Image recording apparatus

There is disclosed an image recording apparatus having a lower body portion, an upper body portion, a guide, a first engager disposed in the upper body portion, and a second engager disposed in the guide. The lower body portion includes a curved feed pathway, an image recording device, and a recording medium feeder which feeds one by one a plurality of recording media as stacked, into the feed pathway and toward the image recording device. The upper body portion includes an image reading device which portion is disposed above the lower body portion and openable with respect to the lower body portion by being displaced upward. The guide which defines at least a part of the feed pathway, and is removably placed on the lower body portion. The first engager is engageable with the second engager so as to prevent the guide from coming off of the apparatus at least in a direction to an external side of the apparatus, while the upper body portion is closed with respect to the lower body portion.

INCORPORATION BY REFERENCE

The present application is based on Japanese Patent Application No. 2004-296909, filed on Oct. 8, 2004, the content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an image recording apparatus comprising: a lower body portion such as a mainbody housing incorporating an image recording portion, to which a medium supply cassette accommodating a stack of recording media is detachably attached, so that the recording media is supplied one by one from the medium supply cassette such that a topmost one of the stack of the recording media is separated from the other recording media; an upper body portion such as an upper casing incorporating an image reading device, which is pivotally connected to the lower body portion; and a guide for feeding the recording medium as supplied from the medium supply cassette to the image recording portion along a pathway U-shaped sideways.

2. Description of Related Art

A conventional image recording apparatus, such as copy machine, printer, and facsimile machine, comprises a mainbody housing incorporating an image recording portion and a recording medium feeder including a feeder roller, and an upper casing incorporating an image reading device and disposed on the mainbody housing, as disclosed in JP-A-8-188294 (especiallyFIGS. 1 and 2). A medium supply cassette accommodating a stack of recording media such as cut paper sheets on which image is to be recorded is detachably attached to a lower portion of the mainbody housing, and the feeder roller of the recording medium feeder is rotated to sequentially separate a topmost one of the recording media stacked in the medium supply cassette from the others to feed the recording media one by one to the image recording portion.

The recording medium feeder disclosed in the above-mentioned is constructed such that the feeder roller is disposed above the medium supply cassette, and a guide which is U-shaped sideways as seen from a lateral side and disposed at the side of an end of the medium supply cassette on the downstream side in a direction of the feeding of recording medium so as to feed each recording medium in the form of a paper sheet or others while U-turning and reversing the recording medium toward an image recording portion disposed above the medium supply cassette to record an image on the recording medium fed thereto. A lower end of the U-turn guide is connected to and supported by a mainbody housing such that the U-turn guide is pivotable about a lateral shaft. When a recording medium is caught around the feeder roller or other places, the U-turn guide is turned toward the external side of the mainbody housing so as to form a wide space between the U-turn guide and the feeder roller.

Since the U-turn guide is pivotably supported only at the lower, proximal end portion thereof, the U-turn guide tends to come off of the mainbody housing when the recording medium having a resistance to being bent presses the U-turn guide while being reversed along the guide. Hence, it is required to dispose a lock mechanism in some form for locking the U-turn guide to the mainbody housing.

Requiring an unlocking mechanism, too, the above-described arrangement where the lock mechanism is provided to lock the U-turn guide to the mainbody housing leads to an increase in the number of components of the apparatus. Where the U-turn guide and the mainbody housing are formed of a synthetic resin, it may be contemplated to form the lock mechanism integrally with at least one of the U-turn guide and the mainbody housing, so as to prevent this problem. However, this complexities the configuration of a mold used for forming the U-turn guide and/or the mainbody housing.

Further, where the lock mechanism is not a well-designed one, the guide rattles every time a recording medium passes along the U-turn guide, thereby deteriorating the stability in the feeding of recording medium, that is, a recording medium may be obliquely fed, or caught to cause a jam.

SUMMARY OF THE INVENTION

This invention has been developed in view of the above-described situations, and it is therefore an object of the invention to provide an image recording apparatus which is simple in structure, has a U-turn guide which does not easily come off, and is capable of feeding a recording medium without suffering from a jam caused by the recording medium caught in the apparatus.

To attain the above object, the invention provides an image recording apparatus comprising a lower body portion, an upper body portion, a guide, a first engager disposed in the upper body portion, and a second engager disposed in the guide. The lower body portion includes a curved feed pathway, an image recording device, and a recording medium feeder which feeds one by one a plurality of recording media as stacked, into the feed pathway and toward the image recording device. The upper body portion includes an image reading device which portion is disposed above the lower body portion and openable with respect to the lower body portion by being displaced upward. The guide which defines at least a part of the feed pathway, and is removably placed on the lower body portion. The first engager is engageable with the second engager so as to prevent the guide from coming off of the apparatus at least in a direction to an external side of the apparatus, while the upper body portion is closed with respect to the lower body portion.

