Image forming apparatus

An image forming apparatus may include a pressing assembly provided adjacent to the developing device and configured to restrict a movement of the developing device. The pressing assembly may include a rotating shaft formed to extend in a first direction and an operating unit provided at an end of the rotating shaft to be rotated along with the rotating shaft and configured to restrict the movement of the developing device in the first direction. Due to such a structure, the developing device may come into close contact in the installing direction, and also the developing roller of the developing device and the photoreceptor may come into contact with each other.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of Korean Patent Application No. 10-2014-0117002, filed on Sep. 3, 2014 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND

Embodiments of the disclosure relate to an image forming apparatus, and more particularly, to an image forming apparatus having an improved structure capable of easily installing a developing unit.

2. Description of the Related Art

An image forming apparatus generally refers to an apparatus which forms an image on a print medium according to an input signal, and may be a printer, a copy machine, a fax, and an official replicator in which these functions are integrated.

An electro-photographic image forming apparatus which is one type of image forming apparatus may include a photoreceptor unit having a photoreceptor therein, a charging unit disposed around the photoreceptor unit to charge the photoreceptor with a predetermined electric potential, a developing unit having a developing roller, and an optical scanning unit. The optical scanning unit serves to radiate light to the photoreceptor charged with the predetermined electric potential by the charging unit, and thus to form an electrostatic latent image on a surface of the photoreceptor, and the developing unit serves to supply a photosensitizer to the photoreceptor on which the electrostatic latent image is formed and thus to form a visible image.

In the case of the image forming apparatus having a structure in which the developing roller comes into contact with the photoreceptor so as to supply the photosensitizer, when a printing operation is performed, the developing roller and the photoreceptor should come into contact with each other, and also when the developing unit is replaced, the developing roller and the photoreceptor should be separated from each other to prevent interference between the developing roller and the photoreceptor.

However, the developing unit may be replaced while the developing roller and the photoreceptor come into contact with each other, and thus the developing unit or the photoreceptor may be damaged, or the image forming apparatus may be operated while the developing roller and the photoreceptor are separated from each other, and thus a defective image may be formed.

SUMMARY

Therefore, it is an aspect of the disclosure to provide an image forming apparatus in which a fixing structure of a developing device is improved.

In accordance with an aspect of the disclosure, an image forming apparatus may include a main body, a developing device formed in a first direction, and including a photoreceptor unit having a photoreceptor, and a developing unit provided adjacent to the photoreceptor and having a developing roller provided to come into contact with or be separated from the photoreceptor, and a pressing assembly provided adjacent to the developing device and configured to restrict a movement of the developing device. The pressing assembly may include a rotating shaft formed to extend in the first direction to be rotatable, and an operating unit provided at an end of the rotating shaft to be rotated along with the rotating shaft and configured to restrict the movement of the developing device in the first direction.

The operating unit may be provided to be rotated between a stand-by position and an operating position in which the operating unit is rotated from the stand-by position and supports an end of the developing device to restrict a movement of the developing device in the first direction.

The operating unit may include an operating body rotatably provided at an end of the rotating shaft, and a pressing member provided at one side of the operating body to press the developing device.

The pressing member may be formed to be more convex than the adjacent operating body.

The first direction may include an installing direction in which the photoreceptor unit is installed at the developing device seating part, and a separating direction which is opposite to the installing direction and in which the photoreceptor unit is separated from the developing device seating part, and the pressing member may include a first pressing part in which the operating unit comes into contact with the developing device while moved from the stand-by position to the operating position, and a second pressing part which extends from the first pressing part so as to more protrude in the installing direction than the first pressing part, the operating unit coming in contact with the developing device at the operating position.

The first direction may include an installing direction in which the photoreceptor unit is installed at the developing device seating part, and a separating direction which is opposite to the installing direction and in which the photoreceptor unit is separated from the developing device seating part, and the photoreceptor unit may include a to-be-pressed surface formed to be inclined, such that the photoreceptor unit is pressed in the installing direction by the operating unit while the operating unit is moved from the stand-by position to the operating position.

A movement of the rotating shaft in the first direction may be restricted by the developing device seating part.

The first direction may include an installing direction in which the photoreceptor unit is installed at the developing device seating part, and a separating direction which is opposite to the installing direction and in which the photoreceptor unit is separated from the developing device seating part, and the operating unit may further include an operation elastic part configured to press the operating body in the installing direction.

The operation elastic part may include a fastening member provided at one end of the rotating shaft to have a component vertical to a rotating axis of the rotating shaft, and an installation elastic member of which one end is supported by the fastening member, and the other end presses the operating unit in the installing direction.

The operating unit may be pressed in the installing direction by the installation elastic member, and a movement of the operating unit in the separating direction may be restricted by the fastening member.

The operating unit may further include an installing space formed at an inner side of the operating body so that the operation elastic part is installed therein, and the installing space may include a first installing space in which the installation elastic member is installed to extend or be compressed, and a second installing space which is formed using a movement restricting surface configured to restrict a movement of the operating unit in the separating direction as a boundary line and in which the fastening member is installed.

The pressing assembly may further include at least one pressing unit configured to press the developing unit so that the developing roller and the photoreceptor come into close contact with each other, and provided to be interlocked with the operating unit.

The operating unit may press the photoreceptor unit in the first direction while moved from the stand-by position to the operating position, and the at least one pressing unit may be interlocked with the movement of the operating unit from the stand-by position to the operating position, and presses the developing unit in a second direction vertical to the first direction.

The at least one pressing unit may include a link unit configured to convert rotating motion of the rotating shaft due to rotation of the operating unit into linear reciprocating motion, and a pressing part connected with the link unit so as to press the developing device.

The link unit may include a first link member rotated along with the rotating shaft, and a second link member of which one end is connected with an end of the first link and the other end linearly reciprocates.

The at least one pressing unit may include a plurality of pressing units disposed at the rotating shaft to be spaced apart from each other.

The link unit may include a pressing elastic member provided at the second link member to generate a pressing force of the pressing unit.

The second link member may include a stopper insertion part of which at least a part is inserted into the pressing part depending on a position of the pressing unit, and a variable seating part which is disposed adjacent to the stopper insertion part, and in which the pressing elastic member is seated thereon, and with which a length of the pressing elastic member is interlocked and varied so that the pressing force of the pressing elastic member is varied.

One end of the pressing elastic member may be supported by an end of the second link member, and the other end thereof may be supported by the pressing part.

The pressing elastic member may be compressed to a maximally compressed length ML, when the operating unit is disposed between the operating position and the stand-by position.

In accordance with an aspect of the disclosure, an image forming apparatus may include a main body, a developing device including a photoreceptor unit having a photoreceptor, and a developing unit provided adjacent to the photoreceptor and having a developing roller provided to come into contact with or be separated from the photoreceptor, and a pressing assembly provided adjacent to the developing device, wherein the pressing assembly may include a pressing unit configured to press the developing unit so that the developing roller and the photoreceptor come into contact with each other, and an operating unit provided to be moved between an operating position in which a pressing force is generated from the pressing unit and a stand-by position in which the pressing force is released, and also to restrict a movement of the developing device.

A first direction may be a lengthwise direction of the developing device, and the operating unit may press the developing device in the first direction, and the pressing unit may press the developing unit in a second direction vertical to the first direction.

A pressing operation of the operating unit in the first direction with respect to the developing device, and a pressing operation of the pressing unit in the second direction with respect to the developing unit may be performed simultaneously.

The operating unit may include an operating body rotatably provided at an end of a rotating shaft, and a pressing member provided at one side of the operating body to press the developing device.

The pressing member may be formed to be more convex than the adjacent operating body.

The first direction may include an installing direction in which the photoreceptor unit is installed at the developing device seating part, and a separating direction which is opposite to the installing direction and in which the photoreceptor unit is separated from the developing device seating part, and the pressing member may include a first pressing part in which the operating unit comes into contact with the developing device while moved from the stand-by position to the operating position, and a second pressing part which extends from the first pressing part so as to more protrude in the installing direction than the first pressing part, the operating unit coming in contact with the developing device at the operating position.

The first direction may include an installing direction in which the photoreceptor unit is installed at the developing device seating part, and a separating direction which is opposite to the installing direction and in which the photoreceptor unit is separated from the developing device seating part, and the photoreceptor unit may include a to-be-pressed surface formed to be inclined, such that the photoreceptor unit is pressed in the installing direction by the operating unit while the operating unit is moved from the stand-by position to the operating position.

The pressing assembly may further include a rotating shaft configured to extend in the first direction so as to transmit an operation of the operating unit to the pressing unit.

A movement of the rotating shaft in the first direction may be restricted by the developing device seating part.

The first direction may include an installing direction in which the photoreceptor unit is installed at the developing device seating part, and a separating direction which is opposite to the installing direction and in which the photoreceptor unit is separated from the developing device seating part, and the operation unit may further include an operating elastic part configured to press the operating body in the installing direction.

The operation elastic part may include a fastening member provided at one end of the rotating shaft to have a component vertical to a rotating axis of the rotating shaft, and an installation elastic member of which one end is supported by the fastening member, and the other end presses the operating unit in the installing direction.

The operating unit may be pressed in the installing direction by the installation elastic member, and a movement of the operating unit in the separating direction may be restricted by the fastening member.

The operating unit may further include an installing space formed at an inner side of the operating body so that the operation elastic part is installed therein, and the installing space may include a first installing space in which the installation elastic member is installed to extend or be compressed, and a second installing space which is formed using a movement restricting surface configured to restrict a movement of the operating unit in the separating direction as a boundary line and in which the fastening member is installed.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Embodiments are described below to explain the disclosure by referring to the figures.

