Engaging mechanism for movable panel in image forming apparatus

An image forming apparatus includes: an open/close member supported so as to be movable between an open position at which an inside of an apparatus body is exposed and a closed position at which the apparatus body is closed; an engaged portion provided on the apparatus body; an engaging member having an engaging portion that is engageable with the engaged portion and a lever portion that contacts the engaged portion to guide the engaging portion to the engaged portion when the open/close member is moved from the open position to the closed position, the engaging member being provided on the open/close member and being rotatable forward and in reverse; and an urging member that urges the engaging member. The urging direction of the urging member is changeable between fixing and releasing directions in which the engaging member is drawn into and moved away from the engaged portion, respectively.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2016-036537 filed Feb. 28, 2016.

BACKGROUND

Technical Field

SUMMARY

According to an aspect of the present invention, there is provided an image forming apparatus including: an open/close member supported so as to be movable between an open position at which an inside of an apparatus body is exposed and a closed position at which the inside of the apparatus body is covered; an engaged portion provided on one of the apparatus body and the open/close member; an engaging member having an engaging portion that is engageable with the engaged portion and a lever portion that contacts the engaged portion to guide the engaging portion to the engaged portion when the open/close member is moved from the open position to the closed position, the engaging member being provided on the other of the apparatus body and the open/close member and being rotatable forward and in reverse; and an urging member that urges the engaging member, an urging direction of the urging member being changeable between two urging directions including a fixing direction in which the engaging member is drawn into the engaged portion and a releasing direction in which the engaging member is moved away from the engaged portion.

DETAILED DESCRIPTION

An exemplary embodiment and a specific example of the present invention will be described in detail below with reference to the drawings. The present invention is not limited to the following exemplary embodiment and specific example.

It should be noted that, in the following description of the drawings, the drawings are schematic and the ratio of dimensions etc. may be different from the actual value, and that members other than those required to describe the present invention may not be illustrated as appropriate for ease of understanding.

In the drawings, in order to facilitate understanding of the following description, the front-rear direction is defined as the X-axis direction, the left-right direction is defined as the Y-axis direction, and the up-down direction is defined as the Z-axis direction.

(1) Overall Configuration and Operation of Image Forming Apparatus

FIG. 1is a schematic vertical sectional view illustrating the internal configuration of an image forming apparatus1according to an exemplary embodiment.

The overall configuration and operation of the image forming apparatus1will be described below with reference to the drawing.

The image forming apparatus1includes a control device10, a paper transport device20, a photosensitive unit30, a developing device40, a toner cartridge50, an exposure device60, a transfer device70, and a fixing device80.

An open/close member100is rotatably supported on the front surface of the image forming apparatus1. The open/close member100is opened forward (−X direction) to expose the inside of the image forming apparatus1for replacement of consumables etc.

A rear cover1bis rotatably supported on the rear surface of the image forming apparatus1. The rear cover1bis opened to expose the inside of the image forming apparatus1for an internal check for a paper jam etc.

An upper cover1c, which also serves as an ejection tray for ejection and storage of paper on which an image has been recorded, is formed on the upper surface (Z direction) of the image forming apparatus1.

The control device10includes an image forming apparatus control section11, a controller section12, an exposure control section13, a power source device14, and so forth. The image forming apparatus control section11controls operation of the image forming apparatus1. The controller section12prepares image data according to a printing process request. The exposure control section13controls lighting of a light source of the exposure device60. The power source device14applies a voltage to a charging roller32, a developing roller42, a transfer roller72, and so forth to be discussed later, and supplies power to the exposure device60.

The controller section12converts image data input from an image reading device (not illustrated) and printing information input from an external information transmission device (such as a personal computer, for example) into image information for latent image formation, and outputs a drive signal to the exposure control section13at a timing set in advance.

The paper transport device20is provided at the bottom portion of the image forming apparatus1. The paper transport device20includes a paper cassette21. A large number of sheets of paper P, which serve as a recording medium, are loaded on the upper surface of the paper cassette21. The paper P, the position of which in the width direction is determined by restriction plates (not illustrated), is drawn rearward (X direction) from above, one sheet at a time, by a paper drawing portion22, and thereafter transported to a contact portion of a registration roller pair23.

The photosensitive unit30is provided above the paper transport device20, and includes a photosensitive drum31provided in a unit housing35and rotationally driven. The charging roller32, the developing device40, the transfer roller72, and a cleaning blade34are disposed along the rotational direction of the photosensitive drum31. A cleaning roller33is disposed to face and contact the charging roller32to clean the surface of the charging roller32.

