Image forming apparatus

An image forming apparatus includes a cartridge which ejects an ink, a chamber having an inlet unit which inhales a fog generated when the ink is ejected from the cartridge and an outlet unit which exhales the inhaled fog, an air pressure generating unit which is connected to the chamber to generate an air pressure to inhale and exhale the fog from the chamber, and a valve unit which selectively opens and closes the inlet unit and the outlet unit by the air pressure which is generated in the air pressure generating unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(a) from Korean Patent Application No. 2006-0131754, filed on Dec. 21, 2006 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present general inventive concept relates to an image forming apparatus, and more particularly, to an image forming apparatus having a configuration to remove a fog generated when ink is ejected from a cartridge.

2. Description of the Related Art

An image forming apparatus of an ink-jet type forms an image by ejecting ink from a cartridge onto a recording material.

The image forming apparatus provides a nozzle unit to eject the ink on a bottom surface of the cartridge. Accordingly, as the ink is repetitively ejected, the nozzle unit clogs with bubbles, foreign substances, or the like so that the ink cannot be smoothly ejected. Accordingly, a spitting process for ejecting a predetermined amount of ink through the nozzle unit is performed to prevent a channel of the nozzle unit from clogging, as one example of a maintenance process performed during a period in which the image forming apparatus is not forming an image.

A conventional image forming apparatus has a spitting unit below the nozzle unit, which collects the ejected ink from the nozzle unit during the spitting process. However, during the spitting process, a lot of fine ink fogs above the spitting unit.

Since the conventional image forming apparatus does not collect the fog, many malfunctions may be caused by the fog generated at the spitting process and attached to the nozzle unit, the cartridge, and the like. The fog pollutes an inner part of the image forming apparatus and lowers an image quality of the image formed on the recording materials.

Thus, it may be desired to collect and remove the fog generated at the spitting process.

SUMMARY OF THE INVENTION

The present general inventive concept provides an image forming apparatus to collect and remove an ink fog.

The foregoing and/or other aspects and utilities of the present general inventive concept can be achieved by providing an image forming apparatus comprising a cartridge which ejects an ink, a chamber having an inlet unit which inhales a fog which is generated when the ink is ejected from the cartridge and an outlet unit which exhales the inhaled fog, an air pressure generating connected to the chamber to generate an air pressure to inhale and exhale the fog from the chamber, and a valve unit which selectively opens and closes the inlet unit and the outlet unit by the air pressure generated in the air pressure generating unit.

The air pressure generating unit may comprise a bellows unit which expands and compresses to change the inner pressure of the chamber, and a driving unit to expand and compress the bellows unit.

The air pressure generating unit may comprise a cylinder to communicate with the chamber, a piston to reciprocate in the cylinder to expand and compress the inner air of the cylinder, and a driving unit to reciprocate the piston.

The image forming apparatus may further comprise a fog receiving unit connected to the outlet unit to receive the fog which is exhaled from the chamber.

The chamber may comprise a first room formed with the inlet unit on a first side thereof to communicate with the air pressure generating unit on a second side thereof, a second room separated from the first room and formed with the outlet unit on one side thereof, and a chamber communicating unit to be formed so as to allow the first room to communicate with the second room.

The valve unit may comprise an inlet opening/closing member to open and close the inlet unit according to the pressure change of the first room, and an outlet opening/closing member to open and close the chamber communicating unit according to the pressure change of the first room.

The valve unit may comprise an inlet valve unit provided in the inlet unit and opened if the fog is inhaled to the chamber, and an outlet valve unit provided in the outlet unit and opened if the fog is exhaled from the chamber.

The valve unit may have a plate shape to be mounted to the chamber, and the inlet valve unit and the outlet valve unit may be formed on a plate surface of the valve unit.

The foregoing and/or other aspects and utilities of the present general inventive concept are also achieved by providing an image forming apparatus, comprising a cartridge to eject ink, a spitting unit to receive the ink ejected from the cartridge during a spitting process, and a fog removing unit to remove a fog generated during the spitting process, the fog removing unit comprising a chamber connected to the spitting unit to inhale the fog therefrom, a fog receiving unit to receive a fog exhaled from the chamber, and an air pressure generating unit to change an internal air pressure of the chamber to inhale the fog from the spitting unit and exhale the fog to the fog receiving unit.