By this arrangement, while the upper body portion is closed with respect to the lower body portion, that is, while the upper body portion is placed adjacent to the lower body portion, the first and second engagers cooperate to prevent the guide disposed in the lower body portion from coming off of the apparatus. That is, while the upper body portion is closed with respect to the lower body portion, the first and second engagers may or may not be held in contact with each other, but at least when the guide is prevented from coming off, the first and second engagers engage, namely, contact each other.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Hereinafter, there will be described several presently preferred embodiments of the invention, by referring to the accompanying drawings.

First, referring toFIGS. 1-12, there will be described an image recording apparatus according to a first embodiment of the invention. InFIG. 1, reference numeral1generally denotes the image recording apparatus of the first embodiment in the form of a MFD (Multifunction Device), which has at least two of the following functions: printer function, copy function, scanner function, and facsimile function. As shown inFIG. 1, a mainbody housing2constituting a lower body portion of the apparatus1comprises a first lower casing20and a second lower casing21connected to the under side of the first lower casing20.

The apparatus1can receive or accommodate two medium supply cassettes, namely, a first medium supply cassette3A (shown inFIGS. 4 and 6) and a second medium supply cassette3B disposed below the first medium supply cassette3A. That is, the first medium supply cassette3A is removably inserted into the first lower casing20of the mainbody housing2from a first front opening20aopen in a front face of the apparatus1, which is on the lower side inFIG. 1. The second medium supply cassette3B is removably inserted in the second lower casing21connected to the under side of the first lower casing20and disposed at the bottom of the apparatus1, from a second front opening21awhich is also open on the front face of the apparatus1.FIG. 1shows the state where the second medium supply cassette3B is accommodated in the mainbody housing2, but the upper, first medium supply cassette3A is removed from the mainbody housing2. In the description below, the side, portion, and end of the mainbody housing2and other components such as the first and second medium supply cassettes3A,3B, which are near the first and second front openings20a,21awill be referred to as front side, front portion, and front end, and the opposite side, portion, and end will be referred to as rear side, rear portion and rear end.

An upper casing9of synthetic resin constituting an upper body portion of the apparatus1is connected to the upper side of the mainbody housing2, such that the upper casing9is openable/closable relatively to the mainbody housing2by being turned upward/downward around an axis or a shaft9adisposed at a right-hand end of a rear side portion of the mainbody housing2, as seen inFIG. 2, of the mainbody housing2to extend in an X-axis direction as shown inFIG. 1. This arrangement facilitates operational work to eliminate paper jam, maintenance work for a recording portion7, and work for replacing an ink cartridge or cartridges (not shown), by enabling to widely open the upper casing9to perform such works. An image reading device for reading a document when a copy function or a facsimile function is activated is disposed in the upper casing9. The image reading device has a glass plate (not shown) on which a document sheet is placed, and a document cover structure13covering an upper surface of the glass plate. A rear end of the document cover structure is attached to a rear end of the upper casing9to be turnable upward and downward around a hinge12. At a left-hand side portion of an upper surface of the document cover structure, namely, a left-hand end portion thereof as seen inFIG. 1, there is disposed a document automatic feeder11for separating a topmost one from a stack of document sheets one by one to feed each separated document sheet to the reading portion and then eject the document sheet. In an upper front portion of the upper casing9, there is disposed an operator panel portion14where various operational buttons, a liquid crystal display and others are arranged, as shown inFIG. 1.

A document sheet is placed on the glass plate with a surface of the document sheet on which an image to be read is present facing downward, while the document cover structure is turned upward or opened. An image scanner for scanning documents in the form of a CIS (Contact Image Sensor), which is disposed to be reciprocable under the glass plate in a Y-axis direction shown inFIG. 1, reads the image on the document sheet. The Y-axis direction is a main scanning direction of the image scanner. On the other hand, when a stack of document sheets is set on a document supply table11aof the document automatic feeder11with a surface of each document sheet on which an image to be read is present facing upward, the document sheets are fed one by one downward along a U-turn pathway (not shown), so that the image on each document sheet is read at a document reading portion which corresponds to a left-hand end portion, as seen inFIG. 1, of the glass plate, and the read document sheets are ejected in order onto a document catch table13aconstituted by the upper surface of the document cover structure, with the surface with the image facing downward.

The recording portion7as shown inFIGS. 4 and 5is supported at a right side wall and a left side wall (not shown) of a main frame16which may be formed of metal. The recording portion7includes plate-like slide guiding members17,18extending in the Y-axis direction or the main scanning direction, a carriage5slidably mounted across or supported by the slide guiding members17,18to be reciprocable thereon, a timing belt (not shown) disposed parallel to and on an upper surface of the slide guiding member18to reciprocate the carriage5, a CR (carriage) motor (not shown) for driving the timing belt, and a flat platen19for supporting a recording medium P fed under a recording head4mounted on the carriage5.

