging holes 25 of the apparatus main body 1, thereby preventing an end of the opening and closing door 19 from being separated from the apparatus main body 1 in a state in which the opening and closing door 19 is closed. The opening and closing door 19 also has metal stays 26 to prevent the claws 24 serving as engaging portions from not firmly engaging with the engaging holes 25 due to insufficient strength or warping of the opening and closing door 19.
The left door hinge 27 illustrated in
The structure illustrated in
The opening and closing door 19 includes a door protrusion 19b, which is pressed and clamped by a braking mechanism (to be described later) to provide resistance against the motion of the opening and closing door 19, thereby improving the operational feeling. The door protrusion 19b is part of the opening and closing door 19. Since the door protrusion 19b moves in contact with a clamping portion of the cover support portion to generate a braking action, the opening motion of the opening and closing door 19 is delayed. In addition to the door protrusion 19b, the opening and closing door 19 partly includes an arc-shaped first hinge cover 19c for covering the door hinge 27 and a second hinge cover 19d for covering the door hinge 27, the second hinge cover 19d having a hinge engaging hole 19a.
The opening and closing door 19 further partly includes an arc-shaped protrusion 19e having a circular surface along the direction of rotation of the opening and closing door 19. The arc-shaped protrusion 19e also has a structure for providing resistance to the motion of the opening and closing door 19 when moving in contact with the clamping portion of the cover support portion. Therefore, in the present embodiment, the clamping portion and the arc-shaped protrusion 19e start to contact from the state where the opening and closing door 19 is opened to 45° from the closed state (0°), so that the arc-shaped protrusion 19e pushes the upper part of the clamping portion upward. Against it, the pressure member applies pressure to the arc-shaped protrusion 19e via the clamping portion to generate a braking force. When the opening and closing door 19 is fully opened (90°), the arc-shaped protrusion 19e and then the door protrusion 19b come into contact with the clamping portion.
The clamping portion of the door hinge 27 is thus constituted by two members—the door hinge left frame 27c (a first member) and the brake cover 29 (a second member), thereby remarkably reducing a stress acting on the clamping portion itself. Thus, a braking mechanism that exerts a large braking force against the door protrusion 19b can be provided.
Thus interposing members between the pressure member and the member to be braked reduces damage to the door protrusion or the clamping portion. This allows a mechanism that provides a sufficient braking force to be provided while saving the space.
The brake disk 30 is configured to be in contact with the portion of the door hinge left frame 27c in contact with the door protrusion 19b of the brake cover 29 from the outside and both sides in the direction of the turning radius.
The braking mechanism employed in the first embodiment is constituted by only the periphery of the door hinge 27 so as to look well even with the door opened (in a door opened state). In other words, it is necessary to provide a large pressing, clamping force to apply a brake in the vicinity of the fulcrum of the rotation (or the turning fulcrum) of the opening and closing door 19. Furthermore, since the braking mechanism is composed only by the periphery of the door hinge 27, the appearance can be enhanced by hiding the hinge 27 with the first and second hinge covers 19c and 19d.
To provide such a configuration, the braking mechanism is configured so that the pressing direction of the brake disk 30 (the direction of arrow D in
The present embodiment employs a general galvanized steel plate as the material of the brake disk 30.
A necessary braking force can be adjusted by optimizing the brake disk 30 according to the size or weight of the opening and closing cover 19. If a sufficient braking force is not obtained, two metal plates may be used as in the present embodiment, or the thickness or shape of the metal plate may be changed. Furthermore, a high-strength material (a stainless steel spring material or a high-tensile steel plate) may be used.
The operation of the braking mechanism will be described hereinbelow.
In a state in which the opening and closing door 19 is closed, the door protrusion 19b of the opening and closing door 19 is not pressed by the door hinge left frame 27c and the brake cover 29 (the clamping portion of the cover support), so that no braking force acts on the opening and closing door 19. If a braking force always acts on the opening and closing door 19, the opening and closing door 19 is prone to bias closing, and a large closing force is required.
In a state in which the opening and closing door 19 is fully opened, the rib on the back of the door protrusion 19b is hooked by a door stopper 27b of the left door hinge 27 to retain the opening and closing door 19.
