Image forming apparatus

An image forming apparatus is disclosed that includes a maintenance recovery mechanism for maintaining and restoring a condition of a recording head. An opening larger than an outline of a frame of the maintenance recovery mechanism is formed in a side plate to which an end of a guide rod is attached. The frame of the maintenance recovery mechanism is secured and held at the upper side of the opening. The maintenance recovery mechanism can be removed in a scanning main direction through the opening of the side plate.

BACKGROUND

1. Technical Field

The invention disclosure relates to an image forming apparatus, and particularly relates to a recording head that ejects recording ink.

2. Description of the Related Art

Inkjet recording apparatuses are used as image forming apparatuses such as printers, fax machines, copy machines, and plotters. A serial type image forming apparatus is one of the inkjet recording apparatuses, and is configured to form (records) images on a medium to be recorded on (which includes recording paper, transfer paper and other recording media and is hereinafter referred to as “sheet” although the material is not limited to paper) using a droplet ejection head or a recording head that is mounted on a carriage for ejecting recording liquid (e.g. ink) from a nozzle while moving the carriage in a main scanning direction.

This type of inkjet recording apparatus has been mainly used as a single-function apparatus such as a printer for personal use. If a carriage of such an inkjet recording apparatus having a recording head mounted thereon gets out of order, the apparatus is sent to a repair shop so as to be disassembled for repairing or replacing the carriage.

In these years, so-called multi-function image forming apparatuses having two or more of a printer function, a fax machine function, and a copy machine function are being developed and coming into practical use. Different from single-function apparatuses, multi-function type image forming apparatuses can not be easily sent to repair shops. Therefore, multi-function apparatuses are preferably configured such that a service person can make repairs on-site by replacing parts.

An example of image forming apparatuses that allow part replacement is disclosed in Patent Document 1, which comprises detachable plural blocks. Each block is responsible for a specific function and has connection means to be connected to the other blocks. The blocks are classified into plural groups according to the configuration of the connection means. The blocks in the same groups have the same type connection means. One block having a desired function is selected from each group, and the selected blocks are connected to each other through the connection means.

In the above-described image forming apparatus, a maintenance recovery mechanism for maintaining and restoring a condition of a recording head is formed as a block integral with a recovery block including a suction cap, a blade, a recovery motor, and a recovery pump. The recovery block can be removed by being pulled out to the upper side from the apparatus body.

Generally, in image forming apparatuses provided with a carriage having a recording head mounted thereon, a guide rod (guide shaft) for guiding the carriage in a main scanning direction is provided to extend between a pair of opposing side plates, and a maintenance recovery mechanism for maintaining and restoring a condition of the recording head is arranged under the guide rod.

As a method for locating a home position of a carriage, a system as disclosed in Patent Documents 2 and 3 is often employed. This system causes a carriage to hit against a side plate holding an end of a guide rod and, with reference to this hitting position, move the carriage to a home position by performing predetermined operations.

Turning back to the image forming apparatus disclosed in Patent Document 1, when the recovery block is removed for the purpose of replacement (including repair), a carriage block integrally including a carriage and a guide shaft needs to be removed before removing the recovery block. This is because the image forming apparatus is configured such that the recovery block is removed via the upper side. Similarly, in the case of the image forming apparatus disclosed in Patent Document 2, it is impossible to remove only the maintenance recovery mechanism.

As can be seen, the image forming apparatuses as described above are not designed with enough consideration for on-site maintenance, and are not convenient from the standpoint of maintenance.

BRIEF SUMMARY

The present disclosure provides an image forming apparatus on which maintenance can be performed with ease.

According to an aspect of the present disclosure, in an image fanning apparatus, an opening larger than an outline of a frame of a maintenance recovery mechanism is formed in a side plate, to which a guide rod is attached, such that the maintenance recovery mechanism can be removed through the opening.

Preferably, the frame of the maintenance recovery mechanism is detachably secured to the side plate at the upper side of the opening. It is also preferable that an end of the guide rod be attached to the side plate at the upper side of the opening. It is also preferable that a cover of an apparatus body be detachably attached to an outer side of the side plate. The image forming apparatus preferably further comprises an image reading unit, and an image forming unit including a recording head.