A pair of registering rollers22are disposed on the upstream side, in a direction in which each recording medium P is fed (which will be hereinafter referred to as “feeding direction”), of the platen19, so as to nip a recording medium P therebetween to feed the recording medium P to a place under the recording head4. To the downstream side of the platen19, a gear roller and an ejection roller23are disposed to contact an upper surface (i.e., a recording surface) and a back surface of recording medium P, respectively. The recording medium P on which an image has been recorded at the recording portion7is ejected onto a medium catch portion10with its recording surface facing upward. The medium catch portion10is formed on the upper side of the medium supply cassette3A, so that an outlet communicated with the medium catch portion10is open in the front face of the mainbody housing2and at an upper portion of the first front opening20a, as shown inFIG. 4.

There will be described a structure of a recording medium feeder. As described above, two medium supply cassettes3A,3B are disposed in vertical relation to each other in the present apparatus1, and a first feeder6and a second feeder65that will be described later are provided for the respective medium supply cassettes3A,3B.

As shown inFIG. 4, the upper, the first medium supply cassette3A is accommodated in the first lower casing20to be capable of advancing and retracting therein. The first medium supply cassette3A can accommodate a stack of recording media P which may be cut paper sheets of various sizes such as A4, letter size, legal size, and postcard size. On the other hand, the lower, the second medium supply cassette3B is accommodated in the second lower casing21to be capable of advancing and retracting therein. The second medium supply cassette3B can accommodate a stack of recording media P similar to that the first medium supply cassette3A can accommodate, but a vertical dimension of the second medium supply cassette3B is larger than that of the second medium supply cassette3B so that the maximum volume of the recording media P the second medium supply cassette3B can accommodate is larger than that of the first medium supply cassette3A.

In the second lower casing21for accommodating the second medium supply cassette3B, there are provided a plurality of reinforcing bars63a,63b,63cabove the second medium supply cassette3B to extend across the second medium supply cassette3B, in a direction perpendicular to the feeding direction parallel to an auxiliary scanning direction of the image scanner and the X-axis direction, as shown inFIG. 7. On the under side of the rearmost one of the reinforcing bars63a, there are integrally formed a plurality of ribs51each extending along the feeding direction to serve a dual function as a guide and a reinforcing member, as shown inFIG. 7. The second lower casing21is box-shaped and open on its upper side, and connectable to the under side of the first lower casing20with screws or others (not shown).

The upper, first medium supply cassette3A has an accommodating portion (main cassette portion)31which can accommodate a stack of recording media P with shorter sides of the stack parallel to the main scanning direction i.e., the Y-axis direction. At a front end portion of the first medium supply cassette3A on the side of the front opening20a, there is attached an auxiliary support30which is slidable outward in the X-axis direction so as to support a rear end portion of a relatively long recording medium P such as that of legal size. When a recording medium P which can be entirely accommodated in the first medium supply cassette3A and does not project to the outside of the first lower casing20from the first front opening20a, e.g., a recording medium of A4 size, the auxiliary support30is retracted and accommodated in the first medium supply cassette3A, so as not to interfere with feeding of the recording medium, as shown inFIG. 2.

The second medium supply cassette3B also has an extensible cassette portion33on the side of the second front opening21ain the front face of the second lower casing21. That is, the extensible cassette portion33constitutes a rear half, in a direction in which a recording medium is fed from the second medium supply cassette3B, of a mainbody32of the cassette3B, as shown inFIGS. 4 and 7. The extensible cassette portion33comprises: a front wall50capable of closing the second front opening21aformed in the front face of the second lower casing21; a left-hand support plate and a right-hand support plate each extending horizontally from a lower end of the front wall50so that a rear end portion of a recording medium P is placed on the left- and right-hand support plates; a central support plate; a plate-like operating part52standing to opposed to an inner surface of the front wall50; and a flexible support plate53extending from a base portion of the operating part52to the downstream side in the feeding direction. When the extensible cassette portion33is held in a position near the rear half of the mainbody32of the second medium supply cassette3B, a recording medium P of A4 size can be accommodated in the second medium supply cassette3B. On the other hand, when the extensible cassette portion33is pulled out leftward as seen inFIG. 4to increase the entire length of the second medium supply cassette3B, a recording medium P of legal size which is longer than that of A4 size can be set on the medium supply cassette3B.

At the rear sides (which is the right-hand side inFIG. 4) of the first and second medium supply cassettes3A,3B, a first inclined separator plate8and a second inclined separator plate39are disposed, respectively. The first and second inclined separator plates8,39protrude at a central portion in a width direction of recording medium P, i.e., the Y-axis direction, so that the separator plates8,39are curved rearward in a direction toward extreme lateral ends thereof. That is, the separator plates8,39are curved to be convex frontward in plan view. At the central portion, in the width direction of the recording medium P, of each of the separator plates8,39, there is respectively disposed a first elastic separating pad8aand a second elastic separating pad39athat are like a sawblade, so as to promote separation of each recording medium P by contacting a leading edge of the recording medium P, as shown inFIGS. 4,6and7. The members8,39cooperate with the first feeder6and the second feeder65, respectively, to ensure separation and feeding of each recording medium P.