The developing device40includes a developing housing41that stores a developer inside. The developing roller42and a pair of augers44and45are disposed in the developing housing41. The developing roller42is disposed to face the photosensitive drum31. The augers44and45are provided obliquely below and on the back side of the developing roller42to agitate and transport the developer toward the developing roller42. A layer restriction roller46is disposed in proximity to the developing roller42to restrict the layer thickness of the developer.

The photosensitive unit30and the developing device40are constituted integrally as a process cartridge90. The process cartridge90is removably mounted to the body of the image forming apparatus1. As illustrated inFIG. 1, the process cartridge90may be replaced by opening and closing the open/close member100which is provided on the body of the image forming apparatus1so as to be openable and closable in the case where the photosensitive drum31reaches its end of life or the like.

The toner cartridge50is removably mounted to an end portion of the process cartridge90on the side opposite to an end portion to which the photosensitive unit30is mounted. The toner cartridge50may be mounted to and removed from the process cartridge90with the process cartridge90mounted to the body of the image forming apparatus1.

The exposure device60includes a laser beam output unit61that is usable as a light source, and a rotary multi-faceted mirror (polygon mirror)62that deflects a laser beam LB from the laser beam output unit61, and scans a surface of the photosensitive drum31with the laser beam LB which has been modulated in accordance with image data to be formed.

The surface of the photosensitive drum31which is rotatable is charged by the charging roller32. An electrostatic latent image is formed on the surface of the photosensitive drum31by the exposure device60. The electrostatic latent image formed on the photosensitive drum31is developed as a toner image by the developing roller42.

The transfer device70is composed of the rear cover1band the transfer roller72. The rear cover1bsupports the transfer roller72so that the transfer roller72comes into and out of contact with the photosensitive drum31. The transfer roller72forms a nip together with the photosensitive drum31. A transfer voltage is applied to the transfer roller72from the power source device14which is controlled by the image forming apparatus control section11. The toner image on the photosensitive drum31is transferred to the paper P which passes between the photosensitive drum31and the transfer roller72.

Residual toner remaining on the surface of the photosensitive drum31is removed by the cleaning blade34, and recovered into the unit housing35which supports the photosensitive drum31. After that, the surface of the photosensitive drum31is recharged by the charging roller32. The residue that is not removed by the cleaning blade34but attached to the charging roller32is captured by the surface of the cleaning roller33which rotates in contact with the charging roller32, and thereafter discharged onto the photosensitive drum31again by way of the charging roller32.

The fixing device80includes a pair of a heating module81and a pressurizing module82. A press contact region between the heating module81and the pressurizing module82forms a fixing nip portion (fixing region).

The paper P to which the toner image has been transferred by the transfer roller72is transported to the fixing device80by way of a transport guide74with the toner image unfixed. When the paper P is transported to the fixing device80, the toner image is fixed by the pair of the heating module81and the pressurizing module82by the action of pressure bonding and heating. After the toner image is fixed, the paper P is ejected by an ejection roller pair84to the upper cover1con the upper surface of the image forming apparatus1.

FIG. 2is a perspective view illustrating a state in which the open/close member100of the image forming apparatus1is at a closed position and engaged with the apparatus body with internal constituent members omitted.FIG. 3is a perspective view illustrating a state in which the open/close member100of the image forming apparatus1is positioned at an open position with internal constituent members omitted.FIG. 4Ais a partial perspective view illustrating a state in which the engaging member120is engaged with the engaged portion140of the apparatus body.FIGS. 4B and 4Care each a partial perspective view illustrating the state of engagement between the engaging member120and the engaged portion140.FIGS. 5A and 5Bare each a perspective view of a support member110.FIGS. 5Cand5D are each a perspective view of the engaging member120.FIGS. 5E and 5Fare each a perspective view of the engaged portion140.FIG. 6Ais a schematic sectional view illustrating the engaging member120at a release position.FIG. 6Bis a schematic sectional view illustrating the engaging member120at a fixing position. The open/close structure of the image forming apparatus1according to the exemplary embodiment will be described below with reference to the drawings.

(2.1) Overall Configuration of Open/Close Structure

InFIGS. 1 and 3, the open/close member100, which is rotatably supported on the left side of the image forming apparatus1, is supported so as to be movable between the open position at which the inside of the apparatus body is exposed and the closed position at which the inside of the apparatus body is covered.