An image forming apparatus in accordance with an embodiment of the disclosure will be described.

FIG. 1is a cross-sectional view of the image forming apparatus in accordance with an embodiment of the disclosure.

As illustrated inFIG. 1, the image forming apparatus1may include a main body10, a print medium supplying device20which stores and feeds a print medium S, a developing device30which forms an image on the print medium S supplied through the print medium supplying device20, a toner device40which supplies toner to the developing device30, an optical scanning device50which forms an electrostatic latent image on a photoreceptor32of the developing device30, a fixing device60which fixes a toner image transferred on the print medium S to the print medium S, and a discharging device70which discharges the print medium S on which an image forming is completed.

The print medium supplying device20which stores and feeds the print medium S is provided at a lower portion of the main body10to supply the print medium S toward the developing device30.

The print medium supplying device20may include a print medium cassette21which is coupled to the main body10to be opened and closed and thus to store the print medium S, and a transporting member25which picks up each sheet of the print medium S stored in the print medium cassette21and transports it toward the developing device30.

One end of the print medium cassette21may be rotatably coupled so as to guide the print medium S stored therein toward the transporting member25, and the other end thereof may have a knock-up plate23supported by a pressing spring22.

The transporting member25may include a pick-up roller27which picks up each sheet of the print medium S loaded on the knock-up plate23, and a feed roller28which transports the print medium S picked up by the pick-up roller27toward the developing device30.

The developing device30may include a housing31which defines an exterior thereof, the photoreceptor32which is rotatably coupled in the housing31to form the electrostatic latent image, stirring screws33aand33bwhich stir the toner supplied from the toner device40, a developing roller34which supplies the toner stirred by the stirring screws33aand33bto the photoreceptor32, and a charging member35which charges the photoreceptor32.

The toner supplied from the toner device40is introduced into the housing31, and then stirred and transported to one side of the housing31by the stirring screws33aand33b. The stirred and transported toner may be supplied to the photoreceptor32by the developing roller34so as to form the visible image.

The photoreceptor32comes into contact with a transfer roller14so as to form a transfer nip N1, such that the toner supplied to the photoreceptor32and forming the visible image is transferred on the print medium S. The transfer roller14may be rotatably disposed in the main body10.

The toner device40may be coupled with the developing device30so as to receive and store the toner which forms an image on the print medium S and also to supply the toner to the developing device30when the image forming operation is performed.

The optical scanning device50radiates light including image information onto the photoreceptor32so as to form the electrostatic latent image on the photoreceptor32.

The fixing device60may include a housing62, a heating member64, and a pressing member66which are rotatably disposed in the housing62.

The print medium S on which the toner image is transferred passes between the heating member64and the pressing member66. At this time, the toner image is fixed to the print medium S by heat and pressure.

The heating member64is rotated while engaged with the pressing member66, forms a fixing nip N2with the pressing member66, and heated by a heating source68so as to transfer heat to the print medium S passing through the fixing nip N2. The heating member64may be a heating roller which receives power from a driving source (not shown) so as to be rotated. The heating source68which applies the heat to the print medium S on which the toner is transferred may be disposed at an inner side of the heating member64. A halogen lamp may be used as the heating source68. However, an electro-thermal wire, an induction heater, or the like may be also used as the heating source68.

The pressing member66may be disposed to come into contact with an outer circumferential surface of the heating member64, such that the fixing nip N2is formed between the pressing member66and the heating member64. The heating member64may be a pressing roller which receives power from a driving source (not shown) to be rotated.

The discharging device70may include a first discharging roller71and a second discharging roller72which are engaged with each other so as to discharge the print medium S passing through the fixing device60to an outside of the main body10.

FIG. 2is a view illustrating the developing device and a cover unit of the image forming apparatus in accordance with an embodiment of the disclosure, andFIG. 3is a view illustrating a coupling of the developing device and the cover unit of the image forming apparatus in accordance with an embodiment of the disclosure.

The developing device30may be provided to be seated on a developing device seating part5. A waste toner storing unit in which waste toner generated from the developing device30is stored may be provided at one side of the developing device30. The toner used in the developing device30may be moved to the waste toner storing unit and then stored in the waste toner storing unit. In an embodiment of the disclosure, the waste toner storing unit may be referred to as a cover unit170.

A pressing assembly100(seeFIGS. 6A to 7C) may be provided at one side of the developing device30so that a developing unit30aand a photoreceptor unit30bcome into close contact with each other. Specifically, the developing roller34of the developing unit30aand the photoreceptor32of the photoreceptor unit30bmay be provided to come into close contact with or separated from each other by an operation of the pressing assembly100.

A guide rib174which guides the operation of the pressing assembly100may be provided at the cover unit170.

The relationship between the pressing assembly100and the guide rib174and the structures thereof will be described below.

FIGS. 4A and 4Bare views respectively illustrating the operation of the pressing assembly and the developing unit in accordance with an embodiment of the disclosure,FIGS. 5A, 5B, and 5Care views illustrating the operation of the pressing assembly in accordance with an embodiment of the disclosure,FIGS. 6A and 6Bare views illustrating the pressing assembly in accordance with an embodiment of the disclosure, andFIGS. 7A, 7B, and 7Care cross-sectional views of the pressing unit depending on the operation of the pressing assembly in accordance with an embodiment of the disclosure.

The pressing assembly100is disposed adjacent to the developing device30, such that the developing unit30aand the photoreceptor unit30bcome into close contact with or are separated from each other. Specifically, the pressing assembly100is provided so that the developing roller34of the developing unit30aand the photoreceptor32of the photoreceptor unit30bcome into close contact with or are separated from each other. An arrangement of the pressing assembly100is not limited. However, in the embodiment of the disclosure, the pressing assembly100is disposed at the developing device seating part5.

The pressing assembly100may include a rotating shaft110, a pressing unit120, and an operating unit150.

The rotating shaft110may be rotatably provided so that an operation of the operating unit150is transmitted to the pressing unit120. Assuming that a lengthwise direction of the developing device30, the developing unit30a, and the photoreceptor unit30bis a first direction W1, the rotating shaft110may be formed to be elongated in the first direction W1. The first direction W1may be defined as a direction vertical or perpendicular (substantially vertical or perpendicular) to a moving direction of the print medium. The rotating shaft110may serve as a rotating center of the operating unit150to be described below.

The rotating shaft110may be disposed in the first direction W1, and may be provided so that a movement thereof in the first direction W1is restricted. The rotating shaft110may be provided to be rotatable about a rotating axis. At least one shaft stopper111may be provided at an outer circumferential surface of the rotating shaft110so that the movement of the rotating shaft110in the first direction W1is restricted.

The pressing unit120is provided so that the developing roller34and the photoreceptor32come into close contact with each other. Specifically, the pressing unit120is provided so as to press the developing unit30a, such that the developing roller34and the photoreceptor32come into close contact with or are separated from each other. The pressing unit120may be disposed on the rotating shaft110, and may be provided to receive the operation of the operating unit150through the rotating shaft110and thus to be operated.

The pressing unit120may be provided to be interlocked with the operating unit150. At least one pressing unit120may be provided. By such a structure, at least one pressing unit120may be provided to be interlocked with the operating unit150. In the case in which a plurality of pressing units120are provided, the plurality of pressing units120may be disposed on the rotating shaft110to be spaced apart from each other. As an example, the plurality of pressing units120may be disposed on the rotating shaft110to be spaced apart at regular intervals from each other, such that the same pressing force is distributed in the first direction W1, and thus the developing unit30ais pressed by an uniform pressing force, regardless of a position in a lengthwise direction thereof.

The pressing unit120may be provided to be moved between a pressing position P1(see, e.g.,FIG. 4AandFIG. 7A) in which the developing roller34and the photoreceptor32come into contact with each other, and a releasing position P2(see, e.g.,FIG. 4BandFIG. 7B) which is moved back from the pressing position P1so that the developing roller34and the photoreceptor32are separated from each other. Specifically, when the pressing unit120is located at the pressing position P1, the developing unit30ais pressed by the pressing unit120, and thus the developing roller34and the photoreceptor32come into contact with each other. Also, when the pressing unit120is located at the releasing position P2, the pressing of the pressing unit120with respect to the developing unit30ais released, and thus the developing roller34and the photoreceptor32are separated from each other.

The operating unit150may be rotatably provided so that the pressing unit120is operated by the operation of the operating unit150. That is, at least one pressing unit120is provided to be interlocked with the operating unit150.

The operating unit150may include an operating body152which is connected with the rotating shaft110so as to be rotated about the rotating shaft110.

The operating unit150may be provided to be movable between an operating position01in which a pressing force is generated from the pressing unit120and a stand-by position02in which the pressing force is released.

When the operating unit150is located at the operating position01, the pressing unit120presses the developing unit, and when the operating unit150is located at the stand-by position02, the pressing of the pressing unit120with respect to the developing unit30ais released.

The operating position01of the operating unit150may include a fixed operating position01aand a movable operating position01b.

In the fixed operating position01a, the pressing unit120may be continuously located at the pressing position P1, and in the movable operating position01b, the pressing unit120may be movably located at the pressing position P1. In the fixed operating position01a, the operating unit150may be moved to the movable operating position01bor the stand-by position02, only when an external force is applied. In the movable operating position01b, the operating unit150may be moved to the stand-by position02without the external force.

When the operating unit150is located at the fixed operating position01aand the movable operating position01b, the pressing force generated at the pressing unit120interlocked with the operating unit150may be the same.

The pressing unit120may include a link unit130and a pressing part140.