According to this arrangement where the inclined separator plates8,39are provided at the downstream sides of the medium supply cassettes3A,3B, and the guide34is positioned adjacent to the mainbody housing2as well as the inclined separator plates8,39, a recording medium caught in either of the U-shaped pathways respectively extending from the inclined separator plates8,39to the recording portion7can be eliminated only by removing the guide34.

The first feeder6which separates and feeds one by one the recording media P stacked in the medium supply cassette3A, is attached to the main frame16of the mainbody housing2, as shown inFIGS. 4 and 5. The first feeder6has a first arm body6aone end of which is pivotably supported by the main frame16. To the other end of the first arm body6a, which is a free end, there is rotatably attached a first feeder roller6bfor feeding the recording medium P.

In a bottom plate16aof the main frame16, there is formed an opening16b. A pair of supporting plates (not shown) are formed on respective lateral sides of the opening16bby cutting the bottom plate16aand raising the two cut parts. A driving shaft6cis inserted through the end of the first arm body6aand supported by the supporting plates, so that the driving shaft6cis rotatable. The first arm body6ais rotatable around the driving shaft6cso that the first arm body6ais accommodated with the first feeder roller6bin the opening16b. The first arm body6aincorporates a gear transmission6dwhich transmits rotation of the driving shaft6cto the first feeder roller6b, as shown inFIG. 6.

The second feeder65which separates and feeds one by one the recording media P stacked in the second medium supply cassette3B is disposed over the medium supply cassette3B, as shown inFIG. 4. That is, between the first lower casing20and the second lower casing21, an intermediate plate40(shown inFIG. 4) substantially rectangular in plan view extends in a direction perpendicular to the feeding direction. The intermediate plate40has a pair of supporting parts formed at a substantially central portion thereof by cutting two places of the intermediate plate40and bending the cut parts downward so that the two supporting parts stands parallel to each other. Each of the supporting parts has a shaft hole formed therethrough, and a driving shaft43of synthetic resin is rotatably supported by being inserted through the shaft holes. Between the supporting parts, the driving shaft43is inserted through a longitudinal end of a second arm body66which is substantially rectangular in plan view. The second arm body66and the driving shaft43are supported rotatably with respect to the shaft holes of the supporting parts. The driving shaft43is rotatably supported also by a support member formed by cutting a part in the intermediate plate40in a longitudinal end portion thereof and bending the cut part downward.

A second feeder roller65bis rotatably attached to the other longitudinal end, which is a free end, of the second arm body66to feed recording medium P. The second arm body66incorporates a gear transmission (not shown) which transmits rotation of the driving shaft43to the second feeder roller65b.When the driving shaft43is rotated by a drive motor (not shown) via the gear transmission in the second arm body66, the second feeder roller65brotates in a predetermined direction.

There is provided a switcher67for selectively transmitting a driving force of a drive motor to one of: a gear transmission for the second feeder65for the second medium supply cassette3B; a gear transmission for the first feeder6for the first medium supply cassette3A; and a power transmission gear for a maintenance portion (not shown). The switcher67comprises three gears68a,68b,68c, and a drive gear69, as shown inFIG. 7, and the drive gear69selectively meshes one of the three gears68a,68b,68cin accordance with an amount of displacement of the drive gear69, to the right of the carriage5as seen inFIG. 4.

A radially outermost portion of each of the first and second feeder rollers6b,65bis made of synthetic rubber (e.g., elastomer and EPDM), for instance, and knurls are formed in a direction perpendicular to the feeding direction on an outer circumferential surface of each of the first and second feeder rollers6b,65b. The first arm body6aand the second arm body66are respectively biased by biasing means such as torsion spring so that the free ends of the first and second arm bodies6a,66are biased onto the stack of recording media P.

Each of the first and second feeders6,65that has the arm body6a,66pivotable around the shaft and provided with the drivable feeder roller at its free end, reliably feeds each recording medium toward the guide.

There will be now described guiding means for feeding a recording medium P from each of the first medium supply cassette3A and the second medium supply cassette3B to the recording portion7, while reversing the recording medium P.

As shown inFIG. 2, a recording medium P supplied from the first medium supply cassette3A is fed to the recording portion7disposed above the first medium supply cassette3A, along a first pathway structure35defining a pathway U-turning sideways (feed pathway) for feeding a recording medium upward while reversing the medium. On the other hand, a recording medium P supplied from the second medium supply cassette3B is fed along a second pathway structure36defining a pathway U-turning sideways (feed pathway). The first pathway structure35and the second pathway structure36are connected to form a guide34as shown inFIGS. 8-11. The guide34is removably attached in a space37formed in a rear side portion of the apparatus1. A third pathway structure38for assisting in feeding and reversing of the recording medium P along the first pathway structure35is fixed to the main frame16positioned internally, or in front, of the first pathway structure35, namely, on a side of the first pathway structure35which is near the recording portion7, as shown inFIG. 5.