The chamber may comprise an inlet unit to receive the fog from the spitting unit, an outlet unit to direct the fog to the fog receiving unit, and a valve unit to selectively open and close the inlet unit and the outlet unit by the air pressure changes generated by the air pressure generating unit.

The valve unit may comprise a flexible plate to allow one-way flow of the fog through only one of the inlet and outlet units according to the internal air pressure of the chamber.

The inlet unit may comprise a gravity valve to allow the fog into the chamber when the internal pressure thereof is decreased by the air pressure generating unit, and prevents the fog from flowing back to the spitting unit when the internal pressure of the chamber is increased by the air pressure generating unit.

The outlet unit may comprise a gravity valve to allow the fog in the chamber to flow to the fog receiving unit when the internal pressure of the chamber is increased by the air pressure generating unit, and prevents the fog from flowing back from the fog receiving unit when the internal pressure of the chamber is decreased by the air pressure generating unit.

The foregoing and/or other aspects and utilities of the present general inventive concept are also achieved by providing a fog absorption apparatus to absorb fog created from an ink spitting unit, the apparatus comprising a fog chamber including a first one way valve to inhale fog from an ink spitting process of the ink spitting unit and a second one way valve to exhale the inhaled for externally away from the ink spitting unit.

The fog absorption apparatus may further comprise an air pressure generation unit to generate a negative air pressure in the fog chamber so that the fog chamber inhales the fog and to generate a positive air pressure so that the fog chamber exhales the inhaled fog.

The first one way valve may comprise an inlet pipe and a ball combination.

The second one way valve may comprise a first chamber room and a second chamber room and a chamber communicating unit.

The chamber communicating unit may comprise a passage between the first and second chamber rooms and a ball disposed at the passage to block airflow in one direction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As illustrated inFIG. 1toFIG. 3B, an image forming apparatus1according to an exemplary embodiment of the present general inventive concept may include a cartridge100to eject ink, a spitting unit200to provide a spitting region below the cartridge100, an air pressure generating unit300to generate air pressure to inhale and exhale a fog generated by the spitting unit200, a chamber400to inhale the fog and exhale the inhaled fog by the generated air pressure, a valve unit500to selectively open/close an inlet path and an outlet path of the fog, which is provided in the chamber400, and an exhaled-fog receiving unit600to exhale the fog inhaled to the chamber400.

The cartridge100stores ink therein and ejects the ink onto recording materials through a nozzle unit110provided on a bottom surface of the cartridge100so that an image of an image data can be formed. The cartridge100can be applicable to various known inkjet cartridge technologies, such as an array type cartridge, a shuttle type cartridge, or the like. In the case of the array type, the cartridge100can be fastened in the image forming apparatus1and the nozzle unit110can have a length to correspond to a width of the recording materials.

The nozzle unit110can be provided on the bottom surface of the cartridge100and can communicate with an inner part of the cartridge100so that the ink can be ejected from the nozzle unit110. As the nozzle unit110repetitively ejects the ink, a channel (not illustrated) which communicates with the inner part of the cartridge100may clog by various foreign substances so that the ink may not be smoothly ejected. A spitting process can be performed to solve this problem. For example, in the nozzle unit110, a positive pressure can be formed by a pressure adjusting apparatus (not illustrated) connected to the cartridge100so that the channel can be cleaned while a predetermined amount of ink is ejected.

The spitting unit200is provided below the cartridge100while facing the nozzle unit110. In the case of the array type cartridge100, the spitting unit200is lengthened along a lengthwise direction of the cartridge100to correspond to the nozzle unit110. The spitting unit200can be disposed in a position where it does not interfere with moving of the recording materials while an image is formed on the recording materials during a standby mode, and can move below the nozzle unit110by a predetermined driving apparatus (not illustrated) during the spitting process.

The spitting unit200may include a separate receiving unit (not illustrated) to receive the ink ejected from the nozzle unit110at the spitting process. At this time, the ink which is ejected and scattered from the spitting unit200forms a fog around the spitting unit200. The fog is inhaled into an inlet pipe210provided on one side of the spitting unit200or adjacent to the spitting unit200, and is directed to the chamber400.