A center of rotation100ais formed at the lower end portion of the open/close member100. The open/close member100is supported on the apparatus body so as to be rotatable about the center of rotation100a.

The engaging member120is rotatably supported by the support member110on the inner surface side of the open/close member100. The engaged portion140is fixed on the apparatus body side.

When the open/close member100is rotationally moved from the open position to the closed position, the engaging member120is engaged with the engaged portion140on the apparatus body side while rotating so that the open/close member100closes the apparatus body.

To open the apparatus body, engagement between the engaging member120and the engaged portion140on the apparatus body side is canceled by performing a drawing operation on the open/close member100to rotationally move the open/close member100to the open position.

In the exemplary embodiment, the engaging member120is provided on the open/close member100, and the engaged portion140is provided on the apparatus body side. However, the present invention is not limited thereto. The engaging member120may be provided on the apparatus body side, and the engaged portion140may be provided on the open/close member100.

(2.2) Support Member

As illustrated inFIGS. 5A and 5B, the support member110has a box shape as a whole, and has shaft receiving portions111that rotatably support rotary shaft portions123of the engaging member120. In addition, a hook portion112for attachment of one end of an urging member130is formed on the inner surface side of the support member110.

The support member110is fixed on the inner surface side of the open/close member100, and rotatably supports the engaging member120.

(2.3) Engaging Member

As illustrated inFIGS. 5C and 5D, the engaging member120has an engaging portion121to be engaged with the engaged portion140, a lever portion122that contacts the engaged portion140to guide the engaging portion121to the engaged portion140when the open/close member100is moved from the open position to the closed position, and the rotary shaft portions123, and have a hook shape as a whole.

An arcuate shape portion125and an inclined surface portion126are formed on the outer side of the engaging portion121as seen from the rotary shaft portions123. In addition, a hook portion124for attachment of the other end of the urging member130is formed on the inner surface side of the engaging portion121.

The engaging member120is urged with respect to the support member110by the urging member130with the rotary shaft portions123rotationally supported by the shaft receiving portions111of the support member110. As a result, the engaging member120is rotatably supported on the inner surface side of the open/close member100.

As illustrated inFIGS. 5E and 5F, the engaged portion140has an engaged surface141that receives the engaging portion121of the engaging member120. A notched portion142is provided at the middle portion of the engaged surface141. The urging member130, one end and the other end of which are fixed to the support member110and the engaging member120, respectively, is housed in the notched portion142when the engaging member120is rotated in the fixing direction.

The thus configured engaging member120is rotatably supported on the open/close member100via the support member110while being urged to be rotatable forward and in reverse, with the rotary shaft portions123serving as the center of rotation, by the urging member130, the urging direction of which is changeable between two directions, namely a fixing direction (fixing position), in which the engaging member120is drawn into the engaged portion140as illustrated inFIG. 6A, and a releasing direction (release position), which is opposite to the fixing direction and in which the engaging member120is moved away from the engaged portion140.

Specifically, in the case where the hook portion124of the engaging member120, to which the other end of the urging member130is attached, is positioned on the engaged portion140side with respect to an axis C1that connects the hook portion112of the support member110, to which one end of the urging member130is attached, and the rotary shaft portions123of the engaging member120to each other, the engaging member120is drawn toward the fixing position by the urging force of the urging member130.

In the case where the hook portion124of the engaging member120, to which the other end of the urging member130is attached, is positioned on the left side with respect to the axis C1, the engaging member120is urged in the direction opposite to the fixing direction by the urging force of the urging member130to be returned to the release position.

FIGS. 9A and 9Billustrate the state of engagement between an engaging member120A and an engaged portion140A according to a modification.

The engaging member120A has an engaging portion121A to be engaged with the engaged portion140A, a lever portion122A that contacts the engaged portion140A to guide the engaging portion121A to the engaged portion140A when the open/close member100is moved from the open position to the closed position, and rotary shaft portions123A, and have a hook shape as a whole.

An arcuate shape portion125A and an inclined surface portion126A are formed on the outer side of the engaging portion121A as seen from the rotary shaft portions123A. In addition, a hook portion124A for attachment of the other end of the urging member130is formed on the outer surface side of the engaging portion121A.

As illustrated inFIGS. 9A and 9B, a support member110A has a box shape as a whole, and has shaft receiving portions111A that rotatably support the rotary shaft portions123A of the engaging member120A. In addition, a hook portion112A for attachment of one end of the urging member130is formed on the outer surface side of the support member110A.

The support member110A is fixed on the inner surface side of the open/close member100, and rotatably supports the engaging member120A.