In above-described image forming apparatus, because the opening larger than the outline of the frame of the maintenance recovery mechanism is formed in the side plate to which the guide rod is attached, the maintenance recovery mechanism can be removed to the outside through the opening. Therefore, the maintenance of the image forming apparatus can be performed with ease.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

In the following description, provides examples and exemplary embodiments of the present invention are provided with reference to the accompanying drawings. An example of an image forming apparatus according to the present invention is described below referring toFIGS. 1 through 4.FIG. 1is a schematic diagram illustrating the configuration of the image forming apparatus.FIG. 2is a schematic diagram illustrating an image forming section2and a sub scanning transport section3of the image forming apparatus.FIG. 3is a side view of the sub scanning transport section.

In this image forming apparatus, the image forming section (unit)2for forming images and the sub scanning transport section (unit)3are provided inside (in a casing) of an apparatus body1. A sheet feed section (unit)4disposed at the bottom of the apparatus body1feeds a medium5to be recorded on as a member to be transported (hereinafter referred to as “sheet” although the material is not limited to paper) one by one. The sheet5is intermittently transported by the sub scanning transport section3while facing the image forming section2. The image forming section2ejects droplets onto the sheet5to form (record) images thereon. The sheet5is then ejected to a catch tray7provided on an upper face of the apparatus body1through a sheet eject transport section6.

The image forming apparatus comprises an image reading section (scanner section)11adapted to read images at the upper part of the apparatus body1on the upper side of the catch tray7. The image reading section11serves as an input system for inputting image data (print data) to be formed by the image forming section2. In the image reading section11, a scanning optical system15including an illumination light source13and a mirror14and another scanning optical system18including mirrors16and17move to read images of a document placed on a contact glass12, and the scanned document is read as image signals by an image reading element20arranged at the rear side of a lens19. The read image signals are digitized and processed into print data, and the print data are printed out. A pressure plate10for holding the document is provided on the contact glass12.

The image forming apparatus can receive print data including image data through a cable or a network from host devices, i.e., information processing devices such as personal computers, image reading devices such as image scanners, and imaging devices such as digital cameras. The received print data are processed and printed out.

Referring toFIG. 2, in the image forming section2of the image forming apparatus, a carriage23is held by a guide rod21and a guide stay (not shown) so as to be movable in a main scanning direction. The carriage23is moved in the main scanning direction by a main scanning motor27through a timing belt29extending around a drive pulley28aand a driven pulley28b.

A recording head24is installed on the carriage23. While the carriage23is reciprocally moved in the main scanning direction, the recording head24ejects droplets so as to form images on the sheet5being transported in a sheet transport direction (sub scanning direction) by the sub scanning transport section3.

The recording head24comprises five droplet ejection heads, i.e., two droplet ejection heads24k1and24k2for ejecting a black (Bk) ink, and droplet ejection heads24c,24m, and24yfor ejecting a cyan (C) ink, a magenta (M) ink, and a yellow (Y) ink, respectively (hereinafter the droplets ejection heads are referred to as simply “heads”). The inks are supplied from corresponding sub-tanks25(FIG. 1) mounted on the carriage.

Referring back toFIG. 1, ink cartridges26storing the black (K) ink, the cyan (C) ink, the magenta (M) ink, and the yellow (Y) ink, respectively, are detachably attached to a cartridge mount section26A from the front side of the apparatus body1. The inks in the ink cartridges26are supplied to the corresponding sub-tanks25. The black ink is supplied from one of the ink cartridges26to the two of the sub-tanks25.

The type of recording head24applicable herein includes: a piezo type head that applies pressure to ink in an ink passage (pressure generation chamber) by using a piezoelectric element provided as a pressure generating unit (actuator unit), deforms a wall of the ink passage, changes the volume of the ink passage, and thus ejects ink droplets; a thermal type head that heats ink in an ink passage to form bubbles by using a heating element, and thus ejects the ink with pressure generated by the formation of the bubbles; and an electrostatic type head that provides a diaphragm on a wall of an ink passage and an electrode opposing the diaphragm, deforms the diaphragm with static electricity generated between the diaphragm and the electrode, changes the volume of the ink passage, and thus ejects ink droplets.