The link unit130serves to convert rotating motion of the rotating shaft110generated by the operation of the operating unit150into linear motion.

The link unit130may include a first link member131and a second link member132.

One end of the first link member131is coupled to the rotating shaft110so as to be rotated along with rotation of the rotating shaft110. Due to such a structure, a rotating center of the first link member131is provided to coincide with that of the rotating shaft110.

At least a part of the link unit130is disposed at an inner side of the developing device seating part5so that rotation of the first link member131is partly limited by an inner wall of the developing device seating part5. This will be described below in detail.

One end of the second link member132is connected with an end of the first link member131, and the other end thereof is provided to linearly reciprocate.

The pressing part140is provided at the other end of the second link member132so as to reciprocate depending on the linear reciprocating motion of the other end of the second link member132.

Rotation of the operating unit150is transmitted to the first link member131by the rotating shaft110, and the rotation of the first link member131is converted into the linear reciprocating motion of the other end of the second link member132. The pressing part140presses the developing unit30a, while reciprocating linearly through the motion of the other end of the second link member132, and thus the developing roller34and the photoreceptor32may come into contact with each other.

The link unit130may include a pressing elastic member134.

The pressing elastic member134may be provided to generate an elastic force depending on the motion of the pressing unit120. That is, the pressing elastic member134may be provided to extend or be compressed depending on the motion of the pressing unit120, and thus to provide the elastic force to the pressing unit120.

The pressing elastic member134may be disposed to have a component in a direction opposite to a rotating direction of the rotating shaft110. That is, the pressing elastic member134may be provided to apply an elastic force that has a component of direction opposite to a moving direction of one end of the first link member131when the first link member131is rotated by the rotation of the rotating shaft110.

The pressing part140may include a pressing body142and a pressing movement rail146.

A pressing surface142amay be provided at a front portion of the pressing body142. The pressing surface142amay be provided to come into direct contact with the developing unit30aand thus to press the developing unit30a.

The pressing body142may be provided at an end of the second link member132so as to be interlocked with an operation of the second link member132.

Specifically, a stopper pin133which is formed perpendicular to a lengthwise direction of the second link member132may be provided at the end of the second link member132. A stopper moving part143through which the stopper pin133is moved may be formed at the pressing body142.

The pressing part140may include a stopper rib144which is provided to limit a movement of the stopper pin133in the stopper moving part143. The stopper rib144may be provided on the pressing body142. The stopper rib144may be provided to catch the stopper pin133, when the pressing unit120is moved back from the pressing position P1to the stand-by position02. Due to such a structure, when the pressing unit120is moved from the stand-by position02to the pressing position P1, the second link member132does not affect the pressing part140, but when the pressing unit120is moved back from the pressing position P1to the stand-by position02, the stopper pin133of the second link member132is caught by the stopper rib144, and thus the pressing part140is moved back.

The second link member132may include a stopper insertion part132aand a variable seating part132b.

The stopper insertion part132aof the second link member132is a part which is inserted into the stopper moving part143of the pressing part140by the operation of the pressing unit120.

The variable seating part132bof the second link member132is provided so that the pressing elastic member134is seated thereon. The variable seating part132brefers to the remaining parts of the second link member132, except the stopper insertion part132a. That is, the variable seating part132bmay be the parts of the second link member132, which are formed between one surface of the stopper rib144and the end of the second link member132.

A length of the second link member132may be formed to be the same as a sum of a length of the variable seating part132band a length of the stopper insertion part132a. The lengths of the variable seating part132band the stopper insertion part132amay be changed depending on the operation of the pressing unit120, and may be provided so that the sum of the lengths of the variable seating part132band the stopper insertion part132ais the same as the length of the second link member132.

Since the length of the variable seating part132bis changed depending on the operation of the pressing unit120, a length of the pressing elastic member134provided at the variable seating part132bis also changed. That is, since the length of the variable seating part132bis changed depending on the operation of the pressing unit120, the length of the pressing elastic member134is also changed depending on the operation of the pressing unit120. Since a change in the length of the pressing elastic member134means a change in the elastic force, the elastic force of the pressing elastic member134is changed depending on the operation of the pressing unit120.

Due to such a structure, when the pressing unit120is moved from the stand-by position02to the pressing position P1, the length of the variable seating part132bis reduced, and thus the elastic force of the pressing elastic member134provided at the variable seating part132bis applied to one surface of the stopper rib144of the pressing body142, and the pressing part140is moved in a direction in which the pressing part140presses the developing unit30a. Contrarily, when the pressing unit120is moved from the pressing position P1to the stand-by position02, the length of the variable seating part132bis increased, and thus the elastic force of the pressing elastic member134provided at the variable seating part132bis also reduced, and the pressing part140is moved back in a direction opposite to the direction in which the pressing part140presses the developing unit30a, while the stopper pin133of the second link member132is caught by the stopper rib144.

The pressing movement rail146is provided at the pressing body142so that the pressing part140reciprocates linearly. Specifically, a moving protrusion147is provided at the developing device seating part5to correspond to the pressing movement rail146, and the pressing movement rail146is provided to be moved along the moving protrusion147.

One pair of pressing movement rails146is provided up and down at both side surfaces of the pressing body142, respectively, such that the moving protrusion147is inserted therebetween. A protrusion insertion part146amay be formed between one pair of pressing movement rails146so that the moving protrusion147is inserted therein.

The rotating motions of the operating unit150and the rotating shaft110are transmitted to the pressing part140by the first and second link members131and132, and converted into the linear reciprocating motion at the pressing part140by the pressing movement rail146and the moving protrusion147.

The pressing elastic member134may be provided so that a compressed length thereof differs according to a state of the operating unit150. As described above, this is because the length of the variable seating part132bis changed depending on the operation of the pressing unit120, and thus the length of the pressing elastic member134provided at the variable seating part132bdiffers.

Specifically, when the operating unit150may be at the stand-by position02, the length of the pressing elastic member134is a first length L1, and when the operating unit150is at the fixed operating position01a, the length of the pressing elastic member134may be a second length L2, and when the operating unit150is at the movable operating position01b, the length of the pressing elastic member134may be a third length L3.

When the pressing elastic member134has the first length L1, the pressing elastic member134may be in a state which does not extend or is not compressed. When the pressing elastic member134has the second length L2and the third length L3, the pressing elastic member134may be in a state which is compressed so that the elastic force is applied to the pressing elastic member134. That is, the second length L2and the third length L3are provided to be shorter than the first length L1.

The second length L2and the third length L3may be the same so that a pressing force generated when the operating unit150is at the fixed operating position01ais the same as that generated when the operating unit150is at the movable operating position01b.

The pressing elastic member134may be provided to be maximally compressed, when the operating unit150is located between the fixed operating position01aand the movable operating position01b. That is, the pressing elastic member134is compressed to have a maximum compressed length ML, when the operating unit150is moved between the fixed operating position01aand the movable operating position01b.

Therefore, in order to move the operating unit150from the fixed operating position01ato the movable operating position01bor the stand-by position02, an external force by which the pressing elastic member134is compressed from the second length L2to a maximally compressed length ML should be applied. Also, the movement of the operating unit150from the movable operating position01bto the stand-by position02may be performed without the external force by which the pressing elastic member134is compressed to the maximally compressed length ML, while the pressing elastic member134is elastically returned from the third length L3to the first length L1.

An operation restricting surface6amay be provided above the link unit130so as to restrict an operation of the link unit130. The operation restricting surface6amay be provided at the developing device seating part5to face an upper portion of the link unit130. Specifically, the developing device seating part5may include an assembly cover6which covers at least a part of the pressing assembly100. The rotating shaft110and at least a part of the pressing unit120may be disposed at an inner side of the assembly cover6. The operation restricting surface6awhich faces the link unit130may be provided at the inner side of the assembly cover6, and the operation of the link unit130is partly restricted by the operation restricting surface6a.

This will be described with the operating unit150.

When the operating unit150is at the fixed operating position01a, the end of the first link member131of the link unit130is in a state in which rotation thereof in one direction is restricted by the operation restricting surface6a. At this time, since a compressed elastic force of the pressing elastic member134provided at the second link member132is applied in the other direction, the operating unit150may be fixed at the fixed operating position01a.

FIG. 8Ais a view illustrating the cover unit in accordance with an embodiment of the disclosure, andFIG. 8Bis an enlarged view of a portion A ofFIG. 8A.

The cover unit170may be detachably provided at one side of the developing device30. The cover unit170may be provided so that the operation of the operating unit150is interlocked with an attachment and detachment thereof. Specifically, while the cover unit170is installed at the one side of the developing device30, the cover unit170may guide the operating unit150located at the stand-by position02or the fixed operating position01ato the movable operating position01b.

The cover unit170may include a cover body172and a guide rib174.

The cover body172may be provided to cover one side of the developing device30, and may be connected with the developing device30so that the waste toner generated from the developing device30is stored therein.

The guide rib174may be provided at one surface of the cover body172, which faces the developing device30, so as to guide the rotation of the operating unit150.

The guide rib174may include a first guide rib175and a second guide rib176. The first guide rib175serves to guide the operating unit150which is moved from the fixed operating position01ato the movable operating position01b, and the second guide rib176serves to guide the operating unit150which is moved from the stand-by position02to the movable operating position01b.

The cover unit170may include an operating unit seating part178. The operating unit seating part178may be provided at an end of the guide rib174so as to locate the operating unit150at the movable operating position01bwhen the cover unit170is installed at the one side of the developing device30. In an embodiment, the operating unit seating part178may be provided between the first guide rib175and the second guide rib176, and the operating unit150may be guided from the fixed operating position01aor the stand-by position02by the guide rib174so as to be located at the movable operating position01bcorresponding to the operating unit seating part178.