The space37is formed such that a rear side panel of the second lower casing21has a first cutout37aas shown inFIG. 7, and a rear side panel of the first lower casing20has a second cutout37b, and the first and second cutouts37b,37aare connected in a vertical direction, as shown inFIG. 2. A first engaging member44constituting a first engager is attached to an end surface9bof the upper casing9which faces downward to the space37. Although in the present embodiment the space37is formed to open in the rear side panels of the first and second lower cases20,21, it may be adapted such that the space37is formed across the mainbody housing2and the upper casing9.

The position to attach the engaging member44corresponds to a position where an engaging portion45constituting a second engager is formed in the guide34, as will be described later. However, it is preferable that the engaging member44is attached substantially at a center of the end surface9bin the width direction of the recording medium P, i.e., the Y-axis direction. The engaging member44is a block member of elastic material, e.g., sponge and microcell urethane foam of silicone rubber, EPDM, and butyl rubber. The engaging member44is bonded with an adhesive to the end surface9bof the upper casing9which faces downward.

A downward protrusion64is integrally formed in the end surface9bof the upper casing9which faces downward. The downward protrusion64is positioned externally of the engaging member44. An internal surface of the downward protrusion64is constituted by a guide surface64awhich is inclined downward in a rearward direction, as shown inFIG. 12. By this arrangement, the engaging portion45of the guide34as attached in the space37is guided to the inside of the mainbody housing2, and thus the guide34is prevented from disengaging or running off outward from the apparatus1. An end face of the engaging portion45is inclined to be substantially parallel to the inclined guide surface64aof the downward protrusion64of the upper casing9, as shown inFIG. 12. However, to have the end face of the engaging portion45inclined in this way is not essential.

As shown inFIG. 11, the second pathway structure36is disposed on the external or rear side of the first pathway structure35, and accordingly a curvature radius of the U-turn pathway defined immediately inside the second pathway structure36is larger than that of the U-turn pathway defined inside the first pathway structure35. A plurality of guide ribs46are integrally formed on a rear side of the first pathway structure35to protrude in a circular or arcuate shape, so as to be opposed to an internal surface of the second pathway structure36. The first and second pathway structures35,36are connected to each other such that an end portion of the first pathway structure35on the downstream side in the feeding direction meets the second pathway structure36with a clearance therebetween at a place near an end of the structure36on the downstream side in the feeding direction. Thus, the U-turn pathway defined inside the first pathway structure35merges with the U-turn pathway defined immediately inside the second pathway structure36at the place near the end of the structure36, and the merged pathway extends to the recording portion7.

The first pathway structure35and the second pathway structure36have a plurality of freely rotatable rollers around the place where the two U-turn pathways defined by the first and second pathway structures35,36merge, so as to assist in feeding of recording medium P. More specifically, a plurality of pairs of rollers are disposed at suitable intervals along the feeding direction of recording medium P at a substantially central portion in the width direction of recording medium P, with each pair of rollers adjacent to each other in the width direction of recording medium P, as shown inFIGS. 8,9and11. The plurality of pairs of rollers comprise a first pair47aof rollers and a second pair47bof rollers that are disposed on the first pathway structure35, and a third pair47cof rollers disposed on the second pathway structure36. That is, at a central portion of the first pathway structure35in a lateral direction of the apparatus1, an accommodating recess48for accommodating the first pair47aof rollers and the second pair47bof rollers is formed. In front of the accommodating recess48, a cover49providing a guide surface is detachably attached. The cover49has a window opening49athrough which the first and second pairs47a,47bof rollers are exposed to the pathway along which a recording medium P passes, as shown inFIG. 9.

On a downstream portion, in the feeding direction, of an internal surface of the first pathway structure35, there are integrally formed a plurality of guide ribs54, each arcuate as seen from a lateral side, on each of laterally opposite sides of the cover49. An upstream portion of the first pathway structure35is constituted by a plate portion35athat is circular or arcuate continuously from the guide ribs46. On an internal surface of the arcuate plate portion35a, a plurality of inner reinforcing ribs55are formed, as shown inFIGS. 9 and 11.

On an external surface of the second pathway structure36, a plurality of outer reinforcing ribs56extend. Each of some, namely, a pair in the present specific example, of the outer reinforcing ribs56that are located at a central portion in the lateral direction that is perpendicular to the feeding direction, has an integrally formed extending portion56aconstituting the engaging portion45and protruding farther than the rest part of the outer reinforcing rib56, as shown inFIGS. 8 and 11. These extending portions56aare substantially horizontal. The above arrangement where a first engager in the form of the downward protrusion is on the upper body portion, and a second engager in the form of the extending portion56ais formed on the external surface of the guide34is advantageous in that the first engager does not tend to interfere with or touch the other members than the second engager upon closing of the upper body portion to engage the first engager with the second engager.