With reference toFIG. 2, a maintenance recovery mechanism121including a head cleaning unit for maintaining and restoring the condition of a nozzle of the recording head24is provided in a non-printing area located at one side in a scanning direction of the carriage23. The maintenance recovery mechanism121comprises five dry-proof caps122k2,122k1,122c,122mand122y(which are referred to as “dry-proof caps122” if ignoring the colors thereof) for capping nozzle faces of the recording head24, a suction cap123, a wiper blade124for wiping the nozzle faces of the recording head24, an idle ejection receiver125for idle ejection not intended to record (form) images, and a carriage block member (not shown).

Another idle ejection receiver (idle ejection receiving member)126for idle ejection not intended to record (form) images is provided in a non-printing area located at the other side in the scanning direction of the carriage23. The idle ejection receiver126has five openings127k2,127k1,127c,127m, and127y(which are referred to as “openings127” if ignoring the colors thereof) corresponding to the recording head24.

The sub scanning transport section3comprises a transport roller32as a drive roller for changing a transport direction of the sheet5fed from the lower side by 90 degrees such that the sheet5is transported facing the image forming section2, a driven roller33, an endless transport belt31extending around the transport roller32and the driven roller33, a charging roller34as a charging unit to which a high voltage (alternating current) is applied from a high-voltage power supply in order to charge the surface of the transport belt31, a guide member35that guides the transport belt31within an area opposing the image forming section2, a pressure roller36that presses the sheet5against the transport belt31at a position opposing the transport roller32, a separation claw37that separates the sheet5on which images are formed from the transport belt31, and transport rollers38that send the sheet5separated from the transport belt31to the sheet eject transport section6.

Referring toFIG. 3, as the transport roller32is rotated through a timing belt132and the timing roller133by the sub scanning motor131, the transport belt31of the sub scanning transport section3is rotated to transport the sheet5in the sheet transport direction (sub scanning direction) of the single-headed arrow inFIG. 2. Although the transport belt31has a double layer structure including a front surface (sheet adhesion face) made of a pure resin material, such as pure ETFE material, with no resistance control, and a back side (middle resistance layer, grounding layer) made of the same material as the front layer but with resistance control by carbon, the transport belt31may have a single layer structure or a structure having three or more layers.

A cleaning unit (made of Mylar (trademark) in this embodiment)135for removing paper powder adhered on the surface of the transport belt31and a discharging brush136for discharging the surface of the transport belt31are provided between the driven roller33and the charging roller34.

The sheet feed section4, which can be loaded into and unloaded from the apparatus body1, comprises a sheet cassette41for stacking and storing multiple sheets5therein, a sheet feed roller42and a friction pad43for sending the sheets5stored in the sheet cassette41one by one, and a sheet feed transport roller44for transporting the sheet5to the sub scanning transport section3. The sheet feed roller42is rotated by a sheet feed motor (drive source)45including an HB stepping motor through a sheet feed clutch (not shown). The sheet feed transport roller44is also rotated by the sheet feed motor45.

The sheet eject transport section6comprises sheet eject transport roller pairs61and62for transporting the sheet5on which images are formed, and sheet eject transport roller pairs63and64for sending the sheet5to the catch tray7.

The following section provides an overview of a control section300of the image forming apparatus with reference toFIG. 4.

The control section300comprises a CPU301that controls the apparatus, a ROM302storing programs executed by the CPU301and other fixed data, a RAM303that temporarily stores image data and the like, a nonvolatile memory (NVRAM)304that retains data even when power is removed, an ASIC305that processes various signals for image data and processes input/output signals for processing or reordering images and for controlling the apparatus, and a scanner controller306.

The control section300section further comprises an I/F307that transmits and receives signals and data to and from the host devices, a head drive controller308and a head driver309that control and drive the recording head24, a main scanning motor driver311that drives the main scanning motor27, a sub scanning motor driver312that drives the sub scanning motor131, a sheet feed motor driver313that drives the sheet feed motor45, a maintenance recovery system driver314that drives a motor431(described below) for operating the maintenance recovery mechanism121, an AC bias supply section316that supplies a varying voltage (rectangular wave) as a power for enabling the charging roller34to charge the transport belt31, and other components (not shown) that drive motors for an ink supply system and clutches including the sheet feed clutch.