The guide rib174may be formed so that an end thereof is inclined toward the operating unit seating part178. Due to such a structure, when the cover unit170is coupled to the one side of the developing device30, the operating unit150may be rotated and seated on the operating unit seating part178corresponding to the movable operating position01b.

Specifically, the guide rib174may include a first rib contact part174a, and a second rib contact part174bwhich is spaced apart a predetermined angle from the first rib contact part174awith respect to the rotating center of the operating unit150and extends from the first rib contact part174aso as to have a slope inclined toward the cover body172.

The operating unit150may include an operating body152, and a first guide surface152aand a second guide surface152bwhich are provided at the operating body152.

The first guide surface152amay be provided to be guided by the first guide rib175, and may be provided at an upper portion of the operating body152. Specifically, the first guide surface152amay be provided at an upper edge of the operating body152so as to be guided from the first rib contact part174aof the first guide rib175to the second rib contact part174bthereof.

The second guide surface152bmay be provided to be guided by the second guide rib176, and may be provided at a lower portion of the operating body152. Specifically, the second guide surface152bmay be provided at a lower edge of the operating body152so as to be guided from the first rib contact part174aof the second guide rib176to the second rib contact part174bthereof.

Hereinafter, an operation of the image forming apparatus in accordance with an embodiment of the disclosure will be described.

To perform a printing operation after the developing device30is seated on the developing device seating part5, the developing unit30aand the photoreceptor unit30bshould come into close contact with each other so that the developing roller34and the photoreceptor32come into contact with each other.

The pressing assembly100is operated so that the developing unit30aand the photoreceptor unit30bshould come into close contact with each other.

In the initial stage, the operating unit150is at the stand-by position02, and when the developing device30is seated on the developing device seating part5, the operating unit150is rotated so that the pressing unit120presses the developing unit30a.

When the operating unit150is rotated from the stand-by position02to the fixed operating position01aor the movable operating position01b, the link unit130of the pressing unit120is operated, and the pressing part140presses the developing unit30a. The pressed developing unit30acomes into close contact with the photoreceptor unit30b, and the developing roller34and the photoreceptor32come into contact with each other.

As described above, the operating unit150may be arbitrarily moved from the stand-by position02to the fixed operating position01aor the movable operating position01bso that the developing unit30aand the photoreceptor unit30bshould come into close contact with each other. By installing the cover unit170at the one side of the developing device30, the operating unit150may be provided to be moved to the operating position01.

When the cover unit170is installed at the one side of the developing device30, the operating unit150is moved to the movable operating position01b, regardless of the position of the operating unit150.

Specifically, in the case in which the operating unit150is at the fixed operating position01a, when the cover unit170is installed at the one side of the developing device30, the operating unit150is guided by the first guide rib175of the cover unit170, and moved to the movable operating position01b. Also, in the case in which the operating unit150is at the stand-by position02, when the cover unit170is installed at the one side of the developing device30, the operating unit150is guided by the second guide rib176of the cover unit170, and moved to the movable operating position01b. The operating unit guided by the first guide rib175or the second guide rib176is seated on the operating unit seating part178, and maintained at the movable operating position01b.

Of course, in the case in which the operating unit150is at the movable operating position01b, when the cover unit170is installed at the one side of the developing device30, the operating unit150is seated on the operating unit seating part178, and maintained at the movable operating position01b.

When the cover unit170is separated from the developing device30to replace the developing device30, the operating unit150located at the movable operating position01bis rotated to the stand-by position02by an elastic returning force of the pressing elastic member134. As the operating unit150is rotated to the stand-by position02, the pressing force of the pressing unit120applied to the developing unit30ais released, and the developing roller34and the photoreceptor32are separated from each other.

Hereinafter, an image forming apparatus in accordance with an embodiment of the disclosure will be described.

Repeated description of the same structure as that previously described above will be omitted.

FIG. 9is a cross-sectional view of the image forming apparatus in accordance with an embodiment of the disclosure.

As illustrated inFIG. 9, the image forming apparatus1001may include a main body1010, a print medium supplying unit1020, an optical scanning unit1030, a developing device1040, a transfer unit1060, a fixing unit1070, and a print medium discharging unit1080.

The main body1010defines an exterior of the image forming apparatus1001, and also supports various components installed therein. Further, a cover1011may be rotatably installed at one side of the main body1010. The cover1011serves to open and close a part of the main body1010. A user may open the cover1011, may have access to an inner side of the main body1010, and may remove paper jammed in a printing path.

The print medium supplying unit1020may include a cassette1021in which a print medium S is stored, a pick-up roller1022which picks up each sheet of the print medium S stored in the cassette1021, and a transporting roller1023which transports the picked-up print medium toward the transfer unit1060.

The optical scanning unit1030may be disposed under a developing device1040to radiate light corresponding to image information onto a photoreceptor1052and thus to form an electrostatic latent image on a surface of the photoreceptor1052. The optical scanning unit1030may include a light source1032which generates the light, a plurality of reflection mirrors1034which change a route of the light generated from the light source1032, and a plurality of optical windows1036through which the light reflected by the plurality of reflection mirrors1034is transmitted.

The developing device1040may include a developing unit1041and a photoreceptor unit1050.

Developing units1041Y,1041M,1041C and1041K which receive yellow (Y), magenta (M), cyan (C) and black (K) developers, respectively, have a developing roller1042and supplying rollers1044and1046, respectively. The supplying rollers1044and1046serve to supply the developers to the developing roller1042, and the developing roller1042serves to attach the developers on the surface of the photoreceptor on which the electrostatic latent image is formed and thus to form a visible image.

Each photoreceptor unit1050Y,1050M,1050C, or1050K corresponding to each developing unit1041Y,1041M,1041C, or1041K has a photoreceptor1052and a charger1054. The charger1054serves to charge the photoreceptor1052with a predetermined electric potential, and the electrostatic latent image is formed on the surface of the charged photoreceptor1052.

The transfer unit1060may include a transfer belt1061which is in contact with the photoreceptor1052of each photoreceptor unit1050Y,1050M,1050C, or1050K while being circulated, a driving roller1063which drives the transfer belt1061, a tension roller1065which provides a predetermined tensile force to the transfer belt1061, and four rollers1067which transfer the visible image developed on the photoreceptor1052of each photoreceptor unit1050Y,1050M,1050C, or1050K to the print medium P.

The fixing unit1070may include a heating roller1071which has a heating source, and a pressing roller1072which is installed so as to face the heating roller1071. When the print medium passes between the heating roller1071and the pressing roller1072, the image is fixed on the print medium by heat transmitted from the heating roller1071and pressure acting between the heating roller1071and the pressing roller1072.

The print medium discharging unit1080has a plurality of discharging rollers1081so as to discharge the print medium passing through the fixing unit1070to an outside of the main body1010.

Each photoreceptor unit1050Y,1050M,1050C, or1050K may be fixed to an inner side of the main body1010, and each developing unit1041Y,1041M,1041C, or1041K may be provided to be attached or detached through one side of the main body1010. When each developing unit1041Y,1041M,1041C, or1041K is installed at the main body1010, each developing unit1041Y,1041M,1041C, or1041K is coupled to each photoreceptor unit1050Y,1050M,1050C, or1050K so as to be rotated about each rotating center CY, CM, CC, or CK. The developing rollers1042included in each developing unit1041Y,1041M,1041C, or1041K and the photoreceptors1052included in each photoreceptor unit1050Y,1050M,1050C, or1050K come into contact with each other, when the image forming apparatus1001performs the printing operation, and then are separated from each other, when each developing unit1041Y,1041M,1041C, or1041K is detached and replaced. Hereinafter, a structure in which the developing rollers1042and the photoreceptors1052are in contact with or separated from each other will be described in detail.

FIG. 10is a view illustrating an arrangement of the developing device and the optical scanning unit of the image forming apparatus in accordance with a second embodiment of the disclosure.

The developing device1040may be provided to be seated on a developing device seating part1005. A waste toner storing unit (not shown) which stores waste toner generated from the developing device1040may be provided at one side of the developing device1040. Toner used in the developing device1040may be provided to be moved to the waste toner storing unit and then stored therein. In an embodiment of the disclosure, the waste toner storing unit may be referred to as a cover unit. The cover unit may be provided to guide an operation of an operating unit250, as described previously. The description of this structure will be omitted below for the sake of brevity.

A pressing assembly200may be provided at one side of the developing device1040so that the developing unit1041and the photoreceptor unit1050come into close contact with each other. Specifically, the developing roller1042of the developing unit1041and the photoreceptor1052of the photoreceptor unit1050may come into close contact with or be separated from each other through an operation of the pressing assembly200.

FIGS. 11A and 11Bare views illustrating the operation of the pressing assembly and the developing device in accordance with an embodiment of the disclosure,FIGS. 12A and 12Bare perspective views illustrating the operation of the pressing assembly in accordance with an embodiment of the disclosure,FIGS. 13A and 13Bare cross-sectional views illustrating a pressing unit depending on the operation of the pressing assembly in accordance with an embodiment of the disclosure, andFIGS. 14A and 14Bare cross-sectional views illustrating a shutter unit and the developing unit depending on the operation of the pressing assembly in accordance with an embodiment of the disclosure.

The pressing assembly200may be disposed adjacent to the developing device1040so that the developing unit1041and the photoreceptor unit1050come into contact with or are separated from each other. Specifically, the pressing assembly200may be provided so that the developing roller1042of the developing unit1041and the photoreceptor1052of the photoreceptor unit1050come into contact with or are separated from each other. An arrangement of the pressing assembly200is not limited. However, in an embodiment, the pressing assembly200may be disposed at the developing device seating part1005.