One side of the air pressure generating unit300communicates with the chamber400. The air pressure generating unit300generates an air pressure so that the fog can be inhaled by the inlet pipe210and directed to the chamber400. Also, the air pressure generating unit300generates another air pressure so that the fog directed to the chamber400can be exhaled to the fog receiving unit600.

The air pressure generating unit300can communicate with one side of the chamber400so that the inner pressure of the chamber400can increase or decrease so as to have a predetermined pressure difference in comparison with an atmospheric air pressure. If the air pressure generating unit300makes the inner pressure of the chamber400decrease, the fog can be inhaled to the chamber400. On the other hand, if the air pressure generating unit300makes the inner pressure of the chamber400increase, the fog inhaled to the chamber400is exhaled. The air pressure generating unit300repeats the above process so that the fog can be repetitively inhaled to the chamber400and exhaled to the fog receiving unit600. The inner pressure difference of the chamber400generated by the air pressure generating unit300may be changed by a person skilled in the art in consideration of a plurality of design conditions.

The air pressure generating unit300may include a bellows unit310to be alternately expanded and compressed, a chamber connecting pipe320to connect the bellows unit310and the chamber400, and a driving unit330to repetitively expand and compress the bellows unit310.

The bellows unit310can be a plurality of creases which are repetitively formed along a lengthwise direction. A first side of the bellows unit310is supported by a bellows supporting unit311, and the creases of a second side of the bellows unit310are repetitively expanded and compressed by a driving unit330.

The bellows unit310can have airtight to prevent external air from being introduced thereinto. If the bellows unit310is expanded, the inner pressure of the chamber400decreases through the chamber connecting pipe320which passes through the bellows supporting unit311and is connected to the inner part of the bellows unit310. On the other hand, if the bellows unit310is compressed, the inner pressure of the chamber400increases.

The driving unit330may include a driving source331to generate a power, and a power transmission unit333to transmit the power from the driving source331to the bellows unit310so as to repeatedly expand and compress the bellows unit310.

The power transmission unit333can employ a gear, a connecting-rod, etc. which are interlocked for the power transmission and can transform a rotatory motion of the driving source331to a linear motion of the bellows unit310. In the exemplary embodiment of the present general inventive concept as illustrated inFIG. 2, the air pressure generating unit300itself has the driving unit331. However, the power transmission unit333can transfer the power from other driving apparatuses (not illustrated) of the image forming apparatus1without the driving source331.

The chamber400has a space therein, which is airtight from the outside. The chamber400is connected to the air pressure generating unit300so that the inner pressure of the chamber400can be changed by the air pressure generated in the air pressure generating unit300. By this, the fog is directed to the inner part of the chamber400through the inlet pipe210, or the fog directed to the chamber400is exhaled to the fog receiving unit600.

The inner part of the chamber400can be partitioned into a first room410and a second room420. The first room410and the second room420may communicate by a chamber communicating unit430.

On a first side of the first room410is provided an inlet unit411connected to the inlet pipe210, and a second side of the first room410is connected to a chamber connecting pipe320. Installation positions of the inlet unit411and the chamber connecting pipe320are not limited. However, the inlet unit411and the chamber connecting pipe320can be formed in a bottom surface of the first room410so that an inlet opening/closing member510(to be described later) can easily close the inlet unit411by gravity. Also, the chamber connecting pipe320can be connected to an upper side of the first room410so that the amount of the fog directed to the chamber connecting pipe320can be minimized when the fog is inhaled to the inner part of the chamber400.

While an inner configuration of the first room410is not limited by the present general inventive concept, a protrusion, an inclined plane, etc. which can guide the moving of the inlet opening/closing member510can be provided so that the inlet opening/closing member510(to be described later) can repetitively open/close the inlet unit411according to the pressure change of the first room410. However, within the scope to achieve the above purpose, it is possible that the inner configuration of the first room410may vary in design. The configuration which allows the chamber communicating unit430and the inlet opening/closing member510to be separated from each other should be formed so that the inlet opening/closing member510(to be described later) can not be used to open/close the chamber communicating unit430.