The control section300further comprises an I/O317for inputting detection signals thereinto from various sensors such as a print start sensor that detects, in the upstream of the recording head24, the sheet5which has passed through between the transport roller32and the pressure roller36, a print end sensor that detects the sheet5downstream of the transport rollers38, a home position sensor (not shown) of the maintenance recovery mechanism121, a sensor that detects ambient temperature and humidity, and a sensor that detects a cover of the apparatus being opened. An operations panel318that inputs necessary information to the apparatus and displays information is connected to the control section300.

The control section300receives, at the I/F307, print data through a cable or a network from the host devices, i.e., information processing devices such as personal computers, image reading devices such as image scanners, and imaging devices such as digital cameras.

The CPU301reads and analyzes the print data held in a receive buffer of the I/F307. Then, the ASIC305performs image processing and data reordering and sends image data to the head drive controller308. Dot pattern data for outputting images may be generated using font data, which may be stored in the ROM302. Alternatively, image data may be expanded into bit map data by a printer driver at a host side before being transmitted to the apparatus.

The head drive controller308receives image data (dot pattern data) corresponding to one line for the recording head24, and sends the received dot pattern data corresponding to one line as serial data to the head driver309synchronously with clock signals. The head drive controller308also sends latch signals to the head driver309with a predetermined timing. The head drive controller308comprises a ROM (or the ROM302) storing pattern data of drive waveforms (drive signals), and a drive waveform generation circuit including an amplifier and a waveform generation circuit having a D/A converter for performing D/A conversion of the data of drive waveforms read from the ROM.

The head driver309comprises a shift register that inputs the clock signals and the serial data as the image data from the head drive controller308, a latch circuit that latches the registration value of the shift register with the latch signals from the head drive controller308, a level change circuit (level shifter) that changes the level of the output value of the latch circuit, and an analog switch array (switch unit) that is turned on/off by the level shifter. By turning on/off the analog switch array, a desired drive waveform included in the drive waveforms is selectively applied to the actuator unit of the recording head24to drive the recording head24.

The control section300causes the AC bias supply section316to apply a predetermined variable voltage to the charging roller34such that the charging roller34charges the transport belt31to generate a predetermined attraction force for attracting the sheet5when the transport belt31transports the sheet5. Also, at a predetermined timing, the control section300causes the AC bias supply section316to apply another predetermined variable voltage (or a frequency) to the charging roller such that the charging roller34charges the transport belt31to generate an attraction force smaller than an attraction force to be generated without the variable voltage being applied.

In the image forming apparatus with the above-described configuration, the charging roller34abuts an insulating layer (front layer) of the transport belt31when a bipolar rectangular wave high voltage as an variable voltage is applied from the AC bias supply section316to the charging roller34. Therefore, positive charges and negative charges are alternately applied to the front layer of the transport belt31in the transport direction of the transport belt31so as to form charged strips with a predetermined width. As a result, a non-uniform electric field is formed on the transport belt31.

When the sheet5sent from the sheet feed section4passes through between the transport roller32and the pressure roller36onto the transport belt31on which the non-uniform electric field is generated by positive and negative charges, the sheet5is instantaneously polarized along a direction of the electric field and is adhered onto the transport belt31due to an electrostatic attraction force. Thus, the sheet5is transported along with the movement of the transport belt31.

While the sheet5is intermittently transported by the transport belt31, the recording head24ejects droplets of the recording liquid to record (print) images on the sheet5. After the image is printed on the sheet5, the separation claw37separates the front end of the sheet5from the transport belt31so that the sheet5is sent to the sheet eject transport section6by the transport rollers38.

The carriage23is moved to and stays at the side of the maintenance recovery mechanism121while standing by for a printing operation. An ejection hole face of the recording head24is capped by the dry-roof caps122for keeping an ejection hole section wet, thereby preventing poor ejection due to ink dryout. The recording head24performs idle ejection or ejects ink during a recording operation not for recording images but for equalizing the viscosity of the inks in all the ejection holes so as to maintain stable ejection performance.