A lug57L-shaped in cross section is integrally formed on a rear side of each extending portion56a, as shown inFIGS. 8 and 11, so that the user holds the lug57as a finger grip when handling the guide34(the second pathway structure36). Thus, handling of the guide34is facilitated by the lug57.

An retaining member58, that is generally U-shaped as seen from a lateral side and having a hole58a, is integrally formed at each of lateral ends of the second pathway structure36, while an engaging protrusion59is integrally formed at each of lateral ends of the first pathway structure35, as shown inFIGS. 8-10. When the first pathway structure35and the second pathway structure36are assembled, the second pathway structure36is put on an external surface of the first pathway structure35, and the engaging protrusion59are fitted in the holes58aof the retaining members58at the lateral ends of the second pathway structure36so that the first and second pathway structures35,36are fixed to each other.

A protruding portion60is integrally formed at each of the lateral ends of the second pathway structure36, to protrude outward. A tab61is integrally formed inside each of the protruding portions60, to protrude downward. InFIGS. 9 and 10, one of the two tabs61is shown. On each of opposite lateral sides of the first cutout37aformed in the second lower casing21, there is a horizontal support surface62, and the left and right protruding portions60of the second pathway structure36are placed on the horizontal support surfaces62when the guide34is set in the space37open in a rear face of the apparatus1. Thus, the vertical position of the guide34in the downward direction is determined. Each of the horizontal support surfaces62has a recess (not shown) in which the tab61is loosely fitted. This engagement between the recess and the tab61prevents displacement or rattling of the guide34in the lateral direction as well as the front-rear direction, to some extent. That is, the guide34is positioned mainly by the fitting of a pair of bifurcating portions36bof the guide on a shaft, as fully described later, but the fitting of the tabs61in the recesses also serves to position the guide to a degree to ensure that the downward protrusion64can properly engage the extending portions56a, namely, the downward protrusion64is located on the external or rear side of the extending portions56a.

Two horn-like arms36aprotrude frontward from respective lateral ends of an upper surface of the second pathway structure. Each of the arms36ahas a bifurcating portion36b,which is fitted on a shaft of an upper one of the pair of registering rollers22. Thus, the guide34is positioned in the space37with respect to feeding of a recording medium, with the left and right protruding portions60resting on the horizontal support surfaces62, and the bifurcating portions36bof the arms36abeing fitted on the shaft of the upper registering roller22. Displacement of the guide34in a width direction of the recording medium is restricted by contact of the external surface of each of the two arms36awith a raised portion in an internal surface of the first lower casing20. It is noted that in the invention the term “restrict” is used to mean that the guide is allowed to be displaced in a small amount and thus rattling thereof is allowed to some extent, while the term “inhibit” is used to mean that the guide is allowed to neither rattle nor displace.

As the bifurcating portions36bwear out by rotation of the upper registering roller22, the guide34becomes to tend to come off. However, the vertical position of the guide34with respect to the upward direction is defined by contact of the guide34with a lower end surface of the slide guiding member17shown inFIG. 5. Two ribs51are disposed on an upper external surface of the second pathway structure36so that the two ribs are brought into contact with the lower end surface of the slide guiding member17. However, in place of the ribs51, at least one protrusion may be disposed on the lower end surface of the slide guiding member17so that the at least one protrusion is brought into contact with the upper external surface of the second pathway structure36.

When assembling the guide34to the image recording apparatus1as described above, the upper casing9is widely opened with respect to the mainbody housing2, as shown inFIG. 3. Then, a laterally longitudinal lower end plate36cof the second pathway structure36of the guide34is placed on a surface of the second lower casing21which faces upward and defines a bottom of the first cutout37a, with the bifurcating portions36bof the arms36afitted on the shaft of the upper registering roller22. The protruding portions60at the lateral ends of the second pathway structure36rest on the horizontal support surfaces62, with the tabs61fitted in the pits formed in the horizontal support surfaces62. Then, the upper casing9is turned downward or closed, as shown inFIG. 2, such that the end surface9bof the upper casing9facing downward and an upper end surface of the guide34become parallel to each other, with a lower surface of the elastic engaging member44attached to the upper casing9is pressed onto an upper end surface of each engaging portion45, i.e., the extending portion56a, which takes the form of a plate-like rib, so that the engaging portion45(56a) bites into the elastic member. In this way, the guide34is set in the space37in the rear portion of the mainbody housing2and the upper casing9to close the space37against the outside of the apparatus, and does not come off even when vibration or impact is imposed on the apparatus.