With the support member110A and the engaging member120A according to the modification, the urging member130which urges the engaging member120A in two directions, namely the fixing direction in which the engaging member120A is drawn into the engaged portion140A and the releasing direction which is opposite to the fixing direction and in which the engaging member120A is moved away from the engaged portion140A, may be easily attached from the outer side.

(3) Opening/Closing Operation of Open/Close Member

FIGS. 7A to 7Dare each a schematic view illustrating a process in which the engaging member120is engaged with the engaged portion140when the open/close member100is moved from the open position to the closed position. FIGS.8A to8G are each a schematic view illustrating a process in which the engaging member120is engaged with the engaged portion140when the open/close member100is moved from the open position to the closed position with the engaging member120rotated in the fixing direction.

The opening/closing operation of the open/close member100according to the exemplary embodiment will be described below with reference to the drawings.

(3.1) In Case where Engaging Member120is at Initial Position

As illustrated inFIG. 7A, when the open/close member100is at the open position, the engaging member120is urged in the releasing direction (at the release position) by the urging force of the urging member130. In the case where the open/close member100in such a state is subjected to a closing operation, the lever portion122of the engaging member120first contacts a front surface143of the engaged portion140along with rotational movement of the open/close member100(seeFIG. 7B).

When the closing operation on the open/close member100is further continued, the lever portion122of the engaging member120receives a rotational force from the front surface143of the engaged portion140, the engaging member120is rotated toward the engaged portion140from the release position, and the hook portion124of the engaging member120reaches a position on the axis C1(neutral position; seeFIG. 7C).

When the open/close member100is further rotationally moved, the engaging member120is drawn toward the engaged surface141of the engaged portion140by the urging force of the urging member130into the fixing position to be engaged with the engaged portion140, and the open/close member100is positioned at the closed position (seeFIG. 7D).

With the open/close structure according to the exemplary embodiment, when the lever portion122contacts one surface of the engaged portion140on the apparatus body side along with the closing operation of the open/close member100, the lever portion122is rotated toward the engaged portion140. When the hook portion124of the engaging member120is moved past the neutral position, the hook portion124is drawn toward the engaged surface141of the engaged portion140by the urging force of the urging member130.

To expose the inside of the apparatus body, the engaging member120is rotated away from the engaged portion140in the releasing direction, which is opposite to the fixing direction, by just performing a drawing operation on the open/close member100to rotationally move the open/close member100to the open position. When the hook portion124of the engaging member120is moved past the neutral position, the engaging member120is drawn back to the release position by the urging force of the urging member130to cancel engagement between the engaging member120and the engaged portion140on the apparatus body side.

(3.2) In Case where Engaging Member120is at Fixing Position

As illustrated inFIG. 8A, in the case where the open/close member100is subjected to a closing operation from a state in which the engaging member120is urged in the fixing direction (at the drawn position) by the urging force of the urging member130, the inclined surface portion126of the engaging member120first contacts an inclined surface portion144of the engaged portion140along with rotational movement of the open/close member100(seeFIG. 8B).

When the closing operation on the open/close member100is further continued, the arcuate shape portion125of the engaging member120receives a rotational force while sliding over the inclined surface portion144of the engaged portion140, the engaging member120is rotated in the direction opposite to the fixing direction, and the hook portion124of the engaging member120reaches a position on the axis C1(neutral position; seeFIG. 8C).

When the open/close member100is further rotationally moved, the engaging member120is returned to the release position by the urging force of the urging member130(seeFIG. 8D).

When the closing operation on the open/close member100is further continued, the lever portion122of the engaging member120contacts the front surface143of the engaged portion140(seeFIG. 8E) to receive a rotational force from the front surface143of the engaged portion140, the engaging member120is rotated toward the engaged portion140from the release position, and the hook portion124of the engaging member120reaches a position on the axis C1(neutral position; seeFIG. 8F).

When the open/close member100is rotationally moved, the engaging member120is drawn toward the engaged surface141of the engaged portion140by the urging force of the urging member130to be engaged with the engaged portion140, and the open/close member100is positioned at the closed position (seeFIG. 8G).

With the open/close structure according to the exemplary embodiment, even in the case where the engaging member120is positioned at the fixing position, the engaging member120is rotated in the direction opposite to the fixing direction to be returned to the release position with the arcuate shape portion125of the engaging member120receiving a rotational force while sliding as the arcuate shape portion125contacts the front surface143of the engaged portion140along with the closing operation performed on the open/close member100.