The pressing assembly200may include a rotating shaft210, a pressing unit220, and an operating unit250.

The rotating shaft210may be rotatably provided so that an operation of the operating unit250is transmitted to the pressing unit220. At least one shaft stopper211may be provided at an outer circumferential surface of the rotating shaft210so that a movement of the rotating shaft210in a first direction W1is restricted.

The pressing unit220may be provided so that the developing roller1042and the photoreceptor1052come into close contact with each other. The pressing unit220may be provided to be interlocked with the operating unit250. The pressing unit220may be provided to be moved between a pressing position P1in which the developing roller1042and the photoreceptor1052come into contact with each other, and a releasing position P2which is moved backed from the pressing position P1so that the developing roller1042and the photoreceptor1052are separated from each other.

The operating unit250may be provided to be rotatable, such that the pressing unit220is operated by the operation of the operating unit250. That is, at least one pressing unit220may be provided to be interlocked with the operating unit250.

The operating unit250may include an operating body252which is connected with the rotating shaft210so as to be rotated about the rotating shaft210.

The operating unit250may be provided to be movable between an operating position01in which a pressing force is generated from the pressing unit220and a stand-by position02in which the pressing force is released.

The pressing unit220may include a link unit230and a pressing part240.

The link unit230may include a first link member231, a second link member232, and a pressing elastic member234. The second link member232may include a stopper insertion part232aand a variable seating part232b. A stopper pin233which is formed perpendicular to a lengthwise direction of the second link member232may be provided at an end of the second link member232.

The pressing elastic member234may be provided to be maximally compressed, when the operating unit250is located between the operating position01and the stand-by position02. That is, the pressing elastic member234may be compressed to a maximum compressed length ML, when the operating unit250is moved between the operating position01and the stand-by position02.

An operation restricting surface1006amay be provided above the link unit230so as to restrict an operation of the link unit230. The operation restricting surface1006amay be provided at an assembly cover1006of the developing device seating part1005to face an upper portion of the link unit230.

The pressing part240may include a pressing body242and a pressing movement rail246. A pressing surface242ais provided at a front portion of the pressing body242. The pressing surface242amay be provided to come into direct contact with the developing unit1041and thus to press the developing unit1041. A stopper moving part243through which the stopper pin233is moved is formed at the pressing body242. The pressing part240may include a stopper rib244which is provided to limit a movement of the stopper pin233in the stopper moving part243. The stopper rib244may be provided on the pressing body242.

The pressing movement rail246is provided at the pressing body242so that the pressing part240reciprocates linearly. Specifically, a moving protrusion (not shown) is provided at the developing device seating part1005to correspond to the pressing movement rail246, and the pressing movement rail246is provided to be moved along the moving protrusion.

One pair of pressing movement rails246may be provided up and down at both side surfaces of the pressing body242, respectively, such that the moving protrusion is inserted therebetween. A protrusion insertion part246amay be formed between one pair of pressing movement rails246so that the moving protrusion is inserted therein.

The pressing part240may include a shutter guide member248.

The shutter guide member248may be provided to guide an operation of a shutter unit280and also to open and close an optical window1036. In an embodiment, one pair of pressing units220may be provided to guide both sides of the shutter unit280, such that the shutter unit280is operated. However, the disclosure is not limited thereto, and at least one pressing unit220may be provided so as to guide the operation of the shutter unit280.

The shutter guide member248may be provided to protrude from one side surface of the pressing body242of the pressing part240. That is, the shutter guide member248may be provided to have a protrusion shape which extends from the pressing body242.

Specifically, the shutter guide member248may be formed to protrude from the pressing body242, and may be formed to protrude perpendicular to a forward and backward moving direction of the pressing part240. Due to such a structure, the shutter guide member248may guide the shutter unit280and a forward and backward movement of the pressing part240.

The shutter unit280is provided to open and close the optical window1036. Light generated from the optical scanning unit is radiated through the optical window1036, and the radiated light passes through the optical window1036and is radiated onto the photoreceptor1052. The shutter unit280is provided to open and close the optical window1036, such that the light is selectively radiated onto the photoreceptor1052.

The shutter unit280may include a shutter body282and a shutter rotating part284provided at the shutter body282.

The shutter body282may be provided to correspond to the optical window1036. The shutter body282may be formed in a lengthwise direction of the optical window1036or the photoreceptor1052so as to correspond to the optical window1036and the photoreceptor1052. The shutter body282may be provided to be moved between an opening position S1in which the optical window1036is opened and a closing position S2in which the optical window1036is closed. The shutter body282may be rotated about the shutter rotating part284and thus may be moved between the opening position S1and the closing position S2.

A shutter protrusion283which corresponds to the shutter guide member248of the pressing part240may be provided at the shutter body282. The shutter protrusion283may be formed to protrude from the shutter body282, and may be provided at an end of the shutter body282. In an embodiment of the disclosure, since one pair of pressing units220is provided at both ends of the shutter unit280, one pair of shutter protrusions220may be provided at both ends of the shutter body282.

Due to such a structure, while the pressing unit220is moved from the releasing position P2to the pressing position P1, the shutter guide member248of the pressing part240presses the shutter protrusion283of the shutter unit280. Therefore, when the pressing unit220is at the pressing position P1, the developing unit1041is pressed, and at the same time, the shutter unit280is at the opening position S1.

A movement of the shutter unit280from the closing position S2to the opening position S1may be performed so that the shutter protrusion283is pressed by the shutter guide member248, and a movement of the shutter unit280from the opening position S1to the closing position S2may be performed so that the shutter falls down due to its own weight. Of course, the movement of the shutter unit280from the opening position S1to the closing position S2may be interlocked with a movement of the pressing unit220from the pressing position P1to the releasing position P2. However, in the embodiment, for example, the shutter unit280is provided to be operated by its own weight.

The shutter body282may be rotated about the shutter rotating part284, and is provided so that an angle between the shutter body282when the shutter unit280is at the closing position S2and the shutter body282when the shutter unit280is at the opening position S1forms an acute angle. That is, a rotating angle of the shutter unit280between the opening position S1and the closing position S2forms the acute angle.

At the closing position S2, the shutter body282may be provided in parallel with the optical window1036, and at the opening position S1, the shutter body282forms the acute angle with respect to the optical window1036.

Due to such a structure, when the shutter unit280is moved from the opening position S1to the closing position S2, the shutter body282may be moved by its own weight.

FIG. 15is a perspective view illustrating an arrangement of the operating unit in accordance with an embodiment of the disclosure,FIG. 16is a side view illustrating a pressing state of the operating unit in accordance with an embodiment of the disclosure,FIG. 17is an exploded perspective view of the operating unit in the pressing assembly in accordance with an embodiment of the disclosure, andFIG. 18is a cross-sectional perspective view illustrating the operating unit in accordance with an embodiment of the disclosure.

The operating unit250may be provided to be rotatable, such that the pressing unit220is operated by the operation of the operating unit250. That is, the at least one pressing unit220is provided to be interlocked with the operating unit250.

The operating unit250may include an operating body252which is connected with the rotating shaft210so as to be rotated about the rotating shaft210.

The operating unit250is provided to be movable between an operating position01in which a pressing force is generated from the pressing unit220and a stand-by position02in which the pressing force is released.

When the operating unit250is located at the operating position01, the pressing unit220presses the developing unit1041, and when the operating unit250is located at the stand-by position02, the pressing of the pressing unit220with respect to the developing unit1041is released.

The operating unit250may include the operating body252and a pressing member260.

The operating body252may be provided to be rotated about the rotating shaft210.

The pressing member260may be provided at the operating body252so as to press the developing device1040in a direction in which the developing device1040is installed at the developing device seating part1005. The first direction W1may include an installing direction W1ain which the developing device1040is installed at the developing device seating part1005, and a separating direction W1bwhich is opposite to the installing direction W1aand in which the developing device1040is separated from the developing device seating part1005. The pressing member260may be provided to press the developing device1040in the installing direction W1a. Specifically, the pressing member260may be provided to press the photoreceptor unit1050of the developing device1040.

The operating unit250may include a rotating part254. The rotating part254may be provided at the operating body252to be rotatably supported by the rotating shaft210. The rotating part254has a hollow portion through which the rotating shaft210passes, and the operating body252extends from the rotating part254in a direction perpendicular to a rotating axis. One end of the rotating part254may be formed to be supported by the developing device seating part1005.

An operation elastic part264may be provided at the rotating part254, and the operating unit250may be provided to press the developing device1040in the installing direction W1a. The operation elastic part264will be described below in detail.

The pressing member260may include a pressing surface262which is formed toward the developing device1040so as to come into contact with the developing device1040. The pressing surface262may be provided to come into direct contact with the developing device1040. The pressing surface262may be provided to press the developing device1040, while the operating unit250is moved from the stand-by position02to the operating position01.

The pressing surface262may include a first pressing part262aand a second pressing part262b. The first pressing part262amay be disposed in front of the second pressing part262bin a direction in which the operating unit250is rotated from the stand-by position02to the operating position01.

The first pressing part262amay be provided to be more concave in the separating direction W1bthan the second pressing part262b.

Contrarily, the second pressing part262bmay be provided to be more convex in the installing direction W1athan the first pressing part262a.

When the operating unit250is moved from the stand-by position02to the operating position01, the developing device1040first comes into contact with the first pressing part262a, and then into contact with the second pressing part262b. That is, the second pressing part262bwhich extends from the first pressing part262ais formed to be more spaced apart in the installing direction W1athan the first pressing part262a, and thus the second pressing part262bcomes into contact with the developing device1040after the operating unit250is moved to the operating position01.