One side of the first room410communicates with the bellows unit310by the chamber connecting pipe320. The pressure of the first room410decreases if the bellows unit310is expanded. On the other hand, the pressure of the first room410increases if the bellows unit310is compressed.

On the one side of the second room420is formed an outlet unit421connected to an outlet pipe610(to be described later). The second room420is air tightly isolated from the first room410, and communicates with the first room410by the chamber connecting unit430. While the inner configuration of the second room420is not limited by the present general inventive concept, an outlet opening/closing member520(to be described later) does not close the outlet unit421so that the fog can be exhaled without difficulty.

According to the pressure change of the first room410, the chamber connecting unit430can be formed on the bottom surface of the second room420so that the outlet opening/closing member520can easily close the chamber connecting unit430by the gravity.

According to the pressure change of the first room410, the valve unit500selectively opens and closes the inlet unit411and the chamber connection unit430. The valve unit500includes the inlet opening/closing member510to open and close the inlet unit411, and the outlet opening/closing member520to open and close the chamber connecting unit430. The inlet opening/closing member510and the outlet opening/closing member520can be shaped like a ball having a larger diameter than those of the inlet unit411and the chamber communicating unit430, respectively, so as to close the inlet unit411and the chamber communicating unit430without regard to their falling direction when they fall down after they float by the pressure change of the first room410.

The inlet opening/closing member510placed in first room410opens/closes the inlet unit411. If the bellows unit310is expanded and the pressure of the first room410decreases, the inlet opening/closing member510floats at a predetermined height so that the fog inhaled to the inlet unit411can be directed to the first room410. At this time, the fog pushes up the inlet opening/closing member510from the inlet unit411, which helps the inlet opening/closing member510float. With this, a weight of the inlet opening/closing member510may be overcome by the change of the pressure of the first room410.

If the bellows unit310is compressed and the pressure of the first room410increases, the inlet opening/closing member510is downwardly pressurized toward the inlet unit411by the pressure and self-weight so as to close the inlet unit411.

The outlet opening/closing member520in the inner part of the second room420opens and closes the chamber communicating unit430. If the pressure of the first room410decreases by the bellows unit310, the pressure of the second room420increases relatively higher than the first room410. Accordingly, the outlet opening/closing member520closes the chamber communicating unit430by the pressure and the weight of the second room420. On the other hand, if the pressure of the first room410increases by the bellows unit310, the pressure of the second room420decreases relatively lower than the pressure of the first room410. The outlet opening/closing member520floats and is separated from the chamber communicating unit430because of being pressurized from the first room410through the chamber communicating unit430, to thereby open the chamber communicating unit430. Herein, the flow of the fog which moves to the second room420from the first room410through the chamber communicating unit430helps the outlet opening/closing member410float.

The fog receiving unit600receives the fog exhaled from the outlet unit421. The fog receiving unit600has the outlet pipe610connected to the outlet unit421so that the fog exhaled from the outlet unit421can be directed to the fog receiving unit600.

A collecting process of the fog in the image forming apparatus1with this configuration according to an exemplary embodiment of the present general inventive concept will be described with reference toFIG. 1throughFIG. 3B.

If the spitting process begins, the spitting unit200moves to the lower part of the cartridge100to face the nozzle unit110. The cartridge100ejects a predetermined amount of the ink stored in the inner part thereof. The ejected ink is collected by the spitting unit200. During this process, the ink scattered from the spitting unit200generates large amount of fog.

The bellows unit310is expanded by operating the driving unit330. By this, the pressure of the first room410decreases, and the pressure of the second room420increases relatively higher than the pressure of the first room410. With this, the inlet opening/closing member510opens the inlet unit411, the outlet opening/closing member520closes the chamber communicating unit430. The fog is inhaled along the inlet pipe210and is directed to the first room410. Part of the fog directed to the first room410may be directed to the chamber connecting pipe320. Also, since the chamber communicating unit430is closed, the fog of fog receiving unit600can be prevented from being directed to the first room410. (Refer toFIG. 3A)