As shown inFIG. 4, a recording medium P fed out from the first medium supply cassette3A is transferred to the recording portion7disposed above the first medium supply cassette3A, along the upper sideways U-turn pathway defined inside the first pathway structure35, and a recording medium P fed out from the second medium supply cassette3B is transferred to the recording portion7along the upper sideways U-turn pathway defined immediately inside the second pathway structure36. As being thus fed along a curved surface of the first pathway structure35or the second pathway structure36, the recording medium P, which has a certain degree of rigidity and accordingly a resistance to being bent, presses the guide34. However, according to the present embodiment, the guide34is prevented from coming off of the mainbody housing2and the upper casing9, outward or rightward as seen inFIG. 5. Hence, the guide34is prevented from falling off due to the looseness in fitting thereof in the space37, an impact imposed on the apparatus1, or some other reasons, even while the image recording apparatus1is transported.

The downward protrusion64having the guide surface64ainclined to the external side in the downward direction is formed on a lower end of the upper casing9. Therefore, when the upper casing9is closed or turned downward, the inclined guide surface64aguides the guide34into the mainbody housing2, thereby positioning the guide34. Where the guide34is in a tilted position, the inclined guide surface64ais brought into abutting contact with the engaging portion45(56a), and accordingly the upper casing9can not be completely closed, thereby the user can recognize that the guide34is not in position.

When a recording medium P is caught between the second pathway structure36and the first pathway structure35, or the second pathway structure36and the third pathway structure38, or between the pair of registering rollers22, while the recording medium P is fed toward the recording portion7, the recording medium P can be easily removed by widely opening the upper casing9upward, as shown inFIG. 3, and then detaching the guide34. That is, the guide34is easily detached by releasing the engagement between the engaging member44and the downward protrusion64by merely opening the upper casing9.

There will be now described an image recording apparatus100according to a second embodiment of the invention, by referring toFIG. 13. In the following description with respect to the second embodiment, parts or elements corresponding to those of the first embodiment will be denoted by the same reference numerals and description thereof is not provided.

As shown inFIG. 13, in this embodiment, an elastic member144constituting a second engager is bonded to a surface of an extending portion56aof a guide36, and not attached to an upper casing9. On a lower end surface of the upper casing9, there is formed a downward protrusion64as a first engager. The downward protrusion64has an inclined surface64asimilar to that in the first embodiment that is to engage extending portions56aof ribs56integrally formed on a second pathway structure36when the upper casing9is closed or turned downward. Unlike the first embodiment, there is no clearance between the inclined surface64aof the downward protrusion64and the extending portion56awhen the upper casing9is closed, but the inclined surface64ais brought into contact with the elastic member144. By this contact, a displacement of a guide34in the vertical direction as well as outward can be prevented.

There will be now described an image recording apparatus according to a third embodiment of the invention, by referring toFIG. 14. The third embodiment is similar to the first embodiment except some parts. The elements or parts corresponding to those of the first embodiment will be denoted by the same reference numerals and description thereof is not provided.

In the third embodiment shown inFIG. 14, at a place where an elastic engaging member44constituting a first engager is attached to an upper casing9, there is not formed a downward protrusion64with an inclined guide surface64a. In the present embodiment, too, a guide34disposed in a space37can be set in position when the upper casing9is closed with respect to a mainbody housing2, and rattling of the guide34is prevented.

In each of the first through third embodiments, the first engager and the second engager are normally in pressing contact with each other, but this pressing contact is not essential to attain the object of the invention. That is, the first and second engagers may not be in contact with each other while the guide34is neither rattling nor displaced.

It is not essential to make on purpose at least one of the first and second engagers easily deformable.

Further, in each of the first and third embodiments, the engaging member44may be formed integrally with the upper casing9, using the same synthetic resin as that of the upper casing9. Similarly, in the second embodiment, the elastic member144may be formed integrally with the extending portion56ain the guide34, using the same synthetic resin as that of the pathway structures35,36of the guide34. When the engaging member44is formed integrally with the upper casing9, or when the elastic member144is formed integrally with the extending portion56aon the guide34, as described above, the number of components as well as the manufacturing cost of the apparatus can be reduced.

There will be described an image recording apparatus according to a fourth embodiment of the invention, by referring toFIGS. 15-17. The parts or elements corresponding to those of any of the above-described embodiments will be denoted by the same reference numerals and description thereof is not provided.

In the fourth embodiment, each of a plurality of second engagers is constituted by a butterfly member70as shown inFIG. 15. The butterfly member70has a pair of protruding portions70athat are contiguous and symmetric with respect to a line70bwhich corresponds to an upper end as described later, and a pair of substantially triangular proximal portions70ceach of which is continuous from one of the protruding portions70a. The butterfly members70are die-cut from a synthetic resin film of PET or other materials. On a side of each of the proximal portions70c, which is to be an inner side, a double-faced adhesive tape71as indicated by hatching inFIG. 15is adhered.