If the ejection performance is lowered, an ejection hole (nozzle) of the recording head24is tightly capped by the suction cap123. Then, a suction unit suctions ink and bubbles from the ejection hole through a tube, and the cleaning unit removes ink and dust adhered to the ejection hole face. In this way, the ejection performance is restored. The suctioned ink is discharged to a waste ink reservoir arranged at the lower part of the apparatus body, and absorbed by an ink absorber in the waste ink reservoir.

The maintenance recovery mechanism121of the image forming apparatus is described below in detail with reference toFIG. 5andFIG. 6.FIG. 5is a schematic illustration of the maintenance recovery mechanism121, andFIG. 6is a perspective view of the maintenance recovery mechanism121.

The maintenance recovery mechanism121comprises cap holders421A through421D including a holder mechanism that holds the dry-proof caps122and the suction cap123(cap holders421A and421C each include two dry-proof caps122), the wiper blade124which is an elastic blade serving as a cleaning unit for cleaning (wiping) a nozzle face of the recording head24, and the idle ejection receiver125for idle ejection of droplets performed by the recording head24which is not intended to print images.

The suction cap123held by the cap holder421D, which is the cap closest to a printing area, is connected to a tubing pump (suction pump)423provided as a suction unit through a flexible tube422. For performing a maintenance recovery operation of the recording head24, one of the heads of the recording head24to have a recovery operation is moved to a position where it can be capped by the suction cap123.

A cam shaft412rotatably held by a frame411is arranged under the cap holders421A through421D. Cap cams413A through413D for lifting/lowering the cap holders421A through421D and a wiper cam414for lifting/lowering the wiper blade124are attached to the cam shaft412. Although the upper dead centers of the dry-proof caps122and the suction cap123are located at different heights, the dry-proof caps122, the suction cap123, and the cams413A through413D are located at the same height inFIG. 5for simplification of the drawing.

A carriage lock415that engages and locks the movement of the carriage23is provided. The carriage lock415is biased upward (in a locking direction) by a compression spring (not shown), and is lifted/lowered through a carriage lock arm417driven by a carriage lock cam416attached to the cam shaft412.

The tubing pump423and the cam shaft412are driven by having the following configuration. The motor431transfers its torque to a motor gear432attached to a motor shaft431a. The motor gear432meshes with a gear433attached to a pump shaft423aof the tubing pump423. A gear434integrally provided with the gear433meshes with a middle gear436having a one-way clutch437through a middle gear435. A middle gear438coaxially provided with the middle gear436meshes with a cam gear440fixed to the cam shaft412through a middle gear439.

In this maintenance recovery mechanism121, when the motor431rotates in a normal rotational direction, the motor gear432, the gears433and434and the middle gears435and436are rotated. When the shaft423aof the tubing pump423is rotated, the tubing pump423is operated to take suction inside the suction cap123(this operation is referred to as “cap inside suction”). The gears438through439are not rotated because the rotation is blocked by the one-way clutch437.

On the other hand, when the motor431rotates in the opposite direction, the one-way clutch437is connected. Therefore, the rotation of the motor431is transmitted to the cam gear440trough the motor gear432, the gears433and434and the middle gears435and436. As a result, the cam shaft412is rotated. The tubing pump423is configured to not rotate while the pump shaft423ais rotated in the opposite direction.

As previously mentioned, the recording head24is moved to a position where the recording head24of the carriage23is opposed by the corresponding dry-proof caps122. Then the cam shaft412is driven so the nozzle face of the recording head24is capped by the dry-proof caps122. When a recovery operation of the recording head24is performed, one of the heads the recording head24to have the recovery operation is moved to a position opposing the suction cap123. Then, the cam shaft412is rotated such that the suction cap caps the nozzle face of the recording head24, and the tubing pump423suctions inside the ejection hole of the recording head24.