The braking mechanism is configured so that a braking force acts on the way the opening and closing door 19 opens from the state in
Actually, in a state in which the opening and closing door 19 is fully opened, the brake disk 30 is expanded to move the brake cover 29 into the state in
Thus, a braking force during the operation of the opening and closing door 19 can be generated by clamping the door protrusion 19b with the cover sliding surface 29b and the hinge sliding surface 27d using the pressing force of the brake disk 30 (the pressure member). In the present embodiment, the braking force is generated in the latter half of the rotation of the opening and closing door 19 from the closed state to the opened state. However, this configuration is given for mere illustrative purposes. For example, the braking force may be generated in the latter half of rotation to the closed state opposite to that of the present embodiment. The braking force may be generated at two positions immediately before the opening and closing door 19 is fully opened and immediately before the opening and closing door 19 is completely closed.
To provide a stable braking force, it is necessary to manage the amount of interference, F, between the cover sliding surface 29b and the door protrusion 19b illustrated in
As described above, the present embodiment provides a braking mechanism that provides a large braking force with stability without generating a high stress on the door hinge (the clamping portion of the cover support). Since the present embodiment uses no link mechanism and no damper mechanism for the hinge of the opening and closing door 19, a compact braking mechanism can be disposed around the rotation axis of the opening and closing door 19. This allows an image forming apparatus that looks well when the door is opened to be provided at low cost.
In the present embodiment, the brake disk 30 is disposed at the hinge of the opening and closing door 19 of the apparatus main body 1. The same advantageous effects can be provided also in a configuration in which the brake disk 30 is disposed at the opening and closing cover. In other words, the clamping portion and the pressure member may be disposed on the opening and closing door side.
Since the configuration of the apparatus main body of the image forming apparatus according to a second embodiment is the same as that of the first embodiment, and only the configuration of the left door hinge differs, the difference from the first embodiment will be described.
When the braking force necessary for improving the operational feeling of the opening and closing door is smaller than that in the first embodiment, the braking mechanism can be further simplified.
As illustrated in the exploded view in
A hinge sliding surface 31a in
The pressure plate 32 is made of an electrogalvanized steel plate. If the strength is insufficient, a stainless steel spring material or a high-tensile steel plate may be used.
However, since the present embodiment has a simpler configuration than that of the first embodiment, stress concentrates on a notch base 31b of the door hinge frame 31. For that reason, the braking force needs to be determined in consideration of the strength of the components of the door hinge.
Furthermore, since the amount of interference varies according to the accuracy of the components of the pressure plate 32 and the door hinge frame 31, the spring constant of the pressure plate 32 needs not to be set higher than necessary.
To obtain a high braking force as in the first embodiment in the present embodiment, the door hinge frame 31 and the pressure plate 32 may be formed by insert molding. This is because the influence of dimensional errors among the components is less than that of an assembly of individually manufactured components.
Thus, the present embodiment provides an image forming apparatus in which the operability of the opening and closing door is improved at lower cost than in the first embodiment, although a large braking force as in the first embodiment is not provided. Of course, the mechanism provides a sufficient braking force using a smaller space than that of the conventional mechanisms.
In the present embodiment, the pressure plate 32 of the second embodiment is changed to a pressure spring 34, and the others are the same as those of the second embodiment, and descriptions thereof will be omitted.
The pressure spring 34 (the pressure member) is multi-formed with a steel wire. The pressure spring 34 is mounted to a door hinge frame 33 (the clamping portion of the cover support) to form the door hinge, as in the second embodiment.
The door protrusion 19b of the opening and closing door 19 is clamped under pressure by a hinge sliding surface 33a and the opposing surface to generate a braking force, thereby providing the same advantageous effects as those of the second embodiment. This mechanism of course provides a sufficient braking force with a smaller space than the conventional mechanisms.
While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the disclosure 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. 2017-217750 filed Nov. 10, 2017, and No. 2018-195911 filed Oct. 17, 2018, which are hereby incorporated by reference herein in their entirety.
Number | Date | Country | Kind |
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2017-217750 | Nov 2017 | JP | national |
2018-195911 | Oct 2018 | JP | national |
Number | Name | Date | Kind |
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20080201904 | Salice | Aug 2008 | A1 |
Number | Date | Country |
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2003-87464 | Mar 2003 | JP |
2004-45585 | Feb 2004 | JP |
2017-3892 | Jan 2017 | JP |
Number | Date | Country | |
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20190146406 A1 | May 2019 | US |