Image forming apparatus

An image forming apparatus has a tray, which is able to be drawn out of the apparatus and on which a plurality of cartridges of different sizes can be mounted. A cartridge, being the largest in size among a plurality of process cartridges, is detachably arranged at a location at which it is first exposed to outside when a cartridge tray is drawn out. A developer storage portion of the largest cartridge has the largest capacity and stores a developer of a black color.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image forming apparatus having a supporting member on which a plurality of cartridges are adapted to be mounted in a detachable manner.

2. Description of the Related Art

In an image forming apparatus using an electrophotographic image forming process, there has been adopted a system in which at least one of an electrophotographic photosensitive member, a process unit acting on the electrophotographic photosensitive member, and a developer storage portion with a developer stored therein is formed into a cartridge and is detachably attached to an image forming apparatus main body. According to such a cartridge system, a user is able to perform the maintenance of the apparatus without resort to a serviceman. As a result, convenience and efficiency in operation of the apparatus can be improved to a remarkable extent. Therefore, such a cartridge system has been used in a lot of electrophotographic image forming apparatuses.

For such a detachable construction of a cartridge, there is known a system in which a cartridge being carried on a tray is drawn out for detachment and attachment thereof (see Japanese patent application laid-open No. 2006-184901 and U.S. Pat. No. 2,005,147,432).

However, in an image forming apparatus that has a drawer or tray to which a plurality of cartridges can be attached, in case where only a specific cartridge is made larger in size because of a large amount of consumption of a specific developer contained in the specific cartridge, etc., there will be a possibility that the image forming apparatus might have to be increased in size, or a waste of space might occur.

SUMMARY OF THE INVENTION

Accordingly, the object of the present invention is to provide an image forming apparatus of the type that has a supporting member, on which a plurality of cartridges of different sizes can be mounted and which is able to be drawn out, and that is able to prevent the waste of space or reduce the amount of wasted space.

Another object of the present invention is to provide an image forming apparatus which is capable of forming an image on a recording medium, and which includes: a main body frame; and a supporting member that is movable between an inner position in which the supporting member is located at an inner side of the main body frame and an outer position in which the supporting member is located at an outer side of the main body frame, and that has a mounting portion on which a first cartridge and a second cartridge are detachably mounted. The first cartridge is mounted on the most downstream side of the mounting portion in a drawing direction in which the supporting member is drawn out from the inner position to the outer position, and the second cartridge is mounted on an upstream side of the first cartridge in the drawing direction, and in a state where the first cartridge and the second cartridge are mounted on the mounting portion, and the first cartridge has a protruded portion that protrudes in a direction orthogonal to the drawing direction more than the second cartridge does.

Another object of the invention is to provide an image forming apparatus which is capable of forming an image on a recording medium, and which includes: a main body frame; and a tray that is movable between an inner position in which the supporting member is located at an inner side of the main body frame and an outer position in which the supporting member is located at an outer side of the main body frame, and that has a mounting portion on which a first cartridge and a second cartridge are detachably mounted. The first cartridge is mounted on the most downstream side of the mounting portion in a drawing direction in which the supporting member is drawn out from the inner position to the outer position, and the second cartridge is mounted on an upstream side of the first cartridge in the drawing direction, and the first cartridge is larger than the second cartridge.

The above and other objects, features and advantages of the present invention will become more readily apparent to those skilled in the art from the following detailed description of a preferred embodiment of the present invention taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, a preferred embodiment of the present invention will be described in detail while referring to the accompanying drawings. In all the figures of the following embodiment, the same symbols are attached to the same or corresponding parts or elements.