At least a part of the pressing surface262may be provided to form a curved surface. Thus, the second pressing part262bmay extend from the first pressing part262ain the form of the curved surface. Due to such a structure, when the operating unit250is moved from the stand-by position02to the operating position01, the developing device1040may be pressed smoothly.

A to-be-pressed surface1056is provided at the developing device1040to correspond to the pressing surface262. The to-be-pressed surface1056is provided to be pressed by the pressing surface262of the operating unit250. Specifically, the to-be-pressed surface1056may be provided at the photoreceptor unit1050of the developing device1040.

The to-be-pressed surface1056may be inclined so as to correspond to the pressing surface262. That is, the to-be-pressed surface1056may include a first to-be-pressed part1056awith which the first pressing part262acomes into contact, and a second to-be-pressed part1056bwith which the second pressing part262bcomes into contact and which is formed to extend from the first to-be-pressed part1056aand to have a slope inclined in the separating direction W1b.

The operating unit250may include the operation elastic part264.

The operation elastic part264may be provided at the rotating part254to provide the elastic force to the operating unit250. That is, the operation elastic part264may be provided so as to provide the elastic force to the operating unit250in the installing direction W1a, such that the operating unit250presses the developing device1040in the installing direction W1a. The rotating part254may be formed in a cylindrical shape with a hollow internal space. An installing space256may be formed at an inner side of the rotating part254so that the operation elastic part264is located therein. The installing space256may include a first installing space256ain which an installation elastic member265to be described below is installed, and a second installing space256bin which a fastening member266is installed.

The operation elastic part264may include the installation elastic member265and the fastening member266.

The fastening member266may be provided at the rotating shaft210to support one end of the installation elastic member265. That is, since the movement of the rotating shaft210in the first direction W1is restricted, and the fastening member266is disposed perpendicular to the axial direction, the installation elastic member265may be provided not to be separated from the fastening member266. A shape of the fastening member266provided at the rotating shaft210is not limited specifically. In an embodiment of the disclosure, the fastening member266is formed in a pin shape, and provided to pass through the rotating shaft210perpendicular to the axial direction of the rotating shaft210.

The operating unit250may include a movement restricting surface257which is provided to come into contact with the fastening member266and thus to restrict the movement of the operating unit250in the separating direction W1b. The second installing space256bmay be formed in the rotating part254using the movement restricting surface257as a boundary line. When the operating unit250is moved in the separating direction W1b, the fastening member266comes into contact with the movement restricting surface257of the operating unit250, and thus the movement of the operating unit250in the separating direction W1bis restricted.

Since the fastening member266supports one end of the installation elastic member265, a diameter of the second installing space256bin which the fastening member266is installed is greater than that of the first installing space256ain which the installation elastic member265is installed, and thus the movement restricting surface257may be formed from a circumference of the first installing space256ato a circumference of the second installing space256b.

The installation elastic member265may be disposed in the installing space256. One end of the installation elastic member265may be supported by the fastening member266, and the other end thereof is supported by an axial inner side surface of the rotating part254. The installation elastic member265is provided to surround an outer circumferential surface of the rotating shaft210, such that the elastic force generated from the installation elastic member265is axially transmitted to the operating unit250. Specifically, the installation elastic member265generates the elastic force so as to press the operating unit250in the installing direction W1a.

Hereinafter, an operation of the image forming apparatus in accordance with an embodiment of the disclosure will be described.

After the developing device1040is seated on the developing device seating part1005, the developing unit1041and the photoreceptor unit1050should come into close contact with each other so that the developing roller1042and the photoreceptor1052come into contact with each other, and thus the printing operation may be performed.

The pressing assembly200is operated so that the developing unit1041and the photoreceptor unit1050come into close contact with each other.

In the initial stage, the operating unit250may be located at the stand-by position02, and when the developing device1040is seated on the developing device seating part1005, the operating unit250is rotated so that pressing unit220presses the developing unit1041.

When the operating unit250is rotated from the stand-by position02to the operating position01, the link unit230of the pressing unit220is operated so that the pressing part240presses the developing unit1041. The pressed developing unit1041comes into close contact with the photoreceptor unit1050, and the developing roller1042and the photoreceptor1052come into contact with each other.

While the operating unit250is rotated from the stand-by position02to the operating position01, the pressing unit220is moved from the releasing position P2to the pressing position P1. While the pressing unit220is moved from the releasing position P2to the pressing position P1, the pressing part240presses the developing unit1041and also opens the shutter unit280at the same time.

Specifically, the pressing surface242aof the pressing part240presses the developing unit1041, and the shutter guide member248of the pressing part240guides the rotation of the shutter unit280. The shutter guide member248presses the shutter protrusion283of the shutter unit280, and the shutter unit280is rotated about the shutter rotating part284and moved from the closing position S2to the opening position S1.

When the operating unit250is rotated from the stand-by position02to the operating position01, the developing device1040is in a state capable of forming an image, and at the same time, the light generated from the optical scanning unit is radiated onto the photoreceptor1052.

When the operating unit250is at the operating position01, the pressing unit220presses the developing unit1041, and the operating unit250presses the photoreceptor unit1050of the developing device1040in the installing direction W1a. The pressing member260of the operating unit250presses the developing device1040in the installing direction W1a.

When the operating unit250is rotated from the stand-by position02to the operating position01, the first pressing part262aof the pressing member260first comes into contact with the first to-be-pressed part1056aof the to-be-pressed surface1056of the developing device1040. When the operating unit250is rotated to the operating position01, the second pressing part262bof the pressing member260comes into contact with the second to-be-pressed part1056bof the to-be-pressed surface1056of the developing device1040.

In this process, the operating unit250presses the photoreceptor unit1050of the developing device1040in the installing direction W1aby the elastic force generated by the operation elastic part264.

When the operating unit250is rotated from the pressing position P1to the stand-by position02, a reverse process is performed.

Hereinafter, an image forming apparatus in accordance with an embodiment of the disclosure will be described.

Repeated description of the same structure as that described previously will be omitted.

FIG. 19is a view illustrating an arrangement of a developing device and a cover unit of the image forming apparatus in accordance with an embodiment of the disclosure,FIG. 20is a front view illustrating a pressing unit in accordance with an embodiment of the disclosure, andFIG. 21is a perspective view illustrating the pressing unit and a shutter unit in accordance with an embodiment of the disclosure.

The developing device1040may be provided to be seated on the developing device seating part1005. The waste toner storing unit in which the waste toner generated from the developing device1040is stored may be provided at one side of the developing device1040. The toner used in the developing device1040may be moved to the waste toner storing unit and stored therein. In an embodiment of the disclosure, the waste toner storing unit may be referred to as a cover unit370.

A shutter unit380may be provided to open and close the optical window1036. Light generated from the optical scanning unit is radiated through the optical window1036, and the radiated light passes through the optical window1036and is radiated onto the photoreceptor1052. The shutter unit380may be provided to open and close the optical window1036, such that the light is selectively radiated onto the photoreceptor1052.

The shutter unit380may include a shutter body382, and a shutter to-be-pressed part386which is provided at the shutter body382.

The shutter body382may be provided to correspond to the optical window1036. The shutter body382may be elongated in a lengthwise direction of the optical window1036or a lengthwise direction of the photoreceptor1052so as to correspond to the optical window1036and the photoreceptor1052. The shutter body382may be provided to be moved between the opening position S1in which the optical window is opened, and the closing position S2in which the optical window is closed. In an embodiment of the disclosure, since the image forming apparatus having a plurality of developing devices1040is applied, the shutter body382is also provided to correspond to the plurality of developing devices1040. However, the image forming apparatus having a single developing device1040, instead of the plurality of developing devices1040, may also be applied.

The shutter body382may include a shutter hole382acorresponding to the optical window1036. The shutter hole382ais elongated so as to correspond to the optical window1036, and provided so that the light radiated to the optical window1036may pass through the photoreceptor1052.

When the shutter unit380is at the opening position S1, the light radiated to the optical window1036may pass through the shutter hole382a, and when the shutter unit380is at the closing position S2, the light radiated to the optical window1036may be blocked by the shutter body382.

The light which is selectively radiated to the optical window1036through the movement of the shutter unit380between the opening position S1and the closing position S2may be transmitted to the photoreceptor1052.

Assuming that the lengthwise direction of the optical window1036or the lengthwise direction of the photoreceptor unit1050is a first direction W1, the shutter unit380is provided to reciprocate in a second direction W2vertical to the first direction W1.

The shutter unit380may include a returning elastic member387. The returning elastic member387may be provided at one side of the shutter body382so that the shutter unit380is returned from the opening position S1to the closing position S2. One end of the returning elastic member387is supported by the shutter body382, and the other end thereof is supported by the developing device seating part1005. Due to such a structure, when the pressing of the pressing unit320is released, the shutter unit380may be elastically returned from the opening position S1to the closing position S2. An arrangement of the returning elastic member387is not limited. However, in the embodiment of the disclosure, the returning elastic member387is disposed on a moving route of the shutter unit380. Specifically, the returning elastic member387is disposed at a rear side of a moving route of the shutter body382so that the shutter body382is elastically returned.

The pressing unit320is provided to be interlocked with the shutter unit380. The pressing unit320is provided to be moved between a pressing position P1in which the shutter unit380is pressed, and a releasing position P2in which the pressing applied to the shutter unit380is released.

The pressing unit320may include a pressing body342and a pressing elastic member348which provides an elastic force to the pressing body342.