A plurality of plate-like reinforcing ribs56are formed on an external surface of a second pathway structure36of a guide34. When each of the butterfly members70is assembled, a release tape (not shown) on each double-faced adhesive tape71is peeled off, and then the proximal portions70cof the butterfly member70are attached to opposite sides of one of some, namely a pair in the present embodiment, of the reinforcing ribs56that are located at a central portion in a direction perpendicular to a direction of feeding recording medium, i.e., a lateral direction of the guide34, such that the butterfly member70is folded in half at the line70b, which forms the upper end of the butterfly member70as assembled. In this way, the butterfly member70is attached to protrude upward from an upper surface of the outer reinforcing rib56, as shown inFIG. 16. Each protruding portion70ahas a first guide edge72aand a second guide edge72bthat are inclined in opposite directions. The first guide edge72ais formed between the upper end70band a rear end of the protruding portion70a, and the second guide edge72bis formed between the upper end70band a front end of the protruding portion70a.

The guide34on which the butterfly member70is attached is set in the space37ain the mainbody housing2, and then an upper casing9is closed, with the first and second guide edges72a,72bof the protruding portions70a, that now takes the form of a relatively thin protrusion constituting a second engager, being guided on and along an internal surface9cat a lower end portion of the upper casing9and a surface of the mainbody housing2that are accessible from the lower side of the upper casing9. In this way, the protruding portions70aof the thin protrusion is guided in a gap73formed between the upper casing9and the mainbody housing2so as not to easily come off, and thus constitutes a second engager. This prevents the guide34from easily coming off. In the present embodiment, where the user removes the guide34by force while the upper casing9is closed with respect to the mainbody housing2, the protruding portions70aor the thin protrusion formed of a film material to be elastic deforms to allow coming off of the guide34upon a force beyond a resisting force of the protruding portions70ais imposed. In contrast, where each of the thin protrusion is formed integrally with the outer reinforcing rib56of the guide34by using the same material as the reinforcing rib56, the guide34may break at the outer reinforcing rib or ribs56when the guide34is removed by force. The guide member34according to the present embodiment is free from this problem. Further, since the protruding portions70aor the thin protrusion is formed of an elastic film material, even when an end surface9bof the upper casing9is brought into abutting contact with the thin protrusion upon closing of the upper casing9with the guide34set in the space37in the mainbody housing2improperly, that is, the posture and/or location of the guide34being improper, the end surface9bmerely presses and deforms the thin protrusion70aand does not cause damage to the guide34. Still further, even when the guide34receives a resisting force from a recording medium P passing and reversed along an internal surface of the guide34by being bent in a U-like shape, and is thus pressed to the external side of the mainbody housing2, the thin protrusion70amade of a film material does not tend to deform in a direction parallel to a surface thereof, thereby preventing the guide34from coming off of the image recording apparatus.

In each of the first through third embodiments where engagement between the guide and the upper casing9is established via an elastic member, i.e., the elastic engaging member44or the elastic member144, the engagement is maintained while deformation of the elastic member is allowed. Thus, it is easily enabled to hold the upper casing9closed with respect to the mainbody housing2without rattling of the guide34.

In each of the first and third embodiments, since the extending portion56ais formed in the form of a rib, when the elastic member44engages the extending portion56a, an upper end portion of the extending portion56abites into the elastic member44, thereby providing a relatively large force against the rattling and displacement of the guide. Thus, the guide34is further reliably prevented from coming off.

In each of the above-described embodiments, since the lug57to be held by the user is integrally formed in the extending portion56aof the reinforcing rib56, the guide34is simplified in structure, thereby reducing the manufacturing cost of the apparatus. Further, since the second engager is provided by or on the extending portion56aof the rib56, the effect of simplifying the structure of the guide34and reducing the manufacturing cost is enhanced.

In each of the above-described embodiments, the engagement between the upper casing9and the guide34is released by merely turning the upper casing9upward and away from the mainbody housing2. Hence, the guide34is extremely easily removable. Accordingly, in the case of a jam, the recording medium can be easily eliminated.

In the above-described embodiments, the shaft9aaround which the upper casing9is pivotally supported is disposed to be parallel to the direction of feeding of recording medium P. However, the same operation and effects as the above-described embodiments can be obtained even when the shaft9aof the upper casing9is disposed to be perpendicular to the feeding direction.

In the invention, the first and second engagers may or may not be in direct contact with each other. However, provision of an elastic member between the upper casing and the guide prevents rattling therebetween, and also rattling of the second pathway structure36.

In the invention, the “lower body portion” is not limited to a mainbody housing made of synthetic resin as that in the embodiments, but may be a metallic mainbody frame enclosed in such a mainbody housing, and the “upper body portion” is not limited to an upper casing made of synthetic resin as that in the embodiments, but may be a metallic upper frame enclosed in the upper casing.