(Overall Construction of an Electrophotographic Image Forming Apparatus)

First of all, reference will be made to an electrophotographic image forming apparatus which is able to form an image on a recording medium. This electrophotographic image forming apparatus is of an in-line type having a plurality of process cartridges50(50y,50m,50c,50k) arranged in a line or row. InFIGS. 1 and 2, there is shown the electrophotographic image forming apparatus (hereinafter referred to as an apparatus main body)100to which the process cartridges50(hereinafter referred to simply as “cartridges”) are attached in a detachable manner. Here, the cartridge50kacting as a first cartridge has a first developer storage portion in which a toner T of a black color (kT) acting as a first developer is stored. In addition, the other cartridges50y,50m,50cacting as second cartridges have second developer storage portions in which toners T of a yellow color (yT), a magenta color (mT) and a cyan color (cT) acting as second developers are stored, respectively.

As shown inFIG. 1, in the apparatus main body100acting as a main body frame, laser beams11irradiate, based on an image signal, the surfaces of electrophotographic photosensitive drums30(hereinafter referred to simply as photosensitive drums), respectively, which act as image bearing members, by means of a laser scanner10acting as an exposure unit. As a result, electrostatic latent images corresponding to the individual colors are formed on the individual photosensitive drums30(30y,30m,30c,30k), respectively. These electrostatic latent images are developed by individual developing rollers42, respectively, to form developer images in the form of toner images on the surfaces of the photosensitive drums30, respectively. By impressing voltages on transfer rollers18y,18m,18c,18k, the toner images of the individual colors formed on the individual photosensitive drums30are sequentially transferred onto a transfer surface of a transfer unit (an intermediate transfer member) in the form of an intermediate transfer belt19along a drawing direction in which a tray13as a supporting member is drawn out. As a result, the toner images of the individual colors are superposed or overlapped with one another on the intermediate transfer belt19.

Thereafter, the toner images formed on the intermediate transfer belt19are transferred by transfer rollers3onto a recording medium P that is carried by a feed unit in the form of a feed roller1at a most upstream side of the intermediate transfer belt19in the drawing direction of the tray13(in the direction of arrow D2inFIG. 6). Thereafter, the recording medium P is conveyed to a fixing unit in the form of a fixing device6that is composed of a driving roller and a fixing roller with a heater incorporated therein. Here, note that the fixing device6is arranged at a location upstream of the tray13in the drawing direction thereof. Then, the fixing device6heats and applies pressure on the recording medium P on which the toner images have been transferred, whereby the toner images are fixed to the recording medium P. After that, the recording medium P with the toner images fixed thereon is discharged to a discharge unit in the form of a discharge tray9by means of a pair of discharge rollers7.

(Overall Construction of the Process Cartridges)

Next, reference will be made to the cartridges50(50y,50m,50c,50k) according to this embodiment. The cartridges according to this embodiment are shown inFIG. 3andFIG. 4. In addition, the states of the cartridges50when they are attached and detached to the apparatus main body100are shown inFIG. 5andFIG. 6, respectively. In this embodiment, a process cartridge will be described as one form of the cartridges. Here, the process cartridge is a cartridge in which a charging unit, a developing unit, an electrophotographic photosensitive member, and so on are integrally formed into a single unit, and which is constructed in such a manner that it can be attached and detached to the image forming apparatus main body.

As shown inFIG. 3, toners yT, mT, cT, kT of different colors are stored in the cartridges50y,50m,50c,50k, respectively. In addition, the cartridge50kis of the same construction as the other cartridges50y,50m,50cexcept for the kind of its toner to be stored therein and the size of its toner storage portion (developer storage portion). Accordingly, in the following description, the construction of the interior of that cartridge will be described by using the other cartridges50y,50m,50c. Here, note that those of the black cartridge50kwhich are different from the other cartridges will be described later.

The cartridges50are each provided with a photosensitive drum30and a developer image forming unit in the form of a process unit acting on a corresponding photosensitive drum30. Here, note that the process unit indicates a charging unit32, a developing roller42, a toner storage portion49, a cleaning unit33, a waste toner storage portion35and so on.

The charging units32serve to charge the corresponding photosensitive drums30, respectively. The developing rollers42serve to develop the latent images formed on the corresponding photosensitive drums30, respectively. The toner storage portions49acting as the developer storage portions receive toners T for developing the latent images, respectively. The cleaning units33serve as toner removing units for removing and cleaning the residual toners that remain on the surfaces of the corresponding photosensitive drums30, respectively. The waste toner storage portions35serve to receive and store the corresponding residual toners, respectively.