The following describes a configuration for replacing the maintenance recovery mechanism121referring toFIGS. 7 through 9.FIG. 7is a side view illustrating a positional relation between the maintenance recovery mechanism121and a side plate501A.FIG. 8is a side view illustrating the apparatus body1.FIG. 9is a perspective view illustrating the apparatus body1.

Referring toFIG. 7, the guide rod21, which guides a main scanning operation of the carriage23, is attached at its ends to side plates501A and501B (FIG. 2). An end21aof the guide rod21has a substantially semicircular cross section. The end21ais attached to a holder member503rotatably held by an adjuster plate502fixed to the side plate501A such that the height of the guide rod21or the distance between the carriage23and the sheet5can be adjusted by rotation of the holder member503.

The side plate501A has an opening511larger than the outline of the frame411of the maintenance recovery mechanism121at the lower side of a part where the guide rod21is attached so as to allow the maintenance recovery mechanism121to be removed toward a lateral side of the side plate501A (lateral side of the apparatus body1) for the purpose of replacement or for other purposes. In other words, the opening511is formed that has a size larger than the outline of a lateral projected area of the maintenance recovery mechanism121. That is, the maintenance recovery mechanism121can pass through the opening511. The end21aof the guide rod21is attached to the side plate501A at the upper side of the opening511.

Flange sections411a(see alsoFIG. 6) are formed integrally on the upper side of the frame411of the maintenance recovery mechanism121. The flange sections411aare secured to an outer face of the side plate501A by fixing members512such as screws such that the maintenance recovery mechanism121is detachably secured to the side plate501A at the upper side of the opening511.

With this configuration, when the maintenance recovery mechanism121is removed toward the lateral side of the side plate501A for the purpose of repair and replacement, etc., of the maintenance recovery mechanism121, the fixing members512are removed to allow the maintenance recovery mechanism121to be separated from the side plate501A and pulled out in the lateral direction through the opening511of the side plate501A (in a direction indicated by an arrow A inFIG. 2). In this way, the maintenance recovery mechanism121can be removed.

As described above, by having an opening in a side plate larger than the outline of a frame of a maintenance recovery mechanism for removing the maintenance recovery mechanism toward the lateral side of the side plate, the maintenance recovery mechanism can be removed toward the lateral side (in a main scanning direction) without removing a guide rod and a carriage. This facilitates maintenance work including repair and replacement of the maintenance recovery mechanism.

By detachably attaching the frame of the maintenance recovery mechanism to the upper side of the opening, a positional relation between the carriage and the maintenance recovery mechanism can be stably maintained. Also by holding the end of the guide rod on the side plate at the upper side of the opening, a positional relation between the carriage and the maintenance recovery mechanism can be stably maintained.

The image forming apparatus may employ a system that causes a part of the carriage23to hit against the side plate501A and detects that the carriage23has hit an object based on a signal change of the main scanning motor27and, with reference to this hitting position, moves the carriage23for a predetermined distance to a position, which is determined as a home position.

In this case, if the side plate501A is deformed (but can be restored) when hit by the carriage23, a positional relation between the home position of the carriage23and the maintenance recovery mechanism121might be changed. If the positional relation between the home position of the carriage23and the maintenance recovery mechanism121is changed, the positional relation between the recording head24of the carriage23and the dry-proof caps122or the suction cap123might be also changed.

When the relatively large opening511as described above for the removal of the maintenance recovery mechanism121is formed in the side plate501A, the strength of the side plate501is lower compared to the one without the opening511. If the maintenance recovery mechanism121is secured to the side plate501A at the lower side of the opening511and the side plate501A is deformed when hit by the carriage23for home position detection, a larger change of the positional relation between the home position of the carriage23and the maintenance recovery mechanism121is caused.

To avoid such a problem, the maintenance recovery mechanism121is secured to the side plate501at the upper side of the opening511, and the end of the guide rod21is held by the side plate501A at the upper side of the opening511. With this configuration, even if the side plate501A is deformed when the carriage23hits the side plate501A at the upper side of the opening511, a big change in the positional relation between the home position of the carriage23and the maintenance recovery mechanism121can be prevented. When the maintenance recovery mechanism121is secured to the side plate501at the upper side of the opening511and the end of the guide rod21is held by the side plate501at the upper side of the opening511, the guide rod21is located close to a position where the maintenance recovery mechanism121is fixed. Accordingly, the change in the positional relation between the home position of the carriage23and the maintenance recovery mechanism121can be further minimized.