The bellows unit310is compressed by the driving unit330. The pressure of the first room410increases and the pressure of the second room420decreases relatively lower than the pressure of the first room410. The inlet opening/closing unit510pressurized by the pressure of the first room410closes the inlet unit411and the outlet opening/closing member520opens the chamber communicating unit430. The fog directed to the first room410when the bellows unit310is expanded, is prevented from being exhaled to the inlet pipe210because of closing the inlet unit411. According to the compression of the bellows unit310, the part of the fog directed to the chamber connecting pipe320is exhaled to the first room410, is directed to the second room420with the fog of the first room410, is exhaled through the outlet unit421, and is collected to the fog receiving unit600along the outlet pipe610. (Refer toFIG. 3B)

Hence, by repetitively expanding and compressing the bellows unit310, the fog generated in a peripheral region of the spitting unit200is repetitively collected to the fog receiving unit600through the chamber400.

Another exemplary embodiment of the present general inventive concept is different from the first embodiment with respect to an air pressure generating unit and a chamber, which is described below omitting description of similar components to avoid repetitive descriptions.

As illustrated inFIG. 1andFIG. 4toFIG. 6, an image forming apparatus1according to another exemplary embodiment of the present general inventive concept may include an air pressure generating unit300, a chamber400, and a valve unit500.

The air pressure generating unit300may include a cylinder340, a piston350to reciprocate in the cylinder340, and a driving unit330to reciprocate the piston350.

The cylinder340can be hollow and airtight from the outside. The chamber connecting pipe320is provided on one side of the space whose air is expanded and compressed according to the reciprocating motion of the piston350. According to the reciprocating motion of the piston350, an inner air of the cylinder340is expanded and compressed, and a pressure of the chamber inner space440(to be described later) increases and decreases through the chamber connecting pipe320.

One side of the piston350is connected to the driving unit330so that the piston350can be reciprocated by the driving of the driving unit330within the cylinder340. The piston350expands and compresses the inner air of the cylinder340by the reciprocating motion thereof. For example, the inner air of the cylinder340is expanded when the piston350moves backward, and the inner air of the cylinder340is compressed when the piston350moves forward.

The chamber400may include a chamber inner space440, an inlet valve receiving unit450to receive an inlet valve unit530(to be described later), an outlet valve receiving unit460to receive an outlet valve unit540(to be described later), and a valve receiving slit470to be provided between the inlet valve receiving unit450and the outlet valve receiving unit460to mount the valve unit500.

The chamber inner space440can be formed by the space of an inner part of the chamber400. The chamber connecting pipe320connected to the cylinder340passes through one side of the chamber inner space440so that the inner pressure of the chamber inner space440is changed by the reciprocating motion of the piston350. For example, the pressure of the chamber inner space440decreases if the inner air of the cylinder340is expanded. The pressure of the chamber inner space440increases if the inner air of the cylinder340is compressed.

The inlet valve receiving unit450is spaced apart from the chamber inner space440and is formed in the chamber400. A fog inlet451connected to the inlet pipe210is formed on one side of the inlet valve receiving unit450. Also, a chamber inlet453which communicates with the chamber inner space440is formed on a flowing channel to direct the fog from the fog inlet451. Herein, the chamber inlet453is provided in a place where the inhaled fog can freely move to chamber inner space440when the fog inlet451is opened by the inlet valve unit530(to be described later).

The outlet valve receiving unit460can be formed in the chamber400while being spaced apart from both the chamber inner space440and the inlet valve receiving unit450. A chamber outlet461which communicates with the chamber inner space440can be formed on one side of the outlet valve receiving unit460. Also, a fog outlet463connected to the outlet pipe610can be formed on the flowing channel to exhale the fog from the chamber outlet461. Herein, the fog outlet463can be provided in a place where the fog can be exhaled to the outlet pipe610when the outlet valve unit540(to be described later) opens the chamber outlet461.

The valve receiving slit470is provided between, and communicates with, the inlet valve receiving unit450and the outlet valve receiving unit460, so that the valve unit500can be mounted in the chamber400. The valve receiving slit470allows the inlet valve unit530(to be described later) and the outlet valve unit540to be mounted to the inlet valve receiving unit450and outlet valve receiving unit460respectively, at once, when the valve unit500formed as a single board is mounted to the chamber400. By this, an ease of assembly of the valve unit500in the chamber400can be improved. Herein, a size of the valve receiving slit470is determined to maintain air-tightness between the inlet valve receiving unit450and the outlet valve receiving unit460, and space them apart from each other when the valve unit500is installed.