Each of the cartridges50has a first unit31and a second unit41.

(Construction of the First Unit)

Now, the first unit31will be described. The first unit31has a photosensitive drum30, a charging unit32, a cleaning unit33, a drum frame34, and a waste toner storage portion35, as shown inFIG. 3.

As shown inFIG. 4, the photosensitive drum30has one longitudinal end thereof rotatably supported by a cover member36(such an arrangement being similar in the case of a developing roller42). On the other hand, the photosensitive drum30has the other longitudinal end thereof rotatably supported by a cover member37. These cover members36,37are fixedly secured to drum frame34at the opposite longitudinal ends of the drum frame34.

In addition, a coupling member30afor transmitting a driving force to the photosensitive drum30is arranged at one longitudinal end of the photosensitive drum30. This coupling member30ais placed into engagement with a first main body coupling member105when the cartridge50is attached to the apparatus main body100, as shown in FIG.6. A driving force is transmitted from a drive motor (not shown) mounted on the apparatus main body100to the coupling member30a, so that the photosensitive drum30is thereby driven to rotate in the direction of arrow u, as shown inFIG. 1andFIG. 3.

Also, the charging unit32is supported by the drum frame34in such a manner that it can be driven to rotate following the rotation of the photosensitive drum30while being in contact therewith. The cleaning unit33is supported by the drum frame34in such a manner that it is placed into abutment with the circumferential surface of the photosensitive drum30by a predetermined pressure.

(Construction of the Second Unit)

Next, the second unit41will be described. As shown inFIG. 3, the second unit41has a developing roller42, a developing blade43, and a developing frame body48. The developing frame body48has a toner storage portion49that stores a toner supplied to the developing roller42, and a developing blade43that restricts the layer thickness of the toner on the circumferential surface of the developing roller42. In addition, as shown inFIG. 4, in order to drive the developing roller42to rotate, a coupling member67being driven from the apparatus main body100is arranged at one end of the developing roller42. Here, note that the toner storage portion49corresponds to a developer storage portion (i.e., a first developer storage portion in case of the cartridge50k, and a second developer storage portions in case of the other cartridges50y,50m,50c).

(Drawing Out from the Image Forming Apparatus Main Body)

Next, a drawing member in the form of a cartridge tray13(hereinafter referred to simply as a “tray”) will be described.

The tray13is movable in one direction of D1(the direction of pushing) and in the other direction of D2(the direction of drawing) with respect to the apparatus main body100, as shown inFIG. 6. That is, the tray13is arranged in such a manner that it can be drawn out and pushed in. The tray13is movable substantially in a horizontal direction. In addition, the tray13is movable among an image forming position in the apparatus main body100(seeFIGS. 1 and 2), an inner spaced-apart position that is apart from the intermediate transfer belt19in the interior of the apparatus main body100(seeFIG. 5), and a drawn-out position (outer position) in which it is drawn out from an attachment or mounting position thereof to the apparatus main body100(seeFIG. 6). In particular, in this embodiment, the above-mentioned image forming position, the above-mentioned inner spaced-apart position, and intermediate positions between these positions are generally called pushed-in positions (inner position). Here, note that the tray13has a mounting portion13ato which the plurality of cartridges50(50y,50m,50c,50k) can be mounted or attached (seeFIG. 6).

Each of the cartridges50is detachably fitted or attached to the mounting portion13aalong a direction of arrow C with the tray13being located in the drawn-out position, as shown inFIG. 6. In this manner, the tray13serves to support the individual cartridges50.

The individual cartridges50being placed in the mounting portion13aare caused (pushed) to come into the apparatus main body100together with the tray13. At this time, as shown inFIG. 5, the cartridges50are moved in a state where the transfer member in the form of the intermediate transfer belt19arranged thereunder and the photosensitive drums30are kept apart a predetermined distance F from each other. That is, the cartridges50are moved along a direction parallel to the transfer surface of the intermediate transfer belt19. As a result, the tray13is moved up to the inner spaced-apart position (pushed-in position).