The pressing body342may be provided to reciprocate by an external force. The pressing body342may be formed to be elongated in the first direction W1. One end of the pressing body342receives the external force in the first direction W1, and the other end thereof transmits the external force to the shutter unit380.

The pressing body342may be formed to be elongated in the first direction W1and to reciprocate in the first direction W1. Specifically, the pressing body342may be moved in an installing direction W1aof the first direction W1by the external force, and returned in a separating direction W1bwhen the external force is released. That is, the pressing body342is moved from the releasing position P2to the pressing position P1by the external force, and returned from the pressing position P1to the releasing position P2when the external force is released.

The pressing elastic member348may be provided so that the pressing unit320moved in the installing direction W1ais returned in the separating direction W1b. The pressing body342may include an elastic catching protrusion344which protrudes from the pressing body342so that one end of the pressing elastic member348is supported thereby. One end of the pressing elastic member348may be supported by the elastic catching protrusion344which protrudes from the pressing body342, and the other end thereof may be supported by the main body. When the external force is applied to the pressing body342, and thus the pressing body342is moved in the installing direction W1a, the pressing elastic member348generates the elastic force by which the pressing body342is moved in the separating direction W1b, and when the external force is released, the pressing body342is returned to its original position by the elastic force.

The other end of the pressing body342is provided so as to press the shutter unit380. Specifically, the pressing body342may include a pressing part346which presses the shutter unit380. The pressing part346presses the shutter to-be-pressed part386of the shutter unit380. Since the pressing unit320reciprocates in the first direction W1, and the shutter unit380reciprocates in the second direction W2perpendicular to the first direction W1, the shutter to-be-pressed part386of the shutter unit380has an inclined surface which is inclined in the first and second directions W1and W2.

That is, the shutter to-be-pressed part386may include a pressing inclined surface386ahaving a component of the first direction W1and a component of the second direction W2so that the shutter unit380is operated in the second direction W2perpendicular to the first direction W1. The pressing part346of the pressing body342comes into contact with the pressing inclined surface386aand then presses the pressing inclined surface386a, and thus the shutter unit380may be moved in the second direction W2.

The cover unit370may be detachably provided at one side of the developing device1040. The cover unit370may be provided so that the operation of the pressing unit320is interlocked with an attachment and detachment of the cover unit370. Specifically, the cover unit370moves the pressing unit from the releasing position P2to the pressing position P1, while installed at one side of the developing device1040. Contrarily, when the cover unit370is separated from the one side of the developing device1040, the pressing unit320is moved from the pressing position P1to the releasing position P2.

Hereinafter, an operation of the image forming apparatus in accordance with an embodiment of the disclosure will be described.

FIGS. 22A and 22Bare views illustrating an interlocking operation of the pressing unit, the shutter unit and the cover unit in accordance with an embodiment of the disclosure.

First, an operation in which the shutter unit380is opened will be described.

When the pressing unit320is moved from the releasing position P2to the pressing position P1, the pressing part346of the pressing unit320presses the shutter unit380, and moves the shutter unit380from the closing position S2to the opening position S1.

Specifically, while the pressing unit320is moved from the releasing position P2to the pressing position P1, the pressing part346is moved in the first direction W1so as to press the shutter to-be-pressed part386of the shutter unit380. The pressing inclined surface386aof the shutter to-be-pressed part386converts the movement of the pressing part346in the first direction W1into the movement of the shutter unit380in the second direction W2.

While the shutter unit380is moved from the closing position S2to the opening position S1, the light radiated to the optical window1036is transmitted to the photoreceptor1052, and thus the electrostatic latent image may be formed.

The pressing unit320may be directly moved from the releasing position P2to the pressing position P1, or the pressing unit320may be operated by the cover unit370, similar to the embodiment of the disclosure.

When the cover unit370is installed at one side of the developing device1040, the cover body of the cover unit370presses the pressing unit320so that the pressing unit320is moved from the releasing position P2to the pressing position P1. Through such a structure, the cover unit370is installed at the developing device1040so that the developing device1040is in an available state, and also the optical window1036is opened so that the light may be radiated.

Then, an operation in which the shutter unit380is closed will be described.

When the pressing unit320is moved from the pressing position P1to the releasing position P2, the pressing of the pressing part346of the pressing unit320with respect to the shutter unit380is released. When the pressing of the pressing unit320is released, the returning elastic member387of the shutter unit380returns the shutter unit380from the opening position S1to the closing position S2.

In the case in which the pressing unit320is directly moved from the releasing position P2to the pressing position P1, when the pressing with respect to the pressing unit320is released, the pressing unit320is moved from the pressing position P1to the releasing position P2by the elastic force of the pressing elastic member348.

Similar to an embodiment of the disclosure, in the case in which the pressing unit320is pressed by the cover unit370, when the cover unit370is separated from the developing device1040, the restriction on the pressing unit320by the cover unit370is released, and the pressing unit320is moved from the pressing position P1to the releasing position P2by the elastic force of the pressing elastic member348.

Hereinafter, an image forming apparatus in accordance with an embodiment of the disclosure will be described.

FIG. 23is a view illustrating a developing device and a cover unit in accordance with an embodiment of the disclosure,FIGS. 24A and 24Bare views illustrating an operation of a pressing assembly and the developing device in accordance with an embodiment of the disclosure,FIGS. 25A and 25Bare cross-sectional views illustrating a pressing unit depending on the operation of the pressing assembly in accordance with an embodiment of the disclosure, andFIG. 26is an exploded perspective view of the pressing assembly in accordance with an embodiment of the disclosure.

A pressing assembly100may be disposed adjacent to the developing device1040, such that the developing unit1041and the photoreceptor unit1050come into contact with or are separated from each other. Specifically, the pressing assembly100is provided so that the developing roller1042of the developing unit1041and the photoreceptor1052of the photoreceptor unit1050come into contact with or are separated from each other. An arrangement of the pressing assembly100is not limited. However, in an embodiment, the pressing assembly100is disposed at the developing device seating part1005.

The pressing assembly400may include a rotating shaft410, a pressing unit420, and an operating unit450.

The rotating shaft410may be rotatably provided so that an operation of the operating unit450is transmitted to the pressing unit420. Assuming that a lengthwise direction of the developing device1040, the developing unit1041and the photoreceptor unit1050is a first direction W1, the rotating shaft410may be formed to be elongated in the first direction W1. The first direction W1may be defined as a direction vertical to a moving direction of the print medium. The rotating shaft410may serve as a rotating center of the operating unit450, which will be described below.

The rotating shaft410may be disposed in the first direction W1and may be provided so that a movement thereof in the first direction W1is restricted. The rotating shaft410may be provided to be rotated about a rotating axis. At least one shaft stopper may be provided at an outer circumferential surface of the rotating shaft410(in a manner similar to shaft stopper211) so that a movement of the rotating shaft410in the first direction W1is restricted.

The pressing unit420is provided so that the developing roller1042and the photoreceptor1052come into close contact with each other. Specifically, the pressing unit420is provided to press the developing unit1041, such that the developing roller1042and the photoreceptor1052come into contact with or in close contact with each other. The pressing unit420may be disposed on the rotating shaft410, and may be provided so as to receive an operation of the operating unit450through the rotating shaft410and thus to be operated thereby.

The pressing unit420may be provided to be interlocked with the operating unit450. At least one pressing unit420may be provided. Through such a structure, at least one pressing unit420is provided to be interlocked with operating unit450and thus to be operated. In the case in which a plurality of pressing units420are provided, the plurality of pressing units420may be disposed on the rotating shaft410to be spaced from each other. As an example, the plurality of pressing units420may be disposed on the rotating shaft410to be spaced at regular intervals from each other, such that the same pressing force is distributed in the first direction W1, and thus the developing unit1041is pressed by an uniform pressing force, regardless of a position in a lengthwise direction thereof.

The pressing unit420may be provided to be moved between a pressing position P1in which the developing roller1042and the photoreceptor1052come into contact with each other, and a releasing position P2which is moved backed from the pressing position P1so that the developing roller1042and the photoreceptor1052are separated from each other. Specifically, when the pressing unit420is at the pressing position P1, the developing unit1041is pressed by the pressing unit420, and thus the developing roller1042and the photoreceptor1052come into contact with each other. Also, when the pressing unit420is at the releasing position P2, the pressing of the pressing unit420with respect to the developing unit1041is released, and thus the developing roller1042and the photoreceptor1052are separated from each other.

The operating unit450may be rotatably provided so that the pressing unit420is operated by the operation of the operating unit450. That is, at least one pressing unit420may be provided to be interlocked with the operating unit450.

The operating unit450may include an operating body453which is connected with the rotating shaft410so as to be rotated about the rotating shaft410.

The operating unit450may be provided to be movable between an operating position01in which a pressing force is generated from the pressing unit420and a stand-by position02in which the pressing force is released.

When the operating unit450is at the operating position01, the pressing unit420presses the developing unit1041, and when the operating unit450is at the stand-by position02, the pressing of the pressing unit420with respect to the developing unit1041is released.

The pressing unit420may include a pressing part440and a direction control part430.

The pressing part440may be provided to generate a pressing force, and the direction control part430may be provided to change a direction of the pressing force of the pressing part440.

The pressing part440may include a pressing body442and a pressing elastic member446.

The pressing body442may be provided to press the developing unit1041. The pressing body442may be disposed perpendicular to a lengthwise direction of the rotating shaft410. A pressing surface442ais provided at a front portion of the pressing body442. The pressing surface442amay be provided to come into direct contact with the developing unit1041and thus to press the developing unit1041.

The pressing body442may be provided so that the rotating shaft410passes through one side thereof. Specifically, the pressing body442has a through-hole442bthrough which the rotating shaft410passes, and is provided to be rotated separately from the rotating shaft410.