The valve unit500can be formed as a single board which is accommodated in and mounted to the inlet valve receiving unit450, the valve receiving slit470, and the outlet valve receiving unit460. The inlet valve unit530and the outlet valve unit540are formed on the board of the valve unit500with a predetermined distance therebetween.

The inlet valve unit530is coupled to the inlet valve receiving unit450, and opens/closes the fog inlet451. The inlet valve unit530may include an inlet valve fastened end531and an inlet valve free end533to move by a predetermined distance with respect to the inlet valve fastened end531.

The inlet valve free end533moves within the inlet valve receiving unit450by the predetermined distance when the pressure of the chamber inner space440decreases, thereby opening the fog inlet451. By this, the fog inhaled to the fog inlet451is directed to the chamber inner space440via the chamber inlet453.

A diameter of the inlet valve free end533can be larger than the fog inlet451. By this, when the pressure of the chamber inner space440increases, the inlet valve free end533pressurized by the pressure closes the fog inlet451, so that the fog of the chamber inner space440can be prevented from being exhaled into the inlet pipe210.

The outlet valve unit540is coupled to the outlet valve receiving unit460, and opens/closes the chamber outlet461. The outlet valve unit540includes an outlet valve fastened end541and an outlet valve free end543to move at the predetermined distance toward the outlet valve fastened end541.

When the pressure of the chamber inner space440increases, the outlet valve free end543moves within the outlet valve receiving unit460at the predetermined distance and opens the chamber outlet461. By this, the fog of the chamber inner space440is exhaled along the outlet pipe610through the fog outlet463.

The diameter of the outlet valve free end543can be larger than the chamber outlet461. By this, when the pressure of the chamber inner space440decreases, the outlet valve free end543closes the chamber outlet461so that the fog of the fog receiving unit600is prevented from being directed to the chamber inner space440.

A process to collect fog according to the above exemplary embodiment of the present general inventive concept is described referring toFIG. 1andFIGS. 4 to 6.

If the fog is generated in the spitting unit200, the inner air of the cylinder340is alternately expanded and compressed by the reciprocating motion of the piston350. According to this, the pressure of the chamber inner space440is changed.

The pressure of the chamber inner space440decreases if the piston moves backward. Thus, the inlet valve unit530opens the fog inlet451, and the fog is inhaled along the inlet pipe210and is directed to the chamber inner space440through the fog inlet451, the inlet valve receiving unit450, and chamber inlet453.

If the pressure of the chamber inner space440decreases, the pressure of the outlet valve receiving unit460increases higher than the pressure of the chamber inner space440so that the outlet valve unit540can close the chamber outlet461by the pressure of the outlet valve receiving unit460. Accordingly, the fog of the fog receiving unit600is prevented from being directed to the chamber inner space440through the outlet pipe610(Refer toFIG. 5A).

If the piston350moves forward, the pressure of the chamber inner space440increases. The inlet valve unit530closes the fog inlet451by the pressure so that the fog of the chamber inner space440can be prevented from being exhaled into the inlet pipe210. Also, the outlet valve unit540opens the chamber outlet461, the fog of the chamber inner space440is exhaled to the fog receiving unit600through the chamber outlet461, the outlet valve receiving unit460, and the fog outlet463along the outlet pipe610(Refer toFIG. 5B).

The pressure of the chamber inner space440is changed by the reciprocating motion of the piston350. Accordingly, the fog is repetitively inhaled and exhaled through the chamber400.

As the above description, the present general inventive concept provides an image forming apparatus, which is capable of collecting the fog generated at the spitting process by various configurations of an air pressure generating unit300, chamber400, and a valve unit500without difficulty. In addition, as the above description, configurations of an image forming apparatus according to the present general inventive concept may vary by those skilled in the art.

As described above, the present general inventive concept provides an image forming apparatus which collects a fog generated in the image forming apparatus to prevent an inner part of the apparatus from being polluted, and to guarantee a quality of an image formed on a record material. Also, the simple configuration of the image forming apparatus increases an ease of assembly and productivity and improves a reliability of the product.