Thereafter, when a door12is closed, the cartridges50are positioned in place with respect to the apparatus main body100. That is, the tray13is moved up to the image forming position (pushed-in position). Thus, it is possible to improve user operability in comparison with the case where the cartridges50are individually fitted or attached to the inner side of the apparatus main body100independently or separately from one another.

Now, the operation of the tray13will be described below. In the following description, the explanation and illustration of the cartridges will be omitted for the easy and clear understanding of the operation of the tray13. The operation of the tray13is shown inFIGS. 7,8and9.

The tray13is supported by a tray holding member14in such a manner that it can be drawn out with respect to the tray holding member14. This tray holding member14is operated in association with the motion of the door12, which acts as an opening and closing member. The door12is attached to the apparatus main body100for rotation about an axis of rotation12a. The door12is constructed such that it is rotatable between a closed position in which it closes an opening80, as shown inFIG. 7, and an open position in which it opens the opening80, as shown inFIG. 8.

Next, reference will be made to the case where the cartridges fitted to the apparatus main body100are taken out. First of all, the door12is caused to rotate from the closed position to the open position. In accordance with the rotation of the door12, an engagement portion15formed on the door12is moved to rotate about the axis of rotation12ain a clockwise direction inFIG. 7. As a result, as shown inFIG. 8, the engagement portion15is caused to move an elongated hole14cformed in the tray holding member14from its lower end14c2to its upper end14c1. In accordance with the movement of the engagement portion15, the tray holding member14is forced to move in a direction away from the intermediate transfer belt19(i.e., in the direction of arrow y1inFIG. 8), and, as shown inFIG. 9, in this state, the tray holding member14is moved through the opening80in the direction of arrow D2in this figure, so that it is drawn out to the outside of the apparatus main body100. A perspective view in the state at this time is shown inFIG. 12.

Now, reference will be made to the case where the cartridges50are fitted or attached to the apparatus main body100. As shown inFIG. 9, in a state where the door12is located in the open position, the tray13is caused to move so as to pass the opening80in the direction of arrow D1, whereby it is pushed (moved) into the apparatus main body100. After that, the door12is forced to rotate up to the closed position, as shown inFIG. 7. In accordance with the rotation of the door12, the engagement portion15formed on the door12is moved to rotate about the axis of rotation12ain the counterclockwise direction. As a result, as shown inFIG. 7, the engagement portion15is caused to move in the elongated hole14cformed in the tray holding member14from its upper end14c1to its lower end14c2. In accordance with this movement, the engagement portion15operates to move the tray holding member14in a direction toward the intermediate transfer belt19(i.e., in the direction of arrow y2inFIG. 7). In this manner, the cartridges50are positioned in place with respect to the apparatus main body100.

(Attachment of the Process Cartridges to the Apparatus Main Body)

Next, reference will be made to the operation of attaching the cartridges50(50y,50m,50c,50k) to the apparatus main body100.

As shown inFIG. 6, the cartridges50are fitted or attached to the tray13(more specifically, its mounting portion13a), which has been drawn out to its drawn-out position, along the direction of arrow C. Then, by moving the tray13in the direction of arrow D1, the cartridges50are forced to come into the apparatus main body100through the opening80.

In this embodiment, the cartridges50are forced to move into the apparatus main body100in a direction substantially perpendicular to the axial direction of the photosensitive drums30(the developing rollers42).