The following describes how engagement between the maintenance recovery mechanism121and the carriage23is released, referring toFIG. 8.

When the image forming apparatus is turned off, the carriage23is automatically moved toward the maintenance recovery mechanism121and locked by the carriage lock415. Then, the ejection hole face of the recording head24is capped by the dry-proof caps122of the maintenance recovery mechanism121.

When there is a need to remove the maintenance recovery mechanism121for the purpose of replacement or repair, etc., the engagement between the maintenance recovery mechanism121and the carriage23needs to be released for a smooth removal of the maintenance recovery mechanism121. If the maintenance recovery mechanism121is removed by force without releasing the engagement, the ejection hole face of the recording head24might be damaged by friction with the dry-proof caps122.

The maintenance recovery mechanism121is therefore configured such that the lock of the carriage and the capping of the recording head24are manually released. More specifically, with reference toFIG. 8, an end of a middle shaft441, to which the clutch437is attached that transfers a drive force to the cam shaft412for vertically moving the caps122, is exposed on the surface of the frame411. A groove (which may be a recess or a projection without being limited to a groove)442to which a rotational operation member can be fitted is formed at the end of the middle shaft441.

By fitting the rotational operation member such as a driver to the groove442of the middle shaft441and rotating the middle shaft441, the cam shaft412is rotated. Thus, the carriage lock415is lowered, so the lock is released. Also, the caps122are brought out of the tight contact with the recording head24. With these operations, the maintenance recovery mechanism121is removed.

Further, a mark443indicating a rotational direction is formed on a portion of the frame411near the middle shaft441in order to prevent the maintenance recovery mechanism121from being damaged due to rotation in a wrong direction. An end of the cam shaft412is also exposed on the surface of the frame411. The position of the cam shaft412or the rotated amount of the cam shaft412is indicated by a mark444formed on an end face of the cam shaft412and a mark445formed on the surface of the frame411near the cam shaft412.

With this configuration, a user can know how much and in which direction to rotate the cam shaft412. Therefore, the user can correctly rotate the cam shaft412with ease to bring the recording head24and the caps122out of tight contact.

As described above, by having a maintenance recovery mechanism adapted to maintain a condition of the recording head and provided with a lock member for locking a carriage and a cap member, and by forming a groove or a projection at an end of a cam shaft of the maintenance recovery mechanism or a shaft connected to the cam shaft that lifts/lowers the lock member and the cap member, it is possible to release the lock of the carriage and bring the recording head and the cap member out of tight contact by manually rotating the cam shaft even when the power is not supplied.

The exterior of the image forming apparatus is described below in detail with reference toFIGS. 9 and 10.

The maintenance recovery mechanism121can be pulled out through the side plate501A laterally in the main scanning direction as described above. In order to further pull out the maintenance recovery mechanism121to the outside of the apparatus body1, a detachable exterior cover602is provided on a cover601at the rear side of the apparatus body1as shown inFIGS. 9 and 10. The exterior cover602is arranged at a position opposing the maintenance recovery mechanism121and a waste liquid tank600for holding waste liquid discharged from the maintenance recovery mechanism121.

When the exterior cover602is detached from the cover601, the maintenance recovery mechanism121and the waste liquid tank600arranged at the rear side of the apparatus body1are exposed as shown inFIG. 10. Therefore, the maintenance recovery mechanism121can be removed to the outside by separating the maintenance recovery mechanism121from the side plate501A and pulling out the maintenance recovery mechanism121through the opening511.

While the image forming apparatus exemplified in the above embodiment is the multifunction type image forming apparatus comprising an image reading unit, other types of image forming apparatuses and image forming apparatuses that use recording liquid other than ink may be applicable as the image forming apparatus of the present invention.

The present application is based on Japanese Priority Application No. 2004-260667 filed on Sep. 8, 2004, with the Japanese Patent Office, the entire contents of which are hereby incorporated by reference.