The pressing elastic member446is provided to provide an elastic force to the pressing body442and thus to press the developing unit1041. One end of the pressing elastic member446supports an inner side surface of the pressing body442, and the other end thereof supports the rotating shaft410in a direction perpendicular to the lengthwise direction of the rotating shaft410.

Both side surfaces of the pressing body442are opened, and the pressing body442is provided to be moved in the direction perpendicular to the lengthwise direction of the rotating shaft410. Specifically, a pressing space443in which the pressing elastic member446is disposed and an available space444which is varied according to an extension and compression of the pressing elastic member446are formed at an inner side of the pressing body442. That is, when the pressing elastic member446is compressed, the pressing space443is reduced, and the available space444is increased, and when the pressing elastic member446is restored, the pressing space443is increased, and the available space444is reduced.

The direction control part430is provided to control a direction of the pressing part440depending on a rotation of the rotating shaft410.

The direction control part430is formed to extend perpendicular to an axial direction from the rotating shaft410and also to be rotated along with the rotation of the rotating shaft410. The direction control part430may be integrally formed with the rotating shaft410, or may be formed to be vertically inserted into the rotating shaft410.

The direction control part430may include a direction guide part448guiding a direction of the pressing part440.

The direction guide part448serves as a medium between the pressing body442and the direction control part430. A change of a position of the direction control part430is transmitted to the pressing body442so as to change the direction of the pressing force of the pressing body442.

The direction guide part448is provided to cover at least a part of the pressing body442. The direction guide part448may include a direction guide surface448aof which a direction is guided by the direction control part430. One pair of direction guide surfaces448amay be provided in a circumferential direction of the rotating shaft410with respect to the direction control part430. An insertion space448bin which the direction control part430is inserted is formed between the one pair of direction guide surfaces448a. Through such a structure, when the direction control part430is rotated by the rotation of the rotating shaft410, one of the pair of direction guide surfaces448ais guided, and the pressing part440may be rotated also.

The operating unit450may include a rotating body451, and an operating member452which operates the rotating body451.

The rotating body451is provided to be rotated along with the rotating shaft410, and the operating member452is provided to be rotatable with respect to the rotating shaft410and thus to rotate the rotating body451.

The rotating body451may be provided at an end of the rotating shaft410to be rotated along with the rotating shaft410. The rotating body451may be provided to protrude perpendicular to the axial direction of the rotating shaft410. A fastening member451amay be provided at the rotating body451so that the rotating body451and the rotating shaft410are rotated together.

The operating member452may be provided to rotate the rotating body451.

The operating member452may include the operating body453, a unit pressing part454, and a rotation guide part456.

The operating body453is disposed perpendicular to the rotating shaft410and adjacent to the rotating body451. The operating body453may be integrally formed with the rotating shaft410to be rotated along with the rotation of the rotating shaft410. However, in an embodiment, the operating body453may be provided to guide the rotation of the rotating body451, such that the rotating shaft410integrally formed with the rotating body451is also rotated together. That is, the operating body453may be rotated separately from the rotating shaft410, and may have a hole through which the rotating shaft410passes.

In regard to a cover unit470which will be described below, the operating body453may be provided so that whether or not the cover unit470may be installed is determined according to a pressed state of the developing unit1041.

The unit pressing part454may be provided on the operating body453so as to press the photoreceptor unit1050. Specifically, the unit pressing part454may be disposed at an end of the operating body453, and when the operating unit450is at the operating position01, the unit pressing part454presses the photoreceptor unit1050. The unit pressing part454may be is formed to protrude more than the adjacent operating body453, and a unit to-be-pressed part1058which is formed to be concave corresponding to the pressing part440is disposed at the photoreceptor unit1050. By seating the unit pressing part454on the unit to-be-pressed part1058, the photoreceptor unit1050is prevented from being separated in the separating direction W1b.

The rotation guide part456may be disposed at the operating body453in a direction of the rotating center thereof so as to guide the rotation of the rotating body451. The rotation guide part456and the rotating body451are spaced apart a predetermined distance, and when the operating body453is rotated at a predetermined angle, the rotation guide part456and the rotating body451come into contact with each other, and thus the rotating force is transmitted. Therefore, an actual rotating angle of the rotating body451is greater than a rotating angle of the operating body453. As the rotating angle of the operating body453is increased, a risk of malfunction in a structure which is interlocked with whether or not the cover unit470may be installed is reduced. The distance between the rotation guide part456and the rotating body451is not limited, and may be varied according to various factors such as a size of the image forming apparatus and an arrangement of the developing device1040.

The rotation guide part456may include an operating rotation guide part456aand a stand-by rotation guide part456b.

When the operating unit450is moved from the stand-by position02to the operating position01, the operating rotation guide part456apresses the rotating body451, and thus the pressing unit420is moved to the pressing position P1. Contrarily, when the operating unit450is moved from the operating position01to the stand-by position02, the stand-by rotation guide part456bpresses reversely the rotating body451, and thus the pressing unit420is moved to the releasing position P2. One pair of the operating rotation guide part456aand the stand-by rotation guide part456bmay be provided within a rotational radius of the rotating body451on the operating body453.

The cover unit470may be detachably provided at one side of the developing device1040. Whether or not the cover unit470may be installed may be determined according to a position of the operating unit450. Specifically, the cover unit470may be installed only when the operating unit450is at the operating position01.

The cover unit470may include a cover body472and an operating insertion part474.

The cover body472may be provided to cover one side of the developing device1040, and may be provided to be connected with the developing device1040and thus to store waste toner generated from the developing device1040.

The operating insertion part474may be formed to be concave from the cover body372so that the operating body453of the operating unit450is inserted therein. The operating body453may be inserted into the operating insertion part474, only when the operating unit450is at the operating position01. That is, only when the operating unit450is at the operating position01, and the pressing unit420is at the pressing position P1, the operating body453may be inserted into the operating insertion part474. The operating insertion part474is provided to correspond to the operating body453, such that the operating body453is inserted therein, only when the operating unit450is at the operating position01.

The operating insertion part474may be more concave than the adjacent cover body472. When the operating unit450is at another position other than the operating position01, the cover body372interferes with the operating body453, and the cover unit470may not be installed at the developing device1040.

Hereinafter, an operation of the image forming apparatus in accordance with an embodiment of the disclosure will be described.

FIGS. 27A and 27Bare views illustrating the developing device of the cover unit depending on the operation of the pressing assembly in accordance with an embodiment of the disclosure.

To perform a printing operation after the developing device1040is seated on the developing device seating part1005, the developing unit1041and the photoreceptor unit1050should come into close contact with each other so that the developing roller1042and the photoreceptor1053come into contact with each other.

The pressing assembly400is operated so that the developing unit1041and the photoreceptor unit1050should come into close contact with each other.

In the initial stage, the operating unit450is at the stand-by position02, and when the developing device1040is seated on the developing device seating part1005, the operating unit450is rotated so that the pressing unit420presses the developing unit1041.

The operating body453is rotated so as to rotate the operating unit450from the stand-by position02to the operating position01. Due to the rotation of the operating body453, the operating rotation guide part456aof the rotation guide part456of the operating body453presses the rotating body451, and thus the rotating body451and the rotating shaft410are rotated. The rotating shaft410is rotated along with the direction control part430of the pressing unit420. Through such an operation, the direction of the pressing force generated from the pressing part440is controlled, and the developing unit1041is pressed. That is, the pressing unit420is moved to the pressing position P1.

When the operating unit450is at the operating position01, the unit pressing part454of the operating body453is seated on the unit to-be-pressed part1058of the photoreceptor unit1050to prevent the photoreceptor unit1050from being separated. When the operating unit450is at the operating position01, the operating body453may be inserted into the operating insertion part474of the cover unit470, and thus the cover unit470may be installed at the developing device1040.

To rotate the operating unit450from the operating position01to the stand-by position02, the operating body453is rotated reversely. Due to the rotation of the operating body453, the stand-by rotation guide part456bof the rotation guide part456of the operating body453presses reversely the rotating body451, and thus the rotating body451and the rotating shaft410are rotated. The rotating shaft410is rotated along with the direction control part430of the pressing unit420. Through such an operation, the direction of the pressing force generated from the pressing part440is controlled, and the pressing to the developing unit1041is released. That is, the pressing unit420is moved to the releasing position P2.

When the operating unit is at the stand-by position02, the unit pressing part454of the operating body453is separated from the to-be-pressed surface1056of the photoreceptor unit1050, and the developing device1040is in a state to be separable from the developing device seating part1005. When the operating unit is at the stand-by position02, the cover body472interferes with the operating body453, and thus the cover unit470may not be installed at the developing device1040. Therefore, the image forming apparatus is operated, even though the developing roller1042and the photoreceptor1052are separated, and thus the malfunction or damage of the image forming apparatus may be prevented. That is, whether the image forming apparatus may be operated may be determined by whether or not the cover unit470may be installed, and thus the malfunction or the damage may be prevented beforehand.

According to the image forming apparatus of the disclosure, the fixing structure of the developing unit is improved, and thus the developing unit may be effectively installed in the main body.

Also, the pressing structure of the developing unit is improved, and thus a defective image may be prevented from being formed even when the external impact is applied.

Also, each embodiment may be applied complementarily. For example, the operating unit of the image forming apparatus in accordance with any embodiment of the disclosure may be applied to that in accordance with any other embodiment of the disclosure, and the shutter unit of the image forming apparatus in accordance with any embodiment of the disclosure may be applied to that in accordance with any other embodiment of the disclosure.