Here, as shown inFIG. 1, the black cartridge50kis detachably attached to the most downstream side of the mounting portion13ain the drawing direction of the tray13. Then, the other cartridges50y,50m,50care also detachably attached to the mounting portion13aat locations upstream of the cartridge50k. An upper surface portion48akof the developing frame body48in this cartridge50khas a space or distance to the laser scanner10which is narrower in comparison with those of upper surface portions48ay,48am,48acof the developing frame bodies48in the cartridges50y,50m,50c, respectively. That is, it is constructed such that the distance of the cartridge50kto the laser scanner10in the direction away from the intermediate transfer belt19(i.e., in a direction substantially perpendicular to the drawing direction of the tray13) is the narrowest in comparison with those of the other cartridges50y,50m,50c. The toner storage portion49of the cartridge50kbecomes larger in comparison with each of the toner storage portions49of the other cartridges50y,50m,50c. Accordingly, the first cartridge in the form of the cartridge50kstoring the toner of a black color has a toner capacity larger in comparison with those of the other second cartridges50y,50m,50c(containing toners other than the black toner).

Here, note that as a method of making the capacity for the black toner larger than those for the toners of the other colors, it is possible to adopt another method of enlarging the width of the black toner storage portion in the developing frame body48to the right and left direction (the drawing direction) inFIG. 1. However, according to this embodiment, the distance between the photosensitive drum30kand the photosensitive drum30ccan be decreased as compared with the method of enlarging the width of the black toner storage portion in the drawing direction, thus making it possible to reduce the size or dimensions of the apparatus main body100. In addition, according to this embodiment, a color shift (color registration shift or deviation) between images of plural colors can be decreased as compared with the method of enlarging the width of the black toner storage portion in the drawing direction, thereby making it possible to obtain high image quality. This is because the intervals between the plurality of photoreceptors drums30can be made equal.

Similarly, an upper surface portion34akof the drum frame34in the cartridge50kalso has a space or distance to the laser scanner10which is narrower in comparison with those of upper surface portions34ay,34am,34acof the drum frames34in the cartridges50y,50m,50c, respectively. As a result, it is possible to deal with an increase in the amount of waste toner due to an increase in the capacity of the black toner. That is, in the waste toner storage portion35of the cartridge50k, too, the capacity thereof is intended to be increased in a similar manner as in the capacity increase of the corresponding toner storage portion. In this case, in order to prevent the enlargement of the apparatus main body100while making distances between mutually adjacent photosensitive drums30equal to one another, it is constructed such that the size of the waste toner storage portion35is not increased in the horizontal direction ofFIG. 1. In addition, as a modification of this embodiment, the developing frame body of the cartridge50kand those of the other cartridges50y,50m,50cmay be made different in shape from each other, but the drum frame34of the cartridge50kand those of the other cartridges50y,50m,50cmay be made into the same shape. That is, the height of the upper surface portion34akmay be made identical to the height of the upper surface portions34ay,34am,34ac. With such a modification, it becomes possible to reduce the cost of the drum frames34as a whole, while achieving the above-mentioned advantageous effects except for an advantageous effect of the increased amount of the waste toner.

In this embodiment, as compared with the other cartridges50y,50m,50c, the cartridge50khas a protruded portion50k1protruding in a direction orthogonal to the drawing direction. More specifically, the cartridge50khas the protruded portion50k1that protrudes in a direction orthogonal with respect to both the drawing direction and the axial direction of the developing roller42, as compared with the other cartridges50y,50m,50c. The protruded portion50k1constitutes a part of the toner storage portion49of the cartridge50k. As a result, the service life of the black cartridge50kcan be extended, so the frequency of replacement thereof can be decreased. In addition, with such a construction, the space upstream of the protruded portion50k1in the drawing direction can be effectively made use of, so the space efficiency of the entire image forming apparatus can be improved. Moreover, the protruded portion50k1can be formed to protrude in the axial direction of the developing roller42, but in this embodiment, the protruded portion50k1is constructed such that it protrudes only in the orthogonal direction which is orthogonal with respect to both the drawing direction and the axial direction of the developing roller42. With such a construction, surroundings of the tray13can be made simpler in construction, as compared with the case in which the protruded portion would be formed to protrude in the axial direction of the developing roller42. Further, in this embodiment, it is possible to decrease the distance by which the tray13is drawn out, in comparison with the construction in which the size of the cartridge50kis increased in the drawing direction. Therefore, the usability thereof can be improved according to this embodiment.

In addition, as shown inFIGS. 1 and 2, in this embodiment, the black cartridge50khaving the largest toner capacity and the most weight is attached to the most downstream (outer) side of the mounting portion13aalong the drawing direction. As a consequence, in case where the black cartridge50kis replaced with a new one, the cartridge50kcan be first exposed to the outside upon drawing out the tray13.

Therefore, it becomes unnecessary for drawing out the tray13from the apparatus main body100up to a whole color replacement position in which all the cartridges are exposed, as shown inFIG. 6. That is, the tray13need only be drawn out to a position in which only the cartridge50kcan be replaced with a new one, so it becomes easy to replace the black cartridge50k, which has to be replaced at a relatively high frequency.

In order to make use of gaps between the laser scanner10and the upper surface portions48ay,48am,48acof the cartridges50y,50m,50cso as to prevent a temperature rise in the apparatus main body100(i.e., in the main body frame), an air stream restricting plate60that acts as a restriction unit for restricting an air stream is fixed in the apparatus main body100. Here, note that the air stream restricting plate60, as the restriction unit can be called is a fixed member which is fixedly arranged inside the apparatus main body100(the main body frame). Here, the air stream restricting plate60is constructed such that at least part thereof overlaps with at least part of the protruded portion50k1, as viewed in the drawing direction. This air stream restricting plate60will now be described in detail.FIG. 10shows a cross sectional view along a line J-J inFIG. 1, andFIG. 11shows a cross sectional view along a line K-K inFIG. 1.

First of all, as elements and factors that raise the temperature in the apparatus main body100, there exist the fixing device6, the laser scanner10, the rotations of the developing rollers42and the photosensitive drums30in the cartridges50, and so on. When the temperature in the apparatus main body100reaches a predetermined temperature or above due to the influence of these elements and factors, the toners in the cartridges50adhere thereto. In addition, displacements in the mounting portion of the laser scanner10and cartridge positioning portions in the apparatus main body100can occur due to heat generated therein. Because of such displacements, it will become difficult to form an image on a recording material or medium exactly. Accordingly, a fan70is arranged in the apparatus main body100for preventing a temperature rise therein.

This embodiment is constructed such that the single fan70is arranged among the fixing device6, the laser scanner10and the cartridges50, all of which are temperature raising elements, whereby these components can be cooled in an efficient manner with the use of the least possible number of fans.

This fan70operates to rotate so as to blow air into the apparatus main body100. As a result, as shown inFIG. 12, outside air is taken into the apparatus main body100from a louver100athat is arranged on a right side wall thereof, as viewed in the drawing direction of the tray13.

As shown inFIG. 10, the outside air a, blown into the apparatus main body100by means of the fan70, passes through an air path or passage a1, for cooling of the fixing device6, so that it cools the fixing device6in an air passage a1-1. In addition, the outside air a also passes through an air passage a2that serves to insulate the yellow cartridge50yand the laser scanner10from heat, so that it cools the yellow cartridge50yin an air passage a2-1. Also, a part of branched outside air a3passes through an air passage a4that serves to insulate the magenta cartridge50mand the laser scanner10from heat, so that it cools the magenta cartridge50min an air passage a4-1. Further, outside air a5branches into a pair of air passages a6, a7which serve to cool the cyan cartridge50cand insulate the cyan cartridge50cand the laser scanner10from the heat, so that it is forced to flow into a pair of air passages a6-1, a7-1.

Thereafter, air streams of the outside air thus formed are blown from a right side surface100bof the apparatus main body100toward a left side surface100cthereof, as shown inFIG. 10andFIG. 12, whereby the fixing device6, the cartridges50and the laser scanner10are respectively cooled, and at the same time the cartridges50and the laser scanner10are thermally insulated.

Here, the air stream restricting plate60has a plurality of restriction plate members60bthat are arranged in the gaps, respectively, between the laser scanner10and the upper surface portions48ay,48am,48acof the cartridges50y,50m,50c. In other words, at least a part of the air stream restricting plate60overlaps with at least parts of the cartridges50y,50m,50c, as viewed in a direction orthogonal to the drawing direction. And, as shown inFIG. 10andFIG. 11, the restriction plate members60bare arranged to extend from the right side surface100bof the apparatus main body100toward the left side surface100cthereof. As a result, the outside air a supplied to the interior of the apparatus main body100by means of the fan70can be forced to flow from the right side surface100bof the apparatus main body100toward the left side surface100cthereof.

Cooling can be carried out in an efficient manner by arranging these restriction plate members60bat locations much closer to the upper surface portions48ay,48am,48acof the cartridges50y,50m,50c. That is, the air passages defined by the cartridges50y,50m,50cand the restriction plate members60bare made into more closed spaces, so it is possible to suppress the diffusion of the flow of gas (air streams) flowing from the right side surface100bof the apparatus main body100toward the left surface100cthereof. Further, it is also possible to perform cooling in an efficient manner because air streams are able to flow smoothly without obstruction. Here, note that the air stream restricting plate60has holes60aformed therein so as to permit the laser beams emitted from the laser scanner10to pass therethrough.

In addition, in this embodiment, as stated above, at the time of attaching and detaching a cartridge, the cartridge is moved a distance F in the direction of y1in the apparatus main body100in accordance with the upward movement of the tray13, as shown inFIG. 5. Therefore, it is necessary to make the gaps between the restriction plate members60band the upper surface portions48ay,48am,48acof the developing frame bodies48of the cartridges50y,50m,50cin their image forming state ofFIG. 1equal to or larger than the predetermined distance F shown inFIG. 5.

Moreover, in this embodiment, the fixing device6, which is a heat source having the greatest influence, is arranged at the most upstream side in the drawing direction of the tray13, so that a large distance between the fixing device6and the black cartridge50kcan be ensured. Accordingly, the air stream restricting plate60is not arranged between the black cartridge50kand the laser scanner10.

Although in the foregoing description, one embodiment of the present invention has been specifically described, the present invention is not limited to the above-mentioned embodiment, and the invention can be varied into a variety of forms based on the technical concept of the present invention. For example, numerical values enumerated in the above-mentioned embodiment are merely some examples, so numerical values different from these may be used as required.

For example, in the above-mentioned embodiment, a description has been provided of the case where the air stream restricting plate60is formed separately from the laser scanner10, but similar advantageous effects can be achieved even if they are formed integrally with each other. In addition, in place of the air stream restricting plate60of the above-mentioned embodiment, a portion of the laser scanner10may be arranged as the fixed member (seeFIG. 13). That is, inFIG. 13, there is illustrated a case where a construction is adopted in which the laser scanner10has at least a part of a downwardly protruded portion arranged to overlap with at least a part of the protruded portion50k1, as viewed in the drawing direction.

In this embodiment, the plurality of second cartridges are employed, but only a single second cartridge may instead be used.

In addition, in this embodiment, specific examples of the electrophotographic image forming apparatus include electrophotographic copiers, electrophotographic printers (e.g., laser beam printers, LED printers, etc.), facsimile machines, word processors, and so on.

In addition, in this embodiment, a description has been provided of the case where the cartridges comprise process cartridges, but the present invention can be applied to cartridges that have at least part of an electrophotographic photosensitive member, a process unit, a developer storage portion, etc. That is, the invention can also be applied to cartridges other than the process cartridges of this embodiment. For example, there can be exemplified developer cartridges that have a developer storage portion storing therein a developer, and developing cartridges that have, as a cartridge, the second unit41of this embodiment alone. Moreover, the invention can also be applied to cleaner cartridges that have, as a cartridge, the first unit31of this embodiment alone, or applied to electrifying cartridges that have an electrifying unit, or the like.

This application claims the benefit of Japanese Patent Application No. 2007-210107, filed on Aug. 10, 2007, Japanese Patent Application No. 2008-152101, filed on Jun. 10, 2008, and Japanese Patent Application No. 2008-183893, filed on Jul. 15, 2008, which are hereby incorporated by reference in their entirety.